Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/13/14
AREA FORECAST DISCUSSION
NWS PUEBLO CO
706 PM MDT MON MAY 12 2014
.UPDATE...
ISSUED AT 704 PM MDT MON MAY 12 2014
MINOR UPDATE TO BRING IN CURRENT OBS AND RAISE POPS IN THE SAN
LUIS VALLEY AND SOUTHERN SANGRES. -PJC
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM MDT MON MAY 12 2014
...HEAVY SNOW CONTINUES FOR THE CONTINENTAL DIVIDE...WITH FREEZING
TEMPERATURES FOR THE SOUTHEAST PLAINS TONIGHT...
ENERGY DROPPING DOWN THE WEST SIDE OF THE UPPER TROF WILL KEEP SNOW
SHOWERS GOING ACROSS SOUTHERN AND WESTERN PORTIONS OF THE AREA.
LAPSE RATES ARE STEEP BENEATH THE UPPER TROF ALOFT..AND SNOW HAS
BEEN REALLY COMING DOWN IN WEB CAMS AT WOLF CREEK. VIS IS DOWN TO
1/4 MILE AS OF THIS LAST HOUR. ROADWAYS STILL LOOK CLEAR...BUT WITH
TEMPERATURES ALREADY IN THE 20S ACROSS THE HIGHER ELEVATIONS...IT
WOULD NOT TAKE MUCH MORE COOLING FOR SNOW TO BEGIN TO STICK.
NAM12...GFS...AND RAP ALL KEEP HEAVY SNOW CONTINUING THROUGH THE
OVERNIGHT HOURS...THOUGH MAJORITY WILL LIKELY FALL BEFORE MIDNIGHT.
FOR THAT REASON...UPGRADED THE WINTER WEATHER ADVISORIES FOR THE
HIGHER ELEVATIONS OF THE EASTERN SAN JUANS AND LA GARITAS TO A
WINTER STORM WARNING WITH AN EARLIER FORECAST PACKAGE UPDATE.
EASTERLY UPSLOPE FLOW INTO THE EASTERN SLOPES OF THESE RANGES WILL
ALSO LEAD TO FAIRLY HEALTHY SNOW AMOUNTS FOR THE WESTERN SIDE OF THE
SAN LUIS VALLEY. CDOT WEBCAM AT ANTONITO HAS SOME SNOW
FALLING...THOUGH MOST IS MELTING ON PAVEMENT SURFACES...AND WITH
TEMPERATURES STILL AROUND OR SLIGHTLY ABOVE FREEZING EXPECT THIS TO
CONTINUE. HAVE PUT UP A WINTER WEATHER ADVISORY FOR THE LOWER
ELEVATIONS OF THE EASTERN SAN JUANS AND LA GARITAS AS WELL AS THE
HIGHER AREAS OF THE SAWATCH RANGE. WARNING AREAS COULD PICK UP A
TOTAL OF 8 TO 16 INCHES...WITH 4 TO 8 INCHES FOR THE ADVISORY AREAS.
THE WESTERN SIDE OF THE SAN LUIS VALLEY COULD SEE ON THE ORDER OF
1 TO 4 INCHES...BUT WARM GROUND MAY LIMIT ACCUMULATIONS TO LESSER
AMOUNTS.
THE SANGRES AND WETS COULD ALSO PICK UP SOME ADDITIONAL
ACCUMULATIONS TONIGHT...WITH ANOTHER 1 TO 3 INCHES FOR THE LOWER
ELEVATIONS...AND 2 TO 5 INCHES FOR THE HIGHER PEAKS.
SNOW WILL WIND DOWN EARLY TOMORROW MORNING...SO HEADLINES WILL
EXPIRE AT 6 AM. MEANWHILE...SOUTHEAST PLAINS WILL SEE A WIDESPREAD
FREEZE TONIGHT...AND CURRENT FREEZE WARNING STILL LOOKS ON TRACK.
UPPER TROF AXIS WILL SHIFT EAST OF THE AREA ON TUESDAY...BUT WITH
LINGER MOISTURE AND INSTABILITY...EXPECT ANOTHER ROUND OF ISOLATED
TO SCATTERED SHOWERS ACROSS THE MOUNTAINS. TEMPERATURES WILL
REBOUND A FEW DEGREES OVER THOSE OF TODAY...BUT HIGHER MOUNTAINS
WILL STILL SEE PRECIPITATION IN THE FORM OF SNOW. ANY ACCUMULATIONS
SHOULD REMAIN LIGHT...WITH A SPOTTY 1-3 INCHES POSSIBLE. -KT
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 340 PM MDT MON MAY 12 2014
TUESDAY NIGHT THROUGH SATURDAY...LONG RANGE MODELS INDICATE THAT THE
UPPER SYSTEM WILL PARK OVER THE MIDWEST THROUGH MUCH OF THE WORK
WEEK...KEEPING COLORADO UNDER NW FLOW ALOFT. THIS FLOW IS A COOLER
ONE...SO THE WARM UP FOR THE FORECAST AREA IS EXPECTED TO BE SLOWER
UNTIL THE UPPER PATTERN SHIFTS. THE UPPER RIDGE TO THE WEST IS
FORECAST TO FINALLY FLATTEN AND SLIDE ACROSS THE STATE ON SAT. THIS
TRANSLATES TO ANOTHER THREAT OF FREEZING TEMPS FOR THE PLAINS TUE
NIGHT...THEN HIGH TEMPS ON WED IN THE 50S AND 60S. TEMPS GRADUALLY
WARM THU THROUGH SAT WITH MAX TEMPS IN THE 70S FOR THE PLAINS...AND
IN THE 60S FOR THE HIGH VALLEYS. EXTENDED MODELS ALSO HINT AT MORE
OF A SUMMERTIME PATTERN WHEN IT COMES TO CONVECTION...WITH AN
ISOLATED THREAT FOR SHOWERS AND STORMS OVER THE MTS EACH AFTN AND
EARLY EVE THROUGH SAT.
SUNDAY AND MONDAY...A LARGE UPPER TROUGH OF LOW PRESSURE MOVES
ONSHORE ACROSS THE WEST COAST LATE SAT...PRODUCING INCREASING SW
FLOW ALOFT FOR THE DESERT SW. LOOK FOR DRY AND VERY WARM CONDITIONS
FOR THE FORECAST AREA BOTH SUN AND MON...WITH MAX TEMPS IN THE 80S
FOR THE E PLAINS...AND IN THE 60S AND 70S FOR THE HIGH VALLEYS.
MOORE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 340 PM MDT MON MAY 12 2014
VFR CIGS EXPECTED AT KCOS AND KPUB...THOUGH KCOS COULD
SEE A BRIEF DIP TO MVFR AS SHOWERS DROP DOWN OUT OF THE NORTH AND
CLIP BY THE TERMINAL. NORTH WINDS OFF THE PALMER DIVIDE SHOULD
PREVENT FOG FORMATION TOWARDS MORNING...THOUGH SOME MVFR STRATUS
WILL BE POSSIBLE AT TIMES TUESDAY MORNING. KALS WILL SEE THE BEST
CHANCE FOR SNOW SHOWERS...THOUGH ACCUMULATIONS AT THE TERMINAL
SHOULD REMAIN AROUND AN INCH OR LESS...MAINLY ON GRASSY SURFACES.
VFR CONDITIONS ARE EXPECTED ALL THREE TERMINALS TUESDAY AFTERNOON.
-KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 8 AM MDT TUESDAY FOR
COZ083>089-093>099.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT TUESDAY FOR COZ060-064-
067.
WINTER STORM WARNING UNTIL 6 AM MDT TUESDAY FOR COZ066-068.
&&
$$
UPDATE...PJC
SHORT TERM...KT
LONG TERM...MOORE
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
338 PM MDT SUN MAY 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM MDT SUN MAY 11 2014
...SIGNIFICANT SNOWS EXPECTED TO CONTINUE ACROSS THE CENTRAL
MOUNTAINS AND PIKES PEAK REGION...
UPPER LOW NEARING THE FOUR CORNERS REGION THIS AFTERNOON WILL BE
LIFTING NORTHEASTWARD OVERNIGHT INTO NORTHEAST CO BY 18Z MONDAY.
SURFACE FRONT HAS PUSHED THROUGH ALL OF THE SOUTHEAST PLAINS AS OF
21Z. SNOWFALL AMOUNTS SO FAR HAVE BEEN HIGHLY DETERMINED BY THE
SNOW LEVELS AND WARM GROUND. PIKES PEAK REGION HAS ALREADY DROPPED
INTO THE LOWER TO MID 30S...WITH UPPER 20S ACROSS TELLER COUNTY.
THIS HAS BEEN THE AREA WHICH HAS RECEIVED THE MOST SNOW...THOUGH A
LOOK AT WEB CAMS ACROSS THE AREA SHOWS THAT WARM GROUND HAS
MITIGATED ACCUMULATIONS SOME. MAINLY GRASSY SURFACES HAVE
ACCUMULATION...BUT OCCASIONALLY HAVE SEEN SOME SNOW ON THE PAVEMENT
DURING THE HEAVIER SNOW BURSTS. STILL WAITING FOR SNOW LEVELS TO
DROP ACROSS THE UPPER ARKANSAS RIVER VALLEY...WITH SALIDA AND BUENA
VISTA AIRPORTS STILL IN THE 40S AS OF 21Z. DOWN AROUND COLORADO
CITY AND RYE...TEMPERATURES ARE STILL IN THE UPPER 30S AND LOWER
40S...BUT TEMPERATURES HAVE BEEN DROPPING QUICKLY THIS LAST HOUR AND
SUSPECT RAIN/SNOW SWITCH OVER FOR THE UPPER ARKANSAS RIVER VALLEY OF
FREMONT AND CHAFFEE AND THE LOWER ELEVATION OF THE WET MOUNTAINS IS
NOT LONG OFF.
AS FOR HIGHLIGHTS...HAVE LEFT THEM AS IS. A LITTLE CONCERNED THAT
LATER SWITCH OVER TO SNOW ACROSS LOWER ELEVATIONS OF CHAFFEE COUNTY
MAY HURT SNOW TOTALS SOME...BUT BEST FORCING WILL CONTINUE TO TREK
ACROSS THIS AREA THROUGH THE EVENING...AND LATEST 18Z NAM IS NOW
HITTING THIS AREA WITH AROUND 4 INCHES OF SNOW THROUGH THE EVENING
HOURS. ONCE THE SWITCH OVER OCCURS...IT WILL NOT TAKE LONG FOR
ACCUMULATIONS TO START STACKING UP...THOUGH SUSPECT THE WARM GROUND
WILL MAKE FOR A WIDE RANGE OF ACCUMULATIONS WITH LOCATIONS LIKE
SALIDA COMING UP ON THE LOW END. ON THE FENCE WITH UPGRADING TO A
WINTER STORM WARNING FOR THE LOWER ELEVATIONS OF THE WET MOUNTAINS
AND THE NORTHERN SANGRE DE CRISTO MOUNTAINS. THERE COULD BE A FEW
AREAS THAT HIT AROUND 12 INCHES...BUT THE LATE TRANSITION OVER TO
SNOW WILL LARGELY KEEP AMOUNTS MORE IN THE ADVISORY RANGE.
AS FOR TIMING OF THE HEAVIER SNOWS...HEAVIEST SHOULD FALL NOW
THROUGH MIDNIGHT. AFTER MIDNIGHT...BEST FORCING SHIFTS NORTH OF THE
AREA...AND ALTHOUGH THERE WILL STILL BE SOME WRAP AROUND SNOWS
ACROSS THE CENTRAL MOUNTAINS/PIKES PEAK AREA...DOWNSLOPE NORTHERLY
WINDS OFF THE PALMER DIVIDE SHOULD OPEN UP THE PRECIPITATION MINIMUM
ACROSS SOUTHERN EL PASO AND NORTHERN PUEBLO COUNTIES. THIS COULD
OCCUR AS EARLY AS 10 PM. WINTER WEATHER ADVISORIES FOR SOUTHERN EL
PASO COUNTY MAY RUN A TAD TOO LONG...BUT WILL LET LATER SHIFTS
MONITOR TRENDS AND MAKE ANY NEEDED ADJUSTMENTS.
THE WET MOUNTAINS AND SOUTHERN I-25 CORRIDOR WILL SEE MORE
CONVECTIVE BURSTS OF RAIN/SNOW...WHICH SHOULD SWITCH OVER TO ALL
SNOW BY AROUND 6 PM. HOWEVER...MAJORITY OF THE HEAVIER SNOW MAY BE
DONE BY 6 AM...AND POSSIBLY EVEN SOONER IF LATEST HRRR IS CORRECT.
AS FOR THE SOUTHEAST PLAINS...HAVE EXTENDED THE FREEZE WARNING TO
INCLUDE CROWLEY COUNTY...AS AM GETTING A FEW HOURS OF SUBFREEZING
TEMPERATURES THERE. NOT MUCH SNOW IS EXPECTED...THOUGH SWITCH OVER
COULD OCCUR AROUND 6 PM FOR PUB...AROUND MIDNIGHT FOR LHX...AND EVEN
LATER FOR POINTS FARTHER EAST WHERE IT MAY STAY ALL RAIN...OR GO TO
A BRIEF RAIN/SNOW MIX TOWARDS MORNING BEFORE IT ENDS. GRASSY
SURFACES AROUND PUEBLO...WALSENBURG...TRINIDAD COULD SEE AN INCH OR
TWO AT ANY TIME...BUT WARM GROUND MAY MELT IT OFF QUICKLY.
ON MONDAY...ANOTHER TRAILING DISTURBANCE DROPS IN IN NORTHWEST FLOW
ALOFT...AND SENDS ANOTHER ROUND OF SNOW INTO THE MOUNTAIN
AREAS...PARTICULARLY ALONG THE CONTINENTAL DIVIDE. THIS CONTINUES
INTO MONDAY EVENING. ITS POSSIBLE THESE AREAS MAY NEED ANOTHER
HIGHLIGHT...MOST LIKELY AN ADVISORY...BUT SINCE THERE SEEMS TO BE A
DISTINCT BREAK BETWEEN THE TWO SYSTEMS...WILL LET LATER SHIFTS
DETERMINE WHAT IF ANY HIGHLIGHTS WILL BE NEEDED. SUSPECT THAT TO
SOME EXTENT...THE HIGHER SNOWFALL AMOUNTS IN THE GFS MAY BE A TAD
OVERDONE DUE TO SOME CONVECTIVE COMPONENT...AND HAVE GONE CLOSER TO
THE NAM FOR NOW. -KT
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 258 PM MDT SUN MAY 11 2014
SECONDARY UPPER LOW AND UPSLOPE FLOW WILL KEEP SOME SNOW GOING
OVER THE SAN JUANS/SANGRES MON EVENING...AND SOME ADDITIONAL LIGHT
ACCUMLATION IS POSSIBLE WITH BEST CHANCE OVER THE EASTERN SAN
JUANS. PRECIP THEN SLOWLY SHIFTS SOUTH OVERNIGHT AS UPPER TROUGH
MOVES EAST...WHICH WILL END MOST ACCUMULATING SNOW BY EARLY
TUESDAY MORNING. MANY AREAS WILL HAVE THE POTENTIAL FOR FREEZING
TEMPS ONCE AGAIN BY EARLY TUE MORNING...THOUGH AMOUNT OF MID LEVEL
CLOUDINESS MAY BE THE DETERMINING FACTOR ON HOW WIDESPREAD COLD
TEMPS BECOME. VERY GRADUAL WARMING AND DRYING TREND BEGINS
TUESDAY AFTERNOON...THOUGH SOME RESIDUAL MOISTURE/INSTABILITY
OVER THE MOUNTAINS MAY PRODUCE A FEW LIGHT SHOWERS TUE AFTERNOON.
NEUTRAL TO WEAK WARM ADVECTION...COMBINED WITH INCREASING MAY SUN
SHOULD BOOST MAX TEMPS SEVERAL DEGF VERSUS MONDAYS HIGHS...THOUGH
READINGS WILL STILL RUN WELL BELOW SEASONAL AVERAGES. ANOTHER THREAT
OF SOME PATCHY FROST TUE NIGHT/WED MORNING AS SKIES
CLEAR...ESPECIALLY EL PASO COUNTY/LOW LYING AREAS OF PUEBLO
COUNTY.
UPPER RIDGE THEN BUILDS OVER THE WESTERN U.S. FOR MID-WEEK...THEN
GRDUALLY FLATTENS NEXT WEEKEND. IN GENERAL...GRADUAL
WARMING/DRYING TREND IN STORE FOR THE AREA THROUGH THE
PERIOD...THOUGH A COUPLE WAVES EMBEDDED IN THE NW FLOW MAY
PRODUCE AT LEAST SOME ISOLATED -TSRA/-SHRA OVER THE EASTERN
MOUNTAINS AND PLAINS THU/FRI AS MODEST LOW LEVEL MOISTURE RETURNS
SLOWLY INTO THE HIGH PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 258 PM MDT SUN MAY 11 2014
IFR CONDITIONS EXPECTED TO CONTINUE AT KCOS...WITH THE EARLIEST
POTENTIAL FOR RETURN OF MVFR CONDITIONS BETWEEN 04Z AND 06Z.
SNOWFALL WILL MAINLY STAY CONFINED TO THE GRASSY SURFACES WHERE 1
TO 3 INCHES WILL BE POSSIBLE...BUT WARM GROUND MAY CAUSE SOME
MELTING BETWEEN HEAVIER SNOW BURSTS. KPUB WILL REMAIN
-SHRA...UNTIL AROUND 00Z WHEN A -SHRASN MIX CAN BE
EXPECTED...WHICH WILL TRANSITION TO -SHSN BY 03Z. ONLY AN INCH OR
TWO OF SNOWFALL WILL BE POSSIBLE...BUT WARM GROUND WILL LIKELY
MELT THE SNOW AS IT FALLS. KALS WILL SEE MORE SHOWERY NATURE TO
SNOWFALL TONIGHT...WITH OFF AN ON VFR TO MVFR CONDITIONS. ALL 3
TAF SITES WILL SEE GUSTY WINDS THROUGH THE EVENING...WITH KPUB AND
KCOS SEEING GUSTS TO AROUND 40 KTS THROUGH THE EVENING...AND
REMAINING AROUND 15-30 KTS THROUGH THE NIGHT. KALS WILL STAY GUSTY
OUT OF THE SOUTH AT 20- 35KTS THIS EVENING...THEN SWING AROUND TO
THE EAST AROUND 10 KTS THEN DECREASE THROUGH THE LATE EVENING AND
OVERNIGHT.
SHOULD SEE IMPROVING CONDITIONS ON MONDAY WITH VFR CIGS SLOWLY
CLEARING FOR KPUB AND KCOS. KALS MAY SEE SOME VFR CLOUDS REDEVELOP
IN THE AFTERNOON WITH CONVECTIVE RAIN AND SNOW SHOWERS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM 9 PM THIS EVENING TO 8 AM MDT MONDAY FOR
COZ083>089-094.
WINTER STORM WARNING UNTIL 9 AM MDT MONDAY FOR COZ058>063-073-
076-080>082-084.
WINTER WEATHER ADVISORY UNTIL 9 AM MDT MONDAY FOR COZ072-074-075-
077>079.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY FOR COZ066-068-085.
&&
$$
SHORT TERM...KT
LONG TERM...PETERSEN
AVIATION...KT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
959 PM EDT MON MAY 12 2014
.SYNOPSIS...
A BACK DOOR COLD FRONT SWEEPS ACROSS THE REGION THIS EVENING
WITH TEMPERATURES NOTICEABLY COOLER BEHIND THE FRONT TONIGHT AND
TUE...ALONG WITH MAINLY DRY WEATHER. MARITIME HIGH PRESSURE
PROVIDES COOL AND MAINLY DRY WEATHER INTO WEDNESDAY. A PERIOD OF
UNSETTLED WEATHER IS LIKELY THURSDAY INTO THE WEEKEND. THE BEST
CHANCE OF HEAVY RAIN AND POSSIBLE THUNDERSTORMS IS EXPECTED FRIDAY
NIGHT INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
10 PM UPDATE...
WEAK BACKDOOR COLD FRONT HAS ALREADY MADE ITS WAY S THIS EVENING
AND IS NOW DRAPED ALMOST IN LINE WITH ROUTE 2 ACROSS NRN MA. THE
ONLY NOTE OF THIS IS A RAPID DROP IN DWPTS TO THE LOW 40S AND A
WIND SHIFT TO THE N-NE. IT HAS STRUGGLED TO MAKE MUCH MORE
SOUTHWARD PROGRESS THIS EVENING...BUT IS LIKELY TO CONTINUE A SLOW
PUSH TO THE S WITH TIME THROUGH THE EARLY MORNING HOURS.
THEREFORE...EXPECTING A GRADUAL SHIFT FROM THE SW WINDS SEEN AT
MANY LOCATIONS...TO THE N-NE FROM NOW THROUGH ABOUT 3-4AM FROM N
TO S. TEMPS ARE LIKELY TO START AS CLEAR...EXCEPT FOR SOME
LEFTOVER CU DEBRIS ACROSS CT AND SRN RI...WITH MORE MID AND HIGHER
CLOUDS BUILDING IN AS THE FRONT STALLS SW OF THE REGION AS A WARM
FRONT. RAP SEEMED TO BE THE BEST SO FAR AT HANDLING THE FRONTS
MOVEMENT SO MANY OF THE UPDATED PARAMETERS THIS EVENING WERE BASED
ON ITS FORECAST...HOWEVER GIVEN THE SLOW PROGRESSION IT MAY BE A
BIT TOO FAST LATER ON.
PREVIOUS DISCUSSION...
SPECTACULAR DAY IN PROGRESS WITH 3 PM TEMPS IN THE M80S INLAND ALONG
WITH A REFRESHING WESTERLY BREEZE. CLOSER TO THE COAST SEABREEZES
KEEPING TEMPS IN THE 70S TO NEAR 80 EXCEPT CAPE COD AND ISLANDS
WHERE TEMPS ARE 65-70. VERY COMFORTABLE WITH DEW PTS IN THE 30S
INLAND AND 40S AT THE COAST.
MAINLY DRY WEATHER TONIGHT HOWEVER WATCHING AREA OF CLOUD
DEVELOPMENT OVER PA WITH NOTICEABLE CYCLONIC SWIRL AS LOW AMPLITUDE
SHORT WAVE MOVES ACROSS THIS AREA. THIS SHOWS UP NICELY ON THE SPC
MESOANALYSIS ESPECIALLY AT H7. SHOWERS TRYING TO DEVELOP BUT
INSTABILITY IS LACKING...BOTH AT THE SURFACE AND ALOFT. HOWEVER THIS
ACTIVITY IS ON THE LEADING EDGE OF A WARM FRONTAL BOUNDARY WITH DEW
PTS IN THE 50S ACROSS PA/NJ/NYC AND LONG ISLAND. IN ADDITION THIS
SHORT WAVE TROUGH IS ACCOMPANIED BY SOME MID LEVEL MOISTURE WITH K
INDICES OF 30-34 FROM SOUTHWEST NY STATE EXTENDING ESE TO NYC. THE
BULK OF THIS MID LEVEL MOISTURE AND ASSOCIATED FORCING FOR ASCENT
SHOULD SLIDE SOUTHWEST OF THE AREA BUT CAN`T RULE OUT A STRAY SHOWER
ACROSS SOUTHWEST MA /SPRINGFIELD AREA/ AND ACROSS CT. HRRR
LOOKS TOO WET. OTHERWISE MAINLY DRY CONDITIONS PREVAIL.
OTHER FEATURE OF INTEREST WILL BE SHORT WAVE MOVING INTO NEW
BRUNSWICK. AS THIS FEATURE SLIDES SOUTHEAST OF NOVA SCOTIA ITS
ATTENDING BACKDOOR COLD FRONT WILL MOVE ACROSS THE REGION THIS
EVENING. TIMING...03Z-06Z EASTERN MA AND RI THEN 06Z-12Z ELSEWHERE.
AS USUAL THIS BACKDOOR FRONTS TYPICALLY PASS THRU THE REGION DRY.
NOTICEABLY COOLER BEHIND THE FRONT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
TUESDAY...MARITIME HIGH SETTLES SOUTHWARD INTO THE GULF OF MAINE
WITH NE WINDS ACROSS THE CHILLY EASTERN NEW ENGLAND WATERS /SST IN
THE L50S/ ADVECTING A COOL AIRMASS INTO THE AREA. HIGHS TUE ONLY IN
THE 50S ACROSS EASTERN MA AND 60S ELSEWHERE. IN FACT IT MAY EVEN BE
COOLER ALONG THE IMMEDIATE EASTERN MA COAST WITH 2 METER TEMPS FROM
THE EC/NAM/GFS AND SREF ALL SUGGEST HIGHS ONLY IN THE U40S CAPE
COD/ISLANDS AND IMMEDIATE EASTERN MA COASTLINE UP THRU CAPE ANN.
DEEP LAYER RIDGE APPROACHING FROM THE WEST HOWEVER LOTS OF MID AND
HIGH CLOUDS AS WARMER AIR ALOFT OVERRUNS THE COOL MARITIME AIRMASS
AT THE SURFACE. MAINLY A DRY DAY WITH ANY PRECIP IN THE FORM OF JUST
A SPOT SHOWER OR SPRINKLE.
TUESDAY NIGHT...MORE OF THE SAME MAINLY DRY AND COOL WITH MARITIME
SURFACE HIGH OVER THE AREA ALONG WITH DEEP LAYER RIDGE OVERHEAD.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...
* DRY WEDNESDAY
* UNSETTLED THU INTO WEEKEND WITH POTENTIAL FOR HEAVY RAIN
* REMAINING COOL EARLY NEXT WEEK WITH SPOTTY SHOWERS
FAIRLY CONFIDENT ON EVOLVING LARGE SCALE PATTERN LATER THIS WEEK
AND THROUGH WEEKEND. BUILDING RIDGE OVER WEST COAST LEADS TO
DEEPENING FULL LATITUDE TROUGH OVER EASTERN STATES...WHICH
EVENTUALLY CLOSES ITSELF OFF OVER GREAT LAKES AS RIDGING PERSISTS
ACROSS NORTH ATLANTIC. RESULT IS PERSISTENT S/SE FLOW WHICH WILL
LEAD TO PERIODS OF AT LEAST ISOLATED OR SCATTERED SHOWERS.
RAINFALL SHOULD BECOME MORE WIDESPREAD AS SLOW MOVING FRONT
APPROACHES LATE FRI/SAT...WHEN LOCALLY HEAVY RAINFALL IS ALSO
POSSIBLE.
WED...
UPPER RIDGE BUILDS OVER NEW ENGLAND WHILE HIGH PRESSURE REMAINS
OFFSHORE. THIS SHOULD MAINTAIN DRY WEATHER WITH NEAR SEASONABLE
TEMPERATURES...ASIDE FROM IMMEDIATE COAST DUE TO ONSHORE FLOW.
THU INTO SAT...
MAY SEE FEW SHOWERS THU DUE MORE TO PROLONGED S FLOW AS OPPOSED TO
SLOW MOVING COLD FRONT WHICH SHOULD STILL BE WELL TO OUR W. COULD
BE RATHER WARM/MUGGY DAY THU AS WEAK RIDGING STILL PREVAILS...
WHICH MAY ALLOW CLOUDS TO BREAK FOR A TIME.
ENSEMBLES AND 12Z MODELS SUGGEST MAIN WINDOW FOR MORE WIDESPREAD
SHOWERS/ISOLATED THUNDERSTORMS WILL BE LATE FRI INTO SAT MORNING
AS FRONT PUSHES THROUGH. DEEP S FLOW WITH UPPER LOW CLOSING OFF
ACROSS GREAT LAKES WILL BRING ANOMALOUSLY MOIST /+2 TO +3 SD/
AIRMASS INTO REGION ALONG WITH FAIRLY POTENT 850 MB JET. EARLY
INDICATIONS ARE FOR AS MUCH AS 1 TO 2 INCHES OF RAIN DURING THIS
TIME FRAME PER ENSEMBLE PROBABILITIES.
SUN AND MON...
DESPITE FRONT MOVING OFFSHORE...CLOSED UPPER LOW MEANS COOL/SHOWERY
PERIOD MAY BE IN STORE. 12Z GFS IS MOST AGGRESSIVE WITH THIS
FEATURE AS IT IS DAMPENED OUT IN ENSEMBLE MEANS.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE.
AFTER 00Z...BACKDOOR FRONT FROM MAINE MOVES SOUTHWEST-WARD INTO
MA/RI/CT BEGINNING 01Z/02Z FIRST ACROSS NORTHEAST MA AND THEN
SOUTHWEST-WARD AS THE EVENING PROGRESSES. FRONT WILL COME THRU DRY
WITH ANY SHOWER ACTIVITY ACROSS THE LOWER HUDSON VALLEY OF
NY/NYC/LONG ISLAND...POSSIBLY CLIPPING CT.
TUE AND TUE NIGHT...VFR WITH MAINLY DRY WEATHER. ANY PRECIP WOULD
BE VERY LIGHT IN THE FORM OF SPRINKLES. NE WINDS TUE WITH GUSTS UP
TO 20 KT ALONG THE COAST...BECOME SE TUE NIGHT.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WEDNESDAY...HIGH CONFIDENCE.
VFR WITH POSSIBLE MVFR CIGS NEAR COAST.
THURSDAY...MODERATE CONFIDENCE.
MVFR IN SCT SHOWERS. IFR POSSIBLE NEAR COAST IN FOG/DRIZZLE.
FRIDAY INTO SATURDAY...MODERATE CONFIDENCE.
MVFR/IFR IN MORE WIDESPREAD SHOWERS AND ISOLATED TSTMS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH TUESDAY NIGHT.
TONIGHT...SW WINDS EARLY THIS EVENING AND THEN BECOMING NE LATER
THIS EVENING AND OVERNIGHT AS BACKDOOR FRONT FROM MAINE SLIPS
SOUTHWARD. NE WINDS 15-20 KT WITH A FEW GUSTS UP TO 25 KT. THUS A
SMALL CRAFT ADVISORY HAS BEEN ISSUED. DRY WEATHER WITH GOOD VSBY.
LOW RISK OF A SPOT SHOWER THIS EVENING RI WATERS.
TUE...NE WINDS 15-20 KT WITH GUSTS UP TO 25 KT IN THE MORNING...WITH
WINDS SLACKENING OVER THE NORTHERN MA WATERS AS THE DAY PROGRESSES.
DRY WEATHER WITH GOOD VSBY PREVAILS.
TUE NIGHT...NE WINDS DIMINISH AND BECOME SE. MAINLY DRY WEATHER AND
GOOD VSBY.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WEDNESDAY...HIGH CONFIDENCE.
HIGH PRESSURE REMAINS OFFSHORE WITH S/SE FLOW ACROSS WATERS.
INCREASING E SWELL BUT SHOULD STAY BELOW SCA. MAY SEE AREAS OF
FOG/DRIZZLE LATER IN DAY OR AT NIGHT.
THURSDAY INTO SATURDAY...MODERATE CONFIDENCE.
PERSISTENT S/SE WINDS SHOULD REMAIN BELOW 25 KT BUT SEAS WILL
SLOWLY BUILD THROUGH PERIOD...PROBABLY REACHING 5 TO 8 FT ON OUTER
WATERS. AREAS FOG SHOULD PREVAIL ALONG WITH AT LEAST SCATTERED
SHOWERS. BETTER CHANCE OF WIDESPREAD SHOWERS/FEW THUNDERSTORMS
LATE FRI INTO SAT AS SLOW MOVING COLD FRONT APPROACHES WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 7 PM EDT TUESDAY FOR
ANZ232>237-254>256.
SMALL CRAFT ADVISORY UNTIL 9 AM EDT TUESDAY FOR ANZ230-231-250-
251.
&&
$$
SYNOPSIS...NOCERA/JWD
NEAR TERM...NOCERA/DOODY
SHORT TERM...NOCERA
LONG TERM...JWD
AVIATION...NOCERA/JWD
MARINE...NOCERA/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
346 AM EDT SUN MAY 11 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS OUR REGION EARLY THIS MORNING...BRINGING
MORE SCATTERED SHOWERS. HIGH PRESSURE BUILDS IN LATER TODAY.
SCATTERED SHOWERS...AND A THUNDERSTORM OR TWO...ARE POSSIBLE
MONDAY AFTERNOON AS ANOTHER WARM FRONT APPROACHES. BACK DOOR COLD
FRONT WILL SWING THROUGH ON TUESDAY ALLOWING FOR HIGH PRESSURE ON
WEDNESDAY AND BELOW AVERAGE TEMPS. SEASONABLE TEMPERATURES AND
UNSETTLED WEATHER ARE ANTICIPATED THURSDAY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT WAS LOCATED ACROSS RI AND EASTERN MA...AND CONTINUING
TO MARCH OFFSHORE. DEW POINTS WILL TAKE A LITTLE LONGER TO DROP
OFF THOUGH...WITH THE LEADING EDGE OF LOW-LEVEL DRY AIR JUST
MOVING INTO CENTRAL SOUTHERN NEW ENGLAND.
REGIONAL RADARS SHOWING ANOTHER AREA OF SHOWERS MOVING ACROSS
SOUTHERN NEW ENGLAND. LATEST RUNS OF THE HRRR AND RAP MODELS ARE
HANDLING THIS AREA WELL...SO WILL USE THEM TO ADJUST THE TIMING OF
RAINFALL THIS MORNING. LATEST MESOANALYSIS SHOWS A DEARTH OF
INSTABILITY...SO THINKING THUNDERSTORMS ARE NOT VERY LIKELY. SOME
HIGHER REFLECTIVITY ALONG THE SOUTH COAST...SO WILL CONTINUE TO
MONITOR POTENTIAL FOR THUNDERSTORMS.
ONCE THIS COLD FRONT MOVES OFFSHORE BY MID MORNING...EXPECTING
BEAUTIFUL WEATHER FOR THE REST OF MOTHERS DAY. HIGH PRESSURE
ARRIVES DURING THE DAY. PLENTY OF SUNSHINE TODAY...BUT
TEMPERATURES WILL LIKELY NOT BE AS HIGH AS SATURDAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
TONIGHT...EXPECT HIGH PRESSURE TO SHIFT EAST. WILL SEE MOSTLY
CLEAR SKIES EARLY...THEN SOME HIGH CLOUDS WILL START TO MOVE IN
FROM THE WEST AFTER MIDNIGHT. LIGHT WEST WINDS WILL BE IN PLACE...
SO EXPECT TEMPS TO ONLY FALL BACK TO THE MID 40S TO LOWER
50S...POSSIBLY THE MID 50S IN THE URBAN CENTERS.
MONDAY...A HIGH PRESSURE TO OUR SOUTH AND PLENTY OF SUNSHINE TO
START THE DAY WILL LEAD TO MAXIMUM TEMPERATURES AROUND 80 DEGREES.
MODEL SOUNDINGS DEPICT WEAK INSTABILITY...SO THINKING SHOWERS
WOULD BE MORE LIKELY THAN THUNDERSTORMS. THIS COULD CHANGE IF DEW
POINTS GET HIGHER THAN CURRENTLY FORECAST. THE MOST LIKELY PERIOD
FOR SHOWERS WILL BE DURING THE AFTERNOON HOURS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* BACK DOOR COLD FRONT ON TUESDAY
* HIGH PRESSURE ON WEDNESDAY
* SEASONABLE TEMPS AND UNSETTLED WEATHER THURSDAY THROUGH THE WEEKEND
MODELS AND CONFIDENCE...
LATEST 00Z GUIDANCE IS IN AGREEMENT SHOWING A STRONG WEST COAST
RIDGE WHICH WILL SUPPORT A BROAD/DEEP TROUGH SETTLING OVER THE ERN
HALF OF THE CONUS. CLOSER AT HOME...A BACK DOOR COLD FRONT WILL
SWING THROUGH THE REGION ON TUESDAY FOLLOWED BY HIGH PRESSURE
BUILDING IN THE GULF OF MAINE. AS THE TROUGH MOVES TOWARDS NEW
ENGLAND...A NORTH ATLANTIC RIDGE WILL HOLD STEADY...AND EVENTUALLY
BLOCKS THE PROGRESSION OF THE TROUGH RESULTING IN POSSIBLE CUT-
OFF LOW NEAR THE GREAT LAKES BY FRIDAY. A LOT OF TIMING ISSUES
WITH THIS FORECAST BUT CONFIDENCE IS INCREASING THAT ASIDE FROM
HIT OR MISS IN THE MEDIUM RANGE...THE LONG TERM WILL BE UNSETTLED
AND SEASONABLE. SOLUTION SPREAD IS GRADUALLY NARROWING BUT
GFS/GEFS ARE CONTINUING TO BRING LEADING HGT FALLS INTO THE EAST
FASTER THAN MOST OTHER GUIDANCE IN THE MID-LATE WEEK TIME FRAME.
TRENDS AND CONTINUITY OVER MULTIPLE DAYS HAVE BEEN FAVORING SLOWER
TIMING AS SUPPORTED BY THE AMPLIFIED NATURE OF THE APPROACHING
TROUGH. THEREFORE TRENDED THIS FORECAST TOWARDS THE EC ENSEMBLES
AS WELL AS WPC.
DETAILS...
TUESDAY INTO WEDNESDAY...
GUIDANCE IS ON COURSE FOR A BACK DOOR COLD FRONT TO MOVE ACROSS
THE REGION ON TUESDAY AS HIGH PRESSURE IN THE GULF OF MAINE
BUILDS. FRONT WILL PUSH THROUGH TUESDAY MORNING ALLOWING FOR COOL
MARITIME AIR TO FILTER INTO SOUTHERN NEW ENGLAND. BREAKS IN THE
CLOUD COVER MAY ALLOW FOR THE WESTERN HALF TO WARM IN THE
60S...BUT CLOSER TO THE COASTLINE WILL STRUGGLE TO GET OUT OF THE
50S. THIS EASTERLY FLOW OFF THE WATERS WILL FEEL VERY CHILLY
COMPARED TO THE 70-80F THE REGION HAS EXPERIENCED THIS WEEKEND.
BECAUSE OF THE ONSHORE FLOW...CANT RULE OUT FOG/DRIZZLE AND LOW
CLOUDS ESP ACROSS EASTERN COASTLINES.
HIGH PRESSURE WILL BUILD IN ACROSS THE GULF OF MAINE KEEPING MOST OF
THE REGION DRY AND TEMPS SEASONABLE ON WEDNESDAY. HOWEVER STALLED
BOUNDARY ACROSS CENTRAL NY MAY ALLOW FOR SOME ISO SHOWERS ACROSS
WESTERN ZONES. ONCE AGAIN COOLER TEMPS ON WED DUE TO ONSHORE FLOW.
THURSDAY AND BEYOND...
STRONG HIGH PRESSURE TO THE EAST HAS SLOWED THE PROGRESSION OF
THE DIGGING TROUGH AND STALLS IT JUST WEST OF THE REGION. HOWEVER
BY THURSDAY...HIGH PRESSURE WILL MOVE OUT TO SEA ALLOWING FOR THE
TROUGH TO MAKE ITS WAY TOWARDS THE NORTHEAST. EXPECT SEVERAL WEAK
WAVES TO DEVELOP AHEAD OF THIS TROUGH WHICH WILL APPROACH THE AREA
DURING THURSDAY INTO FRIDAY. ALTHOUGH EXACT TIMING OF EACH WAVE
IS STILL UNCERTAIN...IT APPEARS THAT THE BEST CHANCE FOR HIGHER
PRECIP LOOKS TO BE FRIDAY AS LOW PRESSURE SYSTEM DEVELOPS ALONG
THE FRONT. STRONG LLJ AND INCREASING MOISTURE TRANSPORT SUPPORTS
THE IDEA OF THE POSSIBILITY OF HEAVY RAINFALL. ESPECIALLY SINCE
THE TROUGH IS TAPPING INTO DEEP GULF MOISTURE AS WELL AS A
POSSIBLE SURFACE LOW MOVING UP FROM THE BAHAMAS. BECAUSE OF THE
UNCERTAINTY ON EXACT TIMING...CONTINUED TO MENTION CHANCE POPS
FOR THURSDAY AND FRIDAY. HELD OFF ON LIKELY POP FOR FRIDAY BECAUSE
OF THE LOW CONFIDENCE ON THE EXACT TIMING...BUT WOULD NOT BE
SURPRISED IF NEXT SHIFT INCREASES POPS.
MODELS DIFFER ON THE TIMING ON THE EXIT OF THE SYSTEM ON
SATURDAY...IN FACT SOME MODELS WANT TO DRY SLOT SOUTHERN NEW
ENGLAND. HAVE LOW CONFIDENCE IN THIS OCCURRING AS A SLIGHT CHANGE IN
THE PATH COULD LEAD TO A WET WEEKEND. OVERALL IT APPEARS THAT THE
STRONG ATLANTIC RIDGE WILL STALL THE SYSTEM JUST EAST OF THE
REGION ON SATURDAY AND INTO SUNDAY. THEREFORE CONTINUED TO
MENTION A SLIGHT CHANCE OF PRECIP.
A SEASONABLE BUT HUMID AIR MASS WILL OVERSPREAD THE REGION WITH SW
FLOW TAPPING INTO THE GULF...ADVECTING HIGHER DEWPOINTS AHEAD OF
THE TROUGH. FOG IS A POSSIBILITY ON THURSDAY AND ON FRIDAY. HIGHS
WILL GENERALLY TOP OFF IN THE UPPER 60S TO LOW 70S WITH COOLER
CONDITIONS ALONG THE COAST...ESP THE SOUTH COAST DUE TO SOUTHERLY
FLOW.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY/...
THROUGH 12Z...HIGH CONFIDENCE. VFR WITH SCATTERED MVFR IN SHOWERS.
TODAY...HIGH CONFIDENCE. VFR CONDITIONS PREVAIL. WEST WIND GUSTS
UP TO 20 KT POSSIBLE.
TONIGHT...HIGH CONFIDENCE. VFR.
MONDAY...HIGH CONFIDENCE VFR CONDITIONS TO START. IF SHOWERS
START TO POP DURING THE AFTERNOON...CIGS SHOULD DROP AND VSBY MAY
DROP...TO MVFR OR LOCALIZED BRIEF IFR CONDITIONS.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT...MODERATE CONFIDENCE. VFR WITH MVFR CONDITIONS IN SCT
SHOWERS/TSTORMS.
TUESDAY INTO WEDNESDAY...MODERATE CONFIDENCE. BACK DOOR COLD
FRONT WILL MOVE THROUGH SWITCHING THE WESTERLY WINDS TO THE EAST
ALLOWING FOR FOG AND DRIZZLE TO ROLL IN. MVFR CONDITIONS WILL
POSSIBLE IFR. CONDITIONS IMPROVING ON WEDNESDAY TO VFR.
THURSDAY...LOW CONFIDENCE. STAGNANT COLD FRONT SLOWLY MOVES EAST
WITH A CHANCE OF A WEAK SHOWER ESP ACROSS WESTERN SITES. WINDS
WILL SWITCH TO THE SOUTHEAST. OVERCAST SKIES WITH VFR/MVFR CIGS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY/...MODERATE CONFIDENCE.
TODAY AND TONIGHT...HIGH PRESSURE BUILDS ACROSS THE WATERS.
EXPECT W WINDS 15 KT OR LESS. GUSTS MAY APPROACH 20 KT ON
NEARSHORE WATERS THIS AFTERNOON. SEAS SHOULD REMAIN BELOW 5 FT.
MONDAY...INCREASING SOUTHWEST WINDS WILL SLOWLY BUILD SEAS ACROSS
THE OUTER COASTAL WATERS...BUT STILL EXPECTING CONDITIONS TO
REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MODERATE CONFIDENCE THROUGH PERIOD.
MONDAY NIGHT-TUESDAY...A WARM FRONT WILL APPROACH THE WATERS FROM
THE SOUTH ALLOWING FOR SCATTERED SHOWERS AND POSSIBLE
THUNDERSTORMS. BEST LOCATIONS WILL BE IN THE SOUTHERN AND WESTERN
MOST WATERS.
TUESDAY INTO WEDNESDAY...WESTERLY WINDS WILL SHIFT TO THE EAST ON
TUESDAY AS BACK DOOR COLD FRONT MOVES ACROSS THE WATERS. FOG AND
DRIZZLE POSSIBLE AND EASTERLY SWELL INCREASES SEAS. HIGH PRESSURE
WILL BUILD OVER THE EASTERN WATERS ON WEDNESDAY. SCA MAY BE NEEDED
FOR THE PERIOD.
THURSDAY...LOW CONFIDENCE...STATIONARY FRONT WILL SLOWLY MOVE EAST
WITH A CHANCE OF A WEAK SHOWER. SEAS REMAIN AT 5 FT SO SCA MAY
CONTINUE TO BE NEEDED. SE WINDS AHEAD OF THE FRONT REMAIN BELOW
25KTS TO START BUT MAY INCREASE LATE IN THE PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ254-
256.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ255.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
322 AM EDT SUN MAY 11 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS OUR REGION EARLY THIS MORNING...BRINGING
MORE SCATTERED SHOWERS. HIGH PRESSURE BUILDS IN LATER TODAY.
SCATTERED SHOWERS...AND A THUNDERSTORM OR TWO...ARE POSSIBLE
MONDAY AFTERNOON AS ANOTHER WARM FRONT APPROACHES. A BACK DOOR
COLD FRONT WILL MOVE WEST ACROSS THE REGION TUESDAY...ALLOWING
FOR HIGH PRESSURE ON WEDNESDAY. SEASONABLE TEMPERATURES AND
UNSETTLED WEATHER ARE FORECAST FOR THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
A COLD FRONT WAS LOCATED ACROSS RI AND EASTERN MA...AND CONTINUING
TO MARCH OFFSHORE. DEW POINTS WILL TAKE A LITTLE LONGER TO DROP
OFF THOUGH...WITH THE LEADING EDGE OF LOW-LEVEL DRY AIR JUST
MOVING INTO CENTRAL SOUTHERN NEW ENGLAND.
REGIONAL RADARS SHOWING ANOTHER AREA OF SHOWERS MOVING ACROSS
SOUTHERN NEW ENGLAND. LATEST RUNS OF THE HRRR AND RAP MODELS ARE
HANDLING THIS AREA WELL...SO WILL USE THEM TO ADJUST THE TIMING OF
RAINFALL THIS MORNING. LATEST MESOANALYSIS SHOWS A DEARTH OF
INSTABILITY...SO THINKING THUNDERSTORMS ARE NOT VERY LIKELY. SOME
HIGHER REFLECTIVITY ALONG THE SOUTH COAST...SO WILL CONTINUE TO
MONITOR POTENTIAL FOR THUNDERSTORMS.
ONCE THIS COLD FRONT MOVES OFFSHORE BY MID MORNING...EXPECTING
BEAUTIFUL WEATHER FOR THE REST OF MOTHERS DAY. HIGH PRESSURE
ARRIVES DURING THE DAY. PLENTY OF SUNSHINE TODAY...BUT
TEMPERATURES WILL LIKELY NOT BE AS HIGH AS SATURDAY.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
TONIGHT...EXPECT HIGH PRESSURE TO SHIFT EAST. WILL SEE MOSTLY
CLEAR SKIES EARLY...THEN SOME HIGH CLOUDS WILL START TO MOVE IN
FROM THE WEST AFTER MIDNIGHT. LIGHT WEST WINDS WILL BE IN PLACE...
SO EXPECT TEMPS TO ONLY FALL BACK TO THE MID 40S TO LOWER
50S...POSSIBLY THE MID 50S IN THE URBAN CENTERS.
MONDAY...A HIGH PRESSURE TO OUR SOUTH AND PLENTY OF SUNSHINE TO
START THE DAY WILL LEAD TO MAXIMUM TEMPERATURES AROUND 80 DEGREES.
MODEL SOUNDINGS DEPICT WEAK INSTABILITY...SO THINKING SHOWERS
WOULD BE MORE LIKELY THAN THUNDERSTORMS. THIS COULD CHANGE IF DEW
POINTS GET HIGHER THAN CURRENTLY FORECAST. THE MOST LIKELY PERIOD
FOR SHOWERS WILL BE DURING THE AFTERNOON HOURS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HEADLINES...
* ABOVE AVERAGE TEMPS ON MONDAY
* BACK DOOR COLD FRONT ON TUESDAY AND WEDNESDAY
* UNSETTLED WEATHER THURSDAY THROUGH THE WEEKEND
OVERVIEW...
FLOW INCREASINGLY BECOME MORE WAVY OVER THE UNITED STATES AS
SHORTWAVE DIVES SOUTH ALONG A TROUGH IN THE WESTERN UNITED STATES
WHILE A RIDGE BUILDS IN THE EAST. NORMALLY THE BUILDING RIDGE
MEANS PLEASANT WEATHER...BUT THIS TIME A HIGH PRESSURE SYSTEM IN
EASTERN CANADA HAS A SAY IN WHAT HAPPENS AS A LOBE OF THE HIGH
PRESSURE SYSTEM DROPS DOWN THE EAST COAST AND ALLOWS A COOLER
OCEAN AIR MASS TO FLOW INTO THE NORTHEAST ALONG A BACKDOOR COLD
FRONT. TIMING ISSUES IN MODELS AS TO WHEN THE LOBE DOES DROP DOWN
INTO THE REGION IS READILY SEEN. HAVE STAYED WITH ENSEMBLE AND WPC
GUIDANCE IN THIS FORECAST AS FAR AS TIMING AND SENSIBLE WEATHER
GOES FOR THIS PERIOD OF RATHER DIVERGENT MODEL SOLUTIONS.
DAILIES...
MONDAY NIGHT...A WARM FRONT ASSOCIATED WITH A LOW PRESSURE SYSTEM
OVER THE NORTHERN MIDWEST APPROACHES THE REGION AROUND EARLY NIGHT
HOURS WITH SHOWERS POSSIBLE ESPECIALLY IN WESTERN SECTIONS OF MA
AND CT.
TUESDAY AND WEDNESDAY...WITH THE LOBE OF HIGH PRESSURE BEGINNING TO
WORK ITS WAY SOUTH AND WEST FROM SOUTHEASTERN CANADA...NORTHEASTERN
ONSHORE FLOW SHOULD WORK ITS WAY INTO THE REGION ESPECIALLY BY THE
AFTERNOON HOURS. A NOTICEABLE TEMPERATURE DIFFERENCE BETWEEN MONDAY
AND TUESDAY SHOULD BE SEEN AS THE ONSHORE FLOW WILL BE BRINGING AN
AIR MASS CLOSE TO WHAT THE SEA SURFACE TEMPERATURES IN THE GULF OF
MAINE WHERE TEMPS ARE ONLY AROUND THE UPPER 40S TO LOW 50S. DIURNAL
HEATING SHOULD INCREASE TEMPERATURES FROM THERE...BUT MAX TEMPS MAY
NOT REACH 60 ON THE EASTERN SIDE OF THE FRONT. WITH ONSHORE
FLOW...CAN/T RULE OUT DRIZZLE/SHOWERS.
THURSDAY THROUGH THE WEEKEND...MAJOR DISCREPANCY IN THIS PERIOD AS
TO THE EXACT SENSIBLE WEATHER WITH THE TROUGH FROM THE WEST MOVING
IN. AN UPPER LEVEL LOW PRESSURE SYSTEM SHOULD FORM FROM THAT WITH
THE ABILITY TO DRAW MOISTURE IN FROM THE GULF AND A LOW FROM THE
TROPICS. A COLD FRONT HAS BEEN STALLED OUT OVER THE EASTERN SEA
BOARD SINCE TUESDAY AND THIS WILL HAVE WAVES RIDING NORTH OF IT
DURING THIS PERIOD. HAVE STAYED WITH WPC AND ENSEMBLES DURING THIS
PERIOD FOR SENSIBLE HIGHLIGHTS WITH THE HIGH AMOUNT OF SPREAD IN THE
DETERMINISTIC MODELS. FRIDAY AND SATURDAY HAVE THE BEST CHANCE FOR
ORGANIZED PRECIPITATION WITH THE UPPER LEVEL LOW MOVING TOWARD THE
REGION. TEMPS SHOULD REMAIN SEASONABLE DURING THIS TIME PERIOD AND
DEW POINTS SHOULD KEEP THIS PERIOD RATHER HUMID.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY/...
THROUGH 12Z...HIGH CONFIDENCE. VFR WITH SCATTERED MVFR IN SHOWERS.
TODAY...HIGH CONFIDENCE. VFR CONDITIONS PREVAIL. WEST WIND GUSTS
UP TO 20 KT POSSIBLE.
TONIGHT...HIGH CONFIDENCE. VFR.
MONDAY...HIGH CONFIDENCE VFR CONDITIONS TO START. IF SHOWERS
START TO POP DURING THE AFTERNOON...CIGS SHOULD DROP AND VSBY MAY
DROP...TO MVFR OR LOCALIZED BRIEF IFR CONDITIONS.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT...MODERATE CONFIDENCE. AS WARM FRONT MOVES IN...MAY
SEE MVFR CONDITIONS.
TUESDAY INTO WEDNESDAY...MODERATE CONFIDENCE. AS BACKDOOR COLD
FRONT MOVES THROUGH...WEST WINDS CHANGE TO NORTHEAST WINDS. COULD
SEE DRIZZLE AND FOG DURING THIS PERIOD AS WELL. MVFR CONDITIONS TO
START WILL CHANGE TO IFR FROM EAST TO WEST ALONG THE FRONT.
THURSDAY...LOW CONFIDENCE...STAGNANT COLD FRONT SLOWLY MOVES EAST
WITH A CHANCE OF A WEAK SHOWER. SE WINDS AHEAD OF THE FRONT REMAIN
BELOW THRESHOLDS. OVERCAST SKIES ALLOW FOR MVFR CONDITIONS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY/...MODERATE CONFIDENCE.
TODAY AND TONIGHT...HIGH PRESSURE BUILDS ACROSS THE WATERS.
EXPECT W WINDS 15 KT OR LESS. GUSTS MAY APPROACH 20 KT ON
NEARSHORE WATERS THIS AFTERNOON. SEAS SHOULD REMAIN BELOW 5 FT.
MONDAY...INCREASING SOUTHWEST WINDS WILL SLOWLY BUILD SEAS ACROSS
THE OUTER COASTAL WATERS...BUT STILL EXPECTING CONDITIONS TO
REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MODERATE CONFIDENCE THROUGH PERIOD.
MONDAY NIGHT-TUESDAY...AS WARM FRONT APPROACHES THE REGION...
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS SHOULD BE SEEN
ESPECIALLY IN SOUTHERN AND WESTERN MOST WATERS.
TUESDAY INTO WEDNESDAY...NORTHEAST WINDS OVERTAKE WEST WINDS FROM
EAST TO WEST AS BACKDOOR FRONT PUSHES THROUGH WITH COLDER AIR. FOG
AND DRIZZLE IS POSSIBLE IN ONSHORE FLOW WITH POSSIBLE SWELL IN SEAS
THAT HAVE 5FT WAVES. SCA MAY BE NEEDED FOR THE PERIOD.
THURSDAY...LOW CONFIDENCE...STAGNANT COLD FRONT SLOWLY MOVES EAST
WITH A CHANCE OF A WEAK SHOWER. SEAS REMAIN AT 5 FT SO SCA MAY
CONTINUE TO BE NEEDED. SE WINDS AHEAD OF THE FRONT REMAIN BELOW
25KTS TO START BUT MAY INCREASE LATE IN THE PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ254-
256.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ255.
&&
$$
SYNOPSIS...BELK/NMB/99
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...NMB/99
AVIATION...BELK/NMB/99
MARINE...BELK/NMB/99
AREA FORECAST DISCUSSION
NWS NEW YORK NY
133 AM EDT SUN MAY 11 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS LATE TONIGHT. HIGH PRESSURE THEN
BUILDS OVER THE AREA ON SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE
DEPARTS ON MONDAY...AND THEN A SERIES OF FRONTAL BOUNDARIES AND
WEAK LOW PRESSURE SYSTEMS WILL MOVE ACROSS THE REGION THROUGH THE
MIDDLE OF THE WEEK. A STRONGER COLD FRONT IMPACTS THE REGION LATE
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
05Z OBS INDICATED THAT COLD FRONT WAS JUST NW OF THE FORECAST
AREA. FINAL PUSH OF ORGANIZED PCPN ASSOCIATED WITH SHORTWAVE IS
CROSSING THE AREA OUT AHEAD OF THE COLD FRONT. SCT ACTIVITY RIGHT
ALONG THE BOUNDARY IS ALSO DEVELOPING FROM EASTERN PA THROUGH WRN
MA. WILL KEEP ISO THUNDER IN FORECAST FOR A FEW MORE HOURS...BUT
THREAT IS MINIMAL. HRRR HAS BEEN CONSISTENT IN PUSHING PCPN
THROUGH BETWEEN 03-07Z...LINGERING OVER FAR EASTERN LI AND SE CT
UNTIL 09Z...WHEN THE FRONT FINALLY CLEARS THE AREA. HAVE ADJUSTED
POPS TO ACCOUNT FOR THIS. NOT ANTICIPATING ANY FURTHER SEVERE
THREATS NOR FLOODING ISSUES.
ALSO...WITH RATHER LIGHT WESTERLY FLOW BEHIND THE FRONT...STILL THINKING
LOW LEVELS WILL BE SLOWER TO DRY OUT LATE TONIGHT.
THEREFORE...CONTINUE TO HAVE PATCHY FOG DEVELOPING LATE. LOWS
WERE A BLEND OF NAM12 AND MET GUIDANCE...HIGHER SIDE OF GUIDANCE.
TEMPS AND DEW PTS GENERALLY ON TRACK AS OF LATE THIS EVENING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
BEHIND THE COLD FRONT...MID LEVEL RIDGING WITH HIGH PRESSURE
BUILDING IN AT THE SURFACE FROM THE SOUTH AND WEST WILL PROMOTE
DRY WEATHER DURING THIS PERIOD. WITH THE WESTERLY FLOW
SUNDAY...EXPECTING A QUICK INCREASE TO TEMPERATURES IN THE MORNING
WITH HIGHS WELL ABOVE NORMAL ONCE AGAIN...IN THE MID 70S TO LOWER
80S RANGE FOR MOST PLACES. THE JET STREAM ALOFT WILL BE LIFTING
FARTHER NORTH OF THE REGION WITH THE RIDGING. HIGHS WERE TAKEN
FROM MAVS AND INCREASED TWO DEGREES. SKIES WILL BE CLEARING SUNDAY
AND THESE MOSTLY CLEAR SKIES LINGER INTO SUNDAY NIGHT. LOWS SUNDAY
NIGHT WILL BE COOLER THAN OF RECENT NIGHTS WITH RADIATIONAL
COOLING AS WINDS WILL BE LIGHT. LOWS SUNDAY NIGHT WERE TAKEN FROM
ECS AND CONVEY A RANGE FROM THE MID 40S ACROSS RURAL AND INTERIOR
LOCATIONS TO THE LOWER 60S NEAR NYC.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRES DEPARTS ON MONDAY AS A DEEP UPPER TROUGH DIGS INTO THE
CENTRAL U.S. THIS TROUGH WILL EXTEND FROM CANADA INTO THE GULF OF
MEXICO...AND SFC LOW PRES WILL DEVELOP OVER THE WESTERN GREAT LAKES
BEFORE TRACKING TO THE NORTHEAST INTO CANADA. MEANWHILE...A WARM
FRONT APPROACHES ON MONDAY...AND THEN WEAK LOW PRES FORMS ALONG THE
BOUNDARY AS IT LIFTS TO THE NORTH. THAT BOUNDARY WILL BECOME NEARLY
STATIONARY NORTH OF THE REGION ON TUESDAY. AS A RESULT...WILL EXPECT
SCATTERED SHOWERS AND TSTMS TO DEVELOP MONDAY AFTERNOON...MAINLY
ACROSS NORTHERN ZONES. UNSETTLED WEATHER CONTINUES INTO TUESDAY AS
HIGH PRES OVER EASTERN CANADA DROPS SOUTH INTO THE GOLF OF MAINE.
THE STATIONARY FRONT NORTH OF THE AREA WILL PUSH TO THE SOUTH AS A
BACK DOOR COLD FRONT...AND THEN THE HIGH ANCHORS ITSELF OVER THE
WESTERN ATLANTIC THROUGH THE END OF THE WEEK.
THE UPPER TROUGH OVER THE MIDWEST WILL SLOWLY TRACK EAST...BUT WILL
EFFECTIVELY BECOME BLOCKED BY THE OFFSHORE HIGH. SEVERAL WEAK
IMPULSES WILL DEVELOP AT THE BASE OF THE TROUGH...AND THOSE WILL
TRACK TOWARDS THE REGION...KEEPING UNSETTLED WEATHER IN THE FORECAST
THROUGH THE END OF THE WEEK.
THE HIGH MOVES TO THE EAST THURSDAY NIGHT...AND THEN THE UPPER
TROUGH MOVES INTO THE EASTERN U.S. THERE ARE SOME INDICATIONS THAT
THE TROUGH BECOMES NEGATIVELY TILTED...AND THEN LOW PRES WILL
DEVELOP OVER THE MID-ATLANTIC BEFORE MOVING THROUGH THE REGION
THURSDAY NIGHT THROUGH FRIDAY. WILL BUMP UP POPS TO LIKELY FOR MOST
OF THE REGION FOR THAT TIME FRAME. COULD BE SOME LINGERING SHOWERS
INTO SATURDAY AS SEVERAL STRONG SHORTWAVES DIVE INTO THE REGION AS
THE TROUGH MOVES OVERHEAD.
SUMMER-LIKE TEMPS CONTINUE ON MONDAY WITH HIGHS WELL ABOVE
NORMAL...TOPPING OFF IN THE LOW 80S WEST OF THE HUDSON RIVER AND IN
THE MID TO UPPER 70S MOST ELSEWHERE...AND COOLER NEAR THE COASTS.
TEMPS RETURN CLOSER TO NORMAL ON TUESDAY...TOPPING OFF IN THE UPPER
60S TO LOWER 70S WITH THE WARMEST TEMPS ONCE AGAIN WEST OF THE
HUDSON RIVER. BY WEDNESDAY...BEHIND THE BACK DOOR COLD FRONT AND
WITH ONSHORE FLOW...HIGHS WILL RANGE FROM THE UPPER 50S NEAR THE
COASTS TO THE MID 60S ACROSS THE INTERIOR. TEMPS WILL THEN TOP OFF
AROUND NORMAL TO CLOSE OUT THE WEEK...GENERALLY IN THE UPPER 60S.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT WILL PASSING THROUGH THE REGION OVERNIGHT...FOLLOWED
BY WEAK HIGH PRESSURE FOR SUNDAY.
GENERALLY VFR THROUGH THE PERIOD.
LIGHT TO MODERATE SHOWERS BETWEEN 05-08Z. A LOW CHANCE OF THUNDER
IS POSSIBLE...BUT CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAF. CIGS
COULD BRIEFLY DROP TO AROUND 3000 FT WITH ANY SHOWER ACTIVITY
HOWEVER WE ARE GENERALLY EXPECTING 4000-5000 FT CIGS WITH ANY
PCPN.
WEST-SOUTHWEST WINDS WILL SHIFT TO THE WEST-NORTHWEST BEHIND THE
FRONT. WIND SPEEDS WILL INCREASE DURING THE DAY SUNDAY...WITH GUSTS
MIXING IN AFTER 15Z. GUSTS INTO THE UPPER TEENS AND LOWER 20S. WINDS
TOMORROW MORNING/AFTN WILL HOVER AROUND 300 TRUE.
DRY WEATHER IS EXPECTED ON SUNDAY.
.OUTLOOK FOR 06Z MON THROUGH THURS...
.SUN NIGHT-MON...VFR.
.TUES-THURS...GENERALLY VFR WITH PERIODS OF MVFR OR LOWER WITH
PCPN.
&&
.MARINE...
PATCHY FOG CAN BE EXPECTED ACROSS THE WATERS TONIGHT WITH MOIST
LOW LEVELS. WINDS AND SEAS DIMINISHING TONIGHT...AND THOUGH WINDS
MAY BRIEFLY INCREASE IN THE WAKE OF THE COLD FRONT...NOT
ANTICIPATING ENOUGH TO REACH SCA CRITERIA ONCE AGAIN.
THEREFORE...HAVE CANCELLED THE SCA ON THE OCEAN WATERS.
SUB-SCA CONDITIONS ON TAP FOR SUNDAY INTO THE START THE NEW WEEK
WITH HIGH PRESSURE IN CONTROL. BY THE MIDDLE OF NEXT WEEK...SMALL
CRAFT CONDITIONS RETURN AS A PERSISTENT ONSHORE FLOW WILL HELP
PUSH OCEAN SEAS UP TO 3-5 FT.
&&
.HYDROLOGY...
UP TO AROUND A QUARTER INCH OF BASIN AVERAGE QPF IS POSSIBLE
THROUGH THE REMAINDER OF THE NIGHT. ANY FLOODING POTENTIAL IS
EXPECTED TO BE GENERALLY MINOR...PARTICULARLY FOR THOSE LOCATIONS
GETTING MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS.
SCATTERED SHOWERS/TSTMS COULD PRODUCE LOCALLY HEAVY RAIN FOR MOST OF
THE UPCOMING WEEK...BUT WIDESPREAD ORGANIZED PRECIPITATION OF 1/2"
QPF OR MORE WILL HOLD OFF UNTIL LATE NEXT WEEK WHEN LOW PRESSURE
TRACKS THROUGH THE REGION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1149 PM EDT MON MAY 12 2014
.SYNOPSIS...
THE BACK DOOR COLD FRONT IN CENTRAL NEW ENGLAND IS ON THE MOVE AND
WILL ARRIVE SOUTHWESTWARD THROUGH THE MID ATLANTIC STATES DURING
THE DAYLIGHT HOURS TUESDAY. THIS FRONTAL BOUNDARY WILL THEN SURGE
NORTH THROUGH THE REGION AS A WARM FRONT WEDNESDAY AND THURSDAY.
ANOTHER COLD FRONTAL BOUNDARY WILL PASS THROUGH THE REGION ON
FRIDAY. HIGH PRESSURE THEN WILL BUILD IN BEHIND THE COLD FRONT FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE FIRST BATCH OF SCATTERED HEAVY SHOWERS (500MB VORT MAX
ASSOCIATED) WERE SEEN DEPARTING EASTWARD FROM THE NJ COAST AT
0130Z.
NEXT BATCH OF SHOWERS AND TSTMS NOW MOVING SEWD FROM NW PA ARE
MODELED DIFFERENTLY BY THE HRRR/RAP. THE 23Z HRRR MOVES THEM NE PA
AND NW NJ IN THE 09Z-13Z TIME FRAME. THE RAP DISSIPATES THESE NW
OF KBWI AROUND 11Z WHEREAS THE 00Z/13 NAM SENDS THESE SHOWERS INTO
SE PA AROUND 12Z-13Z.
TEMPERATURES SHOULD REMAIN MILD WITH LOWS EXPECTED TO BE MAINLY
IN THE 60S WITH A LIGHT AND VARIABLE WIND.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
A COLD FRONT IS EXPECTED TO BEGIN ENTERING THE NORTHEASTERN PART
OF OUR FORECAST AREA AROUND DAYBREAK ON TUESDAY. STRONG HIGH
PRESSURE IS ANTICIPATED TO PUSH THE BOUNDARY SOUTHWESTWARD THROUGH
OUR REGION DURING THE MORNING AND EARLY AFTERNOON HOURS. THE FRONT
IS EXPECTED TO REACH PHILADELPHIA AROUND 1000 AM OR SO.
THE DEVELOPING EASTERLY FLOW SHOULD KEEP MAXIMUM TEMPERATURES IN THE
LOWER AND MIDDLE 70S IN MUCH OF NEW JERSEY. HIGHS ARE EXPECTED TO
REACH THE LOWER 80S ALONG THE WESTERN EDGE OF OUR FORECAST AREA FROM
BERKS COUNTY, PENNSYLVANIA DOWN INTO NORTHEASTERN MARYLAND.
AN AREA OF SHOWERS AND THUNDERSTORMS DROPPING SOUTHEAST FROM THE
GREAT LAKES REGION IS FORECAST TO AFFECT OUR REGION ON TUESDAY
MORNING. IT WILL FOLLOW THE MID LEVEL FLOW AND IT IS EXPECTED TO
IMPACT MAINLY OUR EASTERN PENNSYLVANIA COUNTIES AS IT INTERACTS WITH
THE COLD FRONT.
TUESDAY NIGHT...EAST- NORTHEAST FLOW WITH SOME SHOWERS POSSIBLE
BEHIND THE BACKDOOR COLD FRONT.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
WEDNESDAY THROUGH WEDNESDAY NIGHT: A CONTINUED LOW CHANCE FOR
SHOWERS THROUGH WEDNESDAY NIGHT. MODEL DIFFERENCES ARE PRESENT IN
HOW QUICK THE FRONT BEGINS TO PUSH NORTH AGAIN WITH A 4-5 STANDARD
DEVIATION SPREAD WITHIN THE ECMWF ENSEMBLE SUITE ON HIGH
TEMPERATURES WEDNESDAY. STUCK CLOSE TO THE MET AND MAV FROM PHILLY
SOUTH AND WENT A TOUCH COOLER FURTHER NORTHEAST DURING THE DAY
WEDNESDAY.
THURSDAY AND THURSDAY NIGHT: MORE CONFIDENT WE GET INTO THE WARM
SECTOR AND SEE MORE IN THE WAY OF SUNSHINE. SOUTHERLY FLOW AND 850 MB TEMPS
PUSHING 15C, SHOULD GET US INTO THE LOW 80`S FOR A GOOD PORTION OF
THE PHILLY METRO. FOCUS OF THE SHOWER CHANCE NORTH AND WEST OF
PHILLY IN LINE WITH THE 09Z SREF.
FRIDAY AND FRIDAY NIGHT: FAIRLY GOOD BET THAT PERIODS OF HEAVY RAIN
WILL OCCUR AHEAD OF THE FRONT. THOUGH STILL SOME TIMING DIFFERENCES
WITH THE DIFFERENT OPERATIONAL MODEL RUNS. THE 06Z GFS AND THE 00Z
CMC FOCUS THE HEAVY RAIN FRIDAY AFTERNOON AND NIGHT WHILE THE 00Z
AND 12Z ECMWF RUNS HAVE THE MAIN PERIOD OF RAIN ON FRIDAY. SEE HYDRO
SECTION FOR MORE ON THE OVERALL SET-UP FOR THE HEAVY RAIN EVENT.
RAMP UP POPS BY FRIDAY MORNING WITH HIGH LIKELY POPS INTO THE EARLY
EVENING. DID NOT CATEGORICAL POPS GIVEN THE TIMING UNCERTAINTY, DAY
VS NIGHT.
SATURDAY THROUGH MONDAY: NORTHWEST FLOW BEHIND THE COLD FRONT WITH
CAA AS WELL. WILL GO SLIGHTLY COOLER THAN MEX/WPC FOR HIGHS ON THE
WEEKEND. LEFT IN A SLIGHT CHANCE FOR A SHOWER OR TWO IN THESE
PERIODS AS A SHORTWAVE OR TWO MAY MOVE THROUGH THE REGION. 12Z ECMWF
IS SOUTH WITH THIS ON SUNDAY, WHILE THE GFS WOULD BRING ONE THROUGH
EARLY MONDAY.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...VFR WITH POSSIBLE MVFR VSBY IN FOG SOME TAF SITES
AFTER 06Z. LIGHT SOUTHWEST WIND.
TUESDAY...A COLD FRONT WILL PUSH SOUTHWESTWARD THROUGH OUR REGION.
SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE, ESPECIALLY
AROUND KRDG AND KABE TO KPHL. THE WIND IS FORECAST TO BECOME
NORTHEAST TO EAST AROUND 6 TO 10 KNOTS WITH GUSTS TO 15 KT. LOWER
CEILINGS...IN THE MVFR RANGE COULD BEGIN TO FILTER INTO THE REGION
AFTER 18Z.
TUESDAY NIGHT...MVFR TO IFR IN LOW CLOUDS FOG AND SCT SHOWERS.
OUTLOOK...
WEDNESDAY THROUGH WEDNESDAY NIGHT... MVFR TO IFR IN LOW CLOUDS,
FOG AND LIGHT RAIN SHOWERS.
THURSDAY: IMPROVING CONDITIONS TO VFR WITH SOUTH GUSTS OF 15-20
KNOTS.
THURSDAY NIGHT THROUGH FRIDAY NIGHT : VFR DETERIORATING TO MVFR/IFR
DURING THE DAY FRIDAY FROM WEST TO EAST WITH RAIN. SOUTHERLY FLOW
LLWS POSSIBLE JUST AHEAD OF THE FRONTAL PASSAGE FRIDAY NIGHT
BEFORE WINDS SHIFT TO THE NW. IMPROVING CONDITIONS LATE FRIDAY
NIGHT.
SATURDAY: VFR.
&&
.MARINE...
OVERNIGHT...NO SCA HEADLINE. A SOUTH TO SOUTHWEST WIND IS EXPECTED
INTO TONIGHT. WIND SPEEDS SHOULD DIMINISH FROM 10 TO 15 KNOTS INTO
THE 5 TO 10 KNOT RANGE.
TUESDAY...A COLD FRONT IS FORECAST TO PUSH SOUTHWEST THROUGH OUR
REGION. THE WIND WILL BECOME LIGHT AND VARIABLE IN ADVANCE OF THE
FRONT BEFORE SHIFTING TO THE NORTHEAST AND EAST. WIND SPEEDS ARE
EXPECTED TO INCREASE INTO THE 10 TO 15 KNOT RANGE. SCATTERED GUSTS
NEAR 25 KNOTS ARE POSSIBLE ON OUR OCEAN WATERS NORTH OF BARNEGAT
INLET. THE 25 KNOT GUSTS ARE NOT EXPECTED TO BE WIDESPREAD ENOUGH
TO WARRANT A SMALL CRAFT ADVISORY. WAVE HEIGHTS ON OUR OCEAN
WATERS SHOULD BUILD NEAR 4 FEET.
TUESDAY NIGHT...NO SCA HEADLINE ANTICIPATED ATTM.
OUTLOOK...
WEDNESDAY THROUGH THURSDAY MORNING: NO SCA HEADLINE ANTICIPATED
ATTM FOR EITHER SEAS OR WINDS.
THURSDAY AFTERNOON THROUGH SATURDAY: SCA CONDITIONS AS SEAS WILL
LIKELY BE OVER FIVE FEET, SCA WIND GUSTS POSSIBLE THURSDAY AND
FRIDAY AFTERNOONS.
&&
.HYDROLOGY...
THE FRONTAL BOUNDARY WILL BE SLOW MOVING ACROSS THE REGION WITH A
FAVORABLE SOUTHEAST FLOW PROVIDING PLENTIFUL ATLANTIC MOISTURE.
HOWEVER THE MAIN RAINFALL AXIS LOOKS PROGRESSIVE ATTM. PW VALUES CLOSE
TO 2 INCHES ALONG THE FRONT WILL CREATE A FAVORABLE ENVIRONMENT FOR
HEAVY SHOWERS AHEAD OF THE COLD FRONT. SMALL STREAM AND URBAN
RUNOFF IS POSSIBLE AS FFG IS BETWEEN 1 AND 2 INCHES FOR A SIX
HOUR PERIOD. RIGHT NOW A GENERAL 1-2 INCHES OF RAIN IS LIKELY WITH
THIS SYSTEM. LOCALLY HIGHER AMOUNTS ARE BEING INDICATED BY SEVERAL
GEFS MEMBERS, FUTURE UPDATES WILL CONTINUE TO HONE IN ON WHERE
THESE MIGHT OCCUR. RIGHT NOW THE TREND IS FOR THE RAIN SHIELD TO
BE MORE INTENSE ACROSS THE WESTERN PARTS OF THE CWA.
&&
.TIDES/COASTAL FLOODING...
TIDES WILL BE ASTRONOMICALLY HIGH DUE TO THE FULL
MOON THIS WEEK. OUR IN HOUSE MODEL SUGGESTS SOME TIDAL DEPARTURES OF
.2-.4 FEET WITH THE HIGH TIDAL CYCLES WHICH COULD RESULT IN SOME
SPOTTY MINOR TIDAL FLOODING. THE MAIN TIDAL CYCLES OF CONCERN ARE
WEDNESDAY AND THURSDAY NIGHTS.
&&
.RIP CURRENTS...
THE NWS MOUNT HOLLY SURF ZONE SEASON BEGINS THIS FRIDAY MORNING
MAY 16 AND IT WILL BEGIN ON AN UNSAVORY FORECAST NOTE.
WATER TEMPERATURES ARE STILL GENERALLY IN THE 50S IN THE SURF
ZONE. WHILE THESE ARE SLIGHTLY ABOVE NORMAL, IT PROBABLY WONT
MATTER MUCH.
FRIDAY IS EXPECTED TO BE A MODERATE OR HIGH RISK DAY FOR THE
FORMATION OF DANGEROUS RIP CURRENTS AS A PERSISTENT ONSHORE FLOW
WILL BE INCREASING WITH SUSTAINED WINDS OF 15 TO 25 KT AND A SE
WIND DRIVEN WHITE CAPPED SE SWELL OF 6 TO 9 FEET.
I WOULDNT BE RECOMMENDING ANY SURF ZONE SWIMMING FOR ANYONE IN OUR
NJ AND DE ATLANTIC BEACH WATERS FRIDAY OR EVEN SATURDAY WHEN A
MODERATE RISK FOR THE FORMATION OF DANGEROUS RIP CURRENTS PROBABLY
CONTINUES DESPITE IMPROVED WEATHER SINCE THERE WILL BE A LEFTOVER
5 FT SE SWELL.
FOR THE MEDIA AND ALL OTHERS USING THIS SECTION OF OUR AFD...LAST
YEAR WAS GOOD FORTUNE FOR OUR SURF ZONE WITH NO FATALITIES. COLDER
WATER MAY HAVE HELPED DURING THE EARLY PART OF THE WARM SEASON
WHEN PATROLS ARE LESS EVIDENT. STILL...AWARENESS CAN HELP AND WE
APPRECIATE YOUR CONTRIBUTIONS TOWARD ENSURING SAFETY ON OUR BEACH
SURF ZONE WATERS.
JUNE 1 TO 7 IS RIP CURRENT AWARENESS WEEK.
&&
.EQUIPMENT...
DIX 88D OTS UFN...AT LEAST INTO TUESDAY EVENING.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG/GAINES
NEAR TERM...DRAG/IOVINO/JOHNSON
SHORT TERM...IOVINO
LONG TERM...GAINES
AVIATION...DRAG/GAINES/IOVINO
MARINE...DRAG/GAINES/IOVINO
HYDROLOGY...
TIDES/COASTAL FLOODING...
RIP CURRENTS... 1148P
EQUIPMENT...1148P
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1104 PM EDT MON MAY 12 2014
.SYNOPSIS...
THE BACK DOOR COLD FRONT IN CENTRAL NEW ENGLAND IS ON THE MOVE AND
WILL ARRIVE SOUTHWESTWARD THROUGH THE MID ATLANTIC STATES DURING
THE DAYLIGHT HOURS TUESDAY. THIS FRONTAL BOUNDARY WILL THEN SURGE
NORTH THROUGH THE REGION AS A WARM FRONT WEDNESDAY AND THURSDAY.
ANOTHER COLD FRONTAL BOUNDARY WILL PASS THROUGH THE REGION ON
FRIDAY. HIGH PRESSURE THEN WILL BUILD IN BEHIND THE COLD FRONT FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE FIRST BATCH OF SCATTERED HEAVY SHOWERS (500MB VORT MAX
ASSOCIATED) WERE SEEN DEPARTING EASTWARD FROM THE NJ COAST AT
0130Z.
NEXT BATCH OF SHOWERS AND TSTMS NOW MOVING SEWD FROM NW PA ARE
MODELED DIFFERENTLY BY THE HRRR/RAP. THE 23Z HRRR MOVES THEM NE PA
AND NW NJ IN THE 09Z-13Z TIME FRAME. THE RAP DISSIPATES THESE NW
OF KBWI AROUND 11Z WHEREAS THE 00Z/13 NAM SENDS THESE SHOWERS INTO
SE PA AROUND 12Z-13Z.
TEMPERATURES SHOULD REMAIN MILD WITH LOWS EXPECTED TO BE MAINLY
IN THE 60S WITH A LIGHT AND VARIABLE WIND.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
A COLD FRONT IS EXPECTED TO BEGIN ENTERING THE NORTHEASTERN PART
OF OUR FORECAST AREA AROUND DAYBREAK ON TUESDAY. STRONG HIGH
PRESSURE IS ANTICIPATED TO PUSH THE BOUNDARY SOUTHWESTWARD THROUGH
OUR REGION DURING THE MORNING AND EARLY AFTERNOON HOURS. THE FRONT
IS EXPECTED TO REACH PHILADELPHIA AROUND 1000 AM OR SO.
THE DEVELOPING EASTERLY FLOW SHOULD KEEP MAXIMUM TEMPERATURES IN THE
LOWER AND MIDDLE 70S IN MUCH OF NEW JERSEY. HIGHS ARE EXPECTED TO
REACH THE LOWER 80S ALONG THE WESTERN EDGE OF OUR FORECAST AREA FROM
BERKS COUNTY, PENNSYLVANIA DOWN INTO NORTHEASTERN MARYLAND.
AN AREA OF SHOWERS AND THUNDERSTORMS DROPPING SOUTHEAST FROM THE
GREAT LAKES REGION IS FORECAST TO AFFECT OUR REGION ON TUESDAY
MORNING. IT WILL FOLLOW THE MID LEVEL FLOW AND IT IS EXPECTED TO
IMPACT MAINLY OUR EASTERN PENNSYLVANIA COUNTIES AS IT INTERACTS WITH
THE COLD FRONT.
TUESDAY NIGHT...EAST- NORTHEAST FLOW WITH SOME SHOWERS POSSIBLE
BEHIND THE BACKDOOR COLD FRONT.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
WEDNESDAY THROUGH WEDNESDAY NIGHT: A CONTINUED LOW CHANCE FOR
SHOWERS THROUGH WEDNESDAY NIGHT. MODEL DIFFERENCES ARE PRESENT IN
HOW QUICK THE FRONT BEGINS TO PUSH NORTH AGAIN WITH A 4-5 STANDARD
DEVIATION SPREAD WITHIN THE ECMWF ENSEMBLE SUITE ON HIGH
TEMPERATURES WEDNESDAY. STUCK CLOSE TO THE MET AND MAV FROM PHILLY
SOUTH AND WENT A TOUCH COOLER FURTHER NORTHEAST DURING THE DAY
WEDNESDAY.
THURSDAY AND THURSDAY NIGHT: MORE CONFIDENT WE GET INTO THE WARM
SECTOR AND SEE MORE IN THE WAY OF SUNSHINE. SOUTHERLY FLOW AND 850 MB TEMPS
PUSHING 15C, SHOULD GET US INTO THE LOW 80`S FOR A GOOD PORTION OF
THE PHILLY METRO. FOCUS OF THE SHOWER CHANCE NORTH AND WEST OF
PHILLY IN LINE WITH THE 09Z SREF.
FRIDAY AND FRIDAY NIGHT: FAIRLY GOOD BET THAT PERIODS OF HEAVY RAIN
WILL OCCUR AHEAD OF THE FRONT. THOUGH STILL SOME TIMING DIFFERENCES
WITH THE DIFFERENT OPERATIONAL MODEL RUNS. THE 06Z GFS AND THE 00Z
CMC FOCUS THE HEAVY RAIN FRIDAY AFTERNOON AND NIGHT WHILE THE 00Z
AND 12Z ECMWF RUNS HAVE THE MAIN PERIOD OF RAIN ON FRIDAY. SEE HYDRO
SECTION FOR MORE ON THE OVERALL SET-UP FOR THE HEAVY RAIN EVENT.
RAMP UP POPS BY FRIDAY MORNING WITH HIGH LIKELY POPS INTO THE EARLY
EVENING. DID NOT CATEGORICAL POPS GIVEN THE TIMING UNCERTAINTY, DAY
VS NIGHT.
SATURDAY THROUGH MONDAY: NORTHWEST FLOW BEHIND THE COLD FRONT WITH
CAA AS WELL. WILL GO SLIGHTLY COOLER THAN MEX/WPC FOR HIGHS ON THE
WEEKEND. LEFT IN A SLIGHT CHANCE FOR A SHOWER OR TWO IN THESE
PERIODS AS A SHORTWAVE OR TWO MAY MOVE THROUGH THE REGION. 12Z ECMWF
IS SOUTH WITH THIS ON SUNDAY, WHILE THE GFS WOULD BRING ONE THROUGH
EARLY MONDAY.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...VFR WITH POSSIBLE MVFR VSBY IN FOG SOME TAF SITES
AFTER 06Z. LIGHT SOUTHWEST WIND.
TUESDAY...A COLD FRONT WILL PUSH SOUTHWESTWARD THROUGH OUR REGION.
SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE, ESPECIALLY
AROUND KRDG AND KABE TO KPHL. THE WIND IS FORECAST TO BECOME
NORTHEAST TO EAST AROUND 6 TO 10 KNOTS WITH GUSTS TO 15 KT. LOWER
CEILINGS...IN THE MVFR RANGE COULD BEGIN TO FILTER INTO THE REGION
AFTER 18Z.
TUESDAY NIGHT...MVFR TO IFR IN LOW CLOUDS FOG AND SCT SHOWERS.
OUTLOOK...
WEDNESDAY THROUGH WEDNESDAY NIGHT... MVFR TO IFR IN LOW CLOUDS,
FOG AND LIGHT RAIN SHOWERS.
THURSDAY: IMPROVING CONDITIONS TO VFR WITH SOUTH GUSTS OF 15-20
KNOTS.
THURSDAY NIGHT THROUGH FRIDAY NIGHT : VFR DETERIORATING TO MVFR/IFR
DURING THE DAY FRIDAY FROM WEST TO EAST WITH RAIN. SOUTHERLY FLOW
LLWS POSSIBLE JUST AHEAD OF THE FRONTAL PASSAGE FRIDAY NIGHT
BEFORE WINDS SHIFT TO THE NW. IMPROVING CONDITIONS LATE FRIDAY
NIGHT.
SATURDAY: VFR.
&&
.MARINE...
OVERNIGHT...NO SCA HEADLINE. A SOUTH TO SOUTHWEST WIND IS EXPECTED
INTO TONIGHT. WIND SPEEDS SHOULD DIMINISH FROM 10 TO 15 KNOTS INTO
THE 5 TO 10 KNOT RANGE.
TUESDAY...A COLD FRONT IS FORECAST TO PUSH SOUTHWEST THROUGH OUR
REGION. THE WIND WILL BECOME LIGHT AND VARIABLE IN ADVANCE OF THE
FRONT BEFORE SHIFTING TO THE NORTHEAST AND EAST. WIND SPEEDS ARE
EXPECTED TO INCREASE INTO THE 10 TO 15 KNOT RANGE. SCATTERED GUSTS
NEAR 25 KNOTS ARE POSSIBLE ON OUR OCEAN WATERS NORTH OF BARNEGAT
INLET. THE 25 KNOT GUSTS ARE NOT EXPECTED TO BE WIDESPREAD ENOUGH
TO WARRANT A SMALL CRAFT ADVISORY. WAVE HEIGHTS ON OUR OCEAN
WATERS SHOULD BUILD NEAR 4 FEET.
TUESDAY NIGHT...NO SCA HEADLINE ANTICIPATED ATTM.
OUTLOOK...
WEDNESDAY THROUGH THURSDAY MORNING: NO SCA HEADLINE ANTICIPATED
ATTM FOR EITHER SEAS OR WINDS.
THURSDAY AFTERNOON THROUGH SATURDAY: SCA CONDITIONS AS SEAS WILL
LIKELY BE OVER FIVE FEET, SCA WIND GUSTS POSSIBLE THURSDAY AND
FRIDAY AFTERNOONS.
&&
.HYDROLOGY...
THE FRONTAL BOUNDARY WILL BE SLOW MOVING ACROSS THE REGION WITH A
FAVORABLE SOUTHEAST FLOW PROVIDING PLENTIFUL ATLANTIC MOISTURE.
HOWEVER THE MAIN RAINFALL AXIS LOOKS PROGRESSIVE ATTM. PW VALUES CLOSE
TO 2 INCHES ALONG THE FRONT WILL CREATE A FAVORABLE ENVIRONMENT FOR
HEAVY SHOWERS AHEAD OF THE COLD FRONT. SMALL STREAM AND URBAN
RUNOFF IS POSSIBLE AS FFG IS BETWEEN 1 AND 2 INCHES FOR A SIX
HOUR PERIOD. RIGHT NOW A GENERAL 1-2 INCHES OF RAIN IS LIKELY WITH
THIS SYSTEM. LOCALLY HIGHER AMOUNTS ARE BEING INDICATED BY SEVERAL
GEFS MEMBERS, FUTURE UPDATES WILL CONTINUE TO HONE IN ON WHERE
THESE MIGHT OCCUR. RIGHT NOW THE TREND IS FOR THE RAIN SHIELD TO
BE MORE INTENSE ACROSS THE WESTERN PARTS OF THE CWA.
&&
.TIDES/COASTAL FLOODING...
TIDES WILL BE ASTRONOMICALLY HIGH DUE TO THE FULL
MOON THIS WEEK. OUR IN HOUSE MODEL SUGGESTS SOME TIDAL DEPARTURES OF
.2-.4 FEET WITH THE HIGH TIDAL CYCLES WHICH COULD RESULT IN SOME
SPOTTY MINOR TIDAL FLOODING. THE MAIN TIDAL CYCLES OF CONCERN ARE
WEDNESDAY AND THURSDAY NIGHTS.
&&
.EQUIPMENT...
DIX 88D OTS UFN...AT LEAST INTO TUESDAY AFTERNOON.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GAINES/DRAG 1103
NEAR TERM...DRAG/IOVINO/JOHNSON 1103
SHORT TERM...IOVINO
LONG TERM...GAINES
AVIATION...DRAG/GAINES/IOVINO/JOHNSON 1103
MARINE...DRAG/GAINES/IOVINO 1103
HYDROLOGY...
TIDES/COASTAL FLOODING...
EQUIPMENT...1103
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
619 AM EDT SUN MAY 11 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN IN CONTROL OF THE REGION THROUGH
TUESDAY...WITH MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS BEING
POSSIBLE. A COLD FRONT WILL MOVE INTO THE AREA ON WEDNESDAY AND
THURSDAY PROVIDING INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN UPPER RIDGE WILL BUILD OVER THE FORECAST AREA TODAY WITH HIGH
PRESSURE OVER THE WESTERN ATLANTIC RIDGING IN AT THE SURFACE.
DESPITE WEAK DYNAMICS...THE SPC WRF AND HRRR ARE IN FAVOR OF
ISOLATED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON HOURS.
MOISTURE APPEARS HIGHEST IN THE SOUTHEASTERN SECTION OF THE
FORECAST AREA. CONTINUED TO INDICATE ONLY A SLIGHT CHANCE OF
AFTERNOON SHOWERS AND THUNDERSTORMS WITH THE BEST CHANCE
SOUTHEAST. ABOVE NORMAL AFTERNOON HIGHS IN THE UPPER 80S WITH
LIGHT SOUTH/SOUTHWESTERLY WINDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
CAN NOT RULE OUT SOME SCATTERED LINGERING RAINFALL ACROSS EASTERN
PORTIONS OF THE CWA EARLY TONIGHT...THEN ALL AREAS DRYING OUT BY
MIDNIGHT. ON MONDAY THE UPPER RIDGE OFF THE ATLANTIC TRIES TO
BUILD WESTWARD BACK ACROSS THE AREA. SURFACE WIND FLOW OFF THE
ATLANTIC WILL CONTINUE TO BRING MOISTURE INTO THE REGION. WITH
AFTERNOON TEMPERATURES FORECAST AROUND 90...CAN NOT RULE OUT
ISOLATED TO SCATTERED AFTERNOON SHOWERS OR STORMS. LIMITING FACTOR
WOULD BE THE LACK OF ANY WELL DEFINED SURFACE FRONT. BEST CHANCE
AT THIS TIME WOULD APPEAR TO BE ACROSS THE EASTERN PORTIONS OF THE
CWA CLOSER TO THE SEA-BREEZE FRONT. ANY ACTIVITY SHOULD DIMINISH
AFTER SUNSET. OVERNIGHT LOWS MONDAY NIGHT REMAIN MILD...WITH
READINGS IN THE MIDDLE 60S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
ONLY MADE MINOR CHANGES IN THE LONGER TERM AT THIS TIME. MODELS IN
GENERAL AGREEMENT EARLY IN THE PERIOD...THEN THE GFS AND ECMWF
DIVERGE ON THE STRENGTH OF A FORECAST UPPER TROUGH BY THE END OF
THE WEEK.
BERMUDA HIGH IN PLACE ON TUESDAY FOR THE REGION...WITH AN UPPER TROUGH
OVER THE MID PART OF THE COUNTRY. ALTHOUGH THE HIGH OFF THE COAST
WILL DOMINATE INTO MID WEEK...INCREASING MOISTURE AND TEMPERATURES
WILL RESULT IN A CHANCE OF A FEW AFTERNOON THUNDERSTORMS TUESDAY.
THE DIURNAL ACTIVITY WILL DIMINISH OVERNIGHT AND THEN THE CHANCE
OF AFTERNOON THUNDERSTORMS INCREASES WEDNESDAY. AS THE NEXT SYSTEM
SLOWLY APPROACHES THE AREA AND MOVES THROUGH ON THURSDAY EXPECT
THE CHANCE OF RAIN TO CONTINUE. HAVE RAISED THE POPS INTO THE
LIKELY CATEGORY FOR THURSDAY...WITH DIMINISHING POPS BEGINNING
THURSDAY EVENING. WILL HAVE TO CONTINUE TO WATCH THE TIMING AND
PROGRESSION OF THE UPPER TROUGH THOUGH. TEMPERATURES AHEAD OF THE
NEXT SYSTEM SHOULD BE ABOVE NORMAL IN THE UPPER 80S TUESDAY AND
WEDNESDAY AND THEN AS CLOUDS AND PRECIPITATION MOVE IN...HIGHS
WILL BE SOMEWHAT COOLER THE REMAINDER OF THE WEEK IN THE UPPER 70S
TO AROUND 80.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE PERIOD. WITH LOW DEW
POINT DEPRESSIONS AND PLENTY OF LOW LEVEL MOISTURE IN PLACE...MVFR
CIGS AND VSBYS ARE POSSIBLE THROUGH 12Z. VFR CONDITIONS EXPECTED
AT ALL TERMINALS BY 14Z WITH LIGHT SOUTHWEST WINDS THROUGH THE
DAY. AN UPPER RIDGE WILL BUILD OVER THE REGION TODAY WHICH SHOULD
LIMIT PRECIPITATION. HOWEVER... SOME MODELS ARE INDICATING
AFTERNOON SHOWERS AND THUNDERSTORMS DEVELOPING. CONFIDENCE IN
TIMING AND COVERAGE IS TOO LOW TO INCLUDE IN CURRENT TAF ISSUANCE.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE WEDNESDAY NIGHT
INTO THURSDAY WITH SHARP UPPER TROUGH APPROACHING THE AREA
RESULTING IN SHOWERS AND THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
337 AM EDT SUN MAY 11 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN IN CONTROL OF THE REGION THROUGH
TUESDAY...WITH MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS BEING
POSSIBLE. A COLD FRONT WILL MOVE INTO THE AREA ON WEDNESDAY AND
THURSDAY PROVIDING INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TODAY/...
EARLY THIS MORNING...REGIONAL RADAR IMAGERY SHOWS ISOLATED SHOWERS
MAINLY ACROSS THE EXTREME EASTERN MIDLANDS THIS MORNING. EXPECT
THE SHOWERS TO CONTINUE MOVING NORTHEASTWARD AND TO DISSIPATE OVER
THE NEXT COUPLE OF HOURS. HAVE ADJUSTED POPS AND CLOUDS THROUGH
THE EARLY MORNING HOURS TO ACCOUNT FOR CURRENT SITUATION.
TEMPERATURES REMAIN ON TRACK FOR LOWER 60S IN THE WESTERN MIDLANDS
AND MIDDLE TO UPPER 60S ELSEWHERE.
TODAY...AN UPPER RIDGE WILL BUILD OVER THE FORECAST AREA TODAY
WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC RIDGING IN AT THE
SURFACE. DESPITE WEAK DYNAMICS...THE SPC WRF AND HRRR ARE IN FAVOR
OF ISOLATED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON HOURS.
MOISTURE APPEARS HIGHEST IN THE SOUTHEASTERN SECTION OF THE
FORECAST AREA. CONTINUED TO INDICATE ONLY A SLIGHT CHANCE OF
AFTERNOON SHOWERS AND THUNDERSTORMS WITH THE BEST CHANCE
SOUTHEAST. ABOVE NORMAL AFTERNOON HIGHS IN THE UPPER 80S WITH
LIGHT SOUTH/SOUTHWESTERLY WINDS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
CAN NOT RULE OUT SOME SCATTERED LINGERING RAINFALL ACROSS EASTERN
PORTIONS OF THE CWA EARLY TONIGHT...THEN ALL AREAS DRYING OUT BY
MIDNIGHT. ON MONDAY THE UPPER RIDGE OFF THE ATLANTIC TRIES TO
BUILD WESTWARD BACK ACROSS THE AREA. SURFACE WIND FLOW OFF THE
ATLANTIC WILL CONTINUE TO BRING MOISTURE INTO THE REGION. WITH
AFTERNOON TEMPERATURES FORECAST AROUND 90...CAN NOT RULE OUT
ISOLATED TO SCATTERED AFTERNOON SHOWERS OR STORMS. LIMITING FACTOR
WOULD BE THE LACK OF ANY WELL DEFINED SURFACE FRONT. BEST CHANCE
AT THIS TIME WOULD APPEAR TO BE ACROSS THE EASTERN PORTIONS OF THE
CWA CLOSER TO THE SEA-BREEZE FRONT. ANY ACTIVITY SHOULD DIMINISH
AFTER SUNSET. OVERNIGHT LOWS MONDAY NIGHT REMAIN MILD...WITH
READINGS IN THE MIDDLE 60S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
ONLY MADE MINOR CHANGES IN THE LONGER TERM AT THIS TIME. MODELS IN
GENERAL AGREEMENT EARLY IN THE PERIOD...THEN THE GFS AND ECMWF
DIVERGE ON THE STRENGTH OF A FORECAST UPPER TROUGH BY THE END OF
THE WEEK.
BERMUDA HIGH IN PLACE ON TUESDAY FOR THE REGION...WITH AN UPPER TROUGH
OVER THE MID PART OF THE COUNTRY. ALTHOUGH THE HIGH OFF THE COAST
WILL DOMINATE INTO MID WEEK...INCREASING MOISTURE AND TEMPERATURES
WILL RESULT IN A CHANCE OF A FEW AFTERNOON THUNDERSTORMS TUESDAY.
THE DIURNAL ACTIVITY WILL DIMINISH OVERNIGHT AND THEN THE CHANCE
OF AFTERNOON THUNDERSTORMS INCREASES WEDNESDAY. AS THE NEXT SYSTEM
SLOWLY APPROACHES THE AREA AND MOVES THROUGH ON THURSDAY EXPECT
THE CHANCE OF RAIN TO CONTINUE. HAVE RAISED THE POPS INTO THE
LIKELY CATEGORY FOR THURSDAY...WITH DIMINISHING POPS BEGINNING
THURSDAY EVENING. WILL HAVE TO CONTINUE TO WATCH THE TIMING AND
PROGRESSION OF THE UPPER TROUGH THOUGH. TEMPERATURES AHEAD OF THE
NEXT SYSTEM SHOULD BE ABOVE NORMAL IN THE UPPER 80S TUESDAY AND
WEDNESDAY AND THEN AS CLOUDS AND PRECIPITATION MOVE IN...HIGHS
WILL BE SOMEWHAT COOLER THE REMAINDER OF THE WEEK IN THE UPPER 70S
TO AROUND 80.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE PERIOD AT CAE/CUB/DNL.
WITH LOW DEW POINT DEPRESSIONS AND PLENTY OF LOW LEVEL MOISTURE IN
PLACE THINK AGS/OGB COULD HAVE MVFR VSBYS 08Z-12Z WITH POSSIBLE
TEMPORARY IFR VSBYS AND/OR CIGS. MODEL GUIDANCE HAS NOT BEEN
AGGRESSIVE WITH FOG DEVELOPMENT. HOWEVER...GIVEN THE RESTRICTIONS
THAT OCCURRED YESTERDAY MORNING AND THAT SEVERAL STATIONS UPSTREAM
ARE INDICATING REDUCED VISIBILITIES ALREADY...CONFIDENCE IS
INCREASED.
VFR CONDITIONS EXPECTED AT ALL TERMINALS BY 14Z WITH LIGHT
SOUTHWEST WINDS THROUGH THE DAY. AN UPPER RIDGE WILL BUILD OVER
THE REGION TODAY WHICH SHOULD LIMIT PRECIPITATION. HOWEVER... SOME
MODELS ARE INDICATING AFTERNOON SHOWERS AND THUNDERSTORMS
DEVELOPING. CONFIDENCE IN TIMING AND COVERAGE IS TOO LOW TO
INCLUDE IN CURRENT TAF ISSUANCE.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE WEDNESDAY NIGHT
INTO THURSDAY WITH SHARP UPPER TROUGH APPROACHING THE AREA
RESULTING IN SHOWERS AND THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
227 AM EDT SUN MAY 11 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN IN CONTROL OF THE REGION THROUGH
TUESDAY. A COLD FRONT WILL MOVE INTO THE AREA ON WEDNESDAY AND
THURSDAY PROVIDING INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
REGIONAL RADAR IMAGERY SHOWS WIDELY SCATTERED SHOWERS MAINLY
ACROSS THE SOUTHEASTERN MIDLANDS THIS MORNING. EXPECT THE SHOWERS
TO CONTINUE MOVING NORTHEASTWARD AND TO DISSIPATE OVER THE NEXT
COUPLE OF HOURS. HAVE ADJUSTED POPS AND CLOUDS THROUGH THE EARLY
MORNING HOURS TO ACCOUNT FOR CURRENT SITUATION. TEMPERATURES
REMAIN ON TRACK FOR LOWER 60S IN THE WESTERN MIDLANDS AND MIDDLE
TO UPPER 60S ELSEWHERE.
AN UPPER RIDGE WILL BUILD OVER THE FORECAST AREA TODAY WITH HIGH
PRESSURE OVER THE WESTERN ATLANTIC RIDGING IN AT THE SURFACE.
DESPITE WEAK DYNAMICS...THE SPC WRF AND HRRR ARE IN FAVOR OF
ISOLATED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON HOURS.
MOISTURE APPEARS HIGHEST IN THE SOUTHEASTERN SECTION OF THE
FORECAST AREA. CONTINUED TO INDICATE ONLY A SLIGHT CHANCE OF
AFTERNOON SHOWERS AND THUNDERSTORMS WITH THE BEST CHANCE SOUTHEAST.
ABOVE NORMAL AFTERNOON HIGHS IN THE UPPER 80S WITH LIGHT
SOUTH/SOUTHWESTERLY WINDS.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
THE GFS AND ESPECIALLY THE NAM SHOW MORE MOISTURE LINGERING MAINLY
IN THE SOUTHEAST SECTION THROUGH MONDAY NIGHT. A WELL-DEFINED
SURFACE FEATURE APPEARS TO BE LACKING. ALOFT...THE MODELS SHOW
RISING H5 HEIGHT. WE USED THE LOWER GUIDANCE POPS. BELIEVE ANY
SHOWERS AND THUNDERSTORMS WILL BE ISOLATED AND MAINLY TIED TO
HEATING. KEPT HIGHS SLIGHTLY HIGHER THAN THE MOS GUIDANCE GIVEN
RECENT VERIFICATION...UPPER RIDGING...AND THE DRY ENVIRONMENTAL
CONDITIONS. USED THE MOS CONSENSUS FOR THE LOW TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS IN GENERAL AGREEMENT ON TUESDAY WITH BERMUDA HIGH IN PLACE
FOR THE SE US AND AN UPPER TROUGH OVER THE MID PART OF THE COUNTRY.
THE PROGRESSION EASTWARD OF THE UPPER TROUGH HAS SLOWED IN LATEST
MODEL RUNS. WHILE THE HIGH OFF THE COAST WILL DOMINATE INTO MID
WEEK...INCREASING MOISTURE AND TEMPERATURES WILL RESULT IN A CHANCE
OF A FEW AFTERNOON THUNDERSTORMS TUESDAY. THE DIURNAL ACTIVITY WILL
DIMINISH OVERNIGHT AND THEN THE CHANCE OF AFTERNOON THUNDERSTORMS
INCREASES WEDNESDAY. AS THE NEXT SYSTEM SLOWLY APPROACHES THE AREA
AND MOVES THROUGH ON THURSDAY EXPECT THE CHANCE OF RAIN TO CONTINUE
AND ATTM EXPECT THE HIGHEST CHANCE TO BE THURSDAY
AFTERNOON/EVENING. WILL HAVE TO CONTINUE TO WATCH THE TIMING AND
PROGRESSION OF THE UPPER TROUGH. TEMPERATURES AHEAD OF THE NEXT
SYSTEM SHOULD BE ABOVE NORMAL IN THE UPPER 80S TUESDAY AND
WEDNESDAY AND THEN AS CLOUDS AND PRECIPITATION MOVE IN...HIGHS
WILL BE SOMEWHAT COOLER THE REMAINDER OF THE WEEK IN THE UPPER 70S
TO AROUND 80.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE PERIOD AT CAE/CUB/DNL.
WITH LOW DEW POINT DEPRESSIONS AND PLENTY OF LOW LEVEL MOISTURE IN
PLACE THINK AGS/OGB COULD HAVE MVFR VSBYS 08Z-12Z WITH POSSIBLE
TEMPORARY IFR VSBYS AND/OR CIGS. MODEL GUIDANCE HAS NOT BEEN
AGGRESSIVE WITH FOG DEVELOPMENT. HOWEVER...GIVEN THE RESTRICTIONS
THAT OCCURRED YESTERDAY MORNING AND THAT SEVERAL STATIONS UPSTREAM
ARE INDICATING REDUCED VISIBILITIES ALREADY...CONFIDENCE IS
INCREASED.
VFR CONDITIONS EXPECTED AT ALL TERMINALS BY 14Z WITH LIGHT
SOUTHWEST WINDS THROUGH THE DAY. AN UPPER RIDGE WILL BUILD OVER
THE REGION TODAY WHICH SHOULD LIMIT PRECIPITATION. HOWEVER... SOME
MODELS ARE INDICATING AFTERNOON SHOWERS AND THUNDERSTORMS
DEVELOPING. CONFIDENCE IN TIMING AND COVERAGE IS TOO LOW TO
INCLUDE IN CURRENT TAF ISSUANCE.
.EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE WEDNESDAY NIGHT
INTO THURSDAY WITH SHARP UPPER TROUGH APPROACHING THE AREA
RESULTING IN SHOWERS AND THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS POCATELLO ID
150 PM MDT SUN MAY 11 2014
.SHORT TERM...TONIGHT THROUGH WEDNESDAY. AN UPPER LOW CONTINUED TO
SHIFT SE OF THE REGION TODAY AS A RIDGE OF HIGH PRESSURE AMPLIFIED
ALONG THE PAC COAST. A WEAK DISTURBANCE EMBEDDED IN THE NW FLOW
ALOFT WAS NOTED DIGGING SE ALONG THE DIVIDE AND WILL PROVIDE THE
NECESSARY LIFT FOR AFTERNOON CONVECTION ALONG THE MONTANA AND
WYOMING DIVIDE REGIONS TODAY AND MONDAY. OTHERWISE DRY CONDITIONS
WILL OVERSPREAD THE REGION MONDAY/TUESDAY AS THE RIDGE MIGRATES INTO
THE COAST. A WEAK DISTURBANCE TOPPING THE RIDGE WILL DIG SE ALONG
THE DIVIDE WEDNESDAY AFTERNOON PROVIDING A SLIGHT CHANCE OF
AFTERNOON SHOWERS NEAR ISLAND PARK. A STRONG NORTHERLY SURFACE
PRESSURE GRADIENT WAS POSITIONED OVER THE REGION TODAY...PRODUCING
STRONG NORTH WINDS THROUGHOUT THE SNAKE RIVER PLAIN. MODELS INDICATE
THAT AS THE GRADIENT WEAKENS TONIGHT AND MONDAY...THE WINDS WILL
BEGIN TO WEAKEN. STILL...A LAKE WIND ADVISORY REMAINS IN EFFECT FOR
AMERICAN FALLS THIS AFTERNOON/EVE AND HAVE ADDED A WIND ADVISORY
THROUGH EARLY EVENING FOR THE UPPER SNAKE PLAIN DUE TO THE
PERSISTENT STRENGTH OF THE WINDS IN THAT REGION. IT ALSO LOOKS AS IF
THE NORTH WINDS WILL BE STRONG ENOUGH AGAIN MONDAY...ALBEIT MUCH
WEAKER THAN TODAY...TO SUPPORT YET ANOTHER LAKE WIND ADVISORY FOR
AMERICAN FALLS. CLEARING SKIES WILL ONCE AGAIN SUPPORT FREEZING
TEMPERATURES TONIGHT AND MONDAY NIGHT. ALTHOUGH THE MODEST NORTH
WINDS EXPECTED TONIGHT SHOULD MODERATE THE POTENTIAL COOLING...THUS
HAVE CONVERTED THE FREEZE WATCH TO A FROST ADVISORY FOR ZONES 20 AND
21 FOR TONIGHT.
LIGHT WINDS AND CLEAR SKIES TUESDAY MORNING SHOULD BE VERY
SUPPORTIVE OF A HARD FREEZE IN THE UPPER VALLEY AND FROST IN THE
LOWER SNAKE RIVER PLAIN AND ERN MAGIC VALLEY. THUS HAVE ISSUED A
WATCH FOR THAT TIME FRAME. HUSTON
.LONG TERM...WED NIGHT THROUGH NEXT SUN NIGHT. 500MB LONG WAVE
INDICATES A SHIFT FROM A WEAK TROUGH TO ZONAL FLOW OCCURRING EARLY
WITH ZONAL FLOW CONTINUING TO THE END. THIS WILL MEAN A SHORT-WAVE
DOMINATED WEATHER PATTERN AND THUS VERY LITTLE CONSISTENCY WITH
PREVIOUS GUIDANCE RUNS AND POTENTIALLY STRONG DIFFERENCES AMONG
MODEL SOLUTIONS. COMPARED TO YESTERDAY...THE GFS AND ECMWF HAVE
BROUGHT IN MORE MOISTURE AND PRECIPITATION WITH SLIGHTLY COLDER
TEMPERATURES. SO HAVE TRENDED IN THIS DIRECTION. 500MB HEIGHTS ARE
NOT QUITE AS INTENSE AND THE UPPER LEVEL RIDGE IS WEAKER IN
AMPLITUDE. ON SAT NIGHT/SUN...THE GFS IS BRINGING IN A TROUGH...AT
LEAST TO THE NORTHERN END OF THE FORECAST AREA. THE ECMWF PERFORMS
SIMILARLY...SO HAVE BEEFED UP POPS AND CLOUD COVER AND HAVE THE
STRONGEST WINDS DURING THE PERIOD ON THIS DAY. OTHERWISE WINDS ARE
INDICATING GUSTY WINDS OVER THE ARCO DESERT QUITE WELL. MESSICK
&&
.AVIATION...NORTH WIND IN HRRR INDICATES STRONGER WIND LASTING INTO
THE EVENING...SO HAVE DELAYED THE DECREASE UNTIL LATER TONIGHT.
NORTH WIND SHOULD EVEN REACH THE EASTERN MAGIC VALLEY DURING THE
AFTERNOON. OTHERWISE CIG AND VSBY SHOULD BE EXCELLENT VFR WITH A CIG
POSSIBLE IN THE MID-LEVELS WHERE THE NORTH WIND MEANS UPSLOPE
CONDITIONS...AT KBYI AND KPIH. THIS IS DUE TO A SLOWLY DEPARTING LOW
THAT IS TRACKING THROUGH UT AND SOUTHERN WY/NORTHERN CO. MESSICK
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING AND AGAIN MONDAY FROM
9 AM TO 9 PM MDT FOR IDZ021.
WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR IDZ020.
FROST ADVISORY LATE TONIGHT THROUGH MONDAY MORNING FOR IDZ020-021.
FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING
IDZ017-020-021.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1000 PM CDT MON MAY 12 2014
.MESOSCALE DISCUSSION...
525 PM CDT
STORMS CONTINUE TO REGENERATE ACROSS SOUTHERN WISCONSIN AND OVER
THE STATE BORDER ALONG AND NEAR AN OLD OUTFLOW BOUNDARY. THIS
BOUNDARY WHICH HAS MEANDERED ITS WAY INTO LAKE COUNTY ILLINOIS
WILL CONTINUE TO ACT AS AN IMPETUS FOR STORM DEVELOPMENT INTO THIS
EVE. OUTFLOWS FROM THESE STORMS COULD SERVE AS FOCI FOR
DEVELOPMENT IN FAR NORTHERN IL. STORM INTERACTION WITH BOUNDARIES
IN FAR SOUTHERN WI HAS ALLOWED SOME OF THEM TO HAVE BRIEF LOW-
LEVEL ROTATION THREATS. GIVEN THE PRIMARY BOUNDARY PLACEMENT
MAINLY NORTH OF THE IL/WI LINE THIS SHOULDNT BE A CONCERN IN FAR
NORTHERN ILLINOIS OUTSIDE OF MAINLY LAKE COUNTY IL.
FURTHER SOUTH...AN AXIS OF CONVERGENCE...LIKELY PARTIALLY DUE TO
OLD OUTFLOW BOUNDARY FROM MORNING MCS IN EASTERN IA...HAS HAD
TOWERING CUMULUS AND SOME STORM DEVELOPMENT. GIVEN HIGH
INSTABILITY WITH MLCAPES IN EXCESS OF 2500 J/KG AND HIGH PWATS
OVER THE FORECAST AREA...ANY CELLS COULD SPRING UP QUICKLY AND
PRESENT AT LEAST SOME HAIL/WIND THREATS IN ANY AREA OF THE CWA.
THE GREATER DEEP LAYER SHEAR...IN EXCESS OF 30 KT...LOOKS TO
REMAIN MAINLY OVER THE SEVERE THUNDERSTORM WATCH THROUGH EARLY
EVE. THAT AREA PRESENTS THE GREATEST THREAT FOR WELL-ORGANIZED
STORMS...CAPABLE OF WIND DAMAGE AND TAPPING THE HIGH -10C TO -30C
CAPE FOR SIGNIFICANT HAIL.
THE ELONGATED AREA OF STORMS ALONG AND AHEAD OF THE COLD FRONT
ACROSS SOUTHEAST IA INTO MO SHOULD CONTINUE TO ADVANCE EASTWARD
HOLDING THEIR OWN THESE NEXT FEW HOURS. THESE ARE TIMED TO REACH
NORTH CENTRAL IL AROUND 8 PM-9 PM. THE ORIENTATION OF THE DEEP
LAYER SHEAR VECTORS IN THIS AREA DO NOT FAVOR ANY TYPE OF
EXTENSIVE MCS...THOUGH INDIVIDUAL MULTICELL CLUSTERS CAPABLE OF
DAMAGING WINDS ARE POSSIBLE AS FAR EAST AS NORTH CENTRAL IL THIS
EVE.
MTF
&&
.DISCUSSION...
244 PM...MULTIPLE FORECAST CONCERNS AND CHALLENGES THROUGH THE
PERIOD INCLUDING THUNDERSTORM COVERAGE/TIMING THROUGH TUESDAY
AFTERNOON ALONG WITH SEVERE/HEAVY RAIN POTENTIAL. THEN TURNING
MUCH COLDER MIDWEEK WITH A PERIOD OF SHOWERS/RAIN FROM WEDNESDAY
EVENING INTO THURSDAY.
CONVECTIVE TRENDS OVER THE NEXT FEW HOURS DISCUSSED IN THE
ABOVE/RECENT MESOSCALE DISCUSSION WITH ATTENTION NOW SHIFTING TO
THUNDERSTORMS EXTENDING FROM CENTRAL IOWA SOUTH TO TEXAS...AHEAD
OF THE SLOWLY ADVANCING COLD FRONT. SHORT TERM GUIDANCE CONTINUES TO
SHOW ADDITIONAL ACTIVITY DEVELOPING AHEAD OF THE CURRENT LINE AS IT
ALL SLOWLY SHIFTS EAST...WHICH WOULD BRING ACTIVITY INTO THE WESTERN
CWA AS SOON AS 23Z-00Z. SEVERE POTENTIAL WOULD BE HIGHEST EARLIER
WITH BETTER INSTABILITY BEFORE LOST OF DAYTIME HEATING...THOUGH
TEMPS WILL ONLY SLOWLY DROP THROUGH THE 70S THIS EVENING. AS NOTED
IN THE PREVIOUS DISCUSSION...DO ANTICIPATE ANOTHER WATCH LATER THIS
EVENING BUT HOW FAR EAST AND COVERAGE OF SEVERE POTENTIAL WILL BE
TIED TO TIMING. MAIN THREATS WOULD CONTINUE TO BE LARGE HAIL AND
DAMAGING WIND GUSTS.
PRECIPITABLE WATER VALUES INCREASE TO 1.5 INCHES AND EVEN A BIT
HIGHER TONIGHT AND COMBINED WITH DEWPOINTS IN THE UPPER 60S AND
EVEN A FEW LOWER 70S...HEAVY RAIN IS LIKELY. WHILE THE INDIVIDUAL
STORMS WILL BE MOVING NORTHEAST FAIRLY QUICKLY...THE ENTIRE FRONTAL
PROGRESSION EASTWARD WILL BE RELATIVELY SLOW THUS HEAVY RAIN OVER
THE SAME AREAS COULD RESULT IN SOME FLOODING POTENTIAL. AND WITH THE
HEAVY RAINS IN PARTS OF THE AREA SUNDAY EVENING...INCLUDING THE
SOUTHERN SUBURBS AND NORTHWEST INDIANA...ADDITIONAL HEAVY RAIN COULD
LEAD TO LOCALIZED FLASH FLOODING. HOWEVER...CONFIDENCE IS SOMEWHAT
LOW WITH THE POTENTIAL FOR CONVECTION TO THE SOUTHWEST TO MOVE EAST
SOUTH OF THE AREA AND POTENTIALLY CUT OFF STRONGER/HEAVIER PRECIP
ACROSS NORTHERN IL.
PRECIP PROGRESSION EASTWARD WILL LIKELY SLOW TUESDAY MORNING AS IT
SLOWLY ENDS FROM WEST TO EAST BUT COULD CONTINUE INTO THE AFTERNOON
ACROSS NORTHWEST INDIANA. TEMP TRENDS WILL ALSO BE TRICKY AS THEY
WILL LIKELY FALL OR BECOME STEADY ACROSS THE EASTERN HALF WITH
SOME RECOVERY IN THE WEST IN THE AFTERNOON. TEMPS WILL CONTINUE TO
FALL INTO THE MID/UPPER 40S FOR LOWS BY WEDNESDAY MORNING AND
WHILE THESE ARE CLOSE TO NORMAL FOR MID MAY...IT WILL LIKELY FEEL
MUCH COLDER GIVEN THE CURRENT TEMPS AND DEWPOINTS.
AS THE UPPER TROUGH DIGS ACROSS THE CENTRAL AND SOUTHERN PLAINS
WEDNESDAY INTO WEDNESDAY NIGHT...NEW LOW PRESSURE WILL DEVELOP OVER
THE OHIO VALLEY AND LIFT NORTHEAST ACROSS THE CENTRAL OR EASTERN
GREAT LAKES REGION ON THURSDAY. WHILE CONFIDENCE IS INCREASING IN
THE OVERALL TRENDS WITH THIS SYSTEM...ITS EXACT TRACK COULD STILL
HAVE LARGE IMPACTS ON THE SPECIFICS OF THE FORECAST. FIRST...THERE
WILL PROBABLY BE A SHARP PRECIP GRADIENT ON THE NORTHWEST SIDE OF
THIS SYSTEM...WHICH WILL LIKELY BE ACROSS THE WESTERN CWA. THE
CLOSER THE LOW TRACKS TO THE AREA...THE STRONGER THE NORTHERLY WINDS
WILL BE...ESPECIALLY ACROSS THE EASTERN CWA. BUT AS CLOUDS AND
SHOWERS SPREAD NORTH WEDNESDAY WITH A RATHER COLD/WET WEDNESDAY
NIGHT/THURSDAY MORNING. HIGHS WEDNESDAY AND THURSDAY LIKELY ONLY
IN THE 50S...THOUGH ANY SUNSHINE ESPECIALLY WESTERN AREAS COULD
PUSH TEMPS INTO THE 60S.
AS AN UPPER LOW DEVELOPS ACROSS THE NORTHERN LAKES REGION THURSDAY
AND SLOWLY DRIFTS EAST THIS WEEKEND...WEAK IMPULSES COULD HELP
TRIGGER AFTERNOON SHOWERS ON FRIDAY AND PERHAPS AGAIN ON SATURDAY
THOUGH COVERAGE SHOULD BE MAINLY ISOLATED. TEMPERATURES WILL START
A SLOW WARMING TREND THROUGH THE 60S THIS WEEKEND AND PERHAPS
BACK INTO THE 70S EARLY NEXT WEEK. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* LINE OF THUNDERSTORMS FOLLOWED BY AN AREA OF RAIN.
* DURATION OF THUNDERSTORMS AT TERMINALS...AND IMPACTS ON CIGS/VIS.
* TIMING OF COLD FRONT PASSAGE AND ASSOCIATED WIND SHIFT FROM SLY
TO WLY.
* DURATION OF MVFR CIGS FOLLOWING THE FROPA.
KREIN
//DISCUSSION...UPDATED 00Z...
THE AREA IS IN A WARM...MOIST...UNSTABLE WARM SECTOR AHEAD OF A
STRONG COLD FRONT MOVING THROUGH IOWA AND MISSOURI. SCATTERED
THUNDERSTORMS HAVE BECOME MORE FREQUENT AS HIGH LEVEL CLOUDINESS
HAS CLEARED...ALLOWING MORE DIRECT SUNSHINE. HAVE ADDED A TEMPO
GROUP TO THE INITIAL COUPLE HOURS FOR THE INCREASED FREQUENCY OF
WARM SECTOR THUNDERSTORMS. MORE ORGANIZED AND PERSISTENT THUNDER
AND PCPN WILL OCCUR ALONG AND JUST AHEAD OF THE STRONG COLD FRONT
APPROACHING THE AREA. NOT ONLY WILL THIS FRONT BRING PREVAILING
SHOWERS AND SCATTERED TS...WINDS WILL QUICKLY SHIFT FROM SLY TO
SWLY-WLY...WITH A PERIOD OF LINGERING SHOWERS AND MVFR CIGS.
ANTICIPATE THAT MVFR CIGS SHOULD HANG IN FOR MUCH OF THE DAY
TOMORROW UNDER PERSISTENT COLD ADVECTION AND CYCLONIC FLOW ALOFT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM CONFIDENCE IN WIND TRENDS.
* MEDIUM TO HIGH CONFIDENCE IN PERIODS OF SHRA/TSRA IMPACTING THE
TERMINALS...BUT LOW CONFIDENCE IN TIMING AND DURATION.
* MEDIUM CONFIDENCE IN CIG/WIND TRENDS TOMORROW.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...RAIN LIKELY. MVFR CIGS/VIS POSSIBLE.
THURSDAY...CHANCE OF SHRA.
FRIDAY...CHANCE OF SHRA.
SATURDAY...VFR. WX NIL.
SUNDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
320 PM CDT
AREAS OF DENSE FOG CONTINUE TO PERSIST LATE THIS AFTERNOON ACROSS
NORTHERN LAKE MICHIGAN PER SHIP OBS AND SURROUNDING SFC COASTAL
OBS NORTH OF THE WARM FRONT DRAPED WEST TO EAST ACROSS THE MIDDLE
PART OF THE LAKE. THIS WARM FRONT EXTENDS BACK WEST TO LOW
PRESSURE OVER E CENTRAL MN / NORTHWEST WI WHICH WILL CONTINUE TO
MOVE NORTHEAST TONIGHT. THIS FRONTAL BOUNDARY WILL CONTINUE TO BE
A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT TONIGHT AS WELL. A
COLD FRONT ASSOCIATED WITH THE LOW WILL SWEEP WEST TO EAST ACROSS
THE LAKE AROUND DAYBREAK TUESDAY SWEEPING OUT THE FOG AND
BRINGING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
MORNING TUESDAY.
WINDS OCCASIONALLY EXCEEDING SMALL CRAFT ADVISORY THRESHOLDS WILL
CONTINUE INTO THIS EVENING ALONG THE ILLINOIS AND INDIANA
SHORELINES. ONGOING CONVECTION HAS DISRUPTED THE WIND FIELD
CAUSING AN ONSHORE LAKE BREEZE ESPECIALLY FARTHER NORTH CLOSER TO
THE OUTFLOW FROM EARLIER THUNDERSTORMS ACROSS WISCONSIN AND
CENTRAL LAKE MICHIGAN. AS THE SOUTHERLY GRADIENT REESTABLISHES
ITSELF... NEW SCATTERED THUNDERSTORMS MAY ALSO CAUSE HIGHER WINDS AND
WAVES INTO THE EVENING THROUGHOUT THE NEAR SHORE WATERS.
ED F
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 3 AM TUESDAY.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
853 PM CDT Mon May 12 2014
.DISCUSSION...
ISSUED 850 PM CDT Mon May 12 2014
Updating forecast tonight to address convection chances as band of
showers and thunderstorms moving ne toward the IL river at mid
evening, spreads into eastern IL overnight and Tue morning as it
weakens. Isolated strong to severe storms possible next hour or
two nw of the IL river but main severe wx threat has shifted into
far northern IL near the WI border near warm front. SPC has
trimmed slight risk of severe storms this evening to areas from
Peoria north, including Peoria, Woodford, Knox, Stark and Marshall
counties. 1005 mb low pressure along the SE MN and WI border has
a cold front extending southward through eastern IA into central
MO and nw AR. Moist and unstable airmass over IL with dewpoints of
65 to 70F with breezy south winds. Leading edge of showers and
thunderstorms was between Galesburg and Peoria to near
Jacksonville and west of St Louis metro. Cold front to track east
to near I-57 by 12Z/7 am Tue. Forecast lows look on track tonight.
Mild lows in the mid to upper 60s over eastern IL ahead of cold
front tonight while cooler mid to upper 50s behind the cold front
over the IL river valley.
07
&&
.AVIATION...
ISSUED 615 PM CDT Mon May 12 2014
Coverage of convection tonight and affect on ceilings the main
forecast concern. Cold front analyzed west of I-35 late this
afternoon and forecast to push into our area after midnight
tonight. Convection expected to increase in coverage this
evening across the west and then start to affect our western
TAF sites (PIA, SPI) from 00z-03z and from 03z to 06z for
the remainder of our locations (BMI, DEC and CMI). Looks as
if SPI and PIA will see the cigs drop to MVFR cat at times
with some of the heavier showers and then become MVFR into
the morning hours, with points east seeing the deterioration
later this evening, probably after 05z. Frontal timing looks
to range from 08-10z at PIA and SPI, 10z-12z DEC and BMI and
by 15z at CMI. Winds ahead of the front tonight will be out
of the south at 10 to 15 kts with some higher gusts possible
in and near and storms that approach a terminal site, and
then winds will veer into the west and northwest after FROPA
with speeds ranging from 10 to 15 kts on Tuesday.
Smith
&&
.PREV DISCUSSION...
ISSUED 252 PM CDT Mon May 12 2014
Warm and rather humid day across the forecast area today, with dew
points in the upper 60s to around 70 degrees and temperatures
mostly in the 80s. Air mass over our area is uncapped and CAPE`s
are from 3500-4000 J/kg in central Illinois, but so far convection
in our CWA has been spotty. More widespread showers/storms have
been occurring across the Ohio Valley. Main action has been
filling in across Iowa and the northwest half of Missouri, along a
cold front.
SHORT TERM...Tonight through Thursday:
Initial forecast concern is on the severe weather potential the
next several hours. The individual storms to our west have been
moving northeast with the overall area only slowly shifting
eastward. The HRRR and NMM high-resolution models have that
particular band of storms reaching the Illinois River around 6 to
7 pm and the I-55 corridor around 9 to 10 pm. Surface observations
over the area are not showing any meaningful boundary currently
present, thus the popcorn nature of the showers/storms so far.
Infrared and water vapor imagery showing some anti-cyclonic motion
over our CWA, which could be causing enough sinking of the air to
keep the showers under control so far. 0-6km shear values expected
to remain rather modest in most areas, so am thinking that the
storms will remain rather disorganized but briefly severe until
the main line gets here. Loss of daytime heating should weaken the
line of storms somewhat as it moves through tonight, but CAPE`s
remain 1000-2000 J/kg ahead of the front so there will still be
some instability to work with.
Morning model runs have the front roughly along the Indiana border
by midday, with threat of thunder diminishing from west to east
through the day. Have kept the dry weather west of I-55 for the
afternoon with likely PoP`s across east central and southeast
Illinois continuing in the afternoon. Temperatures across the east
will be slowly falling in the afternoon behind the front.
Long-advertised phasing of upper troughs in the north central and
southwest U.S. will try to take place the next couple days, although
the models keep them somewhat distinct through mid week.
Development of a surface low will take place Tuesday night across
the lower Mississippi Valley, and this low will be ejected
northeast on the nose of a developing 90-110 knot jet. Dry
northeast flow will erode the northern fringes of the rain shield
some, so will continue to focus the higher PoP`s on Wednesday
across the southeast half of the forecast area. As the surface low
moves northeast, a large upper low will develop over the upper
Mississippi Valley, so the threat of showers will continue even
after the main precipitation shield exits. High temperatures both
Wednesday and Thursday only expected to be in the upper 50s to
around 60 most areas due to the cooler air aloft and the rain.
LONG TERM...Friday through Monday:
The cool and showery weather will continue into Friday, before the
upper low starts to lift into Ontario and the upper pattern over
the U.S. flattens out somewhat. A fast moving wave in the upper
flow tracks an area of rain southeast later in the weekend, with
the ECMWF model about 12-18 hours faster and a bit further north.
Have limited PoP`s on Saturday night and Sunday to slight chances
across the south half of the forecast area, but this may need to
be bumped up if these trends persist on the next couple model
runs. A more substantial warming trend will occur early next week,
as ridging occurs across the Plains.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
302 PM CDT SUN MAY 11 2014
.UPDATE...
300 PM CDT
SEVERE THUNDERSTORM WATCH WILL BE COMING OUT SHORTLY FOR MUCH OF
THE ILLINOIS FORECAST AREA INCLUDING CHICAGO. STORM GROWTH WILL
CONTINUE EASTWARD ACROSS THE AREA WITH POTENTIAL DEVELOPMENT
ACROSS WEST CENTRAL ILLINOIS IN THE NEXT 1-2 HRS. SHORT TERM MESO
DISCUSSION TO BE ISSUED SHORTLY.
.DISCUSSION...
300 PM CDT
FORECAST CONCERNS ARE MAINLY ON THE IMMEDIATE SEVERE WEATHER
CHANCES THROUGH EARLY/MID EVENING. ALSO FOCUS ON THE SEVERE
WEATHER POTENTIAL ON MONDAY...PRIMARILY MONDAY LATE AFTERNOON INTO
THE NIGHTTIME PERIOD.
OVERNIGHT INTO MONDAY MORNING...
STRONG UPPER JET WILL PROPAGATE AROUND THE UPPER TROUGH LATE
TONIGHT INTO THE MORNING ON MONDAY AND WITH THAT LEAD TO FURTHER
AMPLIFYING OF THE UPSTREAM RIDGE...INCLUDING BUILDING HEIGHTS
ACROSS MUCH OF THE FORECAST AREA. MUCH OF THE FORCING FOR
RAIN/STORMS IN THIS PERIOD WOULD BE FOCUSED TO THE WEST AND NORTH
IN SUCH A PATTERN. THE STRONG LOW-LEVEL JET WILL AT LEAST IN PART
BE OVER THE AREA...HOWEVER THE NOSE OF IT WILL BE POINTED FURTHER
NORTH. CONVECTIVE CHANCES LOOK MINIMAL AND MAINLY THE NORTHWEST
FORECAST AREA TOWARD ROCKFORD. CHANCES MAY BE INCREASED SOMEWHAT
IF ANY ORGANIZED CONVECTION FROM THE CENTRAL PLAINS WERE TO
PROPAGATE EASTWARD INTO NORTHERN IL...BUT THE GRADUALLY MORE
MERIDIONAL FLOW AND ORIENTATION OF FORECAST CORFIDI VECTORS WOULD
PUSH MUCH OF THE CONVECTION NORTH OF THE AREA. LOW TEMPS WILL BE
BALMY WITH CONTINUED SOUTHERLY FLOW AND HIGH DEW POINT AIR...WITH
SOME PLACES EXPERIENCING SOME WARMING OF TEMPS LATER THIS
EVENING...ESPECIALLY THOSE IMPACTED BY EARLY EVE CONVECTION AND
THOSE COMMUNITIES NEAR THE LAKE SHORE THAT HAD AFTERNOON/EVE
COOLING.
MONDAY AFTERNOON THROUGH TUESDAY...
THE UPPER TROUGH WILL CONTINUE TO AMPLIFY AS THE UPPER JET TO ITS
FRONT AND BACK INTENSITY. A WARM AND MUGGY DAY IS ANTICIPATED
MONDAY. CONVECTIVE INHIBITION ON MONDAY AFTERNOON DOES LOOK TO BE
OVERCOME BUT A FOCUS IS NOT OVERLY EVIDENT IN OUR FORECAST AREA.
GRADUALLY MORE CONVERGENCE AND INCREASING DEEP LAYER MOISTURE AND
UPWARD MOTION IS FORECAST TO MOVE EASTWARD ACROSS MAINLY NORTH
CENTRAL ILLINOIS LATE IN THE DAY INTO EARLY EVE AND EASE ITS WAY
EASTWARD THROUGH THE REMAINDER OF THE NIGHT. THIS LOOKS LIKE A
PERIOD OF STORMS MOVING NORTHEAST WITHIN THE DEEP MOIST PLUME.
THE SEVERE POTENTIAL WOULD SEEM MOST FAVORED WITH THE INITIAL
CONVECTION IN THE LATE AFTERNOON/EVE AND THEN A GENERAL WANING
LATER INTO THE NIGHT.
THE REMAINDER OF THE DISCUSSION TO BE ISSUED SHORTLY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SCATTERED THUNDERSTORMS LATE THIS AFTERNOON AND EVENING.
* LAKE BREEZE TURNING WINDS TO THE E/ESE LATE THIS AFTERNOON OR
EVENING.
BMD
//DISCUSSION...UPDATED 18Z...
COMPLEX WEATHER SITUATION WILL BRING A COUPLE DECENT CHANCES FOR
THUNDERSTORMS THIS FORECAST PERIOD...AS WELL AS CHANGING WIND
CONDITIONS. TODAY LOW PRESSURE IS TAKING SHAPE WITH AN ILL-DEFINED
WARM FRONT LIFTING NORTH ACROSS ILLINOIS. THE NEXT FEW HOURS SHOULD
BE RELATIVELY QUIET AT THE TERMINALS WITH A LIGHT SOUTH WIND AND VFR
CONDITIONS. VERY UNSTABLE CONDITIONS ARE DEVELOPING HOWEVER...AND
ALREADY SEEING SIGNS ON SATELLITE IMAGERY OF DEEPENING CLOUD GROWTH
OVER PORTIONS OF MISSOURI AND IOWA. THE THUNDERSTORMS ALREADY IN
PLACE ACROSS SOUTHERN IOWA ARE EXPECTED TO CONTINUE EAST
TODAY...ALONG WITH NEW DEVELOPMENT AHEAD WHICH WILL THEN LIFT
EAST/NORTHEAST ACROSS THE FORECAST AREA. COVERAGE REMAINS
UNCERTAIN...HOWEVER GIVEN THE RELATIVELY WEAK SYNOPTIC FORCING WOULD
EXPECT IT TO BE SOMEWHAT SCATTERED IN NATURE. ANY THUNDERSTORMS
THAT DO DEVELOP HAVE THE POTENTIAL TO BE STRONG TO SEVERE WITH
HAIL AND VERY GUSTY WINDS. WHILE THERE WILL LIKELY BE TIMING
ADJUSTMENTS AS WE NEAR THE EVENT...STILL FEEL THE BEST TIME FOR
TSRA AT THE TERMINALS WILL BE MID TO LATE THIS AFTERNOON INTO THE
EVENING.
IN ADDITION TO CONCERNS FOR TSRA THIS AFTERNOON...THERE ALSO REMAINS
THE POSSIBILITY OF A WIND SHIFT TO THE EAST DUE TO A LAKE BREEZE.
COASTAL OBS REMAIN SOUTHERLY THIS HOUR SO THERE IS NO SIGN OF
DEVELOPMENT YET...AND WINDS WILL BE OF MARGINAL STRENGTH FOR A LAKE
BREEZE TO MAKE IT ALL THE WAY INLAND TO THE TERMINALS. THIS MEANS
THAT THERE IS LOW CERTAINTY ON THE WIND DIRECTION THIS AFTERNOON.
SEVERAL HIGHER RES MODELS CONTINUE TO BRING IT THROUGH SO WOULD
PREFER TO NOT MAKE ANY SIGNIFICANT CHANGES AT THIS TIME. FURTHER
COMPLICATING MATTERS WILL BE THE POTENTIAL FOR THUNDERSTORMS
DEVELOPING ON ANY LAKE BREEZE THAT DEVELOPS WHICH COULD THEN GET
AN ASSIST FROM OUTFLOWS THAT DEVELOP.
ADDITIONAL THUNDERSTORMS ARE POSSIBLE AGAIN MONDAY AFTERNOON/EVENING
AND AGAIN COULD BE STRONG...BUT CURRENT TIMING PLACES IT BEYOND THE
CURRENT FORECAST PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN SCATTERED TSRA AND TIMING.
* MEDIUM CONFIDENCE IN LAKE BREEZE DEVELOPING...LOW CONFIDENCE IN
TIMING THROUGH TERMINALS.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...PERIODS OF SHRA/TSRA POSSIBLE.
TUESDAY THROUGH SATURDAY...PERIODIC CHANCES OF SHRA.
KJB
&&
.MARINE...
242 PM...LOW PRESSURE OVER KANSAS WILL MOVE NORTHEAST TO LAKE
SUPERIOR TUESDAY MORNING. AS IT DOES...A WARM FRONT EXTENDING EAST
FROM THE LOW WILL MOVE NORTH ACROSS THE LAKE TONIGHT THROUGH
MONDAY NIGHT...SHIFTING EASTERLY WINDS SOUTHERLY. LOW LEVEL
MOISTURE WILL ALSO BE INCREASING AND AS IT SPREADS ACROSS THE
COOLER LAKE...AREAS OF FOG ARE POSSIBLE AND SOME OF THE FOG MAY
BECOME DENSE. CURRENT WIND SPEEDS ARE FAIRLY LIGHT IN THE 5-15 KT
RANGE AND WILL INCREASE INTO THE 15-25KT RANGE AND REMAIN THERE
UNTIL A COLD FRONT MOVES ACROSS THE LAKE TUESDAY MORNING. THERE IS
A POTENTIAL FOR WINDS TO BE A BIT STRONGER ON MONDAY...ESPECIALLY
WITH THE EASTERLY FLOW NORTH OF THE WARM FRONT ACROSS NORTHERN
LAKE MICHIGAN. THERE REMAINS UNCERTAINTY REGARDING THE POTENTIAL
FOR STRONG NORTHERLY WINDS WEDNESDAY NIGHT INTO THURSDAY AS LOW
PRESSURE DEEPENS MOVING NORTH ACROSS THE GREAT LAKES REGION. THIS
TIME PERIOD WILL NEED TO BE MONITORED FOR HIGHER NORTHERLY WIND
SPEEDS. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
248 PM CDT Sun May 11 2014
.DISCUSSION...
ISSUED 248 PM CDT Sun May 11 2014
Air mass destabilizing quickly across central and southeast
Illinois early this afternoon. 18Z upper air sounding from our
office showing CAPE of around 2600 J/kg with no convective
inhibition, although shear values are not especially impressive.
Latest SPC mesoanalysis indicates CAPE`s are over 3000 J/kg south
of I-72, as dew points of 70 degrees have made it as far north as
Taylorville. Warm front extends from southern Nebraska along the
Iowa/Missouri border, but becomes more diffuse in northern
Illinois where it is more of a dew point discontinuity.
Thunderstorms have been percolating most of the day across the
Ohio Valley, and a persistent, small MCS is advancing across Iowa.
Some development has recently started as well across northeast
Missouri south of the main MCS. Has been quiet in our area the
last few hours, but latest radar returns are starting to show
thunderstorms developing between Taylorville and St Louis.
The primary forecast concern remains with the severe weather
threat over the next 24 to 36 hours.
SHORT TERM...Tonight through Tuesday:
Latest runs of the HRRR have been persistent with the Iowa storms
affecting more of the northern third of Illinois, with more
scattered strong/severe storms affecting our area through about
7 pm. Shear parameters don`t really improve any in our area, so
thinking that hail/wind threat will be the primary concerns here
with the tornado threat closer to the warm front. After sunset,
capping of the atmosphere will begin in the warm sector. Have
maintained some 30-40% PoP`s after midnight northwest of the
Illinois River, and slight chances as far east as I-55, with dry
conditions across the southeast half of the forecast area.
Similar convective parameters expected on Monday, with CAPE`s
rising to 2500-3000 J/kg, although shear remains on the low side.
Day2 slight risk basically along and northwest of the Illinois
River, where the shear will be a bit higher as it is closer to the
incoming cold front, and severe weather threat will mainly be mid
afternoon to early evening. With the front slowing down a tad,
will keep any PoP`s east of I-57 around 20% during the day, while
likely PoP`s around 60% found during the afternoon along/west of
the Illinois River. Have maintained the 60-70% PoP`s everywhere
during the night as the front slowly moves through, and over the
eastern CWA on Tuesday with some 80% values south of I-70 Tuesday.
Severe weather threat on Tuesday appears minimal, and would be
near the Indiana border if any did occur.
LONG TERM...Wednesday through Sunday:
A broad upper trough will be dominating much of the eastern half
of the nation into the first part of the weekend, with cool
conditions prevailing. The ECMWF has been persistent with a closed
upper low forming by late Thursday over the Great Lakes, then
lifting northward, while the GFS keeps a more progressive trough.
Toward the end of the weekend, the trough will finally start to
break down as an upper low digs southward across the Pacific
Northwest, causing rising heights over the center of the nation.
Most challenging area in this forecast period is with rain on
Wednesday. The tail end of the NAM is trending toward the solution
favored by the ECMWF and GEM for the last few days, with a surface
low riding northeast along the base of the trough, although the
NAM is much further west with it. The GFS has keep its surface
features much weaker and further east. Have kept the likely PoP`s
on Wednesday across the southeast third of the area, although the
ECMWF/GEM solutions would likely require this to be expanded
further northwest toward the I-55 corridor. Thursday and Friday,
the rain will be much more scattered in nature, as weak troughs
rotate around through the broad upper trough. Rain chances will
diminish this weekend as the upper flow flattens.
Geelhart
&&
.AVIATION...
ISSUED 1248 PM CDT Sun May 11 2014
Thunderstorms currently over south-central Iowa continue to move
E/NE and will enter northwest Illinois after 20z. Current
trajectory should take most of the storms just north of KPIA, so
will only include VCTS between 22z and 02z. Further southeast,
scattered storms are firing in the warm sector across southern
Illinois. HRRR continues to suggest these cells will spread/develop
northward into east-central Illinois this afternoon. Have
therefore included VCTS at the remaining terminals between 21z and
02z, although KSPI may be missed by convection entirely if trends
hold. Gusty S/SE winds will continue through the afternoon and
will remain in the 10 to 15kt range tonight. Meanwhile, a 45kt
925mb jet will develop across the area overnight, warranting a
low-level wind shear mention at the TAF sites. This momentum will
mix to the surface after sunrise, resulting in gusty S/SW winds
Monday morning.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
242 PM CDT SUN MAY 11 2014
.DISCUSSION...
1030 AM CDT
THE FORECAST FOR THIS AFTERNOON INTO THE EVENING REMAINS
CHALLENGING...ALTHOUGH OBSERVATIONAL TRENDS ARE STARTING TO SHOW
THEMSELVES SLIGHTLY AND THE EFFECT OF EARLY MORNING UPSTREAM
CONVECTION IS BEGINNING TO BE RESOLVED BETTER BY HIGH RESOLUTION
GUIDANCE.
ONGOING CONVECTION ACROSS WESTERN IA/FAR NORTHERN MO IS SLOWLY
EVOLVING EAST. WATER VAPOR AND VISIBLE SATELLITE ALONG WITH
REGIONAL RADAR MOSAIC INDICATE THE PROBABLE PRESENCE OF AN MCV OR
AT LEAST A LOW AMPLITUDE PERTURBATION IN FAR SOUTHWEST IA. WHILE
THIS FEATURE IS UNLIKELY TO RAPIDLY MOVE EAST DUE TO LARGE SCALE
HEIGHT RISES...INCREASING LOW-LEVEL THETA-E ADVECTION AHEAD OF
THIS ON THE SYNOPTIC AND MESO SCALES IS EVIDENT AND FORECAST TO
INCREASE. WITH DIMINISHING INHIBITION...THERE SHOULD CONTINUE AT
LEAST SOME EASTWARD DEVELOPMENT/EVOLUTION OF SCATTERED MAINLY
SUB-SEVERE CONVECTION INTO NORTHERN MO/EASTERN IA/WEST CENTRAL IL
THROUGH EARLY AFTERNOON.
BECAUSE OF THE OVERNIGHT CONVECTION FAR DOWNSTATE IL...THE
SURFACE WARM FRONT REMAINS SOMEWHAT DIFFUSE IN IL...BUT BASED ON
THE CLEAR PLACEMENT OF THE FRONT IN FAR SOUTHERN IA AND
OBSERVATIONAL TRENDS IN IL...IT IS LIKELY TO BE STRENGTHENING
NEAR THE I-74 CORRIDOR THROUGH LATE THIS MORNING AND EVOLVING
INTO THE SOUTHERN AND WESTERN CWA EARLY THIS AFTERNOON. THIS WILL
BASICALLY INTERSECT THE AFOREMENTIONED SCATTERED/REMNANT
CONVECTION AND INCREASE THE LIKELIHOOD OF STORMS BECOMING LOWER-
ROOTED TO OUR WEST OR POTENTIALLY IN OUR WESTERN/SOUTHERN CWA BY
MID-AFTERNOON. MLCAPE STILL LOOKS TO BE ON THE ORDER OF OVER 2000
J/KG WITH FAVORABLE SHEAR PROFILES FOR WELL-ORGANIZED AND POSSIBLY
DISCRETE SUPERCELL STORMS. SO BASICALLY MORE TOWARD SCENARIO 3 IN
THE AFOREMENTIONED AFD LOOKS TO BE THE MOST PROBABLE...AND THE
TYPES OF SEVERE WEATHER FAVORED MENTIONED BEFORE REMAIN THE SAME.
HOWEVER...THE OVERALL CONFIDENCE ON COVERAGE OF STORMS DURING THE
MID AFTERNOON THROUGH MID-EVE REMAINS LOW.
THE MOST FAVORABLE TIME FOR STORMS IN THE CHICAGOLAND AREA
REMAINS LATER AFTERNOON INTO THE EARLY EVE. IT IS POSSIBLE THE
CONVERGENCE OF THE LAKE BREEZE ACROSS EASTERN COOK AND INTO LAKE
COUNTIES IL TRIGGERS SOME ISOLATED CONVECTION PRIOR TO THIS...AND
A COUPLE CONVECTIVE ALLOWING MODELS INDICATE THAT.
HAVE MADE SOME ADJUSTMENTS TO THE TEMPORAL RESOLUTION OF
THUNDERSTORM CHANCES...BUT OVERALL NO MAJOR FORECAST CHANGES.
WILL CONTINUE TO MONITOR OBSERVATIONAL TRENDS...INCLUDING 17Z RAOB
LAUNCHES...AS IT RELATES TO CONVECTIVE CHANCES AND MAGNITUDES IN
THE FORECAST AREA.
MTF
//PREV DISCUSSION...
330 AM CDT
SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON/EARLY EVENING...HEAT
AND HUMIDITY MAKE AN APPEARANCE...THEN TRANSITION TO COLDER
UNSETTLED WEATHER LATER THIS WEEK.
VERY TRICKY FORECAST FOR TODAY...PARTICULARLY IN LIGHT OF MUCH OF
THE SHORT RANGE MODEL GUIDANCE STRUGGLING TO GET A GOOD HANDLE ON
ONGOING CONVECTION. WARM FRONT CURRENTLY LOCATED NEAR THE I-70
CORRIDOR IS BEING CONVECTIVELY ENHANCED BY MCS THAT IS TRACKING
ACROSS DOWNSTATE ILLINOIS...SOMETHING A LOT OF GUIDANCE HAS MISSED
ALTOGETHER. RISING HEIGHTS AND DEVELOPING SURFACE CYCLONE OVER THE
PLAINS SHOULD ALLOW THE WARM FRONT TO MIX NORTH FAIRLY QUICKLY TODAY
AND LIKELY MOVING INTO NORTHERN ILLINOIS THIS AFTERNOON. WARM FRONT
IS EXPECTED TO BECOME BETTER DEFINED THIS AFTERNOON AS CYCLONE OVER
THE PLAINS ORGANIZES WITH INCREASINGLY STRONG PRESSURE FALLS OVER
IOWA LIKELY TO RESULT IN A BACKING OF THE LOW LEVEL WINDS THIS
AFTERNOON...ESPECIALLY NORTH OF THE FRONT AT THE SURFACE.
TO ME THERE LOOKS TO BE 3 MOST PROBABLE POSSIBLE SCENARIOS
CONVECTIVELY TODAY. FIRST...THE LEAST LIKELY SEEMS TO BE THE CAP
HOLDING STRONG AND NO OR ONLY VERY ISOLATED THUNDERSTORMS FORMING. A
SECOND POSSIBLE SCENARIO THAT SEVERAL OF THE CONVECTIVE ALLOWING
MODELS (CAMS) SUGGEST WOULD BE AN MCS ORGANIZING OVER IOWA TOWARD
SUNRISE...THEN MOVING EAST INTO NORTHERN ILLINOIS THIS AFTERNOON.
CONVECTIVE TRENDS CURRENT DON`T SEEM TO FAVOR THIS SCENARIO WITH
STORMS OVER THE EASTERN PLAINS EAST INTO MISSOURI WEAKENING WITH
RENEWED DEVELOPMENT FARTHER WEST OVER NEBRASKA AND KANSAS PRETTY
UNLIKELY TO REACH OUR AREA THIS AFTERNOON. THE FINAL POSSIBLE
SCENARIO...AND THE ONE THAT SEEMS MOST PLAUSIBLE...WOULD BE
SCATTERED THUNDERSTORMS DEVELOPING NEAR THE SHARPENING WARM FRONT
THIS AFTERNOON AS STRONG HEATING ERODES CONVECTIVE INHIBITION.
SEVERE THREAT THIS AFTERNOON/EARLY THIS EVENING WILL OBVIOUSLY BE
DEPENDENT ON HOW CONVECTION EVOLVES. FOR INSTANCE...SCENARIO 2 WITH
THE REMNANT MCS WOULD TEND TO FAVOR A MULTICELL WIND/HAIL THREAT.
SCENARIO 3 IS SOMEWHAT MORE CONCERNING...GIVEN THE SOMEWHAT NEBULOUS
FORCING WOULD EXPECT CONVECTION TO DEVELOP TO BE MORE SCATTERED AND
CELLULAR IN NATURE. THERE ARE CERTAINLY SOME NOTABLE DIFFERENCES IN
THE MODELS WITH RESPECT TO SHEAR PROFILES THIS AFTERNOON...BUT ALL
GUIDANCE SUGGESTS AND VEERING AND SLOWLY INCREASING MID LEVEL
FLOW...WITH BACKING LOW LEVEL AND SURFACE FLOW INCREASING HODOGRAPH
SIZES LATE THIS AFTERNOON. MANY OF THE MODELS ACTUALLY SHOW A VERY
NICE VEERING/INCREASING WIND PROFILE FROM THE SFC-6KM QUITE
FAVORABLE FOR SUPERCELLS. ALSO OF CONCERN IS WIND PROFILES WOULD
FAVOR RIGHT MOVING SUPERCELLS WITH AN EASTERLY MOTION ROUGHLY
PARALLEL TO THE WARM FRONT. FAR MORE UNCERTAINTY EXISTS IN OUR AREA
COMPARED TO POINTS WEST IN THE MODERATE RISK OVER IOWA AND
NEBRASKA...BUT IF CONVECTION OCCURS AND MODE IS FAVORABLE THEN THERE
MAY WELL BE A SEVERAL HOUR LONG WINDOW FAVORABLE CONDITIONS FOR
SUPERCELL(S) WITH A LARGE HAIL AND TORNADO POTENTIAL LOCALLY LATE
THIS AFTERNOON AND EVERY EARLY THIS EVENING.
OTHER FORECAST CONCERNS TODAY INCLUDE CLOUD COVER AND TEMPS. A LOT
OF CLEAR SKIES HERE WEST INTO IOWA REALLY RAISE DOUBTS ABOUT HOW
CLOUDY MUCH OF THE GUIDANCE HAS THINGS TODAY. CONVECTIVE DEBRIS FROM
ACTIVITY OVER MISSOURI COULD LEAD TO SOME CLOUDINESS THIS
MORNING...BUT QUICKLY WARMING CLOUD TOPS ALREADY SUGGEST THAT THIS
MAY NOT BE MUCH OF A FACTOR. ASSUMING WE GET A FAIR AMOUNT OF
SUNSHINE...WHICH SEEMS PRETTY LIKELY...THEN TEMPERATURES COULD
EASILY GET OUT OF HAND. HAVE RAISED HIGHS SEVERAL DEGREES...BUT
WOULD NOT BE SURPRISING TO SEE TEMPS WELL INTO 80S THIS AFTERNOON.
AS CYCLONE DEEPENS AND PRESSURE FALLS INCREASE TO OUR WEST THE
SYNOPTIC GRADIENT IS LIKELY TO BACK MORE SOUTHEASTERLY WHICH SHOULD
ALLOW A LAKE BREEZE TO COME CHARGING WEST INTO NE IL SENDING TEMPS
DROPPING. HIGHER DEWPOINTS WILL PROBABLY STILL BE SOUTH OF THIS AREA
SO MOST LIKELY JUST A RESPECTABLE TEMP DROP AND NOT A LAKE SHORE FOG
PROBLEMS.
WARM FRONT LIKELY TO BLAST NORTH INTO WISCONSIN TONIGHT SENDING
TEMPS SOARING IN THE LAKE COOLED AREAS OF NE IL THIS EVENING AND
ALLOWING TEMPS TO REMAIN UNSEASONABLY WARM ELSEWHERE. FOCUS FOR
CONVECTION TONIGHT SHOULD SHIFT INTO WISCONSIN WITH MAJORITY OF OUR
AREA REMAINING DRY...THOUGH AM RELUCTANT TO REMOVE POPS ALTOGETHER
GIVEN THE INHERENT UNCERTAINTIES DEALING WITH CONVECTIVE EVOLUTION.
MONDAY LOOKS POISED TO BE BREEZY AND UNSEASONABLY WARM AND RATHER
HUMID AS WE RESIDE FIRMLY IN THE WARM SECTOR OF THE CYCLONE. QUICKLY
WARMING TEMPS ALOFT WITH CONTINUED HEIGHT RISES SUGGEST THAT ANY
LEFT OVER CONVECTION SHOULD FADE BEFORE MAKING IT INTO OR VERY FAR
EAST ACROSS OUR CWA MONDAY MORNING. HAVE BUMPED UP TEMPS INTO THE
MID TO UPPER 80S...THOUGH WITH ENOUGH SUNSHINE SOME AREAS COULD
EASILY REACH 90 DEGREES AGAIN GIVEN 850/925MB TEMPS PROGGED TO BE
PRETTY SIMILAR TO WHAT WE SAW THURSDAY. BY AFTERNOON RAIN CHANCES
LOOK SLIM WITH BETTER FORCING WELL WEST OF THE CWA ACROSS IOWA WHERE
STRONG TO SEVERE THUNDERSTORMS ARE LIKELY TO DEVELOP LATE MONDAY
AFTERNOON.
THE LEFT OVERS OF THESE STORMS ARE LIKELY TO MOVE SLOWLY EASTWARD
TOWARD OUR CWA...BUT SHOULDNT ARRIVE UNTIL AFTER DARK AND PROBABLY
WELL AFTER DARK. STABILIZING BOUNDARY LAYER/INCREASING
CINH...MARGINAL SHEAR PROFILES...AND BETTER UPPER FORCING LAGGING TO
THE WEST SUGGEST THAT THE STORMS SHOULD BE IN A WEAKENING PHASE AS
THEY MOVE IN AND THAT LEAVES ME FAR FROM TINGLY ABOUT ANY MEANINGFUL
SEVERE THREAT MONDAY NIGHT.
STILL LOOKS TO BE A MUCH...MUCH COLDER PATTERN SETTING UP FOR THE
MIDDLE AND END OF THE WEEK WITH AN ANOMALOUSLY STRONG UPPER TROUGH
BECOMING ESTABLISHED OVER THE REGION. MEDIUM RANGE MODELS CONTINUE
TO DIFFER SUBSTANTIALLY IN THEIR HANDLING OF THE SMALLER SCALE WAVES
AND SUBSEQUENT BETTER SHOWER CHANCES...SO LEFT WITH LITTLE CHOICE
THAN PERIOD AFTER PERIOD OF SHOWER CHANCES WEDNESDAY ONWARD.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SCATTERED THUNDERSTORMS LATE THIS AFTERNOON AND EVENING.
* LAKE BREEZE TURNING WINDS TO THE E/ESE LATE THIS AFTERNOON OR
EVENING.
BMD
//DISCUSSION...UPDATED 18Z...
