Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/28/14
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
812 PM PDT SUN APR 27 2014
.UPDATE...WINDS HAVE REMAINED BELOW ADVISORY LEVELS OVER THE KERN
COUNTY MOUNTAINS AND DESERT. THE ADVISORY HAS BEEN CANCELED.
&&
.SYNOPSIS...
LOCALLY GUSTY WINDS WILL CONTINUE INTO TONIGHT OVER THE KERN
COUNTY MOUNTAINS AND DESERT. HIGH PRESSURE WILL BE BUILD OVER THE
DISTRICT DURING THE NEXT FEW DAYS AND BRING MOSTLY CLEAR SKIES AND
A DAY TO DAY WARMING TREND THROUGH MIDWEEK.
&&
.DISCUSSION...OBSERVATIONS FROM MESONET SITES SHOW THE WIND HAS
NOT REACHED ADVISORY LEVELS OVER THE KERN COUNTY MOUNTAINS IN
CONTRAST TO BOTH THE HRRR AND NAMDNG5 MODELS SHOWING STRONGER VALUES.
THE ADVISORY HAS BEEN CANCELLED. NO OTHER CHANGES TO THE GRIDS AS
THE WARMING TREND REMAINS ON TRACK.
&&
.AVIATION...
MVFR WITH LOCAL MTN OBSCURING IFR CONDITIONS WILL PERSIST ALONG THE
WEST SLOPES OF THE SIERRA AND THE NORTH FACING SLOPES OF THE
TEHACHAPI MOUNTAINS THROUGH 06Z MONDAY. VFR CONDITIONS WILL PREVAIL
ELSEWHERE ACROSS THE CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24
HOURS. ADDITIONALLY...WINDS OF 35 KNOTS OR GREATER WILL CONTINUE
THROUGH AND JUST BELOW THE MOUNTAIN PASSES OF KERN COUNTY UNTIL 12Z
MONDAY.
&&
.PREV DISC... /ISSUED 224 PM PDT SUN APR 27 2014/
DISCUSSION...THE LATE APRIL SUN HAS PRODUCED SIGNIFICANT WARMING
TODAY. TEMPERATURES ARE TRENDING A GOOD 5 TO 15 DEGREES HIGHER
THROUGHOUT THE CWA THIS AFTERNOON COMPARED TO SATURDAY AFTERNOON.
THE WARMING TREND WILL CONTINUE UNDAUNTED THROUGH THE MIDDLE OF
THIS WEEK AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDS OVER
CA. THE RIDGE HAS ALREADY BUILT UP ENOUGH TODAY TO THWART THE
SOUTHEASTWARD MOVEMENT OF A WEAK COLD FRONT THAT EXTENDS FROM
REDDING TO THE SFO BAY AREA TO JUST OFFSHORE THE SOUTHERN CA
COAST. SUBSIDENCE ASSOCIATED WITH THIS BUILDING HIGH PRESSURE
RIDGE HAS EVAPORATED MUCH OF THE MOISTURE ASSOCIATED WITH THIS
FRONT THIS AFTERNOON. MEANWHILE...LEFTOVER MOISTURE FROM OUR
RECENT STORM IS SHOWING UP AS STRATOCUMULUS THAT HAS REMAINED
BANKED UP IN THE ONSHORE FLOW ALONG THE WEST SLOPES OF THE
MOUNTAINS IN TULARE COUNTY AND KERN COUNTY THIS AFTERNOON.
ALTHOUGH THE ONSHORE FLOW HAS WEAKENED SOME SINCE SATURDAY...IT
WILL SUPPORT A SHALLOW PUSH OF MARINE AIR INTO THE SJ VLY THIS
EVENING. WEST WINDS BLOWING THROUGH AND BELOW THE MOUNTAIN PASSES
OF KERN COUNTY HAVE NOT YET PEAKED ABOVE ADVISORY LEVELS BUT ARE
GRADUALLY INCREASING...SO WILL LET THE WIND ADVISORY FOR THIS
REGION CONTINUE INTO THIS EVENING. THE ONSHORE FLOW IS FORECAST
TO SLOWLY DIMINISH DURING THE NEXT 24 HRS THEN BECOME OFFSHORE BY
TUESDAY WHILE THE UPPER LEVEL RIDGE AMPLIFIES ALONG THE WEST COAST.
TEMPERATURES WILL RECOVER TO SEASONABLE LEVELS MONDAY AFTERNOON.
THE REMAINDER OF THE 7 DAY PERIOD WILL BE DRY AND SUBSTANTIALLY
WARMER. MAX TEMPS WILL BE ABOVE 90 DEGREES IN THE SJ VLY AND
LOWER FOOTHILLS BY WEDNESDAY AND WELL INTO THE 90S THURSDAY AND
FRIDAY BEFORE TRENDING DOWNWARD A BIT NEXT WEEKEND AS THE HIGH
PRESSURE RIDGE WEAKENS.
ON A FINAL NOTE...THE 12Z RUN OF THE ECM AND GFS FORECAST ANOTHER
DEEP UPPER LEVEL TROUGH TO MOVE INTO CA BETWEEN THE 6TH AND 7TH OF
MAY. WHETHER OR NOT THIS FEATURE BRINGS SHOWERS...IF ANY...IS
SOMETHING WE ARE NOT CONFIDENT OF AT ALL. WHAT IS MORE CERTAIN IS
THAT TEMPERATURES WILL PROBABLY TREND COOLER DURING THIS PERIOD
..AT LEAST CLOSER TO NORMAL.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS HIGH.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 04-27 98:2004 56:1894 65:1926 36:1955
KFAT 04-28 98:2007 50:1906 65:1987 36:1970
KFAT 04-29 96:1981 60:1951 65:1992 35:1970
KBFL 04-27 98:2004 60:1932 67:1965 34:1984
KBFL 04-28 97:2007 54:1906 66:1965 38:1999
KBFL 04-29 100:1981 61:1967 64:2007 40:1984
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...DUDLEY
AVN/FW...BEAN
PREV DISCUSSION...DURFEE
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
856 PM MDT SUN APR 27 2014
.UPDATE...
ISSUED AT 856 PM MDT SUN APR 27 2014
UPDATED FOR LATEST OBS...SATELLITE AND RADAR TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 327 PM MDT SUN APR 27 2014
CURRENTLY...STRONG UPPER LEVEL AND SURFACE LOW PRESSURE STACKED OVER
NORTHWESTERN KS WITH SOUTHERN END OF WRAP AROUND DEFORMATION PRECIP
SLOWLY WEAKENING OVER SOUTHEAST CO. FARTHER WEST...LAPS SURFACE
PRESSURE DATA SHOWS WEAK SECONDARY LOW PRESSURE NEAR KPUB...WHICH
HAS CREATED LIGHTER WINDS OVER MUCH OF PUEBLO COUNTY THIS
AFTERNOON...AND HAS IN GENERAL WEAKENED THE PRESSURE GRADIENT ACROSS
SOUTHEAST COLORADO. WITH CONVECTION ENDING AND STRONG SURFACE
GRADIENT LACKING...WIND SPEEDS HAVE BEGUN TO VERY SLOWLY DECREASE
ACROSS THE PLAINS...AND STRONGEST GUSTS HAVE FALLEN BACK INTO THE 40-
45 KT RANGE. LATEST HRRR SUGGESTS WIND SPEEDS HAVE ALREADY
PEAKED...AND GIVEN LACK OF OBSERVED 50 KT GUSTS...WILL CANCEL THE
HIGH WIND WARNING FOR THE FAR SOUTHEAST. OVER THE MOUNTAINS...STILL
SOME -SHSN OVER THE CONTINENTAL DIVIDE...THOUGH WEB CAMS SUGGEST
LITTLE IN THE WAY OF ACCUMULATION OR LOW VISIBILITY...AT LEAST AT
PASS LEVEL.
TONIGHT...WILL KEEP SOME LOW POPS IN THE EVENING TO ACCOUNT FOR
LINGERING -SHRA OVER THE SOUTHEAST PLAINS...WITH SOME HIGHER POPS
FOR THE CENTRAL MOUNTAINS ALONG THE CONTINENTAL DIVIDE...WHERE
SECONDARY UPPER WAVE WILL LIKELY HELP INCREASE -SHSN COVERAGE LATER
TONIGHT. EXPECT WINDS TO GRADUALLY DIMINISH ALL AREAS THROUGH THE
NIGHT...THOUGH MANY LOCATIONS WILL STAY BREEZY AS STRONG WINDS JUST
OFF THE SURFACE PERSIST. EXPECTING ENOUGH IN THE WAY OF WINDS/CLOUDS
TO KEEP PLAINS FROM A HARD FREEZE...THOUGH MOST MOUNTAINS AND HIGH
VALLEYS WILL DROP INTO THE 20S OR COLDER.
MONDAY...UPPER LOW VERY SLOWLY DRIFTS INTO ERN NEBRASKA DURING THE
DAY...KEEPING STRONG NW FLOW AT THE SURFACE AND ALOFT ACROSS MOST OF
SOUTHERN COLORADO. EXPECT WINDS TO INCREASE ALL AREAS BY MID
MORNING...WITH GUSTS IN THE 30-40 KT RANGE MOST LOCATIONS BY
AFTERNOON. GIVEN RATHER COLD AIR ALOFT/STEEP LAPSE RATES IN PLACE
MON AFTERNOON...SUSPECT AT LEAST ISOLATED RAIN AND SNOW SHOWERS WILL
DEVELOP OVER THE MOUNTAINS...WITH PERHAPS A FEW SPRINKLES/LIGHT
SHOWERS OVER LOWER ELEVATIONS LATE IN THE DAY. LOW LEVELS WILL BE
FAIRLY DRY...WHICH WILL KEEP PRECIP AMOUNTS LIGHT. MAX TEMPS WILL
REMAIN COOL...WITH BLENDED NUMERICAL GUIDANCE LOOKING OK FOR HIGHS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 327 PM MDT SUN APR 27 2014
VERY UNSETTLED PATTERN QUEUED UP FOR THE FORECAST AREA THROUGH THE
EXTENDED FORECAST...BUT MODELS ARE LEANING TOWARDS TWO SEPARATE
PERIODS OF WEATHER TYPES.
MONDAY NIGHT THROUGH THURSDAY...LONG RANGE MODELS INDICATE THAT THE
UPPER LOW PRESSURE SYSTEM WILL PINWHEEL ABOUT THE US CENTRAL PLAINS
AND UPPER MISSISSIPPI RIVER VALLEY THROUGH THU...BEFORE FINALLY
EJECTING TO THE NE ACROSS THE GREAT LAKES. THIS SOLUTION WILL KEEP
VERY BRISK AND COOL NORTHERLY FLOW IN PLACE FOR THE STATE INTO
THU...AS WELL AS A DAILY SHOT OF SHOWER ACTIVITY FOR THE CWA. AS THE
LOW LINGERS...LOBES OF ENERGY WILL ROTATE AROUND THE SYSTEM AND
BRING PERIODICALLY BETTER CHANCES FOR SHOWERS...THOUGH THE EXACT
TIMING OF THESE WINDOWS IS NEAR IMPOSSIBLE TO PREDICT AT THIS TIME.
LOOK FOR MAX TEMPS EACH DAY IN THE 50S TO AROUND 60 F FOR THE LOWER
ELEVATIONS...AND 30S TO 40S FOR THE MTS. THE HIGHER TERRAIN IS
EXPECTED TO EXPERIENCE ISOLATED TO LOW END SCATTERED POPS THROUGH
THU...WITH THE BEST SHOT OF SOME ISOLATED CONVECTION FOR THE PLAINS
COMING TUE AFTN...AND AGAIN WED AFTN AND EVE.
FRIDAY THROUGH SUNDAY...THE GFS AND EC MODELS HINT THAT BY FRI THE
UPPER LOW WILL FINALLY BE PULLING AWAY FROM THE REGION...ALLOWING
THE UPPER FLOW TO SHIFT TO A MORE WESTERLY DIRECTION INTO THE
WEEKEND. BOTH MODELS DO CONTINUE TO SHOW MEAGER SHOWER ACTIVITY BOTH
FRI AND SAT...MAINLY TIED TO THE HIGHER TERRAIN...BUT FEEL THAT THIS
FAR OUT THIS MAY BE A BIT OVERDONE. BY SUNDAY PCPN SHOULD COME TO AN
END. LOOK FOR A WARMING TREND INTO THE WEEKEND AS THE UPPER FLOW
SHIFTS...WITH MAX TEMPS IN THE 60S FOR FRI...THEN 70S FOR BOTH SAT
AND SUN. MOORE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 327 PM MDT SUN APR 27 2014
EXPECT VFR CONDITIONS ALL TAF SITES TONIGHT AND MONDAY. GUSTY WINDS
AT KCOS AND KALS WILL GRADUALLY DIMINISH AFTER 02Z...THOUGH W-NW
WINDS IN THE 10-15 KT RANGE MAY PERSIST THROUGH THE NIGHT. ON
MON...NW WINDS WILL INCREASE QUICKLY DURING THE MORNING...WITH GUSTS
TO 25 KTS ALL TERMINALS BY 16Z...THEN A FEW GUSTS IN THE 30-35 KT BY
20Z. MAY SEE SOME VIRGA/-SHRA OVER THE MOUNTAINS DRIFT TOWARD KCOS
AND KALS AFTER 20Z AS WELL...THOUGH NOT EXPECTING ANY CIG/VIS
RESTRICTIONS.
OVER THE MOUNTAINS...-SHSN WILL PERSIST THROUGH THE
NIGHT...ESPECIALLY NORTH OF MONARCH PASS...WHERE AREAS OF IFR
CONDITIONS WILL BE POSSIBLE THROUGH 12Z. ON MON...SHOWERS WILL
REDEVELOP WITH PEAKS BECOMING OBSCURED MANY AREAS AFTER 18Z.
OVER THE PLAINS...-SHRA WILL CONTINUE TO DIMINISH THROUGH THE
EVENING WITH VFR CONDITIONS ALL AREAS BY 02Z. WINDS WILL ALSO SLOWLY
DIMINISH THROUGH THE EVENING.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MW
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1006 PM EDT SUN APR 27 2014
.SYNOPSIS...
THE UPPER LEVEL DISTURBANCE THAT BROUGHT SHOWERS TO SOUTHERN NEW
ENGLAND YESTERDAY AND TODAY WILL CONTINUE TO MOVE OFFSHORE.
MAINLY DRY CONDITIONS WILL FOLLOW TOMORROW INTO TUESDAY AS HIGH
PRESSURE RETURNS TO THE AREA. LOW PRESSURE WILL BRING A SOAKING
RAIN WED INTO THU. SEASONABLE WEATHER IS THEN EXPECTED FRI INTO
NEXT WEEKEND WITH DRY WEATHER LIKELY DOMINATING...OTHER THAN A FEW
SPOT SHOWERS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
10 PM UPDATE...
STILL A SMALL AREA OF SHOWERS ROTATING SOUTH ACROSS SE MA AND E
RI. HRRR SHOWS THESE SHOWERS DISSIPATING BY MIDNIGHT LEAVING DRY
CONDITIONS OVERNIGHT. STRATOCU MOVING ACROSS THE REGION BUT THERE
ARE NUMEROUS BREAKS. EXPECT PTCLDY SKIES WITH AN INCREASE IN MID
LEVEL CLOUDS LATE ACROSS THE E. GENERALLY LIGHT WINDS ACROSS THE
REGION SO SOME OPPORTUNITY FOR RADIATIONAL COOLING WHERE SKIES
CLEAR. EXPECT MINS MOSTLY IN THE MID 30S TO NEAR 40.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
TOMORROW...
BLOCKING OMEGA HIGH WILL BEGIN TO SLIDE E FROM THE GREAT LAKES AND
SE CONUS AS ATTENDANT SFC HIGH PRES FORCES AN INVERTED HIGH PRES
RIDGE ACROSS SRN NEW ENGLAND. THIS WILL YIELD A DRY FORECAST...BUT
WITH CONTINUATION OF MID AND HIGH CLOUDS ACROSS THE E AS MOISTURE
CONTINUES TO STREAM FROM CANADA ON THE PERIPHERY OF THE BLOCK.
H85 TEMPS WARM TO ABOUT 0C...SO EVEN WITH FULL MIXING HIGH TEMPS
WILL STILL REMAIN SLIGHTLY BELOW NORMAL FOR LATE APRIL...MAINLY IN
THE UPPER 50S TO AROUND 60...WHICH IS AT LEAST WARMER THAN IT WAS
OVER THE WEEKEND. THE CAVEAT WILL BE NEAR COASTAL LOCATIONS AS A
NORTHEASTERLY DRAW DEVELOPS WITH THE INVERTED RIDGE...KEEPING
ESPECIALLY E COASTAL LOCATIONS IN THE LOWER 50S.
MON NIGHT...
ONE LAST DIVING SHORTWAVE OUT OF CANADA AND WEAK WARM ADVECTION
AND MOISTURE FLUX MAY LEAD TO AN ISOLATED -SHRA WITHIN THE
WEAKENING INVERTED RIDGE. KEPT POPS AT SLIGHT CHANCE AS THESE ARE
LIKELY TO BE WIDELY SCT AT BEST. OTHERWISE...MANY MORE CLOUDS
EXPECTED. THEREFORE...MINS WILL BE MILD MAINLY IN THE LOW-MID 40S
AT THEIR COLDEST.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...
* MAINLY DRY AND COOL WEATHER TUESDAY
* RAINY AND COOL WEATHER WEDNESDAY
* MILDER THURSDAY BUT STILL WET
* SEASONABLE FRIDAY INTO NEXT WEEKEND W/DRY WEATHER DOMINATING
DETAILS...
TUESDAY...
STRONG HIGH PRESSURE OVER EASTERN CANADA WILL COMBINED WITH A LOW
PRESSURE SYSTEM WELL TO OUR WEST. MAINLY DRY WEATHER IS ANTICIPATED
ON TUESDAY OTHER THAN THE LOW RISK FOR A BRIEF SPOT SHOWER OR TWO
ACROSS THE INTERIOR. EASTERLY WINDS WILL RESULT IN UNSEASONABLY
COOL HIGH TEMPS ESPECIALLY NEAR THE EASTERN MA COAST. HIGHS MAINLY
IN THE UPPER 40S ALONG THE EASTERN MA COAST...TO PERHAPS THE LOWER
TO MIDDLE 50S IN THE DISTANT INTERIOR. PLENTY OF CLOUDS AROUND BUT
MAY SEE SOME PEEKS OF SUN WITH BEST CHANCE NEAR THE COAST...AS DRY
AIR TRIES TO ACTUALLY COME IN OFF THE OCEAN.
TUESDAY NIGHT...
UPPER LEVEL RIDGING AND DRY LOW LEVEL AIR WILL SLOW THE ADVANCING
LOW PRESSURE/RAIN SHIELD TO OUR WEST. WHILE WE MAY SEE A FEW
SHOWERS TUE NIGHT WITH THE BEST CHANCE ACROSS THE INTERIOR...MUCH OF
THE NIGHT MAY TURN OUT DRY. IT WILL BE COOL...WITH LOW TEMPS MAINLY
IN THE 30S TO THE LOWER 40S.
WEDNESDAY AND THURSDAY...
STRENGTHENING LOW LEVEL JET ON WEDNESDAY WILL FINALLY ALLOW THE
COLUMN TO SATURATE AND A SOAKING RAIN TO DEVELOP. STILL
DISAGREEMENT AMONGST THE MODELS ON WHEN THIS HAPPENS...BUT TREND
WILL BE FOR WET WEATHER TO OVERSPREAD THE REGION FROM WEST TO EAST
ON WEDNESDAY. LOW LEVEL JET/PWATS EXPECTED TO BE 2 TO 3 STANDARD
DEVIATIONS ABOVE NORMAL. THIS SHOULD YIELD TO A PERIOD OF HEAVY
RAIN WEDNESDAY INTO THURSDAY. AT THIS TIME...LOOKS LIKE THE
HEAVIEST OF THE RAIN WILL BE TO OUR SOUTHWEST WHERE BETTER
MOISTURE/INSTABILITY COINCIDE. NONETHELESS...WE MAY SEE 1 TO 2
INCHES OF RAINFALL LEADING TO A PERIOD OF NUISANCE/MINOR POOR
DRAINAGE STREET FLOODING. INSTABILITY IS RATHER MARGINAL IN OUR
REGION...BUT LOW PROBABILITY FOR AN ISOLATED THUNDERSTORM OR TWO ON
THURSDAY IF PORTIONS OF THE REGION CAN WARM SECTOR.
AS FOR TEMPS...UNSEASONABLY COOL ON WEDNESDAY WITH EASTERLY FLOW
HOLDING HIGHS MAINLY IN THE 40S TO AROUND 50. TEMPS UNCERTAIN ON
THURSDAY...BUT IF WE CAN WARM SECTOR SOME OF THE AREA COULD BREAK
INTO THE 60S BY LATE IN THE DAY.
FRIDAY THROUGH SUNDAY...
OVERALL WEATHER LOOKS RATHER SEASONABLE OVER THIS TIME FRAME. A FEW
SHORTWAVES MAY BRING A COUPLE OF SPOT SHOWERS..BUT MUCH OF THIS
PERIOD WILL PROBABLY END UP DRY.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...HIGH CONFIDENCE
THROUGH OVERNIGHT TONIGHT...
SCT SHOWERS WILL DISSIPATE ACROSS SE MA AND RI. OTHERWISE...VFR
CONDITIONS EXPECTED. SOME NNW WIND GUSTS TO 20 KT DEVELOPING
ACROSS E COASTAL MA AND CAPE COD LATE TONIGHT.
MON AND MON NIGHT... MAINLY VFR DURING THE DAY. WINDS ONCE AGAIN
SHIFT TO THE NE...WHICH LOOKS TO ALLOW ANOTHER ROUND OF MVFR CIGS
/ESPECIALLY E OF THE WORCESTER HILLS AND MONADNOCKS/ DURING THE
OVERNIGHT HOURS.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...TUESDAY THROUGH FRIDAY...
TUESDAY AND TUESDAY NIGHT...MODERATE CONFIDENCE. VFR TO MVFR
CEILINGS EXPECTED AT TIMES.
WEDNESDAY AND THURSDAY...MODERATE CONFIDENCE. PERIODS OF MVFR-IFR
CONDITIONS IN RAIN...LOWER CLOUDS AND FOG PATCHES.
FRIDAY...LOW TO MODERATE CONFIDENCE. VFR CONDITIONS DOMINATE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH TOMORROW NIGHT...HIGH CONFIDENCE.
MAINLY QUIET BOATING WEATHER THIS EVENING WILL GIVE WAY TO
INCREASING NW WINDS AND SEAS ON THE ERN OCEAN WATERS. SMALL CRAFT
ADVISORY CONDITIONS ARE EXPECTED AS WINDS REACH AROUND 25 KT AT
TIMES AND SEAS OF 5-6 FT ARE POSSIBLE. ALTHOUGH THE WINDS WILL
DIMINISH AS THEY SHIFT BACK TO THE NE DURING THE DAY TOMORROW...A
BUILDING SWELL MAY REQUIRE THAT THIS ERN SCA CONTINUE THROUGH MUCH
OF THE DAY TOMORROW.
BY TOMORROW NIGHT...ONCE E-NE WINDS HAVE DEVELOPED ANOTHER THREAT
FOR GUSTS TO AROUND 25 KT AND CONTINUED BUILDING ELY SWELL MAY
NEED A MORE WIDESPREAD SCA FOR THE NEAR COASTAL WATERS AS WELL AS
SOME OF THE S COASTAL WATERS.
OUTLOOK...TUESDAY INTO FRIDAY...
TUESDAY AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE. HIGH PRESSURE
OVER EASTERN CANADA AND LOW PRESSURE WELL TO OUR WEST WILL RESULT IN
AN INCREASING PRESSURE GRADIENT. EAST TO NORTHEAST WIND GUSTS OF 25
TO 30 KNOTS ARE EXPECTED OVER THE OPEN WATERS MUCH OF THIS TIME. IN
ADDITION...LONG EAST FETCH WILL BUILD SEAS WELL ABOVE SCA
THRESHOLDS. MOST OF THE RAIN AND FOG SHOULD HOLD OFF UNTIL WED/WED
NIGHT.
THURSDAY...MODERATE CONFIDENCE. WINDS GRADUALLY TURN SOUTH ON
THURSDAY AS AREA ENTERS THE WARM SECTOR...BUT MAY TAKE UNTIL LATE
THU/THU NIGHT ACROSS THE NORTHERN WATERS. SCA WIND GUSTS STILL
POSSIBLE...ALONG WITH SHOWERS AND AREAS OF FOG. SEAS WILL REMAIN
HIGH ACROSS THE OPEN WATERS.
FRIDAY...LOW CONFIDENCE. SCA SEAS LINGER AT LEAST OVER THE OUTER-
WATERS BUT WIND SPEEDS/DIRECTION VERY UNCERTAIN.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 5 PM EDT MONDAY FOR ANZ250-
254-255.
&&
$$
SYNOPSIS...FRANK/DOODY
NEAR TERM...KJC
SHORT TERM...DOODY
LONG TERM...FRANK
AVIATION...FRANK/DOODY
MARINE...FRANK/DOODY
AREA FORECAST DISCUSSION
NWS ALBANY NY
157 PM EDT SAT APR 26 2014
.SYNOPSIS...
A COMPLEX LOW PRESSURE SYSTEM WILL IMPACT OUR REGION
THIS AFTERNOON...AS IT SLOWLY DRIFTS NORTHEAST. AN UPPER LEVEL LOW
WILL IMPACT THE REGION TONIGHT INTO TOMORROW BRINGING ANOTHER PERIOD
OF RAIN SHOWERS. DRIER WEATHER AND MILDER TEMPERATURES WILL RETURN
BY MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1058 AM EDT...THE OCCLUDED FRONT ASSOCIATED WITH THE DOUBLE
BARREL LOW PRESSURE SYSTEM HAS MOVED THROUGH THE ERN PORTION OF
THE FCST AREA LATE MORNING. A FEW LINGERING SHOWERS/DRIZZLE ARE
LINGERING OVER THE SRN GREENS AND BERKSHIRES. THE SATELLITE
PICTURE IS SHOWING SOME CLEARING OVER CNTRL AND SRN NY. THIS
SHOULD MAKE ITS WAY INTO THE SRN PORTIONS OF THE FCST AREA FOR THE
EARLY PM WITH SOME PARTIAL SUNSHINE. A BATCH OF SHOWERS AHEAD OF
THE CLOSED UPPER LEVEL LOW OVER GEORGIAN BAY/SE ONTARIO ACCORDING
TO THE RUC40/RR WILL BRING SHOWERS BACK INTO THE FCST AREA IN THE
MID TO LATE PM. THERE COULD BE A FEW RUMBLES OF THUNDER OVER THE
SE EXTREME /ULSTER...DUTCHESS...AND LITCHFIELD COUNTIES/. THE
LAPSE RATES STEEPEN...AND THERE ARE SMALL AMOUNTS OF INSTABILITY
FORECASTED /LESS 250 J/KG/. A SLIGHT CHC OF TSRAS WAS ADDED THERE.
THE LATEST HRRR 3-KM COLUMNAR REF PRODUCT INDICATES THE THREAT FOR
SHOWERS INCREASES OVER THE MAJORITY OF THE FCST AREA BTWN 20Z-23Z.
POPS WERE KEPT IN THE HIGH CHC AND LIKELY CATEGORY.
HIGHS TODAY ARE EXPECTED TO BE A TAD ON THE COOL SIDE MAINLY
RANGING FROM THE UPPER 40S OVER THE SRN DACKS TO L60S IN THE MID
HUDSON VALLEY. TEMPS WERE LOWERED INTO THE U40S TO L50S OVER
PORTIONS OF THE SRN GREENS/NRN BERKS WHERE THE CLOUDS MAY LINGER
THE LONGEST IN THE RAIN COOLED AIR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE UPPER LEVEL LOW IS CENTERED OVER THE FA THIS EVENING WITH A
STRONG VORT LOBE PASSING ACRS THE FA AS WELL. THIS SHOULD RESULT IN
MORE SHOWERS WHICH WILL LINGER INTO SUNDAY MORNING AS THE VORT
LOBE DOES NOT DRIFT OFF THE EAST COAST UNTIL SUNDAY AFTERNOON.
THUS EXPECT THE SECOND HALF OF SUNDAY TO BE DRIER THAN THE FIRST
HALF OF THE DAY. EXPECT LOWS TONIGHT IN THE 30S WITH THE HIGHS ON
SUNDAY IN THE UPPER 40S NORTHWEST TO AROUND 60 SOUTHEAST.
HIGH PRESSURE WILL BUILD INTO THE FA FOR LATER SUNDAY NIGHT INTO
MONDAY WITH MAINLY DRY CONDITIONS. LOWS SUNDAY NIGHT WILL BE IN
THE UPPER 20S NORTHWEST TO MID 30S SOUTHEAST. HIGHS ON MONDAY ARE
EXPECTED TO BE MILDER THAN OVER THE WEEKEND WITH HIGHS RANGING
FROM THE MID 50S NORTHWEST TO MID 60S SOUTHEAST.
MONDAY NIGHT WILL FEATURE INCREASING CLOUDS AS A STORM SYSTEM
APPROACHES FROM THE GREAT LAKES REGION. EXPECT LOWS TO BE IN THE
MID 30S TO MID 40S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
UNSETTLED CONDITIONS APPEAR TO DOMINATE MUCH OF THE LONG TERM
PERIOD...ALTHOUGH THERE REMAINS SOME UNCERTAINTY AS TO HOW FAST THIS
UNSETTLED WEATHER DEVELOPS...AND HOW LONG IT WILL LINGER. MOST
00Z/26 DETERMINISTIC AND ENSEMBLE GUIDANCE INDICATE A RATHER BLOCKY
PATTERN IN PLACE AT THE START OF THE LONG TERM PERIOD...WITH A
SPRAWLING MID/UPPER LEVEL LOW ACROSS THE CENTRAL U.S...WITH ANOTHER
CLOSED MID/UPPER LEVEL LOW MOVING EAST WELL OFF THE NEW ENGLAND
COAST. IN BETWEEN THESE TWO FEATURES WILL BE A STRONG BUT SOMEWHAT
NARROW RIDGE OF HIGH PRESSURE. THIS RIDGE MAY THWART THE
EAST/NORTHEAST PROGRESS OF THE RAIN INITIALLY INTO THE
REGION...BEFORE RAIN CHANCES ARE MAXIMIZED AROUND THE LATE WED-EARLY
THU TIME PERIOD. TEMPS SHOULD REMAIN BELOW SEASONAL LEVELS GIVEN THE
PROSPECTS FOR CLOUDS...AND AT LEAST SOME RAINFALL DURING THE PERIOD.
THE STEADIEST RAINFALL MAY LIFT N AND E OF THE REGION BY LATE THU OR
FRI...TRANSITIONING TO A MORE SHOWERY REGIME AS THE LINGERING
MID/UPPER LEVEL COLD POOL MOVES CLOSER TO THE REGION.
HERE ARE SOME MORE SPECIFICS...
TUE-TUE NT...AS MENTIONED ABOVE...THERE REMAINS SOME QUESTION AS TO
HOW FAST THE MID/UPPER LEVEL RIDGE AXIS MOVES E OF THE
REGION...ALLOWING FOR INCREASING ISENTROPIC LIFT AND RAINFALL ACROSS
THE REGION. AT THIS TIME...WILL SIDE ON THE SLOWER SIDE OF
GUIDANCE...KEEPING MOST AREAS DRY TUE AM...THEN SLOWLY INCREASING
POPS INTO THE SLIGHT CHC RANGE FOR EASTERN AREAS...AND LOW CHC RANGE
FOR CENTRAL AND WESTERN AREAS BY LATE TUE. FOR TUE NT...WILL
CONTINUE TO INCREASE POPS GRADUALLY INTO THE HIGHER CHC RANGE. AS
FOR TEMPS...SIDING ON THE SLOWER SIDE OF GUIDANCE...HAVE INDICATED
SLIGHTLY WARMER MAX TEMPS FOR TUE...WITH 50S IN MOST AREAS...WITH
PERHAPS EVEN SOME LOWER 60S POSSIBLE ACROSS NORTHERN VALLEY AREAS
SHOULD THE RAIN HOLD OFF AND ANY MORNING SUNSHINE OCCUR. EXPECT
LOWER 40S IN VALLEYS...AND 35-40 ACROSS HIGHER ELEVATIONS AND
NORTHERN AREAS FOR TUE NT.
WED-THU...CHC POPS EARLY WED HAVE BEEN RAISED TO LIKELY POPS FOR
LATE WED INTO EARLY THU...WHICH APPEARS TO BE THE BEST OPPORTUNITY
FOR WIDESPREAD RAINFALL GIVEN THE GREATEST ISENTROPIC LIFT AND
MOISTURE TRANSPORT INTO AND ACROSS THE REGION. THE 00Z/26 GEFS
ACTUALLY HINT AT SOME CHC FOR HEAVY RAIN ACROSS PORTIONS OF THE MID
HUDSON VALLEY AND NW CT...WHERE THE PROB FOR ONE INCH OR GREATER
OVER A 24 HOUR PERIOD IS IN THE 40-60 PERCENT RANGE THROUGH
18Z/THU...WITH EVEN A 20-40 PERCENT CHANCE FOR 2 INCHES OR MORE OVER
A 36 HOUR PERIOD ALSO ENDING 18Z/THU. EXPECT MAX TEMPS TO MAINLY
REMAIN IN THE LOWER/MID 50S...WITH SOME UPPER 40S POSSIBLE IN HIGHER
ELEVATIONS WED. BY LATE THU...IT IS POSSIBLE THAT THE STEADIEST RAIN
BEGINS TO TAPER TO SHOWERS. HAVE INDICATED SLIGHTLY WARMER MAXES
COMPARED TO WED...WITH 50S AND LOWER 60S IN VALLEYS. WED NT/THU AM
MINS SHOULD MAINLY BE IN THE 40S...WITH SOME 30S POSSIBLE ACROSS
HIGHER ELEVATIONS.
THU NT-FRI...THE BEST FORCING APPEARS TO SHIFT MAINLY N AND E OF THE
REGION. HOWEVER...WITH THE APPROACH OF THE LINGERING MID LEVEL COLD
POOL...EXPECT AT LEAST SOME ISOLATED TO SCATTERED RAIN SHOWERS TO
OCCUR...ESP DURING FRI AFTN. MAX TEMPS SHOULD REACH THE LOWER 60S IN
VALLEYS...WITH 50S ACROSS MOST HIGHER ELEVATIONS. THU NT/FRI AM MINS
SHOULD FALL INTO THE 40S IN VALLEYS...AND MID 30S TO NEAR 40 ACROSS
NORTHERN AREAS...AND HIGHER TERRAIN.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A STRONG UPPER LEVEL DISTURBANCE ASSOCIATED WITH A CLOSED
UPPER LEVEL APPROACHING FROM SE ONTARIO WILL BRING SHOWERS BACK
INTO THE ERN NY AND WRN NEW ENGLAND TERMINALS LATE THIS AFTERNOON
INTO THIS EVENING. THE UPPER LEVEL LOW WILL MOVE EAST TO SOUTHEAST
OF NEW ENGLAND ON SUNDAY WITH LINGERING CLOUDS AND ISO-SCT SHOWERS
AROUND THROUGH THE MORNING.
VFR CONDITIONS WILL BE SHORT-LIVED FOR KALB/KPOU/KGFL/KPSF IN THE
EARLY TO MID PM...BEFORE THE NEXT ROUND OF SHOWERS ARRIVES. THERE
MAY EVEN BE A RUMBLE OF THUNDER AROUND NEAR KPOU...BUT THE
PROBABILITY WAS NOT GREAT ENOUGH TO INCLUDE IN THE TERMINALS. THE
SHOWERS ARRIVE BTWN 20Z-22Z...AND LINGER UNTIL 02Z-05Z/SUN. CIGS
AND VSBYS WILL GENERALLY BE IN THE MVFR RANGE...BUT IFR CIGS/VSBYS
WERE INCLUDED AT KPSF...ESPECIALLY FOR LOW STRATUS IN THE SHOWERS
PRIOR TO MIDNIGHT. THE RESIDUAL LOW-LEVEL MOISTURE SHOULD LAST IN
THE BOUNDARY LAYER THROUGH THE OVERNIGHT PERIOD THERE...AND THE IFR
CIGS WERE KEPT IN THERE UNTIL 13Z/SUN. ELSEWHERE...MVFR CIGS IN
THE MOIST CYCLONIC FLOW WERE KEPT IN THE FCST FOR KGFL/KALB
THROUGH OVERNIGHT. KPOU SHOULD HAVE ENOUGH DRY AIR FILTERING IN
TO HAVE CIGS RISE TO THE VFR LEVELS BY 07Z/SUN. CIGS WILL GENERALLY
BE IN THE HIGH MVFR/VFR LEVELS BY 13Z-15Z/SUN AT ALL THE TERMINALS
WITH ISOLD-SCT INSTABILITY SHOWERS IN THE VICINITY.
THE WINDS WILL VARY FROM THE SW TO N AT LESS THAN 10 KTS THIS
AFTERNOON...THEN EXPECT A WIND SHIFT TO THE W TO NW AT 5-10 KTS
WITH THE UPPER LEVEL DISTURBANCE MOVING ACROSS THE REGION. N TO NW
WINDS WILL PERSIST OVERNIGHT INTO TOMORROW MORNING AT 10 KTS OR LESS.
OUTLOOK...
SUNDAY PM TO MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY-THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
A SOAKING RAIN OCCURRED OVERNIGHT ACROSS EASTERN NEW YORK AND
ADJACENT WESTERN NEW ENGLAND ALLEVIATING ANY FIRE WEATHER CONCERNS
FOR THE TIME BEING.
RELATIVE HUMIDITY VALUES WILL ONLY DROP TO 45 TO 60 PERCENT THIS
AFTERNOON...RECOVER TO 70 TO 100 PERCENT TONIGHT AND FALL TO 35 TO
55 PERCENT ON SUNDAY.
WINDS WILL BE SOUTHEAST TO NORTHEAST AT 5 TO 10 MPH TODAY...WEST
TO NORTHWEST AT 5 TO 10 MPH TONIGHT...AND NORTHWEST AT 10 TO 15
MPH WITH GUSTS TO 25 MPH SUNDAY AFTERNOON.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED DURING THE NEXT FIVE
DAYS.
SHOWERS OVERNIGHT HAVE BROUGHT MOST AREAS A QUARTER TO HALF AN
INCH WITH MORE RAIN SHOWERS EXPECTED LATER TODAY INTO TONIGHT WITH
ANOTHER TENTH TO THIRD OF AN INCH EXPECTED. ANY PRECIPITATION WILL
END BY SUNDAY AFTERNOON FOLLOWED BY DRY WEATHER THROUGH MONDAY
NIGHT. THE NEXT CHANCE OF PCPN WILL COME DURING THE MID WEEK PERIOD.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...KL/11/WASULA
SHORT TERM...11
LONG TERM...KL
AVIATION...WASULA
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
1059 AM EDT SAT APR 26 2014
.SYNOPSIS...
A COMPLEX LOW PRESSURE SYSTEM WILL IMPACT OUR REGION
THIS AFTERNOON...AS IT SLOWLY DRIFTS NORTHEAST. AN UPPER LEVEL LOW
WILL IMPACT THE REGION TONIGHT INTO TOMORROW BRINGING ANOTHER PERIOD
OF RAIN SHOWERS. DRIER WEATHER AND MILDER TEMPERATURES WILL RETURN
BY MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1058 AM EDT...THE OCCLUDED FRONT ASSOCIATED WITH THE DOUBLE
BARREL LOW PRESSURE SYSTEM HAS MOVED THROUGH THE ERN PORTION OF
THE FCST AREA LATE MORNING. A FEW LINGERING SHOWERS/DRIZZLE ARE
LINGERING OVER THE SRN GREENS AND BERKSHIRES. THE SATELLITE
PICTURE IS SHOWING SOME CLEARING OVER CNTRL AND SRN NY. THIS
SHOULD MAKE ITS WAY INTO THE SRN PORTIONS OF THE FCST AREA FOR THE
EARLY PM WITH SOME PARTIAL SUNSHINE. A BATCH OF SHOWERS AHEAD OF
THE CLOSED UPPER LEVEL LOW OVER GEORGIAN BAY/SE ONTARIO ACCORDING
TO THE RUC40/RR WILL BRING SHOWERS BACK INTO THE FCST AREA IN THE
MID TO LATE PM. THERE COULD BE A FEW RUMBLES OF THUNDER OVER THE
SE EXTREME /ULSTER...DUTCHESS...AND LITCHFIELD COUNTIES/. THE
LAPSE RATES STEEPEN...AND THERE ARE SMALL AMOUNTS OF INSTABILITY
FORECASTED /LESS 250 J/KG/. A SLIGHT CHC OF TSRAS WAS ADDED THERE.
THE LATEST HRRR 3-KM COLUMNAR REF PRODUCT INDICATES THE THREAT FOR
SHOWERS INCREASES OVER THE MAJORITY OF THE FCST AREA BTWN 20Z-23Z.
POPS WERE KEPT IN THE HIGH CHC AND LIKELY CATEGORY.
HIGHS TODAY ARE EXPECTED TO BE A TAD ON THE COOL SIDE MAINLY
RANGING FROM THE UPPER 40S OVER THE SRN DACKS TO L60S IN THE MID
HUDSON VALLEY. TEMPS WERE LOWERED INTO THE U40S TO L50S OVER
PORTIONS OF THE SRN GREENS/NRN BERKS WHERE THE CLOUDS MAY LINGER
THE LONGEST IN THE RAIN COOLED AIR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE UPPER LEVEL LOW IS CENTERED OVER THE FA THIS EVENING WITH A
STRONG VORT LOBE PASSING ACRS THE FA AS WELL. THIS SHOULD RESULT IN
MORE SHOWERS WHICH WILL LINGER INTO SUNDAY MORNING AS THE VORT
LOBE DOES NOT DRIFT OFF THE EAST COAST UNTIL SUNDAY AFTERNOON.
THUS EXPECT THE SECOND HALF OF SUNDAY TO BE DRIER THAN THE FIRST
HALF OF THE DAY. EXPECT LOWS TONIGHT IN THE 30S WITH THE HIGHS ON
SUNDAY IN THE UPPER 40S NORTHWEST TO AROUND 60 SOUTHEAST.
HIGH PRESSURE WILL BUILD INTO THE FA FOR LATER SUNDAY NIGHT INTO
MONDAY WITH MAINLY DRY CONDITIONS. LOWS SUNDAY NIGHT WILL BE IN
THE UPPER 20S NORTHWEST TO MID 30S SOUTHEAST. HIGHS ON MONDAY ARE
EXPECTED TO BE MILDER THAN OVER THE WEEKEND WITH HIGHS RANGING
FROM THE MID 50S NORTHWEST TO MID 60S SOUTHEAST.
MONDAY NIGHT WILL FEATURE INCREASING CLOUDS AS A STORM SYSTEM
APPROACHES FROM THE GREAT LAKES REGION. EXPECT LOWS TO BE IN THE
MID 30S TO MID 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
UNSETTLED CONDITIONS APPEAR TO DOMINATE MUCH OF THE LONG TERM
PERIOD...ALTHOUGH THERE REMAINS SOME UNCERTAINTY AS TO HOW FAST THIS
UNSETTLED WEATHER DEVELOPS...AND HOW LONG IT WILL LINGER. MOST
00Z/26 DETERMINISTIC AND ENSEMBLE GUIDANCE INDICATE A RATHER BLOCKY
PATTERN IN PLACE AT THE START OF THE LONG TERM PERIOD...WITH A
SPRAWLING MID/UPPER LEVEL LOW ACROSS THE CENTRAL U.S...WITH ANOTHER
CLOSED MID/UPPER LEVEL LOW MOVING EAST WELL OFF THE NEW ENGLAND
COAST. IN BETWEEN THESE TWO FEATURES WILL BE A STRONG BUT SOMEWHAT
NARROW RIDGE OF HIGH PRESSURE. THIS RIDGE MAY THWART THE
EAST/NORTHEAST PROGRESS OF THE RAIN INITIALLY INTO THE
REGION...BEFORE RAIN CHANCES ARE MAXIMIZED AROUND THE LATE WED-EARLY
THU TIME PERIOD. TEMPS SHOULD REMAIN BELOW SEASONAL LEVELS GIVEN THE
PROSPECTS FOR CLOUDS...AND AT LEAST SOME RAINFALL DURING THE PERIOD.
THE STEADIEST RAINFALL MAY LIFT N AND E OF THE REGION BY LATE THU OR
FRI...TRANSITIONING TO A MORE SHOWERY REGIME AS THE LINGERING
MID/UPPER LEVEL COLD POOL MOVES CLOSER TO THE REGION.
HERE ARE SOME MORE SPECIFICS...
TUE-TUE NT...AS MENTIONED ABOVE...THERE REMAINS SOME QUESTION AS TO
HOW FAST THE MID/UPPER LEVEL RIDGE AXIS MOVES E OF THE
REGION...ALLOWING FOR INCREASING ISENTROPIC LIFT AND RAINFALL ACROSS
THE REGION. AT THIS TIME...WILL SIDE ON THE SLOWER SIDE OF
GUIDANCE...KEEPING MOST AREAS DRY TUE AM...THEN SLOWLY INCREASING
POPS INTO THE SLIGHT CHC RANGE FOR EASTERN AREAS...AND LOW CHC RANGE
FOR CENTRAL AND WESTERN AREAS BY LATE TUE. FOR TUE NT...WILL
CONTINUE TO INCREASE POPS GRADUALLY INTO THE HIGHER CHC RANGE. AS
FOR TEMPS...SIDING ON THE SLOWER SIDE OF GUIDANCE...HAVE INDICATED
SLIGHTLY WARMER MAX TEMPS FOR TUE...WITH 50S IN MOST AREAS...WITH
PERHAPS EVEN SOME LOWER 60S POSSIBLE ACROSS NORTHERN VALLEY AREAS
SHOULD THE RAIN HOLD OFF AND ANY MORNING SUNSHINE OCCUR. EXPECT
LOWER 40S IN VALLEYS...AND 35-40 ACROSS HIGHER ELEVATIONS AND
NORTHERN AREAS FOR TUE NT.
WED-THU...CHC POPS EARLY WED HAVE BEEN RAISED TO LIKELY POPS FOR
LATE WED INTO EARLY THU...WHICH APPEARS TO BE THE BEST OPPORTUNITY
FOR WIDESPREAD RAINFALL GIVEN THE GREATEST ISENTROPIC LIFT AND
MOISTURE TRANSPORT INTO AND ACROSS THE REGION. THE 00Z/26 GEFS
ACTUALLY HINT AT SOME CHC FOR HEAVY RAIN ACROSS PORTIONS OF THE MID
HUDSON VALLEY AND NW CT...WHERE THE PROB FOR ONE INCH OR GREATER
OVER A 24 HOUR PERIOD IS IN THE 40-60 PERCENT RANGE THROUGH
18Z/THU...WITH EVEN A 20-40 PERCENT CHANCE FOR 2 INCHES OR MORE OVER
A 36 HOUR PERIOD ALSO ENDING 18Z/THU. EXPECT MAX TEMPS TO MAINLY
REMAIN IN THE LOWER/MID 50S...WITH SOME UPPER 40S POSSIBLE IN HIGHER
ELEVATIONS WED. BY LATE THU...IT IS POSSIBLE THAT THE STEADIEST RAIN
BEGINS TO TAPER TO SHOWERS. HAVE INDICATED SLIGHTLY WARMER MAXES
COMPARED TO WED...WITH 50S AND LOWER 60S IN VALLEYS. WED NT/THU AM
MINS SHOULD MAINLY BE IN THE 40S...WITH SOME 30S POSSIBLE ACROSS
HIGHER ELEVATIONS.
THU NT-FRI...THE BEST FORCING APPEARS TO SHIFT MAINLY N AND E OF THE
REGION. HOWEVER...WITH THE APPROACH OF THE LINGERING MID LEVEL COLD
POOL...EXPECT AT LEAST SOME ISOLATED TO SCATTERED RAIN SHOWERS TO
OCCUR...ESP DURING FRI AFTN. MAX TEMPS SHOULD REACH THE LOWER 60S IN
VALLEYS...WITH 50S ACROSS MOST HIGHER ELEVATIONS. THU NT/FRI AM MINS
SHOULD FALL INTO THE 40S IN VALLEYS...AND MID 30S TO NEAR 40 ACROSS
NORTHERN AREAS...AND HIGHER TERRAIN.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
MVFR/IFR CONDITIONS...WITH THE IFR MAINLY FOR CIGS...WILL PERSIST
AT THE TAF SITES THROUGH AROUND 13Z-14Z...AS AN OCCLUDED FRONT
PASSES EASTWARD...AND RAIN/DRIZZLE OCCURS. IN ITS WAKE...THE RAIN
SHOULD END...AND CIGS SHOULD LIFT INTO THE MVFR...THEN VFR RANGE
BY MID MORNING. A LULL IN THE RAIN IS THEN EXPECTED THROUGH EARLY
AFTERNOON.
THEN...AS A POTENT UPPER LEVEL DISTURBANCE APPROACHES FROM THE
WEST...SHOWERS WILL DEVELOP/INCREASE IN AREAL COVERAGE ONCE
AGAIN...ESP FROM THE KALB SOUTH TO KPOU AND EAST TO KPSF DURING
THE MID TO LATE AFTERNOON HOURS. SOME LOCALLY HEAVY SHOWERS COULD
BRIEFLY OCCUR...AND CAN NOT EVEN RULE OUT AN ISOLATED
THUNDERSTORM. HOWEVER...OVERALL CONFIDENCE IN THREAT FOR THUNDER
IS VERY LOW AT THIS TIME...SO NO MENTION OF TSRA IN CURRENT TAF
ISSUANCES. ANY HEAVIER SHOWERS COULD LEAD TO BRIEF AND LOCALIZED
MVFR/IFR VSBYS.
SHOWERS SHOULD DECREASE IN AREAL COVERAGE TONIGHT. HOWEVER...SOME
MVFR CIGS MAY PERSIST AT KGFL/KPSF/KALB.
WINDS AHEAD OF THE OCCLUDED FRONT WILL BE MAINLY LIGHT AND
VARIABLE...EXCEPT FROM THE SOUTH TO SOUTHEAST AT KALB AT 5-10 KT.
WINDS WILL THEN SHIFT INTO THE WEST TO SOUTHWEST BY MID MORNING AT
5-10 KT IN THE WAKE OF THIS FRONT...WITH SOME GUSTS POSSIBLY
REACHING 20 KT AT TIMES...ESP AT KALB AND KPSF. WINDS WILL SHIFT
INTO THE NORTHWEST TO NORTH TONIGHT AT GENERALLY 5-10 KT.
OUTLOOK...
SUNDAY TO MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
A SOAKING RAIN OCCURRED OVERNIGHT ACROSS EASTERN NEW YORK AND
ADJACENT WESTERN NEW ENGLAND ALLEVIATING ANY FIRE WEATHER CONCERNS
FOR THE TIME BEING.
RELATIVE HUMIDITY VALUES WILL ONLY DROP TO 45 TO 60 PERCENT THIS
AFTERNOON...RECOVER TO 70 TO 100 PERCENT TONIGHT AND FALL TO 35 TO
55 PERCENT ON SUNDAY.
WINDS WILL BE SOUTHEAST TO NORTHEAST AT 5 TO 10 MPH TODAY...WEST
TO NORTHWEST AT 5 TO 10 MPH TONIGHT...AND NORTHWEST AT 10 TO 15
MPH WITH GUSTS TO 25 MPH SUNDAY AFTERNOON.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED DURING THE NEXT FIVE
DAYS.
SHOWERS OVERNIGHT HAVE BROUGHT MOST AREAS A QUARTER TO HALF AN
INCH WITH MORE RAIN SHOWERS EXPECTED LATER TODAY INTO TONIGHT WITH
ANOTHER TENTH TO THIRD OF AN INCH EXPECTED. ANY PRECIPITATION WILL
END BY SUNDAY AFTERNOON FOLLOWED BY DRY WEATHER THROUGH MONDAY
NIGHT. THE NEXT CHANCE OF PCPN WILL COME DURING THE MID WEEK PERIOD.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...KL/11/WASULA
SHORT TERM...11
LONG TERM...KL
AVIATION...KL/WASULA
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
859 PM EDT SUN APR 27 2014
.UPDATE...LOOKING LESS AND LESS LIKELY WE ARE GOING TO SEE MUCH
SEA BREEZE ACTIVITY EVEN WITH THE COLLISION ACROSS THE SPINE...BUT
WILL LEAVE A 10-20 POP IN FOR NEXT FEW HOURS ACROSS INTERIOR
COUNTIES (LOWERING FROM 30-40 PERCENT)...AS THE HRRR STILL TRIES TO
GENERATE A FEW SHRA. OTHERWISE...WILL JUST SEE QUITE A BIT OF
CIRRUS STREAM ACROSS THE REGION OVERNIGHT WITH LITTLE SIGNIFICANT
WEATHER FOR CEN FL. REMAINDER OF FORECAST ON TRACK AND NO
ADDITIONAL CHANGES PLANNED.
&&
.AVIATION...NO SIGNIFICANT AVIATION ISSUES ANTICIPATED. PROBABILITY
OF MVFR VSBY AROUND SUNRISE FOR LAL AND PGD IS NOT HIGH ENOUGH TO
INCLUDE IN TAFS. PROBABILITY OF SHRA LATE MON AFTERNOON (MAINLY
INLAND LAL AREA) ALSO TO LOW TO INCLUDE IN TAFS. THEREFORE...SHOWING
VFR CONDITIONS THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 321 PM EDT SUN APR 27 2014/
..THUNDERSTORMS POSSIBLE THIS AFTERNOON ACROSS PORTIONS OF
CENTRAL FLORIDA...
SHORT TERM (TODAY THROUGH TONIGHT)...
WEST COAST SEA BREEZE CONTINUES TO MARCH INLAND THIS
AFTERNOON...ALREADY REACHING THE INTERSTATE 75 CORRIDOR ACROSS
MUCH OF WEST CENTRAL AND SOUTHWEST FLORIDA. THE EAST COAST SEA
BREEZE CONTINUES ITS MARCH INLAND NEAR THE TURNPIKE
CORRIDOR...NEARING PORTIONS OF METRO ORLANDO TO THE NORTH AND
EASTERN LAKE OKEECHOBEE TO THE SOUTH. VISIBLE SATELLITE IMAGERY
ALSO SHOWS A LAKE SHADOW...WITH THE BREAK IN CLOUDS OVER PORTIONS
OF GLADES...HIGHLANDS...AND OKEECHOBEE COUNTIES.
EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON AND
EVENING AS THESE BOUNDARIES COLLIDE...MAINLY FROM SUMTER/LAKE
COUNTIES DOWN INTO POLK COUNTY. A POTENTIAL EXISTS FOR SOME
ISOLATED STRONG THUNDERSTORMS THAT COULD PRODUCE HAIL AND STRONG
WINDS.
ACTIVITY THAT DEVELOPS ON THE NORTHERN PARTS OF THE BOUNDARY WILL
SPREAD SOUTH THIS EVENING BEFORE DIMINISHING AFTER SUNSET. REMNANT
CLOUDS OVERNIGHT WILL HELP TO KEEP MUCH OF THE AREA IN THE 60S.
MOS GUIDANCE TEMPERATURE SPREAD WAS MINIMAL...PREFERRED A BLEND.
FOR POPS...PREFERRED LOCAL HIGH RESOLUTION MODELING INSTEAD OF THE
MOS GUIDANCE.
MID TERM (MONDAY THROUGH TUESDAY)...
VERY LITTLE CHANGE IN FORECAST PHILOSOPHY WITH THIS ISSUANCE.
02/GARCIA
/ISSUED AT 547 AM EDT SUN APR 27 2014/
RIDGING WILL BE IN PLACE ACROSS FLORIDA BOTH AT THE SURFACE AND
ALOFT ON MONDAY. THE SURFACE RIDGE WILL BE CENTERED WELL TO THE
EAST OF THE STATE WITH PREDOMINANT SOUTHEASTERLY FLOW ACROSS THE
REGION. A SEA BREEZE WILL DEVELOP BY LATE MORNING AND MOVE
STEADILY INLAND DURING THE AFTERNOON. LOW-LEVEL MOISTURE WILL BE
MEAGER...BUT PERHAPS ENOUGH FOR A FEW SHOWERS INLAND. IT WILL BE
QUITE WARM AND RELATIVELY HUMID WITH TEMPERATURES TOPPING 90
DEGREES FOR MUCH OF THE REGION EAST OF I-75.
BY TUESDAY...A LARGE UPPER-LEVEL TROUGH WILL BE APPROACHING FROM
THE NORTHWEST. THE MID-LEVEL RIDGE WILL BE DISPLACED SOUTH AND
EAST...BUT THE SURFACE RIDGE WILL CONTINUE FROM THE ATLANTIC
WESTWARD ACROSS THE STATE. THE IMPACT FROM THE APPROACHING TROUGH
WILL LIKELY REMAIN TO OUR NORTHWEST ON TUESDAY...BUT WE COULD ONCE
AGAIN SEE A FEW SHOWERS OVER THE INTERIOR WITH COLLIDING SEA
BREEZES. TEMPERATURES WILL AGAIN TOP 90 DEGREES EAST OF I-75.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
/ISSUED AT 547 AM EDT SUN APR 27 2014/
MODELS CONTINUE TO SHOW A BROAD UPPER-LEVEL TROUGH OF LOW
PRESSURE SETTING UP ACROSS THE EASTERN TWO THIRDS OF THE U.S.
THROUGH SUNDAY. MODELS ARE SURPRISINGLY SIMILAR WITH FEATURES IN
THE UPPER-LEVELS...BUT DIFFER CONSIDERABLY WITH AN ASSOCIATED WEAK
SURFACE FRONTAL BOUNDARY AND ITS EVENTUAL IMPACTS ON THE REGION.
THE MOST LIKELY SCENARIO IS THAT CLOUDS WILL INCREASE AHEAD OF THE
SYSTEM ON WEDNESDAY WITH RAIN CHANCES INCREASING FROM NORTH TO
SOUTH WEDNESDAY NIGHT AND THURSDAY. THE SURFACE BOUNDARY WILL
LIKELY STALL OVER FLORIDA FOR A TIME BETWEEN THURSDAY AND
SATURDAY... THEN MAY BE FINALLY PUSHED SOUTH OF THE REGION FOR
SUNDAY. THE ECMWF IS THE SLOWEST WITH THE BOUNDARY AND EVEN THAT
MODEL NOW PUSHES MOST OF THE MOISTURE ALONG WITH THE FRONTAL
BOUNDARY TO OUR SOUTH FOR SUNDAY. WITH THE CYCLONIC FLOW ALOFT AND
A MEANDERING FRONTAL BOUNDARY NEARBY...IT SEEMS PRUDENT TO KEEP AT
LEAST SOME MENTION OF RAIN IN THE FORECAST BEGINNING THURSDAY AND
CONTINUING THROUGH AT LEAST SATURDAY.
AVIATION...
VFR EXPECTED THROUGH THE PERIOD...WITH A SEA BREEZE PUSHING
INLAND THIS AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP INLAND OF MOST TERMINALS...LAL COULD SEE THUNDERSTORMS IN
THE COMING HOURS. SEA BREEZE WILL RETREAT AFTER SUNSET WITH LIGHT
EASTERLY FLOW RETURNING OVERNIGHT.
MARINE...
CONDITIONS ARE EXPECTED TO REMAIN PLEASANT FOR BOATING AS HIGH
PRESSURE RIDGES WEST OVER FLORIDA. BUOY REPORTS CONTINUE TO SHOW A
SOUTHEAST WIND IN THE 10 TO 15 KNOT RANGE OUT TO 60 NM...WHILE WINDS
CLOSER TO THE COASTLINE HAVE VEERED TO A SOUTHWEST ONSHORE FLOW WITH
THE AFTERNOON SEA BREEZE. SEAS WILL REMAIN LESS THAN 2 FEET THROUGH
MONDAY. WINDS WILL SLIGHTLY DECREASE OVERNIGHT...BUT WILL THEN AGAIN
INCREASE ON MONDAY AND TUESDAY TO THE 10 TO 15 KNOT RANGE WITH SEAS
IN THE 1 TO 3 FOOT RANGE.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS EXPECTED THROUGH MID-WEEK.
OVERNIGHT/MORNING FOG POTENTIAL MINIMIZED COMPARED TO PREVIOUS
NIGHTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 71 88 72 89 / 0 10 10 0
FMY 71 91 70 91 / 10 20 10 10
GIF 70 91 70 91 / 20 40 10 20
SRQ 69 85 71 87 / 0 10 0 0
BKV 63 90 67 90 / 10 20 10 10
SPG 73 87 73 87 / 0 10 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...88/GITTINGER
AVIATION...88/GITTINGER
AREA FORECAST DISCUSSION
NWS MIAMI FL
116 PM EDT SAT APR 26 2014
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST AS HIGH PRESSURE
REMAINS THE DOMINANT WEATHER FEATURE. SEA BREEZES WILL BE THE
DOMINANT WEATHER MAKER ALONG BOTH COASTS EACH AFTERNOON. THERE
COULD BE ONE OR TWO SHOWERS LATE THIS AFTERNOON AS THE BOUNDARIES
CONVERGE OVER THE INTERIOR BUT TOO FAR INLAND FROM THE TERMINALS
TO PLACE IN THE TAFS.
KOB
&&
.PREV DISCUSSION... /ISSUED 947 AM EDT SAT APR 26 2014/
UPDATE...
THE CURRENT FORECAST IS ON TRACK. A DRY AND WARM DAY WITH PLENTY
OF SUNSHINE IS EXPECTED FOR TODAY. A LARGE AREA OF HIGH PRESSURE
IS LOCATED OVER THE GULF OF MEXICO WITH VERY DRY AIR IN PLACE
BETWEEN 700 AND 500 MB. LIGHT NORTHERLY WINDS WILL PREVAIL TODAY
AND WILL TURN EASTERLY BY SUNDAY MORNING. THIS WILL BRING A
LITTLE BIT OF MORE MOISTURE, BUT IT WILL STAY CONFINED TO THE
BOUNDARY LAYER. STRONG SUBSIDENCE BELOW 700 MB WILL DELAY ANY
SHOWERS THAT MAY FORM OVER LAND UNTIL LATE IN THE DAY. THE MID
LEVEL TEMPERATURES ARE STILL RELATIVELY COOL, AROUND -10C, WHICH
WILL ALLOW FOR THE FORMATION OF ONE OR TWO LATE AFTERNOON SHOWERS.
HOWEVER, IF ANY THING FORMS IT WILL BE VERY SPARSE IN COVERAGE, AND
IN THE AREAS WHERE THE EAST COAST AND WEST COAST SEA BREEZES
COLLIDE. OVER THE ATLANTIC WATERS WE CAN BEGIN TO OBSERVE THE SET
UP OF A CONVERGENCE LINE BETWEEN EASTERLY FLOW SOUTH OF THE PALM
BEACH WATERS AND MORE NORTHERLY FLOW TO THE NORTH. THIS COULD
TRIGGER A FEW SHOWERS OVER THE PALM BEACH WATERS. COVERAGE WILL
BE SPARSE.
PREV DISCUSSION... /ISSUED 715 AM EDT SAT APR 26 2014/
AVIATION...
DEEP LAYER HIGH PRESSURE WILL DOMINATE SOUTH FLORIDA THROUGH THE
FORECAST WITH SEA BREEZES DEVELOPING ALONG BOTH COASTS. SOME OF
THE HIGH RESOLUTION SHORT TERM MODELS ARE AGAIN SHOWING A FEW
SHOWERS ALONG THE SEA BREEZES OVER THE INTERIOR LATE IN THE
AFTERNOON. LEFT OUT OF THE FORECAST FOR NOW AS THESE WILL TOO FEW
TO CONSIDER AND MORE THAN LIKELY WELL INLAND AWAY FROM ANY
TERMINALS.
KOB
PREV DISCUSSION... /ISSUED 420 AM EDT SAT APR 26 2014/
DISCUSSION...
WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE
TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF
NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN
GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS
PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED
OVER SOUTH FLORIDA.
AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE
WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL
BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES
COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF
COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE
KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA.
FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A
LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED.
LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE
BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON.
TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST
TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA
EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF
HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO
THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS
ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE
AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN
COLLIER COUNTY.
SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH
EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES
ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION
IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR
STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL
CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL
LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL
PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH
EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH
FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK.
MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE.
A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO-
THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL
BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA.
A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY
WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER
NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO
THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH
THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE.
DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY
TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD.
SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC
WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE
NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN
THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE
FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK.
AVIATION...
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF
PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP
MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE
IN THE LATE EVENING HOURS.
MARINE...
A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH
LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW
RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE
EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A
GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
947 AM EDT SAT APR 26 2014
.UPDATE...
THE CURRENT FORECAST IS ON TRACK. A DRY AND WARM DAY WITH PLENTY
OF SUNSHINE IS EXPECTED FOR TODAY. A LARGE AREA OF HIGH PRESSURE
IS LOCATED OVER THE GULF OF MEXICO WITH VERY DRY AIR IN PLACE
BETWEEN 700 AND 500 MB. LIGHT NORTHERLY WINDS WILL PREVAIL TODAY
AND WILL TURN EASTERLY BY SUNDAY MORNING. THIS WILL BRING A
LITTLE BIT OF MORE MOISTURE, BUT IT WILL STAY CONFINED TO THE
BOUNDARY LAYER. STRONG SUBSIDENCE BELOW 700 MB WILL DELAY ANY
SHOWERS THAT MAY FORM OVER LAND UNTIL LATE IN THE DAY. THE MID
LEVEL TEMPERATURES ARE STILL RELATIVELY COOL, AROUND -10C, WHICH
WILL ALLOW FOR THE FORMATION OF ONE OR TWO LATE AFTERNOON SHOWERS.
HOWEVER, IF ANY THING FORMS IT WILL BE VERY SPARSE IN COVERAGE, AND
IN THE AREAS WHERE THE EAST COAST AND WEST COAST SEA BREEZES
COLLIDE. OVER THE ATLANTIC WATERS WE CAN BEGIN TO OBSERVE THE SET
UP OF A CONVERGENCE LINE BETWEEN EASTERLY FLOW SOUTH OF THE PALM
BEACH WATERS AND MORE NORTHERLY FLOW TO THE NORTH. THIS COULD
TRIGGER A FEW SHOWERS OVER THE PALM BEACH WATERS. COVERAGE WILL
BE SPARSE.
&&
.PREV DISCUSSION... /ISSUED 715 AM EDT SAT APR 26 2014/
AVIATION...
DEEP LAYER HIGH PRESSURE WILL DOMINATE SOUTH FLORIDA THROUGH THE
FORECAST WITH SEA BREEZES DEVELOPING ALONG BOTH COASTS. SOME OF
THE HIGH RESOLUTION SHORT TERM MODELS ARE AGAIN SHOWING A FEW
SHOWERS ALONG THE SEA BREEZES OVER THE INTERIOR LATE IN THE
AFTERNOON. LEFT OUT OF THE FORECAST FOR NOW AS THESE WILL TOO FEW
TO CONSIDER AND MORE THAN LIKELY WELL INLAND AWAY FROM ANY
TERMINALS.
KOB
PREV DISCUSSION... /ISSUED 420 AM EDT SAT APR 26 2014/
DISCUSSION...
WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE
TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF
NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN
GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS
PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED
OVER SOUTH FLORIDA.
AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE
WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL
BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES
COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF
COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE
KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA.
FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A
LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED.
LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE
BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON.
TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST
TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA
EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF
HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO
THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS
ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE
AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN
COLLIER COUNTY.
SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH
EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES
ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION
IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR
STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL
CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL
LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL
PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH
EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH
FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK.
MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE.
A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO-
THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL
BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA.
A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY
WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER
NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO
THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH
THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE.
DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY
TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD.
SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC
WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE
NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN
THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE
FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK.
AVIATION...
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF
PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP
MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE
IN THE LATE EVENING HOURS.
MARINE...
A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH
LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW
RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE
EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A
GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 72 85 72 / 0 0 10 0
FORT LAUDERDALE 87 77 86 75 / 0 0 10 0
MIAMI 88 75 87 74 / 0 0 0 0
NAPLES 86 70 87 70 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...71/JE
LONG TERM....71/JE
AREA FORECAST DISCUSSION
NWS MIAMI FL
715 AM EDT SAT APR 26 2014
.AVIATION...
DEEP LAYER HIGH PRESSURE WILL DOMINATE SOUTH FLORIDA THROUGH THE
FORECAST WITH SEA BREEZES DEVELOPING ALONG BOTH COASTS. SOME OF
THE HIGH RESOLUTION SHORT TERM MODELS ARE AGAIN SHOWING A FEW
SHOWERS ALONG THE SEA BREEZES OVER THE INTERIOR LATE IN THE
AFTERNOON. LEFT OUT OF THE FORECAST FOR NOW AS THESE WILL TOO FEW
TO CONSIDER AND MORE THAN LIKELY WELL INLAND AWAY FROM ANY
TERMINALS.
KOB
&&
.PREV DISCUSSION... /ISSUED 420 AM EDT SAT APR 26 2014/
DISCUSSION...
WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE
TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF
NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN
GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS
PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED
OVER SOUTH FLORIDA.
AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE
WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL
BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES
COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF
COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE
KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA.
FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A
LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED.
LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE
BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON.
TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST
TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA
EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF
HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO
THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS
ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE
AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN
COLLIER COUNTY.
SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH
EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES
ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION
IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR
STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL
CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL
LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL
PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH
EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH
FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK.
MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE.
A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO-
THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL
BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA.
A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY
WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER
NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO
THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH
THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE.
DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY
TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD.
SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC
WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE
NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN
THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE
FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK.
AVIATION...
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF
PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP
MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE
IN THE LATE EVENING HOURS.
MARINE...
A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH
LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW
RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE
EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A
GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 72 85 72 / 0 0 10 0
FORT LAUDERDALE 87 77 86 75 / 0 0 10 0
MIAMI 88 75 87 74 / 0 0 0 0
NAPLES 86 70 87 70 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
420 AM EDT SAT APR 26 2014
.DISCUSSION...
WATER VAPOR AND RUC ANALYSIS THIS MORNING SHOWED A SHORTWAVE
TROUGH FROM THE GREAT LAKES SOUTHEAST TO OFF THE EAST COAST OF
NORTH CAROLINA. AN UPPER LEVEL RIDGE STRETCHED FROM THE WESTERN
GULF OF MEXICO INTO CANADA...AND ANOTHER SHORTWAVE TROUGH WAS
PUSHING INTO CENTRAL CALIFORNIA. A NEARLY ZONAL FLOW WAS NOTED
OVER SOUTH FLORIDA.
AT THE SURFACE...AN AREA OF LOW PRESSURE WAS LOCATED OVER THE
WESTERN ATLANTIC JUST SOUTH OF NEW JERSEY...AND A WEAK FRONTAL
BOUNDARY WAS DRAPED SOUTH AND WEST ALONG THE SOUTHEAST STATES
COASTS AND INTO SOUTHERN GEORGIA AND ALONG THE NORTHERN GULF
COAST. WEAK SURFACE HIGH PRESSURE REMAINED ACROSS FLORIDA AND THE
KEYS...WITH A LIGHT NORTHERLY LOW LEVEL FLOW OVER SOUTH FLORIDA.
FOR TODAY...DRIER AIR WILL MOVE IN FROM THE WEST...WITH PWATS A
LITTLE OVER AN INCH. SO DRY AND WARM CONDITIONS ARE EXPECTED.
LIGHT WINDS WILL CONTINUE THIS MORNING...WITH SEA BREEZE
BOUNDARIES PUSHING INLAND ALONG BOTH COASTS THIS AFTERNOON.
TONIGHT...THE UPPER LEVEL RIDGE OVER THE WESTERN GULF IS FORECAST
TO PUSH TOWARDS THE EASTERN GULF AS THE SHORTWAVE OVER CALIFORNIA
EJECTS EAST INTO THE INTERMOUNTAIN WEST. THE SURFACE RIDGE OF
HIGH PRESSURE OVER THE REGION WILL BEGIN TO SHIFT TO THE EAST INTO
THE WESTERN ATLANTIC...WITH EASTERLY FLOW DEVELOPING. LIGHT WINDS
ARE FORECAST ACROSS THE INTERIOR...AND PATCHY FOG MAY DEVELOP ONCE
AGAIN. AREAS OF SMOKE ARE LIKELY NEAR THE WILDFIRE ACROSS EASTERN
COLLIER COUNTY.
SUNDAY THROUGH TUESDAY...THE SURFACE RIDGE WILL CONTINUE TO PUSH
EAST...AND THE EASTERLY FLOW WILL INCREASE. SEA BREEZE BOUNDARIES
ARE FORECAST TO INTERACT ACROSS THE INTERIOR NEAR THE LAKE REGION
IN THE AFTERNOON. THIS MAY BE ENOUGH TO SPARK A FEW SHOWERS OR
STORMS IN THIS REGION ON SUNDAY. ABOVE NORMAL TEMPERATURES WILL
CONTINUE WITH HIGHS IN THE MID 80S TO LOWER 90S. AN UPPER LEVEL
LOW WILL CUTOFF ACROSS THE INTERMOUNTAIN WEST AND THE CENTRAL
PLAINS SUNDAY...AND THEN MEANDER ACROSS THE CENTRAL PLAINS THROUGH
EARLY NEXT WEEK. THE UPPER LEVEL RIDGE WILL MOVE OVER SOUTH
FLORIDA ON SUNDAY AND THEN REMAIN THROUGH THE MIDDLE OF THE WEEK.
MAINLY DRY AND VERY WARM CONDITIONS WILL CONTINUE.
A LARGE UPPER TROUGH/LOW WILL ENVELOP ABOUT THE EASTERN TWO-
THIRDS OF THE CONUS WEDNESDAY AND THURSDAY. UPPER HEIGHTS WILL
BEGIN TO LOWER...BUT SOME RIDGING WILL REMAIN OVER SOUTH FLORIDA.
A COLD FRONT IS FORECAST TO PUSH INTO NORTHERN FLORIDA BY
WEDNESDAY EVENING. HOWEVER...THE FRONT IS FORECAST TO REMAIN OVER
NORTH OR CENTRAL FLORIDA THROUGH FRIDAY. THE FLOW WILL SHIFT TO
THE SOUTHEAST. MOISTURE IS FORECAST TO SLOWLY INCREASE THROUGH
THE END OF THE WEEK...AND RAIN CHANCES ARE FORECAST TO INCREASE.
DEWPOINTS ARE FORECAST TO INCREASE BACK TO AROUND 70 BY
TUESDAY...AND REMAIN AROUND 70 THROUGH THE END OF THE PERIOD.
SOUTHEAST WINDS ARE FORECAST TO BE 10-15 KNOTS OVER THE ATLANTIC
WATERS AS WELL...AND THIS WILL KEEP LOW TEMPERATURES WELL ABOVE
NORMAL FOR THE EAST COAST. OVERNIGHT LOWS ARE FORECAST TO BE IN
THE MID/UPPER 70S FOR THE EAST COAST METRO AREAS. HIGHS ARE
FORECAST TO BE IN THE MID 80S TO LOW 90S THROUGH THE WEEK.
&&
.AVIATION...
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER THROUGH THE TAF
PERIOD. THIS WILL KEEP VFR CONDITIONS IN PLACE. WINDS WILL PICK UP
MID DAY AS THE SEA BREEZE DEVELOPS, THEN RETURN TO LIGHT AND VARIABLE
IN THE LATE EVENING HOURS.
&&
.MARINE...
A WEAK PRESSURE GRADIENT PREVAILS ACROSS THE REGIONAL WATERS WITH
LIGHT AND SOMEWHAT VARIABLE WINDS TODAY WITH MORE EASTERLY FLOW
RETURNING ON SUNDAY INTO EARLY NEXT WEEK. IN GENERAL SEAS ARE
EXPECTED TO BE 2 FEET OR LESS THROUGH THE WEEKEND WITH JUST A
GRADUAL INCREASE IN WINDS AND SEAS EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 72 85 72 / 0 0 10 0
FORT LAUDERDALE 87 77 86 75 / 0 0 10 0
MIAMI 88 75 87 74 / 0 0 0 0
NAPLES 86 70 87 70 / 0 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE...84/AK
AVIATION...13/SI
AREA FORECAST DISCUSSION...CORRECTED
NWS BOISE ID
858 PM MDT SUN APR 27 2014
.DISCUSSION...MINOR UPDATE TO INCLUDE ISOLATED THUNDERSTORMS FROM
THE TREASURE AND MAGIC VALLEYS SOUTH TO THE NV BORDER UNTIL
MIDNIGHT. SEVERAL STRIKES OCCURRED NW OF ADRIAN OREGON FROM 815
TO 830 PM WITH CELLS NEAR THE BASE OF A NEGATIVE TILT UPPER LEVEL
TROUGH. LATEST HRRR RUNS DEVELOP THE AREA OF STRONGER RADAR
RETURNS WEST OF BOISE THROUGH THE TREASURE VALLEY THEN SOUTHEAST
THROUGH MIDNIGHT. WITH WEST FLOW ALOFT AND RADAR TRENDS THIS LOOKS
REASONABLE. LATE NIGHT CLEARING WITH PATCHY FREEZING TEMPERATURES
IN THE AG VALLEYS IS STILL ON TRACK FOR LATE TONIGHT AND EARLY
MONDAY...WITH COLD LOWS PERSISTING MONDAY MORNING AS WELL.
&&
.AVIATION...ISOLATED TO SCATTERED MVFR/LOCAL IFR SNOW SHOWERS WILL
CONTINUE OVER THE MOUNTAINS THROUGH MONDAY. SNOW LEVELS MAINLY ABOVE
4K FT MSL. ISOLATED THUNDERSTORMS MAINLY IN THE SNAKE RIVER VALLEY
AND SOUTHWEST HIGHLANDS WILL END BY 06Z. OTHERWISE EXPECT VFR
CONDITIONS. SURFACE WINDS...LIGHT EXCEPT INCREASING TO 15-25 KTS E
AND S OF KMUO AFTER 15Z. WINDS ALOFT... NORTHWEST UP TO 30 KTS AT
10K FT MSL.
&&
.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH TUESDAY...UPPER LEVEL WAVE WITH
ASSOCIATED SURFACE COLD FRONT IS MOVING THROUGH THE REGION AT THIS
TIME. SHOWERS AND THUNDERSTORMS ARE SPREAD OVER THE CWA AND ARE
MOVING EAST TO SOUTHEAST AT ABOUT 40 MPH. THIS CONVECTION WILL
CONTINUE THROUGH THE AFTERNOON AND THEN DECREASE INTO THE EARLY
EVENING HOURS AS IT MOVES EAST. SO FAR SMALL HAIL...OR MORE
PROPERLY GRAUPEL...HAS BEEN REPORTED WITH SOME OF THE STRONGER
CELLS. TONIGHT...SKIES WILL BEGIN TO CLEAR FROM THE WEST AND
TEMPS WILL DROP DOWN AROUND 10 DEGREES BELOW NORMAL. SHOWERS WILL
LINGER IN THE WEST-CENTRAL MOUNTAINS TOMORROW...BUT BY TOMORROW
EVENING THE CHANCE OF PRECIP WILL DROP TO NEAR ZERO. A WARM UP
WILL BEGIN TOMORROW AS DRY CONDITIONS TAKE HOLD UNDER A BUILDING
UPPER LEVEL RIDGE. HOWEVER...WE WILL STILL BE 5 TO 10 DEGREES
BELOW NORMAL. THE WARM UP REALLY KICKS IN TUESDAY...WITH HIGHS
BACK UP TO NEAR OR JUST A FEW DEGREES ABOVE NORMAL.
LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...UPPER LEVEL RIDGE WILL
BUILD OVER THE WEST COAST THROUGH FRIDAY BRINGING WARMER AND DRIER
CONDITIONS. THE RIDGE AXIS REMAINS OVER THE CASCADE MOUNTAINS
REACHING IT/S PEAK AMPLITUDE ON THURSDAY. THE WARMEST AIR NEVER
QUITE GETS INTO THE REGION BUT TEMPERATURES WILL BE ABOUT 10 DEGREES
ABOVE NORMAL THURSDAY. UPPER RIDGE WEAKENS SIGNIFICANTLY FRIDAY AS
SHORTWAVES ASSOCIATED WITH STRENGTHENING UPPER LEVEL LOW OVER THE
HUDSON BAY PUSH SOUTHWARD FROM BRITISH COLUMBIA. BY SATURDAY THE
RIDGE FLATTENS WITH THE UPPER FLOW BECOMING NORTHWEST FOR A SLIGHT
CHANCE OF PRECIPITATION IN THE WEST CENTRAL MOUNTAINS THROUGH
SUNDAY. TEMPERATURES FALL CLOSE TO NORMAL ON SUNDAY.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...VM
AVIATION.....JT
PREV SHORT TERM...SP
PREV LONG TERM....JS/WH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
930 PM CDT SUN APR 27 2014
.DISCUSSION...
304 PM CDT
RELATIVELY QUIET DAY ACROSS NORTHERN IL/NORTHWEST IN...WITH VISIBLE
IMAGERY INDICATING JUST SOME HIGH BASED CLOUDS. UNFORTUNATELY WITH A
STRONG SFC RIDGE PARKED NORTHEAST OVER HUDSON BAY...AND A
STRENGTHENING LOW PRESSURE OVER THE CENTRAL PLAINS...THIS HAS SETUP
A TIGHT GRADIENT OVER THE NORTHERN HALF OF THE CWFA AND A STIFF EAST
WIND. AS A RESULT AREAS ADJACENT TO THE LAKESHORE IN ILLINOIS HAVE
NOT HAD TEMPS WARM BEYOND THE MID/UPR 40S. ELSEWHERE TEMPS HAVE BEEN
ABLE TO WARM WELL INTO THE 50S AND LOW 60S. SFC ANALYSIS INDICATED
ONE BOUNDARY BEGINNING TO LIFT NORTH INTO THE SOUTHERN CWFA...WHERE
TEMPS HAVE BEEN ABLE TO QUICKLY WARM INTO THE MID/UPR 70S WHILE DEW
POINTS WERE STILL HOLDING IN THE LOW/MID 40S. THIS WAS THE LEADING
EDGE OF COOLING CLOUD TOPS...AND A FEW ISOLATED SHRA/TSRA. THE MOIST
BOUNDARY REMAINED FURTHER SOUTH AND APPEARS TO BE MORE SLUGGISH AT
LIFTING NORTH UNTIL LATER THIS EVENING.
THE MAIN CONVECTIVE FEATURES HAVE MAINLY BEEN POSITIONED OVER
WESTERN IOWA STRETCHING SOUTH THROUGH MISSOURI...WHICH IS THE
LOCATION OF THE STRONGER CONVERGENCE AND BEST INSTABILITY. GUIDANCE
FOR THIS EVENING HAS BEEN RELATIVELY CONSISTENT...WITH HOLDING
PRECIP/CONVECTION OUT OF THE BULK OF THE CWFA OR MAINLY WEST OF A
ROCKFORD TO KANKAKEE LINE UNTIL AFT 00Z. MID-LVL INSTABILITY DOES
CREEP UP AND WITH THE WEAK BOUNDARY CURRENTLY LIFTING NORTH...THE
POSSIBILITY OF AN ISOLATED SHRA/TSRA PRIOR TO 00Z IN THE WESTERN
CWFA DOES LOOK POSSIBLE.
PWAT VALUES WILL STEADILY INCREASE THIS EVENING...NEARING 1.5" AND A
FEW GUIDANCE MEMBERS SUGGEST A FEW LOCATIONS NEARING 1.8" SHORTLY
AFT MIDNIGHT. IT DOES APPEAR THAT THE BOUNDARY STALLS FROM LIFTING
FURTHER NORTH THAN THE I-88 CORRIDOR OVER NORTHERN IL. LLVL
NOCTURNAL JET CRANKS UP OVERNIGHT WITH 850MB SOUTHERLY WINDS NEARING
50KTS. IT APPEARS THE MOST PROBABLE TIMING FOR CONVECTION
OVERSPREADING THE CWFA WILL BE AFT 03Z. WITH THE AFOREMENTIONED
CONDITIONS...IT APPEARS THE GREATEST CONCERN OVERNIGHT WILL BE THE
POTENTIAL FOR THUNDERSTORMS PRODUCING PERIODS OF HEAVY RAINFALL.
THIS MATCHES UP WELL WITH THE THINKING OUT OF THE STORM PREDICTION
CENTER...WHICH HAS THE SLIGHT RISK OUTLINED JUST SOUTH/SOUTHWEST OF
THE FORECAST AREA TONIGHT.
OVERNIGHT LOWS WILL BE A CHALLENGE. AT THIS TIME HAVE OPTED TO HOLD
ONTO THE EXPECTED COOLING OVERNIGHT...ALTHOUGH COULD SEE TEMPS
ACTUALLY HOLDING MUCH WARMER IN THE SOUTHERN CWFA. IT WILL HINGE ON
THE ARRIVAL OF THE BOUNDARIES LIFTING NORTH.
MONDAY THROUGH MONDAY NIGHT...
ONGOING CONVECTION DURING THE PRE-DAWN HOURS SHOULD BE SLOWLY
LIFTING NORTH ACROSS THE FORECAST AREA...WITH A POSSIBLE LULL IN
ACTIVITY CLOSER TO 16-20Z. THEN THE QUESTION REMAINS WHEN WILL THE
ATMOSPHERE RECOVER. CURRENT INDICATIONS ARE THAT THE ATMOSPHERE WILL
BE ABLE TO RECOVER BY 20Z...WHICH BECOMES A BIT OF A CONCERN FOR
STRONG TO POSSIBLY SEVERE STORMS TO DEVELOP. THE SFC LOW WILL BE
SLOWLY SLIDING EAST...WITH THE 500MB VORT MAXIMA WILL BE ROUNDING
THE TROUGH AXIS AND PLACE THE CWFA NEAR THE LEFT-EXIT REGION. WITH
HEIGHTS EXPECTED TO BE LOWERING...AND VERY WARM/MOIST AIR OVERHEAD
AND GOOD CONVERGENCE...EXPECT THINGS TO BLOSSOM RATHER QUICKLY BY
THE AFTN MON. WITH STRONG LIFT THROUGH THIS REGION...LARGE HAIL DOES
LOOK POSSIBLE FROM SOME OF THE STRONGER/SEVERE STORMS. WITH A
LINGERING BOUNDARY OVER THE CWFA...FOCUSED HELICITY MAY ALLOW A FEW
STRONGER STORMS TO PRODUCE AN ISOLATED TORNADO. BASED ON THESE
CONDITIONS THE SPC HAS OUR CWFA SOUTH OF I-88 OUTLOOKED FOR A SLIGHT
RISK OF SEVERE WEATHER MON.
A DRY WEDGE DOES TRY TO WORK INTO THE REGION LATE MON NGT...WHICH
COULD ALLOW FOR SLIGHTLY LOWER POPS. STILL HAVE LIKELY CONDS THRU
MONDAY NIGHT.
TEMPS MON SOUTH OF THE BOUNDARY COULD WARM WELL INTO THE 70S AND
POSSIBLY SEVERAL AREAS SOUTH OF LASALLE TO KANKAKEE REACHING THE LOW
80S. FURTHER NORTH CLOSER TO THE BOUNDARY TEMPS WILL BE MUCH COOLER
IN THE LOW/MID 50S. NORTHEAST IL AREAS ADJACENT TO LAKE MICHIGAN
WILL SEE TEMPS HOLD IN THE MID/UPR 40S WITH A STRONG EAST FLOW OFF
OF LAKE MICHIGAN.
TUESDAY THROUGH THURSDAY...
ONCE THE SFC LOW WRAPS UP OVER THE REGION...IT BUMPS UP AGAINST A
ROBUST SFC RIDGE PARKED OVER HUDSON BAY. THIS WILL PREVENT THE LOW
FROM DEPARTING THE REGION...AND MAINTAIN PERIODS OF PRECIP THROUGH
TUE/WED/THUR. FORTUNATELY THE CONVECTIVE POTENTIAL COMES TO AN END
TUE NGT. TEMPS WILL STEADILY COOL WITH THE WARMEST DAY IN THIS
STRETCH BEING TUE WHEN HIGHS SHUD BE ABLE TO REACH THE 60S. THEN
WED/THUR WITH CONSIDERABLE SOLAR SHIELDING...TEMPS WILL STRUGGLE TO
WARM BEYOND THE 50S.
FRIDAY THROUGH SUNDAY...
TOWARDS THE END OF THE SFC RIDGE OVER HUDSON BAY BEGINS TO SLIDE
EAST AND WEAKEN...WHICH WILL ALLOW THE QUASI-STATIONARY LOW TO
FINALLY DEPART THE REGION. THIS MAY BRING SOME DRY AIR TO THE REGION
BY SAT NGT. UNFORTUNATELY GUIDANCE IS THEN SUGGESTING A TROUGH TO
DEVELOP ACROSS THE CENTRAL PLAINS AND SLIDE SOUTHEAST TOWARDS THE
PLAINS AND WESTERN GREAT LAKES BY THE SECOND HALF OF THE WEEKEND.
BEACHLER
&&
.HYDROLOGY...
A MOISTURE-RICH ATMOSPHERE...ESPECIALLY FOR LATE APRIL...WILL
PRESENT HEAVY RAIN LIKELIHOOD TONIGHT AND POSSIBLY EXTENDING INTO
MONDAY MORNING. RAIN COVERAGE SHOULD BE HIGHEST BY LATE EVENING
INTO OVERNIGHT...WITH EMBEDDED STORMS PRESENTING THE HIGHEST
LIKELIHOOD FOR THESE PERIODS HEAVY RAIN. OUR FORECAST CALLS FOR
ONE TO TWO INCHES OF RAIN IN MOST AREAS TONIGHT INTO MONDAY
MORNING. WHILE THIS IS EXPECTED TO BE MORE OF A RAIN SITUATION
THAN SCATTERED SHOWERS...WHEN DEALING WITH EMBEDDED
STORMS...RAINFALL AMOUNTS ARE LIKELY TO VARY QUITE A BIT AND
HEAVIER MAGNITUDE COULD OCCUR UNDER MORE PERSISTENT AREAS OF
STORMS. SOMEWHAT DRY ANTECEDENT CONDITIONS PRECLUDE ANY TYPE OF
FLASH FLOOD WATCH ISSUANCE. FLASH FLOOD GUIDANCE FROM THE RIVER
FORECAST CENTER CALLS FOR TWO INCHES OR MORE PER SIX HOURS NEEDED
IN MOST LOCATIONS TO WARRANT A HEIGHTENED THREAT. WILL STILL NEED
TO MONITOR CLOSELY...ESPECIALLY CONSIDERING MONDAY AFTERNOON AND
EVENING ARE LIKELY TO PRESENT STORMS...SOME OF WHICH WILL AGAIN BE
CAPABLE OF HEAVY RAIN. THE COMBINED EFFECTS THROUGH THE NEXT 48
HOURS COULD CAUSE SOME RIVERS TO RISE TO NEAR FLOOD STAGE BASED
ON PREDICTIONS USING A SUITE OF COMPUTER MODELS.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* ADDITIONAL ROUNDS OF SHRA AND PROBABLY EMBEDDED TSRA OVERNIGHT
AND MONDAY MORNING. TRIED TO TIME THE MOST LIKELY WINDOWS IN THE
TAF BUT TIMING MAY WELL CHANGE.
* STEADY EASTERLY WINDS GUSTING TO AROUND 25 KT AT TIMES
TONIGHT/MONDAY...30 KT GUSTS POSSIBLE.
* CIGS LOWERING TO MVFR THEN IFR TONIGHT/MONDAY MORNING...MAY NEED
TO SLOW ARRIVAL TIMING.
* ORGANIZED SHRA/TSRA POSSIBLE LATE AFTERNOON/EARLY EVENING MONDAY.
MDB
//DISCUSSION...UPDATED 03Z...
RAIN BEGINNING TO WIND DOWN FOR A BIT ACROSS THE TERMINALS.
EASTERLY WINDS ARE STARTING TO SPORADICALLY GUST TO AROUND 25
KT AND AM THINKING GUSTS WILL BECOME MORE FREQUENT INTO THE
OVERNIGHT...WITH SUSTAINED SPEEDS IN THE 15 TO 20 KT RANGE. RADAR
MOSAIC SHOWS THE NEXT BAND OF SHOWERS AND SOME EMBEDDED THUNDER
WORKING NORTHEAST ACROSS WEST CENTRAL AND SOUTHWEST ILLINOIS. THIS
LOOKS TO ARRIVE IN THE 07-09Z TIME FRAME SO HAVE ADJUSTED TIMING TO
BETTER FIT THIS THINKING. KEPT VCTS MENTION BUT BASED ON LATEST
TRENDS THIS MAY BE A BIT OVERDONE. EVOLUTION OF RAIN/THUNDER
THROUGH MID MORNING IS STILL UP FOR DEBATE SO WILL MAKE LITTLE
CHANGE TO EARLIER THINKING. DID FURTHER SLOW THE LOWERING OF CIGS
TO IFR.
MDB
FROM 00Z...
THUNDERSTORM FORECAST REMAINS A CHALLENGE THIS EVENING. THUNDER
THAT POPPED NEAR THE CHI TERMINALS LAST 1-2 HOURS HAS FADED FOR
THE MOST PART WITH JUST ABOUT ALL LIGHT RAIN UPSTREAM TO THE
SOUTH. MORE ORGANIZED CONVECTION ACROSS NORTHWEST IL IS TRACKING
NORTHEAST AND FADING BUT DO EXPECT SOME THUNDER TO CROSS THE RFD
AREA AND POINTS NORTHWEST OF ORD PRIOR TO 02 OR 03Z. OTHERWISE
SHRA WILL PERSIST THROUGH THE EVENING. SHRA/TSRA OVER CENTRAL
MISSOURI APPEARS TO BE THE NEXT ORGANIZED ACTIVITY TO AFFECT THE
AREA EARLY TONIGHT. THERE THEN APPEARS TO BE A GAP IN COVERAGE TO
SOME DEGREE LATER TONIGHT BEFORE ANOTHER ROUND OF SHRA/TSRA
AFFECTS THE AREA MONDAY MORNING IN CONJUNCTION WITH AN UPPER
TROUGH MOVING FROM NW ARKANSAS. CIGS WILL LIKELY LOWER WITH TIME
TONIGHT BUT HAVE SLOWED THE ARRIVAL OF IFR BY SEVERAL HOURS AND
MAY STILL BE TOO FAST WITH THE LOWERING OVERALL. WINDS HAVE ABATED
FOR NOW BUT SHOULD COME BACK UP AND REMAIN STEADY FROM THE EAST.
SHOULD SPEEDS NOT COME UP AS MUCH AS EXPECTED THEN LOW LEVEL WIND
SHEAR MAY BECOME DEVELOP AS SPEEDS INCREASE TO AROUND 50 KT BY
2000 FT AGL.
THERE MAY BE A BREAK IN OVERALL ACTIVITY FOR A TIME FROM MIDDAY
THROUGH EARLY OR MID AFTERNOON MONDAY BUT A WARM FRONT WILL BE
STRENGTHENING SOUTH OF THE TERMINALS THROUGH THE DAY AND GRADUALLY
LIFTING NORTHWARD. THIS IS EXPECTED TO TRIGGER SHRA/TSRA BY MID OR
LATE AFTERNOON THAT WILL LIFT NORTH INTO THE EVENING. HAVE FAIRLY
GOOD CONFIDENCE IN THIS SCENARIO SO HAVE ADDED A SEVERAL HOUR
WINDOW OF TSRA TO THE TAFS LATER MONDAY AFTERNOON. TIMING MAY NEED
TO BE SHIFTED HOWEVER. OVERALL THERE IS A RISK FOR SHRA/TSRA AT
JUST ABOUT ANY TIME THROUGH TOMORROW EVENING BUT TRIED TO IDENTIFY
THE MOST LIKELY PERIODS IN THE TAF.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM CONFIDENCE IN ADDITIONAL BANDS OF SHRA AND EMBEDDED TSRA
AFFECTING THE TERMINALS OVERNIGHT/MONDAY MORNING.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN CIGS LOWERING LATER TONIGHT...LOW-
MEDIUM CONFIDENCE IN TIMING.
* MEDIUM-HIGH CONFIDENCE IN SHRA/TSRA OCCURRING LATER
MONDAY...MEDIUM CONFIDENCE IN TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...CHANCE RAIN AND THUNDER...MVFR LIKELY WITH IFR POSSIBLE.
WEDNESDAY - SATURDAY...CHANCE RAIN...MVFR LIKELY WITH IFR POSSIBLE.
MDB
&&
.MARINE...
243 PM CDT
THE PRIMARY FEATURE THAT WILL BE DOMINATING CONDITIONS OVER THE LAKE
FOR THE NEXT FEW DAYS WILL BE A LARGE LOW PRESSURE SYSTEM MOVING
THROUGH THE PLAINS AND HEADING SLOWLY TOWARD THE WESTERN GREAT
LAKES. THE WARM FRONT EXTENDING EAST FROM THIS LOW IS STAYING SOUTH
OF THE LAKE SO FAR...BUT IS SUPPORTING A TIGHT PRESSURE GRADIENT AND
STRONG EASTERLY WINDS OVER THE LAKE. MEASURED GUSTS AT LAND BASED
POINTS AROUND THE LAKE THIS AFTERNOON ARE IN THE NEIGHBORHOOD OF 25
KTS BUT WILL BE INCREASING THROUGH THE EVENING...EVENTUALLY TO
GALES. THIS FITS WITH THE WIND OBSERVATIONS IN THE UPPER TEENS WE
ARE SEEING SO FAR FROM SHIPS ON THE LAKE...THOUGH THERE ARE MANY
MORE SHIPS OUT THERE THAN SHIP OBSERVATIONS TODAY...SO SOME VESSELS
MAY BE SEEING DIFFERENT VALUES. THE WARM FRONT FINALLY REACHES THE
SOUTHERN LAKE MONDAY NIGHT. THIS WILL RELAX THE GRADIENT
SOMEWHAT...ESPECIALLY ACROSS THE SOUTH HALF...SO THIS IS WHEN WE
HAVE THE GALE WARNING CURRENTLY SET TO EXPIRE. THERE IS A CHANCE
THAT THE WARNING OVER THE NORTH HALF MAY NEED TO BE EXTENDED INTO
THE DAYTIME HOURS TUESDAY.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 10 PM MONDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 AM MONDAY TO 10 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
859 PM CDT Sun Apr 27 2014
.DISCUSSION...
ISSUED 859 PM CDT Sun Apr 27 2014
First round of convection has lifted into northern Illinois and
diminished early this evening, while a second round is currently
developing upstream across Missouri. Mesoscale analysis shows a
relatively stable airmass in place across central Illinois into
eastern Missouri, with highest MUCAPE values focused further south
across the Ozarks. As a result, numerous thunderstorms are merging
into an MCS across southeast Missouri into northern Arkansas,
while only scattered weaker activity is noted further north into
central/northern Missouri. It appears the severe MCS will track
E/NE across far southern Illinois and western Kentucky over the
next few hours. Meanwhile, a relative lull in the precip will be
noted across central Illinois. 50kt LLJ developing from the lower
Mississippi River Valley northward into Illinois is expected to
create increasing showers/thunder as the night progresses. Have
made some adjustments to POPs for the rest of the night, mainly to
lower rain chances this evening, but will still go with
categorical overnight.
Barnes
&&
.AVIATION...
ISSUED 645 PM CDT Sun Apr 27 2014
Scattered showers and thunderstorms will affect the central IL
airports this evening, especially the I-74 taf sites with MVFR
vsbys and ceilings possible. Visibility dropped below 2 miles at
CMI with heavy rain but this will be brief. HRRR shows a
widespread band of showers and thunderstorms lifting ne across
central IL and brought in MVFR ceilings and visibilities again.
Could be lull in convection Monday morning with more redevelopment
in unstable air mass during Monday afternoon with MVFR conditions
returning. ENE winds have diminish for a time early this morning
to 10-15 kts and gusts 15-25 kts to veer se and increase to 15-20
kts with gusts to around 25 kts overnight and then turn SSE on
Monday. Strong low pressure of 984 mb over north central KS to
lift ne to NE/IA border by Monday afternoon while lifting warm
front from sw IL through central IL during overnight and into
northern IL Monday.
07
&&
.PREV DISCUSSION...
ISSUED 302 PM CDT Sun Apr 27 2014
Models in good agreement with the overall pattern and surface
features. Differences are in the small mesoscale features and
environmental changes due to the storms moving through the area
currently. Concerns this package will be storm system moving into
the area late this afternoon and through this evening. Then
another round of severe weather is possible tomorrow afternoon
through tomorrow evening. Models continue to look similar with mid
and long range models showing the upper level low sitting over the
area and spinning for rest of the week. This means unsettled
weather for the middle and latter part of the work week.
SHORT TERM...Tonight through Wednesday
Line of strong to severe storms is moving across northern MO and
will reach into western IL in a couple of hours. SPC has issued a
severe watch til 9pm to cover this line of storms. Large hail and
damaging winds look to be the primary threat, though an isolated
tornado is not out of the question. Occasional thunderstorms will
continue late this afternoon and into tonight. Once the line of
storms moves through, there will likely be a break in the pcpn
over some of the area. However, with the warm front becoming
active, pcpn could continue on and off through the night. So will
continue high pops over the area. CWA will be well entrenched in
the warm sector tomorrow and the break in the pcpn will likely
continue during the early morning hours. However, things will
become active during the late morning hours again as the dry line
moves toward the area. Severe weather is again likely from late
morning through the afternoon with the dry line. Will be plenty of
instability and sufficient shear for some storm to rotate. Plus,
the cutoff 500mb low is a cold core. So, good lapse rates to
support hail. SVR threat looks to be hail and wind, along with
tornadoes closer to the lower pressure area that will be northwest
of the cwa during the afternoon. Thunderstorms will be possible
again Tuesday as the low pressure area pulls east and northeast of
the area. Then Tue night and Wed, with the upper level low still
rotating around northern IL, diurnal showers will remain possible
through mid week.
Temps will remain warm, but then cool off on Wed after the upper
level system gets closer to the area with cooler air.
LONG TERM...Wednesday night through Sunday
The upper level system will remain near the area through the rest
of the week. This will continue to bring diurnal showers to the
region through Saturday. Then am expecting a change in the pattern
for the rest of the weekend, though another system is forecast to
bring pcpn on Sunday. Temps will remain on the cool side through
the period as upper level troughiness continues through the rest
of the week and into the weekend. A more zonal flow looks possible
by end of the weekend.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
719 PM CDT SUN APR 27 2014
.DISCUSSION...
304 PM CDT
RELATIVELY QUIET DAY ACROSS NORTHERN IL/NORTHWEST IN...WITH VISIBLE
IMAGERY INDICATING JUST SOME HIGH BASED CLOUDS. UNFORTUNATELY WITH A
STRONG SFC RIDGE PARKED NORTHEAST OVER HUDSON BAY...AND A
STRENGTHENING LOW PRESSURE OVER THE CENTRAL PLAINS...THIS HAS SETUP
A TIGHT GRADIENT OVER THE NORTHERN HALF OF THE CWFA AND A STIFF EAST
WIND. AS A RESULT AREAS ADJACENT TO THE LAKESHORE IN ILLINOIS HAVE
NOT HAD TEMPS WARM BEYOND THE MID/UPR 40S. ELSEWHERE TEMPS HAVE BEEN
ABLE TO WARM WELL INTO THE 50S AND LOW 60S. SFC ANALYSIS INDICATED
ONE BOUNDARY BEGINNING TO LIFT NORTH INTO THE SOUTHERN CWFA...WHERE
TEMPS HAVE BEEN ABLE TO QUICKLY WARM INTO THE MID/UPR 70S WHILE DEW
POINTS WERE STILL HOLDING IN THE LOW/MID 40S. THIS WAS THE LEADING
EDGE OF COOLING CLOUD TOPS...AND A FEW ISOLATED SHRA/TSRA. THE MOIST
BOUNDARY REMAINED FURTHER SOUTH AND APPEARS TO BE MORE SLUGGISH AT
LIFTING NORTH UNTIL LATER THIS EVENING.
THE MAIN CONVECTIVE FEATURES HAVE MAINLY BEEN POSITIONED OVER
WESTERN IOWA STRETCHING SOUTH THROUGH MISSOURI...WHICH IS THE
LOCATION OF THE STRONGER CONVERGENCE AND BEST INSTABILITY. GUIDANCE
FOR THIS EVENING HAS BEEN RELATIVELY CONSISTENT...WITH HOLDING
PRECIP/CONVECTION OUT OF THE BULK OF THE CWFA OR MAINLY WEST OF A
ROCKFORD TO KANKAKEE LINE UNTIL AFT 00Z. MID-LVL INSTABILITY DOES
CREEP UP AND WITH THE WEAK BOUNDARY CURRENTLY LIFTING NORTH...THE
POSSIBILITY OF AN ISOLATED SHRA/TSRA PRIOR TO 00Z IN THE WESTERN
CWFA DOES LOOK POSSIBLE.
PWAT VALUES WILL STEADILY INCREASE THIS EVENING...NEARING 1.5" AND A
FEW GUIDANCE MEMBERS SUGGEST A FEW LOCATIONS NEARING 1.8" SHORTLY
AFT MIDNIGHT. IT DOES APPEAR THAT THE BOUNDARY STALLS FROM LIFTING
FURTHER NORTH THAN THE I-88 CORRIDOR OVER NORTHERN IL. LLVL
NOCTURNAL JET CRANKS UP OVERNIGHT WITH 850MB SOUTHERLY WINDS NEARING
50KTS. IT APPEARS THE MOST PROBABLE TIMING FOR CONVECTION
OVERSPREADING THE CWFA WILL BE AFT 03Z. WITH THE AFOREMENTIONED
CONDITIONS...IT APPEARS THE GREATEST CONCERN OVERNIGHT WILL BE THE
POTENTIAL FOR THUNDERSTORMS PRODUCING PERIODS OF HEAVY RAINFALL.
THIS MATCHES UP WELL WITH THE THINKING OUT OF THE STORM PREDICTION
CENTER...WHICH HAS THE SLIGHT RISK OUTLINED JUST SOUTH/SOUTHWEST OF
THE FORECAST AREA TONIGHT.
OVERNIGHT LOWS WILL BE A CHALLENGE. AT THIS TIME HAVE OPTED TO HOLD
ONTO THE EXPECTED COOLING OVERNIGHT...ALTHOUGH COULD SEE TEMPS
ACTUALLY HOLDING MUCH WARMER IN THE SOUTHERN CWFA. IT WILL HINGE ON
THE ARRIVAL OF THE BOUNDARIES LIFTING NORTH.
MONDAY THROUGH MONDAY NIGHT...
ONGOING CONVECTION DURING THE PRE-DAWN HOURS SHOULD BE SLOWLY
LIFTING NORTH ACROSS THE FORECAST AREA...WITH A POSSIBLE LULL IN
ACTIVITY CLOSER TO 16-20Z. THEN THE QUESTION REMAINS WHEN WILL THE
ATMOSPHERE RECOVER. CURRENT INDICATIONS ARE THAT THE ATMOSPHERE WILL
BE ABLE TO RECOVER BY 20Z...WHICH BECOMES A BIT OF A CONCERN FOR
STRONG TO POSSIBLY SEVERE STORMS TO DEVELOP. THE SFC LOW WILL BE
SLOWLY SLIDING EAST...WITH THE 500MB VORT MAXIMA WILL BE ROUNDING
THE TROUGH AXIS AND PLACE THE CWFA NEAR THE LEFT-EXIT REGION. WITH
HEIGHTS EXPECTED TO BE LOWERING...AND VERY WARM/MOIST AIR OVERHEAD
AND GOOD CONVERGENCE...EXPECT THINGS TO BLOSSOM RATHER QUICKLY BY
THE AFTN MON. WITH STRONG LIFT THROUGH THIS REGION...LARGE HAIL DOES
LOOK POSSIBLE FROM SOME OF THE STRONGER/SEVERE STORMS. WITH A
LINGERING BOUNDARY OVER THE CWFA...FOCUSED HELICITY MAY ALLOW A FEW
STRONGER STORMS TO PRODUCE AN ISOLATED TORNADO. BASED ON THESE
CONDITIONS THE SPC HAS OUR CWFA SOUTH OF I-88 OUTLOOKED FOR A SLIGHT
RISK OF SEVERE WEATHER MON.
A DRY WEDGE DOES TRY TO WORK INTO THE REGION LATE MON NGT...WHICH
COULD ALLOW FOR SLIGHTLY LOWER POPS. STILL HAVE LIKELY CONDS THRU
MONDAY NIGHT.
TEMPS MON SOUTH OF THE BOUNDARY COULD WARM WELL INTO THE 70S AND
POSSIBLY SEVERAL AREAS SOUTH OF LASALLE TO KANKAKEE REACHING THE LOW
80S. FURTHER NORTH CLOSER TO THE BOUNDARY TEMPS WILL BE MUCH COOLER
IN THE LOW/MID 50S. NORTHEAST IL AREAS ADJACENT TO LAKE MICHIGAN
WILL SEE TEMPS HOLD IN THE MID/UPR 40S WITH A STRONG EAST FLOW OFF
OF LAKE MICHIGAN.
TUESDAY THROUGH THURSDAY...
ONCE THE SFC LOW WRAPS UP OVER THE REGION...IT BUMPS UP AGAINST A
ROBUST SFC RIDGE PARKED OVER HUDSON BAY. THIS WILL PREVENT THE LOW
FROM DEPARTING THE REGION...AND MAINTAIN PERIODS OF PRECIP THROUGH
TUE/WED/THUR. FORTUNATELY THE CONVECTIVE POTENTIAL COMES TO AN END
TUE NGT. TEMPS WILL STEADILY COOL WITH THE WARMEST DAY IN THIS
STRETCH BEING TUE WHEN HIGHS SHUD BE ABLE TO REACH THE 60S. THEN
WED/THUR WITH CONSIDERABLE SOLAR SHIELDING...TEMPS WILL STRUGGLE TO
WARM BEYOND THE 50S.
FRIDAY THROUGH SUNDAY...
TOWARDS THE END OF THE SFC RIDGE OVER HUDSON BAY BEGINS TO SLIDE
EAST AND WEAKEN...WHICH WILL ALLOW THE QUASI-STATIONARY LOW TO
FINALLY DEPART THE REGION. THIS MAY BRING SOME DRY AIR TO THE REGION
BY SAT NGT. UNFORTUNATELY GUIDANCE IS THEN SUGGESTING A TROUGH TO
DEVELOP ACROSS THE CENTRAL PLAINS AND SLIDE SOUTHEAST TOWARDS THE
PLAINS AND WESTERN GREAT LAKES BY THE SECOND HALF OF THE WEEKEND.
BEACHLER
&&
.HYDROLOGY...
A MOISTURE-RICH ATMOSPHERE...ESPECIALLY FOR LATE APRIL...WILL
PRESENT HEAVY RAIN LIKELIHOOD TONIGHT AND POSSIBLY EXTENDING INTO
MONDAY MORNING. RAIN COVERAGE SHOULD BE HIGHEST BY LATE EVENING
INTO OVERNIGHT...WITH EMBEDDED STORMS PRESENTING THE HIGHEST
LIKELIHOOD FOR THESE PERIODS HEAVY RAIN. OUR FORECAST CALLS FOR
ONE TO TWO INCHES OF RAIN IN MOST AREAS TONIGHT INTO MONDAY
MORNING. WHILE THIS IS EXPECTED TO BE MORE OF A RAIN SITUATION
THAN SCATTERED SHOWERS...WHEN DEALING WITH EMBEDDED
STORMS...RAINFALL AMOUNTS ARE LIKELY TO VARY QUITE A BIT AND
HEAVIER MAGNITUDE COULD OCCUR UNDER MORE PERSISTENT AREAS OF
STORMS. SOMEWHAT DRY ANTECEDENT CONDITIONS PRECLUDE ANY TYPE OF
FLASH FLOOD WATCH ISSUANCE. FLASH FLOOD GUIDANCE FROM THE RIVER
FORECAST CENTER CALLS FOR TWO INCHES OR MORE PER SIX HOURS NEEDED
IN MOST LOCATIONS TO WARRANT A HEIGHTENED THREAT. WILL STILL NEED
TO MONITOR CLOSELY...ESPECIALLY CONSIDERING MONDAY AFTERNOON AND
EVENING ARE LIKELY TO PRESENT STORMS...SOME OF WHICH WILL AGAIN BE
CAPABLE OF HEAVY RAIN. THE COMBINED EFFECTS THROUGH THE NEXT 48
HOURS COULD CAUSE SOME RIVERS TO RISE TO NEAR FLOOD STAGE BASED
ON PREDICTIONS USING A SUITE OF COMPUTER MODELS.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* -SHRA THROUGH THE EVENING WITH ISOLATED TS PRIOR TO 01Z.
* ADDITIONAL ROUNDS OF SHRA AND PROBABLY EMBEDDED TSRA OVERNIGHT
AND MONDAY MORNING. TRIED TO TIME THE MOST LIKELY WINDOWS IN THE
TAF BUT TIMING MAY WELL CHANGE.
* STEADY EASTERLY WINDS GUSTING TO AROUND 25 KT AT TIMES TONIGHT/MONDAY.
* CIGS LOWERING TO MVFR THEN IFR TONIGHT/MONDAY MORNING...MAY NEED
TO SLOW ARRIVAL TIMING.
* ORGANIZED SHRA/TSRA POSSIBLE LATE AFTERNOON/EARLY EVENING MONDAY.
MDB
//DISCUSSION...UPDATED 00Z...
THUNDERSTORM FORECAST REMAINS A CHALLENGE THIS EVENING. THUNDER
THAT POPPED NEAR THE CHI TERMINALS LAST 1-2 HOURS HAS FADED FOR
THE MOST PART WITH JUST ABOUT ALL LIGHT RAIN UPSTREAM TO THE
SOUTH. MORE ORGANIZED CONVECTION ACROSS NORTHWEST IL IS TRACKING
NORTHEAST AND FADING BUT DO EXPECT SOME THUNDER TO CROSS THE RFD
AREA AND POINTS NORTHWEST OF ORD PRIOR TO 02 OR 03Z. OTHERWISE
SHRA WILL PERSIST THROUGH THE EVENING. SHRA/TSRA OVER CENTRAL
MISSOURI APPEARS TO BE THE NEXT ORGANIZED ACTIVITY TO AFFECT THE
AREA EARLY TONIGHT. THERE THEN APPEARS TO BE A GAP IN COVERAGE TO
SOME DEGREE LATER TONIGHT BEFORE ANOTHER ROUND OF SHRA/TSRA
AFFECTS THE AREA MONDAY MORNING IN CONJUNCTION WITH AN UPPER
TROUGH MOVING FROM NW ARKANSAS. CIGS WILL LIKELY LOWER WITH TIME
TONIGHT BUT HAVE SLOWED THE ARRIVAL OF IFR BY SEVERAL HOURS AND
MAY STILL BE TOO FAST WITH THE LOWERING OVERALL. WINDS HAVE ABATED
FOR NOW BUT SHOULD COME BACK UP AND REMAIN STEADY FROM THE EAST.
SHOULD SPEEDS NOT COME UP AS MUCH AS EXPECTED THEN LOW LEVEL WIND
SHEAR MAY BECOME DEVELOP AS SPEEDS INCREASE TO AROUND 50 KT BY
2000 FT AGL.
THERE MAY BE A BREAK IN OVERALL ACTIVITY FOR A TIME FROM MIDDAY
THROUGH EARLY OR MID AFTERNOON MONDAY BUT A WARM FRONT WILL BE
STRENGTHENING SOUTH OF THE TERMINALS THROUGH THE DAY AND GRADUALLY
LIFTING NORTHWARD. THIS IS EXPECTED TO TRIGGER SHRA/TSRA BY MID OR
LATE AFTERNOON THAT WILL LIFT NORTH INTO THE EVENING. HAVE FAIRLY
GOOD CONFIDENCE IN THIS SCENARIO SO HAVE ADDED A SEVERAL HOUR
WINDOW OF TSRA TO THE TAFS LATER MONDAY AFTERNOON. TIMING MAY NEED
TO BE SHIFTED HOWEVER. OVERALL THERE IS A RISK FOR SHRA/TSRA AT
JUST ABOUT ANY TIME THROUGH TOMORROW EVENING BUT TRIED TO IDENTIFY
THE MOST LIKELY PERIODS IN THE TAF.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH CONFIDENCE THAT MAINLY -SHRA WILL AFFECT THE
TERMINALS THROUGH THE EVENING WITH TS WANING NEXT HOUR OR SO.
COULD STILL SEE A ROGUE STORM POP UP HOWEVER.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN CIGS LOWERING LATER TONIGHT...LOW-
MEDIUM CONFIDENCE IN TIMING.
* MEDIUM-HIGH CONFIDENCE IN SHRA/TSRA OCCURRING LATER
MONDAY...MEDIUM CONFIDENCE IN TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...CHANCE RAIN AND THUNDER...MVFR LIKELY WITH IFR POSSIBLE.
WEDNESDAY - SATURDAY...CHANCE RAIN...MVFR LIKELY WITH IFR POSSIBLE.
MDB
&&
.MARINE...
243 PM CDT
THE PRIMARY FEATURE THAT WILL BE DOMINATING CONDITIONS OVER THE LAKE
FOR THE NEXT FEW DAYS WILL BE A LARGE LOW PRESSURE SYSTEM MOVING
THROUGH THE PLAINS AND HEADING SLOWLY TOWARD THE WESTERN GREAT
LAKES. THE WARM FRONT EXTENDING EAST FROM THIS LOW IS STAYING SOUTH
OF THE LAKE SO FAR...BUT IS SUPPORTING A TIGHT PRESSURE GRADIENT AND
STRONG EASTERLY WINDS OVER THE LAKE. MEASURED GUSTS AT LAND BASED
POINTS AROUND THE LAKE THIS AFTERNOON ARE IN THE NEIGHBORHOOD OF 25
KTS BUT WILL BE INCREASING THROUGH THE EVENING...EVENTUALLY TO
GALES. THIS FITS WITH THE WIND OBSERVATIONS IN THE UPPER TEENS WE
ARE SEEING SO FAR FROM SHIPS ON THE LAKE...THOUGH THERE ARE MANY
MORE SHIPS OUT THERE THAN SHIP OBSERVATIONS TODAY...SO SOME VESSELS
MAY BE SEEING DIFFERENT VALUES. THE WARM FRONT FINALLY REACHES THE
SOUTHERN LAKE MONDAY NIGHT. THIS WILL RELAX THE GRADIENT
SOMEWHAT...ESPECIALLY ACROSS THE SOUTH HALF...SO THIS IS WHEN WE
HAVE THE GALE WARNING CURRENTLY SET TO EXPIRE. THERE IS A CHANCE
THAT THE WARNING OVER THE NORTH HALF MAY NEED TO BE EXTENDED INTO
THE DAYTIME HOURS TUESDAY.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...10 PM SUNDAY TO 10 PM MONDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 AM MONDAY TO 10 PM MONDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
646 PM CDT Sun Apr 27 2014
.DISCUSSION...
ISSUED 302 PM CDT Sun Apr 27 2014
Models in good agreement with the overall pattern and surface
features. Differences are in the small mesoscale features and
environmental changes due to the storms moving through the area
currently. Concerns this package will be storm system moving into
the area late this afternoon and through this evening. Then
another round of severe weather is possible tomorrow afternoon
through tomorrow evening. Models continue to look similar with mid
and long range models showing the upper level low sitting over the
area and spinning for rest of the week. This means unsettled
weather for the middle and latter part of the work week.
SHORT TERM...Tonight through Wednesday
Line of strong to severe storms is moving across northern MO and
will reach into western IL in a couple of hours. SPC has issued a
severe watch til 9pm to cover this line of storms. Large hail and
damaging winds look to be the primary threat, though an isolated
tornado is not out of the question. Occasional thunderstorms will
continue late this afternoon and into tonight. Once the line of
storms moves through, there will likely be a break in the pcpn
over some of the area. However, with the warm front becoming
active, pcpn could continue on and off through the night. So will
continue high pops over the area. CWA will be well entrenched in
the warm sector tomorrow and the break in the pcpn will likely
continue during the early morning hours. However, things will
become active during the late morning hours again as the dry line
moves toward the area. Severe weather is again likely from late
morning through the afternoon with the dry line. Will be plenty of
instability and sufficient shear for some storm to rotate. Plus,
the cutoff 500mb low is a cold core. So, good lapse rates to
support hail. SVR threat looks to be hail and wind, along with
tornadoes closer to the lower pressure area that will be northwest
of the cwa during the afternoon. Thunderstorms will be possible
again Tuesday as the low pressure area pulls east and northeast of
the area. Then Tue night and Wed, with the upper level low still
rotating around northern IL, diurnal showers will remain possible
through mid week.
Temps will remain warm, but then cool off on Wed after the upper
level system gets closer to the area with cooler air.
LONG TERM...Wednesday night through Sunday
The upper level system will remain near the area through the rest
of the week. This will continue to bring diurnal showers to the
region through Saturday. Then am expecting a change in the pattern
for the rest of the weekend, though another system is forecast to
bring pcpn on Sunday. Temps will remain on the cool side through
the period as upper level troughiness continues through the rest
of the week and into the weekend. A more zonal flow looks possible
by end of the weekend.
&&
.AVIATION...
ISSUED 645 PM CDT Sun Apr 27 2014
Scattered showers and thunderstorms will affect the central IL
airports this evening, especially the I-74 taf sites with MVFR
vsbys and ceilings possible. Visibility dropped below 2 miles at
CMI with heavy rain but this will be brief. HRRR shows a
widespread band of showers and thunderstorms lifting ne across
central IL and brought in MVFR ceilings and visibilities again.
Could be lull in convection Monday morning with more redevelopment
in unstable air mass during Monday afternoon with MVFR conditions
returning. ENE winds have diminish for a time early this morning
to 10-15 kts and gusts 15-25 kts to veer se and increase to 15-20
kts with gusts to around 25 kts overnight and then turn SSE on
Monday. Strong low pressure of 984 mb over north central KS to
lift ne to NE/IA border by Monday afternoon while lifting warm
front from sw IL through central IL during overnight and into
northern IL Monday.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1147 PM CDT FRI APR 25 2014
.SYNOPSIS...
ISSUED AT 238 PM CDT FRI APR 25 2014
BEAUTIFUL DAY TODAY WITH PLENTIFUL SUNSHINE AND TEMPERATURES AS
OF 2 PM ALREADY IN THE UPPER 60S/LOW 70S AREA WIDE. DEWPOINTS HAVE
MANAGED TO STAY IN THE 40S THROUGH MUCH OF THE MORNING AND ARE
ONLY NOW DROPPING INTO THE 30S.
UPPER AIR ANALYSIS THIS MORNING DEPICTED CUTOFF UPPER LOW SPINNING
OVER NORTHEAST MINNESOTA AND LAKE SUPERIOR WITH BROAD RIDGING
TAKING PLACE FROM WESTERN KANSAS INTO ALBERTA CANADA. AT THE
SURFACE...WEAK RIDGING THAT WAS OVER THE CWA HAS NOW PUSHED EAST
INTO INDIANA. A WEAK COLD FRONT WAS SEEN SLOWLY PUSHING SOUTH OVER
MINNESOTA WITH MAINLY MID-HIGH LEVEL CLOUDS SEEN BEHIND THE FRONT.
LATEST WV IMAGERY SHOWS STRONG SYSTEM JUST OFF THE WEST COAST. THIS
SYSTEM WILL BRING UNSETTLED WEATHER TO THE REGION THIS WEEKEND AND
BEYOND.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 238 PM CDT FRI APR 25 2014
FORECAST FOCUS ON SMALL CHANCE OF PCPN THIS EVENING...OTHERWISE
QUIET AND DRY CONDITIONS EXPECTED.
WEAK COLD FRONT OVER MINNESOTA WILL DROP SOUTH ACROSS THE CWA
TONIGHT AND STALL AS IT REACHES THE IOWA-MISSOURI BORDER. HI-RES
MODELS AND THE LATEST RAP TRENDS ALL SHOW LOW LEVEL CONVERGENCE...
OMEGAS...AND MOISTURE IN THE 850-700MB LAYER ALONG AND BEHIND THE
FRONT INCREASING TONIGHT AND SHOULD BE SUFFICIENT ENOUGH TO
PRODUCE VERY LIGHT SHOWERS OR SPRINKLES MAINLY NORTH AND EAST OF A
LINE FROM THE QUAD CITIES TO PRINCETON ILLINOIS. HAVE MAINTAINED SLIGHT
CHANCE POPS IN THIS AREA FOR THIS POSSIBILITY. I AM CONCERNED THAT
THE SURFACE TO 850MB LAYER MAY BE TOO DRY FOR ANY PCPN TO REACH
THE GROUND AND WILL PASS THIS ON TO THE NIGHT SHIFT. WINDS TO
GRADUALLY SHIFT TO THE NORTHEAST AS FRONT TRACKS THROUGH THE CWA.
OVERNIGHT LOW TEMPERATURES WILL DEPEND ON HOW FAST THE FRONT MOVES
THROUGH AND ITS POSITION EARLY SATURDAY. LOWS SHOULD RANGE FROM
THE UPPER 30S/LOW 40S ON THE COOL SIDE OF THE BOUNDARY TO THE
LOWER 50S IN THE FAR SOUTH.
SATURDAY...ANOTHER PLEASANT DAY IN STORE AS UPPER LEVEL RIDGING
MOVES ACROSS THE AREA. A FRONTAL BOUNDARY WILL BE SITUATED ACROSS
THE SOUTHERN PORTIONS OF THE CWA WITH WINDS MAINLY FROM THE EAST
DURING THE DAY. THIS WILL RESULT IN A LARGE TEMPERATURE GRADIENT
SETTING UP ACROSS THE AREA BY THE AFTERNOON. DEEP MIXING TO 900MB
AND PARTLY SUNNY SKIES THROUGH AT LEAST THE EARLY AFTERNOON WILL
ALLOW HIGHS TO REACH THE LOWER 60S IN THE NORTHEAST TO THE UPPER
70S IN THE FAR SOUTH. AN ACTIVE PATTERN BEGINS ACROSS THE MIDWEST
STARTING SATURDAY NIGHT...SEE LONG TERM DISCUSSION FOR MORE DETAILS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 248 PM CDT FRI APR 25 2014
MODELS CONTINUE TO SHOW A HIGHLY AMPLIFIED...BLOCKED...PATTERN
EVOLVING OVER THE CONSUS DURING THE WEEKEND. THIS WILL RESULT IN A
LARGE OCCLUDED SYSTEM BECOMING NEARLY STATIONARY OVER THE UPPER
MIDWEST FOR MUCH OF THE COMING WEEK. THIS PATTERN CONTINUES TO
SUPPORT A PROLONGED RAINFALL EVENT OVER THE MID MISSISSIPPI VALLEY
WITH SIGNIFICANT RAINFALL...RESULTING IN FLOODING ON AREA
TRIBUTARIES AND THE MISSISSIPPI RIVER.
SATURDAY NIGHT SURFACE CYCLOGENESIS WILL TAKE PLACE OVER THE WESTERN
PLAINS...AHEAD OF A DEEP UPPER TROF MOVING THROUGH THE WESTERN U.S.
AS THE SURFACE LOW FORMS A WARM FRONT WILL DEVELOP FROM THE CENTRAL
PLAINS THROUGH NORTHERN MISSOURI. DEEP SOUTHERN FLOW AHEAD OF THE
WESTERN TROF WILL BRING ABUNDANT GULF MOISTURE NORTH ACROSS THE WARM
FRONT. THE LOW LEVEL JET BY LATE SATURDAY EVENING SHOULD BE POINTED
AT EASTERN NE AND WESTERN IA PROVIDING FORCING FOR MCS DEVELOPMENT.
THE MCS SHOULD TRACK EAST OVERNIGHT REACHING EASTERN IA DURING THE
EARLY MORNING HOURS. WHILE THE THREAT OF SEVERE STORMS WITH THIS
MCS WILL BE THE GREATEST OVER WESTERN IA AND EASTERN NE...SOME
ISOLATED SEVERE STORMS COULD REACH PARTS OF EASTERN IOWA AFTER
MIDNIGHT WITH HAIL BEING THE GREATEST THREAT. SUNDAY AND SUNDAY
NIGHT THE SEVERE THREAT WILL INCREASE FOR THE MID MISSISSIPPI VALLEY
AS THE WARM FRONT MOVES INTO NORTHERN MO OR SOUTHERN IA AND CENTRAL
IL AND STRONG MID LEVEL FLOW AHEAD OF THE UPPER LOW MOVES NORTH
THROUGH THE REGION. THE GREATEST THREAT OF SEVERE STORMS SHOULD BE
SUNDAY AFTERNOON AND EVENING ALONG AND SOUTH OF INTERSTATE 80. HAIL
SHOULD BE THE PRIMARY THREAT WITH MODELS SHOWING SOME MID LEVEL
DRYING. HOWEVER NEAR AND SOUTH OF THE WARM FRONT DAMAGING WINDS AND
TORNADIC STORMS CAN/T BE RULED OUT.
HEAVY RAIN POTENTIAL WILL EXIST OVER MUCH OF THE AREA FROM LATE
SATURDAY NIGHT THROUGH SUNDAY NIGHT AND POSSIBLY INTO MONDAY AS THE
SYSTEM MOVES TOWARD THE REGION. THIS MORNINGS WPC 3 DAY TOTAL QPF
ENDING MONDAY MORNING SHOWED A LARGE AREA OF 1 TO 3 INCHES OVER MUCH
OF THE FORECAST AREA...ROUGHLY CENTERED ALONG I80. THIS LOOKS
REASONABLE GIVEN PW/S OF 1 TO 1.5 INCHES OVER THE AREA MUCH OF THE
WEEKEND AND THE SLOW MOVEMENT OF THE OCCLUDED SYSTEM.
AFTER MONDAY MOST MODELS SHOW THE UPPER LOW OVER THE MISSISSIPPI
VALLEY AND MOVING SLOWLY EAST MID TO LATE WEEK. THIS SHOULD KEEP
MORE SHOWERY TYPE PRECIPITATION OVER THE AREA AT LEAST THROUGH
THURSDAY AND POSSIBLY INTO FRIDAY. ISOLATED THUNDERSTORMS WILL BE
POSSIBLE DURING THE AFTERNOON AND EVENING HOURS MONDAY AND TUESDAY
WITH SURFACE DEWPOINTS STILL IN THE 50S AND THE COLD POOL ASSOCIATED
WITH UPPER LOW STILL OVER HEAD. BY MID TO LATE WEEK DRY SURFACE AIR
MOVING IN SHOULD END THE THUNDERSTORM THREAT.
TEMPERATURES SHOULD BE NEAR NORMAL FOR THE WEEKEND THEN TREND BELOW
NORMAL...ESPECIALLY THE HIGHS...FOR MUCH OF THE UPCOMING WEEK WITH
ABUNDANT CLOUDS EXPECTED TO BE OVER THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1141 PM CDT FRI APR 25 2014
VFR CONDITIONS EXPECTED TO PERSIST THROUGH SATURDAY EVENING. WINDS
WILL BECOME EASTERLY AT OR ABOVE 10 KTS WITH OCCASIONAL GUSTS
AROUND 20 KTS POSSIBLE FROM MID AFTERNOON THROUGH EVENING. ELEVATED
WARM ADVECTION MAY RESULT IN SCATTERED SHOWERS DEVELOPING SATURDAY
EVENING...WITH INCREASING CHANCES MAINLY JUST BEYOND END OF THE TAF
CYCLE.
&&
.HYDROLOGY...
ISSUED AT 248 PM CDT FRI APR 25 2014
THREAT OF FLOODING ON AREA TRIBUTARIES AND THE MISSISSIPPI RIVER
WILL INCREASE BY EARLY NEXT WEEK AS A WIDESPREAD SIGNIFICANT
RAINFALL EVENT OCCURS OVER THE REGION. CURRENT FORECASTS SUGGEST A
WIDESPREAD AREA OF 1 TO 4 INCHES OF RAIN ARE POSSIBLE OVER MUCH OF
THE FORECAST AREA BY WEDNESDAY. LOCALLY HEAVY RAINS WILL BE POSSIBLE FROM
LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH SCATTERED SHOWERS
EXPECTED OVER THE AREA EARLY TO MIDWEEK. SINCE THE PRECIPITATION IS
GOING TO OCCUR OVER AN EXTENDED PERIOD OF TIME THE THREAT OF FLASH
FLOODING WILL BE LOW. HOWEVER RIVER FLOODING IS EXPECTED WITH MANY
OF THE AREA TRIBUTARIES AND THE MISSISSIPPI RIVER SEEING AT LEAST
MINOR TO MODERATE FLOODING BY THE MIDDLE OF NEXT WEEK.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GROSS
SHORT TERM...GROSS
LONG TERM...DLF
AVIATION...05
HYDROLOGY...DLF
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1229 PM CDT Sat Apr 26 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 403 AM CDT SAT APR 26 2014
The center of an intense upper level trough was located over
southern CA at 7Z. The upper level trough will lift northeast across
the desert southwest this afternoon, and then lift negative tilt
into southeast CO and across west TX by 12Z SUN.
Early this morning elevated showers were beginning to develop as
isentropic lift was developing ahead of residual 850mb moisture
return. The HRRR along with the ECMWF show the stronger
thunderstorms developing just east of the CWA after 12Z. The 00Z NAM
shows isolated elevated thunderstorms developing along and south of
the KS turnpike by 10Z, then moving east of the CWA during the mid
and late morning hours. Given MUCAPES of 400-1000 J/KG and effective
0-6KM shear of 30 KTS, some of these storms may produce small hail
and the stronger storms may even produce quarter size hail across
portions of east central KS this morning, that is if storms develop
within the CWA.
As an 80kt jet max within the base of the H5 trough lifts northeast
across eastern NM, a lee surface trough across southeast CO,
southward along the NM/TX border will deepen. This will increase the
southerly 850mb winds to 40 KTS across central KS with surface wind
increasing 20 to 30 KTS across most of KS. At this time the
strongest surface winds should remain just southwest and west of the
CWA. The southwest counties of the CWA may come close to wind
advisory criteria during the afternoon hours with sustained winds of
28 MPH and gusts to near 40 MPH.
A surface dryline will develop early this afternoon within the lee
trough axis across extreme southwest KS, then southward across the
TX PNHDL. This dryline will then move northeast into west central KS
and extend southward across extreme western OK by late this
afternoon.
At this time the deepest gulf moisture was located across southern
TX and most models show a quick transport of deep moisture northward
into south central KS by this afternoon. Deeper mixing across
central KS may keep dewpoints in the mid to upper 50s ahead of the
surface dryline.
Both the the 6Z NAM and 00Z Advanced Research WRF show a strong CAP
ahead of the dryline across central KS with no storms developing in
the late afternoon or evening hours. The 12Z ECMWF model shows the
potential for thunderstorms developing along the dryline across
south central KS and north central KS east of HLC. All the models
show temperature and dewpoint temperature depressions greater than
25 degrees along the dryline across central and north central KS.
Therefore, if storms develop they will be high based with MLLCL`s of
5,000 to 6,000 feet. The environment across central KS will have
MLCAPES of 3500 J/KG and Effective shear of 40 KTS. If storms were
able to develop the environment would be favorable for high based
supercell thunderstorms. The higher storm bases will significantly
decrease the potential for tornadoes as these isolated supercell
thunderstorms move northeast off the dryline into the western
counties of the CWA early this evening. In fact they may weaken as
the supercells leave the best area of surface convergence. However,
if any high based supercell manages to develop along the dryline
across north central and central KS, these storms will be capable of
producing large hail and damaging wind gusts.
Highs Today will range from the lower 80s across the northeast
counties to the upper 80s to near 90 across the southwest counties
of the CWA.
I think we will see a break across the CWA from any thunderstorms
from the mid evening hours until 3 or 4 AM Sunday morning, before
severe thunderstorms redevelop. Supercell thunderstorms across
western and central OK will merge into a QLCS or MCS and lift
northeast into south central KS after midnight. Once piece of the
upper level trough will pivot northward across western and central
OK, then into eastern KS through the early morning hours of Sunday.
This will probably maintain any QLCS or MCS cluster of severe
thunderstorms that develop across northern OK and southern KS, as
these storms move northeast ahead of the first H5 trough across the
eastern half of the CWA. The primary hazard with the cluster of
severe thunderstorms will be large hail along with the threat for
damaging winds. I cannot rule out a few supercell thunderstorms on
the southern edge of the severe cluster of thunderstorms. Any
supercells or meso vortices within a QLCS may bring a low chance for
an isolated tornado through early morning hours of Sunday across
portions of east central KS. The MCS/cluster of severe thunderstorms
may also bring heavy rainfall. It will be more of a mesoscale
forecast but areas along and south of the KS turnpike may see the
heaviest rainfall near 12Z SUN.
Overnight lows will only drop into the lower to mid 60s Saturday
night.
.LONG TERM...(Sunday through Friday)
Issued at 403 AM CDT SAT APR 26 2014
The most concentrated and potentially strongest convection still
appears to be on Sunday over the eastern 2/3 of the cwa in the
morning and the eastern 1/3 in the afternoon as the main shortwave
lobe over southwest KS at 12z Sunday lifts northeastward across KS
through the day. Strong to severe convection appears will be
ongoing to start the day Sunday across much of the cwa...gradually
shifting eastward ahead of dry slot in central KS...although
models such as the EC hinting that the cwa could be on the
northern fringe of a substantial MCS just to the south. Models
keep MUCAPE values in the 1500-2000 J/kg range ahead of the
dryline...however 0-6km Bulk Shear values steadily increase into
the 50-60kt range through 18z over the eastern half of the cwa or
near and just ahead of dryline. Although large hail...wind is
possible with the morning convection...any additional development
by midday/afternoon in any increasingly sheared environment would
become more supportive of supercells with all modes of severe
weather possible including a tornado threat. This will be highly
dependent on the speed/timing of the dryline and its proximity to
afternoon heating just of the mid level drying. Although will
leave a slight chance for some lingering convection early evening
in the far eastern counties...it still appears the threat for
severe weather will shift east of the cwa by 00Z as drier air
continues to push eastward across the area as the upper low slows
and occludes over western Nebraska.
Cannot totally rule out a few showers developing over the cwa on
Monday as the upper low wobbles eastward and moisture wraps around
the circulation center and back into the cwa...but will word as
showers for now as instability looks weak. Rain chances will then
linger through Wednesday...then again on Thursday as another
shortwave trough rotates southeast around the upper trough. Rainfall
amounts across the area through mid week should remain light. High
temperatures still expected to cool from the 70s on Sunday to the
60s/near 70 Monday...then the 50s and 60s through the remainder of
the week. Lows will commonly be in the 40s Tuesday through Friday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1223 PM CDT SAT APR 26 2014
VFR prevails as strong southerly winds gust between 30 and 35 kts
through 01Z. Speeds weaken slightly however remain strong above
15 kts sustained through end of TAF period as strong upper
disturbance approaches. Therefore LLWS should not be an issue
as long as winds stay up. Delayed onset of VCTS being in the area
until 09Z at KMHK and 10Z at KTOP/KFOE. High resolution models
develop SCT TS after midnight in southern KS, lifting north and
east towards terminals by Sunday morning. Thunderstorms are
possible through 18Z. Strong warm advection and moistening
boundary layer aft 09Z will lower ceilings to MVFR. IFR or lower
is possible if storms directly impact terminals.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...63
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS TOPEKA KS
653 AM CDT Sat Apr 26 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 403 AM CDT SAT APR 26 2014
The center of an intense upper level trough was located over
southern CA at 7Z. The upper level trough will lift northeast across
the desert southwest this afternoon, and then lift negative tilt
into southeast CO and across west TX by 12Z SUN.
Early this morning elevated showers were beginning to develop as
isentropic lift was developing ahead of residual 850mb moisture
return. The HRRR along with the ECMWF show the stronger
thunderstorms developing just east of the CWA after 12Z. The 00Z NAM
shows isolated elevated thunderstorms developing along and south of
the KS turnpike by 10Z, then moving east of the CWA during the mid
and late morning hours. Given MUCAPES of 400-1000 J/KG and effective
0-6KM shear of 30 KTS, some of these storms may produce small hail
and the stronger storms may even produce quarter size hail across
portions of east central KS this morning, that is if storms develop
within the CWA.
As an 80kt jet max within the base of the H5 trough lifts northeast
across eastern NM, a lee surface trough across southeast CO,
southward along the NM/TX border will deepen. This will increase the
southerly 850mb winds to 40 KTS across central KS with surface wind
increasing 20 to 30 KTS across most of KS. At this time the
strongest surface winds should remain just southwest and west of the
CWA. The southwest counties of the CWA may come close to wind
advisory criteria during the afternoon hours with sustained winds of
28 MPH and gusts to near 40 MPH.
A surface dryline will develop early this afternoon within the lee
trough axis across extreme southwest KS, then southward across the
TX PNHDL. This dryline will then move northeast into west central KS
and extend southward across extreme western OK by late this
afternoon.
At this time the deepest gulf moisture was located across southern
TX and most models show a quick transport of deep moisture northward
into south central KS by this afternoon. Deeper mixing across
central KS may keep dewpoints in the mid to upper 50s ahead of the
surface dryline.
Both the the 6Z NAM and 00Z Advanced Research WRF show a strong CAP
ahead of the dryline across central KS with no storms developing in
the late afternoon or evening hours. The 12Z ECMWF model shows the
potential for thunderstorms developing along the dryline across
south central KS and north central KS east of HLC. All the models
show temperature and dewpoint temperature depressions greater than
25 degrees along the dryline across central and north central KS.
Therefore, if storms develop they will be high based with MLLCL`s of
5,000 to 6,000 feet. The environment across central KS will have
MLCAPES of 3500 J/KG and Effective shear of 40 KTS. If storms were
able to develop the environment would be favorable for high based
supercell thunderstorms. The higher storm bases will significantly
decrease the potential for tornadoes as these isolated supercell
thunderstorms move northeast off the dryline into the western
counties of the CWA early this evening. In fact they may weaken as
the supercells leave the best area of surface convergence. However,
if any high based supercell manages to develop along the dryline
across north central and central KS, these storms will be capable of
producing large hail and damaging wind gusts.
Highs Today will range from the lower 80s across the northeast
counties to the upper 80s to near 90 across the southwest counties
of the CWA.
I think we will see a break across the CWA from any thunderstorms
from the mid evening hours until 3 or 4 AM Sunday morning, before
severe thunderstorms redevelop. Supercell thunderstorms across
western and central OK will merge into a QLCS or MCS and lift
northeast into south central KS after midnight. Once piece of the
upper level trough will pivot northward across western and central
OK, then into eastern KS through the early morning hours of Sunday.
This will probably maintain any QLCS or MCS cluster of severe
thunderstorms that develop across northern OK and southern KS, as
these storms move northeast ahead of the first H5 trough across the
eastern half of the CWA. The primary hazard with the cluster of
severe thunderstorms will be large hail along with the threat for
damaging winds. I cannot rule out a few supercell thunderstorms on
the southern edge of the severe cluster of thunderstorms. Any
supercells or meso vortices within a QLCS may bring a low chance for
an isolated tornado through early morning hours of Sunday across
portions of east central KS. The MCS/cluster of severe thunderstorms
may also bring heavy rainfall. It will be more of a mesoscale
forecast but areas along and south of the KS turnpike may see the
heaviest rainfall near 12Z SUN.
Overnight lows will only drop into the lower to mid 60s Saturday
night.
.LONG TERM...(Sunday through Friday)
Issued at 403 AM CDT SAT APR 26 2014
The most concentrated and potentially strongest convection still
appears to be on Sunday over the eastern 2/3 of the cwa in the
morning and the eastern 1/3 in the afternoon as the main shortwave
lobe over southwest KS at 12z Sunday lifts northeastward across KS
through the day. Strong to severe convection appears will be
ongoing to start the day Sunday across much of the cwa...gradually
shifting eastward ahead of dry slot in central KS...although
models such as the EC hinting that the cwa could be on the
northern fringe of a substantial MCS just to the south. Models
keep MUCAPE values in the 1500-2000 J/kg range ahead of the
dryline...however 0-6km Bulk Shear values steadily increase into
the 50-60kt range through 18z over the eastern half of the cwa or
near and just ahead of dryline. Although large hail...wind is
possible with the morning convection...any additional development
by midday/afternoon in any increasingly sheared environment would
become more supportive of supercells with all modes of severe
weather possible including a tornado threat. This will be highly
dependent on the speed/timing of the dryline and its proximity to
afternoon heating just of the mid level drying. Although will
leave a slight chance for some lingering convection early evening
in the far eastern counties...it still appears the threat for
severe weather will shift east of the cwa by 00Z as drier air
continues to push eastward across the area as the upper low slows
and occludes over western Nebraska.
Cannot totally rule out a few showers developing over the cwa on
Monday as the upper low wobbles eastward and moisture wraps around
the circulation center and back into the cwa...but will word as
showers for now as instability looks weak. Rain chances will then
linger through Wednesday...then again on Thursday as another
shortwave trough rotates southeast around the upper trough. Rainfall
amounts across the area through mid week should remain light. High
temperatures still expected to cool from the 70s on Sunday to the
60s/near 70 Monday...then the 50s and 60s through the remainder of
the week. Lows will commonly be in the 40s Tuesday through Friday.
&&
.AVIATION...(For the 12Z TAFs through 12Z Sunday Morning)
Issued at 648 AM CDT SAT APR 26 2014
Isolated thunderstorms may develop in the vicinity of terminals
KTOP and KFOE through 14Z SAT. Expect VFR conditions through most of
the next 24 hours. Thunderstorms may move into the terminals after
8Z SUN and continue through the morning hours. Any thunderstorm
may bring Brief MVFR ceilings and visibilities through the early
morning hours of Sunday. South-Southeast winds will increase to 14 to 20
KTS with gusts of 22 to 30 KTS. Winds gust may diminish slightly
after 00Z SUN.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...63
AVIATION...Gargan
AREA FORECAST DISCUSSION
NWS TOPEKA KS
423 AM CDT Sat Apr 26 2014
.SHORT TERM...(Today and Tonight)
Issued at 403 AM CDT SAT APR 26 2014
The center of an intense upper level trough was located over
southern CA at 7Z. The upper level trough will lift northeast across
the desert southwest this afternoon, and then lift negative tilt
into southeast CO and across west TX by 12Z SUN.
Early this morning elevated showers were beginning to develop as
isentropic lift was developing ahead of residual 850mb moisture
return. The HRRR along with the ECMWF show the stronger
thunderstorms developing just east of the CWA after 12Z. The 00Z NAM
shows isolated elevated thunderstorms developing along and south of
the KS turnpike by 10Z, then moving east of the CWA during the mid
and late morning hours. Given MUCAPES of 400-1000 J/KG and effective
0-6KM shear of 30 KTS, some of these storms may produce small hail
and the stronger storms may even produce quarter size hail across
portions of east central KS this morning, that is if storms develop
within the CWA.
As an 80kt jet max within the base of the H5 trough lifts northeast
across eastern NM, a lee surface trough across southeast CO,
southward along the NM/TX border will deepen. This will increase the
southerly 850mb winds to 40 KTS across central KS with surface wind
increasing 20 to 30 KTS across most of KS. At this time the
strongest surface winds should remain just southwest and west of the
CWA. The southwest counties of the CWA may come close to wind
advisory criteria during the afternoon hours with sustained winds of
28 MPH and gusts to near 40 MPH.
A surface dryline will develop early this afternoon within the lee
trough axis across extreme southwest KS, then southward across the
TX PNHDL. This dryline will then move northeast into west central KS
and extend southward across extreme western OK by late this
afternoon.
At this time the deepest gulf moisture was located across southern
TX and most models show a quick transport of deep moisture northward
into south central KS by this afternoon. Deeper mixing across
central KS may keep dewpoints in the mid to upper 50s ahead of the
surface dryline.
Both the the 6Z NAM and 00Z Advanced Research WRF show a strong CAP
ahead of the dryline across central KS with no storms developing in
the late afternoon or evening hours. The 12Z ECMWF model shows the
potential for thunderstorms developing along the dryline across
south central KS and north central KS east of HLC. All the models
show temperature and dewpoint temperature depressions greater than
25 degrees along the dryline across central and north central KS.
Therefore, if storms develop they will be high based with MLLCL`s of
5,000 to 6,000 feet. The environment across central KS will have
MLCAPES of 3500 J/KG and Effective shear of 40 KTS. If storms were
able to develop the environment would be favorable for high based
supercell thunderstorms. The higher storm bases will significantly
decrease the potential for tornadoes as these isolated supercell
thunderstorms move northeast off the dryline into the western
counties of the CWA early this evening. In fact they may weaken as
the supercells leave the best area of surface convergence. However,
if any high based supercell manages to develop along the dryline
across north central and central KS, these storms will be capable of
producing large hail and damaging wind gusts.
Highs Today will range from the lower 80s across the northeast
counties to the upper 80s to near 90 across the southwest counties
of the CWA.
I think we will see a break across the CWA from any thunderstorms
from the mid evening hours until 3 or 4 AM Sunday morning, before
severe thunderstorms redevelop. Supercell thunderstorms across
western and central OK will merge into a QLCS or MCS and lift
northeast into south central KS after midnight. Once piece of the
upper level trough will pivot northward across western and central
OK, then into eastern KS through the early morning hours of Sunday.
This will probably maintain any QLCS or MCS cluster of severe
thunderstorms that develop across northern OK and southern KS, as
these storms move northeast ahead of the first H5 trough across the
eastern half of the CWA. The primary hazard with the cluster of
severe thunderstorms will be large hail along with the threat for
damaging winds. I cannot rule out a few supercell thunderstorms on
the southern edge of the severe cluster of thunderstorms. Any
supercells or meso vortices within a QLCS may bring a low chance for
an isolated tornado through early morning hours of Sunday across
portions of east central KS. The MCS/cluster of severe thunderstorms
may also bring heavy rainfall. It will be more of a mesoscale
forecast but areas along and south of the KS turnpike may see the
heaviest rainfall near 12Z SUN.
Overnight lows will only drop into the lower to mid 60s Saturday
night.
.LONG TERM...(Sunday through Friday)
Issued at 403 AM CDT SAT APR 26 2014
The most concentrated and potentially strongest convection still
appears to be on Sunday over the eastern 2/3 of the cwa in the
morning and the eastern 1/3 in the afternoon as the main shortwave
lobe over southwest KS at 12z Sunday lifts northeastward across KS
through the day. Strong to severe convection appears will be
ongoing to start the day Sunday across much of the cwa...gradually
shifting eastward ahead of dry slot in central KS...although
models such as the EC hinting that the cwa could be on the
northern fringe of a substantial MCS just to the south. Models
keep MUCAPE values in the 1500-2000 J/kg range ahead of the
dryline...however 0-6km Bulk Shear values steadily increase into
the 50-60kt range through 18z over the eastern half of the cwa or
near and just ahead of dryline. Although large hail...wind is
possible with the morning convection...any additional development
by midday/afternoon in any increasingly sheared environment would
become more supportive of supercells with all modes of severe
weather possible including a tornado threat. This will be highly
dependent on the speed/timing of the dryline and its proximity to
afternoon heating just of the mid level drying. Although will
leave a slight chance for some lingering convection early evening
in the far eastern counties...it still appears the threat for
severe weather will shift east of the cwa by 00Z as drier air
continues to push eastward across the area as the upper low slows
and occludes over western Nebraska.
Cannot totally rule out a few showers developing over the cwa on
Monday as the upper low wobbles eastward and moisture wraps around
the circulation center and back into the cwa...but will word as
showers for now as instability looks weak. Rain chances will then
linger through Wednesday...then again on Thursday as another
shortwave trough rotates southeast around the upper trough. Rainfall
amounts across the area through mid week should remain light. High
temperatures still expected to cool from the 70s on Sunday to the
60s/near 70 Monday...then the 50s and 60s through the remainder of
the week. Lows will commonly be in the 40s Tuesday through Friday.
&&
.AVIATION...(For the 06Z TAFs through 06Z Saturday Night)
Issued at 1147 PM CDT FRI APR 25 2014
Low level wind shear will be a concern through the 12Z-14Z time
period with surface winds around 10 mph from the south to
southeast and winds around 1500 ft from the southwest near 45 kts.
Still a signal for convection to be in the vicinity of TOP and FOE
from 12Z to 16Z. South winds will increase by 16Z from the south
around 18-20 kts with gusts to 28 kts. The winds will continue to
stay gusty through the end of the period. TSRA may affect MHK
after 02Z but confidence is not high enough to mention.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...63
AVIATION...53
AREA FORECAST DISCUSSION
NWS JACKSON KY
1032 PM EDT SUN APR 27 2014
.UPDATE...
ISSUED AT 1030 PM EDT SUN APR 27 2014
AS EXPECTED...EARLIER THUNDERSTORMS HAVE WEAKENED WITH JUST SOME
WIDELY ISOLATED SHOWERS PUSHING ACROSS THE AREA WITH THE WARM FRONT.
THIS ACTIVITY WILL CONTINUE TO PUSH NORTHWARD OVER THE NEXT 3 TO 5
HOURS...WITH DRIER WEATHER RETURNING THROUGH THE LATTER HALF OF THE
NIGHT. HOWEVER...PLENTY OF SHOWERS AND THUNDERSTORMS UPSTREAM ACROSS
ARKANSAS AND FAR WESTERN KENTUCKY. SOME OF THIS MAY CONGEAL INTO AN
MCS AND TRACK TOWARDS THE AREA TOMORROW MORNING. THIS COULD BRING THE
THREAT OF DAMP WEATHER BACK TO THE AREA AROUND OR SHORTLY AFTER
DAYBREAK. AT THIS TIME...IT DOES NOT APPEAR THIS ACTIVITY WILL POSE A
SEVERE RISK AS SURFACE INSTABILITY WILL BE AT A MINIMUM EARLY IN THE
MORNING. IT LOOKING MORE LIKE WE MAY HAVE MORE OF A SEVERE THREAT
ARRIVING MONDAY EVENING OR MONDAY NIGHT AS WE MAY SEE AN MCS MOVE
INTO THE AREA INTO THE OVERNIGHT TIME PERIOD. THUS...SEVERE THREAT
APPEARS TO BE PUSHED BACK INTO MONDAY EVENING OR MONDAY NIGHT.
UPDATE ISSUED AT 745 PM EDT SUN APR 27 2014
A FEW SHOWERS AND STORMS BEGINNING TO ENCROACH UPON EASTERN KENTUCKY.
THE FIRST ONE IS JUST GRAZING THE WESTERN EDGE OF WAYNE COUNTY AS IT
MOVES NORTHWARD...WITH A SECONDARY AREA MOVING INTO SOUTHERN
BELL/WHITLEY COUNTIES. NOT MUCH OTHER ACTIVITY ON RADAR AT PRESENT
TIME. WITH MORE OF A STRATIFORM LIGHT RAIN DEVELOPING FARTHER TO THE
SOUTHWEST ACROSS NORTH CENTRAL TENNESSEE. STILL PLENTY OF DRY AIR IN
PLACE ACROSS EASTERN KENTUCKY WHICH WILL LIKELY PUT THE END TO ANY
STORM CHANCES AS STUFF TRIES TO PUSH INTO THE AREA. THUS...WITH SUN
SETTING...WE WILL BE LOSING ANY INSTABILITY WE HAVE OUT THERE WITH
THUNDERSTORMS DIMINISHING TOWARDS SHOWERS. EVEN THE SHOWERS WILL HAVE
A TOUGH TIME SURVIVING AS THEY MOVE INTO THE DRIER AIR IN THE EAST.
THUS...HAVE BACKED OFF POPS THIS EVENING INTO THE OVERNIGHT HOURS.
ALSO BACKED OFF THUNDER CHANCES AFTER THE NEXT HOUR OR SO. NEXT ROUND
OF SHOWERS AND THUNDERSTORMS REMAIN OUT ACROSS WESTERN TENNESSEE AND
WESTERN KENTUCKY AND IF IT HOLDS TOGETHER...WOULD NOT BE INTO THE
AREA UNTIL AFTER MIDNIGHT. UPDATED FORECAST IS ALREADY OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 355 PM EDT SUN APR 27 2014
STARTING INTO AN ACTIVE PERIOD DURING THE SHORT TERM. A SURFACE LOW
PRESSURE SYSTEM WILL REMAIN OVER THE CENTRAL PLAINS THIS
EVENING...WHILE SEVERAL WAVES OF ENERGY WILL CONTINUE TO ROTATE
AROUND THIS SYSTEM. EASTERN KY WILL REMAIN IN THE WARM SECTOR...WITH
A WARM FRONT POSITIONED ACROSS MUCH OF THE STATE.
MEANWHILE...WESTERN AND CENTRAL KY WILL FIND THEMSELVES POSITIONED
BETWEEN THE WARM FRONT AND COLD FRONT...WITH WARM UNSTABLE AIR
CONTINUING TO FILTER IN AND ABUNDANT MOISTURE TO ACCOMPANY.
WHILE NOT MUCH PROGRESSION IS EXPECTED THIS AFTERNOON OR TONIGHT IN
TERMS OF THE SURFACE LOW AND THE ASSOCIATED FRONTS...THE INCREASED
INSTABILITY DURING THE AFTERNOON WILL WORK TO HELP ANY CONVECTIVE
DEVELOPMENT TO SPREAD EASTWARD SLOWLY. LATEST HIRES
MODELS...INCLUDING THE NAM12/HRRR/AND ECMWF ALL POINT AT PRECIP
ENTERING INTO EASTERN KY BETWEEN 0 AND 6Z AND THEN CONTINUING
EASTWARD THROUGHOUT THE NIGHT. IT IS ALSO AROUND THIS POINT THAT
GFS40 AND NAM12 FORECAST SOUNDINGS SHOW SOME IMPRESSIVE LOW LEVEL
SHEER IN PORTIONS OF EASTERN KY. WHILE LINGERING DRY LOW LEVEL AIR
AND SE DOWNSLOPE WINDS COULD WORK TO HOLD OFF SOME PRECIP IN THE
EVENING...EXPECT THAT ISOLATED TO SCATTERED SHOWERS WILL DEVELOP. IN
DOING SO...MOISTENING OF THE LOW LEVELS WILL BE ENOUGH TO ALLOW
UNSTABLE AIR TO RISE AND THUNDERSTORMS TO DEVELOP. IN
ADDITION...BASED ON STRONG STORMS THAT HAVE DEVELOPED
UPSTREAM...HAVE KEPT THUNDER AS THE PREDOMINATE WX TYPE THIS EVENING
AND THROUGH THE NIGHT.
BETWEEN 3Z AND 12Z MONDAY...CHANCE POPS WILL OVERSPREAD THE AREA.
HOWEVER...LATEST HI-RES GUIDANCE IS POINTING AT A DRY POCKET
DEVELOPING AS DOWNSLOPE FLOW INCREASES SLIGHTLY ACROSS THE SOUTHEAST
PORTION OF THE STATE. LATEST RUC13 OMEGA IS ALSO SUPPORTIVE OF THIS
IDEA...SHOWING DOWNWARD MOTION ACROSS THE SE PORTION OF THE STATE BY
9Z. THE QUESTION THEN WILL BE...HOW MUCH WILL THIS DOWNSLOPING
INHIBIT ANY STORM DEVELOPMENT? HOW FAR INTO EASTERN KY COULD IT
POTENTIALLY INHIBIT STORM GROWTH AND RAIN...AND WILL WE STILL EXPECT
SOME ISOLATED TO SCATTERED CHANCES...OR WILL DOWNSLOPE CUT OFF
POTENTIAL ALL TOGETHER? UNFORTUNATELY...THESE ARE ALL QUESTIONS
WHICH CAN/T REALLY BE ANSWERED UNTIL THE MAIN CONVECTION REACHES OUR
AREA. UNTIL THEN...WILL TRY TO PLAY ON THIS THINKING...AND TREND
DOWN POPS SLIGHTLY FOR THE SE PORTION OF THE CWA.
DURING THE DAY TOMORROW...SURFACE LOW WILL HAVE PROGRESSED ONLY
SLIGHTLY EASTWARD...THOUGH THE SURFACE COLD FRONT WILL HAVE ENTERED
INTO THE MISSISSIPPI VALLEY REGION. WITH THE FORCING SO GREAT IN
PROXIMITY TO THIS FRONT...AND A STRONG PULL OF GULF
MOISTURE...EXPECT SHOWERS/TSRA TO OVERCOME THE DOWNSLOPING PULL.
ESPECIALLY IF WINDS SHIFT MORE SOUTHERLY FOR A PERIOD OF
TIME...COULD SEE MORE WIDESPREAD DEVELOPMENT ACROSS THIS AREA.
UNFORTUNATELY...EVEN THE HI-RES MODELS ARE SHOWING SOME DISAGREEMENT
ON THE EXTENT AND MAGNITUDE OF PRECIP FOR TOMORROW...SO HAVE TRIED
TO STICK TO A BLEND. Q VECTORS ARE SHOWING THE BEST AREAS FOR UPWARD
MOTION AND STORM DEVELOPMENT REMAINING JUST TO OUR NORTH
TOMORROW...MAINLY OVER THE UPPER GREAT LAKES REGION. SOME DECENT
CONVERGENCE DOES MAKE IT INTO KY AS WELL...MOVING FROM WEST TO EAST
ACROSS THE STATE. AS IT HEADS INTO EASTERN KY...EVEN THE QVECTOR
CONVERGENCE PICKS UP ON A BRIEF LULL IN ACTIVITY ACROSS THE SE
PORTION OF THE STATE WITH DOWNSLOPE WINDS IN PLACE. THIS QUICKLY
DISAPPEARS AS THE BEST CONVERGENCE MOVES OVER THE REGION...SO
FURTHER SUPPORT THAT AT SOME POINT THE MOISTURE WILL BE ENOUGH TO
OVERCOME ANY EFFECTS FROM THE WIND DIRECTION. LOW LEVEL WIND SHEAR
DURING THE DAY TOMORROW ISN/T QUITE AS IMPRESSIVE AS THAT EXPECTED
THIS EVENING...BUT IT SEEMS TO BE A BIT DEEPER. WINDS IN THE UPPER
LEVELS ARE QUITE STRONG...SO EXPECT A GOOD DRIVING FORCE AND THE
POTENTIAL FOR A LINE OF SHOWERS/STORMS TO TRAVERSE KY /AS WAS
REFLECTED IN THE MONDAY EVENING/MONDAY NIGHT POPS AND WEATHER/.
MONDAY NIGHT/S LINE OF STORMS IS ALSO EXPECTED TO BRING THE BEST
THREAT FOR HEAVY PRECIP DURING THE SHORT TERM ACCORDING TO THE LAST
FEW MODEL RUNS. AFTER ROUND ONE OF PRECIP MOVES IN TONIGHT AND
TOMORROW...A STRONGER SECOND LINE WILL DEVELOP CLOSER TO THE FRONT.
MOISTURE GETTING PULLED IN WILL ALLOW FOR 6 HOUR QPF AMOUNTS WELL IN
THE 1 TO 3 INCH RANGE BY 6Z TUESDAY...TRAVERSING EASTERN KY DURING
THIS TIME. WITH THIS AMOUNT OF EXPECTED CONVECTIVE RAIN...AND THE
CONTINUED POTENTIAL FOR SOME THUNDERSTORMS PRODUCING HEAVY SHOWERS
OVER SMALL AREAS...THERE DOES LIE THE THREAT OF FLOODING ACROSS
PORTIONS OF THE STATE...INCLUDING EASTERN KY. WINDS ALOFT ARE QUITE
IMPRESSIVE AS THIS LINE MOVES OVER...SO ANY STORMS OR HEAVY RAIN
SHOWERS BRING THE THREAT OF TRANSFERRING SOME OF THESE POTENTIALLY
DAMAGING WINDS TO THE GROUND. AS FAR AS THE FLOODING...WILL
PROBABLY NEED TO ISSUE A WATCH AT SOME POINT IN THE NEAR FUTURE.
ELECTED NOT TO DURING THE DAY SHIFT JUST FOR THE SHEER FACT THAT THE
MODELS ARE STILL HAVING A HARD TIME AGREEING...AND REALLY ITS GOING
TO BE A MATTER OF HOW MUCH PRECIP WE END UP RECEIVING OVERNIGHT
TONIGHT AND TOMORROW MORNING TO KNOW HOW SATURATED THE SOIL WILL BE
LEADING INTO THE EVENING. WILL MENTION CONCERNS TO INCOMING SHIFT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 425 PM EDT SUN APR 27 2014
THE MODELS CONTINUE TO BE IN GOOD AGREEMENT ALOFT WITH THE LARGE AND
LUMBERING CLOSED LOW OVER THE MID SECTION OF THE NATION AT THE START
OF THE EXTENDED. THIS DOMINANT FEATURE ROLLS OVER ON ITSELF AS IT
SLOWLY FILLS AND LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN
GREAT LAKES BY 00Z THURSDAY. THE SYSTEM BECOMES MORE PROGRESSIVE
TOWARD THE END OF THE WEEK...EVENTUALLY EXITING INTO EASTERN CANADA.
BEFORE IT DOES SO...A CONTINUATION OF A SERIES OF MID LEVEL ENERGY
PACKETS WILL PLOW THROUGH KENTUCKY BRINGING PERIODIC SUPPORT TO
CONVECTION THROUGHOUT THE REGION. FOR TUESDAY...A KEY ONE OF THESE
PACKETS MOVES OVER EAST KENTUCKY EARLY FOLLOWED BY ANOTHER LATE IN
THE DAY AND INTO EARLY WEDNESDAY. THESE PACKETS DO WEAKEN WITH TIME
SO THAT THE VERSION THAT GOES THROUGH ON MIDDAY WEDNESDAY WILL
LIKELY NOT PACK THE PUNCH OF THE EARLIER ONES. FALLING HEIGHTS
LOCALLY WILL BE NOTED INTO THURSDAY MORNING EVEN AS THE MAIN LOW TO
THE NORTH WEAKENS BUT BY THIS TIME THE ENERGY SWIRLING PAST WILL BE
SIMILARLY WEAKER. IT IS ALSO ABOUT THIS TIME THAT THE AGREEMENT OF
THE GEM WITH THE NEARLY LOCKSTEP ECMWF AND GFS AT MID LEVELS FADES
AND ITS SOLUTION IS SUBSEQUENTLY DISCOUNTED. THE OTHER MODELS
CONTINUE TO MAINTAIN LOWER THAN NORMAL 500MB HEIGHTS OVER EAST
KENTUCKY INTO THE WEEKEND DUE TO THE ARRIVAL OF ANOTHER...MORE
PROGRESSIVE AND OPEN...TROUGH FROM THE PLAINS. THE GFS IS A BIT
BETTER CONSOLIDATED WITH THIS THAN THE ECMWF AS IT TAKES ITS AXIS
THROUGH EAST KENTUCKY EARLY SATURDAY WHILE THE ECMWF SNEAKS A LEAD
WAVE THROUGH ON FRIDAY WITH THE REST OF THE SYSTEM PASSING THROUGH
LATER SATURDAY. HEIGHTS WILL THEN TICK UP IN THE WAKE OF THIS ACTION
TO CLOSE OUT THE WEEKEND ON A WELCOMED QUIETER NOTE. FOR THE
FORECAST HAVE FOLLOWED A GENERAL MODEL BLEND THROUGH THE REST OF THE
WORK WEEK WITH A SLIGHT PREFERENCE FOR THE LATEST ECMWF THEREAFTER.
SENSIBLE WEATHER WILL FEATURE AT LEAST ONE LAST STORMY DAY AND NIGHT
TO START THE EXTENDED. THE EXPECTATION IS THAT AN ONGOING CLUSTER OF
STORMS WILL BE MOVING OUT OF EASTERN KENTUCKY AT 12Z TUESDAY.
HOWEVER...THE NEXT SURGE OF LIFT ASSOCIATED WITH THE MID LEVEL WAVE
ROLLING INTO THE AREA LATER THAT DAY WILL START TO ACT ON THE
ENVIRONMENT OF EAST KENTUCKY DURING THE AFTERNOON. THIS WILL COMBINE
WITH THE MOIST BOUNDARY LAYER...HEATING THROUGH THE DAY...TO
GENERATE DECENT INSTABILITY LIKELY KICKING OFF ANOTHER CONVECTIVE
CLUSTER. WITH THE VEERING SHEAR PROFILE AND POTENTIAL FOR HIGHER
INSTABILITY BY EVENING TUESDAY...WILL CONTINUE THE THREAT OF STRONG
TO SEVERE STORMS. THESE STORMS MAY LINGER INTO THE NIGHT BEFORE
CLEARING OUT TO THE EAST ALONG WITH THE SYSTEM/S SLOW MOVING COLD
FRONT FINALLY PUSHING OUT OF THE AREA. THE NEARBY FRONT AND LOW MID
LEVEL HEIGHTS SHOULD LEAVE WEDNESDAY WITH A POTENTIAL FOR RENEWED
CONVECTION...THOUGH THE THUNDER THREAT WILL PROBABLY BE LIMITED TO
THE FAR EAST AND MAINLY EARLIER IN THE DAY. THE THREAT OF SHOWERS
WILL THEN CONTINUE THROUGH THE REST OF THE WORK WEEK AND INTO THE
FIRST PART OF THE WEEKEND WHILE LIMITED INSTABILITY AND COOLER
TEMPERATURES KEEP THE THREAT OF THUNDER TO A MINIMUM. HAVE GONE WITH
DRY WEATHER FOR SUNDAY AS HIGH PRESSURE SHOULD BE MOVING OVERHEAD.
TEMPERATURES WILL BE DEFINITELY ON THE COOL SIDE OF NORMAL FOR THE
BULK OF THE EXTENDED IN THE WAKE OF THE SYSTEM/S SLOW MOVING COLD
FRONT PASSING THROUGH ON WEDNESDAY. TUESDAY REMAINS THE MOST
CHALLENGING DAY FOR MAX TEMPERATURES DUE TO QUESTIONS OF CLEARING
BEHIND THE DEPARTING EARLY MORNING BATCH OF CONVECTION. MORE...AND
QUICKER...CLEARING WILL ALLOW TEMPERATURES TO SOAR INTO THE UPPER
70S AND ALSO SPIKE THE INSTABILITY MAKING FOR A BETTER POTENTIAL FOR
SEVERE WEATHER. HOWEVER...THERE IS A POTENTIAL FOR CONVECTIVE DEBRIS
AND LINGERING LOW CLOUDS/SHOWERS TO KEEP TEMPERATURES CAPPED AND
INSTABILITY/SVR POTENTIAL MORE LIMITED.
