Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/01/15
AREA FORECAST DISCUSSION
NWS RENO NV
141 PM PDT WED APR 29 2015
.SYNOPSIS...
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THIS WEEK. A WEAK LOW
PRESSURE TROUGH WILL DEVELOP AND CONTINUE NEAR THE WEST COAST FOR
THE END OF THE WEEK AND THIS WEEKEND. THIS WILL RESULT IN A RETURN
OF THUNDERSTORMS.
&&
.SHORT TERM...
SATELLITE IMAGERY SHOWED A SHORTWAVE MOVING THROUGH THE PACNW
WITH A COLD FRONT APPROACHING NORTHEAST CA AND NORTHERN NV THIS
AFTERNOON. THE FRONT IS FORECAST TO ADVANCE SOUTHEASTWARD ACROSS
THE BASIN AND RANGE TONIGHT. A NORTHEAST GRADIENT WILL HELP KEEP
SURFACE WINDS UP A BIT OVERNIGHT WHICH WILL KEEP TEMPERATURES
RATHER MILD TONIGHT. HOWEVER MOST AREAS WILL SEE SLIGHTLY COOLER
HIGH TEMPERATURES ON THURSDAY. 12Z MODELS AND THE LATEST HIGH
RESOLUTION HRRR STILL SUGGEST A POTENTIAL FOR ISOLATED SHOWERS AND
THUNDERSTORMS AHEAD OF THIS FRONT GENERALLY NORTH OF SUSANVILLE
AND GERLACH THROUGH THIS EVENING AND WE HAVE MAINTAINED THIS
POSSIBILITY.
THE AIRMASS BEGINS TO MODIFY THURSDAY AFTERNOON AND ALL BUT WASHES
OUT BY FRIDAY AS TEMPERATURES CLIMB BACK IN THE 70S SIERRA AND 80S
LOWER ELEVATIONS. FRIDAY COULD EVEN BE WARMER THAN THE PAST COUPLE
OF DAYS WITH SOME GUIDANCE SHOWING HIGHS IN THE MID 80S FOR SOME
WESTERN NV VALLEYS INCLUDING RENO. THE FLOW WILL BE LIGHT THU-FRI
WITH INCREASING CONVERGENCE AND INSTABILITY ALONG THE SIERRA. SO
WE ARE STILL LOOKING FOR THUNDERSTORMS TO DEVELOP MAINLY OVER MONO
AND MINERAL COUNTIES THURSDAY AND THEN SPREADING NORTHWARD TO
RENO-TAHOE FRIDAY. A WEAK SHORTWAVE WILL MOVE THROUGH THE AREA
FRIDAY NIGHT WHICH MAY KEEP SHOWERS GOING INTO SATURDAY MORNING.
.LONG TERM...SATURDAY THROUGH WEDNESDAY...
A SUMMER-LIKE PATTERN CONTINUES TO BE PRESENTED IN MODEL GUIDANCE
FOR THE WEEKEND INTO EARLY NEXT WEEK. IT`S HARD TO BELIEVE, BUT
WE`RE ALREADY ANALYZING THERMAL TROUGHS FOR THUNDERSTORM INITIATION
AND SUBSEQUENT MOVEMENT. MODELS HAVE BEEN FAIRLY CONSISTENT OVER THE
LAST COUPLE OF DAYS, SO FORECASTER CONFIDENCE IS INCREASING IN
DETERMINISTIC AND ENSEMBLE SOLUTIONS. AS SUCH, ONLY MODEST CHANGES
WERE MADE TO EXISTING FORECAST.
THERMAL TROUGH PLACEMENT OVER THIS WEEKEND THROUGH TUESDAY AFTERNOON
WILL GENERALLY BE IN THE NEVADA INTERIOR. HOWEVER, THERE IS A SLIGHT
THICKNESS RIDGE OVER THE SIERRA AS WELL. ALL OF THIS SUGGESTS
THUNDERSTORM INITIATION OVER THE SIERRA AND SIERRA FRONT CONVERGENT
ZONES WITH AN EASTWARD STORM MOTION INTO NEVADA THROUGH THE
AFTERNOONS. THE TWO THICKNESS RIDGES MAY ALSO INDICATE A CHAOTIC
INITIATION BEFORE THE AFTERNOON ZEPHYR KICKS CELLS OFF THE TERRAIN.
THE FOCUS FOR CONVECTION WILL GENERALLY BE SOUTH OF HIGHWAY 50 ON
SATURDAY SPREADING NORTHWARD EACH DAY THROUGH TUESDAY. THUNDERSTORMS
HAVE BEEN REINTRODUCED FOR NORTHERN LASSEN AND WASHOE COUNTY
SATURDAY AFTERNOON WHERE MODELS SUGGEST ACTIVITY ALONG THE LASSEN
CONVERGENCE ZONE. ADDITIONALLY, HAVE KEPT MENTION OF SHOWERS
OVERNIGHT MONDAY INTO TUESDAY MORNING AND AGAIN TUESDAY NIGHT INTO
WEDNESDAY AS A TROUGH DROPS OUT OF THE PACIFIC NORTHWEST. THIS
ADDITIONAL LIFT SHOULD BE SUFFICIENT TO SUPPORT MORE COVERAGE OF
SHOWERS OVER THE NIGHT HOURS AND ISOLATED CONVECTION DURING THE DAY.
TEMPERATURES WILL COOL A LITTLE EACH DAY AS CONVECTIVE CLOUD
CONTAMINATION INCREASES. GENERALLY, TEMPERATURES WILL BE AROUND 10
DEGREES ABOVE SEASONAL AVERAGES OVER THE WEEKEND. BY TUESDAY
AFTERNOON TEMPERATURES TREND COOLER THROUGH WEDNESDAY, BACK TO
AVERAGE, WITH A TROUGH DROPPING INTO NORTHWESTERN NEVADA. LOCALLY
BREEZY WINDS WILL BE POSSIBLE WITH THIS TROUGH. WITH DRY SURFACE
CONDITIONS IN PLACE WE COULD SEE SOME ISOLATED FIRE WEATHER
CONCERNS TUESDAY AFTERNOON BEFORE TEMPERATURES COOL INTO
WEDNESDAY. BOYD
&&
.AVIATION...
VFR CONDITIONS AT ALL TERMINALS EXCEPT FOR THE POTENTIAL OF AN HOUR
OR SO OF FOG AT KTRK AROUND 14/15Z. SOUTHWESTERLY TO WESTERLY
WINDS CAN BE EXPECTED TODAY WITH TYPICAL AFTERNOON BREEZES GUSTING
UP TO 25KTS. A WEAK TROUGH PASSES TONIGHT TURNING FLOW OUT OF THE
NORTHEAST TO EAST BY THURSDAY AFTERNOON
CHANCES OF PULSE THUNDERSTORMS INCREASE THURSDAY THROUGH THE WEEKEND
MAINLY OCCURRING IN THE SIERRA. THUNDERSTORM POTENTIAL STARTS IN
MONO/MINERAL COUNTIES AND CREEPS NORTHWARD INTO THE NORTHERN SIERRA
BY MONDAY. LOCALLY GUSTY AND ERRATIC WINDS WILL BE POSSIBLE IN THE
VICINITY OF THESE CELLS.
A TROUGH MOVES INTO THE FORECAST BY TUESDAY EVENING AND WEDNESDAY.
MORE EXPANSIVE COVERAGE OF SHOWERS AND THUNDERSTORMS CAN BE
EXPECTED AS INSTABILITY SPREADS ACROSS THE SIERRA INTO THE NEVADA
INTERIOR. LOCALLY BREEZY CONDITIONS WILL BE LIKELY AS THIS TROUGH
MOVES THROUGH. BOYD
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS PUEBLO CO
310 PM MDT WED APR 29 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 250 PM MDT WED APR 29 2015
UPPER RIDGE OVER THE AREA TODAY HAS SUPPRESSED CONVECTION OVER
THE AREA. HOWEVER...HRRR AND RAP STILL SUGGEST A SMALL WINDOW FOR
SOME ISOLATED SHOWERS/THUNDERSTORMS ACROSS THE SOUTHWEST MOUNTAINS
AND SANGRE DE CRISTO MOUNTAINS LATE THIS AFTERNOON AND EVENING.
SEEING SOME CU DEVELOPMENT ACROSS THE EASTERN SAN JUANS AND
SOUTHERN SANGRES...SO WILL MAINTAIN SOME LOW GRADE POPS FOR THESE
AREAS. MAIN IMPACT WILL BE AN ISOLATED LIGHTNING STRIKE ALONG WITH
GUSTY WINDS.
ON THURSDAY...A DISTURBANCE WILL MOVE THROUGH THE NRN U.S. ROCKIES
DURING THE AFTERNOON. THIS WILL SEND A PREFRONTAL WIND SHIFT INTO
THE PIKES PEAK REGION DURING THE AFTERNOON. INCREASING MID LEVEL
MOISTURE AHEAD OF THE DISTURBANCE WILL PRODUCE A ROUND OF ISOLATED
TO LOW END SCATTERED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS.
MEANWHILE...WITH THE BOUNDARY STALLING ACROSS NORTHERN EL PASO THIS
WILL ALSO PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT DURING THE
LATE AFTERNOON AND EARLY EVENING. THUNDERSTORMS WILL REMAIN FAIRLY
HIGH BASED...WITH ERRATIC GUSTY WINDS AND LIGHTNING THE PRIMARY
STORM THREATS. -KT
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 250 PM MDT WED APR 29 2015
...INCREASING HEAVY RAIN THREAT EARLY NEXT WEEK...
OUR AREA WILL BE UNDER QUASI-ZONAL FLOW ALOFT FOR THE END OF THE
WEEK. A COUPLE WEAK DISTURBANCES WILL MOVE THROUGH THE FLOW WHICH
WILL HELP GENERATE THUNDERSTORMS AND SHOWERS EACH AFTERNOON AND
EVENING. A FRONTAL PUSH OVER THE PLAINS WILL LEAD TO SLIGHLTY
COOLER WX ON FRIDAY...WITH TEMPS IN THE 70S OVER THE PLAINS.
LOW CLOUDS OVER THE PLAINS SHOULD DISSIPATE BY LATE MORNING...
AND INCREASED UPSLOPE OVER THE PLAINS FRI AFTERNOON SHOULD ALSO
LEAD TO AN INCREASE IN CONVECTION IN THE AFTERNOON AND EVE. A
COUPLE STORMS MAY BE ON THE STRONG SIDE...SO WILL HAVE TO WATCH
THE BURN SCARS FRI AFTERNOON AND EVE...BUT STORMS SHOULD BE MOVING
AT A DECENT CLIP AND WILL DISSIPATE OFF TO THE EAST FRI EVE.
OVER THE WEEKEND...INCREASED ZONAL FLOW WILL BRING JUNE-LIKE TEMPS
TO THE REGION...WITH MID 80S A POSSIBILITY FOR THE WARM SPOTS
OVER THE PLAINS. EXPECT DIURNAL STORMS AGAIN...FORMING OVER THE
HIGHER TRRN AND SHIFTING TO THE PLAINS IN THE EVENING. WILL SEE
CONVECTION COVERAGE INCREASE THROUGH THE WEEKEND AS A STRONGER
SHORT-WAVE MOVES OUT OF THE PACNW AND THEN THROUGH THE NRN
ROCKIES.
BY MONDAY...A CUT-OFF LOW OVER THE BAJA REGION WILL BEGIN MOVING
INTO THE DESERT SW...AND INCREASED SRLY FLOW IN THE MID LEVELS
WILL BRING INCREASED MOISTURE TO SE CO. SO...HEAVY RAIN CHANCES
WILL BE ON THE INCREASE MONDAY AND ESPECIALLY BY TUESDAY...AS THE
LOW MOVES INTO THE FOUR CORNERS REGION. MAIN THREAT WILL BE HEAVY
RAIN BUT INCREASING SHEAR COULD ALSO BRING A FEW STRONG TO SVR
STORMS AS THE LOW GETS CLOSER. AFTER TUE...MODELS DIVERGE A BIT
ON HOW QUICKLY THE LOW EJECTS TO OUR NORTH AND EAST...AND ALSO THE
IMPACT OF A SECOND LOW PRESSURE SYSTEM MOVING INTO THE PACNW.
SO...UNCERTAINTY IS PRETTY HIGH BEYOND TUE...BUT IT LOOKS TO BE
UNSETTLED THROUGH AT LEAST A GOOD PORTION OF NEXT WEEK. ROSE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 250 PM MDT WED APR 29 2015
VFR CONDITIONS EXPECTED TONIGHT THROUGH THURSDAY MORNING. WINDS
TONIGHT WILL BE LIGHT AND DIURNALLY DRIVEN WITH SPEEDS UNDER 10
KTS. WINDS ON THURSDAY WILL START OUT NORTHERLY AT KCOS...THEN
SWING AROUND FROM THE SOUTHEAST DURING THE AFTERNOON WITH A WEAK
FRONT LURKING JUST TO THE NORTH OF THE TERMINAL. THIS WILL PROVIDE
A FOCUS FOR ISOLATED THUNDERSTORM DEVELOPMENT IN THE AFTERNOON.