COMPLEX WEATHER SITUATION WILL BRING A COUPLE DECENT CHANCES FOR
THUNDERSTORMS THIS FORECAST PERIOD...AS WELL AS CHANGING WIND
CONDITIONS. TODAY LOW PRESSURE IS TAKING SHAPE WITH AN ILL-DEFINED
WARM FRONT LIFTING NORTH ACROSS ILLINOIS. THE NEXT FEW HOURS SHOULD
BE RELATIVELY QUIET AT THE TERMINALS WITH A LIGHT SOUTH WIND AND VFR
CONDITIONS. VERY UNSTABLE CONDITIONS ARE DEVELOPING HOWEVER...AND
ALREADY SEEING SIGNS ON SATELLITE IMAGERY OF DEEPENING CLOUD GROWTH
OVER PORTIONS OF MISSOURI AND IOWA. THE THUNDERSTORMS ALREADY IN
PLACE ACROSS SOUTHERN IOWA ARE EXPECTED TO CONTINUE EAST
TODAY...ALONG WITH NEW DEVELOPMENT AHEAD WHICH WILL THEN LIFT
EAST/NORTHEAST ACROSS THE FORECAST AREA. COVERAGE REMAINS
UNCERTAIN...HOWEVER GIVEN THE RELATIVELY WEAK SYNOPTIC FORCING WOULD
EXPECT IT TO BE SOMEWHAT SCATTERED IN NATURE. ANY THUNDERSTORMS
THAT DO DEVELOP HAVE THE POTENTIAL TO BE STRONG TO SEVERE WITH
HAIL AND VERY GUSTY WINDS. WHILE THERE WILL LIKELY BE TIMING
ADJUSTMENTS AS WE NEAR THE EVENT...STILL FEEL THE BEST TIME FOR
TSRA AT THE TERMINALS WILL BE MID TO LATE THIS AFTERNOON INTO THE
EVENING.
IN ADDITION TO CONCERNS FOR TSRA THIS AFTERNOON...THERE ALSO REMAINS
THE POSSIBILITY OF A WIND SHIFT TO THE EAST DUE TO A LAKE BREEZE.
COASTAL OBS REMAIN SOUTHERLY THIS HOUR SO THERE IS NO SIGN OF
DEVELOPMENT YET...AND WINDS WILL BE OF MARGINAL STRENGTH FOR A LAKE
BREEZE TO MAKE IT ALL THE WAY INLAND TO THE TERMINALS. THIS MEANS
THAT THERE IS LOW CERTAINTY ON THE WIND DIRECTION THIS AFTERNOON.
SEVERAL HIGHER RES MODELS CONTINUE TO BRING IT THROUGH SO WOULD
PREFER TO NOT MAKE ANY SIGNIFICANT CHANGES AT THIS TIME. FURTHER
COMPLICATING MATTERS WILL BE THE POTENTIAL FOR THUNDERSTORMS
DEVELOPING ON ANY LAKE BREEZE THAT DEVELOPS WHICH COULD THEN GET
AN ASSIST FROM OUTFLOWS THAT DEVELOP.
ADDITIONAL THUNDERSTORMS ARE POSSIBLE AGAIN MONDAY AFTERNOON/EVENING
AND AGAIN COULD BE STRONG...BUT CURRENT TIMING PLACES IT BEYOND THE
CURRENT FORECAST PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN SCATTERED TSRA AND TIMING.
* MEDIUM CONFIDENCE IN LAKE BREEZE DEVELOPING...LOW CONFIDENCE IN
TIMING THROUGH TERMINALS.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...PERIODS OF SHRA/TSRA POSSIBLE.
TUESDAY THROUGH SATURDAY...PERIODIC CHANCES OF SHRA.
KJB
&&
.MARINE...
242 PM...LOW PRESSURE OVER KANSAS WILL MOVE NORTHEAST TO LAKE
SUPERIOR TUESDAY MORNING. AS IT DOES...A WARM FRONT EXTENDING EAST
FROM THE LOW WILL MOVE NORTH ACROSS THE LAKE TONIGHT THROUGH
MONDAY NIGHT...SHIFTING EASTERLY WINDS SOUTHERLY. LOW LEVEL
MOISTURE WILL ALSO BE INCREASING AND AS IT SPREADS ACROSS THE
COOLER LAKE...AREAS OF FOG ARE POSSIBLE AND SOME OF THE FOG MAY
BECOME DENSE. CURRENT WIND SPEEDS ARE FAIRLY LIGHT IN THE 5-15 KT
RANGE AND WILL INCREASE INTO THE 15-25KT RANGE AND REMAIN THERE
UNTIL A COLD FRONT MOVES ACROSS THE LAKE TUESDAY MORNING. THERE IS
A POTENTIAL FOR WINDS TO BE A BIT STRONGER ON MONDAY...ESPECIALLY
WITH THE EASTERLY FLOW NORTH OF THE WARM FRONT ACROSS NORTHERN
LAKE MICHIGAN. THERE REMAINS UNCERTAINTY REGARDING THE POTENTIAL
FOR STRONG NORTHERLY WINDS WEDNESDAY NIGHT INTO THURSDAY AS LOW
PRESSURE DEEPENS MOVING NORTH ACROSS THE GREAT LAKES REGION. THIS
TIME PERIOD WILL NEED TO BE MONITORED FOR HIGHER NORTHERLY WIND
SPEEDS. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1248 PM CDT Sun May 11 2014
.DISCUSSION...
ISSUED 1044 AM CDT Sun May 11 2014
Warm front continues to lift northward through the region this
morning. Boundary is becoming difficult to analyze, as winds have
become southerly across central Illinois, while the tightest dewpoint
gradient remains further south across central Missouri into far
southern Illinois. Cluster of convection is currently ongoing
north of the warm front over southwest Iowa. We will need to keep
a close eye on these storms as they track along the boundary
today. Some models develop this convection eastward into central
Illinois between 1 pm and 4 pm, while the HRRR continues to take
it more northeastward into northern Illinois, generally tracking
along the 850mb warm front. Since convective evolution remains
uncertain, will not be making any changes to the going forecast at
this time. POPs will be highest across the far N/NW KILX CWA in
closer proximity to the upper front and the potential track of the
Iowa convection. Further south into the warm sector, any storms
that fire south of the I-72 corridor will be much more scattered
in nature, so lower POPs are warranted there.
Barnes
&&
.AVIATION...
ISSUED 1248 PM CDT Sun May 11 2014
Thunderstorms currently over south-central Iowa continue to move
E/NE and will enter northwest Illinois after 20z. Current
trajectory should take most of the storms just north of KPIA, so
will only include VCTS between 22z and 02z. Further southeast,
scattered storms are firing in the warm sector across southern
Illinois. HRRR continues to suggest these cells will spread/develop
northward into east-central Illinois this afternoon. Have
therefore included VCTS at the remaining terminals between 21z and
02z, although KSPI may be missed by convection entirely if trends
hold. Gusty S/SE winds will continue through the afternoon and
will remain in the 10 to 15kt range tonight. Meanwhile, a 45kt
925mb jet will develop across the area overnight, warranting a
low-level wind shear mention at the TAF sites. This momentum will
mix to the surface after sunrise, resulting in gusty S/SW winds
Monday morning.
Barnes
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Sun May 11 2014
SHORT TERM...Today through Wednesday night
MCS with showers and scattered thunderstorms from I-72 south to
I-64 early this morning with isolated strong to severe storms
with hail and gusty winds of 40-60 mph moving east at 40 mph
toward the Wabash river. Models show these showers and
thunderstorms diminishing by sunrise as warm front lifts northward
across central and into northern IL during today. Kept a chance of
convection today and tonight though best chances northern areas.
SPC has slight chance of severe storms over most of CWA today and
early evening with moderate risk over central/southern IA into se
NE and north-central KS. SPC has slight risk of severe storms nw of
the IL river late Monday afternoon and Monday evening as cold
front approaches the MS river valley. Warmer highs in the 80s
today and Monday and more humid with dewpoints in the 60s.
Highest chances of convection will be Monday night western areas
and eastern IL Tue with passage of cold front. SPC has 5% risk of
severe storms Tue over far eastern IL with passage of cold front
though better chances further east over IN and lower MI.
Models continue to show surface low pressure ejecting ne from
southern MS river valley into the Ohio river valley Wed and qpf
moving back over central and especially eastern IL and have
increase pops on Wed and Wed evening. Large upper level trof
settles into the Midwest during mid week and have temps cooling
below normal by Wed/Thu with highs in the lower 60s and lows in
the 40s Wed night & Thu night.
LONG TERM...Thursday through Sunday
Extended models have been consistent in showing a large upper
level trof over the Great Lakes region and Midwest during mid/late week
and gradually pulls away from IL by Sunday. Below normal
temperatures expected during mid and late week with temps a good
10 degrees below normal. Instability isolated light showers
possible each day especially during the afternoon and early
evening hours until sunset due to upper level trof and a few
disturbances pivoting through the trof.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1102 AM CDT SUN MAY 11 2014
.DISCUSSION...
1030 AM CDT
THE FORECAST FOR THIS AFTERNOON INTO THE EVENING REMAINS
CHALLENGING...ALTHOUGH OBSERVATIONAL TRENDS ARE STARTING TO SHOW
THEMSELVES SLIGHTLY AND THE EFFECT OF EARLY MORNING UPSTREAM
CONVECTION IS BEGINNING TO BE RESOLVED BETTER BY HIGH RESOLUTION
GUIDANCE.
ONGOING CONVECTION ACROSS WESTERN IA/FAR NORTHERN MO IS SLOWLY
EVOLVING EAST. WATER VAPOR AND VISIBLE SATELLITE ALONG WITH
REGIONAL RADAR MOSAIC INDICATE THE PROBABLE PRESENCE OF AN MCV OR
AT LEAST A LOW AMPLITUDE PERTURBATION IN FAR SOUTHWEST IA. WHILE
THIS FEATURE IS UNLIKELY TO RAPIDLY MOVE EAST DUE TO LARGE SCALE
HEIGHT RISES...INCREASING LOW-LEVEL THETA-E ADVECTION AHEAD OF
THIS ON THE SYNOPTIC AND MESO SCALES IS EVIDENT AND FORECAST TO
INCREASE. WITH DIMINISHING INHIBITION...THERE SHOULD CONTINUE AT
LEAST SOME EASTWARD DEVELOPMENT/EVOLUTION OF SCATTERED MAINLY
SUB-SEVERE CONVECTION INTO NORTHERN MO/EASTERN IA/WEST CENTRAL IL
THROUGH EARLY AFTERNOON.
BECAUSE OF THE OVERNIGHT CONVECTION FAR DOWNSTATE IL...THE
SURFACE WARM FRONT REMAINS SOMEWHAT DIFFUSE IN IL...BUT BASED ON
THE CLEAR PLACEMENT OF THE FRONT IN FAR SOUTHERN IA AND
OBSERVATIONAL TRENDS IN IL...IT IS LIKELY TO BE STRENGTHENING
NEAR THE I-74 CORRIDOR THROUGH LATE THIS MORNING AND EVOLVING
INTO THE SOUTHERN AND WESTERN CWA EARLY THIS AFTERNOON. THIS WILL
BASICALLY INTERSECT THE AFOREMENTIONED SCATTERED/REMNANT
CONVECTION AND INCREASE THE LIKELIHOOD OF STORMS BECOMING LOWER-
ROOTED TO OUR WEST OR POTENTIALLY IN OUR WESTERN/SOUTHERN CWA BY
MID-AFTERNOON. MLCAPE STILL LOOKS TO BE ON THE ORDER OF OVER 2000
J/KG WITH FAVORABLE SHEAR PROFILES FOR WELL-ORGANIZED AND POSSIBLY
DISCRETE SUPERCELL STORMS. SO BASICALLY MORE TOWARD SCENARIO 3 IN
THE AFOREMENTIONED AFD LOOKS TO BE THE MOST PROBABLE...AND THE
TYPES OF SEVERE WEATHER FAVORED MENTIONED BEFORE REMAIN THE SAME.
HOWEVER...THE OVERALL CONFIDENCE ON COVERAGE OF STORMS DURING THE
MID AFTERNOON THROUGH MID-EVE REMAINS LOW.
THE MOST FAVORABLE TIME FOR STORMS IN THE CHICAGOLAND AREA
REMAINS LATER AFTERNOON INTO THE EARLY EVE. IT IS POSSIBLE THE
CONVERGENCE OF THE LAKE BREEZE ACROSS EASTERN COOK AND INTO LAKE
COUNTIES IL TRIGGERS SOME ISOLATED CONVECTION PRIOR TO THIS...AND
A COUPLE CONVECTIVE ALLOWING MODELS INDICATE THAT.
HAVE MADE SOME ADJUSTMENTS TO THE TEMPORAL RESOLUTION OF
THUNDERSTORM CHANCES...BUT OVERALL NO MAJOR FORECAST CHANGES.
WILL CONTINUE TO MONITOR OBSERVATIONAL TRENDS...INCLUDING 17Z RAOB
LAUNCHES...AS IT RELATES TO CONVECTIVE CHANCES AND MAGNITUDES IN
THE FORECAST AREA.
MTF
//PREV DISCUSSION...
330 AM CDT
SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON/EARLY EVENING...HEAT
AND HUMIDITY MAKE AN APPEARANCE...THEN TRANSITION TO COLDER
UNSETTLED WEATHER LATER THIS WEEK.
VERY TRICKY FORECAST FOR TODAY...PARTICULARLY IN LIGHT OF MUCH OF
THE SHORT RANGE MODEL GUIDANCE STRUGGLING TO GET A GOOD HANDLE ON
ONGOING CONVECTION. WARM FRONT CURRENTLY LOCATED NEAR THE I-70
CORRIDOR IS BEING CONVECTIVELY ENHANCED BY MCS THAT IS TRACKING
ACROSS DOWNSTATE ILLINOIS...SOMETHING A LOT OF GUIDANCE HAS MISSED
ALTOGETHER. RISING HEIGHTS AND DEVELOPING SURFACE CYCLONE OVER THE
PLAINS SHOULD ALLOW THE WARM FRONT TO MIX NORTH FAIRLY QUICKLY TODAY
AND LIKELY MOVING INTO NORTHERN ILLINOIS THIS AFTERNOON. WARM FRONT
IS EXPECTED TO BECOME BETTER DEFINED THIS AFTERNOON AS CYCLONE OVER
THE PLAINS ORGANIZES WITH INCREASINGLY STRONG PRESSURE FALLS OVER
IOWA LIKELY TO RESULT IN A BACKING OF THE LOW LEVEL WINDS THIS
AFTERNOON...ESPECIALLY NORTH OF THE FRONT AT THE SURFACE.
TO ME THERE LOOKS TO BE 3 MOST PROBABLE POSSIBLE SCENARIOS
CONVECTIVELY TODAY. FIRST...THE LEAST LIKELY SEEMS TO BE THE CAP
HOLDING STRONG AND NO OR ONLY VERY ISOLATED THUNDERSTORMS FORMING. A
SECOND POSSIBLE SCENARIO THAT SEVERAL OF THE CONVECTIVE ALLOWING
MODELS (CAMS) SUGGEST WOULD BE AN MCS ORGANIZING OVER IOWA TOWARD
SUNRISE...THEN MOVING EAST INTO NORTHERN ILLINOIS THIS AFTERNOON.
CONVECTIVE TRENDS CURRENT DON`T SEEM TO FAVOR THIS SCENARIO WITH
STORMS OVER THE EASTERN PLAINS EAST INTO MISSOURI WEAKENING WITH
RENEWED DEVELOPMENT FARTHER WEST OVER NEBRASKA AND KANSAS PRETTY
UNLIKELY TO REACH OUR AREA THIS AFTERNOON. THE FINAL POSSIBLE
SCENARIO...AND THE ONE THAT SEEMS MOST PLAUSIBLE...WOULD BE
SCATTERED THUNDERSTORMS DEVELOPING NEAR THE SHARPENING WARM FRONT
THIS AFTERNOON AS STRONG HEATING ERODES CONVECTIVE INHIBITION.
SEVERE THREAT THIS AFTERNOON/EARLY THIS EVENING WILL OBVIOUSLY BE
DEPENDENT ON HOW CONVECTION EVOLVES. FOR INSTANCE...SCENARIO 2 WITH
THE REMNANT MCS WOULD TEND TO FAVOR A MULTICELL WIND/HAIL THREAT.
SCENARIO 3 IS SOMEWHAT MORE CONCERNING...GIVEN THE SOMEWHAT NEBULOUS
FORCING WOULD EXPECT CONVECTION TO DEVELOP TO BE MORE SCATTERED AND
CELLULAR IN NATURE. THERE ARE CERTAINLY SOME NOTABLE DIFFERENCES IN
THE MODELS WITH RESPECT TO SHEAR PROFILES THIS AFTERNOON...BUT ALL
GUIDANCE SUGGESTS AND VEERING AND SLOWLY INCREASING MID LEVEL
FLOW...WITH BACKING LOW LEVEL AND SURFACE FLOW INCREASING HODOGRAPH
SIZES LATE THIS AFTERNOON. MANY OF THE MODELS ACTUALLY SHOW A VERY
NICE VEERING/INCREASING WIND PROFILE FROM THE SFC-6KM QUITE
FAVORABLE FOR SUPERCELLS. ALSO OF CONCERN IS WIND PROFILES WOULD
FAVOR RIGHT MOVING SUPERCELLS WITH AN EASTERLY MOTION ROUGHLY
PARALLEL TO THE WARM FRONT. FAR MORE UNCERTAINTY EXISTS IN OUR AREA
COMPARED TO POINTS WEST IN THE MODERATE RISK OVER IOWA AND
NEBRASKA...BUT IF CONVECTION OCCURS AND MODE IS FAVORABLE THEN THERE
MAY WELL BE A SEVERAL HOUR LONG WINDOW FAVORABLE CONDITIONS FOR
SUPERCELL(S) WITH A LARGE HAIL AND TORNADO POTENTIAL LOCALLY LATE
THIS AFTERNOON AND EVERY EARLY THIS EVENING.
OTHER FORECAST CONCERNS TODAY INCLUDE CLOUD COVER AND TEMPS. A LOT
OF CLEAR SKIES HERE WEST INTO IOWA REALLY RAISE DOUBTS ABOUT HOW
CLOUDY MUCH OF THE GUIDANCE HAS THINGS TODAY. CONVECTIVE DEBRIS FROM
ACTIVITY OVER MISSOURI COULD LEAD TO SOME CLOUDINESS THIS
MORNING...BUT QUICKLY WARMING CLOUD TOPS ALREADY SUGGEST THAT THIS
MAY NOT BE MUCH OF A FACTOR. ASSUMING WE GET A FAIR AMOUNT OF
SUNSHINE...WHICH SEEMS PRETTY LIKELY...THEN TEMPERATURES COULD
EASILY GET OUT OF HAND. HAVE RAISED HIGHS SEVERAL DEGREES...BUT
WOULD NOT BE SURPRISING TO SEE TEMPS WELL INTO 80S THIS AFTERNOON.
AS CYCLONE DEEPENS AND PRESSURE FALLS INCREASE TO OUR WEST THE
SYNOPTIC GRADIENT IS LIKELY TO BACK MORE SOUTHEASTERLY WHICH SHOULD
ALLOW A LAKE BREEZE TO COME CHARGING WEST INTO NE IL SENDING TEMPS
DROPPING. HIGHER DEWPOINTS WILL PROBABLY STILL BE SOUTH OF THIS AREA
SO MOST LIKELY JUST A RESPECTABLE TEMP DROP AND NOT A LAKE SHORE FOG
PROBLEMS.
WARM FRONT LIKELY TO BLAST NORTH INTO WISCONSIN TONIGHT SENDING
TEMPS SOARING IN THE LAKE COOLED AREAS OF NE IL THIS EVENING AND
ALLOWING TEMPS TO REMAIN UNSEASONABLY WARM ELSEWHERE. FOCUS FOR
CONVECTION TONIGHT SHOULD SHIFT INTO WISCONSIN WITH MAJORITY OF OUR
AREA REMAINING DRY...THOUGH AM RELUCTANT TO REMOVE POPS ALTOGETHER
GIVEN THE INHERENT UNCERTAINTIES DEALING WITH CONVECTIVE EVOLUTION.
MONDAY LOOKS POISED TO BE BREEZY AND UNSEASONABLY WARM AND RATHER
HUMID AS WE RESIDE FIRMLY IN THE WARM SECTOR OF THE CYCLONE. QUICKLY
WARMING TEMPS ALOFT WITH CONTINUED HEIGHT RISES SUGGEST THAT ANY
LEFT OVER CONVECTION SHOULD FADE BEFORE MAKING IT INTO OR VERY FAR
EAST ACROSS OUR CWA MONDAY MORNING. HAVE BUMPED UP TEMPS INTO THE
MID TO UPPER 80S...THOUGH WITH ENOUGH SUNSHINE SOME AREAS COULD
EASILY REACH 90 DEGREES AGAIN GIVEN 850/925MB TEMPS PROGGED TO BE
PRETTY SIMILAR TO WHAT WE SAW THURSDAY. BY AFTERNOON RAIN CHANCES
LOOK SLIM WITH BETTER FORCING WELL WEST OF THE CWA ACROSS IOWA WHERE
STRONG TO SEVERE THUNDERSTORMS ARE LIKELY TO DEVELOP LATE MONDAY
AFTERNOON.
THE LEFT OVERS OF THESE STORMS ARE LIKELY TO MOVE SLOWLY EASTWARD
TOWARD OUR CWA...BUT SHOULDNT ARRIVE UNTIL AFTER DARK AND PROBABLY
WELL AFTER DARK. STABILIZING BOUNDARY LAYER/INCREASING
CINH...MARGINAL SHEAR PROFILES...AND BETTER UPPER FORCING LAGGING TO
THE WEST SUGGEST THAT THE STORMS SHOULD BE IN A WEAKENING PHASE AS
THEY MOVE IN AND THAT LEAVES ME FAR FROM TINGLY ABOUT ANY MEANINGFUL
SEVERE THREAT MONDAY NIGHT.
STILL LOOKS TO BE A MUCH...MUCH COLDER PATTERN SETTING UP FOR THE
MIDDLE AND END OF THE WEEK WITH AN ANOMALOUSLY STRONG UPPER TROUGH
BECOMING ESTABLISHED OVER THE REGION. MEDIUM RANGE MODELS CONTINUE
TO DIFFER SUBSTANTIALLY IN THEIR HANDLING OF THE SMALLER SCALE WAVES
AND SUBSEQUENT BETTER SHOWER CHANCES...SO LEFT WITH LITTLE CHOICE
THAN PERIOD AFTER PERIOD OF SHOWER CHANCES WEDNESDAY ONWARD.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SOUTH WINDS TODAY...SHIFTING EAST-SOUTHEASTERLY AFTER 23 UTC
THIS AFTERNOON.
* CHANCES AND TIMING OF SCT TSRA THIS AFTERNOON/EVENING...BEST
CHANCES BETWEEN 23 AND 03 UTC.
* LLWS POTENTIAL LATE SUNDAY EVENING WITH 1500-2000 FT WIND SSW
40-50 KT.
KJB/BMD
//DISCUSSION...UPDATED 12Z...
THE MAIN FORECAST CONCERNS TODAY WILL CONTINUE TO FOCUS ON THE
CHANCES AND TIMING FOR CONVECTION IN AND NEAR THE TERMINALS THIS
AFTERNOON/EVENING...AND ALSO WIND DIRECTIONS...ESPECIALLY LATER THIS
AFTERNOON AND EVENING TO THE NORTH OF AN APPROACHING WARM FRONTAL
ZONE.
AN INCREASINGLY UNSETTLED WEATHER PATTERN WILL BE SETTING UP
ACROSS THE REGION THROUGH THE DAY AS A BROAD AREA OF LOW PRESSURE
ACROSS THE PLAINS BEGINS TO CONSOLIDATE AND MOVE TOWARDS THE MID
MISSOURI VALLEY LATER TODAY AND TONIGHT. AS THIS OCCURS...AN
ASSOCIATED WARM FRONTAL ZONE WILL BEGIN TO LIFT NORTHWARD ACROSS
CENTRAL ILLINOIS TODAY...THEN SURGE NORTHWARD ACROSS THE REGION
LATER THIS EVENING. AN INCREASINGLY WARM...MOIST AND UNSTABLE
ATMOSPHERE WILL LIKELY ACCOMPANY THIS WARM FRONT...SETTING UP THE
STAGE FOR A POSSIBLE PERIOD OF SOME SCATTERED CONVECTIVE ACTIVITY
LATER THIS AFTERNOON AND EVENING. THE BEST THREAT FOR CONVECTIVE
ACTIVITY OVER OR NEAR THE TERMINALS APPEARS TO FROM AROUND 22 UTC
THROUGH 02 UTC THIS EVENING. ALTHOUGH THE ACTUAL CHANCES OF
CONVECTIVE ACTIVITY HAVE NOT REALLY CHANGED...I HAVE REPLACED THE
PROB 30 GROUP WITH A VCTS AND TEMPO GROUP FOR THUNDERSTORMS. THE
MAIN REASON FOR DOING THIS IS THAT I AM NOT COMFORTABLE NOT HAVING
A MENTION OF THUNDER IN THE TAFS...AND RULES PROHIBIT THE USE OF A
PROB 30 GROUP WITHIN THE FIRST 9 HOURS OF THE TAF.
THE CONVECTIVE THREAT LOOKS TO SHIFT NORTHWARD ACROSS SOUTHERN
WISCONSIN LATER THIS EVENING AND OVERNIGHT AS THE WARM FRONT
SURGES NORTHWARD...SO IT APPEARS NO ADDITIONAL MENTIONS OF
CONVECTION ARE NEEDED IN THE TAF TONIGHT.
THE OTHER CONCERN LATER TODAY WILL BE THE WINDS. FORECAST GUIDANCE
INDICATES THAT A SOUTH-SOUTHWESTERLY WIND COMPONENT EARLY IN THE
DAY WILL BACK MORE EAST-SOUTHEASTERLY LATER IN THE AFTERNOON AND
EVENING ACROSS NORTHERN ILLINOIS IN RESPONSE TO PRESSURE FALLS
ACROSS IOWA AND NORTHWESTERN ILLINOIS. THIS MAY PROMOTE A LAKE
BREEZE TO DEVELOP AND MOVE INLAND...POSSIBLY CAUSING THE WINDS TO
BECOME DUE EASTERLY AT THE EASTERN TAF SITES FOR A PERIOD EARLY
EVENING. THE WINDS WILL EVENTUALLY SHIFT BACK OUT OF THE SOUTH
AGAIN TONIGHT AFTER THE WARM FRONT SURGES NORTH OF THE TERMINALS.
SOME LOW LEVEL WIND SHEAR COULD ALSO SET UP FOR A PERIOD LATE
TONIGHT AS A SOUTH-SOUTHWESTERLY 45+ KT LOW LEVEL SETS UP OVER THE
REGION.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* LOW WITH OCCURRENCE/TIMING OF EAST-SOUTHEASTERLY WIND SHIFT THIS
AFTERNOON/EVENING.
* MEDIUM-LOW CONFIDENCE IN TSRA TIMING/COVERAGE THIS
AFTERNOON/EVE.
* MEDIUM CONFIDENCE IN LLWS TONIGHT.
KJB/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...PERIODS OF SHRA/TSRA POSSIBLE.
TUESDAY THROUGH SATURDAY...PERIODIC CHANCES OF SHRA.
KJB
&&
.MARINE...
232 AM CDT
AN ACTIVE WEATHER PATTERN IS LIKELY ACROSS THE LAKE OVER THE NEXT
COUPLE OF DAYS AS AN AREA OF LOW PRESSURE TRACKS FROM THE PLAINS
NORTHEASTWARD TOWARDS LAKE SUPERIOR BY MONDAY NIGHT. ULTIMATELY THIS
WILL RESULT IN A WARM FRONTAL BOUNDARY LIFTING NORTHWARD UP THE LAKE
TONIGHT THROUGH EARLY TUESDAY...FOLLOWED BY A COOL FRONTAL PASSAGE
ON TUESDAY. WINDS SOUTH OF THIS WARM FRONT WILL BECOME SOUTHERLY UP
AROUND 25 KT...WHILE NORTH OF THE WARM FRONT...SOME STOUT EASTERLY
WINDS WILL BE LIKELY. DUE TO THE PRESENCE OF HIGHER DEW POINT AIR
LIFTING OVER THE RELATIVELY COOLER WATER...AREAS OF FOG ARE ALSO
EXPECTED...ESPECIALLY IN THE VICINITY OF THE WARM FRONT. SOME PERIODS
OF DENSE FOG CANNOT BE RULED OUT TONIGHT INTO MONDAY. IN ADDITION TO
ALL THIS...THERE WILL ALSO BE A COUPLE PERIODS OF THUNDERSTORMS...LATER
TODAY THROUGH MONDAY. SOME OF THESE COULD PRODUCE STRONG WINDS AND
HAIL. ONCE THE COOL FRONT PASSES ON TUESDAY...CONDITIONS SHOULD
QUIET DOWN FOR A PERIOD.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1044 AM CDT Sun May 11 2014
.DISCUSSION...
ISSUED 1044 AM CDT Sun May 11 2014
Warm front continues to lift northward through the region this
morning. Boundary is becoming difficult to analyze, as winds have
become southerly across central Illinois, while the tightest dewpoint
gradient remains further south across central Missouri into far
southern Illinois. Cluster of convection is currently ongoing
north of the warm front over southwest Iowa. We will need to keep
a close eye on these storms as they track along the boundary
today. Some models develop this convection eastward into central
Illinois between 1 pm and 4 pm, while the HRRR continues to take
it more northeastward into northern Illinois, generally tracking
along the 850mb warm front. Since convective evolution remains
uncertain, will not be making any changes to the going forecast at
this time. POPs will be highest across the far N/NW KILX CWA in
closer proximity to the upper front and the potential track of the
Iowa convection. Further south into the warm sector, any storms
that fire south of the I-72 corridor will be much more scattered
in nature, so lower POPs are warranted there.
Barnes
&&
.AVIATION...
ISSUED 700 AM CDT Sun May 11 2014
A warm front lifting north across the area will stall out from
Galesburg to Champaign. Strong to severe storms will be possible
as early as 18-19z, but higher potential will occur as the
afternoon progresses. Timing of storms at each terminal site is
still uncertain, so VCTS was still left in this set of TAFs for
the afternoon into early evening. NCEP 4km WRF output has
scattered storms developing periodically across the area, so
multiple episodes of stormy weather could occur at any site. Any
periods of MVFR will be mainly during any thunderstorms and
primarily associated with visibility dropping during heavy rain.
Forecast soundings indicate cloud levels should remain VFR, even
during thunderstorms. However, brief MVFR conditions from cloud
levels will also be possible during any storms.
Winds will increase from the south by afternoon, with 15G28KT
possible in most areas. The northern terminals of PIA, BMI and CMI
will be closer to the front, so wind direction may be slightly
east of south and a little less gusty, but will still be breezy.
LLWS conditions are expected later tonight as an elevate low level
jet intensifies from SW to NE across the area. Wind direction
looks to be SW with wind speeds of 45kt in the 1200-1500 foot
level.
Shimon
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT Sun May 11 2014
SHORT TERM...Today through Wednesday night
MCS with showers and scattered thunderstorms from I-72 south to
I-64 early this morning with isolated strong to severe storms
with hail and gusty winds of 40-60 mph moving east at 40 mph
toward the Wabash river. Models show these showers and
thunderstorms diminishing by sunrise as warm front lifts northward
across central and into northern IL during today. Kept a chance of
convection today and tonight though best chances northern areas.
SPC has slight chance of severe storms over most of CWA today and
early evening with moderate risk over central/southern IA into se
NE and north-central KS. SPC has slight risk of severe storms nw of
the IL river late Monday afternoon and Monday evening as cold
front approaches the MS river valley. Warmer highs in the 80s
today and Monday and more humid with dewpoints in the 60s.
Highest chances of convection will be Monday night western areas
and eastern IL Tue with passage of cold front. SPC has 5% risk of
severe storms Tue over far eastern IL with passage of cold front
though better chances further east over IN and lower MI.
Models continue to show surface low pressure ejecting ne from
southern MS river valley into the Ohio river valley Wed and qpf
moving back over central and especially eastern IL and have
increase pops on Wed and Wed evening. Large upper level trof
settles into the Midwest during mid week and have temps cooling
below normal by Wed/Thu with highs in the lower 60s and lows in
the 40s Wed night & Thu night.
LONG TERM...Thursday through Sunday
Extended models have been consistent in showing a large upper
level trof over the Great Lakes region and Midwest during mid/late week
and gradually pulls away from IL by Sunday. Below normal
temperatures expected during mid and late week with temps a good
10 degrees below normal. Instability isolated light showers
possible each day especially during the afternoon and early
evening hours until sunset due to upper level trof and a few
disturbances pivoting through the trof.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
917 PM EDT MON MAY 12 2014
.SYNOPSIS...
ISSUED AT 635 PM EDT MON MAY 12 2014
LOW PRESSURE WILL TRACK NORTHEAST INTO WESTERN LAKE SUPERIOR
TOWARDS TUESDAY MORNING. A COLD FRONT...EXTENDING SOUTH FROM THE
LOW...WILL SWEEP ACROSS ILLINOIS TONIGHT INTO EARLY TUESDAY AND
THEN ACROSS THE REMAINDER OF THE REGION TUESDAY. SCATTERED SHOWERS
AND THUNDERSTORMS CAN BE EXPECTED ALONG THE FRONT.
LOWS TONIGHT WILL BE IN THE 60S WITH HIGHS TUESDAY IN THE UPPER
60S NEAR LAKE MICHIGAN TO MIDDLE 80S OVER CENTRAL OHIO.
&&
.UPDATE...
ISSUED AT 908 PM EDT MON MAY 12 2014
HAVE LOWERED POPS NEXT COUPLE OF HOURS...ESPECIALLY S AREAS WHERE
NO CONVECTION HAS MANAGED TO FIRE THUS FAR THIS EVENING. FURTHER
NORTH WIDELY SCT SHOWERS AND A FEW STORMS HAVE CONTINUED TO
DEVELOP WITH MOST ACTIVITY STILL CONFINED ACROSS NW OHIO. WITH
LOSS OF HEATING...CONVECTION HAS BEEN RAPIDLY DIMINISHING.
FOCUS WILL SHIFT TO 2 AREAS FOR THE OVERNIGHT HOURS INTO TUESDAY
MORNING. THE FIRST MORE OBVIOUS TARGET IS STG-SVR LINE OF STORMS
EXTENDING FROM SW WISCONSIN INTO WESTERN ILLINOIS. THESE HAVE HAD
A HISTORY OF DAMAGING WINDS AND HAIL...BUT MAY BEGIN TO WEAKEN
WITH EASTWARD PROGRESS. AREA 2 IS REMNANTS OF CONVECTION ACROSS
SOUTHERN ILLINOIS. HRRR AND RUC13 BRING WHAT`S LEFT OF THIS
AREA...ASSOCIATED WITH A SUBTLE WAVE WHICH IS NOTED ON WATER
VAPOR...AND MOVES IT NE TOWARDS THE WESTERN PARTS OF THE CWA AS
LLJ RAMPS UP ACROSS ILLINOIS INTO WESTERN INDIANA LATER TONIGHT.
SOME HGT FALLS WILL BE UNDERWAY ALOFT IN RESPONSE TO THE
APPROACHING COLD FRONT FROM THE WEST AS WELL. THIS MAY ALL ALLOW
FOR RENEWED/CONTINUED DEVELOPMENT W AND S OF THE AREA THAT COULD
MOVE IN LATER TONIGHT. NOT ENOUGH CONFIDENCE OVERNIGHT TO RAISE TO
LIKELY AT THIS STAGE. HOWEVER...TRENDS WILL BE CLOSELY MONITORED
NEXT COUPLE OF HOURS. SVR RISK QUITE MINIMAL WITH GREATER THREAT
OF HEAVY RAINFALL AND TRAINING OF CELLS GIVEN EXPECTED SLOW
MOVEMENT OF STORMS...AS HAS BEEN OBSERVED WITH CONVECTION ACROSS N
ILLINOIS INTO LWR MI.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 331 PM EDT MON MAY 12 2014
WELL DEVELOPED MCS AND ASSOCIATED SURFACE LOW OVER IA/WI/MN MOVING
QUICKLY NORTH AND EAST. DEEP CONVECTION OVER WISCONSIN WILL PUSH
ACROSS LAKE MICHIGAN DURING THE EARLY EVENING AND CONVECTION NOW
MOVING ACROSS CENTRAL IOWA WILL SET THE STAGE FOR CONVECTION IN OUR
AREA LATE TONIGHT...EARLY TUESDAY MORNING.
SHORTWAVE TROF NOW MOVING THROUGH NORTHERN INDIANA AND SOUTHERN
LOWER MICHIGAN HAS TRIGGERED ISOLATED THUNDERSTORMS. THIS MARKS THE
LEADING EDGE OF PRONOUNCED SUBSIDENCE REGION EXTENDING FROM CENTRAL
ILLINOIS AND WESTERN INDIANA. EVEN WITH LARGE MU/MLCAPE
VALUES...CONVECTION IS LACKING ANY SUPPORT FOR ORGANIZED DEEP
CONVECTION OVER THE FORECAST AREA...MOST FAVORED REGION STILL
APPEARS TO BE ASSOCIATED WITH THE WARM FRONT OVER CENTRAL/NRN MI
ACROSS LAKE MICHIGAN TO THE MCC OVER WISCONSIN.
OUTFLOW FROM THE SYSTEM IN WISCONSIN WILL PUSH INTO THE FORECAST
AREA BY TUESDAY MORNING AND WOULD EXPECT TO SEE CONVECTION BECOME
MORE ORGANIZED AND WIDESPREAD DURING THE EARLY MORNING
TUESDAY...THEN AS THE TROF AXIS AND COLD FRONT PROGRESS
THROUGH...BECOME MORE SYNOPTICALLY DRIVEN RAINFALL EVENT WITH
EMBEDDED THUNDERSTORMS. DEEP BOUNDARY LAYER MOISTURE WILL LEAD TO
POTENTIALLY HEAVY RAINFALL OVER THE FORECAST AREA UNTIL EARLY
EVENING TUESDAY.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 331 PM EDT MON MAY 12 2014
POTENT SW DISTURBANCE ACRS THE FOUR CORNERS WILL LIFT OUT THROUGH
THE SRN PLAINS TONIGHT AND THEN PHASE NEWD W/NRN STREAM SW
DISTURBANCE AMPLIFYING THROUGH THE NRN LAKES. RESULTING ANOMALOUSLY
DEEP COLD CORE CLOSED LOW XPCD TO THEN LINGER THROUGH THE WEEKEND
ACRS NEW ENGLAND.
THUS PRIMARY FTR OF NOTE THIS PD IS W/ASSOCD SECONDARY FNTL WAVE
DVLPMNT THAT TAKES PLACE LT WED ACRS THE SRN MS VALLEY AND WHICH
LIFTS NEWD THROUGH ERN OH LT THU. XPC A FAIRLY ROBUST MID LVL FGEN
PRECIP SHIELD WILL DVLP POST FNTL WED AFTN FOLLOWED BY A MATURING
DEFORMATION BAND OF PRECIP WED NIGHT/THU AM AS DENOTED IN WELL
ALIGNED MODEL CONSENSUS. WILL CONT PRIOR TRENDS IN BUMPING POPS
SUCCESSIVELY HIGHER.
OTRWS SYS SLOWLY PULLS OFF NEWD THROUGH SAT W/POTENTIAL DIURNALLY
DRIVEN SHRA UNDERNEATH IMPRESSIVE COLD POOL ALOFT BOTH FRI AND SAT
AFTN. HWVR ROBUST DRY ADVTN AUGMENTED THROUGH SIG LK MI LAKE SHADOW
WILL LIKELY KEEP NW CWA DRY THROUGHOUT AND WILL SHUFFLE POPS AROUND
A BIT TO REFLECT MODEL BLEND. TEMPS WELL BLO NORMAL THROUGH THE PD
ALTHOUGH MOIST CYCLONIC FLW AND NON-ZERO GRADIENT FLW SHLD STAVE OFF
ANY FROST CONCERNS THU/FRI NIGHT. EXCEPTION MAY PRESENT ITSELF LT
SAT NIGHT INVOF SFC RIDGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 625 PM EDT MON MAY 12 2014
WILL CONTINUE TO MONITOR CONVECTIVE TRENDS OVER THE NEXT COUPLE OF
HOURS WITH ISOLATED SHOWERS (POSSIBLE RUMBLE OF THUNDER) POSSIBLY
IMPACTING BOTH TAF SITES THIS EVENING. COVERAGE/CONFIDENCE LOW
ENOUGH TO KEEP OUT OF TAFS. LLWS MAY STILL POSE AN ISSUE LATER
TONIGHT BUT WILL HOLD OFF ON ADDING WITH BORDERLINE SETUP.
CHANCES FOR SHOWERS AND STORMS MAY INCREASE LATER TONIGHT...WITH
BEST CHANCE AFTER 12Z AS COLD FRONT DRAWS CLOSER. MAY NEED TO ADD
MENTION OF THUNDER AT KFWA GIVEN BETTER POSITIONING WITH REGARDS
TO FRONT AND TIME OF DAY...BUT WILL HOLD OFF FOR NOW WITH
OVERNIGHT CONVECTIVE EVOLUTION LIKELY TO BE KEY IN CHANCES ON
TUESDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LMZ043-046.
&&
$$
UPDATE...FISHER
SYNOPSIS...LEWIS
SHORT TERM...LEWIS
LONG TERM...T
AVIATION...FISHER
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
230 AM EDT SUN MAY 11 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 245 PM EDT SAT MAY 10 2014
A FRONT WILL MEANDER ACROSS THE AREA THIS WEEKEND KEEPING CHANCES
FOR RAIN IN THE FORECAST. ANOTHER FRONT WILL BRING MORE RAIN CHANCES
NEXT WEEK. TEMPERATURES WILL WARM TO ABOVE AVERAGE BY EARLY NEXT
WEEK...THEN FALL TO BELOW AVERAGE FROM MID WEEK ON BEHIND THE COLD
FRONT.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 1004 PM EDT SAT MAY 10 2014
CLOUD DEBRIS FROM WARM FRONTAL CONVECTION ACROSS MISSOURI ALREADY
RETURNING INTO THE HOOSIER STATE AS OF 0130Z. TEMPS WERE PRIMARILY
IN THE 60S AT THE MID EVENING POINT.
FRONTAL BOUNDARY AT 0130Z EXTENDING ACROSS FAR SOUTHERN INDIANA
BACK TO NEAR KSTL THEN CONTINUING WEST INTO NORTH CENTRAL
MISSOURI. BOUNDARY ALREADY SHOWING SIGNS OF LIFTING BACK NORTH
OVER THE LAST FEW HOURS...AND WILL CONTINUE TO DO SO OVERNIGHT.
IMPRESSIVE POCKET OF DRY AIR HAS SLIPPED SOUTH INTO NORTHERN PORTIONS
OF THE FORECAST AREA...WITH DEWPOINTS INTO THE MIDDLE/UPPER 30S
FROM INDY NORTHEAST. THESE LOWER DEWPOINTS WILL QUICKLY RECOVER AS
THE BOUNDARY RETURNS INTO THE FORECAST AREA OVER THE NEXT SEVERAL
HOURS.
THE MAIN ISSUE FOR THE UPDATE IS THE EXPECTED TRACK OF THE
CONVECTION ACROSS THE MID MISSISSIPPI VALLEY AND THE STATE OF
INTENSITY ITS LIKELY TO BE IN WHEN IT ARRIVES IN THE REGION. BOTH
THE RAP AND HRRR MOVE CONVECTION ALONG THE WARM FRONT OVER THE
NEXT FEW HOURS...LIKELY REACHING THE WABASH RIVER BETWEEN KHUF AND
KLWV BY AROUND 07Z. EXPECT SHOWERS AND EMBEDDED STORMS TO
OVERSPREAD PRIMARILY THE SOUTHERN HALF OF THE FORECAST AREA IN A
WEAKENED CONDITION THEREAFTER AS THE WARM FRONT LIFTS NORTH. WILL
CARRY LOWER POPS FURTHER NORTH.
OVERNIGHT LOWS RANGING FROM THE MID 50S OVER NORTHEAST COUNTIES TO
THE MID 60S IN THE LOWER WABASH VALLEY LOOK REASONABLE AND LITTLE
CHANGE WAS MADE. ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ISSUED AT 245 PM EDT SAT MAY 10 2014
FOCUS WILL CONTINUE TO BE ON THUNDERSTORM CHANCES THROUGH THE ENTIRE
SHORT TERM AS LOW PRESSURE SYSTEM GRADUALLY MIGRATES EAST FROM THE
PLAINS.
ECMWF CONTINUES TO BE THE MOST CONSISTENT OF THE MODELS REGARD
SLOWLY MOVING FRONTAL SYSTEM. ASSOCIATED COLD FRONT LOOKS LIKE IT
WILL NOT MOVE ACROSS CENTRAL INDIANA UNTIL TUESDAY AFTERNOON AND
NIGHT.
ON SUNDAY...WARM FRONT SHOULD LIFT NORTHEAST ACROSS CENTRAL INDIANA
WHICH SHOULD TRIGGER SCATTERED THUNDERSTORMS WITH MODELS ALL SHOWING
MIXED LAYER CAPES FROM 1000-2000 J/KG...INCREASED LOW LEVEL MOISTURE
AND SOME RESULTING QPF. THEN...WITH THE AREA IN THE WARM SECTOR FROM
SUNDAY NIGHT THROUGH MONDAY NIGHT...SHOULD SEE WARMER TEMPERATURES
IN THE 80S ON MONDAY PER 12Z MOS BLEND AND CONSALL. WILL STICK WITH
LOW POPS SUNDAY NIGHT THROUGH MONDAY NIGHT WITH AMPLE INSTABILITY
AND POSSIBLY LEFTOVER OUTFLOW BOUNDARIES BUT ONLY WEAK SYNOPTIC
FORCING WITH UPPER WAVES IN SOUTHWEST FLOW.
BEST CHANCE OF THUNDERSTORMS WILL BE ON TUESDAY AS THE FRONT
APPROACHES AND MOVES AT LEAST PART OF THE WAY ACROSS THE FORECAST
AREA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 230 AM EDT SUN MAY 11 2014
CONFIDENCE IS BUILDING FOR PRECIP EVENT ON WEDNESDAY AS THE GFS
AND ECMWF CONTINUE TO SUGGEST THE LAST OF THE DYNAMICS ASSOCIATED
WITH AN APPROACHING TROUGH WILL PASS INTO INDIANA. HAVE RAISED
POPS HERE.
CONFIDENCE WANES LATER IN THE FORECAST PERIOD. GFS AND ECMWF
CONTINUE TO SUGGEST THAT BROAD CYCLONIC FLOW WILL REMAIN IN PLACE
ACROSS THE REGION...HOWEVER COOL AND DRY NORTHWEST LOWER LEVEL
FLOW IS EXPECTED TO PERSIST...LIMITING MOISTURE. THUS HAVE TRENDED
DRIER AND COOLER DURING THIS PERIOD.
&&
.AVIATION /DISCUSSION FOR 110600Z TAF ISSUANCE/...
ISSUED AT 1259 AM EDT SUN MAY 11 2014
SITES WILL START OUT VFR AND DRY WITH A FRONT ACROSS SOUTHERN
INDIANA. THIS WILL SLOWLY LIFT NORTH AS A WARM FRONT. SHOWERS AND
THUNDERSTORMS OVER CENTRAL ILLINOIS WILL MOVE IN TO THE SITES
STARTING AFTER ABOUT 8Z. UNCERTAIN HOW MUCH THUNDER WILL BE LEFT AT
THAT POINT...SO WILL INCLUDE A VCTS WITH SHOWERS. EXPECT WINDS TO BE
LIGHT AND VARIABLE FOR A FEW HOURS BUT PICK UP AGAIN SUNDAY MORNING
OUT OF THE SOUTHEAST AND THEN SOUTH BY SUNDAY AFTERNOON...AROUND 5-8
KTS IN THE MORNING THEN 10-15 KTS IN THE AFTERNOON.
MORE CHANCES FOR RAIN AND THUNDER ARE IN THE FORECAST FOR SUNDAY
AFTERNOON...BUT UNCERTAINTY IS HIGH ENOUGH TO LEAVE OUT FOR NOW AND
JUST INCLUDE A BROKEN DECK.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....PUMA
AVIATION...CP
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1259 AM EDT SUN MAY 11 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 245 PM EDT SAT MAY 10 2014
A FRONT WILL MEANDER ACROSS THE AREA THIS WEEKEND KEEPING CHANCES
FOR RAIN IN THE FORECAST. ANOTHER FRONT WILL BRING MORE RAIN CHANCES
NEXT WEEK. TEMPERATURES WILL WARM TO ABOVE AVERAGE BY EARLY NEXT
WEEK...THEN FALL TO BELOW AVERAGE FROM MID WEEK ON BEHIND THE COLD
FRONT.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 1004 PM EDT SAT MAY 10 2014
CLOUD DEBRIS FROM WARM FRONTAL CONVECTION ACROSS MISSOURI ALREADY
RETURNING INTO THE HOOSIER STATE AS OF 0130Z. TEMPS WERE PRIMARILY
IN THE 60S AT THE MID EVENING POINT.
FRONTAL BOUNDARY AT 0130Z EXTENDING ACROSS FAR SOUTHERN INDIANA
BACK TO NEAR KSTL THEN CONTINUING WEST INTO NORTH CENTRAL
MISSOURI. BOUNDARY ALREADY SHOWING SIGNS OF LIFTING BACK NORTH
OVER THE LAST FEW HOURS...AND WILL CONTINUE TO DO SO OVERNIGHT.
IMPRESSIVE POCKET OF DRY AIR HAS SLIPPED SOUTH INTO NORTHERN PORTIONS
OF THE FORECAST AREA...WITH DEWPOINTS INTO THE MIDDLE/UPPER 30S
FROM INDY NORTHEAST. THESE LOWER DEWPOINTS WILL QUICKLY RECOVER AS
THE BOUNDARY RETURNS INTO THE FORECAST AREA OVER THE NEXT SEVERAL
HOURS.
THE MAIN ISSUE FOR THE UPDATE IS THE EXPECTED TRACK OF THE
CONVECTION ACROSS THE MID MISSISSIPPI VALLEY AND THE STATE OF
INTENSITY ITS LIKELY TO BE IN WHEN IT ARRIVES IN THE REGION. BOTH
THE RAP AND HRRR MOVE CONVECTION ALONG THE WARM FRONT OVER THE
NEXT FEW HOURS...LIKELY REACHING THE WABASH RIVER BETWEEN KHUF AND
KLWV BY AROUND 07Z. EXPECT SHOWERS AND EMBEDDED STORMS TO
OVERSPREAD PRIMARILY THE SOUTHERN HALF OF THE FORECAST AREA IN A
WEAKENED CONDITION THEREAFTER AS THE WARM FRONT LIFTS NORTH. WILL
CARRY LOWER POPS FURTHER NORTH.
OVERNIGHT LOWS RANGING FROM THE MID 50S OVER NORTHEAST COUNTIES TO
THE MID 60S IN THE LOWER WABASH VALLEY LOOK REASONABLE AND LITTLE
CHANGE WAS MADE. ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ISSUED AT 245 PM EDT SAT MAY 10 2014
FOCUS WILL CONTINUE TO BE ON THUNDERSTORM CHANCES THROUGH THE ENTIRE
SHORT TERM AS LOW PRESSURE SYSTEM GRADUALLY MIGRATES EAST FROM THE
PLAINS.
ECMWF CONTINUES TO BE THE MOST CONSISTENT OF THE MODELS REGARD
SLOWLY MOVING FRONTAL SYSTEM. ASSOCIATED COLD FRONT LOOKS LIKE IT
WILL NOT MOVE ACROSS CENTRAL INDIANA UNTIL TUESDAY AFTERNOON AND
NIGHT.
ON SUNDAY...WARM FRONT SHOULD LIFT NORTHEAST ACROSS CENTRAL INDIANA
WHICH SHOULD TRIGGER SCATTERED THUNDERSTORMS WITH MODELS ALL SHOWING
MIXED LAYER CAPES FROM 1000-2000 J/KG...INCREASED LOW LEVEL MOISTURE
AND SOME RESULTING QPF. THEN...WITH THE AREA IN THE WARM SECTOR FROM
SUNDAY NIGHT THROUGH MONDAY NIGHT...SHOULD SEE WARMER TEMPERATURES
IN THE 80S ON MONDAY PER 12Z MOS BLEND AND CONSALL. WILL STICK WITH
LOW POPS SUNDAY NIGHT THROUGH MONDAY NIGHT WITH AMPLE INSTABILITY
AND POSSIBLY LEFTOVER OUTFLOW BOUNDARIES BUT ONLY WEAK SYNOPTIC
FORCING WITH UPPER WAVES IN SOUTHWEST FLOW.
BEST CHANCE OF THUNDERSTORMS WILL BE ON TUESDAY AS THE FRONT
APPROACHES AND MOVES AT LEAST PART OF THE WAY ACROSS THE FORECAST
AREA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 245 PM EDT SAT MAY 10 2014
ENSEMBLES INDICATE A SLOWLY PROGRESSIVE NATURE TO THE MAIN UPPER
FEATURES DURING THIS PERIOD. A DEEP TROUGH THAT IS EXPECTED TO BE
OVER THE MIDWEST BY THE MIDDLE OF NEXT WEEK WILL GRADUALLY SETTLE
INTO THE GREAT LAKES/OHIO VALLEY BY NEXT WEEKEND.
SOME OF THE ENSEMBLES SUGGEST A SECONDARY WAVE OF LOW PRESSURE MAY
DEVELOP ALONG THE MAIN FRONT TOWARDS THE MIDDLE OF NEXT WEEK WHILE
OTHERS ARE QUICKER WITH THE PASSAGE OF THE FRONT. IN EITHER
CASE...IT APPEARS THE HIGHEST PRECIPITATION THREAT WILL BE TUESDAY
NIGHT INTO WEDNESDAY WITH THE PASSAGE OF THE SURFACE FRONT AND
POTENTIAL SECONDARY WAVE.
AFTER THAT...COOL AND SHOWERY CONDITIONS EXPECTED INTO NEXT WEEKEND
ASSOCIATED WITH THE INSTABILITY NEAR THE DEEP UPPER TROUGH AND ANY
POTENTIAL DISTURBANCES THAT MAY RIPPLE THROUGH IT. WILL KEEP POPS
GOING THROUGHOUT THE EXTENDED PERIOD.
&&
.AVIATION /DISCUSSION FOR 110600Z TAF ISSUANCE/...
ISSUED AT 1259 AM EDT SUN MAY 11 2014
SITES WILL START OUT VFR AND DRY WITH A FRONT ACROSS SOUTHERN
INDIANA. THIS WILL SLOWLY LIFT NORTH AS A WARM FRONT. SHOWERS AND
THUNDERSTORMS OVER CENTRAL ILLINOIS WILL MOVE IN TO THE SITES
STARTING AFTER ABOUT 8Z. UNCERTAIN HOW MUCH THUNDER WILL BE LEFT AT
THAT POINT...SO WILL INCLUDE A VCTS WITH SHOWERS. EXPECT WINDS TO BE
LIGHT AND VARIABLE FOR A FEW HOURS BUT PICK UP AGAIN SUNDAY MORNING
OUT OF THE SOUTHEAST AND THEN SOUTH BY SUNDAY AFTERNOON...AROUND 5-8
KTS IN THE MORNING THEN 10-15 KTS IN THE AFTERNOON.
MORE CHANCES FOR RAIN AND THUNDER ARE IN THE FORECAST FOR SUNDAY
AFTERNOON...BUT UNCERTAINTY IS HIGH ENOUGH TO LEAVE OUT FOR NOW AND
JUST INCLUDE A BROKEN DECK.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....JAS
AVIATION...CP
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
357 PM CDT SUN MAY 11 2014
.SYNOPSIS...
ISSUED AT 356 PM CDT SUN MAY 11 2014
12Z UA ANALYSIS HAS 850MB LOWS IN NORTHWEST MINNESOTA WITH A STRONG
850MB LOW IN WESTERN KANSAS. AN 850MB WARM FRONT RAN FROM THE KANSAS
LOW INTO SOUTHERN IOWA. A STRONG LLJ RAN FROM THE GULF COAST INTO
THE CENTRAL PLAINS. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON HAS
CONVECTION ACROSS EASTERN IOWA AND NORTHERN ILLINOIS WITH NEW
CONVECTION DEVELOPING IN THE PLAINS.
18Z SFC ANALYSIS HAS A WEAK LOW IN WESTERN WISCONSIN WITH A
DEVELOPING WARM FRONT SOUTHEAST INTO CENTRAL LAKE MICHIGAN. AN
IMPLIED LOW WAS IN SOUTHERN IOWA APPROACHING KOTM WITH ANOTHER LOW
IN WESTERN KANSAS. A FRONTAL BOUNDARY RAN FROM THE KANSAS LOW INTO
THE IOWA LOW NEAR KOTM WITH A WARM FRONT FROM NEAR KOTM NORTHEAST TO
THE WISCONSIN/ILLINOIS BORDER. DEW POINTS SOUTH OF THE FRONT WERE IN
THE 60S WITH 40S AND 50S IN THE NORTHERN PLAINS INTO THE GREAT LAKES
NORTH OF THE FRONT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 356 PM CDT SUN MAY 11 2014
BOUNDARIES FROM THE NOCTURNAL THUNDERSTORM COMPLEX INITIATED A NEW
STORM COMPLEX ALONG THE WARM FRONT IN SOUTHERN IOWA THIS MORNING.
THIS NEW STORM COMPLEX MOVED EAST NORTHEAST AND IS SLOWLY DECAYING
ACROSS THE AREA.
HOWEVER...BOUNDARIES FROM THIS STORM ALONG WITH DIURNAL HEATING HAS
INITIATED NEW DISCRETE STRONG TO SEVERE STORMS THAT WILL CONTINUE
THROUGH LATE AFTERNOON.
BASED ON SATELLITE...RADAR...AND RAP TRENDS...THERE MAY BE A BREAK
IN STORM ACTIVITY THIS EVENING AS THE NEW SEVERE STORMS CONTINUE TO
DEVELOP AND MOVE NORTHEAST WELL WEST OF THE AREA.
AFTER MIDNIGHT THE STORMS OUT WEST WILL EVOLVE UPSCALE INTO ANOTHER
NOCTURNAL THUNDERSTORM COMPLEX THAT WILL SLOWLY MOVE INTO THE
NORTHWEST THIRD OF THE AREA. ISOLATED TO SCATTERED STORMS ARE VERY
POSSIBLE AHEAD OF THIS STORM COMPLEX AS MOISTURE CONTINUES TO FEED
INTO THE AREA.
ON MONDAY THE BETTER RAIN CHANCES WILL BE OVER THE NORTHWEST HALF OF
THE AREA DURING THE MORNING. DURING THE AFTERNOON...NEW CONVECTION
IS EXPECTED TO DEVELOP AS ANOTHER DISTURBANCE ALOFT MOVES THROUGH
THE AREA. BASED ON THE POSITION OF THE MAIN FEATURES AND OVERALL
EXPECTED FORCING...SEVERE STORMS ARE POSSIBLE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 356 PM CDT SUN MAY 11 2014
MONDAY NIGHT THE MAIN COLD FRONT BEGINS MOVING THROUGH THE AREA.
CONVECTION IS EXPECTED TO BE WIDESPREAD AND MAY EVOLVE INTO A BAND
OF STRONG STORMS DURING THE EVENING HOURS. IF A BAND DOES FORM IT
WILL SLOWLY MOVE EAST OVERNIGHT.
ON TUESDAY...RAIN WILL END FROM WEST TO EAST DURING THE DAY WITH
MOST OF THE AREA BEING DRY BY MID DAY. TEMPERATURES WILL BE WELL
BELOW NORMAL.
HIGH PRESSURE MOVING THROUGH THE MIDWEST TUESDAY NIGHT WILL RESULT
IN DRY CONDITIONS WITH SEASONABLY COOL TEMPERATURES.
ON WEDNESDAY THE NEXT STORM SYSTEM MOVES NORTHEAST FROM THE SOUTHERN
PLAINS INTO THE OHIO VALLEY. THE TRENDS WITH THE MODELS HAVE BEEN TO
SLOWLY PULL THE STORM SYSTEM TO THE NORTH AND WEST.
WEDNESDAY NIGHT ON...
THERE CONTINUES TO BE DIFFERENCES BETWEEN THE GLOBAL MODELS AS TO
WHAT WILL OCCUR...BUT...ALL AGREE THAT TEMPERATURES WILL AVERAGE
BELOW NORMAL WEDNESDAY NIGHT THROUGH SUNDAY.
WEDNESDAY NIGHT/THURSDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE TO
CHANCE POPS AS THE NEXT SYSTEM MOVES UP THROUGH THE OHIO VALLEY. THE
TREND IN THE MODELS HAS BEEN TO SLOWLY BRING THE STORM FURTHER TO
THE NORTH AND WEST.
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS THURSDAY NIGHT AS THE
STORM SYSTEM EXITS THE AREA.
FRIDAY THROUGH SATURDAY THE MODEL CONSENSUS HAS MAINLY SLIGHT CHANCE
POPS FRIDAY AND SATURDAY WITH MAINLY DRY CONDITIONS FRIDAY NIGHT.
DISTURBANCES WILL CONTINUE TO ROTATE AROUND THE UPPER LOW OVER THE
GREAT LAKES PRODUCING MAINLY DIURNAL SHOWERS. IF ENOUGH CLEARING CAN
TAKE PLACE FRIDAY NIGHT AND WINDS REMAIN LIGHT...THERE MAY BE A
POTENTIAL FOR FROST.
DRY CONDITIONS SHOULD BE SEEN SATURDAY NIGHT AS HIGH PRESSURE MOVES
THROUGH THE AREA.
ON SUNDAY...THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS FOR
ROUGHLY THE WESTERN HALF OF THE AREA AS THE NEXT STORM SYSTEM MOVES
EAST FROM THE PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1210 PM CDT SUN MAY 11 2014
SHOWERS AND STORMS WILL PASS ACROSS THE TERMINALS THIS AFTERNOON
WITH PERIODS OF MVFR TO LOCAL IFR IN THE PRECIPITATION. THERE IS
A RISK OF SEVERE STORMS WITH LARGE HAIL AND DAMAGING WINDS MAINLY
SOUTH OF HWY 30. LOOKS LIKE A BREAK OR LULL IS EXPECTED FOR A TIME
THIS EVENING AS FOCUS FOR PRECIPITATION SHIFTS BACK WEST. SHOWERS AND
STORMS WILL LIKELY THEN MOVE BACK INTO PORTIONS OF THE AREA BY
LATE EVENING AND OVERNIGHT...MAINLY WEST OF THE MISSISSIPPI RIVER
DECAYING TO SHOWERS BY MID AM MONDAY. WINDS WILL BE GENERALLY
SOUTHERLY AROUND 10 KTS WITH OCCASIONAL GUSTS 20-25 KTS MAINLY
EAST CENTRAL AND SOUTHEAST IA.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1219 PM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 1019 AM CDT SUN MAY 11 2014
CURRENT STORM COMPLEX OVER WESTERN IOWA IS SLOWLY DECAYING.
HOWEVER...BOUNDARIES FROM THIS COMPLEX ARE INTERACTING WITH THE
SURFACE WARM FRONT AND GENERATING NEW CONVECTION IN SOUTHWEST
IOWA THAT IS MOVING EAST NORTHEAST.
12Z UA ANALYSIS SHOWS A SHARP MOISTURE GRADIENT ACROSS THE AREA
WITH THE 850MB WARM FRONT ROUGHLY INTO SOUTHERN IOWA. STORMS IN
SOUTHWEST IOWA SHOULD GENERALLY MOVE ALONG SAID UPPER FRONT TOWARD
THE AREA THE REMAINDER OF THE MORNING.
NOWCASTING AND VARIOUS TOOLS/TECHNIQUES INDICATE VERY LITTLE IN
THE WAY OF FORCING ACROSS THE AREA THROUGH THE REMAINDER OF THE
MORNING. SHOWERS CANNOT BE RULED OUT DEVELOPING ALONG THE 850MB
WARM FRONT WITH POSSIBLY SOME THUNDER. RAP TRENDS INDICATE THE
850MB FLOW WEAKENING THROUGH MID DAY AND BEGINNING TO BACK WHICH
WOULD RE-FOCUS NEW DEVELOPMENT WEST OF THE AREA THIS AFTERNOON.
&&
.SYNOPSIS...
ISSUED AT 228 AM CDT SUN MAY 11 2014
00Z UPPER AIR ANALYSIS AND WV IMAGERY SHOWED STRONG SHORTWAVE
LIFTING EAST NORTHEAST INTO MINNESOTA WHILE ANOTHER WAVE WAS
ROUNDING THE BASE OF THE TROUGH OVER THE SOUTHWEST CONUS. GULF
MOISTURE FEED ALSO BEGINNING TO DEVELOP ACROSS THE SOUTHERN PLAINS
WITH 10C 85H DEWPOINTS AS FAR NORTH AS KANSAS CITY AT 00Z. AT THE
SURFACE...A FRONTAL BOUNDARY EXTENDED FROM NORTHWEST MISSOURI INTO
SOUTHERN ILLINOIS WITH CONVECTION MAINLY CONFINED ON THE COLD SIDE
OF THE BOUNDARY IN EASTERN MISSOURI AND SOUTHERN ILLINOIS. LATEST
RADAR IMAGERY SHOWED THE STORM CELL THAT DEVELOPED OVER IOWA
COUNTY AROUND MIDNIGHT HAS SINCE MOVED EAST AND DIMINISHED.
AT 2AM...TEMPERATURES WERE IN THE UPPER 50S TO LOWER 60S WITH
DEWPOINTS IN THE MIDDLE 40S TO UPPER 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 228 AM CDT SUN MAY 11 2014
FORECAST FOCUS REMAINS ON SEVERE WEATHER POTENTIAL MAINLY THIS
AFTERNOON AND INTO THE OVERNIGHT HOURS.
TODAY...CONVECTION CURRENTLY DEVELOPING OVER SOUTHERN NEBRASKA
AND NORTHERN KANSAS TO LIFT EAST NORTHEAST AND BECOME MORE
WIDESPREAD OVER CENTRAL IOWA AS LLJ STRENGTHENS THIS MORNING AND
WHERE BETTER UPPER LEVEL DIVERGENCE WILL BE FOUND. LATEST HRR MODEL
TRENDS SHOW SCATTERED SHOWERS AND STORMS DEVELOPING MAINLY ACROSS
THE NORTHWEST THIRD OF THE CWA BY EARLY AFTERNOON. WARMING AROUND
925MB SHOULD HELP LIMIT ANY STORM DEVELOPMENT UNTIL THE AFTERNOON OVER
THE CWA. ANY STORM THAT DEVELOPS NORTH OF THE WARM FRONT COULD
BECOME SEVERE WITH MAIN THREATS LARGE HAIL AND DAMAGING WINDS.
DEEP MIXING AND STRONG WAA ALOFT WILL ALLOW FOR HIGHS UPPER 70S
NORTH TO THE MIDDLE 80S IN THE SOUTH BY THE AFTERNOON. INCREASING
DEWPOINTS INTO THE 60S WILL ALSO RESULT IN SOMEWHAT HUMID
CONDITIONS.
TONIGHT...WARM FRONT TO LIFT NORTH OUT OF THE CWA BY 00Z MONDAY. A
COLD FRONT WILL SLOWLY MAKE ITS WAY ACROSS IOWA. THERE IS A
POSSIBLY THAT THERE MAY BE SEVERAL HOURS LATE IN THE EVENING
WHERE THE REGION WILL BE DRY IN THE WARM SECTOR AND WILL PASS ON
THIS CONCERN TO THE NEXT SHIFT. AHEAD OF COLD FRONT MOVING OVER IOWA
...STRONG SOUTHERLY FLOW WILL CONTINUE TO USHER IN RICH GULF
MOISTURE WITH MODEL PWATS IN EXCESS OF 1.6 INCHES OVER CENTRAL
IOWA AND THE NORTHWEST SECTIONS OF THE CWA. EXPECT SUPERCELLS TO
FORM AHEAD OF FRONT OVER CENTRAL IOWA AND PROPAGATE EAST INTO THE
CWA EARLY MONDAY IN A VERY FAVORABLE ENVIRONMENT WITH SBCAPES IN
EXCESS OF 3000 J/KG AND 0-6KM SHEAR VALUES AROUND 40 KTS. MAIN
SEVERE THREATS AT THIS TIME WILL BE VERY LARGE HAIL AND DAMAGING
WINDS. LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE. ANOTHER VERY
MILD NIGHT IN STORE FOR THE REGION WITH LOWS ONLY IN THE MIDDLE
60S TO LOWER 70S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 228 AM CDT SUN MAY 11 2014
EARLY MONDAY A DEEP UPPER TROF WILL BE LOCATED JUST EAST OF THE
ROCKIES WITH A SURFACE COLD FRONT FROM EASTERN MINNESOTA THROUGH
WESTERN IOWA. THE UPPER TROF AND COLD FRONT WILL MOVE SLOWLY EAST
MONDAY. THE COLD FRONT SHOULD MOVE THROUGH THE MID MISSISSIPPI
VALLEY FROM LATE MONDAY AFTERNOON THROUGH MONDAY EVENING. THE LATE
DAY AND EVENING TIMING OF THE COLD FRONTAL PASSAGE WILL FAVOR
ANOTHER RISK OF SEVERE THUNDERSTORMS FOR THE ENTIRE AREA SINCE THE
AIRMASS AHEAD OF THE FRONT WILL BE QUITE MOIST AND WILL HAVE PLENTY
OF TIME TO HEAT/DESTABILIZE PRIOR TO THE FROPA. HAVE HELD POPS IN
THE CHANCE CATEGORY MONDAY MORNING WITH LITTLE INDICATION OF
FORCING TO SUPPORT THUNDERSTORM DEVELOPMENT. CATEGORICAL POPS
WERE SPREAD EAST ACROSS THE AREA WITH THE BETTER FORCING
ASSOCIATED WITH THE COLD FRONT DURING THE AFTERNOON AND OVERNIGHT
HOURS. THE SEVERE THREAT SHOULD BE DURING THE AFTERNOON AND
EVENING AND CONSIST OF MAINLY LARGE HAIL AND DAMAGING WINDS. THERE
WILL BE LITTLE DIRECTIONAL SHEAR IN THE DEEP SOUTHERLY FLOW AHEAD
OF THE UPPER TROF TO SUPPORT A SIGNIFICANT TORNADIC THREAT. THE
SLOW MOVEMENT OF THE FRONT AND UPPER TROF ALONG WITH PW/S
EXCEEDING 1.5 INCHES WILL FAVOR QPF AMOUNTS OF AN INCH PLUS BY
TUESDAY MORNING NEAR AND EAST OF THE MISSISSIPPI RIVER.
THE LONGER RANGE MODELS ARE PRETTY CONSISTENT ON THE 00Z RUN OF
MOVING THE UPPER TROF INTO THE MISSISSIPPI VALLEY BY MID WEEK AND
CLOSING AN UPPER LOW OFF OVER THE NORTH CENTRAL STATES OR THE
WESTERN GREAT LAKES. THE UPPER LOW THEN LINGERS OVER THE AREA
THROUGH THE END OF THE WEEK. GIVEN THIS SCENARIO THE DEEP CYCLONIC
FLOW WITH THE UPPER LOW WILL KEEP SHOWERY AND COOL WEATHER OVER THE
REGION FOR THE REST OF THE WEEK. BY THURSDAY OR FRIDAY BOTH THE
ECMWF AND GFS SHOW A REINFORCING SHOT OF COOLER AIR MOVING SOUTH
INTO THE MID MISSISSIPPI VALLEY WITH H8 TEMPS AT OR JUST BELOW 0C
SPREADING OVER THE REGION. IF THIS VERIFIES AND THEN WE COULD SEE
LOWS TEMPERATURES IN THE MID TO UPPER 30S...OR COLDER GIVEN GOOD
RADIATIONAL COOLING CONDITIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1210 PM CDT SUN MAY 11 2014
SHOWERS AND STORMS WILL PASS ACROSS THE TERMINALS THIS AFTERNOON
WITH PERIODS OF MVFR TO LOCAL IFR IN THE PRECIPITATION. THERE IS
A RISK OF SEVERE STORMS WITH LARGE HAIL AND DAMAGING WINDS MAINLY
SOUTH OF HWY 30. LOOKS LIKE A BREAK OR LULL IS EXPECTED FOR A TIME
THIS EVENING AS FOCUS FOR PRECIPITATION SHIFTS BACK WEST. SHOWERS AND
STORMS WILL LIKELY THEN MOVE BACK INTO PORTIONS OF THE AREA BY
LATE EVENING AND OVERNIGHT...MAINLY WEST OF THE MISSISSIPPI RIVER
DECAYING TO SHOWERS BY MID AM MONDAY. WINDS WILL BE GENERALLY
SOUTHERLY AROUND 10 KTS WITH OCCASIONAL GUSTS 20-25 KTS MAINLY
EAST CENTRAL AND SOUTHEAST IA.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...GROSS
SHORT TERM...GROSS
LONG TERM...DLF
AVIATION...05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1026 AM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 1019 AM CDT SUN MAY 11 2014
CURRENT STORM COMPLEX OVER WESTERN IOWA IS SLOWLY DECAYING.
HOWEVER...BOUNDARIES FROM THIS COMPLEX ARE INTERACTING WITH THE
SURFACE WARM FRONT AND GENERATING NEW CONVECTION IN SOUTHWEST
IOWA THAT IS MOVING EAST NORTHEAST.
12Z UA ANALYSIS SHOWS A SHARP MOISTURE GRADIENT ACROSS THE AREA
WITH THE 850MB WARM FRONT ROUGHLY INTO SOUTHERN IOWA. STORMS IN
SOUTHWEST IOWA SHOULD GENERALLY MOVE ALONG SAID UPPER FRONT TOWARD
THE AREA THE REMAINDER OF THE MORNING.
NOWCASTING AND VARIOUS TOOLS/TECHNIQUES INDICATE VERY LITTLE IN
THE WAY OF FORCING ACROSS THE AREA THROUGH THE REMAINDER OF THE
MORNING. SHOWERS CANNOT BE RULED OUT DEVELOPING ALONG THE 850MB
WARM FRONT WITH POSSIBLY SOME THUNDER. RAP TRENDS INDICATE THE
850MB FLOW WEAKENING THROUGH MID DAY AND BEGINNING TO BACK WHICH
WOULD RE-FOCUS NEW DEVELOPMENT WEST OF THE AREA THIS AFTERNOON.
&&
.SYNOPSIS...
ISSUED AT 228 AM CDT SUN MAY 11 2014
00Z UPPER AIR ANALYSIS AND WV IMAGERY SHOWED STRONG SHORTWAVE
LIFTING EAST NORTHEAST INTO MINNESOTA WHILE ANOTHER WAVE WAS
ROUNDING THE BASE OF THE TROUGH OVER THE SOUTHWEST CONUS. GULF
MOISTURE FEED ALSO BEGINNING TO DEVELOP ACROSS THE SOUTHERN PLAINS
WITH 10C 85H DEWPOINTS AS FAR NORTH AS KANSAS CITY AT 00Z. AT THE
SURFACE...A FRONTAL BOUNDARY EXTENDED FROM NORTHWEST MISSOURI INTO
SOUTHERN ILLINOIS WITH CONVECTION MAINLY CONFINED ON THE COLD SIDE
OF THE BOUNDARY IN EASTERN MISSOURI AND SOUTHERN ILLINOIS. LATEST
RADAR IMAGERY SHOWED THE STORM CELL THAT DEVELOPED OVER IOWA
COUNTY AROUND MIDNIGHT HAS SINCE MOVED EAST AND DIMINISHED.
AT 2AM...TEMPERATURES WERE IN THE UPPER 50S TO LOWER 60S WITH
DEWPOINTS IN THE MIDDLE 40S TO UPPER 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 228 AM CDT SUN MAY 11 2014
FORECAST FOCUS REMAINS ON SEVERE WEATHER POTENTIAL MAINLY THIS
AFTERNOON AND INTO THE OVERNIGHT HOURS.
TODAY...CONVECTION CURRENTLY DEVELOPING OVER SOUTHERN NEBRASKA
AND NORTHERN KANSAS TO LIFT EAST NORTHEAST AND BECOME MORE
WIDESPREAD OVER CENTRAL IOWA AS LLJ STRENGTHENS THIS MORNING AND
WHERE BETTER UPPER LEVEL DIVERGENCE WILL BE FOUND. LATEST HRR MODEL
TRENDS SHOW SCATTERED SHOWERS AND STORMS DEVELOPING MAINLY ACROSS
THE NORTHWEST THIRD OF THE CWA BY EARLY AFTERNOON. WARMING AROUND
925MB SHOULD HELP LIMIT ANY STORM DEVELOPMENT UNTIL THE AFTERNOON OVER
THE CWA. ANY STORM THAT DEVELOPS NORTH OF THE WARM FRONT COULD
BECOME SEVERE WITH MAIN THREATS LARGE HAIL AND DAMAGING WINDS.
DEEP MIXING AND STRONG WAA ALOFT WILL ALLOW FOR HIGHS UPPER 70S
NORTH TO THE MIDDLE 80S IN THE SOUTH BY THE AFTERNOON. INCREASING
DEWPOINTS INTO THE 60S WILL ALSO RESULT IN SOMEWHAT HUMID
CONDITIONS.
TONIGHT...WARM FRONT TO LIFT NORTH OUT OF THE CWA BY 00Z MONDAY. A
COLD FRONT WILL SLOWLY MAKE ITS WAY ACROSS IOWA. THERE IS A
POSSIBLY THAT THERE MAY BE SEVERAL HOURS LATE IN THE EVENING
WHERE THE REGION WILL BE DRY IN THE WARM SECTOR AND WILL PASS ON
THIS CONCERN TO THE NEXT SHIFT. AHEAD OF COLD FRONT MOVING OVER IOWA
...STRONG SOUTHERLY FLOW WILL CONTINUE TO USHER IN RICH GULF
MOISTURE WITH MODEL PWATS IN EXCESS OF 1.6 INCHES OVER CENTRAL
IOWA AND THE NORTHWEST SECTIONS OF THE CWA. EXPECT SUPERCELLS TO
FORM AHEAD OF FRONT OVER CENTRAL IOWA AND PROPAGATE EAST INTO THE
CWA EARLY MONDAY IN A VERY FAVORABLE ENVIRONMENT WITH SBCAPES IN
EXCESS OF 3000 J/KG AND 0-6KM SHEAR VALUES AROUND 40 KTS. MAIN
SEVERE THREATS AT THIS TIME WILL BE VERY LARGE HAIL AND DAMAGING
WINDS. LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE. ANOTHER VERY
MILD NIGHT IN STORE FOR THE REGION WITH LOWS ONLY IN THE MIDDLE
60S TO LOWER 70S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 228 AM CDT SUN MAY 11 2014
EARLY MONDAY A DEEP UPPER TROF WILL BE LOCATED JUST EAST OF THE
ROCKIES WITH A SURFACE COLD FRONT FROM EASTERN MINNESOTA THROUGH
WESTERN IOWA. THE UPPER TROF AND COLD FRONT WILL MOVE SLOWLY EAST
MONDAY. THE COLD FRONT SHOULD MOVE THROUGH THE MID MISSISSIPPI
VALLEY FROM LATE MONDAY AFTERNOON THROUGH MONDAY EVENING. THE LATE
DAY AND EVENING TIMING OF THE COLD FRONTAL PASSAGE WILL FAVOR
ANOTHER RISK OF SEVERE THUNDERSTORMS FOR THE ENTIRE AREA SINCE THE
AIRMASS AHEAD OF THE FRONT WILL BE QUITE MOIST AND WILL HAVE PLENTY
OF TIME TO HEAT/DESTABILIZE PRIOR TO THE FROPA. HAVE HELD POPS IN
THE CHANCE CATEGORY MONDAY MORNING WITH LITTLE INDICATION OF
FORCING TO SUPPORT THUNDERSTORM DEVELOPMENT. CATEGORICAL POPS
WERE SPREAD EAST ACROSS THE AREA WITH THE BETTER FORCING
ASSOCIATED WITH THE COLD FRONT DURING THE AFTERNOON AND OVERNIGHT
HOURS. THE SEVERE THREAT SHOULD BE DURING THE AFTERNOON AND
EVENING AND CONSIST OF MAINLY LARGE HAIL AND DAMAGING WINDS. THERE
WILL BE LITTLE DIRECTIONAL SHEAR IN THE DEEP SOUTHERLY FLOW AHEAD
OF THE UPPER TROF TO SUPPORT A SIGNIFICANT TORNADIC THREAT. THE
SLOW MOVEMENT OF THE FRONT AND UPPER TROF ALONG WITH PW/S
EXCEEDING 1.5 INCHES WILL FAVOR QPF AMOUNTS OF AN INCH PLUS BY
TUESDAY MORNING NEAR AND EAST OF THE MISSISSIPPI RIVER.
THE LONGER RANGE MODELS ARE PRETTY CONSISTENT ON THE 00Z RUN OF
MOVING THE UPPER TROF INTO THE MISSISSIPPI VALLEY BY MID WEEK AND
CLOSING AN UPPER LOW OFF OVER THE NORTH CENTRAL STATES OR THE
WESTERN GREAT LAKES. THE UPPER LOW THEN LINGERS OVER THE AREA
THROUGH THE END OF THE WEEK. GIVEN THIS SCENARIO THE DEEP CYCLONIC
FLOW WITH THE UPPER LOW WILL KEEP SHOWERY AND COOL WEATHER OVER THE
REGION FOR THE REST OF THE WEEK. BY THURSDAY OR FRIDAY BOTH THE
ECMWF AND GFS SHOW A REINFORCING SHOT OF COOLER AIR MOVING SOUTH
INTO THE MID MISSISSIPPI VALLEY WITH H8 TEMPS AT OR JUST BELOW 0C
SPREADING OVER THE REGION. IF THIS VERIFIES AND THEN WE COULD SEE
LOWS TEMPERATURES IN THE MID TO UPPER 30S...OR COLDER GIVEN GOOD
RADIATIONAL COOLING CONDITIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 637 AM CDT SUN MAY 11 2014
GENERALLY VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE
PERIOD. A WARM FRONT WILL LIFT NORTH OVER THE REGION TODAY
PROVIDING A FOCUS FOR STORM DEVELOPMENT. DAYTIME HEATING COMBINED
WITH LOW LEVEL CONVERGENCE WILL ALLOW FOR ELEVATED SHOWERS AND
THUNDERSTORMS TO DEVELOP GENERALLY ALONG AND NORTH OF THE FRONT
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS. SOME OF THESE
STORMS MAY BECOME SEVERE WITH LARGE HAIL AND STRONG WINDS. HAVE
INCLUDED TS GROUPS FOR ALL BUT THE BRL TERMINAL. WARM FRONT TO BE
NORTH OF THE AREA BY 00Z/12 WITH ADDITIONAL STORM DEVELOPMENT
EXPECTED LATE IN THE TAF PERIOD AS COLD FRONT PUSHES EAST ACROSS
IOWA.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...GROSS
SHORT TERM...GROSS
LONG TERM...DLF
AVIATION...GROSS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
257 PM CDT Sun May 11 2014
...Update to short term...
.SHORT TERM...(This evening through Monday)
ISSUED AT 254 PM CDT SUN MAY 11 2014
Abbreviated AFD due to ongoing warning operations.
From my mesoscale discussion at 1:53 PM...
(Convection already has developed by the same mesoscale assessments
still applies)
Special 18Z KDDC raob shows just a little bit of CIN remaining. Won`t
be long before convection develops. Visible satellite imagery shows
increasing cumulus along the dryline/front. HRRR indicates thunderstorms
developing along the Highway 283 corridor in the 3-4 pm time range.
Right moving Bunkers shows propagation vectors northeasterly at 45 kt.
Initial threat will be large hail (up to 20! on the LHP using NAM thermodynamic
and kinematic variables) and damaging outflow winds. There is an small
window of tornadic opportunity between 7 and 9 pm as low level winds
back across central/south central-Kansas but all the big wedge/strong tornadoes
should remain across Nebraska/Iowa with just small spin ups/weak tornadoes
in our area, if possible.
Convection will depart the area tonight. Some light showers will be
possible on the backside of the departing wave. It will be windy post
frontal through tomorrow. Right now conditions look borderline for wind
advisory criteria.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 122 PM CDT SUN MAY 11 2014
An upper level longwave trough will be moving across the Plains on
Tuesday but should be dry with the moisture pushed east of the area.
Colder temperatures will accompany this trough with overnight lows
on Monday night into the mid 30s and highs on Tuesday in the low to
mid 60s. Strong northwest winds will mix down to the surface with
winds of 15 to 30 mph and partly cloudy skies.
For Wednesday into Thursday, dry northwesterly upper level flow will
follow with highs slowly warming into the upper 60s and 70s.
Wednesday morning may be the coldest morning with light winds and
lows in the low to mid 30s.
For Friday and Saturday, a few showers and thunderstorms may form as
as some upper air disturbances in northwest flow aloft interact with
increasing upslope moisture. Lows will be in the 40s and highs
around 70 to 75.
On Sunday, of next week, upper level ridging is forecast with dry
and warmer temps around 80.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1101 AM CDT SUN MAY 11 2014
VFR conditions through much of the TAF. Main exception is for KDDC/KHYS
this afternoon/eve, where convection could create temporary MVFR cigs in
heavy thunderstorm activity. Southerly winds 20-30 kt will become
northerly 15-28 kt in the wake of a fropa later tonight.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 56 35 63 / 20 10 0 0
GCK 42 53 34 62 / 20 20 0 0
EHA 42 55 34 61 / 10 10 0 10
LBL 44 58 34 62 / 10 10 0 10
HYS 46 53 35 63 / 80 30 0 0
P28 56 63 40 66 / 80 20 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 8 PM CDT this evening FOR KSZ046-065-066-
078>081-088>090.
RED FLAG WARNING until 9 PM CDT this evening FOR KSZ074>076-
084>086.
&&
$$
SHORT TERM...Sugden
LONG TERM...Kruse
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
153 PM CDT Sun May 11 2014
...Update to mesoscale discussion...
.MESOSCALE DISCUSSION...
ISSUED AT 153 PM CDT SUN MAY 11 2014
Special 18Z KDDC raob shows just a little bit of CIN remaining. Won`t
be long before convection develops. Visible satellite imagery shows
increasing cumulus along the dryline/front. HRRR indicates thunderstorms
developing along the Highway 283 corridor in the 3-4 pm time range.
Right moving Bunkers shows propagation vectors northeasterly at 45 kt.
Initial threat will be large hail (up to 20! on the LHP using NAM thermodynamic
and kinematic variables) and damaging outflow winds. There is an small
window of tornadic opportunity between 7 and 9 pm as low level winds
back across central/south central-Kansas but all the big wedge/strong tornadoes
should remain across Nebraska/Iowa with just small spin ups/weak tornadoes
in our area, if possible.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 200 AM CDT SUN MAY 11 2014
Thunderstorms are likely across central and eastern portions of
southwest Kansas today as an upper level trough digs further
southeast into the Four Corners Region. As the upper level system
approaches, short range models indicate an upper level jet
intensifying as it lifts out of the trough axis northeast across the
Western High Plains. Meanwhile, deep low level moisture will
continue to lift northward into south central and eastern portions
of southwest Kansas ahead of a sharpening dryline this afternoon.
While dynamic support becomes increasingly favorable during the
afternoon, thunderstorms are expected to develop along and ahead of
a cold front as it surges southeastward through western Kansas,
slamming into the dryline while capping continues to erode. Based
on NAM/GFS model soundings, the potential for severe weather exists
with steep lapse rates developing and SBCAPE values in excess of
2500 J/KG ahead of the dryline. Ample deep layer shear and favorable
low level shear will support increased tornado potential across
central and possibly south central Kansas toward Sunday evening.
Otherwise, golf ball to tennis ball size hail and damaging winds in
excess of 60 mph will be possible with any storm that becomes severe.
Strong southerly winds are expected to develop across central and
portions of southwest Kansas this afternoon as surface low pressure
deepens across extreme southwest Kansas and the panhandles of
Oklahoma and Texas. This will create a tight pressure gradient
across the aforementioned area resulting in stronger southerly
winds. Additionally, the NAM and GFS show H85 winds of 40 to 50kt
setting up here as well. As the cap erodes this afternoon, these
winds are expected to mix down to the surface enhancing wind
strength. Therefore, a wind advisory will be issued for the affected
area this afternoon/evening.
The warming trend continues today as surface low pressure lee of the
Rockies strengthens increasing a strong southerly flow into central
and southwest Kansas. This will draw warmer air into central and
southwest Kansas ahead of an approaching cold front. The NAM/GFS
show H85 temperatures ranging from the mid to upper 20s(C) across
the area. Considering the cold front is not expected move in until
mid to late afternoon, highs are likely to reach the upper 80s(F) to
the lower 90s(F) in across central and much of southwest Kansas this
afternoon. Look for lows down into the 40s(F) across west central
Kansas to the 50s(F) in south central Kansas tonight.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 122 PM CDT SUN MAY 11 2014
An upper level longwave trough will be moving across the Plains on
Tuesday but should be dry with the moisture pushed east of the area.
Colder temperatures will accompany this trough with overnight lows
on Monday night into the mid 30s and highs on Tuesday in the low to
mid 60s. Strong northwest winds will mix down to the surface with
winds of 15 to 30 mph and partly cloudy skies.
For Wednesday into Thursday, dry northwesterly upper level flow will
follow with highs slowly warming into the upper 60s and 70s.
Wednesday morning may be the coldest morning with light winds and
lows in the low to mid 30s.
For Friday and Saturday, a few showers and thunderstorms may form as
as some upper air disturbances in northwest flow aloft interact with
increasing upslope moisture. Lows will be in the 40s and highs
around 70 to 75.
On Sunday, of next week, upper level ridging is forecast with dry
and warmer temps around 80.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1101 AM CDT SUN MAY 11 2014
VFR conditions through much of the TAF. Main exception is for KDDC/KHYS
this afternoon/eve, where convection could create temporary MVFR cigs in
heavy thunderstorm activity. Southerly winds 20-30 kt will become
northerly 15-28 kt in the wake of a fropa later tonight.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 55 35 63 / 30 10 0 0
GCK 43 52 34 62 / 20 20 0 0
EHA 43 54 34 61 / 10 10 0 10
LBL 45 56 34 62 / 10 10 0 10
HYS 45 54 35 63 / 60 30 0 0
P28 52 62 40 66 / 80 10 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 8 PM CDT this evening FOR KSZ046-065-066-
078>081-088>090.
RED FLAG WARNING until 9 PM CDT this evening FOR KSZ074>076-
084>086.
&&
$$
MESOSCALE...Sugden
SHORT TERM...JJohnson
LONG TERM...Kruse
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS WICHITA KS
637 AM CDT SUN MAY 11 2014
...UPDATED FOR 12Z AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 329 AM CDT SUN MAY 11 2014
FORECAST HIGHLIGHTS FOCUS AROUND SEVERE THUNDERSTORMS LATE THIS
AFTERNOON THROUGH EVENING GENERALLY NORTHWEST OF THE KS TURNPIKE.
STRONG 850-700MB WARM/MOIST ADVECTION ON NOSE OF 50-60 KT LOW-
LEVEL JET IS CURRENTLY PROMOTING NUMEROUS ELEVATED THUNDERSTORMS
TO ERUPT OVER NORTHERN/NORTHEAST KS AND SOUTHERN NEBRASKA.
THINKING ADDITIONAL DEVELOPMENT SOUTH OF THIS CURRENT ACTIVITY IS
UNLIKELY EARLY THIS MORNING GIVEN STOUT ELEVATED MIXED LAYER
BUILDING IN FROM THE SOUTH.
ATTENTION THEN TURNS TO THUNDERSTORM CHANCES LATE THIS AFTERNOON
THROUGH TONIGHT...AS A STRONG COLD FRONT SURGES SOUTHEAST INTO THE
AREA. LATEST GUIDANCE HAS SLOWED DOWN THE FRONTAL PASSAGE BY QUITE
A BIT...AND AS SUCH HAVE SLOWED DOWN EASTWARD MARCH OF
THUNDERSTORMS THROUGH TONIGHT. BEST CHANCES BEFORE MIDNIGHT WILL
BE GENERALLY NORTHWEST OF THE KS TURNPIKE...WITH THOSE CHANCES
GRADUALLY SHIFTING SOUTHEAST AFTER MIDNIGHT. GIVEN STRONG
AFTERNOON HEATING AND STRONG FRONTAL CONVERGENCE AMIDST 60S
DEWPOINTS...THUNDERSTORMS SHOULD DEVELOP RAPIDLY BY MID-LATE
AFTERNOON NORTHWEST OF GREAT BEND--SALINA. AMPLE INSTABILITY/DEEP
LAYER SHEAR WILL PROMOTE LONG-LIVED SUPERCELL STORMS...ESPECIALLY
EARLY ON...CAPABLE OF VERY LARGE HAIL/DAMAGING WINDS AND PERHAPS A
FEW TORNADOES...ALTHOUGH SOMEWHAT HIGHER CLOUD BASES AND THE
POTENTIAL FOR STORMS TO GO LINEAR QUICKLY SHOULD PRECLUDE A
WIDESPREAD TORNADO THREAT. AS STRONG FRONTAL FORCING CONTINUES TO
INCH SOUTHEAST...STORMS WILL LIKELY TRANSITION TO A SQUALL
LINE/BROKEN LINE SEGMENTS DURING THE EVENING...WITH A CONTINUED
THREAT FOR LARGE HAIL/DAMAGING WINDS. THE TORNADO THREAT SHOULD
CONTINUE WELL INTO THE EVENING...GIVEN LOWERING CLOUD BASES AND
STRENGTHENING LOW-LEVEL SHEAR...ESPECIALLY FOR ANY SOUTHERN-MOST
STORM AT THE END OF A LINE AND/OR A STORM THAT IS ABLE TO REMAIN
DISCRETE. OVERALL SEVERE THREAT WILL LIKELY WANE GENERALLY AFTER
MIDNIGHT...ALTHOUGH LOCALLY HEAVY RAIN THREAT WILL CONTINUE GIVEN
MID/UPPER FLOW PARALLEL TO THE COLD FRONT...SUPPORTING TRAINING
STORMS THROUGH THIS ENTIRE EVENT.
THUNDERSTORM CHANCES WILL CONTINUE GENERALLY OVER EASTERN KS
MONDAY. THE LATEST NAM HAS REALLY SLOWED THE FRONT`S EASTWARD
PROGRESSION...WHICH WOULD SUPPORT THE POTENTIAL FOR STRONG/SEVERE
STORMS MONDAY AFTERNOON OVER SOUTHEAST KS...ALTHOUGH THE
LIKELIHOOD OF WIDESPREAD CLOUDS MAY TEND TO LIMIT OVERALL
INSTABILITY. GFS/ECMWF BLOW THE FRONT THROUGH QUICKER ON
MONDAY...WHICH WOULD TEND TO PRECLUDE A SEVERE THREAT. GIVEN THE
EVOLUTION OF THIS SYSTEM AS OF LATE...WOULDN`T BE SURPRISED IF THE
SLOWER NAM VERIFIES.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 329 AM CDT SUN MAY 11 2014
NO MAJOR CHANGES FROM PREVIOUS FORECAST/THINKING. LONGWAVE TROUGH
ACROSS THE CENTRAL US AT START OF THE PERIOD WILL GRADUALLY
ROTATE/MOVE NE BY SAT. DIFFERENCES BETWEEN GFS/ECMWF BECOME MORE
PRONOUNCED LATE IN THE PERIOD...WITH THE ECMWF NOT AS DEEP WITH
UPPER LOW AND MORE RIDGING ACROSS THE PLAINS. BOTH MODELS HOWEVER
BACKDOOR FRONT INTO AREA ON FRI/SAT. BOTH MODELS ALSO CONTINUE THE
TREND TO DRIBBLE PRECIPITATION OUT WITH VARIOUS RIPPLES IN THE
NORTHWEST FLOW. GIVEN SUCH WEAK IMPULSES AND DIFFICULTY IN TIMING
THEM ACCURATELY IN NW FLOW...WILL CONTINUE THE DRY FORECAST FOR
NOW. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGHOUT THE PERIOD.
-HOWERTON
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 633 AM CDT SUN MAY 11 2014
TOUGH AVIATION FORECAST WITH MVFR CEILINGS THIS MORNING AND TIMING
OF STRONG/SEVERE CONVECTION THIS EVENING AND OVERNIGHT. ANTICIPATE
CEILINGS MAY DECEASE FOR THE FIRST HOUR OR TWO OF FORECAST...BUT
HEATING/MIXING SHOULD CAUSE CLOUDS TO DECREASE/RISE FOR MOST
SITES BY MID MORNING. AXIS OF HIGHEST MOISTURE...KICT-KSLN...MAY
SEE BROKEN VFR CONDITIONS FOR MOST OF THE DAY. VERY GUSTY WINDS
ARE LIKELY THROUGHOUT THE DAY AND INTO THE EVENING AHEAD OF THE
FRONT. TIMING OF FRONT REMAINS PROBLEMATIC. RECENT MODEL RUNS
SUGGEST A BIT QUICKER FRONTAL PASSAGE...SOMEWHERE BETWEEN
YESTERDAYS VERY FAST SOLUTIONS AND THE VERY SLOW 0000 UTC
SOLUTIONS. LATEST HRRR AND 0600 UTC NAM WERE USED FOR TIMING WITH
MINOR ADJUSTMENTS. THIS PUTS CONVECTION INTO KRSL AROUND 21-22
UTC...KICT 06-07 UTC AND KCNU AROUND 08-09 UTC. CONVECTION AT KCNU
WILL BEGIN WELL AHEAD OF THE FRONT. MVFR CEILINGS ARE LIKELY
BEHIND THE FRONT GIVEN SIGNIFICANT COLD AIR ADVECTION AND
LINGERING MOISTURE. -HOWERTON
&&
.FIRE WEATHER...
ISSUED AT 329 AM CDT SUN MAY 11 2014
STRONG/GUSTY SOUTH WINDS IN CONCERT WITH WARM/HOT TEMPERATURES
WILL LEAD TO VERY HIGH TO EXTREME GRASSLAND FIRE DANGER TODAY FOR
GRASSES AT LEAST 85-90 PERCENT CURED. CONSEQUENTLY...WENT WITH A
RED FLAG WARNING FROM LATE MORNING INTO THE EVENING OVER CENTRAL
/SOUTH-CENTRAL KS. SPRING GREEN-UP IS A BIT FURTHER ALONG
GENERALLY EAST OF THE KS TURNPIKE...HENCE NO RED FLAG WARNING
THERE. NUMEROUS THUNDERSTORMS WILL PROGRESS SOUTHEAST ACROSS THE
AREA THIS EVENING--TONIGHT ALONG A STRONG COLD FRONT. MUCH COOLER
AND BREEZY WEATHER ANTICIPATED MONDAY.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 90 59 66 42 / 10 70 40 10
HUTCHINSON 91 55 61 41 / 40 70 30 10
NEWTON 89 58 64 41 / 20 80 40 10
ELDORADO 87 63 66 42 / 10 70 60 10
WINFIELD-KWLD 89 66 69 42 / 10 60 60 10
RUSSELL 92 48 55 38 / 60 70 20 10
GREAT BEND 91 49 56 38 / 70 80 20 10
SALINA 91 54 59 40 / 50 80 30 10
MCPHERSON 90 55 60 41 / 40 80 30 10
COFFEYVILLE 88 70 74 47 / 10 40 70 40
CHANUTE 87 69 74 45 / 10 50 60 30
IOLA 86 68 74 45 / 10 50 60 30
PARSONS-KPPF 88 70 74 46 / 10 50 70 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM CDT THIS EVENING
FOR KSZ032-033-047>053-067>072-082-083-091>096-098>100.
RED FLAG WARNING FROM NOON TODAY TO 8 PM CDT THIS EVENING FOR
KSZ032-033-047>052-067-068-082-083-091.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
418 PM CDT Sun May 11 2014
.SHORT TERM...(Tonight through Tuesday night)
Issued at 317 PM CDT SUN MAY 11 2014
Pockets of surface-based instability continue to expand over the
WFO PAH CWA this afternoon, aided by decent insolation and weak to
moderate directional shear (25-35 knots) aloft (as evidenced by
the anvil rain plumes oriented from northwest to southeast). The
old cold pool has eroded over southeast IL and southwest IN from
the morning convection, so distinct theta-e gradients are in
place. Given the GOES Water Vapor imagery, the moisture gradient
aloft implies a gradient in lapse rates as well, helping to
enhance updrafts. (This is evidenced by the newly organized storms
with hail in Southeast IL).
The 12km RUC also suggests that the expended CAPE along and north
of the implied surface warm frontal reflection arcing from
northwest to southeast through southeast Illinois into northwest
Kentucky. Further expenditure of CAPE through 01z suggests that
the pool of convective instability should drop markedly. In
addition, model heights are expected to rise this evening with a
subtle change in balance takes place between the eastern U.S. ridge
and the center of the sharpening trough over Western Nebraska.
Expect that rain chances will be essentially nil over the entire
WFO PAH CWA by midnight, as the warm frontal boundary moves well
north of the area and shear decreases with time.
As mentioned in yesterday`s discussion, channeled vorticity along
the eastern limb of the trough near the inflection point between
the trough/ridge circulation (cyclonic/anticyclonic flow) will aid
in creating some lift in advance of an approaching moisture plume
from the Gulf of Mexico around daybreak on Monday. This transition
zone for convection will move slowly east through Monday
afternoon, as the main trough actually sharpens and becomes
slightly negatively tilted west of Iowa and Missouri Monday night
into Tuesday morning.
By 09z (4 am CDT) Tuesday morning, the cold front associated with
this trough is expected to move into western sections of the WFO
PAH Forecast area (Southwest IL/Southeast MO). By late evening
Monday and into early Tuesday, the coverage of showers and
thunderstorms should pick up significantly. It is at this time,
that my concern for heavy rain potential will increase, with the
potential for at least minor flooding by daybreak on Tuesday over
parts of Southeast Missouri northeast to the Mississippi River.
QPF values in excess of two inches would not be out of the
question during that time period.
The 12km NAM-WRF is actually suggesting a new closed circulation
will develop at the based of the mean trough over the upper
Midwest, somewhere near the OK/TX panhandles by Tuesday night,
moving into southern Missouri by Wednesday evening. This is similar to
what the ECMWF advertised in the Friday/Saturday model runs. This
will lead to enhanced precipitation, both pre/post frontal as the
frontal boundary remains fixed along the Interstate 57/55 corridor
in Southern IL/Southeast Missouri. Most of the upright
(thunderstorm) instability may be mixed out by Tuesday afternoon
and night, but warm top (satellite reference) convection processes
will likely take over increasing the effectiveness of the
rainfall from Tuesday into Wednesday. There is still some question
with respect to severe potential during this time period, but
heavy rainfall still remains the dominant threat Tuesday into
Wednesday.
.LONG TERM...(Wednesday through Sunday)
Issued at 417 PM CDT SUN MAY 11 2014
Confidence is fairly high concerning the general synoptic pattern in
the Wed-Sun time frame. It is looking more and more like a high
amplitude mid level trof will be carved out from southeast Canada
southward all the way into the Ms River Valley by the Wed/Thu
period. On east side of the trof, broad swly flow aloft will be
evident. As a sfc low lifts ne along the spine of the Appalachians
Wed, it appears showers will once again overspread most of the
forecast area. Highest rain amounts will probably be over wrn KY and
sw IN. Once the sfc low pulls off to the northeast Wed night, and
the h50 trof axis moves east of the region, rain chcs should
decrease considerably for much of the remainder of the extended.
However, very low height fields and extensive daytime cloudiness
behind the system will likely lead to an extended period of below
normal temperatures. Highs are only expected to reach the 60s most
locations Thu/Fri/Sat.
&&
.AVIATION...
Issued at 1258 PM CDT SUN MAY 11 2014
Expect generally VFR conditions through the TAF period. Hit and
miss thunderstorms will need to be monitored through the afternoon
for brief IFR restrictions, but coverage is just not high enough
to mention explicitly in the TAF package at this time.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...LAKE WIND ADVISORY until 7 PM CDT this evening FOR ILZ080-084-
088-092.
MO...LAKE WIND ADVISORY until 7 PM CDT this evening FOR MOZ076-086-
087-100-107>111-114.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...Smith
LONG TERM...GM
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1239 PM CDT Sun May 11 2014
.MESOSCALE DISCUSSION...
Issued at 1238 PM CDT SUN MAY 11 2014
This interim (midday) update was a little challenging given the
impact of the early morning showers and thunderstorms that
transited across the north part of the WFO CWA. The more organized
cluster of multicell storms set up a fairly robust outflow
boundary region this morning. Even with the expectation that this
complex would develop overnight and into this morning, the degree
of cold pool generation was more impressive than expected.
In addition, there is a slight veering of winds between 7-17kft
per the KPAH VAD Wind Profile to support a little enhanced shear
for updrafts. This may be enough to maintain isolated to widely
scattered clusters of multicell thunderstorms into the afternoon,
given cold pool interactions among developing cells and
established thunderstorms.
The 3km HRRR and 12km NAM-WRF have picked up on the interaction of
this cold pool and the attendant theta-e convergence south of the
boundary (per hourly LAPS instability fields). With this in mind,
a greater coverage of thunderstorms had to be considered for this
afternoon than previously forecast.
Associated adjustment to temperature, dewpoint, winds, and sky
cover were made to reflect the change in thunderstorm activity
this afternoon.
Depending on the coverage of shower and thunderstorm activity,
there is still some uncertainty as to the degree of severe
potential this afternoon and the potential interaction with the
IA/MO MCS. Will have to take a "wait and see" position on this matter.
The current Lake Wind Advisory still looks to be good call for
this afternoon.
&&
.SHORT TERM...(Today through Tuesday night)
Issued at 304 AM CDT SUN MAY 11 2014
Scattered thunderstorms moving eastward across the far northern
sections of our CWA at the time of this writing should continue to
shift eastward and weaken with time (by sunrise).
Beyond that there will probably be a lull in convective activity
this morning, but this afternoon isolated thunderstorms are possible
just about anywhere in the heat of the day. Coverage may become a
bit more widespread in the vicinity of any outflow boundaries laid
down by the overnight convection, but would be too difficult to pin
down, so consequently just went with a 15 POP everywhere and just
mentioned isolated thunderstorms.
As a storm system begins to move out of the plains tonight, it will
turn the flow aloft back to southwest thereby pumping the H5 ridge
up a bit over our area. Combined with no low level forcing and being
in the warm sector, expect it to be dry. Precipitation chances make
their way back into the forecast on Monday as the aforementioned
system moves ever closer to our area. Precipitation chances will be
highest Monday night and Tuesday as the system actually crosses the
area.
There is some disparity between models on how things are going to
evolve Tuesday night. All models show the approach of a sharp short
wave with southwest flow aloft parallel to the departing frontal
boundary, yet the GFS pushes the boundary through the area with
decreasing precipitation chances from west to east. The NAM12, SREF,
and GEM are all showing a wave being induced on the front as a
result of the approaching short wave thus producing an overrunning
scenario which produces decent precipitation chances back across the
entire CWA. Given the synoptic parameters, I tend to believe the
solution of the majority, so increased POPs accordingly.
.LONG TERM...(Wednesday through Saturday)
Issued at 304 AM CDT SUN MAY 11 2014
Rain shower chances will linger through much of the week as a deep
longwave trough slowly trudges east across the nation. Rain is not
expected all the time, but until the mean trough axis finally clears
the region, the chance for rain will be present each day.
Starting with 12Z Wednesday, the axis of the 500mb trough will be
positioned from low pressure over Ontario south across the Upper
Midwest into the Missouri Valley and Southern Plains. A cold front
will be positioned just east of the forecast area. Models are still
not in complete agreement on the synoptic setup during the mid to
late week, with the GFS still a notable outlier compared with the
ECMWF and GEM. We continue to favor the slower majority solution at
this time.
Consequently, Wednesday is looking rather soggy as a piece of
southern stream energy ejects northeast from the base of the upper
level trough. Will carry likely precipitation probabilities across
the entire region on Wednesday. Any elevated instability will be
limited to southwest Indiana and the Pennyrile region of western
Kentucky, so introduced a slight chance thunder mention there.
It appears as though the better rain chances will shift east of the
area by Wednesday night and Thursday. However, with the upper level
trough still positioned directly overhead, scattered rain showers
still cannot be ruled out, especially from late morning through
early evening each day. Even once the trough axis moves just to our
east, energy rotating around the back side of the trough makes the
return to dry weather less certain late in the week. Limited
instability should keep any thunder to a minimum during this time.
Much more certain is the drop in temperatures in the wake of the
Tuesday cold frontal passage. Highs through the remainder of the
week should only reach the 60s, with lows between 45 and 50.
&&
.AVIATION...
Issued at 304 AM CDT SUN MAY 11 2014
A complex of thunderstorms over the St Louis Metro area at this
time will most likely progress east or east southeast overnight,
and may clip KEVV on the way by. Also would not be surprised to
see a portion of the complex split off and propagate slowly
southward, potentially impacting KCGI or KPAH by morning. Will
monitor for possible inclusion of TS in the forecast, but
confidence at this time is too low to insert as prevailing or even
a TEMPO condition.
Some increase in lower clouds is expected toward morning, but they
should be at or above 3kft. Forecast sounding data indicate that
diurnal convection is a good possibility throughout the area
Sunday. Decided to mention TS in a PROB30 at all sites through the
afternoon. Otherwise some gusty south winds are likely from mid-
morning through the afternoon at all sites.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...LAKE WIND ADVISORY until 7 PM CDT this evening FOR ILZ080-084-
088-092.
MO...LAKE WIND ADVISORY until 7 PM CDT this evening FOR MOZ076-086-
087-100-107>111-114.
IN...NONE.
KY...NONE.
&&
$$
MESOSCALE...Smith
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1248 PM EDT Sun May 11 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1140 AM EDT Sun May 11 2014
A few storms are moving back into southern Indiana late this
morning. Taking a look at models this morning, most of them seem to
be overdoing convection for the morning hours, which makes this
afternoon`s forecast all the more difficult. The HRRR seems to have
the best handle on the current situation, though it is not great
either. Still think the best chance for storms will be west of I-65.
However, cannot rule out isolated storms across east central
Kentucky, so added low pops to this area for the afternoon. The rest
of the forecast remains unchanged.
Issued at 930 AM EDT Sun May 11 2014
The convection from the MCS across southern Indiana this morning
continues to move east. Went ahead and removed pops for the
remainder of the morning hours. A couple of outflow boundaries from
this convection have set up across southern Indiana and central
Kentucky. These may serve as a focus for some strong storms this
afternoon, particularly across southern Indiana which will be closer
to an upper level disturbance. Also removed the fog wording from the
forecast as fog that developed this morning has mixed out.
.SHORT TERM (Now through Monday)...
Issued at 325 AM EDT Sun May 11 2014
The synoptic pattern early this morning features a strong
upper-level trough diving into the southwestern CONUS. In response,
the upper-level flow has begun to amplify a ridge over the Ohio
Valley. This amplification will continue through the short-term
period, leading to much warmer temperatures.
An MCS continue to progress across portions of central Illinois and
western Indiana this morning. This activity is located along the
LLJ axis, which extends from Missouri northeast into IL and IN.
Current trends suggest this activity will remain mostly north of the
region, but could clip our southern IN counties in the pre-dawn
hours. Therefore, will raise pops a bit to account for this
activity.
Otherwise, the MCS will quickly dissipate this morning, leaving
partly to mostly cloudy skies in it`s wake. As thicknesses rise, we
should see temperatures climb well into the 80s today. There is a
consistent signal in both synoptic and hi-res guidance that some
isolated to widely scattered thunderstorms will develop this
afternoon into early this evening, mainly along and west of I-65.
Here, low-level moisture will increase which coupled with
temperatures in the 80s, will yield MLCAPE on the order of 1500-2500
J/kg. As opposed to yesterday, forcing looks rather benign, with no
significant surface future for convection to focus on (although an
outflow boundary from this morning`s MCS could set up across the
region so this will have to be monitored today for a possible
convective focus). As a wave of isentropic ascent spreads northeast
across the region, the lift may be enough to pop some convection
within an uncapped atmosphere. Given the degree of instability,
some isolated stronger storms with small hail and gusty winds will
be possible, but the lack of any significant, convergent surface
feature or upper-level support should help to limit storm
organization.
Any convection this evening will quickly dissipate with the loss of
daytime heating, leading to a dry night. Winds should stay up a bit
as high-level clouds stream by. Thus, think temperatures will stay
up a bit in the mid to upper 60s.
Monday looks quite similar to today. Instability will once again
build in the afternoon, but any forcing will be subtle and
incoherent. Therefore, will continue with just slight chance of
thunderstorms in the afternoon hours, but most will stay dry. Highs
may be a degree warmer than today as the upper-level ridge takes
hold, with highs in the middle to even upper 80s.
.LONG TERM (Monday Night through Saturday)...
Issued at 330 AM EDT Sun May 11 2014
The long term guidance continues to show an active pattern across
North America through the upcoming long term period as a significant
upper level trough axis moves through the Plains states and then
develops into a large upper level gyre over the Great Lakes by the
late part of the work week. A strong cold front associated with the
upper level wave is forecast to push through the region around
midweek bringing a good amount of precipitation to the region along
with a threat of thunderstorms. In the post frontal wake, it
appears that scattered to numerous diurnally driven rain showers
will continue into the latter half of the week along with colder
than normal temperatures. Current data still suggests that we`ll
see temperatures drop to 10 to perhaps as much as 20 degrees below
seasonal normals by late week and into next weekend.
Monday night through Wednesday Night...
Latest model guidance continues to show better forecast convergence
in this time frame with the frontal boundary coming through the
region. It appears that ridging will hold on for Monday night into
most of Tuesday. In fact, Tuesday could be a bit drier and warmer
as the front approaches from the west. Lows Monday night will be
mild with readings generally in the middle to upper 60s. Tuesday is
a bit of a question mark which will depend on clouds and
precipitation in the pre-frontal airmass. The Euro and Canadian GEM
guidance are very bullish on temperatures for Tuesday with highs
climbing into the middle to upper 80s. We are a bit hesitant to
jump on temperatures that quickly, but the multi-model consensus has
trended warmer, so we have raised temperatures into the middle 80s
for much of the region.
Scattered showers and storms will likely develop to our west along
the frontal boundary and push into the region Tuesday afternoon and
evening. The front will slow down a bit and stall slightly on
Wednesday across our region. A strong mid-level vorticity lobe will
advance through the upper trough and likely result in a secondary
area of low pressure which would ride up along the frontal
boundary. This feature would end up producing widespread clouds
and precipitation for the Wednesday and Wednesday night time frame.
For now, have kept much of the forecast trends intact here with the
high probabilities of precipitation from Tuesday evening through
Wednesday evening. Thunderstorms will accompany the front as it
pushes through Tuesday afternoon/evening. However, main dynamical
forcing will be well to the north of our region. Slab forced ascent
combined with abundant height falls aloft should result in adequate
lift for convection. Heavy rainfall, lightning, and gusty winds
appear to be the main threats at this time.
Temperatures Tuesday night will cool into the upper 50s to the lower
60s with highs on Wednesday warming into the mid-upper 60s in the
west and upper 60s to lower 70s in the east. Distinctly cooler
weather will arrive Wednesday night as temperatures fall into the
upper 40s behind the frontal boundary.
Thursday through Saturday...
Surface frontal boundary is expected to be to the east of the region
by Thursday morning with the upper trough axis lagging behind. The
upper trough axis looks to pass over the region Thursday afternoon
and evening which will likely produce scattered rain showers. The
rain chances will likely diminish in areal coverage by
Friday...except perhaps across our northeastern counties where
isolated showers may persist into the day on Friday. The
aforementioned frontal boundary looks to stall out across the deep
south by late Friday into Saturday with several disturbances moving
through the upper trough which will remain across the eastern US.
These disturbances may continue to produce cloudiness along with
isolated showers...especially during the afternoon hours. The
larger weather story of the period will the drop in temperatures
compared to what we have seen of late. The cool northwest flow will
keep temperatures some 10 to as much as 20 degrees below seasonal
normals. Highs Thursday through Saturday will only warm into the
lower 60s in the north with lower to middle 60s across the south.
Overnight lows will generally be in the lower to middle 40s.
Generally stuck close to the Euro bias-corrected temperature
profiles for the this time frame given their exceptional
verification over the last 5-7 days in this forecast time frame.
&&
.AVIATION (18Z TAF Update)...
Issued at 145 PM EDT Sun May 11 2014
A cu field is increasing across the area this afternoon as
instability increases. Some storms have developed across southern IN
and western KY and will spread eastward through the afternoon. The
best chance for thunderstorms this afternoon will be at SDF and BWG
from around 20-00Z. Will continue the mention of VCTS for these
terminals and monitor for amendments when storms do develop. There
is an isolated chance for storms to develop at LEX. However,
coverage is expected to be less across east central KY, so will
leave mention out of the TAF for now. Winds will be out of the south
and increase to around 10 knots this afternoon. For tonight some
light fog may be possible, mainly at BWG where winds look to be a
bit lighter.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........EER
Short Term.....KJD
Long Term......MJ
Aviation.......EER
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1142 AM EDT Sun May 11 2014
...Forecast Update...
Issued at 1140 AM EDT Sun May 11 2014
A few storms are moving back into southern Indiana late this
morning. Taking a look at models this morning, most of them seem to
be overdoing convection for the morning hours, which makes this
afternoon`s forecast all the more difficult. The HRRR seems to have
the best handle on the current situation, though it is not great
either. Still think the best chance for storms will be west of I-65.
However, cannot rule out isolated storms across east central
Kentucky, so added low pops to this area for the afternoon. The rest
of the forecast remains unchanged.
Issued at 930 AM EDT Sun May 11 2014
The convection from the MCS across southern Indiana this morning
continues to move east. Went ahead and removed pops for the
remainder of the morning hours. A couple of outflow boundaries from
this convection have set up across southern Indiana and central
Kentucky. These may serve as a focus for some strong storms this
afternoon, particularly across southern Indiana which will be closer
to an upper level disturbance. Also removed the fog wording from the
forecast as fog that developed this morning has mixed out.
.SHORT TERM (Now through Monday)...
Issued at 325 AM EDT Sun May 11 2014
The synoptic pattern early this morning features a strong
upper-level trough diving into the southwestern CONUS. In response,
the upper-level flow has begun to amplify a ridge over the Ohio
Valley. This amplification will continue through the short-term
period, leading to much warmer temperatures.
An MCS continue to progress across portions of central Illinois and
western Indiana this morning. This activity is located along the
LLJ axis, which extends from Missouri northeast into IL and IN.
Current trends suggest this activity will remain mostly north of the
region, but could clip our southern IN counties in the pre-dawn
hours. Therefore, will raise pops a bit to account for this
activity.
Otherwise, the MCS will quickly dissipate this morning, leaving
partly to mostly cloudy skies in it`s wake. As thicknesses rise, we
should see temperatures climb well into the 80s today. There is a
consistent signal in both synoptic and hi-res guidance that some
isolated to widely scattered thunderstorms will develop this
afternoon into early this evening, mainly along and west of I-65.
Here, low-level moisture will increase which coupled with
temperatures in the 80s, will yield MLCAPE on the order of 1500-2500
J/kg. As opposed to yesterday, forcing looks rather benign, with no
significant surface future for convection to focus on (although an
outflow boundary from this morning`s MCS could set up across the
region so this will have to be monitored today for a possible
convective focus). As a wave of isentropic ascent spreads northeast
across the region, the lift may be enough to pop some convection
within an uncapped atmosphere. Given the degree of instability,
some isolated stronger storms with small hail and gusty winds will
be possible, but the lack of any significant, convergent surface
feature or upper-level support should help to limit storm
organization.
Any convection this evening will quickly dissipate with the loss of
daytime heating, leading to a dry night. Winds should stay up a bit
as high-level clouds stream by. Thus, think temperatures will stay
up a bit in the mid to upper 60s.
Monday looks quite similar to today. Instability will once again
build in the afternoon, but any forcing will be subtle and
incoherent. Therefore, will continue with just slight chance of
thunderstorms in the afternoon hours, but most will stay dry. Highs
may be a degree warmer than today as the upper-level ridge takes
hold, with highs in the middle to even upper 80s.
.LONG TERM (Monday Night through Saturday)...
Issued at 330 AM EDT Sun May 11 2014
The long term guidance continues to show an active pattern across
North America through the upcoming long term period as a significant
upper level trough axis moves through the Plains states and then
develops into a large upper level gyre over the Great Lakes by the
late part of the work week. A strong cold front associated with the
upper level wave is forecast to push through the region around
midweek bringing a good amount of precipitation to the region along
with a threat of thunderstorms. In the post frontal wake, it
appears that scattered to numerous diurnally driven rain showers
will continue into the latter half of the week along with colder
than normal temperatures. Current data still suggests that we`ll
see temperatures drop to 10 to perhaps as much as 20 degrees below
seasonal normals by late week and into next weekend.
Monday night through Wednesday Night...
Latest model guidance continues to show better forecast convergence
in this time frame with the frontal boundary coming through the
region. It appears that ridging will hold on for Monday night into
most of Tuesday. In fact, Tuesday could be a bit drier and warmer
as the front approaches from the west. Lows Monday night will be
mild with readings generally in the middle to upper 60s. Tuesday is
a bit of a question mark which will depend on clouds and
precipitation in the pre-frontal airmass. The Euro and Canadian GEM
guidance are very bullish on temperatures for Tuesday with highs
climbing into the middle to upper 80s. We are a bit hesitant to
jump on temperatures that quickly, but the multi-model consensus has
trended warmer, so we have raised temperatures into the middle 80s
for much of the region.
Scattered showers and storms will likely develop to our west along
the frontal boundary and push into the region Tuesday afternoon and
evening. The front will slow down a bit and stall slightly on
Wednesday across our region. A strong mid-level vorticity lobe will
advance through the upper trough and likely result in a secondary
area of low pressure which would ride up along the frontal
boundary. This feature would end up producing widespread clouds
and precipitation for the Wednesday and Wednesday night time frame.
For now, have kept much of the forecast trends intact here with the
high probabilities of precipitation from Tuesday evening through
Wednesday evening. Thunderstorms will accompany the front as it
pushes through Tuesday afternoon/evening. However, main dynamical
forcing will be well to the north of our region. Slab forced ascent
combined with abundant height falls aloft should result in adequate
lift for convection. Heavy rainfall, lightning, and gusty winds
appear to be the main threats at this time.
Temperatures Tuesday night will cool into the upper 50s to the lower
60s with highs on Wednesday warming into the mid-upper 60s in the
west and upper 60s to lower 70s in the east. Distinctly cooler
weather will arrive Wednesday night as temperatures fall into the
upper 40s behind the frontal boundary.
Thursday through Saturday...
Surface frontal boundary is expected to be to the east of the region
by Thursday morning with the upper trough axis lagging behind. The
upper trough axis looks to pass over the region Thursday afternoon
and evening which will likely produce scattered rain showers. The
rain chances will likely diminish in areal coverage by
Friday...except perhaps across our northeastern counties where
isolated showers may persist into the day on Friday. The
aforementioned frontal boundary looks to stall out across the deep
south by late Friday into Saturday with several disturbances moving
through the upper trough which will remain across the eastern US.
These disturbances may continue to produce cloudiness along with
isolated showers...especially during the afternoon hours. The
larger weather story of the period will the drop in temperatures
compared to what we have seen of late. The cool northwest flow will
keep temperatures some 10 to as much as 20 degrees below seasonal
normals. Highs Thursday through Saturday will only warm into the
lower 60s in the north with lower to middle 60s across the south.
Overnight lows will generally be in the lower to middle 40s.
Generally stuck close to the Euro bias-corrected temperature
profiles for the this time frame given their exceptional
verification over the last 5-7 days in this forecast time frame.
&&
.AVIATION (12Z TAF Update)...
Issued at 642 AM EDT Sun May 11 2014
An MCS continues to push north of all sites this morning. The cloud
cover associated with this convection has helped to keep any dense
fog rather patchy, with light fog being the general rule. After a
couple more hours of MVFR vsbys at KSDF and IFR at KLEX/KBWG,
conditions will quickly go VFR later this morning.
Guidance has come into a bit better agreement on convection for this
afternoon. Therefore, have gone ahead and added VCTS into KSDF and
KBWG, as timing and coverage have become a bit more clear.
Otherwise, outside of any thunderstorms, expect VFR conditions
through the day with southerly winds around 8-13 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........EER
Short Term.....KJD
Long Term......MJ
Aviation.......KJD
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1203 PM CDT SUN MAY 11 2014
.AVIATION...
GENERAL VFR CONDITIONS ARE EXPECTED OUTSIDE CONVECTIVE IMPACTS.
AREA UNDER A VERY UNSTABLE AIR MASS WHERE COVERAGE MAY BECOME
ROBUST FOR AN HOUR OR TWO BETWEEN 18Z-22Z BEFORE THINNING OUT.
CONVECTIVE GUST POTENTIAL APPEARS TO BE IN THE 30-35 KT RANGE FROM
DOWN BURSTS BUT ALL ACTIVITY IS IMPLANTED ON DEEP LAYERED
SOUTHEASTERLY FLOW FOR CELL MOVEMENTS 15-20 KT TO THE NNW. SOME
MVFR CIGS/VSBY POSSIBLE OVERNIGHT FROM RESIDUAL MOISTURE AFTER
BOUNDARY LAYER DECOUPLES...THEN IMPROVING TO VFR BASES 030-040
MAINLY AFTER 15Z MONDAY. 24/RR
&&
.PREV DISCUSSION... /ISSUED 927 AM CDT SUN MAY 11 2014/
SOUNDING DISCUSSION...
12Z SOUNDING WAS NOT QUITE AS MOIST AS PREVIOUS WITH THE PRECIP
WATER AT 1.57 INCHES...DOWN FROM 1.85 INCHES. INSTABILITY HAD
INCREASED HOWEVER WITH THE MUCAPE AT 2321 J/KG AND LI -5. ELEVATED
CAP/INVERSION WAS AROUND 550 MB...BUT THIS WILL BE TOO HIGH UP TO
BE AN INHIBITOR FOR DEEP CONVECTION TODAY ONCE TEMPERATURES REACH
THE LOWER 80S. WIND PROFILE FROM SURFACE TO 700 MB WAS SOUTHERLY
15 TO 25 KNOTS WHICH WILL BE FAVORABLE FOR TRANSPORTING DEEPER LOW
LEVEL MOISTURE AND HIGHER PRECIP WATER VALUES BACK INTO THE
FORECAST AREA BY EARLY AFTERNOON AS INDICATED BY THE MODELS. THIS
LOOKS SUPPORTIVE OF THE CURRENT FORECAST PROBABILITY OF 40 PERCENT
FOR SHOWERS AND THUNDERSTORMS. ABOVE 700 MB...WINDS BECOME LIGHT
AND VARIABLE FROM 650 MB TO AROUND 400 MB...AND THIS KNOCKS THE
0-6 KM STORM MOTION DOWN TO 195 DEGREES AT 9 KNOTS. WESTERLY WINDS
INCREASE QUITE A BIT ABOVE 300 MB PEAKING NEAR 85 KNOTS NEAR 150
MB/ 45 KFT. 22/TD
PREV DISCUSSION... /ISSUED 355 AM CDT SUN MAY 11 2014/
DISCUSSION...
GENERALLY ONLY MINOR CHANGES MADE TO THE FORECAST WITH THIS
PACKAGE AS FORECAST REASONING HASN/T CHANGED AND MODELS ARE
COMING INTO BETTER AGREEMENT CONCERNING THE MID WEEK COLD FRONT.
MUGGY CONDITIONS WILL STICK AROUND THROUGH MID WEEK AS ONSHORE
WINDS CONTINUE TO RESULT IN AN INFLUX OF WARM AND MOIST AIR INTO
THE REGION FROM THE GULF OF MEXICO. THIS WILL KEEP TEMPERATURES...
ESPECIALLY OVERNIGHT...ABOVE NORMAL. AFTERNOON TEMPERATURES
GENERALLY FORECAST TO TOP OUT IN THE MID TO UPPER 80S WITH
OVERNIGHT LOWS STRUGGLING TO DROP BELOW 70 DEGREES.
EXPECT DIURNALLY FORCED CONVECTION EACH AFTERNOON WITH GENERALLY
ISOLATED TO WIDELY SCATTERED COVERAGE. LATEST MODEL RUNS...BOTH
SYNOPTIC AND MESOSCALE...ARE A BIT MORE AGGRESSIVE DEVELOPING
CONVECTION TODAY SO HAVE BUMPED POPS UP TO SOLID CHANCE...AROUND
40 PERCENT...FOR MOST OF THE AREA. LATEST HRRR AND NCEP WRF RUNS
INDICATE SOME CONVECTION DEVELOPING OVER THE NORTHERN GULF BY 14Z
OR 15Z AND THEN MOVING OR SPREADING INLAND BY EARLY AFTERNOON. ON
AVERAGE...QPF SHOULD BE LESS THAN A QUARTER INCH...BUT A FEW
PLACES COULD SEE UP TO AN INCH OF RAIN TODAY IF IMPACTED BY A
HEAVIER STORM OR TWO. SIMILAR CONDITIONS EXPECTED MONDAY...
THOUGH COVERAGE SHOULD BE SLIGHTLY LESS. AM CARRYING 20 TO 30
PERCENT POPS ACROSS THE AREA MONDAY AFTERNOON.
BY TUESDAY...STRONG UPPER TROUGH WILL BE DIGGING INTO THE PLAINS
STATES AND FORCING A COLD FRONT TOWARD THE NORTHERN GULF COAST
REGION. MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
BOTH THE AMPLITUDE OF THIS TROUGH AND THE TIMING OF THE SURFACE
COLD FRONT. LOOKS LIKE THE SURFACE FRONT SHOULD PASS THROUGH THE
AREA SOME TIME LATE TUESDAY NIGHT OR EARLY WEDNESDAY MORNING...
WITH COOLER AND DRIER AIR FILTERING INTO THE AREA DURING THE DAY
WEDNESDAY. EXPECT A FAIRLY SIGNIFICANT TEMPERATURE DROP BEHIND THE
FRONT WITH AFTERNOON HIGHS ON WEDNESDAY CURRENTLY FORECAST TO BE
5 TO 10 DEGREES LOWER THAN HIGHS ON TUESDAY. THE REAL DIFFERENCE
WILL BE FELT AT NIGHT...THOUGH...WITH OVERNIGHT LOWS PLUNGING INTO
THE 50S WEDNESDAY NIGHT THROUGH FRIDAY NIGHT FOR MOST OF THE AREA.
NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH THE REMAINDER OF THE
FORECAST PERIOD. MODELS CURRENTLY HINTING AT ANOTHER DISTURBANCE
MOVING INTO THE SOUTHEAST CONUS OVER THE WEEKEND...THOUGH BOTH THE
EURO AND GFS KEEP THE MOISTURE AND FORCING TO THE NORTHEAST OF THE
LOCAL AREA. WITH THIS IN MIND...AM KEEPING A DRY FORECAST THROUGH
THE WEEKEND AT THIS TIME.
AVIATION...
VARIABLE CONDITIONS WERE BEING OBSERVED EARLY THIS MORNING ACROSS
THE FORECAST AREA...RANGING FROM VFR TO LIFR DUE TO CEILINGS BEING
OBSERVED AT SOME OF THE TAF SITES. SOME GENERALLY LIGHT FOG WAS ALSO
IMPACTING A NUMBER OF THE TERMINALS. CONDITIONS ARE EXPECTED TO
IMPROVE TO VFR AT ALL LOCATIONS BY LATE MORNING OR EARLY AFTERNOON.
SCATTERED CONVECTION THIS AFTERNOON WILL BE POSSIBLE AT EACH OF THE
SITES. MVFR TO IFR CEILINGS WILL AGAIN BE POSSIBLE LATE TONIGHT AND
EARLY MONDAY MORNING.
MARINE...
MODERATE SOUTHEAST FLOW WILL CONTINUE ACROSS THE COASTAL WATERS
TODAY AND MONDAY BEFORE EASING ON TUESDAY. A COLD FRONT WILL PUSH
ACROSS THE COASTAL WATERS LATE TUESDAY NIGHT INTO WEDNESDAY WITH
STRONG OFFSHORE FLOW DEVELOPING IN ITS WAKE FROM LATE WEDNESDAY INTO
THURSDAY.
DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
MONITORING RIVER FLOODING
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 85 67 86 67 / 40 20 30 20
BTR 86 72 87 70 / 40 20 30 20
ASD 83 71 83 70 / 40 30 20 20
MSY 85 73 83 71 / 40 20 20 20
GPT 84 74 84 72 / 40 20 20 20
PQL 83 69 85 70 / 40 20 20 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
927 AM CDT SUN MAY 11 2014
.SOUNDING DISCUSSION...
12Z SOUNDING WAS NOT QUITE AS MOIST AS PREVIOUS WITH THE PRECIP
WATER AT 1.57 INCHES...DOWN FROM 1.85 INCHES. INSTABILITY HAD
INCREASED HOWEVER WITH THE MUCAPE AT 2321 J/KG AND LI -5. ELEVATED
CAP/INVERSION WAS AROUND 550 MB...BUT THIS WILL BE TOO HIGH UP TO
BE AN INHIBITOR FOR DEEP CONVECTION TODAY ONCE TEMPERATURES REACH
THE LOWER 80S. WIND PROFILE FROM SURFACE TO 700 MB WAS SOUTHERLY
15 TO 25 KNOTS WHICH WILL BE FAVORABLE FOR TRANSPORTING DEEPER LOW
LEVEL MOISTURE AND HIGHER PRECIP WATER VALUES BACK INTO THE
FORECAST AREA BY EARLY AFTERNOON AS INDICATED BY THE MODELS. THIS
LOOKS SUPPORTIVE OF THE CURRENT FORECAST PROBABILITY OF 40 PERCENT
FOR SHOWERS AND THUNDERSTORMS. ABOVE 700 MB...WINDS BECOME LIGHT
AND VARIABLE FROM 650 MB TO AROUND 400 MB...AND THIS KNOCKS THE
0-6 KM STORM MOTION DOWN TO 195 DEGREES AT 9 KNOTS. WESTERLY WINDS
INCREASE QUITE A BIT ABOVE 300 MB PEAKING NEAR 85 KNOTS NEAR 150
MB/ 45 KFT. 22/TD
&&
.PREV DISCUSSION... /ISSUED 355 AM CDT SUN MAY 11 2014/
DISCUSSION...
GENERALLY ONLY MINOR CHANGES MADE TO THE FORECAST WITH THIS
PACKAGE AS FORECAST REASONING HASN/T CHANGED AND MODELS ARE
COMING INTO BETTER AGREEMENT CONCERNING THE MID WEEK COLD FRONT.
MUGGY CONDITIONS WILL STICK AROUND THROUGH MID WEEK AS ONSHORE
WINDS CONTINUE TO RESULT IN AN INFLUX OF WARM AND MOIST AIR INTO
THE REGION FROM THE GULF OF MEXICO. THIS WILL KEEP TEMPERATURES...
ESPECIALLY OVERNIGHT...ABOVE NORMAL. AFTERNOON TEMPERATURES
GENERALLY FORECAST TO TOP OUT IN THE MID TO UPPER 80S WITH
OVERNIGHT LOWS STRUGGLING TO DROP BELOW 70 DEGREES.
EXPECT DIURNALLY FORCED CONVECTION EACH AFTERNOON WITH GENERALLY
ISOLATED TO WIDELY SCATTERED COVERAGE. LATEST MODEL RUNS...BOTH
SYNOPTIC AND MESOSCALE...ARE A BIT MORE AGGRESSIVE DEVELOPING
CONVECTION TODAY SO HAVE BUMPED POPS UP TO SOLID CHANCE...AROUND
40 PERCENT...FOR MOST OF THE AREA. LATEST HRRR AND NCEP WRF RUNS
INDICATE SOME CONVECTION DEVELOPING OVER THE NORTHERN GULF BY 14Z
OR 15Z AND THEN MOVING OR SPREADING INLAND BY EARLY AFTERNOON. ON
AVERAGE...QPF SHOULD BE LESS THAN A QUARTER INCH...BUT A FEW
PLACES COULD SEE UP TO AN INCH OF RAIN TODAY IF IMPACTED BY A
HEAVIER STORM OR TWO. SIMILAR CONDITIONS EXPECTED MONDAY...
THOUGH COVERAGE SHOULD BE SLIGHTLY LESS. AM CARRYING 20 TO 30
PERCENT POPS ACROSS THE AREA MONDAY AFTERNOON.
BY TUESDAY...STRONG UPPER TROUGH WILL BE DIGGING INTO THE PLAINS
STATES AND FORCING A COLD FRONT TOWARD THE NORTHERN GULF COAST
REGION. MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
BOTH THE AMPLITUDE OF THIS TROUGH AND THE TIMING OF THE SURFACE
COLD FRONT. LOOKS LIKE THE SURFACE FRONT SHOULD PASS THROUGH THE
AREA SOME TIME LATE TUESDAY NIGHT OR EARLY WEDNESDAY MORNING...
WITH COOLER AND DRIER AIR FILTERING INTO THE AREA DURING THE DAY
WEDNESDAY. EXPECT A FAIRLY SIGNIFICANT TEMPERATURE DROP BEHIND THE
FRONT WITH AFTERNOON HIGHS ON WEDNESDAY CURRENTLY FORECAST TO BE
5 TO 10 DEGREES LOWER THAN HIGHS ON TUESDAY. THE REAL DIFFERENCE
WILL BE FELT AT NIGHT...THOUGH...WITH OVERNIGHT LOWS PLUNGING INTO
THE 50S WEDNESDAY NIGHT THROUGH FRIDAY NIGHT FOR MOST OF THE AREA.
NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH THE REMAINDER OF THE
FORECAST PERIOD. MODELS CURRENTLY HINTING AT ANOTHER DISTURBANCE
MOVING INTO THE SOUTHEAST CONUS OVER THE WEEKEND...THOUGH BOTH THE
EURO AND GFS KEEP THE MOISTURE AND FORCING TO THE NORTHEAST OF THE
LOCAL AREA. WITH THIS IN MIND...AM KEEPING A DRY FORECAST THROUGH
THE WEEKEND AT THIS TIME.
AVIATION...
VARIABLE CONDITIONS WERE BEING OBSERVED EARLY THIS MORNING ACROSS
THE FORECAST AREA...RANGING FROM VFR TO LIFR DUE TO CEILINGS BEING
OBSERVED AT SOME OF THE TAF SITES. SOME GENERALLY LIGHT FOG WAS ALSO
IMPACTING A NUMBER OF THE TERMINALS. CONDITIONS ARE EXPECTED TO
IMPROVE TO VFR AT ALL LOCATIONS BY LATE MORNING OR EARLY AFTERNOON.
SCATTERED CONVECTION THIS AFTERNOON WILL BE POSSIBLE AT EACH OF THE
SITES. MVFR TO IFR CEILINGS WILL AGAIN BE POSSIBLE LATE TONIGHT AND
EARLY MONDAY MORNING.
MARINE...
MODERATE SOUTHEAST FLOW WILL CONTINUE ACROSS THE COASTAL WATERS
TODAY AND MONDAY BEFORE EASING ON TUESDAY. A COLD FRONT WILL PUSH
ACROSS THE COASTAL WATERS LATE TUESDAY NIGHT INTO WEDNESDAY WITH
STRONG OFFSHORE FLOW DEVELOPING IN ITS WAKE FROM LATE WEDNESDAY INTO
THURSDAY.
DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
MONITORING RIVER FLOODING
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 85 67 86 67 / 40 20 30 20
BTR 86 72 87 70 / 40 20 30 20
ASD 83 71 83 70 / 40 30 20 20
MSY 85 73 83 71 / 40 20 20 20
GPT 84 74 84 72 / 40 20 20 20
PQL 83 69 85 70 / 40 20 20 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW ORLEANS LA
355 AM CDT SUN MAY 11 2014
.DISCUSSION...
GENERALLY ONLY MINOR CHANGES MADE TO THE FORECAST WITH THIS
PACKAGE AS FORECAST REASONING HASN/T CHANGED AND MODELS ARE
COMING INTO BETTER AGREEMENT CONCERNING THE MID WEEK COLD FRONT.
MUGGY CONDITIONS WILL STICK AROUND THROUGH MID WEEK AS ONSHORE
WINDS CONTINUE TO RESULT IN AN INFLUX OF WARM AND MOIST AIR INTO
THE REGION FROM THE GULF OF MEXICO. THIS WILL KEEP TEMPERATURES...
ESPECIALLY OVERNIGHT...ABOVE NORMAL. AFTERNOON TEMPERATURES
GENERALLY FORECAST TO TOP OUT IN THE MID TO UPPER 80S WITH
OVERNIGHT LOWS STRUGGLING TO DROP BELOW 70 DEGREES.
EXPECT DIURNALLY FORCED CONVECTION EACH AFTERNOON WITH GENERALLY
ISOLATED TO WIDELY SCATTERED COVERAGE. LATEST MODEL RUNS...BOTH
SYNOPTIC AND MESOSCALE...ARE A BIT MORE AGGRESSIVE DEVELOPING
CONVECTION TODAY SO HAVE BUMPED POPS UP TO SOLID CHANCE...AROUND
40 PERCENT...FOR MOST OF THE AREA. LATEST HRRR AND NCEP WRF RUNS
INDICATE SOME CONVECTION DEVELOPING OVER THE NORTHERN GULF BY 14Z
OR 15Z AND THEN MOVING OR SPREADING INLAND BY EARLY AFTERNOON. ON
AVERAGE...QPF SHOULD BE LESS THAN A QUARTER INCH...BUT A FEW
PLACES COULD SEE UP TO AN INCH OF RAIN TODAY IF IMPACTED BY A
HEAVIER STORM OR TWO. SIMILAR CONDITIONS EXPECTED MONDAY...
THOUGH COVERAGE SHOULD BE SLIGHTLY LESS. AM CARRYING 20 TO 30
PERCENT POPS ACROSS THE AREA MONDAY AFTERNOON.
BY TUESDAY...STRONG UPPER TROUGH WILL BE DIGGING INTO THE PLAINS
STATES AND FORCING A COLD FRONT TOWARD THE NORTHERN GULF COAST
REGION. MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
BOTH THE AMPLITUDE OF THIS TROUGH AND THE TIMING OF THE SURFACE
COLD FRONT. LOOKS LIKE THE SURFACE FRONT SHOULD PASS THROUGH THE
AREA SOME TIME LATE TUESDAY NIGHT OR EARLY WEDNESDAY MORNING...
WITH COOLER AND DRIER AIR FILTERING INTO THE AREA DURING THE DAY
WEDNESDAY. EXPECT A FAIRLY SIGNIFICANT TEMPERATURE DROP BEHIND THE
FRONT WITH AFTERNOON HIGHS ON WEDNESDAY CURRENTLY FORECAST TO BE
5 TO 10 DEGREES LOWER THAN HIGHS ON TUESDAY. THE REAL DIFFERENCE
WILL BE FELT AT NIGHT...THOUGH...WITH OVERNIGHT LOWS PLUNGING INTO
THE 50S WEDNESDAY NIGHT THROUGH FRIDAY NIGHT FOR MOST OF THE AREA.
NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH THE REMAINDER OF THE
FORECAST PERIOD. MODELS CURRENTLY HINTING AT ANOTHER DISTURBANCE
MOVING INTO THE SOUTHEAST CONUS OVER THE WEEKEND...THOUGH BOTH THE
EURO AND GFS KEEP THE MOISTURE AND FORCING TO THE NORTHEAST OF THE
LOCAL AREA. WITH THIS IN MIND...AM KEEPING A DRY FORECAST THROUGH
THE WEEKEND AT THIS TIME.
&&
.AVIATION...
VARIABLE CONDITIONS WERE BEING OBSERVED EARLY THIS MORNING ACROSS
THE FORECAST AREA...RANGING FROM VFR TO LIFR DUE TO CEILINGS BEING
OBSERVED AT SOME OF THE TAF SITES. SOME GENERALLY LIGHT FOG WAS ALSO
IMPACTING A NUMBER OF THE TERMINALS. CONDITIONS ARE EXPECTED TO
IMPROVE TO VFR AT ALL LOCATIONS BY LATE MORNING OR EARLY AFTERNOON.
SCATTERED CONVECTION THIS AFTERNOON WILL BE POSSIBLE AT EACH OF THE
SITES. MVFR TO IFR CEILINGS WILL AGAIN BE POSSIBLE LATE TONIGHT AND
EARLY MONDAY MORNING.
&&
.MARINE...
MODERATE SOUTHEAST FLOW WILL CONTINUE ACROSS THE COASTAL WATERS
TODAY AND MONDAY BEFORE EASING ON TUESDAY. A COLD FRONT WILL PUSH
ACROSS THE COASTAL WATERS LATE TUESDAY NIGHT INTO WEDNESDAY WITH
STRONG OFFSHORE FLOW DEVELOPING IN ITS WAKE FROM LATE WEDNESDAY INTO
THURSDAY.
&&
.DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
MONITORING RIVER FLOODING
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 85 67 86 67 / 40 20 30 20
BTR 86 72 87 70 / 40 20 30 20
ASD 83 71 83 70 / 40 30 20 20
MSY 85 73 83 71 / 40 20 20 20
GPT 84 74 84 72 / 40 20 20 20
PQL 83 69 85 70 / 40 20 20 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AVIATION/MARINE...11
REST OF DISCUSSION...95/DM
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
331 AM CDT SUN MAY 11 2014
.DISCUSSION...
GENERALLY ONLY MINOR CHANGES MADE TO THE FORECAST WITH THIS
PACKAGE AS FORECAST REASONING HASN/T CHANGED AND MODELS ARE
COMING INTO BETTER AGREEMENT CONCERNING THE MID WEEK COLD FRONT.
MUGGY CONDITIONS WILL STICK AROUND THROUGH MID WEEK AS ONSHORE
WINDS CONTINUE TO RESULT IN AN INFLUX OF WARM AND MOIST AIR INTO
THE REGION FROM THE GULF OF MEXICO. THIS WILL KEEP TEMPERATURES...
ESPECIALLY OVERNIGHT...ABOVE NORMAL. AFTERNOON TEMPERATURES
GENERALLY FORECAST TO TOP OUT IN THE MID TO UPPER 80S WITH
OVERNIGHT LOWS STRUGGLING TO DROP BELOW 70 DEGREES.
EXPECT DIURNALLY FORCED CONVECTION EACH AFTERNOON WITH GENERALLY
ISOLATED TO WIDELY SCATTERED COVERAGE. LATEST MODEL RUNS...BOTH
SYNOPTIC AND MESOSCALE...ARE A BIT MORE AGGRESSIVE DEVELOPING
CONVECTION TODAY SO HAVE BUMPED POPS UP TO SOLID CHANCE...AROUND
40 PERCENT...FOR MOST OF THE AREA. LATEST HRRR AND NCEP WRF RUNS
INDICATE SOME CONVECTION DEVELOPING OVER THE NORTHERN GULF BY 14Z
OR 15Z AND THEN MOVING OR SPREADING INLAND BY EARLY AFTERNOON. ON
AVERAGE...QPF SHOULD BE LESS THAN A QUARTER INCH...BUT A FEW
PLACES COULD SEE UP TO AN INCH OF RAIN TODAY IF IMPACTED BY A
HEAVIER STORM OR TWO. SIMILAR CONDITIONS EXPECTED MONDAY...
THOUGH COVERAGE SHOULD BE SLIGHTLY LESS. AM CARRYING 20 TO 30
PERCENT POPS ACROSS THE AREA MONDAY AFTERNOON.
BY TUESDAY...STRONG UPPER TROUGH WILL BE DIGGING INTO THE PLAINS
STATES AND FORCING A COLD FRONT TOWARD THE NORTHERN GULF COAST
REGION. MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING
BOTH THE AMPLITUDE OF THIS TROUGH AND THE TIMING OF THE SURFACE
COLD FRONT. LOOKS LIKE THE SURFACE FRONT SHOULD PASS THROUGH THE
AREA SOME TIME LATE TUESDAY NIGHT OR EARLY WEDNESDAY MORNING...
WITH COOLER AND DRIER AIR FILTERING INTO THE AREA DURING THE DAY
WEDNESDAY. EXPECT A FAIRLY SIGNIFICANT TEMPERATURE DROP BEHIND THE
FRONT WITH AFTERNOON HIGHS ON WEDNESDAY CURRENTLY FORECAST TO BE
5 TO 10 DEGREES LOWER THAN HIGHS ON TUESDAY. THE REAL DIFFERENCE
WILL BE FELT AT NIGHT...THOUGH...WITH OVERNIGHT LOWS PLUNGING INTO
THE WEDNESDAY NIGHT THROUGH FRIDAY NIGHT FOR MOST OF THE AREA.
NORTHWEST FLOW ALOFT WILL PREVAIL THROUGH THE REMAINDER OF THE
FORECAST PERIOD. MODELS CURRENTLY HINTING AT ANOTHER DISTURBANCE
MOVING INTO THE SOUTHEAST CONUS OVER THE WEEKEND...THOUGH BOTH THE
EURO AND GFS KEEP THE MOISTURE AND FORCING TO THE NORTHEAST OF THE
LOCAL AREA. WITH THIS IN MIND...AM KEEPING A DRY FORECAST THROUGH
THE WEEKEND AT THIS TIME.
&&
.AVIATION...
VARIABLE CONDITIONS WERE BEING OBSERVED EARLY THIS MORNING ACROSS
THE FORECAST AREA...RANGING FROM VFR TO LIFR DUE TO CEILINGS BEING
OBSERVED AT SOME OF THE TAF SITES. SOME GENERALLY LIGHT FOG WAS ALSO
IMPACTING A NUMBER OF THE TERMINALS. CONDITIONS ARE EXPECTED TO
IMPROVE TO VFR AT ALL LOCATIONS BY LATE MORNING OR EARLY AFTERNOON.
SCATTERED CONVECTION THIS AFTERNOON WILL BE POSSIBLE AT EACH OF THE
SITES. MVFR TO IFR CEILINGS WILL AGAIN BE POSSIBLE LATE TONIGHT AND
EARLY MONDAY MORNING.
&&
.MARINE...
MODERATE SOUTHEAST FLOW WILL CONTINUE ACROSS THE COASTAL WATERS
TODAY AND MONDAY BEFORE EASING ON TUESDAY. A COLD FRONT WILL PUSH
ACROSS THE COASTAL WATERS LATE TUESDAY NIGHT INTO WEDNESDAY WITH
STRONG OFFSHORE FLOW DEVELOPING IN ITS WAKE FROM LATE WEDNESDAY INTO
THURSDAY.
&&
.DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
MONITORING RIVER FLOODING
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 85 67 86 67 / 40 20 30 20
BTR 86 72 87 70 / 40 20 30 20
ASD 83 71 83 70 / 40 30 20 20
MSY 85 73 83 71 / 40 20 20 20
GPT 84 74 84 72 / 40 20 20 20
PQL 83 69 85 70 / 40 20 20 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AVIATION/MARINE...11
REST OF DISCUSSION...95/DM
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
643 PM EDT SUN MAY 11 2014
.SYNOPSIS...
ALTHOUGH WARM WEATHER WILL QUICKLY RETURN...THE CHANCE FOR RAIN
INCREASES AS THE WEEK PROGRESSES.
&&
.NEAR TERM /THROUGH MONDAY/...
ONLY MADE A SLIGHT UPDATE TO ADJUST POPS THROUGH THE NEXT SEVERAL
HOURS BASED ON RECENT SATELLITE DATA AND RADAR TRENDS AS SOME
SHOWERS HAVE POPPED UP IN OHIO. THE HI RES MODELS CONTINUE TO
INDICATE THAT FURTHER DEVELOPMENT COULD OCCUR IN OHIO
TONIGHT...WITH THE HRRR BRINGING A SECOND WAVE OVER THE NORTHERN
COUNTIES TOWARDS MORNING. AS OF NOW HOWEVER...THE MESOANALYSIS
SHOWS THAT MUCH OF THE REGION REMAINS CAPPED. WILL MAINTAIN CHANCE
POPS THROUGH THE OVERNIGHT WITH ADVANCING WARM FRONT.
OTHERWISE FORECAST REMAINS ON TRACK.
PREVIOUS DISCUSSION FOLLOWS...
PRECIP CHANCES WILL CONTINUE THROUGH THE DAY ON
MONDAY...INCREASING DURING THE AFTERNOON AS INSTABILITY INCREASES
WITH DAYTIME HEATING. MOISTURE ADVECTION WILL INCREASE IN THE
RESULTING SOUTH/SOUTHWEST FLOW PUSHING PWAT VALUES BACK UP TO JUST
BELOW 1.5" WHICH IS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL
FOR THIS TIME OF YEAR. THERE IS A LARGE DIFFERENCE IN MODEL
FORECAST CAPE VALUES FOR MONDAY AFTERNOON RANGING FROM 500 TO 1500
J/KG...BUT IN ANY CASE WITH RELATIVELY WEAK SHEAR AND STORM MOTION
AROUND 15KTS...THE POTENTIAL FOR SEVERE WEATHER LOOKS LOW ATTM.
THE WARMING TREND IN TEMPERATURES WILL REMAIN INTACT AS RIDGING
CONTINUES TO BUILD ACROSS THE EASTERN CONUS THROUGH MONDAY AND LOW
PRESSURE DEEPENS OVER THE INTERMOUNTAIN WEST...WITH MAX
TEMPERATURES FORECAST TO BE APPROXIMATELY 15 DEGREES ABOVE NORMAL
ON MONDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
WITH THE WESTERN TOUGH SLOWLY TRANSITIONING EAST...NOT MUCH CHANGE
IS IN STORE FOR TUESDAY WITH MAX TEMPERATURES NOSING UP FURTHER
AND SHOWER/THUNDERSTORM CHANCES AGAIN MAINLY DURING THE AFTERNOON
AND EARLY EVENING. BY WEDNESDAY THE LONGWAVE TROUGH WILL HAVE
MOVED FAR ENOUGH EAST TO INCREASE DYNAMICS ACROSS THE FORECAST
AREA AND WITH PLENTY OF MOISTURE AND INSTABILITY ALREADY IN PLACE
IT LOOKS LIKELY THAT THERE WILL BE MORE WIDESPREAD THUNDERSTORM
COVERAGE. INCREASED DIRECTIONAL AND SPEED SHEAR ALOFT ALSO RAISES
THE POTENTIAL FOR MORE ORGANIZED CONVECTION BY WEDNESDAY...BUT
ATTM VALUES ARE STILL MARGINAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
GIVEN THE AMPLITUDE OF THE FLOW PTN PROGGED FOR THIS WEEK...EXPECT
THAT TIMING ADJUSTMENTS FOR THE EWD PROGRESS OF THE UPR TROF/CDFNT
SHOULD BE ANTICIPATED. NEVERTHELESS...THE LONG TERM FORECAST
FEATURES A CONTINUATION OF LIKELY POPS THROUGH THURSDAY FOLLOWED
BY CHC NMBRS INTO THE WEEKEND TO ACCOUNT FOR THE ADVN OF THE TROF
AND CURRENTLY PROGGED CUTOFF OVR THE GREAT LAKES REGION. PCPN AND
FRONTAL PASSAGE WL SPPRT TEMPS NR...THEN BLO THE SEASONAL AVGS FOR
THE PD.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
SCT MID CLOUDS AND A CANOPY OF CIRRUS DOMINATE THE FORECAST.
SHOWERS AND THUNDERSTORMS OVER IL/IA AS OF 23Z COULD HOLD TOGETHER
AND CROSS THE REGION DURING THE EARLY MORNING HOURS MONDAY
ACCORDING TO THE HRRR. DO NOT FORESEE ANYWHERE NEAR THE INTENSITY
THEY CURRENTLY HAVE...HOWEVER A BRIEF DROP TO MVFR VIS/CIGS IS
POSSIBLE. GIVEN CONFIDENCE IS LOW...DID NOT INCLUDE ANY PCPN
MENTION IN THE TERMINALS.
SHOWERS AND THUNDERSTORMS OVER WRN OH HAVE A LOW PROBABILITY OF
IMPACTING ZZV LATER TONIGHT...IF PCPN DOES OCCUR MVFR FOG IS
POSSIBLE TOWARD DAWN MONDAY MORNING.
.OUTLOOK.../00Z TUESDAY MONDAY THROUGH FRIDAY/...
MVFR AND PERHAPS BRIEF IFR WEATHER IS POSSIBLE IN SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF A COLD FRONT THAT CROSSES MID
WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
455 PM EDT SUN MAY 11 2014
.SYNOPSIS...
ALTHOUGH WARM WEATHER WILL QUICKLY RETURN...RAIN CHANCES WILL
INCREASE AS THE WEEK PROGRESSES.
&&
.NEAR TERM /THROUGH MONDAY/...
ONLY MADE A SLIGHT UPDATE TO ADJUST POPS THROUGH THE NEXT SEVERAL
HOURS BASED ON RECENT SATELLITE DATA AND RADAR TRENDS AS SOME
SHOWERS HAVE POPPED UP IN OHIO. THE HI RES MODELS CONTINUE TO
INDICATE THAT FURTHER DEVELOPMENT COULD OCCUR IN OHIO
TONIGHT...WITH THE HRRR BRINGING A SECOND WAVE OVER THE NORTHERN
COUNTIES TOWARDS MORNING. AS OF NOW HOWEVER...THE MESOANALYSIS
SHOWS THAT MUCH OF THE REGION REMAINS CAPPED. WILL MAINTAIN CHANCE
POPS THROUGH THE OVERNIGHT WITH ADVANCING WARM FRONT.
OTHERWISE FORECAST REMAINS ON TRACK.
PREVIOUS DISCUSSION FOLLOWS...
PRECIP CHANCES WILL CONTINUE THROUGH THE DAY ON
MONDAY...INCREASING DURING THE AFTERNOON AS INSTABILITY INCREASES
WITH DAYTIME HEATING. MOISTURE ADVECTION WILL INCREASE IN THE
RESULTING SOUTH/SOUTHWEST FLOW PUSHING PWAT VALUES BACK UP TO JUST
BELOW 1.5" WHICH IS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL
FOR THIS TIME OF YEAR. THERE IS A LARGE DIFFERENCE IN MODEL
FORECAST CAPE VALUES FOR MONDAY AFTERNOON RANGING FROM 500 TO 1500
J/KG...BUT IN ANY CASE WITH RELATIVELY WEAK SHEAR AND STORM MOTION
AROUND 15KTS...THE POTENTIAL FOR SEVERE WEATHER LOOKS LOW ATTM.