THE CR GRID LOAD CAME IN PRETTY GOOD FOR THE BULK OF THE EXTENDED...
THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...PARTICULARLY FOR
A DRY SUNDAY. DID ALSO FINE TUNE SOME LOW TEMP GRIDS LATER IN THE
FORECAST TO ALLOW FOR SOME ENHANCED RIDGE AND VALLEY DETAIL OVER THE
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 745 PM EDT SUN APR 27 2014
VFR CONDITIONS WILL START OFF THE EVENING AT THE TAF SITES. THESE VFR
CONDITIONS MAY HOLD THROUGH THE NIGHT GIVEN THE DRY LOW LEVEL IN
PLACE. IF WE CAN GET SOME BETTER SHOWER OR THUNDERSTORM ACTIVITY WE
COULD MOISTEN UP THE LOW LEVELS PROVIDING A BRIEF WINDOW OF MVFR CIGS
LATE TONIGHT. HOWEVER...AT THIS TIME...THIS LOOKS UNLIKELY.
OVERALL...PRECIPITATION CHANCES LOOK FAIRLY SMALL TONIGHT GIVEN THE
DRY LOW LEVELS. WE COULD SEE A SPRINKLE OR LIGHT RAIN SHOWER THROUGH
THE NIGHT...BUT SHOULD NOT PROVIDE TOO MUCH OF AN AVIATION CONCERN.
BETTER RAIN CHANCES WILL ARRIVE TOMORROW...BUT STILL UNCERTAINTY
REGARDING THE POTENTIAL TIMING OF ANY RAIN. A BRIEF PERIOD OF LLWS
MAY BE SEEN AT KSME AND KLOZ LATE TONIGHT BEFORE WE MIX OUT MONDAY
MORNING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
745 PM EDT SUN APR 27 2014
.UPDATE...
ISSUED AT 745 PM EDT SUN APR 27 2014
A FEW SHOWERS AND STORMS BEGINNING TO ENCROACH UPON EASTERN KENTUCKY.
THE FIRST ONE IS JUST GRAZING THE WESTERN EDGE OF WAYNE COUNTY AS IT
MOVES NORTHWARD...WITH A SECONDARY AREA MOVING INTO SOUTHERN
BELL/WHITLEY COUNTIES. NOT MUCH OTHER ACTIVITY ON RADAR AT PRESENT
TIME. WITH MORE OF A STRATIFORM LIGHT RAIN DEVELOPING FARTHER TO THE
SOUTHWEST ACROSS NORTH CENTRAL TENNESSEE. STILL PLENTY OF DRY AIR IN
PLACE ACROSS EASTERN KENTUCKY WHICH WILL LIKELY PUT THE END TO ANY
STORM CHANCES AS STUFF TRIES TO PUSH INTO THE AREA. THUS...WITH SUN
SETTING...WE WILL BE LOSING ANY INSTABILITY WE HAVE OUT THERE WITH
THUNDERSTORMS DIMINISHING TOWARDS SHOWERS. EVEN THE SHOWERS WILL HAVE
A TOUGH TIME SURVIVING AS THEY MOVE INTO THE DRIER AIR IN THE EAST.
THUS...HAVE BACKED OFF POPS THIS EVENING INTO THE OVERNIGHT HOURS.
ALSO BACKED OFF THUNDER CHANCES AFTER THE NEXT HOUR OR SO. NEXT ROUND
OF SHOWERS AND THUNDERSTORMS REMAIN OUT ACROSS WESTERN TENNESSEE AND
WESTERN KENTUCKY AND IF IT HOLDS TOGETHER...WOULD NOT BE INTO THE
AREA UNTIL AFTER MIDNIGHT. UPDATED FORECAST IS ALREADY OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 355 PM EDT SUN APR 27 2014
STARTING INTO AN ACTIVE PERIOD DURING THE SHORT TERM. A SURFACE LOW
PRESSURE SYSTEM WILL REMAIN OVER THE CENTRAL PLAINS THIS
EVENING...WHILE SEVERAL WAVES OF ENERGY WILL CONTINUE TO ROTATE
AROUND THIS SYSTEM. EASTERN KY WILL REMAIN IN THE WARM SECTOR...WITH
A WARM FRONT POSITIONED ACROSS MUCH OF THE STATE.
MEANWHILE...WESTERN AND CENTRAL KY WILL FIND THEMSELVES POSITIONED
BETWEEN THE WARM FRONT AND COLD FRONT...WITH WARM UNSTABLE AIR
CONTINUING TO FILTER IN AND ABUNDANT MOISTURE TO ACCOMPANY.
WHILE NOT MUCH PROGRESSION IS EXPECTED THIS AFTERNOON OR TONIGHT IN
TERMS OF THE SURFACE LOW AND THE ASSOCIATED FRONTS...THE INCREASED
INSTABILITY DURING THE AFTERNOON WILL WORK TO HELP ANY CONVECTIVE
DEVELOPMENT TO SPREAD EASTWARD SLOWLY. LATEST HIRES
MODELS...INCLUDING THE NAM12/HRRR/AND ECMWF ALL POINT AT PRECIP
ENTERING INTO EASTERN KY BETWEEN 0 AND 6Z AND THEN CONTINUING
EASTWARD THROUGHOUT THE NIGHT. IT IS ALSO AROUND THIS POINT THAT
GFS40 AND NAM12 FORECAST SOUNDINGS SHOW SOME IMPRESSIVE LOW LEVEL
SHEER IN PORTIONS OF EASTERN KY. WHILE LINGERING DRY LOW LEVEL AIR
AND SE DOWNSLOPE WINDS COULD WORK TO HOLD OFF SOME PRECIP IN THE
EVENING...EXPECT THAT ISOLATED TO SCATTERED SHOWERS WILL DEVELOP. IN
DOING SO...MOISTENING OF THE LOW LEVELS WILL BE ENOUGH TO ALLOW
UNSTABLE AIR TO RISE AND THUNDERSTORMS TO DEVELOP. IN
ADDITION...BASED ON STRONG STORMS THAT HAVE DEVELOPED
UPSTREAM...HAVE KEPT THUNDER AS THE PREDOMINATE WX TYPE THIS EVENING
AND THROUGH THE NIGHT.
BETWEEN 3Z AND 12Z MONDAY...CHANCE POPS WILL OVERSPREAD THE AREA.
HOWEVER...LATEST HI-RES GUIDANCE IS POINTING AT A DRY POCKET
DEVELOPING AS DOWNSLOPE FLOW INCREASES SLIGHTLY ACROSS THE SOUTHEAST
PORTION OF THE STATE. LATEST RUC13 OMEGA IS ALSO SUPPORTIVE OF THIS
IDEA...SHOWING DOWNWARD MOTION ACROSS THE SE PORTION OF THE STATE BY
9Z. THE QUESTION THEN WILL BE...HOW MUCH WILL THIS DOWNSLOPING
INHIBIT ANY STORM DEVELOPMENT? HOW FAR INTO EASTERN KY COULD IT
POTENTIALLY INHIBIT STORM GROWTH AND RAIN...AND WILL WE STILL EXPECT
SOME ISOLATED TO SCATTERED CHANCES...OR WILL DOWNSLOPE CUT OFF
POTENTIAL ALL TOGETHER? UNFORTUNATELY...THESE ARE ALL QUESTIONS
WHICH CAN/T REALLY BE ANSWERED UNTIL THE MAIN CONVECTION REACHES OUR
AREA. UNTIL THEN...WILL TRY TO PLAY ON THIS THINKING...AND TREND
DOWN POPS SLIGHTLY FOR THE SE PORTION OF THE CWA.
DURING THE DAY TOMORROW...SURFACE LOW WILL HAVE PROGRESSED ONLY
SLIGHTLY EASTWARD...THOUGH THE SURFACE COLD FRONT WILL HAVE ENTERED
INTO THE MISSISSIPPI VALLEY REGION. WITH THE FORCING SO GREAT IN
PROXIMITY TO THIS FRONT...AND A STRONG PULL OF GULF
MOISTURE...EXPECT SHOWERS/TSRA TO OVERCOME THE DOWNSLOPING PULL.
ESPECIALLY IF WINDS SHIFT MORE SOUTHERLY FOR A PERIOD OF
TIME...COULD SEE MORE WIDESPREAD DEVELOPMENT ACROSS THIS AREA.
UNFORTUNATELY...EVEN THE HI-RES MODELS ARE SHOWING SOME DISAGREEMENT
ON THE EXTENT AND MAGNITUDE OF PRECIP FOR TOMORROW...SO HAVE TRIED
TO STICK TO A BLEND. Q VECTORS ARE SHOWING THE BEST AREAS FOR UPWARD
MOTION AND STORM DEVELOPMENT REMAINING JUST TO OUR NORTH
TOMORROW...MAINLY OVER THE UPPER GREAT LAKES REGION. SOME DECENT
CONVERGENCE DOES MAKE IT INTO KY AS WELL...MOVING FROM WEST TO EAST
ACROSS THE STATE. AS IT HEADS INTO EASTERN KY...EVEN THE QVECTOR
CONVERGENCE PICKS UP ON A BRIEF LULL IN ACTIVITY ACROSS THE SE
PORTION OF THE STATE WITH DOWNSLOPE WINDS IN PLACE. THIS QUICKLY
DISAPPEARS AS THE BEST CONVERGENCE MOVES OVER THE REGION...SO
FURTHER SUPPORT THAT AT SOME POINT THE MOISTURE WILL BE ENOUGH TO
OVERCOME ANY EFFECTS FROM THE WIND DIRECTION. LOW LEVEL WIND SHEAR
DURING THE DAY TOMORROW ISN/T QUITE AS IMPRESSIVE AS THAT EXPECTED
THIS EVENING...BUT IT SEEMS TO BE A BIT DEEPER. WINDS IN THE UPPER
LEVELS ARE QUITE STRONG...SO EXPECT A GOOD DRIVING FORCE AND THE
POTENTIAL FOR A LINE OF SHOWERS/STORMS TO TRAVERSE KY /AS WAS
REFLECTED IN THE MONDAY EVENING/MONDAY NIGHT POPS AND WEATHER/.
MONDAY NIGHT/S LINE OF STORMS IS ALSO EXPECTED TO BRING THE BEST
THREAT FOR HEAVY PRECIP DURING THE SHORT TERM ACCORDING TO THE LAST
FEW MODEL RUNS. AFTER ROUND ONE OF PRECIP MOVES IN TONIGHT AND
TOMORROW...A STRONGER SECOND LINE WILL DEVELOP CLOSER TO THE FRONT.
MOISTURE GETTING PULLED IN WILL ALLOW FOR 6 HOUR QPF AMOUNTS WELL IN
THE 1 TO 3 INCH RANGE BY 6Z TUESDAY...TRAVERSING EASTERN KY DURING
THIS TIME. WITH THIS AMOUNT OF EXPECTED CONVECTIVE RAIN...AND THE
CONTINUED POTENTIAL FOR SOME THUNDERSTORMS PRODUCING HEAVY SHOWERS
OVER SMALL AREAS...THERE DOES LIE THE THREAT OF FLOODING ACROSS
PORTIONS OF THE STATE...INCLUDING EASTERN KY. WINDS ALOFT ARE QUITE
IMPRESSIVE AS THIS LINE MOVES OVER...SO ANY STORMS OR HEAVY RAIN
SHOWERS BRING THE THREAT OF TRANSFERRING SOME OF THESE POTENTIALLY
DAMAGING WINDS TO THE GROUND. AS FAR AS THE FLOODING...WILL
PROBABLY NEED TO ISSUE A WATCH AT SOME POINT IN THE NEAR FUTURE.
ELECTED NOT TO DURING THE DAY SHIFT JUST FOR THE SHEER FACT THAT THE
MODELS ARE STILL HAVING A HARD TIME AGREEING...AND REALLY ITS GOING
TO BE A MATTER OF HOW MUCH PRECIP WE END UP RECEIVING OVERNIGHT
TONIGHT AND TOMORROW MORNING TO KNOW HOW SATURATED THE SOIL WILL BE
LEADING INTO THE EVENING. WILL MENTION CONCERNS TO INCOMING SHIFT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 425 PM EDT SUN APR 27 2014
THE MODELS CONTINUE TO BE IN GOOD AGREEMENT ALOFT WITH THE LARGE AND
LUMBERING CLOSED LOW OVER THE MID SECTION OF THE NATION AT THE START
OF THE EXTENDED. THIS DOMINANT FEATURE ROLLS OVER ON ITSELF AS IT
SLOWLY FILLS AND LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN
GREAT LAKES BY 00Z THURSDAY. THE SYSTEM BECOMES MORE PROGRESSIVE
TOWARD THE END OF THE WEEK...EVENTUALLY EXITING INTO EASTERN CANADA.
BEFORE IT DOES SO...A CONTINUATION OF A SERIES OF MID LEVEL ENERGY
PACKETS WILL PLOW THROUGH KENTUCKY BRINGING PERIODIC SUPPORT TO
CONVECTION THROUGHOUT THE REGION. FOR TUESDAY...A KEY ONE OF THESE
PACKETS MOVES OVER EAST KENTUCKY EARLY FOLLOWED BY ANOTHER LATE IN
THE DAY AND INTO EARLY WEDNESDAY. THESE PACKETS DO WEAKEN WITH TIME
SO THAT THE VERSION THAT GOES THROUGH ON MIDDAY WEDNESDAY WILL
LIKELY NOT PACK THE PUNCH OF THE EARLIER ONES. FALLING HEIGHTS
LOCALLY WILL BE NOTED INTO THURSDAY MORNING EVEN AS THE MAIN LOW TO
THE NORTH WEAKENS BUT BY THIS TIME THE ENERGY SWIRLING PAST WILL BE
SIMILARLY WEAKER. IT IS ALSO ABOUT THIS TIME THAT THE AGREEMENT OF
THE GEM WITH THE NEARLY LOCKSTEP ECMWF AND GFS AT MID LEVELS FADES
AND ITS SOLUTION IS SUBSEQUENTLY DISCOUNTED. THE OTHER MODELS
CONTINUE TO MAINTAIN LOWER THAN NORMAL 500MB HEIGHTS OVER EAST
KENTUCKY INTO THE WEEKEND DUE TO THE ARRIVAL OF ANOTHER...MORE
PROGRESSIVE AND OPEN...TROUGH FROM THE PLAINS. THE GFS IS A BIT
BETTER CONSOLIDATED WITH THIS THAN THE ECMWF AS IT TAKES ITS AXIS
THROUGH EAST KENTUCKY EARLY SATURDAY WHILE THE ECMWF SNEAKS A LEAD
WAVE THROUGH ON FRIDAY WITH THE REST OF THE SYSTEM PASSING THROUGH
LATER SATURDAY. HEIGHTS WILL THEN TICK UP IN THE WAKE OF THIS ACTION
TO CLOSE OUT THE WEEKEND ON A WELCOMED QUIETER NOTE. FOR THE
FORECAST HAVE FOLLOWED A GENERAL MODEL BLEND THROUGH THE REST OF THE
WORK WEEK WITH A SLIGHT PREFERENCE FOR THE LATEST ECMWF THEREAFTER.
SENSIBLE WEATHER WILL FEATURE AT LEAST ONE LAST STORMY DAY AND NIGHT
TO START THE EXTENDED. THE EXPECTATION IS THAT AN ONGOING CLUSTER OF
STORMS WILL BE MOVING OUT OF EASTERN KENTUCKY AT 12Z TUESDAY.
HOWEVER...THE NEXT SURGE OF LIFT ASSOCIATED WITH THE MID LEVEL WAVE
ROLLING INTO THE AREA LATER THAT DAY WILL START TO ACT ON THE
ENVIRONMENT OF EAST KENTUCKY DURING THE AFTERNOON. THIS WILL COMBINE
WITH THE MOIST BOUNDARY LAYER...HEATING THROUGH THE DAY...TO
GENERATE DECENT INSTABILITY LIKELY KICKING OFF ANOTHER CONVECTIVE
CLUSTER. WITH THE VEERING SHEAR PROFILE AND POTENTIAL FOR HIGHER
INSTABILITY BY EVENING TUESDAY...WILL CONTINUE THE THREAT OF STRONG
TO SEVERE STORMS. THESE STORMS MAY LINGER INTO THE NIGHT BEFORE
CLEARING OUT TO THE EAST ALONG WITH THE SYSTEM/S SLOW MOVING COLD
FRONT FINALLY PUSHING OUT OF THE AREA. THE NEARBY FRONT AND LOW MID
LEVEL HEIGHTS SHOULD LEAVE WEDNESDAY WITH A POTENTIAL FOR RENEWED
CONVECTION...THOUGH THE THUNDER THREAT WILL PROBABLY BE LIMITED TO
THE FAR EAST AND MAINLY EARLIER IN THE DAY. THE THREAT OF SHOWERS
WILL THEN CONTINUE THROUGH THE REST OF THE WORK WEEK AND INTO THE
FIRST PART OF THE WEEKEND WHILE LIMITED INSTABILITY AND COOLER
TEMPERATURES KEEP THE THREAT OF THUNDER TO A MINIMUM. HAVE GONE WITH
DRY WEATHER FOR SUNDAY AS HIGH PRESSURE SHOULD BE MOVING OVERHEAD.
TEMPERATURES WILL BE DEFINITELY ON THE COOL SIDE OF NORMAL FOR THE
BULK OF THE EXTENDED IN THE WAKE OF THE SYSTEM/S SLOW MOVING COLD
FRONT PASSING THROUGH ON WEDNESDAY. TUESDAY REMAINS THE MOST
CHALLENGING DAY FOR MAX TEMPERATURES DUE TO QUESTIONS OF CLEARING
BEHIND THE DEPARTING EARLY MORNING BATCH OF CONVECTION. MORE...AND
QUICKER...CLEARING WILL ALLOW TEMPERATURES TO SOAR INTO THE UPPER
70S AND ALSO SPIKE THE INSTABILITY MAKING FOR A BETTER POTENTIAL FOR
SEVERE WEATHER. HOWEVER...THERE IS A POTENTIAL FOR CONVECTIVE DEBRIS
AND LINGERING LOW CLOUDS/SHOWERS TO KEEP TEMPERATURES CAPPED AND
INSTABILITY/SVR POTENTIAL MORE LIMITED.
THE CR GRID LOAD CAME IN PRETTY GOOD FOR THE BULK OF THE EXTENDED...
THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...PARTICULARLY FOR
A DRY SUNDAY. DID ALSO FINE TUNE SOME LOW TEMP GRIDS LATER IN THE
FORECAST TO ALLOW FOR SOME ENHANCED RIDGE AND VALLEY DETAIL OVER THE
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 745 PM EDT SUN APR 27 2014
VFR CONDITIONS WILL START OFF THE EVENING AT THE TAF SITES. THESE VFR
CONDITIONS MAY HOLD THROUGH THE NIGHT GIVEN THE DRY LOW LEVEL IN
PLACE. IF WE CAN GET SOME BETTER SHOWER OR THUNDERSTORM ACTIVITY WE
COULD MOISTEN UP THE LOW LEVELS PROVIDING A BRIEF WINDOW OF MVFR CIGS
LATE TONIGHT. HOWEVER...AT THIS TIME...THIS LOOKS UNLIKELY.
OVERALL...PRECIPITATION CHANCES LOOK FAIRLY SMALL TONIGHT GIVEN THE
DRY LOW LEVELS. WE COULD SEE A SPRINKLE OR LIGHT RAIN SHOWER THROUGH
THE NIGHT...BUT SHOULD NOT PROVIDE TOO MUCH OF AN AVIATION CONCERN.
BETTER RAIN CHANCES WILL ARRIVE TOMORROW...BUT STILL UNCERTAINTY
REGARDING THE POTENTIAL TIMING OF ANY RAIN. A BRIEF PERIOD OF LLWS
MAY BE SEEN AT KSME AND KLOZ LATE TONIGHT BEFORE WE MIX OUT MONDAY
MORNING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
943 PM CDT SUN APR 27 2014
.DISCUSSION...
UPDATED THE AREAL DISTRIBUTION OF POPS TO MORE CLOSELY FOLLOW THE
HRR (HIGH RESOLUTION RAPID REFRESH) SOLUTION. OTHERWISE...THE
ZONE PACKAGE IS ON TARGET.
JT
&&
.PREV DISCUSSION... /ISSUED 630 PM CDT SUN APR 27 2014/
DISCUSSION...
FOR 00Z TAFS...VFR TO MVFR CONDITIONS EXPECTED THIS EVENING...WITH
GUSTY SOUTH WINDS. NOT EXPECTING THE NEXT ROUND OF PRECIP UNTIL
TOWARDS DAYBREAK...BUT LOW CONFIDENCE ON COVERAGE AT THIS POINT.
PREV DISCUSSION... /ISSUED 436 PM CDT SUN APR 27 2014/
DISCUSSION...
LATEST WATER VAPOR SATELLITE IMAGERY SHOWED A VIGOROUS UPPER LOW
OVER NW KS/SW NE...WITH A VIGOROUS PACIFIC JET NOSING IN FROM THE
PAC NW AND CURLING CYCLONICALLY THROUGH THE BASE OF THE LOW. A
SUBTROPICAL JET WAS NOTED TO THE SOUTH ACROSS CENTRAL MX INTO THE
WRN GULF. KLCH AND KPOE VWPS CONTINUE TO SHOW A 50KT PLUS
SOUTHWESTERLY LLJ.
AT THE SFC...LOW PRESSURE IS HARD TO MISS OVER NW KS...WITH A
TRAILING CDFNT/DRYLINE THROUGH CENTRAL OK/TX.
HARD TO HAVE A GREAT DEAL OF FAITH IN ANY SPECIFIC SHORT TERM
GUIDANCE...AS PRECIOUS FEW CAUGHT THE ISOLATED TO SCATTERED
ELEVATED CONVECTION THAT DEVELOPED THIS AFTERNOON. THE ONLINE SPC
4KM WRF WASNT TOO BAD...AND THE HRRR DID FINALLY CATCH ON. THESE
TWO MODELS...WITH SOME ADDITIONAL SUPPORT FROM GLOBAL
MODELS...DEPICT A BAND OF CONVECTION INITIATING AFTER MIDNIGHT IN
THE VICINITY OF EAST CENTRAL TEXAS NE TWD SHREVEPORT. THE
SOUTHWESTWARD EXTENT OF ANY SUCH DEVELOPMENT IS A BIT
UNCERTAIN...BUT IT IS NOT OUT OF THE QUESTION FOR NORTHERN ZONES
TO BE AFFECTED GIVEN THE THE PROJECTED EAST/NORTHEAST MOVEMENT.
WILL MAINTAIN HIGHEST POPS TONIGHT IN THIS AREA...AND HOLD ONTO
THE SEVERE WORDING.
GENERALLY PRESERVED THE INHERITED INLAND WIND HAZARDS...BUT DID
TWEAK THE MARINE HAZARDS A BIT...EASING OUT OF THE SCA FOR THE
COASTAL LAKES AND BAYS MID EVENING...AND THE INLAND WATERS WEST OF
CAMERON AFTER MIDNIGHT CONCURRENT WITH LATEST PROGS THAT SHOW
WINDS STARTING TO DECREASE FROM WEST TO EAST OVERNIGHT AND INTO
TOMORROW. A WIND ADVISORY MAY STILL BE WARRANTED FOR A TIME ACROSS
SOUTH/EAST CENTRAL LOUISIANA...BUT WILL LET THE OVERNIGHT CREW
MAKE THE CALL ON THAT AS IT LOOKS A LITTLE MORE MARGINAL.
CONVECTIVE PROSPECTS WILL ALSO SHIFT EAST TOMORROW...AS THE
CDFNT PUSHES JUST EAST OF A KSHV TO KLFK LINE BY TOMORROW
AFTERNOON. HAVE GENERALLY LEFT THIS PART OF THE FORECAST AS
IS...STAYING MAINLY WITH LOW TO MID RANGE POPS AND PRESERVING THE
SEVERE WORDING PER SPC DAY 2 CONVECTIVE OUTLOOK.
THE FRONT IS STILL FCST TO PUSH THROUGH THE DURING THE AFTERNOON
AND EVENING HOURS ON TUE...WITH THE SEVERE RISK DISPLACED TO OUR
EAST BY THIS TIME. ALTHOUGH STILL NOT IN IDEAL AGREEMENT...THE GFS
HAS COME A LONG WAY TOWARD THE ECMWF SOLUTION IN DEPICTING
SOUTHWESTERLY FLOW ALOFT...WITH ONE OR MORE FRONTAL WAVES/LOWS
DEVELOPING ALONG THE FRONT. APPEARS THAT THE BEST CHANCE OF ANY
RAIN AFFECTING THE AREA WOULD BE THU NIGHT-FRI...AS BOTH MODELS
DEPICTING A SHORTWAVE TROF PIVOTING THROUGH THE NW GULF COAST
REGION.
MARINE...
GUSTY SOUTH WINDS AND ROUGH SEAS WILL CONTINUE THIS EVENING AS A
LOW PRESSURE SYSTEM DEVELOPS IN THE PLAINS. WINDS WILL BEGIN TO
DIMINISH A BIT OVER THE COASTAL LAKES AND BAYS TONIGHT AND THE
WATERS WEST OF CAMERON LATE TONIGHT INTO TOMORROW. TIDES WILL BE
RUNNING ABOUT ONE FOOT ABOVE NORMAL TODAY AND MONDAY. THE CHANCE
OF SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE INTO EARLY NEXT
WEEK AS THIS LOW PRESSURE SYSTEM SLOWLY MOVES EAST THROUGH THE
CENTRAL UNTIED STATES...CULMINATING IN A FRONT CROSSING THE REGION
TUESDAY NIGHT. OFFSHORE FLOW WILL PREVAIL IN THE WAKE OF THE FRONT
FOR THE REST OF THE WORK WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 72 84 70 85 57 / 20 30 20 20 20
KBPT 72 84 69 85 58 / 20 20 20 20 10
KAEX 71 85 67 83 53 / 50 50 30 30 10
KLFT 72 84 71 85 58 / 30 40 40 30 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING
ZONES: ACADIA...CALCASIEU...EAST CAMERON...IBERIA...
JEFFERSON DAVIS...LAFAYETTE...LOWER ST. MARTIN...ST. MARY...
UPPER ST. MARTIN...VERMILION...WEST CAMERON.
TX...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING
ZONES: JEFFERSON...ORANGE.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO
INTRACOASTAL CITY LA OUT 20 NM...WATERS FROM INTRACOASTAL
CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON
LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM.
SMALL CRAFT EXERCISE CAUTION UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE.
SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE
FOLLOWING ZONES: VERMILION BAY.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM.
SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM.
&&
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV
WWW.TWITTER.COM/NWSLAKECHARLES
WWW.YOUTUBE.COM/NWSLAKECHARLES
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
630 PM CDT SUN APR 27 2014
.DISCUSSION...
FOR 00Z TAFS...VFR TO MVFR CONDITIONS EXPECTED THIS EVENING...WITH
GUSTY SOUTH WINDS. NOT EXPECTING THE NEXT ROUND OF PRECIP UNTIL
TOWARDS DAYBREAK...BUT LOW CONFIDENCE ON COVERAGE AT THIS POINT.
&&
.PREV DISCUSSION... /ISSUED 436 PM CDT SUN APR 27 2014/
DISCUSSION...
LATEST WATER VAPOR SATELLITE IMAGERY SHOWED A VIGOROUS UPPER LOW
OVER NW KS/SW NE...WITH A VIGOROUS PACIFIC JET NOSING IN FROM THE
PAC NW AND CURLING CYCLONICALLY THROUGH THE BASE OF THE LOW. A
SUBTROPICAL JET WAS NOTED TO THE SOUTH ACROSS CENTRAL MX INTO THE
WRN GULF. KLCH AND KPOE VWPS CONTINUE TO SHOW A 50KT PLUS
SOUTHWESTERLY LLJ.
AT THE SFC...LOW PRESSURE IS HARD TO MISS OVER NW KS...WITH A
TRAILING CDFNT/DRYLINE THROUGH CENTRAL OK/TX.
HARD TO HAVE A GREAT DEAL OF FAITH IN ANY SPECIFIC SHORT TERM
GUIDANCE...AS PRECIOUS FEW CAUGHT THE ISOLATED TO SCATTERED
ELEVATED CONVECTION THAT DEVELOPED THIS AFTERNOON. THE ONLINE SPC
4KM WRF WASNT TOO BAD...AND THE HRRR DID FINALLY CATCH ON. THESE
TWO MODELS...WITH SOME ADDITIONAL SUPPORT FROM GLOBAL
MODELS...DEPICT A BAND OF CONVECTION INITIATING AFTER MIDNIGHT IN
THE VICINITY OF EAST CENTRAL TEXAS NE TWD SHREVEPORT. THE
SOUTHWESTWARD EXTENT OF ANY SUCH DEVELOPMENT IS A BIT
UNCERTAIN...BUT IT IS NOT OUT OF THE QUESTION FOR NORTHERN ZONES
TO BE AFFECTED GIVEN THE THE PROJECTED EAST/NORTHEAST MOVEMENT.
WILL MAINTAIN HIGHEST POPS TONIGHT IN THIS AREA...AND HOLD ONTO
THE SEVERE WORDING.
GENERALLY PRESERVED THE INHERITED INLAND WIND HAZARDS...BUT DID
TWEAK THE MARINE HAZARDS A BIT...EASING OUT OF THE SCA FOR THE
COASTAL LAKES AND BAYS MID EVENING...AND THE INLAND WATERS WEST OF
CAMERON AFTER MIDNIGHT CONCURRENT WITH LATEST PROGS THAT SHOW
WINDS STARTING TO DECREASE FROM WEST TO EAST OVERNIGHT AND INTO
TOMORROW. A WIND ADVISORY MAY STILL BE WARRANTED FOR A TIME ACROSS
SOUTH/EAST CENTRAL LOUISIANA...BUT WILL LET THE OVERNIGHT CREW
MAKE THE CALL ON THAT AS IT LOOKS A LITTLE MORE MARGINAL.
CONVECTIVE PROSPECTS WILL ALSO SHIFT EAST TOMORROW...AS THE
CDFNT PUSHES JUST EAST OF A KSHV TO KLFK LINE BY TOMORROW
AFTERNOON. HAVE GENERALLY LEFT THIS PART OF THE FORECAST AS
IS...STAYING MAINLY WITH LOW TO MID RANGE POPS AND PRESERVING THE
SEVERE WORDING PER SPC DAY 2 CONVECTIVE OUTLOOK.
THE FRONT IS STILL FCST TO PUSH THROUGH THE DURING THE AFTERNOON
AND EVENING HOURS ON TUE...WITH THE SEVERE RISK DISPLACED TO OUR
EAST BY THIS TIME. ALTHOUGH STILL NOT IN IDEAL AGREEMENT...THE GFS
HAS COME A LONG WAY TOWARD THE ECMWF SOLUTION IN DEPICTING
SOUTHWESTERLY FLOW ALOFT...WITH ONE OR MORE FRONTAL WAVES/LOWS
DEVELOPING ALONG THE FRONT. APPEARS THAT THE BEST CHANCE OF ANY
RAIN AFFECTING THE AREA WOULD BE THU NIGHT-FRI...AS BOTH MODELS
DEPICTING A SHORTWAVE TROF PIVOTING THROUGH THE NW GULF COAST
REGION.
MARINE...
GUSTY SOUTH WINDS AND ROUGH SEAS WILL CONTINUE THIS EVENING AS A
LOW PRESSURE SYSTEM DEVELOPS IN THE PLAINS. WINDS WILL BEGIN TO
DIMINISH A BIT OVER THE COASTAL LAKES AND BAYS TONIGHT AND THE
WATERS WEST OF CAMERON LATE TONIGHT INTO TOMORROW. TIDES WILL BE
RUNNING ABOUT ONE FOOT ABOVE NORMAL TODAY AND MONDAY. THE CHANCE
OF SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE INTO EARLY NEXT
WEEK AS THIS LOW PRESSURE SYSTEM SLOWLY MOVES EAST THROUGH THE
CENTRAL UNTIED STATES...CULMINATING IN A FRONT CROSSING THE REGION
TUESDAY NIGHT. OFFSHORE FLOW WILL PREVAIL IN THE WAKE OF THE FRONT
FOR THE REST OF THE WORK WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 72 84 70 85 57 / 20 30 20 20 20
KBPT 72 84 69 85 58 / 20 20 20 20 10
KAEX 71 85 67 83 53 / 50 50 30 30 10
KLFT 72 84 71 85 58 / 30 40 40 30 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING
ZONES: ACADIA...CALCASIEU...EAST CAMERON...IBERIA...
JEFFERSON DAVIS...LAFAYETTE...LOWER ST. MARTIN...ST. MARY...
UPPER ST. MARTIN...VERMILION...WEST CAMERON.
WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: ALLEN...AVOYELLES...BEAUREGARD...EVANGELINE...
RAPIDES...ST. LANDRY...VERNON.
TX...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING
ZONES: JEFFERSON...ORANGE.
WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: HARDIN...NORTHERN JASPER...NORTHERN NEWTON...
SOUTHERN JASPER...SOUTHERN NEWTON...TYLER.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO
INTRACOASTAL CITY LA OUT 20 NM...WATERS FROM INTRACOASTAL
CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON
LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE...VERMILION
BAY.
SMALL CRAFT EXERCISE CAUTION UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE.
SMALL CRAFT EXERCISE CAUTION THROUGH MONDAY MORNING FOR THE
FOLLOWING ZONES: VERMILION BAY.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM.
SMALL CRAFT EXERCISE CAUTION FROM MIDNIGHT CDT TONIGHT THROUGH
MONDAY MORNING FOR THE FOLLOWING ZONES: COASTAL WATERS FROM
CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS
FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM.
&&
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV
WWW.TWITTER.COM/NWSLAKECHARLES
WWW.YOUTUBE.COM/NWSLAKECHARLES
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
930 PM EDT SUN APR 27 2014
.SYNOPSIS...
LOW PRESSURE SOUTH OF NOVA SCOTIA WILL CONTINUE MOVING INTO THE
OPEN ATLANTIC TONIGHT INTO MONDAY. HIGH PRESSURE WILL BUILD SOUTH
ACROSS THE REGION MONDAY NIGHT THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
930 PM UPDATE...MOISTURE CONTINUES TO PUSH TO THE WEST/SOUTHWEST
ACROSS THE CWA ASSOCIATED WITH AN AREA OF LOW PRES EAST OF NOVA
SCOTIA. SCATTERED SHOWERS MAINLY ACROSS THE NORTHEAST CORNER OF
THE CWA AS OF 9 PM. THE SHOWERS HAVE BEEN LIGHT WITH RAINFALL
AMOUNTS OF A TRACE TO A COUPLE HUNDREDTHS OF AN INCH IN ANY
THE SPOTS THAT HAVE PICKED UP A SHOWER OVER PAST FEW HOURS. THE
00Z KCAR RAOB WAS BELOW 0C ABOVE 925 MILLIBARS...AND WITH A BIT
OF LOW LEVEL COOLING OVERNIGHT THE SHOWERS COULD MIX WITH OR
CHANGE TO SNOW SHOWERS LATE TONIGHT ACROSS NORTHERN MAINE AND OVER
THE WESTERN MOUNTAINS AS THE SHOWERS CONTINUE TO PUSH OFF TO THE
WEST. LITTLE/NO SNOW ACCUMULATION IS EXPECTED. ONLY MINOR CHANGES
TO THE ONGOING FORECAST BASED ON THE LATEST OBSERVATIONS...RADAR
TRENDS...AND NEAR TERM MODELS.
PREVIOUS DISCUSSION...
THE CHALLENGE WILL DEFINITELY BE THE TEMPERATURES AND WHERE TO
PLACE RAINFALL CHANCES.
LOW PRES WAS SPINNING SE OF NOVA SCOTIA PER THE 18Z ANALYSIS. SFC
TROUGH EXTENDING OFF THIS LOW EXTENDED BACK EASTERN AND CENTRAL
MAINE. THE FIRST BATCH OF LIGHT RAIN/SHOWERS MOVED SSW EARLY TODAY
AND ANOTHER ROUND IS APPROACHING FROM NEW BRUNSWICK. THE RAIN HAS
BEEN WEAKENING AS IT RUNS INTO DRIER AIR AS SEEN BY THE LATEST
SATELLITE VISIBLE IMAGERY SHOWING BREAKS IN THE CLOUDS. BEST
SUPPORT FOR SUBSTANTIAL RAIN HAS BEEN OVER THE EASTERN SECTIONS OF
WASHINGTON COUNTY. DECENT LLVL CONVERGENCE AND MID LEVEL FORCING
IS THERE AS SEEN BY BOTH THE RAP AND NAM12. EXPECTING THIS TREND
TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. CARRIED CHANCE
POPS(30-50%) FOR THE CWA TONIGHT W/THE HIGHEST CHANCES ACROSS
NORTHERN AND EASTERN SECTIONS. AS ONE TRAVELS FURTHER W AND SW,
SHOWERS WILL WEAKEN DUE TO SUBSIDENCE IN PLACE. CLOUDS WILL HANG
AROUND THROUGHOUT THE NIGHT AND THIS WILL KEEP TEMPERATURES WELL
ABOVE 32F WHICH SHOULD ALLOW FOR ALL LIQUID PRECIP. RAINFALL
AMOUNTS HAVE BEEN LIGHT AND SEE NO SUPPORT FOR THIS TO CHANGE MUCH
OVER THE NEXT 24 HRS. THEREFORE, STAYED W/QPF OF 0.10" OR LESS
THROUGH MONDAY.
CONDITIONS LOOK TO IMPROVE THROUGHOUT THE DAY ON MONDAY AS HIGH
PRES IS FORECAST TO WEDGE DOWN FROM CANADA. SOME SUNSHINE IS
EXPECTED BY MONDAY AFTERNOON ESPECIALLY ACROSS THE NORTHERN AND
EASTERN SECTIONS WHILE THE CENTRAL HIGHLANDS WILL HANG ON TO MORE
CLOUDS. THIS WILL LEAD TO A VARIATION IN TEMPERATURES. DECIDED TO
BOOST DAYTIME HIGHS ON MONDAY UP TO READINGS AOA 50F MAINLY FOR
THE NORTHERN AND EASTERN SECTIONS. CENTRAL AND WESTERN AREAS WILL
HANG W/MORE CLOUDS THUS KEEPING TEMPERATURES DOWN INTO THE 40S
SOMEWHAT SIMILAR TO TODAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL RIDGE SOUTH ACROSS THE REGION MONDAY NIGHT
THROUGH EARLY WEDNESDAY...THEN BEGIN TO MOVE EAST LATER WEDNESDAY.
CLOUD COVER WILL DECREASE ACROSS THE REGION MONDAY NIGHT. MOSTLY
CLEAR SKIES WILL OCCUR ACROSS THE REGION TUESDAY INTO EARLY
WEDNESDAY. CLOUD COVER WILL THEN BEGIN TO INCREASE LATER
WEDNESDAY...PARTICULARLY ACROSS WESTERN PORTIONS OF THE FORECAST
AREA. TEMPERATURES WILL BE AT NEAR NORMAL...TO SLIGHTLY BELOW
NORMAL...LEVELS TUESDAY/WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UNSETTLED PATTERN WILL TAKE HOLD ONCE AGAIN FOR THE LONG RANGE
AS THE RIDGE BREAKS DOWN AND THE NEXT UPPER LEVEL LOW ADVANCES
TOWARD THE REGION. CLOUDS WILL INCREASE WEDNESDAY NIGHT WITH RAIN
AND SHOWERS DEVELOPING WEST TO EAST FOR THURSDAY AS AN OCCLUSION
MOVES THROUGH AHEAD OF A SURFACE LOW ADVANCING NORTH ALONG THE
COAST. STEADIER RAIN LOOKS TO TAPER OFF THURSDAY NIGHT WITH RAIN
AMOUNTS OF A HALF INCH TO AN INCH POSSIBLE BY THIS TIME. EXPECT
SHOWERS TO LINGER INTO FRIDAY IN ASSOCIATION WITH THE BROAD UPPER
LEVEL LOW SITUATED OVER THE GREAT LAKES BY THIS TIME AND A
LINGERING SURFACE TROUGH.
SOME UNCERTAINTY DEVELOPS IN THE FORECAST FOR THE BEGINNING OF
NEXT WEEKEND. OVERALL, THE UNSETTLED PATTERN REMAINS HOWEVER THE
ECMWF MODEL BRINGS A BRIEF WINDOW OF SOME PARTIAL CLEARING AND
DRYING IN FOR SATURDAY WHILE THE GFS SUGGESTS MORE CLOUDS WITH AT
LEAST A FEW LINGERING SHOWERS. AT THIS POINT WILL KEEP IN THE
CHANCE OF SHOWERS WITH MOSTLY CLOUDY SKIES. A BETTER CHANCE FOR
MORE WIDESPREAD RAIN AND SHOWERS DEVELOPS ONCE AGAIN FOR SATURDAY
NIGHT AND SUNDAY AS THE NEXT SURFACE WAVE ASSOCIATED WITH THE
BROAD UPPER TROUGH DEVELOPS SOUTH OF THE REGION AND MOVES NORTH UP
THE COAST. TEMPERATURES THROUGH THE LONG RANGE ARE FORECAST TO
REMAIN WITHIN A FEW DEGREES OF AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR AT ALL THE TERMINALS AS OF 01Z. EXPECTATION IS
FOR CIGS TO DROP TO MVFR ACROSS ALL THE TERMINALS OVERNIGHT. A
PERIOD OF IFR IS POSSIBLE LATE TONIGHT(AFT 08Z) AND THIS WILL
MAINLY BE FOR THE NORTHERN TERMINALS. DECIDED TO STAY W/MVFR
THROUGH MIDDAY MONDAY. AN IMPROVEMENT TO VFR IS EXPECTED BY MON
EVENING.
SHORT TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE REGION MONDAY
NIGHT THROUGH WEDNESDAY. VFR WEDNESDAY NIGHT WILL GIVE WAY TO
MVFR AND THEN IFR THURSDAY AS RAIN MOVES IN FROM WEST TO EAST.
MVFR/IFR CONDITIONS ARE LIKELY TO PERSIST INTO FRIDAY DUE TO LOW
STRATUS WITH LINGERING SHOWERS.
&&
.MARINE...
NEAR TERM: NO SCA ATTM. LATEST MODEL GUIDANCE HAS BEEN RUNNING TOO
HIGH FOR THE WINDS AND ADJUSTMENTS WERE MADE TO PUSH THE SPEEDS
BACK. THE WIND WILL GRADUALLY INCREASE OVER THE NEXT 24 HOURS AND
THE SEAS WILL SLOWLY BUILD. A SCA MAY BE NEEDED BY LATE MONDAY.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE ON THE
WATERS MONDAY NIGHT INTO EARLY TUESDAY NIGHT. CONDITIONS ARE
EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS LATER TUESDAY
NIGHT INTO WEDNESDAY. SCA CONDITIONS WILL BE POSSIBLE THURSDAY AS
SE WINDS STRENGTHEN AND WAVE HEIGHTS INCREASE AHEAD OF AN
OCCLUSION MOVING THROUGH WHICH WILL ALSO BRING RAIN AND THE
POTENTIAL FOR FOG. THESE CONDITIONS IMPROVE FOR FRIDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...NORCROSS
LONG TERM...FITZSIMMONS
AVIATION...CB/HEWITT/NORCROSS
MARINE...CB/HEWITT/NORCROSS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1238 PM EDT SAT APR 26 2014
.SYNOPSIS...
MOISTURE STARVED COLD FRONT CROSSES TODAY...WITH AN ISOLATED
SHOWER OR THUNDERSTORM POSSIBLE SOUTH OF THE MASON DIXON LINE.
SUNDAY SHOULD BE DRY BEFORE AN UNSETTLED PATTERN SETS UP FOR THE
WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT IS SLOWLY SAGGING TOWARDS THE FORECAST AREA EARLY THIS
AFTERNOON. JUST AHEAD OF IT...STRONG MIXING WITH THE TIGHTENING
PRESSURE GRADIENT HAS HAS ALLOWED FOR A SURGE IN TEMPERATURES.
HAVE UPPED HIGH TEMPERATURES FOR AREAS SOUTH OF THE FRONT THROUGH
THE AFTERNOON BUT CLOUDS MAY BE A LIMITING FACTOR FOR THE COUNTIES
SOUTH OF THE MASON-DIXON LINE. GUSTY WINDS WILL CONTINUE INTO THE
EVENING AS THE COLD FRONT CROSSES THE REGION. IN
ADDITION...ANOTHER ROUND OF SHOWERS AND AN ISOLATED THUNDERSTORM
CANNOT BE RULED OUT WHERE MOISTURE REMAINS SOUTH OF I-70. WILL
CONTINUE TO CARRY POPS THERE AS THE HRRR SUGGESTS REDEVELOPMENT
THIS AFTERNOON.
CLEARING SKIES AND LIGHT WINDS SHOULD ALLOW FOR TEMPERATURES TO
FALL BELOW SEASONAL NORMALS OVERNIGHT. SOME MID-HIGH CLOUDS MAY
LINGER OVER OUR FAR SOUTHERN ZONES WHERE THE COLD FRONT STALLS
TONIGHT...BEFORE IT LIFTS AS A WARM FRONT TOMORROW.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY IS CURRENTLY THE ONLY DAY IN THE 7 DAY FORECAST WITHOUT A
CHANCE OF RAIN IN THE FORECAST THANKS TO HIGH PRESSURE BRIEFLY
PASSING OVER THE REGION. LOW PRESSURE WILL BEGIN TO DEVELOP IN THE
PLAINS...AND THE ASSOCIATED WARM FRONT WILL SWEEP TOWARDS THE REGION
ON MONDAY. RAIN IS EXPECTED TO WORK ITS WAY INTO EASTERN OHIO ON
MONDAY...AND ACROSS THE ENTIRE FORECAST AREA MONDAY NIGHT. DAYTIME
HIGHS WILL BE NEAR NORMAL...WITH OVERNIGHT LOWS ABOVE NORMAL AS
CLOUDS MOVE IN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
MODELS IN AGREEMENT ON A BROAD AREA OF LOW PRESSURE LINGERING OVER
THE ERN CONUS CENTERED IN THE GREAT LAKES THROUGH THE END OF NEXT
WEEK. THIS WILL PROVIDE DAILY CHANCES OF RAIN SHOWERS AND WORK TO
MODERATE TEMPERATURES UNDER CLOUDY SKIES. WITH A BLOCKED PATTERN
ALOFT DOUBT UPPER LEVEL SYSTEM WILL BE QUICK TO MOVE OFF FOR THE
WEEKEND...WITH COOL TEMPERATURES AND SHOWER CHANCES CONTINUED FOR
SATURDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR THROUGH THE TAF PERIOD AS A MOISTURE STARVED FRONT WORKS
ACROSS REGION THIS AFTERNOON. WINDS WILL BE GUSTY TO 25 KTS FROM
THE WEST TURNING NORTHWEST 18-22Z WITH MAIN FROPA. WINDS WILL
DIMINISH TOWARD SUNSET WITH VFR AND LIGHT NORTHERLY FLOW THROUGH
SUNDAY.
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
PERIODIC RSTRNS ARE EXPD MUCH OF NXT WK AS A SERIES OF DISTURBANCES
CROSS THE RGN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1133 AM EDT SAT APR 26 2014
.SYNOPSIS...
SCATTERED SHOWERS ARE EXPECTED TODAY...WITH AN ISOLATED THUNDERSTORM
POSSIBLE SOUTH OF THE MASON DIXON LINE. SUNDAY SHOULD BE DRY BEFORE
AN UNSETTLED PATTERN SETS UP FOR THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHOWERS ASSOCIATED WITH A WEAK SHORTWAVE CONTINUE TO SLIDE ACROSS
THE REGION THIS MORNING. THE HRRR SEEMED TO HANDLE THE RESOLUTION
OF THESE SHOWERS WELL...SO POPS WERE ADJUSTED THROUGH THE AFTERNOON
TO REFLECT THIS FORECAST. EXPECT THE GREATEST COVERAGE TO REMAIN
SOUTH OF I-70 FOR THE REST OF THE DAY AS A COLD FRONT SINKS
SOUTHWARD FROM LAKE ERIE. BUFKIT SOUNDINGS SUGGEST THAT THERE COULD
BE ENOUGH INSTABILITY WITH HEATING TO SUPPORT A THUNDERSTORM OR
TWO WITH THE LIFT FROM THE COLD FRONT SO MAINTAINED THE ISOLATED
THUNDER MENTION. EXPECT GUSTY WINDS WITH THE FRONTAL PASSAGE THIS
AFTERNOON...WEAKENING AFTER SUNSET. TEMPERATURES WILL BE
SEASONABLE DURING THE DAY...BUT BELOW NORMAL TONIGHT WITH LIGHT
WINDS AND CLEARING SKIES.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY IS CURRENTLY THE ONLY DAY IN THE 7 DAY FORECAST WITHOUT A
CHANCE OF RAIN IN THE FORECAST THANKS TO HIGH PRESSURE BRIEFLY
PASSING OVER THE REGION. LOW PRESSURE WILL BEGIN TO DEVELOP IN THE
PLAINS...AND THE ASSOCIATED WARM FRONT WILL SWEEP TOWARDS THE REGION
ON MONDAY. RAIN IS EXPECTED TO WORK ITS WAY INTO EASTERN OHIO ON
MONDAY...AND ACROSS THE ENTIRE FORECAST AREA MONDAY NIGHT. DAYTIME
HIGHS WILL BE NEAR NORMAL...WITH OVERNIGHT LOWS ABOVE NORMAL AS
CLOUDS MOVE IN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MODELS IN
AGREEMENT ON A BROAD AREA OF LOW PRESSURE LINGERING OVER THE ERN
CONUS CENTERED IN THE GREAT LAKES THROUGH THE END OF NEXT WEEK.
THIS WILL PROVIDE DAILY CHANCES OF RAIN SHOWERS AND WORK TO
MODERATE TEMPERATURES UNDER CLOUDY SKIES. WITH A BLOCKED PATTERN
ALOFT DOUBT UPPER LEVEL SYSTEM WILL BE QUICK TO MOVE OFF FOR THE
WEEKEND...WITH COOL TEMPERATURES AND SHOWER CHANCES CONTINUED FOR
SATURDAY.
&&
.AVIATION /16Z SATURDAY THROUGH THURSDAY/...
VFR THROUGH THE TAF PERIOD AS A MOISTURE STARVED FRONT WORKS
ACROSS REGION THIS AFTERNOON. WINDS WILL BE GUSTY TO 25 KTS FROM
THE WEST TURNING NORTHWEST 18-22Z WITH MAIN FROPA. WINDS WILL
DIMINISH TOWARD SUNSET WITH VFR AND LIGHT NORTHERLY FLOW THROUGH
SUNDAY.
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
PERIODIC RSTRNS ARE EXPD MUCH OF NXT WK AS A SERIES OF DISTURBANCES
CROSS THE RGN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS BALTIMORE MD/WASHINGTON DC
1008 AM EDT SAT APR 26 2014
.SYNOPSIS...
ANOTHER COLD FRONT WILL PASS THROUGH THE AREA LATER TODAY BEFORE
HIGH PRESSURE RETURNS SUNDAY. LOW PRESSURE WILL DEVELOP OVER THE
CENTRAL UNITED STATES EARLY NEXT WEEK. THIS WILL LIKELY BRING
CLOUDY...RAINY...AND COOL CONDITIONS TO THE REGION.
&&
.NEAR TERM /THROUGH SUNDAY/...
PART ONE OF THE UPPER LEVEL LOW PRES SYSTEM MOVED THROUGH
YESTERDAY...W/ A BIGGER BUILD-UP TO A LARGER SECTION OF PRECIP
ALONG W/ THE MAIN SYNOPTIC SYSTEM. PART TWO TODAY WILL BE THE
BACK-END LESSER POTENT PASSAGE OF A MINOR SHORTWAVE. THIS FEATURE
WILL ALSO DEVELOP A SFC LOW PRES SYSTEM...BUT VERY WEAK AND SMALL
IN SCALE. THE SFC LOW WILL BE SWINGING CLOSER TO THE NYC METRO
AREA...DRAGGING THE WEAK SFC COLD FRONT ACROSS OUR PORTION OF THE
MID ATLC REGION...BACK INTO THE CNTRL APLCNS. THE TAILEND OF THIS
FEATURE IS ALREADY KICKING-OFF SOME SCATTERED SHOWERS OVER
CNTRL/ERN OH AND SOME BANKING INTO THE WINDWARD SIDE OF THE
APLCNS.
PLENTY OF WIND UPSTAIRS BUT IT`S NOT BEING MIXED DOWN QUITE
YET. RELATIVELY LOW DEWPOINTS WILL ALLOW TEMPS TO QUICKLY SHOOT
BACK UP INTO THE 50S/60S THRU THE REST OF THE MRNG HRS. BY THE
MID-LATE AFTN...WE`LL SEE WIDESPREAD 70S AND A FEW U70S OVER THE
SRN TIER OF THE CWA/LOWER VA PIEDMONT. ONCE WLY WINDS START TO
PICK UP LATER THIS MRNG/EARLY AFTN...THE STRONGER WINDS WILL THE
DOWNSLOPING AND THEREFORE THE WARMING PROCESS - AND BRING TEMPS
UP A FEW MORE DEG THAN THE SYNOPTIC ALLOWANCE.
PLENTY OF DRY AIR OVERHEAD...W/ SOME OF THE BOUNDARY LAYER
EXPECTED TO CLOSE THAT GAP HEADING INTO THE AFTN HRS BUT STILL THE
ENVIRONMENT LENDS TO LOCALIZED DOWNBURSTS OF A PORTION OF THE
LL 50-70KT JET. THE AMBIENT WINDS THIS AFTN DURING THE PEAK
HEATING HRS WILL BE GUSTY...WELL INTO THE 20-30MPH RANGE W/ A FEW
GUSTS NEAR 40MPH. THE MAIN CONCERN WILL BE W/ THE FAST-MOVING
SHOWER...THAT COULD HELP PULL DOWN LOCALLY STRONGER GUSTS. THESE
SHOWERS DON`T EVEN NEED TO BE TSTMS...JUST WEAKLY CONVECTIVELY
INDUCED TO TAP INTO THE MID/BOUNDARY LAYER WINDS.
PRECIP ACTIVITY FOR THE AREA WILL BE RELATIVELY BRIEF IN TERMS OF
THE ENTIRE DAY AND ISOLATED. A COUPLE OF WAVES OF ISOLATED TO
SCATTERED SHOWERS WILL LIKELY SWING THRU THE CWA ALONG A NW-SE
TREK...SOME LOCAL MODELS LIKE THE RECENT WRF AND HRRR RUNS
BRINGING AT LEAST ONE WAVE OVER DC AND BALT REGIONS LATER THIS
AFTN.
PREV DISC...
THE WAVE WILL EXIT THE AREA THIS EVENING AND HIGH PRESSURE WILL
REBUILD SATURDAY NIGHT AND SUNDAY. A CHILLY NIGHT SATURDAY NIGHT
IN THE 40/S IS EXPECTED...AND HIGH TEMPERATURES SUNDAY WILL BE A
BIT BELOW NORMAL IN THE 60/S. SUNDAY WILL BE DRY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
SFC RDG AXIS WL BE ATOP CWFA SUN NGT...WHILE THE UPR RDG SHUD BE
POSITIONED ACRS THE GRTLKS/OHVLY/SRN APLCNS. THEREFORE...FAIR WX
SHUD PREVAIL...BUT THERE WL STILL BE ITEMS TO ADDRESS. MOST
NOTABLY WL BE THE INCRS IN CLDS IN ASSOC W/ H8 WAA. AM KEEPING
MIN-T A BIT ABV THE MOS MEAN AS A RSLT.
THE WMFNT CROSSES CWFA MON...PROVIDING MDT-STRONG ISENT LIFT. GDNC
SUGGESTING THERE WL BE A 30-40 KT LLJ PRESENT...BUT ARE AT ODDS ON
EXACTLY WHERE TO PLACE IT. REGARDLESS...THINK THERE WL BE ENUF UVV
TO SUPPORT DVLPG RA...AND AM FEATURING AN UPTICK IN POPS NOT JUST
DURING THE DAY...BUT ALSO MON NGT. ONCE AGN...GDNC TIMING WM FROPA A
BIT DIFFERENTLY...WHICH WL AFFECT THE TIME FRAME WHEN THE MOST SGFNT
RAFL WL OCCUR. EITHER WAY...MON WL MARK THE START OF A WET PD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE MIDDLE OF THE WEEK WILL BE RATHER SOGGY AND COOL. LOW PRESSURE
OVER THE GREAT PLAINS WILL APPROACH THE AREA FOR THE MIDDLE OF
NEXT WEEK. OVERCAST CONDITIONS SHOULD PERSIST THROUGHOUT THE DAY
ON TUES IN MOIST ONSHORE LOW LEVEL FLOW. WEAK COLD AIR DAMMING
COULD ALSO OCCUR...HELPING TO KEEP HIGH TEMPS IN THE MID 50S FOR
MOST OF THE AREA...ABOUT 15 DEG BELOW NORMAL FOR THIS TIME OF
YEAR. A WARM FRONT WILL CROSS THE AREA FROM SOUTH TO NORTH
BEGINNING TUESDAY AFTERNOON. THIS WARM FRONT WILL INITIALLY
OVERRUN COOLER AIR AT THE SURFACE AND SHOULD BRING SHOWERS TO THE
AREA THROUGHOUT THE DAY TUES.
SHOWERS REMAIN LIKELY THROUGH THE DAY ON WEDNESDAY AS A SERIES OF
WEAK DISTURBANCES PASS OVER THE AREA AND WARM MOIST AIR CONTINUES
TO FILL IN ON THE BACK OF SOUTHEASTERLY FLOW IN THE LOWER LEVELS.
THE LOW WILL STALL OVER THE GREAT LAKES WED NIGHT AND THURS AND THE
ASSOCIATED COLD FRONT WILL BEGIN TO APPROACH THE AREA WED EVENING.
GUIDANCE IS CURRENTLY SHOWING WEAK TO MODERATE INSTABILITY FOCUSED
OVER THE SOUTHERN PORTION OF THE CWA AHEAD OF THE FRONT WEDNESDAY
NIGHT AND TUES MORNING...THUS HAVE PUT ISOLATED THUNDERSTORMS ALONG
WITH LIKELY RAIN SHOWERS IN THE FORECAST FOR THIS TIME PERIOD
GENERALLY SOUTH OF A LINE FROM PENDLETON CO WV TO CALVERT CO MD.
HIGH PRESSURE WILL BEGIN TO FILL BACK INTO THE AREA BEHIND THE COLD
FRONT OVERNIGHT THURS AND FRI SHOULD ALLOW FOR US TO START DRYING
OUT UNDER MOSTLY SUNNY SKIES AND TEMPS NEAR 70.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS THRU THE TAF PERIOD. THE MAIN CONCERNS FROM THE
GUSTY SFC WINDS FROM LATE THIS MRNG INTO EARLY AFTN. WDLY SCT
-SHRA SPREADING FROM HGR TO IAD/DCA/BWI AFTER 18Z. TS POSSIBLE CB
TOPS FL380 SFC WIND G30KT 21Z- 00Z. VFR AFTER 00Z SUNDAY. RA
OVERSPREADING TERMINALS MON. VFR SHUD HOLD UP FOR THE MRNG
PUSH...THEN FLGT CAT DROPPING THRU MVFR. SUSPECT IFR WONT ARRIVE
TIL AFDK. IFR CONDITIONS ARE LIKELY IN LOW CEILINGS AND RAIN
SHOWERS AS A WARM FRONT SLOWLY CROSSES THE AREA TUESDAY AND INTO
WEDNESDAY.
&&
.MARINE...
STRONG MIXING WITHIN THE NEXT COUPLE HRS WILL ALLOW FOR GUSTS TO
CONTINUE INTO THE 20-25 MPH RANGE. SMALL CRAFT ADVISORIES WILL
CONTINUE INTO THE AFTERNOON. A GALE WARNING MAY BE WARRANTED IN
THE AFTERNOON AS CONVECTIVE SHOWERS MAY PRODUCE SMALL HAIL AND
STRONG WIND GUSTS. SCA HAS BEEN EXTENDED INTO SAT NGT AS HIGH PRES
BUILDS INTO THE AREA. SUN LOOKS TO HAVE LESS WIND. RDG AXIS SHUD
PROVIDE WNDS AOB 10 KT THRU MON. DIRECTION MAINLY NE VEERING SE AS
A WMFNT CROSSES THE WATERS. WNDS CUD BE CLSR TO 15 KT MON NGT MID
BAY/LWR PTMC...BUT MOMENTUM TRANSFER LOOKS QUITE POOR. A SMALL
CRAFT ADVISORY MAY BE NECESSARY FOR THE LOWER MARYLAND CHESAPEAKE
BAY IN SOUTHERLY FLOW TUESDAY NIGHT.
&&
.TIDES/COASTAL FLOODING...
ADVY FOR ANNAPOLIS EXPIRED...AND WATER BACK W/IN BANKS. LOOKS LIKE
STRONGER WINDS REACHED BALT AS XPCTD BASED ON FLATLINING OF
HYDROGRAPH. DC PEAKING JUST UNDER ADVY CRITERIA. NW FLOW SHUD
ASSIST IN RETURNING WATER LVLS TO NORMAL BY THE PM TIDE CYCLE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ530>543.
&&
$$
UPDATE...GMS
PREV DISCUSSION...SDG/HTS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
936 AM EDT SAT APR 26 2014
.SYNOPSIS...
SCATTERED SHOWERS ARE EXPECTED TODAY...WITH AN ISOLATED THUNDERSTORM
POSSIBLE SOUTH OF THE MASON DIXON LINE. SUNDAY SHOULD BE DRY BEFORE
AN UNSETTLED PATTERN SETS UP FOR THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHOWERS ASSOCIATED WITH A WEAK SHORTWAVE CONTINUE TO SLIDE ACROSS
THE REGION THIS MORNING. THE HRRR SEEMED TO HANDLE THE RESOLUTION
OF THESE SHOWERS WELL...SO POPS WERE ADJUSTED THROUGH THE AFTERNOON
TO REFLECT THIS FORECAST. EXPECT THE GREATEST COVERAGE TO REMAIN
SOUTH OF I-70 FOR THE REST OF THE DAY AS A COLD FRONT SINKS
SOUTHWARD FROM LAKE ERIE. BUFKIT SOUNDINGS SUGGEST THAT THERE COULD
BE ENOUGH INSTABILITY WITH HEATING TO SUPPORT A THUNDERSTORM OR
TWO WITH THE LIFT FROM THE COLD FRONT SO MAINTAINED THE ISOLATED
THUNDER MENTION. EXPECT GUSTY WINDS WITH THE FRONTAL PASSAGE THIS
AFTERNOON...WEAKENING AFTER SUNSET. TEMPERATURES WILL BE
SEASONABLE DURING THE DAY...BUT BELOW NORMAL TONIGHT WITH LIGHT
WINDS AND CLEARING SKIES.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY IS CURRENTLY THE ONLY DAY IN THE 7 DAY FORECAST WITHOUT A
CHANCE OF RAIN IN THE FORECAST THANKS TO HIGH PRESSURE BRIEFLY
PASSING OVER THE REGION. LOW PRESSURE WILL BEGIN TO DEVELOP IN THE
PLAINS...AND THE ASSOCIATED WARM FRONT WILL SWEEP TOWARDS THE REGION
ON MONDAY. RAIN IS EXPECTED TO WORK ITS WAY INTO EASTERN OHIO ON
MONDAY...AND ACROSS THE ENTIRE FORECAST AREA MONDAY NIGHT. DAYTIME
HIGHS WILL BE NEAR NORMAL...WITH OVERNIGHT LOWS ABOVE NORMAL AS
CLOUDS MOVE IN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
MODELS IN AGREEMENT ON A BROAD AREA OF LOW PRESSURE LINGERING OVER
THE ERN CONUS CENTERED IN THE GREAT LAKES THROUGH THE END OF NEXT WEEK.
THIS WILL PROVIDE DAILY CHANCES OF RAIN SHOWERS AND WORK TO
MODERATE TEMPERATURES UNDER CLOUDY SKIES.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
MID-LEVEL CLOUDS CONTINUE TO STREAM IN AHEAD OF ANOTHER WEAK COLD
FRONT TODAY. SPOTTY MVFR CONDITIONS FOR VISBY WILL QUICKLY GIVE
WAY TO VFR AS CLOUDS INCREASE. INCLUSION OF MARGINAL LLVL WIND SHEAR AS
20-30KT SOUTHWEST WINDS EXIST ABOUT 2KFT OFF THE DECK. THE
WEAK COLDFRONT TODAY WILL SPAWN MORE SCT SHOWERS AND MOSTLY VFR
STRATOCU ON THIS AFTERNOON WITH GUSTY WINDS.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
PERIODIC RSTRNS ARE EXPD ERLY NXT WK AS A SERIES OF DISTURBANCES
CROSS THE RGN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
715 PM EDT SUN APR 27 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 432 PM EDT SUN APR 27 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH THROUGH THE NW CONUS WITH A LOW OVER WRN KS AND A
DOWNSTREAM RIDGE FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA.
AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES
BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER NW KS. AN
INITIAL BAND OF LIGHT PCPN WAS PRODUCING MAINLY JUST SPRINKLES INTO
THE FAR WRN CWA NEAR IWD AS IT ENCOUNTERS THE VERY DRY LAYER BELOW
750 MB. HOWEVER...A MORE SUBSTANTIAL AREA OF RAIN OVER WRN INTO N
CNTRL WI...SUPPORTED BY 300K ISENTROPIC LIFT WAS LIFTING TOWARD
UPPER MI.
TONIGHT...RADAR TRENDS AND SHORT TERM MODELS SUGGEST THAT SOME LIGHT
SHOWERS WILL MOVE INTO THE WEST LATE THIS AFTERNOON AND EVENING.
HOWEVER...THERE IS A LOWER CHANCE THAT THERE WILL BE MEASURABLE PCPN
GIVEN THE AMOUNT OF DRY AIR TO OVERCOME WITH THE ERLY LOW LEVEL
INFLOW. FARTHER TO THE EAST...OVER S CNTRL UPPER MI...THE DRY
AIR...PER 12Z APX SOUNDING...SHOULD BE MORE EFFECTIVE AT SLOWING THE
ADVANCE AND REDUCING PCPN CHANCES. WITH EVAPORATIVE COOLING AT THE
LEADING EDGE OF THE PCPN...SOME SNOW OR SLEET MAY ALSO MIX IN WITH THE
RAIN LATE THIS EVENING AND OVERNIGHT...PER NAM LOW LEVEL THICKNESS
AND WET-BULB ZERO HEIGHTS.
MON...THE MODELS WERE IN SLIGHTLY BETTER AGREEMENT IN HANDLING THE
ADVANCE OF PCPN INTO UPPER MICHIGAN. THE NAM/GFS/ECMWF WERE NOW ON
THE SLOWER SIDE COMPARED TO GEM. AS THE MID/UPPER LEVEL LOW SLOWLY
WOBBLES TO THE NORTHEAST AND AN ELONGATED TROUGH/FRONT EXTENDS FROM
SRN IA INTO NRN INDIANA. ANOTHER BAND OF RAIN WILL MOVE TOWARD UPPER
MI WITH INCREASING 300K-305K ISENTROPIC ASCENT NORTH OF THE 850 MB
WARM FRONT THROUGH CNTRL WI. THERE IS STILL LIKELY TO BE SHARP
CUTOFF TO THE NRN EDGE OF THE PCPN BAND THROUGH CNTRL UPPER MI. THE
HIGHEST CHANCES WILL REMAIN ALONG THE WI BORDER WITH ONLY A SLIGHT
CHANCE OVER THE NORTH.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 432 PM EDT SUN APR 27 2014
UPPER LOW OVER THE CENTRAL PLAINS MONDAY AFTERNOON AND ASSOCIATED
SFC LOW AND WARM FRONT WILL BE MAIN FOCUS FOR THE FORECAST THIS
UPCOMING WEEK. MODELS VERY LOCKED INTO IDEA THAT WHILE WIDESPREAD
SHRA AND TSRA AND SEVERE WEATHER IMPACT MID TO LOWER MISSISSIPPI
RIVER VALLEY...ADDITIONAL SHRA/TSRA DEVELOP LATE MONDAY AFTN ALONG
WARM FRONT EXTENDING TO THE EAST OF SFC LOW OVER NEB. THIS IS IN
RESPONSE TO SHORTWAVE/PV ANAMOLY LIFTING AHEAD OF PARENT UPPER LOW.
POSSIBLE THAT ADDITIONAL SHRA WILL ALREADY BE LIFTING TOWARD UPR
MICHIGAN AS WELL DUE TO REMNANTS OF SHRA/TSRA DEVELOPING OVER THE
UPPER MISSISSIPPI RIVER VALLEY MONDAY MORNING PER SSW-NNE ORIENTED
FORWARD PROPAGATING CORFIDI VECTORS AND H85-H7 MOSITURE TRANSPORT.
AREA OF SHRA/TSRA ALONG WARM FRONT WILL GLIDE TOWARD UPR MICHIGAN
OVERNIGHT INTO TUESDAY MORNING DUE TO THE ARRIVAL OF SHORTWAVE AND
H85-H5 Q-VECTOR CONVERGENCE ALONG WITH VEERING H85-H7 FLOW FM ESE
TO MORE SSW. FOLLOWING THE Q-VECTOR CONVERGENCE AND RIBBON OF
MOISTURE TRANSPORT...EXPECT MOST PRECIPITATION TO OCCUR IN THE
MORNING. BASED ON 1000-850MB THICKNESSES/H85 TEMPS AND HEIGHT OF
WBZERO...MAY SEE SNOW OR A RAIN/SNOW MIX OVER HIGHER TERRAIN OF
WEST AND NCNTRL UPR MICHIGAN PERHAPS EVEN LINGERING INTO MID AFTN.
MINOR SNOW ACCUMULATIONS SEEM POSSIBLE...ESPECIALLY ON GRASSY
SURFACES. WILL LEAVE OUT OF HAZARDOUS WEATHER OUTLOOK FOR NOW AS
TRAVEL WOULD PROBABLY BE ONLY MINIMALLY IMPACTED. BY LATE
AFTN...EXPECT CHANGE OVER TO RAIN AS H85 TEMPS SURGE ABOVE ZERO.
THIS MAY BE OCCURRING WHEN MAJORITY OF HEAVIER PRECIPITATION IS
COMING TO AN END THOUGH. BY TUE EVENING...FORECAST SOUNDINGS SHOW
DRYING ABOVE H9...SO THERE MAY BE DRIZZLE. TEMPS WILL CONTINUE TO
RISE SFC-H85 SO BY THAT TIME WILL ONLY BE DEALING WITH LIQUID PRECIP.
ON WEDNESDAY...PRIMARY SHORTWAVE LIFTS NORTH ACROSS THE UPPER GREAT
LAKES. SEEMS TO BE A TREND FOR BEST MOISTURE TRANSPORT TO MISS UPR
MICHIGAN TO THE EAST...ALLOWING BULK OF RAIN ON WEDNESDAY TO SURGE
NORTH ACROSS THE LOWER LAKES. HOWEVER...SIGNAL THAT HIGHER THETA-E
AT H8-H7 WILL BE WRAPPING WESTWARD ACROSS UPR MICHIGAN ON CYCLONIC
NORTH SIDE OF FILLING SFC-H85 LOWS. RAIN ON WEDNESDAY WOULD ONLY BE
BOLSTERED OVER HIGHER TERRAIN OF WESTERN AND NORTH CENTRAL UPPER
MICHIGAN WITH NE BLYR WINDS. WEDNESDAY NIGHT INTO THURSDAY...THE
VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS NEARLY STATIONARY
OVER THE UPPER GREAT LAKES. UNSETTLED WEATHER PATTERN AND WILL KEEP
WITH THE CHANCES THAT CONSENSUS OF MODELS SHOWS. THE GREATEST
CHANCES OF RAIN WILL BE ALONG AND NORTH AND WEST OF H85 LOW WHERE
HIGHER THETA-E CONTINUES TO WRAP AROUND THE LOW AND ALSO WHERE
LINGERING Q-VECTOR CONVERGENCE IS LOCATED. YET...CANNOT RULE OUT
PRECIP JUST ABOUT ANYWHERE OVER THE CWA AS OTHER SHORTWAVES WILL
PROBABLY BE CYCLING AROUND THE MAIN UPPER LOW CENTER AND THERE
SHOULD BE PLENTY OF LOW-MID LEVEL MOISTURE REMAINING OVER REGION.
DO NOT EXPECT THE PRECIP THAT OCCURS BEYOND WEDNESDAY EVENING TO
BE HEAVY AS RICHER MOISTURE WILL BE HEADING WELL TO THE EAST OF
THE REGION BY THAT TIME. GRADUALLY COOLING TEMPERATURES ALOFT AND
EVENTUALLY AT THE SFC /H85 TEMPS DROPPING BLO 0C PER GFS/ECMWF/
COULD RESULT IN MIXED RAIN AND SNOW OVER PORTIONS OF CWA LATER
WEDNESDAY NIGHT INTO THURSDAY MORNING AND AGAIN THURSDAY NIGHT INTO
FRIDAY MORNING. MAY EVEN SEE MIX LATER FRIDAY NIGHT INTO SATURDAY
MORNING. ONLY SLIGHT CHANCES FOR POPS BY THAT TIME THOUGH AS
SYSTEM WILL BE UNRAVELLING AS IT LIFTS EAST AND NORTH AWAY FM LK
SUPERIOR/UPR MICHIGAN.
UPPER LEVEL TROUGH STILL FORECAST OVER THE REGION NEXT WEEKEND...SO
NO WARM UP IS IN STORE. COULD BE MORE RAIN/SNOW BY NEXT SUNDAY AS
THERE ARE HINTS OF STRONGER SYSTEM WORKING THROUGH AT THAT TIME.
HOWEVER...SINCE THE TIMING FOR THAT SYSTEM WILL BE COMPLETELY
DICTATED BY THE UPPER LOW THIS WEEK AND HOW QUICK IT DEPARTS...THERE
IS CONSIDERABLE UNCERTAINTY IN HOW ALL THESE DETAILS WILL EVENTUALLY
WORK OUT. THUS...CHANGES TO MODEL CONSENSUS BEYEOND THURSDAY WERE
MINIMAL GIVEN THE UNCERTAINTY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 715 PM EDT SUN APR 27 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. THERE COULD BE
SOME INTERMITTENT LIGHT RAIN AT KIWD THIS EVENING AS MID LEVELS
BEGIN TO MOISTEN...BUT CONDITIONS ARE EXPECTED TO REMAIN VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT SUN APR 27 2014
EAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER
THE PLAINS. EXPECT ENE GALES TO 35KTS OVER WESTERN LK SUPERIOR
TOWARD DULUTH INTO TUE MORNING. EAST GALES ARE THEN EXPECTED LATE
TONIGHT INTO MON OVER THE REST OF THE WESTERN LAKE. WINDS WILL
GRADUALLY DIMINISH TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE. WINDS ARE EXPECTED TO
DROP OFF TO 25 KNOTS OR LESS FROM WED INTO THU AS THE LOW FILLS AND
REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 432 PM EDT SUN APR 27 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS...AND THE STURGEON
RIVER NEAR NAHMA JUNCTION IN DELTA COUNTY. AT LEAST THROUGH MONDAY
NONE OF THESE RIVERS ARE EXPECTED TO REACH FLOOD STAGE...BUT THESE
AND OTHER RIVERS MAY START TO RISE AGAIN LATER THIS WEEK AS A LOW
PRESSURE SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN.
TOTAL LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2
INCHES BY LATE THIS WEEK. THE PRECIPITATION WOULD ADD TO THE FLOOD
RISK...ESPECIALLY OVER THE NORTHWEST HALF OF UPPER MICHIGAN WHERE
SNOWMELT WILL ALSO ADD TO THE RUNOFF.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 11 AM EDT /10 AM CDT/ TUESDAY FOR LSZ162.
GALE WARNING FROM 2 AM TO 8 PM EDT MONDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
422 PM EDT SAT APR 26 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 417 PM EDT SAT APR 26 2014
WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT MID/UPPER LEVEL FLOW
THROUGH THE NRN LAKES BETWEEN A TROUGH INTO THE NE CONUS AND A RIDGE
FROM THE MID MS VALLEY INTO THE NRN PLAINS SASK. AT THE SFC...A
RIDGE EXTENDED FROM HUDSON BAY INTO THE WRN GREAT LAKES RESULTING IN
N TO NE FLOW INTO UPPER MICHIGAN. VIS LOOP SHOWED A CLEARING TREND
WITH THE COMBINATION OF DRY ADVECTION AND DAYTIME MIXING HELPING TO
SCOUR OUT THE LOW CLOUDS. AFTERNOON TEMPS RANGED FROM THE MID 30S
NORTH...DOWNWIND OF LAKE SUPERIOR...TO THE MID 40S OVER THE SOUTH.
TONIGHT...EVEN THOUGH THERE MAY BE SOME INCREASE IN HIGH CLOUDS
OVERNIGHT AND SOME LIGHT EAST WINDS...EXPECT RADIATIONAL
COOLING CONDITIONS WILL BE FAVORABLE ENOUGH TO ALLOW TEMPS TO DROP
TOWARD THE LOWER 20S INLAND NORTH AND TO AROUND 30 NEAR THE WI
BORDER.
SUN...AS THE STRONG MID LEVEL AND SFC LOW MOVE INTO THE CNTRL PLAINS
WAA PCPN AHEAD OF THE 850 MB WARM FRONT MAY APPROACH UPPER MI AS IT
SPREADS THROUGH WI. HOWEVER...WITH PERSISTENT ERLY LOW LEVEL DRY
ADVECTION AND THE VERY DRY PROFILE BELOW 750 MB...PER FCST
SOUNDINGS...EXPECT THAT THE PCPN WILL STAY TO THE SOUTH OF THE CWA.
TEMPS WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE MID 40S TO AROUND
50 OVER MUCH OF UPPER MICHIGAN. HOWEVER...OVER N CNTRL UPPER MI AND
THE KEWEENAW...THE EAST WIND OFF OF LAKE SUPERIOR WILL KEEP HIGHS
FROM AROUND 40 TO 45.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 417 PM EDT SAT APR 26 2014
UPPER LOW BEGINS THE LONG TERM PERIOD LUMBERING OUT OF THE SOUTHWEST
CONUS ACROSS THE CENTRAL PLAINS. SFC LOW NEARBY THE UPPER LOW CENTER
WHILE HIGH PRESSURE RIDGE EXTENDS SOUTHWARD FROM HUDSON BAY TO THE
GREAT LAKES. UPPER LOW AND ASSOCIATED BLOCKING ALOFT ON ITS EDGES
WILL BE MAIN WEATHER INSTIGATORS FOR THE UPCOMING WEEK. IT SEEMS TO
ALWAYS BE A STRUGGLE FOR THE MODELS WITH THIS TYPE OF SITUATION WHERE
THE UPPER LOW AND ASSOCIATED MOISTURE TRANSPORT RUN INTO THE SFC HIGH
AND DRY LOW-LEVEL AIR. MOISTURE ADVECTION ALOFT COULD ALLOW FOR A LOT
OF MID CLOUDS AND PERHAPS SOME LGT RAIN OVER THE SOUTHERN CWA MONDAY
AFTN INTO MONDAY EVENING. FARTHER NORTH...THINK LOWER SFC-H85 RH OUT
OF THE HUDSON BAY HIGH WILL LIMIT ANY PRECIP TO ISOLD SHOWERS OR
SPRINKLES. EAST-NORTHEAST WINDS WILL KEEP LK SUPERIOR AREAS IN THE
LOWER 40S ON MONDAY...BUT INLAND AREAS CLOSER TO WI BORDER AND OVER
THE EASTERN CWA MAY BE ABLE TO PUSH INTO THE 50S WITH BETTER MIXING
HEIGHTS UP TO H85. POSSIBLE THAT MID 50S COULD OCCUR OVER FAR EAST IF
CLOUDS HOLD OFF LONG ENOUGH.
ENOUGH CONFIDENCE THAT ONCE TUESDAY AND WEDNESDAY ARRIVE...UPPER LOW
WILL BE EXERTING ENOUGH OF AN INFLUENCE TO RESULT IN PRECIPITATION
ACROSS THE CWA. EAST WINDS WITH CLOUDS AND PRECIP WILL KEEP TEMPS IN
ALL AREAS WELL BLO NORMAL...WITH HIGHS THIS PERIOD UPR 30S TO LOW
40S NEAR LK SUPERIOR AND MAINLY IN THE 40S INLAND. AS IT APPEARS
NOW...AND THIS IS SUBJECT TO CHANGE...SEEMS THAT PRECIPITATION COMES
IN TWO WAVES. FIRST MAIN AREA OF PRECIPITATION SUPPORTED BY INITIAL
SHORTWAVES ROTATING AROUND THE UPR LOW AND H85-H7 MOISTURE TRANSPORT
LIFTS ACROSS THE CWA ON TUESDAY. GFS AND ECMWF SUGGESTS STEADIER
PRECIP COULD CHANGE TO MAINLY DRIZZLE TUESDAY AFTN INTO TUESDAY
EVENING. PTYPE COULD BE AN ISSUE INITIALLY AS H85 TEMPS BLO ZERO OVER
THE WESTERN CWA AND SFC TEMPS IN THE LOW-MID 30S MONDAY NIGHT INTO
TUESDAY MORNING POINT TO POSSIBLE RAIN/SNOW MIX. 1000-850MB
THICKNESSES RIGHT ON THE 1300-1305M LINE WOULD INDICATE DIFFERENCE
BTWN SEEING RAIN...SNOW...OR A MIX WILL BE DEPENDANT ON ELEVATION
HEIGHT. THERE IS NOT A LOT OF PRECIP EXPECTED MOST OF MONDAY NIGHT
FOR AREAS IN THE RAIN/SNOW ZONE...BUT PRECIP TUESDAY MORNING COULD BE
MORE IMPACTED. WOULD NOT BE SURPRISED TO SEE SLUSHY SNOW ACCUMS ON
TUESDAY MORNING OVER THE HIGHER TERRAIN OF THE NORTHWEST AND NORTH
CENTRAL CWA. ANY MIX WOULD CHANGE TO RAIN IN THE AFTN AS RELATIVELY
WARMER AIR ARRIVES FROM THE SOUTH.
KEPT RAIN CHANCES FOR TUESDAY NIGHT BUT IT COULD BE DRIZZLE AT
TIMES. BEST CHANCE OF RAIN OVER THE EASTERN CWA AHEAD OF STRONGER
SHORTWAVE LIFTING IN LATER TUESDAY NIGHT. SHORTWAVE LIFTS ACROSS
AREA ON WEDNESDAY WHICH IS ALSO WHEN MAIN SFC LOW ARRIVES OVER THE
REGION. EVEN THOUGH BETTER MOISTURE TRANSPORT IS HEADING EAST BY
THAT TIME...THERE IS HINT OF WARM AND MOIST AIR WRAPPING BACK ACROSS
UPR LAKES AS THE SFC LOW BEGINS TO OCCLUDE. KIND OF EARLY TO BE
LOOKING AT TROWAL SPECIFICS BUT THAT MAY BE WHAT MODELS ARE KEYING
ON TO BOOST QPF TOTALS ALONG TRACK OF H85 LOW TRACK. UPSLOPE NNW
FLOW MAY ALSO INCREASE TOTALS OVER WEST AND NCNTRL LATER WEDNESDAY
INTO WEDNESDAY NIGHT. STILL APPEARS THAT TOTAL PRECIP TUESDAY AND
WEDNESDAY...AT LEAST IN SOME AREAS...MAY REACH 1 TO 1.5 INCHES.
LATER WEDNESDAY NIGHT INTO THURSDAY MAY HAVE TO DEAL WITH MORE PTYPE
ISSUES AGAIN AS VERTICALLY STACKED LOW PRESSURE ALLOWS FOR GRADUALLY
COOLING TEMPERATURES JUST ABOVE SFC. H85 TEMPS DROP BACK BLO 0C SO
COULD SEE MORE RAIN AND SNOW MIX FOR THE WEST HALF OF CWA WEDNESDAY
NIGHT INTO THURSDAY MORNING. UNRAVELLING UPPER/SFC LOWS ONLY SLOWLY
MOVE OUT OF THE AREA LATE THIS WEEK. ADDITIONAL SHORTWAVES MAY BRING
MORE UNSETTLED WEATHER FRIDAY INTO SATURDAY /BOTH RAIN AND SNOW
POSSIBLE/...BUT GRADUALLY POPS WILL DROP BACK TO SLIGHT CHANCES BY
THAT TIME. CONSENSUS MAX TEMPS CONTINUING TO STAY BLO NORMAL ARE NOT
NECESSARILY DESIRED...BUT APPEAR REASONABLE TO CLOSE THE LONG TERM
PERIOD. MADE FEW CHANGES TO CONSENSUS TEMPS/POPS/WINDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 148 PM EDT SAT APR 26 2014
AS DRIER AIR MOVES IN FROM THE NORTH AND DAYTIME MIXING
CONTINUES...EXPECT MVFR CIGS TO GIVE WAY TO VFR CONDITIONS BY MID TO
LATE AFTERNOON. VFR CONDITIONS WILL THEN PREVAIL THROUGH THE REST OF
THE TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT SAT APR 26 2014
EAST WINDS INCREASE ON SUNDAY INTO SUNDAY NIGHT AS LOW
PRESSURE DEEPENS OVER THE PLAINS. GUSTS COULD REACH GALE FORCE TO
35KTS OVER FAR WESTERN LK SUPERIOR TOWARD DULUTH BY LATE AFTERNOON.
EAST GALES ARE THEN EXPECTED SUN NIGHT INTO MON OVER THE WEST.
WINDS WILL GRADUALLY DIMINISH MON NIGHT INTO TUE AS THE LOW PRESSURE
SYSTEM LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES
GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED INTO
TUE. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED
INTO THU AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 417 PM EDT SAT APR 26 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER
NEAR NAHMA JUNCTION. WHILE THE PAINT RIVER NEAR CRYSTAL FALLS AND
THE STURGEON RIVER NEAR NAHMA JUNCTION ARE NOT EXPECTED TO REACH
FLOOD STAGE IN THE SHORT TERM...THE STURGEON RIVER NEAR CHASSELL
REMAINS NEAR FLOOD STAGE AND IS EXPECTED TO REMAIN STEADY FOR THE
REST OF THE WEEKEND.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
A LARGE LOW PRESSURE SYSTEM WILL MOVE INTO THE GREAT LAKES BY THE
MIDDLE OF NEXT WEEK. PERIODS OF RAIN ARE POSSIBLE FROM LATE MONDAY
THROUGH THURSDAY WITH THE POTENTIAL FOR TOTAL AMOUNTS OF AN INCH TO
AN INCH AND A HALF. THIS WOULD ADD TO THE FLOOD RISK...ESPECIALLY
OVER THE NORTHWEST HALF OF UPPER MICHIGAN WHERE SNOWMELT WILL ALSO
ADD TO THE RUNOFF.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS OVER THE NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY EVENING FOR
LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLB
HYDROLOGY...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1025 AM CDT SAT APR 26 2014
.UPDATE...SUNNY SKIES PREVAIL THIS MORNING ACROSS THE ARKLAMISS.
TEMPERATURES LATE THIS MORNING WERE MAINLY IN THE LOW TO MID
70S...WITH AFTERNOON HIGHS EXPECTED TO REACH THE MID 80S. AS FOR THE
CURRENT FORECAST...WENT AHEAD AND ADDED A MENTION OF THUNDER TO THE
SHOWER ACTIVITY FOR LATER THIS AFTERNOON ALONG AND SOUTH OF THE I20
CORRIDOR DUE TO SOME ELEVATED INSTABILITY. ONLY OTHER CHANGE WAS TO
MAKE SOME SLIGHT ADJUSTMENTS TO THE CLOUD COVER FOR THIS MORNING INTO
THE EARLY AFTERNOON HOURS. /27/
&&
.AVIATION...CLEAR SKIES WERE BEING OBSERVED AT 15Z. THE STALLED
BOUNDARY JUST SOUTH OF HBG WILL BEGIN LIFTING NORTH THIS AFTN. THIS
WL BRING AN INCREASE IN CLOUD COVER AND A SLIGHT CHANCE OF A SHOWER
OT TSTM...ALONG AND SOUTH OF INTERSTATE 20. OTHERWISE...VFR
CONDITIONS WL CONTINUE THROUGH THIS EVENING. WIDESPREAD IFR CATEGORY
STRATUS IS EXPECTED TO SPREAD NORTH ACROSS THE FORECAST AREA TOWARD
10Z SUNDAY. TSTM POTENTIAL WILL BE ON THE INCREASE SUNDAY INTO
SUNDAY NIGHT AS A POTENT LOW PRESSURE SYSTEM APPROACHES. THIS LOW
PRESSURE SYSTEM WL TAKE UNTIL WEDNESDAY TO SHIFT EAST OF OUR AREA
RESULTING IN A STRETCH OF ROUGH WEATHER FOR AVIATION INTERESTS SUN
THROUGH TUESDAY. /EC/22/
&&
.PREV DISCUSSION... /ISSUED 513 AM CDT SAT APR 26 2014/
..SEVERE WEATHER OUTBREAK EXPECTED FROM SUNDAY NIGHT THROUGH
TUESDAY AND SIGNIFICANT FLOOD EVENT POSSIBLE AS WELL...
DISCUSSION...
TODAY AND TONIGHT...
THERE IS A WRINKLE IN WHAT WAS SUPPOSED TO CLEARLY BE A DRY FORECAST
FOR SATURDAY. THE NCEP WRF AND HRRR GUIDANCE SUGGEST AN EAST-WEST
ORIENTED BROKEN LINE OF SHOWERS MAY DEVELOP LATER TODAY WITH DAYTIME
HEATING ALONG THE NORTHERN EDGE OF RICHER LOW LEVEL MOISTURE NEAR THE
GULF COAST. HAVE RAISED POPS TO SLIGHT CHANCE CATEGORY FOR LOCATIONS
ALONG AND SOUTH OF I-20. CONFIDENCE IS LOW IN THIS ACTIVITY
MATERIALIZING GIVEN THE DRY AIR (PRECIPITABLE WATER < .50 INCH) THAT
NEEDS TO BE OVERCOME AND GENERAL LACK OF LIFT ON ANY SCALE. EXPECT
ANY SHOWER ACTIVITY TO DIMINISH QUICKLY WITH SUNSET THIS
EVENING. OTHERWISE...EXPECT INCREASING LOW CLOUDS AS HIGHER QUALITY
BOUNDARY LAYER MOISTURE BEGINS TO SURGE INLAND.
SUNDAY THROUGH MONDAY NIGHT...
HIGH FORECAST CONFIDENCE CONTINUES REGARDING A DANGEROUS SET-UP FOR
SEVERE WEATHER AND HEAVY RAINFALL FROM LATE SUNDAY THROUGH TUESDAY
NIGHT. ALL MODES OF SEVERE WEATHER INCLUDING THE POTENTIAL FOR STRONG
TORNADOES WILL BE POSSIBLE AS A LARGE AND DEEP VORTEX LOCKS IN OVER
THE CENTRAL CONUS AND SENDS SEVERAL LOBES OF SHORTWAVE TROUGH ENERGY
ACROSS THE ARKLAMISS. GIVEN THE PERSISTENCE OF THIS PATTERN AND
AVAILABILITY OF ANOMALOUS MOISTURE...A SIGNIFICANT FLOODING EVENT IS
PROBABLE AS WELL.
THE RISK FOR SEVERE WEATHER COULD RAMP UP QUICKLY LATE SUNDAY
AFTERNOON INTO THE EVENING IN THE DELTA REGION. GUIDANCE CONTINUES
TO INDICATE THAT RAPID MOISTENING AND DESTABILIZATION ASSOCIATED
WITH INCREASINGLY CYCLONIC FLOW ALOFT WILL ALLOW FOR SHOWER/THUNDERSTORM
ACTIVITY TO BREAK OUT AS EARLY AS SUNDAY MORNING. BY SUNDAY AFTERNOON
AND EVENING A VERY UNSTABLE (ML CAPE > 2500 J/KG) AND HIGHLY SHEARED
ENVIRONMENT (0-1KM ~45 KTS) IS EXPECTED AS LAPSE RATES STEEPEN ABOVE
A STRENGTHENING LOW LEVEL JET (50-60KTS). LARGE CLOCKWISE HODOGRAPHS
WILL SUPPORT SUPERCELL THUNDERSTORMS WITH INTENSE ROTATING UPDRAFTS
AND STRONG TORNADO POTENTIAL OVER THE DELTA REGION BY SUNDAY
EVENING. CONFIDENCE IS INCREASING THAT THE GREATER RISK FOR SEVERE
WEATHER WILL REMAIN MAINLY OVER THE DELTA REGION SUNDAY NIGHT. BUT
A QUASI-LINEAR CONVECTIVE SYSTEM COULD EVENTUALLY EVOLVE...AND IF
THIS HAPPENS WE WOULD EXPECT COLD POOL GENERATION TO HELP GIVE THE
SYSTEM SOME EASTWARD ACCELERATION ALONG THE HWY 82 CORRIDOR...PERHAPS
REACHING THE NATCHEZ TRACE CORRIDOR. IT IS UNCLEAR HOW MUCH SUCH AN
MCC WILL DIMINISH DURING THE EARLY MONDAY MORNING HOURS...BUT THERE
MAY BE SOMEWHAT OF A LULL BEFORE THE NEXT ROUND OF SHORTWAVE ENERGY
APPROACHES.
AS WE GO INTO MONDAY AFTERNOON AND EVENING...EXPECT RE-NEWED SEVERE
THUNDERSTORM ACTIVITY WHEN A RIBBON OF STRONGER PACIFIC JET ENERGY
ROUNDS THE BASE OF THE DEEP CENTRAL CONUS TROUGH AND ENHANCES WIND
SHEAR/LIFT AND THE SEVERE WEATHER RISK OVER THE FORECAST AREA. MIXED
LAYER CAPE NEAR 3000 J/KG COULD HELP MAKE FOR A VOLATILE SET-UP WITH
THIS SYNOPTIC PATTERN. THE INITIAL CONVECTION SHOULD EVENTUALLY
EVOLVE INTO ANOTHER LINEAR CONVECTIVE SYSTEM...AND WITH DEEP LAYER
SHEAR VECTORS BECOMING MORE PARALLEL RESULTING IN GREATER POTENTIAL
FOR TRAINING AND BACK-BUILDING OF STORMS...THE RISK FOR HEAVY
RAINFALL AND FLOODING COULD REALLY RAMP UP MONDAY NIGHT. THE ECMWF IS
A LITTLE MORE PROGRESSIVE WITH SUCH A SYSTEM WHILE THE GFS SHOWS A
GREATER PROPENSITY FOR PARALLEL DEEP LAYER FLOW AND CORFIDI VECTOR
RIDGING SUGGESTIVE OF MCS BACK-BUILDING AND SLOW SYSTEM SPEED. WHILE
IT IS DIFFICULT TO KNOW WHERE IT WILL SET UP EXACTLY...WITH K INDICES
IN THE LOW 40S AND PRECIPITABLE WATER APPROACHING 2 INCHES...THERE
WILL LIKELY BE INTENSE RAINFALL RATES OF WHICH ANY LONG DURATION
COULD LEAD TO SERIOUS FLOODING CONCERNS.
CIPS ANALOGS ARE STILL SHOWING VERY SIGNIFICANT EVENTS FOR COMPARISON
TO THIS SET-UP ADDING MORE CONFIDENCE THAT SIGNIFICANT SEVERE WEATHER
AND FLOODING WILL BE POSSIBLE. THE LATEST ANALOG CONSENSUS HAS
SHIFTED BACK A LITTLE FARTHER NORTH WITH HIGHER SEVERE WEATHER/HEAVY
RAINFALL PROBS FROM SUNDAY NIGHT THROUGH MONDAY NIGHT...BEFORE
SHIFTING SOUTHWARD FOR THE TIME CENTERED ON THE MORE UNCERTAIN
TUESDAY EVENING PERIOD. TO MAINTAIN CONSISTENCY WILL NOT MAKE ANY
SIGNIFICANT ADJUSTMENTS AT THIS POINT TO THE RISK AREAS...BUT WILL
ADD SOME MORE DETAIL. /EC/
TUESDAY THROUGH NEXT SATURDAY...
A VOLATILE PATTERN SUPPORTIVE OF SEVERE WEATHER/TORNADOES AND
ADDITIONAL HEAVY RAIN MAY CONTINUE TUESDAY INTO TUESDAY NIGHT. THE
FORECAST FOR THIS PERIOD IS MORE UNCERTAIN HOWEVER AS IT WILL HINGE
GREATLY ON THE BEHAVIOR OF MONDAY NIGHT CONVECTIVE ACTIVITY. A
STRONG CLOSED H5 CLOSED LOW WILL EXIST OVER IOWA EARLY TUESDAY WHICH
IS CHARACTERIZED BY A 120KT CYCLONICALLY CURVED JET WITH MULTIPLE
EJECTING LOBES OVERTOP A MOIST UNSTABLE MODERATELY SHEARED
ENVIRONMENT ACROSS THE ARKLAMISS. THIS SET-UP WILL SUPPORT VIGOROUS
CONVECTIVE DEVELOPMENT AGAIN FOR TUESDAY AFTERNOON AND EVENING.
ADDITIONAL HEAVY RAIN WILL BE POSSIBLE WITH PRECIPITABLE WATER
AROUND 1.8 INCHES AND FAVORABLE WIND PROFILES FOR TRAINING OF STORMS
LEADING TO FLASH FLOODING AND SIGNIFICANT RIVER RISES. THE ASSOCIATED
COLD FRONT WILL FINALLY MOVE THROUGH THE REGION BY EARLY WEDNESDAY.
AS WE GO INTO WEDNESDAY THE LAST OF THE CONVECTION WILL EXIT THE
REGION BY WEDNESDAY AFTERNOON. A BROAD UPPER TROUGH WILL CONTINUE
OVER THE REGION FOR MOST OF THE PERIOD THROUGH FRIDAY BEFORE THE
UPPER TROUGH FINALLY LIFTS OUT OVER THE WEEKEND. THE MODEL GUIDANCE
TRIES TO BRING IN LOW POPS FOR WEDNESDAY THROUGH SATURDAY. THE EURO
TRIED TO SHOW SOME LOW QPF FROM THURSDAY THROUGH SATURDAY...BUT OPTED
TO KEEP THE REGION DRY. SOME COOL AIR WILL PUSH INTO THE REGION FOR
THURSDAY INTO FRIDAY WITH LOWS IN THE 40S AND 50S REACHING INTO THE
FIRST FEW DAYS OF MAY...WHICH WILL RUN AROUND TEN DEGREES BELOW
NORMAL. /17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 85 66 82 69 / 18 12 30 43
MERIDIAN 85 63 83 66 / 13 9 24 30
VICKSBURG 85 68 82 71 / 18 14 41 53
HATTIESBURG 87 67 83 68 / 19 12 20 22
NATCHEZ 85 68 84 70 / 20 12 32 37
GREENVILLE 84 67 80 69 / 5 18 71 79
GREENWOOD 86 67 82 70 / 4 11 56 63
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
27/22/EC/17
AREA FORECAST DISCUSSION
NWS JACKSON MS
513 AM CDT SAT APR 26 2014
...SEVERE WEATHER OUTBREAK EXPECTED FROM SUNDAY NIGHT THROUGH
TUESDAY AND SIGNIFICANT FLOOD EVENT POSSIBLE AS WELL...
.DISCUSSION...
TODAY AND TONIGHT...
THERE IS A WRINKLE IN WHAT WAS SUPPOSED TO CLEARLY BE A DRY FORECAST
FOR SATURDAY. THE NCEP WRF AND HRRR GUIDANCE SUGGEST AN EAST-WEST
ORIENTED BROKEN LINE OF SHOWERS MAY DEVELOP LATER TODAY WITH DAYTIME
HEATING ALONG THE NORTHERN EDGE OF RICHER LOW LEVEL MOISTURE NEAR THE
GULF COAST. HAVE RAISED POPS TO SLIGHT CHANCE CATEGORY FOR LOCATIONS
ALONG AND SOUTH OF I-20. CONFIDENCE IS LOW IN THIS ACTIVITY
MATERIALIZING GIVEN THE DRY AIR (PRECIPITABLE WATER < .50 INCH) THAT
NEEDS TO BE OVERCOME AND GENERAL LACK OF LIFT ON ANY SCALE. EXPECT
ANY SHOWER ACTIVITY TO DIMINISH QUICKLY WITH SUNSET THIS
EVENING. OTHERWISE...EXPECT INCREASING LOW CLOUDS AS HIGHER QUALITY
BOUNDARY LAYER MOISTURE BEGINS TO SURGE INLAND.
SUNDAY THROUGH MONDAY NIGHT...
HIGH FORECAST CONFIDENCE CONTINUES REGARDING A DANGEROUS SET-UP FOR
SEVERE WEATHER AND HEAVY RAINFALL FROM LATE SUNDAY THROUGH TUESDAY
NIGHT. ALL MODES OF SEVERE WEATHER INCLUDING THE POTENTIAL FOR STRONG
TORNADOES WILL BE POSSIBLE AS A LARGE AND DEEP VORTEX LOCKS IN OVER
THE CENTRAL CONUS AND SENDS SEVERAL LOBES OF SHORTWAVE TROUGH ENERGY
ACROSS THE ARKLAMISS. GIVEN THE PERSISTENCE OF THIS PATTERN AND
AVAILABILITY OF ANOMALOUS MOISTURE...A SIGNIFICANT FLOODING EVENT IS
PROBABLE AS WELL.
THE RISK FOR SEVERE WEATHER COULD RAMP UP QUICKLY LATE SUNDAY
AFTERNOON INTO THE EVENING IN THE DELTA REGION. GUIDANCE CONTINUES
TO INDICATE THAT RAPID MOISTENING AND DESTABILIZATION ASSOCIATED
WITH INCREASINGLY CYCLONIC FLOW ALOFT WILL ALLOW FOR SHOWER/THUNDERSTORM
ACTIVITY TO BREAK OUT AS EARLY AS SUNDAY MORNING. BY SUNDAY AFTERNOON
AND EVENING A VERY UNSTABLE (ML CAPE > 2500 J/KG) AND HIGHLY SHEARED
ENVIRONMENT (0-1KM ~45 KTS) IS EXPECTED AS LAPSE RATES STEEPEN ABOVE
A STRENGTHENING LOW LEVEL JET (50-60KTS). LARGE CLOCKWISE HODOGRAPHS
WILL SUPPORT SUPERCELL THUNDERSTORMS WITH INTENSE ROTATING UPDRAFTS
AND STRONG TORNADO POTENTIAL OVER THE DELTA REGION BY SUNDAY
EVENING. CONFIDENCE IS INCREASING THAT THE GREATER RISK FOR SEVERE
WEATHER WILL REMAIN MAINLY OVER THE DELTA REGION SUNDAY NIGHT. BUT
A QUASI-LINEAR CONVECTIVE SYSTEM COULD EVENTUALLY EVOLVE...AND IF
THIS HAPPENS WE WOULD EXPECT COLD POOL GENERATION TO HELP GIVE THE
SYSTEM SOME EASTWARD ACCELERATION ALONG THE HWY 82 CORRIDOR...PERHAPS
REACHING THE NATCHEZ TRACE CORRIDOR. IT IS UNCLEAR HOW MUCH SUCH AN
MCC WILL DIMINISH DURING THE EARLY MONDAY MORNING HOURS...BUT THERE
MAY BE SOMEWHAT OF A LULL BEFORE THE NEXT ROUND OF SHORTWAVE ENERGY
APPROACHES.
AS WE GO INTO MONDAY AFTERNOON AND EVENING...EXPECT RE-NEWED SEVERE
THUNDERSTORM ACTIVITY WHEN A RIBBON OF STRONGER PACIFIC JET ENERGY
ROUNDS THE BASE OF THE DEEP CENTRAL CONUS TROUGH AND ENHANCES WIND
SHEAR/LIFT AND THE SEVERE WEATHER RISK OVER THE FORECAST AREA. MIXED
LAYER CAPE NEAR 3000 J/KG COULD HELP MAKE FOR A VOLATILE SET-UP WITH
THIS SYNOPTIC PATTERN. THE INITIAL CONVECTION SHOULD EVENTUALLY
EVOLVE INTO ANOTHER LINEAR CONVECTIVE SYSTEM...AND WITH DEEP LAYER
SHEAR VECTORS BECOMING MORE PARALLEL RESULTING IN GREATER POTENTIAL
FOR TRAINING AND BACK-BUILDING OF STORMS...THE RISK FOR HEAVY
RAINFALL AND FLOODING COULD REALLY RAMP UP MONDAY NIGHT. THE ECMWF IS
A LITTLE MORE PROGRESSIVE WITH SUCH A SYSTEM WHILE THE GFS SHOWS A
GREATER PROPENSITY FOR PARALLEL DEEP LAYER FLOW AND CORFIDI VECTOR
RIDGING SUGGESTIVE OF MCS BACK-BUILDING AND SLOW SYSTEM SPEED. WHILE
IT IS DIFFICULT TO KNOW WHERE IT WILL SET UP EXACTLY...WITH K INDICES
IN THE LOW 40S AND PRECIPITABLE WATER APPROACHING 2 INCHES...THERE
WILL LIKELY BE INTENSE RAINFALL RATES OF WHICH ANY LONG DURATION
COULD LEAD TO SERIOUS FLOODING CONCERNS.
CIPS ANALOGS ARE STILL SHOWING VERY SIGNIFICANT EVENTS FOR COMPARISON
TO THIS SET-UP ADDING MORE CONFIDENCE THAT SIGNIFICANT SEVERE WEATHER
AND FLOODING WILL BE POSSIBLE. THE LATEST ANALOG CONSENSUS HAS
SHIFTED BACK A LITTLE FARTHER NORTH WITH HIGHER SEVERE WEATHER/HEAVY
RAINFALL PROBS FROM SUNDAY NIGHT THROUGH MONDAY NIGHT...BEFORE
SHIFTING SOUTHWARD FOR THE TIME CENTERED ON THE MORE UNCERTAIN
TUESDAY EVENING PERIOD. TO MAINTAIN CONSISTENCY WILL NOT MAKE ANY
SIGNIFICANT ADJUSTMENTS AT THIS POINT TO THE RISK AREAS...BUT WILL
ADD SOME MORE DETAIL. /EC/
TUESDAY THROUGH NEXT SATURDAY...
A VOLATILE PATTERN SUPPORTIVE OF SEVERE WEATHER/TORNADOES AND
ADDITIONAL HEAVY RAIN MAY CONTINUE TUESDAY INTO TUESDAY NIGHT. THE
FORECAST FOR THIS PERIOD IS MORE UNCERTAIN HOWEVER AS IT WILL HINGE
GREATLY ON THE BEHAVIOR OF MONDAY NIGHT CONVECTIVE ACTIVITY. A
STRONG CLOSED H5 CLOSED LOW WILL EXIST OVER IOWA EARLY TUESDAY WHICH
IS CHARACTERIZED BY A 120KT CYCLONICALLY CURVED JET WITH MULTIPLE
EJECTING LOBES OVERTOP A MOIST UNSTABLE MODERATELY SHEARED
ENVIRONMENT ACROSS THE ARKLAMISS. THIS SET-UP WILL SUPPORT VIGOROUS
CONVECTIVE DEVELOPMENT AGAIN FOR TUESDAY AFTERNOON AND EVENING.
ADDITIONAL HEAVY RAIN WILL BE POSSIBLE WITH PRECIPITABLE WATER
AROUND 1.8 INCHES AND FAVORABLE WIND PROFILES FOR TRAINING OF STORMS
LEADING TO FLASH FLOODING AND SIGNIFICANT RIVER RISES. THE ASSOCIATED
COLD FRONT WILL FINALLY MOVE THROUGH THE REGION BY EARLY WEDNESDAY.
AS WE GO INTO WEDNESDAY THE LAST OF THE CONVECTION WILL EXIT THE
REGION BY WEDNESDAY AFTERNOON. A BROAD UPPER TROUGH WILL CONTINUE
OVER THE REGION FOR MOST OF THE PERIOD THROUGH FRIDAY BEFORE THE
UPPER TROUGH FINALLY LIFTS OUT OVER THE WEEKEND. THE MODEL GUIDANCE
TRIES TO BRING IN LOW POPS FOR WEDNESDAY THROUGH SATURDAY. THE EURO
TRIED TO SHOW SOME LOW QPF FROM THURSDAY THROUGH SATURDAY...BUT OPTED
TO KEEP THE REGION DRY. SOME COOL AIR WILL PUSH INTO THE REGION FOR
THURSDAY INTO FRIDAY WITH LOWS IN THE 40S AND 50S REACHING INTO THE
FIRST FEW DAYS OF MAY...WHICH WILL RUN AROUND TEN DEGREES BELOW
NORMAL./17/
&&
.AVIATION...VFR CONDITIONS ARE ANTICIPATED FOR THE MOST PART TODAY
THROUGH THIS EVENING. WIDESPREAD IFR CATEGORY STRATUS MAY SPREAD
NORTH ACROSS THE FORECAST AREA LATE TONIGHT. THUNDERSTORM POTENTIAL
WILL BE ON THE POTENTIAL FOR SUNDAY INTO SUNDAY NIGHT...AND EARLY
NEXT WEEK LOOKS LIKE A STRETCH OF ROUGH WEATHER FOR AVIATION
INTERESTS. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 85 66 82 69 / 18 12 30 43
MERIDIAN 85 63 83 66 / 13 9 24 30
VICKSBURG 85 68 82 71 / 18 14 41 53
HATTIESBURG 87 67 83 68 / 19 12 20 22
NATCHEZ 85 68 84 70 / 20 12 32 37
GREENVILLE 84 67 80 69 / 5 18 71 79
GREENWOOD 86 67 82 70 / 4 11 56 63
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
EC/17/
AREA FORECAST DISCUSSION
NWS BILLINGS MT
328 PM MDT SAT APR 26 2014
.SHORT TERM...VALID FOR SUN AND MON...
SCATTERED SHOWERS AND THUNDERSTORMS WERE MOVING N TOWARD THE
FORECAST AREA FROM WY THIS AFTERNOON PER RADAR IMAGERY AND
LIGHTNING DATA. CAPES HAVE BEEN INCREASING OVER THE AREA SO HAVE
INCREASED THE CHANCE OF THUNDER FOR THIS EVENING. THE CAPES WERE
FORECAST TO DIMINISH BY THE RAP AFTER 03Z...SO WILL ONLY HAVE A
SLIGHT CHANCE OF THUNDER FOR THE LATE EVENING. BULK SHEAR WAS ALSO
FAVORABLE ACROSS THE REGION IN SUPPORT OF THUNDERSTORMS.
COMPACT UPPER LOW WAS SEEN ON WATER VAPOR IMAGERY MOVING THROUGH
AZ THIS AFTERNOON. PLENTY OF MOISTURE WAS SPREADING N OUT FROM THE
LOW IN SW FLOW ALOFT. MODELS AGREED THAT THE UPPER LOW WILL REACH
SE CO BY 12Z SUN...ALLOWING THE TROUGH TO GO NEGATIVE TILT AND TAP
GULF OF MEXICO MOISTURE. THE LOW WILL MERGE WITH THE NORTHERN
BRANCH OF THE TROUGH AS IT MOVES NE THROUGH MON INTO THE CENTRAL
PLAINS. THE LARGER CUTOFF WILL THEN MEANDER E MON NIGHT.
AT THE SURFACE...AMORPHOUS LOW CENTERS WERE ALONG THE SOUTHERN
EDGE OF THE FORECAST AREA THIS AFTERNOON. THESE LOWS WERE FORECAST
TO MERGE OVER NE OR E CO BY 12Z SUN WITH AN INVERTED TROUGH
EXTENDING FROM THE MERGED LOW INTO THE EASTERN FORECAST AREA. A
HALF INCH TO AN INCH OF QPF WILL FALL OVER THE WESTERN ZONES
TONIGHT BEFORE THE PRECIPITATION FOCUS SHIFTS TO SE MT...E OF
KBIL...DURING SUN MORNING DUE TO THE INVERTED TROUGH. THE INVERTED
TROUGH WILL SHIFT SLOWLY E DURING SUN AND A HALF INCH TO AN INCH
OF PRECIPITATION IS EXPECTED TO FALL OVER SE MT. THE BEST CHANCES
FOR SNOW WILL BE THIS EVENING OVER THE BEARTOOTHS AND ABSAROKAS
DUE TO A COMBINATION OF LIFT AND INSTABILITY...BUT DENDRITIC
GROWTH WILL BE HIGHER IN THE ATMOSPHERE LIMITING THE GREATER
ACCUMULATIONS TO THE HIGHEST ELEVATIONS. THE MAJORITY OF THE
MODELS KEPT THE INVERTED TROUGH AND ASSOCIATED PRECIPITATION GOING
OVER THE SE THROUGH MON WITH THE ECMWF BEING FURTHEST E OVER THE
DAKOTAS. ANOTHER THREE-QUARTERS OF AN INCH OF PRECIPITATION WILL
BE POSSIBLE SUN NIGHT...WITH MUCH LESSER AMOUNTS EXPECTED MON.
SOME LINGERING PRECIPITATION IS EXPECTED OVER THE SE MON NIGHT.
CONTINUED THE FORECAST OF RAIN MIXING WITH THE SNOW LATE SUN NIGHT
AND MON NIGHT. A COUPLE INCHES OF SNOW WILL BE POSSIBLE OVER THE
SE SUN NIGHT. ONLY MADE SLIGHT POP AND TEMPERATURE ADJUSTMENTS
THROUGH THE PERIOD. HIGHS WILL BE IN THE 40S AND 50S SUN AND MON.
STILL EXPECTING GUSTY NW WINDS BEHIND THE SURFACE LOW BEGINNING
TONIGHT. WILL CONTINUE THE ESF FOR RISING RIVERS AND STREAMS. ARTHUR
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
THE LARGE SCALE SYNOPTIC PATTERN ACROSS THE CONUS WILL EVOLVE
SLOWLY THROUGH MIDDLE TO LATE NEXT WEEK AS A BLOCKING PATTERN
CONTINUES. TUESDAY THROUGH THURSDAY THE LARGE UPPER-LEVEL LOW
WILL DRIFT FROM THE CENTRAL PLAINS TO THE GREAT LAKES AREA...
WHICH WILL RESULT IN A CONTINUED WET AND COOL PATTERN FOR THE
EASTERN PORTIONS OF THE FORECAST AREA. THE MOISTURE TRANSPORT
WILL SLOWLY DIMINISH EACH DAY... AND WILL ALLOW PRECIPITATION
TO SLOWLY TAPER OFF. WHILE MODELS HAVE CONTINUED TO SHOW SLOW
BREAKDOWN OF THE BLOCKING PATTERN... THURSDAY WILL FINALLY BE
WARMER AND DRIER AS ANTICYCLONIC FLOW FINALLY BUILDS IN ALOFT
ALONG WITH WARMER 850 MB TEMPERATURES.
THE MODEL TREND HAS BEEN TOWARD A SLIGHTLY SLOWER PROGRESSION
OF THE MEAN UPPER-LEVEL LOW ON TUESDAY AND WEDNESDAY... WHICH
WILL COMBINE WITH SOME ADDITIONAL VORTICITY BEING ADVECTED IN
TO THE FORECAST AREA FROM THE EAST ON TUESDAY. THIS WILL MAKE
FOR A WETTER TUESDAY ACROSS EASTERN MONTANA THAN WE INITIALLY
THOUGHT. THUS...HAVE DECIDED TO INCREASE POPS TO LIKELIES FOR
AREAS EAST OF FORSYTH ON TUESDAY AFTERNOON. TEMPERATURES WILL
ALSO BE FAIRLY COOL ACROSS THE EAST ... WITH THERMAL PROFILES
SHOWING THE POTENTIAL FOR SNOW TO MIX WITH RAIN EARLY TUESDAY
MORNING AND THEN AGAIN EARLY WEDNESDAY MORNING. FARTHER WEST
THE TEMPERATURES WILL SLOWLY START TO MODERATE INTO WEDNESDAY
AS THE NORTH-SOUTH ORIENTED JET STREAM SLOWLY PUSHES EASTWARD
AND ALLOWS FOR +10C 850 MB TEMPERATURES TO MOVE INTO THE WEST
HALF OF THE FORECAST AREA. SHOWERS ARE STILL POSSIBLE ACROSS
SOUTH CENTRAL MONTANA ON TUESDAY AND WEDNESDAY ... GIVEN SOME
ADDITIONAL FORCING WRAPPING BACK AROUND THE LOW...HOWEVER THE
MAIN DETERRENT TO REALIZING THIS POTENTIAL REMAINS THE STRONG
NORTHWESTERLY DOWNSLOPE WINDS.
ANOMALOUSLY STRONG NORTHWESTERLY WINDS WILL CONTINUE FOR MUCH
OF THE FORECAST AREA ON TUESDAY..WITH THE WINDS SLOWLY TAPER-
ING OFF WEDNESDAY INTO THURSDAY. THE PATTERN FAVORS STRONGEST
WINDS ACROSS SOUTHEAST MONTANA AND INTO SHERIDAN WY GIVEN THE
SURFACE LOW ACROSS THE CENTRAL CONUS SUPPORTING A TIGHT PRES-
SURE GRADIENT ACROSS THE CENTRAL AND EASTERN CWA. CIPS ANALOG
GUIDANCE SHOWS 50 TO 70 PCT CHANCE OF WIND GUSTS GREATER THAN
30 KTS FROM BILLINGS TO SHERIDAN AND ACROSS SE MT ON TUESDAY.
AFTER THE WARMING AND DRYING TREND ON THURSDAY... MODEL SOLU-
TIONS DIVERGE READILY. HOWEVER ... THE OVERALL TREND SEEMS TO
BE TOWARD NORTHWESTERLY FLOW... WHICH KEEP US FROM WARMING UP
SIGNIFICANTLY AND WILL KEEP A SLGT CHANCE OF PRECIPITATION IN
THE FORECAST TO END THE WEEK.
CHURCH
&&
.AVIATION...
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AND SPREAD INTO
THE FORECAST AREA THIS EVENING. ACCOMPANYING THESE SHOWERS WILL BE
MOUNTAIN OBSCURATIONS AS WELL AS LOCALIZED MVFR CONDITIONS. EXPECT
TO SEE THUNDER ACTIVITY DECREASE THIS EVENING AS INSTABILITY LESS-
ENS AFTER SUNSET. SHOWERS WILL BECOME MORE WIDESPREAD FOR THE AREA
TONIGHT AND COULD EVEN BECOME HEAVY AT TIMES.
CHURCH
&&
.PRELIMINARY POINT TEMP/POPS...
SUN MON TUE WED THU FRI SAT
-----------------------------------------------------------
BIL 042/056 036/051 035/053 036/057 037/062 039/065 041/058
97/W 32/W 23/W 21/N 11/B 12/W 22/W
LVM 035/057 033/047 032/051 033/057 035/060 035/062 037/061
+5/W 33/W 23/W 11/B 11/U 12/W 22/W
HDN 041/056 033/051 035/052 033/058 032/061 035/066 038/059
89/W 65/W 34/W 42/W 11/B 12/W 22/W
MLS 043/047 034/047 035/048 032/051 033/058 037/063 039/058
9+/R 97/O 56/R 53/W 11/B 12/W 22/W
4BQ 042/048 033/046 035/046 032/050 031/057 034/062 037/058
9+/R 97/O 56/R 53/W 11/B 12/W 22/W
BHK 042/045 033/044 034/042 031/049 031/054 034/058 036/057
7+/R +8/O 66/R 43/W 12/W 12/W 22/W
SHR 039/053 031/046 033/048 033/050 032/056 033/060 036/060
88/W 55/W 24/W 42/W 11/B 12/W 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
241 PM MDT SAT APR 26 2014
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...
NOT TOO MANY CHANGES IN REGARD TO CHANCES OF PRECIPITATION...BUT
MODELS DID BACK OFF ON SNOW CHANCES/AMOUNTS.
UPPER TROUGH THE MAIN WEATHER MAKER FOR THE AREA THROUGH THE PERIOD.
PRECIPITATION WILL BE MAINLY CONVECTIVE INTO THIS EVENING THEN
TRANSITION TO STRATIFORM BY SUNDAY. THEREFORE AMOUNTS TONIGHT WILL
BE LOWER CONFIDENCE THAN SUNDAY.
SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP THIS LATE THIS
AFTERNOON AND MOVE NORTH. HRRR HAS THIS AREA INITIATING NEAR A
BOUNDARY NEAR MILES CITY LATE THIS AFTERNOON AT ABOUT 4 PM. AREA
GRADUALLY FILLS IN OVERNIGHT AND SUNDAY AS ISENTROPIC FLOW DEVELOPS.
SUNDAY NIGHT AND MONDAY...ISENTROPIC FLOW CONTINUES AS THE UPPER LOW
TROUGH CUTS OFF NEAR SD/NE. PERIOD OF RAIN LOOKS TO MOVE NW BACK
INTO THE AREA MONDAY MORNING. THE EC KEEPS IT AWAY FROM THE WESTERN
ZONES...SO LOWERED QPFS/POPS THERE. TEMPERATURES LOOK COLDER NOW OVER
THE NE ZONES RATHER THAN OPHEIM AREA FOR SNOW OR A SNOW/RAIN MIX
MAINLY MONDAY MORNING. CONFIDENCE IS STILL LOW BUT AN INCH STILL
LOOKS POSSIBLE. TFJ
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
BY MONDAY NIGHT THE LINGERING OUTER BANDS OF PRECIPITATION FROM
THE CURRENT STORM SYSTEM WILL STILL BE AFFECTING NORTHEAST
MONTANA...EVEN WITH THE CENTER OF THE 500-MB LOW BEING OVER KANSAS
CITY. THIS WILL LIKELY MATERIALIZE FOR OUR CWA IN THE FORM OF
SCATTERED BANDS OF RAIN SHOWERS...OCCASIONALLY MIXED WITH SNOW
DURING THE NIGHTTIME AND OVER THE HIGHER ELEVATIONS. MONDAY NIGHT
THROUGH TUESDAY...THE UPPER-LEVEL FLOW OVER NORTHEAST MONTANA WILL
BE RATHER BENIGN.
BY LATE THURSDAY NIGHT...A STRONG RIDGE OF HIGH PRESSURE WITH ITS
AXIS DOWN THE SPINE OF THE CASCADE RANGE...WILL START TO PUSH INTO
NORTHEAST MONTANA FROM THE WEST...WITH STRONGER FLOW ALOFT FROM
THE NORTH. THIS WILL CLEAR OUT ANY REMAINING RAIN SHOWERS...CLEAR
OUT THE SKIES...AND ALLOW TEMPERATURES TO WARM BACK UP TO MORE
NORMAL LEVELS FOR THIS TIME OF YEAR. BMICKELSON
PREVIOUS LONG TERM DISCUSSION...THE EXTENDED PERIOD BEGINS MONDAY
EVENING WITH A LONG-WAVE STACKED UP LOW CENTERED OVER THE CENTRAL
PLAINS. NORTHEAST MONTANA WILL STILL BE UNDER A WEAKENING INVERTED
SURFACE TROUGH WITH WRAP- AROUND LIGHT PRECIPITATION INTO MID-
WEEK.
MONDAY NIGHT THE SURFACE LOW WILL BE SOMEWHERE OVER SOUTH DAKOTA.
THIS WILL PULL COLDER AIR FROM CANADA SOUTH OVER NEMONT. THERE
WILL BE SOME 850MB TEMPERATURES BELOW 0C. THIS CAA COULD RESULT IN
SOME SNOW MIXING IN WITH THE RAIN. BUT QPF BY THEN WILL BE
LIMITED...SO NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION.
A BLOCKING PATTERN FARTHER EAST WILL PREVENT THE LARGE TROUGH
FROM MOVING EAST TOO QUICKLY. AN AMPLIFIED RIDGE BUILDS UP WEST OF
THE ROCKY MOUNTAINS BUT DOES NOT ADVANCE MUCH...KEEPING NORTHEAST
MONTANA UNDER THE INFLUENCE OF THE TROUGH AND KEEPING TEMPERATURE
SEASONAL OR ON THE COOL SIDE AT LEAST THROUGH MID-WEEK. THE
TRANSITION FROM THE INFLUENCE OF THE COOLER LOW AND THE WARMER
RIDGE IS HARD TO DETERMINE. EXACTLY WHEN THE STATIONARY BOUNDARY
BETWEEN THE COMPETING AIR MASSES WILL SHIFT EAST OF NORTHEAST
MONTANA IS NOT CERTAIN WITHIN A COUPLE OF PERIODS. BUT AFTER MID-
WEEK THE BOUNDARY COULD BE FAR ENOUGH EAST FOR TEMPERATURES TO
ONCE AGAIN RISE ABOVE NORMAL. THE HIGH PRESSURE CONDITIONS WILL
ALSO DRY THINGS OUT.
TOWARDS THE END OF THE EXTENDED PERIOD THE GFS AND EC HAVE
DIFFERENT IDEAS AS TO HOW THE PATTERN WILL PLAY OUT. BUT BOTH
MODELS HINT AS COOLER AND WETTER CONDITIONS MOVING IN BY THE
WEEKEND. SCT
&&
.AVIATION...
SYNOPSIS: THE LARGE AND POWERFUL SPRING STORM SYSTEM...SPREADING
MULTIPLE PERIODS OF SHOWERS AND DRY SLOTS ACROSS MOST OF THE
INTER-MOUNTAIN WEST AND ADJACENT HIGH PLAINS REGIONS WILL
CONTINUE TO DO SO WELL THROUGH THE END OF THIS TAF CYCLE.
FLIGHT CATEGORY: VFR TODAY THROUGH EARLY THIS AFTERNOON. ISOLATED
MVFR WILL BE POSSIBLE WITH SOME VICINITY THUNDERSTORMS LATER THIS
AFTERNOON INTO EARLY THIS EVENING. EXPECT WIDESPREAD IFR TO
BORDERLINE LIFR TO LOCK INTO ALL TAF SITES AFTER MIDNIGHT TONIGHT.
SKY/WEATHER: WITH SKIES CLEARING IN PART TODAY TO ALLOW SOME
HEATING OF THE MOIST SURFACE LAYER...A FEW VICINITY THUNDERSTORMS
WILL BE POSSIBLE DURING THE LATE AFTERNOON AND EVENING
HOURS...ESPECIALLY FROM KGDV TOWARD KOLF. AFTER
MIDNIGHT...CEILINGS WILL LOWER DRASTICALLY AND WIDESPREAD MODERATE
TO HEAVY RAIN WILL SETTLE IN FOR ALL TAF SITES TOWARD THE END OF AND
WELL BEYOND THIS TAF PERIOD.
WIND: GENERALLY FROM THE EAST 20-30 MPH MID DAY...INCREASING 30-40
MPH THIS AFTERNOON...THEN DIMINISHING BACK TO 15-25 WITH THE
ONSET OF HEAVY RAIN LATE TONIGHT. EXPECT CROSSWIND HAZARDS FOR
NORTH-TO-SOUTH ORIENTED RUNWAYS.
BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 6 AM MDT SUNDAY FOR FORT PECK LAKE FOR
CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...
GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1030 PM CDT SUN APR 27 2014
.SYNOPSIS...
ISSUED AT 407 PM CDT SUN APR 27 2014
A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS
THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN
CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS.
DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE
EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE
SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT
EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED
NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA
PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO
MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND
70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN
NEBRASKA...WHERE IT TURNED SOUTHEAST INTO SOUTH CENTRAL NEBRASKA.
THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE
TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER
DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND
NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL
SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE
AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING
THE MAIN SEVERE THREAT.
&&
.UPDATE...
ISSUED AT 1027 PM CDT SUN APR 27 2014
THE HIGH WIND WATCH HAS BEEN UPGRADED TO A HIGH WIND WARNING BASED
ON THE RAP AND 00Z NAM MODEL RUNS WHICH KEEP THE STRONGEST WINDS
ALONG HIGHWAY 61. THE AREA TO WATCH IS THE CENTRAL SANDHILLS WHERE
THE RAP AND NAM SHOW VERY STRONG 500M AGL WINDS APPROACHING 40 MPH
AT THE SFC MONDAY AFTERNOON.
NOTE THE FORECAST CONTINUES STRONG OR HIGH WINDS MONDAY NIGHT AND
TUESDAY WHICH WOULD NECESSITATE EXTENSIONS OF THE ON GOING HIGH
LIGHTS.
UPDATE ISSUED AT 837 PM CDT SUN APR 27 2014
A LOOK AT THE NEBRASKA DOR CAMS AND THE RAP MODEL SUGGEST WINTER
WEATHER ADVISORY CONDITIONS ACROSS SHERIDAN AND WESTERN CHERRY
COUNTIES. THE RAP INDICATES SEVERAL INCHES OF WET SNOW THIS
EVENING WHICH TAPERS OFF OR MIXES WITH RAIN AFTER MIDNIGHT. RADAR
INDICATES A DEFORMATION ZONE UNDERWAY ACROSS THIS AREA BUT MAINLY
ACROSS NRN SHERIDAN COUNTY. A WINTER ADVISORY IS IN PLACE FOR
THESE AREA AND IT OPERATES UNTIL 13Z.
THE FORECAST UPDATE FOLLOWS 50 PERCENT OF THE 23Z RAP AND 50
PERCENT OF THE PREVIOUS FORECAST. THE PTYPE USES THE RAP MODEL
WHICH SPREADS WET SNOW AS FAR SOUTH AS DEUEL COUNTY BUT LITTLE
ACCUMULATION IS EXPECTED THAT FAR SOUTH. IT LOOKS LIKE THE FAVORED
AREA FOR SNOW IS NORTHWEST NEBRASKA...NORTH OF THE NORTH PLATTE
VALLEY FOLLOWING THE H750 MB FRONT WHICH IS STRONGLY STACKED AND
MOVING VERY SLOWLY EAST TONIGHT. NOTE THE 23Z RAP PRODUCES OVER 1
INCH OF QPF ACROSS SHERIDAN COUNTY TONIGHT. THE FORECAST USES A
RATIO OF 6 TO 1 FOR 3 TO NEARLY 8 INCHES OF SNOW FAVORING PINE
RIDGE.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 407 PM CDT SUN APR 27 2014
FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN
LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL.
THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH
THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK.
WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST
KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE
TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND
OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE
CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS
STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW.
THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY
00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO
AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z
NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE
CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE
OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF
THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS
OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE
TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD
DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS
COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG
QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN
TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP
BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS
ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY
THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT
WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN
ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER
COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET
DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE
WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO
SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2
INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE.
THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND
THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED
THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE
SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO
CIRCULATE AROUND THE SYSTEM.
MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON
THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN
ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND
ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT
PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL
LOOK LIKELY.
WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER
THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A
NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY
MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO
SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF
HEADLINES ARE NEEDED.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 407 PM CDT SUN APR 27 2014
TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND
PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL
LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER
MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO
PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING
THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA
MONDAY NIGHT AND TUESDAY NIGHT.
FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN
FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL
MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY
LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN
PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS
IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND
SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND
DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID
CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY
WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN
THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT
AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND
WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE
CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS
WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY
CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL
HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE
IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE
FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE.
LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE
MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN
WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS
TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE
WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH
LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS
AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL
CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE
FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET
UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON
HOURS.
ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME
IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND
NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE
OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY
MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT
DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR
MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON
ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT
ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER
CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO
CATEGORICAL POPS OVERNIGHT.
TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON
TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY
THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL
CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL
DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR
TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL
HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C
IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL
STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85
TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST.
AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS
WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30
MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT
ANTICIPATING ANY WIND HEADLINES ATTM.
WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED
BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK.
HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL
CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN
THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH
THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE
50S EXPECTED FRIDAY...SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 643 PM CDT SUN APR 27 2014
WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH
MONDAY AFTERNOON AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL
PLAINS. WINDS 32035G45KT SHOULD SPREAD FROM WEST TO EAST TONIGHT
AND CONTINUE THROUGH MONDAY AFTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 7 AM CDT /6 AM MDT/ TO 7 PM CDT /6 PM
MDT/ MONDAY FOR NEZ022-035-056>058-069-070.
WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NEZ022-035-
056>058-069-070.
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ004-
023>025-036-037-059-071-094.
WINTER WEATHER ADVISORY UNTIL 7 AM MDT MONDAY FOR NEZ004-094.
WIND ADVISORY FROM 7 AM TO 7 PM CDT MONDAY FOR NEZ005-006-008-
009-026-027-038.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...BROOKS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
839 PM CDT SUN APR 27 2014
.SYNOPSIS...
ISSUED AT 407 PM CDT SUN APR 27 2014
A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS
THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN
CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS.
DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE
EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE
SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT
EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED
NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA
PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO
MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND
70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN
NEBRASKA...WHERE IT TURNED SOUTHEAST INOT SOUTH CENTRAL NEBRASKA.
THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE
TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER
DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND
NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL
SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE
AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING
THE MAIN SEVERE THREAT.
&&
.UPDATE...
ISSUED AT 837 PM CDT SUN APR 27 2014
A LOOK AT THE NEBRASKA DOR CAMS AND THE RAP MODEL SUGGEST WINTER
WEATHER ADVISORY CONDITIONS ACROSS SHERIDAN AND WESTERN CHERRY
COUNTIES. THE RAP INDICATES SEVERAL INCHES OF WET SNOW THIS
EVENING WHICH TAPERS OFF OR MIXES WITH RAIN AFTER MIDNIGHT. RADAR
INDICATES A DEFORMATION ZONE UNDERWAY ACROSS THIS AREA BUT MAINLY
ACROSS NRN SHERIDAN COUNTY. A WINTER ADVISORY IS IN PLACE FOR
THESE AREA AND IT OPERATES UNTIL 13Z.
THE FORECAST UPDATE FOLLOWS 50 PERCENT OF THE 23Z RAP AND 50
PERCENT OF THE PREVIOUS FORECAST. THE PTYPE USES THE RAP MODEL
WHICH SPREADS WET SNOW AS FAR SOUTH AS DEUEL COUNTY BUT LITTLE
ACCUMULATION IS EXPECTED THAT FAR SOUTH. IT LOOKS LIKE THE FAVORED
AREA FOR SNOW IS NORTHWEST NEBRASKA...NORTH OF THE NORTH PLATTE
VALLEY FOLLOWING THE H750 MB FRONT WHICH IS STRONGLY STACKED AND
MOVING VERY SLOWLY EAST TONIGHT. NOTE THE 23Z RAP PRODUCES OVER 1
INCH OF QPF ACROSS SHERIDAN COUNTY TONIGHT. THE FORECAST USES A
RATIO OF 6 TO 1 FOR 3 TO NEARLY 8 INCHES OF SNOW FAVORING PINE
RIDGE.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 407 PM CDT SUN APR 27 2014
FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN
LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL.
THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH
THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK.
WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST
KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE
TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND
OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE
CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS
STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW.
THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY
00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO
AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z
NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE
CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE
OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF
THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS
OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE
TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD
DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS
COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG
QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN
TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP
BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS
ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY
THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT
WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN
ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER
COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET
DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE
WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO
SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2
INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE.
THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND
THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED
THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE
SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO
CIRCULATE AROUND THE SYSTEM.
MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON
THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN
ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND
ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT
PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL
LOOK LIKELY.
WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER
THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A
NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY
MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO
SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF
HEADLINES ARE NEEDED.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 407 PM CDT SUN APR 27 2014
TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND
PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL
LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER
MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO
PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING
THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA
MONDAY NIGHT AND TUESDAY NIGHT.
FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN
FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL
MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY
LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN
PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS
IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND
SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND
DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID
CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY
WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN
THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT
AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND
WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE
CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS
WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY
CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL
HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE
IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE
FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE.
LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE
MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN
WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS
TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE
WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH
LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS
AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL
CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE
FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET
UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON
HOURS.
ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME
IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND
NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE
OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY
MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT
DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR
MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON
ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT
ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER
CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO
CATEGORICAL POPS OVERNIGHT.
TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON
TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY
THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL
CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL
DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR
TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL
HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C
IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL
STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85
TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST.
AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS
WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30
MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT
ANTICIPATING ANY WIND HEADLINES ATTM.
WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED
BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK.
HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL
CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN
THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH
THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE
50S EXPECTED FRIDAY...SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 643 PM CDT SUN APR 27 2014
WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH
MONDAY AFTERNOON AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL
PLAINS. WINDS 32035G45KT SHOULD SPREAD FROM WEST TO EAST TONIGHT
AND CONTINUE THROUGH MONDAY AFTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NEZ022-035-
056>058-069-070.
HIGH WIND WATCH FROM 7 AM CDT /6 AM MDT/ MONDAY THROUGH MONDAY
EVENING FOR NEZ022-035-056>058-069-070.
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ004-
023>025-036-037-059-071-094.
WINTER WEATHER ADVISORY UNTIL 7 AM MDT MONDAY FOR NEZ004-094.
WIND ADVISORY FROM 7 AM TO 7 PM CDT MONDAY FOR NEZ005-006-008-
009-026-027-038.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...BROOKS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
645 PM CDT SUN APR 27 2014
.SYNOPSIS...
ISSUED AT 407 PM CDT SUN APR 27 2014
A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS
THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN
CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS.
DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE
EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE
SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT
EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED
NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA
PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO
MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND
70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN
NEBRASKA...WHERE IT TURNED SOUTHEAST INOT SOUTH CENTRAL NEBRASKA.
THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE
TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER
DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND
NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL
SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE
AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING
THE MAIN SEVERE THREAT.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 407 PM CDT SUN APR 27 2014
FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN
LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL.
THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH
THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK.
WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST
KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE
TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND
OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE
CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS
STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW.
THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY
00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO
AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z
NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE
CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE
OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF
THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS
OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE
TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD
DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS
COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG
QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN
TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP
BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS
ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY
THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT
WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN
ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER
COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET
DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE
WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO
SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2
INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE.
THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND
THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED
THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE
SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO
CIRCULATE AROUND THE SYSTEM.
MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON
THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN
ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND
ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT
PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL
LOOK LIKELY.
WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER
THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A
NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY
MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO
SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF
HEADLINES ARE NEEDED.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 407 PM CDT SUN APR 27 2014
TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND
PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL
LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER
MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO
PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING
THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA
MONDAY NIGHT AND TUESDAY NIGHT.
FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN
FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL
MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY
LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN
PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS
IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND
SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND
DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID
CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY
WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN
THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT
AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND
WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE
CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS
WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY
CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL
HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE
IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE
FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE.
LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE
MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN
WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS
TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE
WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH
LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS
AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL
CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE
FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET
UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON
HOURS.
ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME
IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND
NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE
OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY
MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT
DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR
MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON
ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT
ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER
CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO
CATEGORICAL POPS OVERNIGHT.
TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON
TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY
THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL
CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL
DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR
TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL
HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C
IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL
STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85
TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST.
AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS
WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30
MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT
ANTICIPATING ANY WIND HEADLINES ATTM.
WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED
BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK.
HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL
CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN
THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH
THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE
50S EXPECTED FRIDAY...SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 643 PM CDT SUN APR 27 2014
WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH
MONDAY AFTERNOON AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL
PLAINS. WINDS 32035G45KT SHOULD SPREAD FROM WEST TO EAST TONIGHT
AND CONTINUE THROUGH MONDAY AFTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 AM MDT MONDAY FOR NEZ022-035-056>058-069.
HIGH WIND WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR
NEZ022-035-056>058-069-070.
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ023>025-
036-037-059-071-094.
WIND ADVISORY UNTIL 6 PM MDT MONDAY FOR NEZ004.
WIND ADVISORY UNTIL 7 AM CDT MONDAY FOR NEZ070.
WIND ADVISORY FROM 7 AM TO 7 PM CDT MONDAY FOR NEZ005-006-008-
009-026-027-038.
&&
$$
SYNOPSIS...CLB
SHORT TERM...BROOKS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
400 PM CDT SAT APR 26 2014
.SYNOPSIS...
ISSUED AT 358 PM CDT SAT APR 26 2014
AT 19Z...WATER VAPOR IMAGERY SHOWED A DEEP UPPER LEVEL TROUGH
ACROSS THE WESTERN CONUS...WITH A STRONG PV ANOMALY AT THE BASE OF
THE TROUGH OVER WESTERN ARIZONA. UPPER LEVEL ANALYSIS FROM 12Z
SHOWED 100+KT JET ROUNDING THE BASE OF THE TROUGH. DOWNSTREAM OF
THE TROUGH...THE RIDGE AXIS WAS FROM THE LOWER MISSISSIPPI RIVER
VALLEY...INTO THE NORTHERN PLAINS AND UP INTO THE WESTERN
NORTHWEST TERRITORIES IN CANADA. AT THE SURFACE...LOW PRESSURE WAS
OVER NORTHERN COLORADO WITH A WARM FRONT EXTENDING ACROSS NORTHERN
KANSAS. SOUTH OF THE WARM FRONT TEMPERATURES HAD WARMED INTO THE
UPPER 80S AND LOW 90S ALONG WITH BREEZY SOUTHERLY WINDS AND A GOOD
DRYLINE FROM EAST OF KHLC INTO THE OKLAHOMA PANHANDLE. TO THE
NORTH OF THE FRONT 70S AND LOW 80S WERE OBSERVED WITH SOUTHEAST
WINDS. FURTHER NORTH...A STATIONARY FRONT WAS LOCATED FROM WESTERN
SOUTH DAKOTA INTO EAST CENTRAL NEBRASKA WITH A SLIGHT WIND SHIFT
BEING DEFINED IN THE SURFACE FIELD. WINDS NORTH OF THE FRONT WERE
QUITE STRONG...WITH GUSTS OF 35KTS TO 50KTS ACROSS SOUTH DAKOTA.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 358 PM CDT SAT APR 26 2014
THE UPPER LEVEL TROUGH WILL LIFT INTO SOUTHEAST COLORADO BY 12Z
SUNDAY. MEANWHILE...THE WARM FRONT WILL LIFT NORTH THIS EVENING AS
THE SURFACE LOW SLOWLY MIGRATES EAST INTO SOUTHWEST NEBRASKA.
CURRENTLY...THE AREA IS IN THE DRY SLOT OF THE MID LEVEL FLOW AS CAN
BE SEEN FROM WATER VAPOR AS THE FETCH OF DRY AIR COMES ALL THE WAY
INTO NEBRASKA FROM THE BASE OF THE TROUGH. THE MAIN AREA OF MOISTURE
IS BEING PUSHED INTO KANSAS AND EASTERN NEBRASKA AS CAN BE SEEN BY
MID LEVEL CLOUD COVER. THIS DRY AIR WILL KEEP ANY SHOWERS/STORMS
FROM DEVELOPING NORTH OF THE WARM FRONT YET THIS AFTERNOON. AS THE
FRONT MOVES NORTH THE AREA THIS EVENING...MODELS SHOW THE WARM
SECTOR STAYING CAPPED AT LEAST UNTIL 00Z AND MUCH OF THE LOCAL AREA
STAYING CAPPED UNTIL AFTER 06Z. THE LATEST HRRR FROM 26.18Z DOES
SHOW A FEW STORMS DEVELOPING OVER EASTERN NEBRASKA AROUND 00Z. BUT
WITH THE MID LEVEL FLOW...ANYTHING THAT DEVELOPS WILL MOVE QUICKLY
NORTHEAST. IF THE FORECAST AREA WILL SEE ANY STORMS TONIGHT...WILL
NEED STORMS TO DEVELOP LOCALLY. DIDN/T REMOVE CHANCES COMPLETELY
OVERNIGHT...BUT CONFIDENCE IS NOT HIGH ON STORM DEVELOPMENT. IF
STORMS WOULD DEVELOP THIS EVENING ALONG THE WARM FRONT...SEVERE
PARAMETERS DO INDICATE THERE WOULD BE POTENTIAL FOR A FEW ORGANIZED
SUPERCELLS. AND WITH GOOD LOW LEVEL HELICITY...CAN/T COMPLETELY RULE
OUT A BRIEF ISOLATED TORNADO. HOWEVER...EVEN THOUGH SOUTHEAST AND
EASTERLY WINDS ALONG THE WARM FRONT WILL CONTINUE TO PULL MOISTURE
INTO NORTH CENTRAL NEBRASKA THIS EVENING AND OVERNIGHT.
HOWEVER...THINK SOME OF THE MODELS MAY BE A BIT ROBUST GETTING MID
TO UPPER 50 DEWPOINTS IN THESE AREAS. THE LACK OF LOW LEVEL MOISTURE
WOULD VERY LIKELY PROHIBIT ANY STORMS PRODUCING TORNADOS.
FOR SUNDAY...THE MODELS ARE FINALLY COMING INTO AGREEMENT ON THE
TRACK OF THE SYSTEM AS THEY BRING THE 500MB LOW INTO WESTERN
NEBRASKA. THERE DOES REMAIN SOME DIFFERENCES THOUGH IN THE WEST TO
EAST EXTENT AND ALTHOUGH IT IS NOT MUCH IT HAS A HIGH IMPACT ON THE
WEATHER FOR SUNDAY AND SUNDAY NIGHT. FORECAST CONFIDENCE HAS
IMPROVED...YET THERE ARE STILL CONSIDERABLE QUESTIONS. WITH THE
SURFACE LOW NOW LOOKING MORE LIKELY TO TRACK JUST NORTH OF THE
NEBRASKA-KANSAS BORDER SUNDAY AND CENTERED IN THE KLBF/KMCK AREA AT
00Z PRECIPITATION CHANCES WILL INCREASE THROUGH THE DAY...MAINLY ON
THE NORTHERN AND WESTERN PERIPHERIES OF THE LOW. SO DID INCREASE
CHANCES ACROSS NORTHERN NEBRASKA AND THE PANHANDLE. ON THE BACK SIDE
OF THE LOW...WINDS WILL STRENGTHEN CONSIDERABLY BY LATE AFTERNOON.
CURRENT FORECAST FOLLOWS A SLOWER EASTERLY PROGRESSION OF THE
SURFACE LOW WHICH KEEPS THE WINDS FROM INCREASING UNTIL AFTER 00Z.
HOWEVER QUICKER MOVEMENT COULD MEAN STRONG WINDS OF 30KTS SUSTAINED
EARLIER. WILL LET ONE MORE FORECAST CYCLE GO TO ALLOW MODELS TO COME
INTO BETTER AGREEMENT BEFORE DECIDING ON ANY HEADLINES FOR WINDS DUE
TO SOME UNCERTAINTY.
IN TERMS OF THUNDERSTORMS FOR SUNDAY...INSTABILITY ISN/T TERRIBLY
HIGH...WITH MUCAPE VALUES OF 100J/KG TO 1500 J/KG...BUT WITH STEEP
LOW LEVEL LAPSE RATES AND SUFFICIENT SHEAR CAN/T DISCOUNT ANY STORMS
AS WELL AS ANY STORMS BECOMING SEVERE. THE PRIMARY AREAS OF CONCERN
WILL BE OVER NORTH CENTRAL NEBRASKA /EAST OF HIGHWAY 183/ WHERE
THERE WILL BE MORE MOISTURE. SOMETHING TO CONSIDER WATCHING THROUGH
THE DAY WILL BE IF ANY CONVECTION GOES UP ON THE WESTERN EDGE OF THE
SURFACE LOW AND THE INVERTED TROUGH ACROSS THE WESTERN SANDHILLS.
THERE IS ONLY LOW INSTABILITY BUT WITH LOW LEVEL TURNING IN THE
VICINITY OF THE BOUNDARY...COULD CAUSE ANY CONVECTION TO SPIN.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 358 PM CDT SAT APR 26 2014
MID RANGE...SUNDAY NIGHT THROUGH TUESDAY...A PERSISTENT...SLOW
MOVING UPPER LEVEL LOW...WILL MEANDER FROM SOUTHWESTERN TO
NORTHEASTERN NEBRASKA DURING THE PERIOD...EVENTUALLY MOVING EAST OF
THE STATE TUESDAY NIGHT. A PLETHORA OF WEATHER WILL OCCUR ON THE
BACK SIDE OF THIS FEATURE AS IT MIGRATES ACROSS WESTERN AND NORTH
CENTRAL NEBRASKA SUNDAY NIGHT INTO TUESDAY AND THIS WILL BE THE
MAIN FORECASTING CHALLENGE FOR THE BEGINNING OF THE
WEEK.
SUNDAY NIGHT INTO MONDAY...FOR THESE PERIODS...THE THREAT FOR WINTRY
WEATHER IN THE NORTHWEST SUNDAY NIGHT THEN WIND POTENTIAL SUNDAY
NIGHT INTO MONDAY ARE THE MAIN FORECAST CONCERNS. SUNDAY NIGHT INTO
MONDAY...AN INTENSE UPPER LEVEL LOW AND STRONG SURFACE LOW...WILL
MEANDER SLOWLY ACROSS NEBRASKA. ON THE BACK SIDE OF THIS FEATURE
SUNDAY NIGHT INTO MONDAY...A NICE DEFORMATION BAND OF PCPN IS
EXPECTED TO DEVELOP ALONG WITH STRONG WINDS WHICH WILL TRANSITION
FROM WEST TO EAST SUNDAY NIGHT INTO MONDAY. HOW FAR EAST THE STRONG
WINDS DEVELOP SUNDAY NIGHT INTO MONDAY IS STILL UP IN THE AIR SOME.
MORE ON THAT TWO PARAGRAPHS BELOW.
EVEN AT ONLY 36 TO 48 HOURS OUT...THE LATEST NAM...GFS
AND ECMWF SOLNS ARE STILL HAVING ISSUES WITH THE TRACK OF THE H5 LOW
AND TRACK OF THE SURFACE LOW. THE NAM LIFTS THE H5 LOW FROM AROUND
ARNOLD NEBRASKA TO NORTH OF ONEILL NEBRASKA FROM 00Z TO 12Z MONDAY.
THE GFS LIFTS THE LOW FROM FAR EASTERN FRONTIER COUNTY TO NEAR
SPRINGVIEW NEBRASKA DURING THE SAME PERIOD...WHILE THE ECMWF LIFTS
THE LOW FROM WESTERN LINCOLN COUNTY TO NEAR VALENTINE. NO
SURPRISE...THE NAM IS COLDEST AT H85 WITH SUB FREEZING TEMPS IN THE
NORTHWESTERN FORECAST AREA OVERNIGHT SUNDAY NIGHT...WHICH WOULD
FAVOR SNOW FOR PRECIPITATION TYPE. THE GFS AND ECMWF ARE
CONSIDERABLY WARMER WITH H85 TEMPS OF 2 TO 3 C AT 12Z MONDAY
MORNING...FAVORING ALL RAIN OR POSSIBLE RAIN SNOW MIX. ATTM...WILL
GO WITH A RAIN/SNOW MIX FOR PTYPE OVERNIGHT SUNDAY NIGHT IN THE FAR
NORTHWEST GIVEN THE TRACK DIFFERENCES IN THE UPPER LEVEL SYSTEM.
ATTM...WITH TEMPERATURES HOVERING IN THE MIDDLE 30S SUNDAY NIGHT IN
THE FAR NORTHWEST...NOT EXPECTING ANY ACCUMS ATTM.
THEN THERE IS THE WIND THREAT ON THE BACK SIDE OF THE EXITING
SYSTEM. FOR SUNDAY NIGHT...THE ECMWF AND GFS SOLNS ARE IN GENERAL
AGREEMENT WITH LOCATION OF THE SURFACE LOW AT 12Z MONDAY...IE OVER
THE FAR NERN CWA...WHILE THE NAM12 HAS THE LOW NEAR SIOUX CITY IOWA.
NO SURPRISE...THERE ARE SIGNIFICANT DIFFERENCES IN WIND SPEEDS
BETWEEN THE MET AND MAV GUIDANCE FOR SUNDAY NIGHT. IF THE MET
VERIFIES...WE WOULD PROBABLY NEED SOME SORT OF WIND HEADLINE FOR AT
LEAST THE WESTERN HALF OF THE FORECAST AREA SUNDAY NIGHT. WITH THE
GFS SOLN...ANY WIND ADVISORY IF NEEDED WOULD BE CONFINED TO THE FAR
SOUTHWESTERN AND EASTERN PANHANDLE COUNTIES. THIS LEADS TO THE
HEADLINE DILEMMA FOR SUNDAY NIGHT...WINTER HEADLINES IN THE NERN
PANHANDLE OR WIND HEADLINES. GIVEN THE DISCREPANCIES IN THE LOCATION
OF THE SURFACE LOW AND UPPER LEVEL LOW...WILL HOLD OFF ON HEADLINES
FOR SUNDAY NIGHT AND WAIT FOR ANOTHER MODEL RUN TO COME IN.
ON MONDAY...THE SURFACE LOW WILL MIGRATE EAST OF THE UPPER LEVEL LOW
INTO EASTERN NEBRASKA. AT THE SAME TIME...A DOWNSTREAM BLOCKING
RIDGE WILL LIMIT ANY EWD MOVEMENT OF THE H5 LOW...WHICH WILL REMAIN
IN PLACE ACROSS CENTRAL NEBRASKA. WRAP AROUND PCPN WILL CONTINUE
PARTICULARLY OVER NORTH CENTRAL AND NORTHWESTERN NEBRASKA AS
FAVORABLE ISENTROPIC LIFT CONTINUES. IN ADDITION TO COLD RAIN...VERY
WINDY CONDITIONS WILL DEVELOP ESPECIALLY ACROSS THE WESTERN 2/3RDS
OF THE FORECAST AREA. AGAIN...LIKE SUNDAY NIGHT...WIND SPEEDS WILL
BE HIGHLY DEPENDENT ON WHERE THE SURFACE LOW SETS UP ON MONDAY
AFTERNOON. BETTER CONFIDENCE EXISTS IN THE WIND FORECAST FOR MONDAY
AS THE MODELS HAVE THE SURFACE LOW OVER NERN NEBRASKA BY 00Z
TUESDAY.
MONDAY NIGHT AND TUESDAY...FROM MONDAY NIGHT INTO TUESDAY
AFTERNOON...THE UPPER LEVEL LOW WILL CRAWL SLOWLY EAST INTO THE MID
MISSISSIPPI VALLEY. ON MONDAY NIGHT...A STRONG SHORTWAVE WILL ROTATE
AROUND THE WESTERN PERIPHERY OF THE CLOSED LOW BRINGING ANOTHER SHOT
OF RAIN AND OR SNOW SHOWERS TO THE FORECAST AREA. THE LATEST ECMWF
AND GFS SOLNS ARE INDICATING ENOUGH COLD AIR FOR AT LEAST A RAIN
SNOW MIX OVERNIGHT MONDAY NIGHT INTO TUESDAY MORNING ACROSS PORTIONS
OF NORTH CENTRAL NEBRASKA AND WILL INSERT THIS IN THE UPDATED
FORECAST. WINDS WILL BE AN ISSUE ONCE AGAIN ON TUESDAY 40+ KT H85
WINDS WILL BE PRESENT ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
TEMPERATURES TUESDAY WILL BE COOLER AS WELL AND IS SHAPING UP TO BE
THE COOLEST DAY OF THE PERIOD ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA AS H85 TEMPS DROP DOWN TO -2C TO 5C. ACROSS NORTH CENTRAL
NEBRASKA...TEMPERATURES WILL BE COOL ENOUGH TO FACILITATE AT LEAST A
RAIN SNOW MIX TROUGH THE MORNING HOURS AND WILL INCLUDE THIS MENTION
IN THE FORECAST.
TUESDAY NIGHT AND BEYOND...UPPER LOW PRESSURE WILL MEANDER OVER
EASTERN IOWA BEFORE LIFTING INTO THE WESTERN GREAT LAKES ON THURSDAY
INTO THURSDAY NIGHT. THE THREAT FOR LIGHT PRECIPITATION WILL
CONTINUE THROUGH THURSDAY WITH A LIMITED CHANCE FOR RAIN OR SNOW
OVER NORTHERN NEBRASKA DURING THE OVERNIGHT AND EARLY MORNING HOURS.
WILL KEEP POPS SLIGHT AS MOISTURE WILL BE FAIRLY LIMITED AS WE HEAD
INTO THE MIDDLE AND END OF THE WEEK. TEMPERATURES WILL SLOWLY
MODERATE INTO THE 50S FOR WEDNESDAY AND THURSDAY...APPROACHING THE
LOWER 60S FOR FRIDAY AND SATURDAY AS THE UPPER LEVEL LOW IS ABSORBED
BY THE NRN STREAM AND LIFTED INTO EASTERN CANADA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 127 PM CDT SAT APR 26 2014
A SURFACE LOW OVER NORTHEAST COLORADO WILL SLOWLY MOVE EASTWARD
THROUGH SUNDAY AFTERNOON. AS THIS OCCURS...BREEZY SOUTHEAST TO
EASTERLY WINDS WILL OCCUR FOR MUCH OF THE NIGHT HOURS FOR PORTIONS
OF CENTRAL INTO NORTH CENTRAL NEBRASKA. TO THE WEST...LIGHTER
WINDS WILL BE OBSERVED IN THE REGION OF THE LOW...AND UP THROUGH
THE PANHANDLE. WINDS WILL INCREASE IN THE WESTERN AREAS SUNDAY
AFTERNOON AS THE LOW DRIFTS EAST. THERE WILL BE CHANCES FOR
THUNDERSTORMS LATER THIS EVENING AND OVERNIGHT...MAINLY ACROSS THE
PANHANDLE AND NORTH CENTRAL NEBRASKA.
&&
.FIRE WEATHER...
ISSUED AT 358 PM CDT SAT APR 26 2014
FIRE WEATHER CONCERNS WILL REMAIN HIGH THIS EVENING AS THE WARM
FRONT LIFTS NORTH TO KEEP DRY AND BREEZY CONDITIONS ACROSS FIRE ZONE
210. CONDITIONS WILL IMPROVE AROUND MID EVENING AS TEMPERATURES FALL
AND HUMIDITY STARTS TO RECOVER. TEMPERATURES WILL BE ON THE
DOWNSLIDE FOR THE NEXT WEEK AS A LARGE STORM SYSTEM SITS OVER THE
REGION. MUCH OF THE WEEK WILL SEE HIGHS IN THE 40S AND 50S...WITH
PERIODIC CHANCES FOR RAIN...AND EVEN A CHANCE FOR SNOW IN SOME
AREAS. HOWEVER...THIS SYSTEM WILL ALSO BRING AN EXTENDED PERIOD OF
STRONG WINDS. IT LOOKS LIKELY FOR STRONG WINDS OF 30 TO 40 MPH TO BE
POSSIBLE ALMOST DAILY IN PARTS OF THE AREA THROUGH THURSDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR NEZ210.
&&
$$
SYNOPSIS...BROOKS
SHORT TERM...BROOKS
LONG TERM...CLB
AVIATION...BROOKS
FIRE WEATHER...BROOKS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
323 PM CDT SAT APR 26 2014
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 322 PM CDT SAT APR 26 2014
STORM SYSTEM IS DEEPENING AND BEGINNING TO AFFECT THE PLAINS.
SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES DEEPENING 500MB TROUGH
IN THE WESTERN US...WITH 500MB HEIGHT FALLS UP TO 170M CENTERED IN
THE CA/NV/AZ BORDER REGION...AND WITH SOUTHWESTERLY UPPER-LEVEL FLOW
ACROSS THE CENTRAL US. 300MB JET UP TO 130KT WAS STILL ON THE WEST
SIDE OF THE TROUGH...WITH 105-115KT AROUND THE BASE AND TOWARD THE
EAST OF THE TROUGH AXIS. 850MB MOISTURE AT 12Z WAS FOCUSED IN TWO
SEPARATE AREAS...ONE RIGHT ALONG THE GULF COAST...AND FROM WEST TX
THROUGH OK INTO SOUTHWEST MO...WITH 850MB WINDS UP TO AROUND 50KT
TRANSPORTING MOISTURE NORTHWARD INTO THE CENTRAL PLAINS. WEAK 850MB
FRONT WAS NOTED FROM LOW IN NORTHERN WY/SOUTHERN MT THROUGH NEB INTO
NORTHERN MO. 700-500MB DELTA-T OF 20-24C WAS NOTED ACROSS THE
PLAINS...WITH THE HIGHEST VALUES ALONG THE HIGH PLAINS TOWARD
OK/WEST TX. SURFACE LOW AT 19Z WAS CENTERED IN NORTHEAST CO...WITH
WIND SHIFT WARM FRONT EXTENDING ACROSS NEB NEAR THE PLATTE RIVER
TOWARD WEST CENTRAL TO SOUTHEAST IA...AND WITH MOISTURE GRADIENT
NEAR THE KS/NE BORDER AS UPPER 50S DEWPOINTS HAD ADVANCED INTO
NORTHEAST TO CENTRAL KS.
MAIN FORECAST CONCERN IS VERY CONDITIONAL CONVECTIVE POTENTIAL THIS
EVENING...CONVECTION ON CWA MARGINS TONIGHT...AND MORE WIDESPREAD
CONVECTIVE POTENTIAL TOMORROW. RAP CONTINUES TO MIX OUT PROFILE
DEEPLY BY 23-00Z AND DEVELOP VERY HIGH-BASED CONVECTION...WHILE HRRR
HAS TRENDED FROM PRODUCING A CELL OR TWO THIS EVENING TO NEARLY
DRY...AND 12Z 4KM WRF KEPT THE AREA MAINLY DRY THROUGH TONIGHT.
MODELS THAT DO PRODUCE SOME CONVECTION LATER TONIGHT ARE DOING SO
JUST IN OUR NORTHEASTERNMOST CWA. HAVE KEPT A VERY LOW-CONFIDENCE
SMALL AREA OF POPS ADVANCING FROM SOUTHEAST NEB TO NEAR THE I-80
CORRIDOR IN THE EARLY EVENING...THEN SLIGHT CHANCES IN THE NORTHERN
CWA THE REST OF THE EVENING BEFORE FOCUSING ON THE NORTHEASTERNMOST
FRINGE FOR TONIGHT.
AS UPPER LOW EJECTS ACROSS THE ROCKIES TOWARD KS/NEB ON
SUNDAY...WITH INCREASING MOISTURE TRANSPORT INTO THE CENTRAL
PLAINS...SHOULD SEE CONVECTION DEVELOP BY MIDDAY IN EASTERN
NEB...SPREADING INTO WESTERN IA QUICKLY. WITH ABUNDANT SHEAR ACROSS
THE AREA...POTENTIAL FOR SEVERE WEATHER DOES EXIST FOR ANY
CONVECTION AS IT GETS GOING ACROSS THE AREA FROM MIDDAY THROUGH THE
AFTERNOON. ALSO...AM THINKING THAT THERE WILL BE ENOUGH OF A BREAK
IN CONVECTION TONIGHT THROUGH MUCH OF THE MORNING THAT AIRMASS WILL
HAVE TIME TO SUFFICIENTLY DESTABILIZE AT LEAST IN THE SOUTHERN HALF
OF THE CWA IF NOT ACROSS THE ENTIRE CWA. WITH SUCH STRONG UPPER-
LEVEL SUPPORT THOUGH...CONVECTION WILL BE QUITE WIDESPREAD...AND
THUS CONVECTIVE MODE/THREATS WILL BE MESSY AND COMPLICATED. WITH
VERY STRONG DEEP-LAYER SHEAR...ROTATING LARGE HAIL WILL BE A
THREAT...AS WELL AS POTENTIAL FOR DAMAGING WIND GUSTS. ENOUGH 0-1KM
SHEAR EXISTS FOR A TORNADO THREAT FOR STORMS IF THEY CAN STAND
ALONE...THOUGH WORTH NOTING THAT HODOGRAPHS ARE MORE STRAIGHT THAN
CURVED IN MOST MODEL SOLUTIONS. STORMS WILL MOVE FAIRLY RAPIDLY
TOWARD THE NORTH-NORTHEAST...AND AS THE SURFACE LOW PUSHES
EASTWARD...SHOULD EXIT THE CWA THROUGH THE LATE AFTERNOON TO EARLY
EVENING HOURS...LEAVING CWA IN DRY SLOT FOR THE REST OF THE NIGHT
AND THROUGH MUCH OF MONDAY.
ONCE UPPER LOW ADVANCES INTO NEB...IT IS PROGGED TO STALL THROUGH
MONDAY...THEN FILL AND DRIFT EASTWARD INTO IOWA ON TUESDAY.
PRECIPITATION WILL RETURN TO THE CWA IN THE WRAPAROUND AREA
BEGINNING LATE MONDAY...EXPANDING ACROSS THE CWA THROUGH MONDAY
NIGHT AND TUESDAY...WITH AT LEAST OCCASIONAL LIGHT PRECIPITATION
CONTINUING THROUGH THURSDAY AS CWA REMAINS IN COOL CYCLONIC FLOW
BEHIND THE UPPER LOW. REMOVED THUNDER MENTION FROM ANY
PRECIPITATION FROM MONDAY EVENING ONWARD...AS AIRMASS REALLY
STABILIZES ON THE COLD SIDE OF THE LOW. TEMPERATURES WILL BE MUCH
COOLER BEHIND THE LOW...WITH TEMPERATURES ON MONDAY DOWN INTO THE
50S AND LIKELY STRUGGLING TO EVEN REACH 50 ON TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 322 PM CDT SAT APR 26 2014
GENERALLY COOLER AND UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH
NEXT WEEKEND. HAVE KEPT SPECIFIC POP MENTIONS OUT OF MOST PERIODS
FOR NOW...BUT THINK THERE IS A DECENT CHANCE TO GET AT LEAST LIGHT
PRECIPITATION IN AT LEAST SOME PART OF THE CWA ON SOME PERIOD. FOR
NOW...HAVE INCREASED CLOUDS A BIT. ALSO KEPT TEMPERATURES ON THE
COOL SIDE...WITH TEMPERATURES CONTINUING IN THE 50S THROUGH THURSDAY
BEFORE POSSIBLY REBOUNDING INTO THE 60S IN AT LEAST PART OF THE AREA
BY FRIDAY OR SATURDAY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1221 PM CDT SAT APR 26 2014
WILL LEAVE KOMA/KLNK TAF SITES DRY THROUGH THE PERIOD. ANY
TSRA DEVELOPMENT THIS AFTN/EVNG WOULD BE TO ISOLATED TO INCLUDE
AND AFTER THIS TIME THE ACTIVITY WILL LIKELY BE NORTH OF THE TAF
SITES. THERE IS AN INCREASE THREAT OF SHRA/TSRA SUN MORNING AT
THESE TAF SITES BUT TIMING AND COVERAGE CONCERNS PRECLUDE ANY
MENTION AT THIS TIME. FOR KOFK WE WILL INCLUDE SOME SHOWERS SUN
MORNING. OTHERWISE WE WILL SEEM MVFR CIGS MOVE INTO ALL TAFS AFTER
06Z TONIGHT AND MAY LOWER TO IFR AT KOFK BY SUN MORNING. WE WILL
ALSO LIKELY SEE SOME MVFR VISBY AS WELL WITH INCREASING MOISTURE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...MAYES
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1225 PM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 1102 AM CDT SAT APR 26 2014
THE 12Z UPPER AIR ANALYSIS AND MODELS DID LITTLE IN PROVIDING A
DECISIVE ANSWER AS TO THE THREAT OF SURFACED-BASED CONVECTIVE
INITIATION LATER THIS AFTERNOON. THE UPPER AIR ANALYSIS INDICATED
A WELL DEFINED EML EXTNG ACROSS THE PLAINS FROM THE DAKOTAS TO TX
WITH 700 TO 500 MB DELTA-T VALUES >20 C WITH KOMA/KTOP ON THE ERN
EDGE OF THIS CAPPING INVERSION AT 12Z. AT 500 MB THE MAIN STORM
SYSTEM WAS STILL IN SRN NV/CA ASSOCIATED WITH A 170 M HEIGHT FALL
AT LAS VEGAS. DOWNSTREAM HEIGHT FALLS WERE NOTED ACROSS THE HIGH
PLAINS FROM KRAP TO KDDC TO KAMA OF 10 TO 30 M. THE LOW-LEVEL
MOISTURE PROFILE AT 850 MB WAS STILL RATHER NARROW BUT DID SHOW AN
AXIS OF >+10 C FROM WRN OK INTO SW TX.
MODELS ARE INSISTENT THAT A STRONG AIRMASS ADJUSTMENT WILL TAKE
PLACE TODAY WITH THIS SRN PLAINS MOISTURE MOVING INTO SE NEB BY
LATE THIS AFTERNOON. ALTHOUGH THIS MAY BE OVERDONE TO SOME
DEGREE...COMPARISON OF THE 15Z OBS TO 3 HOUR FORECAST FROM THE NAM
INDICATES GOOD AGREEMENT. AS STRONG MIXING CONTINUES THROUGH THE
AFTERNOON WE EXPECT TO SEE A BIT MORE OF A GAP IN THE FORECAST AND
OBSERVED...BUT NEVERTHELESS LOWER TO MID 50S SHOULD MAKE IT INTO
NE KS/SE NEB BY LATE AFTERNOON. GIVEN THE SEASONABLY STEEP MID
TROPOSHERIC LAPSE RATES THIS WILL CREATE MLCAPE OF 1500-2000 J/KG
BY 00Z. MODELS...ESPECIALLY THE GFS...ADVERTISE THE 10-20 M HEIGHT
FALLS OVER-SPREADING ERN NEB THIS AFTERNOON. THIS...ALONG WITH THE
CWA RESIDING IN THE LEFT EXIT REGION OF THE 65 KT H3 JET SAMPLED
BY THE 12Z UPPER AIR ANALYSIS OVER WRN NEB/CO WILL AT LEAST CREATE
A LARGE-SCALE ENVIRONMENT ISN`T OVERALY DETRIMENTAL TO CONVECTION
INITIATION. POINT FORECAST SOUNDINGS FROM THE NAM CONT TO INSIST
THAT THE EML WILL HOLD AND NO SURFACE-BASED CONVECTION WILL OCCUR.
GIVEN THE MARGINAL MOISTURE AND LACK OF LARGE-SCALE ASCENT THIS
ISN`T OUT OF THE QUESTION. SOME OF THE HIGH-RES MODELS /I.E. HRRR-
RAP/ AS WELL AS THE OPERATIONAL GFS INDICATE THAT CI WILL OCCUR.