THESE WILL BE HIGH BASED AND CAPABLE OF PRODUCING LOCAL ERRATIC
GUSTY WINDS UP TO 35 KTS. WINDS WILL SWITCH OUT OF THE NORTH FOR
BOTH KCOS AND KPUB THURSDAY EVENING AS A STRONGER PUSH OF COOLER
AIR DROPS IN FROM THE NORTH. KALS WILL REMAIN VFR THROUGH THE
PERIOD WITH THUNDERSTORMS LESS LIKELY TO IMPACT THE TERMINAL.
-KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...ROSE
AVIATION...KT
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
127 AM MDT WED APR 29 2015
.UPDATE...
ISSUED AT 125 AM MDT WED APR 29 2015
STILL WONDERING IF FOG WILL FORM ON THE PLAINS DURING THE NEXT
FEW HOURS AS LATEST MODEL GUIDANCE INDICATES. HAVE SEEN A GRADUAL
REDUCTION IN TEMP/DEWPOINT SPREADS ACROSS THE SOUTH PLATTE RIVER
BASIN LARGELY DUE TO FALLING DRYBULB TEMPS UNDER A CLEAR SKY. DO
NOT SEE ANY HINT OF FOG YET ON 3.9U IR SATELLITE IMAGERY OR IN SFC
OBS. HOWEVER THE 00Z NAM AND LATEST HRRR...WRF AND RAP RUNS
CONTINUE TO INDICATE OF FOG FORMING IN THE VICINITY OF A WEAKLY
ORGANIZED DENVER CYCLONE JUST NORTHEAST OF DENVER`S INTERNATIONAL
AIRPORT WITHIN THE NEXT HOUR OR TWO. WEAK CYCLONIC TURNING IS
EVIDENT IN THIS AREA ACCORDING TO SFC OBS. HOWEVER...BASED ON THE
CURRENT RATE OF COOLING...SUSPECT FOG DEVELOPMENT...ASSUMING IT
HAPPENS...WON/T BEGIN UNTIL AFTER 09Z. AGAIN BASED ON THE ABOVE
MENTIONED MODELS...COULD SEE FOG FORMING ALONG A WIND DEFORMATION
AXIS EXTENDING NORTHEAST FROM ABOUT DIA. HRRR...RAP AND WRF
INDICATE THE BEST AREA FOR FOG ACROSS SOUTHERN WELD COUNTY FROM
10Z-13Z THIS MORNING. WHEREAS THE NAM INDICATES THE HIGHEST RH
VALUES CLOSER TO THE DENVER METRO AREA. HOWEVER AS LONG AS DRYING
SWLY WINDS REMAIN IN PLACE...DON/T SEE THIS HAPPENING IN THE
METRO AREA. THAT SAID...WILL FINE TUNE THE AREA OF FOG COVERAGE
TO INCLUDE THE NERN CORNER OF THE DENVER METRO AREA...I.E. DIA...
AND MOVE UP THE TIME OF FOG FORMATION ABOUT AN HOUR. FOR NOW WILL
STICK WITH PATCHY FOG COVERAGE. OTHERWISE REST OF 1ST PERIOD
FORECAST APPEARS ON TRACK.
UPDATE ISSUED AT 929 PM MDT TUE APR 28 2015
NO CHANGES AT THIS TIME. CLEARING GOING NICELY. LOOKING PRETTY
MARGINAL FOR FOG BUT STILL A THREAT FOR SOME PATCHES AROUND
SUNRISE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 320 PM MDT TUE APR 28 2015
VISIBLE SATELLITE SHOWS CLOUDS TRAPPED UNDER THE INVERSION ARE
SLOWLY ERODING ALONG THE NORTHERN FRONT RANGE THIS
AFTERNOON...AND WILL DO THE SAME OVER THE PLAINS THROUGH LATE
AFTERNOON AND EVENING AS FLOW TURNS WESTERLY. THE CLEARING SKIES
BUT LEFT OVER BOUNDARY LAYER MOISTURE COULD RESULT IN PATCHY FOG
DEVELOPMENT LATE TONIGHT IN LOW LYING AREAS OF THE PLAINS...AND
PARK COUNTY AS WELL WHERE THERE IS STILL SOME SNOW COVER.
OTHERWISE LOOK FOR CLEAR SKIES OVERNIGHT.
ON WEDNESDAY...SHARP UPPER LEVEL RIDGE AXIS WILL SHIFT EAST ACROSS
COLORADO. THIS WILL BRING WARMER TEMPERATURES AND SUNNY SKIES TO
THE FORECAST AREA. ONLY A FEW MID LEVEL CUMULUS CLOUDS EXPECTED
FOR THE AFTERNOON HOURS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 PM MDT TUE APR 28 2015
AFTER A DRY AND WARM DAY ON THURSDAY...THE REST OF THE FORECAST
PERIOD LOOKS LIKE IT IS GOING TO BE A REPETITIOUS PATTERN WITH
AFTERNOON AND EVENING THUNDERSTORMS EACH DAY. THURSDAY WILL
FEATURE THE UPPER RIDGE AXIS CENTERED OVER COLORADO AS A COLD
FRONT AND UPPER LEVEL DISTURBANCE APPROACH THE STATE FROM THE
NORTH AND NORTHWEST. THE SURFACE COLD FRONT IS NOT EXPECTED UNTIL
SOMETIME THURSDAY EVENING...SO THE AFTERNOON SHOULD BE A WARM ONE
WITH HIGHS IN THE MID TO UPPER 70S. MOUNTAIN AREAS MAY SEE A
LITTLE BIT OF SHOWER ACTIVITY LATE IN THE AFTERNOON. THROUGH THE
EVENING...AS THE SURFACE FRONT MOVES THROUGH...IT WILL BE POSSIBLE
THAT A ROUND OF SHOWERS AND THUNDERSTORMS WILL DEVELOP AND MOVE
ACROSS THE PLAINS.
FROM FRIDAY THROUGH THE MIDDLE OF NEXT WEEK IT APPEARS THAT GULF
MOISTURE IS GOING TO BE ABLE TO MOVE NORTHWARD OVER THE HIGH
PLAINS UNDERNEATH INITIALLY WEAK UPPER RIDGING OVER THE SOUTHERN
ROCKIES AND THEN BY NEXT MONDAY THE UPPER PATTERN SHIFTS TO WEAK
UPPER TROUGHING WHICH WILL INCREASE SOUTHWESTERLY WINDS AT MID AND
UPPER LEVELS. AS LOW LEVEL GULF MOISTURE ADVECTS INTO EASTERN
COLORADO...IT WILL HELP DE-STABILIZE THE AIRMASS EACH AFTERNOON
AND FUEL ISOLATED-SCATTERED THUNDERSTORMS. WINDS ALOFT WILL REMAIN
LIGHT TO MODERATE...SO NO STRONG OR ORGANIZED CONVECTIVE SYSTEMS
ARE EXPECTED...BUT EACH AFTERNOON AND EVENING WILL NEED TO MENTION
THE CHANCE OF SHOWERS TO INTERFERE WITH ANY PLANNED OUTDOOR
ACTIVITIES. TEMPERATURES WILL BE AROUND TO SLIGHTLY WARMER THAN
NORMAL.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 125 AM MDT WED APR 29 2015
HAVE RETURNED VICINITY FOG NOTATION TO KBJC AND KDEN TERMINAL
FORECASTS AFTER REMOVING IT EARLIER THIS EVENING. MESOSCALE MODELS
CONTINUE TO INDICATE AN AREA OF FOG COVERING MOST OF ADAMS AND
MORGAN COUNTIES...SOUTHERN SECTIONS OF WELD COUNTY...LOW AREAS
ALONG THE S. PLATTE RIVER IN LOGAN COUNTY AND ACROSS NORTHEAST
SECTIONS OF THE DENVER METRO AREA...INCLUDING KDEN. THE FORMATION
OF FOG IN THE DENVER WILL ALL DEPEND ON A SHIFT TO A W-NWLY WIND.
MODELS NEVER INDICATE THIS HAPPENING AT KBJC AND KAPA. FOR THE
TIME BEING...WILL HANG ONTO VICINITY FOG IN THE KBJC AND KDEN TAFS
FROM 09Z-10Z TO 13Z-14Z...RESPECTIVELY. IT IS POSSIBLE THAT THE
VSBY AT KDEN COULD BRIEFLY DROP TO 2-3 MILES....BUT CONFIDENCE IN
THIS OCCURRING IS LOW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BAKER
SHORT TERM...BARJENBRUCH
LONG TERM...DANKERS
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1116 PM MDT TUE APR 28 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 250 PM MDT TUE APR 28 2015
QUIET WEATHER IN THE SHORT TERM AS THE WESTERN U.S. UPPER RIDGE
SHIFTS EASTWARD OVER COLORADO. RESIDUAL MOISTURE AND INSTABILITY
OVER THE CONTINENTAL DIVIDE TODAY WILL LEAD TO SOME ISOLATED TO
SCATTERED SHOWERS AND EMBEDDED THUNDERSTORM DEVELOPMENT...BUT WITH
DEW POINTS IN THE 20S...NOT EXPECTING MUCH IN THE WAY OF
PRECIPITATION. HIGHER AREAS COULD PICK SEE UP TO AN INCH OF
SNOWFALL IN SPOTTY AREAS. OTHERWISE SOUTHEAST PLAINS LOOK VERY
STABLE...AND ALTHOUGH HRRR IS PRINTING OUT SOME LIGHT QPF IN SPOTTY
AREAS OF THE SOUTHEAST MOUNTAINS...AM NOT TOO OPTIMISTIC THAT THIS
WILL HAPPEN GIVEN THE PRESENCE OF A CAP IN MODEL SOUNDINGS. WILL
CONFINE POPS TO THE CONTDVD REGION FOR NOW. ANY PRECIPITATION
SHOULD DIMINISH QUICKLY THIS EVENING WITH LOSS OF HEATING. LEE TROF
DEVELOPING OVERNIGHT SHOULD KEEP TEMPERATURES WARMER THAN LAST
NIGHT...PARTICULARLY ALONG THE LOWER EASTERN SLOPES OF THE SE MTS/I-
25 CORRIDOR.
WEDNESDAY LOOKS EVEN DRIER THAN TODAY...THOUGH SOME
SHOWERS/THUNDERSTORMS STILL LOOK POSSIBLE ACROSS THE SOUTHWEST MTS
IN THE AFTERNOON. OTHERWISE...TEMPERATURES SHOULD REBOUND INTO THE
70S FOR THE PLAINS...60S FOR THE VALLEYS...40S AND 50S ACROSS THE
MOUNTAINS. -KT
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 250 PM MDT TUE APR 28 2015
WEDNESDAY NIGHT-FRIDAY NIGHT...WEAK NORTH TO NORTHWEST FLOW ALOFT
ACROSS THE STATE WEDNESDAY NIGHT WITH UPPER LEVEL RIDGING BUILDING
INTO THE STATE BECOMES MORE WESTERLY THROUGH THE DAY THURSDAY...AS A
SHORT WAVE EMBEDDED WITHIN THE STRONGER WESTERLY FLOW ALOFT ACROSS
THE NORTHERN TIER OF STATES TRANSLATES ACROSS THE GREAT BASIN. THIS
EMBEDDED WAVE IS PROGGED TO CONTINUE ACROSS SOUTHERN WYOMING AND
NORTHERN COLORADO THURSDAY NIGHT WITH THE TAIL END OF THE SYSTEM
SLIDING ACROSS THE AREA FRIDAY AFTERNOON AND EVENING.