THE WARMING TREND IN TEMPERATURES WILL REMAIN INTACT AS RIDGING
CONTINUES TO BUILD ACROSS THE EASTERN CONUS THROUGH MONDAY AND LOW
PRESSURE DEEPENS OVER THE INTERMOUNTAIN WEST...WITH MAX
TEMPERATURES FORECAST TO BE APPROXIMATELY 15 DEGREES ABOVE NORMAL
ON MONDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
WITH THE WESTERN TOUGH SLOWLY TRANSITIONING EAST...NOT MUCH CHANGE
IS IN STORE FOR TUESDAY WITH MAX TEMPERATURES NOSING UP FURTHER
AND SHOWER/THUNDERSTORM CHANCES AGAIN MAINLY DURING THE AFTERNOON
AND EARLY EVENING. BY WEDNESDAY THE LONGWAVE TROUGH WILL HAVE
MOVED FAR ENOUGH EAST TO INCREASE DYNAMICS ACROSS THE FORECAST
AREA AND WITH PLENTY OF MOISTURE AND INSTABILITY ALREADY IN PLACE
IT LOOKS LIKELY THAT THERE WILL BE MORE WIDESPREAD THUNDERSTORM
COVERAGE. INCREASED DIRECTIONAL AND SPEED SHEAR ALOFT ALSO RAISES
THE POTENTIAL FOR MORE ORGANIZED CONVECTION BY WEDNESDAY...BUT
ATTM VALUES ARE STILL MARGINAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
GIVEN THE AMPLITUDE OF THE FLOW PTN PROGGED FOR THIS WEEK...EXPECT
THAT TIMING ADJUSTMENTS FOR THE EWD PROGRESS OF THE UPR TROF/CDFNT
SHOULD BE ANTICIPATED. NEVERTHELESS...THE LONG TERM FORECAST
FEATURES A CONTINUATION OF LIKELY POPS THROUGH THURSDAY FOLLOWED
BY CHC NMBRS INTO THE WEEKEND TO ACCOUNT FOR THE ADVN OF THE TROF
AND CURRENTLY PROGGED CUTOFF OVR THE GREAT LAKES REGION. PCPN AND
FRONTAL PASSAGE WL SPPRT TEMPS NR...THEN BLO THE SEASONAL AVGS FOR
THE PD.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
NO SIGNIFICANT WEATHER IS EXPECTED THE REMAINDER OF THE DAY WITH
GENERALLY LIGHT WINDS OUT OF THE SOUTHWEST AND SCT-BKN MID AND
UPPER LEVEL CLOUDS. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS
OVERNIGHT AS A WARM FRONT CROSSES THE REGION.
.OUTLOOK.../MONDAY THROUGH FRIDAY/...
SCATTERED RESTRICTIONS WILL BE POSSIBLE MONDAY AND TUESDAY IN
SHOWERS OR THUNDERSTORMS WITH MORE WIDESPREAD RESTRICTIONS ON
WEDNESDAY AS A COLD FRONT IMPACTS THE AREA.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
347 PM EDT SUN MAY 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 347 PM EDT SUN MAY 11 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW STRONG SHORTWAVE ENERGY
ROUNDING BASE OF AMPLIFIED TROF OVER THE FOUR CORNERS REGION OF THE
SW CONUS. MODELS SHOW THIS STRONG SHORTWAVE BEGINNING TO EJECT NE
FROM WRN/CENTRAL PLAINS TONIGHT AS ITS ASSOC SFC LOW LIFTS NE
THROUGH THE PLAINS. INCREASING MOISTURE AND ISENTROPIC ASCENT AHEAD
OF THIS LOW PRES SYSTEM SHOULD SIGNAL THE BEGINNING OF A FAIRLY WET
PERIOD FOR THE CWA STARTING LATE TONIGHT AND CONTINUING INTO EARLY
TUESDAY.
TONIGHT...AS THE STRONGER SHORTWAVE BEGINS TO EJECT OUT OF THE
DEEPENING UPPER TROF THE SFC LOW PRES WILL IN TURN LIFT NE THRU THE
PLAINS. THE EVENING SHOULD REMAIN DRY...AND PERHAPS CONTINUE INTO
THE OVERNIGHT OVER THE NE HALF OF THE FCST AREA CLOSER TO DRY
LOW-LEVEL NE TRAJECTORIES OUT OF SFC HIGH PRES IN ONTARIO. MOST OF
THE MODELS SHOW INCREASING 850-700 MB MOISTURE TRANSPORT AND
ADVECTION INTO THE AREA FM THE SOUTH BTWN 06-12Z ALONG WITH
INCREASING 300-305K WAA/ISENTROPIC ASCENT AHEAD OF THE APPROACHING
LOW PRES SYSTEM. MODELS ALSO INDICATE A SUBTLE SHORTWAVE WILL LIFT
NE INTO THE UPPER MISSISSIPPI VALLEY LATE TONIGHT THAT WILL FURTHER
AID THE DEVELOPMENT/SPREAD OF SHRA NE INTO UPPER MI DURING THE
OVERNIGHT. NOT MUCH INSTABILITY IS NOTED PER 0-3KM MUCAPE OFF THE
NAM/GFS. WITH A COUPLE HUNDRED J/KG AND SHOWALTER INDEX FALLING JUST
BLO 0C OVER THE FAR SCNTRL LATE TONIGHT IN MOST MODEL
GUIDANCE...WILL CONTINUE THE MENTION OF THUNDER IN THAT AREA LATE
TONIGHT.
MONDAY...WITH H85 WARM FRONT IN THE VICINITY...MODELS SHOW CONTINUED
MOISTURE TRANSPORT/ADVECTION AT H85-H7 ACROSS THE FRONTAL BOUNDARY
AS PWATS OVER OUR AREA RISE TO AROUND 1.5 INCHES OR WELL OVER 200
PCT OF NORMAL. SHORTWAVE/PV ANAMOLY EMERGING NORTHEAST OUT OF THE
WESTERN CONUS TROUGH WILL SPREAD AREA OF H85-H5 Q-VECTOR CONVERGENCE
INTO THE UPPER GREAT LAKES BY MONDAY AFTERNOON. DESPITE THESE
FAVORABLE FACTORS FOR SHOWERS...MODELS STILL DIFFER SOMEWHAT ON
PLACEMENT OF MAXIMUM MOISTURE ADVECTION...WITH THE GFS AND NAM
INDICATING BEST MOISTURE ADVECTION WEST AND THE REG GEM TO THE
EAST. HOWEVER CORFIDI VECTORS...BOTH FORWARD AND BACKWARD
PROPAGATING...ARE GENERALLY ORIENTED FROM WEST TO EAST ACROSS THE
FCST AREA WHICH WOULD ARGUE SHOWERS MAKING IT INTO THE WRN FCST AREA
SHOULD ADVECT INTO THE ERN COUNTIES AS WELL. GOING FCST LIKELY POPS
STILL SEEM REASONABLE CONSIDERING THE H85 FRONT IS IN THE VICINTY.
WILL CONTINUE IDEA OF LIKELY POPS WEST IN THE MORNING SPREADING EAST
INTO THE AFTERNOON HRS. ALSO WILL CONTINUE TO KEEP MENTION OF
TSRA MAINLY OVER SOUTH HALF INTO THE WESTERN CWA ALONG NORTHERN
GRADIENT OF ELEVATED INSTABILITY WITH SEVERAL HUNDRED J/KG OF
ELEVATED CAPE AND NEG SHOWALTER INDICES. BIGGEST THREAT WITH ANY
TSRA WILL BE HEAVY RAIN GIVEN HIGH PWATS ACROSS AREA. ANY HEAVY RAIN
OVER THE WRN COUNTIES WILL CONTINUE TO ADD MORE RUNOFF TO RIVERS
ALREADY RUNNING NEAR BANKFULL...ESPECIALLY THE STURGEON...TRAP ROCK
AND MICHIGAMME RIVERS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 329 PM EDT SUN MAY 11 2014
AT THE START OF THE PERIOD /00Z TUE/ MODELS ARE IN DECENT LARGE
SCALE AGREEMENT IN SHOWING A SHARP AND DEEP 500MB TROUGH FROM THE
SASK/MANITOBA BORDER S ACROSS THE DAKOTAS THEN TO THE FOUR CORNERS
REGION. A 1004MB SFC LOW WILL BE SOMEWHERE IN THE SERN MN TO NWRN
WI. MODELS HAVE BEEN TRENDING TOWARD THE CURRENT SOLUTION THAT TAKES
THE SFC LOW W OF THE CWA TO JUST N OF THE MN ARROWHEAD BY 12Z TUE.
WITH THE MORE NLY TRACK...MODELS ARE NOW SHOWING THE SFC WARM FRONT
MOVING INTO THE FAR SRN CWA MON NIGHT...BUT WITH COLD LAKE TEMPS AND
CONVECTION EXPECTED ALONG THE FRONT...CONFIDENCE IN THE FRONT MOVING
THAT FAR N IS LOW. FORCING FROM UPPER LEVEL HEIGHT FALLS FROM THE
DEEPENING TROUGH...GOOD MOISTURE TRANSPORT AND ISENTROPIC ASCENT
WILL FAVOR PERIODS OF MODERATE RAIN SHOWERS MON NIGHT INTO EARLY
TUE. THE OCCLUDED/COLD FRONT WILL MOVE THROUGH FROM LATE MON NIGHT
INTO TUE...BRINGING AN END TO THE BULK OF THE PRECIP. SOME SHOWERS
COULD REDEVELOP BEHIND THE FRONT AS CLEARING OVER THE WRN U.P. MAY
ALLOW FOR ENOUGH INSTABILITY. MODELS GENERALLY SHOW ADDITIONAL QPF
AMOUNTS OF AN INCH...BUT THAT WILL BE HIGHLY DEPENDENT ON EXACT
DETAILS OF CONVECTION...MAKING EXACT PRECIP AMOUNTS HIGHLY
UNCERTAIN. INSTABILITY FOR CONVECTION WILL ALSO BE HIGHLY UNCERTAIN
DUE TO DEPENDENCY ON WARM FRONTAL LOCATION AND OTHER CONVECTION. IF
THE FRONT CAN MAKE IT FARTHER N...THE WARM NOSE AT 900MB MAY BE
STRONG ENOUGH TO LEAD TO GREATER ELEVATED CONVECTION. GFS AND NAM
ARE SHOWING UP TO AROUND 1000 J/KG OF ELEVATED CAPE OVER THE
SCENTRAL CWA...BUT STILL THINK THAT IS NOT AS LIKELY AS THE FRONT
WILL PROBABLY STAY FARTHER S. IF THE WORST CASE SCENARIO OF THE
FARTHER N FRONTAL POSITION DOES OCCUR...SOME HAIL WOULD BE POSSIBLE
SCENTRAL. THE ADDITIONAL QPF AMOUNTS /COMBINED WITH PRECIP ON MON/
WOULD LIKELY LEAD TO ADDITIONAL FLOODING CONCERNS ON AREA RIVERS
THAT ALREADY HAVE ELEVATED LEVELS.
THE UPPER TROUGH MOVES OVERHEAD THROUGH MUCH OF THE REST OF THE WORK
WEEK...ALTHOUGH THE ECMWF CLOSES IT OFF INTO A LOW THU INTO FRI. THE
ECMWF SOLUTION WOULD RESULT IN MORE WIDESPREAD PRECIP THU INTO
FRI...BUT THE GFS AND GEM SOLUTIONS WITH THE OPEN TROUGH WOULD LEAD
TO SCATTERED SHOWER ACTIVITY MAINLY DURING PEAK HEATING WED THROUGH
FRI. THIS DUE TO 850MB TEMPS OF -2C TO -4C WED THROUGH FRI NIGHT
/AND AS COLD AS -7C IF THE ECMWF SOLUTION PANS OUT/. OF
COURSE...THIS WILL LEAD TO A RETURN OF SIGNIFICANTLY BELOW NORMAL
TEMPS /10-15 DEGREES BELOW NORMAL/.
NEXT WEEKEND LOOKS DRIER AND WARMER AS RIDGING MOVES OVERHEAD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 151 PM EDT SUN MAY 11 2014
LINGERING DRY AIR AT THE LOW LEVELS WILL ENSURE VFR CONDITIONS
CONTINUE AT KIWD/KCMX/KSAW INTO THE EVENING HRS. LATE TONIGHT...
NORTHWARD ADVANCING LOW PRESSURE AND A WARM FRONT WILL SPREAD SHRA
TOWARD THE UPPER LAKES. THERE IS STILL SOME UNCERTAINTY IN HOW FAST
PCPN WILL DEVELOP. KIWD HAS THE BEST CHC OF CONDITIONS FALLING TO
MVFR AROUND 08Z WITH THE ONSET OF RAIN. EXPECT ALL SITES TO QUICKLY
FALL TO IFR OR LIFR IN LOWERING STRATUS BY 12Z OR SHORTLY THEREAFTER
WITH CONTINUED SHOWERS AND ADVECTION OF HIGHER DEWPOINTS INTO THE
AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 347 PM EDT SUN MAY 11 2014
NE WINDS 15-25 KTS THIS EVENING WILL BEGIN TO INCREASE OVER WESTERN
PORTIONS OF LK SUPERIOR LATE TONIGHT AND MORE SO ON MONDAY AS LOW
PRESSURE APPROACHES FROM THE SOUTHWEST. DECIDED TO REPLACE GALE
WATCH WITH GALE WARNING OVER WESTERN TWO ZONES LATE TONIGHT THROUGH
TUE EVENING. WINDS OVER THE REST OF THE LAKE WILL STAY AT OR BLO 30
KTS. WINDS DIMINISH LATER MONDAY NIGHT AND THEN SWITCH TO THE WEST
TO 20-25 KTS ON TUESDAY. LOW SLOWLY SLIDES TO THE NORTHEAST OF LK
SUPERIOR REST OF THE WEEK...RESULTING IN NORTHWEST WINDS MAINLY
STAYING BLO 20 KTS.
&&
.HYDROLOGY...
ISSUED AT 329 PM EDT SUN MAY 11 2014
HIGHS MOSTLY IN THE 60S TODAY WILL RESULT IN ADDITIONAL SNOWMELT
OVER HIGHER TERRAIN OF NORTHERN UPR MICHIGAN. MINIMAL RAIN AMOUNTS
ARE EXPECTED THROUGH AT LEAST EARLY TONIGHT...BUT RAIN CHANCES
INCREASE LATE TONIGHT INTO TUESDAY MORNING. THERE IS A POTENTIAL FOR
MODERATE TO HEAVY RAIN OVER THE AREAS THAT ARE STILL MELTING
SNOW...SO THE RECENT HIGHER RIVER LEVELS WILL CONTINUE THROUGH MUCH
OF THE UPCOMING WEEK. THE FLOOD WARNING CONTINUES FOR THE STURGEON
RIVER NEAR CHASSELL...WHILE ADVISORIES ARE IN PLACE FOR OTHER
PORTIONS OF THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AS
WELL AS PORTIONS OF THE MICHIGAMME RIVER. IF HEAVIER RAINS
MATERIALIZE EARLY THIS WEEK... ADDITIONAL ADVISORIES AND WARNINGS
MAY BE NEEDED. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS
SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 6 AM EDT /5 AM CDT/ MONDAY TO MIDNIGHT EDT /11
PM CDT/ MONDAY NIGHT FOR LSZ162.
GALE WARNING FROM 10 AM TO 11 PM EDT MONDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...VOSS
MARINE...VOSS
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
330 PM EDT SUN MAY 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM EDT SUN MAY 11 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE HEADING SE
TOWARD THE SRN ROCKIES...LEADING THE TROF AMPLIFICATION DOWNSTREAM
OF ADVERTISED BUILDING RIDGE JUST OFF THE W COAST. DEEPENING TROF
AND SHORTWAVE WILL BRING THE NEXT ROUND OF WIDESPREAD WET WEATHER TO
THE UPPER GREAT LAKES...BEGINNING AS EARLY AS LATER TONIGHT. AHEAD
OF THE AMPLIFYING WRN TROF...A SHORTWAVE IS LIFTING THRU THE UPPER
MISSISSIPPI VALLEY. WITH LARGER SCALE RIDGE BUILDING OVER THE
MISSISSIPPI VALLEY/WRN LAKES DOWNSTREAM OF THE DEEPENING WRN
TROF...WAVE IS WEAKENING. LATEST RADAR IMAGERY SHOWS ISOLD/SCT
-SHRA ALONG THE MI/WI BORDER AREA. WITH VERY DRY MASS OVER
THE AREA (NOTE THE VERY DRY COLUMN SAMPLED BY 00Z KGRB SOUNDING)...
PCPN HAS BEEN ON THE LIGHT SIDE WITH MUCH OF IT NOT MORE THAN
SPRINKLES.
SOMEWHAT SURPRISED THAT -SHRA/SPRINKLES ARE HOLDING TOGETHER GIVEN
THE ANTECEDANT DRY AIR MASS AND THE SHORTWAVE/FORCING WEAKENING
UNDER DEVELOPING HEIGHT RISES. IN ANY EVENT...ISOLD/SCT
-SHRA/SPRINKLES SHOULD MOVE NE ACROSS ALL BUT THE FAR ERN FCST AREA
DURING THE MORNING. AFTER THE MORNING HRS...EXPECT A DRY AFTN UNDER
CONTINUED HEIGHT RISES AS RIDGE BUILDS THRU THE WRN GREAT LAKES
DOWNSTREAM OF ROCKIES TROF. YESTERDAY...A NUMBER OF MODELS WERE
SUGGESTING SOME AFTN CONVECTION...ESPECIALLY THE NAM. THAT IDEA WAS
DISREGARDED AS MODELS WERE OVERFORECASTING LOW-LEVEL MOISTURE AND
THUS INSTABILITY. WELL...TODAYS 00Z MODELS RUNS ARE ALMOST ALL
ONBOARD WITH A DRY AFTN AS A RESULT OF CORRECTING THE
MOISTURE/INSTABILITY DOWNWARD. CLOUDS WILL THIN SOME IN THE
AFTN...ALLOWING TEMPS TO RISE WELL INTO THE 60S TO AROUND 70F AWAY
FROM LAKE MODERATION.
AS STRONGER SHORTWAVE BEGINS TO EJECT OUT OF DEEPENING UPPER TROF
DRIFTING TOWARD THE WRN PLAINS TONIGHT...SFC LOW PRES WILL BEGIN TO
LIFT NE THRU THE PLAINS. ALTHOUGH THE EVENING MAY BE DRY...
ESPECIALLY OVER THE NE HALF OF THE FCST AREA CLOSER TO DRY LOW-LEVEL
NE TRAJECTORIES OUT OF SFC HIGH PRES IN ONTARIO...MOST OF THE MODELS
SHOW HIGHER MID LEVEL RH AND PCPN ARRIVING FROM THE SW THRU THE
NIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS N. THERE ARE
INDICATIONS OF A SUBTLE SHORTWAVE LIFTING NE INTO THE UPPER
MISSISSIPPI VALLEY LATE TONIGHT...AND THAT WILL FURTHER AID THE
DEVELOPMENT/SPREAD OF SHRA NE INTO UPPER MI DURING THE OVERNIGHT.
NOT MUCH INSTABILITY IS NOTED PER 0-3KM MUCAPE OFF THE NAM/GFS. WITH
A COUPLE HUNDRED J/KG AND SHOWALTER INDEX FALLING JUST BLO 0 OVER
THE FAR SCNTRL LATE TONIGHT IN MOST MODEL GUIDANCE...WILL INCLUDE A
THUNDER MENTION IN THAT AREA LATE TONIGHT.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 329 PM EDT SUN MAY 11 2014
AT THE START OF THE PERIOD /00Z TUE/ MODELS ARE IN DECENT LARGE
SCALE AGREEMENT IN SHOWING A SHARP AND DEEP 500MB TROUGH FROM THE
SASK/MANITOBA BORDER S ACROSS THE DAKOTAS THEN TO THE FOUR CORNERS
REGION. A 1004MB SFC LOW WILL BE SOMEWHERE IN THE SERN MN TO NWRN
WI. MODELS HAVE BEEN TRENDING TOWARD THE CURRENT SOLUTION THAT TAKES
THE SFC LOW W OF THE CWA TO JUST N OF THE MN ARROWHEAD BY 12Z TUE.
WITH THE MORE NLY TRACK...MODELS ARE NOW SHOWING THE SFC WARM FRONT
MOVING INTO THE FAR SRN CWA MON NIGHT...BUT WITH COLD LAKE TEMPS AND
CONVECTION EXPECTED ALONG THE FRONT...CONFIDENCE IN THE FRONT MOVING
THAT FAR N IS LOW. FORCING FROM UPPER LEVEL HEIGHT FALLS FROM THE
DEEPENING TROUGH...GOOD MOISTURE TRANSPORT AND ISENTROPIC ASCENT
WILL FAVOR PERIODS OF MODERATE RAIN SHOWERS MON NIGHT INTO EARLY
TUE. THE OCCLUDED/COLD FRONT WILL MOVE THROUGH FROM LATE MON NIGHT
INTO TUE...BRINGING AN END TO THE BULK OF THE PRECIP. SOME SHOWERS
COULD REDEVELOP BEHIND THE FRONT AS CLEARING OVER THE WRN U.P. MAY
ALLOW FOR ENOUGH INSTABILITY. MODELS GENERALLY SHOW ADDITIONAL QPF
AMOUNTS OF AN INCH...BUT THAT WILL BE HIGHLY DEPENDENT ON EXACT
DETAILS OF CONVECTION...MAKING EXACT PRECIP AMOUNTS HIGHLY
UNCERTAIN. INSTABILITY FOR CONVECTION WILL ALSO BE HIGHLY UNCERTAIN
DUE TO DEPENDENCY ON WARM FRONTAL LOCATION AND OTHER CONVECTION. IF
THE FRONT CAN MAKE IT FARTHER N...THE WARM NOSE AT 900MB MAY BE
STRONG ENOUGH TO LEAD TO GREATER ELEVATED CONVECTION. GFS AND NAM
ARE SHOWING UP TO AROUND 1000 J/KG OF ELEVATED CAPE OVER THE
SCENTRAL CWA...BUT STILL THINK THAT IS NOT AS LIKELY AS THE FRONT
WILL PROBABLY STAY FARTHER S. IF THE WORST CASE SCENARIO OF THE
FARTHER N FRONTAL POSITION DOES OCCUR...SOME HAIL WOULD BE POSSIBLE
SCENTRAL. THE ADDITIONAL QPF AMOUNTS /COMBINED WITH PRECIP ON MON/
WOULD LIKELY LEAD TO ADDITIONAL FLOODING CONCERNS ON AREA RIVERS
THAT ALREADY HAVE ELEVATED LEVELS.
THE UPPER TROUGH MOVES OVERHEAD THROUGH MUCH OF THE REST OF THE WORK
WEEK...ALTHOUGH THE ECMWF CLOSES IT OFF INTO A LOW THU INTO FRI. THE
ECMWF SOLUTION WOULD RESULT IN MORE WIDESPREAD PRECIP THU INTO
FRI...BUT THE GFS AND GEM SOLUTIONS WITH THE OPEN TROUGH WOULD LEAD
TO SCATTERED SHOWER ACTIVITY MAINLY DURING PEAK HEATING WED THROUGH
FRI. THIS DUE TO 850MB TEMPS OF -2C TO -4C WED THROUGH FRI NIGHT
/AND AS COLD AS -7C IF THE ECMWF SOLUTION PANS OUT/. OF
COURSE...THIS WILL LEAD TO A RETURN OF SIGNIFICANTLY BELOW NORMAL
TEMPS /10-15 DEGREES BELOW NORMAL/.
NEXT WEEKEND LOOKS DRIER AND WARMER AS RIDGING MOVES OVERHEAD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 151 PM EDT SUN MAY 11 2014
LINGERING DRY AIR AT THE LOW LEVELS WILL ENSURE VFR CONDITIONS
CONTINUE AT KIWD/KCMX/KSAW INTO THE EVENING HRS. LATE TONIGHT...
NORTHWARD ADVANCING LOW PRESSURE AND A WARM FRONT WILL SPREAD SHRA
TOWARD THE UPPER LAKES. THERE IS STILL SOME UNCERTAINTY IN HOW FAST
PCPN WILL DEVELOP. KIWD HAS THE BEST CHC OF CONDITIONS FALLING TO
MVFR AROUND 08Z WITH THE ONSET OF RAIN. EXPECT ALL SITES TO QUICKLY
FALL TO IFR OR LIFR IN LOWERING STRATUS BY 12Z OR SHORTLY THEREAFTER
WITH CONTINUED SHOWERS AND ADVECTION OF HIGHER DEWPOINTS INTO THE
AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT SUN MAY 11 2014
WINDS LESS THAN 20 KTS THROUGH THIS EVENING. WINDS BEGIN TO INCREASE
OVER WESTERN PORTIONS OF LK SUPERIOR LATE TONIGHT AND MORE SO ON
MONDAY AS LOW PRESSURE APPROACHES FROM THE SOUTHWEST. FREQUENT GALE
GUSTS APPEAR LIKELY OVER FAR WEST...SO HAVE ISSUED A GALE WATCH.
WINDS OVER THE REST OF THE LAKE WILL STAY AT OR BLO 30 KTS. WINDS
DIMINISH LATER MONDAY NIGHT AND THEN SWITCH TO THE WEST TO 20-25 KTS
ON TUESDAY. LOW SLOWLY SLIDES TO THE NORTHEAST OF LK SUPERIOR REST
OF THE WEEK...RESULTING IN NORTHWEST WINDS MAINLY STAYING BLO 20 KTS.
&&
.HYDROLOGY...
ISSUED AT 329 PM EDT SUN MAY 11 2014
HIGHS MOSTLY IN THE 60S TODAY WILL RESULT IN ADDITIONAL SNOWMELT
OVER HIGHER TERRAIN OF NORTHERN UPR MICHIGAN. MINIMAL RAIN AMOUNTS
ARE EXPECTED THROUGH AT LEAST EARLY TONIGHT...BUT RAIN CHANCES
INCREASE LATE TONIGHT INTO TUESDAY MORNING. THERE IS A POTENTIAL FOR
MODERATE TO HEAVY RAIN OVER THE AREAS THAT ARE STILL MELTING
SNOW...SO THE RECENT HIGHER RIVER LEVELS WILL CONTINUE THROUGH MUCH
OF THE UPCOMING WEEK. THE FLOOD WARNING CONTINUES FOR THE STURGEON
RIVER NEAR CHASSELL...WHILE ADVISORIES ARE IN PLACE FOR OTHER
PORTIONS OF THE STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AS
WELL AS PORTIONS OF THE MICHIGAMME RIVER. IF HEAVIER RAINS
MATERIALIZE EARLY THIS WEEK... ADDITIONAL ADVISORIES AND WARNINGS
MAY BE NEEDED. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS
SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 6 AM EDT /5 AM CDT/ MONDAY TO MIDNIGHT EDT /11
PM CDT/ MONDAY NIGHT FOR LSZ162.
GALE WARNING FROM 10 AM TO 11 PM EDT MONDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...JLA
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
204 PM EDT SUN MAY 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM EDT SUN MAY 11 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE HEADING SE
TOWARD THE SRN ROCKIES...LEADING THE TROF AMPLIFICATION DOWNSTREAM
OF ADVERTISED BUILDING RIDGE JUST OFF THE W COAST. DEEPENING TROF
AND SHORTWAVE WILL BRING THE NEXT ROUND OF WIDESPREAD WET WEATHER TO
THE UPPER GREAT LAKES...BEGINNING AS EARLY AS LATER TONIGHT. AHEAD
OF THE AMPLIFYING WRN TROF...A SHORTWAVE IS LIFTING THRU THE UPPER
MISSISSIPPI VALLEY. WITH LARGER SCALE RIDGE BUILDING OVER THE
MISSISSIPPI VALLEY/WRN LAKES DOWNSTREAM OF THE DEEPENING WRN
TROF...WAVE IS WEAKENING. LATEST RADAR IMAGERY SHOWS ISOLD/SCT
-SHRA ALONG THE MI/WI BORDER AREA. WITH VERY DRY MASS OVER
THE AREA (NOTE THE VERY DRY COLUMN SAMPLED BY 00Z KGRB SOUNDING)...
PCPN HAS BEEN ON THE LIGHT SIDE WITH MUCH OF IT NOT MORE THAN
SPRINKLES.
SOMEWHAT SURPRISED THAT -SHRA/SPRINKLES ARE HOLDING TOGETHER GIVEN
THE ANTECEDANT DRY AIR MASS AND THE SHORTWAVE/FORCING WEAKENING
UNDER DEVELOPING HEIGHT RISES. IN ANY EVENT...ISOLD/SCT
-SHRA/SPRINKLES SHOULD MOVE NE ACROSS ALL BUT THE FAR ERN FCST AREA
DURING THE MORNING. AFTER THE MORNING HRS...EXPECT A DRY AFTN UNDER
CONTINUED HEIGHT RISES AS RIDGE BUILDS THRU THE WRN GREAT LAKES
DOWNSTREAM OF ROCKIES TROF. YESTERDAY...A NUMBER OF MODELS WERE
SUGGESTING SOME AFTN CONVECTION...ESPECIALLY THE NAM. THAT IDEA WAS
DISREGARDED AS MODELS WERE OVERFORECASTING LOW-LEVEL MOISTURE AND
THUS INSTABILITY. WELL...TODAYS 00Z MODELS RUNS ARE ALMOST ALL
ONBOARD WITH A DRY AFTN AS A RESULT OF CORRECTING THE
MOISTURE/INSTABILITY DOWNWARD. CLOUDS WILL THIN SOME IN THE
AFTN...ALLOWING TEMPS TO RISE WELL INTO THE 60S TO AROUND 70F AWAY
FROM LAKE MODERATION.
AS STRONGER SHORTWAVE BEGINS TO EJECT OUT OF DEEPENING UPPER TROF
DRIFTING TOWARD THE WRN PLAINS TONIGHT...SFC LOW PRES WILL BEGIN TO
LIFT NE THRU THE PLAINS. ALTHOUGH THE EVENING MAY BE DRY...
ESPECIALLY OVER THE NE HALF OF THE FCST AREA CLOSER TO DRY LOW-LEVEL
NE TRAJECTORIES OUT OF SFC HIGH PRES IN ONTARIO...MOST OF THE MODELS
SHOW HIGHER MID LEVEL RH AND PCPN ARRIVING FROM THE SW THRU THE
NIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS N. THERE ARE
INDICATIONS OF A SUBTLE SHORTWAVE LIFTING NE INTO THE UPPER
MISSISSIPPI VALLEY LATE TONIGHT...AND THAT WILL FURTHER AID THE
DEVELOPMENT/SPREAD OF SHRA NE INTO UPPER MI DURING THE OVERNIGHT.
NOT MUCH INSTABILITY IS NOTED PER 0-3KM MUCAPE OFF THE NAM/GFS. WITH
A COUPLE HUNDRED J/KG AND SHOWALTER INDEX FALLING JUST BLO 0 OVER
THE FAR SCNTRL LATE TONIGHT IN MOST MODEL GUIDANCE...WILL INCLUDE A
THUNDER MENTION IN THAT AREA LATE TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 454 AM EDT SUN MAY 11 2014
AGREEMENT IS HIGH IN OVERALL LARGER SCALE PATTERN FOR THE UPCOMING
WEEK. FLOW IS HIGHLY AMPLIFIED. INITIALY THIS WEEK TROUGH OVER THE
WESTERN CONUS THIS MORNING SLIDES ACROSS THE CENTRAL CONUS. SFC-H85
LOW PRESSURE BEGINS TO FORM TODAY OVER THE SOUTHERN PLAINS AND THIS
LOW LIFTS TOWARD UPPER MISSISSIPPI RIVER VALLEY BY DAYBREAK ON
MONDAY. SFC WARM FRONT SHOULD STAY SOUTH OF UPR MICHIGAN...MAINLY
OVER SOUTHERN/CENTRAL WI ACROSS CENTRAL LOWER MICHIGAN. EASTERLY
LOW-LEVEL WINDS OFF THE COLD GREAT LAKES TO THE NORTH OF THE FRONT
ALONG WITH SHRA/TSRA FIRING ALONG THE FRONT SHOULD KEEP THE WARM
FRONT FROM MOVING INTO UPR MICHIGAN ON MONDAY. WARM FRONT SOUTH OF
HERE ALONG WITH EASTERLY WINDS SHOULD KEEP TEMPS COOLER ON MONDAY
THAN THIS WEEKEND.
H85 WARM FRONT WILL BE IN THE VICINITY THOUGH AND THERE IS MOISTURE
TRANSPORT AT H85-H7 AIMED INTO THE H85 FRONT ALLOWING PWATS OVER 1.5
INCHES OR WELL OVER 200 PCT OF NORMAL TO PUSH NORTHWARD ACROSS UPPER
GREAT LAKES REGION. SHORTWAVE/PV ANAMOLY EMERGING NORTHEAST OUT OF
THE LARGE WESTERN CONUS TROUGH RESULTS IN AREA OF H85-H5 Q-VECTOR
CONVERGENCE SPREADING OVER UPPER GREAT LAKES ON MONDAY. ADDITIONAL
LIFT WILL BE PROVIDED VIA 250MB JET STREAK LIFTING NNE-SSW AHEAD OF
MAIN TROUGH AND ALSO ANOTHER SLIDING WNW-ESE OVER NORTHERN ONTARIO
TOWARD QUEBEC. AT FIRST GLANCE...A LOT OF THINGS ARE FAVORABLE FOR
MULTIPLE PERIODS OF SHOWERS OVER UPR MICHIGAN ON MONDAY. YET...THE
INSTABILITY BOTH ELEVATED /1-6KM MUCAPE/ AND AT THE SFC /MLCAPE/ IS
NOT AS FAVORABLE...WITH GRADIENT OF BOTH TO SOUTH AND SOUTHWEST OF
UPR MICHIGAN THROUGH THE DAY. MODELS DIFFER ON PLACEMENT OF MAXIMUM
MOISTURE ADVECTION AND THIS WILL HAVE DIRECT BEARING ON WHETHER
WESTERN HALF OF CWA OR EASTERN HALF OF CWA SEES MOST RAIN ON MONDAY.
TOUGH TO TELL AT THIS POINT WHICH IDEA WILL BE CORRECT. CORFIDI
VECTORS...BOTH FORWARD AND BACKWARD PROPAGATING...ARE ORIENTED
GENERALLY FROM WEST TO EAST ALONG AND SOUTH OF UPR MICHIGAN...WHICH
LIKELY WILL KEEP PERIODS OF PERSISTENT/HEAVIEST SHRA/TSRA TO SOUTH
OF THE AREA SINCE THAT IS WHERE PRIME GENESIS REGION FOR SHRA/TSRA
WILL BE ALONG THE SFC WARM FRONT. PERFER THE LOOK OF THE ECMWF/UKMET
WHICH KEEP THE TRACK OF HIGHEST QPF ONLY OVER SCNTRL CWA...WITH
LIGHTER AMOUNTS FARTHER NORTH AWAY FM THE SFC WARM FRONT. EVEN
SO...GOING LIKELY POPS SEEM ON TRACK WITH H85 FRONT IN VICINTY.
KEPT SMALL MENTION OF TSRA MAINLY OVER SOUTH HALF INTO THE EASTERN
CWA ALONG NORTH GRADIENT OF ELEVATED INSTABILITY. SPC DAY2 SEVERE
RISK KEEPS SLIGHT PROBABILITIES FARTHER SOUTH...BUT DOES HIGHLIGHT
SOUTHERN TIER OF CWA FOR A 5 PCT RISK.
NEXT SURGE OF SHRA/TSRA DEVELOP MONDAY NIGHT IN RESPONSE TO
SHARPENING TROUGH ALOFT. SFC LOW HAS TRENDED FARTHER NORTH OVER TIME
WITH SFC LOW LIFTING ACROSS WESTERN LK SUPERIOR BY TUESDAY MORNING.
BEFORE THAT...LARGE SCALE ASCENT DEVELOPS DUE TO THE DEEPENING OF
TROUGH ALOFT AND INCREASINGLY DIFFLUENT FLOW ALOFT. THOUGH SFC WARM
FRONT STAYS MAINLY SOUTH OF UPR MICHIGAN...H85 WARM FRONT WILL
PROVIDE MAIN FOCUS FOR SHRA/TSRA MONDAY NIGHT INTO TUESDAY MORNING
AS ANOTHER SURGE OF H85-H7 MOISTURE ADVECTION INTERSECTS THE
BOUNDARY. GFS SEEMS TOO QUICK IN SLIDING THIS WHOLE SYSTEM TO THE
EAST. ECMWF/UKMET AND GEM-NH ARE SLOWER WHICH MAKES SENSE WITH THE
SHARPER TROUGH ALOFT. GIVEN PWATS STILL OVER 200 PCT OF
NORMAL...MODERATE TO HEAVY RAIN COULD OCCUR. DECENT SIGNAL FROM
PREFERRED MODELS THAT HEAVIEST RAIN IMPACTS MAINLY NORTHERN
CWA...INCLUDING THE KEWEENAW PENINSULA. OBVIOUSLY WITH THE SNOWMELT
AND HIGHER RIVER FLOWS THAT ARE CURRENTLY OCCURRING THIS WOULD NOT BE
A GOOD SITUATION IF IT WORKED OUT THIS WAY. SIMILAR TO FORECAST ON
MONDAY...SINCE THE SFC WARM FRONT IS STILL SOUTH OF THE AREA...SFC
SHRA/TSRA ONGOING ALONG THE FRONT COULD VERY WELL IMPACT THIS ENTIRE
SCENARIO...ESPECIALLY AS STORM MOTIONS ARE FORECAST TO BE FROM SW-
NE...SUGGESTING THAT IF CLUSTER OF STORMS FORM FARTHER SOUTH CLOSER
TO SFC WARM FRONT THEY COULD GLIDE OVER EASTERN CWA AND GENERALLY
BYPASS THE WESTERN CWA. CONDIFENCE IN ANY OF THESE TYPE OF DETAILS
REMAINS LOW ATTM.
AS THE SFC LOW LIFTS NORTH OF LK SUPERIOR BY TUESDAY AFTN...EXPECT
DRYING TO SPREAD IN FROM THE WEST...DIMINISHING THEN SHUTTING OFF
ADDITIONAL PRECIPITATION. THOUGH SKIES WILL NOT COMPLETELY CLEAR OUT
AS A LOT OF H85 MOISTURE REMAINS...EVEN SHALLOW MIXING WITH THE WEST
LOW-LEVEL WINDS SHOULD RESULT IN TEMPS PUSHING INTO THE 60S OVER ALL
BUT THE FAR WEST/NORTHWEST AND EAST CWA.
QUESTION FOR THE REST OF THE WEEK IS NOT IF IT WILL BE COOL AND
UNSETTLED BUT TO WHAT DEGREE. ECMWF IS BACK TO SHOWING A VERY DEEP
TROUGH ALOFT THURSDAY INTO FRIDAY...EVEN TO THE POINT OF BECOMING
CLOSED OFF AROUND THURSDAY. PREVIOUS RUNS OF ECMWF HAD BACKED AWAY
FM STRONGER WAVE WRAPPING AROUND THE EDGE OF THE TROUGH LATE THIS
WEEK BUT NOW ITS BACK. GIVEN H85 TEMPS -2C TO -4C FALLING TO BLO -6C
AS THIS WAVE LIFTS OVER THE REGION...CERTAINLY POSSIBLE THAT SOME
SNOW COULD OCCUR THURSDAY INTO FRIDAY FOR ALMOSTL ANYWHERE IN THE
CWA. CONSENSUS OF THAT WRAPPED UP ECMWF SOLUTION ALONG WITH OTHER
AVAILABLE MEDIUM RANGE MODELS RESULTED IN LOW CHANCES ATTM...WITH
MOST MENTION OF SNOW ONLY OCCURRING LATER AT NIGHT INTO THE MORNING
BEFORE BLYR WARMS ENOUGH FOR JUST RAIN. SYSTEM WILL BE SOMETHING TO
KEEP EYE ON AS WE GET LATER INTO THE WEEK. AT THE LEAST EVEN IF WE
GET BY WITHOUT SEEING ANY SNOW...TEMPS WILL FALL TO WELL BELOW
NORMAL VALUES AGAIN. HIGHS MID-LATE WEEK LIKELY WILL STAY IN THE 40S
OVER MUCH OF NORTHERN UPR MICHIGAN CLOSER TO LK SUPERIOR AND ONLY IN
THE 50S OVER SOUTHERN CWA. NIGHTTIME LOWS WILL BE AROUND FREEZING
FOR MUCH OF THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 151 PM EDT SUN MAY 11 2014
LINGERING DRY AIR AT THE LOW LEVELS WILL ENSURE VFR CONDITIONS
CONTINUE AT KIWD/KCMX/KSAW INTO THE EVENING HRS. LATE TONIGHT...
NORTHWARD ADVANCING LOW PRESSURE AND A WARM FRONT WILL SPREAD SHRA
TOWARD THE UPPER LAKES. THERE IS STILL SOME UNCERTAINTY IN HOW FAST
PCPN WILL DEVELOP. KIWD HAS THE BEST CHC OF CONDITIONS FALLING TO
MVFR AROUND 08Z WITH THE ONSET OF RAIN. EXPECT ALL SITES TO QUICKLY
FALL TO IFR OR LIFR IN LOWERING STRATUS BY 12Z OR SHORTLY THEREAFTER
WITH CONTINUED SHOWERS AND ADVECTION OF HIGHER DEWPOINTS INTO THE
AREA. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT SUN MAY 11 2014
WINDS LESS THAN 20 KTS THROUGH THIS EVENING. WINDS BEGIN TO INCREASE
OVER WESTERN PORTIONS OF LK SUPERIOR LATE TONIGHT AND MORE SO ON
MONDAY AS LOW PRESSURE APPROACHES FROM THE SOUTHWEST. FREQUENT GALE
GUSTS APPEAR LIKELY OVER FAR WEST...SO HAVE ISSUED A GALE WATCH.
WINDS OVER THE REST OF THE LAKE WILL STAY AT OR BLO 30 KTS. WINDS
DIMINISH LATER MONDAY NIGHT AND THEN SWITCH TO THE WEST TO 20-25 KTS
ON TUESDAY. LOW SLOWLY SLIDES TO THE NORTHEAST OF LK SUPERIOR REST
OF THE WEEK...RESULTING IN NORTHWEST WINDS MAINLY STAYING BLO 20 KTS.
&&
.HYDROLOGY...
ISSUED AT 454 AM EDT SUN MAY 11 2014
HIGHS MOSTLY IN THE 60S TODAY WILL RESULT IN ADDITIONAL SNOWMELT
OVER HIGHER TERRAIN OF NORTHERN UPR MICHIGAN. MINIMAL RAIN AMOUNTS
ARE EXPECTED THROUGH MUCH OF TONIGHT...BUT THEN RAIN CHANCES INCREASE
MONDAY/MONDAY NIGHT AND INTO TUESDAY MORNING. THERE IS A POTENTIAL
FOR MODERATE TO HEAVY RAIN OVER THE AREAS THAT ARE STILL MELTING
SNOW...SO THE RECENT HIGHER RIVER LEVELS WILL CONTINUE THROUGH MUCH
OF THE UPCOMING WEEK. THE FLOOD WARNING CONTINUES FOR THE STURGEON
RIVER NEAR CHASSELL...WHILE ADVISORIES ARE IN PLACE FOR THE STURGEON
RIVER NEAR ALSTON...AND THE MICHIGAMME RIVER NEAR WITCH LAKE AND
ALSO NEAR REPUBLIC. IF HEAVIER RAINS MATERIALIZE EARLY THIS WEEK...
ADDITIONAL ADVISORIES AND WARNINGS MAY BE NEEDED. THOSE LIVING NEAR
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST
RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
135 PM EDT SUN MAY 11 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 328 AM EDT SUN MAY 11 2014
HIGH PRESSURE WILL SLIP EAST AND ALLOW A FRONTAL SYSTEM TO MOVE
BACK INTO THE AREA TONIGHT. AS THIS SYSTEM MOVES BACK IN SHOWERS
AND THUNDERSTORMS WILL BECOME MORE LIKELY THIS EVENING INTO
TUESDAY EVENING. WARMER AIR WILL MOVE INTO THE AREA FOR THE FIRST
COUPLE OF DAYS OF THE NEW WORK WEEK BEFORE COLDER AIR MOVES IN
BEHIND THE SYSTEM FOR LATE IN THE WEEK.
&&
.UPDATE...
ISSUED AT 1047 AM EDT SUN MAY 11 2014
WILL ISSUE A FCST UPDATE TO LOWER/DELAY THE CHANCE OF RAIN TODAY
AND TO BE MORE OPTIMISTIC WITH CLOUD COVER BASED ON CURRENT
SATELLITE/RADAR TRENDS AS WELL AS LATEST HRRR GUIDANCE. WILL ONLY
CARRY A 20 POP AFTER 5 PM SOUTH OF I-96 WHERE LEADING EDGE OF
BETTER MOISTURE/INSTABILITY WILL BE NOSING IN LATER IN THE DAY.
NEW 12Z NAM SHOWS LLJ FOCUSING FARTHER WEST TONIGHT AND AIMED INTO
IOWA/SRN MN/SW WI. MAY HAVE TO CONSIDER LOWERING POPS TONIGHT AS
WELL BUT WILL WAIT ON ADDITIONAL GUIDANCE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 328 AM EDT SUN MAY 11 2014
MAIN FOCUS OF THE SHORT TERM CONTINUES TO BE CONVECTIVE TRENDS AND
SEVERE WEATHER POTENTIAL THROUGH THE PERIOD. THERE ARE NO REAL
CHANGES TO THE FCST.
THE QUIETEST PERIOD OF THE SHORT TERM WILL BE THE FIRST PERIOD
TODAY. THE CWFA REMAINS DRY AS OF 07Z THIS MORNING...HOWEVER WE ARE
EXPECTING AT LEAST A FEW LIGHT SHOWERS TO DEVELOP AND ROLL IN LATER
THIS MORNING AND THIS AFTERNOON. THIS WILL OCCUR AS A LLJ OF 35+
KNOTS FUELING A FEW SHOWERS AN ISOLATED THUNDER NEAR THE QUAD CITIES
WILL TRANSLATE EAST THROUGH 18Z. THIS LLJ WILL BE WEAKENING AND WILL
BE BATTLING A FAIR AMOUNT OF DRY AIR INITIALLY OVER THE AREA.
WE WILL SEE A BETTER POTENTIAL OF STORMS DEVELOP THIS EVENING ACROSS
THE SOUTH...AND EVENTUALLY THE CHCS WILL SPREAD NORTH THROUGH THE
NIGHT TONIGHT. A STALLED OUT FRONT CURRENTLY ACROSS IL/IN/OH WILL
STRENGTHEN THIS EVENING AS BETTER WARMTH AND MOISTURE ADVECTS NORTH
OUT OF THE GULF OF MEXICO. WE WILL SEE ANOTHER LLJ INCREASE TO
AROUND 30-35 KNOTS AND NOSE UP INTO THE HEART OF THE CWFA. THE
STORMS SHOULD START OUT AS MAINLY ELEVATED WITH THE FRONT TO OUR
SOUTH INITIALLY. FCST SOUNDINGS SHOW THAT HAIL LOOKS LIKE THE BEST
THREAT WITH A GOOD DEAL OF CAPE IN THE -10C TO -30C LAYER. DAMAGING
WINDS ARE POSSIBLE...HOWEVER A BIT LIMITED DUE TO THE ELEVATED
NATURE OF THE STORMS.
WE EXPECT THAT WAVES OF STORMS WILL REMAIN POSSIBLE THROUGH MON AND
INTO MON EVENING. THE FRONT IS EXPECTED TO GET HELD UP GENERALLY
AROUND THE I-96 CORRIDOR AS IT WILL WAIT FOR A GOOD PUSH IN THE MID
LEVELS AS THE WRN TROUGH STARTS TO LIFT OUT. A 25-30 KNOT LLJ WILL
GENERALLY REMAIN IN PLACE THROUGH THAT PERIOD WHICH WILL HELP TO
FEED THE FORCING AND MOISTURE/WARMTH INTO THE AREA. IT LOOKS LIKE
ALONG OR JUST NORTH OF THE I-96 CORRIDOR WILL SEE THE HIGHEST RAIN
AMOUNTS. WHAT WILL BE INTERESTING IS THE POTENTIAL OF SOME SFC BASED
INSTABILITY ON MON SOUTH OF THE FRONT. THIS COULD ENHANCE THE THREAT
OF SOME SEVERE WX ALONG WITH DEEP LAYER SHEAR VALUES AT OR ABOVE
30.
WE SHOULD SEE A BREAK IN THE MORE WIDESPREAD SHOWER AND STORM
ACTIVITY THEN FOR THE SECOND HALF OF MON NIGHT. WE FINALLY SEE THE
TROUGH OUT WEST DIG ENOUGH THAT THE RIDGE BUILDS IN OUR
NEIGHBORHOOD. THIS WILL PUSH THE WARM FRONT WELL NORTH OF THE AREA
BY TUE.
SHOWERS AND STORMS BECOME MORE NUMEROUS ON TUE ONCE AGAIN AS THE
COLD FRONT AND WHAT LOOKS LIKE A THERMAL TROUGH DEVELOPS INLAND
AND BEGINS TO PUSH THROUGH THE AREA. WE PREFER THE SLOWER FOREIGN
MODEL SOLUTIONS AS THE FRONT LOOKS TO BE FAIRLY PARALLEL WITH THE
UPPER JET. THIS WOULD BRING THE FRONT THROUGH DURING THE DAY WHEN
SOME DIURNAL INSTABILITY WILL BE POSSIBLE. DEEP LAYER SHEAR WILL
ONCE AGAIN BE SUFFICIENT FOR ORGANIZED STORMS WITH VALUES OVER 30
AND INCREASING THAT DAY. FCST SOUNDINGS DO LOOK QUITE CLOUDY WITH A
LOT OF MOISTURE...WHICH WOULD LIMIT THE SEVERE POTENTIAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 328 AM EDT SUN MAY 11 2014
LOOKS LIKE A PRETTY UNSETTLED PERIOD WITH COLD AND SHOWERY WEATHER
BY THE END OF THE WEEK UNDER AN UPPER LOW. WILL HAVE TO WATCH
CLOSELY FOR ANY CLEARING OUT ON THURSDAY NIGHT OR FRIDAY NIGHT WHICH
WOULD RESULT IN WIDESPREAD FROST/FREEZE CONDITIONS GIVEN HOW COLD IT
WILL BE.
COLD FRONT PUSHES EAST TUESDAY NIGHT. MODEL DIFFERENCES BETWEEN THE
00Z RUNS OF THE GFS AND ECMWF ARE THE SAME AS THEY HAVE BEEN THE
LAST FEW DAYS WITH THE ECMWF HAVING A SFC LOW FORM ON THE SLOW
MOVING FRONT WHICH BRINGS ANOTHER ROUND OF RAIN FOR WEDNESDAY NIGHT
AND THURSDAY...WHILE THE GFS IS FASTER WITH THE FRONT AND
CORRESPONDINGLY FURTHER EAST WITH THE RAIN. EVEN SO...IT CONTINUES
TO BRING THE CHANCE FOR SHOWERS BY THURSDAY AS SHARP UPPER TROUGH
GOES NEGATIVE TILT THEN CUTS OFF.
UPPER LOW THEN PERSISTS OVER THE CENTRAL GREAT LAKES INTO THE
WEEKEND AND 850 MB TEMPS ARE DOWN TO MINUS 2C TO MINUS 4C ACROSS THE
NORTHERN FORECAST AREA. COULD SEE SOME WET SNOW OR GRAUPEL IN ANY
SHOWERS/CONVECTIVE UPDRAFTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 135 PM EDT SUN MAY 11 2014
BEST MOISTURE AND INSTABILITY HAS BEEN DELAYED INTO SW MI.
THEREFORE THE 18Z TAFS REFLECT A SLOWER ARRIVAL OF ANY STORMS TO
AFTER 04Z. UNTIL THEN EXPECT VFR CONDITIONS WITH SOUTH WINDS AROUND
10 KNOTS.
THE STORMS OVERNIGHT SHOULD REMAIN SCATTERED SO HAVE ONLY INCLUDED
VICINITY THUNDER AT THIS POINT. THE MAIN FOCUS TO THE STORMS
SHOULD BE ALONG I-94...BUT THERE COULD ALSO BE A FEW AROUND
I-96...ESPECIALLY AROUND DAYBREAK. MOSTLY VFR CONDITIONS CAN BE
EXPECT OUTSIDE OF AN STORMS THROUGH MID DAY MONDAY.
&&
.MARINE...
ISSUED AT 328 AM EDT SUN MAY 11 2014
WE CONTINUE TO EXPECT THAT WINDS WILL INCREASE OVERNIGHT
TONIGHT AS THE NEXT SYSTEM COMES IN...AND COULD BE EXCEEDING
SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK MONDAY MORNING. THIS IS
NOT A GUARANTEE HOWEVER AS WE WILL HAVE A STABLE SITUATION WHERE
WARMER AIR IS MOVING IN OVER COLDER WATER. THIS POTENTIAL WINDY
PERIOD WOULD LAST INTO TUESDAY MORNING BEFORE CONDITIONS WOULD
IMPROVE A BIT AS A WEAKER GRADIENT MOVES IN WITH THE FRONT.
ANOTHER BURST OF WIND WILL BE POSSIBLE BEHIND THE FRONT TUE EVENING.
&&
.HYDROLOGY...
ISSUED AT 328 AM EDT SUN MAY 11 2014
HYDRO CONCERNS WILL LIKELY RAMP UP BEGINNING SUNDAY AND LASTING INTO
MID WEEK AT LEAST. AN ACTIVE PERIOD IS EXPECTED TO DEVELOP FOR
THE SUNDAY THROUGH TUESDAY TIME FRAME WITH HEAVY RAINS POSSIBLE.
THE BOUNDARY THAT WENT THROUGH THE AREA FRIDAY EVENING WILL COME
BACK NORTH AS A WARM FRONT ON SUNDAY...PULLING GULF MOISTURE WITH
IT. PWAT VALUES RISE TO SLIGHTLY ABOVE 1.50 INCHES...WHICH WOULD
BE 99TH PERCENTILE TYPE OF AMOUNTS.
THE WETTEST PERIOD LOOKS TO COME FROM SUNDAY NIGHT THROUGH
TUESDAY. RAINFALL AMOUNTS OF 1 TO 2 INCHES LOOKS QUITE
POSSIBLE...WITH SOME LOCALLY HEAVIER AMOUNTS LIKELY. SOME RIVERS
UP NORTH ARE ALREADY ABOVE ADVISORY STAGE AND OBVIOUSLY ABOVE
NORMAL. ADDITIONAL RAINFALL WOULD ONLY PUSH STAGES HIGHER. AT THIS
POINT NOT CONSIDERING ANY HYDRO HEADLINES. WE WILL CONTINUE TO
MONITOR.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...OSTUNO
AVIATION...JK
HYDROLOGY...DUKE/NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1048 AM EDT SUN MAY 11 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 328 AM EDT SUN MAY 11 2014
HIGH PRESSURE WILL SLIP EAST AND ALLOW A FRONTAL SYSTEM TO MOVE
BACK INTO THE AREA TONIGHT. AS THIS SYSTEM MOVES BACK IN SHOWERS
AND THUNDERSTORMS WILL BECOME MORE LIKELY THIS EVENING INTO
TUESDAY EVENING. WARMER AIR WILL MOVE INTO THE AREA FOR THE FIRST
COUPLE OF DAYS OF THE NEW WORK WEEK BEFORE COLDER AIR MOVES IN
BEHIND THE SYSTEM FOR LATE IN THE WEEK.
&&
.UPDATE...
ISSUED AT 1047 AM EDT SUN MAY 11 2014
WILL ISSUE A FCST UPDATE TO LOWER/DELAY THE CHANCE OF RAIN TODAY
AND TO BE MORE OPTIMISTIC WITH CLOUD COVER BASED ON CURRENT
SATELLITE/RADAR TRENDS AS WELL AS LATEST HRRR GUIDANCE. WILL ONLY
CARRY A 20 POP AFTER 5 PM SOUTH OF I-96 WHERE LEADING EDGE OF
BETTER MOISTURE/INSTABILITY WILL BE NOSING IN LATER IN THE DAY.
NEW 12Z NAM SHOWS LLJ FOCUSING FARTHER WEST TONIGHT AND AIMED INTO
IOWA/SRN MN/SW WI. MAY HAVE TO CONSIDER LOWERING POPS TONIGHT AS
WELL BUT WILL WAIT ON ADDITIONAL GUIDANCE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 328 AM EDT SUN MAY 11 2014
MAIN FOCUS OF THE SHORT TERM CONTINUES TO BE CONVECTIVE TRENDS AND
SEVERE WEATHER POTENTIAL THROUGH THE PERIOD. THERE ARE NO REAL
CHANGES TO THE FCST.
THE QUIETEST PERIOD OF THE SHORT TERM WILL BE THE FIRST PERIOD
TODAY. THE CWFA REMAINS DRY AS OF 07Z THIS MORNING...HOWEVER WE ARE
EXPECTING AT LEAST A FEW LIGHT SHOWERS TO DEVELOP AND ROLL IN LATER
THIS MORNING AND THIS AFTERNOON. THIS WILL OCCUR AS A LLJ OF 35+
KNOTS FUELING A FEW SHOWERS AN ISOLATED THUNDER NEAR THE QUAD CITIES
WILL TRANSLATE EAST THROUGH 18Z. THIS LLJ WILL BE WEAKENING AND WILL
BE BATTLING A FAIR AMOUNT OF DRY AIR INITIALLY OVER THE AREA.
WE WILL SEE A BETTER POTENTIAL OF STORMS DEVELOP THIS EVENING ACROSS
THE SOUTH...AND EVENTUALLY THE CHCS WILL SPREAD NORTH THROUGH THE
NIGHT TONIGHT. A STALLED OUT FRONT CURRENTLY ACROSS IL/IN/OH WILL
STRENGTHEN THIS EVENING AS BETTER WARMTH AND MOISTURE ADVECTS NORTH
OUT OF THE GULF OF MEXICO. WE WILL SEE ANOTHER LLJ INCREASE TO
AROUND 30-35 KNOTS AND NOSE UP INTO THE HEART OF THE CWFA. THE
STORMS SHOULD START OUT AS MAINLY ELEVATED WITH THE FRONT TO OUR
SOUTH INITIALLY. FCST SOUNDINGS SHOW THAT HAIL LOOKS LIKE THE BEST
THREAT WITH A GOOD DEAL OF CAPE IN THE -10C TO -30C LAYER. DAMAGING
WINDS ARE POSSIBLE...HOWEVER A BIT LIMITED DUE TO THE ELEVATED
NATURE OF THE STORMS.
WE EXPECT THAT WAVES OF STORMS WILL REMAIN POSSIBLE THROUGH MON AND
INTO MON EVENING. THE FRONT IS EXPECTED TO GET HELD UP GENERALLY
AROUND THE I-96 CORRIDOR AS IT WILL WAIT FOR A GOOD PUSH IN THE MID
LEVELS AS THE WRN TROUGH STARTS TO LIFT OUT. A 25-30 KNOT LLJ WILL
GENERALLY REMAIN IN PLACE THROUGH THAT PERIOD WHICH WILL HELP TO
FEED THE FORCING AND MOISTURE/WARMTH INTO THE AREA. IT LOOKS LIKE
ALONG OR JUST NORTH OF THE I-96 CORRIDOR WILL SEE THE HIGHEST RAIN
AMOUNTS. WHAT WILL BE INTERESTING IS THE POTENTIAL OF SOME SFC BASED
INSTABILITY ON MON SOUTH OF THE FRONT. THIS COULD ENHANCE THE THREAT
OF SOME SEVERE WX ALONG WITH DEEP LAYER SHEAR VALUES AT OR ABOVE
30.
WE SHOULD SEE A BREAK IN THE MORE WIDESPREAD SHOWER AND STORM
ACTIVITY THEN FOR THE SECOND HALF OF MON NIGHT. WE FINALLY SEE THE
TROUGH OUT WEST DIG ENOUGH THAT THE RIDGE BUILDS IN OUR
NEIGHBORHOOD. THIS WILL PUSH THE WARM FRONT WELL NORTH OF THE AREA
BY TUE.
SHOWERS AND STORMS BECOME MORE NUMEROUS ON TUE ONCE AGAIN AS THE
COLD FRONT AND WHAT LOOKS LIKE A THERMAL TROUGH DEVELOPS INLAND
AND BEGINS TO PUSH THROUGH THE AREA. WE PREFER THE SLOWER FOREIGN
MODEL SOLUTIONS AS THE FRONT LOOKS TO BE FAIRLY PARALLEL WITH THE
UPPER JET. THIS WOULD BRING THE FRONT THROUGH DURING THE DAY WHEN
SOME DIURNAL INSTABILITY WILL BE POSSIBLE. DEEP LAYER SHEAR WILL
ONCE AGAIN BE SUFFICIENT FOR ORGANIZED STORMS WITH VALUES OVER 30
AND INCREASING THAT DAY. FCST SOUNDINGS DO LOOK QUITE CLOUDY WITH A
LOT OF MOISTURE...WHICH WOULD LIMIT THE SEVERE POTENTIAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 328 AM EDT SUN MAY 11 2014
LOOKS LIKE A PRETTY UNSETTLED PERIOD WITH COLD AND SHOWERY WEATHER
BY THE END OF THE WEEK UNDER AN UPPER LOW. WILL HAVE TO WATCH
CLOSELY FOR ANY CLEARING OUT ON THURSDAY NIGHT OR FRIDAY NIGHT WHICH
WOULD RESULT IN WIDESPREAD FROST/FREEZE CONDITIONS GIVEN HOW COLD IT
WILL BE.
COLD FRONT PUSHES EAST TUESDAY NIGHT. MODEL DIFFERENCES BETWEEN THE
00Z RUNS OF THE GFS AND ECMWF ARE THE SAME AS THEY HAVE BEEN THE
LAST FEW DAYS WITH THE ECMWF HAVING A SFC LOW FORM ON THE SLOW
MOVING FRONT WHICH BRINGS ANOTHER ROUND OF RAIN FOR WEDNESDAY NIGHT
AND THURSDAY...WHILE THE GFS IS FASTER WITH THE FRONT AND
CORRESPONDINGLY FURTHER EAST WITH THE RAIN. EVEN SO...IT CONTINUES
TO BRING THE CHANCE FOR SHOWERS BY THURSDAY AS SHARP UPPER TROUGH
GOES NEGATIVE TILT THEN CUTS OFF.
UPPER LOW THEN PERSISTS OVER THE CENTRAL GREAT LAKES INTO THE
WEEKEND AND 850 MB TEMPS ARE DOWN TO MINUS 2C TO MINUS 4C ACROSS THE
NORTHERN FORECAST AREA. COULD SEE SOME WET SNOW OR GRAUPEL IN ANY
SHOWERS/CONVECTIVE UPDRAFTS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 732 AM EDT SUN MAY 11 2014
VFR CONDITIONS EXPECTED TODAY AND INTO THIS EVENING. SOME
SCATTERED THUNDERSTORMS WILL BE MOVING IN BY EVENING ALTHOUGH
COVERAGE SHOULD BE LOW UNTIL AROUND MIDNIGHT WHEN SOME MVFR
CONDITIONS DEVELOP IN MORE WIDESPREAD SHOWERS AND THUNDERSTORMS.
WINDS WILL BE SOUTHEAST TODAY AROUND 10 KNOTS GOING SOUTHWEST
TONIGHT.
&&
.MARINE...
ISSUED AT 328 AM EDT SUN MAY 11 2014
WE CONTINUE TO EXPECT THAT WINDS WILL INCREASE OVERNIGHT
TONIGHT AS THE NEXT SYSTEM COMES IN...AND COULD BE EXCEEDING
SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK MONDAY MORNING. THIS IS
NOT A GUARANTEE HOWEVER AS WE WILL HAVE A STABLE SITUATION WHERE
WARMER AIR IS MOVING IN OVER COLDER WATER. THIS POTENTIAL WINDY
PERIOD WOULD LAST INTO TUESDAY MORNING BEFORE CONDITIONS WOULD
IMPROVE A BIT AS A WEAKER GRADIENT MOVES IN WITH THE FRONT.
ANOTHER BURST OF WIND WILL BE POSSIBLE BEHIND THE FRONT TUE EVENING.
&&
.HYDROLOGY...
ISSUED AT 328 AM EDT SUN MAY 11 2014
HYDRO CONCERNS WILL LIKELY RAMP UP BEGINNING SUNDAY AND LASTING INTO
MID WEEK AT LEAST. AN ACTIVE PERIOD IS EXPECTED TO DEVELOP FOR
THE SUNDAY THROUGH TUESDAY TIME FRAME WITH HEAVY RAINS POSSIBLE.
THE BOUNDARY THAT WENT THROUGH THE AREA FRIDAY EVENING WILL COME
BACK NORTH AS A WARM FRONT ON SUNDAY...PULLING GULF MOISTURE WITH
IT. PWAT VALUES RISE TO SLIGHTLY ABOVE 1.50 INCHES...WHICH WOULD
BE 99TH PERCENTILE TYPE OF AMOUNTS.
THE WETTEST PERIOD LOOKS TO COME FROM SUNDAY NIGHT THROUGH
TUESDAY. RAINFALL AMOUNTS OF 1 TO 2 INCHES LOOKS QUITE
POSSIBLE...WITH SOME LOCALLY HEAVIER AMOUNTS LIKELY. SOME RIVERS
UP NORTH ARE ALREADY ABOVE ADVISORY STAGE AND OBVIOUSLY ABOVE
NORMAL. ADDITIONAL RAINFALL WOULD ONLY PUSH STAGES HIGHER. AT THIS
POINT NOT CONSIDERING ANY HYDRO HEADLINES. WE WILL CONTINUE TO
MONITOR.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...DUKE/NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
739 AM EDT SUN MAY 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM EDT SUN MAY 11 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE HEADING SE
TOWARD THE SRN ROCKIES...LEADING THE TROF AMPLIFICATION DOWNSTREAM
OF ADVERTISED BUILDING RIDGE JUST OFF THE W COAST. DEEPENING TROF
AND SHORTWAVE WILL BRING THE NEXT ROUND OF WIDESPREAD WET WEATHER TO
THE UPPER GREAT LAKES...BEGINNING AS EARLY AS LATER TONIGHT. AHEAD
OF THE AMPLIFYING WRN TROF...A SHORTWAVE IS LIFTING THRU THE UPPER
MISSISSIPPI VALLEY. WITH LARGER SCALE RIDGE BUILDING OVER THE
MISSISSIPPI VALLEY/WRN LAKES DOWNSTREAM OF THE DEEPENING WRN
TROF...WAVE IS WEAKENING. LATEST RADAR IMAGERY SHOWS ISOLD/SCT
-SHRA ALONG THE MI/WI BORDER AREA. WITH VERY DRY MASS OVER
THE AREA (NOTE THE VERY DRY COLUMN SAMPLED BY 00Z KGRB SOUNDING)...
PCPN HAS BEEN ON THE LIGHT SIDE WITH MUCH OF IT NOT MORE THAN
SPRINKLES.
SOMEWHAT SURPRISED THAT -SHRA/SPRINKLES ARE HOLDING TOGETHER GIVEN
THE ANTECEDANT DRY AIR MASS AND THE SHORTWAVE/FORCING WEAKENING
UNDER DEVELOPING HEIGHT RISES. IN ANY EVENT...ISOLD/SCT
-SHRA/SPRINKLES SHOULD MOVE NE ACROSS ALL BUT THE FAR ERN FCST AREA
DURING THE MORNING. AFTER THE MORNING HRS...EXPECT A DRY AFTN UNDER
CONTINUED HEIGHT RISES AS RIDGE BUILDS THRU THE WRN GREAT LAKES
DOWNSTREAM OF ROCKIES TROF. YESTERDAY...A NUMBER OF MODELS WERE
SUGGESTING SOME AFTN CONVECTION...ESPECIALLY THE NAM. THAT IDEA WAS
DISREGARDED AS MODELS WERE OVERFORECASTING LOW-LEVEL MOISTURE AND
THUS INSTABILITY. WELL...TODAYS 00Z MODELS RUNS ARE ALMOST ALL
ONBOARD WITH A DRY AFTN AS A RESULT OF CORRECTING THE
MOISTURE/INSTABILITY DOWNWARD. CLOUDS WILL THIN SOME IN THE
AFTN...ALLOWING TEMPS TO RISE WELL INTO THE 60S TO AROUND 70F AWAY
FROM LAKE MODERATION.
AS STRONGER SHORTWAVE BEGINS TO EJECT OUT OF DEEPENING UPPER TROF
DRIFTING TOWARD THE WRN PLAINS TONIGHT...SFC LOW PRES WILL BEGIN TO
LIFT NE THRU THE PLAINS. ALTHOUGH THE EVENING MAY BE DRY...
ESPECIALLY OVER THE NE HALF OF THE FCST AREA CLOSER TO DRY LOW-LEVEL
NE TRAJECTORIES OUT OF SFC HIGH PRES IN ONTARIO...MOST OF THE MODELS
SHOW HIGHER MID LEVEL RH AND PCPN ARRIVING FROM THE SW THRU THE
NIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS N. THERE ARE
INDICATIONS OF A SUBTLE SHORTWAVE LIFTING NE INTO THE UPPER
MISSISSIPPI VALLEY LATE TONIGHT...AND THAT WILL FURTHER AID THE
DEVELOPMENT/SPREAD OF SHRA NE INTO UPPER MI DURING THE OVERNIGHT.
NOT MUCH INSTABILITY IS NOTED PER 0-3KM MUCAPE OFF THE NAM/GFS. WITH
A COUPLE HUNDRED J/KG AND SHOWALTER INDEX FALLING JUST BLO 0 OVER
THE FAR SCNTRL LATE TONIGHT IN MOST MODEL GUIDANCE...WILL INCLUDE A
THUNDER MENTION IN THAT AREA LATE TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 454 AM EDT SUN MAY 11 2014
AGREEMENT IS HIGH IN OVERALL LARGER SCALE PATTERN FOR THE UPCOMING
WEEK. FLOW IS HIGHLY AMPLIFIED. INITIALY THIS WEEK TROUGH OVER THE
WESTERN CONUS THIS MORNING SLIDES ACROSS THE CENTRAL CONUS. SFC-H85
LOW PRESSURE BEGINS TO FORM TODAY OVER THE SOUTHERN PLAINS AND THIS
LOW LIFTS TOWARD UPPER MISSISSIPPI RIVER VALLEY BY DAYBREAK ON
MONDAY. SFC WARM FRONT SHOULD STAY SOUTH OF UPR MICHIGAN...MAINLY
OVER SOUTHERN/CENTRAL WI ACROSS CENTRAL LOWER MICHIGAN. EASTERLY
LOW-LEVEL WINDS OFF THE COLD GREAT LAKES TO THE NORTH OF THE FRONT
ALONG WITH SHRA/TSRA FIRING ALONG THE FRONT SHOULD KEEP THE WARM
FRONT FROM MOVING INTO UPR MICHIGAN ON MONDAY. WARM FRONT SOUTH OF
HERE ALONG WITH EASTERLY WINDS SHOULD KEEP TEMPS COOLER ON MONDAY
THAN THIS WEEKEND.
H85 WARM FRONT WILL BE IN THE VICINITY THOUGH AND THERE IS MOISTURE
TRANSPORT AT H85-H7 AIMED INTO THE H85 FRONT ALLOWING PWATS OVER 1.5
INCHES OR WELL OVER 200 PCT OF NORMAL TO PUSH NORTHWARD ACROSS UPPER
GREAT LAKES REGION. SHORTWAVE/PV ANAMOLY EMERGING NORTHEAST OUT OF
THE LARGE WESTERN CONUS TROUGH RESULTS IN AREA OF H85-H5 Q-VECTOR
CONVERGENCE SPREADING OVER UPPER GREAT LAKES ON MONDAY. ADDITIONAL
LIFT WILL BE PROVIDED VIA 250MB JET STREAK LIFTING NNE-SSW AHEAD OF
MAIN TROUGH AND ALSO ANOTHER SLIDING WNW-ESE OVER NORTHERN ONTARIO
TOWARD QUEBEC. AT FIRST GLANCE...A LOT OF THINGS ARE FAVORABLE FOR
MULTIPLE PERIODS OF SHOWERS OVER UPR MICHIGAN ON MONDAY. YET...THE
INSTABILITY BOTH ELEVATED /1-6KM MUCAPE/ AND AT THE SFC /MLCAPE/ IS
NOT AS FAVORABLE...WITH GRADIENT OF BOTH TO SOUTH AND SOUTHWEST OF
UPR MICHIGAN THROUGH THE DAY. MODELS DIFFER ON PLACEMENT OF MAXIMUM
MOISTURE ADVECTION AND THIS WILL HAVE DIRECT BEARING ON WHETHER
WESTERN HALF OF CWA OR EASTERN HALF OF CWA SEES MOST RAIN ON MONDAY.
TOUGH TO TELL AT THIS POINT WHICH IDEA WILL BE CORRECT. CORFIDI
VECTORS...BOTH FORWARD AND BACKWARD PROPAGATING...ARE ORIENTED
GENERALLY FROM WEST TO EAST ALONG AND SOUTH OF UPR MICHIGAN...WHICH
LIKELY WILL KEEP PERIODS OF PERSISTENT/HEAVIEST SHRA/TSRA TO SOUTH
OF THE AREA SINCE THAT IS WHERE PRIME GENESIS REGION FOR SHRA/TSRA
WILL BE ALONG THE SFC WARM FRONT. PERFER THE LOOK OF THE ECMWF/UKMET
WHICH KEEP THE TRACK OF HIGHEST QPF ONLY OVER SCNTRL CWA...WITH
LIGHTER AMOUNTS FARTHER NORTH AWAY FM THE SFC WARM FRONT. EVEN
SO...GOING LIKELY POPS SEEM ON TRACK WITH H85 FRONT IN VICINTY.
KEPT SMALL MENTION OF TSRA MAINLY OVER SOUTH HALF INTO THE EASTERN
CWA ALONG NORTH GRADIENT OF ELEVATED INSTABILITY. SPC DAY2 SEVERE
RISK KEEPS SLIGHT PROBABILITIES FARTHER SOUTH...BUT DOES HIGHLIGHT
SOUTHERN TIER OF CWA FOR A 5 PCT RISK.
NEXT SURGE OF SHRA/TSRA DEVELOP MONDAY NIGHT IN RESPONSE TO
SHARPENING TROUGH ALOFT. SFC LOW HAS TRENDED FARTHER NORTH OVER TIME
WITH SFC LOW LIFTING ACROSS WESTERN LK SUPERIOR BY TUESDAY MORNING.
BEFORE THAT...LARGE SCALE ASCENT DEVELOPS DUE TO THE DEEPENING OF
TROUGH ALOFT AND INCREASINGLY DIFFLUENT FLOW ALOFT. THOUGH SFC WARM
FRONT STAYS MAINLY SOUTH OF UPR MICHIGAN...H85 WARM FRONT WILL
PROVIDE MAIN FOCUS FOR SHRA/TSRA MONDAY NIGHT INTO TUESDAY MORNING
AS ANOTHER SURGE OF H85-H7 MOISTURE ADVECTION INTERSECTS THE
BOUNDARY. GFS SEEMS TOO QUICK IN SLIDING THIS WHOLE SYSTEM TO THE
EAST. ECMWF/UKMET AND GEM-NH ARE SLOWER WHICH MAKES SENSE WITH THE
SHARPER TROUGH ALOFT. GIVEN PWATS STILL OVER 200 PCT OF
NORMAL...MODERATE TO HEAVY RAIN COULD OCCUR. DECENT SIGNAL FROM
PREFERRED MODELS THAT HEAVIEST RAIN IMPACTS MAINLY NORTHERN
CWA...INCLUDING THE KEWEENAW PENINSULA. OBVIOUSLY WITH THE SNOWMELT
AND HIGHER RIVER FLOWS THAT ARE CURRENTLY OCCURRING THIS WOULD NOT BE
A GOOD SITUATION IF IT WORKED OUT THIS WAY. SIMILAR TO FORECAST ON
MONDAY...SINCE THE SFC WARM FRONT IS STILL SOUTH OF THE AREA...SFC
SHRA/TSRA ONGOING ALONG THE FRONT COULD VERY WELL IMPACT THIS ENTIRE
SCENARIO...ESPECIALLY AS STORM MOTIONS ARE FORECAST TO BE FROM SW-
NE...SUGGESTING THAT IF CLUSTER OF STORMS FORM FARTHER SOUTH CLOSER
TO SFC WARM FRONT THEY COULD GLIDE OVER EASTERN CWA AND GENERALLY
BYPASS THE WESTERN CWA. CONDIFENCE IN ANY OF THESE TYPE OF DETAILS
REMAINS LOW ATTM.
AS THE SFC LOW LIFTS NORTH OF LK SUPERIOR BY TUESDAY AFTN...EXPECT
DRYING TO SPREAD IN FROM THE WEST...DIMINISHING THEN SHUTTING OFF
ADDITIONAL PRECIPITATION. THOUGH SKIES WILL NOT COMPLETELY CLEAR OUT
AS A LOT OF H85 MOISTURE REMAINS...EVEN SHALLOW MIXING WITH THE WEST
LOW-LEVEL WINDS SHOULD RESULT IN TEMPS PUSHING INTO THE 60S OVER ALL
BUT THE FAR WEST/NORTHWEST AND EAST CWA.
QUESTION FOR THE REST OF THE WEEK IS NOT IF IT WILL BE COOL AND
UNSETTLED BUT TO WHAT DEGREE. ECMWF IS BACK TO SHOWING A VERY DEEP
TROUGH ALOFT THURSDAY INTO FRIDAY...EVEN TO THE POINT OF BECOMING
CLOSED OFF AROUND THURSDAY. PREVIOUS RUNS OF ECMWF HAD BACKED AWAY
FM STRONGER WAVE WRAPPING AROUND THE EDGE OF THE TROUGH LATE THIS
WEEK BUT NOW ITS BACK. GIVEN H85 TEMPS -2C TO -4C FALLING TO BLO -6C
AS THIS WAVE LIFTS OVER THE REGION...CERTAINLY POSSIBLE THAT SOME
SNOW COULD OCCUR THURSDAY INTO FRIDAY FOR ALMOSTL ANYWHERE IN THE
CWA. CONSENSUS OF THAT WRAPPED UP ECMWF SOLUTION ALONG WITH OTHER
AVAILABLE MEDIUM RANGE MODELS RESULTED IN LOW CHANCES ATTM...WITH
MOST MENTION OF SNOW ONLY OCCURRING LATER AT NIGHT INTO THE MORNING
BEFORE BLYR WARMS ENOUGH FOR JUST RAIN. SYSTEM WILL BE SOMETHING TO
KEEP EYE ON AS WE GET LATER INTO THE WEEK. AT THE LEAST EVEN IF WE
GET BY WITHOUT SEEING ANY SNOW...TEMPS WILL FALL TO WELL BELOW
NORMAL VALUES AGAIN. HIGHS MID-LATE WEEK LIKELY WILL STAY IN THE 40S
OVER MUCH OF NORTHERN UPR MICHIGAN CLOSER TO LK SUPERIOR AND ONLY IN
THE 50S OVER SOUTHERN CWA. NIGHTTIME LOWS WILL BE AROUND FREEZING
FOR MUCH OF THE CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 738 AM EDT SUN MAY 11 2014
LINGERING DRY AIR AT THE LOW LEVELS WILL ENSURE VFR CONDITIONS
CONTINUE AT KIWD/KCMX/KSAW INTO THE EVENING HRS EVEN THOUGH A FEW
-SHRA/SPRINKLES WILL MOVE ACROSS THE AREA THIS MORNING. TONIGHT...
NORTHWARD ADVANCING LOW PRESSURE AND WARM FRONT WILL SPREAD SHRA
TOWARD THE UPPER LAKES. THERE IS QUITE A BIT OF UNCERTAINTY IN HOW
FAST PCPN WILL DEVELOP. FOR NOW...OPTED TO HOLD OFF ANY PCPN MENTION
UNTIL THE OVERNIGHT. KIWD HAS THE BEST CHC OF CONDITIONS FALLING TO
MVFR LATE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT SUN MAY 11 2014
WINDS LESS THAN 20 KTS THROUGH THIS EVENING. WINDS BEGIN TO INCREASE
OVER WESTERN PORTIONS OF LK SUPERIOR LATE TONIGHT AND MORE SO ON
MONDAY AS LOW PRESSURE APPROACHES FROM THE SOUTHWEST. FREQUENT GALE
GUSTS APPEAR LIKELY OVER FAR WEST...SO HAVE ISSUED A GALE WATCH.
WINDS OVER THE REST OF THE LAKE WILL STAY AT OR BLO 30 KTS. WINDS
DIMINISH LATER MONDAY NIGHT AND THEN SWITCH TO THE WEST TO 20-25 KTS
ON TUESDAY. LOW SLOWLY SLIDES TO THE NORTHEAST OF LK SUPERIOR REST
OF THE WEEK...RESULTING IN NORTHWEST WINDS MAINLY STAYING BLO 20 KTS.
&&
.HYDROLOGY...
ISSUED AT 454 AM EDT SUN MAY 11 2014
HIGHS MOSTLY IN THE 60S TODAY WILL RESULT IN ADDITIONAL SNOWMELT
OVER HIGHER TERRAIN OF NORTHERN UPR MICHIGAN. MINIMAL RAIN AMOUNTS
ARE EXPECTED THROUGH MUCH OF TONIGHT...BUT THEN RAIN CHANCES INCREASE
MONDAY/MONDAY NIGHT AND INTO TUESDAY MORNING. THERE IS A POTENTIAL
FOR MODERATE TO HEAVY RAIN OVER THE AREAS THAT ARE STILL MELTING
SNOW...SO THE RECENT HIGHER RIVER LEVELS WILL CONTINUE THROUGH MUCH
OF THE UPCOMING WEEK. THE FLOOD WARNING CONTINUES FOR THE STURGEON
RIVER NEAR CHASSELL...WHILE ADVISORIES ARE IN PLACE FOR THE STURGEON
RIVER NEAR ALSTON...AND THE MICHIGAMME RIVER NEAR WITCH LAKE AND
ALSO NEAR REPUBLIC. IF HEAVIER RAINS MATERIALIZE EARLY THIS WEEK...
ADDITIONAL ADVISORIES AND WARNINGS MAY BE NEEDED. THOSE LIVING NEAR
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST
RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
456 AM EDT SUN MAY 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM EDT SUN MAY 11 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE HEADING SE
TOWARD THE SRN ROCKIES...LEADING THE TROF AMPLIFICATION DOWNSTREAM
OF ADVERTISED BUILDING RIDGE JUST OFF THE W COAST. DEEPENING TROF
AND SHORTWAVE WILL BRING THE NEXT ROUND OF WIDESPREAD WET WEATHER TO
THE UPPER GREAT LAKES...BEGINNING AS EARLY AS LATER TONIGHT. AHEAD
OF THE AMPLIFYING WRN TROF...A SHORTWAVE IS LIFTING THRU THE UPPER
MISSISSIPPI VALLEY. WITH LARGER SCALE RIDGE BUILDING OVER THE
MISSISSIPPI VALLEY/WRN LAKES DOWNSTREAM OF THE DEEPENING WRN
TROF...WAVE IS WEAKENING. LATEST RADAR IMAGERY SHOWS ISOLD/SCT
-SHRA ALONG THE MI/WI BORDER AREA. WITH VERY DRY MASS OVER
THE AREA (NOTE THE VERY DRY COLUMN SAMPLED BY 00Z KGRB SOUNDING)...
PCPN HAS BEEN ON THE LIGHT SIDE WITH MUCH OF IT NOT MORE THAN
SPRINKLES.
SOMEWHAT SURPRISED THAT -SHRA/SPRINKLES ARE HOLDING TOGETHER GIVEN
THE ANTECEDANT DRY AIR MASS AND THE SHORTWAVE/FORCING WEAKENING
UNDER DEVELOPING HEIGHT RISES. IN ANY EVENT...ISOLD/SCT
-SHRA/SPRINKLES SHOULD MOVE NE ACROSS ALL BUT THE FAR ERN FCST AREA
DURING THE MORNING. AFTER THE MORNING HRS...EXPECT A DRY AFTN UNDER
CONTINUED HEIGHT RISES AS RIDGE BUILDS THRU THE WRN GREAT LAKES
DOWNSTREAM OF ROCKIES TROF. YESTERDAY...A NUMBER OF MODELS WERE
SUGGESTING SOME AFTN CONVECTION...ESPECIALLY THE NAM. THAT IDEA WAS
DISREGARDED AS MODELS WERE OVERFORECASTING LOW-LEVEL MOISTURE AND
THUS INSTABILITY. WELL...TODAYS 00Z MODELS RUNS ARE ALMOST ALL
ONBOARD WITH A DRY AFTN AS A RESULT OF CORRECTING THE
MOISTURE/INSTABILITY DOWNWARD. CLOUDS WILL THIN SOME IN THE
AFTN...ALLOWING TEMPS TO RISE WELL INTO THE 60S TO AROUND 70F AWAY
FROM LAKE MODERATION.
AS STRONGER SHORTWAVE BEGINS TO EJECT OUT OF DEEPENING UPPER TROF
DRIFTING TOWARD THE WRN PLAINS TONIGHT...SFC LOW PRES WILL BEGIN TO
LIFT NE THRU THE PLAINS. ALTHOUGH THE EVENING MAY BE DRY...
ESPECIALLY OVER THE NE HALF OF THE FCST AREA CLOSER TO DRY LOW-LEVEL
NE TRAJECTORIES OUT OF SFC HIGH PRES IN ONTARIO...MOST OF THE MODELS
SHOW HIGHER MID LEVEL RH AND PCPN ARRIVING FROM THE SW THRU THE
NIGHT AS WAA/ISENTROPIC ASCENT REGIME SPREADS N. THERE ARE
INDICATIONS OF A SUBTLE SHORTWAVE LIFTING NE INTO THE UPPER
MISSISSIPPI VALLEY LATE TONIGHT...AND THAT WILL FURTHER AID THE
DEVELOPMENT/SPREAD OF SHRA NE INTO UPPER MI DURING THE OVERNIGHT.
NOT MUCH INSTABILITY IS NOTED PER 0-3KM MUCAPE OFF THE NAM/GFS. WITH
A COUPLE HUNDRED J/KG AND SHOWALTER INDEX FALLING JUST BLO 0 OVER
THE FAR SCNTRL LATE TONIGHT IN MOST MODEL GUIDANCE...WILL INCLUDE A
THUNDER MENTION IN THAT AREA LATE TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 454 AM EDT SUN MAY 11 2014
AGREEMENT IS HIGH IN OVERALL LARGER SCALE PATTERN FOR THE UPCOMING
WEEK. FLOW IS HIGHLY AMPLIFIED. INITIALY THIS WEEK TROUGH OVER THE
WESTERN CONUS THIS MORNING SLIDES ACROSS THE CENTRAL CONUS. SFC-H85
LOW PRESSURE BEGINS TO FORM TODAY OVER THE SOUTHERN PLAINS AND THIS
LOW LIFTS TOWARD UPPER MISSISSIPPI RIVER VALLEY BY DAYBREAK ON
MONDAY. SFC WARM FRONT SHOULD STAY SOUTH OF UPR MICHIGAN...MAINLY
OVER SOUTHERN/CENTRAL WI ACROSS CENTRAL LOWER MICHIGAN. EASTERLY
LOW-LEVEL WINDS OFF THE COLD GREAT LAKES TO THE NORTH OF THE FRONT
ALONG WITH SHRA/TSRA FIRING ALONG THE FRONT SHOULD KEEP THE WARM
FRONT FROM MOVING INTO UPR MICHIGAN ON MONDAY. WARM FRONT SOUTH OF
HERE ALONG WITH EASTERLY WINDS SHOULD KEEP TEMPS COOLER ON MONDAY
THAN THIS WEEKEND.
H85 WARM FRONT WILL BE IN THE VICINITY THOUGH AND THERE IS MOISTURE
TRANSPORT AT H85-H7 AIMED INTO THE H85 FRONT ALLOWING PWATS OVER 1.5
INCHES OR WELL OVER 200 PCT OF NORMAL TO PUSH NORTHWARD ACROSS UPPER
GREAT LAKES REGION. SHORTWAVE/PV ANAMOLY EMERGING NORTHEAST OUT OF
THE LARGE WESTERN CONUS TROUGH RESULTS IN AREA OF H85-H5 Q-VECTOR
CONVERGENCE SPREADING OVER UPPER GREAT LAKES ON MONDAY. ADDITIONAL
LIFT WILL BE PROVIDED VIA 250MB JET STREAK LIFTING NNE-SSW AHEAD OF
MAIN TROUGH AND ALSO ANOTHER SLIDING WNW-ESE OVER NORTHERN ONTARIO
TOWARD QUEBEC. AT FIRST GLANCE...A LOT OF THINGS ARE FAVORABLE FOR
MULTIPLE PERIODS OF SHOWERS OVER UPR MICHIGAN ON MONDAY. YET...THE
INSTABILITY BOTH ELEVATED /1-6KM MUCAPE/ AND AT THE SFC /MLCAPE/ IS
NOT AS FAVORABLE...WITH GRADIENT OF BOTH TO SOUTH AND SOUTHWEST OF
UPR MICHIGAN THROUGH THE DAY. MODELS DIFFER ON PLACEMENT OF MAXIMUM
MOISTURE ADVECTION AND THIS WILL HAVE DIRECT BEARING ON WHETHER
WESTERN HALF OF CWA OR EASTERN HALF OF CWA SEES MOST RAIN ON MONDAY.
TOUGH TO TELL AT THIS POINT WHICH IDEA WILL BE CORRECT. CORFIDI
VECTORS...BOTH FORWARD AND BACKWARD PROPAGATING...ARE ORIENTED
GENERALLY FROM WEST TO EAST ALONG AND SOUTH OF UPR MICHIGAN...WHICH
LIKELY WILL KEEP PERIODS OF PERSISTENT/HEAVIEST SHRA/TSRA TO SOUTH
OF THE AREA SINCE THAT IS WHERE PRIME GENESIS REGION FOR SHRA/TSRA
WILL BE ALONG THE SFC WARM FRONT. PERFER THE LOOK OF THE ECMWF/UKMET
WHICH KEEP THE TRACK OF HIGHEST QPF ONLY OVER SCNTRL CWA...WITH
LIGHTER AMOUNTS FARTHER NORTH AWAY FM THE SFC WARM FRONT. EVEN
SO...GOING LIKELY POPS SEEM ON TRACK WITH H85 FRONT IN VICINTY.
KEPT SMALL MENTION OF TSRA MAINLY OVER SOUTH HALF INTO THE EASTERN
CWA ALONG NORTH GRADIENT OF ELEVATED INSTABILITY. SPC DAY2 SEVERE
RISK KEEPS SLIGHT PROBABILITIES FARTHER SOUTH...BUT DOES HIGHLIGHT
SOUTHERN TIER OF CWA FOR A 5 PCT RISK.
NEXT SURGE OF SHRA/TSRA DEVELOP MONDAY NIGHT IN RESPONSE TO
SHARPENING TROUGH ALOFT. SFC LOW HAS TRENDED FARTHER NORTH OVER TIME
WITH SFC LOW LIFTING ACROSS WESTERN LK SUPERIOR BY TUESDAY MORNING.
BEFORE THAT...LARGE SCALE ASCENT DEVELOPS DUE TO THE DEEPENING OF
TROUGH ALOFT AND INCREASINGLY DIFFLUENT FLOW ALOFT. THOUGH SFC WARM
FRONT STAYS MAINLY SOUTH OF UPR MICHIGAN...H85 WARM FRONT WILL
PROVIDE MAIN FOCUS FOR SHRA/TSRA MONDAY NIGHT INTO TUESDAY MORNING
AS ANOTHER SURGE OF H85-H7 MOISTURE ADVECTION INTERSECTS THE
BOUNDARY. GFS SEEMS TOO QUICK IN SLIDING THIS WHOLE SYSTEM TO THE
EAST. ECMWF/UKMET AND GEM-NH ARE SLOWER WHICH MAKES SENSE WITH THE
SHARPER TROUGH ALOFT. GIVEN PWATS STILL OVER 200 PCT OF
NORMAL...MODERATE TO HEAVY RAIN COULD OCCUR. DECENT SIGNAL FROM
PREFERRED MODELS THAT HEAVIEST RAIN IMPACTS MAINLY NORTHERN
CWA...INCLUDING THE KEWEENAW PENINSULA. OBVIOUSLY WITH THE SNOWMELT
AND HIGHER RIVER FLOWS THAT ARE CURRENTLY OCCURRING THIS WOULD NOT BE
A GOOD SITUATION IF IT WORKED OUT THIS WAY. SIMILAR TO FORECAST ON
MONDAY...SINCE THE SFC WARM FRONT IS STILL SOUTH OF THE AREA...SFC
SHRA/TSRA ONGOING ALONG THE FRONT COULD VERY WELL IMPACT THIS ENTIRE
SCENARIO...ESPECIALLY AS STORM MOTIONS ARE FORECAST TO BE FROM SW-
NE...SUGGESTING THAT IF CLUSTER OF STORMS FORM FARTHER SOUTH CLOSER
TO SFC WARM FRONT THEY COULD GLIDE OVER EASTERN CWA AND GENERALLY
BYPASS THE WESTERN CWA. CONDIFENCE IN ANY OF THESE TYPE OF DETAILS
REMAINS LOW ATTM.
AS THE SFC LOW LIFTS NORTH OF LK SUPERIOR BY TUESDAY AFTN...EXPECT
DRYING TO SPREAD IN FROM THE WEST...DIMINISHING THEN SHUTTING OFF
ADDITIONAL PRECIPITATION. THOUGH SKIES WILL NOT COMPLETELY CLEAR OUT
AS A LOT OF H85 MOISTURE REMAINS...EVEN SHALLOW MIXING WITH THE WEST
LOW-LEVEL WINDS SHOULD RESULT IN TEMPS PUSHING INTO THE 60S OVER ALL
BUT THE FAR WEST/NORTHWEST AND EAST CWA.
QUESTION FOR THE REST OF THE WEEK IS NOT IF IT WILL BE COOL AND
UNSETTLED BUT TO WHAT DEGREE. ECMWF IS BACK TO SHOWING A VERY DEEP
TROUGH ALOFT THURSDAY INTO FRIDAY...EVEN TO THE POINT OF BECOMING
CLOSED OFF AROUND THURSDAY. PREVIOUS RUNS OF ECMWF HAD BACKED AWAY
FM STRONGER WAVE WRAPPING AROUND THE EDGE OF THE TROUGH LATE THIS
WEEK BUT NOW ITS BACK. GIVEN H85 TEMPS -2C TO -4C FALLING TO BLO -6C
AS THIS WAVE LIFTS OVER THE REGION...CERTAINLY POSSIBLE THAT SOME
SNOW COULD OCCUR THURSDAY INTO FRIDAY FOR ALMOSTL ANYWHERE IN THE
CWA. CONSENSUS OF THAT WRAPPED UP ECMWF SOLUTION ALONG WITH OTHER
AVAILABLE MEDIUM RANGE MODELS RESULTED IN LOW CHANCES ATTM...WITH
MOST MENTION OF SNOW ONLY OCCURRING LATER AT NIGHT INTO THE MORNING
BEFORE BLYR WARMS ENOUGH FOR JUST RAIN. SYSTEM WILL BE SOMETHING TO
KEEP EYE ON AS WE GET LATER INTO THE WEEK. AT THE LEAST EVEN IF WE
GET BY WITHOUT SEEING ANY SNOW...TEMPS WILL FALL TO WELL BELOW
NORMAL VALUES AGAIN. HIGHS MID-LATE WEEK LIKELY WILL STAY IN THE 40S
OVER MUCH OF NORTHERN UPR MICHIGAN CLOSER TO LK SUPERIOR AND ONLY IN
THE 50S OVER SOUTHERN CWA. NIGHTTIME LOWS WILL BE AROUND FREEZING
FOR MUCH OF THE CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 139 AM EDT SUN MAY 11 2014
HIGH PRES WILL MOVE SHIFT AWAY FROM THE AREA AS A WARM FRONT
DEVELOPS OVER IOWA AND NRN IL TODAY. EXPECT AN INCREASE IN MID AND
HIGH CLOUDS OVER UPPER MI ALONG WITH SOME LIGHT SHOWERS OR SPRINKLES
AROUND IWD. HOWEVER...WITH THE VERY DRY LOW LEVEL AIRMASS IN
PLACE...EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE FCST PERIOD EVEN
WITH ANY LIGHT PCPN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT SUN MAY 11 2014
WINDS LESS THAN 20 KTS THROUGH THIS EVENING. WINDS BEGIN TO INCREASE
OVER WESTERN PORTIONS OF LK SUPERIOR LATE TONIGHT AND MORE SO ON
MONDAY AS LOW PRESSURE APPROACHES FROM THE SOUTHWEST. FREQUENT GALE
GUSTS APPEAR LIKELY OVER FAR WEST...SO HAVE ISSUED A GALE WATCH.
WINDS OVER THE REST OF THE LAKE WILL STAY AT OR BLO 30 KTS. WINDS
DIMINISH LATER MONDAY NIGHT AND THEN SWITCH TO THE WEST TO 20-25 KTS
ON TUESDAY. LOW SLOWLY SLIDES TO THE NORTHEAST OF LK SUPERIOR REST
OF THE WEEK...RESULTING IN NORTHWEST WINDS MAINLY STAYING BLO 20 KTS.
&&
.HYDROLOGY...
ISSUED AT 454 AM EDT SUN MAY 11 2014
HIGHS MOSTLY IN THE 60S TODAY WILL RESULT IN ADDITIONAL SNOWMELT
OVER HIGHER TERRAIN OF NORTHERN UPR MICHIGAN. MINIMAL RAIN AMOUNTS
ARE EXPECTED THROUGH MUCH OF TONIGHT...BUT THEN RAIN CHANCES INCREASE
MONDAY/MONDAY NIGHT AND INTO TUESDAY MORNING. THERE IS A POTENTIAL
FOR MODERATE TO HEAVY RAIN OVER THE AREAS THAT ARE STILL MELTING
SNOW...SO THE RECENT HIGHER RIVER LEVELS WILL CONTINUE THROUGH MUCH
OF THE UPCOMING WEEK. THE FLOOD WARNING CONTINUES FOR THE STURGEON
RIVER NEAR CHASSELL...WHILE ADVISORIES ARE IN PLACE FOR THE STURGEON
RIVER NEAR ALSTON...AND THE MICHIGAMME RIVER NEAR WITCH LAKE AND
ALSO NEAR REPUBLIC. IF HEAVIER RAINS MATERIALIZE EARLY THIS WEEK...
ADDITIONAL ADVISORIES AND WARNINGS MAY BE NEEDED. THOSE LIVING NEAR
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST
RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
354 PM CDT SUN MAY 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 355 PM CDT SUN MAY 11 2014
EARLY AFTERNOON WATER VAPOR IMAGERY TOGETHER WITH RAP 500MB HEIGHTS
AND WINDS IDENTIFIED A VIGOROUS SHORTWAVE ROTATING OVER THE
4-CORNERS REGION...WITH AN MCS ONGOING IN EASTERN IA. VISIBLE
SATELLITE SHOWED CLEARING BEHIND THIS MCS...AND THE SURFACE OBS HAVE
ALREADY REFLECTED THE BOUNDARY LAYER DESTABILIZATION AS TEMPERATURES
HAVE INCREASED 5DEG/HR BUT KEPT THE EASTERLY COMPONENT IN THE WIND
FIELD.
THIS WIND SHIFT MARKED THE STOUT FRONTAL BOUNDARY WHICH WILL
BE THE FOCUS FOR TORNADOES LATER THIS AFTERNOON ACROSS EASTERN NE
AND WESTERN IA. TEMPERATURES WERE IN THE MID 80S SOUTH OF THIS WARM
FRONT WITH SOUTHERLY WINDS...WHILE NORTH OF THE WARM FRONT
TEMPERATURES WERE IN THE LOW TO MID 70S WITH DEWPOINTS IN THE MID
60S. THE MLCAPE GRADIENT MIRRORED THE POSITION OF THE EAST/WEST
ORIENTED WARM FRONT...BUT INSTABILITY WAS BUILDING WELL NORTH OF THE
FRONT AS EVIDENT BY THE 3HR SBCAPE CHANGE ON THE SPC MESOANALYSIS
PAGE. THE FINAL POSITION OF THE WARM FRONT WILL DICTATE WHERE THE
SURFACE BASED STORMS ARE...AND THUS THE BEST THREAT FOR TORNADOES.
AT THIS TIME IT APPEARS THAT THE THREAT WILL REMAIN WELL SOUTH OF
THE CWA.
HOWEVER...THE LAST FEW RUNS OF THE HRRR AND HOPWRF INDICATE THAT A
FEW ELEVATED STORMS ARE EXPECTED AFTER 00Z ACROSS THE SOUTHERN PART
OF THE FORECAST AREA. THESE STORMS WILL HAVE 1000-1500J/KG OF MUCAPE
TO WORK WITH DEEP SHEAR FAVORABLE FOR ORGANIZED CONVECTION. A FEW
STORMS WILL HAVE THE POTENTIAL FOR PRODUCE SEVERE HAIL...MAINLY
ALONG THE I-90 CORRIDOR. HEAVY RAIN IS ALSO A THREAT...PERHAPS
MORESO THAN THE SEVERE WEATHER. AT THIS TIME...IT APPEARS THAT THE
HEAVIEST RAINFALL WILL FALL JUST SOUTH AND EAST OF THE FORECAST AREA
ALONG A LINE FROM OMAHA TO LA CROSSE WI. IT IS WITHIN THIS LINE THAT
A HP SUPERCELLS ARE EXPECTED WHICH WILL BE CAPABLE OF PRODUCING
2-3IN/HR RAINFALL RATES AND FLASH FLOODING GIVEN THE RAINFALL THAT
OCCURRED EARLIER THIS MORNING. IN OUR CWA...WE DID NOT HAVE
THE MORNING RAINFALL...AND SUPERCELLS APPEAR LESS LIKELY...SO
ALTHOUGH WE MAY GET A QUICK 1-2 INCHES OF RAIN WITH A FEW OF THE
HEAVIER CELLS...THIS IS ABOVE FLASH FLOOD GUIDANCE. THEREFORE HAVE
OPTED TO HOLD OFF ON A FLOOD WATCH FOR NOW. TO TIE BACK INTO THE
HIRES MODELS...THE PROGRESSIVE NATURE OF THE EASTWARD MOVING STORMS
ALSO SUPPORTS NOT ISSUING A FLOOD WATCH.
THERE WILL BE A LULL IN THE PRECIP ACROSS CENTRAL MN AS THE SURFACE
LOW TRACKS NORTHEASTWARD OVERNIGHT. MEANWHILE LIGHT RAIN WILL
CONTINUE ACROSS THE WESTERN CWA IN THE DEFORMATION AREA OF THE UPPER
LEVEL WAVE. FORECAST MODELS SHOW THE POTENTIAL FOR SOME CONVECTION
REDEVELOPING IN THE WARM SECTOR OF THE SURFACE LOW ACROSS EASTERN MN
AND WESTERN WI...SO TRIED TO REFLECT THAT IN THE AFTERNOON POP
GRIDS. THESE STORMS DO HAVE THE POTENTIAL TO BE SEVERE.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 355 PM CDT SUN MAY 11 2014
NOT MUCH IN THE WAY OF CHANGE TO THE EXTENDED PORTION OF THE
FORECAST...WITH THE UPCOMING WEEK BEING MARKED BY COOL TEMPERATURES
AND PERIODIC SCATTERED LIGHT SHOWERS AS A DEEPLY AMPLIFIED
LONGWAVE TROUGH PIVOTS ACROSS THE UPPER MIDWEST AND GREAT LAKES
REGIONS.
THE BEGINNING OF THE LONG TERM PERIOD /MONDAY NIGHT/ WILL FEATURE
RAIN SHOWERS WINDING DOWN AS THE LOW LIFTS TO LAKE SUPERIOR.
ADDITIONAL RAINFALL AMOUNTS SHOULD BE AROUND A COUPLE TENTHS OF AN
INCH OR LESS.
TUESDAY THROUGH FRIDAY BRINGS CYCLONIC FLOW WITH COOLER THAN
NORMAL TEMPERATURES AND THE POTENTIAL FOR OCCASIONAL SCATTERED
SHOWERS AS THE TROUGH BLANKETS THE REGION. HIGHS WILL BE IN THE
50S AND LOWS WILL DIP INTO THE LOWER 30S AND 40S. THE POTENTIAL
FOR FROST LOOKS TO BE TUESDAY THROUGH THURSDAY NIGHTS.
TEMPERATURES MODERATE NEXT WEEKEND AS WESTERN UPPER RIDGING BUILDS
INTO THE CENTRAL CONUS. HIGHS IN THE 60S LOOK LIKE A GOOD BET FOR
NEXT WEEKEND...ALTHOUGH A FEW SHOWERS MAY BE LURKING ON SUNDAY IF
THE ECMWF SOLUTION VERIFIES /WHICH INDICATES A TROUGH WILL BUST
IN FROM THE PACIFIC NORTHWEST AND BREAK DOWN THE RIDGE/.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 116 PM CDT SUN MAY 11 2014
MAIN ISSUE THE REST OF THIS AFTERNOON INTO EARLY EVENING WILL BE
SHOWERS TRYING TO MOVE FROM SD INTO MN. AIR IS QUITE DRY IN THE
LOWER AND MID LEVELS AND LATEST MODELS HAVE CAUGHT ON THIS WITH A
DELAY IN PRECIP. THUS HAVE INDICATED SUCH WITH THE TAFS. ELEVATED
INSTABILITY DOES NOT REALLY BECOME SIGNIFICANT UNTIL AROUND 02Z IN
FAR SOUTHERN MN...THEN CENTRAL MN AND WEST CENTRAL WISCONSIN UNTIL
06Z OR SO. THUS HAVE ALSO DELAYED MENTION OF THUNDER UNTIL MAINLY
THE LATE NIGHT HOURS. MOISTURE TRANSPORT AND LOW LEVEL JET LOOK
DECENT FOR SOUTH CENTRAL MN INTO WISCONSIN...WHERE RAIN SHOULD BE
HEAVIEST...WITH MORE OF A SCATTERED PRECIP PATTERN FARTHER TO THE
NW. OTHERWISE... MVFR CEILINGS GRADUALLY DEVELOP THIS EVENING...
AND ESPECIALLY LATE TONIGHT IN THE WAKE OF THE SHOWERS AND STORMS.
LOOKS LIKE IFR CEILINGS WILL BE WIDESPREAD MONDAY MORNING BEFORE
LIFTING TO MVFR MIDDAY.
KMSP...LIGHT WINDS HAVE BEEN FLOPPING AROUND DURING
MIDDAY...INCLUDING SSE NOW...BUT SHOULD SETTLE TO THE EAST FOR
THE MOST PART. A FEW SHOWERS MOVING IN THIS EVENING...BUT MAIN
THREAT FOR HEAVIER SHOWERS AND STORMS WILL BE LATE TONIGHT WHEN
EXCELLENT LOW LEVEL JET AND MOISTURE TRANSPORT TAKE AIM AT THE
AREA. THERE IS SOME CHANCE THE HEAVY RAIN WILL BYPASS KMSP TO THE
SOUTHEAST...BUT IT DOES LOOK LIKE MSP WILL GET SOME HEAVY RAIN AT
TIMES. AFTER THAT...SURFACE LOW LOOKS TO TRACK VERY CLOSE TO KMSP
TOMORROW MIDDAY...MEANING THAT WIND DIRECTION WILL BE QUITE
VARIABLE BUT SPEEDS WILL BE LIGHT. THIS ALSO MEANS CONFIDENCE IS
HIGH THAT MVFR CEILINGS WILL DEVELOP IN THE WAKE OF THE
PRECIP...WITH A VERY GOOD CHANCE FOR IFR.
/OUTLOOK FOR KMSP/
TUE...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 15-20 KTS.
WED...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS W-NW 5-15 KTS.
THU...MVFR POSSIBLE. SLGT CHC -SHRA. WINDS NW 5-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 355 PM CDT SUN MAY 11 2014
AT THIS TIME RIVER FLOODING APPEARS TO BE THE PRIMARY CONCERN
MAINLY IN WESTERN WI AND THE MAINSTEM OF THE MISSISSIPPI RIVER.
ANOTHER ROUND OF 1 TO 2 INCHES OF BASIN-WIDE RAINFALL IS EXPECTED
OVER THE NEXT 24 HRS. AT THIS TIME...THE THREAT FOR THE HEAVIEST
RAIN AND FLASH FLOODING APPEARS TO BE ACROSS IOWA...SO NOT
ANTICIPATING ANY FLASH FLOODING IN MN OR WI. IF IT WERE TO
HAPPEN...IT WOULD BE IN FAR SOUTHERN MN. LASTLY, IF THE FORECAST
RAINFALL AMOUNTS TREND HIGHER THAN CURRENTLY EXPECTED...THE
FLOODING POTENTIAL WILL INCREASE AS WELL.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...LS
AVIATION...TDK
HYDROLOGY..JRB
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1000 AM CDT SUN MAY 11 2014
.UPDATED...LATEST SATELLITE AND UPPER ANALYSIS SHOWED AN UPPER TROUGH
DIGGING OVER THE ROCKIES...WHICH WAS BRINGING SOME RIDGING OVER THE
REGION. THE SUBTROPICAL JET MAX OVER THE SOUTHERN PLAINS WILL AID IN UPPER
DIVERGENCE FOR TODAY. THIS COMBINED WITH GOOD SOUTHERLY FLOW COMING
OFF THE GULF TO GET SOME CONVECTION GOING THROUGH EARLY THIS
EVENING. AREA RADARS WERE PICKING UP SOME ISOLATED CONVECTION OFF THE
LOUISIANA COAST. THE BEST MOISTURE TRANSPORT WAS NOTED OVER THE
DELTA REGION. AREA SOUNDINGS HAD DECENT SOUTHERLY FLOW UP TO AROUND
600 MB WITH PWATS AROUND 1.7 INCHES. WILL LOOK FOR SOME LOCALLY
HEAVY DOWNPOURS. WE ARE MORE UNSTABLE THIS MORNING WITH CAPES AROUND
3000 AND LI -6. VISIBLE IMAGERY SHOWED SOME DECENT CU FIELDS THIS
MORNING. THE LATEST HRR SHOWS ISOLATED TO SCATTERED CONVECTION
BREAKING OUT EARLIER TODAY. SURFACE ANALYSIS SHOWS DEWPOINTS IN THE
LOWER 70S. SO WE SHOULD BE ABLE TO START EARLIER TODAY WITH THE
DIURNAL CONVECTION. WITH THIS IN MIND HAVE UPPED THE POPS IN THE
EAST SLIGHTLY WITH BETTER INSTABILITY. CURRENT HIGHS IN THE
80S LOOKS TO BE ON TRACK/17/
&&
.AVIATION...CEILINGS HAVE JUST ABOUT ALL RISEN TO MVFR WHILE FOG HAS
JUST ABOUT BURNED OFF AS WELL AS MIXING CONTINUES THIS MORNING. VFR
CEILINGS SHOULD BE THE RULE THIS AFTERNOON WITH SCATTERED SHOWERS
AND THUNDERSTORMS RESULTING IN NO MORE THAN A VICINITY AFFECT OVER
THE MAJORITY OF THE AERODROME. CONVECTION SHOULD DIMINISH BY 00Z
WITH IFR CEILINGS/MVFR VISIBILITIES RETURNING AFTER 06Z./26/
&&
./PREVIOUS DISCUSSION...444 AM CDT SUN MAY 11 2014
.TODAY THROUGH MONDAY NIGHT...
THE ARKLAMISS REGION WILL REMAIN IN A WARM/HUMID AND MAINLY DIURNAL
CONVECTIVE REGIME WITH PRONOUNCED SOUTHERLY LOW LEVEL FLOW. LARGER
SCALE FEATURES AIDING IN DEVELOPMENT OF CONVECTIVE PRECIPITATION ARE
SUBTLE...WITH THE EXIT REGION OF THE SUBTROPICAL JET HELPING TO
ENHANCE UPPER LEVEL DIVERGENCE AND PROVIDE SOME SUPPORT.
EXPECT DAYTIME HEATING TO BE A PRIMARY KEY IN SHOWER/TSTM DEVELOPMENT
LATER TODAY --- THE LATEST HRRR FORECASTS SFC BASED CAPE TO EXCEED
3000 J/KG LATER THIS AFTERNOON IN THE ARKLAMISS DELTA REGION WITH
PRECIPITABLE WATER ~ 1.75 INCHES. WITH LITTLE IN THE WAY OF
CONVECTIVE INHIBITION...ISOLATED TO SCATTERED SHOWER/TSTMS SHOULD
INCREASE IN COVERAGE PER LATEST NEAR TERM GUIDANCE BY AROUND NOON.
RELATIVELY STRONG LOW-LEVEL FLOW MAY SUPPORT STRONG WIND GUSTS IN THE
MORE INTENSE STORMS...BUT NOT EXPECTING MUCH IN THE WAY OF STORM
ORGANIZATION. CONVECTION WILL WANE FAIRLY QUICK AFTER SUNSET WITH
LOSS OF HEATING.
EXPECT A SIMILAR CONVECTIVE SET-UP FOR MONDAY WITH HEATING OF A
WARM/HUMID AIRMASS SUPPORTING ANOTHER ROUND OF MAINLY AFTERNOON
SHOWER/THUNDERSTORMS. SUBTROPICAL JET POSITIONING AND ASSOCIATED
UPPER LEVEL JET DIVERGENCE SHOULD BE A LITTLE BETTER AND SUPPORTIVE
OF GOING WITH HIGHER PRECIP CHANCES OFFERED BY GUIDANCE.
OTHERWISE...RAIN CHANCES SHOULD BE ON THE INCREASE LATE MONDAY NIGHT
IN THE DELTA REGION AS A COLD FRONT BEGINS TO APPROACH FROM THE
NORTHWEST. /EC/
TUESDAY THROUGH NEXT SUNDAY
A COLD FRONT AND ASSOCIATED BAND OF SHOWERS/TSTMS WEDNESDAY WILL
BE MAIN FOCUS THIS PERIOD WITH BELOW NORMAL TEMPERATURES EXPECTED
WED-THURS AND A WARMING TREND FRI-SUN WITH OVERALL DRIER CONDITIONS.
MODEL SUITE FOR THE MEDIUM RANGE CONTINUES TO ALIGN INDICATING AN
AMPLIFIED ERN CONUS RIDGE WITH A DEEP TROUGH ACROSS THE CENTRAL
CONUS AND ATTENDANT SFC LOW IN THE NORTHERN MS VALLEY HELPING SHIFT
AN ELONGATED FRONTAL AXIS TOWARDS AND THROUGH THE LOWER MS VALLEY BY
MID WEEK. THE SLOWER TIMING OF WEATHER ELEMENTS IMPLEMENTED
YESTERDAY LOOKS ON TRACK AS EC REMAINS CONSISTENT WITH CONTINUED
SUPPORT FROM GEM/UKMET WHILE GFS HAS CONTINUED TO SLOW TOWARDS THIS
CAMP.
HAVE INCREASED POPS TUESDAY OVER PREVIOUS VALUES AS A LEAD S/WV
AHEAD OF THE MAIN TROUGH AXIS IS BECOMING MORE REALIZED ALONG THE
FRONTAL AXIS POSITIONED FROM A PADUCAH KY TO MEMPHIS TN TO LAKE
CHARLES LA LINE. GREATEST RAIN CHANCES WILL BE IN W/NW TUESDAY AS
THIS WAVE MOVES OVER THE REGION WHILST SURFACE CONVERGENCE AIDS AS A
LOW-LVL FOCUS. FARTHER EAST, INSTABILITY SHOULD BUILD AND ALLOW FOR
SOME DIURNALLY DRIVEN ISO/SCT TSTMS. THIS ACTIVITY SHOULD WANE
THROUGH TUES EVE WHILE SHOWERS CONTINUE ALONG BOUNDARY IN W/NW AREAS
IN CONJUNCTION OF HIGHER MOISTURE INFLUX/LIFT.
ATTM...HEAVIEST PRECIP AXIS LOOKS TO REMAIN TO OUR NW INTO AR BUT
WILL NEED TO MONITOR FOR NW/W DELTA LATE TUESDAY INTO WEDNESDAY FOR
FLASH FLOODING POTENTIAL BUT CONFIDENCE IS LOW WITH LACK OF DEEPER
FORCING AND NON-COINCIDING HIGH MOISTURE INFLUX. EC/GFS MODERATELY
AGREE THAT FRONT WILL BEGIN TO MOVE THROUGH AREA WED MORNING TO MID
DAY WHILE GREATER QG FORCING MAGNITUDES PIVOT OVER THE REGION ALONG
AND BEHIND THE FRONT WITH INSTABILITY BUILDING IN EAST MS AND INTO AL
WED AFTN. HAVE PLACED GREATEST POPS WED MRNG THROUGH THE EVENING. IF
CURRENT TIMING HOLDS, STRONG/SEVERE DOES NOT LOOK LIKELY FROM LACK OF
FULL DESTABILIZATION AND LACKLUSTER THERMO ENVIRONMENT. TEMPS SHOULD
BE HELD IN CHECK WEDNESDAY BEHIND FRONT AND WITH STRATIFORM
ANAFRONTAL RAIN WITH HIGHS IN THE LOW TO MID 70S. THESE VALUES WERE
CUT FROM MEXMOS BUT FURTHER CUTS MAY NEEDED.
RAIN/TSTMS SHOULD CLEAR OUT BY THURSDAY MORNING ALONG WITH CLOUDS
THROUGH THE DAY BUT TEMPS WILL BE BELOW NORMAL AS AREAS DIP INTO THE
UPPER 40S THURS MORNING WHILE RECOVERING INTO THE MID 70S THAT AFTN.
NW FLOW WILL CONTINUE FRI-SUN WITH OVERALL DRIER CONDITIONS
EXPECTED. HOWEVER, DESPITE AREA UNDER NW FLOW, ENOUGH MOISTURE AND
SOME DESTABILIZATION WITH SUBTLE WAVES MOVING THROUGH COULD TRIGGER
SOME SHOWER ACTIVITY IN THE NORTH BUT CONFIDENCE TO LOW TO PLACE
WEATHER WORDING IN AT THIS TIME. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 86 68 85 67 / 34 20 34 17
MERIDIAN 87 65 87 62 / 33 18 31 12
VICKSBURG 87 70 87 68 / 34 20 48 29
HATTIESBURG 87 68 88 65 / 40 17 29 12
NATCHEZ 85 69 85 68 / 43 18 56 26
GREENVILLE 87 69 84 67 / 28 20 54 43
GREENWOOD 87 69 86 68 / 28 20 50 29
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/EC/ALLEN/26
AREA FORECAST DISCUSSION
NWS JACKSON MS
444 AM CDT SUN MAY 11 2014
.TODAY THROUGH MONDAY NIGHT...
THE ARKLAMISS REGION WILL REMAIN IN A WARM/HUMID AND MAINLY DIURNAL
CONVECTIVE REGIME WITH PRONOUNCED SOUTHERLY LOW LEVEL FLOW. LARGER
SCALE FEATURES AIDING IN DEVELOPMENT OF CONVECTIVE PRECIPITATION ARE
SUBTLE...WITH THE EXIT REGION OF THE SUBTROPICAL JET HELPING TO
ENHANCE UPPER LEVEL DIVERGENCE AND PROVIDE SOME SUPPORT.
EXPECT DAYTIME HEATING TO BE A PRIMARY KEY IN SHOWER/TSTM DEVELOPMENT
LATER TODAY --- THE LATEST HRRR FORECASTS SFC BASED CAPE TO EXCEED
3000 J/KG LATER THIS AFTERNOON IN THE ARKLAMISS DELTA REGION WITH
PRECIPITABLE WATER ~ 1.75 INCHES. WITH LITTLE IN THE WAY OF
CONVECTIVE INHIBITION...ISOLATED TO SCATTERED SHOWER/TSTMS SHOULD
INCREASE IN COVERAGE PER LATEST NEAR TERM GUIDANCE BY AROUND NOON.
RELATIVELY STRONG LOW-LEVEL FLOW MAY SUPPORT STRONG WIND GUSTS IN THE
MORE INTENSE STORMS...BUT NOT EXPECTING MUCH IN THE WAY OF STORM
ORGANIZATION. CONVECTION WILL WANE FAIRLY QUICK AFTER SUNSET WITH
LOSS OF HEATING.
EXPECT A SIMILAR CONVECTIVE SET-UP FOR MONDAY WITH HEATING OF A
WARM/HUMID AIRMASS SUPPORTING ANOTHER ROUND OF MAINLY AFTERNOON
SHOWER/THUNDERSTORMS. SUBTROPICAL JET POSITIONING AND ASSOCIATED
UPPER LEVEL JET DIVERGENCE SHOULD BE A LITTLE BETTER AND SUPPORTIVE
OF GOING WITH HIGHER PRECIP CHANCES OFFERED BY GUIDANCE.
OTHERWISE...RAIN CHANCES SHOULD BE ON THE INCREASE LATE MONDAY NIGHT
IN THE DELTA REGION AS A COLD FRONT BEGINS TO APPROACH FROM THE
NORTHWEST. /EC/
TUESDAY THROUGH NEXT SUNDAY
A COLD FRONT AND ASSOCIATED BAND OF SHOWERS/TSTMS WEDNESDAY WILL
BE MAIN FOCUS THIS PERIOD WITH BELOW NORMAL TEMPERATURES EXPECTED
WED-THURS AND A WARMING TREND FRI-SUN WITH OVERALL DRIER CONDITIONS.
MODEL SUITE FOR THE MEDIUM RANGE CONTINUES TO ALIGN INDICATING AN
AMPLIFIED ERN CONUS RIDGE WITH A DEEP TROUGH ACROSS THE CENTRAL
CONUS AND ATTENDANT SFC LOW IN THE NORTHERN MS VALLEY HELPING SHIFT
AN ELONGATED FRONTAL AXIS TOWARDS AND THROUGH THE LOWER MS VALLEY BY
MID WEEK. THE SLOWER TIMING OF WEATHER ELEMENTS IMPLEMENTED
YESTERDAY LOOKS ON TRACK AS EC REMAINS CONSISTENT WITH CONTINUED
SUPPORT FROM GEM/UKMET WHILE GFS HAS CONTINUED TO SLOW TOWARDS THIS
CAMP.
HAVE INCREASED POPS TUESDAY OVER PREVIOUS VALUES AS A LEAD S/WV
AHEAD OF THE MAIN TROUGH AXIS IS BECOMING MORE REALIZED ALONG THE
FRONTAL AXIS POSITIONED FROM A PADUCAH KY TO MEMPHIS TN TO LAKE
CHARLES LA LINE. GREATEST RAIN CHANCES WILL BE IN W/NW TUESDAY AS
THIS WAVE MOVES OVER THE REGION WHILST SURFACE CONVERGENCE AIDS AS A
LOW-LVL FOCUS. FARTHER EAST, INSTABILITY SHOULD BUILD AND ALLOW FOR
SOME DIURNALLY DRIVEN ISO/SCT TSTMS. THIS ACTIVITY SHOULD WANE
THROUGH TUES EVE WHILE SHOWERS CONTINUE ALONG BOUNDARY IN W/NW AREAS
IN CONJUNCTION OF HIGHER MOISTURE INFLUX/LIFT.
ATTM...HEAVIEST PRECIP AXIS LOOKS TO REMAIN TO OUR NW INTO AR BUT
WILL NEED TO MONITOR FOR NW/W DELTA LATE TUESDAY INTO WEDNESDAY FOR
FLASH FLOODING POTENTIAL BUT CONFIDENCE IS LOW WITH LACK OF DEEPER
FORCING AND NON-COINCIDING HIGH MOISTURE INFLUX. EC/GFS MODERATELY
AGREE THAT FRONT WILL BEGIN TO MOVE THROUGH AREA WED MORNING TO MID
DAY WHILE GREATER QG FORCING MAGNITUDES PIVOT OVER THE REGION ALONG
AND BEHIND THE FRONT WITH INSTABILITY BUILDING IN EAST MS AND INTO AL
WED AFTN. HAVE PLACED GREATEST POPS WED MRNG THROUGH THE EVENING. IF
CURRENT TIMING HOLDS, STRONG/SEVERE DOES NOT LOOK LIKELY FROM LACK OF
FULL DESTABILIZATION AND LACKLUSTER THERMO ENVIRONMENT. TEMPS SHOULD
BE HELD IN CHECK WEDNESDAY BEHIND FRONT AND WITH STRATIFORM
ANAFRONTAL RAIN WITH HIGHS IN THE LOW TO MID 70S. THESE VALUES WERE
CUT FROM MEXMOS BUT FURTHER CUTS MAY NEEDED.
RAIN/TSTMS SHOULD CLEAR OUT BY THURSDAY MORNING ALONG WITH CLOUDS
THROUGH THE DAY BUT TEMPS WILL BE BELOW NORMAL AS AREAS DIP INTO THE
UPPER 40S THURS MORNING WHILE RECOVERING INTO THE MID 70S THAT AFTN.
NW FLOW WILL CONTINUE FRI-SUN WITH OVERALL DRIER CONDITIONS
EXPECTED. HOWEVER, DESPITE AREA UNDER NW FLOW, ENOUGH MOISTURE AND
SOME DESTABILIZATION WITH SUBTLE WAVES MOVING THROUGH COULD TRIGGER
SOME SHOWER ACTIVITY IN THE NORTH BUT CONFIDENCE TO LOW TO PLACE
WEATHER WORDING IN AT THIS TIME. /ALLEN/
&&
.AVIATION...PERSISTENT SOUTHERLY FLOW WILL CONTINUE A PATTERN OF LATE
NIGHT AND EARLY MORNING LOW STRATUS/FOG. CIGS/VSBYS WILL BE ERRATIC
AND MAY BOUNCE OFTEN BETWEEN MVFR AND LIFR CATEGORIES...WITH MOST
CONSISTENTLY POOR CONDITIONS IN THE HBG/PIB/JAN/HKS/MEI/NMM/GTR/CBM
AREAS. EXPECT CIGS TO LIFT AND VSBYS IMPROVE MID/LATE MORNING WITH
HEATING...BUT INCREASING INSTABILITY WILL LEAD TO SCATTERED MAINLY
AFTERNOON SHRA/TSRA. THIS PATTERN OF MORNING LOW CLOUDS AND AFTERNOON
CONVECTION SHOULD GENERALLY REPEAT ITSELF MONDAY. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 86 68 85 67 / 23 20 34 17
MERIDIAN 87 65 87 62 / 20 18 31 12
VICKSBURG 87 70 87 68 / 30 20 48 29
HATTIESBURG 87 68 88 65 / 43 17 29 12
NATCHEZ 85 69 85 68 / 43 18 56 26
GREENVILLE 87 69 84 67 / 28 20 54 43
GREENWOOD 87 69 86 68 / 20 20 50 29
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
EC/ALLEN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
655 AM EDT SUN MAY 11 2014
.SYNOPSIS... BERMUDA HIGH PRESSURE OVER THE ATLANTIC WILL EXTEND
WEST OVER THE REGION THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SUNDAY...
THE LATEST SURFACE ANALYSIS SHOWED WEAK HIGH PRESSURE OVER CENTRAL
NORTH CAROLINA WITH THE AREA ESSENTIALL PRECIPITATION-FREE AS MID-
LEVEL CLOUDS WERE CLEARING TOWARD THE SOUTHEAST. THINNING HIGH
CLOUDS FROM DEEP CONVECTION WELL UPSTREAM WERE DRIFTING IN FROM THE
NORTHWEST...AND A FEW OF THESE WILL BE NOTICED DURING THE DAY. THE
PRIMARY WEATHER CONCERN FOR TODAY IS THE POTENTIAL FOR ISOLATED TO
SCATTERED DEEP CONVECTION OVER THE FAR SOUTHEAST PART OF CENTRAL
NORTH CAROLINA THIS AFTERNOON INTO THIS EVENING.
THE GFS...NAM...AND RAP ARE DEFINITELY VERY SIMILAR IN THEIR
DEPICTION OF QPF OVER CENTRAL NORTH CAROLINA THIS AFTERNOON INTO THE
EARLY EVENING...WITH THE MEASURABLE LINE MAINLY ALONG AND SOUTH OF A
LINE FROM ABOUT WADESBORO TO TARBORO. IT IS IN THAT AREA WHERE THE
GREATEST PRECIPITABLE WATER VALUES ARE FORECAST THIS AFTERNOON ON
THE GFS AND NAM...TO ABOUT 1.5 INCHES...AND WHERE THERE IS MODEST
LIFT...850MB CONVERGENCE...AND WEAK UPPER DIFFLUENCE. MLCAPE IN THE
LOWEST KM IS FORECAST AROUND 500J/KG...WITH LIFTED INDICES A COUPLE
OF DEGREES OR SO BELOW 0C. BUFR SOUNDINGS AT KGSO...KRDU...AND KRWI
ARE BASICALLY STABLE TO DEEP CONVECTION...BUT THE KFAY BUFR SOUNDING
IS MORE UNSTABLE WITH A MORE LIMITED CAP. CONVECTIVE-ALLOWING MODELS
SUCH AS THE HRRR WRF SUGGESTS ISOLATED-TO-SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM DEVELOPING EARLY THIS AFTERNOON AND THEN
WANING WITH SUNSET. LIGHT WIND FIELDS SHOULD MAKE FOR FAIRLY
UNORGANIZED CONVECTION...AND 1000-500MB LAPSE RATES...ONLY TO ABOUT
6C/KM...AND DOWNDRAFT CAPE THAT IS FORECAST BELOW 500J/KG SHOULD
MAKE FOR LIMITED STRONG STORM POTENTIAL.
WILL LEAN TOWARD THE WARMER MAV MOS GUIDANCE ESPECIALLY SINCE IN
MOST PLACES IT IS EXPECTED THAT...EVEN WITH LIGHT WINDS...SUFFICIENT
MIXING SHOULD OCCUR TO MIX OUT DEW POINTS SOME. ALREADY IN PARTS OF
THE NORTHWEST PIEDMONT TO THE TRIANGLE...DEW POINTS HAVE FALLEN
BELOW 60F. HIGHS TODAY 85 TO 90.
TONIGHT...CLEAR TO PARTLY CLOUDY WITH THE POTENTIAL FOR SOME LOW
CLOUDS OR MORE LIKELY FOG IN THE LIGHT WIND FIELD LATE PARTICULARLY
WHERE ANY SHOWERS OCCUR. THE BEST POTENTIAL FOR THESE SHOULD BE
TOWARD THE SOUTHEAST WHERE SREF PROBABILITIES OF FOG ARE HIGHEST
RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. WILL NOTE PATCHY FOG
IN THE GRIDDED AND WORDED FORECASTS THERE. OVERNIGHT LOWS AROUND 60
TO THE MID 60S.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 300 AM SUNDAY...
SIMILAR CONDITIONS TO TODAY...SUNDAY...ARE EXPECTED MONDAY AND
MONDAY NIGHT WITH HIGHER PRECIPITABLE WATER VALUES CONTINUING OVER
ABOUT THE SOUTHERN TWO TIERS OF COUNTIES IN CENTRAL NORTH
CAROLINA...BETTER LIFT FORECAST IN THE AFTERNOON AND EARLY
EVENING...AND GREATER INSTABILITY COMPARED TO THE REST OF THE AREA.
IN FACT...THE GFS AND NAM MODELS BOTH FORECAST A SLIGHT INCREASE IN
INSTABILITY IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN MONDAY...
WITH LIFTED INDICES APPROACHING -5C IN THE AFTERNOON AND MLCAPE IN
THE LOWEST KM AS HIGH AS JUST OVER 1000J/KG. DOWNDRAFT CAPE IS ALSO
GREATER ON THE GFS WITH SLIGHTLY BETTER 1000-500MB LAPSE RATES...
CLOSER TO 6.5C/KM. THE BUFR SOUNDING FROM THE NAM TOWARD KFAY IS
MORE UNSTABLE MONDAY COMPARED TO SUNDAY...WHILE THE GFS BUFR
SOUNDING HAS JUST A SLIGHTLY BETTER CAP BETWEEN 700MB AND 850MB.
GUIDANCE POPS AND QPF ARE ONCE AGAIN VERY SIMILAR ON THE NAM AND THE
GFS...AND WILL NOTE THE POTENTIAL FOR ISOLATED-TO-SCATTERED
AFTERNOON AND EARLY EVENING SHOWERS AND THUNDERSTORMS IN AN AREA
VERY SIMILAR TO THAT FORECAST TODAY...EXCEPT EXPANDED WEST AND NORTH
EVER SO SLIGHTLY. BUFR SOUNDINGS TOWARD THE TRIAD AND KRDU STILL
SEEM A LITTLE TOO STABLE FOR DEEP CONVECTION. WILL CURRENTLY REFRAIN
FROM THE MENTION OF ANY STRONG STORMS FOR NOW IN THE HWO SO AS TO
MONITOR INSTABILITY AND MOISTURE TRENDS...AND AS ANY DEEP CONVECTION
SHOULD STILL BE FAIRLY UNORGANIZED.
1000-850MB THICKNESSES ARE WARMER MONDAY COMPARED TO TODAY AS
HEIGHTS ALOFT RISE...ENOUGH FOR HIGHS ABOUT TWO OR THREE DEGREES
WARMER MONDAY. OVERNIGHT MONDAY...WILL AGAIN NOTE THE POTENTIAL FOR
PATCHY FOG LATE...MAINLY SOUTH...IN A CONTINUED FAIRLY LIGHT WIND
FIELD. THIS IS SIMILAR TO THE SREF ORIENTATION OF LOW VISIBILITY
PROBABILITIES IN CENTRAL NORTH CAROLINA LATE MONDAY NIGHT. LOWS
MONDAY NIGHT MOSTLY LOWER TO MID 60S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...
TUESDAY AND WEDNESDAY: THIS PERIOD WILL START WITH RIDGING ALOFT AND
A BERMUDA HIGH OFF THE COAST...RESULTING IN WARM MOIST RETURN FLOW
INTO THE AREA. THE APPROACHING COLD FRONT WILL HELP PUSH THE RIDGE
OUT OF THE AREA LATE WEDNESDAY...WITH CONTINUED SOUTHERLY FLOW. THE
INCREASING TEMPERATURES AND MOISTURE WILL RESULT IN THE CHANCE FOR
MAINLY SCATTERED DIURNAL SHOWERS AND STORMS TO DEVELOP...ALTHOUGH
WITH THE LACK OF UPPER LEVEL FORCING...THE CHANCE OF SEVERE STORMS
CONTINUES TO BE LOW. OTHERWISE...EXPECT MAINLY DRY CONDITIONS. HIGHS
GREATEST ON TUESDAY...UPPER 80S TO AROUND 90 DEGREES...DECREASING
SLIGHTLY FOR WEDNESDAY...IN THE MID TO UPPER 80S. OVERNIGHT LOWS IN
THE MID 60S.
WEDNESDAY NIGHT THROUGH SATURDAY: THOUGH THERE ARE STILL TIMING
DIFFERENCES BETWEEN THE MODELS WITH THE APPROACHING LOW PRESSURE
SYSTEM AND ASSOCIATED COLD FRONT...THEY HAVE COME INTO BETTER
AGREEMENT OVER THE PAST FEW MODEL RUNS. THE LATEST MODEL RUNS
INDICATE THE BEST CHANCES FOR SHOWERS AND STORMS ON THURSDAY AFT/EVE
AS THE FRONT BEGINS PUSHING THROUGH THE AREA. CONFIDENCE IS
GRADUALLY INCREASING. EXPECT THE SHEAR AND INSTABILITY TO INCREASE
AS THE FRONT APPROACHES...AND WITH THE FORCING PRESENT...THE THREAT
FOR STRONG TO SEVERE STORMS EXISTS...WITH THE BEST POTENTIAL
INDICATED IN THE SANDHILLS AND COASTAL PLAIN. THERE IS STILL SOME
UNCERTAINTY REGARDING STORM INTENSITY AT THIS TIME GIVEN THE
DEPENDENCE ON FROPA TIMING AND THE MODEL DIFFERENCES IN THAT
REGARD...SO WILL CONTINUE TO MONITOR THE EVOLUTION OF THIS SYSTEM
AND WILL KEEP THE CURRENT WORDING IN THE HWO. EXPECT SHOWER AND
THUNDERSTORM CHANCES TO TAPER OFF BEHIND THE FRONT. TEMPERATURES
WILL DECREASE THROUGH THE PERIOD. HIGHS IN THE MID 70S TO LOW 80S
THURSDAY DOWN TO LOW/MID 70S SATURDAY. LOWS IN THE MID 50S TO AROUND
60 DEGREES THURSDAY NIGHT DOWN TO THE LOW TO MID 50S TO START THE
WEEKEND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 655 AM SUNDAY...
VFR CONDITIONS WILL BE THE RULE THROUGH THE 12Z VALID TAF PERIOD.
EXPECT A FEW LOCATIONS...NOTABLY TOWARD THE TRIAD...TO EXPERIENCE
MVFR CONDITIONS EARLY THIS MORNING...AND EVEN IFR BRIEFLY...WHERE
THE MOST RAIN OCCURRED IN CENTRAL NORTH CAROLINA SATURDAY. DURING
THIS AFTERNOON TOWARD KFAY...TO JUST EAST OF KRWI...ANTICIPATE
ISOLATED-TO-SCATTERED SHOWERS AND A THUNDERSTORM OR TWO IN BETTER
MOISTURE AND INSTABILITY. ANY SHOWERS SHOULD DIMINISH QUICKLY WITH
THE APPROACH OF SUNSET AND THE LOSS OF DAYTIME HEATING. WHILE
BOUNDARY LAYER WINDS ARE LIGHT...BOTH THE GFS AND NAM GUIDANCE
SUGGESTS SURFACE WINDS VEERING THIS MORNING AND THEN BECOMING
ABRUPTLY SOUTHERLY OVERALL BY LATE TODAY. LATE TONIGHT...THERE
SHOULD BE AREAS OF MVFR CONDITIONS IN LIGHT FOG...WITH THE BEST
CHANCE OF CONDITIONS BEING IFR FOR A PERIOD TOWARD KFAY WHERE LOW-
LEVEL MOISTURE WILL BE HIGHER AND WHERE...AGAIN...ISOLATED-TO-
SCATTERED SHOWERS SHOULD OCCUR THIS AFTERNOON INTO THE EVENING.
BEYOND THE 12Z VALID TAF PERIOD...DURING THE WEEK THERE SHOULD BE
INCREASING PROBABILITIES EACH DAY FOR LATE NIGHT AND EARLY MORNING
LOW CLOUDS AND/OR FOG. AGAIN TUESDAY MORNING IT WOULD SEEM THE
BETTER CHANCES OF SUCH WILL BE WHERE ANY AFTERNOON SHOWERS
OCCUR...SUCH AS TOWARD KFAY AND POSSIBLY KRWI. TUESDAY THROUGH
THURSDAY THE CHANCES FOR SHOWERS AND THUNDERSTORMS GRADUALLY
INCREASE AND SPREAD FROM WEST-TO-EAST ACROSS CENTRAL NORTH CAROLINA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...KCP
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
623 AM EDT SUN MAY 11 2014
.SYNOPSIS...
A DISSIPATING FRONTAL BOUNDARY WILL BRING A CHANCE OF RAIN THIS
AFTERNOON INTO EVENING. HIGH PRESSURE OFFSHORE WILL MAINTAIN WARM
TEMPERATURES THROUGH THE MIDDLE OF THE UPCOMING WEEK. A CHANCE OF
RAIN WILL ARRIVE LATE IN THE WEEK AS A COLD FRONT CROSSES THE
COAST FRIDAY. COOLER TEMPERATURES WILL PREVAIL INTO NEXT WEEKEND
IN WAKE OF THE FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 623 AM SUNDAY...TRIMMED RAIN CHANCES INTO MORNING AS
ACTIVITY HAS SHIFTED OVER THE OUTER COASTAL WATERS. LATEST
SATELLITE TRENDS POINT TO GOOD SURFACE HEATING TODAY...AND THIS
MAY SET THE STAGE FOR CONVECTION INTO THE AFTERNOON...AS LOW AND
MID LEVEL MOISTURE REMAINS AVAILABLE. ADJUSTMENTS WILL BE MADE TO
SKY COVER AS WELL TO REDUCE CLOUD COVERAGE IN THE EARLY GOING. THE
PREVIOUS EARLY MORNING DISCUSSION FOLLOWS.
ON-BOARD VAPOR SENSORS FROM SPACE SHOW A PLUME OF ELEVATED
PRECIPITABLE WATER DRAWING NE INTO SC AHEAD OF AN APPROACHING BUT
DECAYING FRONTAL SYSTEM EARLY THIS MORNING. MOSAIC RADAR
ANIMATIONS ARE PICKING UP ISOLATED RETURNS OVER THE EASTERN 1/3RD
OF SC AND VERY SE NC...AND THIS ACTIVITY APPEARS TO BE LINKED WITH
A DISTURBANCE ALOFT TRACKING OVERHEAD OF COLUMBIA SC CURRENTLY.
SURFACE ANALYSIS SHOWS A FRONTAL BOUNDARY OVER THE MID-
ATLANTIC...WITH LITTLE IDENTITY SEEN INTO THE CAROLINAS.
TIME-HEIGHT ANALYSIS SHOWS READILY AVAILABLE MOISTURE MUCH OF THE
DAY THROUGH ABOUT 15 KFT. FORECAST SOUNDINGS DEPICT A WEAKLY
FORCED BUT MODERATELY UNSTABLE AIR-MASS TODAY. SURFACE HEATING
THIS AFTERNOON WILL INTERACT WITH PWAT VALUES AROUND 1.5". RECENT
SATELLITE TRENDS SUGGEST DIFFERENTIAL HEATING THROUGH MORNING MAY
ALSO PLAY A ROLE IN TRIGGERING CONVECTION LATER TODAY. SURFACE
OUTFLOWS IN THE RELATIVELY MOIST AIR-MASS WILL ALSO FAVOR MORE
INITIATION. CONVECTIVE MODE OBSERVATIONS SO FAR SHOW PULSE AND LOW
TOP SHOWERS CONGRUENT WITH HIGH PWAT LOW BULK-SHEAR REGIMES.
LOSS OF DIURNAL HEATING AND EXITING IMPULSES ALOFT WILL BRING A
DIMINISHING TREND IN CONVECTION BY LATE EVENING. MINIMUM TEMPS
INTO EARLY MONDAY MIDDLE 60S INLAND TO UPPER 60S NEAR THE COAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...MID TO UPPER RIDGE WILL BE BUILDING BACK UP
THROUGH THE SOUTHEAST AS BERMUDA HIGH CONTINUES TO PRODUCE A
MOIST SOUTHWESTERLY RETURN FLOW EARLY TO MID WEEK. GRADIENT
REMAINS FAIRLY WEAK THROUGH THE PERIOD WHICH SHOULD ALLOW SEA/LAND
BREEZE TO DOMINATE. ALTHOUGH CONVERGENCE ALONG THE SEABREEZE
SHOULD PRODUCE SOME CU DEVELOPMENT...THERE SHOULD BE ENOUGH DRY AIR AND
SUBSIDENCE ALOFT TO LIMIT SHOWER ACTIVITY. CAN NOT COMPLETELY RULE
OUT AN ISOLATED SHWR OR TWO...BUT WILL MOST LIKELY KEEP POPS
SILENT. MOISTURE PROFILES ALSO CONTINUE TO SHOW UPPER LEVEL
MOISTURE AND THEREFORE MAY SEE SOME CIRRUS STREAMING ACROSS THE
AREA IN WESTERLY FLOW ABOVE H40.
AS FOR TEMPS...THE DECENT RIDGE ALOFT WILL KEEP H5 HEIGHTS AROUND
588 DEM. MAY SEE A SOME CLOUDS BLOCKING THE SUN AT TIMES BUT
OVERALL EXPECT WARM START TO EACH DAY WITH OVERNIGHT TEMPS
REMAINING CLOSER TO 70...LEADING TO TEMPS WELL INTO THE 80S MOST
PLACES WITH STRONGER MAY SUNSHINE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MID TO UPPER RIDGE REMAINS AMPLIFIED UP
THE EAST COAST AS TROUGH DIGS THROUGH THE MISSISSIPPI VALLEY
WEDNESDAY. SFC HIGH MOVING OFF THE NEW ENGLAND COAST BEGINS TO
DOMINATE WITH MORE OF NORTH TO SOUTH ELONGATED HIGH PRESSURE
SYSTEM DOWN INTO THE CARIBBEAN. THIS WILL HELP THE WINDS BACK TO A
MORE S-SE FLOW. THE DEEPENING MID TO UPPER TROUGH WILL PUSH
EASTWARD DISPLACING THE RIDGE EAST AND PUSHING A COLD FRONT EAST
INTO THE CAROLINAS ON THURS. AT THE SAME TIME AN IMPULSE WILL RIDE
UP AROUND THE ATLANTIC RIDGE FROM THE BAHAMAS AND MAY ADD TO THE
OVERALL MOISTURE REACHING INTO THE CAROLINAS ON THURS. EXPECT
CONVECTION DEVELOPMENT ALONG AN AHEAD OF THIS COLD FRONT AS IT
MOVES EASTWARD REACHING THE COAST THURS NIGHT INTO FRI MORNING.
WILL CONTINUE WITH MAIN FOCUS OF CONVECTION ON THURS INTO THURS
NIGHT.
ONCE THE FRONT MOVES THROUGH BY FRIDAY DRIER AND COOLER AIR WILL
MOVE IN WITH 850 TEMPS DROPPING FROM AROUND 15 C WED AFTN DOWN TO
ABOUT 5 C BY SAT MORNING. H5 HEIGHTS WILL DROP AROUND 20 DEM BY
SAT MORNING. OVERALL EXPECT COOLER WEATHER HEADING INTO NEXT
WEEKEND. TEMPS WILL RUN SEVERAL DEGREES ABOVE NORMAL TO START
REACHING WELL INTO THE 80S ON WED. THE DEWPOINT TEMPS WILL BE IN
THE MID 60S AHEAD OF THE FRONT BUT WILL DROP INTO THE 40S BY THE
WEEKEND WITH TEMPS SEVERAL DEGREES BELOW NORMAL. EXPECT HIGH TEMPS
ONLY IN THE LOWER TO MID 70S FOR THE WEEKEND.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...RADAR IMAGERY SHOWS SOME SHOWERS OVER SOUTH CAROLINA
ASSOCIATED WITH AN UPPER DISTURBANCE. THE LATEST HRRR RUNS DISSIPATE
MUCH OF THIS ACTIVITY BEFORE IT REACHES NC. PERIODS OF MVFR/IFR
CIGS/VSBYS IN THE EARLY MORNING HOURS...AS THIS MOIST LOW LEVEL
ENVIRONMENT HAS PROVEN TO BE CONDUCIVE FOR FOG/STRATUS. GUIDANCE
FAVORS IFR STRATUS AND REDUCED VSBYS AT KFLO/KLBT. TEMPO IFR
CIGS/VSBYS CANNOT BE RULED OUT ALONG THE COAST AS WELL. ISOLATED
CONVECTION IS POSSIBLE LATER TODAY WITH SURFACE HEATING AS THE LOW
LEVELS MOISTEN. THE SEA BREEZE WOULD LIKELY BE THE FOCUS FOR ANY
SHOWER ACTIVITY...WITH THE BEST CHANCES AT THE INLAND TERMINALS
LATER THIS AFTERNOON. WILL MAINTAIN VCSH ATTM SINCE COVERAGE WILL
BE SPOTTY AT BEST. SOUTHWEST WINDS 5-10 KTS WILL BECOME SOUTH
AROUND 10 KTS IN THE AFTERNOON AS THE SEA BREEZE PUSHES INLAND.
EXTENDED OUTLOOK...EARLY MORNING IFR FG/STRATUS IS POSSIBLE THROUGH
THE EXTENDED PERIOD...MAINLY INLAND TERMINALS. OTHERWISE VFR.
CHANCE OF SHOWERS/TSTMS MONDAY...MAINLY LATE WEDNESDAY INTO THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 623 AM SUNDAY...MANAGEABLE MARINE CONDITIONS EXPECTED TODAY
AS A WEAK COLD FRONT N AND W OF THE WATERS DISSIPATES. THIS WILL
LEAVE A LIGHT SW WIND FLOW ACROSS THE WATERS THROUGH TONIGHT. SEAS
GENERALLY 2-3 FEET...IN A MIX OF SSW WAVES 1-2 FEET EVERY 4-5 SEC
AND SE WAVES 1-2 FT EVERY 7-8 SECONDS. ISOLATED TSTMS ARE POSSIBLE
NEAR SHORE THIS AFTERNOON INTO THIS EVENING...AND THE MOTION WILL
BE FROM SW TO NE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...SOUTHERLY FLOW AROUND BERMUDA HIGH WILL
CONTINUE THROUGH EARLY NEXT WEEK. EXPECT S-SW WINDS 10-15 KTS
THROUGH THE PERIOD...WITH LITTLE FLUCTUATION IN STRENGTH OR
DIRECTION EITHER DAY. THESE WINDS PLUS THE PERSISTENT FETCH AROUND
THE OFFSHORE HIGH PRESSURE WILL CREATE 2-3 FT SEAS EACH DAY...WITH
A WAVE SPECTRUM COMPRISED OF A SOUTHERLY 4-5 SEC WIND WAVE AND A
LOW-AMPLITUDE SE GROUND SWELL.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...HIGH PRESSURE BECOMES MORE ORIENTED NORTH TO
SOUTH FROM THE WATERS OFF OF NEW ENGLAND COAST DOWN TO THE LOCAL
WATERS OFF THE SOUTHEAST COAST THROUGH MID WEEK. THE FLOW AROUND
THE HIGH WILL REMAIN ORIENTED NORTH TO SOUTH WITH WINDS S-SE TO
START AROUND 10 TO 15 KTS. BY THURSDAY...GRADIENT TIGHTENS AS
DIGGING MID TO UPPER TROUGH PUSHES A COLD FRONT EAST INTO THE
CAROLINAS. THIS WILL PRODUCE AN INCREASE IN WINDS UP AROUND 15
KTS. IN TURN...YOU CAN EXPECT AN INCREASE IN SEAS UP FROM AROUND 2
TO 3 FT EARLY WED TO 3 TO 4 FT BY THURS NIGHT. BEST SHOT OF
SHOWERS AND THUNDERSTORMS WILL COME LATE THURS ASSOCIATED WITH
COLD FRONT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MJC/BJR
MARINE...
AREA FORECAST DISCUSSION...CORRECTED
NWS WILMINGTON NC
603 AM EDT SUN MAY 11 2014
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL MAINTAIN ABOVE NORMAL TEMPERATURES
THROUGH THE MIDDLE OF THE WEEK. A COLD FRONT WILL APPROACH FROM
THE WEST ON THURSDAY...CROSSING THE AREA BY FRIDAY. COOLER
TEMPERATURES WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 4 AM SUNDAY...ON-BOARD VAPOR SENSORS FROM SPACE SHOW A PLUME
OF ELEVATED PRECIPITABLE WATER DRAWING NE INTO SC AHEAD OF AN
APPROACHING BUT DECAYING FRONTAL SYSTEM EARLY THIS MORNING. MOSAIC
RADAR ANIMATIONS ARE PICKING UP ISOLATED RETURNS OVER THE EASTERN
1/3RD OF SC AND VERY SE NC...AND THIS ACTIVITY APPEARS TO BE
LINKED WITH A DISTURBANCE ALOFT TRACKING OVERHEAD OF COLUMBIA SC
CURRENTLY. SURFACE ANALYSIS SHOWS A FRONTAL BOUNDARY OVER THE MID-
ATLANTIC...WITH LITTLE IDENTITY SEEN INTO THE CAROLINAS.
TIME-HEIGHT ANALYSIS SHOWS READILY AVAILABLE MOISTURE MUCH OF THE
DAY THROUGH ABOUT 15 KFT. FORECAST SOUNDINGS DEPICT A WEAKLY
FORCED BUT MODERATELY UNSTABLE AIR-MASS TODAY. SURFACE HEATING
THIS AFTERNOON WILL INTERACT WITH PWAT VALUES AROUND 1.5". RECENT
SATELLITE TRENDS SUGGEST DIFFERENTIAL HEATING THROUGH MORNING MAY
ALSO PLAY A ROLE IN TRIGGERING CONVECTION LATER TODAY. SURFACE
OUTFLOWS IN THE RELATIVELY MOIST AIR-MASS WILL ALSO FAVOR MORE
INITIATION. CONVECTIVE MODE OBSERVATIONS SO FAR SHOW PULSE AND LOW
TOP SHOWERS CONGRUENT WITH HIGH PWAT LOW BULK-SHEAR REGIMES.
LOSS OF DIURNAL HEATING AND EXITING IMPULSES ALOFT WILL BRING A
DIMINISHING TREND IN CONVECTION BY LATE EVENING. MINIMUM TEMPS
INTO EARLY MONDAY MIDDLE 60S INLAND TO UPPER 60S NEAR THE COAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...MID TO UPPER RIDGE WILL BE BUILDING BACK UP
THROUGH THE SOUTHEAST AS BERMUDA HIGH CONTINUES TO PRODUCE A
MOIST SOUTHWESTERLY RETURN FLOW EARLY TO MID WEEK. GRADIENT
REMAINS FAIRLY WEAK THROUGH THE PERIOD WHICH SHOULD ALLOW SEA/LAND
BREEZE TO DOMINATE. ALTHOUGH CONVERGENCE ALONG THE SEABREEZE
SHOULD PRODUCE SOME CU DEVELOPMENT...THERE SHOULD BE ENOUGH DRY AIR AND
SUBSIDENCE ALOFT TO LIMIT SHOWER ACTIVITY. CAN NOT COMPLETELY RULE
OUT AN ISOLATED SHWR OR TWO...BUT WILL MOST LIKELY KEEP POPS
SILENT. MOISTURE PROFILES ALSO CONTINUE TO SHOW UPPER LEVEL
MOISTURE AND THEREFORE MAY SEE SOME CIRRUS STREAMING ACROSS THE
AREA IN WESTERLY FLOW ABOVE H40.
AS FOR TEMPS...THE DECENT RIDGE ALOFT WILL KEEP H5 HEIGHTS AROUND
588 DEM. MAY SEE A SOME CLOUDS BLOCKING THE SUN AT TIMES BUT
OVERALL EXPECT WARM START TO EACH DAY WITH OVERNIGHT TEMPS
REMAINING CLOSER TO 70...LEADING TO TEMPS WELL INTO THE 80S MOST
PLACES WITH STRONGER MAY SUNSHINE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MID TO UPPER RIDGE REMAINS AMPLIFIED UP
THE EAST COAST AS TROUGH DIGS THROUGH THE MISSISSIPPI VALLEY
WEDNESDAY. SFC HIGH MOVING OFF THE NEW ENGLAND COAST BEGINS TO
DOMINATE WITH MORE OF NORTH TO SOUTH ELONGATED HIGH PRESSURE
SYSTEM DOWN INTO THE CARIBBEAN. THIS WILL HELP THE WINDS BACK TO A
MORE S-SE FLOW. THE DEEPENING MID TO UPPER TROUGH WILL PUSH
EASTWARD DISPLACING THE RIDGE EAST AND PUSHING A COLD FRONT EAST
INTO THE CAROLINAS ON THURS. AT THE SAME TIME AN IMPULSE WILL RIDE
UP AROUND THE ATLANTIC RIDGE FROM THE BAHAMAS AND MAY ADD TO THE
OVERALL MOISTURE REACHING INTO THE CAROLINAS ON THURS. EXPECT
CONVECTION DEVELOPMENT ALONG AN AHEAD OF THIS COLD FRONT AS IT
MOVES EASTWARD REACHING THE COAST THURS NIGHT INTO FRI MORNING.
WILL CONTINUE WITH MAIN FOCUS OF CONVECTION ON THURS INTO THURS
NIGHT.
ONCE THE FRONT MOVES THROUGH BY FRIDAY DRIER AND COOLER AIR WILL
MOVE IN WITH 850 TEMPS DROPPING FROM AROUND 15 C WED AFTN DOWN TO
ABOUT 5 C BY SAT MORNING. H5 HEIGHTS WILL DROP AROUND 20 DEM BY
SAT MORNING. OVERALL EXPECT COOLER WEATHER HEADING INTO NEXT
WEEKEND. TEMPS WILL RUN SEVERAL DEGREES ABOVE NORMAL TO START
REACHING WELL INTO THE 80S ON WED. THE DEWPOINT TEMPS WILL BE IN
THE MID 60S AHEAD OF THE FRONT BUT WILL DROP INTO THE 40S BY THE
WEEKEND WITH TEMPS SEVERAL DEGREES BELOW NORMAL. EXPECT HIGH TEMPS
ONLY IN THE LOWER TO MID 70S FOR THE WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...RADAR IMAGERY SHOWS SOME SHOWERS OVER SOUTH CAROLINA
ASSOCIATED WITH AN UPPER DISTURBANCE. THE LATEST HRRR RUNS DISSIPATE
MUCH OF THIS ACTIVITY BEFORE IT REACHES NC. PERIODS OF MVFR/IFR
CIGS/VSBYS IN THE EARLY MORNING HOURS...AS THIS MOIST LOW LEVEL
ENVIRONMENT HAS PROVEN TO BE CONDUCIVE FOR FOG/STRATUS. GUIDANCE
FAVORS IFR STRATUS AND REDUCED VSBYS AT KFLO/KLBT. TEMPO IFR
CIGS/VSBYS CANNOT BE RULED OUT ALONG THE COAST AS WELL. ISOLATED
CONVECTION IS POSSIBLE LATER TODAY WITH SURFACE HEATING AS THE LOW
LEVELS MOISTEN. THE SEA BREEZE WOULD LIKELY BE THE FOCUS FOR ANY
SHOWER ACTIVITY...WITH THE BEST CHANCES AT THE INLAND TERMINALS
LATER THIS AFTERNOON. WILL MAINTAIN VCSH ATTM SINCE COVERAGE WILL
BE SPOTTY AT BEST. SOUTHWEST WINDS 5-10 KTS WILL BECOME SOUTH
AROUND 10 KTS IN THE AFTERNOON AS THE SEA BREEZE PUSHES INLAND.
EXTENDED OUTLOOK...EARLY MORNING IFR FG/STRATUS IS POSSIBLE THROUGH
THE EXTENDED PERIOD...MAINLY INLAND TERMINALS. OTHERWISE VFR.