THE POINT FORECAST SOUNDINGS FROM THE RAP APPEAR TO OVER MIX THE
BOUNDARY LAYER LEADING TO A REDUCTION IN THE CAP THOUGH. HAVING
SAID ALL THIS WE WILL MAINTAIN SOME SCHC FOR SOME STORMS THIS
EVENING IN THE SOUTH...OTHERWISE IT STILL APPEARS THAT THE LOW-
LEVEL JET WILL INCREASE ACTIVITY IN THE NORTH LATE THIS EVENING.
IF STORMS DO DEVELOP 23-01Z IN THE SW ALL MODES OF SEVERE WEATHER
STILL APPEAR POSSIBLE OTHERWISE THE STORMS IN THE NORTH SHOULD
HAVE A MARGINAL HAIL THREAT.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 334 AM CDT SAT APR 26 2014
POTENTIAL FOR SEVERE THUNDERSTORMS THROUGH SUNDAY NIGHT REMAINS THE
PRIMARY FORECAST CHALLENGE.
SEVERAL BOUTS OF SEVERE STORMS ARE POSSIBLE TODAY AND SUNDAY IN
PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA...BUT THERE IS STILL
WIDE VARIATION IN POSSIBLE SCENARIOS IN TIMING/LOCATION OF HIGHEST
PROBABILITIES. UPPER TROUGH MOVING THROUGH CENTRAL CALIFORNIA THIS
MORNING WILL MOVE THROUGH THE ROCKIES LATER TONIGHT AND EMERGE IN
THE HIGH PLAINS SUNDAY AS A CLOSED LOW...WITH SURFACE LOW POSITION
SETTING UP IN NORTHEAST QUADRANT OF UPPER LOW. NAM AND GFS ARE A
COUPLE HUNDRED MILES APART IN SURFACE LOW POSITION AT 18Z
SUNDAY...WITH ECMWF MORE IN LINE WITH NAM. HAVE FOLLOWED ECMWF MORE
CLOSELY THAN OTHER MODELS IN THIS REGARD.
SURFACE DEW POINTS ARE EXPECTED TO INCREASE INTO THE 50S LATER TODAY
AS PRESSURES FALL IN THE HIGH PLAINS UNDER INCREASING DIFFLUENT FLOW
ALOFT AHEAD OF UPPER WAVE. 50S DEW POINTS WERE SHOWING UP IN THE
TEXAS PANHANDLE THIS MORNING...IN LINE WITH 6-HOUR FORECASTS OF 00Z
MODELS...AND WILL ADVECT THROUGH KANSAS INTO SOUTHEAST NEBRASKA THIS
AFTERNOON. MEANWHILE SURFACE TEMPERATURES WILL CLIMB INTO THE LOWER
80S...YIELDING SURFACE-BASED CAPE VALUES CLOSE TO 1200 J/KG BY 00Z
IN SOUTHEAST NEBRASKA. HOWEVER FORECAST SOUNDINGS AND EXTRAPOLATION
OF WARM MID LEVEL AIR CURRENTLY IN WEST TEXAS AND NEW MEXICO SUGGEST
CAPPING WILL BE STRONG THROUGH THE AFTERNOON ACROSS ALL OF OUR AREA.
WHILE SOME MODEL SOLUTIONS POP A FEW SHOWERS/STORMS BY LATE
AFTERNOON...FEEL CAPPING WILL HOLD UNTIL LATER IN THE EVENING WHEN
LOW LEVEL JET KICKS IN. BROAD AREA OF MOST-UNSTABLE CAPE NEAR 2000
J/KG AS PER ECMWF WILL ADVECT NORTH FROM CENTRAL KANSAS INTO EASTERN
NEBRASKA BY 06Z. BULK SHEAR CLOSE TO 40KT WILL ALSO DEVELOP AS
STRONGER FLOW AND COOLER TEMPERATURES AT MID LEVELS SPREAD INTO THE
PLAINS. EXPECT CONVECTIVE INITIATION TO OCCUR IN SOUTH CENTRAL
NEBRASKA DURING THE EVENING AND SPREAD/DEVELOP EAST/NORTHEAST INTO
OUR AREA BY LATE EVENING. IF STORMS DO FIRE HERE...SURFACE WARM
FRONT WILL COME INTO PLAY...ENHANCING LOW LEVEL SHEAR/HELICITY FOR
AN ENHANCED RISK OF POTENTIAL TORNADIC STORMS...GENERALLY IN AREAS
FROM ALBION TO COLUMBUS TO LINCOLN AND SOUTHWEST.
A SECOND AREA OF INITIATION AROUND OR AFTER MIDNIGHT APPEARS LIKELY
ON NOSE OF LOW LEVEL JET RIDING UP AND OVER SURFACE FRONT...FOCUSING
ON AREAS FROM NORTHEAST NEBRASKA INTO WEST CENTRAL IOWA. THESE
STORMS WILL BE ELEVATED WITH CAPE NEAR 1500 J/KG AND SHEAR OF 40KT
TO WORK WITH...THUS LARGE HAIL WILL BE POSSIBLE.
BY SUNDAY MORNING...A MID LEVEL WAVE ROTATING NORTHEAST AROUND UPPER
LOW SPARKING CONVECTION IN KANSAS OVERNIGHT WILL SWING INTO EASTERN
NEBRASKA. EXPECT MORE STORMS TO INVADE SOUTHEAST NEBRASKA EARLY IN
THE DAY AND SPREAD NORTH THROUGH THE MORNING. INSTABILITY SHOULD BE
WANING DURING THE MORNING...BUT SHEAR INCREASING. SO DESPITE A
NORMAL LULL IN POTENTIAL SEVERE DURING THE MORNING
HOURS...COMBINATION OF SHEAR/INSTABILITY WILL STILL SUPPORT AT LEAST
SEVERE HAIL POTENTIAL IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
BY EARLY SUNDAY AFTERNOON...SURFACE DRYLINE IS FORECAST TO BE
APPROACHING OUR SOUTHWEST CWA AND ROTATING EAST/NORTHEAST TOWARD THE
MISSOURI RIVER BY LATE IN THE AFTERNOON OR EARLY EVENING. MORNING
CONVECTION WILL PLAY A ROLE IN RECOVERY OF ATMOSPHERE AHEAD OF THE
DRYLINE...WITH ECMWF SHOWING MOST-UNSTABLE CAPES DROPPING TO BELOW
1000 J/KG. BUT BULK SHEAR VALUES WILL STILL BE HIGH...AND ENHANCED
LOW LEVEL SHEAR NEAR WARM FRONT/DRYLINE TRIPLE POINT LOOKS TO SET UP
NEAR OR NORTH OF THE OMAHA METRO AREA BY 00Z. SO EXPECT EITHER A
STRENGTHENING OF ONGOING CONVECTION OR NEW CONVECTION SUNDAY
AFTERNOON IN AN ARC FROM NORTHEAST NEBRASKA INTO EAST CENTRAL
NEBRASKA AND SOUTHWEST IOWA...WITH WIND/HAIL PRIMARY SEVERE
POTENTIAL...AND A TORNADO POSSIBILITY NEAR WARM FRONT/DRYLINE
INTERSECTION NEAR/NORTH OF OMAHA AND SOUTHEAST THROUGH SOUTHWEST
IOWA.
THIS CONVECTION IS EXPECTED TO ROTATE NORTHEAST SUNDAY EVENING AND
SHOULD BE OUT OF OUR AREA SHORTLY AFTER MIDNIGHT. MEANWHILE UPPER
LOW WILL BE DRIFTING EAST SUNDAY NIGHT INTO MONDAY...BUT SHOULD
REMAIN WEST OF THE CWA. ECMWF KEEPS MOST OF OUR CWA DRY MONDAY...BUT
COLD POOL ALOFT WILL ENHANCE LAPSE RATES...SO WILL LIKELY SEE
SCATTERED SHOWERS/STORMS POPPING MONDAY AFTERNOON. SEVERE THREAT
THEN SHOULD BE MINIMAL.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 AM CDT SAT APR 26 2014
SPEED OF UPPER LOW DRIFTING THROUGH THE PLAINS WILL BE THE PRIMARY
CHALLENGE FOR NEXT WEEK...AND WILL BRING COOLER TEMPERATURES AND OFF-
AND-ON SHOWER CHANCES AT LEAST THROUGH THURSDAY. TUESDAY APPEARS TO
BE THE MOST LIKELY TIME OF WIDESPREAD SHOWERS AS UPPER LOW MOVES
INTO IOWA/MISSOURI AND SIGNIFICANT WAVE ROTATES AROUND THE LOW.
OTHERWISE WILL HAVE AT LEAST SMALL POPS EACH DAY/NIGHT THROUGH
THURSDAY. HIGH TEMPERATURES THROUGH THE WEEK WILL AVERAGE IN THE 50S
WITH A LITTLE WARMER WEATHER RETURNING FRIDAY AS UPPER LOW EXITS
EAST.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1221 PM CDT SAT APR 26 2014
WILL LEAVE KOMA/KLNK TAF SITES DRY THROUGH THE PERIOD. ANY
TSRA DEVELOPMENT THIS AFTN/EVNG WOULD BE TO ISOLATED TO INCLUDE
AND AFTER THIS TIME THE ACTIVITY WILL LIKELY BE NORTH OF THE TAF
SITES. THERE IS AN INCREASE THREAT OF SHRA/TSRA SUN MORNING AT
THESE TAF SITES BY TIMING AND COVERAGE CONCERNS PRECLUDE ANY
MENTION AT THIS TIME. FOR KOFK WE WILL INCLUDE SOME SHOWERS SUN
MORNING. OTHERWISE WE WILL SEEM MVFR CIGS MOVE INTO ALL TAFS AFTER
06Z TONIGHT AND MAY LOWER TO IFR AT KOFK BY SUN MORNING. WE WILL
ALSO LIKELY SEE SOME MVFR VISBY AS WELL WITH INCREASING MOISTURE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...BOUSTEAD
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1125 AM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 1102 AM CDT SAT APR 26 2014
THE 12Z UPPER AIR ANALYSIS AND MODELS DID LITTLE IN PROVIDING A
DECISIVE ANSWER AS TO THE THREAT OF SURFACED-BASED CONVECTIVE
INITIATION LATER THIS AFTERNOON. THE UPPER AIR ANALYSIS INDICATED
A WELL DEFINED EML EXTNG ACROSS THE PLAINS FROM THE DAKOTAS TO TX
WITH 700 TO 500 MB DELTA-T VALUES >20 C WITH KOMA/KTOP ON THE ERN
EDGE OF THIS CAPPING INVERSION AT 12Z. AT 500 MB THE MAIN STORM
SYSTEM WAS STILL IN SRN NV/CA ASSOCIATED WITH A 170 M HEIGHT FALL
AT LAS VEGAS. DOWNSTREAM HEIGHT FALLS WERE NOTED ACROSS THE HIGH
PLAINS FROM KRAP TO KDDC TO KAMA OF 10 TO 30 M. THE LOW-LEVEL
MOISTURE PROFILE AT 850 MB WAS STILL RATHER NARROW BUT DID SHOW AN
AXIS OF >+10 C FROM WRN OK INTO SW TX.
MODELS ARE INSISTENT THAT A STRONG AIRMASS ADJUSTMENT WILL TAKE
PLACE TODAY WITH THIS SRN PLAINS MOISTURE MOVING INTO SE NEB BY
LATE THIS AFTERNOON. ALTHOUGH THIS MAY BE OVERDONE TO SOME
DEGREE...COMPARISON OF THE 15Z OBS TO 3 HOUR FORECAST FROM THE NAM
INDICATES GOOD AGREEMENT. AS STRONG MIXING CONTINUES THROUGH THE
AFTERNOON WE EXPECT TO SEE A BIT MORE OF A GAP IN THE FORECAST AND
OBSERVED...BUT NEVERTHELESS LOWER TO MID 50S SHOULD MAKE IT INTO
NE KS/SE NEB BY LATE AFTERNOON. GIVEN THE SEASONABLY STEEP MID
TROPOSHERIC LAPSE RATES THIS WILL CREATE MLCAPE OF 1500-2000 J/KG
BY 00Z. MODELS...ESPECIALLY THE GFS...ADVERTISE THE 10-20 M HEIGHT
FALLS OVER-SPREADING ERN NEB THIS AFTERNOON. THIS...ALONG WITH THE
CWA RESIDING IN THE LEFT EXIT REGION OF THE 65 KT H3 JET SAMPLED
BY THE 12Z UPPER AIR ANALYSIS OVER WRN NEB/CO WILL AT LEAST CREATE
A LARGE-SCALE ENVIRONMENT ISN`T OVERALY DETRIMENTAL TO CONVECTION
INITIATION. POINT FORECAST SOUNDINGS FROM THE NAM CONT TO INSIST
THAT THE EML WILL HOLD AND NO SURFACE-BASED CONVECTION WILL OCCUR.
GIVEN THE MARGINAL MOISTURE AND LACK OF LARGE-SCALE ASCENT THIS
ISN`T OUT OF THE QUESTION. SOME OF THE HIGH-RES MODELS /I.E. HRRR-
RAP/ AS WELL AS THE OPERATIONAL GFS INDICATE THAT CI WILL OCCUR.
THE POINT FORECAST SOUNDINGS FROM THE RAP APPEAR TO OVER MIX THE
BOUNDARY LAYER LEADING TO A REDUCTION IN THE CAP THOUGH. HAVING
SAID ALL THIS WE WILL MAINTAIN SOME SCHC FOR SOME STORMS THIS
EVENING IN THE SOUTH...OTHERWISE IT STILL APPEARS THAT THE LOW-
LEVEL JET WILL INCREASE ACTIVITY IN THE NORTH LATE THIS EVENING.
IF STORMS DO DEVELOP 23-01Z IN THE SW ALL MODES OF SEVERE WEATHER
STILL APPEAR POSSIBLE OTHERWISE THE STORMS IN THE NORTH SHOULD
HAVE A MARGINAL HAIL THREAT.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 334 AM CDT SAT APR 26 2014
POTENTIAL FOR SEVERE THUNDERSTORMS THROUGH SUNDAY NIGHT REMAINS THE
PRIMARY FORECAST CHALLENGE.
SEVERAL BOUTS OF SEVERE STORMS ARE POSSIBLE TODAY AND SUNDAY IN
PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA...BUT THERE IS STILL
WIDE VARIATION IN POSSIBLE SCENARIOS IN TIMING/LOCATION OF HIGHEST
PROBABILITIES. UPPER TROUGH MOVING THROUGH CENTRAL CALIFORNIA THIS
MORNING WILL MOVE THROUGH THE ROCKIES LATER TONIGHT AND EMERGE IN
THE HIGH PLAINS SUNDAY AS A CLOSED LOW...WITH SURFACE LOW POSITION
SETTING UP IN NORTHEAST QUADRANT OF UPPER LOW. NAM AND GFS ARE A
COUPLE HUNDRED MILES APART IN SURFACE LOW POSITION AT 18Z
SUNDAY...WITH ECMWF MORE IN LINE WITH NAM. HAVE FOLLOWED ECMWF MORE
CLOSELY THAN OTHER MODELS IN THIS REGARD.
SURFACE DEW POINTS ARE EXPECTED TO INCREASE INTO THE 50S LATER TODAY
AS PRESSURES FALL IN THE HIGH PLAINS UNDER INCREASING DIFFLUENT FLOW
ALOFT AHEAD OF UPPER WAVE. 50S DEW POINTS WERE SHOWING UP IN THE
TEXAS PANHANDLE THIS MORNING...IN LINE WITH 6-HOUR FORECASTS OF 00Z
MODELS...AND WILL ADVECT THROUGH KANSAS INTO SOUTHEAST NEBRASKA THIS
AFTERNOON. MEANWHILE SURFACE TEMPERATURES WILL CLIMB INTO THE LOWER
80S...YIELDING SURFACE-BASED CAPE VALUES CLOSE TO 1200 J/KG BY 00Z
IN SOUTHEAST NEBRASKA. HOWEVER FORECAST SOUNDINGS AND EXTRAPOLATION
OF WARM MID LEVEL AIR CURRENTLY IN WEST TEXAS AND NEW MEXICO SUGGEST
CAPPING WILL BE STRONG THROUGH THE AFTERNOON ACROSS ALL OF OUR AREA.
WHILE SOME MODEL SOLUTIONS POP A FEW SHOWERS/STORMS BY LATE
AFTERNOON...FEEL CAPPING WILL HOLD UNTIL LATER IN THE EVENING WHEN
LOW LEVEL JET KICKS IN. BROAD AREA OF MOST-UNSTABLE CAPE NEAR 2000
J/KG AS PER ECMWF WILL ADVECT NORTH FROM CENTRAL KANSAS INTO EASTERN
NEBRASKA BY 06Z. BULK SHEAR CLOSE TO 40KT WILL ALSO DEVELOP AS
STRONGER FLOW AND COOLER TEMPERATURES AT MID LEVELS SPREAD INTO THE
PLAINS. EXPECT CONVECTIVE INITIATION TO OCCUR IN SOUTH CENTRAL
NEBRASKA DURING THE EVENING AND SPREAD/DEVELOP EAST/NORTHEAST INTO
OUR AREA BY LATE EVENING. IF STORMS DO FIRE HERE...SURFACE WARM
FRONT WILL COME INTO PLAY...ENHANCING LOW LEVEL SHEAR/HELICITY FOR
AN ENHANCED RISK OF POTENTIAL TORNADIC STORMS...GENERALLY IN AREAS
FROM ALBION TO COLUMBUS TO LINCOLN AND SOUTHWEST.
A SECOND AREA OF INITIATION AROUND OR AFTER MIDNIGHT APPEARS LIKELY
ON NOSE OF LOW LEVEL JET RIDING UP AND OVER SURFACE FRONT...FOCUSING
ON AREAS FROM NORTHEAST NEBRASKA INTO WEST CENTRAL IOWA. THESE
STORMS WILL BE ELEVATED WITH CAPE NEAR 1500 J/KG AND SHEAR OF 40KT
TO WORK WITH...THUS LARGE HAIL WILL BE POSSIBLE.
BY SUNDAY MORNING...A MID LEVEL WAVE ROTATING NORTHEAST AROUND UPPER
LOW SPARKING CONVECTION IN KANSAS OVERNIGHT WILL SWING INTO EASTERN
NEBRASKA. EXPECT MORE STORMS TO INVADE SOUTHEAST NEBRASKA EARLY IN
THE DAY AND SPREAD NORTH THROUGH THE MORNING. INSTABILITY SHOULD BE
WANING DURING THE MORNING...BUT SHEAR INCREASING. SO DESPITE A
NORMAL LULL IN POTENTIAL SEVERE DURING THE MORNING
HOURS...COMBINATION OF SHEAR/INSTABILITY WILL STILL SUPPORT AT LEAST
SEVERE HAIL POTENTIAL IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
BY EARLY SUNDAY AFTERNOON...SURFACE DRYLINE IS FORECAST TO BE
APPROACHING OUR SOUTHWEST CWA AND ROTATING EAST/NORTHEAST TOWARD THE
MISSOURI RIVER BY LATE IN THE AFTERNOON OR EARLY EVENING. MORNING
CONVECTION WILL PLAY A ROLE IN RECOVERY OF ATMOSPHERE AHEAD OF THE
DRYLINE...WITH ECMWF SHOWING MOST-UNSTABLE CAPES DROPPING TO BELOW
1000 J/KG. BUT BULK SHEAR VALUES WILL STILL BE HIGH...AND ENHANCED
LOW LEVEL SHEAR NEAR WARM FRONT/DRYLINE TRIPLE POINT LOOKS TO SET UP
NEAR OR NORTH OF THE OMAHA METRO AREA BY 00Z. SO EXPECT EITHER A
STRENGTHENING OF ONGOING CONVECTION OR NEW CONVECTION SUNDAY
AFTERNOON IN AN ARC FROM NORTHEAST NEBRASKA INTO EAST CENTRAL
NEBRASKA AND SOUTHWEST IOWA...WITH WIND/HAIL PRIMARY SEVERE
POTENTIAL...AND A TORNADO POSSIBILITY NEAR WARM FRONT/DRYLINE
INTERSECTION NEAR/NORTH OF OMAHA AND SOUTHEAST THROUGH SOUTHWEST
IOWA.
THIS CONVECTION IS EXPECTED TO ROTATE NORTHEAST SUNDAY EVENING AND
SHOULD BE OUT OF OUR AREA SHORTLY AFTER MIDNIGHT. MEANWHILE UPPER
LOW WILL BE DRIFTING EAST SUNDAY NIGHT INTO MONDAY...BUT SHOULD
REMAIN WEST OF THE CWA. ECMWF KEEPS MOST OF OUR CWA DRY MONDAY...BUT
COLD POOL ALOFT WILL ENHANCE LAPSE RATES...SO WILL LIKELY SEE
SCATTERED SHOWERS/STORMS POPPING MONDAY AFTERNOON. SEVERE THREAT
THEN SHOULD BE MINIMAL.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 AM CDT SAT APR 26 2014
SPEED OF UPPER LOW DRIFTING THROUGH THE PLAINS WILL BE THE PRIMARY
CHALLENGE FOR NEXT WEEK...AND WILL BRING COOLER TEMPERATURES AND OFF-
AND-ON SHOWER CHANCES AT LEAST THROUGH THURSDAY. TUESDAY APPEARS TO
BE THE MOST LIKELY TIME OF WIDESPREAD SHOWERS AS UPPER LOW MOVES
INTO IOWA/MISSOURI AND SIGNIFICANT WAVE ROTATES AROUND THE LOW.
OTHERWISE WILL HAVE AT LEAST SMALL POPS EACH DAY/NIGHT THROUGH
THURSDAY. HIGH TEMPERATURES THROUGH THE WEEK WILL AVERAGE IN THE 50S
WITH A LITTLE WARMER WEATHER RETURNING FRIDAY AS UPPER LOW EXITS
EAST.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 608 AM CDT SAT APR 26 2014
VFR CONDITIONS ARE EXPECTED THROUGHOUT MUCH OF THE TAF CYCLE. THE
EXCEPTION WILL BE IN ANY TSTMS THAT DEVELOP. HAVE CONTINUED PROB30
GROUPS FOR ALL 3 SITES FROM THIS EVENING AND INTO EARLY SUNDAY
MORNING WHEN SCATTERED CONVECTION IS POSSIBLE. SOME SEVERE STORMS
ARE POSSIBLE. GUSTY SOUTHEAST WINDS OF 15 TO 20KTS WITH GUSTS TO
30KTS ARE LIKELY LATER THIS MORNING AND AFTERNOON.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...BOUSTEAD
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...KERN
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1135 PM CDT FRI APR 25 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CDT FRI APR 25 2014
THE ONGOING DROUGHT WILL CONTINUE THE FOCUS FOR CRITICAL FIRE
CONDITIONS SATURDAY AS WARM FRONT LIFTS NORTH AND EAST. DEEP
MOISTURE WILL BE LACKING WHERE STORMS THAT DO FORM WILL CREATE A
BETTER CHANCE FOR HIGH BASED THUNDERSTORMS AND A LIGHTNING DANGER
FOR FIRE IGNITION. SEE FIRE WEATHER DISCUSSION BELOW FOR MORE
DETAILS.
FORECAST TONIGHT INTO SATURDAY TRENDED TOWARD THE HIRES ECMWF. THE
MODELS ARE CREATING MORE OF A SPREAD AS THE UPPER FLOW PATTERN
SLOWS. THE 250 MB JETSTREAM WILL CONTINUE TO CARVE OUT THE LONGWAVE
TROUGH MOVING INLAND ACROSS THE WEST COAST THIS EVENING. THE MODELS
MAY STILL BE TOO FAST MOVING THE SURFACE LOW PRESSURE SYSTEM OUT ON
THE PLAINS SATURDAY EVENING. FOR THE LOCAL AREA TONIGHT QUIET WITH
SOME HIGH CLOUDS WHILE TEMPERATURES DROP INTO THE 40S.
SATURDAY THE SURFACE SYSTEM WILL ORGANIZE WITH THE DRYLINE EXTENDING
SOUTH FROM NEAR IMPERIAL SOUTH ACROSS WESTERN KANSAS. A WARM FRONT
WILL LIFT NORTH AND EAST WITH TEMPERATURES CLIMBING INTO THE MID 80S
SOUTHWEST TO MID 70S NORTH CENTRAL. THE PREVAILING SOUTHWEST FLOW
WILL DO LITTLE TO IMPROVE DEEP MOISTURE THROUGH 21Z WITH A NARROW
OPPORTUNITY FOR STORM DEVELOPMENT UNTIL EVENING. ISOLATED
THUNDERSTORMS THAT FORM SHOULD BE HIGH BASED WITH BETTER FOCUS
TOWARD THE SOUTH CENTRAL BY EVENING AS LOW LEVEL JET STRENGTHENS TO
INCREASE THE MOISTURE PROFILE FOR BETTER STORM POTENTIAL IN THE
SATURDAY NIGHT PERIOD...WITH STORM MOTION TO FOCUS OVER THE NORTH
CENTRAL WHERE A SLIGHT RISK FOR SEVERE STORMS CURRENTLY EXISTS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 344 PM CDT FRI APR 25 2014
HIGHLIGHTS OF THE LONG TERM PORTION OF THE FORECAST BEGIN WITH
SEVERE THUNDERSTORM CHANCES SATURDAY NIGHT AND SUNDAY...THEN TURN TO
POTENTIAL FOR SNOW AND COLD AND WINDY CONDITIONS AS A LARGE STORM
SYSTEM SLOWLY MAKES ITS WAY ACROSS THE CENTRAL PART OF THE COUNTRY.
THE UPPER LEVEL TROUGH CURRENTLY OFF THE WEST COAST WILL MAKE ITS
WAY ACROSS THE GREAT BASIN THROUGH THE DAY SATURDAY THEN WILL LIFT
INTO THE CENTRAL PLAINS SATURDAY NIGHT AND SUNDAY.
AS A SURFACE LOW DEVELOPS AHEAD OF THE UPPER LEVEL SYSTEM...THE
WARM FRONT WILL LIFT NORTH ACROSS NEBRASKA SATURDAY EVENING AND
BY 06Z SHOULD BE ROUGHLY FROM EXTREME NORTHEAST COLORADO INTO
NORTHEAST NEBRASKA WITH THE SURFACE LOW SITUATED OVER THE
SOUTHEAST NEBRASKA PANHANDLE. THE MODELS HAVE BEEN CONSISTENT WITH
A DRYLINE EXTENDING SLIGHTLY EAST OF THE LOW TO NEAR HIGHWAY 83 BY
KLBF AND THEN GOING SOUTH THROUGH WESTERN KANSAS. THIS IS A FAIRLY
TIGHT DRYLINE WITH DEWPOINTS VARYING FROM THE LOW 20S TO THE MID
50S IN A SHORT AREA. THERE WILL BE A STRONG LOW LEVEL JET SATURDAY
EVENING...HOWEVER SOUNDINGS ARE SHOWING AREAS IN THE WARM SECTOR
STAYING CAPPED. THERE IS DECENT SHEAR...SO IF ENOUGH MOISTURE IS
BROUGHT NORTH TO GET STORMS TO DEVELOP ALONG THE WARM FRONT THEY
COULD BECOME ORGANIZED. SO THERE IS POTENTIAL FOR STORMS...YET
HIGHER CHANCES WILL LIE INTO EASTERN NEBRASKA WHERE MORE MOISTURE
WILL BE IN PLACE. WITH THE CAP IN PLACE AND LACK OF MOISTURE IN
THE LOWER LEVELS...BETTER CHANCES MAY BE FOR ELEVATED CONVECTION
SO THREATS FROM STORMS WOULD BE MAINLY LARGE HAIL AND STRONG
WINDS. THAT BEING SAID...THE TRACK OF THE UPPER LEVEL SYSTEM WOULD
SUGGEST MUCH OF NEBRASKA MAY GET DRY SLOTTED SATURDAY NIGHT INTO
SUNDAY. THE TREND IN THE MOST RECENT MODEL RUNS HAS BEEN IN THIS
DIRECTION SO PRECIPITATION CHANCES HAVE BEEN REDUCED ACCORDINGLY.
BY SUNDAY MORNING AT 12Z...THE UPPER LOW IS CENTERED OVER EASTERN
COLORADO AND BEYOND THAT POINT DIFFERENCES IN THE NORTH TO SOUTH
ASPECT OF THE SYSTEM START TO DIVERGE. BY 28.00Z THE DIFFERENCE IN
THE 500MB LOW RANGES FROM ROUGHLY OVER SHERIDAN AND CHERRY
COUNTIES INTO SOUTH DAKOTA IN THE GFS TO THE WESTERN NEBRASKA
SANDHILLS IN THE ECMWF AND GEM...TO THE COLBY/HILL CITY AREAS IN
KANSAS IN THE NAM. THE DIFFERENCE IN THESE SOLUTIONS BRINGS A
CONSIDERABLE LACK IN CONFIDENCE ON WHAT THE OUTCOME WILL BE FOR
SENSIBLE WEATHER SUNDAY AND BEYOND. THIS FORECAST PACKAGE TRENDED
BETWEEN THE MORE SOUTHERN SOLUTIONS WITH IT COMING FROM BLENDS OF
THESE MODELS.
WITH THE GFS NOT BEING CONSIDERED...DRY AIR DOES CONTINUE TO MOVE
INTO THE REGION AS THE UPPER LOW MOVES ACROSS THE CENTRAL PLAINS.
HOWEVER THE ECMWF/GEM RUNS WOULD KEEP A LOT OF THE AREA DRY ALL DAY
WHILE PRECIPITATION WOULD BE EXPECTED OVER MUCH OF NORTHERN
NEBRASKA. WHEREVER THE SURFACE LOW TRACKS...THERE WILL BE A TIGHT
DRYLINE ORIENTED EAST OF THE LOW...THEN SOUTHWARD THROUGH EASTERN
KANSAS. THE MODELS DO SHOW MOISTURE BING TRANSPORTED BACK INTO
NORTH CENTRAL NEBRASKA AHEAD OF THE DRYLINE AND SOUNDINGS SHOW THE
CAP ERODING BY MID AFTERNOON SO CONVECTION IS POSSIBLE. THE HIGHER
CHANCES CURRENTLY ARE OVER NORTH CENTRAL NEBRASKA...AND WHILE THE
DEEP LAYER BULK SHEAR ISN/T GREAT...THERE IS ABOUT 30KTS IN THESE
AREAS SO WHILE WIDESPREAD SEVERE STORMS MAY NOT OCCUR...ITS NOT
OUT OF THE QUESTION TO MAYBE GET A FEW STRONG TO SEVERE STORMS.
ANOTHER CONCERN FOR SUNDAY IS IF THE NAM IS ON THE RIGHT
TRACK...THERE COULD BE A VERY NARROW BAND OF WEAK CAPE THAT IS
PULLED AROUND THE LOW LEVEL CIRCULATION. THIS WOULD BE CO-LOCATED
WITH STEEP LOW LEVEL LAPSE RATES /AS COLD AIR WITH THE UPPER LEVEL
LOW MOVES INTO THE AREA/...AS WELL AS A SURFACE INVERTED TROUGH FROM
SOUTHWEST INTO NORTH CENTRAL NEBRASKA. IF THIS SITUATION WOULD PAN
OUT...ANY CONVECTION ALONG THIS SURFACE BOUNDARY COULD HAVE THE
POTENTIAL TO PRODUCE NON- SUPERCELL TORNADOS.
SUNDAY NIGHT...COLD AIR WILL ADVECT INTO THE FORECAST AREA ON THE
BACKSIDE OF THE SYSTEM. HOW COLD THE AIR WILL BE IS STILL IN
QUESTION DEPENDENT ON THE TRACK OF THE UPPER LOW. THE ECMWF/GEM/NAM
WOULD BRING ENOUGH COLD AIR INTO THE PANHANDLE AND WESTERN
SANDHILLS TO SUGGEST PRECIPITATION WILL CHANGE OVER TO SNOW
OVERNIGHT. AS THE NORTHERN SOLUTION HAS BEEN DISCOUNTED AT THIS
TIME...DID INSERT A RAIN/SNOW MIX INTO THE FORECAST FOR SUNDAY
NIGHT INTO MONDAY MORNING. AT THIS TIME AM NOT GOING TO INTRODUCE
ANY AMOUNTS DUE TO HIGH UNCERTAINTY IN ACCUMULATION...BUT WOULD
NOT BE SURPRISED TO SEE A FEW FLAKES AT LEAST. THAT BEING SAID...IF THE
NAM WOULD BE ON THE RIGHT TRACK...THERE WOULD BE POTENTIAL FOR
ACCUMULATING SNOW...ESPECIALLY FROM OGALLALA TO THEDFORD TO
AINSWORTH AND AREAS TO THE WEST.
MOVING THROUGH THE WEEK...A SHORT LIVED REX BLOCKING PATTERN SETS
UP WITH AN UPPER HIGH OVER HUDSON BAY AND CENTRAL CANADA WITH THE
WEEKEND SYSTEM STAYING CENTERED OVER THE CENTRAL PLAINS. THE UPPER
LEVEL SYSTEM IS LIKELY TO SIT AND SPIN OVER THE REGION THROUGH
MUCH OF THE NEXT WEEK. WHILE THIS IS ONGOING...TEMPERATURES WILL
BE COOL /HIGHS IN THE 40S AND 50S...LOWS IN THE 30S./ WITH CHANCES FOR
LIGHT PRECIPITATION DAILY. IT ALSO DOES LOOK COLD ENOUGH MONDAY
AND TUESDAY NIGHTS FOR ANOTHER SHOT OF SNOW FOR PORTIONS OF THE
AREA. AGAIN...CONFIDENCE ON ACCUMULATING SNOW IS LOW SO AT THIS
TIME JUST HAVE A CHANCE FOR RAIN/SNOW IN THIS TIME PERIOD. THE
MODELS ARE STARTING TO AT LEAST SLOWLY MOVE THE SYSTEM EAST BY THE
END OF THE WORK WEEK. THIS WILL ALLOW A VERY GRADUAL WARM UP INTO
NEXT WEEKEND WITH CHANCES FOR PRECIPITATION WANING.
THE LAST CONCERN IS WINDS. AS THE SYSTEM MOVES ACROSS THE
PLAINS...THERE WILL BE POTENTIAL FOR STRONG WINDS DAILY...SUNDAY
NIGHT THROUGH THURSDAY. WITH THE SLOW MOVEMENT...AREAS ESPECIALLY
WEST OF HIGHWAY 83 WILL BE ON THE BACK SIDE OF THE SYSTEM WHICH
WILL LEAD TO A TIGHT PRESSURE GRADIENT...COLD AIR
ADVECTION...SUBSIDENCE AT TIMES...AND WITH STRONG WINDS
ALOFT...ANY MIXING COULD BRING VERY STRONG WINDS TO THE AREA. WILL
NEED TO WATCH THE NEED FOR HEADLINES FOR WINDS THROUGH MUCH OF THE
WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 1135 PM CDT FRI APR 25 2014
VFR IS EXPECTED ALL AREAS TONIGHT THROUGH 21Z SATURDAY.
THEREAFTER...ISOLATED STRONG THUNDERSTORMS MAY
DEVELOP...GENERALLY ALONG AND NORTH OF NEBRASKA HIGHWAY 2. STORM
MOTION WILL BE NORTHEAST AT AROUND 25 MPH. STORM DEVELOPMENT IS
EXPECTED TO BECOME SCATTERED ACROSS NORTHWEST NEB SATURDAY EVENING
WHILE REMAINING ISOLATED ELSEWHERE.
VFR CIGS PREVAIL THROUGH AT LEAST 03Z SATURDAY EVENING. THERE IS A
CHANCE FOR MVFR CIGS IN THE NORTHEAST AS MOISTURE POOLS ALONG A
STATIONARY FRONT. THIS WOULD BECOME MORE LIKELY FROM 06Z SATURDAY
NIGHT ONWARD.
&&
.FIRE WEATHER...
ISSUED AT 1135 PM CDT FRI APR 25 2014
THE RAP AND NAM MODELS ARE GIVING A GOOD SIGNAL FOR RED FLAG
CONDITIONS ACROSS THE FRENCHMAN BASIN SATURDAY. A SURGE OF DRY AIR
WILL BE MOVING NORTH THRU KS DURING THE AFTN. A RED FLAG WARNING
IS IN PLACE FOR FRENCHMAN BASIN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM TO 10 PM CDT SATURDAY FOR NEZ210.
&&
$$
SHORT TERM...KECK
LONG TERM...BROOKS
AVIATION...CDC
FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS ELKO NV
1124 AM PDT SAT APR 26 2014
.SYNOPSIS...LINGERING SHOWERS WILL CONTINUE ACROSS EASTERN NEVADA
TODAY BEHIND A STRONG LATE WINTER STORM. DRY WEATHER RETURNS
BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS
NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO
RETURN NEXT WEEK.
&&
.UPDATE...LET WINTER WEATHER PRODUCTS EXPIRE AT 11 AM AS STORM
SYSTEM EXITING THE AREA WITH ONLY ISOLATED TO SCATTERED SNOW
SHOWERS OCCURRING AT THIS TIME ACROSS ERN NV WITH LITTLE OR NO
ADDITIONAL ACCUMULATION EXPECTED. ALSO REDUCED SHOWER COVERAGE
INTO THE ISOLATED TO SCATTERED CATEGORY.
&&
.PREV DISCUSSION... /ISSUED AT 815 AM /
SYNOPSIS...A STRONG LATE WINTER STORM WILL BRING WIDESPREAD RAIN
AND SNOW TO NEVADA THROUGH SATURDAY MORNING. DRY WEATHER RETURNS
BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS
NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO
RETURN NEXT WEEK.
SHORT TERM...TODAY THROUGH MONDAY.
STRONG BUT PROGRESSIVE LATE WINTER/SPRING STORM SHAPING UP PRETTY
MUCH AS PLANNED THIS MORNING. NAM/GFS/HRRR GUIDANCE IN EXCELLENT
AGREEMENT THAT THE PEAK OF THIS WINTER WEATHER EVENT WILL OCCUR
EARLY THIS MORNING, A FEW HOURS EITHER SIDE OF SUNRISE, ALONG A
TONOPAH-EUREKA-NW WHITE PINE COUNTY-SE ELKO COUNTY LINE. HEAVY WET
SNOW WILL FALL IN THIS CORRIDOR FOR SEVERAL HOURS FROM NOW THROUGH
EARLY SATURDAY MORNING, WITH SEVERAL INCHES EXPECTED ESPECIALLY ON
ELEVATED/VEGETATED SURFACES. IMPACTS WILL BE VERY ELEVATION
DEPENDENT, TYPICAL OF LATE APRIL SNOWSTORMS, BUT PASSES AND
SUMMITS ABOVE 5500 FEET WILL BE SLUSH/SNOW COVERED AND TREACHEROUS
THIS MORNING. WILL ALLOW WINTER STORM WARNINGS TO CONTINUE AS
PLANNED. A WILDCARD IN REGARD TO SNOWFALL AMOUNTS IS CONVECTION.
LIGHTNING DETECTION AND IR SATELLITE CONTINUES TO INDICATE
THUNDERSTORMS ROTATING NORTHWARD INTO WHITE PINE COUNTY. SNOWFALL
RATES WILL BE ERRATIC AND BRIEFLY INTENSE IN THE WINTER STORM
WARNING AREA THIS MORNING. SINCE THE SNOW IS OCCURRING ON A
SATURDAY MORNING WITH NO SCHOOL AND LIMITED COMMUTING, IMPACTS
WILL BE LIMITED, BUT NONETHELESS THESE INTENSE SNOWFALL RATES WILL
LIKELY OVERCOME ANY WARM ROADWAYS AND MAKE TRAVEL DANGEROUS AT
TIMES UNTIL THE MID-MORNING HOURS.
REGARDING ELKO COUNTY...00Z NAM AND HRRR BOTH DEPICT A VERY TIGHT
PRECIPITATION GRADIENT, WITH NW ELKO COUNTY GETTING LITTLE TO NO
SNOW, AND HEAVY SNOW FALLING ON THE RUBY MOUNTAINS AND SE ELKO
COUNTY. SNOWFALL FROM 00Z NAM SHOWS THIS TIGHT GRADIENT AND
APPEARS VERY REASONABLE ON THE NW EDGE OF THE DEFORMATION BAND.
EXPECTING ABOUT 1/2 INCH AT ELKO PROPER, 2-4 INCHES IN SPRING
CREEK, AND NEAR 6 INCHES ADJACENT TO THE RUBY MOUNTAINS, SUCH AS
JIGGS, LEE, AND LAMOILLE. WILL ALSO KEEP THE WINTER WEATHER
ADVISORY GOING FOR ELEVATIONS ABOVE 5500 FEET FOR ELKO COUNTY
THROUGH 11 AM.
PRIMARY SURFACE LOW SW OF ELY EARLY THIS MORNING WILL RAPIDLY PULL
EASTWARD THROUGH UTAH THIS MORNING, AND BE IN WYOMING BY MIDDAY.
IN OTHER WORDS, SYSTEM IS QUITE PROGRESSIVE AND SNOW SHOWERS WILL
TAPER OFF QUICKLY AFTER NOON. ALSO, IMPACTS TO ROADWAYS WILL END
RAPIDLY AFTER 11 AM WITH THE LATE APRIL SUNSHINE, SO ALL WINTER
HEADLINES WILL EXPIRE AT THAT TIME. NW FLOW AND COLD AIR ALOFT IS
QUITE AGITATED THIS AFTERNOON, SO KEPT PLENTY OF SNOW/SNOW PELLET
SHOWERS MENTIONED THIS AFTERNOON, BUT AMOUNTS WILL BE LIGHT.
NW WINDS WILL BE STRONG AND GUSTY TODAY AS THE STORM SYSTEM
DEPARTS. NW WINDS WILL AVERAGE 20-30 MPH WITH HIGHER GUSTS.
BELIEVE WINDS WILL REMAIN BELOW ADVISORY CRITERIA, WITH THE
EXCEPTION OF NW NYE COUNTY/TONOPAH. WIND GUSTS OF 50-55 MPH APPEAR
LIKELY HERE TODAY, AND ISSUED A WIND ADVISORY FOR NW NYE COUNTY
FROM 5 AM THROUGH 5 PM.
A BRIEF BREAK OF DRY WEATHER TONIGHT, WITH LOWS NEAR FREEZING.
SUNDAY...FINAL SHORTWAVE SKIRTS THROUGH NORTHERN NEVADA IN THE
CHILLY NW FLOW. THIS SHOULD BE A PROLIFIC SNOW AND GRAUPEL SHOWER
PRODUCER SUNDAY AFTERNOON MAINLY ACROSS ELKO COUNTY. INCREASED
SHOWER COVERAGE IN THE GRIDS, BUT APPEARS TO BE A HIGH POP/LOW QPF
SITUATION IN WHICH AMOUNTS WILL BE INSIGNIFICANT. STILL,
VISIBILITY WILL BE SHARPLY REDUCED BY THESE PASSING CONVECTIVE
SNOW SHOWERS. 00Z GFS DEPICTS LIFTED INDEX LESS THAN ZERO ACROSS
ELKO COUNTY SUNDAY AFTERNOON, SO MENTIONED ISOLATED THUNDER AS WELL.
SUNDAY WILL BE A DECIDEDLY UNPLEASANT "SPRING" DAY IN NEVADA WITH
TEMPERATURES STUCK IN THE 40S MOST OF THE DAY, AND STRONG GUSTY
WEST WINDS OF 20-30 MPH MAKING IT FEEL EVEN COLDER THAN THAT.
SOME DECREASE IN CLOUDS SUNDAY NIGHT, ALLOWING FOR COLDER LOWS
MONDAY MORNING IN THE MID TO UPPER 20S.
MONDAY...DRY WEATHER RETURNS UNDER DRY NW FLOW. STILL QUITE
CHILLY, WITH TEMPERATURES RUNNING ABOUT 10 DEGREES BELOW LATE
APRIL NORMALS.
TURNER
LONG TERM...MONDAY NIGHT THROUGH FRIDAY. HIGH PRESSURE WILL BRING
DRY CONDITIONS TO THE GREAT BASIN WITH A WARMING TREND. THERE IS
GOOD MODEL AGREEMENT INDICATING THAT A PACIFIC RIDGE WILL STRONGLY
AMPLIFY NEXT WEEK AND PROGRESS EAST AT AN EXTREMELY SLOW RATE. THE
RIDGE AXIS WILL ONLY MOVE FROM OFF THE CALIFORNIA COAST MONDAY NIGHT
TO REPOSITION THROUGH NEVADA FRIDAY...AS THE DE-AMPLIFICATION
PROCESS BEGINS. LOW TEMPERATURES WILL GENERALLY FALL INTO THE 20S
MONDAY NIGHT...AND THE 30S THEREAFTER. HIGH TEMPERATURES WILL
GENERALLY BE IN THE 50S TUESDAY...RISE INTO THE 60S WEDNESDAY...THEN
INTO THE 70S IN MANY PLACES THURSDAY AND FRIDAY.
AVIATION...A MOISTURE-LADEN STORM SYSTEM WILL CONTINUE TO BRING
WIDESPREAD RAIN AND SNOW SHOWERS THROUGH SATURDAY MORNING PRODUCING
AREAS OF MVFR CONDITIONS. SHOWERS WILL TAPER OFF THIS EVENING AND
THERE MAY BE A BRIEF BREAK AFTER THIS STORM EXITS. HOWEVER ANOTHER
WAVE OF LOW PRESSURE WILL BRING MORE SHOWER ACTIVITY THROUGH SUNDAY
MORNING.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR NORTHWESTERN NYE
COUNTY.
&&
$$
91/99/92
AREA FORECAST DISCUSSION
NWS ELKO NV
815 AM PDT SAT APR 26 2014
.SYNOPSIS...A STRONG LATE WINTER STORM WILL BRING WIDESPREAD RAIN
AND SNOW TO NEVADA THROUGH SATURDAY MORNING. DRY WEATHER RETURNS
BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS
NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO
RETURN NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH MONDAY.
STRONG BUT PROGRESSIVE LATE WINTER/SPRING STORM SHAPING UP PRETTY
MUCH AS PLANNED THIS MORNING. NAM/GFS/HRRR GUIDANCE IN EXCELLENT
AGREEMENT THAT THE PEAK OF THIS WINTER WEATHER EVENT WILL OCCUR
EARLY THIS MORNING, A FEW HOURS EITHER SIDE OF SUNRISE, ALONG A
TONOPAH-EUREKA-NW WHITE PINE COUNTY-SE ELKO COUNTY LINE. HEAVY WET
SNOW WILL FALL IN THIS CORRIDOR FOR SEVERAL HOURS FROM NOW THROUGH
EARLY SATURDAY MORNING, WITH SEVERAL INCHES EXPECTED ESPECIALLY ON
ELEVATED/VEGETATED SURFACES. IMPACTS WILL BE VERY ELEVATION
DEPENDENT, TYPICAL OF LATE APRIL SNOWSTORMS, BUT PASSES AND
SUMMITS ABOVE 5500 FEET WILL BE SLUSH/SNOW COVERED AND TREACHEROUS
THIS MORNING. WILL ALLOW WINTER STORM WARNINGS TO CONTINUE AS
PLANNED. A WILDCARD IN REGARD TO SNOWFALL AMOUNTS IS CONVECTION.
LIGHTNING DETECTION AND IR SATELLITE CONTINUES TO INDICATE
THUNDERSTORMS ROTATING NORTHWARD INTO WHITE PINE COUNTY. SNOWFALL
RATES WILL BE ERRATIC AND BRIEFLY INTENSE IN THE WINTER STORM
WARNING AREA THIS MORNING. SINCE THE SNOW IS OCCURRING ON A
SATURDAY MORNING WITH NO SCHOOL AND LIMITED COMMUTING, IMPACTS
WILL BE LIMITED, BUT NONETHELESS THESE INTENSE SNOWFALL RATES WILL
LIKELY OVERCOME ANY WARM ROADWAYS AND MAKE TRAVEL DANGEROUS AT
TIMES UNTIL THE MID-MORNING HOURS.
REGARDING ELKO COUNTY...00Z NAM AND HRRR BOTH DEPICT A VERY TIGHT
PRECIPITATION GRADIENT, WITH NW ELKO COUNTY GETTING LITTLE TO NO
SNOW, AND HEAVY SNOW FALLING ON THE RUBY MOUNTAINS AND SE ELKO
COUNTY. SNOWFALL FROM 00Z NAM SHOWS THIS TIGHT GRADIENT AND
APPEARS VERY REASONABLE ON THE NW EDGE OF THE DEFORMATION BAND.
EXPECTING ABOUT 1/2 INCH AT ELKO PROPER, 2-4 INCHES IN SPRING
CREEK, AND NEAR 6 INCHES ADJACENT TO THE RUBY MOUNTAINS, SUCH AS
JIGGS, LEE, AND LAMOILLE. WILL ALSO KEEP THE WINTER WEATHER
ADVISORY GOING FOR ELEVATIONS ABOVE 5500 FEET FOR ELKO COUNTY
THROUGH 11 AM.
PRIMARY SURFACE LOW SW OF ELY EARLY THIS MORNING WILL RAPIDLY PULL
EASTWARD THROUGH UTAH THIS MORNING, AND BE IN WYOMING BY MIDDAY.
IN OTHER WORDS, SYSTEM IS QUITE PROGRESSIVE AND SNOW SHOWERS WILL
TAPER OFF QUICKLY AFTER NOON. ALSO, IMPACTS TO ROADWAYS WILL END
RAPIDLY AFTER 11 AM WITH THE LATE APRIL SUNSHINE, SO ALL WINTER
HEADLINES WILL EXPIRE AT THAT TIME. NW FLOW AND COLD AIR ALOFT IS
QUITE AGITATED THIS AFTERNOON, SO KEPT PLENTY OF SNOW/SNOW PELLET
SHOWERS MENTIONED THIS AFTERNOON, BUT AMOUNTS WILL BE LIGHT.
NW WINDS WILL BE STRONG AND GUSTY TODAY AS THE STORM SYSTEM
DEPARTS. NW WINDS WILL AVERAGE 20-30 MPH WITH HIGHER GUSTS.
BELIEVE WINDS WILL REMAIN BELOW ADVISORY CRITERIA, WITH THE
EXCEPTION OF NW NYE COUNTY/TONOPAH. WIND GUSTS OF 50-55 MPH APPEAR
LIKELY HERE TODAY, AND ISSUED A WIND ADVISORY FOR NW NYE COUNTY
FROM 5 AM THROUGH 5 PM.
A BRIEF BREAK OF DRY WEATHER TONIGHT, WITH LOWS NEAR FREEZING.
SUNDAY...FINAL SHORTWAVE SKIRTS THROUGH NORTHERN NEVADA IN THE
CHILLY NW FLOW. THIS SHOULD BE A PROLIFIC SNOW AND GRAUPEL SHOWER
PRODUCER SUNDAY AFTERNOON MAINLY ACROSS ELKO COUNTY. INCREASED
SHOWER COVERAGE IN THE GRIDS, BUT APPEARS TO BE A HIGH POP/LOW QPF
SITUATION IN WHICH AMOUNTS WILL BE INSIGNIFICANT. STILL,
VISIBILITY WILL BE SHARPLY REDUCED BY THESE PASSING CONVECTIVE
SNOW SHOWERS. 00Z GFS DEPICTS LIFTED INDEX LESS THAN ZERO ACROSS
ELKO COUNTY SUNDAY AFTERNOON, SO MENTIONED ISOLATED THUNDER AS WELL.
SUNDAY WILL BE A DECIDEDLY UNPLEASANT "SPRING" DAY IN NEVADA WITH
TEMPERATURES STUCK IN THE 40S MOST OF THE DAY, AND STRONG GUSTY
WEST WINDS OF 20-30 MPH MAKING IT FEEL EVEN COLDER THAN THAT.
SOME DECREASE IN CLOUDS SUNDAY NIGHT, ALLOWING FOR COLDER LOWS
MONDAY MORNING IN THE MID TO UPPER 20S.
MONDAY...DRY WEATHER RETURNS UNDER DRY NW FLOW. STILL QUITE
CHILLY, WITH TEMPERATURES RUNNING ABOUT 10 DEGREES BELOW LATE
APRIL NORMALS.
TURNER
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. HIGH PRESSURE WILL BRING
DRY CONDITIONS TO THE GREAT BASIN WITH A WARMING TREND. THERE IS
GOOD MODEL AGREEMENT INDICATING THAT A PACIFIC RIDGE WILL STRONGLY
AMPLIFY NEXT WEEK AND PROGRESS EAST AT AN EXTREMELY SLOW RATE. THE
RIDGE AXIS WILL ONLY MOVE FROM OFF THE CALIFORNIA COAST MONDAY NIGHT
TO REPOSITION THROUGH NEVADA FRIDAY...AS THE DE-AMPLIFICATION
PROCESS BEGINS. LOW TEMPERATURES WILL GENERALLY FALL INTO THE 20S
MONDAY NIGHT...AND THE 30S THEREAFTER. HIGH TEMPERATURES WILL
GENERALLY BE IN THE 50S TUESDAY...RISE INTO THE 60S WEDNESDAY...THEN
INTO THE 70S IN MANY PLACES THURSDAY AND FRIDAY.
&&
.AVIATION...A MOISTURE-LADEN STORM SYSTEM WILL CONTINUE TO BRING
WIDESPREAD RAIN AND SNOW SHOWERS THROUGH SATURDAY MORNING PRODUCING
AREAS OF MVFR CONDITIONS. SHOWERS WILL TAPER OFF THIS EVENING AND
THERE MAY BE A BRIEF BREAK AFTER THIS STORM EXITS. HOWEVER ANOTHER
WAVE OF LOW PRESSURE WILL BRING MORE SHOWER ACTIVITY THROUGH SUNDAY
MORNING.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 11 AM PDT THIS MORNING FOR RUBY
MOUNTAINS/EAST HUMBOLDT RANGE...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY.
WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING FOR SOUTH
CENTRAL ELKO COUNTY.
WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING ABOVE 5500
FEET FOR SOUTHWESTERN ELKO COUNTY.
WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM PDT THIS
AFTERNOON FOR NORTHWESTERN NYE COUNTY.
&&
$$
99/92/92
AREA FORECAST DISCUSSION
NWS ELKO NV
111 AM PDT SAT APR 26 2014
.SYNOPSIS...A STRONG LATE WINTER STORM WILL BRING WIDESPREAD RAIN
AND SNOW TO NEVADA THROUGH SATURDAY MORNING. DRY WEATHER RETURNS
BRIEFLY SATURDAY NIGHT...FOLLOWED BY MORE SNOW SHOWERS ACROSS
NORTHERN NEVADA ON SUNDAY. DRIER AND WARMER WEATHER IS EXPECTED TO
RETURN NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH MONDAY.
STRONG BUT PROGRESSIVE LATE WINTER/SPRING STORM SHAPING UP PRETTY
MUCH AS PLANNED THIS MORNING. NAM/GFS/HRRR GUIDANCE IN EXCELLENT
AGREEMENT THAT THE PEAK OF THIS WINTER WEATHER EVENT WILL OCCUR
EARLY THIS MORNING, A FEW HOURS EITHER SIDE OF SUNRISE, ALONG A
TONOPAH-EUREKA-NW WHITE PINE COUNTY-SE ELKO COUNTY LINE. HEAVY WET
SNOW WILL FALL IN THIS CORRIDOR FOR SEVERAL HOURS FROM NOW THROUGH
EARLY SATURDAY MORNING, WITH SEVERAL INCHES EXPECTED ESPECIALLY ON
ELEVATED/VEGETATED SURFACES. IMPACTS WILL BE VERY ELEVATION
DEPENDENT, TYPICAL OF LATE APRIL SNOWSTORMS, BUT PASSES AND
SUMMITS ABOVE 5500 FEET WILL BE SLUSH/SNOW COVERED AND TREACHEROUS
THIS MORNING. WILL ALLOW WINTER STORM WARNINGS TO CONTINUE AS
PLANNED. A WILDCARD IN REGARD TO SNOWFALL AMOUNTS IS CONVECTION.
LIGHTNING DETECTION AND IR SATELLITE CONTINUES TO INDICATE
THUNDERSTORMS ROTATING NORTHWARD INTO WHITE PINE COUNTY. SNOWFALL
RATES WILL BE ERRATIC AND BRIEFLY INTENSE IN THE WINTER STORM
WARNING AREA THIS MORNING. SINCE THE SNOW IS OCCURRING ON A
SATURDAY MORNING WITH NO SCHOOL AND LIMITED COMMUTING, IMPACTS
WILL BE LIMITED, BUT NONETHELESS THESE INTENSE SNOWFALL RATES WILL
LIKELY OVERCOME ANY WARM ROADWAYS AND MAKE TRAVEL DANGEROUS AT
TIMES UNTIL THE MID-MORNING HOURS.
REGARDING ELKO COUNTY...00Z NAM AND HRRR BOTH DEPICT A VERY TIGHT
PRECIPITATION GRADIENT, WITH NW ELKO COUNTY GETTING LITTLE TO NO
SNOW, AND HEAVY SNOW FALLING ON THE RUBY MOUNTAINS AND SE ELKO
COUNTY. SNOWFALL FROM 00Z NAM SHOWS THIS TIGHT GRADIENT AND
APPEARS VERY REASONABLE ON THE NW EDGE OF THE DEFORMATION BAND.
EXPECTING ABOUT 1/2 INCH AT ELKO PROPER, 2-4 INCHES IN SPRING
CREEK, AND NEAR 6 INCHES ADJACENT TO THE RUBY MOUNTAINS, SUCH AS
JIGGS, LEE, AND LAMOILLE. WILL ALSO KEEP THE WINTER WEATHER
ADVISORY GOING FOR ELEVATIONS ABOVE 5500 FEET FOR ELKO COUNTY
THROUGH 11 AM.
PRIMARY SURFACE LOW SW OF ELY EARLY THIS MORNING WILL RAPIDLY PULL
EASTWARD THROUGH UTAH THIS MORNING, AND BE IN WYOMING BY MIDDAY.
IN OTHER WORDS, SYSTEM IS QUITE PROGRESSIVE AND SNOW SHOWERS WILL
TAPER OFF QUICKLY AFTER NOON. ALSO, IMPACTS TO ROADWAYS WILL END
RAPIDLY AFTER 11 AM WITH THE LATE APRIL SUNSHINE, SO ALL WINTER
HEADLINES WILL EXPIRE AT THAT TIME. NW FLOW AND COLD AIR ALOFT IS
QUITE AGITATED THIS AFTERNOON, SO KEPT PLENTY OF SNOW/SNOW PELLET
SHOWERS MENTIONED THIS AFTERNOON, BUT AMOUNTS WILL BE LIGHT.
NW WINDS WILL BE STRONG AND GUSTY TODAY AS THE STORM SYSTEM
DEPARTS. NW WINDS WILL AVERAGE 20-30 MPH WITH HIGHER GUSTS.
BELIEVE WINDS WILL REMAIN BELOW ADVISORY CRITERIA, WITH THE
EXCEPTION OF NW NYE COUNTY/TONOPAH. WIND GUSTS OF 50-55 MPH APPEAR
LIKELY HERE TODAY, AND ISSUED A WIND ADVISORY FOR NW NYE COUNTY
FROM 5 AM THROUGH 5 PM.
A BRIEF BREAK OF DRY WEATHER TONIGHT, WITH LOWS NEAR FREEZING.
SUNDAY...FINAL SHORTWAVE SKIRTS THROUGH NORTHERN NEVADA IN THE
CHILLY NW FLOW. THIS SHOULD BE A PROLIFIC SNOW AND GRAUPEL SHOWER
PRODUCER SUNDAY AFTERNOON MAINLY ACROSS ELKO COUNTY. INCREASED
SHOWER COVERAGE IN THE GRIDS, BUT APPEARS TO BE A HIGH POP/LOW QPF
SITUATION IN WHICH AMOUNTS WILL BE INSIGNIFICANT. STILL,
VISIBILITY WILL BE SHARPLY REDUCED BY THESE PASSING CONVECTIVE
SNOW SHOWERS. 00Z GFS DEPICTS LIFTED INDEX LESS THAN ZERO ACROSS
ELKO COUNTY SUNDAY AFTERNOON, SO MENTIONED ISOLATED THUNDER AS WELL.
SUNDAY WILL BE A DECIDEDLY UNPLEASANT "SPRING" DAY IN NEVADA WITH
TEMPERATURES STUCK IN THE 40S MOST OF THE DAY, AND STRONG GUSTY
WEST WINDS OF 20-30 MPH MAKING IT FEEL EVEN COLDER THAN THAT.
SOME DECREASE IN CLOUDS SUNDAY NIGHT, ALLOWING FOR COLDER LOWS
MONDAY MORNING IN THE MID TO UPPER 20S.
MONDAY...DRY WEATHER RETURNS UNDER DRY NW FLOW. STILL QUITE
CHILLY, WITH TEMPERATURES RUNNING ABOUT 10 DEGREES BELOW LATE
APRIL NORMALS.
TURNER
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY. THE PERIOD BEGINS WITH
STRONG UPPER RIDGE BUILDING INTO THE REGION FOR DRY AND WARMER WEATHER.
THE RIDGE WILL REACH ITS PEAK STRENGTH WEDNESDAY AND THURSDAY THEN
BEGIN TO FLATTEN ON FRIDAY. TEMPS WILL BEGIN THE PERIOD SLIGHTLY
BELOW NORMAL WITH HIGHS IN THE MID 50S TO THE MID 60S BUT WILL END
THE PERIOD MUCH ABOVE NORMAL WITH HIGHS GENERALLY IN THE UPPER 60S
TO THE MID 70S.
&&
.AVIATION...STORM SYSTEM WILL BRING WIDESPREAD SHOWERS THROUGH
SATURDAY MORNING WITH AREAS OF MVFR CONDITIONS. RAIN IS EXPECTED TO
TURN OVER TO SNOW AT KTPH AROUND 04Z, AT KELY AROUND 10Z, AND KEKO
AROUND 12Z BRINGING IFR CONDITIONS.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 11 AM PDT THIS MORNING FOR RUBY
MOUNTAINS/EAST HUMBOLDT RANGE...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY.
WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING FOR SOUTH
CENTRAL ELKO COUNTY.
WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING ABOVE 5500
FEET FOR SOUTHWESTERN ELKO COUNTY.
WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM PDT THIS
AFTERNOON FOR NORTHWESTERN NYE COUNTY.
&&
$$
99/92/92
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
324 AM EDT SAT APR 26 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK EAST ACROSS THE AREA TONIGHT
BRINGING SOME SHOWERS. A FEW SHOWERS WILL LINGER SATURDAY AND
SATURDAY NIGHT AS UPPER LEVEL LOW PRESSURE MOVES ACROSS THE AREA.
HIGH PRESSURE OVER EASTERN CANADA WILL BRING A RETURN TO MAINLY
DRY WEATHER SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
810 PM UPDATE...
NUMEROUS LOPRES CNTRS ON SFC ANALYSIS THIS EVNG, ONE OVR UP OF
MICHIGAN, ANOTHER OVR WRN NY AND YET ANOTHER DOWN OVR THE PIEDMONT
OF NC. TWO AREAS OF SHOWERS AFFECTING CWA AT THIS TIME, WITH FIRST
BATCH HVG MVD UP FM PA IN AREA OF ISENTROPIC LIFT. AREA OF SHOWERS
MVG IN FM WRN NY ASSOC WITH FRONTAL BNDRY PUSHING EWRD. BACK EDGE
OF RAIN SHIELD IS HANDLED BEAUTIFULLY BY LATEST HRRR AND EXPECT
THIS TO BE ALONG THE I-81 CORRIDOR BY 07Z. CURRENT GRIDS REFLECT
THIS WELL AND THE ONLY CHG NEEDED WAS TO RMV THUNDER MENTION THRU
THE OVRNGT. NEAREST IN-CLOUD LIGHTNING STRIKES ARE DOWN ACRS THE
VA CAPES WITH LATEST GUIDANCE KEEPING SHOWALTERS WELL ABV ZERO
TONIGHT.
EXPECT LO CLDS TO LINGER THRU THE MRNG HRS WITH A BRIEF POTENTIAL
FOR PCLDY SKIES DRG THE MRNG HRS UNTIL PARENT H5 LOW DROPS ACRS NY
STATE DRG THE DAY. WITH LOW-LVL MOISTURE RMNG, ESPECIALLY IN CNTR
NY, SKIES WL CLD BACK UP BY NOON WITH POSSIBLE SHOWERS DVLPNG DRG
THE DAY.
PREV DISCUSSION BLO...
MID TO HI CLOUDS ARE RAPIDLY INCREASING OVER CENTRAL NY AND
NORTHEAST PA AS PER VISIBLE SATELLITE IMAGERY AS MOISTURE
STREAMS EASTWARD ALOFT AHEAD OF NEXT UPPER LEVEL WAVE AND
ASSOCIATED SURFACE SYSTEM. THIS UPPER LEVEL WAVE WAS SEEN WELL ON
THE WATER VAPOR IMAGERY OVER OHIO AND WAS MOVG EAST/NORTHEAST.
THERE WAS SIGNIFICANT MID TO HIGH LEVEL ISENTROPIC LIFT OR
ALTERNATELY WARM AIR ADVECTION FOR THOSE WHO LIKE PRESSURE
COORDINATES! WITH THIS, WAS ALSO SIGNIFICANT MOISTURE ADVECTION.
THE END RESULT WAS INCREASING MID TO HI CLDS THAT WILL CONTINUE
FOR THE REST OF THE AFTERNOON INTO THE EARLY EVENING HOURS. BY
00Z, THE POTENTIAL VORTICITY MAXIMUM WITH THE UPPER LEVEL WAVE
WILL REACH WRN PA TO WRN NY AND PROVIDE SIGNIFICANT MID LEVEL
LIFTG OF AIR THAT IS ALREADY RISING UP THE MOIST AND SATURATED
ADIABATS. THIS WILL USHER IN A STEADY RAIN FROM SW TO NE ACRS C
NY/NE PA BTWN ABT 22Z FROM SW STEUBEN CO TO WILKES BARRE TO 02Z IN
THE RME AREA. THIS UPPER LEVEL POTENTIAL VORTICITY MAX WILL BECOME
MORE STRETCHED AND ELONGATED IN TIME AS IT PASSES BY C NY/NE PA
BY 6Z-10Z TONIGHT. THE RAIN WILL TAPER OFF AT THIS TIME. MODELS
INDICATE SOME ELEVATED INSTABILITY LATER THIS EVENING WITH
SHOWALTER INDICES DROPPING TO NEAR OR BELOW 0C. SO I HAVE ADDED A
SLGHT CHC TO CHC OF THUNDER IN NE PA AND SC NY LATER IN THE
EVENING. PRECIP WINDS DOWN LATE TONIGHT.
FOR SATURDAY AM, THERE WILL BE PLENTY OF LOW CLOUDS AROUND AS WE
ARE IN BETWEEN THE FIRST UPPER WAVE HEADING TO OUR NORTHEAST AND
THE NEXT SIGNIFICANT UPPER LEVEL WAVE AND SIGNIFICANT SHOT OF COLD
AIR ADVECTION COMING FROM THE GREAT LAKES REGION. HENCE I SEE LOTS
OF LEFT OVER CLOUDS AROUND SAT AM. SHRA WILL DEVELOP BY SAT
PM, AS BNDRY LAYER HEATING COMBINES WITH COOLING ALOFT ARRIVING
WITH THIS NEXT SHOT OF COLD AIR ADVECTION AND LIFTG. HENCE I SEE
PLENTY OF SHRA DEVELOP BY AFTERNOON. SAT WILL BE COOL AND BREEZY
AS WELL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH THE FORECAST
SCENARIO THROUGH THIS PERIOD. UPPER LEVEL LOW PRESSURE WILL DIG
SOUTHEAST FROM THE NORTHERN GREAT LAKES TO SOUTHERN NEW ENGLAND
SATURDAY NIGHT ACCOMPANIED BY SCATTERED SHOWERS ESPECIALLY NORTH
OF THE NY/PA BORDER. A FEW SNOW FLAKES COULD MIX WITH THE RAIN
LATER SATURDAY NIGHT ESPECIALLY OVER HIGHER ELEVATIONS AS
TEMPERATURES WILL BECOME MARGINAL FOR SOME MIXED PRECIPITATION...
BUT NO ACCUMULATIONS ARE EXPECTED. PRECIPITATION AMOUNTS SATURDAY
NIGHT WILL BE LIGHT. LOW TEMPERATURES WILL BE IN THE 30S.
SCATTERED SHOWERS... SPRINKLES OF MORNING FLURRIES MAY LINGER FOR
AWHILE ON SUNDAY IN MOIST NNW FLOW PATTERN... ESPECIALLY OVER NY
STATE. 850 MB TEMPERATURES DOWN AROUND -4 C WILL NOT BE COLD
ENOUGH FOR ANY REAL LAKE ENHANCEMENT WITH LAKE ONTARIO TEMP STILL
AROUND +2... SO MAIN CONCENTRATION OF SHOWERS MAY BE INLAND FROM
THE FINGER LAKES TO THE SOUTHERN TIER OF NY... AS OPPOSED TO
FARTHER NORTH NEAR LAKE ONTARIO. DRY AIR ASSOCIATED WITH HIGH
PRESSURE OVER EASTERN CANADA WILL EVENTUALLY BREAK UP THE CLOUD
COVER ACROSS THE AREA DURING THE AFTERNOON OR EVENING HOURS.
TEMPERATURES SUNDAY WILL BE BELOW NORMAL WITH READINGS MAINLY IN
THE 50S.
AFTER A CLEAR CHILLY NIGHT SUNDAY NIGHT MONDAY WILL BE DRY WITH
NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES UNDER HIGH PRESSURE AT
THE SURFACE AND ALOFT. THE NEXT CHC OF RAIN WILL BE LATER MONDAY
NIGHT OR TUESDAY AS SURFACE THROUGH UPPER LEVEL LOW PRESSURE
APPROACHES FROM THE SOUTHWEST AND ISENTROPIC LIFT DEVELOPS WITH
INCREASING SW FLOW ALOFT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
320 AM UPDATE...MODELS CONTINUE TO BE IN EXCELLENT AGREEMENT
THROUGH THE MEDIUM RANGE AS AN UPPER LEVEL LOW AND ASSOCIATED SFC
FEATURE SLOWLY TRACK FROM THE MID WEST NORTHEAST INTO THE GREAT
LAKES REGION AND EVENTUALLY EASTERN CANADA. A PROLONGED PERIOD OF
SHOWERS AND COOL WEATHER IS EXPECTED WITH THIS PATTERN. RAISED
POPS INTO THE LIKELY CATEGORY FROM TUESDAY THROUGH WEDNESDAY NIGHT
WITH CHANCE POPS CONTINUING THROUGH FRIDAY.
PREVIOUS DISC...
A STRONG HIGH PRESSURE RIDGE DEVELOPING OVER CENTRAL CANADA WILL
FAVOR UPPER LEVEL LOW PRESSURE TO THE SOUTH-SOUTHEAST OVER THE
CENTRAL AND EASTERN U.S. THROUGH THIS PERIOD. GFS/ECMWF HAVE BEEN
ADVERTISING THIS PATTERN FOR QUITE SOME TIME NOW AND THERE IS HIGH
CONFIDENCE FOR A GENERALLY UNSETTLED PERIOD OF WEATHER DURING THE
MIDDLE AND LATE PART OF NEXT WEEK... ALTHOUGH THE DETAILS OF
COURSE REMAIN VERY UNCLEAR AT THIS TIME RANGE. CURRENT FORECAST
INDICATING AT LEAST A CHC OF SHOWERS EACH DAY FROM TUESDAY THROUGH
FRIDAY APPEARS REASONABLE. TEMPERATURES LOOK TO BE AT LEAST A
LITTLE BELOW NORMAL THROUGH THIS PERIOD... ALTHOUGH HOW FAR BELOW
NORMAL WILL DEVELOP ON EXACTLY WHERE THE UPPER LOW DEVELOPS.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
SFC COLD FRONT HAS CLEARED MOST TAF SITES AND WILL PASS THROUGH
KRME/KAVP DURING THE NEXT COUPLE OF HOURS. BEHIND BOUNDARY
WIDESPREAD IFR CIGS ARE EXPECTED UNTIL 12Z EXCEPT FOR KAVP.
BETWEEN 12Z-16Z CONDITIONS WILL GENERALLY IMPROVE TO VFR BUT A MID
LEVEL SHORT WAVE WILL PRODUCE SCATTERED SHOWERS DURING THE
AFTERNOON WITH BRIEF MVFR CONDITIONS POSSIBLE AT ALL SITES BUT
KELM/KAVP. THIS EVENING COLD NORTHWEST UPSLOPE FLOW WILL RESULT IN
WIDESPREAD MVFR CIGS EXCEPT VFR AT KELM/KAVP.
WINDS BECOMING WESTERLY EARLY THIS MORNING AT 10-12 KNOTS THEN
INCREASING BY MID MORNING TO 12-15 KNOTS WITH GUSTS 20-25 KNOTS.
WINDS DECREASING TO AROUND 10 KNOTS BY 00Z.
OUTLOOK...
SUN-MON...VFR.
TUE AND WED...RESTRICTIONS POSSIBLE IN RAIN SHOWERS.
&&
.FIRE WEATHER...
RAINFALL HAS MOVED INTO NORTHEAST PENNSYLVANIA THIS EVENING WITH
AMOUNTS RANGING FROM A FEW HUNDREDTHS OF AN INCH TO A TENTH OF AN
INCH. WITH SHOWERS EXPECTED TONIGHT AND AGAIN SATURDAY, NO THREAT
FOR FIRE WEATHER CONDITIONS EXIST THROUGH THE WEEKEND.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE/TAC
NEAR TERM...DJN/PVN
SHORT TERM...MSE
LONG TERM...MSE/RRM
AVIATION...RRM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
158 AM EDT SAT APR 26 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK EAST ACROSS THE AREA TONIGHT
BRINGING SOME SHOWERS. A FEW SHOWERS WILL LINGER SATURDAY AND
SATURDAY NIGHT AS UPPER LEVEL LOW PRESSURE MOVES ACROSS THE AREA.
HIGH PRESSURE OVER EASTERN CANADA WILL BRING A RETURN TO MAINLY
DRY WEATHER SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
810 PM UPDATE...
NUMEROUS LOPRES CNTRS ON SFC ANALYSIS THIS EVNG, ONE OVR UP OF
MICHIGAN, ANOTHER OVR WRN NY AND YET ANOTHER DOWN OVR THE PIEDMONT
OF NC. TWO AREAS OF SHOWERS AFFECTING CWA AT THIS TIME, WITH FIRST
BATCH HVG MVD UP FM PA IN AREA OF ISENTROPIC LIFT. AREA OF SHOWERS
MVG IN FM WRN NY ASSOC WITH FRONTAL BNDRY PUSHING EWRD. BACK EDGE
OF RAIN SHIELD IS HANDLED BEAUTIFULLY BY LATEST HRRR AND EXPECT
THIS TO BE ALONG THE I-81 CORRIDOR BY 07Z. CURRENT GRIDS REFLECT
THIS WELL AND THE ONLY CHG NEEDED WAS TO RMV THUNDER MENTION THRU
THE OVRNGT. NEAREST IN-CLOUD LIGHTNING STRIKES ARE DOWN ACRS THE
VA CAPES WITH LATEST GUIDANCE KEEPING SHOWALTERS WELL ABV ZERO
TONIGHT.
EXPECT LO CLDS TO LINGER THRU THE MRNG HRS WITH A BRIEF POTENTIAL
FOR PCLDY SKIES DRG THE MRNG HRS UNTIL PARENT H5 LOW DROPS ACRS NY
STATE DRG THE DAY. WITH LOW-LVL MOISTURE RMNG, ESPECIALLY IN CNTR
NY, SKIES WL CLD BACK UP BY NOON WITH POSSIBLE SHOWERS DVLPNG DRG
THE DAY.
PREV DISCUSSION BLO...
MID TO HI CLOUDS ARE RAPIDLY INCREASING OVER CENTRAL NY AND
NORTHEAST PA AS PER VISIBLE SATELLITE IMAGERY AS MOISTURE
STREAMS EASTWARD ALOFT AHEAD OF NEXT UPPER LEVEL WAVE AND
ASSOCIATED SURFACE SYSTEM. THIS UPPER LEVEL WAVE WAS SEEN WELL ON
THE WATER VAPOR IMAGERY OVER OHIO AND WAS MOVG EAST/NORTHEAST.
THERE WAS SIGNIFICANT MID TO HIGH LEVEL ISENTROPIC LIFT OR
ALTERNATELY WARM AIR ADVECTION FOR THOSE WHO LIKE PRESSURE
COORDINATES! WITH THIS, WAS ALSO SIGNIFICANT MOISTURE ADVECTION.
THE END RESULT WAS INCREASING MID TO HI CLDS THAT WILL CONTINUE
FOR THE REST OF THE AFTERNOON INTO THE EARLY EVENING HOURS. BY
00Z, THE POTENTIAL VORTICITY MAXIMUM WITH THE UPPER LEVEL WAVE
WILL REACH WRN PA TO WRN NY AND PROVIDE SIGNIFICANT MID LEVEL
LIFTG OF AIR THAT IS ALREADY RISING UP THE MOIST AND SATURATED
ADIABATS. THIS WILL USHER IN A STEADY RAIN FROM SW TO NE ACRS C
NY/NE PA BTWN ABT 22Z FROM SW STEUBEN CO TO WILKES BARRE TO 02Z IN
THE RME AREA. THIS UPPER LEVEL POTENTIAL VORTICITY MAX WILL BECOME
MORE STRETCHED AND ELONGATED IN TIME AS IT PASSES BY C NY/NE PA
BY 6Z-10Z TONIGHT. THE RAIN WILL TAPER OFF AT THIS TIME. MODELS
INDICATE SOME ELEVATED INSTABILITY LATER THIS EVENING WITH
SHOWALTER INDICES DROPPING TO NEAR OR BELOW 0C. SO I HAVE ADDED A
SLGHT CHC TO CHC OF THUNDER IN NE PA AND SC NY LATER IN THE
EVENING. PRECIP WINDS DOWN LATE TONIGHT.
FOR SATURDAY AM, THERE WILL BE PLENTY OF LOW CLOUDS AROUND AS WE
ARE IN BETWEEN THE FIRST UPPER WAVE HEADING TO OUR NORTHEAST AND
THE NEXT SIGNIFICANT UPPER LEVEL WAVE AND SIGNIFICANT SHOT OF COLD
AIR ADVECTION COMING FROM THE GREAT LAKES REGION. HENCE I SEE LOTS
OF LEFT OVER CLOUDS AROUND SAT AM. SHRA WILL DEVELOP BY SAT
PM, AS BNDRY LAYER HEATING COMBINES WITH COOLING ALOFT ARRIVING
WITH THIS NEXT SHOT OF COLD AIR ADVECTION AND LIFTG. HENCE I SEE
PLENTY OF SHRA DEVELOP BY AFTERNOON. SAT WILL BE COOL AND BREEZY
AS WELL.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH THE FORECAST
SCENARIO THROUGH THIS PERIOD. UPPER LEVEL LOW PRESSURE WILL DIG
SOUTHEAST FROM THE NORTHERN GREAT LAKES TO SOUTHERN NEW ENGLAND
SATURDAY NIGHT ACCOMPANIED BY SCATTERED SHOWERS ESPECIALLY NORTH
OF THE NY/PA BORDER. A FEW SNOW FLAKES COULD MIX WITH THE RAIN
LATER SATURDAY NIGHT ESPECIALLY OVER HIGHER ELEVATIONS AS
TEMPERATURES WILL BECOME MARGINAL FOR SOME MIXED PRECIPITATION...
BUT NO ACCUMULATIONS ARE EXPECTED. PRECIPITATION AMOUNTS SATURDAY
NIGHT WILL BE LIGHT. LOW TEMPERATURES WILL BE IN THE 30S.
SCATTERED SHOWERS... SPRINKLES OF MORNING FLURRIES MAY LINGER FOR
AWHILE ON SUNDAY IN MOIST NNW FLOW PATTERN... ESPECIALLY OVER NY
STATE. 850 MB TEMPERATURES DOWN AROUND -4 C WILL NOT BE COLD
ENOUGH FOR ANY REAL LAKE ENHANCEMENT WITH LAKE ONTARIO TEMP STILL
AROUND +2... SO MAIN CONCENTRATION OF SHOWERS MAY BE INLAND FROM
THE FINGER LAKES TO THE SOUTHERN TIER OF NY... AS OPPOSED TO
FARTHER NORTH NEAR LAKE ONTARIO. DRY AIR ASSOCIATED WITH HIGH
PRESSURE OVER EASTERN CANADA WILL EVENTUALLY BREAK UP THE CLOUD
COVER ACROSS THE AREA DURING THE AFTERNOON OR EVENING HOURS.
TEMPERATURES SUNDAY WILL BE BELOW NORMAL WITH READINGS MAINLY IN
THE 50S.
AFTER A CLEAR CHILLY NIGHT SUNDAY NIGHT MONDAY WILL BE DRY WITH
NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES UNDER HIGH PRESSURE AT
THE SURFACE AND ALOFT. THE NEXT CHC OF RAIN WILL BE LATER MONDAY
NIGHT OR TUESDAY AS SURFACE THROUGH UPPER LEVEL LOW PRESSURE
APPROACHES FROM THE SOUTHWEST AND ISENTROPIC LIFT DEVELOPS WITH
INCREASING SW FLOW ALOFT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
A STRONG HIGH PRESSURE RIDGE DEVELOPING OVER CENTRAL CANADA WILL
FAVOR UPPER LEVEL LOW PRESSURE TO THE SOUTH-SOUTHEAST OVER THE
CENTRAL AND EASTERN U.S. THROUGH THIS PERIOD. GFS/ECMWF HAVE BEEN
ADVERTISING THIS PATTERN FOR QUITE SOME TIME NOW AND THERE IS HIGH
CONFIDENCE FOR A GENERALLY UNSETTLED PERIOD OF WEATHER DURING THE
MIDDLE AND LATE PART OF NEXT WEEK... ALTHOUGH THE DETAILS OF
COURSE REMAIN VERY UNCLEAR AT THIS TIME RANGE. CURRENT FORECAST
INDICATING AT LEAST A CHC OF SHOWERS EACH DAY FROM TUESDAY THROUGH
FRIDAY APPEARS REASONABLE. TEMPERATURES LOOK TO BE AT LEAST A
LITTLE BELOW NORMAL THROUGH THIS PERIOD... ALTHOUGH HOW FAR BELOW
NORMAL WILL DEVELOP ON EXACTLY WHERE THE UPPER LOW DEVELOPS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SFC COLD FRONT HAS CLEARED MOST TAF SITES AND WILL PASS THROUGH
KRME/KAVP DURING THE NEXT COUPLE OF HOURS. BEHIND BOUNDARY
WIDESPREAD IFR CIGS ARE EXPECTED UNTIL 12Z EXCEPT FOR KAVP.
BETWEEN 12Z-16Z CONDITIONS WILL GENERALLY IMPROVE TO VFR BUT A MID
LEVEL SHORT WAVE WILL PRODUCE SCATTERED SHOWERS DURING THE
AFTERNOON WITH BRIEF MVFR CONDITIONS POSSIBLE AT ALL SITES BUT
KELM/KAVP. THIS EVENING COLD NORTHWEST UPSLOPE FLOW WILL RESULT IN
WIDESPREAD MVFR CIGS EXCEPT VFR AT KELM/KAVP.
WINDS BECOMING WESTERLY EARLY THIS MORNING AT 10-12 KNOTS THEN
INCREASING BY MID MORNING TO 12-15 KNOTS WITH GUSTS 20-25 KNOTS.
WINDS DECREASING TO AROUND 10 KNOTS BY 00Z.
OUTLOOK...
SUN-MON...VFR.
TUE AND WED...RESTRICTIONS POSSIBLE IN RAIN SHOWERS.
&&
.FIRE WEATHER...
RAINFALL HAS MOVED INTO NORTHEAST PENNSYLVANIA THIS EVENING WITH
AMOUNTS RANGING FROM A FEW HUNDREDTHS OF AN INCH TO A TENTH OF AN
INCH. WITH SHOWERS EXPECTED TONIGHT AND AGAIN SATURDAY, NO THREAT
FOR FIRE WEATHER CONDITIONS EXIST THROUGH THE WEEKEND.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE/TAC
NEAR TERM...DJN/PVN
SHORT TERM...MSE
LONG TERM...MSE
AVIATION...RRM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
933 PM CDT SUN APR 27 2014
.UPDATE...
ISSUED AT 933 PM CDT SUN APR 27 2014
FORECAST IS UNFOLDING AS EXPECTED. THE ONLY UPDATE WILL BE TO
INDICATE A BRIEF BREAK IN ACTIVITY WITH 30% POPS. THE REGION WILL
REMAIN WITHIN THE TROWAL (WHICH WILL GRADUALLY LIFT NORTH
OVERNIGHT). WE KNOW THAT RAIN WILL OCCUR WITHIN THIS FEATURE...AND
ALL AREAS WILL RECEIVE RAINFALL. THE HARD PART IS ATTEMPTING TO
FORECAST EXACTLY WHEN AND WHERE WAVES ROTATING AROUND THE MAIN
UPPER LOW WILL INFLUENCE AREAS WITHIN THE TROWAL. THE HRRR DID A
GOOD JOB LAST NIGHT...AND WILL FOLLOW AS GUIDANCE FOR TONIGHT. THE
RAIN ACROSS THE SOUTHERN FA WILL LIFT NORTH OVERNIGHT...AND
ANTICIPATE A BREAK IN ACTIVITY ONCE THIS ACTIVITY MOVES TO THE
NORTH. ADJUSTED POPS FOR THIS THINKING. THE NEXT WAVE...OR AREA OF
FORCING...IS ASSOCIATED WITH THE ACTIVITY JUST ENTERING SOUTHERN
IOWA. THIS ACTIVITY SHOULD EXPAND TO THE NORTHWEST
OVERNIGHT...ENTERING WEST CENTRAL MINNESOTA 10Z-12Z...THEN
EXPANDING INTO MUCH OF THE FA AFTER 12Z MONDAY MORNING (CONTINUING
THROUGH MUCH OF THE DAY...STARTING TO DRY FROM THE NORTHEAST BY
LATE AFTERNOON).
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 343 PM CDT SUN APR 27 2014
CHALLENGES INCLUDE WINDS LATE THIS AFTERNOON AND EVENING AND THEN
PRECIP CHANCES/TYPE/AMOUNTS THROUGH THE REMAINDER OF THE FORECAST
PERIOD. WILL USE RAP/HRRR FOR THE NEXT 6 TO 12 HOURS AND THEN
TRANSITION TO A GLOBAL MODEL BLEND THEREAFTER AS GFS/NAM/ECMWF/
GEM ARE IN RELATIVELY GOOD AGREEMENT.
IN THE NEAR TERM...WILL LET WIND ADVISORY CONTINUE UNTIL 7 PM CDT.
MOST AREAS WON/T HIT CRITERIA...BUT FINALLY STARTING TO SEE SOME
MORE WIDESPREAD OBSERVATIONS AT OR ABOVE 30 MPH.
20 UTC WATER VAPOR LOOP SHOWS PRIMARY VORTICITY MAXIMA ACROSS
WESTERN KS WITH A STRONG SHORT-WAVE ROTATING OUT OF ITS BASE.
STRONG WARM AIR AND MOISTURE ADVECTION (PWATS TO ONE INCH) ALONG
THE 850 HPA SFC THIS EVENING AND OVERNIGHT...COMBINED WITH
DIVERGENT FLOW ALOFT WILL RESULT IN INCREASING SHOWERS MOVING FROM
SOUTH TO NORTH. ADDED THUNDER BACK INTO THE FORECAST ACROSS THE
SOUTH THIS EVENING WITH ISOLATED LIGHTNING STRIKES ALONG THE ND/SD
BORDER. INSTABILITY IS MINIMAL...BUT SPC MESOANALYSIS SHOWS A
COUPLE HUNDRED JOULES OF MOST UNSTABLE CAPE. THERMAL PROFILES WARM
ENOUGH TONIGHT FOR ALL RAIN...BUT COULD SEE A FEW FLAKES IN THE
MIX.
WILL LIFT CATEGORICAL POPS TO THE NORTH TONIGHT AND MONDAY. MONDAY
WILL BE CLOUDY AND COOL WITH PERIODS OF LIGHT TO MODERATE RAIN
SHOWERS. TEMPERATURES WILL RISE INTO THE UPPER 30S TO MID 40S WITH
PERSISTENT BREEZY EASTERLY WIND. 850 HPA TEMPERATURES BEGIN TO
FALL BELOW FREEZING MONDAY NIGHT WITH MOST OF THE COLUMN BELOW 0 C
BY TUESDAY MORNING EXCEPT THE NEAR SFC LAYER. PTYPE WILL DEPEND
HEAVILY ON SFC TEMPERATURES...BUT WITH FORECAST VALUES PLUS OR
MINUS A FEW DEGREES AROUND FREEZING MONDAY NIGHT...WILL KEEP A
RAIN/SNOW MIX IN THE WEATHER GRIDS. NOT REALLY EXPECTING MUCH
ACCUMULATION AS MOST SNOW THAT DOES FALL SHOULD MELT ON CONTACT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 343 PM CDT SUN APR 27 2014
STRONG DRYING WILL WORK ITS WAY SOUTH ON TUESDAY AS THE LOW
PRESSURE SYSTEM SCOOTS ACROSS IA INTO WI. SHOULD SEE A BREAK IN
PRECIP...ESPECIALLY FOR THE CENTRAL AND NORTHERN FORECAST AREA.
COULD EVEN SEE SOME PEAKS OF SUN. PTYPE SHOULD BE MOSTLY RAIN WITH
HIGHS RISING INTO THE MID TO UPPER 40S. WINDS WILL REMAIN BREEZY
AND SHIFT TO THE NORTH.
WRAP AROUND PRECIP WILL RETURN WEDNESDAY AS THE LOW WOBBLES ACROSS
WI WITH A GREATER CHANCE FOR A RAIN/SNOW MIX OR EVEN ALL SNOW AT
TIMES GIVEN A SATURATED SUB-FREEZING COLUMN. PTYPE WILL AGAIN
DEPEND ON SFC TEMPERATURES WITH MINIMAL ACCUMULATIONS. WHEN ALL IS
SAID AND DONE...LIQUID ACCUMULATIONS OVER THE 2 TO 3 DAY PERIOD
WILL BE 1 TO 2 INCHES WITH LOCALLY HIGHER AMOUNTS IN HEAVIER
SHOWERS OR THUNDERSTORMS. ANY SNOW ACCUMULATION SHOULD BE CONFINED
MAINLY TO THE HIGHER TERRAIN ON EITHER SIDE OF THE VALLEY BUT ONLY
AN INCH OR LESS.
UPPER LOW AND SURFACE LOW WILL REMAIN OVER THE GREAT LAKES WEDNESDAY
NIGHT INTO THURSDAY WITH NORTH WINDS AND SPOTTY RAIN SHOWERS ALONG
WITH CONTINUED WELL BELOW NORMAL TEMPERATURES. 12Z ECMWF/GFS ALL
INDICATE 500 MB TROUGH TO REMAIN IN PLACE WITH NEXT SHORT WAVE
DROPPING SOUTH INTO THE NRN PLAINS FRIDAY NIGHT-SATURDAY WITH
ANOTHER CHANCE OF SHOWERS. NO HEAVY RAINFALL THIS PERIOD BUT AT
LEAST A CHANCE FOR SHOWERS EACH DAY AND TEMPS REMAIN BELOW AVERAGE
INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 645 PM CDT SUN APR 27 2014
CONDITIONS ARE EXPECTED TO DETERIORATE THROUGH THE OVERNIGHT
HOURS...BUT BY HOW MUCH REMAINS THE QUESTION. LOW LEVEL EASTERLY
FLOW FROM A DRY AIRMASS WILL REMAIN THROUGH MUCH OF THE TAF
PERIOD...PUTTING INTO QUESTION EXACTLY HOW LOW CIGS WILL BECOME.
AS THE MORE STEADY RAIN MOVES INTO EACH SITE...EXPECT CIGS AND
VSBY TO LOWER...BUT NOT AS MUCH AS MOS GUIDANCE SUGGESTS.
ATTEMPTED TO FOLLOW MORE OF THE GRIDDED RAP GUIDANCE FOR
CIGS...AND THE RAP/HRRR FOR RAIN CHANCES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...ROGERS
LONG TERM...ROGERS/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1131 AM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 1131 AM CDT SAT APR 26 2014
QUICK UPDATE TO ISSUE A WIND ADVISORY FOR THE SOUTHWEST AND PARTS
OF SOUTH CENTRAL THROUGH MUCH OF THIS EVENING. WINDS HAVE
INCREASED IN THE SOUTHWEST...AND WERE HIGHER THAN PREVIOUSLY
FORECAST. ALSO...LATEST GUIDANCE INDICATES STRONGER WINDS AND
PERSISTING INTO THE EVENING.
UPDATE ISSUED AT 940 AM CDT SAT APR 26 2014
NARROW BAND OF SHOWERS NOW HAD ADVANCED NORTHWARD TO
WILLISTON...MCLEAN COUNTY (NORTH OF LAKE SAKAKAWEA) TO BETWEEN
BISMARCK AND JAMESTOWN. THE BISMARCK AIRPORT RECORDED 0.07 INCHES
OF RAIN AS THE PRECIP BAND WENT THROUGH. THE BAND CONTINUES
LIFTING NORTHWARD AND EXPECT A FEW HUNDREDTHS OF AN INCH TO
PERHAPS A TENTH OF AN INCH OF RAIN MOST AREAS. ADJUSTED TIMING OF
PRECIPITATION ACCORDINGLY. BY EARLY AFTERNOON THE PRECIPITATION
BAND SHOULD BE MAINLY NORTH OF THE CANADIAN BORDER...WITH THE
SOUTHEASTERN PORTION DISSIPATING. OTHERWISE FORECAST ON TRACK -
MINOR HOURLY ADJUSTMENTS FOR WIND AND TEMPERATURES.
UPDATE ISSUED AT 642 AM CDT SAT APR 26 2014
NARROW BAND OF SHOWERS FROM WEST CENTRAL INTO SOUTH CENTRAL NORTH
DAKOTA CONTINUES TO LIFT NORTH THIS MORNING. ONLY SOME SLIGHT
MODIFICATIONS TO THE CURRENT HRRR POP PLACEMENT TODAY. ALSO BUMPED
UP SKY COVER THROUGH THE MORNING SOUTHWEST BASED ON LATEST
SATELLITE IMAGERY. OTHERWISE CURRENT FORECAST LOOKS TO BE IN GOOD
SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT SAT APR 26 2014
THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL.
FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF
RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC
WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND
ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE
SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER
SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS
TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE
NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE
FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR
TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR
MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION
WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR
A WIND ADVISORY.
FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS
WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY
STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES
ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE
NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06
UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED
TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH
DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED
INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED
THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA .
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT SAT APR 26 2014
THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG
SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH
DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF
THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH
DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF
PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE
DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL
MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE
HIGHEST RAINFALL AMOUNTS.
STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH
AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF
MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING
THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER.
BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN
COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL
PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT
INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST
TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER
SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING
THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY
BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED
SYSTEM.
ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT
AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING
BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE
MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND
HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A
LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT
ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY
FOR ANY MENTION OF ACCUMULATIONS.
PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH.
ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE
FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC
FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO
MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE
POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT
ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION.
THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH
ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON
WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM
FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE
IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND.
ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE
EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE
POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC
DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE
RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM CDT SAT APR 26 2014
A NARROW BAND OF LIGHT RAIN SHOWERS HAS MOVED INTO WESTERN INTO
SOUTH CENTRAL NORTH DAKOTA AS OF 1130 UTC...AND WILL CONTINUE TO
MOVE NORTH-NORTHEAST THROUGH THE MORNING. RAIN SHOWER ACTIVITY IN
THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND
KMOT. STRONG EAST-SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE
EXPECTED FOR MUCH OF THE AREA TODAY. A LARGE STORM SYSTEM WILL
BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY
NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND
RAIN.
&&
.HYDROLOGY...
ISSUED AT 353 AM CDT SAT APR 26 2014
ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA
REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS
OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME
DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS
SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE
REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES
ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO
HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE
FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS
RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR
NDZ017>020-031>035-040>047-050.
&&
$$
UPDATE...JV
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...AYD
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
940 AM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 940 AM CDT SAT APR 26 2014
NARROW BAND OF SHOWERS NOW HAD ADVANCED NORTHWARD TO
WILLISTON...MCLEAN COUNTY (NORTH OF LAKE SAKAKAWEA) TO BETWEEN
BISMARCK AND JAMESTOWN. THE BISMARCK AIRPORT RECORDED 0.07 INCHES
OF RAIN AS THE PRECIP BAND WENT THROUGH. THE BAND CONTINUES
LIFTING NORTHWARD AND EXPECT A FEW HUNDREDTHS OF AN INCH TO
PERHAPS A TENTH OF AN INCH OF RAIN MOST AREAS. ADJUSTED TIMING OF
PRECIPITATION ACCORDINGLY. BY EARLY AFTERNOON THE PRECIPITATION
BAND SHOULD BE MAINLY NORTH OF THE CANADIAN BORDER...WITH THE
SOUTHEASTERN PORTION DISSIPATING. OTHERWISE FORECAST ON TRACK -
MINOR HOURLY ADJUSTMENTS FOR WIND AND TEMPERATURES.
UPDATE ISSUED AT 642 AM CDT SAT APR 26 2014
NARROW BAND OF SHOWERS FROM WEST CENTRAL INTO SOUTH CENTRAL NORTH
DAKOTA CONTINUES TO LIFT NORTH THIS MORNING. ONLY SOME SLIGHT
MODIFICATIONS TO THE CURRENT HRRR POP PLACEMENT TODAY. ALSO BUMPED
UP SKY COVER THROUGH THE MORNING SOUTHWEST BASED ON LATEST
SATELLITE IMAGERY. OTHERWISE CURRENT FORECAST LOOKS TO BE IN GOOD
SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT SAT APR 26 2014
THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL.
FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF
RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC
WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND
ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE
SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER
SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS
TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE
NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE
FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR
TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR
MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION
WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR
A WIND ADVISORY.
FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS
WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY
STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES
ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE
NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06
UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED
TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH
DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED
INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED
THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA .
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT SAT APR 26 2014
THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG
SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH
DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF
THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH
DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF
PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE
DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL
MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE
HIGHEST RAINFALL AMOUNTS.
STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH
AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF
MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING
THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER.
BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN
COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL
PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT
INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST
TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER
SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING
THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY
BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED
SYSTEM.
ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT
AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING
BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE
MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND
HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A
LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT
ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY
FOR ANY MENTION OF ACCUMULATIONS.
PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH.
ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE
FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC
FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO
MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE
POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT
ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION.
THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH
ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON
WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM
FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE
IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND.
ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE
EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE
POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC
DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE
RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM CDT SAT APR 26 2014
A NARROW BAND OF LIGHT RAIN SHOWERS HAS MOVED INTO WESTERN INTO
SOUTH CENTRAL NORTH DAKOTA AS OF 1130 UTC...AND WILL CONTINUE TO
MOVE NORTH-NORTHEAST THROUGH THE MORNING. RAIN SHOWER ACTIVITY IN
THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND
KMOT. STRONG EAST-SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE
EXPECTED FOR MUCH OF THE AREA TODAY. A LARGE STORM SYSTEM WILL
BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY
NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND
RAIN.
&&
.HYDROLOGY...
ISSUED AT 353 AM CDT SAT APR 26 2014
ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA
REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS
OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME
DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS
SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE
REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES
ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO
HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE
FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS
RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...AYD
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 AM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 642 AM CDT SAT APR 26 2014
NARROW BAND OF SHOWERS FROM WEST CENTRAL INTO SOUTH CENTRAL NORTH
DAKOTA CONTINUES TO LIFT NORTH THIS MORNING. ONLY SOME SLIGHT
MODIFICATIONS TO THE CURRENT HRRR POP PLACEMENT TODAY. ALSO BUMPED
UP SKY COVER THROUGH THE MORNING SOUTHWEST BASED ON LATEST
SATELLITE IMAGERY. OTHERWISE CURRENT FORECAST LOOKS TO BE IN GOOD
SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT SAT APR 26 2014
THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL.
FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF
RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC
WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND
ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE
SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER
SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS
TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE
NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE
FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR
TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR
MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION
WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR
A WIND ADVISORY.
FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS
WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY
STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES
ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE
NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06
UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED
TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH
DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED
INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED
THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA .
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT SAT APR 26 2014
THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG
SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH
DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF
THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH
DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF
PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE
DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL
MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE
HIGHEST RAINFALL AMOUNTS.
STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH
AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF
MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING
THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER.
BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN
COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL
PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT
INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST
TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER
SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING
THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY
BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED
SYSTEM.
ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT
AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING
BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE
MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND
HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A
LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT
ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY
FOR ANY MENTION OF ACCUMULATIONS.
PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH.
ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE
FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC
FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO
MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE
POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT
ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION.
THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH
ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON
WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM
FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE
IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND.
ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE
EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE
POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC
DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE
RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM CDT SAT APR 26 2014
A NARROW BAND OF LIGHT RAIN SHOWERS HAS MOVED INTO WESTERN INTO
SOUTH CENTRAL NORTH DAKOTA AS OF 1130 UTC...AND WILL CONTINUE TO
MOVE NORTH-NORTHEAST THROUGH THE MORNING. RAIN SHOWER ACTIVITY IN
THE AFTERNOON IS EXPECTED TO LARGELY REMAIN NORTH OF KISN AND
KMOT. STRONG EAST-SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE
EXPECTED FOR MUCH OF THE AREA TODAY. A LARGE STORM SYSTEM WILL
BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY
NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND
RAIN.
&&
.HYDROLOGY...
ISSUED AT 353 AM CDT SAT APR 26 2014
ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA
REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS
OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME
DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS
SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE
REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES
ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO
HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE
FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS
RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...AYD
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
356 AM CDT SAT APR 26 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT SAT APR 26 2014
THE HIGHLIGHT OF THE SHORT TERM IS PRECIPITATION POTENTIAL.
FOR TODAY...THE HRRR HAS HAD A GOOD HANDLE ON THE NARROW BAND OF
RAIN SHOWERS MOVING INTO SOUTHWEST NORTH DAKOTA AS OF 0830 UTC
WITH THE LEADING SHORTWAVE. THUS...WILL FOLLOW THE 07 UTC HRRR AND
ITS PARENT RAP FOR POPS THIS MORNING AND INTO THE AFTERNOON. THESE
SOLUTIONS ARE IN AGREEMENT WITH THE 00 UTC 4 KM WRF AND LARGER
SCALE DETERMINISTIC GUIDANCE WHICH QUICKLY MOVE THE RAIN SHOWERS
TO THE INTERNATIONAL BORDER BY EARLY AFTERNOON. THUS...AFTER THE
NARROW BAND OF SHOWERS PASS...THE DAY SHOULD BE PRECIPITATION FREE
FOR NEARLY ALL OF THE CWA. IN REGARDS TO WINDS FOR
TODAY...EXPECT WIDESPREAD EAST-SOUTHEAST GUSTS OF 30-35 KTS FOR
MOST AREAS. HOWEVER...A LOW LEVEL INVERSION IN WARM AIR ADVECTION
WILL LIMIT THE TRANSFER OF HIGHER MOMENTUM AND FORGO THE NEED FOR
A WIND ADVISORY.
FOR TONIGHT...SURFACE LOW PRESSURE CONTINUES TO DEEPEN ACROSS
WESTERN NEBRASKA...AS THE OVERALL SYSTEM BECOMES NEARLY VERTICALLY
STACKED LATE TONIGHT AS THE POTENT UPPER LEVEL WAVE PROPAGATES
ONTO THE PLAINS. RESULTING MOISTURE TRANSPORT INCREASES ACROSS THE
NORTHERN PLAINS...WITH RAIN SHOWER COVERAGE INCREASING AFTER 06
UTC ACROSS WESTERN NORTH DAKOTA IN THE VICINITY OF THE INVERTED
TROUGH EXTENDING INTO EASTERN MONTANA...AND ACROSS SOUTHERN NORTH
DAKOTA IN LOW LEVEL WARM AIR ADVECTION. THE BULK OF ELEVATED
INSTABILITY TONIGHT REMAINS IN SOUTH DAKOTA...HOWEVER AN EMBEDDED
THUNDERSTORM IS POSSIBLE ACROSS FAR SOUTH CENTRAL NORTH DAKOTA .
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT SAT APR 26 2014
THE MAIN FORECAST PROBLEM IN THE EXTENDED PERIOD WILL BE THE STRONG
SPRING STORM SYSTEM AFFECTING ALL OF WESTERN AND CENTRAL NORTH
DAKOTA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE TRACK OF
THE SURFACE AND UPPER LEVEL FEATURES THROUGH TUESDAY...WITH
DIFFERENCES INCREASING THEREAFTER. STILL SOME DIFFERENCES IN QPF
PATTERN THROUGH THE EVOLUTION OF THE SYSTEM WITH THE GFS BEING THE
DRIEST ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA. ALL
MODELS HOWEVER ARE PINPOINTING THE FAR SOUTHWEST WITH SOME OF THE
HIGHEST RAINFALL AMOUNTS.
STRONG SHORTWAVE JUST MOVING ONTO THE SOUTHERN CALIFORNIA COAST WITH
AN UPPER LEVEL LOW CLOSING OFF JUST TO ITS NORTH. BROAD FETCH OF
MOISTURE IN SOUTHWEST UPPER FLOW INTO THE NORTHERN PLAINS...SETTING
THE STAGE FOR AN EXTENDED PERIOD OF RAINY WEATHER.
BY SUNDAY MORNING THE UPPER LOW IS PROGGED TO BE OVER EASTERN
COLORADO WITH A RAPIDLY DEEPENING SURFACE SYSTEM OVER THE CENTRAL
PLAINS. THE INITIAL SURGE OF ENERGY MOVES INTO THE AREA LATE TONIGHT
INTO SUNDAY MORNING. ALTHOUGH BEST ELEVATED INSTABILITY REMAINS JUST
TO OUR SOUTH...SYSTEM IS STRONG ENOUGH THAT A MENTION OF THUNDER
SEEMED WARRANTED SUNDAY MORNING. BEST PRECIPITATION CHANCES DURING
THE DAY WILL BE OVER THE SOUTHWEST HALF OF THE CWA...AND THERE MAY
BE PERIODS OF NO RAIN AS WELL AS DRIER AIR WRAPS AROUND THE STACKED
SYSTEM.
ANOTHER STRONG IMPULSE LIFTS THROUGH THE AREA SUNDAY NIGHT
AS THE UPPER LOW REACHES ITS FARTHEST POINT NORTH BEFORE WOBBLING
BACK SOUTH ON MONDAY. BY THIS TIME CHANCES OF CONVECTION WILL BE
MINIMAL AS COOLER AIR GETS PULLED INTO THE SYSTEM. THE FAR NORTH AND
HIGHER ELEVATIONS IN THE FAR WEST COULD SEE PERIODS OF SNOW LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING. LATEST MODEL RUNS ARE A
LITTLE COOLER IN THE WEST SO WILL NEED TO MONITOR FOR SOME LIGHT
ACCUMULATING SNOWS IN THE FAR WEST...BUT AT THIS TIME ITS TOO EARLY
FOR ANY MENTION OF ACCUMULATIONS.
PRECIPITATION BEGINS TO WANE ON MONDAY AS THE LOW DROPS SOUTH.
ALTHOUGH LOW LEVEL FORCING WILL BE ON THE DECREASE...SYNOPTIC SCALE
FORCING WILL REMAIN THROUGH TUESDAY AS WE REMAIN UNDER THE CYCLONIC
FLOW OF THE UPPER LEVEL LOW. THUS LIKELY POPS REMAIN MONDAY INTO
MONDAY NIGHT...WITH HIGH CHANCE POPS TUESDAY. AGAIN WE WILL SEE THE
POSSIBILITY OF SNOW MONDAY NIGHT INTO TUESDAY MORNING...AND LIGHT
ACCUMULATIONS ARE CERTAINLY NOT OUT OF THE QUESTION.
THE UPPER LOW LIFTS BACK NORTHWARD TUESDAY NIGHT INTO WEDNESDAY WITH
ANOTHER WAVE OF MOISTURE SWINGING EAST TO WEST ACROSS THE AREA ON
WEDNESDAY BRINGING A CHANCE OF RAIN OR SNOW SHOWERS. THE SYSTEM
FINALLY EXITS THE ARE LATE IN THE WORK WEEK...WITH ANOTHER IMPULSE
IN A NORTHWEST FLOW PATTERN POSSIBLE BY NEXT WEEKEND.
ALL IN ALL A WET AND COOL PERIOD IS IN STORE THROUGH MOST OF THE
EXTENDED PERIOD. WILL ISSUE A HYDROLOGIC STATEMENT MENTIONING THE
POSSIBILITY OF FLOODING DUE TO AN EXTENDED PERIOD OF RAIN. WPC
DEPICTS PORTIONS OF THE SOUTHWEST WITH A SLIGHT CHANCE OF EXCESSIVE
RAINFALL 12Z SUNDAY THROUGH 12Z MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 353 AM CDT SAT APR 26 2014
LIGHT RAIN SHOWERS HAVE MOVED INTO SOUTHWEST NORTH DAKOTA AS OF
830 UTC...AND WILL CONTINUE TO MOVE NORTH-NORTHEAST THROUGH
SATURDAY MORNING. RAIN SHOWER ACTIVITY IN THE AFTERNOON IS
EXPECTED TO LARGELY REMAIN NORTH OF KISN AND KMOT. STRONG EAST-
SOUTHEAST WINDS WITH GUSTS OF 30-35 KTS ARE EXPECTED FOR MUCH OF
THE AREA TODAY. A LARGE STORM SYSTEM WILL BEGIN TO IMPACT WESTERN
AND CENTRAL NORTH DAKOTA SATURDAY NIGHT...WITH CONDITIONS TRENDING
TOWARDS MVFR/IFR IN STRATUS AND RAIN.
&&
.HYDROLOGY...
ISSUED AT 353 AM CDT SAT APR 26 2014
ISSUED A HYDROLOGIC OUTLOOK...ESF...FOR WESTERN NORTH DAKOTA
REGARDING THE UPCOMING HEAVY RAIN EVENT AND POTENTIAL IMPACTS. AS
OF NOW...THE 00 UTC DETERMINISTIC SUITE REMAINS IN SOME
DISAGREEMENT ON THE PLACEMENT OF THE HEAVIEST QPF AXIS. THIS HAS
SIGNIFICANT IMPACTS IN BASIN HYDROLOGIC RESPONSE. FURTHERMORE...THE
REMOVAL OF FROST FROM THE GROUND AND RECENT DRY WEATHER PLACES
ADDITIONAL UNCERTAINTY IN HOW MUCH WATER THE SOILS WILL BE ABLE TO
HOLD. THAT SAID...RIVER AND STREAM RISES...POTENTIALLY ABOVE
FLOOD STAGE...ARE POSSIBLE. HOWEVER...WHICH SPECIFIC WATERWAYS
RESPOND THE MOST IS HIGHLY DEPENDENT ON QPF PLACEMENT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...AYD
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
108 AM CDT SAT APR 26 2014
.UPDATE...
ISSUED AT 107 AM CDT SAT APR 26 2014
FOLLOWED THE TREND OF THE 02 THROUGH 04 UTC HRRR RUNS FOR POPS THE
REMAINDER OF THE NIGHT...WHICH IS TO SCALE BACK THE OVERALL
COVERAGE AND INTENSITY OF RAIN. THIS IS ALSO IN LINE WITH THE
LARGER SCALE 00 UTC DETERMINISTIC MODELS.
UPDATE ISSUED AT 920 PM CDT FRI APR 25 2014
LATE EVENING UPDATE FOR MINOR CHANGES TO POPS FOR THE OVERNIGHT
HOURS. A SHORTWAVE TROUGH WILL LIFT NORTHEAST THROUGH THE REGION
OVERNIGHT INTO SATURDAY MORNING...SUPPORTING AN AREA OF SHOWERS.
MUCH OF THE RAIN SHOULD OCCUR PRIOR TO MIDDAY...WITH ONLY ISOLATED
SHOWERS DURING THE AFTERNOON. WINDS MAY APPROACH ADVISORY CRITERIA
SATURDAY...ESPECIALLY ACROSS THE SOUTHWEST.
UPDATE ISSUED AT 623 PM CDT FRI APR 25 2014
NO SIGNIFICANT CHANGES FOR EARLY EVENING UPDATE. A BAND OF SHOWERS
IS EXPECTED TO LIFT INTO SOUTHERN NORTH DAKOTA DURING THE EARLY
MORNING HOURS...AND CONTINUE TO LIFT NORTH ACROSS THE REST OF THE
FORECAST AREA SATURDAY MORNING. SHOWERS WILL DIMINISH ACROSS THE
NORTH SATURDAY AFTERNOON...FOLLOWED BY MORE SUBSTANTIAL RAINFALL
LATE SATURDAY NIGHT AND SUNDAY.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 235 PM CDT FRI APR 25 2014
FRIDAY AFTERNOON...A FRONTAL BOUNDARY EXTENDED FROM NORTHEAST
MONTANA ACROSS WEST CENTRAL NORTH DAKOTA INTO THE SOUTHEAST. NORTH
OF THIS FRONT COOL AIR AND CLOUDS COVERED THE NORTH CENTRAL KEEPING
THIS REGION QUITE COOL FRIDAY. TONIGHT...THE LOCATION OF THIS FRONT
WILL PLAY AN IMPORTANT ROLE IN THE LOCATION OF THE SHOWERS AND
THUNDERSTORMS. FOR THE REST OF THIS AFTERNOON...WIND CONVERGENCE
WAS RESPONSIBLE FOR INCREASING CUMULUS CLOUDS ACROSS THE FRONTAL
ZONE IN NORTHWEST NORTH DAKOTA. SEEING SOME SCATTERED SHOWERS IN
NORTHEAST MONTANA AND WILL ADD A LATE AFTERNOON/EVENING PERIOD FOR
SHOWERS NORTHWEST.
TONIGHT...THE ONSET OF SHOWERS ACROSS THE SOUTHWEST SHOULD BEGIN MID
EVENING AS THE EVENING SHOWERS ACROSS THE NORTHWEST FADE AWAY
AFTER PEAK HEATING. PLACED THE BOUNDARY FOR THUNDERSTORMS ACROSS
THE FAR SOUTHWEST TONIGHT AND THE SOUTH CENTRAL SATURDAY FOLLOWING
THE 1KM MIXED LAYER CAPE. SEE LITTLE IN THE WAY OF INSTABILITY TO
SUPPORT THUNDERSTORMS NORTH IF INTERSTATE 94 ON SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 235 PM CDT FRI APR 25 2014
LATEST WATER VAPOR IMAGERY SHOWS A NICE DARKENING
SIGNATURE/SUBSIDENCE JUST BEHIND A SHORTWAVE SEEN CIRCULATING NEAR
38N/128W. WITH A JET STREAK STILL UPSTREAM OF THIS SHORTWAVE
TROUGH...EXPECT A CONTINUE DIGGING AND DEEPENING OF THE SYSTEM AS IT
SLIDES INTO THE SOUTHWEST SATURDAY...THEN CLOSES OFF AS IT EJECTS
INTO THE CENTRAL PLAINS/UPPER MIDWEST SUNDAY THROUGH WEDNESDAY. THE
OVERALL TREND CONTINUES TO SHOW A WIDESPREAD RAIN EVENT SUNDAY INTO
TUESDAY. TOTAL RAINFALL AMOUNTS THROUGH TUESDAY LOOK TO RANGE FROM 1
TO 1.25 INCHES FROM FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER
VALLEY...INCREASING TOWARDS THE WEST WITH 2 TO 3 INCHES OF LIQUID
FROM CROSBY TO WILLISTON AND SOUTH TO BOWMAN. THERE CONTINUES TO BE
A WEAK THREAT OF ELEVATED CONVECTION IN THE FAR SOUTHWEST AND FAR
SOUTH CENTRAL SUNDAY...BUT THIS LOOKS TOO MARGINAL FOR ANY MENTION
OF THUNDERSTORMS AT THIS TIME. THERE WILL LIKELY BE A MIX OF RAIN
AND SNOW AT NIGHT...ESPECIALLY SUNDAY NIGHT AND MONDAY NIGHT ACROSS
THE NORTHWEST AND NORTH CENTRAL. HOWEVER ANY SNOWFALL ACCUMULATIONS
WILL REMAIN NEGLIGIBLE. AS THE AFOREMENTIONED UPPER LOW AND
ASSOCIATED SURFACE LOW APPROACH LATE SATURDAY NIGHT INTO SUNDAY...A
STRONG EAST TO SOUTHEAST WIND WILL DEVELOP WITH WINDS OF 25 TO 40
MPH ACROSS CENTRAL NORTH DAKOTA. THE STRONGEST SUSTAINED WINDS ARE
FORECAST IN SOUTH CENTRAL NORTH DAKOTA AND THIS MAY NECESSITATE A
WINDY ADVISORY IN THE FUTURE.
THE UPPER LOW WILL SLOWLY MEANDER INTO THE UPPER MIDWEST TUESDAY AND
AND INTO THE GREAT LAKES WEDNESDAY/THURSDAY. HIGHS IN THE 40S WILL
DOMINATE SUNDAY THROUGH TUESDAY WITH A GRADUAL MODERATING TREND
WEDNESDAY THROUGH FRIDAY. PRECIPITATION WILL BEGIN TO WANE TUESDAY
WITH DRIER WEATHER WEDNESDAY.
BEYOND WEDNESDAY...THE UPPER AIR PATTERN IS IN QUESTION...WITH THE GFS
TRYING TO TRANSITION FROM A NORTHERLY FLOW TO A BROAD/SOMEWHAT
MOIST WESTERLY FLOW INTO THE UPCOMING WEEKEND. MEANWHILE THE ECMWF
MAINTAINS A STRONGER NORTHWEST FLOW WITH SUCCESSIVE SURGES OF COOLER
AIR AND SOME PRECIPITATION INTO NORTH DAKOTA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 107 AM CDT SAT APR 26 2014
LIGHT RAIN SHOWERS WILL MOVE INTO SOUTHWEST NORTH DAKOTA AFTER 08
UTC TONIGHT...AND MOVE NORTH-NORTHEAST THROUGH SATURDAY MORNING.
RAIN SHOWER ACTIVITY IN THE AFTERNOON IS EXPECTED TO LARGELY
REMAIN NORTH OF KISN AND KMOT. HOWEVER...A LARGE STORM SYSTEM WILL
BEGIN TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA SATURDAY
NIGHT...WITH CONDITIONS TRENDING TOWARDS MVFR/IFR IN STRATUS AND
RAIN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
413 PM EDT SAT APR 26 2014
.SYNOPSIS...
A WEAK COLD FRONT HAS SAGGED INTO CENTRAL OHIO AND INDIANA AS A
WEATHER SYSTEM SHIFTS THROUGH THE GREAT LAKES. THE FRONT WILL
STALL NEAR THE OHIO RIVER TONIGHT AS AN UPPER LEVEL RIDGE OF HIGH
PRESSURE BUILDS OVER THE FRONT AND BRINGS CONTINUED QUIET WEATHER
THROUGH SUNDAY. A LARGE...POTENT LOW PRESSURE SYSTEM WILL MOVE
SLOWLY OUT OF THE ROCKIES INTO THE HIGH PLAINS ON SUNDAY NIGHT AND
MONDAY ALLOWING THE STALLED BOUNDARY ALONG THE OHIO RIVER TO
RETURN NORTHWARD AS A WARM FRONT. WITH THIS PUSH OF SOUTHERLY
AIR...WARMTH AND MOISTURE AND WILL SPREAD NORTHWARD AND BRING
UNSETTLED WEATHER THROUGH THE FIRST HALF OF THE WORK WEEK...WITH
EPISODES OF SHOWERS AND THUNDERSTORMS ON TAP FROM LATE SUNDAY
NIGHT ALL THE WAY THROUGH WEDNESDAY. A COOLER AND STILL UNSETTLED
PATTERN WILL TAKE HOLD FOR THE END OF THE WORK WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AT 18Z...SURFACE ANALYSIS PLACES A RATHER WELL-DEFINED COLD FRONT
FROM NEAR PITTSBURGH TO COLUMBUS TO INDIANAPOLIS. A WARM AND
DEEPLY MIXED BOUNDARY LAYER EXISTS SOUTH OF THE FRONT ACROSS THE
LOCAL AREA WITH SCT CUMULUS BASED AROUND 7KFT AND TEMPS THAT HAVE
WARMED WELL INTO THE 70S...AND A DEWPOINT DROP INTO THE 40S. THE
FRONT IS ONLY WEAKLY CONVERGENT...AND MOST NWP SOLUTIONS ARE IN
GROSS ERROR WITH THE AMOUNT OF MOISTURE IN THE BOUNDARY LAYER.
HRRR HAS CAUGHT ONTO THIS WITH TIME - AND HAS SLOWLY DROPPED THE
COVERAGE OF ANY POTENTIAL SHOWERS DEVELOPING FROM THE HIGH-BASED
CUMULUS ALONG THE FRONT. GIVEN VERY DRY SUB-CLOUD LAYERS...AND A
REDUCTION IN INSTBY VIA THE MIXED BOUNDARY LAYER...WILL LIKELY NOT
MENTION ANY SHRA THROUGH THE NEXT 3-4 HOURS AND HOLD WITH SPRINKLE
MENTIONS IN THE SCIOTO VALLEY THROUGH SUNSET FROM SOME OF THE
DEEPER CUMULUS. AS THE BOUNDARY LAYER DECOUPLES TONIGHT...TEMPS
SHOULD DROP OFF GIVEN THE DRY BOUNDARY LAYER. MID LEVEL WARM
ADVECTION COUPLED WITH A VERY WEAK WAVE CRESTING THE BUILDING MID
LEVEL RIDGE WILL LIKELY CONTINUE TO ALLOW MID-CLOUD TO DEVELOP
ACROSS THE AREA OVERNIGHT. THIS...COUPLED WITH SOME INCREASING
CIRRUS...SHOULD ALLOW FOR PARTLY CLOUDY SKIES AND TEMPS IN THE
UPPER 30S TO LOWER 50S FROM NORTH TO SOUTH,
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
CURRENT GOES WATER VAPOR LOOPS AND 26.18Z RAP ANALYSIS CLEARLY
SHOW POTENT UPPER LOW DIGGING/TURNING EAST NOW THROUGH AZ. THIS
HAS INDUCED STRONG DOWNSTREAM RIDGING FROM THE LOWER MS VALLEY
NORTHWARD INTO THE DAKOTAS WHILE GREAT LAKES SYSTEM DRIVING THE
COLD FRONT MENTIONED ABOVE SLIDES INTO NEW ENGLAND. THE
PROGRESSION OF THE LATTER SYSTEM INTO NEW ENGLAND AND THE FORMER
SYSTEM OUT INTO COLORADO WILL ALLOW LARGE SCALE/AMPLIFIED RIDGING
INTO AND ACROSS THE OHIO VALLEY ON SUNDAY. THESE RISING HEIGHTS
WILL ACT TO STALL THE COLD FRONT CURRENTLY SAGGING THROUGH
OHIO...WITH THE FRONT SETTING UP SOMEWHERE NEAR/ALONG THE OHIO
RIVER. THERE IS A WEALTH OF MID/UPPER LEVEL MOISTURE STREAMING
NORTHEASTWARD THROUGH THE NATIONS MIDSECTION IN THE STRONGER SWLY
FLOW ON THE WEST SIDE OF THE RIDGE...SO FEEL TOMORROW WILL HAVE
MORE CLOUDS THAN TODAY...LIKELY SOME MID LEVEL AC AND CIRRUS AS
WARM/MOIST ADVECTION BEGINS FIRST AT THOSE LEVELS THE RIDGE
CROSSES THE AREA. UNDERNEATH...WEAK HIGH PRESSURE WILL BE NOSING
SOUTHWARD INTO EASTERN OHIO ON SUNDAY PROVIDING A DRY/EASTERLY
BREEZE WHICH WILL KEEP TEMPERATURES A LITTLE COOLER THAN SATURDAY
ESP NORTH OF THE OHIO RIVER. THERE WILL STILL BE QUITE A TEMP
GRADIENT FROM NRN KY /SOUTH OF THE FRONT/ WHERE TEMPS NEAR 80 WILL
BE POSSIBLE AGAIN...AND NORTH OF THE FRONT THE FACTOR OF EAST
WINDS...MORE CLOUDS...WILL KEEP TEMPS IN THE 60S. COULD BE A
SNEAKY BUST DAY IN TERMS OF TEMPS NOT WARMING AS MUCH AS EXPECTED
WITH THE EASTERLY FLOW QUITE STRONG THE FURTHER NORTH OF THE OHIO
RIVER ONE GOES.
FIRST WAVES OF STRONGER THETA-E ADVECTION ARRIVE /850-700MB/
SUNDAY NIGHT AND PRIMARILY IN LATTER HALF OF THIS PERIOD...AS
INITIAL PUSH OF MOISTURE TRANSPORT OCCURS AS SURFACE LOW SWINGS
OUT INTO NEBRASKA AND DEEPENS AS THE UPPER LOW REACHES MATURITY
AND BECOMES CUT OFF. DESPITE MID/UPPER LEVEL RIDGING STILL LARGELY
BEING INTACT OVER THE OHIO VALLEY...THERE IS ENOUGH THERMODYNAMIC
FORCING WITH THE WARM/MOIST ADVECTION THAT EXPECT A SCT-BKN WAVE
OF SHOWERS AND ISOLD STORMS TO EVOLVE LATER SUNDAY EVENING TO OUR
WEST AND CROSS THE AREA LATE SUNDAY NIGHT INTO MONDAY MORNING.
DON/T SEE MUCH SEVERE THREAT WITH THIS AT ALL...PER 26.12Z GFS/NAM
BUFR SOUNDINGS...INSTBY IS MARGINAL /LESS THAN 1000 J/KG/ AND
EFFECTIVE SHEAR FOR THE PARCELS ABOVE THE BOUNDARY LAYER IS RATHER
WEAK. THESE SHOULD BE ELEVATED STORMS AND MAIN IMPACTS/THREATS
WILL BE SMALL HAIL AND/OR LOCALLY HEAVY DOWNPOURS. HAVE CONTINUED
THE MENTION OF 60-75% RAIN CHANCES FOR THIS ACTIVITY...AS THERE
REMAINS SOME UNCERTAINTY AT LEAST WITH HOW STRONG THE PUSH OF
DEEPER MOISTURE IS AND THE REMAINING ANTECEDENT DRY AIRMASS OVER
THE FORECAST AREA.
ON MONDAY...THIS INITIAL WAVE OF ADVECTION-INDUCED SHOWERS/STORMS
SHOULD PUSH NORTHEAST QUICKLY THROUGH THE MORNING AND MAY VERY
WELL HAVE A LULL WITH BREAKS OF SUN IN THE AFTERNOON. HARD TO TELL
FOR CERTAIN...WITH LARGE UPPER SYSTEM WELL TO THE WEST...THE
ABSENCE OF SYNOPTIC FORCING IS RATHER EASY TO SEE. BUT MOIST FLOW
AND CONTINUED WARMING OF THE LOWER TROP SHOULD ALLOW INSTABILITY
TO BUILD AND THIS DEVELOPING WARM SECTOR MAY VERY WELL BE FILLED
WITH A NUMBER OF CLUSTERS OF SHOWERS AND ISOLATED STORMS. SO THE
AFTERNOON HOURS ON MONDAY REMAIN UP FOR GRABS...THERE MAY BE LESS
RAIN COVERAGE IN THIS TIME PERIOD THAN CURRENT FORECAST DEPICTS.
FEELING MORE CONFIDENT THAT CONFLUENT LOW LEVEL FLOW ALONG/EAST OF
MS RIVER INTO THE MID OHIO VALLEY WILL IGNITE WITH SHOWERS/STORMS
ON MONDAY EVENING AND NIGHT WHICH SHOULD INVOLVE THE LOCAL AREA AS
THE NEXT SHORTWAVE SWINGS THROUGH AND EJECTS NORTHEAST OUT OF THE
BASE OF THE LARGE CNTL CONUS TROUGH. GIVEN THE DEEP MSLP WAY TO
THE WEST...LOW LEVEL WIND FLOWS WILL HAVE SOME COMPONENT OF
SOUTHEAST OR EAST-SOUTHEAST TRAJECTORY ON MONDAY AFTN/EVE...AND
GIVEN FAST/SWLY MID/UPPER LEVEL FLOW...PRESENTS AN OPPORTUNITY FOR
ORGANIZED SEVERE STORMS ESP IN THE SOUTH WHERE BOUNDARY LAYER
INSTBY WILL HAVE THE MOST TIME TO BUILD IN WAKE OF MONDAY MORNING
ACTIVITY. HOWEVER...POINT FCST BUFR SOUNDINGS SHOW LACK OF DECENT
EML TO STEEPEN TROPOSPHERIC LAPSE RATES...AND CAPE IS THUS
TALL/SKINNY AND OVERALL INSTBY STILL LOOKING MARGINAL. BUT SHEAR
WILL BE GOOD ESP WITH ANY EASTERLY COMPONENT TO THE LOW LEVEL WIND
FIELD...SO IF ANY PROLONGED PERIOD OF HEATING DEVELOPS MONDAY
AFTERNOON THE SUBSEQUENT THREATS FOR SEVERE GO UP LATE MON
AFTN/NIGHT. RIGHT NOW THERE IS ENOUGH UNCERTAINTY NOT TO GET
CARRIED AWAY...AND ACTUALLY GIVEN THE THERMODYNAMICS/PWAT
ANOMALIES THERE IS JUST AS MUCH CONCERN FOR A BAND OF
HEAVY/EXCESSIVE RAINFALL DEPENDING ON WHERE THE CONFLUENCE SETS
UP. SO WATCHING THIS PERIOD CLOSELY. DECIDED NOT TO GET CUTE IN
THE FORECAST...AND JUST RUNNING A HIGHER CHANCE FOR SHOWERS/STORMS
FROM MONDAY THROUGH MONDAY NIGHT GIVEN OVERALL ENSEMBLE
PROBS...DEEP MOISTURE...AND ARRIVAL OF TWO WAVES OF FORCING
MENTIONED ABOVE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
LARGE SLOW MOVING UPPER LEVEL LOW OVER THE NATIONS MID SECTION TO
PROGRESS INTO THE GREAT LAKES BY THE END OF THE WEEK. WITH THE UPPER
LOW POSITIONED TO OUR WEST...SFC FRONT LOOKS TO PUSH THROUGH ON
TUESDAY. SOME MODEL SOLN DIFFERENCES EXIST REGARDING TIMING...SO
UNCERTAINTY EXISTS REGARDING INSTABILITY AND POTENTIAL FOR SEVERE
WEATHER.
AS THE LOW APPROACHES... WIND FIELDS INCREASE WITH MARGINAL INSTBY
INDICATED ON LATEST RUNS. WILL BECOME MORE FAVORABLE FOR HEAVY
RAIN...ESPECIALLY ACROSS THE SE IN THE MORNING. SEVERE WEATHER
IS A POSSIBILITY WITH THE BEST THREAT ACROSS THE SOUTH BUT THE
DEGREE OF THREAT WILL DEPEND ON THE TRACK AND TIMING OF THE
APPROACHING LOW/SFC FRONTAL PASSAGE. WILL CONTINUE LKLY POPS DURG
TUESDAY IN THE EAST EARLY AND THEN ENTERING THE WEST LATE.
MODEL SOLNS WORKING SOME DRIER AIR INTO ILN/S FA WEDNESDAY AS THE
UPPER LOW PIVOTS INTO THE GREAT LAKES. WILL LIMIT POPS TO CHANCE
CATEGORY.
A DECREASING CHANCE FOR SHOWERS WILL CONTINUE THURSDAY INTO FRIDAY
WITH THE UPPER LOW POSITIONED TO OUR NORTH. EXPECT SHOWER ACTIVITY
TO BECOME MORE DIURNALLY DRIVEN WITH THE BEST CHANCE ACROSS THE
NORTH.
MODEL DIFFERENCES INCREASE ON HOW FAST THE UPPER LOW OPENS UP NEXT
WEEKEND. WILL CONTINUE LOW POP CHANCE FOR A SHOWER WITH THE BEST
THREAT ACRS THE NORTH.
TEMP WISE...READINGS TO START OUT A LTL ABOVE NORMAL ON THE WARM
SIDE OF THE SYSTEM TUESDAY AND THEN COOL DOWN TO CLOSE TO 10 DEGREES
BELOW NORMAL THURSDAY/FRIDAY AS A COOLER AIRMASS MOVES INTO THE
REGION.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
A WEAK FRONT IS MOVING SOUTH THROUGH THE TAF SITES THIS
AFTERNOON...WITH WINDS SHIFTING GENTLY TODAY FROM THE WSW TO THE
WNW. TONIGHT...THESE WINDS WILL SHIFT MORE APPRECIABLY IN
DIRECTION...TURNING COUNTERCLOCKWISE TO NORTH AND THEN ENE BY
MORNING. WIND GUSTS THIS AFTERNOON WILL PEAK OUT IN THE 20-25 KNOT
RANGE...BUT CONDITIONS OVERNIGHT (THOUGH NOT CALM) WILL BE A
LITTLE LIGHTER.`
CHANCES OF PRECIPITATION ARE VERY LOW TODAY...THOUGH A FEW PATCHES
OF CLOUDS (HIGH-BASED CUMULUS OR MID CLOUDS) WILL STILL DRIFT
THROUGH THE AREA. CLOUDS WILL THICKEN AND LOWER SOMEWHAT DURING
THE NEXT 24 HOURS...BUT STILL REMAINING EASILY IN THE VFR RANGE.
THERE WILL BE A VERY SMALL CHANCE OF LIGHT RAIN EARLY ON SUNDAY
MORNING...PERHAPS A LITTLE MORE LIKELY FOR DAYTON OR AREAS
NORTHWEST OF THERE...BUT THIS SET OF TAFS WILL ONLY INDICATE SOME
ADDITIONAL LOWERING OF THE CLOUD DECK FROM 08Z-12Z.
OUTLOOK...MVFR TO IFR CONDITIONS WILL BE POSSIBLE AT TIMES IN RAIN
AND THUNDERSTORMS FROM SUNDAY NIGHT THROUGH TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...AR
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS NORMAN OK
1235 PM CDT SAT APR 26 2014
.DISCUSSION...
AVIATION DISCUSSION FOR THE 18Z TAFS IS BELOW.
&&
.AVIATION...
MAINLY VFR CONDITIONS ARE EXPECTED.
TSRA COVERAGE...INTENSITY...LOCATIONS...AND TIMING REMAIN
VERY UNCERTAIN. THUS...REMOVED TEMPO/PREVAILING MENTION OF
THEM. WILL AMEND IF CONFIDENCE OF TSRA AFFECTING ANY GIVEN
SITE INCREASES.
MVFR CONDITIONS WILL DEVELOP EAST OF KEND-KLAW-KSPS 06-12Z.
BRIEF IFR CONDITIONS MAY OCCUR AS WELL...BUT WERE NOT
MENTIONED DUE TO LOW CONFIDENCE OF OCCURRENCE.
NON CONVECTIVE LOW LEVEL WIND SHEAR IS POSSIBLE 01-14Z...BUT
DID NOT MENTION DUE TO LOW CONFIDENCE.
STRONG SOUTHWEST WINDS WILL DEVELOP 14-16Z. GUSTS OVER 35 KT AND
MVFR RESTRICTIONS IN BLDU ARE POSSIBLE. DID NOT MENTION BLDU DUE
TO LOW CONFIDENCE.
MBS
&&
.PREV DISCUSSION... /ISSUED 1057 AM CDT SAT APR 26 2014/
UPDATE...
AS NEW DATA CONTINUES TO FILTER IN THIS MORNING... IT APPEARS THAT
STORM CHANCES ARE LESS LIKELY TODAY AND THIS EVENING. 12Z OUN
SOUNDING SHOWS ENOUGH OF A CAPPING INVERSION TO BE AN ISSUE FOR
STORM DEVELOPMENT... ESPECIALLY WITH THE RELATIVELY LATE RETURN OF
LOW-LEVEL MOISTURE. THE HRRR AND RAP CONTINUE WITH SOME LATE
AFTERNOON DEVELOPMENT IN THE KNOX CITY-HOBART-ENID CORRIDOR LATE
THIS AFTERNOON... BUT THIS IS ALSO WITH FORECAST TEMPERATURES
CLIMBING INTO THE UPPER 90S TO TRIPLE DIGITS. IF TEMPERATURES DO
GET WARMER THAN OUR CURRENT FORECAST... THEN THERE WILL BE A
CHANCE OF ISOLATED HIGH-BASED STORMS DEVELOPING ALONG THE WESTERN
EDGE OF THE MOISTURE AXIS... BUT CURRENT THOUGHTS ARE TO LOWER
STORM CHANCES TO ISOLATED/LESS THAN 20 PERCENT FOR THIS AFTERNOON
AND LOWER POPS FOR THIS EVENING AS WELL. THE EXPECTED HIGH BASES
OF THE STORMS WILL ALSO MAKE THE SEVERE WEATHER SCENARIO /IF
STORMS FORM/ PRIMARILY A HAIL/WIND THREAT.
WILL CONTINUE TO WATCH TRENDS IN THE WEATHER THROUGH THE AFTERNOON
AND MAKE ADDITIONAL ADJUSTMENTS AS NECESSARY. .26.
PREV DISCUSSION... /ISSUED 643 AM CDT SAT APR 26 2014/
AVIATION...
26/12Z TAFS...VFR CONDITIONS EXPECTED TO PREVAIL MAJORITY OF
FORECAST PERIOD WITH DEVELOPMENT OF STRONG SOUTH-SOUTHWEST WINDS.
TSRA CHANCES WILL INCREASE TOWARD AND AFTER 00Z FROM SOUTHWEST
OKLAHOMA AND KSPS TOWARD CENTRAL OKLAHOMA TERMINALS TOWARD AND
AFTER 06Z. PRIMARILY MVFR/IFR IN TSRA WITH MVFR CIGS OUTSIDE OF
TSRA SOUTHERN OKLAHOMA LATE TONIGHT AHEAD OF DRYLINE.
PREV DISCUSSION... /ISSUED 501 AM CDT SAT APR 26 2014/
DISCUSSION...
LATEST ITERATION OF FINE-SCALE MODELS STILL POINT TO AT LEAST
ISOLATED THUNDERSTORM DEVELOPMENT ACROSS SOUTHWEST OKLAHOMA TOWARD
OR JUST AFTER 00Z. TAKING THESE INTO ACCOUNT...AND LOOKING AT 00Z
GFS/ECM AND NOW 06Z WRF... PROBABLE INITIATION AREAS AND MODE
EVOLUTION FAIRLY DIVERSE. WE DO NOT THINK THAT THE MODELS HAVE A
GOOD HANDLE ON QUALITY/DEPTH OF MOISTURE RETURN BUT ECM HAS
VERIFIED MUCH BETTER THAN THE OTHER MODELS LAST 12 TO 24
HOURS AND WILL BE FOLLOWED CLOSER FOR NOW. WITH NEW OBS-U/A THIS
MORNING HOPEFULLY THERE WILL BE BETTER CONSENSUS WITH 12Z MODELS.
WE STILL EXPECT THE GREATEST POTENTIAL FOR RELATIVELY HIGH-BASED
SUPERCELLS SW OKLAHOMA AND WRN NORTH TEXAS TOWARD AND AFTER 6 PM
WHERE COINCIDENCE OF HOTTER TEMPS AND DEEPER MOISTURE WILL
RESIDE. ADDITIONAL AND MORE WIDESPREAD DEVELOPMENT OF STORMS
POSSIBLE AHEAD OF DRYLINE/PAC-FRONT LATE EVENING AND OVERNIGHT AS
SUBSTANTIAL FORCING FINALLY APPROACHES. WITH INTENSE FORCING AND
BACKING DEEP LAYER SHEAR...WE STILL EXPECT THE EVOLUTION OF A (OR
MULTIPLE) ELEVATED CLUSTERS/BOW SEGMENTS THROUGH THE OVERNIGHT
HOURS. THERE COULD STILL BE STRONG/SEVERE STORMS EARLY SUNDAY
MORNING/DAYBREAK ACROSS CENTRAL AND EASTERN PORTIONS OF OKLAHOMA.
REDEVELOPMENT SUNDAY AFTERNOON/EVENING ARE EXPECTED TO BE
PRIMARILY EAST OF OUR CWA.
GOING TO BE WINDY TODAY...WITH CURRENT GRIDS MARGINALLY
APPROACHING WIND ADVISORY. SUNDAY WILL BE WINDIER MOST LOCATIONS
AND A WIND ADVISORY IS EXPECTED. ALSO...WE HAVE ISSUED A FIRE
WEATHER WATCH FOR MAJORITY OF WESTERN OKLAHOMA AND ADJACENT PARTS
OF NORTH TEXAS WITH DRY/WARM AND WINDY CONDITIONS BEHIND
DRYLINE/PAC-FRONT. DID NOT BRING WATCH INTO OKC METRO WITH
TRANSITION TO GREEN FUELS. WATCH WAS PRIMARILY FOCUSED ON AREAS
THAT ARE JUST ENTERING TRANSITION PHASE OF FUELS AND DROUGHT
STRICKEN LOCATIONS.
COOL WEEK WITH OCCASIONAL WINDY DAYS WITH PERSISTENT NORTHWEST
FLOW. LIGHT SHOWERS WILL BE POSSIBLE MAINLY WEST/NORTH PARTS OF
OKLAHOMA DURING THE WEEK WITH PASSAGE OF THERMAL TROUGHS THAT WILL
ROTATE AROUND LARGE U.S. UPPER CYCLONE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 87 66 81 51 / 10 50 30 10
HOBART OK 89 60 81 50 / 10 40 10 0
WICHITA FALLS TX 88 65 84 52 / 10 40 10 0
GAGE OK 90 58 77 46 / 10 20 10 10
PONCA CITY OK 88 66 81 49 / 10 50 40 10
DURANT OK 85 67 83 56 / 0 30 60 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR OKZ004>007-009>012-014>018-021>024-033>038-044.
TX...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR TXZ083>089.
&&
$$
26/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
1057 AM CDT SAT APR 26 2014
.UPDATE...
AS NEW DATA CONTINUES TO FILTER IN THIS MORNING... IT APPEARS THAT
STORM CHANCES ARE LESS LIKELY TODAY AND THIS EVENING. 12Z OUN
SOUNDING SHOWS ENOUGH OF A CAPPING INVERSION TO BE AN ISSUE FOR
STORM DEVELOPMENT... ESPECIALLY WITH THE RELATIVELY LATE RETURN OF
LOW-LEVEL MOISTURE. THE HRRR AND RAP CONTINUE WITH SOME LATE
AFTERNOON DEVELOPMENT IN THE KNOX CITY-HOBART-ENID CORRIDOR LATE
THIS AFTERNOON... BUT THIS IS ALSO WITH FORECAST TEMPERATURES
CLIMBING INTO THE UPPER 90S TO TRIPLE DIGITS. IF TEMPERATURES DO
GET WARMER THAN OUR CURRENT FORECAST... THEN THERE WILL BE A
CHANCE OF ISOLATED HIGH-BASED STORMS DEVELOPING ALONG THE WESTERN
EDGE OF THE MOISTURE AXIS... BUT CURRENT THOUGHTS ARE TO LOWER
STORM CHANCES TO ISOLATED/LESS THAN 20 PERCENT FOR THIS AFTERNOON
AND LOWER POPS FOR THIS EVENING AS WELL. THE EXPECTED HIGH BASES
OF THE STORMS WILL ALSO MAKE THE SEVERE WEATHER SCENARIO /IF
STORMS FORM/ PRIMARILY A HAIL/WIND THREAT.
WILL CONTINUE TO WATCH TRENDS IN THE WEATHER THROUGH THE AFTERNOON
AND MAKE ADDITIONAL ADJUSTMENTS AS NECESSARY. .26.
&&
.PREV DISCUSSION... /ISSUED 643 AM CDT SAT APR 26 2014/
AVIATION...
26/12Z TAFS...VFR CONDITIONS EXPECTED TO PREVAIL MAJORITY OF
FORECAST PERIOD WITH DEVELOPMENT OF STRONG SOUTH-SOUTHWEST WINDS.
TSRA CHANCES WILL INCREASE TOWARD AND AFTER 00Z FROM SOUTHWEST
OKLAHOMA AND KSPS TOWARD CENTRAL OKLAHOMA TERMINALS TOWARD AND
AFTER 06Z. PRIMARILY MVFR/IFR IN TSRA WITH MVFR CIGS OUTSIDE OF
TSRA SOUTHERN OKLAHOMA LATE TONIGHT AHEAD OF DRYLINE.
PREV DISCUSSION... /ISSUED 501 AM CDT SAT APR 26 2014/
DISCUSSION...
LATEST ITERATION OF FINE-SCALE MODELS STILL POINT TO AT LEAST
ISOLATED THUNDERSTORM DEVELOPMENT ACROSS SOUTHWEST OKLAHOMA TOWARD
OR JUST AFTER 00Z. TAKING THESE INTO ACCOUNT...AND LOOKING AT 00Z
GFS/ECM AND NOW 06Z WRF... PROBABLE INITIATION AREAS AND MODE
EVOLUTION FAIRLY DIVERSE. WE DO NOT THINK THAT THE MODELS HAVE A
GOOD HANDLE ON QUALITY/DEPTH OF MOISTURE RETURN BUT ECM HAS
VERIFIED MUCH BETTER THAN THE OTHER MODELS LAST 12 TO 24
HOURS AND WILL BE FOLLOWED CLOSER FOR NOW. WITH NEW OBS-U/A THIS
MORNING HOPEFULLY THERE WILL BE BETTER CONSENSUS WITH 12Z MODELS.
WE STILL EXPECT THE GREATEST POTENTIAL FOR RELATIVELY HIGH-BASED
SUPERCELLS SW OKLAHOMA AND WRN NORTH TEXAS TOWARD AND AFTER 6 PM
WHERE COINCIDENCE OF HOTTER TEMPS AND DEEPER MOISTURE WILL
RESIDE. ADDITIONAL AND MORE WIDESPREAD DEVELOPMENT OF STORMS
POSSIBLE AHEAD OF DRYLINE/PAC-FRONT LATE EVENING AND OVERNIGHT AS
SUBSTANTIAL FORCING FINALLY APPROACHES. WITH INTENSE FORCING AND
BACKING DEEP LAYER SHEAR...WE STILL EXPECT THE EVOLUTION OF A (OR
MULTIPLE) ELEVATED CLUSTERS/BOW SEGMENTS THROUGH THE OVERNIGHT
HOURS. THERE COULD STILL BE STRONG/SEVERE STORMS EARLY SUNDAY
MORNING/DAYBREAK ACROSS CENTRAL AND EASTERN PORTIONS OF OKLAHOMA.
REDEVELOPMENT SUNDAY AFTERNOON/EVENING ARE EXPECTED TO BE
PRIMARILY EAST OF OUR CWA.
GOING TO BE WINDY TODAY...WITH CURRENT GRIDS MARGINALLY
APPROACHING WIND ADVISORY. SUNDAY WILL BE WINDIER MOST LOCATIONS
AND A WIND ADVISORY IS EXPECTED. ALSO...WE HAVE ISSUED A FIRE
WEATHER WATCH FOR MAJORITY OF WESTERN OKLAHOMA AND ADJACENT PARTS
OF NORTH TEXAS WITH DRY/WARM AND WINDY CONDITIONS BEHIND
DRYLINE/PAC-FRONT. DID NOT BRING WATCH INTO OKC METRO WITH
TRANSITION TO GREEN FUELS. WATCH WAS PRIMARILY FOCUSED ON AREAS
THAT ARE JUST ENTERING TRANSITION PHASE OF FUELS AND DROUGHT
STRICKEN LOCATIONS.
COOL WEEK WITH OCCASIONAL WINDY DAYS WITH PERSISTENT NORTHWEST
FLOW. LIGHT SHOWERS WILL BE POSSIBLE MAINLY WEST/NORTH PARTS OF
OKLAHOMA DURING THE WEEK WITH PASSAGE OF THERMAL TROUGHS THAT WILL
ROTATE AROUND LARGE U.S. UPPER CYCLONE.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 87 66 81 51 / 10 60 30 10
HOBART OK 89 60 81 50 / 20 50 10 0
WICHITA FALLS TX 88 65 84 52 / 20 60 10 0
GAGE OK 90 58 77 46 / 10 30 10 10
PONCA CITY OK 88 66 81 49 / 10 60 40 10
DURANT OK 85 67 83 56 / 10 50 60 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR OKZ004>007-009>012-014>018-021>024-033>038-044.
TX...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR TXZ083>089.
&&
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
541 PM EDT SAT APR 26 2014
.SYNOPSIS...
AN UPPER LEVEL LOW WILL DROP THROUGH NEW ENGLAND TONIGHT. MINOR
RIDGING MOVES IN FROM THE WEST...AND SHOULD MAKE FOR DRY WEATHER
SUNDAY AND MOST OF MONDAY. BUT ANOTHER UPPER LEVEL LOW WILL
DEVELOP OVER THE CENTRAL U.S. DURING THE UPCOMING WEEK. THIS
FEATURE WILL CREATE A PROLONGED PERIOD OF UNSETTLED WEATHER FOR
PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WEAK FORCING ROLLING THRU NY STATE AND N/ERN PA WILL MAKE FOR SOME
SCT SHRA. CURRENT CROP OF SHOWERS SEEMS WIDESPREAD OVER THE NERN
THIRD OF THE AREA...BUT HARDLY ANYTHING BUT SPRINKLES ARE MAKING
IT DOWN TO THE SURFACE FROM SUCH LOFTY HEIGHTS. WINDS ARE PRETTY
STRONG AND GUSTING INTO THE M30S. BUT NOT QUITE BAD ENOUGH TO
WARRANT AN ADVY. DEWPOINTS JUST A LITTTLE HIGHER IN MD AND SOME
SFC/LLVL CONVG WILL LEAD TO COUPLE OF SHOWERS OR PERHAPS A TSRA IN
THE SE BY EVENING. BUT THE DRY AIR IS MAKING IT REALLY TOUGH.
LATEST RUC BARELY MAKES A SPRINKLE ANYWHERE IN THE CWA. WILL
THEREFORE TAKE THE POPS LOWER THAN MY EARLIER THINKING. SOME
HIGHER GUSTS OUT OF THE SHRA ARE STILL POSS. ANY SHOWERS SHOULD BE
TO THE EAST/SOUTH OF THE AREA AFTER THE TROUGH/WEAK FRONT PUSHES
OUT LATE THIS AFTN/VERY EARLY THIS EVENING.
SKIES WILL CLEAR OUT OVER MUCH OF THE AREA THIS EVENING. NERN
AREAS WILL HAVE TO DEAL WITH SOME LOW CLOUDS FOR THE FIRST HALF OF
THE NIGHT. BUT AS THE UPPER LOW MOVES A LITTLE TO THE EAST AFTER
SUNRISE...IT SHOULD GET SUNNY THERE...TOO. TEMPS WILL DIP INTO THE
M30S IN THE CENTRAL MTS TONIGHT. WINDS REMAIN UP ENOUGH -
GENERALLY ABOVE 5KTS - THAT WIDESPREAD FROST IS NOT ANTICIPATED.
WILL MENTION PATCHY FROST FOR NOW IN THE CENTRAL VALLEYS. SERN
AREAS WILL REMAIN MILDER THAN FROST ADVY WORRIES AND THE NW ISN/T
IN THE GROWING SEASON YET.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
WINDS SHOULD PICK UP A BIT FROM A MINOR LULL IN THE SUNRISE/EARLY
MORNING - MAINLY IN THE EAST CLOSER TO THE LOW PRESSURE MOVING OFF
THE COAST. OTHER THAN SOME EARLY CLOUDS IN THE NE...THE SKY
SHOULD BE MAINLY CLEAR SINCE WE ARE DOWNSTREAM OF THE RIDGE OVER
THE UPPER GREAT LAKES. TEMPS WILL RISE QUICKLY AND ATTAIN 60-65F
IN THE SRN HALF OF THE AREA AND U50S ELSEWHERE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
RIDGE OVER EASTERN U.S. WILL BRING MAINLY QUIET WEATHER SUNDAY
NIGHT INTO MONDAY. LOW LEVEL WINDS TURN SE-SW...WITH CORE OF
SOMEWHAT STRONGER FLOW FOCUSED OVER OHIO VALLEY - BEGINNING SURGE
OF INCREASINGLY MOIST AIR FURTHER NORTHWARD IN THE FORM OF A WARM
FRONT.
BROAD UPPER LOW WILL CONTINUE TO SPIN OVER UPPER MIDWEST WHILE
GRADUALLY DRIFTING EASTWARD...AS PATTERN REMAINS BLOCKED INTO
EARLY NEXT WEEK. WARM FRONT BECOMES MORE DEFINED TO OUR
SOUTH...AND WILL BECOME THE FOCUS FOR WIDESPREAD SHOWERS BY
TUE/WED/THU AS LOW CREEPS EASTWARD TO PROVIDE AREA OF SYNOPTIC
LIFT. QPF TOTALS LOOK TO BE IN THE QUARTER OF AN INCH RANGE BOTH
TUE AND WED...WITH POTENTIAL FOR HEAVIER PRECIP WED NIGHT INTO THU
AS SURFACE WAVE RIDES ALONG FRONTAL BOUNDARY. A WIDESPREAD 1-2
INCH TOTAL STILL SEEMS PLAUSIBLE OVER A 24-36HR PERIOD WED AFT
INTO THU AS PWAT VALUES PEAK /AND INSTABILITY BRINGS CHANCE FOR
TSTMS/. GIVEN THE PROJECTED SYNOPTIC PATTERN WITH CLOUDS AND SE
FLOW...EXPECT DAYTIME TEMPS TO BE COOLER THAN NORMAL WHILE
OVERNIGHT TEMPS AVG A LITTLE ABOVE LATE APRIL/EARLY MAY CLIMO.
RIDGE RE-ESTABLISHES ITSELF OVER THE WEST COAST HEADING INTO NEXT
WEEKEND...WHICH WILL KEEP BROAD TROUGH IN VICINITY AND KEEP
FEEDING COOLER AIR INTO PA LATE WEEK INTO THE WEEKEND...ALONG WITH
KEEPING A MENTION OF LIGHTER SHOWERS IN THE FORECAST /ESP IN THE
NW HALF/.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
ADJUSTED WINDS SOME.
OTHER CONCERN IS SHOWERS NEAR THE MD BORDER...GIVEN STRONG
WIND FIELDS.
EXPECT THESE TWO PROBLEMS TO EASE OFF BY SUNSET.
21Z TAFS SENT.
EARLIER DISCUSSION BELOW.
WIND STRONG AND GUSTY OUT OF THE WEST. GUSTS ARE CURRENTLY OVER
35 KTS OVER THE WRN MTS. CLOUD BASES ARE VFR BUT BKN/OVC MOST
LOCATIONS IN THE DIURNAL INSTABILITY. SOME MVFR CIGS ARE SNEAKING
TOWARD KBFD AND THE COOLING BEHIND THE WEAK FRONT/DRY LINE PASSING
THROUGH MAY HELP LOWER THE BASES/CIGS THERE TO ABOUT FL025.
SHOWERS MOVING THROUGH THE NE ARE HARDLY REACHING THE GROUND. WILL
CONTINUE TO JUST MENTION VCSH INTO THE LATE AFTN/EVEN IN THE SRN
TERMINALS. THEN CLEARING SHOULD ENSUE AT ALL BUT KBFD AND PERHAPS
KIPT. THE COLD AIR/CYCLONIC FLOW MAY KEEP A BKN CIG THERE INTO THE
NIGHT BEFORE IT BREAKS UP.
WINDS WILL DIMINISH SOMEWHAT TONIGHT. HAVE OPTED TO KEEP FOG OUT
OF THE TAFS SINCE THE AIR IS SO DRY. IF IT COULD ACTUALLY
RAIN...THAT MIGHT HAPPEN. BUT SO FAR THE FL050 PLUS BASES TO THE
CLOUDS DO NOT LEND THEMSELVES TO MOD OR HEAVY RAIN.
HIGH PRESSURE BUILDS IN SUNDAY AND MONDAY...WITH GENERALLY
UNRESTRICTED CONDITIONS.
OUTLOOK...
.SUN...VFR.
.MON...VFR.
.MON NIGHT...LOWERING CIGS AS WARM FRONT PASSES WITH MVFR/IFR AND
DEVELOPING SHRA.
.TUE-WED...MVFR/IFR WITH PERIODS OF RAIN/THUNDER.
.THUR...MAINLY VFR...SCT SHRA POSS W.
&&
.FIRE WEATHER...
ANOTHER 1 TO 2 HOURS OF STRONG WIND GUST...SOME OVER 40 MPH.
DEWPOINTS ON THE LOW SIDE.
THE COMBINATION OF WINDS AND LOW DEWPOINTS WILL CONTINUE TO DRY
THINGS OUT THROUGH SUNSET.
EARLIER DISCUSSION BELOW.
THE WINDS ARE STRONG...BUT SHOULD SLACKEN BUT NOT DROP OFF
TOTALLY TONIGHT. THE RH/S SHOULD RISE ABOVE 30PCT TONIGHT AND
BARELY TOUCH THAT NUMBER SUNDAY AFTN THANKS TO SOMEWHAT COOLER DAY
TIME TEMPS. THE WINDS WILL STAY UNDER RED FLAG CRIT FOR MOST OF
THE AREA SUNDAY...ONLY IN THE EAST WHERE PRESSURE GRADIENT IS
TIGHT ENOUGH WILL THE WINDS GUST ABOVE 15 KTS. SO...IT IS A
MARGINAL SITUATION FOR WINDS AND MIN RH/S THERE. BUT NOT CONFIDENT
ENOUGH TO POST A FIRE WX WATCH AT THIS POINT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...DANGELO/MARTIN
FIRE WEATHER...DANGELO/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
352 PM EDT SAT APR 26 2014
.SYNOPSIS...
AN UPPER LEVEL LOW WILL DROP THROUGH NEW ENGLAND TONIGHT. MINOR
RIDGING MOVES IN FROM THE WEST...AND SHOULD MAKE FOR DRY WEATHER
SUNDAY AND MOST OF MONDAY. BUT ANOTHER UPPER LEVEL LOW WILL
DEVELOP OVER THE CENTRAL U.S. DURING THE UPCOMING WEEK. THIS
FEATURE WILL CREATE A PROLONGED PERIOD OF UNSETTLED WEATHER FOR
PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WEAK FORCING ROLLING THRU NY STATE AND N/ERN PA WILL MAKE FOR SOME
SCT SHRA. CURRENT CROP OF SHOWERS SEEMS WIDESPREAD OVER THE NERN
THIRD OF THE AREA...BUT HARDLY ANYTHING BUT SPRINKLES ARE MAKING
IT DOWN TO THE SURFACE FROM SUCH LOFTY HEIGHTS. WINDS ARE PRETTY
STRONG AND GUSTING INTO THE M30S. BUT NOT QUITE BAD ENOUGH TO
WARRANT AN ADVY. DEWPOINTS JUST A LITTTLE HIGHER IN MD AND SOME
SFC/LLVL CONVG WILL LEAD TO COUPLE OF SHOWERS OR PERHAPS A TSRA IN
THE SE BY EVENING. BUT THE DRY AIR IS MAKING IT REALLY TOUGH.
LATEST RUC BARELY MAKES A SPRINKLE ANYWHERE IN THE CWA. WILL
THEREFORE TAKE THE POPS LOWER THAN MY EARLIER THINKING. SOME
HIGHER GUSTS OUT OF THE SHRA ARE STILL POSS. ANY SHOWERS SHOULD BE
TO THE EAST/SOUTH OF THE AREA AFTER THE TROUGH/WEAK FRONT PUSHES
OUT LATE THIS AFTN/VERY EARLY THIS EVENING.
SKIES WILL CLEAR OUT OVER MUCH OF THE AREA THIS EVENING. NERN
AREAS WILL HAVE TO DEAL WITH SOME LOW CLOUDS FOR THE FIRST HALF OF
THE NIGHT. BUT AS THE UPPER LOW MOVES A LITTLE TO THE EAST AFTER
SUNRISE...IT SHOULD GET SUNNY THERE...TOO. TEMPS WILL DIP INTO THE
M30S IN THE CENTRAL MTS TONIGHT. WINDS REMAIN UP ENOUGH -
GENERALLY ABOVE 5KTS - THAT WIDESPREAD FROST IS NOT ANTICIPATED.
WILL MENTION PATCHY FROST FOR NOW IN THE CENTRAL VALLEYS. SERN
AREAS WILL REMAIN MILDER THAN FROST ADVY WORRIES AND THE NW ISN/T
IN THE GROWING SEASON YET.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
WINDS SHOULD PICK UP A BIT FROM A MINOR LULL IN THE SUNRISE/EARLY
MORNING - MAINLY IN THE EAST CLOSER TO THE LOW PRESSURE MOVING OFF
THE COAST. OTHER THAN SOME EARLY CLOUDS IN THE NE...THE SKY
SHOULD BE MAINLY CLEAR SINCE WE ARE DOWNSTREAM OF THE RIDGE OVER
THE UPPER GREAT LAKES. TEMPS WILL RISE QUICKLY AND ATTAIN 60-65F
IN THE SRN HALF OF THE AREA AND U50S ELSEWHERE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
RIDGE OVER EASTERN U.S. WILL BRING MAINLY QUIET WEATHER SUNDAY
NIGHT INTO MONDAY. LOW LEVEL WINDS TURN SE-SW...WITH CORE OF
SOMEWHAT STRONGER FLOW FOCUSED OVER OHIO VALLEY - BEGINNING SURGE
OF INCREASINGLY MOIST AIR FURTHER NORTHWARD IN THE FORM OF A WARM
FRONT.
BROAD UPPER LOW WILL CONTINUE TO SPIN OVER UPPER MIDWEST WHILE
GRADUALLY DRIFTING EASTWARD...AS PATTERN REMAINS BLOCKED INTO
EARLY NEXT WEEK. WARM FRONT BECOMES MORE DEFINED TO OUR
SOUTH...AND WILL BECOME THE FOCUS FOR WIDESPREAD SHOWERS BY
TUE/WED/THU AS LOW CREEPS EASTWARD TO PROVIDE AREA OF SYNOPTIC
LIFT. QPF TOTALS LOOK TO BE IN THE QUARTER OF AN INCH RANGE BOTH
TUE AND WED...WITH POTENTIAL FOR HEAVIER PRECIP WED NIGHT INTO THU
AS SURFACE WAVE RIDES ALONG FRONTAL BOUNDARY. A WIDESPREAD 1-2
INCH TOTAL STILL SEEMS PLAUSIBLE OVER A 24-36HR PERIOD WED AFT
INTO THU AS PWAT VALUES PEAK /AND INSTABILITY BRINGS CHANCE FOR
TSTMS/. GIVEN THE PROJECTED SYNOPTIC PATTERN WITH CLOUDS AND SE
FLOW...EXPECT DAYTIME TEMPS TO BE COOLER THAN NORMAL WHILE
OVERNIGHT TEMPS AVG A LITTLE ABOVE LATE APRIL/EARLY MAY CLIMO.
RIDGE RE-ESTABLISHES ITSELF OVER THE WEST COAST HEADING INTO NEXT
WEEKEND...WHICH WILL KEEP BROAD TROUGH IN VICINITY AND KEEP
FEEDING COOLER AIR INTO PA LATE WEEK INTO THE WEEKEND...ALONG WITH
KEEPING A MENTION OF LIGHTER SHOWERS IN THE FORECAST /ESP IN THE
NW HALF/.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
WIND STRONG AND GUSTY OUT OF THE WEST. GUSTS ARE CURRENTLY OVER
35 KTS OVER THE WRN MTS. CLOUD BASES ARE VFR BUT BKN/OVC MOST
LOCATIONS IN THE DIURNAL INSTABILITY. SOME MVFR CIGS ARE SNEAKING
TOWARD KBFD AND THE COOLING BEHIND THE WEAK FRONT/DRY LINE PASSING
THROUGH MAY HELP LOWER THE BASES/CIGS THERE TO ABOUT FL025.
SHOWERS MOVING THROUGH THE NE ARE HARDLY REACHING THE GROUND. WILL
CONTINUE TO JUST MENTION VCSH INTO THE LATE AFTN/EVEN IN THE SRN
TERMINALS. THEN CLEARING SHOULD ENSUE AT ALL BUT KBFD AND PERHAPS
KIPT. THE COLD AIR/CYCLONIC FLOW MAY KEEP A BKN CIG THERE INTO THE
NIGHT BEFORE IT BREAKS UP.
WINDS WILL DIMINISH SOMEWHAT TONIGHT. HAVE OPTED TO KEEP FOG OUT
OF THE TAFS SINCE THE AIR IS SO DRY. IF IT COULD ACTUALLY
RAIN...THAT MIGHT HAPPEN. BUT SO FAR THE FL050 PLUS BASES TO THE
CLOUDS DO NOT LEND THEMSELVES TO MOD OR HEAVY RAIN.
HIGH PRESSURE BUILDS IN SUNDAY AND MONDAY...WITH GENERALLY
UNRESTRICTED CONDITIONS.
OUTLOOK...
.SUN...VFR.
.MON...VFR.
.MON NIGHT...LOWERING CIGS AS WARM FRONT PASSES WITH MVFR/IFR AND
DEVELOPING SHRA.
.TUE-WED...MVFR/IFR WITH PERIODS OF RAIN/THUNDER.
.THUR...MAINLY VFR...SCT SHRA POSS W.
&&
.FIRE WEATHER...
SHOWERS TODAY ARE NOT HELPING RAISE ANY MOISTURE LEVELS. THE WINDS
ARE STRONG...BUT SHOULD SLACKEN BUT NOT DROP OFF TOTALLY TONIGHT.
THE RH/S SHOULD RISE ABOVE 30PCT TONIGHT AND BARELY TOUCH THAT
NUMBER SUNDAY AFTN THANKS TO SOMEWHAT COOLER DAY TIME TEMPS. THE
WINDS WILL STAY UNDER RED FLAG CRIT FOR MOST OF THE AREA
SUNDAY...ONLY IN THE EAST WHERE PRESSURE GRADIENT IS TIGHT ENOUGH
WILL THE WINDS GUST ABOVE 15 KTS. SO...IT IS A MARGINAL SITUATION
FOR WINDS AND MIN RH/S THERE. BUT NOT CONFIDENT ENOUGH TO POST A
FIRE WX WATCH AT THIS POINT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...DANGELO
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
238 PM EDT SAT APR 26 2014
.SYNOPSIS...
AN UPPER LEVEL LOW WILL DROP THROUGH NEW ENGLAND TONIGHT. MINOR
RIDGING MOVES IN FROM THE WEST...AND SHOULD MAKE FOR DRY WEATHER
SUNDAY AND MOST OF MONDAY. BUT ANOTHER UPPER LEVEL LOW WILL
DEVELOP OVER THE CENTRAL U.S. DURING THE UPCOMING WEEK. THIS
FEATURE WILL CREATE A PROLONGED PERIOD OF UNSETTLED WEATHER FOR
PENNSYLVANIA.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK FORCING ROLLING THRU NY STATE AND N/ERN PA WILL MAKE FOR SOME
SCT SHRA. CURRENT CROP OF SHOWERS SEEMS WIDESPREAD OVER THE NERN
THIRD OF THE AREA...BUT HARDLY ANYTHING BUT SPRINKLES ARE MAKING
IT DOWN TO THE SURFACE FROM SUCH LOFTY HEIGHTS. WINDS ARE PRETTY
STRONG AND GUSTING INTO THE M30S. BUT NOT QUITE BAD ENOUGH TO
WARRANT AN ADVY. DEWPOINTS JUST A LITTTLE HIGHER IN MD AND SOME
SFC/LLVL CONVG WILL LEAD TO COUPLE OF SHOWERS OR PERHAPS A TSRA IN
THE SE BY EVENING. BUT THE DRY AIR IS MAKING IT REALLY TOUGH.
LATEST RUC BARELY MAKES A SPRINKLE ANYWHERE IN THE CWA. WILL
THEREFORE TAKE THE POPS LOWER THAN MY EARLIER THINKING. SOME
HIGHER GUSTS OUT OF THE SHRA ARE STILL POSS. ANY SHOWERS SHOULD BE
TO THE EAST/SOUTH OF THE AREA AFTER THE TROUGH/WEAK FRONT PUSHES
OUT LATE THIS AFTN/VERY EARLY THIS EVENING.
SKIES WILL CLEAR OUT OVER MUCH OF THE AREA THIS EVENING. NERN
AREAS WILL HAVE TO DEAL WITH SOME LOW CLOUDS FOR THE FIRST HALF OF
THE NIGHT. BUT AS THE UPPER LOW MOVES A LITTLE TO THE EAST AFTER
SUNRISE...IT SHOULD GET SUNNY THERE...TOO. TEMPS WILL DIP INTO THE
M30S IN THE CENTRAL MTS TONIGHT. WINDS REMAIN UP ENOUGH -
GENERALLY ABOVE 5KTS - THAT WIDESPREAD FROST IS NOT ANTICIPATED.
WILL MENTION PATCHY FROST FOR NOW IN THE CENTRAL VALLEYS. SERN
AREAS WILL REMAIN MILDER THAN FROST ADVY WORRIES AND THE NW ISN/T
IN THE GROWING SEASON YET.
&&
.SHORT TERM /SUNDAY/...