ANY CONVECTION ACROSS MAINLY THE SOUTHWESTERN MTS TO DIMINISH
QUICKLY WEDNESDAY EVENING WITH SUBSIDENCE AND WARMING ALOFT UNDER
THE BUILDING RIDGE. SOME INCREASED MOISTURE WITHIN THE INCREASING
WESTERLY FLOW ALOFT HELPS TO DEVELOP GENERALLY ISOLATED CONVECTION
OVER AND NEAR THE HIGHER TERRAIN ON THURSDAY...WITH DOWNSLOPE FLOW
AND WARM AIR ALOFT HELPING TO BOOST TEMPERATURES INTO THE 70S AND
80S ACROSS THE LOWER ELEVATIONS THURSDAY...WITH MAINLY 50S AND 60S
ACROSS THE HIGHER TERRAIN. LATEST MODELS ARE A TAD FURTHER SOUTH
WITH THE PASSING WAVE THURSDAY NIGHT...OWNING TO A STRONGER COLD
FRONT MOVING ACROSS THE SOUTHEASTERN PLAINS AND A FEW POSSIBLE
SHOWERS OR STORMS ALONG AND BEHIND THE FRONT INTO EARLY FRIDAY
MORNING. INCREASING MOISTURE AND THE TAIL END OF THE PASSING WAVE TO
HELP DESTABILIZE THE ATMOSPHERE ON FRIDAY...WITH ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING OVER AND NEAR THE MTS
LATE FRIDAY MORNING AND AFTERNOON...WITH STORMS SPREADING OUT ACROSS
THE EASTERN PLAINS LATE FRIDAY AFTERNOON AND EVENING. SOME OF THESE
STORMS COULD BE ON THE STRONG SIDE ACROSS THE I-25 CORRIDOR AND
PLAINS...WITH INCREASING LOW LEVEL MOISTURE ACROSS THE PLAINS
WITHIN DEVELOPING LOW LEVEL UPSLOPE FLOW. FRIDAYS HIGHS TO BE SOME
5-10 DEGREES COOLER THAN THURSDAY...MOST NOTABLY ACROSS THE EASTERN
PLAINS.
SATURDAY-TUESDAY...GENERALLY WEAK WESTERLY FLOW PROGGED ACROSS THE
AREA THROUGH THE WEEKEND WITH SEVERAL MINOR WAVES MOVING THROUGH THE
FLOW LEADING TO MORE ISOLATED TO SCATTERED SHOWERS AND STORMS EACH
DAY WITH TEMPERATURES REMAINING AT OR SLIGHTLY ABOVE SEASONAL
AVERAGES. FLOW ALOFT BECOMES MORE SOUTHWESTERLY INTO EARLY NEXT WEEK
AS A WEATHER SYSTEM MOVING ACROSS THE DESERT SW COULD BRING BETTER
CHANCES FOR WIDESPREAD PRECIPITATION TO THE AREA INTO THE MIDDLE OF
NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1116 PM MDT TUE APR 28 2015
VFR CONDITIONS EXPECTED OVER THE NEXT 24 HOURS WITH LIGHT TERRAIN
DRIVEN WINDS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT/MW
LONG TERM...MW
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
119 PM EDT WED APR 29 2015
.SYNOPSIS...
A WEAKENING PRESSURE GRADIENT RESIDES OVER THE REGION TODAY. LOW
PRESSURE OVER THE GULF OF MEXICO WILL MOVE NORTHEASTWARD TO A
POSITION OFF THE SOUTHEASTERN COAST ON THURSDAY. IT WILL CONTINUE
TO TREK NORTHEASTWARD THROUGH THE END OF THE WORK WEEK. HIGH
PRESSURE WILL THEN BUILD IN BEHIND THE DEPARTING LOW FOR THE
WEEKEND AND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ANOTHER WONDERFUL SPRING DAY IN THE PHILLY AREA UNDER A WEAK
RIDGE ALOFT BETWEEN SLOWLY EASTWARD AND SEAWARD DEPARTING WESTERN
ATLANTIC CYCLONIC CIRCULATION AND SOUTHWARD GROWING GREAT LAKES
UPPER LOW. AT THE SFC, WEAK LOW PRESSURE FORMS OVER NNJ THIS
AFTERNOON.
A SUNNY START THEN SCATTERED STRATOCUMULUS THIS AFTERNOON
PROBABLY AOA 6000 FT.
NW WIND GUSTY AROUND 15-20 MPH DURING MID LATE MORNING THEN
SETTLES DOWN A BIT MID AFTERNOON. COASTAL COOLING SEA BREEZES
EXPECTED BUT POSSIBLY NOT WIDESPREAD (00Z/30 ECMWF MUCH MORE
WIDESPREAD THAN THE 00Z/06Z NCEP MODELS). FOLLOWED 09Z HRRR ON
GUSTS THIS MORNING.
THERE IS A MODELED SFC LOW OVER NNJ THAT MAY ASSIST SEA BREEZES
NNJ.
MAX TEMPS ABOUT 5 TO 7 DEGREES ABOVE NORMAL. TEMPERATURES WERE
INCREASED SLIGHTLY WITH THE 9:30 AM UPDATE THROUGHOUT THE DAY
AS A SHARP RISE WITH TEMPERATURES OCCURRED THIS MORNING. NO MAJOR
CHANGES WITH 12:30 PM UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
CLEAR TO PARTLY CLOUDY. A COMBINATION OF LEFTOVER STRATOCU THIS
EVENING AND CIRRUS FROM THE SOMEWHAT DEVELOPING SE COAST LOW. THE
CIRRUS MOSTLY THIN, OVERSPREADS LATER AT NIGHT FROM SSW TO NNE.
INVERSION AT 7000 FT MAY TRAP CLOUDS AT THAT LEVEL MOST OF THE
NIGHT. UNCERTAINTY REGARDING CIG TONIGHT.
LOWS 3 OR MORE DEGREES MILDER THAN THE VALUES OF THIS WEDNESDAY
MORNING...ESPECIALLY IF CLOUDS 7000 FT.
LIGHT W-SW WIND PROBABLY TURNS LIGHT NE MOST AREAS BY MORNING.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THU STARTS OUT DRY, WITH LOW PRES OFF THE SERN CONUS CST. THIS
LOW WILL MOVE NEWD THRU FRI, AS THE UPR LOW, NR THE OH VLY SWINGS
SEWD. PRECIP WILL DEVELOP NW OF THE SFC LOW AND PRBLY WITH THE UPR
LOW BUT EXACTLY WHERE REMAINS THE BIG QUESTION. IT STILL APPEARS
THE BEST CHCS OF PRECIP WILL BE OVER SRN AND ERN AREA, BUT THIS
WILL DEPEND ON THE TRACK OF THE LOW. ITS PSBL MOST LOCATIONS MAY
REMAIN DRY THRU THE DAY ON FRI, ESPECIALLY UP NORTH.
THE AXIS OF THE UPR TROF PASSES OFF THE CST FRI EVE AND THIS SHUD
FURTHER STEER THE LOW OUT TO SEA. HIGH PRES WILL BEGIN TO BUILD IN
FROM THE W. BOTH MDLS IMPLY SOME LIGHT PRECIP IN NW FLOW ON SAT.
ITS PSBL, BUT IT WOULD BE LOW POPS.
BEYOND SAT, THE HIGH BUILDS OVER THE REGION FOR MON AND MOVES OFF
THE CST MON NIGHT. THE ECMWF AND CMC HAVE DRY WX DURG THIS TIME
WITH WARM TEMPS AS SWLY FLOW INCREASES. THE GFS, ON THE OTHER HAND
SEEMS TO BE INEXPLICABLY WET AS WE GO MON SUN INTO MON, ESPECIALLY
UNDER HIGH PRES. THEREFORE, AM IGNORING ITS SOLN FOR NOW.
BY MON NIGHT INTO TUE, LOW PRES IN CANADA WILL BRING A CDFNT ACRS
THE NRN REACHES OF THE AREA. SOME PRECIP IS PSBL AND HAVE JUST
GONE WITH SOME LOW POPS. ONCE AGAIN, WHILE THE GFS HAS THE FRONT,
SIMILAR TO THE ECMWF, IT HAS QUITE A BIT MORE PRECIP AND WILL KEEP
THE DRIER TREND.
WITH THE EXCEPTION OF FRI, WHERE THE REGION WILL BE INFLUENCED BY
THE UPR LOW AND PSBLY THE SFC OFF THE CST, TEMPS WILL BE AOA NRML
THRU THE EXTENDD PD.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THIS AFTERNOON...VFR CLEAR TO START THEN SCT SC DURING THE AFTN
AOA 6000 FT. NW WIND GUST UNDER 20KT 13Z-18Z THEN WIND
DIMINISHING DURING THE AFTERNOON. COASTAL SEA BREEZES DEVELOPING
THIS AFTERNOON. ONLY MODERATE CONFIDENCE WE WILL SEE WINDS SHIFT
DUE TO SEABREEZE AT ILG AND ACY.
TONIGHT... VFR, WINDS SHIFTING TO NORTHEAST UNDER 10 KNOTS BY
MORNING. SCATTERED AND BROKEN MID-LEVEL CLOUDS.
THURSDAY... CLOUDS BECOMING BROKEN AND LOWERING SOME TO AROUND
5,000 FT THROUGHOUT THE DAY. SOME POTENTIAL FOR LOWERING TO MVFR
CEILINGS LATE IN THE DAY, LOW CONFIDENCE OF MVFR CEILINGS. ANY
SHOWER CHANCE TO SPOTTY FOR TAF MENTION ATTM.
OUTLOOK...
THU NIGHT AND FRI...CEILINGS COULD LOWER TO MVFR OR IFR
ESPECIALLY ACRS THE S AND E AND WOULD MAINLY EFFECT KMIV/KACY
WHERE RAIN IS LIKELY. ITS PSBL THAT KABE/KRDG REMAIN VFR. HOWEVER,
EVEN WHERE THE IS NO RAIN, THERE COULD BE SOME PDS OF LWR CIGS.
BREEZY EASTERLY AND NORTHEASTERLY WIND PSBL LATER THU INTO FRI.
CONFIDENCE VERY LOW.
SAT AND SUN...MOSTLY VFR AS HIGH PRES BUILDS IN AFTER SAT AM. .
MDT CONFIDENCE.
&&
.MARINE...
NO HEADLINES THROUGH TONIGHT.
NW WIND MAY GUST 15 KT AT TIMES THROUGH THIS MORNING THEN SOUTHERLY
SEA AND BAY BREEZES DEVELOP LATER THIS AFTERNOON. LIGHT WIND
TONIGHT BECOMES A LIGHT NORTHEAST DRIFT BY DAYBREAK THURSDAY.
WAVE HEIGHTS AT OR BELOW 2 FT.
OUTLOOK...
THU MORNING...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA.
THU LATE AFTERNOON THROUGH FRI...SCA CONDS EXPECTED AS WINDS GUST
AOA 30 KT AND SIGNIFICANT WAVE HEIGHTS BUILD NEAR 7 FT.
FRI NIGHT INTO SAT...MARGINAL SCA CONDITIONS COULD LINGER THROUGH
SAT MRNG, BUT WINDS AND SEAS SHOULD BE DECREASING.
SAT NIGHT INTO SUN...NO MARINE FLAGS ANTICIPATED.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP INTO THE 25 TO 35
PERCENT RANGE AGAIN THIS AFTERNOON. HOWEVER, WIND SPEEDS AND
GUSTS SHOULD REMAIN LESS THAN 15 MPH, LIMITING THE CONCERN FOR
WILDFIRE SPREAD AT THAT TIME.
&&
.TIDES/COASTAL FLOODING...
WITH THE FULL MOON ON SATURDAY, ASTRONOMICAL HIGH TIDES BY FRIDAY
WILL ALREADY BE NEAR MEAN HIGHER HIGH WATER. THEREFORE, DEPENDING
ON HOW CLOSE THE COASTAL LOW TRACKS TO OUR REGION, THERE IS A
CHANCE FOR MINOR TIDAL FLOODING WITH THE HIGH TIDE CYCLE DURING
THE DAY ON FRIDAY. THIS IS VERY DEPENDENT ON THE TRACK OF THE LOW,
AND AT THIS POINT, THE GFS HAS BEEN TRENDING FURTHER EAST WITH THE
TRACK, CLOSER TO THE ECMWF. THE FURTHER EAST THE TRACK IS, THE
LESS OF AN IMPACT FOR OUR REGION.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DRAG/GAINES
SHORT TERM...DRAG
LONG TERM...NIERENBERG
AVIATION...DRAG/GAINES/NIERENBERG
MARINE...DRAG/NIERENBERG
FIRE WEATHER...DRAG
TIDES/COASTAL FLOODING...NIERENBERG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
925 AM EDT WED APR 29 2015
.SYNOPSIS...
A WEAKENING PRESSURE GRADIENT RESIDES OVER THE REGION TODAY. LOW
PRESSURE OVER THE GULF OF MEXICO WILL MOVE NORTHEASTWARD TO A
POSITION OFF THE SOUTHEASTERN COAST ON THURSDAY. IT WILL CONTINUE
TO TREK NORTHEASTWARD THROUGH THE END OF THE WORK WEEK. HIGH
PRESSURE WILL THEN BUILD IN BEHIND THE DEPARTING LOW FOR THE
WEEKEND AND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ANOTHER WONDERFUL SPRING DAY IN THE PHILLY AREA UNDER A WEAK
RIDGE ALOFT BETWEEN SLOWLY EASTWARD AND SEAWARD DEPARTING WESTERN
ATLANTIC CYCLONIC CIRCULATION AND SOUTHWARD GROWING GREAT LAKES
UPPER LOW. AT THE SFC, WEAK LOW PRESSURE FORMS OVER NNJ THIS
AFTERNOON.