CHANCE OF SHOWERS/TSTMS MONDAY...MAINLY LATE WEDNESDAY INTO THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 4 AM SUNDAY...MANAGEABLE MARINE CONDITIONS EXPECTED TODAY AS
A WEAK COLD FRONT N AND W OF THE WATERS DISSIPATES. THIS WILL
LEAVE A LIGHT SW WIND FLOW ACROSS THE WATERS THROUGH TONIGHT. SEAS
GENERALLY 2-3 FEET...IN A MIX OF SSW WAVES 1-2 FEET EVERY 4-5 SEC
AND SE WAVES 1-2 FT EVERY 7-8 SECONDS. ISOLATED TSTMS ARE POSSIBLE
NEAR SHORE THIS AFTERNOON INTO THIS EVENING...AND THE MOTION WILL BE
FROM SW TO NE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...SOUTHERLY FLOW AROUND BERMUDA HIGH WILL
CONTINUE THROUGH EARLY NEXT WEEK. EXPECT S-SW WINDS 10-15 KTS
THROUGH THE PERIOD...WITH LITTLE FLUCTUATION IN STRENGTH OR
DIRECTION EITHER DAY. THESE WINDS PLUS THE PERSISTENT FETCH AROUND
THE OFFSHORE HIGH PRESSURE WILL CREATE 2-3 FT SEAS EACH DAY...WITH
A WAVE SPECTRUM COMPRISED OF A SOUTHERLY 4-5 SEC WIND WAVE AND A
LOW-AMPLITUDE SE GROUND SWELL.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...HIGH PRESSURE BECOMES MORE ORIENTED NORTH TO
SOUTH FROM THE WATERS OFF OF NEW ENGLAND COAST DOWN TO THE LOCAL
WATERS OFF THE SOUTHEAST COAST THROUGH MID WEEK. THE FLOW AROUND
THE HIGH WILL REMAIN ORIENTED NORTH TO SOUTH WITH WINDS S-SE TO
START AROUND 10 TO 15 KTS. BY THURSDAY...GRADIENT TIGHTENS AS
DIGGING MID TO UPPER TROUGH PUSHES A COLD FRONT EAST INTO THE
CAROLINAS. THIS WILL PRODUCE AN INCREASE IN WINDS UP AROUND 15
KTS. IN TURN...YOU CAN EXPECT AN INCREASE IN SEAS UP FROM AROUND 2
TO 3 FT EARLY WED TO 3 TO 4 FT BY THURS NIGHT. BEST SHOT OF
SHOWERS AND THUNDERSTORMS WILL COME LATE THURS ASSOCIATED WITH
COLD FRONT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MJC/BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
406 AM EDT SUN MAY 11 2014
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL MAINTAIN ABOVE NORMAL TEMPERATURES
THROUGH THE MIDDLE OF THE WEEK. A COLD FRONT WILL APPROACH FROM
THE WEST ON THURSDAY...CROSSING THE AREA BY FRIDAY. COOLER
TEMPERATURES WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 4 AM SUNDAY...ONBOARD VAPOR SENSORS FROM SPACE SHOW A PLUME
OF ELEVATED PRECIPITABLE WATER DRAWING NE INTO SC AHEAD OF AN
APPROACHING BUT DECAYING FRONTAL SYSTEM EARLY THIS MORNING. MOSAIC
RADAR ANIMATIONS ARE PICKING UP ISOLATED RETURNS OVER THE EASTERN
1/3RD OF SC AND VERY SE NC...AND THIS ACTIVITY APPEARS TO BE
LINKED WITH A DISTURBANCE ALOFT TRACKING OVERHEAD OF COLUMBIA SC
CURRENTLY. SURFACE ANALYSIS SHOWS A FRONTAL BOUNDARY OVER THE MID-
ATLANTIC...WITH LITTLE IDENTITY SEEN INTO THE CAROLINAS.
TIME-HEIGHT ANALYSIS SHOWS READILY AVAILABLE MOISTURE MUCH OF THE
DAY THROUGH ABOUT 15 KFT. FORECAST SOUNDINGS DEPICT A WEAKLY
FORCED BUT MODERATELY UNSTABLE AIR-MASS TODAY. SURFACE HEATING
THIS AFTERNOON WILL INTERACT WITH PWAT VALUES AROUND 1.5". RECENT
SATELLITE TRENDS SUGGEST DIFFERENTIAL HEATING THROUGH MORNING MAY
ALSO PLAY A ROLE IN TRIGGERING CONVECTION LATER TODAY. SURFACE
OUTFLOWS IN THE RELATIVELY MOIST AIR-MASS WILL ALSO FAVOR MORE
INITIATION. CONVECTIVE MODE OBSERVATIONS SO FAR SHOW PULSE AND LOW
TOP SHOWERS CONGRUENT WITH HIGH PWAT LOW BULK-SHEAR REGIMES.
LOSS OF DIURNAL HEATING AND EXITING IMPULSES ALOFT WILL BRING A
DIMINISHING TREND IN CONVECTION BY LATE EVENING. MINIMUM TEMPS
INTO EARLY MONDAY MIDDLE 60S INLAND TO UPPER 60S NEAR THE COAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...MID TO UPPER RIDGE WILL BE BUILDING BACK UP
THROUGH THE SOUTHEAST AS BERMUDA HIGH CONTINUES TO PRODUCE A
MOIST SOUTHWESTERLY RETURN FLOW EARLY TO MID WEEK. GRADIENT
REMAINS FAIRLY WEAK THROUGH THE PERIOD WHICH SHOULD ALLOW SEA/LAND
BREEZE TO DOMINATE. ALTHOUGH CONVERGENCE ALONG THE SEABREEZE
SHOULD PRODUCE SOME CU DEVELOPMENT...THERE SHOULD BE ENOUGH DRY AIR AND
SUBSIDENCE ALOFT TO LIMIT SHOWER ACTIVITY. CAN NOT COMPLETELY RULE
OUT AN ISOLATED SHWR OR TWO...BUT WILL MOST LIKELY KEEP POPS
SILENT. MOISTURE PROFILES ALSO CONTINUE TO SHOW UPPER LEVEL
MOISTURE AND THEREFORE MAY SEE SOME CIRRUS STREAMING ACROSS THE
AREA IN WESTERLY FLOW ABOVE H40.
AS FOR TEMPS...THE DECENT RIDGE ALOFT WILL KEEP H5 HEIGHTS AROUND
588 DEM. MAY SEE A SOME CLOUDS BLOCKING THE SUN AT TIMES BUT
OVERALL EXPECT WARM START TO EACH DAY WITH OVERNIGHT TEMPS
REMAINING CLOSER TO 70...LEADING TO TEMPS WELL INTO THE 80S MOST
PLACES WITH STRONGER MAY SUNSHINE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...MID TO UPPER RIDGE REMAINS AMPLIFIED UP
THE EAST COAST AS TROUGH DIGS THROUGH THE MISSISSIPPI VALLEY
WEDNESDAY. SFC HIGH MOVING OFF THE NEW ENGLAND COAST BEGINS TO
DOMINATE WITH MORE OF NORTH TO SOUTH ELONGATED HIGH PRESSURE
SYSTEM DOWN INTO THE CARIBBEAN. THIS WILL HELP THE WINDS BACK TO A
MORE S-SE FLOW. THE DEEPENING MID TO UPPER TROUGH WILL PUSH
EASTWARD DISPLACING THE RIDGE EAST AND PUSHING A COLD FRONT EAST
INTO THE CAROLINAS ON THURS. AT THE SAME TIME AN IMPULSE WILL RIDE
UP AROUND THE ATLANTIC RIDGE FROM THE BAHAMAS AND MAY ADD TO THE
OVERALL MOISTURE REACHING INTO THE CAROLINAS ON THURS. EXPECT
CONVECTION DEVELOPMENT ALONG AN AHEAD OF THIS COLD FRONT AS IT
MOVES EASTWARD REACHING THE COAST THURS NIGHT INTO FRI MORNING.
WILL CONTINUE WITH MAIN FOCUS OF CONVECTION ON THURS INTO THURS
NIGHT.
ONCE THE FRONT MOVES THROUGH BY FRIDAY DRIER AND COOLER AIR WILL
MOVE IN WITH 850 TEMPS DROPPING FROM AROUND 15 C WED AFTN DOWN TO
ABOUT 5 C BY SAT MORNING. H5 HEIGHTS WILL DROP AROUND 20 DEM BY
SAT MORNING. OVERALL EXPECT COOLER WEATHER HEADING INTO NEXT
WEEKEND. TEMPS WILL RUN SEVERAL DEGREES ABOVE NORMAL TO START
REACHING WELL INTO THE 80S ON WED. THE DEWPOINT TEMPS WILL BE IN
THE MID 60S AHEAD OF THE FRONT BUT WILL DROP INTO THE 40S BY THE
WEEKEND WITH TEMPS SEVERAL DEGREES BELOW NORMAL. EXPECT HIGH TEMPS
ONLY IN THE LOWER TO MID 70S FOR THE WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...RADAR IMAGERY SHOWS SOME SHOWERS OVER SOUTH CAROLINA
ASSOCIATED WITH AN UPPER DISTURBANCE. THE LATEST HRRR RUNS DISSIPATE
MUCH OF THIS ACTIVITY BEFORE IT REACHES NC. PERIODS OF MVFR/IFR
CIGS/VSBYS IN THE EARLY MORNING HOURS...AS THIS MOIST LOW LEVEL
ENVIRONMENT HAS PROVEN TO BE CONDUCIVE FOR FOG/STRATUS. GUIDANCE
FAVORS IFR STRATUS AND REDUCED VSBYS AT KFLO/KLBT. TEMPO IFR
CIGS/VSBYS CANNOT BE RULED OUT ALONG THE COAST AS WELL. ISOLATED
CONVECTION IS POSSIBLE LATER TODAY WITH SURFACE HEATING AS THE LOW
LEVELS MOISTEN. THE SEA BREEZE WOULD LIKELY BE THE FOCUS FOR ANY
SHOWER ACTIVITY...WITH THE BEST CHANCES AT THE INLAND TERMINALS
LATER THIS AFTERNOON. WILL MAINTAIN VCSH ATTM SINCE COVERAGE WILL
BE SPOTTY AT BEST. SOUTHWEST WINDS 5-10 KTS WILL BECOME SOUTH
AROUND 10 KTS IN THE AFTERNOON AS THE SEA BREEZE PUSHES INLAND.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 4 AM SUNDAY...MANAGEABLE MARINE CONDITIONS EXPECTED TODAY AS
A WEAK COLD FRONT N AND W OF THE WATERS DISSIPATES. THIS WILL
LEAVE A LIGHT SW WIND FLOW ACROSS THE WATERS THROUGH TONIGHT. SEAS
GENERALLY 2-3 FEET...IN A MIX OF SSW WAVES 1-2 FEET EVERY 4-5 SEC
AND SE WAVES 1-2 FT EVERY 7-8 SECONDS. ISOLATED TSTMS ARE POSSIBLE
NEAR SHORE THIS AFTERNOON INTO THIS EVENING...AND THE MOTION WILL BE
FROM SW TO NE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SUNDAY...SOUTHERLY FLOW AROUND BERMUDA HIGH WILL
CONTINUE THROUGH EARLY NEXT WEEK. EXPECT S-SW WINDS 10-15 KTS
THROUGH THE PERIOD...WITH LITTLE FLUCTUATION IN STRENGTH OR
DIRECTION EITHER DAY. THESE WINDS PLUS THE PERSISTENT FETCH AROUND
THE OFFSHORE HIGH PRESSURE WILL CREATE 2-3 FT SEAS EACH DAY...WITH
A WAVE SPECTRUM COMPRISED OF A SOUTHERLY 4-5 SEC WIND WAVE AND A
LOW-AMPLITUDE SE GROUND SWELL.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 330 AM SUNDAY...HIGH PRESSURE BECOMES MORE ORIENTED NORTH TO
SOUTH FROM THE WATERS OFF OF NEW ENGLAND COAST DOWN TO THE LOCAL
WATERS OFF THE SOUTHEAST COAST THROUGH MID WEEK. THE FLOW AROUND
THE HIGH WILL REMAIN ORIENTED NORTH TO SOUTH WITH WINDS S-SE TO
START AROUND 10 TO 15 KTS. BY THURSDAY...GRADIENT TIGHTENS AS
DIGGING MID TO UPPER TROUGH PUSHES A COLD FRONT EAST INTO THE
CAROLINAS. THIS WILL PRODUCE AN INCREASE IN WINDS UP AROUND 15
KTS. IN TURN...YOU CAN EXPECT AN INCREASE IN SEAS UP FROM AROUND 2
TO 3 FT EARLY WED TO 3 TO 4 FT BY THURS NIGHT. BEST SHOT OF
SHOWERS AND THUNDERSTORMS WILL COME LATE THURS ASSOCIATED WITH
COLD FRONT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MJC/BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EDT SUN MAY 11 2014
.SYNOPSIS... BERMUDA HIGH PRESSURE OVER THE ATLANTIC WILL EXTEND
WEST OVER THE REGION THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SUNDAY...
THE LATEST SURFACE ANALYSIS SHOWED WEAK HIGH PRESSURE OVER CENTRAL
NORTH CAROLINA WITH THE AREA ESSENTIALL PRECIPITATION-FREE AS MID-
LEVEL CLOUDS WERE CLEARING TOWARD THE SOUTHEAST. THINNING HIGH
CLOUDS FROM DEEP CONVECTION WELL UPSTREAM WERE DRIFTING IN FROM THE
NORTHWEST...AND A FEW OF THESE WILL BE NOTICED DURING THE DAY. THE
PRIMARY WEATHER CONCERN FOR TODAY IS THE POTENTIAL FOR ISOLATED TO
SCATTERED DEEP CONVECTION OVER THE FAR SOUTHEAST PART OF CENTRAL
NORTH CAROLINA THIS AFTERNOON INTO THIS EVENING.
THE GFS...NAM...AND RAP ARE DEFINITELY VERY SIMILAR IN THEIR
DEPICTION OF QPF OVER CENTRAL NORTH CAROLINA THIS AFTERNOON INTO THE
EARLY EVENING...WITH THE MEASURABLE LINE MAINLY ALONG AND SOUTH OF A
LINE FROM ABOUT WADESBORO TO TARBORO. IT IS IN THAT AREA WHERE THE
GREATEST PRECIPITABLE WATER VALUES ARE FORECAST THIS AFTERNOON ON
THE GFS AND NAM...TO ABOUT 1.5 INCHES...AND WHERE THERE IS MODEST
LIFT...850MB CONVERGENCE...AND WEAK UPPER DIFFLUENCE. MLCAPE IN THE
LOWEST KM IS FORECAST AROUND 500J/KG...WITH LIFTED INDICES A COUPLE
OF DEGREES OR SO BELOW 0C. BUFR SOUNDINGS AT KGSO...KRDU...AND KRWI
ARE BASICALLY STABLE TO DEEP CONVECTION...BUT THE KFAY BUFR SOUNDING
IS MORE UNSTABLE WITH A MORE LIMITED CAP. CONVECTIVE-ALLOWING MODELS
SUCH AS THE HRRR WRF SUGGESTS ISOLATED-TO-SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM DEVELOPING EARLY THIS AFTERNOON AND THEN
WANING WITH SUNSET. LIGHT WIND FIELDS SHOULD MAKE FOR FAIRLY
UNORGANIZED CONVECTION...AND 1000-500MB LAPSE RATES...ONLY TO ABOUT
6C/KM...AND DOWNDRAFT CAPE THAT IS FORECAST BELOW 500J/KG SHOULD
MAKE FOR LIMITED STRONG STORM POTENTIAL.
WILL LEAN TOWARD THE WARMER MAV MOS GUIDANCE ESPECIALLY SINCE IN
MOST PLACES IT IS EXPECTED THAT...EVEN WITH LIGHT WINDS...SUFFICIENT
MIXING SHOULD OCCUR TO MIX OUT DEW POINTS SOME. ALREADY IN PARTS OF
THE NORTHWEST PIEDMONT TO THE TRIANGLE...DEW POINTS HAVE FALLEN
BELOW 60F. HIGHS TODAY 85 TO 90.
TONIGHT...CLEAR TO PARTLY CLOUDY WITH THE POTENTIAL FOR SOME LOW
CLOUDS OR MORE LIKELY FOG IN THE LIGHT WIND FIELD LATE PARTICULARLY
WHERE ANY SHOWERS OCCUR. THE BEST POTENTIAL FOR THESE SHOULD BE
TOWARD THE SOUTHEAST WHERE SREF PROBABILITIES OF FOG ARE HIGHEST
RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. WILL NOTE PATCHY FOG
IN THE GRIDDED AND WORDED FORECASTS THERE. OVERNIGHT LOWS AROUND 60
TO THE MID 60S.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 300 AM SUNDAY...
SIMILAR CONDITIONS TO TODAY...SUNDAY...ARE EXPECTED MONDAY AND
MONDAY NIGHT WITH HIGHER PRECIPITABLE WATER VALUES CONTINUING OVER
ABOUT THE SOUTHERN TWO TIERS OF COUNTIES IN CENTRAL NORTH
CAROLINA...BETTER LIFT FORECAST IN THE AFTERNOON AND EARLY
EVENING...AND GREATER INSTABILITY COMPARED TO THE REST OF THE AREA.
IN FACT...THE GFS AND NAM MODELS BOTH FORECAST A SLIGHT INCREASE IN
INSTABILITY IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN MONDAY...
WITH LIFTED INDICES APPROACHING -5C IN THE AFTERNOON AND MLCAPE IN
THE LOWEST KM AS HIGH AS JUST OVER 1000J/KG. DOWNDRAFT CAPE IS ALSO
GREATER ON THE GFS WITH SLIGHTLY BETTER 1000-500MB LAPSE RATES...
CLOSER TO 6.5C/KM. THE BUFR SOUNDING FROM THE NAM TOWARD KFAY IS
MORE UNSTABLE MONDAY COMPARED TO SUNDAY...WHILE THE GFS BUFR
SOUNDING HAS JUST A SLIGHTLY BETTER CAP BETWEEN 700MB AND 850MB.
GUIDANCE POPS AND QPF ARE ONCE AGAIN VERY SIMILAR ON THE NAM AND THE
GFS...AND WILL NOTE THE POTENTIAL FOR ISOLATED-TO-SCATTERED
AFTERNOON AND EARLY EVENING SHOWERS AND THUNDERSTORMS IN AN AREA
VERY SIMILAR TO THAT FORECAST TODAY...EXCEPT EXPANDED WEST AND NORTH
EVER SO SLIGHTLY. BUFR SOUNDINGS TOWARD THE TRIAD AND KRDU STILL
SEEM A LITTLE TOO STABLE FOR DEEP CONVECTION. WILL CURRENTLY REFRAIN
FROM THE MENTION OF ANY STRONG STORMS FOR NOW IN THE HWO SO AS TO
MONITOR INSTABILITY AND MOISTURE TRENDS...AND AS ANY DEEP CONVECTION
SHOULD STILL BE FAIRLY UNORGANIZED.
1000-850MB THICKNESSES ARE WARMER MONDAY COMPARED TO TODAY AS
HEIGHTS ALOFT RISE...ENOUGH FOR HIGHS ABOUT TWO OR THREE DEGREES
WARMER MONDAY. OVERNIGHT MONDAY...WILL AGAIN NOTE THE POTENTIAL FOR
PATCHY FOG LATE...MAINLY SOUTH...IN A CONTINUED FAIRLY LIGHT WIND
FIELD. THIS IS SIMILAR TO THE SREF ORIENTATION OF LOW VISIBILITY
PROBABILITIES IN CENTRAL NORTH CAROLINA LATE MONDAY NIGHT. LOWS
MONDAY NIGHT MOSTLY LOWER TO MID 60S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...
TUESDAY AND WEDNESDAY: THIS PERIOD WILL START WITH RIDGING ALOFT AND
A BERMUDA HIGH OFF THE COAST...RESULTING IN WARM MOIST RETURN FLOW
INTO THE AREA. THE APPROACHING COLD FRONT WILL HELP PUSH THE RIDGE
OUT OF THE AREA LATE WEDNESDAY...WITH CONTINUED SOUTHERLY FLOW. THE
INCREASING TEMPERATURES AND MOISTURE WILL RESULT IN THE CHANCE FOR
MAINLY SCATTERED DIURNAL SHOWERS AND STORMS TO DEVELOP...ALTHOUGH
WITH THE LACK OF UPPER LEVEL FORCING...THE CHANCE OF SEVERE STORMS
CONTINUES TO BE LOW. OTHERWISE...EXPECT MAINLY DRY CONDITIONS. HIGHS
GREATEST ON TUESDAY...UPPER 80S TO AROUND 90 DEGREES...DECREASING
SLIGHTLY FOR WEDNESDAY...IN THE MID TO UPPER 80S. OVERNIGHT LOWS IN
THE MID 60S.
WEDNESDAY NIGHT THROUGH SATURDAY: THOUGH THERE ARE STILL TIMING
DIFFERENCES BETWEEN THE MODELS WITH THE APPROACHING LOW PRESSURE
SYSTEM AND ASSOCIATED COLD FRONT...THEY HAVE COME INTO BETTER
AGREEMENT OVER THE PAST FEW MODEL RUNS. THE LATEST MODEL RUNS
INDICATE THE BEST CHANCES FOR SHOWERS AND STORMS ON THURSDAY AFT/EVE
AS THE FRONT BEGINS PUSHING THROUGH THE AREA. CONFIDENCE IS
GRADUALLY INCREASING. EXPECT THE SHEAR AND INSTABILITY TO INCREASE
AS THE FRONT APPROACHES...AND WITH THE FORCING PRESENT...THE THREAT
FOR STRONG TO SEVERE STORMS EXISTS...WITH THE BEST POTENTIAL
INDICATED IN THE SANDHILLS AND COASTAL PLAIN. THERE IS STILL SOME
UNCERTAINTY REGARDING STORM INTENSITY AT THIS TIME GIVEN THE
DEPENDENCE ON FROPA TIMING AND THE MODEL DIFFERENCES IN THAT
REGARD...SO WILL CONTINUE TO MONITOR THE EVOLUTION OF THIS SYSTEM
AND WILL KEEP THE CURRENT WORDING IN THE HWO. EXPECT SHOWER AND
THUNDERSTORM CHANCES TO TAPER OFF BEHIND THE FRONT. TEMPERATURES
WILL DECREASE THROUGH THE PERIOD. HIGHS IN THE MID 70S TO LOW 80S
THURSDAY DOWN TO LOW/MID 70S SATURDAY. LOWS IN THE MID 50S TO AROUND
60 DEGREES THURSDAY NIGHT DOWN TO THE LOW TO MID 50S TO START THE
WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 205 AM SUNDAY...
VFR CONDITIONS WILL BE THE RULE THROUGH THE 06Z VALID TAF PERIOD.
EXPECT A FEW LOCATIONS TO EXPERIENCE MVFR CONDITIONS EARLY THIS
MORNING...WITH THE HIGHER PROBABILITIES OF SUCH CONDITIONS...
POSSIBLY EVEN IFR BRIEFLY...TOWARD THE TRIAD WHERE THE MOST RAIN
OCCURRED IN CENTRAL NORTH CAROLINA SATURDAY. DURING THIS AFTERNOON
TOWARD KFAY...TO JUST EAST OF KRWI...ANTICIPATE ISOLATED-TO-
SCATTERED SHOWERS AND A THUNDERSTORM OR TWO IN BETTER MOISTURE AND
INSTABILITY. ANY SHOWERS SHOULD DIMINISH QUICKLY WITH THE APPROACH
OF SUNSET AND THE LOSS OF DAYTIME HEATING. WHILE BOUNDARY LAYER
WINDS ARE LIGHT...BOTH THE GFS AND NAM GUIDANCE SUGGESTS SURFACE
WINDS VEERING THIS MORNING AND THEN BECOMING ABRUPTLY SOUTHERLY
OVERALL BY LATE TODAY.
BEYOND THE 06Z VALID TAF PERIOD...DURING THE WEEK THERE SHOULD BE
INCREASING PROBABILITIES EACH DAY FOR LATE NIGHT AND EARLY MORNING
LOW CLOUDS AND/OR FOG. MONDAY MORNING AND AGAIN TUESDAY MORNING IT
WOULD SEEM THE BETTER CHANCES OF SUCH WILL BE WHERE ANY AFTERNOON
SHOWERS OCCUR...SUCH AS TOWARD KFAY AND POSSIBLY KRWI. TUESDAY
THROUGH THURSDAY THE CHANCES FOR SHOWERS AND THUNDERSTORMS GRADUALLY
INCREASE AND SPREAD FROM WEST-TO-EAST ACROSS CENTRAL NORTH CAROLINA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...KCP
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
145 AM EDT SUN MAY 11 2014
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL MAINTAIN WARM TEMPERATURES THROUGH
THE MIDDLE OF THE UPCOMING WEEK. A CHANCE OF RAIN WILL ARRIVE LATE
IN THE WEEK AS A COLD FRONT CROSSES THE COAST ON FRIDAY. COOLER
TEMPERATURES WILL PREVAIL INTO NEXT WEEKEND IN WAKE OF THE FRONT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1045 PM SATURDAY...CONVECTION UPSTREAM CONTINUES TO WANE
ESPECIALLY COMPARED TO JUST PRIOR TO SUNSET. TWO UPSTREAM 5H
VORTS IE. S/W TROFS...TO PASS IN CLOSE PROXIMITY OVERNIGHT INTO
SUNDAY. 1 REMAINS NORTH OF THE FA...TRACKING OFF THE DELMARVA
COAST BY DAYBREAK SUN. THE OTHER MOVES ACROSS THE NE GULF COAST
STATES OVERNIGHT...AND OFF THE GA COAST AFTER DAYBREAK SUNDAY. THE
BEST CONVECTION CHANCES WILL LIE ALONG AND JUST AHEAD OF THESE
MID-LEVEL FEATURES. AS FOR THE ILM CWA...CONVECTION HAS FALLEN
BELOW SLIGHT CHANCE AT THE MOMENT AND SHOULD REMAIN-SO FOR THE
REMAINDER OF THE NIGHT. SFC CONVERGENCE ZONES...IE THE SEA
BREEZE...WILL FADE AWAY FROM THE LOSS OF DAYTIME INSOLATION.
OUTFLOW BOUNDARIES FROM EARLIER CONVECTION COULD CREEP ACROSS THE
ILM CWA...HOWEVER THE BEST FORCING FOR OVERNITE CONVECTION IS
PROGGED TO REMAIN NORTH AND SOUTH OF THE FORECAST AREA. AND
FINALLY...THE FORWARD PUSH OF THE SFC COLD FRONT IS PROGGED TO
CEASE WELL BEFORE REACHING THE ILM CWA OVERNIGHT. TWEAKED THE
OVERNIGHT MIN TEMPS BY 1 TO POSSIBLY 2 DEGREES ESPECIALLY AREAS
DUE TO THE LIKELIHOOD OF MORE EXTENSIVE/DEEPER LEFTOVER CLOUDINESS
AND LOCAL WINDS STAYING ACTIVE...ESPECIALLY THE COASTAL COUNTIES.
PREVIOUS DISCUSSION.................................
AS OF 300 PM SATURDAY...ACTUAL AND MODEL SOUNDINGS SHOW VERY
DRY MID LEVELS THAT WILL CONTINUE TO INHIBIT CONVECTION THROUGH
THE DAYLIGHT HOURS AND INTO THE EVENING...ESPECIALLY AS ONE NEARS
THE COAST. FURTHER INLAND THE COLUMN IS A BIT MOISTER AND THE
ISOLATED SHOWER OR THUNDERSTORM CANNOT BE RULED OUT FOR THE
REMAINDER OF THIS AFTERNOON AND INTO THE EVENING. HAVE NOT CHANGED
THE GOING FORECAST TOO MUCH IN THIS REGARD...WITH ONLY SLIGHT
CHANCE POPS UNTIL AROUND MIDNIGHT. LATEST GUIDANCE DOES INCREASE
MOISTURE ADVECTION AFTER MIDNIGHT...BUT ALSO BEGINS TO REBUILD THE
UPPER RIDGE. ASSOCIATED SUBSIDENCE WHEN COMBINED WITH LOSS OF
HEATING MEANS THAT WE WILL STAY DRY AFTER MIDNIGHT.
GUIDANCE HAS BEEN CONSISTENTLY TOO COOL BY SEVERAL OR MORE DEGREES
FOR OUR OVERNIGHT TEMPERATURES. HAVE TAKEN THE GUIDANCE WITH THE
WARMEST FORECAST...THE NAM MOS...AND BUMPED THOSE NUMBERS UP BY A
DEGREE OR SO. THIS WILL GIVE US LOWS IN THE UPPER 60S. THIS IS A
SHADE LOWER THAN LAST NIGHT...WHICH MAKES SENSE AS ONGOING SWLY
LOW LEVEL FLOW WILL WEAKEN SOMEWHAT OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...SUMMER-LIKE PATTERN TO REDEVELOP AS
BERMUDA-TYPE HIGH PERSISTS OFFSHORE AND AN AMPLIFYING UPPER RIDGE
RE-ASSERTS ITSELF ACROSS THE SOUTHEAST. THESE TWO FEATURES IN
TANDEM WILL DRIVE TEMPERATURES ONCE AGAIN TO WELL ABOVE NORMAL
VALUES FOR THE EARLY PART OF THE WEEK...WITH HIGHS AROUND 90
INLAND BOTH DAYS...MID 80S AT THE COAST...AND AROUND 80 ON THE
BEACHES. MONDAY WILL BE THE WARMER OF THE TWO DAYS. LOWS BOTH
NIGHTS WILL ALSO BE WELL ABOVE NORMAL...FALLING ONLY INTO THE
MID 60S...AROUND 70 MONDAY NIGHT NEAR THE BEACHES.
THE MORE DIFFICULT PART OF THE FORECAST INVOLVES CONVECTIVE
POTENTIAL BOTH DAYS. SPC HAS A GENERAL RISK IN THE SWODY2 AND
SWODY3 OUTLOOKS FOR THE SOUTHEAST. ON SUNDAY...LOW LEVEL
MOISTURE PERSISTS BELOW 600MB INTO THE AFTN...BUT THIS OCCURS
WHILE THE RIDGE AXIS BUILDS TO THE WEST...CREATING DRYING NW FLOW
ABOVE 800MB. THIS SUGGESTS THAT HEATING OF THE DAY WHICH COULD
FUEL TSTMS...WILL BE RACING AGAINST INCREASINGLY DRY MID-LEVEL
AIR WHICH WOULD PREVENT CONVECTION. ATTM EXPECT THE SEA BREEZE
BOUNDARY WILL BE THE POTENTIAL FOCUS FOR CONVECTION ON
SUNDAY...AND WILL CARRY ONLY ISOLATED TSTMS. BY MONDAY...THE 5H
RIDGE PEAKS OVERHEAD...AND THIS SHOULD PUT A LID ON CONVECTION.
FORECAST SOUNDINGS SHOW VERY DRY AIR ABOVE 900MB...AND SURFACE
PARCELS WILL ENCOUNTER SOME CIN AS THE THERMAL RIDGE EXPANDS
OVERHEAD. FOR THIS REASON BELIEVE THERE WILL BE NO TSTMS ON
MONDAY...AND WILL KEEP POP SILENT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...MID LEVEL HIGH PRESSURE WILL DOMINATE THE
FIRST TWO DAYS OF THE FORECAST PROVIDING A CONTINUATION OF ABOVE
NORMAL TEMPERATURES AND MINIMAL CHANCES FOR CONVECTION.FOR
POPS...WILL MAINTAIN THE INLAND SEA BREEZE AREAS FOR TUESDAY AND
THE SLIGHT TRANSITION TO WESTERN COUNTIES FOR WEDNESDAY. AS THE
RIDGE FINALLY BREAKS DOWN WITH A PHASING MID LEVEL TROUGH TO THE
WEST...PRECIPITABLE WATERS AND COOLING MID LEVELS WILL MAKE
CONVECTION MORE LIKELY THURSDAY AND PART OF THE DAY FRIDAY. THE
NEW FORECAST DAY...SATURDAY LOOKS DRIER AND COOLER AS THE TROUGH
IS SUFFICIENTLY POTENT TO PUSH THE FRONT OFFSHORE. NO CHANGES TO
THE TEMPERATURE FORECAST THE PREVIOUS DAYS.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...RADAR IMAGERY SHOWS SOME SHOWERS OVER SOUTH CAROLINA
ASSOCIATED WITH AN UPPER DISTURBANCE. THE LATEST HRRR RUNS DISSIPATE
MUCH OF THIS ACTIVITY BEFORE IT REACHES NC. PERIODS OF MVFR/IFR
CIGS/VSBYS IN THE EARLY MORNING HOURS...AS THIS MOIST LOW LEVEL
ENVIRONMENT HAS PROVEN TO BE CONDUCIVE FOR FOG/STRATUS. GUIDANCE
FAVORS IFR STRATUS AND REDUCED VSBYS AT KFLO/KLBT. TEMPO IFR
CIGS/VSBYS CANNOT BE RULED OUT ALONG THE COAST AS WELL. ISOLATED
CONVECTION IS POSSIBLE LATER TODAY WITH SURFACE HEATING AS THE LOW
LEVELS MOISTEN. THE SEA BREEZE WOULD LIKELY BE THE FOCUS FOR ANY
SHOWER ACTIVITY...WITH THE BEST CHANCES AT THE INLAND TERMINALS
LATER THIS AFTERNOON. WILL MAINTAIN VCSH ATTM SINCE COVERAGE WILL
BE SPOTTY AT BEST. SOUTHWEST WINDS 5-10 KTS WILL BECOME SOUTH
AROUND 10 KTS IN THE AFTERNOON AS THE SEA BREEZE PUSHES INLAND.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM SATURDAY...SFC HIGH PRESSURE CENTERED EAST AND
OFFSHORE FROM THE CAROLINA COASTS...WILL CONTINUE TO RIDGE BACK
WESTWARD ACROSS THE AREA WATERS OVERNIGHT AND INTO THE SHORT TERM
PERIOD. THE APPROACHING AND NOW WEAK COLD FRONT DROPPING DOWN FROM
THE NW-N WILL BECOME STATIONARY AND REMAIN INLAND...AND IS
PROGGED NOT TO REACH THE ILM COASTAL WATERS AS THE RIDGING FROM
THE OFFSHORE WATERS REMAINS TOO STRONG TO BUDGE. HAVE GONE WITH
S TO SSW WINDS BECOMING SW-WSW AT 10-15 KT WITH CONTINUED GUSTS
20+...MAINLY ALONG THE NEARSHORE WATERS DUE TO THE SLOW DECAY OF
THE SEA-BREEZE CIRCULATION. SIGNIFICANT SEAS WILL BE GOVERNED BY
THE LOCALLY PRODUCED 2 TO 4 FOOT WIND DRIVEN WAVES/CHOP...
EXHIBITING 3 TO 6 SECOND PERIODS.
PREVIOUS DISCUSSION..................................
AS OF 300 PM SATURDAY...PERSISTENT SOUTHWESTERLY FLOW AROUND THE
BACKSIDE OF A BERMUDA-STYLE HIGH WILL KEEP WINDS IN THE 10 TO 15
KT RANGE FOR MOST OF THE WATERS THROUGH THE NEAR TERM...WITH THE
EXCEPTION OF NEAR THE COAST THIS AFTERNOON AND EVENING. ALONG THE
COAST AN ENHANCED SEA BREEZE CIRCULATION IS KEEPING WINDS ELEVATED
AT 15 TO 20 KTS WITH GUSTS TO 25 KTS. THESE WINDS WILL SUBSIDE
LATER THIS EVENING. SEAS WILL STAY IN THE 2 TO 3 FT RANGE THROUGH
THE NEAR TERM.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...SUMMER LIKE SETUP FOR THE SHORT TERM AS
BERMUDA HIGH PRESSURE SPINS OFFSHORE. THIS WILL PUMP SW RETURN FLOW
ACROSS THE WATERS THROUGH THE PERIOD...CREATING WINDS OF 10-15 KTS
THROUGH THE PERIOD...WITH LITTLE FLUCTUATION IN STRENGTH OR
DIRECTION EITHER DAY. THESE WINDS PLUS THE PERSISTENT FETCH AROUND
THE OFFSHORE HIGH PRESSURE WILL CREATE 2-3 FT SEAS EACH DAY...WITH A
WAVE SPECTRUM COMPRISED OF A SOUTHERLY 4-5 SEC WIND WAVE AND A
LOW-AMPLITUDE SE GROUND SWELL.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM SATURDAY...SOUTHEAST FLOW WITH BERMUDA HIGH PRESSURE
WILL PREVAIL ACROSS THE COASTAL WATERS THROUGH THE PERIOD. WIND
SPEEDS OF 10-15 KNOTS CAN BE EXPECTED FOR THE MOST PART WITH
POSSIBLY A FEW HOURS OF HIGHER SPEEDS VIA THE SEA BREEZE. SEAS
WILL REMAIN REPRESENTATIVE OF THE SUMMERTIME PATTERN WITH 2-3
FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/8
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...BJR/8
AREA FORECAST DISCUSSION
NWS BISMARCK ND
936 PM CDT MON MAY 12 2014
.UPDATE...
ISSUED AT 934 PM CDT MON MAY 12 2014
NO SIGNIFICANT CHANGES FOR LATE EVENING UPDATE OTHER THAN TRIM LOW
POPS FROM THE FAR SOUTHEAST.
UPDATE ISSUED AT 700 PM CDT MON MAY 12 2014
EARLY EVENING UPDATE TO EXPIRE WIND ADVISORY AS WINDS WILL
CONTINUE TO GRADUALLY DIMINISH DURING THE EARLY EVENING. THE FAR
SOUTHEAST FRINGE MAY SEE SOME LINGERING SHOWERS THROUGH MID TO
LATE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 329 PM CDT MON MAY 12 2014
MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE WINDS ACROSS
THE AREA THROUGH THE REMAINDER OF THE AFTERNOON...PRECIPITATION
ENDING IN THE EAST THIS EVENING AND OVERNIGHT TEMPERATURES.
CURRENTLY...SURFACE LOW PRESSURE OVER SOUTHEAST MINNESOTA WITH AN
INVERTED TROUGH NORTH THROUGH NORTHERN MINNESOTA. THE DEFORMATION
ZONE ASSOCIATED WITH THIS LOW PRESSURE SYSTEM WILL CONTINUE TO
TRACK EAST THIS EVENING AND RAIN SHOWERS WILL END OVER THE JAMES
RIVER VALLEY THIS EVENING.
LATEST RAP SOUNDINGS INDICATE THAT AREAS ALONG AND WEST OF
HIGHWAY 83 WILL SEE DIMINISHING WINDS THIS EVENING. IT MAY BE
BREEZY THROUGH AROUND 9 PM BUT WINDS SHOULD REMAIN BELOW ADVISORY
LEVELS. WINDS COULD HOLD ON OVER EASTERN PORTIONS OF CENTRAL NORTH
DAKOTA WITH KJMS AND CARRINGTON 19 UTC BUFR SOUNDINGS INDICATING
THE BOUNDARY LAYER REMAINING LIFTED WITH 40 KNOT WINDS AVAILABLE
TO WORK DOWN. GRADIENT WINDS WILL BE STRONGEST HERE ALSO...CLOSER
TO THE SURFACE LOW. WILL KEEP THE ADVISORY GOING AND EVENING SHIFT
WILL NEED TO LOOK INTO POSSIBLY EXTENDING EASTERN PORTIONS OF THE
ADVISORY.
CONVECTIVE CUMULUS FLATTENING OUT SHOULD SLOWLY DISSIPATE THIS
EVENING. THUS MOSTLY CLEAR SKIES ARE EXPECTED BY MORNING. WILL SEE
LOWS IN THE LOW TO MID 30S MOST AREAS. WINDS SHOULD REMAIN AT 5 TO
10 MPH OVERNIGHT...KEEPING TEMPERATURES FROM FALLING INTO THE
20S. MID 30S ARE EXPECTED OVER EASTERN PORTIONS OF CENTRAL NORTH
DAKOTA WHERE WINDS AND CLOUDS HANG ON LONGER TONIGHT.
TUESDAY WILL BE MUCH NICER THAN TODAY OVER THE JAMES RIVER
VALLEY...WITH NO RAIN...LESS WIND AND MORE SUN. ELSEWHERE...TUESDAY
IS EXPECTED TO SIMILAR TO TODAY...BUT WITH A LITTLE LESS CLOUDS
AND WINDS AND A LITTLE MORE SUNSHINE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 329 PM CDT MON MAY 12 2014
TROUGH MOVES EAST WEDNESDAY WITH NORTHWEST FLOW ALOFT DEVELOPING AND
PERSISTING THROUGH THE FIRST HALF OF NEXT WEEKEND. EMBEDDED WAVE IS
DEPICTED TO MOVE THROUGH SOMETIME THURSDAY NIGHT OR FRIDAY BRINGING
A CHANCE FOR SHOWERS TO THE LOCAL AREA. OTHERWISE THE REST OF THE
WORK WEEK APPEARS MAINLY DRY.
12Z GFS/ECMWF SHOW A SHORT WAVE RIDGE SATURDAY NIGHT FOLLOWED BY A
MORE ACTIVE FLOW SUNDAY INTO MONDAY AHEAD AND ALONG A DEVELOPING
TROUGH ORIGINATING OVER THE PACIFIC NORTHWEST AND PROGRESSING
EASTWARD. MILDER TEMPERATURES OVER THE WEEKEND AS WELL...HELPING TO
INCREASE THE POTENTIAL FOR THUNDERSTORMS SUNDAY-MONDAY. UNCERTAINTY
STILL HIGH SO WILL LEAVE OUT OF THE FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 700 PM CDT MON MAY 12 2014
EXPECT A DIMINISHING NORTHERLY WIND OVERNIGHT WITH DECREASING
CLOUDS AND VFR CONDITIONS THROUGH THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...TWH
LONG TERM...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
718 PM CDT MON MAY 12 2014
.UPDATE...
ISSUED AT 700 PM CDT MON MAY 12 2014
EARLY EVENING UPDATE TO EXPIRE WIND ADVISORY AS WINDS WILL
CONTINUE TO GRADUALLY DIMINISH DURING THE EARLY EVENING. THE FAR
SOUTHEAST FRINGE MAY SEE SOME LINGERING SHOWERS THROUGH MID TO
LATE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 329 PM CDT MON MAY 12 2014
MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE WINDS ACROSS
THE AREA THROUGH THE REMAINDER OF THE AFTERNOON...PRECIPITATION
ENDING IN THE EAST THIS EVENING AND OVERNIGHT TEMPERATURES.
CURRENTLY...SURFACE LOW PRESSURE OVER SOUTHEAST MINNESOTA WITH AN
INVERTED TROUGH NORTH THROUGH NORTHERN MINNESOTA. THE DEFORMATION
ZONE ASSOCIATED WITH THIS LOW PRESSURE SYSTEM WILL CONTINUE TO
TRACK EAST THIS EVENING AND RAIN SHOWERS WILL END OVER THE JAMES
RIVER VALLEY THIS EVENING.
LATEST RAP SOUNDINGS INDICATE THAT AREAS ALONG AND WEST OF
HIGHWAY 83 WILL SEE DIMINISHING WINDS THIS EVENING. IT MAY BE
BREEZY THROUGH AROUND 9 PM BUT WINDS SHOULD REMAIN BELOW ADVISORY
LEVELS. WINDS COULD HOLD ON OVER EASTERN PORTIONS OF CENTRAL NORTH
DAKOTA WITH KJMS AND CARRINGTON 19 UTC BUFR SOUNDINGS INDICATING
THE BOUNDARY LAYER REMAINING LIFTED WITH 40 KNOT WINDS AVAILABLE
TO WORK DOWN. GRADIENT WINDS WILL BE STRONGEST HERE ALSO...CLOSER
TO THE SURFACE LOW. WILL KEEP THE ADVISORY GOING AND EVENING SHIFT
WILL NEED TO LOOK INTO POSSIBLY EXTENDING EASTERN PORTIONS OF THE
ADVISORY.
CONVECTIVE CUMULUS FLATTENING OUT SHOULD SLOWLY DISSIPATE THIS
EVENING. THUS MOSTLY CLEAR SKIES ARE EXPECTED BY MORNING. WILL SEE
LOWS IN THE LOW TO MID 30S MOST AREAS. WINDS SHOULD REMAIN AT 5 TO
10 MPH OVERNIGHT...KEEPING TEMPERATURES FROM FALLING INTO THE
20S. MID 30S ARE EXPECTED OVER EASTERN PORTIONS OF CENTRAL NORTH
DAKOTA WHERE WINDS AND CLOUDS HANG ON LONGER TONIGHT.
TUESDAY WILL BE MUCH NICER THAN TODAY OVER THE JAMES RIVER
VALLEY...WITH NO RAIN...LESS WIND AND MORE SUN. ELSEWHERE...TUESDAY
IS EXPECTED TO SIMILAR TO TODAY...BUT WITH A LITTLE LESS CLOUDS
AND WINDS AND A LITTLE MORE SUNSHINE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 329 PM CDT MON MAY 12 2014
TROUGH MOVES EAST WEDNESDAY WITH NORTHWEST FLOW ALOFT DEVELOPING AND
PERSISTING THROUGH THE FIRST HALF OF NEXT WEEKEND. EMBEDDED WAVE IS
DEPICTED TO MOVE THROUGH SOMETIME THURSDAY NIGHT OR FRIDAY BRINGING
A CHANCE FOR SHOWERS TO THE LOCAL AREA. OTHERWISE THE REST OF THE
WORK WEEK APPEARS MAINLY DRY.
12Z GFS/ECMWF SHOW A SHORT WAVE RIDGE SATURDAY NIGHT FOLLOWED BY A
MORE ACTIVE FLOW SUNDAY INTO MONDAY AHEAD AND ALONG A DEVELOPING
TROUGH ORIGINATING OVER THE PACIFIC NORTHWEST AND PROGRESSING
EASTWARD. MILDER TEMPERATURES OVER THE WEEKEND AS WELL...HELPING TO
INCREASE THE POTENTIAL FOR THUNDERSTORMS SUNDAY-MONDAY. UNCERTAINTY
STILL HIGH SO WILL LEAVE OUT OF THE FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 700 PM CDT MON MAY 12 2014
EXPECT A DIMINISHING NORTHERLY WIND OVERNIGHT WITH DECREASING
CLOUDS AND VFR CONDITIONS THROUGH THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...TWH
LONG TERM...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
116 PM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 116 PM CDT SUN MAY 11 2014
LINGERING SHOWERS OVER THE NORTH CENTRAL CONTINUE TO LIFT NORTH
AND SHRINK IN AREAL COVERAGE. SHOWERS MOVING NORTH THROUGH SOUTH
DAKOTA WILL LIKELY NOT REACH THE FAR SOUTH UNTIL LATE AFTERNOON
AND HAVE TRIMMED BACK POPS OVER THE FAR SOUTH CENTRAL INTO THE
SOUTHERN JAMES RIVER VALLEY. CLOUDS HAD CLEARED OVER THE NORTHWEST
BRIEFLY BUT CUMULUS HAVE NOW FORMED. EXPECT A DECREASE IN
CUMULUS COVERAGE THROUGH THE REMAINDER OF THE AFTERNOON OVER THE
NORTHWEST AND FAR WEST CENTRAL. MOST AREAS REMAIN CLOUDY AND HAVE
CUT BACK ON HIGH TEMPERATURES ACCORDINGLY. MAINLY MID TO UPPER 40S
SOUTHWEST THROUGH NORTH CENTRAL...WITH A FEW 50S FAR SOUTHEAST AND
FAR NORTHWEST.
UPDATE ISSUED AT 1035 AM CDT SUN MAY 11 2014
WEAK UPPER LEVEL IMPULSE IS RESPONSIBLE FOR AN AREA OF SHOWERS
FROM MINOT AND MOHALL NORTHEAST THROUGH WESTHOPE AND BOTTINEAU.
THE AREA HAS MOVED LITTLE THE PAST FEW HOURS...BUT CONTINUES TO
SHRINK IN AREAL COVERAGE. WILL KEEP HIGH POPS IN THIS AREA THROUGH
THE MORNING WITH DECREASING POPS BY EARLY AFTERNOON. ANOTHER AREA
OF SHOWERS ASSOCIATED WITH A CENTRAL PLAINS STORM SYSTEM CONTINUES
TO LIFT NORTH TOWARD SOUTHERN NORTH DAKOTA. HOWEVER...PROGRESS HAS
SLOWED AND WILL REMOVE MENTION OF PRECIPITATION THIS MORNING OVER
THE FAR SOUTH CENTRAL INTO THE JAMES RIVER BASIN...WITH INCREASING
POPS DURING THE AFTERNOON.
RAISED SKY COVER MOST AREAS THIS MORNING...KEEPING OVERCAST SKIES
CENTRAL AND SOUTHWEST THROUGH THE DAY. ALSO RAISED WINDS TODAY
CENTRAL AND SOUTHWEST. LATEST 13 UTC RAP INDICATES 25-30 KNOT
WINDS POTENTIALLY WORKING DOWN TO THE SURFACE THIS AFTERNOON. THIS
WOULD BE NEAR ADVISORY CRITERIA. WILL MONITOR WINDS BUT HOLD OFF
ON ANY ADVISORY FOR NOW.
UPDATE ISSUED AT 654 AM CDT SUN MAY 11 2014
UPDATED THE FORECAST TO INCREASE MORNING POPS OVER NORTH CENTRAL
NORTH DAKOTA WHERE THE LATEST RADAR/SURFACE OBS INDICATED ONGOING
RAIN SHOWER ACTIVITY. ALSO DECREASED POPS SOUTHWEST BASED ON
LATEST RADAR TRENDS. THE LATEST HRRR PROGS RAIN SHOWER ACTIVITY
OVER NORTHERN NORTH DAKOTA TO DIMINISH THIS AFTERNOON WITH RAIN
SHOWERS DEVELOPING OVER THE SOUTHERN JAMES RIVER BASIN THIS
AFTERNOON. GENERALLY FOLLOWED THE HRRR PROG WITH RESPECT TO POP
TRENDS TODAY. OTHERWISE...THE REMAINING WEATHER ELEMENTS ARE IN
GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT SUN MAY 11 2014
THE FOCUS IN THE SHORT TERM IS ON THE PROGRESSION OF PRECIPITATION
THROUGH TONIGHT.
LATEST REFLECTIVITY SHOWS THE MAJORITY OF PRECIPITATION OVER NORTH
CENTRAL NORTH DAKOTA. THE 00 UTC WRF AND LATEST HRRR RUNS HAVE
VERIFIED PRETTY WELL WITH CURRENT OBSERVATIONS. ON THE OTHER HAND
THE 00 UTC RUNS OF THE GFS...NAM...ECMWF...AND NHEM GEM HAD A
DIFFICULT TIME NAILING DOWN THE PRECIPITATION OVER THE NORTH CENTRAL
AND ALL OVERPLAYED THE WRAP AROUND PRECIPITATION LOCATED OVER
EASTERN MONTANA AND WESTERN NORTH DAKOTA. WITH THAT SAID USED THE
HRRR AND 00 UTC WRF RUN FOR POPS THROUGH 12 UTC SUNDAY THEN A MODEL
BLEND FROM 12 UTC SUNDAY THROUGH 12 UTC MONDAY SINCE MODEL AGREEMENT
WAS GOOD ON THE WEST TO EAST PROGRESSION OF PRECIPITATION THROUGH SUNDAY.
AT THIS TIME NO THUNDERSTORM ACTIVITY IS EXPECTED SUNDAY...JUST A
CHILLY RAW DAY. WINDS WILL ALSO BE BREEZY 15 TO 25 MPH FROM THE
NORTHWEST SUSTAINED ACROSS THE WEST AND CENTRAL. NO WIND ADVISORY IS
ANTICIPATED AT THIS TIME.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 11 2014
THE 00Z GFS/GEM/ECMWF PROG AN OPEN WAVE TO MEANDER OVER
SOUTHEASTERN SASKATCHEWAN/WESTERN NORTH DAKOTA MONDAY. THIS WILL
LEAD TO ENHANCED PRECIPITATION CHANCES EAST OF HIGHWAY 83...MAINLY
OVER THE JAMES RIVER BASIN. THE OPEN WAVE IS THEN PROGGED TO
SLOWLY MEANDER EAST...SHIFTING PRECIPITATION CHANCES EAST ALONG
WITH IT. SOME WRAP AROUND MOISTURE WILL GENERATE A SLIGHT CHANCE
OF SHOWERS OVER WESTERN AND CENTRAL NORTH DAKOTA LATE TUESDAY.
HOWEVER...RAINFALL AMOUNTS SHOULD BE VERY LIGHT IF ANY RAIN WERE
TO DEVELOP.
BY WEDNESDAY AND THURSDAY...SYNOPTIC SUBSIDENCE IS PROGGED TO
OVERSPREAD THE STATE AHEAD OF A DEVELOPING PACIFIC RIDGE. THIS
SHOULD LEAD TO MAINLY DRY CONDITIONS WITH HIGHS IN THE UPPER 50S.
THE MEDIUM RANGE MODELS NOW PROG A WEAK WAVE TO TRAVERSE NORTH
DAKOTA FRIDAY/FRIDAY NIGHT. INDICATED SLIGHT CHANCE POPS AS A
RESULT. THE PACIFIC RIDGE IS THEN FORECAST TO TRANSLATE EAST INTO
THE GREAT PLAINS BY SATURDAY. IF THIS VERIFIES...IT SHOULD GENERATE
DRY CONDITIONS AND HIGHS IN THE MID 60S BY THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 117 PM CDT SUN MAY 11 2014
MVFR CEILINGS CONTINUE AT KMOT...KDIK...KBIS AND KJMS. COULD SEE
PERIODS OF LOW VFR CEILINGS LATE THIS AFTERNOON. ANOTHER ROUND OF
RAIN IS EXPECTED TO LIFT INTO EASTERN NORTH DAKOTA LATE THIS
AFTERNOON AND TONIGHT. THIS WILL KEEP MVFR CEILINGS AT KJMS
THROUGH 18Z MONDAY. KBIS WILL LIKELY BE ON THE EDGE WITH CLEARING
SKIES TO THE WEST AND MVFR CEILINGS EAST. LEANED TOWARD
PESSIMISTIC SIDE FOR NOW WITH MVFR CEILINGS THROUGH 14Z MONDAY.
KDIK AND KMOT WILL SEE A MUCH HIGHER PROBABILITY OF VFR CEILINGS
ONCE THE CEILINGS LIFT TO VFR TODAY AS DRIER AIR WILL MOVE INTO
THESE AREAS. KISN WILL REMAIN VFR THROUGH THE TAF PERIOD. MODERATE
NORTH TO NORTHWEST WINDS WILL CONTINUE THROUGH THE
PERIOD...INCREASING TO 20 TO 35 MPH MONDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...MM
LONG TERM...TM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1036 AM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 1035 AM CDT SUN MAY 11 2014
WEAK UPPER LEVEL IMPULSE IS RESPONSIBLE FOR AN AREA OF SHOWERS
FROM MINOT AND MOHALL NORTHEAST THROUGH WESTHOPE AND BOTTINEAU.
THE AREA HAS MOVED LITTLE THE PAST FEW HOURS...BUT CONTINUES TO
SHRINK IN AREAL COVERAGE. WILL KEEP HIGH POPS IN THIS AREA THROUGH
THE MORNING WITH DECREASING POPS BY EARLY AFTERNOON. ANOTHER AREA
OF SHOWERS ASSOCIATED WITH A CENTRAL PLAINS STORM SYSTEM CONTINUES
TO LIFT NORTH TOWARD SOUTHERN NORTH DAKOTA. HOWEVER...PROGRESS HAS
SLOWED AND WILL REMOVE MENTION OF PRECIPITATION THIS MORNING OVER
THE FAR SOUTH CENTRAL INTO THE JAMES RIVER BASIN...WITH INCREASING
POPS DURING THE AFTERNOON.
RAISED SKY COVER MOST AREAS THIS MORNING...KEEPING OVERCAST SKIES
CENTRAL AND SOUTHWEST THROUGH THE DAY. ALSO RAISED WINDS TODAY
CENTRAL AND SOUTHWEST. LATEST 13 UTC RAP INDICATES 25-30 KNOT
WINDS POTENTIALLY WORKING DOWN TO THE SURFACE THIS AFTERNOON. THIS
WOULD BE NEAR ADVISORY CRITERIA. WILL MONITOR WINDS BUT HOLD OFF
ON ANY ADVISORY FOR NOW.
UPDATE ISSUED AT 654 AM CDT SUN MAY 11 2014
UPDATED THE FORECAST TO INCREASE MORNING POPS OVER NORTH CENTRAL
NORTH DAKOTA WHERE THE LATEST RADAR/SURFACE OBS INDICATED ONGOING
RAIN SHOWER ACTIVITY. ALSO DECREASED POPS SOUTHWEST BASED ON
LATEST RADAR TRENDS. THE LATEST HRRR PROGS RAIN SHOWER ACTIVITY
OVER NORTHERN NORTH DAKOTA TO DIMINISH THIS AFTERNOON WITH RAIN
SHOWERS DEVELOPING OVER THE SOUTHERN JAMES RIVER BASIN THIS
AFTERNOON. GENERALLY FOLLOWED THE HRRR PROG WITH RESPECT TO POP
TRENDS TODAY. OTHERWISE...THE REMAINING WEATHER ELEMENTS ARE IN
GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT SUN MAY 11 2014
THE FOCUS IN THE SHORT TERM IS ON THE PROGRESSION OF PRECIPITATION
THROUGH TONIGHT.
LATEST REFLECTIVITY SHOWS THE MAJORITY OF PRECIPITATION OVER NORTH
CENTRAL NORTH DAKOTA. THE 00 UTC WRF AND LATEST HRRR RUNS HAVE
VERIFIED PRETTY WELL WITH CURRENT OBSERVATIONS. ON THE OTHER HAND
THE 00 UTC RUNS OF THE GFS...NAM...ECMWF...AND NHEM GEM HAD A
DIFFICULT TIME NAILING DOWN THE PRECIPITATION OVER THE NORTH CENTRAL
AND ALL OVERPLAYED THE WRAP AROUND PRECIPITATION LOCATED OVER
EASTERN MONTANA AND WESTERN NORTH DAKOTA. WITH THAT SAID USED THE
HRRR AND 00 UTC WRF RUN FOR POPS THROUGH 12 UTC SUNDAY THEN A MODEL
BLEND FROM 12 UTC SUNDAY THROUGH 12 UTC MONDAY SINCE MODEL AGREEMENT
WAS GOOD ON THE WEST TO EAST PROGRESSION OF PRECIPITATION THROUGH SUNDAY.
AT THIS TIME NO THUNDERSTORM ACTIVITY IS EXPECTED SUNDAY...JUST A
CHILLY RAW DAY. WINDS WILL ALSO BE BREEZY 15 TO 25 MPH FROM THE
NORTHWEST SUSTAINED ACROSS THE WEST AND CENTRAL. NO WIND ADVISORY IS
ANTICIPATED AT THIS TIME.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 11 2014
THE 00Z GFS/GEM/ECMWF PROG AN OPEN WAVE TO MEANDER OVER
SOUTHEASTERN SASKATCHEWAN/WESTERN NORTH DAKOTA MONDAY. THIS WILL
LEAD TO ENHANCED PRECIPITATION CHANCES EAST OF HIGHWAY 83...MAINLY
OVER THE JAMES RIVER BASIN. THE OPEN WAVE IS THEN PROGGED TO
SLOWLY MEANDER EAST...SHIFTING PRECIPITATION CHANCES EAST ALONG
WITH IT. SOME WRAP AROUND MOISTURE WILL GENERATE A SLIGHT CHANCE
OF SHOWERS OVER WESTERN AND CENTRAL NORTH DAKOTA LATE TUESDAY.
HOWEVER...RAINFALL AMOUNTS SHOULD BE VERY LIGHT IF ANY RAIN WERE
TO DEVELOP.
BY WEDNESDAY AND THURSDAY...SYNOPTIC SUBSIDENCE IS PROGGED TO
OVERSPREAD THE STATE AHEAD OF A DEVELOPING PACIFIC RIDGE. THIS
SHOULD LEAD TO MAINLY DRY CONDITIONS WITH HIGHS IN THE UPPER 50S.
THE MEDIUM RANGE MODELS NOW PROG A WEAK WAVE TO TRAVERSE NORTH
DAKOTA FRIDAY/FRIDAY NIGHT. INDICATED SLIGHT CHANCE POPS AS A
RESULT. THE PACIFIC RIDGE IS THEN FORECAST TO TRANSLATE EAST INTO
THE GREAT PLAINS BY SATURDAY. IF THIS VERIFIES...IT SHOULD GENERATE
DRY CONDITIONS AND HIGHS IN THE MID 60S BY THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1035 AM CDT SUN MAY 11 2014
WIDESPREAD CLOUD COVER ACROSS MOST OF THE AREA TODAY. MVFR TO
OCCASIONAL IFR CEILINGS AT KDIK THROUGH KMOT...WITH MVFR CEILINGS
AT KBIS AND KJMS. EXPECT CEILINGS TO SLOWLY LIFT THROUGH THE DAY
WITH PERHAPS SOME LOW VFR CEILINGS BY LATE AFTERNOON. AT KISN
WHICH IS ON THE BACK EDGE OF CLOUD COVER IS EXPECTED TO REMAIN
MAINLY VFR TODAY...WITH A POSSIBLE HIGH MVFR CEILING AS CUMULUS
DEVELOPS AND LIFTS LATE THIS MORNING INTO EARLY AFTERNOON. TONIGHT
EXPECT MVFR TO LOW VFR CEILINGS TO CONTINUE WITH THE EXCEPTION OF
KISN WILL REMAIN VFR. SHOWERS WILL LIFT NORTH AND AFFECT KBIS AND
KJMS LATE THIS AFTERNOON THROUGH THIS EVENING. MODERATE TO STRONG
NORTH FLOW WILL CONTINUE THROUGH THE ENTIRE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...MM
LONG TERM...TM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
654 AM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 654 AM CDT SUN MAY 11 2014
UPDATED THE FORECAST TO INCREASE MORNING POPS OVER NORTH CENTRAL
NORTH DAKOTA WHERE THE LATEST RADAR/SURFACE OBS INDICATED ONGOING
RAIN SHOWER ACTIVITY. ALSO DECREASED POPS SOUTHWEST BASED ON
LATEST RADAR TRENDS. THE LATEST HRRR PROGS RAIN SHOWER ACTIVITY
OVER NORTHERN NORTH DAKOTA TO DIMINISH THIS AFTERNOON WITH RAIN
SHOWERS DEVELOPING OVER THE SOUTHERN JAMES RIVER BASIN THIS
AFTERNOON. GENERALLY FOLLOWED THE HRRR PROG WITH RESPECT TO POP
TRENDS TODAY. OTHERWISE...THE REMAINING WEATHER ELEMENTS ARE IN
GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT SUN MAY 11 2014
THE FOCUS IN THE SHORT TERM IS ON THE PROGRESSION OF PRECIPITATION
THROUGH TONIGHT.
LATEST REFLECTIVITY SHOWS THE MAJORITY OF PRECIPITATION OVER NORTH
CENTRAL NORTH DAKOTA. THE 00 UTC WRF AND LATEST HRRR RUNS HAVE
VERIFIED PRETTY WELL WITH CURRENT OBSERVATIONS. ON THE OTHER HAND
THE 00 UTC RUNS OF THE GFS...NAM...ECMWF...AND NHEM GEM HAD A
DIFFICULT TIME NAILING DOWN THE PRECIPITATION OVER THE NORTH CENTRAL
AND ALL OVERPLAYED THE WRAP AROUND PRECIPITATION LOCATED OVER
EASTERN MONTANA AND WESTERN NORTH DAKOTA. WITH THAT SAID USED THE
HRRR AND 00 UTC WRF RUN FOR POPS THROUGH 12 UTC SUNDAY THEN A MODEL
BLEND FROM 12 UTC SUNDAY THROUGH 12 UTC MONDAY SINCE MODEL AGREEMENT
WAS GOOD ON THE WEST TO EAST PROGRESSION OF PRECIPITATION THROUGH SUNDAY.
AT THIS TIME NO THUNDERSTORM ACTIVITY IS EXPECTED SUNDAY...JUST A
CHILLY RAW DAY. WINDS WILL ALSO BE BREEZY 15 TO 25 MPH FROM THE
NORTHWEST SUSTAINED ACROSS THE WEST AND CENTRAL. NO WIND ADVISORY IS
ANTICIPATED AT THIS TIME.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 11 2014
THE 00Z GFS/GEM/ECMWF PROG AN OPEN WAVE TO MEANDER OVER
SOUTHEASTERN SASKATCHEWAN/WESTERN NORTH DAKOTA MONDAY. THIS WILL
LEAD TO ENHANCED PRECIPITATION CHANCES EAST OF HIGHWAY 83...MAINLY
OVER THE JAMES RIVER BASIN. THE OPEN WAVE IS THEN PROGGED TO
SLOWLY MEANDER EAST...SHIFTING PRECIPITATION CHANCES EAST ALONG
WITH IT. SOME WRAP AROUND MOISTURE WILL GENERATE A SLIGHT CHANCE
OF SHOWERS OVER WESTERN AND CENTRAL NORTH DAKOTA LATE TUESDAY.
HOWEVER...RAINFALL AMOUNTS SHOULD BE VERY LIGHT IF ANY RAIN WERE
TO DEVELOP.
BY WEDNESDAY AND THURSDAY...SYNOPTIC SUBSIDENCE IS PROGGED TO
OVERSPREAD THE STATE AHEAD OF A DEVELOPING PACIFIC RIDGE. THIS
SHOULD LEAD TO MAINLY DRY CONDITIONS WITH HIGHS IN THE UPPER 50S.
THE MEDIUM RANGE MODELS NOW PROG A WEAK WAVE TO TRAVERSE NORTH
DAKOTA FRIDAY/FRIDAY NIGHT. INDICATED SLIGHT CHANCE POPS AS A
RESULT. THE PACIFIC RIDGE IS THEN FORECAST TO TRANSLATE EAST INTO
THE GREAT PLAINS BY SATURDAY. IF THIS VERIFIES...IT SHOULD GENERATE
DRY CONDITIONS AND HIGHS IN THE MID 60S BY THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 654 AM CDT SUN MAY 11 2014
SURFACE LOW IS LOCATED IN SOUTHEAST NORTH DAKOTA AND MOVING EAST.
SCATTERED SHOWERS AND LOW CEILINGS ACROSS NORTH DAKOTA WILL CAUSE
IFR TO LOW VFR CONDITIONS THROUGH THE 12 UTC TAF CYCLE. BREEZY
NORTHWEST WINDS SUSTAINED FROM 15 TO 25 MPH AND GUSTING OVER 30
MPH ARE ANTICIPATED THROUGH THE 12 UTC TAF CYCLE FOR ALL OF THE
CENTRAL AND WESTERN NORTH DAKOTA TERMINALS. CONDITIONS WILL
IMPROVE FROM WEST TO EAST TONIGHT INTO TOMORROW MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...MM
LONG TERM...TM
AVIATION...MM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
350 AM CDT SUN MAY 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT SUN MAY 11 2014
THE FOCUS IN THE SHORT TERM IS ON THE PROGRESSION OF PRECIPITATION
THROUGH TONIGHT.
LATEST REFLECTIVITY SHOWS THE MAJORITY OF PRECIPITATION OVER NORTH
CENTRAL NORTH DAKOTA. THE 00 UTC WRF AND LATEST HRRR RUNS HAVE
VERIFIED PRETTY WELL WITH CURRENT OBSERVATIONS. ON THE OTHER HAND
THE 00 UTC RUNS OF THE GFS...NAM...ECMWF...AND NHEM GEM HAD A
DIFFICULT TIME NAILING DOWN THE PRECIPITATION OVER THE NORTH CENTRAL
AND ALL OVERPLAYED THE WRAP AROUND PRECIPITATION LOCATED OVER
EASTERN MONTANA AND WESTERN NORTH DAKOTA. WITH THAT SAID USED THE
HRRR AND 00 UTC WRF RUN FOR POPS THROUGH 12 UTC SUNDAY THEN A MODEL
BLEND FROM 12 UTC SUNDAY THROUGH 12 UTC MONDAY SINCE MODEL AGREEMENT
WAS GOOD ON THE WEST TO EAST PROGRESSION OF PRECIPITATION THROUGH SUNDAY.
AT THIS TIME NO THUNDERSTORM ACTIVITY IS EXPECTED SUNDAY...JUST A
CHILLY RAW DAY. WINDS WILL ALSO BE BREEZY 15 TO 25 MPH FROM THE
NORTHWEST SUSTAINED ACROSS THE WEST AND CENTRAL. NO WIND ADVISORY IS
ANTICIPATED AT THIS TIME.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 11 2014
THE 00Z GFS/GEM/ECMWF PROG AN OPEN WAVE TO MEANDER OVER
SOUTHEASTERN SASKATCHEWAN/WESTERN NORTH DAKOTA MONDAY. THIS WILL
LEAD TO ENHANCED PRECIPITATION CHANCES EAST OF HIGHWAY 83...MAINLY
OVER THE JAMES RIVER BASIN. THE OPEN WAVE IS THEN PROGGED TO
SLOWLY MEANDER EAST...SHIFTING PRECIPITATION CHANCES EAST ALONG
WITH IT. SOME WRAP AROUND MOISTURE WILL GENERATE A SLIGHT CHANCE
OF SHOWERS OVER WESTERN AND CENTRAL NORTH DAKOTA LATE TUESDAY.
HOWEVER...RAINFALL AMOUNTS SHOULD BE VERY LIGHT IF ANY RAIN WERE
TO DEVELOP.
BY WEDNESDAY AND THURSDAY...SYNOPTIC SUBSIDENCE IS PROGGED TO
OVERSPREAD THE STATE AHEAD OF A DEVELOPING PACIFIC RIDGE. THIS
SHOULD LEAD TO MAINLY DRY CONDITIONS WITH HIGHS IN THE UPPER 50S.
THE MEDIUM RANGE MODELS NOW PROG A WEAK WAVE TO TRAVERSE NORTH
DAKOTA FRIDAY/FRIDAY NIGHT. INDICATED SLIGHT CHANCE POPS AS A
RESULT. THE PACIFIC RIDGE IS THEN FORECAST TO TRANSLATE EAST INTO
THE GREAT PLAINS BY SATURDAY. IF THIS VERIFIES...IT SHOULD GENERATE
DRY CONDITIONS AND HIGHS IN THE MID 60S BY THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1235 AM CDT SUN MAY 11 2014
SURFACE LOW IS LOCATED JUST SOUTHEAST OF KJMS. WINDS ON THE BACK
SIDE OF THE LOW PRESSURE SYSTEM WILL BE OUT OF THE NORTHWEST AND
INCREASE THROUGH 00 UTC MONDAY FOR ALL TAF SITES IN CENTRAL AND
WESTERN NORTH DAKOTA. SCATTERED SHOWERS AND LOW CEILINGS ACROSS
NORTH DAKOTA WILL CAUSE IFR TO LOW VFR CONDITIONS THROUGH THE 06
UTC TAF CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MM
LONG TERM...TM
AVIATION...MM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1235 AM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 1235 AM CDT SUN MAY 11 2014
UPDATED POPS TO MATCH LATEST RADAR REFLECTIVITY. THE 00 UTC WRF
AND LATEST HRRR CONTINUE TO SHOW THE MAJORITY OF PRECIPITATION
OVER NORTH CENTRAL NORTH DAKOTA...WITH SOME LIGHT PRECIPITATION
ALONG THE DAKOTA MONTANA BORDER. TOOK OUT THE MENTION OF THUNDER
AS THUNDERSTORM ACTIVITY SEEMS TO HAVE COME TO AN END.
UPDATE ISSUED AT 933 PM CDT SAT MAY 10 2014
LARGE PRECIPITATION REGION ON RADAR ALONG AND NORTH OF OCCLUDED
FRONTAL BOUNDARY ACROSS SOUTHEAST NORTH DAKOTA. UPLIFT OVER THE
FRONT AIDING IN GENERATING SCATTERED THUNDERSTORMS ACROSS THE
JAMES RIVER VALLEY. RAISED POPS ACROSS THE EAST THROUGH NORTH
CENTRAL. THIS AREA WILL PIVOT NORTH AND WEST THEN DIMINISH SUNDAY.
UPDATE ISSUED AT 657 PM CDT SAT MAY 10 2014
AS OF 630 PM CDT THUNDERSTORMS HAVE ENDED OVER THE NORTHWEST. NOW
THE FOCUS WILL BE ON THE WEAK LINE OF THUNDERSTORMS MOVING UP THE
JAMES RIVER VALLEY. THESE STORMS HAVE FORMED NORTH OF THE
OCCLUDED FRONT IN SOUTHEAST NORTH DAKOTA. EXPECT THESE TO BE
ACTIVE FOR A FEW HOURS BUT ALREADY SHOWING SIGNS OF DIMINISHING AS
THEY MOVE AWAY FROM THE BETTER CAPE/MID LEVEL LAPSE RATES ACROSS
THE FAR SOUTHEAST.
UPDATE ISSUED AT 350 PM CDT SAT MAY 10 2014
ADDED THIS UPDATE FOR SCATTERED TO ISOLATED THUNDERSTORMS
NORTHWEST REMAINDER OF THIS AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 233 PM CDT SAT MAY 10 2014
THE MAIN FORECAST ISSUES IN THE SHORT TERM PERIOD ARE PRECIPITATION
TRENDS AND AMOUNTS TONIGHT THROUGH SUNDAY.
IN THE NEAR TERM...SHOWERS ARE MOST WIDESPREAD ACROSS THE JAMES
RIVER VALLEY...THEN STRETCHING WEST ALONG THE I-94 CORRIDOR INTO
THE SOUTHWEST COUNTIES. THE MODEL CONSENSUS...INCLUDING THE HIGH
RESOLUTION HRRR AND WRF...INDICATE THE FOCUS OF THE HEAVIER RAIN
WILL SHIFT INTO THE NORTHWEST AND NORTH CENTRAL COUNTIES LATER
TONIGHT INTO SUNDAY MORNING. LINGERING SHOWERS ARE POSSIBLE ACROSS
THE EAST SUNDAY AFTERNOON. ELEVATED INSTABILITY FAVORS ISOLATED LATE
AFTERNOON/EVENING THUNDERSTORMS MAINLY EAST OF BISMARCK INTO THE
JAMES RIVER VALLEY...BUT NO SEVERE WEATHER IS EXPECTED. FOR
SUNDAY...EXPECT A CHILLY AND RAW DAY...WITH HIGHS IN THE UPPER 40S
TO UPPER 50S...ABOUT 10-15 DEGREES BELOW NORMAL. A NORTHWEST WIND
WILL BE SUSTAINED AT 20 TO 25 MPH AND MAY FLIRT WITH ADVISORY
CRITERIA ACROSS THE FAR SOUTHWEST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 233 PM CDT SAT MAY 10 2014
AN SEMI-ACTIVE AND COOL WEATHER PATTERN WILL BE THE MAIN STORY
THROUGH THE LONG TERM FORECAST PERIOD.
UPPER LEVEL TROUGH OVER THE ROCKIES WILL MOVE SLOWLY EAST INTO
THE CENTRAL CONUS SUNDAY NIGHT INTO MONDAY...THEN OFF TO OUR EAST
TUESDAY FOLLOWED BY A QUASI-ACTIVE NORTHWEST FLOW PATTERN FOR THE
REST OF THE WORK WEEK.
FOR SUNDAY NIGHT-MONDAY...SUBSIDENCE ACROSS THE WESTERN HALF OF
THE STATE WILL DRY THINGS OUT WITH LINGERING MOISTURE EAST ALONG
THE UPPER TROUGH. WITH THE TROUGH SLOW TO MOVE EAST...DIURNALLY
DRIVEN SHOWERS WILL BE POSSIBLE BOTH MONDAY AND TUESDAY. MAY BE
COLD ENOUGH DURING THE OVERNIGHT/MORNING PERIODS FOR A RAIN/SNOW
MIX SOME LOCATIONS.
NORTHWEST FLOW WED-FRI WITH POSSIBLE EMBEDDED WAVES AND THE UPPER
JET ALOFT CONTINUING THE THREAT FOR PERIODS OF LIGHT PRECIPITATION.
TEMPERATURES COOL (HIGHS 40S/50S AND LOWS 30S) THROUGH MID
WEEK...WITH A MODERATION IN TEMPERATURES TOWARDS NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1235 AM CDT SUN MAY 11 2014
SURFACE LOW IS LOCATED JUST SOUTHEAST OF KJMS. WINDS ON THE BACK
SIDE OF THE LOW PRESSURE SYSTEM WILL BE OUT OF THE NORTHWEST AND
INCREASE THROUGH 00 UTC MONDAY FOR ALL TAF SITES IN CENTRAL AND
WESTERN NORTH DAKOTA. SCATTERED SHOWERS AND LOW CEILINGS ACROSS
NORTH DAKOTA WILL CAUSE MVFR TO LOW VFR CONDITIONS THROUGH THE 06
UTC TAF CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MM
LONG TERM...NH
AVIATION...MM
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
645 PM EDT SUN MAY 11 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA TONIGHT AS LOW PRESSURE
OVER THE PLAINS TRACKS NORTHEAST INTO THE UPPER MIDWEST. THE LOW
WILL CONTINUE NORTHEAST INTO ONTARIO ON TUESDAY. A SLOW MOVING COLD
FRONT EXTENDING FROM THIS SYSTEM WILL MOVE EAST ACROSS THE AREA
TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THUNDERSTORM AND SHOWER ACTIVITY OVER LIMA OHIO AREA IS BEHAVING
ITSELF LIKE IT SHOULD BASED ON THE LATEST STORM PREDICTION CENTER
CONVECTIVE ANALYSIS. ACTIVITY DEVELOPS OVER RESIDUAL OUTFLOW
BOUNDARIES AND THEN TRIES TO MOVE NORTHEAST ONLY TO WEAKEN AS IT
MOVES INTO OUR SOUTHWEST AREA.
THIS ACTIVITY IS DIURNAL IN NATURE AND WILL LIKELY WEAKEN AS IT
MOVES NORTHEAST AND THE SUN SETS THIS EVENING.
LATEST SATELLITE AND HRRR MODEL INDICATES CONVECTION OVER IOWA
WILL CONTINUE TO MOVE EAST THIS EVENING INTO OUR WESTERN PORTIONS
BY 03Z THIS EVENING. STILL REMAINS TO BE SEEN IF THE INSTABILITY
WILL REMAIN STRONG ENOUGH TO SUPPORT THE ONGOING THUNDERSTORM
ACTIVITY. WILL BE MONITORING THIS THROUGH THE EVENING HOURS.
ONLY NEEDED TO MAKE SOME MINOR ADJUSTMENTS TO HOURLY TEMPERATURES
TO REFLECT THE CURRENT TEMPERATURES.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
ACTIVE WEATHER EXPECTED DURING THE FIRST PART OF THE WEEK AS THE
UPPER LEVEL TROUGH OVER THE PLAINS ADVANCES EASTWARD. THUNDERSTORM
FORECAST CONTINUES TO BE A CHALLENGE AND WILL BE DEPENDENT ON
PLACEMENT OF THE WARM FRONT AND EVOLUTION OF OVERNIGHT CONVECTION.
THE WARM FRONT MAY STILL LINGER IN THE EASTERN PORTION OF THE CWA
DURING THE MORNING AND MAY PROVIDE ENOUGH OF A FOCUS FOR ADDITIONAL
SCATTERED SHOWERS AND THUNDERSTORMS. WILL TAPER POPS DOWN FROM SOUTH
TO NORTH FROM MONDAY AFTERNOON INTO MONDAY NIGHT AS THE ATMOSPHERE
WARMS ALOFT AND A CAP DEVELOPS. HIGHS WILL PEAK IN THE LOW 80S
BENEATH PARTLY SUNNY SKIES ON MONDAY.
THE LOW PRESSURE SYSTEM OVER THE UPPER GREAT LAKES WILL CONTINUE TO
TRACK NORTHEAST INTO ONTARIO THROUGHOUT THE DAY ON TUESDAY.
ASSOCIATED COLD FRONT WILL MOVE INTO NORTHWEST OHIO DURING THE LATE
AFTERNOON WITH SHOWERS AND THUNDERSTORMS SPREADING IN FROM THE WEST.
THE STORM PREDICTION CENTER HAS A SEE TEXT IN PLACE FOR THE
CENTRAL GREAT LAKES ON TUESDAY AS THIS FRONT APPROACHES.
SUFFICIENT INSTABILITY WITH SHEER INCREASING AS THE FRONT
APPROACHES TO HAVE TO KEEP AN EYE ON THUNDERSTORMS IN NW OHIO
DURING THE AFTERNOON AND EVENING. IT LOOKS LIKE THE BETTER FORCING
PASSES TO OUR NORTH ON TUESDAY NIGHT WITH INSTABILITY DIMINISHING
QUICKLY OVERNIGHT. DID TWEAK POPS DOWN A LITTLE BIT FOR THE
OVERNIGHT PERIOD...MAINLY IN THE SOUTH.
MODELS ARE NOW SHOWING A SECONDARY WAVE OF LOW PRESSURE DEVELOPING
ALONG THE GULF COAST AND LIFTING NORTHEAST ACROSS OHIO ON WEDNESDAY
AFTERNOON/WEDNESDAY NIGHT. WIDESPREAD RAIN IS EXPECTED WITH GOOD
UPPER LEVEL DIVERGENCE OVERHEAD AND STRONG UPWARD MOTION AS THE TROUGH
TRIES TO BECOME NEGATIVELY TILTED. RAISED POPS TO 70-80 PERCENT FOR
WEDNESDAY NIGHT. QPF COULD EXCEED AN INCH FOR PORTIONS OF THE AREA
WITH THIS SYSTEM.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
BACK TO BELOW NORMAL TEMPERATURES FOR THIS PERIOD. SOME RESIDUAL
SHOWERS LEFT OVER ON THE BACK SIDE OF THE FRONT ON THURSDAY. THEY
WILL GRADUALLY DECREASE FROM WEST TO EAST. AN UPPER TROF WILL MOVE
ACROSS THE REGION FROM FRIDAY THROUGH SUNDAY. THE BEST CHANCE FOR
SCATTERED SHOWERS WITH THIS TROF WILL BE FRIDAY THROUGH SATURDAY.
THE THREAT OF SHOWERS MAY LINGER IN THE EXTREME EAST ON SUNDAY. WENT
VERY CLOSE TO HPC GUIDANCE FOR THE TEMPERATURE FORECAST.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A WARM FRONT JUST NORTH OF THE OHIO RIVER WILL BEGIN MOVING
NORTHWARD TONIGHT AND SHOULD BE NORTH OF THE AREA AROUND DAYBREAK
MONDAY. THIS SYSTEM WILL INCREASE THE CLOUD COVER AND BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE FORECAST AREA TONIGHT
AND MONDAY.
I WILL USE A COMBINATION OF TSTMS AND VCTS IN THE TAF FORECAST
FOR TONIGHT AND MONDAY.
LOOK FOR THE REMNANTS FROM THE SYSTEM OVER IOWA AND ILLINOIS
TO MOVE ACROSS THE WESTERN PORTIONS OF OUR THE FORECAST AREA
OVERNIGHT AND EARLY MONDAY. ELSEWHERE SOME CLOUDS AND MVFR FOG
ARE POSSIBLE.
.OUTLOOK...NON VFR AT TIMES MONDAY THRU THURSDAY IN SHOWERS AND
THUNDERSTORMS.
&&
.MARINE...
NO SMALL CRAFT ADVISORIES ARE EXPECTED BUT IT COULD BE CLOSE...
MAINLY AFTER A COLD FRONTAL PASSAGE TUESDAY NIGHT INTO WEDNESDAY.
THE BEST CHANCE IS FOR SPECIAL MARINE WARNINGS TO BE ISSUED FOR
STRONG THUNDERSTORMS ON THE LAKE AT TIMES THROUGH TUESDAY NIGHT.
AFTER THAT THE GRADIENT SEEMS TO BE LIGHT AS A RIDGE WILL BE
DOMINATING THE WEATHER OVER MUCH OF THE GREAT LAKES REGION.
AN ONSHORE FLOW DEVELOPED IN THE WEAK GRADIENT THIS AFTERNOON WITH A
RIDGE OVER WESTERN NEW YORK AND PENNSYLVANIA. THIS RIDGE WILL MOVE
EAST TONIGHT AND THE FLOW ON THE LAKE WILL BE MAINLY SOUTH MONDAY
AND MONDAY NIGHT. THE FLOW ALOFT WILL BE MODERATE AND WARM...SO NOT
EXPECTING THE 20 KNOT WINDS TO REACH THE SURFACE OF THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...LOMBARDY
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...BC
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
630 PM EDT SUN MAY 11 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA TONIGHT AS LOW PRESSURE
OVER THE PLAINS TRACKS NORTHEAST INTO THE UPPER MIDWEST. THE LOW
WILL CONTINUE NORTHEAST INTO ONTARIO ON TUESDAY. A SLOW MOVING COLD
FRONT EXTENDING FROM THIS SYSTEM WILL MOVE EAST ACROSS THE AREA
TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THUNDERSTORM AND SHOWER ACTIVITY OVER LIMA OHIO AREA IS BEHAVING
ITSELF LIKE IT SHOULD BASED ON THE LATEST STORM PREDICTION CENTER
CONVECTIVE ANALYSIS. ACTIVITY DEVELOPS OVER RESIDUAL OUTFLOW
BOUNDARIES AND THEN TRIES TO MOVE NORTHEAST ONLY TO WEAKEN AS IT
MOVES INTO OUR SOUTHWEST AREA.
THIS ACTIVITY IS DIURNAL IN NATURE AND WILL LIKELY WEAKEN AS IT
MOVES NORTHEAST AND THE SUN SETS THIS EVENING.
LATEST SATELLITE AND HRRR MODEL INDICATES CONVECTION OVER IOWA
WILL CONTINUE TO MOVE EAST THIS EVENING INTO OUR WESTERN PORTIONS
BY 03Z THIS EVENING. STILL REMAINS TO BE SEEN IF THE INSTABILITY
WILL REMAIN STRONG ENOUGH TO SUPPORT THE ONGOING THUNDERSTORM
ACTIVITY. WILL BE MONITORING THIS THROUGH THE EVENING HOURS.
ONLY NEEDED TO MAKE SOME MINOR ADJUSTMENTS TO HOURLY TEMPERATURES
TO REFLECT THE CURRENT TEMPERATURES.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
ACTIVE WEATHER EXPECTED DURING THE FIRST PART OF THE WEEK AS THE
UPPER LEVEL TROUGH OVER THE PLAINS ADVANCES EASTWARD. THUNDERSTORM
FORECAST CONTINUES TO BE A CHALLENGE AND WILL BE DEPENDENT ON
PLACEMENT OF THE WARM FRONT AND EVOLUTION OF OVERNIGHT CONVECTION.
THE WARM FRONT MAY STILL LINGER IN THE EASTERN PORTION OF THE CWA
DURING THE MORNING AND MAY PROVIDE ENOUGH OF A FOCUS FOR ADDITIONAL
SCATTERED SHOWERS AND THUNDERSTORMS. WILL TAPER POPS DOWN FROM SOUTH
TO NORTH FROM MONDAY AFTERNOON INTO MONDAY NIGHT AS THE ATMOSPHERE
WARMS ALOFT AND A CAP DEVELOPS. HIGHS WILL PEAK IN THE LOW 80S
BENEATH PARTLY SUNNY SKIES ON MONDAY.
THE LOW PRESSURE SYSTEM OVER THE UPPER GREAT LAKES WILL CONTINUE TO
TRACK NORTHEAST INTO ONTARIO THROUGHOUT THE DAY ON TUESDAY.
ASSOCIATED COLD FRONT WILL MOVE INTO NORTHWEST OHIO DURING THE LATE
AFTERNOON WITH SHOWERS AND THUNDERSTORMS SPREADING IN FROM THE WEST.
THE STORM PREDICTION CENTER HAS A SEE TEXT IN PLACE FOR THE
CENTRAL GREAT LAKES ON TUESDAY AS THIS FRONT APPROACHES.
SUFFICIENT INSTABILITY WITH SHEER INCREASING AS THE FRONT
APPROACHES TO HAVE TO KEEP AN EYE ON THUNDERSTORMS IN NW OHIO
DURING THE AFTERNOON AND EVENING. IT LOOKS LIKE THE BETTER FORCING
PASSES TO OUR NORTH ON TUESDAY NIGHT WITH INSTABILITY DIMINISHING
QUICKLY OVERNIGHT. DID TWEAK POPS DOWN A LITTLE BIT FOR THE
OVERNIGHT PERIOD...MAINLY IN THE SOUTH.
MODELS ARE NOW SHOWING A SECONDARY WAVE OF LOW PRESSURE DEVELOPING
ALONG THE GULF COAST AND LIFTING NORTHEAST ACROSS OHIO ON WEDNESDAY
AFTERNOON/WEDNESDAY NIGHT. WIDESPREAD RAIN IS EXPECTED WITH GOOD
UPPER LEVEL DIVERGENCE OVERHEAD AND STRONG UPWARD MOTION AS THE TROUGH
TRIES TO BECOME NEGATIVELY TILTED. RAISED POPS TO 70-80 PERCENT FOR
WEDNESDAY NIGHT. QPF COULD EXCEED AN INCH FOR PORTIONS OF THE AREA
WITH THIS SYSTEM.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
BACK TO BELOW NORMAL TEMPERATURES FOR THIS PERIOD. SOME RESIDUAL
SHOWERS LEFT OVER ON THE BACK SIDE OF THE FRONT ON THURSDAY. THEY
WILL GRADUALLY DECREASE FROM WEST TO EAST. AN UPPER TROF WILL MOVE
ACROSS THE REGION FROM FRIDAY THROUGH SUNDAY. THE BEST CHANCE FOR
SCATTERED SHOWERS WITH THIS TROF WILL BE FRIDAY THROUGH SATURDAY.
THE THREAT OF SHOWERS MAY LINGER IN THE EXTREME EAST ON SUNDAY. WENT
VERY CLOSE TO HPC GUIDANCE FOR THE TEMPERATURE FORECAST.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A WARM FRONT IS OVER THE OHIO RIVER AND WILL BEGIN MOVING NORTH
TONIGHT AND SHOULD BE NORTH OF THE AREA AROUND DAYBREAK MONDAY.
PLENTY OF MID AND HIGH CLOUDS OVER MUCH OF NORTHERN OHIO EARLY
THIS AFTERNOON KEEPING THE TEMPERATURE DOWN. THE CONVECTIVE
TEMPERATURE IS IN THE UPPER 70S. THE TRIGGERS WILL BE THE WARM
FRONT AND A SHORT WAVE THAT WILL MOVE WEST TO EAST ACROSS THE
REGION IN THE MAINLY WESTERLY FLOW ALOFT. IT IS VERY DIFFICULT TO
DECIDE WHERE EXACTLY TO PLACE THE VCTS AND OR TEMPO THUNDER.
SOMEWHAT CONFIDENT LATE TONIGHT THAT THE REMNANT FROM THE SYSTEM
OVER IOWA MAY MOVE ACROSS THE EXTREME NORTHERN PORTION OF THE
FORECAST AREA. ELSEWHERE SOME CLOUDS AND MVFR FOG ARE EXPECTED.
TODAYS AFTERNOON LAKE BREEZE MAY STAY MAINLY NEAR THE LAKESHORE
WITH THE GRADIENT FAIRLY TIGHT AND INCREASING LOW LEVEL WINDS.
.OUTLOOK...NON VFR AT TIMES MONDAY THRU THURSDAY IN SHOWERS AND
THUNDERSTORMS.
&&
.MARINE...
NO SMALL CRAFT ADVISORIES ARE EXPECTED BUT IT COULD BE CLOSE...
MAINLY AFTER A COLD FRONTAL PASSAGE TUESDAY NIGHT INTO WEDNESDAY.
THE BEST CHANCE IS FOR SPECIAL MARINE WARNINGS TO BE ISSUED FOR
STRONG THUNDERSTORMS ON THE LAKE AT TIMES THROUGH TUESDAY NIGHT.
AFTER THAT THE GRADIENT SEEMS TO BE LIGHT AS A RIDGE WILL BE
DOMINATING THE WEATHER OVER MUCH OF THE GREAT LAKES REGION.
AN ONSHORE FLOW DEVELOPED IN THE WEAK GRADIENT THIS AFTERNOON WITH A
RIDGE OVER WESTERN NEW YORK AND PENNSYLVANIA. THIS RIDGE WILL MOVE
EAST TONIGHT AND THE FLOW ON THE LAKE WILL BE MAINLY SOUTH MONDAY
AND MONDAY NIGHT. THE FLOW ALOFT WILL BE MODERATE AND WARM...SO NOT
EXPECTING THE 20 KNOT WINDS TO REACH THE SURFACE OF THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...LOMBARDY
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
350 PM CDT SUN MAY 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 347 PM CDT SUN MAY 11 2014
COMPLEX FORECAST CONTINUES THIS AFTERNOON INTO THE OVERNIGHT.
CURRENT ANALYSIS SHOWS SURFACE LOW PRESSURE OVER WESTERN KANSAS.
KIND OF A DUAL WARM FRONT SIGNATURE. WITH MAIN AND STRONGEST WARM
FRONT ACROSS FAR SOUTHERN NEBRASKA INTO SOUTHWEST IOWA...WHICH WAS
REINFORCED BY THE OVERNIGHT MCS. MODELS IN GOOD AGREEMENT WITH THE
POSITION OF THIS FRONT...AND ALL GUIDANCE SUGGESTS IT WILL ONLY
SLOWLY MOVE NORTH TODAY. THIS IS THE AREA...SOUTHEASTERN NEBRASKA
INTO SOUTHWESTERN IOWA...AT GREATEST RISK FOR SEVERE WEATHER AND
TORNADOES...AS HIGHLIGHTED BY THE SPC OUTLOOK. FURTHER NORTH WE HAVE
A SECONDARY WARM FRONT RUNNING FROM THE TRIPLE POINT OVER SOUTHERN
NEBRASKA...NORTHEAST TO JUST SOUTH OF STORM LAKE. MARGINAL SURFACE
INSTABILITY IS BEGINNING TO FORM IN THIS AREA...ALTHOUGH MOST OF IT
IS REMAINING SOUTH OF OUR CWA. ALSO LARGE SCALE LIFT INCREASING ON
THE NOSE OF A PV WAVE IS HELPING TO TRIGGER ELEVATED SHOWERS AND
THUNDERSTORMS ACROSS THE NORTHWEST HALF OF THE CWA. THESE SHOULD
STAY BELOW SEVERE LIMITS AND PUSH NORTH OF THE AREA BY THIS EVENING.
DAYTIME HEATING AND INCREASING FORCING HAS ALSO HELPED FIRE
CONVECTION ACROSS SOUTH CENTRAL NEBRASKA. THE STRONGEST SURFACE
BASED SUPERCELLS WILL LIKELY RIDE FROM NEAR THE SOUTHERN WARM FRONT
TO THE SECONDARY WARM FRONT...AND THUS STAY SOUTH OF OUR CWA.
ALTHOUGH WILL NEED TO WATCH AREAS FROM SIOUX CITY TO STORM LAKE. LOW
LEVELS REMAIN STABLE...BUT ENOUGH DESTABILIZATION IS POSSIBLE FOR
STORMS MOVING INTO THIS AREA TO TAP INTO THE NEAR SURFACE LAYER. IF
THIS HAPPENED AN ISOLATED TORNADO WOULD BE POSSIBLE. WHILE THIS
STILL SEEMS TO BE A LOW THREAT...IT IS NOT IMPOSSIBLE AND WILL NEED
TO MONITOR TRENDS. SEEMS MORE LIKELY THAT STORMS THAT FORM AND MOVE
INTO OUR CWA WILL STAY ELEVATED...BASED ABOVE THE LOW LEVEL STABLE
LAYER. DECENT ELEVATED INSTABILITY SHOULD INCREASE AND COULD MAKE IT
ALL THE WAY TO ALMOST THE JAMES RIVER. QUESTION IS HOW MUCH MOISTURE
WE CAN GET ADVECTED INTO THE CWA...WITH THE CONVECTION TO OUR SOUTH
HAMPERING THIS TO A DEGREE. SEEMS LIKE A GOOD BET THAT NORTHWEST
IOWA AND SOUTHWEST MINNESOTA WILL GET INTO THE ACTION...LESS CERTAIN
FURTHER NORTHWEST. WITH THE ELEVATED WARM FRONT WELL TO OUR
NORTH...EVEN PARCELS LIFTED FROM NEAR 750 MB SHOULD HAVE AROUND 40
KTS OF SHEAR TO WORK WITH. SO THOUGHT IS ELEVATED SUPERCELLS WILL BE
POSSIBLE IF WE CAN GET THE MOISTURE AND ELEVATED INSTABILITY INTO
THE AREA. MAIN THREAT WOULD BE LARGE HAIL WITH ANY STORM. AGAIN
HIGHEST SEVERE THREAT SHOULD BE ACROSS NORTHWEST IOWA AND ADJACENT
AREAS OF SOUTHWEST MINNESOTA WHERE CONFIDENCE IS HIGHEST ON
INSTABILITY...THREAT IS MORE CONDITIONAL TOWARDS INTERSTATE 29. DO
LIKE THE HRRR IDEA OF PUSHING EVERYTHING EAST BY LATER THIS EVENING
AS STORMS ORGANIZE AND HELP PUSH THE FRONT EATS OF THE CWA. STILL
COULD BE SOME SCATTERED SHOWERS...BUT MOST OF THE OVERNIGHT MAY END
UP FREE OF HEAVY RAIN.
ANOTHER PUSH OF THETAE ADVECTION LATE TONIGHT INTO EARLY MONDAY AS
THE WHOLE SYSTEM BEGINS MOVING NORTHEAST. PRETTY GOOD LARGE SCALE
LIFT TOO AS A STRONG JET ROUNDS THE BASE OF THE TROUGH. THUS
THINKING PRECIPITATION COVERAGE WILL RAPIDLY INCREASE LATER TONIGHT
INTO TOMORROW. MOST OF THIS WEST OF THE JAMES RIVER WILL BE MORE
STABLE SHOWERY PRECIPITATION. DOES LOOK LIKE ELEVATED INSTABILITY
WILL REMAIN TO THE EAST...THUS SHOULD GET SOME THUNDER OUT OF THE
ACTIVITY. MAYBE EVEN SOME MARGINALLY SEVERE HAIL LATE TONIGHT INTO
MONDAY MORNING GIVEN THE WIND PROFILES IF ENOUGH INSTABILITY IS
PRESENT. ANY SURFACE BASED SEVERE WEATHER SHOULD STAY EAST OF THE
CWA. SO OVERALL MONDAY LOOKS LIKE A PRETTY WET DAY WITH HIGHS IN THE
40S AND 50S. WINDS WILL BE ON THE INCREASE AS WELL...WITH AROUND 35
KTS AT 925 MB. WILL BE VERY CLOSE TO WIND ADVISORY CRITERIA ALONG
AND WETS OF THE JAMES RIVER...WITH GUSTS APPROACHING 40 KTS. GIVEN
EXPECTED WEAK MIXING DUE TO THE RAIN AND MARGINAL WINDS ALOFT...WILL
HOLD OFF ON AN ADVISORY FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 347 PM CDT SUN MAY 11 2014
IN THE LONGER TERM...THE WEATHER IS HIGHLIGHTED BY MUCH BELOW
NORMAL TEMPERATURES FOR A BULK OF THE UPCOMING WEEK. FOR MONDAY
NIGHT...DECIDED TO RAISE POPS TO A LOW END LIKELY CATEGORY IN SOME
OF OUR WESTERN ZONES. ALTHOUGH THE GFS IS DRY BY MONDAY EVENING...
THE HIGHER RESOLUTION MODELS DO HANG BACK DEEPER RESIDUAL MOISTURE
IN OUR FORECAST AREA...ESPECIALLY FOR LOCATIONS WEST OF I 29. IN
ADDITION...BOTH THE NAM AND GFS SHOW TROWALING MONDAY EVENING IN
THE 305-315K LAYER. STILL...RAINFALL WILL BE LIGHT EVEN IN OUR
WESTERN ZONES...WITH OUR EASTERN ZONES NOT SEEING MUCH OF A
RAINFALL POTENTIAL. ALTHOUGH COOL...THE CLOUD COVER AND WIND WILL
HELP OUR LOWS FROM PLUMMETING TOO FAR MONDAY NIGHT WITH READINGS
MOSTLY A COUPLE OF DEGREES EITHER SIDE OF 40.
THEN THE UPPER LOW BEGINS TO MEANDER ACROSS SOUTHERN CANADA AND
THE NORTHERN MS VALLEY ALL THE WAY FROM TUESDAY THROUGH THURSDAY...
EVENTUALLY LIFTING INTO THE WESTERN GREAT LAKES BY FRIDAY.
THEREFORE VERY CHILLY WEATHER FOR THIS TIME OF YEAR WILL FOLLOW
SUIT. EVEN THE BIAS CORRECTED TEMPERATURES ARE NOW COLD...AND THEY
HAVE BEEN THE BEST RECENTLY IN OUR FORECAST AREA IN CAPTURING WARM...
MIXED OUT TEMPERATURES DURING THE DAYTIME. INSTABILITY CU WILL
POP ON TUESDAY WITH A STRONG UPPER CYCLONIC FLOW EXISTING...WITH A
SMALL CHANCE FOR LIGHT SHOWERS AROUND BROOKINGS AND SOUTHWEST MN.
AFTER SUNSET...SKIES WILL CLEAR TUESDAY NIGHT FOLLOWED BY SOME
MORE INSTABILITY DAYTIME CU ON WEDNESDAY...AND THERE ARE STRONG
INDICATIONS THAT A SHORT WAVE WILL DIVE DOWN THE NORTHWEST FLOW
ALOFT GIVING THE POSSIBILITY OF MORE WIDELY SCATTERED LIGHT
SHOWERS ACROSS THE ENTIRE FORECAST AREA. BUT LOW POPS ARE STILL
WARRANTED AS A QUESTION EXISTS AS TO HOW MUCH OF THIS RAINFALL
WILL ACTUALLY MEASURE. ULTIMATELY...THIS SHORT WAVE WILL REINFORCE
THE PARENT UPPER LOW AND KEEP OUR CYCLONIC FLOW GOING WITH A FEW
SHOWERS AGAIN POSSIBLE ON THURSDAY.
AS MENTIONED ABOVE...TUESDAY THROUGH THURSDAY WILL BE COLD WITH
HIGHS ONLY IN THE 50S TO AROUND 60. FURTHERMORE...MIXED LAYER
WINDS ARE STOUT ON TUESDAY PROMISING BREEZY CONDITIONS...LESS SO
ON WEDNESDAY BUT STILL THE WIND WILL BE STRONG ENOUGH TO GIVE A
RATHER RAW DAY.
ONE THING TO WATCH FOR BOTH TUESDAY NIGHT AND WEDNESDAY NIGHT AS
SKIES CLEAR AFTER SUNSET AND WINDS SUBSIDE...IS THE POSSIBILITY OF
FROST HERE AND THERE. DID NOT PUT THEM IN THE GRIDS YET...AND
CERTAINLY DID NOT ISSUE ANY FROST HEADLINES. BUT SOME OF OUR LOWS
DO FALL INTO THE MID 30S SO WOULD NOT BE SURPRISED TO SEE SOME
LIGHT FROST IN LOW LYING AREAS.
FURTHER OUT FRIDAY THROUGH SUNDAY...THE UPPER LOW FINALLY MOVES
INTO THE GREAT LAKES...THE NORTH OF THE GREAT LAKES ALLOWING THE
FLOW TO BECOME QUASI ZONAL. THERE MAY BE SOME WARM AIR ADVECTION
SHOWERS ON SUNDAY AS THE NEXT UPPER TROUGH BEGINS TO DIG DOWN THE
WESTERN U.S. COAST. THEREFORE HIGHS WILL FINALLY WARM UP INTO THE
60S FRIDAY THROUGH SUNDAY WITH LOWS ALSO MODERATING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 345 PM CDT SUN MAY 11 2014
CONVECTION IS EXPECTED TO FORM IN NORTHWEST IA AND ADJACENT AREAS
THIS EVENING...AND WAS INCLUDED IN THE KFSD AND KSUX TAF SITES. IT
IS POSSIBLE THAT SOME OF THE STORMS COULD BECOME RATHER STRONG
ESPECIALLY CLOSE TO AN INVERTED TROUGH NEAR SIOUX CITY AND STORM
LAKE...EXTENDING NORTHEASTWARD TO AROUND SPENCER IA. FURTHER
WEST... CONDITIONS WILL BE MORE STABLE AT KHON SO ONLY RAIN WAS
MENTIONED THERE. THE CATEGORIES WILL LIKELY LOWER INTO THE IFR AND
LOWER END MVFR CATEGORIES BY OVERNIGHT AND LASTING THROUGH MONDAY
MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...MJ
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1212 PM CDT SUN MAY 11 2014
.UPDATE...
ISSUED AT 1144 AM CDT SUN MAY 11 2014
COMPLEX FORECAST THIS AFTERNOON INTO THE OVERNIGHT. CURRENT ANALYSIS
SHOWS SURFACE LOW PRESSURE OVER WESTERN KANSAS. KIND OF A DUAL WARM
FRONT SIGNATURE. WITH MAIN AND STRONGEST WARM FRONT ACROSS FAR
SOUTHERN NEBRASKA INTO SOUTHWEST IOWA...WHICH WAS REINFORCED BY THE
OVERNIGHT MCS. MODELS IN GOOD AGREEMENT WITH THE POSITION OF THIS
FRONT...AND ALL GUIDANCE SUGGESTS IT DOES NOT MOVE MUCH TODAY. THIS
IS THE AREA AT GREATEST RISK FOR SEVERE WEATHER AND TORNADOES...AS
HIGHLIGHTED BY THE SPC OUTLOOK. FURTHER NORTH EXPECT A SECONDARY WARM
FRONT TO SETUP. NAM IS FURTHEST NORTH WITH THIS FEATURE...PUSHING IT
AS FAR NORTH AS SIOUX CITY TO SPENCER. RAP AND HRRR KEEP IT MAINLY
JUST SOUTH OF THE CWA. IT IS POSSIBLE THAT MARGINAL SURFACE BASED
INSTABILITY COULD DEVELOP NEAR AND SOUTH OF THIS SECOND BOUNDARY.
ALTHOUGH MID LEVEL CLOUDINESS MAY MAKE THIS TOUGH...SO WILL NEED TO
MONITOR TRENDS.
AS FAR AS PRECIPITATION CHANCES GO...THINK WE SEE OFF AN ON SHOWERS
THROUGH THE DAY BUT NOTHING TOO SIGNIFICANT. WE WILL HAVE TO WAIT FOR
DEVELOPMENT LATER THIS AFTERNOON INTO TONIGHT AS LARGE SCALE FORCING
AND THETAE ADVECTION BOTH INCREASE. UNCERTAINTY ON WHERE IT RAINS
IS HIGH...AND LIKELY DEPENDENT ON HOW THE CONVECTION ACROSS NEBRASKA AND
IOWA IMPACT INFLOW INTO OUR REGION. THE STRONGEST SURFACE BASED
SUPERCELLS WILL LIKELY RIDE NEAR THE SOUTHERN WARM FRONT AND STAY
SOUTH OF OUR CWA. HOWEVER DO THINK WE WILL SEE STORMS FIRE CLOSER TO
THE SECONDARY WARM FRONT AS WELL...AND THESE WOULD IMPACT NORTHWEST
IOWA INTO SOUTHWEST MINNESOTA. AS MENTIONED ABOVE...IF WE WERE TO GET
SOME SURFACE BASED INSTABILITY FROM SIOUX CITY TO STORM LAKE...THERE
WOULD BE A TORNADO THREAT GIVEN THE VERY STRONG LOW LEVEL AND DEEP
LAYER SHEAR. AT THIS POINT CONTINUE TO THINK THIS IS A LOW
PROBABILITY EVENT...AND WILL KEEP OUT OF THE HWO FOR NOW...BUT
SOMETHING TO KEEP AN EYE ON. MORE LIKELY THAT STORMS ARE
ELEVATED...ALTHOUGH TURNING OF THE WINDS IS STILL STRONG ALOFT. THUS
ELEVATED SUPERCELLS WITH LARGE HAIL STILL SEEM POSSIBLE. ELEVATED
INSTABILITY IS PRESENT ALL THE WAY TO ALMOST THE JAMES RIVER.
QUESTION IS HOW MUCH MOISTURE WE CAN GET ADVECTED INTO THE CWA...WITH
THE CONVECTION TO OUR SOUTH HAMPERING THIS TO A DEGREE. IF STORMS
WERE TO FORM TOWARDS INTERSTATE 29...LARGE HAIL WOULD BE
POSSIBLE...GIVEN THE STEEP LAPSE RATES AND STRONG ELEVATED WIND
SHEAR. SO THE HIGHEST SEVERE THREAT...FOR MAINLY LARGE HAIL...REMAINS
IN NORTHWEST IOWA...ALTHOUGH A CONDITIONAL THREAT EXISTS ACROSS
SOUTHEAST SOUTH DAKOTA AND SOUTHWEST MINNESOTA...AND WILL ADD MENTION
INTO THE HWO.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM CDT SUN MAY 11 2014
CONVERGENCE ALONG 925 MB BOUNDARY STARTING TO LIGHT UP WITH STORMS.
AS THIS BOUNDARY LIFTS NORTH THROUGH THE MORNING...EXPECT FIRST WAVE
OF STORMS TO MOVE INTO NORTHWEST IOWA. WITH LIMITED AMOUNTS OF
INSTABILITY...AM NOT EXPECTING SEVERE WEATHER BUT COULD GET SOME
SMALL HAIL. FURTHER BACK TO THE WEST...DEFORMATION BAND OF SHOWERS
SHOULD CONTINUE TO PROGRESS TO THE NORTH THROUGHOUT THE MORNING
HOURS. THEREAFTER...EXPECT BREAK IN CONVECTION BUT CLOUD COVER WILL
BE A CONCERN THIS FAR TO THE NORTH IN TERMS OF DESTABILIZATION.
MODELS STILL SUGGEST THAT SURFACE BOUNDARY WILL TRY TO WORK NORTH
LATE THIS AFTERNOON INTO FAR SOUTHEAST CORNER OF THE FORECAST AREA
NEAR STORM LAKE TO SPENCER. IF BOUNDARY IS ABLE TO WORK THAT FAR
NORTH...POTENTIAL FOR SURFACE BASED CONVECTION INCLUDING
TORNADOES... STRONG VEERING PROFILES CERTAINLY SUPPORTIVE OF
SUPERCELLS...WITH HELICITY VALUES EXCEEDING 600 M2/S2. WITH SUCH
STRONG SPIN IN THE ATMOSPHERE...ADDED MENTION OF LARGE HAIL IN THE
GRIDS-BUT HELD OFF ON MENTION OF DAMAGING WINDS AND TORNADOES AS
QUESTION OF WHETHER SURFACE BASED CONVECTION WILL BE ABLE TO SURVIVE
THIS FAR NORTH. FOR TONIGHT...PWAT VALUES CONTINUE TO CLIMB THROUGH
THE EVENING HOURS TO NEARLY 1.5 INCHES EAST OF THE 925 HPA
BOUNDARY. IN ADDITION TO MENTION OF LARGE HAIL IN THE SOUTH
EAST...HAVE ALSO ADDED A MENTION OF HEAVY RAIN POTENTIAL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM CDT SUN MAY 11 2014
STRONG 700 MB FRONTOGENETIC BAND PERSISTS ACROSS THE FORECAST AREA
THROUGH THE DAY ON MONDAY...STRETCHING NEARLY NORTH TO SOUTH THROUGH
THE CENTER OF THE FORECAST AREA. THERE ARE SOME SLIGHT MODEL
DIFFERENCES IN THE LOCATION OF THIS BAND...WITH THE NAM...GFS AND
GEM FURTHER WEST OF CENTER THAN THE ECMWF. WIDESPREAD RAIN
SHOWERS...PERHAPS MORE STRATIFORM IN NATURE WILL BE ONGOING ACROSS
MUCH OF SOUTHEAST SOUTH DAKOTA. TO THE EAST...REMNANTS OF NOCTURNAL
CONVECTION WILL LIKELY ALSO BE ONGOING IN NORTHWEST IOWA AROUND
DAYBREAK...MAINLY ACROSS OUR FAR SOUTHWEST CORNER. EXPECT THIS
ACTIVITY TO WANE BY LATE MORNING...WITH ADDITIONAL RAIN SHOWERS AND
SOME LINGERING THUNDER IN THE FAR EAST ARRIVING IN THE AFTERNOON AS
THE MID LEVEL FRONT SHIFTS EASTWARD. WITH THE ELONGATED TROUGH
SWINGING THROUGH THE FORECAST AREA...BREEZY NORTHWESTERLY
WINDS...AND CLOUDS AND RAIN WILL MAKE FOR AN UNSEASONABLY BRISK DAY.
TEMPERATURES LIKELY WILL NOT FLUCTUATE MUCH FROM MORNING LOWS WITH
HIGHS ONLY REACHING THE UPPER 40S TO LOWER 50S IN SE SD...AND THE
MID 50S TO NEAR 60 IN OUR EASTERN HALF OF THE CWA.
HEADING INTO MONDAY NIGHT...THE NAM BECOMES A SIGNIFICANT OUTLIER IN
DEVELOPING A UPPER LEVEL CLOSED LOW OVER NORTH CENTRAL NEBRASKA
WHILE THE OTHER MODELS LIFT THE TROUGH INTO THE UPPER MIDWEST
OVERNIGHT. AS A RESULT...THE NAM IS MUCH SLOWER IN SHUTTING OFF THE
PRECIPITATION FOR THE REGION. GIVEN THE BETTER AGREEMENT WITH THE
OTHER MODELS...DISCOUNTED THE NAM SOLUTION. LIGHT RAIN TAPERS OFF
FROM SOUTH TO NORTH MONDAY NIGHT AND DRIER NORTHWEST FLOW RETURNS TO
THE NORTHERN PLAINS.
THE TROUGH DOES MANAGE TO BECOME HUNG UP OVER THE UPPER MIDWEST WITH
SEVERAL IMPULSES POTENTIALLY CLIPPING THE FORECAST AREA.
OVERALL...BELOW NORMAL TEMPERATURES APPEAR TO BE THE RULE WITHOUT
ANY REAL SIGN OF A WARMING TREND UNTIL THE VERY END OF THE WEEK.
COULD SEE SOME ISOLATED SHOWERS CLIP OUR NORTHEASTERN HALF ON
TUESDAY AFTERNOON. WITH SO MUCH MODEL UNCERTAINTY...DID NOT STRAY
TOO FAR FROM ALLBLEND GUIDANCE FOR POPS MID TO LATE WEEK. WITH
PRETTY DRY LOW LEVELS...SUBSTANTIAL PRECIPITATION MAY BE HARD TO
COME BY. BUT WILL LEAVE IN SOME SLIGHT CHANCE SHOWERS WEDNESDAY AND
THURSDAY AND AGAIN ON SATURDAY. HIGHS PRIMARILY IN THE 50S...WARMING
BACK INTO THE 60S BY SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 634 AM CDT SUN MAY 11 2014
LEADING STRATIFORM MCS IS EXPECTED TO WEAKEN AS IT LIFTS
NORTHEAST...BUT SHOULD STILL PRODUCE A FEW HOURS OF SHOWERS AND
THUNDERSTORMS ACROSS NORTHWEST IOWA THIS MORNING. EXPECT MVFR
STRATUS TO DEVELOP THROUGHOUT THE DAY UNDER EASTERLY FLOW AHEAD OF
WARM FRONT LIFTING NORTH. AS COLD FRONT/INVERTED TROUGH SHIFTS
EAST...LOWER STRATUS SHOULD AFFECT THE AREA CONTINUING THROUGH THE
OVERNIGHT. PRECIPITATION TIMING ON BACKSIDE OF THIS SYSTEM
SOMEWHAT FUZZY RIGHT NOW...BUT LOW END MVFR TO IFR STRATUS
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
916 PM CDT MON MAY 12 2014
.UPDATE...EARLIER CONVECTION HAS DISSIPATED WITH A HUMID AIR MASS
IN PLACE AS DEW POINTS REMAIN ON THE NORTH SIDE OF 60 DEGREES. THE
EVENING SOUNDING SHOWS AN UNSTABLE ENVIRONMENT IN PLACE, WITH A
LIFTED INDEX OF -3.9 AND CONVECTIVE AVAILABLE POTENTIAL ENERGY OF
1,500 J/KG. PRECIPITABLE WATER REMAINS 1.39 INCHES WITH A K-INDEX
OF 30. CANNOT RULE OUT ANY OVERNIGHT CONVECTION AS ACTIVE WEATHER
CONTINUES JUST WEST OF THE MISSISSIPPI RIVER AND THE HRRR DOES
APPEAR TO DEVELOP A FEW CELLS WEST OF I-65 TOWARD MORNING, SO WILL
LEAVE IN SLIGHT CHANCE POP`S OVERNIGHT. AT THIS TIME, NO FORECAST
CHANGES ARE PLANNED.
&&
.PREV DISCUSSION... /ISSUED 603 PM CDT MON MAY 12 2014/
UPDATE...FOR 00Z AVIATION FORECASTS.
AVIATION...BEST BREEDING GROUND FOR POP-UP THUNDERSTORMS THIS
EVENING IS EXPECTED TO BE OVER WESTERN MIDDLE TN. THUS, HAVE
INCLUDED A MENTION OF VCTS FOR CKV UNTIL 02Z. OTHERWISE, LOOK FOR
VFR CONDITIONS AT ALL MID STATE TERMINALS THROUGH THE FORECAST
PERIOD, WITH ANOTHER ROUND OF ISOLATED CONVECTION LATE TUESDAY
MORNING AND AFTERNOON.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
755 PM CDT MON MAY 12 2014
.UPDATE...
THE WEATHER PATTERN THIS EVENING ACROSS THE MIDSOUTH IS TURNING
TOWARD A MORE ACTIVE ONE FOR NEXT COUPLE OF DAYS. A STRONG COLD
FRONT STRETCHED FROM NORTHEAST MO INTO WESTERN AR AND NORTHEAST
TX. WARM...MOIST AND UNSTABLE AIR WAS PUSHING INTO THE MIDSOUTH
ON MODERATE SOUTHERLY WINDS. THE 00Z LZK SOUNDING INDICATED A
SBCAPE OF 3700 J/KG WITH A PRECIPITABLE WATER VALUE OF 1.58
INCHES. SURFACE DEW POINTS WERE IN THE MIDDLE AND UPPER 60S. A
SOLID LINE OF THUNDERSTORMS EXTENDED AHEAD OF THE COLD FRONT AND
WAS PUSHING EASTWARD INTO NORTH CENTRAL AR. SCATTERED SHOWERS AND
THUNDERSTORMS WERE DEVELOPING ACROSS THE MIDSOUTH ALONG AND WEST
OF THE MS RIVER...THIS IS DEPICTED WELL BY THE HRRR MODEL...WITH
THIS CONVECTION MOVING TO NORTH. THE LINE OF STORMS AHEAD OF THE
FRONT WILL MOVE INTO NORTHEAST AR AND THE MO BOOTHEEL LATER
TONIGHT WITH HEAVY RAINFALL THE MAIN THREAT...A FLASH FLOOD WATCH
BEGINS FOR THE AREA AFTER MIDNIGHT.
UPDATED TO REMOVE OUTDATED WORDING. OTHERWISE...CURRENT FORECAST
HAS A GOOD HANDLE ON THE DEVELOPING SITUATION. HOWEVER...MAY NEED TO
EXTEND SMALL POPS A LITTLE FURTHER EASTWARD OVER PORTIONS OF NORTH
MS IF ISOLATED CONVECTION OVER NORTH CENTRAL MS HOLD TOGETHER AS
IT MOVES NORTHWARD.
JCL
&&
.DISCUSSION... /ISSUED 348 PM CDT MON MAY 12 2014/
A DEEP UPPER LEVEL TROUGH CONTINUES TO SLOWLY PUSH EAST THROUGH
THE PLAINS STATES THIS AFTERNOON. AT THE SURFACE...A COLD FRONT
HAS ADVANCED EASTWARD INTO WESTERN MISSOURI AND EASTERN OKLAHOMA.
A LINE OF THUNDERSTORMS HAS FORMED ALONG THE FRONT AND CONTINUES
TO ADVANCE EASTWARD. TO THE EAST...ACROSS MUCH OF THE MID
SOUTH...ABUNDANT LOW LEVEL MOISTURE ALONG WITH SURFACE HEATING HAS
SUPPORTED ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THIS
ACTIVITY SHOULD DIMINISH IN COVERAGE THIS EVENING WITH MAINLY DRY
WEATHER PERSISTING EAST OF THE MISSISSIPPI RIVER THROUGH MIDNIGHT.
TO THE WEST OF THE RIVER...THE LINE OF STORMS NOW MOVING ACROSS
EASTERN OKLAHOMA WILL ADVANCE INTO WESTERN PORTIONS OF THE
FORECAST AREA WELL AFTER MIDNIGHT. THESE STORMS SHOULD BE TRENDING
WEAKER BY THE TIME IT REACHES OUR AREA...AS THEY BEGIN TO PUSH
AHEAD OF THE BETTER FORCING ALOFT THAT WILL BE FOCUSED FURTHER
WEST.
LINGERING MORNING SHOWERS ACROSS THE WEST SHOULD FALL APART DURING
THE MORNING HOURS TUESDAY...BEFORE NEW ACTIVITY FORMS ALONG THE
ADVANCING COLD FRONT ACROSS EASTERN ARKANSAS AND THE MISSOURI
BOOTHEEL. THIS ACTIVITY SHOULD BE SLOW MOVING AND ONLY ADVANCE AS
FAR EAST AS THE MISSISSIPPI RIVER COUNTIES BY TUESDAY AFTERNOON.
SLOW MOVEMENT AND POSSIBLE TRAINING OF THUNDERSTORMS MAY LEAD TO
SOME HEAVY RAINFALL ACROSS AREAS WEST OF THE MISSISSIPPI RIVER. A
FLASH FLOOD WATCH HAS BEEN ISSUED FOR THESE LOCATIONS ON TUESDAY.
FURTHER EAST...DAYTIME HEATING AND INCREASING INSTABILITY MAY
RESULT IN SCATTERED PULSE TYPE SHOWERS AND THUNDERSTORMS.
A MORE POTENT SHORTWAVE WILL BEGIN TO EJECT OUT OF THE BASE OF THE
UPPER TROUGH TO OUR WEST TUESDAY NIGHT INTO WEDNESDAY. BY THIS
TIME...THE SURFACE COLD FRONT SHOULD BE POSITIONED ACROSS WEST
TENNESSEE INTO NORTHWEST MISSISSIPPI. NUMEROUS SHOWERS AND
THUNDERSTORMS WILL DEVELOP ON THE COLD SIDE OF THE BOUNDARY
TUESDAY NIGHT WITH CONTINUED POTENTIAL FOR HEAVY RAINFALL. AS THE
SHORTWAVE MOVES EAST ON WEDNESDAY...IT MAY TAKE ON A MORE NEUTRAL
TO EVEN POSITIVE TILT ORIENTATION AS IT OVERSPREADS THE REMAINDER
OF THE MID SOUTH BY WEDNESDAY AFTERNOON. AS THIS
OCCURS IT SHOULD HELP TO INDUCE A SURFACE LOW PRESSURE SYSTEM
WHICH SHOULD LIFT NORTHEAST ACROSS EASTERN PORTIONS OF THE
FORECAST AREA. THUNDERSTORMS SHOULD DEVELOP ACROSS THE REMAINING WARM
SECTOR IN PLACE ACROSS PORTIONS OF WEST TENNESSEE...NEAR THE
TENNESSEE RIVER...INTO NORTHEAST MISSISSIPPI. THE AIRMASS ACROSS
THE WARM SECTOR SHOULD REMAIN WARM AND HUMID WITH DEEP LAYER SHEAR
VALUES INCREASING IN ADVANCE OF THE SHORTWAVE. INSTABILITY AND
SHEAR MAY BE SUFFICIENT TO RESULT IN A FEW SEVERE THUNDERSTORMS
OVER THE AFOREMENTIONED REGIONS WEDNESDAY AFTERNOON AND EVENING.
THERE STILL REMAINS SOME UNCERTAINTY WITH REGARD TO THE QUALITY OF
THE WARM SECTOR AND HOW MUCH INSTABILITY WILL EXIST. LATER SHIFTS
WILL CONTINUE TO MONITOR THIS SEVERE WEATHER POTENTIAL AND WILL
PROVIDE FORECAST UPDATES AS NEEDED.
THE COLD FRONT SHOULD MOVE EAST OF THE REGION WEDNESDAY NIGHT WITH
SHOWERS AND THUNDERSTORMS ENDING FROM WEST TO EAST. AN UPPER LEVEL
LOW PRESSURE SYSTEM OVER THE UPPER MISSISSIPPI VALLEY WILL DROP
SOUTHEAST INTO THE MIDWEST THROUGH THE END OF THE WEEK AND INTO
THE FIRST PART OF NEXT WEEKEND. A SERIES OF SHORTWAVE DISTURBANCES
WILL ROTATE ACROSS THE AREA ALONG THE SOUTHERN PERIPHERY OF THIS
UPPER LOW. THIS SHOULD KEEP CHANCES FOR SHOWERS AND A FEW
THUNDERSTORMS IN THE FORECAST DURING THIS TIME PERIOD. IN
ADDITION...MUCH COOLER TEMPERATURES CAN BE EXPECTED. IN
FACT...TEMPERATURES SHOULD AVERAGE ANYWHERE FROM 10-20 DEGREES
BELOW AVERAGE FOR THIS TIME OF THE YEAR.
THE UPPER LOW WILL FINALLY MOVE EAST BY THE END OF NEXT WEEKEND
WITH A RETURN TO DRY CONDITIONS AND WARMER TEMPERATURES.
JLH
&&
.AVIATION...
00Z TAF CYCLE
VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING HOURS. A FEW
ISOLATED THUNDERSTORMS HAVE DEVELOPED OVER PORTIONS OF THE
FORECAST AREA AND SHOULD DIE OUT SHORTLY AFTER SUNSET. A LINE OF
SHOWERS AND THUNDERSTORMS WILL BEGIN TO MOVE INTO THE FORECAST
AREA LATE TONIGHT AND SLOWLY MOVE EAST THROUGH THE REMAINDER OF
FORECAST PERIOD. EXPECT MVFR VISIBILITIES AND MVFR/IFR CEILINGS
WITH THIS AREA OF CONVECTION. WINDS WILL BE SOUTH AT 10 TO 15
KNOTS TONIGHT AND GRADUALLY SHIFT TO A MORE WESTERLY DIRECTIONS
OVER WESTERN SECTIONS OF THE FORECAST AREA TUESDAY AFTERNOON.
ARS
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 1 AM CDT TUESDAY THROUGH WEDNESDAY
EVENING FOR CLAY-CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-
LEE AR-MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH FROM 1 AM CDT TUESDAY THROUGH WEDNESDAY
EVENING FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
835 PM CDT MON MAY 12 2014
.UPDATE...
PRIMARILY DISCRETE SHOWER ACTIVITY...WITH EMBEDDED ISOLATED
STORMS/MORE ORGANIZED N-S ORIENTED CONVECTIVE LINES...BLOSSOMING
UP ACROSS THE NORTHWEST-NORTH CWA AND FEEDING INTO THE MAIN QLCS
CURRENTLY ENTERING OUR FAR NORTHERN CWA. COOL POOL SEEMING TO KICK
IN ALONG ITS WESTERN FLANK AND PUSHING THIS ONCE VERY SLOW-MOVING
LINE MORE PROGRESSIVELY SE`WARD INTO OUR FORECAST AREA. SHORT TERM
HIGH REZ MODELING HAS A MORE RAGGED CONVECTIVE LINE SPEEDING UP
AND REACHING THE NORTHERN FRINGES OF THE CITY AROUND MIDNIGHT OR 1
AM...TO THE COAST BY 3 OR 4 AM. THESE SOLUTIONS ALSO PROVIDE THE
GREATEST SOUTHERN PUSH TO THE LINE ACROSS THE WESTERN CWA
THUS...WITH THIS VELOCITY...AREAWIDE AVERAGE QPF WILL BE UNDER TWO
INCHES WITH LOCALIZED 3 TO 4 INCHES. BULK OF RAIN SHOULD FALL
ALONG AND WEST OF I-45 THROUGH TUESDAY MORNING. NEVERTHELESS...THE
PROBABILITY OF LOCALIZED 3-4 INCH TOTALS...LEADING TO NUISANCE
FLOODING OF LOCAL AREA ROADWAYS...WILL MAINTAIN TUESDAY MORNING`S
NW`ERN CWA`S FLASH FLOOD WATCH. 31
&&
.PREV DISCUSSION... /ISSUED 647 PM CDT MON MAY 12 2014/
DISCUSSION...
HOUSTON RADAR WIND PROFILE STILL SHOWING 40KT AT 2000FT. NOT MUCH
MIXING TO THE SFC INLAND SO KEPT MENTION OF LLVL WIND SHEAR IN
PLACE FOR THE SHORT TERM.
MAIN ISSUE WILL BE TIMING/INTENSITY OF LINE OF STORMS CURRENTLY
IN N TX MOVING INTO SE TX. ASSUMING CURRENT SPEED STAYS ABOUT THE
SAME IT SHOULD BE MOVING INTO CLL/UTS TERMINALS ROUGHLY AROUND 3Z
(10PM), UTS 4Z (11PM), CXO 5Z (12AM), IAH 6Z (1AM), HOU/SGR 7-8Z
(2-3AM), GLS 9Z (4AM). HRRR MODEL SEEMS TO CURRENTLY HAVE THE
BETTER HANDLE ON CURRENT SITUATION FWIW.
IF COLD POOL BEHIND THE LINE BECOMES LESS SIGNIFICANT THERE IS A
DECENT CHANCE THE LINE SLIGHTLY SLOWS DOWN AS IT APPROACHES
HOUSTON TERMINALS AND...ACCORDING TO ALMOST ALL AVAILABLE
GUIDANCE...THERE`S ALSO A PRETTY GOOD CHANCE OF GRADUAL WEAKENING
ONCE IT GETS PAST ABOUT THE CXO AREA.
FOR THE TERMINALS NORTH OF THE METRO AREA THE PRIMARY ISSUE WILL
BE REDUCED VISIBILITIES DUE TO LOCALIZED HEAVY DOWNPOURS WITHIN
THE LEADING LINE ALONG WITH SOME WIND GUSTS TO 20-35KT.
SEVERAL HOURS OF GENERALLY STRATIFORM RAIN ANTICIPATED IN THE
WAKE OF THE INITIAL LINE. COMBINATION OF MVFR/IFR CIGS SHOULD BE
THE RULE. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 64 65 55 68 49 / 100 80 40 20 10
HOUSTON (IAH) 73 75 59 72 53 / 70 70 50 30 10
GALVESTON (GLS) 75 76 66 72 62 / 20 60 50 40 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH FROM 1 AM CDT TUESDAY THROUGH TUESDAY
AFTERNOON FOR THE FOLLOWING ZONES: AUSTIN...BRAZOS...
BURLESON...COLORADO...GRIMES...HOUSTON...MADISON...WALLER...
WASHINGTON.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT TUESDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...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.
&&
$$
DISCUSSION...31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
647 PM CDT MON MAY 12 2014
.DISCUSSION...
HOUSTON RADAR WIND PROFILE STILL SHOWING 40KT AT 2000FT. NOT MUCH
MIXING TO THE SFC INLAND SO KEPT MENTION OF LLVL WIND SHEAR IN
PLACE FOR THE SHORT TERM.
MAIN ISSUE WILL BE TIMING/INTENSITY OF LINE OF STORMS CURRENTLY
IN N TX MOVING INTO SE TX. ASSUMING CURRENT SPEED STAYS ABOUT THE
SAME IT SHOULD BE MOVING INTO CLL/UTS TERMINALS ROUGHLY AROUND 3Z
(10PM), UTS 4Z (11PM), CXO 6Z (1AM), IAH 7-8Z (2-3AM), HOU/SGR 9Z
(4AM), GLS 11Z (6AM). HRRR MODEL SEEMS TO CURRENTLY HAVE THE
BETTER HANDLE ON CURRENT SITUATION FWIW.
IF COLD POOL BEHIND THE LINE BECOMES LESS SIGNIFICANT THERE IS A
DECENT CHANCE THE LINE SLIGHTLY SLOWS DOWN AS IT APPROACHES
HOUSTON TERMINALS AND...ACCORDING TO ALMOST ALL AVAILABLE
GUIDANCE...THERE`S ALSO A PRETTY GOOD CHANCE OF GRADUAL WEAKENING
ONCE IT GETS PAST ABOUT THE CXO AREA.
FOR THE TERMINALS NORTH OF THE METRO AREA THE PRIMARY ISSUE WILL
BE REDUCED VISIBILITIES DUE TO LOCALIZED HEAVY DOWNPOURS WITHIN
THE LEADING LINE ALONG WITH SOME WIND GUSTS TO 20-35KT.
SEVERAL HOURS OF GENERALLY STRATIFORM RAIN ANTICIPATED IN THE
WAKE OF THE INITIAL LINE. COMBINATION OF MVFR/IFR CIGS SHOULD BE
THE RULE. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 66 70 55 68 49 / 100 80 40 20 10
HOUSTON (IAH) 72 79 59 72 53 / 70 70 50 30 10
GALVESTON (GLS) 74 79 66 72 62 / 20 60 50 40 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH FROM 1 AM CDT TUESDAY THROUGH TUESDAY
AFTERNOON FOR THE FOLLOWING ZONES: AUSTIN...BRAZOS...
BURLESON...COLORADO...GRIMES...HOUSTON...MADISON...WALLER...
WASHINGTON.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT TUESDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
629 AM CDT SUN MAY 11 2014
.DISCUSSION...
SEE THE 12Z AVIATION DISCUSSION BELOW.
40
&&
.AVIATION...
ALTHOUGH THERE WERE A FEW BREAKS...MVFR TO IFR CEILINGS WERE OVER
THE TERMINAL SITES AT 11Z. THE NAM12 MODEL SHOWED A GOOD POTENTIAL
FOR BREAKS TO BECOME MORE PREVALENT MAINLY THROUGH 16Z.
OTHERWISE...THE MVFR DECK SHOULD GRADUALLY BECOME VFR FROM KHOU
AND KSGR INLAND TO KCLL AND KUTS. AS THE CEILINGS RISE...BREEZY
SURFACE WINDS ARE EXPECTED. LOW CEILINGS OVER THE GULF PLATFORMS
CONCUR WITH THE MODELS IN KEEPING MVFR CONDITIONS OVER KGLS AND
KLBX THROUGHOUT THE DAY.
DO NOT SEE MUCH CHANGE IN THE AIRMASS TONIGHT. WARM AIR AND MOIST
ADVECTION WILL PERSIST. CONDITIONS WILL WORSEN THIS EVENING AND
WILL LIKELY BECOME MVFR AND PROBABLY IFR AROUND 00Z AT KGLS AND
KLBX...AND BETWEEN 03Z AND 06Z OVER THE REMAINING INLAND SITES.
40
&&
.PREV DISCUSSION... /ISSUED 404 AM CDT SUN MAY 11 2014/
DISCUSSION...
AT 3 AM...TEMPERATURES WERE STILL IN THE MID 70S. SOME PATCHY
DRIZZLE MOVED THROUGH EARLIER IN THE NIGHT AND WOULD NOT BE
SURPRISED IF MORE LIGHT RAIN DEVELOPS THIS MORNING. THE RAP 13
SHOWS A CLUSTER OF SHRA/TSRA DEVELOPING OVER PARTS OF EASTERN
HARRIS...GALVESTON...LIBERTY AND CHAMBERS COUNTIES THIS AFTN. THE
HRR IS LESS AGGRESSIVE BUT IT SHOWS SOMETHING SIMILAR. PW VALUES
ARE PROGGED TO BE AROUND 1.4-1.5 INCHES AND UPPER LEVEL WINDS WILL
REMAIN BROADLY DIVERGENT. CAN`T RULE OUT A STRAY SHOWER ACROSS THE
CWA...SO WILL MAINTAIN THE 20 POPS ALREADY IN PLACE.
PWATS INCREASE TO AROUND 1.7 INCHES ON MONDAY AFTN. CAPE VALUES
ARE ABOVE 2000 AND LI`S ARE -8. A CAPPING INVERSION IS STILL IN
PLACE DURING THE MORNING BUT RAPIDLY ERODES IN THE AFTN. A WEAK
UPPER LEVEL DISTURBANCE WILL APPROACH SE TX IN THE AFTN AND THIS
FEATURE COUPLED WITH STRONGLY DIVERGENT UPPER LEVEL WINDS AND
DAYTIME HEATING SHOULD ALLOW SHRA/TSRA TO DEVELOP IN THE AFTN.
ALTHO CURRENTLY NOT OUTLOOKED BY SPC...THERE ARE ENOUGH PARAMETERS
IN PLACE TO GET AT LEAST SOME PULSE SEVERE STORMS ON MON AFTN.
THE UPPER TROUGH INCHES EVER CLOSER MON NITE AND TUESDAY. THE
UPPER JET IS IN A FAVORABLE POSITION AND SE TX WILL LIE IN A RRQ
OF A SPLITTING JET. PWATS INCREASE TO 1.7-1.9 INCHES AND CAPPING
IS NO LONGER AN ISSUE. A SURFACE COLD FRONT WILL SLOWLY CROSS SE
TX ON TUESDAY AND WILL SERVE AS THE LOW LEVEL FOCUS FOR SHRA/TSRA.
POST FRONTAL RAINS ARE ALSO EXPECTED AS THE UPPER TROUGH LAGS
BEHIND A BIT. CONVERGENCE IS ALSO LOOKING PRETTY STOUT AT 850 MB.
LOCALLY HEAVY RAIN WILL BE POSSIBLE ON TUESDAY OVER PARTS OF SE
TX DUE TO THE HIGH MOISTURE CONTENT...FAVORABLE UPPER LEVEL WINDS
AND THE POTENTIAL FOR TRAINING OF STORMS. WPC HAS A RATHER
GENEROUS QPF BULLSEYE OVER SE TX. LIGHT RAIN WILL LINGER TUESDAY
NIGHT AND WILL END WEDNESDAY MORNING ONCE THE UPPER TROUGH PUSHES
EAST OF THE REGION. FWIW...THE NAM 12 IS CONSIDERABLY WEAKER WITH
THE UPPER TROUGH AND DRIER WITH VERY LITTLE RAIN OVER SE TX. THE
NAM IS CURRENTLY THE OUTLIER BUT IT HAS PERFORMED RELATIVELY WELL
AS OF LATE.
SKIES SHOULD CLEAR ON WEDNESDAY AFTN WITH GENERALLY CLEAR SKIES
THROUGH NEXT WEEKEND. TEMPERATURES WILL BE UNSEASONABLY COOL IN
THE WAKE OF TUESDAYS COLD FRONT. MIN TEMPS WILL FALL INTO THE 50S
WED-FRI WITH MAYBE SOME 40S ON THURSDAY MORNING. TEMPS WILL WARM
TO SEASONAL NORMALS BY NEXT WEEKEND. 43
MARINE...
IN ADDITION TO MODERATE TO STRONG ONSHORE WINDS...AREAS OF DRIZZLE
AND LIGHT RAIN WILL AFFECT THE MARINE AREAS THIS MORNING. WENT WITH
HIGHER WIND SPEEDS THAN FORECAST BY THE MODELS GIVEN THE GOOD
THERMAL GRADIENT IN PLACE. THE PRESSURE GRADIENT IS ALSO FORECAST BY
THE MODELS TO BE INCREASING LATER THIS MORNING.
LIKED A COMBINATION OF THE NAM12 AND MOS GUIDANCE TONIGHT THROUGH
MONDAY NIGHT. STAYED WITH THE GFS OUTPUT FOR THE FRONTAL PASSAGE OFF
THE COAST TUESDAY EVENING. STRONG OFFSHORE WINDS WILL THEN QUICKLY
BECOME NORTHEAST AND DIMINISH LATE WEDNESDAY AND THURSDAY MORNING.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 89 73 87 65 74 / 20 10 50 60 60
HOUSTON (IAH) 88 74 86 72 82 / 20 10 40 50 60
GALVESTON (GLS) 83 74 82 74 81 / 20 10 30 40 60
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY...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...47
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
404 AM CDT SUN MAY 11 2014
.DISCUSSION...
AT 3 AM...TEMPERATURES WERE STILL IN THE MID 70S. SOME PATCHY
DRIZZLE MOVED THROUGH EARLIER IN THE NIGHT AND WOULD NOT BE
SURPRISED IF MORE LIGHT RAIN DEVELOPS THIS MORNING. THE RAP 13
SHOWS A CLUSTER OF SHRA/TSRA DEVELOPING OVER PARTS OF EASTERN
HARRIS...GALVESTON...LIBERTY AND CHAMBERS COUNTIES THIS AFTN. THE
HRR IS LESS AGGRESSIVE BUT IT SHOWS SOMETHING SIMILAR. PW VALUES
ARE PROGGED TO BE AROUND 1.4-1.5 INCHES AND UPPER LEVEL WINDS WILL
REMAIN BROADLY DIVERGENT. CAN`T RULE OUT A STRAY SHOWER ACROSS THE
CWA...SO WILL MAINTAIN THE 20 POPS ALREADY IN PLACE.
PWATS INCREASE TO AROUND 1.7 INCHES ON MONDAY AFTN. CAPE VALUES
ARE ABOVE 2000 AND LI`S ARE -8. A CAPPING INVERSION IS STILL IN
PLACE DURING THE MORNING BUT RAPIDLY ERODES IN THE AFTN. A WEAK
UPPER LEVEL DISTURBANCE WILL APPROACH SE TX IN THE AFTN AND THIS
FEATURE COUPLED WITH STRONGLY DIVERGENT UPPER LEVEL WINDS AND
DAYTIME HEATING SHOULD ALLOW SHRA/TSRA TO DEVELOP IN THE AFTN.
ALTHO CURRENTLY NOT OUTLOOKED BY SPC...THERE ARE ENOUGH PARAMETERS
IN PLACE TO GET AT LEAST SOME PULSE SEVERE STORMS ON MON AFTN.
THE UPPER TROUGH INCHES EVER CLOSER MON NITE AND TUESDAY. THE
UPPER JET IS IN A FAVORABLE POSITION AND SE TX WILL LIE IN A RRQ
OF A SPLITTING JET. PWATS INCREASE TO 1.7-1.9 INCHES AND CAPPING
IS NO LONGER AN ISSUE. A SURFACE COLD FRONT WILL SLOWLY CROSS SE
TX ON TUESDAY AND WILL SERVE AS THE LOW LEVEL FOCUS FOR SHRA/TSRA.
POST FRONTAL RAINS ARE ALSO EXPECTED AS THE UPPER TROUGH LAGS
BEHIND A BIT. CONVERGENCE IS ALSO LOOKING PRETTY STOUT AT 850 MB.
LOCALLY HEAVY RAIN WILL BE POSSIBLE ON TUESDAY OVER PARTS OF SE
TX DUE TO THE HIGH MOISTURE CONTENT...FAVORABLE UPPER LEVEL WINDS
AND THE POTENTIAL FOR TRAINING OF STORMS. WPC HAS A RATHER
GENEROUS QPF BULLSEYE OVER SE TX. LIGHT RAIN WILL LINGER TUESDAY
NIGHT AND WILL END WEDNESDAY MORNING ONCE THE UPPER TROUGH PUSHES
EAST OF THE REGION. FWIW...THE NAM 12 IS CONSIDERABLY WEAKER WITH
THE UPPER TROUGH AND DRIER WITH VERY LITTLE RAIN OVER SE TX. THE
NAM IS CURRENTLY THE OUTLIER BUT IT HAS PERFORMED RELATIVELY WELL
AS OF LATE.
SKIES SHOULD CLEAR ON WEDNESDAY AFTN WITH GENERALLY CLEAR SKIES
THROUGH NEXT WEEKEND. TEMPERATURES WILL BE UNSEASONABLY COOL IN
THE WAKE OF TUESDAYS COLD FRONT. MIN TEMPS WILL FALL INTO THE 50S
WED-FRI WITH MAYBE SOME 40S ON THURSDAY MORNING. TEMPS WILL WARM
TO SEASONAL NORMALS BY NEXT WEEKEND. 43
&&
.MARINE...
IN ADDITION TO MODERATE TO STRONG ONSHORE WINDS...AREAS OF DRIZZLE
AND LIGHT RAIN WILL AFFECT THE MARINE AREAS THIS MORNING. WENT WITH
HIGHER WIND SPEEDS THAN FORECAST BY THE MODELS GIVEN THE GOOD
THERMAL GRADIENT IN PLACE. THE PRESSURE GRADIENT IS ALSO FORECAST BY
THE MODELS TO BE INCREASING LATER THIS MORNING.
LIKED A COMBINATION OF THE NAM12 AND MOS GUIDANCE TONIGHT THROUGH
MONDAY NIGHT. STAYED WITH THE GFS OUTPUT FOR THE FRONTAL PASSAGE OFF
THE COAST TUESDAY EVENING. STRONG OFFSHORE WINDS WILL THEN QUICKLY
BECOME NORTHEAST AND DIMINISH LATE WEDNESDAY AND THURSDAY MORNING.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 89 73 87 65 74 / 20 10 50 60 60
HOUSTON (IAH) 88 74 86 72 82 / 20 10 40 50 60
GALVESTON (GLS) 83 74 82 74 81 / 20 10 30 40 60
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 1 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY...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 LA CROSSE WI
810 PM CDT MON MAY 12 2014
.UPDATE...
ISSUED AT 810 PM CDT MON MAY 12 2014
WITH A WEAKLY CAPPED ENVIRONMENT TO THE SOUTH AND
EAST...CONVECTION DEVELOPED QUICKLY ALONG THE BRIM OF THE WARM
SECTOR AND BASICALLY CUT OFF THE LOCAL REGION OF ANY SIGNIFICANT
CONVECTION. BECAUSE OF THIS...HAVE ENDED BOTH THE SEVERE
THUNDERSTORM WATCH AND FLASH FLOOD WATCH FOR THE REGION AS BOTH
THREATS HAVE GONE TO THE EAST.
THE MAIN FOCUS NOW IS ON THE COLD FRONT WHICH JUST WENT THROUGH
ROCHESTER MN AND CHARLES CITY IOWA. TEMPERATURES DROP FROM THE LOW
70S TO THE MID 50S WITH WINDS TURNING TO THE NORTHWEST AS THE
FRONT PASSES. DRIZZLE IS ALSO OCCURRING BEHIND THE FRONT AS WELL
AND WILL LAST FOR A PERIOD THIS EVENING AND OVERNIGHT UNTIL DRIER
850MB AIR COMES IN ON THE BACK SIDE OF THE SYSTEM.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 328 PM CDT MON MAY 12 2014
FOCUS OF THE FORECAST IS ON THE RAIN CHANCES AND IMPACTS TONIGHT.
LATEST SURFACE ANALYSIS SUGGESTS THE INVERTED TROUGH/COLD FRONT
EXTENDS FROM NORTHWEST WISCONSIN INTO WESTERN WISCONSIN. HARD TO
DEFINE A COMPACT AREA OF LOW PRESSURE BUT LOOKS TO BE MORE OF AN
ELONGATED FEATURE ALONG THE TROUGH/FRONT FROM SOUTHEAST MINNESOTA
ACROSS MUCH OF IOWA. A WARM FRONT LOOKED TO EXTEND ACROSS
NORTHEAST IOWA INTO NORTHERN ILLINOIS...ROUGHLY ALONG THE HIGHWAY
20 CORRIDOR. LOCAL AND REGIONAL RADARS SHOWING A LINE OF
CONVECTION ALONG THE COLD FRONT FROM NORTHEAST IOWA INTO WESTERN
MISSOURI/EASTERN KANSAS.
LATEST ANALYSIS INDICATES AROUND 500 J/KG OF SB CAPE WAS ALONG
INTERSTATE 90 BUT THIS INCREASED TO ALMOST 2000 J/KG ALONG THE
SOUTHERN BORDER OF THE FORECAST AREA. THE 12.18Z RAP SUGGESTS
THESE HIGHER CAPE VALUES WILL SPREAD ACROSS THE EASTERN PARTS OF
THE FORECAST AREA THROUGH THE REST OF THE AFTERNOON INTO THE EARLY
EVENING. THE RAP BUFKIT SOUNDINGS STILL SUGGESTS THIS IS
PRIMARILY A TALL SKINNY CAPE PROFILE WHICH WOULD SUGGEST THAT
LARGE HAIL MAY NOT BE MUCH OF A THREAT. FOR ANY STORMS THAT GET
INTO THE AREA AND CAN ORIENT WITH THE 0-3KM SHEAR
VECTORS...DAMAGING WIND WILL BE POSSIBLE. CANNOT TOTALLY RULE OUT
AN ISOLATED TORNADO AS THE WARM FRONT MOVES INTO THE AREA...BUT
BECAUSE OF THE ELONGATED SURFACE LOW...NOT REALLY SEEING ANY
LOCALIZED BACKING OF THE WINDS TO ENHANCE THE LOW LEVEL HELICITY.
CURRENTLY EXPECTING THE LINE OF ACTIVITY ACROSS IOWA INTO MISSOURI
TO CONTINUE TRANSLATING NORTHEAST AHEAD OF THE TROUGH/FRONT AND
PRIMARILY AFFECTING THE EASTERN SECTIONS OF THE FORECAST AREA FROM
NORTHEAST IOWA INTO CENTRAL WISCONSIN. HAVE LINED UP THE RAIN
CHANCES WITH 80 PERCENT OVER THIS AREA TRAILING BACK TO ABOUT A 40
PERCENT CHANCE ACROSS THE WEST. AS THE TROUGH/COLD FRONT ADVANCES
SLOWLY EAST TONIGHT...THE RAIN CHANCES WILL ESSENTIALLY END FROM
WEST TO EAST AND EXPECT THE ENTIRE AREA TO BE DRY BY 12Z TUESDAY.
AFTER TONIGHT...SOME SMALL RAIN CHANCES RETURN TO THE SOUTHEAST
PARTS OF THE FORECAST AREA WEDNESDAY NIGHT. THE MEAN LONG WAVE
TROUGH WILL REMAIN OVER THE CENTRAL PART OF THE COUNTRY THANKS TO
AN UPPER LEVEL LOW NEAR HUDSON BAY AND ANOTHER SHORT WAVE TROUGH
COMING OUT OF THE SOUTHWEST PART OF THE COUNTRY. THIS SHORT WAVE
TROUGH IS EXPECTED TO PASS OFF JUST TO THE SOUTHEAST OF THE AREA
ACROSS ILLINOIS WITH THE SURFACE LOW NEAR THE OHIO RIVER. THE
DEFORMATION AREA OF RAIN ON THE NORTHWEST SIDE OF THE LOW COULD
EXTEND BACK INTO THE AREA AND WILL HAVE THE SMALL RAIN CHANCES FOR
THIS POSSIBILITY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 328 PM CDT MON MAY 12 2014
THE LONG WAVE TROUGH WILL THEN MOVE SLOWLY NORTHEAST AS SEVERAL
WEAKER SHORT WAVE TROUGHS COME INTO THE LONG WAVE TROUGH ON THE
NORTHWEST FLOW FROM SOUTHERN AND WESTERN CANADA. THIS WILL PROVIDE
JUST ENOUGH FORCING FOR SOME SMALL RAIN CHANCES THURSDAY THROUGH
FRIDAY...SATURDAY AND AGAIN MONDAY. TEMPERATURES WILL STILL BE
COOL TO CLOSE OUT THE WEEK BUT THEN START TO MODERATE FOR THE
WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 707 PM CDT MON MAY 12 2014
WHILE SOME SHOWERS AND POSSIBLY A THUNDERSTORM COULD MOVE THROUGH
THE REGION EARLY THIS EVENING...THE MAIN FOCUS IS ON THE CHANGES
COMING ONCE A COLD FRONT MOVES THROUGH THIS EVENING. THIS FRONT IS
JUST ABOUT TO CROSS THROUGH RST WITH A BRIEF PERIOD OF MVFR 2500FT
CEILINGS FOLLOWED QUICKLY BY IFR CEILINGS BETWEEN 500-900FT AND
SOME DRIZZLE WHICH IS CAUSING VIS TO DROP DOWN TO AROUND 2SM. IT
LOOKS LIKE THERE WILL BE ABOUT A 4-6 HOUR PERIOD OF THESE
CONDITIONS BEFORE SOME DRIER AIR MOVES IN AND ENDS THE DRIZZLE
THOUGH THE LOW CEILINGS WILL LIKELY PERSIST THROUGH MUCH OF THE
MORNING. THE QUESTION THEN IS WHEN WILL THE CEILINGS IMPROVE ABOVE
IFR/MVFR TOMORROW WITH GUIDANCE SUGGESTING IT WILL BE IN THE
AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 328 PM CDT MON MAY 12 2014
AS THE STORMS COME IN ACROSS THE EASTERN SECTIONS TONIGHT...THE
TALL SKINNY CAPE PROFILE SHOULD LEAD TO MORE RAIN DROP PRODUCTION
INSTEAD OF HAIL. THIS CAN ALSO BE SEEN IN THE WARM CLOUD
DEPTHS...WHICH THE 12.18Z NAM CONTINUES TO SHOW TO BE AROUND 3500
METERS. WHILE THE QPF THAT FALLS THROUGH THE REST OF THE AFTERNOON
AND EVENING MAY BE AN INCH OR LESS...IT WILL BE FALLING ON GROUND
THAT RECEIVED UP TO 1.5 INCHES SUNDAY NIGHT. WITH THE GROUND BEING
SATURATED FROM THESE PREVIOUS RAINS...THE ADDITIONAL RAIN COULD
STILL PRODUCE SOME LOCALIZED FLOODING PROBLEMS AND WILL CONTINUE
THE FLASH FLOOD WATCH FOR ALL BUT THE FAR NORTHWEST SECTION OF THE
FORECAST AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
707 PM CDT MON MAY 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 328 PM CDT MON MAY 12 2014
FOCUS OF THE FORECAST IS ON THE RAIN CHANCES AND IMPACTS TONIGHT.
LATEST SURFACE ANALYSIS SUGGESTS THE INVERTED TROUGH/COLD FRONT
EXTENDS FROM NORTHWEST WISCONSIN INTO WESTERN WISCONSIN. HARD TO
DEFINE A COMPACT AREA OF LOW PRESSURE BUT LOOKS TO BE MORE OF AN
ELONGATED FEATURE ALONG THE TROUGH/FRONT FROM SOUTHEAST MINNESOTA
ACROSS MUCH OF IOWA. A WARM FRONT LOOKED TO EXTEND ACROSS
NORTHEAST IOWA INTO NORTHERN ILLINOIS...ROUGHLY ALONG THE HIGHWAY
20 CORRIDOR. LOCAL AND REGIONAL RADARS SHOWING A LINE OF
CONVECTION ALONG THE COLD FRONT FROM NORTHEAST IOWA INTO WESTERN
MISSOURI/EASTERN KANSAS.
LATEST ANALYSIS INDICATES AROUND 500 J/KG OF SB CAPE WAS ALONG
INTERSTATE 90 BUT THIS INCREASED TO ALMOST 2000 J/KG ALONG THE
SOUTHERN BORDER OF THE FORECAST AREA. THE 12.18Z RAP SUGGESTS
THESE HIGHER CAPE VALUES WILL SPREAD ACROSS THE EASTERN PARTS OF
THE FORECAST AREA THROUGH THE REST OF THE AFTERNOON INTO THE EARLY
EVENING. THE RAP BUFKIT SOUNDINGS STILL SUGGESTS THIS IS
PRIMARILY A TALL SKINNY CAPE PROFILE WHICH WOULD SUGGEST THAT
LARGE HAIL MAY NOT BE MUCH OF A THREAT. FOR ANY STORMS THAT GET
INTO THE AREA AND CAN ORIENT WITH THE 0-3KM SHEAR
VECTORS...DAMAGING WIND WILL BE POSSIBLE. CANNOT TOTALLY RULE OUT
AN ISOLATED TORNADO AS THE WARM FRONT MOVES INTO THE AREA...BUT
BECAUSE OF THE ELONGATED SURFACE LOW...NOT REALLY SEEING ANY
LOCALIZED BACKING OF THE WINDS TO ENHANCE THE LOW LEVEL HELICITY.
CURRENTLY EXPECTING THE LINE OF ACTIVITY ACROSS IOWA INTO MISSOURI
TO CONTINUE TRANSLATING NORTHEAST AHEAD OF THE TROUGH/FRONT AND
PRIMARILY AFFECTING THE EASTERN SECTIONS OF THE FORECAST AREA FROM
NORTHEAST IOWA INTO CENTRAL WISCONSIN. HAVE LINED UP THE RAIN
CHANCES WITH 80 PERCENT OVER THIS AREA TRAILING BACK TO ABOUT A 40
PERCENT CHANCE ACROSS THE WEST. AS THE TROUGH/COLD FRONT ADVANCES
SLOWLY EAST TONIGHT...THE RAIN CHANCES WILL ESSENTIALLY END FROM
WEST TO EAST AND EXPECT THE ENTIRE AREA TO BE DRY BY 12Z TUESDAY.
AFTER TONIGHT...SOME SMALL RAIN CHANCES RETURN TO THE SOUTHEAST
PARTS OF THE FORECAST AREA WEDNESDAY NIGHT. THE MEAN LONG WAVE
TROUGH WILL REMAIN OVER THE CENTRAL PART OF THE COUNTRY THANKS TO
AN UPPER LEVEL LOW NEAR HUDSON BAY AND ANOTHER SHORT WAVE TROUGH
COMING OUT OF THE SOUTHWEST PART OF THE COUNTRY. THIS SHORT WAVE
TROUGH IS EXPECTED TO PASS OFF JUST TO THE SOUTHEAST OF THE AREA
ACROSS ILLINOIS WITH THE SURFACE LOW NEAR THE OHIO RIVER. THE
DEFORMATION AREA OF RAIN ON THE NORTHWEST SIDE OF THE LOW COULD
EXTEND BACK INTO THE AREA AND WILL HAVE THE SMALL RAIN CHANCES FOR
THIS POSSIBILITY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 328 PM CDT MON MAY 12 2014
THE LONG WAVE TROUGH WILL THEN MOVE SLOWLY NORTHEAST AS SEVERAL
WEAKER SHORT WAVE TROUGHS COME INTO THE LONG WAVE TROUGH ON THE
NORTHWEST FLOW FROM SOUTHERN AND WESTERN CANADA. THIS WILL PROVIDE
JUST ENOUGH FORCING FOR SOME SMALL RAIN CHANCES THURSDAY THROUGH
FRIDAY...SATURDAY AND AGAIN MONDAY. TEMPERATURES WILL STILL BE
COOL TO CLOSE OUT THE WEEK BUT THEN START TO MODERATE FOR THE
WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 707 PM CDT MON MAY 12 2014
WHILE SOME SHOWERS AND POSSIBLY A THUNDERSTORM COULD MOVE THROUGH
THE REGION EARLY THIS EVENING...THE MAIN FOCUS IS ON THE CHANGES
COMING ONCE A COLD FRONT MOVES THROUGH THIS EVENING. THIS FRONT IS
JUST ABOUT TO CROSS THROUGH RST WITH A BRIEF PERIOD OF MVFR 2500FT
CEILINGS FOLLOWED QUICKLY BY IFR CEILINGS BETWEEN 500-900FT AND
SOME DRIZZLE WHICH IS CAUSING VIS TO DROP DOWN TO AROUND 2SM. IT
LOOKS LIKE THERE WILL BE ABOUT A 4-6 HOUR PERIOD OF THESE
CONDITIONS BEFORE SOME DRIER AIR MOVES IN AND ENDS THE DRIZZLE
THOUGH THE LOW CEILINGS WILL LIKELY PERSIST THROUGH MUCH OF THE
MORNING. THE QUESTION THEN IS WHEN WILL THE CEILINGS IMPROVE ABOVE
IFR/MVFR TOMORROW WITH GUIDANCE SUGGESTING IT WILL BE IN THE
AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 328 PM CDT MON MAY 12 2014
AS THE STORMS COME IN ACROSS THE EASTERN SECTIONS TONIGHT...THE
TALL SKINNY CAPE PROFILE SHOULD LEAD TO MORE RAIN DROP PRODUCTION
INSTEAD OF HAIL. THIS CAN ALSO BE SEEN IN THE WARM CLOUD
DEPTHS...WHICH THE 12.18Z NAM CONTINUES TO SHOW TO BE AROUND 3500
METERS. WHILE THE QPF THAT FALLS THROUGH THE REST OF THE AFTERNOON
AND EVENING MAY BE AN INCH OR LESS...IT WILL BE FALLING ON GROUND
THAT RECEIVED UP TO 1.5 INCHES SUNDAY NIGHT. WITH THE GROUND BEING
SATURATED FROM THESE PREVIOUS RAINS...THE ADDITIONAL RAIN COULD
STILL PRODUCE SOME LOCALIZED FLOODING PROBLEMS AND WILL CONTINUE
THE FLASH FLOOD WATCH FOR ALL BUT THE FAR NORTHWEST SECTION OF THE
FORECAST AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH UNTIL 1 AM CDT TUESDAY FOR WIZ029-034-041>044-
053>055-061.