WINDS SHOULD PICK UP A BIT FROM A MINOR LULL IN THE SUNRISE/EARLY
MORNING - MAINLY IN THE EAST CLOSER TO THE LOW PRESSURE MOVING OFF
THE COAST. OTHER THAN SOME EARLY CLOUDS IN THE NE...THE SKY
SHOULD BE MAINLY CLEAR SINCE WE ARE DOWNSTREAM OF THE RIDGE OVER
THE UPPER GREAT LAKES. TEMPS WILL RISE QUICKLY AND ATTAIN 60-65F
IN THE SRN HALF OF THE AREA AND U50S ELSEWHERE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE 26/00Z MEDIUM RANGE MODEL AND ENSEMBLE GUIDANCE CONTINUES TO
ADVERTISE A LARGE SCALE PATTERN SHIFT TO A BLOCKING REGIME ACROSS
THE CONUS FOR DAYS 4-7/MON-FRI...WITH REX BLOCK OVER CENTRAL NOAM
AND UPPER RIDGES ALONG THE WEST/EAST COASTS. AFTER AN INITIALLY
DRY PERIOD ON SUNDAY INTO EARLY MONDAY ASSOCIATED WITH A NARROW
SFC HIGH PINCHED IN-BETWEEN SFC LOWS MIGRATING OVER THE PLAINS/NRN
ATLC...THE EVOLVING PATTERN FAVORS INCREASINGLY WET AND RELATIVELY
COOL CONDITIONS OVER CENTRAL PA. THEREFORE HAVE ADJUSTED POPS
UPWARD IN THE LONG TERM...WITH INCREASING CONFIDENCE IN
SIGNIFICANT/BENEFICIAL RAINFALL FOCUSED IN THE TUE-THR TIMEFRAME.
A WIDESPREAD 1-2 INCHES SEEMS PLAUSIBLE AT THIS TIME OVER A
48-72HR PERIOD CENTERED AROUND THE MIDDLE OF NEXT WEEK. GIVEN THE
PROJECTED SYNOPTIC PATTERN WITH CLOUDS AND SE FLOW...EXPECT
DAYTIME TEMPS TO BE COOLER THAN NORMAL WHILE OVERNIGHT TEMPS AVG A
LITTLE ABOVE LATE APRIL/EARLY MAY CLIMO.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
WIND STRONG AND GUSTY OUT OF THE WEST. GUSTS ARE CURRENTLY OVER
35 KTS OVER THE WRN MTS. CLOUD BASES ARE VFR BUT BKN/OVC MOST
LOCATIONS IN THE DIURNAL INSTABILITY. SOME MVFR CIGS ARE SNEAKING
TOWARD KBFD AND THE COOLING BEHIND THE WEAK FRONT/DRY LINE PASSING
THROUGH MAY HELP LOWER THE BASES/CIGS THERE TO ABOUT FL025.
SHOWERS MOVING THROUGH THE NE ARE HARDLY REACHING THE GROUND. WILL
CONTINUE TO JUST MENTION VCSH INTO THE LATE AFTN/EVEN IN THE SRN
TERMINALS. THEN CLEARING SHOULD ENSUE AT ALL BUT KBFD AND PERHAPS
KIPT. THE COLD AIR/CYCLONIC FLOW MAY KEEP A BKN CIG THERE INTO THE
NIGHT BEFORE IT BREAKS UP.
WINDS WILL DIMINISH SOMEWHAT TONIGHT. HAVE OPTED TO KEEP FOG OUT
OF THE TAFS SINCE THE AIR IS SO DRY. IF IT COULD ACTUALLY
RAIN...THAT MIGHT HAPPEN. BUT SO FAR THE FL050 PLUS BASES TO THE
CLOUDS DO NOT LEND THEMSELVES TO MOD OR HEAVY RAIN.
HIGH PRESSURE BUILDS IN SUNDAY AND MONDAY...WITH GENERALLY
UNRESTRICTED CONDITIONS.
OUTLOOK...
.SUN...VFR.
.MON...VFR.
.MON NIGHT...LOWERING CIGS AS WARM FRONT PASSES WITH MVFR/IFR AND
DEVELOPING SHRA.
.TUE-WED...MVFR/IFR WITH PERIODS OF RAIN/THUNDER.
.THUR...MAINLY VFR...SCT SHRA POSS W.
&&
.FIRE WEATHER...
SHOWERS TODAY ARE NOT HELPING RAISE ANY MOISTURE LEVELS. THE WINDS
ARE STRONG...BUT SHOULD SLACKEN BUT NOT DROP OFF TOTALLY TONIGHT.
THE RH/S SHOULD RISE ABOVE 30PCT TONIGHT AND BARELY TOUCH THAT
NUMBER SUNDAY AFTN THANKS TO SOMEWHAT COOLER DAY TIME TEMPS. THE
WINDS WILL STAY UNDER RED FLAG CRIT FOR MOST OF THE AREA
SUNDAY...ONLY IN THE EAST WHERE PRESSURE GRADIENT IS TIGHT ENOUGH
WILL THE WINDS GUST ABOVE 15 KTS. SO...IT IS A MARGINAL SITUATION
FOR WINDS AND MIN RH/S THERE. BUT NOT CONFIDENT ENOUGH TO POST A
FIRE WX WATCH AT THIS POINT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...DANGELO
FIRE WEATHER...DANGELO
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1016 PM EDT SUN APR 27 2014
.SYNOPSIS...
A WET AND STORMY PATTERN WILL SET UP ACROSS THE AREA MONDAY THROUGH
WEDNESDAY...FOLLOWED BY COOL AND DRIER HIGH PRESSURE BY THE END OF
THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 1010 PM EDT SUNDAY...BLENDED POPS ARE WORKING WELL AS
SCATTERED LIGHT SHOWERS HAVE DEVELOPED OVER THE WESTERN ZONES...AND
A FEW STRONGER STORMS HAVE DEVELOPED NOT TOO FAR UPSTREAM OF THE
FORECAST AREA. POPS AND SKY COVER LOOK GOOD.
AT 735 PM EDT SUNDAY...BLENDED A POP DERIVED FROM LOCAL CONVECTIVE
ALLOWING MODELS AND THE OFFICIAL FORECAST TO GO WITH A SMALL AREA OF
HIGH CHANCE AND LIKELY POPS FROM THE UPSTATE INTO THE SRN AND
CENTRAL NC MTNS. THE 18 UTC NAM HAD A LITTLE BETTER ELEVATED CAPE
ACROSS THIS AREA AND THE HRRR AND WRF-ARW ARE INCREASES CONVECTIVE
COVERAGE OVER THIS AREA LATER TONIGHT. OTHERWISE...INCREASED SKY
COVER AND MADE SOME MINOR TWEAKS TO THE REST OF THE GRIDS.
AT 430 PM EDT SUNDAY...ADJUSTED SKY GRIDS TO ACCOUNT FOR ENCROACHING
HIGH CLOUDS AS WELL AS A CU DECK THAT IS DEVELOPING ACROSS NE
GA...THE SW NC MTNS AND THE WRN UPSTATE. SOME OF THE MESOSCALE
MODELS BRING ELEVATED CONVECTION ACROSS THE FORECAST AREA OVERNIGHT
AS THE LEADING EDGE OF THE ELEVATED MIXED LAYER WORKS IN FROM THE
WEST. I DON/T SEE MUCH MUCAPE ON THE 18 UTC NAM...SO THINK MOST OF
THE ACTIVITY WILL BE WEAK. I WON/T ADJUST THE OVERNIGHT GRIDS JUST
YET..BUT I NEED TO RAMP UP POPS WITH SUBSEQUENT UPDATES.
AT 200 PM EDT SUNDAY...A NEGATIVELY TILTED UPPER TROUGH WILL SLOWLY
PROGRESS ACROSS THE SOUTHERN APPALACHIANS AND GREAT LAKES TONIGHT...
WHILE A CLOSED UPPER LOW MOVES NE ACROSS THE GREAT PLAINS. THE RIDGE
AXIS MOVES EAST OF THE MOUNTAINS ON MONDAY...WHILE THE UPPER LOW
DRIFTS BACK SOUTH OVER THE PLAINS.
ISENTROPIC UPGLIDE WILL SPREAD ACROSS THE UPPER SAVANNAH RIVER
VALLEY AND SOUTHERN APPALACHIANS LATE THIS AFTERNOON AND THIS
EVENING. INSTABILITY SHOULD BECOME SUFFICIENT FOR CONVECTION TO FORM
BEFORE EVENING...HOWEVER NEITHER SHEAR NOR INSTABILITY APPEAR
IMPRESSIVE. A BACK DOOR COLD FRONT WILL SETTLE SOUTH ACROSS WESTERN
NC TONIGHT...REACHING THE SC BORDER EAST OF THE MOUNTAINS BY
DAYBREAK.
THE BOUNDARY WILL BECOME A FOCUS FOR CONVECTIVE ACTIVITY ON
MONDAY...WHEN BETTER SHEAR AND INSTABILITY WILL BE PRESENT. SPC HAS
OUR ENTIRE AREA IN A SLIGHT RISK FOR SEVERE WEATHER ON DAY
TWO...MENTIONING AN ENVIRONMENT FAVORABLE FOR SUPERCELLS. THE AREA
NORTH OF INTERSTATE 40 MAY REMAIN UNFAVORABLE FOR CONVECTION DURING
THE DAYLIGHT HOURS ON MONDAY...AS COOL NE FLOW PREVAILS BEHIND THE
FRONT...AND A CAP REMAINS AT AROUND 875 MB. WITH THE BEST GULF
INFLOW STILL WELL TO THE WEST...EXCESSIVE RAINFALL IS NOT
EXPECTED...HOWEVER INDIVIDUAL STORMS MAY PUT DOWN LOCALLY HEAVY
RAINFALL.
MINIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL UNDER INCREASING
CLOUDS COVER AND THE UPPER RIDGE. HIGH TEMPERATURES ON MONDAY WILL
RUN SLIGHTLY ABOVE NORMAL...AS CLOUD COVERAGE OFFSETS THE INFLUENCE
OF THE UPPER RIDGE.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 235 PM SUNDAY...NOTHING IN THE NEW GUIDANCE TO CHANGE EARLIER
THINKING THAT WE ARE ON A COLLISION COURSE WITH A VERY WET AND VERY
STORMY PATTERN DURING THE LATE MONDAY TO WEDNESDAY TIME FRAME.
IMPORTANT DETAILS SUCH AS THE TIMING OF ENHANCED SEVERE THUNDERSTORM
THREATS...AND STORM TOTAL RAINFALL...STILL REMAIN IN DOUBT.
ONE INTERESTING TREND OR POINT OF CONCERN IS BROUGHT TO LIGHT IN THE
LATEST NAM MONDAY NIGHT AND EARLY TUESDAY MORNING. A WEDGE BOUNDARY
OF SORTS IS INDICATED EVEN FARTHER SOUTH THAN PREVIOUS RUNS...DOWN
CLOSER TO THE SC/NC BORDER. THE AIR MASS TO THE SOUTH OF THE
BOUNDARY MIGHT BE FAIRLY RICH WITH BUOYANCY. THE SREF HAS A VERY
HIGH PROBABILITY OF CAPE GREATER THAN 1000 J/KG LATE IN THE
DAY...AND EVEN THE GENERALLY MORE CONSERVATIVE GFS HAS CAPE IN THE
1000 - 1500 J/KG RANGE. SHEAR AND SRH WILL INCREASE STEADILY THROUGH
THE EVENING HOURS IN THE PRESENCE OF ADEQUATE BUOYANCY...THUS OUR
CHANCES FOR ORGANIZED SEVERE THUNDERSTORMS WILL ALSO INCREASE. AGREE
WITH THE EXPANSION OF THE DAY2 SLIGHT RISK FURTHER EAST IN THE NEW
OUTLOOK. IF THE WEST TO EAST ORIENTED BOUNDARY REMAINS IN THE
AREA...THIS COULD PROVIDE THE FOCUS FOR SEVERE STORMS AND TORNADIC
ACTIVITY SOMEWHERE IN THE CAROLINAS WELL INTO THE OVERNIGHT HOURS.
THERE IS ALSO THE CONCERN THAT SUPERCELLULAR CONVECTION MOVING IN
FROM GEORGIA DURING THE EVENING WILL GET A SHOT OF INCREASED SHEAR
AS IT INTERACTS WITH A BOUNDARY. AT THE SAME TIME...THE FRONTAL ZONE
OF HEAVIER RAIN WILL MOVE INTO THE MOUNTAINS.
CONFIDENCE IN THE TIMING OF ANY MESOSCALE CONVECTIVE SYSTEMS GOES
DOWN AFTER LATE MONDAY NIGHT...BUT WE WILL RETAIN A FAVORABLE
COMBINATION OF SHEAR AND INSTABILITY TO KEEP A THREAT OF SEVERE
STORMS THROUGH TUESDAY ACROSS MOST OF THE FCST AREA...WITH PERHAPS
THE EXCEPTION OF THE WRN NC MTNS...AND INTO WEDNESDAY EAST OF THE
MOUNTAINS. ONE MIGHT EXPECT A BIT OF A LULL OR RECHARGE PERIOD
TUESDAY MORNING...BEFORE MORE ORGANIZED SEVERE WEATHER AFFECTS THE
REGION TUESDAY AFTERNOON AND EVENING WITH DIURNAL ENHANCEMENT. CAPE
PROFILES SUGGEST THAT WE MIGHT HAVE A BIT LESS OF A CHANCE OF
SUPERCELLS AND THE LIKE...BECAUSE OF CONVECTIVE DEBRIS/
OVERTURNING...BUT STILL ENOUGH OF A TORNADO THREAT FOR CONTINUED
CONCERN BECAUSE OF THE SHEAR. ADDITIONAL DETAILS WILL HOPEFULLY COME
MORE INTO FOCUS WITH SUBSEQUENT FCST PACKAGES.
AT ANY RATE...PRECIP CHANCES RAMP UP STEADILY FROM THE WEST INTO THE
LIKELY TO CATEGORICAL RANGE MONDAY NIGHT AND INTO TUESDAY AND
TUESDAY NIGHT. THE LATEST QPF GUIDANCE FROM WPC IS VERY TROUBLESOME.
ON THE ONE HAND...ANOMALY GUIDANCE DOES NOT SHOW ANYTHING OVERLY
ALARMING WITH REGARD TO PRECIPITABLE WATER...BUT ON THE OTHER HAND
THE SLOW MOVING NATURE OF THE COLD FRONT WILL PERMIT WAVES OF
MODERATE TO HEAVY RAIN STARTING EARLY TUESDAY MORNING...AND
CONTINUING INTO WEDNESDAY. UNLESS THERE IS SOME CHANGE IN
THINKING... THE NEED FOR A FLOOD WATCH IS NEARLY A FOREGONE
CONCLUSION...BUT THE MAIN THREAT OF FLOODING DOES NOT RAMP UP UNTIL
DURING THE DAY ON TUESDAY BASED ON THE QPF BREAKDOWN. SINCE THIS IS
THE 4TH FCST PERIOD AND WE HAVE SOME TIME TO GAIN MORE CONFIDENCE...
WILL HOLD OFF ON A FLOOD WATCH FOR ONE MORE FCST CYCLE.
MODEL GUIDANCE SHOWS THE FRONT CROSSING THE FCST AREA WEDNESDAY
EVENING AND THAT SHOULD BRING AN END TO MOST OF THE PRECIP...WITH
SOME LINGERING SHOWERS POSSIBLE ON THE TN BORDER OVER THE NRN MTNS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1 PM SUNDAY...EXPANSIVE UPPER TROUGH WILL REMAIN OVER THE ERN
CONUS THROUGH THE MEDIUM RANGE...WITH THE FLOW EVENTUALLY FLATTENING
BY THE END OF NEXT WEEKEND. FAIRLY UNSETTLED CONDITIONS WILL CONTINUE
ACRS THE SOUTHEAST REGION UNTIL THAT TIME. FRONTAL BOUNDARY LAYS OUT
JUST OFFSHORE FRIDAY.
GFS/EC/GEM AGREE ON A SHORTWAVE ROUNDING THE LARGER SCALE TROUGH AND
BRINGING A WAVE OUT OF THE GULF OF MEXICO ALONG THE FRONT. THEY
DISAGREE HOWEVER ON THE TIMING OF THIS EVENT. 12Z GFS/GEM DEVELOP
ONLY A WEAK WAVE FRIDAY...AND HAVE A LOW IMPACT ON OUR CWFA WITH VERY
LITTLE QPF. ORIENTATION OF THE FRONT ON THE 00Z EC LEADS IT TO
DEVELOP A STRONGER WAVE AND BRING ANOTHER ROUND OF PRECIP TO THE
PIEDMONT FRIDAY NIGHT AND SATURDAY. GFS CONCURRENTLY DEVELOPS SHOWERS
IN THE MTNS AS IT BRINGS THE WAVE ACRS EARLY SATURDAY...WITH
ADDITIONAL NW FLOW PRECIP CONTINUING INTO EARLY SUNDAY. THIS IS A
PLAUSIBLE SCENARIO THOUGH IT IS THE ONLY MODEL SHOWING IT. QPF FROM
THIS ACTIVITY IS NOTABLE BUT NOT HIGH ENOUGH FOR CONCERN...SO IT WILL
BE MINIMALLY REFLECTED IN THE FCST. IN FACT...NCEP/CMC ENSEMBLES GIVE
LITTLE SUPPORT TO A WETTER EC-LIKE SOLUTION SO POPS WILL BE KEPT ON
THE LOW SIDE FOR THE POTENTIAL FRONTAL WAVE PRECIP...ALONG WITH QPF.
AFTER ABV NORMAL TEMPS THU...TEMPS RETURN TO AROUND NORMAL FRI INTO
SAT WITH CLOUD COVER. LOWS SUNDAY MRNG SHOULD BE A COUPLE CATEGORIES
BELOW NORMAL BUT TEMPS REBOUND SUNDAY UNDER CLEARER SKIES.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
AT KCLT...PUSHED THE TIMING OF THE VFR AND THEN MVFR CIGS BACK 4 TO
6 HOURS. A WEAK BACK DOOR FRONT IS STILL EXPECTED TO TURN THE WINDS
LIGHT OUT OF THE EAST OR ENE LATE TONIGHT AND THROUGH MUCH OF THE
MORNING HOURS ON MON. AND IT IS POSSIBLE THAT MVFR CIGS WILL
ACCOMPANY THE BNDRY...SO I DIDN/T REMOVE THEM...THOUGH I JUST DON/T
SEE A LOT TO FORCE LOWER CLOUDS. SHRA/TSTMS ARE EXPECTED TO FIRE UP
NEAR THE WEAK SFC FRONT MONDAY AFTN...AND THE PROB30 PERIOD OF THE
TAF HAS BEEN PUSHED BACK TO 16-20 UTC TO ACCOUNT FOR THIS.
ELSEWHERE...ALSO PUSHED BACK THE TIMING OF LOWERING CIGS AT THE
OTHER TAF SITES. AND AT KAVL PUSHED THE TIMING WAY BACK AND DIDN/T
GO AS LOW WITH THE CIGS. A FEW SHOWERS ARE POSSIBLE LATER THIS
EVENING AND VCSH HAS BEEN ADDED TO A FEW SITES TO ACCOUNT FOR THIS.
SHRA/TSTMS ARE EXPECTED TO DEVELOP OVER THE REGION MON AFTN AND
EVENING. PUSHED THE PROB30 GROUPS BACK INTO THE LATE AFTN AND EARLY
EVENING TO ACCOUNT FOR THIS. THE KHKY AIRFIELD IS EXPECTED TO REMAIN
NORTH OF THE WEAK FRONT UNTIL LATE IN THE DAY AND ONLY ADDED PROBS
FOR SHOWERS THERE.
OUTLOOK...INCREASING MOISTURE WILL BRING PERIODIC CIG AND VSBY
RESTRICTIONS IN SHRA/TSRA...AND MORNING FOG. UNSETTLED WEATHER WILL
CONTINUE UNTIL A COLD FRONT PASSAGE EARLY THURSDAY.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-02Z
KCLT HIGH 100% HIGH 96% HIGH 97% HIGH 91%
KGSP HIGH 100% HIGH 97% HIGH 97% HIGH 100%
KAVL HIGH 100% HIGH 90% HIGH 100% HIGH 91%
KHKY HIGH 100% HIGH 95% HIGH 83% HIGH 80%
KGMU HIGH 100% HIGH 97% HIGH 97% HIGH 100%
KAND HIGH 100% HIGH 92% HIGH 97% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...JAT/MCAVOY
SHORT TERM...PM
LONG TERM...WIMBERLEY
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
747 PM EDT SUN APR 27 2014
.SYNOPSIS...
A WET AND STORMY PATTERN WILL SET UP ACROSS THE AREA MONDAY THROUGH
WEDNESDAY...FOLLOWED BY COOL AND DRIER HIGH PRESSURE BY THE END OF
THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AT 735 PM EDT SUNDAY...BLENDED A POP DERIVED FROM LOCAL CONVECTIVE
ALLOWING MODELS AND THE OFFICIAL FORECAST TO GO WITH A SMALL AREA OF
HIGH CHANCE AND LIKELY POPS FROM THE UPSTATE INTO THE SRN AND
CENTRAL NC MTNS. THE 18 UTC NAM HAD A LITTLE BETTER ELEVATED CAPE
ACROSS THIS AREA AND THE HRRR AND WRF-ARW ARE INCREASES CONVECTIVE
COVERAGE OVER THIS AREA LATER TONIGHT. OTHERWISE...INCREASED SKY
COVER AND MADE SOME MINOR TWEAKS TO THE REST OF THE GRIDS.
AT 430 PM EDT SUNDAY...ADJUSTED SKY GRIDS TO ACCOUNT FOR ENCROACHING
HIGH CLOUDS AS WELL AS A CU DECK THAT IS DEVELOPING ACROSS NE
GA...THE SW NC MTNS AND THE WRN UPSTATE. SOME OF THE MESOSCALE
MODELS BRING ELEVATED CONVECTION ACROSS THE FORECAST AREA OVERNIGHT
AS THE LEADING EDGE OF THE ELEVATED MIXED LAYER WORKS IN FROM THE
WEST. I DON/T SEE MUCH MUCAPE ON THE 18 UTC NAM...SO THINK MOST OF
THE ACTIVITY WILL BE WEAK. I WON/T ADJUST THE OVERNIGHT GRIDS JUST
YET..BUT I NEED TO RAMP UP POPS WITH SUBSEQUENT UPDATES.
AT 200 PM EDT SUNDAY...A NEGATIVELY TILTED UPPER TROUGH WILL SLOWLY
PROGRESS ACROSS THE SOUTHERN APPALACHIANS AND GREAT LAKES TONIGHT...
WHILE A CLOSED UPPER LOW MOVES NE ACROSS THE GREAT PLAINS. THE RIDGE
AXIS MOVES EAST OF THE MOUNTAINS ON MONDAY...WHILE THE UPPER LOW
DRIFTS BACK SOUTH OVER THE PLAINS.
ISENTROPIC UPGLIDE WILL SPREAD ACROSS THE UPPER SAVANNAH RIVER
VALLEY AND SOUTHERN APPALACHIANS LATE THIS AFTERNOON AND THIS
EVENING. INSTABILITY SHOULD BECOME SUFFICIENT FOR CONVECTION TO FORM
BEFORE EVENING...HOWEVER NEITHER SHEAR NOR INSTABILITY APPEAR
IMPRESSIVE. A BACK DOOR COLD FRONT WILL SETTLE SOUTH ACROSS WESTERN
NC TONIGHT...REACHING THE SC BORDER EAST OF THE MOUNTAINS BY
DAYBREAK.
THE BOUNDARY WILL BECOME A FOCUS FOR CONVECTIVE ACTIVITY ON
MONDAY...WHEN BETTER SHEAR AND INSTABILITY WILL BE PRESENT. SPC HAS
OUR ENTIRE AREA IN A SLIGHT RISK FOR SEVERE WEATHER ON DAY
TWO...MENTIONING AN ENVIRONMENT FAVORABLE FOR SUPERCELLS. THE AREA
NORTH OF INTERSTATE 40 MAY REMAIN UNFAVORABLE FOR CONVECTION DURING
THE DAYLIGHT HOURS ON MONDAY...AS COOL NE FLOW PREVAILS BEHIND THE
FRONT...AND A CAP REMAINS AT AROUND 875 MB. WITH THE BEST GULF
INFLOW STILL WELL TO THE WEST...EXCESSIVE RAINFALL IS NOT
EXPECTED...HOWEVER INDIVIDUAL STORMS MAY PUT DOWN LOCALLY HEAVY
RAINFALL.
MINIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL UNDER INCREASING
CLOUDS COVER AND THE UPPER RIDGE. HIGH TEMPERATURES ON MONDAY WILL
RUN SLIGHTLY ABOVE NORMAL...AS CLOUD COVERAGE OFFSETS THE INFLUENCE
OF THE UPPER RIDGE.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 235 PM SUNDAY...NOTHING IN THE NEW GUIDANCE TO CHANGE EARLIER
THINKING THAT WE ARE ON A COLLISION COURSE WITH A VERY WET AND VERY
STORMY PATTERN DURING THE LATE MONDAY TO WEDNESDAY TIME FRAME.
IMPORTANT DETAILS SUCH AS THE TIMING OF ENHANCED SEVERE THUNDERSTORM
THREATS...AND STORM TOTAL RAINFALL...STILL REMAIN IN DOUBT.
ONE INTERESTING TREND OR POINT OF CONCERN IS BROUGHT TO LIGHT IN THE
LATEST NAM MONDAY NIGHT AND EARLY TUESDAY MORNING. A WEDGE BOUNDARY
OF SORTS IS INDICATED EVEN FARTHER SOUTH THAN PREVIOUS RUNS...DOWN
CLOSER TO THE SC/NC BORDER. THE AIR MASS TO THE SOUTH OF THE
BOUNDARY MIGHT BE FAIRLY RICH WITH BUOYANCY. THE SREF HAS A VERY
HIGH PROBABILITY OF CAPE GREATER THAN 1000 J/KG LATE IN THE
DAY...AND EVEN THE GENERALLY MORE CONSERVATIVE GFS HAS CAPE IN THE
1000 - 1500 J/KG RANGE. SHEAR AND SRH WILL INCREASE STEADILY THROUGH
THE EVENING HOURS IN THE PRESENCE OF ADEQUATE BUOYANCY...THUS OUR
CHANCES FOR ORGANIZED SEVERE THUNDERSTORMS WILL ALSO INCREASE. AGREE
WITH THE EXPANSION OF THE DAY2 SLIGHT RISK FURTHER EAST IN THE NEW
OUTLOOK. IF THE WEST TO EAST ORIENTED BOUNDARY REMAINS IN THE
AREA...THIS COULD PROVIDE THE FOCUS FOR SEVERE STORMS AND TORNADIC
ACTIVITY SOMEWHERE IN THE CAROLINAS WELL INTO THE OVERNIGHT HOURS.
THERE IS ALSO THE CONCERN THAT SUPERCELLULAR CONVECTION MOVING IN
FROM GEORGIA DURING THE EVENING WILL GET A SHOT OF INCREASED SHEAR
AS IT INTERACTS WITH A BOUNDARY. AT THE SAME TIME...THE FRONTAL ZONE
OF HEAVIER RAIN WILL MOVE INTO THE MOUNTAINS.
CONFIDENCE IN THE TIMING OF ANY MESOSCALE CONVECTIVE SYSTEMS GOES
DOWN AFTER LATE MONDAY NIGHT...BUT WE WILL RETAIN A FAVORABLE
COMBINATION OF SHEAR AND INSTABILITY TO KEEP A THREAT OF SEVERE
STORMS THROUGH TUESDAY ACROSS MOST OF THE FCST AREA...WITH PERHAPS
THE EXCEPTION OF THE WRN NC MTNS...AND INTO WEDNESDAY EAST OF THE
MOUNTAINS. ONE MIGHT EXPECT A BIT OF A LULL OR RECHARGE PERIOD
TUESDAY MORNING...BEFORE MORE ORGANIZED SEVERE WEATHER AFFECTS THE
REGION TUESDAY AFTERNOON AND EVENING WITH DIURNAL ENHANCEMENT. CAPE
PROFILES SUGGEST THAT WE MIGHT HAVE A BIT LESS OF A CHANCE OF
SUPERCELLS AND THE LIKE...BECAUSE OF CONVECTIVE DEBRIS/
OVERTURNING...BUT STILL ENOUGH OF A TORNADO THREAT FOR CONTINUED
CONCERN BECAUSE OF THE SHEAR. ADDITIONAL DETAILS WILL HOPEFULLY COME
MORE INTO FOCUS WITH SUBSEQUENT FCST PACKAGES.
AT ANY RATE...PRECIP CHANCES RAMP UP STEADILY FROM THE WEST INTO THE
LIKELY TO CATEGORICAL RANGE MONDAY NIGHT AND INTO TUESDAY AND
TUESDAY NIGHT. THE LATEST QPF GUIDANCE FROM WPC IS VERY TROUBLESOME.
ON THE ONE HAND...ANOMALY GUIDANCE DOES NOT SHOW ANYTHING OVERLY
ALARMING WITH REGARD TO PRECIPITABLE WATER...BUT ON THE OTHER HAND
THE SLOW MOVING NATURE OF THE COLD FRONT WILL PERMIT WAVES OF
MODERATE TO HEAVY RAIN STARTING EARLY TUESDAY MORNING...AND
CONTINUING INTO WEDNESDAY. UNLESS THERE IS SOME CHANGE IN
THINKING... THE NEED FOR A FLOOD WATCH IS NEARLY A FOREGONE
CONCLUSION...BUT THE MAIN THREAT OF FLOODING DOES NOT RAMP UP UNTIL
DURING THE DAY ON TUESDAY BASED ON THE QPF BREAKDOWN. SINCE THIS IS
THE 4TH FCST PERIOD AND WE HAVE SOME TIME TO GAIN MORE CONFIDENCE...
WILL HOLD OFF ON A FLOOD WATCH FOR ONE MORE FCST CYCLE.
MODEL GUIDANCE SHOWS THE FRONT CROSSING THE FCST AREA WEDNESDAY
EVENING AND THAT SHOULD BRING AN END TO MOST OF THE PRECIP...WITH
SOME LINGERING SHOWERS POSSIBLE ON THE TN BORDER OVER THE NRN MTNS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1 PM SUNDAY...EXPANSIVE UPPER TROUGH WILL REMAIN OVER THE ERN
CONUS THROUGH THE MEDIUM RANGE...WITH THE FLOW EVENTUALLY FLATTENING
BY THE END OF NEXT WEEKEND. FAIRLY UNSETTLED CONDITIONS WILL CONTINUE
ACRS THE SOUTHEAST REGION UNTIL THAT TIME. FRONTAL BOUNDARY LAYS OUT
JUST OFFSHORE FRIDAY.
GFS/EC/GEM AGREE ON A SHORTWAVE ROUNDING THE LARGER SCALE TROUGH AND
BRINGING A WAVE OUT OF THE GULF OF MEXICO ALONG THE FRONT. THEY
DISAGREE HOWEVER ON THE TIMING OF THIS EVENT. 12Z GFS/GEM DEVELOP
ONLY A WEAK WAVE FRIDAY...AND HAVE A LOW IMPACT ON OUR CWFA WITH VERY
LITTLE QPF. ORIENTATION OF THE FRONT ON THE 00Z EC LEADS IT TO
DEVELOP A STRONGER WAVE AND BRING ANOTHER ROUND OF PRECIP TO THE
PIEDMONT FRIDAY NIGHT AND SATURDAY. GFS CONCURRENTLY DEVELOPS SHOWERS
IN THE MTNS AS IT BRINGS THE WAVE ACRS EARLY SATURDAY...WITH
ADDITIONAL NW FLOW PRECIP CONTINUING INTO EARLY SUNDAY. THIS IS A
PLAUSIBLE SCENARIO THOUGH IT IS THE ONLY MODEL SHOWING IT. QPF FROM
THIS ACTIVITY IS NOTABLE BUT NOT HIGH ENOUGH FOR CONCERN...SO IT WILL
BE MINIMALLY REFLECTED IN THE FCST. IN FACT...NCEP/CMC ENSEMBLES GIVE
LITTLE SUPPORT TO A WETTER EC-LIKE SOLUTION SO POPS WILL BE KEPT ON
THE LOW SIDE FOR THE POTENTIAL FRONTAL WAVE PRECIP...ALONG WITH QPF.
AFTER ABV NORMAL TEMPS THU...TEMPS RETURN TO AROUND NORMAL FRI INTO
SAT WITH CLOUD COVER. LOWS SUNDAY MRNG SHOULD BE A COUPLE CATEGORIES
BELOW NORMAL BUT TEMPS REBOUND SUNDAY UNDER CLEARER SKIES.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AT KCLT...PUSHED THE TIMING OF THE VFR AND THEN MVFR CIGS BACK 4 TO
6 HOURS. A WEAK BACK DOOR FRONT IS STILL EXPECTED TO TURN THE WINDS
LIGHT OUT OF THE EAST OR ENE LATE TONIGHT AND THROUGH MUCH OF THE
MORNING HOURS ON MON. AND IT IS POSSIBLE THAT MVFR CIGS WILL
ACCOMPANY THE BNDRY...SO I DIDN/T REMOVE THEM...THOUGH I JUST DON/T
SEE A LOT TO FORCE LOWER CLOUDS. SHRA/TSTMS ARE EXPECTED TO FIRE UP
NEAR THE WEAK SFC FRONT MONDAY AFTN...AND THE PROB30 PERIOD OF THE
TAF HAS BEEN PUSHED BACK TO 16-20 UTC TO ACCOUNT FOR THIS.
ELSEWHERE...ALSO PUSHED BACK THE TIMING OF LOWERING CIGS AT THE
OTHER TAF SITES. AND AT KAVL PUSHED THE TIMING WAY BACK AND DIDN/T
GO AS LOW WITH THE CIGS. A FEW SHOWERS ARE POSSIBLE LATER THIS
EVENING AND VCSH HAS BEEN ADDED TO A FEW SITES TO ACCOUNT FOR THIS.
SHRA/TSTMS ARE EXPECTED TO DEVELOP OVER THE REGION MON AFTN AND
EVENING. PUSHED THE PROB30 GROUPS BACK INTO THE LATE AFTN AND EARLY
EVENING TO ACCOUNT FOR THIS. THE KHKY AIRFIELD IS EXPECTED TO REMAIN
NORTH OF THE WEAK FRONT UNTIL LATE IN THE DAY AND ONLY ADDED PROBS
FOR SHOWERS THERE.
OUTLOOK...INCREASING MOISTURE WILL BRING PERIODIC CIG AND VSBY
RESTRICTIONS IN SHRA/TSRA...AND MORNING FOG. UNSETTLED WEATHER WILL
CONTINUE UNTIL A COLD FRONT PASSAGE EARLY THURSDAY.
CONFIDENCE TABLE...
23-05Z 05-11Z 11-17Z 17-23Z
KCLT HIGH 100% MED 62% MED 67% HIGH 84%
KGSP HIGH 100% MED 62% MED 66% MED 78%
KAVL MED 62% LOW 55% LOW 54% MED 78%
KHKY HIGH 100% MED 63% HIGH 94% MED 66%
KGMU HIGH 100% MED 62% MED 66% MED 78%
KAND HIGH 100% MED 62% MED 62% HIGH 80%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...JAT/MCAVOY
SHORT TERM...PM
LONG TERM...WIMBERLEY
AVIATION...MCAVOY
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
946 PM MDT SUN APR 27 2014
.UPDATE...
ISSUED AT 939 PM MDT SUN APR 27 2014
DECIDED TO START HIGH WIND WARNING SINCE THE AREA IN THE WATCH WAS
ALREADY IN WARNING CRITERIA...KRAP GUST TO 52KT AT 0202Z. LOOKING
AT LATEST HI RES MODEL GUIDANCE...HRRR AND RAP...LOOKS LIKE 30 TO 40
MPH WINDS WILL CONTINUE THRU THE NIGHT BEFORE REALLY PICKING UP BY
13Z MONDAY. SEEING VERY STRONG DOWNSLOPE WINDS FROM THE BLACK
HILLS IN THE HIGH WIND WARNING AREA. COULD SEE SOME LIGHTER WINDS
OVERNIGHT...HOWEVER SINCE WE WERE ALREADY HAVING HIGH WINDS AND
CONFIDENCE IN HIGH WINDS FOR MONDAY AND TUESDAY WERE
HIGH...DECIDED TO GO WITH THE WARNING.
UPDATE ISSUED AT 822 PM MDT SUN APR 27 2014
DECIDED TO PUT OUT A WINTER WEATHER ADVISORY FOR SNOW FOR SHANNON
AND BENNETT COUNTIES. MADE A FEW CALLS AND LOOKING AT WEBCAMS
MARTIN ALREADY HAD AN INCH AND PINE RIDGE HAD A COUPLE INCHES.
LATEST RAP MODEL AND HRRR BOTH INDICATE A TROWAL SETTING UP OVER
THIS AREA TONIGHT. EXPECT A BAND OF HEAVY SNOW WITH AMOUNTS OF 2
TO 5 INCHES FOR THIS AREA. ONLY HAVE THE ADVISORY TIL 12Z...BUT
SNOW MAY CONTINUE A BIT LONGER. ONCE THE SNOW STOPS THE WINDS WILL
START IN THIS AREA SO KEPT WIND ADVISORY BEGINNING AT 12Z. NEXT
SHIFT MAY HAVE TO ADJUST THE TIMING DEPENDING ON THE SNOWFALL.
UPDATE ISSUED AT 640 PM MDT SUN APR 27 2014
LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER
CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER
WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM
RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS.
THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE
RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40
MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED
AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE
INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST
COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A
WIND ADVISORY OR HIGH WIND WARNING.
OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN
HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES
OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND
WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME.
&&
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 219 PM MDT SUN APR 27 2014
CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN
NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME
STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH
THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF
STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY
THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF
WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS
ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A
BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING
THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL
CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING
THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS
CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER
SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW
EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE
ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN
CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP
THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE
REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT
NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS
TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE
THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN
RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED.
ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH
PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO
THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER
THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE
MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK
HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR
THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE
RAIN IN THE AFTERNOON.
MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER
OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A
PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP
RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE
SYSTEM SLOWLY PUSHING EAST.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 219 PM MDT SUN APR 27 2014
CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE
PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE
TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS
EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE
FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT
SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE
REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL
LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE
BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF
THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY
NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD
THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN
THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A
PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE
AGAIN...ESP IN THE HIGHER TERRAIN.
TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT
RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY
TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV
INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH
STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT
FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE
GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS.
MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN
BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN
INCH OR SO.
THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW
CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE
INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK
HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT
THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY
AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY
OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR
SOME SNOW ACCUMS.
&&
.AVIATION...FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING
ISSUED AT 549 PM MDT SUN APR 27 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE PERIOD WITH
WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS.
DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF
THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE
OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY
MONDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR SDZ042-044.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM
CDT/ TUESDAY FOR SDZ001-002-012>014-025-027-032-041>044-046-
047-049.
HIGH WIND WARNING UNTIL 6 PM MDT TUESDAY FOR SDZ026-030-031-
072>074.
WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ025.
WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057.
&&
$$
UPDATE...MLS
SHORT TERM...77
LONG TERM...JC
AVIATION...MLS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
830 PM MDT SUN APR 27 2014
.UPDATE...
ISSUED AT 822 PM MDT SUN APR 27 2014
DECIDED TO PUT OUT A WINTER WEATHER ADVISORY FOR SNOW FOR SHANNON
AND BENNETT COUNTIES. MADE A FEW CALLS AND LOOKING AT WEBCAMS
MARTIN ALREADY HAD AN INCH AND PINE RIDGE HAD A COUPLE INCHES.
LATEST RAP MODEL AND HRRR BOTH INDICATE A TROWAL SETTING UP OVER
THIS AREA TONIGHT. EXPECT A BAND OF HEAVY SNOW WITH AMOUNTS OF 2
TO 5 INCHES FOR THIS AREA. ONLY HAVE THE ADVISORY TIL 12Z...BUT
SNOW MAY CONTINUE A BIT LONGER. ONCE THE SNOW STOPS THE WINDS WILL
START IN THIS AREA SO KEPT WIND ADVISORY BEGINNING AT 12Z. NEXT
SHIFT MAY HAVE TO ADJUST THE TIMING DEPENDING ON THE SNOWFALL.
UPDATE ISSUED AT 640 PM MDT SUN APR 27 2014
LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER
CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER
WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM
RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS.
THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE
RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40
MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED
AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE
INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST
COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A
WIND ADVISORY OR HIGH WIND WARNING.
OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN
HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES
OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND
WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME.
&&
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 219 PM MDT SUN APR 27 2014
CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN
NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME
STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH
THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF
STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY
THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF
WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS
ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A
BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING
THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL
CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING
THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS
CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER
SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW
EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE
ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN
CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP
THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE
REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT
NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS
TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE
THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN
RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED.
ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH
PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO
THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER
THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE
MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK
HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR
THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE
RAIN IN THE AFTERNOON.
MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER
OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A
PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP
RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE
SYSTEM SLOWLY PUSHING EAST.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 219 PM MDT SUN APR 27 2014
CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE
PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE
TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS
EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE
FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT
SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE
REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL
LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE
BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF
THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY
NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD
THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN
THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A
PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE
AGAIN...ESP IN THE HIGHER TERRAIN.
TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT
RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY
TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV
INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH
STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT
FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE
GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS.
MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN
BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN
INCH OR SO.
THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW
CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE
INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK
HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT
THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY
AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY
OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR
SOME SNOW ACCUMS.
&&
.AVIATION...FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING
ISSUED AT 549 PM MDT SUN APR 27 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE PERIOD WITH
WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS.
DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF
THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE
OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY
MONDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR SDZ042-044.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM
CDT/ TUESDAY FOR SDZ001-002-012>014-025-027-032-041>044-046-
047-049.
HIGH WIND WATCH FROM 6 AM MDT MONDAY THROUGH TUESDAY AFTERNOON
FOR SDZ026-030-031-072>074.
WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ025.
WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057.
&&
$$
UPDATE...MLS
SHORT TERM...77
LONG TERM...JC
AVIATION...MLS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
640 PM MDT SUN APR 27 2014
.UPDATE...
ISSUED AT 640 PM MDT SUN APR 27 2014
LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER
CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER
WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM
RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS.
THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE
RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40
MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED
AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE
INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST
COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A
WIND ADVISORY OR HIGH WIND WARNING.
OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN
HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES
OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND
WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME.
&&
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 219 PM MDT SUN APR 27 2014
CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN
NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME
STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH
THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF
STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY
THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF
WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS
ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A
BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING
THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL
CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING
THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS
CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER
SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW
EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE
ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN
CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP
THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE
REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT
NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS
TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE
THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN
RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED.
ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH
PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO
THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER
THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE
MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK
HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR
THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE
RAIN IN THE AFTERNOON.
MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER
OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A
PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP
RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE
SYSTEM SLOWLY PUSHING EAST.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 219 PM MDT SUN APR 27 2014
CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE
PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE
TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS
EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE
FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT
SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE
REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL
LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE
BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF
THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY
NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD
THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN
THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A
PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE
AGAIN...ESP IN THE HIGHER TERRAIN.
TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT
RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY
TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV
INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH
STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT
FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE
GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS.
MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN
BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN
INCH OR SO.
THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW
CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE
INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK
HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT
THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY
AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY
OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR
SOME SNOW ACCUMS.
&&
.AVIATION...FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING
ISSUED AT 549 PM MDT SUN APR 27 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE PERIOD WITH
WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS.
DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF
THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE
OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY
MONDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM
CDT/ TUESDAY FOR SDZ001-002-012>014-025-027-032-041>044-046-
047-049.
HIGH WIND WATCH FROM 6 AM MDT MONDAY THROUGH TUESDAY AFTERNOON
FOR SDZ026-030-031-072>074.
WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ025.
WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057.
&&
$$
UPDATE...MLS
SHORT TERM...77
LONG TERM...JC
AVIATION...MLS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1009 PM CDT SUN APR 27 2014
.UPDATE...
SHOWER AND ISOLATED TSTM ACTIVITY NOW CONFINED TO GENERALLY THE
NORTHEASTERN HALF OF THE MID STATE. LATEST HRRR SHOWS
REDEVELOPMENT OVER OUR NORTHWESTERN COUNTIES AROUND 3 OR 4 AM IN
THE MORNING. THE ACTIVITY AT THAT TIME STILL DOES NOT LOOK SEVERE.
ELSEWHERE...JUST SCT ACTIVITY IS POSSIBLE.
MODELS ARE IN AGREEMENT WITH A BUILDUP OF SUBSIDENCE TOWARD 12Z
OVER WESTERN TN. SO...ONSET OF SEVERE MAY HOLD OFF UNTIL AFTER THE
12Z-15Z WINDOW.
FOR THIS NEXT UPDATE...WILL BE LOWERING POPS FOR THE REMAINDER OF
THE OVERNIGHT. BUT...WILL AT LEAST MAINTAIN LIKELY POPS FOR MUCH
OF THE NORTHWEST. ELSEWHERE...WILL GENERALLY KEEP POPS IN THE CHC
CATEGORY.
OTW...LOW TEMPS LOOK FINE AS DEWPOINTS WILL REMAIN NEARLY STEADY.
FOR THE REMAINDER OF THE OVERNIGHT...IT DOES NOT LOOK AS THOUGH ANY
SEVERE WEATHER WILL HIT US. BUT...THAT WILL CHANGE AFTER 12Z-15Z.
&&
.PREV DISCUSSION... /ISSUED 805 PM CDT SUN APR 27 2014/
DISCUSSION...
CURRENT RADAR IMAGERY SHOWING A LARGE AMOUNT OF REFLECTIVITY
COVERAGE IN THE FORM OF SHOWERS AND NON SEVERE TSTMS. MODELS SHOW
THAT AN INCREASE IN MOISTURE DEPTH IS EXPECTED THIS EVENING AND
OVERNIGHT. WILL GO AHEAD AND UP POPS AREA WIDE.
OTW...IN TERMS OF THE SEVERE POTENTIAL ANALYSIS...LATEST SOUNDING FOR OHX
IS IN NOW. CURRENT LI IS + 1.8 AND SUPPORTS THE RELATIVELY STABLE
CONDITIONS ACROSS MIDDLE TN AT THIS TIME. THE FURTHER WEST YOU GO
HOWEVER...INSTABILITIES DO INCREASE. THE CLOSEST SEVERE WARNINGS
ARE ACROSS NW MS AND THE BOOTHEEL OF MO. THE ACTIVITY LOOKS
ESPECIALLY NASTY IN THE CENTRAL AR AREA. MODELS IN AGREEMENT AND
SUPPORT INCREASINGLY UNSTABLE AIR THE FURTHER WEST YOU GO.
THROUGH 12Z...WE REALLY SEE NO INCREASE IN INSTABILITY LEVELS OVER
MIDDLE AND EASTERN AREAS OF THE MID STATE. HOWEVER...OVER THE
WESTERN QUARTER OR SO OF MIDDLE TN...WE DO SEE A SUBSTANTIAL
DECREASE IN SHOWALTER VALUES. THE MID AND LOW LEVEL JET DYNAMICS
WILL BE ON THE INCREASE OVER WESTERN TN OVERNIGHT AS WELL. ALL IN
ALL...LOOKS LIKE NON SEVERE TSTMS OVERNIGHT EXCEPT AS WE APPROACH
12Z...THE RISK OF SEVERE WILL BEGIN TO INCREASE OVER OUR FAR
WESTERN AREAS.
AGAIN...WILL UP THE POPS FOR ALL AREAS FOR TONIGHT. UPDATES WILL
BE SENT SHORTLY.
PREV DISCUSSION... /ISSUED 717 PM CDT SUN APR 27 2014/
UPDATE...FOR 00Z TAFS.
AVIATION...
SIGNIFICANT SYSTEM TO CROSS THE MID-SOUTH THE NEXT 24 HOURS.
SHWRS/STMS EXPECTED TO AFFECT ALL SITES OFF AND ON THROUGH
THE PERIOD...WHICH WILL BRING A MULTITUDE OF VARYING CONDITIONS.
BEST CHANCE FOR STRONGEST STORMS LOOKS TO BE THE 15-00Z RANGE
MONDAY. STORMS WILL CONTAIN VERY HEAVY RAIN WHICH WILL GREATLY
REDUCES VSBYS AND POSSIBLY CIGS. STRONG STMS LIKELY TO CONTAIN
40+KT WIND GUSTS AS WELL.
PREV DISCUSSION... /ISSUED 355 PM CDT SUN APR 27 2014/
AS OF 3 PM...ISOLATED SHOWERS AND STORM DEVELOPMENT CONTINUED NORTH
OF THE WARM FRONT AND ITS ASSOCIATED CONVECTION. THE FRONT HAS BEEN
VERY SLUGGISH TO PROGRESS NORTHWARD...AND AS A RESULT...HAS RESULTED
IN SOME FLASH FLOODING CONCERNS IN NORTHERN MS. THIS ACTIVITY SHOULD
CONTINUE TO INCH NORTH THROUGH THE LATE AFTERNOON AND EVENING. STILL
THINK THAT HEAVY RAINS...FREQUENT CG STRIKES...AND SOME SMALL
HAIL/GUSTY WINDS WILL BE THE THREATS UNTIL NIGHTFALL...THEN ACTIVITY
SHOULD MELLOW AS IT EXITS NORTH OF THE STATE LINE.
REGARDING THE FORECAST SEVERE LINE OF STORMS THAT HAS BEEN
ADVERTISED FOR THE LAST FEW DAYS...HRRR/RAP/WRF HI RES MODELS
CONTINUE TO INDICATE A SEVERE LINE OF STORMS THAT SHOULD REACH THE
TN RIVER WELL AFTER MIDNIGHT. ALL THE DETERMINISTIC MODELS BLOW
THIS SQUALL LINE THROUGH THE MID STATE BY LATE MORNING MONDAY.
FOR THE PERIOD 18Z MONDAY THROUGH 06Z TUESDAY...
THIS CONTINUES TO BE THE TIMEFRAME IN WHICH THE HIGHEST POTENTIAL
FOR SEVERE WEATHER APPEARS TO BE. THE POTENTIAL FOR A WIDESPREAD
SEVERE WEATHER OUTBREAK INCLUDING VERY LARGE HAIL AND
STRONG...POTENTIALLY NUMEROUS...TORNADOES CONTINUES TO EXIST.
AFTER CLOSE EXAMINATION OF THE DETERMINISTIC MODELS...THE ONLY
NOTABLE DIFFERENCE FROM PREVIOUS FORECASTS APPEARS TO BE A
SOMEWHAT EARLIER POSSIBLE CONVECTIVE INITIATION TIMING ESTIMATE.
12Z-15Z FORECAST SOUNDINGS INDICATE VERY RAPID WARMING AND RAPIDLY
INCREASING INSTABILITY PARAMETERS FOR THE WESTERN HALF OF THE MID
STATE. SIMULTANEOUSLY...THE RIGHT EXIT REGION OF A 250 MB JET STREAK
WILL BE DEVELOPING OVER THE MS RIVER AND SHOULD BE AROUND THE TN
RIVER BY 18Z. OMEGA FIELDS ECHO THE IMPLIED DEEP LAYER LIFT
DEVELOPING IN WESTERN TN IN THE MORNING AND A VERY STRONG DYNAMIC
AND RAPIDLY DEVELOPING CONVECTIVE SET UP LOOKS TO BE IN STORE FOR
THE WESTERN TN AND WESTERN MIDDLE TENNESSEE AREAS. THE BIGGEST
QUESTION AROUND THIS TIME IS WHERE IN FACT CI WILL TAKE PLACE...AND
INTERROGATING SUBTLETIES IN THE WIND FIELDS OF ALL THE PROGGED SFC
WIND FIELDS...A SUBTLE SURFACE CONFLUENCE ZONE LOCATED JUST WEST OF
THE TN RIVER MAY BE THE LOCATION THAT THIS CI TAKES PLACE.
CONFIDENCE IS QUITE LOW IN THAT REGARD HOWEVER.
AFTER CI TAKES PLACE...THESE CELLS SHOULD BEGIN TAKING SUPERCELL
STRUCTURE AND STEERING FLOW SHOULD BE EAST NORTHEASTERLY AT ABOUT
40-50 KTS. THIS WOULD PUT ALL OF MIDDLE TENNESSEE IN THE PATH OF
VERY STRONG SUPERCELLS SHOULD THIS OUTCOME COME TO FRUITION. IF
EVERYTHING GOES AS INDICATED IN THE MODELS...THE 21Z TO 03Z
TIMEFRAME LOOKS TO BE THE TIMEFRAME OF PEAK THREAT.
OVERALL FORECAST LIMITING FACTORS...SOME OF THE VARIABLES THAT
CONTINUE TO COMPLICATE THE FORECAST. THERE IS LOWER CONFIDENCE IN
THE HI RES MODELS OF LATE DUE TO ITS INABILITY TO ACCURATELY
HANDLE THE CONVECTION FROM TODAY. THIS MAKES THE SQUALL LINE
POTENTIAL FOR TONIGHT MORE QUESTIONABLE HOWEVER THERE ARE STILL A
FEW MORE HOURS OF POTENTIAL DEVELOPMENT OUT WEST.
ADDITIONALLY...THE LARGE AMOUNTS OF RAINFALL THAT HAS BEEN
OBSERVED IN NORTHERN MS AND WESTERN TN MAY KEEP THE LOW LEVEL
ATMOSPHERE QUITE MOIST TOMORROW AND THUS KEEP LOW LEVEL CLOUD
COVER IN THE AREA IF THE PREVIOUSLY FORECAST SQUALL LINE DOES NOT
COME TO FRUITION AND CLEAR EVERYTHING OUT. THIS WOULD RESULT IN
INHIBITED INSTABILITY AND DELAY STORM DEVELOPMENT INTO THE LATER
AFTERNOON. WITH THE MULTITUDE OF VARIABLES UNKNOWN DUE TO ONGOING
CONVECTION...THESE LIMITING FACTORS ARE DIFFICULT TO ASSESS.
ADDITIONALLY...PWAT VALUES SHOULD STAY WELL ABOVE NORMAL THROUGHOUT
THE NEXT 48 HOURS. SO IN ADDITION TO THE SEVERE WEATHER
POTENTIAL...HEAVY RAIN POTENTIAL AND POSSIBLE FLASH FLOODING WILL BE
A SIGNIFICANT THREAT. HPC IS INDICATING AROUND 5 INCHES OF RAIN FROM
00Z TONIGHT THROUGH 00Z WEDNESDAY. NOTE HOWEVER THAT A LARGE PORTION
OF THIS RESTS ON WHETHER TONIGHTS STORM SYSTEM DEVELOPS AS FORECAST
IN THE SHORT RANGE MODELS.
BEYOND 06Z TUESDAY...LEFT FORECAST BASICALLY UNCHANGED WITH
ANOTHER POTENTIAL ROUND OF STRONG TO SEVERE WEATHER POSSIBLE
TUESDAY AFTERNOON AND EVENING. PREFER NOT TO ADD ANY MORE DETAILS
TO THIS FORECAST WITHOUT SEEING HOW TOMORROW UNFOLDS FIRST AS IT
WILL DIRECTLY IMPACT WHAT HAPPENS TUESDAY. BUT FOR WHAT ITS
WORTH...SPC HAS DOWNGRADED TUESDAYS THREAT FOR MIDDLE TENNESSEE TO
ONLY GENERAL THUNDERSTORMS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
752 PM CDT SUN APR 27 2014
.UPDATE...
UPDATE FOR ISOLATED THUNDERSTORMS MOVING TOWARD BURLESON AND
WASHINGTON COUNTIES FROM THE WEST.
40
&&
.DISCUSSION...
DRY LINE/COLD FRONT APPROACHING FROM THE WEST. ISOLATED
THUNDERSTORMS HAVE DEVELOPED AHEAD OF THE DRY LINE IN BASTROP AND
LEE COUNTIES AND WERE MOVING INTO BURLESON AND WASHINGTON
COUNTIES. LARGE HAIL HAS BEEN REPORTED...BUT THE STORM MOVING
THROUGH BURLESON COUNTY WEAKENED BEFORE MOVING INTO THE COUNTY.
THE 00Z CRP SOUNDING HAD A SURFACE BASED CAPE OF ALMOST 4700...
ALTHOUGH THERE WAS A DECENT CAP IN PLACE. ISOLATED STRONG TO
SEVERE STORMS ARE POSSIBLE THROUGH MID EVENING AS THE STORMS THAT
DO DEVELOP MOVE OFF THE DRYLINE...ESPECIALLY ALONG AND NORTH OF A
LINE FROM BRENHAM TO HUNTSVILLE. DO EXPECT THE STORMS TO BEGIN
LOSING INTENSITY DURING THE LATE EVENING DUE TO THE LOSS OF
DAYTIME HEATING.
40
&&
.PREV DISCUSSION... /ISSUED 641 PM CDT SUN APR 27 2014/
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
SFC ANALYSIS HAS DRYLINE ALONG THE I-35 CORRIDOR WITH A FEW ISO
STORMS WEST OF KAUS. CAP EAST OF THESE STORMS PROBABLY STRONG
ENOUGH THAT THE STORMS SHOULD WEAKEN BEFORE REACHING KCLL SO WILL
CONTINUE TO MONITOR. LEFT TAF VOID OF CONVECTION AS PROBABILITIES
SMALL AT THIS POINT.
MAIN CONCERN WILL BE LOW MVFR CIGS AHEAD OF WEAK PACIFIC FRONT.
DRIER AIR SHOULD MIX INTO THE AREA BY THE MORNING HOURS AND HELP
SCT OUT CIGS 12-15Z WITH MAINLY CLEAR SKIES AFTER THAT. WINDS
SHOULD TURN TO THE WSW/WNW DIRECTIONS AROUND 10KTS. BOUNDARY
SHOULD WORK BACK NORTH MONDAY NIGHT WITH STRONGER PACIFIC FRONT ON
TUESDAY.
39
PREV DISCUSSION... /ISSUED 310 PM CDT SUN APR 27 2014/
DISCUSSION...
VISIBLE SATELLITE SHOWS DRY LINE CLEARLY ACROSS CENTRAL TEXAS
THIS AFTERNOON. THE DRY LINE IS NOW JUST AT DALLAS- FORT WORTH AND
IS EXPECTED TO PUSH EAST THROUGH THE NIGHT. GLOBAL MODELS
CONTINUE TO OVER DUE PRECIP ACROSS THE AREA AS THE CAP HAS
REMAINED STRONG. A SPECIAL 18Z SOUNDING LAUNCH FROM TEXAS A&M
SHOWS A PRETTY STOUT CAP IN PLACE AT 750 MB. CONVECTIVE
TEMPERATURE FROM THIS SOUNDING IS IN THE MID 90S WHICH IS VERY
UNLIKELY TO OCCUR THIS AFTERNOON. HIGH RES HRRR AND TEXAS TECH WRF
STRUGGLE TO DEVELOP PRECIP THIS AFTERNOON INTO EVENING. THE HRRR
AND TEXAS TECH WRF DO TRY TO DEVELOP SOMETHING IN HOUSTON COUNTY
BUT QUICKLY MOVE IT OFF TO THE NORTHEAST. UPPER LEVEL DIFFLUENCE
ALSO APPEARS TO BE NOW MOVING OFF TO THE NORTH AND EAST WITH THE
ADVANCING UPPER LEVEL LOW. DUE TO THE MENTIONED ABOVE HAVE TRIMMED
BACK POPS AND THE MENTION OF SEVERE.
TOMORROW THE DRY LINE WILL STALL OUT ACROSS THE AREA GENERALLY
ALONG A LINE FROM WHARTON TO HARRIS TO SAN JACINTO COUNTY. BEHIND
THE DRY LINE LIGHT WEST TO NORTHWEST WINDS AND MOSTLY CLEAR SKIES
WILL ALLOW TEMPERATURES TO QUICKLY RISE. HIGHS IN THE LOWER 90S
LOOKS LIKELY. NEAR THE COAST TEMPERATURES SHOULD REMAIN MORE
CHECKED DUE TO ONSHORE WINDS AND HIGHER DEWPOINTS. STILL EXPECT
TEMPERATURES TO REACH THE LOWER 80S. TUESDAY MORNING THE DRY LINE
WILL START TO RETREAT AS THE NEXT COLD FRONT APPROACHES THE AREA.
WITH LIGHT WINDS AND RISING DEWPOINTS CAN`T RULE OUT SOME PATCHY
FOG TUESDAY MORNING. THE SURFACE COLD FRONT IS THEN EXPECTED TO
SLOWLY PUSH THROUGH THE AREA ON TUESDAY. THE GFS REMAINS VERY
QUICK WITH THE FRONT WHILE THE ECMWF... CANADIAN AND NAM 12 ARE
SLOWER. HAVE LEANED TOWARDS THE EURO AS FRONTS USUALLY SLOW DOWN
IN THE AFTERNOON IN COMBINATION WITH THE OCCLUDING MID- LATITUDE
CYCLONE.
FOR THE REST OF THE WORK WEEK BELOW NORMAL TEMPERATURES WILL BE
THE STORY AS SOUTHEAST TEXAS REMAINS ON THE BACK SIDE OF THE UPPER
LEVEL LOW. THURSDAY A SHORT WAVE WILL BEGIN TO DIVE SOUTHWARDS
HELPING TO REINFORCE THE LONG WAVE TROUGH. THIS SHORT WAVE WILL
PUSH A WEAK WIND SHIFT THROUGH THE AREA. AS THE VORT MAX MOVES SOUTHWARDS
MODELS ARE GENERATING SOME QPF. MOISTURE WILL BE LIMITED BUT CAN`T
RULE OUT THE CHANCE COMPLETELY. CURRENT FORECAST LOOKS ON TRACK
WITH THIS. 23
MARINE...
MODERATE TO STRONG ONSHORE WINDS WILL CONTINUE THROUGH TONIGHT UNDER
A TIGHT PRESSURE GRADIENT. CAUTION FLAGS ARE UP FOR THE BAYS...AND
ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS. WINDS AND SEAS WILL
COME DOWN ON MONDAY AS THE GRADIENT WEAKENS. A STRONG COLD FRONT THAT
IS EXPECTED TO BE NEAR THE COAST LATE TUESDAY AFTERNOON OR EARLY TUESDAY
EVENING WILL MOVE THROUGH THE WATERS TUESDAY NIGHT. BEHIND THE FRONT...
CAUTION FLAGS ARE LIKELY AND ADVISORIES MIGHT BE NEEDED FOR STRENGTHENING
NORTH WINDS AND BUILDING SEAS. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 65 91 62 82 51 / 30 10 10 10 10
HOUSTON (IAH) 72 91 68 86 55 / 20 20 10 10 10
GALVESTON (GLS) 73 82 72 82 62 / 20 10 10 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 AM CDT MONDAY FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT MONDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
708 PM CDT SUN APR 27 2014
.UPDATE...
LATEST MESO-ANALYSIS INDICATED A STATIONARY DRY LINE FROM BONHAM
TO MESQUITE TO NEAR CAMERON. MEANWHILE A PACIFIC COLD FRONT WAS
JUST A FEW MILES TO ITS WEST...ALONG A LINE SHERMAN TO FORT WORTH
TO LAMPASAS. WINDS BEHIND THE FRONT WERE STRONGER AND FROM THE
WEST BUT RAPID BOUNDARY LAYER DECOUPLING SHOULD OCCUR IN THE NEXT
HOUR WITH WINDS DROPPING BELOW WIND ADVISORY CRITERIA. EXPIRED
WIND ADVISORY ON TIME AT 7 PM.
MORE CONCERNING WITH THE FORECAST IS THE CONVECTIVE POTENTIAL THIS
EVENING. WITH THE SUN SETTING...THE THREAT FOR INITIATION OF
SURFACE BASED CONVECTION ALONG THE DRY LINE WILL WANE DUE TO
INCREASING CIN AND THE SEVERE WATCH WILL LIKELY EXPIRE AT 8PM.
THE DRY LINE WILL MOVE BACK TO THE WEST AFTER SUNSET AS IS OFTEN
THE CASE...LIKELY MEETING OR PERHAPS ALSO PUSHING THE PACIFIC
FRONT BACKWARD. THE FRONT IS AWAITING A PUSH FROM A STRONG
SHORTWAVE THAT WILL ARRIVE LATER THIS EVENING...WITH STRONG UPWARD
FORCING BEGINNING TO SPREAD ACROSS THE REGION AFTER 10 PM. WHILE
SURFACE BASED CONVECTION FIRING ALONG A WESTWARD RETREATING DRY
LINE DURING THE EVENING IS RARE DUE TO INCREASED CIN...IT DOES
HAPPEN OCCASIONALLY.
INSTEAD WHAT IS LIKELY TO HAPPEN IS THAT UPWARD FORCING OCCURRING
IN THE PRESENCE OF NEARLY DRY ADIABATIC LAPSE RATES UP TO 14000
FEET WILL SQUEEZE OUT WHATEVER MOISTURE IT CAN FIND FOR ELEVATED
HIGH BASED CONVECTION. MODEL SOUNDINGS FROM THE RAP ARE MOST
AGGRESSIVE WITH THIS SCENARIO...AND SUGGEST ISOLATED TO SCATTERED
ELEVATED THUNDERSTORMS DEVELOPING ALONG THE I-35 CORRIDOR AND
GATHERING STRENGTH AS THEY HEAD INTO THE DEEPER MOISTURE ACROSS
THE EASTERN ZONES. OBVIOUSLY ANY STORMS IN THIS ENVIRONMENT WILL
HAVE A LARGE HAIL THREAT. WHILE THIS IS A POSSIBLE SCENARIO...IT
IS UNCERTAIN RIGHT NOW HOW LIKELY IT IS. THEREFORE WE WILL KEEP
POPS AT 20-30 PERCENT THROUGH 1 AM OVER AREAS JUST EAST OF I-35
AND CONTINUE TO WATCH TRENDS IN SATELLITE AND RADAR DATA FOR
ADDITIONAL DEVELOPMENT LATER THIS EVENING.
TR.92
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED BUT STILL A SLIGHT POSSIBILITY SOME
DUST MAY EFFECT THE METROPLEX SITES...BUT THIS SHOULD REMAIN
NORTHWEST OF TAF SITES.
OTHERWISE THE DRY LINE IS STATIONARY JUST EAST OF KDAL AND
KACT...WITH A PACIFIC COLD FRONT ANALYZED BETWEEN DFW AND FTW/AFW.
WINDS BEHIND THE PACIFIC FRONT WERE STRONGER AND MORE WESTERLY
BUT WITH SUNSET APPROACHING THESE WINDS SHOULD NOT BE TOO STRONG
AND NO CROSSWIND ISSUES ARE EXPECTED AT DFW/DAL THIS EVENING. DRY
LINE WILL TRY TO HEAD BACK TO THE WEST AND WINDS MAY BECOME LIGHT
SOUTHERLY BEHIND IT FOR DFW/GKY AND ESPECIALLY DAL THIS EVENING.
THERE IS SOME CONCERN FOR REDEVELOPMENT OF CONVECTION AND STORMS
TONIGHT AS STRONG UPPER FORCING ARRIVES. CONFIDENCE IS LOW BUT
STILL A BIT NERVOUS ABOUT FORCING ARRIVING WITH DRY LINE STILL IN
THE AREA. WILL SHOW VCTS FOR DAL/ACT FROM 4Z TO 8Z. BELIEVE THIS
ACTIVITY...SHOULD IT DEVELOP...WILL BE HIGH BASED ALONG I-35
CORRIDOR...BUT MAY RESULT IN LIGHTNING STRIKES. THE MORE ROBUST
CONVECTION SHOULD BE EAST OF TAF SITES LATER TONIGHT...SHOULD IT
DEVELOP.
WEST WINDS NEAR 10-15KT AND VFR WILL PREVAIL TOMORROW.
TR.92
&&
.PREV DISCUSSION... /ISSUED 319 PM CDT SUN APR 27 2014/
DRYLINE/SURFACE TROUGH CONTINUES MOVING EAST AND CURRENTLY
EXTENDED FROM NEAR BONHAM...TO DALLAS...TEMPLE AND WAS MOVING
SLOWLY EAST. ONE ISOLATED STRONG STORM WAS UP NEAR BONHAM WITH
ANOTHER POTENTIALLY DEVELOPING CELL OVER EASTERN COLLIN CO...
OTHERWISE IT REMAINED QUIET. DESPITE SURFACE DEW POINTS BETWEEN
65-70 DEGREES...WARM TEMPERATURES...INSTABILITY ABOVE 2000 J/K AND
GOOD SHEAR...LOW LEVEL CONVERGENCE ACROSS OUR CENTRAL TEXAS
COUNTIES WAS NOT AS GOOD DUE TO SLIGHTLY VEERED FLOW AHEAD OF THE
DRYLINE. THIS MAY CHANGE AS A 300MB SPEED MAX CONTINUES ROTATING
NORTHEAST THROUGH 00Z AND HELPS TRIGGER ISOLATED STORMS...POSSIBLY
MORE SCATTERED IN THE FAR E/NE FROM CORSICANA/ATHENS NORTHWARD.
QUICK CHAT WITH SPC WAS THAT CURRENT SEVERE THUNDERSTORM WATCH 94
WOULD BE ALLOWED TO EXPIRE AT 3 PM AND REPLACED BY SEVERE
THUNDERSTORM WATCH 99 FOR OUR FAR EAST CENTRAL AND NORTHEAST
COUNTIES THROUGH 8 PM. SEVERE STORMS ARE ALREADY DEVELOPING
RAPIDLY AND BECOMING SEVERE BETWEEN BONHAM AND PARIS WITH OTHER
SIGNS OF DEVELOPMENT SOUTHWEST TOWARD ROCKWALL AND TERRELL. LOOK
FOR A 10-30 PERCENT COVERAGE OF POSSIBLE STRONG TO SEVERE STORMS
ACROSS THE EASTERN THIRD OF NORTH TEXAS INTO EARLY EVENING WITH
HAIL AND DAMAGING WINDS THE MAIN THREATS DUE TO THE AFOREMENTIONED
SLIGHTLY VEERED FLOW AHEAD OF THE DRYLINE.
BEHIND THE DRYLINE...GUSTY WEST-SOUTHWEST WINDS 20 TO 30 MPH WITH
GUST 35 TO 40 MPH ARE EXPECTED AND MAY RESULT IN SOME BLOWING DUST
FROM THE DFW METROPLEX NORTH AND WEST THROUGH MID EVENING. BEYOND MID
EVENING...WE EXPECT THE DRYLINE TO REACH OUR EASTERN EDGE AND RISK
FOR SEVERE STORMS MOVING INTO EAST TEXAS...THE ARKLATEX AND MID MS
VALLEY. DRIER AIR TONIGHT COMBINED WITH DIMINISHING WEST WINDS
SHOULD ALLOW FOR A COOL AND PLEASANT NIGHT...BEFORE ANOTHER WINDY...
DRY AND VERY WARM DAY ENSUES MONDAY WITH FIRE WEATHER CONCERNS AND
POSSIBLY ANOTHER WIND ADVISORY NEEDING TO BE ISSUED. WEST-
SOUTHWEST WINDS 15-25 MPH AND GUSTY ARE EXPECTED OR POSSIBLY
SLIGHTLY HIGHER BY MONDAY AFTERNOON.
THE FIRST OF SEVERAL COLD FRONTAL SURGES IS EXPECTED TO ARRIVE
MONDAY NIGHT INTO TUESDAY MORNING. MEANWHILE...ANOTHER STRONG
CYCLONICALLY CURVED SHORTWAVE WILL ROTATE ACROSS THE RED RIVER
WITH MOST MOISTURE ANCHORED ABOVE 700MB. ONLY MENTIONED ISOLATED
HIGH-BASED OR ELEVATED SHOWERS FOR THIS PERIOD...THOUGH EVENTUALLY
THUNDER MAY NEED TO BE INTRODUCED IF LAPSE RATES REMAIN HIGH. THE
LOW LEVELS WILL REMAIN VERY DRY...SO LITTLE MEASURABLE RAINFALL
WOULD OCCUR WITH THE FRONTAL PASSAGE. MAY WELL BE JUST SOME VIRGA
WOULD COULD POSSIBLY TRANSLATE SOME GUSTIER NORTHWEST WINDS DOWN
THE SURFACE BY TUESDAY MORNING.
AFTERWARD...A DRY AND SEASONABLY COOL PERIOD IS EXPECTED WITH THE
DRY CONTINENTAL AIRMASS BEING SUPPORTED BY STALLING AND OCCLUDING
UPPER LOW PIN-BALLING OVER THE MID MISSISSIPPI VALLEY AND MIDWEST.
AS NOTED IN PREVIOUS DISCUSSIONS...THE REASON FOR THE UPPER LEVEL
LOW REMAINING STATIONARY IS A BLOCKING UPPER HIGH OVER EASTERN
CANADA. THE AIRMASS WILL BE UNUSUALLY DRY FOR HEADING INTO EARLY
MAY AND ALLOW FOR A LARGE DIURNAL RANGE ON LOWS AND HIGHS WITH
45-50 FOR LOWS AND HIGHS 70-75...EXCEPT SLIGHTLY WARMER OVER
CENTRAL TEXAS. FLOW ALOFT OVER NORTH TEXAS DAMPENS BY NEXT WEEKEND
AS THE EASTERN CANADIAN RIDGE FINALLY WEAKENS AND ALLOW THE
OCCLUDED UPPER LOW TO BE OPENED UP AND CARRIED QUICKLY EAST.
SOUTHERLY LOW LEVEL FLOW THEN RETURNS AND HIGHS REBOUND BACK INTO
THE 80S.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 58 84 52 75 50 / 5 5 10 10 5
WACO, TX 56 87 51 80 47 / 20 5 5 5 5
PARIS, TX 57 79 51 72 46 / 30 5 10 10 5
DENTON, TX 52 84 48 74 45 / 5 5 10 5 5
MCKINNEY, TX 53 84 49 73 46 / 20 5 10 10 5
DALLAS, TX 62 86 54 75 51 / 5 5 10 10 5
TERRELL, TX 57 83 52 75 47 / 30 5 10 10 5
CORSICANA, TX 58 86 55 78 48 / 30 5 5 10 5
TEMPLE, TX 59 88 55 79 48 / 20 5 5 5 5
MINERAL WELLS, TX 52 87 49 76 47 / 5 5 10 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
641 PM CDT SUN APR 27 2014
.DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
&&
.AVIATION...
SFC ANALYSIS HAS DRYLINE ALONG THE I-35 CORRIDOR WITH A FEW ISO
STORMS WEST OF KAUS. CAP EAST OF THESE STORMS PROBABLY STRONG
ENOUGH THAT THE STORMS SHOULD WEAKEN BEFORE REACHING KCLL SO WILL
CONTINUE TO MONITOR. LEFT TAF VOID OF CONVECTION AS PROBABILITIES
SMALL AT THIS POINT.
MAIN CONCERN WILL BE LOW MVFR CIGS AHEAD OF WEAK PACIFIC FRONT.
DRIER AIR SHOULD MIX INTO THE AREA BY THE MORNING HORUS AND HELP
SCT OUT CIGS 12-15Z WITH MAINLY CLEAR SKIES AFTER THAT. WINDS
SHOULD TURN TO THE WSW/WNW DIRECTIONS AROUND 10KTS. BOUNDARY
SHOULD WORK BACK NORTH MONDAY NIGHT WITH STRONGER PACIFIC FRONT ON
TUESDAY.
39
&&
.PREV DISCUSSION... /ISSUED 310 PM CDT SUN APR 27 2014/
DISCUSSION...
VISIBLE SATELLITE SHOWS DRY LINE CLEARLY ACROSS CENTRAL TEXAS
THIS AFTERNOON. THE DRY LINE IS NOW JUST AT DALLAS- FORT WORTH AND
IS EXPECTED TO PUSH EAST THROUGH THE NIGHT. GLOBAL MODELS
CONTINUE TO OVER DUE PRECIP ACROSS THE AREA AS THE CAP HAS
REMAINED STRONG. A SPECIAL 18Z SOUNDING LAUNCH FROM TEXAS A&M
SHOWS A PRETTY STOUT CAP IN PLACE AT 750 MB. CONVECTIVE
TEMPERATURE FROM THIS SOUNDING IS IN THE MID 90S WHICH IS VERY
UNLIKELY TO OCCUR THIS AFTERNOON. HIGH RES HRRR AND TEXAS TECH WRF
STRUGGLE TO DEVELOP PRECIP THIS AFTERNOON INTO EVENING. THE HRRR
AND TEXAS TECH WRF DO TRY TO DEVELOP SOMETHING IN HOUSTON COUNTY
BUT QUICKLY MOVE IT OFF TO THE NORTHEAST. UPPER LEVEL DIFFLUENCE
ALSO APPEARS TO BE NOW MOVING OFF TO THE NORTH AND EAST WITH THE
ADVANCING UPPER LEVEL LOW. DUE TO THE MENTIONED ABOVE HAVE TRIMMED
BACK POPS AND THE MENTION OF SEVERE.
TOMORROW THE DRY LINE WILL STALL OUT ACROSS THE AREA GENERALLY
ALONG A LINE FROM WHARTON TO HARRIS TO SAN JANCINTO COUNTY.
BEHIND THE DRY LINE LIGHT WEST TO NORTHWEST WINDS AND MOSTLY CLEAR
SKIES WILL ALLOW TEMPERATURES TO QUICKLY RISE. HIGHS IN THE LOWER
90S LOOKS LIKELY. NEAR THE COAST TEMPERATURES SHOULD REMAIN MORE
CHECKED DUE TO ONSHORE WINDS AND HIGHER DEWPOINTS. STILL EXPECT
TEMPERATURES TO REACH THE LOWER 80S. TUESDAY MORNING THE DRY LINE
WILL START TO RETREAT AS THE NEXT COLD FRONT APPROACHES THE AREA.
WITH LIGHT WINDS AND RISING DEWPOINTS CAN`T RULE OUT SOME PATCHY
FOG TUESDAY MORNING. THE SURFACE COLD FRONT IS THEN EXPECTED TO
SLOWLY PUSH THROUGH THE AREA ON TUESDAY. THE GFS REMAINS VERY
QUICK WITH THE FRONT WHILE THE ECMWF... CANADIAN AND NAM 12 ARE
SLOWER. HAVE LEANED TOWARDS THE EURO AS FRONTS USUALLY SLOW DOWN
IN THE AFTERNOON IN COMBINATION WITH THE OCCLUDING MID- LATITUDE
CYCLONE.
FOR THE REST OF THE WORK WEEK BELOW NORMAL TEMPERATURES WILL BE
THE STORY AS SOUTHEAST TEXAS REMAINS ON THE BACK SIDE OF THE UPPER
LEVEL LOW. THURSDAY A SHORT WAVE WILL BEGIN TO DIVE SOUTHWARDS
HELPING TO REINFORCE THE LONG WAVE TROUGH. THIS SHORT WAVE WILL
PUSH A WEAK WIND SHIFT THROUGH THE AREA. AS THE VORT MAX MOVES SOUTHWARDS
MODELS ARE GENERATING SOME QPF. MOISTURE WILL BE LIMITED BUT CAN`T
RULE OUT THE CHANCE COMPLETELY. CURRENT FORECAST LOOKS ON TRACK
WITH THIS. 23
MARINE...
MODERATE TO STRONG ONSHORE WINDS WILL CONTINUE THROUGH TONIGHT UNDER
A TIGHT PRESSURE GRADIENT. CAUTION FLAGS ARE UP FOR THE BAYS...AND
ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS. WINDS AND SEAS WILL
COME DOWN ON MONDAY AS THE GRADIENT WEAKENS. A STRONG COLD FRONT THAT
IS EXPECTED TO BE NEAR THE COAST LATE TUESDAY AFTERNOON OR EARLY TUESDAY
EVENING WILL MOVE THROUGH THE WATERS TUESDAY NIGHT. BEHIND THE FRONT...
CAUTION FLAGS ARE LIKELY AND ADVISORIES MIGHT BE NEEDED FOR STRENGTHENING
NORTH WINDS AND BUILDING SEAS. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 65 91 62 82 51 / 10 10 10 10 10
HOUSTON (IAH) 72 91 68 86 55 / 20 20 10 10 10
GALVESTON (GLS) 73 82 72 82 62 / 20 10 10 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: BRAZORIA...CHAMBERS...FORT BEND...GALVESTON...
HARRIS...JACKSON...LIBERTY...MATAGORDA...WHARTON.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 AM CDT MONDAY FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT MONDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
415 PM CDT SAT APR 26 2014
.SHORT TERM...
(Tonight and Sunday)
Conditionally severe thunderstorm threat tonight, mainly in the Big
Country and Concho Valley. West Central Texas is certainly unstable
with RUC SB CAPES up to 3000 J/KG, but warm air aloft may prevent
storms from occurring. Surface Observations show only weak low level
convergence along the dryline. Some virga indicated in the Big
Country from Abilene to west of Wichita Falls, but the mid level
instability associated with it appears to be fairly high, above
10000 FT AGL.
Both the GFS and the HRRR models develop isolated storms in the Big
Country this evening, with the GFS the only one to develop storms
later tonight, as a Pacific front catches up with dryline towards
midnight. Region should become more unstable as cooler air aloft
moves in as an upper trough approaches. There will also be stronger
low level convergence, with west winds behind the Pacific front. But
storm development is still conditional.
Strong downslope west warming winds expected Sunday behind the
Pacific Front. Should see Wind Advisory criteria of 25 to 35 mph,
with gusts to 45 mph by midmorning. Have a Red Flag Warning for
dangerous fire conditions from 11 AM to 10 PM.
.FIRE WEATHER...
A Red Flag Warning for fire weather is in effect for West Central
Texas from 11 AM to 10 PM.
Dangerous fire weather conditions Sunday as the dryline and Pacific
front sweep through, bringing dry and windy west winds Minimum RH
values will fall near 10 percent with 20 foot west winds of 20 to 30
mph gusting to 35 mph. Added Mason and San Saba counties to the Red
Flag Warning as 20 foot winds will be close to 20 mph.
Elevated fire weather conditions are also expected Monday due to
gusty west winds and very dry conditions.
.LONG TERM...
(Sunday night through next Saturday)
Warm and dry weather will prevail on Monday, with cooler
temperatures Tuesday through next Friday.
The large closed upper low will be centered over the Central Plains
late this weekend, and will move slowly northeast to the Great Lakes
region by mid week. Associated surface low currently over eastern
Colorado this evening, will move northeast into eastern Nebraska
Sunday evening. Monday will be another warm day with gusty west
winds once again with afternoon highs in the mid and upper 80s.
A cold front will move across the area Monday night, bringing much
cooler temperatures for Tuesday, with highs mainly in the 70s.
Northwest flow aloft will prevail across the area Tuesday through
much of next week. A persistent surface ridge will remain in place
and will result in unseasonably cool temperatures for West Central
Texas through Friday. High temperatures through Friday will be
mainly in the 70s, with overnight lows in the 40s and 50s. Warmer
weather is expected next weekend with near seasonal temperatures.
No rain is forecast through the period.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 92 63 88 51 83 / 20 40 0 0 0
San Angelo 94 63 90 51 88 / 10 30 0 0 0
Junction 90 66 92 50 90 / 10 30 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING from 11 AM to 10 PM CDT Sunday FOR THE
FOLLOWING ZONES: Brown...Callahan...Coke...Coleman...Concho...
Crockett...Fisher...Haskell...Irion...Jones...Kimble...Mason...
McCulloch...Menard...Nolan...Runnels...San Saba...Schleicher...
Shackelford...Sterling...Sutton...Taylor...Throckmorton...Tom
Green.
WIND ADVISORY from 10 AM to 7 PM CDT Sunday FOR THE FOLLOWING
ZONES: Callahan...Coke...Coleman...Concho...Crockett...Fisher...
Haskell...Irion...Jones...Nolan...Runnels...Schleicher...
Shackelford...Sterling...Taylor...Throckmorton...Tom Green.
&&
$$
04/24
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
100 AM CDT SAT APR 26 2014
.DISCUSSION...SEE AVIATION BELOW FOR 06Z TAF UPDATE.
&&
.AVIATION...MVFR TO IFR CEILINGS ONCE AGAIN FILLING IN ACROSS THE
REGION TONIGHT. EXPECT LOW CLOUD DECK TO REMAIN OVER THE REGION
OVERNIGHT AND INTO THE MID MORNING. LIGHT PATCHY FOG WILL ALSO
SLIGHTLY IMPACT VISIBILITIES ACROSS THE REGION...BUT WITH WINDS
OVERNIGHT REMAINING MORE ELEVATED THAN YESTERDAY...NOT EXPECTING
FOG TO BECOME DENSE. LOWEST VSBYS WILL OCCUR AOA
KVCT...TEMPORARILY DROPPING TO IFR CRITERIA IN THE EARLY MORNING THROUGH
SUNRISE. EXPECT INCREASED SOUTH TO SOUTHEAST WINDS DURING THE DAY
SATURDAY. DURING THE EARLY AFTERNOON CEILINGS WILL LIFT AND
DISSIPATE ENOUGH FOR VFR CRITERIA AT KVCT...KALI...AND KLRD.
MVFR CEILINGS WILL LINGER OVER KCRP DURING THE AFTERNOON HOWEVER.
SIMILAR CONDITIONS WILL BE LIKELY DURING THE LATE OVERNIGHT HOURS
THEN ONCE AGAIN.
&&
.PREV DISCUSSION... /ISSUED 730 PM CDT FRI APR 25 2014/
DISCUSSION...THE PAST SEVERAL RUNS OF THE HRRR HAVE CONTINUED TO
INDICATE THAT SOME OF THE ONGOING SIERRA MADRE CONVECTION MAY
AFFECT WESTERN PORTIONS OF WEBB COUNTY LATER THIS EVENING BEFORE
EVENTUALLY DISSIPATING IN AN INCREASINGLY CAPPED ENVIRONMENT.
CURRENT RADAR TRENDS LEAD CREDENCE TO THE HRRR. WL THUS INTRODUCE
SLIGHT CHC POPS FOR WESTERN WEBB COUNTY FOR THIS EVENING.
OTHERWISE...MOSTLY MINOR CHANGES WERE MADE FOR THIS EVENING
PACKAGE BASED UPON CURRENT AND EXPECTED TRENDS. MORE WIND TNT WL
KEEP FOG FROM GETTING TOO WIDESPREAD AND TOO LOW VSBY-WISE.
MARINE...THE OVERALL GRADIENT HAS INCREASED FROM 24 HOURS AGO BUT
IS STILL EXPECTED TO REMAIN BELOW SCA THRESHOLDS FOR TNT. DID
LOWER THE WAVEHEIGHTS BY AROUND 1 FOOT FROM THE PREVIOUS PACKAGE
FOR TONIGHT AND SATURDAY. AN INCREASING GRADIENT/LLJ IN RESPONSE
TO AN APPROACHING STRONG S/WV CURRENTLY MOVING THROUGH CALIFORNIA
WL PRODUCE SCA CONDITIONS FOR THE SRN BAYS SATURDAY AFTN AND MOST
AREAS SAT NIGHT INTO SUNDAY.
PREV DISCUSSION... /ISSUED 632 PM CDT FRI APR 25 2014/
DISCUSSION...SEE AVIATION SECTION FOR 00Z TAFS.
AVIATION...OTHER THAN SOME SPOTTY MVFR CEILINGS NEAR THE COAST...VFR
CONDITIONS WILL CONTINUE OVER THE REGION DURING THE EARLY EVENING HOURS.
EXPECT STRATUS/MVFR CEILINGS AROUND 1500 FEET TO DEVELOP OVER THE COASTAL
PLAINS 03-04Z. CEILINGS ARE EXPECTED TO LOWER TO IFR FROM 06-07Z WITH
MVFR VSBYS WITH FOG OVER COASTAL SITES. OCCASIONAL IFR VSBYS WILL BE
POSSIBLE OVER THE VICTORIA CROSSROADS BEFORE SUNRISE. MVFR CIGS WILL
SPREAD WEST INTO LAREDO AREA BY 08Z AND PERSIST UNTIL 16Z SATURDAY.
WILL CONTINUE TO MONITOR ISOLATED CONVECTION THAT DEVELOPED OVER THE
HIGHER TERRAIN IN NORTHEAST MEXICO AHEAD OF A WEAK UPPER LEVEL
DISTURBANCE. ADVECTION OF DRIER AIR IN THE LOWER LEVELS SHOULD INHIBIT
ACTIVITY FROM REACHING THE RIO GRANDE LATER THIS EVENING. MVFR CIGS
WILL PERSIST THROUGH THE MORNING WITH CLOUDS SCATTERING OUT FOR MOST
OF THE REGION EXCEPT FOR THE COASTAL BEND WHERE MVFR CIGS MAY PERSIST
THROUGH THE AFTERNOON.
PREV DISCUSSION... /ISSUED 323 PM CDT FRI APR 25 2014/
SHORT TERM...25 TO 30 KT LLJ EXPECTED TO DEVELOP TONIGHT IN RESPONSE
TO A DEEPENING LOW PRESSURE SYSTEM OVER THE HIGH PLAINS. THIS...IN
COMBINATION WITH AMPLE MOISTURE TO AID IN NOCTURNAL STRATUS
DEVELOPMENT...SHOULD PREVENT MUCH IN THE WAY OF FOG DEVELOPMENT
TONIGHT...THOUGH WIDESPREAD LOW STRATUS IS LIKELY. AFTER THE CLOUD
DECK BURNS OFF...TOMORROW WILL SEE TEMPS ABOVE AVERAGE...BECOMING
DOWNRIGHT TOASTY OVER THE WESTERN BRUSH COUNTRY AS A DRYLINE
CROSSES THE RIO GRANDE IN THE AFTERNOON WITH NEAR TRIPLE DIGIT
HIGHS. BY LATE AFTERNOON...UPPER LEVEL DIFLUENCE FROM THE PHASING
OF THE POLAR AND SUBTROPICAL JETS WILL BEGIN TO AFFECT THE REGION.
30-40 KT 0-6 KM BULK SHEAR...2000-3000 J/KG OF MLCAPE...AND
MODERATE HELICITY VALUES MAY ALLOW FOR SOME STRONG THUNDERSTORMS
TO DEVELOP...PARTICULARLY DEVELOPING OFF OF THE SIERRA MADRE AND
CROSSING THE RIO GRANDE. THE STORM ENVIRONMENT LOOKS TO BE
SLIGHTLY LESS FAVORABLE NEAR THE COAST...BUT HAVE STILL INCLUDED
MUCH OF THE AREA WITH 20 POPS. THE ENVIRONMENT WILL REMAIN
FAVORABLE OVERNIGHT.
LONG TERM (SUNDAY THROUGH FRIDAY)...PERIOD COULD BEGIN ACTIVE WITH
THUNDERSTORMS /POSSIBLY MCS/ MOVING EASTWARD THROUGH THE CWA AS
THETA E RIDGE PROGRESSES EASTWARD. MOST OF THE AREA SHOULD BE CAPPED
WITH 850 TEMPS 20 DEGREES OR HIGHER...BUT IF CONVECTION DEVELOPS IT
MAY SUSTAIN ITSELF INTO NORTHEASTERN PARTS OF CWA.
DRYLINE MOVES THROUGH MUCH OF THE AREA ON SUNDAY WITH TEMPERATURES
VERY WARM...INTO THE 90S FOR MOST OF THE AREA...WITH ABOVE 100
DEGREES POSSIBLE ALONG THE RIO GRANDE. THIS IS DEPENDENT THOUGH ON
ANY LINGERING MID/HIGH CLOUD THAT COULD BE LEFTOVER FROM POTENTIAL
MCS SATURDAY NIGHT/SUNDAY. MONDAY HAS SIMILAR SETUP...BUT WITHOUT
THE CAVEAT OF MID/HIGH CLOUDS. SHOULD SEE HOT TEMPERATURES BEHIND
DRYLINE THAT WILL MOVE THROUGH MOST OF THE AREA.
TRICKY TEMPERATURES FOR TUESDAY WITH COLD FRONT TIMING AROUND NOON.
WILL SEE SOME /THOUGH NOT SIGNIFICANT/ COLD ADVECTION BEHIND THE
FRONT...SO THINK TEMPS SHOULD BE SEVERAL DEGREES COOLER THAN
MONDAY...THOUGH STILL IN THE 90S UNLESS TIMING SPEEDS UP. MOISTURE
POOLING ALONG AND OFF THE COAST WILL PRODUCE A SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS MAINLY IN OFFSHORE AREAS TUESDAY WITH THE
FRONT.
COLD FRONT SHOULD KNOCK TEMPERATURES BACK INTO THE 80S FOR THE
FOLLOWING FEW DAYS WITH MUCH DRIER CONDITIONS AS DPTS DROP TO MUCH
MORE PLEASANT LEVELS /40S AND 50S/. ONSHORE FLOW REDEVELOPS LATE
THURSDAY AND WILL BRING A GRADUAL INCREASE IN MOISTURE FOR FRIDAY.
MODELS NOT IN GOOD AGREEMENT FOR FRIDAY...BUT MODELS HINTING AT
ANOTHER UPPER TROUGH FOR FRIDAY INTO THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 88 73 94 71 92 / 10 20 20 10 10
VICTORIA 87 71 88 69 92 / 10 20 30 10 10
LAREDO 99 73 101 71 99 / 20 30 10 10 10
ALICE 93 73 97 70 96 / 10 30 20 10 10
ROCKPORT 81 71 82 72 85 / 10 20 30 10 10
COTULLA 95 71 98 68 97 / 20 30 10 10 10
KINGSVILLE 91 73 96 71 95 / 10 20 20 10 10
NAVY CORPUS 83 73 83 72 82 / 10 20 20 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
LK/84...AVIATION
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1139 PM CDT FRI APR 25 2014
.AVIATION...
SURFACE DEWPOINTS ARE NOW IN THE LOW 60S ACROSS CENTRAL AND
SOUTHEAST TEXAS AND MOISTURE WILL CONTINUE TO SURGE NORTHWARD
THROUGH THE TAF SITES DURING THE NEXT FEW HOURS. SURFACE TEMPS
SHOULD BE WARM ENOUGH TO LIMIT ANY ADVECTION FOG...BUT LOW STRATUS
APPEARS LIKELY FOR KACT AFTER 10Z. MVFR/IFR STRATUS IS NOW
BEGINNING TO FORM ACROSS THE TEXAS COASTAL PLAINS...AND WACO MAY
CONTEND WITH MVFR OR PERHAPS BRIEF IFR STRATUS AROUND AND SHORTLY
AFTER DAYBREAK. STRATUS MAY STRUGGLE TO REACH AS FAR NORTH AS THE
METROPLEX...BUT WILL SHOW TEMPO MVFR CIGS FROM 12-14Z FOR
DFW/DAL/GKY WHERE SOME OF THE HIGH RES GUIDANCE AND THE RUC/NAM
INDICATE LOW LEVEL SATURATION OCCURRING. ANY STRATUS SHOULD
LIFT/SCATTER FAIRLY QUICKLY BY MID MORNING. ASIDE FROM MID-HIGH
CLOUDS JUST SOME FAIR WEATHER CUMULUS EXPECTED SATURDAY AFTERNOON
AND EVENING WITH SOUTH WINDS INCREASING TO NEAR 20KT AND GUSTY.
MVFR STRATUS WILL LIKELY RETURN AROUND MIDNIGHT SATURDAY NIGHT TO
THE TAF SITES. THUNDERSTORMS SHOULD REMAIN WELL WEST AND NORTHWEST
OF THE TAF SITES TOMORROW EVENING. HOWEVER...ELEVATED CONVECTION
WILL LIKELY BEGIN TO AFFECT THE TAF SITES BY 9Z AND HAVE INDICATED
A VCTS TO COVER THIS THREAT. MODELS CONTINUE TO INDICATE
DRYLINE/PACIFIC FRONT WILL MOVE EAST OF TAF SITES BY SUNDAY
AFTERNOON BEFORE NEXT ROUND OF SEVERE CONVECTION FIRES...BUT STILL
NEED TO MONITOR THIS POTENTIAL.
TR.92
&&
.UPDATE...
QUICK UPDATE TO THE FORECAST TO ADD A LITTLE MORE CLOUD COVER
EARLY SATURDAY MORNING...MAINLY TO THE SOUTHERN HALF OF THE CWA AS
STRONG MOISTURE RETURN CONTINUES. A LOOK AT THE LATEST NAM
GUIDANCE CONTINUES TO SHOW SEVERE CONVECTIVE POTENTIAL TOMORROW
AFTERNOON/EVENING ACROSS WEST CENTRAL TEXAS. NO CHANGES MADE TO
THE CURRENT CONVECTIVE FORECAST FOR TOMORROW INTO TOMORROW NIGHT.
THE RAP DOES SHOW SOME WEAKENING OF THE CAP EARLIER IN THE
AFTERNOON OUT WEST WHICH COULD LEAD TO A SLIGHTLY EARLIER
INITIATION TIME BUT OTHERWISE THE GENERAL THINKING IS UNCHANGED.
FOR SUNDAY...MODEL GUIDANCE IS IN GOOD AGREEMENT WITH MOVING THE
DRYLINE/FRONT EAST INTO SUNDAY MORNING...ACTUALLY BEHAVING MORE
LIKE A FRONT WITH COOLING TEMPERATURES BEHIND IT AT 850MB. IT IS
APPEARING MORE LIKELY THAT THIS FEATURE WILL BE ALONG OR EAST OF
I-35 BEFORE SURFACE BASED CONVECTION CAN DEVELOP ON SUNDAY. THE
HIGHEST THREAT FOR SEVERE WEATHER ON SUNDAY WILL BE ACROSS THE
EASTERN COUNTIES INTO THE ARKLATEX. SOME ELEVATED CONVECTION IS
EXPECTED TO BE ONGOING EARLY SUNDAY MORNING AND THIS COULD QUICKLY
BECOME SURFACE BASED BY EARLY AFTERNOON GENERALLY EAST OF I-35.
CURRENT FORECAST HANDLES THIS WELL AND NO CHANGES ARE NEEDED AT
THIS TIME.
DUNN
&&
.SHORT TERM/THOUGH MONDAY/...
A STRONG UPPER LOW CONTINUES MOVING INLAND OVER THE WESTERN STATES
WITH A SHORTWAVE RIDGE ACROSS NORTH AND CENTRAL TEXAS LINGERING
THROUGH TONIGHT. THIS SYSTEM IS A WAYS OFF WITH A SUBSTANTIAL CAP
THAT SHOULD KEEP THE WEATHER DRY TONIGHT AND THROUGH THE DAY
SATURDAY. BREEZY SOUTH WINDS AND RAPIDLY INCREASING DEW POINTS
FROM THE TEXAS COASTAL AREAS ARE EXPECTED TO HOLD LOWS TONIGHT
BETWEEN 55 AND 66 DEGREES WITH HIGHS WARMING WELL INTO THE 80S
SATURDAY AND EVEN THE LOWER 90S ACROSS THE WEST. IF YOU WANT TO
ENJOY PART OF THE WEEKEND AND BE OUTDOORS...SATURDAY IS YOUR BEST
BET.
SATURDAY NIGHT THROUGH SUNDAY EVENING IS EXPECTED TO BE AN ACTIVE
PERIOD WEATHER-WISE...AS LEAD SHORTWAVE ENERGY BEGINS NEGATIVELY
ROTATING THROUGH THE FOUR CORNERS AND OVER THE WESTERN HIGH
PLAINS BY SUNRISE SUNDAY. RAPID HEIGHT FALLS MOVING OUT OF THE
ROCKIES WILL HELP DEEPEN A SURFACE DRYLINE ACROSS THE SOUTH PLAINS
AND TEXAS PANHANDLE THROUGH SATURDAY EVENING. IT WILL LIKELY TAKE
UNTIL LATE AFTERNOON OR NEAR 00Z BEFORE A FEW DISCRETE STORMS
INITIATE FROM NORTHWEST OF ABILENE AND UP THROUGH CHILDRESS AND
SOUTHWEST OKLAHOMA...VERY FAST SSW FLOW STEERING THE MAJORITY OF
ACTIVITY TO THE NORTHEAST. THE DRYLINE SHOULD BEGIN TRANSVERSING
EAST THROUGH THE EVENING HOURS WITH ISOLATED TO SCATTERED STORMS
POSSIBLY ENTERING OUR FAR W/NW COUNTIES BEFORE MIDNIGHT. IN
ADDITION...SURFACE-BASED STORMS WILL REMAIN POSSIBLE MOST OF THE
EVENING WITH ALL MODES OF SEVERE WEATHER POSSIBLE WITH ANY
SUPERCELLS BEFORE AN INCREASING LLJ OVERNIGHT AND WAA HELP RE-
INTENSIFY THE CAPPING INVERSION WITH CONVECTION EXPECTED TO BE
ELEVATED OVERNIGHT AND THROUGH THE SUNRISE HOURS SUNDAY. STORM
CHANCES SHOULD BE HIGHEST ACROSS THE NORTHERN COUNTIES WHERE BULK OF
FORCING FROM ENHANCED ELEVATED WAA AND FASTER EASTWARD PROGRESSION
OF THE SURFACE DRYLINE WILL OCCUR. DESPITE THE ELEVATED NATURE OF
STORMS...VERY STEEP LAPSE RATES BETWEEN 850-650MB WILL ALLOW FOR
PLENTY OF MUCAPE IN THE HAIL GROWTH ZONE. HAVE LEFT SEVERE MENTION
IN FOR THE OVERNIGHT PERIOD FOR THE POTENTIAL OF SOME LARGER HAIL.
THE CHALLENGES CONTINUE AS WE MOVE THROUGH THE DAY SUNDAY AS THE
STRONG SHORTWAVE TROUGH CONTINUES TO NEGATIVELY TILT OVER CENTRAL
HIGH PLAINS. THE STRONG WEST- SOUTHWEST COMPONENT ATOP THE APPROACHING
SURFACE DRYLINE WILL HELP MOVE IT EAST FASTER ACROSS NORTH TEXAS
VERSUS FURTHER SOUTH OVER OUR CENTRAL TEXAS COUNTIES THROUGH EARLY
AFTERNOON. MODELS STILL SHOW A VARIANCE OF THE DRYLINE POSITION
SUNDAY AFTERNOON WITH AS FAR WEST AS I-35/35E...TO AS FAR EAST AS
I-45 UP THROUGH I-30. WITH THIS IN MIND...HAVE ORIENTED POPS NE-SW
ALONG THE DRYLINE WITH HIGHEST CHANCES FOR SEVERE SUPERCELL STORMS
OCCURRING MAINLY EAST OF A BONHAM-TERRELL-HEARNE LINE. THE VERY
WARM TEMPERATURES AND HIGH DEW PTS PRODUCING SBCAPE VALUES OF
2500-3500 J/KG EAST OF THE DRYLINE AND WESTERLY EFFECTIVE SHEAR
VALUES 30-35 KTS WITH SOUTHERLY 0-1KM SHEAR 20 KTS+...SURFACE-
BASED STORMS SHOULD ALLOW FOR ALL POSSIBLE MODES OF SEVERE WEATHER
INCLUDING A FEW TORNADOES. THE WINDOW FOR SEVERE WEATHER LOOKS TO
BE EARLY AFTERNOON THROUGH EARLY EVENING...WHEN BETTER FORCING
BOTH SURFACE AND ALOFT SHOULD SHIFT EAST OUT OF THE AREA TOWARD
THE MODERATE RISK AREA ACROSS THE ARKLATEX.
WINDY AND WARM CONDITIONS WILL LIKELY RAMP UP THE FIRE DANGER ACROSS
THE WESTERN TWO THIRDS OF THE AREA WITH MINIMUM HUMIDITY VALUES
FALLING BELOW 20 PERCENT. GREEN UP OF GRASSES AND LIGHTER WINDS ON
SUNDAY SHOULD KEEP THE FIRE DANGER ONLY AT ELEVATED LEVELS. WE
MAY HAVE TO WATCH FOR HIGH TO CRITICAL FIRE WEATHER CONDITIONS FOR
MONDAY AFTERNOON WITH MORE GUSTIER WEST WINDS.
&&
.LONG TERM/MON NIGHT AND BEYOND/...
THE FIRST OF A COUPLE OF LATE SEASON COLD FRONTS ARRIVES MONDAY
NIGHT WITH SLIGHTLY COOLER TEMPERATURES ON TUESDAY. IT APPEARS IT
WILL BE A RELATIVELY BENIGN WEEK FOR THE SOUTHERN PLAINS WITH THE
UPPER LOW OVER THE PLAINS BEING HELD UP BY SEMI OMEGA BLOCKING
UPPER HIGH OVER EASTERN CANADA. THE UPPER LOW WILL ONLY MIGRATE
SLOWLY NORTHEAST TOWARD THE GREAT LAKES THROUGH THE END OF THE
WEEK. THIS SHOULD ALLOW FOR PERIODIC FRONTAL PASSAGES AND KEEP A
NORTH COMPONENT TO THE WIND AND A DRY AIRMASS IN PLACE THROUGH
MUCH OF THE WEEK AND KEEP TEMPERATURES 5-10 DEGREES BELOW NORMALS.
IT APPEARS MOISTURE WILL BE TOO SHALLOW AND SCANT WITH A STRONG
SHORTWAVE ROTATING ACROSS TEXAS THURSDAY INTO FRIDAY AND HAVE LEFT
A DRY FORECAST FOR NOW ALL THE WAY INTO NEXT WEEKEND.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 61 86 69 90 61 / 0 5 40 40 5
WACO, TX 62 85 68 90 55 / 0 5 20 30 5
PARIS, TX 54 85 67 80 56 / 0 5 40 70 30
DENTON, TX 60 85 68 87 55 / 5 5 60 40 5
MCKINNEY, TX 58 85 68 87 56 / 0 5 50 50 10
DALLAS, TX 61 87 69 90 62 / 0 5 40 50 5
TERRELL, TX 58 85 68 84 54 / 0 5 30 50 10
CORSICANA, TX 60 84 68 85 57 / 0 5 20 50 10
TEMPLE, TX 63 86 69 89 57 / 0 10 20 30 5
MINERAL WELLS, TX 61 88 69 88 55 / 5 10 50 20 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1041 PM CDT SUN APR 27 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 238 PM CDT SUN APR 27 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW OCCLUDED LOW
PRESSURE SPINNING OVER WESTERN KANSAS. A WARM FRONT EXTENDS FROM
THIS LOW EASTWARD INTO THE OHIO VALLEY. NORTH OF THIS WARM
FRONT...MID-LEVEL THETAE ADVECTION AND FGEN IS CONTRIBUTING TO A
BAND OF LIGHT RAIN PROGRESSING NORTHWARD ACROSS THE FORECAST AREA
THIS AFTERNOON. SHOWERS ARE TRYING TO REDEVELOP SOUTH OF THIS RAIN
BAND OVER SOUTHWEST WISCONSIN...BUT COVERAGE IS SIGNIFICANTLY LESS
OVER EASTERN IOWA AND NORTHERN ILLINOIS. THEN A POTENT LINE OF
STORMS IS PROGRESSING NORTHEAST ACROSS IOWA AND MISSOURI. RAIN
CHANCES AND AMOUNTS ARE THE MAIN FORECAST CONCERN IN THE SHORT TERM.
TONIGHT...THE OCCLUDED CYCLONE OVER THE CENTRAL PLAINS WILL MOVE
VERY LITTLE TO THE NORTHEAST FROM CENTRAL KANSAS TO NORTHEAST
NEBRASKA WHILE HUDSON BAY HIGH PRESSURE REMAINS IN PLACE.
ANTICIPATING THAT ARCING BAND OF RAIN ASSOCIATED WITH MID-LEVEL
MOISTURE ADVECTION AND FGEN WILL HAVE WEAKENED AT THE START OF THE
EVENING AS IT MOVES INTO A DRIER AIRMASS...BUT COULD STILL BE SOME
SHOWERS HANGING ON ACROSS NORTHERN WISCONSIN AND WILL LEAVE A CHANCE
IN THE FORECAST. THEN ANTICIPATE THAT THERE WILL BE A BREAK OR
REDUCED COVERAGE OF PRECIP FOR A PERIOD THIS EVENING BEFORE THE LINE
OF CONVECTION OVER THE PLAINS PIVOTS AS IT MOVES NE INTO WISCONSIN.
THINK THIS LINE WILL MAKE IT INTO CENTRAL WISCONSIN AND THE SOUTHERN
FOX VALLEY LATE TONIGHT (THOUGH WILL NOT BE NEARLY AS INTENSE AS IT
STANDS CURRENTLY) DUE TO INCREASING 900-800MB MOISTURE TRANSPORT AND
FGEN. PRIOR TO THIS AREA OF RAIN ARRIVING...CANNOT RULE OUT SPOTTY
TO SCATTERED SHOWERS REDEVELOPING. BUT IN GENERAL...WILL HAVE THE
LOWEST CHANCE OF PRECIP EARLY IN THE EVENING AND THEN GRADUALLY
INCREASE CHANCES THROUGH THE NIGHT. LOWS SHOULD BE RELATIVELY
STEADY IN THE MIDDLE TO UPPER 30S.
MONDAY...THE ARCING BAND OF RAIN WILL SLOWLY LIFT NORTHEAST THROUGH
THE DAY BUT SHOULD BE GRADUALLY WEAKENING AS IT DOES SO. SOME
CONCERN THAT THE RAINS COULD BRING DOWN SOME BEEFY GUSTS FROM ALOFT
AS THE NAM IS DEPICTING WINDS UPWARDS OF 60 KTS ABOUT 2KFT ABOVE THE
SURFACE OVER CENTRAL WISCONSIN. WILL MENTION HIGHER GUSTS IN THE
HWO. DESPITE MID-LEVEL HEIGHT FALLS...INSTABILITY APPEARS TOO
MARGINAL FOR MUCH OF A THUNDER CHANCE. BUT WITH PWATS OVER AN INCH
AND THE SLOWLY FORWARD PROGRESSION...DECENT RAINS ARE LIKELY OVER
CENTRAL AND EAST-CENTRAL WISCONSIN OF A HALF INCH TO AN INCH.
NORTHERN AND NE WISCONSIN WILL BE RELATIVELY DRIER DUE TO THE DRY NE
LOW LEVEL FLOW BUT THAT AREA SHOULD SEE RAIN TOO. HIGHS ONLY IN THE
LOW TO MIDDLE 40S.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 238 PM CDT SUN APR 27 2014
PCPN TRENDS THROUGHOUT THE PERIOD...AND STRONG E-NE WINDS MONDAY
NIGHT INTO TUESDAY MORNING...ARE THE MAIN FCST CONCERNS.
AN UPPER LEVEL LOW WILL MOVE TOWARD THE UPPER MISSISSIPPI VALLEY
ON MONDAY NIGHT...REMAIN OVER THE WESTERN GREAT LAKES FROM TUESDAY
THROUGH THURSDAY...THEN WEAKEN AND GRADUALLY SHIFT NE ON THURSDAY
NIGHT AND FRIDAY. ALTHOUGH PCPN WILL BE IN THE FCST THROUGHOUT
THE PERIOD...THE BEST RAINFALL SHOULD OCCUR AS A STRONG S/W TROF
ROTATES THROUGH LATE MONDAY NIGHT INTO TUESDAY MORNING...AND AS
ANOTHER WAVE OR WEAK UPPER LOW AFFECTS NE/N WI LATE TUESDAY NIGHT
INTO WEDNESDAY. PCPN SHOULD BECOME MORE SCATTERED IN NATURE DURING
THE LATTER HALF OF THE WEEK. MOST OF THE PCPN SHOULD FALL AS RAIN...
ALTHOUGH A MIX OF RAIN/SNOW IS POSSIBLE OVER PARTS OF NC/FAR NE WI
LATE MON NGT/EARLY TUE...AND AGAIN LATE WED NGT/EARLY THU AND
LATE THU NGT/EARLY FRI. SIGNIFICANT RAINFALL AMOUNTS MAY CAUSE
SOME MINOR RIVER FLOODING DURING THE UPCOMING WORK WEEK.
A STRONG PRESSURE GRADIENT WILL SET UP BETWEEN A LARGE HUDSON BAY
HIGH AND LOW PRESSURE APPROACHING FROM THE CENTRAL PLAINS ON MON
NGT. WITH ENE WINDS OF 35-50 KTS ABOUT A THOUSAND FEET OFF THE
SFC...STRONG GUSTS OF 30 TO 40 MPH MAY OCCUR IN THE FAVORED
LOCATIONS...MAINLY CENTRAL WI AND THE FOX VALLEY. THE WINDS ARE
EXPECTED TO DECREASE AS AN INVERTED SFC TROF ARRIVES AND THE
GRADIENT WEAKENS TUESDAY AFTERNOON.
THE MAIN WEATHER FEATURE FOR NEXT WEEKEND IS A COLD FRONT THAT
IS PROGGED TO MOVE THROUGH THE REGION ON SUNDAY. THIS LOOKS
LIKE A FAIRLY DYNAMIC SYSTEM...SO POPS MAY NEED TO BE INCREASED
WITH SUBSEQUENT FCSTS.
TEMPERATURES WILL REMAIN WELL BELOW NORMAL...WITH HIGHS IN THE
40S AND LOWER 50S THROUGH MOST OF THE PERIOD.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1041 PM CDT SUN APR 27 2014
A LARGE UPPER LOW SYSTEM SLOWLY CHURNING ACROSS MID
SECTION OF THE COUNTRY THIS WEEK WILL CONTINUE TO LIFT BANDS OF
SHOWERS NORTH OVER THE STATE FOR MUCH OF THE WEEK. DRY AIR ON
EASTERLY WINDS WILL CONTINUE TO POUR INTO THE AREA TO KEEP CIGS
MAINLY AT VFR LEVELS FOR MOST OF TONIGHT INTO MONDAY. AS SHOWERS
BECOME MORE WIDESPREAD FROM SOUTHWEST TO NORTHEAST MONDAY...CIGS
WILL ALSO LOWER TO MVFR LEVELS FROM SOUTHWEST TO NORTHEAST.
COMPACT PRESSURE GRADIENT AHEAD OF THE LARGE SURFACE LOW OVER THE
CENTRAL PLAINS WILL ENSURE GUSTY WINDS AT THE SURFACE FOR A FEW
DAYS ALONG WITH LLWS CONDITIONS DUE TO 2000 FOOT WINDS WINDS UP TO
50 KTS THROUGH MONDAY.
&&
.HYDROLOGY...
ISSUED AT 238 PM CDT SUN APR 27 2014
RAINFALL TOTALS OF 1.5 INCHES OVER FAR NORTHERN WI...AND 1.5 TO 2.5
INCHES OVER THE SRN THREE-QUARTERS OF THE FCST AREA...ARE EXPECTED
DURING THE SUNDAY NGT THROUGH WEDNESDAY NGT PERIOD. THE RESULTING
RUNOFF COULD CAUSE SOME MINOR RIVER FLOODING...AS SEVERAL RIVERS
STILL REMAIN ABOVE BANKFULL. WILL CONTINUE TO MENTION THE RIVER
FLOODING THREAT IN A HYDROLOGIC OUTLOOK AND THE HAZARDOUS WEATHER
OUTLOOK.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......TDH
HYDROLOGY......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
830 PM CDT SUN APR 27 2014
.UPDATE...
THINGS HAVE QUIETED DOWN ACROSS THE AREA THIS EVENING...NOT THAT
IT EVER REALLY GOT LOUD. THE BIG STORMS TO OUR SOUTHWEST LATE THIS
AFTERNOON JUST COULDN/T SURVIVE UP IN THESE PARTS WITH A BOUNDARY
LAYER TEMP SITTING IN THE 40S WITH DEWPOINTS IN THE 30S. ALTHOUGH
THE BOUNDARY LAYER IS STABLE...JUST ABOVE IT THERE IS AMPLE
MOISTURE AND SOME HEAT RETURNING AS THE WARM CONVEYOR BELT LIFTS
UP THIS WAY. IT WILL BE WET ON AND OFF THROUGH THE NIGHT WITH A
FEW RUMBLES OF THUNDER POSSIBLE. THE MAIN MOISTURE AXIS SHOULD
LIFT UP HERE AFTER ABOUT 3-4AM WITH DECENT RAINFALL EXPECTED
DURING MONDAY MORNING. THIS IS JUST THE FIRST OF A FEW WAVES OF
RAINFALL OVER THE NEXT COUPLE OF DAYS.
&&
.AVIATION/06Z TAFS/...
LOOK FOR CONDITIONS TO STEADILY DETERIORATE OVERNIGHT AS
PERSISTENT RAIN FINALLY SATURATES UP THE BOUNDARY LAYER AND WE
EVENTUALLY GET INTO MVFR/IFR CIGS/VSBYS LATER TONIGHT AND THROUGH
THE REMAINDER OF THE TAF PERIOD. THE EASTERLY WINDS HAVE
DIMINISHED SOME DUE TO THE COLD BOUNDARY LAYER WHICH IS RAISING
CONCERN FOR LOW LEVEL WIND SHEAR. WILL INTRODUCE IT INTO THE TAFS
FOR THE INTIAL HOURS...UNTIL WE MIX OUT TOMORROW MORNING. WINDS AT
JUST 2KFT ARE BLOWING 50KTS WHILE AT THE SURFACE THEY ARE AROUND
15KTS.
&&
.PREV DISCUSSION... /ISSUED 336 PM CDT SUN APR 27 2014/
SHORT TERM...
TONIGHT AND MONDAY...FORECAST CONFIDENCE IS HIGH.
SCATTERED SHOWERS CONTINUE TO DEVELOP ACROSS WESTERN PORTIONS OF THE
AREA...WITH MORE SHOWERS AND STORMS DEVELOPING INTO WEST CENTRAL TO
NORTH CENTRAL ILLINOIS. THESE CONTINUE TO DEVELOP ON THE 850 MB LOW
LEVEL JET AND FOCUSED LOW LEVEL WARM AIR ADVECTION. ADDED POPS
THROUGH THE REST OF THE AFTERNOON TO ACCOUNT FOR THE CURRENT SHOWERS
OVER THE WESTERN COUNTIES. THE ACTIVITY TO OUR SOUTH MAY MOVE INTO
THE SOUTHERN PORTIONS OF THE AREA BY 00Z MONDAY PER HRRR AND 4KM
WRF/NMM MODELS. ELEVATED CAPES ARE A FEW HUNDRED J/KG...SO COULD
HEAR CLAPS OF THUNDER AS WELL. THUS...KEPT THE POPS GOING INTO THE
EARLY EVENING IN THE WEST AND SOUTHWEST COUNTIES. MAY HAVE TO GO
HIGHER WITH POPS IF THIS ACTIVITY REMAINS ORGANIZED.
HRRR AND 4KM WRF/NMM MODELS BRINGING MAIN WARM CONVEYOR BELT RAIN
INTO THE AREA AT SLIGHTLY DIFFERENT TIMES...THE HRRR NOT UNTIL AFTER
MIDNIGHT AND THE WRF/NMM AFTER 03Z MONDAY. USED THE 4KM WRF/NMM FOR
TIMING...AS IT SEEMS TO HAVE A DECENT HANDLE ON CURRENT CONVECTION
AND PRECIPITATION. HIGH POPS THEN LINGER LATER TONIGHT INTO
MONDAY...WITH WARM CONVEYOR BELT RAIN OVER THE AREA. ISOLATED
THUNDER KEPT WITH WEAK ELEVATED CAPE. COULD SEE LIGHTER RAIN IN THE
AFTERNOON IN THE WESTERN COUNTIES...AS BEST UPWARD VERTICAL MOTION
SHIFTS NORTH OF THAT AREA FOR A TIME. QPF TONIGHT INTO MONDAY NIGHT
IS FORECAST BETWEEN 1.75 AND AROUND 2.00 INCHES.
GUSTY EAST WINDS WILL LINGER TONIGHT AND MONDAY...WITH TIGHT
PRESSURE GRADIENT ACROSS THE AREA. GUSTS TO 30 TO 33 KNOTS ARE
EXPECTED AT TIMES. MAY SEE A FEW GUSTS AND SUSTAINED WINDS GET NEAR
WIND ADVISORY LEVELS...MAINLY IN THE WEST...WITH STRONG LOW LEVEL
WINDS JUST OFF THE SURFACE. MOST GUSTS WILL REMAIN BELOW CRITERIA.
TEMPERATURES WILL REMAIN COOL WITH THE RAIN AND GUSTY EAST WINDS.
MONDAY NIGHT THROUGH WEDNESDAY...FORECAST CONFIDENCE MEDIUM.
THE OCCLUDED LOW WILL BE OVER FAR ERN NE EARLY MONDAY EVENING AND
SLOWLY MOVE EWD. THE UPPER TROUGH AXIS EXTENDING FROM THE
OCCLUSION WILL PIVOT NWD THROUGH WI MON NT...BRINGING ANOTHER
ROUND OF WIDESPREAD MODERATE RAINFALL. THE OCCLUDED FRONT WILL
MAKE IT TO THE IL/WI BORDER BY 12Z TUE. THE SFC LOW WILL THEN
BECOME A BROAD N-S TROUGH OF LOW PRESSURE FROM SRN WI THROUGH IL.
THIS WILL BRING THE OCCLUDED FRONT NWD INTO CENTRAL WI...THUS
MILDER TEMPS ARE EXPECTED FOR TUE BUT SHOWERY CONDITIONS WILL
CONTINUE ALONG WITH CHANCES OF TSTORMS WITH THE WARMER AND MORE
UNSTABLE CONDITIONS.
THE LARGE UPPER LOW OVER THE UPPER MS RIVER VALLEY WILL THEN AID
IN ANOTHER ROUND OF CYCLOGENESIS OVER MI TUE NT BUT THAT WILL ALSO
QUICKLY OCCLUDE WITH THE LOW OVER WI OR MI FOR WED. THE LARGE
UPPER LOW ALOFT WILL ENSURE SHOWERY CONDITIONS CONTINUING THROUGH
THIS PERIOD. AROUND 2 INCHES OF RAIN IS FORECAST FROM TNT THROUGH
MON NT WITH SHOWERY CONDITIONS EXPECTED AFTERWARD. REISSUED THE
HYDROLOGIC OUTLOOK WITH MANY RIVERS EXPECTED TO BE AT ABOVE
NORMAL FLOWS WITH A FEW REACHING MINOR FLOOD STAGE.
LONG TERM...
THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM
THE LARGE OCCLUDED LOW WILL TAKE UNTIL ABOUT SAT TO MOVE AWAY WITH
A WEAK RIDGE OF HIGH PRESSURE SHIFTING EWD ACROSS THE REGION.
ANOTHER STRONG SHORTWAVE TROUGH AND SFC WAVE WITH THE POLAR JET
STREAM WILL THEN QUICKLY MOVE EWD ACROSS WI FOR SUN. THUS THE RAIN
CHANCES WILL CONTINUE THROUGH THE EXTENDED AS WELL. BELOW NORMAL
TEMPS TO PREVAIL.
AVIATION/00Z TAFS/...
SCATTERED SHOWERS AND AN ISOLATED STORM ARE POSSIBLE THROUGH EARLY
THIS EVENING...ESPECIALLY AT MADISON. COULD SEE MVFR VISIBILITIES IF
ANY OF THESE GO OVER THE AIRPORT. FOR NOW...MAY PUT VICINITY SHOWERS
IN TAF AT MADISON.
MAIN ROUND OF MODERATE RAIN/SHOWERS WILL MOVE NORTHEAST INTO TAF
SITES THIS EVENING...BY 03Z MONDAY AT MADISON AND 06Z MONDAY AT THE
EASTERN SITES. THE RAIN WILL THEN LINGER LATER TONIGHT AND MONDAY.
MVFR CEILINGS AND VISIBILITIES ARE EXPECTED DURING THIS TIME...WITH
IFR VISIBILITIES POSSIBLE IN HEAVIER RAIN. ISOLATED THUNDERSTORMS
ARE POSSIBLE...BUT WILL LEAVE MENTION OUT OF TAFS FOR NOW.
GUSTY EAST WINDS WILL LINGER TONIGHT AND MONDAY...AS LOW PRESSURE
SLOWLY MOVES TOWARD THE REGION FROM THE WEST. SOME GUSTS TO 30 KNOTS
ARE EXPECTED. SOME POTENTIAL FOR LOW LEVEL WIND SHEAR TONIGHT INTO
EARLY MONDAY MORNING...AS EASTERLY 1500 FOOT WINDS APPROACHING 50 TO
55 KNOTS. STILL FEEL THAT SUSTAINED WINDS AND GUSTS WILL BE STRONG
ENOUGH TO PREVENT MENTION IN TAFS FOR NOW.
MARINE...
SMALL CRAFT ADVISORY CONTINUES FOR THE NEARSHORE WATERS OF LAKE
MICHIGAN UNTIL LATER TUESDAY AFTERNOON. WINDS ARE EXPECTED TO RAMP
BACK UPWARDS BY EARLY EVENING...WITH TIGHT PRESSURE GRADIENT WITH
APPROACHING LOW PRESSURE FROM THE WEST. GUSTY EAST WINDS ARE THEN
EXPECTED TO LINGER INTO MONDAY. GUSTS TO 30 KNOTS ARE EXPECTED
TONIGHT INTO MONDAY...WITH A FEW TO 35 KNOTS. NOT EXPECTING GALE
FORCE GUSTS TO BE FREQUENT ENOUGH FOR A GALE WARNING AT THIS TIME.
WINDS WILL THEN SLOWLY WEAKEN MONDAY NIGHT AND TUESDAY.
HIGH WAVES ARE EXPECTED WITH THE GUSTY ONSHORE WINDS TONIGHT INTO
TUESDAY AFTERNOON. THEY SHOULD BUILD TO 6 TO 10 FEET TONIGHT INTO
MONDAY...WITH SOME 8 TO 12 FOOT WAVES POSSIBLE SOUTH OF NORTH POINT
LIGHTHOUSE. WAVES WILL SLOWLY SUBSIDE MONDAY NIGHT INTO
TUESDAY...FALLING BELOW 4 FEET BY LATE TUESDAY AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM CDT TUESDAY FOR LMZ643>646.
&&
$$
UPDATE...DAVIS
TONIGHT/MONDAY AND AVIATION/MARINE...WOOD
MONDAY NIGHT THROUGH SUNDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
605 PM CDT SUN APR 27 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 313 PM CDT SUN APR 27 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED TROUGHING ALONG THE BRITISH COLUMBIA COAST...A POTENT
NEGATIVELY TILTED TROUGH AND UPPER LOW OVER KANSAS...AND A STRONG
UPPER LEVEL RIDGE FROM THE SOUTHEASTERN U.S. INTO MANITOBA. IN-
BETWEEN THE UPPER LOW AND RIDGE...PROFILER AND VWP DATA SHOWED A 30-
50 KT JET CORE AT 850MB FROM THE WESTERN GULF OF MEXICO NORTHWARD
THROUGH MINNESOTA RAPIDLY TRANSPORTING MOISTURE NORTHWARD. GOES
PRECIPITABLE WATER IMAGERY DEPICTED VALUES OF 1-1.5 INCHES
ENCOMPASSING MUCH OF IOWA SOUTHWARD INTO LOUISIANA...WITH LOWER
VALUES OF LESS THAN 0.5 INCH OVER MUCH OF KANSAS INTO WESTERN
OKLAHOMA WHERE A DRY SLOT EXISTS. ALONG AND JUST EAST/NORTHEAST OF
THIS GRADIENT OF PRECIPITABLE WATER...NUMEROUS SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED FROM CENTRAL IOWA AND MISSOURI. SOME OF
THESE STORMS ARE INTENSE TOO...MOSTLY SOUTH OF I-80 WHERE 750-1500
J/KG OF MLCAPE EXISTS PER RAP ANALYSIS. FARTHER NORTHEAST... SHOWERS
AND EMBEDDED THUNDERSTORMS THAT AFFECTED THE FORECAST AREA THIS
MORNING HAVE MOSTLY LIFTED NORTH OF I-90. THESE ARE ASSOCIATED WITH
MID-LEVEL FRONTOGENESIS AND RIGHT ENTRANCE REGION OF AN UPPER JET
OVER LAKE SUPERIOR. LASTLY...A TIGHT PRESSURE GRADIENT IN PLACE
COMBINED WITH THAT AFOREMENTIONED STRONG 850MB JET CORE HAS LED TO
BRISK EAST WINDS. THESE HAVE BEEN SUSTAINED AT 15-35 MPH WITH GUSTS
OF 25-45 MPH...STRONGEST WEST OF THE MS RIVER.
VERY GOOD MODEL AGREEMENT CONTINUES THAT THE BAND OF SHOWERS AND
THUNDERSTORMS TO OUR SOUTHWEST WILL LIFT NORTHEAST THROUGH THE
FORECAST AREA TONIGHT INTO MONDAY MORNING. THIS IS ALL IN RESPONSE
TOO THE UPPER LOW AND ASSOCIATED SHORTWAVE TROUGH LIFTING INTO
NEBRASKA AND IOWA BY 18Z MONDAY. THE QUESTION IS AMOUNT WHICH HAS
BIG IMPACTS ON POTENTIAL FOR RIVER FLOODING. THE AMOUNT HAS STRONG
TIES TO EVOLUTION OF CONVECTION OVER WESTERN MISSOURI AND SOUTHWEST
IOWA IN WHICH THERE ARE THREE SCENARIOS...
1. THE CONVECTION TURNS INTO A FORWARD PROPAGATING SQUALL
LINE...ESSENTIALLY LIMITING HEAVIER RAINFALL INTO THE FORECAST AREA.
THIS SQUALL LINE FALLS APART OVER ILLINOIS LATE THIS EVENING AS IT
RUNS INTO MORE STABLE AIR.
2. THE CONVECTION WEAKENS AS IT PUSHES EAST...RESULTING IN A
PERSISTENT WARM CONVEYOR BELT OF SHOWERS AND EMBEDDED THUNDERSTORMS.
THE TRAINING FACTOR COMES INTO PLAY...ALLOWING FOR HEAVIER
RAINFALL...ESPECIALLY ACROSS NORTHEAST IOWA THIS EVENING.
3. THE CONVECTION WEAKENS AS IT PUSHES EAST...AND ESSENTIALLY MUCH
OF THE SHOWER ACTIVITY FALLS APART BY 04Z.
ALL THREE IDEAS ARE CERTAINLY PLAUSIBLE...BUT IT IS SERIOUSLY WORTH
NOTING THE CONVECTION HAS BEEN OUTRUNNING MOST MODELS. THE ONLY
MODEL THAT HAS BEEN HANDLING THIS WELL IS THE 00Z SPC WRF-NMM...
WHICH IS SCENARIO NUMBER 3 ABOVE. THEREFORE...HAVE TRIED TO LEAN
MORE TOWARDS THAT FOR PRECIPITATION CHANCES AND QPF. STILL...THE
FORECAST MAY BE OVERDONE...ESPECIALLY WITH PRECIPITATION CHANCES IN
THAT 04-09Z TIME FRAME. WOULD THINK THAT PERSISTENT 850MB MOISTURE
TRANSPORT WOULD AT LEAST CONTINUE SOME SHOWER ACTIVITY AND NOT
COMPLETELY END...THUS THE HIGHER CHANCES IN THE FORECAST. ALL THREE
SCENARIOS ABOVE REGENERATE SHOWERS AND EMBEDDED THUNDERSTORM
ACTIVITY OVER THE FORECAST AREA AROUND 09Z...ASSOCIATED WITH DPVA
FROM THE APPROACHING NEGATIVELY TILTED SHORTWAVE TROUGH. SEE
HYDROLOGY SECTION BELOW FOR IMPACT ON RIVERS.
AFTER THE RAIN AND CONVECTION TONIGHT/MONDAY MORNING...ATTENTION
THEN TURNS TO A WARM FRONT PROGGED TO LIFT THROUGH IOWA. THE
MAJORITY OF MODELS KEEP IT JUST SOUTH OF THE FORECAST AREA...EITHER
ALONG OR SOUTH OF US-20. THE NORTHWARD PROGRESS OF THE FRONT HINGES
QUITE A BIT ON MORNING PRECIPITATION. CONVECTION LOOKS LIKELY TO
FIRE ALONG AND SOUTH OF THIS FRONTAL BOUNDARY. SOME OF THIS
CONVECTION COULD CREEP INTO FAR SOUTHERN PORTIONS OF THE FORECAST
AREA IN THE LATE AFTERNOON...AND POSSIBLY BE SEVERE. NOTE THAT A
VERY TIGHT GRADIENT OF INSTABILITY WILL EXIST...SO ANY SEVERE THREAT
SHOULD BE CONFINED TO FAYETTE EAST TO GRANT COUNTIES.
LASTLY...REGARDING THE WIND ADVISORY...AS EXPECTED THE CONDITIONS
HAVE BEEN MARGINAL. WILL KEEP IT GOING THROUGH 9 PM AS SUSTAINED
SPEEDS CONTINUE TO PULSE UP AND DOWN TO 30 MPH. THERE IS A
POSSIBILITY THE ADVISORY MAY NEED TO BE EXTENDED TO MIDNIGHT SEEING
SOME LAV GUIDANCE HOLDING RST...TOB AND OLZ BETWEEN 25-30 KT TO
06Z.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 313 PM CDT SUN APR 27 2014
THE UPPER LOW OVER NEBRASKA ON MONDAY IS THE MAIN FEATURE OF FOCUS
FOR THE LONG TERM PERIOD. MODELS CONTINUE TO SUGGEST THIS UPPER LOW
WILL PLAGUE THE FORECAST AREA THROUGH AT LEAST THURSDAY AS IT SLOWLY
TRACKS NORTHEAST INTO UPPER MICHIGAN. HEADING INTO THE WEEKEND...THE
UPPER PATTERN REMAINS COOL AS RIDGING HOLDS IN PLACE OVER THE
WESTERN U.S. INTO WESTERN CANADA...CAUSING TROUGHING TO PERSIST OVER
THE GREAT LAKES REGION. THIS IS VERY WELL AGREED UPON BY THE
27.06Z/12Z GFS AND 27.00Z/12Z ECMWF.
FOR MONDAY NIGHT INTO TUESDAY. CONDITIONS REMAIN FAVORABLE FOR A
BAND OF SHOWERS TO FORM JUST NORTH OF THAT WARM FRONTAL BOUNDARY IN
IOWA MONDAY EVENING...ASSOCIATED WITH DPVA FORCING AND 800-900MB
FRONTOGENESIS. THIS BAND...AFFECTING LOCATIONS SOUTH OF I-90 MONDAY
EVENING...SHOULD TRANSLATE NORTHWARD TO ALONG AND NORTH OF I-90 BY
TUESDAY MORNING...WITH PRECIPITATION POSSIBLY TAILING OFF TO THE
SOUTH. THEN WE GET INTO A COLD CONVEYOR BELT SCENARIO FOR TUESDAY
AFTERNOON OVER NORTHWESTERN SECTIONS OF THE FORECAST AREA. OTHER
SHOWERS SHOULD POP UP ELSEWHERE UNDER THE UPPER LOW DUE TO MID LEVEL
COLD AIR. THERE COULD EVEN BE SOME THUNDER WITH THEM...BUT
CONFIDENCE TOO LOW TO INCLUDE RIGHT NOW.
FROM TUESDAY NIGHT THROUGH THURSDAY...THE FORECAST AREA PRETTY MUCH
SITS IN A GRADUALLY WEAKENING COLD CONVEYOR BELT OF SHOWERS...WITH
PERHAPS SOME DIURNAL ENHANCEMENT THAT COULD INCREASE COVERAGE.
GIVEN HIGH CONFIDENCE OF PRECIPITATION AROUND...HAVE USED COVERAGE
VERBIAGE. WITH PLENTY OF CLOUDS AND SHOWER ACTIVITY AROUND...
COMBINED WITH 850MB TEMPS ONLY AROUND 0C PLUS OR MINUS 2
C...EXPECT CHILLY TEMPERATURES.
CHANCES OF PRECIPITATION CONTINUE OFF AND ON FOR THURSDAY NIGHT
RIGHT THROUGH SUNDAY AS SHORTWAVES DROP SOUTHEAST THROUGH THE GREAT
LAKES TROUGHING. SOME SIGNAL THAT A SHORTWAVE TROUGH ON SUNDAY
MIGHT BE MORE POTENT...SO CHANCES MAY NEED TO BE RAISED BEYOND THE
CURRENT FORECAST OF A MODEL CONSENSUS. AS IT STANDS RIGHT NOW THE
AIR IS NOT COLD ENOUGH FOR SNOW...BUT ITS NOT FAR OFF. 850MB
STANDARDIZED ANOMALIES GENERALLY HOLD AROUND 1 STANDARD DEVIATION
BELOW NORMAL...OR BETWEEN -4C AND 0C. NEEDLESS TO SAY...BELOW
NORMAL TEMPERATURES CONTINUE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 605 PM CDT SUN APR 27 2014
CHALLENGING FORECAST AS THERE WILL BE PERIODS OF RA/TSRA...AND PIN
POINTING WHERE THE BREAKS IN THE PCPN WILL BE IS PROBLEMATIC. IN
ADDITION...WINDS WILL STAY STRONG AND GUSTY THROUGH TUESDAY AS TIGHT
PRESSURE GRADIENT PERSISTS FOR MUCH OF THE UPPER MISSISSIPPI RIVER
VALLEY - WITH THE RESPONSIBLE SFC LOW JUST TO THE SOUTH. WINDS WILL
ALSO REMAIN STRONG JUST OFF THE SFC...50-60 KTS AROUND 2 KFT. LLWS
WILL BE A FACTOR FOR KLSE INTO MONDAY AFTERNOON.
BACK TO THE PCPN - FIRST BAND OF SHRA/TS GOING TO TRACK NORTHWARD
ACROSS KRST/KLSE THRU 02-03Z. SHOULD SEE A BREAK IN THE PCPN AFTER
THAT...ALTHOUGH ENOUGH UNCERTAINTY THAT WILL HOLD A VCSH FOR
STRAGGLERS THAT COULD LINGER.
ANOTHER BATCH OF SHRA COULD DEVELOP ON THE NOSE OF AN INCREASING LOW
LEVEL JET TOWARD 06Z. A MORE SIGNIFICANT SWATH OF THE WIDESPREAD
SHRA/TS WILL RETURN NEAR 12Z MON AS AN UPPER LEVEL SHORTWAVE TROUGH
SPINS NORTHEAST OUT OF THE SOUTHERN PLAINS. SHOULD MAKE FOR A SOGGY
MORNING WITH MVFR VSBYS. ANTICIPATING CIGS IN THE IFR/MVFR RANGE BY
THIS TIME.
MODEL TRENDS WOULD FAVOR LIFTING THIS NORTH OF THE TAF SITES BY 18-
20Z...BRINGING ANOTHER MOSTLY DRY PERIOD FOR THE AFTERNOON.
HOWEVER...ANOTHER ROUND OF PCPN APPEARS LIKELY AS SHRA/TS FIRE UP
ALONG A WARM FRONT JUST TO THE SOUTH LATE AFTERNOON/EVENING...WHICH
COULD PUSH NORTH.
BOTTOM-LINE...AN EXTENDED PERIOD OF WET WEATHER WITH IFR/MVFR
IMPLICATIONS FOR CIGS AND VSBYS. SOME THUNDER WILL BE POSSIBLE.
WINDS ARE GOING TO STAY STRONG...MOSTLY EAST-NORTHEAST...AND LLWS
WILL REMAIN A CONCERN AT KLSE INTO MON AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 313 PM CDT SUN APR 27 2014
PRECIPITATION FORECASTS REMAIN VERY UNCERTAIN FOR TONIGHT AS
SHOWERS AND EMBEDDED THUNDERSTORMS OVER CENTRAL IOWA ARE MOVING
FASTER THAN MOST MODELS. IN FACT...THE ONE MODEL THAT IS HANDLING
THE PRECIPITATION WELL SUGGESTS WE COULD HAVE A BREAK OF 6 HOURS
OF NO PRECIPITATION TONIGHT AFTER THEY PASS. ADDITIONALLY...THE
CONVECTION TO THE SOUTH MAY END UP INGESTING MORE OF THE
MOISTURE...LIMITING HEAVIER RAINFALL OVER THE FORECAST AREA. THIS
SCENARIO IS LOOKING MORE LIKELY FOR TONIGHT. BETTER CONFIDENCE
FOR MUCH OF THE AREA TO SEE ANYWHERE FROM 1/4 TO 1 INCH OF RAIN ON
MONDAY...WITH ANOTHER 1/2 TO 1 INCH FROM MONDAY NIGHT INTO
TUESDAY.
IN SUMMARY...BASED ON RFC FORECAST DATA...CONFIDENCE WAS ONLY HIGH
ENOUGH TO PUT A FLOOD WATCH ON THE TURKEY RIVER. SHOULD AROUND 1
INCH MATERIALIZE OVER THE BASIN THIS EVENING...THE WATCH WILL NEED
TO BE UPGRADED. ELSEWHERE...HAVE CONTINUED THE ESF. THERE ARE SOME
SIGNALS THAT HEAVIER QPF COULD FALL OVER WISCONSIN. SHOULD THIS
MATERIALIZE...MORE FLOOD WATCHES FOR AREA RIVERS MAY BE REQUIRED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MNZ086-087-094-095.
IA...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR IAZ008>010-018-019-
029.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
HYDROLOGY....AJ
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 251 PM CDT SAT APR 26 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE RIDGE
AXIS EXTENDING SOUTHWARD FROM A HUDSON BAY HIGH AND BISECTING
WISCONSIN EARLY THIS AFTERNOON. EAST OF THIS RIDGE AXIS...NORTHEAST
WINDS HAVE BEEN ADVECTING A LOW STRATUS DECK OVER MUCH OF
NORTH-CENTRAL AND NORTHEAST WISCONSIN. TEMPS HAVE BEEN HELD BACK
DUE TO THESE CLOUDS AND RANGE THROUGH THE 40S. LOOKING OUT TO THE
WEST...MID AND HIGH CLOUDS ARE SPILLING OVER A SHARP MID-LEVEL RIDGE
AXIS OVER THE NORTHERN PLAINS. THIS IS AHEAD OF A DEEP TROUGH
MOVING ACROSS THE WESTERN CONUS. ALSO TO THE EAST OF THIS
TROUGH...A SURFACE WARM FRONT IS SHIFTING NORTHWARD OVER THE CENTRAL
PLAINS WITH RETURN FLOWING INCREASING. AS THIS WARM FRONT LIFTS
NORTH OVER THE NEXT 24 HOURS...LIGHT PRECIP CHANCES ARE THE MAIN
FORECAST CONCERN.
TONIGHT...HUDSON BAY HIGH RIDGE AXIS WILL SHIFT FROM THE CENTRAL TO
THE EASTERN GREAT LAKES WHILE LOW PRESSURE EMERGES INTO THE CENTRAL
PLAINS. AHEAD OF THE LOW...MID AND HIGH CLOUDS WILL BE PUSHING
ACROSS THE STATE THIS EVENING BUT DRY NORTHEAST TO EAST WINDS WILL
KEEP THE AREA DRY. BY LATE TONIGHT THOUGH...40-50 KTS OF FLOW WILL
RIDE OVER THE MID-LEVEL THERMAL GRADIENT OVER THE NORTHERN
MISSISSIPPI VALLEY. THIS WILL CAUSE CLOUDS TO LOWER OVER CENTRAL
AND EAST-CENTRAL WISCONSIN AND VARIOUS MODELS BRING IN LIGHT PRECIP
INTO THE AREA BY 09Z. BECAUSE OF THE DRY EAST FLOW...THINK THIS IS
TOO AGGRESSIVE AND HAVE BACKED OFF PRECIP CHANCES A LITTLE AFTER
MIDNIGHT. MAY HAVE ENOUGH SATURATION FOR LIGHT RAIN BETWEEN 09-12Z
SO HAVE KEPT POPS IN THE HIGH CHANCE RANGE BUT STILL THINK THERE IS
POTENTIAL FOR THE DRY AIR TO WIN OUT. THE EAST WINDS WILL BE BREEZY
TONIGHT...WHICH WILL MAKE IT FEEL BLUSTERY AND DAMP. LOWS RANGING
FROM THE UPPER 20S NORTH TO UPPER 30S SOUTH.
SUNDAY...THE LOW PRESSURE SYSTEM WILL MOVE VERY LITTLE EASTWARD OVER
THE CENTRAL PLAINS...BUT THE RETURN FLOW WILL PUSH NORTHEAST ACROSS
THE STATE OVER THE COURSE OF THE DAY. AS THIS OCCURS...THE DRY
AIR WILL LOSE ITS INFLUENCE GRADUALLY...AND PRECIP CHANCES WILL
INCREASE OVER CENTRAL AND EAST-CENTRAL WISCONSIN. THE RAIN SHOULD
REMAIN LIGHT...BUT INCREASING MID-LEVEL FGEN COMBINED WITH PWATS
OVER AN INCH SUPPORT LIKELY POPS OVER CENTRAL WISCONSIN AND THE
SOUTHERN FOX VALLEY DURING THE AFTERNOON. TEMPS ARE DIFFICULT
DEPENDING UPON THE COVERAGE OF RAIN OVER SOUTHERN WISCONSIN...AND
THE LACK OF LOW CLOUDS OVER NORTHEAST WISCONSIN. WILL GO WITH
FAIRLY UNIFORM TEMPS RANGING FROM THE UPPER 40S TO LOWER 50S.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 251 PM CDT SAT APR 26 2014
PCPN TRENDS THROUGHOUT THE PERIOD...AND STRONG E-NE WINDS EARLY
NEXT WEEK...ARE THE MAIN FCST CONCERNS.
AN UPPER LEVEL RIDGE WILL SHIFT NORTHEAST SUNDAY NIGHT AND
MONDAY...AS AN UPPER LEVEL LOW MOVES INTO SOUTH DAKOTA/NEBRASKA.
THIS WILL CAUSE PCPN TO SLOWLY SHIFT NE ACROSS THE FORECAST
AREA...ALTHOUGH ITS PROGRESS WILL BE SLOWED ACROSS FAR N/NE
WI...DUE TO DRY AIR FEEDING OUT OF A STRONG HUDSON BAY HIGH. HAVE
ADJUSTED POPS/QPF TO ACCOUNT FOR THE DRY AIR. FARTHER
SOUTH...ACROSS C/EC WI...QPF AMOUNTS WILL PROBABLY EXCEED AN INCH
FROM LATE SUNDAY NIGHT THROUGH MONDAY. A STRONG PRESSURE GERADIENT
WILL SET UP BETWEEN THE HUDSON BAY HIGH AND LOW PRESSURE
APPROACHING FROM THE NORTHERN PLAINS. EAST WINDS OF 15 TO 25
MPH...WITH GUSTS TO 30 TO 35 MPH...CAN BE EXPECTED ACROSS THE
REGION. STRONG NE WINDS (GUSTING TO 35 TO 40 MPH) ARE ALSO
POSSIBLE OVER THE FOX VALLEY MONDAY NIGHT INTO TUESDAY.
THE UPPER LEVEL LOW IS EXPECTED TO GRADUALLY SHIFT NE...REMAIN
OVER THE WESTERN GREAT LAKES FROM TUESDAY THROUGH THURSDAY...THEN
WEAKEN INTO AN OPEN TROF AND SHIFT NE INTO CANADA BY FRIDAY.
ALTHOUGH PCPN WILL BE IN THE FCST THROUGHOUT THE PERIOD...THE BEST
CHANCES SHOULD OCCUR AS STRONG S/W TROFS ROTATE THROUGH LATE
MONDAY NIGHT INTO TUESDAY MORNING...AND OVER NORTHERN WI LATE
TUESDAY NIGHT INTO WEDNESDAY. PCPN SHOULD BECOME MORE SCATTERED IN
NATURE DURING THE LATTER HALF OF THE WEEK.
OVERALL...MOST OF THE PCPN SHOULD FALL AS RAIN...ALTHOUGH A MIX
OF RAIN/SNOW IS POSSIBLE OVER PARTS OF NC/FAR NE WI LATE MONDAY
NIGHT AND EARLY TUESDAY...AND AT TIMES FROM WEDNESDAY NIGHT
THROUGH FRIDAY.
TEMPERATURES WILL REMAIN WELL BELOW NORMAL...WITH HIGHS IN THE
40S AND LOWER 50S...THROUGH MIOST OF THE PERIOD. SOME MODERATION
IS EXPECTED LATE IN THE WEEK AS THE UPPER LOW SHIFTS OUT OF THE
REGION.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1225 PM CDT SAT APR 26 2014
SCATTERED TO BROKEN MVFR CLOUDS ACROSS THE NORTHEAST
HALF OF WISCONSIN WILL LIFT TO MVFR BY MIDDAY...BUT WILL TAKE UNTIL
MID TO LATE AFTERNOON TO DISSIPATE. MID AND HIGH CLOUDS WILL THEN
ARRIVE LATER THIS AFTERNOON AND LOWER THROUGH THE EVENING AHEAD OF
THE NEXT STORM SYSTEM. MODELS TRY TO BRING LIGHT RAIN INTO CENTRAL
WISCONSIN AFTER MIDNIGHT TONIGHT...BUT THINKING DRY EAST FLOW WILL
DELAY THIS ARRIVAL OF PRECIP UNTIL AT LEAST SUNDAY MORNING.
UNCERTAINTY IS HIGH ENOUGH TO JUST INDICATE VCSH IN THE TAFS FOR
NOW. CEILINGS AND VISIBILITIES SHOULD REMAIN RELATIVELY HIGH EVEN
IF LIGHT RAIN DOES MOVE IN. BETTER CHANCES OF LIGHT RAIN WILL OCCUR
SUNDAY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 251 PM CDT SAT APR 26 2014
RAINFALL TOTAL OF 1.5 TO 2.5 INCHES ARE EXPECTED ACROSS
THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA FROM SUNDAY NIGHT THROUGH
WEDNESDAY. THIS COULD RESULT IN SOME MINOR RIVER FLOODING...AS SEVERAL
RIVERS STILL REMAIN ABOVE BANKFULL. PLAN TO ISSUE AN ESF AND MENTION
FLOODING CONCERNS IN THE HWO.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
HYDROLOGY......KIECKBUSCH
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1210 PM CDT SAT APR 26 2014
.UPDATE...AREA OF LOW CLOUDS HAVE MOVED SOUTHWESTWARD INTO THE
NORTHEAST COUNTIES THIS MORNING AND HAVE LINGERED. THE
SOUTHWESTWARD ADVANCE SEEMS TO HAVE STOPPED FOR THE MOMENT...AS
DAYTIME HEATING ERODES THE LEADING EDGE OF THIS CLOUD BAND.
COULD STILL SEE THIS BAND SLIDE A BIT FURTHER SOUTHWEST INTO THE
AREA INTO THE AFTERNOON HOURS. THESE CLOUDS SHOULD GRADUALLY
BECOME MORE SCATTERED TO BROKEN BY THE LATE AFTERNOON HOURS...WITH
DAYTIME HEATING. MIDDLE TO HIGH CLOUDS SHOULD MOVE EAST INTO THE
AREA THIS AFTERNOON AS WELL.
NORTHEAST WINDS WITH THE CLOUDS SHOULD KEEP HIGHS IN THE MID 40S
IN THE CLOUDY AREAS THIS AFTERNOON. MID 40S WILL ALSO BE FOUND
NEAR LAKE MICHIGAN WITH THE ONSHORE WINDS. HIGHS ELSEWHERE SHOULD
RISE INTO THE 50S...NEAR 60 IN LAFAYETTE COUNTY.
&&
.AVIATION/18Z TAFS/...AREA OF MVFR CEILINGS MAY AFFECT TAF SITES
THROUGH THE MID AFTERNOON HOURS. HOWEVER...CONFIDENCE IS LOW WITH
HOW FAR SOUTHWEST THEY WILL MOVE...SO WILL LEAVE FEW TO SCATTERED
IN TAFS FOR NOW. NORTHEAST WINDS WILL BECOME EAST THIS AFTERNOON
AT MADISON...WITH NORTHEAST WINDS AT THE EASTERN SITES. SHOULD SEE
GUSTS TO 18 KNOTS AT TIMES THIS AFTERNOON.
WINDS WILL VEER EAST TONIGHT AT THE EASTERN SITES...AND BECOME
STRONGER LATER TONIGHT INTO SUNDAY AT ALL SITES. GUSTS TO 30
KNOTS ARE EXPECTED BY LATER TONIGHT...LASTING INTO SUNDAY. SOME
35 KNOT GUSTS ARE POSSIBLE. THERE IS SOME LOW LEVEL WIND SHEAR
POTENTIAL TONIGHT INTO EARLY SUNDAY MORNING...AS 1500 FOOT WINDS
MAY REACH 45 KNOTS. HOWEVER...SURFACE WINDS AND GUSTS SHOULD BE
STRONG ENOUGH TO NEGATE MENTION FOR NOW.
VFR CEILINGS TONIGHT INTO SUNDAY WILL GRADUALLY LOWER. RAIN
SHOWERS ARE POSSIBLE MAINLY LATER TONIGHT INTO SUNDAY. FOR
NOW...WILL CONTINUE MENTION IN TAFS FOR MADISON. THE EASTERN
SITES MAY NOT SEE THE SHOWERS UNTIL SUNDAY NIGHT. MVFR CEILINGS
AND VISIBILITIES ARE POSSIBLE...BUT WILL LEAVE OUT MENTION DUE TO
LOW CONFIDENCE.
&&
.MARINE...NORTHEAST WINDS OF 15 TO 20 KNOTS ARE EXPECTED THIS
AFTERNOON...WITH WAVES OF 2 TO 4 FEET. A FEW GUSTS MAY REACH 22
KNOTS...BUT NOT FREQUENT ENOUGH TO ISSUE A SMALL CRAFT ADVISORY.
A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR SUNDAY INTO AT
LEAST TUESDAY...WITH PERSISTENT AND GUSTY ONSHORE WINDS AS LOW
PRESSURE APPROACHES THE REGION. HIGH WAVES ARE LIKELY AS
WELL...BUILDING INTO THE 5 TO 10 FOOT RANGE BY SUNDAY NIGHT. DO
NOT THINK GALES WILL OCCUR SUNDAY...AS INVERSION ABOVE SURFACE
SHOULD LIMIT MIXING OF WINDS TO AROUND 30 KNOTS AT BEST.
&&
.PREV DISCUSSION... /ISSUED 347 AM CDT SAT APR 26 2014/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
SURFACE OBS AND LOCAL RADAR SHOW COLD FRONT HAD PUSHED THROUGH ALL
BUT THE FAR SW PORTION OF CWA BY 07Z. AS VORT MAX OVER THE SOO
MOVES OFF TO THE EAST OVER LAKE HURON...A COMBINATION OF 700 MB WARM
AIR ADVECTION AND CONVERGENCE ON PERIPHERY OF MID-LEVEL CYCLONIC
FLOW IS PRODUCING ACCAS SHOWERS OVER NRN IL...WELL DEPICTED ON 00Z
GFS AND HI-RES/RAPID UPDATE MODELS. STEEP LAPSE RATES ABOVE 850 MB
AND MEAGER ELEVATED CAPE...REFLECTED ON RAP SOUNDINGS...PRODUCING
LIGHT SHOWERS WITH REPORTS OF IN-CLOUD LIGHTNING OVER NRN IL. MODELS
ALL KEEP THIS BAND OUT OF THE CWA AS IT SHIFTS TO THE EAST-SOUTHEAST
OF IL BY 12Z.
SOUTHERN PORTION OF SURFACE HIGH SETTLING OVER STATE TODAY AND 500
MB RIDGING WILL KEEP THE DAYTIME HOURS DRY...WITH A COOL NORTHEAST
TO EAST WIND PREVENTING HIGHS IN THE LAKESHORE COUNTIES FROM GETTING
OUT OF THE 40S. LOW TO MID 50S EXPECTED WEST OF THE KETTLE
MORAINE...WITH MID-UPR 50S FROM MADISON WEST...WITH A 60 OR TWO IN
THE FAR SW.
MODELS DEPICTING NICE BAND OF MAINLY ISENTROPICALLY-DRIVEN 700 MB
OMEGA AND HIGHER RH CROSSING REGION AFTER 00Z SUNDAY...AND ARE
PRODUCING SOME LIGHT QPF. BUT SIMILAR TO EARLIER THIS WEEK...CROSS
SECTIONS AND FORECAST SOUNDINGS SHOWING RELATIVELY DRY EASTERLY FLOW
PREVENTING SATURATION BELOW 7K-8K FEET THROUGH MOST OF THE
NIGHT...WITH SOME SATURATION IN THE FAR WEST AFTER 06Z. WILL KEEP
POPS NO HIGHER THAN THE CHANCE CATEGORY PRIOR TO 12Z EXCEPT FOR LOW
LIKELY POPS IN THE EXTREME WEST AFTER 09Z.
SUNDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
THE OCCLUDED LOW PRESSURE SYSTEM WILL STALL OVER THE CENTRAL PLAINS
UNTIL EARLY NEXT WEEK. THE 925MB WARM FRONT WILL BE STATIONED ACROSS
NORTHERN IL ON SUNDAY...THEN CREEP NORTHWARD INTO FAR SOUTHERN WI
THROUGH MONDAY NIGHT. MEANWHILE...THE 850MB WARM FRONT WILL REMAIN
STATIONARY OVER CENTRAL WI.
THE INITIAL WARM AIR ADVECTION SHOWERS ON SUNDAY WILL STRUGGLE TO
OVERCOME THE LOW LEVEL DRY AIR IN PLACE. THE DEEP MOISTURE WILL
FINALLY ARRIVE SUNDAY EVENING AS WAVES OF VORTICITY AND WARM AIR
ADVECTION LEAD TO STRONG UPWARD MOTION OVER SOUTHERN WI. STEEP MID
LEVEL LAPSE RATES AND THE STRONG OMEGA WILL ALLOW FOR EMBEDDED
THUNDERSTORMS.
MODERATE RAIN SHOWERS WITH PERIODS OF HEAVY RAIN WILL BE POSSIBLE
SUNDAY NIGHT THROUGH MONDAY NIGHT. RAINFALL TOTALS DURING THIS TIME
ARE ESTIMATED TO BE IN THE 1.3 TO 1.8 INCH RANGE WITH THE HIGHER
TOTALS IN SW WI AND THE LOWER TOTALS OVER EAST CENTRAL WI. THIS RAIN
AND THE ADDITIONAL EXPECTED NEXT WEEK WILL CAUSE MANY RIVERS TO
REACH BANKFULL STAGE AND AT LEAST A FEW REACHING MINOR FLOOD STAGE.
PLAN ON BREEZY EAST WINDS SUNDAY AND MONDAY WITH THE SURFACE LOW
PARKED OVER NEBRASKA. THIS WILL KEEP TEMPERATURES VERY COOL IN THE
UPPER 40S AND LOWER 50S.
LONG TERM...
TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
THE OCCLUDED LOW WILL MEANDER NORTHEAST OVER THE UPPER GREAT LAKES
THROUGH THURSDAY. THE DRY SLOT IS EXPECTED TO ARRIVE INTO SOUTHERN
WI SOMETIME TUESDAY OR TUESDAY NIGHT WHICH WOULD CUT OFF THE DEEP
MOISTURE. CLOUDS AND SCATTERED SHOWERS WILL CONTINUE TO BE POSSIBLE
THROUGH FRIDAY DUE TO THE CYCLONIC FLOW AND LINGERING LOW LEVEL
MOISTURE. WINDS WILL GENERALLY BE OUT OF THE EAST FOR THE WEEK WHICH
MEANS COOLER NEAR THE LAKE WITH HIGHS IN THE UPPER 40S THERE AND
LOWER 50S INLAND.
MODELS ARE SHOWING ANOTHER UPPER TROUGH SWINGING DOWN THROUGH WI FOR
NEXT WEEKEND WHICH WOULD ALLOW FOR MORE CLOUDS AND SHOWERS. THERE IS
STILL UNCERTAINTY IN TIMING...SO THERE MAY BE A PERIOD OF DRY
WEATHER ON FRIDAY OR SATURDAY.
AVIATION/12Z TAFS/...
VFR CONDITIONS THROUGH THE PERIOD WITH RAIN EXPECTED TO HOLD OFF
UNTIL AROUND/SHORTLY AFTER 12Z SUNDAY...THOUGH A FEW SPRINKLES
POSSIBLER BEFORE...ESPECIALLY AT KMSN AND WEST.
NORTH WINDS THIS MORNING BEHIND COLD FRONT WILL TURN NORTHEAST AND
THEN EAST AS RIDGE OF SURFACE HIGH PRESSURE NOSES OVER STATE...THEN
INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS RIDGE SHIFTS OVER
LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES OUT INTO THE CENTRAL
PLAINS.
MARINE...
LOOKING AT NORTH WINDS THIS MORNING TURNING NORTHEAST AND EAST AS
RIDGE OF SURFACE HIGH PRESSURE NOSES DOWN OVER STATE AND LAKE
MICHIGAN...THEN INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS
RIDGE SHIFTS OVER LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES
OUT INTO THE CENTRAL PLAINS. THE SOMETIMES GUSTY ONSHORE WINDS ARE
EXPECTED TO PERSIST FROM SUNDAY INTO WEDNESDAY...AS THE LOW PRESSURE
SLOWLY APPROACHES THE AREA. THESE WIND GUSTS WILL LIKELY REACH SMALL
CRAFT CRITERIA AT TIMES....WITH WINDS JUST A FEW HUNDRED FEET OFF
THE SURFACE REACHING 40 KTS. DO NOT FEEL THESE STRONGER WINDS WILL
MIX DOWN THROUGH THE NEAR-WATER STABLE LAYER...BUT A FEW GALE GUSTS
ARE NOT OUT OF THE QUESTION...ESPECIALLY SUNDAY NIGHT INTO MONDAY
EVENING. THE ONSHORE WINDS SHOULD ALSO GENERATE WAVES IN THE 3 TO 6
FOOT RANGE. A SMALL CRAFT ADVISORY MAY BE NEEDED AT TIMES DURING
THIS PERIOD.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
347 AM CDT SAT APR 26 2014
.SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
SURFACE OBS AND LOCAL RADAR SHOW COLD FRONT HAD PUSHED THROUGH ALL
BUT THE FAR SW PORTION OF CWA BY 07Z. AS VORT MAX OVER THE SOO
MOVES OFF TO THE EAST OVER LAKE HURON...A COMBINATION OF 700 MB WARM
AIR ADVECTION AND CONVERGENCE ON PERIPHERY OF MID-LEVEL CYCLONIC
FLOW IS PRODUCING ACCAS SHOWERS OVER NRN IL...WELL DEPICTED ON 00Z
GFS AND HI-RES/RAPID UPDATE MODELS. STEEP LAPSE RATES ABOVE 850 MB
AND MEAGER ELEVATED CAPE...REFLECTED ON RAP SOUNDINGS...PRODUCING
LIGHT SHOWERS WITH REPORTS OF IN-CLOUD LIGHTNING OVER NRN IL. MODELS
ALL KEEP THIS BAND OUT OF THE CWA AS IT SHIFTS TO THE EAST-SOUTHEAST
OF IL BY 12Z.
SOUTHERN PORTION OF SURFACE HIGH SETTLING OVER STATE TODAY AND 500
MB RIDGING WILL KEEP THE DAYTIME HOURS DRY...WITH A COOL NORTHEAST
TO EAST WIND PREVENTING HIGHS IN THE LAKESHORE COUNTIES FROM GETTING
OUT OF THE 40S. LOW TO MID 50S EXPECTED WEST OF THE KETTLE
MORAINE...WITH MID-UPR 50S FROM MADISON WEST...WITH A 60 OR TWO IN
THE FAR SW.
MODELS DEPICTING NICE BAND OF MAINLY ISENTROPICALLY-DRIVEN 700 MB
OMEGA AND HIGHER RH CROSSING REGION AFTER 00Z SUNDAY...AND ARE
PRODUCING SOME LIGHT QPF. BUT SIMILAR TO EARLIER THIS WEEK...CROSS
SECTIONS AND FORECAST SOUNDINGS SHOWING RELATIVELY DRY EASTERLY FLOW
PREVENTING SATURATION BELOW 7K-8K FEET THROUGH MOST OF THE
NIGHT...WITH SOME SATURATION IN THE FAR WEST AFTER 06Z. WILL KEEP
POPS NO HIGHER THAN THE CHANCE CATEGORY PRIOR TO 12Z EXCEPT FOR LOW
LIKELY POPS IN THE EXTREME WEST AFTER 09Z.
SUNDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
THE OCCLUDED LOW PRESSURE SYSTEM WILL STALL OVER THE CENTRAL PLAINS
UNTIL EARLY NEXT WEEK. THE 925MB WARM FRONT WILL BE STATIONED ACROSS
NORTHERN IL ON SUNDAY...THEN CREEP NORTHWARD INTO FAR SOUTHERN WI
THROUGH MONDAY NIGHT. MEANWHILE...THE 850MB WARM FRONT WILL REMAIN
STATIONARY OVER CENTRAL WI.
THE INITIAL WARM AIR ADVECTION SHOWERS ON SUNDAY WILL STRUGGLE TO
OVERCOME THE LOW LEVEL DRY AIR IN PLACE. THE DEEP MOISTURE WILL
FINALLY ARRIVE SUNDAY EVENING AS WAVES OF VORTICITY AND WARM AIR
ADVECTION LEAD TO STRONG UPWARD MOTION OVER SOUTHERN WI. STEEP MID
LEVEL LAPSE RATES AND THE STRONG OMEGA WILL ALLOW FOR EMBEDDED
THUNDERSTORMS.
MODERATE RAIN SHOWERS WITH PERIODS OF HEAVY RAIN WILL BE POSSIBLE
SUNDAY NIGHT THROUGH MONDAY NIGHT. RAINFALL TOTALS DURING THIS TIME
ARE ESTIMATED TO BE IN THE 1.3 TO 1.8 INCH RANGE WITH THE HIGHER
TOTALS IN SW WI AND THE LOWER TOTALS OVER EAST CENTRAL WI. THIS RAIN
AND THE ADDITIONAL EXPECTED NEXT WEEK WILL CAUSE MANY RIVERS TO
REACH BANKFULL STAGE AND AT LEAST A FEW REACHING MINOR FLOOD STAGE.
PLAN ON BREEZY EAST WINDS SUNDAY AND MONDAY WITH THE SURFACE LOW
PARKED OVER NEBRASKA. THIS WILL KEEP TEMPERATURES VERY COOL IN THE
UPPER 40S AND LOWER 50S.
.LONG TERM...
TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
THE OCCLUDED LOW WILL MEANDER NORTHEAST OVER THE UPPER GREAT LAKES
THROUGH THURSDAY. THE DRY SLOT IS EXPECTED TO ARRIVE INTO SOUTHERN
WI SOMETIME TUESDAY OR TUESDAY NIGHT WHICH WOULD CUT OFF THE DEEP
MOISTURE. CLOUDS AND SCATTERED SHOWERS WILL CONTINUE TO BE POSSIBLE
THROUGH FRIDAY DUE TO THE CYCLONIC FLOW AND LINGERING LOW LEVEL
MOISTURE. WINDS WILL GENERALLY BE OUT OF THE EAST FOR THE WEEK WHICH
MEANS COOLER NEAR THE LAKE WITH HIGHS IN THE UPPER 40S THERE AND
LOWER 50S INLAND.
MODELS ARE SHOWING ANOTHER UPPER TROUGH SWINGING DOWN THROUGH WI FOR
NEXT WEEKEND WHICH WOULD ALLOW FOR MORE CLOUDS AND SHOWERS. THERE IS
STILL UNCERTAINTY IN TIMING...SO THERE MAY BE A PERIOD OF DRY
WEATHER ON FRIDAY OR SATURDAY.
&&
.AVIATION/12Z TAFS/...
VFR CONDITIONS THROUGH THE PERIOD WITH RAIN EXPECTED TO HOLD OFF
UNTIL AROUND/SHORTLY AFTER 12Z SUNDAY...THOUGH A FEW SPRINKLES
POSSIBLER BEFORE...ESPECIALLY AT KMSN AND WEST.
NORTH WINDS THIS MORNING BEHIND COLD FRONT WILL TURN NORTHEAST AND
THEN EAST AS RIDGE OF SURFACE HIGH PRESSURE NOSES OVER STATE...THEN
INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS RIDGE SHIFTS OVER
LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES OUT INTO THE CENTRAL
PLAINS.
&&
.MARINE...
LOOKING AT NORTH WINDS THIS MORNING TURNING NORTHEAST AND EAST AS
RIDGE OF SURFACE HIGH PRESSURE NOSES DOWN OVER STATE AND LAKE
MICHIGAN...THEN INCREASE LATER TONIGHT WITH TIGHTENING GRADIENT AS
RIDGE SHIFTS OVER LOWER MICHIGAN AND DEEPENING LOW PRESSURE MOVES
OUT INTO THE CENTRAL PLAINS. THE SOMETIMES GUSTY ONSHORE WINDS ARE
EXPECTED TO PERSIST FROM SUNDAY INTO WEDNESDAY...AS THE LOW PRESSURE
SLOWLY APPROACHES THE AREA. THESE WIND GUSTS WILL LIKELY REACH SMALL
CRAFT CRITERIA AT TIMES....WITH WINDS JUST A FEW HUNDRED FEET OFF
THE SURFACE REACHING 40 KTS. DO NOT FEEL THESE STRONGER WINDS WILL
MIX DOWN THROUGH THE NEAR-WATER STABLE LAYER...BUT A FEW GALE GUSTS
ARE NOT OUT OF THE QUESTION...ESPECIALLY SUNDAY NIGHT INTO MONDAY
EVENING. THE ONSHORE WINDS SHOULD ALSO GENERATE WAVES IN THE 3 TO 6
FOOT RANGE. A SMALL CRAFT ADVISORY MAY BE NEEDED AT TIMES DURING
THIS PERIOD.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1050 PM MDT SUN APR 27 2014
.UPDATE...
ISSUED AT 1050 PM MDT SUN APR 27 2014
UPDATED TO INCREASE POPS ACROSS THE CENTRAL MTS THROUGH THE
OVERNIGHT.
UPDATE ISSUED AT 856 PM MDT SUN APR 27 2014
UPDATED FOR LATEST OBS...SATELLITE AND RADAR TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 327 PM MDT SUN APR 27 2014
CURRENTLY...STRONG UPPER LEVEL AND SURFACE LOW PRESSURE STACKED OVER
NORTHWESTERN KS WITH SOUTHERN END OF WRAP AROUND DEFORMATION PRECIP
SLOWLY WEAKENING OVER SOUTHEAST CO. FARTHER WEST...LAPS SURFACE
PRESSURE DATA SHOWS WEAK SECONDARY LOW PRESSURE NEAR KPUB...WHICH
HAS CREATED LIGHTER WINDS OVER MUCH OF PUEBLO COUNTY THIS
AFTERNOON...AND HAS IN GENERAL WEAKENED THE PRESSURE GRADIENT ACROSS
SOUTHEAST COLORADO. WITH CONVECTION ENDING AND STRONG SURFACE
GRADIENT LACKING...WIND SPEEDS HAVE BEGUN TO VERY SLOWLY DECREASE
ACROSS THE PLAINS...AND STRONGEST GUSTS HAVE FALLEN BACK INTO THE 40-
45 KT RANGE. LATEST HRRR SUGGESTS WIND SPEEDS HAVE ALREADY
PEAKED...AND GIVEN LACK OF OBSERVED 50 KT GUSTS...WILL CANCEL THE
HIGH WIND WARNING FOR THE FAR SOUTHEAST. OVER THE MOUNTAINS...STILL
SOME -SHSN OVER THE CONTINENTAL DIVIDE...THOUGH WEB CAMS SUGGEST
LITTLE IN THE WAY OF ACCUMULATION OR LOW VISIBILITY...AT LEAST AT
PASS LEVEL.