A SUNNY START THEN SCATTERED STRATOCUMULUS THIS AFTERNOON
PROBABLY AOA 6000 FT.
NW WIND GUSTY AROUND 15-20 MPH DURING MID LATE MORNING THEN
SETTLES DOWN A BIT MID AFTERNOON. COASTAL COOLING SEA BREEZES
EXPECTED BUT POSSIBLY NOT WIDESPREAD (00Z/30 ECMWF MUCH MORE
WIDESPREAD THAN THE 00Z/06Z NCEP MODELS). FOLLOWED 09Z HRRR ON
GUSTS THIS MORNING.
THERE IS A MODELED SFC LOW OVER NNJ THAT MAY ASSIST SEA BREEZES
NNJ.
MAX TEMPS ABOUT 5 TO 7 DEGREES ABOVE NORMAL. TEMPERATURES WERE
INCREASED SLIGHTLY WITH THE 9:30 AM UPDATE THROUGHOUT THE DAY
AS A SHARP RISE WITH TEMPERATURES OCCURRED THIS MORNING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
CLEAR TO PARTLY CLOUDY. A COMBINATION OF LEFTOVER STRATOCU THIS
EVENING AND CIRRUS FROM THE SOMEWHAT DEVELOPING SE COAST LOW. THE
CIRRUS MOSTLY THIN, OVERSPREADS LATER AT NIGHT FROM SSW TO NNE.
INVERSION AT 7000 FT MAY TRAP CLOUDS AT THAT LEVEL MOST OF THE
NIGHT. UNCERTAINTY REGARDING CIG TONIGHT.
LOWS 3 OR MORE DEGREES MILDER THAN THE VALUES OF THIS WEDNESDAY
MORNING...ESPECIALLY IF CLOUDS 7000 FT.
LIGHT W-SW WIND PROBABLY TURNS LIGHT NE MOST AREAS BY MORNING.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THU STARTS OUT DRY, WITH LOW PRES OFF THE SERN CONUS CST. THIS
LOW WILL MOVE NEWD THRU FRI, AS THE UPR LOW, NR THE OH VLY SWINGS
SEWD. PRECIP WILL DEVELOP NW OF THE SFC LOW AND PRBLY WITH THE UPR
LOW BUT EXACTLY WHERE REMAINS THE BIG QUESTION. IT STILL APPEARS
THE BEST CHCS OF PRECIP WILL BE OVER SRN AND ERN AREA, BUT THIS
WILL DEPEND ON THE TRACK OF THE LOW. ITS PSBL MOST LOCATIONS MAY
REMAIN DRY THRU THE DAY ON FRI, ESPECIALLY UP NORTH.
THE AXIS OF THE UPR TROF PASSES OFF THE CST FRI EVE AND THIS SHUD
FURTHER STEER THE LOW OUT TO SEA. HIGH PRES WILL BEGIN TO BUILD IN
FROM THE W. BOTH MDLS IMPLY SOME LIGHT PRECIP IN NW FLOW ON SAT.
ITS PSBL, BUT IT WOULD BE LOW POPS.
BEYOND SAT, THE HIGH BUILDS OVER THE REGION FOR MON AND MOVES OFF
THE CST MON NIGHT. THE ECMWF AND CMC HAVE DRY WX DURG THIS TIME
WITH WARM TEMPS AS SWLY FLOW INCREASES. THE GFS, ON THE OTHER HAND
SEEMS TO BE INEXPLICABLY WET AS WE GO MON SUN INTO MON, ESPECIALLY
UNDER HIGH PRES. THEREFORE, AM IGNORING ITS SOLN FOR NOW.
BY MON NIGHT INTO TUE, LOW PRES IN CANADA WILL BRING A CDFNT ACRS
THE NRN REACHES OF THE AREA. SOME PRECIP IS PSBL AND HAVE JUST
GONE WITH SOME LOW POPS. ONCE AGAIN, WHILE THE GFS HAS THE FRONT,
SIMILAR TO THE ECMWF, IT HAS QUITE A BIT MORE PRECIP AND WILL KEEP
THE DRIER TREND.
WITH THE EXCEPTION OF FRI, WHERE THE REGION WILL BE INFLUENCED BY
THE UPR LOW AND PSBLY THE SFC OFF THE CST, TEMPS WILL BE AOA NRML
THRU THE EXTENDD PD.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR CLEAR TO START THEN SCT SC DURING THE AFTN AOA 6000
FT. NW WIND GUST 14KT-20KT 13Z-16Z THEN WIND DIMINISHING DURING
THE AFTERNOON. COASTAL SEA BREEZES DEVELOPING THIS AFTERNOON.
THERE IS MODEL UNCERTAINTY REGARDING THE INLAND PENETRATION OF THE
SEA BREEZE AND AM LESS CONFIDENT OF ANY SSE WIND OCCURRENCE AT
KACY/KILG.
TONIGHT...VFR WITH LEFTOVER SC NEAR 7000-8000 FT TRAPPED IN AN
INVERSION. ALSO SCT-BKN THIN CIRRUS AOA 20000 FEET ARRIVING FROM
SSW TO NNE MAINLY AFTER 06Z/30. LIGHT OR CALM WIND SHOULD TREND NE
BY MORNING.
OUTLOOK...
THU AND FRI...CEILINGS COULD LOWER TO MVFR OR IFR ESPECIALLY ACRS
THE S AND E AND WOULD MAINLY EFFECT KMIV/KACY WHERE RAIN IS
LIKELY. ITS PSBL THAT KABE/KRDG REMAIN VFR. HOWEVER, EVEN WHERE
THE IS NO RAIN, THERE COULD BE SOME PDS OF LWR CIGS. BREEZY
EASTERLY AND NORTHEASTERLY WIND PSBL LATER THU INTO FRI.
CONFIDENCE VERY LOW.
SAT AND SUN...MOSTLY VFR AS HIGH PRES BUILDS IN AFTER SAT AM. .
MDT CONFIDENCE.
&&
.MARINE...
NO HEADLINES THROUGH TONIGHT.
NW WIND MAY GUST 15 KT AT TIMES THROUGH THIS MORNING THEN SOUTHERLY
SEA AND BAY BREEZES DEVELOP LATER THIS AFTERNOON. LIGHT WIND
TONIGHT BECOMES A LIGHT NORTHEAST DRIFT BY DAYBREAK THURSDAY.
WAVE HEIGHTS AT OR BELOW 2 FT.
OUTLOOK...
THU MORNING...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA.
THU LATE AFTERNOON THROUGH FRI...SCA CONDS EXPECTED AS WINDS GUST
AOA 30 KT AND SIGNIFICANT WAVE HEIGHTS BUILD NEAR 7 FT.
FRI NIGHT INTO SAT...MARGINAL SCA CONDITIONS COULD LINGER THROUGH
SAT MRNG, BUT WINDS AND SEAS SHOULD BE DECREASING.
SAT NIGHT INTO SUN...NO MARINE FLAGS ANTICIPATED.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP INTO THE 25 TO 35
PERCENT RANGE AGAIN THIS AFTERNOON. HOWEVER, WIND SPEEDS AND
GUSTS SHOULD REMAIN LESS THAN 15 MPH, LIMITING THE CONCERN FOR
WILDFIRE SPREAD AT THAT TIME.
&&
.TIDES/COASTAL FLOODING...
WITH THE FULL MOON ON SATURDAY, ASTRONOMICAL HIGH TIDES BY FRIDAY
WILL ALREADY BE NEAR MEAN HIGHER HIGH WATER. THEREFORE, DEPENDING
ON HOW CLOSE THE COASTAL LOW TRACKS TO OUR REGION, THERE IS A
CHANCE FOR MINOR TIDAL FLOODING WITH THE HIGH TIDE CYCLE DURING
THE DAY ON FRIDAY. THIS IS VERY DEPENDENT ON THE TRACK OF THE LOW,
AND AT THIS POINT, THE GFS HAS BEEN TRENDING FURTHER EAST WITH THE
TRACK, CLOSER TO THE ECMWF. THE FURTHER EAST THE TRACK IS, THE
LESS OF AN IMPACT FOR OUR REGION.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DRAG/GAINES
SHORT TERM...DRAG
LONG TERM...NIERENBERG
AVIATION...DRAG/NIERENBERG
MARINE...DRAG/NIERENBERG
FIRE WEATHER...DRAG
TIDES/COASTAL FLOODING...NIERENBERG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
655 AM EDT WED APR 29 2015
.SYNOPSIS...
A WEAKENING PRESSURE GRADIENT RESIDES OVER THE REGION TODAY. LOW
PRESSURE OVER THE GULF OF MEXICO WILL MOVE NORTHEASTWARD TO A
POSITION OFF THE SOUTHEASTERN COAST ON THURSDAY. IT WILL CONTINUE
TO TREK NORTHEASTWARD THROUGH THE END OF THE WORK WEEK. HIGH
PRESSURE WILL THEN BUILD IN BEHIND THE DEPARTING LOW FOR THE
WEEKEND AND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ANOTHER WONDERFUL SPRING DAY IN THE PHILLY AREA UNDER A WEAK
RIDGE ALOFT BETWEEN SLOWLY EASTWARD AND SEAWARD DEPARTING WESTERN
ATLANTIC CYCLONIC CIRCULATION AND SOUTHWARD GROWING GREAT LAKES
UPPER LOW. AT THE SFC, WEAK LOW PRESSURE FORMS OVER NNJ THIS
AFTERNOON.
A SUNNY START THEN SCATTERED STRATOCUMULUS THIS AFTERNOON
PROBABLY AOA 6000 FT.
NW WIND GUSTY AROUND 15-20 MPH DURING MID LATE MORNING THEN
SETTLES DOWN A BIT MID AFTERNOON. COASTAL COOLING SEA BREEZES
EXPECTED BUT POSSIBLY NOT WIDESPREAD (00Z/30 ECMWF MUCH MORE
WIDESPREAD THAN THE 00Z/06Z NCEP MODELS). FOLLOWED 09Z HRRR ON
GUSTS THIS MORNING.
THERE IS A MODELED SFC LOW OVER NNJ THAT MAY ASSIST SEA BREEZES
NNJ.
MAX TEMPS ABOUT 5 TO 7 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
CLEAR TO PARTLY CLOUDY. A COMBINATION OF LEFTOVER STRATOCU THIS
EVENING AND CIRRUS FROM THE SOMEWHAT DEVELOPING SE COAST LOW. THE
CIRRUS MOSTLY THIN, OVERSPREADS LATER AT NIGHT FROM SSW TO NNE.
INVERSION AT 7000 FT MAY TRAP CLOUDS AT THAT LEVEL MOST OF THE
NIGHT. UNCERTAINTY REGARDING CIG TONIGHT.
LOWS 3 OR MORE DEGREES MILDER THAN THE VALUES OF THIS WEDNESDAY
MORNING...ESPECIALLY IF CLOUDS 7000 FT.
LIGHT W-SW WIND PROBABLY TURNS LIGHT NE MOST AREAS BY MORNING.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THU STARTS OUT DRY, WITH LOW PRES OFF THE SERN CONUS CST. THIS
LOW WILL MOVE NEWD THRU FRI, AS THE UPR LOW, NR THE OH VLY SWINGS
SEWD. PRECIP WILL DEVELOP NW OF THE SFC LOW AND PRBLY WITH THE UPR
LOW BUT EXACTLY WHERE REMAINS THE BIG QUESTION. IT STILL APPEARS
THE BEST CHCS OF PRECIP WILL BE OVER SRN AND ERN AREA, BUT THIS
WILL DEPEND ON THE TRACK OF THE LOW. ITS PSBL MOST LOCATIONS MAY
REMAIN DRY THRU THE DAY ON FRI, ESPECIALLY UP NORTH.
THE AXIS OF THE UPR TROF PASSES OFF THE CST FRI EVE AND THIS SHUD
FURTHER STEER THE LOW OUT TO SEA. HIGH PRES WILL BEGIN TO BUILD IN
FROM THE W. BOTH MDLS IMPLY SOME LIGHT PRECIP IN NW FLOW ON SAT.
ITS PSBL, BUT IT WOULD BE LOW POPS.
BEYOND SAT, THE HIGH BUILDS OVER THE REGION FOR MON AND MOVES OFF
THE CST MON NIGHT. THE ECMWF AND CMC HAVE DRY WX DURG THIS TIME
WITH WARM TEMPS AS SWLY FLOW INCREASES. THE GFS, ON THE OTHER HAND
SEEMS TO BE INEXPLICABLY WET AS WE GO MON SUN INTO MON, ESPECIALLY
UNDER HIGH PRES. THEREFORE, AM IGNORING ITS SOLN FOR NOW.