MN...FLASH FLOOD WATCH UNTIL 1 AM CDT TUESDAY FOR MNZ096.
IA...FLASH FLOOD WATCH UNTIL 1 AM CDT TUESDAY FOR IAZ010-011-029-030.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
325 PM CDT SUN MAY 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM CDT SUN MAY 11 2014
FOCUS OF THE FORECAST IS ON RAIN THROUGH TUESDAY.
REGIONAL RADARS SHOW A CONVECTIVE COMPLEX HAS SURVIVED FROM THE
OVERNIGHT HOURS AND CONTINUES TO TRANSLATE ACROSS SOUTHERN IOWA.
THAT HAS EFFECTIVELY PINNED THE WARM FRONT WELL SOUTH OF THE AREA
ALONG THE IOWA/MISSOURI BORDER. THIS HAS ALSO PINNED MOST OF THE
CAPE TO THE SOUTH WITH THE 19Z MU CAPE SHOWING LESS THAN 500 J/KG
ACROSS THE AREA. THE CONCERN BECOMES WHAT HAPPENS THIS EVENING AS
THE COMPLEX CONTINUES TO MOVE EAST AND IF THE WARM FRONT CAN MAKE
A MOVE NORTH. THE 11.17Z HRRR SUGGESTS THAT THE WARM FRONT WILL
START TO PUSH NORTH THIS EVENING BUT MAY STILL BE ONLY ABOUT AS
FAR NORTH AS THE INTERSTATE 80 CORRIDOR BY 03Z. THE WARM FRONT
COULD THEN GET PUSHED NORTHEAST THROUGH THE REST OF THE EVENING
AND NIGHT AS A STRONG SHORT WAVE TROUGH MOVES NORTHEAST ACROSS THE
REGION. THE 11.12Z NAM DOES SUGGEST BETWEEN 1000-1500 J/KG OF ML
CAPE WILL BE IN PLACE ALONG AND NEAR THE WARM FRONT...BUT IF THE
WARM FRONT GETS PUSHED NORTHEAST...THIS CAPE MAY JUST CLIP THE
SOUTHEAST PORTIONS OF THE AREA. HOWEVER...IF THIS SCENARIO DOES
NOT PLAY OUT AND THE CAPE IS FARTHER WEST...THERE WILL STILL BE A
SEVERE THREAT. THE 0-6KM SHEAR THIS EVENING SHOULD INCREASE TO A
RANGE OF 30 TO 50 KNOTS THIS EVENING THEN TO AROUND 60 KNOTS FOR
THE OVERNIGHT HOURS. THE NAM REMAINS CONSISTENT SHOWING 200-300
M2/S2 OF HELICITY OVER THE AREA IN THE 0-3KM LAYER WITH THE BULK
OF THE RESIDING THE 0-1KM LAYER. SO IF THE WARM FRONT CAN GET INTO
THE AREA...THERE WOULD STILL BE A THREAT FOR AN ISOLATED
TORNADO...BUT CONFIDENCE ON THE POSITION OF THE WARM FRONT IS NOT
VERY HIGH.
CONFIDENCE IS HIGH THAT IT WILL RAIN TONIGHT. THE MODELS HAVE BEEN
CONVERGING TOWARD THE SCENARIO THAT AS THE SHORT WAVE TROUGH
COMES OUT OF THE CENTRAL PLAINS AND MOVES NORTHEAST OVER THE
REGION TONIGHT THAT CONVECTION WILL FORM ALONG AN INVERTED TROUGH.
THIS TROUGH CURRENTLY EXTENDS FROM THE SOUTHWEST KANSAS ACROSS
WESTERN IOWA INTO WESTERN WISCONSIN. AS THE SHORT WAVE TROUGH
COMES OUT...MODERATE PV ADVECTION IN THE 500-300 MB LAYER IS
EXPECTED TO OCCUR. IN THE LOW LEVELS...THE WARM AIR ADVECTION WILL
INCREASE AHEAD OF THE WAVE WITH 5 TO 7 UBAR/S OF UP GLIDE ON THE
300K ISENTROPIC SURFACE WITH THE MOISTURE TRANSPORT ON THIS LEVEL
RIGHT INTO THE AREA. EXPECT TO SEE THE LINE OF CONVECTION DEVELOP
IN RESPONSE TO THIS WAVE FROM SOUTHERN MINNESOTA INTO KANSAS AND
THEN MOVE NORTHEAST ACROSS THE AREA THROUGH THE NIGHT. ONCE THE
SHORT WAVE TROUGH MOVES PAST...THE FORCING WILL SHIFT BACK TO THE
WEST AGAIN AHEAD OF THE MAIN LONG WAVE TROUGH AND THE EMBEDDED
SHORT WAVE TROUGH. THIS IS EXPECTED TO MAKE THE MAIN SURFACE LOW
MOVE FROM KANSAS INTO MINNESOTA OR WISCONSIN DURING THE DAY
MONDAY WITH THE COLD FRONT ADVANCING EAST INTO THE AREA. ANOTHER
ROUND OF VERY SIMILAR ISENTROPIC UP GLIDE AND MOISTURE TRANSPORT
IS EXPECTED ON THE 300K SURFACE FOR CONTINUED SHOWERS AND
THUNDERSTORMS AHEAD OF THE FRONT. EVERYTHING THEN STARTS TO
TRANSLATE EAST FOR MONDAY NIGHT WITH THE RAIN CHANCES ENDING FROM
WEST TO EAST THROUGH TUESDAY MORNING.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 325 PM CDT SUN MAY 11 2014
WILL CARRY SOME SMALL RAIN CHANCES FOR WEDNESDAY THROUGH FRIDAY
AND THEN SOME ON AND OFF CHANCES OVER THE WEEKEND. ONCE THE SYSTEM
FROM EARLY IN THE WEEK MOVES PAST...THE LONG WAVE TROUGH LOOKS TO
REMAIN OVER THE CENTRAL PART OF THE COUNTRY WITH A NORTHWEST FLOW
FROM NORTHWEST CANADA. THIS SHOULD ALLOW SEVERAL WEAK SHORT WAVE
TROUGHS TO ROTATE THROUGH THE LONG WAVE TROUGH TO SUPPORT THE RAIN
CHANCES. THIS FLOW WILL ALSO HELP TO KEEP TEMPERATURES BELOW
NORMAL WITH HIGHS IN THE 50S TO END THE WEEK AND THEN CREEPING
BACK INTO THE 60S FOR THE WEEKEND. OVERNIGHT LOWS WILL BE IN THE
30S AND MAY HAVE TO DEAL WITH SOME FROST HEADLINES TOWARD THE END
OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1227 PM CDT SUN MAY 11 2014
MUCH OF THE NEXT 24 HRS WILL BE DOMINATED BY SHRA/TSRA IN AND AROUND
THE AREA. FIRST BAND OF MAINLY -SHRA WILL MOVE ACROSS THE TAF SITES
EARLY THIS AFTERNOON WITH LCL MVFR VSBYS IN THE -RA BUT CIGS MOSTLY
IN THE 5K-8KT FT RANGE. AREA LOOKS TO GET A BREAK FROM THE SHRA/TSRA
FOR THE MID AFTERNOON INTO EARLY EVENING HOURS AS THE MAIN FORCING
IS FOCUSED MORE INTO SOUTHERN/EASTERN IA. VFR CONDITIONS EXPECTED FOR
MUCH OF THE MID AFTERNOON TO EARLY EVENING HOURS. DEEPER MOISTURE
AND STRONGER FORCING/LIFT SPREAD BACK INTO THE AREA BY MID EVENING
WITH A BROAD AREA OF SHRA/TSRA EXPECTED TO OVERSPREAD THE TAF SITES
IN ROUGHLY THE 03Z-12Z TIME-FRAME. MAINLY VFR/MVFR CIGS/VSBYS
EXPECTED IN THE SHRA/TSRA WITH IFR CIGS/VSBYS IN +TSRA AND THE HEAVY
DOWNPOURS. THESE DO NOT LOOK TO PREVAIL AT THE TAF SITES...BUT 12 TO
18 HRS OUT THEY REMAIN DIFFICULT TO TIME THUS INCLUSION OF A LONGER
THAN DESIRED PERIOD TEMPO IFR CONDITIONS LATER TONIGHT. NOT A LOT OF
CONFIDENCE IN THE DETAILS FOR MON MORNING BUT APPEARS AREA WILL GET
A BREAK FROM THE HEAVIER/STRONGER/MORE WIDESPREAD TSRA. GIVEN THE
UNCERTAINTY...FOR NOW CARRIED 5SM -SHRA WITH CB THRU MON MORNING
&&
.HYDROLOGY...
ISSUED AT 325 PM CDT SUN MAY 11 2014
RAINFALL FROM THIS SYSTEM THROUGH MONDAY SHOULD AVERAGE AROUND 2
INCHES FOR MUCH OF THE FORECAST AREA WITH LOCALIZED HIGHER AMOUNTS
EXPECTED. MANY OF THE RIVERS REMAIN HIGH FROM RECENT RUN OFFS AND
THE LATEST FORECASTS FROM THE RFC INDICATED WITHIN BANK RISES FOR
MANY OF THE TRIBUTARIES WITH RENEWED FLOODING POSSIBLE AT SOME
SPOTS ALONG THE MISSISSIPPI. IF THE RAINFALL ENDS UP BEING HIGHER
THAN THE QPF USED BY THE RFC...WHICH IS HIGH PROBABILITY...SOME
THE TRIBUTARIES COULD ALSO GO TO FLOOD. BASED ON THIS...HAVE OPTED
TO ISSUE A FLOOD WATCH FOR THE ENTIRE AREA FOR TONIGHT AND MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH MONDAY EVENING
FOR WIZ017-029-032>034-041>044-053>055-061.
MN...FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH MONDAY EVENING
FOR MNZ079-086>088-094>096.
IA...FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH MONDAY EVENING
FOR IAZ008>011-018-019-029-030.&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION.....RRS
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
225 PM CDT SUN MAY 11 2014
.REST OF THIS AFTERNOON AND TONIGHT - CONFIDENCE...MEDIUM SPC MESO
PAGE CONTINUES TO SHOW DESTABILIZATION IN THE MID LEVELS WITH MUCAPE
INCREASING. ELEVATED HAIL PRODUCING STORMS WILL MOVE TAKING SHAPE
ACRS NE IA. LOW LEVELS ALSO DESTABLIZED. SSW WINDS HAVE BROUGHT 60
PLUS DEW POINT AIR INTO PARTS OF SC WI. HAIL AND HEAVY RAIN APPEAR
TO BE THE MAIN THREATS DUE TO FAVORABLE MID LEVEL LAPSE RATES AND
MOISTURE ADVECTION. 0-6KM SHEAR NOT THAT FAVORABLE. FOR LATER
TONIGHT...UPPER TROUGH AND PRIMARY SHORTWAVE ENERGY AT THE BASE OF
TROUGH WILL CONTINUE TO SHIFT EAST FROM THE ROCKIES. A LEAD
SHORTWAVE PICKED UP BY THE MODELS IS EXPECTED TO REACH NW WI BY 12Z.
SURFACE LOW WILL HEAD NORTHEAST AND BECOME SOMEWHAT ELONGATED FROM
MN THROUGH WRN IA. WIND FLOW WILL RESPOND AND INCREASE FROM THE
SOUTH. LOW LEVEL JET DOES TRANSLATE EASTWARD A BUT THOUGH PRIMARY
FORCING IS WEST. HOWEVER ENOUGH MOISTURE ADVECTION AND SPEED
CONVERGENCE TO SUPPORT TSRA ACRS THE CWA. HRRR SHOWING POTENTIAL MCS
ARRIVING AFTER 7Z OR SO INTO WRN CWA. 12Z NAM AND 12Z GFS DO FOCUS
THE STRONGEST CONVECTION CLOSER TO THE NOSE OF THE JET TO OUR
WEST...HOWEVER 12Z ECMWF/12Z GEM LEAN THE JET CLOSER TO SRN WI WITH
QPF PANELS RESPONDING WITH A MORE ORGANIZED CONVECTIVE COMPLEX
TAKING SHAPE. GIVEN THE SHORTWAVE RIDING NORTHEAST AND PLACEMENT OF
LLJ AXIS...WILL PLAY IT THAT MORE ORGANIZED CONVECTION RETURNS LATER
TONIGHT AFTER A BREAK BETWEEN THE AFTN/EARLY EVE STORMS.
.MONDAY - CONFIDENCE...MEDIUM LEADING EDGE OF UPPER TROUGH DYNAMICS
PUSH INTO WRN IA AND WRN MN. STRONG SOUTHWEST UPPER FLOW ACRS SRN
WI. WARM SECTOR WILL BE WELL ENTRENCHED ACRS SRN WI. MODELS IN
GENERAL GREEMENT IN TAKING SURFACE LOW FROM MN TOWARDS NW WI.
WARM...MOIST AND UNSTABLE AIRMASS IN PLACE. THE UPPER JET WILL BE
WELL TO OUR WEST THOUGH MODELS HINTING AT SOME UPPER DIVERGENCE
HERE. BUFKIT SOUNDINGS SHOW DECENT MOISTURE WITH CAPES OVER 1000
J/KG. SO REAL EMPHASIS WILL BE ON THE TRIGGER. 4KM SPC WRF SHOWS
GENERAL WARM SECTOR/AIRMASS DEVELOPMENT WITH MAIN FOCUS FURTHER WEST
IN CLOSER PROXIMITY TO THE COLD FRONT. 925 TEMPS WILL BE AROUND
20C... SOME LAKE COOLING POSSIBLE BUT NOT EXPECTING MUCH OF AN
INLAND PUSH WITH THAT...SO EXPECT HIGHS WELL INTO THE 70S WITH A FEW
LOW 80S.
.MONDAY NIGHT...FORECAST CONFIDENCE - MEDIUM.
RIGHT ENTRANCE REGION OF UPPER JET PASSES ACROSS SRN WI AS SFC CDFNT
MOVES ACROSS. PWAT VALUES WILL REMAIN IN THE 1.5 INCH RANGE AHEAD
OF THE FRONT WITH DEEP WARM CLOUD DEPTH AND MBE VELOCITY LESS THAN
10 KNOTS MOST OF THE NIGHT. 925-850MB MOISTURE FLUX CONVERGENCE
INCREASES ONCE AGAIN BUT DOES NOT REMAIN ORIENTATED WITH THE MEAN
STEERING FLOW. NEVER THE LESS...POTENTIAL FOR HEAVY RAINFALL WL
CONTINUE DURING THIS PD DUE TO STRONG FORCING AND DEEP MOISTURE.
.TUESDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE - HIGH.
SFC CDFNT WILL BE EXITING SOUTHEAST WISCONSIN EARLY TUESDAY MORNING.
LINGERING SHRA IN ITS WAKE SHOULD GRADUALLY DIMINISH FROM WEST TO
EAST AS COOLER...DRIER AIR SLOWLY WORKS ITS WAY ACROSS SRN WI AND
LOW LEVEL FRONTOGENETICAL FORCING SLIDES OFF TO THE EAST.
A QUIET AND COOL NIGHT IS EXPECTED TUESDAY NIGHT AS ANY INSTABILITY
-SHRA THAT WILL HAVE FORMED UPSTREAM IN THE AREA OF STEEP LOW TO MID
LEVEL LAPSE RATES SHOULD END WITH INSOLATION LOSS.
ON WEDNESDAY...MOST OF THE SHORT TERM GUIDANCE HINTING AT NEW SHORT
WAVE ROUNDING BASE OF LONG WAVE TROUGH OVER CENTRAL CONUS AND TAKING
NORTHEAST TRACK ALONG BAROCLINIC ZONE THROUGH TN AND OH VALLEY
REGION WED AND WED NGT. WL CONTINUE LOWER POPS FOR NOW WITH HIGHEST
IN THE SOUTHEAST WHERE PORTIONS OF SOUTHERN WI MAY BE ON THE
NORTHWEST SIDE OF THE EXPANDING PRECIP SHIELD WITH THIS SYSTEM.
.WEDNESDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE - MEDIUM.
BROADSCALE AGREEMENT IN THE MEDIUM RANGE GUIDANCE ON COOLER AIR
SETTLING INTO THE REGION AND LINGERING THROUGH THE END OF THE WEEK.
THIS WILL BE DUE TO LINGERING LONG WAVE TROUGH OVER CENTRAL CONUS
WHICH WILL BE SPREADING SLOWLY EWD THROUGH THE END OF THE WEEK. EWD
PROGRESSION OF TROUGH WL BE SLOWED BY WESTERN ATLANTIC BLOCKING
RIDGE. MID-UPPER LEVEL RIDGE AXIS EXPCD TO PERSIST OVER WI THROUGH
FRI. SHORT WAVE TROUGH APPROACHING PACIFIC NW WILL FINALLY NUDGE
TROF TO THE EAST OF WI FOR THE WEEKEND.
HENCE THE COOLER THAN NORMAL TEMPERATURES THAT WILL HAVE SETTLED
OVER SRN WI BY WED ARE EXPECTED TO LINGER INTO THE WEEKEND BEFORE
GRADUALLY WARMING. 85H TEMPS WL HAVE COOLED TO AROUND 0C BY WED AND
WL REMAIN A FEW DEGREES WITH 0C INTO SAT. IN ADDITION...WEAKER
SHORT WAVES ROTATING AROUND PARENT LONG WAVE TROUGH MAY BRING SOME
-SHRA TO SRN WI FROM WED THROUGH FRI. LAST SEVERAL RUNS OF THE
ECMWF HAVE BEEN SHOWING MORE POTENT LOW PRESSURE MOVING NORTHWARD
THROUGH TN/OH VALLEYS WED NGT INTO THU...WITH THE POTENTIAL FOR
PORTIONS OF SRN WI ON THE NORTHWEST WIDE OF THE -RA SHIELD FROM THIS
SYSTEM. CANADIAN AND GFS SHOW WEAKER RIPPLE AND ECMWF ENSEMBLE
FLATTENS THIS STRONGER SYSTEM AS WELL. HENCE FOR NOW WL CONTINUE
LOWER POPS FOR -SHRA WED NIGHT INTO THU.
EXPECTING MORE CLOUDS AND WEAK BOUNDARY LAYER MIXING TO KEEP
OVERNIGHT TEMPERATURES IN THE MIDDLE 30S TO LOWER 40S THURSDAY NIGHT
AND AGAIN FRIDAY NIGHT. HOWEVER IF MORE CLEARING IS EXPECTED IN
THESE PERIODS IN LATER FORECAST PERIODS...WL NEED TO CONSIDER ADDING
FROST TO THE LATE NIGHT FORECASTS.
&&
.AVIATION/12Z TAFS/...HRRR AND 4KM SPC WRF SHOW SOME ELEVATED STORMS
INTO SRN WI THIS AFTN/EVE WHICH LOOKS RIGHT ON GIVEN TRENDS IN 88-D.
LOOKING AT A BREAK A BIT LATER THIS EVE BEFORE POTENTIAL MCS ARRIVES
AFTER MIDNIGHT. THREAT THIS EVE LOOKS TO BE HAIL WITH DECENT MID
LEVEL LAPSE RATES. MORE DEVELOPMENT LIKELY TONIGHT AS LLJ REFOCUSES
TO OUR WEST AND THE LOW TO OUR WEST STRENGTHENS. NAM/GFS KEYING ON
IA/SE MN/ CNTRL/NRN WI THOUGH 12Z ECMWF/GEM AND HRRR SUGGEST STORMS
FOCUSED MORE INTO SRN WI. POTENTIAL FOR MORE SHRA/TSRA ON MONDAY
WITH WARM/HUMID/UNSTABLE AIRMASS THOUGH COLD FRONT STILL BACK TO OUR
WEST AND NOT EXPECTED TO ARRIVE UNTIL MONDAY NIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/MONDAY AND AVIATION/MARINE...PC
MONDAY NIGHT THROUGH SUNDAY...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1227 PM CDT SUN MAY 11 2014
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 245 AM CDT SUN MAY 11 2014
AXIS OF THE WEST COAST LONG WAVE TROUGH WILL SLIDE OVER THE PLAIN
STATES ON MON...SLOWLY EASING ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY ON WED. BITS OF UPPER LEVEL ENERGY WILL SPIN OUT OF THE
TROUGH...WITH THESE SHORTWAVES TAKING AIM ON THE REGION TODAY AND
MONDAY.
AT THE SFC...A WARM FRONT CURRENTLY WAS RUNNING FROM KS EASTWARD
THROUGH THE MID MISSISSIPPI RIVER VALLEY. THIS IS SLATED TO LIFT
NORTHWARD THROUGH THE DAY TODAY AS A SFC LOW TRACKS INTO IA BY 06Z
TONIGHT. STRONG LOW LEVEL MOISTURE TRANSPORT POINTS INTO AND ACROSS
THE WARM FRONT...DRIVEN BY A 40-50 KT 850 MB JET...AND NOSES INTO
NORTHEAST IA/SOUTHWEST WI BY 06Z. THIS RIBBON OF MOISTURE HOLDS
AHEAD OF A COLD FRONT THROUGH MONDAY...ALTHOUGH NOT NEARLY AS STRONG
AS WHAT IS EXPECTED FOR TONIGHT.
INSTABILITY CLIMBS THROUGH THE DAY...WITH 1000-2000 J/KG OF MUCAPE
STILL EXPECTED FOR MUCH OF THE LOCAL FORECAST AREA BY TONIGHT. IT
STAYS FAIRLY UNSTABLE THROUGH MONDAY...STILL AHEAD OF THE COLD FRONT
WITH THE WARM FRONT EXPECTED TO BE NORTH...SBCAPES AROUND 1500 J/KG.
A LOOK AT THE BUFKIT SOUNDINGS SHOWS THAT MUCH OF THAT CAPE IS OF
THE SKINNY VARIETY TONIGHT...MEANING THAT VIGOROUS UPDRAFTS/RAPID
DEVELOPMENT ARE NOT SUPPORTED BY THE INSTABILITY.
0-6 KM SHEAR RAMPS UP TO 40-50 KTS BY THIS EVENING...BUT A LOT OF
THAT IN THE 0-3 KM LAYER...AROUND 40 KTS OR SO. GOOD TURNING IN THE
LOWEST 1 KM PER BUFKIT HODOGRAPH...AND 0-1 KM SHEAR RANGES FROM 20-30
KTS DURING THE NIGHT.
SEVERE THREAT HAS CONTINUED TO INCREASE OVER THE PAST COUPLE
DAYS...AND 00Z MODELS ARE NO DIFFERENT. THE STRONG LOW LEVEL
JET/MOISTURE TRANSPORT WILL BE A SIGNIFICANT FACTOR...ALONG WITH THE
POSITIONING OF THE WARM FRONT. WHILE THE INSTABILITY IS NOT OVERLY
FAVORABLE...ADD IN THE VERY GOOD SHEAR AND STORM DEVELOPMENT IS
SUPPORTED. LARGE HAIL AND DAMAGING WINDS ARE THREATS...WINDS
ESPECIALLY IF THERE IS NO NEAR SFC STABLE LAYER. THE LOW LEVEL
CURVATURE/SHEAR ALSO BRINGS A TORNADO THREAT...ESPECIALLY AROUND THE
WARM FRONT WHICH WILL SERVE TO PROVIDE ADDITIONAL...LOCALIZED
VORTICITY. NAM12 SIG TOR PARAMETER AS HIGH AS 2-4 THIS EVENING FOR
NORTHEAST IA/SOUTHWEST WI.
ITS NOT CLEAR-CUT ON HOW HIGH THE RISK FOR SEVERE WILL BE...OR WHERE
IT WILL BE THE GREATEST. POSITIONING OF THE WARM FRONT WILL BE
SIGNIFICANT. GFS/NAM TRENDING TOWARD BRINGING THAT FRONT INTO
CENTRAL IA INTO NORTHERN ILL...ADVANCING NORTH DURING THE
EVENING...NEAR THE I-90 CORRIDOR/SOUTH AROUND 06Z. ITS NOT CERTAIN
IT WILL RUN THIS FAST NORTH AS CONVECTION ALONG AND NORTH OF THE
BOUNDARY SHOULD SERVE TO TEMPER ITS MOVEMENT.
IN ADDITION...THERE WILL BE A THREAT FOR SOME SHOWERS/STORMS THIS
AFTERNOON...WELL BEFORE THE EXPECTED CONVECTION OF TONIGHT. THE LOW
LEVEL JET IS EXPECTED TO SPARK A THUNDERSTORM COMPLEX OVER THE
SOUTHERN PLAINS...WHICH THE HRRR TAKES NORTHEAST TOWARD THE AREA.
HOW LONG THE CONVECTION WILL HOLD TOGETHER AS THE LOW LEVEL
JET/MOISTURE TRANSPORT TEMPORARILY WEAKENS AT MIDDAY IS IN QUESTION.
ITS MCV COULD SERVE AS FORCING MECHANISM LATER IN THE AFTERNOON. IF
THE PCPN DOESN/T REACH THE FORECAST AREA...DEBRIS CLOUDS PROBABLY
WILL...AND COULD TEMPER THE WARMING AND THUS INSTABILITY SOME NORTH
OF THE WARM FRONT.
ALL THIS SAID...SEE A SEVERE THREAT TONIGHT...ESPECIALLY ACROSS
NORTHEAST IA/SOUTHWEST WI. PROBABLY MORE MID/LATE EVENING. HAIL IS
THE TOP THREAT...BUT SIGNIFICANT 0-3 KM SHEAR COULD RESULT IN
DAMAGING WINDS IF THERE IS NOT A STRONG STABLE NEAR SFC LAYER.
BUFKIT SOUNDINGS SUGGEST THERE PROBABLY WON/T BE. AND...A TORNADO
THREAT CANNOT BE RULED OUT. LOW LEVEL CURVATURE AND 0-1 KM SHEAR
SUPPORTS IT...AND THE SIG TOR PARAMETER PEGS IT. ESPECIALLY
CONCERNED ABOUT ANY STORMS RIDING THE WARM FRONT. THERE ARE CAVEATS
TO THE RISK PER WHERE CONVECTION GOES...BOUNDARIES...ETC...BUT ITS A
SITUATION THAT NEEDS TO BE MONITORED VERY CLOSELY. EXPECTING WATCHES
AND WARNINGS TONIGHT.
ALL THAT SAID AND HAVEN/T EVEN TOUCHED ON THE HEAVY RAIN THREAT.
MORE ON THAT IN THE HYDROLOGY SECTION BELOW.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 245 AM CDT SUN MAY 11 2014
GFS/ECMWF PROMISE TO KEEP THE REGION UNDER THE INFLUENCE OF AN UPPER
LEVEL TROUGH FOR MUCH OF THE NEW WEEK. BITS OF ENERGY WILL MOVE
THROUGH THE TROUGH AND BRING A SHOWER THREAT FROM TIME TO
TIME...ALTHOUGH WHEN/WHERE THE RAIN CHANCES WILL BE ARE NOT
CERTAIN...WITH MODEL VARIANCES KEEPING CONFIDENCE LOW. WILL STAY
WITH CONSENSUS SOLUTION FOR CHANCES. TEMPERATURES ARE GOING TO TAKE A
TUMBLE DOWNWARD...WITH EC 850 MB TEMP ANOMALIES HOVERING AROUND -1.
HIGHS WILL STRUGGLE TO BREAK 60 DEGREES SOME DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1227 PM CDT SUN MAY 11 2014
MUCH OF THE NEXT 24 HRS WILL BE DOMINATED BY SHRA/TSRA IN AND AROUND
THE AREA. FIRST BAND OF MAINLY -SHRA WILL MOVE ACROSS THE TAF SITES
EARLY THIS AFTERNOON WITH LCL MVFR VSBYS IN THE -RA BUT CIGS MOSTLY
IN THE 5K-8KT FT RANGE. AREA LOOKS TO GET A BREAK FROM THE SHRA/TSRA
FOR THE MID AFTERNOON INTO EARLY EVENING HOURS AS THE MAIN FORCING
IS FOCUSED MORE INTO SOUTHERN/EASTERN IA. VFR CONDITIONS EXPECTED FOR
MUCH OF THE MID AFTERNOON TO EARLY EVENING HOURS. DEEPER MOISTURE
AND STRONGER FORCING/LIFT SPREAD BACK INTO THE AREA BY MID EVENING
WITH A BROAD AREA OF SHRA/TSRA EXPECTED TO OVERSPREAD THE TAF SITES
IN ROUGHLY THE 03Z-12Z TIME-FRAME. MAINLY VFR/MVFR CIGS/VSBYS
EXPECTED IN THE SHRA/TSRA WITH IFR CIGS/VSBYS IN +TSRA AND THE HEAVY
DOWNPOURS. THESE DO NOT LOOK TO PREVAIL AT THE TAF SITES...BUT 12 TO
18 HRS OUT THEY REMAIN DIFFICULT TO TIME THUS INCLUSION OF A LONGER
THAN DESIRED PERIOD TEMPO IFR CONDITIONS LATER TONIGHT. NOT A LOT OF
CONFIDENCE IN THE DETAILS FOR MON MORNING BUT APPEARS AREA WILL GET
A BREAK FROM THE HEAVIER/STRONGER/MORE WIDESPREAD TSRA. GIVEN THE
UNCERTAINTY...FOR NOW CARRIED 5SM -SHRA WITH CB THRU MON MORNING
&&
.HYDROLOGY...
ISSUED AT 245 AM CDT SUN MAY 11 2014
SIGNIFICANT LOW LEVEL MOISTURE TRANSPORT KICKS IN TONIGHT...AND
WHILE WEAKENING ON MONDAY...WILL CONTINUE TO FUEL SHOWERS AND
THUNDERSTORMS THROUGH MON NIGHT. PW/S CLIMB TO AROUND 1.5 INCHES.
EXPECT SOME STORMS OVER THE NEXT COUPLE DAYS TO PRODUCE HEAVY RAIN.
MODELS DROP 1-2 INCHES LATE TONIGHT INTO TUE FOR MUCH OF THE
FORECAST AREA. LOCALLY HIGHER AMOUNTS POSSIBLE. THE HEAVIEST RAIN
WILL FALL TONIGHT. DON/T EXPECT A WIDESPREAD FLOOD THREAT AT THE
MOMENT...BUT THERE COULD BE SOME LOCALIZED IMPACTS.
MEANWHILE...MINOR FLOODING/HIGH WATER CONTINUES ALONG PORTIONS OF
THE MISSISSIPPI RIVER. THE ADDITIONAL RAINS COULD HAVE IMPACTS ON
BOTH TRIBUTARIES AND THE MISSISSIPPI RIVER...SLOWING THE RATES OF
FALL...AND/OR PRODUCE ADDITIONAL RISES OR RENEWED FLOODING.
CHECK THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....RRS
HYDROLOGY....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1043 AM CDT SUN MAY 11 2014
.AVIATION/18Z TAFS/...CIRRUS CONTINUES TO ADVANCE ACROSS SRN WI
BLOWING OFF THE TOPS OF IOWA COMPLEX. THIS PRECIP WILL BE
OUTRUNNING THE LLJ AXIS WITH TIME TODAY. HRRR AND 4KM SPC WRF SHOW
SOME OF THE REMNANTS OF THIS AFFECTING SRN WI LATER TODAY.
STRONGEST STORMS PROGGD TO REMAIN SOUTH BUT WILL KEEP A CLOSE EYE
ON OUR SRN CNTYS AS THE SRN IA STORMS ADVANCE CLOSER. MORE
DEVELOPMENT LIKELY TONIGHT AS LLJ REFOCUSES TO OUR WEST AND THE
LOW TO OUR WEST STRENGTHENS. PROGS ARE KEYING ON IA/SE
MN/CNTRL/NRN WI THOUGH 00Z ECMWF SHOWED A MORE ORGANIZED WAA WING
DVLPG ACRS SRN WI TNT. WILL BE INTERESTING TO SEE HOW THE 12Z RUN
TRENDS. POTENTIAL FOR MORE SHRA/TSRA ON MONDAY WITH
WARM/HUMID/UNSTABLE AIRMASS THOUGH COLD FRONT STILL BACK TO OUR
WEST AND NOT EXPECTED TO ARRIVE UNTIL MONDAY NIGHT.
PC
&&
.PREV DISCUSSION... /ISSUED 332 AM CDT SUN MAY 11 2014/
TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
UPPER LEVEL RIDGING OCCURS TODAY AND INTO TONIGHT AHEAD OF THE
STRONG WESTERN TROUGH MOVING ACROSS THE ROCKIES. ONE JET MAX OVER
THE UPPER GREAT LAKES MOVES OFF TO THE EAST TODAY AS THE STRONGER
JET ASSOCIATED WITH THE WESTERN TROUGH BEGINS TO ROUND THE BASE OF
THE TROUGH THIS MORNING...AND MOVES NORTHEAST OVER THE EASTERN
SECTION OF THE TROUGH TONIGHT. UPPER DIVERGENCE INCREASES THIS
AFTERNOON OVER SOUTHERN WISCONSIN WITH THE DIVERGENCE INCREASING TO
RATHER STRONG VALUES TONIGHT. 850/700 MB DEW POINTS INCREASE TODAY
WITH 850 MB DEWPOINTS RISING TO 14 CELSIUS THIS EVENING UNTIL THE
CONVECTION OCCURS.
700 MB WINDS INCREASE THIS AFTERNOON AND AGAIN LATE TONIGHT REACHING
40 KNOTS. AT 850 MB WINDS INCREASE LATER THIS EVENING AS A 55 KNOT
LOW LEVEL JET APPROACHES FROM MISSOURI. SOUTHERN WISCONSIN REMAINS
IN THE NOSE OF THE JET THROUGH THE EARLY MORNING MONDAY. AS A
RESULT 850 MB MOISTURE CONVERGENCE INCREASES.
THIS SHOULD SET THE STAGE FOR AN MCS NORTH OF THE ADVANCING WARM
FRONT. EXPECT THUNDERSTORMS TONIGHT...SOME WITH HEAVY RAINFALL...
ALONG WITH A LARGE HAIL POTENTIAL GIVEN THE 1500 JOULES/KG OF
ELEVATED CAPE WITH THE EQUILIBRIUM LEVEL UP TO 36 THSD FT. WET BULB
ZERO IS AROUND 10 THSD FT...BUT LOW LEVELS SHOULD BE RATHER COOL
NORTH OF THE WARM FRONT. LOCAL SEVERE PROBABILITY CWASP VALUES
INCREASE TO 80 PCT INTO PORTIONS OF SOUTH CENTRAL WISCONSIN
BY EARLY MONDAY MORNING ON THE NAM AND GFS.
THERE WILL BE A CHANCE FOR THUNDERSTORMS EVEN THIS AFTERNOON WITH
CAPE VALUES AROUND 1000 JOULES/KG AS THE 850/700 MB MOISTURE
INCREASES.
MONDAY AND TUESDAY...FORECAST CONFIDENCE...MEDIUM
SHOWERS AND THUNDERSTORMS WILL BE LIKELY AGAIN MONDAY AND MONDAY
NIGHT...LINGERING ALSO INTO TUESDAY. THE BIGGEST ISSUE MON/TUE IS
THE LOW TRACK AND TIMING...WHICH WILL PLAY A BIG ROLE IN STORM
TIMING AND SEVERE POTENTIAL. UNFORTUNATELY...MODELS HAVE DIVERGED
A BIT MORE WITH THE TRACK OF THE SFC LOW IN THE LATEST RUNS. BY
TUESDAY MORNING...THE CENTER OF THE SFC LOW IS RIGHT OVER THE
FORECAST AREA VIA THE ECMWF...NEAR MINNEAPOLIS VIA THE NAM...AND
JUST NORTH OF MINNESOTA VIA THE CANADIAN AND GFS SOLUTIONS. TOOK A
BLEND OF THE LOW TRACKS FOR NOW...BRINGING THE COLD FRONT THROUGH
BY TUESDAY MORNING. THE QUICKER SOLUTIONS WOULD LIKE POSE A
GREATER SEVERE WEATHER THREAT MONDAY...WITH THE COLD FRONT CLOSER
TO THE FORECAST AREA BY THE END OF PEAK HEATING. SPC HAS
MAINTAINED A SLIGHT RISK OF SEVERE STORMS FOR THE ENTIRE FORECAST
AREA.
TEMPERATURES MONDAY AND TUESDAY WILL ALSO BE DEPENDENT ON THE
TIMING OF THE LOW...AS A SLOWER SOLUTION WILL LIKELY ALLOW MORE A
CHANCE FOR A LITTLE FILTERED SUNSHINE MONDAY. WITH 925 MB TEMPS
PEAKING IN THE 19-22C RANGE...IT WOULD NOT TAKE MUCH HEATING FOR
TEMPS TO SHOOT UP AROUND 80...ESPECIALLY IN THE SOUTHEAST. DECIDED
TO BUMP TEMPS UP A TAD FROM THE PREVIOUS FORECAST. A SLOWER
SOLUTION WOULD ALSO RESULT IN SOMEWHAT MILDER TEMPS AT LEAST
THROUGH TUESDAY MORNING...SO ALSO BUMPED TUESDAY HIGHS UP A
LITTLE.
WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE...MEDIUM
A RETURN TO THE BELOVED NORTHWEST FLOW PATTERN WILL LIKELY RESULT
IN BELOW NORMAL TEMPERATURES FOR WEDNESDAY THROUGH THE END OF THE
WEEK. ADDITIONALLY...A SERIES OF SHORTWAVES WITHIN THE FLOW WILL
BRING A GOOD AMOUNT OF CLOUDS ALONG WITH A CHANCE FOR SHOWERS MOST
DAYS. SO...ENJOY THE MILDER TEMPERATURES WHILE THEY ARE STILL
HERE.
AVIATION/12Z TAFS/...
MAINLY VFR CONDITIONS TODAY WITH MID LEVEL CLOUDS INCREASING WITH
ADVANCING MOISTURE AHEAD OF A WEAK TROUGH OVER THE UPPER
MISSISSIPPI VALLEY...AND NORTH OF AN ADVANCING WARM FRONT AHEAD OF
STRONG LOW PRESSURE MOVING OUT OF THE TEXAS PAN HANDLE REGION.
SOME CUMULUS EXPECTED THIS AFTERNOON ALONG WITH A CHANCE OF
THUNDERSTORMS..
THE WARM FRONT WILL REACH SOUTHERN WISCONSIN TONIGHT...INCREASING
THE THUNDERSTORMS. SOME MAY PRODUCE HAIL. LOOK FOR MVFR AND IFR
CONDITIONS TO DEVELOP NEAR THE WARM FRONT LATER THIS EVENING AND
LATE TONIGHT.
MARINE...
LIGHT SOUTHEAST WINDS TODAY AHEAD OF AN ADVANCING WARM FRONT. THE
WARM FRONT WILL MOVE NORTH LATER TONIGHT AND REACH NORTHEAST
WISCONSIN LATER MONDAY. LOOK FOR A CHANCE OF THUNDERSTORMS THIS
AFTERNOON WITH PERIODS OF THUNDERSTORMS TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
MONDAY THROUGH SATURDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
624 AM CDT SUN MAY 11 2014
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 245 AM CDT SUN MAY 11 2014
AXIS OF THE WEST COAST LONG WAVE TROUGH WILL SLIDE OVER THE PLAIN
STATES ON MON...SLOWLY EASING ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY ON WED. BITS OF UPPER LEVEL ENERGY WILL SPIN OUT OF THE
TROUGH...WITH THESE SHORTWAVES TAKING AIM ON THE REGION TODAY AND
MONDAY.
AT THE SFC...A WARM FRONT CURRENTLY WAS RUNNING FROM KS EASTWARD
THROUGH THE MID MISSISSIPPI RIVER VALLEY. THIS IS SLATED TO LIFT
NORTHWARD THROUGH THE DAY TODAY AS A SFC LOW TRACKS INTO IA BY 06Z
TONIGHT. STRONG LOW LEVEL MOISTURE TRANSPORT POINTS INTO AND ACROSS
THE WARM FRONT...DRIVEN BY A 40-50 KT 850 MB JET...AND NOSES INTO
NORTHEAST IA/SOUTHWEST WI BY 06Z. THIS RIBBON OF MOISTURE HOLDS
AHEAD OF A COLD FRONT THROUGH MONDAY...ALTHOUGH NOT NEARLY AS STRONG
AS WHAT IS EXPECTED FOR TONIGHT.
INSTABILITY CLIMBS THROUGH THE DAY...WITH 1000-2000 J/KG OF MUCAPE
STILL EXPECTED FOR MUCH OF THE LOCAL FORECAST AREA BY TONIGHT. IT
STAYS FAIRLY UNSTABLE THROUGH MONDAY...STILL AHEAD OF THE COLD FRONT
WITH THE WARM FRONT EXPECTED TO BE NORTH...SBCAPES AROUND 1500 J/KG.
A LOOK AT THE BUFKIT SOUNDINGS SHOWS THAT MUCH OF THAT CAPE IS OF
THE SKINNY VARIETY TONIGHT...MEANING THAT VIGOROUS UPDRAFTS/RAPID
DEVELOPMENT ARE NOT SUPPORTED BY THE INSTABILITY.
0-6 KM SHEAR RAMPS UP TO 40-50 KTS BY THIS EVENING...BUT A LOT OF
THAT IN THE 0-3 KM LAYER...AROUND 40 KTS OR SO. GOOD TURNING IN THE
LOWEST 1 KM PER BUFKIT HODO...AND 0-1 KM SHEAR RANGES FROM 20-30
KTS DURING THE NIGHT.
SEVERE THREAT HAS CONTINUED TO INCREASE OVER THE PAST COUPLE
DAYS...AND 00Z MODELS ARE NO DIFFERENT. THE STRONG LOW LEVEL
JET/MOISTURE TRANSPORT WILL BE A SIGNIFICANT FACTOR...ALONG WITH THE
POSITIONING OF THE WARM FRONT. WHILE THE INSTABILITY IS NOT OVERLY
FAVORABLE...ADD IN THE VERY GOOD SHEAR AND STORM DEVELOPMENT IS
SUPPORTED. LARGE HAIL AND DAMAGING WINDS ARE THREATS...WINDS
ESPECIALLY IF THERE IS NO NEAR SFC STABLE LAYER. THE LOW LEVEL
CURVATURE/SHEAR ALSO BRINGS A TORNADO THREAT...ESPECIALLY AROUND THE
WARM FRONT WHICH WILL SERVE TO PROVIDE ADDITIONAL...LOCALIZED
VORTICITY. NAM12 SIG TOR PARAMETER AS HIGH AS 2-4 THIS EVENING FOR
NORTHEAST IA/SOUTHWEST WI.
ITS NOT CLEAR-CUT ON HOW HIGH THE RISK FOR SEVERE WILL BE...OR WHERE
IT WILL BE THE GREATEST. POSITIONING OF THE WARM FRONT WILL BE
SIGNIFICANT. GFS/NAM TRENDING TOWARD BRINGING THAT FRONT INTO
CENTRAL IA INTO NORTHERN ILL...ADVANCING NORTH DURING THE
EVENING...NEAR THE I-90 CORRIDOR/SOUTH AROUND 06Z. ITS NOT CERTAIN
IT WILL RUN THIS FAST NORTH AS CONVECTION ALONG AND NORTH OF THE
BOUNDARY SHOULD SERVE TO TEMPER ITS MOVEMENT.
IN ADDITION...THERE WILL BE A THREAT FOR SOME SHOWERS/STORMS THIS
AFTERNOON...WELL BEFORE THE EXPECTED CONVECTION OF TONIGHT. THE LOW
LEVEL JET IS EXPECTED TO SPARK A THUNDERSTORM COMPLEX OVER THE
SOUTHERN PLAINS...WHICH THE HRRR TAKES NORTHEAST TOWARD THE AREA.
HOW LONG THE CONVECTION WILL HOLD TOGETHER AS THE LOW LEVEL
JET/MOISTURE TRANSPORT TEMPORARILY WEAKENS AT MIDDAY IS IN QUESTION.
ITS MCV COULD SERVE AS FORCING MECHANISM LATER IN THE AFTERNOON. IF
THE PCPN DOESN/T REACH THE FORECAST AREA...DEBRIS CLOUDS PROBABLY
WILL...AND COULD TEMPER THE WARMING AND THUS INSTABILITY SOME NORTH
OF THE WARM FRONT.
ALL THIS SAID...SEE A SEVERE THREAT TONIGHT...ESPECIALLY ACROSS
NORTHEAST IA/SOUTHWEST WI. PROBABLY MORE MID/LATE EVENING. HAIL IS
THE TOP THREAT...BUT SIGNIFICANT 0-3 KM SHEAR COULD RESULT IN
DAMAGING WINDS IF THERE IS NOT A STRONG STABLE NEAR SFC LAYER.
BUFKIT SOUNDINGS SUGGEST THERE PROBABLY WON/T BE. AND...A TORNADO
THREAT CANNOT BE RULED OUT. LOW LEVEL CURVATURE AND 0-1 KM SHEAR
SUPPORTS IT...AND THE SIG TOR PARAMETER PEGS IT. ESPECIALLY
CONCERNED ABOUT ANY STORMS RIDING THE WARM FRONT. THERE ARE CAVEATS
TO THE RISK PER WHERE CONVECTION GOES...BOUNDARIES...ETC...BUT ITS A
SITUATION THAT NEEDS TO BE MONITORED VERY CLOSELY. EXPECTING WATCHES
AND WARNINGS TONIGHT.
ALL THAT SAID AND HAVEN/T EVEN TOUCHED ON THE HEAVY RAIN THREAT.
MORE ON THAT IN THE HYDROLOGY SECTION BELOW.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 245 AM CDT SUN MAY 11 2014
GFS/ECMWF PROMISE TO KEEP THE REGION UNDER THE INFLUENCE OF AN UPPER
LEVEL TROUGH FOR MUCH OF THE NEW WEEK. BITS OF ENERGY WILL MOVE
THROUGH THE TROUGH AND BRING A SHOWER THREAT FROM TIME TO
TIME...ALTHOUGH WHEN/WHERE THE RAIN CHANCES WILL BE ARE NOT
CERTAIN...WITH MODEL VARIANCES KEEPING CONFIDENCE LOW. WILL STAY
WITH CONSENSUS SOLUTION FOR CHANCES. TEMPERATURES ARE GOING TO TAKE A
TUMBLE DOWNWARD...WITH EC 850 MB TEMP ANOMALIES HOVERING AROUND -1.
HIGHS WILL STRUGGLE TO BREAK 60 DEGREES SOME DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 624 AM CDT SUN MAY 11 2014
ACTIVE WEATHER OVER THE NEXT 24 HOURS WITH THUNDERSTORMS MOVING IN
THIS AFTERNOON...LASTING THROUGH TONIGHT. LOOK FOR VFR CONDITIONS
THROUGH THIS MORNING WITH A FEW -SHRA MOVING OUT OF THE PLAINS
INTO THE AREA IN THE 16-18Z TIMEFRAME. THEN LOOKING FOR SCATTERED
TSRA DEVELOPING THIS AFTERNOON WITH DAYTIME HEATING AND AS A WARM
FRONT PUSHES NORTH TOWARD THE AREA FROM THE PLAINS. LOOK FOR
THUNDERSTORMS TO INCREASE IN COVERAGE AND INTENSITY THIS EVENING
THROUGH THE OVERNIGHT HOURS AS THE WARM FRONT PROGRESSES NORTHWARD
INTO THE REGION. A FEW OF THESE STORMS MAY TURN SEVERE. OTHERWISE...
EXPECTING CONDITIONS TO DETERIORATE INTO MVFR/IFR THIS EVENING
AND OVERNIGHT WITH THE THUNDERSTORM ACTIVITY.
&&
.HYDROLOGY...
ISSUED AT 245 AM CDT SUN MAY 11 2014
SIGNIFICANT LOW LEVEL MOISTURE TRANSPORT KICKS IN TONIGHT...AND
WHILE WEAKENING ON MONDAY...WILL CONTINUE TO FUEL SHOWERS AND
THUNDERSTORMS THROUGH MON NIGHT. PW/S CLIMB TO AROUND 1.5 INCHES.
EXPECT SOME STORMS OVER THE NEXT COUPLE DAYS TO PRODUCE HEAVY RAIN.
MODELS DROP 1-2 INCHES LATE TONIGHT INTO TUE FOR MUCH OF THE
FORECAST AREA. LOCALLY HIGHER AMOUNTS POSSIBLE. THE HEAVIEST RAIN
WILL FALL TONIGHT. DON/T EXPECT A WIDESPREAD FLOOD THREAT AT THE
MOMENT...BUT THERE COULD BE SOME LOCALIZED IMPACTS.
MEANWHILE...MINOR FLOODING/HIGH WATER CONTINUES ALONG PORTIONS OF
THE MISSISSIPPI RIVER. THE ADDITIONAL RAINS COULD HAVE IMPACTS ON
BOTH TRIBUTARIES AND THE MISSISSIPPI RIVER...SLOWING THE RATES OF
FALL...AND/OR PRODUCE ADDITIONAL RISES OR RENEWED FLOODING.
CHECK THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...DAS
HYDROLOGY....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
245 AM CDT SUN MAY 11 2014
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 245 AM CDT SUN MAY 11 2014
AXIS OF THE WEST COAST LONG WAVE TROUGH WILL SLIDE OVER THE PLAIN
STATES ON MON...SLOWLY EASING ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY ON WED. BITS OF UPPER LEVEL ENERGY WILL SPIN OUT OF THE
TROUGH...WITH THESE SHORTWAVES TAKING AIM ON THE REGION TODAY AND
MONDAY.
AT THE SFC...A WARM FRONT CURRENTLY WAS RUNNING FROM KS EASTWARD
THROUGH THE MID MISSISSIPPI RIVER VALLEY. THIS IS SLATED TO LIFT
NORTHWARD THROUGH THE DAY TODAY AS A SFC LOW TRACKS INTO IA BY 06Z
TONIGHT. STRONG LOW LEVEL MOISTURE TRANSPORT POINTS INTO AND ACROSS
THE WARM FRONT...DRIVEN BY A 40-50 KT 850 MB JET...AND NOSES INTO
NORTHEAST IA/SOUTHWEST WI BY 06Z. THIS RIBBON OF MOISTURE HOLDS
AHEAD OF A COLD FRONT THROUGH MONDAY...ALTHOUGH NOT NEARLY AS STRONG
AS WHAT IS EXPECTED FOR TONIGHT.
INSTABILITY CLIMBS THROUGH THE DAY...WITH 1000-2000 J/KG OF MUCAPE
STILL EXPECTED FOR MUCH OF THE LOCAL FORECAST AREA BY TONIGHT. IT
STAYS FAIRLY UNSTABLE THROUGH MONDAY...STILL AHEAD OF THE COLD FRONT
WITH THE WARM FRONT EXPECTED TO BE NORTH...SBCAPES AROUND 1500 J/KG.
A LOOK AT THE BUFKIT SOUNDINGS SHOWS THAT MUCH OF THAT CAPE IS OF
THE SKINNY VARIETY TONIGHT...MEANING THAT VIGOROUS UPDRAFTS/RAPID
DEVELOPMENT ARE NOT SUPPORTED BY THE INSTABILITY.
0-6 KM SHEAR RAMPS UP TO 40-50 KTS BY THIS EVENING...BUT A LOT OF
THAT IN THE 0-3 KM LAYER...AROUND 40 KTS OR SO. GOOD TURNING IN THE
LOWEST 1 KM PER BUFKIT HODO...AND 0-1 KM SHEAR RANGES FROM 20-30
KTS DURING THE NIGHT.
SEVERE THREAT HAS CONTINUED TO INCREASE OVER THE PAST COUPLE
DAYS...AND 00Z MODELS ARE NO DIFFERENT. THE STRONG LOW LEVEL
JET/MOISTURE TRANSPORT WILL BE A SIGNIFICANT FACTOR...ALONG WITH THE
POSITIONING OF THE WARM FRONT. WHILE THE INSTABILITY IS NOT OVERLY
FAVORABLE...ADD IN THE VERY GOOD SHEAR AND STORM DEVELOPMENT IS
SUPPORTED. LARGE HAIL AND DAMAGING WINDS ARE THREATS...WINDS
ESPECIALLY IF THERE IS NO NEAR SFC STABLE LAYER. THE LOW LEVEL
CURVATURE/SHEAR ALSO BRINGS A TORNADO THREAT...ESPECIALLY AROUND THE
WARM FRONT WHICH WILL SERVE TO PROVIDE ADDITIONAL...LOCALIZED
VORTICITY. NAM12 SIG TOR PARAMETER AS HIGH AS 2-4 THIS EVENING FOR
NORTHEAST IA/SOUTHWEST WI.
ITS NOT CLEAR-CUT ON HOW HIGH THE RISK FOR SEVERE WILL BE...OR WHERE
IT WILL BE THE GREATEST. POSITIONING OF THE WARM FRONT WILL BE
SIGNIFICANT. GFS/NAM TRENDING TOWARD BRINGING THAT FRONT INTO
CENTRAL IA INTO NORTHERN ILL...ADVANCING NORTH DURING THE
EVENING...NEAR THE I-90 CORRIDOR/SOUTH AROUND 06Z. ITS NOT CERTAIN
IT WILL RUN THIS FAST NORTH AS CONVECTION ALONG AND NORTH OF THE
BOUNDARY SHOULD SERVE TO TEMPER ITS MOVEMENT.
IN ADDITION...THERE WILL BE A THREAT FOR SOME SHOWERS/STORMS THIS
AFTERNOON...WELL BEFORE THE EXPECTED CONVECTION OF TONIGHT. THE LOW
LEVEL JET IS EXPECTED TO SPARK A THUNDERSTORM COMPLEX OVER THE
SOUTHERN PLAINS...WHICH THE HRRR TAKES NORTHEAST TOWARD THE AREA.
HOW LONG THE CONVECTION WILL HOLD TOGETHER AS THE LOW LEVEL
JET/MOISTURE TRANSPORT TEMPORARILY WEAKENS AT MIDDAY IS IN QUESTION.
ITS MCV COULD SERVE AS FORCING MECHANISM LATER IN THE AFTERNOON. IF
THE PCPN DOESN/T REACH THE FORECAST AREA...DEBRIS CLOUDS PROBABLY
WILL...AND COULD TEMPER THE WARMING AND THUS INSTABILITY SOME NORTH
OF THE WARM FRONT.
ALL THIS SAID...SEE A SEVERE THREAT TONIGHT...ESPECIALLY ACROSS
NORTHEAST IA/SOUTHWEST WI. PROBABLY MORE MID/LATE EVENING. HAIL IS
THE TOP THREAT...BUT SIGNIFICANT 0-3 KM SHEAR COULD RESULT IN
DAMAGING WINDS IF THERE IS NOT A STRONG STABLE NEAR SFC LAYER.
BUFKIT SOUNDINGS SUGGEST THERE PROBABLY WON/T BE. AND...A TORNADO
THREAT CANNOT BE RULED OUT. LOW LEVEL CURVATURE AND 0-1 KM SHEAR
SUPPORTS IT...AND THE SIG TOR PARAMETER PEGS IT. ESPECIALLY
CONCERNED ABOUT ANY STORMS RIDING THE WARM FRONT. THERE ARE CAVEATS
TO THE RISK PER WHERE CONVECTION GOES...BOUNDARIES...ETC...BUT ITS A
SITUATION THAT NEEDS TO BE MONITORED VERY CLOSELY. EXPECTING WATCHES
AND WARNINGS TONIGHT.
ALL THAT SAID AND HAVEN/T EVEN TOUCHED ON THE HEAVY RAIN THREAT.
MORE ON THAT IN THE HYDROLOGY SECTION BELOW.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 245 AM CDT SUN MAY 11 2014
GFS/ECMWF PROMISE TO KEEP THE REGION UNDER THE INFLUENCE OF AN UPPER
LEVEL TROUGH FOR MUCH OF THE NEW WEEK. BITS OF ENERGY WILL MOVE
THROUGH THE TROUGH AND BRING A SHOWER THREAT FROM TIME TO
TIME...ALTHOUGH WHEN/WHERE THE RAIN CHANCES WILL BE ARE NOT
CERTAIN...WITH MODEL VARIANCES KEEPING CONFIDENCE LOW. WILL STAY
WITH CONSENSUS SOLUTION FOR CHANCES. TEMPERATURES ARE GOING TO TAKE A
TUMBLE DOWNWARD...WITH EC 850 MB TEMP ANOMALIES HOVERING AROUND -1.
HIGHS WILL STRUGGLE TO BREAK 60 DEGREES SOME DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT
1149 PM CDT SAT MAY 10 2014
SOME SCATTERED RAIN SHOWERS HAVE DEVELOPED ACROSS SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN AND WILL TRACK QUICKLY TO THE EAST
OVERNIGHT. CONDITIONS ARE MAINLY VFR THOUGH A FEW SPOTS HAVE BRIEFLY
DROPPED TO MVFR WITH VISIBILITY GOING DOWN TO 5SM. BASED ON THE LOW
CHANCES THAT ONE OF THESE SHOWERS WOULD DIRECTLY HIT RST/LSE...HAVE
JUST LEFT IT AS VCSH AND VFR.
THE MAIN FOCUS THEN GOES TO TOMORROW EVENING WHEN IT APPEARS LIKELY
THAT WIDESPREAD THUNDERSTORMS WILL DEVELOP ACROSS THE REGION AS A
WARM FRONT LIFTS NORTH INTO THE REGION. THERE IS SOME QUESTION ABOUT
THE EXACT START UP TIME OF THE CONVECTION...BUT IT APPEARS MOST
LIKELY TO OCCUR AROUND 2Z AT RST AND 4Z AT LSE. VISIBILITY SHOULD
DROP TO IFR OR LOWER IF THE STORMS TRAIN OVER THE SAME LOCATIONS
TOMORROW EVENING. BASED ON THE HIGH CONFIDENCE THAT WE WILL HAVE
RAINS/STORMS...HAVE PUT A PREVAILING TSRA GROUP IN THE TAFS FOR
TOMORROW EVENING.
&&
.HYDROLOGY...
ISSUED AT 245 AM CDT SUN MAY 11 2014
SIGNIFICANT LOW LEVEL MOISTURE TRANSPORT KICKS IN TONIGHT...AND
WHILE WEAKENING ON MONDAY...WILL CONTINUE TO FUEL SHOWERS AND
THUNDERSTORMS THROUGH MON NIGHT. PW/S CLIMB TO AROUND 1.5 INCHES.
EXPECT SOME STORMS OVER THE NEXT COUPLE DAYS TO PRODUCE HEAVY RAIN.
MODELS DROP 1-2 INCHES LATE TONIGHT INTO TUE FOR MUCH OF THE
FORECAST AREA. LOCALLY HIGHER AMOUNTS POSSIBLE. THE HEAVIEST RAIN
WILL FALL TONIGHT. DON/T EXPECT A WIDESPREAD FLOOD THREAT AT THE
MOMENT...BUT THERE COULD BE SOME LOCALIZED IMPACTS.
MEANWHILE...MINOR FLOODING/HIGH WATER CONTINUES ALONG PORTIONS OF
THE MISSISSIPPI RIVER. THE ADDITIONAL RAINS COULD HAVE IMPACTS ON
BOTH TRIBUTARIES AND THE MISSISSIPPI RIVER...SLOWING THE RATES OF
FALL...AND/OR PRODUCE ADDITIONAL RISES OR RENEWED FLOODING.
CHECK THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....HALBACH
HYDROLOGY....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CDT SAT MAY 10 2014
.UPDATE...
ISSUED AT 834 PM CDT SAT MAY 10 2014
MAIN BAND OF RAIN IS ENTERING EASTERN MINNESOTA AND IOWA ALONG THE
LEAD MID LEVEL SHORT WAVE TROUGH THAT RUNS FROM SOUTHEAST NORTH
DAKOTA THROUGH SOUTHWEST MINNESOTA. THE 11.00Z RAP CONTINUES TO
SHOW A WEAKENING TREND IN INSTABILITY...BUT STILL HAS SOME FEEDING
INTO THE BACK EDGE OF THE SHORT WAVE TO WARRANT KEEPING A MENTION
OF THUNDER IN THROUGH THIS EVENING. HAVE SPED UP THE END TIME OF
THIS RAIN BASED ON CURRENT EXTRAPOLATION AND THE PAST FEW RUNS OF
THE HRRR WHICH HAS HAD A GOOD HANDLE ON THIS CONVECTION. WHILE
0-6KM WIND SHEAR IS DECENT...IT IS ALL IN THE LOW LEVELS AND NOT
IN THE LAYER WHERE THIS VERY SKINNY/WEAK INSTABILITY IS IN THE MID
LEVELS. THUS...AM NOT EXPECTING ANYTHING SEVERE THIS EVENING.
HAVE NOT MADE ANY CHANGES TO THE FORECAST FOR TOMORROW...BUT AS
PREVIOUSLY MENTIONED...IT WILL ALL DEPEND ON HOW FAR NORTH THE
WARM FRONT MAKES IT. ONE THING APPEARS CERTAIN AND THAT IS THE
INCREASE IN LOW LEVEL MOISTURE TRANSPORT THROUGH THE DAY AND INTO
THE NIGHT WHICH MAY LEAD TO SOME FLOODING ISSUES IF STORMS TRAIN
TO THE NORTH OF THE FRONT. WILL HAVE TO SEE HOW THE 11.00Z MODELS
COME UP BEFORE MAKING ANY WHOLESALE CHANGES TO THE FORECAST.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 310 PM CDT SAT MAY 10 2014
MAIN FORECAST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES THIS EVENING
AND AGAIN SUN AFTERNOON/NIGHT. POTENTIAL HEAVY RAINS SUN NIGHT.
18Z DATA ANALYSIS HAD A WEAK RIDGE OF HIGH PRESSURE FROM NORTHEAST
MN THRU SOUTHEAST WI. SUNNY...QUIET DAY OVER THE NORTHEAST HALF OF
THE REGION. WV IMAGERY SHOWED A MORE ROBUST LOOKING SHORTWAVE
LIFTING NORTHEAST ACROSS SD/NEB EARLY THIS AFTERNOON. THIS WAVE AND
SOME 850-700MB MOISTURE TRANSPORT/THERMO-DYNAMIC FORCING RESPONSIBLE
FOR A BROAD BAND OF SCT SHRA/ISOLATED TSRA LIFTING ACROSS NORTHERN
IA/SOUTHWEST MN. PER 10.12Z KMPX SOUNDING...PLENTY OF DRY AIR ABOVE
850MB AHEAD OF THIS BAND OF SHRA/TSRA TO OVERCOME BEFORE PRECIP
REACHES THE GROUND...AND MOST RAIN AMOUNTS SO FAR TODAY HAVE BEEN A
TRACE TO A FEW HUNDREDTHS OF AN INCH.
10.12Z MODELS INITIALIZED WELL...BUT FOR GFS ABOUT 5F HIGH ON SFC
DEW POINTS ACROSS THE SOUTH HALF OF THE UPPER MS VALLEY.
SOLUTIONS CONTINUE TO OFFER A TIGHTER CONSENSUS ON THE SHORTWAVE
TO LIFT ACROSS THE UPPER MIDWEST TONIGHT AND THE NEXT STRONG
TROUGHING/ ENERGY TO CROSS THE ROCKIES SUN/SUN NIGHT.
SLOWER/STRONGER ECMWF/ CAN-GEM OFFERING THE BETTER RUN-TO-RUN
CONSISTENCY WITH THE ROCKIES TROUGHING LATE SUN/SUN NIGHT WITH
GFS/NAM SLOWING TO MATCH UP. NAM APPEARS AS BIT OF AN OUTLIER AT
12Z MON WITH A FURTHER NORTH/EAST SFC LOW/TRAILING COLD FRONT AND
ITS SOLUTION GENERALLY DISCOUNTED. GIVEN THE NOW RATHER TIGHT NON-
NAM CONSENSUS THRU 12Z MON...SHORT- TERM FCST CONFIDENCE FOR A
RATHER ACTIVE PERIOD IS GOOD THIS CYCLE.
FIRST SHORTWAVE CROSSING THE UPPER MIDWEST TONIGHT WEAKENS AS
LOOSES THE BATTLE WITH THE RISING HGTS/RIDGING AHEAD OF THE
STRONGER TROUGHING DIGGING INTO THE ROCKIES. 925-700MB MOISTURE
TRANSPORT/ WARM ADVECTION AND SOME 295-305K ISENTROPIC LIFT STILL
SPREADS NORTHEAST ACROSS THE FCST AREA MAINLY LATE THIS
AFTERNOON/EVENING... WITH STEEPER MID LEVEL LAPSE RATES AND WEAK
INSTABILITY. WILL CONTINUE SHRA/TSRA CHANCES THRU THE EVENING...IN
THE 20-50 PERCENT RANGE...THEN TAPER/END THEM AFTER MIDNIGHT AS
THE LOWER LEVEL FORCING WEAKENS/MOVES EAST OF THE FCST AREA. MOST
RAIN AMOUNTS TONIGHT TO BE QUITE LIGHT.
BREAK FROM THE RAIN CHANCES LATE TONIGHT/SUN MORNING AS SOME 850-
700MB DRYING TEMPORARILY SPREADS ACROSS THE AREA. MOISTURE RETURN
AHEAD OF THE CENTRAL PLAINS LEE LOW ALREADY SPREAD ACROSS THE AREA
SUN MORNING...WITH THE 700MB MOISTURE ARRIVING DURING THE LATER
MORNING/EARLY AFTERNOON HOURS AND 925-50MB MOISTURE ARRIVING DURING
THE AFTERNOON. PW VALUES OF AROUND 1.5 INCHES TO SPREAD NORTH ACROSS
THE AREA FOR SUN AFTERNOON/NIGHT. QUESTION NO LONGER SEEMS IF ITS
GOING TO RAIN LATE SUN AFTERNOON/NIGHT BUT HOW MUCH. BROAD/DEEP
LAYERED FORCING/LIFT AHEAD OF THE SFC THRU MID LEVEL TROUGH SPREADS
ACROSS WITH THE MOISTURE INCREASE SUN AFTERNOON/NIGHT.
AT 00Z MON...MODEL SOUNDINGS SHOWING STABILITY/CIN OF 50-150IN THE
SFC-700MB LAYER WITH MUCAPES OF 500-1500 J/KG OVER MAINLY THE SOUTH
1/3 OF THE FCST AREA. LFC AROUND 700MB IN THE SOUNDINGS WITH THE CIN
IN A RATHER DEEP 900-700MB LAYER. CAPE PROFILE IS DEEP...BUT SKINNY.
WITH WARM CLOUD DEPTH OF AROUND 3500 METERS...THE SKINNY CAPE OF 500-
1500 J/KG DOES NOT SEEM LIKE ENOUGH FOR A BIG HAIL THREAT. WITH THE
AREA LOOKING TO BE NORTH OF THE WARM FRONT SUN EVENING AND THE CIN
BELOW 700MB...APPEARS MAIN TORNADO AND STRONG WIND THREAT WOULD
BE SOUTH OF THE FCST AREA. ALSO...NUMEROUS SHRA/TSRA EXPECTED TO
BE SPREADING INTO/ACROSS THE AREA SUN AFTERNOON/ EVENING...ALL
COMPETING FOR THE SAME CAPE/SHEAR...WILL REDUCE THE SEVERE THREAT
FROM ANY ONE TSRA. CONCERNS AS WELL ON SUN WITH HIGH TEMPS BEING
TOO WARM AND CAPE ON THE HIGH SIDE GIVEN THICKENING
CLOUDS/SHRA/TSRA SPREADING NORTH INTO THE AREA DURING THE
AFTERNOON.
THE 3500 METER WARM CLOUD DEPTH...A WARM FRONT TO THE SOUTH FOR
LIFTING...PW VALUES NEAR 200 PERCENT OF NORMAL AND A FEED OF THIS
MOISTURE ON A 40-50KT 850MB JET SUN NIGHT ALL POINT TSRA BEING
EFFICIENT RAIN MAKERS AND A HEAVY RAIN THREAT. CONSIDERED A FLOOD
WATCH FOR SUN NIGHT/MON...BUT IT WOULD HAVE AND TO BE RATHER BROAD
WITH QPF DETAIL DIFFERENCES AMONG THE MODELS. WILL ISSUE AND ESF FOR
NOW AND PASS ALONG CONCERNS TO THE MIDNIGHT CREW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 PM CDT SAT MAY 10 2014
MAIN FORECAST CONCERNS MON THRU TUE NIGHT...SHRA/TSRA CHANCES/RAIN
AMOUNTS MON INTO MON NIGHT...COOLING TEMPERATURES.
MODEL RUNS OF 10.12Z OFFERING A TIGHTER CONSENSUS MON/MON NIGHT AS
THE MID LEVEL TROUGH LIFTS INTO THE UPPER MIDWEST AND THE SFC LOW
LIFTS TO LK SUPERIOR. TREND IS TOWARD COMPROMISE OF THE EARLIER RUNS
ON STRENGTH/TIMING OF THE MID LEVEL TROUGH INTO THE REGION WITH
SOMEWHAT BETTER RUN-TO-RUN CONSISTENCY BY THE ECMWF. IMPROVING
CONSENSUS TUE/TUE NIGHT AS THE TROUGH VIRTUALLY STALLS OVER THE
CENTRAL CONUS. FCST CONFIDENCE IN THE MON-TUE NIGHT PERIOD IS
AVERAGE TO GOOD THIS CYCLE.
BROAD/DEEP FORCING/LIFT CONTINUES OVER THE AREA MON...ALONG WITH A
FEED OF THE 1.5 INCH PW VALUES ON A 30-40KT 850MB JET. STRONGEST OF
THIS IS OVER THE FCST AREA IN THE MORNING...GRADUALLY TRANSLATING
EAST MON AFTERNOON/EVENING AS THE SFC THRU 850MB COLD FRONT/TROUGH
MOVE EAST INTO/ACROSS THE AREA. PLENTY OF FORCING/LIFT REMAINS OVER
THE WEST SIDE OF THE FCST AREA MON AFTERNOON/EVENING...WITH THE 700-
500MB TROUGH AXIS STILL WEST OF THE AREA AND SHORTWAVES LIFT UP THE
EAST SIDE OF THE TROUGH THRU WESTERN MN. HEAVIEST RAIN THREAT SHIFTS
EAST OF THE AREA THRU MON AFTERNOON/EVENING...BUT SHRA/TSRA LOOK TO
CONTINUE ACROSS THE ENTIRE FCST AREA MON AFTERNOON. AFTER A POSSIBLE
1 TO 2 INCHES OF RAIN SUN NIGHT...ANOTHER 1/4 TO 3/4 INCH OF RAIN
POSSIBLE MONDAY. SHRA/TSRA THEN TAPER OFF AND EXIT EAST THRU MON
NIGHT/TUE MORNING AS THE SFC-850MB TROUGH/FRONT MOVE EAST OF THE
AREA.
CONCERNS WITH THE SEVERE THREAT DEPICTED IN DAY 3 SIMILAR TO THOSE
CENTERED ON SUN EVENING. SHRA/TSRA SHOULD BE ONGOING ACROSS MUCH OF
THE UPPER MIDWEST MON MORNING...AND CONTINUE MUCH OF THE DAY. DEBRIS
CLOUDS AND THE RAIN SHOULD LIMIT HIGH TEMPS AND POTENTIAL FOR CAPE
TO BUILD ACROSS THE AREA. USED THE MODEL/ENSEMBLE CONSENSUS HIGHS
FOR MON BUT IF CLOUDS/SHRA/TSRA PREVAIL...THESE ARE LIKELY TOO WARM
RESULTING IN TOO MUCH CAPE IN THE PROGS. MON CAPE PROFILES ALSO DEEP
AND SKINNY SIMILAR TO SUN EVENING. NUMEROUS SHRA/TSRA ALL COMPETING
FOR THE SAME CAPE/SHEAR WILL AGAIN LIMIT THE SEVERE POTENTIAL WITH
ANY ONE STORM.
DRIER/COOLER 925-700MB AIR WRAPS ACROSS THE AREA FOR TUE AFTERNOON/
NIGHT FOR WHAT SHOULD BE DRY PERIODS AND A DECREASE OF CLOUDS. 850MB
TEMPS IN THE +2C TO -1C RANGE BY 12Z WED. THIS PLUS LIGHT WINDS AND
MOSTLY CLEAR SKIES TUE NIGHT...LOWS IN THE UPPER 30S-LOW 40S WED
MORNING APPEAR REASONABLE.
FOR WEDNESDAY THRU SATURDAY.../DAYS 4 TO 7/...
MAIN FORECAST CONCERNS THIS PERIOD...COOL TEMPERATURES AND -SHRA
CHANCES THRU THE PERIOD.
MEDIUM RANGE MODEL RUNS OF 10.00Z/10.12Z HAVE COME INTO BETTER
AGREEMENT WED/THU ON LOCATION/STRENGTH OF THE TROUGHING TO SLOWLY
MOVE ACROSS CENTRAL NOAM. MODELS CONVERGING TOWARD THE EARLIER
ECMWF RUNS. IMPROVING CONSENSUS FOR SOME NORTHERN STREAM ENERGY TO
DROP INTO THE UPPER MIDWEST THU/FRI...FURTHER DEEPENING THE TROUGH
AND CARVING OUT A MID LEVEL OVER THE WESTERN GREAT LAKES FOR FRI
INTO SAT. GIVEN THE IMPROVED MEDIUM RANGE MODEL CONSENSUS...DAY
4-7 FCST CONFIDENCE IS GENERALLY GOOD THIS CYCLE...ESPECIALLY FOR
BELOW NORMAL TEMPERATURES.
ONE SURGE OF COLDER LOW LEVEL HAS ALREADY SETTLED OVER THE REGION BY
WED. A SECONDARY...EVEN COLDER SURGE IS POISED TO DROP SOUTH INTO
THE REGION FOR THU/FRI. 850MB TEMPS PROGGED TO BOTTOM OUT IN THE
-1C TO -3C RANGE AT 12Z FRI. SOME TEMP RECOVERY SAT AS WARMER AIR
ACTUALLY WRAPS IN FROM THE NORTH. SIGNAL REMAINS CONSISTENT FOR
850MB TEMPS TO BE SOME 1.5 TO 2 STANDARD DEVIATIONS BELOW NORMAL
ACROSS THE UPPER MIDWEST FOR MOST OF THE WE-SAT PERIOD. CONFIDENCE
IS GOOD FOR DAY 4-7 HIGHS TO BE SOME 10-15F BELOW NORMAL. LOWS
THRU THE PERIOD A LITTLE TRICKER AND DEPENDENT ON EXTENT OF CLOUD
COVER ANY ONE NIGHT. WITH MODEST 925-700MB MOISTURE AND THE DEEP
COLD CORE TROUGH/LOW AND CYCLONIC FLOW OVER THE REGION...CLOUDS
EXPECTED TO PREVAIL MUCH OF THE WED-SAT PERIOD. IF ANY ONE OF THE
NIGHTS ENDS UP MORE CLEAR THAN CLOUDY...PATCHY FROST WOULD BE
EXPECTED...ESPECIALLY ALONG/NORTHEAST OF I-94 THU/FRI NIGHTS. FOR
NOW THE MODEL/ENSEMBLE CONSENSUS HIGHS/LOWS FOR WED- SAT ARE WELL
TRENDED.
LESS CONFIDENCE ON -SHRA CHANCES IN THE WED-SAT PERIOD AS THESE
CHANCES WILL DEPEND ON THE TIMING OF STRONGER SHORTWAVES THRU THE
PERSISTENT TROUGHING OVER THE REGION. PRESENT TIMING HAS ONE
STRONGER SHORTWAVE DROPPING INTO THE REGION WED THEN MORE
SHORTWAVE ENERGY ROTATING AROUND THE DEEP TROUGH/MID LEVEL LOW
OVER THE WESTERN GREAT LAKES FRI/SAT. WITH THE DEEP CYCLONIC
FLOW...COLD CORE OF 850-700MB TEMPS OVER THE REGION...STEEP SFC-
700MB LAPSE...RATES/WEAK INSTABILITY DURING THE AFTERNOON
HOURS...ANY SHORTWAVE WOULD BE CAPABLE OF TRIGGERING SCT -SHRA.
SMALL -SHRA CHANCES MUCH OF THE WED-SAT PERIOD STILL LOOK
REASONABLE UNTIL THE SHORTWAVE TIMING DETAILS CAN BE SORTED OUT.
ANY PRECIP DURING THE WED-SAT WOULD BE SCT AND LIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1149 PM CDT SAT MAY 10 2014
SOME SCATTERED RAIN SHOWERS HAVE DEVELOPED ACROSS SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN AND WILL TRACK QUICKLY TO THE EAST
OVERNIGHT. CONDITIONS ARE MAINLY VFR THOUGH A FEW SPOTS HAVE
BRIEFLY DROPPED TO MVFR WITH VISIBILITY GOING DOWN TO 5SM. BASED
ON THE LOW CHANCES THAT ONE OF THESE SHOWERS WOULD DIRECTLY HIT
RST/LSE...HAVE JUST LEFT IT AS VCSH AND VFR.
THE MAIN FOCUS THEN GOES TO TOMORROW EVENING WHEN IT APPEARS
LIKELY THAT WIDESPREAD THUNDERSTORMS WILL DEVELOP ACROSS THE
REGION AS A WARM FRONT LIFTS NORTH INTO THE REGION. THERE IS SOME
QUESTION ABOUT THE EXACT START UP TIME OF THE CONVECTION...BUT IT
APPEARS MOST LIKELY TO OCCUR AROUND 2Z AT RST AND 4Z AT LSE.
VISIBILITY SHOULD DROP TO IFR OR LOWER IF THE STORMS TRAIN OVER
THE SAME LOCATIONS TOMORROW EVENING. BASED ON THE HIGH CONFIDENCE
THAT WE WILL HAVE RAINS/STORMS...HAVE PUT A PREVAILING TSRA GROUP
IN THE TAFS FOR TOMORROW EVENING.
&&
.HYDROLOGY...
ISSUED AT 310 PM CDT SAT MAY 10 2014
MINOR FLOODING/HIGH WATER CONTINUES ALONG PORTIONS OF THE
MISSISSIPPI RIVER. LATER SUN AFTERNOON INTO MON EVENING WILL BE A
WET PERIOD...WITH POTENTIAL FOR 1 TO 2 OR MORE INCHES OF RAINFALL
DURING THAT PERIOD. THE HEAVIEST RAIN/HIGHEST TOTALS WILL FALL
SUNDAY NIGHT INTO MONDAY MORNING. THESE RAINS COULD HAVE
ADDITIONAL IMPACTS ON BOTH TRIBUTARIES AND THE MISSISSIPPI
RIVER...SLOWING THE RATES OF FALL...PRODUCE ADDITIONAL RISES OR
RENEWED FLOODING. WILL ISSUE AN ESF CONCERNING THE POTENTIAL
HEAVY RAINS SUN NIGHT/MON AND RISING RIVER LEVELS/FLOODING THREAT.
CHECK THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...HALBACH
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1128 PM MDT MON MAY 12 2014
.UPDATE...
ISSUED AT 704 PM MDT MON MAY 12 2014
MINOR UPDATE TO BRING IN CURRENT OBS AND RAISE POPS IN THE SAN
LUIS VALLEY AND SOUTHERN SANGRES. -PJC
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM MDT MON MAY 12 2014
...HEAVY SNOW CONTINUES FOR THE CONTINENTAL DIVIDE...WITH FREEZING
TEMPERATURES FOR THE SOUTHEAST PLAINS TONIGHT...
ENERGY DROPPING DOWN THE WEST SIDE OF THE UPPER TROF WILL KEEP SNOW
SHOWERS GOING ACROSS SOUTHERN AND WESTERN PORTIONS OF THE AREA.
LAPSE RATES ARE STEEP BENEATH THE UPPER TROF ALOFT..AND SNOW HAS
BEEN REALLY COMING DOWN IN WEB CAMS AT WOLF CREEK. VIS IS DOWN TO
1/4 MILE AS OF THIS LAST HOUR. ROADWAYS STILL LOOK CLEAR...BUT WITH
TEMPERATURES ALREADY IN THE 20S ACROSS THE HIGHER ELEVATIONS...IT
WOULD NOT TAKE MUCH MORE COOLING FOR SNOW TO BEGIN TO STICK.
NAM12...GFS...AND RAP ALL KEEP HEAVY SNOW CONTINUING THROUGH THE
OVERNIGHT HOURS...THOUGH MAJORITY WILL LIKELY FALL BEFORE MIDNIGHT.
FOR THAT REASON...UPGRADED THE WINTER WEATHER ADVISORIES FOR THE
HIGHER ELEVATIONS OF THE EASTERN SAN JUANS AND LA GARITAS TO A
WINTER STORM WARNING WITH AN EARLIER FORECAST PACKAGE UPDATE.
EASTERLY UPSLOPE FLOW INTO THE EASTERN SLOPES OF THESE RANGES WILL
ALSO LEAD TO FAIRLY HEALTHY SNOW AMOUNTS FOR THE WESTERN SIDE OF THE
SAN LUIS VALLEY. CDOT WEBCAM AT ANTONITO HAS SOME SNOW
FALLING...THOUGH MOST IS MELTING ON PAVEMENT SURFACES...AND WITH
TEMPERATURES STILL AROUND OR SLIGHTLY ABOVE FREEZING EXPECT THIS TO
CONTINUE. HAVE PUT UP A WINTER WEATHER ADVISORY FOR THE LOWER
ELEVATIONS OF THE EASTERN SAN JUANS AND LA GARITAS AS WELL AS THE
HIGHER AREAS OF THE SAWATCH RANGE. WARNING AREAS COULD PICK UP A
TOTAL OF 8 TO 16 INCHES...WITH 4 TO 8 INCHES FOR THE ADVISORY AREAS.
THE WESTERN SIDE OF THE SAN LUIS VALLEY COULD SEE ON THE ORDER OF
1 TO 4 INCHES...BUT WARM GROUND MAY LIMIT ACCUMULATIONS TO LESSER
AMOUNTS.
THE SANGRES AND WETS COULD ALSO PICK UP SOME ADDITIONAL
ACCUMULATIONS TONIGHT...WITH ANOTHER 1 TO 3 INCHES FOR THE LOWER
ELEVATIONS...AND 2 TO 5 INCHES FOR THE HIGHER PEAKS.
SNOW WILL WIND DOWN EARLY TOMORROW MORNING...SO HEADLINES WILL
EXPIRE AT 6 AM. MEANWHILE...SOUTHEAST PLAINS WILL SEE A WIDESPREAD
FREEZE TONIGHT...AND CURRENT FREEZE WARNING STILL LOOKS ON TRACK.
UPPER TROF AXIS WILL SHIFT EAST OF THE AREA ON TUESDAY...BUT WITH
LINGER MOISTURE AND INSTABILITY...EXPECT ANOTHER ROUND OF ISOLATED
TO SCATTERED SHOWERS ACROSS THE MOUNTAINS. TEMPERATURES WILL
REBOUND A FEW DEGREES OVER THOSE OF TODAY...BUT HIGHER MOUNTAINS
WILL STILL SEE PRECIPITATION IN THE FORM OF SNOW. ANY ACCUMULATIONS
SHOULD REMAIN LIGHT...WITH A SPOTTY 1-3 INCHES POSSIBLE. -KT
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 340 PM MDT MON MAY 12 2014
TUESDAY NIGHT THROUGH SATURDAY...LONG RANGE MODELS INDICATE THAT THE
UPPER SYSTEM WILL PARK OVER THE MIDWEST THROUGH MUCH OF THE WORK
WEEK...KEEPING COLORADO UNDER NW FLOW ALOFT. THIS FLOW IS A COOLER
ONE...SO THE WARM UP FOR THE FORECAST AREA IS EXPECTED TO BE SLOWER
UNTIL THE UPPER PATTERN SHIFTS. THE UPPER RIDGE TO THE WEST IS
FORECAST TO FINALLY FLATTEN AND SLIDE ACROSS THE STATE ON SAT. THIS
TRANSLATES TO ANOTHER THREAT OF FREEZING TEMPS FOR THE PLAINS TUE
NIGHT...THEN HIGH TEMPS ON WED IN THE 50S AND 60S. TEMPS GRADUALLY
WARM THU THROUGH SAT WITH MAX TEMPS IN THE 70S FOR THE PLAINS...AND
IN THE 60S FOR THE HIGH VALLEYS. EXTENDED MODELS ALSO HINT AT MORE
OF A SUMMERTIME PATTERN WHEN IT COMES TO CONVECTION...WITH AN
ISOLATED THREAT FOR SHOWERS AND STORMS OVER THE MTS EACH AFTN AND
EARLY EVE THROUGH SAT.
SUNDAY AND MONDAY...A LARGE UPPER TROUGH OF LOW PRESSURE MOVES
ONSHORE ACROSS THE WEST COAST LATE SAT...PRODUCING INCREASING SW
FLOW ALOFT FOR THE DESERT SW. LOOK FOR DRY AND VERY WARM CONDITIONS
FOR THE FORECAST AREA BOTH SUN AND MON...WITH MAX TEMPS IN THE 80S
FOR THE E PLAINS...AND IN THE 60S AND 70S FOR THE HIGH VALLEYS.
MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1114 PM MDT MON MAY 12 2014
KALS WILL BE IN AND OUT OF IFR AND MVFR CONDITIONS THROUGH AT
LEAST 12Z TUESDAY DUE TO LIGHT SNOW SHOWERS AND LOW CEILINGS.SNOW
ACCUMULATIONS WILL LIKELY BE AN INCH OR LESS. GUSTY EAST WINDS
CAN ALSO BE EXPECTED TO CONTINUE UNTIL ABOUT 09Z TUESDAY. VFR
CONDITIONS ARE EXPECTED TO RETURN BY 15Z TUESDAY.
EXPECTING VFR CONDITIONS AT KCOS AND KPUB THROUGH TUESDAY NIGHT.
WIND GUSTS UP TO 25KTS FROM THE NORTH ARE POSSIBLE AT BOTH AIR
FIELDS LATE TUESDAY MORNING. -PJC
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING UNTIL 8 AM MDT TUESDAY FOR COZ083>089-093>099.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT TUESDAY FOR COZ060-064-
067.
WINTER STORM WARNING UNTIL 6 AM MDT TUESDAY FOR COZ066-068.
&&
$$
UPDATE...PJC
SHORT TERM...KT
LONG TERM...MOORE
AVIATION...PJC
AREA FORECAST DISCUSSION
NWS ALBANY NY
128 AM EDT TUE MAY 13 2014
.SYNOPSIS...
A COLD FRONT DROPPING SOUTH FROM CANADA WILL MOVE THROUGH THE REGION
TONIGHT...THEN STALL ACROSS THE MID ATLANTIC STATES TUESDAY. HIGH
PRESSURE OVER THE CANADIAN MARITIMES WILL KEEP A SOUTHEAST FLOW OF
AIR ACROSS THE REGION DURING THE MIDDLE OF THE WEEK ALONG WITH A
CHANCE OF SHOWERS. MORE WIDESPREAD RAINFALL IS LIKELY LATE IN THE
WEEK AS A STRONGER FRONT OVER THE GREAT LAKES WILL PUSH TOWARD
THE EASTERN SEABOARD.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 100 AM EDT...A FEW LIGHT RAIN SHOWERS HAVE TRACKED INTO THE
ADIRONDACK REGION AND CONTINUE TO TRACK EAST-SOUTHEAST THIS EARLY
TUESDAY MORNING. BACKDOOR COLD FRONT HAS BECOME QUASI-STATIONARY
ACROSS THE SCHOHARIE VALLEY...MID MOHAWK VALLEY AND DACKS PER MESO
OBS AND RADAR VELOCITY INTERPRETATIONS. THIS WILL KEEP MOSTLY
CLOUDY SKIES AND A LIGHT NORTHEAST WIND ACROSS MOST OF THE REGION.
SOME ADDITIONAL LIGHT RAIN SHOWERS ARE SEEN FURTHER UPSTREAM AS
PER THE LATEST HRRR REFLECTIVITY FORECASTS...SOME OF THESE SHOWERS
MAY IMPACT THE REGION TOWARD SUNRISE. OTHERWISE...PER OBS...DID
RAISE OVERNIGHT LOWS A COUPLE OF DEGREES.
A SOMEWHAT BETTER CHANCE FOR SHOWERS EXPECTED ON TUESDAY...
ESPECIALLY WEST OF THE HUDSON RIVER VALLEY AS A WEAK DISTURBANCE
APPROACHES. HOWEVER COVERAGE IS STILL ONLY EXPECTED TO BE
SCATTERED AT THIS TIME.
ON TUESDAY THE 500HPA RIDGE AXIS SHIFTS FM GRTLKS TO E SEABOARD.
AT THE SAME TIME THE RIDGE BCMS MUCH SHARPER. THE BACK DOOR COLD
FRONT DRIFTS A BIT FURTHER S AS ITS PARALLELS THE 500HPA FLOW
TUES...BUT AS THE 500HPA RIDGE MVS EAST THE FRONT BRIEFLY STALLS
AND BEGINS TO RETURN N LATE TUESDAY. AS THE 500HPA RIDGE SHIFTS E
TUE THREAT OF -SHRA/SCT TSTMS WILL BE INCRG ASSOC WITH THESE
PASSING FEATURES. THE MDLS HV COME INTO BETTER AGREEMENT WITH TDYS
12UTC RUNS.
THE IMPACTS OF THE CDFNT WILL BE MODEST AS IT WILL REMAIN
SHALLOW...WITH WINDS SHIFTING TO NE TO E TO SE TNGT. IT WILL PUT
FCA IN MARINE LAYER LATER TNGT AND TUES WITH CONSIDERABLE
CLOUDS...BUT MAX TEMPS TUES WILL STILL MAKE 70 IN MOST AREAS TUES.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
WITH THE FRONTAL BOUNDARY STALLED TO OUR SOUTH AND HIGH PRESSURE
OVER THE CANADIAN MARITIMES. THIS PERIOD WILL FEATURE A SOUTHEAST
FLOW OF MARITIME INFLUENCED AIR WITH LOTS OF CLOUDS AND A CHANCE OF
SHOWERS. BY WEDNESDAY AND WEDNESDAY NIGHT THE FLOW WILL TEND TO
BECOME MORE SOUTHERLY AND THE CHANCE FOR A THUNDERSTORM WILL
INCREASE...ESPECIALLY ACROSS WESTERN AREAS. POPS OF 20 TO 50 PERCENT
HAVE BEEN FORECAST DURING THIS PERIOD...WITH THE HIGHEST POPS ACROSS
THE WESTERN ZONES.
LOWS TUESDAY NIGHT WILL BE IN THE UPPER 40S TO MID 50S. HIGHS
WEDNESDAY GENERALLY IN THE LOW OR MID 70S ACROSS NY ZONES...AND THE
MID OR UPPER 60S ACROSS THE NEW ENGLAND ZONES. LOWS WEDNESDAY IN THE
MID 50S TO LOWER 60S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE PERIOD STARTS OUT ON THURSDAY WITH OUR REGION FIRMLY ENTRENCHED
IN A WARM SECTOR ASSOCIATED WITH A MERIDIONAL FLOW PATTERN AND
SOUTHERLY FLOW. A DEEP TROUGH IS FORECAST TO DEVELOP ACROSS THE
MIDWEST AND MISSISSIPPI VALLEY REGION...WITH AN UPPER RIDGE HOLDING
FIRM ALONG THE EASTERN SEABOARD. SO WE ARE EXPECTING WARM
TEMPERATURES WITH INCREASING HUMIDITY LEVELS. NOT MUCH IN THE WAY OF
FORCING SEEN IN THE 12Z GUIDANCE EXCEPT FOR A QUASI-STATIONARY
SURFACE FRONT NEAR WEST-CENTRAL NY. SO BEST CHANCE FOR CONVECTION
WILL BE WEST OF THE HUDSON RIVER VALLEY. WILL MENTION CHANCE OF
THUNDER DUE TO INCREASING DEWPOINTS AND MODEST SURFACE-BASED
INSTABILITY.
THURSDAY NIGHT...THE UPPER LEVEL PATTERN IS FORECAST TO BECOME MORE
AMPLIFIED...SO THE FRONTAL BOUNDARY OVER WESTERN/CENTRAL NY MAY NOT
MAKE MUCH PROGRESS EASTWARD AS WAVE DEVELOPS ALONG IT. AS OF
NOW...FRIDAY LOOKS TO BE THE MOST ACTIVE DAY ACROSS THE REGION IN
TERMS OF POTENTIAL HEAVY RAINFALL. WITH THE AMPLIFIED
PATTERN...THERE WILL BE A SURGE OF HIGH PWATS NORTHWARD INTO THE
REGION WITH 12Z GEFS INDICATING +2 TO +3 STDEV...COURTESY OF A +3 TO
+4 STDEV SOUTHERLY WIND COMPONENT AT 850 MB. ALONG WITH THE
MOISTURE-RICH AIR...THERE COULD BE SOME EMBEDDED CONVECTION WHICH
MAY LOCALLY ENHANCE RAINFALL RATES TOO.
THE FRONTAL BOUNDARY WITH FORECAST MULTIPLE WEAK WAVES OF LOW
PRESSURE ALONG IT...WILL LIFT NORTHEASTWARD ACROSS THE AREA FRIDAY
INTO FRIDAY NIGHT. THERE ARE TIMING DIFFERENCES IN MODEL SOLUTIONS
FOR WHEN THE HEAVIEST RAIN WOULD OCCUR...BUT THERE IS ENOUGH
CONFIDENCE FOR LIKELY POPS ACROSS THE ENTIRE AREA FRIDAY AND FRIDAY
NIGHT WITH HEAVY RAINFALL THREAT.
ON SATURDAY...DRYING FROM THE SOUTH AND WEST SHOULD OCCUR. AS A
SPRAWLING UPPER TROUGH STARTS TO GET CARVED OUT ACROSS THE EASTERN
CONUS. A FEW WEAK DISTURBANCES ROTATING AROUND THE MAIN UPPER LOW
POSITIONED NORTH OF THE GREAT LAKES MAY RESULT IN ISOLATED TO
SCATTERED SHOWERS DURING THE WEEKEND AND INTO EARLY NEXT WEEK. WITH
A CHANGE IN AIR MASS...TEMPERATURES ARE EXPECTED TO COOL DOWN TO
NEAR OR SLIGHTLY BELOW NORMAL READINGS UNDER THE INFLUENCE OF THE
TROUGH.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A BACKDOOR FRONTAL BOUNDARY IS MOVING SOUTH ACROSS THE REGION AND
WILL STALL JUST SOUTH AND WEST OF THE REGION FOR DURING THE DAY
TUESDAY. THIS FRONT WILL BE A FOCUS FOR SHOWERS AND
THUNDERSTORMS...BUT IT SHOULD REMAIN FAR ENOUGH AWAY FROM OUR REGION
TO KEEP MOST OF THE ACTIVITY AWAY FROM OUR AREA. STILL...AN ISOLATED
RAIN SHOWER CANNOT BE RULED OUT. FOR NOW...WE HAVE GONE WITH JUST A
VCSH FOR RAIN SHOWERS FOR DURING THE DAY TUESDAY AND INTO TUESDAY
EVENING FOR ALL TAF SITES...BUT IT LOOKS TO REMAIN DRY MOST OF THE
TIME.
OTHERWISE...MID LEVEL CLOUDS OVERNIGHT WILL LOWER TO ABOUT 4-6 KFT
DURING THE DAY TUESDAY...AS THE E-SE FLOW OFF THE ATLANTIC BRING
MOISTURE INTO THE REGION. FLYING CONDITIONS SHOULD REMAIN VFR
THROUGH THE ENTIRE TAF PERIOD...ALTHOUGH CIGS WILL BECOME BKN-OVC
FOR ALL TAF SITES.
NORTHERLY WINDS OF 5-10 KTS OVERNIGHT WILL BECOME E-SE FOR TUESDAY
INTO TUESDAY EVENING AT 5-10 KTS.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
FRIDAY: HIGH OPERATIONAL IMPACT. LIKELY RA...TSRA.
FRIDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
THE RH VALUES WILL RECOVER TONIGHT TO BETWEEN 75 AND 100 PERCENT
TONIGHT. ON TUESDAY THE RH VALUES WILL LOWER TO BETWEEN 40 AND 55
PERCENT. THERE WILL ALSO BE A CHANCE OF SHOWERS ON TUESDAY.
SURFACE WINDS WILL BE UNDER 10 MPH TONIGHT. ON TUESDAY SURFACE WINDS
WILL BE SOUTHEAST AT 5 TO 15 MPH WITH GUSTS OF 20 TO 25 MPH.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC ISSUES ARE EXPECTED OVER THE NEXT SEVERAL
DAYS.
A COLD FRONT DROPPING SOUTH FROM CANADA WILL MOVE THROUGH THE REGION
TONIGHT...THEN STALL ACROSS THE MID ATLANTIC STATES TUESDAY. HIGH
PRESSURE OVER THE CANADIAN MARITIMES WILL KEEP A SOUTHEAST FLOW OF
AIR ACROSS THE REGION DURING THE MIDDLE OF THE WEEK ALONG WITH A
CHANCE OF SHOWERS. MORE WIDESPREAD RAINFALL IS LIKELY LATE IN THE
WEEK AS A STRONGER FRONTAL OVER THE GREAT LAKES WILL PUSH TOWARD THE
EASTERN SEABOARD.
ANY RAINFALL DURING THE EARLY AND MIDDLE PART OF THE WEEK WILL BE
LIGHT AND HAVE LITTLE IMPACT ON AREA STREAMS AND RIVERS. THE
RAINFALL LATER IN THE WEEK COULD BE HEAVY AND WE WILL NEED TO WATCH
NUMERICAL MODEL TRENDS CLOSELY.
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...GJM/SNYDER
NEAR TERM...BGM/SNYDER/JPV
SHORT TERM...GJM
LONG TERM...JPV
AVIATION...FRUGIS/JPV
FIRE WEATHER...GJM
HYDROLOGY...GJM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1257 AM CDT TUE MAY 13 2014
.DISCUSSION...
244 PM...MULTIPLE FORECAST CONCERNS AND CHALLENGES THROUGH THE
PERIOD INCLUDING THUNDERSTORM COVERAGE/TIMING THROUGH TUESDAY
AFTERNOON ALONG WITH SEVERE/HEAVY RAIN POTENTIAL. THEN TURNING
MUCH COLDER MIDWEEK WITH A PERIOD OF SHOWERS/RAIN FROM WEDNESDAY
EVENING INTO THURSDAY.
CONVECTIVE TRENDS OVER THE NEXT FEW HOURS DISCUSSED IN THE
ABOVE/RECENT MESOSCALE DISCUSSION WITH ATTENTION NOW SHIFTING TO
THUNDERSTORMS EXTENDING FROM CENTRAL IOWA SOUTH TO TEXAS...AHEAD
OF THE SLOWLY ADVANCING COLD FRONT. SHORT TERM GUIDANCE CONTINUES TO
SHOW ADDITIONAL ACTIVITY DEVELOPING AHEAD OF THE CURRENT LINE AS IT
ALL SLOWLY SHIFTS EAST...WHICH WOULD BRING ACTIVITY INTO THE WESTERN
CWA AS SOON AS 23Z-00Z. SEVERE POTENTIAL WOULD BE HIGHEST EARLIER
WITH BETTER INSTABILITY BEFORE LOST OF DAYTIME HEATING...THOUGH
TEMPS WILL ONLY SLOWLY DROP THROUGH THE 70S THIS EVENING. AS NOTED
IN THE PREVIOUS DISCUSSION...DO ANTICIPATE ANOTHER WATCH LATER THIS
EVENING BUT HOW FAR EAST AND COVERAGE OF SEVERE POTENTIAL WILL BE
TIED TO TIMING. MAIN THREATS WOULD CONTINUE TO BE LARGE HAIL AND
DAMAGING WIND GUSTS.
PRECIPITABLE WATER VALUES INCREASE TO 1.5 INCHES AND EVEN A BIT
HIGHER TONIGHT AND COMBINED WITH DEWPOINTS IN THE UPPER 60S AND
EVEN A FEW LOWER 70S...HEAVY RAIN IS LIKELY. WHILE THE INDIVIDUAL
STORMS WILL BE MOVING NORTHEAST FAIRLY QUICKLY...THE ENTIRE FRONTAL
PROGRESSION EASTWARD WILL BE RELATIVELY SLOW THUS HEAVY RAIN OVER
THE SAME AREAS COULD RESULT IN SOME FLOODING POTENTIAL. AND WITH THE
HEAVY RAINS IN PARTS OF THE AREA SUNDAY EVENING...INCLUDING THE
SOUTHERN SUBURBS AND NORTHWEST INDIANA...ADDITIONAL HEAVY RAIN COULD
LEAD TO LOCALIZED FLASH FLOODING. HOWEVER...CONFIDENCE IS SOMEWHAT
LOW WITH THE POTENTIAL FOR CONVECTION TO THE SOUTHWEST TO MOVE EAST
SOUTH OF THE AREA AND POTENTIALLY CUT OFF STRONGER/HEAVIER PRECIP
ACROSS NORTHERN IL.
PRECIP PROGRESSION EASTWARD WILL LIKELY SLOW TUESDAY MORNING AS IT
SLOWLY ENDS FROM WEST TO EAST BUT COULD CONTINUE INTO THE AFTERNOON
ACROSS NORTHWEST INDIANA. TEMP TRENDS WILL ALSO BE TRICKY AS THEY
WILL LIKELY FALL OR BECOME STEADY ACROSS THE EASTERN HALF WITH
SOME RECOVERY IN THE WEST IN THE AFTERNOON. TEMPS WILL CONTINUE TO
FALL INTO THE MID/UPPER 40S FOR LOWS BY WEDNESDAY MORNING AND
WHILE THESE ARE CLOSE TO NORMAL FOR MID MAY...IT WILL LIKELY FEEL
MUCH COLDER GIVEN THE CURRENT TEMPS AND DEWPOINTS.
AS THE UPPER TROUGH DIGS ACROSS THE CENTRAL AND SOUTHERN PLAINS
WEDNESDAY INTO WEDNESDAY NIGHT...NEW LOW PRESSURE WILL DEVELOP OVER
THE OHIO VALLEY AND LIFT NORTHEAST ACROSS THE CENTRAL OR EASTERN
GREAT LAKES REGION ON THURSDAY. WHILE CONFIDENCE IS INCREASING IN
THE OVERALL TRENDS WITH THIS SYSTEM...ITS EXACT TRACK COULD STILL
HAVE LARGE IMPACTS ON THE SPECIFICS OF THE FORECAST. FIRST...THERE
WILL PROBABLY BE A SHARP PRECIP GRADIENT ON THE NORTHWEST SIDE OF
THIS SYSTEM...WHICH WILL LIKELY BE ACROSS THE WESTERN CWA. THE
CLOSER THE LOW TRACKS TO THE AREA...THE STRONGER THE NORTHERLY WINDS
WILL BE...ESPECIALLY ACROSS THE EASTERN CWA. BUT AS CLOUDS AND
SHOWERS SPREAD NORTH WEDNESDAY WITH A RATHER COLD/WET WEDNESDAY
NIGHT/THURSDAY MORNING. HIGHS WEDNESDAY AND THURSDAY LIKELY ONLY
IN THE 50S...THOUGH ANY SUNSHINE ESPECIALLY WESTERN AREAS COULD
PUSH TEMPS INTO THE 60S.
AS AN UPPER LOW DEVELOPS ACROSS THE NORTHERN LAKES REGION THURSDAY
AND SLOWLY DRIFTS EAST THIS WEEKEND...WEAK IMPULSES COULD HELP
TRIGGER AFTERNOON SHOWERS ON FRIDAY AND PERHAPS AGAIN ON SATURDAY
THOUGH COVERAGE SHOULD BE MAINLY ISOLATED. TEMPERATURES WILL START
A SLOW WARMING TREND THROUGH THE 60S THIS WEEKEND AND PERHAPS
BACK INTO THE 70S EARLY NEXT WEEK. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LIGHT AND VARIABLE WINDS TRENDING SOUTHEAST NEXT FEW
HOURS...THEN SOUTH LATE TONIGHT.
* WIND SHIFT TO WEST LATER THIS MORNING.
* MVFR AND POSSIBLE IFR CIGS ARRIVE OVERNIGHT...THEN GRADUALLY
LIFT LATER THIS AFTERNOON.
MDB
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE OVER NORTHERN WISCONSIN WILL CONTINUE TO MOVE
NORTHEASTWARD TONIGHT WHILE AN ASSOCIATED COLD FRONT NOW CROSSING
THE MISSISSIPPI RIVER CONTINUES EASTWARD. THUNDERSTORMS HAVE
CLEARED TO THE EAST OF THE TERMINALS THOUGH GYY MAY SEE A FEW
SKIRT TO THE EAST IN THE NEXT HOUR OR TWO. OTHERWISE SOME LIGHT
SHOWERS MAY MOVE ACROSS IN THE NEXT FEW HOURS. WINDS IN THE WAKE
OF THE STORMS HAVE BECOME ERRATIC...THOUGH SPEEDS HAVE DROPPED
OFF. EXPECT THAT THERE WILL BE A TREND TO SOUTH TO SOUTHWEST WINDS
AHEAD OF THE FRONT THROUGH THE OVERNIGHT. THE FRONT WILL CROSS THE
TERMINALS AFTER DAYBREAK WITH A SHIFT TO WEST OR WEST-NORTHWEST
WINDS. VFR CIGS ARE IN PLACE CURRENTLY BUT MVFR AND SOME IFR IS
OFF TO THE WEST AND EXPECT THAT THIS WILL MOVE IN LATER TONIGHT.
HAVE SLOWED THE TIMING BY A FEW HOURS AND ADDITIONAL TIMING TWEAKS
MAY BE NEEDED. MVFR LOOKS TO CONTINUE THROUGH MUCH OF THE
AFTERNOON...THOUGH BASES SHOULD LIFT WITH TIME...AND MAY SCATTER
DURING THE EVENING.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW CONFIDENCE IN WIND SPECIFICS NEXT FEW HOURS BUT MEDIUM
CONFIDENCE IN OVERALL TREND.
* MEDIUM-HIGH CONFIDENCE IN WIND DETAILS AFTER 12Z OR SO.
* HIGH CONFIDENCE IN MVFR CIGS ARRIVING WITH MEDIUM CONFIDENCE IN
TIMING. LOW CONFIDENCE IN IFR POTENTIAL. MEDIUM CONFIDENCE IN
BASES RISING THROUGH THE AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...RAIN LIKELY. MVFR CIGS/VIS POSSIBLE.
THURSDAY...CHANCE OF SHRA.
FRIDAY...CHANCE OF SHRA.
SATURDAY...VFR. WX NIL.
SUNDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
320 PM CDT
AREAS OF DENSE FOG CONTINUE TO PERSIST LATE THIS AFTERNOON ACROSS
NORTHERN LAKE MICHIGAN PER SHIP OBS AND SURROUNDING SFC COASTAL
OBS NORTH OF THE WARM FRONT DRAPED WEST TO EAST ACROSS THE MIDDLE
PART OF THE LAKE. THIS WARM FRONT EXTENDS BACK WEST TO LOW
PRESSURE OVER E CENTRAL MN / NORTHWEST WI WHICH WILL CONTINUE TO
MOVE NORTHEAST TONIGHT. THIS FRONTAL BOUNDARY WILL CONTINUE TO BE
A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT TONIGHT AS WELL. A
COLD FRONT ASSOCIATED WITH THE LOW WILL SWEEP WEST TO EAST ACROSS
THE LAKE AROUND DAYBREAK TUESDAY SWEEPING OUT THE FOG AND
BRINGING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
MORNING TUESDAY.
WINDS OCCASIONALLY EXCEEDING SMALL CRAFT ADVISORY THRESHOLDS WILL
CONTINUE INTO THIS EVENING ALONG THE ILLINOIS AND INDIANA
SHORELINES. ONGOING CONVECTION HAS DISRUPTED THE WIND FIELD
CAUSING AN ONSHORE LAKE BREEZE ESPECIALLY FARTHER NORTH CLOSER TO
THE OUTFLOW FROM EARLIER THUNDERSTORMS ACROSS WISCONSIN AND
CENTRAL LAKE MICHIGAN. AS THE SOUTHERLY GRADIENT REESTABLISHES
ITSELF... NEW SCATTERED THUNDERSTORMS MAY ALSO CAUSE HIGHER WINDS AND
WAVES INTO THE EVENING THROUGHOUT THE NEAR SHORE WATERS.
ED F
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 3 AM TUESDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1130 PM CDT Mon May 12 2014
.DISCUSSION...
ISSUED 850 PM CDT Mon May 12 2014
Updating forecast tonight to address convection chances as band of
showers and thunderstorms moving ne toward the IL river at mid
evening, spreads into eastern IL overnight and Tue morning as it
weakens. Isolated strong to severe storms possible next hour or
two nw of the IL river but main severe wx threat has shifted into
far northern IL near the WI border near warm front. SPC has
trimmed slight risk of severe storms this evening to areas from
Peoria north, including Peoria, Woodford, Knox, Stark and Marshall
counties. 1005 mb low pressure along the SE MN and WI border has
a cold front extending southward through eastern IA into central
MO and nw AR. Moist and unstable airmass over IL with dewpoints of
65 to 70F with breezy south winds. Leading edge of showers and
thunderstorms was between Galesburg and Peoria to near Jacksonville
and west of St Louis metro. Cold front to track east to near I-57
by 12Z/7 am Tue. Forecast lows look on track tonight. Mild lows in
the mid to upper 60s over eastern IL ahead of cold front tonight
while cooler mid to upper 50s behind the cold front over the IL
river valley.
07
&&
.AVIATION...
ISSUED 1125 PM CDT Mon May 12 2014
Little change from previous thinking with the main forecast
problem being from coverage of rainfall overnight and affect
on cigs with several of the short term solutions showing cigs
down to IFR by morning. Storms have weakened considerably from
earlier this evening to just rain showers with an isolated
thunderstorm. Satellite and surface observations showing a rather
large area of MVFR and local IFR cigs to our west and southwest
and models are picking up on this and bringing in the lower cigs
overnight. Will continue from previous forecast trends in lowering
cigs to low MVFR and IFR at PIA and BMI around 12z. Will keep the
MVFR cigs going with period of light rain in the morning and then
push the rain to our east by late afternoon with a gradual trend
toward VFR cigs aftr 00z.
Surface winds ahead of the front will be south to southwest at 10
to 15 kts...but at DEC and CMI which have been recently affected
by a thunderstorm outflow boundary, will have a VRB direction to
start the TAF off with at DEC and CMI. Winds should recover about
an hour later and go back to the south and southwest. Once a cold
front pushes through our area Tuesday morning, winds will shift
into the west and northwest at 10 to 15 kts with a few gusts
possible in the afternoon.
Smith
&&
.PREV DISCUSSION...
ISSUED 252 PM CDT Mon May 12 2014
Warm and rather humid day across the forecast area today, with dew
points in the upper 60s to around 70 degrees and temperatures
mostly in the 80s. Air mass over our area is uncapped and CAPE`s
are from 3500-4000 J/kg in central Illinois, but so far convection
in our CWA has been spotty. More widespread showers/storms have
been occurring across the Ohio Valley. Main action has been
filling in across Iowa and the northwest half of Missouri, along a
cold front.
SHORT TERM...Tonight through Thursday:
Initial forecast concern is on the severe weather potential the
next several hours. The individual storms to our west have been
moving northeast with the overall area only slowly shifting
eastward. The HRRR and NMM high-resolution models have that
particular band of storms reaching the Illinois River around 6 to
7 pm and the I-55 corridor around 9 to 10 pm. Surface observations
over the area are not showing any meaningful boundary currently
present, thus the popcorn nature of the showers/storms so far.
Infrared and water vapor imagery showing some anti-cyclonic motion
over our CWA, which could be causing enough sinking of the air to
keep the showers under control so far. 0-6km shear values expected
to remain rather modest in most areas, so am thinking that the
storms will remain rather disorganized but briefly severe until
the main line gets here. Loss of daytime heating should weaken the
line of storms somewhat as it moves through tonight, but CAPE`s
remain 1000-2000 J/kg ahead of the front so there will still be
some instability to work with.
Morning model runs have the front roughly along the Indiana border
by midday, with threat of thunder diminishing from west to east
through the day. Have kept the dry weather west of I-55 for the
afternoon with likely PoP`s across east central and southeast
Illinois continuing in the afternoon. Temperatures across the east
will be slowly falling in the afternoon behind the front.
Long-advertised phasing of upper troughs in the north central and
southwest U.S. will try to take place the next couple days, although
the models keep them somewhat distinct through mid week.
Development of a surface low will take place Tuesday night across
the lower Mississippi Valley, and this low will be ejected
northeast on the nose of a developing 90-110 knot jet. Dry
northeast flow will erode the northern fringes of the rain shield
some, so will continue to focus the higher PoP`s on Wednesday
across the southeast half of the forecast area. As the surface low
moves northeast, a large upper low will develop over the upper
Mississippi Valley, so the threat of showers will continue even
after the main precipitation shield exits. High temperatures both
Wednesday and Thursday only expected to be in the upper 50s to
around 60 most areas due to the cooler air aloft and the rain.
LONG TERM...Friday through Monday:
The cool and showery weather will continue into Friday, before the
upper low starts to lift into Ontario and the upper pattern over
the U.S. flattens out somewhat. A fast moving wave in the upper
flow tracks an area of rain southeast later in the weekend, with
the ECMWF model about 12-18 hours faster and a bit further north.
Have limited PoP`s on Saturday night and Sunday to slight chances
across the south half of the forecast area, but this may need to
be bumped up if these trends persist on the next couple model
runs. A more substantial warming trend will occur early next week,
as ridging occurs across the Plains.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
332 AM CDT TUE MAY 13 2014
.SHORT TERM /TODAY/...
ISSUED AT 332 AM CDT TUE MAY 13 2014
MAIN FORECAST CONCERN TODAY WAS WITH MAX TEMPS AND CLOUD COVER.
AREA OF LOW PRESSURE LOCATED OVER LAKE SUPERIOR WILL CONTINUE TO
DRAG NORTHEAST INTO ONTARIO TODAY. DECENT CAA WILL PERSISTS
THROUGHOUT THE DAY DUE TO PRESSURE GRADIENT AIDED BY INCREASING
MIXING DURING THE AFTERNOON. LOW LEVEL MOISTURE GRADUALLY ERODES
FROM SOUTHWEST TO CENTRAL IOWA AND SHOULD SEE CLOUD COVER THIN OUT
AND LIFT IN THIS FASHION DURING THE AFTERNOON. HOWEVER...A
SECONDARY LOBE OF MID-LEVEL THETA-E ADVECTION WRAPS AROUND THE
SURFACE LOW LATE IN THE DAY AND LOOKS TO REINFORCE THE CLOUD COVER
OVER NORTHERN IOWA. THE 13.05Z HRRR AND 13.03Z HOPWRF ARE IN FAIR
AGREEMENT WITH THE PREVIOUS THINKING OF CLOUD COVER TRENDS...BUT
THINKING ARE SLIGHTLY TOO QUICK IN ERODING. WENT SLIGHTLY BELOW
MOS GUIDANCE FOR MAX TEMPS TODAY WITH THE CLOUD COVER AND CAA.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 332 AM CDT TUE MAY 13 2014
AFTER A WARM AND ACTIVE PERIOD THE PAST WEEK...WE WILL TURN AROUND
AND GO BACK TO A RELATIVELY COOL AND MOSTLY QUIET PERIOD FOR THE
NEXT 4 TO 5 DAYS. THOUGH NOT RAIN FREE...CHANCES FOR ANY ORGANIZED
SEVERE WEATHER WILL BE SLIM TO NONE. WITH THE RECENT RAINFALL SOME
RIVERS ARE RISING NOW BUT REMAINING IN BANK. THE H500 LOW NOW
OVER SOUTHERN CANADA WILL WOBBLE NORTHEAST WEDNESDAY WITH A
SECONDARY VORT MAX DIGGING SOUTHEAST ON THE BACK SIDE OF THE
SYSTEM OVER THE NEXT TWO DAYS. THIS WILL RESULT IN ANOTHER COLD
FRONT AND COLD POOL DROPPING SOUTH INTO MN AND IOWA BY LATE
WEDNESDAY NIGHT AND THURSDAY. MEANWHILE...TONIGHT SHOULD REMAIN
GENERALLY CLEAR TO PARTLY CLOUDY AS A WEAK RIDGE OF HIGH PRESSURE
SETTLES INTO THE AREA. TEMPS WILL BE QUITE COOL WITH THICKNESS
DROPPING TO 540 NORTH TO ABOUT 546 SOUTH. LOWS SHOULD RANGE FROM
THE MID TO UPPER 30S NORTH TO THE LOWER 40S SOUTH. BY EARLY
WEDNESDAY A WEAK UPSTREAM WAVE OVER THE NORTHERN PLAINS WILL DROP
SOUTH TOWARD IOWA...BRIEFLY ENHANCING WESTERLY FLOW ALOFT AND
INCREASING WARM AIR ADVECTION THROUGH THE AFTERNOON HOURS. THIS
WILL LIKELY SPREAD A CLOUDS ACROSS THE REGION WITH A FEW SHOWERS
AND ISOLATED THUNDERSTORMS NORTHWEST BY AFTERNOON. TEMPS WILL
RESPOND AND REACH THE LOWER 60S NORTH TO THE MID 60S CENTRAL AND
WEST. AS THE WEAK SFC BOUNDARY DROPS SOUTH THROUGH THE AREA WED
NIGHT IN RESPONSE TO THE STRENGTHENING NW FLOW ALOFT...CLOUDS WILL
OVERSPREAD THE REGION WED NIGHT AND CONTINUE INTO THURSDAY. THE
H500 COLD POOL THURSDAY IS BEING HANDLED DIFFERENTLY BY THE
GEM/EURO MODEL VS THE GFS/NAM. THE GEM/EURO ARE STRONGER AND
ESSENTIALLY PRODUCE A CUTOFF LOW OVER THE GREAT LAKES WHILE THE
GFS/NAM ARE KEEPING A WEAKER...OPEN WAVE OVER THE AREA.
CLIMATOLOGY WOULD FAVOR THE COLDER...MORE CLOSED SOLUTION SO WILL
TREND TOWARD COLDER...CLOUDIER...AND MORE SHOWERY FOR THURSDAY. IN
FACT LAPSE RATES REMAIN STEEP ENOUGH WITH THE COLD POOL ON
THURSDAY TO PRODUCE LATE MORNING THROUGH AFTERNOON THUNDERSTORMS.
WITH FREEZING LEVELS AS LOW AS FORECAST...MAY SEE SOME SMALL
HAIL/SLEET OR VERY COLD RAIN WITH A FEW OF THE STORMS THURSDAY IF
DOWNDRAFTS BECOME STRONG ENOUGH. VERY LITTLE CHANGE IS EXPECTED
THROUGH FRIDAY WITH NW FLOW CONTINUING WITH THE H500 LOW IN THE
AREA. ADDITIONAL CHANCES FOR ISO THUNDER ARE AGAIN POSSIBLE FRIDAY
AFTERNOON AS DAYTIME HEATING INCREASES INSTABILITY. TEMPS THURSDAY
AND FRIDAY WILL STRUGGLE TO REACH THE MID 50S NORTH TO UPPER
50S/LOWER 60S SOUTH AS CLOUDS BUILD DURING THE DAYTIME HOURS. THE
UPPER LEVEL LOW WILL FINALLY PULL EAST BY SATURDAY WITH A
FLATTENING OF THE FLOW TO OUR WEST. THIS WILL ALLOW FOR WARM AIR
ADVECTION TO INCREASE ACROSS IOWA INTO THE WEEKEND. WITH A GREAT
LAKES HIGH STILL HOLDING ON SUNDAY MAINLY DRY CONDITIONS ARE
EXPECTED THROUGH THE WEEKEND. THOUGH UNCERTAINLY ON TIMING IS
INCREASING TOWARD THE END OF THE FORECAST...A LARGE SCALE TROUGH
WILL ENTER THE PACNW SUNDAY AND INCREASE THETAE ADVECTION ACROSS
THE PLAINS LATE ON SUNDAY INTO MONDAY. THIS SHOULD INCREASE TEMPS
AND CHANCES FOR THUNDER INTO MONDAY. TRENDS OF THE GEM/EURO
CONFIRM INCREASING MOISTURE BY THE END OF THE WEEKEND AND
ESPECIALLY ON MONDAY WITH MORE ORGANIZED CONVECTION. HIGHS SUNDAY
WILL REACH 70 WITH LOWER 70S ON MONDAY. NEXT WEEK LOOKS MUCH MORE
ACTIVE ONCE AGAIN.
&&
.AVIATION...13/06Z
ISSUED AT 1207 AM CDT TUE MAY 13 2014
MAINLY HIGHER IFR/LOW MVFR CIGS TO REMAIN OVERNIGHT AND LIFT TO
VFR TOWARD DAYBREAK/TUESDAY MORNING. NORTHWESTERLY WINDS TO REMAIN
GUSTY TONIGHT INTO TUESDAY...AND WILL DIMINISH WITH SUNSET TUESDAY
EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...REV
AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS JACKSON KY
114 AM EDT TUE MAY 13 2014
.UPDATE...
ISSUED AT 114 AM EDT TUE MAY 13 2014
SOME VALLEY LOCATIONS ALREADY APPROACHING THEIR OVERNIGHT LOWS...SO
WILL DROP THESE VALLEYS INTO THE UPPER 50S FOR LOWS.
OTHERWISE...FORECAST IS ON TRACK WITH VERY LITTLE GOING ON OVERNIGHT.
HRRR AND RAP BOTH SUPPORT DRY CONDITIONS WELL INTO THE MORNING AND
EVEN INTO THE EARLY AFTERNOON HOURS. THUS...HAVE BACKED OFF POPS
UNTIL MID TO LATE AFTERNOON. EVEN THEN...PROBABLY NOT LOOKING AT
ANYTHING MORE THAN WHAT WE SAW YESTERDAY...SO CHANCES WILL REMAIN
VERY SMALL.
UPDATE ISSUED AT 1049 PM EDT MON MAY 12 2014
SKIES HAVE CLEARED OUT ACROSS EASTERN KENTUCKY...AND ONLY A FEW
STORMS ARE STILL ONGOING ACROSS THE EASTERN TENNESSEE TERRAIN. WILL
KEEP THINGS DRY THROUGH THE REST OF THE OVERNIGHT...WITH PERHAPS A
FEW MORE CLOUDS RETURNING AT THE MID-LEVELS TOWARDS DAWN. LOWS WILL
BOTTOM OUT IN THE 60 TO 65 DEGREE RANGE FOR MOST...WITH AREAS OF
VALLEY FOG A BIT MORE ESTABLISHED COMPARED TO LAST NIGHT...WITH
BETTER MOISTURE AND LESS CLOUD COVER IN PLACE.
UPDATE ISSUED AT 804 PM EDT MON MAY 12 2014
MOST CONVECTION HAS WOUND DOWN ACROSS THE AREA EARLY THIS
EVENING...HOWEVER THERE ARE A FEW ISOLATED RETURNS REMAINING CLOSE BY
AND WILL LET THE CURRENT THE FORECAST RIDE FOR NOW...KEEPING SLIGHT
CHANCE POPS GOING THROUGH AROUND 10 PM. DID FRESHEN UP THE HOURLY
SKY COVER...TEMPERATURES...AND DEW POINTS TO ACCOUNT FOR THE LATEST
TRENDS IN OBSERVATIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 301 PM EDT MON MAY 12 2014
THE MODELS HAVE NOT HAD THE BEST HANDLE ON THE SHOWER AND STORM
ACTIVITY THAT HAS BEEN ONGOING ACROSS EASTERN KENTUCKY THIS
AFTERNOON. THE LATEST TIME HEIGHTS AND SOUNDINGS SHOWED VARYING
AMOUNTS OF CLOUDS AND PRECIPITATION. WITH THE AMOUNT OF UNCERTAINTY
INVOLVED HERE...A GENERAL 20 PERCENT POP HAS BEEN INCORPORATED INTO
THE FORECAST THROUGH ABOUT 2Z TONIGHT. THERE SIMPLY DOES NOT APPEAR
TO BE ENOUGH INSTABILITY PRESENT TO SUPPORT MORE THAN ISOLATED
SHOWERS AND STORMS. CONDITIONS LOOK A BIT MORE PROMISING FOR
TUESDAY...AS A WARM FRONT LOOKS TO MOVE ACROSS THE AREA. SHOWERS AND
STORMS WILL BREAK OUT ALONG THIS FRONT TUESDAY AND TUESDAY NIGHT.
ONCE AGAIN THERE IS SOME DISAGREEMENT AS TO THE TIMING OF
PRECIPITATION EVOLUTION AND AMOUNTS AMONGST THE MODELS.
THEREFORE...DECIDED TO GO WITH A 30 TO 40 PERCENT CHANCE OF RAIN FOR
TOMORROW AND TOMORROW NIGHT...AS THE LIKELY POPS SHOWING UP IN THE
LATEST METMOS GUIDANCE SEEMS TO HIGH BASED ON RECENT TRENDS IN REAL
TIME WEATHER. TEMPERATURES THE NEXT COUPLE OF DAYS WILL ONCE AGAIN BE
RUNNING WELL ABOVE NORMAL WITH HIGHS TOMORROW TOPPING OUT IN THE LOW
TO MID 80S AND OVERNIGHT LOWS IN THE LOWER 60S. FOG WILL BE A
DISTINCT POSSIBILITY AGAIN LATE TONIGHT INTO EARLY TOMORROW MORNING.
THE FOG COULD BE LOCALLY DENSE AT TIMES...PARTICULARLY IN OUR DEEPER
AND MORE SHELTERED VALLEYS AND NEAR BODIES OF WATER.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 301 PM EDT MON MAY 12 2014
MODELS CONTINUE TO TRACK TOWARDS A COMMON SOLUTION WITH A MORE
CONSISTENT ECMWF LEADING THE WAY. TO START THE EXTENDED WE ARE WELL
INTO THE BEGINNINGS OF A PATTERN CHANGE. NORTHERN AND SOUTHERN
STREAMS UNDERGO PHASING OVER THE CENTRAL AND EASTERN CONUS DURING
THE FIRST 48 HOURS OF THE EXTENDED. THE END RESULT IS A BROAD
EASTERN CONUS TOUGH WITH ITS PARENT CUTOFF LOW OVER THE GREAT LAKES
REGION. BY DY6...SUN THE 0Z ECMWF LIFTS THE LOW UP OVER THE HUDSON
BAY AREA OF CANADA. THE 12Z GFS HAS TRENDED TOWARDS THIS IDEA BUT
CONSISTENTLY TRIES TO SHIFT THE LOW BACK TOWARDS THE SE TO THE
ATLANTIC COAST. THE ECMWF REDEVELOPS A DIGGING LOW OVER THE SAME
REGION BUT MORE AS THE RESULT OF ADDITIONAL ENERGY ROTATING AROUND
THE BASE OF THE LARGER TROUGH. SAME ENDS...DIFFERENT MEANS. BY THE
END OF THE EXTENDED...PATTERN AMPLIFIES EVEN MORE WITH SOMEWHAT
SHARP LONG WAVE RIDGING DEVELOPING OVER THE OHIO AND TN VALLEY
REGIONS. THE GFS KEEPS A MORE BLUNTED RIDGE FURTHER WEST OVER THE
UPPER MIDWEST...EASTERN PLAINS. OVERALL PATTERN IS RELATIVELY SLOW
FOR SPRING BUT STILL PROGRESSIVE.
AT THE SURFACE WE FIND A FRONTAL BOUNDARY OVER OUR AREA AT THE START
OF THE EXTENDED. THIS BOUNDARY STALLS OUT ACROSS EASTERN KENTUCKY
AS A WAVE OF SFC LOW PRESSURE DEVELOPS OVER THE DEEP SOUTH AND RIDES
ALONG THE BOUNDARY AND ACROSS OUR CWA LATE WED...WED NIGHT. THE
FRONTAL BOUNDARY THEN SHIFTS EAST OF OUR AREA DURING THE DAY
THURSDAY AS THE SFC LOW LIFTS TO THE NORTHEAST. SFC HIGH PRESSURE
THEN BUILDS INTO THE OHIO VALLEY REGION FOR THE WEEKEND.
FOR SENSIBLE WEATHER...WED WILL BE OUR LAST DAY OF ABOVE NORMAL
TEMPS BEFORE A DRASTIC COOL OFF THAT WILL LAST THROUGH THE REMAINDER
OF THE FORECAST WINDOW. DEPENDING ON THE SURFACE PATTERN AND SKY
CONDITIONS...SATURDAY MORNING COULD WIND UP BEING QUITE CHILLY WITH
LOWS IN OUR COLDEST VALLEY FLIRTING WITH THE UPPER 30S AS H850 TEMPS
BOTTOM OUT BETWEEN ZERO AND 3C. IN GENERAL HIGHS WILL RUN ABOUT 5 TO
15 DEGREES BELOW NORMAL. CLOUD COVER WILL TEND TO KEEP MINIMUMS
WITHIN 5 TO 10 DEGREES OF NORMAL.
CAN NOT TOTALLY RULE OUT THE POTENTIAL FOR SOME SEVERE WEATHER
WEDNESDAY INTO WED NIGHT AS THE SYSTEM IS SHOWING SIGNS OF BECOMING
BETTER ORGANIZED. HOWEVER...ATTM BASED ON CURRENT FORECAST SOUNDINGS
BELIEVE THE THREAT IS LIMITED OVER OUR CWA DUE TO A LACK OF STRONGER
DYNAMICS. INITIALLY SFC INSTABILITY IS DECENT ENOUGH BUT WINDS AT
THE SFC AND ALOFT ARE NOT STRONG. BULK SHEAR PARAMETERS ARE MARGINAL
WITH A RELATIVELY UNIDIRECTIONAL FLOW. ALSO...MOST OF ANY SHEAR IS
CONFINED TO THE LOWEST 3KM/10K FT. THUS INDICATIONS ARE SUCH THAT IF
SOMETHING DID GET GOING SEVERE THREAT WOULD COME MAINLY FROM BOWING
CELLS...CLUSTERS AND/OR LINE SEGMENTS.
DYNAMICS ARE MORE FAVORABLE BY LATE IN THE DAY WEDNESDAY...AND
WEDNESDAY NIGHT BUT BEST INSTABILITY WILL BE DECREASING WITH TIME. A
RELATIVELY LOW SFC BASED INSTABILITY...HIGHER PWATS APPROACHING THE
CLIMATOLOGICAL 90TH PERCENTILE AT ABOUT 1.5 INCHES...AND A FAVORABLE
UPPER LEVEL RIGHT REAR ENTRANCE JET WILL MEAN EFFICIENT RAINERS FOR
THAT PORTION OF THE FORECAST. SO EXPECT RESULTANT QPE COULD BE
PRETTY DECENT WED NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 114 AM EDT TUE MAY 13 2014
VFR CONDITIONS WILL LIKELY PERSIST THROUGH THE OVERNIGHT PERIOD AT THE
TAF SITES. SOME VALLEY FOG WILL DEVELOP...ESPECIALLY IN THE
EAST...BUT RIDGETOP AIRPORTS SHOULD BE UNAFFECTED. SCATTERED CU WILL
DEVELOP AGAIN TODAY...WITH A STRAY SHOWER OR STORM POSSIBLE.
HOWEVER...LIKE YESTERDAY...CONFIDENCE IS SMALL FOR ANYTHING AFFECTING
THE TAF STIES...SO WILL LEAVE OUT THE MENTION OF SHOWERS AND STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...AR
LONG TERM...RAY
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1255 AM EDT TUE MAY 13 2014
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL MOVE SOUTHEAST OF THE REGION
OVERNIGHT. HIGH PRESSURE WILL MOVE ON IN TUESDAY INTO WEDNESDAY
WITH MILDER TEMPERATURES. LOW PRESSURE AND A COLD FRONTAL BOUNDARY
WILL VERY SLOWLY APPROACH THE REGION FROM QUEBEC PROVINCE LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
1252 AM UPDATE...CLEARING CONTINUES AS HIGH PRES TO THE NW WORKS
ITS WAY SE OVERNIGHT. ADJUSTED THE HRLY TEMPERATURES DOWN AS
CLEARING HAS ALLOWED READINGS TO DROP OFF FASTER THAN PREVIOUSLY
FORECAST. SOME COLD TEMPERATURES ARE EXPECTED BY SUNRISE TUESDAY
MORNING AND THE LATEST FORECAST LOOKS IN GOOD SHAPE. SOME AREAS,
ESPECIALLY THE LOW LYING AREAS COULD SEE READINGS DROP INTO THE
UPPER 20S W/SOME FROST. KEPT THE MENTION OF THE PATCHY FOG IN THE
FORECAST, BUT EXTENDED IT IN AREAL COVERAGE INTO PORTIONS OF THE
CENTRAL HIGHLANDS. LAPS SOUNDINGS SUPPORTED BY THE RAP INDICATE
SOME LLVL MOISTURE BELOW 1500 FT THROUGH EARLY MORNING. T
PREVIOUS DISCUSSION...
WITH MORE IN THE WAY OF SUNSHINE...AT LEAST NRN PTNS OF THE FA...
WHICH WERE SHUT OUT OF THE SUN AND WARMTH THIS AFTN...WILL RECOVER
TO NEAR SEASONAL HI TEMPS...WHILE INTERIOR SW PTNS OF THE FA WHICH
ENJOYED WHAT WAS LEFT OF WARMER AIR AHEAD OF A BACK DOOR COLD
FRONT... WILL BE A LITTLE COOLER TUE AFTN THAN THIS AFTN.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
A FULL LATITUDE RIDGE AXIS BUILDS ALONG THE EAST COAST ON
WEDNESDAY. A WARM FRONT WILL BRING RAIN TO EASTERN MAINE ON
WEDNESDAY...ESPECIALLY THE NORTHEAST CORNER.
THE RIDGE AXIS SHIFTS INTO THE WESTERN ATLANTIC OCEAN ON THURSDAY
WHICH WILL PUT EASTERN MAINE FIRMLY IN THE WARM SECTOR WITH A
SOUTHERLY SURFACE FLOW. TEMPERATURES WILL BE ABOVE NORMAL EXCEPT
NEAR THE COAST. CANNOT RULE OUT INSTABILITY SHOWERS DURING THE
DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A PERSISTENT UPPER LEVEL TROUGH OF LOW PRESSURE OVER THE GREAT LAKES
REGION COMBINED WITH UPPER LEVEL RIDGING TO OUR EAST WILL KEEP THE
WEATHER UNSETTLED LATE THIS WEEK AND THROUGH NEXT WEEKEND. RIDGING
IN THE ATLANTIC IS EXPECTED TO BACK WESTWARD INTO THE AREA THURSDAY
NIGHT INTO FRIDAY BRINGING WARM AND HUMID CONDITIONS ACROSS THE
AREA WITH VARIABLE CLOUDINESS AND SMALL CHANCES FOR ISOLATED SHOWERS
OR THUNDERSTORMS. THE ATLANTIC HIGH SHOULD THEN PUSH OUT TO SEA ON
SATURDAY AS THE UPPER LOW OVER THE GREAT LAKES PUSHES A FRONTAL
BOUNDARY INTO OUR AREA. THIS WILL BRING CHANCE FOR SHOWERS AND
PERHAPS A THUNDERSTORM ON SATURDAY. THE BOUNDARY IS EXPECTED TO
STALL OVER THE AREA SUNDAY INTO MONDAY AS THE UPPER LOW REMAINS JUST
TO OUR WEST. THIS WILL BRING CONTINUE CHANCES FOR SHOWERS SUNDAY AND
MONDAY WITH TEMPS NEAR NORMAL TO PERHAPS A COUPLE DEGREES BELOW
NORMAL.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: IFR AT KFVE AS OF 01Z WITH MVFR AT THE OTHER NORTHERN
MAINE TAF SITES. CONDITIONS SHOULD TRANSITION TO VFR LATER TONIGHT
AFTER 04Z WITH DOWNEAST SITES REMAINING VFR. CANNOT RULE OUT
BRIEF MVFR OR IFR VSBYS WITH PATCHY VLY FOG SPCLY AT KPQI AND KHUL
VERY LATE TNGT TO ABT SUNRISE TUE...OTHERWISE VFR CONDITIONS CONTG
ALL SITES ON TUE.
SHORT TERM: IFR OR MVFR CIGS AND VSBYS CAN BE EXPECTED IN RAIN AND
FOG ACROSS MAINLY THE NORTHERN TAF SITES ON WEDNESDAY. MVFR TO VFR
CONDITIONS ARE LIKELY THURSDAY WITH MVFR CONDITIONS FRIDAY AND
SATURDAY. FOG MAY LOWER CONDITIONS TO IFR IN SOME SIGHTS EARLY
THURSDAY, FRIDAY AND SATURDAY MORNINGS ESPECIALLY DOWNEAST.
&&
.MARINE...
NEAR TERM: NO HDLNS REQUIRED FOR THE NEAR TERM...WITH WVS AND
WINDS SLOWLY DIMINISHING LATE TNGT THRU TUE AFT A PD OF NE 10 TO
20 KT WINDS THIS EVE. USED A MODEL/MOS BLEND FOR WINDS AND KEPT
CLOSE TO WW3 WV GUIDANCE FOR WINDS.
SHORT TERM: AN SCA WILL LIKELY BE NEEDED FOR THURSDAY WITH WAVE HEIGHTS
UP TO SIX FEET IN A STRONG SOUTHERLY FLOW.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS GRAY ME
1206 AM EDT TUE MAY 13 2014
.SYNOPSIS...
A BACK DOOR COLD WILL COTNINUE TO PUSH SOUTHWEST OF THE REGION
OVERNIGHT. COOLER HIGH PRESSURE WILL THEN BUILD IN FROM THE
NORTHEAST TUESDAY AND WEDNESDAY. HIGH WILL MOVE OFF THE COAST LATE
WEDNESDAY. A SLOW MOVING COLD FRONT WILL APPROACH THE REGION
SATURDAY AND SHOULD PASS TO OUR EAST BY SUNDAY. THERE IS SOME
POTENTIAL FOR HEAVY RAINFALL AROUND SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
MIDNIGHT...BACK DOOR FRONT IS PUSHING THROUGH SRN NH ATTM. IT
WORKED ALONG THE COAST FIRST CLOSER TO 00Z...AND NOW HAS PUSHING
INLAND IN A DENSITY DRIVEN CURRENT SIMILAR TO SEA BREEZE. A FEW
SPRINKLES HAVE POPPED UP ON THE WARM SIDE OF THIS BOUNDARY IN
CENTRAL NH...BUT ARE QUICKLY BEING UNDERMINED BY THE MARINE AIR
AS IT WORKS INLAND...SO THESE SHOULD END BY 06Z...AND THIS IS
SUPPORTED BY THE HRRR WHICH IS THE ONLY MODEL TO PICK UP ON THIS.
OTHERWISE JUST SOME MINOR TWEAKS TO TEMPS/SKY BASED ON LATEST OBS.
PREV DISC;
AT 18Z...THE BACKDOOR FRONT WAS DRAPED ACROSS OUR
NORTHERN AND EASTERN ZONES. THE WESTERLY DOWN SLOPE FLOW AHEAD OF
THE FRONT HAD ALLOWED TEMPERATURES TO WARM INTO THE 70S AND LOWER
80S ACROSS THE FORECAST AREA. THE FRONT WILL PRESS SOUTHWEST
ACROSS THE AREA OVERNIGHT BEFORE STALLING WELL SOUTH AND WEST OF
THE FORECAST AREA.
&&
.SHORT TERM /TONIGHT/...
MUCH COOLER ON TUESDAY WITH THE ONSHORE FLOW AROUND THE SURFACE
HIGH. CLOUDS FROM THE STALLED FRONTAL BOUNDARY WILL BE THICKEST
ACROSS SOUTHERN AND WESTERN SECTIONS...WHERE THOUGH COULD BE A
STRAY SHOWER OR TWO...WITH THE MOST ABUNDANT SUNSHINE FOUND OVER
NORTHERN AND EASTERN SECTIONS. HIGHS WILL RANGE FROM THE MID 50S
TO LOWER 60S...OR SOME 20 TO 25 DEGREES COOLER THEN MONDAY.
LITTLE CHANGE TUESDAY NIGHT...EXCEPT THE THICKER CLOUD WILL SPREAD
A BIT FURTHER NORTH AND EAST ALONG WITH THE CHANCE FOR A FEW
SHOWERS. LOWS WILL BE MAINLY IN THE 40S. THERE COULD BE SOME
STRATUS...FOG...AND DRIZZLE TOWARDS DAWN NEAR THE COAST IN THE
LIGHT BUT PERSISTENT ONSHORE FLOW.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
THE EXTENDED PORTION OF THE FORECAST WILL FEATURE UNSETTLED WEATHER
AS A DEEP LAYER SOUTHERLY MERIDIONAL FLOW SETS UP STARTING ON
WEDNESDAY AND LOOKS TO LAST INTO THE WEEKEND.
STRONG MARITIME HIGH PRESSURE WILL MOVE OFFSHORE ON WEDNESDAY AND
WILL ALLOW A WARM FRONT TO PUSH NORTHWARD BY THURSDAY. WEAK FORCING
FOR ASCENT WILL ACCOMPANY THE WARM FRONT AND PROVIDE AT LEAST
SCATTERED SHOWERS...ESPECIALLY ACROSS THE INTERIOR. PLENTY OF CLOUDS
WILL BE LIKELY ELSEWHERE. FOG AND DRIZZLE PROBABLY SETS UP ALONG THE
COAST BY WEDNESDAY NIGHT.
BROAD WARM SECTOR OVER THE AREA ON THURSDAY WILL RESULT IN
INCREASINGLY WARM AND HUMID CONDITIONS. TEMPERATURES SHOULD TOP OUT
WELL INTO THE 70S AWAY FROM THE COAST. DEEP LAYER RIDGING SHOULD
KEEP US DRY FOR MUCH OF THE DAY ALTHOUGH A FEW SHOWERS AND PERHAPS A
THUNDERSTORM WILL BE POSSIBLE. SAME GENERAL SETUP IS EXPECTED ON
FRIDAY...ALTHOUGH MORE OF AN ONSHORE COMPONENT TO THE SFC WIND
SHOULD PROVIDE COOLER...BUT CONTINUED MOIST CONDITIONS. THE CHANCE
OF SHOWERS WILL INCREASE FROM WEST TO EAST DURING THE DAY AS
SLOW-MOVING FRONTAL SYSTEM APPROACHES. MUCH OF THE DAY WILL BE
CLOUDY WITH SOME FOG AND DRIZZLE AS WELL...ESPECIALLY AT THE COAST.
COLD FRONT APPROACHES OUR WESTERN DOORSTEP FRIDAY NIGHT AND
SATURDAY...WITH RIBBON ON HEAVY SHOWERS/POSSIBLE THUNDER LIKELY AS
FRONT INTERACTS WITH DEEP LAYER SOUTHERLY FLOW. HEAVY RAINFALL WILL
BE POSSIBLE SATURDAY...WITH OVER AN INCH LIKELY. THIS WILL CONTINUE
INTO SATURDAY NIGHT AS THE FRONT IS SLOW TO MOVE OUT. IMPROVEMENT
MAY BE SEEN ON SUNDAY DEPENDING ON THE SPEED OF THE FRONT AND THE
STUBBORN UPPER LOW TO THE WEST.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 11Z WED/...VFR EXPECTED THROUGH TUE. AREAS OF MVFR
TUE NIGHT IN CLOUDS AND PATCHY DRIZZLE AND FOG NEAR THE COAST.
LONG TERM...WEDNESDAY THROUGH SATURDAY...VARYING CONDITIONS WILL BE
SEEN THROUGHOUT THE PERIOD AS DEEP LAYER SOUTHERLY FLOW PERSISTS.
THIS MEANS BOUTS OF FOG AND STRATUS WILL BE LIKELY...ESPECIALLY ON
THE COASTAL PLAIN. THE PERIOD MAY FEATURE PREVAILING MVFR TO IFR
CONDITIONS THERE. HEAVY RAIN IS POSSIBLE BETWEEN LATER FRIDAY NIGHT
AND SATURDAY NIGHT AT ALL TERMINALS...AND LOW CONDITIONS ARE
EXPECTED THEN.
&&
.MARINE...
SHORT TERM /THROUGH TUESDAY NIGHT/...NO FLAGS. BRIEF SURGE OF NE WINDS
BEHIND BACKDOOR COLD FRONT THIS EVENING COULD PRODUCE A FEW GUSTS
TO NEAR 25 KT IN THE OPEN WATERS. HIGH PRESSURE BUILDS OVER THE
WATERS TUE AND TUE NIGHT...WITH WINDS BECOMING LIGHT.
LONG TERM...
INCREASING SOUTHERLY FLOW LATE IN THE WEEK AND INTO
SATURDAY WILL RESULT IN BUILDING SEAS BY THE WEEKEND. SCA CONDITIONS
ARE LIKELY BY LATE WEEK.
&&
.FIRE WEATHER...
LIGHT ONSHORE WINDS...MUCH COOLER TEMPERATURES...AND HIGHER
RELATIVE HUMIDITY VALUES SHOULD MARKEDLY REDUCE FIRE DANGER OVER
THE NEXT FEW DAYS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
354 AM EDT TUE MAY 13 2014
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OFFSHORE THROUGH THE REST OF THE WEEK.
A COLD FRONT OVER SOUTHERN NEW ENGLAND WILL SLIDE SOUTH INTO THE
NORTHERN MID ATLANTIC TONIGHT. A LARGER COLD FRONT EXTENDING FROM
WISCONSIN TO TEXAS WILL TRACK SLOWLY EAST...MOVING INTO THE MID
ATLANTIC STATES THURSDAY AND FRIDAY. HIGH PRESSURE IS EXPECTED TO
RETURN TO THE MID ATLANTIC THIS WEEKEND.
&&
.NEAR TERM /TODAY/...
WE ARE WATCHING THE TRW PRSNTLY IN THE NWRN CORNER OF THE CWA.
ALTHOUGH THERE WASN`T MUCH FOG THIS EVE DUE TO THE MON RA FOLLOWED
BY CLR SKIES...OVRNGT THAT WHICH WAS THERE HAS BEEN PATCHY AT BEST.
SUNRISE IS NOW OCCURRING B4 6 AM...SO THERE ISN`T A LOT OF TIME
LEFT FOR NOCTURNAL FOG TO DVLP. SUN WL RISE B4 6 AM HERE UNTIL
JUL 22.
SYNOPTIC STIUATION IS INTERESTING - LOW PRES OVR WI W/ A CD FNT
WHICH XTNDS ALL THE WAY TO NRN MEX. A WARM FNT XTNDS INTO SRN
QUEBEC...W/ A CD FNT STRETCHING FM THAT ACROSS NEW ENGLAND. AT 2
AM TEMPS ARE FALLING IN NEW ENGLAND QUITE QUICKLY AS THE BACKDOOR
FNT TRACKS SWD - BOS DROPPED FM 74 TO 55 IN ONE HR WHEN WINDS
SHIFTED FM W TO NE. ORH...FURTHER INLAND..XPRNCD A SIMILAR DROP.
THE BACKDOOR FNT IS XPCTD TO MAKE IT THRU NYC THIS MRNG...AND ONTO
THE DELMARVA THIS AFTN. QUSTN THEN BECOMES HOW FAR W WL THE FNT
MAKE IT? HRRR SHOWS AN ERLY WIND SURGE ON THE WRN SIDE OF THE CHES
BAY BY ERLY AFTN...WHILE THE 00Z ECM AND GFS SHOW A LATER ARRIVAL
TIME. IF THE HRRR IS CORRECT THIS COULD LEAD TO A WIDER DISPARITY
IN AFTN TEMPS...W/ THE CENTRAL SHEN VLLY REACHING THE U80S AND THE
LAND AGAINST BAY ONLY GETTING TO THE L80S...AND PSBLY FALLING INTO
THE 70S BY LATE AFTN.
GIVEN THE AMPLE LO LVL MOISTURE AND XPCTD SFC HTG RW/TRW ARE PSBL
THIS AFTN...AND A BACKDOOR FNT WOULD PROVIDE A BNDRY FOR FORMATION. AS W/
YDA THERE WL BE CAPE ABV 1000 THIS AFTN BUT UPR LVL WIND FIELD IS
MICROSPCOPIC. PULSE STORMS WOULD BE THE WORSE CASE SCENARIO.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AND IT APPEARS THAT BACKDOOR FNT WL AT BEST MAKE IT INTO THE NERN
CORNER OF THE CWA OVRNGT B4 BEING PUSHED BACK TO THE N WED AHD OF
THE MORE PROMINENT APRCHG SYSTEM FM THE W. LINGERING CHC POPS THIS
EVE B4 A NGT W/ LOWS IN THE 60S. PTCHY FG WL BE PSBL BUT AGN THIS
IS NOT XPCTD TO BE WIDESPREAD.
BY WED THE UPR RDG WL BE MOVG OFF THE CST AND CLDS WL BE INCRSG
HERALDING THE APRCH OF THE SYSTEM WHICH WL BE CONTROLLING THE AREA
WX FOR THE FINAL 2 DAYS OF THE WORKWK. HIGH TEMPS XPCTD TO DROP
BACK INTO THE 70S. DURG THE DAY PCPN CHCS WL BE INCRSG FM W TO E.
SVR THREAT WL RMN LOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AN ANOMALOUSLY DEEP UPPER TROUGH WILL MAKE A SECONDARY PUSH DOWN
INTO THE SOUTHEAST LATE THIS WEEK. A FEATURE THIS STRONG MOVING THIS
FAR SOUTH NEARLY ALWAYS WILL TAP INTO AMPLE GULF MOISTURE. FROM LATE
WED INTO THU...THE UPPER VORT MAX WILL SLIDING OVER THE OZARKS INTO
THE MID MS VLY...W/ A LARGE SECTION OF THE DEEP SOUTH UNDER BUILDING
AREAS OF PRECIP. INITIALLY POORLY ORGANIZED AS THE DYNAMICS ARE
SETTING UP...WE`LL BEGIN TO SEE POCKETS OF HEAVY RAIN MOVE UP THE
SRN/CNTRL APLCNS DURING THE DAYTIME HRS THU. THIS WILL ACTUALLY DRY
OUT OUR IMMEDIATE AREA...W/ ONLY A FEW HANDFULS OF WEAK AND
SCATTERED SHOWERS DRIFTING AROUND THE REGION.
A WARM FRONT WILL BE SLIDING ACROSS THE AREA EARLY THU...STARTING TO
MIX-OUT THE WEDGE OVER NERN MD/DC METRO AREA FROM WED. THE FRONT
WILL NEED TO MOVE THRU FOR ANY AMOUNT OF INSTABILITY TO DEVELOP OVER
THE DC/BALT METRO AND I-95 CORRIDOR. SKIES WILL REMAIN OVERCAST FOR
THE REGION ON THU...BUT THAT WON`T PREVENT SFC TEMPS FROM CLIMBING
WELL INTO THE 70S AND EVEN L80S BY MID AFTN. S-SELY WINDS WILL BE
BREEZY INTO THE 15-25MPH RANGE AND EVEN GUSTIER THRU THE LOW LEVELS
OF THE ATMOS. THE STRONG LOW LEVEL FLOW WILL ADD THE OTHER ELEMENT
OF CONVECTIVE POTENTIAL - WHEREAS THE INSTABILITY WILL BE LACKING
THROUGHOUT THE BUILD-UP AND PASSAGE OF THE INCOMING UPPER TROUGH.
FROM LATE THU INTO MIDDAY FRI...WAVES OF MODERATE TO HEAVY RAIN WILL
APPROACH AND MOVE ACROSS THE REGION. EMBEDDED AREAS OF HEAVIER
ACTIVITY LIKELY ELEVATED CONVECTION WILL ADD THE ELEMENT OF MIXING
DOWN ISOLATED GUSTY TO POSSIBLY DAMAGING WINDS - ESPEC ON FRI AFTN.
THE MAIN CONCERN HOWEVER IS FLOODING FROM THE 1-3 INCHES OF EXPECTED
QPF...LOCALLY HIGHER. THE SFC SYSTEM NOT QUITE IN CONSENSUS AMONGST
THE MED RANGE MEMBERS...BUT A TREND TOWARD THE SFC LOW LOOKS TO
TRACK NEAR THE AREA DURING THE FIRST-HALF OF THE DAY ON FRI. THE
TRACK OF THE STRONGER OF THE SFC LOWS WILL DETERMINE THE CONVECTIVE
POTENTIAL FOR THE AREA. THE MORE OF OUR AREA THAT IS SOUTH AND EAST
OF THE LOW - THE BETTER THE POTENTIAL FOR INSTABILITY AND STRONGER
CONVECTION. THE FURTHER SOUTH THE LOW IS RELATIVE TO OUR
REGION...THE MORE GENERAL STRATIFORM AND MAINLY WIDESPREAD MODERATE
RAIN.
THE UPPER TROUGH POWERING THE SYSTEM WILL BEGIN TO MAKE A NEGATIVE
TILT LATE FRI...ADDING MORE POTENCY TO THE OVERALL SYSTEM BUT ALSO
ACCELERATING THE MOISTURE AXIS TOWARD THE ERN SEABOARD DURING THE
LATE NIGHT HRS. CONDITIONS WILL DRY OUT QUICKLY AS THE WAVE OF
SUBSIDENCE AND COOLER AIR PUSHES INTO THE BACK SIDE OF THE PRECIP.
AN UPPER LOW DRIFTING DOWN FROM SOUTH OF THE HUDSON BAY AROUND WILL
ROTATE AROUND THE GREAT LAKES INTO THE COMING WEEKEND...KEEPING OUR
AREA QUITE COOL AND RELATIVELY DRY. THE "WEATHER" FROM THIS FEATURE
WILL MAKE IT FEEL MORE LIKE MARCH THAN MAY...EVEN THOUGH AVG TEMPS
FOR MID-MAY ARE IN THE M70S. A SLOW MOVING AND COLD UPPER LOW TAKING
A FEW DAYS TO EXIT THE NORTHEAST WILL KEEP US IN THIS PATTERN WELL
INTO NEXT WEEK. IT MAY BE SEVERAL MORE DAYS BEFORE WE GET ANYWHERE
CLOSE TO 80 DEG OR MORE...BASED ON THE PATTERN SETTING UP FOR NEXT
WEEK.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
BULK OF THE NEXT 24 HRS SHOULD HV VFR CONDS. 2 CONCERNS WL BE
AFTN/EVE TSTMS...ALTHO SVR THREAT WL BE LOW...AND THEN PSBLTY OF
PTCHY FOG AT IAD/MRB/CHO AFTR MDNGT. GNRLY MAY IS NOT A BIG FOG
MONTH CLIMATOLOGICALLY.
CNVCTN WL AGN BE PSBL WED AHD OF A CD FNT CURRENTLY TRIGGERING
TSTMS FM WI TO NRN MEX. THIS WL BECOME A BIGGER PLAYER FOR E CST
AVIATION THU AND FRI.
ANOTHER STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE REGION FROM
LATE THU INTO FRI. MAINLY PERIODS OF HEAVY RAIN WOULD BE THE
CONCERN...W/ BREEZY SFC WINDS BUT EVEN STRONGER LOW LEVEL FLOW - A
GOOD 30-50KT IN THE BOUNDARY LAYER OUT AHEAD OF THE SFC LOW LATE THU
INTO EARLY FRI. A COLD FRONT WILL PUSH THE PRECIP AND ANY EMBEDDED
TSTMS OFF THE COAST BY LATE FRI...W/ COOLER AND DRIER AIR BEING
USHERED IN FOR THE COMING WEEKEND.
&&
.MARINE...
HIPRES CENTERED OVER THE GULF OF MAINE WILL BUILD SWWD TOWARD THE
WATERS THIS AFTN AND TNGT...RESULTING IN WINDS BACKING FROM THE
EAST DURING THIS TIME. WIND SPEEDS SHOULD REMAIN BELOW SCA
THRESHOLD WITHOUT A FAVORABLE DIRECTION FOR CHANNELING. WINDS BCMG
SRLY WED AHD OF THE LARGER CD FNT.
A POTENT UPPER LEVEL TROUGH WILL GRADUALLY MOVE TOWARD THE REGION
FROM WED INTO THU...SPREADING PRECIP ALONG THE APLCNS BUT KEEPING
THE BAY/COAST RELATIVELY DRY UNTIL LATE THU. SFC WINDS HOWEVER WILL
START PUSHING WELL INTO SCA RANGE FROM EARLY THU ONWARD...UNTIL THE
EVENTUAL PASSAGE OF A COLD FRONT FRI EVE. GUSTY SLY WINDS WILL
CHANNEL UP THE MAIN STEM OF THE MD BAY...ALONG W/ THE PASSAGE OF
MODERATE TO HEAVY SHOWERS AND ISOLATED TSTMS FROM LATE THU INTO FRI
EVE.
BEHIND THE FRONT...WINDS WILL DROP OFF TO A LIGHT W/NW BREEZE THRU
THE WEEKEND.
&&
.TIDES/COASTAL FLOODING...