TONIGHT...WILL KEEP SOME LOW POPS IN THE EVENING TO ACCOUNT FOR
LINGERING -SHRA OVER THE SOUTHEAST PLAINS...WITH SOME HIGHER POPS
FOR THE CENTRAL MOUNTAINS ALONG THE CONTINENTAL DIVIDE...WHERE
SECONDARY UPPER WAVE WILL LIKELY HELP INCREASE -SHSN COVERAGE LATER
TONIGHT. EXPECT WINDS TO GRADUALLY DIMINISH ALL AREAS THROUGH THE
NIGHT...THOUGH MANY LOCATIONS WILL STAY BREEZY AS STRONG WINDS JUST
OFF THE SURFACE PERSIST. EXPECTING ENOUGH IN THE WAY OF WINDS/CLOUDS
TO KEEP PLAINS FROM A HARD FREEZE...THOUGH MOST MOUNTAINS AND HIGH
VALLEYS WILL DROP INTO THE 20S OR COLDER.
MONDAY...UPPER LOW VERY SLOWLY DRIFTS INTO ERN NEBRASKA DURING THE
DAY...KEEPING STRONG NW FLOW AT THE SURFACE AND ALOFT ACROSS MOST OF
SOUTHERN COLORADO. EXPECT WINDS TO INCREASE ALL AREAS BY MID
MORNING...WITH GUSTS IN THE 30-40 KT RANGE MOST LOCATIONS BY
AFTERNOON. GIVEN RATHER COLD AIR ALOFT/STEEP LAPSE RATES IN PLACE
MON AFTERNOON...SUSPECT AT LEAST ISOLATED RAIN AND SNOW SHOWERS WILL
DEVELOP OVER THE MOUNTAINS...WITH PERHAPS A FEW SPRINKLES/LIGHT
SHOWERS OVER LOWER ELEVATIONS LATE IN THE DAY. LOW LEVELS WILL BE
FAIRLY DRY...WHICH WILL KEEP PRECIP AMOUNTS LIGHT. MAX TEMPS WILL
REMAIN COOL...WITH BLENDED NUMERICAL GUIDANCE LOOKING OK FOR HIGHS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 327 PM MDT SUN APR 27 2014
VERY UNSETTLED PATTERN QUEUED UP FOR THE FORECAST AREA THROUGH THE
EXTENDED FORECAST...BUT MODELS ARE LEANING TOWARDS TWO SEPARATE
PERIODS OF WEATHER TYPES.
MONDAY NIGHT THROUGH THURSDAY...LONG RANGE MODELS INDICATE THAT THE
UPPER LOW PRESSURE SYSTEM WILL PINWHEEL ABOUT THE US CENTRAL PLAINS
AND UPPER MISSISSIPPI RIVER VALLEY THROUGH THU...BEFORE FINALLY
EJECTING TO THE NE ACROSS THE GREAT LAKES. THIS SOLUTION WILL KEEP
VERY BRISK AND COOL NORTHERLY FLOW IN PLACE FOR THE STATE INTO
THU...AS WELL AS A DAILY SHOT OF SHOWER ACTIVITY FOR THE CWA. AS THE
LOW LINGERS...LOBES OF ENERGY WILL ROTATE AROUND THE SYSTEM AND
BRING PERIODICALLY BETTER CHANCES FOR SHOWERS...THOUGH THE EXACT
TIMING OF THESE WINDOWS IS NEAR IMPOSSIBLE TO PREDICT AT THIS TIME.
LOOK FOR MAX TEMPS EACH DAY IN THE 50S TO AROUND 60 F FOR THE LOWER
ELEVATIONS...AND 30S TO 40S FOR THE MTS. THE HIGHER TERRAIN IS
EXPECTED TO EXPERIENCE ISOLATED TO LOW END SCATTERED POPS THROUGH
THU...WITH THE BEST SHOT OF SOME ISOLATED CONVECTION FOR THE PLAINS
COMING TUE AFTN...AND AGAIN WED AFTN AND EVE.
FRIDAY THROUGH SUNDAY...THE GFS AND EC MODELS HINT THAT BY FRI THE
UPPER LOW WILL FINALLY BE PULLING AWAY FROM THE REGION...ALLOWING
THE UPPER FLOW TO SHIFT TO A MORE WESTERLY DIRECTION INTO THE
WEEKEND. BOTH MODELS DO CONTINUE TO SHOW MEAGER SHOWER ACTIVITY BOTH
FRI AND SAT...MAINLY TIED TO THE HIGHER TERRAIN...BUT FEEL THAT THIS
FAR OUT THIS MAY BE A BIT OVERDONE. BY SUNDAY PCPN SHOULD COME TO AN
END. LOOK FOR A WARMING TREND INTO THE WEEKEND AS THE UPPER FLOW
SHIFTS...WITH MAX TEMPS IN THE 60S FOR FRI...THEN 70S FOR BOTH SAT
AND SUN. MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1050 PM MDT SUN APR 27 2014
MODERATE TO STRONG NORTH TO NORTHWEST FLOW ALOFT WILL PERSIST
ACROSS THE STATE THROUGH THE MIDDLE OF THE WORK WEEK. THIS WILL
KEEP BREEZY TO WINDY CONDITIONS ACROSS THE AREA FROM THE LATE
MORNINGS THROUGH THE LATE EVENING HOURS. WITH THAT SAID...VFR
CONDITIONS EXPECTED AT ALS...COS AND PUB OVER THE NEXT 24 HOURS.
SHOULD SEE GUSTY NORTH TO NORTHWEST WIND OF 20-35KT DEVELOPING AT
TAF SITES AFT 16Z AND DIMINISH AFT 02Z. COULD SEE ISOLATED SHOWERS
ACROSS THE HIGHER TERRAIN AFT 18Z...THOUGH DOES NOT LOOK TO AFFECT
TAFS ATTM.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MW
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...MW
AREA FORECAST DISCUSSION
NWS ALBANY NY
444 AM EDT MON APR 28 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 445 AM EDT...PATCHY CLOUDS ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS...AND THE UPPER HUDSON VALLEY REGION ARE FINALLY
BEGINNING TO ERODE. WE EXPECT THESE CLOUDS TO CONTINUE TO DECREASE
IN AREAL COVERAGE THROUGH SUNRISE...ALLOWING TEMPS TO FALL SEVERAL
MORE DEGREES IN MOST AREAS.
AFTER DAYBREAK...WE EXPECT MOSTLY SUNNY SKIES TO START THE DAY.
HOWEVER...ADDITIONAL PATCHES OF CLOUDS ARE EXPECTED TO APPROACH FROM
THE NORTHEAST LATER TODAY...AFFECTING MAINLY SOUTHERN VT...NORTHERN
MA...AND POSSIBLY THE UPPER HUDSON RIVER VALLEY. IN
ADDITION...HIGHER CLOUDS WILL BEGIN TO APPROACH SOUTHERN AND WESTERN
AREAS LATE THIS AFTERNOON.
THE CLOUDS ACROSS NORTHEAST AREAS WILL BE THE RESULT OF SOME
RESIDUAL MOISTURE ROTATING AROUND THE WESTERN PERIPHERY OF THE STORM
SYSTEM WELL OFF THE NEW ENGLAND COAST. SOME OF THE HI-RES
MODELS...INCLUDING THE HRRR AND THE OPERATIONAL NAM WRF HINT AT SOME
LIGHT SHOWERS OR SPRINKLES POSSIBLY AFFECTING SOME HIGHER ELEVATIONS
OF SOUTHERN VT BY EVENING. WILL INDICATE SOME SLIGHT CHC POPS FOR
ISOLATED SHOWERS/SPRINKLES IN THIS REGION TO ACCOUNT FOR THIS REMOTE
POSSIBILITY.
DEEP MIXING TODAY TO AROUND 825 MB SHOULD ALLOW TEMPS TO REACH 60-65
IN MOST VALLEY AREAS...AND 55-60 ACROSS HIGHER ELEVATIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
TONIGHT...A DEVELOPING EASTERLY LOW LEVEL FLOW WILL INITIALLY ENHANCE
LOW LEVEL MOISTURE AND LOW CLOUD POTENTIAL ACROSS THE REGION
LATER TONIGHT. THIS IS PARTICULARLY SUGGESTED BY THE RUC-13 AND
NAM...AS WELL AS THE REGIONAL GEM. IN ADDITION...HIGH CLOUDS WILL
CONTINUE TO INCREASE FROM THE SOUTH AND WEST. SO...WILL INDICATE
PARTLY TO MOSTLY CLOUDY SKIES OVERNIGHT...WITH CLOUDS BECOMING
MOST WIDESPREAD AFTER MIDNIGHT. WILL ALSO KEEP SLIGHT CHC POPS
ACROSS PORTIONS OF SOUTHERN VT/NORTHWEST MA FOR SOME ISOLATED
SHOWERS OR SPRINKLES...ESP THIS EVENING. WILL ALSO SIDE ON THE
MILDER SIDE OF GUIDANCE...WITH GENERALLY 40-45 EXPECTED IN
VALLEYS...AND 35-40 ACROSS HIGHER TERRAIN.
TUESDAY...THE MID LEVEL RIDGE AXIS WILL SLOWLY MOVE EAST OF THE
REGION DURING THE DAY...ALLOWING DEEPER MOISTURE TO BEGIN TO
OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST. HOWEVER...IT
APPEARS THAT FOR AREAS NEAR AND E OF THE HUDSON RIVER VALLEY...MOST
OF THE MORNING HOURS SHOULD REMAIN DRY. WILL LIMIT POPS IN THESE
AREAS FOR THE AFTERNOON HOURS...MAINLY IN THE CHC RANGE. TO THE
W...WILL INDICATE MAINLY CHC POPS IN THE MORNING...AND BOOST TO
LIKELY IN THE AFTERNOON. MOST OF THE RAIN SHOULD BE LIGHT...AS IT
WILL ENCOUNTER INITIALLY DRY LOW/MID LEVEL AIR AND MID LEVEL
SUBSIDENCE. TEMPS WILL BE SOMEWHAT TRICKY...AS ANY DELAY IN RAINFALL
WILL ALLOW FOR WARMER MAX TEMPS. WILL SIDE ON THE WARMER SIDE OF
GUIDANCE ACROSS THE UPPER HUDSON RIVER VALLEY AND SOUTHERN
VT...WHERE THE RAIN SHOULD DEVELOP LATEST...AND THE POSSIBILITY FOR
SOME THIN SPOTS ON THE OVERCAST WILL BE GREATEST. IN ADDITION...SOME
ENHANCED DOWNSLOPING WITH THE INCREASING E/SE LOW LEVEL FLOW MAY
HELP BOOST TEMPS FURTHER IN THESE AREAS...WHICH COULD REACH AROUND
60. ELSEWHERE...EXPECT MAX TEMPS TO REACH THE MID/UPPER 50S IN
VALLEYS FROM ALBANY N...W AND NORTHEAST...AND 50-55 TO THE SOUTH AND
WEST WHERE CLOUDS...RAIN...AND A COOLER MARINE MODIFIED AIR MASS
SHOULD KEEP TEMPS COOLER.
TUE NT-WED...ALTHOUGH IT APPEARS UNSETTLED DURING THIS PERIOD...IT
LOOKS LIKE IT WON/T BE A COMPLETE WASHOUT...AS POCKETS OF SYNOPTIC
LIFT MOVE ACROSS THE REGION. HOWEVER...THE GREATEST FORCING AND LOW
LEVEL MOISTURE CONVERGENCE WILL REMAIN MAINLY SOUTH AND WEST OF THE
REGION. SO...EXPECT SEVERAL ROUNDS OF SHOWERS AND/OR PERIODS OF
RAINFALL...BUT THERE COULD EASILY BE SOME PERIODS WHERE ONLY SOME
SPRINKLES OR PATCHY DRIZZLE OCCUR. AS A WEDGE OF DRIER AIR
ADVECTS WESTWARD AROUND THE SOUTHERN PERIPHERY OF THE VERY STRONG
HIGH TO OUR N...THERE IS ACTUALLY SOME POTENTIAL FOR SLEET TO MIX
IN WITH ANY SHOWERS ACROSS HIGHER ELEVATIONS OF THE SOUTHERN
ADIRONDACKS AND WESTERN NEW ENGLAND LATE TUE NT/EARLY WED AM.
TEMPS WILL COOL INTO THE MID 30S TO LOWER 40S TUE NT...AND SHOULD
ONLY REACH THE MID 40S TO LOWER 50S ON WED. IN FACT...SHOULD
RAINFALL BE MORE PERSISTENT/STEADIER ON WED...EVEN COOLER MAX
TEMPS COULD OCCUR...WITH MOST AREAS REMAINING BELOW 50. WINDS WILL
ALSO INCREASE DURING THIS PERIOD AS THE LOW LEVEL PRESSURE
GRADIENT TIGHTENS BETWEEN THE AFOREMENTIONED STRONG EASTERN
CANADIAN HIGH...AND LOW PRESSURE APPROACHING FROM THE SOUTH AND
WEST. EAST/SOUTHEAST WINDS WILL BECOME QUITE GUSTY AT TIMES...WITH
SOME GUSTS OF 30-40 MPH POSSIBLE AT TIMES BY WED
AFTN...PARTICULARLY ACROSS HIGHER ELEVATIONS OF THE
TACONICS...SOUTHERN GREEN MTNS...AND NORTHERN BERKSHIRES...AS WELL
AS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...MOHAWK VALLEY AND
CATSKILLS.
WED NT...THE BEST FORCING FROM THE COMBINATION OF ISENTROPIC
LIFT...MOISTURE TRANSPORT AND LOW LEVEL JET DYNAMICS APPEARS TO BE
DURING THIS PERIOD...LEADING TO WIDESPREAD SHOWERS OR A STEADY RAIN.
SOME OF THE RAIN COULD BE HEAVY AT TIMES. IT WILL ALSO INITIALLY
REMAIN WINDY...ESP THROUGH MIDNIGHT...WHERE SOME GUSTS INTO THE
35-45 MPH RANGE COULD OCCUR IN PORTIONS OF THE SOUTHERN GREENS AND
NORTHERN BERKSHIRES. IT APPEARS THAT A WIDESPREAD 1-2 INCHES OF
RAINFALL SHOULD OCCUR THROUGH DAYBREAK THU...WITH GREATER AMTS
POSSIBLE ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON
VALLEY...AND NW CT. OVERNIGHT MINS SHOULD MAINLY BE IN THE UPPER 30S
TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MORE UNSETTLED WEATHER IS EXPECTED TO LAST THROUGH THE UPCOMING
WEEKEND.
A VERTICALLY STACKED CUTOFF LOW WILL SIT AND SPIN OVER THE GREAT
LAKES REGION AS PIECES OF ENERGY ROTATE AROUND IT ACROSS THE
NORTHEAST. THIS WILL KEEP AT LEAST SCATTERED SHOWERS ACROSS OUR
REGION THURSDAY THROUGH SUNDAY. WHILE IT WILL NOT BE RAINING ALL OF
THE TIME THERE WILL BE PERIODS WHERE THE SHOWERS WILL BE MORE
NUMEROUS WHICH WILL BE ON THURSDAY INTO FRIDAY. RAINFALL AMOUNTS ON
THURSDAY THROUGH THURSDAY NIGHT WILL GENERALLY BE A THIRD OF AN INCH
TO THREE QUARTERS OF AN INCH. EXPECT HIGHS ON THURSDAY TO RANGE FROM
THE UPPER 50S AND LOWER 60S NORTHWEST TO LOWER 70S SOUTHEAST. LOWS
THURSDAY NIGHT WILL BE IN THE UPPER 30S TO UPPER 40S AND HIGHS ON
FRIDAY WILL BE IN THE MID 50S TO MID 60S.
THE UPPER LEVEL TROUGH WILL EXPAND EASTWARD TOWARDS THE NORTHEAST
FOR FRIDAY NIGHT INTO THE WEEKEND...AND START TO WEAKEN SOMEWHAT. AS A
RESULT...WE WILL STILL SEE THE OPPORTUNITY FOR SHOWERS EACH
DAY...MAINLY TIED TO DIURNAL HEATING AND TIMING OF WEAK VORTICITY
MAXES ROTATING AROUND THE UPPER LEVEL LOW. EXPECT LOWS FRIDAY NIGHT
TO RANGE FROM THE UPPER 30S NORTHWEST TO THE MID 40S SOUTHEAST WITH
HIGHS ON SATURDAY IN THE MID 50S TO MID 60S. LOWS ON SATURDAY NIGHT
ARE EXPECTED TO RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S
SOUTHEAST. THERE IS THE POSSIBILITY OF A LITTLE SNOW ACROSS THE
SOUTHERN ADIRONDACKS LATE SATURDAY NIGHT. HIGHS ON SUNDAY WILL BE IN
THE MID 50S TO LOWER 60S.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED AT ALL THE TAF SITES THROUGH THE END
OF THE TAF PERIOD ENDING AT 06Z TUESDAY. DURING THE OVERNIGHT
HOURS EXPECT SCT-BKN STRATOCU CLOUDS OVER THE AREA. THESE CLOUDS
WILL DISSIPATE BY DAYBREAK AT MOST SITES ALTHOUGH IT MAY TAKE A
LITTLE LONGER AT KALB AS THE CLOUD AREAS IS SHRINKING FROM THE
EAST AND WEST...SO KALB WILL LIKELY BE THE LAST TO LOSE THE CLOUD
DECK WHICH WILL BE AT 4-6 KFT OVERNIGHT. N-NE WINDS WL AVG 4-6 KTS
OVERNIGHT.
DURING THE DAY ON MONDAY...N-NW WINDS WILL BE ABOUT 5-10 KTS WITH
SCT DIURNAL CU AT 4-6 KFT DEVELOPING DURING THE DAY. THERE WILL BE
SOME PASSING CIRRUS CLOUDS AS WELL...BUT NO PRECIPITATION IS
EXPECTED DUE TO HIGH PRESSURE NEARBY...AND VFR CONDITIONS WILL
CONTINUE. THE CIRRUS CLOUDS WILL BECOME THICKER BY EVENING.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA.
WEDNESDAY: HIGH OPERATIONAL IMPACT.WINDY WITH GUSTS TO 31.0 LIKELY SHRA.
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. OCNL SHRA.
THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
...RH VALUES WILL FALL INTO THE 25-30 PERCENT RANGE THIS AFTERNOON...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY...ALONG WITH A
WETTING RAINFALL.
THE RH WILL FALL INTO THE 25-35 PERCENT RANGE FOR MOST AREAS THIS
AFTERNOON...LOWEST IN VALLEY AREAS. THE RH WILL THEN RECOVER TO
80-95 PERCENT TONIGHT...THEN FALL INTO THE 30-40 PERCENT RANGE FOR
NORTHERN AREAS...AND 40-60 PERCENT RANGE FOR SOUTHERN AND WESTERN
AREAS TUESDAY AFTERNOON.
NORTHWEST WINDS AT 5-10 MPH THIS MORNING WILL BECOME NORTH TO
NORTHEAST AND INCREASE TO 5-15 MPH THIS AFTERNOON...WITH SOME GUSTS
POSSIBLY REACHING UP TO 20 MPH AT TIMES ACROSS PORTIONS OF THE UPPER
HUDSON RIVER VALLEY. WINDS WILL VEER INTO THE EAST TONIGHT AT 5-15
MPH...THEN BECOME E TO SE ON TUESDAY AND INCREASE TO 10-20
MPH...WITH SOME GUSTS OF 20-30 MPH POSSIBLE IN THE AFTERNOON...ESP
ACROSS PORTIONS OF SOUTHERN VT.
A WETTING RAINFALL IS EXPECTED FOR LATE TUESDAY THROUGH THURSDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED THROUGH EARLY IN THE
WEEK.
EXPECTING DRY WEATHER THROUGH TONIGHT AS HIGH PRESSURE DOMINATES.
WET WEATHER WILL RETURN FOR MID WEEK AS A LARGE SLOW MOVING LOW
PRESSURE SYSTEM TO OUR WEST IMPACTS THE REGION. THIS SYSTEM HAS
THE POTENTIAL TO PRODUCE SOME HEAVY RAIN. HOWEVER THERE IS
UNCERTAINTY IN THE POTENTIAL QPF AMOUNTS. AT THIS TIME...IT
APPEARS THAT THE POTENTIAL FOR A WIDESPREAD 1-2 INCHES OF RAINFALL
IS INCREASING...WITH SOME LOCALLY HIGHER AMTS
POSSIBLE...PARTICULARLY ACROSS PORTIONS OF THE SE CATSKILLS...MID
HUDSON VALLEY...AND NW CT. THIS SHOULD CAUSE SIGNIFICANT WITHIN
BANK RISES ON MOST RIVERS...WITH THE POSSIBILITY OF SOME REACHING
ACTION STAGE...ESPECIALLY IN THE HOUSATONIC BASIN...AND POSSIBLY
ACROSS PORTIONS OF THE CATSKILLS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL/IAA/FRUGIS
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...FRUGIS/11
AVIATION...FRUGIS/11
FIRE WEATHER...KL/IAA
HYDROLOGY...KL/IAA
AREA FORECAST DISCUSSION
NWS JACKSON KY
152 AM EDT MON APR 28 2014
.UPDATE...
ISSUED AT 151 AM EDT MON APR 28 2014
CURRENTLY ACROSS EASTERN KENTUCKY...A LINE OF SHOWERS HAS MOVED
NORTHEAST THROUGH THE AREA ALONG THE WARM FRONT. BEHIND
THIS...ANOTHER LINE OF SHOWERS IS STARTING TO DEVELOP AS IT SLIDES
EAST AND EAST NORTHEAST THROUGH THE AREA. IT SEEMS A BIT MORE
INSTABILITY IS PRESENT WITH THIS AND UPSTREAM IN TN...SOME INDICATION
OF MORE MOIST AND UNSTABLE AIR IS STARTING TO STREAM NORTH. WITH ALL
THIS IN MIND...HAVE UPDATED THE FORECAST AND SENT OUT A ZFP TO BRING
IN POPS A BIT EARLIER AND BRING LIKELY POPS IN BY THE MORNING AS THE
ANTICIPATED FIRST WAVE BEHINDS TO PUSH NORTHEAST.
UPDATE ISSUED AT 1030 PM EDT SUN APR 27 2014
AS EXPECTED...EARLIER THUNDERSTORMS HAVE WEAKENED WITH JUST SOME
WIDELY ISOLATED SHOWERS PUSHING ACROSS THE AREA WITH THE WARM FRONT.
THIS ACTIVITY WILL CONTINUE TO PUSH NORTHWARD OVER THE NEXT 3 TO 5
HOURS...WITH DRIER WEATHER RETURNING THROUGH THE LATTER HALF OF THE
NIGHT. HOWEVER...PLENTY OF SHOWERS AND THUNDERSTORMS UPSTREAM ACROSS
ARKANSAS AND FAR WESTERN KENTUCKY. SOME OF THIS MAY CONGEAL INTO AN
MCS AND TRACK TOWARDS THE AREA TOMORROW MORNING. THIS COULD BRING THE
THREAT OF DAMP WEATHER BACK TO THE AREA AROUND OR SHORTLY AFTER
DAYBREAK. AT THIS TIME...IT DOES NOT APPEAR THIS ACTIVITY WILL POSE A
SEVERE RISK AS SURFACE INSTABILITY WILL BE AT A MINIMUM EARLY IN THE
MORNING. IT LOOKING MORE LIKE WE MAY HAVE MORE OF A SEVERE THREAT
ARRIVING MONDAY EVENING OR MONDAY NIGHT AS WE MAY SEE AN MCS MOVE
INTO THE AREA INTO THE OVERNIGHT TIME PERIOD. THUS...SEVERE THREAT
APPEARS TO BE PUSHED BACK INTO MONDAY EVENING OR MONDAY NIGHT.
UPDATE ISSUED AT 745 PM EDT SUN APR 27 2014
A FEW SHOWERS AND STORMS BEGINNING TO ENCROACH UPON EASTERN KENTUCKY.
THE FIRST ONE IS JUST GRAZING THE WESTERN EDGE OF WAYNE COUNTY AS IT
MOVES NORTHWARD...WITH A SECONDARY AREA MOVING INTO SOUTHERN
BELL/WHITLEY COUNTIES. NOT MUCH OTHER ACTIVITY ON RADAR AT PRESENT
TIME. WITH MORE OF A STRATIFORM LIGHT RAIN DEVELOPING FARTHER TO THE
SOUTHWEST ACROSS NORTH CENTRAL TENNESSEE. STILL PLENTY OF DRY AIR IN
PLACE ACROSS EASTERN KENTUCKY WHICH WILL LIKELY PUT THE END TO ANY
STORM CHANCES AS STUFF TRIES TO PUSH INTO THE AREA. THUS...WITH SUN
SETTING...WE WILL BE LOSING ANY INSTABILITY WE HAVE OUT THERE WITH
THUNDERSTORMS DIMINISHING TOWARDS SHOWERS. EVEN THE SHOWERS WILL HAVE
A TOUGH TIME SURVIVING AS THEY MOVE INTO THE DRIER AIR IN THE EAST.
THUS...HAVE BACKED OFF POPS THIS EVENING INTO THE OVERNIGHT HOURS.
ALSO BACKED OFF THUNDER CHANCES AFTER THE NEXT HOUR OR SO. NEXT ROUND
OF SHOWERS AND THUNDERSTORMS REMAIN OUT ACROSS WESTERN TENNESSEE AND
WESTERN KENTUCKY AND IF IT HOLDS TOGETHER...WOULD NOT BE INTO THE
AREA UNTIL AFTER MIDNIGHT. UPDATED FORECAST IS ALREADY OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 355 PM EDT SUN APR 27 2014
STARTING INTO AN ACTIVE PERIOD DURING THE SHORT TERM. A SURFACE LOW
PRESSURE SYSTEM WILL REMAIN OVER THE CENTRAL PLAINS THIS
EVENING...WHILE SEVERAL WAVES OF ENERGY WILL CONTINUE TO ROTATE
AROUND THIS SYSTEM. EASTERN KY WILL REMAIN IN THE WARM SECTOR...WITH
A WARM FRONT POSITIONED ACROSS MUCH OF THE STATE.
MEANWHILE...WESTERN AND CENTRAL KY WILL FIND THEMSELVES POSITIONED
BETWEEN THE WARM FRONT AND COLD FRONT...WITH WARM UNSTABLE AIR
CONTINUING TO FILTER IN AND ABUNDANT MOISTURE TO ACCOMPANY.
WHILE NOT MUCH PROGRESSION IS EXPECTED THIS AFTERNOON OR TONIGHT IN
TERMS OF THE SURFACE LOW AND THE ASSOCIATED FRONTS...THE INCREASED
INSTABILITY DURING THE AFTERNOON WILL WORK TO HELP ANY CONVECTIVE
DEVELOPMENT TO SPREAD EASTWARD SLOWLY. LATEST HIRES
MODELS...INCLUDING THE NAM12/HRRR/AND ECMWF ALL POINT AT PRECIP
ENTERING INTO EASTERN KY BETWEEN 0 AND 6Z AND THEN CONTINUING
EASTWARD THROUGHOUT THE NIGHT. IT IS ALSO AROUND THIS POINT THAT
GFS40 AND NAM12 FORECAST SOUNDINGS SHOW SOME IMPRESSIVE LOW LEVEL
SHEER IN PORTIONS OF EASTERN KY. WHILE LINGERING DRY LOW LEVEL AIR
AND SE DOWNSLOPE WINDS COULD WORK TO HOLD OFF SOME PRECIP IN THE
EVENING...EXPECT THAT ISOLATED TO SCATTERED SHOWERS WILL DEVELOP. IN
DOING SO...MOISTENING OF THE LOW LEVELS WILL BE ENOUGH TO ALLOW
UNSTABLE AIR TO RISE AND THUNDERSTORMS TO DEVELOP. IN
ADDITION...BASED ON STRONG STORMS THAT HAVE DEVELOPED
UPSTREAM...HAVE KEPT THUNDER AS THE PREDOMINATE WX TYPE THIS EVENING
AND THROUGH THE NIGHT.
BETWEEN 3Z AND 12Z MONDAY...CHANCE POPS WILL OVERSPREAD THE AREA.
HOWEVER...LATEST HI-RES GUIDANCE IS POINTING AT A DRY POCKET
DEVELOPING AS DOWNSLOPE FLOW INCREASES SLIGHTLY ACROSS THE SOUTHEAST
PORTION OF THE STATE. LATEST RUC13 OMEGA IS ALSO SUPPORTIVE OF THIS
IDEA...SHOWING DOWNWARD MOTION ACROSS THE SE PORTION OF THE STATE BY
9Z. THE QUESTION THEN WILL BE...HOW MUCH WILL THIS DOWNSLOPING
INHIBIT ANY STORM DEVELOPMENT? HOW FAR INTO EASTERN KY COULD IT
POTENTIALLY INHIBIT STORM GROWTH AND RAIN...AND WILL WE STILL EXPECT
SOME ISOLATED TO SCATTERED CHANCES...OR WILL DOWNSLOPE CUT OFF
POTENTIAL ALL TOGETHER? UNFORTUNATELY...THESE ARE ALL QUESTIONS
WHICH CAN/T REALLY BE ANSWERED UNTIL THE MAIN CONVECTION REACHES OUR
AREA. UNTIL THEN...WILL TRY TO PLAY ON THIS THINKING...AND TREND
DOWN POPS SLIGHTLY FOR THE SE PORTION OF THE CWA.
DURING THE DAY TOMORROW...SURFACE LOW WILL HAVE PROGRESSED ONLY
SLIGHTLY EASTWARD...THOUGH THE SURFACE COLD FRONT WILL HAVE ENTERED
INTO THE MISSISSIPPI VALLEY REGION. WITH THE FORCING SO GREAT IN
PROXIMITY TO THIS FRONT...AND A STRONG PULL OF GULF
MOISTURE...EXPECT SHOWERS/TSRA TO OVERCOME THE DOWNSLOPING PULL.
ESPECIALLY IF WINDS SHIFT MORE SOUTHERLY FOR A PERIOD OF
TIME...COULD SEE MORE WIDESPREAD DEVELOPMENT ACROSS THIS AREA.
UNFORTUNATELY...EVEN THE HI-RES MODELS ARE SHOWING SOME DISAGREEMENT
ON THE EXTENT AND MAGNITUDE OF PRECIP FOR TOMORROW...SO HAVE TRIED
TO STICK TO A BLEND. Q VECTORS ARE SHOWING THE BEST AREAS FOR UPWARD
MOTION AND STORM DEVELOPMENT REMAINING JUST TO OUR NORTH
TOMORROW...MAINLY OVER THE UPPER GREAT LAKES REGION. SOME DECENT
CONVERGENCE DOES MAKE IT INTO KY AS WELL...MOVING FROM WEST TO EAST
ACROSS THE STATE. AS IT HEADS INTO EASTERN KY...EVEN THE QVECTOR
CONVERGENCE PICKS UP ON A BRIEF LULL IN ACTIVITY ACROSS THE SE
PORTION OF THE STATE WITH DOWNSLOPE WINDS IN PLACE. THIS QUICKLY
DISAPPEARS AS THE BEST CONVERGENCE MOVES OVER THE REGION...SO
FURTHER SUPPORT THAT AT SOME POINT THE MOISTURE WILL BE ENOUGH TO
OVERCOME ANY EFFECTS FROM THE WIND DIRECTION. LOW LEVEL WIND SHEAR
DURING THE DAY TOMORROW ISN/T QUITE AS IMPRESSIVE AS THAT EXPECTED
THIS EVENING...BUT IT SEEMS TO BE A BIT DEEPER. WINDS IN THE UPPER
LEVELS ARE QUITE STRONG...SO EXPECT A GOOD DRIVING FORCE AND THE
POTENTIAL FOR A LINE OF SHOWERS/STORMS TO TRAVERSE KY /AS WAS
REFLECTED IN THE MONDAY EVENING/MONDAY NIGHT POPS AND WEATHER/.
MONDAY NIGHT/S LINE OF STORMS IS ALSO EXPECTED TO BRING THE BEST
THREAT FOR HEAVY PRECIP DURING THE SHORT TERM ACCORDING TO THE LAST
FEW MODEL RUNS. AFTER ROUND ONE OF PRECIP MOVES IN TONIGHT AND
TOMORROW...A STRONGER SECOND LINE WILL DEVELOP CLOSER TO THE FRONT.
MOISTURE GETTING PULLED IN WILL ALLOW FOR 6 HOUR QPF AMOUNTS WELL IN
THE 1 TO 3 INCH RANGE BY 6Z TUESDAY...TRAVERSING EASTERN KY DURING
THIS TIME. WITH THIS AMOUNT OF EXPECTED CONVECTIVE RAIN...AND THE
CONTINUED POTENTIAL FOR SOME THUNDERSTORMS PRODUCING HEAVY SHOWERS
OVER SMALL AREAS...THERE DOES LIE THE THREAT OF FLOODING ACROSS
PORTIONS OF THE STATE...INCLUDING EASTERN KY. WINDS ALOFT ARE QUITE
IMPRESSIVE AS THIS LINE MOVES OVER...SO ANY STORMS OR HEAVY RAIN
SHOWERS BRING THE THREAT OF TRANSFERRING SOME OF THESE POTENTIALLY
DAMAGING WINDS TO THE GROUND. AS FAR AS THE FLOODING...WILL
PROBABLY NEED TO ISSUE A WATCH AT SOME POINT IN THE NEAR FUTURE.
ELECTED NOT TO DURING THE DAY SHIFT JUST FOR THE SHEER FACT THAT THE
MODELS ARE STILL HAVING A HARD TIME AGREEING...AND REALLY ITS GOING
TO BE A MATTER OF HOW MUCH PRECIP WE END UP RECEIVING OVERNIGHT
TONIGHT AND TOMORROW MORNING TO KNOW HOW SATURATED THE SOIL WILL BE
LEADING INTO THE EVENING. WILL MENTION CONCERNS TO INCOMING SHIFT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 425 PM EDT SUN APR 27 2014
THE MODELS CONTINUE TO BE IN GOOD AGREEMENT ALOFT WITH THE LARGE AND
LUMBERING CLOSED LOW OVER THE MID SECTION OF THE NATION AT THE START
OF THE EXTENDED. THIS DOMINANT FEATURE ROLLS OVER ON ITSELF AS IT
SLOWLY FILLS AND LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN
GREAT LAKES BY 00Z THURSDAY. THE SYSTEM BECOMES MORE PROGRESSIVE
TOWARD THE END OF THE WEEK...EVENTUALLY EXITING INTO EASTERN CANADA.
BEFORE IT DOES SO...A CONTINUATION OF A SERIES OF MID LEVEL ENERGY
PACKETS WILL PLOW THROUGH KENTUCKY BRINGING PERIODIC SUPPORT TO
CONVECTION THROUGHOUT THE REGION. FOR TUESDAY...A KEY ONE OF THESE
PACKETS MOVES OVER EAST KENTUCKY EARLY FOLLOWED BY ANOTHER LATE IN
THE DAY AND INTO EARLY WEDNESDAY. THESE PACKETS DO WEAKEN WITH TIME
SO THAT THE VERSION THAT GOES THROUGH ON MIDDAY WEDNESDAY WILL
LIKELY NOT PACK THE PUNCH OF THE EARLIER ONES. FALLING HEIGHTS
LOCALLY WILL BE NOTED INTO THURSDAY MORNING EVEN AS THE MAIN LOW TO
THE NORTH WEAKENS BUT BY THIS TIME THE ENERGY SWIRLING PAST WILL BE
SIMILARLY WEAKER. IT IS ALSO ABOUT THIS TIME THAT THE AGREEMENT OF
THE GEM WITH THE NEARLY LOCKSTEP ECMWF AND GFS AT MID LEVELS FADES
AND ITS SOLUTION IS SUBSEQUENTLY DISCOUNTED. THE OTHER MODELS
CONTINUE TO MAINTAIN LOWER THAN NORMAL 500MB HEIGHTS OVER EAST
KENTUCKY INTO THE WEEKEND DUE TO THE ARRIVAL OF ANOTHER...MORE
PROGRESSIVE AND OPEN...TROUGH FROM THE PLAINS. THE GFS IS A BIT
BETTER CONSOLIDATED WITH THIS THAN THE ECMWF AS IT TAKES ITS AXIS
THROUGH EAST KENTUCKY EARLY SATURDAY WHILE THE ECMWF SNEAKS A LEAD
WAVE THROUGH ON FRIDAY WITH THE REST OF THE SYSTEM PASSING THROUGH
LATER SATURDAY. HEIGHTS WILL THEN TICK UP IN THE WAKE OF THIS ACTION
TO CLOSE OUT THE WEEKEND ON A WELCOMED QUIETER NOTE. FOR THE
FORECAST HAVE FOLLOWED A GENERAL MODEL BLEND THROUGH THE REST OF THE
WORK WEEK WITH A SLIGHT PREFERENCE FOR THE LATEST ECMWF THEREAFTER.
SENSIBLE WEATHER WILL FEATURE AT LEAST ONE LAST STORMY DAY AND NIGHT
TO START THE EXTENDED. THE EXPECTATION IS THAT AN ONGOING CLUSTER OF
STORMS WILL BE MOVING OUT OF EASTERN KENTUCKY AT 12Z TUESDAY.
HOWEVER...THE NEXT SURGE OF LIFT ASSOCIATED WITH THE MID LEVEL WAVE
ROLLING INTO THE AREA LATER THAT DAY WILL START TO ACT ON THE
ENVIRONMENT OF EAST KENTUCKY DURING THE AFTERNOON. THIS WILL COMBINE
WITH THE MOIST BOUNDARY LAYER...HEATING THROUGH THE DAY...TO
GENERATE DECENT INSTABILITY LIKELY KICKING OFF ANOTHER CONVECTIVE
CLUSTER. WITH THE VEERING SHEAR PROFILE AND POTENTIAL FOR HIGHER
INSTABILITY BY EVENING TUESDAY...WILL CONTINUE THE THREAT OF STRONG
TO SEVERE STORMS. THESE STORMS MAY LINGER INTO THE NIGHT BEFORE
CLEARING OUT TO THE EAST ALONG WITH THE SYSTEM/S SLOW MOVING COLD
FRONT FINALLY PUSHING OUT OF THE AREA. THE NEARBY FRONT AND LOW MID
LEVEL HEIGHTS SHOULD LEAVE WEDNESDAY WITH A POTENTIAL FOR RENEWED
CONVECTION...THOUGH THE THUNDER THREAT WILL PROBABLY BE LIMITED TO
THE FAR EAST AND MAINLY EARLIER IN THE DAY. THE THREAT OF SHOWERS
WILL THEN CONTINUE THROUGH THE REST OF THE WORK WEEK AND INTO THE
FIRST PART OF THE WEEKEND WHILE LIMITED INSTABILITY AND COOLER
TEMPERATURES KEEP THE THREAT OF THUNDER TO A MINIMUM. HAVE GONE WITH
DRY WEATHER FOR SUNDAY AS HIGH PRESSURE SHOULD BE MOVING OVERHEAD.
TEMPERATURES WILL BE DEFINITELY ON THE COOL SIDE OF NORMAL FOR THE
BULK OF THE EXTENDED IN THE WAKE OF THE SYSTEM/S SLOW MOVING COLD
FRONT PASSING THROUGH ON WEDNESDAY. TUESDAY REMAINS THE MOST
CHALLENGING DAY FOR MAX TEMPERATURES DUE TO QUESTIONS OF CLEARING
BEHIND THE DEPARTING EARLY MORNING BATCH OF CONVECTION. MORE...AND
QUICKER...CLEARING WILL ALLOW TEMPERATURES TO SOAR INTO THE UPPER
70S AND ALSO SPIKE THE INSTABILITY MAKING FOR A BETTER POTENTIAL FOR
SEVERE WEATHER. HOWEVER...THERE IS A POTENTIAL FOR CONVECTIVE DEBRIS
AND LINGERING LOW CLOUDS/SHOWERS TO KEEP TEMPERATURES CAPPED AND
INSTABILITY/SVR POTENTIAL MORE LIMITED.
THE CR GRID LOAD CAME IN PRETTY GOOD FOR THE BULK OF THE EXTENDED...
THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND...PARTICULARLY FOR
A DRY SUNDAY. DID ALSO FINE TUNE SOME LOW TEMP GRIDS LATER IN THE
FORECAST TO ALLOW FOR SOME ENHANCED RIDGE AND VALLEY DETAIL OVER THE
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 151 AM EDT MON APR 28 2014
VFR CONDITIONS WILL BEGIN THE TAF PERIOD THROUGH THE LATE TONIGHT
HOURS. BY THE MORNING...SHOWERS AND THUNDERSTORMS WILL BEGIN TO MOVE
INTO THE WESTERN CWA WITH A LINE PUSHING THROUGH THE TAF SITES AND
HAVE PUT IN SOME MVFR CONDITIONS THROUGH THE 12Z TO 16Z RANGE MAINLY
DUE TO VISIBILITY IN THE SLIGHTLY HEAVIER SHOWERS. WILL THEN SHOW
SOME VFR TOMORROW AFTERNOON BEFORE THE NEXT STRONG TO SEVERE LINE OF
SHOWERS AND STORMS MOVE IN BY THE LAST 6 HOURS OF THE TAF PERIOD AND
HAVE GONE IFR DURING THIS PERIOD. WINDS WILL BE OUT OF THE SOUTH FOR
MUCH OF THE PERIOD WITH GUSTS UP TO 20 KNOT OUTSIDE OF THUNDERSTORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...JMW
LONG TERM...GREIF
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1155 PM CDT SUN APR 27 2014
.DISCUSSION...
FOR 06Z TAFS...IFR CONDITIONS STARTING TO MOVE INTO WESTERN
AREA...WILL STAY THAT WAY THROUGH THE OVERNIGHT HOURS. MVFR
ELSEWHERE IS EXPECTED THROUGH THE MORNING. STILL NOT CERTAIN ON
HOW MUCH...IF ANY PRECIP WILL OCCUR AT SOUTHERN TAF SITES SO STILL
HOLDING OFF ON MENTIONING IT...BUT MAY NEED TO BE ADDED FOR THE
MORNING HOURS. WILL BE CARRYING A TEMPO GROUP FOR THUNDERSTORMS AT
KAEX IN THE MORNING HOURS.
&&
.PREV DISCUSSION... /ISSUED 943 PM CDT SUN APR 27 2014/
DISCUSSION...
UPDATED THE AREAL DISTRIBUTION OF POPS TO MORE CLOSELY FOLLOW THE
HRR (HIGH RESOLUTION RAPID REFRESH) SOLUTION. OTHERWISE...THE
ZONE PACKAGE IS ON TARGET.
JT
PREV DISCUSSION... /ISSUED 630 PM CDT SUN APR 27 2014/
DISCUSSION...
FOR 00Z TAFS...VFR TO MVFR CONDITIONS EXPECTED THIS EVENING...WITH
GUSTY SOUTH WINDS. NOT EXPECTING THE NEXT ROUND OF PRECIP UNTIL
TOWARDS DAYBREAK...BUT LOW CONFIDENCE ON COVERAGE AT THIS POINT.
PREV DISCUSSION... /ISSUED 436 PM CDT SUN APR 27 2014/
DISCUSSION...
LATEST WATER VAPOR SATELLITE IMAGERY SHOWED A VIGOROUS UPPER LOW
OVER NW KS/SW NE...WITH A VIGOROUS PACIFIC JET NOSING IN FROM THE
PAC NW AND CURLING CYCLONICALLY THROUGH THE BASE OF THE LOW. A
SUBTROPICAL JET WAS NOTED TO THE SOUTH ACROSS CENTRAL MX INTO THE
WRN GULF. KLCH AND KPOE VWPS CONTINUE TO SHOW A 50KT PLUS
SOUTHWESTERLY LLJ.
AT THE SFC...LOW PRESSURE IS HARD TO MISS OVER NW KS...WITH A
TRAILING CDFNT/DRYLINE THROUGH CENTRAL OK/TX.
HARD TO HAVE A GREAT DEAL OF FAITH IN ANY SPECIFIC SHORT TERM
GUIDANCE...AS PRECIOUS FEW CAUGHT THE ISOLATED TO SCATTERED
ELEVATED CONVECTION THAT DEVELOPED THIS AFTERNOON. THE ONLINE SPC
4KM WRF WASNT TOO BAD...AND THE HRRR DID FINALLY CATCH ON. THESE
TWO MODELS...WITH SOME ADDITIONAL SUPPORT FROM GLOBAL
MODELS...DEPICT A BAND OF CONVECTION INITIATING AFTER MIDNIGHT IN
THE VICINITY OF EAST CENTRAL TEXAS NE TWD SHREVEPORT. THE
SOUTHWESTWARD EXTENT OF ANY SUCH DEVELOPMENT IS A BIT
UNCERTAIN...BUT IT IS NOT OUT OF THE QUESTION FOR NORTHERN ZONES
TO BE AFFECTED GIVEN THE THE PROJECTED EAST/NORTHEAST MOVEMENT.
WILL MAINTAIN HIGHEST POPS TONIGHT IN THIS AREA...AND HOLD ONTO
THE SEVERE WORDING.
GENERALLY PRESERVED THE INHERITED INLAND WIND HAZARDS...BUT DID
TWEAK THE MARINE HAZARDS A BIT...EASING OUT OF THE SCA FOR THE
COASTAL LAKES AND BAYS MID EVENING...AND THE INLAND WATERS WEST OF
CAMERON AFTER MIDNIGHT CONCURRENT WITH LATEST PROGS THAT SHOW
WINDS STARTING TO DECREASE FROM WEST TO EAST OVERNIGHT AND INTO
TOMORROW. A WIND ADVISORY MAY STILL BE WARRANTED FOR A TIME ACROSS
SOUTH/EAST CENTRAL LOUISIANA...BUT WILL LET THE OVERNIGHT CREW
MAKE THE CALL ON THAT AS IT LOOKS A LITTLE MORE MARGINAL.
CONVECTIVE PROSPECTS WILL ALSO SHIFT EAST TOMORROW...AS THE
CDFNT PUSHES JUST EAST OF A KSHV TO KLFK LINE BY TOMORROW
AFTERNOON. HAVE GENERALLY LEFT THIS PART OF THE FORECAST AS
IS...STAYING MAINLY WITH LOW TO MID RANGE POPS AND PRESERVING THE
SEVERE WORDING PER SPC DAY 2 CONVECTIVE OUTLOOK.
THE FRONT IS STILL FCST TO PUSH THROUGH THE DURING THE AFTERNOON
AND EVENING HOURS ON TUE...WITH THE SEVERE RISK DISPLACED TO OUR
EAST BY THIS TIME. ALTHOUGH STILL NOT IN IDEAL AGREEMENT...THE GFS
HAS COME A LONG WAY TOWARD THE ECMWF SOLUTION IN DEPICTING
SOUTHWESTERLY FLOW ALOFT...WITH ONE OR MORE FRONTAL WAVES/LOWS
DEVELOPING ALONG THE FRONT. APPEARS THAT THE BEST CHANCE OF ANY
RAIN AFFECTING THE AREA WOULD BE THU NIGHT-FRI...AS BOTH MODELS
DEPICTING A SHORTWAVE TROF PIVOTING THROUGH THE NW GULF COAST
REGION.
MARINE...
GUSTY SOUTH WINDS AND ROUGH SEAS WILL CONTINUE THIS EVENING AS A
LOW PRESSURE SYSTEM DEVELOPS IN THE PLAINS. WINDS WILL BEGIN TO
DIMINISH A BIT OVER THE COASTAL LAKES AND BAYS TONIGHT AND THE
WATERS WEST OF CAMERON LATE TONIGHT INTO TOMORROW. TIDES WILL BE
RUNNING ABOUT ONE FOOT ABOVE NORMAL TODAY AND MONDAY. THE CHANCE
OF SHOWERS AND THUNDERSTORMS WILL ALSO CONTINUE INTO EARLY NEXT
WEEK AS THIS LOW PRESSURE SYSTEM SLOWLY MOVES EAST THROUGH THE
CENTRAL UNTIED STATES...CULMINATING IN A FRONT CROSSING THE REGION
TUESDAY NIGHT. OFFSHORE FLOW WILL PREVAIL IN THE WAKE OF THE FRONT
FOR THE REST OF THE WORK WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 72 84 70 85 57 / 20 30 20 20 20
KBPT 72 84 69 85 58 / 20 20 20 20 10
KAEX 71 85 67 83 53 / 50 50 30 30 10
KLFT 72 84 71 85 58 / 30 40 40 30 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING
ZONES: ACADIA...CALCASIEU...EAST CAMERON...IBERIA...
JEFFERSON DAVIS...LAFAYETTE...LOWER ST. MARTIN...ST. MARY...
UPPER ST. MARTIN...VERMILION...WEST CAMERON.
TX...WIND ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING
ZONES: JEFFERSON...ORANGE.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO
INTRACOASTAL CITY LA OUT 20 NM...WATERS FROM INTRACOASTAL
CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON
LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM.
SMALL CRAFT EXERCISE CAUTION UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: CALCASIEU LAKE...SABINE LAKE.
SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE
FOLLOWING ZONES: VERMILION BAY.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM.
SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM.
&&
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV
WWW.TWITTER.COM/NWSLAKECHARLES
WWW.YOUTUBE.COM/NWSLAKECHARLES
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1250 AM EDT MON APR 28 2014
.SYNOPSIS...
LOW PRESSURE SOUTH OF NOVA SCOTIA WILL CONTINUE MOVING INTO THE
OPEN ATLANTIC TONIGHT INTO MONDAY. HIGH PRESSURE WILL BUILD SOUTH
ACROSS THE REGION MONDAY NIGHT THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1250 AM UPDATE...STARTING TO SEE SHOWERS DEVELOPING OVER
WESTERN/SOUTHERN NEW BRUNSWICK. THIS ACTIVITY WILL CONTINUE TO
MOVE WESTWARD AROUND THE TOP OF THE DEPARTING UPPER LOW. THIS
INFLUX OF MOISTURE HAS PROHIBITED TEMPERATURES FROM DROPPING VERY
MUCH TONIGHT; MOST AREAS ARE STILL IN THE UPPER 30S TO LOWER 40S.
FOR THIS UPDATE, ADJUSTED POPS UP A BIT, ESPECIALLY OVER
WASHINGTON COUNTY AS PER RADAR TRENDS. ALSO RAISED OVERNIGHT LOWS
BY A DEGREE OR TWO ACROSS THE NORTH. NO OTHER CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...
THE CHALLENGE WILL DEFINITELY BE THE TEMPERATURES AND WHERE TO
PLACE RAINFALL CHANCES.
LOW PRES WAS SPINNING SE OF NOVA SCOTIA PER THE 18Z ANALYSIS. SFC
TROUGH EXTENDING OFF THIS LOW EXTENDED BACK EASTERN AND CENTRAL
MAINE. THE FIRST BATCH OF LIGHT RAIN/SHOWERS MOVED SSW EARLY TODAY
AND ANOTHER ROUND IS APPROACHING FROM NEW BRUNSWICK. THE RAIN HAS
BEEN WEAKENING AS IT RUNS INTO DRIER AIR AS SEEN BY THE LATEST
SATELLITE VISIBLE IMAGERY SHOWING BREAKS IN THE CLOUDS. BEST
SUPPORT FOR SUBSTANTIAL RAIN HAS BEEN OVER THE EASTERN SECTIONS OF
WASHINGTON COUNTY. DECENT LLVL CONVERGENCE AND MID LEVEL FORCING
IS THERE AS SEEN BY BOTH THE RAP AND NAM12. EXPECTING THIS TREND
TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. CARRIED CHANCE
POPS(30-50%) FOR THE CWA TONIGHT W/THE HIGHEST CHANCES ACROSS
NORTHERN AND EASTERN SECTIONS. AS ONE TRAVELS FURTHER W AND SW,
SHOWERS WILL WEAKEN DUE TO SUBSIDENCE IN PLACE. CLOUDS WILL HANG
AROUND THROUGHOUT THE NIGHT AND THIS WILL KEEP TEMPERATURES WELL
ABOVE 32F WHICH SHOULD ALLOW FOR ALL LIQUID PRECIP. RAINFALL
AMOUNTS HAVE BEEN LIGHT AND SEE NO SUPPORT FOR THIS TO CHANGE MUCH
OVER THE NEXT 24 HRS. THEREFORE, STAYED W/QPF OF 0.10" OR LESS
THROUGH MONDAY.
CONDITIONS LOOK TO IMPROVE THROUGHOUT THE DAY ON MONDAY AS HIGH
PRES IS FORECAST TO WEDGE DOWN FROM CANADA. SOME SUNSHINE IS
EXPECTED BY MONDAY AFTERNOON ESPECIALLY ACROSS THE NORTHERN AND
EASTERN SECTIONS WHILE THE CENTRAL HIGHLANDS WILL HANG ON TO MORE
CLOUDS. THIS WILL LEAD TO A VARIATION IN TEMPERATURES. DECIDED TO
BOOST DAYTIME HIGHS ON MONDAY UP TO READINGS AOA 50F MAINLY FOR
THE NORTHERN AND EASTERN SECTIONS. CENTRAL AND WESTERN AREAS WILL
HANG W/MORE CLOUDS THUS KEEPING TEMPERATURES DOWN INTO THE 40S
SOMEWHAT SIMILAR TO TODAY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL RIDGE SOUTH ACROSS THE REGION MONDAY NIGHT
THROUGH EARLY WEDNESDAY...THEN BEGIN TO MOVE EAST LATER WEDNESDAY.
CLOUD COVER WILL DECREASE ACROSS THE REGION MONDAY NIGHT. MOSTLY
CLEAR SKIES WILL OCCUR ACROSS THE REGION TUESDAY INTO EARLY
WEDNESDAY. CLOUD COVER WILL THEN BEGIN TO INCREASE LATER
WEDNESDAY...PARTICULARLY ACROSS WESTERN PORTIONS OF THE FORECAST
AREA. TEMPERATURES WILL BE AT NEAR NORMAL...TO SLIGHTLY BELOW
NORMAL...LEVELS TUESDAY/WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UNSETTLED PATTERN WILL TAKE HOLD ONCE AGAIN FOR THE LONG RANGE
AS THE RIDGE BREAKS DOWN AND THE NEXT UPPER LEVEL LOW ADVANCES
TOWARD THE REGION. CLOUDS WILL INCREASE WEDNESDAY NIGHT WITH RAIN
AND SHOWERS DEVELOPING WEST TO EAST FOR THURSDAY AS AN OCCLUSION
MOVES THROUGH AHEAD OF A SURFACE LOW ADVANCING NORTH ALONG THE
COAST. STEADIER RAIN LOOKS TO TAPER OFF THURSDAY NIGHT WITH RAIN
AMOUNTS OF A HALF INCH TO AN INCH POSSIBLE BY THIS TIME. EXPECT
SHOWERS TO LINGER INTO FRIDAY IN ASSOCIATION WITH THE BROAD UPPER
LEVEL LOW SITUATED OVER THE GREAT LAKES BY THIS TIME AND A
LINGERING SURFACE TROUGH.
SOME UNCERTAINTY DEVELOPS IN THE FORECAST FOR THE BEGINNING OF
NEXT WEEKEND. OVERALL, THE UNSETTLED PATTERN REMAINS HOWEVER THE
ECMWF MODEL BRINGS A BRIEF WINDOW OF SOME PARTIAL CLEARING AND
DRYING IN FOR SATURDAY WHILE THE GFS SUGGESTS MORE CLOUDS WITH AT
LEAST A FEW LINGERING SHOWERS. AT THIS POINT WILL KEEP IN THE
CHANCE OF SHOWERS WITH MOSTLY CLOUDY SKIES. A BETTER CHANCE FOR
MORE WIDESPREAD RAIN AND SHOWERS DEVELOPS ONCE AGAIN FOR SATURDAY
NIGHT AND SUNDAY AS THE NEXT SURFACE WAVE ASSOCIATED WITH THE
BROAD UPPER TROUGH DEVELOPS SOUTH OF THE REGION AND MOVES NORTH UP
THE COAST. TEMPERATURES THROUGH THE LONG RANGE ARE FORECAST TO
REMAIN WITHIN A FEW DEGREES OF AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR AT ALL THE TERMINALS AS OF 01Z. EXPECTATION IS
FOR CIGS TO DROP TO MVFR ACROSS ALL THE TERMINALS OVERNIGHT. A
PERIOD OF IFR IS POSSIBLE LATE TONIGHT(AFT 08Z) AND THIS WILL
MAINLY BE FOR THE NORTHERN TERMINALS. DECIDED TO STAY W/MVFR
THROUGH MIDDAY MONDAY. AN IMPROVEMENT TO VFR IS EXPECTED BY MON
EVENING.
SHORT TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE REGION MONDAY
NIGHT THROUGH WEDNESDAY. VFR WEDNESDAY NIGHT WILL GIVE WAY TO
MVFR AND THEN IFR THURSDAY AS RAIN MOVES IN FROM WEST TO EAST.
MVFR/IFR CONDITIONS ARE LIKELY TO PERSIST INTO FRIDAY DUE TO LOW
STRATUS WITH LINGERING SHOWERS.
&&
.MARINE...
NEAR TERM: NO SCA ATTM. LATEST MODEL GUIDANCE HAS BEEN RUNNING TOO
HIGH FOR THE WINDS AND ADJUSTMENTS WERE MADE TO PUSH THE SPEEDS
BACK. THE WIND WILL GRADUALLY INCREASE OVER THE NEXT 24 HOURS AND
THE SEAS WILL SLOWLY BUILD. A SCA MAY BE NEEDED BY LATE MONDAY.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE ON THE
WATERS MONDAY NIGHT INTO EARLY TUESDAY NIGHT. CONDITIONS ARE
EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS LATER TUESDAY
NIGHT INTO WEDNESDAY. SCA CONDITIONS WILL BE POSSIBLE THURSDAY AS
SE WINDS STRENGTHEN AND WAVE HEIGHTS INCREASE AHEAD OF AN
OCCLUSION MOVING THROUGH WHICH WILL ALSO BRING RAIN AND THE
POTENTIAL FOR FOG. THESE CONDITIONS IMPROVE FOR FRIDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...NORCROSS
LONG TERM...FITZSIMMONS
AVIATION...HASTINGS/HEWITT/NORCROSS
MARINE...HASTINGS/HEWITT/NORCROSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 511 AM EDT MON APR 28 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH FROM THE NW CONUS THROUGH THE CENTRAL PLAINS WITH A
CLOSED LOW OVER NEBRASKA. DOWNSTREAM A RIDGE EXTENDED FROM THE SE
CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY
FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON
BAY AND A DEEP LOW OVER ERN NEBRASKA. ISENTROPIC ASCENT AS NOTED ON
THE 295K SFC HAS PRODUCED SEVERAL BANDS OF LIGHT PCPN OVER UPPER MI
THIS MORNING BUT THIS PCPN HAS FALLEN MAINLY AS JUST
SPRINKLES/FLURRIES AS IT ENCOUNTERS VERY DRY AIR BELOW 750 MB.
TODAY...MODELS CONSISTENT SHOWING SYSTEM OVER ERN NEBRASKA STALLING
AND BEGINNING TO OCCLUDE TODAY. MODELS SHOW WEAKENING ISENTROPIC
ASCENT OVER UPR MI AND A LACK OF 850-700 MB MOISTURE ADVECTION INTO
THE REGION. THIS FACT ALONG WITH MID-LVL RDG GENERALLY STAYING IN
PLACE SHOULD KEEP MUCH OF THE CWA DRY TODAY. INCREASING 850-700 MB
MOISTURE ADV AND ISENTROPIC ASCENT COULD BRING IN A BETTER CHC OF
RAIN TOWARD 00Z THIS EVENING OVER MAINLY FAR SCNTRL CWA.
TONIGHT...MODELS SHOW MORE SUBSTANTIAL SHORTWAVE LOBE ROTATING
NORTHWARD AHEAD OF PLAINS CLOSED LOW WHICH IN TURN WILL PROPEL 850
MB WARM FRONT NORTHWARD INTO THE SE CWA LATE TONIGHT. INCREASING
ISENTROPIC ASCENT AND 850-700 MB MOISTURE ADVECTION SPREADING IN
FROM THE SSE AHEAD OF THE WARM FRONT WILL BRING INCREASING RAIN CHCS
INTO SCNTRL CWA THIS EVENING SPREADING INTO THE REST OF THE SE HALF
OF THE CWA OVERNIGHT TONIGHT. THICKNESS VALUES AND SOUNDINGS SUGGEST
SNOW MAY MIX WITH RAIN OVER NCNTRL AND NW CWA LATE TONIGHT BUT PCPN
SHOULD BE LIGHT THAT ANY SNOW AMTS WILL HAVE LITTLE IMPACT ON TRAVEL.
MODEL QPF INDICATES SCNTRL CWA COULD SEE FROM .25 TO PERHAPS .75 OF
AN INCH OF RAINFALL TONIGHT WHICH WILL ADD TO RUNOFF FOR AREA STREAMS
AND RIVERS INTO MIDWEEK.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM EDT MON APR 28 2014
FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT
PRECIP IS EXPECTED DURING THAT TIME.
THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A
DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE
W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE
LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER
LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED
UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND
THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE
WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH
IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY
50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN
THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC
SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO
DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR
GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING
MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA
TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM.
ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS
THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT
QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP
SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE
IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT
PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF
NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES.
WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM
/WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT
TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE
MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM
IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME
FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN
UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE
TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS
THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE
MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER
MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS
TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING
ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA
RIVERS.
ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE
SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND
BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND
TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL
BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE
MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE
PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP
DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING
THIS PERIOD.
THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE
WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE
THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT
AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD UNDER MID CLOUDS.
E-NE WINDS COULD GUST NEAR 25 KT AT ALL TAF SITES AS PRES GRADIENT
TIGHTENS AHEAD OF LOW PRES OVER THE CENTRAL PLAINS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EDT MON APR 28 2014
EAST TO NORTHEAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE
DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER MUCH OF WRN
LAKE SUPERIOR INTO TUE MORNING. THERE IS ALSO A CHANCE FOR ENE GALES
TO 35 KNOTS OVER CENTRAL LAKE SUPERIOR FOR LATE TONIGHT INTO TUE SO
HAVE ISSUED A GALE WATCH FOR LSZ264-266 WINDS SHOULD GRADUALLY
DIMINISH LATE TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE EVENING. WINDS ARE
EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO FRI AS THE
LOW FILLS AND REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 358 AM EDT MON APR 28 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER
NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT
EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL
START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND
WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID
EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY
THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE
WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE
FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER
QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
LSZ264>266.
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ TUESDAY FOR LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...07/JV
MARINE...VOSS
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 AM EDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 432 PM EDT SUN APR 27 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH THROUGH THE NW CONUS WITH A LOW OVER WRN KS AND A
DOWNSTREAM RIDGE FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA.
AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES
BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER NW KS. AN
INITIAL BAND OF LIGHT PCPN WAS PRODUCING MAINLY JUST SPRINKLES INTO
THE FAR WRN CWA NEAR IWD AS IT ENCOUNTERS THE VERY DRY LAYER BELOW
750 MB. HOWEVER...A MORE SUBSTANTIAL AREA OF RAIN OVER WRN INTO N
CNTRL WI...SUPPORTED BY 300K ISENTROPIC LIFT WAS LIFTING TOWARD
UPPER MI.
TONIGHT...RADAR TRENDS AND SHORT TERM MODELS SUGGEST THAT SOME LIGHT
SHOWERS WILL MOVE INTO THE WEST LATE THIS AFTERNOON AND EVENING.
HOWEVER...THERE IS A LOWER CHANCE THAT THERE WILL BE MEASURABLE PCPN
GIVEN THE AMOUNT OF DRY AIR TO OVERCOME WITH THE ERLY LOW LEVEL
INFLOW. FARTHER TO THE EAST...OVER S CNTRL UPPER MI...THE DRY
AIR...PER 12Z APX SOUNDING...SHOULD BE MORE EFFECTIVE AT SLOWING THE
ADVANCE AND REDUCING PCPN CHANCES. WITH EVAPORATIVE COOLING AT THE
LEADING EDGE OF THE PCPN...SOME SNOW OR SLEET MAY ALSO MIX IN WITH THE
RAIN LATE THIS EVENING AND OVERNIGHT...PER NAM LOW LEVEL THICKNESS
AND WET-BULB ZERO HEIGHTS.
MON...THE MODELS WERE IN SLIGHTLY BETTER AGREEMENT IN HANDLING THE
ADVANCE OF PCPN INTO UPPER MICHIGAN. THE NAM/GFS/ECMWF WERE NOW ON
THE SLOWER SIDE COMPARED TO GEM. AS THE MID/UPPER LEVEL LOW SLOWLY
WOBBLES TO THE NORTHEAST AND AN ELONGATED TROUGH/FRONT EXTENDS FROM
SRN IA INTO NRN INDIANA. ANOTHER BAND OF RAIN WILL MOVE TOWARD UPPER
MI WITH INCREASING 300K-305K ISENTROPIC ASCENT NORTH OF THE 850 MB
WARM FRONT THROUGH CNTRL WI. THERE IS STILL LIKELY TO BE SHARP
CUTOFF TO THE NRN EDGE OF THE PCPN BAND THROUGH CNTRL UPPER MI. THE
HIGHEST CHANCES WILL REMAIN ALONG THE WI BORDER WITH ONLY A SLIGHT
CHANCE OVER THE NORTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM EDT MON APR 28 2014
FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT
PRECIP IS EXPECTED DURING THAT TIME.
THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A
DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE
W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE
LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER
LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED
UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND
THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE
WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH
IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY
50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN
THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC
SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO
DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR
GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING
MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA
TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM.
ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS
THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT
QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP
SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE
IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT
PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF
NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES.
WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM
/WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT
TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE
MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM
IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME
FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN
UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE
TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS
THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE
MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER
MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS
TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING
ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA
RIVERS.
ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE
SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND
BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND
TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL
BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE
MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE
PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP
DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING
THIS PERIOD.
THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE
WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE
THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT
AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD UNDER MID CLOUDS.
E-NE WINDS COULD GUST NEAR 25 KT AT ALL TAF SITES AS PRES GRADIENT
TIGHTENS AHEAD OF LOW PRES OVER THE CENTRAL PLAINS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT SUN APR 27 2014
EAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER
THE PLAINS. EXPECT ENE GALES TO 35KTS OVER WESTERN LK SUPERIOR
TOWARD DULUTH INTO TUE MORNING. EAST GALES ARE THEN EXPECTED LATE
TONIGHT INTO MON OVER THE REST OF THE WESTERN LAKE. WINDS WILL
GRADUALLY DIMINISH TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE. WINDS ARE EXPECTED TO
DROP OFF TO 25 KNOTS OR LESS FROM WED INTO THU AS THE LOW FILLS AND
REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 358 AM EDT MON APR 28 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER
NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT
EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL
START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND
WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID
EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY
THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE
WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE
FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER
QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 11 AM EDT /10 AM CDT/ TUESDAY FOR LSZ162.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07/JV
MARINE...JLB
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
132 AM EDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 432 PM EDT SUN APR 27 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH THROUGH THE NW CONUS WITH A LOW OVER WRN KS AND A
DOWNSTREAM RIDGE FROM THE SE CONUS THROUGH WRN LAKES INTO MANITOBA.
AT THE SFC...A BRISK ERLY FLOW PREVAILED THROUGH THE NRN LAKES
BETWEEN HIGH PRES OVER HUDSON BAY AND A DEEP LOW OVER NW KS. AN
INITIAL BAND OF LIGHT PCPN WAS PRODUCING MAINLY JUST SPRINKLES INTO
THE FAR WRN CWA NEAR IWD AS IT ENCOUNTERS THE VERY DRY LAYER BELOW
750 MB. HOWEVER...A MORE SUBSTANTIAL AREA OF RAIN OVER WRN INTO N
CNTRL WI...SUPPORTED BY 300K ISENTROPIC LIFT WAS LIFTING TOWARD
UPPER MI.
TONIGHT...RADAR TRENDS AND SHORT TERM MODELS SUGGEST THAT SOME LIGHT
SHOWERS WILL MOVE INTO THE WEST LATE THIS AFTERNOON AND EVENING.
HOWEVER...THERE IS A LOWER CHANCE THAT THERE WILL BE MEASURABLE PCPN
GIVEN THE AMOUNT OF DRY AIR TO OVERCOME WITH THE ERLY LOW LEVEL
INFLOW. FARTHER TO THE EAST...OVER S CNTRL UPPER MI...THE DRY
AIR...PER 12Z APX SOUNDING...SHOULD BE MORE EFFECTIVE AT SLOWING THE
ADVANCE AND REDUCING PCPN CHANCES. WITH EVAPORATIVE COOLING AT THE
LEADING EDGE OF THE PCPN...SOME SNOW OR SLEET MAY ALSO MIX IN WITH THE
RAIN LATE THIS EVENING AND OVERNIGHT...PER NAM LOW LEVEL THICKNESS
AND WET-BULB ZERO HEIGHTS.
MON...THE MODELS WERE IN SLIGHTLY BETTER AGREEMENT IN HANDLING THE
ADVANCE OF PCPN INTO UPPER MICHIGAN. THE NAM/GFS/ECMWF WERE NOW ON
THE SLOWER SIDE COMPARED TO GEM. AS THE MID/UPPER LEVEL LOW SLOWLY
WOBBLES TO THE NORTHEAST AND AN ELONGATED TROUGH/FRONT EXTENDS FROM
SRN IA INTO NRN INDIANA. ANOTHER BAND OF RAIN WILL MOVE TOWARD UPPER
MI WITH INCREASING 300K-305K ISENTROPIC ASCENT NORTH OF THE 850 MB
WARM FRONT THROUGH CNTRL WI. THERE IS STILL LIKELY TO BE SHARP
CUTOFF TO THE NRN EDGE OF THE PCPN BAND THROUGH CNTRL UPPER MI. THE
HIGHEST CHANCES WILL REMAIN ALONG THE WI BORDER WITH ONLY A SLIGHT
CHANCE OVER THE NORTH.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 432 PM EDT SUN APR 27 2014
UPPER LOW OVER THE CENTRAL PLAINS MONDAY AFTERNOON AND ASSOCIATED
SFC LOW AND WARM FRONT WILL BE MAIN FOCUS FOR THE FORECAST THIS
UPCOMING WEEK. MODELS VERY LOCKED INTO IDEA THAT WHILE WIDESPREAD
SHRA AND TSRA AND SEVERE WEATHER IMPACT MID TO LOWER MISSISSIPPI
RIVER VALLEY...ADDITIONAL SHRA/TSRA DEVELOP LATE MONDAY AFTN ALONG
WARM FRONT EXTENDING TO THE EAST OF SFC LOW OVER NEB. THIS IS IN
RESPONSE TO SHORTWAVE/PV ANAMOLY LIFTING AHEAD OF PARENT UPPER LOW.
POSSIBLE THAT ADDITIONAL SHRA WILL ALREADY BE LIFTING TOWARD UPR
MICHIGAN AS WELL DUE TO REMNANTS OF SHRA/TSRA DEVELOPING OVER THE
UPPER MISSISSIPPI RIVER VALLEY MONDAY MORNING PER SSW-NNE ORIENTED
FORWARD PROPAGATING CORFIDI VECTORS AND H85-H7 MOSITURE TRANSPORT.
AREA OF SHRA/TSRA ALONG WARM FRONT WILL GLIDE TOWARD UPR MICHIGAN
OVERNIGHT INTO TUESDAY MORNING DUE TO THE ARRIVAL OF SHORTWAVE AND
H85-H5 Q-VECTOR CONVERGENCE ALONG WITH VEERING H85-H7 FLOW FM ESE
TO MORE SSW. FOLLOWING THE Q-VECTOR CONVERGENCE AND RIBBON OF
MOISTURE TRANSPORT...EXPECT MOST PRECIPITATION TO OCCUR IN THE
MORNING. BASED ON 1000-850MB THICKNESSES/H85 TEMPS AND HEIGHT OF
WBZERO...MAY SEE SNOW OR A RAIN/SNOW MIX OVER HIGHER TERRAIN OF
WEST AND NCNTRL UPR MICHIGAN PERHAPS EVEN LINGERING INTO MID AFTN.
MINOR SNOW ACCUMULATIONS SEEM POSSIBLE...ESPECIALLY ON GRASSY
SURFACES. WILL LEAVE OUT OF HAZARDOUS WEATHER OUTLOOK FOR NOW AS
TRAVEL WOULD PROBABLY BE ONLY MINIMALLY IMPACTED. BY LATE
AFTN...EXPECT CHANGE OVER TO RAIN AS H85 TEMPS SURGE ABOVE ZERO.
THIS MAY BE OCCURRING WHEN MAJORITY OF HEAVIER PRECIPITATION IS
COMING TO AN END THOUGH. BY TUE EVENING...FORECAST SOUNDINGS SHOW
DRYING ABOVE H9...SO THERE MAY BE DRIZZLE. TEMPS WILL CONTINUE TO
RISE SFC-H85 SO BY THAT TIME WILL ONLY BE DEALING WITH LIQUID PRECIP.
ON WEDNESDAY...PRIMARY SHORTWAVE LIFTS NORTH ACROSS THE UPPER GREAT
LAKES. SEEMS TO BE A TREND FOR BEST MOISTURE TRANSPORT TO MISS UPR
MICHIGAN TO THE EAST...ALLOWING BULK OF RAIN ON WEDNESDAY TO SURGE
NORTH ACROSS THE LOWER LAKES. HOWEVER...SIGNAL THAT HIGHER THETA-E
AT H8-H7 WILL BE WRAPPING WESTWARD ACROSS UPR MICHIGAN ON CYCLONIC
NORTH SIDE OF FILLING SFC-H85 LOWS. RAIN ON WEDNESDAY WOULD ONLY BE
BOLSTERED OVER HIGHER TERRAIN OF WESTERN AND NORTH CENTRAL UPPER
MICHIGAN WITH NE BLYR WINDS. WEDNESDAY NIGHT INTO THURSDAY...THE
VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS NEARLY STATIONARY
OVER THE UPPER GREAT LAKES. UNSETTLED WEATHER PATTERN AND WILL KEEP
WITH THE CHANCES THAT CONSENSUS OF MODELS SHOWS. THE GREATEST
CHANCES OF RAIN WILL BE ALONG AND NORTH AND WEST OF H85 LOW WHERE
HIGHER THETA-E CONTINUES TO WRAP AROUND THE LOW AND ALSO WHERE
LINGERING Q-VECTOR CONVERGENCE IS LOCATED. YET...CANNOT RULE OUT
PRECIP JUST ABOUT ANYWHERE OVER THE CWA AS OTHER SHORTWAVES WILL
PROBABLY BE CYCLING AROUND THE MAIN UPPER LOW CENTER AND THERE
SHOULD BE PLENTY OF LOW-MID LEVEL MOISTURE REMAINING OVER REGION.
DO NOT EXPECT THE PRECIP THAT OCCURS BEYOND WEDNESDAY EVENING TO
BE HEAVY AS RICHER MOISTURE WILL BE HEADING WELL TO THE EAST OF
THE REGION BY THAT TIME. GRADUALLY COOLING TEMPERATURES ALOFT AND
EVENTUALLY AT THE SFC /H85 TEMPS DROPPING BLO 0C PER GFS/ECMWF/
COULD RESULT IN MIXED RAIN AND SNOW OVER PORTIONS OF CWA LATER
WEDNESDAY NIGHT INTO THURSDAY MORNING AND AGAIN THURSDAY NIGHT INTO
FRIDAY MORNING. MAY EVEN SEE MIX LATER FRIDAY NIGHT INTO SATURDAY
MORNING. ONLY SLIGHT CHANCES FOR POPS BY THAT TIME THOUGH AS
SYSTEM WILL BE UNRAVELLING AS IT LIFTS EAST AND NORTH AWAY FM LK
SUPERIOR/UPR MICHIGAN.
UPPER LEVEL TROUGH STILL FORECAST OVER THE REGION NEXT WEEKEND...SO
NO WARM UP IS IN STORE. COULD BE MORE RAIN/SNOW BY NEXT SUNDAY AS
THERE ARE HINTS OF STRONGER SYSTEM WORKING THROUGH AT THAT TIME.
HOWEVER...SINCE THE TIMING FOR THAT SYSTEM WILL BE COMPLETELY
DICTATED BY THE UPPER LOW THIS WEEK AND HOW QUICK IT DEPARTS...THERE
IS CONSIDERABLE UNCERTAINTY IN HOW ALL THESE DETAILS WILL EVENTUALLY
WORK OUT. THUS...CHANGES TO MODEL CONSENSUS BEYEOND THURSDAY WERE
MINIMAL GIVEN THE UNCERTAINTY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD UNDER MID CLOUDS.
E-NE WINDS COULD GUST NEAR 25 KT AT ALL TAF SITES AS PRES GRADIENT
TIGHTENS AHEAD OF LOW PRES OVER THE CENTRAL PLAINS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT SUN APR 27 2014
EAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE DEEPENS OVER
THE PLAINS. EXPECT ENE GALES TO 35KTS OVER WESTERN LK SUPERIOR
TOWARD DULUTH INTO TUE MORNING. EAST GALES ARE THEN EXPECTED LATE
TONIGHT INTO MON OVER THE REST OF THE WESTERN LAKE. WINDS WILL
GRADUALLY DIMINISH TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE. WINDS ARE EXPECTED TO
DROP OFF TO 25 KNOTS OR LESS FROM WED INTO THU AS THE LOW FILLS AND
REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 432 PM EDT SUN APR 27 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS...AND THE STURGEON
RIVER NEAR NAHMA JUNCTION IN DELTA COUNTY. AT LEAST THROUGH MONDAY
NONE OF THESE RIVERS ARE EXPECTED TO REACH FLOOD STAGE...BUT THESE
AND OTHER RIVERS MAY START TO RISE AGAIN LATER THIS WEEK AS A LOW
PRESSURE SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN.
TOTAL LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2
INCHES BY LATE THIS WEEK. THE PRECIPITATION WOULD ADD TO THE FLOOD
RISK...ESPECIALLY OVER THE NORTHWEST HALF OF UPPER MICHIGAN WHERE
SNOWMELT WILL ALSO ADD TO THE RUNOFF.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
WIDESPREAD FLOODING IS NOT FORESEEN AT THIS TIME. HOWEVER...THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER
LEVELS THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 11 AM EDT /10 AM CDT/ TUESDAY FOR LSZ162.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07/JV
MARINE...JLB
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
342 AM CDT Mon Apr 28 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 152 AM CDT Mon Apr 28 2014
Latest HRRR weakens most of the convection currently across our
forecast area, or shifts it southeast of the region by 12z Monday.
There may be a brief lull in the convection early this morning, then
new convection should break out late this morning and early this
afternoon from Edina to Quincy and south through the St Louis metro
area to the FAM area, then shift eastward through our IL counties
later this afternoon. This will occur as a shortwave ejects out of
the southern Plains into southeast MO and a cold front/dry line
surges eastward into eastern MO by 00z Tue. Should have CAPEs up to
2000-2500 J/Kg ahead of the cold front around 18z Monday with
surface LI values down to around -10. Strongest low-mid level wind
shear should be across southeast MO and southwest IL with strong
500 mb wind max moving through AR into portions of southeast MO,
southern IL, and western portions of TN and KY. The severe weather
threat should be over the eastern portion of our area, in portions
of west central and southwest IL with the primary threat being large
hail and damaging winds. This will occur from the late morning,
through the afternoon and into the early evening hours.
GKS
.LONG TERM: (Tonight through Sunday)
Issued at 341 AM CDT Mon Apr 28 2014
The showers and thunderstorms should be confined to areas east of
the Mississippi River this evening and should be weakening by late
evening as the higher surface dewpoints and instability shifts east
of our forecast area. Little if any precipitation should be left
late tonight. Temperatures will be cooler tonight due to low level
cold air advection in our area south of the upper level and
associated surface low. More showers and a few thunderstorms on
Tuesday as the moisture wraps around the slow moving upper/surface
low north of our area. The best chance for rain will be across the
northwest half of our forecast area. The models keep the showers
going Tuesday night as shortwaves rotate around the mid-upper level
low. The gradual cooling trend will continue with well below normal
temperatures for Wednesday and Wednesday night. The GFS and ECMWF
models drop the zero degree C 850 mb isotherm southeastward into our
forecast area Tuesday night or Wednesday, the cooler NAM even
earlier. Although there will likely be rain across our area again
on Wednesday it should be on the light side. The rain should be
mainly diurnal on Thursday and Friday and favor the northern portion
of our forecast area as the upper level low weakens and moves into
the Great Lakes region. Will see warmer high temperatures for the
weekend as the upper level heights begin to rise and southerly
surface/low level flow returns Saturday night. Low-mid level warm
air advection ahead of a weak shortwave and associated surface low
may bring showers to the extreme northern portion of our forecast
area late Saturday night and Sunday.
GKS
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1147 PM CDT Sun Apr 27 2014
Back edge of storms slowly making their way east. Precipitation
should come to an end at KCOU by taf issuance time. As for rest of
taf sites, kept mention of showers and thunderstorms through about
08z Monday. Mvfr/ifr cigs/vsbys expected with the heavier
activity, otherwise vfr conditions to prevail. Next round of
activity will be with main cold front later today, though they
will fire up just east of KCOU, so kept them dry. As for rest of
taf sites, added vcnty TS mention after 17z then coming to an end
by 23z. As for winds, to prevail from the southeast to south
before veering to the southwest behind the cold front. Could see
winds pickup by 17z with gusts to near 25 kts at times before
diminishing this evening.
Specifics for KSTL:
Back edge of storms slowly making their way east. Precipitation
should come to an end through about 08z. Mvfr/ifr cigs/vsbys
expected with the heavier activity, otherwise vfr conditions to
prevail. Next round of activity will be with main cold front later
today, so added vcnty TS mention after 17z then coming to an end
by 23z. As for winds, to prevail from the southeast to south
before veering to the southwest behind the cold front. Could see
winds pickup by 17z with gusts to near 25 kts at times before
diminishing this evening.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
154 AM CDT Mon Apr 28 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 152 AM CDT Mon Apr 28 2014
Latest HRRR weakens most of the convection currently across our
forecast area, or shifts it southeast of the region by 12z Monday.
There may be a brief lull in the convection early this morning, then
new convection should break out late this morning and early this
afternoon from Edina to Quincy and south through the St Louis metro
area to the FAM area, then shift eastward through our IL counties
later this afternoon. This will occur as a shortwave ejects out of
the southern Plains into southeast MO and a cold front/dry line
surges eastward into eastern MO by 00z Tue. Should have CAPEs up to
2000-2500 J/Kg ahead of the cold front around 18z Monday with
surface LI values down to around -10. Strongest low-mid level wind
shear should be across southeast MO and southwest IL with strong
500 mb wind max moving through AR into portions of southeast MO,
southern IL, and western portions of TN and KY. The severe weather
threat should be over the eastern portion of our area, in portions
of west central and southwest IL with the primary threat being large
hail and damaging winds. This will occur from the late morning,
through the afternoon and into the early evening hours.
GKS
.LONG TERM: (Monday through Next Sunday)
Issued at 355 PM CDT Sun Apr 27 2014
Mon...Thunderstorms are expected to develop on Mon ahead of
the approaching cold front/dryline. Favorable environmental
parameters for severe weather include H7-H5 lapse rates of 7-8 deg
C/km, 0-6km bulk shear of 40-70 kts, and at least 1000 J/kg of
CAPE. The greatest threat appears to be across the eastern half of
the CWA during the afternoon hours when this area will be beneath
the left exit region of an upper jet streak.
Tue through Thu...With cold temperatures aloft creating steep lapse
rates, cyclonic flow aloft, multiple shortwaves rotating through the
trough, and fairly low freezing levels, this looks like a good
pattern for diurnally-driven afternoon SHRA/TSRA with small hail.
Pcpn coverage should diminish quickly after sunset each day. Expect
daily temperatures to be 10-15 degrees cooler than average during
this period.
Fri through Sat...Although the approximate center of the large
upper low is forecast to have moved north and east of MO/IL by
Fri, models show that a broad trough remains in place with several
shortwaves moving through the flow. These disturbances could
support SHRA/TSRA at times.
Kanofsky
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1147 PM CDT Sun Apr 27 2014
Back edge of storms slowly making their way east. Precipitation
should come to an end at KCOU by taf issuance time. As for rest of
taf sites, kept mention of showers and thunderstorms through about
08z Monday. Mvfr/ifr cigs/vsbys expected with the heavier
activity, otherwise vfr conditions to prevail. Next round of
activity will be with main cold front later today, though they
will fire up just east of KCOU, so kept them dry. As for rest of
taf sites, added vcnty TS mention after 17z then coming to an end
by 23z. As for winds, to prevail from the southeast to south
before veering to the southwest behind the cold front. Could see
winds pickup by 17z with gusts to near 25 kts at times before
diminishing this evening.
Specifics for KSTL:
Back edge of storms slowly making their way east. Precipitation
should come to an end through about 08z. Mvfr/ifr cigs/vsbys
expected with the heavier activity, otherwise vfr conditions to
prevail. Next round of activity will be with main cold front later
today, so added vcnty TS mention after 17z then coming to an end
by 23z. As for winds, to prevail from the southeast to south
before veering to the southwest behind the cold front. Could see
winds pickup by 17z with gusts to near 25 kts at times before
diminishing this evening.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1227 AM CDT MON APR 28 2014
.SYNOPSIS...
ISSUED AT 407 PM CDT SUN APR 27 2014
A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS
THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN
CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS.
DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE
EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE
SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT
EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED
NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA
PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO
MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND
70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN
NEBRASKA...WHERE IT TURNED SOUTHEAST INTO SOUTH CENTRAL NEBRASKA.
THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE
TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER
DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND
NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL
SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE
AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING
THE MAIN SEVERE THREAT.
&&
.UPDATE...
ISSUED AT 1225 AM CDT MON APR 28 2014
CURRENT UPDATE TO ACCOUNT FOR SNOW INTO PERKINS COUNTY. LAYING
DOWN SOME SNOW ON NDOR CAMERAS.
UPDATE ISSUED AT 1027 PM CDT SUN APR 27 2014
THE HIGH WIND WATCH HAS BEEN UPGRADED TO A HIGH WIND WARNING BASED
ON THE RAP AND 00Z NAM MODEL RUNS WHICH KEEP THE STRONGEST WINDS
ALONG HIGHWAY 61. THE AREA TO WATCH IS THE CENTRAL SANDHILLS WHERE
THE RAP AND NAM SHOW VERY STRONG 500M AGL WINDS APPROACHING 40 MPH
AT THE SFC MONDAY AFTERNOON.
NOTE THE FORECAST CONTINUES STRONG OR HIGH WINDS MONDAY NIGHT AND
TUESDAY WHICH WOULD NECESSITATE EXTENSIONS OF THE ON GOING HIGH
LIGHTS.
UPDATE ISSUED AT 837 PM CDT SUN APR 27 2014
A LOOK AT THE NEBRASKA DOR CAMS AND THE RAP MODEL SUGGEST WINTER
WEATHER ADVISORY CONDITIONS ACROSS SHERIDAN AND WESTERN CHERRY
COUNTIES. THE RAP INDICATES SEVERAL INCHES OF WET SNOW THIS
EVENING WHICH TAPERS OFF OR MIXES WITH RAIN AFTER MIDNIGHT. RADAR
INDICATES A DEFORMATION ZONE UNDERWAY ACROSS THIS AREA BUT MAINLY
ACROSS NRN SHERIDAN COUNTY. A WINTER ADVISORY IS IN PLACE FOR
THESE AREA AND IT OPERATES UNTIL 13Z.
THE FORECAST UPDATE FOLLOWS 50 PERCENT OF THE 23Z RAP AND 50
PERCENT OF THE PREVIOUS FORECAST. THE PTYPE USES THE RAP MODEL
WHICH SPREADS WET SNOW AS FAR SOUTH AS DEUEL COUNTY BUT LITTLE
ACCUMULATION IS EXPECTED THAT FAR SOUTH. IT LOOKS LIKE THE FAVORED
AREA FOR SNOW IS NORTHWEST NEBRASKA...NORTH OF THE NORTH PLATTE
VALLEY FOLLOWING THE H750 MB FRONT WHICH IS STRONGLY STACKED AND
MOVING VERY SLOWLY EAST TONIGHT. NOTE THE 23Z RAP PRODUCES OVER 1
INCH OF QPF ACROSS SHERIDAN COUNTY TONIGHT. THE FORECAST USES A
RATIO OF 6 TO 1 FOR 3 TO NEARLY 8 INCHES OF SNOW FAVORING PINE
RIDGE.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 407 PM CDT SUN APR 27 2014
FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN
LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL.
THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH
THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK.
WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST
KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE
TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND
OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE
CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS
STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW.
THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY
00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO
AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z
NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE
CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE
OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF
THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS
OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE
TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD
DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS
COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG
QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN
TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP
BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS
ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY
THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT
WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN
ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER
COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET
DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE
WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO
SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2
INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE.
THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND
THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED
THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE
SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO
CIRCULATE AROUND THE SYSTEM.
MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON
THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN
ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND
ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT
PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL
LOOK LIKELY.
WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER
THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A
NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY
MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO
SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF
HEADLINES ARE NEEDED.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 407 PM CDT SUN APR 27 2014
TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND
PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL
LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER
MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO
PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING
THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA
MONDAY NIGHT AND TUESDAY NIGHT.
FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN
FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL
MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY
LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN
PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS
IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND
SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND
DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID
CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY
WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN
THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT
AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND
WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE
CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS
WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY
CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL
HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE
IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE
FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE.
LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE
MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN
WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS
TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE
WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH
LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS
AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL
CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE
FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET
UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON
HOURS.
ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME
IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND
NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE
OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY
MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT
DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR
MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON
ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT
ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER
CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO
CATEGORICAL POPS OVERNIGHT.
TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON
TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY
THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL
CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL
DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR
TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL
HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C
IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL
STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85
TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST.
AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS
WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30
MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT
ANTICIPATING ANY WIND HEADLINES ATTM.
WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED
BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK.
HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL
CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN
THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH
THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE
50S EXPECTED FRIDAY...SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1141 PM CDT SUN APR 27 2014
WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH
MONDAY EVENING AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL
PLAINS. WINDS 32035G45KT SHOULD REDEVELOP MONDAY MORNING AND SPREAD
FROM WEST TO EAST THROUGH MONDAY AFTN. WINDS SUBSIDE AROUND SUNSET.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 7 AM CDT /6 AM MDT/ THIS MORNING TO 7 PM
CDT /6 PM MDT/ THIS EVENING FOR NEZ022-035-056>058-069-070.
WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ THIS MORNING FOR NEZ022-
035-056>058-069-070.
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ004-
023>025-036-037-059-071-094.
WINTER WEATHER ADVISORY UNTIL 7 AM MDT MONDAY FOR NEZ004-094.
WIND ADVISORY FROM 7 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR NEZ005-006-008-009-026-027-038.
&&
$$
UPDATE...POWER
SYNOPSIS...CLB
SHORT TERM...BROOKS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1143 PM CDT SUN APR 27 2014
.SYNOPSIS...
ISSUED AT 407 PM CDT SUN APR 27 2014
A POTENT...UPPER LEVEL LOW WAS CENTERED OVER WESTERN KS
THIS AFTERNOON. A NICE JET STREAK EXTENDED FROM NORTHERN
CALIFORNIA...AROUND THE BASE OF THE LOW...NOSING INTO CENTRAL KS.
DOWNSTREAM OF THE TROUGH...A HIGH AMPLITUDE...NEGATIVE TILTED RIDGE
EXTENDED FROM THE SERN STATES INTO NRN MANITOBA. AT THE
SURFACE...LOW PRESSURE WAS NOTED OVER GOODLAND KS WITH A COLD FRONT
EXTENDING SSW INTO NERN NEW MEXICO. AN INVERTED TROUGH AXIS EXTENDED
NORTH OF THE LOW ALONG THE COLORADO/KS BORDER INTO THE NEBRASKA
PANHANDLE. WEST OF THIS INVERTED TROUGH...TEMPS WERE IN THE LOWER TO
MID 40S...WHILE EAST OF THE TROUGH AXIS...TEMPS WERE IN THE 60S AND
70S. A DRY LINE...EXTENDED NORTH OF THE SURFACE LOW INTO SWRN
NEBRASKA...WHERE IT TURNED SOUTHEAST INTO SOUTH CENTRAL NEBRASKA.
THUNDERSTORMS HAVE FIRED ALONG THE DRYLINE THIS AFTERNOON WITH THE
TORNADIC THREAT GENERALLY IN SOUTH CENTRAL NEBRASKA WHERE BETTER
DIRECTIONAL SHEAR EXISTS. FURTHER NORTH ACROSS THE CENTRAL AND
NORTHERN SANDHILLS...GOOD SPEED SHEAR EXISTS...HOWEVER DIRECTIONAL
SHEAR IS LACKING PER LATEST KLNX VAD WIND PROFILER. IN THESE
AREAS...STRONG TO SEVERE STORMS HAVE OCCURRED WITH LARGE HAIL BEING
THE MAIN SEVERE THREAT.
&&
.UPDATE...
ISSUED AT 1027 PM CDT SUN APR 27 2014
THE HIGH WIND WATCH HAS BEEN UPGRADED TO A HIGH WIND WARNING BASED
ON THE RAP AND 00Z NAM MODEL RUNS WHICH KEEP THE STRONGEST WINDS
ALONG HIGHWAY 61. THE AREA TO WATCH IS THE CENTRAL SANDHILLS WHERE
THE RAP AND NAM SHOW VERY STRONG 500M AGL WINDS APPROACHING 40 MPH
AT THE SFC MONDAY AFTERNOON.
NOTE THE FORECAST CONTINUES STRONG OR HIGH WINDS MONDAY NIGHT AND
TUESDAY WHICH WOULD NECESSITATE EXTENSIONS OF THE ON GOING HIGH
LIGHTS.
UPDATE ISSUED AT 837 PM CDT SUN APR 27 2014
A LOOK AT THE NEBRASKA DOR CAMS AND THE RAP MODEL SUGGEST WINTER
WEATHER ADVISORY CONDITIONS ACROSS SHERIDAN AND WESTERN CHERRY
COUNTIES. THE RAP INDICATES SEVERAL INCHES OF WET SNOW THIS
EVENING WHICH TAPERS OFF OR MIXES WITH RAIN AFTER MIDNIGHT. RADAR
INDICATES A DEFORMATION ZONE UNDERWAY ACROSS THIS AREA BUT MAINLY
ACROSS NRN SHERIDAN COUNTY. A WINTER ADVISORY IS IN PLACE FOR
THESE AREA AND IT OPERATES UNTIL 13Z.
THE FORECAST UPDATE FOLLOWS 50 PERCENT OF THE 23Z RAP AND 50
PERCENT OF THE PREVIOUS FORECAST. THE PTYPE USES THE RAP MODEL
WHICH SPREADS WET SNOW AS FAR SOUTH AS DEUEL COUNTY BUT LITTLE
ACCUMULATION IS EXPECTED THAT FAR SOUTH. IT LOOKS LIKE THE FAVORED
AREA FOR SNOW IS NORTHWEST NEBRASKA...NORTH OF THE NORTH PLATTE
VALLEY FOLLOWING THE H750 MB FRONT WHICH IS STRONGLY STACKED AND
MOVING VERY SLOWLY EAST TONIGHT. NOTE THE 23Z RAP PRODUCES OVER 1
INCH OF QPF ACROSS SHERIDAN COUNTY TONIGHT. THE FORECAST USES A
RATIO OF 6 TO 1 FOR 3 TO NEARLY 8 INCHES OF SNOW FAVORING PINE
RIDGE.
&&
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 407 PM CDT SUN APR 27 2014
FORECAST CONCERNS CONTINUE WITH THUNDERSTORM CHANCES TONIGHT...THEN
LEAD TO FORMATION OF DEFORMATION BAND AND SNOW POTENTIAL.
THE UPPER LOW WAS CENTERED OVER NORTHWEST KANSAS AS OF 20Z...WITH
THE SURFACE CIRCULATION ALMOST DIRECTLY OVER KCBK.
WITH THE SYSTEM BEING NEARLY VERTICALLY STACKED OVER NORTHWEST
KANSAS THIS AFTERNOON...THERE IS CONCERN THAT THE MODELS MAY BE
TRYING TO KICK THE SYSTEM EAST TOO QUICKLY THIS EVENING AND
OVERNIGHT. THIS WILL IMPACT THE AREAS THAT CONTINUE TO SEE
CONVECTION...WHERE THE PRECIPITATION FALLS...WHERE THE WINDS
STRENGTHEN...AND WHERE AND WHEN THE RAIN SWITCHES OVER TO SNOW.
THE LATEST RAP MODEL MOVES THE SURFACE CIRCULATION TO NEAR KMCK BY
00Z THIS EVENING THEN OVER KHSI AT 06Z AND THEN MOVES IT UP TO
AROUND KBVN BY 12Z. THIS SOLUTION IS QUITE SIMILAR TO THE NEW 18Z
NAM. THESE SOLUTIONS CONTINUE TO TRANSPORT MOISTURE AROUND THE
CIRCULATION AND ACROSS WESTERN AND CENTRAL NEBRASKA THROUGH THE
OVERNIGHT HOURS. STRONG FRONTOGENESIS SETS UP ON THE BACK SIDE OF
THE SYSTEM...CENTERED OVER THE PANHANDLE AND WESTERN SANDHILLS
OVERNIGHT. WITH GOOD MOISTURE IN THAT AREA AND SUBSTANTIAL LIFT DUE
TO THE LARGE SCALE FORCING AND FRONTOGENESIS...EXPECT A GOOD
DEFORMATION BAND TO BE ONGOING THROUGH MUCH OF THE NIGHT. SOME AREAS
COULD SEE UP TO AN INCH OF MOISTURE BY 12Z MONDAY MORNING. THE BIG
QUESTION WITH THE PRECIPITATION IS IF ENOUGH COLD AIR WILL MOVE IN
TO GET SOME AREAS TO GET A CHANGEOVER TO SNOW. THE NAM AND THE RAP
BOTH SHOW WET BULB PROFILES BELOW ZERO UNTIL ABOUT 300FT OR LESS
ABOVE THE GROUND IN AREAS OVER THE NORTHEAST PANHANDLE...ESPECIALLY
THE PINE RIDGE. IF THIS TURNS OUT...MAY SEE LOTS OF SNOW FALLING BUT
WILL BE MELTING WHEN HITTING THE SURFACE OR JUST PRIOR. BUT...EVEN
ONE DEGREE DIFFERENCE WILL BE ALL THAT IS NEEDED TO CHANGE OVER
COMPLETELY TO SNOW AND IF RATES BECOME STRONG ENOUGH...COULD GET
DECENT ACCUMULATIONS. AT THIS TIME...WITH THE MODELS ALL KEEPING THE
WET BULB TEMPERATURE ABOVE 0C...DID PUT A COMPLETE CHANGEOVER TO
SNOW IN THE NORTHWEST ZONES...BUT ONLY HAVE ACCUMULATIONS UP TO 2
INCHES ASSUMING THERE WILL BE SUBSTANTIAL MELTING AT THE SURFACE.
THE NEXT QUESTION WILL BE WHAT WILL REMAIN FOR CONVECTION AND
THUNDERSTORM CHANCES OVERNIGHT. KEPT AT LEAST A MENTION OF ISOLATED
THUNDER IN AREAS ALONG THE INVERTED TROUGH GOING NORTH OF THE
SURFACE LOW AS MOISTURE AND SOME WEAK INSTABILITY WILL CONTINUE TO
CIRCULATE AROUND THE SYSTEM.
MOVING ON TO WINDS...A VERY TIGHT PRESSURE GRADIENT WILL BE SEEN ON
THE BACKSIDE OF THE SYSTEM...WHICH SHOULD CAUSE WINDS TO STRENGTHEN
ACROSS THE AREA AS THE LOW MOVES EAST TONIGHT. THE ONGOING WIND
ADVISORY FOR AREAS MAINLY WEST OF HIGHWAY 83 FOR THE OVERNIGHT
PERIODS CONTINUES TO LOOK GOOD AS SUSTAINED WINDS AROUND 30MPH STILL
LOOK LIKELY.
WITH THE POTENTIAL FOR MODERATE TO HEAVY SNOW AND STRONG WINDS OVER
THE NORTHEAST PART OF THE FORECAST AREA TONIGHT...DID CONSIDER A
NEED FOR A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO MONDAY
MORNING. AT THIS TIME...DUE TO THE UNCERTAINTY ON THE SWITCHOVER TO
SNOW...OPTED TO NOT ISSUE AT THIS TIME AND WILL MONITOR CLOSELY IF
HEADLINES ARE NEEDED.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 407 PM CDT SUN APR 27 2014
TOMORROW THROUGH WEDNESDAY...MAIN FORECAST CHALLENGES ARE WINDS AND
PRECIPITATION CHANCES IN ASSOCIATION WITH A SLOW MOVING UPPER LEVEL
LOW...WHICH WILL MIGRATE FROM EASTERN NEBRASKA INTO THE UPPER
MISSISSIPPI VALLEY OVER THE NEXT 24 TO 84 HOURS. IN ADDITION TO
PRECIPITATION CHANCES...THE THREAT FOR SNOW...PARTICULARLY DURING
THE NIGHTTIME HOURS...WILL BE A CONCERN ACROSS NORTHERN NEBRASKA
MONDAY NIGHT AND TUESDAY NIGHT.
FOR MONDAY...PRECIPITATION CHANCES AND WINDS WILL BE THE MAIN
FORECASTING CONCERN. ON MONDAY...THE MAIN UPPER LEVEL LOW WILL
MEANDER ACROSS CENTRAL NEBRASKA...DRIFTING INTO EASTERN NEBRASKA BY
LATE AFTERNOON. STRONG WINDS WILL DEVELOP ACROSS CENTRAL AND WESTERN
PORTIONS OF THE FORECAST AREA MONDAY AS H85 WINDS REACH 40 TO 50 KTS
IN THE SOUTHWEST AND SOUTHEASTERN PANHANDLE MONDAY AFTERNOON. WIND
SPEEDS DECREASE FAIRLY QUICKLY EAST OF THE HIGHWAY 83 CORRIDOR AND
DO NOT REALLY BEGIN TO KICK IN UNTIL MONDAY EVENING. TO AVOID
CONFUSION...DECIDED TO HOIST A HIGH WIND WATCH FOR LOCATIONS ROUGHLY
WEST OF A LINE FROM HAYES CENTER...TO ARTHUR...TO GARDEN COUNTY. IN
THESE AREAS...A WIND ADVISORY WILL LIKELY BE NEEDED TOMORROW...BUT
AT THIS TIME...I DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A HIGH WIND
WARNING AND WILL ISSUE A WATCH AND LET THE MIDNIGHT CREW MAKE THE
CALL. FURTHER EAST...TO THE HIGHWAY 83 CORRIDOR...NORTHERLY WINDS
WILL INCREASE BY MIDDAY AND ARE EXPECTED TO REACH ADVISORY
CRITERIA...FROM LINCOLN COUNTY NWD TO WESTERN CHERRY COUNTY AND WILL
HOIST A WIND ADVISORY FOR THESE AREAS. IN ADDITION TO WIND...THERE
IS STILL A SMALL THREAT FOR ACCUMULATING SNOWS MONDAY MORNING IN THE
FAR NORTHWESTERN FORECAST AREA IN THE VICINITY OF THE PINE RIDGE.
LIKE YESTERDAY...THE NAM HAS THE COLDEST BOUNDARY LAYER OF THE THREE
MID RANGE MODELS. GIVEN THE LACK OF COLD UPSTREAM AIR ACROSS NERN
WYOMING AND WESTERN SOUTH DAKOTA ATTM...AM INCLINED TO TREND TEMPS
TOWARD THE WARMER GFS AND ECMWF SOLNS. WITH THIS IN MIND...HAVE
WORDED THE FORECAST WITH A RAIN SNOW MIX THROUGH MID MORNING WITH
LITTLE OR NO SNOW ACCUMS EXPECTED. WILL CONTINUE TO MONITOR THIS
AREA CLOSELY. AS THE DAY PROGRESSES...WIDESPREAD RAIN WILL
CONTINUE...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE
FORECAST AREA...WHERE A STRONG MID LEVEL DEFORMATION ZONE WILL SET
UP AND PERSISTENT ISENTROPIC LIFT CONTINUES THROUGH THE AFTERNOON
HOURS.
ON MONDAY NIGHT...WINDS WILL INCREASE IN THE EAST AND SUBSIDE SOME
IN THE WEST AS THE UPPER LEVEL LOW MEANDERS INTO SWRN IOWA AND
NORTHWEST MISSOURI. WINDS WILL REMAIN ON THE GUSTY SIDE INTO THE
OVERNIGHT HOURS...WHICH MAY NECESSITATE ISSUANCE OF A WIND ADVISORY
MONDAY NIGHT. BASED ON THE LATEST MAV GUIDANCE AND BUFKIT
DATA...ALMOST THE ENTIRE FORECAST AREA MAY NEED A WIND ADVISORY FOR
MONDAY NIGHT. GIVEN THE ONGOING WIND HEADLINES...WILL HOLD OFF ON
ISSUANCE ATTM TO AVOID CONFUSION WITH OUR CURRENT HEADLINES. DECENT
ISENTROPIC LIFT CONTINUES INTO TUESDAY MORNING...ESPECIALLY OVER
CENTRAL AND NORTHERN NEBRASKA AND WILL CONTINUE LIKELY TO
CATEGORICAL POPS OVERNIGHT.
TUESDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL MEANDER EAST ON
TUESDAY INTO WEDNESDAY...ENDING UP OVER THE WESTERN GREAT LAKES BY
THURSDAY MORNING. DURING THE PERIOD...THE THREAT FOR LIGHT RAIN WILL
CONTINUE TUESDAY WITH GUSTY WINDS EXPECTED AS WELL. H85 WINDS WILL
DECREASE TO 35 TO 45 KTS ON TUESDAY...SO ANOTHER MAY BE NEEDED FOR
TUESDAY ACROSS MOST OF THE FORECAST AREA. TEMPS WILL REMAIN COOL
HOWEVER WITH MOSTLY CLOUDY SKIES AND WITH H85 TEMPS RANGING FROM -2C
IN THE NORTHEAST...TO 3 C IN THE SOUTHWEST...HIGHS TUESDAY WILL
STRUGGLE TO GET OUT OF THE UPPER 30S TO 40S. ON WEDNESDAY...H85
TEMPS WILL WARM TO 1C IN THE NORTHEAST...TO 5C IN THE SOUTHWEST.
AFTERNOON HIGHS WILL REBOUND SLIGHTLY TO THE 40S TO LOWER 50S. WINDS
WILL BE SOMEWHAT LIGHTER...THOUGH WINDY WITH WIND SPEEDS OF 20 TO 30
MPH...WITH SOME HIGHER GUSTS TO 40 MPH. AT THIS TIME...AM NOT
ANTICIPATING ANY WIND HEADLINES ATTM.
WEDNESDAY NIGHT AND BEYOND...THE UPPER LEVEL LOW WILL BE ABSORBED
BY THE NORTHERN STREAM AND LIFTED EAST TOWARD THE END OF THE WEEK.
HOWEVER...LOW PRESSURE ALOFT WILL REMAIN ANCHORED OVER SOUTH CENTRAL
CANADA...AND WILL FORCE COLD AIR INTO THE NORTHERN PLAINS LATE IN
THE WEEK INTO THE WEEKEND. MAINLY DRY CONDITIONS ARE EXPECTED WITH
THIS FLOW REGIME. HIGHS WILL BE MORE MARCH LIKE WITH READINGS IN THE
50S EXPECTED FRIDAY...SATURDAY AND SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1141 PM CDT SUN APR 27 2014
WIDESPREAD MVFR/IFR IN RAIN AND SNOW IS EXPECTED TONIGHT THROUGH
MONDAY EVENING AS A SLOW MOVING STORM TRACKS THROUGH THE CENTRAL
PLAINS. WINDS 32035G45KT SHOULD REDEVELOP MONDAY MORNING AND SPREAD
FROM WEST TO EAST THROUGH MONDAY AFTN. WINDS SUBSIDE AROUND SUNSET.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 7 AM CDT /6 AM MDT/ TO 7 PM CDT /6 PM
MDT/ MONDAY FOR NEZ022-035-056>058-069-070.
WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NEZ022-035-
056>058-069-070.
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ004-
023>025-036-037-059-071-094.
WINTER WEATHER ADVISORY UNTIL 7 AM MDT MONDAY FOR NEZ004-094.
WIND ADVISORY FROM 7 AM TO 7 PM CDT MONDAY FOR NEZ005-006-008-
009-026-027-038.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...BROOKS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
335 AM CDT MON APR 28 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 335 AM CDT MON APR 28 2014
THE MAIN FORECAST FOCUS WILL BE CONTINUED PRECIP CHANCES TODAY AND
TONIGHT.
WATER VAPOR IMAGERY THIS MORNING SHOWS THE WELL-DEFINED MID-LEVEL
CYCLONE OVER NEBRASKA...WITH MOISTURE ROTATING NORTHWARD ON THE
EASTERN FLANK OF THE SYSTEM...AND THE STRONGER CONVECTION WELL TO
THE SOUTHEAST. THE CURRENT BAND OF RAIN CONTINUES TO LIFT ACROSS
THE NORTHERN FORECAST AREA...WITH A BREAK TO THE SOUTH. BASED ON
SFC OBS...SOME MIXED PRECIP MAY BE OCCURRING FROM NC ND INTO THE
DVL BASIN.
MORE RAIN CONTINUES TO DEVELOP ACROSS S MN/IOWA WHICH WILL LIFT TO
THE NORTH AND WEST TODAY BRINGING WIDESPREAD RAINFALL TO THE
REGION...WITH ADDITIONAL AMOUNTS OVER AN INCH POSSIBLE. THE AREA
MOST LIKELY TO MISS OUT ON THE MAJORITY OF THE PRECIP WILL BE UP
TOWARDS THE LAKE OF THE WOODS AREA...WITH THE MODEL CONSENSUS
SUGGESTING THE HEAVIEST PRECIP FROM THE NORTHERN VALLEY SOUTHEAST
INTO CENTRAL MN. VERY DRY AIR IS STILL IN PLACE UP TOWARDS FLAG
ISLAND...SO THERE COULD BE A SHARP CUT-OFF IN PRECIP UP IN THIS
AREA...WITH EVEN SOME DRYING FROM THE NORTHEAST LATE IN THE DAY. SO
POP TRENDS WILL NEED TO BE FINE-TUNED IN LATER UPDATES. WINDS WILL BE
BRISK FROM THE EAST...WITH TEMPS NOT MOVING MUCH TODAY WITH THE
WIDESPREAD PRECIP AND CLOUDS.
BY TONIGHT...AN UPPER JET/SHORTWAVE WILL NOSE INTO THE OHIO
VALLEY...SHUNTING THE BETTER MOISTURE EASTWARD. AT THE SAME
TIME...DRY AIR WILL WORK IN FROM THE NORTHEAST. PRECIP SHOULD END
TO THE NORTH WITH SOME LIGHT PRECIP REMAINING FARTHER SOUTH. AS
TEMPS COOL...PRECIP COULD MIX WITH OR CHANGE TO SNOW...WITH
PERHAPS SOME LIGHT ACCUMULATIONS IN AREAS.
TUESDAY LOOKS TO BE DRY OVER MUCH OF THE AREA WITH NORTHERLY
FLOW. THE POSSIBLE EXCEPTION COULD BE ALONG THE SD BORDER INTO WC
MN CLOSER TO THE LOW. WITH SOME SUN...TEMPS COULD CREEP UP TOWARDS
50...ALTHOUGH WINDS WILL REMAIN ON THE STRONG SIDE WITH COLD ADVECTION.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON APR 28 2014
AS THE STACKED LOW PRESSURE SYSTEM SLOWLY PUSHES TOWARDS THE GREAT
LAKES TUES NIGHT/WEDNESDAY AND SHORTWAVE ENERGY ROTATES AROUND THE
CIRCULATION...PRECIP CHANCES WILL INCREASE FROM THE WEST. BY THIS
TIME...THE BETTER LOW-LEVEL MOISTURE TRANSPORT WILL BE WELL EAST...SO
TOTALS WOULD BE LIGHT. THE GFS IS A BIT WETTER AND BRINGS THE PRECIP
FARTHER WEST...WHILE THE ECMWF KEEPS MOST OF THE PRECIP IN MN. IT
MAY BE JUST COLD ENOUGH FOR SOME SNOW TUES NIGHT INTO
WEDNESDAY...BUT ACCUMULATIONS WOULD BE LIGHT. WITH THE UPPER PATTERN
CHANGING LITTLE...WEDNESDAY WILL BE ANOTHER COOL DAY WITH HIGHS IN
THE 40S AND A TIGHT SFC GRADIENT KEEPING WINDS QUITE BREEZY FROM THE
NORTH.
FOR THURSDAY THROUGH SUNDAY...EXPECT THE CONTINUATION OF TEMPS BELOW
NORMAL ALONG WITH PERIODIC CHANCES FOR RAIN SHOWERS. THERE COULD
EVEN BE SOME SNOW MIXING IN AT TIMES OVERNIGHT...BUT OVERALL ANY
PRECIP SHOULD REMAIN LIQUID. ANY PRECIP SHOULD ALSO BE LIGHT...WITH
DEEPER MOISTURE WELL TO OUR SOUTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1140 PM CDT SUN APR 27 2014
THE FIRST BATCH OF RAIN IS MOVING NORTHWARD ACROSS THE REGION.
EXPECT A BRIEF BREAK IN ACTIVITY SOMETIME DURING THE OVERNIGHT
AND/OR EARLY MORNING HOURS. A SECOND BATCH OF RAIN WILL THEN EXPAND
INTO A MAJORITY OF THE REGION SOMETIME AFTER SUNRISE MONDAY MORNING.
ATTEMPTED TO ADD THIS DETAIL TO THE FORECAST. CIGS WILL CONTINUE TO
BE TRICKY AS MOST GUIDANCE IS TOO LOW (BECAUSE OF THE LOW LEVEL
EASTERLY FLOW FROM A DRY AIRMASS). RAP GUIDANCE APPEARS TO HAVE THE
BEST IDEA THAT CURRENT CONDITIONS WILL PREVAIL THROUGH THE
PERIOD...WITH POSSIBLE LOWER CIGS AS PRECIP RATES INCREASE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...MAKOWSKI
LONG TERM...DK/MAKOWSKI
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1140 PM CDT SUN APR 27 2014
.UPDATE...
ISSUED AT 933 PM CDT SUN APR 27 2014
FORECAST IS UNFOLDING AS EXPECTED. THE ONLY UPDATE WILL BE TO
INDICATE A BRIEF BREAK IN ACTIVITY WITH 30% POPS. THE REGION WILL
REMAIN WITHIN THE TROWAL (WHICH WILL GRADUALLY LIFT NORTH
OVERNIGHT). WE KNOW THAT RAIN WILL OCCUR WITHIN THIS FEATURE...AND
ALL AREAS WILL RECEIVE RAINFALL. THE HARD PART IS ATTEMPTING TO
FORECAST EXACTLY WHEN AND WHERE WAVES ROTATING AROUND THE MAIN
UPPER LOW WILL INFLUENCE AREAS WITHIN THE TROWAL. THE HRRR DID A
GOOD JOB LAST NIGHT...AND WILL FOLLOW AS GUIDANCE FOR TONIGHT. THE
RAIN ACROSS THE SOUTHERN FA WILL LIFT NORTH OVERNIGHT...AND
ANTICIPATE A BREAK IN ACTIVITY ONCE THIS ACTIVITY MOVES TO THE
NORTH. ADJUSTED POPS FOR THIS THINKING. THE NEXT WAVE...OR AREA OF
FORCING...IS ASSOCIATED WITH THE ACTIVITY JUST ENTERING SOUTHERN
IOWA. THIS ACTIVITY SHOULD EXPAND TO THE NORTHWEST
OVERNIGHT...ENTERING WEST CENTRAL MINNESOTA 10Z-12Z...THEN
EXPANDING INTO MUCH OF THE FA AFTER 12Z MONDAY MORNING (CONTINUING
THROUGH MUCH OF THE DAY...STARTING TO DRY FROM THE NORTHEAST BY
LATE AFTERNOON).
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 343 PM CDT SUN APR 27 2014
CHALLENGES INCLUDE WINDS LATE THIS AFTERNOON AND EVENING AND THEN
PRECIP CHANCES/TYPE/AMOUNTS THROUGH THE REMAINDER OF THE FORECAST
PERIOD. WILL USE RAP/HRRR FOR THE NEXT 6 TO 12 HOURS AND THEN
TRANSITION TO A GLOBAL MODEL BLEND THEREAFTER AS GFS/NAM/ECMWF/
GEM ARE IN RELATIVELY GOOD AGREEMENT.
IN THE NEAR TERM...WILL LET WIND ADVISORY CONTINUE UNTIL 7 PM CDT.
MOST AREAS WON/T HIT CRITERIA...BUT FINALLY STARTING TO SEE SOME
MORE WIDESPREAD OBSERVATIONS AT OR ABOVE 30 MPH.
20 UTC WATER VAPOR LOOP SHOWS PRIMARY VORTICITY MAXIMA ACROSS
WESTERN KS WITH A STRONG SHORT-WAVE ROTATING OUT OF ITS BASE.
STRONG WARM AIR AND MOISTURE ADVECTION (PWATS TO ONE INCH) ALONG
THE 850 HPA SFC THIS EVENING AND OVERNIGHT...COMBINED WITH
DIVERGENT FLOW ALOFT WILL RESULT IN INCREASING SHOWERS MOVING FROM
SOUTH TO NORTH. ADDED THUNDER BACK INTO THE FORECAST ACROSS THE
SOUTH THIS EVENING WITH ISOLATED LIGHTNING STRIKES ALONG THE ND/SD
BORDER. INSTABILITY IS MINIMAL...BUT SPC MESOANALYSIS SHOWS A
COUPLE HUNDRED JOULES OF MOST UNSTABLE CAPE. THERMAL PROFILES WARM
ENOUGH TONIGHT FOR ALL RAIN...BUT COULD SEE A FEW FLAKES IN THE
MIX.
WILL LIFT CATEGORICAL POPS TO THE NORTH TONIGHT AND MONDAY. MONDAY
WILL BE CLOUDY AND COOL WITH PERIODS OF LIGHT TO MODERATE RAIN
SHOWERS. TEMPERATURES WILL RISE INTO THE UPPER 30S TO MID 40S WITH
PERSISTENT BREEZY EASTERLY WIND. 850 HPA TEMPERATURES BEGIN TO
FALL BELOW FREEZING MONDAY NIGHT WITH MOST OF THE COLUMN BELOW 0 C
BY TUESDAY MORNING EXCEPT THE NEAR SFC LAYER. PTYPE WILL DEPEND
HEAVILY ON SFC TEMPERATURES...BUT WITH FORECAST VALUES PLUS OR
MINUS A FEW DEGREES AROUND FREEZING MONDAY NIGHT...WILL KEEP A
RAIN/SNOW MIX IN THE WEATHER GRIDS. NOT REALLY EXPECTING MUCH
ACCUMULATION AS MOST SNOW THAT DOES FALL SHOULD MELT ON CONTACT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 343 PM CDT SUN APR 27 2014
STRONG DRYING WILL WORK ITS WAY SOUTH ON TUESDAY AS THE LOW
PRESSURE SYSTEM SCOOTS ACROSS IA INTO WI. SHOULD SEE A BREAK IN
PRECIP...ESPECIALLY FOR THE CENTRAL AND NORTHERN FORECAST AREA.
COULD EVEN SEE SOME PEAKS OF SUN. PTYPE SHOULD BE MOSTLY RAIN WITH
HIGHS RISING INTO THE MID TO UPPER 40S. WINDS WILL REMAIN BREEZY
AND SHIFT TO THE NORTH.
WRAP AROUND PRECIP WILL RETURN WEDNESDAY AS THE LOW WOBBLES ACROSS
WI WITH A GREATER CHANCE FOR A RAIN/SNOW MIX OR EVEN ALL SNOW AT
TIMES GIVEN A SATURATED SUB-FREEZING COLUMN. PTYPE WILL AGAIN
DEPEND ON SFC TEMPERATURES WITH MINIMAL ACCUMULATIONS. WHEN ALL IS
SAID AND DONE...LIQUID ACCUMULATIONS OVER THE 2 TO 3 DAY PERIOD
WILL BE 1 TO 2 INCHES WITH LOCALLY HIGHER AMOUNTS IN HEAVIER
SHOWERS OR THUNDERSTORMS. ANY SNOW ACCUMULATION SHOULD BE CONFINED
MAINLY TO THE HIGHER TERRAIN ON EITHER SIDE OF THE VALLEY BUT ONLY
AN INCH OR LESS.
UPPER LOW AND SURFACE LOW WILL REMAIN OVER THE GREAT LAKES WEDNESDAY
NIGHT INTO THURSDAY WITH NORTH WINDS AND SPOTTY RAIN SHOWERS ALONG
WITH CONTINUED WELL BELOW NORMAL TEMPERATURES. 12Z ECMWF/GFS ALL
INDICATE 500 MB TROUGH TO REMAIN IN PLACE WITH NEXT SHORT WAVE
DROPPING SOUTH INTO THE NRN PLAINS FRIDAY NIGHT-SATURDAY WITH
ANOTHER CHANCE OF SHOWERS. NO HEAVY RAINFALL THIS PERIOD BUT AT
LEAST A CHANCE FOR SHOWERS EACH DAY AND TEMPS REMAIN BELOW AVERAGE
INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1140 PM CDT SUN APR 27 2014
THE FIRST BATCH OF RAIN IS MOVING NORTHWARD ACROSS THE REGION.
EXPECT A BRIEF BREAK IN ACTIVITY SOMETIME DURING THE OVERNIGHT
AND/OR EARLY MORNING HOURS. A SECOND BATCH OF RAIN WILL THEN EXPAND
INTO A MAJORITY OF THE REGION SOMETIME AFTER SUNRISE MONDAY MORNING.
ATTEMPTED TO ADD THIS DETAIL TO THE FORECAST. CIGS WILL CONTINUE TO
BE TRICKY AS MOST GUIDANCE IS TOO LOW (BECAUSE OF THE LOW LEVEL
EASTERLY FLOW FROM A DRY AIRMASS). RAP GUIDANCE APPEARS TO HAVE THE
BEST IDEA THAT CURRENT CONDITIONS WILL PREVAIL THROUGH THE
PERIOD...WITH POSSIBLE LOWER CIGS AS PRECIP RATES INCREASE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...ROGERS
LONG TERM...ROGERS/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
214 AM EDT MON APR 28 2014
.SYNOPSIS...
A WET AND STORMY PATTERN WILL SET UP ACROSS THE AREA MONDAY THROUGH
WEDNESDAY...FOLLOWED BY COOL AND DRIER HIGH PRESSURE BY THE END OF
THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 2 AM...SCATTERED SHOWERS ACROSS NC HAVE BEEN ON A GENERAL
DECREASING TREND OVER THE PAST COUPLE OF HOURS...SO HAVE GENERALLY
FEATURED GRADUALLY WANING POPS AS THE CURRENT ACTIVITY LIFTS ACROSS
THE FOOTHILLS AND PIEDMONT. HOWEVER...ADDITIONAL WARM SECTOR SHOWERS
AND EVEN A TS OR TWO HAVE BEEN INITIATING OVER THE TN VALLEY IN
REGION OF GENERAL WAA AND B.L. CONVERGENCE...SO SMALL POPS WILL BE
RETAINED ACROSS THE FAR WESTERN MTNS THROUGH THE OVERNIGHT.
DEWPOINTS IN THE 50S AND WIDESPREAD CIRRUS BLOW-OFF FROM TENN/MISS
VALLEY CONVECTIVE COMPLEX WILL HOLD MIN TEMPS ABOUT 10-15 DEGREES
ABOVE CLIMO THIS MORNING.
AS OF 1010 PM EDT SUNDAY...BLENDED POPS ARE WORKING WELL AS
SCATTERED LIGHT SHOWERS HAVE DEVELOPED OVER THE WESTERN ZONES...AND
A FEW STRONGER STORMS HAVE DEVELOPED NOT TOO FAR UPSTREAM OF THE
FORECAST AREA. POPS AND SKY COVER LOOK GOOD.
AT 735 PM EDT SUNDAY...BLENDED A POP DERIVED FROM LOCAL CONVECTIVE
ALLOWING MODELS AND THE OFFICIAL FORECAST TO GO WITH A SMALL AREA OF
HIGH CHANCE AND LIKELY POPS FROM THE UPSTATE INTO THE SRN AND
CENTRAL NC MTNS. THE 18 UTC NAM HAD A LITTLE BETTER ELEVATED CAPE
ACROSS THIS AREA AND THE HRRR AND WRF-ARW ARE INCREASES CONVECTIVE
COVERAGE OVER THIS AREA LATER TONIGHT. OTHERWISE...INCREASED SKY
COVER AND MADE SOME MINOR TWEAKS TO THE REST OF THE GRIDS.
AT 430 PM EDT SUNDAY...ADJUSTED SKY GRIDS TO ACCOUNT FOR ENCROACHING
HIGH CLOUDS AS WELL AS A CU DECK THAT IS DEVELOPING ACROSS NE
GA...THE SW NC MTNS AND THE WRN UPSTATE. SOME OF THE MESOSCALE
MODELS BRING ELEVATED CONVECTION ACROSS THE FORECAST AREA OVERNIGHT
AS THE LEADING EDGE OF THE ELEVATED MIXED LAYER WORKS IN FROM THE
WEST. I DON/T SEE MUCH MUCAPE ON THE 18 UTC NAM...SO THINK MOST OF
THE ACTIVITY WILL BE WEAK. I WON/T ADJUST THE OVERNIGHT GRIDS JUST
YET..BUT I NEED TO RAMP UP POPS WITH SUBSEQUENT UPDATES.
AT 200 PM EDT SUNDAY...A NEGATIVELY TILTED UPPER TROUGH WILL SLOWLY
PROGRESS ACROSS THE SOUTHERN APPALACHIANS AND GREAT LAKES TONIGHT...
WHILE A CLOSED UPPER LOW MOVES NE ACROSS THE GREAT PLAINS. THE RIDGE
AXIS MOVES EAST OF THE MOUNTAINS ON MONDAY...WHILE THE UPPER LOW
DRIFTS BACK SOUTH OVER THE PLAINS.
ISENTROPIC UPGLIDE WILL SPREAD ACROSS THE UPPER SAVANNAH RIVER
VALLEY AND SOUTHERN APPALACHIANS LATE THIS AFTERNOON AND THIS
EVENING. INSTABILITY SHOULD BECOME SUFFICIENT FOR CONVECTION TO FORM
BEFORE EVENING...HOWEVER NEITHER SHEAR NOR INSTABILITY APPEAR
IMPRESSIVE. A BACK DOOR COLD FRONT WILL SETTLE SOUTH ACROSS WESTERN
NC TONIGHT...REACHING THE SC BORDER EAST OF THE MOUNTAINS BY
DAYBREAK.
THE BOUNDARY WILL BECOME A FOCUS FOR CONVECTIVE ACTIVITY ON
MONDAY...WHEN BETTER SHEAR AND INSTABILITY WILL BE PRESENT. SPC HAS
OUR ENTIRE AREA IN A SLIGHT RISK FOR SEVERE WEATHER ON DAY
TWO...MENTIONING AN ENVIRONMENT FAVORABLE FOR SUPERCELLS. THE AREA
NORTH OF INTERSTATE 40 MAY REMAIN UNFAVORABLE FOR CONVECTION DURING
THE DAYLIGHT HOURS ON MONDAY...AS COOL NE FLOW PREVAILS BEHIND THE
FRONT...AND A CAP REMAINS AT AROUND 875 MB. WITH THE BEST GULF
INFLOW STILL WELL TO THE WEST...EXCESSIVE RAINFALL IS NOT
EXPECTED...HOWEVER INDIVIDUAL STORMS MAY PUT DOWN LOCALLY HEAVY
RAINFALL.
MINIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL UNDER INCREASING
CLOUDS COVER AND THE UPPER RIDGE. HIGH TEMPERATURES ON MONDAY WILL
RUN SLIGHTLY ABOVE NORMAL...AS CLOUD COVERAGE OFFSETS THE INFLUENCE
OF THE UPPER RIDGE.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 235 PM SUNDAY...NOTHING IN THE NEW GUIDANCE TO CHANGE EARLIER
THINKING THAT WE ARE ON A COLLISION COURSE WITH A VERY WET AND VERY
STORMY PATTERN DURING THE LATE MONDAY TO WEDNESDAY TIME FRAME.
IMPORTANT DETAILS SUCH AS THE TIMING OF ENHANCED SEVERE THUNDERSTORM
THREATS...AND STORM TOTAL RAINFALL...STILL REMAIN IN DOUBT.
ONE INTERESTING TREND OR POINT OF CONCERN IS BROUGHT TO LIGHT IN THE
LATEST NAM MONDAY NIGHT AND EARLY TUESDAY MORNING. A WEDGE BOUNDARY
OF SORTS IS INDICATED EVEN FARTHER SOUTH THAN PREVIOUS RUNS...DOWN
CLOSER TO THE SC/NC BORDER. THE AIR MASS TO THE SOUTH OF THE
BOUNDARY MIGHT BE FAIRLY RICH WITH BUOYANCY. THE SREF HAS A VERY
HIGH PROBABILITY OF CAPE GREATER THAN 1000 J/KG LATE IN THE
DAY...AND EVEN THE GENERALLY MORE CONSERVATIVE GFS HAS CAPE IN THE
1000 - 1500 J/KG RANGE. SHEAR AND SRH WILL INCREASE STEADILY THROUGH
THE EVENING HOURS IN THE PRESENCE OF ADEQUATE BUOYANCY...THUS OUR
CHANCES FOR ORGANIZED SEVERE THUNDERSTORMS WILL ALSO INCREASE. AGREE
WITH THE EXPANSION OF THE DAY2 SLIGHT RISK FURTHER EAST IN THE NEW
OUTLOOK. IF THE WEST TO EAST ORIENTED BOUNDARY REMAINS IN THE
AREA...THIS COULD PROVIDE THE FOCUS FOR SEVERE STORMS AND TORNADIC
ACTIVITY SOMEWHERE IN THE CAROLINAS WELL INTO THE OVERNIGHT HOURS.
THERE IS ALSO THE CONCERN THAT SUPERCELLULAR CONVECTION MOVING IN
FROM GEORGIA DURING THE EVENING WILL GET A SHOT OF INCREASED SHEAR
AS IT INTERACTS WITH A BOUNDARY. AT THE SAME TIME...THE FRONTAL ZONE
OF HEAVIER RAIN WILL MOVE INTO THE MOUNTAINS.
CONFIDENCE IN THE TIMING OF ANY MESOSCALE CONVECTIVE SYSTEMS GOES
DOWN AFTER LATE MONDAY NIGHT...BUT WE WILL RETAIN A FAVORABLE
COMBINATION OF SHEAR AND INSTABILITY TO KEEP A THREAT OF SEVERE
STORMS THROUGH TUESDAY ACROSS MOST OF THE FCST AREA...WITH PERHAPS
THE EXCEPTION OF THE WRN NC MTNS...AND INTO WEDNESDAY EAST OF THE
MOUNTAINS. ONE MIGHT EXPECT A BIT OF A LULL OR RECHARGE PERIOD
TUESDAY MORNING...BEFORE MORE ORGANIZED SEVERE WEATHER AFFECTS THE
REGION TUESDAY AFTERNOON AND EVENING WITH DIURNAL ENHANCEMENT. CAPE
PROFILES SUGGEST THAT WE MIGHT HAVE A BIT LESS OF A CHANCE OF
SUPERCELLS AND THE LIKE...BECAUSE OF CONVECTIVE DEBRIS/
OVERTURNING...BUT STILL ENOUGH OF A TORNADO THREAT FOR CONTINUED
CONCERN BECAUSE OF THE SHEAR. ADDITIONAL DETAILS WILL HOPEFULLY COME
MORE INTO FOCUS WITH SUBSEQUENT FCST PACKAGES.
AT ANY RATE...PRECIP CHANCES RAMP UP STEADILY FROM THE WEST INTO THE
LIKELY TO CATEGORICAL RANGE MONDAY NIGHT AND INTO TUESDAY AND
TUESDAY NIGHT. THE LATEST QPF GUIDANCE FROM WPC IS VERY TROUBLESOME.
ON THE ONE HAND...ANOMALY GUIDANCE DOES NOT SHOW ANYTHING OVERLY
ALARMING WITH REGARD TO PRECIPITABLE WATER...BUT ON THE OTHER HAND
THE SLOW MOVING NATURE OF THE COLD FRONT WILL PERMIT WAVES OF
MODERATE TO HEAVY RAIN STARTING EARLY TUESDAY MORNING...AND
CONTINUING INTO WEDNESDAY. UNLESS THERE IS SOME CHANGE IN
THINKING... THE NEED FOR A FLOOD WATCH IS NEARLY A FOREGONE
CONCLUSION...BUT THE MAIN THREAT OF FLOODING DOES NOT RAMP UP UNTIL
DURING THE DAY ON TUESDAY BASED ON THE QPF BREAKDOWN. SINCE THIS IS
THE 4TH FCST PERIOD AND WE HAVE SOME TIME TO GAIN MORE CONFIDENCE...
WILL HOLD OFF ON A FLOOD WATCH FOR ONE MORE FCST CYCLE.
MODEL GUIDANCE SHOWS THE FRONT CROSSING THE FCST AREA WEDNESDAY
EVENING AND THAT SHOULD BRING AN END TO MOST OF THE PRECIP...WITH
SOME LINGERING SHOWERS POSSIBLE ON THE TN BORDER OVER THE NRN MTNS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1 PM SUNDAY...EXPANSIVE UPPER TROUGH WILL REMAIN OVER THE ERN
CONUS THROUGH THE MEDIUM RANGE...WITH THE FLOW EVENTUALLY FLATTENING
BY THE END OF NEXT WEEKEND. FAIRLY UNSETTLED CONDITIONS WILL CONTINUE
ACRS THE SOUTHEAST REGION UNTIL THAT TIME. FRONTAL BOUNDARY LAYS OUT
JUST OFFSHORE FRIDAY.
GFS/EC/GEM AGREE ON A SHORTWAVE ROUNDING THE LARGER SCALE TROUGH AND
BRINGING A WAVE OUT OF THE GULF OF MEXICO ALONG THE FRONT. THEY
DISAGREE HOWEVER ON THE TIMING OF THIS EVENT. 12Z GFS/GEM DEVELOP
ONLY A WEAK WAVE FRIDAY...AND HAVE A LOW IMPACT ON OUR CWFA WITH VERY
LITTLE QPF. ORIENTATION OF THE FRONT ON THE 00Z EC LEADS IT TO
DEVELOP A STRONGER WAVE AND BRING ANOTHER ROUND OF PRECIP TO THE
PIEDMONT FRIDAY NIGHT AND SATURDAY. GFS CONCURRENTLY DEVELOPS SHOWERS
IN THE MTNS AS IT BRINGS THE WAVE ACRS EARLY SATURDAY...WITH
ADDITIONAL NW FLOW PRECIP CONTINUING INTO EARLY SUNDAY. THIS IS A
PLAUSIBLE SCENARIO THOUGH IT IS THE ONLY MODEL SHOWING IT. QPF FROM
THIS ACTIVITY IS NOTABLE BUT NOT HIGH ENOUGH FOR CONCERN...SO IT WILL
BE MINIMALLY REFLECTED IN THE FCST. IN FACT...NCEP/CMC ENSEMBLES GIVE
LITTLE SUPPORT TO A WETTER EC-LIKE SOLUTION SO POPS WILL BE KEPT ON
THE LOW SIDE FOR THE POTENTIAL FRONTAL WAVE PRECIP...ALONG WITH QPF.
AFTER ABV NORMAL TEMPS THU...TEMPS RETURN TO AROUND NORMAL FRI INTO
SAT WITH CLOUD COVER. LOWS SUNDAY MRNG SHOULD BE A COUPLE CATEGORIES
BELOW NORMAL BUT TEMPS REBOUND SUNDAY UNDER CLEARER SKIES.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AT KCLT...THE FIRST 12 HOURS OR SO OF THE FORECAST IS RELATIVELY
STRAIGHT FORWARD...WITH PRIMARILY HIGH/MID-LEVEL CLOUDS EXPECTED
ALONG WITH SOUTH WINDS. HOWEVER...UNCERTAINTY INCREASES
SUBSTANTIALLY FROM AFTERNOON ONWARD. A WEAK BACK DOOR FRONT WILL
DROP SLOWLY SOUTH ACROSS THE PIEDMONT LATER THIS MORNING (WITH WINDS
TURNING TO THE E/NE NORTH OF THE FRONT) BEFORE STALLING AND
EVENTUALLY LIFTING NORTH...BUT IT IS VERY UNCERTAIN AS TO WHETHER
THIS WILL MAKE IT AS FAR SOUTH AS KCLT. CERTAINLY A CONSENSUS OF
FORECAST GUIDANCE WOULD KEEP THE FRONT NORTH OF THE TERMINAL...AND
WE HAVE SIDED WITH THIS CONSENSUS. WHEREVER THE FRONT SETS UP...IT
IS EXPECTED TO PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT THIS
AFTERNOON...AS THE ATMOSPHERE IS EXPECTED TO BECOME MODERATELY
UNSTABLE. HOWEVER...THE DEGREE OF COVERAGE AND TIMING OF THIS IS
STILL QUITE UNCERTAIN. FOR NOW...PROB30S HAVE BEEN INTRODUCED FOR
THE 18-20Z TIME FRAME...WITH A TEMPO THROUGH 00Z. TS CHANCES WILL
CONTINUE THROUGH THE END OF THE PERIOD.
ELSEWHERE...DESPITE INCREASING LOW LEVEL MOISTURE...EXTENSIVE HIGH
CLOUDS ASSOCIATED WITH MISS/TENN VALLEY CONVECTION IS EXPECTED TO
KEEP COVERAGE OF FOG LIMITED THIS MORNING (EXCEPT PERHAPS ACROSS THE
MOUNTAIN VALLEYS WEST OF KAVL)...BUT HAVE INCLUDED A PERIOD OF MVFR
FOG AT KAND. A BACKDOOR COLD FRONT IS EXPECTED TO PUSH THROUGH KHKY
AROUND SUNRISE...AND MVFR CIGS ARE EXPECTED TO DEVELOP THERE BY
MID-MORNING OR SO. OTHERWISE...THE PRIMARY FORECAST CHALLENGE IS
TIMING AND OVERALL COVERAGE OF THUNDERSTORMS LATER TODAY. CHANCES
SHOULD GRADUALLY INCREASE THROUGHOUT THE DAY...AND HAVE RESERVED
CATEGORICAL SHOWERS FOR VERY LATE THIS AFTERNOON AND THIS EVENING...
WITH VCTS FAVORED EARLIER IN THE PERIOD.
OUTLOOK...PERIODS OF NUMEROUS/WIDESPREAD SHOWERS AND THUNDERSTORMS
AND ASSOCIATED RESTRICTION ARE EXPECTED FROM EARLY TUESDAY THROUGH
AT LEAST WEDNESDAY. DRIER WEATHER IS ANTICIPATED FOR LATE WEEK INTO
THE WEEKEND.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 100% HIGH 93% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 93% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 98% HIGH 100% HIGH 98%
KHKY HIGH 100% MED 79% HIGH 85% HIGH 93%
KGMU HIGH 100% HIGH 93% HIGH 100% HIGH 100%
KAND HIGH 97% HIGH 94% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...JAT/JDL/MCAVOY
SHORT TERM...PM
LONG TERM...WIMBERLEY
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
344 AM CDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT MON APR 28 2014
CURRENT WATER VAPOR IMAGERY SHOWS THE LOW IN THE MID LEVELS OF THE
ATMOSPHERE SPINNING AWAY RIGHT IN THE MIDDLE OF NEBRASKA...WITH THE
WELL ADVERTISED DRY SLOT ALOFT NOSING UP IN FRONT OF IT AND
ENCOMPASSING MUCH OF OUR FORECAST AREA. THE MOST PRONOUNCED DRYING
ALOFT IS ALONG THE I 29 CORRIDOR CURRENTLY. MODEL CONSENSUS IS GOOD
IN PROGGING THE LOW SLOWLY EASTWARD TOWARD SOUTHEAST IA BY VERY LATE
TONIGHT. THE SURFACE LOW FOLLOWS SUIT...AND IT LOOKS LIKE OUR ENTIRE
FORECAST AREA WILL BE PLACED NORTH OF THE WARM FRONT THROUGH TODAY
AND TONIGHT. THE BEST CHANCES FOR WIDESPREAD BENEFICIAL RAINFALL
TODAY WILL BE BEHIND THE INVERTED TROUGH WHICH WILL BE CONFINED TO
OUR FAR WESTERN ZONES APPROACHING CENTRAL SD. THE REST OF OUR AREA
WILL SEE LESS NUMEROUS SHOWERS AND RAINFALL. BUT THERE IS ENOUGH
ELEVATED INSTABILITY TO POP A THUNDERSTORM OR TWO ALMOST AT ANYTIME
THROUGHOUT THE ENTIRE DAY...ESPECIALLY WHEN A MICROSCALE AREA OF
WARM AIR ADVECTION DECIDES TO MOVE NORTHWARD WHICH THE MODELS CANNOT
HANDLE VERY WELL ON THAT SCALE. INTERESTINGLY...BOTH THE GFS AND GEM
PAINT A BROAD STRIPE OF DECENT QPF THIS AFTERNOON JUST NORTH OF THE
WARM FRONT FROM SIOUX CITY TO STORM LAKE. IN ADDITION...THE PAST FEW
RUNS OF THE HRRR ARE ALSO SHOWING THE POSSIBILITY OF DECENT
CONVECTION IN THOSE AREAS AGAIN DUE TO THE PROXIMITY OF THE WARM
FRONT JUST TO THE SOUTH. AT THIS TIME...IT LOOKS TOO STABLE FOR MUCH
IN THE WAY OF SEVERE WEATHER...AND ALSO THE WIND SHEAR IS NOT REAL
GREAT FROM SIOUX CITY TO STORM LAKE AS THE ENTIRE LOWEST 3
KILOMETERS HAS A WIND DIRECTION OUT OF THE EAST. ONE THING TO WATCH
FOR HOWEVER IS IF A ROGUE SEVERE STORM WHICH BLOWS UP FURTHER TO THE
SOUTHEAST NUDGES INTO THOSE AREAS BEFORE WEAKENING. TO THE
NORTH...KEPT THE COVERAGE OF POPS IN THE SCATTERED CATEGORY THIS
AFTERNOON ALONG THE I 29 CORRIDOR WHERE THE DRY SLOT ALOFT HAS THE
MOST IMPACT. BUT OTHER AREAS MAY START TO FILL IN MORE WITH RAINFALL
IN OUR FAR EAST AND INTO THE JAMES RIVER VALLEY FROM THE WEST AS
MOISTURE PROGS SATURATE UP BETTER ALOFT.
FEEL THERE IS NO NEED FOR A WIND ADVISORY TODAY AS SOUNDINGS ONLY
MIX TO ABOUT 925-900MB AREA WIDE. WINDS IN THAT LAYER ARE STOUT...
AVERAGING 30 TO 35 KNOTS...BUT USUALLY IT TAKES A LITTLE MORE THAN
THAT TO WARRANT A WIND ADVISORY IN OUR AREA...CLOSER TO 40 KNOTS.
HOWEVER TONIGHT ON THE BACK SIDE OF THE LOW...OUR FAR SOUTHWEST
ZONES MAY GET CLOSE TO ADVISORY CRITERIA AFTER MIDNIGHT. MUCH OF OUR
FORECAST AREA TONIGHT IS WELL PLACED IN THE UPPER LEFT QUADRANT OF
THE LOW TRACK TO RECEIVE PRECIP. THERE IS EVEN SOME WEAK TROWALING
IN THE 290-295K LAYER NUDGING INTO OUR AREA FROM THE EAST...AND
SATURATION LOOKS TO BE IN NO SHORT SUPPLY FROM THE SURFACE TO AROUND
500MB. IN THE EVENING...AGAIN THE I 29 CORRIDOR MAY NOT RECEIVE MUCH
RAIN...BUT PRECIP WILL FILL INTO THAT AREA OVERNIGHT. CONCERNING
TEMPERATURES...WITH A FEW BREAKS POSSIBLE NEAR THE WARM FRONT...
AREAS FROM YANKTON TO STORM LAKE AND SOUTHWARD SHOULD HIT 60 TO
65...PROGRESSIVELY COOLING OFF HEADING NORTHWARD. TONIGHT IS
TRICKY...AND HAD TO ADD IN A SNOW MIX TO OUR NORTHERN AND WESTERN
ZONES AS SURFACE TEMPERATURES COOL INTO THE MID 30S IN THOSE AREAS
COUPLED WITH SUB ZERO 850MB TEMPERATURES. USED THE MODEL CONSENSUS
850MB -2 DEGREE C AND 925MB ZERO DEGREE C ISOTHERMS FOR THE RAIN AND
SNOW LINES...COUPLED WITH TEMPERATURES NEAR 35.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM CDT MON APR 28 2014
TUESDAY WILL START FAIRLY RAINY OVER THE AREA...THOUGH AMOUNTS
SHOULD BE LESS THAN A QUARTER INCH FOR THE DAY. DRYING WILL BEGIN
FROM THE NORTH/NORTHEAST DURING THE AFTERNOON OVER THE WESTERN PART
OF THE FORECAST AREA AS SOME SUBSIDENCE SPREADS IN FROM THE NORTH/
NORTHEAST BETWEEN LOBES ROTATING AROUND THE UPPER LOW TO THE EAST.
FOR NOW WILL KEEP SOME VERY MINIMAL POPS IN THE WEST FOR TUESDAY
NIGHT...WHILE ONLY SHAVING POPS TO LOW LIKELIES ALONG OUR EASTERN
EDGE IN MN AND IA. FOR NOW AM GOING FOR ALL OF THIS PRECIPITATION TO
BE LIGHT RAIN EXCEPT MAYBE SOME MODERATE RAIN LINGERING TUESDAY
MORNING IN THE EAST...MAYBE WITH A BIT OF WET SNOW MIXED IN WEST AND
NORTH EARLY MORNING BUT NO ACCUMULATION. FOR TUESDAY NIGHT...THOUGH
TEMPERATURES ALOFT WILL BE MARGINAL FOR A LITTLE MIXED SNOW AGAIN...
THERE MAY BE NO PRECIPITATION AT ALL IN THE WEST WHICH WOULD HAVE
THE BETTER SHOT AT SOME SNOW. SURFACE AND NEAR SURFACE TEMPERATURES
WILL LIKELY BE A BIT TOO WARM WITH THE LIGHTER NATURE OF
PRECIPITATION...IF THERE IS ANY AROUND IN THE FIRST PLACE...AND
DYNAMIC COOLING WILL BE NIL. TO THE EAST...THE DEEPER MOIST AIR
SHOULD PRECLUDE ENOUGH COOLING TO GET SNOW TO THE SURFACE...AND EVEN
THERE THE PRECIPITATION SHOULD BE PRETTY LIGHT. TEMPERATURES WILL
NOT BE SHOWING A LOT OF SPREAD WITH 40S HIGHS AND 30S LOWS. IT WILL
STILL BE WINDY TUESDAY BUT EXPECT WINDS WILL STAY BELOW ADVISORY
CRITERIA.
WEDNESDAY WILL BRING THE NEXT LOBE ROTATING OVER THE AREA AND A
RESURGENCE OF LIGHT RAIN WEST/SOUTHWESTWARD AGAIN. TEMPERATURES
AGAIN WILL CLIMB INTO THE 40S AND IT WILL BE WINDY AGAIN. IT COULD
EVEN BE SLIGHTLY WINDIER THAN TUESDAY WITH THE LOBE PASSING OVER THE
AREA.
THURSDAY WILL BRING THE SYSTEM STARTING TO MOVE SLOWLY EAST OF THE
AREA AND WILL KEEP LIGHT RAIN POPS IN THE CHANCE CATEGORY. WEDNESDAY
NIGHT LOWS SHOULD BE IN THE 30S AGAIN...THOUGH IT MAY BE A DEGREE OR
TWO LESS COOL THERE WITH MODELS HINTING AT VERY SLIGHT LOW LEVEL
WARMING. WITH LESSER PRECIPITATION COVERAGE...THURSDAY DAY
TEMPERATURES ARE EXPECTED TO BE A TAD LESS COOL...UPPER 40S TO LOWER
50S FOR HIGHS. THIS PROCESS WILL CONTINUE ON FRIDAY...REMEMBER THE
SLOWNESS OF THIS SYSTEM...BUT POPS WILL BE PRETTY LOW WITH
PRECIPITATION CONFINED MAINLY TO EAST OF FSD. 50 TO 55 LOOKS RIGHT
FOR HIGHS FRIDAY.
THE WEEKEND SHOULD BE A LITTLE WARMER YET...BUT STILL BELOW
NORMAL...AHEAD OF A CANADIAN WAVE APPROACHING IN NORTHWEST FLOW
BEHIND THE CURRENT SYSTEM. WILL GO WITH THE EXTENDED GUIDANCE GRIDS
OF SHOWER CHANCE PEAKING ABOUT SATURDAY NIGHT. THIS SEEMS TO BE THE
BEST PLAN FOR NOW ON EITHER THE GFS OR EC SOLUTION. THE EC HAS
STRONGER RIDGING BETWEEN SYSTEMS THAN THE GFS AND WOULD BRING
TEMPERATURES A LITTLE CLOSER TO NORMAL FOR THE WEEKEND...BUT THE
LIGHT SHOWER THREAT IS STILL THERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1120 PM CDT SUN APR 27 2014
WIDESPREAD CEILINGS AROUND 500 TO 1500 WILL BE THE MAIN STORY THROUGH
THE PERIOD. SOME VFR CEILINGS NEAR THE MISSOURI VALLEY WILL QUICKLY
GIVE WAY TO LOW STRATUS THROUGH THE NEXT FEW HOURS...WITH SHOWERS AND
THUNDERSTORMS PUSHING INTO SOUTH CENTRAL SD INTO THE EARLY MORNING
HOURS. CEILINGS AND VISIBILITY WILL FURTHER DROP IN ANY SHOWERS AND
STORMS. STRATUS STICKS AROUND THROUGHOUT THE DAY ON MONDAY...WITH THE
ONLY POTENTIAL LIFTING OF CEILINGS ABOVE 3000 EXPECTED NEAR THE
MISSOURI RIVER ONCE AGAIN. ADDITIONAL SHOWER ACTIVITY SPREADS FROM
WEST TO EAST MAINLY 15Z THROUGH THE END OF THE TAF PERIOD. WINDS
WILL REMAIN GENERALLY EASTERLY AND BREEZY AROUND 15 TO 25 KT WITH
GUSTS TO 32 KT...BUT WILL BEGIN TO SHIFT NORTHEAST THEN NORTH ACROSS
OUR WESTERN HALF AFTER 21Z. A LULL IN THE WINDS WILL DEVELOP ON
MONDAY NEAR THE MISSOURI VALLEY. ISOLATED STRONGER OR SEVERE STORMS ARE
ALSO POSSIBLE MONDAY AFTERNOON AND EVENING MAINLY NEAR THE MISSOURI
VALLEY...WITH HAIL AND GUSTY WINDS POSSIBLE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1152 PM MDT SUN APR 27 2014
.UPDATE...
ISSUED AT 1147 PM MDT SUN APR 27 2014
RAIN HAS CHANGED TO SNOW ACROSS NORTHWESTERN SOUTH DAKOTA. EXPECT
SNOWFALL TO CONTINUE INTO MONDAY MORNING WITH AMOUNTS OF 2 TO 5
INCHES. THUS DELAYED THE WIND ADVISORY UNTIL 18Z AND STARTED A
WINTER WEATHER ADVISORY FOR NORTHWESTERN SOUTH DAKOTA THAT GOES
UNTIL 18Z.
UPDATE ISSUED AT 939 PM MDT SUN APR 27 2014
DECIDED TO START HIGH WIND WARNING SINCE THE AREA IN THE WATCH WAS
ALREADY IN WARNING CRITERIA...KRAP GUST TO 52KT AT 0202Z. LOOKING
AT LATEST HI RES MODEL GUIDANCE...HRRR AND RAP...LOOKS LIKE 30 TO 40
MPH WINDS WILL CONTINUE THRU THE NIGHT BEFORE REALLY PICKING UP BY
13Z MONDAY. SEEING VERY STRONG DOWNSLOPE WINDS FROM THE BLACK
HILLS IN THE HIGH WIND WARNING AREA. COULD SEE SOME LIGHTER WINDS
OVERNIGHT...HOWEVER SINCE WE WERE ALREADY HAVING HIGH WINDS AND
CONFIDENCE IN HIGH WINDS FOR MONDAY AND TUESDAY WERE
HIGH...DECIDED TO GO WITH THE WARNING.
UPDATE ISSUED AT 822 PM MDT SUN APR 27 2014
DECIDED TO PUT OUT A WINTER WEATHER ADVISORY FOR SNOW FOR SHANNON
AND BENNETT COUNTIES. MADE A FEW CALLS AND LOOKING AT WEBCAMS
MARTIN ALREADY HAD AN INCH AND PINE RIDGE HAD A COUPLE INCHES.
LATEST RAP MODEL AND HRRR BOTH INDICATE A TROWAL SETTING UP OVER
THIS AREA TONIGHT. EXPECT A BAND OF HEAVY SNOW WITH AMOUNTS OF 2
TO 5 INCHES FOR THIS AREA. ONLY HAVE THE ADVISORY TIL 12Z...BUT
SNOW MAY CONTINUE A BIT LONGER. ONCE THE SNOW STOPS THE WINDS WILL
START IN THIS AREA SO KEPT WIND ADVISORY BEGINNING AT 12Z. NEXT
SHIFT MAY HAVE TO ADJUST THE TIMING DEPENDING ON THE SNOWFALL.
UPDATE ISSUED AT 640 PM MDT SUN APR 27 2014
LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER
CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER
WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM
RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS.
THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE
RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40
MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED
AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE
INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST
COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A
WIND ADVISORY OR HIGH WIND WARNING.
OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN
HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES
OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND
WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME.
&&
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 219 PM MDT SUN APR 27 2014
CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN
NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME
STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH
THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF
STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY
THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF
WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS
ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A
BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING
THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL
CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING
THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS
CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER
SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW
EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE
ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN
CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP
THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE
REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT
NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS
TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE
THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN
RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED.
ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH
PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO
THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER
THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE
MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK
HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR
THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE
RAIN IN THE AFTERNOON.
MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER
OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A
PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP
RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE
SYSTEM SLOWLY PUSHING EAST.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 219 PM MDT SUN APR 27 2014
CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE
PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE
TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS
EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE
FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT
SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE
REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL
LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE
BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF
THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY
NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD
THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN
THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A
PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE
AGAIN...ESP IN THE HIGHER TERRAIN.
TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT
RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY
TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV
INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH
STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT
FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE
GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS.
MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN
BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN
INCH OR SO.
THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW
CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE
INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK
HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT
THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY
AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY
OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR
SOME SNOW ACCUMS.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT
ISSUED AT 1119 PM MDT SUN APR 27 2014
RAIN AND SNOW SHOWERS WILL CONTINUE THROUGH THE PERIOD WITH
WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS.
DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF
THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE
OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY
MONDAY MORNING. A DRY SLOT WILL BRING VFR CONDITIONS TO PORTIONS
OF NE WYOMING AND SOUTH CENTRAL SOUTH DAKOTA THROUGH 12Z.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR SDZ042-044.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM
CDT/ TUESDAY FOR SDZ013-014-027-032-041>044-046-047-049.
WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ001-002-012-
025.
WIND ADVISORY FROM NOON MONDAY TO 6 PM MDT TUESDAY FOR SDZ001-
002-012-025.
HIGH WIND WARNING UNTIL 6 PM MDT TUESDAY FOR SDZ026-030-031-
072>074.
WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057.
&&
$$
UPDATE...MLS
SHORT TERM...77
LONG TERM...JC
AVIATION...MLS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1122 PM MDT SUN APR 27 2014
.UPDATE...
ISSUED AT 939 PM MDT SUN APR 27 2014
DECIDED TO START HIGH WIND WARNING SINCE THE AREA IN THE WATCH WAS
ALREADY IN WARNING CRITERIA...KRAP GUST TO 52KT AT 0202Z. LOOKING
AT LATEST HI RES MODEL GUIDANCE...HRRR AND RAP...LOOKS LIKE 30 TO 40
MPH WINDS WILL CONTINUE THRU THE NIGHT BEFORE REALLY PICKING UP BY
13Z MONDAY. SEEING VERY STRONG DOWNSLOPE WINDS FROM THE BLACK
HILLS IN THE HIGH WIND WARNING AREA. COULD SEE SOME LIGHTER WINDS
OVERNIGHT...HOWEVER SINCE WE WERE ALREADY HAVING HIGH WINDS AND
CONFIDENCE IN HIGH WINDS FOR MONDAY AND TUESDAY WERE
HIGH...DECIDED TO GO WITH THE WARNING.
UPDATE ISSUED AT 822 PM MDT SUN APR 27 2014
DECIDED TO PUT OUT A WINTER WEATHER ADVISORY FOR SNOW FOR SHANNON
AND BENNETT COUNTIES. MADE A FEW CALLS AND LOOKING AT WEBCAMS
MARTIN ALREADY HAD AN INCH AND PINE RIDGE HAD A COUPLE INCHES.
LATEST RAP MODEL AND HRRR BOTH INDICATE A TROWAL SETTING UP OVER
THIS AREA TONIGHT. EXPECT A BAND OF HEAVY SNOW WITH AMOUNTS OF 2
TO 5 INCHES FOR THIS AREA. ONLY HAVE THE ADVISORY TIL 12Z...BUT
SNOW MAY CONTINUE A BIT LONGER. ONCE THE SNOW STOPS THE WINDS WILL
START IN THIS AREA SO KEPT WIND ADVISORY BEGINNING AT 12Z. NEXT
SHIFT MAY HAVE TO ADJUST THE TIMING DEPENDING ON THE SNOWFALL.
UPDATE ISSUED AT 640 PM MDT SUN APR 27 2014
LATEST HRRR MODEL AND SURFACE ANALYSIS SHOWS A LEE MESO-LOW OVER
CENTRAL CUSTER COUNTY. THE ISOBARS SHOW A TIGHT GRADIENT OVER
WESTERN FALL RIVER COUNTY AND ALONG THE EASTERN FOOTHILLS FROM
RAPID CITY TO HERMOSA AND ABOUT 60 MILES EAST ONTO THE PLAINS.
THIS FEATURE IS PROGGED TO CONTINUE THROUGH 02Z-03Z THIS EVENING. THE
RESULT WILL BE A BRIEF PERIOD OF GUSTY NORTHWEST WINDS OF 35 TO 40
MPH AND GUSTS UP TO 55 MPH. SINCE THIS FEATURE IS VERY LOCALIZED
AND WILL BE SHORT LIVED WITH WINDS DIMINISHING AFTER 03Z BEFORE
INCREASING AGAIN EARLY MONDAY MORNING...THOUGHT IT WOULD BE BEST
COVERED WITH A SPECIAL WEATHER STATEMENT INSTEAD OF GOING WITH A
WIND ADVISORY OR HIGH WIND WARNING.
OTHERWISE THE FORECAST IS ON TRACK...AM WATCHING THE NORTHERN
HILLS CLOSELY SINCE SOME AREAS HAVE ALREADY PICKED UP A FEW INCHES
OF SNOW. HOWEVER WINTER STORM WARNING AT THE HIGHER ELEVATIONS AND
WINTER WEATHER ADVISORY AROUND SPEARFISH LOOK TO BE GOOD AT THIS TIME.
&&
.SHORT TERM...THIS EVENING THROUGH MONDAY NIGHT
ISSUED AT 219 PM MDT SUN APR 27 2014
CURRENT SURFACE ANALYSIS PLACES LOW OVER NWRN KANSAS/SWRN
NEBRASKA...WHILE UPPER LEVEL ANALYSIS INDICATES LOW HAS BECOME
STACKED. TWO MAIN AREAS OF PRECIP HAVE DEVELOPED OVER THE CWA WITH
THE FIRST ONE ORIENTATED N/S ALONG THE WRN SD BORDER ALONG AREA OF
STRONG MID-LEVEL FRONTOGENESIS WHILE SECONDARY AREA OF PRIMARILY
THUNDERSTORMS CONTINUES TO PUSH W/NWRLY NEAR NOSE OF JET STREAK.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...A POTPOURRI OF
WEATHER TYPES ARE EXPECTED AS STRONG LOW PRESSURE SYSTEM CREEPS
ITS WAY THROUGH THE REGION. LATEST GUIDANCE KEEPING THE SYSTEM A
BIT FURTHER SOUTH THAN PREVIOUSLY THOUGHT WITH LOW SLOWLY SHIFTING
THROUGH THE NIGHT TOWARDS CTRL NEBRASKA. PLENTY OF MOISTURE WILL
CONTINUE TO WRAP INTO THE SYSTEM KEEPING PRECIPITATION GOING
THROUGH THE NIGHT. KEY FORECAST CHALLENGE IS PRECIP TYPES. APPEARS
CHANGEOVER TO SNOW HAS OCCURRED OVER THE BLKHLS FOLLOWING A COOLER
SOLUTION GIVEN THE SOUTHERN TREND OF THE MODELS. WITH SNOW
EXPECTED TO CONTINUE GIVEN LARGE SCALE FORCING ALONG WITH UPSLOPE
ENHANCEMENT HAVE UPGRADED TO WINTER STORM WARNING. TOWARDS THE ERN
CWA MODELS CONTINUE TO INDICATE MODEST INSTABILITY SO WILL KEEP
THUNDERSTORM CHANCES GOING INTO EVENING. THE TRICKY PART IS THE
REMAINDER OF THE CWA WHERE TEMPERATURES ARE EXPECTED TO BE RIGHT
NEAR THE RAIN/SNOW TRANSITION. HAVE KEEP SNOW ACCUMULATIONS
TONIGHT OVER THE PLAINS ON THE LIGHTER SIDE BUT WILL RE-EVALUATE
THIS THRU THE AFTERNOON/EVE BECAUSE IF ENOUGH COLD AIR PULLS IN
RESULTING IN AN EARLY TRANSITION MORE SNOW WILL NEED TO BE ADDED.
ON MONDAY...LOW SLOWLY LOITERS ITS WAY TOWARDS ERN NEBRASKA WITH
PRECIPITATION CONTINUING TO AFFECT THE AREA. NEW CONCERN ADDED TO
THE EQUATION WILL BE WINDS WITH PRESSURE GRADIENT TIGHTENING OVER
THE AREA. GUSTY WINDS WILL BE ON THE INCREASE IN THE
MORNING...WITH THE STRONGEST WINDS OVER THE ERN SIDE OF THE BLACK
HILLS. PRECIP TYPES REMAIN TRICKY GIVEN THE TEMPS REMAINING NEAR
THE TRANSITION...BUT CURRENTLY LOOKS AS IF MOST AREAS SHOULD BE
RAIN IN THE AFTERNOON.
MONDAY NIGHT...LOW WORKS ITS WAY TOWARDS THE IOWA/MISSOURI BORDER
OVERNIGHT. EXPECT COOLER AIR TO WORK INTO THE SYSTEM BRINGING A
PROBABLE TRANSITION TOWARDS SNOW TO MOST AREAS...THOUGH PRECIP
RATES SHOULD BE LOWER...PARTICULARLY OVER THE FAR WRN CWA WITH THE
SYSTEM SLOWLY PUSHING EAST.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
ISSUED AT 219 PM MDT SUN APR 27 2014
CLOSED UPPER LOW WILL SLOWLY MEANDER EAST IN THE
PERIOD...SUPPORTING SEMI-BLOCKED FLOW. HEAVY NON-PROGRESSIVE
TENDENCIES FAVORED IN THE PERIOD WITH COOL BELOW NORMAL TEMPS
EXPECTED. LINGERING WANING DEFORMATION ZONE WILL BE PRESENT OVER THE
FA AT THE START OF THE PERIOD...SUPPORTING SNOW ACCUMULATIONS AT
SOME LOCATIONS. ALTHOUGH THIS SYSTEM WILL SHIFT EAST SLOWLY THE
REMAINDER OF THE PERIOD...CYCLONIC FLOW WITH STEEP LAPSE RATES WILL
LINGER THROUGH MUCH OF THE PERIOD BEFORE THE WESTERN NOAM RIDGE
BEGINS TO EDGE EAST. HOWEVER...GIVEN THE HIGH AMPLITUDE NATURE OF
THE UPPER RIDGE...WITH HIGH LATITUDINAL EXTENT...LONG TRAJECTORY
NORTHERLY FLOW WILL SET THE STAGE FOR ANOTHER INTRUSION OF CP TOWARD
THE END OF THE PERIOD. THIS HAS FAVORED A DOWNWARD TREND IN TEMPS IN
THE SUNDAY PERIOD. GIVEN H85 TEMPS IN THE -2 TO 0C RANGE WITH A
PASSING DISTURBANCE...SNOW ACCUMS MAY BE A POSSIBILITY ONCE
AGAIN...ESP IN THE HIGHER TERRAIN.
TUE-THU...LINGERING DEFORMATION ZONE WILL SUPPORT CHANCES FOR LIGHT
RAIN/SNOW...ESP IN THE TUE PERIOD...WITH A HEAVY WANE IN ACTIVITY
TOWARD WED GIVEN EAST PROPAGATION OF THE UPPER LOW WITH DRY AIR ADV
INTO THE FA FORM THE NORTH. HOWEVER...LINGERING CYCLONIC FLOW WITH
STEEP LL LAPSE RATES AND AVAILABLE LL MOISTURE WILL BE SUFFICIENT
FOR A FEW SHOWERS INTO THUR. ADJUSTED TEMPS DOWN SOME...ESP TUE
GIVEN PRECIP WITH AMPLE CLOUD CLOVER AND COOL THERMAL FIELDS.
MODERATE SNOW ACCUMS ARE EXPECTED INTO TUE MORNING OVER THE NORTHERN
BLACK HILLS...WITH SOME LIGHT ACCUMS ON THE SD PLAINS...UP TO AN
INCH OR SO.
THU-SUN...SLIGHT WARMING TREND THROUGH FRIDAY WITH LINGERING LOW
CHANCES FOR SHOWERS THU. RIDGE FRONT DISTURBANCE LOOKS TO SHIFT SE
INTO THE REGION FRI...POSSIBLY SUPPORTING A FEW SHOWERS WITH PEAK
HEATING. OTHERWISE...A POTENTIALLY STRONGER SYSTEM LOOKS TO AFFECT
THE REGION INTO THE WEEKEND...BRING MORE COOLER WEATHER BY SUNDAY
AND THE CHANCE FOR RAIN AND/OR SNOW ONCE AGAIN. GIVEN AVAILABILITY
OF COLD AIR PER HIGH LATITUDE RIDGING...THE POTENTIAL WILL EXIST FOR
SOME SNOW ACCUMS.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT
ISSUED AT 1119 PM MDT SUN APR 27 2014
RAIN AND SNOW SHOWERS WILL CONTINUE THROUGH THE PERIOD WITH
WIDESPREAD IFR CONDITIONS OVER THE BLACK HILLS AND SD PLAINS.
DOWNSLOPING SHOULD CONFINE CIGS TO MVFR AT KRAP THROUGH MOST OF
THE PERIOD. GUSTY NORTHWESTERLY WINDS WILL CONTINUE TO INCREASE
OVERNIGHT WITH SURFACE WINDS OF 50KT POSSIBLE AROUND KRAP BY
MONDAY MORNING. A DRY SLOT WILL BRING VFR CONDITIONS TO PORTIONS
OF NE WYOMING AND SOUTH CENTRAL SOUTH DAKOTA THROUGH 12Z.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR SDZ024-028.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR SDZ042-044.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ MONDAY TO 6 PM MDT /7 PM
CDT/ TUESDAY FOR SDZ001-002-012>014-025-027-032-041>044-046-
047-049.
HIGH WIND WARNING UNTIL 6 PM MDT TUESDAY FOR SDZ026-030-031-
072>074.
WINTER WEATHER ADVISORY UNTIL NOON MDT MONDAY FOR SDZ025.
WY...WINTER STORM WARNING UNTIL NOON MDT MONDAY FOR WYZ057.
&&
$$
UPDATE...MLS
SHORT TERM...77
LONG TERM...JC
AVIATION...MLS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1245 AM CDT MON APR 28 2014
.UPDATE...FOR 06Z TAFS.
&&
.AVIATION...
SIGNIFICANT SYSTEM TO CROSS THE MID-SOUTH THE NEXT 18-24 HOURS.
SHWRS/STMS EXPECTED TO AFFECT ALL SITES OFF AND ON THROUGH
THE PERIOD...WHICH WILL BRING VARYING CONDITIONS. BEST CHANCE
FOR STRONGEST STORMS LOOKS TO BE THE 18-03Z RANGE MON-TUE. STORMS
WILL CONTAIN VERY HEAVY RAIN WHICH WILL GREATLY REDUCES VSBYS AND
POSSIBLY CIGS. STRONG STMS LIKELY TO CONTAIN 30-40+KT WIND GUSTS
AS WELL.
&&
.PREV DISCUSSION... /ISSUED 1009 PM CDT SUN APR 27 2014/
UPDATE...
SHOWER AND ISOLATED TSTM ACTIVITY NOW CONFINED TO GENERALLY THE
NORTHEASTERN HALF OF THE MID STATE. LATEST HRRR SHOWS
REDEVELOPMENT OVER OUR NORTHWESTERN COUNTIES AROUND 3 OR 4 AM IN
THE MORNING. THE ACTIVITY AT THAT TIME STILL DOES NOT LOOK SEVERE.