BY MON NIGHT INTO TUE, LOW PRES IN CANADA WILL BRING A CDFNT ACRS
THE NRN REACHES OF THE AREA. SOME PRECIP IS PSBL AND HAVE JUST
GONE WITH SOME LOW POPS. ONCE AGAIN, WHILE THE GFS HAS THE FRONT,
SIMILAR TO THE ECMWF, IT HAS QUITE A BIT MORE PRECIP AND WILL KEEP
THE DRIER TREND.
WITH THE EXCEPTION OF FRI, WHERE THE REGION WILL BE INFLUENCED BY
THE UPR LOW AND PSBLY THE SFC OFF THE CST, TEMPS WILL BE AOA NRML
THRU THE EXTENDD PD.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR CLEAR TO START THEN SCT SC DURING THE AFTN AOA 6000
FT. NW WIND GUST 14KT-20KT 13Z-16Z THEN WIND DIMINISHING DURING
THE AFTERNOON. COASTAL SEA BREEZES DEVELOPING THIS AFTERNOON.
THERE IS MODEL UNCERTAINTY REGARDING THE INLAND PENETRATION OF THE
SEA BREEZE AND AM LESS CONFIDENT OF ANY SSE WIND OCCURRENCE AT
KACY/KILG.
TONIGHT...VFR WITH LEFTOVER SC NEAR 7000-8000 FT TRAPPED IN AN
INVERSION. ALSO SCT-BKN THIN CIRRUS AOA 20000 FEET ARRIVING FROM
SSW TO NNE MAINLY AFTER 06Z/30. LIGHT OR CALM WIND SHOULD TREND NE
BY MORNING.
OUTLOOK...
THU AND FRI...CEILINGS COULD LOWER TO MVFR OR IFR ESPECIALLY ACRS
THE S AND E AND WOULD MAINLY EFFECT KMIV/KACY WHERE RAIN IS
LIKELY. ITS PSBL THAT KABE/KRDG REMAIN VFR. HOWEVER, EVEN WHERE
THE IS NO RAIN, THERE COULD BE SOME PDS OF LWR CIGS. BREEZY
EASTERLY AND NORTHEASTERLY WIND PSBL LATER THU INTO FRI.
CONFIDENCE VERY LOW.
SAT AND SUN...MOSTLY VFR AS HIGH PRES BUILDS IN AFTER SAT AM. .
MDT CONFIDENCE.
&&
.MARINE...
NO HEADLINES THROUGH TONIGHT.
NW WIND MAY GUST 15 KT AT TIMES THROUGH THIS MORNING THEN SOUTHERLY
SEA AND BAY BREEZES DEVELOP LATER THIS AFTERNOON. LIGHT WIND
TONIGHT BECOMES A LIGHT NORTHEAST DRIFT BY DAYBREAK THURSDAY.
WAVE HEIGHTS AT OR BELOW 2 FT.
OUTLOOK...
THU MORNING...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA.
THU LATE AFTERNOON THROUGH FRI...SCA CONDS EXPECTED AS WINDS GUST
AOA 30 KT AND SIGNIFICANT WAVE HEIGHTS BUILD NEAR 7 FT.
FRI NIGHT INTO SAT...MARGINAL SCA CONDITIONS COULD LINGER THROUGH
SAT MRNG, BUT WINDS AND SEAS SHOULD BE DECREASING.
SAT NIGHT INTO SUN...NO MARINE FLAGS ANTICIPATED.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP INTO THE 25 TO 35
PERCENT RANGE AGAIN THIS AFTERNOON. HOWEVER, WIND SPEEDS AND
GUSTS SHOULD REMAIN LESS THAN 15 MPH, LIMITING THE CONCERN FOR
WILDFIRE SPREAD AT THAT TIME.
&&
.TIDES/COASTAL FLOODING...
WITH THE FULL MOON ON SATURDAY, ASTRONOMICAL HIGH TIDES BY FRIDAY
WILL ALREADY BE NEAR MEAN HIGHER HIGH WATER. THEREFORE, DEPENDING
ON HOW CLOSE THE COASTAL LOW TRACKS TO OUR REGION, THERE IS A
CHANCE FOR MINOR TIDAL FLOODING WITH THE HIGH TIDE CYCLE DURING
THE DAY ON FRIDAY. THIS IS VERY DEPENDENT ON THE TRACK OF THE LOW,
AND AT THIS POINT, THE GFS HAS BEEN TRENDING FURTHER EAST WITH THE
TRACK, CLOSER TO THE ECMWF. THE FURTHER EAST THE TRACK IS, THE
LESS OF AN IMPACT FOR OUR REGION.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DRAG 655A
SHORT TERM...DRAG 655A
LONG TERM...NIERENBERG
AVIATION...DRAG/NIERENBERG 655A
MARINE...DRAG/NIERENBERG 655A
FIRE WEATHER...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MIAMI FL
252 PM EDT WED APR 29 2015
.DISCUSSION...
MAIN CONCERN THIS AFTERNOON IS THE POTENTIAL FOR ADDITIONAL
CONVECTION OUT AHEAD OF AN APPROACHING COLD FRONT. LATEST VISIBLE
SATELLITE STILL SHOWS QUITE A BIT OF DEBRIS CLOUDINESS ACROSS
VIRTUALLY ALL OF SOUTH FLORIDA. POCKETS OF CLEARING HAVE SHOWN
BRIEFLY ACROSS THE LAKE OKEECHOBEE AREA WHERE ARE A FEW SHOWERS
HAVE DEVELOPED. THE DEBRIS CLOUDS ARE THE RESULT OF CONTINUING
CONVECTION ACROSS THE KEYS DUE TO A WEAK SURFACE TROUGH. THE COLD
FRONT IS STILL PROGGED TO PUSH THROUGH THE AREA LATER THIS EVENING
WITH A SLIGHT POSSIBILITY OF ADDITIONAL ORGANIZED SHOWERS AND
THUNDERSTORMS OUT AHEAD OF IT...BUT THE THREAT IS LOOKING LESS
LIKELY. THE LATEST HRRR WHICH HAS INITIALIZED WELL THROUGH THE
MORNING KEEPS THE AREA NEARLY RAIN FREE LATER THIS EVENING.
THE AFOREMENTIONED COLD FRONT SHOULD THEN CLEAR THE AREA OVERNIGHT
TONIGHT AND INTO THURSDAY TAKING VIRTUALLY ALL OF THE PRECIPITATION
WITH IT. BY FRIDAY MORNING...ANOTHER COLD BUT DRY FRONT WILL
SURGE INTO SOUTH FLORIDA FROM THE NORTH AS AN H5 TROUGH IS STILL
EXPECTED TO DIG SOUTH AND INTO THE CAROLINAS. THIS WILL BRING A
MUCH COOLER AND DRIER AIR MASS INTO THE AREA FOR FRIDAY THROUGH
SATURDAY. MOST MODEL BLENDS ARE DEPICTING DEWPOINTS IN THE UPPER
50S ACROSS THE EAST COAST METRO AREAS FRIDAY INTO SATURDAY WHICH
WILL MAKE FOR VERY PLEASANT CONDITIONS.
HIGH PRESSURE BEHIND THE DRY FRONT IS THEN EXPECTED TO QUICKLY PUSH
TO THE EAST AND INTO THE WESTERN ATLANTIC. THIS WILL ALLOW FOR A
MORE EASTERLY FLOW REGIME TO PREVAIL SUNDAY THROUGH MONDAY. DEEPER
MOISTURE WILL THEN RETURN FOR THE FIRST PART OF NEXT WEEK AS MODELS
DEPICT AN AREA OF LOW PRESSURE DEVELOPING ACROSS THE YUCATAN CHANNEL
AND PUSHING TO THE NORTHEAST AND TOWARD THE BAHAMAS. THIS WILL
RETURN DECENT CHANCES FOR SHOWERS AND POSSIBLE THUNDERSTORMS THROUGH
MIDWEEK.
&&
.AVIATION...
CLOUDS ARE STILL DRIFTING FROM THE GULF OF MEXICO INTO THE
SOUTHERN PORTIONS OF THE CWA. VCSH IS INCLUDED FOR ALL AIRPORTS
UNTIL 00Z APR 30. WINDS WILL SHIFT FROM 220 TO 280 AS THE FRONT
CONTINUES TO APPROACH FROM THE WEST. THE CLOUD COVER IS NOT
ALLOWING FOR SURFACE HEATING. WITHOUT SURFACE HEATING AND THE
LOW LEVEL COOLING FROM THE RAINS EARLIER, THUNDERSTORMS ARE NOT
VERY LIKELY THIS EVENING. HOWEVER, WE WILL AMEND THE TAFS AS
NEEDED.
&&
.MARINE...
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS WILL CONTINUE TO AFFECT
THE ATLANTIC WATERS OF BROWARD AND MIAMI-DADE COUNTY THIS
AFTERNOON. SOUTHWESTERLY WINDS AHEAD OF A COLD FRONT WILL INCREASE
ACROSS THE ATLANTIC WATERS TO NEAR SCA CRITERIA...WILL HOLD OFF
FOR NOW AND COVER WITH SCEC. WINDS WILL THEN TURN MORE NORTHWEST
OVERNIGHT AND INTO THURSDAY AS THE COLD FRONT PUSHES THROUGH THE
AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 85 65 86 / 10 10 0 10
FORT LAUDERDALE 73 86 68 88 / 20 20 0 10
MIAMI 72 85 66 87 / 20 20 0 10
NAPLES 73 82 68 83 / 20 10 0 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...10/CD
LONG TERM....10/CD
AVIATION...71/JE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
243 PM CDT WED APR 29 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 243 PM CDT WED APR 29 2015
AN UPPER LEVEL LOW WAS OVER EASTERN LAKE SUPERIOR THIS AFTERNOON
WITH ANOTHER UPPER LEVEL LOW OVER SOUTHEAST MO. THE UPPER LEVEL
LOW OVER EASTERN LAKE SUPERIOR WILL TRACK SOUTHWARD INTO EAST
CENTRAL INDIANA BY NOON THU AND TO BE THE DOMINANT WEATHER SYSTEM
TO AFFECT CENTRAL/SE IL NEXT 24 HOURS ESPECIALLY EASTERN IL.
SCATTERED TO BROKEN HIGH BASED CUMULUS CLOUDS 7-9K FT WEST OF
HIGHWAY 51 WILL CONTINUE TO INCREASE OVER EASTERN IL REST OF
TODAY. AS NEXT SHORT WAVE DROPS SOUTHWARD, SHORT RANGE MODELS LIKE
HRRR AND RAP DEVELOP ISOLATED CONVECTION OVER CENTRAL IL LATE THIS
AFTERNOON AND EARLY EVENING AND SHIFT IT SE LATER THIS EVENING AND
OVERNIGHT. CONTINUE 20-30% CHANCES OF SHOWERS THIS EVENING
(ISOLATED THUNDER NORTH OF I- 72 UNTIL SUNSET) AND ISOLATED
SHOWERS EAST OF I-55 OVERNIGHT. LACK OF MOISTURE WILL KEEP
RAINFALL AMOUNTS LIGHT (LESS THAN A TENTH INCH) IF THEY HAPPEN.
LOWS OVERNIGHT RANGE FROM LOWER 40S FROM LINCOLN NORTH TO THE
UPPER 40S SE OF I-70. NNE WINDS OF 5-10 MPH TONIGHT WITH NO FOG
EXPECTED TONIGHT.
&&
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 243 PM CDT WED APR 29 2015
UPPER LEVEL LOW WILL CONTINUE TO TRACK SOUTH, EAST OF THE AREA,
WHICH WILL KEEP THE SURFACE RIDGE TO THE WEST OF THE CWA THURSDAY,
KEEPING US WITH NORTHERLY SURFACE WINDS. WILL KEEP A SLIGHT CHANCE
OF ISOLATED SHOWERS IN THE EAST FOR THURSDAY AS THE UPPER LOW MOVES
SOUTH. ONCE THAT PASSES THURSDAY EVENING DRY WEATHER IS EXPECTED
BEGINNING FRIDAY. THE HIGH PRESSURE RIDGE WILL THEN MOVE ACROSS THE
AREA FRIDAY WITH DRY WEATHER AND LIGHT WINDS. THIS RIDGE WILL DROP
SOUTH OF THE AREA FRIDAY NIGHT AND REMAIN THERE FOR SATURDAY.
HOWEVER, NORTHWEST FLOW WILL REMAIN OVER THE AREA INTO THE
WEEKEND. A COUPLE OF WEAK WAVES WILL MOVE SOUTHEAST THROUGH THE
NORTHWEST FLOW. ANY PCPN ASSOCIATED WITH THESE WAVES SHOULD REMAIN
WEST OF THE AREA AT LEAST THROUGH SATURDAY.