TIDAL SITES CURRENTLY NEAR ASTRONOMICAL TIDE ALONG THE WRN SHORE
OF THE CHSPK BAY AND TIDAL POTOMAC RIVER. POSITIVE TIDAL
ANOMALIES ARE EXPECTED TO DEVELOP TUE NGT AND WED AS THE ARRIVAL
OF A BACKDOOR COLD FRONT MARKS THE ONSET OF ONSHORE FLOW. MINOR
COASTAL FLOODING MAY DEVELOP LATE IN THE WEEK WHEN THESE POSITIVE
ANOMALIES INCREASE UNDER STRENGTHENING SLY FLOW AHEAD OF A SLOW-
MOVING COLD FRONT. ASTRONOMICAL TIDES WILL ALREADY BE HIGH WITH A
FULL MOON THIS WEEK.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
PRODUCTS...WOODY!/GMS/JRK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
508 AM EDT TUE MAY 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT TUE MAY 13 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED AN AMPLIFIED TROF
OVER THE CNTRL CONUS. WITHIN THE TROF...ONE SHORTWAVE WAS LIFTING
THRU NRN MN INTO NRN ONTARIO. ANOTHER SHORTWAVE WAS LINGERING IN THE
BASE OF THE TROF OVER NM/CO. THIS SHORTWAVE MAY BRING SOME
INTERESTING WEATHER LATER THIS WEEK DEPENDING ON HOW IT INTERACTS
WITH OTHER NRN STREAM ENERGY DIVING INTO THE TROF. WITH THE
SHORTWAVE LIFTING INTO NRN ONTARIO...SFC LOW PRES WAS TRACKING N
ACROSS WRN LAKE SUPERIOR. OCCLUDED FRONT WAS SWEEPING INTO WRN UPPER
MI WHILE SFC WARM FRONT IS STILL HELD UP S OF UPPER MI.
FORTUNATELY...LITTLE PCPN HAS FALLEN SINCE SHRA MOVED THRU THE FCST
AREA YESTERDAY MORNING/EARLY AFTN. THIS WILL HELP EASE RISES ON
RIVERS THAT HAVE HIGH FLOWS.
AS OCCLUDED FRONT MARCHES ACROSS THE AREA THIS MORNING/EARLY AFTN...
WILL MAINTAIN A SHRA CHC ALONG/AHEAD OF IT. THERE MAY YET BE SOME
THUNDER OVER THE ERN FCST AREA...BUT POTENTIAL LOOKS LIMITED WITH
LITTLE INSTABILITY. MEANWHILE...FOG...LOCALLY DENSE...WILL LIFT
QUICKLY WITH FROPA. OTHER ITEM OF NOTE TODAY IS THAT HEALTHY CAA
WILL AID GUSTY WINDS...ESPECIALLY ACROSS THE KEWEENAW UNDER
FAVORABLE WESTERLY WIND DIRECTION. GUSTS SHOULD BE UP TO AROUND 40KT
AT TIMES THERE.
DRY WEATHER WILL FOLLOW FOR TONIGHT UNDER DRY AIR MASS. LOWS WILL
FALL INTO THE 30S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 450 AM EDT TUE MAY 13 2014
DEEP TROUGHING IN PLACE ON WEDNESDAY AND THIS MAY ONLY DEEPEN FURTHER
BY LATE THIS WEEK AS AN UPPER LOW SLIDES ACROSS THE GREAT LAKES.
UPPER LOW WILL ONLY SLOWLY EXIT THE UPPER GREAT LAKES THIS WEEKEND.
NOT A LOT OF PRECIPITATION WITH THE EXPECTED PATTERN /THOUGH FRIDAY
IS STILL UNCERTAIN/...BUT IT WILL REMAIN UNSETTLED AND COOL INTO AT
LEAST FIRST PART OF WEEKEND. AND STILL CANNOT COUNT OUT POTENTIAL
FOR ACCUMULATING SNOW AROUND FRIDAY THOUGH THE MODEL LEADING THE
CHARGE ON THAT IDEA THE LAST SEVERAL DAYS...THE ECMWF...HAS BACKED
AWAY FROM THAT IDEA WITH MOST RECENT MODEL RUN...AS HAS THE GEM-NH
AND THE UKMET WHICH WAS TRACKING ALONG WITH THE ECMWF FOR A WHILE
NOW. ONLY TIME WILL TELL IF THIS IS A TREND OR A TEMPORARY SHIFT.
WEDNESDAY STILL APPEARS GENERALLY QUIET. SFC LOW WILL BE OVER
NORTHERN ONTARIO WITH GRADIENT WESTERLY FLOW OVER LK SUPERIOR/UPR
MICHIGAN. GRADIENT WEAKENS ENOUGH IN THE AFTN TO RESULT IN LAKE
BREEZES. FORCING WEAKER THAN IT LOOKED 24 HR AGO AND MOISTURE RATHER
PALTRY. EVEN THOUGH THERE MAY BE BUILD UP OF HIGHER BASED CU...NOT
EXPECTING ANY SHRA IN LAKE BREEZE CONVERGENCE AREAS OF CNTRL UPR
MICHIGAN. DWPTS START DAY AROUND 30F AND MIXED LAYER DWPNT OUTPUT
POINTED TO AROUND 20 FOR INTERIOR WEST BY MID AFTN. PRETTY FEASIBLE
GIVEN THE DEPTH OF MIXING. FOR NOW DROPPED DWPNTS INTO LOW-MID 20S
WHICH RESULTS IN RH VALUES AROUND 30 PCT. FIRE WX ISSUES WILL BE
MITIGATED BY RECENT RAINFALL AND SINCE WINDS SHOULD REMAIN MAINLY
BELOW 15 MPH.
WEDNESDAY NIGHT FEATURES CONTINUED QUIET WEATHER PATTERN WITH INCREASING
NORTH GRADIENT FLOW AS HIGH PRESSURE BUILDS OVER MANITOBA/ONTARIO AND
LOW PRESSURE WAVE DEEPENS OVER OHIO VALLEY AND BEGINS TO LIFT NORTH
TO THE CENTRAL GREAT LAKES REGION. MID-HIGH CLOUDS INCREASE WHICH
WILL KEEP MIN TEMPS ABOVE FREEZING MAJORITY OF CWA.
THURSDAY INTO FRIDAY...SHORTWAVE ROUNDS BASE OF PRIMARY TROUGH ALOFT
WHILE SECONDARY JET STREAK DIGS ACROSS THE ROCKIES INTO THE WESTERN
SIDE OF THE UPPER LEVEL TROUGH. RESULT IS TROUGH ALOFT BECOMING
NEGATIVE TILTED THEN CLOSING OFF BY FRIDAY. STRONGEST SHORTWAVE
WITHIN THE TROUGH LIFTS NORTHWARD. IT IS THIS SHORTWAVE AND
ASSOCIATED SFC LOW THAT HOLDS THE KEY FOR THE THURSDAY NIGHT AND
FRIDAY FORECAST. RECENT RUNS OF THE ECMWF WERE THE MOST WRAPPED UP
AND FARTHER WEST WITH THIS WAVE AND ASSOCIATED SFC LOW. GFS MOSTLY
HAS STAYED PROGRESSIVE AND FARTHER EAST WITH THE LOW...LIFTING IT
NORTHWARD OVER THE LOWER LAKES INSTEAD OF THE CENTRAL GREAT LAKES.
LATEST ECMWF/UKMET/GEM-NH GOING THAT WAY TOO. SEEMS THAT ECMWF HAS
MORE SHORTWAVE ENERGY AHEAD OF THE TROUGH THAN WAS THERE PERVIOUSLY.
THIS RESULTS IN UPPER TROUGH STAYING MORE OPEN/POSITIVELY TILTED
WHICH KEEPS THAT MAIN SHORTWAVE JUST A BIT FARTHER EAST. AT THE SAME
TIME...ECMWF ENSEMBLE MEAN AND A FAIR AMOUNT OF ENSEMBLES FROM THE
GEM STILL CONTINUE TO SUPPORT POTENTIAL FOR FARTHER WEST SFC LOW...
SO THAT IDEA MAY NOT BE DONE JUST YET.
PRIMARY CHANGE TO THE GOING FORECAST WAS TO GO BACK TO RAIN/SNOW
SHOWERS IDEA INSTEAD OF WIDESPREAD RAIN/SNOW...BOOSTED BY DAYTIME
HEATING DUE TO INSTABILITY ALOFT WITH THE UPPER TROUGH. STILL KEPT
TEMPS CHILLY ON FRIDAY AS THERE SHOULD BE BKN-OVC SKIES WITH NORTH OR
NORTHEAST WINDS OFF LK SUPERIOR...EVEN WITHOUT A STRONGER SYSTEM.
INITIAL PLAN WAS TO PUT A MENTION OF ACCUMULATING SNOW IN THE MORNING
HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS...BUT SINCE THE MODEL
THAT WAS SHOWING THIS MOST PERSISTENTLY BACKED AWAY...WILL NOT PUT
THAT MENTION IN THERE AFTER ALL. PROBABLY NOT TOO MUCH OF A STRETCH
TO SAY THAT WILL BE FINE WITH MOST PEOPLE THAT ARE TRYING TO PUT THIS
LONG COLD WINTER...AND EARLY SPRING...BEHIND THEM.
TROUGHING GRADUALLY PULLS AWAY DURING THE WEEKEND...BUT COULD STILL
SEE POTENTIAL FOR SOME LINGERING RAIN/SNOW SHOWERS ON SATURDAY WITH
FAIR AMOUNTS OF CLOUDS. LOOKS LIKE WE WILL BE IN THE CLEAR FOR
SUNDAY AND PROBABLY MONDAY AS WELL...WITH THE RETURN OF WARMER
TEMPERATURES...ALBEIT STILL BELOW NORMAL. READINGS MAY REACH MID TO
UPR 60S INLAND WEST WHILE MOST OTHER AREAS ARE IN THE 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1208 AM EDT TUE MAY 13 2014
ABUNDANT LOW LEVEL MOISTURE WILL CONTINUE IFR TO LIFR CONDITIONS
INTO THE OVERNIGHT HRS WITH ONLY ISOLD TO SCT -SHRA EXPECTED.
CONDITIONS WILL IMPROVE TO MVFR TUE MORNING WITH LOW LEVEL DRYING IN
THE WAKE OF A COLD FRONT AND TO VFR BY EARLY TO MID TUE AFTERNOON.
WEST WINDS WILL ALSO BECOME GUSTY...ESPECIALLY AT CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT TUE MAY 13 2014
LOW PRESSURE OVER WESTERN LK SUPERIOR WILL MOVE NORTHWARD TOWARD
HUDSON BAY TONIGHT INTO WEDNESDAY. A COLD FRONT CROSSES THE REGION
THIS MORNING SHIFTING WINDS FROM EASTERLY TO WESTERLY. WEST WINDS BY
AFTERNOON COULD REACH 30 KTS OVER PORTIONS WESTERN AND NORTH CENTRAL
LAKE SUPERIOR. THESE GUSTY WINDS WILL DIMINISH BELOW 25 KTS LATE
TONIGHT INTO WEDNESDAY MORNING. WINDS FOR THE REST OF THE WEEK WILL
MAINLY BE BLO 20 KTS. THERE DOES REMAIN SOME POTENTIAL THAT
NORTHERLY WINDS ON FRIDAY MAY REACH 30 KTS DEPENDING ON THE TRACK
AND STRENGTH OF A LOW PRESSURE SYSTEM LIFTING ACROSS THE GREAT LAKES.
&&
.HYDROLOGY...
ISSUED AT 450 AM EDT TUE MAY 13 2014
TOTAL RAINFALL AMOUNTS FROM THIS SYSTEM ENDED UP LESS THAN EXPECTED
WHICH IS RESULTING IN LESSER OVERALL RISE ON RIVERS THAN COULD HAVE
OCCURRED. ADDITIONAL RAINFALL THE NEXT COUPLE DAYS WILL BE MINIMAL.
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION...POSSIBLY IN THE FORM
OF RAIN AND SNOW...COULD ARRIVE THURSDAY NIGHT INTO FRIDAY.
HOWEVER...THE LATEST DATA IS NOT AS STRONG WITH THIS SYSTEM WHICH
RESULTS IN SCATTERED RAIN AND SNOW SHOWERS WITH ONLY LIGHT TOTAL
LIQUID EQUIVALENT PRECIPITATION. NO CHANGES HAVE BEEN MADE TO FLOOD
WARNINGS FOR THE STURGEON RIVER NEAR CHASSELL AND FOR THE MICHIGAMME
RIVER NEAR REPUBLIC...WITCH LAKE...AND TO THE EAST OF CRYSTAL FALLS
JUST DOWNSTREAM FROM WAY DAM AND HEMLOCK FALLS. SINCE NOT AS MUCH
RAIN OCCURRED OVER STURGEON RIVER BASIN IN BARAGA COUNTY THE LAST
SHIFT COORDINATED WITH THE NORTH CENTRAL RIVER FORECAST CENTER NEAR
MINNEAPOLIS AND REPLACED THE WARNING FOR THE STURGEON RIVER NEAR
ALSTON WITH AN ADVISORY.
DUE TO THE RAINFALL THAT DID OCCUR AND ONGOING SNOWMELT OVER THE
HIGHER TERRAIN OF MAINLY NORTHWEST AND NORTH CENTRAL UPPER
MICHIGAN...RIVER FLOWS WILL LIKELY REMAIN HIGH THROUGH THE REST OF
THE WEEK. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD
CONTINUE TO MONITOR THE LATEST RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR LMZ248-250.
DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
454 AM EDT TUE MAY 13 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 420 PM EDT MON MAY 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A DEEP MID LEVEL TROUGH FROM
WRN MANITOBA INTO THE SRN ROCKIES RESULTING IN SW FLOW FROM THE SRN
PLAINS INTO THE WRN GREAT LAKES. AT THE SFC... LOW PRES WAS LOCATED
OVER WRN WI WITH A COLD FRONT TO THE SE THROUGH CNTRL IA AND A WARM
FRONT INTO NRN WI. RADARS INDICATED THERE WAS A GAP IN THE PCPN OVER
NRN WI AND UPPER MI AS ONE MCS SLIDES TO THE E INTO WRN LOWER MI AND
ANOTHER LINE OF CONVECTION STRETCHED TO THE SW FROM ERN IA. WITH
ABUNDANT LOW LEVEL MOISTURE OVER THE AREA...AREAS OF FOG HAD
DEVELOPED ESPECIALLY IN AREAS WITH UPSLOPE ERLY FLOW.
TONIGHT...AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR
TONIGHT...THE WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS
POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER
MI. SHRA/TSRA ARE EXPECTED TO DEVELOP BUT THE GREATEST COVERAGE IS
EXPECTED FROM WI INTO FAR SRN UPPER MI...CLOSER TO THE HIGHER
INSTABILITY AND MORE FAVORABLE LOW LEVEL INFLOW. WITH ELEVATED CAPE
UP AROUND 1000J/KG AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS
WILL HAVE THE POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR
POSSIBLE...MAINLY OVER FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT.
THE MAIN THREAT SHOULD BE HAIL...BUT WITH PWATS NEAR 1.5 INCH
...HEAVY RAINFALL WILL ALSO BE POSSIBLE. ADDITIONAL SHRA/TSRA MAY
ALSO DEVELOP LATE TONIGHT ALONG THE COLD FRONT AS IT MOVES INTO THE
W HALF BTWN 06Z-12Z.
TUE...SHRA/TSRA WILL BE LIKELY IN THE MORNING OVER THE EAST HALF AS
THE COLD FRONT MOVES THROUGH THE AREA. OTHERWISE...STRONG DRYING
WILL MOVE INTO THE REST OF THE CWA. TEMPERATURES MAY CLIMB TO AROUND
60 BEFORE CAA STRENGTHENS IN THE AFTERNOON. GUSTY WEST WINDS WILL
ALSO DEVELOP ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE KEWEENAW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 450 AM EDT TUE MAY 13 2014
DEEP TROUGHING IN PLACE ON WEDNESDAY AND THIS MAY ONLY DEEPEN FURTHER
BY LATE THIS WEEK AS AN UPPER LOW SLIDES ACROSS THE GREAT LAKES.
UPPER LOW WILL ONLY SLOWLY EXIT THE UPPER GREAT LAKES THIS WEEKEND.
NOT A LOT OF PRECIPITATION WITH THE EXPECTED PATTERN /THOUGH FRIDAY
IS STILL UNCERTAIN/...BUT IT WILL REMAIN UNSETTLED AND COOL INTO AT
LEAST FIRST PART OF WEEKEND. AND STILL CANNOT COUNT OUT POTENTIAL
FOR ACCUMULATING SNOW AROUND FRIDAY THOUGH THE MODEL LEADING THE
CHARGE ON THAT IDEA THE LAST SEVERAL DAYS...THE ECMWF...HAS BACKED
AWAY FROM THAT IDEA WITH MOST RECENT MODEL RUN...AS HAS THE GEM-NH
AND THE UKMET WHICH WAS TRACKING ALONG WITH THE ECMWF FOR A WHILE
NOW. ONLY TIME WILL TELL IF THIS IS A TREND OR A TEMPORARY SHIFT.
WEDNESDAY STILL APPEARS GENERALLY QUIET. SFC LOW WILL BE OVER
NORTHERN ONTARIO WITH GRADIENT WESTERLY FLOW OVER LK SUPERIOR/UPR
MICHIGAN. GRADIENT WEAKENS ENOUGH IN THE AFTN TO RESULT IN LAKE
BREEZES. FORCING WEAKER THAN IT LOOKED 24 HR AGO AND MOISTURE RATHER
PALTRY. EVEN THOUGH THERE MAY BE BUILD UP OF HIGHER BASED CU...NOT
EXPECTING ANY SHRA IN LAKE BREEZE CONVERGENCE AREAS OF CNTRL UPR
MICHIGAN. DWPTS START DAY AROUND 30F AND MIXED LAYER DWPNT OUTPUT
POINTED TO AROUND 20 FOR INTERIOR WEST BY MID AFTN. PRETTY FEASIBLE
GIVEN THE DEPTH OF MIXING. FOR NOW DROPPED DWPNTS INTO LOW-MID 20S
WHICH RESULTS IN RH VALUES AROUND 30 PCT. FIRE WX ISSUES WILL BE
MITIGATED BY RECENT RAINFALL AND SINCE WINDS SHOULD REMAIN MAINLY
BELOW 15 MPH.
WEDNESDAY NIGHT FEATURES CONTINUED QUIET WEATHER PATTERN WITH INCREASING
NORTH GRADIENT FLOW AS HIGH PRESSURE BUILDS OVER MANITOBA/ONTARIO AND
LOW PRESSURE WAVE DEEPENS OVER OHIO VALLEY AND BEGINS TO LIFT NORTH
TO THE CENTRAL GREAT LAKES REGION. MID-HIGH CLOUDS INCREASE WHICH
WILL KEEP MIN TEMPS ABOVE FREEZING MAJORITY OF CWA.
THURSDAY INTO FRIDAY...SHORTWAVE ROUNDS BASE OF PRIMARY TROUGH ALOFT
WHILE SECONDARY JET STREAK DIGS ACROSS THE ROCKIES INTO THE WESTERN
SIDE OF THE UPPER LEVEL TROUGH. RESULT IS TROUGH ALOFT BECOMING
NEGATIVE TILTED THEN CLOSING OFF BY FRIDAY. STRONGEST SHORTWAVE
WITHIN THE TROUGH LIFTS NORTHWARD. IT IS THIS SHORTWAVE AND
ASSOCIATED SFC LOW THAT HOLDS THE KEY FOR THE THURSDAY NIGHT AND
FRIDAY FORECAST. RECENT RUNS OF THE ECMWF WERE THE MOST WRAPPED UP
AND FARTHER WEST WITH THIS WAVE AND ASSOCIATED SFC LOW. GFS MOSTLY
HAS STAYED PROGRESSIVE AND FARTHER EAST WITH THE LOW...LIFTING IT
NORTHWARD OVER THE LOWER LAKES INSTEAD OF THE CENTRAL GREAT LAKES.
LATEST ECMWF/UKMET/GEM-NH GOING THAT WAY TOO. SEEMS THAT ECMWF HAS
MORE SHORTWAVE ENERGY AHEAD OF THE TROUGH THAN WAS THERE PERVIOUSLY.
THIS RESULTS IN UPPER TROUGH STAYING MORE OPEN/POSITIVELY TILTED
WHICH KEEPS THAT MAIN SHORTWAVE JUST A BIT FARTHER EAST. AT THE SAME
TIME...ECMWF ENSEMBLE MEAN AND A FAIR AMOUNT OF ENSEMBLES FROM THE
GEM STILL CONTINUE TO SUPPORT POTENTIAL FOR FARTHER WEST SFC LOW...
SO THAT IDEA MAY NOT BE DONE JUST YET.
PRIMARY CHANGE TO THE GOING FORECAST WAS TO GO BACK TO RAIN/SNOW
SHOWERS IDEA INSTEAD OF WIDESPREAD RAIN/SNOW...BOOSTED BY DAYTIME
HEATING DUE TO INSTABILITY ALOFT WITH THE UPPER TROUGH. STILL KEPT
TEMPS CHILLY ON FRIDAY AS THERE SHOULD BE BKN-OVC SKIES WITH NORTH OR
NORTHEAST WINDS OFF LK SUPERIOR...EVEN WITHOUT A STRONGER SYSTEM.
INITIAL PLAN WAS TO PUT A MENTION OF ACCUMULATING SNOW IN THE MORNING
HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS...BUT SINCE THE MODEL
THAT WAS SHOWING THIS MOST PERSISTENTLY BACKED AWAY...WILL NOT PUT
THAT MENTION IN THERE AFTER ALL. PROBABLY NOT TOO MUCH OF A STRETCH
TO SAY THAT WILL BE FINE WITH MOST PEOPLE THAT ARE TRYING TO PUT THIS
LONG COLD WINTER...AND EARLY SPRING...BEHIND THEM.
TROUGHING GRADUALLY PULLS AWAY DURING THE WEEKEND...BUT COULD STILL
SEE POTENTIAL FOR SOME LINGERING RAIN/SNOW SHOWERS ON SATURDAY WITH
FAIR AMOUNTS OF CLOUDS. LOOKS LIKE WE WILL BE IN THE CLEAR FOR
SUNDAY AND PROBABLY MONDAY AS WELL...WITH THE RETURN OF WARMER
TEMPERATURES...ALBEIT STILL BELOW NORMAL. READINGS MAY REACH MID TO
UPR 60S INLAND WEST WHILE MOST OTHER AREAS ARE IN THE 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1208 AM EDT TUE MAY 13 2014
ABUNDANT LOW LEVEL MOISTURE WILL CONTINUE IFR TO LIFR CONDITIONS
INTO THE OVERNIGHT HRS WITH ONLY ISOLD TO SCT -SHRA EXPECTED.
CONDITIONS WILL IMPROVE TO MVFR TUE MORNING WITH LOW LEVEL DRYING IN
THE WAKE OF A COLD FRONT AND TO VFR BY EARLY TO MID TUE AFTERNOON.
WEST WINDS WILL ALSO BECOME GUSTY...ESPECIALLY AT CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT TUE MAY 13 2014
LOW PRESSURE OVER WESTERN LK SUPERIOR WILL MOVE NORTHWARD TOWARD
HUDSON BAY TONIGHT INTO WEDNESDAY. A COLD FRONT CROSSES THE REGION
THIS MORNING SHIFTING WINDS FROM EASTERLY TO WESTERLY. WEST WINDS BY
AFTERNOON COULD REACH 30 KTS OVER PORTIONS WESTERN AND NORTH CENTRAL
LAKE SUPERIOR. THESE GUSTY WINDS WILL DIMINISH BELOW 25 KTS LATE
TONIGHT INTO WEDNESDAY MORNING. WINDS FOR THE REST OF THE WEEK WILL
MAINLY BE BLO 20 KTS. THERE DOES REMAIN SOME POTENTIAL THAT
NORTHERLY WINDS ON FRIDAY MAY REACH 30 KTS DEPENDING ON THE TRACK
AND STRENGTH OF A LOW PRESSURE SYSTEM LIFTING ACROSS THE GREAT LAKES.
&&
.HYDROLOGY...
ISSUED AT 450 AM EDT TUE MAY 13 2014
TOTAL RAINFALL AMOUNTS FROM THIS SYSTEM ENDED UP LESS THAN EXPECTED
WHICH IS RESULTING IN LESSER OVERALL RISE ON RIVERS THAN COULD HAVE
OCCURRED. ADDITIONAL RAINFALL THE NEXT COUPLE DAYS WILL BE MINIMAL.
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION...POSSIBLY IN THE FORM
OF RAIN AND SNOW...COULD ARRIVE THURSDAY NIGHT INTO FRIDAY.
HOWEVER...THE LATEST DATA IS NOT AS STRONG WITH THIS SYSTEM WHICH
RESULTS IN SCATTERED RAIN AND SNOW SHOWERS WITH ONLY LIGHT TOTAL
LIQUID EQUIVALENT PRECIPITATION. NO CHANGES HAVE BEEN MADE TO FLOOD
WARNINGS FOR THE STURGEON RIVER NEAR CHASSELL AND FOR THE MICHIGAMME
RIVER NEAR REPUBLIC...WITCH LAKE...AND TO THE EAST OF CRYSTAL FALLS
JUST DOWNSTREAM FROM WAY DAM AND HEMLOCK FALLS. SINCE NOT AS MUCH
RAIN OCCURRED OVER STURGEON RIVER BASIN IN BARAGA COUNTY THE LAST
SHIFT COORDINATED WITH THE NORTH CENTRAL RIVER FORECAST CENTER NEAR
MINNEAPOLIS AND REPLACED THE WARNING FOR THE STURGEON RIVER NEAR
ALSTON WITH AN ADVISORY.
DUE TO THE RAINFALL THAT DID OCCUR AND ONGOING SNOWMELT OVER THE
HIGHER TERRAIN OF MAINLY NORTHWEST AND NORTH CENTRAL UPPER
MICHIGAN...RIVER FLOWS WILL LIKELY REMAIN HIGH THROUGH THE REST OF
THE WEEK. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD
CONTINUE TO MONITOR THE LATEST RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR LMZ248-250.
DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1209 AM EDT TUE MAY 13 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 420 PM EDT MON MAY 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A DEEP MID LEVEL TROUGH FROM
WRN MANITOBA INTO THE SRN ROCKIES RESULTING IN SW FLOW FROM THE SRN
PLAINS INTO THE WRN GREAT LAKES. AT THE SFC... LOW PRES WAS LOCATED
OVER WRN WI WITH A COLD FRONT TO THE SE THROUGH CNTRL IA AND A WARM
FRONT INTO NRN WI. RADARS INDICATED THERE WAS A GAP IN THE PCPN OVER
NRN WI AND UPPER MI AS ONE MCS SLIDES TO THE E INTO WRN LOWER MI AND
ANOTHER LINE OF CONVECTION STRETCHED TO THE SW FROM ERN IA. WITH
ABUNDANT LOW LEVEL MOISTURE OVER THE AREA...AREAS OF FOG HAD
DEVELOPED ESPECIALLY IN AREAS WITH UPSLOPE ERLY FLOW.
TONIGHT...AS SFC LOW PRES LIFTS FROM WRN WI ACROSS WRN LAKE SUPERIOR
TONIGHT...THE WARM FRONT WILL ATTEMPT TO MOVE INTO UPPER MI. AT THIS
POINT...IT APPEARS THE WARM FRONT MAY JUST SLIP INTO FAR SRN UPPER
MI. SHRA/TSRA ARE EXPECTED TO DEVELOP BUT THE GREATEST COVERAGE IS
EXPECTED FROM WI INTO FAR SRN UPPER MI...CLOSER TO THE HIGHER
INSTABILITY AND MORE FAVORABLE LOW LEVEL INFLOW. WITH ELEVATED CAPE
UP AROUND 1000J/KG AND DEEP LAYER SHEAR AROUND 30KT OR SO...STORMS
WILL HAVE THE POTENTIAL TO BECOME ORGANIZED WITH ISOLD SVR
POSSIBLE...MAINLY OVER FAR SCNTRL UPPER MI...CLOSER TO WARM FRONT.
THE MAIN THREAT SHOULD BE HAIL...BUT WITH PWATS NEAR 1.5 INCH
...HEAVY RAINFALL WILL ALSO BE POSSIBLE. ADDITIONAL SHRA/TSRA MAY
ALSO DEVELOP LATE TONIGHT ALONG THE COLD FRONT AS IT MOVES INTO THE
W HALF BTWN 06Z-12Z.
TUE...SHRA/TSRA WILL BE LIKELY IN THE MORNING OVER THE EAST HALF AS
THE COLD FRONT MOVES THROUGH THE AREA. OTHERWISE...STRONG DRYING
WILL MOVE INTO THE REST OF THE CWA. TEMPERATURES MAY CLIMB TO AROUND
60 BEFORE CAA STRENGTHENS IN THE AFTERNOON. GUSTY WEST WINDS WILL
ALSO DEVELOP ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE KEWEENAW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 401 PM EDT MON MAY 12 2014
NAM SHOWS A CLOSED 500 MB LOW OVER EASTERN MANITOBA 00Z WED WITH A
TROUGH OVER THE UPPER GREAT LAKES AND A RIDGE ON THE WEST COAST.
THIS TROUGH DOES NOT MOVE MUCH THROUGH THU. NAM SHOWS SOME 850-500
MB Q-VECTOR CONVERGENCE THROUGH THE PERIOD WITH THE STRONGEST
CONVERGENCE OVER THE ERN CWA. MOISTURE STAYS LIMITED UNTIL THU AND
WILL REMAIN DRY THROUGH WED NIGHT BEFORE MOISTURE MOVES IN.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THIS FORECAST PERIOD
AND DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE UPPER
GREAT LAKES 12Z FRI WITH A RIDGE OVER THE WESTERN U.S. PATTERN
CHANGES LITTLE 12Z SAT WITH THE RIDGE MOVING INTO THE PLAINS ON SUN
AND THE TROUGH MOVING INTO THE LOWER GREAT LAKES. THE RIDGE MOVES
INTO THE MISSISSIPPI RIVER VALLEY ON MON. TEMPERATURES LOOK TO STAY
BELOW NORMAL THIS FORECAST PERIOD WITH A SLOW MODIFICATION TREND AND
LOOKS WET THIS FORECAST PERIOD UNTIL SUN AND SUN NIGHT WHEN THE
UPPER RIDGE MOVES IN. OTHERWISE...PCPN CHANCES WILL STAY LOW
THROUGH THE PERIOD. HAVING SOME SNOW IN DURING THE LATE NIGHT AND
EARLY MORNING HOURS THU NIGHT THROUGH SAT MORNING STILL LOOKS GOOD
AS WELL WITH COLD ENOUGH TEMPERATURES TO NOT COMPLETELY RULE THIS
POSSIBILITY OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1208 AM EDT TUE MAY 13 2014
ABUNDANT LOW LEVEL MOISTURE WILL CONTINUE IFR TO LIFR CONDITIONS
INTO THE OVERNIGHT HRS WITH ONLY ISOLD TO SCT -SHRA EXPECTED.
CONDITIONS WILL IMPROVE TO MVFR TUE MORNING WITH LOW LEVEL DRYING IN
THE WAKE OF A COLD FRONT AND TO VFR BY EARLY TO MID TUE AFTERNOON.
WEST WINDS WILL ALSO BECOME GUSTY...ESPECIALLY AT CMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EDT MON MAY 12 2014
NE GALES ACROSS WRN LAKE SUPERIOR LATE THIS AFTERNOON INTO THIS
EVENING WILL DIMINISH OVERNIGHT AS LOW PRES LIFTS TOWARD THE AREA
AND THE PRES GRADIENT WEAKENS. ONCE THE LOW MOVES NORTH OF THE LAKE
TUE MORNING...STRONG WEST WINDS WILL DEVELOP. THE GUSTY WINDS WILL
SLOWLY DIMINISHING BELOW 25 KTS BY WEDNESDAY MORNING. WINDS FOR THE REST
OF THE WEEK WILL MAINLY BE BLO 20 KTS. HOWEVER...A LOW PRESSURE
SYSTEM COULD IMPACT THE REGION LATE THIS WEEK WITH WINDS OVER 25 KTS
THURSDAY INTO FRIDAY. UNCERTAINTY IS HIGH WITH THAT SYSTEM
THOUGH...SO CURRENT FORECAST WILL ONLY CALL FOR NORTHWEST TO 20 KTS
AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 401 PM EDT MON MAY 12 2014
RAINFALL AMOUNTS FOR THIS WHOLE RAIN EVENT THROUGH TUE AFTERNOON MAY
EXCEED ONE TO ONE AND A HALF INCHES OVER PORTIONS OF WESTERN UPR
MICHIGAN. RAIN CHANCES DIMINISH FROM WEST TO EAST ON TUESDAY AS A
FRONTAL BOUNDARY EXITS THE REGION. RAINFALL WILL ONLY ADD TO THE
ONGOING SNOWMELT AND ALREADY HIGH FLOWS ON AREA RIVERS AND STREAMS.
THE MICHIGAMME RIVER NEAR REPUBLIC AND WITCH LAKE...THE STURGEON
RIVER AT CHASSELL AND ALSTON AND THE MICHIGAMME RIVER DOWNSTREAM OF
THE WAY DAM TO THE EAST OF CRYSTAL FALLS ARE UNDER FLOOD WARNINGS.
GIVEN THE RAINFALL THAT WILL OCCUR THE NEXT 24-36 HOURS...RIVER
LEVELS WILL KEEP RISING AND ADJUSTMENTS WILL LIKELY BE NEEDED BASED
ON LATEST TRENDS. ALL THIS WATER DUE TO THE SNOWMELT AND THE
RAINFALL WILL TAKE A WHILE TO WORK THROUGH THE RIVERS...SO IT IS
QUITE LIKELY THAT HIGHER RIVER FLOWS AND THE ASSOCIATED ADVISORIES
AND WARNINGS ON AREA RIVERS WILL CONTINUE THROUGH LATE THIS
WEEK...IF NOT INTO THIS WEEKEND. THOSE LIVING NEAR
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR THE LATEST
RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR LMZ221-
248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...07
AVIATION...VOSS
MARINE...JLB
HYDROLOGY...07
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
450 AM EDT TUE MAY 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH
WEDNESDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. OUR PATTERN WILL
REMAIN UNSETTLED INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
430 AM UPDATE...
COMPLEX OF STORMS DOVE THROUGH SOUTHWEST PA THE LAST SEVERAL
HOURS...AND THEN WEAKENED. HOWEVER...NEW CONVECTION HAS FIRED AT
LEADING EDGE OF 850MB JET...ALSO COINCIDING WITH A WEAK WAVE
ALOFT...EXTENDING FROM THE ONTARIO PENINSULA TO THE WESTERN TIP OF
NY AND SOME OF WESTERN PA. MEANWHILE...JUST A FEW SHOWERS HAVE RESULTED
FROM A WEAK VORTICITY MAXIMUM NOW TRAVERSING THE NY THRUWAY
CORRIDOR...WHICH IS RUNNING INTO PROGRESSIVELY MORE STABLE AIR AND
THUS NOT MUCH OF A PLAYER IN OUR WEATHER.
EARLIER RUNS OF THE WRF-ARW...NAM...GEM...AND NMM BROUGHT NOCTURNAL
CONVECTION WITH WAVE INTO THE TWIN TIERS YET INITIALIZED WITH THE
EARLIER SW PA COMPLEX TOTALLY MISSING. THUS I SIDED HRRR AND RUC13
SOLUTIONS WHICH HAD THE SW PA COMPLEX AND AS EXPECTED KEPT THINGS
PRETTY QUIET THROUGH MOST OF THE OVERNIGHT HOURS. THE NEW
CONVECTION NOW IN WESTERN NY/PA IS AT LEADING EDGE OF 850MB
JET...BUT MODELS SHOW THAT THE JET WILL WEAKEN CONSIDERABLY THE
NEXT FEW HOURS SO I ANTICIPATE THE ASSOCIATED CONVECTION TO
DIMINISH WHILE SKIMMING SOME OF OUR SW ZONES EARLY THIS MORNING.
HIGH PRESSURE IS CURRENTLY SLIDING OUT OF QUEBEC TO MAINE/CANADIAN
MARITIME PROVINCES...INITIATING COOL AIR DAMMING DOWN THE
APPALACHIANS. SOUTHEAST LOW LEVEL FLOW WILL DEVELOP
TODAY...SETTING UP A SURFACE CONVERGENCE ZONE IN VICINITY OF
FINGER LAKES TO CENTRAL SOUTHERN TIER OF NY. I THUS HAVE PLACED
HIGH CHANCE POPS IN CENTRAL SOUTHERN TIER TO FINGER LAKES FOR LATE
MORNING TO AFTERNOON TODAY. MODEL SOUNDINGS THERE SHOW SUFFICIENT
INSTABILITY FOR THUNDER TO ACCOMPANY THOSE SHOWERS...AND
PRECIPITABLE WATER VALUES OF NEARLY AN INCH-AND-A-HALF.
HOWEVER...THE FARTHER EAST THAT ACTIVITY MANAGES TO PROCEED...THE
DEEPER INTO THE MORE STABLE SOUTHEAST FLOW /VIA COOL AIR DAMMING
ALONG EAST COAST/ IT WILL GET. THUS LOWER CHANCES FOR SHOWERS AND
ONLY SLIGHT CHANCE OF THUNDER AT MOST. I DO NOT EVEN INCLUDE
THUNDER MENTION IN WESTERN CATSKILLS TO POCONOS.
NOT QUITE AS WARM AS MONDAY...DUE TO CLOUD COVERAGE IN WEST AND
MARINE INFLUENCED LOW LEVEL FLOW IN EAST...YET STILL 70S FOR MOST OF
THE AREA. SOME LOWER ELEVATIONS IN TWIN TIERS TO FINGER LAKES
COULD EVEN STILL MANAGE 80 DEGREES.
UPPER RIDGE PASSES OVER THE REGION TONIGHT. THERE WILL BE
MARGINAL ELEVATED INSTABILITY ALOFT IN THE WESTERN ZONES...BUT
LACK OF FORCING MECHANISMS OTHER THAN WEAK WAVES TRYING TO RIDE
THROUGH THE RIDGE HAS ME HESITANT TO GO ANY HIGHER THAN SLIGHT TO
LOW CHANCE POPS. LOWS TONIGHT IN THE 50S TO LOW 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
445 AM UPDATE...
MAIN ADJUSTMENT WAS TO FURTHER DELAY THE HIGHEST RAIN CHANCES
ASSOCIATED WITH INCOMING COLD-OCCLUDED FRONTAL ZONE. THERE WILL
STILL BE SHOWERS AROUND...PARTICULARLY WEDNESDAY AS NORTHERN STREAM
SURFACE FRONT EDGES INTO THE AREA BEFORE SHIFTING BACK NORTH.
THERE WILL ALSO BE MARGINAL INSTABILITY SUPPORTING MENTION OF
THUNDER IN CENTRAL TO NORTHERN ZONES. HOWEVER...MUCH OF THE TIME
OVERALL WILL BE DRY...ESPECIALLY THURSDAY. THE SLOWER TIMING OF
INCOMING SYSTEM ALSO FORCED A WARMER ADJUSTMENT FOR HIGH
TEMPERATURES THURSDAY TO MAINLY 75-80 DEGREE RANGE...THANKS TO
WARM SECTOR FIRMLY REASSERTING ITSELF WELL AHEAD OF THE COLD
FRONT. RAIN CHANCES THEN INCREASE THURSDAY NIGHT AS THAT COLD
FRONT APPROACHES.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
350 AM UPDATE...
NO MAJOR CHANGES NEEDED THIS MORNING WITH ALL ATTENTION REMAINING
FOCUSED ON LATE WEEK RAIN EVENT. FCST MODELS NOW COMING INTO
BETTER AGREEMENT ON TIMING OF FROPA...WITH MOST SUGGESTING FEATURE
WILL PASS ACROSS THE REGION AFTER 12Z FRI. MAIN CONCERNS RIGHT NOW
APPEAR TO BE A POSSIBLE PERIOD OF HEAVY RAINFALL AS 850 U-WIND
SPEEDS OF 2-3 STANDARD DEVIATIONS ABOVE NORMAL PUMP AMPLE GULF OF
MEXICO AND WESTERN ATLANTIC MOISTURE NORTH TOWARDS OUR AREA. AS
IT STANDS RIGHT NOW...FEATURE LOOKS TO PASS QUICK ENOUGH TO
HOPEFULLY NEGATE ANY SIGNIFICANT HYDRO IMPACTS BUT LATER MODEL
RUNS WILL BE ABLE TO VERIFY THIS TREND. OVERALL CONVECTIVE
POTENTIAL LOOKS LIMITED AS THE HEAVIEST RAINS ARE EXPECTED IN A
POST FRONTAL (ANAFRONT-TYPE) AIRMASS WHERE INSTABILITY WILL BE LIMITED.
AFTER THIS FEATURE PASSES...EXPECT COOLER THAN NORMAL WEATHER INTO
THE UPCOMING WEEKEND AS SLOW MOVING UPPER LOW GRADUALLY ADVANCES
EAST INTO NEW ENGLAND AND NORTHERLY FLOW RETURNS TO THE AREA.
210 PM UPDATE...
EXTNDD PD STARTS OFF WITH H5 LOW BEGINNING TO CLOSE OFF IN THE WRN
GREAT LKS WITH FRONTAL BNDRY MEANDERING NR AREA THRU THE END OF THE
WEEK AND FIRST HALF OF THE WEEKEND. SVRL WVS OF LOPRES WL RIDE UP
ALONG BNDRY, WITH HEAVIEST RAIN LKLY THUR NGT AND FRI AHD OF CDFNT.
WITH BNDRY ON OUR DOORSTEP LATE THUR NGT/FRI MRNG EXPECT CHCS FOR
THUNDER AT ANY TIME TO START OFF THE LONG TERM. WL WORD IT AS CHC
TSTMS FOR THUR NGT WITH LKLY SHOWERS/THUNDER DRG THE DAY ON FRIDAY
WITH TIMING LKLY TO BE NAILED DOWN THE CLOSER WE GET TO THE END OF
THE WEEK. LATEST EURO IS FASTER THAN THE GFS/CMC ON PROGRESSION OF
FROPA WITH LATTER MODELS DELAYING ITS ARRIVAL UNTIL CLOSE TO 00Z SAT
WHILE EURO CLRS CWA BY 12Z FRIDAY.
UNSETTLED WX CONTS THRU THE EARLY PART OF THE WEEK AS ERN U.S. TROF
RMNS IN PLACE. LATEST GFS INDICATE H5 LOW CLOSING OFF AGAIN OVR THE
NORTHEAST U.S. ON MONDAY THUS WL KEEP CHC POPS IN AFT 12Z SATURDAY
WITH POTENTIAL COLD POOL ALOFT CAUSING INSTABILITY SHOWERS.
TEMPS THRU THE PD WL BE NR NORMAL TO SLIGHTLY BLO NORMAL UNDER
EXTENSIVE CLD CVR AND SHOWERY CONDS.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
CHALLENGING FCST EARLY THIS MORNING AS MUCH OF CENTRAL NY AND
NORTHEAST PA REMAINS POSITIONED BETWEEN TWO SEPARATE AREAS OF
RAINFALL. THE FIRST OF THESE IS NOW MOVING THROUGH WESTERN NY
WITH LGT SHWR ACTIVITY NOTED ACROSS THE CENTRAL LAKE ONTARIO LAKE
SHORE. THE SECOND REGION...IN THE FORM OF A WEAKLY ORGANIZED
MCS...NOW DIVING SOUTH ACROSS SOUTH-CENTRAL PA WITH REDEVELOPING
ACTIVITY NOTED TO THE NORTH ACROSS NORTHWESTERN PA. WITH DEWPOINTS
RESIDING IN THE MID TO UPPER 50S ACROSS MUCH OF THE AREA...PLENTY
OF LOW-LEVEL MOISTURE IS IN PLACE FOR RADIATIONAL FOG FORMATION
FOR VALLEY LOCATIONS THAT SEE TEMPORARY CLEARING. FOR NOW...HAVE
ELECTED TO OFFER AN IFR VSBY MENTION AT ELM AFTER 9Z AS INCREASED
SUBSIDENCE BEHIND THE CENTRAL PA MCS MAY LEAD TO SOME TEMPORARY
CLEARING. ELSEWHERE...VFR CONDITIONS FCST THROUGH THE EARLY
MORNING WITH A LGT SHWR MENTION ADDED FOR SYR AND RME BASED ON
CURRENT LAKE ONTARIO SHORELINE ACTIVITY.
HEADING INTO TODAY...FCST MODELS SHOW DEVELOPING CONVECTION ACROSS
THE CENTRAL FINGER LAKES AS LOW-LEVEL CONVERGENCE INCREASES ALONG
A DEVELOPING SFC TROUGH. FOR NOW...HAVE ADDED TEMPO MENTIONS AT
BOTH ELM AND ITH LATER THIS AFTERNOON AND WILL AFFORD LATER
SHIFTS THE OPPORTUNITY TO ADD THUNDER IF CONDITIONS DO IN FACT
BECOME UNSTABLE ENOUGH LATER TODAY. FURTHER EAST...DRIER AIR
ASSOCIATED WITH HIGH PRESSURE ACROSS NEW ENGLAND WILL LIKELY KEEP
THE BULK OF SHWR ACTIVITY WEST OF I-81.
LGT SOUTHERLY WINDS BETWEEN 5-10 KTS EXPECTED THROUGH THE PERIOD.
OUTLOOK...
WED THROUGH THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN SHOWERS AND
THUNDERSTORMS.
THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS
COLD FRONT STALLS NEAR AREA.
SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE
AFTERNOON.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...TAC
LONG TERM...CMG/PVN
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
402 AM EDT TUE MAY 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH
WEDNESDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. OUR PATTERN WILL
REMAIN UNSETTLED INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
145 AM UPDATE...
REGIONAL RADAR CONTINUES TO SHOW COMPLEX OF STORMS DIVING THROUGH
SOUTHWEST PA...WHILE JUST A FEW SHOWERS EXIST OVER LAKE ONTARIO TO
THE ROCHESTER AREA. THE NORTHERN SHOWERS ARE ASSOCIATED WITH A
WAVE WHICH IS MOVING THROUGH AS PREVIOUSLY ANTICIPATED...BUT IT
HAS A LOT LESS ACTIVITY PROBABLY DUE TO SUBSIDENCE AROUND THE SW
PA COMPLEX. WRF- ARW...NAM...GEM...AND NMM ALL BRING NOCTURNAL
CONVECTION WITH WAVE INTO THE TWIN TIERS YET HAVE INITIALIZED WITH
SW PA COMPLEX TOTALLY MISSING. I AM THUS SIDING HRRR AND RUC13
SOLUTIONS WHICH HAVE THE SW PA COMPLEX AND ALSO KEEP THINGS PRETTY
QUIET THROUGH THE REMAINDER OF EARLY MORNING. SOUTHERN LAKE HURON
MEANWHILE HAS NEW STORMS DEVELOPING WHICH WE WILL NEED TO KEEP AN
EYE ON...BUT I ANTICIPATE THAT PARTICULAR CLUSTER TO LIFT
NORTHEASTWARD. IT DOES PROVIDE A HINT TO WHAT MAY OCCUR LATER
TODAY HOWEVER. MORE ON THAT BELOW.
HIGH PRESSURE IS CURRENTLY SLIDING OUT OF QUEBEC TO MAINE/CANADIAN
MARITIME PROVINCES...INITIATING COOL AIR DAMMING DOWN THE
APPALACHIANS. SOUTHEAST LOW LEVEL FLOW WILL DEVELOP
TODAY...SETTING UP A SURFACE CONVERGENCE ZONE IN VICINITY OF
FINGER LAKES TO CENTRAL SOUTHERN TIER OF NY. TRAILING END OF WAVE
CURRENTLY FIRING CONVECTION IN SOUTHERN LAKE HURON...CONNECTING TO
THE ONTARIO PENINSULA TO NEAR ERIE PA...WILL LIFT NORTHEASTWARD
INTO CENTRAL SOUTHERN TIER JUST AS DIURNAL HEATING GETS GOING.
THIS COINCIDES WITH THE WEAK LOW LEVEL CONVERGENCE AS WELL. I THUS
HAVE PLACED HIGH CHANCE POPS IN CENTRAL SOUTHERN TIER TO FINGER
LAKES FOR LATE MORNING TO AFTERNOON TODAY. MODEL SOUNDINGS THERE
SHOW SUFFICIENT INSTABILITY FOR THUNDER TO ACCOMPANY THOSE
SHOWERS. HOWEVER...THE FARTHER EAST THAT ACTIVITY MANAGES TO
PROCEED...THE DEEPER INTO THE MORE STABLE SOUTHEAST FLOW /VIA COOL
AIR DAMMING ALONG EAST COAST/ IT WILL GET. THUS LOWER CHANCES FOR
SHOWERS AND ONLY SLIGHT CHANCE OF THUNDER AT MOST. I DO NOT EVEN
INCLUDE THUNDER MENTION IN WESTERN CATSKILLS TO POCONOS.
NOT QUITE AS WARM AS MONDAY...DUE TO CLOUD COVERAGE IN WEST AND
SOUTHEAST LOW LEVEL FLOW IN EAST...YET STILL 70S FOR MOST OF THE
AREA. LOWER ELEVATIONS IN TWIN TIERS TO FINGER LAKES COULD EVEN
MANAGE 80 DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
3 PM UPDATE...
INTO THE AREA TUE NGT TO WED NGT. DIURNAL HEATING WILL HELP
CONVECTION DURING THE AFTN. IN WARM SECTOR WED AND THU WITH
DECENT SFC INSTABILITY BUT ONLY WEAK FORCING.
AS THE UL TROF MOVES EAST IT WILL FINALLY KICK THE COLD FRONT
THROUGH DURING THE EXTENDED. THIS SHORT TERM SOME SOAKING RAINS
BUT MAJORITY OF TIME WILL BE DRY. INCREASING HUMIDITY WITH DEWPTS
RISING INTO U50S AND L60S. MILD TEMPS AND FOLLOWED GUIDANCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
350 AM UPDATE...
NO MAJOR CHANGES NEEDED THIS MORNING WITH ALL ATTENTION REMAINING
FOCUSED ON LATE WEEK RAIN EVENT. FCST MODELS NOW COMING INTO
BETTER AGREEMENT ON TIMING OF FROPA...WITH MOST SUGGESTING FEATURE
WILL PASS ACROSS THE REGION AFTER 12Z FRI. MAIN CONCERNS RIGHT NOW
APPEAR TO BE A POSSIBLE PERIOD OF HEAVY RAINFALL AS 850 U-WIND
SPEEDS OF 2-3 STANDARD DEVIATIONS ABOVE NORMAL PUMP AMPLE GULF OF
MEXICO AND WESTERN ATLANTIC MOISTURE NORTH TOWARDS OUR AREA. AS
IT STANDS RIGHT NOW...FEATURE LOOKS TO PASS QUICK ENOUGH TO
HOPEFULLY NEGATE ANY SIGNIFICANT HYDRO IMPACTS BUT LATER MODEL
RUNS WILL BE ABLE TO VERIFY THIS TREND. OVERALL CONVECTIVE
POTENTIAL LOOKS LIMITED AS THE HEAVIEST RAINS ARE EXPECTED IN A
POST FRONTAL (ANAFRONT-TYPE) AIRMASS WHERE INSTABILITY WILL BE LIMITED.
AFTER THIS FEATURE PASSES...EXPECT COOLER THAN NORMAL WEATHER INTO
THE UPCOMING WEEKEND AS SLOW MOVING UPPER LOW GRADUALLY ADVANCES
EAST INTO NEW ENGLAND AND NORTHERLY FLOW RETURNS TO THE AREA.
210 PM UPDATE...
EXTNDD PD STARTS OFF WITH H5 LOW BEGINNING TO CLOSE OFF IN THE WRN
GREAT LKS WITH FRONTAL BNDRY MEANDERING NR AREA THRU THE END OF THE
WEEK AND FIRST HALF OF THE WEEKEND. SVRL WVS OF LOPRES WL RIDE UP
ALONG BNDRY, WITH HEAVIEST RAIN LKLY THUR NGT AND FRI AHD OF CDFNT.
WITH BNDRY ON OUR DOORSTEP LATE THUR NGT/FRI MRNG EXPECT CHCS FOR
THUNDER AT ANY TIME TO START OFF THE LONG TERM. WL WORD IT AS CHC
TSTMS FOR THUR NGT WITH LKLY SHOWERS/THUNDER DRG THE DAY ON FRIDAY
WITH TIMING LKLY TO BE NAILED DOWN THE CLOSER WE GET TO THE END OF
THE WEEK. LATEST EURO IS FASTER THAN THE GFS/CMC ON PROGRESSION OF
FROPA WITH LATTER MODELS DELAYING ITS ARRIVAL UNTIL CLOSE TO 00Z SAT
WHILE EURO CLRS CWA BY 12Z FRIDAY.
UNSETTLED WX CONTS THRU THE EARLY PART OF THE WEEK AS ERN U.S. TROF
RMNS IN PLACE. LATEST GFS INDICATE H5 LOW CLOSING OFF AGAIN OVR THE
NORTHEAST U.S. ON MONDAY THUS WL KEEP CHC POPS IN AFT 12Z SATURDAY
WITH POTENTIAL COLD POOL ALOFT CAUSING INSTABILITY SHOWERS.
TEMPS THRU THE PD WL BE NR NORMAL TO SLIGHTLY BLO NORMAL UNDER
EXTENSIVE CLD CVR AND SHOWERY CONDS.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
CHALLENGING FCST EARLY THIS MORNING AS MUCH OF CENTRAL NY AND
NORTHEAST PA REMAINS POSITIONED BETWEEN TWO SEPARATE AREAS OF
RAINFALL. THE FIRST OF THESE IS NOW MOVING THROUGH WESTERN NY
WITH LGT SHWR ACTIVITY NOTED ACROSS THE CENTRAL LAKE ONTARIO LAKE
SHORE. THE SECOND REGION...IN THE FORM OF A WEAKLY ORGANIZED
MCS...NOW DIVING SOUTH ACROSS SOUTH-CENTRAL PA WITH REDEVELOPING
ACTIVITY NOTED TO THE NORTH ACROSS NORTHWESTERN PA. WITH DEWPOINTS
RESIDING IN THE MID TO UPPER 50S ACROSS MUCH OF THE AREA...PLENTY
OF LOW-LEVEL MOISTURE IS IN PLACE FOR RADIATIONAL FOG FORMATION
FOR VALLEY LOCATIONS THAT SEE TEMPORARY CLEARING. FOR NOW...HAVE
ELECTED TO OFFER AN IFR VSBY MENTION AT ELM AFTER 9Z AS INCREASED
SUBSIDENCE BEHIND THE CENTRAL PA MCS MAY LEAD TO SOME TEMPORARY
CLEARING. ELSEWHERE...VFR CONDITIONS FCST THROUGH THE EARLY
MORNING WITH A LGT SHWR MENTION ADDED FOR SYR AND RME BASED ON
CURRENT LAKE ONTARIO SHORELINE ACTIVITY.
HEADING INTO TODAY...FCST MODELS SHOW DEVELOPING CONVECTION ACROSS
THE CENTRAL FINGER LAKES AS LOW-LEVEL CONVERGENCE INCREASES ALONG
A DEVELOPING SFC TROUGH. FOR NOW...HAVE ADDED TEMPO MENTIONS AT
BOTH ELM AND ITH LATER THIS AFTERNOON AND WILL AFFORD LATER
SHIFTS THE OPPORTUNITY TO ADD THUNDER IF CONDITIONS DO IN FACT
BECOME UNSTABLE ENOUGH LATER TODAY. FURTHER EAST...DRIER AIR
ASSOCIATED WITH HIGH PRESSURE ACROSS NEW ENGLAND WILL LIKELY KEEP
THE BULK OF SHWR ACTIVITY WEST OF I-81.
LGT SOUTHERLY WINDS BETWEEN 5-10 KTS EXPECTED THROUGH THE PERIOD.
OUTLOOK...
WED THROUGH THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN SHOWERS AND
THUNDERSTORMS.
THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS
COLD FRONT STALLS NEAR AREA.
SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE
AFTERNOON.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...TAC
LONG TERM...CMG/PVN
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
214 AM EDT TUE MAY 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH
WEDNESDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. OUR PATTERN WILL
REMAIN UNSETTLED INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
145 AM UPDATE...
REGIONAL RADAR CONTINUES TO SHOW COMPLEX OF STORMS DIVING THROUGH
SOUTHWEST PA...WHILE JUST A FEW SHOWERS EXIST OVER LAKE ONTARIO TO
THE ROCHESTER AREA. THE NORTHERN SHOWERS ARE ASSOCIATED WITH A
WAVE WHICH IS MOVING THROUGH AS PREVIOUSLY ANTICIPATED...BUT IT
HAS A LOT LESS ACTIVITY PROBABLY DUE TO SUBSIDENCE AROUND THE SW
PA COMPLEX. WRF- ARW...NAM...GEM...AND NMM ALL BRING NOCTURNAL
CONVECTION WITH WAVE INTO THE TWIN TIERS YET HAVE INITIALIZED WITH
SW PA COMPLEX TOTALLY MISSING. I AM THUS SIDING HRRR AND RUC13
SOLUTIONS WHICH HAVE THE SW PA COMPLEX AND ALSO KEEP THINGS PRETTY
QUIET THROUGH THE REMAINDER OF EARLY MORNING. SOUTHERN LAKE HURON
MEANWHILE HAS NEW STORMS DEVELOPING WHICH WE WILL NEED TO KEEP AN
EYE ON...BUT I ANTICIPATE THAT PARTICULAR CLUSTER TO LIFT
NORTHEASTWARD. IT DOES PROVIDE A HINT TO WHAT MAY OCCUR LATER
TODAY HOWEVER. MORE ON THAT BELOW.
HIGH PRESSURE IS CURRENTLY SLIDING OUT OF QUEBEC TO MAINE/CANADIAN
MARITIME PROVINCES...INITIATING COOL AIR DAMMING DOWN THE
APPALACHIANS. SOUTHEAST LOW LEVEL FLOW WILL DEVELOP
TODAY...SETTING UP A SURFACE CONVERGENCE ZONE IN VICINITY OF
FINGER LAKES TO CENTRAL SOUTHERN TIER OF NY. TRAILING END OF WAVE
CURRENTLY FIRING CONVECTION IN SOUTHERN LAKE HURON...CONNECTING TO
THE ONTARIO PENINSULA TO NEAR ERIE PA...WILL LIFT NORTHEASTWARD
INTO CENTRAL SOUTHERN TIER JUST AS DIURNAL HEATING GETS GOING.
THIS COINCIDES WITH THE WEAK LOW LEVEL CONVERGENCE AS WELL. I THUS
HAVE PLACED HIGH CHANCE POPS IN CENTRAL SOUTHERN TIER TO FINGER
LAKES FOR LATE MORNING TO AFTERNOON TODAY. MODEL SOUNDINGS THERE
SHOW SUFFICIENT INSTABILITY FOR THUNDER TO ACCOMPANY THOSE
SHOWERS. HOWEVER...THE FARTHER EAST THAT ACTIVITY MANAGES TO
PROCEED...THE DEEPER INTO THE MORE STABLE SOUTHEAST FLOW /VIA COOL
AIR DAMMING ALONG EAST COAST/ IT WILL GET. THUS LOWER CHANCES FOR
SHOWERS AND ONLY SLIGHT CHANCE OF THUNDER AT MOST. I DO NOT EVEN
INCLUDE THUNDER MENTION IN WESTERN CATSKILLS TO POCONOS.
NOT QUITE AS WARM AS MONDAY...DUE TO CLOUD COVERAGE IN WEST AND
SOUTHEAST LOW LEVEL FLOW IN EAST...YET STILL 70S FOR MOST OF THE
AREA. LOWER ELEVATIONS IN TWIN TIERS TO FINGER LAKES COULD EVEN
MANAGE 80 DEGREES.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
3 PM UPDATE...
INTO THE AREA TUE NGT TO WED NGT. DIURNAL HEATING WILL HELP
CONVECTION DURING THE AFTN. IN WARM SECTOR WED AND THU WITH
DECENT SFC INSTABILITY BUT ONLY WEAK FORCING.
AS THE UL TROF MOVES EAST IT WILL FINALLY KICK THE COLD FRONT
THROUGH DURING THE EXTENDED. THIS SHORT TERM SOME SOAKING RAINS
BUT MAJORITY OF TIME WILL BE DRY. INCREASING HUMIDITY WITH DEWPTS
RISING INTO U50S AND L60S. MILD TEMPS AND FOLLOWED GUIDANCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
210 PM UPDATE...
EXTNDD PD STARTS OFF WITH H5 LOW BEGINNING TO CLOSE OFF IN THE WRN
GREAT LKS WITH FRONTAL BNDRY MEANDERING NR AREA THRU THE END OF THE
WEEK AND FIRST HALF OF THE WEEKEND. SVRL WVS OF LOPRES WL RIDE UP
ALONG BNDRY, WITH HEAVIEST RAIN LKLY THUR NGT AND FRI AHD OF CDFNT.
WITH BNDRY ON OUR DOORSTEP LATE THUR NGT/FRI MRNG EXPECT CHCS FOR
THUNDER AT ANY TIME TO START OFF THE LONG TERM. WL WORD IT AS CHC
TSTMS FOR THUR NGT WITH LKLY SHOWERS/THUNDER DRG THE DAY ON FRIDAY
WITH TIMING LKLY TO BE NAILED DOWN THE CLOSER WE GET TO THE END OF
THE WEEK. LATEST EURO IS FASTER THAN THE GFS/CMC ON PROGRESSION OF
FROPA WITH LATTER MODELS DELAYING ITS ARRIVAL UNTIL CLOSE TO 00Z SAT
WHILE EURO CLRS CWA BY 12Z FRIDAY.
UNSETTLED WX CONTS THRU THE EARLY PART OF THE WEEK AS ERN U.S. TROF
RMNS IN PLACE. LATEST GFS INDICATE H5 LOW CLOSING OFF AGAIN OVR THE
NORTHEAST U.S. ON MONDAY THUS WL KEEP CHC POPS IN AFT 12Z SATURDAY
WITH POTENTIAL COLD POOL ALOFT CAUSING INSTABILITY SHOWERS.
TEMPS THRU THE PD WL BE NR NORMAL TO SLIGHTLY BLO NORMAL UNDER
EXTENSIVE CLD CVR AND SHOWERY CONDS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
CHALLENGING FCST EARLY THIS MORNING AS MUCH OF CENTRAL NY AND
NORTHEAST PA REMAINS POSITIONED BETWEEN TWO SEPARATE AREAS OF
RAINFALL. THE FIRST OF THESE IS NOW MOVING THROUGH WESTERN NY
WITH LGT SHWR ACTIVITY NOTED ACROSS THE CENTRAL LAKE ONTARIO LAKE
SHORE. THE SECOND REGION...IN THE FORM OF A WEAKLY ORGANIZED
MCS...NOW DIVING SOUTH ACROSS SOUTH-CENTRAL PA WITH REDEVELOPING
ACTIVITY NOTED TO THE NORTH ACROSS NORTHWESTERN PA. WITH DEWPOINTS
RESIDING IN THE MID TO UPPER 50S ACROSS MUCH OF THE AREA...PLENTY
OF LOW-LEVEL MOISTURE IS IN PLACE FOR RADIATIONAL FOG FORMATION
FOR VALLEY LOCATIONS THAT SEE TEMPORARY CLEARING. FOR NOW...HAVE
ELECTED TO OFFER AN IFR VSBY MENTION AT ELM AFTER 9Z AS INCREASED
SUBSIDENCE BEHIND THE CENTRAL PA MCS MAY LEAD TO SOME TEMPORARY
CLEARING. ELSEWHERE...VFR CONDITIONS FCST THROUGH THE EARLY
MORNING WITH A LGT SHWR MENTION ADDED FOR SYR AND RME BASED ON
CURRENT LAKE ONTARIO SHORELINE ACTIVITY.
HEADING INTO TODAY...FCST MODELS SHOW DEVELOPING CONVECTION ACROSS
THE CENTRAL FINGER LAKES AS LOW-LEVEL CONVERGENCE INCREASES ALONG
A DEVELOPING SFC TROUGH. FOR NOW...HAVE ADDED TEMPO MENTIONS AT
BOTH ELM AND ITH LATER THIS AFTERNOON AND WILL AFFORD LATER
SHIFTS THE OPPORTUNITY TO ADD THUNDER IF CONDITIONS DO IN FACT
BECOME UNSTABLE ENOUGH LATER TODAY. FURTHER EAST...DRIER AIR
ASSOCIATED WITH HIGH PRESSURE ACROSS NEW ENGLAND WILL LIKELY KEEP
THE BULK OF SHWR ACTIVITY WEST OF I-81.
LGT SOUTHERLY WINDS BETWEEN 5-10 KTS EXPECTED THROUGH THE PERIOD.
OUTLOOK...
WED THROUGH THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN SHOWERS AND
THUNDERSTORMS.
THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS
COLD FRONT STALLS NEAR AREA.
SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE
AFTERNOON.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...TAC
LONG TERM...PVN
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
200 AM EDT TUE MAY 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH
WEDNESDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. OUR PATTERN WILL
REMAIN UNSETTLED INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
145 AM UPDATE...
REGIONAL RADAR CONTINUES TO SHOW COMPLEX OF STORMS DIVING THROUGH
SOUTHWEST PA...WHILE JUST A FEW SHOWERS EXIST OVER LAKE ONTARIO TO
THE ROCHESTER AREA. THE NORTHERN SHOWERS ARE ASSOCIATED WITH A
WAVE WHICH IS MOVING THROUGH AS PREVIOUSLY ANTICIPATED...BUT IT
HAS A LOT LESS ACTIVITY PROBABLY DUE TO SUBSIDENCE AROUND THE SW
PA COMPLEX. WRF- ARW...NAM...GEM...AND NMM ALL BRING NOCTURNAL
CONVECTION WITH WAVE INTO THE TWIN TIERS YET HAVE INITIALIZED WITH
SW PA COMPLEX TOTALLY MISSING. I AM THUS SIDING HRRR AND RUC13
SOLUTIONS WHICH HAVE THE SW PA COMPLEX AND ALSO KEEP THINGS PRETTY
QUIET THROUGH THE REMAINDER OF EARLY MORNING. SOUTHERN LAKE HURON
MEANWHILE HAS NEW STORMS DEVELOPING WHICH WE WILL NEED TO KEEP AN
EYE ON...BUT I ANTICIPATE THAT PARTICULAR CLUSTER TO LIFT
NORTHEASTWARD. IT DOES PROVIDE A HINT TO WHAT MAY OCCUR LATER
TODAY HOWEVER. MORE ON THAT BELOW.
HIGH PRESSURE IS CURRENTLY SLIDING OUT OF QUEBEC TO MAINE/CANADIAN
MARITIME PROVINCES...INITIATING COOL AIR DAMMING DOWN THE
APPALACHIANS. SOUTHEAST LOW LEVEL FLOW WILL DEVELOP
TODAY...SETTING UP A SURFACE CONVERGENCE ZONE IN VICINITY OF
FINGER LAKES TO CENTRAL SOUTHERN TIER OF NY. TRAILING END OF WAVE
CURRENTLY FIRING CONVECTION IN SOUTHERN LAKE HURON...CONNECTING TO
THE ONTARIO PENINSULA TO NEAR ERIE PA...WILL LIFT NORTHEASTWARD
INTO CENTRAL SOUTHERN TIER JUST AS DIURNAL HEATING GETS GOING.
THIS COINCIDES WITH THE WEAK LOW LEVEL CONVERGENCE AS WELL. I THUS
HAVE PLACED HIGH CHANCE POPS IN CENTRAL SOUTHERN TIER TO FINGER
LAKES FOR LATE MORNING TO AFTERNOON TODAY. MODEL SOUNDINGS THERE
SHOW SUFFICIENT INSTABILITY FOR THUNDER TO ACCOMPANY THOSE
SHOWERS. HOWEVER...THE FARTHER EAST THAT ACTIVITY MANAGES TO
PROCEED...THE DEEPER INTO THE MORE STABLE SOUTHEAST FLOW /VIA COOL
AIR DAMMING ALONG EAST COAST/ IT WILL GET. THUS LOWER CHANCES FOR
SHOWERS AND ONLY SLIGHT CHANCE OF THUNDER AT MOST. I DO NOT EVEN
INCLUDE THUNDER MENTION IN WESTERN CATSKILLS TO POCONOS.
NOT QUITE AS WARM AS MONDAY...DUE TO CLOUD COVERAGE IN WEST AND
SOUTHEAST LOW LEVEL FLOW IN EAST...YET STILL 70S FOR MOST OF THE
AREA. LOWER ELEVATIONS IN TWIN TIERS TO FINGER LAKES COULD EVEN
MANAGE 80 DEGREES.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
3 PM UPDATE...
INTO THE AREA TUE NGT TO WED NGT. DIURNAL HEATING WILL HELP
CONVECTION DURING THE AFTN. IN WARM SECTOR WED AND THU WITH
DECENT SFC INSTABILITY BUT ONLY WEAK FORCING.
AS THE UL TROF MOVES EAST IT WILL FINALLY KICK THE COLD FRONT
THROUGH DURING THE EXTENDED. THIS SHORT TERM SOME SOAKING RAINS
BUT MAJORITY OF TIME WILL BE DRY. INCREASING HUMIDITY WITH DEWPTS
RISING INTO U50S AND L60S. MILD TEMPS AND FOLLOWED GUIDANCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
210 PM UPDATE...
EXTNDD PD STARTS OFF WITH H5 LOW BEGINNING TO CLOSE OFF IN THE WRN
GREAT LKS WITH FRONTAL BNDRY MEANDERING NR AREA THRU THE END OF THE
WEEK AND FIRST HALF OF THE WEEKEND. SVRL WVS OF LOPRES WL RIDE UP
ALONG BNDRY, WITH HEAVIEST RAIN LKLY THUR NGT AND FRI AHD OF CDFNT.
WITH BNDRY ON OUR DOORSTEP LATE THUR NGT/FRI MRNG EXPECT CHCS FOR
THUNDER AT ANY TIME TO START OFF THE LONG TERM. WL WORD IT AS CHC
TSTMS FOR THUR NGT WITH LKLY SHOWERS/THUNDER DRG THE DAY ON FRIDAY
WITH TIMING LKLY TO BE NAILED DOWN THE CLOSER WE GET TO THE END OF
THE WEEK. LATEST EURO IS FASTER THAN THE GFS/CMC ON PROGRESSION OF
FROPA WITH LATTER MODELS DELAYING ITS ARRIVAL UNTIL CLOSE TO 00Z SAT
WHILE EURO CLRS CWA BY 12Z FRIDAY.
UNSETTLED WX CONTS THRU THE EARLY PART OF THE WEEK AS ERN U.S. TROF
RMNS IN PLACE. LATEST GFS INDICATE H5 LOW CLOSING OFF AGAIN OVR THE
NORTHEAST U.S. ON MONDAY THUS WL KEEP CHC POPS IN AFT 12Z SATURDAY
WITH POTENTIAL COLD POOL ALOFT CAUSING INSTABILITY SHOWERS.
TEMPS THRU THE PD WL BE NR NORMAL TO SLIGHTLY BLO NORMAL UNDER
EXTENSIVE CLD CVR AND SHOWERY CONDS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A VERY LOW CONFIDENCE FCST THIS PD. FNTL BNDRY WAVERING OVER THE
CWA. S/WV OVER MI COULD RESULT IN CONVECTION LATER TNGT NEAR THIS
BNDRY.
VFR WILL PREVAIL THIS EVNG WITH ISOLD --SHRA AND A BKN MID DECK.
AFTER 06Z...POTNL FOR CONVECTION TO DROP SEWD INTO CNTRL NY OR
DVLP IN-SITU ALONG THE BNDRY OVER CNTRL NY. BASICALLY...TAF FCSTS
WILL BE IN "NOWCAST" MODE ONCE SHRA/TSRA DVLP. FOR NOW WE INDICATE
A CHC FOR MVFR VSBY`S LATE TNGT AND EARLY TMRW MRNG ACRS CNTRL NY
IN SHRA. BIG QUESTIONS TMRW CONCERNING POTNL FOR CONVECTIVE
DVLPMNT. MANY SITES COULD SEE TSRA AND RESTRICTIONS...FOR NOW
WE`LL JUST INDICATE CHCS FOR SHRA AND MVFR VSBY`S AT A FEW SITES.
WINDS TNGT GNRLY L&V BECMG S TO SE ON TUE 10-15 KTS.
OUTLOOK...
TUES NGT THROUGH THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN
SHOWERS AND THUNDERSTORMS.
THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS
COLD FRONT STALLS NEAR AREA.
SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE
AFTERNOON.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...TAC
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1240 AM CDT TUE MAY 13 2014
.UPDATE...
ISSUED AT 1240 AM CDT TUE MAY 13 2014
NO SIGNIFICANT CHANGES FOR THE EARLY MORNING UPDATE. MINOR CHANGES
IN HOURLY TEMPERATURES WITH TEMPERATURES A BIT LOWER THAN FORECAST
IN THE WEST.
UPDATE ISSUED AT 934 PM CDT MON MAY 12 2014
NO SIGNIFICANT CHANGES FOR LATE EVENING UPDATE OTHER THAN TRIM LOW
POPS FROM THE FAR SOUTHEAST.
UPDATE ISSUED AT 700 PM CDT MON MAY 12 2014
EARLY EVENING UPDATE TO EXPIRE WIND ADVISORY AS WINDS WILL
CONTINUE TO GRADUALLY DIMINISH DURING THE EARLY EVENING. THE FAR
SOUTHEAST FRINGE MAY SEE SOME LINGERING SHOWERS THROUGH MID TO
LATE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 329 PM CDT MON MAY 12 2014
MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE WINDS ACROSS
THE AREA THROUGH THE REMAINDER OF THE AFTERNOON...PRECIPITATION
ENDING IN THE EAST THIS EVENING AND OVERNIGHT TEMPERATURES.
CURRENTLY...SURFACE LOW PRESSURE OVER SOUTHEAST MINNESOTA WITH AN
INVERTED TROUGH NORTH THROUGH NORTHERN MINNESOTA. THE DEFORMATION
ZONE ASSOCIATED WITH THIS LOW PRESSURE SYSTEM WILL CONTINUE TO
TRACK EAST THIS EVENING AND RAIN SHOWERS WILL END OVER THE JAMES
RIVER VALLEY THIS EVENING.
LATEST RAP SOUNDINGS INDICATE THAT AREAS ALONG AND WEST OF
HIGHWAY 83 WILL SEE DIMINISHING WINDS THIS EVENING. IT MAY BE
BREEZY THROUGH AROUND 9 PM BUT WINDS SHOULD REMAIN BELOW ADVISORY
LEVELS. WINDS COULD HOLD ON OVER EASTERN PORTIONS OF CENTRAL NORTH
DAKOTA WITH KJMS AND CARRINGTON 19 UTC BUFR SOUNDINGS INDICATING
THE BOUNDARY LAYER REMAINING LIFTED WITH 40 KNOT WINDS AVAILABLE
TO WORK DOWN. GRADIENT WINDS WILL BE STRONGEST HERE ALSO...CLOSER
TO THE SURFACE LOW. WILL KEEP THE ADVISORY GOING AND EVENING SHIFT
WILL NEED TO LOOK INTO POSSIBLY EXTENDING EASTERN PORTIONS OF THE
ADVISORY.
CONVECTIVE CUMULUS FLATTENING OUT SHOULD SLOWLY DISSIPATE THIS
EVENING. THUS MOSTLY CLEAR SKIES ARE EXPECTED BY MORNING. WILL SEE
LOWS IN THE LOW TO MID 30S MOST AREAS. WINDS SHOULD REMAIN AT 5 TO
10 MPH OVERNIGHT...KEEPING TEMPERATURES FROM FALLING INTO THE
20S. MID 30S ARE EXPECTED OVER EASTERN PORTIONS OF CENTRAL NORTH
DAKOTA WHERE WINDS AND CLOUDS HANG ON LONGER TONIGHT.
TUESDAY WILL BE MUCH NICER THAN TODAY OVER THE JAMES RIVER
VALLEY...WITH NO RAIN...LESS WIND AND MORE SUN. ELSEWHERE...TUESDAY
IS EXPECTED TO SIMILAR TO TODAY...BUT WITH A LITTLE LESS CLOUDS
AND WINDS AND A LITTLE MORE SUNSHINE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 329 PM CDT MON MAY 12 2014
TROUGH MOVES EAST WEDNESDAY WITH NORTHWEST FLOW ALOFT DEVELOPING AND
PERSISTING THROUGH THE FIRST HALF OF NEXT WEEKEND. EMBEDDED WAVE IS
DEPICTED TO MOVE THROUGH SOMETIME THURSDAY NIGHT OR FRIDAY BRINGING
A CHANCE FOR SHOWERS TO THE LOCAL AREA. OTHERWISE THE REST OF THE
WORK WEEK APPEARS MAINLY DRY.
12Z GFS/ECMWF SHOW A SHORT WAVE RIDGE SATURDAY NIGHT FOLLOWED BY A
MORE ACTIVE FLOW SUNDAY INTO MONDAY AHEAD AND ALONG A DEVELOPING
TROUGH ORIGINATING OVER THE PACIFIC NORTHWEST AND PROGRESSING
EASTWARD. MILDER TEMPERATURES OVER THE WEEKEND AS WELL...HELPING TO
INCREASE THE POTENTIAL FOR THUNDERSTORMS SUNDAY-MONDAY. UNCERTAINTY
STILL HIGH SO WILL LEAVE OUT OF THE FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1240 AM CDT TUE MAY 13 2014
EXPECT NORTHWEST WINDS AT 10 KNOTS OR LESS AT KISN/KMOT/KDIK/KBIS
AND AT 14 KNOTS OR LESS AT KJMS UNTIL AROUND 12Z-15Z WHEN NORTHWEST
WINDS BEGIN INCREASING...REACHING 20 KNOTS OR MORE WITH GUSTS TO 30
KNOTS POSSIBLE IN THE AFTERNOON...BEFORE DIMINISHING AFT 01Z.
SCATTERED TO BROKEN VFR CIGS THROUGH THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...TWH
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1233 AM CDT TUE MAY 13 2014
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 755 PM CDT MON MAY 12 2014/
UPDATE...
THE WEATHER PATTERN THIS EVENING ACROSS THE MIDSOUTH IS TURNING
TOWARD A MORE ACTIVE ONE FOR NEXT COUPLE OF DAYS. A STRONG COLD
FRONT STRETCHED FROM NORTHEAST MO INTO WESTERN AR AND NORTHEAST
TX. WARM...MOIST AND UNSTABLE AIR WAS PUSHING INTO THE MIDSOUTH
ON MODERATE SOUTHERLY WINDS. THE 00Z LZK SOUNDING INDICATED A
SBCAPE OF 3700 J/KG WITH A PRECIPITABLE WATER VALUE OF 1.58
INCHES. SURFACE DEW POINTS WERE IN THE MIDDLE AND UPPER 60S. A
SOLID LINE OF THUNDERSTORMS EXTENDED AHEAD OF THE COLD FRONT AND
WAS PUSHING EASTWARD INTO NORTH CENTRAL AR. SCATTERED SHOWERS AND
THUNDERSTORMS WERE DEVELOPING ACROSS THE MIDSOUTH ALONG AND WEST
OF THE MS RIVER...THIS IS DEPICTED WELL BY THE HRRR MODEL...WITH
THIS CONVECTION MOVING TO NORTH. THE LINE OF STORMS AHEAD OF THE
FRONT WILL MOVE INTO NORTHEAST AR AND THE MO BOOTHEEL LATER
TONIGHT WITH HEAVY RAINFALL THE MAIN THREAT...A FLASH FLOOD WATCH
BEGINS FOR THE AREA AFTER MIDNIGHT.
UPDATED TO REMOVE OUTDATED WORDING. OTHERWISE...CURRENT FORECAST
HAS A GOOD HANDLE ON THE DEVELOPING SITUATION. HOWEVER...MAY NEED TO
EXTEND SMALL POPS A LITTLE FURTHER EASTWARD OVER PORTIONS OF NORTH
MS IF ISOLATED CONVECTION OVER NORTH CENTRAL MS HOLD TOGETHER AS
IT MOVES NORTHWARD.
JCL
DISCUSSION... /ISSUED 348 PM CDT MON MAY 12 2014/
A DEEP UPPER LEVEL TROUGH CONTINUES TO SLOWLY PUSH EAST THROUGH
THE PLAINS STATES THIS AFTERNOON. AT THE SURFACE...A COLD FRONT
HAS ADVANCED EASTWARD INTO WESTERN MISSOURI AND EASTERN OKLAHOMA.
A LINE OF THUNDERSTORMS HAS FORMED ALONG THE FRONT AND CONTINUES
TO ADVANCE EASTWARD. TO THE EAST...ACROSS MUCH OF THE MID
SOUTH...ABUNDANT LOW LEVEL MOISTURE ALONG WITH SURFACE HEATING HAS
SUPPORTED ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THIS
ACTIVITY SHOULD DIMINISH IN COVERAGE THIS EVENING WITH MAINLY DRY
WEATHER PERSISTING EAST OF THE MISSISSIPPI RIVER THROUGH MIDNIGHT.
TO THE WEST OF THE RIVER...THE LINE OF STORMS NOW MOVING ACROSS
EASTERN OKLAHOMA WILL ADVANCE INTO WESTERN PORTIONS OF THE
FORECAST AREA WELL AFTER MIDNIGHT. THESE STORMS SHOULD BE TRENDING
WEAKER BY THE TIME IT REACHES OUR AREA...AS THEY BEGIN TO PUSH
AHEAD OF THE BETTER FORCING ALOFT THAT WILL BE FOCUSED FURTHER
WEST.
LINGERING MORNING SHOWERS ACROSS THE WEST SHOULD FALL APART DURING
THE MORNING HOURS TUESDAY...BEFORE NEW ACTIVITY FORMS ALONG THE
ADVANCING COLD FRONT ACROSS EASTERN ARKANSAS AND THE MISSOURI
BOOTHEEL. THIS ACTIVITY SHOULD BE SLOW MOVING AND ONLY ADVANCE AS
FAR EAST AS THE MISSISSIPPI RIVER COUNTIES BY TUESDAY AFTERNOON.
SLOW MOVEMENT AND POSSIBLE TRAINING OF THUNDERSTORMS MAY LEAD TO
SOME HEAVY RAINFALL ACROSS AREAS WEST OF THE MISSISSIPPI RIVER. A
FLASH FLOOD WATCH HAS BEEN ISSUED FOR THESE LOCATIONS ON TUESDAY.
FURTHER EAST...DAYTIME HEATING AND INCREASING INSTABILITY MAY
RESULT IN SCATTERED PULSE TYPE SHOWERS AND THUNDERSTORMS.
A MORE POTENT SHORTWAVE WILL BEGIN TO EJECT OUT OF THE BASE OF THE
UPPER TROUGH TO OUR WEST TUESDAY NIGHT INTO WEDNESDAY. BY THIS
TIME...THE SURFACE COLD FRONT SHOULD BE POSITIONED ACROSS WEST
TENNESSEE INTO NORTHWEST MISSISSIPPI. NUMEROUS SHOWERS AND
THUNDERSTORMS WILL DEVELOP ON THE COLD SIDE OF THE BOUNDARY
TUESDAY NIGHT WITH CONTINUED POTENTIAL FOR HEAVY RAINFALL. AS THE
SHORTWAVE MOVES EAST ON WEDNESDAY...IT MAY TAKE ON A MORE NEUTRAL
TO EVEN POSITIVE TILT ORIENTATION AS IT OVERSPREADS THE REMAINDER
OF THE MID SOUTH BY WEDNESDAY AFTERNOON. AS THIS
OCCURS IT SHOULD HELP TO INDUCE A SURFACE LOW PRESSURE SYSTEM
WHICH SHOULD LIFT NORTHEAST ACROSS EASTERN PORTIONS OF THE
FORECAST AREA. THUNDERSTORMS SHOULD DEVELOP ACROSS THE REMAINING WARM
SECTOR IN PLACE ACROSS PORTIONS OF WEST TENNESSEE...NEAR THE
TENNESSEE RIVER...INTO NORTHEAST MISSISSIPPI. THE AIRMASS ACROSS
THE WARM SECTOR SHOULD REMAIN WARM AND HUMID WITH DEEP LAYER SHEAR
VALUES INCREASING IN ADVANCE OF THE SHORTWAVE. INSTABILITY AND
SHEAR MAY BE SUFFICIENT TO RESULT IN A FEW SEVERE THUNDERSTORMS
OVER THE AFOREMENTIONED REGIONS WEDNESDAY AFTERNOON AND EVENING.
THERE STILL REMAINS SOME UNCERTAINTY WITH REGARD TO THE QUALITY OF
THE WARM SECTOR AND HOW MUCH INSTABILITY WILL EXIST. LATER SHIFTS
WILL CONTINUE TO MONITOR THIS SEVERE WEATHER POTENTIAL AND WILL
PROVIDE FORECAST UPDATES AS NEEDED.
THE COLD FRONT SHOULD MOVE EAST OF THE REGION WEDNESDAY NIGHT WITH
SHOWERS AND THUNDERSTORMS ENDING FROM WEST TO EAST. AN UPPER LEVEL
LOW PRESSURE SYSTEM OVER THE UPPER MISSISSIPPI VALLEY WILL DROP
SOUTHEAST INTO THE MIDWEST THROUGH THE END OF THE WEEK AND INTO
THE FIRST PART OF NEXT WEEKEND. A SERIES OF SHORTWAVE DISTURBANCES
WILL ROTATE ACROSS THE AREA ALONG THE SOUTHERN PERIPHERY OF THIS
UPPER LOW. THIS SHOULD KEEP CHANCES FOR SHOWERS AND A FEW
THUNDERSTORMS IN THE FORECAST DURING THIS TIME PERIOD. IN
ADDITION...MUCH COOLER TEMPERATURES CAN BE EXPECTED. IN
FACT...TEMPERATURES SHOULD AVERAGE ANYWHERE FROM 10-20 DEGREES
BELOW AVERAGE FOR THIS TIME OF THE YEAR.
THE UPPER LOW WILL FINALLY MOVE EAST BY THE END OF NEXT WEEKEND
WITH A RETURN TO DRY CONDITIONS AND WARMER TEMPERATURES.
JLH
&&
.06Z TAF CYCLE
VFR CONDITIONS WILL CONTINUE THROUGH MOST OF THE OVERNIGHT HOURS. A
LINE OF SHOWERS AND THUNDERSTORMS WILL BEGIN TO MOVE INTO THE
FORECAST AREA OVERNIGHT AND SLOWLY MOVE EAST THROUGH THE REMAINDER
OF FORECAST PERIOD. EXPECT MVFR VISIBILITIES AND MVFR/IFR CEILINGS
WITH THIS LARGE AREA OF CONVECTION. WINDS WILL BE SOUTH AT 10 TO 15
KNOTS OVERNIGHT AND GRADUALLY SHIFT TO A MORE NORTHWESTERLY
DIRECTIONS OVER WESTERN SECTIONS OF THE FORECAST AREA BY TUESDAY
AFTERNOON.
ARS
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
355 AM CDT TUE MAY 13 2014
.SHORT TERM...
COLD DRY AIRMASS CONTINUES TO SPREAD INTO THE REGION WITH ENOUGH
SURFACE PRESSURE GRADIENT TO SUPPORT 20-25 MPH WIND SPEEDS AT LEAST
THIS MORNING. A SHARP UPPER TROUGH OVER THE SOUTHERN AND CENTRAL
ROCKIES THIS MORNING WILL EDGE INTO THE AREA DURING THE DAY
SPREADING MODEST DEEP LIFT AND WEAK MID LEVEL INSTABILITY INTO THE
AREA WHILE LOWER ATMOSPHERE WILL MAKE EFFECTIVE SHOWER CHANCES
DIFFICULT. THE WRF/NAM WHICH HAS BEEN QUITE WET TODAY FOR A NUMBER
OF RUNS HAS TRENDED SLIGHTLY DRIER THOUGH HAS RETAINED LIGHT RAIN
SHOWER SIGNAL MAINLY SOUTHEAST ZONES LATER TODAY...WHILE THE
HOUR-BY-HOUR HRRR SOLUTION HAS BEEN TRENDING JUST SLIGHTLY WETTER AS
THESE SOLUTIONS ATTEMPT TO MATCH UP BETTER. WE WILL RETAIN THE
SLIGHT CHANCE OF SHOWERS SOUTHEAST LATER TODAY ALONG WITH A MENTION
OF SPRINKLES THIS MORNING ON THE CAP-ROCK. THESE VERY LIGHT SHOWERS
COULD EXTEND JUST INTO THE EARLY AFTERNOON FOR CENTRAL ZONES BUT
EITHER WAY WE DO NOT EXPECT A BIG DEAL. QUITE COOL AIRMASS TODAY
CLOSE TO 20 DEGREES SHORT OF NORMAL FOR THE DATE AND AS SKIES CLEAR
ON THE BACK SIDE OF THE UPPER TROUGH THIS EVENING ALONG WITH WINDS
AND SURFACE DEWPOINTS ALSO TRENDING LOWER...SHOULD LEAD TO A VERY
CHILLY NIGHT ON THE CAPROCK. WE RETAINED THE PREVIOUS LOW
TEMPERATURE FORECAST FOR TONIGHT AND ADDED A FREEZE WATCH FOR OUR
WEST/NORTHWESTERN 5 COUNTIES. RMCQUEEN
&&
.LONG TERM...
COOLER THAN AVERAGE TEMPERATURES WILL STICK AROUND THROUGH
WEDNESDAY AS WE WILL REMAIN UNDER THE INFLUENCE OF THE UPPER LEVEL
TROUGH MOVING OFF EAST OF THE AREA. A RIDGE OVER THE WEST COAST
WILL DEAMPLIFY AS IT MOVES THROUGH THE ROCKIES LATER THIS WEEK.
THIS WILL STILL LEAD TO RISING HEIGHTS AND INCREASING TEMPERATURES
THROUGH EARLY NEXT WEEK.
A WEAK FRONT WILL PASS THROUGH THE AREA LATE THURSDAY GIVING WAY
TO UPSLOPE WINDS ON FRIDAY. THE ECMWF HAS CONSISTENTLY BEEN
DEPICTING LIGHT QPF VALUES ON FRIDAY MORNING UNDER THIS UPSLOPE
FLOW. IT DEVELOPS WEAK MOIST ISENTROPIC UPGLIDE ALTHOUGH THE ECMWF
DIFFERS WITH THE GFS IN REGARDS TO THE MOIST PORTION. LOW STRATUS
MAY BE THE ONLY RESULT OF THIS LOW LEVEL FLOW. FROM THE EARLY
PORTION TO THE MIDDLE OF NEXT WEEK A LOW AMPLITUDE RIDGE WILL
BUILD OVER THE PLAINS AND MIDWEST AS A TROUGH FORMS NEAR THE
INTERMOUNTAIN WEST. THIS MAY PROVIDE AN OPPORTUNITY FOR
THUNDERSTORMS WITH LOW LEVEL MOISTURE RETURNING UNDER THIS TYPE OF
PATTERN.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 60 32 67 39 76 / 10 0 0 0 0
TULIA 62 36 67 39 76 / 10 0 0 0 0
PLAINVIEW 62 37 67 40 77 / 10 0 0 0 0
LEVELLAND 63 37 68 40 78 / 10 0 0 0 0
LUBBOCK 64 38 69 41 78 / 10 10 0 0 0
DENVER CITY 63 37 69 41 78 / 10 10 0 0 0
BROWNFIELD 63 37 69 41 78 / 10 10 0 0 0
CHILDRESS 67 43 73 44 81 / 10 10 0 0 0
SPUR 64 39 71 43 80 / 20 10 0 0 0
ASPERMONT 65 44 72 44 81 / 20 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR THE
FOLLOWING ZONES: TXZ021-022-027-028-033.
&&
$$
05/01
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1144 PM CDT MON MAY 12 2014
.UPDATE...
ISSUED AT 810 PM CDT MON MAY 12 2014
WITH A WEAKLY CAPPED ENVIRONMENT TO THE SOUTH AND
EAST...CONVECTION DEVELOPED QUICKLY ALONG THE BRIM OF THE WARM
SECTOR AND BASICALLY CUT OFF THE LOCAL REGION OF ANY SIGNIFICANT
CONVECTION. BECAUSE OF THIS...HAVE ENDED BOTH THE SEVERE
THUNDERSTORM WATCH AND FLASH FLOOD WATCH FOR THE REGION AS BOTH
THREATS HAVE GONE TO THE EAST.
THE MAIN FOCUS NOW IS ON THE COLD FRONT WHICH JUST WENT THROUGH
ROCHESTER MN AND CHARLES CITY IOWA. TEMPERATURES DROP FROM THE LOW
70S TO THE MID 50S WITH WINDS TURNING TO THE NORTHWEST AS THE
FRONT PASSES. DRIZZLE IS ALSO OCCURRING BEHIND THE FRONT AS WELL
AND WILL LAST FOR A PERIOD THIS EVENING AND OVERNIGHT UNTIL DRIER
850MB AIR COMES IN ON THE BACK SIDE OF THE SYSTEM.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 328 PM CDT MON MAY 12 2014
FOCUS OF THE FORECAST IS ON THE RAIN CHANCES AND IMPACTS TONIGHT.
LATEST SURFACE ANALYSIS SUGGESTS THE INVERTED TROUGH/COLD FRONT
EXTENDS FROM NORTHWEST WISCONSIN INTO WESTERN WISCONSIN. HARD TO
DEFINE A COMPACT AREA OF LOW PRESSURE BUT LOOKS TO BE MORE OF AN
ELONGATED FEATURE ALONG THE TROUGH/FRONT FROM SOUTHEAST MINNESOTA
ACROSS MUCH OF IOWA. A WARM FRONT LOOKED TO EXTEND ACROSS
NORTHEAST IOWA INTO NORTHERN ILLINOIS...ROUGHLY ALONG THE HIGHWAY
20 CORRIDOR. LOCAL AND REGIONAL RADARS SHOWING A LINE OF
CONVECTION ALONG THE COLD FRONT FROM NORTHEAST IOWA INTO WESTERN
MISSOURI/EASTERN KANSAS.
LATEST ANALYSIS INDICATES AROUND 500 J/KG OF SB CAPE WAS ALONG
INTERSTATE 90 BUT THIS INCREASED TO ALMOST 2000 J/KG ALONG THE
SOUTHERN BORDER OF THE FORECAST AREA. THE 12.18Z RAP SUGGESTS
THESE HIGHER CAPE VALUES WILL SPREAD ACROSS THE EASTERN PARTS OF
THE FORECAST AREA THROUGH THE REST OF THE AFTERNOON INTO THE EARLY
EVENING. THE RAP BUFKIT SOUNDINGS STILL SUGGESTS THIS IS
PRIMARILY A TALL SKINNY CAPE PROFILE WHICH WOULD SUGGEST THAT
LARGE HAIL MAY NOT BE MUCH OF A THREAT. FOR ANY STORMS THAT GET
INTO THE AREA AND CAN ORIENT WITH THE 0-3KM SHEAR
VECTORS...DAMAGING WIND WILL BE POSSIBLE. CANNOT TOTALLY RULE OUT
AN ISOLATED TORNADO AS THE WARM FRONT MOVES INTO THE AREA...BUT
BECAUSE OF THE ELONGATED SURFACE LOW...NOT REALLY SEEING ANY
LOCALIZED BACKING OF THE WINDS TO ENHANCE THE LOW LEVEL HELICITY.
CURRENTLY EXPECTING THE LINE OF ACTIVITY ACROSS IOWA INTO MISSOURI
TO CONTINUE TRANSLATING NORTHEAST AHEAD OF THE TROUGH/FRONT AND
PRIMARILY AFFECTING THE EASTERN SECTIONS OF THE FORECAST AREA FROM
NORTHEAST IOWA INTO CENTRAL WISCONSIN. HAVE LINED UP THE RAIN
CHANCES WITH 80 PERCENT OVER THIS AREA TRAILING BACK TO ABOUT A 40
PERCENT CHANCE ACROSS THE WEST. AS THE TROUGH/COLD FRONT ADVANCES
SLOWLY EAST TONIGHT...THE RAIN CHANCES WILL ESSENTIALLY END FROM
WEST TO EAST AND EXPECT THE ENTIRE AREA TO BE DRY BY 12Z TUESDAY.
AFTER TONIGHT...SOME SMALL RAIN CHANCES RETURN TO THE SOUTHEAST
PARTS OF THE FORECAST AREA WEDNESDAY NIGHT. THE MEAN LONG WAVE
TROUGH WILL REMAIN OVER THE CENTRAL PART OF THE COUNTRY THANKS TO
AN UPPER LEVEL LOW NEAR HUDSON BAY AND ANOTHER SHORT WAVE TROUGH
COMING OUT OF THE SOUTHWEST PART OF THE COUNTRY. THIS SHORT WAVE
TROUGH IS EXPECTED TO PASS OFF JUST TO THE SOUTHEAST OF THE AREA
ACROSS ILLINOIS WITH THE SURFACE LOW NEAR THE OHIO RIVER. THE
DEFORMATION AREA OF RAIN ON THE NORTHWEST SIDE OF THE LOW COULD
EXTEND BACK INTO THE AREA AND WILL HAVE THE SMALL RAIN CHANCES FOR
THIS POSSIBILITY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 328 PM CDT MON MAY 12 2014
THE LONG WAVE TROUGH WILL THEN MOVE SLOWLY NORTHEAST AS SEVERAL
WEAKER SHORT WAVE TROUGHS COME INTO THE LONG WAVE TROUGH ON THE
NORTHWEST FLOW FROM SOUTHERN AND WESTERN CANADA. THIS WILL PROVIDE
JUST ENOUGH FORCING FOR SOME SMALL RAIN CHANCES THURSDAY THROUGH
FRIDAY...SATURDAY AND AGAIN MONDAY. TEMPERATURES WILL STILL BE
COOL TO CLOSE OUT THE WEEK BUT THEN START TO MODERATE FOR THE
WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1144 PM CDT MON MAY 12 2014
IFR CEILINGS HAVE MOVED IN ACROSS SOUTHEAST MINNESOTA AND WILL
CONTINUE TO TRACK EAST INTO LSE OVER THE NEXT FEW HOURS AS A COLD
FRONT PUSHES INTO WESTERN WISCONSIN. DRIZZLE AND REDUCED
VISIBILITIES ARE ALSO OCCURRING...BUT THE MAIN ISSUE WITH WITH THE
LOW CEILINGS BETWEEN 500-900FT. CONDITIONS ARE EXPECTED TO IMPROVE
GRADUALLY THROUGH THE LATE MORNING/AFTERNOON HOURS ON TUESDAY AS
DRIER AIR MOVES INTO THE REGION. WINDS WILL BE GUSTY OUT OF THE
WEST NORTHWEST THROUGH TUESDAY AFTERNOON BEFORE DECREASING IN THE
EVENING.
&&
.HYDROLOGY...
ISSUED AT 328 PM CDT MON MAY 12 2014
AS THE STORMS COME IN ACROSS THE EASTERN SECTIONS TONIGHT...THE
TALL SKINNY CAPE PROFILE SHOULD LEAD TO MORE RAIN DROP PRODUCTION
INSTEAD OF HAIL. THIS CAN ALSO BE SEEN IN THE WARM CLOUD
DEPTHS...WHICH THE 12.18Z NAM CONTINUES TO SHOW TO BE AROUND 3500
METERS. WHILE THE QPF THAT FALLS THROUGH THE REST OF THE AFTERNOON
AND EVENING MAY BE AN INCH OR LESS...IT WILL BE FALLING ON GROUND
THAT RECEIVED UP TO 1.5 INCHES SUNDAY NIGHT. WITH THE GROUND BEING
SATURATED FROM THESE PREVIOUS RAINS...THE ADDITIONAL RAIN COULD
STILL PRODUCE SOME LOCALIZED FLOODING PROBLEMS AND WILL CONTINUE
THE FLASH FLOOD WATCH FOR ALL BUT THE FAR NORTHWEST SECTION OF THE
FORECAST AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1121 PM CDT MON MAY 12 2014
.UPDATE...
CONVECTION IS WINDING DOWN LATE THIS EVENING AS THE BETTER 500MB
VORTICITY ADVECTION AND SURFACE THETA-E ADVECTION MOVES OUT OVER
LAKE MICHIGAN AND CAPE IS DIMINISHING. SURFACE L0W PRESSURE OVER
WEST CENTRAL WI WILL DRIFT NORTHEAST INTO UPPER MICHIGAN THROUGH THE
REST OF THE NIGHT. THE TRAILING COLD FRONT CURRENTLY EXTENDING SOUTH
FROM THE LOW ALONG THE MN/WI BORDER INTO EASTERN IOWA WILL GRADUALLY
SHIFT EAST AS WELL.
AHEAD OF THE COLD FRONT...AMPLE MOISTURE AND 850MB FRONTOGENESIS
WILL CONTINUE TO SUPPORT LIGHT STRATIFORM RAIN ACROSS SOUTHERN WI
THROUGH MUCH OF THE NIGHT. PRECIPITABLE WATER VALUES ARE STILL
OVER 1.5 INCHES. FLASH FLOODING CONCERNS ARE TAPERING OFF WITH THE
CONVECTION...BUT WE WILL CONTINUE TO MONITOR RIVER LEVELS FOR
RISING RIVERS APPROACHING BANKFULL AND FLOOD STAGES.
DRIER AIR WILL WORK INTO SOUTHERN WI BEHIND THE FRONT. THE HRRR
AND OTHER MESO MODELS TIME THAT FRONT INTO SOUTH CENTRAL WI AROUND
4 AM AND SOUTHEAST WI 6-7 AM.
&&
.AVIATION/06Z TAFS/...
CONVECTION IS WINDING DOWN BUT LIGHT RAIN WILL CONTINUE THROUGH MUCH
OF THE NIGHT. DRIER AIR WILL WORK INTO SOUTHERN WI FROM WEST TO EAST
BETWEEN 4 AM AND 7 AM TUESDAY MORNING AND SCOUR OUT THE REMAINING
SHOWERS.
EXPECTING CEILINGS TO LOWER TO MVFR LEVELS LATE TONIGHT THROUGH TUE
MORNING...THEN RECOVER TO VFR DURING THE AFTERNOON.
&&
.MARINE...
ALLOWED DENSE FOG ADVISORY TO EXPIRE AT 10 PM SINCE WEB CAMS SHOWED
IMPROVEMENT TO VISIBILITIES OVER THE LAKESHORE DUE TO THE RECENT
THUNDERSTORMS.
THERE IS POTENTIAL FOR THE VISIBILITIES TO DROP AGAIN LATE TONIGHT
INTO TUESDAY MORNING UNTIL DRIER AIR CAN WORK INTO THE REGION BEHIND
A COLD FRONT.
&&
.PREV DISCUSSION... /ISSUED 310 PM CDT MON MAY 12 2014/
REST OF THIS AFTERNOON AND TONIGHT - CONFIDENCE...MEDIUM
ELONGATED LOW PRESSURE FROM ERN IA INTO WRN WI AREA WILL LIFT TO
NORTH OF LAKE SUPERIOR. PLENTY OF MOIST AND UNSTABLE AIR RETURNING.
SPC MESO CHARTS ARE SHOWING SOME VERY IMPRESSIVE PARAMETERS
ESPECIALLY INTO SC WI. SO HEIGHTENED CONCERN FOR ALL FORMS OF SEVERE
WEATHER AND THIS INCLUDES THE POTENTIAL FOR TORNADOGENESIS. OUTFLOW
BOUNDARY SETTING UP FAR SRN WI WILL ONLY ADD TO THAT CONCERN.
ISOLATED STORMS ALREADY FIRING ACRS NRN IL. 0-6KM SHEAR AND 0-1KM
SHEAR GETS A LITTLE BETTER MOVING FROM IL INTO WI. LATEST HRRR
SHOWING IA DEVELOPMENT SPREADS ACRS SRN WI LATE AFTN/ERLY EVE WITH
LESS CONFIDENCE LATER IN THE NIGHT WITH THE APPROACH OF THE COLD
FRONT. AIRMASS MAY BE PRETTY WORKED OVER BY THEN. TWO AREAS RECEIVED
DECENT RAINS...ONE BEING IN THE NW CWA NEAR THE DELLS AND THE OTHER
IN THE SE. WILL HOLD OFF ON FLASH FLOOD WATCH AS CONVECTION SHOULD
BE ON THE MOVE BUT ANY TRAINING ALONG THE OUTFLOW COULD CAUSE
PROBLEMS.
TUESDAY - CONFIDENCE...MEDIUM
LOW PRESSURE WILL CONTINUE TO LIFT NNE INTO CANADA WITH COLD FRONT
SHIFTING TO THE EAST. EXPECT SOME LINGERING SHRA IN ERN CWA DURG THE
MRNG HRS. UPPER FLOW IS STILL SOUTHWEST SO THIS WILL LIKELY CARRY
SOME WEAK DISTURBANCES ALONG AND AHEAD OF 850 FRONT TO MAINTAIN RAIN
CHANCES IN THE MORNING ACROSS THE SE 1/2. THEN WITH THE COLD
ADVECTION ON THE BACK SIDE OF THIS SYSTEM WE CAN TAKE ABOUT 10-15
DEGREES OFF THE 925 TEMPS. SO TURNING COOLER...LESS HUMID AND LIKELY
A GOOD DEAL OF CLOUD COVER TO CONTEND WITH. LLVL RH PROGS AND MOS
SKY COVER SUGGEST THIS... ESPECIALLY WITH THE INCOMING LOW LEVEL
COOL POOL AND MID LEVEL TROUGH AXIS STILL TO THE WEST.
TUESDAY NIGHT - CONFIDENCE...HIGH
A QUIET PERIOD AS DRY...COOLER AIR SETTLES INTO SOUTHERN WI. 85H
TEMPS FALL TO AROUND 0C OVERNIGHT. BOUNDARY LAYER MIXING WILL KEEP
THE LOWEST LEVELS STIRRED ENOUGH TO KEEP OVERNIGHT TEMPS MOSTLY 40
TO 45F.
WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE - MEDIUM.
UNCERTAINTY CREEPS IN LATER WEDNESDAY THROUGH THURSDAY FOR PRECIP
THREAT. SHORT TERM GUIDANCE IN GENERAL AGREEMENT ON CYCLOGENESIS
OCCURRING OVER SOUTHERN PLAINS LATER WEDNESDAY WITH STRENGTHENING
LOW PRESSURE TRACKING NORTHEAST THROUGH THE TN AND OH VALLEYS. MID-
LEVEL CIRCULATION TRACKING ALONG BAROCLINIC ZONE OVER IL MAY BRING
SOME -RA TO SOUTHEAST WI WED NGT INTO THU. HOWEVER LATEST CANADIAN
A LITTLE FARTHER EAST WITH THE BAROCLINIC ZONE. DUE TO
UNCERTAINTY...WL BUMP UP POPS TO HIGH CHANCE IN MY
SOUTHEAST...DROPPING OFF FAIRLY QUICKLY TO LOW/SLIGHT CHANCE AS
EXPECT A SHARP CUTOFF ACROSS SOUTHEAST WI. LOW LEVEL THERMAL
PROFILE FAVORS RAIN...HOWEVER IF SLIGHT ADDITIONAL COOLING WERE TO
TAKE PLACE...THEN COULD BE SOME SNOW MIXED IN WITH THE RAIN AT
TIMES.
THURSDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE - MEDIUM.
LOW MOVING NORTH FROM THE OH VALLEY ACROSS THE GTLAKES THU AND THU
NIGHT WILL TRANSITION TO STATIONARY UPPER LOW OVER THE REGION FOR
THE END OF THE WEEK...ON INTO THE WEEKEND. THIS WILL RESULT IN
CONTINUED PERIOD OF COLD NORTHWEST WINDS REINFORCING CHILLY AIR OVER
SRN WI INTO SATURDAY. THE UPPER LOW FINALLY STARTS TO BREAK DOWN
OVER THE WEEKEND...WHICH WOULD ALLOW MILDER AIR TO RETURN TO THE
AREA BEGINNING SUNDAY. OVERNIGHT LOWS EXPECTED TO DIP INTO THE 30S
SEVERAL NIGHTS. WL NEED TO WATCH NIGHT TIME CLOUD COVER AND THINK
ABOUT FROST POTENTIAL FOR THURSDAY NIGHT AND FRIDAY NIGHT.
AVIATION/00Z TAFS/...MAIN SHORT TERM CONCERN WILL BE CONVECTION
INTO THE EVENING HOURS. NEXT WAVE OF STORMS APPROACHING FROM IOWA
WILL ARRIVE LATER THIS AFTN/EVE. ISOLATED STORMS FIRING VCNTY
OUTFLOW BOUNDARY IN NRN IL. THESE MAY BECOME SVR. STORMS IN IA MOVG
INTO WI THIS EVE MAY BE SVR AS WELL. LATEST HRRR SUGGESTS LESS
ACTIVITY LATER IN THE NIGHT AS AIRMASS STABILIZES ONCE THIS SURGE
PASSES. HOWEVER WILL STILL KEEP TSRA CHANCES DUE TO APPROACHING
UPPER JET DYNAMICS AND SURFACE COLD FRONT DRAWING CLOSER. DENSE FOG
CONCERNS ARE NORTH OF TAF SITES.
MARINE...WILL RETAIN DENSE FOG ADVISORY THROUGH LATER IN THE NIGHT
FOR PORT WASHINGTON TO SHEBOYGAN AS THAT AREA ENTRENCHED IN THE
FOGGY CONDITIONS WITH COOL FLOW OFF THE LAKE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR
TUESDAY NIGHT THROUGH MONDAY...MBK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1041 AM CDT TUE MAY 13 2014
.UPDATE...
ISSUED AT 1040 AM CDT TUE MAY 13 2014
CLOUD COVER AND NW WINDS ADVECTING AN UNUSUALLY COLD AIRMASS FOR
MID MAY HAS PREVENTED MUCH WARMING SO FAR THIS MORNING. IN FACT
INDEPENDENCE HAS HELD STEADY AT 46 DEGREES SINCE 3 AM. EROSION OF
LOW CLOUDS WILL BE SLOWED BY HIGHER CLOUDS ABOVE STREAMING N-NE
EAST OF THE UPPER TROUGH AXIS. HAVE UPDATED THE FORECAST TO LOWER
BOTH HOURLY AND MAX TEMPERATURES FOR TODAY. LOOKING AT UPSTREAM
HIGHS YESTERDAY...IT WILL TAKE AT LEAST SOME LATE AFTERNOON SUN TO
REACH HIGHS THAT HAVE BEEN REVISED DOWNWARD TO A RANGE FROM THE
MID 50S NW TO NEAR 60 IN THE FAR SOUTH AND SOUTHWEST.
IF CLOUDS HOLD ON AS SUGGESTED BY THE LATEST RAP MODEL RH
FIELDS...HIGHS IN THE LOWER TO MID 50S MAY EVEN BE TOO OPTIMISTIC
AND WILL CONTINUE TO MONITOR FOR FURTHER DOWNWARD ADJUSTMENTS.
&&
.SYNOPSIS...
ISSUED AT 229 AM CDT TUE MAY 13 2014
A COLD FRONT EXTENDED FROM WESTERN WISCONSIN SOUTH THROUGH WEST
CENTRAL IL INTO EASTERN MISSOURI EARLY THIS MORNING. THE FRONT WAS
JUST EAST OF A DEEP UPPER TROF THAT EXTENDED FROM CENTRAL CANADA
THROUGH THE HIGH PLAINS INTO THE SOUTHERN ROCKIES. MOST OF THE
SHOWERS AND THUNDERSTORMS WERE NEAR AND AHEAD OF THE COLD FRONT
EARLY THIS MORNING. ALTHOUGH THERE WERE SOME PATCHY POST FRONTAL
SHOWERS NEAR AND EAST OF THE MISSISSIPPI RIVER. THESE SHOWERS WERE
COLLOCATED WITH A BAND OF MID LEVEL FGEN. COLD AIR ADVECTION BEHIND
THE FRONT HAS DROPPED TEMPERATURES IN THE UPPER 40S OVER PARTS
EASTERN IOWA WHILE MID 60S WERE STILL BEING REPORTED NEAR THE FRONT
IN WEST CENTRAL IL.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 229 AM CDT TUE MAY 13 2014
THE COLD FRONT WILL CONTINUE MOVING EAST AND SHOULD BE EAST OF THE
FORECAST AREA BY 12Z. THE UPPER TROF THOUGH WILL REMAIN TO THE
WEST...OVER THE PLAINS. LOW AND MID LEVEL DRYING WILL SHUTDOWN THE
PRECIP OVER THE AREA THIS MORNING WITH LOWER CLOUDS DISSIPATING AS
DRIER AIR OVERSPREADS THE REGION. WE SHOULD CONTINUE TO SEE HIGH CLOUDS
FEEDING NORTH OVER THE AREA THROUGH DAY WITH CONTINUED UPPER FLOW
FROM THE SOUTH OR SOUTHWEST AND WITH THE REGION IN THE RIGHT
ENTRANCE REGION OF AN H3 JET EAST OF THE TROF AXIS. EXPECT MOST OF
THE AREA WILL SEE AT LEAST SOME FILTERED SUN BY THIS AFTERNOON
WITH THE LOSS OF THE LOWER CLOUD DECKS. THE PARTIAL SUN WILL
OFFSET THE COLD ADVECTION TODAY ALLOWING TEMPERATURES TO REBOUND
INTO THE UPPER 50S NORTHWEST. THICKER CLOUD COVER TO THE EAST WILL
KEEP ALLOW FOR A MINIMAL RECOVERY WITH LOW 60S EXPECTED...AFTER
MORNING LOWS IN THE UPPER 50S.
TONIGHT THE NORTHWEST HAS THE BEST CHANCE OF SEEING BETTER
CONDITIONS FOR RADIATIONAL COOLING WITH THE HIGH CLOUDS THINNING AND/OR
MOVING EAST AND LIGHT WINDS. SINCE DEWPOINTS ARE PROGGED TO DROP
INTO THE MID 30S OVER THE NORTHWEST WENT WITH MIN TEMPS TONIGHT A
LITTLE UNDER THE COLDER GUIDANCE...IN THE UPPER 30S. THE REST OF
THE AREA SHOULD HAVE THICKER HIGH CLOUDINESS SO KEPT MINS IN THE
40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 229 AM CDT TUE MAY 13 2014
FORECAST FOCUS IN THE EXTENDED IS MAINLY ON TEMPERATURES...AS LARGE
UPPER LEVEL TROUGH TO REMAIN OVER THE CENTRAL CONUS THROUGH THE END
OF WEEK...RESULTING IN BELOW NORMAL TO WELL BELOW NORMAL
TEMPERATURES OVER THE AREA.
WEDNESDAY...DRY AND COOL CONDITIONS EXPECTED THROUGH MUCH OF THE DAY
AS A STRONG SHORTWAVE TROUGH OVER THE SOUTHERN PLAINS BEGINS TO LIFT
INTO THE OHIO RIVER VALLEY BY THURSDAY NIGHT. THIS WAVE DEVELOPS A
SURFACE LOW IN THE LOWER MISSISSIPPI VALLEY WHICH WILL ALLOW FOR
INCREASING PCPN CHANCES ACROSS THE EASTERN PORTIONS OF THE CWA
WEDNESDAY NIGHT. LATEST 00Z MODELS ARE IN DISAGREEMENT ON HOW FAST
THIS SYSTEM WILL PROGRESS EAST WITH THE NAM BEING THE FURTHEST WEST
SOLUTION. IN ANY CASE CHANCE POPS ARE IN THE FORECAST FOR NOW ACROSS
THE FAR EASTERN SECTIONS. HIGHS TO REACH THE UPPER 50S AND LOWER 60S
BY THE AFTERNOON.
THURSDAY-FRIDAY...MODELS IN MUCH BETTER AGREEMENT BRINGING A SHORTWAVE
DOWN OUT OF THE NORTHERN PLAINS ON THURSDAY. MODEL LOW LEVEL
MOISTURE AND FORCING PROGS SHOULD BE SUFFICIENT ENOUGH TO PRODUCE
SCATTERED SHOWERS OVER THE AREA ON THURSDAY. QPF AMOUNTS WILL LIKELY
BE LESS THAN A TENTH OF AN INCH. HIGH TEMPERATURES WILL MAINLY BE
IN THE 50S EACH DAY. ANOTHER SURGE OF COLDER AIR WILL MOVE INTO THE
REGION BEHIND THURSDAY/S SHORTWAVE. MODEL H85 TEMPS WILL BE DROPPING
CLOSE TO 0C THURSDAY NIGHT AND GOING NEGATIVE IN THE -4 TO -2C RANGE
BY 12Z FRIDAY. THIS IS AROUND 2 STANDARD DEVIATIONS BELOW NORMAL FOR
MID MAY. OVERNIGHT LOWS THURSDAY NIGHT/FRIDAY NIGHT WILL DROP INTO THE
UPPER 30S TO LOWER 40S. CLOUD COVER AND LIGHT WINDS SHOULD PREVENT
ANY FURTHER DROP IN TEMPERATURES...HOWEVER LATER SHIFTS WILL NEED TO
WATCH THIS PERIOD CLOSELY FOR THE POSSIBILITY FOR LOWER TEMPERATURES
AND FROST POTENTIAL.
THIS WEEKEND...DRY CONDITIONS ARE EXPECTED AS THE MODELS LIFT THE
UPPER TROUGH NORTHEAST INTO THE GREAT LAKES AND AN UPPER RIDGE
BUILDS INTO THE CENTRAL CONUS. THIS WILL RESULT IN BRINGING NEAR
NORMAL TEMPERATURES BACK TO THE AREA SATURDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 619 AM CDT TUE MAY 13 2014
A COLD FRONT OVER EASTERN ILLINOIS THIS MORNING WILL CONTINUE TO
MOVE EAST...ALLOWING A RIDGE OF HIGH PRESSURE TO BUILD FROM THE
CENTRAL HIGH PLAINS INTO MID MISSISSIPPI VALLEY. MOST OF TODAY
SHOULD BE DOMINATED BY MVFR CIGS INCREASING FROM AROUND 15HND
FT THIS MORNING TO 2 TO 3KFT BY THIS AFTERNOON. CLEARING OVER
WESTERN IA THIS MORNING WILL MOVE SLOWLY EAST AND SHOULD REACH
EASTERN IOWA AND NORTHWEST IL BY LATE THIS AFTERNOON. GUSTY
NORTHWEST WINDS TODAY WILL DIMINISH AFTER SUNSET. A FEW SHOWERS OR
SPRINKLES WILL BE POSSIBLE THIS MORNING.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...11
SYNOPSIS...DLF
SHORT TERM...DLF
LONG TERM...GROSS
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS DES MOINES IA
636 AM CDT TUE MAY 13 2014
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
ISSUED AT 332 AM CDT TUE MAY 13 2014
MAIN FORECAST CONCERN TODAY WAS WITH MAX TEMPS AND CLOUD COVER.
AREA OF LOW PRESSURE LOCATED OVER LAKE SUPERIOR WILL CONTINUE TO
DRAG NORTHEAST INTO ONTARIO TODAY. DECENT CAA WILL PERSISTS
THROUGHOUT THE DAY DUE TO PRESSURE GRADIENT AIDED BY INCREASING
MIXING DURING THE AFTERNOON. LOW LEVEL MOISTURE GRADUALLY ERODES
FROM SOUTHWEST TO CENTRAL IOWA AND SHOULD SEE CLOUD COVER THIN OUT
AND LIFT IN THIS FASHION DURING THE AFTERNOON. HOWEVER...A
SECONDARY LOBE OF MID-LEVEL THETA-E ADVECTION WRAPS AROUND THE
SURFACE LOW LATE IN THE DAY AND LOOKS TO REINFORCE THE CLOUD COVER
OVER NORTHERN IOWA. THE 13.05Z HRRR AND 13.03Z HOPWRF ARE IN FAIR
AGREEMENT WITH THE PREVIOUS THINKING OF CLOUD COVER TRENDS...BUT
THINKING ARE SLIGHTLY TOO QUICK IN ERODING. WENT SLIGHTLY BELOW
MOS GUIDANCE FOR MAX TEMPS TODAY WITH THE CLOUD COVER AND CAA.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 332 AM CDT TUE MAY 13 2014
AFTER A WARM AND ACTIVE PERIOD THE PAST WEEK...WE WILL TURN AROUND
AND GO BACK TO A RELATIVELY COOL AND MOSTLY QUIET PERIOD FOR THE
NEXT 4 TO 5 DAYS. THOUGH NOT RAIN FREE...CHANCES FOR ANY ORGANIZED
SEVERE WEATHER WILL BE SLIM TO NONE. WITH THE RECENT RAINFALL SOME
RIVERS ARE RISING NOW BUT REMAINING IN BANK. THE H500 LOW NOW
OVER SOUTHERN CANADA WILL WOBBLE NORTHEAST WEDNESDAY WITH A
SECONDARY VORT MAX DIGGING SOUTHEAST ON THE BACK SIDE OF THE
SYSTEM OVER THE NEXT TWO DAYS. THIS WILL RESULT IN ANOTHER COLD
FRONT AND COLD POOL DROPPING SOUTH INTO MN AND IOWA BY LATE
WEDNESDAY NIGHT AND THURSDAY. MEANWHILE...TONIGHT SHOULD REMAIN
GENERALLY CLEAR TO PARTLY CLOUDY AS A WEAK RIDGE OF HIGH PRESSURE
SETTLES INTO THE AREA. TEMPS WILL BE QUITE COOL WITH THICKNESS
DROPPING TO 540 NORTH TO ABOUT 546 SOUTH. LOWS SHOULD RANGE FROM
THE MID TO UPPER 30S NORTH TO THE LOWER 40S SOUTH. BY EARLY
WEDNESDAY A WEAK UPSTREAM WAVE OVER THE NORTHERN PLAINS WILL DROP
SOUTH TOWARD IOWA...BRIEFLY ENHANCING WESTERLY FLOW ALOFT AND
INCREASING WARM AIR ADVECTION THROUGH THE AFTERNOON HOURS. THIS
WILL LIKELY SPREAD A CLOUDS ACROSS THE REGION WITH A FEW SHOWERS
AND ISOLATED THUNDERSTORMS NORTHWEST BY AFTERNOON. TEMPS WILL
RESPOND AND REACH THE LOWER 60S NORTH TO THE MID 60S CENTRAL AND
WEST. AS THE WEAK SFC BOUNDARY DROPS SOUTH THROUGH THE AREA WED
NIGHT IN RESPONSE TO THE STRENGTHENING NW FLOW ALOFT...CLOUDS WILL
OVERSPREAD THE REGION WED NIGHT AND CONTINUE INTO THURSDAY. THE
H500 COLD POOL THURSDAY IS BEING HANDLED DIFFERENTLY BY THE
GEM/EURO MODEL VS THE GFS/NAM. THE GEM/EURO ARE STRONGER AND
ESSENTIALLY PRODUCE A CUTOFF LOW OVER THE GREAT LAKES WHILE THE
GFS/NAM ARE KEEPING A WEAKER...OPEN WAVE OVER THE AREA.
CLIMATOLOGY WOULD FAVOR THE COLDER...MORE CLOSED SOLUTION SO WILL
TREND TOWARD COLDER...CLOUDIER...AND MORE SHOWERY FOR THURSDAY. IN
FACT LAPSE RATES REMAIN STEEP ENOUGH WITH THE COLD POOL ON
THURSDAY TO PRODUCE LATE MORNING THROUGH AFTERNOON THUNDERSTORMS.
WITH FREEZING LEVELS AS LOW AS FORECAST...MAY SEE SOME SMALL
HAIL/SLEET OR VERY COLD RAIN WITH A FEW OF THE STORMS THURSDAY IF
DOWNDRAFTS BECOME STRONG ENOUGH. VERY LITTLE CHANGE IS EXPECTED
THROUGH FRIDAY WITH NW FLOW CONTINUING WITH THE H500 LOW IN THE
AREA. ADDITIONAL CHANCES FOR ISO THUNDER ARE AGAIN POSSIBLE FRIDAY
AFTERNOON AS DAYTIME HEATING INCREASES INSTABILITY. TEMPS THURSDAY
AND FRIDAY WILL STRUGGLE TO REACH THE MID 50S NORTH TO UPPER
50S/LOWER 60S SOUTH AS CLOUDS BUILD DURING THE DAYTIME HOURS. THE
UPPER LEVEL LOW WILL FINALLY PULL EAST BY SATURDAY WITH A
FLATTENING OF THE FLOW TO OUR WEST. THIS WILL ALLOW FOR WARM AIR
ADVECTION TO INCREASE ACROSS IOWA INTO THE WEEKEND. WITH A GREAT
LAKES HIGH STILL HOLDING ON SUNDAY MAINLY DRY CONDITIONS ARE
EXPECTED THROUGH THE WEEKEND. THOUGH UNCERTAINLY ON TIMING IS
INCREASING TOWARD THE END OF THE FORECAST...A LARGE SCALE TROUGH
WILL ENTER THE PACNW SUNDAY AND INCREASE THETAE ADVECTION ACROSS
THE PLAINS LATE ON SUNDAY INTO MONDAY. THIS SHOULD INCREASE TEMPS
AND CHANCES FOR THUNDER INTO MONDAY. TRENDS OF THE GEM/EURO
CONFIRM INCREASING MOISTURE BY THE END OF THE WEEKEND AND
ESPECIALLY ON MONDAY WITH MORE ORGANIZED CONVECTION. HIGHS SUNDAY
WILL REACH 70 WITH LOWER 70S ON MONDAY. NEXT WEEK LOOKS MUCH MORE
ACTIVE ONCE AGAIN.
&&
.AVIATION...13/12Z
ISSUED AT 627 AM CDT TUE MAY 13 2014
MVFR CIGS WILL PERSIST THROUGH MUCH OF THE MORNING HOURS BEFORE
MIXING HELPS TO LIFT THE CIGS BY AROUND MIDDAY. POTENTIAL MCW TO
ALO MVFR CIGS COULD LINGER FURTHER INTO THE AFTERNOON HOURS...SO
DID DELAY VFR CIGS ABOUT 3 HOURS. OTHERWISE...CAA PERSIST INTO
THE EVENING BEFORE HIGH MOVES OVERHEAD AND ALLOWS WINDS TO BECOME
LIGHT AND VARIABLE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...REV
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1045 AM EDT TUE MAY 13 2014
.UPDATE...
ISSUED AT 1040 AM EDT TUE MAY 13 2014
HOURLY GRIDS WERE UPDATED BASED ON RECENT OBSERVATION AND SATELLITE TRENDS.
THE REGION CONTINUES TO RESIDE ON THE WESTERN EDGE OF A RIDGE OF HIGH
PRESSURE CENTERED OFF THE SOUTHEAST US COAST. THE RIDGE AXIS WILL
SHIFT FURTHER TO THE NORTH AND EAST TODAY WITH HEIGHTS EXPECTED TO
LOWER A BIT BY THIS EVENING...AND THIS WILL ALLOW THE TROUGH OVER
THE MIDDLE OF THE COUNTRY TO GRADUALLY SHIFT EAST. SHORT TERM MODELS
SUCH AS THE HRRR SUGGEST ISOLATED TO PERHAPS SCATTERED CONVECTION
IMITATING OVER THE NORTHERN CUMBERLAND PLATEAU OF TN OR ACROSS THE
SOUTHERN PORTION OF THE DANIEL BOONE NF AND BIG SOUTH FORK NRRA
AROUND OR SHORTLY AFTERNOON NOON WITH FURTHER DEVELOPMENT EAST INTO
THE COALFIELDS/VA BORDER COUNTIES SHORTLY THEREAFTER. OUTFLOWS FROM
THIS PULSE TYPE CONVECTION SHOULD LEAD TO ANOTHER COUPLE GENERATIONS
OF ISOLATED CONVECTION THROUGH EARLY IN THE EVENING.
UPDATE ISSUED AT 655 AM EDT TUE MAY 13 2014
FORECAST IS ON TRACK THIS MORNING...SO NO UPDATE PLANNED AS OF RIGHT
NOW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 306 AM EDT TUE MAY 13 2014
STRONG RIDGING CONTINUES TO RESIDE OVER THE EAST COAST WITH A
BAROCLINIC ZONE LYING ACROSS THE CENTRAL PLAINS. EASTERN KENTUCKY
WILL CONTINUE TO REMAIN IN NO MANS LAND WITH RESPECT TO THESE TWO
SYSTEMS TODAY AND TONIGHT. THUS...IT LOOKS LIKE MORE OF THE SAME
TODAY WITH HIGHS SURGING INTO THE 80S. MUCH LIKE THE PAST FEW DAYS A
STRAY SHOWER OR THUNDERSTORM COULD DEVELOP JUST ABOUT ANYWHERE DURING
THE MID TO LATE AFTERNOON HOURS. AS INSTABILITY WANES THIS
EVENING...WE SHOULD SEE ANOTHER QUIET NIGHT WITH LOWS INTO THE UPPER
50S IN THE VALLEYS AND UPPER 60S ON THE RIDGES.
BY WEDNESDAY...THINGS WILL FINALLY START TURNING MORE ACTIVE TO OUR
WEST AS A SOUTHERN STREAM WAVE PHASES WITH A NORTHERN STREAM
WAVE...GENERATING A SURFACE LOW OVER ARKANSAS. STILL SOME UNCERTAINTY
ON HOW QUICKLY PRECIPITATION WILL GET ORGANIZED AHEAD OF THIS SYSTEM
AND SPREAD INTO EASTERN KENTUCKY. GENERALLY HAVE SLOWED DOWN THE
PROGRESSION OF HIGHER POPS INTO THE AREA ON WEDNESDAY...BUT MAY NEED
TO BE BACKED OFF A BIT MORE IF THE TRENDS OF A SLOWER PROGRESSION
CONTINUE. IN FACT...THINGS DON`T LOOK ALL THAT DIFFERENT THAN THE
PREVIOUS FEW DAYS WITH RESPECT TO LACK OF FORCING AND NO REAL
MECHANISM FOR GENERATING SHOWERS AND STORMS. THUS...CONFIDENCE IS NOT
HIGH ON PRECIPITATION CHANCES ON WEDNESDAY...SO WILL GENERALLY GO WITH
A GRADIENT IN POPS FROM WEST TO EAST WITH THE HIGHEST IN THE
BLUEGRASS...AND TRAILING OFF INTO SOUTHEAST KENTUCKY. CERTAINLY
POSSIBLE WEDNESDAY ENDS UP BEING DRIER FOR MOST...ESPECIALLY THOSE IN
THE EAST AND SOUTHEAST. SEVERE THREAT WEDNESDAY AFTERNOON IS HIGHLY
CONTINGENT ON ENOUGH INSTABILITY IF CLOUDS CAN HOLD OFF THROUGH THE
DAY. BIGGEST THREAT WILL BE STRONG WINDS AND HAIL IF THE INSTABILITY
PANS OUT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 306 AM EDT TUE MAY 13 2014
THE MODELS ARE ONLY IN FAIR AGREEMENT ALOFT AT THE BEGINNING OF THE
EXTENDED AS THEY ALL DEPICT A DEVELOPING FULL LATITUDE TROUGH WITH
TWIN POLES OF ENERGY DRIVING ITS FORMATION. THE SOUTHERN ENERGY
CLUSTER IS MOVING EAST THROUGH THE SOUTHERN PLAINS AT 00Z THURSDAY
WHILE THE NORTHERN STREAM ONE IS CUTTING INTO THE UPPER MIDWEST. THE
NAM IS SLOWEST...DEEPER...AND FURTHEST SOUTH WITH THE SOUTHERN NODE
AND IS THUS DISCOUNTED AS AN OUTLIER. MEANWHILE...THE ECMWF APPEARS
TO BE A GOOD COMPROMISE BETWEEN THE STRONGER GEM AND WEAKER GFS
HERE. FOR THE NORTHERN PORTION OF THE TROUGH...THE GEM AND GFS ARE
QUITE SIMILAR. THE SOUTHERN WAVE FURTHER AMPLIFIES THAT NIGHT...
PLOWING INTO THE TENNESSEE VALLEY AS IT DRAGS NORTHERN ENERGY SOUTH
TO FORM A DEEP CLOSED LOW OVER THE UPPER MIDWEST BY MIDDAY THURSDAY.
THE GEM REMAINS THE STRONGEST WITH THE BROAD CLOSED LOW TAKING SHAPE
WHILE THE ECMWF HOLDS THE MIDDLE GROUND COMPARED WITH THE WEAKER
GFS. THE CORE OF THE SOUTHERN ENERGY THEN RIDES NORTH INTO THE GREAT
LAKES AS IT IS ABSORBED INTO THE BURGEONING MIDWEST LOW. A WEAKER
REMNANT OF THIS ENERGY DOES EASE THROUGH EAST KENTUCKY THURSDAY
NIGHT JUST AS THE HEIGHT FALLS FROM THE DOMINANT LOW SPREADS OVER
THIS PART OF THE STATE. THIS LARGE LOW THEN SLOWLY PIVOTS NORTHEAST
WITH ITS CORE DEEPENING NORTH OF THE GREAT LAKES IN THE ECMWF BY
FRIDAY NIGHT BUT REMAINING FAIRLY STABLE IN THE OTHERS. EVEN THE
ECMWF STARTS TO FILL THE LOW BY SATURDAY NIGHT AS THE PATTERN
FURTHER DEAMPLIFIES OVER THE OHIO VALLEY...THOUGH SIGNIFICANT MODEL
DIFFERENCES REMAIN WITH THE DEPARTING TROUGH...MAINLY INVOLVING THE
SLOWER EXIT SEEN IN THE GFS AND GEM. CYCLONIC FLOW AND HEIGHTS
SLIGHTLY BELOW NORMAL WILL REMAIN OVER THE AREA INTO MONDAY MORNING
IN ALL THE MODELS...THOUGH THE GFS IS A NOTABLE STANDOUT ON THE MORE
AMPLIFIED SIDE HERE. BY MONDAY AFTERNOON...THOUGH...HEIGHTS SHOULD
BE ON THE RISE AGAIN IN THE FACE OF AN APPROACHING RIDGE FROM THE
PLAINS. WILL FAVOR THE ECMWF SOLUTION THROUGH FRIDAY NIGHT BEFORE A
GENERAL MODEL BLEND IS PREFERRED FOR THE REMAINDER OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE A SFC WAVE DEVELOPING ON A COLD FRONT
JUST OF THE WEST OF THE AREA ON WEDNESDAY. THIS LOW PRESSURE WAVE
WILL LIFT THROUGH EAST KENTUCKY WEDNESDAY NIGHT INTO THURSDAY
MORNING WITH THE BEST CHANCES FOR SOAKING RAINS DURING THE FORECAST.
THUNDERSTORMS WILL BE POSSIBLE ESPECIALLY EARLY WEDNESDAY NIGHT
WHILE SOME DAYTIME INSTABILITY REMAINS. IN FACT...SEVERE WEATHER
CANNOT BE RULED OUT AS CYCLOGENESIS TAKES PLACE THROUGH CENTRAL
KENTUCKY COMPLETE WITH UPPER LEVEL SUPPORT AND DECENT WIND SHEAR
THROUGH EAST KENTUCKY INTO THE EVENING. DO EXPECT ONGOING CONVECTION
AND ITS EVOLUTION INTO THE EVENING TO BE THE PRIMARILY DRIVING
FACTOR IN OUR SEVERE...AND EXCESSIVE RAIN...THREATS THROUGH THURSDAY
MORNING. FOR NOW...WILL CONTINUE TO HIGHLIGHT THESE CONCERNS IN THE
HWO. MUCH COLDER AIR WILL THEN POUR INTO EAST KENTUCKY IN THE WAKE
OF THE SYSTEM MOVING INTO THE MID ATLANTIC STATES. THERE WILL BE
A...MAINLY DIURNALLY DRIVEN...CHANCE FOR SHOWERS INTO THE WEEKEND
BENEATH THE LARGE UPPER LOW. CONVECTION CANNOT BE RULED OUT FOR
SUNDAY AND MONDAY AS A DEVELOPING WARM FRONT WILL ATTEMPT TO MOVE
NORTH INTO EAST KENTUCKY...BUT MORE LIKELY HIGH PRESSURE WILL KEEP
IT SUPPRESSED TO THE SOUTH THROUGH THE REMAINDER OF THE EXTENDED.
THE CR GRID LOAD CAME IN PRETTY GOOD FOR THE BULK OF THE EXTENDED...
THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION
EARLY ON AND ALSO TO BETTER EMPHASIZE THE DIURNAL NATURE OF THE
SHOWERS FOR THE END OF THE WEEK AND START OF THE WEEKEND. DID ALSO
FINE TUNE SOME LOW TEMP GRIDS LATE IN THE FORECAST TO BETTER CAPTURE
SOME ENHANCED RIDGE AND VALLEY DETAILS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 655 AM EDT TUE MAY 13 2014
VFR CONDITIONS WILL LIKELY PERSIST THROUGH THE TAF FORECAST PERIOD AT
THE TAF SITES. SCATTERED CU WILL DEVELOP AGAIN TODAY...WITH A STRAY
SHOWER OR STORM POSSIBLE THIS AFTERNOON. HOWEVER...LIKE YESTERDAY...
CONFIDENCE IS SMALL FOR ANYTHING AFFECTING THE TAF STIES...SO WILL
LEAVE OUT THE MENTION OF SHOWERS AND STORMS. PATCHY VALLEY FOG WILL
FORM AGAIN LATER TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1059 AM EDT TUE MAY 13 2014
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OFFSHORE THROUGH THE REST OF THE WEEK.
A BACKDOOR COLD FRONT OVER NEW JERSEY WILL MOVE SOUTHWESTWARD INTO
THE AREA LATE THIS AFTERNOON AND TONIGHT. ANOTHER COLD FRONT
EXTENDING FROM WISCONSIN TO TEXAS WILL TRACK SLOWLY EAST...MOVING
INTO THE MID ATLANTIC STATES THURSDAY AND FRIDAY. HIGH PRESSURE IS
EXPECTED TO RETURN TO THE MID ATLANTIC THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST WATER VAPOR IMAGERY AND 12Z RAOBS INDICATE THE UPPER RIDGE IS
OVER THE MID-ATLANTIC STATES THIS MRNG WITH THE RIDGE AXIS NEAR THE
WRN HIGHLANDS. THE POSITION OF THE RIDGE WILL KEEP THE COUPLE OF
REMNANT MESOSCALE CONVECTIVE SYSTEMS THAT ARE TRACKING AROUND THE
PERIPHERY OF THE RIDGE THIS MRNG AWAY FROM OUR CWA. THIS WILL GIVE
WAY TO SUNNY SKIES ACROSS THE FORECAST AREA UNTIL A CU FIELD
DEVELOPS THIS AFTN. THE ONE EXCEPTION TO THE MRNG SUNSHINE WILL BE
IN NORTH-CENTRAL MD WHERE DEBRIS CLOUDS FROM AN MCS IS MOVING THRU.
HIPRES CENTERED OVER THE GULF OF MAINE WILL BUILD SOUTHWESTWARD INTO
NORTHEASTERN MD THIS AFTN. WINDS WILL BACK OUT OF THE EAST IN
ASSOCIATION WITH PRESSURE RISES...ALLOWING FOR THE MARINE LAYER TO
ADVECT INLAND. THE LEADING EDGE OF THIS COOLER MARINE AIR IS MARKED
BY A BACKDOOR COLD FRONT...WHICH HAD PUSHED SOUTHWESTWARD TOWARD THE
WRN SUBURBS OF PHILLY AS OF 14Z. THE LATEST RAP HAS THIS BOUNDARY
MOVING THRU THE GREATER BALTIMORE METRO DURING THE MID TO LATE AFTN.
HAD SUPPORT FROM THE 12Z IAD RAOB TO INCREASE AFTN TEMPS 3-5 DEGREES
ACROSS MOST LOCATIONS UNDER STRONG DAYTIME HEATING. MRNG UPDATE TO
THE FCST NOW REFLECTS MAX TEMPS IN THE LOWER 90S ACROSS MAJORITY OF
THE CWA. COOLER TEMPS ARE EXPECTED NEAR THE BAY DUE TO ONSHORE FLOW
DEVELOPING WITH BACKDOOR FROPA.
AN ENSEMBLE OF THE LATEST NEAR-TERM HIRES MODEL GUIDANCE PROVIDES
SUPPORT FOR CONVECTIVE INITIATION DURING THE FIRST HALF OF THE AFTN
ACROSS THE HIGHER TERRAIN. CONVERGENCE ALONG THE BACKDOOR BOUNDARY
MAY ALSO PROVIDE THE FOCUS FOR SHOWERS AND STORMS IN THE NWRN
SUBURBS OF DC/BALTIMORE. KEPT POPS IN CHANCE (SCT COVERAGE) WITH A
LACK OF ORGANIZED SYNOPTIC SCALE LIFT. A MODIFIED 12Z IAD RAOB
INDICATES THE POTENTIAL FOR MLCAPE BETWEEN 1500-2000 J/KG OF CAPE
ASSUMING FULL HEATING. HAVE ADDED THE THREAT OF LOCALLY DAMAGING
WINDS AS THE POTENTIAL FOR DAMAGING WET MICROBURSTS INCREASES WITH
THE ARRIVAL OF MID-LVL DRY AIR THIS AFTN. THE MODE WOULD BE PULSE
SEVERE GIVEN HOW WEAK SHEAR PROFILES WILL BE. THERE IS ALSO A
CONCERN FOR LOCALLY HEAVY RAINFALL AS STORM MOTION WILL BE UNDER 10
KT UNDERNEATH THE UPPER RIDGE. ADDED THE POTENTIAL FOR LOCALIZED
FLASH FLOODING ACROSS THE HIGHER TERRAIN.
SHOWERS AND STORMS SHOULD DIMINISH FROM E TO W THIS EVE WITH THE
LOSS OF DAYTIME HEATING AS COOLER STABLE AIR WEDGES IN BEHIND THE
BACKDOOR COLD FRONT. IF AIRMASS IN WARM SECTOR IS NOT WORKED OVER
FROM EARLIER CONVECTION...A FEW SHOWERS AND STORMS MAY CONTINUE
INTO THE OVERNIGHT IN THE MTS. STRATUS AND FOG EXPECTED TO DEVELOP
TNGT EAST OF THE BLUE RIDGE IN WAKE OF FROPA.
&&
.SHORT TERM /WEDNESDAY/...
BY WED THE UPR RDG WL BE MOVG OFF THE CST AND CLDS WL BE INCRSG
HERALDING THE APRCH OF THE SYSTEM WHICH WL BE CONTROLLING THE AREA
WX FOR THE FINAL 2 DAYS OF THE WORKWK. HIGH TEMPS XPCTD TO DROP
BACK INTO THE 70S. DURG THE DAY PCPN CHCS WL BE INCRSG FM W TO E.
SVR THREAT WL RMN LOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AN ANOMALOUSLY DEEP UPPER TROUGH WILL MAKE A SECONDARY PUSH DOWN
INTO THE SOUTHEAST LATE THIS WEEK. A FEATURE THIS STRONG MOVING THIS
FAR SOUTH NEARLY ALWAYS WILL TAP INTO AMPLE GULF MOISTURE. FROM LATE
WED INTO THU...THE UPPER VORT MAX WILL SLIDING OVER THE OZARKS INTO
THE MID MS VLY...W/ A LARGE SECTION OF THE DEEP SOUTH UNDER BUILDING
AREAS OF PRECIP. INITIALLY POORLY ORGANIZED AS THE DYNAMICS ARE
SETTING UP...WE`LL BEGIN TO SEE POCKETS OF HEAVY RAIN MOVE UP THE
SRN/CNTRL APLCNS DURING THE DAYTIME HRS THU. THIS WILL ACTUALLY DRY
OUT OUR IMMEDIATE AREA...W/ ONLY A FEW HANDFULS OF WEAK AND
SCATTERED SHOWERS DRIFTING AROUND THE REGION.
A WARM FRONT WILL BE SLIDING ACROSS THE AREA EARLY THU...STARTING TO
MIX-OUT THE WEDGE OVER NERN MD/DC METRO AREA FROM WED. THE FRONT
WILL NEED TO MOVE THRU FOR ANY AMOUNT OF INSTABILITY TO DEVELOP OVER
THE DC/BALT METRO AND I-95 CORRIDOR. SKIES WILL REMAIN OVERCAST FOR
THE REGION ON THU...BUT THAT WON`T PREVENT SFC TEMPS FROM CLIMBING
WELL INTO THE 70S AND EVEN L80S BY MID AFTN. S-SELY WINDS WILL BE
BREEZY INTO THE 15-25MPH RANGE AND EVEN GUSTIER THRU THE LOW LEVELS
OF THE ATMOS. THE STRONG LOW LEVEL FLOW WILL ADD THE OTHER ELEMENT
OF CONVECTIVE POTENTIAL - WHEREAS THE INSTABILITY WILL BE LACKING
THROUGHOUT THE BUILD-UP AND PASSAGE OF THE INCOMING UPPER TROUGH.
FROM LATE THU INTO MIDDAY FRI...WAVES OF MODERATE TO HEAVY RAIN WILL
APPROACH AND MOVE ACROSS THE REGION. EMBEDDED AREAS OF HEAVIER
ACTIVITY LIKELY ELEVATED CONVECTION WILL ADD THE ELEMENT OF MIXING
DOWN ISOLATED GUSTY TO POSSIBLY DAMAGING WINDS - ESPEC ON FRI AFTN.
THE MAIN CONCERN HOWEVER IS FLOODING FROM THE 1-3 INCHES OF EXPECTED
QPF...LOCALLY HIGHER. THE SFC SYSTEM NOT QUITE IN CONSENSUS AMONGST
THE MED RANGE MEMBERS...BUT A TREND TOWARD THE SFC LOW LOOKS TO
TRACK NEAR THE AREA DURING THE FIRST-HALF OF THE DAY ON FRI. THE
TRACK OF THE STRONGER OF THE SFC LOWS WILL DETERMINE THE CONVECTIVE
POTENTIAL FOR THE AREA. THE MORE OF OUR AREA THAT IS SOUTH AND EAST
OF THE LOW - THE BETTER THE POTENTIAL FOR INSTABILITY AND STRONGER
CONVECTION. THE FURTHER SOUTH THE LOW IS RELATIVE TO OUR
REGION...THE MORE GENERAL STRATIFORM AND MAINLY WIDESPREAD MODERATE
RAIN.
THE UPPER TROUGH POWERING THE SYSTEM WILL BEGIN TO MAKE A NEGATIVE
TILT LATE FRI...ADDING MORE POTENCY TO THE OVERALL SYSTEM BUT ALSO
ACCELERATING THE MOISTURE AXIS TOWARD THE ERN SEABOARD DURING THE
LATE NIGHT HRS. CONDITIONS WILL DRY OUT QUICKLY AS THE WAVE OF
SUBSIDENCE AND COOLER AIR PUSHES INTO THE BACK SIDE OF THE PRECIP.
AN UPPER LOW DRIFTING DOWN FROM SOUTH OF THE HUDSON BAY AROUND WILL
ROTATE AROUND THE GREAT LAKES INTO THE COMING WEEKEND...KEEPING OUR
AREA QUITE COOL AND RELATIVELY DRY. THE "WEATHER" FROM THIS FEATURE
WILL MAKE IT FEEL MORE LIKE MARCH THAN MAY...EVEN THOUGH AVG TEMPS
FOR MID-MAY ARE IN THE M70S. A SLOW MOVING AND COLD UPPER LOW TAKING
A FEW DAYS TO EXIT THE NORTHEAST WILL KEEP US IN THIS PATTERN WELL
INTO NEXT WEEK. IT MAY BE SEVERAL MORE DAYS BEFORE WE GET ANYWHERE
CLOSE TO 80 DEG OR MORE...BASED ON THE PATTERN SETTING UP FOR NEXT
WEEK.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
PREDOMINATELY VFR THRU SUNSET. HOWEVER WITH SCT SHRA AND TSRA
EXPECTED TO DEVELOP THIS AFTN/EVE...LOCAL/BRIEF VSBY RESTRICTIONS
AND STRONG WINDS POSSIBLE. BEST CHANCE TO SEE SHRA/TSRA WILL BE IN
VC OF MRB. WINDS BECOME ELY LATE TDA INTO TNGT BEHIND A BACKDOOR
COLD FRONT. IFR CIGS WITH LOW CLOUDS LIKELY TO MOVE IN BETWEEN
03-06Z BWI/MTN/DCA AND POSSIBLY BETWEEN 06-10Z AT IAD/MRB. PATCHY
FOG ALSO POSSIBLE BUT GNRLY MAY IS NOT A BIG FOG MONTH
CLIMATOLOGICALLY.
CNVCTN WL AGN BE PSBL WED AHD OF A CD FNT CURRENTLY TRIGGERING
TSTMS FM WI TO NRN MEX. THIS WL BECOME A BIGGER PLAYER FOR E CST
AVIATION THU AND FRI.
ANOTHER STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE REGION FROM
LATE THU INTO FRI. MAINLY PERIODS OF HEAVY RAIN WOULD BE THE
CONCERN...W/ BREEZY SFC WINDS BUT EVEN STRONGER LOW LEVEL FLOW - A
GOOD 30-50KT IN THE BOUNDARY LAYER OUT AHEAD OF THE SFC LOW LATE THU
INTO EARLY FRI. A COLD FRONT WILL PUSH THE PRECIP AND ANY EMBEDDED
TSTMS OFF THE COAST BY LATE FRI...W/ COOLER AND DRIER AIR BEING
USHERED IN FOR THE COMING WEEKEND.
&&
.MARINE...
HIPRES CENTERED OVER THE GULF OF MAINE WILL BUILD SWWD TOWARD THE
WATERS THIS AFTN AND TNGT...RESULTING IN WINDS BACKING FROM THE
EAST DURING THIS TIME. HAVE ISSUED A SCA FOR THE CHSPK BAY ZONES
AND LWR SRN MD FOR THIS EVE. A 2-4 HR PRESSURE SURGE HAS THE
POTENTIAL FOR PRODUCE SCA CONDITIONS BEHIND A BACKDOOR COLD FRONT
THIS EVE. UPSTREAM OBSERVATIONS IN NEW ENGLAND/NJ HAVE SHOWED THIS
HAPPENING IN WAKE OF FROPA.
A POTENT UPPER LEVEL TROUGH WILL GRADUALLY MOVE TOWARD THE REGION
FROM WED INTO THU...SPREADING PRECIP ALONG THE APLCNS BUT KEEPING
THE BAY/COAST RELATIVELY DRY UNTIL LATE THU. SFC WINDS HOWEVER WILL
START PUSHING WELL INTO SCA RANGE FROM EARLY THU ONWARD...UNTIL THE
EVENTUAL PASSAGE OF A COLD FRONT FRI EVE. GUSTY SLY WINDS WILL
CHANNEL UP THE MAIN STEM OF THE MD BAY...ALONG W/ THE PASSAGE OF
MODERATE TO HEAVY SHOWERS AND ISOLATED TSTMS FROM LATE THU INTO FRI
EVE.
BEHIND THE FRONT...WINDS WILL DROP OFF TO A LIGHT W/NW BREEZE THRU
THE WEEKEND.
&&
.TIDES/COASTAL FLOODING...
TIDAL SITES CURRENTLY NEAR ASTRONOMICAL TIDE ALONG THE WRN SHORE
OF THE CHSPK BAY AND TIDAL POTOMAC RIVER. POSITIVE TIDAL
ANOMALIES ARE EXPECTED TO DEVELOP TUE NGT AND WED AS THE ARRIVAL
OF A BACKDOOR COLD FRONT MARKS THE ONSET OF ONSHORE FLOW. MINOR
COASTAL FLOODING MAY DEVELOP LATE IN THE WEEK WHEN THESE POSITIVE
ANOMALIES INCREASE UNDER STRENGTHENING SLY FLOW AHEAD OF A SLOW-
MOVING COLD FRONT. ASTRONOMICAL TIDES WILL ALREADY BE HIGH WITH A
FULL MOON THIS WEEK.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR ANZ530>534-537>543.
&&
$$
UPDATE...JRK
PREV DISC...WOODY!/GMS/JRK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1105 AM EDT TUE MAY 13 2014
LATEST UPDATE...
UPDATE/MARINE
.SYNOPSIS...
ISSUED AT 308 AM EDT TUE MAY 13 2014
A COLD FRONT WILL PUSH EASTWARD THROUGH MICHIGAN TODAY TRIGGERING
SHOWERS AND THUNDERSTORMS. AN AREA OF HIGH PRESSURE WILL MOVE IN
FOR TUESDAY INTO EARLY WEDNESDAY DIMINISHING MOST OF THE
PRECIPITATION. A WAVE OF LOW PRESSURE WILL ARRIVE FOR WEDNESDAY
NIGHT WITH WET WEATHER EXPECTED.
&&
.UPDATE...
ISSUED AT 1105 AM EDT TUE MAY 13 2014
SHORT WINDOW OF OPPORTUNITY FOR STRONGER STORMS TO DEVELOP EXISTS
FROM LATE THIS MORNING THROUGH MID AFTERNOON PRIMARY EAST OF I-69
INCLUDING JXN.
THE FIRST SIGN OF NEW/DIURNAL CONVECTIVE DEVELOPMENT IS STARTING
TO SHOW UP AS A NARROW LINE OF SHOWERS OVER INDIANA AROUND KLAF.
THIS ACTIVITY SHOULD INCREASE IN INTENSITY AS IT HEADS NE TOWARD
JXN INTO AN AREA OF SUNSHINE WITH SB CAPES ALREADY AROUND 1500
J/KG. THE LINE WILL NEED TO BE MONITORED OVER THE NEXT FEW HOURS
FOR POSSIBLE SVR WX.
OTHERWISE MOSTLY CLOUDY SKIES OVER THE REST OF THE CWFA TODAY WITH
SCATTERED SHOWERS AND ISOLATED STORMS AS THE COLD FRONT PRESSES
EAST THROUGH THE AREA. THE FRONT WAS CROSSING LK MI AT MID MORNING
AND THE LATEST RUC GUIDANCE HAS IT CLEARING THE CWFA BY 20Z WITH
WESTERLY LOW LEVEL FLOW DEVELOPING AND GRADUALLY LOWERING SFC DEW
PTS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 308 AM EDT TUE MAY 13 2014
THE MAIN CHALLENGE IN THE SHORT TERM DEALS WITH THE RISK FOR
SEVERE WEATHER TODAY ALONG WITH THE POTENTIAL FOR RAIN WEDNESDAY
NIGHT.
LOOKS LIKE THE COMBINATION OF STRONGER DEEP LAYER SHEAR AND
INSTABILITY WILL OFFER A RISK FOR SOME SEVERE WEATHER INTO THIS
AFTERNOON. THE MOST UNSTABLE AIRMASS IS SHOWN TO DEVELOP EARLY TO
MID AFTERNOON AROUND JACKSON TO LANSING BEFORE THE COLD FRONT
PUSHES THROUGH. THUS THOSE LOCATIONS STAND THE GREATEST POTENTIAL.
THE MORNING CONVECTION COULD ALSO BE STRONG...GIVEN MU CAPES OVER
1500 J/KG...BUT THE SHEAR IS CURRENTLY WEAK. THE MAIN RISKS FOR
SEVERE WEATHER WOULD BE HAIL AND DAMAGING WINDS WITH TORNADOES A
LESS RISK. WILL CERTAINLY NEED TO MONITOR TRENDS CLOSELY.
INCREASED POPS FOR WED NIGHT. DECENT LOOKING WAVE OF LOW PRESSURE
LIFTS UP FROM THE LOWER MS VALLEY. COUPLED UPPER JET WILL HAVE
GULF MOISTURE TO WORK WITH PROVIDING WIDESPREAD RAIN. I INCREASED
POPS CONSIDERABLY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 308 AM EDT TUE MAY 13 2014
UPPER TROUGH REMAINS OVER THE GREAT LAKES REGION INTO FRIDAY.
THIS WILL ALLOW FOR A FEW SHOWERS...BUT WIDESPREAD HEAVY RAIN IS
NOT FORECASTED AT THIS TIME. THE RISK FOR SHOWERS WILL DECREASE
INTO SUNDAY AS UPPER LEVEL RIDGING TRIES TO BUILD IN. OVERALL IT
LOOKS LIKE WITH A LOW LEVEL THERMAL TROUGH IN PLACE INTO THE
WEEKEND...WE WILL END UP WITH COOLER THAN NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 730 AM EDT TUE MAY 13 2014
IFR AND LOWER CONDITIONS PREVAIL ALONG THE LAKESHORE THIS MORNING
AS FOG HAS DEVELOPED. THE SOUTHWEST TO WEST FLOW WILL DRAW SOME OF
THESE LOWER CLOUDS INLAND...IMPACTING WESTERN TAF SITES. RAIN
MOVING IN FROM THE SOUTHWEST MAY HAVE EMBEDDED THUNDERSTORMS.
AFTERNOON THUNDERSTORMS COULD IMPACT MAINLY INLAND TAF SITES AS
THE COLD FRONT PUSHES THROUGH. VFR WEATHER RETURNS BY TONIGHT.
&&
.MARINE...
ISSUED AT 1105 AM EDT TUE MAY 13 2014
MARINE WEB CAMS THIS MORNING REVEAL DENSE FOG AT HOLLAND... GRAND
HAVEN AND MKG. NOT QUITE SURE HOW EXTENSIVE THE DENSE FOG IS SINCE
HIGHER CLOUDS ARE MASKING THE STRATUS ON VSBL SATELLITE. CONSIDERED
A MARINE FOG ADVISORY BUT WILL HOLD OFF AND JUST CARRY AREAS OF
DENSE FOG THROUGH THE AFTERNOON. THE SFC FRONT WILL BE MOVING
THROUGH SOON LEADING TO LOWERING SFC DEW PTS WHICH SHOULD HELP
IMPROVE VISIBILITIES AT THE LAKESHORE AS THE DAY WEARS ON.
&&
.HYDROLOGY...
ISSUED AT 308 AM EDT TUE MAY 13 2014
HEAVY RAIN IS A RISK TODAY AND WEDNESDAY NIGHT. PWAT VALUES WILL
TOP 1.5 INCHES TODAY AND POSSIBLY WED NIGHT. LCLS WILL BE LOW
TODAY...AND COULD ALLOW FOR EFFICIENT RAINFALL. LOCAL AMOUNTS OVER
AN INCH ARE LIKELY TODAY. AS FOR WIDESPREAD VALUES OVER 2
INCHES...A SMALL RISK EXISTS...BUT CURRENTLY THAT RISK LOOKS LOWS.
AM THINKING MOST LOCATIONS WILL SEE OVER A HALF INCH OF RAIN WED
NIGHT GIVEN THE PASSAGE OF THE LOW PRESSURE SYSTEM THAT WILL
CONTAIN GULF MOISTURE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...MJS
AVIATION...MJS
HYDROLOGY...MJS
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1053 AM EDT TUE MAY 13 2014
.UPDATE...