ELSEWHERE...JUST SCT ACTIVITY IS POSSIBLE.
MODELS ARE IN AGREEMENT WITH A BUILDUP OF SUBSIDENCE TOWARD 12Z
OVER WESTERN TN. SO...ONSET OF SEVERE MAY HOLD OFF UNTIL AFTER THE
12Z-15Z WINDOW.
FOR THIS NEXT UPDATE...WILL BE LOWERING POPS FOR THE REMAINDER OF
THE OVERNIGHT. BUT...WILL AT LEAST MAINTAIN LIKELY POPS FOR MUCH
OF THE NORTHWEST. ELSEWHERE...WILL GENERALLY KEEP POPS IN THE CHC
CATEGORY.
OTW...LOW TEMPS LOOK FINE AS DEWPOINTS WILL REMAIN NEARLY STEADY.
FOR THE REMAINDER OF THE OVERNIGHT...IT DOES NOT LOOK AS THOUGH ANY
SEVERE WEATHER WILL HIT US. BUT...THAT WILL CHANGE AFTER 12Z-15Z.
PREV DISCUSSION... /ISSUED 805 PM CDT SUN APR 27 2014/
DISCUSSION...
CURRENT RADAR IMAGERY SHOWING A LARGE AMOUNT OF REFLECTIVITY
COVERAGE IN THE FORM OF SHOWERS AND NON SEVERE TSTMS. MODELS SHOW
THAT AN INCREASE IN MOISTURE DEPTH IS EXPECTED THIS EVENING AND
OVERNIGHT. WILL GO AHEAD AND UP POPS AREA WIDE.
OTW...IN TERMS OF THE SEVERE POTENTIAL ANALYSIS...LATEST SOUNDING FOR OHX
IS IN NOW. CURRENT LI IS + 1.8 AND SUPPORTS THE RELATIVELY STABLE
CONDITIONS ACROSS MIDDLE TN AT THIS TIME. THE FURTHER WEST YOU GO
HOWEVER...INSTABILITIES DO INCREASE. THE CLOSEST SEVERE WARNINGS
ARE ACROSS NW MS AND THE BOOTHEEL OF MO. THE ACTIVITY LOOKS
ESPECIALLY NASTY IN THE CENTRAL AR AREA. MODELS IN AGREEMENT AND
SUPPORT INCREASINGLY UNSTABLE AIR THE FURTHER WEST YOU GO.
THROUGH 12Z...WE REALLY SEE NO INCREASE IN INSTABILITY LEVELS OVER
MIDDLE AND EASTERN AREAS OF THE MID STATE. HOWEVER...OVER THE
WESTERN QUARTER OR SO OF MIDDLE TN...WE DO SEE A SUBSTANTIAL
DECREASE IN SHOWALTER VALUES. THE MID AND LOW LEVEL JET DYNAMICS
WILL BE ON THE INCREASE OVER WESTERN TN OVERNIGHT AS WELL. ALL IN
ALL...LOOKS LIKE NON SEVERE TSTMS OVERNIGHT EXCEPT AS WE APPROACH
12Z...THE RISK OF SEVERE WILL BEGIN TO INCREASE OVER OUR FAR
WESTERN AREAS.
AGAIN...WILL UP THE POPS FOR ALL AREAS FOR TONIGHT. UPDATES WILL
BE SENT SHORTLY.
PREV DISCUSSION... /ISSUED 717 PM CDT SUN APR 27 2014/
UPDATE...FOR 00Z TAFS.
AVIATION...
SIGNIFICANT SYSTEM TO CROSS THE MID-SOUTH THE NEXT 24 HOURS.
SHWRS/STMS EXPECTED TO AFFECT ALL SITES OFF AND ON THROUGH
THE PERIOD...WHICH WILL BRING A MULTITUDE OF VARYING CONDITIONS.
BEST CHANCE FOR STRONGEST STORMS LOOKS TO BE THE 15-00Z RANGE
MONDAY. STORMS WILL CONTAIN VERY HEAVY RAIN WHICH WILL GREATLY
REDUCES VSBYS AND POSSIBLY CIGS. STRONG STMS LIKELY TO CONTAIN
40+KT WIND GUSTS AS WELL.
PREV DISCUSSION... /ISSUED 355 PM CDT SUN APR 27 2014/
AS OF 3 PM...ISOLATED SHOWERS AND STORM DEVELOPMENT CONTINUED NORTH
OF THE WARM FRONT AND ITS ASSOCIATED CONVECTION. THE FRONT HAS BEEN
VERY SLUGGISH TO PROGRESS NORTHWARD...AND AS A RESULT...HAS RESULTED
IN SOME FLASH FLOODING CONCERNS IN NORTHERN MS. THIS ACTIVITY SHOULD
CONTINUE TO INCH NORTH THROUGH THE LATE AFTERNOON AND EVENING. STILL
THINK THAT HEAVY RAINS...FREQUENT CG STRIKES...AND SOME SMALL
HAIL/GUSTY WINDS WILL BE THE THREATS UNTIL NIGHTFALL...THEN ACTIVITY
SHOULD MELLOW AS IT EXITS NORTH OF THE STATE LINE.
REGARDING THE FORECAST SEVERE LINE OF STORMS THAT HAS BEEN
ADVERTISED FOR THE LAST FEW DAYS...HRRR/RAP/WRF HI RES MODELS
CONTINUE TO INDICATE A SEVERE LINE OF STORMS THAT SHOULD REACH THE
TN RIVER WELL AFTER MIDNIGHT. ALL THE DETERMINISTIC MODELS BLOW
THIS SQUALL LINE THROUGH THE MID STATE BY LATE MORNING MONDAY.
FOR THE PERIOD 18Z MONDAY THROUGH 06Z TUESDAY...
THIS CONTINUES TO BE THE TIMEFRAME IN WHICH THE HIGHEST POTENTIAL
FOR SEVERE WEATHER APPEARS TO BE. THE POTENTIAL FOR A WIDESPREAD
SEVERE WEATHER OUTBREAK INCLUDING VERY LARGE HAIL AND
STRONG...POTENTIALLY NUMEROUS...TORNADOES CONTINUES TO EXIST.
AFTER CLOSE EXAMINATION OF THE DETERMINISTIC MODELS...THE ONLY
NOTABLE DIFFERENCE FROM PREVIOUS FORECASTS APPEARS TO BE A
SOMEWHAT EARLIER POSSIBLE CONVECTIVE INITIATION TIMING ESTIMATE.
12Z-15Z FORECAST SOUNDINGS INDICATE VERY RAPID WARMING AND RAPIDLY
INCREASING INSTABILITY PARAMETERS FOR THE WESTERN HALF OF THE MID
STATE. SIMULTANEOUSLY...THE RIGHT EXIT REGION OF A 250 MB JET STREAK
WILL BE DEVELOPING OVER THE MS RIVER AND SHOULD BE AROUND THE TN
RIVER BY 18Z. OMEGA FIELDS ECHO THE IMPLIED DEEP LAYER LIFT
DEVELOPING IN WESTERN TN IN THE MORNING AND A VERY STRONG DYNAMIC
AND RAPIDLY DEVELOPING CONVECTIVE SET UP LOOKS TO BE IN STORE FOR
THE WESTERN TN AND WESTERN MIDDLE TENNESSEE AREAS. THE BIGGEST
QUESTION AROUND THIS TIME IS WHERE IN FACT CI WILL TAKE PLACE...AND
INTERROGATING SUBTLETIES IN THE WIND FIELDS OF ALL THE PROGGED SFC
WIND FIELDS...A SUBTLE SURFACE CONFLUENCE ZONE LOCATED JUST WEST OF
THE TN RIVER MAY BE THE LOCATION THAT THIS CI TAKES PLACE.
CONFIDENCE IS QUITE LOW IN THAT REGARD HOWEVER.
AFTER CI TAKES PLACE...THESE CELLS SHOULD BEGIN TAKING SUPERCELL
STRUCTURE AND STEERING FLOW SHOULD BE EAST NORTHEASTERLY AT ABOUT
40-50 KTS. THIS WOULD PUT ALL OF MIDDLE TENNESSEE IN THE PATH OF
VERY STRONG SUPERCELLS SHOULD THIS OUTCOME COME TO FRUITION. IF
EVERYTHING GOES AS INDICATED IN THE MODELS...THE 21Z TO 03Z
TIMEFRAME LOOKS TO BE THE TIMEFRAME OF PEAK THREAT.
OVERALL FORECAST LIMITING FACTORS...SOME OF THE VARIABLES THAT
CONTINUE TO COMPLICATE THE FORECAST. THERE IS LOWER CONFIDENCE IN
THE HI RES MODELS OF LATE DUE TO ITS INABILITY TO ACCURATELY
HANDLE THE CONVECTION FROM TODAY. THIS MAKES THE SQUALL LINE
POTENTIAL FOR TONIGHT MORE QUESTIONABLE HOWEVER THERE ARE STILL A
FEW MORE HOURS OF POTENTIAL DEVELOPMENT OUT WEST.
ADDITIONALLY...THE LARGE AMOUNTS OF RAINFALL THAT HAS BEEN
OBSERVED IN NORTHERN MS AND WESTERN TN MAY KEEP THE LOW LEVEL
ATMOSPHERE QUITE MOIST TOMORROW AND THUS KEEP LOW LEVEL CLOUD
COVER IN THE AREA IF THE PREVIOUSLY FORECAST SQUALL LINE DOES NOT
COME TO FRUITION AND CLEAR EVERYTHING OUT. THIS WOULD RESULT IN
INHIBITED INSTABILITY AND DELAY STORM DEVELOPMENT INTO THE LATER
AFTERNOON. WITH THE MULTITUDE OF VARIABLES UNKNOWN DUE TO ONGOING
CONVECTION...THESE LIMITING FACTORS ARE DIFFICULT TO ASSESS.
ADDITIONALLY...PWAT VALUES SHOULD STAY WELL ABOVE NORMAL THROUGHOUT
THE NEXT 48 HOURS. SO IN ADDITION TO THE SEVERE WEATHER
POTENTIAL...HEAVY RAIN POTENTIAL AND POSSIBLE FLASH FLOODING WILL BE
A SIGNIFICANT THREAT. HPC IS INDICATING AROUND 5 INCHES OF RAIN FROM
00Z TONIGHT THROUGH 00Z WEDNESDAY. NOTE HOWEVER THAT A LARGE PORTION
OF THIS RESTS ON WHETHER TONIGHTS STORM SYSTEM DEVELOPS AS FORECAST
IN THE SHORT RANGE MODELS.
BEYOND 06Z TUESDAY...LEFT FORECAST BASICALLY UNCHANGED WITH
ANOTHER POTENTIAL ROUND OF STRONG TO SEVERE WEATHER POSSIBLE
TUESDAY AFTERNOON AND EVENING. PREFER NOT TO ADD ANY MORE DETAILS
TO THIS FORECAST WITHOUT SEEING HOW TOMORROW UNFOLDS FIRST AS IT
WILL DIRECTLY IMPACT WHAT HAPPENS TUESDAY. BUT FOR WHAT ITS
WORTH...SPC HAS DOWNGRADED TUESDAYS THREAT FOR MIDDLE TENNESSEE TO
ONLY GENERAL THUNDERSTORMS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
421 AM CDT MON APR 28 2014
.DISCUSSION...
BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC
TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE
TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE
SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/
THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO
HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB
IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT
TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE
UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A
GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST
BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS
INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW
FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN.
SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE
PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY
TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS
SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS.
THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD
UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE
PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD
KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN
THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS
QUITE DRY THRU THE 1ST WEEK OF MAY. 47
&&
.MARINE...
WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION
FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS.
GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF
THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE
COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO-
NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN
WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY
FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE
FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41
&&
.AVIATION...
HAVING TO KEEP AN EYE ON DEVELOPMENT OUT TO OUR W/NW THRU THE MORN-
ING HOURS. PROBABLY CANNOT AVOID THE MENTION OF THUNDER IN THE NRN
HALF TAF SITES (CLL/UTS/CXO/IAH) THIS MORNING UNTIL THIS AFTN. THE
APPROACH/PASSAGE OF THE PACIFIC FRONT (IN WHICH THIS PCPN IS FOCUS-
ING ON) SHOULD BRING DRIER AIR AND VFR CONDITIONS TO THE AREA LATE
THIS AFTN/TONIGHT. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 90 59 82 51 75 / 20 10 10 0 0
HOUSTON (IAH) 91 62 86 55 78 / 50 10 10 0 0
GALVESTON (GLS) 84 71 84 62 77 / 50 10 20 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 AM CDT THIS MORNING
FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
326 AM CDT MON APR 28 2014
.SHORT TERM (TODAY THROUGH TUESDAY)...WARM AND DRY TODAY AND TUESDAY
TOO (MOST AREAS)...AS COLD AIR IS EXPECTED TO LAG BEHIND THE FRONTAL
BOUNDARY ON TUESDAY. LOOKS LIKE ANOTHER HOT DAY...BUT NOT AS HOT AS
YESTERDAY AT LEAST OUT TO THE WEST AS BOUNDARY LAYER TEMPERATURES
ARE PROGGED TO BE SEVERAL DEGREES COOLER (SO IF THAT HAPPENS IT
SHOULD BE COOLER). 4KM RUC IS SHOWING TEMPERATURES TOPPING 100
DEGREE BARRIER OVER THE SOUTHERN AREAS...AND WILL GO 101/102 OVER
THE SOUTHWESTERN AREAS. OTHERWISE...MORNING LOW CLOUDS OVER THE EAST
WILL QUICKLY LIFT AND SHOULD SEE LOTS OF SUN WITH NORTHWEST WINDS AS
DRY LINE MOVES FARTHER EAST THAN YESTERDAY. LOW LEVEL MOISTURE IS
TOO SCOURED OUT FOR ANY MENTION OF RAIN (EVEN OFFSHORE) SO HAVE
REMOVED (4KM MODELS KEEP THINGS DRY TOO). FOR TONIGHT...ONLY NAM IS
BRINGING COOLER AIR MUCH FASTER THAN GFS/ECMWF (ALTHOUGH CANADIAN IS
COOL TOO...AS USUAL). AM GOING TO PREFER TO GO MORE ON THE WARM SIDE
TONIGHT ALTHOUGH IF WINDS ARE TOO LIGHT AND SURFACE MOISTURE IS TOO
LOW...WE COULD REALLY BOTTOM OUT (GIVEN WARM DAY EXPECTED TODAY WILL
PREFER TO STAY ON THE WARM SIDE THOUGH). COOLER AGAIN ON TUESDAY BUT
STILL WARMER THAN NORMAL WITH COLD AIR LAGGING ON FRONT. MAY SEE A
FEW 80S IN THE VICTORIA AREA. MOISTURE AGAIN TOO LIMITED FOR
PRECIPITATION.
&&
.MARINE (TODAY THROUGH TUESDAY)...HAVE EXTENDED THE SCA TIL 4 AM FOR
THE BAYS/WATERWAYS...AND LONGER FOR THE GULF WATERS. MAY NEED TO
EXTEND AGAIN AT THE LAST MINUTE IF WINDS STAY UP AGAIN. WINDS HAVE
STAYED UP LONGER THAN EXPECTED WITH GUSTS OVER 30 KNOTS AT KNGP.
4KM RUC HAS WINDS CRANKING TIL 12Z OR SO...BUT THIS IS NORMALLY ON
THE HIGH SIDE (BUT STILL DOING BETTER THAN NAM12 OR OTHER MODELS).
WINDS DO DECREASE BY SUNRISE...BUT SEAS STAY UP. THUS...THE GULF
WATER SCA WILL MAINLY BE FOR HIGH SEAS MONDAY...WITH SCA
CONDITIONS ENDING AROUND NOON. VISIBILITIES OVER THE MARINE AREAS
ARE BETWEEN 1 AND 3 MILES...AND THAT SHOULD CLEAR UP LATER THIS
MORNING. MORE FOG TONIGHT BUT THAT SHOULD BE OVER THE OFFSHORE
WATERS (IF THAT)...AS DRIER AIR DOES GET INTO THE NEARSHORE
WATERS. COULD NOT RULE OUT A ROGUE SHOWER NEAR MATAGORDA ISLAND
BUT THAT WILL BE VERY BRIEF AND UNLIKELY TO HAPPEN (SO NOT IN
FORECAST).
&&
.FIRE WEATHER (TODAY THROUGH TUESDAY)...FIRE WEATHER PROCEDURE IS
SHOWING ELEVATED CONDITIONS/ISOLATED CRITICAL OVER MUCH OF THE AREA
ON TUESDAY. FUEL DRYNESS FORECAST MAP IS SHOWING MOST AREAS IN
NORMAL MOISTURE..WITH ONLY A PART OF THE NORTHERN COASTAL BEND (LIVE
OAK AND PORTIONS OF BEE AND MCMULLEN COUNTIES) IN DRY FUELS. SINCE
THESE COUNTIES ARE FORECAST TO BE IN ELEVATED CONDITIONS ON
TUESDAY...NO NEED FOR FIRE WEATHER WATCH OR RED FLAG WARNING. DAY
SHIFT OR NEXT MID SHIFT CAN RE-EVALUATE...ESPECIALLY IF FUEL DRYNESS
MAP CHANGES THE NEXT DAY.
&&
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...PERIOD BEGINS WITH
COOLER TEMPERATURES AND DRY CONDITION IN WAKE OF TUESDAY/S/S FROPA.
BROAD LONGWAVE TROUGH CENTERED OVER THE FAR NORTH CENTRAL STATES
WILL KEEP FAIRLY ZONAL FLOW OVER SOUTH TEXAS THROUGH THURSDAY.
TROUGH WILL FINALLY SWING OVER THE REGION THURSDAY NIGHT INTO
FRIDAY. ECMWF CONTINUES TO BE THE WETTER SOLUTION WITH THIS PASSING
WHILE THE GFS/NAM STAY MOSTLY DRY OVERLAND. WHILE THERE IS THE UPPER
LEVEL SUPPORT FOR PERHAPS SOME SPRINKLES AND RAIN TO DEVELOP THERE IS
AN OVERALL LACK OF SUFFICIENT MOISTURE OVER MOST OF THE REGION
EXCEPT IN THE OVER THE OFFSHORE WATERS THURSDAY NIGHT INTO FRIDAY
MORNING. KEPT THE 20 POPS MENTION OVER THE OFFSHORE WATERS FOR
NOW...BUT EVEN THIS MAY BE GOING TOO HIGH. OTHERWISE EXPECT A
CONTINUED DRY FORECAST. TEMPERATURES WILL BE NICELY COOLER (BELOW
AVERAGE) THROUGH THE END OF THE WEEK BEFORE RETURNING TO NORMAL ON
BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 99 66 93 61 80 / 10 0 10 10 10
VICTORIA 93 63 88 55 81 / 10 0 10 10 10
LAREDO 104 69 98 62 86 / 0 0 10 10 10
ALICE 102 64 96 57 83 / 10 0 10 10 10
ROCKPORT 92 67 89 62 79 / 10 0 10 10 10
COTULLA 98 63 92 54 83 / 0 0 0 10 10
KINGSVILLE 102 65 97 60 81 / 10 0 10 10 10
NAVY CORPUS 90 67 87 65 79 / 10 0 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT
O`CONNOR.
SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM.
&&
$$
GW/86...SHORT TERM
LK/84...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1226 AM CDT MON APR 28 2014
.DISCUSSION...SEE 06Z AVIATION DISCUSSION AND MARINE
DISCUSSION...AS EXTENDED THE SCA FOR ANOTHER FEW HOURS.
&&
.AVIATION...IFR CIGS WILL CONTINUE OR DEVELOP AT KCRP AND
KVCT...AND MAY EVEN GET INTO KALI BEFORE SUNRISE. VSBYS SHOULD BE
MVFR FOR THE MOST PART...BUT COULD SEE SOME TEMPO IFR AT KVCT AND
KALI. SURFACE TROUGH APPROACHES THIS MORNING...BRINGING NORTHWEST
WINDS AND SHOULD RAPIDLY LIFT IFR CONDITIONS BY 15Z. CONDITIONS
SHOULD REMAIN VFR FOR THE REST OF THE PERIOD...EXCEPT MAYBE SOME
LIGHT FOG AT KVCT ONCE THE WINDS DIE DOWN. GENERALLY N-NW WINDS BY
15Z DIMINISHING IN THE AFTERNOON...THEN LIGHT SOUTHERLY AFTER
SUNSET AS SEA-BREEZE DIMINISHES.
&&
.MARINE...WINDS NEAR THE COAST ARE STILL GOING PRETTY
STRONG...WITH KNGP GUSTING TO OVER 30 KNOTS. BASED ON HRRR AND
LOWER RESOLUTION MODEL DATA...HAVE EXTENDED THE SCA FOR THE BAYS
AND FOR THE NEARSHORE WATERS ANOTHER 1-2 HOURS. WILL KEEP MENTION
OF CONVECTION IN FOR NOW...BUT MAY PULL IT OUT IN THE MORNING
PACKAGE IF DRIER MODEL TRENDS CONTINUE. UPDATED MWW AND CWF OUT.
&&
.PREV DISCUSSION... /ISSUED 710 PM CDT SUN APR 27 2014/
DISCUSSION...UPDATED FOR 00Z AVIATION.
AVIATION...DRYLINE HAS RETREATED THIS EVENING WITH E TO ESE WINDS
RETURNING TO ALI/CRP. VFR CONDITIONS WILL PERSIST THROUGH AT LEAST
06Z...BUT MVFR/IFR CONDITIONS MAY DEVELOP AT ALI/VCT LATE TONIGHT
WITH LOW CLOUDS AND FOG/BR...AND MVFR CONDITIONS AT CRP DUE TO BR.
CONDITIONS WILL IMPROVE BY 14Z ON MONDAY WITH VFR CONDITIONS
THROUGH THE REMAINDER OF THE DAY.
PREV DISCUSSION... /ISSUED 413 PM CDT SUN APR 27 2014/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...CONCUR WITH THE
GFS/NAM THAT AN UPPER LOW WILL MEANDER OVER THE PLAINS DRG THE
PERIOD WITH EMBEDDED DISTURBANCES/SHORTWAVES MOVG WWD ACRS SOUTH
CENTRAL TX AND AN UPPER JET ACRS NRN/CNTRL TX. THUS MUCH OF THE
DYNAMICS WILL REMAIN NORTH OF THE CWA/MSA. ANTICIPATE THE
DEVELOPMENT OF RADIATIONAL FOG EARLY MONDAY OVER THE ERN CWA PER
NAM SOUNDINGS/SREF OUTPUT. SUFFICIENT MSTR PER NAM PWAT AND
LIMITED DYNAMICS MAY RESULT IN ISOLD CONVECTION NEAR THE COAST
EARLY MONDAY BEFORE SIGNIFICANT DRYING OCCURS. THE DRY LINE IS
EXPECTED TO MOVE ACRS THE CWA AGAIN RESULTING IN HOT CONDITIONS
MONDAY AFTN AT LEAST OVER THE CNTRL/WRN SECTIONS.
MARINE...EXPECT SCA CONDITIONS TO PERSIST OVER THE COASTAL WATERS
OVERNIGHT PER NAM DETERMINISTIC/UPPER JET DYNAMICS TO THE NW.
ANTICIPATE THAT SCA CONDITIONS OVER THE SRN BAYS WL CONTINUE AT
LEAST UNTIL 03Z MONDAY YET CONFIDENCE NOT TOO GREAT. PATCHY SEA
FOG EXPECTED OVER THE BAYS/COASTAL WATERS TONIGHT WHEN CONSIDERING
SFC DEW POINTS/SST VALUES/WIND. LIKELIHOOD FOR SEA FOG DECREASES
AFTER 12Z MONDAY OWING TO FCST WIND PATTERN. PATCHY SEA FOG
EXPECTED TO DEVELOP AGAIN OVER THE COASTAL WATERS DRG THE 00-09Z
TUESDAY PERIOD BEFORE WIND BECOMES UNFAVORABLE AGAIN.
LONG TERM (TUESDAY THROUGH SUNDAY)...FRONTAL BOUNDARY WILL MOVE
THROUGH THE CWA SOMETIME BETWEEN 12Z AND 18Z ON TUESDAY. GFS NAM AND
SREF OUTPUT ALL GENERALLY AGREEING ON AN EARLIER FRONTAL PASSAGE
AROUND 12Z...WITH ECM FAVORING A PASSAGE CLOSER TO 18Z. WITH THE
COOLER AIRMASS MOVING IN BEHIND THE FRONT...THIS MAKES FOR A RATHER
UNCERTAIN HIGH TEMPERATURE FORECAST SINCE ITS HARD TO GAUGE HOW MUCH
TEMPERATURES ARE GOING TO WARM UP IN ADVANCE OF THE FRONT.
REGARDLESS...THERE IS NOT MUCH OF A CHANCE FOR PRECIPITATION DUE TO
INSUFFICIENT MOISTURE. DECIDED TO GO COOLER RATHER THAN WARMER DUE
TO MORE NWP MODELS CALLING FOR THE EARLIER PASSAGE. HIGH PRESSURE
SURFACE RIDGE SETTLES IN BEHIND THE FRONT AND DOESNT REALLY GO
ANYWHERE UNTIL SATURDAY. ADDITIONALLY...PERSISTENT MID LEVEL
GENERALLY WESTERLY FLOW ALOFT WILL PREVAIL DURING THIS TIME ON THE
SOUTH SIDE OF A LARGE AND SLOW MOVING CLOSED UPPER LEVEL LOW
CENTERED OVER THE MIDWEST. WINDS AT THE SURFACE WILL REMAIN NE ON
WED AND THEN BECOME MORE EASTERLY ON THURSDAY AND FRIDAY. MAY SEE
SOME SCEC/SCA CONDITIONS OFFSHORE WEDNESDAY AND THURSDAY AS THE
PRESSURE GRADIENT TIGHTENS IN RESPONSE TO A SURFACE TROUGH LOCATED
OVER THE YUCATAN. THURSDAY AND FRIDAY WILL SEE MORE MID LEVEL
MOISTURE AND THUS MORE CLOUD COVER...KEEPING TEMPERATURES COOLER. A
STRONG SHORTWAVE DISTURBANCE IS FORECAST TO MOVE OVERHEAD
FRIDAY...BUT THE BEST MOISTURE AVAILABILITY SHOULD BE TOO FAR SOUTH
FOR ANY DECENT POPS. HAVE STILL INCLUDED 20 POPS OVER THE OFFSHORE
WATERS AS MOISTURE CONTENT LOOKS AS IF IT WILL BE SLIGHTLY HIGHER
THERE. OVER THE WEEKEND...SURFACE HIGH PRESSURE FINALLY SHIFTS
OFFSHORE...WITH MODERATE TO STRONG SOUTHEASTERLY FLOW RETURNING AS A
RESULT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 66 85 60 84 60 / 10 10 10 10 10
VICTORIA 64 82 54 81 53 / 10 10 10 10 10
LAREDO 68 89 60 86 60 / 10 10 10 10 10
ALICE 64 86 57 84 56 / 10 10 10 10 10
ROCKPORT 68 84 63 83 61 / 10 10 10 10 10
COTULLA 62 86 55 84 55 / 0 0 10 10 10
KINGSVILLE 65 88 58 83 58 / 10 10 10 10 10
NAVY CORPUS 69 83 64 80 64 / 10 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 2 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT
O`CONNOR.
SMALL CRAFT ADVISORY UNTIL 5 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1148 PM CDT SUN APR 27 2014
.UPDATE...
FORECAST IS ON TRACK. POPS OF 20-30 PERCENT OVER THE EAST SHOULD
COVER ISOLATED TO SCATTERED NATURE OF SEVERE CONVECTION...BUT DID
EXTEND DURATION FROM 6Z TO 9Z. UPDATED TEXT PRODUCTS TO INCLUDE
MENTION OF NEW TORNADO WATCH. WHILE LARGE HAIL IS THE MAIN
THREAT...ANY SUPERCELL STORMS WILL HAVE THE ABILITY TO OVERCOME
LOW LEVEL INHIBITION AND ACCESS NEAR SURFACE AIR PARCELS WHICH
WILL INCREASE THE RISK FOR ROTATION AND TORNADOGENESIS. THIS IS
MOST LIKELY PARTICULARLY ACROSS THE SOUTHEAST ZONES WHERE CIN IS
LOWEST. TR.92
&&
.AVIATION...
ALL CURRENT CONVECTION FIRING EAST OF TAF SITES AND WILL CONTINUE
TO MOVE EAST AWAY FROM THE TRACON. OTHERWISE...VFR FORECAST WITH
NO CONCERNS. MID-HIGH CLOUDS WILL BE IN PLACE OVERNIGHT...BUT
SHOULD SCATTER OUT TOMORROW...ONLY TO ARRIVE AGAIN MONDAY EVENING.
LIGHT SOUTHWEST WINDS TONIGHT WILL BECOME NORTHWEST BEHIND A WEAK
FRONT BY SUNRISE. WITH DEEP MIXING...WINDS SHOULD TURN TO A MORE
WESTERLY DIRECTION AT SPEEDS NEAR 15KT TOMORROW AFTERNOON. SPEEDS
LIKELY NOT HIGH ENOUGH TO CAUSE MAJOR ISSUES WITH N-S RUNWAYS.
TR.92
&&
.UPDATE...
LATEST MESO-ANALYSIS INDICATED A STATIONARY DRY LINE FROM BONHAM
TO MESQUITE TO NEAR CAMERON. MEANWHILE A PACIFIC COLD FRONT WAS
JUST A FEW MILES TO ITS WEST...ALONG A LINE SHERMAN TO FORT WORTH
TO LAMPASAS. WINDS BEHIND THE FRONT WERE STRONGER AND FROM THE
WEST BUT RAPID BOUNDARY LAYER DECOUPLING SHOULD OCCUR IN THE NEXT
HOUR WITH WINDS DROPPING BELOW WIND ADVISORY CRITERIA. EXPIRED
WIND ADVISORY ON TIME AT 7 PM.
MORE CONCERNING WITH THE FORECAST IS THE CONVECTIVE POTENTIAL THIS
EVENING. WITH THE SUN SETTING...THE THREAT FOR INITIATION OF
SURFACE BASED CONVECTION ALONG THE DRY LINE WILL WANE DUE TO
INCREASING CIN AND THE SEVERE WATCH WILL LIKELY EXPIRE AT 8PM.
THE DRY LINE WILL MOVE BACK TO THE WEST AFTER SUNSET AS IS OFTEN
THE CASE...LIKELY MEETING OR PERHAPS ALSO PUSHING THE PACIFIC
FRONT BACKWARD. THE FRONT IS AWAITING A PUSH FROM A STRONG
SHORTWAVE THAT WILL ARRIVE LATER THIS EVENING...WITH STRONG UPWARD
FORCING BEGINNING TO SPREAD ACROSS THE REGION AFTER 10 PM. WHILE
SURFACE BASED CONVECTION FIRING ALONG A WESTWARD RETREATING DRY
LINE DURING THE EVENING IS RARE DUE TO INCREASED CIN...IT DOES
HAPPEN OCCASIONALLY.
INSTEAD WHAT IS LIKELY TO HAPPEN IS THAT UPWARD FORCING OCCURRING
IN THE PRESENCE OF NEARLY DRY ADIABATIC LAPSE RATES UP TO 14000
FEET WILL SQUEEZE OUT WHATEVER MOISTURE IT CAN FIND FOR ELEVATED
HIGH BASED CONVECTION. MODEL SOUNDINGS FROM THE RAP ARE MOST
AGGRESSIVE WITH THIS SCENARIO...AND SUGGEST ISOLATED TO SCATTERED
ELEVATED THUNDERSTORMS DEVELOPING ALONG THE I-35 CORRIDOR AND
GATHERING STRENGTH AS THEY HEAD INTO THE DEEPER MOISTURE ACROSS
THE EASTERN ZONES. OBVIOUSLY ANY STORMS IN THIS ENVIRONMENT WILL
HAVE A LARGE HAIL THREAT. WHILE THIS IS A POSSIBLE SCENARIO...IT
IS UNCERTAIN RIGHT NOW HOW LIKELY IT IS. THEREFORE WE WILL KEEP
POPS AT 20-30 PERCENT THROUGH 1 AM OVER AREAS JUST EAST OF I-35
AND CONTINUE TO WATCH TRENDS IN SATELLITE AND RADAR DATA FOR
ADDITIONAL DEVELOPMENT LATER THIS EVENING.
TR.92
&&
.PREV DISCUSSION... /ISSUED 319 PM CDT SUN APR 27 2014/
DRYLINE/SURFACE TROUGH CONTINUES MOVING EAST AND CURRENTLY
EXTENDED FROM NEAR BONHAM...TO DALLAS...TEMPLE AND WAS MOVING
SLOWLY EAST. ONE ISOLATED STRONG STORM WAS UP NEAR BONHAM WITH
ANOTHER POTENTIALLY DEVELOPING CELL OVER EASTERN COLLIN CO...
OTHERWISE IT REMAINED QUIET. DESPITE SURFACE DEW POINTS BETWEEN
65-70 DEGREES...WARM TEMPERATURES...INSTABILITY ABOVE 2000 J/K AND
GOOD SHEAR...LOW LEVEL CONVERGENCE ACROSS OUR CENTRAL TEXAS
COUNTIES WAS NOT AS GOOD DUE TO SLIGHTLY VEERED FLOW AHEAD OF THE
DRYLINE. THIS MAY CHANGE AS A 300MB SPEED MAX CONTINUES ROTATING
NORTHEAST THROUGH 00Z AND HELPS TRIGGER ISOLATED STORMS...POSSIBLY
MORE SCATTERED IN THE FAR E/NE FROM CORSICANA/ATHENS NORTHWARD.
QUICK CHAT WITH SPC WAS THAT CURRENT SEVERE THUNDERSTORM WATCH 94
WOULD BE ALLOWED TO EXPIRE AT 3 PM AND REPLACED BY SEVERE
THUNDERSTORM WATCH 99 FOR OUR FAR EAST CENTRAL AND NORTHEAST
COUNTIES THROUGH 8 PM. SEVERE STORMS ARE ALREADY DEVELOPING
RAPIDLY AND BECOMING SEVERE BETWEEN BONHAM AND PARIS WITH OTHER
SIGNS OF DEVELOPMENT SOUTHWEST TOWARD ROCKWALL AND TERRELL. LOOK
FOR A 10-30 PERCENT COVERAGE OF POSSIBLE STRONG TO SEVERE STORMS
ACROSS THE EASTERN THIRD OF NORTH TEXAS INTO EARLY EVENING WITH
HAIL AND DAMAGING WINDS THE MAIN THREATS DUE TO THE AFOREMENTIONED
SLIGHTLY VEERED FLOW AHEAD OF THE DRYLINE.
BEHIND THE DRYLINE...GUSTY WEST-SOUTHWEST WINDS 20 TO 30 MPH WITH
GUST 35 TO 40 MPH ARE EXPECTED AND MAY RESULT IN SOME BLOWING DUST
FROM THE DFW METROPLEX NORTH AND WEST THROUGH MID EVENING. BEYOND MID
EVENING...WE EXPECT THE DRYLINE TO REACH OUR EASTERN EDGE AND RISK
FOR SEVERE STORMS MOVING INTO EAST TEXAS...THE ARKLATEX AND MID MS
VALLEY. DRIER AIR TONIGHT COMBINED WITH DIMINISHING WEST WINDS
SHOULD ALLOW FOR A COOL AND PLEASANT NIGHT...BEFORE ANOTHER WINDY...
DRY AND VERY WARM DAY ENSUES MONDAY WITH FIRE WEATHER CONCERNS AND
POSSIBLY ANOTHER WIND ADVISORY NEEDING TO BE ISSUED. WEST-
SOUTHWEST WINDS 15-25 MPH AND GUSTY ARE EXPECTED OR POSSIBLY
SLIGHTLY HIGHER BY MONDAY AFTERNOON.
THE FIRST OF SEVERAL COLD FRONTAL SURGES IS EXPECTED TO ARRIVE
MONDAY NIGHT INTO TUESDAY MORNING. MEANWHILE...ANOTHER STRONG
CYCLONICALLY CURVED SHORTWAVE WILL ROTATE ACROSS THE RED RIVER
WITH MOST MOISTURE ANCHORED ABOVE 700MB. ONLY MENTIONED ISOLATED
HIGH-BASED OR ELEVATED SHOWERS FOR THIS PERIOD...THOUGH EVENTUALLY
THUNDER MAY NEED TO BE INTRODUCED IF LAPSE RATES REMAIN HIGH. THE
LOW LEVELS WILL REMAIN VERY DRY...SO LITTLE MEASURABLE RAINFALL
WOULD OCCUR WITH THE FRONTAL PASSAGE. MAY WELL BE JUST SOME VIRGA
WOULD COULD POSSIBLY TRANSLATE SOME GUSTIER NORTHWEST WINDS DOWN
THE SURFACE BY TUESDAY MORNING.
AFTERWARD...A DRY AND SEASONABLY COOL PERIOD IS EXPECTED WITH THE
DRY CONTINENTAL AIRMASS BEING SUPPORTED BY STALLING AND OCCLUDING
UPPER LOW PIN-BALLING OVER THE MID MISSISSIPPI VALLEY AND MIDWEST.
AS NOTED IN PREVIOUS DISCUSSIONS...THE REASON FOR THE UPPER LEVEL
LOW REMAINING STATIONARY IS A BLOCKING UPPER HIGH OVER EASTERN
CANADA. THE AIRMASS WILL BE UNUSUALLY DRY FOR HEADING INTO EARLY
MAY AND ALLOW FOR A LARGE DIURNAL RANGE ON LOWS AND HIGHS WITH
45-50 FOR LOWS AND HIGHS 70-75...EXCEPT SLIGHTLY WARMER OVER
CENTRAL TEXAS. FLOW ALOFT OVER NORTH TEXAS DAMPENS BY NEXT WEEKEND
AS THE EASTERN CANADIAN RIDGE FINALLY WEAKENS AND ALLOW THE
OCCLUDED UPPER LOW TO BE OPENED UP AND CARRIED QUICKLY EAST.
SOUTHERLY LOW LEVEL FLOW THEN RETURNS AND HIGHS REBOUND BACK INTO
THE 80S.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 58 84 52 75 50 / 5 5 10 10 5
WACO, TX 56 87 51 80 47 / 10 5 5 5 5
PARIS, TX 57 79 51 72 46 / 30 5 10 10 5
DENTON, TX 52 84 48 74 45 / 5 5 10 5 5
MCKINNEY, TX 53 84 49 73 46 / 20 5 10 10 5
DALLAS, TX 62 86 54 75 51 / 10 5 10 10 5
TERRELL, TX 57 83 52 75 47 / 30 5 10 10 5
CORSICANA, TX 58 86 55 78 48 / 30 5 5 10 5
TEMPLE, TX 59 88 55 79 48 / 20 5 5 5 5
MINERAL WELLS, TX 52 87 49 76 47 / 5 5 10 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1142 PM CDT SUN APR 27 2014
.DISCUSSION...
06Z TAF DISCUSSION IN AVIATION SECTION.
&&
.AVIATION...
DRYLINE/PAC FRONT LOOKS TO BE MAKING SOME PROGRESS THROUGH C TX
TONIGHT. HRRR AND EVEN NAM HINTING AT POSSIBILITY OF CONVECTION
DURING THE MORNING HOURS AS BOUNDARY MOVES SOUTH. BASED OFF
EVENING SOUNDING DATA THINK CAP MAY BE TOO STRONG FOR CONVECTION
BUT WORTH NOTING. WILL LEAVE OUT MENTION OF TSRA IN TAFS FOR NOW.
CONVECTION ALONG BOUNDARY MAY SUGGEST THESE MODELS ARE ON THE
RIGHT TRACK. OTHERWISE EXPECT IFR/MVFR CIGS UNTIL BOUNDARY PUSHES
SOUTH WITH DRIER AIR BEHIND IT. HAVE CLEAR SKIES FOR TOMORROW
AFTERNOON. BOUNDARY MAY PUSH BACK NORTH WITH MOISTURE SOUTH OF THE
FRONT. COULD GET LOW CLOUD DECKS AGAIN.
39
&&
.PREV DISCUSSION... /ISSUED 1120 PM CDT SUN APR 27 2014/
UPDATE...
UPDATED THE FORECAST FOR TORNADO WATCH 105 ISSUED UNTIL 5 AM THAT
INCLUDES HOUSTON AND TRINITY COUNTIES. ADDED ISOLATED SEVERE
THUNDERSTORMS FOR BOTH COUNTIES.
40
PREV DISCUSSION... /ISSUED 940 PM CDT SUN APR 27 2014/
DISCUSSION...
ISOLATED STRONG TO SEVERE THUNDERSTORMS THAT OCCURRED ALONG
HIGHWAY 290 IN WESTERN AND CENTRAL WASHINGTON COUNTY HAVE
WEAKENED. AS THE DRY LINE MOVES INTO SE TX...ISOLATED SHOWERS OR
THUNDERSTORMS MAY DEVELOP LATER TONIGHT. AFTER LOOKING AT THE
SHORT RANGE MODELS...IT APPEARS THAT THE BEST LOCATIONS ARE
GENERALLY ALONG AND NORTH OF A LINE FROM BRENHAM TO CLEVELAND.
THE 00Z RUN OF THE NAM12 WEAKENS THE LOW-LEVEL JET OVERHEAD OF THE
AREA LATER THIS EVENING. WITH THIS IN MIND...TOOK OUT THE MENTION
OF DRIZZLE FOR THE REMAINDER OF THE NIGHT.
40
PREV DISCUSSION... /ISSUED 752 PM CDT SUN APR 27 2014/
UPDATE...
UPDATE FOR ISOLATED THUNDERSTORMS MOVING TOWARD BURLESON AND
WASHINGTON COUNTIES FROM THE WEST.
40
DISCUSSION...
DRY LINE/COLD FRONT APPROACHING FROM THE WEST. ISOLATED
THUNDERSTORMS HAVE DEVELOPED AHEAD OF THE DRY LINE IN BASTROP AND
LEE COUNTIES AND WERE MOVING INTO BURLESON AND WASHINGTON
COUNTIES. LARGE HAIL HAS BEEN REPORTED...BUT THE STORM MOVING
THROUGH BURLESON COUNTY WEAKENED BEFORE MOVING INTO THE COUNTY.
THE 00Z CRP SOUNDING HAD A SURFACE BASED CAPE OF ALMOST 4700...
ALTHOUGH THERE WAS A DECENT CAP IN PLACE. ISOLATED STRONG TO
SEVERE STORMS ARE POSSIBLE THROUGH MID EVENING AS THE STORMS THAT
DO DEVELOP MOVE OFF THE DRYLINE...ESPECIALLY ALONG AND NORTH OF A
LINE FROM BRENHAM TO HUNTSVILLE. DO EXPECT THE STORMS TO BEGIN
LOSING INTENSITY DURING THE LATE EVENING DUE TO THE LOSS OF
DAYTIME HEATING.
40
PREV DISCUSSION... /ISSUED 641 PM CDT SUN APR 27 2014/
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
SFC ANALYSIS HAS DRYLINE ALONG THE I-35 CORRIDOR WITH A FEW ISO
STORMS WEST OF KAUS. CAP EAST OF THESE STORMS PROBABLY STRONG
ENOUGH THAT THE STORMS SHOULD WEAKEN BEFORE REACHING KCLL SO WILL
CONTINUE TO MONITOR. LEFT TAF VOID OF CONVECTION AS PROBABILITIES
SMALL AT THIS POINT.
MAIN CONCERN WILL BE LOW MVFR CIGS AHEAD OF WEAK PACIFIC FRONT.
DRIER AIR SHOULD MIX INTO THE AREA BY THE MORNING HOURS AND HELP
SCT OUT CIGS 12-15Z WITH MAINLY CLEAR SKIES AFTER THAT. WINDS
SHOULD TURN TO THE WSW/WNW DIRECTIONS AROUND 10KTS. BOUNDARY
SHOULD WORK BACK NORTH MONDAY NIGHT WITH STRONGER PACIFIC FRONT ON
TUESDAY.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 65 91 62 82 51 / 20 10 10 10 10
HOUSTON (IAH) 72 91 68 86 55 / 20 20 10 10 10
GALVESTON (GLS) 73 82 72 82 62 / 20 10 10 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 AM CDT MONDAY FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 7 AM CDT MONDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
402 AM EDT MON APR 28 2014
.SYNOPSIS...
A WEAK STATIONARY FRONT WILL REMAIN JUST SOUTH AND WEST OF THE
REGION TODAY INTO TUESDAY. A LARGE AND COMPLEX STORM SYSTEM
LOCATED OVER THE CENTRAL UNITED STATES WILL SLOWLY MOVE EAST. THIS
SYSTEM WILL PROVIDE RAINFALL FOR MUCH OF THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 AM EDT MONDAY...
WEAK BACKDOOR TYPE COLD FRONT NOW HEADING INTO THE SW PORTIONS OF
THE CWA WITH A STIFF EASTERLY FLOW DEVELOPING ESPCLY EAST OF THE
BLUE RIDGE WHERE BEST COOL ADVECTION WILL TAKE SHAPE THIS MORNING.
INIT MID LEVEL WAVE EJECTING OUT INTO THE SHORTWAVE RIDGING ALOFT
LIKELY TO HELP MOISTEN THE COLUMN EARLY ON WITH MAINLY JUST SPOTTY
-RA OR SPRINKLES INTO MID MORNING PER LATEST RADAR TRENDS. MAIN
SHOT AT MORE WIDESPREAD RAINFALL LOOKS TO COME FROM LATE MORNING
INTO MID AFTERNOON AS ANOTHER WAVE SLIDES BY TO THE NW AND HELPS
UPWARD MOTION SWING ACROSS THE NORTH UNDER A CORE OF SLIGHTLY
HIGHER 85H WINDS. MOST GUIDANCE ON TRACK WITH THIS FEATURE WITH
THE LATEST HRRR EXPANDING THIS AXIS EAST TO ALONG THE BLUE RIDGE
AROUND MIDDAY BEFORE TAKING IT TO THE EAST DURING THE AFTERNOON
ALONG THE GRADIENT OF THE THETA-E AXIS ALOFT. THUS HAVE INCLUDED
SOME CHANCE POPS MAINLY WEST EARLY THIS MORNING...THEN A PERIOD OF
LIKELYS FROM WEST TO EAST THROUGH LATE AFTERNOON WHEN SEE BEST
OVERRUNNING. HOWEVER QPF DOESNT LOOK TOO IMPRESSIVE WITH THIS
FEATURE WITH A TENTH TO A QUARTER INCH POSSIBLE WITH ANY THUNDER
FAR WEST AWAY FROM THE DEVELOPING EASTERN WEDGE. HIGH TEMPS REMAIN
TRICKY AS COULD SEE AREAS ACROSS THE NE ONLY RISE A FEW DEGREES
WHILE JUMPING ABOVE 70 ALONG THE I-77 CORRIDOR. WENT CLOSER TO THE
COLDER MET MOS ALONG/EAST OF THE BLUE RIDGE AND A BLEND OUT WEST.
IMPULSE EXITS BY THIS EVENING LEAVING MOST OF THE REGION IN A
STRONG WEDGE WITH ABSENCE OF MUCH LIFT WITH A BAND OF DEEPER
CONVECTION APPROACHING THE MOUNTAINS FROM THE WEST LATE. HOWEVER
SOUNDINGS SHOW A RATHER DEEP EAST/SE LOW LEVEL FLOW UNDER VEERING
ALOFT WHICH WOULD SUPPORT AT LEAST SPOTTY -RA/DZ OUTSIDE THE FAR
WEST WITH ADDED UPSLOPE LIKELY ENHANCING COVERAGE EASTERN SLOPES
OF THE BLUE RIDGE. WEAKENING SHRA/TSRA HEADED IN FROM THE WEST
AROUND DAYBREAK COULD REACH THE WESTERN SLOPES SO KEPT IN SOME
THUNDER MENTION ON THE PERIMETER OF THE WEDGE FOR NOW OVERNIGHT.
OTRW CLOUDY AND DAMP WITH PERIODS OF -RA/DZ AND PERHAPS A FEW MORE
-SHRA SW AS DEEPER WARM ADVECTION SPREADS NORTH ALOFT LATE. KEPT
LOWS CLOSER TO THE COOLER MET MOS AGAIN IN EXPECTING A STRONGER
WEDGE IN THE WAKE OF EARLIER RAINFALL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT MONDAY...
DEEP UPPER CLOSED LOW OVER IOWA AND THE UPPER RIDGE ALONG THE EAST
COAST WILL MOVE EAST DURING THE PERIOD. THE MAIN LOW MOVES EAST
ACROSS THE GREAT LAKES WHILE A WAVE OF LOW PRESSURE ALONG THE
FRONTAL BOUNDARY WILL TRACK TOWARD THE MISSISSIPPI RIVER BY TUESDAY
EVENING.
PLENTY OF MOISTURE IS TRANSPORTED INTO THE REGION FROM THE ATLANTIC
OCEAN AT LOWEST LEVELS AND FROM THE GULF OF MEXICO THROUGH A DEEP
LAYER FARTHER ALOFT. HIGH TEMPERATURES ON TUESDAY ARE TRICKY
DEPENDING SUNSHINE AND AMOUNT OF RAIN. PLAYED HIGHS TOWARDS THE
COOLER ADJMET WITH VALUES FROM THE UPPER 50S ACROSS THE NORTH TO THE
LOWER 70S ACROSS THE SOUTH. THE SWODY2 HAS A FEW SOUTHEAST COUNTIES
IN THE SLIGHT RISK FOR SEVERE THUNDERSTORMS. APPEARS THAT THEY ARE
ALLOWING THE WEDGE TO WEAKEN ON THE SOUTHERN END FOR A FEW HOURS.
WITH THE STRENGHT OF THE WEDGE...GENERALLY UNDERDONE ON THE
MODELS...QUESTIONS ON WHETHER THE WEDGE MIXES OUT FOR A FEW HOURS
TUESDAY AFTERNOON.
BEST Q-V FORCING AND UPPER DIFFLUENCE IN THE RIGHT REAR QUADRANT OF
THE UPPER JET WILL BE TUESDAY NIGHT AND WEDNESDAY. PRECIPITABLE
WATER VALUES RISE TO AS HIGH AS 1.6 INCHES ACROSS THE SOUTHERN AND
EASTERN COUNTY WARNING AREA TUESDAY...WHICH IS AROUND TWO STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. KEPT THE HIGHEST QPF
IN THE TUESDAY NIGHT TO WEDNESDAY TIME FRAME...SIMILAR TO WPC
GUIDANCE. HPC HAS PLACED EXCESSIVE RAINFALL POTENTIAL FOR DAY 2-3
ALONG AND EAST OF THE BLUE RIDGE. HOWEVER WILL HOLD OFF ON A FLOOD
WATCH FOR NOW GIVEN INTERVALS OF HEAVY RAIN AND WHERE EXCESSIVE
MAY OCCUR BASED ON RAINFALL THROUGH MONDAY NIGHT. THUS WILL
MENTION FLOODING POTENTIAL IN THE HWO FOR TUESDAY INTO WEDNESDAY.
CLOUDS MAY HOLD UP LOW TEMPERATURES TUESDAY NIGHT. PLAYED OVERNIGHT
LOW TEMPERATURES FOR THE LOWER 50S IN THE NORTHERN MOUNTAINS TO THE
LOWER 60S IN THE PIEDMONT.
WEDNESDAY LOOKS MORE UNSTABLE WITH LIS AROUND MINUS 5 AND CAPES
POTENTIALLY EXCEEDING 2000 J/KG. INCREASED THE COVERAGE OF
THUNDERSTORMS WEDNESDAY. THE SWODY3 HAS MUCH OF THE CWA IN THE
SLIGHT RISK AHEAD OF THE COLD FRONT. THE MAIN THREAT WILL BE
DAMAGING WINDS. HIGH TEMPERATURES ON WEDNESDAY WILL BE WARMER THAN
TUESDAY WITH READINGS FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID
70S IN THE PIEDMONT. TAPER POPS OFF WEDNESDAY NIGHT INTO THURSDAY.
LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE THE MID 40S IN THE
MOUNTAINS TO AROUND 60 DEGREES IN THE PIEDMONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...
ON THURSDAY...THE CLOSED UPPER LOW WILL BE OVER THE GREAT LAKES
WITH THE LARGE TROF COVERING MUCH OF THE CENTRAL AND EASTERN
UNITED STATES. THE PATTERN REMAINS AMPLIFIED THROUGH SATURDAY BUT
THE REX BLOCK WEAKENS...THE LOW OPENS UP AND THE TROF GRADUALLY
MOVES EAST BY SATURDAY. A SHORT WAVE TRACKING THROUGH THE BASE OF
THE UPPER TROF WILL MOVE ACROSS THE TENNESSEE VALLEY ON SATURDAY.
A STRONGER SHORT WAVE MOVES INTO THE TROF AXIS FROM SOUTHERN
CANADA AND CLOSES OFF OVER THE UPPER MISSISSIPPI VALLEY ON SUNDAY.
ECMWF WAS SHOWING A WAVE ALONG THE SURFACE FRONT WHICH WILL
LIKELY SLOW THE PASSAGE OF THE BOUNDARY ACROSS THE AREA ON
WEDNESDAY NIGHT AND THURSDAY. THE FRONT SHOULD BE WELL OFF THE
SOUTHEAST COAST ON FRIDAY. FRIDAY NIGHT THROUGH SUNDAY HIGH
PRESSURE IS BUILDING OVER THE GULF OF MEXICO AND THE SOUTHEAST
UNITED STATES.
MODELS STILL BRING UNSEASONABLY COLD AIR INTO THE AREA BEHIND THIS
SYSTEM ON THURSDAY NIGHT AND FRIDAY. SUNDAY MORNING HAS THE
POTENTIAL TO REACH WELL INTO THE 30S FOR LOWS IN THE MOUNTAINS.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 1255 AM EDT MONDAY...
INCREASINGLY MOIST EASTERLY FLOW WILL CONTINUE OVERNIGHT INTO
MONDAY WITH THE CURRENT VFR CIGS/VSBYS DETERIORATING TOWARD MVFR
ESPCLY ALONG THE BLUE RIDGE AND POINTS EAST BY DAYBREAK. CONDITIONS
MAY IMPROVE MID- MORNING FOR SEVERAL HOURS BEFORE THE ONSET OF
LIGHT SHOWERS BY EARLY THIS MORNING AS A WEAK RIPPLE OF ENERGY
SLIDES ACROSS THE REGION PROVIDING ANOTHER BOOST TO LOW LEVEL
MOISTURE. BETTER MOISTURE ADVECTION SHOULD PRODUCE LOWER CIGS AND
INCREASING PRECIPITATION CHANCES AGAIN BY AFTERNOON WITH A LOBE OF
SHOWERS PROGGED TO MOVE EAST THROUGH THE AREA AHEAD OF ANOTHER
MID LEVEL WAVE ALOFT...WITH EVEN SOME CHANCE FOR THUNDER BUT MUCH
BETTER CHANCES TO OUR SOUTH AND WEST MONDAY AFTERNOON. LATEST
GUIDANCE SUGGESTS THAT ONCE THE INITIAL PATCHY RAINFALL EXITS AND
THE WEDGE BECOMES BETTER ENHANCED WILL SEE FLYING CONDITIONS
QUICKLY WORSEN LATER THIS AFTERNOON WITH STRATUS/FOG DEVELOPING IN
MANY LOCATIONS MAKING FOR WIDESPREAD MVFR TO IFR FOR ALL SITES
WITH LIFR POSSIBLE ESPCLY AROUND BCB/ROA TO THE EAST. THIS MAY
ACTUALLY OCCUR WITH LACK OF PRECIP THIS EVENING AS THE MAIN BATCH
OF CONVECTION AHEAD OF THE FRONT ALOFT REMAINS OFF TO THE WEST.
EXTENDED AVIATION DISCUSSION...
MUCH OF THE UPCOMING WEEK WILL BE DOMINATED BY CLOUD COVER AS
A DEEP AREA OF LOW PRESSURE ALOFT SLOWLY DRIFTS INTO THE REGION
FROM THE WEST. ONCE THIS SYSTEM ARRIVES...IT WILL LINGER ACROSS
THE REGION FOR SEVERAL DAYS. SUB VFR CONDITIONS CAN BE EXPECTED AT
INCREASING FREQUENCY AS THE WEEK PROGRESSES WITH POTENTIAL FOR
SCATTERED SHRA/TSRA IN ADDITION TO AREAS OF LIGHT RAIN AND DRIZZLE
NEAR THE BLUE RIDGE. APPEARS ENOUGH DRYING ALOFT TO PERHAPS SEE
IMPROVEMENT TO VFR ACROSS THE EAST LATER THURSDAY INTO FRIDAY WITH
MVFR LIKELY LINGERING AT TIMES ACROSS THE SE WEST VA LOCATIONS
INTO FRIDAY.
&&
.HYDROLOGY...
AS OF 300 PM EDT SUNDAY...
THERE IS A CHANCE FOR MAINSTEM RIVER FLOODING BY MID TO LATE THIS
WEEK. BUT STILL FAR TOO EARLY FOR HIGH CONFIDENCE IN WHICH RIVERS
AND HOW WIDESPREAD FLOODING WILL BE. STAY TUNED.
PATTERN SETTING UP WITH SOME IMPRESSIVE STRONG SIGNALS FOR A
PROLONGED PERIOD OF RAINFALL WITH HEAVY RAIN AMOUNTS BECOMING MORE
LIKELY...ESPECIALLY TUESDAY AFTERNOON INTO WEDNESDAY.
LATEST RUNS OF ENSEMBLE MODEL FORECAST FROM THE GEFS AND THE NAEFS
WERE SUGGESTING AN INCREASING PROBABILITY OF MODERATE RIVER FLOODING
ON THE DAN RIVER AT SOUTH BOSTON AND ON THE ROANOKE AT RANDOLPH.
FLOODING POSSIBILITIES ARE ALSO INDICATED FOR PARTS OF THE JAMES
AND GREENBRIER RIVER BASINS.
FLASH FLOODING APPEARS TO BE LESS OF A LIKELIHOOD AT LEAST AT THE
ONSET AS MUCH OF THE RAINFALL WILL BE OF THE STRATIFORM VARIETY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/PC/WP
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...KK
AVIATION...JH/KM/PC/PM
HYDROLOGY...AMS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1110 PM CDT SUN APR 27 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 313 PM CDT SUN APR 27 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED TROUGHING ALONG THE BRITISH COLUMBIA COAST...A POTENT
NEGATIVELY TILTED TROUGH AND UPPER LOW OVER KANSAS...AND A STRONG
UPPER LEVEL RIDGE FROM THE SOUTHEASTERN U.S. INTO MANITOBA. IN-
BETWEEN THE UPPER LOW AND RIDGE...PROFILER AND VWP DATA SHOWED A 30-
50 KT JET CORE AT 850MB FROM THE WESTERN GULF OF MEXICO NORTHWARD
THROUGH MINNESOTA RAPIDLY TRANSPORTING MOISTURE NORTHWARD. GOES
PRECIPITABLE WATER IMAGERY DEPICTED VALUES OF 1-1.5 INCHES
ENCOMPASSING MUCH OF IOWA SOUTHWARD INTO LOUISIANA...WITH LOWER
VALUES OF LESS THAN 0.5 INCH OVER MUCH OF KANSAS INTO WESTERN
OKLAHOMA WHERE A DRY SLOT EXISTS. ALONG AND JUST EAST/NORTHEAST OF
THIS GRADIENT OF PRECIPITABLE WATER...NUMEROUS SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED FROM CENTRAL IOWA AND MISSOURI. SOME OF
THESE STORMS ARE INTENSE TOO...MOSTLY SOUTH OF I-80 WHERE 750-1500
J/KG OF MLCAPE EXISTS PER RAP ANALYSIS. FARTHER NORTHEAST... SHOWERS
AND EMBEDDED THUNDERSTORMS THAT AFFECTED THE FORECAST AREA THIS
MORNING HAVE MOSTLY LIFTED NORTH OF I-90. THESE ARE ASSOCIATED WITH
MID-LEVEL FRONTOGENESIS AND RIGHT ENTRANCE REGION OF AN UPPER JET
OVER LAKE SUPERIOR. LASTLY...A TIGHT PRESSURE GRADIENT IN PLACE
COMBINED WITH THAT AFOREMENTIONED STRONG 850MB JET CORE HAS LED TO
BRISK EAST WINDS. THESE HAVE BEEN SUSTAINED AT 15-35 MPH WITH GUSTS
OF 25-45 MPH...STRONGEST WEST OF THE MS RIVER.
VERY GOOD MODEL AGREEMENT CONTINUES THAT THE BAND OF SHOWERS AND
THUNDERSTORMS TO OUR SOUTHWEST WILL LIFT NORTHEAST THROUGH THE
FORECAST AREA TONIGHT INTO MONDAY MORNING. THIS IS ALL IN RESPONSE
TOO THE UPPER LOW AND ASSOCIATED SHORTWAVE TROUGH LIFTING INTO
NEBRASKA AND IOWA BY 18Z MONDAY. THE QUESTION IS AMOUNT WHICH HAS
BIG IMPACTS ON POTENTIAL FOR RIVER FLOODING. THE AMOUNT HAS STRONG
TIES TO EVOLUTION OF CONVECTION OVER WESTERN MISSOURI AND SOUTHWEST
IOWA IN WHICH THERE ARE THREE SCENARIOS...
1. THE CONVECTION TURNS INTO A FORWARD PROPAGATING SQUALL
LINE...ESSENTIALLY LIMITING HEAVIER RAINFALL INTO THE FORECAST AREA.
THIS SQUALL LINE FALLS APART OVER ILLINOIS LATE THIS EVENING AS IT
RUNS INTO MORE STABLE AIR.
2. THE CONVECTION WEAKENS AS IT PUSHES EAST...RESULTING IN A
PERSISTENT WARM CONVEYOR BELT OF SHOWERS AND EMBEDDED THUNDERSTORMS.
THE TRAINING FACTOR COMES INTO PLAY...ALLOWING FOR HEAVIER
RAINFALL...ESPECIALLY ACROSS NORTHEAST IOWA THIS EVENING.
3. THE CONVECTION WEAKENS AS IT PUSHES EAST...AND ESSENTIALLY MUCH
OF THE SHOWER ACTIVITY FALLS APART BY 04Z.
ALL THREE IDEAS ARE CERTAINLY PLAUSIBLE...BUT IT IS SERIOUSLY WORTH
NOTING THE CONVECTION HAS BEEN OUTRUNNING MOST MODELS. THE ONLY
MODEL THAT HAS BEEN HANDLING THIS WELL IS THE 00Z SPC WRF-NMM...
WHICH IS SCENARIO NUMBER 3 ABOVE. THEREFORE...HAVE TRIED TO LEAN
MORE TOWARDS THAT FOR PRECIPITATION CHANCES AND QPF. STILL...THE
FORECAST MAY BE OVERDONE...ESPECIALLY WITH PRECIPITATION CHANCES IN
THAT 04-09Z TIME FRAME. WOULD THINK THAT PERSISTENT 850MB MOISTURE
TRANSPORT WOULD AT LEAST CONTINUE SOME SHOWER ACTIVITY AND NOT
COMPLETELY END...THUS THE HIGHER CHANCES IN THE FORECAST. ALL THREE
SCENARIOS ABOVE REGENERATE SHOWERS AND EMBEDDED THUNDERSTORM
ACTIVITY OVER THE FORECAST AREA AROUND 09Z...ASSOCIATED WITH DPVA
FROM THE APPROACHING NEGATIVELY TILTED SHORTWAVE TROUGH. SEE
HYDROLOGY SECTION BELOW FOR IMPACT ON RIVERS.
AFTER THE RAIN AND CONVECTION TONIGHT/MONDAY MORNING...ATTENTION
THEN TURNS TO A WARM FRONT PROGGED TO LIFT THROUGH IOWA. THE
MAJORITY OF MODELS KEEP IT JUST SOUTH OF THE FORECAST AREA...EITHER
ALONG OR SOUTH OF US-20. THE NORTHWARD PROGRESS OF THE FRONT HINGES
QUITE A BIT ON MORNING PRECIPITATION. CONVECTION LOOKS LIKELY TO
FIRE ALONG AND SOUTH OF THIS FRONTAL BOUNDARY. SOME OF THIS
CONVECTION COULD CREEP INTO FAR SOUTHERN PORTIONS OF THE FORECAST
AREA IN THE LATE AFTERNOON...AND POSSIBLY BE SEVERE. NOTE THAT A
VERY TIGHT GRADIENT OF INSTABILITY WILL EXIST...SO ANY SEVERE THREAT
SHOULD BE CONFINED TO FAYETTE EAST TO GRANT COUNTIES.
LASTLY...REGARDING THE WIND ADVISORY...AS EXPECTED THE CONDITIONS
HAVE BEEN MARGINAL. WILL KEEP IT GOING THROUGH 9 PM AS SUSTAINED
SPEEDS CONTINUE TO PULSE UP AND DOWN TO 30 MPH. THERE IS A
POSSIBILITY THE ADVISORY MAY NEED TO BE EXTENDED TO MIDNIGHT SEEING
SOME LAV GUIDANCE HOLDING RST...TOB AND OLZ BETWEEN 25-30 KT TO
06Z.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 313 PM CDT SUN APR 27 2014
THE UPPER LOW OVER NEBRASKA ON MONDAY IS THE MAIN FEATURE OF FOCUS
FOR THE LONG TERM PERIOD. MODELS CONTINUE TO SUGGEST THIS UPPER LOW
WILL PLAGUE THE FORECAST AREA THROUGH AT LEAST THURSDAY AS IT SLOWLY
TRACKS NORTHEAST INTO UPPER MICHIGAN. HEADING INTO THE WEEKEND...THE
UPPER PATTERN REMAINS COOL AS RIDGING HOLDS IN PLACE OVER THE
WESTERN U.S. INTO WESTERN CANADA...CAUSING TROUGHING TO PERSIST OVER
THE GREAT LAKES REGION. THIS IS VERY WELL AGREED UPON BY THE
27.06Z/12Z GFS AND 27.00Z/12Z ECMWF.
FOR MONDAY NIGHT INTO TUESDAY. CONDITIONS REMAIN FAVORABLE FOR A
BAND OF SHOWERS TO FORM JUST NORTH OF THAT WARM FRONTAL BOUNDARY IN
IOWA MONDAY EVENING...ASSOCIATED WITH DPVA FORCING AND 800-900MB
FRONTOGENESIS. THIS BAND...AFFECTING LOCATIONS SOUTH OF I-90 MONDAY
EVENING...SHOULD TRANSLATE NORTHWARD TO ALONG AND NORTH OF I-90 BY
TUESDAY MORNING...WITH PRECIPITATION POSSIBLY TAILING OFF TO THE
SOUTH. THEN WE GET INTO A COLD CONVEYOR BELT SCENARIO FOR TUESDAY
AFTERNOON OVER NORTHWESTERN SECTIONS OF THE FORECAST AREA. OTHER
SHOWERS SHOULD POP UP ELSEWHERE UNDER THE UPPER LOW DUE TO MID LEVEL
COLD AIR. THERE COULD EVEN BE SOME THUNDER WITH THEM...BUT
CONFIDENCE TOO LOW TO INCLUDE RIGHT NOW.
FROM TUESDAY NIGHT THROUGH THURSDAY...THE FORECAST AREA PRETTY MUCH
SITS IN A GRADUALLY WEAKENING COLD CONVEYOR BELT OF SHOWERS...WITH
PERHAPS SOME DIURNAL ENHANCEMENT THAT COULD INCREASE COVERAGE.
GIVEN HIGH CONFIDENCE OF PRECIPITATION AROUND...HAVE USED COVERAGE
VERBIAGE. WITH PLENTY OF CLOUDS AND SHOWER ACTIVITY AROUND...
COMBINED WITH 850MB TEMPS ONLY AROUND 0C PLUS OR MINUS 2
C...EXPECT CHILLY TEMPERATURES.
CHANCES OF PRECIPITATION CONTINUE OFF AND ON FOR THURSDAY NIGHT
RIGHT THROUGH SUNDAY AS SHORTWAVES DROP SOUTHEAST THROUGH THE GREAT
LAKES TROUGHING. SOME SIGNAL THAT A SHORTWAVE TROUGH ON SUNDAY
MIGHT BE MORE POTENT...SO CHANCES MAY NEED TO BE RAISED BEYOND THE
CURRENT FORECAST OF A MODEL CONSENSUS. AS IT STANDS RIGHT NOW THE
AIR IS NOT COLD ENOUGH FOR SNOW...BUT ITS NOT FAR OFF. 850MB
STANDARDIZED ANOMALIES GENERALLY HOLD AROUND 1 STANDARD DEVIATION
BELOW NORMAL...OR BETWEEN -4C AND 0C. NEEDLESS TO SAY...BELOW
NORMAL TEMPERATURES CONTINUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1110 PM CDT SUN APR 27 2014
CHALLENGING FORECAST AS THERE WILL BE PERIODS OF RA/TSRA...AND PIN
POINTING WHERE THE BREAKS IN THE PCPN WILL BE IS PROBLEMATIC. IN
ADDITION...WINDS WILL STAY STRONG AND GUSTY THROUGH TUESDAY AS TIGHT
PRESSURE GRADIENT PERSISTS FOR MUCH OF THE UPPER MISSISSIPPI RIVER
VALLEY - WITH THE RESPONSIBLE SFC LOW JUST TO THE SOUTH. WINDS WILL
ALSO REMAIN STRONG JUST OFF THE SFC...50-60 KTS AROUND 2 KFT. LLWS
WILL BE A FACTOR FOR KLSE THRU MONDAY AFTERNOON.
BRIEF BREAK IN -SHRA FOR KRST/KLSE AS ONE BAND OF PCPN SHIFTED NORTH
EARLIER THIS EVENING. ANOTHER BATCH OF SHRA/TS IS DEVELOPING ON THE
NOSE OF AN INCREASING LOW LEVEL JET ACROSS CENTRAL/EASTERN IA. A
MORE SIGNIFICANT SWATH OF THE WIDESPREAD SHRA/TS WILL RETURN NEAR
12Z MON AS AN UPPER LEVEL SHORTWAVE TROUGH SPINS NORTHEAST OUT OF
THE SOUTHERN PLAINS. SHOULD MAKE FOR A SOGGY MORNING WITH MVFR
VSBYS. ANTICIPATING CIGS IN THE IFR/MVFR RANGE BY THIS TIME.
MODEL TRENDS WOULD FAVOR LIFTING THIS NORTH OF THE TAF SITES BY 18-
20Z...BRINGING ANOTHER MOSTLY DRY PERIOD FOR THE AFTERNOON.
HOWEVER...ANOTHER ROUND OF PCPN APPEARS LIKELY AS SHRA/TS FIRE UP
ALONG A WARM FRONT JUST TO THE SOUTH LATE AFTERNOON/EVENING...WHICH
COULD PUSH NORTH.
BOTTOM-LINE...AN EXTENDED PERIOD OF WET WEATHER WITH IFR/MVFR
IMPLICATIONS FOR CIGS AND VSBYS. SOME THUNDER WILL BE POSSIBLE.
WINDS ARE GOING TO STAY STRONG...MOSTLY EAST-NORTHEAST...AND LLWS
WILL REMAIN A CONCERN AT KLSE INTO MON AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 313 PM CDT SUN APR 27 2014
PRECIPITATION FORECASTS REMAIN VERY UNCERTAIN FOR TONIGHT AS
SHOWERS AND EMBEDDED THUNDERSTORMS OVER CENTRAL IOWA ARE MOVING
FASTER THAN MOST MODELS. IN FACT...THE ONE MODEL THAT IS HANDLING
THE PRECIPITATION WELL SUGGESTS WE COULD HAVE A BREAK OF 6 HOURS
OF NO PRECIPITATION TONIGHT AFTER THEY PASS. ADDITIONALLY...THE
CONVECTION TO THE SOUTH MAY END UP INGESTING MORE OF THE
MOISTURE...LIMITING HEAVIER RAINFALL OVER THE FORECAST AREA. THIS
SCENARIO IS LOOKING MORE LIKELY FOR TONIGHT. BETTER CONFIDENCE
FOR MUCH OF THE AREA TO SEE ANYWHERE FROM 1/4 TO 1 INCH OF RAIN ON
MONDAY...WITH ANOTHER 1/2 TO 1 INCH FROM MONDAY NIGHT INTO
TUESDAY.
IN SUMMARY...BASED ON RFC FORECAST DATA...CONFIDENCE WAS ONLY HIGH
ENOUGH TO PUT A FLOOD WATCH ON THE TURKEY RIVER. SHOULD AROUND 1
INCH MATERIALIZE OVER THE BASIN THIS EVENING...THE WATCH WILL NEED
TO BE UPGRADED. ELSEWHERE...HAVE CONTINUED THE ESF. THERE ARE SOME
SIGNALS THAT HEAVIER QPF COULD FALL OVER WISCONSIN. SHOULD THIS
MATERIALIZE...MORE FLOOD WATCHES FOR AREA RIVERS MAY BE REQUIRED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MNZ086-087-094-095.
IA...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR IAZ008>010-018-019-
029.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
HYDROLOGY....AJ
AREA FORECAST DISCUSSION
NWS ALBANY NY
614 AM EDT MON APR 28 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 615 AM EDT...PATCHY CLOUDS ARE PERSISTING ACROSS PORTIONS OF
THE SOUTHERN GREENS...NORTHERN BERKSHIRES...AND NORTH/CENTRAL
TACONICS...ALBEIT WITH LESS AREAL COVERAGE NOTED OVER THE LAST 2
HOURS. WE EXPECT THESE PATCHY CLOUDS TO CONTINUE TO ERODE OVER THE
NEXT 1-3 HOURS...AS THEY MOVE SOUTH/SOUTHWEST.
OTHERWISE...WE EXPECT GENERALLY MOSTLY SUNNY SKIES TO START THE
DAY. HOWEVER...ADDITIONAL PATCHES OF CLOUDS ARE EXPECTED TO
APPROACH FROM THE NORTHEAST ONCE AGAIN LATER TODAY...AFFECTING
MAINLY SOUTHERN VT...NORTHERN MA...AND POSSIBLY THE UPPER HUDSON
RIVER VALLEY. IN ADDITION...HIGHER CLOUDS WILL BEGIN TO APPROACH
SOUTHERN AND WESTERN AREAS LATE THIS AFTERNOON.
THE CLOUDS ACROSS NORTHEAST AREAS WILL BE THE RESULT OF SOME
RESIDUAL MOISTURE ROTATING AROUND THE WESTERN PERIPHERY OF THE STORM
SYSTEM WELL OFF THE NEW ENGLAND COAST. SOME OF THE HI-RES
MODELS...INCLUDING THE HRRR AND THE OPERATIONAL NAM WRF HINT AT SOME
LIGHT SHOWERS OR SPRINKLES POSSIBLY AFFECTING SOME HIGHER ELEVATIONS
OF SOUTHERN VT BY EVENING. WILL INDICATE SOME SLIGHT CHC POPS FOR
ISOLATED SHOWERS/SPRINKLES IN THIS REGION TO ACCOUNT FOR THIS REMOTE
POSSIBILITY.
DEEP MIXING TODAY TO AROUND 825 MB SHOULD ALLOW TEMPS TO REACH 60-65
IN MOST VALLEY AREAS...AND 55-60 ACROSS HIGHER ELEVATIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
TONIGHT...A DEVELOPING EASTERLY LOW LEVEL FLOW WILL INITIALLY ENHANCE
LOW LEVEL MOISTURE AND LOW CLOUD POTENTIAL ACROSS THE REGION
LATER TONIGHT. THIS IS PARTICULARLY SUGGESTED BY THE RUC-13 AND
NAM...AS WELL AS THE REGIONAL GEM. IN ADDITION...HIGH CLOUDS WILL
CONTINUE TO INCREASE FROM THE SOUTH AND WEST. SO...WILL INDICATE
PARTLY TO MOSTLY CLOUDY SKIES OVERNIGHT...WITH CLOUDS BECOMING
MOST WIDESPREAD AFTER MIDNIGHT. WILL ALSO KEEP SLIGHT CHC POPS
ACROSS PORTIONS OF SOUTHERN VT/NORTHWEST MA FOR SOME ISOLATED
SHOWERS OR SPRINKLES...ESP THIS EVENING. WILL ALSO SIDE ON THE
MILDER SIDE OF GUIDANCE...WITH GENERALLY 40-45 EXPECTED IN
VALLEYS...AND 35-40 ACROSS HIGHER TERRAIN.
TUESDAY...THE MID LEVEL RIDGE AXIS WILL SLOWLY MOVE EAST OF THE
REGION DURING THE DAY...ALLOWING DEEPER MOISTURE TO BEGIN TO
OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST. HOWEVER...IT
APPEARS THAT FOR AREAS NEAR AND E OF THE HUDSON RIVER VALLEY...MOST
OF THE MORNING HOURS SHOULD REMAIN DRY. WILL LIMIT POPS IN THESE
AREAS FOR THE AFTERNOON HOURS...MAINLY IN THE CHC RANGE. TO THE
W...WILL INDICATE MAINLY CHC POPS IN THE MORNING...AND BOOST TO
LIKELY IN THE AFTERNOON. MOST OF THE RAIN SHOULD BE LIGHT...AS IT
WILL ENCOUNTER INITIALLY DRY LOW/MID LEVEL AIR AND MID LEVEL
SUBSIDENCE. TEMPS WILL BE SOMEWHAT TRICKY...AS ANY DELAY IN RAINFALL
WILL ALLOW FOR WARMER MAX TEMPS. WILL SIDE ON THE WARMER SIDE OF
GUIDANCE ACROSS THE UPPER HUDSON RIVER VALLEY AND SOUTHERN
VT...WHERE THE RAIN SHOULD DEVELOP LATEST...AND THE POSSIBILITY FOR
SOME THIN SPOTS ON THE OVERCAST WILL BE GREATEST. IN ADDITION...SOME
ENHANCED DOWNSLOPING WITH THE INCREASING E/SE LOW LEVEL FLOW MAY
HELP BOOST TEMPS FURTHER IN THESE AREAS...WHICH COULD REACH AROUND
60. ELSEWHERE...EXPECT MAX TEMPS TO REACH THE MID/UPPER 50S IN
VALLEYS FROM ALBANY N...W AND NORTHEAST...AND 50-55 TO THE SOUTH AND
WEST WHERE CLOUDS...RAIN...AND A COOLER MARINE MODIFIED AIR MASS
SHOULD KEEP TEMPS COOLER.
TUE NT-WED...ALTHOUGH IT APPEARS UNSETTLED DURING THIS PERIOD...IT
LOOKS LIKE IT WON/T BE A COMPLETE WASHOUT...AS POCKETS OF SYNOPTIC
LIFT MOVE ACROSS THE REGION. HOWEVER...THE GREATEST FORCING AND LOW
LEVEL MOISTURE CONVERGENCE WILL REMAIN MAINLY SOUTH AND WEST OF THE
REGION. SO...EXPECT SEVERAL ROUNDS OF SHOWERS AND/OR PERIODS OF
RAINFALL...BUT THERE COULD EASILY BE SOME PERIODS WHERE ONLY SOME
SPRINKLES OR PATCHY DRIZZLE OCCUR. AS A WEDGE OF DRIER AIR
ADVECTS WESTWARD AROUND THE SOUTHERN PERIPHERY OF THE VERY STRONG
HIGH TO OUR N...THERE IS ACTUALLY SOME POTENTIAL FOR SLEET TO MIX
IN WITH ANY SHOWERS ACROSS HIGHER ELEVATIONS OF THE SOUTHERN
ADIRONDACKS AND WESTERN NEW ENGLAND LATE TUE NT/EARLY WED AM.
TEMPS WILL COOL INTO THE MID 30S TO LOWER 40S TUE NT...AND SHOULD
ONLY REACH THE MID 40S TO LOWER 50S ON WED. IN FACT...SHOULD
RAINFALL BE MORE PERSISTENT/STEADIER ON WED...EVEN COOLER MAX
TEMPS COULD OCCUR...WITH MOST AREAS REMAINING BELOW 50. WINDS WILL
ALSO INCREASE DURING THIS PERIOD AS THE LOW LEVEL PRESSURE
GRADIENT TIGHTENS BETWEEN THE AFOREMENTIONED STRONG EASTERN
CANADIAN HIGH...AND LOW PRESSURE APPROACHING FROM THE SOUTH AND
WEST. EAST/SOUTHEAST WINDS WILL BECOME QUITE GUSTY AT TIMES...WITH
SOME GUSTS OF 30-40 MPH POSSIBLE AT TIMES BY WED
AFTN...PARTICULARLY ACROSS HIGHER ELEVATIONS OF THE
TACONICS...SOUTHERN GREEN MTNS...AND NORTHERN BERKSHIRES...AS WELL
AS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...MOHAWK VALLEY AND
CATSKILLS.
WED NT...THE BEST FORCING FROM THE COMBINATION OF ISENTROPIC
LIFT...MOISTURE TRANSPORT AND LOW LEVEL JET DYNAMICS APPEARS TO BE
DURING THIS PERIOD...LEADING TO WIDESPREAD SHOWERS OR A STEADY RAIN.
SOME OF THE RAIN COULD BE HEAVY AT TIMES. IT WILL ALSO INITIALLY
REMAIN WINDY...ESP THROUGH MIDNIGHT...WHERE SOME GUSTS INTO THE
35-45 MPH RANGE COULD OCCUR IN PORTIONS OF THE SOUTHERN GREENS AND
NORTHERN BERKSHIRES. IT APPEARS THAT A WIDESPREAD 1-2 INCHES OF
RAINFALL SHOULD OCCUR THROUGH DAYBREAK THU...WITH GREATER AMTS
POSSIBLE ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON
VALLEY...AND NW CT. OVERNIGHT MINS SHOULD MAINLY BE IN THE UPPER 30S
TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MORE UNSETTLED WEATHER IS EXPECTED TO LAST THROUGH THE UPCOMING
WEEKEND.
A VERTICALLY STACKED CUTOFF LOW WILL SIT AND SPIN OVER THE GREAT
LAKES REGION AS PIECES OF ENERGY ROTATE AROUND IT ACROSS THE
NORTHEAST. THIS WILL KEEP AT LEAST SCATTERED SHOWERS ACROSS OUR
REGION THURSDAY THROUGH SUNDAY. WHILE IT WILL NOT BE RAINING ALL OF
THE TIME THERE WILL BE PERIODS WHERE THE SHOWERS WILL BE MORE
NUMEROUS WHICH WILL BE ON THURSDAY INTO FRIDAY. RAINFALL AMOUNTS ON
THURSDAY THROUGH THURSDAY NIGHT WILL GENERALLY BE A THIRD OF AN INCH
TO THREE QUARTERS OF AN INCH. EXPECT HIGHS ON THURSDAY TO RANGE FROM
THE UPPER 50S AND LOWER 60S NORTHWEST TO LOWER 70S SOUTHEAST. LOWS
THURSDAY NIGHT WILL BE IN THE UPPER 30S TO UPPER 40S AND HIGHS ON
FRIDAY WILL BE IN THE MID 50S TO MID 60S.
THE UPPER LEVEL TROUGH WILL EXPAND EASTWARD TOWARDS THE NORTHEAST
FOR FRIDAY NIGHT INTO THE WEEKEND...AND START TO WEAKEN SOMEWHAT. AS A
RESULT...WE WILL STILL SEE THE OPPORTUNITY FOR SHOWERS EACH
DAY...MAINLY TIED TO DIURNAL HEATING AND TIMING OF WEAK VORTICITY
MAXES ROTATING AROUND THE UPPER LEVEL LOW. EXPECT LOWS FRIDAY NIGHT
TO RANGE FROM THE UPPER 30S NORTHWEST TO THE MID 40S SOUTHEAST WITH
HIGHS ON SATURDAY IN THE MID 50S TO MID 60S. LOWS ON SATURDAY NIGHT
ARE EXPECTED TO RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S
SOUTHEAST. THERE IS THE POSSIBILITY OF A LITTLE SNOW ACROSS THE
SOUTHERN ADIRONDACKS LATE SATURDAY NIGHT. HIGHS ON SUNDAY WILL BE IN
THE MID 50S TO LOWER 60S.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED AT ALL THE TAF SITES THROUGH THE END
OF THE TAF PERIOD ENDING AT 12Z TUESDAY.
DURING TODAY...N-NW WINDS WILL BE ABOUT 5-10 KTS WITH SCT DIURNAL
CU AT 4-6 KFT DEVELOPING DURING THE DAY. THERE WILL BE SOME
PASSING CIRRUS CLOUDS AS WELL...BUT NO PRECIPITATION IS EXPECTED
DUE TO HIGH PRESSURE NEARBY...AND VFR CONDITIONS WILL CONTINUE.
THE CIRRUS CLOUDS WILL BECOME THICKER BY EVENING.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA.
WEDNESDAY: HIGH OPERATIONAL IMPACT.WINDY WITH GUSTS TO 31.0 LIKELY SHRA.
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. OCNL SHRA.
THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
RH VALUES WILL FALL INTO THE 25-30 PERCENT RANGE THIS AFTERNOON...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY...ALONG WITH A
WETTING RAINFALL.
THE RH WILL FALL INTO THE 25-35 PERCENT RANGE FOR MOST AREAS THIS
AFTERNOON...LOWEST IN VALLEY AREAS. THE RH WILL THEN RECOVER TO
80-95 PERCENT TONIGHT...THEN FALL INTO THE 30-40 PERCENT RANGE FOR
NORTHERN AREAS...AND 40-60 PERCENT RANGE FOR SOUTHERN AND WESTERN
AREAS TUESDAY AFTERNOON.
NORTHWEST WINDS AT 5-10 MPH THIS MORNING WILL BECOME NORTH TO
NORTHEAST AND INCREASE TO 5-15 MPH THIS AFTERNOON...WITH SOME GUSTS
POSSIBLY REACHING UP TO 20 MPH AT TIMES ACROSS PORTIONS OF THE UPPER
HUDSON RIVER VALLEY. WINDS WILL VEER INTO THE EAST TONIGHT AT 5-15
MPH...THEN BECOME E TO SE ON TUESDAY AND INCREASE TO 10-20
MPH...WITH SOME GUSTS OF 20-30 MPH POSSIBLE IN THE AFTERNOON...ESP
ACROSS PORTIONS OF SOUTHERN VT.
A WETTING RAINFALL IS EXPECTED FOR LATE TUESDAY THROUGH THURSDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED THROUGH EARLY IN THE
WEEK.
EXPECTING DRY WEATHER THROUGH TONIGHT AS HIGH PRESSURE DOMINATES.
WET WEATHER WILL RETURN FOR MID WEEK AS A LARGE SLOW MOVING LOW
PRESSURE SYSTEM TO OUR WEST IMPACTS THE REGION. THIS SYSTEM HAS
THE POTENTIAL TO PRODUCE SOME HEAVY RAIN. HOWEVER THERE IS
UNCERTAINTY IN THE POTENTIAL QPF AMOUNTS. AT THIS TIME...IT
APPEARS THAT THE POTENTIAL FOR A WIDESPREAD 1-2 INCHES OF RAINFALL
IS INCREASING...WITH SOME LOCALLY HIGHER AMTS
POSSIBLE...PARTICULARLY ACROSS PORTIONS OF THE SE CATSKILLS...MID
HUDSON VALLEY...AND NW CT. THIS SHOULD CAUSE SIGNIFICANT WITHIN
BANK RISES ON MOST RIVERS...WITH THE POSSIBILITY OF SOME REACHING
ACTION STAGE...ESPECIALLY IN THE HOUSATONIC BASIN...AND POSSIBLY
ACROSS PORTIONS OF THE CATSKILLS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL/FRUGIS/IAA
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...FRUGIS/11
AVIATION...FRUGIS/11
FIRE WEATHER...KL/IAA
HYDROLOGY...KL/IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
605 AM EDT MON APR 28 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 445 AM EDT...PATCHY CLOUDS ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS...AND THE UPPER HUDSON VALLEY REGION ARE FINALLY
BEGINNING TO ERODE. WE EXPECT THESE CLOUDS TO CONTINUE TO DECREASE
IN AREAL COVERAGE THROUGH SUNRISE...ALLOWING TEMPS TO FALL SEVERAL
MORE DEGREES IN MOST AREAS.
AFTER DAYBREAK...WE EXPECT MOSTLY SUNNY SKIES TO START THE DAY.
HOWEVER...ADDITIONAL PATCHES OF CLOUDS ARE EXPECTED TO APPROACH FROM
THE NORTHEAST LATER TODAY...AFFECTING MAINLY SOUTHERN VT...NORTHERN
MA...AND POSSIBLY THE UPPER HUDSON RIVER VALLEY. IN
ADDITION...HIGHER CLOUDS WILL BEGIN TO APPROACH SOUTHERN AND WESTERN
AREAS LATE THIS AFTERNOON.
THE CLOUDS ACROSS NORTHEAST AREAS WILL BE THE RESULT OF SOME
RESIDUAL MOISTURE ROTATING AROUND THE WESTERN PERIPHERY OF THE STORM
SYSTEM WELL OFF THE NEW ENGLAND COAST. SOME OF THE HI-RES
MODELS...INCLUDING THE HRRR AND THE OPERATIONAL NAM WRF HINT AT SOME
LIGHT SHOWERS OR SPRINKLES POSSIBLY AFFECTING SOME HIGHER ELEVATIONS
OF SOUTHERN VT BY EVENING. WILL INDICATE SOME SLIGHT CHC POPS FOR
ISOLATED SHOWERS/SPRINKLES IN THIS REGION TO ACCOUNT FOR THIS REMOTE
POSSIBILITY.
DEEP MIXING TODAY TO AROUND 825 MB SHOULD ALLOW TEMPS TO REACH 60-65
IN MOST VALLEY AREAS...AND 55-60 ACROSS HIGHER ELEVATIONS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
TONIGHT...A DEVELOPING EASTERLY LOW LEVEL FLOW WILL INITIALLY ENHANCE
LOW LEVEL MOISTURE AND LOW CLOUD POTENTIAL ACROSS THE REGION
LATER TONIGHT. THIS IS PARTICULARLY SUGGESTED BY THE RUC-13 AND
NAM...AS WELL AS THE REGIONAL GEM. IN ADDITION...HIGH CLOUDS WILL
CONTINUE TO INCREASE FROM THE SOUTH AND WEST. SO...WILL INDICATE
PARTLY TO MOSTLY CLOUDY SKIES OVERNIGHT...WITH CLOUDS BECOMING
MOST WIDESPREAD AFTER MIDNIGHT. WILL ALSO KEEP SLIGHT CHC POPS
ACROSS PORTIONS OF SOUTHERN VT/NORTHWEST MA FOR SOME ISOLATED
SHOWERS OR SPRINKLES...ESP THIS EVENING. WILL ALSO SIDE ON THE
MILDER SIDE OF GUIDANCE...WITH GENERALLY 40-45 EXPECTED IN
VALLEYS...AND 35-40 ACROSS HIGHER TERRAIN.
TUESDAY...THE MID LEVEL RIDGE AXIS WILL SLOWLY MOVE EAST OF THE
REGION DURING THE DAY...ALLOWING DEEPER MOISTURE TO BEGIN TO
OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST. HOWEVER...IT
APPEARS THAT FOR AREAS NEAR AND E OF THE HUDSON RIVER VALLEY...MOST
OF THE MORNING HOURS SHOULD REMAIN DRY. WILL LIMIT POPS IN THESE
AREAS FOR THE AFTERNOON HOURS...MAINLY IN THE CHC RANGE. TO THE
W...WILL INDICATE MAINLY CHC POPS IN THE MORNING...AND BOOST TO
LIKELY IN THE AFTERNOON. MOST OF THE RAIN SHOULD BE LIGHT...AS IT
WILL ENCOUNTER INITIALLY DRY LOW/MID LEVEL AIR AND MID LEVEL
SUBSIDENCE. TEMPS WILL BE SOMEWHAT TRICKY...AS ANY DELAY IN RAINFALL
WILL ALLOW FOR WARMER MAX TEMPS. WILL SIDE ON THE WARMER SIDE OF
GUIDANCE ACROSS THE UPPER HUDSON RIVER VALLEY AND SOUTHERN
VT...WHERE THE RAIN SHOULD DEVELOP LATEST...AND THE POSSIBILITY FOR
SOME THIN SPOTS ON THE OVERCAST WILL BE GREATEST. IN ADDITION...SOME
ENHANCED DOWNSLOPING WITH THE INCREASING E/SE LOW LEVEL FLOW MAY
HELP BOOST TEMPS FURTHER IN THESE AREAS...WHICH COULD REACH AROUND
60. ELSEWHERE...EXPECT MAX TEMPS TO REACH THE MID/UPPER 50S IN
VALLEYS FROM ALBANY N...W AND NORTHEAST...AND 50-55 TO THE SOUTH AND
WEST WHERE CLOUDS...RAIN...AND A COOLER MARINE MODIFIED AIR MASS
SHOULD KEEP TEMPS COOLER.
TUE NT-WED...ALTHOUGH IT APPEARS UNSETTLED DURING THIS PERIOD...IT
LOOKS LIKE IT WON/T BE A COMPLETE WASHOUT...AS POCKETS OF SYNOPTIC
LIFT MOVE ACROSS THE REGION. HOWEVER...THE GREATEST FORCING AND LOW
LEVEL MOISTURE CONVERGENCE WILL REMAIN MAINLY SOUTH AND WEST OF THE
REGION. SO...EXPECT SEVERAL ROUNDS OF SHOWERS AND/OR PERIODS OF
RAINFALL...BUT THERE COULD EASILY BE SOME PERIODS WHERE ONLY SOME
SPRINKLES OR PATCHY DRIZZLE OCCUR. AS A WEDGE OF DRIER AIR
ADVECTS WESTWARD AROUND THE SOUTHERN PERIPHERY OF THE VERY STRONG
HIGH TO OUR N...THERE IS ACTUALLY SOME POTENTIAL FOR SLEET TO MIX
IN WITH ANY SHOWERS ACROSS HIGHER ELEVATIONS OF THE SOUTHERN
ADIRONDACKS AND WESTERN NEW ENGLAND LATE TUE NT/EARLY WED AM.
TEMPS WILL COOL INTO THE MID 30S TO LOWER 40S TUE NT...AND SHOULD
ONLY REACH THE MID 40S TO LOWER 50S ON WED. IN FACT...SHOULD
RAINFALL BE MORE PERSISTENT/STEADIER ON WED...EVEN COOLER MAX
TEMPS COULD OCCUR...WITH MOST AREAS REMAINING BELOW 50. WINDS WILL
ALSO INCREASE DURING THIS PERIOD AS THE LOW LEVEL PRESSURE
GRADIENT TIGHTENS BETWEEN THE AFOREMENTIONED STRONG EASTERN
CANADIAN HIGH...AND LOW PRESSURE APPROACHING FROM THE SOUTH AND
WEST. EAST/SOUTHEAST WINDS WILL BECOME QUITE GUSTY AT TIMES...WITH
SOME GUSTS OF 30-40 MPH POSSIBLE AT TIMES BY WED
AFTN...PARTICULARLY ACROSS HIGHER ELEVATIONS OF THE
TACONICS...SOUTHERN GREEN MTNS...AND NORTHERN BERKSHIRES...AS WELL
AS ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...MOHAWK VALLEY AND
CATSKILLS.
WED NT...THE BEST FORCING FROM THE COMBINATION OF ISENTROPIC
LIFT...MOISTURE TRANSPORT AND LOW LEVEL JET DYNAMICS APPEARS TO BE
DURING THIS PERIOD...LEADING TO WIDESPREAD SHOWERS OR A STEADY RAIN.
SOME OF THE RAIN COULD BE HEAVY AT TIMES. IT WILL ALSO INITIALLY
REMAIN WINDY...ESP THROUGH MIDNIGHT...WHERE SOME GUSTS INTO THE
35-45 MPH RANGE COULD OCCUR IN PORTIONS OF THE SOUTHERN GREENS AND
NORTHERN BERKSHIRES. IT APPEARS THAT A WIDESPREAD 1-2 INCHES OF
RAINFALL SHOULD OCCUR THROUGH DAYBREAK THU...WITH GREATER AMTS
POSSIBLE ACROSS PORTIONS OF THE SE CATSKILLS...MID HUDSON
VALLEY...AND NW CT. OVERNIGHT MINS SHOULD MAINLY BE IN THE UPPER 30S
TO MID 40S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MORE UNSETTLED WEATHER IS EXPECTED TO LAST THROUGH THE UPCOMING
WEEKEND.
A VERTICALLY STACKED CUTOFF LOW WILL SIT AND SPIN OVER THE GREAT
LAKES REGION AS PIECES OF ENERGY ROTATE AROUND IT ACROSS THE
NORTHEAST. THIS WILL KEEP AT LEAST SCATTERED SHOWERS ACROSS OUR
REGION THURSDAY THROUGH SUNDAY. WHILE IT WILL NOT BE RAINING ALL OF
THE TIME THERE WILL BE PERIODS WHERE THE SHOWERS WILL BE MORE
NUMEROUS WHICH WILL BE ON THURSDAY INTO FRIDAY. RAINFALL AMOUNTS ON
THURSDAY THROUGH THURSDAY NIGHT WILL GENERALLY BE A THIRD OF AN INCH
TO THREE QUARTERS OF AN INCH. EXPECT HIGHS ON THURSDAY TO RANGE FROM
THE UPPER 50S AND LOWER 60S NORTHWEST TO LOWER 70S SOUTHEAST. LOWS
THURSDAY NIGHT WILL BE IN THE UPPER 30S TO UPPER 40S AND HIGHS ON
FRIDAY WILL BE IN THE MID 50S TO MID 60S.
THE UPPER LEVEL TROUGH WILL EXPAND EASTWARD TOWARDS THE NORTHEAST
FOR FRIDAY NIGHT INTO THE WEEKEND...AND START TO WEAKEN SOMEWHAT. AS A
RESULT...WE WILL STILL SEE THE OPPORTUNITY FOR SHOWERS EACH
DAY...MAINLY TIED TO DIURNAL HEATING AND TIMING OF WEAK VORTICITY
MAXES ROTATING AROUND THE UPPER LEVEL LOW. EXPECT LOWS FRIDAY NIGHT
TO RANGE FROM THE UPPER 30S NORTHWEST TO THE MID 40S SOUTHEAST WITH
HIGHS ON SATURDAY IN THE MID 50S TO MID 60S. LOWS ON SATURDAY NIGHT
ARE EXPECTED TO RANGE FROM THE MID 30S NORTHWEST TO THE MID 40S
SOUTHEAST. THERE IS THE POSSIBILITY OF A LITTLE SNOW ACROSS THE
SOUTHERN ADIRONDACKS LATE SATURDAY NIGHT. HIGHS ON SUNDAY WILL BE IN
THE MID 50S TO LOWER 60S.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED AT ALL THE TAF SITES THROUGH THE END
OF THE TAF PERIOD ENDING AT 12Z TUESDAY.
DURING TODAY...N-NW WINDS WILL BE ABOUT 5-10 KTS WITH SCT DIURNAL
CU AT 4-6 KFT DEVELOPING DURING THE DAY. THERE WILL BE SOME
PASSING CIRRUS CLOUDS AS WELL...BUT NO PRECIPITATION IS EXPECTED
DUE TO HIGH PRESSURE NEARBY...AND VFR CONDITIONS WILL CONTINUE.
THE CIRRUS CLOUDS WILL BECOME THICKER BY EVENING.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA.
WEDNESDAY: HIGH OPERATIONAL IMPACT.WINDY WITH GUSTS TO 31.0 LIKELY SHRA.
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. OCNL SHRA.
THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
RH VALUES WILL FALL INTO THE 25-30 PERCENT RANGE THIS AFTERNOON...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...BRINGING SOME
SUNSHINE...AND SEASONABLY MILD TEMPERATURES. A LARGE AND COMPLEX
STORM SYSTEM WILL SLOWLY MOVE NORTHEAST TOWARD THE GREAT LAKES
TONIGHT THROUGH MIDWEEK. THIS WILL BRING A PERIOD OF COOLER AND
UNSETTLED CONDITIONS TO THE REGION THROUGH WEDNESDAY...ALONG WITH A
WETTING RAINFALL.
THE RH WILL FALL INTO THE 25-35 PERCENT RANGE FOR MOST AREAS THIS
AFTERNOON...LOWEST IN VALLEY AREAS. THE RH WILL THEN RECOVER TO
80-95 PERCENT TONIGHT...THEN FALL INTO THE 30-40 PERCENT RANGE FOR
NORTHERN AREAS...AND 40-60 PERCENT RANGE FOR SOUTHERN AND WESTERN
AREAS TUESDAY AFTERNOON.
NORTHWEST WINDS AT 5-10 MPH THIS MORNING WILL BECOME NORTH TO
NORTHEAST AND INCREASE TO 5-15 MPH THIS AFTERNOON...WITH SOME GUSTS
POSSIBLY REACHING UP TO 20 MPH AT TIMES ACROSS PORTIONS OF THE UPPER
HUDSON RIVER VALLEY. WINDS WILL VEER INTO THE EAST TONIGHT AT 5-15
MPH...THEN BECOME E TO SE ON TUESDAY AND INCREASE TO 10-20
MPH...WITH SOME GUSTS OF 20-30 MPH POSSIBLE IN THE AFTERNOON...ESP
ACROSS PORTIONS OF SOUTHERN VT.
A WETTING RAINFALL IS EXPECTED FOR LATE TUESDAY THROUGH THURSDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE ANTICIPATED THROUGH EARLY IN THE
WEEK.
EXPECTING DRY WEATHER THROUGH TONIGHT AS HIGH PRESSURE DOMINATES.
WET WEATHER WILL RETURN FOR MID WEEK AS A LARGE SLOW MOVING LOW
PRESSURE SYSTEM TO OUR WEST IMPACTS THE REGION. THIS SYSTEM HAS
THE POTENTIAL TO PRODUCE SOME HEAVY RAIN. HOWEVER THERE IS
UNCERTAINTY IN THE POTENTIAL QPF AMOUNTS. AT THIS TIME...IT
APPEARS THAT THE POTENTIAL FOR A WIDESPREAD 1-2 INCHES OF RAINFALL
IS INCREASING...WITH SOME LOCALLY HIGHER AMTS
POSSIBLE...PARTICULARLY ACROSS PORTIONS OF THE SE CATSKILLS...MID
HUDSON VALLEY...AND NW CT. THIS SHOULD CAUSE SIGNIFICANT WITHIN
BANK RISES ON MOST RIVERS...WITH THE POSSIBILITY OF SOME REACHING
ACTION STAGE...ESPECIALLY IN THE HOUSATONIC BASIN...AND POSSIBLY
ACROSS PORTIONS OF THE CATSKILLS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/FRUGIS/KL
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...FRUGIS/11
AVIATION...FRUGIS/11
FIRE WEATHER...IAA/KL
HYDROLOGY...IAA/KL
AREA FORECAST DISCUSSION
NWS MIAMI FL
1003 AM EDT MON APR 28 2014
.UPDATE...
NO PLANS FOR CHANGES TO THE CURRENT FORECAST. THE 12Z SOUNDING FOR
MFL SHOWS VERY STEEP MID LEVEL LAPSE RATES COMING IN AT 7C/KM
WHICH IS ABOUT AS UNSTABLE AS IT GETS IN SOUTH FLORIDA. ALONG WITH
WARM SURFACE FORECAST TEMPERATURES OF THE MID 90S ACROSS THE
INTERIOR, THE ONLY MISSING INGREDIENT IS DEEP LAYER MOISTURE
CONTENT WHICH IS SERIOUSLY LACKING. BUT WITH THIS KIND OF
INSTABILITY, A FEW THUNDERSTORMS ARE DEFINITELY POSSIBLE ACROSS
THE INTERIOR AND HRRR DOES SHOW SOME ISOLATED DEVELOPMENT FOR
COLLIER NORTH TO GLADES COUNTIES. THE MARINE FORECAST IS ON TRACK
ALSO SO NO CHANGES PLANNED THEIR EITHER.
KOB
&&
.PREV DISCUSSION... /ISSUED 721 AM EDT MON APR 28 2014/
AVIATION...
LIGHT SOUTHEAST WINDS EARLY THIS MORNING WILL INCREASE TO 10-15
KNOTS WITH HIGHER GUSTS BY MID/LATE MORNING. GULF COAST SEA BREEZE
IS FORECAST AT KAPF THIS AFTERNOON...WITH A SOUTH TO SOUTHWEST
WIND. WINDS WILL DIMINISH THIS EVENING. LOW LEVEL MOISTURE WILL
INCREASE LATE IN THE TAF PERIOD FROM THE SOUTHEAST...BRINGING AN
INCREASE IN CLOUD COVER.
PREV DISCUSSION... /ISSUED 300 AM EDT MON APR 28 2014/
.A FEW THUNDERSTORMS POSSIBLE WESTERN INTERIOR THIS AFTERNOON...
SHORT TERM...
HIGH PRESSURE OVER THE WESTERN ATLANTIC WATERS WILL REMAIN NEARLY
STATIONARY TODAY INTO TUESDAY...AS LOW PRESSURE OVER THE CENTRAL
UNITED STATES MOVES SLOWLY TO THE NORTHEAST TOWARDS THE GREAT
LAKES. A MID TO UPPER LEVEL SHORTWAVE TROUGH OVER THE CENTRAL
GULF OF MEXICO WILL ALSO MOVE EAST AND THROUGH THE FLORIDA
PENINSULA THIS AFTERNOON BEFORE MOVING INTO THE WESTERN ATLANTIC
WATERS TONIGHT.
THIS WEATHER PATTERN WILL ALLOW FOR A SOUTHEAST WIND FLOW OVER
SOUTH FLORIDA TODAY INTO TUESDAY ALONG WITH THE EAST AND WEST
COAST SEA BREEZES DEVELOPING AND PUSHING INLAND EACH DAY. SO THERE
WILL BE A SLIGHT CHANCE OF SHOWERS OVER THE INTERIOR AREAS EACH
AFTERNOON WITH EVEN A SLIGHT CHANCE OF THUNDERSTORMS THIS AFTERNOON
WEST OF LAKE OKEECHOBEE.
THE LOW WILL CONTINUE TO MOVE SLOWLY NORTHEAST ACROSS THE GREAT
LAKES FOR THE MIDDLE TO END OF THE WEEK...AS THE HIGH MOVES SLOWLY
EAST FURTHER INTO THE ATLANTIC WATERS. THIS WILL ALLOW FOR A COLD
FRONT ASSOCIATED WITH THE LOW TO MOVE SOUTHEAST INTO THE
SOUTHEASTERN UNITED STATES FROM THE CENTRAL UNITED STATES. THIS IN
TURN WILL ALLOW FOR THE WIND FLOW OVER SOUTH FLORIDA TO BECOME
MORE SOUTHERLY...AND ALLOW FOR DEEPER TROPICAL MOISTURE TO WORK
INTO THE AREA FROM THE SOUTH. THEREFORE...THE POPS WILL REMAIN IN
THE ISOLATED TO SCATTERED RANGE OVER SOUTH FLORIDA WITH THE
HIGHEST POPS AROUND THE LAKE OKEECHOBEE REGION. THERE COULD ALSO
BE SOME THUNDERSTORMS FOR THE MIDDLE TO END OF THE WEEK OVER THE
INTERIOR AND LAKE OKEECHOBEE REGION.
LONG TERM...
THE COLD FRONT WILL CONTINUE TO MOVE SOUTHWARD THROUGH SOUTH
FLORIDA EARLY NEXT WEEKEND...BEFORE HIGH PRESSURE BUILDS INTO THE
AREA FROM THE NORTH FOR LATE NEXT WEEKEND. THIS WILL KEEP THE
TROPICAL MOISTURE IN PLACE OVER SOUTH FLORIDA EARLY NEXT
WEEKEND...BEFORE DRIER AIR WORKS INTO SOUTH FLORIDA FOR LATE NEXT
WEEKEND. SO WILL KEEP ISOLATED TO SCATTERED POPS OVER SOUTH
FLORIDA FOR THE FIRST HALF OF NEXT WEEKEND...BEFORE GOING DRY FOR
THE SECOND HALF OF NEXT WEEKEND.
MARINE...
THE WINDS WILL BE FROM THE SOUTHEAST AT 10 TO 15 KNOTS TODAY INTO
TUESDAY...BEFORE SWINGING TO A MORE SOUTHERLY DIRECTION FOR THE
MIDDLE TO END OF THE WEEK. THIS WILL KEEP THE SEAS AT BELOW 6 FEET
IN BOTH THE ATLANTIC AND GULF WATERS OF SOUTH FLORIDA THROUGH THE
WEEK.
THERE COULD ALSO BE A NORTHEAST SWELL OF 2 TO 3 FEET THAT WILL
BUILD INTO SOUTH FLORIDA ATLANTIC WATERS LATE THIS WEEK FROM THE
NORTH.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 77 88 77 / 10 10 10 10
FORT LAUDERDALE 87 79 87 79 / 10 10 10 10
MIAMI 88 78 88 78 / 10 10 10 10
NAPLES 89 74 89 74 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
620 AM EDT MON APR 28 2014
.SYNOPSIS...
ATLANTIC HIGH PRESSURE EARLY THIS WEEK WILL DIMINISH AHEAD OF A
SLOW MOVING COLD FRONT...BRINGING UNSETTLED WEATHER FOR THE
MIDDLE OF THE WEEK. THE FRONT WILL THEN LINGER JUST OFFSHORE
THROUGH LATE IN THE WEEK...BEFORE HIGH PRESSURE BUILDS INTO THE
REGION BY NEXT SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
28/09Z RAP SOUNDINGS DEPICTED AN EVEN WEAKER CAP ACROSS INTERIOR
SOUTHEAST SOUTH CAROLINA AHEAD OF THE SEA BREEZE. HAVE OPTED TO
INCLUDE A SLIGHT CHANCE OF SHOWERS/TSTMS FOR A FEW HOURS THIS
AFTERNOON GIVEN THIS TREND. NO OTHER CHANGES WERE MADE TO THE
GOING FORECAST.
A CLASSIC OMEGA BLOCKING PATTERN WILL REMAIN IN TACT ACROSS THE
EASTERN HALF OF THE U.S. TODAY WITH A STRONG AND QUITE PRONOUNCED
UPPER RIDGE CENTERED DIRECTLY OVER THE SOUTHEAST STATES. AT THE
SURFACE...THE AREA IS LOCATED ALONG THE WESTERN FLANKS OF ATLANTIC
HIGH PRESSURE...WHICH IS HELPING TO KEEP ELEVATED DEWPOINTS IN THE
60S IN PLACE. TODAY HAS THE POTENTIAL TO BE THE WARMEST DAY SO FAR
THIS YEAR WITH VARIOUS GUIDANCE TRENDS AND LOW-LEVEL THICKNESSES
SCHEMES SUPPORTING HIGHS IN THE UPPER 80S TO LOWER 90S AWAY FROM
THE BEACHES. THE DEGREE OF WARMTH WILL BE HEAVILY INFLUENCED BY
THE AMOUNT OF CLOUD COVER TODAY. THIN CIRRIFORM CLOUDS TRAVERSING
THE FORECAST AREA THIS MORNING WILL GRADUALLY SHIFT NORTH WITH
BOTH THE CMC AND NAM SIMULATED CLOUD PRODUCTS SHOWING SKIES
CLEARING LATER THIS MORNING. THE RESULTING STRONG INSOLATION AND
60+ DEGREE DEWPOINTS WILL PROMOTE A SHALLOW CUMULUS FIELD FORMING
AHEAD OF THE SEA BREEZE BY THIS AFTERNOON WITH ANOTHER BATCH OF
MID/HIGH-LEVEL CLOUDS STREAMING BACK IN FROM THE WEST CLOSER TO
SUNSET. THE RESULTANT SEA BREEZE CIRCULATION IS EXPECTED TO REACH
THE I-95 CORRIDOR BY MID-AFTERNOON AND FAR INLAND AREAS LATE.
RAP/NAM SOUNDINGS SHOW A PRONOUNCED SUBSIDENCE INVERSION
ASSOCIATED WITH THE MID/UPPER-LEVEL RIDGE AXIS. THIS INVERSION IS
FORECAST TO HOLD FOR MUCH OF THE DAY...DESPITE TEMPERATURES
WARMING TO NEAR 90 DEGREES. THERE ARE SOME SIGNALS THAT THE CAP
MAY WEAKEN JUST ENOUGH ACROSS THE NORTHERN HALF OF THE FORECAST
AREA TO SUPPORT AN ISOLATED SHOWER/TSTM ALONG THE BROAD LOW-LEVEL
CONVERGENCE ZONE ASSOCIATED WITH THE THERMALLY DIRECT SEA BREEZE
CIRCULATION...BUT MOST OF THE HIGHER RESOLUTION MODEL RUNS SHOW
LITTLE...IF ANY...QPF. SINCE THE MODELS HAVE BEEN TOO AGGRESSIVE
WITH CONVECTIVE DEVELOPMENT WITHIN THIS SUBSIDENT REGIME OVER THE
PAST FEW DAYS...POPS WILL BE HELD BELOW MENTIONABLE THRESHOLDS FOR
THE AFTERNOON HOURS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...THE RESULTANT SEA BREEZE WILL CLEAR THE FAR WESTERN
AREAS SHORTLY AFTER SUNSET AS THE AREA REMAINS ALONG THE WESTERN
FLANKS OF ATLANTIC HIGH PRESSURE. LOW-LEVEL WIND FIELDS ARE
FORECAST TO INCREASE OVERNIGHT AS NOCTURNAL JETTING INTENSIFIES
AHEAD OF AN APPROACHING COLD FRONT. THIS SHOULD KEEP THE
ATMOSPHERE FAIRLY WELL MIXED OVERNIGHT AND KEEPING THE BOUNDARY
LAYER FROM FULLY DECOUPLING. THIS WILL RESULT IN A WARM AND FAIRLY
HUMID NIGHT WITH LOWS RANGING FROM THE MID 60S WELL INLAND TO
AROUND 70 ACROSS THE COASTAL COUNTIES. IT WILL BE A DRY NIGHT WITH
ANY SHOWER ACTIVITY THAT DEVELOPS LIKELY REMAINING WELL TO THE WEST
THROUGH SUNRISE AND POSSIBLY OVER THE WESTERN WALL OF THE GULF
STREAM.
TUESDAY...THE AXIS OF THE UPPER RIDGE WILL SHIFT INTO THE NEARBY
ATLANTIC WATERS DURING THE MORNING HOURS...AS A ROBUST STACKED LOW
SYSTEM BEGINS TO BREAK THE OMEGA BLOCKING PATTERN AND MOVE
NORTH/NORTHEAST ACROSS THE MID MISSISSIPPI VALLEY. THE SOUTHEAST
STATES WILL BECOME LOCATED BETWEEN A WARM FRONT LIFTING WELL NORTH
OF THE AREA AND THE COLD FRONT TRAILING FROM THE LOW SYSTEM FAR
UPSTREAM. SOLID SOUTHERLY FLOW WILL CONTINUE TO SUPPORT INCREASING
LOW LEVEL MOISTURE AND WARM TEMPERATURES PEAKING FAR ABOVE
SEASONAL NORMALS. AS A RESULT...DECENT INSTABILITY WILL DEVELOP
TUESDAY AFTERNOON...WHILE MID LEVEL LAPSE RATES INCREASE UP TO 7
C/KM. A BAND OF WEAK SHORTWAVE ENERGY RIDING ALONG THE PERIPHERY
OF THE RETREATING UPPER RIDGE COULD PROVIDE SOME FORCING.
YET WITH STRONGEST DYNAMICS STILL WEST OF THE AREA...BEST
CONVECTIVE COVERAGE WILL BE ACROSS INLAND AREAS...AS THUNDERSTORM
DEVELOPMENT AND INTENSIFICATION WILL BE MAINLY DRIVEN BY SEABREEZE
AND BOUNDARY INTERACTIONS. WILL STILL NEED TO MONITOR FOR THE
POSSIBILITY THAT AN ISOLATED THUNDERSTORM COULD BECOME ORGANIZED
OR SEVERE WITHIN LOW TO MODERATE INSTABILITY AND SOME INCREASE IN
SHEAR PROFILES...ESPECIALLY IF ANY ONGOING UPSTREAM CONVECTION CAN
SLIP INTO THE FAR WESTERN PERIPHERY LATE IN THE DAY. CONSIDERING
THE STEADILY INTENSIFYING UPPER LEVEL SUPPORT AHEAD OF THE
IMPRESSIVE LOW SYSTEM TO THE WEST...WILL MAINTAIN SLIGHT TO LOW
CHANCE POPS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT.
WEDNESDAY...THE COLD FRONT TRAILING FROM THE MASSIVE LOW SYSTEM
NOW LOCATED ACROSS THE OHIO VALLEY/GREAT LAKES REGION WILL MAKE
SLOW YET GRADUAL PROGRESS EASTWARD. THE FORECAST AREA WILL REMAIN
IN THE WARM SECTOR OF THE APPROACHING SYSTEM...WITH THE SLOW-
MOVING FRONT JUST ALONG THE WESTERN PERIPHERY OF THE AREA BY
DAYBREAK THURSDAY. DESPITE THICK CLOUDS REDUCING INSOLATION AS
WELL AS INCREASING SHOWER/THUNDERSTORM COVERAGE...TEMPERATURES
WILL STILL RISE INTO THE LOW TO MID 80S WITHIN WARM SOUTHERLY
FLOW AND SOME PRE-FRONTAL COMPRESSION EFFECTS. AS BOTH LOW LEVEL
AND UPPER LEVEL JETTING INCREASE ACROSS THE SOUTHEAST AND MID-
ATLANTIC STATES DOWNSTREAM OF THE UPPER TROUGH AXIS...SHEAR WILL
ALSO INCREASE ACROSS THE AREA AT THE SAME TIME THAT MID LEVEL
LAPSE RATES REACH 7 TO 7.5 C/KM. THUNDERSTORM COVERAGE WILL BE
HIGHEST LATE WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...WITH
RAIN CHANCES UP TO 50 PERCENT DURING THIS TIME FRAME. CONSIDERING
SUCH A STRONGLY DYNAMIC SYSTEM...THERE IS STILL A POTENTIAL FOR
ISOLATED THUNDERSTORMS TO BECOME SEVERE...ESPECIALLY WHERE
BOUNDARY INTERACTIONS OCCUR AND ENHANCE UPDRAFT STRENGTH. THE MAIN
LIMITING FACTOR WOULD BE SUPPRESSED INSTABILITY IN AREAS OF THICK
CLOUD COVER AND HEAVY RAIN.
THURSDAY...THE COLD FRONT WILL SLOWLY PROGRESS THROUGH THE
FORECAST AREA AND INTO THE COASTAL WATERS THROUGH THE DAY. IT
APPEARS THAT THE BULK OF THE CONVECTION WILL HAVE OCCURRED AHEAD
OF THE ACTUAL FRONT...AND THUS RAIN COVERAGE WILL BE DOWN TO
SCATTERED OR EVEN ISOLATED AS THE FRONT MOVES THROUGH REGION.
PROGRESSION OF THE FEATURE APPEARS TO SLOW EVEN FURTHER LATE IN
THE DAY...ALLOWING CONVERGENCE AND DEEP MOISTURE ALONG THE
FRONTAL ZONE TO LINGER ALONG COASTAL AREAS THROUGH THE NIGHTTIME
HOURS. HAVE THUS MAINTAINED SLIGHT TO LOW CHANCE POPS INTO FRIDAY
MORNING. HIGH TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN
SEEN DURING THE EARLY TO MID WEEK PERIOD...PEAKING IN THE LOW 80S
AWAY FROM THE LOCALLY COOLER COASTLINE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE NUMERICAL MODEL SOLUTIONS ARE COMING INTO BETTER
AGREEMENT REGARDING THE POTENTIAL FOR THE OFFSHORE FRONT TO LINGER
NEARBY THROUGH THURSDAY NIGHT. SHORTWAVE ENERGY WILL SWING ACROSS
THE GULF COAST STATES INTO THE SOUTHEAST REGION ALONG THE BASE OF
THE LONGWAVE UPPER TROUGH...PROVIDING SUFFICIENT ENERGY TO DEVELOP
A WEAK WAVE OF LOW PRESSURE ALONG THE MEANDERING BOUNDARY. AS
THIS OCCURS...CONVECTION WILL ONCE AGAIN SPREAD INLAND ON
FRIDAY...BEFORE THE FRONT IS PULLED OFFSHORE WITH THE SURFACE
WAVE FRIDAY NIGHT. SURFACE HIGH PRESSURE WILL FINALLY BE ABLE TO
BUILD INTO THE REGION...WHILE THE EARLIER HIGHLY AMPLIFIED PATTERN
ALOFT DAMPENS INTO NEARLY ZONAL FLOW BY EARLY NEXT WEEK. RAIN
CHANCES PEAKING IN THE 40 PERCENT RANGE FRIDAY AFTERNOON WILL THEN
STEADILY TREND DOWNWARD FRIDAY NIGHT INTO SATURDAY...WITH POPS
FALLING BELOW 15 PERCENT SATURDAY NIGHT INTO MONDAY.
HIGH TEMPERATURES WILL BE COOLEST ON FRIDAY...PEAKING ONLY IN THE
LOW TO MID 70S...BEFORE TRENDING BACK UP TOWARD SEASONAL NORMALS
IN THE UPPER 70S FOR THE REMAINDER OF THE PERIOD. LOW TEMPERATURES
WILL FALL INTO THE LOW TO MID 50S FRIDAY AND SATURDAY
NIGHTS...THEN ALSO MODERATE A FEW DEGREES FOR THE NIGHTTIME HOURS
EARLY NEXT WEEK.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
VFR.
EXTENDED AVIATION OUTLOOK...THE MOST LIKELY PERIOD WITH FLIGHT
RESTRICTIONS IS WEDNESDAY INTO THURSDAY DUE TO SHRA/TSRA ASSOCIATED
WITH THE NEXT COLD FRONT. BREEZY CONDITIONS BOTH TUESDAY AND
WEDNESDAY AT THE TERMINALS.
&&
.MARINE...
TODAY...NO CONCERNS. SOUTHERLY WIND REGIME WILL PERSIST WITH WINDS
10-15 KT AND SEAS 2-3 FT WITH AN UNDERLYING 1-2 FT 8-9 SECOND
GROUND SWELL.
TONIGHT...WINDS WILL INCREASE IN RESPONSE TO NOCTURNAL JETTING.
MIXING PROFILES WILL NOT BE IDEAL IN THE SOUTHERLY WIND REGIME SO
WINDS WERE CAPPED AT 15-20 KT. SEAS WILL BUILD 3-4 FT NEARSHORE
WATERS AND 4-5 FT OFFSHORE WATERS.
TUESDAY AND WEDNESDAY...THE PRESSURE GRADIENT WILL TIGHTEN AHEAD
OF A SLOW-MOVING COLD FRONT INTO THE MID WEEK PERIOD. EXPECT
SOUTHERLY FLOW TO INCREASE AND SEAS TO BUILD ACCORDINGLY. MIXING
WILL BE SOMEWHAT LIMITED WITHIN THE WARM ADVECTION
REGIME...HOWEVER ENHANCEMENTS FROM THE AFTERNOON SEA BREEZE AND
NOCTURNAL LOW LEVEL JETTING COULD SUPPORT MARGINAL SMALL CRAFT
ADVISORY CONDITIONS AT TIMES...ESPECIALLY IN CHARLESTON HARBOR
AND THE OUTER GEORGIA WATERS.
THURSDAY THROUGH FRIDAY...THE COLD FRONT WILL STRUGGLE TO SHIFT
THROUGH THE WATERS...LIKELY STALLING OVER OR NEAR THE MARINE AREA
LATE IN THE WEEK. ANY LINGERING ADVISORY-LEVEL WINDS OR SEAS WILL
LIKELY WILL END BY THURSDAY MORNING AND REMAIN BELOW CRITERIA FRIDAY.
MARINERS ARE CAUTIONED THAT SOME STRONG OR SEVERE STORMS COULD
IMPACT THE COASTAL WATERS WEDNESDAY AND THURSDAY. REMEMBER TO
MAINTAIN A WEATHER WATCH AND MONITOR NOAA WEATHER RADIO...ALL
HAZARDS.
RIP CURRENTS...MID TO HIGH-END LOW RISK FOR TODAY GIVEN STEADY
ONSHORE WINDS AND A 8 TO OCCASIONAL 9 SECOND 1-2 FT GROUND SWELL.
AN ENHANCED RISK FOR RIP CURRENTS IS POSSIBLE TUESDAY AND PERHAPS
WEDNESDAY GIVEN THE NEW MOON AND STRONGER ONSHORE WINDS.
&&
.TIDES/COASTAL FLOODING...
GIVEN INFLUENCES FROM THE UPCOMING NEW MOON AND AN INCREASING AND
PERSISTENT ONSHORE WINDS...TIDAL DEPARTURES MAY BE ENOUGH TO
RESULT IN SHALLOW COASTAL FLOODING WITH THE EVENING HIGH TIDES
THROUGH EARLY THIS WEEK...MAINLY ACROSS SOUTH COASTAL SOUTH
CAROLINA.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1035 AM EDT MON APR 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EDT MON APR 28 2014
A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY
MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK.
THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING
WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 950 AM EDT MON APR 28 2014
RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST
HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN
OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL
TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER
CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING
MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO
NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY
CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS
FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP
MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT
HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED
ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING
DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS
CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL
DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER
UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP
SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK
LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE
POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO
LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT
READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS
SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT
THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER
LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL
TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES
THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH
ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY
TODAY.
SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA
STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS
AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A
LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF
CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO
CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE
AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID
AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM
DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH
ACTIVITY TONIGHT NEAR THE SURFACE FRONT.
TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE
OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE.
ONLY MINOR ADJUSTMENTS PLANNED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 304 AM EDT MON APR 28 2014
MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST
FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE
WEATHER UNSETTLED.
BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER
LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON
TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME.
WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND
TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS
FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON
TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY
DEVELOP.
WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT
AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES.
BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR
TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF
THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES THURSDAY WILL LIFT NORTH INTO
SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY.
A CYCLONIC UPPER FLOW FROM THIS UPPER LOW WILL KEEP MOSTLY CLOUDY
SKIES AND CHANCES OF SHOWERS THURSDAY INTO SATURDAY. A WEAK COLD
FRONT WILL MOVE ACROSS OUR REGION EARLY SATURDAY FOLLOWED BY A HIGH
PRESSURE RIDGE SATURDAY NIGHT. SEVERAL MODELS INDICATE ANOTHER
CHANCE OF PRECIPITATION MAY BEGIN SUNDAY AS ANOTHER SYSTEM
APPROACHES.
ADDED ISOLATED THUNDER TO SUNDAY AS MODELS INDICATE MU CAPES OF UP
TO 500 J/KG. OTHERWISE...ANY PRECIPITATION WILL BE ONLY BE
SCATTERED LIGHT SHOWERS OR SPRINKLES.
TEMPERATURES WILL REMAIN QUITE COOL THURSDAY THROUGH SATURDAY AND
THEN MODERATE A LITTLE SUNDAY. ONLY MADE MINOR TWEAKS TO ALL BLEND
TEMPERATURES MAINLY TO RAISE MINS SLIGHTLY THURSDAY AND FRIDAY NIGHT
AS THERE WILL BE LOTS OF CLOUDS.
&&
.AVIATION /DISCUSSION FOR 281200Z TAF ISSUANCE/...
ISSUED AT 1032 AM EDT MON APR 28 2014
1430Z UPDATE...FEW UPDATES TO THE TAFS. REMOVED -SHRA AND TS FOR
THE NEXT SEVERAL HOURS AND LOWERED THE FLIGHT CATEGORY TO IFR FOR
THE NEXT SEVERAL HOURS AT OUTLYING SITES SUCH AS KHUF AND KBMG
BASED ON OBSERVATIONS. KIND AND KLAF APPEAR TO BE REMAINING AT
MFVR AND GETTING DOUBTFUL THEY WILL REACH VFR BEFORE NEXT SYSTEM
MOVES THROUGH LATER TODAY. PREVIOUS DISC FOLLOWS.
NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS EARLY THIS MORNING.
THERE COULD BE ANOTHER PERIOD OF NUMEROUS SHOWERS AND THUNDERSTORMS
LATE THIS AFTERNOON OR EARLY TONIGHT PER MODELS. OTHERWISE...WILL
MENTION VCSH REST OF THE PERIOD THROUGH MIDNIGHT TONIGHT.
STRONG LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE SLOWLY
NORTHEAST INTO THE UPPER MIDWEST. SHOWERS AND A FEW THUNDERSTORMS
THIS MORNING MAY IN MVFR CONDITIONS AT TIME. MOST OF THE SHOWERS
SHOULD MOVE OUT BY 15Z...BUT AREAS OF MVFR CEILINGS MAY PERSIST INTO
MIDDAY.
SEVERAL MODELS INDICATE THERE COULD BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. WILL ADD
ANOTHER PERIOD OF VCTS AS A RESULT FROM 20Z TO ABOUT 05Z. NAM
REFLECTIVITY MODEL MOST OF THIS WILL MOVE OUT AFTER MIDNIGHT AS A
DRY SLOT PUSHES INTO OUR AREA. COULD BE ANOTHER PERIOD OF MVFR
CEILINGS TONIGHT.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....JH
AVIATION...SMF/JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
950 AM EDT MON APR 28 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EDT MON APR 28 2014
A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY
MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK.
THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING
WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 950 AM EDT MON APR 28 2014
RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST
HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN
OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL
TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER
CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING
MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO
NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY
CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS
FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP
MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT
HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED
ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING
DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS
CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL
DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER
UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP
SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK
LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE
POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO
LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT
READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS
SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT
THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER
LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL
TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES
THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH
ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY
TODAY.
SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA
STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS
AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A
LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF
CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO
CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE
AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID
AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM
DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH
ACTIVITY TONIGHT NEAR THE SURFACE FRONT.
TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE
OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE.
ONLY MINOR ADJUSTMENTS PLANNED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 304 AM EDT MON APR 28 2014
MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST
FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE
WEATHER UNSETTLED.
BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER
LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON
TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME.
WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND
TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS
FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON
TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY
DEVELOP.
WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT
AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES.
BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR
TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF
THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES THURSDAY WILL LIFT NORTH INTO
SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY.
A CYCLONIC UPPER FLOW FROM THIS UPPER LOW WILL KEEP MOSTLY CLOUDY
SKIES AND CHANCES OF SHOWERS THURSDAY INTO SATURDAY. A WEAK COLD
FRONT WILL MOVE ACROSS OUR REGION EARLY SATURDAY FOLLOWED BY A HIGH
PRESSURE RIDGE SATURDAY NIGHT. SEVERAL MODELS INDICATE ANOTHER
CHANCE OF PRECIPITATION MAY BEGIN SUNDAY AS ANOTHER SYSTEM
APPROACHES.
ADDED ISOLATED THUNDER TO SUNDAY AS MODELS INDICATE MU CAPES OF UP
TO 500 J/KG. OTHERWISE...ANY PRECIPITATION WILL BE ONLY BE
SCATTERED LIGHT SHOWERS OR SPRINKLES.
TEMPERATURES WILL REMAIN QUITE COOL THURSDAY THROUGH SATURDAY AND
THEN MODERATE A LITTLE SUNDAY. ONLY MADE MINOR TWEAKS TO ALL BLEND
TEMPERATURES MAINLY TO RAISE MINS SLIGHTLY THURSDAY AND FRIDAY NIGHT
AS THERE WILL BE LOTS OF CLOUDS.
&&
.AVIATION /DISCUSSION FOR 281200Z TAF ISSUANCE/...
ISSUED AT 700 AM EDT MON APR 28 2014
NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS EARLY THIS MORNING.
THERE COULD BE ANOTHER PERIOD OF NUMEROUS SHOWERS AND THUNDERSTORMS
LATE THIS AFTERNOON OR EARLY TONIGHT PER MODELS. OTHERWISE...WILL
MENTION VCSH REST OF THE PERIOD THROUGH MIDNIGHT TONIGHT.
STRONG LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE SLOWLY
NORTHEAST INTO THE UPPER MIDWEST. SHOWERS AND A FEW THUNDERSTORMS
THIS MORNING MAY IN MVFR CONDITIONS AT TIME. MOST OF THE SHOWERS
SHOULD MOVE OUT BY 15Z...BUT AREAS OF MVFR CEILINGS MAY PERSIST INTO
MIDDAY.
SEVERAL MODELS INDICATE THERE COULD BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. WILL ADD
ANOTHER PERIOD OF VCTS AS A RESULT FROM 20Z TO ABOUT 05Z. NAM
REFLECTIVITY MODEL MOST OF THIS WILL MOVE OUT AFTER MIDNIGHT AS A
DRY SLOT PUSHES INTO OUR AREA. COULD BE ANOTHER PERIOD OF MVFR
CEILINGS TONIGHT.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....JH
AVIATION...50/JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1101 AM EDT MON APR 28 2014
LATEST UPDATE...
UPDATE/MARINE
.SYNOPSIS...
ISSUED AT 325 AM EDT MON APR 28 2014
AN EXPANSIVE AND STRONG SYSTEM CENTERED ACROSS THE CENTRAL PLAINS
STATES WILL DRIVE RAINFALL INTO THE AREA AHEAD OF AN ASSOCIATED
FRONTAL SYSTEM TO OUR SOUTH. COOL AND WINDY CONDITIONS CAN BE
EXPECTED TODAY WITH AN INCREASING CHANCE OF RAIN. RAIN WILL CONTINUE
INTO EARLY TUESDAY BEFORE THE RAIN MOVES NORTH AND A SHORT PERIOD OF
WARMER AIR MOVES IN ACROSS THE AREA. ADDITIONAL SHOWERS AND STORMS
WILL BE POSSIBLE TUESDAY AND WEDNESDAY AS ADDITIONAL WAVES OF LOW
PRESSURE MOVE THROUGH THE AREA. COOLER CONDITIONS WILL THEN RETURN
FOR LATE THIS WEEK ALONG WITH A CONTINUED CHANCE OF RAIN SHOWERS.
&&
.UPDATE...
ISSUED AT 1056 AM EDT MON APR 28 2014
WILL KEEP THE WIND ADVISORY GOING. WHILE OBS ARE MOSTLY BELOW
CRITERIA...THE MODELS SUGGEST MIXING HEIGHTS WILL INCREASE EARLY
THIS AFTERNOON AS THE LOW LEVEL JET STRENGTHENS. WE ARE ALSO
SEEING SOME POWER OUTAGES SHOWING UP ON THE CONSUMERS WEBSITE.
THE BAND OF SHOWERS MOVING IN FROM THE SOUTH CONTINUES TO WEAKEN.
WHILE MOST LOCATIONS WILL SEE SOME PRECIPITATION...WHAT DOES FALL
TH IS AFTERNOON SHOULD BE LIGHT. SO I FEATURES LIGHT RAIN
SHOWERS...AND TONED BACK THE THUNDER WORDING. MODELS SHOWING NO
INSTABILITY THROUGH 00Z TUE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
THE MAIN CHANGE WITH THIS FCST PACKAGE IS TO EXPAND THE WIND
ADVISORY TO THE EAST THROUGH THE REMAINDER OF THE CWFA FOR TODAY.
OTHERWISE...THE FCST REMAINS MAINLY ON TRACK WITH A SLIGHTLY SLOWER
TREND TO THE RAIN MOVING IN FOR TODAY.
REGARDING THE EXPANSION OF THE WIND ADVISORY FIRST...WINDS REMAIN
RATHER BRISK AND THIS EARLY MORNING HOUR ACROSS THE CWFA. SOME GUSTS
OF AROUND 30 KNOTS ARE ALREADY OCCURRING THIS MORNING...AND THIS
WILL ONLY INCREASE DURING THE DAYLIGHT HOURS AS THE GRADIENT
TIGHTENS MORE AND AS DIURNAL MIXING WILL HELP TO BRING SOME OF THE
STRONGER WINDS DOWN FROM ALOFT. IT SEEMS THAT 40 KNOTS SHOULD BE
PRETTY EASY TO MIX DOWN...EVEN IN A WAA PATTERN.
AS FAR AS THE RAINFALL IS CONCERNED...THE TREND OVER THE PAST 24
HOURS IS THAT OF A SLOWER ONE WITH THE FEED OF DRY AIR COMING IN ON
THE BRISK ERLY WINDS AND HELPING TO DIMINISH MOST ALL PCPN TRYING TO
MOVE IN. THE UPPER RIDGE AXIS THAT IS ONLY SLOWLY CRAWLING EASTWARD
ACROSS THE CWFA IS FAR ENOUGH EAST AT THIS TIME THAT ENOUGH MOISTURE
TRANSPORT IS OCCURRING AND A COUPLE OF SPRINKLES/LIGHT SHOWERS ARE
OCCURRING ACROSS THE FAR SW CORNER OF THE CWFA. WE DO EXPECT THAT
PCPN WILL BE ON THE INCREASE TODAY FROM SW TO NE AS THE UPPER LOW
ROTATES A LITTLE CLOSER. THUNDER IS STILL POSSIBLE ACROSS THE FAR
SOUTH THIS AFTERNOON AS SLIGHTLY NEGATIVE ELEVATED LI/S MOVE UP INTO
THE AREA. SEVERE WX IS NOT EXPECTED AT THIS TIME WITH NO SFC
INSTABILITY EXPECTED THROUGH TONIGHT.
THE BEST THREAT OF RAIN SHOWERS AND STORMS LOOKS TO COME THIS
EVENING AND INTO THE OVERNIGHT HOURS. THE BEST MOISTURE AXIS PASSES
FROM SOUTH TO NORTH DURING THIS TIME FRAME...OUT AHEAD OF THE
OCCLUDED FRONT. WE CONTINUE TO EXPECT LITTLE THREAT OF SEVERE STORMS
TONIGHT ONCE AGAIN AS THE INSTABILITY WILL ONCE AGAIN BE ELEVATED.
THE RAIN CHANCES WILL THEN DIMINISH LATE TONIGHT AND EARLY TUE
MORNING AS THE MOISTURE TRANSPORT AND LLJ PEEL OFF TO THE EAST OF
THE STATE.
WE CONTINUE TO LOOK FOR A BRIEF WARM UP FOR THE DAY ON TUE WITH 70
DEGREE TEMPERATURES LOOKING MORE LIKELY. THE FRONT WILL BE NEAR THE
SRN STATE BORDER AT 12Z ON TUE. THE UPPER LOW COMING IN FROM THE
WEST WILL PUSH THE FRONT NORTH THROUGH THE AREA. EVEN THOUGH IT WILL
NOT BE THE TRUE WARM SECTOR...H850 TEMPS ARE STILL VERY MILD...AND
WILL WE TAP THAT WARMTH AS THE DRY SLOT MOVES IN AND WE GET SOME
SUN. H850 TEMPS AROUND +10 C WILL SUPPORT MANY LOCATIONS HITTING 70.
IT DOES LOOK LIKE LATE IN THE AFTERNOON WE WILL SEE CONVECTION TRY
TO FIRE OVERHEAD AS A WAVE ROTATES AROUND THE UPPER LOW AND MOVES
TOWARD THE AREA.
THERE IS SOME CONCERN WITH CONVECTION FIRING ON TUE AFTERNOON AS
STRONG JET STREAM WINDS WILL STILL BE OVERHEAD ACROSS SE LOWER.
THIS WILL PROVIDE FOR GOOD SHEAR IN THE DEEP LAYER. MUCH BETTER
INSTABILITY /LI/S OF -6 TO -8C/ WILL BE FOUND FURTHER SE ALSO.
WE STAY RELATIVELY WARM THROUGH MOST OF WED AS THE LOW LEVEL COLD
AIR DOES NOT COME IN UNTIL LATE WED AFTERNOON AND WED EVENING. THIS
IS THE CASE AS THE UPPER LOW HELPS ANOTHER WAVE TOWARD THE AREA AND
THE FLOW AHEAD OF IT WILL CONTINUE TO SUPPORT WARM TEMPS UNTIL THE
LOW MOVES THROUGH LATE WED. SHOWERS AND STORMS WILL REMAIN POSSIBLE
AHEAD OF THIS WAVE FOR TUE NIGHT AND WED. WE WILL LIKELY NOT REACH
70 AGAIN...BUT WE SHOULD BE WELL INTO THE 60S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
LITTLE QUESTION OCCASIONAL SHOWERS AND COOLER THAN NORMAL
TEMPERATURES WILL PREVAIL THROUGH SATURDAY AS WE REMAIN ON THE
CYCLONIC SIDE OF THE UPPER JET WITH A FAIR AMOUNT OF DEEP MOISTURE.
SOME QUESTION ARISES WHAT HAPPENS FROM SUNDAY AND BEYOND SO I KEEP
THE LOW CHANCE POP FOR SUNDAY BUT IT MAY BE WE ACTUALLY GET TO SEE
THE SUN ONCE AGAIN BY SUNDAY AS THE UPPER JET MAY FINALLY LIFT NORTH
OF LOWER MICHIGAN MY THEN.
MODEL CONTINUE TO BE IN GOOD AGREEMENT WITH THE CLOSED UPPER LOW
REMAINING IN PLACE INTO AS LEAST SATURDAY. THE 500 MB HEIGHT
ANOMALIES ARE ON THE ORDER OF 2-3 STD BELOW NORMAL INTO SATURDAY
OVER THE LOWER GREAT LAKES. 850 MB TEMPERATURES ARE 1 TO 2 STD BELOW
NORMAL INTO SATURDAY.
THE MODELS CONTINUE TO FEATURE THAT ARCTIC JET STREAK FEEDING INTO
THE SYSTEM FRIDAY INTO SATURDAY. THAT WILL MAINTAIN THIS PATTERN
INTO SATURDAY FOR SURE. FROM SUNDAY ON THERE IS A QUESTION OF
WHETHER ANOTHER PACIFIC SYSTEM CAN BREAK THROUGH THE WESTERN RIDGE
TO PUSH THIS PATTERN OUT OF THE WAY OR IF WE WILL CONTINUE TO SEE
MORE IN A SERIES OF NORTHERN STREAM OF SYSTEMS. I KEEP LOW CHANCE
POPS FOR SUNDAY JUST IN CASE THE LATER OCCURS.
AS FOR THE SHOWERS WEDNESDAY NIGHT THROUGH SATURDAY AFTERNOON...
GIVEN THE DEEP CYCLONIC FLOW...DEEP MOISTURE AND SATURATED DGZ PLUS
SURFACE CONVERGENCE ALONG THE LAKE MICHIGAN SHORE AREAS INTO
SATURDAY I HAVE TO BELIEVE WE WILL CONTINUE TO SEE LIGHT SHOWER
THROUGH THIS ENTIRE PERIOD. I HAVE CONTINUED THE LIKELY POPS INTO
FRIDAY AND HIGH CHANCE INTO SATURDAY. TEMPERATURES WILL BE BETWEEN 5
AND 10 DEGREES BELOW NORMAL THROUGH THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 741 AM EDT MON APR 28 2014
OUR MAJOR QUESTION IS WHEN WILL THE RAIN ARRIVE AND MORE THAN THAT
WHEN WILL THE MVFR/IFR CIGS/VSBY MOVE IN AS THE STORM TO OUR
SOUTHWEST SLOWLY MOVES TOWARD THE REGION. THE HUDSON BAY HIGH
CONTINUES TO FEED VERY DRY AIR FROM THE EAST AND IT WILL CONTINUE
TO ERROD THE RAIN AS MOVES INTO SOUTHWEST MICHIGAN. THIS IS NOT TO
SAY THERE WILL NOT BE SOME LIGHT RAIN SHOWERS BUT IT SEEMS THE
BULK OF THE SIGNIFICANT RAIN WILL LARGELY STAY NEAR AND SOUTH OF
INTERSTATE 94 TODAY (USING THE RAP13 MODEL AND HRRR ).
I DID BRING THE SHOWERS INTO THE AZO...BTL AND JXN BY LATE MORNING
BUT I DID NOT BRING THOSE SHOWERS INTO GRR...MKG AND LAN TILL LATE
AFTERNOON... EVEN THEN VSBY SHOULD BE VFR FOR THE MOST PART. I PUT
VCSH AT ALL THE TAF SITES DURING THE MID MORNING HOURS SINCE
SHOWERS WILL BE AROUND BUT VERY LIGHT (MOSTLY SPRINKLES).
THE MVFR CIGS/VSBY SHOULD REACH THE I-94 TAT SITES BY LATE
AFTERNOON THEN SPREAD INTO THE I-96 SITES AFTER 00Z. ANY
THUNDERSTORM ACTIVITY SHOULD HOLD OFF UNTIL TUESDAY.
&&
.MARINE...
ISSUED AT 1056 AM EDT MON APR 28 2014
GALE WARNING TO CONTINUE. SOME GUSTS OVER GALE FORCE ALREADY
OBSERVED. WINDS LIKELY TO INCREASE AS THE LOW LEVEL JET
STRENGTHENS AND MIXING HEIGHTS INCREASE.
&&
.HYDROLOGY...
ISSUED AT 241 PM EDT SUN APR 27 2014
I DOWNPLAYED THE QPF THROUGH TUE. THE DRY AIRMASS CURRENTLY IN
PLACE SHOULD ACT TO DELAY THE ARRIVAL OF THE SHOWERS. MODELS ARE
GENERALLY SHOWING A DIMINISHING TREND TO THE INITIAL BAND OF
SHOWERS DURING THE DAY ON MONDAY. STILL LOOKS LIKE ENOUGH RAIN TO
CAUSE RIVER RISES. ANOTHER BATCH OF RAIN TUE NIGHT INTO WED MAY BE
HEAVY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LMZ844>849.
&&
$$
UPDATE...MJS
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
741 AM EDT MON APR 28 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 325 AM EDT MON APR 28 2014
AN EXPANSIVE AND STRONG SYSTEM CENTERED ACROSS THE CENTRAL PLAINS
STATES WILL DRIVE RAINFALL INTO THE AREA AHEAD OF AN ASSOCIATED
FRONTAL SYSTEM TO OUR SOUTH. COOL AND WINDY CONDITIONS CAN BE
EXPECTED TODAY WITH AN INCREASING CHANCE OF RAIN. RAIN WILL CONTINUE
INTO EARLY TUESDAY BEFORE THE RAIN MOVES NORTH AND A SHORT PERIOD OF
WARMER AIR MOVES IN ACROSS THE AREA. ADDITIONAL SHOWERS AND STORMS
WILL BE POSSIBLE TUESDAY AND WEDNESDAY AS ADDITIONAL WAVES OF LOW
PRESSURE MOVE THROUGH THE AREA. COOLER CONDITIONS WILL THEN RETURN
FOR LATE THIS WEEK ALONG WITH A CONTINUED CHANCE OF RAIN SHOWERS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
THE MAIN CHANGE WITH THIS FCST PACKAGE IS TO EXPAND THE WIND
ADVISORY TO THE EAST THROUGH THE REMAINDER OF THE CWFA FOR TODAY.
OTHERWISE...THE FCST REMAINS MAINLY ON TRACK WITH A SLIGHTLY SLOWER
TREND TO THE RAIN MOVING IN FOR TODAY.
REGARDING THE EXPANSION OF THE WIND ADVISORY FIRST...WINDS REMAIN
RATHER BRISK AND THIS EARLY MORNING HOUR ACROSS THE CWFA. SOME GUSTS
OF AROUND 30 KNOTS ARE ALREADY OCCURRING THIS MORNING...AND THIS
WILL ONLY INCREASE DURING THE DAYLIGHT HOURS AS THE GRADIENT
TIGHTENS MORE AND AS DIURNAL MIXING WILL HELP TO BRING SOME OF THE
STRONGER WINDS DOWN FROM ALOFT. IT SEEMS THAT 40 KNOTS SHOULD BE
PRETTY EASY TO MIX DOWN...EVEN IN A WAA PATTERN.
AS FAR AS THE RAINFALL IS CONCERNED...THE TREND OVER THE PAST 24
HOURS IS THAT OF A SLOWER ONE WITH THE FEED OF DRY AIR COMING IN ON
THE BRISK ERLY WINDS AND HELPING TO DIMINISH MOST ALL PCPN TRYING TO
MOVE IN. THE UPPER RIDGE AXIS THAT IS ONLY SLOWLY CRAWLING EASTWARD
ACROSS THE CWFA IS FAR ENOUGH EAST AT THIS TIME THAT ENOUGH MOISTURE
TRANSPORT IS OCCURRING AND A COUPLE OF SPRINKLES/LIGHT SHOWERS ARE
OCCURRING ACROSS THE FAR SW CORNER OF THE CWFA. WE DO EXPECT THAT
PCPN WILL BE ON THE INCREASE TODAY FROM SW TO NE AS THE UPPER LOW
ROTATES A LITTLE CLOSER. THUNDER IS STILL POSSIBLE ACROSS THE FAR
SOUTH THIS AFTERNOON AS SLIGHTLY NEGATIVE ELEVATED LI/S MOVE UP INTO
THE AREA. SEVERE WX IS NOT EXPECTED AT THIS TIME WITH NO SFC
INSTABILITY EXPECTED THROUGH TONIGHT.
THE BEST THREAT OF RAIN SHOWERS AND STORMS LOOKS TO COME THIS
EVENING AND INTO THE OVERNIGHT HOURS. THE BEST MOISTURE AXIS PASSES
FROM SOUTH TO NORTH DURING THIS TIME FRAME...OUT AHEAD OF THE
OCCLUDED FRONT. WE CONTINUE TO EXPECT LITTLE THREAT OF SEVERE STORMS
TONIGHT ONCE AGAIN AS THE INSTABILITY WILL ONCE AGAIN BE ELEVATED.
THE RAIN CHANCES WILL THEN DIMINISH LATE TONIGHT AND EARLY TUE
MORNING AS THE MOISTURE TRANSPORT AND LLJ PEEL OFF TO THE EAST OF
THE STATE.
WE CONTINUE TO LOOK FOR A BRIEF WARM UP FOR THE DAY ON TUE WITH 70
DEGREE TEMPERATURES LOOKING MORE LIKELY. THE FRONT WILL BE NEAR THE
SRN STATE BORDER AT 12Z ON TUE. THE UPPER LOW COMING IN FROM THE
WEST WILL PUSH THE FRONT NORTH THROUGH THE AREA. EVEN THOUGH IT WILL
NOT BE THE TRUE WARM SECTOR...H850 TEMPS ARE STILL VERY MILD...AND
WILL WE TAP THAT WARMTH AS THE DRY SLOT MOVES IN AND WE GET SOME
SUN. H850 TEMPS AROUND +10 C WILL SUPPORT MANY LOCATIONS HITTING 70.
IT DOES LOOK LIKE LATE IN THE AFTERNOON WE WILL SEE CONVECTION TRY
TO FIRE OVERHEAD AS A WAVE ROTATES AROUND THE UPPER LOW AND MOVES
TOWARD THE AREA.
THERE IS SOME CONCERN WITH CONVECTION FIRING ON TUE AFTERNOON AS
STRONG JET STREAM WINDS WILL STILL BE OVERHEAD ACROSS SE LOWER.
THIS WILL PROVIDE FOR GOOD SHEAR IN THE DEEP LAYER. MUCH BETTER
INSTABILITY /LI/S OF -6 TO -8C/ WILL BE FOUND FURTHER SE ALSO.
WE STAY RELATIVELY WARM THROUGH MOST OF WED AS THE LOW LEVEL COLD
AIR DOES NOT COME IN UNTIL LATE WED AFTERNOON AND WED EVENING. THIS
IS THE CASE AS THE UPPER LOW HELPS ANOTHER WAVE TOWARD THE AREA AND
THE FLOW AHEAD OF IT WILL CONTINUE TO SUPPORT WARM TEMPS UNTIL THE
LOW MOVES THROUGH LATE WED. SHOWERS AND STORMS WILL REMAIN POSSIBLE
AHEAD OF THIS WAVE FOR TUE NIGHT AND WED. WE WILL LIKELY NOT REACH
70 AGAIN...BUT WE SHOULD BE WELL INTO THE 60S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
LITTLE QUESTION OCCASIONAL SHOWERS AND COOLER THAN NORMAL
TEMPERATURES WILL PREVAIL THROUGH SATURDAY AS WE REMAIN ON THE
CYCLONIC SIDE OF THE UPPER JET WITH A FAIR AMOUNT OF DEEP MOISTURE.
SOME QUESTION ARISES WHAT HAPPENS FROM SUNDAY AND BEYOND SO I KEEP
THE LOW CHANCE POP FOR SUNDAY BUT IT MAY BE WE ACTUALLY GET TO SEE
THE SUN ONCE AGAIN BY SUNDAY AS THE UPPER JET MAY FINALLY LIFT NORTH
OF LOWER MICHIGAN MY THEN.
MODEL CONTINUE TO BE IN GOOD AGREEMENT WITH THE CLOSED UPPER LOW
REMAINING IN PLACE INTO AS LEAST SATURDAY. THE 500 MB HEIGHT
ANOMALIES ARE ON THE ORDER OF 2-3 STD BELOW NORMAL INTO SATURDAY
OVER THE LOWER GREAT LAKES. 850 MB TEMPERATURES ARE 1 TO 2 STD BELOW
NORMAL INTO SATURDAY.
THE MODELS CONTINUE TO FEATURE THAT ARCTIC JET STREAK FEEDING INTO
THE SYSTEM FRIDAY INTO SATURDAY. THAT WILL MAINTAIN THIS PATTERN
INTO SATURDAY FOR SURE. FROM SUNDAY ON THERE IS A QUESTION OF
WHETHER ANOTHER PACIFIC SYSTEM CAN BREAK THROUGH THE WESTERN RIDGE
TO PUSH THIS PATTERN OUT OF THE WAY OR IF WE WILL CONTINUE TO SEE
MORE IN A SERIES OF NORTHERN STREAM OF SYSTEMS. I KEEP LOW CHANCE
POPS FOR SUNDAY JUST IN CASE THE LATER OCCURS.
AS FOR THE SHOWERS WEDNESDAY NIGHT THROUGH SATURDAY AFTERNOON...
GIVEN THE DEEP CYCLONIC FLOW...DEEP MOISTURE AND SATURATED DGZ PLUS
SURFACE CONVERGENCE ALONG THE LAKE MICHIGAN SHORE AREAS INTO
SATURDAY I HAVE TO BELIEVE WE WILL CONTINUE TO SEE LIGHT SHOWER
THROUGH THIS ENTIRE PERIOD. I HAVE CONTINUED THE LIKELY POPS INTO
FRIDAY AND HIGH CHANCE INTO SATURDAY. TEMPERATURES WILL BE BETWEEN 5
AND 10 DEGREES BELOW NORMAL THROUGH THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 741 AM EDT MON APR 28 2014
OUR MAJOR QUESTION IS WHEN WILL THE RAIN ARRIVE AND MORE THAN THAT
WHEN WILL THE MVFR/IFR CIGS/VSBY MOVE IN AS THE STORM TO OUR
SOUTHWEST SLOWLY MOVES TOWARD THE REGION. THE HUDSON BAY HIGH
CONTINUES TO FEED VERY DRY AIR FROM THE EAST AND IT WILL CONTINUE
TO ERROD THE RAIN AS MOVES INTO SOUTHWEST MICHIGAN. THIS IS NOT TO
SAY THERE WILL NOT BE SOME LIGHT RAIN SHOWERS BUT IT SEEMS THE
BULK OF THE SIGNIFICANT RAIN WILL LARGELY STAY NEAR AND SOUTH OF
INTERSTATE 94 TODAY (USING THE RAP13 MODEL AND HRRR ).
I DID BRING THE SHOWERS INTO THE AZO...BTL AND JXN BY LATE MORNING
BUT I DID NOT BRING THOSE SHOWERS INTO GRR...MKG AND LAN TILL LATE
AFTERNOON... EVEN THEN VSBY SHOULD BE VFR FOR THE MOST PART. I PUT
VCSH AT ALL THE TAF SITES DURING THE MID MORNING HOURS SINCE
SHOWERS WILL BE AROUND BUT VERY LIGHT (MOSTLY SPRINKLES).
THE MVFR CIGS/VSBY SHOULD REACH THE I-94 TAT SITES BY LATE
AFTERNOON THEN SPREAD INTO THE I-96 SITES AFTER 00Z. ANY
THUNDERSTORM ACTIVITY SHOULD HOLD OFF UNTIL TUESDAY.
&&
.MARINE...
ISSUED AT 325 AM EDT MON APR 28 2014
WE HAVE CONTINUED THE GALE WARNING FOR THE ENTIRE NEARSHORE AND
ADDED 12 HRS TO THE DURATION FOR THIS FCST PACKAGE. COASTAL
OBSERVATIONS INDICATE THAT WINDS ARE ON THE VERGE OF GALE CRITERIA
ALREADY EARLY THIS MORNING. WE EXPECTED TO WIND GUSTS TO CONTINUE
WITH THE FLOW BEING AN OFFSHORE ONE AND DIURNAL MIXING INLAND
HELPING TO INCREASE THE GUSTS AFTER SUNRISE TODAY. STRONGER WINDS
JUST OFF THE SFC WILL REMAIN FOR MOST OF THE NIGHT BEFORE
DIMINISHING ON TUE.
&&
.HYDROLOGY...
ISSUED AT 241 PM EDT SUN APR 27 2014
I DOWNPLAYED THE QPF THROUGH TUE. THE DRY AIRMASS CURRENTLY IN
PLACE SHOULD ACT TO DELAY THE ARRIVAL OF THE SHOWERS. MODELS ARE
GENERALLY SHOWING A DIMINISHING TREND TO THE INITIAL BAND OF
SHOWERS DURING THE DAY ON MONDAY. STILL LOOKS LIKE ENOUGH RAIN TO
CAUSE RIVER RISES. ANOTHER BATCH OF RAIN TUE NIGHT INTO WED MAY BE
HEAVY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...MJS
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
717 AM EDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 511 AM EDT MON APR 28 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH FROM THE NW CONUS THROUGH THE CENTRAL PLAINS WITH A
CLOSED LOW OVER NEBRASKA. DOWNSTREAM A RIDGE EXTENDED FROM THE SE
CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY
FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON
BAY AND A DEEP LOW OVER ERN NEBRASKA. ISENTROPIC ASCENT AS NOTED ON
THE 295K SFC HAS PRODUCED SEVERAL BANDS OF LIGHT PCPN OVER UPPER MI
THIS MORNING BUT THIS PCPN HAS FALLEN MAINLY AS JUST
SPRINKLES/FLURRIES AS IT ENCOUNTERS VERY DRY AIR BELOW 750 MB.
TODAY...MODELS CONSISTENT SHOWING SYSTEM OVER ERN NEBRASKA STALLING
AND BEGINNING TO OCCLUDE TODAY. MODELS SHOW WEAKENING ISENTROPIC
ASCENT OVER UPR MI AND A LACK OF 850-700 MB MOISTURE ADVECTION INTO
THE REGION. THIS FACT ALONG WITH MID-LVL RDG GENERALLY STAYING IN
PLACE SHOULD KEEP MUCH OF THE CWA DRY TODAY. INCREASING 850-700 MB
MOISTURE ADV AND ISENTROPIC ASCENT COULD BRING IN A BETTER CHC OF
RAIN TOWARD 00Z THIS EVENING OVER MAINLY FAR SCNTRL CWA.
TONIGHT...MODELS SHOW MORE SUBSTANTIAL SHORTWAVE LOBE ROTATING
NORTHWARD AHEAD OF PLAINS CLOSED LOW WHICH IN TURN WILL PROPEL 850
MB WARM FRONT NORTHWARD INTO THE SE CWA LATE TONIGHT. INCREASING
ISENTROPIC ASCENT AND 850-700 MB MOISTURE ADVECTION SPREADING IN
FROM THE SSE AHEAD OF THE WARM FRONT WILL BRING INCREASING RAIN CHCS
INTO SCNTRL CWA THIS EVENING SPREADING INTO THE REST OF THE SE HALF
OF THE CWA OVERNIGHT TONIGHT. THICKNESS VALUES AND SOUNDINGS SUGGEST
SNOW MAY MIX WITH RAIN OVER NCNTRL AND NW CWA LATE TONIGHT BUT PCPN
SHOULD BE LIGHT THAT ANY SNOW AMTS WILL HAVE LITTLE IMPACT ON TRAVEL.
MODEL QPF INDICATES SCNTRL CWA COULD SEE FROM .25 TO PERHAPS .75 OF
AN INCH OF RAINFALL TONIGHT WHICH WILL ADD TO RUNOFF FOR AREA STREAMS
AND RIVERS INTO MIDWEEK.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM EDT MON APR 28 2014
FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT
PRECIP IS EXPECTED DURING THAT TIME.
THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A
DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE
W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE
LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER
LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED
UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND
THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE
WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH
IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY
50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN
THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC
SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO
DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR
GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING
MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA
TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM.
ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS
THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT
QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP
SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE
IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT
PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF
NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES.
WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM
/WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT
TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE
MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM
IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME
FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN
UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE
TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS
THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE
MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER
MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS
TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING
ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA
RIVERS.
ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE
SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND
BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND
TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL
BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE
MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE
PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP
DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING
THIS PERIOD.
THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE
WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE
THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT
AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 711 AM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL UNTIL LATE TONIGHT. THERE COULD BE SOME
INTERMITTENT LIGHT RAIN/SPRINKLES AT KIWD THIS MORNING BUT OTHERWISE
MID CLOUDS AND VFR CONDITIONS WILL PREVAIL. INCREASING MOISTURE AHEAD
OF A WARM FRONT WILL BRING INCREASING CHCS OF RAIN LATE TONIGHT AT
ALL TAF SITES AS CIGS LOWER TO MVFR AND POSSIBLY IFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EDT MON APR 28 2014
EAST TO NORTHEAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE
DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER MUCH OF WRN
LAKE SUPERIOR INTO TUE MORNING. THERE IS ALSO A CHANCE FOR ENE GALES
TO 35 KNOTS OVER CENTRAL LAKE SUPERIOR FOR LATE TONIGHT INTO TUE SO
HAVE ISSUED A GALE WATCH FOR LSZ264-266 WINDS SHOULD GRADUALLY
DIMINISH LATE TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE EVENING. WINDS ARE
EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO FRI AS THE
LOW FILLS AND REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 358 AM EDT MON APR 28 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER
NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT
EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL
START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND
WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID
EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY
THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE
WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE
FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER
QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
LSZ264>266.
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ TUESDAY FOR LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...VOSS
MARINE...VOSS
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
633 AM CDT Mon Apr 28 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 152 AM CDT Mon Apr 28 2014
Latest HRRR weakens most of the convection currently across our
forecast area, or shifts it southeast of the region by 12z Monday.
There may be a brief lull in the convection early this morning, then
new convection should break out late this morning and early this
afternoon from Edina to Quincy and south through the St Louis metro
area to the FAM area, then shift eastward through our IL counties
later this afternoon. This will occur as a shortwave ejects out of
the southern Plains into southeast MO and a cold front/dry line
surges eastward into eastern MO by 00z Tue. Should have CAPEs up to
2000-2500 J/Kg ahead of the cold front around 18z Monday with
surface LI values down to around -10. Strongest low-mid level wind
shear should be across southeast MO and southwest IL with strong
500 mb wind max moving through AR into portions of southeast MO,
southern IL, and western portions of TN and KY. The severe weather
threat should be over the eastern portion of our area, in portions
of west central and southwest IL with the primary threat being large
hail and damaging winds. This will occur from the late morning,
through the afternoon and into the early evening hours.
GKS
.LONG TERM: (Tonight through Sunday)
Issued at 341 AM CDT Mon Apr 28 2014
The showers and thunderstorms should be confined to areas east of
the Mississippi River this evening and should be weakening by late
evening as the higher surface dewpoints and instability shifts east
of our forecast area. Little if any precipitation should be left
late tonight. Temperatures will be cooler tonight due to low level
cold air advection in our area south of the upper level and
associated surface low. More showers and a few thunderstorms on
Tuesday as the moisture wraps around the slow moving upper/surface
low north of our area. The best chance for rain will be across the
northwest half of our forecast area. The models keep the showers
going Tuesday night as shortwaves rotate around the mid-upper level
low. The gradual cooling trend will continue with well below normal
temperatures for Wednesday and Wednesday night. The GFS and ECMWF
models drop the zero degree C 850 mb isotherm southeastward into our
forecast area Tuesday night or Wednesday, the cooler NAM even
earlier. Although there will likely be rain across our area again
on Wednesday it should be on the light side. The rain should be
mainly diurnal on Thursday and Friday and favor the northern portion
of our forecast area as the upper level low weakens and moves into
the Great Lakes region. Will see warmer high temperatures for the
weekend as the upper level heights begin to rise and southerly
surface/low level flow returns Saturday night. Low-mid level warm
air advection ahead of a weak shortwave and associated surface low
may bring showers to the extreme northern portion of our forecast
area late Saturday night and Sunday.
GKS
&&
.AVIATION: (For the 12z TAFs through 12z Tuesday Morning)
Issued at 633 AM CDT Mon Apr 28 2014
VFR conditions outside of TSRA will prevail at the TAF sites thru
the valid period. Another round of TSRA is expected to develop
mainly east of the MS river around midday, leaving UIN and the STL
Metro sites on the backedge of what does form. Due to these TAF
sites being on the backedge, have elected to keep VCTS mention
versus TEMPO until we get closer to initiation time. What does
develop should shove off to the northeast by late afternoon. Gusty
southerly winds are expected, diminishing tonight.
Specifics for KSTL: VFR outside of TSRA thru the valid period.
Another round of TSRA is expected to develop over the STL Metro
area around midday with what does form shoving off to the
northeast by mid-afternoon. Due to the terminal anticipated to
being on the backedge, have elected to keep VCTS mention versus
TEMPO until we get closer to initiation time. Gusty southerly
winds are expected, diminishing tonight.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1040 AM EDT MON APR 28 2014
.SYNOPSIS...A STALLED SURFACE BOUNDARY ACROSS CENTRAL NC WILL LIFT
NORTHWARD AS A WARM FRONT THIS AFTERNOON. A WARM...MOIST AND
UNSTABLE AIR MASS WILL RESIDE OVER CENTRAL NC TONIGHT THROUGH
WEDNESDAY NIGHT. A SERIES OF UPPER LEVEL DISTURBANCES WILL INTERACT
WITH THIS AIR MASS TRIGGERING SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM MONDAY...
A WEAK COLD FRONT AND SHALLOW STABLE AIRMASS SETTLED SOUTH THROUGH
THE AREAS OVERNIGHT...MAKING IT ESSENTIALLY TO THE SC BORDER AND
CREATING A RATHER LARGE GRADIENT IN TEMPS AND DEWPOINTS. THE PARENT
SURFACE HIGH BEHIND THE FRONT WILL CONTINUE TO SUPPLY A
NORTHEASTERLY WIND TODAY...BUT WITH CLEARING ALREADY OCCURRING ACROSS
THE SOUTHERN PIEDMONT AND A SOUTHWESTERLY WIND AT 925MB...THE BOUNDARY
SHOULD MIX BACK TO THE NORTH TODAY. HIGHS FOR TODAY ARE TOUGH GIVEN
THE VARYING CLOUD COVER AND SLOWLY VEERING SURFACE WINDS ACROSS THE
SOUTH. TEMPS OVER PORTION OF SC HAVE ALREADY JUMPED INTO THE MID
AND UPPER 70S. ACROSS THE NORTH THE AMOUNT OF SUN IS A BIT MORE
UNCERTAIN...WITH ADDITIONAL CLOUD COVER MOVING EAST ACROSS THE BLUE
RIDGE. ADJUSTMENTS TO TEMP TRENDS YIELDS MID 60S NORTH TO LOWER 80S
SOUTH.
REGARDING CONVECTION... THE MAIN LIMITING FACTOR IS THE SHORTWAVE
RIDGE OVERHEAD...BUT FORECAST SOUNDINGS SUGGEST HEATING AND
MOISTURE RECOVER WILL BE ABLE TO OVERCOME THE MID-LEVEL CAP. THE
LATEST RAP RUNS SHOW AN INSTABILITY AXIS ON THE ORDER OF 500-1000
J/KG MLCAPE NOSING NORTH ACROSS THE SOUTHERN PIEDMONT BY
MIDDAY...WITH DESTABILIZATION TO THE EAST CROSS THE SANDHILLS AND
SOUTHERN COASTAL PLAIN WITH TIME. THE SEEMS TO MESH WELL WITH
SATELLITE TRENDS AND DEWPOINTS RECOVERING INTO THE MID TO UPPER
60S....SO AREAS SOUTH OF HWY 64 LOOK TO MOST FAVORABLE FOR
CONVECTION THIS AFTERNOON. BULK SHEAR WILL BE STRONGER TO THE
NORTH...BUT GUIDANCE SUGGESTS AS MUCH AS 30KT WHICH COULD SUPPORT
SOME MULTICELL CLUSTERS WITH A GENERAL MOTION FROM WEST TO EAST.
THE MAIN THREAT FROM STORMS WILL BE DAMAGING WINDS...THOUGH STORMS
FARTHER NORTH IN THE VICINITY OF THE RETREATING SURFACE BOUNDARY AND
BACKED SURFACE WINDS WILL ENCOUNTER GREATER SHEAR AND HAVE A BETTER
CHANCE OF ROTATING. AGAIN...THE THREAT OF SEVERE WEATHER IS
CONDITIONED UPON DEVELOPMENT OF STORMS...WHICH SHOULD BE MOSTLY
SCATTERED IN NATURE. -SMITH
TONIGHT...SFC FRONT PROJECTED TO BE STALLED ACROSS THE NORTHERN
COUNTIES. WEAK CONVERGENCE ALONG THIS FEATURE WILL MAINTAIN A
THREAT FOR SCATTERED SHOWERS THROUGH THE NIGHT. EXPECT SHOWERS TO BE
MORE ISOLATED ACROSS THE SOUTH. RATHER MILD TONIGHT WITH MIN TEMPS
NO LOWER THAN THE MID 60S ACROSS THE SOUTH...TRENDING TO THE UPPER
50S/NEAR 60 SOUTH.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
TUESDAY AND TUESDAY NIGHT...ACTIVE WEATHER PATTERN APPEARS LIKELY
ACROSS CENTRAL NC WITH A CHANCE FOR MORE THAN ONE ROUND OF STRONG TO
SEVERE STORMS.