TEMPS THROUGH THE PERIOD WILL RANGE FROM AROUND NORMAL FOR THURSDAY
TO ABOVE NORMAL FOR FRIDAY AND SATURDAY.
THE HIGH PRESSURE RIDGE WILL SLIDE INTO THE SOUTHEAST US BY SATURDAY
NIGHT, WHICH WILL ALLOW THE UPPER LEVEL FLOW TO BEGIN TO TRANSITION
TO A MORE ZONAL PATTER FOR THE WEEKEND. THIS WILL ALSO ALLOW
SOUTHERLY WINDS TO RETURN TO THE CWA, BRINGING AN INCREASE IN
MOISTURE AND TEMPERATURES. IN ADDITION, ANY PCPN ASSOCIATED WITH
ADDITIONAL WEAK MID LEVEL WAVES WILL HOLD TOGETHER LONGER AND BE
ABLE TO REACH INTO THE CWA. SO WILL KEEP THE POPS IN THE FORECAST
BEGINNING SATURDAY NIGHT AND CONTINUING THROUGH THE WEEKEND AND INTO
NEXT WEEK. WITH THE FLOW BECOMING ZONAL ANY SURFACE FRONT WILL
BECOME SOMEWHAT STATIONARY OVER THE MIDDLE OF THE CWA THROUGH THE
FIRST PART OF THE WEEK. WITH THE INCREASED MOISTURE, IT LOOKS LIKE
LIKELY POPS IS WARRANTED FOR THE NORTHERN PARTS OF THE CWA, WITH
CHANCE POPS TO THE SOUTH, AND EITHER NO POPS OR SLIGHT CHANCE POPS
IN THE SOUTHEAST.
TEMPS WILL BECOME WARMER, ESPECIALLY IN THE SOUTHERN HALF OF THE
CWA, WHICH SHOULD BE SOUTH OF THE STATIONARY FRONT THROUGH PART OF
THE WEEK. ABOVE NORMAL TEMPS CAN BE EXPECTED WITH THIS PATTERN.
BELIEVE GUIDANCE IS A LITTLE ON THE WARM SIDE FOR DAYTIME HIGHS,
ESPECIALLY IN AREAS WHERE THERE WILL BE PCPN AND CLOUDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1259 PM CDT WED APR 29 2015
VFR CONDITIONS ARE FORECAST TO CONTINUE ACROSS THE CENTRAL IL
AIRPORTS NEXT 24 HOURS THROUGH 18Z/1 PM THU. SCATTERED TO BROKEN
CLOUDS FROM 5-10K FT WILL DEVELOP DURING THE AFTERNOON AND
CONTINUE THIS EVENING DUE TO UPPER LEVEL TROF FROM EASTERN LAKE
SUPERIOR SOUTHWARD TO SOUTHEAST MO. CONTINUED VCSH SHOWERS LATE
AFTERNOON AND EVENING WITH THIS TROF AND ISOLATED THUNDER POSSIBLE
MAINLY NORTH OF PIA FROM 21Z-01Z. VFR CLOUDS TO DECREASE OVERNIGHT
AND LINGER LONGEST AT CMI. CUTOFF UPPER LEVEL LOW DROPPING
SOUTHWARD FROM EASTERN LAKE SUPERIOR INTO EAST CENTRAL INDIANA BY
18Z THU WILL KEEP MORE VFR CLOUDS 5-10K FT OVER EASTERN IL THU.
NNE WINDS AROUND 10 KTS THIS AFTERNOON TO DIMINISH TO 4-8 KTS
TONIGHT AND PICK BACK UP TO 9-14 KTS BY 15Z/10 AM THU AS DIURNAL
CYCLE INCREASES WINDS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...AUTEN
AVIATION...07
AREA FORECAST DISCUSSION
NWS JACKSON KY
1041 PM EDT THU APR 30 2015
.UPDATE...
ISSUED AT 1041 PM EDT THU APR 30 2015
MUCH OF THE SHOWER AND THUNDERSTORM ACTIVITY SEEN EARLIER HAS
MOSTLY COME TO A END TONIGHT GIVEN LOSS OF DAYTIME HEATING. THERE
CONTINUES TO BE SOME ISOLATED POCKETS OF LIGHT
RAIN/DRIZZLE SEEN ON RADAR AND PICKUP BY ASOS...OTHERWISE MOST
SPOTS ARE SEEING MOSTLY TO PARTLY CLOUDY SKIES TONIGHT. THE
FORECAST CHALLENGE TONIGHT WILL BE THE STRATUS ACROSS OHIO/WV
POTENTIALLY SWINGING THROUGH THE REGION OVERNIGHT AND HOW FAR WEST
DOES THAT STRETCH. RIGHT NOW WILL STICK CLOSE TO FORECASTED SKY
COVER AND ALLOW FOR CLOSER LOOK AT LATEST MODEL DATA. UPDATED
GRIDS WITH LATEST OBS AND TRENDS WITH NO MAJOR CHANGES NEEDED THIS
UPDATE.
UPDATE ISSUED AT 810 PM EDT THU APR 30 2015
SHOWERS AND SOME ISOLATED STORMS CONTINUE TO MOVE SOUTHEAST ACROSS
PORTIONS OF EASTERN KENTUCKY THIS EVENING. THIS HAS BEEN DRIVEN BY
UPPER LEVEL LOW SWINGING SOUTH OUT OF THE GREAT LAKES TODAY.
LOOKING AT THE MESO MODELS AND WATER VAPOR IMAGERY THIS LOW IS
SUGGESTED TO BE CENTERED JUST TO OUR NORTH ACROSS NORTHERN
KENTUCKY. MUCH OF THIS SHOWER AND STORM ACTIVITY HAS CONTINUED TO
DECREASE IN INTENSITY AS WE LOOSE THE DAYTIME HEATING. SOME OF THE
STRONGER STORMS STILL HAVE THE POTENTIAL TO PRODUCE SOME SMALL
HAIL AND BRIEF GUSTY WINDS. OTHERWISE UPDATED GRIDS WITH THE
LATEST OBS AND TRENDS INCLUDING RADAR. THIS DID LEAD TO KEEPING
THE POPS UP FOR A BIT LONGER IN THE AREAS THAT CONTINUE TO SEE
SHOWERS EARLY THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM EDT THU APR 30 2015
A DEEP UPPER LEVEL LOW CONTINUES TO SPIN ACROSS THE OHIO RIVER
VALLEY REGION THIS AFTERNOON...WITH NUMEROUS SHOWERS AND
THUNDERSTORMS CONTINUING TO DEVELOP AND PUSH SOUTH ACROSS PORTIONS
OF EASTERN KENTUCKY. CONTINUING TO RECEIVE MULTIPLE REPORTS OF
SMALL HAIL AND THIS TREND SHOULD CONTINUE INTO THE EVENING HOURS
WITH FREEZING LEVELS AROUND 5500 FEET. ACTIVITY SHOULD WEAKEN OR
DIMINISH BY LATE THIS EVENING WITH THE LOSS OF DAYTIME
INSTABILITY. A FEW SHOWERS MAY PERSIST OVERNIGHT...BUT THESE
SHOULD BE FEW AND FAR BETWEEN. THUS...WILL KEEP JUST A SMALL
CHANCE OF RAIN GOING THROUGH DAYBREAK FRIDAY. UPPER LEVEL LOW
SHOULD MOVE FAR ENOUGH EAST BY LATE FRIDAY MORNING TO KEEP THE
AREA DRY THROUGH THE REMAINDER OF THE DAY...WE MAY KEEP SOME
CLOUDS AROUND THROUGH THE DAY GIVEN NO STRONG PUNCH OF DRY AIR OR
RIDGING. CLOUDS SHOULD FINALLY ERODE FRIDAY NIGHT AS RIDGING
BUILDS OVER THE REGION. THE AREA WILL STAY COOL THROUGH FRIDAY
NIGHT AS WE CONTINUE TO BE INFLUENCED BY THE CLOUD COVER AND UPPER
LEVEL LOW.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 417 PM EDT THU APR 30 2015
AN OVERALL QUIET STRETCH OF TIME IS IN STORE. AN EASTERN CONUS
UPPER TROUGH WILL BE IN THE PROCESS OF MOVING OUT TO THE EAST AS
THE PERIOD STARTS. A SHORTWAVE TROUGH DROPPING INTO THE LARGE
SCALE TROUGH IS EXPECTED TO MOVE THROUGH ON SATURDAY AFTERNOON.
FORECAST SOUNDINGS LOOK VERY MARGINAL FOR ANY PRECIP WITH THE
FEATURE...AND HAVE ONLY INCLUDED A POSSIBILITY OF SPRINKLES. AFTER
THIS...GEOPOTENTIAL HEIGHTS RISE AND UPPER LEVEL RIDGING BUILDS
IN THROUGH THE MIDDLE OF THE WEEK. THIS SHOULD BRING MAINLY DRY
WEATHER AND GRADUALLY INCREASING TEMPERATURES. MODELS DO GENERATE
A BIT OF LIGHT PRECIP AT TIMES IN A DIURNAL PATTERN WITH DAYTIME
HEATING...ESPECIALLY THE GFS. SOUNDINGS DO NOT LOOK ALL THAT
FAVORABLE FOR PRECIP...AND HAVE OPTED TO KEEP POPS SUB-20 PERCENT
IN THE FORECAST AREA UNTIL THURSDAY. BY THEN...LOW LEVEL MOISTURE
COULD PERHAPS RECOVER ENOUGH FOR ISOLATED THUNDERSTORMS TO
DEVELOP.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 740 PM EDT THU APR 30 2015
MOST SITES ARE KEEPING IN THE VFR RANGE THIS AFTERNOON AND
EVENING...HOWEVER THOSE SITES THAT DO SEE SHOWERS AND ISOLATED
STORMS COULD SEE BRIEF DROPS TO MVFR/IFR. THESE SHOWERS AND
ISOLATED STORMS HAVE BEEN SLOWLY DIEING THIS EVENING AND BASED ON
THE HRRR THIS WOULD BE THE TREND THROUGH EVENING. THEN WE TURN TO
THE POSSIBILITY OF A STATUS DECK OVERNIGHT AND HAVE GIVEN MOST
SITES A BKN MVFR DECK OVERNIGHT GIVEN THE LOWER CONFIDENCE. WINDS
THROUGH THE PERIOD WILL GENERALLY BE LIGHT AND VRB...UNLESS YOU
GET CLOSER TO A STORM OR OUTFLOW IN THE EARLY EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...KAS
LONG TERM...HAL
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
810 PM EDT THU APR 30 2015
.UPDATE...
ISSUED AT 810 PM EDT THU APR 30 2015
SHOWERS AND SOME ISOLATED STORMS CONTINUE TO MOVE SOUTHEAST ACROSS
PORTIONS OF EASTERN KENTUCKY THIS EVENING. THIS HAS BEEN DRIVEN BY
UPPER LEVEL LOW SWINGING SOUTH OUT OF THE GREAT LAKES TODAY.
LOOKING AT THE MESO MODELS AND WATER VAPOR IMAGERY THIS LOW IS
SUGGESTED TO BE CENTERED JUST TO OUR NORTH ACROSS NORTHERN
KENTUCKY. MUCH OF THIS SHOWER AND STORM ACTIVITY HAS CONTINUED TO
DECREASE IN INTENSITY AS WE LOOSE THE DAYTIME HEATING. SOME OF THE
STRONGER STORMS STILL HAVE THE POTENTIAL TO PRODUCE SOME SMALL
HAIL AND BRIEF GUSTY WINDS. OTHERWISE UPDATED GRIDS WITH THE
LATEST OBS AND TRENDS INCLUDING RADAR. THIS DID LEAD TO KEEPING
THE POPS UP FOR A BIT LONGER IN THE AREAS THAT CONTINUE TO SEE
SHOWERS EARLY THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM EDT THU APR 30 2015
A DEEP UPPER LEVEL LOW CONTINUES TO SPIN ACROSS THE OHIO RIVER
VALLEY REGION THIS AFTERNOON...WITH NUMEROUS SHOWERS AND
THUNDERSTORMS CONTINUING TO DEVELOP AND PUSH SOUTH ACROSS PORTIONS
OF EASTERN KENTUCKY. CONTINUING TO RECEIVE MULTIPLE REPORTS OF
SMALL HAIL AND THIS TREND SHOULD CONTINUE INTO THE EVENING HOURS
WITH FREEZING LEVELS AROUND 5500 FEET. ACTIVITY SHOULD WEAKEN OR
DIMINISH BY LATE THIS EVENING WITH THE LOSS OF DAYTIME
INSTABILITY. A FEW SHOWERS MAY PERSIST OVERNIGHT...BUT THESE
SHOULD BE FEW AND FAR BETWEEN. THUS...WILL KEEP JUST A SMALL
CHANCE OF RAIN GOING THROUGH DAYBREAK FRIDAY. UPPER LEVEL LOW
SHOULD MOVE FAR ENOUGH EAST BY LATE FRIDAY MORNING TO KEEP THE
AREA DRY THROUGH THE REMAINDER OF THE DAY...WE MAY KEEP SOME
CLOUDS AROUND THROUGH THE DAY GIVEN NO STRONG PUNCH OF DRY AIR OR
RIDGING. CLOUDS SHOULD FINALLY ERODE FRIDAY NIGHT AS RIDGING
BUILDS OVER THE REGION. THE AREA WILL STAY COOL THROUGH FRIDAY
NIGHT AS WE CONTINUE TO BE INFLUENCED BY THE CLOUD COVER AND UPPER
LEVEL LOW.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 417 PM EDT THU APR 30 2015
AN OVERALL QUIET STRETCH OF TIME IS IN STORE. AN EASTERN CONUS
UPPER TROUGH WILL BE IN THE PROCESS OF MOVING OUT TO THE EAST AS
THE PERIOD STARTS. A SHORTWAVE TROUGH DROPPING INTO THE LARGE
SCALE TROUGH IS EXPECTED TO MOVE THROUGH ON SATURDAY AFTERNOON.