RECENT PRESENTATION OF WATER VAPOR/VISIBLE IMAGERY AND TRENDS IN
OBSERVATIONS LEAVE EXPECTATIONS LARGELY UNCHANGED FOR A WINDOW FROM
MID AFTERNOON INTO THE EVENING FOR THE POSSIBILITY OF STRONGER
CONVECTIVE DEVELOPMENT. IN FACT...SOME LONGER RESIDENCE TIME OF
NEARLY FULL INSOLATION SOUTHEAST OF AN OWOSSO TO BAD AXE LINE
NETTING A PROGRESSIVE SURFACE TEMPERATURE RESPONSE. UPDATE ALREADY
OUT TO ADDRESS THIS WITH READINGS NOW EXPECTED TO LAND SOLIDLY IN
THE LOWER AND MIDDLE 80S THROUGHOUT THIS CORRIDOR. MODIFIED PARCEL
TAKEN WITH A T/TD OF 83/67 YIELDS SBCAPE ON THE ORDER OF
1500-1800 J/KG BY 18-20Z. UNDER THE BACKGROUND OF THIS MODIFYING
THERMODYNAMIC PROFILE...ENVIRONMENT CERTAINLY LOOKING SUPPORTIVE OF
MORE SUBSTANTIVE UPDRAFT STRENGTH. RECENT RUC ANALYSIS PAIRED WITH
WATER VAPOR AND LATEST HI RES SOLUTIONS SUGGEST CONVECTIVE
INITIATION WILL TEND TO ANCHOR ON SOME COMBINATION OF AN INBOUND
REMNANT MCV/PERTURBATION NOW EJECTING NORTHEAST OUT OF THE ARKANSAS/
MISSOURI BOOTHEEL AND A LEAD PRE-FRONTAL TROUGH AXIS. THE TROUGH
MAY BE HELPING SUSTAIN THE LIGHT RETURNS AND CLOUD DEBRIS
CURRENTLY STREAMING FROM SOUTHWEST LOWER MI INTO THE TRI-CITIES
AT THE MOMENT. THE DEEP LAYER LARGELY UNIDIRECTIONAL WIND FIELD
WILL BE IMPROVING WITH TIME...A NOTED UPTICK WITHIN THE 800-700 MB
LAYER BY LATE AFTERNOON SEEMINGLY SUPPLYING ADEQUATE ENOUGH SHEAR
TO SUSTAIN ORGANIZED STRUCTURES WITHIN THIS MODULATING PRE-FRONTAL
WARM SECTOR. THIS CONTINUES TO POINT TOWARD AT THE VERY LEAST A
MARGINAL RISK FOR STRONG WIND GUSTS...WITH A PLAUSIBLE SCENARIO
FOR A GREATER COVERAGE IN LIGHT OF ERODING CONCERNS OVER POTENTIAL
BOUNDARY LAYER HEATING. HEAVY RAINFALL ALSO A POTENTIAL ISSUE
GIVEN THE ELEVATED PWAT VALUES...PARTICULARLY HEADING INTO THE
EVENING AS THE FORWARD PROPAGATION OF THE INBOUND FRONTAL SLOPE
SLOWS WITH TIME.
&&
.AVIATION...ISSUED 700 AM EDT TUE MAY 13 2014
//DISCUSSION...
BUILDING INSTABILITY TODAY IN ADVANCE OF A SLOW MOVING COLD FRONT
WILL TRIGGER MORE SHOWERS AND THUNDERSTORMS. THE COLD FRONT IS
FORECAST TO TRACK ACROSS THE SE MI TERMINALS BETWEEN 21Z AND 02Z.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE DURING THIS PERIOD.
SHALLOW POST FRONTAL COLD AIR ADVECTION INTO THE MOISTURE LADEN
AIRMASS WILL CAUSE MVFR AND POSSIBLY SOME IFR POST FRONTAL STRATUS
WHICH MAY PERSIST WELL INTO THE NIGHT. THE EXPECTATION FOR A LARGE
AREA OF POST FRONTAL RAINFALL WILL ALSO AID IN MOISTENING THE LOW
LEVELS TONIGHT.
FOR DTW...CURRENT OBSERVATIONS SUGGEST THERE WILL BE A GOOD
OPPORTUNITY FOR INSTABILITY TO BUILD OVER METRO DETROIT INTO THE
AFTERNOON. GIVEN THE LATER TIMING OF THE FRONT THROUGH METRO
/00-02Z/...THE MOST WIDESPREAD THUNDERSTORM ACTIVITY IS EXPECTED
DURING THE EVENING.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FT THIS MORNING AND
AFTERNOON. HIGH CONFIDENCE THIS EVENING AND TONIGHT.
* MEDIUM CONFIDENCE IN THUNDERSTORMS IMPACTING THE AIRPORT THIS
EVENING.
&&
.PREV DISCUSSION...ISSUED 331 AM EDT TUE MAY 13 2014
SHORT TERM...TODAY AND TONIGHT
AS OF 07Z...THE SURFACE WARM FRONT APPEARS TO HAVE CLEARED THE TRI
CITIES AND BAD AXE AND IS NOW HUGGING THE LAKE HURON
SHORELINE...WHERE THE MARINE LAYER HAS PROVEN A FORMIDABLE OBSTACLE
IN THE NORTHEAST PROGRESS OF THIS FRONT. SFC LOW PRESSURE CENTERED
OVER FAR WRN LAKE SUPERIOR WILL LIFT INTO NORTHERN ONTARIO TODAY IN
ADVANCE OF A MID LEVEL SHORT WAVE NOW LIFTING UP THROUGH MINNESOTA.
DESPITE THE STEADY STATE NATURE OF THE LONG WAVE TOUGH OVER THE
PLAINS AND MID LEVEL RIDGE OVER THE NORTHERN LAKES...THE SFC COLD
FRONT /NOW EXTENDING ACROSS CNTL WI AND WRN IL/ WILL BE DRIVEN
ACROSS SE MI BETWEEN 21Z AND 02Z THIS EVENING AS THE SFC LOW LIFTS
NORTH. STRENGTHENING LOW LEVEL S-SW FLOW IN ADVANCE OF THE FRONT
WILL HOLD THE WARM FRONT NORTH OF THE AREA...POSSIBLY PUSHING IT
OFFSHORE OF THE THUMB.
EXTENSIVE PREFRONTAL THUNDERSTORMS YESTERDAY HAVE LED TO NUMEROUS
CONVECTIVELY INDUCED MID LEVEL SHORT WAVES. A PAIR OF THESE MCVS NOW
STRETCHING FROM IL TO CNTRL LAKE MI WILL TRACK ACROSS WRN AND CNRL
LOWER MI THIS MORNING AND EARLY AFTERNOON. ENHANCED LIFT ASSOCIATED
WITH THESE FEATURES WILL LIKELY ALLOW SOME CONVECTION TO PECULATE
WELL IN ADVANCE OF THE SFC COLD FRONT. SOME OF THIS CONVECTION MAY
INFILTRATE AT LEAST THE WESTERN PORTIONS OF THE FORECAST AREA
THROUGH EARLY AFTERNOON. WITH SE MI FIRMLY WITHIN THE WARM
SECTOR...TEMPS SHOULD HAVE NO PROBLEM RISING WELL INTO THE 70S TODAY
/PERHAPS SOME LOW 80S OVER THE EAST/ EVEN WITH SOME RESIDUAL
CONVECTIVE CLOUD DEBRIS. ASSUMING AFTERNOON TEMPS REACH UPPER 70S
WITH SFC DEWPOINTS IN THE MID/UPPER 60S...SB CAPE SHOULD REACH 1500
J/KG. WITH 0-6KM BULK SHEAR AROUND 35 KNOTS...A FEW STRONG TO
POTENTIALLY SEVERE STORMS STILL LOOK POSSIBLE /STRONG WINDS BEING
THE MAIN HAZARD/. THE DEEP LAYER MOISTURE AND THUS LOW CAPE DENSITY
ALONG WITH UNCERTAINTY AS TO HOW MUCH WARMING WILL OCCUR IN THE
BOUNDARY LAYER TODAY SEEM TO BE THE MAIN LIMITING FACTORS FOR THE
INCLUSION OF SE MI IN A SLIGHT RISK FOR SEVERE WEATHER AT THIS TIME.
GIVEN THE RATHER GOOD DENSITY GRADIENT ALONG THE SFC COLD
FRONT...LOW LEVEL CONVERGENCE SHOULD STILL PROVE EFFICIENT IN
PROVIDING A GENEROUS COVERAGE OF CONVECTION LATE THIS AFTERNOON AND
EVENING. WITH PRECIP WATER AROUND 1.6 INCHES AND FAIRLY HIGH DEEP
LAYER MEAN RH...THUNDERSTORMS WILL AGAIN BE CAPABLE OF PRODUCING
FAIRLY INTENSE RAINFALL RATES. THE SLOW MOVEMENT OF THE SFC COLD
FRONT DUE TO THE MEAN DEEP LAYER FLOW NEARLY PARALLELING THE FRONT
COULD AGAIN POSE SOME LOCALIZED HIGH RAINFALL AMOUNTS AND FLOODING.
WHILE THE SFC FRONT AND INSTABILITY WILL SLIDE EAST OF THE AREA BY
03Z...GOOD FGEN WITHIN THE 925-850MB LAYER AND AMPLE DEEP LAYER POST
FRONTAL MOISTURE SHOULD SUSTAIN SHOWERS OVER MUCH OF THE AREA WELL
INTO THE NIGHT.
LONG TERM...
THE LONGWAVE NORTH AMERICAN TROUGH CENTERED JUST EAST OF THE ROCKIES
WILL UNDERGO FURTHER PHASING/CONSOLATION OF UPPER LEVEL PV AS
SOUTHERN ENERGY EJECTS OUT OF THE FOUR CORNERS REGION...LEADING TO
DEEPENING AND CLOSED 500 MB LOW OVER THE MIDWEST ON THURSDAY.
ABUNDANT RESERVOIR OF MOISTURE...BOTH PACIFIED AND GULF OF MEXICO
MOISTURE OVER EASTERN MEXICO WILL BE SURGING NORTHWARD ONCE
AGAIN...ALLOWING RAIN TO DEVELOP LATE WEDNESDAY
AFTERNOON...PERSISTING AT LEAST INTO THURSDAY...AS DEEPENING SURFACE
LOW TRACKS FROM THE WESTERN GULF COAST STATES...NORTH/NORTHEAST
THROUGH THE CENTRAL OHIO VALLEY AND THROUGH/OR CLOSE TO SOUTHEAST
MICHIGAN. PER 00Z NAM...EXCELLENT LARGE SCALE ASCENT FOR AN EXTENDED
PERIOD...COUPLED WITH THE GOOD MOISTURE (850 MB DEW PTS OF 10+
C...700 MB DEW PTS UP AROUND 2 C)...MODEST INSTABILITY (SHOWALTER
INDEX DROPPING TO ZERO OR SLIGHTLY NEGATIVE BY THURSDAY
MORNING)...WILL RESULT IN RAIN...HEAVY AT TIMES...AND WIDESPREAD
RAINFALL IN EXCESS OF 1 INCH APPEARS POSSIBLE...WHICH WOULD LIKELY
LEAD TO ADDITIONAL FLOODING CONCERNS WITH RECENT HEAVY
RAINFALL/ALREADY SOAKED GROUND/ELEVATED RIVERS. TROUGH AXIS
POTENTIALLY GOING NEGATIVELY TILTED THURSDAY NIGHT MAY PROLONG THE
RAIN A BIT LONGER. HOWEVER...THE 00Z EURO HAS COME IN MUCH WEAKER
LOW/SOLUTION THAN ITS 12Z RUN...AND THUS SHOWS THE MAJORITY OF RAIN
OCCURRING BEFORE 12Z THURSDAY AS THE MID LEVEL DRY SLOT TAKES HOLD
ON THURSDAY.
DRYING OUT AS WE HEAD INTO THE WEEKEND...BUT COLDER TEMPERATURES
WILL BE THE WEATHER STORY...AS COLD POOL ALOFT MOVES OVER THE GREAT
LAKES REGION...AND 00Z MODELS CONTINUE TO SHOW 850 MB TEMPS DIPPING
SLIGHTLY BELOW ZERO FOR FIRST HALF OF THE WEEKEND. THIS COLDER
AIRMASS WILL LEAD TO STEEP LOW LEVEL LAPSE RATES DURING THE
AFTERNOON HOURS...SUFFICIENT FOR CU UP AND ISOLATED-SCATTERED
SHOWERS...WITH FROST POSSIBLE AT NIGHT AS CLOUDS TEND TO DISSIPATE.
MARINE...
WARM AND MOIST AIR LIFTING OVER THE COLDER WATERS OF LAKE HURON IS
EXPECTED TO PRODUCE AREAS OF DENSE FOG TODAY...ALONG WITH ADDITIONAL
SHOWERS AND THUNDERSTORMS...AS COLD FRONT SWEEPS THROUGH THE CENTRAL
GREAT LAKES LATE TODAY. OUTSIDE OF ANY THUNDERSTORMS...WINDS ARE
EXPECTED TO REMAIN UNDER 20 KNOTS AS THEY GRADUALLY VEER FROM A
SOUTHERLY DIRECTION TO THE WEST BEHIND THE COLD FRONT. LIGHT WINDS
ON WEDNESDAY WILL GIVE WAY TO INCREASING NORTHEAST WINDS AS A LOW
TRACKS INTO SOUTHWESTERN ONTARO. FUNNELING THROUGH SAGINAW BAY COULD
PRODUCE WIND GUSTS OF 25 TO 30 KNOTS ON THURSDAY AS COLDER AIR
FILTERS IN THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
DENSE FOG ADVISORY...LHZ363-LHZ421-LHZ441-LHZ442-LHZ443-LHZ462-
LHZ463-LHZ464...UNTIL 8 AM WEDNESDAY.
DENSE FOG ADVISORY...LHZ362...UNTIL 4 AM WEDNESDAY.
DENSE FOG ADVISORY...LHZ361...UNTIL 11 PM TUESDAY.
DENSE FOG ADVISORY...INNER SAGINAW BAY...UNTIL 1 PM TUESDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......MR
AVIATION.....SC
SHORT TERM...SC
LONG TERM....SF
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
710 AM EDT TUE MAY 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT TUE MAY 13 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED AN AMPLIFIED TROF
OVER THE CNTRL CONUS. WITHIN THE TROF...ONE SHORTWAVE WAS LIFTING
THRU NRN MN INTO NRN ONTARIO. ANOTHER SHORTWAVE WAS LINGERING IN THE
BASE OF THE TROF OVER NM/CO. THIS SHORTWAVE MAY BRING SOME
INTERESTING WEATHER LATER THIS WEEK DEPENDING ON HOW IT INTERACTS
WITH OTHER NRN STREAM ENERGY DIVING INTO THE TROF. WITH THE
SHORTWAVE LIFTING INTO NRN ONTARIO...SFC LOW PRES WAS TRACKING N
ACROSS WRN LAKE SUPERIOR. OCCLUDED FRONT WAS SWEEPING INTO WRN UPPER
MI WHILE SFC WARM FRONT IS STILL HELD UP S OF UPPER MI.
FORTUNATELY...LITTLE PCPN HAS FALLEN SINCE SHRA MOVED THRU THE FCST
AREA YESTERDAY MORNING/EARLY AFTN. THIS WILL HELP EASE RISES ON
RIVERS THAT HAVE HIGH FLOWS.
AS OCCLUDED FRONT MARCHES ACROSS THE AREA THIS MORNING/EARLY AFTN...
WILL MAINTAIN A SHRA CHC ALONG/AHEAD OF IT. THERE MAY YET BE SOME
THUNDER OVER THE ERN FCST AREA...BUT POTENTIAL LOOKS LIMITED WITH
LITTLE INSTABILITY. MEANWHILE...FOG...LOCALLY DENSE...WILL LIFT
QUICKLY WITH FROPA. OTHER ITEM OF NOTE TODAY IS THAT HEALTHY CAA
WILL AID GUSTY WINDS...ESPECIALLY ACROSS THE KEWEENAW UNDER
FAVORABLE WESTERLY WIND DIRECTION. GUSTS SHOULD BE UP TO AROUND 40KT
AT TIMES THERE.
DRY WEATHER WILL FOLLOW FOR TONIGHT UNDER DRY AIR MASS. LOWS WILL
FALL INTO THE 30S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 450 AM EDT TUE MAY 13 2014
DEEP TROUGHING IN PLACE ON WEDNESDAY AND THIS MAY ONLY DEEPEN FURTHER
BY LATE THIS WEEK AS AN UPPER LOW SLIDES ACROSS THE GREAT LAKES.
UPPER LOW WILL ONLY SLOWLY EXIT THE UPPER GREAT LAKES THIS WEEKEND.
NOT A LOT OF PRECIPITATION WITH THE EXPECTED PATTERN /THOUGH FRIDAY
IS STILL UNCERTAIN/...BUT IT WILL REMAIN UNSETTLED AND COOL INTO AT
LEAST FIRST PART OF WEEKEND. AND STILL CANNOT COUNT OUT POTENTIAL
FOR ACCUMULATING SNOW AROUND FRIDAY THOUGH THE MODEL LEADING THE
CHARGE ON THAT IDEA THE LAST SEVERAL DAYS...THE ECMWF...HAS BACKED
AWAY FROM THAT IDEA WITH MOST RECENT MODEL RUN...AS HAS THE GEM-NH
AND THE UKMET WHICH WAS TRACKING ALONG WITH THE ECMWF FOR A WHILE
NOW. ONLY TIME WILL TELL IF THIS IS A TREND OR A TEMPORARY SHIFT.
WEDNESDAY STILL APPEARS GENERALLY QUIET. SFC LOW WILL BE OVER
NORTHERN ONTARIO WITH GRADIENT WESTERLY FLOW OVER LK SUPERIOR/UPR
MICHIGAN. GRADIENT WEAKENS ENOUGH IN THE AFTN TO RESULT IN LAKE
BREEZES. FORCING WEAKER THAN IT LOOKED 24 HR AGO AND MOISTURE RATHER
PALTRY. EVEN THOUGH THERE MAY BE BUILD UP OF HIGHER BASED CU...NOT
EXPECTING ANY SHRA IN LAKE BREEZE CONVERGENCE AREAS OF CNTRL UPR
MICHIGAN. DWPTS START DAY AROUND 30F AND MIXED LAYER DWPNT OUTPUT
POINTED TO AROUND 20 FOR INTERIOR WEST BY MID AFTN. PRETTY FEASIBLE
GIVEN THE DEPTH OF MIXING. FOR NOW DROPPED DWPNTS INTO LOW-MID 20S
WHICH RESULTS IN RH VALUES AROUND 30 PCT. FIRE WX ISSUES WILL BE
MITIGATED BY RECENT RAINFALL AND SINCE WINDS SHOULD REMAIN MAINLY
BELOW 15 MPH.
WEDNESDAY NIGHT FEATURES CONTINUED QUIET WEATHER PATTERN WITH INCREASING
NORTH GRADIENT FLOW AS HIGH PRESSURE BUILDS OVER MANITOBA/ONTARIO AND
LOW PRESSURE WAVE DEEPENS OVER OHIO VALLEY AND BEGINS TO LIFT NORTH
TO THE CENTRAL GREAT LAKES REGION. MID-HIGH CLOUDS INCREASE WHICH
WILL KEEP MIN TEMPS ABOVE FREEZING MAJORITY OF CWA.
THURSDAY INTO FRIDAY...SHORTWAVE ROUNDS BASE OF PRIMARY TROUGH ALOFT
WHILE SECONDARY JET STREAK DIGS ACROSS THE ROCKIES INTO THE WESTERN
SIDE OF THE UPPER LEVEL TROUGH. RESULT IS TROUGH ALOFT BECOMING
NEGATIVE TILTED THEN CLOSING OFF BY FRIDAY. STRONGEST SHORTWAVE
WITHIN THE TROUGH LIFTS NORTHWARD. IT IS THIS SHORTWAVE AND
ASSOCIATED SFC LOW THAT HOLDS THE KEY FOR THE THURSDAY NIGHT AND
FRIDAY FORECAST. RECENT RUNS OF THE ECMWF WERE THE MOST WRAPPED UP
AND FARTHER WEST WITH THIS WAVE AND ASSOCIATED SFC LOW. GFS MOSTLY
HAS STAYED PROGRESSIVE AND FARTHER EAST WITH THE LOW...LIFTING IT
NORTHWARD OVER THE LOWER LAKES INSTEAD OF THE CENTRAL GREAT LAKES.
LATEST ECMWF/UKMET/GEM-NH GOING THAT WAY TOO. SEEMS THAT ECMWF HAS
MORE SHORTWAVE ENERGY AHEAD OF THE TROUGH THAN WAS THERE PERVIOUSLY.
THIS RESULTS IN UPPER TROUGH STAYING MORE OPEN/POSITIVELY TILTED
WHICH KEEPS THAT MAIN SHORTWAVE JUST A BIT FARTHER EAST. AT THE SAME
TIME...ECMWF ENSEMBLE MEAN AND A FAIR AMOUNT OF ENSEMBLES FROM THE
GEM STILL CONTINUE TO SUPPORT POTENTIAL FOR FARTHER WEST SFC LOW...
SO THAT IDEA MAY NOT BE DONE JUST YET.
PRIMARY CHANGE TO THE GOING FORECAST WAS TO GO BACK TO RAIN/SNOW
SHOWERS IDEA INSTEAD OF WIDESPREAD RAIN/SNOW...BOOSTED BY DAYTIME
HEATING DUE TO INSTABILITY ALOFT WITH THE UPPER TROUGH. STILL KEPT
TEMPS CHILLY ON FRIDAY AS THERE SHOULD BE BKN-OVC SKIES WITH NORTH OR
NORTHEAST WINDS OFF LK SUPERIOR...EVEN WITHOUT A STRONGER SYSTEM.
INITIAL PLAN WAS TO PUT A MENTION OF ACCUMULATING SNOW IN THE MORNING
HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS...BUT SINCE THE MODEL
THAT WAS SHOWING THIS MOST PERSISTENTLY BACKED AWAY...WILL NOT PUT
THAT MENTION IN THERE AFTER ALL. PROBABLY NOT TOO MUCH OF A STRETCH
TO SAY THAT WILL BE FINE WITH MOST PEOPLE THAT ARE TRYING TO PUT THIS
LONG COLD WINTER...AND EARLY SPRING...BEHIND THEM.
TROUGHING GRADUALLY PULLS AWAY DURING THE WEEKEND...BUT COULD STILL
SEE POTENTIAL FOR SOME LINGERING RAIN/SNOW SHOWERS ON SATURDAY WITH
FAIR AMOUNTS OF CLOUDS. LOOKS LIKE WE WILL BE IN THE CLEAR FOR
SUNDAY AND PROBABLY MONDAY AS WELL...WITH THE RETURN OF WARMER
TEMPERATURES...ALBEIT STILL BELOW NORMAL. READINGS MAY REACH MID TO
UPR 60S INLAND WEST WHILE MOST OTHER AREAS ARE IN THE 50S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 709 AM EDT TUE MAY 13 2014
OCCLUDED FRONT SWEEPING ACROSS THE AREA THIS MORNING WILL BRING
IMPROVING CONDITIONS TO KIWD/KCMX/KSAW. INITIAL LIFR/IFR CONDITIONS
WILL STEADILY IMPROVE TO VFR BY EARLY AFTN AT THE LATEST. VFR
CONDITIONS WILL THEN PREVAIL THRU THE REMAINDER OF THE FCST PERIOD.
WESTERLY WINDS WILL ALSO BE GUSTY TODAY...ESPECIALLY AT THE MORE
EXPOSED KCMX TERMINAL WHERE GUSTS TO AROUND 35KT ARE EXPECTED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT TUE MAY 13 2014
LOW PRESSURE OVER WESTERN LK SUPERIOR WILL MOVE NORTHWARD TOWARD
HUDSON BAY TONIGHT INTO WEDNESDAY. A COLD FRONT CROSSES THE REGION
THIS MORNING SHIFTING WINDS FROM EASTERLY TO WESTERLY. WEST WINDS BY
AFTERNOON COULD REACH 30 KTS OVER PORTIONS WESTERN AND NORTH CENTRAL
LAKE SUPERIOR. THESE GUSTY WINDS WILL DIMINISH BELOW 25 KTS LATE
TONIGHT INTO WEDNESDAY MORNING. WINDS FOR THE REST OF THE WEEK WILL
MAINLY BE BLO 20 KTS. THERE DOES REMAIN SOME POTENTIAL THAT
NORTHERLY WINDS ON FRIDAY MAY REACH 30 KTS DEPENDING ON THE TRACK
AND STRENGTH OF A LOW PRESSURE SYSTEM LIFTING ACROSS THE GREAT LAKES.
&&
.HYDROLOGY...
ISSUED AT 450 AM EDT TUE MAY 13 2014
TOTAL RAINFALL AMOUNTS FROM THIS SYSTEM ENDED UP LESS THAN EXPECTED
WHICH IS RESULTING IN LESSER OVERALL RISE ON RIVERS THAN COULD HAVE
OCCURRED. ADDITIONAL RAINFALL THE NEXT COUPLE DAYS WILL BE MINIMAL.
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION...POSSIBLY IN THE FORM
OF RAIN AND SNOW...COULD ARRIVE THURSDAY NIGHT INTO FRIDAY.
HOWEVER...THE LATEST DATA IS NOT AS STRONG WITH THIS SYSTEM WHICH
RESULTS IN SCATTERED RAIN AND SNOW SHOWERS WITH ONLY LIGHT TOTAL
LIQUID EQUIVALENT PRECIPITATION. NO CHANGES HAVE BEEN MADE TO FLOOD
WARNINGS FOR THE STURGEON RIVER NEAR CHASSELL AND FOR THE MICHIGAMME
RIVER NEAR REPUBLIC...WITCH LAKE...AND TO THE EAST OF CRYSTAL FALLS
JUST DOWNSTREAM FROM WAY DAM AND HEMLOCK FALLS. SINCE NOT AS MUCH
RAIN OCCURRED OVER STURGEON RIVER BASIN IN BARAGA COUNTY THE LAST
SHIFT COORDINATED WITH THE NORTH CENTRAL RIVER FORECAST CENTER NEAR
MINNEAPOLIS AND REPLACED THE WARNING FOR THE STURGEON RIVER NEAR
ALSTON WITH AN ADVISORY.
DUE TO THE RAINFALL THAT DID OCCUR AND ONGOING SNOWMELT OVER THE
HIGHER TERRAIN OF MAINLY NORTHWEST AND NORTH CENTRAL UPPER
MICHIGAN...RIVER FLOWS WILL LIKELY REMAIN HIGH THROUGH THE REST OF
THE WEEK. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD
CONTINUE TO MONITOR THE LATEST RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR LMZ248-250.
DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1023 AM CDT TUE MAY 13 2014
.UPDATE....MARINE...
ISSUED AT 1015 AM CDT TUE MAY 13 2014
ADDED SCA TO MARINE FORECAST TODAY. ALTHOUGH SUSTAINED WINDS
MAY NOT REACH CRITERIA SPECIFICALLY...SHOULD BE ENOUGH ABOVE THRESHOLD
GUSTS WITHIN THE POST FRONTAL REGIME TO CAUSE SOME HAZARD.
UPDATE ISSUED AT 1012 AM CDT TUE MAY 13 2014
MOSTLY CLOUDY SKIES COVER MOST OF THE FORECAST AREA WITH SOME
BREAKS IN NE MN. RADAR INDICATES LIGHT RAIN/DRIZZLE ACROSS SOME
AREAS OF NE MN WITH DRIZZLE REPORTED IN NW WI. HRRR INDICATES SOME
CELLULAR SHOWERS DEVELOPING THIS AFTERNOON WITH THE AFTERNOON
HEATING. WILL EXTEND POPS INTO NW WI FOR THIS AFTERNOON. ALSO
LOWERED TEMPS A COUPLE DEGREES BASED ON CLOUD COVER AND CURRENT
TRENDS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 338 AM CDT TUE MAY 13 2014
THE SURFACE LOW WAS LOCATED OVER THE ARROWHEAD OF MINNESOTA AS OF
08Z WITH THE UPPER TROUGH EXTENDING THROUGH MANITOBA INTO THE
DAKOTAS/WESTERN MINNESOTA. THE RAIN HAS DIMINISHED QUITE A BIT
ACROSS THE AREA WITH MAINLY SOME VERY LIGHT RAIN/DRIZZLE IN SPOTS.
WE EXPECT MINIMAL COVERAGE/INTENSITY OF THE PRECIP THIS MORNING AS
THE SURFACE LOW CONTINUES TO MOVE NORTHEAST. COLDER AIR CONTINUES
TO MOVE ACROSS THE REGION BEHIND THE DEPARTING LOW. SNOW WAS
REPORTED AT SEVERAL OBSERVATIONS...INCLUDING
KVWU/KBDE/KFGN/KRRT/CYQK. RADAR SHOWS SOME OF THAT MAY AFFECT KINL
THIS MORNING...AND WE HAVE A CHANCE FOR SOME SNOW OVER OUR
NORTHERN ZONES THROUGH 16Z.
SHOWERS SHOULD DEVELOP ACROSS MUCH OF OUR MN ZONES INTO FAR
NORTHWEST WI THIS AFTERNOON. COLD TEMPS ALOFT AND SOME SHORTWAVE
ENERGY WILL HELP PROVIDE A FAVORABLE SET UP FOR AT LEAST SOME
SCATTERED SHOWERS IN SPOTS. WE EXPECT THE BOUNDARY LAYER TO WARM
ENOUGH FOR MAINLY RAIN...BUT WOULD NOT BE SURPRISED TO HEAR OF SOME
LOCALIZED SNOW SHOWERS/SLEET INTO THE AFTERNOON IF CORES ARE
STRONG ENOUGH. HIGHS SHOULD REACH THE UPPER FORTIES TO LOWER
FIFTIES.
WE KEPT A MENTION OF SHOWER INTO THE EVENING OVER PORTIONS OF
NORTHEAST MN...THEN WENT DRY LATE EVENING ON. LOWS WILL DROP INTO
THE THIRTIES.
THE UPPER TROUGH WILL MOVE A BIT FURTHER EAST INTO MINNESOTA ON
WEDNESDAY. WE HAVE CHANCE FOR MORE SHOWERS ACROSS NORTHEAST MN AND
FAR NORTHWEST WI FROM LATE MORNING INTO THE AFTERNOON. TEMPS ALOFT
REMAIN RATHER COLD...SO WE DO MENTION SOME SNOW SHOWERS OVER FAR
NORTHERN MINNESOTA AGAIN. WE WENT ALL RAIN SHOWERS LATE WEDNESDAY
MORNING INTO THE AFTERNOON...BUT AGAIN SOME ISOLATED MIXED
RAIN/SNOW SHOWERS MAY OCCUR IF PRECIP RATES ARE HIGH ENOUGH. HIGHS
WILL RANGE FROM THE UPPER FORTIES TO MID FIFTIES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 AM CDT TUE MAY 13 2014
THE EXTENDED PERIOD WILL BE DOMINATED BY A STAGNANT UPPER TROF OVER
THE CENTRAL US THAT WILL EVENTUALLY CLOSE OFF...AGAIN...LATE IN THE
WEEK. THIS WILL KEEP THE NORTHLAND IN A SOMEWHAT CLOUDY...COOL AND
WET PATTERN, ALTHOUGH THE WETTEST PERIOD IS PROBABLY BEHIND US.
A COLD FRONT WILL MOVE ACROSS THE NORTHLAND WEDNESDAY...BUT UPPER
TROF COULD KEEP SHOWERS LINGERING INTO THE EVENING...MAINLY IN
EASTERN AREAS OF CWA. BUT THAT WILL BE SHORT-LIVED AS EXPECT SOME
SHOWERS TO POP UP THURSDAY AS A COLD POOL ALOFT WILL CAUSE STEEP
ENOUGH LAPSE RATE TO GENERATE SOME SHOWERS. WITH TORRIDNESS SLOW TO
MOVE OUT...EXPECT THE SHOWERS TO CONTINUE IN THE EASTERN SECTIONS
INTO FRIDAY. WITH THE UPPER LOW CLOSING OFF OVER THE
AREA...NORTHERN WISCONSIN OR WESTERN LAKE SUPERIOR...KEPT SHOWERS
INT HE FORECAST IN THE EAST INTO SATURDAY...BUT CHANCES ARE SMALL.
IT WILL BE QUITE COOL WITH 8H TEMPS FALLING TO -4 TO -8 AND STAYING
PUT THROUGH FRIDAY. SO SOME BELOW FREEZING TEMPS EXPECTED. THE
CLOSED LOW WILL SLOWLY MOVE EAST ROUGH THE PERIOD AND BY LATE IN THE
WEENED BE EITHER OVER CENTRAL OT OR THE UP OF MI. BUT THIS ALLOW
SOME SUN AND DRYING OVER THE WEEKEND. THEN ON MONDAY ANOTHER LOW
WILL DIG INTO THE WEST COAST AND PROVIDE ANOTHER SFC LOW TO MOVE
TOWARD THE REGION FOR THE REST OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 636 AM CDT TUE MAY 13 2014
RESIDUAL CLOUDS AND DRIZZLE REMAIN BEHIND A LOW PRESSURE AREA. THE
IFR CONDITIONS WITH CIGS LESS THAN 1K FEET COVERED THE FORECAST
AREA. HOWEVER THERE WILL BE A IMPROVEMENT IN CIGS TO MVFR AFT 13Z-
14Z THEN VFR AFT 17Z-18Z. THERE MAY BE SOME INSTABILITY SHOWERS
POPPING UP THIS AFTERNOON AND ENDING BY 00Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 34 51 32 / 30 20 20 10
INL 46 31 47 30 / 50 40 40 10
BRD 51 34 54 32 / 30 20 30 10
HYR 49 34 57 32 / 30 10 10 10
ASX 47 34 52 31 / 30 10 10 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
LSZ140>147.
&&
$$
MARINE...CANNON
UPDATE...STEWART
SHORT TERM...MELDE
LONG TERM...CLC
AVIATION...CLC
AREA FORECAST DISCUSSION
NWS DULUTH MN
1015 AM CDT TUE MAY 13 2014
.UPDATE...
ISSUED AT 1012 AM CDT TUE MAY 13 2014
MOSTLY CLOUDY SKIES COVER MOST OF THE FORECAST AREA WITH SOME
BREAKS IN NE MN. RADAR INDICATES LIGHT RAIN/DRIZZLE ACROSS SOME
AREAS OF NE MN WITH DRIZZLE REPORTED IN NW WI. HRRR INDICATES SOME
CELLEUR SHOWERS DEVELOPING THIS AFTERNOON WITH THE AFTERNOON
HEATING. WILL EXTEND POPS INTO NW WI FOR THIS AFTERNOON. ALSO
LOWERED TEMPS A COUPLE DEGREES BASED ON CLOUD COVER AND CURRENT TRENDS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 338 AM CDT TUE MAY 13 2014
THE SURFACE LOW WAS LOCATED OVER THE ARROWHEAD OF MINNESOTA AS OF
08Z WITH THE UPPER TROUGH EXTENDING THROUGH MANITOBA INTO THE
DAKOTAS/WESTERN MINNESOTA. THE RAIN HAS DIMINISHED QUITE A BIT
ACROSS THE AREA WITH MAINLY SOME VERY LIGHT RAIN/DRIZZLE IN SPOTS.
WE EXPECT MINIMAL COVERAGE/INTENSITY OF THE PRECIP THIS MORNING AS
THE SURFACE LOW CONTINUES TO MOVE NORTHEAST. COLDER AIR CONTINUES
TO MOVE ACROSS THE REGION BEHIND THE DEPARTING LOW. SNOW WAS
REPORTED AT SEVERAL OBSERVATIONS...INCLUDING
KVWU/KBDE/KFGN/KRRT/CYQK. RADAR SHOWS SOME OF THAT MAY AFFECT KINL
THIS MORNING...AND WE HAVE A CHANCE FOR SOME SNOW OVER OUR
NORTHERN ZONES THROUGH 16Z.
SHOWERS SHOULD DEVELOP ACROSS MUCH OF OUR MN ZONES INTO FAR
NORTHWEST WI THIS AFTERNOON. COLD TEMPS ALOFT AND SOME SHORTWAVE
ENERGY WILL HELP PROVIDE A FAVORABLE SET UP FOR AT LEAST SOME
SCATTERED SHOWERS IN SPOTS. WE EXPECT THE BOUNDARY LAYER TO WARM
ENOUGH FOR MAINLY RAIN...BUT WOULD NOT BE SURPRISED TO HEAR OF SOME
LOCALIZED SNOW SHOWERS/SLEET INTO THE AFTERNOON IF CORES ARE
STRONG ENOUGH. HIGHS SHOULD REACH THE UPPER FORTIES TO LOWER
FIFTIES.
WE KEPT A MENTION OF SHOWER INTO THE EVENING OVER PORTIONS OF
NORTHEAST MN...THEN WENT DRY LATE EVENING ON. LOWS WILL DROP INTO
THE THIRTIES.
THE UPPER TROUGH WILL MOVE A BIT FURTHER EAST INTO MINNESOTA ON
WEDNESDAY. WE HAVE CHANCE FOR MORE SHOWERS ACROSS NORTHEAST MN AND
FAR NORTHWEST WI FROM LATE MORNING INTO THE AFTERNOON. TEMPS ALOFT
REMAIN RATHER COLD...SO WE DO MENTION SOME SNOW SHOWERS OVER FAR
NORTHERN MINNESOTA AGAIN. WE WENT ALL RAIN SHOWERS LATE WEDNESDAY
MORNING INTO THE AFTERNOON...BUT AGAIN SOME ISOLATED MIXED
RAIN/SNOW SHOWERS MAY OCCUR IF PRECIP RATES ARE HIGH ENOUGH. HIGHS
WILL RANGE FROM THE UPPER FORTIES TO MID FIFTIES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 AM CDT TUE MAY 13 2014
THE EXTENDED PERIOD WILL BE DOMINATED BY A STAGNANT UPPER TROF OVER
THE CENTRAL US THAT WILL EVENTUALLY CLOSE OFF...AGAIN...LATE IN THE
WEEK. THIS WILL KEEP THE NORTHLAND IN A SOMEWHAT CLOUDY...COOL AND
WET PATTERN, ALTHOUGH THE WETTEST PERIOD IS PROBABLY BEHIND US.
A COLD FRONT WILL MOVE ACROSS THE NORTHLAND WEDNESDAY...BUT UPPER
TROF COULD KEEP SHOWERS LINGERING INTO THE EVENING...MAINLY IN
EASTERN AREAS OF CWA. BUT THAT WILL BE SHORT-LIVED AS EXPECT SOME
SHOWERS TO POP UP THURSDAY AS A COLD POOL ALOFT WILL CAUSE STEEP
ENOUGH LAPSE RATE TO GENERATE SOME SHOWERS. WITH TORRIDNESS SLOW TO
MOVE OUT...EXPECT THE SHOWERS TO CONTINUE IN THE EASTERN SECTIONS
INTO FRIDAY. WITH THE UPPER LOW CLOSING OFF OVER THE
AREA...NORTHERN WISCONSIN OR WESTERN LAKE SUPERIOR...KEPT SHOWERS
INT HE FORECAST IN THE EAST INTO SATURDAY...BUT CHANCES ARE SMALL.
IT WILL BE QUITE COOL WITH 8H TEMPS FALLING TO -4 TO -8 AND STAYING
PUT THROUGH FRIDAY. SO SOME BELOW FREEZING TEMPS EXPECTED. THE
CLOSED LOW WILL SLOWLY MOVE EAST ROUGH THE PERIOD AND BY LATE IN THE
WEENED BE EITHER OVER CENTRAL OT OR THE UP OF MI. BUT THIS ALLOW
SOME SUN AND DRYING OVER THE WEEKEND. THEN ON MONDAY ANOTHER LOW
WILL DIG INTO THE WEST COAST AND PROVIDE ANOTHER SFC LOW TO MOVE
TOWARD THE REGION FOR THE REST OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 636 AM CDT TUE MAY 13 2014
RESIDUAL CLOUDS AND DRIZZLE REMAIN BEHIND A LOW PRESSURE AREA. THE
IFR CONDITIONS WITH CIGS LESS THAN 1K FEET COVERED THE FORECAST
AREA. HOWEVER THERE WILL BE A IMPROVEMENT IN CIGS TO MVFR AFT 13Z-
14Z THEN VFR AFT 17Z-18Z. THERE MAY BE SOME INSTABILITY SHOWERS
POPPING UP THIS AFTERNOON AND ENDING BY 00Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 34 51 32 / 30 20 20 10
INL 46 31 47 30 / 50 40 40 10
BRD 51 34 54 32 / 30 20 30 10
HYR 49 34 57 32 / 30 10 10 10
ASX 47 34 52 31 / 30 10 10 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
LSZ140>147.
&&
$$
UPDATE...STEWART
SHORT TERM...MELDE
LONG TERM...CLC
AVIATION...CLC
AREA FORECAST DISCUSSION
NWS GLASGOW MT
956 AM MDT TUE MAY 13 2014
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
ALTERED FORECAST TO INCREASE CHANCE FOR CONVECTIVE SHOWERS IN
SOUTHWEST PARTS OF THE CWA. LAKE WIND ADVISORY STILL LOOKS GOOD
FOR THIS AFTERNOON. WARMED TODAYS HIGH A COUPLE DEGREES AS WELL AS
TEMPERATURE OBSERVATIONS ARE RUNNING AHEAD OF FORECAST.
DEEP MIXING IS EXPECTED AGAIN THIS AFTERNOON WHICH WILL BRING
WINDS AS HIGH AS 650MB DOWN TO THE SURFACE AND CREATE A FIELD OF
AFTERNOON CUMULUS. SURFACE WIND WILL DECLINE QUICKLY ONCE SURFACE
HEATING CEASES.
SHORT TERM MODELS (HRRR AND SREF) BOTH HAVE A
GOOD CHANCE OF A CONVECTIVE SHOWER THIS AFTERNOON IN THE AREA
AROUND PETROLEUM COUNTY. THE HRRR EVEN HAS A LITTLE CAPE IN THE
AREA...SO ADDED A MENTION OF ISOLATED THUNDER IN THE AREA.
MARTIN
PREVIOUS DISCUSSION...
AN AMPLIFIED LONG-WAVE PATTERN EXISTS OVER NORTH AMERICAN. THERE
IS A RIDGE AXIS ALONG THE PACIFIC COAST AND DEEP TROUGH THAT
EXTENDS FROM HUDSON BAY TO THE SOUTHWEST DESERT. NORTHEAST
MONTANA...BETWEEN THESE TWO AIR MASSES...WILL SEE FLOW ALOFT FROM
THE NORTHWEST THROUGH THE SHORT TERM FORECAST PERIOD. THE
STATIONARY BOUNDARY WILL BE FOCUS OF ISOLATED TO SCATTERED
AFTERNOON AND EVENING SHOWERS THROUGH THURSDAY. THE MODELS ARE
SHOWING SOME WEAK TO MODERATE CONVECTIVE PARAMETERS...MAINLY OVER
CENTRAL AND SOUTHEAST MONTANA. BUT OUR WESTERN ZONES COULD SEE
SOME SHOWERS OR THUNDERSTORMS DEVELOP. WILL KEEP IN SLIGHT CHANCE
TO CHANCE POPS IN THE WESTERN ZONES FOR THIS AFTERNOON AND
EVENING...AND AGAIN ON WEDNESDAY. THURSDAY THE BOUNDARY SHIFTS A
BIT EAST WITH WEAK EMBEDDED DISTURBANCES IN THE UPPER FLOW TO
BRING THE BEST CHANCE FOR SHOWERS AND THUNDER DURING THE SHORT
TERM.
WITH NORTHEAST MONTANA GENERALLY BETWEEN THE WARM AIR MASS TO THE
WEST AND THE COOLER AIR MASS TO THE EAST...TEMPERATURES WILL BE
CLOSE TO NORMAL OR JUST SLIGHTLY COOLER.
TODAY/TONIGHT...THE CLOSED SURFACE AND UPPER LOWS BEGIN TO STACK
UP OVER SOUTHERN MANITOBA TO FORM A COMPACT CYCLONE. THIS WILL
SET A REINFORCING VERTICAL WIND PROFILE OVER NEMONT. EFFICIENT
MIXING FROM AS HIGH AS 600MB COULD CREATE STRONG WIND GUSTS OVER
THE LAKE. THE RESULT WILL ONCE AGAIN REQUIRE A WIND ADVISORY
OVER FORT PECK LAKE FOR NW WIND OF 15-25KT. WIND ON WEDNESDAY AND
THURSDAY WILL BE MUCH DIMINISHED AND NOT NEED AN ADVISORY. SCT
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
STILL REASONABLE AGREEMENT AMONG THE MODES FOR THE EXTENDED PERIOD
ALTHOUGH SOME DIFFERENCES DEVELOPING REGARDING THE UPPER LOW
FOR EARLY NEXT WEEK. DEEP UPPER TROF REMAINS OVER THE EASTERN
STATES DUE TO BLOCKING IN THE ATLANTIC. UPPER RIDGE OVER THE
WESTERN STATES WILL BEGIN TO FLATTEN WITH EAST PACIFIC LOW
MIGRATING TOWARD THE PACIFIC NORTHWEST.
MODELS SLOWING THE EASTWARD PROGRESSION OF THE UPPER LOW SLIGHTLY
WHICH WILL KEEP THE RIDGE OVER MONTANA THROUGH SATURDAY. WITH ONLY
WEAK INSTABILITY AND LIMITED MOISTURE AS WELL AS THE POSITION OF
THE RIDGE AXIS OVER CENTRAL MONTANA...THREAT FOR THUNDER VERY LOW
OF SATURDAY. PATTERN BECOMES MUCH MORE FAVORABLE FOR THUNDERSTORMS
ON SUNDAY WITH SOUTHWEST FLOW ALOFT AND STRENGTHENING SOUTHEAST
LOW LEVEL JET ACROSS THE DAKOTAS.
BLOCKING PATTERN TO THE EAST EXPECTED TO KEEP UPPER LOW OVER THE
REGION INTO THE MIDDLE OF NEXT WEEK. EC IS CONSISTENT WITH SLOWLY
MOVING THE LOW EAST ALONG THE CANADIAN BORDER WHILE THE GEFS IS
DIGGING THE LOW SOUTH THROUGH THE GREAT BASIN. BOTH PATTERNS ARE
GENERALLY WET FOR NORTHEAST MONTANA...ALTHOUGH THE EC HAS BETTER
POTENTIAL FOR DRY SLOT OVER AT LEAST PART OF THE CWA FOR EARLY
NEXT WEEK. EBERT
&&
.AVIATION...
FLIGHT CATEGORY: VFR
SYNOPSIS: TODAY... A BAND OF MID LEVEL CLOUDS WILL SLIDE ACROSS
THE TERMINALS FROM THE NORTH ON THE EDGE OF A RIDGE LOCATED OVER
THE INTERMOUNTAIN WEST.
AREA WINDS: DEEP MIXING EXPECTED AGAIN TODAY. THIS WILL MAKE FOR
NORTH TO NORTHWEST WINDS OF 15 TO 20 KTS WITH GUSTS UP TO 30KTS
POSSIBLE THROUGH THE AFTERNOON. THEN CALMING TO 5 TO 10 KTS AFTER
SUNSET THROUGH OVERNIGHT.
GAH
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
701 AM EDT TUE MAY 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH
WEDNESDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. OUR PATTERN WILL
REMAIN UNSETTLED INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
7 AM UPDATE...
FORECAST ADJUSTED TO FOR RADAR AND MODEL TRENDS. COMPLEX DEVELOPED
ON LEADING EDGE OF 850MB JET BUT IS NOW OUTRUNNING INTO MORE
STABLE AIR AS DOES SO. PRECIPITABLE WATER VALUES TO AROUND AN
INCH-AND-A-HALF MAY LEAD TO LOCALLY HEAVY RAINFALL IN CENTRAL TWIN
TIERS AND FINGER LAKES REGION LATER TODAY. COULD LEAD TO PONDING
IN POOR DRAINAGE AREAS.
PREVIOUS DISCUSSION...
AT 430 AM...COMPLEX OF STORMS DOVE THROUGH SOUTHWEST PA THE LAST
SEVERAL HOURS...AND THEN WEAKENED. HOWEVER...NEW CONVECTION HAS
FIRED AT LEADING EDGE OF 850MB JET...ALSO COINCIDING WITH A WEAK
WAVE ALOFT...EXTENDING FROM THE ONTARIO PENINSULA TO THE WESTERN
TIP OF NY AND SOME OF WESTERN PA. MEANWHILE...JUST A FEW SHOWERS
HAVE RESULTED FROM A WEAK VORTICITY MAXIMUM NOW TRAVERSING THE NY
THRUWAY CORRIDOR...WHICH IS RUNNING INTO PROGRESSIVELY MORE STABLE
AIR AND THUS NOT MUCH OF A PLAYER IN OUR WEATHER.
EARLIER RUNS OF THE WRF-ARW...NAM...GEM...AND NMM BROUGHT NOCTURNAL
CONVECTION WITH WAVE INTO THE TWIN TIERS YET INITIALIZED WITH THE
EARLIER SW PA COMPLEX TOTALLY MISSING. THUS I SIDED HRRR AND RUC13
SOLUTIONS WHICH HAD THE SW PA COMPLEX AND AS EXPECTED KEPT THINGS
PRETTY QUIET THROUGH MOST OF THE OVERNIGHT HOURS. THE NEW
CONVECTION NOW IN WESTERN NY/PA IS AT LEADING EDGE OF 850MB
JET...BUT MODELS SHOW THAT THE JET WILL WEAKEN CONSIDERABLY THE
NEXT FEW HOURS SO I ANTICIPATE THE ASSOCIATED CONVECTION TO
DIMINISH WHILE SKIMMING SOME OF OUR SW ZONES EARLY THIS MORNING.
HIGH PRESSURE IS CURRENTLY SLIDING OUT OF QUEBEC TO MAINE/CANADIAN
MARITIME PROVINCES...INITIATING COOL AIR DAMMING DOWN THE
APPALACHIANS. SOUTHEAST LOW LEVEL FLOW WILL DEVELOP
TODAY...SETTING UP A SURFACE CONVERGENCE ZONE IN VICINITY OF
FINGER LAKES TO CENTRAL SOUTHERN TIER OF NY. I THUS HAVE PLACED
HIGH CHANCE POPS IN CENTRAL SOUTHERN TIER TO FINGER LAKES FOR LATE
MORNING TO AFTERNOON TODAY. MODEL SOUNDINGS THERE SHOW SUFFICIENT
INSTABILITY FOR THUNDER TO ACCOMPANY THOSE SHOWERS...AND
PRECIPITABLE WATER VALUES OF NEARLY AN INCH-AND-A-HALF.
HOWEVER...THE FARTHER EAST THAT ACTIVITY MANAGES TO PROCEED...THE
DEEPER INTO THE MORE STABLE SOUTHEAST FLOW /VIA COOL AIR DAMMING
ALONG EAST COAST/ IT WILL GET. THUS LOWER CHANCES FOR SHOWERS AND
ONLY SLIGHT CHANCE OF THUNDER AT MOST. I DO NOT EVEN INCLUDE
THUNDER MENTION IN WESTERN CATSKILLS TO POCONOS.
NOT QUITE AS WARM AS MONDAY...DUE TO CLOUD COVERAGE IN WEST AND
MARINE INFLUENCED LOW LEVEL FLOW IN EAST...YET STILL 70S FOR MOST OF
THE AREA. SOME LOWER ELEVATIONS IN TWIN TIERS TO FINGER LAKES
COULD EVEN STILL MANAGE 80 DEGREES.
UPPER RIDGE PASSES OVER THE REGION TONIGHT. THERE WILL BE
MARGINAL ELEVATED INSTABILITY ALOFT IN THE WESTERN ZONES...BUT
LACK OF FORCING MECHANISMS OTHER THAN WEAK WAVES TRYING TO RIDE
THROUGH THE RIDGE HAS ME HESITANT TO GO ANY HIGHER THAN SLIGHT TO
LOW CHANCE POPS. LOWS TONIGHT IN THE 50S TO LOW 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
445 AM UPDATE...
MAIN ADJUSTMENT WAS TO FURTHER DELAY THE HIGHEST RAIN CHANCES
ASSOCIATED WITH INCOMING COLD-OCCLUDED FRONTAL ZONE. THERE WILL
STILL BE SHOWERS AROUND...PARTICULARLY WEDNESDAY AS NORTHERN STREAM
SURFACE FRONT EDGES INTO THE AREA BEFORE SHIFTING BACK NORTH.
THERE WILL ALSO BE MARGINAL INSTABILITY SUPPORTING MENTION OF
THUNDER IN CENTRAL TO NORTHERN ZONES. HOWEVER...MUCH OF THE TIME
OVERALL WILL BE DRY...ESPECIALLY THURSDAY. THE SLOWER TIMING OF
INCOMING SYSTEM ALSO FORCED A WARMER ADJUSTMENT FOR HIGH
TEMPERATURES THURSDAY TO MAINLY 75-80 DEGREE RANGE...THANKS TO
WARM SECTOR FIRMLY REASSERTING ITSELF WELL AHEAD OF THE COLD
FRONT. RAIN CHANCES THEN INCREASE THURSDAY NIGHT AS THAT COLD
FRONT APPROACHES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
350 AM UPDATE...
NO MAJOR CHANGES NEEDED THIS MORNING WITH ALL ATTENTION REMAINING
FOCUSED ON LATE WEEK RAIN EVENT. FCST MODELS NOW COMING INTO
BETTER AGREEMENT ON TIMING OF FROPA...WITH MOST SUGGESTING FEATURE
WILL PASS ACROSS THE REGION AFTER 12Z FRI. MAIN CONCERNS RIGHT NOW
APPEAR TO BE A POSSIBLE PERIOD OF HEAVY RAINFALL AS 850 U-WIND
SPEEDS OF 2-3 STANDARD DEVIATIONS ABOVE NORMAL PUMP AMPLE GULF OF
MEXICO AND WESTERN ATLANTIC MOISTURE NORTH TOWARDS OUR AREA. AS
IT STANDS RIGHT NOW...FEATURE LOOKS TO PASS QUICK ENOUGH TO
HOPEFULLY NEGATE ANY SIGNIFICANT HYDRO IMPACTS BUT LATER MODEL
RUNS WILL BE ABLE TO VERIFY THIS TREND. OVERALL CONVECTIVE
POTENTIAL LOOKS LIMITED AS THE HEAVIEST RAINS ARE EXPECTED IN A
POST FRONTAL (ANAFRONT-TYPE) AIRMASS WHERE INSTABILITY WILL BE LIMITED.
AFTER THIS FEATURE PASSES...EXPECT COOLER THAN NORMAL WEATHER INTO
THE UPCOMING WEEKEND AS SLOW MOVING UPPER LOW GRADUALLY ADVANCES
EAST INTO NEW ENGLAND AND NORTHERLY FLOW RETURNS TO THE AREA.
210 PM UPDATE...
EXTNDD PD STARTS OFF WITH H5 LOW BEGINNING TO CLOSE OFF IN THE WRN
GREAT LKS WITH FRONTAL BNDRY MEANDERING NR AREA THRU THE END OF THE
WEEK AND FIRST HALF OF THE WEEKEND. SVRL WVS OF LOPRES WL RIDE UP
ALONG BNDRY, WITH HEAVIEST RAIN LKLY THUR NGT AND FRI AHD OF CDFNT.
WITH BNDRY ON OUR DOORSTEP LATE THUR NGT/FRI MRNG EXPECT CHCS FOR
THUNDER AT ANY TIME TO START OFF THE LONG TERM. WL WORD IT AS CHC
TSTMS FOR THUR NGT WITH LKLY SHOWERS/THUNDER DRG THE DAY ON FRIDAY
WITH TIMING LKLY TO BE NAILED DOWN THE CLOSER WE GET TO THE END OF
THE WEEK. LATEST EURO IS FASTER THAN THE GFS/CMC ON PROGRESSION OF
FROPA WITH LATTER MODELS DELAYING ITS ARRIVAL UNTIL CLOSE TO 00Z SAT
WHILE EURO CLRS CWA BY 12Z FRIDAY.
UNSETTLED WX CONTS THRU THE EARLY PART OF THE WEEK AS ERN U.S. TROF
RMNS IN PLACE. LATEST GFS INDICATE H5 LOW CLOSING OFF AGAIN OVR THE
NORTHEAST U.S. ON MONDAY THUS WL KEEP CHC POPS IN AFT 12Z SATURDAY
WITH POTENTIAL COLD POOL ALOFT CAUSING INSTABILITY SHOWERS.
TEMPS THRU THE PD WL BE NR NORMAL TO SLIGHTLY BLO NORMAL UNDER
EXTENSIVE CLD CVR AND SHOWERY CONDS.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
MODERATE TO HEAVY RAINS ONGOING ACROSS THE WESTERN SOUTHERN TIER
THIS MORNING...WITH DRY CONDITIONS NOTED DOWNSTREAM ACROSS
CENTRAL NY AND NE PA. MAIN CONCERNS OUT OF THE GATE WILL INVOLVE
TSRA POTENTIAL AT BOTH ELM AND ITH AS WESTERN NY ACTIVITY SLIDES
EAST WITH TIME. FOR NOW...CURRENT THINKING IS UPSTREAM ACTIVITY WILL
BEGIN TO WEAKEN WITH FURTHER EASTWARD PROGRESS AS IT OUTRUNS THE
BEST LOW-LEVEL MOISTURE ADVECTION NOW CENTERED ACROSS THE OHIO VLY
AND SOUTHERN ONTARIO. THAT SAID...HAVE ELECTED TO OFFER A TEMPO
TSRA MENTION AT BOTH SITES AS LIGHTNING ACTIVITY CONTINUES TO
DEVELOP FURTHER AND FURTHER DOWNSTREAM. ELSEWHERE...VFR CONDITIONS
EXPECTED THROUGH THE REMAINDER OF THE AM HOURS.
HEADING INTO THIS AFTERNOON...REDEVELOPING SHWRS POSSIBLE ACROSS
THE WESTERN SOUTHERN TIER AGAIN AS CONVERGENCE INCREASES ALONG A
DEVELOPING SFC TROUGH. FOR NOW...HAVE ADVERTISED POTENTIAL ONLY AT
ELM AND ITH AS FCST MODELS SHOW MORE STABLE CONDITIONS DOWNSTREAM
THANKS TO HIGH PRESSURE CENTERED ACROSS SOUTHERN NEW ENGLAND.
DAYSHIFT WILL HAVE TO MONITOR TRENDS AND ADJUST ON-THE-FLY AS
NEEDED.
ANY SHWR ACTIVITY THIS AFTERNOON WILL LIKELY COME TO AN END BY
EVENING WITH LOSS OF DAYTIME HEATING. WITH DEVELOPING SOUTHEAST
FLOW...MARINE LAYER AIR WILL LIKELY ADVECT NORTH INTO THE AREA
WITH MVFR CIGS POSSIBLY DEVELOPING AT MOST SITES (EXCEPT SYR/RME)
AFTER 6Z.
OUTLOOK...
WED THROUGH THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN SHOWERS AND
THUNDERSTORMS.
THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS
COLD FRONT STALLS NEAR AREA.
SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE
AFTERNOON.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...MDP
LONG TERM...CMG
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
656 AM EDT TUE MAY 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH
WEDNESDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. OUR PATTERN WILL
REMAIN UNSETTLED INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
430 AM UPDATE...
COMPLEX OF STORMS DOVE THROUGH SOUTHWEST PA THE LAST SEVERAL
HOURS...AND THEN WEAKENED. HOWEVER...NEW CONVECTION HAS FIRED AT
LEADING EDGE OF 850MB JET...ALSO COINCIDING WITH A WEAK WAVE
ALOFT...EXTENDING FROM THE ONTARIO PENINSULA TO THE WESTERN TIP OF
NY AND SOME OF WESTERN PA. MEANWHILE...JUST A FEW SHOWERS HAVE RESULTED
FROM A WEAK VORTICITY MAXIMUM NOW TRAVERSING THE NY THRUWAY
CORRIDOR...WHICH IS RUNNING INTO PROGRESSIVELY MORE STABLE AIR AND
THUS NOT MUCH OF A PLAYER IN OUR WEATHER.
EARLIER RUNS OF THE WRF-ARW...NAM...GEM...AND NMM BROUGHT NOCTURNAL
CONVECTION WITH WAVE INTO THE TWIN TIERS YET INITIALIZED WITH THE
EARLIER SW PA COMPLEX TOTALLY MISSING. THUS I SIDED HRRR AND RUC13
SOLUTIONS WHICH HAD THE SW PA COMPLEX AND AS EXPECTED KEPT THINGS
PRETTY QUIET THROUGH MOST OF THE OVERNIGHT HOURS. THE NEW
CONVECTION NOW IN WESTERN NY/PA IS AT LEADING EDGE OF 850MB
JET...BUT MODELS SHOW THAT THE JET WILL WEAKEN CONSIDERABLY THE
NEXT FEW HOURS SO I ANTICIPATE THE ASSOCIATED CONVECTION TO
DIMINISH WHILE SKIMMING SOME OF OUR SW ZONES EARLY THIS MORNING.
HIGH PRESSURE IS CURRENTLY SLIDING OUT OF QUEBEC TO MAINE/CANADIAN
MARITIME PROVINCES...INITIATING COOL AIR DAMMING DOWN THE
APPALACHIANS. SOUTHEAST LOW LEVEL FLOW WILL DEVELOP
TODAY...SETTING UP A SURFACE CONVERGENCE ZONE IN VICINITY OF
FINGER LAKES TO CENTRAL SOUTHERN TIER OF NY. I THUS HAVE PLACED
HIGH CHANCE POPS IN CENTRAL SOUTHERN TIER TO FINGER LAKES FOR LATE
MORNING TO AFTERNOON TODAY. MODEL SOUNDINGS THERE SHOW SUFFICIENT
INSTABILITY FOR THUNDER TO ACCOMPANY THOSE SHOWERS...AND
PRECIPITABLE WATER VALUES OF NEARLY AN INCH-AND-A-HALF.
HOWEVER...THE FARTHER EAST THAT ACTIVITY MANAGES TO PROCEED...THE
DEEPER INTO THE MORE STABLE SOUTHEAST FLOW /VIA COOL AIR DAMMING
ALONG EAST COAST/ IT WILL GET. THUS LOWER CHANCES FOR SHOWERS AND
ONLY SLIGHT CHANCE OF THUNDER AT MOST. I DO NOT EVEN INCLUDE
THUNDER MENTION IN WESTERN CATSKILLS TO POCONOS.
NOT QUITE AS WARM AS MONDAY...DUE TO CLOUD COVERAGE IN WEST AND
MARINE INFLUENCED LOW LEVEL FLOW IN EAST...YET STILL 70S FOR MOST OF
THE AREA. SOME LOWER ELEVATIONS IN TWIN TIERS TO FINGER LAKES
COULD EVEN STILL MANAGE 80 DEGREES.
UPPER RIDGE PASSES OVER THE REGION TONIGHT. THERE WILL BE
MARGINAL ELEVATED INSTABILITY ALOFT IN THE WESTERN ZONES...BUT
LACK OF FORCING MECHANISMS OTHER THAN WEAK WAVES TRYING TO RIDE
THROUGH THE RIDGE HAS ME HESITANT TO GO ANY HIGHER THAN SLIGHT TO
LOW CHANCE POPS. LOWS TONIGHT IN THE 50S TO LOW 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
445 AM UPDATE...
MAIN ADJUSTMENT WAS TO FURTHER DELAY THE HIGHEST RAIN CHANCES
ASSOCIATED WITH INCOMING COLD-OCCLUDED FRONTAL ZONE. THERE WILL
STILL BE SHOWERS AROUND...PARTICULARLY WEDNESDAY AS NORTHERN STREAM
SURFACE FRONT EDGES INTO THE AREA BEFORE SHIFTING BACK NORTH.
THERE WILL ALSO BE MARGINAL INSTABILITY SUPPORTING MENTION OF
THUNDER IN CENTRAL TO NORTHERN ZONES. HOWEVER...MUCH OF THE TIME
OVERALL WILL BE DRY...ESPECIALLY THURSDAY. THE SLOWER TIMING OF
INCOMING SYSTEM ALSO FORCED A WARMER ADJUSTMENT FOR HIGH
TEMPERATURES THURSDAY TO MAINLY 75-80 DEGREE RANGE...THANKS TO
WARM SECTOR FIRMLY REASSERTING ITSELF WELL AHEAD OF THE COLD
FRONT. RAIN CHANCES THEN INCREASE THURSDAY NIGHT AS THAT COLD
FRONT APPROACHES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
350 AM UPDATE...
NO MAJOR CHANGES NEEDED THIS MORNING WITH ALL ATTENTION REMAINING
FOCUSED ON LATE WEEK RAIN EVENT. FCST MODELS NOW COMING INTO
BETTER AGREEMENT ON TIMING OF FROPA...WITH MOST SUGGESTING FEATURE
WILL PASS ACROSS THE REGION AFTER 12Z FRI. MAIN CONCERNS RIGHT NOW
APPEAR TO BE A POSSIBLE PERIOD OF HEAVY RAINFALL AS 850 U-WIND
SPEEDS OF 2-3 STANDARD DEVIATIONS ABOVE NORMAL PUMP AMPLE GULF OF
MEXICO AND WESTERN ATLANTIC MOISTURE NORTH TOWARDS OUR AREA. AS
IT STANDS RIGHT NOW...FEATURE LOOKS TO PASS QUICK ENOUGH TO
HOPEFULLY NEGATE ANY SIGNIFICANT HYDRO IMPACTS BUT LATER MODEL
RUNS WILL BE ABLE TO VERIFY THIS TREND. OVERALL CONVECTIVE
POTENTIAL LOOKS LIMITED AS THE HEAVIEST RAINS ARE EXPECTED IN A
POST FRONTAL (ANAFRONT-TYPE) AIRMASS WHERE INSTABILITY WILL BE LIMITED.
AFTER THIS FEATURE PASSES...EXPECT COOLER THAN NORMAL WEATHER INTO
THE UPCOMING WEEKEND AS SLOW MOVING UPPER LOW GRADUALLY ADVANCES
EAST INTO NEW ENGLAND AND NORTHERLY FLOW RETURNS TO THE AREA.
210 PM UPDATE...
EXTNDD PD STARTS OFF WITH H5 LOW BEGINNING TO CLOSE OFF IN THE WRN
GREAT LKS WITH FRONTAL BNDRY MEANDERING NR AREA THRU THE END OF THE
WEEK AND FIRST HALF OF THE WEEKEND. SVRL WVS OF LOPRES WL RIDE UP
ALONG BNDRY, WITH HEAVIEST RAIN LKLY THUR NGT AND FRI AHD OF CDFNT.
WITH BNDRY ON OUR DOORSTEP LATE THUR NGT/FRI MRNG EXPECT CHCS FOR
THUNDER AT ANY TIME TO START OFF THE LONG TERM. WL WORD IT AS CHC
TSTMS FOR THUR NGT WITH LKLY SHOWERS/THUNDER DRG THE DAY ON FRIDAY
WITH TIMING LKLY TO BE NAILED DOWN THE CLOSER WE GET TO THE END OF
THE WEEK. LATEST EURO IS FASTER THAN THE GFS/CMC ON PROGRESSION OF
FROPA WITH LATTER MODELS DELAYING ITS ARRIVAL UNTIL CLOSE TO 00Z SAT
WHILE EURO CLRS CWA BY 12Z FRIDAY.
UNSETTLED WX CONTS THRU THE EARLY PART OF THE WEEK AS ERN U.S. TROF
RMNS IN PLACE. LATEST GFS INDICATE H5 LOW CLOSING OFF AGAIN OVR THE
NORTHEAST U.S. ON MONDAY THUS WL KEEP CHC POPS IN AFT 12Z SATURDAY
WITH POTENTIAL COLD POOL ALOFT CAUSING INSTABILITY SHOWERS.
TEMPS THRU THE PD WL BE NR NORMAL TO SLIGHTLY BLO NORMAL UNDER
EXTENSIVE CLD CVR AND SHOWERY CONDS.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
MODERATE TO HEAVY RAINS ONGOING ACROSS THE WESTERN SOUTHERN TIER
THIS MORNING...WITH DRY CONDITIONS NOTED DOWNSTREAM ACROSS
CENTRAL NY AND NE PA. MAIN CONCERNS OUT OF THE GATE WILL INVOLVE
TSRA POTENTIAL AT BOTH ELM AND ITH AS WESTERN NY ACTIVITY SLIDES
EAST WITH TIME. FOR NOW...CURRENT THINKING IS UPSTREAM ACTIVITY WILL
BEGIN TO WEAKEN WITH FURTHER EASTWARD PROGRESS AS IT OUTRUNS THE
BEST LOW-LEVEL MOISTURE ADVECTION NOW CENTERED ACROSS THE OHIO VLY
AND SOUTHERN ONTARIO. THAT SAID...HAVE ELECTED TO OFFER A TEMPO
TSRA MENTION AT BOTH SITES AS LIGHTNING ACTIVITY CONTINUES TO
DEVELOP FURTHER AND FURTHER DOWNSTREAM. ELSEWHERE...VFR CONDITIONS
EXPECTED THROUGH THE REMAINDER OF THE AM HOURS.
HEADING INTO THIS AFTERNOON...REDEVELOPING SHWRS POSSIBLE ACROSS
THE WESTERN SOUTHERN TIER AGAIN AS CONVERGENCE INCREASES ALONG A
DEVELOPING SFC TROUGH. FOR NOW...HAVE ADVERTISED POTENTIAL ONLY AT
ELM AND ITH AS FCST MODELS SHOW MORE STABLE CONDITIONS DOWNSTREAM
THANKS TO HIGH PRESSURE CENTERED ACROSS SOUTHERN NEW ENGLAND.
DAYSHIFT WILL HAVE TO MONITOR TRENDS AND ADJUST ON-THE-FLY AS
NEEDED.
ANY SHWR ACTIVITY THIS AFTERNOON WILL LIKELY COME TO AN END BY
EVENING WITH LOSS OF DAYTIME HEATING. WITH DEVELOPING SOUTHEAST
FLOW...MARINE LAYER AIR WILL LIKELY ADVECT NORTH INTO THE AREA
WITH MVFR CIGS POSSIBLY DEVELOPING AT MOST SITES (EXCEPT SYR/RME)
AFTER 6Z.
OUTLOOK...
WED THROUGH THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN SHOWERS AND
THUNDERSTORMS.
THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS
COLD FRONT STALLS NEAR AREA.
SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE
AFTERNOON.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1021 AM CDT TUE MAY 13 2014
.UPDATE...
ISSUED AT 1021 AM CDT TUE MAY 13 2014
NO SIGNIFICANT UPDATES TO THE GOING FORECAST FOR THE MORNING
UPDATE. CLEAR SKIES SOUTHWEST TO PARTLY CLOUDY NORTHEAST.
NORTHWEST WINDS WILL PICK-UP AGAIN TODAY BUT LATEST 12 UTC NAM/
13 UTC RAP BUFKIT SOUNDINGS SUGGEST WE SHOULD REMAIN BELOW
ADVISORY CRITERIA. MADE SOME MINOR ADJUSTMENTS TO BUMP UP SKY
COVER EAST AND LOWER SKY COVER WEST.
UPDATE ISSUED AT 640 AM CDT TUE MAY 13 2014
AT 6 AM CDT..LARGE SURFACE LOW PRESSURE ACROSS THE GREAT LAKES AND
ITS WIDE CIRCULATION CONTINUES TO BRING SOME CLOUDS INTO THE NORTH
CENTRAL AND EAST. INCREASED THE CLOUD COVER ACROSS THE NORTH
CENTRAL AND EAST WITH THIS UPDATE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CDT TUE MAY 13 2014
MAIN FORECAST CONCERN TODAY IS WINDS...WITH ANOTHER BREEZY/WINDY DAY
- BUT WINDS NOT AS STRONG AS THOSE ON MONDAY. TONIGHT THE MAIN
CONCERN IS TEMPERATURES - WITH UPPER 20S TO MID 30S FORECAST.
CURRENTLY...SURFACE LOW PRESSURE WAS OVER NORTHERN
WISCONSIN...WITH HIGH PRESSURE DOMINATING THE FRONT RANGE FROM
NORTHERN ALBERTA/SASKATCHEWAN TO COLORADO.
PRESSURE GRADIENT AGAIN LEADS TO STRONG NORTHWEST WINDS ALOFT. AS
TEMPERATURES RISE AND THE SURFACE LAYER MIXES WITH LAYERS ABOVE THE
SURFACE...MIXING AND MOMENTUM TRANSFER WILL RESULT IN WINDS OF 20 TO
30 MPH BY AFTERNOON MOST AREAS. FORECAST BUFR SOUNDINGS ALSO
INDICATED CU AND/OR TCU FORMING IN THE LATE AFTERNOON. ADDED A
MENTION OF ISOLATED RAIN SHOWERS/SPRINKLES LATE AFTERNOON TO EARLY
EVENING.
ANOTHER SURGE OF COOL AIR FROM THE NORTH MOVES IN TONIGHT...AND
TEMPERATURES SHOULD RANGE FROM THE UPPER 20S TO AROUND 30 IN THE
NORTHWEST AND NORTH CENTRAL...TO THE LOW TO MID 30S SOUTHWEST AND
SOUTH CENTRAL.
WE WILL BEGIN OUR FROST/FREEZE STATEMENTS DURING THE TUESDAY DAY
SHIFT...BUT WILL MENTION THE ANTICIPATING TEMPERATURES IN THE
HAZARDOUS WEATHER OUTLOOK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 13 2014
MODELS ARE IN RELATIVE GOOD AGREEMENT WITH THE 00Z ECMWF/GFS/GFS
ENSEMBLE ALL LOOKING SIMILAR. THE HIGHLIGHTS IN THE EXTENDED INCLUDE
A CONTINUATION OF THE COOL PATTERN WEDNESDAY THROUGH FRIDAY (WITH
HIGHS 55 TO 60) DUE TO A LARGE AND PERSISTENT UPPER LOW OVER HUDSON
BAY INTO THE CENTRAL PLAINS. MODELS ARE DRY DURING THIS COOL PERIOD
AS NORTH DAKOTA ENDS UP ON THE WESTERN SIDE OF THIS COLD UPPER LOW
WITH LIMITED MOISTURE AND WEAK DYNAMICS. HOWEVER THIS WILL SLOWLY
CHANGE OVER THE WEEKEND AND INTO NEXT WEEK AS THIS COLD UPPER LOW
MOVES EAST TO THE GREAT LAKES REGION AND EASTERN PACIFIC ENERGY
BEGINS TO FLATTEN THE H500 RIDGE OVER THE WEST COAST AND NUDGE IT
INLAND. BY SUNDAY THE UPPER LOW IS OVER THE NORTHWEST US AND A
SHORTWAVE RIDGE IS OVER THE NORTHERN PLAINS. BY SUNDAY SHOULD SEE
HIGH TEMPS ON SUNDAY FINALLY APPROACHING 70 DEGREES ACROSS THE
WEST...AT LEAST INTO THE MID TO UPPER 60S. SHOULD SEE SIMILAR HIGH
TEMPERATURES MONDAY AND TUESDAY BUT WITH THE CLOSED UPPER LOW MOVING
TO MONTANA THE NORTHERN PLAINS WILL BE IN AN ACTIVE PRECIPITATION
PERIOD FOR SUNDAY THROUGH TUESDAY.
FOR THE EXTENDED PERIOD ONLY TARGET OF OPPORTUNITY TO DEPART FROM
THE ALLBLEND GUIDANCE WAS SATURDAY AND SATURDAY NIGHT AS WE TRIMMED
POPS BACK FEELING THE NEW 00Z GUIDANCE WAS A BIT SLOWER TO BRING A
CHANCE FOR SHOWERS INTO THE WEST AND CENTRAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1021 AM CDT TUE MAY 13 2014
EXPECT NORTHWEST WINDS TO INCREASE TO 15 TO 25 KNOTS WITH GUSTS
TO 35 KNOTS POSSIBLE IN THE AFTERNOON...BEFORE DIMINISHING AFT
01Z. SCATTERED CLOUDS FROM KDIK-KBIS-KISN. SCT TO BKN MVFR TO LOW
VFR CIGS KMOT-KJMS THROUGH 17 UTC...THEN INCREASING VFR CEILINGS
THROUGH THE AFTERNOON. VFR CEILING EXPECTED AT ALL AERODROMES
TONIGHT THROUGH 18 UTC WEDNESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JV
LONG TERM...WAA
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
941 AM CDT TUE MAY 13 2014
.UPDATE...
ISSUED AT 941 AM CDT TUE MAY 13 2014
ALREADY SEEING THE HOLES IN THE CLOUDS ACROSS THE WESTERN FA
FILLING BACK IN WITH CUMULUS. WITH THE COLD POOL MOVING DOWN OVER
THE AREA TODAY EXPECT MOSTLY CLOUDY SKIES WITH SCATTERED SHOWERS
DEVELOPING BY AFTERNOON. THERE WILL ALSO BE SOME SHOWERS FROM KHCO
DOWN THROUGH KBJI THIS MORNING. IN ADDITION NORTHWEST WINDS WILL
BE GUSTY ONCE AGAIN. ALL THESE ELEMENTS SEEM TO BE COVERED WELL SO
UPDATE WILL ONLY ADDRESS LATEST CLOUD AND WIND TRENDS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM CDT TUE MAY 13 2014
THE DEFORMATION BAND PRECIPITATION ACROSS NORTHWEST MINNESOTA WILL
CONTINUE TO LIFT TO THE NORTH...LIKELY OUT OF THE AREA BETWEEN 6AM
AND 8AM. THE BAUDETTE AREA IS REPORTING LIGHT SNOW...AND WILL
ISSUE A SHORT TERM FORECAST TO HANDLE THIS. THE LATEST RAP
GUIDANCE INDICATES 925MB TEMPS AROUND -1C UNTIL THIS PRECIP ENDS
(FOR MAINLY THE LOW REGION...WITH WARMER 925MB TEMPS TO THE WEST
AND SOUTH). THE VSBY HAS NOT DROPPED BELOW 2.5 MILES...AND THESE
SNOWFALL RATES SHOULD EQUATE TO ACCUMULATIONS ONLY ON GRASSY
SURFACES...WITH THE ROADS REMAINING WET (OR JUST A BIT OF SLUSH).
THE MAIN CHALLENGES FOR THE REMAINDER OF THIS FORECAST WILL BE
TEMPERATURES AND SHOWER CHANCES. 00Z MODELS ALL AGREEABLE SO WILL
USE A BLEND. UPPER TROUGH WILL REMAIN ACROSS THE CENTRAL
CONUS...PROPAGATING ONLY SLIGHTLY EASTWARD. THIS WILL PLACE A
500MB COLD POOL OVER THE REGION...AND LEAD TO SCATTERED
INSTABILITY SHOWERS...MAINLY DURING THE AFTERNOON HOURS EACH DAY.
DAYTIME TEMPERATURES WILL STRUGGLE TO REACH 50F...WHILE OVERNIGHT
LOWS WILL BE NEAR OR BELOW THE FREEZING MARK (ESPECIALLY IF
AFTERNOON CU IS ABLE TO DISSIPATE). NORTHWEST WINDS 20 TO 30 MPH
TODAY...SLIGHTLY LESS ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM CDT TUE MAY 13 2014
WEDNESDAY NIGHT-THURSDAY NIGHT...THE UPPER TROUGH WILL CONTINUE TO
SLOWLY PROPAGATE EASTWARD...ALLOWING RIDGING TO MOVE INTO THE
REGION. THIS SHOULD LEAD TO DRY WEATHER. THURSDAY DAYTIME TEMPS
SHOULD BE SLIGHTLY WARMER THAN THE PREVIOUS COUPLE DAYS
CONSIDERING MORE SOLAR WILL OCCUR. THURSDAY MORNING AND FRIDAY
MORNING MIN TEMPS WILL AGAIN BE NEAR OR BELOW THE FREEZING MARK.
FRIDAY-MONDAY...00 UTC GFS/ECMWF ARE IN GOOD AGREEMENT. THE DEEP
ELONGATED TROUGH ACROSS THE NATION/S MID-SECTION WILL FINALLY MOVE
INTO THE WESTERN GREAT LAKES ON FRIDAY AND ACROSS THE EASTERN
GREAT LAKES BY LATE SATURDAY AND SUNDAY. THIS WILL ALLOW RIDGING
AND A WARMER AIR MASS TO MOVE INTO THE NORTHERN PLAINS FOR THE
WEEKEND. SURFACE HIGH PRESSURE WILL RESULT IN DRY CONDITIONS
FRIDAY THROUGH THE WEEKEND WITH MODERATING TEMPERATURES INTO THE
60S BY SATURDAY/SUNDAY. RIDGE AXIS APPEARS TO STALL ACROSS MN
EARLY NEXT WEEK WITH UPSTREAM SOUTHWEST FLOW ALOFT. BOTH GLOBAL
MODELS SUGGEST A LEE-SIDE LOW ON MONDAY WILL RESULT IN INCREASING
CHANCES FOR PRECIP...ALTHOUGH THE GFS IS SLOWER THAN THE ECMWF.
AFTER CUTTING BACK ALL BLEND POPS ON SUNDAY/SUNDAY NIGHT GIVEN
SLOWER MODEL SOLUTIONS...WILL KEEP MID-RANGE CHANCES (30 TO 50
PERCENT) MONDAY/ MONDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 640 AM CDT TUE MAY 13 2014
CONDITIONS RANGE FROM VFR WEST OF THE RED RIVER VALLEY...TO MVFR
WITHIN THE VALLEY...TO IFR EAST OF THE VALLEY. THE GENERAL TREND
WILL BE IMPROVING CONDITIONS THROUGH THE MORNING AND INTO THE
AFTERNOON HOURS. THE MAIN CHALLENGE WILL BE TIMING OF THESE
IMPROVING CONDITIONS (USED THE LATEST RAP AS GUIDANCE). THERE WILL
BE RAIN SHOWERS THIS AFTERNOON...BUT COVERAGE IS EXPECTED TO BE
SCATTERED AND DID NOT INCLUDE WITH THIS ISSUANCE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...GODON
SHORT TERM...TG
LONG TERM...TG/ROGERS
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
640 AM CDT TUE MAY 13 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM CDT TUE MAY 13 2014
THE DEFORMATION BAND PRECIPITATION ACROSS NORTHWEST MINNESOTA WILL
CONTINUE TO LIFT TO THE NORTH...LIKELY OUT OF THE AREA BETWEEN 6AM
AND 8AM. THE BAUDETTE AREA IS REPORTING LIGHT SNOW...AND WILL
ISSUE A SHORT TERM FORECAST TO HANDLE THIS. THE LATEST RAP
GUIDANCE INDICATES 925MB TEMPS AROUND -1C UNTIL THIS PRECIP ENDS
(FOR MAINLY THE LOW REGION...WITH WARMER 925MB TEMPS TO THE WEST
AND SOUTH). THE VSBY HAS NOT DROPPED BELOW 2.5 MILES...AND THESE
SNOWFALL RATES SHOULD EQUATE TO ACCUMULATIONS ONLY ON GRASSY
SURFACES...WITH THE ROADS REMAINING WET (OR JUST A BIT OF SLUSH).
THE MAIN CHALLENGES FOR THE REMAINDER OF THIS FORECAST WILL BE
TEMPERATURES AND SHOWER CHANCES. 00Z MODELS ALL AGREEABLE SO WILL
USE A BLEND. UPPER TROUGH WILL REMAIN ACROSS THE CENTRAL
CONUS...PROPAGATING ONLY SLIGHTLY EASTWARD. THIS WILL PLACE A
500MB COLD POOL OVER THE REGION...AND LEAD TO SCATTERED
INSTABILITY SHOWERS...MAINLY DURING THE AFTERNOON HOURS EACH DAY.
DAYTIME TEMPERATURES WILL STRUGGLE TO REACH 50F...WHILE OVERNIGHT
LOWS WILL BE NEAR OR BELOW THE FREEZING MARK (ESPECIALLY IF
AFTERNOON CU IS ABLE TO DISSIPATE). NORTHWEST WINDS 20 TO 30 MPH
TODAY...SLIGHTLY LESS ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM CDT TUE MAY 13 2014
WEDNESDAY NIGHT-THURSDAY NIGHT...THE UPPER TROUGH WILL CONTINUE TO
SLOWLY PROPAGATE EASTWARD...ALLOWING RIDGING TO MOVE INTO THE
REGION. THIS SHOULD LEAD TO DRY WEATHER. THURSDAY DAYTIME TEMPS
SHOULD BE SLIGHTLY WARMER THAN THE PREVIOUS COUPLE DAYS
CONSIDERING MORE SOLAR WILL OCCUR. THURSDAY MORNING AND FRIDAY
MORNING MIN TEMPS WILL AGAIN BE NEAR OR BELOW THE FREEZING MARK.
FRIDAY-MONDAY...00 UTC GFS/ECMWF ARE IN GOOD AGREEMENT. THE DEEP
ELONGATED TROUGH ACROSS THE NATION/S MID-SECTION WILL FINALLY MOVE
INTO THE WESTERN GREAT LAKES ON FRIDAY AND ACROSS THE EASTERN
GREAT LAKES BY LATE SATURDAY AND SUNDAY. THIS WILL ALLOW RIDGING
AND A WARMER AIR MASS TO MOVE INTO THE NORTHERN PLAINS FOR THE
WEEKEND. SURFACE HIGH PRESSURE WILL RESULT IN DRY CONDITIONS
FRIDAY THROUGH THE WEEKEND WITH MODERATING TEMPERATURES INTO THE
60S BY SATURDAY/SUNDAY. RIDGE AXIS APPEARS TO STALL ACROSS MN
EARLY NEXT WEEK WITH UPSTREAM SOUTHWEST FLOW ALOFT. BOTH GLOBAL
MODELS SUGGEST A LEE-SIDE LOW ON MONDAY WILL RESULT IN INCREASING
CHANCES FOR PRECIP...ALTHOUGH THE GFS IS SLOWER THAN THE ECMWF.
AFTER CUTTING BACK ALL BLEND POPS ON SUNDAY/SUNDAY NIGHT GIVEN
SLOWER MODEL SOLUTIONS...WILL KEEP MID-RANGE CHANCES (30 TO 50
PERCENT) MONDAY/ MONDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 640 AM CDT TUE MAY 13 2014
CONDITIONS RANGE FROM VFR WEST OF THE RED RIVER VALLEY...TO MVFR
WITHIN THE VALLEY...TO IFR EAST OF THE VALLEY. THE GENERAL TREND
WILL BE IMPROVING CONDITIONS THROUGH THE MORNING AND INTO THE
AFTERNOON HOURS. THE MAIN CHALLENGE WILL BE TIMING OF THESE
IMPROVING CONDITIONS (USED THE LATEST RAP AS GUIDANCE). THERE WILL
BE RAIN SHOWERS THIS AFTERNOON...BUT COVERAGE IS EXPECTED TO BE
SCATTERED AND DID NOT INCLUDE WITH THIS ISSUANCE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...TG/ROGERS
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1128 AM EDT TUE MAY 13 2014
.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH MID WEEK. A COLD FRONT WILL
CROSS OUR AREA FROM THE WEST ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1125 AM EDT TUESDAY...SHOWERS ARE BEGINNING TO DEVELOP OVER
THE NC MTNS...WHICH IS RIGHT IN LINE WITH THE EXPECTED TIMING. THE
LATEST RUC BRINGS A WEAK H5 SHORT WAVE ACROSS THE NC MTNS DURING THE
COURSE OF THE AFTERNOON HOURS WHICH MAY HELP TO ORGANIZE CONVECTION
JUST A LITTLE.
AS OF 905 AM EDT TUESDAY...A BAND OF ELEVATED TCU IS WORKING SLOWLY
TO THE NORTH ACROSS THE SOUTHWEST PART OF THE FORECAST AREA. BASED
ON THE CAPPING INVERSION ON THE GSO SOUNDING AND THE RATHER WARM
LLVLS ON THE FFC SOUNDING...I DON/T SEE THESE TOWERS AMOUNTING TO
MUCH AS WE WILL HAVE TO WAIT UNTIL THE EARLY AFTN HOURS FOR SURFACE
BASED CONVECTION TO INITIATE OVER THE MOUNTAINS. THE CURRENT POP
GRIDS ARE DOING A GOOD JOB WITH THIS AND ONLY MINOR TWEAKS WERE
NEEDED.
AS OF DAYBREAK...PATCHY DENSE FOG IN THE NC MOUNTAIN VALLEYS...BUT
OTHERWISE FAIR. THE FOG SHOULD BURN OFF QUICKLY ONCE THE SUN STARTS
TO WARM UP THE BOUNDARY LAYER AROUND 13Z.
OVER THE NEXT 24 HOURS...PERSISTENCE IS THE WORD TO DESCRIBE OUR
EXPECTED WEATHER. THE UPPER RIDGE WILL CONTINUE TO BUILD AND SHIFT
SLOWLY EAST ALONG THE EAST COAST AS EXPECTED...WHICH WILL MAINTAIN
THE BERMUDA HIGH AT THE SURFACE...POKING WESTWARD OVER THE
CAROLINAS. THAT MEANS PRECIP CHANCES THAT FOLLOW CLIMATOLOGY...AND
SEASONALLY WARM TEMPERATURES. ONCE AGAIN...THE AMOUNT OF BUOYANCY
SEEN IN NAM FCST SOUNDINGS LOOKS WAY OVERDONE ON ACCOUNT OF THAT
MODEL KEEPING SURFACE DEWPOINTS UP IN THE UPPER 60S AND LOWER 70S
THIS AFTERNOON...WHEREAS IN REALITY THE DEWPOINT IS MUCH MORE LIKELY
TO MIX OUT DOWN TO THE LOWER 60S OR EVEN UPPER 50S AT THE WARMEST
PART OF THE DAY. DIFFERENTIAL HEATING SHOULD DO THE TRICK AND
PROVIDE FOR SCATTERED COVERAGE OVER THE MTNS...BUT ONCE AGAIN THE
PIEDMONT SHOULD SEE ONLY ISOLATED STORMS AT BEST...A CONCLUSION
WHICH IS ALSO BORNE OUT BY THE CONSENSUS OF THE CONVECTION ALLOWING
MODELS. WILL NOT RULE OUT AN ISOLATED SEVERE STORM OWING TO THE DRY
AIR AT MID LEVELS. ANY STORMS THAT DEVELOP SHOULD DISSIPATE WITH
LOSS OF HEATING THIS EVENING. EXPECT ANOTHER MILD NIGHT. THERE IS
SOME POSSIBILITY OF SCATTERED SHOWERS THAT DEVELOP IN THE IMPROVING
SOUTHERLY FLOW MOVING UP FROM GEORGIA AND ACROSS THE NC MOUNTAINS
TONIGHT...SO THE SLIGHT CHANCE POP WAS KEPT THROUGH THE OVERNIGHT
HOURS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AT 300 AM EDT TUESDAY...HEIGHTS WILL FALL OVER THE SOUTHERN
APPALACHIANS ON WEDNESDAY AND THURSDAY...AS AN UPPER RIDGE
PROGRESSES AWAY FROM THE EAST COAST...AND A HIGH AMPLITUDE UPPER
TROUGH AXIS CROSSES THE MS RIVER VALLEY. BY LATE THURSDAY NIGHT...
THE TROUGH AXIS WILL BE CROSSING THE GULF STATES...AND A STRONG
SHORTWAVE WILL BE CROSSING THE TN RIVER VALLEY.
WEAK HIGH PRESSURE EXTENDING FROM THE ATLANTIC WILL LOSE IS GRIP ON
THE CAROLINAS AND GA ON WEDNESDAY...SUPPLANTED BY A MODEST MOIST
INFLOW FORM THE GULF AND ATLANTIC. MEANWHILE...A SURFACE WAVE WILL
FORM ALONG A COLD FRONT IN THE LOWER MS RIVER VALLEY...MOVING TO W
TN BY LATE IN THE DAY. THE WAVE MOVES INTO THE OH RIVER VALLEY ON
WEDNESDAY NIGHT...WHILE THE TRAILING COLD FRONT APPROACHES GA AND
THE WESTERN CAROLINAS. THE BEST MOIST INFLOW REACHES OUR AREA JUST
AHEAD OF THE FRONT...BEFORE DAWN ON THURSDAY.
THE FRONT MOVES SLOWLY ACROSS THE MOUNTAINS ON THURSDAY...WITH
ANOTHER SURFACE WAVE FORMING OVER THE SAVANNAH RIVER VALLEY. THE
MODELS SHOW ROBUST SHEAR BUT MODEST INSTABILITY AHEAD OF THIS
FRONT...AND A MENTION OF POSSIBLE SEVERE WEATHER WILL BE MAINTAINED
IN THE HAZARDOUS WEATHER OUTLOOK. AN INCREASING SOUTHEASTERLY
UPSLOPE FLOW AND ISENTROPIC UPGLIDE WILL SUPPORT PRECIPITATION
PRODUCTION. SEVERAL INCHES OF RAINFALL ARE POSSIBLE...WITH THE
GREATEST AMOUNTS EXPECTED ALONG THE SOUTH FACING BLUE RIDGE
ESCARPMENT...WHERE NC...GA AND SC MEET. THE COLD FRONT MOVES SLOWLY
ACROSS THE FOOTHILLS AND PIEDMONT ON THURSDAY EVENING...LEAVING OUR
AREA BY FRIDAY MORNING.
TEMPERATURES WILL RUN SIGNIFICANTLY ABOVE NORMAL ON WEDNESDAY AND
WEDNESDAY NIGHT...UNDER THE INFLUENCE OF THE UPPER RIDGE DURING THE
DAY...AND INCREASING CLOUDS AT NIGHT. HIGH TEMPERATURES THURSDAY
WILL BE WELL BELOW NORMAL DUE TO CLOUDS AND PRECIPITATION. LOW
TEMPERATURES THURSDAY NIGHT WILL RUN ONLY SLIGHTLY BELOW NORMAL...AS
COLD ADVECTION WILL HAVE ONLY BEGUN.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AT 300 AM EDT TUESDAY...ON FRIDAY MORNING A CLOSED UPPER LOW WILL BE
OVER WI...WITH A TROUGH EXTENDING SOUTH TO THE GULF COAST...AND A
HIGH AMPLITUDE UPPER RIDGE OVER THE WESTERN ATLANTIC. THE UPPER LOW
DRIFTS NE INTO ONTARIO BY SATURDAY MORNING. THE LOW OPENS UP AND
REACHES THE QUEBEC BORDER BY SUNDAY...WHILE THE DEAMPLIFYING TROUGH
REACHES THE CENTRAL AND SOUTHERN APPALACHIANS. ON MONDAY THE TROUGH
AXIS MOVES TO THE EAST COAST...WHILE AND UPPER RIDGE AMPLIFIES OVER
THE MS RIVER VALLEY. AMPLIFICATION CONTINUES INTO TUESDAY...WITH
LITTLE PROGRESSION...LEADING TO NW FLOW ALOFT OVER GA AND THE
CAROLINAS.
A DEPARTING COLD FRONT WILL BE EAST OF OUR AREA ON FRIDAY...BUT
MOISTURE ASSOCIATED WITH THE CLOSED UPPER LOW MAY EXTEND FAR ENOUGH
SOUTH TO AFFECT THE SOUTHERN APPALACHIANS...WHERE UPSLOPE FLOW
SHOWERS MAY BE POSSIBLE. A MID LEVEL COOL POOL ASSOCIATED WITH THE
UPPER LOW MAY ENHANCE INSTABILITY TO THE POINT WHERE THUNDERSTORMS
WOULD BE FAVORED.
COOL HIGH PRESSURE SETTLES OVER THE SOUTHEAST ON SATURDAY. MOISTURE
ASSOCIATED WITH SHORTWAVE ROUNDING THE BASE OF THE UPPER TROUGH AND
A STATIONARY FRONT IN THE PLAINS AND MID MS RIVER VALLEY IS EXPECTED
TO SPREAD EAST OVER THE SURFACE HIGH...BECOMING MORE NOTICEABLE BY
SUNDAY AND MONDAY. SMALL POPS WILL BE CARRIED AS MOISTURE INCREASES.
TEMPERATURES WILL RUN BELOW NORMAL IN THE WAKE OF THE COLD
FRONT...THEN WILL WARM TO NEAR NORMAL ON MONDAY AS THE COOL AIRMASS
MODIFIES.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
AT KCLT...VFR THROUGH THE PERIOD...WITH WHAT LOOKS LIKE A PERSISTENT
FCST. THERE COULD BE SOME VISIBILITY RESTRICTIONS AROUND THE NC
PIEDMONT FIRST THING...SIMILAR TO MONDAY MORNING...BUT WILL KEEP
THIS OUT OF THE TAF FOR THE TIME BEING. WIND SHOULD BE LIGHT FROM
THE SOUTH WITH SOME INCREASE FROM THE SW BY LATE MORNING. EXPECT CU
TO DEVELOP ONCE AGAIN BY MIDDAY WITH BASES IN THE 050 TO 060 RANGE.
CANNOT RULE OUT AN ISOLATED SHOWER OR THUNDERSTORM IN THE AFTERNOON
AND EVENING...BUT THE CHANCE IS TOO LOW TO MENTION. CONVECTIVE
CLOUDS SHOULD DISSIPATE AGAIN WITH SUNSET AND WIND WILL GO LIGHT S
AGAIN.
ELSEHWERE...PERSISTENCE. SIMILAR TO KCLT. VERY LOW IFR VISIBILITY AT
KAVL SHOULD IMPROVE BY 13Z OR SO. KAND ALSO HAS SOME CHANCE AT MVFR
RESTRICTIONS WITH FOG. AGAIN...THE BEST CHANCE FOR SHOWERS AND
STORMS WILL BE ACROSS THE MOUNTAINS...SO A PROB30 WAS INCLUDED AT
KAVL. OTHER SITES HAVE TOO LOW OF A CHANCE TO MENTION.
OUTLOOK...WEDNESDAY SHOULD BE LARGELY DRY. ON THURSDAY A SLOW MOVING
COLD FRONT WILL YIELD A BETTER CHANCE OF RESTRICTIONS IN PROLONGED
PRECIPITATION AND THUNDERSTORMS. EXPECT VFR AGAIN FRIDAY.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-15Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% MED 77%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% 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...JAT
NEAR TERM...MCAVOY/PM
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...PM
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
642 AM CDT TUE MAY 13 2014
.AVIATION...
COLD SURFACE RIDGE NOSING OVER THE AREA WITH ENOUGH PRESSURE
GRADIENT FOR GUSTY NORTH WINDS THIS MORNING...GRADUALLY BACKING
OFF DURING THE AFTERNOON. DRY LOWER ATMOSPHERE WHILE A SHARP UPPER
LEVEL LOW PRESSURE TROUGH OVER NEW MEXICO WILL MOVE EAST THROUGH
WEST TEXAS LATER TODAY. MID LEVEL MOISTURE AND ENOUGH LIFT AND
INSTABILITY WITH THE UPPER TROUGH THAT A FEW LIGHT SHOWERS MAY
SPIT OUT...MOSTLY EVAPORATING BEFORE REACHING THE GROUND. SKIES
SHOULD TREND CLEAR AND COLDER TONIGHT WITH LIGHT WINDS AS SURFACE
RIDGE DOMINATES. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 355 AM CDT TUE MAY 13 2014/
SHORT TERM...
COLD DRY AIRMASS CONTINUES TO SPREAD INTO THE REGION WITH ENOUGH
SURFACE PRESSURE GRADIENT TO SUPPORT 20-25 MPH WIND SPEEDS AT LEAST
THIS MORNING. A SHARP UPPER TROUGH OVER THE SOUTHERN AND CENTRAL
ROCKIES THIS MORNING WILL EDGE INTO THE AREA DURING THE DAY
SPREADING MODEST DEEP LIFT AND WEAK MID LEVEL INSTABILITY INTO THE
AREA WHILE LOWER ATMOSPHERE WILL MAKE EFFECTIVE SHOWER CHANCES
DIFFICULT. THE WRF/NAM WHICH HAS BEEN QUITE WET TODAY FOR A NUMBER
OF RUNS HAS TRENDED SLIGHTLY DRIER THOUGH HAS RETAINED LIGHT RAIN
SHOWER SIGNAL MAINLY SOUTHEAST ZONES LATER TODAY...WHILE THE
HOUR-BY-HOUR HRRR SOLUTION HAS BEEN TRENDING JUST SLIGHTLY WETTER AS
THESE SOLUTIONS ATTEMPT TO MATCH UP BETTER. WE WILL RETAIN THE
SLIGHT CHANCE OF SHOWERS SOUTHEAST LATER TODAY ALONG WITH A MENTION
OF SPRINKLES THIS MORNING ON THE CAP-ROCK. THESE VERY LIGHT SHOWERS
COULD EXTEND JUST INTO THE EARLY AFTERNOON FOR CENTRAL ZONES BUT
EITHER WAY WE DO NOT EXPECT A BIG DEAL. QUITE COOL AIRMASS TODAY
CLOSE TO 20 DEGREES SHORT OF NORMAL FOR THE DATE AND AS SKIES CLEAR
ON THE BACK SIDE OF THE UPPER TROUGH THIS EVENING ALONG WITH WINDS
AND SURFACE DEWPOINTS ALSO TRENDING LOWER...SHOULD LEAD TO A VERY
CHILLY NIGHT ON THE CAPROCK. WE RETAINED THE PREVIOUS LOW
TEMPERATURE FORECAST FOR TONIGHT AND ADDED A FREEZE WATCH FOR OUR
WEST/NORTHWESTERN 5 COUNTIES. RMCQUEEN
LONG TERM...
COOLER THAN AVERAGE TEMPERATURES WILL STICK AROUND THROUGH
WEDNESDAY AS WE WILL REMAIN UNDER THE INFLUENCE OF THE UPPER LEVEL
TROUGH MOVING OFF EAST OF THE AREA. A RIDGE OVER THE WEST COAST
WILL DEAMPLIFY AS IT MOVES THROUGH THE ROCKIES LATER THIS WEEK.
THIS WILL STILL LEAD TO RISING HEIGHTS AND INCREASING TEMPERATURES
THROUGH EARLY NEXT WEEK.
A WEAK FRONT WILL PASS THROUGH THE AREA LATE THURSDAY GIVING WAY
TO UPSLOPE WINDS ON FRIDAY. THE ECMWF HAS CONSISTENTLY BEEN
DEPICTING LIGHT QPF VALUES ON FRIDAY MORNING UNDER THIS UPSLOPE
FLOW. IT DEVELOPS WEAK MOIST ISENTROPIC UPGLIDE ALTHOUGH THE ECMWF
DIFFERS WITH THE GFS IN REGARDS TO THE MOIST PORTION. LOW STRATUS
MAY BE THE ONLY RESULT OF THIS LOW LEVEL FLOW. FROM THE EARLY
PORTION TO THE MIDDLE OF NEXT WEEK A LOW AMPLITUDE RIDGE WILL
BUILD OVER THE PLAINS AND MIDWEST AS A TROUGH FORMS NEAR THE
INTERMOUNTAIN WEST. THIS MAY PROVIDE AN OPPORTUNITY FOR
THUNDERSTORMS WITH LOW LEVEL MOISTURE RETURNING UNDER THIS TYPE OF
PATTERN.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 60 32 67 39 76 / 10 0 0 0 0
TULIA 62 36 67 39 76 / 10 0 0 0 0
PLAINVIEW 62 37 67 40 77 / 10 0 0 0 0
LEVELLAND 63 37 68 40 78 / 10 0 0 0 0
LUBBOCK 64 38 69 43 78 / 10 10 0 0 0
DENVER CITY 63 37 69 41 78 / 10 10 0 0 0
BROWNFIELD 63 37 69 41 78 / 10 10 0 0 0
CHILDRESS 67 43 73 44 81 / 10 10 0 0 0
SPUR 64 39 71 43 80 / 20 10 0 0 0
ASPERMONT 65 44 72 44 81 / 20 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR THE
FOLLOWING ZONES: TXZ021-022-027-028-033.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
310 PM CDT TUE MAY 13 2014
.SYNOPSIS...
ISSUED AT 309 PM CDT TUE MAY 13 2014
TEMPERATURES WERE RUNNING 25 TO 30 DEGREES COLDER THAN 24 HOURS AGO
ACROSS THE FORECAST AREA THIS AFTERNOON IN THE WAKE OF THE STRONG
FRONT THAT PUSHED THROUGH OVERNIGHT. AT 19Z...THE SHARP COLD FRONT
WAS WELL TO THE EAST FROM LOWER MI SOUTH TO LA. AN EXPANSIVE POST
FRONTAL STRATUS DECK EXTENDED WEST INTO CENTRAL IA. THE CLOUDS...
COMBINED WITH LOW LEVEL COLD ADVECTION ON NW WINDS...WAS LIMITING
TEMPERATURES TO THE LOWER TO MID 50S. RADAR MOSAIC INDICATED A FEW
DEVELOPING LIGHT SHOWERS LIKELY ALONG THE LAGGING 850 MB FRONT OVER
W CENTRAL IL NEAR MACOMB. 12Z UPPER AIR ANALYSIS SHOWED AN UPPER
TROUGH REACHING FROM A LOW OVER SOUTHERN CANADA TO A SEPARATE
SOUTHERN STREAM VORTEX EMBEDDED IN THE LARGER TROUGH AXIS NEAR THE
OK PANHANDLE. UNSEASONABLY COLD TEMPERATURES AROUND ZERO TO SEVERAL
DEGREES BELOW AT 850 MB WERE FOUND BEHIND THE FRONT IN THE NW FLOW
ACROSS THE DAKOTAS INTO MN AND NW IA.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 309 PM CDT TUE MAY 13 2014
MAIN FOCUS IS ON COOL TEMPERATURES AND POTENTIAL FOR LIGHT
PRECIPITATION. TONIGHT...A DEVELOPING MORE ANTICYCLONIC LOW LEVEL
FLOW...BACKED BY RAP LOW LEVEL RH FIELDS INDICATES THE STRATUS DECK
GRADUALLY CLEARING FROM WEST TO EAST FROM LATE AFTERNOON THROUGH MID
EVENING. AT THE SAME TIME...MID AND HIGH LEVEL MOISTURE IN THE SW
WITH SUPPORT FROM EMBEDDED VORT MAXIMA WILL KEEP HIGH LEVEL CLOUD
COVER IN PLACE. THIS CLOUD COVER SHOULD ELIMINATE THE THREAT OF
FREEZING TEMPERATURE OR FROST TONIGHT...BUT STILL LEAD TO WELL BELOW
NORMAL TEMPERATURES AS THE 850 MB THERMAL TROUGH PASSING OVERHEAD
TOWARD MORNING SENDS TEMPERATURES AT THAT LEVEL CLOSE TO ZERO C.
HAVE KEPT MINS NEAR TO BELOW THE LOW END OF GUIDANCE FROM THE UPPER
30S NW TO MID 40S SE. DIURNALLY ENHANCE SHOWERS OVER THE FAR EAST
AND SOUTHEAST SHOULD DISSIPATE BY THIS EVENING.
WEDNESDAY...THE UPPER LOW OVER THE SOUTHERN PLAINS GETS PULLED
NORTHEAST...SENDING LIFT INTO NORTHERN IL BY AFTERNOON. THIS...ALONG
WITH A FAVORABLE RIGHT ENTRANCE REGION OF THE UPPER JET LIFTING N-NE
INTO EASTERN CANADA WILL SUPPORT SHOWERS MAINLY EAST OF THE MS RIVER
IN THE AFTERNOON. WILL KEEP HIGH CHANCE POPS GOING FOR WHAT SHOULD
BE A VERY LOW QPF EVENT BASED ON LIMITED MOISTURE AND A DRY LAYER IN
THE LOW LEVELS IN FORECAST SOUNDINGS. IN THE SAME AIRMASS AS
TODAY...TEMPERATURES SHOULD BE LIMITED TO THE 50S IN THE THICKEST
CLOUD COVER AND DEVELOPING SHOWERS ACROSS THE EAST...WHILE HIGHER
CLOUD COVER AND DRY AIR MAY ALLOW AREAS WEST OF THE MS RIVER TO
REACH THE UPPER 50S TO PERHAPS LOWER 60S. OVERALL...MODEL GUIDANCE
MUCH LIKE TODAY LOOKED A BIT TOO OPTIMISTIC IN THE AMOUNT OF WARMING
IN THIS AIRMASS AND HAVE TRENDED NEAR TO BELOW THE COOLEST NUMBERS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 309 PM CDT TUE MAY 13 2014
FORECAST FOCUS ON BELOW NORMAL TEMPERATURES THROUGH THE EXTENDED.
WEDNESDAY NIGHT THROUGH FRIDAY...STRONG ENERGY IN THE SOUTHERN
STREAM PHASES WITH THE NORTHERN STREAM TO CARVE OUT A MAJOR TROUGH
IN THE MIDDLE OF THE COUNTRY. CYCLOGENESIS DEVELOPS IN THE LOWER MS
VALLEY ON WEDNESDAY AND RIDES UP A STALLED FRONT INTO THE OHIO
VALLEY AND EASTERN GREAT LAKES BY THURSDAY. THIS WILL DUMP CHILLY
AIR INTO MUCH OF THE MIDWEST WITH BELOW TO WELL BELOW NORMAL
TEMPERATURES THE REMAINDER OF THIS WEEK INTO THE WEEKEND. 850 MB
TEMPERATURES ARE PROGGED TO ABOUT -2C OVER THE CWA. MODELS SIMILAR
IN KEEPING THE BULK OF THE RAIN...TIED TO THE SURFACE LOW MOVING
INTO THE OHIO VALLEY...TO THE EAST OF THE DVN CWA. I WILL CONTINUE
WITH CHANCE POPS IN THE FORM OF SCATTERED SHOWERS ESPECIALLY
THURSDAY AND FRIDAY DURING THE AFTERNOON AND EARLY EVENING. THIS
WILL BE INSTABILITY SHOWERS DUE TO THE COLD AIR ALOFT ASSOCIATED
WITH THE VERY IMPRESSIVE (FOR MAY) DEEP TROUGH. EXTENSIVE CLOUD
COVER THE REMAINDER OF THIS WEEK WILL KEEP AFTERNOON MAXIMUM
TEMPERATURES MAINLY IN THE 50S...WITH LOWS IN THE UPPER 30S TO MID
40S. THE CLOUD COVER WILL PREVENT ANY FROST FORMATION THIS WORK WEEK.
FRIDAY NIGHT THROUGH THE WEEKEND...AT THIS POINT IN THE GAME THE
FAVORED TIME FOR AT LEAST SCATTERED FROST AND POSSIBLE HEADLINES
APPEAR TO BE FRIDAY NIGHT/EARLY SATURDAY MORNING. MODELS SUGGEST A
HIGH PRESSURE RIDGE SETTLING INTO THE REGION WITH CLEAR SKIES AND
LIGHT WINDS ALLOWING FOR GOOD RADIATIONAL COOLING. LOW TEMPERATURES
SHOULD DIP INTO THE 30S BUT EXACT NUMBERS REMAIN TO BE SEEN.
DEEP TROUGH BEGINS TO SHIFT TO THE EAST OVER THE WEEKEND ALLOWING
FOR A MODERATION IN TEMPERATURES AND RATHER PLEASANT WEATHER.
MAXIMUM TEMPERATURES SHOULD PUSH INTO THE 60S WITH LOWS IN THE 40S.
EARLY NEXT WEEK...THE 12Z ECMWF HAS BACKED OFF ON SURGING WARMER AIR
INTO THE CWA...AND A MORE ACTIVE PATTERN...PUSHING IT OFF UNTIL THE
MIDDLE AND END OF NEXT WEEK. ECMWF/GFS WANT TO HANG ON TO THE
TROUGH IN THE EAST A BIT LONGER KEEPING TEMPERATURES A BIT BELOW
NORMAL AND HOLDING OFF THE RAIN. WE WILL SEE.
21
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1234 PM CDT TUE MAY 13 2014
A LARGE AREA OF LOW CLOUDS WITH MVFR CIGS REMAINS IN PLACE OVER IL
AND MUCH OF IA IN THE WAKE OF A STRONG COLD FRONT REACHING FROM
THE GREAT LAKES TO LOWER MS VALLEY. THESE CLOUDS WILL BE SLOW TO
LIFT AND BREAK UP AND LATEST FORECASTS WILL KEEP CIGS AT AN MVFR
THRESHOLD AROUND 2500 TO 3000 FT UNTIL ABOUT 00Z...THEN LIFT AND
BECOME BROKEN AROUND 4000 FT AFTER SUNSET. CONDITIONS WILL BE
PREDOMINANTLY VFR TONIGHT INTO WEDNESDAY MORNING. BRISK NW WINDS
FROM 10 TO 20 MPH WILL DIMINISH TO LESS THAN 10 KTS OVERNIGHT AND
BECOME MORE NORTHERLY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...11
SHORT TERM...11
LONG TERM...21
AVIATION...11
AREA FORECAST DISCUSSION
NWS DES MOINES IA...ISSUED BY NATIONAL WEATHER
SERVICE OMAHA/VALLEY NE
155 PM CDT TUE MAY 13 2014
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
ISSUED AT 332 AM CDT TUE MAY 13 2014
MAIN FORECAST CONCERN TODAY WAS WITH MAX TEMPS AND CLOUD COVER.
AREA OF LOW PRESSURE LOCATED OVER LAKE SUPERIOR WILL CONTINUE TO
DRAG NORTHEAST INTO ONTARIO TODAY. DECENT CAA WILL PERSISTS
THROUGHOUT THE DAY DUE TO PRESSURE GRADIENT AIDED BY INCREASING
MIXING DURING THE AFTERNOON. LOW LEVEL MOISTURE GRADUALLY ERODES
FROM SOUTHWEST TO CENTRAL IOWA AND SHOULD SEE CLOUD COVER THIN OUT
AND LIFT IN THIS FASHION DURING THE AFTERNOON. HOWEVER...A
SECONDARY LOBE OF MID-LEVEL THETA-E ADVECTION WRAPS AROUND THE
SURFACE LOW LATE IN THE DAY AND LOOKS TO REINFORCE THE CLOUD COVER
OVER NORTHERN IOWA. THE 13.05Z HRRR AND 13.03Z HOPWRF ARE IN FAIR
AGREEMENT WITH THE PREVIOUS THINKING OF CLOUD COVER TRENDS...BUT
THINKING ARE SLIGHTLY TOO QUICK IN ERODING. WENT SLIGHTLY BELOW
MOS GUIDANCE FOR MAX TEMPS TODAY WITH THE CLOUD COVER AND CAA.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 332 AM CDT TUE MAY 13 2014
AFTER A WARM AND ACTIVE PERIOD THE PAST WEEK...WE WILL TURN AROUND
AND GO BACK TO A RELATIVELY COOL AND MOSTLY QUIET PERIOD FOR THE
NEXT 4 TO 5 DAYS. THOUGH NOT RAIN FREE...CHANCES FOR ANY ORGANIZED
SEVERE WEATHER WILL BE SLIM TO NONE. WITH THE RECENT RAINFALL SOME
RIVERS ARE RISING NOW BUT REMAINING IN BANK. THE H500 LOW NOW
OVER SOUTHERN CANADA WILL WOBBLE NORTHEAST WEDNESDAY WITH A
SECONDARY VORT MAX DIGGING SOUTHEAST ON THE BACK SIDE OF THE
SYSTEM OVER THE NEXT TWO DAYS. THIS WILL RESULT IN ANOTHER COLD
FRONT AND COLD POOL DROPPING SOUTH INTO MN AND IOWA BY LATE
WEDNESDAY NIGHT AND THURSDAY. MEANWHILE...TONIGHT SHOULD REMAIN
GENERALLY CLEAR TO PARTLY CLOUDY AS A WEAK RIDGE OF HIGH PRESSURE
SETTLES INTO THE AREA. TEMPS WILL BE QUITE COOL WITH THICKNESS
DROPPING TO 540 NORTH TO ABOUT 546 SOUTH. LOWS SHOULD RANGE FROM
THE MID TO UPPER 30S NORTH TO THE LOWER 40S SOUTH. BY EARLY
WEDNESDAY A WEAK UPSTREAM WAVE OVER THE NORTHERN PLAINS WILL DROP
SOUTH TOWARD IOWA...BRIEFLY ENHANCING WESTERLY FLOW ALOFT AND
INCREASING WARM AIR ADVECTION THROUGH THE AFTERNOON HOURS. THIS
WILL LIKELY SPREAD A CLOUDS ACROSS THE REGION WITH A FEW SHOWERS
AND ISOLATED THUNDERSTORMS NORTHWEST BY AFTERNOON. TEMPS WILL
RESPOND AND REACH THE LOWER 60S NORTH TO THE MID 60S CENTRAL AND
WEST. AS THE WEAK SFC BOUNDARY DROPS SOUTH THROUGH THE AREA WED
NIGHT IN RESPONSE TO THE STRENGTHENING NW FLOW ALOFT...CLOUDS WILL
OVERSPREAD THE REGION WED NIGHT AND CONTINUE INTO THURSDAY. THE
H500 COLD POOL THURSDAY IS BEING HANDLED DIFFERENTLY BY THE
GEM/EURO MODEL VS THE GFS/NAM. THE GEM/EURO ARE STRONGER AND
ESSENTIALLY PRODUCE A CUTOFF LOW OVER THE GREAT LAKES WHILE THE
GFS/NAM ARE KEEPING A WEAKER...OPEN WAVE OVER THE AREA.
CLIMATOLOGY WOULD FAVOR THE COLDER...MORE CLOSED SOLUTION SO WILL
TREND TOWARD COLDER...CLOUDIER...AND MORE SHOWERY FOR THURSDAY. IN
FACT LAPSE RATES REMAIN STEEP ENOUGH WITH THE COLD POOL ON
THURSDAY TO PRODUCE LATE MORNING THROUGH AFTERNOON THUNDERSTORMS.
WITH FREEZING LEVELS AS LOW AS FORECAST...MAY SEE SOME SMALL
HAIL/SLEET OR VERY COLD RAIN WITH A FEW OF THE STORMS THURSDAY IF
DOWNDRAFTS BECOME STRONG ENOUGH. VERY LITTLE CHANGE IS EXPECTED
THROUGH FRIDAY WITH NW FLOW CONTINUING WITH THE H500 LOW IN THE
AREA. ADDITIONAL CHANCES FOR ISO THUNDER ARE AGAIN POSSIBLE FRIDAY
AFTERNOON AS DAYTIME HEATING INCREASES INSTABILITY. TEMPS THURSDAY
AND FRIDAY WILL STRUGGLE TO REACH THE MID 50S NORTH TO UPPER
50S/LOWER 60S SOUTH AS CLOUDS BUILD DURING THE DAYTIME HOURS. THE
UPPER LEVEL LOW WILL FINALLY PULL EAST BY SATURDAY WITH A
FLATTENING OF THE FLOW TO OUR WEST. THIS WILL ALLOW FOR WARM AIR
ADVECTION TO INCREASE ACROSS IOWA INTO THE WEEKEND. WITH A GREAT
LAKES HIGH STILL HOLDING ON SUNDAY MAINLY DRY CONDITIONS ARE
EXPECTED THROUGH THE WEEKEND. THOUGH UNCERTAINLY ON TIMING IS
INCREASING TOWARD THE END OF THE FORECAST...A LARGE SCALE TROUGH
WILL ENTER THE PACNW SUNDAY AND INCREASE THETAE ADVECTION ACROSS
THE PLAINS LATE ON SUNDAY INTO MONDAY. THIS SHOULD INCREASE TEMPS
AND CHANCES FOR THUNDER INTO MONDAY. TRENDS OF THE GEM/EURO
CONFIRM INCREASING MOISTURE BY THE END OF THE WEEKEND AND
ESPECIALLY ON MONDAY WITH MORE ORGANIZED CONVECTION. HIGHS SUNDAY
WILL REACH 70 WITH LOWER 70S ON MONDAY. NEXT WEEK LOOKS MUCH MORE
ACTIVE ONCE AGAIN.
&&
.AVIATION...13/12Z
ISSUED AT 155 PM CDT TUE MAY 13 2014
MVFR CIGS WILL PERSIST THROUGH MUCH OF THE MORNING HOURS BEFORE
MIXING HELPS TO LIFT THE CIGS BY AROUND MIDDAY. POTENTIAL MCW TO ALO
MVFR CIGS COULD LINGER FURTHER INTO THE AFTERNOON HOURS...SO DID
DELAY VFR CIGS ABOUT 3 HOURS. OTHERWISE...CAA PERSIST INTO THE
EVENING BEFORE HIGH MOVES OVERHEAD AND ALLOWS WINDS TO BECOME LIGHT
AND VARIABLE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...REV
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
358 PM CDT Tue May 13 2014
...Updated for long term discussion...
.UPDATE...
ISSUED AT 224 PM CDT TUE MAY 13 2014
In areas of forecast lows from 33 to 36F, went with an NPW Frost
Advisory tonight, same time as the Freeze Warning, 09Z-13Z.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 106 PM CDT TUE MAY 13 2014
A large scale high pressure system over Utah and Wyoming will move
just slightly southeast tonight, bringing decreasing winds and clear
skies. There is a swath of mid-level clouds in the 080 range across
Western Kansas this afternoon. With the suppression from the
southeastward progressing surface high pressure, skies will become
clear by midnight. Winds will decrease from the current breezy
conditions to around 10 MPH by 00z, and then even lower to 06-07
MPH after midnight. For this reason, I lowered temperatures in
the west to just below freezing, and posted another NPW Freeze
Warning for the 09Z to 13Z time range, basically west of a Scott
City to Hugoton line. The NAM and RUC models both support these
sub-freezing temperatures out west.
As for Wednesday, I made a few slight changes. There is an upper
level trough dragging through, with better dynamics to our north.
But, we could see a few sprinkles/virga Tuesday afternoon into
Tuesday evening. Chose to go with scattered sprinkles since the
only support for any precipitation will be from the upper trough
crossing, with no significant lower level moisture, and only in our
northern 1/3rd of the CWA. Wednesday should be slightly warmer
than today, mainly based on the surface high pressure segmenting
into two high pressure centers, one in the Wyoming and the other
over Oklahoma. Surface winds Wednesday will start out light, then
be from the northwest at 10 to 20 mph. This will not be a strong
down slope affect, but enough to push maximum temperatures upward
a couple to few degrees warmer than today.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 346 PM CDT TUE MAY 13 2014
A large upper level trough will develop over the upper midwest by
Thursday night as northern and southern stream troughs progress
eastward and merge together. Surface high pressure will generally
be situated across the central plains on the back side of the
trough. This will lead to fairly cool weather with highs in the
60s to near 70 Thursday. A few sprinkles are possible Thursday
afternoon given the cold upper level temperatures, but low level
moisture will be a limiting factor. A few showers are possible by
Friday, particularly in far western Kansas given the lack of
capping and where temperatures may reach the upper 70s. Saturday
night still looks cool as surface high pressure builds into
western Kansas. Lows could be cooler than currently forecasted,
with some upper 30s possible along interstate 70.
By Saturday and Sunday, the flow will become more westerly at mid
and high levels, which will allow for lee troughing and some
moisture return into western Kansas. There is a slight chance of
showers and thunderstorms through this period, but no severe weather
or heavy rainfall is expected. High temperatures should remain
mainly in the 70s.
An upper level trough will develop near the West Coast by Monday and
then progress into the Rockies by Tuesday and Wednesday. Low level
moisture will continue to increase so that surface based CAPE will
be higher each day. Low level moisture return from the Gulf of
Mexico is progged to be rather limited even early next week since
the prior cold front late this week will have shunted the low
level moisture into the tropics. So instead of high CAPE ahead of
a dryline and along a weak frontal boundary, instability will be
rather marginal. However, given the presence of boundaries and at
least marginal to moderate CAPE values, thunderstorms cannot be
ruled out through Wednesday. Temperatures will be warming early
next week as well, with the warmest readings in far southwest
Kansas in the 90s, and cooler 80s along interstate 70.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1152 AM CDT TUE MAY 13 2014
The Flight category will be VFR through the next 24 hours. It will
be breezy to start off this TAF period, with north winds of
20G30KT through 00Z. North winds will settle to the 10KT range
then, and fall even farther from the northwest at 06-07KT after
06z. Furthermore, there will be sct to bkn 070-080 mid level
clouds around through after sunset, then they will begin to sct
out to the few sky category.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 37 66 39 69 / 0 0 0 20
GCK 33 65 38 69 / 0 10 10 20
EHA 31 65 39 72 / 0 0 0 10
LBL 34 67 39 71 / 0 0 0 10
HYS 34 67 40 65 / 0 10 10 20
P28 40 70 43 69 / 0 0 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING from 4 AM CDT /3 AM MDT/ to 8 AM CDT /7 AM MDT/
Wednesday FOR KSZ043-044-061>063-074-075-084.
FROST ADVISORY from 4 AM to 8 AM CDT Wednesday FOR KSZ030-031-
045-046-064-076-077-085-086.
&&
$$
UPDATE...Burke
SHORT TERM...Burke
LONG TERM...Finch
AVIATION...Burke
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
228 PM CDT Tue May 13 2014
...Updated to add a Frost Advisory just east of the Freeze Warning...
.UPDATE...
ISSUED AT 224 PM CDT TUE MAY 13 2014
In areas of forecast lows from 33 to 36F, went with an NPW Frost
Advisory tonight, same time as the Freeze Warning, 09Z-13Z.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 106 PM CDT TUE MAY 13 2014
A large scale high pressure system over Utah and Wyoming will move
just slightly southeast tonight, bringing decreasing winds and clear
skies. There is a swath of mid-level clouds in the 080 range across
Western Kansas this afternoon. With the suppression from the
southeastward progressing surface high pressure, skies will become
clear by midnight. Winds will decrease from the current breezy
conditions to around 10 MPH by 00z, and then even lower to 06-07
MPH after midnight. For this reason, I lowered temperatures in
the west to just below freezing, and posted another NPW Freeze
Warning for the 09Z to 13Z time range, basically west of a Scott
City to Hugoton line. The NAM and RUC models both support these
sub-freezing temperatures out west.
As for Wednesday, I made a few slight changes. There is an upper
level trough dragging through, with better dynamics to our north.
But, we could see a few sprinkles/virga Tuesday afternoon into
Tuesday evening. Chose to go with scattered sprinkles since the
only support for any precipitation will be from the upper trough
crossing, with no significant lower level moisture, and only in our
northern 1/3rd of the CWA. Wednesday should be slightly warmer
than today, mainly based on the surface high pressure segmenting
into two high pressure centers, one in the Wyoming and the other
over Oklahoma. Surface winds Wednesday will start out light, then
be from the northwest at 10 to 20 mph. This will not be a strong
down slope affect, but enough to push maximum temperatures upward
a couple to few degrees warmer than today.
.LONG TERM...(Wednesday through Monday)
ISSUED AT 337 AM CDT TUE MAY 13 2014
Medium range models indicate an elongated upper level trough of low
pressure transitioning slowly eastward across the Central Plains
Wednesday giving way to a northwesterly flow aloft across the
Western High Plains by Wednesday night. Dry conditions are likely
through at least early Thursday as much drier air infiltrates the
lower and mid levels. There is an outside chance for a few high
based showers late Thursday as an H5 vort lobe swings southeastward
across the Northern Plains into the Central Plains on the back side
of the departing large scale trough axis. Associated with this
feature will be a marginally intensified upper level jet
increasing dynamic support aloft. Along with the help of some
moisture return in the lower/mid levels as indicated by GFS/ECMWF
model soundings, a few light showers will be possible across
central and portions of southwest Kansas Thursday afternoon/evening.
A similar setup will exist Friday with the additional help of an
easterly upslope flow as surface low pressure develops generally
across southeastern Colorado and the western panhandle of
Oklahoma.
Temperatures will gradually warm from Tuesday into Wednesday even as
surface high pressure remains settled across the Colorado Rockies.
This will allow a low level northwesterly flow to persist across the
high plains of western Kansas. With marginally warmer air moving
into the area combined with the help of some downsloping, expect
highs well up into the 60s(F) to near 70F Wednesday afternoon. The
gradual warming trend will continue through the weekend as the
northwesterly flow aloft becomes more zonal across the Western
High Plains.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1152 AM CDT TUE MAY 13 2014
The Flight category will be VFR through the next 24 hours. It will
be breezy to start off this TAF period, with north winds of
20G30KT through 00Z. North winds will settle to the 10KT range
then, and fall even farther from the northwest at 06-07KT after
06z. Furthermore, there will be sct to bkn 070-080 mid level
clouds around through after sunset, then they will begin to sct
out to the few sky category.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 37 66 39 69 / 0 0 0 20
GCK 33 65 38 69 / 0 10 10 20
EHA 31 65 39 72 / 0 0 0 10
LBL 34 67 39 71 / 0 0 0 10
HYS 34 67 40 65 / 0 10 10 20
P28 40 70 43 69 / 0 0 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING from 4 AM CDT /3 AM MDT/ to 8 AM CDT /7 AM MDT/
Wednesday FOR KSZ043-044-061>063-074-075-084.
FROST ADVISORY from 4 AM to 8 AM CDT Wednesday FOR KSZ030-031-
045-046-064-076-077-085-086.
&&
$$
UPDATE...Burke
SHORT TERM...Burke
LONG TERM...JJohnson
AVIATION...Burke
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
120 PM CDT Tue May 13 2014
...Updated for the short term forecast...
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 106 PM CDT TUE MAY 13 2014
A large scale high pressure system over Utah and Wyoming will move
just slightly southeast tonight, bringing decreasing winds and clear
skies. There is a swath of mid-level clouds in the 080 range across
Western Kansas this afternoon. With the suppression from the
southeastward progressing surface high pressure, skies will become
clear by midnight. Winds will decrease from the current breezy
conditions to around 10 MPH by 00z, and then even lower to 06-07
MPH after midnight. For this reason, I lowered temperatures in
the west to just below freezing, and posted another NPW Freeze
Warning for the 09Z to 13Z time range, basically west of a Scott
City to Hugoton line. The NAM and RUC models both support these
sub-freezing temperatures out west.
As for Wednesday, I made a few slight changes. There is an upper
level trough dragging through, with better dynamics to our north.
But, we could see a few sprinkles/virga Tuesday afternoon into
Tuesday evening. Chose to go with scattered sprinkles since the
only support for any precipitation will be from the upper trough
crossing, with no significant lower level moisture, and only in our
northern 1/3rd of the CWA. Wednesday should be slightly warmer
than today, mainly based on the surface high pressure segmenting
into two high pressure centers, one in the Wyoming and the other
over Oklahoma. Surface winds Wednesday will start out light, then
be from the northwest at 10 to 20 mph. This will not be a strong
down slope affect, but enough to push maximum temperatures upward
a couple to few degrees warmer than today.
.LONG TERM...(Wednesday through Monday)
ISSUED AT 337 AM CDT TUE MAY 13 2014
Medium range models indicate an elongated upper level trough of low
pressure transitioning slowly eastward across the Central Plains
Wednesday giving way to a northwesterly flow aloft across the
Western High Plains by Wednesday night. Dry conditions are likely
through at least early Thursday as much drier air infiltrates the
lower and mid levels. There is an outside chance for a few high
based showers late Thursday as an H5 vort lobe swings southeastward
across the Northern Plains into the Central Plains on the back side
of the departing large scale trough axis. Associated with this
feature will be a marginally intensified upper level jet
increasing dynamic support aloft. Along with the help of some
moisture return in the lower/mid levels as indicated by GFS/ECMWF
model soundings, a few light showers will be possible across
central and portions of southwest Kansas Thursday afternoon/evening.
A similar setup will exist Friday with the additional help of an
easterly upslope flow as surface low pressure develops generally
across southeastern Colorado and the western panhandle of
Oklahoma.
Temperatures will gradually warm from Tuesday into Wednesday even as
surface high pressure remains settled across the Colorado Rockies.
This will allow a low level northwesterly flow to persist across the
high plains of western Kansas. With marginally warmer air moving
into the area combined with the help of some downsloping, expect
highs well up into the 60s(F) to near 70F Wednesday afternoon. The
gradual warming trend will continue through the weekend as the
northwesterly flow aloft becomes more zonal across the Western
High Plains.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1152 AM CDT TUE MAY 13 2014
The Flight category will be VFR through the next 24 hours. It will
be breezy to start off this TAF period, with north winds of
20G30KT through 00Z. North winds will settle to the 10KT range
then, and fall even farther from the northwest at 06-07KT after
06z. Furthermore, there will be sct to bkn 070-080 mid level
clouds around through after sunset, then they will begin to sct
out to the few sky category.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 37 66 39 70 / 0 0 0 20
GCK 33 65 38 70 / 0 10 0 20
EHA 31 65 39 74 / 0 0 0 10
LBL 34 67 39 73 / 0 0 0 10
HYS 34 67 40 65 / 0 10 0 20
P28 40 70 43 72 / 0 0 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING from 4 AM CDT /3 AM MDT/ to 8 AM CDT /7 AM MDT/
Wednesday FOR KSZ043-044-061>063-074-075-084.
&&
$$
SHORT TERM...Burke
LONG TERM...JJohnson
AVIATION...Burke
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
201 PM EDT TUE MAY 13 2014
.UPDATE...
ISSUED AT 155 PM EDT TUE MAY 13 2014
ISOLATED CONVECTION HAS DEVELOPED ACROSS MAINLY WESTERN PARTS OF THE
AREA. COVERAGE OF CONVECTION SHOULD GRADUALLY DECREASE THROUGH
SUNSET. THE HOURLY GRIDS HAVE BEEN UPDATED BASED ON THIS AND RECENT
TRENDS IN OBSERVATIONS...RADAR AND SATELLITE IMAGERY. THIS LED TO
SLIGHTLY LONGER PERIOD OF SLIGHT CHANCE IN ALL AREAS.
UPDATE ISSUED AT 1040 AM EDT TUE MAY 13 2014
HOURLY GRIDS WERE UPDATED BASED ON RECENT OBSERVATION AND SATELLITE TRENDS.
THE REGION CONTINUES TO RESIDE ON THE WESTERN EDGE OF A RIDGE OF HIGH
PRESSURE CENTERED OFF THE SOUTHEAST US COAST. THE RIDGE AXIS WILL
SHIFT FURTHER TO THE NORTH AND EAST TODAY WITH HEIGHTS EXPECTED TO
LOWER A BIT BY THIS EVENING...AND THIS WILL ALLOW THE TROUGH OVER
THE MIDDLE OF THE COUNTRY TO GRADUALLY SHIFT EAST. SHORT TERM MODELS
SUCH AS THE HRRR SUGGEST ISOLATED TO PERHAPS SCATTERED CONVECTION
IMITATING OVER THE NORTHERN CUMBERLAND PLATEAU OF TN OR ACROSS THE
SOUTHERN PORTION OF THE DANIEL BOONE NF AND BIG SOUTH FORK NRRA
AROUND OR SHORTLY AFTERNOON NOON WITH FURTHER DEVELOPMENT EAST INTO
THE COALFIELDS/VA BORDER COUNTIES SHORTLY THEREAFTER. OUTFLOWS FROM
THIS PULSE TYPE CONVECTION SHOULD LEAD TO ANOTHER COUPLE GENERATIONS
OF ISOLATED CONVECTION THROUGH EARLY IN THE EVENING.
UPDATE ISSUED AT 655 AM EDT TUE MAY 13 2014
FORECAST IS ON TRACK THIS MORNING...SO NO UPDATE PLANNED AS OF RIGHT
NOW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 306 AM EDT TUE MAY 13 2014
STRONG RIDGING CONTINUES TO RESIDE OVER THE EAST COAST WITH A
BAROCLINIC ZONE LYING ACROSS THE CENTRAL PLAINS. EASTERN KENTUCKY
WILL CONTINUE TO REMAIN IN NO MANS LAND WITH RESPECT TO THESE TWO
SYSTEMS TODAY AND TONIGHT. THUS...IT LOOKS LIKE MORE OF THE SAME
TODAY WITH HIGHS SURGING INTO THE 80S. MUCH LIKE THE PAST FEW DAYS A
STRAY SHOWER OR THUNDERSTORM COULD DEVELOP JUST ABOUT ANYWHERE DURING
THE MID TO LATE AFTERNOON HOURS. AS INSTABILITY WANES THIS
EVENING...WE SHOULD SEE ANOTHER QUIET NIGHT WITH LOWS INTO THE UPPER
50S IN THE VALLEYS AND UPPER 60S ON THE RIDGES.
BY WEDNESDAY...THINGS WILL FINALLY START TURNING MORE ACTIVE TO OUR
WEST AS A SOUTHERN STREAM WAVE PHASES WITH A NORTHERN STREAM
WAVE...GENERATING A SURFACE LOW OVER ARKANSAS. STILL SOME UNCERTAINTY
ON HOW QUICKLY PRECIPITATION WILL GET ORGANIZED AHEAD OF THIS SYSTEM
AND SPREAD INTO EASTERN KENTUCKY. GENERALLY HAVE SLOWED DOWN THE
PROGRESSION OF HIGHER POPS INTO THE AREA ON WEDNESDAY...BUT MAY NEED
TO BE BACKED OFF A BIT MORE IF THE TRENDS OF A SLOWER PROGRESSION
CONTINUE. IN FACT...THINGS DON`T LOOK ALL THAT DIFFERENT THAN THE
PREVIOUS FEW DAYS WITH RESPECT TO LACK OF FORCING AND NO REAL
MECHANISM FOR GENERATING SHOWERS AND STORMS. THUS...CONFIDENCE IS NOT
HIGH ON PRECIPITATION CHANCES ON WEDNESDAY...SO WILL GENERALLY GO WITH
A GRADIENT IN POPS FROM WEST TO EAST WITH THE HIGHEST IN THE
BLUEGRASS...AND TRAILING OFF INTO SOUTHEAST KENTUCKY. CERTAINLY
POSSIBLE WEDNESDAY ENDS UP BEING DRIER FOR MOST...ESPECIALLY THOSE IN
THE EAST AND SOUTHEAST. SEVERE THREAT WEDNESDAY AFTERNOON IS HIGHLY
CONTINGENT ON ENOUGH INSTABILITY IF CLOUDS CAN HOLD OFF THROUGH THE
DAY. BIGGEST THREAT WILL BE STRONG WINDS AND HAIL IF THE INSTABILITY
PANS OUT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 306 AM EDT TUE MAY 13 2014
THE MODELS ARE ONLY IN FAIR AGREEMENT ALOFT AT THE BEGINNING OF THE
EXTENDED AS THEY ALL DEPICT A DEVELOPING FULL LATITUDE TROUGH WITH
TWIN POLES OF ENERGY DRIVING ITS FORMATION. THE SOUTHERN ENERGY
CLUSTER IS MOVING EAST THROUGH THE SOUTHERN PLAINS AT 00Z THURSDAY
WHILE THE NORTHERN STREAM ONE IS CUTTING INTO THE UPPER MIDWEST. THE
NAM IS SLOWEST...DEEPER...AND FURTHEST SOUTH WITH THE SOUTHERN NODE
AND IS THUS DISCOUNTED AS AN OUTLIER. MEANWHILE...THE ECMWF APPEARS
TO BE A GOOD COMPROMISE BETWEEN THE STRONGER GEM AND WEAKER GFS
HERE. FOR THE NORTHERN PORTION OF THE TROUGH...THE GEM AND GFS ARE
QUITE SIMILAR. THE SOUTHERN WAVE FURTHER AMPLIFIES THAT NIGHT...
PLOWING INTO THE TENNESSEE VALLEY AS IT DRAGS NORTHERN ENERGY SOUTH
TO FORM A DEEP CLOSED LOW OVER THE UPPER MIDWEST BY MIDDAY THURSDAY.
THE GEM REMAINS THE STRONGEST WITH THE BROAD CLOSED LOW TAKING SHAPE
WHILE THE ECMWF HOLDS THE MIDDLE GROUND COMPARED WITH THE WEAKER
GFS. THE CORE OF THE SOUTHERN ENERGY THEN RIDES NORTH INTO THE GREAT
LAKES AS IT IS ABSORBED INTO THE BURGEONING MIDWEST LOW. A WEAKER
REMNANT OF THIS ENERGY DOES EASE THROUGH EAST KENTUCKY THURSDAY
NIGHT JUST AS THE HEIGHT FALLS FROM THE DOMINANT LOW SPREADS OVER
THIS PART OF THE STATE. THIS LARGE LOW THEN SLOWLY PIVOTS NORTHEAST
WITH ITS CORE DEEPENING NORTH OF THE GREAT LAKES IN THE ECMWF BY
FRIDAY NIGHT BUT REMAINING FAIRLY STABLE IN THE OTHERS. EVEN THE
ECMWF STARTS TO FILL THE LOW BY SATURDAY NIGHT AS THE PATTERN
FURTHER DEAMPLIFIES OVER THE OHIO VALLEY...THOUGH SIGNIFICANT MODEL
DIFFERENCES REMAIN WITH THE DEPARTING TROUGH...MAINLY INVOLVING THE
SLOWER EXIT SEEN IN THE GFS AND GEM. CYCLONIC FLOW AND HEIGHTS
SLIGHTLY BELOW NORMAL WILL REMAIN OVER THE AREA INTO MONDAY MORNING
IN ALL THE MODELS...THOUGH THE GFS IS A NOTABLE STANDOUT ON THE MORE
AMPLIFIED SIDE HERE. BY MONDAY AFTERNOON...THOUGH...HEIGHTS SHOULD
BE ON THE RISE AGAIN IN THE FACE OF AN APPROACHING RIDGE FROM THE
PLAINS. WILL FAVOR THE ECMWF SOLUTION THROUGH FRIDAY NIGHT BEFORE A
GENERAL MODEL BLEND IS PREFERRED FOR THE REMAINDER OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE A SFC WAVE DEVELOPING ON A COLD FRONT
JUST OF THE WEST OF THE AREA ON WEDNESDAY. THIS LOW PRESSURE WAVE
WILL LIFT THROUGH EAST KENTUCKY WEDNESDAY NIGHT INTO THURSDAY
MORNING WITH THE BEST CHANCES FOR SOAKING RAINS DURING THE FORECAST.
THUNDERSTORMS WILL BE POSSIBLE ESPECIALLY EARLY WEDNESDAY NIGHT
WHILE SOME DAYTIME INSTABILITY REMAINS. IN FACT...SEVERE WEATHER
CANNOT BE RULED OUT AS CYCLOGENESIS TAKES PLACE THROUGH CENTRAL
KENTUCKY COMPLETE WITH UPPER LEVEL SUPPORT AND DECENT WIND SHEAR
THROUGH EAST KENTUCKY INTO THE EVENING. DO EXPECT ONGOING CONVECTION
AND ITS EVOLUTION INTO THE EVENING TO BE THE PRIMARILY DRIVING
FACTOR IN OUR SEVERE...AND EXCESSIVE RAIN...THREATS THROUGH THURSDAY
MORNING. FOR NOW...WILL CONTINUE TO HIGHLIGHT THESE CONCERNS IN THE
HWO. MUCH COLDER AIR WILL THEN POUR INTO EAST KENTUCKY IN THE WAKE
OF THE SYSTEM MOVING INTO THE MID ATLANTIC STATES. THERE WILL BE
A...MAINLY DIURNALLY DRIVEN...CHANCE FOR SHOWERS INTO THE WEEKEND
BENEATH THE LARGE UPPER LOW. CONVECTION CANNOT BE RULED OUT FOR
SUNDAY AND MONDAY AS A DEVELOPING WARM FRONT WILL ATTEMPT TO MOVE
NORTH INTO EAST KENTUCKY...BUT MORE LIKELY HIGH PRESSURE WILL KEEP
IT SUPPRESSED TO THE SOUTH THROUGH THE REMAINDER OF THE EXTENDED.
THE CR GRID LOAD CAME IN PRETTY GOOD FOR THE BULK OF THE EXTENDED...
THOUGH DID MAKE SOME ADJUSTMENTS TOWARD THE LATEST ECMWF SOLUTION
EARLY ON AND ALSO TO BETTER EMPHASIZE THE DIURNAL NATURE OF THE
SHOWERS FOR THE END OF THE WEEK AND START OF THE WEEKEND. DID ALSO
FINE TUNE SOME LOW TEMP GRIDS LATE IN THE FORECAST TO BETTER CAPTURE
SOME ENHANCED RIDGE AND VALLEY DETAILS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 155 PM EDT TUE MAY 13 2014
PRIMARILY VFR CONDITIONS WILL PERSIST THROUGH THE TAF FORECAST
PERIOD AT THE TAF SITES. SCATTERED TO BROKEN CU WILL GRADUALLY DIMINISH
THROUGH 0Z AND DEVELOP AGAIN AROUND 15Z. SOME OF THIS CONVECTION WILL
MOVE CLOSE TO LOZ...SME AND JKL OVER THE NEXT COUPLE OF HOURS. WITH
THIS IN MIND...HAVE VCTS AT ALL THE TAF SITES THROUGH ABOUT SUNSET.
PATCHY VALLEY FOG WILL FORM AGAIN LATER TONIGHT AND AFFECT VALLEY
LOCATIONS...BUT SHOULD NOT AFFECT THE TAF SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...JP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
446 PM EDT TUE MAY 13 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 353 PM EDT TUE MAY 13 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE W COAST AND ANOTHER
STRETCHING FM QUEBEC THRU THE SE CONUS. THE INTERACTION BTWN A
SHRTWV RIDING NNEWD IN THE STRONG SSW FLOW ALF TO THE E OF THE TROF
AXIS AND RIBBON OF DEEPER MSTR REPRESENTED BY THE 12Z GRB RAOB
RESULTED IN SOME SHRA OVER MAINLY THE ERN CWA INTO EARLY AFTN...BUT
MID LVL DRYING UNDER THE JET SURGE OF PRIMARY SHRTWV LIFTING THRU NW
ONTARIO IS BRINGING DRY WX TO THE ENTIRE CWA LATER THIS AFTN.
HOWEVER...QUITE A BIT OF LOWER CLD IS LINGERING ESPECIALLY OVER THE
WRN CWA WITH ABUNDANT LLVL MSTR BLO SHARPENING SUBSIDENCE INVRNS
SHOWN ON THE 12Z INL/MPX RAOBS BEING ADVECTED TO THE E IN GUSTY SFC
W FLOW TO THE S OF DEPARTING SFC LO IN NW ONTARIO.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON LO CLD TRENDS/
IMPACT ON TEMPS.
TNGT...DESPITE THE ABUNDANT LLVL MSTR...INCRSG ACYC NATURE OF THE
LLVL FLOW WITH CLOSER APRCH OF SFC HI PRES IN THE CENTRAL PLAINS AND
LOSS OF DAYTIME HEATING/MIXING SHOULD PROMOTE CLRG OF THE LO CLD.
WITH LOSS OF DAYTIME HEATING AND WEAKENING PRES GRADIENT...THE GUSTY
W WINDS WL DIMINISH THIS EVNG. UPSTREAM LO TEMPS THIS MRNG AND MOS
FCSTS INDICATE MIN TEMPS WL DIP INTO THE 30S AS H85 TEMPS FALL TO
BTWN 0 AND -2C BY 12Z WED.
WED...SFC HI PRES RDG/LLVL ACYC FLOW WL RESULT IN LIGHTER WINDS/DRY
WX AS PWAT FALLS TO 0.25-0.50 INCH. EXPECT SOME SC TO DVLP AWAY FM
THE STABILIZING/COOLING INFLUENCE OF THE LKS WITH DAYTIME HEATING/
MIXING IN THE PRESENCE OF LINGERING CHILLY H85 TEMPS. THERE WL BE
SOME INCRS IN HI CLDS OVER AT LEAST THE SE PORTION OF THE CWA AS
ANOTHER SHRTWV RIDING NE OUT OF THE BASE OF DEEP TROF IN THE CENTRAL
CONUS MOVES TOWARD THE GREAT LKS. DEEP MIXING TO H75 ON NAM/GFS FCST
SDNGS YIELD MAX TEMPS RISING INTO THE MID/UPR 50S AWAY FM THE
COOLING INFLUENCE OF THE LKS. ALTHOUGH THE DEEP MIXING WL ALLOW
DEWPTS TO MIX OUT INTO THE LO-MID 20S/MIN RH TO FALL TOWARD 25 PCT...
FAIRLY LGT WINDS/MOIST GROUND WL LIMIT ANY FIRE WX CONCERNS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 445 PM EDT TUE MAY 13 2014
COOL TEMPERATURES WILL REMAIN THROUGH THE LONG TERM PERIOD...AS THE
AREAS IS DOMINATED BY LOW PRESSURE AT 500MB. THE 500MB TROUGH
CURRENTLY EXTENDING OVER MUCH OF CENTRAL CANADA AND THE CENTRAL
UNITED STATES WILL SLIDE ACROSS ONTARIO AND MN BY 06Z THURSDAY. LOOK
FOR A LOW TO DEVELOP OVER THE UPPER GREAT LAKES FROM AROUND 00Z
FRIDAY THROUGH AT LEAST FRIDAY...AND THEN SHIFT OFF ACROSS LAKE
HURON AND THE LOWER GREAT LAKES SATURDAY AFTERNOON THROUGH SUNDAY.
ONE OF THE BIG QUESTIONS THIS PERIOD WAS THE POTENTIAL FOR MIXED
PRECIP /RAIN OR SNOW SHOWERS/ FROM THURSDAY EVENING THROUGH SATURDAY
MORNING. AN OVERALL DRIER SOLUTION HAS BEEN COMING IN WITH THE 12Z
MODEL GUIDANCE. BY 12Z THURSDAY UPPER MI WILL BE IN BETWEEN THE
LARGE HIGH PRESSURE OVER S CENTRAL CANADA AND THE N PLAINS...AND THE
SFC LOW SURGING N ACROSS OH AND E MI. THE TRACK OF THE LOW IS
FARTHEST W OFF THE CANADIAN AND ECMWF...WITH ALL SOLUTIONS KEEPING A
WEAK TROUGH OVER CENTRAL AND E UPPER MI THURSDAY-THURSDAY
NIGHT...WITH FAVORABLE COOL N-NW WINDS OFF LAKE SUPERIOR AND 850MB
TEMPS FALLING TO AROUND -6C. THE WETTEST SOLUTION HAS BEEN THE 18Z
NAM CAME IN WITH 0.25IN OF LIQUID OVER E UPPER MI /MAINLY E OF
MUNISING/ FROM 18Z THURSDAY-00Z FRIDAY/. HAVE GONE AHEAD WITH A
DRIER SCENARIO FOR NOW...BUT KEPT THE POTENTIAL FOR SLIGHT CHANCE
RAIN/SNOW SHOWERS. WILL NEED TO WAIT AND SEE ON THIS ONE...AS A LOT
CAN HAPPEN BETWEEN NOW AND THURSDAY AFTERNOON. LOOK FOR THE SFC LOW
TO EXIT INTO SW QUEBEC THURSDAY NIGHT AS HIGH PRESSURE SLOWLY BUILDS
ACROSS THE UPPER GREAT LAKES. LOOK FOR A RETURN TO NEAR NORMAL
TEMPERATURES FOR THE END OF THE WEEKEND AND START OF THE NEXT WORK
WEEK AS HIGH PRESSURE REMAINS OVERHEAD...AND THE 500MB RIDGE BUILDS
IN FROM THE GULF OF MEXICO UP THROUGH THE UPPER GREAT LAKES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 124 PM EDT TUE MAY 13 2014
WITH ABUNDANT LLVL MSTR SHOWN ON THE 12Z INL/MPX RAOBS...SLOWED
TREND TO VFR A BIT. BUT DAYTIME HEATING/MIXING THAT MAINTAINS GUSTY
W WINDS SHOULD ALLOW IMPROVEMENT TO VFR AT ALL 3 SITES THIS AFTN...
SLOWEST AT THE MORE EXPOSED CMX LOCATION WITH STRONGER...MOST
PRONOUNCED UPSLOPE WIND COMPONENT. THEN VFR CONDITIONS AND LIGHTER
WINDS WL PREVAIL INTO WED WITH DRY HI PRES/WEAKER PRES GRADIENT
DOMINATING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT TUE MAY 13 2014
EXPECT W WINDS UP TO 30 KKTS ON THE SOUTHERN FLANK OF LO PRES MOVING
NEWD THRU ONTARIO...STRONGEST OVER THE NCENTRAL WHERE THE TERRAIN
FUNNELS THIS FLOW BETWEEN THE KEWEENAW AND ISLE ROYALE...TO DIMINISH
TO UNDER 20-25 KTS TONIGHT WITH THE ARRIVAL OF A WEAKER PRES
GRADIENT CLOSER TO APPROACHING HI PRES. WINDS WILL THEN REMAIN UNDER
25 KTS THRU THE REST OF THE FORECAST PERIOD WITH A RELATIVELY WEAK
PRES GRADIENT DOMINATING. THERE DOES REMAIN SOME POTENTIAL THAT N
WINDS ON THU INTO FRI MAY REACH 25-30 KTS OVER MAINLY THE E HALF OF
LAKE SUPERIOR IF A LO PRES SYSTEM LIFTING ACROSS THE GREAT LAKES
TRACKS FARTHER TO THE W. THIS SCENARIO DOES NOT APPEAR LIKELY AT
THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 328 PM EDT TUE MAY 13 2014
THE NEXT CHANCE OF PRECIPITATION LOOKS TO FALL THURSDAY THROUGH
FRIDAY. HOWEVER THE BEST CHANCE OF 0.10IN OR MORE WILL BE OVER THE E
THIRD OF UPPER MI. SOME VERY LIGHT SNOW MAY EVEN BE POSSIBLE OVER THE
W HALF THURSDAY NIGHT INTO FRIDAY.
THE MAIN CONCERNS RIVER WISE WILL CONTINUE TO BE OVER THE W HALF OF
UPPER MI. THEY INCLUDE THE STURGEON RIVER AT CHASSELL...WHICH IS
SLOWLY FALLING...AND THE MICHIGAMME AT REPUBLIC...WITCH LAKE...AND
CRYSTAL FALLS...WHICH LOOK TO HAVE ALL CRESTED AS WELL AND ARE SLOWLY
ON THEIR WAY DOWN. RIVER FLOWS WILL LIKELY REMAIN HIGH THROUGH THE
REST OF THE WEEK. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS
SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
354 PM EDT TUE MAY 13 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 353 PM EDT TUE MAY 13 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE W COAST AND ANOTHER
STRETCHING FM QUEBEC THRU THE SE CONUS. THE INTERACTION BTWN A
SHRTWV RIDING NNEWD IN THE STRONG SSW FLOW ALF TO THE E OF THE TROF
AXIS AND RIBBON OF DEEPER MSTR REPRESENTED BY THE 12Z GRB RAOB
RESULTED IN SOME SHRA OVER MAINLY THE ERN CWA INTO EARLY AFTN...BUT
MID LVL DRYING UNDER THE JET SURGE OF PRIMARY SHRTWV LIFTING THRU NW
ONTARIO IS BRINGING DRY WX TO THE ENTIRE CWA LATER THIS AFTN.
HOWEVER...QUITE A BIT OF LOWER CLD IS LINGERING ESPECIALLY OVER THE
WRN CWA WITH ABUNDANT LLVL MSTR BLO SHARPENING SUBSIDENCE INVRNS
SHOWN ON THE 12Z INL/MPX RAOBS BEING ADVECTED TO THE E IN GUSTY SFC
W FLOW TO THE S OF DEPARTING SFC LO IN NW ONTARIO.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON LO CLD TRENDS/
IMPACT ON TEMPS.
TNGT...DESPITE THE ABUNDANT LLVL MSTR...INCRSG ACYC NATURE OF THE
LLVL FLOW WITH CLOSER APRCH OF SFC HI PRES IN THE CENTRAL PLAINS AND
LOSS OF DAYTIME HEATING/MIXING SHOULD PROMOTE CLRG OF THE LO CLD.
WITH LOSS OF DAYTIME HEATING AND WEAKENING PRES GRADIENT...THE GUSTY
W WINDS WL DIMINISH THIS EVNG. UPSTREAM LO TEMPS THIS MRNG AND MOS
FCSTS INDICATE MIN TEMPS WL DIP INTO THE 30S AS H85 TEMPS FALL TO
BTWN 0 AND -2C BY 12Z WED.
WED...SFC HI PRES RDG/LLVL ACYC FLOW WL RESULT IN LIGHTER WINDS/DRY
WX AS PWAT FALLS TO 0.25-0.50 INCH. EXPECT SOME SC TO DVLP AWAY FM
THE STABILIZING/COOLING INFLUENCE OF THE LKS WITH DAYTIME HEATING/
MIXING IN THE PRESENCE OF LINGERING CHILLY H85 TEMPS. THERE WL BE
SOME INCRS IN HI CLDS OVER AT LEAST THE SE PORTION OF THE CWA AS
ANOTHER SHRTWV RIDING NE OUT OF THE BASE OF DEEP TROF IN THE CENTRAL
CONUS MOVES TOWARD THE GREAT LKS. DEEP MIXING TO H75 ON NAM/GFS FCST
SDNGS YIELD MAX TEMPS RISING INTO THE MID/UPR 50S AWAY FM THE
COOLING INFLUENCE OF THE LKS. ALTHOUGH THE DEEP MIXING WL ALLOW
DEWPTS TO MIX OUT INTO THE LO-MID 20S/MIN RH TO FALL TOWARD 25 PCT...
FAIRLY LGT WINDS/MOIST GROUND WL LIMIT ANY FIRE WX CONCERNS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 450 AM EDT TUE MAY 13 2014
DEEP TROUGHING IN PLACE ON WEDNESDAY AND THIS MAY ONLY DEEPEN FURTHER
BY LATE THIS WEEK AS AN UPPER LOW SLIDES ACROSS THE GREAT LAKES.
UPPER LOW WILL ONLY SLOWLY EXIT THE UPPER GREAT LAKES THIS WEEKEND.
NOT A LOT OF PRECIPITATION WITH THE EXPECTED PATTERN /THOUGH FRIDAY
IS STILL UNCERTAIN/...BUT IT WILL REMAIN UNSETTLED AND COOL INTO AT
LEAST FIRST PART OF WEEKEND. AND STILL CANNOT COUNT OUT POTENTIAL
FOR ACCUMULATING SNOW AROUND FRIDAY THOUGH THE MODEL LEADING THE
CHARGE ON THAT IDEA THE LAST SEVERAL DAYS...THE ECMWF...HAS BACKED
AWAY FROM THAT IDEA WITH MOST RECENT MODEL RUN...AS HAS THE GEM-NH
AND THE UKMET WHICH WAS TRACKING ALONG WITH THE ECMWF FOR A WHILE
NOW. ONLY TIME WILL TELL IF THIS IS A TREND OR A TEMPORARY SHIFT.
WEDNESDAY STILL APPEARS GENERALLY QUIET. SFC LOW WILL BE OVER
NORTHERN ONTARIO WITH GRADIENT WESTERLY FLOW OVER LK SUPERIOR/UPR
MICHIGAN. GRADIENT WEAKENS ENOUGH IN THE AFTN TO RESULT IN LAKE
BREEZES. FORCING WEAKER THAN IT LOOKED 24 HR AGO AND MOISTURE RATHER
PALTRY. EVEN THOUGH THERE MAY BE BUILD UP OF HIGHER BASED CU...NOT
EXPECTING ANY SHRA IN LAKE BREEZE CONVERGENCE AREAS OF CNTRL UPR
MICHIGAN. DWPTS START DAY AROUND 30F AND MIXED LAYER DWPNT OUTPUT
POINTED TO AROUND 20 FOR INTERIOR WEST BY MID AFTN. PRETTY FEASIBLE
GIVEN THE DEPTH OF MIXING. FOR NOW DROPPED DWPNTS INTO LOW-MID 20S
WHICH RESULTS IN RH VALUES AROUND 30 PCT. FIRE WX ISSUES WILL BE
MITIGATED BY RECENT RAINFALL AND SINCE WINDS SHOULD REMAIN MAINLY
BELOW 15 MPH.