THE DEEP LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS/MID MS VALLEY
WILL REMAIN NEARLY STATIONARY THIS PERIOD. A SERIES OF UPPER LEVEL
DISTURBANCES WILL ROTATE AROUND THIS LOW SIMILAR TO SPOKES AROUND
TEH CENTER OF A WHEEL. AS A DISTURBANCE CROSSES CENTRAL NC AND
INTERACTS WITH THE WARM MOIST UNSTABLE AIR MASS IN PLACE...EXPECT
SCATTERED TO NUMEROUS SHOWERS AND STORMS TO OCCUR. BASED ON MODEL
TIMING 9WHICH WILL LIKELY CHANGE OR ADJUST IN LATER MODEL
RUNS)...APPEARS FIRST ROUND OF SHOWERS AND STORMS WILL CROSS THE
REGION TUESDAY AFTERNOON WITH ANOTHER ROUND LATE TUESDAY NIGHT. WIND
PROFILES TUESDAY AFTERNOON ARE SUPPORTIVE OF STRONG UPDRAFTS WITH
LOW LEVEL HELICITY VALUES IN THE 150-300 M2/S2 RANGE LATE TUESDAY
INTO TUESDAY NIGHT. IN ADDITION...STRONG LIFT EXPECTED THROUGH TEH
COLUMN AS CENTRAL NC WILL BE IN THE RIGHT ENTRANCE REGION OF A 100-
110KT UPPER JET. THUS...POTENTIAL FOR A FEW SEVERE STORMS TUESDAY
AFTERNOON AND TUESDAY NIGHT WITH A FEW TORNADOES PROBABLE.
ALSO...POTENTIAL FOR STORMS TO REPEAT ACROSS THE SAME AREA. WITH
PRECIP WATER VALUES 1.5-1.75 INCHES PROJECTED...THIS SUGGEST THAT
THE HEAVY SHOWERS AND STORMS WILL BE CAPABLE FOR PRODUCING HEAVY
RAIN...LEADING TO FLOODING IN URBANIZED AREAS (AND EVENTUALLY SOME
RIVER FLOODING).
MAX TEMPS TUESDAY DEPENDENT UPON WHETHER THE SFC BOUNDARY LIFTS
ENTIRELY INTO VA OR LAGS ALONG OUR NORTHERN COUNTIES. APPEARS TO BE
ENOUGH OF A SLY FETCH JUST ABOVE THE SFC TO PUSH THE BOUNDARY NWD SO
HAVE LEANED TOWARD THE WARMER GUIDANCE FOR TUESDAY. MAX TEMPS MID
70S FAR NORTH-NW TO THE LOWER 80S SOUTH. MIN TEMPS TUESDAY NIGHT LOW
60S FAR NORTH-NW TO MID-UPPER 60S ELSEWHERE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
WEDNESDAY AND WEDNESDAY NIGHT: THE DEEP MID LEVEL LOW AND SURFACE
LOW ARE EXPECTED TO LINGER ACROSS THE UPPER MIDWEST AND GREAT LAKES
REGION ON WEDNESDAY AND WEDNESDAY NIGHT WITH THE SYSTEM QUITE
WRAPPED UP AND OCCLUDED. THIS WILL RESULT IN STRONG SOUTH-
SOUTHWESTERLY MID LEVEL FLOW ACROSS OUR REGION ALONG WITH A SLOW
APPROACHING COLD FRONT. EXPECT THE HEAVIEST AND MORE WIDESPREAD
PRECIP WILL BE ACROSS WESTERN PORTIONS OF THE AREA ON WEDNESDAY.
THIS MAY LEAD TO A DECENT DIFFERENTIAL HEATING BOUNDARY SETTING UP
ACROSS THE REGION. GIVEN DEEP LAYER SHEAR VALUES ARE EXPECTED TO BE
AROUND 35 TO 50 KTS WEDNESDAY AFTERNOON INTO THE EVENING... WITH THE
POTENTIAL FOR UPWARDS OF 1000 TO 2000 J/KG OF MLCAPE FOR LOCATIONS
THAT WARM UP NICELY AND SEE A BIT LESS RAIN... EXPECT WE WILL HAVE A
THREAT FOR SEVERE STORMS. IF WE INDEED SEE A BOUNDARY SET UP OR
LINGERING BOUNDARY FROM EARLIER THEN WE COULD SEE AN INCREASE RISK
FOR TORNADOES... AS 0-1 KM SRH VALUES ARE EXPECTED TO BE IN THE 150
TO 400 M2/S2 RANGE WITH RIGHT LOOPING HODOGRAPHS. GIVEN THE
IMPRESSIVE DEEP LAYER SHEAR AND POSSIBLE MODERATE INSTABILITY...
SUPERCELLS WILL BE POSSIBLE... WITH DAMAGING WIND AND LARGE HAIL AS
WELL. IN ADDITION... WITH PW VALUES EXPECTED TO BE AROUND 1.5 INCHES
(WELL ABOVE NORMAL FOR THIS TIME OF YEAR) EXPECT THE SHOWERS AND
STORMS WILL PRODUCE HEAVY RAIN. THIS COUPLED WITH THE SLOW MOVING
FRONT WILL POSE A RISK FOR FLASH FLOODING AND RIVER FLOODING...
ESPECIALLY ACROSS THE WESTERN PIEDMONT (WHERE SEVERAL DAYS WORTH OF
MODERATE TO HEAVY RAIN MAY LEAD TO 3 TO 4+ INCHES OF RAINFALL). THE
MAIN AXIS OF SHOWERS AND STORMS WILL BEGIN TO SLOWLY SHIFT EASTWARD
BY EARLY THURSDAY MORNING AS THE SURFACE COLD FRONT BEGINS TO PUSH
THROUGH THE AREA... WITH THE MAIN AREAS OF SHOWERS AND STORMS FROM
GENERALLY RALEIGH EASTWARD BY MIDNIGHT THURSDAY.
TEMPS ON WEDNESDAY WILL BE TRICKY AND DRIVEN BY CLOUDS AND PRECIP.
FOR NOW WILL SHOW HIGHS IN THE WEST (WHERE THE MOST RAIN IS
EXPECTED) IN AROUND THE MID 70S (CLOSER TO THE COOL SIDE OF
GUIDANCE) TO THE LOWER 80S SE. LOWS THURSDAY MORNING SHOULD REMAIN
MILD WITH AT LEAST CONTINUED LINGERING LOW LEVEL CLOUD COVER.
THUS... WILL GO WITH LOWS IN THE LOWER 60S WEST TO UPPER 60S EAST.
THURSDAY THROUGH SUNDAY: THE COLD FRONT WILL SLOWLY MOVE ACROSS
CENTRAL NC WEDNESDAY NIGHT/THURSDAY MORNING... WITH A FINAL
SECONDARY PUSH NOT COMING THROUGH UNTIL THURSDAY NIGHT/FRIDAY
MORNING. HOWEVER... WITH MID LEVEL DRY AIR FILTERING INTO THE
WESTERN/NORTHWESTERN HALF OF THE CWA ON THURSDAY EXPECT WE WILL
BEGIN TO DRY OUT A BIT IN PIEDMONT ON THURSDAY INTO THURSDAY NIGHT.
GIVEN THE MID LEVEL TROUGH AXIS IS EXPECTED TO REMAIN TO OUR WEST
UNTIL LATE SATURDAY/SATURDAY NIGHT WITH THE SURFACE FRONT EXPECTED
TO LINGER NEAR THE COAST THROUGH SATURDAY MORNING... EXPECT WE COULD
SEE SOME MORE SHOWERS AND EVEN SOME STORMS... WITH THE HIGHEST
PROBABILITIES ACROSS OUR FAR EAST/SOUTHEASTERN AREAS. DRY WEATHER IS
EXPECTED TO RETURN FOR SUNDAY. EXPECT HIGH TEMPS WILL BE IN THE 70S
TO NEAR 80 EAST ON THURSDAY... WITH HIGH TEMPS GENERALLY AROUND 70
TO THE MID 70S FOR FRIDAY THROUGH SUNDAY. LOW TEMPS WILL BE IN THE
40S AND 50S FOR THIS TIME FRAME.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 140 AM MONDAY...
VFR CONDITIONS EXPECTED TO LINGER THROUGH THE OVERNIGHT INTO EARLY
THIS MORNING AS LOW STRATUS HAS BEEN SLOW TO DEVELOP NE OF OUR
REGION. WILL CONTINUE TO MONITOR BUT THE GFS MODEL MAY BE OVERDONE
IN ITS DEPICTION OF LOW CLOUDS (MVFR/IFR CEILINGS) OVER A LARGE PART
OF CENTRAL NC THROUGH 11Z.
THE APPROACH OF AN UPPER LEVEL DISTURBANCE FROM THE SW AND A STALLED
SURFACE BOUNDARY OVER CENTRAL NC WILL CAUSE AREAS OF SHOWERS TO
DEVELOP BY 13Z IN THE WESTERN AND SOUTHERN PIEDMONT...LIFTING NE
INTO THE COASTAL PLAIN AND NE PIEDMONT BY MID AFTERNOON. THESE
SHOWERS WILL CAUSE PERIODS OF LOW END VFR/HIGH END MVFR CEILINGS AND
VISIBILITY. WHILE BEST INSTABILITY EXPECTED TO RESIDE OVER THE
SOUTHERN PIEDMONT...BEST SHEAR FOR SUSTAINED UPDRAFTS WILL BE
LOCATED FARTHER NORTH NEAR THE VA BORDER. STILL A SLIGHT-SMALL
CHANCE FOR A FEW THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL NC BUT
CONFIDENCE OF THUNDER OCCURRING WITHIN 10 SM OF A TAF SITE LOW AT
THIS TIME. THUS WILL REFRAIN FROM MENTIONING THUNDER IN THE TAF
SITES WITH THE 06Z TAF PACKAGE.
A PERIOD OF UNSETTLED WEATHER IS ANTICIPATED THROUGH EARLY THURSDAY
AS A DEEP LOW PRESSURE SYSTEM TO OUR WEST EDGES SLOWLY EAST THROUGH
MID WEEK. THIS WEATHER SYSTEM WILL SPREAD AREAS OF SHOWERS AND
THUNDERSTORMS (ASSOCIATED MVFR-IFR CONDITIONS) ACROSS CENTRAL NC
TUESDAY THROUGH EARLY THURSDAY. STRONG TO SEVERE STORMS APPEAR
HIGHLY PROBABLE TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT.
IMPROVING AVIATION CONDITIONS ANTICIPATED BY LATE IN THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
636 AM CDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT MON APR 28 2014
CURRENT WATER VAPOR IMAGERY SHOWS THE LOW IN THE MID LEVELS OF THE
ATMOSPHERE SPINNING AWAY RIGHT IN THE MIDDLE OF NEBRASKA...WITH THE
WELL ADVERTISED DRY SLOT ALOFT NOSING UP IN FRONT OF IT AND
ENCOMPASSING MUCH OF OUR FORECAST AREA. THE MOST PRONOUNCED DRYING
ALOFT IS ALONG THE I 29 CORRIDOR CURRENTLY. MODEL CONSENSUS IS GOOD
IN PROGGING THE LOW SLOWLY EASTWARD TOWARD SOUTHEAST IA BY VERY LATE
TONIGHT. THE SURFACE LOW FOLLOWS SUIT...AND IT LOOKS LIKE OUR ENTIRE
FORECAST AREA WILL BE PLACED NORTH OF THE WARM FRONT THROUGH TODAY
AND TONIGHT. THE BEST CHANCES FOR WIDESPREAD BENEFICIAL RAINFALL
TODAY WILL BE BEHIND THE INVERTED TROUGH WHICH WILL BE CONFINED TO
OUR FAR WESTERN ZONES APPROACHING CENTRAL SD. THE REST OF OUR AREA
WILL SEE LESS NUMEROUS SHOWERS AND RAINFALL. BUT THERE IS ENOUGH
ELEVATED INSTABILITY TO POP A THUNDERSTORM OR TWO ALMOST AT ANYTIME
THROUGHOUT THE ENTIRE DAY...ESPECIALLY WHEN A MICROSCALE AREA OF
WARM AIR ADVECTION DECIDES TO MOVE NORTHWARD WHICH THE MODELS CANNOT
HANDLE VERY WELL ON THAT SCALE. INTERESTINGLY...BOTH THE GFS AND GEM
PAINT A BROAD STRIPE OF DECENT QPF THIS AFTERNOON JUST NORTH OF THE
WARM FRONT FROM SIOUX CITY TO STORM LAKE. IN ADDITION...THE PAST FEW
RUNS OF THE HRRR ARE ALSO SHOWING THE POSSIBILITY OF DECENT
CONVECTION IN THOSE AREAS AGAIN DUE TO THE PROXIMITY OF THE WARM
FRONT JUST TO THE SOUTH. AT THIS TIME...IT LOOKS TOO STABLE FOR MUCH
IN THE WAY OF SEVERE WEATHER...AND ALSO THE WIND SHEAR IS NOT REAL
GREAT FROM SIOUX CITY TO STORM LAKE AS THE ENTIRE LOWEST 3
KILOMETERS HAS A WIND DIRECTION OUT OF THE EAST. ONE THING TO WATCH
FOR HOWEVER IS IF A ROGUE SEVERE STORM WHICH BLOWS UP FURTHER TO THE
SOUTHEAST NUDGES INTO THOSE AREAS BEFORE WEAKENING. TO THE
NORTH...KEPT THE COVERAGE OF POPS IN THE SCATTERED CATEGORY THIS
AFTERNOON ALONG THE I 29 CORRIDOR WHERE THE DRY SLOT ALOFT HAS THE
MOST IMPACT. BUT OTHER AREAS MAY START TO FILL IN MORE WITH RAINFALL
IN OUR FAR EAST AND INTO THE JAMES RIVER VALLEY FROM THE WEST AS
MOISTURE PROGS SATURATE UP BETTER ALOFT.
FEEL THERE IS NO NEED FOR A WIND ADVISORY TODAY AS SOUNDINGS ONLY
MIX TO ABOUT 925-900MB AREA WIDE. WINDS IN THAT LAYER ARE STOUT...
AVERAGING 30 TO 35 KNOTS...BUT USUALLY IT TAKES A LITTLE MORE THAN
THAT TO WARRANT A WIND ADVISORY IN OUR AREA...CLOSER TO 40 KNOTS.
HOWEVER TONIGHT ON THE BACK SIDE OF THE LOW...OUR FAR SOUTHWEST
ZONES MAY GET CLOSE TO ADVISORY CRITERIA AFTER MIDNIGHT. MUCH OF OUR
FORECAST AREA TONIGHT IS WELL PLACED IN THE UPPER LEFT QUADRANT OF
THE LOW TRACK TO RECEIVE PRECIP. THERE IS EVEN SOME WEAK TROWALING
IN THE 290-295K LAYER NUDGING INTO OUR AREA FROM THE EAST...AND
SATURATION LOOKS TO BE IN NO SHORT SUPPLY FROM THE SURFACE TO AROUND
500MB. IN THE EVENING...AGAIN THE I 29 CORRIDOR MAY NOT RECEIVE MUCH
RAIN...BUT PRECIP WILL FILL INTO THAT AREA OVERNIGHT. CONCERNING
TEMPERATURES...WITH A FEW BREAKS POSSIBLE NEAR THE WARM FRONT...
AREAS FROM YANKTON TO STORM LAKE AND SOUTHWARD SHOULD HIT 60 TO
65...PROGRESSIVELY COOLING OFF HEADING NORTHWARD. TONIGHT IS
TRICKY...AND HAD TO ADD IN A SNOW MIX TO OUR NORTHERN AND WESTERN
ZONES AS SURFACE TEMPERATURES COOL INTO THE MID 30S IN THOSE AREAS
COUPLED WITH SUB ZERO 850MB TEMPERATURES. USED THE MODEL CONSENSUS
850MB -2 DEGREE C AND 925MB ZERO DEGREE C ISOTHERMS FOR THE RAIN AND
SNOW LINES...COUPLED WITH TEMPERATURES NEAR 35.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM CDT MON APR 28 2014
TUESDAY WILL START FAIRLY RAINY OVER THE AREA...THOUGH AMOUNTS
SHOULD BE LESS THAN A QUARTER INCH FOR THE DAY. DRYING WILL BEGIN
FROM THE NORTH/NORTHEAST DURING THE AFTERNOON OVER THE WESTERN PART
OF THE FORECAST AREA AS SOME SUBSIDENCE SPREADS IN FROM THE NORTH/
NORTHEAST BETWEEN LOBES ROTATING AROUND THE UPPER LOW TO THE EAST.
FOR NOW WILL KEEP SOME VERY MINIMAL POPS IN THE WEST FOR TUESDAY
NIGHT...WHILE ONLY SHAVING POPS TO LOW LIKELIES ALONG OUR EASTERN
EDGE IN MN AND IA. FOR NOW AM GOING FOR ALL OF THIS PRECIPITATION TO
BE LIGHT RAIN EXCEPT MAYBE SOME MODERATE RAIN LINGERING TUESDAY
MORNING IN THE EAST...MAYBE WITH A BIT OF WET SNOW MIXED IN WEST AND
NORTH EARLY MORNING BUT NO ACCUMULATION. FOR TUESDAY NIGHT...THOUGH
TEMPERATURES ALOFT WILL BE MARGINAL FOR A LITTLE MIXED SNOW AGAIN...
THERE MAY BE NO PRECIPITATION AT ALL IN THE WEST WHICH WOULD HAVE
THE BETTER SHOT AT SOME SNOW. SURFACE AND NEAR SURFACE TEMPERATURES
WILL LIKELY BE A BIT TOO WARM WITH THE LIGHTER NATURE OF
PRECIPITATION...IF THERE IS ANY AROUND IN THE FIRST PLACE...AND
DYNAMIC COOLING WILL BE NIL. TO THE EAST...THE DEEPER MOIST AIR
SHOULD PRECLUDE ENOUGH COOLING TO GET SNOW TO THE SURFACE...AND EVEN
THERE THE PRECIPITATION SHOULD BE PRETTY LIGHT. TEMPERATURES WILL
NOT BE SHOWING A LOT OF SPREAD WITH 40S HIGHS AND 30S LOWS. IT WILL
STILL BE WINDY TUESDAY BUT EXPECT WINDS WILL STAY BELOW ADVISORY
CRITERIA.
WEDNESDAY WILL BRING THE NEXT LOBE ROTATING OVER THE AREA AND A
RESURGENCE OF LIGHT RAIN WEST/SOUTHWESTWARD AGAIN. TEMPERATURES
AGAIN WILL CLIMB INTO THE 40S AND IT WILL BE WINDY AGAIN. IT COULD
EVEN BE SLIGHTLY WINDIER THAN TUESDAY WITH THE LOBE PASSING OVER THE
AREA.
THURSDAY WILL BRING THE SYSTEM STARTING TO MOVE SLOWLY EAST OF THE
AREA AND WILL KEEP LIGHT RAIN POPS IN THE CHANCE CATEGORY. WEDNESDAY
NIGHT LOWS SHOULD BE IN THE 30S AGAIN...THOUGH IT MAY BE A DEGREE OR
TWO LESS COOL THERE WITH MODELS HINTING AT VERY SLIGHT LOW LEVEL
WARMING. WITH LESSER PRECIPITATION COVERAGE...THURSDAY DAY
TEMPERATURES ARE EXPECTED TO BE A TAD LESS COOL...UPPER 40S TO LOWER
50S FOR HIGHS. THIS PROCESS WILL CONTINUE ON FRIDAY...REMEMBER THE
SLOWNESS OF THIS SYSTEM...BUT POPS WILL BE PRETTY LOW WITH
PRECIPITATION CONFINED MAINLY TO EAST OF FSD. 50 TO 55 LOOKS RIGHT
FOR HIGHS FRIDAY.
THE WEEKEND SHOULD BE A LITTLE WARMER YET...BUT STILL BELOW
NORMAL...AHEAD OF A CANADIAN WAVE APPROACHING IN NORTHWEST FLOW
BEHIND THE CURRENT SYSTEM. WILL GO WITH THE EXTENDED GUIDANCE GRIDS
OF SHOWER CHANCE PEAKING ABOUT SATURDAY NIGHT. THIS SEEMS TO BE THE
BEST PLAN FOR NOW ON EITHER THE GFS OR EC SOLUTION. THE EC HAS
STRONGER RIDGING BETWEEN SYSTEMS THAN THE GFS AND WOULD BRING
TEMPERATURES A LITTLE CLOSER TO NORMAL FOR THE WEEKEND...BUT THE
LIGHT SHOWER THREAT IS STILL THERE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM CDT MON APR 28 2014
IT APPEARS WIDESPREAD LIFR TO IFR CONDITIONS WILL BE PERSISTENT
ACROSS THE SIOUX FALLS FORECAST AREA BOTH TODAY AND TONIGHT. IN
ADDITION AS STRONG LOW PRESSURE NUDGES VERY SLOWLY EASTWARD...
WINDS WILL OCCASIONALLY GUST AROUND 25 TO 30 KNOTS AT TIMES BOTH
TODAY AND TONIGHT...AS THE OVERALL FLOW BENDS FROM THE EAST TO THE
NORTH TONIGHT. IN THE NEAR TERM...KSUX IS THE MOST CHALLENGING
SITE IN THAT CLEARING WITH VFR CONDITIONS IS NOT TOO FAR AWAY TO
THEIR SOUTHWEST. HOWEVER...THE WIND PROFILE ALL THE WAY FROM THE
SURFACE TO 500MB IS DECIDEDLY EASTWARD ALL DAY TODAY. SO THEREFORE
IT APPEARS THAT THE CLEARING MAY NEVER MAKE IT INTO KSUX...SO TOOK
THE PESSIMISTIC ROUTE FOR THEM.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1058 AM CDT MON APR 28 2014
.DISCUSSION...
ADDED CLIMATE SECTION.
&&
.CLIMATE...
HIGH TEMPERATURES TODAY WILL LIKELY REACH 90 DEGREES. THE LAST
TIME THE CITY OF HOUSTON (KIAH) REACH 90 DEGREES WAS OCTOBER 5TH
OF LAST YEAR (93). THE LAST TIME COLLEGE STATION (CLL) REACHED 90
DEGREES WAS OCTOBER 1ST OF LAST YEAR (91). HERE ARE THE RECORDS
FOR THE THREE FIRST ORDER CLIMATE SITES FOR TODAY WITH THEIR
FORECASTED HIGHS TO THE FAR RIGHT:
CLL (COLLEGE STATION) : 94 (1987) || 91
IAH (CITY OF HOUSTON) : 95 (1987) || 92
GLS (CITY OF GALVESTON):87 (1987) || 84
&&
.PREV DISCUSSION... /ISSUED 1038 AM CDT MON APR 28 2014/
UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
DISCUSSION...
PRECIP HAS COME TO AN END ACROSS MOST OF THE AREA THIS MORNING AS
DRIER AIR WORKS ITS WAY IN FROM THE WEST. HRRR SHOWS A CELL OR TWO
TRYING TO DEVELOP IN CHAMBERS COUNTY AS THE DRY LINE STALLS NEAR
THE COAST THIS AFTERNOON. THE TORNADO WATCH FOR THE AREA WILL BE
ALLOWED TO CONTINUE UNTIL 17Z.
BEHIND THE DRY LINE LIGHT NORTHWEST WINDS... LITTLE CLOUD COVER
AND DRY AIR WILL HELP THE AREA TO QUICKLY HEAT UP. CURRENT AMDAR
SOUNDING FOR HOUSTON SUPPORTS TEMPERATURES IN THE LOWER 90S. MOST
OF THE AREA IS ALREADY AT OR SLIGHTLY ABOVE 80. 90 DEGREES LOOKS
POSSIBLE FOR MOST SITES ACROSS THE AREA (MINUS NORTHEAST COUNTIES
AND AT THE COAST). NUDGED MAX TEMPERATURE GRID UP SLIGHTLY FOR
THIS AFTERNOON. ALSO TRIMMED POPS BACK AS THE CHANCE FOR
CONVECTION APPEARS TO BE COMING TO AN END. NO OTHER CHANGES TO
GRIDS AT THIS TIME. 23
PREV DISCUSSION... /ISSUED 421 AM CDT MON APR 28 2014/
DISCUSSION...
BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC
TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE
TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE
SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/
THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO
HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB
IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT
TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE
UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A
GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST
BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS
INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW
FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN.
SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE
PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY
TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS
SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS.
THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD
UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE
PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD
KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN
THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS
QUITE DRY THRU THE 1ST WEEK OF MAY. 47
MARINE...
WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION
FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS.
GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF
THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE
COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO-
NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN
WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY
FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE
FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41
AVIATION...
HAVING TO KEEP AN EYE ON DEVELOPMENT OUT TO OUR W/NW THRU THE MORN-
ING HOURS. PROBABLY CANNOT AVOID THE MENTION OF THUNDER IN THE NRN
HALF TAF SITES (CLL/UTS/CXO/IAH) THIS MORNING UNTIL THIS AFTN. THE
APPROACH/PASSAGE OF THE PACIFIC FRONT (IN WHICH THIS PCPN IS FOCUS-
ING ON) SHOULD BRING DRIER AIR AND VFR CONDITIONS TO THE AREA LATE
THIS AFTN/TONIGHT. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 59 82 51 75 / 10 10 10 0 0
HOUSTON (IAH) 92 62 86 55 78 / 20 10 10 0 0
GALVESTON (GLS) 84 71 84 62 77 / 20 10 20 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 2 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION/CLIMATE...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1038 AM CDT MON APR 28 2014
.UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
&&
.DISCUSSION...
PRECIP HAS COME TO AN END ACROSS MOST OF THE AREA THIS MORNING AS
DRIER AIR WORKS ITS WAY IN FROM THE WEST. HRRR SHOWS A CELL OR TWO
TRYING TO DEVELOP IN CHAMBERS COUNTY AS THE DRY LINE STALLS NEAR
THE COAST THIS AFTERNOON. THE TORNADO WATCH FOR THE AREA WILL BE
ALLOWED TO CONTINUE UNTIL 17Z.
BEHIND THE DRY LINE LIGHT NORTHWEST WINDS... LITTLE CLOUD COVER
AND DRY AIR WILL HELP THE AREA TO QUICKLY HEAT UP. CURRENT AMDAR
SOUNDING FOR HOUSTON SUPPORTS TEMPERATURES IN THE LOWER 90S. MOST
OF THE AREA IS ALREADY AT OR SLIGHTLY ABOVE 80. 90 DEGREES LOOKS
POSSIBLE FOR MOST SITES ACROSS THE AREA (MINUS NORTHEAST COUNTIES
AND AT THE COAST). NUDGED MAX TEMPERATURE GRID UP SLIGHTLY FOR
THIS AFTERNOON. ALSO TRIMMED POPS BACK AS THE CHANCE FOR
CONVECTION APPEARS TO BE COMING TO AN END. NO OTHER CHANGES TO
GRIDS AT THIS TIME. 23
&&
.PREV DISCUSSION... /ISSUED 421 AM CDT MON APR 28 2014/
DISCUSSION...
BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC
TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE
TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE
SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/
THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO
HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB
IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT
TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE
UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A
GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST
BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS
INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW
FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN.
SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE
PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY
TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS
SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS.
THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD
UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE
PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD
KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN
THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS
QUITE DRY THRU THE 1ST WEEK OF MAY. 47
MARINE...
WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION
FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS.
GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF
THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE
COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO-
NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN
WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY
FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE
FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41
AVIATION...
HAVING TO KEEP AN EYE ON DEVELOPMENT OUT TO OUR W/NW THRU THE MORN-
ING HOURS. PROBABLY CANNOT AVOID THE MENTION OF THUNDER IN THE NRN
HALF TAF SITES (CLL/UTS/CXO/IAH) THIS MORNING UNTIL THIS AFTN. THE
APPROACH/PASSAGE OF THE PACIFIC FRONT (IN WHICH THIS PCPN IS FOCUS-
ING ON) SHOULD BRING DRIER AIR AND VFR CONDITIONS TO THE AREA LATE
THIS AFTN/TONIGHT. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 59 82 51 75 / 10 10 10 0 0
HOUSTON (IAH) 92 62 86 55 78 / 20 10 10 0 0
GALVESTON (GLS) 84 71 84 62 77 / 20 10 20 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 2 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...23
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
635 AM CDT MON APR 28 2014
.DISCUSSION...SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...LOW CIGS/VSBYS RAPIDLY LIFTING AS WINDS HAVE SHIFTED.
WILL LIKELY JUST HAVE SOME TEMPO CONDITIONS ENDING BY NO LATER
THAN 14Z EASTERN TERMINALS. SHOULD MAINLY HAVE N-NW WINDS
ESPECIALLY BY 14Z WITH MAINLY CLEAR SKIES. SEA-BREEZE COMES IN
AGAIN LATE THIS AFTERNOON AND SHIFT WINDS SOUTHERLY STARTING ABOUT
20Z AT KCRP AND SPREADING WESTWARD. WINDS DIMINISH TONIGHT AND
MAINLY BECOME LIGHT AND VARIABLE OVERNIGHT. COULD HAVE SOME GROUND
FOG KCRP AND KVCT TOWARD END OF TAF PERIOD AS LIGHT WINDS AND
CLEAR SKIES CREATE FOG.
&&
.PREV DISCUSSION... /ISSUED 326 AM CDT MON APR 28 2014/
SHORT TERM (TODAY THROUGH TUESDAY)...WARM AND DRY TODAY AND TUESDAY
TOO (MOST AREAS)...AS COLD AIR IS EXPECTED TO LAG BEHIND THE FRONTAL
BOUNDARY ON TUESDAY. LOOKS LIKE ANOTHER HOT DAY...BUT NOT AS HOT AS
YESTERDAY AT LEAST OUT TO THE WEST AS BOUNDARY LAYER TEMPERATURES
ARE PROGGED TO BE SEVERAL DEGREES COOLER (SO IF THAT HAPPENS IT
SHOULD BE COOLER). 4KM RUC IS SHOWING TEMPERATURES TOPPING 100
DEGREE BARRIER OVER THE SOUTHERN AREAS...AND WILL GO 101/102 OVER
THE SOUTHWESTERN AREAS. OTHERWISE...MORNING LOW CLOUDS OVER THE EAST
WILL QUICKLY LIFT AND SHOULD SEE LOTS OF SUN WITH NORTHWEST WINDS AS
DRY LINE MOVES FARTHER EAST THAN YESTERDAY. LOW LEVEL MOISTURE IS
TOO SCOURED OUT FOR ANY MENTION OF RAIN (EVEN OFFSHORE) SO HAVE
REMOVED (4KM MODELS KEEP THINGS DRY TOO). FOR TONIGHT...ONLY NAM IS
BRINGING COOLER AIR MUCH FASTER THAN GFS/ECMWF (ALTHOUGH CANADIAN IS
COOL TOO...AS USUAL). AM GOING TO PREFER TO GO MORE ON THE WARM SIDE
TONIGHT ALTHOUGH IF WINDS ARE TOO LIGHT AND SURFACE MOISTURE IS TOO
LOW...WE COULD REALLY BOTTOM OUT (GIVEN WARM DAY EXPECTED TODAY WILL
PREFER TO STAY ON THE WARM SIDE THOUGH). COOLER AGAIN ON TUESDAY BUT
STILL WARMER THAN NORMAL WITH COLD AIR LAGGING ON FRONT. MAY SEE A
FEW 80S IN THE VICTORIA AREA. MOISTURE AGAIN TOO LIMITED FOR
PRECIPITATION.
MARINE (TODAY THROUGH TUESDAY)...HAVE EXTENDED THE SCA TIL 4 AM FOR
THE BAYS/WATERWAYS...AND LONGER FOR THE GULF WATERS. MAY NEED TO
EXTEND AGAIN AT THE LAST MINUTE IF WINDS STAY UP AGAIN. WINDS HAVE
STAYED UP LONGER THAN EXPECTED WITH GUSTS OVER 30 KNOTS AT KNGP.
4KM RUC HAS WINDS CRANKING TIL 12Z OR SO...BUT THIS IS NORMALLY ON
THE HIGH SIDE (BUT STILL DOING BETTER THAN NAM12 OR OTHER MODELS).
WINDS DO DECREASE BY SUNRISE...BUT SEAS STAY UP. THUS...THE GULF
WATER SCA WILL MAINLY BE FOR HIGH SEAS MONDAY...WITH SCA
CONDITIONS ENDING AROUND NOON. VISIBILITIES OVER THE MARINE AREAS
ARE BETWEEN 1 AND 3 MILES...AND THAT SHOULD CLEAR UP LATER THIS
MORNING. MORE FOG TONIGHT BUT THAT SHOULD BE OVER THE OFFSHORE
WATERS (IF THAT)...AS DRIER AIR DOES GET INTO THE NEARSHORE
WATERS. COULD NOT RULE OUT A ROGUE SHOWER NEAR MATAGORDA ISLAND
BUT THAT WILL BE VERY BRIEF AND UNLIKELY TO HAPPEN (SO NOT IN
FORECAST).
FIRE WEATHER (TODAY THROUGH TUESDAY)...FIRE WEATHER PROCEDURE IS
SHOWING ELEVATED CONDITIONS/ISOLATED CRITICAL OVER MUCH OF THE AREA
ON TUESDAY. FUEL DRYNESS FORECAST MAP IS SHOWING MOST AREAS IN
NORMAL MOISTURE..WITH ONLY A PART OF THE NORTHERN COASTAL BEND (LIVE
OAK AND PORTIONS OF BEE AND MCMULLEN COUNTIES) IN DRY FUELS. SINCE
THESE COUNTIES ARE FORECAST TO BE IN ELEVATED CONDITIONS ON
TUESDAY...NO NEED FOR FIRE WEATHER WATCH OR RED FLAG WARNING. DAY
SHIFT OR NEXT MID SHIFT CAN RE-EVALUATE...ESPECIALLY IF FUEL DRYNESS
MAP CHANGES THE NEXT DAY.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...PERIOD BEGINS WITH
COOLER TEMPERATURES AND DRY CONDITION IN WAKE OF TUESDAY/S/S FROPA.
BROAD LONGWAVE TROUGH CENTERED OVER THE FAR NORTH CENTRAL STATES
WILL KEEP FAIRLY ZONAL FLOW OVER SOUTH TEXAS THROUGH THURSDAY.
TROUGH WILL FINALLY SWING OVER THE REGION THURSDAY NIGHT INTO
FRIDAY. ECMWF CONTINUES TO BE THE WETTER SOLUTION WITH THIS PASSING
WHILE THE GFS/NAM STAY MOSTLY DRY OVERLAND. WHILE THERE IS THE UPPER
LEVEL SUPPORT FOR PERHAPS SOME SPRINKLES AND RAIN TO DEVELOP THERE IS
AN OVERALL LACK OF SUFFICIENT MOISTURE OVER MOST OF THE REGION
EXCEPT IN THE OVER THE OFFSHORE WATERS THURSDAY NIGHT INTO FRIDAY
MORNING. KEPT THE 20 POPS MENTION OVER THE OFFSHORE WATERS FOR
NOW...BUT EVEN THIS MAY BE GOING TOO HIGH. OTHERWISE EXPECT A
CONTINUED DRY FORECAST. TEMPERATURES WILL BE NICELY COOLER (BELOW
AVERAGE) THROUGH THE END OF THE WEEK BEFORE RETURNING TO NORMAL ON
BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 99 66 93 61 80 / 10 0 10 10 10
VICTORIA 93 63 88 55 81 / 10 0 10 10 10
LAREDO 104 69 98 62 86 / 0 0 10 10 10
ALICE 102 64 96 57 83 / 10 0 10 10 10
ROCKPORT 92 67 89 62 79 / 10 0 10 10 10
COTULLA 98 63 92 54 83 / 0 0 0 10 10
KINGSVILLE 102 65 97 60 81 / 10 0 10 10 10
NAVY CORPUS 90 67 87 65 79 / 10 0 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
711 AM EDT MON APR 28 2014
.SYNOPSIS...
A WEAK STATIONARY FRONT WILL REMAIN JUST SOUTH AND WEST OF THE
REGION TODAY INTO TUESDAY. A LARGE AND COMPLEX STORM SYSTEM
LOCATED OVER THE CENTRAL UNITED STATES WILL SLOWLY MOVE EAST. THIS
SYSTEM WILL PROVIDE RAINFALL FOR MUCH OF THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 AM EDT MONDAY...
WEAK BACKDOOR TYPE COLD FRONT NOW HEADING INTO THE SW PORTIONS OF
THE CWA WITH A STIFF EASTERLY FLOW DEVELOPING ESPCLY EAST OF THE
BLUE RIDGE WHERE BEST COOL ADVECTION WILL TAKE SHAPE THIS MORNING.
INIT MID LEVEL WAVE EJECTING OUT INTO THE SHORTWAVE RIDGING ALOFT
LIKELY TO HELP MOISTEN THE COLUMN EARLY ON WITH MAINLY JUST SPOTTY
-RA OR SPRINKLES INTO MID MORNING PER LATEST RADAR TRENDS. MAIN
SHOT AT MORE WIDESPREAD RAINFALL LOOKS TO COME FROM LATE MORNING
INTO MID AFTERNOON AS ANOTHER WAVE SLIDES BY TO THE NW AND HELPS
UPWARD MOTION SWING ACROSS THE NORTH UNDER A CORE OF SLIGHTLY
HIGHER 85H WINDS. MOST GUIDANCE ON TRACK WITH THIS FEATURE WITH
THE LATEST HRRR EXPANDING THIS AXIS EAST TO ALONG THE BLUE RIDGE
AROUND MIDDAY BEFORE TAKING IT TO THE EAST DURING THE AFTERNOON
ALONG THE GRADIENT OF THE THETA-E AXIS ALOFT. THUS HAVE INCLUDED
SOME CHANCE POPS MAINLY WEST EARLY THIS MORNING...THEN A PERIOD OF
LIKELYS FROM WEST TO EAST THROUGH LATE AFTERNOON WHEN SEE BEST
OVERRUNNING. HOWEVER QPF DOESNT LOOK TOO IMPRESSIVE WITH THIS
FEATURE WITH A TENTH TO A QUARTER INCH POSSIBLE WITH ANY THUNDER
FAR WEST AWAY FROM THE DEVELOPING EASTERN WEDGE. HIGH TEMPS REMAIN
TRICKY AS COULD SEE AREAS ACROSS THE NE ONLY RISE A FEW DEGREES
WHILE JUMPING ABOVE 70 ALONG THE I-77 CORRIDOR. WENT CLOSER TO THE
COLDER MET MOS ALONG/EAST OF THE BLUE RIDGE AND A BLEND OUT WEST.
IMPULSE EXITS BY THIS EVENING LEAVING MOST OF THE REGION IN A
STRONG WEDGE WITH ABSENCE OF MUCH LIFT WITH A BAND OF DEEPER
CONVECTION APPROACHING THE MOUNTAINS FROM THE WEST LATE. HOWEVER
SOUNDINGS SHOW A RATHER DEEP EAST/SE LOW LEVEL FLOW UNDER VEERING
ALOFT WHICH WOULD SUPPORT AT LEAST SPOTTY -RA/DZ OUTSIDE THE FAR
WEST WITH ADDED UPSLOPE LIKELY ENHANCING COVERAGE EASTERN SLOPES
OF THE BLUE RIDGE. WEAKENING SHRA/TSRA HEADED IN FROM THE WEST
AROUND DAYBREAK COULD REACH THE WESTERN SLOPES SO KEPT IN SOME
THUNDER MENTION ON THE PERIMETER OF THE WEDGE FOR NOW OVERNIGHT.
OTRW CLOUDY AND DAMP WITH PERIODS OF -RA/DZ AND PERHAPS A FEW MORE
-SHRA SW AS DEEPER WARM ADVECTION SPREADS NORTH ALOFT LATE. KEPT
LOWS CLOSER TO THE COOLER MET MOS AGAIN IN EXPECTING A STRONGER
WEDGE IN THE WAKE OF EARLIER RAINFALL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT MONDAY...
DEEP UPPER CLOSED LOW OVER IOWA AND THE UPPER RIDGE ALONG THE EAST
COAST WILL MOVE EAST DURING THE PERIOD. THE MAIN LOW MOVES EAST
ACROSS THE GREAT LAKES WHILE A WAVE OF LOW PRESSURE ALONG THE
FRONTAL BOUNDARY WILL TRACK TOWARD THE MISSISSIPPI RIVER BY TUESDAY
EVENING.
PLENTY OF MOISTURE IS TRANSPORTED INTO THE REGION FROM THE ATLANTIC
OCEAN AT LOWEST LEVELS AND FROM THE GULF OF MEXICO THROUGH A DEEP
LAYER FARTHER ALOFT. HIGH TEMPERATURES ON TUESDAY ARE TRICKY
DEPENDING SUNSHINE AND AMOUNT OF RAIN. PLAYED HIGHS TOWARDS THE
COOLER ADJMET WITH VALUES FROM THE UPPER 50S ACROSS THE NORTH TO THE
LOWER 70S ACROSS THE SOUTH. THE SWODY2 HAS A FEW SOUTHEAST COUNTIES
IN THE SLIGHT RISK FOR SEVERE THUNDERSTORMS. APPEARS THAT THEY ARE
ALLOWING THE WEDGE TO WEAKEN ON THE SOUTHERN END FOR A FEW HOURS.
WITH THE STRENGHT OF THE WEDGE...GENERALLY UNDERDONE ON THE
MODELS...QUESTIONS ON WHETHER THE WEDGE MIXES OUT FOR A FEW HOURS
TUESDAY AFTERNOON.
BEST Q-V FORCING AND UPPER DIFFLUENCE IN THE RIGHT REAR QUADRANT OF
THE UPPER JET WILL BE TUESDAY NIGHT AND WEDNESDAY. PRECIPITABLE
WATER VALUES RISE TO AS HIGH AS 1.6 INCHES ACROSS THE SOUTHERN AND
EASTERN COUNTY WARNING AREA TUESDAY...WHICH IS AROUND TWO STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. KEPT THE HIGHEST QPF
IN THE TUESDAY NIGHT TO WEDNESDAY TIME FRAME...SIMILAR TO WPC
GUIDANCE. HPC HAS PLACED EXCESSIVE RAINFALL POTENTIAL FOR DAY 2-3
ALONG AND EAST OF THE BLUE RIDGE. HOWEVER WILL HOLD OFF ON A FLOOD
WATCH FOR NOW GIVEN INTERVALS OF HEAVY RAIN AND WHERE EXCESSIVE
MAY OCCUR BASED ON RAINFALL THROUGH MONDAY NIGHT. THUS WILL
MENTION FLOODING POTENTIAL IN THE HWO FOR TUESDAY INTO WEDNESDAY.
CLOUDS MAY HOLD UP LOW TEMPERATURES TUESDAY NIGHT. PLAYED OVERNIGHT
LOW TEMPERATURES FOR THE LOWER 50S IN THE NORTHERN MOUNTAINS TO THE
LOWER 60S IN THE PIEDMONT.
WEDNESDAY LOOKS MORE UNSTABLE WITH LIS AROUND MINUS 5 AND CAPES
POTENTIALLY EXCEEDING 2000 J/KG. INCREASED THE COVERAGE OF
THUNDERSTORMS WEDNESDAY. THE SWODY3 HAS MUCH OF THE CWA IN THE
SLIGHT RISK AHEAD OF THE COLD FRONT. THE MAIN THREAT WILL BE
DAMAGING WINDS. HIGH TEMPERATURES ON WEDNESDAY WILL BE WARMER THAN
TUESDAY WITH READINGS FROM THE UPPER 60S IN THE MOUNTAINS TO THE MID
70S IN THE PIEDMONT. TAPER POPS OFF WEDNESDAY NIGHT INTO THURSDAY.
LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE THE MID 40S IN THE
MOUNTAINS TO AROUND 60 DEGREES IN THE PIEDMONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...
ON THURSDAY...THE CLOSED UPPER LOW WILL BE OVER THE GREAT LAKES
WITH THE LARGE TROF COVERING MUCH OF THE CENTRAL AND EASTERN
UNITED STATES. THE PATTERN REMAINS AMPLIFIED THROUGH SATURDAY BUT
THE REX BLOCK WEAKENS...THE LOW OPENS UP AND THE TROF GRADUALLY
MOVES EAST BY SATURDAY. A SHORT WAVE TRACKING THROUGH THE BASE OF
THE UPPER TROF WILL MOVE ACROSS THE TENNESSEE VALLEY ON SATURDAY.
A STRONGER SHORT WAVE MOVES INTO THE TROF AXIS FROM SOUTHERN
CANADA AND CLOSES OFF OVER THE UPPER MISSISSIPPI VALLEY ON SUNDAY.
ECMWF WAS SHOWING A WAVE ALONG THE SURFACE FRONT WHICH WILL
LIKELY SLOW THE PASSAGE OF THE BOUNDARY ACROSS THE AREA ON
WEDNESDAY NIGHT AND THURSDAY. THE FRONT SHOULD BE WELL OFF THE
SOUTHEAST COAST ON FRIDAY. FRIDAY NIGHT THROUGH SUNDAY HIGH
PRESSURE IS BUILDING OVER THE GULF OF MEXICO AND THE SOUTHEAST
UNITED STATES.
MODELS STILL BRING UNSEASONABLY COLD AIR INTO THE AREA BEHIND THIS
SYSTEM ON THURSDAY NIGHT AND FRIDAY. SUNDAY MORNING HAS THE
POTENTIAL TO REACH WELL INTO THE 30S FOR LOWS IN THE MOUNTAINS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 650 AM EDT MONDAY...
INCREASINGLY MOIST EASTERLY FLOW WILL CONTINUE TODAY WITH THE
CURRENT VFR CIGS/VSBYS DETERIORATING TOWARD MVFR ESPCLY ALONG THE
BLUE RIDGE AND POINTS EAST THROUGH LATE MORNING. DEEPER MOISTURE
ADVECTION SHOULD PRODUCE EVEN LOWER CIGS AND INCREASING
PRECIPITATION CHANCES AGAIN BY AFTERNOON WITH A LOBE OF SHOWERS
PROGGED TO MOVE EAST THROUGH THE AREA AHEAD OF ANOTHER MID LEVEL
WAVE ALOFT...WITH EVEN SOME CHANCE FOR THUNDER BUT MUCH BETTER
CHANCES TO OUR SOUTH AND WEST THIS AFTERNOON. LATEST GUIDANCE
SUGGESTS THAT ONCE THE INITIAL PATCHY RAINFALL EXITS AND THE WEDGE
BECOMES BETTER ENHANCED WILL SEE FLYING CONDITIONS QUICKLY WORSEN
THIS AFTERNOON WITH STRATUS/FOG DEVELOPING IN MANY LOCATIONS
MAKING FOR WIDESPREAD MVFR TO IFR FOR ALL SITES WITH LIFR POSSIBLE
ESPCLY AROUND BCB/ROA TO THE EAST. THIS MAY ACTUALLY OCCUR WITH
LACK OF PRECIP THIS EVENING AS THE MAIN BATCH OF CONVECTION AHEAD
OF THE FRONT ALOFT REMAINS OFF TO THE WEST.
POOR FLYING CONDITIONS WILL PREVAIL OVERNIGHT AS DEEP LAYER
MOISTURE ON EASTERLY FLOW GETS ENTRENCHED WITH PATCHY -RA/DZ AN
FOG AROUND MAKING FOR WIDESPREAD IFR/LIFR CIGS AND MVFR TO IFR
VSBYS OVERNIGHT. BANDS OF HEAVIER SHOWERS AND POSSIBLE
THUNDERSTORMS ARRIVE TUESDAY WITH WIDESPREAD SUB-VFR CONDITIONS
CONTINUING INTO TUESDAY EVENING.
EXTENDED AVIATION DISCUSSION...
THE MIDWEEK PERIOD WILL BE DOMINATED BY CLOUD COVER AS A DEEP
AREA OF LOW PRESSURE ALOFT SLOWLY DRIFTS INTO THE REGION FROM THE
WEST. SUB VFR CONDITIONS CAN BE EXPECTED AGAIN ON WEDNESDAY WITH
POTENTIAL FOR BANDS OF SHRA/TSRA IN ADDITION TO AREAS OF LIGHT
RAIN AND DRIZZLE NEAR THE BLUE RIDGE. APPEARS ENOUGH DRYING ALOFT
TO PERHAPS SEE IMPROVEMENT TO VFR ACROSS THE EAST LATER THURSDAY
INTO FRIDAY WITH MVFR LIKELY LINGERING AT TIMES ACROSS THE SE WEST
VA LOCATIONS INTO FRIDAY.
&&
.HYDROLOGY...
AS OF 300 PM EDT SUNDAY...
THERE IS A CHANCE FOR MAINSTEM RIVER FLOODING BY MID TO LATE THIS
WEEK. BUT STILL FAR TOO EARLY FOR HIGH CONFIDENCE IN WHICH RIVERS
AND HOW WIDESPREAD FLOODING WILL BE. STAY TUNED.
PATTERN SETTING UP WITH SOME IMPRESSIVE STRONG SIGNALS FOR A
PROLONGED PERIOD OF RAINFALL WITH HEAVY RAIN AMOUNTS BECOMING MORE
LIKELY...ESPECIALLY TUESDAY AFTERNOON INTO WEDNESDAY.
LATEST RUNS OF ENSEMBLE MODEL FORECAST FROM THE GEFS AND THE NAEFS
WERE SUGGESTING AN INCREASING PROBABILITY OF MODERATE RIVER FLOODING
ON THE DAN RIVER AT SOUTH BOSTON AND ON THE ROANOKE AT RANDOLPH.
FLOODING POSSIBILITIES ARE ALSO INDICATED FOR PARTS OF THE JAMES
AND GREENBRIER RIVER BASINS.
FLASH FLOODING APPEARS TO BE LESS OF A LIKELIHOOD AT LEAST AT THE
ONSET AS MUCH OF THE RAINFALL WILL BE OF THE STRATIFORM VARIETY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/PC/WP
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...KK
AVIATION...JH/KM/PC/PM
HYDROLOGY...AMS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
647 PM EDT MON APR 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 349 PM EDT MON APR 28 2014
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM HANGING AROUND
THE MIDWEST FOR THE NEXT SEVERAL DAYS WILL KEEP UNSETTLED WEATHER IN
THE FORECAST. CHANCES FOR THUNDERSTORMS WILL REMAIN TONIGHT THROUGH
TUESDAY NIGHT WITH SOME INSTABILITY AROUND...AND CHANCES FOR RAIN
WILL CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 349 PM EDT MON APR 28 2014
RADAR MOSAIC AT 330 PM SHOWS A LARGE AREA OF SHOWERS WITH SOME
EMBEDDED THUNDER MOVING NORTHEAST THROUGH THE SOUTHERN PORTIONS OF
CENTRAL INDIANA STRETCHING BACK SOUTHWEST INTO SOUTHERN ILLINOIS AND
WESTERN KENTUCKY. ANOTHER LINE OF STORMS COULD BE FOUND ALONG THE
COLD FRONT/DRY LINE IN EASTERN MISSOURI HEADING INTO ILLINOIS...AND
SOME OTHER CELLS FORMING ALONG THE PORTION OF THE WARM FRONT IN IOWA
AND WESTERN TO CENTRAL ILLINOIS. VISIBLE SATELLITE SHOWS CENTRAL
INDIANA SOCKED IN WITH CLOUD COVER AS IT HAS BEEN ALL DAY. HI RES
MODELS CONTINUE TO SHOW BIG DISAGREEMENTS IN THE SHORT TERM AND
HOW/WHERE CONVECTION WILL DEVELOP FOR THE REMAINDER OF THE AFTERNOON
INTO TONIGHT MAKING THIS A FORECAST WITH HIGH UNCERTAINTY.
HRRR MOVES THE CURRENT ECHOES NORTHEAST THROUGH THE AREA OVER THE
NEXT FEW HOURS...BUT THEN SHOWS LITTLE DEVELOPMENT UNTIL THE COLD
FRONT MOVES IN LATER TONIGHT /AROUND 4Z OR SO IN THE WEST/. RAP
DEVELOPS SCATTERED CONVECTION ACROSS THE AREA AND AN ORGANIZED AREA
ALONG THE WARM FRONT STRETCHING ACROSS NORTHERN AND CENTRAL INDIANA.
18Z ILX SOUNDING SHOWED A PRETTY DECENT INVERSION AND BASED ON
ACTIVITY /OR LACK THEREOF/ ACROSS CENTRAL INDIANA INFER THAT THE
INVERSION COULD BE MORE STOUT HERE. IN ADDITION INSTABILITY HERE IS
LIMITED DUE TO THE AFOREMENTIONED CLOUD COVER. NAM12 SHOWS 500 MB
JET MAX APPROACHING OVER THE NEXT COUPLE OF HOURS THOUGH...SO SOME
STRONG FORCING POTENTIAL WITH SOME SHEAR IS STILL OUT THERE. THUS
NOT READY TO ABANDON THE SEVERE RISK YET BUT DO THINK IT COULD BE
DECREASING AT LEAST FOR CENTRAL INDIANA. TIMED THE NEXT FEW HOURS OF
POP GRIDS BASED ON THE HRRR AND RADAR LOOP.
FOR THE TONIGHT PERIOD THERE ARE SOME BIG DIFFERENCES IN
HRRR...RAP...NAM12 AND GFS AS WELL AS SREFS. FINALLY DECIDED GIVEN
THE HIGH UNCERTAINTY WOULD INCLUDE A HIGH CHANCE POP AND SCATTERED
THUNDERSTORM WORDING. DID NOT FEEL CONFIDENT ENOUGH ON
PLACEMENT/TIMING TO GET ANY MORE SPECIFIC THAN THAT UNTIL AFTER 6Z
WHEN CHANCES SHOULD START TO DECREASE FROM WEST TO EAST.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 349 PM EDT MON APR 28 2014
FORECAST FOCUS IS ON POPS THROUGHOUT AND SEVERE POTENTIAL TUESDAY.
MODELS ARE SHOWING AGREEMENT ON GENERAL PATTERN BUT DIFFERENCES ON
THE DETAILS THAT DETERMINE TIMING OF PRECIP. GENERALLY TRIED TO USE
AN AVERAGE.
FOR TUESDAY EXPECT TO SEE A LULL IN THE PRECIP ON TUESDAY MORNING AS
THE FRONT WILL BE NORTH OF THE AREA AND UPPER LOW VORT MAXES ARE NOT
IN FAVORABLE POSITIONS. BY AFTERNOON THOUGH STEEP LAPSE RATES ADVECT
IN AND SOME INSTABILITY BUILDS EVEN THOUGH SOME DRYING OF THE AIR
MASS WILL HAVE OCCURRED. A VORT MAX WILL APPROACH FROM THE SOUTHWEST
LEADING UP TO 0Z. BEST JET DYNAMICS LOOK LIKE THEY WILL SET UP EAST
OF THE AREA...BUT STILL ENOUGH IN PLACE ESPECIALLY WITH THE STEEP
LAPSE RATES THAT LARGE HAIL COULD BE A PROBLEM. STUCK WITH MAV POPS
BUT RAMPED UP TO THEM WITH THE BEST POTENTIAL STARTING AROUND 21Z.
BROUGHT LIKELY IN THE EAST AFTER 0Z WED AS VORT MAX ROTATES THROUGH
THE EASTERN COUNTIES AND ANOTHER WEAK SURFACE BOUNDARY MOVES NORTH
THROUGH THE AREA.
KEPT CHANCES FOR RAIN GOING WEDNESDAY AND THURSDAY UNDER THE
INFLUENCE OF THE UPPER LOW AND DROPPED TO A SLIGHT CHANCE IN THE
SOUTHWEST ON WEDNESDAY NIGHT WITH LESS FORCING AVAILABLE THEN. LOOKS
LIKE MOST INSTABILITY WILL BE MOVING OUT AND THE UPPER LOW WEAKENS
AS IT WOBBLES AROUND WEDNESDAY THROUGH THURSDAY SO DID NOT INCLUDE
THUNDER DURING THOSE TIMES.
FOR TEMPERATURES TUESDAY STUCK CLOSER TO THE COOLER MET NUMBERS WITH
MAV LOOKING TOO WARM GIVEN EXPECTED CLOUD COVER. OTHERWISE GENERALLY
USED CONSENSUS NUMBERS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 203 PM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN
CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS
PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK
TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH
EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR
SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER
LOOKS TO BE IN STORE FOR EARLY NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 290000Z TAF ISSUANCE/...
ISSUED AT 647 PM EDT MON APR 28 2014
MVFR OR LOWER POSSIBLE IN CONVECTION...ESPECIALLY IN THE FIRST 6
HOURS OR SO OF THE TAF PERIOD. OTHERWISE GENERALLY VFR EXPECTED.
AREA OF SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE INTO THE AREA
FROM THE SOUTHWEST EARLY IN THE PERIOD. LATEST OBSERVATIONS NOT
SHOWING A LOT OF MVFR CONDITIONS WITH THESE. THUS WILL GO WITH VFR
CONDITIONS IN THIS AREA WITH VCTS MENTION. OF COURSE IN ANY HEAVIER
CONVECTION MVFR OR LOWER IS POSSIBLE BRIEFLY.
WATCHING LINE OF TSRA ACROSS ILLINOIS THAT IS MOVING TOWARD THE
AREA. MAY HAVE TO ADD TEMPO GROUPS FOR THIS LINE LATER THIS EVENING
IF IT HOLDS TOGETHER. AGAIN MVFR OR WORSE POSSIBLE WITH THIS LINE.
OVERNIGHT SCATTERED SHOWERS ARE STILL POSSIBLE SO WILL KEEP VCSH.
ON TUESDAY ADDITIONAL CONVECTION MAY DEVELOP IN AFTERNOON BUT NOT
SURE ON LOCATION/COVERAGE SO LEFT OUT OF TAFS. WINDS WILL GUST OVER
20KT TUESDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....SMF
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
422 PM EDT MON APR 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 349 PM EDT MON APR 28 2014
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM HANGING AROUND
THE MIDWEST FOR THE NEXT SEVERAL DAYS WILL KEEP UNSETTLED WEATHER IN
THE FORECAST. CHANCES FOR THUNDERSTORMS WILL REMAIN TONIGHT THROUGH
TUESDAY NIGHT WITH SOME INSTABILITY AROUND...AND CHANCES FOR RAIN
WILL CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 349 PM EDT MON APR 28 2014
RADAR MOSAIC AT 330 PM SHOWS A LARGE AREA OF SHOWERS WITH SOME
EMBEDDED THUNDER MOVING NORTHEAST THROUGH THE SOUTHERN PORTIONS OF
CENTRAL INDIANA STRETCHING BACK SOUTHWEST INTO SOUTHERN ILLINOIS AND
WESTERN KENTUCKY. ANOTHER LINE OF STORMS COULD BE FOUND ALONG THE
COLD FRONT/DRY LINE IN EASTERN MISSOURI HEADING INTO ILLINOIS...AND
SOME OTHER CELLS FORMING ALONG THE PORTION OF THE WARM FRONT IN IOWA
AND WESTERN TO CENTRAL ILLINOIS. VISIBLE SATELLITE SHOWS CENTRAL
INDIANA SOCKED IN WITH CLOUD COVER AS IT HAS BEEN ALL DAY. HI RES
MODELS CONTINUE TO SHOW BIG DISAGREEMENTS IN THE SHORT TERM AND
HOW/WHERE CONVECTION WILL DEVELOP FOR THE REMAINDER OF THE AFTERNOON
INTO TONIGHT MAKING THIS A FORECAST WITH HIGH UNCERTAINTY.
HRRR MOVES THE CURRENT ECHOES NORTHEAST THROUGH THE AREA OVER THE
NEXT FEW HOURS...BUT THEN SHOWS LITTLE DEVELOPMENT UNTIL THE COLD
FRONT MOVES IN LATER TONIGHT /AROUND 4Z OR SO IN THE WEST/. RAP
DEVELOPS SCATTERED CONVECTION ACROSS THE AREA AND AN ORGANIZED AREA
ALONG THE WARM FRONT STRETCHING ACROSS NORTHERN AND CENTRAL INDIANA.
18Z ILX SOUNDING SHOWED A PRETTY DECENT INVERSION AND BASED ON
ACTIVITY /OR LACK THEREOF/ ACROSS CENTRAL INDIANA INFER THAT THE
INVERSION COULD BE MORE STOUT HERE. IN ADDITION INSTABILITY HERE IS
LIMITED DUE TO THE AFOREMENTIONED CLOUD COVER. NAM12 SHOWS 500 MB
JET MAX APPROACHING OVER THE NEXT COUPLE OF HOURS THOUGH...SO SOME
STRONG FORCING POTENTIAL WITH SOME SHEAR IS STILL OUT THERE. THUS
NOT READY TO ABANDON THE SEVERE RISK YET BUT DO THINK IT COULD BE
DECREASING AT LEAST FOR CENTRAL INDIANA. TIMED THE NEXT FEW HOURS OF
POP GRIDS BASED ON THE HRRR AND RADAR LOOP.
FOR THE TONIGHT PERIOD THERE ARE SOME BIG DIFFERENCES IN
HRRR...RAP...NAM12 AND GFS AS WELL AS SREFS. FINALLY DECIDED GIVEN
THE HIGH UNCERTAINTY WOULD INCLUDE A HIGH CHANCE POP AND SCATTERED
THUNDERSTORM WORDING. DID NOT FEEL CONFIDENT ENOUGH ON
PLACEMENT/TIMING TO GET ANY MORE SPECIFIC THAN THAT UNTIL AFTER 6Z
WHEN CHANCES SHOULD START TO DECREASE FROM WEST TO EAST.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 349 PM EDT MON APR 28 2014
FORECAST FOCUS IS ON POPS THROUGHOUT AND SEVERE POTENTIAL TUESDAY.
MODELS ARE SHOWING AGREEMENT ON GENERAL PATTERN BUT DIFFERENCES ON
THE DETAILS THAT DETERMINE TIMING OF PRECIP. GENERALLY TRIED TO USE
AN AVERAGE.
FOR TUESDAY EXPECT TO SEE A LULL IN THE PRECIP ON TUESDAY MORNING AS
THE FRONT WILL BE NORTH OF THE AREA AND UPPER LOW VORT MAXES ARE NOT
IN FAVORABLE POSITIONS. BY AFTERNOON THOUGH STEEP LAPSE RATES ADVECT
IN AND SOME INSTABILITY BUILDS EVEN THOUGH SOME DRYING OF THE AIR
MASS WILL HAVE OCCURRED. A VORT MAX WILL APPROACH FROM THE SOUTHWEST
LEADING UP TO 0Z. BEST JET DYNAMICS LOOK LIKE THEY WILL SET UP EAST
OF THE AREA...BUT STILL ENOUGH IN PLACE ESPECIALLY WITH THE STEEP
LAPSE RATES THAT LARGE HAIL COULD BE A PROBLEM. STUCK WITH MAV POPS
BUT RAMPED UP TO THEM WITH THE BEST POTENTIAL STARTING AROUND 21Z.
BROUGHT LIKELY IN THE EAST AFTER 0Z WED AS VORT MAX ROTATES THROUGH
THE EASTERN COUNTIES AND ANOTHER WEAK SURFACE BOUNDARY MOVES NORTH
THROUGH THE AREA.
KEPT CHANCES FOR RAIN GOING WEDNESDAY AND THURSDAY UNDER THE
INFLUENCE OF THE UPPER LOW AND DROPPED TO A SLIGHT CHANCE IN THE
SOUTHWEST ON WEDNESDAY NIGHT WITH LESS FORCING AVAILABLE THEN. LOOKS
LIKE MOST INSTABILITY WILL BE MOVING OUT AND THE UPPER LOW WEAKENS
AS IT WOBBLES AROUND WEDNESDAY THROUGH THURSDAY SO DID NOT INCLUDE
THUNDER DURING THOSE TIMES.
FOR TEMPERATURES TUESDAY STUCK CLOSER TO THE COOLER MET NUMBERS WITH
MAV LOOKING TOO WARM GIVEN EXPECTED CLOUD COVER. OTHERWISE GENERALLY
USED CONSENSUS NUMBERS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 203 PM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN
CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS
PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK
TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH
EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR
SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER
LOOKS TO BE IN STORE FOR EARLY NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 282100Z TAF UPDATE/...
ISSUED AT 422 PM EDT MON APR 28 2014
AREA OF SHOWERS AND ISOLATED THUNDERSTORMS SHOULD STAY SOUTH AND
EAST OF KIND FOR NOW /OTHER THAN PERHAPS SOME SPRINKLES AT THE
MOMENT/ SO REMOVED MENTION. BEFORE ADDITIONAL SHOWERS/STORMS MOVE IN
AFTER 00Z LOOKS LIKE VFR CONDITIONS WILL PREVAIL WITH GUSTY WINDS.
PREVIOUS DISCUSSION FOLLOWS...
GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES
AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN
DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB
GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL
INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL
INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS
EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT
SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER
PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A
LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD
FRONT MOVES THROUGH TUESDAY AFTERNOON.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....SMF
AVIATION...SMF/50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
351 PM EDT MON APR 28 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 349 PM EDT MON APR 28 2014
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM HANGING AROUND
THE MIDWEST FOR THE NEXT SEVERAL DAYS WILL KEEP UNSETTLED WEATHER IN
THE FORECAST. CHANCES FOR THUNDERSTORMS WILL REMAIN TONIGHT THROUGH
TUESDAY NIGHT WITH SOME INSTABILITY AROUND...AND CHANCES FOR RAIN
WILL CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /THIS EVENING AND TONIGHT/...
ISSUED AT 349 PM EDT MON APR 28 2014
RADAR MOSAIC AT 330 PM SHOWS A LARGE AREA OF SHOWERS WITH SOME
EMBEDDED THUNDER MOVING NORTHEAST THROUGH THE SOUTHERN PORTIONS OF
CENTRAL INDIANA STRETCHING BACK SOUTHWEST INTO SOUTHERN ILLINOIS AND
WESTERN KENTUCKY. ANOTHER LINE OF STORMS COULD BE FOUND ALONG THE
COLD FRONT/DRY LINE IN EASTERN MISSOURI HEADING INTO ILLINOIS...AND
SOME OTHER CELLS FORMING ALONG THE PORTION OF THE WARM FRONT IN IOWA
AND WESTERN TO CENTRAL ILLINOIS. VISIBLE SATELLITE SHOWS CENTRAL
INDIANA SOCKED IN WITH CLOUD COVER AS IT HAS BEEN ALL DAY. HI RES
MODELS CONTINUE TO SHOW BIG DISAGREEMENTS IN THE SHORT TERM AND
HOW/WHERE CONVECTION WILL DEVELOP FOR THE REMAINDER OF THE AFTERNOON
INTO TONIGHT MAKING THIS A FORECAST WITH HIGH UNCERTAINTY.
HRRR MOVES THE CURRENT ECHOES NORTHEAST THROUGH THE AREA OVER THE
NEXT FEW HOURS...BUT THEN SHOWS LITTLE DEVELOPMENT UNTIL THE COLD
FRONT MOVES IN LATER TONIGHT /AROUND 4Z OR SO IN THE WEST/. RAP
DEVELOPS SCATTERED CONVECTION ACROSS THE AREA AND AN ORGANIZED AREA
ALONG THE WARM FRONT STRETCHING ACROSS NORTHERN AND CENTRAL INDIANA.
18Z ILX SOUNDING SHOWED A PRETTY DECENT INVERSION AND BASED ON
ACTIVITY /OR LACK THEREOF/ ACROSS CENTRAL INDIANA INFER THAT THE
INVERSION COULD BE MORE STOUT HERE. IN ADDITION INSTABILITY HERE IS
LIMITED DUE TO THE AFOREMENTIONED CLOUD COVER. NAM12 SHOWS 500 MB
JET MAX APPROACHING OVER THE NEXT COUPLE OF HOURS THOUGH...SO SOME
STRONG FORCING POTENTIAL WITH SOME SHEAR IS STILL OUT THERE. THUS
NOT READY TO ABANDON THE SEVERE RISK YET BUT DO THINK IT COULD BE
DECREASING AT LEAST FOR CENTRAL INDIANA. TIMED THE NEXT FEW HOURS OF
POP GRIDS BASED ON THE HRRR AND RADAR LOOP.
FOR THE TONIGHT PERIOD THERE ARE SOME BIG DIFFERENCES IN
HRRR...RAP...NAM12 AND GFS AS WELL AS SREFS. FINALLY DECIDED GIVEN
THE HIGH UNCERTAINTY WOULD INCLUDE A HIGH CHANCE POP AND SCATTERED
THUNDERSTORM WORDING. DID NOT FEEL CONFIDENT ENOUGH ON
PLACEMENT/TIMING TO GET ANY MORE SPECIFIC THAN THAT UNTIL AFTER 6Z
WHEN CHANCES SHOULD START TO DECREASE FROM WEST TO EAST.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 349 PM EDT MON APR 28 2014
FORECAST FOCUS IS ON POPS THROUGHOUT AND SEVERE POTENTIAL TUESDAY.
MODELS ARE SHOWING AGREEMENT ON GENERAL PATTERN BUT DIFFERENCES ON
THE DETAILS THAT DETERMINE TIMING OF PRECIP. GENERALLY TRIED TO USE
AN AVERAGE.
FOR TUESDAY EXPECT TO SEE A LULL IN THE PRECIP ON TUESDAY MORNING AS
THE FRONT WILL BE NORTH OF THE AREA AND UPPER LOW VORT MAXES ARE NOT
IN FAVORABLE POSITIONS. BY AFTERNOON THOUGH STEEP LAPSE RATES ADVECT
IN AND SOME INSTABILITY BUILDS EVEN THOUGH SOME DRYING OF THE AIR
MASS WILL HAVE OCCURRED. A VORT MAX WILL APPROACH FROM THE SOUTHWEST
LEADING UP TO 0Z. BEST JET DYNAMICS LOOK LIKE THEY WILL SET UP EAST
OF THE AREA...BUT STILL ENOUGH IN PLACE ESPECIALLY WITH THE STEEP
LAPSE RATES THAT LARGE HAIL COULD BE A PROBLEM. STUCK WITH MAV POPS
BUT RAMPED UP TO THEM WITH THE BEST POTENTIAL STARTING AROUND 21Z.
BROUGHT LIKELY IN THE EAST AFTER 0Z WED AS VORT MAX ROTATES THROUGH
THE EASTERN COUNTIES AND ANOTHER WEAK SURFACE BOUNDARY MOVES NORTH
THROUGH THE AREA.
KEPT CHANCES FOR RAIN GOING WEDNESDAY AND THURSDAY UNDER THE
INFLUENCE OF THE UPPER LOW AND DROPPED TO A SLIGHT CHANCE IN THE
SOUTHWEST ON WEDNESDAY NIGHT WITH LESS FORCING AVAILABLE THEN. LOOKS
LIKE MOST INSTABILITY WILL BE MOVING OUT AND THE UPPER LOW WEAKENS
AS IT WOBBLES AROUND WEDNESDAY THROUGH THURSDAY SO DID NOT INCLUDE
THUNDER DURING THOSE TIMES.
FOR TEMPERATURES TUESDAY STUCK CLOSER TO THE COOLER MET NUMBERS WITH
MAV LOOKING TOO WARM GIVEN EXPECTED CLOUD COVER. OTHERWISE GENERALLY
USED CONSENSUS NUMBERS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 203 PM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN
CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS
PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK
TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH
EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR
SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER
LOOKS TO BE IN STORE FOR EARLY NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/...
ISSUED AT 115 PM EDT MON APR 28 2014
GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES
AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN
DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB
GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL
INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL
INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS
EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT
SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER
PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A
LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD
FRONT MOVES THROUGH TUESDAY AFTERNOON.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....SMF
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
204 PM EDT MON APR 28 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EDT MON APR 28 2014
A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY
MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK.
THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING
WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 950 AM EDT MON APR 28 2014
RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST
HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN
OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL
TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER
CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING
MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO
NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY
CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS
FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP
MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT
HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED
ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING
DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS
CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL
DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER
UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP
SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK
LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE
POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO
LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT
READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS
SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT
THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER
LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL
TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES
THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH
ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY
TODAY.
SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA
STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS
AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A
LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF
CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO
CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE
AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID
AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM
DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH
ACTIVITY TONIGHT NEAR THE SURFACE FRONT.
TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE
OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE.
ONLY MINOR ADJUSTMENTS PLANNED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 304 AM EDT MON APR 28 2014
MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST
FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE
WEATHER UNSETTLED.
BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER
LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON
TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME.
WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND
TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS
FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON
TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY
DEVELOP.
WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT
AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES.
BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR
TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF
THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 203 PM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES WILL LIFT NORTH INTO SOUTHERN
CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY AS
PRECIPITATION CHANCES WANE AND TEMPERATURES BEGIN TO INCREASE BACK
TOWARD NORMAL. A FEW WAVES WILL ROTATE THROUGH THE REGION THROUGH
EARLY THIS WEEKEND ALLOWING MOSTLY CLOUDY SKIES AND CHANCE FOR
SHOWERS TO PERSIST. A RETURN TO MORE CLIMO TEMPS AND DRY WEATHER
LOOKS TO BE IN STORE FOR EARLY NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/...
ISSUED AT 115 PM EDT MON APR 28 2014
GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES
AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN
DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB
GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL
INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL
INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS
EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT
SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER
PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A
LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD
FRONT MOVES THROUGH TUESDAY AFTERNOON.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....SMF
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
123 PM EDT MON APR 28 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 304 AM EDT MON APR 28 2014
A LARGE AND SLOW MOVING LOW PRESSURE SYSTEM IS EXPECTED TO GRADUALLY
MOVE FROM THE PLAINS INTO THE GREAT LAKES REGION BY LATE THIS WEEK.
THIS LOW WILL KEEP THE WEATHER UNSETTLED FOR MOST OF THIS UPCOMING
WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
ISSUED AT 950 AM EDT MON APR 28 2014
RADAR MOSAIC AT 930 AM SHOWS LARGE AREA OF RAIN OVER THE NORTHEAST
HALF OR SO OF THE AREA MOVING OFF TO THE NORTHEAST WITH MORE RAIN
OVER SOUTHERN ILLINOIS/WESTERN KENTUCKY MOVING NORTHEAST AS WELL
TOWARD SOUTHERN INDIANA. VISIBLE SATELLITE SHOWS A CLEAR SLOT OVER
CENTRAL ILLINOIS...BUT A LOOP OF THIS FEATURE SHOWS IT ROTATING
MAINLY TO THE NORTH AND THUS COULD STAY OVER ILLINOIS AND MOVE INTO
NORTHERN INDIANA BUT KEEP CENTRAL INDIANA IN MOSTLY TO COMPLETELY
CLOUDY SKIES FOR THE DAY. FOR THE UPDATE ADDED SOME TIMING FOR POPS
FOR THE REST OF THE MORNING/EARLY AFTERNOON WITH A BREAK IN PRECIP
MOVING IN FROM THE EAST AND LASTING FOR THE NEXT FEW HOURS. KEPT
HIGH CHANCE TO LIKELY POPS GOING IN THE SOUTH FOR THE AFOREMENTIONED
ECHOES MOVING NORTHEAST FROM S IL/W KY. HI RES MODELS ARE SHOWING
DIFFERENT SCENARIOS FOR THE AFTERNOON/EARLY EVENING AND THIS IS
CONTRIBUTING TO HIGH UNCERTAINTY FOR THAT PERIOD. HRRR SHOWS ALL
DEVELOPMENT OCCURRING TO THE NORTH OF THE AREA WITH NOTHING FURTHER
UNTIL THE COLD FRONT ARRIVES LATER TONIGHT. RAP CONTINUES TO DEVELOP
SCATTERED CONVECTION THIS AFTERNOON. HESITANT TO BUY INTO HRRR HOOK
LINE AND SINKER WITH SUCH A DYNAMIC SYSTEM SO WENT WITH LOW CHANCE
POPS ACROSS THE AREA LATE MORNING/EARLY AFTERNOON INCREASING TO
LIKELY ACROSS THE AREA AFTER 20Z. AGAIN WITH MODEL VARIABILITY...NOT
READY TO CHANGE SEVERE OUTLOOK OR TIMING FROM PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
ADDITIONAL DEVELOPMENT LATER TODAY A LITTLE MORE QUESTIONABLE...AS
SOME OF THE MODEL DATA SUGGEST MORE SHOWER/THUNDERSTORMS DEVELOPMENT
THIS AFTERNOON ALONG THE EDGE OF THE APPROACHING DRY SLOT/STEEPER
LAPSE RATES...WHILE OTHERS SUGGEST DEVELOPMENT MAY HOLD OFF UNTIL
TOWARDS/AFTER 290000Z WHEN SURFACE COLD FRONT/OCCLUSION MOVES
THROUGH. AT THIS POINT...WILL KEEP RATHER HIGH POPS GOING THROUGH
ABOUT MIDNIGHT TONIGHT...WITH THE HIGHEST POPS THROUGH ABOUT MIDDAY
TODAY.
SEVERE POTENTIAL TODAY AND TONIGHT A LITTLE LESS CLEAR. MODEL DATA
STILL SUGGEST ADEQUATE DEEP SHEAR/LAPSE RATES BY LATER THIS
AFTERNOON AND TONIGHT FOR SEVERE...ALTHOUGH THE DEEP SHEAR LOOKS A
LITTLE WEAKER TODAY THAN IT DID YESTERDAY. ALSO...LARGE AMOUNTS OF
CONVECTION DEVELOPING SOUTH OF THE OHIO RIVER IS GETTING CLOSE TO
CUTTING OFF THE FLOW OF DEEPER MOISTURE/MORE UNSTABLE AIR INTO THE
AREA. APPEARS THE BEST CHANCE FOR SEVERE WILL BE FROM THE MID
AFTERNOON HOURS UNTIL ABOUT MIDNIGHT TONIGHT...EMANATING EITHER FROM
DEVELOPMENT ALONG THE EDGE OF DRY SLOT LATER THIS AFTERNOON OR WITH
ACTIVITY TONIGHT NEAR THE SURFACE FRONT.
TODAY/S GFS MOS SEEMS TO MAY LOST ITS WARM BIAS OF THE PAST COUPLE
OF DAYS...AND THE NUMBERS FOR TODAY AND TONIGHT LOOK MORE REASONABLE.
ONLY MINOR ADJUSTMENTS PLANNED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 304 AM EDT MON APR 28 2014
MODEL DATA SUGGEST A LARGE UPPER LOW WILL GRADUALLY SHIFT NORTHEAST
FROM THE PLAINS INTO THE MIDWEST DURING THIS PERIOD...KEEPING THE
WEATHER UNSETTLED.
BY TUESDAY...MODEL DATA SUGGEST DRIER AIR WRAPPING AROUND THE UPPER
LOW WILL MOVE INTO THE AREA. LAPSE RATES ARE QUITE STEEP ON
TUESDAY...HOWEVER BETTER SHEAR PUSHES OFF TO THE EAST WITH TIME.
WILL GO WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ON TUESDAY AND
TUESDAY NIGHT AS A SURFACE TROUGH MOVES THROUGH...WHICH MAY SERVE AS
FOCUS FOR CONVECTION. THE PRESENCE OF THE STEEP LAPSE RATES ON
TUESDAY SUGGEST HAIL POTENTIAL WITH ANY STRONGER CELLS THAT MAY
DEVELOP.
WILL KEEP SOME CHANCE POPS GOING INTO WEDNESDAY AND WEDNESDAY NIGHT
AS FILLING UPPER LOW MOVES INTO THE GREAT LAKES.
BASED OFF ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS HIGHS FOR
TUESDAY AND WEDNESDAY LOOK A LITTLE WARM. WILL CUT A FEW DEGREES OFF
THE GUIDANCE HIGHS ON BOTH DAYS. LOWS LOOK REASONABLE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON APR 28 2014
A LARGE UPPER LOW OVER THE GREAT LAKES THURSDAY WILL LIFT NORTH INTO
SOUTHERN CANADA OVER THE WEEKEND. IT WILL CONTINUE TO INFLUENCE OUR
WEATHER...BUT ITS EFFECTS WILL LESSEN SOME BY SUNDAY.
A CYCLONIC UPPER FLOW FROM THIS UPPER LOW WILL KEEP MOSTLY CLOUDY
SKIES AND CHANCES OF SHOWERS THURSDAY INTO SATURDAY. A WEAK COLD
FRONT WILL MOVE ACROSS OUR REGION EARLY SATURDAY FOLLOWED BY A HIGH
PRESSURE RIDGE SATURDAY NIGHT. SEVERAL MODELS INDICATE ANOTHER
CHANCE OF PRECIPITATION MAY BEGIN SUNDAY AS ANOTHER SYSTEM
APPROACHES.
ADDED ISOLATED THUNDER TO SUNDAY AS MODELS INDICATE MU CAPES OF UP
TO 500 J/KG. OTHERWISE...ANY PRECIPITATION WILL BE ONLY BE
SCATTERED LIGHT SHOWERS OR SPRINKLES.
TEMPERATURES WILL REMAIN QUITE COOL THURSDAY THROUGH SATURDAY AND
THEN MODERATE A LITTLE SUNDAY. ONLY MADE MINOR TWEAKS TO ALL BLEND
TEMPERATURES MAINLY TO RAISE MINS SLIGHTLY THURSDAY AND FRIDAY NIGHT
AS THERE WILL BE LOTS OF CLOUDS.
&&
.AVIATION /DISCUSSION FOR 281800Z TAF ISSUANCE/...
ISSUED AT 115 PM EDT MON APR 28 2014
GUIDANCE IS INDICATING THERE WILL BE ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. TIMING VARIES
AMONG THE MODELS SO THE AVIATION FORECAST IS VERY DIFFICULT TO PIN
DOWN AT THIS TIME. BASED ON HRRR...ADDED -SHRA AND VCTS WITH CB
GROUPS TO MANY OF THE TAF SITES AS THIS SHORT RANGE MODEL
INDICATES THE NEXT ROUND FOR SHOWERS WILL BEGIN IMPACTING CENTRAL
INDIANA. THEN AS A WARM FRONT LIFTS NORTH OVER THE REGION THIS
EVENING AND WE ARE FIRMLY PLACED IN THE WARM SECTOR EXPECT
SCATTERED SHRA/TSRA TO CONTINUE OVERNIGHT. COULD BE ANOTHER
PERIOD OF MVFR CEILINGS TONIGHT WHICH WAS INDICATED IN THE TAFS. A
LULL IN ACTIVITY MAY BE IN STORE FOR EARLY TOMORROW BEFORE A COLD
FRONT MOVES THROUGH TUESDAY AFTERNOON.
EAST OR SOUTHEAST WINDS UP TO 15 KNOTS WILL BECOME SOUTH LATE
TONIGHT AND SOUTH TO SOUTHWEST AROUND 10 KNOTS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....JH
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1238 PM CDT MON APR 28 2014
.UPDATE...
ISSUED AT 1126 AM CDT MON APR 28 2014
THE FRONTAL BOUNDARY IS ROUGHLY ALONG A KTQE...KAWG...TO KCMI LINE
AT 16Z AND IT HAS NOT MOVED FOR SEVERAL HOURS.
TRENDS IN THE RAP INDICATE VERY LITTLE IN THE WAY OF MOMENT OF
THIS FRONTAL BOUNDARY THIS AFTERNOON. IF CORRECT...ROUGHLY THE
NORTHERN HALF OF THE AREA WILL REMAIN IN THE 50S WITH THE HWY 20
CORRIDOR POSSIBLY STRUGGLING TO REACH 50.
SATELLITE TRENDS INDICATE THERMALS ARE ACTIVE WHICH HAS ALLOWED CU
TO DEVELOP ALONG/AHEAD OF THE COLD FRONT ACROSS MISSOURI.
CONVECTION SHOULD DEVELOP WITHIN A FEW HOURS FROM CENTRAL INTO
SOUTHERN MISSOURI ALONG THE FRONT AND MOVE NORTHEAST.
PRECIPITATION CHANCES SHOULD THEREFORE BE ON THE INCREASE STARTING
AROUND MID AFTERNOON ACROSS THE AREA.
UPDATE ISSUED AT 923 AM CDT MON APR 28 2014
RADAR TRENDS INDICATE SHOWERS ACROSS THE NORTHERN PARTS OF THE
AREA WILL CONTINUE TO SLOWLY DECAY THE REMAINDER OF THE MORNING.
CLOUDS AND STRONG EASTERLY FLOW NORTH OF THE PRONOUNCED FRONT
SOUTH OF I-80 WILL KEEP THIS AREA COOL FOR MUCH OF THE DAY. STRONG
DIURNAL HEATING SOUTH OF THE FRONT IS EXPECTED TO SET THE STAGE
FOR NEW CONVECTION DEVELOPING EITHER LATE THIS MORNING OR DURING
THE EARLY AFTERNOON. SATELLITE TRENDS HAS A NARROW BAND OF ACCAS
IN SOUTHERN MISSOURI INDICATING INSTABILITY FOR NEW STORMS TO
DEVELOP.
&&
.SYNOPSIS...
ISSUED AT 357 AM CDT MON APR 28 2014
NEARLY STACKED SURFACE AND UPPER LEVEL LOWS WERE LOCATED OVER
CENTRAL NEB EARLY THIS MORNING. WELL OUT IN ADVANCE...AN ELONGATED
COMPLEX OF SEVERE STORMS STRETCHED FROM EASTERN TX THROUGH THE MID
MS VALLEY INTO THE OHIO RIVER VALLEY. OVER THE LOCAL AREA...
WIDESPREAD SHOWERS AND THUNDERSTORMS SUNDAY EVENING HAVE SINCE
STRATIFORMED INTO MAINLY WEAKENING LIGHT SHOWERS DRIFTING NORTHWARD
THROUGH THE REGION. STRONG EASTERLY WINDS CONTINUE...FROM 20 TO 30 MPH AND
AS HIGH AS 30 TO 40 MPH AT TIMES MAINLY NORTH OF I-80. TO THE
SOUTH...WINDS WERE MUCH LIGHTER AND VEERED TO MORE SOUTHEASTERLY
ALONG AND SOUTH OF THE MAIN STATIONARY FRONT CONNECTED TO THE NEB
LOW. IN THE LOCAL AREA THIS BOUNDARY RAN ROUGHLY FROM JUST NORTH OF
WASHINGTON SOUTHEAST TO NORTH OF MACOMB. TEMPERATURES AND DEWPOINTS
WERE IN THE UPPER 50S TO LOWER 60S SOUTH OF THIS BOUNDARY...WHILE TO
THE NORTH TEMPERATURES RANGED FROM THE LOWER 40S NORTH TO LOWER 50S
ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM...(TODAY)
ISSUED AT 357 AM CDT MON APR 28 2014
FOCUS IS ON THREAT FOR MORE SEVERE WEATHER TODAY. SHARP FRONTAL
BOUNDARY WILL LIKELY REMAIN IN PLACE ACROSS THE SOUTH THROUGH
MIDDAY...THEN TRY TO LIFT NORTH TOWARD EVENING. PRIMARY SEVERE
WEATHER THREAT WILL BE CENTERED PRIMARILY ON SE IA INTO W CENTRAL IL
THIS AFTERNOON. UPPER LEVEL DIFLUENCE AND MID LEVEL LIFT ASSOCIATED
WITH A LOBE OF ENERGY ROTATING AROUND THE BASE OF THE NEB LOW FOCUSES
ON THIS REGION BY AFTERNOON. THIS WILL ENHANCE LIFT OVER THE FRONTAL
BOUNDARY...AND WHERE MODELS INDICATE A POTENTIAL FOR MIXED LAYER
CAPES OF 1000 J/KG OR HIGHER...SEVERE STORMS WITH LARGE HAIL AND
DAMAGING WIND WILL BE POSSIBLE. THIS APPEARS TO BE MAXIMIZED OVER
FAR SE IA INTO W CENTRAL IL...WHERE SPC HAS A SLIGHT RISK. IT IS IN
THIS REGION THAT THE BETTER SHEAR OVER THE EAST AND HIGHER
INSTABILITY AXIS FROM CENTRAL IL REACHING INTO CENTRAL IA MAY
OVERLAP. THERE WILL BE A RISK OF TORNADIC STORMS...ESPECIALLY IF
THE MODEL ADVERTISED WEAK LOW OR TRIPLE POINT MIGRATES EASTWARD
ALONG THE BOUNDARY INTO THIS MORE FAVORABLE ENVIRONMENT. IF THE
BOUNDARY WERE TO PUSH FURTHER NORTH THAN ANTICIPATED DURING PEAK
HEATING...AS SOME MODELS DEPICT...THIS RISK OF SEVERE STORMS WOULD EXTEND
FURTHER NORTH.
THE RISK FOR HEAVY RAIN APPEARS TO BE SOMEWHAT LESS CERTAIN
CONSIDERING THE LARGE COMPLEXES TO THE SOUTH THAT MAY INTERRUPT THE
MOISTURE FEED. THE GREATEST FEED OF DEEP MOISTURE APPEARS TO BE
MAXIMIZED OVER THE AREA TONIGHT...THEN MODEL PW FIELDS SHOW A
WEAKENING AREA AXIS REACHING INTO NORTHERN IL AND EASTERN IA FROM
THE SOUTHEAST TODAY. ANY SEVERE STORMS THAT DEVELOP THIS AFTERNOON
WILL CERTAINLY BE CAPABLE OF HEAVY RAINFALL...BUT OUTSIDE OF THESE...
RAINFALL AMOUNTS SHOULD NOT BE EXCESSIVE AND HAVE QPF AMOUNTS
GENERALLY IN A QUARTER TO HALF INCH RANGE. THE SHARP BOUNDARY WILL
AGAIN RESULT IN A WIDE RANGE OF TEMPERATURE AND HAVE HIGHS FROM
THE 50S AND 60S ACROSS THE NORTH WITH 70S FAR SOUTH. ..11..
.LONG TERM...(TONIGHT THROUGH NEXT SUNDAY)
ISSUED AT 357 AM CDT MON APR 28 2014
TONIGHT...SEVERAL HIRES PROGS AND ASSESSING STANDARD 00Z RUN
MODELS SUGGEST AN ARCING CLUSTER OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO PUSH NORTH AND NORTHEAST ACRS THE NORTHERN 2/3S OF THE
DVN CWA EARLY THIS EVENING WHILE NEARLY STACKED VORTEX ROLLS ACRS
SOUTHWESTERN IA. LINGERING SHEAR AND THERMODYNAMIC PROFILES STILL
SUGGEST A FEW STORMS MAY BE STRONG OR SVR THROUGH 02Z TUE ALONG AND
JUST NORTH OF OCCLUDED SFC FRONT WHICH IS GENERALLY SREF PLACED ALONG
I80...BUT WONDER IF MODELS ARE TOO FAR NORTH WITH THIS FEATURE STILL
AT THIS POINT. MUCH OF THE CONVECTIVE ACTIVITY MAY THEN BE ON THE
WANE AND EXITING TO THE NORTH OF THE DVN CWA AFTER 03Z THIS
EVENING...WITH ADDITIONAL RAINFALL AMOUNTS OF 0.25 TO 0.75 OF AN INCH
WHERE THE BAND/MAIN CLUSTER OF STORMS MIGRATES NORTHWARD ACRS.
CURRENT THINKING THIS ALONG AND NORTH OF I80 AN TARGETING THE
NORTHEASTERN THIRD OF THE DVN CWA. WILL HAVE TO WATCH FOR LOW
CLOUDS...FOG AND DRIZZLE IN VCNTY OF LINGERING OCCLUSION OVERNIGHT
AFTER THE RAIN CLEARS. WILL HAVE TO WATCH FOR ADDITIONAL WRAP-AROUND
SHOWERS OR HYBRID RAIN BANDS ENTERING THE NORTHWESTERN CWA TOWARD
DAWN TUE AS UPPER LOW PUSHES TOWARD THE WESTERN CWA. LOW OVERNIGHT
GENERALLY IN THE 40S.
TUESDAY AND WEDNESDAY...LATEST 00Z RUN MEDIUM RANGE SOLUTIONS
CONTINUE TO SUGGEST LARGE SUB TROPICAL VORTEX-NEARLY STACKED
MONSTER CYCLONE TO SLOW ROLL IN SOME FASHION ACRS IA TOWARD THE
WESTERN GRT LKS THIS PERIOD. WITH THE CENTER OVERHEAD AND DIURNALLY
UNSTABLE SOUNDINGS DEVELOPING ON TUE...FEEL THERE COULD BE MORE
SCTRD TO ISOLATED THUNDERSTORMS ALONG WITH INHERENT SHOWERS AS THE
DAY PROGRESSES. VERTICAL THERMAL PROFILES AND IDEAL WBZ/FZL HEIGHTS
CONTINUE TO SUGGEST SOME OF THESE STORMS COULD PRODUCE HAIL WITH ANY
SUSTAINED UPDRAFTS. SCTRD SHOWERS/STORMS TO WANE DIURNALLY AFTER
SUNSET TUE NIGHT INTO EARLY WED MORNING. AMBIENT TEMPS TO COOL BY WED
INTO THE MID 50S OR EVEN THE UPPER 40S AS LOW TO MID LEVEL COLD
CONVEYOR INCREASES INTO THE BACKSIDE OF CYCLONE COMPLEX. MORE SHOWERS
WED AS SATELLITE VORT SPOKE ROTATES ACRS THE REGION.
THURSDAY THROUGH NEXT SUNDAY...LONGER RANGE INDICATIONS ARE NOW A
BIT MORE PROGRESSIVE/LESS BLOCKED WITH UPPER LOW ROLLING ALONG
INTO THE GRT LKS OR EVEN TOWARD THE SOUTHERN JAMES BAY REGION
BY FRI. STILL EXPECT OCCASIONAL ROUNDS OF SHOWERS ESPECIALLY
DURING THE DAY...AS WELL AS WELL BELOW NORMAL TEMPS THROUGH THE
PERIOD. HIGHS THU AND FRI ONLY IN THE 50S...HAPPY MAY DAY. RESULTANT
LARGE/BROAD SCALE L/W UPPER TROF PATTERN ACRS THE EASTERN HALF OF THE
CONUS TO CONTINUE A RATHER COOL TEMP REGIME INTO THE WEEKEND FOR MUCH
OF THE UPPER MIDWEST/MS RVR VALLEY REGION. BUT THEN LONGER RANGE
SIGNALS AND UPPER JET PATTERNS SUGGEST A FLATTENING OF THE MEAN
STEERING FLOW REGIME ACRS MUCH OF THE CONUS AS THE WEEKEND
PROGRESSES. EMBEDDED RIDGE RIDING/DAMPENING WAVE AND SOME LLVL
BAROCLINIC TIGHTENING MAY COMBINE TO BRING MORE RAIN CHANCES TO THE
REGION BY LATE SAT NIGHT OR NEXT SUNDAY. ..12..
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1235 PM CDT MON APR 28 2014
IFR CONDS THROUGH MOST OF THIS TAF CYCLE AT KCID/KDBQ OTHERWISE
IFR AT KMLI BECOMING MVFR CONDS THIS EVENING. VFR CONDS THROUGH
THIS TAF CYCLE AT KBRL. A LINE OF THUNDERSTORMS SHOULD DEVELOP IN
SOUTHEAST IA EARLY TO MID AFTERNOON IMPACTING KBRL AND THEN SPREADING
NORTHEAST OVER THE REMAINING TAF SITES LATE THIS AFTERNOON AND EVENING.
SOME OF THE STORMS ALONG AND SOUTH OF I-80 MAY PRODUCE LARGE HAIL
AND DAMAGING WINDS. EAST TO SOUTHEAST WINDS SUSTAINED 15 TO 20
KNOTS WITH GUSTS TO 25 TO 30 KNOTS THIS AFTERNOON...DIMINISHING TO
LESS THAN 10 KNOTS THIS EVENING. NORTHEAST WINDS LESS THAN 10
KNOTS ON TUESDAY AT KCID/KDBQ BUT SOUTHWEST WINDS AT KMLI/KBRL.
&&
.HYDROLOGY...
ISSUED AT 357 AM CDT MON APR 28 2014
THE FLOOD WATCH FOR AREA RIVERS AND STREAMS CONTINUES TODAY AND
THIS EVENING. THE THREAT OF FLOODING ON AREA TRIBUTARIES AND THE
MISSISSIPPI RIVER WILL INCREASE AS THE WEEK PROGRESSES WITH A
ACCUMULATIVE EFFECT OF SEVERAL RAIN EVENTS...INCLUDING THIS PAST
SUNDAY EVENING/S HEAVY RAIN...THEN MORE LOCALIZED HEAVY RAIN POSSIBLE
THIS AFTERNOON AND EVENING. LATEST THINKING SUGGESTS WIDESPREAD
RAINFALL AMOUNTS OF 1 TO 4 INCHES WILL FALL OVER MUCH OF THE FORECAST
AREA BY WEDNESDAY...INCLUDING THE RAINFALL FROM YESTERDAY AND LAST
NIGHT. SINCE THE PRECIPITATION WILL OCCUR OVER AN EXTENDED PERIOD OF
TIME...THE THREAT OF FLASH FLOODING WILL BE LOW. HOWEVER...RIVER
FLOODING IS EXPECTED WITH SEVERAL OF THE AREA TRIBUTARIES AND THE
MISSISSIPPI RIVER POSSIBLY SEEING AT LEAST MINOR TO MODERATE FLOODING
BY THE MIDDLE OF THE WEEK.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR BENTON-BUCHANAN-CEDAR-
CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON-
JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-
SCOTT-VAN BUREN-WASHINGTON.
IL...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FLOOD WATCH UNTIL MIDNIGHT CDT TONIGHT FOR CLARK-SCOTLAND.
&&
$$
UPDATE...08
SYNOPSIS...11
SHORT TERM...11
LONG TERM...12
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1134 AM CDT MON APR 28 2014
.UPDATE...
ISSUED AT 1126 AM CDT MON APR 28 2014
THE FRONTAL BOUNDARY IS ROUGHLY ALONG A KTQE...KAWG...TO KCMI LINE
AT 16Z AND IT HAS NOT MOVED FOR SEVERAL HOURS.
TRENDS IN THE RAP INDICATE VERY LITTLE IN THE WAY OF MOMENT OF
THIS FRONTAL BOUNDARY THIS AFTERNOON. IF CORRECT...ROUGHLY THE
NORTHERN HALF OF THE AREA WILL REMAIN IN THE 50S WITH THE HWY 20
CORRIDOR POSSIBLY STRUGGLING TO REACH 50.
SATELLITE TRENDS INDICATE THERMALS ARE ACTIVE WHICH HAS ALLOWED CU
TO DEVELOP ALONG/AHEAD OF THE COLD FRONT ACROSS MISSOURI.
CONVECTION SHOULD DEVELOP WITHIN A FEW HOURS FROM CENTRAL INTO
SOUTHERN MISSOURI ALONG THE FRONT AND MOVE NORTHEAST.
PRECIPITATION CHANCES SHOULD THEREFORE BE ON THE INCREASE STARTING
AROUND MID AFTERNOON ACROSS THE AREA.
UPDATE ISSUED AT 923 AM CDT MON APR 28 2014
RADAR TRENDS INDICATE SHOWERS ACROSS THE NORTHERN PARTS OF THE
AREA WILL CONTINUE TO SLOWLY DECAY THE REMAINDER OF THE MORNING.
CLOUDS AND STRONG EASTERLY FLOW NORTH OF THE PRONOUNCED FRONT
SOUTH OF I-80 WILL KEEP THIS AREA COOL FOR MUCH OF THE DAY. STRONG
DIURNAL HEATING SOUTH OF THE FRONT IS EXPECTED TO SET THE STAGE
FOR NEW CONVECTION DEVELOPING EITHER LATE THIS MORNING OR DURING
THE EARLY AFTERNOON. SATELLITE TRENDS HAS A NARROW BAND OF ACCAS
IN SOUTHERN MISSOURI INDICATING INSTABILITY FOR NEW STORMS TO
DEVELOP.
&&
.SYNOPSIS...
ISSUED AT 357 AM CDT MON APR 28 2014
NEARLY STACKED SURFACE AND UPPER LEVEL LOWS WERE LOCATED OVER
CENTRAL NEB EARLY THIS MORNING. WELL OUT IN ADVANCE...AN ELONGATED
COMPLEX OF SEVERE STORMS STRETCHED FROM EASTERN TX THROUGH THE MID
MS VALLEY INTO THE OHIO RIVER VALLEY. OVER THE LOCAL AREA...
WIDESPREAD SHOWERS AND THUNDERSTORMS SUNDAY EVENING HAVE SINCE
STRATIFORMED INTO MAINLY WEAKENING LIGHT SHOWERS DRIFTING NORTHWARD
THROUGH THE REGION. STRONG EASTERLY WINDS CONTINUE...FROM 20 TO 30 MPH AND
AS HIGH AS 30 TO 40 MPH AT TIMES MAINLY NORTH OF I-80. TO THE
SOUTH...WINDS WERE MUCH LIGHTER AND VEERED TO MORE SOUTHEASTERLY
ALONG AND SOUTH OF THE MAIN STATIONARY FRONT CONNECTED TO THE NEB
LOW. IN THE LOCAL AREA THIS BOUNDARY RAN ROUGHLY FROM JUST NORTH OF
WASHINGTON SOUTHEAST TO NORTH OF MACOMB. TEMPERATURES AND DEWPOINTS
WERE IN THE UPPER 50S TO LOWER 60S SOUTH OF THIS BOUNDARY...WHILE TO
THE NORTH TEMPERATURES RANGED FROM THE LOWER 40S NORTH TO LOWER 50S
ALONG THE I-80 CORRIDOR.
&&
.SHORT TERM...(TODAY)
ISSUED AT 357 AM CDT MON APR 28 2014
FOCUS IS ON THREAT FOR MORE SEVERE WEATHER TODAY. SHARP FRONTAL
BOUNDARY WILL LIKELY REMAIN IN PLACE ACROSS THE SOUTH THROUGH
MIDDAY...THEN TRY TO LIFT NORTH TOWARD EVENING. PRIMARY SEVERE
WEATHER THREAT WILL BE CENTERED PRIMARILY ON SE IA INTO W CENTRAL IL
THIS AFTERNOON. UPPER LEVEL DIFLUENCE AND MID LEVEL LIFT ASSOCIATED
WITH A LOBE OF ENERGY ROTATING AROUND THE BASE OF THE NEB LOW FOCUSES
ON THIS REGION BY AFTERNOON. THIS WILL ENHANCE LIFT OVER THE FRONTAL
BOUNDARY...AND WHERE MODELS INDICATE A POTENTIAL FOR MIXED LAYER
CAPES OF 1000 J/KG OR HIGHER...SEVERE STORMS WITH LARGE HAIL AND
DAMAGING WIND WILL BE POSSIBLE. THIS APPEARS TO BE MAXIMIZED OVER
FAR SE IA INTO W CENTRAL IL...WHERE SPC HAS A SLIGHT RISK. IT IS IN
THIS REGION THAT THE BETTER SHEAR OVER THE EAST AND HIGHER
INSTABILITY AXIS FROM CENTRAL IL REACHING INTO CENTRAL IA MAY
OVERLAP. THERE WILL BE A RISK OF TORNADIC STORMS...ESPECIALLY IF
THE MODEL ADVERTISED WEAK LOW OR TRIPLE POINT MIGRATES EASTWARD
ALONG THE BOUNDARY INTO THIS MORE FAVORABLE ENVIRONMENT. IF THE
BOUNDARY WERE TO PUSH FURTHER NORTH THAN ANTICIPATED DURING PEAK
HEATING...AS SOME MODELS DEPICT...THIS RISK OF SEVERE STORMS WOULD EXTEND
FURTHER NORTH.
THE RISK FOR HEAVY RAIN APPEARS TO BE SOMEWHAT LESS CERTAIN
CONSIDERING THE LARGE COMPLEXES TO THE SOUTH THAT MAY INTERRUPT THE
MOISTURE FEED. THE GREATEST FEED OF DEEP MOISTURE APPEARS TO BE
MAXIMIZED OVER THE AREA TONIGHT...THEN MODEL PW FIELDS SHOW A
WEAKENING AREA AXIS REACHING INTO NORTHERN IL AND EASTERN IA FROM
THE SOUTHEAST TODAY. ANY SEVERE STORMS THAT DEVELOP THIS AFTERNOON
WILL CERTAINLY BE CAPABLE OF HEAVY RAINFALL...BUT OUTSIDE OF THESE...
RAINFALL AMOUNTS SHOULD NOT BE EXCESSIVE AND HAVE QPF AMOUNTS
GENERALLY IN A QUARTER TO HALF INCH RANGE. THE SHARP BOUNDARY WILL
AGAIN RESULT IN A WIDE RANGE OF TEMPERATURE AND HAVE HIGHS FROM
THE 50S AND 60S ACROSS THE NORTH WITH 70S FAR SOUTH. ..11..
.LONG TERM...(TONIGHT THROUGH NEXT SUNDAY)
ISSUED AT 357 AM CDT MON APR 28 2014
TONIGHT...SEVERAL HIRES PROGS AND ASSESSING STANDARD 00Z RUN
MODELS SUGGEST AN ARCING CLUSTER OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO PUSH NORTH AND NORTHEAST ACRS THE NORTHERN 2/3S OF THE
DVN CWA EARLY THIS EVENING WHILE NEARLY STACKED VORTEX ROLLS ACRS
SOUTHWESTERN IA. LINGERING SHEAR AND THERMODYNAMIC PROFILES STILL
SUGGEST A FEW STORMS MAY BE STRONG OR SVR THROUGH 02Z TUE ALONG AND
JUST NORTH OF OCCLUDED SFC FRONT WHICH IS GENERALLY SREF PLACED ALONG
I80...BUT WONDER IF MODELS ARE TOO FAR NORTH WITH THIS FEATURE STILL
AT THIS POINT. MUCH OF THE CONVECTIVE ACTIVITY MAY THEN BE ON THE
WANE AND EXITING TO THE NORTH OF THE DVN CWA AFTER 03Z THIS
EVENING...WITH ADDITIONAL RAINFALL AMOUNTS OF 0.25 TO 0.75 OF AN INCH
WHERE THE BAND/MAIN CLUSTER OF STORMS MIGRATES NORTHWARD ACRS.
CURRENT THINKING THIS ALONG AND NORTH OF I80 AN TARGETING THE
NORTHEASTERN THIRD OF THE DVN CWA. WILL HAVE TO WATCH FOR LOW
CLOUDS...FOG AND DRIZZLE IN VCNTY OF LINGERING OCCLUSION OVERNIGHT
AFTER THE RAIN CLEARS. WILL HAVE TO WATCH FOR ADDITIONAL WRAP-AROUND
SHOWERS OR HYBRID RAIN BANDS ENTERING THE NORTHWESTERN CWA TOWARD
DAWN TUE AS UPPER LOW PUSHES TOWARD THE WESTERN CWA. LOW OVERNIGHT
GENERALLY IN THE 40S.
TUESDAY AND WEDNESDAY...LATEST 00Z RUN MEDIUM RANGE SOLUTIONS
CONTINUE TO SUGGEST LARGE SUB TROPICAL VORTEX-NEARLY STACKED
MONSTER CYCLONE TO SLOW ROLL IN SOME FASHION ACRS IA TOWARD THE
WESTERN GRT LKS THIS PERIOD. WITH THE CENTER OVERHEAD AND DIURNALLY
UNSTABLE SOUNDINGS DEVELOPING ON TUE...FEEL THERE COULD BE MORE
SCTRD TO ISOLATED THUNDERSTORMS ALONG WITH INHERENT SHOWERS AS THE
DAY PROGRESSES. VERTICAL THERMAL PROFILES AND IDEAL WBZ/FZL HEIGHTS
CONTINUE TO SUGGEST SOME OF THESE STORMS COULD PRODUCE HAIL WITH ANY
SUSTAINED UPDRAFTS. SCTRD SHOWERS/STORMS TO WANE DIURNALLY AFTER
SUNSET TUE NIGHT INTO EARLY WED MORNING. AMBIENT TEMPS TO COOL BY WED
INTO THE MID 50S OR EVEN THE UPPER 40S AS LOW TO MID LEVEL COLD
CONVEYOR INCREASES INTO THE BACKSIDE OF CYCLONE COMPLEX. MORE SHOWERS
WED AS SATELLITE VORT SPOKE ROTATES ACRS THE REGION.
THURSDAY THROUGH NEXT SUNDAY...LONGER RANGE INDICATIONS ARE NOW A
BIT MORE PROGRESSIVE/LESS BLOCKED WITH UPPER LOW ROLLING ALONG
INTO THE GRT LKS OR EVEN TOWARD THE SOUTHERN JAMES BAY REGION
BY FRI. STILL EXPECT OCCASIONAL ROUNDS OF SHOWERS ESPECIALLY
DURING THE DAY...AS WELL AS WELL BELOW NORMAL TEMPS THROUGH THE
PERIOD. HIGHS THU AND FRI ONLY IN THE 50S...HAPPY MAY DAY. RESULTANT
LARGE/BROAD SCALE L/W UPPER TROF PATTERN ACRS THE EASTERN HALF OF THE
CONUS TO CONTINUE A RATHER COOL TEMP REGIME INTO THE WEEKEND FOR MUCH
OF THE UPPER MIDWEST/MS RVR VALLEY REGION. BUT THEN LONGER RANGE
SIGNALS AND UPPER JET PATTERNS SUGGEST A FLATTENING OF THE MEAN
STEERING FLOW REGIME ACRS MUCH OF THE CONUS AS THE WEEKEND
PROGRESSES. EMBEDDED RIDGE RIDING/DAMPENING WAVE AND SOME LLVL
BAROCLINIC TIGHTENING MAY COMBINE TO BRING MORE RAIN CHANCES TO THE
REGION BY LATE SAT NIGHT OR NEXT SUNDAY. ..12..
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 700 AM CDT MON APR 28 2014
CIGS WERE LOWERING TO IFR NORTH OF A STATIONARY FRONT REACHING
ACROSS SOUTHERN IOWA INTO CENTRAL ILLINOIS EARLY THIS MORNING. STRONG
EASTERLY WINDS NORTH OF THIS BOUNDARY WILL CONTINUE THROUGH MUCH
OF THE DAY AT CID...MLI...AND DBQ. THE IFR CONDITIONS DUE TO THE
LOW CIGS AND LIGHT FOG SHOULD IMPROVE TO MVFR BY MID MORNING AT
THESE SITES...WHILE BRL REMAINS VFR. THIS AFTERNOON...ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED TO LIFT THROUGH THE
REGION. LATEST FORECASTS HAVE THIS HANDLED WITH A TEMPO GROUP AT
BRL...WHILE LOWER CONFIDENCE TIMING AND COVERAGE AFFECTING THE
OTHER TERMINALS WILL MAINTAIN PROB30 WORDING. WINDS WILL DIMINISH
TONIGHT AND VEER A BIT MORE SOUTHEASTERLY AS THE FRONT TRIES TO
LIFT NORTH. THIS NORTHWARD SHIFT SHOULD RESULT IN MVFR TO VFR
CONDITIONS AT BRL AND MLI...WHILE CID AND DBQ LIKELY LOWER TO IFR.
&&
.HYDROLOGY...
ISSUED AT 357 AM CDT MON APR 28 2014
THE FLOOD WATCH FOR AREA RIVERS AND STREAMS CONTINUES TODAY AND
THIS EVENING. THE THREAT OF FLOODING ON AREA TRIBUTARIES AND THE
MISSISSIPPI RIVER WILL INCREASE AS THE WEEK PROGRESSES WITH A
ACCUMULATIVE EFFECT OF SEVERAL RAIN EVENTS...INCLUDING THIS PAST
SUNDAY EVENING/S HEAVY RAIN...THEN MORE LOCALIZED HEAVY RAIN POSSIBLE
THIS AFTERNOON AND EVENING. LATEST THINKING SUGGESTS WIDESPREAD
RAINFALL AMOUNTS OF 1 TO 4 INCHES WILL FALL OVER MUCH OF THE FORECAST
AREA BY WEDNESDAY...INCLUDING THE RAINFALL FROM YESTERDAY AND LAST
NIGHT. SINCE THE PRECIPITATION WILL OCCUR OVER AN EXTENDED PERIOD OF
TIME...THE THREAT OF FLASH FLOODING WILL BE LOW. HOWEVER...RIVER
FLOODING IS EXPECTED WITH SEVERAL OF THE AREA TRIBUTARIES AND THE
MISSISSIPPI RIVER POSSIBLY SEEING AT LEAST MINOR TO MODERATE FLOODING
BY THE MIDDLE OF THE WEEK.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLOOD WATCH THROUGH THIS EVENING FOR BENTON-BUCHANAN-CEDAR-
CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON-
JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-
SCOTT-VAN BUREN-WASHINGTON.
IL...FLOOD WATCH THROUGH THIS EVENING FOR BUREAU-CARROLL-HANCOCK-
HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-PUTNAM-ROCK
ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FLOOD WATCH THROUGH THIS EVENING FOR CLARK-SCOTLAND.
&&
$$
UPDATE...08
SYNOPSIS...11
SHORT TERM...11
LONG TERM...12
AVIATION...11
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
425 PM EDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 425 PM EDT MON APR 28 2014
19Z SFC ANALYSIS SHOWS THE DEEP AREA OF LOW PRESSURE SPINNING OVER THE
CENTRAL PLAINS. THIS SYSTEM/S WARM FRONT IS LAID OUT TO THE EAST JUST
NORTH OF THE OHIO RIVER. THIS PLACES EAST KENTUCKY WELL INTO TO THE
BROAD WARM SECTOR AND THUS RIPE FOR PERIODS OF SHOWERS AND
THUNDERSTORMS. EARLIER SUNSHINE IN THE FAR EAST LED TO WARMER
TEMPERATURES AND THIS IS HELPING STORMS SUSTAIN THEMSELVES NEAR THE
VIRGINIA BORDER. MEANWHILE...MUCH COOLER TEMPERATURES IN THE REST OF
THE CWA...DUE TO THE COLD POOL FROM THE EARLIER MCS TO THE WEST AND
MORE EXTENSIVE CLOUD COVER...HAS KEPT THE CONVECTION TAME THERE...FOR
NOW. DEWPOINTS REMAIN IN THE UPPER 50S TO LOWER 60S THROUGHOUT THE
AREA WHILE THE WINDS ARE RATHER VARIABLE WITH OCCASIONAL SOUTH TO
SOUTHWEST GUSTS TO 20 KTS...OUTSIDE OF STORMS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP UPPER LOW
TRANSITIONING INTO THE MID MISSISSIPPI VALLEY TONIGHT AND SPREADING
WAVES OF ENERGY CLUSTERS OVER EAST KENTUCKY AS IT DOES SO. THE BROAD
CLOSED LOW THEN LIFTS NORTH INTO THE WESTERN GREAT LAKES LATER
TUESDAY WHILE ONE LAST BATCH OF ENERGY RIDES THROUGH KENTUCKY DURING
THE NIGHT. GIVEN THE MODEL AGREEMENT...HAVE FOLLOWED A BLEND WITH A
LEAN TOWARD THE NAM12 AND HRRR FOR THE NEAR TERM DETAILS.
SENSIBLE WEATHER WILL FEATURE PERIODS OF SHOWERS AND THUNDERSTORMS
THROUGH THE SHORT TERM PORTION OF THE FORECAST. EACH NEW CLUSTER WILL
HAVE A CHANCE TO BECOME SEVERE DEPENDING ON THE INSTABILITY LEFT
BEHIND BY EARLIER STORMS AND CLEARING THAT CAN TAKE PLACE DURING THE
DAYLIGHT HOURS. THIS WAS WHAT SET UP THE STORMS FOR FAR EAST KENTUCKY
THIS AFTERNOON. EXPECT THESE TO CLEAR OUT OVER THE NEXT HOUR OR SO.
ABOUT THAT TIME...THE NEXT ROUND OF STORMS SHOULD BE DEVELOPING IN
SOUTH CENTRAL KENTUCKY AND WORKING TO MOVE NORTHEAST INTO EAST
KENTUCKY LATER IN THE EVENING. STORMS WILL CONTINUE THROUGH THE NIGHT
AS THE SET UP REMAINS INTACT. THE ACTUAL COVERAGE AND TIMING OF
THESE LATER EVENTS WILL BE PARTIALLY DEPENDENT ON THE EARLIER
EVOLUTION SO IT BECOMES HARDER TO PIN POINT. DO EXPECT THIS OVERNIGHT
WAVE OF STORMS TO MOVE ON THROUGH TOWARDS DAWN AND EARLY TUESDAY
MORNING IN FAR EASTERN PARTS OF THE STATE. ISOLATED TRAINING AND
HEAVY RAINS WILL BE POSSIBLE THROUGH THE NIGHT...POSSIBLY RESULTING
IN A FLASH FLOOD THREAT. THIS WILL CONTINUE TO BE HIGHLIGHTED IN THE
HWO AND SPS. AFTER A MIDDAY LULL ON TUESDAY...LOW TOPPED STORMS
SHOULD DEVELOP ACROSS EAST KENTUCKY BY LATE AFTERNOON WITH A
CONTINUING POTENTIAL TO BE SEVERE...INCLUDING A SLIGHT TORNADO THREAT
DUE TO FAVORABLE WIND SHEAR IN THE LOW LEVELS. THE MORE SUNSHINE THAT
MANAGES TO OCCUR DURING THE DAY TUESDAY WILL PLAY INTO HOW STRONG THE
STORMS COULD BECOME. THE SYSTEM/S COLD FRONT WILL SWEEP THROUGH LATER
THAT NIGHT AND SHOULD END THE RISK FOR SEVERE WEATHER AND ALSO WIND
DOWN THE THUNDER CHANCES.
USED THE CONSSHORT AS A STARTING POINT FOR THE GRIDS THROUGH THE NEXT
24 HOURS WITH THE CONSALL THEREAFTER. MADE ONLY MINOR ADJUSTMENTS TO
THE NUMBERS MAINLY TO CAPTURE THE CURRENT CONDITIONS AND TRENDS. AS
FOR POPS...ENDED UP ON THE HIGH SIDE OF ALL GUIDANCE THROUGH THE
FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 28 2014
MODELS REMAIN IN GOOD AGREEMENT WITH THE EVOLUTION OF THE UPPER AIR
PATTERN THROUGH THE MIDDLE AND END OF THE WEEK. THE LARGE UPPER LOW
OVER THE UPPER MS VALLEY WILL MAKES ITS WAY INTO THE GREAT LAKES
REGION BY THURSDAY...AND THEN ON INTO CANADA BY FRIDAY. AFTER THIS
THERE WILL BE OCCASIONAL SHORT WAVE TROUGHS PASSING BY AS A MEAN
LONG WAVE TROUGH REMAINS OVER THE EASTERN PART OF THE U.S. INTO
EARLY NEXT WEEK. IT DOES APPEAR THE FLOW WILL BE SLOWLY DEAMPLIFYING
THOUGH.
HIGHER RAIN AND THUNDERSTORMS CHANCES WILL LINGER INTO THE DAY
WEDNESDAY...MAINLY IN THE EASTERN PART OF THE FORECAST AREA. THE
DEEPER MOISTURE AND FORCING WILL BE EXITING THE AREA ON
WEDNESDAY...BUT MAINLY DIURNAL SHOWER CHANCES WILL LINGER INTO THE
WEEKEND. WITH A MEAN TROUGH OVER THE AREA TEMPERATURES WILL ALSO
AVERAGE BELOW NORMAL FOR THE END OF THE WEEK AND INTO THE WEEKEND.
TEMPERATURES WILL BE WARMING LATE IN THE WEEKEND AND INTO EARLY NEXT
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM EDT MON APR 28 2014
VFR CONDITIONS WILL CONTINUE FOR MUCH OF THE AREA THIS AFTERNOON...
OUTSIDE OF A ZONE OF STRONGER STORMS FOR THE NEXT FEW HOURS LOCATED
SOUTH AND EAST OF THE TAF SITES. THE NEXT STRONG TO SEVERE CLUSTER OF
SHOWERS AND STORMS MOVE IN AROUND 00Z. HAVE GONE WITH MVFR TO IFR
CEILINGS AND VISIBILITY THROUGH MUCH OF THE NIGHT AND INTO EARLY
TUESDAY MORNING WITH THIS OVERNIGHT ROUND OR TWO OF STORMS.
CONDITIONS IMPROVE TEMPORARILY INTO MIDDAY TUESDAY WITH VFR CIGS
AND VIS EXPECTED FOR A TIME. WINDS WILL BE OUT OF THE SOUTH FOR MUCH
OF THE PERIOD WITH GUSTS UP TO 20 KTS POSSIBLE...OUTSIDE OF
THUNDERSTORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
423 PM EDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 423 PM EDT MON APR 28 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH FROM THE NRN ROCKIES TO THE CENTRAL PLAINS AND MID MS
VALLEY. DOWNSTREAM A RIDGE EXTENDED FROM THE MID ATLANTIC THROUGH
THE ERN LAKES TO WRN HUDSON BAY. AT THE SFC...GUSTY EAST WINDS
PREVAILED AS A RESULT OF A TIGHT PRES GRADIENT BETWEEN STRONG HIGH
PRES OVER HUDSON BAY AND A LOW OVER ERN NEBRASKA. A BAND OF RAIN
OVER NRN WI SUPPORTED BY 295K-300K ISENTROPIC LIFT WAS MAKING VERY
SLOW PROGRESS IN LIFTING TO THE NORTH AS IT ENCOUNTERS IT ENCOUNTERS
DRY EASTERLY FLOW (BELOW 800 MB) TO THE NORTH AND EAST...PER 12Z APX
SOUNDING.
SOME PCPN MAY DEVELOP ALONG THE WI BORDER THIS EVENING BUT SINCE IT
SHOULD BE RELATIVELY LIGHT...MAINLY SPRINKLES...ONLY CHANCE POPS
WERE INCLUDED. AS THE MID LEVEL LOW WOBBLES TO THE NORTHEAST AND A
SHORTWAVE LIFTS NORTH INTO UPPER MI...EXPECT WIDESPREAD PCPN TO
SPREAD INTO THE SOUTH LATE TONIGHT AND ACROSS THE REST OF THE CWA
TUE MORNING. THE PCPN IS EXPECTED TO TAPER OFF FROM SSE TO NNW BY
MID TO LATE AFTERNOON. THE REGION WILL FALL UNDER THE TROWAL REGION
NORTH OF THE MID/UPPER LOW...PER MODELS 310-320 THETA-E LAYER.
ALTHOUGH MOST AREAS SHOULD SEE QPF AMOUNTS IN THE 0.50 TO .75 INCH
RANGE...THE STRONGEST LIFT AND MOISTURE INFLOW IS EXPECTED OVER THE
SE CWA WHERE QPF COULD EXCEED AN INCH THROUGH TUE. UPSLOPE NE FLOW
INTO N CNTRL UPPER MI COULD ALSO SUPPORT RELATIVELY HIGHER PCPN
AMOUNTS.
UNCERTAINTY REMAINS WITH THE PCPN TYPE OVER THE HIGHER TERRAIN OF
THE WRN HALF OF UPPER MI. THE 12Z NAM LOW LEVEL THICKNESS AND
WET-BULB ZERO HEIGHTS SUGGEST THAT SNOW MAY BE THE PREDOMINATE PCPN
TYPE OVER THE INTERIOR...AND ESPECIALLY OVER THE HIGHER TERRAIN OF
THE WRN THIRD TOWARD IWD. EVEN WITH THE HIGH QPF AMOUNTS...VERY LOW
SLR VALUES AND RELATIVELY WARM ROAD SURFACES SHOULD MINIMIZE ANY
ACCUMULATIONS WITH SNOW AMOUNTS ONLY TO AROUND AN INCH EXPECTED ON
GRASSY OR SNOW COVERED AREAS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 423 PM EDT MON APR 28 2014
MUCH OF THE LONG TERM FORECAST WILL DEAL WITH THE UPPER LOW
CURRENTLY OVER THE CENTRAL CONUS THAT WILL GRADUALLY LIFT NORTHEAST
THROUGH MUCH OF THE REST OF THE WORK WEEK. THE STRONGEST WAVE OF
PRECIPITATION WILL MOVE NORTH THROUGH THE AREA ON TUESDAY AND
SHOULD BE SITUATED OVER WESTERN LAKE SUPERIOR AND THE WESTERN THIRD
OF THE U.P. AT THE START OF THE LONG TERM PERIOD. THIS WILL CONTINUE
TO ROTATE NORTHWEST TUESDAY NIGHT AND LEAD TO A LITTLE BIT OF A
BREAK ON THE PRECIPITATION FOR TUESDAY EVENING OVER THE
CENTRAL/EAST. AS THE SURFACE LOW MOVES UP INTO THE
GREAT LAKES REGION...A MID LEVEL TROUGH WILL SLIDE NORTH THROUGH
THE AREA LATE TUESDAY NIGHT THROUGH WEDNESDAY. THINK THE
HEAVIEST PRECIP WOULD BE OVER THE EAST THIRD...BUT STILL WOULD
EXPECT SCATTERED/NUMEROUS SHOWERS OVER THE WEST/CENTRAL. BETTER DEEP
MOISTURE SHIFTS OVER THE WESTERN LAKE AFTER THAT...AND WILL LIKELY
LEAD TO A MORE SCATTERED NATURE TO THE SHOWERS. THIS WILL CONTINUE
THROUGH THE FIRST PART OF THE WEEKEND AS THE AS THE UPPER LOW SPINS
AND BROADENS/WEAKENS. THUS...WILL CONTINUE TO SHOW A GRADUAL
DECREASING TREND TO THE POPS. WITH THE POTENTIAL FOR WEAK
DISTURBANCES ROTATING THROUGH...THERE MAY BE PERIODS WHERE POPS NEED
TO BE BUMPED UP...BUT PINNING THOSE DOWN AT THIS TIME IS TOO
DIFFICULT.
AS FOR PRECIP TYPE...SHOULD BE ENOUGH WARM AIR WRAPPING IN DURING
THE DAY TOMORROW TO CHANGE THE PRECIP OVER TO RAIN OVER MUCH OF THE
AREA BY TUESDAY EVENING (EXCEPT FOR A LINGERING MIX NEAR IRONWOOD).
THE WARM AIR CONTINUES TO MOVE WEST AROUND THE LOW (REMAINING AROUND
2-4C AT 850MB) THROUGH WEDNESDAY EVENING AND WILL KEEP EVERYTHING
AS RAIN. THEN AS THE FLOW STARTS TO BECOME A LITTLE MORE NORTHERLY
ON WEDNESDAY NIGHT AND INTO THURSDAY...TEMPERATURES ALOFT BEGIN TO
COOL FROM NORTHWEST TO SOUTHEAST ACROSS THE AREA AND COULD LEAD TO A
TRANSITION TO TO MORE OF A RAIN/SNOW MIX HEADING INTO
THURSDAY/FRIDAY. OPTED TO FOLLOW THE GENERAL IDEA SHOWN BY THE
1000-850MB THICKNESS AND WETBULB0 HEIGHTS THROUGH THE FORECAST
PERIOD SINCE IT WAS LARGELY DEALING WITH A NEAR SURFACE WARM
LAYER. DID PUT IN SOME FOG FOR THE FAVORED UPSLOPE HIGHER TERRAIN
LOCATIONS OF THE CENTRAL/NORTH-CENTRAL ON TUESDAY NIGHT INTO
WEDNESDAY WITH THE FAVORABLE EASTERLY UPSLOPE FLOW OF MOIST AIR.
ELSEWHERE...WOULD EXPECT IT TO BE JUST A LOW STRATUS DECK. ALL IN
ALL...LOOKS TO BE A COOL/CLOUDY/SHOWERY PERIOD THROUGH THE FIRST
HALF OF THE WEEKEND.
UPPER TROUGH/LOW FINALLY SHIFTS EAST OF THE AREA FOR THE SECOND
HALF OF THE WEEKEND...BUT MODELS DIFFER ON EVOLUTION OF THE UPPER
LEVEL PATTERN AT THAT POINT. THE GENERAL IDEA IS FOR MORE ZONAL
FLOW OR WEAK UPPER LEVEL RIDGING TO DEVELOP OVER THE NORTH-CENTRAL
CONUS...WHICH SHOULD LEAD TO A LITTLE DRIER PERIOD THAN SEEN THIS
WEEK. THERE ARE HINTS IN THE 12Z GEM/GFS/ECMWF THAT A WEAK
DISTURBANCE WILL SHIFT EAST ACROSS THE AREA ON SUNDAY AND BRING SOME
SHOWERS. OTHERWISE...MONDAY IS LOOKING LIKE IT MAY END UP DRY WITH
THE WEAK UPPER RIDGE SHIFTING CLOSER TO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 135 PM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL UNTIL LATE TONIGHT. THERE COULD BE SOME
INTERMITTENT LIGHT RAIN/SPRINKLES AT KIWD THIS MORNING BUT OTHERWISE
MID CLOUDS AND VFR CONDITIONS WILL PREVAIL. INCREASING MOISTURE AHEAD
OF A WARM FRONT WILL BRING AN INCREASING CHANCE OF RAIN RAIN LATE
TONIGHT AT ALL TAF SITES AS CIGS LOWER TO MVFR. A MIX OF RAIN AND
SNOW WILL MOVE IN DURING THE MORNING WITH CIGS LIKELY LOWERING INTO
THE IFR RANGE WITH VSBY REMAINING MVFR. THE BEST CHANCE FOR SNOW
WILL BE OVER THE WEST TOWARD CMX AND ESPECIALLY IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT MON APR 28 2014
EAST TO NORTHEAST GALES ARE EXPECTED TO CONTINUE OVER THE WRN
PORTION OF LAKE SUPERIOR THROUGH TUE INTO TUE EVENING AS A RESULT OF
THE STRONG PRES GRADIENT BTWN A DEEP LOW OVER ERN NEBRASKA AND A
STRONG HIGH OVER HUDSON BAY. ENE GALES TO 35 KNOTS ARE ALSO POSSIBLE
CENTRAL LAKE SUPERIOR TUE BUT SINCE THERE WAS STILL UNCERTAINTY
WHETHER THE 30 KNOTS WINDS WILL INCREASE TO GALES...THE WATCH WAS
RETAINED FOR THIS LOCATION. THE WINDS WILL DIMINISH TUE EVENING AS
THE LOW LIFTS TO THE NORTH TOWARD THE WRN GREAT LAKES AND THE PRES
GRADIENT WEAKENS. HOWEVER WINDS TO 30 KNOTS ARE STILL EXPECTED UNTIL
LATE TUE NIGHT. WINDS ARE EXPECTED TO DROP OFF TO 25 KNOTS OR LESS
FROM WED INTO FRI AS THE LOW FILLS AND REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 423 PM EDT MON APR 28 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON
RIVER NEAR NAHMA JUNCTION. AT LEAST THROUGH TUESDAY MORNING THESE
RIVERS ARE NOT EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER
RIVERS WILL START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE
SYSTEM AND WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL
LIQUID EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES
BY THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE
WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE
FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF
HIGHER QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS
WEEK.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
LSZ264>266.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ TUESDAY FOR LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
HYDROLOGY...SRF/TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
136 PM EDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 511 AM EDT MON APR 28 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A NEGATIVE TILT MID/UPPER
LEVEL TROUGH FROM THE NW CONUS THROUGH THE CENTRAL PLAINS WITH A
CLOSED LOW OVER NEBRASKA. DOWNSTREAM A RIDGE EXTENDED FROM THE SE
CONUS THROUGH WRN LAKES INTO MANITOBA. AT THE SFC...A BRISK ERLY
FLOW PREVAILED THROUGH THE NRN LAKES BETWEEN HIGH PRES OVER HUDSON
BAY AND A DEEP LOW OVER ERN NEBRASKA. ISENTROPIC ASCENT AS NOTED ON
THE 295K SFC HAS PRODUCED SEVERAL BANDS OF LIGHT PCPN OVER UPPER MI
THIS MORNING BUT THIS PCPN HAS FALLEN MAINLY AS JUST
SPRINKLES/FLURRIES AS IT ENCOUNTERS VERY DRY AIR BELOW 750 MB.
TODAY...MODELS CONSISTENT SHOWING SYSTEM OVER ERN NEBRASKA STALLING
AND BEGINNING TO OCCLUDE TODAY. MODELS SHOW WEAKENING ISENTROPIC
ASCENT OVER UPR MI AND A LACK OF 850-700 MB MOISTURE ADVECTION INTO
THE REGION. THIS FACT ALONG WITH MID-LVL RDG GENERALLY STAYING IN
PLACE SHOULD KEEP MUCH OF THE CWA DRY TODAY. INCREASING 850-700 MB
MOISTURE ADV AND ISENTROPIC ASCENT COULD BRING IN A BETTER CHC OF
RAIN TOWARD 00Z THIS EVENING OVER MAINLY FAR SCNTRL CWA.
TONIGHT...MODELS SHOW MORE SUBSTANTIAL SHORTWAVE LOBE ROTATING
NORTHWARD AHEAD OF PLAINS CLOSED LOW WHICH IN TURN WILL PROPEL 850
MB WARM FRONT NORTHWARD INTO THE SE CWA LATE TONIGHT. INCREASING
ISENTROPIC ASCENT AND 850-700 MB MOISTURE ADVECTION SPREADING IN
FROM THE SSE AHEAD OF THE WARM FRONT WILL BRING INCREASING RAIN CHCS
INTO SCNTRL CWA THIS EVENING SPREADING INTO THE REST OF THE SE HALF
OF THE CWA OVERNIGHT TONIGHT. THICKNESS VALUES AND SOUNDINGS SUGGEST
SNOW MAY MIX WITH RAIN OVER NCNTRL AND NW CWA LATE TONIGHT BUT PCPN
SHOULD BE LIGHT THAT ANY SNOW AMTS WILL HAVE LITTLE IMPACT ON TRAVEL.
MODEL QPF INDICATES SCNTRL CWA COULD SEE FROM .25 TO PERHAPS .75 OF
AN INCH OF RAINFALL TONIGHT WHICH WILL ADD TO RUNOFF FOR AREA STREAMS
AND RIVERS INTO MIDWEEK.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 358 AM EDT MON APR 28 2014
FOCUSED ATTENTION ON TUE-WED NIGHT TIME FRAME AS MOST SIGNIFICANT
PRECIP IS EXPECTED DURING THAT TIME.
THE SETUP FOR MID WEEK IS QUITE INTERESTING ACROSS THE CONUS AS A
DEEP CLOSED UPPER LOW IS OVER THE CENTRAL CONUS...BORDERED ON THE
W...N AND E BY AMPLIFIED UPPER RIDGING. ALSO...AT THE START OF THE
LONG TERM /12 TUE/...THE UPPER LOW WILL BE ABSORBING A WEAK UPPER
LOW THAT ORIGINATED OVER QUEBEC. THE SYSTEM WILL BE QUITE WRAPPED
UP...WITH GREAT MOISTURE TRANSPORT FROM BOTH THE GULF OF MEXICO AND
THE ATLANTIC THAT FOCUSES OVER THE LOWER GREAT LAKES BEFORE
WRAPPING W ACROSS THE CWA AND EVENTUALLY TO THE W OF THE LOW /WHICH
IS OVER IA AT 12Z TUE/. PRECIP TUE WILL BE PRIMARILY FORCED BY
50-60KT 900-700MB WINDS...RESULTING IN GOOD MOISTURE TRANSPORT IN
THIS LAYER AS WELL AS STRONG ISENTROPIC ASCENT AS ISENTROPIC
SURFACES INCREASE IN HEIGHT BY AROUND 1KM FROM UPSTREAM TO
DOWNSTREAM ACROSS THE CWA. PWAT VALUES WILL BE 0.75-1.00 INCHES...OR
GENERALLY 150-200 PERCENT OF NORMAL. ANOTHER SIGNIFICANT FORCING
MECHANISM IS A SHORTWAVE THAT MODELS SHOW MOVING ACROSS THE CWA
TUE...WHICH LEADS TO STEEP 700-500MB LAPSE RATES OF JUST OVER 7C/KM.
ADDITIONALLY...THE LEFT EXIT REGION OF AN UPPER JET WILL BE ACROSS
THE CWA. ALL THESE INGREDIENTS COME TOGETHER TO PRODUCE SIGNIFICANT
QPF AMOUNTS FROM THE MODELS LATE MON NIGHT INTO TUE. THE MOST PRECIP
SHOULD FALL NEAR LAKE MICHIGAN WHERE THE BEST FORCING AND MOISTURE
IS EXPECTED. EVEN THE LOWER RES MODELS /THAT TYPICALLY DO NOT
PERFORM AS WELL IN THIS TYPE OF SITUATION/ HAVE UP TO AN INCH OF QPF
NEAR LAKE MICHIGAN...WHILE THE NAM HAS THE MOST QPF AT 2.25 INCHES.
WILL GO WITH A CONSENSUS APPROACH OF GFS/ECMWF AND REGIONAL GEM
/WHICH HAS UP TO 1.85 INCHES/...WHICH INCORPORATES MON NIGHT /SHORT
TERM/. THE ECMWF/GFS HAVE THE BEST PRECIP LATE MON NIGHT INTO TUE
MORNING...WHILE THE NAM HAS THE BEST PRECIP ON TUE. THE REGIONAL GEM
IS BETWEEN THE NAM AND GFS/ECMWF. A COMPLICATING FACTOR TO THIS TIME
FRAME IS THAT MODEL TEMP PROFILES FAVOR PRECIP TO BE SNOW OVER WRN
UPPER MI AND RAIN NEAR LAKE MICHIGAN AND E...WITH A MIX BETWEEN. DUE
TO SFC TEMPS BEING NEAR OR ABOVE FREEZING AND STRONG SOLAR EFFECTS
THIS TIME OF YEAR...ACCUMULATIONS ON PAVED SURFACES SHOULD BE
MINIMAL...BUT GRASSY SURFACES OVER THE HIGHER TERRAIN OF WRN UPPER
MI COULD SEE 2-3 INCHES OF SNOW. GIVEN VERY MINIMAL EXPECTED IMPACTS
TO TRAVEL...WILL CONTINUE TO NOT MENTION SNOW IN THE HWO. DEPENDING
ON EXACT PRECIP AMOUNTS...COULD SEE SOME SIGNIFICANT RISES ON AREA
RIVERS.
ANOTHER SHOT AT GOOD ISENTROPIC ASCENT AND A STRONG SHORTWAVE ARE
SHOWN BY MODELS FOR WED AS THE UPPER LOW CONTINUES TO WEAKEN AND
BEGINS MOVING NE TOWARD THE CWA. SIGNALS FOR PRECIP AMOUNTS AND
TRENDS ARE A LOT MORE MUDDLED ON WED INTO WED NIGHT AS THE CWA WILL
BE MORE REMOVED FROM THE BEST MOISTURE TRANSPORT...WHICH WILL BE
MORE FOCUSED E AND N OF THE CWA. THINK THAT MUCH OF THE CWA WILL SEE
PRECIP...WITH POTENTIAL FOR UP TO AN INCH OF ADDITIONAL PRECIP
DURING THIS TIME PERIOD. USED A BROAD CONSENSUS OF GUIDANCE DURING
THIS PERIOD.
THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE SLOWLY NE INTO LATE
WEEK BEFORE ADDITIONAL UPPER LEVEL ENERGY MOVES INTO THE REGION LATE
THIS WEEK INTO THE WEEKEND...LEADING TO CONTINUED WET WEATHER...BUT
AMOUNTS WILL BE LOWER THROUGH THE REST OF THE WEEK. USED A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 135 PM EDT MON APR 28 2014
VFR CONDITIONS WILL PREVAIL UNTIL LATE TONIGHT. THERE COULD BE SOME
INTERMITTENT LIGHT RAIN/SPRINKLES AT KIWD THIS MORNING BUT OTHERWISE
MID CLOUDS AND VFR CONDITIONS WILL PREVAIL. INCREASING MOISTURE AHEAD
OF A WARM FRONT WILL BRING AN INCREASING CHANCE OF RAIN RAIN LATE
TONIGHT AT ALL TAF SITES AS CIGS LOWER TO MVFR. A MIX OF RAIN AND
SNOW WILL MOVE IN DURING THE MORNING WITH CIGS LIKELY LOWERING INTO
THE IFR RANGE WITH VSBY REMAINING MVFR. THE BEST CHANCE FOR SNOW
WILL BE OVER THE WEST TOWARD CMX AND ESPECIALLY IWD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 511 AM EDT MON APR 28 2014
EAST TO NORTHEAST WINDS WILL INCREASE TONIGHT AS LOW PRESSURE
DEEPENS OVER THE PLAINS. EXPECT ENE GALES TO 35KTS OVER MUCH OF WRN
LAKE SUPERIOR INTO TUE MORNING. THERE IS ALSO A CHANCE FOR ENE GALES
TO 35 KNOTS OVER CENTRAL LAKE SUPERIOR FOR LATE TONIGHT INTO TUE SO
HAVE ISSUED A GALE WATCH FOR LSZ264-266 WINDS SHOULD GRADUALLY
DIMINISH LATE TUE AS THE LOW PRESSURE SYSTEM LIFTS TO THE NORTH
TOWARD THE WRN GREAT LAKES AND THE PRES GRADIENT WEAKENS. HOWEVER
WINDS TO 30 KNOTS ARE STILL EXPECTED INTO TUE EVENING. WINDS ARE
EXPECTED TO DROP OFF TO 25 KNOTS OR LESS FROM WED INTO FRI AS THE
LOW FILLS AND REMAINS NEAR UPPER MICHIGAN.
&&
.HYDROLOGY...
ISSUED AT 358 AM EDT MON APR 28 2014
RUNOFF FROM RECENT SNOWMELT AND RAINFALL CONTINUES TO FLOW THROUGH
THE GROUND...SO DESPITE THE RECENT COOLER WEATHER...SOME AREA
STREAMS AND RIVERS REMAIN HIGH. LOCATIONS THAT ARE STILL NEAR OR
ABOVE BANKFULL AT THIS TIME INCLUDE THE STURGEON RIVER NEAR
CHASSELL...THE PAINT RIVER NEAR CRYSTAL FALLS AND THE STURGEON RIVER
NEAR NAHMA JUNCTION. AT LEAST THROUGH TONIGHT THESE RIVERS ARE NOT
EXPECTED TO REACH FLOOD STAGE...BUT THESE AND OTHER RIVERS WILL
START TO RISE AGAIN LATER THIS WEEK AS A LOW PRESSURE SYSTEM AND
WIDESPREAD PRECIPITATION AFFECT UPPER MICHIGAN. TOTAL LIQUID
EQUIVALENT PRECIPITATION AMOUNTS COULD REACH 1 TO 2 INCHES BY
THURSDAY. THE PRECIPITATION WOULD ADD TO THE FLOOD RISK. WHILE
WIDESPREAD AND AREAL FLOODING IS NOT EXPECTED...RFC ENSEMBLE
FORECASTS DO SHOW SIGNIFICANT RISES ON A FEW OF THE RIVERS IF HIGHER
QPF FROM THE MODELS VERIFIES. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD MONITOR RIVER LEVELS THIS WEEK.
REPORTS INDICATE LITTLE ICE REMAINS ON AREA RIVERS...SO THE ICE JAM
FLOODING THREAT HAS GREATLY DIMINISHED. THE ONLY EXCEPTION MIGHT BE
AT THE MOUTHS OF RIVERS THAT FLOW INTO THE GREAT LAKES WHERE
SIGNIFICANT ICE REMAINS AT THE SHORE OR JUST OFFSHORE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
LSZ264>266.
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ TUESDAY FOR LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...JLB
MARINE...VOSS
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1258 PM EDT MON APR 28 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 325 AM EDT MON APR 28 2014
AN EXPANSIVE AND STRONG SYSTEM CENTERED ACROSS THE CENTRAL PLAINS
STATES WILL DRIVE RAINFALL INTO THE AREA AHEAD OF AN ASSOCIATED
FRONTAL SYSTEM TO OUR SOUTH. COOL AND WINDY CONDITIONS CAN BE
EXPECTED TODAY WITH AN INCREASING CHANCE OF RAIN. RAIN WILL CONTINUE
INTO EARLY TUESDAY BEFORE THE RAIN MOVES NORTH AND A SHORT PERIOD OF
WARMER AIR MOVES IN ACROSS THE AREA. ADDITIONAL SHOWERS AND STORMS
WILL BE POSSIBLE TUESDAY AND WEDNESDAY AS ADDITIONAL WAVES OF LOW
PRESSURE MOVE THROUGH THE AREA. COOLER CONDITIONS WILL THEN RETURN
FOR LATE THIS WEEK ALONG WITH A CONTINUED CHANCE OF RAIN SHOWERS.
&&
.UPDATE...
ISSUED AT 1256 PM EDT MON APR 28 2014
FORECASTS WILL BE UPDATED TO ACCOUNT FOR LESS RAIN THIS AFTERNOON.
THE BAND OF RAIN CONTINUES TO DIMINISH...SO I LOWERED POPS. SOME
BREAKS IN THE CLOUDS SHOWING UP AS WELL...THUS I FEATURED LESS
CLOUD COVER AS WELL. WITH ADDED HEATING...MIXING HEIGHTS WILL
INCREASE. THUS IT WILL REMAIN WINDY THROUGH THE AFTERNOON.
UPDATE ISSUED AT 1056 AM EDT MON APR 28 2014
WILL KEEP THE WIND ADVISORY GOING. WHILE OBS ARE MOSTLY BELOW
CRITERIA...THE MODELS SUGGEST MIXING HEIGHTS WILL INCREASE EARLY
THIS AFTERNOON AS THE LOW LEVEL JET STRENGTHENS. WE ARE ALSO
SEEING SOME POWER OUTAGES SHOWING UP ON THE CONSUMERS WEBSITE.
THE BAND OF SHOWERS MOVING IN FROM THE SOUTH CONTINUES TO WEAKEN.
WHILE MOST LOCATIONS WILL SEE SOME PRECIPITATION...WHAT DOES FALL
TH IS AFTERNOON SHOULD BE LIGHT. SO I FEATURES LIGHT RAIN
SHOWERS...AND TONED BACK THE THUNDER WORDING. MODELS SHOWING NO
INSTABILITY THROUGH 00Z TUE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
THE MAIN CHANGE WITH THIS FCST PACKAGE IS TO EXPAND THE WIND
ADVISORY TO THE EAST THROUGH THE REMAINDER OF THE CWFA FOR TODAY.
OTHERWISE...THE FCST REMAINS MAINLY ON TRACK WITH A SLIGHTLY SLOWER
TREND TO THE RAIN MOVING IN FOR TODAY.
REGARDING THE EXPANSION OF THE WIND ADVISORY FIRST...WINDS REMAIN
RATHER BRISK AND THIS EARLY MORNING HOUR ACROSS THE CWFA. SOME GUSTS
OF AROUND 30 KNOTS ARE ALREADY OCCURRING THIS MORNING...AND THIS
WILL ONLY INCREASE DURING THE DAYLIGHT HOURS AS THE GRADIENT
TIGHTENS MORE AND AS DIURNAL MIXING WILL HELP TO BRING SOME OF THE
STRONGER WINDS DOWN FROM ALOFT. IT SEEMS THAT 40 KNOTS SHOULD BE
PRETTY EASY TO MIX DOWN...EVEN IN A WAA PATTERN.
AS FAR AS THE RAINFALL IS CONCERNED...THE TREND OVER THE PAST 24
HOURS IS THAT OF A SLOWER ONE WITH THE FEED OF DRY AIR COMING IN ON
THE BRISK ERLY WINDS AND HELPING TO DIMINISH MOST ALL PCPN TRYING TO
MOVE IN. THE UPPER RIDGE AXIS THAT IS ONLY SLOWLY CRAWLING EASTWARD
ACROSS THE CWFA IS FAR ENOUGH EAST AT THIS TIME THAT ENOUGH MOISTURE
TRANSPORT IS OCCURRING AND A COUPLE OF SPRINKLES/LIGHT SHOWERS ARE
OCCURRING ACROSS THE FAR SW CORNER OF THE CWFA. WE DO EXPECT THAT
PCPN WILL BE ON THE INCREASE TODAY FROM SW TO NE AS THE UPPER LOW
ROTATES A LITTLE CLOSER. THUNDER IS STILL POSSIBLE ACROSS THE FAR
SOUTH THIS AFTERNOON AS SLIGHTLY NEGATIVE ELEVATED LI/S MOVE UP INTO
THE AREA. SEVERE WX IS NOT EXPECTED AT THIS TIME WITH NO SFC
INSTABILITY EXPECTED THROUGH TONIGHT.
THE BEST THREAT OF RAIN SHOWERS AND STORMS LOOKS TO COME THIS
EVENING AND INTO THE OVERNIGHT HOURS. THE BEST MOISTURE AXIS PASSES
FROM SOUTH TO NORTH DURING THIS TIME FRAME...OUT AHEAD OF THE
OCCLUDED FRONT. WE CONTINUE TO EXPECT LITTLE THREAT OF SEVERE STORMS
TONIGHT ONCE AGAIN AS THE INSTABILITY WILL ONCE AGAIN BE ELEVATED.
THE RAIN CHANCES WILL THEN DIMINISH LATE TONIGHT AND EARLY TUE
MORNING AS THE MOISTURE TRANSPORT AND LLJ PEEL OFF TO THE EAST OF
THE STATE.
WE CONTINUE TO LOOK FOR A BRIEF WARM UP FOR THE DAY ON TUE WITH 70
DEGREE TEMPERATURES LOOKING MORE LIKELY. THE FRONT WILL BE NEAR THE
SRN STATE BORDER AT 12Z ON TUE. THE UPPER LOW COMING IN FROM THE
WEST WILL PUSH THE FRONT NORTH THROUGH THE AREA. EVEN THOUGH IT WILL
NOT BE THE TRUE WARM SECTOR...H850 TEMPS ARE STILL VERY MILD...AND
WILL WE TAP THAT WARMTH AS THE DRY SLOT MOVES IN AND WE GET SOME
SUN. H850 TEMPS AROUND +10 C WILL SUPPORT MANY LOCATIONS HITTING 70.
IT DOES LOOK LIKE LATE IN THE AFTERNOON WE WILL SEE CONVECTION TRY
TO FIRE OVERHEAD AS A WAVE ROTATES AROUND THE UPPER LOW AND MOVES
TOWARD THE AREA.
THERE IS SOME CONCERN WITH CONVECTION FIRING ON TUE AFTERNOON AS
STRONG JET STREAM WINDS WILL STILL BE OVERHEAD ACROSS SE LOWER.
THIS WILL PROVIDE FOR GOOD SHEAR IN THE DEEP LAYER. MUCH BETTER
INSTABILITY /LI/S OF -6 TO -8C/ WILL BE FOUND FURTHER SE ALSO.
WE STAY RELATIVELY WARM THROUGH MOST OF WED AS THE LOW LEVEL COLD
AIR DOES NOT COME IN UNTIL LATE WED AFTERNOON AND WED EVENING. THIS
IS THE CASE AS THE UPPER LOW HELPS ANOTHER WAVE TOWARD THE AREA AND
THE FLOW AHEAD OF IT WILL CONTINUE TO SUPPORT WARM TEMPS UNTIL THE
LOW MOVES THROUGH LATE WED. SHOWERS AND STORMS WILL REMAIN POSSIBLE
AHEAD OF THIS WAVE FOR TUE NIGHT AND WED. WE WILL LIKELY NOT REACH
70 AGAIN...BUT WE SHOULD BE WELL INTO THE 60S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 AM EDT MON APR 28 2014
LITTLE QUESTION OCCASIONAL SHOWERS AND COOLER THAN NORMAL
TEMPERATURES WILL PREVAIL THROUGH SATURDAY AS WE REMAIN ON THE
CYCLONIC SIDE OF THE UPPER JET WITH A FAIR AMOUNT OF DEEP MOISTURE.
SOME QUESTION ARISES WHAT HAPPENS FROM SUNDAY AND BEYOND SO I KEEP
THE LOW CHANCE POP FOR SUNDAY BUT IT MAY BE WE ACTUALLY GET TO SEE
THE SUN ONCE AGAIN BY SUNDAY AS THE UPPER JET MAY FINALLY LIFT NORTH
OF LOWER MICHIGAN MY THEN.
MODEL CONTINUE TO BE IN GOOD AGREEMENT WITH THE CLOSED UPPER LOW
REMAINING IN PLACE INTO AS LEAST SATURDAY. THE 500 MB HEIGHT
ANOMALIES ARE ON THE ORDER OF 2-3 STD BELOW NORMAL INTO SATURDAY
OVER THE LOWER GREAT LAKES. 850 MB TEMPERATURES ARE 1 TO 2 STD BELOW
NORMAL INTO SATURDAY.
THE MODELS CONTINUE TO FEATURE THAT ARCTIC JET STREAK FEEDING INTO
THE SYSTEM FRIDAY INTO SATURDAY. THAT WILL MAINTAIN THIS PATTERN
INTO SATURDAY FOR SURE. FROM SUNDAY ON THERE IS A QUESTION OF
WHETHER ANOTHER PACIFIC SYSTEM CAN BREAK THROUGH THE WESTERN RIDGE
TO PUSH THIS PATTERN OUT OF THE WAY OR IF WE WILL CONTINUE TO SEE
MORE IN A SERIES OF NORTHERN STREAM OF SYSTEMS. I KEEP LOW CHANCE
POPS FOR SUNDAY JUST IN CASE THE LATER OCCURS.
AS FOR THE SHOWERS WEDNESDAY NIGHT THROUGH SATURDAY AFTERNOON...
GIVEN THE DEEP CYCLONIC FLOW...DEEP MOISTURE AND SATURATED DGZ PLUS
SURFACE CONVERGENCE ALONG THE LAKE MICHIGAN SHORE AREAS INTO
SATURDAY I HAVE TO BELIEVE WE WILL CONTINUE TO SEE LIGHT SHOWER
THROUGH THIS ENTIRE PERIOD. I HAVE CONTINUED THE LIKELY POPS INTO
FRIDAY AND HIGH CHANCE INTO SATURDAY. TEMPERATURES WILL BE BETWEEN 5
AND 10 DEGREES BELOW NORMAL THROUGH THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 741 AM EDT MON APR 28 2014
OUR MAJOR QUESTION IS WHEN WILL THE RAIN ARRIVE AND MORE THAN THAT
WHEN WILL THE MVFR/IFR CIGS/VSBY MOVE IN AS THE STORM TO OUR
SOUTHWEST SLOWLY MOVES TOWARD THE REGION. THE HUDSON BAY HIGH
CONTINUES TO FEED VERY DRY AIR FROM THE EAST AND IT WILL CONTINUE
TO ERROD THE RAIN AS MOVES INTO SOUTHWEST MICHIGAN. THIS IS NOT TO
SAY THERE WILL NOT BE SOME LIGHT RAIN SHOWERS BUT IT SEEMS THE
BULK OF THE SIGNIFICANT RAIN WILL LARGELY STAY NEAR AND SOUTH OF
INTERSTATE 94 TODAY (USING THE RAP13 MODEL AND HRRR ).
I DID BRING THE SHOWERS INTO THE AZO...BTL AND JXN BY LATE MORNING
BUT I DID NOT BRING THOSE SHOWERS INTO GRR...MKG AND LAN TILL LATE
AFTERNOON... EVEN THEN VSBY SHOULD BE VFR FOR THE MOST PART. I PUT
VCSH AT ALL THE TAF SITES DURING THE MID MORNING HOURS SINCE
SHOWERS WILL BE AROUND BUT VERY LIGHT (MOSTLY SPRINKLES).
THE MVFR CIGS/VSBY SHOULD REACH THE I-94 TAT SITES BY LATE
AFTERNOON THEN SPREAD INTO THE I-96 SITES AFTER 00Z. ANY
THUNDERSTORM ACTIVITY SHOULD HOLD OFF UNTIL TUESDAY.
&&
.MARINE...
ISSUED AT 1056 AM EDT MON APR 28 2014
GALE WARNING TO CONTINUE. SOME GUSTS OVER GALE FORCE ALREADY
OBSERVED. WINDS LIKELY TO INCREASE AS THE LOW LEVEL JET
STRENGTHENS AND MIXING HEIGHTS INCREASE.
&&
.HYDROLOGY...
ISSUED AT 241 PM EDT SUN APR 27 2014
I DOWNPLAYED THE QPF THROUGH TUE. THE DRY AIRMASS CURRENTLY IN
PLACE SHOULD ACT TO DELAY THE ARRIVAL OF THE SHOWERS. MODELS ARE
GENERALLY SHOWING A DIMINISHING TREND TO THE INITIAL BAND OF
SHOWERS DURING THE DAY ON MONDAY. STILL LOOKS LIKE ENOUGH RAIN TO
CAUSE RIVER RISES. ANOTHER BATCH OF RAIN TUE NIGHT INTO WED MAY BE
HEAVY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ037>040-043>046-
050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LMZ844>849.
&&
$$
UPDATE...MJS
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
412 PM CDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM CDT MON APR 28 2014
BIGGEST CONCERN IN THE SHORT TERM IS THE POTENTIAL FOR ACCUMULATING
SNOW LATE TONIGHT THROUGH TUESDAY AS A DEFORMATION BAND OF PRECIP
SETS UP SHOP OVER THE MPX AREA AND DOES NOT REALLY GO ANYWHERE UNTIL
WEDNESDAY.
SFC LOW AND VERTICALLY STACKED SYSTEM WAS CENTERED NEAR COLUMBUS...
NEB TO THE WEST OF OMAHA. DURING THIS PERIOD...THIS LOW WILL REMAIN
CUTOFF...WHICH MEANS IT WILL NOT BE GOING VERY FAR...MAKING IT TO
ABOUT THE IA/IL/WI BORDER BY 00Z WED. THIS WILL LEAVE US WITHIN A
WAA REGION TONIGHT...THAT WILL RATHER SEAMLESSLY TRANSITION INTO
DEFORMATION PRECIPITATION FOR TUESDAY.
AT THE START OF THIS PERIOD WE WILL HAVE A BRIEF RESPITE FROM THE
PRECIP WORK ACROSS MOST OF THE MPX CWA...THIS IS IN RESPONSE TO A
LOSS IN DEEP MOISTURE SHOWN BY THE GFS/NAM AND OTHER DETERMINISTIC
MODELS THAT IS REFLECTED IN THE HI-RES MODELS BY A LACK OF
PRECIPITATION GENERATION THROUGH ABOUT 6Z TONIGHT.
HOWEVER...CONTINUED WAA AND MOISTURE TRANSPORT WILL QUICKLY START TO
FILL IN THIS MOMENTARY BREAK THIS EVENING. FOR POP GRIDS...FOLLOWED
THE HRRR/MPXWRF FOR TRYING TO TIME THE LOWER POPS ACROSS THE AREA...
BEFORE BRINGING POPS BACK IN FROM EAST TO WEST AS DEEP MOISTURE
MAKES ITS RETURN AFTER 6Z.
GIVEN ALL OF THE CLOUD COVER...DO NOT EXPECT MUCH OF A DROP IN
TEMPERATURES TONIGHT. HOWEVER...AS THE DEFORMATION PRECIP STARTS TO
GET GOING TONIGHT...DYNAMIC COOLING OF THE ATMOSPHERE BENEATH THIS
BAND SHOWS CRITICAL TEMPS/THICKNESSES BECOMING COLD ENOUGH FOR
SNOW. LIKE THE IDEA OF THE SPC WRF FOR P-TYPE...WHICH MATCHES UP
NICELY WITH THE NAM/ECMWF. THIS SCENARIO SHOWS PRECIP STARTING TO
TURN OVER TO SNOW AFTER 9Z ACROSS CENTRAL MN. AS THE DEFORMATION
BAND GETS SETUP ACROSS MN TUESDAY MORNING...EXPECT THIS MIX OR JUST
SNOW TO BUILD SOUTH WITH THE LOW. WITHIN THE HEART OF THIS
DEFORMATION BAND...DYNAMIC COOLING MAY VERY WELL KEEP THE ATMOSPHERE
COLD ENOUGH TO KEEP THE P-TYPE AS ALL SNOW THROUGH THE DAY ON
TUESDAY. AT THE MOMENT...THERE IS GOOD MODEL AGREEMENT ON THIS
DEFORMATION BAND SETTING UP FROM AROUND THE CENTRAL MN/IA
BORDER...UP THROUGH MANKATO AND THE TWIN CITIES UP TOWARD THE
WESTERN TIP OF LAKE SUPERIOR. IT IS THIS REGION THAT COULD SEE
MAINLY SNOW TOMORROW IF THE COOLING FROM DYNAMIC LIFT WITH THE
DEFORMATION BAND IS STRONG ENOUGH. FOR NOW...BROUGHT TEMPS FOR
TOMORROW AFTERNOON WHERE THIS BAND IS EXPECTED TO SETUP DOWN INTO
THE MID 30S...COLD ENOUGH TO BRING A MENTION OF A NORTH-SOUTH
ORIENTED BAND OF RA/SN MIX THROUGH THE DAY ACROSS THE CENTER OF THE
MPX CWA. RIGHT NOW...HAVE A COUPLE INCHES OF ACCUMULATION UP AROUND
KANABEC COUNTY...BUT COULD CERTAINLY SEE MORE DEPENDING ON HOW MUCH
AND HOW LONG WE CAN THINGS COOL ENOUGH FOR SNOW. AT ANY RATE...WOULD
NOT BE AT ALL SURPRISED IF FOR MUCH OF THE DAY...FOLKS IN THE TWIN
CITIES ARE WATCHING THE FLAKES FLY AS OPPOSED TO RAIN FALL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 410 PM CDT MON APR 28 2014
-HIGH CONFIDENCE IN PERIODS OF LIGHT RAIN /MIXED WITH WET SNOW AT
TIMES/ ACROSS THE ENTIRE FORECAST AREA THROUGH THURSDAY.
-HIGH CONFIDENCE IN BELOW NORMAL TEMPS THROUGH THE EXTENDED
MN/WI WILL BE UNDER THE INFLUENCE OF A CLOSED UPPER LOW THROUGH
THURSDAY. PERSISTENT CLOUD COVER...BREEZY WINDS...AND PERIODS OF
LIGHT RAIN ARE EXPECTED UNTIL THE SYSTEM FINALLY LIFTS OFF TO THE
NORTHEAST ON FRIDAY. THE TROUGH CURRENTLY OFF THE COAST OF NOVA
SCOTIA WILL CONTINUE TO LIFT INTO THE NORTH ATLANTIC AND GET
ABSORBED BY THE LONG WAVE TROUGH OVER NEWFOUNDLAND. THIS WILL
ALLOW THE RIDGE OVER HUDSON BAY TO WEAKEN AND SLIDE EAST.
THEREFORE...THE UPPER LOW CURRENTLY PARKED OVER NEBRASKA WILL HAVE
ROOM TO LIFT NORTH AND ACTUALLY RETROGRADE BACK TO THE NORTHWEST
ON WEDNESDAY. AS A RESULT...WE HAVE DECIDED TO FORECAST 70-90%
RAIN FOR MOST OF THE FORECAST AREA THROUGH THURSDAY. THE RAIN MAY
CLEAR FOR SEVERAL HOURS AT A TIME OR BECOME LESS WIDESPREAD IN
COVERAGE DURING THIS STRETCH...BUT WE DON`T THINK MANY LOCATIONS
WILL GO 6-12 HOURS WITHOUT SEEING AT LEAST LIGHT RAIN. THE GOOD
NEWS FOR SWOLLEN DITCHES...RIVERS AND STREAMS WILL BE A TRANSITION
TO LIGHT RAIN WITH TIME WITH LITTLE CHANCE FOR THUNDER. MANY
LOCATIONS IN MN HAVE SEEN 0.30-0.75" EVERY 6 HOURS FOR THE PAST 36
HOURS. FOR WEDNESDAY AND THURSDAY...WE THINK QPF WILL BE MORE ON
THE ORDER OF 0.05-0.15" ON A 6-HOURLY BASIS.
EVEN BEYOND THE UPPER LOW EXITING THE FORECAST AREA...NORTHWEST
FLOW AND EMBEDDED SHORTWAVES KEEP THE CHANCE FOR LIGHT RAIN /OR
BRIEF PERIODS OF LIGHT SNOW IN THE MIX/ THROUGH THE WEEKEND. THE
PRECIP CHANCES BEYOND THURSDAY ARE MORE UNCERTAIN...BUT ONE THING
THAT ISN`T UNCERTAIN IS THE LIKELIHOOD OF COOLER THAN NORMAL
TEMPS. NORMAL HIGHS ARE IN THE LOWER TO MID 60S OVER THE NEXT WEEK
AND WE SHOULD REMAIN 10 TO 20 DEGREES BELOW THAT OVER THE NEXT 7
DAYS - CONFIRMED BY BOTH THE OPERATIONAL AND ENSEMBLE GUIDANCE
FROM THE GFS AND ECMWF.
.HYDRO...ENDURED THE HEAVIEST PCPN OF THE STORM LAST 48 HRS...AND
NOW ONTO LIGHTER AMOUNTS THOUGH PRETTY CONSISTENT FOR THE NEXT FEW
DAYS. SMALLER STREAMS/TRIBS WILL BEGIN TO SLOW THEIR RISES NEXT 24
HRS...REMAINING BELOW FS. WILL CONTINUE TO WATCH SAND CREEK/JORDAN
THOUGH EXPECT IT TO QUICKLY BACK OFF NOW THAT MAIN PCPN BAND HAS
MOVED NORTH. MAINSTEM RIVERS WILL CONTINUE SLOW RISE THROUGH THE
WEEK...WITH BANKFUL BECOMING POSSIBLE ALONG MISSISSIPPI N AND S OF
TWIN CITIES. HWVR...THREAT OF REACHING FS STILL MARGINAL AT BEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1248 PM CDT MON APR 28 2014
THREE MAIN CONCERNS THIS TAF PERIOD ARE THE PRECIP BREAK COMING UP
FROM THE SOUTH...HOW FAR WEST DO VFR CIGS OVER WI MAKE INTO
MN...AND P-TYPE LATE TONIGHT/TUE MORNING. SEEING WARMING OF CLOUD
TOPS COMING UP FROM THE SOUTH...AND GFS/NAM RH TIME CROSS SECTIONS
SHOWS THIS IS ASSOCIATED WITH A MOMENTARY LOSS IN DEEP
MOISTURE...WHICH SUPPORTS THE BRIEF DRYING NOTED IN THE HIGH RES
MODELS. THEREFORE...FOLLOWED THE HRRR AND OTHER HIGH RES MODELS
WITH BRINGING A BREAK IN THE FALLING PRECIP THIS EVENING...BEFORE
EVERYTHING FILLS BACK IN TONIGHT. HOWEVER...NOT COMPLETELY SOLD ON
THIS DRYING HAPPENING AS WE WILL STILL BE WITHIN A WAA PATTERN
WITH DECENT MOISTURE TRANSPORT...SO THERE IS POTENTIAL FOR ANY
BREAK TO FILL IN RATHER QUICKLY. ALSO SEE EAST WINDS TRYING TO
BRING SOME HIGHER CIGS IN FROM CENTRAL WI...BUT RAIN MOISTENED AIR
OVER MN SEEMS TO BE PUTTING ANY HALT TO THIS. THOUGH IF THE END IN
PRECIP DOES MATERIALIZE...THEN WE COULD SEE THESE CIGS MAKE A RUN
TO ABOUT MSP/STC BEFORE PRECIP RETURNS AS MID/UPPER LEVEL MOISTURE
RETURNS. FOR P-TYPE...LIKE THE IDEA OF THE NAM AND OTHER HIRES
MODELS WITH PRECIP TURNING OVER TO SNOW UP TOWARD DULUTH/PARK
RAPIDS TONIGHT THAT WILL BUILD SOUTH INTO CENTRAL MN AFTER 9Z AS
A STRONG DEFORMATION BAND OF PRECIP SETS UP. EXPECT THE HEART OF
THIS PRECIP BAND TO SEE MAINLY SNOW DURING THE DAY ON TUESDAY. FOR
NOW...BEST CHANCE OF SNOW /AND ACCUMULATING AT THAT/ IS AT STC
DOWN TO THE WRN TWIN CITIES...BUT MSP CERTAINLY NOT OUT OF THE
WOODS. ONCE THIS DEFORMATION BAND SETS UP BY TUESDAY
MORNING...CONFIDENCE IS HIGH IN IFR CIGS/VIS DOMINATING ALL BUT
MAYBE AXN/EAU FOR MOST OF TUESDAY.
KMSP...CONFIDENCE IS MODERATE WITH MOMENTARY END TO PRECIP THIS
EVENING...BUT LOWER WITH WHEN IN IT WILL RETURN TONIGHT...BUT FEEL
ANY BREAK WILL BE DONE BY 6Z. AFTER THAT...THE QUESTION BECOMES DO
WE SWITCH OVER TO A RASN MIX OR JUST PLAIN SNOW AT SOME POINT
TUESDAY MORNING. DID INTRODUCE A MIX WITH THIS TAF. BASED ON THE
NAM...12Z MAY BE A BIT EARLY...BUT IT IS NOT ENTIRELY OUT OF THE
QUESTION THAT THE PREDOMINATE P-TYPE AT MSP FOR MUCH OF TOMORROW
WILL BE ALL SNOW. NOT EXPECTING MUCH IN THE WAY OF ACCUMS ON PAVED
SFCS...BUT IF WE DO GO MOSTLY SNOW...THAT WILL REALLY TANK THE
VSBYS TOMORROW. IF YOU ARE LOOKING FOR SOME HIGH CONFIDENCE IN
THIS TAF...LOOK NO FURTHER THAN THE WINDS.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS.
THU...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS.
FRI...MVFR CONDS...PRECIP DECREASING. WINDS NW 10-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 410 PM CDT MON APR 28 2014
ENDURED THE HEAVIEST PCPN OF THE STORM LAST 48 HRS...AND NOW ONTO
LIGHTER AMOUNTS THOUGH PRETTY CONSISTENT FOR THE NEXT FEW DAYS.
SMALLER STREAMS/TRIBS WILL BEGIN TO SLOW THEIR RISES NEXT 24
HRS...REMAINING BELOW FS. WILL CONTINUE TO WATCH SAND CREEK/JORDAN
THOUGH EXPECT IT TO QUICKLY BACK OFF NOW THAT MAIN PCPN BAND HAS
MOVED NORTH. MAINSTEM RIVERS WILL CONTINUE SLOW RISE THROUGH THE
WEEK...WITH BANKFUL BECOMING POSSIBLE ALONG MISSISSIPPI N AND S OF
TWIN CITIES. HWVR...THREAT OF REACHING FS STILL MARGINAL AT BEST.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
HYDROLOGY...CCS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
134 PM CDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT MON APR 28 2014
THE NEXT SPOKE OF 700-600MB FRONTOGENESIS/OMEGA WILL LIFT ACROSS
THE AREA THIS MORNING...AND BRING THE NEXT BOUT OF RAIN SHOWERS.