FORECAST SOUNDINGS LOOK VERY MARGINAL FOR ANY PRECIP WITH THE
FEATURE...AND HAVE ONLY INCLUDED A POSSIBILITY OF SPRINKLES. AFTER
THIS...GEOPOTENTIAL HEIGHTS RISE AND UPPER LEVEL RIDGING BUILDS
IN THROUGH THE MIDDLE OF THE WEEK. THIS SHOULD BRING MAINLY DRY
WEATHER AND GRADUALLY INCREASING TEMPERATURES. MODELS DO GENERATE
A BIT OF LIGHT PRECIP AT TIMES IN A DIURNAL PATTERN WITH DAYTIME
HEATING...ESPECIALLY THE GFS. SOUNDINGS DO NOT LOOK ALL THAT
FAVORABLE FOR PRECIP...AND HAVE OPTED TO KEEP POPS SUB-20 PERCENT
IN THE FORECAST AREA UNTIL THURSDAY. BY THEN...LOW LEVEL MOISTURE
COULD PERHAPS RECOVER ENOUGH FOR ISOLATED THUNDERSTORMS TO
DEVELOP.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 740 PM EDT THU APR 30 2015
MOST SITES ARE KEEPING IN THE VFR RANGE THIS AFTERNOON AND
EVENING...HOWEVER THOSE SITES THAT DO SEE SHOWERS AND ISOLATED
STORMS COULD SEE BRIEF DROPS TO MVFR/IFR. THESE SHOWERS AND
ISOLATED STORMS HAVE BEEN SLOWLY DIEING THIS EVENING AND BASED ON
THE HRRR THIS WOULD BE THE TREND THROUGH EVENING. THEN WE TURN TO
THE POSSIBILITY OF A STATUS DECK OVERNIGHT AND HAVE GIVEN MOST
SITES A BKN MVFR DECK OVERNIGHT GIVEN THE LOWER CONFIDENCE. WINDS
THROUGH THE PERIOD WILL GENERALLY BE LIGHT AND VRB...UNLESS YOU
GET CLOSER TO A STORM OR OUTFLOW IN THE EARLY EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...KAS
LONG TERM...HAL
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
741 PM EDT THU APR 30 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM EDT THU APR 30 2015
A DEEP UPPER LEVEL LOW CONTINUES TO SPIN ACROSS THE OHIO RIVER
VALLEY REGION THIS AFTERNOON...WITH NUMEROUS SHOWERS AND
THUNDERSTORMS CONTINUING TO DEVELOP AND PUSH SOUTH ACROSS PORTIONS
OF EASTERN KENTUCKY. CONTINUING TO RECEIVE MULTIPLE REPORTS OF
SMALL HAIL AND THIS TREND SHOULD CONTINUE INTO THE EVENING HOURS
WITH FREEZING LEVELS AROUND 5500 FEET. ACTIVITY SHOULD WEAKEN OR
DIMINISH BY LATE THIS EVENING WITH THE LOSS OF DAYTIME
INSTABILITY. A FEW SHOWERS MAY PERSIST OVERNIGHT...BUT THESE
SHOULD BE FEW AND FAR BETWEEN. THUS...WILL KEEP JUST A SMALL
CHANCE OF RAIN GOING THROUGH DAYBREAK FRIDAY. UPPER LEVEL LOW
SHOULD MOVE FAR ENOUGH EAST BY LATE FRIDAY MORNING TO KEEP THE
AREA DRY THROUGH THE REMAINDER OF THE DAY...WE MAY KEEP SOME
CLOUDS AROUND THROUGH THE DAY GIVEN NO STRONG PUNCH OF DRY AIR OR
RIDGING. CLOUDS SHOULD FINALLY ERODE FRIDAY NIGHT AS RIDGING
BUILDS OVER THE REGION. THE AREA WILL STAY COOL THROUGH FRIDAY
NIGHT AS WE CONTINUE TO BE INFLUENCED BY THE CLOUD COVER AND UPPER
LEVEL LOW.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 417 PM EDT THU APR 30 2015
AN OVERALL QUIET STRETCH OF TIME IS IN STORE. AN EASTERN CONUS
UPPER TROUGH WILL BE IN THE PROCESS OF MOVING OUT TO THE EAST AS
THE PERIOD STARTS. A SHORTWAVE TROUGH DROPPING INTO THE LARGE
SCALE TROUGH IS EXPECTED TO MOVE THROUGH ON SATURDAY AFTERNOON.
FORECAST SOUNDINGS LOOK VERY MARGINAL FOR ANY PRECIP WITH THE
FEATURE...AND HAVE ONLY INCLUDED A POSSIBILITY OF SPRINKLES. AFTER
THIS...GEOPOTENTIAL HEIGHTS RISE AND UPPER LEVEL RIDGING BUILDS
IN THROUGH THE MIDDLE OF THE WEEK. THIS SHOULD BRING MAINLY DRY
WEATHER AND GRADUALLY INCREASING TEMPERATURES. MODELS DO GENERATE
A BIT OF LIGHT PRECIP AT TIMES IN A DIURNAL PATTERN WITH DAYTIME
HEATING...ESPECIALLY THE GFS. SOUNDINGS DO NOT LOOK ALL THAT
FAVORABLE FOR PRECIP...AND HAVE OPTED TO KEEP POPS SUB-20 PERCENT
IN THE FORECAST AREA UNTIL THURSDAY. BY THEN...LOW LEVEL MOISTURE
COULD PERHAPS RECOVER ENOUGH FOR ISOLATED THUNDERSTORMS TO
DEVELOP.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 740 PM EDT THU APR 30 2015
MOST SITES ARE KEEPING IN THE VFR RANGE THIS AFTERNOON AND
EVENING...HOWEVER THOSE SITES THAT DO SEE SHOWERS AND ISOLATED
STORMS COULD SEE BRIEF DROPS TO MVFR/IFR. THESE SHOWERS AND
ISOLATED STORMS HAVE BEEN SLOWLY DIEING THIS EVENING AND BASED ON
THE HRRR THIS WOULD BE THE TREND THROUGH EVENING. THEN WE TURN TO
THE POSSIBILITY OF A STATUS DECK OVERNIGHT AND HAVE GIVEN MOST
SITES A BKN MVFR DECK OVERNIGHT GIVEN THE LOWER CONFIDENCE. WINDS
THROUGH THE PERIOD WILL GENERALLY BE LIGHT AND VRB...UNLESS YOU
GET CLOSER TO A STORM OR OUTFLOW IN THE EARLY EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM...HAL
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
739 PM EDT Thu Apr 30 2015
...Forecast Update...
Updated 740 PM EDT Thu Apr 30 2015
The forecast remains on track this evening, and have only updated to
reflect latest trends and remove thunder and evening wording. The
center of a closed upper low is now centered over eastern KY and
will continue to slide southeast this evening. Coverage/intensity of
showers and a few storms has diminished early this evening with the
loss of heating and as the feature moves SE. Will go with just
isolated to widely scattered mention of showers for another few
hours across our SE half of the CWA, then quiet after that.
A few clouds will hang around through the overnight mainly across
our east. Temperatures will get quite chilly, dropping into the
upper 30s and low 40s.
.SHORT TERM (Now through Friday Night)...
Issued at 305 PM EDT Thu Apr 30 2015
Unseasonably cold mid-level low continues to move southward and was
centered over west-central IN at mid-afternoon. The low will
propagate over central and eastern KY this evening. As expected,
cold mid-level temperatures combined with modest low-level heating
have steepened lapse rates and facilitated development of scattered
to numerous showers and a few thunderstorms. A few cells have
produced pea size hail, brief wind gusts up to 40 mph, and some
lightning strikes.
Currently, radar data shows better precipitation coverage over
east-central KY including the Lexington area, and approaching the
eastern half of south-central IN from the north. Latest HRRR model
reflectivity forecast captures these areas reasonably well. It
maintains the southern IN cells, moving them south-southeast into
north-central and east-central KY late this afternoon. Other pop up
cells could occur elsewhere as well. Thus, will maintain highest
coverage/percentage of precipitation east of Interstate 65,
especially over east-central KY.
Rainfall intensity and coverage will slowly diminish this evening
with loss of daytime heating and as the upper low moves eastward.
Overnight, dry weather is expected with some clouds remaining over
the east, with fewer clouds over western parts of our forecast area.
There could be patchy fog near daybreak over parts of east-central
KY. It will be chilly, with lows Friday morning in the upper 30s and
lower 40s in many areas.
On Friday, the mid-level low will continue pulling eastward away
from our area. There could be some residual clouds over the east
half of our forecast area, but dry weather is expected. Temperatures
will begin a warming trend that will last through the weekend and
into next week. Expect highs Friday afternoon in the mid 60s to
lower 70s.
.LONG TERM (Saturday through Thursday)...
Issued at 315 PM EDT Thu Apr 30 2015
Saturday - Saturday Night...
NW flow aloft will dominate the pattern, meanwhile surface high
pressure will be in place. Models have been consistent now for the
past several runs in depicting a shortwave embedded in the flow
traversing the area on Saturday. Will continue to keep the forecast
dry as this feature looks starved of moisture. Instead, will depict
an increase in cloud cover through the afternoon, although still
expect partly sunny skies. With plenty of peaks at the sun, will
call for temps mostly in the mid 70s. A few spots that see more
clouds may stay in the low 70s.
Dry conditions will continue into Saturday night where weak and
progressive upper ridging slides over the Ohio River Valley.
Meanwhile, surface high pressure remains at the surface. Given good
radiational cooling conditions, lows will still slide into the upper
40s and low 50s.
Sunday - Thursday...
Low amplitude NW flow aloft will transition to upper ridging over
the CWA to end the weekend and start the new work week. This ridge
is then expected to hold over the area through the end of the week.
A frontal boundary that looks to stall nearly parallel to the upper
flow should stay well to the north across the southern Great Lakes.
This pattern will result in continued dry conditions and
temperatures rising above normal for this time of year. Can`t rule
out an extremely isolated shower or t-storm at some point through
the week, however lack of a trigger and mid level subsidence
inversion is enough to keep a dry forecast going.
Have nudged temperatures up around MEX guidance given the warmer
pattern, and wouldn`t be surprised if they end up a couple of
degrees warmer. This will result in forecast temperatures more
solidly in the low and mid 80s Tue-Thur. Will go with upper 70s to
around 80 for Sunday, and around 80 for Monday. Lows each night
should mostly be in the 50s, with the usual warm spots likely around
60.
&&
.AVIATION (00Z TAF Update)...
Updated at 709 PM EDT Thu Apr 30 2015
The center of the upper low will slide southeast of the TAF sites
later this evening. Showers and a few t-storms are quickly
diminishing across the area as the features begins to move overhead.
Will go dry at the terminals to start the new cycle with steady N
winds and a few-sct mid level clouds. Will continue VFR conditions
through tomorrow with a continued NNW surface wind between 5 and 10
mph. There is some data that would support some lower clouds at
SDF/LEX in the morning hours, however not confident to include more
than few-sct mention at this time.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....TWF
Long Term......BJS
Aviation.......BJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
708 PM EDT Thu Apr 30 2015
...Updated Aviation Discussion...
.SHORT TERM (Now through Friday Night)...