WEDNESDAY NIGHT FEATURES CONTINUED QUIET WEATHER PATTERN WITH INCREASING
NORTH GRADIENT FLOW AS HIGH PRESSURE BUILDS OVER MANITOBA/ONTARIO AND
LOW PRESSURE WAVE DEEPENS OVER OHIO VALLEY AND BEGINS TO LIFT NORTH
TO THE CENTRAL GREAT LAKES REGION. MID-HIGH CLOUDS INCREASE WHICH
WILL KEEP MIN TEMPS ABOVE FREEZING MAJORITY OF CWA.
THURSDAY INTO FRIDAY...SHORTWAVE ROUNDS BASE OF PRIMARY TROUGH ALOFT
WHILE SECONDARY JET STREAK DIGS ACROSS THE ROCKIES INTO THE WESTERN
SIDE OF THE UPPER LEVEL TROUGH. RESULT IS TROUGH ALOFT BECOMING
NEGATIVE TILTED THEN CLOSING OFF BY FRIDAY. STRONGEST SHORTWAVE
WITHIN THE TROUGH LIFTS NORTHWARD. IT IS THIS SHORTWAVE AND
ASSOCIATED SFC LOW THAT HOLDS THE KEY FOR THE THURSDAY NIGHT AND
FRIDAY FORECAST. RECENT RUNS OF THE ECMWF WERE THE MOST WRAPPED UP
AND FARTHER WEST WITH THIS WAVE AND ASSOCIATED SFC LOW. GFS MOSTLY
HAS STAYED PROGRESSIVE AND FARTHER EAST WITH THE LOW...LIFTING IT
NORTHWARD OVER THE LOWER LAKES INSTEAD OF THE CENTRAL GREAT LAKES.
LATEST ECMWF/UKMET/GEM-NH GOING THAT WAY TOO. SEEMS THAT ECMWF HAS
MORE SHORTWAVE ENERGY AHEAD OF THE TROUGH THAN WAS THERE PERVIOUSLY.
THIS RESULTS IN UPPER TROUGH STAYING MORE OPEN/POSITIVELY TILTED
WHICH KEEPS THAT MAIN SHORTWAVE JUST A BIT FARTHER EAST. AT THE SAME
TIME...ECMWF ENSEMBLE MEAN AND A FAIR AMOUNT OF ENSEMBLES FROM THE
GEM STILL CONTINUE TO SUPPORT POTENTIAL FOR FARTHER WEST SFC LOW...
SO THAT IDEA MAY NOT BE DONE JUST YET.
PRIMARY CHANGE TO THE GOING FORECAST WAS TO GO BACK TO RAIN/SNOW
SHOWERS IDEA INSTEAD OF WIDESPREAD RAIN/SNOW...BOOSTED BY DAYTIME
HEATING DUE TO INSTABILITY ALOFT WITH THE UPPER TROUGH. STILL KEPT
TEMPS CHILLY ON FRIDAY AS THERE SHOULD BE BKN-OVC SKIES WITH NORTH OR
NORTHEAST WINDS OFF LK SUPERIOR...EVEN WITHOUT A STRONGER SYSTEM.
INITIAL PLAN WAS TO PUT A MENTION OF ACCUMULATING SNOW IN THE MORNING
HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS...BUT SINCE THE MODEL
THAT WAS SHOWING THIS MOST PERSISTENTLY BACKED AWAY...WILL NOT PUT
THAT MENTION IN THERE AFTER ALL. PROBABLY NOT TOO MUCH OF A STRETCH
TO SAY THAT WILL BE FINE WITH MOST PEOPLE THAT ARE TRYING TO PUT THIS
LONG COLD WINTER...AND EARLY SPRING...BEHIND THEM.
TROUGHING GRADUALLY PULLS AWAY DURING THE WEEKEND...BUT COULD STILL
SEE POTENTIAL FOR SOME LINGERING RAIN/SNOW SHOWERS ON SATURDAY WITH
FAIR AMOUNTS OF CLOUDS. LOOKS LIKE WE WILL BE IN THE CLEAR FOR
SUNDAY AND PROBABLY MONDAY AS WELL...WITH THE RETURN OF WARMER
TEMPERATURES...ALBEIT STILL BELOW NORMAL. READINGS MAY REACH MID TO
UPR 60S INLAND WEST WHILE MOST OTHER AREAS ARE IN THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 124 PM EDT TUE MAY 13 2014
WITH ABUNDANT LLVL MSTR SHOWN ON THE 12Z INL/MPX RAOBS...SLOWED
TREND TO VFR A BIT. BUT DAYTIME HEATING/MIXING THAT MAINTAINS GUSTY
W WINDS SHOULD ALLOW IMPROVEMENT TO VFR AT ALL 3 SITES THIS AFTN...
SLOWEST AT THE MORE EXPOSED CMX LOCATION WITH STRONGER...MOST
PRONOUNCED UPSLOPE WIND COMPONENT. THEN VFR CONDITIONS AND LIGHTER
WINDS WL PREVAIL INTO WED WITH DRY HI PRES/WEAKER PRES GRADIENT
DOMINATING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT TUE MAY 13 2014
EXPECT W WINDS UP TO 30 KKTS ON THE SOUTHERN FLANK OF LO PRES MOVING
NEWD THRU ONTARIO...STRONGEST OVER THE NCENTRAL WHERE THE TERRAIN
FUNNELS THIS FLOW BETWEEN THE KEWEENAW AND ISLE ROYALE...TO DIMINISH
TO UNDER 20-25 KTS TONIGHT WITH THE ARRIVAL OF A WEAKER PRES
GRADIENT CLOSER TO APPROACHING HI PRES. WINDS WILL THEN REMAIN UNDER
25 KTS THRU THE REST OF THE FORECAST PERIOD WITH A RELATIVELY WEAK
PRES GRADIENT DOMINATING. THERE DOES REMAIN SOME POTENTIAL THAT N
WINDS ON THU INTO FRI MAY REACH 25-30 KTS OVER MAINLY THE E HALF OF
LAKE SUPERIOR IF A LO PRES SYSTEM LIFTING ACROSS THE GREAT LAKES
TRACKS FARTHER TO THE W. THIS SCENARIO DOES NOT APPEAR LIKELY AT
THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 328 PM EDT TUE MAY 13 2014
THE NEXT CHANCE OF PRECIPITATION LOOKS TO FALL THURSDAY THROUGH
FRIDAY. HOWEVER THE BEST CHANCE OF 0.10IN OR MORE WILL BE OVER THE E
THIRD OF UPPER MI. SOME VERY LIGHT SNOW MAY EVEN BE POSSIBLE OVER THE
W HALF THURSDAY NIGHT INTO FRIDAY.
THE MAIN CONCERNS RIVER WISE WILL CONTINUE TO BE OVER THE W HALF OF
UPPER MI. THEY INCLUDE THE STURGEON RIVER AT CHASSELL...WHICH IS
SLOWLY FALLING...AND THE MICHIGAMME AT REPUBLIC...WITCH LAKE...AND
CRYSTAL FALLS...WHICH LOOK TO HAVE ALL CRESTED AS WELL AND ARE SLOWLY
ON THEIR WAY DOWN. RIVER FLOWS WILL LIKELY REMAIN HIGH THROUGH THE
REST OF THE WEEK. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS
SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
328 PM EDT TUE MAY 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT TUE MAY 13 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED AN AMPLIFIED TROF
OVER THE CNTRL CONUS. WITHIN THE TROF...ONE SHORTWAVE WAS LIFTING
THRU NRN MN INTO NRN ONTARIO. ANOTHER SHORTWAVE WAS LINGERING IN THE
BASE OF THE TROF OVER NM/CO. THIS SHORTWAVE MAY BRING SOME
INTERESTING WEATHER LATER THIS WEEK DEPENDING ON HOW IT INTERACTS
WITH OTHER NRN STREAM ENERGY DIVING INTO THE TROF. WITH THE
SHORTWAVE LIFTING INTO NRN ONTARIO...SFC LOW PRES WAS TRACKING N
ACROSS WRN LAKE SUPERIOR. OCCLUDED FRONT WAS SWEEPING INTO WRN UPPER
MI WHILE SFC WARM FRONT IS STILL HELD UP S OF UPPER MI.
FORTUNATELY...LITTLE PCPN HAS FALLEN SINCE SHRA MOVED THRU THE FCST
AREA YESTERDAY MORNING/EARLY AFTN. THIS WILL HELP EASE RISES ON
RIVERS THAT HAVE HIGH FLOWS.
AS OCCLUDED FRONT MARCHES ACROSS THE AREA THIS MORNING/EARLY AFTN...
WILL MAINTAIN A SHRA CHC ALONG/AHEAD OF IT. THERE MAY YET BE SOME
THUNDER OVER THE ERN FCST AREA...BUT POTENTIAL LOOKS LIMITED WITH
LITTLE INSTABILITY. MEANWHILE...FOG...LOCALLY DENSE...WILL LIFT
QUICKLY WITH FROPA. OTHER ITEM OF NOTE TODAY IS THAT HEALTHY CAA
WILL AID GUSTY WINDS...ESPECIALLY ACROSS THE KEWEENAW UNDER
FAVORABLE WESTERLY WIND DIRECTION. GUSTS SHOULD BE UP TO AROUND 40KT
AT TIMES THERE.
DRY WEATHER WILL FOLLOW FOR TONIGHT UNDER DRY AIR MASS. LOWS WILL
FALL INTO THE 30S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 450 AM EDT TUE MAY 13 2014
DEEP TROUGHING IN PLACE ON WEDNESDAY AND THIS MAY ONLY DEEPEN FURTHER
BY LATE THIS WEEK AS AN UPPER LOW SLIDES ACROSS THE GREAT LAKES.
UPPER LOW WILL ONLY SLOWLY EXIT THE UPPER GREAT LAKES THIS WEEKEND.
NOT A LOT OF PRECIPITATION WITH THE EXPECTED PATTERN /THOUGH FRIDAY
IS STILL UNCERTAIN/...BUT IT WILL REMAIN UNSETTLED AND COOL INTO AT
LEAST FIRST PART OF WEEKEND. AND STILL CANNOT COUNT OUT POTENTIAL
FOR ACCUMULATING SNOW AROUND FRIDAY THOUGH THE MODEL LEADING THE
CHARGE ON THAT IDEA THE LAST SEVERAL DAYS...THE ECMWF...HAS BACKED
AWAY FROM THAT IDEA WITH MOST RECENT MODEL RUN...AS HAS THE GEM-NH
AND THE UKMET WHICH WAS TRACKING ALONG WITH THE ECMWF FOR A WHILE
NOW. ONLY TIME WILL TELL IF THIS IS A TREND OR A TEMPORARY SHIFT.
WEDNESDAY STILL APPEARS GENERALLY QUIET. SFC LOW WILL BE OVER
NORTHERN ONTARIO WITH GRADIENT WESTERLY FLOW OVER LK SUPERIOR/UPR
MICHIGAN. GRADIENT WEAKENS ENOUGH IN THE AFTN TO RESULT IN LAKE
BREEZES. FORCING WEAKER THAN IT LOOKED 24 HR AGO AND MOISTURE RATHER
PALTRY. EVEN THOUGH THERE MAY BE BUILD UP OF HIGHER BASED CU...NOT
EXPECTING ANY SHRA IN LAKE BREEZE CONVERGENCE AREAS OF CNTRL UPR
MICHIGAN. DWPTS START DAY AROUND 30F AND MIXED LAYER DWPNT OUTPUT
POINTED TO AROUND 20 FOR INTERIOR WEST BY MID AFTN. PRETTY FEASIBLE
GIVEN THE DEPTH OF MIXING. FOR NOW DROPPED DWPNTS INTO LOW-MID 20S
WHICH RESULTS IN RH VALUES AROUND 30 PCT. FIRE WX ISSUES WILL BE
MITIGATED BY RECENT RAINFALL AND SINCE WINDS SHOULD REMAIN MAINLY
BELOW 15 MPH.
WEDNESDAY NIGHT FEATURES CONTINUED QUIET WEATHER PATTERN WITH INCREASING
NORTH GRADIENT FLOW AS HIGH PRESSURE BUILDS OVER MANITOBA/ONTARIO AND
LOW PRESSURE WAVE DEEPENS OVER OHIO VALLEY AND BEGINS TO LIFT NORTH
TO THE CENTRAL GREAT LAKES REGION. MID-HIGH CLOUDS INCREASE WHICH
WILL KEEP MIN TEMPS ABOVE FREEZING MAJORITY OF CWA.
THURSDAY INTO FRIDAY...SHORTWAVE ROUNDS BASE OF PRIMARY TROUGH ALOFT
WHILE SECONDARY JET STREAK DIGS ACROSS THE ROCKIES INTO THE WESTERN
SIDE OF THE UPPER LEVEL TROUGH. RESULT IS TROUGH ALOFT BECOMING
NEGATIVE TILTED THEN CLOSING OFF BY FRIDAY. STRONGEST SHORTWAVE
WITHIN THE TROUGH LIFTS NORTHWARD. IT IS THIS SHORTWAVE AND
ASSOCIATED SFC LOW THAT HOLDS THE KEY FOR THE THURSDAY NIGHT AND
FRIDAY FORECAST. RECENT RUNS OF THE ECMWF WERE THE MOST WRAPPED UP
AND FARTHER WEST WITH THIS WAVE AND ASSOCIATED SFC LOW. GFS MOSTLY
HAS STAYED PROGRESSIVE AND FARTHER EAST WITH THE LOW...LIFTING IT
NORTHWARD OVER THE LOWER LAKES INSTEAD OF THE CENTRAL GREAT LAKES.
LATEST ECMWF/UKMET/GEM-NH GOING THAT WAY TOO. SEEMS THAT ECMWF HAS
MORE SHORTWAVE ENERGY AHEAD OF THE TROUGH THAN WAS THERE PERVIOUSLY.
THIS RESULTS IN UPPER TROUGH STAYING MORE OPEN/POSITIVELY TILTED
WHICH KEEPS THAT MAIN SHORTWAVE JUST A BIT FARTHER EAST. AT THE SAME
TIME...ECMWF ENSEMBLE MEAN AND A FAIR AMOUNT OF ENSEMBLES FROM THE
GEM STILL CONTINUE TO SUPPORT POTENTIAL FOR FARTHER WEST SFC LOW...
SO THAT IDEA MAY NOT BE DONE JUST YET.
PRIMARY CHANGE TO THE GOING FORECAST WAS TO GO BACK TO RAIN/SNOW
SHOWERS IDEA INSTEAD OF WIDESPREAD RAIN/SNOW...BOOSTED BY DAYTIME
HEATING DUE TO INSTABILITY ALOFT WITH THE UPPER TROUGH. STILL KEPT
TEMPS CHILLY ON FRIDAY AS THERE SHOULD BE BKN-OVC SKIES WITH NORTH OR
NORTHEAST WINDS OFF LK SUPERIOR...EVEN WITHOUT A STRONGER SYSTEM.
INITIAL PLAN WAS TO PUT A MENTION OF ACCUMULATING SNOW IN THE MORNING
HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS...BUT SINCE THE MODEL
THAT WAS SHOWING THIS MOST PERSISTENTLY BACKED AWAY...WILL NOT PUT
THAT MENTION IN THERE AFTER ALL. PROBABLY NOT TOO MUCH OF A STRETCH
TO SAY THAT WILL BE FINE WITH MOST PEOPLE THAT ARE TRYING TO PUT THIS
LONG COLD WINTER...AND EARLY SPRING...BEHIND THEM.
TROUGHING GRADUALLY PULLS AWAY DURING THE WEEKEND...BUT COULD STILL
SEE POTENTIAL FOR SOME LINGERING RAIN/SNOW SHOWERS ON SATURDAY WITH
FAIR AMOUNTS OF CLOUDS. LOOKS LIKE WE WILL BE IN THE CLEAR FOR
SUNDAY AND PROBABLY MONDAY AS WELL...WITH THE RETURN OF WARMER
TEMPERATURES...ALBEIT STILL BELOW NORMAL. READINGS MAY REACH MID TO
UPR 60S INLAND WEST WHILE MOST OTHER AREAS ARE IN THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 124 PM EDT TUE MAY 13 2014
WITH ABUNDANT LLVL MSTR SHOWN ON THE 12Z INL/MPX RAOBS...SLOWED
TREND TO VFR A BIT. BUT DAYTIME HEATING/MIXING THAT MAINTAINS GUSTY
W WINDS SHOULD ALLOW IMPROVEMENT TO VFR AT ALL 3 SITES THIS AFTN...
SLOWEST AT THE MORE EXPOSED CMX LOCATION WITH STRONGER...MOST
PRONOUNCED UPSLOPE WIND COMPONENT. THEN VFR CONDITIONS AND LIGHTER
WINDS WL PREVAIL INTO WED WITH DRY HI PRES/WEAKER PRES GRADIENT
DOMINATING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT TUE MAY 13 2014
LOW PRESSURE OVER WESTERN LK SUPERIOR WILL MOVE NORTHWARD TOWARD
HUDSON BAY TONIGHT INTO WEDNESDAY. A COLD FRONT CROSSES THE REGION
THIS MORNING SHIFTING WINDS FROM EASTERLY TO WESTERLY. WEST WINDS BY
AFTERNOON COULD REACH 30 KTS OVER PORTIONS WESTERN AND NORTH CENTRAL
LAKE SUPERIOR. THESE GUSTY WINDS WILL DIMINISH BELOW 25 KTS LATE
TONIGHT INTO WEDNESDAY MORNING. WINDS FOR THE REST OF THE WEEK WILL
MAINLY BE BLO 20 KTS. THERE DOES REMAIN SOME POTENTIAL THAT
NORTHERLY WINDS ON FRIDAY MAY REACH 30 KTS DEPENDING ON THE TRACK
AND STRENGTH OF A LOW PRESSURE SYSTEM LIFTING ACROSS THE GREAT LAKES.
&&
.HYDROLOGY...
ISSUED AT 328 PM EDT TUE MAY 13 2014
THE NEXT CHANCE OF PRECIPITATION LOOKS TO FALL THURSDAY THROUGH
FRIDAY. HOWEVER THE BEST CHANCE OF 0.10IN OR MORE WILL BE OVER THE E
THIRD OF UPPER MI. SOME VERY LIGHT SNOW MAY EVEN BE POSSIBLE OVER THE
W HALF THURSDAY NIGHT INTO FRIDAY.
THE MAIN CONCERNS RIVER WISE WILL CONTINUE TO BE OVER THE W HALF OF
UPPER MI. THEY INCLUDE THE STURGEON RIVER AT CHASSELL...WHICH IS
SLOWLY FALLING...AND THE MICHIGAMME AT REPUBLIC...WITCH LAKE...AND
CRYSTAL FALLS...WHICH LOOK TO HAVE ALL CRESTED AS WELL AND ARE SLOWLY
ON THEIR WAY DOWN. RIVER FLOWS WILL LIKELY REMAIN HIGH THROUGH THE
REST OF THE WEEK. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS
SHOULD CONTINUE TO MONITOR THE LATEST RIVER LEVELS. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...KC
MARINE...JLA
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
148 PM EDT TUE MAY 13 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 308 AM EDT TUE MAY 13 2014
A COLD FRONT WILL PUSH EASTWARD THROUGH MICHIGAN TODAY TRIGGERING
SHOWERS AND THUNDERSTORMS. AN AREA OF HIGH PRESSURE WILL MOVE IN
FOR TUESDAY INTO EARLY WEDNESDAY DIMINISHING MOST OF THE
PRECIPITATION. A WAVE OF LOW PRESSURE WILL ARRIVE FOR WEDNESDAY
NIGHT WITH WET WEATHER EXPECTED.
&&
.UPDATE...
ISSUED AT 1105 AM EDT TUE MAY 13 2014
SHORT WINDOW OF OPPORTUNITY FOR STRONGER STORMS TO DEVELOP EXISTS
FROM LATE THIS MORNING THROUGH MID AFTERNOON PRIMARY EAST OF I-69
INCLUDING JXN.
THE FIRST SIGN OF NEW/DIURNAL CONVECTIVE DEVELOPMENT IS STARTING
TO SHOW UP AS A NARROW LINE OF SHOWERS OVER INDIANA AROUND KLAF.
THIS ACTIVITY SHOULD INCREASE IN INTENSITY AS IT HEADS NE TOWARD
JXN INTO AN AREA OF SUNSHINE WITH SB CAPES ALREADY AROUND 1500
J/KG. THE LINE WILL NEED TO BE MONITORED OVER THE NEXT FEW HOURS
FOR POSSIBLE SVR WX.
OTHERWISE MOSTLY CLOUDY SKIES OVER THE REST OF THE CWFA TODAY WITH
SCATTERED SHOWERS AND ISOLATED STORMS AS THE COLD FRONT PRESSES
EAST THROUGH THE AREA. THE FRONT WAS CROSSING LK MI AT MID MORNING
AND THE LATEST RUC GUIDANCE HAS IT CLEARING THE CWFA BY 20Z WITH
WESTERLY LOW LEVEL FLOW DEVELOPING AND GRADUALLY LOWERING SFC DEW
PTS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 308 AM EDT TUE MAY 13 2014
THE MAIN CHALLENGE IN THE SHORT TERM DEALS WITH THE RISK FOR
SEVERE WEATHER TODAY ALONG WITH THE POTENTIAL FOR RAIN WEDNESDAY
NIGHT.
LOOKS LIKE THE COMBINATION OF STRONGER DEEP LAYER SHEAR AND
INSTABILITY WILL OFFER A RISK FOR SOME SEVERE WEATHER INTO THIS
AFTERNOON. THE MOST UNSTABLE AIRMASS IS SHOWN TO DEVELOP EARLY TO
MID AFTERNOON AROUND JACKSON TO LANSING BEFORE THE COLD FRONT
PUSHES THROUGH. THUS THOSE LOCATIONS STAND THE GREATEST POTENTIAL.
THE MORNING CONVECTION COULD ALSO BE STRONG...GIVEN MU CAPES OVER
1500 J/KG...BUT THE SHEAR IS CURRENTLY WEAK. THE MAIN RISKS FOR
SEVERE WEATHER WOULD BE HAIL AND DAMAGING WINDS WITH TORNADOES A
LESS RISK. WILL CERTAINLY NEED TO MONITOR TRENDS CLOSELY.
INCREASED POPS FOR WED NIGHT. DECENT LOOKING WAVE OF LOW PRESSURE
LIFTS UP FROM THE LOWER MS VALLEY. COUPLED UPPER JET WILL HAVE
GULF MOISTURE TO WORK WITH PROVIDING WIDESPREAD RAIN. I INCREASED
POPS CONSIDERABLY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 308 AM EDT TUE MAY 13 2014
UPPER TROUGH REMAINS OVER THE GREAT LAKES REGION INTO FRIDAY.
THIS WILL ALLOW FOR A FEW SHOWERS...BUT WIDESPREAD HEAVY RAIN IS
NOT FORECASTED AT THIS TIME. THE RISK FOR SHOWERS WILL DECREASE
INTO SUNDAY AS UPPER LEVEL RIDGING TRIES TO BUILD IN. OVERALL IT
LOOKS LIKE WITH A LOW LEVEL THERMAL TROUGH IN PLACE INTO THE
WEEKEND...WE WILL END UP WITH COOLER THAN NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 148 PM EDT TUE MAY 13 2014
A COLD FRONT WAS MOVING THROUGH THE REGION THIS AFTERNOON AND WAS
NEAR A AMN-AZO LINE AS OF 17Z. TO THE EAST OF THE FRONT THERE WILL
STILL BE THE RISK FOR A FEW THUNDERSTORMS. THE FRONT AND THE
STORMS ARE EXPECTED TO BE EAST OF LAN AND JXN BY 22-23Z.
MOSTLY MVFR CAN BE EXPECTED EITHER SIDE OF THE FRONT...HOWEVER
SOME PATCHY IFR SHOULD BE SEEN ACROSS THE I-94 TAF SITES BEHIND
THE FRONT WHICH SHOULD LIFT BY 06Z.
VFR CONDITIONS ARE EXPECTED TO FILTER INTO THE REGION TONIGHT...
ALONG THE I-96 TAF SITES AROUND 04-06Z...AND TO THE I-94 SITES
08-10Z.
&&
.MARINE...
ISSUED AT 1105 AM EDT TUE MAY 13 2014
MARINE WEB CAMS THIS MORNING REVEAL DENSE FOG AT HOLLAND... GRAND
HAVEN AND MKG. NOT QUITE SURE HOW EXTENSIVE THE DENSE FOG IS SINCE
HIGHER CLOUDS ARE MASKING THE STRATUS ON VSBL SATELLITE. CONSIDERED
A MARINE FOG ADVISORY BUT WILL HOLD OFF AND JUST CARRY AREAS OF
DENSE FOG THROUGH THE AFTERNOON. THE SFC FRONT WILL BE MOVING
THROUGH SOON LEADING TO LOWERING SFC DEW PTS WHICH SHOULD HELP
IMPROVE VISIBILITIES AT THE LAKESHORE AS THE DAY WEARS ON.
&&
.HYDROLOGY...
ISSUED AT 308 AM EDT TUE MAY 13 2014
HEAVY RAIN IS A RISK TODAY AND WEDNESDAY NIGHT. PWAT VALUES WILL
TOP 1.5 INCHES TODAY AND POSSIBLY WED NIGHT. LCLS WILL BE LOW
TODAY...AND COULD ALLOW FOR EFFICIENT RAINFALL. LOCAL AMOUNTS OVER
AN INCH ARE LIKELY TODAY. AS FOR WIDESPREAD VALUES OVER 2
INCHES...A SMALL RISK EXISTS...BUT CURRENTLY THAT RISK LOOKS LOWS.
AM THINKING MOST LOCATIONS WILL SEE OVER A HALF INCH OF RAIN WED
NIGHT GIVEN THE PASSAGE OF THE LOW PRESSURE SYSTEM THAT WILL
CONTAIN GULF MOISTURE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...MJS
AVIATION...JK
HYDROLOGY...MJS
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
140 PM EDT TUE MAY 13 2014
.AVIATION...
//DISCUSSION...
EXISTING UNSTABLE PRE-FRONTAL ENVIRONMENT WILL SUPPORT SHOWER AND
THUNDERSTORM DEVELOPMENT THROUGH THE EVENING HOURS. LATEST RADAR
TRENDS CONTINUE TO INDICATE AN INITIAL PERIOD OF CONVECTION
IMPACTING MBS AND FNT AT THE START OF THE PERIOD...WITH ADDITIONAL
DEVELOPMENT EXPANDING INTO PTK/DTW 20-21Z. CLUSTERS OF SHOWERS AND
THUNDERSTORMS WILL LIKELY IMPACT THE SOUTHERN TERMINALS WELL INTO
THE EVENING. PERSISTENT MID LEVEL FRONTAL FORCING AND MOIST
CONDITIONS WILL THEN SUPPORT AN EXPANDING STRATUS DECK WITH
ADDITIONAL SHOWERS TONIGHT. POTENTIAL DOES EXIST FOR PERIOD OF IFR
DURING THIS TIME.
FOR DTW...CURRENT TRENDS UPSTREAM CONTINUE TO INDICATE THE GREATEST
POTENTIAL FOR THUNDERSTORMS WILL CENTER BETWEEN 21Z AND 00Z. WIND
SHIFT WITH THE COLD FRONT AROUND 02Z.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FT THIS AFTERNOON. HIGH
CONFIDENCE THIS EVENING AND TONIGHT.
* MEDIUM CONFIDENCE IN THUNDERSTORMS IMPACTING THE AIRPORT THIS
EVENING.
&&
.PREV DISCUSSION...ISSUED 1053 AM EDT TUE MAY 13 2014
UPDATE...
RECENT PRESENTATION OF WATER VAPOR/VISIBLE IMAGERY AND TRENDS IN
OBSERVATIONS LEAVE EXPECTATIONS LARGELY UNCHANGED FOR A WINDOW FROM
MID AFTERNOON INTO THE EVENING FOR THE POSSIBILITY OF STRONGER
CONVECTIVE DEVELOPMENT. IN FACT...SOME LONGER RESIDENCE TIME OF
NEARLY FULL INSOLATION SOUTHEAST OF AN OWOSSO TO BAD AXE LINE
NETTING A PROGRESSIVE SURFACE TEMPERATURE RESPONSE. UPDATE ALREADY
OUT TO ADDRESS THIS WITH READINGS NOW EXPECTED TO LAND SOLIDLY IN
THE LOWER AND MIDDLE 80S THROUGHOUT THIS CORRIDOR. MODIFIED PARCEL
TAKEN WITH A T/TD OF 83/67 YIELDS SBCAPE ON THE ORDER OF
1500-1800 J/KG BY 18-20Z. UNDER THE BACKGROUND OF THIS MODIFYING
THERMODYNAMIC PROFILE...ENVIRONMENT CERTAINLY LOOKING SUPPORTIVE OF
MORE SUBSTANTIVE UPDRAFT STRENGTH. RECENT RUC ANALYSIS PAIRED WITH
WATER VAPOR AND LATEST HI RES SOLUTIONS SUGGEST CONVECTIVE
INITIATION WILL TEND TO ANCHOR ON SOME COMBINATION OF AN INBOUND
REMNANT MCV/PERTURBATION NOW EJECTING NORTHEAST OUT OF THE ARKANSAS/
MISSOURI BOOTHEEL AND A LEAD PRE-FRONTAL TROUGH AXIS. THE TROUGH
MAY BE HELPING SUSTAIN THE LIGHT RETURNS AND CLOUD DEBRIS
CURRENTLY STREAMING FROM SOUTHWEST LOWER MI INTO THE TRI-CITIES
AT THE MOMENT. THE DEEP LAYER LARGELY UNIDIRECTIONAL WIND FIELD
WILL BE IMPROVING WITH TIME...A NOTED UPTICK WITHIN THE 800-700 MB
LAYER BY LATE AFTERNOON SEEMINGLY SUPPLYING ADEQUATE ENOUGH SHEAR
TO SUSTAIN ORGANIZED STRUCTURES WITHIN THIS MODULATING PRE-FRONTAL
WARM SECTOR. THIS CONTINUES TO POINT TOWARD AT THE VERY LEAST A
MARGINAL RISK FOR STRONG WIND GUSTS...WITH A PLAUSIBLE SCENARIO
FOR A GREATER COVERAGE IN LIGHT OF ERODING CONCERNS OVER POTENTIAL
BOUNDARY LAYER HEATING. HEAVY RAINFALL ALSO A POTENTIAL ISSUE
GIVEN THE ELEVATED PWAT VALUES...PARTICULARLY HEADING INTO THE
EVENING AS THE FORWARD PROPAGATION OF THE INBOUND FRONTAL SLOPE
SLOWS WITH TIME.
PREV DISCUSSION...ISSUED 331 AM EDT TUE MAY 13 2014
SHORT TERM...TODAY AND TONIGHT
AS OF 07Z...THE SURFACE WARM FRONT APPEARS TO HAVE CLEARED THE TRI
CITIES AND BAD AXE AND IS NOW HUGGING THE LAKE HURON
SHORELINE...WHERE THE MARINE LAYER HAS PROVEN A FORMIDABLE OBSTACLE
IN THE NORTHEAST PROGRESS OF THIS FRONT. SFC LOW PRESSURE CENTERED
OVER FAR WRN LAKE SUPERIOR WILL LIFT INTO NORTHERN ONTARIO TODAY IN
ADVANCE OF A MID LEVEL SHORT WAVE NOW LIFTING UP THROUGH MINNESOTA.
DESPITE THE STEADY STATE NATURE OF THE LONG WAVE TOUGH OVER THE
PLAINS AND MID LEVEL RIDGE OVER THE NORTHERN LAKES...THE SFC COLD
FRONT /NOW EXTENDING ACROSS CNTL WI AND WRN IL/ WILL BE DRIVEN
ACROSS SE MI BETWEEN 21Z AND 02Z THIS EVENING AS THE SFC LOW LIFTS
NORTH. STRENGTHENING LOW LEVEL S-SW FLOW IN ADVANCE OF THE FRONT
WILL HOLD THE WARM FRONT NORTH OF THE AREA...POSSIBLY PUSHING IT
OFFSHORE OF THE THUMB.
EXTENSIVE PREFRONTAL THUNDERSTORMS YESTERDAY HAVE LED TO NUMEROUS
CONVECTIVELY INDUCED MID LEVEL SHORT WAVES. A PAIR OF THESE MCVS NOW
STRETCHING FROM IL TO CNTRL LAKE MI WILL TRACK ACROSS WRN AND CNRL
LOWER MI THIS MORNING AND EARLY AFTERNOON. ENHANCED LIFT ASSOCIATED
WITH THESE FEATURES WILL LIKELY ALLOW SOME CONVECTION TO PECULATE
WELL IN ADVANCE OF THE SFC COLD FRONT. SOME OF THIS CONVECTION MAY
INFILTRATE AT LEAST THE WESTERN PORTIONS OF THE FORECAST AREA
THROUGH EARLY AFTERNOON. WITH SE MI FIRMLY WITHIN THE WARM
SECTOR...TEMPS SHOULD HAVE NO PROBLEM RISING WELL INTO THE 70S TODAY
/PERHAPS SOME LOW 80S OVER THE EAST/ EVEN WITH SOME RESIDUAL
CONVECTIVE CLOUD DEBRIS. ASSUMING AFTERNOON TEMPS REACH UPPER 70S
WITH SFC DEWPOINTS IN THE MID/UPPER 60S...SB CAPE SHOULD REACH 1500
J/KG. WITH 0-6KM BULK SHEAR AROUND 35 KNOTS...A FEW STRONG TO
POTENTIALLY SEVERE STORMS STILL LOOK POSSIBLE /STRONG WINDS BEING
THE MAIN HAZARD/. THE DEEP LAYER MOISTURE AND THUS LOW CAPE DENSITY
ALONG WITH UNCERTAINTY AS TO HOW MUCH WARMING WILL OCCUR IN THE
BOUNDARY LAYER TODAY SEEM TO BE THE MAIN LIMITING FACTORS FOR THE
INCLUSION OF SE MI IN A SLIGHT RISK FOR SEVERE WEATHER AT THIS TIME.
GIVEN THE RATHER GOOD DENSITY GRADIENT ALONG THE SFC COLD
FRONT...LOW LEVEL CONVERGENCE SHOULD STILL PROVE EFFICIENT IN
PROVIDING A GENEROUS COVERAGE OF CONVECTION LATE THIS AFTERNOON AND
EVENING. WITH PRECIP WATER AROUND 1.6 INCHES AND FAIRLY HIGH DEEP
LAYER MEAN RH...THUNDERSTORMS WILL AGAIN BE CAPABLE OF PRODUCING
FAIRLY INTENSE RAINFALL RATES. THE SLOW MOVEMENT OF THE SFC COLD
FRONT DUE TO THE MEAN DEEP LAYER FLOW NEARLY PARALLELING THE FRONT
COULD AGAIN POSE SOME LOCALIZED HIGH RAINFALL AMOUNTS AND FLOODING.
WHILE THE SFC FRONT AND INSTABILITY WILL SLIDE EAST OF THE AREA BY
03Z...GOOD FGEN WITHIN THE 925-850MB LAYER AND AMPLE DEEP LAYER POST
FRONTAL MOISTURE SHOULD SUSTAIN SHOWERS OVER MUCH OF THE AREA WELL
INTO THE NIGHT.
LONG TERM...
THE LONGWAVE NORTH AMERICAN TROUGH CENTERED JUST EAST OF THE ROCKIES
WILL UNDERGO FURTHER PHASING/CONSOLATION OF UPPER LEVEL PV AS
SOUTHERN ENERGY EJECTS OUT OF THE FOUR CORNERS REGION...LEADING TO
DEEPENING AND CLOSED 500 MB LOW OVER THE MIDWEST ON THURSDAY.
ABUNDANT RESERVOIR OF MOISTURE...BOTH PACIFIED AND GULF OF MEXICO
MOISTURE OVER EASTERN MEXICO WILL BE SURGING NORTHWARD ONCE
AGAIN...ALLOWING RAIN TO DEVELOP LATE WEDNESDAY
AFTERNOON...PERSISTING AT LEAST INTO THURSDAY...AS DEEPENING SURFACE
LOW TRACKS FROM THE WESTERN GULF COAST STATES...NORTH/NORTHEAST
THROUGH THE CENTRAL OHIO VALLEY AND THROUGH/OR CLOSE TO SOUTHEAST
MICHIGAN. PER 00Z NAM...EXCELLENT LARGE SCALE ASCENT FOR AN EXTENDED
PERIOD...COUPLED WITH THE GOOD MOISTURE (850 MB DEW PTS OF 10+
C...700 MB DEW PTS UP AROUND 2 C)...MODEST INSTABILITY (SHOWALTER
INDEX DROPPING TO ZERO OR SLIGHTLY NEGATIVE BY THURSDAY
MORNING)...WILL RESULT IN RAIN...HEAVY AT TIMES...AND WIDESPREAD
RAINFALL IN EXCESS OF 1 INCH APPEARS POSSIBLE...WHICH WOULD LIKELY
LEAD TO ADDITIONAL FLOODING CONCERNS WITH RECENT HEAVY
RAINFALL/ALREADY SOAKED GROUND/ELEVATED RIVERS. TROUGH AXIS
POTENTIALLY GOING NEGATIVELY TILTED THURSDAY NIGHT MAY PROLONG THE
RAIN A BIT LONGER. HOWEVER...THE 00Z EURO HAS COME IN MUCH WEAKER
LOW/SOLUTION THAN ITS 12Z RUN...AND THUS SHOWS THE MAJORITY OF RAIN
OCCURRING BEFORE 12Z THURSDAY AS THE MID LEVEL DRY SLOT TAKES HOLD
ON THURSDAY.
DRYING OUT AS WE HEAD INTO THE WEEKEND...BUT COLDER TEMPERATURES
WILL BE THE WEATHER STORY...AS COLD POOL ALOFT MOVES OVER THE GREAT
LAKES REGION...AND 00Z MODELS CONTINUE TO SHOW 850 MB TEMPS DIPPING
SLIGHTLY BELOW ZERO FOR FIRST HALF OF THE WEEKEND. THIS COLDER
AIRMASS WILL LEAD TO STEEP LOW LEVEL LAPSE RATES DURING THE
AFTERNOON HOURS...SUFFICIENT FOR CU UP AND ISOLATED-SCATTERED
SHOWERS...WITH FROST POSSIBLE AT NIGHT AS CLOUDS TEND TO DISSIPATE.
MARINE...
WARM AND MOIST AIR LIFTING OVER THE COLDER WATERS OF LAKE HURON IS
EXPECTED TO PRODUCE AREAS OF DENSE FOG TODAY...ALONG WITH ADDITIONAL
SHOWERS AND THUNDERSTORMS...AS COLD FRONT SWEEPS THROUGH THE CENTRAL
GREAT LAKES LATE TODAY. OUTSIDE OF ANY THUNDERSTORMS...WINDS ARE
EXPECTED TO REMAIN UNDER 20 KNOTS AS THEY GRADUALLY VEER FROM A
SOUTHERLY DIRECTION TO THE WEST BEHIND THE COLD FRONT. LIGHT WINDS
ON WEDNESDAY WILL GIVE WAY TO INCREASING NORTHEAST WINDS AS A LOW
TRACKS INTO SOUTHWESTERN ONTARO. FUNNELING THROUGH SAGINAW BAY COULD
PRODUCE WIND GUSTS OF 25 TO 30 KNOTS ON THURSDAY AS COLDER AIR
FILTERS IN THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
DENSE FOG ADVISORY...LHZ363-LHZ421-LHZ441-LHZ442-LHZ443-LHZ462-
LHZ463-LHZ464...UNTIL 8 AM WEDNESDAY.
DENSE FOG ADVISORY...LHZ362...UNTIL 4 AM WEDNESDAY.
DENSE FOG ADVISORY...LHZ361...UNTIL 11 PM TUESDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
UPDATE.......MR
SHORT TERM...SC
LONG TERM....SF
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
126 PM EDT TUE MAY 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 507 AM EDT TUE MAY 13 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATED AN AMPLIFIED TROF
OVER THE CNTRL CONUS. WITHIN THE TROF...ONE SHORTWAVE WAS LIFTING
THRU NRN MN INTO NRN ONTARIO. ANOTHER SHORTWAVE WAS LINGERING IN THE
BASE OF THE TROF OVER NM/CO. THIS SHORTWAVE MAY BRING SOME
INTERESTING WEATHER LATER THIS WEEK DEPENDING ON HOW IT INTERACTS
WITH OTHER NRN STREAM ENERGY DIVING INTO THE TROF. WITH THE
SHORTWAVE LIFTING INTO NRN ONTARIO...SFC LOW PRES WAS TRACKING N
ACROSS WRN LAKE SUPERIOR. OCCLUDED FRONT WAS SWEEPING INTO WRN UPPER
MI WHILE SFC WARM FRONT IS STILL HELD UP S OF UPPER MI.
FORTUNATELY...LITTLE PCPN HAS FALLEN SINCE SHRA MOVED THRU THE FCST
AREA YESTERDAY MORNING/EARLY AFTN. THIS WILL HELP EASE RISES ON
RIVERS THAT HAVE HIGH FLOWS.
AS OCCLUDED FRONT MARCHES ACROSS THE AREA THIS MORNING/EARLY AFTN...
WILL MAINTAIN A SHRA CHC ALONG/AHEAD OF IT. THERE MAY YET BE SOME
THUNDER OVER THE ERN FCST AREA...BUT POTENTIAL LOOKS LIMITED WITH
LITTLE INSTABILITY. MEANWHILE...FOG...LOCALLY DENSE...WILL LIFT
QUICKLY WITH FROPA. OTHER ITEM OF NOTE TODAY IS THAT HEALTHY CAA
WILL AID GUSTY WINDS...ESPECIALLY ACROSS THE KEWEENAW UNDER
FAVORABLE WESTERLY WIND DIRECTION. GUSTS SHOULD BE UP TO AROUND 40KT
AT TIMES THERE.
DRY WEATHER WILL FOLLOW FOR TONIGHT UNDER DRY AIR MASS. LOWS WILL
FALL INTO THE 30S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 450 AM EDT TUE MAY 13 2014
DEEP TROUGHING IN PLACE ON WEDNESDAY AND THIS MAY ONLY DEEPEN FURTHER
BY LATE THIS WEEK AS AN UPPER LOW SLIDES ACROSS THE GREAT LAKES.
UPPER LOW WILL ONLY SLOWLY EXIT THE UPPER GREAT LAKES THIS WEEKEND.
NOT A LOT OF PRECIPITATION WITH THE EXPECTED PATTERN /THOUGH FRIDAY
IS STILL UNCERTAIN/...BUT IT WILL REMAIN UNSETTLED AND COOL INTO AT
LEAST FIRST PART OF WEEKEND. AND STILL CANNOT COUNT OUT POTENTIAL
FOR ACCUMULATING SNOW AROUND FRIDAY THOUGH THE MODEL LEADING THE
CHARGE ON THAT IDEA THE LAST SEVERAL DAYS...THE ECMWF...HAS BACKED
AWAY FROM THAT IDEA WITH MOST RECENT MODEL RUN...AS HAS THE GEM-NH
AND THE UKMET WHICH WAS TRACKING ALONG WITH THE ECMWF FOR A WHILE
NOW. ONLY TIME WILL TELL IF THIS IS A TREND OR A TEMPORARY SHIFT.
WEDNESDAY STILL APPEARS GENERALLY QUIET. SFC LOW WILL BE OVER
NORTHERN ONTARIO WITH GRADIENT WESTERLY FLOW OVER LK SUPERIOR/UPR
MICHIGAN. GRADIENT WEAKENS ENOUGH IN THE AFTN TO RESULT IN LAKE
BREEZES. FORCING WEAKER THAN IT LOOKED 24 HR AGO AND MOISTURE RATHER
PALTRY. EVEN THOUGH THERE MAY BE BUILD UP OF HIGHER BASED CU...NOT
EXPECTING ANY SHRA IN LAKE BREEZE CONVERGENCE AREAS OF CNTRL UPR
MICHIGAN. DWPTS START DAY AROUND 30F AND MIXED LAYER DWPNT OUTPUT
POINTED TO AROUND 20 FOR INTERIOR WEST BY MID AFTN. PRETTY FEASIBLE
GIVEN THE DEPTH OF MIXING. FOR NOW DROPPED DWPNTS INTO LOW-MID 20S
WHICH RESULTS IN RH VALUES AROUND 30 PCT. FIRE WX ISSUES WILL BE
MITIGATED BY RECENT RAINFALL AND SINCE WINDS SHOULD REMAIN MAINLY
BELOW 15 MPH.
WEDNESDAY NIGHT FEATURES CONTINUED QUIET WEATHER PATTERN WITH INCREASING
NORTH GRADIENT FLOW AS HIGH PRESSURE BUILDS OVER MANITOBA/ONTARIO AND
LOW PRESSURE WAVE DEEPENS OVER OHIO VALLEY AND BEGINS TO LIFT NORTH
TO THE CENTRAL GREAT LAKES REGION. MID-HIGH CLOUDS INCREASE WHICH
WILL KEEP MIN TEMPS ABOVE FREEZING MAJORITY OF CWA.
THURSDAY INTO FRIDAY...SHORTWAVE ROUNDS BASE OF PRIMARY TROUGH ALOFT
WHILE SECONDARY JET STREAK DIGS ACROSS THE ROCKIES INTO THE WESTERN
SIDE OF THE UPPER LEVEL TROUGH. RESULT IS TROUGH ALOFT BECOMING
NEGATIVE TILTED THEN CLOSING OFF BY FRIDAY. STRONGEST SHORTWAVE
WITHIN THE TROUGH LIFTS NORTHWARD. IT IS THIS SHORTWAVE AND
ASSOCIATED SFC LOW THAT HOLDS THE KEY FOR THE THURSDAY NIGHT AND
FRIDAY FORECAST. RECENT RUNS OF THE ECMWF WERE THE MOST WRAPPED UP
AND FARTHER WEST WITH THIS WAVE AND ASSOCIATED SFC LOW. GFS MOSTLY
HAS STAYED PROGRESSIVE AND FARTHER EAST WITH THE LOW...LIFTING IT
NORTHWARD OVER THE LOWER LAKES INSTEAD OF THE CENTRAL GREAT LAKES.
LATEST ECMWF/UKMET/GEM-NH GOING THAT WAY TOO. SEEMS THAT ECMWF HAS
MORE SHORTWAVE ENERGY AHEAD OF THE TROUGH THAN WAS THERE PERVIOUSLY.
THIS RESULTS IN UPPER TROUGH STAYING MORE OPEN/POSITIVELY TILTED
WHICH KEEPS THAT MAIN SHORTWAVE JUST A BIT FARTHER EAST. AT THE SAME
TIME...ECMWF ENSEMBLE MEAN AND A FAIR AMOUNT OF ENSEMBLES FROM THE
GEM STILL CONTINUE TO SUPPORT POTENTIAL FOR FARTHER WEST SFC LOW...
SO THAT IDEA MAY NOT BE DONE JUST YET.
PRIMARY CHANGE TO THE GOING FORECAST WAS TO GO BACK TO RAIN/SNOW
SHOWERS IDEA INSTEAD OF WIDESPREAD RAIN/SNOW...BOOSTED BY DAYTIME
HEATING DUE TO INSTABILITY ALOFT WITH THE UPPER TROUGH. STILL KEPT
TEMPS CHILLY ON FRIDAY AS THERE SHOULD BE BKN-OVC SKIES WITH NORTH OR
NORTHEAST WINDS OFF LK SUPERIOR...EVEN WITHOUT A STRONGER SYSTEM.
INITIAL PLAN WAS TO PUT A MENTION OF ACCUMULATING SNOW IN THE MORNING
HAZARDOUS WEATHER OUTLOOK AND EHWO GRAPHICS...BUT SINCE THE MODEL
THAT WAS SHOWING THIS MOST PERSISTENTLY BACKED AWAY...WILL NOT PUT
THAT MENTION IN THERE AFTER ALL. PROBABLY NOT TOO MUCH OF A STRETCH
TO SAY THAT WILL BE FINE WITH MOST PEOPLE THAT ARE TRYING TO PUT THIS
LONG COLD WINTER...AND EARLY SPRING...BEHIND THEM.
TROUGHING GRADUALLY PULLS AWAY DURING THE WEEKEND...BUT COULD STILL
SEE POTENTIAL FOR SOME LINGERING RAIN/SNOW SHOWERS ON SATURDAY WITH
FAIR AMOUNTS OF CLOUDS. LOOKS LIKE WE WILL BE IN THE CLEAR FOR
SUNDAY AND PROBABLY MONDAY AS WELL...WITH THE RETURN OF WARMER
TEMPERATURES...ALBEIT STILL BELOW NORMAL. READINGS MAY REACH MID TO
UPR 60S INLAND WEST WHILE MOST OTHER AREAS ARE IN THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 124 PM EDT TUE MAY 13 2014
WITH ABUNDANT LLVL MSTR SHOWN ON THE 12Z INL/MPX RAOBS...SLOWED
TREND TO VFR A BIT. BUT DAYTIME HEATING/MIXING THAT MAINTAINS GUSTY
W WINDS SHOULD ALLOW IMPROVEMENT TO VFR AT ALL 3 SITES THIS AFTN...
SLOWEST AT THE MORE EXPOSED CMX LOCATION WITH STRONGER...MOST
PRONOUNCED UPSLOPE WIND COMPONENT. THEN VFR CONDITIONS AND LIGHTER
WINDS WL PREVAIL INTO WED WITH DRY HI PRES/WEAKER PRES GRADIENT
DOMINATING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT TUE MAY 13 2014
LOW PRESSURE OVER WESTERN LK SUPERIOR WILL MOVE NORTHWARD TOWARD
HUDSON BAY TONIGHT INTO WEDNESDAY. A COLD FRONT CROSSES THE REGION
THIS MORNING SHIFTING WINDS FROM EASTERLY TO WESTERLY. WEST WINDS BY
AFTERNOON COULD REACH 30 KTS OVER PORTIONS WESTERN AND NORTH CENTRAL
LAKE SUPERIOR. THESE GUSTY WINDS WILL DIMINISH BELOW 25 KTS LATE
TONIGHT INTO WEDNESDAY MORNING. WINDS FOR THE REST OF THE WEEK WILL
MAINLY BE BLO 20 KTS. THERE DOES REMAIN SOME POTENTIAL THAT
NORTHERLY WINDS ON FRIDAY MAY REACH 30 KTS DEPENDING ON THE TRACK
AND STRENGTH OF A LOW PRESSURE SYSTEM LIFTING ACROSS THE GREAT LAKES.
&&
.HYDROLOGY...
ISSUED AT 450 AM EDT TUE MAY 13 2014
TOTAL RAINFALL AMOUNTS FROM THIS SYSTEM ENDED UP LESS THAN EXPECTED
WHICH IS RESULTING IN LESSER OVERALL RISE ON RIVERS THAN COULD HAVE
OCCURRED. ADDITIONAL RAINFALL THE NEXT COUPLE DAYS WILL BE MINIMAL.
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION...POSSIBLY IN THE FORM
OF RAIN AND SNOW...COULD ARRIVE THURSDAY NIGHT INTO FRIDAY.
HOWEVER...THE LATEST DATA IS NOT AS STRONG WITH THIS SYSTEM WHICH
RESULTS IN SCATTERED RAIN AND SNOW SHOWERS WITH ONLY LIGHT TOTAL
LIQUID EQUIVALENT PRECIPITATION. NO CHANGES HAVE BEEN MADE TO FLOOD
WARNINGS FOR THE STURGEON RIVER NEAR CHASSELL AND FOR THE MICHIGAMME
RIVER NEAR REPUBLIC...WITCH LAKE...AND TO THE EAST OF CRYSTAL FALLS
JUST DOWNSTREAM FROM WAY DAM AND HEMLOCK FALLS. SINCE NOT AS MUCH
RAIN OCCURRED OVER STURGEON RIVER BASIN IN BARAGA COUNTY THE LAST
SHIFT COORDINATED WITH THE NORTH CENTRAL RIVER FORECAST CENTER NEAR
MINNEAPOLIS AND REPLACED THE WARNING FOR THE STURGEON RIVER NEAR
ALSTON WITH AN ADVISORY.
DUE TO THE RAINFALL THAT DID OCCUR AND ONGOING SNOWMELT OVER THE
HIGHER TERRAIN OF MAINLY NORTHWEST AND NORTH CENTRAL UPPER
MICHIGAN...RIVER FLOWS WILL LIKELY REMAIN HIGH THROUGH THE REST OF
THE WEEK. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD
CONTINUE TO MONITOR THE LATEST RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...KC
MARINE...JLA
HYDROLOGY...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1230 PM CDT TUE MAY 13 2014
.UPDATE...FOR 18Z AVIATION DISCUSSION BELOW...
ISSUED AT 1223 PM CDT TUE MAY 13 2014
UPDATE ISSUED AT 1015 AM CDT TUE MAY 13 2014
ADDED SCA TO MARINE FORECAST TODAY. ALTHOUGH SUSTAINED WINDS
MAY NOT REACH CRITERIA SPECIFICALLY...SHOULD BE ENOUGH ABOVE THRESHOLD
GUSTS WITHIN THE POST FRONTAL REGIME TO CAUSE SOME HAZARD.
UPDATE ISSUED AT 1012 AM CDT TUE MAY 13 2014
MOSTLY CLOUDY SKIES COVER MOST OF THE FORECAST AREA WITH SOME
BREAKS IN NE MN. RADAR INDICATES LIGHT RAIN/DRIZZLE ACROSS SOME
AREAS OF NE MN WITH DRIZZLE REPORTED IN NW WI. HRRR INDICATES SOME
CELLULAR SHOWERS DEVELOPING THIS AFTERNOON WITH THE AFTERNOON
HEATING. WILL EXTEND POPS INTO NW WI FOR THIS AFTERNOON. ALSO
LOWERED TEMPS A COUPLE DEGREES BASED ON CLOUD COVER AND CURRENT
TRENDS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 338 AM CDT TUE MAY 13 2014
THE SURFACE LOW WAS LOCATED OVER THE ARROWHEAD OF MINNESOTA AS OF
08Z WITH THE UPPER TROUGH EXTENDING THROUGH MANITOBA INTO THE
DAKOTAS/WESTERN MINNESOTA. THE RAIN HAS DIMINISHED QUITE A BIT
ACROSS THE AREA WITH MAINLY SOME VERY LIGHT RAIN/DRIZZLE IN SPOTS.
WE EXPECT MINIMAL COVERAGE/INTENSITY OF THE PRECIP THIS MORNING AS
THE SURFACE LOW CONTINUES TO MOVE NORTHEAST. COLDER AIR CONTINUES
TO MOVE ACROSS THE REGION BEHIND THE DEPARTING LOW. SNOW WAS
REPORTED AT SEVERAL OBSERVATIONS...INCLUDING
KVWU/KBDE/KFGN/KRRT/CYQK. RADAR SHOWS SOME OF THAT MAY AFFECT KINL
THIS MORNING...AND WE HAVE A CHANCE FOR SOME SNOW OVER OUR
NORTHERN ZONES THROUGH 16Z.
SHOWERS SHOULD DEVELOP ACROSS MUCH OF OUR MN ZONES INTO FAR
NORTHWEST WI THIS AFTERNOON. COLD TEMPS ALOFT AND SOME SHORTWAVE
ENERGY WILL HELP PROVIDE A FAVORABLE SET UP FOR AT LEAST SOME
SCATTERED SHOWERS IN SPOTS. WE EXPECT THE BOUNDARY LAYER TO WARM
ENOUGH FOR MAINLY RAIN...BUT WOULD NOT BE SURPRISED TO HEAR OF SOME
LOCALIZED SNOW SHOWERS/SLEET INTO THE AFTERNOON IF CORES ARE
STRONG ENOUGH. HIGHS SHOULD REACH THE UPPER FORTIES TO LOWER
FIFTIES.
WE KEPT A MENTION OF SHOWER INTO THE EVENING OVER PORTIONS OF
NORTHEAST MN...THEN WENT DRY LATE EVENING ON. LOWS WILL DROP INTO
THE THIRTIES.
THE UPPER TROUGH WILL MOVE A BIT FURTHER EAST INTO MINNESOTA ON
WEDNESDAY. WE HAVE CHANCE FOR MORE SHOWERS ACROSS NORTHEAST MN AND
FAR NORTHWEST WI FROM LATE MORNING INTO THE AFTERNOON. TEMPS ALOFT
REMAIN RATHER COLD...SO WE DO MENTION SOME SNOW SHOWERS OVER FAR
NORTHERN MINNESOTA AGAIN. WE WENT ALL RAIN SHOWERS LATE WEDNESDAY
MORNING INTO THE AFTERNOON...BUT AGAIN SOME ISOLATED MIXED
RAIN/SNOW SHOWERS MAY OCCUR IF PRECIP RATES ARE HIGH ENOUGH. HIGHS
WILL RANGE FROM THE UPPER FORTIES TO MID FIFTIES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 AM CDT TUE MAY 13 2014
THE EXTENDED PERIOD WILL BE DOMINATED BY A STAGNANT UPPER TROF OVER
THE CENTRAL US THAT WILL EVENTUALLY CLOSE OFF...AGAIN...LATE IN THE
WEEK. THIS WILL KEEP THE NORTHLAND IN A SOMEWHAT CLOUDY...COOL AND
WET PATTERN, ALTHOUGH THE WETTEST PERIOD IS PROBABLY BEHIND US.
A COLD FRONT WILL MOVE ACROSS THE NORTHLAND WEDNESDAY...BUT UPPER
TROF COULD KEEP SHOWERS LINGERING INTO THE EVENING...MAINLY IN
EASTERN AREAS OF CWA. BUT THAT WILL BE SHORT-LIVED AS EXPECT SOME
SHOWERS TO POP UP THURSDAY AS A COLD POOL ALOFT WILL CAUSE STEEP
ENOUGH LAPSE RATE TO GENERATE SOME SHOWERS. WITH TORRIDNESS SLOW TO
MOVE OUT...EXPECT THE SHOWERS TO CONTINUE IN THE EASTERN SECTIONS
INTO FRIDAY. WITH THE UPPER LOW CLOSING OFF OVER THE
AREA...NORTHERN WISCONSIN OR WESTERN LAKE SUPERIOR...KEPT SHOWERS
INT HE FORECAST IN THE EAST INTO SATURDAY...BUT CHANCES ARE SMALL.
IT WILL BE QUITE COOL WITH 8H TEMPS FALLING TO -4 TO -8 AND STAYING
PUT THROUGH FRIDAY. SO SOME BELOW FREEZING TEMPS EXPECTED. THE
CLOSED LOW WILL SLOWLY MOVE EAST ROUGH THE PERIOD AND BY LATE IN THE
WEENED BE EITHER OVER CENTRAL OT OR THE UP OF MI. BUT THIS ALLOW
SOME SUN AND DRYING OVER THE WEEKEND. THEN ON MONDAY ANOTHER LOW
WILL DIG INTO THE WEST COAST AND PROVIDE ANOTHER SFC LOW TO MOVE
TOWARD THE REGION FOR THE REST OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1223 PM CDT TUE MAY 13 2014
LARGE AREA OF CLOUDS WITH MVFR/LOW VFR CEILINGS CONTINUES TO SWEEP
OVER THE AREA IN THE WAKE OF THE RECENTLY DEPARTED SFC LOW. GUSTY
WINDS ATTRIBUTED TO SFC PRESS GRADIENT IN ADDITION TO MECHANICAL
MIXDOWN OF HIGHER WINDS ALOFT. VCSH INCLUDED AT MOST TERMINALS
NEXT SEVERAL HRS DUE TO CONVECTIVE INSTABILITY THIS AFTN. ALTHOUGH
SOME DISSIPATION OF CU MAY OCCUR OVERNIGHT WITH LESS INSTABILITY...SHOULD
SEE A TREND TOWARDS MORE VFR CUMULUS WED LATE MORNING AND THROUGH
THE AFTN.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 34 51 32 / 30 20 20 10
INL 46 31 47 30 / 50 40 40 10
BRD 51 34 54 32 / 30 20 30 10
HYR 49 34 57 32 / 30 10 10 10
ASX 47 34 52 31 / 30 10 10 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR
LSZ140>147.
&&
$$
SHORT TERM...MELDE
LONG TERM...CLC
AVIATION...CANNON
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
649 PM EDT TUE MAY 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH
THURSDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. A COLD FRONT
WILL SLOWLY MOVE EAST ON FRIDAY WITH A SOAKING RAIN.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
6 PM UPDATE...LATEST LOCAL RADAR IMAGERY SHOWS THE BACKDOOR COLD
FRONT ABOUT TO MOVE THROUGH THE LOCAL BGM AREA. THIS FEATURE
EXTENDS UP THROUGH THE WESTERN MOHAWK VALLEY AND SOUTH ACROSS THE
WYOMING VALLEY. LOCATIONS EAST OF THE FEATURE ARE IN THE LOWER TO
MIDDLE 70S WHILE OVER THE CENTRAL SOUTHERN TIER AND FINGER LAKES
AREA ITS IN THE LOWER TO MIDDLE 80S. THIS BOUNDARY IS EXPECTED TO
REACH THE CENTRAL SOUTHERN TIER AND EASTERN FINGER LAKES BEFORE
STALLING AND MOVING BACK EAST. ISOLATED CONVECTION MAY FIRE ALONG
THIS BOUNDARY UNTIL EARLY EVENING WHEN CAPE AND LOW LEVEL LAPSE
RATES WILL LESSEN. CONVECTION OVER GEORGIAN BAY WHICH IS ASSOCIATED
WITH COLD FRONT MAY MOVE INTO THE NRN PTN OF CWA LATE TONIGHT BUT
BOUNDARY WILL SLOW OVERNIGHT AND CONVECTION WILL MOVE INTO A MUCH
MORE STABLE ENVIRONMENT BY THEN.
3 PM UPDATE...
A WEAK WARM FRONT IS ACROSS THE AREA WITH DEWPOINTS IN THE L60S
IN THE WEST. AS THE WARM FRONT LIFTS NE WITH A WEAK WAVE A FEW
SHOWERS AND MAYBE A TSTORM WILL GET GOING LATE TODAY AND THIS EVE.
THE UL RIDGE ALSO MOVES THROUGH CREATING A DEEPER SOUTHERLY FLOW
OF WARM AND MOIST AIR INTO THE CWA. WITH THE HIGH DEWPT
TEMPS...MIN TEMPS WILL VARY WIDELY FROM U40S EAST TO A60 FAR WEST.
DEWPTS DROP AS THE NIGHT GOES ON WITH THE EXIT OF THE WARM FRONT
AND THE COLD FRONT NEARLY STATIONARY IN ERN MICIGAN.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
3 PM UPDATE...
WED AND THU WILL BE SIMILAR TO THE LAST 2 DAYS. WEAK FORCING AND
MORE COVERAGE LATE IN THE DAY WITH DIURNAL HEATING. WED WILL BE
BETTER THAN THU AS A COLD FRONT MOVES EAST INTO NW NY THEN LIFTS
NORTH WED NGT. THU LITTLE FORCING AS WE WAIT FOR THE MAIN SHOW
WHICH IS THE COLD FRONT. A SFC LOW WILL MOVE NORTH UP THE MISS
VALLEY TO MICHIGAN THEN INTO QUEBEC AHEAD OF A DEEP DIGGING UPPER
LEVEL LOW OVER THE MIDWEST. THIS STALLS OVER THE GREAT LAKES BUT
KEEPS THE COLD FRONT MOVING THROUGH THE CWA FRIDAY. WITH THE FRONT
WILL BE A BAND OF HEAVY RAIN OF WIDESPREAD 1 TO 2 INCHES. HIGHER
AMOUNTS POSSIBLE WHICH COULD CAUSE MINOR ISOLATED HYDRO PROBLEMS.
THIS RAIN HELPED BY GOOD LIFT AND FORCING AND PWATS OF 2 TO 3
STANDARD DEVIATIONS ABOVE NORMAL. DEWPTS 60S AND TROPICAL
MOISTURE. WITH RIVERS NEAR NORMAL 1 TO 2 INCHES WOULD MOST LIKELY
NOT CAUSE ANY FLOODING.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
230 PM UPDATE...
MED RANGE MODELS INDICATING CDFNT WL BE BISECTING CWA AT BEGINNING
OF LONG TERM. HV GONE WITH LKLY/CATEGORICAL POPS EAST OF I-81 WITH
CHC FURTHER BACK TO THE WEST. MAINLY SHOWERS EXPECTED FOLLOWING
FROPA. REMAINDER OF LONG TERM WL FEATURE SHOWERS EACH PD COURTESY
OF UPR LVL LOW HANGING BACK TO THE WEST. AS IS TYPICAL IN THESE
CASES, EXPECT THAT AFT 12Z SATURDAY MOST OF THE SHOWERS WL BE OF
THE MORE HIT AND MISS VARIETY WITH MOSTLY MISSES. THUS, THRU THE
END OF THE LONG TERM WL KEEP 20-30 POPS OVR ENTIRE CWA.
TEMPS DRG THE PD EXPECTED TO BE BLO NRML UNDER EXTENSIVE CLD CVR.
FOLLOWED WPC GRIDS FOR THE LONG TERM WITH NO SIGNIFICANT
DISCREPANCIES BTWN MED RANGE GUIDANCE.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
THE NAM AND RAP MODELS ARE BACKING OFF ON THE EXTENT OF THE
PROJECTED MARINE LAYER FOR THE OVERNIGHT HOURS. OUR LATEST
FORECAST INCLUDES A TEMPO PERIOD FOR MVFR TO BORDERLINE IFR
CEILINGS FROM AVP UP TO ITH.
MODEL SOUNDINGS SUGGEST A BURN OFF BETWEEN 13Z AND 15Z, THEN A
PARTLY SUNNY AFTERNOON WITH A SCATTERED CU DECK BETWEEN 3500 AND
5000 FEET.
THERE IS A SLIGHT CHANCE FOR AN AFTERNOON SHOWER OR THUNDERSTORM.
OUTLOOK...
WED NGT/THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN SHOWERS AND
THUNDERSTORMS.
THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS
COLD FRONT STALLS NEAR AREA.
SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE
AFTERNOON.
SUN...MVFR RESTRICTIONS POSSIBLE IN ISOLATED SHOWERS BUT MAINLY
VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TAC
NEAR TERM...RRM/TAC
SHORT TERM...TAC
LONG TERM...PVN
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
634 PM EDT TUE MAY 13 2014
.SYNOPSIS...
WARM AND INCREASINGLY HUMID AIR ACROSS THE REGION WILL MAINTAIN AN
UNSTABLE ENVIRONMENT WHICH WILL SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS THE REGION THROUGH WEDNESDAY NIGHT. A COLD
FRONT WILL THEN CROSS THE REGION LATER THURSDAY AND EARLY FRIDAY
WITH LIKELY SHOWERS AND THUNDERSTORMS...SOME OF WHICH MAY BRING
DOWNPOURS.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
THROUGH 530 PM...THERE WAS SIGNIFICANT INSTABILITY ACROSS INTERIOR
SECTIONS SOUTH OF LAKE ONTARIO WITH LAPS SHOWING AVERAGE CAPE
VALUES IN THE 1000 TO 1500 J/KG RANGE. DESPITE THIS...THERE HAS
BEEN LITTLE IN THE WAY OF CONVECTION SO FAR. THIS IS LIKELY TO
CHANGE SOON.
A WELL DEFINED AREA OF CONVECTION ACROSS SOUTHERN ONTARIO IS
MOVING GRADUALLY EASTWARD. THIS IS FORECAST TO WEAKEN AS IT MOVES
AHEAD OF UPPER LEVEL SUPPORT...BUT 18Z NAM AND HRRR GUIDANCE CONTINUE
TO BRING ITS REMNANTS INTO OUR REGION MID-LATE EVENING. ALSO...AS
OUTFLOWS SPREAD AHEAD OF THIS...IT IS POSSIBLE SHOWERS AND
THUNDERSTORMS WILL DEVELOP OUT AHEAD OF THIS FEATURE AS
WELL...POSSIBLY REACHING WESTERN NEW YORK BY OR SHORTLY BEFORE
SUNSET.
PRECIPITABLE WATER VALUES REMAIN QUITE HIGH...AROUND 1.3 TO 15
INCHES...SO HEAVIER RAINS ARE POSSIBLE. THE UPSIDE IS THAT THE
STEERING WINDS WILL BE STRONGER TONIGHT WITH ABOUT 20 KNOTS AT
5KFT AND 35 KNOTS AT 10KFT...SO STORMS WILL NOT LINGER AS LONG
OVER ANY INDIVIDUAL WATERSHED. THIS SAID...AREAS WHICH RECEIVED
RECENT HEAVY RAINS WILL HAVE TO BE MONITORED VERY CLOSELY AS THIS
PASSES THROUGH.
OVERNIGHT LOWS WILL BE QUITE SUMMERLIKE FOR ONE MORE NIGHT WITH
TEMPERATURES IN THE UPPER 50S TO LOWER 60S FOR THE EASTERN LAKE
ONTARIO REGION AND LOWER TO MID 60S ELSEWHERE.
WEDNESDAY WILL SEE THE CONTINUED CHANCE OF PRECIP...THE LOWER CHANCE
POPS IN THE MORNING WILL INCREASE TO LOW LIKELY POPS IN THE
AFTERNOON WITH INCREASED DAYTIME INSTABILITY. AGAIN...THE STALLED
FRONT ACTING AS THE FOCUS FOR CONVECTIVE DEVELOPMENT. HIGH TEMPS
WILL BE IN THE LOWER 70S ACROSS THE WEST WHERE THERE WILL BE A
WINDSHIFT TO NORTHWESTERLY...AND COOLER AIR INFILTRATING DURING THE
AFTERNOON...TO THE MID TO UPPER 70S ACROSS CENTRAL AND NORTHERN NY
WHERE COOLER AIR WILL BE DISPLACED BY A WARM ADVECTIVE PATTERN ON
SOUTHERLY WINDS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
VERY UNSETTLED WEATHER WILL REMAIN OVER OUR REGION DURING THIS
PERIOD...AS A DEEP TROUGH BASED OVER THE MISSISSIPPI VALLEY WILL
MAINTAIN A RICH MOISTURE PLUME THAT WILL EXTEND FROM THE GULF OF
MEXICO TO QUEBEC. THIS PROLONGED FEED OF SUB TROPICAL AIR WILL
CONTAIN PWAT VALUES OF 1.25 TO 1.5 INCHES...WHICH WILL KEEP THE
THREAT OF EXCESSIVE RAINS IN PLACE. THE GREATEST RISK FOR WIDESPREAD
SIGNIFICANT RAINFALL WILL BE DURING THE SECOND HALF OF THURSDAY INTO
FRIDAY. THE DETAILS...
AN INVERTED SFC TROUGH EXTENDING FROM THE TENNESSEE VALLEY TO THE
LOWER GREAT LAKES WEDNESDAY EVENING WILL BECOME ENERGIZED OVERNIGHT
AS A STRONG SHORTWAVE WILL LIFT OUT OF THE LOWER OHIO VALLEY. THIS
WILL ENCOURAGE A WAVE WITHIN THE TROUGH TO DEVELOP INTO A FAIRLY
WELL ORGANIZED AREA OF LOW PRESSURE...WHICH IN TURN WILL INCREASE
THE SOUTHERLY LOW LEVEL FLOW OVER OUR FORECAST AREA AND TIGHTEN A
BAROCLINIC ZONE OVER SOUTHERN ONTARIO. WHILE THERE MAY BE SOME
SHOWERS AND THUNDERSTORMS OVER OUR REGION AS A RESULT...THE BULK OF
THE NIGHT SHOULD BE RAIN FREE WITH THE BULK OF THE PCPN STAYING WEST
OF THE IAG RIVER. OTHERWISE...WE SHOULD EXPECT A VERY MILD AND
SOMEWHAT HUMID NIGHT FOR MID MAY WITH MINS GENERALLY IN THE MID 60S.
AS THE AXIS OF A 100KT H25 JET WITH ITS UPPER LEVEL LIFT PUSHES EAST
ACROSS MICHIGAN AND OHIO ON THURSDAY...AND THE AFOREMENTIONED SFC
LOW LIFTS ACROSS THE LOWER GREAT LAKES...MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS WILL BE GENERATED. THIS WILL ESPECIALLY BE THE CASE
WEST OF THE GENESEE VALLEY WHERE SOME HEAVY RAIN WILL BE POSSIBLE.
AS THE INITIAL SFC LOW WILL LIFT NORTH OF OUR REGION ON THURSDAY
NIGHT...A QUASI-STATIONARY FRONTAL BOUNDARY WILL PUSH VERY SLOWLY TO
THE EAST ACROSS OUR REGION. MEANWHILE...A 150KT JETLET IS EXPECTED
TO RACE TO THE NORTH ACROSS THE UPPER GREAT LAKES. THE LIFT PROVIDED
BY THIS JET...COUPLED WITH THE CONVERGENCE IN PROXIMITY OF THE
FRONTAL BOUNDARY...WILL PRODUCE MODERATE TO HEAVY SHOWERS AND
POSSIBLY SOME THUNDERSTORMS WITHIN THE SUB TROPICAL AIRMASS. WILL
CONTINUE TO USE CAT POPS FOR THIS PERIOD. AVERAGE BASIN RAINFALL
THURSDAY NIGHT IS FORECAST TO RANGE FROM A QUARTER INCH EAST OF LK
ONTARIO TO AN INCH OR MORE ACROSS MOST OF THE WESTERN COUNTIES.
LOCAL AMOUNTS IN EXCESS OF 1.5 INCHES WILL BE POSSIBLE OVER THE
SOUTHERN TIER.
THE SLOW MOVING FRONTAL BOUNDARY WILL THEN SLOWLY CROSS THE FINGER
LAKES AND EASTERN LAKE ONTARIO REGIONS DURING THE DAY FRIDAY. THIS
WILL KEEP THE THREAT FOR SIGNIFICANT RAINS IN PLACE FOR THE EASTERN
HALF OF OUR FORECAST AREA WHERE BASIN AVERAGE RAINFALL IS FORECAST
TO BE IN THE VICINITY OF ONE INCH. MEANWHILE...LIGHTER SHOWERS OVER
THE FAR WESTERN COUNTIES WILL TAPER OFF DURING THE COURSE OF THE
AFTERNOON.
ONE LAST WAVE OF LOW PRESSURE WILL TRACK NORTH ALONG THE SLOW MOVING
FRONTAL BOUNDARY FRIDAY NIGHT...AND THIS WILL FURTHER SLOW ITS
EASTWARD PROGRESSION...IF NOT STALLING IT FOR SOME 6 HOURS. WHILE
THE MOST UNSTABLE AIR AND DEEPEST MOISTURE FIELD AHEAD OF THE FRONT
WILL PUSH EAST ACROSS THE ADIRONDACKS...WIDESPREAD SHOWERS AND THE
CHANCE FOR LEFTOVER THUNDERSTORMS WILL REMAIN OVER THE EASTERN LAKE
ONTARIO REGION.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
IT WILL BE COOLER...AND FOR THE MOST PART...DRIER THAN THE WEEK
LEADING UP TO THIS PERIOD AS A DEAMPLIFICATION IN THE LONGWAVE
PATTERN OVER NORTH AMERICA WILL RESULT IN OUR BOUNDARY LAYER WINDS
COMING OUT OF THE EASTERN HALF OF CANADA VERSUS THE GULF OF MEXICO.
THAT IS NOT TO SAY THAT THERE WILL NOT BE THE CHANCE FOR SOME
NUISANCE SHOWERS THOUGH...AS THE LONGWAVE TROUGH THAT WAS
RESPONSIBLE FOR THE SIGNIFICANT RAINS DURING THE WEEK WILL EVOLVE
INTO A CLOSED LOW IN THE VCNTY OF NEW JERSEY.
A CORRESPONDING SFC LOW ON THE EAST SIDE OF THIS CLOSED LOW IS
FORECAST BY BOTH THE ECMWF AND GFS ENSEMBLE PACKAGES TO ROTATE
NORTHWEST TO THE NEW ENGLAND COAST. ATLANTIC MOISTURE ASSOCIATED
WITH THIS FEATURE WOULD THEN CIRCULATE BACK ACROSS OUR REGION...WITH
SOME SHOWERS POSSIBLE ACROSS THE NORTH COUNTRY ON SUNDAY...THEN
ACROSS ALL OF OUR FORECAST AREA ON MONDAY.
RIDGING IS THEN EXPECTED TO BUILD ACROSS THE LOWER GREAT LAKES IN
THE WAKE OF THE CLOSED LOW ON TUESDAY. THIS SHOULD PROMOTE MAINLY
DRY WEATHER ACROSS WESTERN NEW YORK WHILE A LOW CHC FOR RESIDUAL
SHOWERS WILL BE FOUND FURTHER EAST.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL LAST THROUGH MUCH OF THE NIGHT AS LATE DAY AND
NIGHTTIME CONVECTION IS EXPECTED TO REMAIN AWAY FROM THE TAF SITES.
SOME SHOWERS ARE POSSIBLE OVER THE SOUTHERN TIER ON WEDNESDAY
MORNING...BUT OTHERWISE MOST SENSIBLE WEATHER CAN BE COVERED WITH
VCNTY QUALIFIERS.
OUTLOOK...
WEDNESDAY THROUGH THURSDAY...VFR/MVFR WITH SCATTERED TO EVENTUALLY
MORE NUMEROUS SHOWERS AND POSSIBLE THUNDERSTORMS.
THURSDAY NIGHT AND FRIDAY...MVFR/POSSIBLE IFR IN OCCASIONAL SHOWERS
AND POSSIBLE THUNDERSTORMS. RAIN MAY BE HEAVY AT TIMES OVERNIGHT.
SATURDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
RELATIVELY LIGHT WINDS WILL CONTINUE THROUGH WEDNESDAY AS A NEARLY
STATIONARY FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE LOWER GREAT
LAKES. A SLOW MOVING FRONTAL BOUNDARY WILL THEN MOVE INTO THE REGION
AND STALL OUT ON WEDNESDAY...WITH A MODEST INCREASE IN WINDS
ACCOMPANYING ITS APPROACH. WINDS AND WAVES WILL LIKELY REMAIN BELOW
SMALL CRAFT CRITERIA THROUGH FRIDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WCH
NEAR TERM...APFFEL/WCH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...WCH
MARINE...THOMAS/WCH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
232 PM EDT TUE MAY 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH
WEDNESDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. OUR PATTERN WILL
REMAIN UNSETTLED INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...
UPDATE TO CURRENT CONDITIONS. SHOWERS OVER THE WEST WILL MOVE
SLOWLY EAST AND SOUTH TO BE FROM AVP TO BGM MIDDAY BUT DISSIPATE BY
21Z. A FEW SHOWERS LATE IN THE NW. INTENSITY OF PRECIP DYING AND
LIGHTNING STRIKES NOT AS COMMON. MESO MODELS ESP HRRR HAVE A GOOD
HANDLE ON THIS AND FOLLOWED. MAX TEMPS IN THE EAST UPPED SLIGHTLY
DUE TO MORE SUN AND HARDLY ANY RAIN SHOWERS. WHERE IT IS RAINING
NOW MAX TEMPS WILL BE LATE BUT SHOULD STILL PEAK A80.
7 AM UPDATE...
FORECAST ADJUSTED TO FOR RADAR AND MODEL TRENDS. COMPLEX DEVELOPED
ON LEADING EDGE OF 850MB JET BUT IS NOW OUTRUNNING INTO MORE
STABLE AIR AS DOES SO. PRECIPITABLE WATER VALUES TO AROUND AN
INCH-AND-A-HALF MAY LEAD TO LOCALLY HEAVY RAINFALL IN CENTRAL TWIN
TIERS AND FINGER LAKES REGION LATER TODAY. COULD LEAD TO PONDING
IN POOR DRAINAGE AREAS.
PREVIOUS DISCUSSION...
AT 430 AM...COMPLEX OF STORMS DOVE THROUGH SOUTHWEST PA THE LAST
SEVERAL HOURS...AND THEN WEAKENED. HOWEVER...NEW CONVECTION HAS
FIRED AT LEADING EDGE OF 850MB JET...ALSO COINCIDING WITH A WEAK
WAVE ALOFT...EXTENDING FROM THE ONTARIO PENINSULA TO THE WESTERN
TIP OF NY AND SOME OF WESTERN PA. MEANWHILE...JUST A FEW SHOWERS
HAVE RESULTED FROM A WEAK VORTICITY MAXIMUM NOW TRAVERSING THE NY
THRUWAY CORRIDOR...WHICH IS RUNNING INTO PROGRESSIVELY MORE STABLE
AIR AND THUS NOT MUCH OF A PLAYER IN OUR WEATHER.
EARLIER RUNS OF THE WRF-ARW...NAM...GEM...AND NMM BROUGHT NOCTURNAL
CONVECTION WITH WAVE INTO THE TWIN TIERS YET INITIALIZED WITH THE
EARLIER SW PA COMPLEX TOTALLY MISSING. THUS I SIDED HRRR AND RUC13
SOLUTIONS WHICH HAD THE SW PA COMPLEX AND AS EXPECTED KEPT THINGS
PRETTY QUIET THROUGH MOST OF THE OVERNIGHT HOURS. THE NEW
CONVECTION NOW IN WESTERN NY/PA IS AT LEADING EDGE OF 850MB
JET...BUT MODELS SHOW THAT THE JET WILL WEAKEN CONSIDERABLY THE
NEXT FEW HOURS SO I ANTICIPATE THE ASSOCIATED CONVECTION TO
DIMINISH WHILE SKIMMING SOME OF OUR SW ZONES EARLY THIS MORNING.
HIGH PRESSURE IS CURRENTLY SLIDING OUT OF QUEBEC TO MAINE/CANADIAN
MARITIME PROVINCES...INITIATING COOL AIR DAMMING DOWN THE
APPALACHIANS. SOUTHEAST LOW LEVEL FLOW WILL DEVELOP
TODAY...SETTING UP A SURFACE CONVERGENCE ZONE IN VICINITY OF
FINGER LAKES TO CENTRAL SOUTHERN TIER OF NY. I THUS HAVE PLACED
HIGH CHANCE POPS IN CENTRAL SOUTHERN TIER TO FINGER LAKES FOR LATE
MORNING TO AFTERNOON TODAY. MODEL SOUNDINGS THERE SHOW SUFFICIENT
INSTABILITY FOR THUNDER TO ACCOMPANY THOSE SHOWERS...AND
PRECIPITABLE WATER VALUES OF NEARLY AN INCH-AND-A-HALF.
HOWEVER...THE FARTHER EAST THAT ACTIVITY MANAGES TO PROCEED...THE
DEEPER INTO THE MORE STABLE SOUTHEAST FLOW /VIA COOL AIR DAMMING
ALONG EAST COAST/ IT WILL GET. THUS LOWER CHANCES FOR SHOWERS AND
ONLY SLIGHT CHANCE OF THUNDER AT MOST. I DO NOT EVEN INCLUDE
THUNDER MENTION IN WESTERN CATSKILLS TO POCONOS.
NOT QUITE AS WARM AS MONDAY...DUE TO CLOUD COVERAGE IN WEST AND
MARINE INFLUENCED LOW LEVEL FLOW IN EAST...YET STILL 70S FOR MOST OF
THE AREA. SOME LOWER ELEVATIONS IN TWIN TIERS TO FINGER LAKES
COULD EVEN STILL MANAGE 80 DEGREES.
UPPER RIDGE PASSES OVER THE REGION TONIGHT. THERE WILL BE
MARGINAL ELEVATED INSTABILITY ALOFT IN THE WESTERN ZONES...BUT
LACK OF FORCING MECHANISMS OTHER THAN WEAK WAVES TRYING TO RIDE
THROUGH THE RIDGE HAS ME HESITANT TO GO ANY HIGHER THAN SLIGHT TO
LOW CHANCE POPS. LOWS TONIGHT IN THE 50S TO LOW 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
445 AM UPDATE...
MAIN ADJUSTMENT WAS TO FURTHER DELAY THE HIGHEST RAIN CHANCES
ASSOCIATED WITH INCOMING COLD-OCCLUDED FRONTAL ZONE. THERE WILL
STILL BE SHOWERS AROUND...PARTICULARLY WEDNESDAY AS NORTHERN STREAM
SURFACE FRONT EDGES INTO THE AREA BEFORE SHIFTING BACK NORTH.
THERE WILL ALSO BE MARGINAL INSTABILITY SUPPORTING MENTION OF
THUNDER IN CENTRAL TO NORTHERN ZONES. HOWEVER...MUCH OF THE TIME
OVERALL WILL BE DRY...ESPECIALLY THURSDAY. THE SLOWER TIMING OF
INCOMING SYSTEM ALSO FORCED A WARMER ADJUSTMENT FOR HIGH
TEMPERATURES THURSDAY TO MAINLY 75-80 DEGREE RANGE...THANKS TO
WARM SECTOR FIRMLY REASSERTING ITSELF WELL AHEAD OF THE COLD
FRONT. RAIN CHANCES THEN INCREASE THURSDAY NIGHT AS THAT COLD
FRONT APPROACHES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
230 PM UPDATE...
MED RANGE MODELS INDICATING CDFNT WL BE BISECTING CWA AT BEGINNING
OF LONG TERM. HV GONE WITH LKLY/CATEGORICAL POPS EAST OF I-81 WITH
CHC FURTHER BACK TO THE WEST. MAINLY SHOWERS EXPECTED FOLLOWING
FROPA. REMAINDER OF LONG TERM WL FEATURE SHOWERS EACH PD COURTESY
OF UPR LVL LOW HANGING BACK TO THE WEST. AS IS TYPICAL IN THESE
CASES, EXPECT THAT AFT 12Z SATURDAY MOST OF THE SHOWERS WL BE OF
THE MORE HIT AND MISS VARIETY WITH MOSTLY MISSES. THUS, THRU THE
END OF THE LONG TERM WL KEEP 20-30 POPS OVR ENTIRE CWA.
TEMPS DRG THE PD EXPECTED TO BE BLO NRML UNDER EXTENSIVE CLD CVR.
FOLLOWED WPC GRIDS FOR THE LONG TERM WITH NO SIGNIFICANT
DISCREPANCIES BTWN MED RANGE GUIDANCE.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
18Z UPDATE...
TERMINALS WILL REMAIN VFR THROUGH THE LATE EVENING HOURS WITH
FEW-SCT CUMULUS CLOUDS UNDERLYING A HIGH CIRRUS LAYER. NO SHOWER
ACTIVITY EXPECTED NEXT 24 HOURS, THOUGH AN ISOLATED SHOWER MAY
POP UP AT ANY TIME. MARINE LAYER EXPECTED TO DEVELOP LATE TONIGHT
IN SOUTHEASTERLY LOW LEVEL FLOW WITH POTENTIAL FOR MVFR CIGS AT
AVP, BGM, ELM AND ITH AFTER 04Z. HIGHER ELEVATION TERMINALS OF ITH
AND BGM MAY SEE A BRIEF PERIOD OF IFR CIGS BETWEEN 09Z AND 13Z
THUS HAVE INCLUDED TEMPO FOR OVC009. MVFR MAY WORK UP INTO RME
TONIGHT BUT NOT CONFIDENT ENOUGH TO INCLUDE MENTION IN TAF SO HAVE
ONLY INCLUDED SCT025 FROM 03Z ONWARD. BY 15Z, EXPECT MARINE LAYER
TO BEGIN TO MIX OUT AT NY TERMINALS WITH AVP REMAINING BKN025
THROUGH END OF TAF VALID TIME.
WINDS WILL BE VRB THIS EVENING BECOMING SSE BETWEEN 5-10KTS AFTER
00Z.
OUTLOOK...
WED NGT/THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN SHOWERS AND
THUNDERSTORMS.
THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS
COLD FRONT STALLS NEAR AREA.
SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE
AFTERNOON.
SUN...MVFR RESTRICTIONS POSSIBLE IN ISOLATED SHOWERS BUT MAINLY
VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/TAC
NEAR TERM...MDP/TAC
SHORT TERM...MDP
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
145 PM EDT TUE MAY 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN OUR VICINITY TODAY THROUGH
WEDNESDAY. WHILE MUCH OF THE TIME WILL BE DRY, SCATTERED SHOWERS
AND PERHAPS A FEW THUNDERSTORMS WILL BE POSSIBLE. OUR PATTERN WILL
REMAIN UNSETTLED INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...
UPDATE TO CURRENT CONDITIONS. SHOWERS OVER THE WEST WILL MOVE
SLOWLY EAST AND SOUTH TO BE FROM AVP TO BGM MIDDAY BUT DISSIPATE BY
21Z. A FEW SHOWERS LATE IN THE NW. INTENSITY OF PRECIP DYING AND
LIGHTNING STRIKES NOT AS COMMON. MESO MODELS ESP HRRR HAVE A GOOD
HANDLE ON THIS AND FOLLOWED. MAX TEMPS IN THE EAST UPPED SLIGHTLY
DUE TO MORE SUN AND HARDLY ANY RAIN SHOWERS. WHERE IT IS RAINING
NOW MAX TEMPS WILL BE LATE BUT SHOULD STILL PEAK A80.
7 AM UPDATE...
FORECAST ADJUSTED TO FOR RADAR AND MODEL TRENDS. COMPLEX DEVELOPED
ON LEADING EDGE OF 850MB JET BUT IS NOW OUTRUNNING INTO MORE
STABLE AIR AS DOES SO. PRECIPITABLE WATER VALUES TO AROUND AN
INCH-AND-A-HALF MAY LEAD TO LOCALLY HEAVY RAINFALL IN CENTRAL TWIN
TIERS AND FINGER LAKES REGION LATER TODAY. COULD LEAD TO PONDING
IN POOR DRAINAGE AREAS.
PREVIOUS DISCUSSION...
AT 430 AM...COMPLEX OF STORMS DOVE THROUGH SOUTHWEST PA THE LAST
SEVERAL HOURS...AND THEN WEAKENED. HOWEVER...NEW CONVECTION HAS
FIRED AT LEADING EDGE OF 850MB JET...ALSO COINCIDING WITH A WEAK
WAVE ALOFT...EXTENDING FROM THE ONTARIO PENINSULA TO THE WESTERN
TIP OF NY AND SOME OF WESTERN PA. MEANWHILE...JUST A FEW SHOWERS
HAVE RESULTED FROM A WEAK VORTICITY MAXIMUM NOW TRAVERSING THE NY
THRUWAY CORRIDOR...WHICH IS RUNNING INTO PROGRESSIVELY MORE STABLE
AIR AND THUS NOT MUCH OF A PLAYER IN OUR WEATHER.
EARLIER RUNS OF THE WRF-ARW...NAM...GEM...AND NMM BROUGHT NOCTURNAL
CONVECTION WITH WAVE INTO THE TWIN TIERS YET INITIALIZED WITH THE
EARLIER SW PA COMPLEX TOTALLY MISSING. THUS I SIDED HRRR AND RUC13
SOLUTIONS WHICH HAD THE SW PA COMPLEX AND AS EXPECTED KEPT THINGS
PRETTY QUIET THROUGH MOST OF THE OVERNIGHT HOURS. THE NEW
CONVECTION NOW IN WESTERN NY/PA IS AT LEADING EDGE OF 850MB
JET...BUT MODELS SHOW THAT THE JET WILL WEAKEN CONSIDERABLY THE
NEXT FEW HOURS SO I ANTICIPATE THE ASSOCIATED CONVECTION TO
DIMINISH WHILE SKIMMING SOME OF OUR SW ZONES EARLY THIS MORNING.
HIGH PRESSURE IS CURRENTLY SLIDING OUT OF QUEBEC TO MAINE/CANADIAN
MARITIME PROVINCES...INITIATING COOL AIR DAMMING DOWN THE
APPALACHIANS. SOUTHEAST LOW LEVEL FLOW WILL DEVELOP
TODAY...SETTING UP A SURFACE CONVERGENCE ZONE IN VICINITY OF
FINGER LAKES TO CENTRAL SOUTHERN TIER OF NY. I THUS HAVE PLACED
HIGH CHANCE POPS IN CENTRAL SOUTHERN TIER TO FINGER LAKES FOR LATE
MORNING TO AFTERNOON TODAY. MODEL SOUNDINGS THERE SHOW SUFFICIENT
INSTABILITY FOR THUNDER TO ACCOMPANY THOSE SHOWERS...AND
PRECIPITABLE WATER VALUES OF NEARLY AN INCH-AND-A-HALF.
HOWEVER...THE FARTHER EAST THAT ACTIVITY MANAGES TO PROCEED...THE
DEEPER INTO THE MORE STABLE SOUTHEAST FLOW /VIA COOL AIR DAMMING
ALONG EAST COAST/ IT WILL GET. THUS LOWER CHANCES FOR SHOWERS AND
ONLY SLIGHT CHANCE OF THUNDER AT MOST. I DO NOT EVEN INCLUDE
THUNDER MENTION IN WESTERN CATSKILLS TO POCONOS.
NOT QUITE AS WARM AS MONDAY...DUE TO CLOUD COVERAGE IN WEST AND
MARINE INFLUENCED LOW LEVEL FLOW IN EAST...YET STILL 70S FOR MOST OF
THE AREA. SOME LOWER ELEVATIONS IN TWIN TIERS TO FINGER LAKES
COULD EVEN STILL MANAGE 80 DEGREES.
UPPER RIDGE PASSES OVER THE REGION TONIGHT. THERE WILL BE
MARGINAL ELEVATED INSTABILITY ALOFT IN THE WESTERN ZONES...BUT
LACK OF FORCING MECHANISMS OTHER THAN WEAK WAVES TRYING TO RIDE
THROUGH THE RIDGE HAS ME HESITANT TO GO ANY HIGHER THAN SLIGHT TO
LOW CHANCE POPS. LOWS TONIGHT IN THE 50S TO LOW 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
445 AM UPDATE...
MAIN ADJUSTMENT WAS TO FURTHER DELAY THE HIGHEST RAIN CHANCES
ASSOCIATED WITH INCOMING COLD-OCCLUDED FRONTAL ZONE. THERE WILL
STILL BE SHOWERS AROUND...PARTICULARLY WEDNESDAY AS NORTHERN STREAM
SURFACE FRONT EDGES INTO THE AREA BEFORE SHIFTING BACK NORTH.
THERE WILL ALSO BE MARGINAL INSTABILITY SUPPORTING MENTION OF
THUNDER IN CENTRAL TO NORTHERN ZONES. HOWEVER...MUCH OF THE TIME
OVERALL WILL BE DRY...ESPECIALLY THURSDAY. THE SLOWER TIMING OF
INCOMING SYSTEM ALSO FORCED A WARMER ADJUSTMENT FOR HIGH
TEMPERATURES THURSDAY TO MAINLY 75-80 DEGREE RANGE...THANKS TO
WARM SECTOR FIRMLY REASSERTING ITSELF WELL AHEAD OF THE COLD
FRONT. RAIN CHANCES THEN INCREASE THURSDAY NIGHT AS THAT COLD
FRONT APPROACHES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
350 AM UPDATE...
NO MAJOR CHANGES NEEDED THIS MORNING WITH ALL ATTENTION REMAINING
FOCUSED ON LATE WEEK RAIN EVENT. FCST MODELS NOW COMING INTO
BETTER AGREEMENT ON TIMING OF FROPA...WITH MOST SUGGESTING FEATURE
WILL PASS ACROSS THE REGION AFTER 12Z FRI. MAIN CONCERNS RIGHT NOW
APPEAR TO BE A POSSIBLE PERIOD OF HEAVY RAINFALL AS 850 U-WIND
SPEEDS OF 2-3 STANDARD DEVIATIONS ABOVE NORMAL PUMP AMPLE GULF OF
MEXICO AND WESTERN ATLANTIC MOISTURE NORTH TOWARDS OUR AREA. AS
IT STANDS RIGHT NOW...FEATURE LOOKS TO PASS QUICK ENOUGH TO
HOPEFULLY NEGATE ANY SIGNIFICANT HYDRO IMPACTS BUT LATER MODEL
RUNS WILL BE ABLE TO VERIFY THIS TREND. OVERALL CONVECTIVE
POTENTIAL LOOKS LIMITED AS THE HEAVIEST RAINS ARE EXPECTED IN A
POST FRONTAL (ANAFRONT-TYPE) AIRMASS WHERE INSTABILITY WILL BE LIMITED.
AFTER THIS FEATURE PASSES...EXPECT COOLER THAN NORMAL WEATHER INTO
THE UPCOMING WEEKEND AS SLOW MOVING UPPER LOW GRADUALLY ADVANCES
EAST INTO NEW ENGLAND AND NORTHERLY FLOW RETURNS TO THE AREA.
210 PM UPDATE...
EXTNDD PD STARTS OFF WITH H5 LOW BEGINNING TO CLOSE OFF IN THE WRN
GREAT LKS WITH FRONTAL BNDRY MEANDERING NR AREA THRU THE END OF THE
WEEK AND FIRST HALF OF THE WEEKEND. SVRL WVS OF LOPRES WL RIDE UP
ALONG BNDRY, WITH HEAVIEST RAIN LKLY THUR NGT AND FRI AHD OF CDFNT.
WITH BNDRY ON OUR DOORSTEP LATE THUR NGT/FRI MRNG EXPECT CHCS FOR
THUNDER AT ANY TIME TO START OFF THE LONG TERM. WL WORD IT AS CHC
TSTMS FOR THUR NGT WITH LKLY SHOWERS/THUNDER DRG THE DAY ON FRIDAY
WITH TIMING LKLY TO BE NAILED DOWN THE CLOSER WE GET TO THE END OF
THE WEEK. LATEST EURO IS FASTER THAN THE GFS/CMC ON PROGRESSION OF
FROPA WITH LATTER MODELS DELAYING ITS ARRIVAL UNTIL CLOSE TO 00Z SAT
WHILE EURO CLRS CWA BY 12Z FRIDAY.
UNSETTLED WX CONTS THRU THE EARLY PART OF THE WEEK AS ERN U.S. TROF
RMNS IN PLACE. LATEST GFS INDICATE H5 LOW CLOSING OFF AGAIN OVR THE
NORTHEAST U.S. ON MONDAY THUS WL KEEP CHC POPS IN AFT 12Z SATURDAY
WITH POTENTIAL COLD POOL ALOFT CAUSING INSTABILITY SHOWERS.
TEMPS THRU THE PD WL BE NR NORMAL TO SLIGHTLY BLO NORMAL UNDER
EXTENSIVE CLD CVR AND SHOWERY CONDS.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
18Z UPDATE...
TERMINALS WILL REMAIN VFR THROUGH THE LATE EVENING HOURS WITH
FEW-SCT CUMULUS CLOUDS UNDERLYING A HIGH CIRRUS LAYER. NO SHOWER
ACTIVITY EXPECTED NEXT 24 HOURS, THOUGH AN ISOLATED SHOWER MAY
POP UP AT ANY TIME. MARINE LAYER EXPECTED TO DEVELOP LATE TONIGHT
IN SOUTHEASTERLY LOW LEVEL FLOW WITH POTENTIAL FOR MVFR CIGS AT
AVP, BGM, ELM AND ITH AFTER 04Z. HIGHER ELEVATION TERMINALS OF ITH
AND BGM MAY SEE A BRIEF PERIOD OF IFR CIGS BETWEEN 09Z AND 13Z
THUS HAVE INCLUDED TEMPO FOR OVC009. MVFR MAY WORK UP INTO RME
TONIGHT BUT NOT CONFIDENT ENOUGH TO INCLUDE MENTION IN TAF SO HAVE
ONLY INCLUDED SCT025 FROM 03Z ONWARD. BY 15Z, EXPECT MARINE LAYER
TO BEGIN TO MIX OUT AT NY TERMINALS WITH AVP REMAINING BKN025
THROUGH END OF TAF VALID TIME.
WINDS WILL BE VRB THIS EVENING BECOMING SSE BETWEEN 5-10KTS AFTER
00Z.
OUTLOOK...
WED NGT/THUR...MAINLY VFR, BUT POSSIBLE MVFR PDS IN SHOWERS AND
THUNDERSTORMS.
THUR NGT/FRI...MVFR AND POSSIBLE IFR RESTRICTIONS IN SHRA/TSRA AS
COLD FRONT STALLS NEAR AREA.
SAT...MVFR RESTRICTIONS POSSIBLE EARLY, BECOMING VFR DURING THE
AFTERNOON.
SUN...MVFR RESTRICTIONS POSSIBLE IN ISOLATED SHOWERS BUT MAINLY
VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/TAC
NEAR TERM...MDP/TAC
SHORT TERM...MDP
LONG TERM...CMG
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1258 PM CDT TUE MAY 13 2014
.UPDATE...
ISSUED AT 1257 PM CDT TUE MAY 13 2014
HIGH PRESSURE CONTINUES TO SLOWLY BUILD OVER WESTERN AND CENTRAL
NORTH DAKOTA TODAY. MADE A FEW ADJUSTMENTS TO BUMP UP CLOUD COVER
IN THE EAST. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST.
UPDATE ISSUED AT 1021 AM CDT TUE MAY 13 2014
NO SIGNIFICANT UPDATES TO THE GOING FORECAST FOR THE MORNING
UPDATE. CLEAR SKIES SOUTHWEST TO PARTLY CLOUDY NORTHEAST.
NORTHWEST WINDS WILL PICK-UP AGAIN TODAY BUT LATEST 12 UTC NAM/
13 UTC RAP BUFKIT SOUNDINGS SUGGEST WE SHOULD REMAIN BELOW
ADVISORY CRITERIA. MADE SOME MINOR ADJUSTMENTS TO BUMP UP SKY
COVER EAST AND LOWER SKY COVER WEST.
UPDATE ISSUED AT 640 AM CDT TUE MAY 13 2014
AT 6 AM CDT..LARGE SURFACE LOW PRESSURE ACROSS THE GREAT LAKES AND
ITS WIDE CIRCULATION CONTINUES TO BRING SOME CLOUDS INTO THE NORTH
CENTRAL AND EAST. INCREASED THE CLOUD COVER ACROSS THE NORTH
CENTRAL AND EAST WITH THIS UPDATE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CDT TUE MAY 13 2014
MAIN FORECAST CONCERN TODAY IS WINDS...WITH ANOTHER BREEZY/WINDY DAY
- BUT WINDS NOT AS STRONG AS THOSE ON MONDAY. TONIGHT THE MAIN
CONCERN IS TEMPERATURES - WITH UPPER 20S TO MID 30S FORECAST.
CURRENTLY...SURFACE LOW PRESSURE WAS OVER NORTHERN
WISCONSIN...WITH HIGH PRESSURE DOMINATING THE FRONT RANGE FROM
NORTHERN ALBERTA/SASKATCHEWAN TO COLORADO.
PRESSURE GRADIENT AGAIN LEADS TO STRONG NORTHWEST WINDS ALOFT. AS
TEMPERATURES RISE AND THE SURFACE LAYER MIXES WITH LAYERS ABOVE THE
SURFACE...MIXING AND MOMENTUM TRANSFER WILL RESULT IN WINDS OF 20 TO
30 MPH BY AFTERNOON MOST AREAS. FORECAST BUFR SOUNDINGS ALSO
INDICATED CU AND/OR TCU FORMING IN THE LATE AFTERNOON. ADDED A
MENTION OF ISOLATED RAIN SHOWERS/SPRINKLES LATE AFTERNOON TO EARLY
EVENING.
ANOTHER SURGE OF COOL AIR FROM THE NORTH MOVES IN TONIGHT...AND
TEMPERATURES SHOULD RANGE FROM THE UPPER 20S TO AROUND 30 IN THE
NORTHWEST AND NORTH CENTRAL...TO THE LOW TO MID 30S SOUTHWEST AND
SOUTH CENTRAL.
WE WILL BEGIN OUR FROST/FREEZE STATEMENTS DURING THE TUESDAY DAY
SHIFT...BUT WILL MENTION THE ANTICIPATING TEMPERATURES IN THE
HAZARDOUS WEATHER OUTLOOK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 13 2014
MODELS ARE IN RELATIVE GOOD AGREEMENT WITH THE 00Z ECMWF/GFS/GFS
ENSEMBLE ALL LOOKING SIMILAR. THE HIGHLIGHTS IN THE EXTENDED INCLUDE
A CONTINUATION OF THE COOL PATTERN WEDNESDAY THROUGH FRIDAY (WITH
HIGHS 55 TO 60) DUE TO A LARGE AND PERSISTENT UPPER LOW OVER HUDSON
BAY INTO THE CENTRAL PLAINS. MODELS ARE DRY DURING THIS COOL PERIOD
AS NORTH DAKOTA ENDS UP ON THE WESTERN SIDE OF THIS COLD UPPER LOW
WITH LIMITED MOISTURE AND WEAK DYNAMICS. HOWEVER THIS WILL SLOWLY
CHANGE OVER THE WEEKEND AND INTO NEXT WEEK AS THIS COLD UPPER LOW
MOVES EAST TO THE GREAT LAKES REGION AND EASTERN PACIFIC ENERGY
BEGINS TO FLATTEN THE H500 RIDGE OVER THE WEST COAST AND NUDGE IT
INLAND. BY SUNDAY THE UPPER LOW IS OVER THE NORTHWEST US AND A
SHORTWAVE RIDGE IS OVER THE NORTHERN PLAINS. BY SUNDAY SHOULD SEE
HIGH TEMPS ON SUNDAY FINALLY APPROACHING 70 DEGREES ACROSS THE
WEST...AT LEAST INTO THE MID TO UPPER 60S. SHOULD SEE SIMILAR HIGH
TEMPERATURES MONDAY AND TUESDAY BUT WITH THE CLOSED UPPER LOW MOVING
TO MONTANA THE NORTHERN PLAINS WILL BE IN AN ACTIVE PRECIPITATION
PERIOD FOR SUNDAY THROUGH TUESDAY.
FOR THE EXTENDED PERIOD ONLY TARGET OF OPPORTUNITY TO DEPART FROM
THE ALLBLEND GUIDANCE WAS SATURDAY AND SATURDAY NIGHT AS WE TRIMMED
POPS BACK FEELING THE NEW 00Z GUIDANCE WAS A BIT SLOWER TO BRING A
CHANCE FOR SHOWERS INTO THE WEST AND CENTRAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1257 PM CDT TUE MAY 13 2014
STRONG NORTHWEST WINDS 15 TO 25 MPH WEST...TO 20 TO 30 MPH EAST
THROUGH THE AFTERNOON. WINDS WILL DIMINISH EARLY THIS EVENING AND
PICK UP AGAIN AROUND 16 UTC WEDNESDAY FROM THE NORTHWEST...BUT
WILL NOT BE AS STRONG. VFR CONDITIONS ARE EXPECTED ACROSS THE
FORECAST ROUTES. CONVECTIVE CUMULUS...MORE EXPANSIVE EAST WILL
LIFT AND FLATTEN THIS AFTERNOON...THEN DISSIPATE THIS EVENING.
EXPECT A SIMILAR SITUATION ON WEDNESDAY BUT THINK CEILINGS WILL BE
A LITTLE HIGHER...JUST ABOVE MVFR...WHEN THEY DEVELOP AROUND THE
END OF THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JV
LONG TERM...WAA
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
405 PM EDT TUE MAY 13 2014
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL KEEP THE REGION MILD AND RATHER
HUMID THROUGH AT LEAST THURSDAY. COOLER WEATHER IS IN STORE FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
JUST AS THE SHOWERS HAVE MOVED OUT OF MY NERN ZONES...A NEW STORM
HAS POPPED ON THE RIDGE OVER SWRN CENTRE COUNTY. SATELLITE SHOWS
THE CU FIELD GROWING OVER THE SWRN HALF OF MY FCST AREA...WHERE
THE RAP DEPICTS CAPES EXCEEDING 1000J ALONG WITH AN ERODING CAP.
HRRR SHOWS SCATTERED CONVECTION CONTINUING TO DEVELOP AS THE
AFTERNOON PROGRESSES. THE OVERALL COVERAGE CALLS FOR CHANCE POPS
AS THE PATTERN NOW RESEMBLES SOMETHING MORE COMMON IN JULY WITH
PULSE STORMS AND LITTLE CHANCE FOR ORGANIZATION.
THE REMAINDER OF THE AFTERNOON LOOKS UNSEASONABLY WARM AND HUMID.
MAXES WILL TOP OUT SURGE INTO THE LOWER TO MIDDLE 80S FOR MOST...
WITH FAIRLY UNCOMFORTABLE DEWPOINTS RISING TO THE LOWER TO MIDDLE
60S.
FOR TONIGHT...INDICATIONS ARE THAT THE BACK DOOR COLD FRONT COULD
ACTUALLY BE SHOVED BACK ALL THE WAY TO THE LAURELS...ALLOWING A
LOW LEVEL SERLY MARITIME FLOW TO COVER MUCH OF THE FORECAST AREA
BY MORNING. IT WILL REMAIN HUMID...SO SCATTERED SHOWERS/STORMS
CANNOT BE RULED OUT...BUT I WOULD EXPECT ACTIVITY TO DWINDLE WITH
THE LOSS OF HEATING THIS EVENING AND OVERNIGHT.
LOWS AVERAGING IN THE 60S ARE ACTUALLY WELL ABOVE NORMAL...SOME
15-20 DEG...FOR MID MAY.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
THE MARITIME FLOW WILL CAUSE WEDNESDAY TO START OFF ON THE CLOUDY
SIDE...WHICH SHOULD LEAD TO A SLIGHTLY COOLER DAY WITH MAX TEMPS
MAINLY IN THE 70S. THE BEST CHANCE FOR BREAKS IN THE CLOUDS WILL
BE IN THE AFTERNOON AND THERE WILL ONCE AGAIN BE A CHANCE OF
SHOWERS AND THUNDERSTORMS WITH THE CONTINUED ADVECTION OF MOISTURE
INTO THE REGION AHEAD OF THE DEEP MIDWESTERN TROUGH AND FRONTAL
SYSTEM.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
WELL AMPLIFIED AND SLOWLY PROGRESSIVE LONGWAVE RIDGE - TROF -
RIDGE PATTERN COVERING THE CONTINENTAL U.S. AT THE START OF THE
LONG TERM PERIOD IS FORECAST TO TRANSLATE INTO A TROF - RIDGE -
TROF PATTERN BY THE END OF THE PERIOD. OBVIOUSLY...THIS WILL
ENTAIL THE MAIN UPPER TROF NOW EMERGING INTO THE PLAINS STATES TO
MOVE INTO THE EASTERN U.S. DURING THE PERIOD...AS AS BEEN
ADVERTISED FOR AT LEAST SEVERAL DAYS IF NOT LONGER.
PRIOR TO THAT...THE AMPLIFIED SUBTROPICAL UPPER RIDGE NOW IN PLACE AND
ITS AFFECTS WILL DOMINATE THE REGION AT LEAST INTO EARLY THUR...WITH
SUMMER-LIKE TEMPERATURES...HUMIDITY AND ISOLATED TO SCATTERED
CONVECTION.
AS THE WELL ADVERTISED UPPER TROF AND ASSOCIATED COLD FRONT
ARRIVES...LATER THURSDAY THROUGH FRIDAY AT THIS POINT...RAIN
SHOWERS WILL BECOME MORE WIDESPREAD. THE FRONT IS EXPECTED PUSH
INTO A REGION OF PW OF 1.5 TO 2 INCHES AS THE FRONT BECOMES
ALIGNED WITH THE MID AND UPPER LEVEL FLOW...CONTINUING THE POTENTIAL
FOR A SIGNIFICANT RAINFALL EVEN SOMEWHERE ACROSS THE MID-
ATLANTIC STATES. ACCCORDINGLY CENTRAL PA IS IN THE NCEP/WPC
SLIGHT RISK AREA OF EXCESSIVE RAINFALL FOR THURSDAY INTO FRIDAY.
THE FRONT/UPPER SHOULD EXIT THE MID ATLC COAST SAT MORNING...HOWEVER
A SECONDARY PUSH/SHORT WAVE OF COOLER AIR MAY COME THROUGH LATER ON
SATURDAY HELPING TO INVIGORATING POST FRONTAL SHOWERS THROUGH THE
WEEKEND. DRIER BUT COOLER WEATHER WILL THEN PERSIST FOR THE
REMAINDER OF THE PERIOD...WITH TEMPERATURES SLOWLY MODERATING
FROM 5 TO 10 DEGREES BELOW NORMAL ON SATURDAY AND SUNDAY.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
TERMINALS ARE ALL VFR AS OF MID DAY...AND THAT TREND WILL CONTINUE
INTO THE EVENING WITH THE EXCEPTION OF THE AIRPORTS THAT GET HIT
BY THE POP-UP SHOWERS AND THUNDERSTORMS. THE CONVECTION WILL
CONTINUE TO BE SPOTTY FOR THE REMAINDER OF THE AFTERNOON...AND
WILL TEND TO FADE WITH THE LOSS OF HEATING LATER TODAY AND THIS
EVENING.
MODELS CONTINUE TO SHOW MARITIME AIR PUSHING WESTWARD ACROSS THE
AIRSPACE TONIGHT IN ASSOCIATION WITH A BACK DOOR COLD FRONT. THIS
SHOULD RESULT IN MVFR/IFR CEILINGS AND AREAS OF PATCHY
FOG...ESPECIALLY OVER CENTRAL AND EASTERN TERMINALS. IT`S STILL
NOT CLEAR HOW FAR WEST AND NORTH THE LOW CLOUDS WILL MANAGE TO
INVADE...BUT CONFIDENCE WAS HIGH ENOUGH IN THE GUIDANCE TO
INCLUDE DETERIORATING CONDITIONS IN ALL THE TAFS.
ANTICIPATE SLOW IMPROVEMENT BY WED AFTERNOON WITH MORE SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING INVOF FRONTAL CONVERGENCE
ZONE OVER WESTERN/CENTRAL PA.
.OUTLOOK...
THU...VFR-MVFR WITH ISOLD-SCT SHWRS/TSTMS.
FRI...MVFR-IFR LKLY WITH N-S BAND OF LOCALLY HEAVY RAIN AND
ASSOCIATED WITH A SLOW MOVING COLD FRONT.
SAT...VFR-MVFR CIGS WITH SCT SHOWERS MAINLY WEST.
SUN...MAINLY VFR BUT WITH SCATTERED AFTERNOON SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
139 PM EDT TUE MAY 13 2014
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL KEEP THE REGION MILD AND RATHER
HUMID THROUGH AT LEAST THURSDAY. COOLER WEATHER IS IN STORE FOR
THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
JUST AS THE SHOWERS HAVE MOVED OUT OF MY NERN ZONES...A NEW STORM
HAS POPPED ON THE RIDGE OVER SWRN CENTRE COUNTY. SATELLITE SHOWS
THE CU FIELD GROWING OVER THE SWRN HALF OF MY FCST AREA...WHERE
THE RAP DEPICTS CAPES EXCEEDING 1000J ALONG WITH AN ERODING CAP.
HRRR SHOWS SCATTERED CONVECTION CONTINUING TO DEVELOP AS THE
AFTERNOON PROGRESSES. THE OVERALL COVERAGE CALLS FOR CHANCE POPS
AS THE PATTERN NOW RESEMBLES SOMETHING MORE COMMON IN JULY WITH
PULSE STORMS AND LITTLE CHANCE FOR ORGANIZATION.
THE REMAINDER OF THE AFTERNOON LOOKS UNSEASONABLY WARM AND HUMID.
MAXES WILL TOP OUT SURGE INTO THE LOWER TO MIDDLE 80S FOR MOST...
WITH FAIRLY UNCOMFORTABLE DEWPOINTS RISING TO THE LOWER TO MIDDLE
60S.
FOR TONIGHT...INDICATIONS ARE THAT THE BACK DOOR COLD FRONT COULD
ACTUALLY BE SHOVED BACK ALL THE WAY TO THE LAURELS...ALLOWING A
LOW LEVEL SERLY MARITIME FLOW TO COVER MUCH OF THE FORECAST AREA
BY MORNING. IT WILL REMAIN HUMID...SO SCATTERED SHOWERS/STORMS
CANNOT BE RULED OUT...BUT I WOULD EXPECT ACTIVITY TO DWINDLE WITH
THE LOSS OF HEATING THIS EVENING AND OVERNIGHT.
LOWS AVERAGING IN THE 60S ARE ACTUALLY WELL ABOVE NORMAL...SOME
15-20 DEG...FOR MID MAY.
&&
.SHORT TERM /WEDNESDAY/...
THE MARITIME FLOW WILL CAUSE WEDNESDAY TO START OFF ON THE CLOUDY
SIDE...WHICH SHOULD LEAD TO A SLIGHTLY COOLER DAY WITH MAX TEMPS
MAINLY IN THE 70S. THE BEST CHANCE FOR BREAKS IN THE CLOUDS WILL
BE IN THE AFTERNOON AND THERE WILL ONCE AGAIN BE A CHANCE OF
SHOWERS AND THUNDERSTORMS WITH THE CONTINUED ADVECTION OF MOISTURE
INTO THE REGION AHEAD OF THE DEEP MIDWESTERN TROUGH AND FRONTAL
SYSTEM.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
PRONOUNCED SUBTROPICAL UPPER RIDGE WILL DOMINATE THE EAST COAST
EARLY IN THE PERIOD NEAR TO ABOVE NORMAL SEASONAL TEMPS. HOW WARM
IT GETS HOWEVER WILL BE DEPENDENT ON AMOUNT OF CLOUDINESS/PCPN
FROM CONVECTION THAT MOVES EAST EACH MORNING FROM THE OHIO
VALLEY/MIDWEST.
MEANWHILE...AS HAS BEEN ADVERTISED FOR SEVERAL DAYS...A LONG WAVE
UPPER LEVEL TROF NOW DIGGING/AMPLIFYING OVER THE ROCKY MOUNTAINS
IS PREDICTED TO MOVE SLOWLY EAST THROUGH THE WEEK. THIS WILL PUSH
A COLD FRONT TOWARD PA INCREASING PCPN PROBS EACH DAY FROM WED
THROUGH FRIDAY.
AS THE UPPER TROF AND ASSOCIATED COLD FRONT ARRIVES...WED INTO AT
LEAST FRIDAY CONTINUE TO LOOK UNSETTLED...WITH PLENTY OF CLOUDS
AND A HIGH CHC OF SHRA/TSRA AS THE SLOW-MOVING FRONT CROSSES THE
REGION. WITH THE SLOW MOVING SFC FRONT ALIGNED WITH THE POTENT
UPPER LEVEL TROF...THE POTENTIAL EXISTS FOR A SIGNIFICANT RAINFALL
EVENT TO DEVELOP SOMEWHERE ACROSS THE MID-ATLANTIC STATES DURING
THE MIDDLE TO END OF THIS WEEK.
OVERALL...MODEL GUIDANCE IS CONSISTENT WITH THE PROGRESSION OF
THE UPPER TROF MOVING INTO THE EASTERN U.S. EVOLUTION OF THE SFC
FRONT AND HVY PCPN PATTERN IS A BIT DIFFERENT TODAY...NOT
SURPRISINGLY WITH MORE OF THE HEAVIEST PCPN BEING SHUNTED S OF
PA.
THE SFC FRONT LOOKS TO PUSH EAST OF THE REGION EARLY NEXT
WEEKEND...BUT MUCH COOLER TEMPS AND POSSIBLE SHOWERS LOOK LIKE
THEY/LL LINGER...ESPECIALLY ACROSS THE NRN AND WESTERN MTNS.
DRIER BUT STILL COOLER THAN AVERAGE WEATHER WILL RETURN INTO THE
BEGINNING OF NEXT WEEK AS NORTHERN STREAM HIGH PRESSURE MOVES
ACROSS THE REGION.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
TERMINALS ARE ALL VFR AS OF MID DAY...AND THAT TREND WILL CONTINUE
INTO THE EVENING WITH THE EXCEPTION OF THE AIRPORTS THAT GET HIT
BY THE POP-UP SHOWERS AND THUNDERSTORMS. THE CONVECTION WILL
CONTINUE TO BE SPOTTY FOR THE REMAINDER OF THE AFTERNOON...AND
WILL TEND TO FADE WITH THE LOSS OF HEATING LATER TODAY AND THIS
EVENING.
MODELS CONTINUE TO SHOW MARITIME AIR PUSHING WESTWARD ACROSS THE
AIRSPACE TONIGHT IN ASSOCIATION WITH A BACK DOOR COLD FRONT. THIS
SHOULD RESULT IN MVFR/IFR CEILINGS AND AREAS OF PATCHY
FOG...ESPECIALLY OVER CENTRAL AND EASTERN TERMINALS. IT`S STILL
NOT CLEAR HOW FAR WEST AND NORTH THE LOW CLOUDS WILL MANAGE TO
INVADE...BUT CONFIDENCE WAS HIGH ENOUGH IN THE GUIDANCE TO
INCLUDE DETERIORATING CONDITIONS IN ALL THE TAFS.
ANTICIPATE SLOW IMPROVEMENT BY WED AFTERNOON WITH MORE SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING INVOF FRONTAL CONVERGENCE
ZONE OVER WESTERN/CENTRAL PA.
.OUTLOOK...
THU...VFR-MVFR WITH ISOLD-SCT SHWRS/TSTMS.
FRI...MVFR-IFR LKLY WITH N-S BAND OF LOCALLY HEAVY RAIN AND
ASSOCIATED WITH A SLOW MOVING COLD FRONT.
SAT...VFR-MVFR CIGS WITH SCT SHOWERS MAINLY WEST.
SUN...MAINLY VFR BUT WITH SCATTERED AFTERNOON SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
426 PM EDT TUE MAY 13 2014
.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH MID WEEK...BEFORE A COLD FRONT
CROSSES FROM THE WEST ON THURSDAY. A COOLER AND DRIER AIR MASS WILL
SETTLE ACROSS THE REGION FRIDAY AND SLOWLY MODIFY WARMER THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 425 PM...SCT CONVECTION REMAINS LIMITED TO THE TN BORDER AREA
WITH ISOLATED CONVECTION SOUTH TO THE NC/SC BORDER. THINK THIS TREND
WILL CONTINUE INTO THE EVENING BEFORE DISSIPATING OVERNIGHT. HAVE
UPDATED FOR THESE TRENDS AND FOR OTHER CURRENT CONDITIONS.
AS OF 200 PM EDT TUESDAY...THE LATEST RUNS OF THE HRRR AND OUR LOCAL
WORKSTATION WRF DRIFT MOST OF THE SHOWER AND TSTM ACTIVITY OVER THE
NC MTNS INTO ERN TN OVER THE NEXT FEW HOURS. ISOLATED SHOWERS AND A
FEW TSTMS ARE ALSO EXPECTED FOR A WHILE LONGER OVER THE NC FOOTHILLS
WHERE THERE IS LIGHT UPSLOPE FLOW AND SIGNS OF TOWERING CU ON THE
VSBL SATELLITE IMAGERY. ELSEWHERE THE LATE AFTN AND EVENING HOURS
SHOULD BE LARGELY DRY. OVERNIGHT...AREAS OF VALLEY FOG ARE AGAIN
EXPECTED TO DEVELOP OVER THE SOUTHWEST AND CENTRAL NC MTNS.
LATE IN THE DAY ON WEDNESDAY THERE ARE SIGNS THAT SHOWER AND
THUNDERSTORM ACTIVITY WILL BEGIN TO PICK UP OVER THE REGION...
ESPECIALLY OVER THE MOUNTAINS AND THE FOOTHILLS. HOWEVER...THIS IS
NOT EXPECTED TO HAPPEN UNTIL THE EARLY EVENING HOURS. UPSLOPE FLOW
SHOULD RESULT IN A LITTLE MORE CLOUD COVER ALONG THE SOUTHERN
ESCARPMENT OF THE APPALACHIANS AND MAX TEMPS HAVE BEEN ADJUSTED DOWN
A FEW DEGREES IN THOSE AREAS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF MIDDAY TUESDAY...WRN ATLANTIC HIGH PRESSURE WILL BEGIN TO
DISLODGE WED NIGHT AS DEEP LONGWAVE TROUGH DIGS INTO THE MISSISSIPPI
VALLEY. UNDER THE INFLUENCE OF A SHORTWAVE EMBEDDED IN THE TROUGH...A
SFC LOW WILL DEVELOP ALONG THE STALLED COLD FRONT EXTENDING FROM THE
WRN GULF NEWD INTO THE ERN GREAT LAKES. THE LOW WILL LIFT THRU THE
OHIO VALLEY THURSDAY AND THE COLD FRONT WILL PUSH EWD INTO OUR AREA
AT THIS TIME. STRONG MOISTURE ADVECTION THROUGH A DEEP LAYER AHEAD OF
THE FRONT WILL BRING A HEAVY RAIN THREAT TO THE CWFA AS EARLY AS THU
MRNG. A SECONDARY THREAT MAY BE POSED BY SEVERE WX BUT THE HEAVY RAIN
IS OF GREATER CONCERN AT THIS TIME.
NEARLY DUE SOUTHERLY LLJ WILL QUICKLY GET UNDERWAY WED EVENING AS THE
GRADIENT TIGHTENS AHEAD OF THE DEVELOPING FRONTAL WAVE. GFS AND NAM
BOTH DEPICT PWAT VALUES SURGING ABOVE 1.5 INCHES BY 06Z THU.
ENHANCEMENT ALONG THE BLUE RIDGE IS TO BE EXPECTED AND IS REFLECTED
IN QPF GUIDANCE FROM THE MAJOR MODELS. A FAIR NUMBER OF SREF AND GEFS
MEMBERS PRODUCE QPF OF OVER 1 INCH IN 6 HOURS WHICH IS IN LINE WITH
THE UPPER END OF THE OPNL GUIDANCE RANGE AND WPC. THE EVENT LOOKS TO
BE TWO-PRONGED...AFFECTING THE BLUE RIDGE AREAS EARLIER ON AS THE LLJ
INTERCEPTS THE RIDGE...AND LATER AS THE BEST MOISTURE ADVECTION
OCCURS OVER THE NW PIEDMONT AND CHARLOTTE METRO. THE LATTER BECOMES
AN ISSUE LATE THU AFTN OR EVENING. THE GFS AND NAM BOTH PRODUCE A
FRONTAL WAVE AT THIS TIME MOVING NWD FROM THE GA COAST. THIS ENHANCES
MOISTURE TRANSPORT FROM THE ATLANTIC AND ALSO SLOWS THE EWD MOVEMENT
OF THE FRONT. A FLOOD WATCH IS LIKELY TO BE NEEDED ONCE BOTH WAVES OF
HEAVIER PRECIP COME WITHIN THE USUAL WINDOW FOR ISSUANCE.
SOUNDINGS ARE DEEPLY SATURATED AND LAPSE RATES ACCORDINGLY MARGINAL
DURING THE BULK OF THE EVENT. OVERALL INSTABILITY IS LOW BUT SHEAR
BECOMES QUITE STRONG LATE WED NIGHT. EXCEPT IN THE SW MTNS WHERE THE
FRONT PUSHES IN EARLY ON...OVERLAP OF THESE PARAMETERS CONTINUES THRU
THE DAY THU ACRS THE AREA SO CONVECTIVE CELLS WILL NEED TO BE
MONITORED CLOSELY.
THAT SECONDARY FRONTAL WAVE WILL MOVE NORTH OF THE AREA AS THE UPPER
TROUGH SWINGS IN FRIDAY...GRADUALLY BRINGING THE PIEDMONT PRECIP TO
AN END DURING THE MORNING. AFTER A MORE SETTLED PERIOD...SOME DIURNAL
CONVECTION MAY KICK OFF LATE IN THE DAY OVER THE HIGH TERRAIN...AND
GARDEN VARIETY SHOWERS COULD RETURN MAINLY IN THE NRN MTNS. MAX TEMPS
FOLLOWING THE FROPA WILL BE NOTICEABLY COOLER...A FEW DEGREES BELOW
CLIMO.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AT 200 PM EDT TUESDAY...A LARGE ULVL LOW WILL PERSIST ACROSS THE ERN
CONUS TO BEGIN THE EXT RANGE AND SLOWLY LIFT AND PUSH EAST THROUGH
THE PERIOD. THERE IS GOOD AGREEMENT IN THE OP MODELS WITH THIS
SCENARIO WITH LITTLE OUTLYING DEVIATIONS ON THE SYNOPTIC SCALE. SOME
SIGFNT DIFFERENCES SHOW UP IN AVAILABLE LLVL MOISTURE SAT/SUN AND
THIS IS ALREADY ACCOUNTED FOR WELL WITH THE LOW END CHANCE POPS.
THE ATMOS WILL BE SLOW TO MODIFY AT THE SFC WITH A FAIRLY STRONG
THETA/E TROF ACCOMPANYING A CP HIPRES CENTER ACROSS THE GLAKES. THIS
WILL HOLD TD/S WELL BELOW NORMAL OVER THE WEEKEND AND ALLOW NON/MTN
LCL/S TO AROUND 8 KFT. THERE WILL BE SEVERAL UPPER ENERGY POCKETS
CROSSING THROUGH THE PERIOD...WITH SAT INTO MID DAY SUN HAVING THE
BEST CHANCE FOR A FORCED PRECIP ENHANCEMENT. STILL DON/T SEE ENOUGH
DEEP CONVECTIVE POTENTIAL TO INCLUDE TSTMS IN THE FCST AS LFC/S
REMAIN TOO COOL AND A MLVL WARM LAYER PERSISTS. WILL MAINTAIN THE
SLIGHT CHANCE POPS EARLY SAT AND INCREASE TO LOW END CHANCES SAT
NIGHT AND SUN ACROSS THE MTNS.
DEEPER SUBSIDENCE BUILDS IN SUN NIGHT AS THE UPPER LOW SHIFTS EAST
AND THE CHANCES FOR PRECIP WILL ACCORDINGLY GO TO NON/MENTIONABLE
MON AND TUE WITH LOWERING COLUMN MOISTURE. OVERALL...IT LOOKS LIKE A
VERY PLEASANT PERIOD WITH MAX TEMPS A FEW DEGREES BELOW
NORMAL...PERHAPS A DEGREE OR TWO COOLER ON SUN WITH INCREASING MLVL
CLOUDINESS. THEN A GENERAL WARM UP TO NORMAL AND ABOVE MON/TUE WITH
TD/S HELD RELATIVELY LOW.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
AT KCLT...THE BERMUDA HIGH WILL HOLD ON FOR ONE MORE DAY BRINGING
SOUTHERLY WINDS THROUGH THE PERIOD. A SCT CU DECK UP AROUND 5000
FEET WILL DISSIPATE AROUND SUNSET. A FEW SHRA MAY YET DEVELOP AND
I/VE KEPT A VCSH GROUP FOR A FEW HOURS DURING MAX HEATING TDA. NOT
EXPECTING ANY FOG OR STRATUS TONIGHT. LATER WEDNESDAY AFTERNOON A
LITTLE BETTER COVERAGE OF SHOWERS MAY DEVELOP...BUT THIS WILL BE
WELL AFTER THE VALID PERIOD OF THE TAFS.
ELSEHWERE...MOST OF THE MODELS AGREE THAT THE SHOWERS AND
THUNDERSTORMS DEVELOPING OVER THE NC MTNS WILL CONTINUE TO DRIFT TO
THE NORTH AND AWAY FROM KAVL. I DID KEEP VCSH IN THE TAF...BUT HAVE
REMOVED ANY THUNDER. OVERNIGHT VALLEY FOG SHOULD DEVELOP ONCE AGAIN
IN THE FRENCH BROAD VALLEY...THOUGH WITH BNDRY LAYER DEWPOINTS
EXPECTED TO FALL A LITTLE OVERNIGHT I DIDN/T GO ANY LOWER THAN THE
PREVIOUS SHIFT/S 2SM. VFR AT THE REMAINING SITES THROUGH 18 UTC WED.
OUTLOOK...WEDNESDAY SHOULD BE LARGELY DRY. ON THURSDAY A SLOW MOVING
COLD FRONT WILL YIELD A BETTER CHANCE OF RESTRICTIONS IN PROLONGED
PRECIPITATION AND THUNDERSTORMS. EXPECT VFR AGAIN FRIDAY.
CONFIDENCE TABLE...
20-02Z 02-08Z 08-14Z 14-20Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 92% HIGH 86%
KAVL HIGH 100% MED 74% LOW 49% HIGH 94%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 92% HIGH 86%
KAND HIGH 100% HIGH 100% HIGH 87% HIGH 89%
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...MCAVOY/RWH
SHORT TERM...WIMBERLEY
LONG TERM...SBK
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
255 PM EDT TUE MAY 13 2014
.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH MID WEEK...BEFORE A COLD FRONT
CROSSES FROM THE WEST ON THURSDAY. A COOLER AND DRIER AIR MASS WILL
SETTLE ACROSS THE REGION FRIDAY AND SLOWLY MODIFY WARMER THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 200 PM EDT TUESDAY...THE LATEST RUNS OF THE HRRR AND OUR LOCAL
WORKSTATION WRF DRIFT MOST OF THE SHOWER AND TSTM ACTIVITY OVER THE
NC MTNS INTO ERN TN OVER THE NEXT FEW HOURS. ISOLATED SHOWERS AND A
FEW TSTMS ARE ALSO EXPECTED FOR A WHILE LONGER OVER THE NC FOOTHILLS
WHERE THERE IS LIGHT UPSLOPE FLOW AND SIGNS OF TOWERING CU ON THE
VSBL SATELLITE IMAGERY. ELSEWHERE THE LATE AFTN AND EVENING HOURS
SHOULD BE LARGELY DRY. OVERNIGHT...AREAS OF VALLEY FOG ARE AGAIN
EXPECTED TO DEVELOP OVER THE SOUTHWEST AND CENTRAL NC MTNS.
LATE IN THE DAY ON WEDNESDAY THERE ARE SIGNS THAT SHOWER AND
THUNDERSTORM ACTIVITY WILL BEGIN TO PICK UP OVER THE
REGION...ESPECIALLY OVER THE MOUNTAINS AND THE FOOTHILLS.
HOWEVER...THIS IS NOT EXPECTED TO HAPPEN UNTIL THE EARLY EVENING
HOURS. UPSLOPE FLOW SHOULD RESULT IN A LITTLE MORE CLOUD COVER ALONG
THE SOUTHERN ESCARPMENT OF THE APPALACHIANS AND MAX TEMPS HAVE BEEN
ADJUSTED DOWN A FEW DEGREES IN THOSE AREAS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF MIDDAY TUESDAY...WRN ATLANTIC HIGH PRESSURE WILL BEGIN TO
DISLODGE WED NIGHT AS DEEP LONGWAVE TROUGH DIGS INTO THE MISSISSIPPI
VALLEY. UNDER THE INFLUENCE OF A SHORTWAVE EMBEDDED IN THE TROUGH...A
SFC LOW WILL DEVELOP ALONG THE STALLED COLD FRONT EXTENDING FROM THE
WRN GULF NEWD INTO THE ERN GREAT LAKES. THE LOW WILL LIFT THRU THE
OHIO VALLEY THURSDAY AND THE COLD FRONT WILL PUSH EWD INTO OUR AREA
AT THIS TIME. STRONG MOISTURE ADVECTION THROUGH A DEEP LAYER AHEAD OF
THE FRONT WILL BRING A HEAVY RAIN THREAT TO THE CWFA AS EARLY AS THU
MRNG. A SECONDARY THREAT MAY BE POSED BY SEVERE WX BUT THE HEAVY RAIN
IS OF GREATER CONCERN AT THIS TIME.
NEARLY DUE SOUTHERLY LLJ WILL QUICKLY GET UNDERWAY WED EVENING AS THE
GRADIENT TIGHTENS AHEAD OF THE DEVELOPING FRONTAL WAVE. GFS AND NAM
BOTH DEPICT PWAT VALUES SURGING ABOVE 1.5 INCHES BY 06Z THU.
ENHANCEMENT ALONG THE BLUE RIDGE IS TO BE EXPECTED AND IS REFLECTED
IN QPF GUIDANCE FROM THE MAJOR MODELS. A FAIR NUMBER OF SREF AND GEFS
MEMBERS PRODUCE QPF OF OVER 1 INCH IN 6 HOURS WHICH IS IN LINE WITH
THE UPPER END OF THE OPNL GUIDANCE RANGE AND WPC. THE EVENT LOOKS TO
BE TWO-PRONGED...AFFECTING THE BLUE RIDGE AREAS EARLIER ON AS THE LLJ
INTERCEPTS THE RIDGE...AND LATER AS THE BEST MOISTURE ADVECTION
OCCURS OVER THE NW PIEDMONT AND CHARLOTTE METRO. THE LATTER BECOMES
AN ISSUE LATE THU AFTN OR EVENING. THE GFS AND NAM BOTH PRODUCE A
FRONTAL WAVE AT THIS TIME MOVING NWD FROM THE GA COAST. THIS ENHANCES
MOISTURE TRANSPORT FROM THE ATLANTIC AND ALSO SLOWS THE EWD MOVEMENT
OF THE FRONT. A FLOOD WATCH IS LIKELY TO BE NEEDED ONCE BOTH WAVES OF
HEAVIER PRECIP COME WITHIN THE USUAL WINDOW FOR ISSUANCE.
SOUNDINGS ARE DEEPLY SATURATED AND LAPSE RATES ACCORDINGLY MARGINAL
DURING THE BULK OF THE EVENT. OVERALL INSTABILITY IS LOW BUT SHEAR
BECOMES QUITE STRONG LATE WED NIGHT. EXCEPT IN THE SW MTNS WHERE THE
FRONT PUSHES IN EARLY ON...OVERLAP OF THESE PARAMETERS CONTINUES THRU
THE DAY THU ACRS THE AREA SO CONVECTIVE CELLS WILL NEED TO BE
MONITORED CLOSELY.
THAT SECONDARY FRONTAL WAVE WILL MOVE NORTH OF THE AREA AS THE UPPER
TROUGH SWINGS IN FRIDAY...GRADUALLY BRINGING THE PIEDMONT PRECIP TO
AN END DURING THE MORNING. AFTER A MORE SETTLED PERIOD...SOME DIURNAL
CONVECTION MAY KICK OFF LATE IN THE DAY OVER THE HIGH TERRAIN...AND
GARDEN VARIETY SHOWERS COULD RETURN MAINLY IN THE NRN MTNS. MAX TEMPS
FOLLOWING THE FROPA WILL BE NOTICEABLY COOLER...A FEW DEGREES BELOW
CLIMO.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AT 200 PM EDT TUESDAY...A LARGE ULVL LOW WILL PERSIST ACROSS THE ERN
CONUS TO BEGIN THE EXT RANGE AND SLOWLY LIFT AND PUSH EAST THROUGH
THE PERIOD. THERE IS GOOD AGREEMENT IN THE OP MODELS WITH THIS
SCENARIO WITH LITTLE OUTLYING DEVIATIONS ON THE SYNOPTIC SCALE. SOME
SIGFNT DIFFERENCES SHOW UP IN AVAILABLE LLVL MOISTURE SAT/SUN AND
THIS IS ALREADY ACCOUNTED FOR WELL WITH THE LOW END CHANCE POPS.
THE ATMOS WILL BE SLOW TO MODIFY AT THE SFC WITH A FAIRLY STRONG
THETA/E TROF ACCOMPANYING A CP HIPRES CENTER ACROSS THE GLAKES. THIS
WILL HOLD TD/S WELL BELOW NORMAL OVER THE WEEKEND AND ALLOW NON/MTN
LCL/S TO AROUND 8 KFT. THERE WILL BE SEVERAL UPPER ENERGY POCKETS
CROSSING THROUGH THE PERIOD...WITH SAT INTO MID DAY SUN HAVING THE
BEST CHANCE FOR A FORCED PRECIP ENHANCEMENT. STILL DON/T SEE ENOUGH
DEEP CONVECTIVE POTENTIAL TO INCLUDE TSTMS IN THE FCST AS LFC/S
REMAIN TOO COOL AND A MLVL WARM LAYER PERSISTS. WILL MAINTAIN THE
SLIGHT CHANCE POPS EARLY SAT AND INCREASE TO LOW END CHANCES SAT
NIGHT AND SUN ACROSS THE MTNS.
DEEPER SUBSIDENCE BUILDS IN SUN NIGHT AS THE UPPER LOW SHIFTS EAST
AND THE CHANCES FOR PRECIP WILL ACCORDINGLY GO TO NON/MENTIONABLE
MON AND TUE WITH LOWERING COLUMN MOISTURE. OVERALL...IT LOOKS LIKE A
VERY PLEASANT PERIOD WITH MAX TEMPS A FEW DEGREES BELOW
NORMAL...PERHAPS A DEGREE OR TWO COOLER ON SUN WITH INCREASING MLVL
CLOUDINESS. THEN A GENERAL WARM UP TO NORMAL AND ABOVE MON/TUE WITH
TD/S HELD RELATIVELY LOW.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AT KCLT...THE BERMUDA HIGH WILL HOLD ON FOR ONE MORE DAY BRINGING
SOUTHERLY WINDS THROUGH THE PERIOD. A SCT CU DECK UP AROUND 5000
FEET WILL DISSIPATE AROUND SUNSET. A FEW SHRA MAY YET DEVELOP AND
I/VE KEPT A VCSH GROUP FOR A FEW HOURS DURING MAX HEATING TDA. NOT
EXPECTING ANY FOG OR STRATUS TONIGHT. LATER WEDNESDAY AFTERNOON A
LITTLE BETTER COVERAGE OF SHOWERS MAY DEVELOP...BUT THIS WILL BE
WELL AFTER THE VALID PERIOD OF THE TAFS.
ELSEHWERE...MOST OF THE MODELS AGREE THAT THE SHOWERS AND
THUNDERSTORMS DEVELOPING OVER THE NC MTNS WILL CONTINUE TO DRIFT TO
THE NORTH AND AWAY FROM KAVL. I DID KEEP VCSH IN THE TAF...BUT HAVE
REMOVED ANY THUNDER. OVERNIGHT VALLEY FOG SHOULD DEVELOP ONCE AGAIN
IN THE FRENCH BROAD VALLEY...THOUGH WITH BNDRY LAYER DEWPOINTS
EXPECTED TO FALL A LITTLE OVERNIGHT I DIDN/T GO ANY LOWER THAN THE
PREVIOUS SHIFT/S 2SM. VFR AT THE REMAINING SITES THROUGH 18 UTC WED.
OUTLOOK...WEDNESDAY SHOULD BE LARGELY DRY. ON THURSDAY A SLOW MOVING
COLD FRONT WILL YIELD A BETTER CHANCE OF RESTRICTIONS IN PROLONGED
PRECIPITATION AND THUNDERSTORMS. EXPECT VFR AGAIN FRIDAY.
CONFIDENCE TABLE...
19-01Z 01-07Z 07-13Z 13-19Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 81%
KAVL HIGH 100% HIGH 83% LOW 56% HIGH 95%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 81%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 85%
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...MCAVOY
SHORT TERM...WIMBERLEY
LONG TERM...SBK
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
133 PM EDT TUE MAY 13 2014
.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH MID WEEK...BEFORE A COLD FRONT
CROSSES FROM THE WEST ON THURSDAY. A COOLER AND DRIER AIR MASS WILL
SETTLE ACROSS THE REGION FRIDAY AND SLOWLY MODIFY WARMER THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1125 AM EDT TUESDAY...SHOWERS ARE BEGINNING TO DEVELOP OVER
THE NC MTNS...WHICH IS RIGHT IN LINE WITH THE EXPECTED TIMING. THE
LATEST RUC BRINGS A WEAK H5 SHORT WAVE ACROSS THE NC MTNS DURING THE
COURSE OF THE AFTERNOON HOURS WHICH MAY HELP TO ORGANIZE CONVECTION
JUST A LITTLE.
AS OF 905 AM EDT TUESDAY...A BAND OF ELEVATED TCU IS WORKING SLOWLY
TO THE NORTH ACROSS THE SOUTHWEST PART OF THE FORECAST AREA. BASED
ON THE CAPPING INVERSION ON THE GSO SOUNDING AND THE RATHER WARM
LLVLS ON THE FFC SOUNDING...I DON/T SEE THESE TOWERS AMOUNTING TO
MUCH AS WE WILL HAVE TO WAIT UNTIL THE EARLY AFTN HOURS FOR SURFACE
BASED CONVECTION TO INITIATE OVER THE MOUNTAINS. THE CURRENT POP
GRIDS ARE DOING A GOOD JOB WITH THIS AND ONLY MINOR TWEAKS WERE
NEEDED.
AS OF DAYBREAK...PATCHY DENSE FOG IN THE NC MOUNTAIN VALLEYS...BUT
OTHERWISE FAIR. THE FOG SHOULD BURN OFF QUICKLY ONCE THE SUN STARTS
TO WARM UP THE BOUNDARY LAYER AROUND 13Z.
OVER THE NEXT 24 HOURS...PERSISTENCE IS THE WORD TO DESCRIBE OUR
EXPECTED WEATHER. THE UPPER RIDGE WILL CONTINUE TO BUILD AND SHIFT
SLOWLY EAST ALONG THE EAST COAST AS EXPECTED...WHICH WILL MAINTAIN
THE BERMUDA HIGH AT THE SURFACE...POKING WESTWARD OVER THE
CAROLINAS. THAT MEANS PRECIP CHANCES THAT FOLLOW CLIMATOLOGY...AND
SEASONALLY WARM TEMPERATURES. ONCE AGAIN...THE AMOUNT OF BUOYANCY
SEEN IN NAM FCST SOUNDINGS LOOKS WAY OVERDONE ON ACCOUNT OF THAT
MODEL KEEPING SURFACE DEWPOINTS UP IN THE UPPER 60S AND LOWER 70S
THIS AFTERNOON...WHEREAS IN REALITY THE DEWPOINT IS MUCH MORE LIKELY
TO MIX OUT DOWN TO THE LOWER 60S OR EVEN UPPER 50S AT THE WARMEST
PART OF THE DAY. DIFFERENTIAL HEATING SHOULD DO THE TRICK AND
PROVIDE FOR SCATTERED COVERAGE OVER THE MTNS...BUT ONCE AGAIN THE
PIEDMONT SHOULD SEE ONLY ISOLATED STORMS AT BEST...A CONCLUSION
WHICH IS ALSO BORNE OUT BY THE CONSENSUS OF THE CONVECTION ALLOWING
MODELS. WILL NOT RULE OUT AN ISOLATED SEVERE STORM OWING TO THE DRY
AIR AT MID LEVELS. ANY STORMS THAT DEVELOP SHOULD DISSIPATE WITH
LOSS OF HEATING THIS EVENING. EXPECT ANOTHER MILD NIGHT. THERE IS
SOME POSSIBILITY OF SCATTERED SHOWERS THAT DEVELOP IN THE IMPROVING
SOUTHERLY FLOW MOVING UP FROM GEORGIA AND ACROSS THE NC MOUNTAINS
TONIGHT...SO THE SLIGHT CHANCE POP WAS KEPT THROUGH THE OVERNIGHT
HOURS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AT 300 AM EDT TUESDAY...HEIGHTS WILL FALL OVER THE SOUTHERN
APPALACHIANS ON WEDNESDAY AND THURSDAY...AS AN UPPER RIDGE
PROGRESSES AWAY FROM THE EAST COAST...AND A HIGH AMPLITUDE UPPER
TROUGH AXIS CROSSES THE MS RIVER VALLEY. BY LATE THURSDAY NIGHT...
THE TROUGH AXIS WILL BE CROSSING THE GULF STATES...AND A STRONG
SHORTWAVE WILL BE CROSSING THE TN RIVER VALLEY.
WEAK HIGH PRESSURE EXTENDING FROM THE ATLANTIC WILL LOSE IS GRIP ON
THE CAROLINAS AND GA ON WEDNESDAY...SUPPLANTED BY A MODEST MOIST
INFLOW FORM THE GULF AND ATLANTIC. MEANWHILE...A SURFACE WAVE WILL
FORM ALONG A COLD FRONT IN THE LOWER MS RIVER VALLEY...MOVING TO W
TN BY LATE IN THE DAY. THE WAVE MOVES INTO THE OH RIVER VALLEY ON
WEDNESDAY NIGHT...WHILE THE TRAILING COLD FRONT APPROACHES GA AND
THE WESTERN CAROLINAS. THE BEST MOIST INFLOW REACHES OUR AREA JUST
AHEAD OF THE FRONT...BEFORE DAWN ON THURSDAY.
THE FRONT MOVES SLOWLY ACROSS THE MOUNTAINS ON THURSDAY...WITH
ANOTHER SURFACE WAVE FORMING OVER THE SAVANNAH RIVER VALLEY. THE
MODELS SHOW ROBUST SHEAR BUT MODEST INSTABILITY AHEAD OF THIS
FRONT...AND A MENTION OF POSSIBLE SEVERE WEATHER WILL BE MAINTAINED
IN THE HAZARDOUS WEATHER OUTLOOK. AN INCREASING SOUTHEASTERLY
UPSLOPE FLOW AND ISENTROPIC UPGLIDE WILL SUPPORT PRECIPITATION
PRODUCTION. SEVERAL INCHES OF RAINFALL ARE POSSIBLE...WITH THE
GREATEST AMOUNTS EXPECTED ALONG THE SOUTH FACING BLUE RIDGE
ESCARPMENT...WHERE NC...GA AND SC MEET. THE COLD FRONT MOVES SLOWLY
ACROSS THE FOOTHILLS AND PIEDMONT ON THURSDAY EVENING...LEAVING OUR
AREA BY FRIDAY MORNING.
TEMPERATURES WILL RUN SIGNIFICANTLY ABOVE NORMAL ON WEDNESDAY AND
WEDNESDAY NIGHT...UNDER THE INFLUENCE OF THE UPPER RIDGE DURING THE
DAY...AND INCREASING CLOUDS AT NIGHT. HIGH TEMPERATURES THURSDAY
WILL BE WELL BELOW NORMAL DUE TO CLOUDS AND PRECIPITATION. LOW
TEMPERATURES THURSDAY NIGHT WILL RUN ONLY SLIGHTLY BELOW NORMAL...AS
COLD ADVECTION WILL HAVE ONLY BEGUN.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AT 300 AM EDT TUESDAY...ON FRIDAY MORNING A CLOSED UPPER LOW WILL BE
OVER WI...WITH A TROUGH EXTENDING SOUTH TO THE GULF COAST...AND A
HIGH AMPLITUDE UPPER RIDGE OVER THE WESTERN ATLANTIC. THE UPPER LOW
DRIFTS NE INTO ONTARIO BY SATURDAY MORNING. THE LOW OPENS UP AND
REACHES THE QUEBEC BORDER BY SUNDAY...WHILE THE DEAMPLIFYING TROUGH
REACHES THE CENTRAL AND SOUTHERN APPALACHIANS. ON MONDAY THE TROUGH
AXIS MOVES TO THE EAST COAST...WHILE AND UPPER RIDGE AMPLIFIES OVER
THE MS RIVER VALLEY. AMPLIFICATION CONTINUES INTO TUESDAY...WITH
LITTLE PROGRESSION...LEADING TO NW FLOW ALOFT OVER GA AND THE
CAROLINAS.
A DEPARTING COLD FRONT WILL BE EAST OF OUR AREA ON FRIDAY...BUT
MOISTURE ASSOCIATED WITH THE CLOSED UPPER LOW MAY EXTEND FAR ENOUGH
SOUTH TO AFFECT THE SOUTHERN APPALACHIANS...WHERE UPSLOPE FLOW
SHOWERS MAY BE POSSIBLE. A MID LEVEL COOL POOL ASSOCIATED WITH THE
UPPER LOW MAY ENHANCE INSTABILITY TO THE POINT WHERE THUNDERSTORMS
WOULD BE FAVORED.
COOL HIGH PRESSURE SETTLES OVER THE SOUTHEAST ON SATURDAY. MOISTURE
ASSOCIATED WITH SHORTWAVE ROUNDING THE BASE OF THE UPPER TROUGH AND
A STATIONARY FRONT IN THE PLAINS AND MID MS RIVER VALLEY IS EXPECTED
TO SPREAD EAST OVER THE SURFACE HIGH...BECOMING MORE NOTICEABLE BY
SUNDAY AND MONDAY. SMALL POPS WILL BE CARRIED AS MOISTURE INCREASES.
TEMPERATURES WILL RUN BELOW NORMAL IN THE WAKE OF THE COLD
FRONT...THEN WILL WARM TO NEAR NORMAL ON MONDAY AS THE COOL AIRMASS
MODIFIES.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AT KCLT...THE BERMUDA HIGH WILL HOLD ON FOR ONE MORE DAY BRINGING
SOUTHERLY WINDS THROUGH THE PERIOD. A SCT CU DECK UP AROUND 5000
FEET WILL DISSIPATE AROUND SUNSET. A FEW SHRA MAY YET DEVELOP AND
I/VE KEPT A VCSH GROUP FOR A FEW HOURS DURING MAX HEATING TDA. NOT
EXPECTING ANY FOG OR STRATUS TONIGHT. LATER WEDNESDAY AFTERNOON A
LITTLE BETTER COVERAGE OF SHOWERS MAY DEVELOP...BUT THIS WILL BE
WELL AFTER THE VALID PERIOD OF THE TAFS.
ELSEHWERE...MOST OF THE MODELS AGREE THAT THE SHOWERS AND
THUNDERSTORMS DEVELOPING OVER THE NC MTNS WILL CONTINUE TO DRIFT TO
THE NORTH AND AWAY FROM KAVL. I DID KEEP VCSH IN THE TAF...BUT HAVE
REMOVED ANY THUNDER. OVERNIGHT VALLEY FOG SHOULD DEVELOP ONCE AGAIN
IN THE FRENCH BROAD VALLEY...THOUGH WITH BNDRY LAYER DEWPOINTS
EXPECTED TO FALL A LITTLE OVERNIGHT I DIDN/T GO ANY LOWER THAN THE
PREVIOUS SHIFT/S 2SM. VFR AT THE REMAINING SITES THROUGH 18 UTC WED.
OUTLOOK...WEDNESDAY SHOULD BE LARGELY DRY. ON THURSDAY A SLOW MOVING
COLD FRONT WILL YIELD A BETTER CHANCE OF RESTRICTIONS IN PROLONGED
PRECIPITATION AND THUNDERSTORMS. EXPECT VFR AGAIN FRIDAY.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-17Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 88% MED 65% LOW 31%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 89%
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...JAT
NEAR TERM...MCAVOY/PM
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...MCAVOY
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
259 PM MDT TUE MAY 13 2014
.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 220 PM MDT TUE MAY 13 2014
LONG WAVE TROF JUST EAST OF THE CWA THIS MORNING WITH UPSTREAM
RIDGE JUST OFF THE WEST COAST. LONG WAVES HAVE BEEN VERY SLOW
MOVING LAST SEVERAL DAYS AND ARE FORECAST TO REMAIN NEARLY
STATIONARY THROUGH THURSDAY. AMPLIFICATION THAT HAD BEEN UNDERWAY
HAS CEASED. SO LITTLE CHANGE IN THE LONG WAVE PATTERN IS EXPECTED
DURING THE SHORT TERM.
WEAK SHORT WAVE TROFS ARE MOVING SOUTHWARD BEHIND THE LONG WAVE
TROF OVER OUR CWA. ONE HAS EXITED THE AREA WITH ANOTHER VERY
SUBTLE ONE JUST BARELY VISIBLE ON THE WATER VAPOR LOOP APPROACHING
THIS AFTERNOON. HRRR MODEL HAS BEEN CONSISTENTLY SHOWING WIDELY
SCATTERED SHOWERS DEVELOPING THIS AFTN OVER NE WYOMING AND THE
BLACK HILLS...BUT WITH A BIT STRONGER AND MORE WELL ORGANIZED
SHOWERS AND A FEW TSTMS FORECAST TO DEVELOP WITH THE SHORT WAVE
LATE AFTN INTO THIS EVENING OVER NE WYOMING INTO THE BLACK HILLS.
THERE IS SUPPORT FOR THIS DEVELOPMENT IN MODEST 700 MB Q VECTOR
CONVERGENCE SHOWN BY THE NAM. TOMORROW NIGHT THERE IS A HINT OF
ANOTHER WAVE...BUT LESS CERTAINTY ACCOMPANIES THIS FEATURE.
CONVECTION IS ALSO SUGGESTED BY THE GFS FORECASTS OF 500MB
TEMPERATURES NEAR 5 STANDARD DEVIATIONS BELOW THE SEASONAL MEAN.
WITH STRONG SFC HEATING...THIS IMPLIES CONSIDERABLE INSTABILITY
NEXT SEVERAL DAYS.
STAYED CLOSE TO GUIDANCE WITH TEMPERATURES AND USED THE NAM FOR
SURFACE WINDS...WITH SOME UPWARD ADJUSTMENT IN AFTN SPEEDS.
BECAUSE WE HAVE BEEN QUITE COLD LATELY...I DECIDED NOT TO ISSUE
FROST/FREEZE ADVISORY.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 220 PM MDT TUE MAY 13 2014
NORTHWEST FLOW WILL CONTINUE THROUGH THE END OF THE WEEK WITH FAST
MOVING UPPER DISTURBANCES AND A NEARLY STATIONARY FRONTAL BOUNDARY
OVER THE HIGH PLAINS. THIS WILL RESULT IN NEAR DAILY CHANCES FOR
SHOWERS...ESPECIALLY OVER NORTHEAST WYOMING AND FAR WESTERN SOUTH
DAKOTA. SLIGHTLY BELOW AVERAGE TEMPS ARE EXPECTED THROUGH THE END OF
THE WEEK. AN UPPER TROUGH/CUT OFF LOW IS PROGGED TO DEVELOP EARLY
NEXT WEEK OVER THE NW CONUS. UPPER FLOW WOULD THEN BECOME MORE SWRLY
WITH WARM AND MOIST AIR ADVECTING IN FROM THE S/SE. THIS WILL
INCREASE CHANCES FOR THUNDERSTORMS FOR THE EARLY PART OF NEXT WEEK
ALONG WITH NEAR TO SLIGHTLY ABOVE AVERAGE TEMPERATURES.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 220 PM MDT TUE MAY 13 2014
ISOLD-SCT -SHRA...AND POSSIBLY A FEW -TSRA...WILL OCCUR OVER
NORTHEASTERN WYOMING AND PARTS OF WESTERN SOUTH DAKOTA THIS EVENING.
THERE IS A ALSO A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ON
WEDNESDAY AFTERNOON. MVFR CONDS ARE POSSIBLE NEAR ANY SHOWERS OR
THUNDERSTORMS...OTHERWISE VFR CONDITIONS WILL PREVAIL.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...BARBER
LONG TERM...77
AVIATION...10