GROUND CONDITIONS ARE QUITE SATURATED...ESPECIALLY EAST OF AN
ALEXANDRIA TO MANKATO LINE...TOWARD THE TWIN CITIES AND TURTLE
LAKE WISCONSIN...WHERE RAINFALL AMOUNTS ON THE ORDER OF 1.5 TO
3 INCHES FELL OVER THE LAST 24 HOURS. UNFORTUNATELY...THIS AREA
APPEARS TO GET NAILED WITH ANOTHER 1-3 INCHES TODAY. VIEW THE
HYDROLOGY DISCUSSION BELOW FOR MORE INFORMATION ON HOW THIS WILL
IMPACT THE RIVERS AND LOW LYING AREAS.
BY LATE AFTERNOON...WE SHOULD START TO SEE SOME DRYING WORKING
INTO SOUTHERN MN...BUT THAT WILL QUICKLY FILL BACK IN WITH
PRECIPITATION THIS EVE AS THE LOW SHIFTS TO CENTRAL IA AND THE
DEFORMATION PRECIP SETS UP OVER THE AREA. COLDER AIR WILL ALSO
WORK INTO CENTRAL MN FROM THE NORTH...WHICH WILL MEAN THE
POTENTIAL FOR SNOW TO ENTER THE MIX DURING THE NIGHTTIME HOURS.
COULD SEE SOME MINOR ACCUMULATIONS ACROSS CENTRAL MN BETWEEN
MIDNIGHT AND DAYBREAK TUESDAY.
HIGHS TODAY WILL NOT GO VERY FAR...NOR WILL LOWS TONIGHT...AS
ABUNDANT LOW CLOUDS AND PRECIP LINGER.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 415 AM CDT MON APR 28 2014
MODELS REMAIN LOCKED INTO THIS VERY UNUSUAL WEATHER PATTERN AS THE
UPPER LOW CONTROLS THE UPPER MIDWEST THRU FRIDAY.
SYNOPTICALLY...THE UPPER LOW AND ASSOCIATED SFC FEATURE WILL WEAKEN
AND FILL ACROSS THE PLAINS...AND INTO THE UPPER MIDWEST AS THE MEAN
UPPER FLOW IS CUTOFF THRU THU. MODELS ARE NEARLY IDENTICAL ON THE
ORIENTATION OF THE UPPER LOW AS IT MOVES SLOWLY EASTWARD TOWARD IOWA
BY TUESDAY MORNING...THEN PIVOTS AND ROTATES ACROSS THE WESTERN
GREAT LAKES THRU THURSDAY NIGHT.
AS PREVIOUS DISCUSSED WITH CUTOFF SYSTEMS...MODELS ARE USUALLY TOO
FAST ON MOVING THEM OUT. IT USUALLY TAKES A KICKER OR SOME STRONGER
WX FEATURE TO MOVE IT ALONG. ONLY THE GFS HOLDS ONTO THE UPPER LOW A
BIT SLOWER THAN THE EC/GEM. ALTHOUGH THE KICKER WILL BE ANOTHER
SHRTWV MOVING SE ACROSS THE PLAINS OF CANADA...IT REMAINS TOO FAST
BASED ON THE ASSOCIATED BIASES OF THE MODELS. THEREFORE...THE
CONTINUED TREND OF CLOUDS...SCATTERED PRECIPITATION AND COOL CONDS
WILL REMAIN AT LEAST THRU THURSDAY. LATEST FORECAST HAS A
DIMINISHING TREND ON POPS WITH ONLY CHC/SLIGHT CHC/S BY THU/FRI. THE
DIMINISHING TREND IS BASED ON THE MAIN MOISTURE FEED CUTOFF FROM THE
GULF AND ONLY RESIDUAL MOISTURE WILL BE PRESENT AFTER MONDAY NIGHT.
ONE TREND THE MODELS HAVE INDICATED IN PREVIOUS RUNS IS THE
THICKNESS VALUES DECREASING TO CRITICAL LEVELS BY LATE
MONDAY/TUESDAY MORNING...AND ESPECIALLY WED. AS THE UPPER LOW BEGINS
TO PIVOT TUE/WED...THE AIR MASS WHICH IS CURRENTLY OVER SE
CANADA...WILL BE DRAWN WESTWARD OVER THE NORTHERN GREAT LAKES...AND
ACROSS THE UPPER MIDWEST/NORTHERN PLAINS. AS THICKNESS VALUES FALL
AND THE THERMAL COLUMN BLW 1KM HOLDS OR EVEN FALLS TO NEAR +1C...THE
RAIN WILL BEGIN TO MIX WITH SNOW. EVEN THE WRF MODELS NMM/ARW HAVE
THE PRECIPITATION TYPE MIXING OR CHANGING OVER TO SNOW TUE
MORNING...AND AGAIN TUESDAY NIGHT AS SFC TEMPS FALL INTO THE MID
30S. IT IS NOT OUT OF THE QUESTION TO SEE SOME LIGHT ACCUMULATIONS
IF ALL THE RIGHT INGREDIENTS OCCUR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1248 PM CDT MON APR 28 2014
THREE MAIN CONCERNS THIS TAF PERIOD ARE THE PRECIP BREAK COMING UP
FROM THE SOUTH...HOW FAR WEST DO VFR CIGS OVER WI MAKE INTO
MN...AND P-TYPE LATE TONIGHT/TUE MORNING. SEEING WARMING OF CLOUD
TOPS COMING UP FROM THE SOUTH...AND GFS/NAM RH TIME CROSS SECTIONS
SHOWS THIS IS ASSOCIATED WITH A MOMENTARY LOSS IN DEEP
MOISTURE...WHICH SUPPORTS THE BRIEF DRYING NOTED IN THE HIGH RES
MODELS. THEREFORE...FOLLOWED THE HRRR AND OTHER HIGH RES MODELS
WITH BRINGING A BREAK IN THE FALLING PRECIP THIS EVENING...BEFORE
EVERYTHING FILLS BACK IN TONIGHT. HOWEVER...NOT COMPLETELY SOLD ON
THIS DRYING HAPPENING AS WE WILL STILL BE WITHIN A WAA PATTERN
WITH DECENT MOISTURE TRANSPORT...SO THERE IS POTENTIAL FOR ANY
BREAK TO FILL IN RATHER QUICKLY. ALSO SEE EAST WINDS TRYING TO
BRING SOME HIGHER CIGS IN FROM CENTRAL WI...BUT RAIN MOISTENED AIR
OVER MN SEEMS TO BE PUTTING ANY HALT TO THIS. THOUGH IF THE END IN
PRECIP DOES MATERIALIZE...THEN WE COULD SEE THESE CIGS MAKE A RUN
TO ABOUT MSP/STC BEFORE PRECIP RETURNS AS MID/UPPER LEVEL MOISTURE
RETURNS. FOR P-TYPE...LIKE THE IDEA OF THE NAM AND OTHER HIRES
MODELS WITH PRECIP TURNING OVER TO SNOW UP TOWARD DULUTH/PARK
RAPIDS TONIGHT THAT WILL BUILD SOUTH INTO CENTRAL MN AFTER 9Z AS
A STRONG DEFORMATION BAND OF PRECIP SETS UP. EXPECT THE HEART OF
THIS PRECIP BAND TO SEE MAINLY SNOW DURING THE DAY ON TUESDAY. FOR
NOW...BEST CHANCE OF SNOW /AND ACCUMULATING AT THAT/ IS AT STC
DOWN TO THE WRN TWIN CITIES...BUT MSP CERTAINLY NOT OUT OF THE
WOODS. ONCE THIS DEFORMATION BAND SETS UP BY TUESDAY
MORNING...CONFIDENCE IS HIGH IN IFR CIGS/VIS DOMINATING ALL BUT
MAYBE AXN/EAU FOR MOST OF TUESDAY.
KMSP...CONFIDENCE IS MODERATE WITH MOMENTARY END TO PRECIP THIS
EVENING...BUT LOWER WITH WHEN IN IT WILL RETURN TONIGHT...BUT FEEL
ANY BREAK WILL BE DONE BY 6Z. AFTER THAT...THE QUESTION BECOMES DO
WE SWITCH OVER TO A RASN MIX OR JUST PLAIN SNOW AT SOME POINT
TUESDAY MORNING. DID INTRODUCE A MIX WITH THIS TAF. BASED ON THE
NAM...12Z MAY BE A BIT EARLY...BUT IT IS NOT ENTIRELY OUT OF THE
QUESTION THAT THE PREDOMINATE P-TYPE AT MSP FOR MUCH OF TOMORROW
WILL BE ALL SNOW. NOT EXPECTING MUCH IN THE WAY OF ACCUMS ON PAVED
SFCS...BUT IF WE DO GO MOSTLY SNOW...THAT WILL REALLY TANK THE
VSBYS TOMORROW. IF YOU ARE LOOKING FOR SOME HIGH CONFIDENCE IN
THIS TAF...LOOK NO FURTHER THAN THE WINDS.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS.
THU...MVFR/IFR CONDS WITH PERIODS OF -SHRA. WINDS NW 10-15 KTS.
FRI...MVFR CONDS...PRECIP DECREASING. WINDS NW 10-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 415 AM CDT MON APR 28 2014
24 HOUR PRECIP AMOUNTS /ENDING AT 09Z MONDAY/ INDICATE A SOLID SWATH
OF 1 TO 2.5 INCHES FELL ACROSS CENTRAL AND SOUTH CENTRAL MN AND
INTO WEST CENTRAL WI...GENERALLY EAST OF AN ALEXANDRIA TO MANKATO
LINE...ACROSS THE INTERSTATE 35 CORRIDOR AND INTO WEST CENTRAL
WISCONSIN /AS FAR EAST AS TURTLE LAKE AND NEW RICHMOND/. THIS AREA
WILL BE UNDER THE GUN AGAIN TODAY FOR ANOTHER DOUSING OF RAIN ON
THE ORDER OF 1-2 INCHES. THE IMMEDIATE CONCERN WILL BE FOR MINOR
AREAL FLOODING IN LOW LYING AREAS AND POOR DRAINAGE LOCALES. WHILE
THE BRIEF RESPITE FROM RAIN OVERNIGHT SHOULD HELP A BIT...THERE
WILL LIKELY BE SPOTS THAT HAVE PONDING ISSUES FURTHER EXACERBATED
BY TODAY/S BOUT OF RAIN. THE SECOND CONCERN HYDROLOGICALLY
SPEAKING IS WITH REGARD TO THE POTENTIAL FOR RIVER FLOODING. RISES
ON LOCAL STREAMS HAVE YIELDED SMALL RISES ON THE ST
CROIX...MISSISSIPPI... MINNESOTA...CHIPPEWA...AND CROW RIVERS AMONG
OTHERS. WILL LIKELY SEE SEVERAL SITES ALONG THESE RIVERS CREEP
TOWARD THEIR ACTION STAGES WITH THE ADDITIONAL 1 TO 2 INCHES
EXPECTED TODAY. THE SITE OF GREATEST CONCERN AT THE CURRENT TIME
IS THE MISSISSIPPI AT HASTINGS...WHICH COULD RISE ABOVE FLOOD
STAGE IF THE PRECIPITATION FORECAST WORKS OUT AS ANTICIPATED.
THANKFULLY...THE RESPONSE TIME IS NOT QUICK...SO THERE IS TIME
FOR FORECAST REFINEMENT GIVEN CURRENT INDICATIONS ARE THAT IT
WOULD NOT RISE ABOVE FS UNTIL THE 3RD OF MAY. FOR THE WI
SITES...THE CHIPPEWA AT DURAND BEARS WATCHING...BUT HAS MORE
WIGGLE ROOM GIVEN PRECIP 24 PRECIP AMOUNTS FEEDING INTO THE RIVER
WERE SLIGHTLY LOWER.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...LS
LONG TERM...JLT
AVIATION...MPG
HYDROLOGY...LS
AREA FORECAST DISCUSSION
NWS JACKSON MS
1141 AM CDT MON APR 28 2014
.UPDATE......SEVERE WEATHER OUTBREAK EXPECTED THIS AFTERNOON AND EVENING...
...SIGNIFICANT FLOODING POSSIBLE MONDAY INTO EARLY TUESDAY...
.UPDATE...NOT MANY UPDATES MADE TO GOING FORECAST AS SEVERE
WEATHER OUTBREAK REMAINS ON TRACK FOR LATE THIS MORNING AND
ESPECIALLY INTO THIS AFTERNOON AND EVENING WHERE STRONG AND POSSIBLY
LONG TRACK TORNADOES COULD OCCUR. CAUTION IS HIGHLY ADVISED FOR
THIS POTENTIALLY LIFE THREATENING AND DANGEROUS SITUATION.
.DISCUSSION...INITIAL LEAD S/WV RESPONSIBLE FOR THIS MORNINGS ACTIVELY
IS LIFTING NE AWAY FROM THE REGION RESULTING IN A WEAKENING TREND OF
THAT ACTIVITY. HOWEVER, A CYCLONICALLY CURVED H5-H3 JET STREAK IS
OBSERVED ON WV CHANNELS...REGIONAL VAD WIND PROFILES AND IN NWP
SURGING INTO THE NW DELTA AND THE ARKLAMISS AT THIS HOUR. THIS
SIGNATURE COUPLED WITH NEAR 2000 J/KG SBCAPE IS ALREADY INITIALIZING
ACROSS THE DELTA REGION WITH THE THIS NEXT AND MORE POTENT ROUND OF
SEVERE WEATHER EXPECTED FOR THE REGION. 0-1 KM ESRH REMAINS NEAR
200M2/S2 PER MESOANALYSIS AS OF 16Z BUT NWP SUITE SUGGESTS STEADILY
INCREASING LOW LVL SHEAR VALUES TOWARDS 300M2/S2 AND POSSIBLY HIGHER
THROUGH THE EARLY AFTN AND EVENING WHERE WORRISOME 0-1 KM EHI AND
STRONG TORNADO PARAMETERS VALUES INDICATE HEALTHY ENVIRONMENT CAPABLE
OF SUPPORTING SOME STRONG AND POSSIBLY LONG TRACK TORNADOES. SPC SSEO
UPDRAFT HELICITY SIGNALS SUGGEST THAT GREATEST RISK FOR THESE
TORNADOES COULD BE ACROSS NORTH CENTRAL AND NORTHEAST MISSISSIPPI
EXTENDING ALONG THE NATCHEZ TRACE CORRIDOR TOWARDS THE JACKSON
METROPLEX MID TO LATE AFTERNOON INTO THE EVENING. A COUPLE OF ROUGE
STORMS COULD ALSO DEVELOP SOUTH OF I-20 AND WITH LESS COMPETITION FOR
RESOURCES AND POTENTIALLY NON-BLOCKED INFLOW COULD BE TROUBLESOME.
THE TRENDS OF LOCAL WRF AND THE HRRR ECHO SPC SSEO HELICITY SIGNALS
THAT WHAT SEMI-DISCRETE STORMS DEVELOP WILL BE CAPABLE OF STRONG
ROTATING UPDRAFTS. NAM BUFR SOUNDINGS FOR JACKSON FOR MID AFTN
SUGGEST 0-3 SRH VALUES NEAR 500 M2/S2 WITH THIS ENVIRONMENT LIKELY IN
PLACE ALONG THE TRACE CORRIDOR. GRAPHICS HAVE BEEN UPDATED TO
REFLECT THIS HIGHER RISK AREA.
UPDATES ARE OUT AND AN UPDATED AVIATION DISCUSSION CAN BE FOUND
DIRECTLY BELOW. /ALLEN/
&&
.AVIATION...MVFR CIGS WERE STILL BEING REPORTED AT 15Z IN THE SOUTH
BUT CIGS SHOULD RISE ABOVE 3KFT BY 17Z AREAWIDE. BREEZY SOUTH WINDS
OF 15-20KTS WITH GUSTS 30KTS AWAY FROM STORMS TODAY. CONDITIONS
COULD DETERIORATE THIS AFTN INTO THE EVENING AS WIDESPREAD
TSTMS...SOME SEVERE WL BE PSBL. AWAY FROM STORMS...MVFR CIGS WL
REDEVELOP TONIGHT AREAWIDE. STRONGER SW WINDS AND ANOTHER ROUND OF
POTENTIALLY SEVERE TSTMS ARE EXPECTED TUESDAY...ESPECIALLY OVER THE
SE HALF OF THE AREA. /22/
&&
.PREV DISCUSSION... /ISSUED 350 AM CDT MON APR 28 2014/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT
SEVERAL ROUNDS OF SIGNIFICANT SEVERE WEATHER HAZARDS ARE EXPECTED TO
IMPACT THE REGION TODAY THROUGH TUESDAY ALONG WITH SOME POSSIBLE
SIGNIFICANT FLOODING FROM HEAVY RAINFALL. TODAY STILL LOOKS TO BE
PARTICULARLY VOLATILE...ESPECIALLY WITH THE STRONG SHEAR IN PLACE.
THE LATEST SATELLITE IMAGERY SHOWED A STRONG CLOSED STORM
CIRCULATION OVER THE CENTRAL PLAINS AROUND NEBRASKA WITH SEVERE
CONVECTION PUSHING ACROSS THE ARKLATEX. A SERIES OF VORT LOBES
WERE ROTATING AROUND THE CLOSED STORM SYSTEM WHICH WAS BRINGING
ASCENT FOR CONVECTIVE FORMATION. A STRONG JET STREAM WAS PIVOTING
AROUND THE SOUTHERN AXIS OF THE CLOSED SYSTEM. THERE WAS AN
ASSOCIATED 985 MB SURFACE LOW WITH AS ASSOCIATED COLD FRONT AND DRY
LINE EXTENDING DOWN INTO TEXAS. WE WERE IN THE WARM SECTOR WITH
DEWPOINTS IN THE MID 60S TO AROUND 70. THE ATMOSPHERE HAD GOOD JET
DYNAMICS ...STRONG VERTICAL SHEAR(EFFECTIVE BULK SHEAR 40-60 KNOTS
AND INSTABILITY IN PLACE FOR MULTIPLE ROUNDS OF A SEVERE WEATHER
OUTBREAK FOR FOR TODAY THROUGH TUESDAY.
FOR TODAY A STRONG SHORTWAVE WILL ROTATE AROUND THE CLOSED SYSTEM
WHILE THE STORM SYSTEM WILL CONTINUE TO DEEPEN. HEIGHT FALLS...
STRONG LAPSE RATES...STRONG DYNAMIC SHEAR AND INSTABILITY WILL
PUSH INTO THE REGION. THIS COULD HELP SEVERE CONVECTION TO DEVELOP
ACROSS THE WEST EARLY AND SPREAD ACROSS THE REGION DURING THE DAY.
THE BROKEN LINE OF DISCRETE SUPERCELL STORMS TO THE WEST WILL PUSH
ACROSS THE REGION TODAY. THE MODEL SOUNDINGS CONTINUE TO SHOW
IMPRESSIVE SIGNATURES FOR ALL MODES OF SEVERE WEATHER FOR TODAY
THROUGH TUESDAY INCLUDING THE RISK OF SOME STRONG TORNADOES. THE
FIRST ROUND WILL AFFECT THE WESTERN AREAS THIS MORNING AND MARCH
ACROSS THE REGION DURING THE DAY. THE SURFACE BOUNDARY/DRYLINE WILL
BE SLOWLY APPROACHING FROM THE WEST. LATEST SPC WRF SHOWS SOME STRONG
MAXIMUM UPDRAFT HELICITY VALUES WITH THESE STORMS. AS WE GO INTO
TONIGHT EXPECT SOME MORE DEVELOPMENT FROM THE WEST. ALOT WILL DEPEND
HOW THE CONVECTIVE FEATURES WILL DEVELOP DURING THE PERIOD FOR BRIEF
PERIODS OF LULLS BETWEEN ROUNDS OF SEVERE WEATHER. SPC HAS PUT MOST
OF THE REGION UNDER A MODERATE RISK FOR DAY ONE. ALSO THE LOCAL WRF
SHOWS IMPRESSIVE UPDRAFT HELICITY IN THE NORTHEAST FOR LATE THIS
AFTERNOON WITH THESE STORMS FROM DISCRETE SUPERCELLS.
HEAVY RAIN WILL ALSO BE A CONCERN FOR TODAY THROUGH EARLY TUESDAY
WITH STRONG UPPER DIVERGENCE. MODELS SOUNDINGS AND CROSS SECTIONS SHOWS
STRONG ASCENT FOR THE INFLOW OF GULF MOISTURE WITH PWATS AROUND 1.8
INCHES. THE DAY ONE GRAPHIC FOR EXCESSIVE RAIN SHOWS A MODERATE RISK
ACROSS MOST OF THE AREA. SOME OF THE WRF MODELS SHOWS SOME POSSIBLE
TRAINING ACROSS SOME OF OUR RIVER BASINS. CORFIDI VECTORS SHOWS SOME
RIDGING MOVING ACROSS THE REGION FOR SOME TRAINING OF CELLS FOR HEAVY
RAINFALL AND SOME POSSIBLE BACKBUILDING. WPC SHOWS 2 TO 4 INCH
RAINFALL AMOUNTS ACROSS THE REGION. SO WITH THAT IN MIND HAVE
EXPANDED THE TIME OF THE CURRENT WATCH AS WELL AS ADDED THE SOUTHEAST
PORTION OF THE REGION AT 22Z UNTIL 12Z TUESDAY.
FOR TUESDAY AND TUESDAY NIGHT...ANOTHER STRONG SHORTWAVE WILL ROTATE
AROUND THE CLOSED SYSTEM OVER NORTHERN MISSOURI. MODELS SHOWS THAT THE
LOW LEVEL INFLOW WILL WEAKEN SOME IN THE LOW LEVELS OF 850 MBS AND
BELOW. THIS WILL WEAKEN THE BULK SHEAR SOME IN THE 1 AND 2 KM LAYER.
HOWEVER THE DEEP LAYER SHEAR 0-6 KM WILL MAKE UP FOR IT WITH READINGS
FROM 60 TO NEAR 100 KNOTS. THIS COMBINED WITH STRONG INSTABILITY WILL
KEEP ALL MODES OF SEVERE WEATHER ON TRACK. THE SURFACE BOUNDARY WILL
MOVE THROUGH THE REGION TUESDAY AFTERNOON AND EVENING. EXPECT THE
BULK OF THE SEVERE WEATHER TO AFFECT MAINLY THE EAST HALF OF THE
REGION AND EXIT OUT OF THE ARKLAMISS BY EARLY TUESDAY EVENING.
AS FAR AS TEMPS ARE CONCERN WENT CLOSE TO GMOS TEMPS FOR DAILY HIGHS AND
CLOSE TO CURRENT FORECAST FOR NIGHTLY LOWS. MOS GUIDANCE LOOKED A LITTLE
COOL FOR THE NIGHTLY LOWS./17/
LONGTERM...WEDNESDAY THROUGH SUNDAY...DESPITE CONTINUED MID/UPPER
LEVEL SW FLOW STILL STREAMING MOISTURE OVER THE REGION WED/THU...LOW
LEVEL NORTHERLY FLOW BEHIND SURFACE BOUNDARY...BY NOW OVER AL...WILL
HAVE SCOURED OUT MAJORITY OF APPRECIABLE MOISTURE. WHILE BOTH THE
GFS AND ECMWF SHOW THIS SCENARIO...GFS MOS WANTS TO PAINT SLIGHT
POPS FOR MUCH OF THE PERIOD WITH NO QPF AT ALL. DO AGREE THAT THERE
WILL BE SOME SLIGHT CHANCE FOR PASSING MID LEVEL WAVE ON
FRIDAY...BUT NOT ALL DURING THE WEEK LEADING UP TO THEN. HAVE CUT
POPS FOR WED/THU AND AGAIN SAT/SUN AS PATTERN JUST DOES NOT LOOK
CONDUCIVE FOR APPRECIABLE...IF ANY...PRECIPITATION. ECMWF SHOWING
SOME CAPES AROUND 500 J/KG AVAILABLE FOR FRIDAY AFTERNOON...WILL ADD
SOME POSSIBILITY FOR THUNDER TO THE EXPECTED SHOWERS.
TEMPS DURING THIS TIMEFRAME WILL BE UNSEASONABLY COOL AND SOME 10 TO
15 DEGREES BELOW NORMAL. DESPITE THE COOL NIGHTTIME LOWS IN THE
40S...TEMPS STILL WILL BE JUST A LITTLE BIT TOO WARM FOR FROST
CONCERNS./26/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 85 68 83 55 / 76 90 59 29
MERIDIAN 85 66 84 55 / 56 100 73 51
VICKSBURG 85 66 82 54 / 84 82 44 22
HATTIESBURG 86 69 85 60 / 40 100 55 31
NATCHEZ 84 69 83 54 / 72 81 36 15
GREENVILLE 83 63 79 52 / 87 79 49 23
GREENWOOD 82 65 81 53 / 86 99 61 28
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR MSZ018-019-025>052.
FLASH FLOOD WATCH FROM 5 PM CDT THIS AFTERNOON THROUGH TUESDAY
MORNING FOR MSZ055>058-063>066-072>074.
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ007>009-015-016.
AR...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR ARZ074-075.
&&
$$
ALLEN/22/17/26
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1136 AM CDT Mon Apr 28 2014
.UPDATE:
Issued at 1135 AM CDT Mon Apr 28 2014
Large cumulus field has recently developed across central Missouri
in convergence zone just ahead of surface cold front/dryline.
Environment is becoming increasing unstable with latest 16Z SPC
MLCAPES showing 500-1000 J/kg over central and eastern Missouri
with little CINH right ahead of the front. Current thinking is
that thunderstorms will develop in the next hour or two right
ahead of the the front and move east and northeast across eastern
Missouri into Illinois during the afternoon hours. Severe threat
including hail and damaging winds continues given the increasing
instability and impressive deep layer shear. Also, 0-1km SRH
values are currently between 100 and 250 across eastern Missouri
and Illinois support an isolated tornado risk.
Britt
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 152 AM CDT Mon Apr 28 2014
Latest HRRR weakens most of the convection currently across our
forecast area, or shifts it southeast of the region by 12z Monday.
There may be a brief lull in the convection early this morning, then
new convection should break out late this morning and early this
afternoon from Edina to Quincy and south through the St Louis metro
area to the FAM area, then shift eastward through our IL counties
later this afternoon. This will occur as a shortwave ejects out of
the southern Plains into southeast MO and a cold front/dry line
surges eastward into eastern MO by 00z Tue. Should have CAPEs up to
2000-2500 J/Kg ahead of the cold front around 18z Monday with
surface LI values down to around -10. Strongest low-mid level wind
shear should be across southeast MO and southwest IL with strong
500 mb wind max moving through AR into portions of southeast MO,
southern IL, and western portions of TN and KY. The severe weather
threat should be over the eastern portion of our area, in portions
of west central and southwest IL with the primary threat being large
hail and damaging winds. This will occur from the late morning,
through the afternoon and into the early evening hours.
GKS
.LONG TERM: (Tonight through Sunday)
Issued at 341 AM CDT Mon Apr 28 2014
The showers and thunderstorms should be confined to areas east of
the Mississippi River this evening and should be weakening by late
evening as the higher surface dewpoints and instability shifts east
of our forecast area. Little if any precipitation should be left
late tonight. Temperatures will be cooler tonight due to low level
cold air advection in our area south of the upper level and
associated surface low. More showers and a few thunderstorms on
Tuesday as the moisture wraps around the slow moving upper/surface
low north of our area. The best chance for rain will be across the
northwest half of our forecast area. The models keep the showers
going Tuesday night as shortwaves rotate around the mid-upper level
low. The gradual cooling trend will continue with well below normal
temperatures for Wednesday and Wednesday night. The GFS and ECMWF
models drop the zero degree C 850 mb isotherm southeastward into our
forecast area Tuesday night or Wednesday, the cooler NAM even
earlier. Although there will likely be rain across our area again
on Wednesday it should be on the light side. The rain should be
mainly diurnal on Thursday and Friday and favor the northern portion
of our forecast area as the upper level low weakens and moves into
the Great Lakes region. Will see warmer high temperatures for the
weekend as the upper level heights begin to rise and southerly
surface/low level flow returns Saturday night. Low-mid level warm
air advection ahead of a weak shortwave and associated surface low
may bring showers to the extreme northern portion of our forecast
area late Saturday night and Sunday.
GKS
&&
.AVIATION: (For the 12z TAFs through 12z Tuesday Morning)
Issued at 633 AM CDT Mon Apr 28 2014
VFR conditions outside of TSRA will prevail at the TAF sites thru
the valid period. Another round of TSRA is expected to develop
mainly east of the MS river around midday, leaving UIN and the STL
Metro sites on the backedge of what does form. Due to these TAF
sites being on the backedge, have elected to keep VCTS mention
versus TEMPO until we get closer to initiation time. What does
develop should shove off to the northeast by late afternoon. Gusty
southerly winds are expected, diminishing tonight.
Specifics for KSTL: VFR outside of TSRA thru the valid period.
Another round of TSRA is expected to develop over the STL Metro
area around midday with what does form shoving off to the
northeast by mid-afternoon. Due to the terminal anticipated to
being on the backedge, have elected to keep VCTS mention versus
TEMPO until we get closer to initiation time. Gusty southerly
winds are expected, diminishing tonight.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
641 PM EDT MON APR 28 2014
.SYNOPSIS...
UNSETTLED WEATHER WILL PERSIST OVER THE NEXT COUPLE OF DAYS. SHOWERS
AND THUNDERSTORMS ARE EXPECTED INCREASE IN COVERAGE THROUGH
WEDNESDAY AS A TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST.
ANOTHER QUICK ROUND OF RAIN IS POSSIBLE LATE FRIDAY AND SATURDAY
BEFORE CONDITIONS DRY OUT INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 PM MONDAY...A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS
DEVELOPED ALONG A STATIONARY FRONT ACROSS SOUTHERN NORTH CAROLINA A
FEW HOURS AGO. SUBJECTIVE SURFACE ANALYSIS SHOWED SIGNIFICANT
BACKING OF THE LOW-LEVEL WIND ACROSS THE COASTAL PLAIN OF NC WHILE
MODIFIED 18Z MODEL SOUNDINGS INDICATED CAPE AS HIGH AS 2700 J/KG
EARLIER. MULTICELL STORMS DEVELOPED BUT DID NOT DISPLAY SIGNIFICANT
DEVIANT MOTION AS THEY MIGHT HAVE HAD SUPERCELLS DEVELOPED. STILL...
HIGH REFLECTIVITY CORES REACHED INTO COLD ENOUGH LAYERS OF THE
ATMOSPHERE TO LEAD US TO BELIEVE LARGE HAIL WAS A SIGNIFICANT
THREAT. IF YOU OBSERVED HAIL OR WIND DAMAGE ACROSS ROBESON OR BLADEN
COUNTIES THIS EVENING PLEASE LET US KNOW!
THE FRONT SHOULD REMAIN NEARLY STATIONARY ACROSS SOUTHERN NORTH
CAROLINA THIS EVENING...MAINLY JUST NORTH OF LUMBERTON AND
ELIZABETHTOWN ARCING NORTHEASTWARD TOWARD NEW BERN ALONG THE COAST.
THIS WILL LEAVE OUR FORECAST AREA IN A WARM AND HUMID TROPICAL
AIRMASS WITH DEWPOINTS AND LOW TEMPERATURES FORECAST TO BE IN THE
UPPER 60S. THE 500 MB RIDGE AXIS THAT HAS HELPED TO SUPPRESS
PRECIPITATION OVER THE PAST FEW HOURS WILL FINALLY PUSH OFFSHORE
LATE TONIGHT...AND THERE IS THE POTENTIAL FOR A REDEVELOPMENT OF AT
LEAST ISOLATED SHOWERS/T-STORMS JUST BEFORE DAYBREAK AS WIND VECTORS
BECOME DIFLUENT ALOFT AND THE 850 MB WIND BACKS AND STRENGTHENS.
PREVIOUS DISCUSSION FROM 230 PM FOLLOWS...
INCREASINGLY WARM AND MORE UNSTABLE AIR MASS WITH TEMPS INTO THE 80S
MOST PLACES. MODELS STILL SHOW MID TO UPPER RIDGE LINED UP THE
SOUTHEAST COAST WHICH SHOULD HELP TO INHIBIT SOME OF THE STRONGEST
CONVECTION RUNNING SOUTH...BUT AS TEMPS WARMED INTO THE 80S AND
DEWPOINTS INTO THE MID 60S CLOSER TO 70 OVER SOUTH CAROLINA. HRRR
AND RUC SHOWING BEST CAPE LINED UP INLAND FROM SOUTH TO NORTH TOWARD
DARLINGTON AND MARLBORO...BUT MAIN FOCUS OF STRONGER CONVECTION WILL
BE ALONG THE LINGERING FRONTAL BOUNDARY JUST TO THE NORTH OF LOCAL
FORECAST AREA. EXPECT SCT CONVECTION OVER THE AREA WITH MAIN FOCUS
ALONG SEA BREEZE CONVERGENT BOUNDARY AND RUNNING ALONG LINGERING
FRONTAL BOUNDARY. JUST NORTH OF BOUNDARY STILL SEEING TEMPS NOT EVEN
REACHING 70 WITH COOLER AIR WEDGED IN.
BEST HELICITY WILL RUN ALONG WARM FRONT WITH VALUES ABOVE 200 JUST
TO NORTH. OVERALL SHOULD BE RATHER FINE BOUNDARY OF STRONGEST STORMS
AS FORCING REMAINS WEAKER FARTHER SOUTH DUE TO INCREASED SUBSIDENCE
WITH MID TO UPPER RIDGE OVER THE SOUTHEAST COAST. OVERALL THREAT OF
HAIL AND STRONG WINDS WITH ANY STORMS THAT MAY REACH INTO OUR
NORTHERN TIER COUNTIES. THE STEERING FLOW WILL PUSH ANY SHWRS/TSTMS
THAT DEVELOP TOWARD THE COAST BUT THE MORE STABILIZED AIR BEHIND SEA
BREEZE SHOULD KEEP THE IMMEDIATE COAST FREE OF STORMS. KEPT POPS
VERY CLOSE TO PREVIOUS FORECAST WITH ONLY MINOR ADJUSTMENTS AND WILL
UPDATE AS NEEDED ONCE CONVECTION FLARES. SHOULD SEE A FAIR AMOUNT OF
CLOUDS AS CONVECTIVE DEBRIS CLOUDS WILL BE STEERED EAST MIXED WITH
CU FIELD ACROSS THE AREA.
THE STALLED BOUNDARY WILL BEGIN TO LIFT NORTH THROUGH TONIGHT AND
EXPECT LOCALIZED CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS
OFF AFTER SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING
BEST CHC TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET
NIGHT WITH LOWS WELL ABOVE CLIMO...RUNNING IN THE MID 60S IN A WARM
AND HUMID AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...ATTENTION THROUGHOUT THE ENTIRE FORECAST
PERIOD WILL FOCUS ON UNSETTLED WEATHER...INCLUDING THE THREAT FOR
SEVERE WEATHER JUST AHEAD OF AN APPROACHING COLD FRONT. LATEST
GUIDANCE CONTINUES TO ILLUSTRATE A LONGWAVE TROUGH ACROSS THE CONUS
WITH A PERSISTENT UPPER LEVEL LOW WHICH WILL SLOWLY PROGRESS ACROSS
THE MIDWEST OVER THE NEXT COUPLE OF DAYS. WARM TEMPERATURES AND
SOUTHWEST FLOW WILL ALLOW FOR A MOISTURE-RICH ATMOSPHERE...AS
DEWPOINTS ARE WELL IN THE 60S...TO REMAIN IN PLACE WITH HIGHS ON
TUESDAY IN THE LOWER 80S ACROSS THE ENTIRE FORECAST AREA. SHOWERS
AND THUNDERSTORMS ARE EXPECTED THROUGHOUT THE DAY ON TUESDAY WHICH
IS IN GOOD AGREEMENT AS OUR AREA IS INCLUDED IN SPC`S SLIGHT RISK.
INTO WEDNESDAY...CONDITIONS WILL CONTINUE TO PROGRESS IN
INCREASE...AS IT LOOKS THE BETTER INSTABILITY AND LIFT WILL MOVE
INTO THE CENTRAL SC/NC/VA AREA...WITH A HEIGHTENED POSSIBILITY OF
SEVERE ESPECIALLY IN OUR WESTERN ZONES. DIFFICULTY WILL BE TIMING AS
MODELS HAVE EVER SO SLIGHTLY SLOWED DOWN THE PROGRESSION OF THE
SYSTEM IN PAST RUNS. HOWEVER...OVERALL ANTICIPATE MAIN THREAT TO
OCCUR WEDNESDAY THROUGHOUT THE DAY WITH AMPLE DIURNAL HEATING WITH
HIGHS ON WEDNESDAY AGAIN IN THE 80S...INTO EARLY THURSDAY MORNING.
WILL ALSO TAKE INTO ACCOUNT THE INTERACTION OF THE SEA BREEZE AS
WELL ON BOTH DAYS AND ANY OTHER WANDERING BOUNDARIES ABOUT THE AREA.
THE PRIMARY THREATS WILL BE HAIL AND DAMAGING WINDS...ALONG WITH THE
POSSIBILITY OF TORNADOES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...THURSDAY MAY BE RATHER ACTIVE. THE UPPER RIDGE
AXIS WILL BE OFFSHORE ALLOWING FOR DEEP SWRLY FLOW. SURFACE BOUNDARY
AND UPPER LEVEL VORT MAXES MAY SPONSOR DEEP ENOUGH LIFT FOR FAIRLY
WIDESPREAD CONVECTION. WIND FIELDS MAY BE STRONG ENOUGH FOR STORM
ORGANIZATION WITH DAMAGING WIND AND/OR HAIL. MORE QUESTIONABLE
WHETHER OR NOT INSTABILITY MANAGES TO DEVELOP HOWEVER. BOUNDARY
PUSHES OFFSHORE THURSDAY NIGHT WHICH MAY ALLOW FOR A COOLER AND
DRIER FRIDAY. TRAILING UPPER ENERGY ON SATURDAY BUT TOUGH CALL AS TO
WHETHER OR NOT ENOUGH MOISTURE AROUND FOR MEANINGFUL RAIN CHANCES.
DRY WNW FLOW FOR SUNDAY AND MONDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z..STILL LOOKING FOR CONVECTION TO FIRE ALONG A DIFFUSE WARM
FRONT THIS AFTERNOON. MOST OF THE ACTIVITY WILL BE OVER THE NORTHERN
THIRD OF THE CWA...BUT COULD NOT RULE OUT WEAK CONVECTION TO THE
SOUTH ALONG THE SEA BREEZE BOUNDARY. BRIEF IFR PERIODS ARE
POSSIBLE...MAINLY AT LBT AND ILM. MOST OF THE ACTIVITY WILL END THIS
EVENING AS THE WARM FRONT WAVES NORTH. WITH THE SOUTHWESTERLY FLOW
TONIGHT...IFR STRATUS IS A REASONABLE BET. TUESDAY...BECOMING VFR
WITH ANOTHER ROUND OF CONVECTION POSSIBLE BY THE END OF THE FORECAST
PERIOD.
EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH THURSDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 645 PM MONDAY...BASED ON OBSERVATIONS AND THE 18Z MODELS I
HAVE INCREASED WIND SPEEDS THROUGH THE NIGHT BY A FEW KNOTS...WITH
10-15 KNOTS EXPECTED FOR MOST AREAS THROUGH THE NIGHT. THAT SHOULD
SUPPORT 2 FOOT SEAS BUILDING THROUGH 3 FEET OVERNIGHT. A CLUSTER OF
STRONG TO SEVERE THUNDERSTORMS ACROSS SOUTHEASTERN NC SHOULD LARGELY
MISS THE COASTAL WATERS...BUT THERE IS A POTENTIAL FOR ISOLATED
SHOWERS OR T-STORMS THIS EVENING...THEN PERHAPS REDEVELOPING VERY
LATE TONIGHT. PREVIOUS DISCUSSION FROM 230 PM FOLLOWS...
QUIET MARINE CONDITIONS OVERALL THROUGH THIS AFTERNOON. HIGH
PRESSURE REMAINS OVER THE AREA WITH LINGERING BOUNDARY LIFTING NORTH
OF THE THE WATERS. GRADIENT REMAINS LIGHT WITH SOUTH TO SOUTHEAST
FLOW REMAINING UNDER 10 KT THROUGH THE MORNING HOURS WITH SEAS 2 FT
OR LESS. MAY SEE A FEW LINGERING SHOWERS MAKE IT OVER THE WATERS
JUST ALONG NORTHERN PORTION OF LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...EXPECT SOUTH- SOUTHWEST FLOW TO PERSIST
THROUGH THE FORECAST PERIOD WITH INCREASING WINDS WEDNESDAY INTO
WEDNESDAY EVENING WHERE WINDS WILL INCREASE TO AROUND 20 TO 25
KTS...WHILE THE REMAINDER OF THE PERIOD ANTICIPATE 15 TO 20 KTS
WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE. AS
FOR SEAS...2 TO 4 FT WITH 5 FT POSSIBLE. COULD SEE 6 TO 7 FT
POSSIBLE IN THE OUTER WATERS WEDNESDAY INTO THURSDAY MORNING.
ANTICIPATE CONDITIONS WILL WARRANT A SMALL CRAFT ADVISORY
WEDNESDAY EVENING.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 PM MONDAY...PREFRONTAL FLOW REGIME ON THURSDAY PROBABLY
STRONG ENOUGH TO WARRANT A SMALL CRAFT ADVISORY. A WINDSHIFT TO A
MORE OFFSHORE DIRECTION THURSDAY NIGHT INTO FRIDAY PAIRED WITH A
DOWNWARD TREND IN THE WIND SPEED WILL ALLOW ADVISORY TO BE DROPPED.
OFFSHORE WINDS AND FAIRLY SEASONABLE SEAS CONTINUES INTO SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FOR INLAND NEW HANOVER COUNTY FROM 9 PM
UNTIL MIDNIGHT.
MARINE...NONE.
&&
$$
SYNOPSIS...SGL
NEAR TERM...RGZ/TRA
SHORT TERM...SGL
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
348 PM EDT MON APR 28 2014
.SYNOPSIS...
UNSETTLED WEATHER WILL PERSIST OVER THE NEXT COUPLE OF DAYS AS
SHOWERS AND THUNDERSTORMS ARE EXPECTED INCREASE IN COVERAGE TODAY
THROUGH WEDNESDAY AS A TROUGH OF LOW PRESSURE APPROACHES FROM THE
WEST. ANOTHER QUICK ROUND OF RAIN IS POSSIBLE LATE FRIDAY AND
SATURDAY BEFORE CONDITIONS DRY OUT INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...INCREASINGLY WARM AND MORE UNSTABLE AIR MASS
WITH TEMPS INTO THE 80S MOST PLACES. MODELS STILL SHOW MID TO UPPER
RIDGE LINED UP THE SOUTHEAST COAST WHICH SHOULD HELP TO INHIBIT SOME
OF THE STRONGEST CONVECTION RUNNING SOUTH...BUT AS TEMPS WARMED INTO
THE 80S AND DEWPOINTS INTO THE MID 60S CLOSER TO 70 OVER SOUTH
CAROLINA. HRRR AND RUC SHOWING BEST CAPE LINED UP INLAND FROM SOUTH
TO NORTH TOWARD DARLINGTON AND MARLBORO...BUT MAIN FOCUS OF STRONGER
CONVECTION WILL BE ALONG THE LINGERING FRONTAL BOUNDARY JUST TO THE
NORTH OF LOCAL FORECAST AREA. EXPECT SCT CONVECTION OVER THE AREA
WITH MAIN FOCUS ALONG SEA BREEZE CONVERGENT BOUNDARY AND RUNNING
ALONG LINGERING FRONTAL BOUNDARY. JUST NORTH OF BOUNDARY STILL
SEEING TEMPS NOT EVEN REACHING 70 WITH COOLER AIR WEDGED IN.
BEST HELICITY WILL RUN ALONG WARM FRONT WITH VALUES ABOVE 200 JUST
TO NORTH. OVERALL SHOULD BE RATHER FINE BOUNDARY OF STRONGEST STORMS
AS FORCING REMAINS WEAKER FARTHER SOUTH DUE TO INCREASED SUBSIDENCE
WITH MID TO UPPER RIDGE OVER THE SOUTHEAST COAST. OVERALL THREAT OF
HAIL AND STRONG WINDS WITH ANY STORMS THAT MAY REACH INTO OUR
NORTHERN TIER COUNTIES. THE STEERING FLOW WILL PUSH ANY SHWRS/TSTMS
THAT DEVELOP TOWARD THE COAST BUT THE MORE STABILIZED AIR BEHIND SEA
BREEZE SHOULD KEEP THE IMMEDIATE COAST FREE OF STORMS. KEPT POPS
VERY CLOSE TO PREVIOUS FORECAST WITH ONLY MINOR ADJUSTMENTS AND WILL
UPDATE AS NEEDED ONCE CONVECTION FLARES. SHOULD SEE A FAIR AMOUNT OF
CLOUDS AS CONVECTIVE DEBRIS CLOUDS WILL BE STEERED EAST MIXED WITH
CU FIELD ACROSS THE AREA.
THE STALLED BOUNDARY WILL BEGIN TO LIFT NORTH THROUGH TONIGHT AND
EXPECT LOCALIZED CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS
OFF AFTER SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING
BEST CHC TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET
NIGHT WITH LOWS WELL ABOVE CLIMO...RUNNING IN THE MID 60S IN A WARM
AND HUMID AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...ATTENTION THROUGHOUT THE ENTIRE FORECAST
PERIOD WILL FOCUS ON UNSETTLED WEATHER...INCLUDING THE THREAT FOR
SEVERE WEATHER JUST AHEAD OF AN APPROACHING COLD FRONT. LATEST
GUIDANCE CONTINUES TO ILLUSTRATE A LONGWAVE TROUGH ACROSS THE CONUS
WITH A PERSISTENT UPPER LEVEL LOW WHICH WILL SLOWLY PROGRESS ACROSS
THE MIDWEST OVER THE NEXT COUPLE OF DAYS. WARM TEMPERATURES AND
SOUTHWEST FLOW WILL ALLOW FOR A MOISTURE-RICH ATMOSPHERE...AS
DEWPOINTS ARE WELL IN THE 60S...TO REMAIN IN PLACE WITH HIGHS ON
TUESDAY IN THE LOWER 80S ACROSS THE ENTIRE FORECAST AREA. SHOWERS
AND THUNDERSTORMS ARE EXPECTED THROUGHOUT THE DAY ON TUESDAY WHICH
IS IN GOOD AGREEMENT AS OUR AREA IS INCLUDED IN SPC`S SLIGHT RISK.
INTO WEDNESDAY...CONDITIONS WILL CONTINUE TO PROGRESS IN
INCREASE...AS IT LOOKS THE BETTER INSTABILITY AND LIFT WILL MOVE
INTO THE CENTRAL SC/NC/VA AREA...WITH A HEIGHTENED POSSIBILITY OF
SEVERE ESPECIALLY IN OUR WESTERN ZONES. DIFFICULTY WILL BE TIMING AS
MODELS HAVE EVER SO SLIGHTLY SLOWED DOWN THE PROGRESSION OF THE
SYSTEM IN PAST RUNS. HOWEVER...OVERALL ANTICIPATE MAIN THREAT TO
OCCUR WEDNESDAY THROUGHOUT THE DAY WITH AMPLE DIURNAL HEATING WITH
HIGHS ON WEDNESDAY AGAIN IN THE 80S...INTO EARLY THURSDAY MORNING.
WILL ALSO TAKE INTO ACCOUNT THE INTERACTION OF THE SEA BREEZE AS
WELL ON BOTH DAYS AND ANY OTHER WANDERING BOUNDARIES ABOUT THE AREA.
THE PRIMARY THREATS WILL BE HAIL AND DAMAGING WINDS...ALONG WITH THE
POSSIBILITY OF TORNADOES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...THURSDAY MAY BE RATHER ACTIVE. THE UPPER RIDGE
AXIS WILL BE OFFSHORE ALLOWING FOR DEEP SWRLY FLOW. SURFACE BOUNDARY
AND UPPER LEVEL VORT MAXES MAY SPONSOR DEEP ENOUGH LIFT FOR FAIRLY
WIDESPREAD CONVECTION. WIND FIELDS MAY BE STRONG ENOUGH FOR STORM
ORGANIZATION WITH DAMAGING WIND AND/OR HAIL. MORE QUESTIONABLE
WHETHER OR NOT INSTABILITY MANAGES TO DEVELOP HOWEVER. BOUNDARY
PUSHES OFFSHORE THURSDAY NIGHT WHICH MAY ALLOW FOR A COOLER AND
DRIER FRIDAY. TRAILING UPPER ENERGY ON SATURDAY BUT TOUGH CALL AS TO
WHETHER OR NOT ENOUGH MOISTURE AROUND FOR MEANINGFUL RAIN CHANCES.
DRY WNW FLOW FOR SUNDAY AND MONDAY.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AS OF 18Z..STILL LOOKING FOR CONVECTION TO FIRE ALONG A DIFFUSE WARM
FRONT THIS AFTERNOON. MOST OF THE ACTIVITY WILL BE OVER THE NORTHERN
THIRD OF THE CWA...BUT COULD NOT RULE OUT WEAK CONVECTION TO THE
SOUTH ALONG THE SEA BREEZE BOUNDARY. BRIEF IFR PERIODS ARE
POSSIBLE...MAINLY AT LBT AND ILM. MOST OF THE ACTIVITY WILL END THIS
EVENING AS THE WARM FRONT WAVES NORTH. WITH THE SOUTHWESTERLY FLOW
TONIGHT...IFR STRATUS IS A REASONABLE BET. TUESDAY...BECOMING VFR
WITH ANOTHER ROUND OF CONVECTION POSSIBLE BY THE END OF THE FORECAST
PERIOD.
EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH THURSDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...QUIET MARINE CONDITIONS OVERALL THROUGH
THIS AFTERNOON. HIGH PRESSURE REMAINS OVER THE AREA WITH
LINGERING BOUNDARY LIFTING NORTH OF THE THE WATERS. GRADIENT
REMAINS LIGHT WITH SOUTH TO SOUTHEAST FLOW REMAINING UNDER 10 KT
THROUGH THE MORNING HOURS WITH SEAS 2 FT OR LESS. MAY SEE A FEW
LINGERING SHOWERS MAKE IT OVER THE WATERS JUST ALONG NORTHERN
PORTION OF LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...EXPECT SOUTH- SOUTHWEST FLOW TO PERSIST
THROUGH THE FORECAST PERIOD WITH INCREASING WINDS WEDNESDAY INTO
WEDNESDAY EVENING WHERE WINDS WILL INCREASE TO AROUND 20 TO 25
KTS...WHILE THE REMAINDER OF THE PERIOD ANTICIPATE 15 TO 20 KTS
WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE. AS
FOR SEAS...2 TO 4 FT WITH 5 FT POSSIBLE. COULD SEE 6 TO 7 FT
POSSIBLE IN THE OUTER WATERS WEDNESDAY INTO THURSDAY MORNING.
ANTICIPATE CONDITIONS WILL WARRANT A SMALL CRAFT ADVISORY
WEDNESDAY EVENING.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 PM MONDAY...PREFRONTAL FLOW REGIME ON THURSDAY PROBABLY
STRONG ENOUGH TO WARRANT A SMALL CRAFT ADVISORY. A WINDSHIFT TO A
MORE OFFSHORE DIRECTION THURSDAY NIGHT INTO FRIDAY PAIRED WITH A
DOWNWARD TREND IN THE WIND SPEED WILL ALLOW ADVISORY TO BE DROPPED.
OFFSHORE WINDS AND FAIRLY SEASONABLE SEAS CONTINUES INTO SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SGL
NEAR TERM...RGZ
SHORT TERM...SGL
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
230 PM EDT MON APR 28 2014
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST UNITED STATES WILL CONTINUE TO
BRING MILD SOUTHERLY WINDS TO THE REGION. SHOWERS AND THUNDERSTORMS
WILL INCREASE IN COVERAGE TODAY THROUGH WEDNESDAY AS A TROUGH OF LOW
PRESSURE APPROACHES FROM THE WEST. ANOTHER QUICK ROUND OF RAIN IS
POSSIBLE LATE FRIDAY AND SATURDAY BEFORE CONDITIONS DRY OUT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...INCREASINGLY WARM AND MORE UNSTABLE AIR MASS
WITH TEMPS INTO THE 80S MOST PLACES. MODELS STILL SHOW MID TO UPPER
RIDGE LINED UP THE SOUTHEAST COAST WHICH SHOULD HELP TO INHIBIT SOME
OF THE STRONGEST CONVECTION RUNNING SOUTH...BUT AS TEMPS WARMED INTO
THE 80S AND DEWPOINTS INTO THE MID 60S CLOSER TO 70 OVER SOUTH
CAROLINA. HRRR AND RUC SHOWING BEST CAPE LINED UP INLAND FROM SOUTH
TO NORTH TOWARD DARLINGTON AND MARLBORO...BUT MAIN FOCUS OF STRONGER
CONVECTION WILL BE ALONG THE LINGERING FRONTAL BOUNDARY JUST TO THE
NORTH OF LOCAL FORECAST AREA. EXPECT SCT CONVECTION OVER THE AREA
WITH MAIN FOCUS ALONG SEA BREEZE CONVERGENT BOUNDARY AND RUNNING
ALONG LINGERING FRONTAL BOUNDARY. JUST NORTH OF BOUNDARY STILL
SEEING TEMPS NOT EVEN REACHING 70 WITH COOLER AIR WEDGED IN.
BEST HELICITY WILL RUN ALONG WARM FRONT WITH VALUES ABOVE 200 JUST
TO NORTH. OVERALL SHOULD BE RATHER FINE BOUNDARY OF STRONGEST STORMS
AS FORCING REMAINS WEAKER FARTHER SOUTH DUE TO INCREASED SUBSIDENCE
WITH MID TO UPPER RIDGE OVER THE SOUTHEAST COAST. THE STEERING FLOW
WILL PUSH ANY SHWRS/TSTMS THAT DEVELOP TOWARD THE COAST BUT THE MORE
STABILIZED AIR BEHIND SEA BREEZE SHOULD KEEP THE IMMEDIATE COAST
FREE OF STORMS. KEPT POPS VERY CLOSE TO PREVIOUS FORECAST WITH ONLY
MINOR ADJUSTMENTS AND WILL UPDATE AS NEEDED ONCE CONVECTION FLARES.
SHOULD SEE CLOUDS BLANKET MUCH OF THE AREA THROUGH THIS AFTERNOON AS
CONVECTIVE DEBRIS CLOUDS WILL BE STEERED EAST AND HIGH CLOUDS WILL
SPILL OVER THE MID TO UPPER RIDGE INTO LOCAL AREA.
THE STALLED BOUNDARY WILL BEGIN TO LIFT NORTH THROUGH TONIGHT AND
EXPECT LOCALIZED CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS
OFF AFTER SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING
BEST CHC TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET
NIGHT WITH ABUNDANT CLOUD COVER AND LOWS WELL ABOVE CLIMO...RUNNING
IN THE MID 60S IN A WARM AND HUMID AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...ALL EYES WILL BE ON THE SYSTEM NOW MOVING ACROSS
THE CENTRAL U.S AS IT MAKES ITS MOVE ON THE EAST COAST. THE
GFS...WHICH I HAVE BEEN LEANING TOWARD FOR A FEW CYCLES NOW REMAINS
CONSISTENT WITH THE BEST LIFT AND MOISTURE COUPLING LATE WEDNESDAY
AND INTO THE MORNING HOURS THURSDAY. I HAVE INCREASED POPS BASICALLY
ACROSS THE BOARD MORE SO FOR THE LATER PERIODS. SPC CONTINUES TO
HAVE THE AREA IN A SLIGHT RISK FOR BOTH DAYS. TEMPERATURE GUIDANCE
IS IN GOOD AGREEMENT OUTSIDE OF DAYTIME HIGHS FOR WEDNESDAY WITH THE
NAM/MET NUMBERS ONCE AGAIN COOLER. INHERITED BLEND WILL SUFFICE FOR
NOW.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...THE FOCUS FOR THE EXTENDED BEGINS TO SHIFT FROM
THE LONG ADVERTISED SYSTEM THAT IS CURRENTLY PLODDING ACROSS THE
CENTRAL U.S TO A SECONDARY WAVE LATE IN THE PERIOD. THE LATEST
MEDIUM RANGE GUIDANCE CONTINUES TO ADVERTISE A WET SCENARIO MAINLY
ALONG THE COAST. I HAVE TWEAKED THE POPS FOR SATURDAY TO REPRESENT
MORE OF A COASTAL SYSTEM ALTHOUGH THERE IS STILL PLENTY OF TIME FOR
THIS TO CHANGE. POPS REMAIN IN THE FORECAST FOR THURSDAY AND FRIDAY
MOSTLY VIA THE LOWER CONFIDENCE IN THE PROGRESS OF THE INITIAL
SYSTEM. NO CHANGES TO THE TEMPERATURE FORECAST.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z..STILL LOOKING FOR CONVECTION TO FIRE ALONG A DIFFUSE WARM
FRONT THIS AFTERNOON. MOST OF THE ACTIVITY WILL BE OVER THE NORTHERN
THIRD OF THE CWA...BUT COULD NOT RULE OUT WEAK CONVECTION TO THE
SOUTH ALONG THE SEA BREEZE BOUNDARY. BRIEF IFR PERIODS ARE
POSSIBLE...MAINLY AT LBT AND ILM. MOST OF THE ACTIVITY WILL END THIS
EVENING AS THE WARM FRONT WAVES NORTH. WITH THE SOUTHWESTERLY FLOW
TONIGHT...IFR STRATUS IS A REASONABLE BET. TUESDAY...BECOMING VFR
WITH ANOTHER ROUND OF CONVECTION POSSIBLE BY THE END OF THE FORECAST
PERIOD.
EXTENDED OUTLOOK...SCATTERED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH THURSDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM MONDAY...QUIET MARINE CONDITIONS OVERALL THROUGH
THIS AFTERNOON. HIGH PRESSURE REMAINS OVER THE AREA WITH
LINGERING BOUNDARY LIFTING NORTH OF THE THE WATERS. GRADIENT
REMAINS LIGHT WITH SOUTH TO SOUTHEAST FLOW REMAINING UNDER 10 KT
THROUGH THE MORNING HOURS WITH SEAS 2 FT OR LESS. MAY SEE A FEW
LINGERING SHOWERS MAKE IT OVER THE WATERS JUST ALONG NORTHERN
PORTION OF LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...A SOUTH TO OCCASIONALLY SOUTHEAST FLOW WILL
PREVAIL THROUGH THE PERIOD. THE STRONGEST WINDS SHOULD OCCUR LATE
WEDNESDAY WHEN A RANGE OF 20-25 KNOTS. FOR THE MOST PART A RANGE OF
15-20 KNOTS SHOULD BE FAIRLY PERSISTENT BEFORE THIS. SEAS WILL
GRADUALLY BUILD FROM AN INITIAL RANGE OF 1-3 FEET TO 3-5 AND
POSSIBLY 4-6 FEET BY THE END OF SECOND HALF OF THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...THE MAIN ISSUE FOR THE MARINE COMMUNITY WILL BE
THE TIMING OF THE WIND SHIFT WITH THE FRONT ASSOCIATED WITH THE MAIN
INITIAL SYSTEM. THIS SHOULD OCCUR LATE THURSDAY/EARLY FRIDAY
ALTHOUGH CONFIDENCE IS LOW DUE TO THE SLOW NATURE OF THIS SYSTEM.
PRECEDING THIS...EXPECT A SOUTHWEST FLOW OF 15-20 KNOTS. FOR FRIDAY
EXPECT A LIGHTER AND MORE VARIABLE FLOW. SIGNIFICANT SEAS WILL BE
HOVERING AT OR JUST BELOW SMALL CRAFT CRITERIA THURSDAY 3-5 FEET
DROPPING SLIGHTLY FRIDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT MON APR 28 2014
.SYNOPSIS...A STALLED SURFACE BOUNDARY ACROSS CENTRAL NC WILL LIFT
NORTHWARD AS A WARM FRONT THIS AFTERNOON. A WARM...MOIST AND
UNSTABLE AIR MASS WILL RESIDE OVER CENTRAL NC TONIGHT THROUGH
WEDNESDAY NIGHT. A SERIES OF UPPER LEVEL DISTURBANCES WILL INTERACT
WITH THIS AIR MASS TRIGGERING SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 1040 AM MONDAY...
A WEAK COLD FRONT AND SHALLOW STABLE AIRMASS SETTLED SOUTH THROUGH
THE AREAS OVERNIGHT...MAKING IT ESSENTIALLY TO THE SC BORDER AND
CREATING A RATHER LARGE GRADIENT IN TEMPS AND DEWPOINTS. THE PARENT
SURFACE HIGH BEHIND THE FRONT WILL CONTINUE TO SUPPLY A
NORTHEASTERLY WIND TODAY...BUT WITH CLEARING ALREADY OCCURRING ACROSS
THE SOUTHERN PIEDMONT AND A SOUTHWESTERLY WIND AT 925MB...THE BOUNDARY
SHOULD MIX BACK TO THE NORTH TODAY. HIGHS FOR TODAY ARE TOUGH GIVEN
THE VARYING CLOUD COVER AND SLOWLY VEERING SURFACE WINDS ACROSS THE
SOUTH. TEMPS OVER PORTION OF SC HAVE ALREADY JUMPED INTO THE MID
AND UPPER 70S. ACROSS THE NORTH THE AMOUNT OF SUN IS A BIT MORE
UNCERTAIN...WITH ADDITIONAL CLOUD COVER MOVING EAST ACROSS THE BLUE
RIDGE. ADJUSTMENTS TO TEMP TRENDS YIELDS MID 60S NORTH TO LOWER 80S
SOUTH.
REGARDING CONVECTION... THE MAIN LIMITING FACTOR IS THE SHORTWAVE
RIDGE OVERHEAD...BUT FORECAST SOUNDINGS SUGGEST HEATING AND
MOISTURE RECOVER WILL BE ABLE TO OVERCOME THE MID-LEVEL CAP. THE
LATEST RAP RUNS SHOW AN INSTABILITY AXIS ON THE ORDER OF 500-1000
J/KG MLCAPE NOSING NORTH ACROSS THE SOUTHERN PIEDMONT BY
MIDDAY...WITH DESTABILIZATION TO THE EAST CROSS THE SANDHILLS AND
SOUTHERN COASTAL PLAIN WITH TIME. THE SEEMS TO MESH WELL WITH
SATELLITE TRENDS AND DEWPOINTS RECOVERING INTO THE MID TO UPPER
60S....SO AREAS SOUTH OF HWY 64 LOOK TO MOST FAVORABLE FOR
CONVECTION THIS AFTERNOON. BULK SHEAR WILL BE STRONGER TO THE
NORTH...BUT GUIDANCE SUGGESTS AS MUCH AS 30KT WHICH COULD SUPPORT
SOME MULTICELL CLUSTERS WITH A GENERAL MOTION FROM WEST TO EAST.
THE MAIN THREAT FROM STORMS WILL BE DAMAGING WINDS...THOUGH STORMS
FARTHER NORTH IN THE VICINITY OF THE RETREATING SURFACE BOUNDARY AND
BACKED SURFACE WINDS WILL ENCOUNTER GREATER SHEAR AND HAVE A BETTER
CHANCE OF ROTATING. AGAIN...THE THREAT OF SEVERE WEATHER IS
CONDITIONED UPON DEVELOPMENT OF STORMS...WHICH SHOULD BE MOSTLY
SCATTERED IN NATURE. -SMITH
TONIGHT...SFC FRONT PROJECTED TO BE STALLED ACROSS THE NORTHERN
COUNTIES. WEAK CONVERGENCE ALONG THIS FEATURE WILL MAINTAIN A
THREAT FOR SCATTERED SHOWERS THROUGH THE NIGHT. EXPECT SHOWERS TO BE
MORE ISOLATED ACROSS THE SOUTH. RATHER MILD TONIGHT WITH MIN TEMPS
NO LOWER THAN THE MID 60S ACROSS THE SOUTH...TRENDING TO THE UPPER
50S/NEAR 60 SOUTH.
TUESDAY AND TUESDAY NIGHT...ACTIVE WEATHER PATTERN APPEARS LIKELY
ACROSS CENTRAL NC WITH A CHANCE FOR MORE THAN ONE ROUND OF STRONG TO
SEVERE STORMS.
THE DEEP LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS/MID MS VALLEY
WILL REMAIN NEARLY STATIONARY THIS PERIOD. A SERIES OF UPPER LEVEL
DISTURBANCES WILL ROTATE AROUND THIS LOW SIMILAR TO SPOKES AROUND
TEH CENTER OF A WHEEL. AS A DISTURBANCE CROSSES CENTRAL NC AND
INTERACTS WITH THE WARM MOIST UNSTABLE AIR MASS IN PLACE...EXPECT
SCATTERED TO NUMEROUS SHOWERS AND STORMS TO OCCUR. BASED ON MODEL
TIMING 9WHICH WILL LIKELY CHANGE OR ADJUST IN LATER MODEL
RUNS)...APPEARS FIRST ROUND OF SHOWERS AND STORMS WILL CROSS THE
REGION TUESDAY AFTERNOON WITH ANOTHER ROUND LATE TUESDAY NIGHT. WIND
PROFILES TUESDAY AFTERNOON ARE SUPPORTIVE OF STRONG UPDRAFTS WITH
LOW LEVEL HELICITY VALUES IN THE 150-300 M2/S2 RANGE LATE TUESDAY
INTO TUESDAY NIGHT. IN ADDITION...STRONG LIFT EXPECTED THROUGH TEH
COLUMN AS CENTRAL NC WILL BE IN THE RIGHT ENTRANCE REGION OF A 100-
110KT UPPER JET. THUS...POTENTIAL FOR A FEW SEVERE STORMS TUESDAY
AFTERNOON AND TUESDAY NIGHT WITH A FEW TORNADOES PROBABLE.
ALSO...POTENTIAL FOR STORMS TO REPEAT ACROSS THE SAME AREA. WITH
PRECIP WATER VALUES 1.5-1.75 INCHES PROJECTED...THIS SUGGEST THAT
THE HEAVY SHOWERS AND STORMS WILL BE CAPABLE FOR PRODUCING HEAVY
RAIN...LEADING TO FLOODING IN URBANIZED AREAS (AND EVENTUALLY SOME
RIVER FLOODING).
MAX TEMPS TUESDAY DEPENDENT UPON WHETHER THE SFC BOUNDARY LIFTS
ENTIRELY INTO VA OR LAGS ALONG OUR NORTHERN COUNTIES. APPEARS TO BE
ENOUGH OF A SLY FETCH JUST ABOVE THE SFC TO PUSH THE BOUNDARY NWD SO
HAVE LEANED TOWARD THE WARMER GUIDANCE FOR TUESDAY. MAX TEMPS MID
70S FAR NORTH-NW TO THE LOWER 80S SOUTH. MIN TEMPS TUESDAY NIGHT LOW
60S FAR NORTH-NW TO MID-UPPER 60S ELSEWHERE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 240 PM MONDAY...
FOR WED/WED NIGHT: LOOKS LIKE ANOTHER ROUND OF STRONG TO POSSIBLY
SEVERE STORMS LATE WED INTO WED NIGHT... ALTHOUGH THE DEGREE OF
THREAT WILL DEPEND LARGELY ON THE EXTENT OF CLOUDINESS WED MORNING
AND ITS IMPACT ON INSTABILITY HEADING THROUGH THE DAY. THE POTENT
MID LEVEL VORTEX WILL WOBBLE SLOWLY EASTWARD ACROSS THE UPPER
MIDWEST/WRN GREAT LAKES AS AN 80 KT MID LEVEL JET STREAK TRACKS UP
ALONG THE SRN/CENTRAL APPALACHIANS/FOOTHILLS... WITH UPPER
DIVERGENCE MAXIMIZING OVER THE ERN HALF OF NC LATE IN THE DAY.
PROVIDED THAT TUE NIGHT`S CONVECTIVE DEBRIS CLOUDS CAN CLEAR OUT OF
CENTRAL/ERN NC BY MID AFTERNOON AND ALLOW FOR SOME INSOLATION... WE
MAY ACHIEVE MUCAPE VALUES OF 1000-2000 J/KG COINCIDENT WITH DEEP
LAYER SHEAR OF 30-40 KTS. FORECAST HODOGRAPHS REMAIN BROADLY CURVED
WED WITH 0-3 KM HELICITY OVER 200 M2/S2... EHI EXCEEDING 2.5... AND
VGP OVER 0.3 M/S2... SUGGESTING ROTATING UPDRAFTS ARE A GOOD BET
GIVEN ENOUGH ASCENT VIA DYNAMIC AND THERMODYNAMIC PROCESSES. WILL
CONTINUE TO HIGHLIGHT THE SEVERE THREAT FOR WED AFTERNOON/EVENING
FOR ALL OF CENTRAL NC... FOR THE POSSIBILITY OF DAMAGING WIND-
PRODUCING BOWING SEGMENTS AND/OR SUPERCELLS PRODUCING A FEW
TORNADOES. EQUALLY AS CONCERNING IS THE THREAT FOR REPEATED BOUTS OF
TRAINING CONVECTIVE BANDS/CLUSTERS GENERATING EXTENDED PERIODS OF
HEAVY RAINFALL... AS MUCH AS 2-4 INCHES FROM TUE THROUGH WED NIGHT.
LARGE SCALE MODELS AGREE ON THIS PATTERN WITH THE GREATEST TOTALS
FROM THE NC MOUNTAINS THROUGH THE PIEDMONT... AND GIVEN PROJECTIONS
OF PW VALUES WELL OVER 200% OF NORMAL FROM LATE TUE LASTING THROUGH
WED NIGHT AND A DEEP WARM LAYER OVER 3.5 KM FAVORING WARM RAIN
PROCESSES... IT IS NEARLY CERTAIN THAT THE FLOODING THREAT WILL
EXTEND THROUGH WED NIGHT. CONSIDERABLE STREET FLOODING... SWOLLEN
CREEKS... AND SIGNIFICANT RISES ON MAINSTEM RIVERS ARE ALL POSSIBLE.
MAX TEMPS ARE A TOUGH CALL GIVEN THE UNCERTAINTY AS TO HOW MUCH
SUNSHINE WE`LL GET... BUT MODEL TRENDS AND THICKNESSES WITH STRONG
WARM AIR ADVECTION SUPPORT RAISING HIGHS A BIT TO 77-84. THE COLD
FRONT IS LIKELY TO SLOW TO A CRAWL AS IT EASES EASTWARD INTO THE FAR
WRN PIEDMONT WED NIGHT AS IT BECOMES PARALLEL TO THE STEERING FLOW
AND LOSES FORWARD MOMENTUM. THE LOSS OF HEATING AND THE WANING
DYNAMIC FORCING AS THE MID LEVEL FLOW FLATTENS SHOULD RESULT IN A
DECREASING SEVERE THREAT OVERNIGHT. THE STRONG LOW LEVEL MOISTURE
TRANSPORT WILL SLOWLY SHIFT EASTWARD INTO ERN NC LATE... AS SHOULD
THE GREATEST PW VALUES... LIKELY RESULTING IN A DIMINISHING FLOODING
THREAT LATE (ALTHOUGH STREET AND RIVER FLOODING MAY BE ONGOING).
WITH WARM SW FLOW AND PLENTIFUL CLOUD COVER... EXPECT MILD LOWS OF
60-67.
FOR THU/THU NIGHT: WHAT APPEARS TO BE DEPICTED AS A PREFRONTAL
TROUGH SHIFTS INTO THE COASTAL AREAS OF NC BY THU MORNING WITH THE
PRIMARY FRONT STILL HANGING BACK OVER WRN NC WHILE BECOMING
INCREASINGLY DIFFUSE. THE LOW LEVEL MOISTURE TRANSPORT AND PW REMAIN
ELEVATED OVER ERN NC... NECESSITATING A CONTINUED GOOD CHANCE OF
SHOWERS AND ISOLATED STORMS IN THE COASTAL PLAIN THROUGH THU...
WHILE THE NW CWA SHOULD SEE GENERALLY DRY WEATHER AND FAIR SKIES.
SHORTWAVE ENERGY RIDING NE OVER THE SRN GREAT LAKES/ST LAWRENCE
VALLEY SHOULD HELP PUSH THE SURFACE FRONT TO OUR SE BY THU NIGHT...
LEADING TO DIMINISHED RAIN CHANCES AS LOW LEVEL FLOW BECOMES MORE
WESTERLY OR WNW. HIGHS 75-82. LOWS FROM 49 NW TO 57 EAST. -GIH
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
GIVEN THE MID LEVEL TROUGH AXIS IS EXPECTED TO REMAIN TO OUR WEST
UNTIL LATE SATURDAY/SATURDAY NIGHT WITH THE SURFACE FRONT EXPECTED
TO LINGER NEAR THE COAST THROUGH SATURDAY MORNING... EXPECT WE COULD
SEE SOME MORE SHOWERS AND EVEN SOME STORMS... WITH THE HIGHEST
PROBABILITIES ACROSS OUR FAR EAST/SOUTHEASTERN AREAS. DRY WEATHER IS
EXPECTED TO RETURN FOR SUNDAY. EXPECT HIGH TEMPS WILL BE IN THE 70S
TO NEAR 80 EAST ON THURSDAY... WITH HIGH TEMPS GENERALLY AROUND 70
TO THE MID 70S FOR FRIDAY THROUGH SUNDAY. LOW TEMPS WILL BE IN THE
40S AND 50S FOR THIS TIME FRAME.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 150 PM MONDAY...
UNSETTLED WEATHER WILL PERSIST THROUGH MIDWEEK... AS A POWERFUL
STORM SYSTEM HOLDS OVER THE CENTRAL STATES... WITH A WARM FRONT
EXTENDING EASTWARD THROUGH OUR REGION AND A MOIST LOW LEVEL FLOW
FROM THE SOUTHWEST GRADUALLY DEVELOPING OVER NC. AVIATION CONDITIONS
NOW VARYING FROM MVFR TO LOW-END VFR ARE EXPECTED TO PERSIST THROUGH
THIS AFTERNOON... WITH VFR CONDITIONS DOMINATING AT MOST SITES AFTER
20Z. CONDITIONS ARE LIKELY TO WORSEN BY EARLY THIS EVENING WITH A
GOOD CHANCE OF MVFR VSBYS IN SHOWERS AND STORMS. THIS IS LIKELY TO
BE FOLLOWED BY LOWERING CIGS TO IFR/LIFR LATE TONIGHT AS LOW STRATUS
FORMS OVER THE AREA. WHILE WE`RE UNLIKELY TO MEET LLWS CRITERIA
TONIGHT... WINDS THAT ARE FROM THE SE AT 5-10 KTS AT THE SURFACE
WILL VEER WITH HEIGHT TO SW AT 25-30 KTS AROUND 1500 FT AGL LATE
TONIGHT... WHICH MAY CAUSE DIFFICULTY IN HANDLING SOME AIRCRAFT. THE
THREAT OF PATCHY SHOWERS AND A STORM OR TWO WILL LINGER OVERNIGHT...
THEN MORE ORGANIZED AND STRONGER STORMS ARE EXPECTED TO FORM TUE
AFTERNOON... AS CIGS RISE TO MVFR TOWARD THE END OF THE TAF VALID
PERIOD... WITH SURFACE WINDS BECOMING SOUTHERLY OR SOUTHWESTERLY AND
INCREASING TO AROUND 15 KTS AS THE WARM FRONTAL ZONE SURGES NORTH OF
CENTRAL NC.
LOOKING BEYOND 18Z TUE... AVIATION INTERESTS SHOULD CLOSELY MONITOR
THE LATEST CONDITIONS TUE AFTERNOON THROUGH WED EVENING... AS THERE
IS A HEIGHTENED RISK OF STRONG TO SEVERE STORMS... ANY OF WHICH
COULD PRODUCE DANGEROUS AVIATION WEATHER. OTHERWISE... EXPECT MAINLY
MVFR CIGS THROUGH THE REST OF TUE AFTERNOON WITH GUSTY WINDS FROM
THE SW AND A PEAK IN STORM COVERAGE INTO TUE EVENING. IFR/LIFR
CIGS/VSBYS LIKELY TO RESUME AFTER 05Z WED... IMPROVING SLOWLY TO
MVFR BY 16Z WED WITH ANOTHER PEAK IN STORM COVERAGE EXPECTED LATE
WED AFTERNOON INTO THE EVENING. EXPECT A COLD FRONT TO SHIFT INTO
CENTRAL NC AND WEAKEN EARLY THU... RESULTING IN PROBABLE VFR
CONDITIONS AT GSO/INT AND MVFR/IFR HOLDING AT RDU/RWI/FAY THU.
CONTINUED UNSETTLED FRI ESPECIALLY IN EASTERN TERMINALS WITH
POSSIBLE MVFR CONDITIONS PERSISTING. VFR CONDITIONS EXPECTED SAT.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...HARTFIELD
LONG TERM...BSD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
150 PM EDT MON APR 28 2014
.SYNOPSIS...A STALLED SURFACE BOUNDARY ACROSS CENTRAL NC WILL LIFT
NORTHWARD AS A WARM FRONT THIS AFTERNOON. A WARM...MOIST AND
UNSTABLE AIR MASS WILL RESIDE OVER CENTRAL NC TONIGHT THROUGH
WEDNESDAY NIGHT. A SERIES OF UPPER LEVEL DISTURBANCES WILL INTERACT
WITH THIS AIR MASS TRIGGERING SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM MONDAY...
A WEAK COLD FRONT AND SHALLOW STABLE AIRMASS SETTLED SOUTH THROUGH
THE AREAS OVERNIGHT...MAKING IT ESSENTIALLY TO THE SC BORDER AND
CREATING A RATHER LARGE GRADIENT IN TEMPS AND DEWPOINTS. THE PARENT
SURFACE HIGH BEHIND THE FRONT WILL CONTINUE TO SUPPLY A
NORTHEASTERLY WIND TODAY...BUT WITH CLEARING ALREADY OCCURRING ACROSS
THE SOUTHERN PIEDMONT AND A SOUTHWESTERLY WIND AT 925MB...THE BOUNDARY
SHOULD MIX BACK TO THE NORTH TODAY. HIGHS FOR TODAY ARE TOUGH GIVEN
THE VARYING CLOUD COVER AND SLOWLY VEERING SURFACE WINDS ACROSS THE
SOUTH. TEMPS OVER PORTION OF SC HAVE ALREADY JUMPED INTO THE MID
AND UPPER 70S. ACROSS THE NORTH THE AMOUNT OF SUN IS A BIT MORE
UNCERTAIN...WITH ADDITIONAL CLOUD COVER MOVING EAST ACROSS THE BLUE
RIDGE. ADJUSTMENTS TO TEMP TRENDS YIELDS MID 60S NORTH TO LOWER 80S
SOUTH.
REGARDING CONVECTION... THE MAIN LIMITING FACTOR IS THE SHORTWAVE
RIDGE OVERHEAD...BUT FORECAST SOUNDINGS SUGGEST HEATING AND
MOISTURE RECOVER WILL BE ABLE TO OVERCOME THE MID-LEVEL CAP. THE
LATEST RAP RUNS SHOW AN INSTABILITY AXIS ON THE ORDER OF 500-1000
J/KG MLCAPE NOSING NORTH ACROSS THE SOUTHERN PIEDMONT BY
MIDDAY...WITH DESTABILIZATION TO THE EAST CROSS THE SANDHILLS AND
SOUTHERN COASTAL PLAIN WITH TIME. THE SEEMS TO MESH WELL WITH
SATELLITE TRENDS AND DEWPOINTS RECOVERING INTO THE MID TO UPPER
60S....SO AREAS SOUTH OF HWY 64 LOOK TO MOST FAVORABLE FOR
CONVECTION THIS AFTERNOON. BULK SHEAR WILL BE STRONGER TO THE
NORTH...BUT GUIDANCE SUGGESTS AS MUCH AS 30KT WHICH COULD SUPPORT
SOME MULTICELL CLUSTERS WITH A GENERAL MOTION FROM WEST TO EAST.
THE MAIN THREAT FROM STORMS WILL BE DAMAGING WINDS...THOUGH STORMS
FARTHER NORTH IN THE VICINITY OF THE RETREATING SURFACE BOUNDARY AND
BACKED SURFACE WINDS WILL ENCOUNTER GREATER SHEAR AND HAVE A BETTER
CHANCE OF ROTATING. AGAIN...THE THREAT OF SEVERE WEATHER IS
CONDITIONED UPON DEVELOPMENT OF STORMS...WHICH SHOULD BE MOSTLY
SCATTERED IN NATURE. -SMITH
TONIGHT...SFC FRONT PROJECTED TO BE STALLED ACROSS THE NORTHERN
COUNTIES. WEAK CONVERGENCE ALONG THIS FEATURE WILL MAINTAIN A
THREAT FOR SCATTERED SHOWERS THROUGH THE NIGHT. EXPECT SHOWERS TO BE
MORE ISOLATED ACROSS THE SOUTH. RATHER MILD TONIGHT WITH MIN TEMPS
NO LOWER THAN THE MID 60S ACROSS THE SOUTH...TRENDING TO THE UPPER
50S/NEAR 60 SOUTH.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
TUESDAY AND TUESDAY NIGHT...ACTIVE WEATHER PATTERN APPEARS LIKELY
ACROSS CENTRAL NC WITH A CHANCE FOR MORE THAN ONE ROUND OF STRONG TO
SEVERE STORMS.
THE DEEP LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS/MID MS VALLEY
WILL REMAIN NEARLY STATIONARY THIS PERIOD. A SERIES OF UPPER LEVEL
DISTURBANCES WILL ROTATE AROUND THIS LOW SIMILAR TO SPOKES AROUND
TEH CENTER OF A WHEEL. AS A DISTURBANCE CROSSES CENTRAL NC AND
INTERACTS WITH THE WARM MOIST UNSTABLE AIR MASS IN PLACE...EXPECT
SCATTERED TO NUMEROUS SHOWERS AND STORMS TO OCCUR. BASED ON MODEL
TIMING 9WHICH WILL LIKELY CHANGE OR ADJUST IN LATER MODEL
RUNS)...APPEARS FIRST ROUND OF SHOWERS AND STORMS WILL CROSS THE
REGION TUESDAY AFTERNOON WITH ANOTHER ROUND LATE TUESDAY NIGHT. WIND
PROFILES TUESDAY AFTERNOON ARE SUPPORTIVE OF STRONG UPDRAFTS WITH
LOW LEVEL HELICITY VALUES IN THE 150-300 M2/S2 RANGE LATE TUESDAY
INTO TUESDAY NIGHT. IN ADDITION...STRONG LIFT EXPECTED THROUGH TEH
COLUMN AS CENTRAL NC WILL BE IN THE RIGHT ENTRANCE REGION OF A 100-
110KT UPPER JET. THUS...POTENTIAL FOR A FEW SEVERE STORMS TUESDAY
AFTERNOON AND TUESDAY NIGHT WITH A FEW TORNADOES PROBABLE.
ALSO...POTENTIAL FOR STORMS TO REPEAT ACROSS THE SAME AREA. WITH
PRECIP WATER VALUES 1.5-1.75 INCHES PROJECTED...THIS SUGGEST THAT
THE HEAVY SHOWERS AND STORMS WILL BE CAPABLE FOR PRODUCING HEAVY
RAIN...LEADING TO FLOODING IN URBANIZED AREAS (AND EVENTUALLY SOME
RIVER FLOODING).
MAX TEMPS TUESDAY DEPENDENT UPON WHETHER THE SFC BOUNDARY LIFTS
ENTIRELY INTO VA OR LAGS ALONG OUR NORTHERN COUNTIES. APPEARS TO BE
ENOUGH OF A SLY FETCH JUST ABOVE THE SFC TO PUSH THE BOUNDARY NWD SO
HAVE LEANED TOWARD THE WARMER GUIDANCE FOR TUESDAY. MAX TEMPS MID
70S FAR NORTH-NW TO THE LOWER 80S SOUTH. MIN TEMPS TUESDAY NIGHT LOW
60S FAR NORTH-NW TO MID-UPPER 60S ELSEWHERE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
WEDNESDAY AND WEDNESDAY NIGHT: THE DEEP MID LEVEL LOW AND SURFACE
LOW ARE EXPECTED TO LINGER ACROSS THE UPPER MIDWEST AND GREAT LAKES
REGION ON WEDNESDAY AND WEDNESDAY NIGHT WITH THE SYSTEM QUITE
WRAPPED UP AND OCCLUDED. THIS WILL RESULT IN STRONG SOUTH-
SOUTHWESTERLY MID LEVEL FLOW ACROSS OUR REGION ALONG WITH A SLOW
APPROACHING COLD FRONT. EXPECT THE HEAVIEST AND MORE WIDESPREAD
PRECIP WILL BE ACROSS WESTERN PORTIONS OF THE AREA ON WEDNESDAY.
THIS MAY LEAD TO A DECENT DIFFERENTIAL HEATING BOUNDARY SETTING UP
ACROSS THE REGION. GIVEN DEEP LAYER SHEAR VALUES ARE EXPECTED TO BE
AROUND 35 TO 50 KTS WEDNESDAY AFTERNOON INTO THE EVENING... WITH THE
POTENTIAL FOR UPWARDS OF 1000 TO 2000 J/KG OF MLCAPE FOR LOCATIONS
THAT WARM UP NICELY AND SEE A BIT LESS RAIN... EXPECT WE WILL HAVE A
THREAT FOR SEVERE STORMS. IF WE INDEED SEE A BOUNDARY SET UP OR
LINGERING BOUNDARY FROM EARLIER THEN WE COULD SEE AN INCREASE RISK
FOR TORNADOES... AS 0-1 KM SRH VALUES ARE EXPECTED TO BE IN THE 150
TO 400 M2/S2 RANGE WITH RIGHT LOOPING HODOGRAPHS. GIVEN THE
IMPRESSIVE DEEP LAYER SHEAR AND POSSIBLE MODERATE INSTABILITY...
SUPERCELLS WILL BE POSSIBLE... WITH DAMAGING WIND AND LARGE HAIL AS
WELL. IN ADDITION... WITH PW VALUES EXPECTED TO BE AROUND 1.5 INCHES
(WELL ABOVE NORMAL FOR THIS TIME OF YEAR) EXPECT THE SHOWERS AND
STORMS WILL PRODUCE HEAVY RAIN. THIS COUPLED WITH THE SLOW MOVING
FRONT WILL POSE A RISK FOR FLASH FLOODING AND RIVER FLOODING...
ESPECIALLY ACROSS THE WESTERN PIEDMONT (WHERE SEVERAL DAYS WORTH OF
MODERATE TO HEAVY RAIN MAY LEAD TO 3 TO 4+ INCHES OF RAINFALL). THE
MAIN AXIS OF SHOWERS AND STORMS WILL BEGIN TO SLOWLY SHIFT EASTWARD
BY EARLY THURSDAY MORNING AS THE SURFACE COLD FRONT BEGINS TO PUSH
THROUGH THE AREA... WITH THE MAIN AREAS OF SHOWERS AND STORMS FROM
GENERALLY RALEIGH EASTWARD BY MIDNIGHT THURSDAY.
TEMPS ON WEDNESDAY WILL BE TRICKY AND DRIVEN BY CLOUDS AND PRECIP.
FOR NOW WILL SHOW HIGHS IN THE WEST (WHERE THE MOST RAIN IS
EXPECTED) IN AROUND THE MID 70S (CLOSER TO THE COOL SIDE OF
GUIDANCE) TO THE LOWER 80S SE. LOWS THURSDAY MORNING SHOULD REMAIN
MILD WITH AT LEAST CONTINUED LINGERING LOW LEVEL CLOUD COVER.
THUS... WILL GO WITH LOWS IN THE LOWER 60S WEST TO UPPER 60S EAST.
THURSDAY THROUGH SUNDAY: THE COLD FRONT WILL SLOWLY MOVE ACROSS
CENTRAL NC WEDNESDAY NIGHT/THURSDAY MORNING... WITH A FINAL
SECONDARY PUSH NOT COMING THROUGH UNTIL THURSDAY NIGHT/FRIDAY
MORNING. HOWEVER... WITH MID LEVEL DRY AIR FILTERING INTO THE
WESTERN/NORTHWESTERN HALF OF THE CWA ON THURSDAY EXPECT WE WILL
BEGIN TO DRY OUT A BIT IN PIEDMONT ON THURSDAY INTO THURSDAY NIGHT.
GIVEN THE MID LEVEL TROUGH AXIS IS EXPECTED TO REMAIN TO OUR WEST
UNTIL LATE SATURDAY/SATURDAY NIGHT WITH THE SURFACE FRONT EXPECTED
TO LINGER NEAR THE COAST THROUGH SATURDAY MORNING... EXPECT WE COULD
SEE SOME MORE SHOWERS AND EVEN SOME STORMS... WITH THE HIGHEST
PROBABILITIES ACROSS OUR FAR EAST/SOUTHEASTERN AREAS. DRY WEATHER IS
EXPECTED TO RETURN FOR SUNDAY. EXPECT HIGH TEMPS WILL BE IN THE 70S
TO NEAR 80 EAST ON THURSDAY... WITH HIGH TEMPS GENERALLY AROUND 70
TO THE MID 70S FOR FRIDAY THROUGH SUNDAY. LOW TEMPS WILL BE IN THE
40S AND 50S FOR THIS TIME FRAME.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 150 PM MONDAY...
UNSETTLED WEATHER WILL PERSIST THROUGH MIDWEEK... AS A POWERFUL
STORM SYSTEM HOLDS OVER THE CENTRAL STATES... WITH A WARM FRONT
EXTENDING EASTWARD THROUGH OUR REGION AND A MOIST LOW LEVEL FLOW
FROM THE SOUTHWEST GRADUALLY DEVELOPING OVER NC. AVIATION CONDITIONS
NOW VARYING FROM MVFR TO LOW-END VFR ARE EXPECTED TO PERSIST THROUGH
THIS AFTERNOON... WITH VFR CONDITIONS DOMINATING AT MOST SITES AFTER
20Z. CONDITIONS ARE LIKELY TO WORSEN BY EARLY THIS EVENING WITH A
GOOD CHANCE OF MVFR VSBYS IN SHOWERS AND STORMS. THIS IS LIKELY TO
BE FOLLOWED BY LOWERING CIGS TO IFR/LIFR LATE TONIGHT AS LOW STRATUS
FORMS OVER THE AREA. WHILE WE`RE UNLIKELY TO MEET LLWS CRITERIA
TONIGHT... WINDS THAT ARE FROM THE SE AT 5-10 KTS AT THE SURFACE
WILL VEER WITH HEIGHT TO SW AT 25-30 KTS AROUND 1500 FT AGL LATE
TONIGHT... WHICH MAY CAUSE DIFFICULTY IN HANDLING SOME AIRCRAFT. THE
THREAT OF PATCHY SHOWERS AND A STORM OR TWO WILL LINGER OVERNIGHT...
THEN MORE ORGANIZED AND STRONGER STORMS ARE EXPECTED TO FORM TUE
AFTERNOON... AS CIGS RISE TO MVFR TOWARD THE END OF THE TAF VALID
PERIOD... WITH SURFACE WINDS BECOMING SOUTHERLY OR SOUTHWESTERLY AND
INCREASING TO AROUND 15 KTS AS THE WARM FRONTAL ZONE SURGES NORTH OF
CENTRAL NC.
LOOKING BEYOND 18Z TUE... AVIATION INTERESTS SHOULD CLOSELY MONITOR
THE LATEST CONDITIONS TUE AFTERNOON THROUGH WED EVENING... AS THERE
IS A HEIGHTENED RISK OF STRONG TO SEVERE STORMS... ANY OF WHICH
COULD PRODUCE DANGEROUS AVIATION WEATHER. OTHERWISE... EXPECT MAINLY
MVFR CIGS THROUGH THE REST OF TUE AFTERNOON WITH GUSTY WINDS FROM
THE SW AND A PEAK IN STORM COVERAGE INTO TUE EVENING. IFR/LIFR
CIGS/VSBYS LIKELY TO RESUME AFTER 05Z WED... IMPROVING SLOWLY TO
MVFR BY 16Z WED WITH ANOTHER PEAK IN STORM COVERAGE EXPECTED LATE
WED AFTERNOON INTO THE EVENING. EXPECT A COLD FRONT TO SHIFT INTO
CENTRAL NC AND WEAKEN EARLY THU... RESULTING IN PROBABLE VFR
CONDITIONS AT GSO/INT AND MVFR/IFR HOLDING AT RDU/RWI/FAY THU.
CONTINUED UNSETTLED FRI ESPECIALLY IN EASTERN TERMINALS WITH
POSSIBLE MVFR CONDITIONS PERSISTING. VFR CONDITIONS EXPECTED SAT.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1159 AM EDT MON APR 28 2014
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST UNITED STATES WILL CONTINUE TO
BRING MILD SOUTHERLY WINDS TO THE REGION. SHOWERS AND THUNDERSTORMS
WILL INCREASE IN COVERAGE TODAY THROUGH WEDNESDAY AS A TROUGH OF LOW
PRESSURE APPROACHES FROM THE WEST. ANOTHER QUICK ROUND OF RAIN IS
POSSIBLE LATE FRIDAY AND SATURDAY BEFORE CONDITIONS DRY OUT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM MONDAY...EXPECT LOCALIZED CONVECTION MAINLY ALONG
LINGERING FRONT BASICALLY RUNNING ACROSS NORTH CAROLINA FROM WEST
TO EAST ALONG NORTHERN TIER COUNTIES OF FORECAST AREA. MOIST
SOUTHERLY FLOW OVER MOST OF CWA WITH TEMPS UP AROUND 80 AND
DEWPOINTS IN THE MID 60S RUNNING UP AGAINST NORTHERLY WINDS WITH
TEMPS CLOSER TO 70 AND DEWPOINTS IN THE 50S JUST NORTH OF LOCAL
FORECAST AREA. THIS BOUNDARY WILL REMAIN THE FOCUS FOR CONVECTION
THIS AFTERNOON BUT ALSO EXPECT CONVECTIVE DEVELOPMENT ALONG SEA
BREEZE CONVERGENT BOUNDARY. THE SEA BREEZE WILL BE SLOW TO MOVE
INLAND AS IT RUNS UP AGAINST A DECENT W-SW COMPONENT TO THE FLOW
ABOVE THE SURFACE. RUC AND HRRR SHOW SHWRS POPPING BETWEEN 1 AND 2
PM. THE STEERING FLOW WILL PUSH ANY SHWRS/TSTMS THAT DEVELOP
TOWARD THE COAST BUT THE MORE STABILIZED AIR BEHIND SEA BREEZE
SHOULD KEEP THE IMMEDIATE COAST FREE OF STORMS. KEPT POPS VERY
CLOSE TO PREVIOUS FORECAST WITH ONLY MINOR ADJUSTMENTS AND WILL
UPDATE AS NEEDED ONCE CONVECTION FLARES. SHOULD SEE CLOUDS BLANKET
MUCH OF THE AREA THROUGH THIS AFTERNOON AS CONVECTIVE DEBRIS
CLOUDS WILL BE STEERED EAST AND HIGH CLOUDS WILL SPILL OVER THE
MID TO UPPER RIDGE INTO LOCAL AREA
THE STALLED BOUNDARY WILL BEGIN TO LIFT SLOWLY NORTH THROUGH THE
DAY AND THIS MAY HELP TO SHIFT CONVECTION NORTH EVENTUALLY.
WITH MID TO UPPER RIDGE OVER THE SOUTHEAST AND MORE IN THE WAY OF
SUBSIDENCE THAN LIFT...DO NOT EXPECT MUCH IN THE WAY OF STRONG
THUNDERSTORMS IN WARM AIR MASS TO THE SOUTH OF FRONT. ALSO EXPECT LOCALIZED
CONVECTION TO SHUT DOWN AS HEATING OF THE DAY CUTS OFF AFTER
SUNSET. THEREFORE WILL TAPER OFF POPS AFTER SUNSET LEAVING BEST CHC
TO THE NORTH ALONG BOUNDARY. SHOULD BE A RELATIVELY QUIET NIGHT
WITH ABUNDANT CLOUD COVER AND LOWS WELL ABOVE CLIMO...RUNNING IN
THE MID 60S IN A WARM AND HUMID AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...ALL EYES WILL BE ON THE SYSTEM NOW MOVING ACROSS THE
CENTRAL U.S AS IT MAKES ITS MOVE ON THE EAST COAST. THE GFS...WHICH
I HAVE BEEN LEANING TOWARD FOR A FEW CYCLES NOW REMAINS CONSISTENT
WITH THE BEST LIFT AND MOISTURE COUPLING LATE WEDNESDAY AND INTO THE
MORNING HOURS THURSDAY. I HAVE INCREASED POPS BASICALLY ACROSS THE
BOARD MORE SO FOR THE LATER PERIODS. SPC CONTINUES TO HAVE THE AREA
IN A SLIGHT RISK FOR BOTH DAYS. TEMPERATURE GUIDANCE IS IN GOOD
AGREEMENT OUTSIDE OF DAYTIME HIGHS FOR WEDNESDAY WITH THE NAM/MET
NUMBERS ONCE AGAIN COOLER. INHERITED BLEND WILL SUFFICE FOR NOW.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...THE FOCUS FOR THE EXTENDED BEGINS TO SHIFT FROM THE
LONG ADVERTISED SYSTEM THAT IS CURRENTLY PLODDING ACROSS THE CENTRAL
U.S TO A SECONDARY WAVE LATE IN THE PERIOD. THE LATEST MEDIUM RANGE
GUIDANCE CONTINUES TO ADVERTISE A WET SCENARIO MAINLY ALONG THE
COAST. I HAVE TWEAKED THE POPS FOR SATURDAY TO REPRESENT MORE OF A
COASTAL SYSTEM ALTHOUGH THERE IS STILL PLENTY OF TIME FOR THIS TO
CHANGE. POPS REMAIN IN THE FORECAST FOR THURSDAY AND FRIDAY MOSTLY
VIA THE LOWER CONFIDENCE IN THE PROGRESS OF THE INITIAL SYSTEM. NO
CHANGES TO THE TEMPERATURE FORECAST.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 12..SOME LIGHT SHOWERS ARE MOVING THROUGH THE EASTERN PORTION
OF THE REGION. PRECIP IS FALLING MAINLY OUT OF MID CLOUD. VFR THIS
MORNING. MODELS ARE IN REASONABLY GOOD AGREEMENT IN INTRODUCING
CONVECTION THIS AFTERNOON OVER THE NORTHERN HALF OF THE
CWA...ASSOCIATED WITH A WARM FRONT AND RETURN MOISTURE FLOW.
MOISTURE IS FAIRLY DEEP...AND IF THE CONVECTIVE TEMP IS
REACHED...THERE SHOULD BE FAIRLY GOOD COVERAGE OF SHOWERS. MOST OF
THE ACTIVITY WILL END THIS EVENING AS THE WARM FRONT WAVES NORTH.
WITH THE SOUTHWESTERLY FLOW TONIGHT...IFR STRATUS IS A REASONABLE
BET.
EXTENDED OUTLOOK...ISOLATED AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS POSSIBLE THROUGH WEDNESDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM MONDAY...QUIET MARINE CONDITIONS OVERALL THROUGH
THIS AFTERNOON. HIGH PRESSURE REMAINS OVER THE AREA WITH
LINGERING BOUNDARY LIFTING NORTH OF THE THE WATERS. GRADIENT
REMAINS LIGHT WITH SOUTH TO SOUTHEAST FLOW REMAINING UNDER 10 KT
THROUGH THE MORNING HOURS WITH SEAS 2 FT OR LESS. MAY SEE A FEW
LINGERING SHOWERS MAKE IT OVER THE WATERS JUST ALONG NORTHERN
PORTION OF LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...A SOUTH TO OCCASIONALLY SOUTHEAST FLOW WILL
PREVAIL THROUGH THE PERIOD. THE STRONGEST WINDS SHOULD OCCUR LATE
WEDNESDAY WHEN A RANGE OF 20-25 KNOTS. FOR THE MOST PART A RANGE OF
15-20 KNOTS SHOULD BE FAIRLY PERSISTENT BEFORE THIS. SEAS WILL
GRADUALLY BUILD FROM AN INITIAL RANGE OF 1-3 FEET TO 3-5 AND
POSSIBLY 4-6 FEET BY THE END OF SECOND HALF OF THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...THE MAIN ISSUE FOR THE MARINE COMMUNITY WILL BE
THE TIMING OF THE WIND SHIFT WITH THE FRONT ASSOCIATED WITH THE MAIN
INITIAL SYSTEM. THIS SHOULD OCCUR LATE THURSDAY/EARLY FRIDAY
ALTHOUGH CONFIDENCE IS LOW DUE TO THE SLOW NATURE OF THIS SYSTEM.
PRECEDING THIS...EXPECT A SOUTHWEST FLOW OF 15-20 KNOTS. FOR FRIDAY
EXPECT A LIGHTER AND MORE VARIABLE FLOW. SIGNIFICANT SEAS WILL BE
HOVERING AT OR JUST BELOW SMALL CRAFT CRITERIA THURSDAY 3-5 FEET
DROPPING SLIGHTLY FRIDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1229 PM CDT MON APR 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT MON APR 28 2014
CURRENT WATER VAPOR IMAGERY SHOWS THE LOW IN THE MID LEVELS OF THE
ATMOSPHERE SPINNING AWAY RIGHT IN THE MIDDLE OF NEBRASKA...WITH THE
WELL ADVERTISED DRY SLOT ALOFT NOSING UP IN FRONT OF IT AND
ENCOMPASSING MUCH OF OUR FORECAST AREA. THE MOST PRONOUNCED DRYING
ALOFT IS ALONG THE I 29 CORRIDOR CURRENTLY. MODEL CONSENSUS IS GOOD
IN PROGGING THE LOW SLOWLY EASTWARD TOWARD SOUTHEAST IA BY VERY LATE
TONIGHT. THE SURFACE LOW FOLLOWS SUIT...AND IT LOOKS LIKE OUR ENTIRE
FORECAST AREA WILL BE PLACED NORTH OF THE WARM FRONT THROUGH TODAY
AND TONIGHT. THE BEST CHANCES FOR WIDESPREAD BENEFICIAL RAINFALL
TODAY WILL BE BEHIND THE INVERTED TROUGH WHICH WILL BE CONFINED TO
OUR FAR WESTERN ZONES APPROACHING CENTRAL SD. THE REST OF OUR AREA
WILL SEE LESS NUMEROUS SHOWERS AND RAINFALL. BUT THERE IS ENOUGH
ELEVATED INSTABILITY TO POP A THUNDERSTORM OR TWO ALMOST AT ANYTIME
THROUGHOUT THE ENTIRE DAY...ESPECIALLY WHEN A MICROSCALE AREA OF
WARM AIR ADVECTION DECIDES TO MOVE NORTHWARD WHICH THE MODELS CANNOT
HANDLE VERY WELL ON THAT SCALE. INTERESTINGLY...BOTH THE GFS AND GEM
PAINT A BROAD STRIPE OF DECENT QPF THIS AFTERNOON JUST NORTH OF THE
WARM FRONT FROM SIOUX CITY TO STORM LAKE. IN ADDITION...THE PAST FEW
RUNS OF THE HRRR ARE ALSO SHOWING THE POSSIBILITY OF DECENT
CONVECTION IN THOSE AREAS AGAIN DUE TO THE PROXIMITY OF THE WARM
FRONT JUST TO THE SOUTH. AT THIS TIME...IT LOOKS TOO STABLE FOR MUCH
IN THE WAY OF SEVERE WEATHER...AND ALSO THE WIND SHEAR IS NOT REAL
GREAT FROM SIOUX CITY TO STORM LAKE AS THE ENTIRE LOWEST 3
KILOMETERS HAS A WIND DIRECTION OUT OF THE EAST. ONE THING TO WATCH
FOR HOWEVER IS IF A ROGUE SEVERE STORM WHICH BLOWS UP FURTHER TO THE
SOUTHEAST NUDGES INTO THOSE AREAS BEFORE WEAKENING. TO THE
NORTH...KEPT THE COVERAGE OF POPS IN THE SCATTERED CATEGORY THIS
AFTERNOON ALONG THE I 29 CORRIDOR WHERE THE DRY SLOT ALOFT HAS THE
MOST IMPACT. BUT OTHER AREAS MAY START TO FILL IN MORE WITH RAINFALL
IN OUR FAR EAST AND INTO THE JAMES RIVER VALLEY FROM THE WEST AS
MOISTURE PROGS SATURATE UP BETTER ALOFT.
FEEL THERE IS NO NEED FOR A WIND ADVISORY TODAY AS SOUNDINGS ONLY
MIX TO ABOUT 925-900MB AREA WIDE. WINDS IN THAT LAYER ARE STOUT...
AVERAGING 30 TO 35 KNOTS...BUT USUALLY IT TAKES A LITTLE MORE THAN
THAT TO WARRANT A WIND ADVISORY IN OUR AREA...CLOSER TO 40 KNOTS.
HOWEVER TONIGHT ON THE BACK SIDE OF THE LOW...OUR FAR SOUTHWEST
ZONES MAY GET CLOSE TO ADVISORY CRITERIA AFTER MIDNIGHT. MUCH OF OUR
FORECAST AREA TONIGHT IS WELL PLACED IN THE UPPER LEFT QUADRANT OF
THE LOW TRACK TO RECEIVE PRECIP. THERE IS EVEN SOME WEAK TROWALING
IN THE 290-295K LAYER NUDGING INTO OUR AREA FROM THE EAST...AND
SATURATION LOOKS TO BE IN NO SHORT SUPPLY FROM THE SURFACE TO AROUND
500MB. IN THE EVENING...AGAIN THE I 29 CORRIDOR MAY NOT RECEIVE MUCH
RAIN...BUT PRECIP WILL FILL INTO THAT AREA OVERNIGHT. CONCERNING
TEMPERATURES...WITH A FEW BREAKS POSSIBLE NEAR THE WARM FRONT...
AREAS FROM YANKTON TO STORM LAKE AND SOUTHWARD SHOULD HIT 60 TO
65...PROGRESSIVELY COOLING OFF HEADING NORTHWARD. TONIGHT IS
TRICKY...AND HAD TO ADD IN A SNOW MIX TO OUR NORTHERN AND WESTERN
ZONES AS SURFACE TEMPERATURES COOL INTO THE MID 30S IN THOSE AREAS
COUPLED WITH SUB ZERO 850MB TEMPERATURES. USED THE MODEL CONSENSUS
850MB -2 DEGREE C AND 925MB ZERO DEGREE C ISOTHERMS FOR THE RAIN AND
SNOW LINES...COUPLED WITH TEMPERATURES NEAR 35.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM CDT MON APR 28 2014
TUESDAY WILL START FAIRLY RAINY OVER THE AREA...THOUGH AMOUNTS
SHOULD BE LESS THAN A QUARTER INCH FOR THE DAY. DRYING WILL BEGIN
FROM THE NORTH/NORTHEAST DURING THE AFTERNOON OVER THE WESTERN PART
OF THE FORECAST AREA AS SOME SUBSIDENCE SPREADS IN FROM THE NORTH/
NORTHEAST BETWEEN LOBES ROTATING AROUND THE UPPER LOW TO THE EAST.
FOR NOW WILL KEEP SOME VERY MINIMAL POPS IN THE WEST FOR TUESDAY
NIGHT...WHILE ONLY SHAVING POPS TO LOW LIKELIES ALONG OUR EASTERN
EDGE IN MN AND IA. FOR NOW AM GOING FOR ALL OF THIS PRECIPITATION TO
BE LIGHT RAIN EXCEPT MAYBE SOME MODERATE RAIN LINGERING TUESDAY
MORNING IN THE EAST...MAYBE WITH A BIT OF WET SNOW MIXED IN WEST AND
NORTH EARLY MORNING BUT NO ACCUMULATION. FOR TUESDAY NIGHT...THOUGH
TEMPERATURES ALOFT WILL BE MARGINAL FOR A LITTLE MIXED SNOW AGAIN...
THERE MAY BE NO PRECIPITATION AT ALL IN THE WEST WHICH WOULD HAVE
THE BETTER SHOT AT SOME SNOW. SURFACE AND NEAR SURFACE TEMPERATURES
WILL LIKELY BE A BIT TOO WARM WITH THE LIGHTER NATURE OF
PRECIPITATION...IF THERE IS ANY AROUND IN THE FIRST PLACE...AND
DYNAMIC COOLING WILL BE NIL. TO THE EAST...THE DEEPER MOIST AIR
SHOULD PRECLUDE ENOUGH COOLING TO GET SNOW TO THE SURFACE...AND EVEN
THERE THE PRECIPITATION SHOULD BE PRETTY LIGHT. TEMPERATURES WILL
NOT BE SHOWING A LOT OF SPREAD WITH 40S HIGHS AND 30S LOWS. IT WILL
STILL BE WINDY TUESDAY BUT EXPECT WINDS WILL STAY BELOW ADVISORY
CRITERIA.
WEDNESDAY WILL BRING THE NEXT LOBE ROTATING OVER THE AREA AND A
RESURGENCE OF LIGHT RAIN WEST/SOUTHWESTWARD AGAIN. TEMPERATURES
AGAIN WILL CLIMB INTO THE 40S AND IT WILL BE WINDY AGAIN. IT COULD
EVEN BE SLIGHTLY WINDIER THAN TUESDAY WITH THE LOBE PASSING OVER THE
AREA.
THURSDAY WILL BRING THE SYSTEM STARTING TO MOVE SLOWLY EAST OF THE
AREA AND WILL KEEP LIGHT RAIN POPS IN THE CHANCE CATEGORY. WEDNESDAY
NIGHT LOWS SHOULD BE IN THE 30S AGAIN...THOUGH IT MAY BE A DEGREE OR
TWO LESS COOL THERE WITH MODELS HINTING AT VERY SLIGHT LOW LEVEL
WARMING. WITH LESSER PRECIPITATION COVERAGE...THURSDAY DAY
TEMPERATURES ARE EXPECTED TO BE A TAD LESS COOL...UPPER 40S TO LOWER
50S FOR HIGHS. THIS PROCESS WILL CONTINUE ON FRIDAY...REMEMBER THE
SLOWNESS OF THIS SYSTEM...BUT POPS WILL BE PRETTY LOW WITH
PRECIPITATION CONFINED MAINLY TO EAST OF FSD. 50 TO 55 LOOKS RIGHT
FOR HIGHS FRIDAY.
THE WEEKEND SHOULD BE A LITTLE WARMER YET...BUT STILL BELOW
NORMAL...AHEAD OF A CANADIAN WAVE APPROACHING IN NORTHWEST FLOW
BEHIND THE CURRENT SYSTEM. WILL GO WITH THE EXTENDED GUIDANCE GRIDS
OF SHOWER CHANCE PEAKING ABOUT SATURDAY NIGHT. THIS SEEMS TO BE THE
BEST PLAN FOR NOW ON EITHER THE GFS OR EC SOLUTION. THE EC HAS
STRONGER RIDGING BETWEEN SYSTEMS THAN THE GFS AND WOULD BRING
TEMPERATURES A LITTLE CLOSER TO NORMAL FOR THE WEEKEND...BUT THE
LIGHT SHOWER THREAT IS STILL THERE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1228 CDT MON APR 28 2014
LINGERING SFC LOW WILL CONTINUE TO BRING IFR AND LOWER CONDITIONS
TO HON...FSD AND SUX. WAVES OF SHRA WITH LOWER VIS WILL CONTINUE THRU
THE TAF PD WITH CIGS JUPMING AROUND FROM 1KFT TO JUST BELOW 1KFT.
WIND WILL PICK UP AGAIN WITH GUSTS AROUND 30KTS BY TUES MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...
AVIATION...SALLY
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
514 PM CDT MON APR 28 2014
.MESOSCALE UPDATE...
LATEST LAPS DATA CLEARLY SHOWS THAT THE BETTER INSTABILITY IS OVER
OUR SOUTHERN AREAS WHICH IS WHERE THE TOR WATCH IS IN EFFECT. CAPE
VALUES...SHOWALTERS ALL IN SUPPORT OF THE SUBSTANTIAL AMOUNTS OF INSTABILITY
ACROSS THE SOUTH. CURRENT RADAR SHOWS THE STRONGEST ACTIVITY FROM
DICKSON COUNTY SOUTHWARD THROUGH GILES COUNTY WITH AGAIN...THE
STRONGEST ACTIVITY THE FURTHER SOUTH YOU GO.
WE DO SEE A LINE OF THUNDERSTORMS ATTEMPTING TO DEVELOP BACK
ACROSS WESTERN KY. HOWEVER...THERE IS A DEGREE OF INCREASING CAP
STRENGTH ACROSS OUR NORTHERN AREAS. THUS...IT MAY HAVE A TOUGH
TIME DEVELOPING INTO SOMETHING MORE SUBSTANTIAL. HRRR FURTHER
CONCURS WITH THE IDEA OF NO REDEVELOPMENT TONIGHT TO THE WEST OF
THE AFOREMENTIONED STRONGEST CONVECTION.
BIGGEST POTENTIAL IMPACT OVER THE NEXT FEW HOURS WILL BE OVER OUR
SOUTHERN AREAS WHERE THE POTENTIALLY TORNADIC CELLS COULD CLIP
OUR FAR SOUTHERN COUNTIES AND EVENTUALLY OUR SOUTHERN PLATEAU.
AS FOR THE FLOOD THREAT...THE FLASH FLOOD WATCH CONTINUES THROUGH
TUESDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 256 PM CDT MON APR 28 2014/
DISCUSSION...
..SIGNIFICANT SEVERE WEATHER THREAT STILL EXISTS OVER FAR
SOUTHERN MIDDLE TN THROUGH TONIGHT...
A STRONG LOW PRESSURE CENTER OVER EASTERN NEBRASKA WILL DRAG A
COLD FRONT THROUGH THE REGION LATE TONIGHT...WITH ITS UPPER LOW
LAGGING AND SPINNING ACROSS THE UPPER MIDWEST. STRONG DIVERGENCE
ALOFT ON THE NOSE OF A 115-KT UPPER JET HAS LED TO AMPLE PRECIP
ACROSS MIDDLE TN THIS MORNING THROUGH THE EARLY AFTERNOON HOURS.
THIS ACTIVITY HAS LED TO 3-5 INCH RAINFALL AMOUNTS MAINLY WEST OF
I-65 AND SOUTH OF I-40...WHERE RESIDUAL FLOODING AND FLASH
FLOODING CONTINUE. A FLASH FLOOD WATCH CONTINUES FOR ALL OF MIDDLE
TN AND WILL BE EXTENDED THROUGH TUESDAY AFTERNOON GIVEN THE RIVER
FLOODING THREAT FROM ADDITIONAL RAINS FROM THIS EVENING THROUGH
THE OVERNIGHT HOURS. WILL ISSUE THE UPDATED FLASH FLOOD WATCH SOON.
MORE INTERESTINGLY...THE MORNING CONVECTION DROPPED AN OUTFLOW
BOUNDARY ACROSS FAR SOUTHERN MIDDLE TN...WHERE POINTS NORTH OF
THAT BOUNDARY REMAIN IN THE COLD POOL REGION...AND POINTS ALONG
AND SOUTH OF THIS BOUNDARY REMAIN VERY UNSTABLE. THIS BOUNDARY
EVEN CURLS BACK TO THE WEST A BIT OVER OUR FAR EASTERN CWA. WITH
SFC CAPE VALUES AROUND 2000 J/KG AND AMPLE LOW-LEVEL SHEAR AS
WELL AS DEEP LAYER SHEAR SOUTH OF THIS BOUNDARY...SPC ISSUED A
PDS TORNADO WATCH FOR MAINLY OUR SOUTHERN TWO TIERS OF COUNTIES
UNTIL 9PM. ANYTHING CLOSEST TO THE HUNTSVILLE COUNTY WARNING AREA
WILL HAVE THE BEST CHANCE SEEING A SIGNIFICANT THREAT FOR
SUPERCELLS...WHICH MEANS A TORNADO...HAIL AND DAMAGING WIND
THREAT. TORNADOES ON THE GROUND HAVE BEEN REPORTED IN NORTHERN
MS ALREADY...MOVING NE. IT WILL BE A CLOSE CALL FOR FAR SOUTHERN
MIDDLE TN. FYI...WE WILL ADD GRUNDY COUNTY TO THE WATCH AS WELL.
ALSO...NORTH OF THIS BOUNDARY...SEVERE STORMS WILL STILL BE
POSSIBLE BUT HAIL WILL BE THE ONLY SEVERE WEATHER THREAT FOR
STORMS IN THE COLD POOL.
SUPERCELLS OVER MS SHOULD COAGULATE INTO A LARGE AREA OF
CONVECTION AND THIS SHOULD SPREAD NORTHWARD WITH TIME.
OVERNIGHT...THIS WILL MOVE EAST THROUGH MIDDLE TN...AND POPS COULD
TAPER FROM WEST TO EAST TOWARDS TUESDAY MORNING. AN ADDITIONAL 1-2
INCHES OF RAINFALL WILL BE POSSIBLE THROUGH TONIGHT...WITH LOWS
AROUND 60.
ON TUESDAY...THE SFC LOW SHOULD ROTATE A LITTLE FURTHER EAST AND
ANOTHER LOBE OF ENERGY FROM THE UPPER LOW WILL SWING THROUGH THE
REGION. WOULD THINK ANOTHER ROUND OF AFTERNOON-EVENING CONVECTION
SHOULD EASILY BE GENERATED...THIS TIME WITH MORE SHEAR ACROSS
MIDDLE TN...MORE SUNSHINE THROUGH THE MORNING HOURS...AND COLDER
AIR ALOFT WITH THE UPPER LOW GETTING CLOSER. WOULD EXPECT ANOTHER
ROUND OF SEVERE WEATHER TOMORROW AFTERNOON AND EVENING...WITH
LARGE HAIL AND DAMAGING WINDS THE BEST THREAT. EVEN AN ISOLATED
TORNADO OR TWO CAN NOT BE RULED OUT.
FINALLY THE SYSTEM WILL MOSTLY PULL OUT ON WEDNESDAY...WITH
PERHAPS SOME LINGERING SHOWERS INTO WEDNESDAY EVENING. TEMPS WILL
COOL OFF INTO THE 70S ON WEDNESDAY...AND EVEN COOLER THURSDAY-
SATURDAY IN THE 60S. CONDITIONS SHOULD MOSTLY BE DRY THURSDAY
ON...WITH TEMPS WARMING BACK UP TO NEAR 80 SUNDAY AND MONDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR TNZ005>011-023>034-
056>066-075-077>080-093>095.
&&
$$
21
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1243 PM CDT MON APR 28 2014
.DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED DURING THE TAF PERIOD
EXCEPT FOR MVFR/IFR CONDITIONS GENERALLY EAST OF U.S. ROUTE 281
OWING TO MIST/FOG DRG THE 07-13Z TUESDAY PERIOD. MODERATE NORTH
WIND THIS AFTN BECOMING LIGHT SOUTH/VARIABLE OVERNIGHT THEN
MODERATE NORTH WIND TUESDAY BY MID MORNING IN RESPONSE TO A COLD
FRONT.
&&
.PREV DISCUSSION... /ISSUED 635 AM CDT MON APR 28 2014/
DISCUSSION...SEE 12Z AVIATION DISCUSSION.
AVIATION...LOW CIGS/VSBYS RAPIDLY LIFTING AS WINDS HAVE SHIFTED.
WILL LIKELY JUST HAVE SOME TEMPO CONDITIONS ENDING BY NO LATER
THAN 14Z EASTERN TERMINALS. SHOULD MAINLY HAVE N-NW WINDS
ESPECIALLY BY 14Z WITH MAINLY CLEAR SKIES. SEA-BREEZE COMES IN
AGAIN LATE THIS AFTERNOON AND SHIFT WINDS SOUTHERLY STARTING ABOUT
20Z AT KCRP AND SPREADING WESTWARD. WINDS DIMINISH TONIGHT AND
MAINLY BECOME LIGHT AND VARIABLE OVERNIGHT. COULD HAVE SOME GROUND
FOG KCRP AND KVCT TOWARD END OF TAF PERIOD AS LIGHT WINDS AND
CLEAR SKIES CREATE FOG.
PREV DISCUSSION... /ISSUED 326 AM CDT MON APR 28 2014/
SHORT TERM (TODAY THROUGH TUESDAY)...WARM AND DRY TODAY AND TUESDAY
TOO (MOST AREAS)...AS COLD AIR IS EXPECTED TO LAG BEHIND THE FRONTAL
BOUNDARY ON TUESDAY. LOOKS LIKE ANOTHER HOT DAY...BUT NOT AS HOT AS
YESTERDAY AT LEAST OUT TO THE WEST AS BOUNDARY LAYER TEMPERATURES
ARE PROGGED TO BE SEVERAL DEGREES COOLER (SO IF THAT HAPPENS IT
SHOULD BE COOLER). 4KM RUC IS SHOWING TEMPERATURES TOPPING 100
DEGREE BARRIER OVER THE SOUTHERN AREAS...AND WILL GO 101/102 OVER
THE SOUTHWESTERN AREAS. OTHERWISE...MORNING LOW CLOUDS OVER THE EAST
WILL QUICKLY LIFT AND SHOULD SEE LOTS OF SUN WITH NORTHWEST WINDS AS
DRY LINE MOVES FARTHER EAST THAN YESTERDAY. LOW LEVEL MOISTURE IS
TOO SCOURED OUT FOR ANY MENTION OF RAIN (EVEN OFFSHORE) SO HAVE
REMOVED (4KM MODELS KEEP THINGS DRY TOO). FOR TONIGHT...ONLY NAM IS
BRINGING COOLER AIR MUCH FASTER THAN GFS/ECMWF (ALTHOUGH CANADIAN IS
COOL TOO...AS USUAL). AM GOING TO PREFER TO GO MORE ON THE WARM SIDE
TONIGHT ALTHOUGH IF WINDS ARE TOO LIGHT AND SURFACE MOISTURE IS TOO
LOW...WE COULD REALLY BOTTOM OUT (GIVEN WARM DAY EXPECTED TODAY WILL
PREFER TO STAY ON THE WARM SIDE THOUGH). COOLER AGAIN ON TUESDAY BUT
STILL WARMER THAN NORMAL WITH COLD AIR LAGGING ON FRONT. MAY SEE A
FEW 80S IN THE VICTORIA AREA. MOISTURE AGAIN TOO LIMITED FOR
PRECIPITATION.
MARINE (TODAY THROUGH TUESDAY)...HAVE EXTENDED THE SCA TIL 4 AM FOR
THE BAYS/WATERWAYS...AND LONGER FOR THE GULF WATERS. MAY NEED TO
EXTEND AGAIN AT THE LAST MINUTE IF WINDS STAY UP AGAIN. WINDS HAVE
STAYED UP LONGER THAN EXPECTED WITH GUSTS OVER 30 KNOTS AT KNGP.
4KM RUC HAS WINDS CRANKING TIL 12Z OR SO...BUT THIS IS NORMALLY ON
THE HIGH SIDE (BUT STILL DOING BETTER THAN NAM12 OR OTHER MODELS).
WINDS DO DECREASE BY SUNRISE...BUT SEAS STAY UP. THUS...THE GULF
WATER SCA WILL MAINLY BE FOR HIGH SEAS MONDAY...WITH SCA
CONDITIONS ENDING AROUND NOON. VISIBILITIES OVER THE MARINE AREAS
ARE BETWEEN 1 AND 3 MILES...AND THAT SHOULD CLEAR UP LATER THIS
MORNING. MORE FOG TONIGHT BUT THAT SHOULD BE OVER THE OFFSHORE
WATERS (IF THAT)...AS DRIER AIR DOES GET INTO THE NEARSHORE
WATERS. COULD NOT RULE OUT A ROGUE SHOWER NEAR MATAGORDA ISLAND
BUT THAT WILL BE VERY BRIEF AND UNLIKELY TO HAPPEN (SO NOT IN
FORECAST).
FIRE WEATHER (TODAY THROUGH TUESDAY)...FIRE WEATHER PROCEDURE IS
SHOWING ELEVATED CONDITIONS/ISOLATED CRITICAL OVER MUCH OF THE AREA
ON TUESDAY. FUEL DRYNESS FORECAST MAP IS SHOWING MOST AREAS IN
NORMAL MOISTURE..WITH ONLY A PART OF THE NORTHERN COASTAL BEND (LIVE
OAK AND PORTIONS OF BEE AND MCMULLEN COUNTIES) IN DRY FUELS. SINCE
THESE COUNTIES ARE FORECAST TO BE IN ELEVATED CONDITIONS ON
TUESDAY...NO NEED FOR FIRE WEATHER WATCH OR RED FLAG WARNING. DAY
SHIFT OR NEXT MID SHIFT CAN RE-EVALUATE...ESPECIALLY IF FUEL DRYNESS
MAP CHANGES THE NEXT DAY.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...PERIOD BEGINS WITH
COOLER TEMPERATURES AND DRY CONDITION IN WAKE OF TUESDAY/S/S FROPA.
BROAD LONGWAVE TROUGH CENTERED OVER THE FAR NORTH CENTRAL STATES
WILL KEEP FAIRLY ZONAL FLOW OVER SOUTH TEXAS THROUGH THURSDAY.
TROUGH WILL FINALLY SWING OVER THE REGION THURSDAY NIGHT INTO
FRIDAY. ECMWF CONTINUES TO BE THE WETTER SOLUTION WITH THIS PASSING
WHILE THE GFS/NAM STAY MOSTLY DRY OVERLAND. WHILE THERE IS THE UPPER
LEVEL SUPPORT FOR PERHAPS SOME SPRINKLES AND RAIN TO DEVELOP THERE IS
AN OVERALL LACK OF SUFFICIENT MOISTURE OVER MOST OF THE REGION
EXCEPT IN THE OVER THE OFFSHORE WATERS THURSDAY NIGHT INTO FRIDAY
MORNING. KEPT THE 20 POPS MENTION OVER THE OFFSHORE WATERS FOR
NOW...BUT EVEN THIS MAY BE GOING TOO HIGH. OTHERWISE EXPECT A
CONTINUED DRY FORECAST. TEMPERATURES WILL BE NICELY COOLER (BELOW
AVERAGE) THROUGH THE END OF THE WEEK BEFORE RETURNING TO NORMAL ON
BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 66 93 61 80 59 / 0 10 10 10 10
VICTORIA 63 88 55 81 51 / 0 10 10 10 10
LAREDO 69 98 62 86 60 / 0 10 10 10 10
ALICE 64 96 57 83 54 / 0 10 10 10 10
ROCKPORT 67 89 62 79 61 / 0 10 10 10 10
COTULLA 63 92 54 83 54 / 0 0 10 10 10
KINGSVILLE 65 97 60 81 57 / 0 10 10 10 10
NAVY CORPUS 67 87 65 79 65 / 0 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
WC/87...AVIATION
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1212 PM CDT MON APR 28 2014
.AVIATION...
MUCH DRIER AIR IS FILTERING INTO SOUTHEAST TEXAS RESULTING IN MOSTLY
CLEAR SKIES. SOME LOWER CLOUDS ARE EAST OF THE TAF SITES AND ALONG
THE COAST WHERE THE DEEPEST MOISTURE EXISTS...AND THAT IS WHERE THE
HRRR CONTINUES TO WANT TO DEVELOP SOME SHOWERS THIS AFTERNOON. WILL
MONITOR CLOSELY...BUT AT THIS TIME NOT CONFIDENT ENOUGH TO INCLUDE
ANY MENTION IN THE 18Z TAF PACKAGE. THERE IS A CHANCE THAT ENOUGH
MOISTURE COULD BE PRESENT OVERNIGHT FOR POSSIBLE LOW CLOUD AND FOG
DEVELOPMENT...FROM ROUGHLY CXO SOUTHWARD TO THE COAST. FOR NOW...WILL
ONLY MENTION THIS IN THE CXO AND LBX TAFS WHERE MODELS ARE HITTING
IT THE HARDEST. STRONG COLD FRONT WILL MOVE ACROSS SOUTHEAST TEXAS
TOMORROW MORNING AND OFF THE COAST LATE IN THE MORNING OR EARLY IN
THE AFTERNOON WITH GUSTY NORTH TO NORTHWEST WINDS BEHIND THE BOUNDARY.
NO SHOWERS OR THUNDERTORMS ARE EXPECTED WITH THE FRONT. 42
&&
.PREV DISCUSSION... /ISSUED 1058 AM CDT MON APR 28 2014/
DISCUSSION...
ADDED CLIMATE SECTION.
CLIMATE...
HIGH TEMPERATURES TODAY WILL LIKELY REACH 90 DEGREES. THE LAST
TIME THE CITY OF HOUSTON (KIAH) REACH 90 DEGREES WAS OCTOBER 5TH
OF LAST YEAR (93). THE LAST TIME COLLEGE STATION (CLL) REACHED 90
DEGREES WAS OCTOBER 1ST OF LAST YEAR (91). HERE ARE THE RECORDS
FOR THE THREE FIRST ORDER CLIMATE SITES FOR TODAY WITH THEIR
FORECASTED HIGHS TO THE FAR RIGHT:
CLL (COLLEGE STATION) : 94 (1987) || 91
IAH (CITY OF HOUSTON) : 95 (1987) || 92
GLS (CITY OF GALVESTON):87 (1987) || 84
PREV DISCUSSION... /ISSUED 1038 AM CDT MON APR 28 2014/
UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
DISCUSSION...
PRECIP HAS COME TO AN END ACROSS MOST OF THE AREA THIS MORNING AS
DRIER AIR WORKS ITS WAY IN FROM THE WEST. HRRR SHOWS A CELL OR TWO
TRYING TO DEVELOP IN CHAMBERS COUNTY AS THE DRY LINE STALLS NEAR
THE COAST THIS AFTERNOON. THE TORNADO WATCH FOR THE AREA WILL BE
ALLOWED TO CONTINUE UNTIL 17Z.
BEHIND THE DRY LINE LIGHT NORTHWEST WINDS... LITTLE CLOUD COVER
AND DRY AIR WILL HELP THE AREA TO QUICKLY HEAT UP. CURRENT AMDAR
SOUNDING FOR HOUSTON SUPPORTS TEMPERATURES IN THE LOWER 90S. MOST
OF THE AREA IS ALREADY AT OR SLIGHTLY ABOVE 80. 90 DEGREES LOOKS
POSSIBLE FOR MOST SITES ACROSS THE AREA (MINUS NORTHEAST COUNTIES
AND AT THE COAST). NUDGED MAX TEMPERATURE GRID UP SLIGHTLY FOR
THIS AFTERNOON. ALSO TRIMMED POPS BACK AS THE CHANCE FOR
CONVECTION APPEARS TO BE COMING TO AN END. NO OTHER CHANGES TO
GRIDS AT THIS TIME. 23
PREV DISCUSSION... /ISSUED 421 AM CDT MON APR 28 2014/
DISCUSSION...
BKN LINE OF TSTMS HAS DEVELOPED SEVERAL MILES AHEAD OF THE SFC
TROF EXTENDING FROM NORTHEAST TEXAS AND INTO NORTHERN PARTS OF SE
TX. NO REPORTS OF SEVERE WX IN OUR CWA JUST YET BUT WOULD BE
SURPRISED IF NO HAIL IS EVENTUALLY REPORTED FROM HOUSTON COUNTY W/
THOSE STORMS. THINK MAJORITY OF THESE WILL REMAIN ELEVATED SO
HAIL WILL BE PRIMARY THREAT. HRRR MODEL HAS BEEN DOING A GOOD JOB
IN THE PAST 24 HOURS AND HAS CONTINUED DOING WELL WITH CURRENT
TRENDS. IT SHOWS THIS PRECIPITATION MAKING ITS WAY SEWD TOWARD THE
UPPER TX COAST IN THE NEXT 6 HOURS SO HAVE BUMPED POPS UP ACROSS A
GOOD PART OF THE AREA. SFC TROF WILL MAKE IT ALMOST TO THE COAST
BY LATE MORNING ENDING PRECIP CHANCES AND BRINGING A DRY AIRMASS
INTO MOST OF THE AREA. THIS DRY AIRMASS AND SUNSHINE SHOULD ALLOW
FOR A RAPID WARM UP ACROSS THE AREA THIS AFTN.
SFC TROF MOVES BACK NORTH LATE TONIGHT AND BECOME OVERTAKEN BY THE
PRIMARY COLD FRONT THAT WILL PUSH ACROSS THE AREA DURING THE DAY
TUE. CURRENT GUIDANCE COMING IN A TOUCH COOLER THAN EARLIER FCSTS
SO NUDGED HIGHS/LOWS DOWN A BIT FOR THE NEXT SEVERAL DAYS.
THRU LATE WEEK WE SHOULD STILL BE IN A WSW FLOW ALOFT UNDER BROAD
UPPER TROF SITUATED ACROSS CNTL PARTS OF THE COUNTRY. MAY SEE
PERIODS OF HIGH CLOUDINESS BUT MEAGER LLVL MOISTURE LEVELS SHOULD
KEEP THINGS MOSTLY DRY. SHOULD TRANSITION TO A DRY NW FLOW LATE IN
THE WEEK AND EARLY WEEKEND AS UPPER TROF MOVES EWD. OTHERWISE...LOOKS
QUITE DRY THRU THE 1ST WEEK OF MAY. 47
MARINE...
WILL EXTEND THE CURRENT ADVISORIES OVER THE COASTAL WATERS/CAUTION
FLAGS ON THE BAYS INTO THE MID MORNING HRS BASED ON CURRENT TRENDS.
GRADIENT STILL EXPECTED TO WEAKEN BY THE AFTN WITH THE APPROACH OF
THE PACIFIC FRONT FROM THE WEST. AS THIS BOUNDARY STALLS ALONG THE
COASTLINE...WINDS SHOULD REMAIN OUT OF THE SW/S THROUGH THE DAY/TO-
NIGHT. THE MAIN PUSH OF STRONG NORTH WINDS STILL FCST FOR TUE AFTN
WITH THE CANADIAN COLD FRONT. BEHIND THIS FRONT...CAUTION/ADVISORY
FLAGS WILL BE LIKELY FROM TUE NIGHT INTO WEDS NIGHT. THIS OFFSHORE
FLOW COULD EXTEND THROUGH THE END OF THE WEEK. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 59 82 51 75 / 10 10 10 0 0
HOUSTON (IAH) 92 62 86 55 78 / 20 10 10 0 0
GALVESTON (GLS) 84 71 84 62 77 / 20 10 20 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 2 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT MON APR 28 2014
.SHORT TERM...(TONIGHT AND TUESDAY)
ISSUED AT 322 PM CDT MON APR 28 2014
WATCHING THE FRONTAL STRUCTURE TO THE SOUTH CLOSELY AND
INSTABILITY TO SEE IF CHANGES IN SEVERE WEATHER FORECASTS NEED TO
BE CHANGED...AND TRYING TO BUILD IN BETTER TIMING OVERNIGHT FOR
NEXT WAVE OF RAIN. WINDS STILL STRONG...BUT THOSE SHOULD BE
DECREASING AFTER MIDNIGHT.
GOES WATER VAPOR IMAGERY SHOWING THE MAIN LONG WAVE ANCHORED NEAR
CENTRAL NEB WITH A NUMBER OF SHORTWAVE TROUGHS WITHIN THE LARGE
TROUGH AREA MOVING NORTH THROUGH IA/MO. IT APPEARS ONE SMALLER CURL
CAN BE SEEN IN NERN MO HEADING NORTH. THE AREA HAS BEEN UNDER
300-500MB QG CONVERGENCE LIFT AHEAD OF THIS BROAD TROUGH SPOKE
ROTATING NORTHWARD...WITH ISENTROPIC LIFT IN THE LOW-LEVELS NORTH
OF THE WARM FRONT...AND THE RAIN TODAY NOW LIFTING NORTH. THE
WARM FRONT CONTINUES TO HOLD NEARLY IN PLACE SOUTH OF I-80 AT 19Z.
MEANWHILE THE COLD FRONT FROM OMAHA TO CENTRAL MO WAS CLEAR ON
VISIBLE IMAGERY AND CONVECTING NOW...AND OVER THE PAST HOURS THE
OCCLUSION AND TRIPLE POINT ARE RIPPING EAST...NOW NEAR KDSM. THE
STORMS ON THIS OCCLUSION AND COLD FRONT WILL ROTATE NORTHWARD
TONIGHT INTO THE FORECAST AREA. 12Z RAOB PRECIPITABLE WATER VALUES
ARE NOT AS HIGH AS THE MORNING MODEL INITIALIZATIONS...WITH THE
28.12Z GFS/NAM SHOWING A 1-1.25 INCH PLUME FROM NRN IL INTO SERN
MN. KMPX WAS ONLY 0.62 AT 12Z FROM THE RAOB. 1500 FT WINDS OF AREA
88D VAD WINDS ARE STILL IN THE 40-50KT RANGE FROM KMKX-
KMPX...EXPLAINING THE CONTINUED WIND GUSTS IN THE 30S MPH.
AS THE LATER AFTERNOON PROGRESSES...THE COLD FRONT WILL CONTINUE
THE OCCLUSION PROGRESSES SEWRD TOWARD IL. BY EVENING THE TRIPLE
POINT SHOULD BE WELL INTO IL WITH A BAND OF TSRA ALONG AND NORTH
OF THE OCCLUSION HEADING NORTH TOWARD THE AREA. THE OCCLUSION
BOUNDARY STAYS NEAR I-80 IN THE LATEST HRRR RUNS...WITH THE
ELEVATED TSRA AND PRECIPITATION BAND ROTATING INTO MN/WI. THE
MOST UNSTABLE CAPE ANALYSIS SHOWS 250 J/KG IN THE SOUTHERN
FORECAST AREA AT 20Z...WITH ABOUT 500 J/KG APPROACHING THE
SOUTHERN FORECAST AREA. AS WITH DAYS PAST...AS THIS TSRA BAND
APPROACHES NERN IA AND SWRN WI AFTER 5 PM...CONVECTIVE ACTIVITY
IS EXPECTED TO DEGRADE. SOME SMALL HAIL IS POSSIBLE FROM THE
STORMS IN THE SOUTHERN FORECAST AREA...BUT THEN A TRANSITION TO A
MORE STRATIFORM RAIN REGION WILL OCCUR.
THERE IS EXCELLENT AGREEMENT ON THE MODEL GUIDANCE ON THE BAND
ROTATING NORTH THROUGH THE AREA OVERNIGHT. HAVE FORECAST AMOUNTS
OF LESS THAN ONE-HALF OF AN INCH. WITH MODELS TOO HIGH ON
PRECIPITABLE WATER...HAVE DISCOUNTED HEAVIER RAINFALL TOTALS SUCH
AS THE 28.12Z. THE BAND WILL ROTATE INTO THE NORTHERN FORECAST
AREA TUESDAY MORNING AND SLOW ITS PROGRESS AS THE SURFACE LOW
SHIFTS TOWARD ROCKFORD IL. THIS WILL PROVIDE A QUICK WARM UP TO
THE BOUNDARY LAYER AND SOME INSTABILITY ACROSS SOUTHWEST WI FOR A
TIME TUESDAY. HAVE ADDED SOME THUNDER THERE BUT DO NOT EXPECT MORE
THAN PEA SIZED HAIL WITH 250 J/KG OF CAPE OR SO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 322 PM MON APR 28 2014
TUESDAY NIGHT THROUGH THURSDAY NIGHT
THE AREA WILL BE RIGHT UNDER THE OCCLUDED DEEP LOW WITH SPOKES OF
ENERGY CONTINUING TO ROTATE THROUGH THE AREA. THE MODEL GUIDANCE
AGREES ON THE BIG PICTURE BUT THE DETAILS OF TIMING ON RAIN
CHANCES ARE ALL OVER THE PLACE AMONG ALL THE AVAILABLE MODELS.
HAVE KEPT THIS PERIOD SHOWERY WITH MUCH LIGHTER WINDS THAN WE HAVE
SEEN. FAIRLY SATURATED CONDITIONS AND SHORTWAVES THAT WILL BE
ROTATING THROUGH THE LONG WAVE WILL BRING MORE ORGANIZED SHOWER
AREAS I AM SURE. AT THIS POINT...RAISED RAIN CHANCES THROUGH THIS
PERIOD TO AT LEAST 60 PERCENT WITH MORE DETAIL TO BE ADDED AS WE
GET CLOSER TO THOSE DAYS AND CAN IDENTIFY WHERE TO IMPROVE THE
FORECAST. COOL AND CLOUDY WITH LIGHT RAINFALL /LESS THAN ONE
TENTH PER 12 HOURS/ FOR MOST EVERYWHERE.
FRIDAY THROUGH MONDAY
A BELOW NORMAL TEMPERATURE PERIOD. LONG WAVE TROUGH AND SHORTWAVE
ACTIVITY SPOKING AROUND THE LOW WILL MAKE FOR DETAILS IN THIS
PERIOD DIFFICULT. BY FRIDAY IT WOULD APPEAR THE MODEL CONSENSUS
SUGGEST THE AREA INTO NORTHWEST FLOW WHICH CAUSES ITS OWN ISSUES
FOR TIMING OF SHOWERS WITH SHORTWAVE TROUGHS. HEIGHTS RISE MORE
OVER THE GREAT LAKES ON FRIDAY NIGHT AND SATURDAY AS ENERGY
CRASHES ONTO THE WEST COAST. THIS ENERGY THEN EJECTS INTO THE
PLAINS BY LATER SATURDAY WITH CYCLOGENESIS AND SOUTHERLY RETURN
FLOW ACTIVATING ON THE FRONT TO THE SOUTHWEST. FOR A 150 HOUR
FORECAST...THERE IS PRETTY GOOD AGREEMENT WITH THE LATEST TWO RUNS
OF THE ECMWF/GFS MODELS THAT SHOWERS/RAIN WILL SPREAD ACROSS THE
REGION SUNDAY WITH THE NORMAL WARM FRONTAL LIFT SIGNALS OF
ISENTROPIC LIFT...MOISTURE TRANSPORT CONVERGENCE. WHILE PLACEMENT
IS VARIED...THE GENERAL AGREEMENT ADDS TO CONFIDENCE. BOTTOM LINE
IS SATURDAY LOOKS LIKE THE DRIER DAY STILL BUT CONFIDENCE IS
SOMEWHAT LOW WITH NORTHWEST FLOW VERY DIFFICULT TO FORECAST 5 DAYS
OUT. TEMPERATURES DONT LOOK TO REBOUND MUCH UNTIL SATURDAY...BUT
CLOUDS MAKE ALL THE DIFFERENCE THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 600 PM CDT MON APR 28 2014
CLOSED...VERTICALLY STACKED LOW WILL BE THE WEATHER MAKER OVER THE
NEXT FEW DAYS. THIS WILL KEEP KRST/KLSE UNDER A PROLONGED PERIOD OF
MVFR/IFR CIGS...WITH BOUTS OF MVFR VSBYS DURING -SHRA/RA.
WINDS WILL STAY STRONG TONIGHT...BUT AS THE LOW INCHES NORTHWARD
TUE...EXPECT SOME SLACKENING IN THE PRESSURE GRADIENT...AND A
REDUCTION IN WIND SPEEDS. DIRECTION WILL BECOME MORE NORTHERLY
TUE...THEN SHIFTING NORTHWEST LATE TUE NIGHT. LLWS REMAINS A CONCERN
AT KLSE WITH AROUND 50 KTS AT 2 KFT. WILL CONTINUE A MENTION IN
FORECAST INTO THE OVERNIGHT HOURS.
&&
.HYDROLOGY...
ISSUED AT 322 PM CDT MON APR 28 2014
AFTER RECEIVING LESS RAIN OVERNIGHT THAN ORIGINALLY THOUGHT...THE RIVER
SITUATION SEEMS LIKE IT WILL BEHAVE FOR THIS STORM. WE ARE EXPECTING
ABOUT 0.50 TO 0.75 INCHES OF RAIN TONIGHT AND TUESDAY FOR MOST AREAS
WHICH WILL MEAN BANKFULL RIVER RISES FOR MOST RIVERS...AND A LOW FLOODING
THREAT. THE KICKAPOO MAY BE THE CLOSEST RIVER TO FLOODING.
MAYBE THE MAIN STORY IS THE MISSISSIPPI RIVER THAT WILL SWALLOW
ALL THE INCOMING TRIBUTARY WATER AND CONTINUE TO RISE ALL NEXT
WEEK. FROM WINONA MN SOUTH...IT APPEARS THE MISSISSIPPI RIVER WILL
BE APPROACHING MINOR FLOOD LEVELS BY LATER THIS WEEK...WITH FLOODING
LIKELY FURTHER NORTH. THE FLOOD WATCH HAS BEEN ISSUED FOR THE
WINONA AND SOUTH FLOODING THREAT.
AFTER TONIGHT...RAINFALL AMOUNTS WILL TURN MORE SHOWERY AS THE
GULF MOISTURE PLUME IS SHUNTED EAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
WIZ041-053-054-061.
MN...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
MNZ088-096.
IA...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
IAZ011-030.
&&
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
AVIATION.....RIECK
HYDROLOGY....BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
323 PM CDT MON APR 28 2014
.SHORT TERM...(TONIGHT AND TUESDAY)
ISSUED AT 322 PM CDT MON APR 28 2014
WATCHING THE FRONTAL STRUCTURE TO THE SOUTH CLOSELY AND
INSTABILITY TO SEE IF CHANGES IN SEVERE WEATHER FORECASTS NEED TO
BE CHANGED...AND TRYING TO BUILD IN BETTER TIMING OVERNIGHT FOR
NEXT WAVE OF RAIN. WINDS STILL STRONG...BUT THOSE SHOULD BE
DECREASING AFTER MIDNIGHT.
GOES WATER VAPOR IMAGERY SHOWING THE MAIN LONG WAVE ANCHORED NEAR
CENTRAL NEB WITH A NUMBER OF SHORTWAVE TROUGHS WITHIN THE LARGE
TROUGH AREA MOVING NORTH THROUGH IA/MO. IT APPEARS ONE SMALLER CURL
CAN BE SEEN IN NERN MO HEADING NORTH. THE AREA HAS BEEN UNDER
300-500MB QG CONVERGENCE LIFT AHEAD OF THIS BROAD TROUGH SPOKE
ROTATING NORTHWARD...WITH ISENTROPIC LIFT IN THE LOW-LEVELS NORTH
OF THE WARM FRONT...AND THE RAIN TODAY NOW LIFTING NORTH. THE
WARM FRONT CONTINUES TO HOLD NEARLY IN PLACE SOUTH OF I-80 AT 19Z.
MEANWHILE THE COLD FRONT FROM OMAHA TO CENTRAL MO WAS CLEAR ON
VISIBLE IMAGERY AND CONVECTING NOW...AND OVER THE PAST HOURS THE
OCCLUSION AND TRIPLE POINT ARE RIPPING EAST...NOW NEAR KDSM. THE
STORMS ON THIS OCCLUSION AND COLD FRONT WILL ROTATE NORTHWARD
TONIGHT INTO THE FORECAST AREA. 12Z RAOB PRECIPITABLE WATER VALUES
ARE NOT AS HIGH AS THE MORNING MODEL INITIALIZATIONS...WITH THE
28.12Z GFS/NAM SHOWING A 1-1.25 INCH PLUME FROM NRN IL INTO SERN
MN. KMPX WAS ONLY 0.62 AT 12Z FROM THE RAOB. 1500 FT WINDS OF AREA
88D VAD WINDS ARE STILL IN THE 40-50KT RANGE FROM KMKX-
KMPX...EXPLAINING THE CONTINUED WIND GUSTS IN THE 30S MPH.
AS THE LATER AFTERNOON PROGRESSES...THE COLD FRONT WILL CONTINUE
THE OCCLUSION PROGRESSES SEWRD TOWARD IL. BY EVENING THE TRIPLE
POINT SHOULD BE WELL INTO IL WITH A BAND OF TSRA ALONG AND NORTH
OF THE OCCLUSION HEADING NORTH TOWARD THE AREA. THE OCCLUSION
BOUNDARY STAYS NEAR I-80 IN THE LATEST HRRR RUNS...WITH THE
ELEVATED TSRA AND PRECIPITATION BAND ROTATING INTO MN/WI. THE
MOST UNSTABLE CAPE ANALYSIS SHOWS 250 J/KG IN THE SOUTHERN
FORECAST AREA AT 20Z...WITH ABOUT 500 J/KG APPROACHING THE
SOUTHERN FORECAST AREA. AS WITH DAYS PAST...AS THIS TSRA BAND
APPROACHES NERN IA AND SWRN WI AFTER 5 PM...CONVECTIVE ACTIVITY
IS EXPECTED TO DEGRADE. SOME SMALL HAIL IS POSSIBLE FROM THE
STORMS IN THE SOUTHERN FORECAST AREA...BUT THEN A TRANSITION TO A
MORE STRATIFORM RAIN REGION WILL OCCUR.
THERE IS EXCELLENT AGREEMENT ON THE MODEL GUIDANCE ON THE BAND
ROTATING NORTH THROUGH THE AREA OVERNIGHT. HAVE FORECAST AMOUNTS
OF LESS THAN ONE-HALF OF AN INCH. WITH MODELS TOO HIGH ON
PRECIPITABLE WATER...HAVE DISCOUNTED HEAVIER RAINFALL TOTALS SUCH
AS THE 28.12Z. THE BAND WILL ROTATE INTO THE NORTHERN FORECAST
AREA TUESDAY MORNING AND SLOW ITS PROGRESS AS THE SURFACE LOW
SHIFTS TOWARD ROCKFORD IL. THIS WILL PROVIDE A QUICK WARM UP TO
THE BOUNDARY LAYER AND SOME INSTABILITY ACROSS SOUTHWEST WI FOR A
TIME TUESDAY. HAVE ADDED SOME THUNDER THERE BUT DO NOT EXPECT MORE
THAN PEA SIZED HAIL WITH 250 J/KG OF CAPE OR SO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 322 PM MON APR 28 2014
TUESDAY NIGHT THROUGH THURSDAY NIGHT
THE AREA WILL BE RIGHT UNDER THE OCCLUDED DEEP LOW WITH SPOKES OF
ENERGY CONTINUING TO ROTATE THROUGH THE AREA. THE MODEL GUIDANCE
AGREES ON THE BIG PICTURE BUT THE DETAILS OF TIMING ON RAIN
CHANCES ARE ALL OVER THE PLACE AMONG ALL THE AVAILABLE MODELS.
HAVE KEPT THIS PERIOD SHOWERY WITH MUCH LIGHTER WINDS THAN WE HAVE
SEEN. FAIRLY SATURATED CONDITIONS AND SHORTWAVES THAT WILL BE
ROTATING THROUGH THE LONG WAVE WILL BRING MORE ORGANIZED SHOWER
AREAS I AM SURE. AT THIS POINT...RAISED RAIN CHANCES THROUGH THIS
PERIOD TO AT LEAST 60 PERCENT WITH MORE DETAIL TO BE ADDED AS WE
GET CLOSER TO THOSE DAYS AND CAN IDENTIFY WHERE TO IMPROVE THE
FORECAST. COOL AND CLOUDY WITH LIGHT RAINFALL /LESS THAN ONE
TENTH PER 12 HOURS/ FOR MOST EVERYWHERE.
FRIDAY THROUGH MONDAY
A BELOW NORMAL TEMPERATURE PERIOD. LONG WAVE TROUGH AND SHORTWAVE
ACTIVITY SPOKING AROUND THE LOW WILL MAKE FOR DETAILS IN THIS
PERIOD DIFFICULT. BY FRIDAY IT WOULD APPEAR THE MODEL CONSENSUS
SUGGEST THE AREA INTO NORTHWEST FLOW WHICH CAUSES ITS OWN ISSUES
FOR TIMING OF SHOWERS WITH SHORTWAVE TROUGHS. HEIGHTS RISE MORE
OVER THE GREAT LAKES ON FRIDAY NIGHT AND SATURDAY AS ENERGY
CRASHES ONTO THE WEST COAST. THIS ENERGY THEN EJECTS INTO THE
PLAINS BY LATER SATURDAY WITH CYCLOGENESIS AND SOUTHERLY RETURN
FLOW ACTIVATING ON THE FRONT TO THE SOUTHWEST. FOR A 150 HOUR
FORECAST...THERE IS PRETTY GOOD AGREEMENT WITH THE LATEST TWO RUNS
OF THE ECMWF/GFS MODELS THAT SHOWERS/RAIN WILL SPREAD ACROSS THE
REGION SUNDAY WITH THE NORMAL WARM FRONTAL LIFT SIGNALS OF
ISENTROPIC LIFT...MOISTURE TRANSPORT CONVERGENCE. WHILE PLACEMENT
IS VARIED...THE GENERAL AGREEMENT ADDS TO CONFIDENCE. BOTTOM LINE
IS SATURDAY LOOKS LIKE THE DRIER DAY STILL BUT CONFIDENCE IS
SOMEWHAT LOW WITH NORTHWEST FLOW VERY DIFFICULT TO FORECAST 5 DAYS
OUT. TEMPERATURES DONT LOOK TO REBOUND MUCH UNTIL SATURDAY...BUT
CLOUDS MAKE ALL THE DIFFERENCE THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 1215 PM CDT MON APR 28 2014
AN EXTENDED PERIOD OF MVFR/IFR CIGS SETTING UP FOR THE TAF SITES.
THIS AS A LARGE/COLD/MOIST SFC TO MID LEVEL LOW OVER THE CENTRAL
PLAINS DRIFTS SLOWLY NORTHEAST INTO THE UPPER MIDWEST. MAINLY VFR
VSBYS EXPECTED AS BRISK...BUT DRIER...EASTERLY BECOMING NORTHEAST
AND NORTH SFC-925MB FLOW CONTINUES OVER SOUTHEAST MN/WESTERN WI THRU
TONIGHT/TUE. SOME MVFR/LCL IFR VSBYS EXPECTED IN BANDS OF HEAVIER
RAIN AS THEY ROTATE NORTH AND NORTHWEST ACROSS THE AREA. ONE OF
THESE TO IMPACT THE TAF SITES INTO THE EARLY AFTERNOON HOURS
TODAY...WITH ANOTHER EXPECTED TO LIFT NORTH ACROSS THE TAF SITES
DURING THE LATER EVENING AND OVERNIGHT HOURS. GENERALLY LIGHTER
PRECIP EXPECTED TUE WITH MAINLY VFR VSBYS.
TIGHT PRESSURE GRADIENT AND BRISK/GUSTY EAST WINDS WILL PERSIST
ACROSS THE TAF SITS THIS AFTERNOON/EVENING. AS THE SFC LOW MOVES
INTO EASTERN IA/NORTHERN IL LATER TONIGHT/TUE...PRESSURE GRADIENT
OVER THE AREA WILL RELAX WITH WINDS STILL BRISK BUT MORE IN THE 10-
20KT RANGE AND BECOMING NORTHEAST TO NORTH.
&&
.HYDROLOGY...
ISSUED AT 322 PM CDT MON APR 28 2014
AFTER RECEIVING LESS RAIN OVERNIGHT THAN ORIGINALLY THOUGHT...THE RIVER
SITUATION SEEMS LIKE IT WILL BEHAVE FOR THIS STORM. WE ARE EXPECTING
ABOUT 0.50 TO 0.75 INCHES OF RAIN TONIGHT AND TUESDAY FOR MOST AREAS
WHICH WILL MEAN BANKFULL RIVER RISES FOR MOST RIVERS...AND A LOW FLOODING
THREAT. THE KICKAPOO MAY BE THE CLOSEST RIVER TO FLOODING.
MAYBE THE MAIN STORY IS THE MISSISSIPPI RIVER THAT WILL SWALLOW
ALL THE INCOMING TRIBUTARY WATER AND CONTINUE TO RISE ALL NEXT
WEEK. FROM WINONA MN SOUTH...IT APPEARS THE MISSISSIPPI RIVER WILL
BE APPROACHING MINOR FLOOD LEVELS BY LATER THIS WEEK...WITH FLOODING
LIKELY FURTHER NORTH. THE FLOOD WATCH HAS BEEN ISSUED FOR THE
WINONA AND SOUTH FLOODING THREAT.
AFTER TONIGHT...RAINFALL AMOUNTS WILL TURN MORE SHOWERY AS THE
GULF MOISTURE PLUME IS SHUNTED EAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
WIZ041-053-054-061.
MN...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
MNZ088-096.
IA...FLOOD WATCH FROM LATE SATURDAY NIGHT THROUGH TUESDAY EVENING FOR
IAZ011-030.
&&
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...SWERMAN
HYDROLOGY...BAUMGARDT
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 240 PM CDT MON APR 28 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LARGE AND
STUBBORN UPPER LOW SPINNING OVER THE CENTRAL GREAT PLAINS AND A WARM
FRONT POSITIONED OVER CENTRAL IOWA TO CENTRAL INDIANA. WARM
CONVEYOR BELT IS RISING OVER THE 850MB FRONT LOCATED OVER SOUTHERN
WISCONSIN AND ALONG WITH MID-LEVEL FGEN...IS HELPING TO PRODUCE AN
ARCING BAND OF RAIN FROM CENTRAL MINNESOTA TO CENTRAL LOWER
MICHIGAN. THIS BAND HAS BEEN SLOWING LIFTING NORTH TODAY WITH
ASSISTANCE FROM A SHORTWAVE LOBE OVER IOWA...WHICH IS ROTATING
AROUND THE PARENT CYCLONE. THIS BAND WILL CONTINUE TO LIFT NORTH
AND COULD REACH THE U.P BORDER BY THE END OF THE AFTERNOON. FAR
NORTHERN WISCONSIN HAS BEEN DRY SO FAR TODAY WHERE TEMPS HAVE RISEN
INTO THE LOWER 50S...BUT THIS SHOULD END SOON. PRECIP TRENDS AND
AMOUNTS REMAIN THE MAIN FORECAST CONCERNS.
TONIGHT...SLOW MOVING UPPER LOW OVER THE CENTRAL GREAT PLAINS WILL
CONTINUE ITS SLOW JAUNT TO THE EAST. EAST OF THIS UPPER LOW...850MB
WARM FRONT WILL LIFT NORTH INTO CENTRAL AND NORTHEAST WISCONSIN
WHILE THE LEFT FRONT QUAD OF A JET STREAK WILL PUSH NORTHWARD ACROSS
WISCONSIN. PLENTY OF MID-LEVEL FGEN AND UPPER DIVERGENCE WITHIN THE
PWAT MAXIMUM BAND TO SUPPORT THE ARCING BAND OF RAIN OVER THE
WESTERN GREAT LAKES TO LIFT SLOWLY NORTHWARD THROUGH THE NIGHT. A
HALF INCH TO AN INCH OF RAIN IS POSSIBLE ACROSS CENTRAL AND
EAST-CENTRAL WISCONSIN THAT WILL LIKELY AGGRAVATE RIVER FLOODING.
AS THE PRECIP MOVES INTO NORTHERN WISCONSIN TONIGHT AND THE BOUNDARY
LAYER COOLS...PROGGED SOUNDINGS LOOK COLD ENOUGH FOR WET SNOW FLAKES
TO MIX IN WITH THE RAIN. PERHAPS COULD SEE A LITTLE COATING ON
GRASSY SURFACES BUT TEMPS ARE EXPECTED TO REMAIN ABOVE FREEZING SO
HARD TO SEE ANY ACCUMULATION ON ROADWAYS. WINDS WILL REMAIN GUSTY
AND ACTUALLY INCREASE LATE TONIGHT OVER THE FOX VALLEY AS THE
TRAJECTORIES TURN NORTHEAST AND FUNNEL DOWN THE BAY. WILL HAVE
GUSTS UP TO 40 MPH LATE. LOWS IN THE MID TO UPPER 30S.
TUESDAY...THE UPPER LOW WILL NOSE ITS WAY INTO THE SOUTHWESTERN GREAT
LAKES. OTHERWISE...LITTLE CHANGES SYNOPTICALLY. WILL HAVE A STRONG
SHORTWAVE ROTATE AROUND THE UPPER LOW INTO NORTHERN LAKE MICHIGAN
DURING THE AFTERNOON WHICH WILL PUSH A 850MB TROUGH INTO NORTHEAST
WISCONSIN. THIS MAY BRING BREAKS IN THE RAIN AND DIMINISHING WINDS
OVER EAST-CENTRAL AND NORTHEAST WISCONSIN DURING THE PM HOURS...BUT
EXPECT THE STEADY RAINS TO CONTINUE OVER NORTH-CENTRAL WISCONSIN
THROUGH THE DAY. SOME RAIN WILL STILL HAVE SOME SNOW MIXED IN
DURING THE MORNING HOURS. ANOTHER QUARTER TO A HALF INCH OF RAIN
APPEARS POSSIBLE. HIGHS RANGING FROM AROUND 40 NORTH TO NEAR 50S
SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 240 PM CDT MON APR 28 2014
PCPN TRENDS AND TEMPERATURES ARE THE MAIN FCST CONCERNS.
THE UPPER LEVEL LOW IS EXPECTED TO LINGER OVER THE WESTERN GREAT
LAKES THROUGH THURSDAY...THEN WEAKEN INTO AN OPEN WAVE AND SHIFT
EAST. THE MOST SIGNIFICANT BAND OF PCPN SHOULD ALREADY HAVE MOVED
THROUGH THE CWA (MONDAY AFTERNOON THROUGH TUESDAY)...BUT A HIGH
POP/LOW QPF SCENARIO IS LIKELY TO CONTINUE THROUGH THURSDAY.
MODELS ARE ALL OVER THE PLACE WITH REGARD TO THE VARIOUS S/W TROFS
ROTATING AROUND THE MAIN UPPER LOW...SO HAVE GONE WITH A MULTI-
MODEL BLEND...RESULTING IN BROADBRUSH LIKELY POPS FROM TUES NGT
THROUGH THURSDAY. PCPN SHOULD BE ALMOST ALL RAIN...BUT KEPT A MIX
IN OVER VILAS CO LATE WED NGT/EARLY THU.
THE UPPER AIR PATTERN IS EXPECTED TO GRADUALLY TRANSITION TO
ZONAL FLOW BY THE END OF THE WEEKEND/EARLY NEXT WEEK...WITH OCNL
S/W TROFS AND WEAK COLD FRONTS MOVING THROUGH. SMALL POPS ARE
WARRANTED DURING THIS PERIOD...BUT PCPN AMOUNTS SHOULD BE ON THE
LIGHT SIDE. THE AIR MASS WILL REMAIN COOL ENOUGH FOR A LIGHT MIX
OF RAIN AND SNOW SHOWERS OVER NORTHERN WI DURING SOME OF THE
NIGHTTIME PERIODS.
TEMPERATURES WILL REMAIN BLO NORMAL THROUGH THE PERIOD...WITH
HIGHS MAINLY IN THE UPPER 40S TO MIDDLE 50S...AND LOWS IN THE
30S AND LOWER 40S.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1200 PM CDT MON APR 28 2014
A LARGE UPPER LOW SYSTEM SLOWLY CHURNING ACROSS MID
SECTION OF THE COUNTRY THIS WEEK WILL CONTINUE TO LIFT BANDS OF
SHOWERS NORTH OVER THE STATE FOR MUCH OF THE WEEK. DRY AIR ON
EASTERLY WINDS WILL CONTINUE TO POUR INTO THE AREA TO KEEP CIGS
MAINLY AT VFR LEVELS FOR THE REST OF THIS AFTERNOON. AS SHOWERS
BECOME MORE WIDESPREAD FROM SOUTHWEST TO NORTHEAST...CIGS WILL
ALSO LOWER TO MVFR OR IFR LEVELS. A COMPACT PRESSURE GRADIENT
AHEAD OF THE LARGE SURFACE LOW OVER THE CENTRAL PLAINS WILL ENSURE
GUSTY WINDS AT THE SURFACE FOR A FEW DAYS.
&&
.HYDROLOGY...
ISSUED AT 240 PM CDT MON APR 28 2014
RAINFALL TOTALS OF 1 TO 2 INCHES CAN BE EXPECTED BY WEDNESDAY
AFTERNOON. THE HIGHEST TOTALS WILL BE ACROSS PORTIONS OF CENTRAL
WISCONSIN INTO THE FOX VALLEY REGION. THE RESULTING RUNOFF COULD
CAUSE SOME MINOR RIVER FLOODING...AS SEVERAL RIVERS STILL REMAIN
ABOVE BANKFULL. WILL CONTINUE TO MENTION THE RIVER FLOODING
THREAT IN A HYDROLOGIC OUTLOOK AND THE HAZARDOUS WEATHER OUTLOOK.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
HYDROLOGY......MPC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
502 PM MDT MON APR 28 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 247 PM MDT MON APR 28 2014
MAIN CONCERN THIS PERIOD WILL CONTINUE TO BE WINDS AS THEY WILL
REMAIN RATHER STRONG THOUGH WEDNESDAY...ESPECIALLY OVER THE
PLAINS. IN THE IMMEDIATE SHORT-TERM CURRENT ADVY/HI WIND HILITES
LOOK FINE OVER MOST OF THE PANHANDLE AND WILL KEEP UP INTO THIS
EVENING...HOWEVER WILL TRIM OUT DAWES AND BOX BUTTE COUNTIES AS
WINDS HAVE DROPPED OFF THERE.
UPPER LOW OVER NEB WILL DRIFT ONLY SLOWLY EASTWARD OR MEANDER
THROUGH WEDS WITH STRONG MID-LEVEL WINDS MIXING DOWN TO THE
SURFACE BOTH AFTERNOONS. BIG DILEMMA IS HOW MUCH. CLOUDS AND PCPN
WILL TEND TO LIMIT MIXING SOME. PROGGED 800MB WINDS FOR TUESDAY
ABOUT THE SAME AS TODAY WHERE MOST AREAS STAYED IN ADVISORY SPEEDS.
WILL NEED AT LEAST AN ADVISORY FOR THE PANHANDLE AGAIN TUESDAY AND
COULD FLIRT WITH HIGH WIND LEVELS DESPITE SLIGHTLY LESS GRADIENT
IF MORE MIXING OCCURS. WILL HOLD OFF ON NEW HILITES FOR NOW...
ALLOWING CURRENT ONES TO EXPIRE FIRST.
WRAP-AROUND PRECIPITATION WILL ALSO CONTINUE TONIGHT AND TUESDAY
THEN SHOULD TREND DOWN TUESDAY NIGHT AND WEDS AS THE UPPER LOW
DRIFTS FARTHER AWAY AND A SOMEWHAT DRIER NORTHERLY FLOW OCCURS
OVER THE AREA. SOME LIGHT SNOW ACCUMULATIONS POSSIBLE OVER THE
NORTHERN PANHANDLE TONIGHT THOUGH HIGHER AMOUNTS LOOK TO BE JUST A
BIT TO THE EAST. TEMPERATURES REMAINING COOL THROUGH WEDNESDAY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 247 PM MDT MON APR 28 2014
LATEST WATER VAPOR LOOP WAS SHOWING THE UPPER LEVEL RIDGE BUILDING
ACROSS THE PACIFIC NORTHWEST IN RESPONSE TO THE DIGGING UPPER
LEVEL TROF OFF THE GULF OF ALASKA. THIS SCENARIO WILL FAVOR RATHER
DRY AND COOL CONDITIONS ON THURSDAY. BEYOND THURSDAY...THE UPPER
LEVEL PATTERN BEGINS TO FLATTEN OUT SOME WHICH WILL FAVOR MORE UNSETTLED
CONDITIONS TOWARDS THE WEEKEND.
FRIDAY-SATURDAY:
THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH A WARM UP TAKING PLACE
THIS WEEKEND AS 700MB TEMPERATURE STANDARDIZED ANOMALIES APPROACH
TO 1 STANDARD DEVIATION. THIS SHOULD ALLOW FOR TEMPERATURES TO
CLIMB TO AROUND 70 ON SATURDAY. IT MAY BE A TAD COOLER ACROSS
NORTHEAST CORNER OF OUR FORECAST AREA CLOSER TO THE UPPER LEVEL
TROF PUSHING DOWN INTO THE NORTHERN PLAINS. A WEAK BOUNDARY IS
EXPECTED TO DIVE SOUTHEAST ACROSS THE AREA ON FRIDAY AND MAY BRING
A CHANCE OF SHOWERS MAINLY ACROSS AREAS EAST OF THE LARAMIE RANGE
FRIDAY MORNING. ELSEWHERE...THERE WILL BE SOME GOOD UPSLOPE
FLOW IN THE HIGHER ELEVATIONS WHICH WILL FAVOR SOME SCATTERED RAIN
SHOWERS ON FRIDAY. SATURDAY WE MAY SEE MORE OF A THREAT OF SOME
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG A BOUNDARY EXTENDING
FROM THE SOUTHERN PANHANDLE TO DOUGLAS. THIS AREA MAY ACTUALLY SEE
A FEW THUNDERSTORMS DURING THE AFTERNOON WITH CAPE VALUES REACHING
1000J/KG. WE WILL SEE HOW THINGS EVOLVE AS WE APPROACH THE WEEKEND
ESPECIALLY WITH REGARDS TO THE POSITION OF THE WAVES.
SUNDAY-MONDAY:
THE MODELS DO SHOW SOME WEAK UPPER LEVEL RIDGING TAKING PLACE
WHICH WILL KEEP OUR TEMPERATURES ON THE MILD SIDE. THE SURFACE LEE
TROF MAY ALSO BECOME ESTABLISHED WHICH MAY FAVOR BETTER MOISTURE
EAST OF THE LARAMIE RANGE. AS A RESULT...WE MAY SEE A CHANCE OF
THUNDERSTORMS EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON)
ISSUED AT 458 PM MDT MON APR 28 2014
STRATUS LIKELY TO MOVE INTO THE KCDR AND KAIA AERODROMES THIS
EVENING AND PERSIST INTO TUESDAY MORNING. LATEST HRRR FORECAST
DOES SHOW SOME TEMPO IFR CONDITIONS UP THAT WAY FOR A TIME
TONIGHT. BIG ISSUE IS WIND...WHICH WILL DIE OFF SLIGHTLY
TONIGHT...BUT THEN PICK UP AROUND THE 14Z TIME FRAME TUESDAY. WIND
GUSTS OR 45 TO 50KTS LIKELY FOR THE SOUTHERN PANHANDLE AIRPORTS
ONCE AGAIN TUESDAY.
&&
.FIRE WEATHER...
ISSUED AT 247 PM MDT MON APR 28 2014
NO CONCERNS ANTICIPATED THROUGH THE WEEK WITH TEMPERATURES
EXPECTED TO BE COOL TO MILD THROUGH THE MID PART OF THE WEEK THEN
WARM SOME BY THE END OF THE WEEK. CONDITIONS WILL REMAIN NON-
CRITICAL OUTSIDE OF WINDS WHICH WILL REMAIN RATHER STRONG MAINLY
IN THE AFTERNOONS OVER THE PLAINS THROUGH WEDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR NEZ095-096.
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR NEZ019>021-054-
055.
&&
$$
SHORT TERM...RE
LONG TERM...REC
AVIATION...CLAYCOMB
FIRE WEATHER...RE