Issued at 305 PM EDT Thu Apr 30 2015
Unseasonably cold mid-level low continues to move southward and was
centered over west-central IN at mid-afternoon. The low will
propagate over central and eastern KY this evening. As expected,
cold mid-level temperatures combined with modest low-level heating
have steepened lapse rates and facilitated development of scattered
to numerous showers and a few thunderstorms. A few cells have
produced pea size hail, brief wind gusts up to 40 mph, and some
lightning strikes.
Currently, radar data shows better precipitation coverage over
east-central KY including the Lexington area, and approaching the
eastern half of south-central IN from the north. Latest HRRR model
reflectivity forecast captures these areas reasonably well. It
maintains the southern IN cells, moving them south-southeast into
north-central and east-central KY late this afternoon. Other pop up
cells could occur elsewhere as well. Thus, will maintain highest
coverage/percentage of precipitation east of Interstate 65,
especially over east-central KY.
Rainfall intensity and coverage will slowly diminish this evening
with loss of daytime heating and as the upper low moves eastward.
Overnight, dry weather is expected with some clouds remaining over
the east, with fewer clouds over western parts of our forecast area.
There could be patchy fog near daybreak over parts of east-central
KY. It will be chilly, with lows Friday morning in the upper 30s and
lower 40s in many areas.
On Friday, the mid-level low will continue pulling eastward away
from our area. There could be some residual clouds over the east
half of our forecast area, but dry weather is expected. Temperatures
will begin a warming trend that will last through the weekend and
into next week. Expect highs Friday afternoon in the mid 60s to
lower 70s.
.LONG TERM (Saturday through Thursday)...
Issued at 315 PM EDT Thu Apr 30 2015
Saturday - Saturday Night...
NW flow aloft will dominate the pattern, meanwhile surface high
pressure will be in place. Models have been consistent now for the
past several runs in depicting a shortwave embedded in the flow
traversing the area on Saturday. Will continue to keep the forecast
dry as this feature looks starved of moisture. Instead, will depict
an increase in cloud cover through the afternoon, although still
expect partly sunny skies. With plenty of peaks at the sun, will
call for temps mostly in the mid 70s. A few spots that see more
clouds may stay in the low 70s.
Dry conditions will continue into Saturday night where weak and
progressive upper ridging slides over the Ohio River Valley.
Meanwhile, surface high pressure remains at the surface. Given good
radiational cooling conditions, lows will still slide into the upper
40s and low 50s.
Sunday - Thursday...
Low amplitude NW flow aloft will transition to upper ridging over
the CWA to end the weekend and start the new work week. This ridge
is then expected to hold over the area through the end of the week.
A frontal boundary that looks to stall nearly parallel to the upper
flow should stay well to the north across the southern Great Lakes.
This pattern will result in continued dry conditions and
temperatures rising above normal for this time of year. Can`t rule
out an extremely isolated shower or t-storm at some point through
the week, however lack of a trigger and mid level subsidence
inversion is enough to keep a dry forecast going.
Have nudged temperatures up around MEX guidance given the warmer
pattern, and wouldn`t be surprised if they end up a couple of
degrees warmer. This will result in forecast temperatures more
solidly in the low and mid 80s Tue-Thur. Will go with upper 70s to
around 80 for Sunday, and around 80 for Monday. Lows each night
should mostly be in the 50s, with the usual warm spots likely around
60.
&&
.AVIATION (00Z TAF Update)...
Updated at 709 PM EDT Thu Apr 30 2015
The center of the upper low will slide southeast of the TAF sites
later this evening. Showers and a few t-storms are quickly
diminishing across the area as the features begins to move overhead.
Will go dry at the terminals to start the new cycle with steady N
winds and a few-sct mid level clouds. Will continue VFR conditions
through tomorrow with a continued NNW surface wind between 5 and 10
mph. There is some data that would support some lower clouds at
SDF/LEX in the morning hours, however not confident to include more
than few-sct mention at this time.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........TWF
Long Term.........BJS
Aviation..........BJS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
154 PM EDT WED APR 29 2015
.UPDATE...
ISSUED AT 200 PM EDT WED APR 29 2015
TEMPERATURES HAVE RECOVERED WELL THIS AFTERNOON AS THE CLOUDS
OVER SOUTHEASTERN KENTUCKY DISSIPATED. ADDITIONAL CU IS DEVELOPING
OVER THE CWA SO HAVE KEPT THE INCREASING SKY COVER TREND IN THE
FORECAST. ALIGNED T AND TD GRIDS TO REFLECT CURRENT OBS. SENT
UPDATED GRIDS TO NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1055 AM EDT WED APR 29 2015
CLOUD COVER SEEMS TO BE CONSTRAINED TO THE SOUTHERN AND FAR
EASTERN COUNTIES AS THE SFC LOW PASSES TO OUR SOUTH...SO HAVE
BUMPED TEMPS DOWN IN THOSE AREAS. ALSO ADJUSTED SKY GRIDS TO
BETTER REFLECT CURRENT CLOUD COVER. SUSPECT MOSTLY CLEAR SKIES
WILL BE MAINTAINED IN THE NORTHERN AND WESTERN COUNTIES THROUGH
THIS AFTERNOON. NO OTHER CHANGES WERE MADE TO TODAYS FORECAST
PERIOD. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS.
UPDATE ISSUED AT 735 AM EDT WED APR 29 2015
TOUCHED UP THE GRIDS A BIT FOR THE NEXT SEVERAL HOURS PER THE
LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED APR 29 2015
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE MOVING THROUGH
THE SOUTHEAST QUARTER OF THE NATION. THE SHOWERS ASSOCIATED WITH
THIS ARE MAKING ONLY SLOW PROGRESS NORTH AND INTO TENNESSEE WHILE
THE LATEST HRRR AND NAM12 KEEP IT OUT OF KENTUCKY ENTIRELY.
HOWEVER...SOME HIGH AND MID LEVEL CLOUDS HAVE MANAGED TO PUSH INTO
SOUTHERN PARTS OF THE STATE. THESE CLOUDS...AND A SLIGHT INCREASE
IN MOISTURE...ARE HELPING TO KEEP THE TEMPERATURES THERE...EVEN IN
MOST OF THE VALLEYS...MORE UNIFORM FROM 45 TO 50 DEGREES.
MEANWHILE...TO THE NORTH...CLEAR SKIES AND LIGHT WINDS HAVE
ALLOWED A DECENT RIDGE TO VALLEY SPLIT TO DEVELOP WITH READINGS
VARYING FROM THE LOWER 50S ABOVE THE INVERSION TO THE LOWER 40S IN
THE SHELTERED SPOTS BELOW IT. DEWPOINTS...IN GENERAL...VARY ACROSS
THE AREA FROM THE LOWER 40S IN THE FAR SOUTH TO THE MID 30S IN THE
NORTH. WINDS THROUGHOUT EAST KENTUCKY ARE LIGHT AND VARIABLE IF
NOT OUTRIGHT CALM.
THE MODELS APPEAR TO BE SETTLING ON A SOLUTION AT MID LEVELS FOR
THE SHORT TERM PORTION OF THE FORECAST. THEY ALL AGREE WITH A
SOUTHERN STREAM WAVE OPENING UP AS IT MOVES INTO THE DEEP SOUTH
TODAY. IT IS THEN JOINED BY A TRAILING NORTHERN STREAM WAVE
DROPPING MAINLY SOUTH THROUGH THE MISSISSIPPI VALLEY. THESE WAVES
WILL MAINTAIN A TROUGH OVER THE NORTHEAST THIRD OF THE NATION
THROUGH THE DAY TODAY. A MORE SUBSTANTIAL WAVE WILL THEN DESCEND
THE WESTERN FLANK OF THE OHIO VALLEY TONIGHT...SHARPENING UP AS IT
MOVES INTO KENTUCKY BY MIDDAY THURSDAY. THIS CLOSED...BUT FAIRLY
QUICK MOVING...LOW WILL PUNCH THROUGH EAST KENTUCKY THURSDAY
AFTERNOON AND EVENING WITH PLENTY OF MID LEVEL ENERGY AND A CORE
OF COLDER 500 MB TEMPS. THE GFS STILL REMAINS THE STRONGEST MODEL
WITH THIS AND ALSO A BIT SLOWER. IT DOES APPEAR THAT THE OTHERS
ARE COMING AROUND TO THIS IDEA...THOUGH...WITH THE NAM
REPRESENTING A GOOD COMPROMISE. ACCORDINGLY...HAVE GONE WITH A
MAINLY NAM12 SOLUTION THROUGH THE SHORT TERM...ALONG WITH THE
WELL ALIGNED HRRR FOR TODAY/S PORTION.
SENSIBLE WEATHER WILL FEATURE A PARTLY TO MOSTLY CLOUDY DAY AS THE
SYSTEM PASSES HARMLESSLY TO THE SOUTH...ROBBING US OF ANOTHER
CHANCE TO GET SOME RAINFALL THAT WOULD GO TOWARD BREAKING THE
RECORD FOR THE MONTH HERE AT JKL. WITH LESS PCPN AND CLOUDS
ANTICIPATED TODAY...TEMPERATURES WILL BE A BIT WARMER THAN
EXPECTED 24 HOURS AGO. ACCORDINGLY...HAVE BUMPED THEM UP INTO THE
MID AND UPPER 60S MOST PLACES. AN APPROACHING SHORTWAVE AT MID
LEVELS TONIGHT WILL BRING IN A DECK OF MID LEVEL CLOUDS THAT WILL
LOWER THROUGH THE NIGHT...BUT SERVE TO KEEP TEMPERATURES RATHER
UNIFORM. SHOWERS WILL BE POSSIBLE BY DAWN IN THE NORTHWEST PARTS
OF THE AREA AS THE SFC REFLECTION OF THAT MID LEVEL WAVE MOVES
INTO KENTUCKY. LAPSE RATES WILL INCREASE THROUGH THE AFTERNOON ON
THURSDAY WITH CLIMBING CAPE AND FALLING LIS AS THE UPPER LOW MOVES
OVERHEAD. AS A RESULT...THUNDERSTORMS WILL BE POSSIBLE THAT
MORNING AND A BETTER BET BY AFTERNOON DUE TO BETTER INSULATION AND
COLD MID LEVELS. HAVE UPGRADED THE THUNDER CHANCES TO SCATTERED
FROM SLIGHT FOR THURSDAY AFTERNOON AND AM ALSO CONCERNED ABOUT
GRAUPEL FROM ANY STRONGER SHOWER OF STORM SO WILL ADD A MENTION TO
THE FORTHCOMING HWO. THE CLOUDS AND CONVECTION WILL LIKELY KEEP
TEMPS ON THE COOL SIDE THURSDAY DESPITE THE THUNDER CHANCES.
FOR TEMPERATURES/DEWPOINTS/WINDS HAVE STARTED WITH THE SHORTBLEND
GUIDANCE THROUGH THE FIRST PART OF THE FORECAST AND THE SUPERBLEND
AFTER THAT. DID MAKE SOME MINOR ADJUSTMENTS TO THE TEMPERATURES
BASED ON TERRAIN THIS MORNING AND TONIGHT. AS FOR POPS...ENDED UP
SIMILAR TO LOWER GUIDANCE TODAY/TONIGHT AND A BIT HIGHER ON
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 AM EDT WED APR 29 2015
THE EXTENDED PERIOD WILL START OUT WET AND RAINY AS A WEATHER SYSTEM
PUSHES OFF TO OUR EAST THURSDAY NIGHT AND FRIDAY. RUN OF THE MILL
RAIN SHOWERS WILL AFFECT THE AREA AS AN AREA OF LOW PRESSURE ALOFT
MOVES OUT OF THE GREAT LAKES REGION AND ACROSS THE CENTRAL AND
EASTERN OHIO VALLEY. COOLER AIR AND LACK OF INSTABILITY WILL
EFFECTIVELY KILL ANY CHANCES FOR THUNDER. THE RAIN SHOULD BE LIGHT
IN NATURE AND WILL NOT CAUSE ANY HYDRO ISSUES. AFTER LATE FRIDAY
AFTERNOON...THE FORECAST LOOKS DRY AND WARM AS A LARGE AND RATHER
STRONG RIDGE OF HIGH PRESSURE SETTLES OVER THE SOUTHEASTERN CONUS.
THE LONG TERM MODELS DO TRY TO PRODUCE A BIT OF SPOTTY PRECIPITATION
FROM TIME TO TIME DURING THE EXTENDED PERIOD FROM SATURDAY
ONWARD...BUT CONSIDERING THE STRENGTH OF THE RIDGE IN THE
MODELS...AND NO APPRECIABLE SIGNAL FOR PRECIP IN THE MODEL SOUNDINGS
AND TIME HEIGHTS...DECIDED TO KEEP PRECIPITATION OUT OF THE PICTURE
UNTIL THE VERY END OF THE PERIOD...WHEN THE GFS MODEL ATTEMPTS TO
SAG A FRONTAL BOUNDARY SOUTHWARD OUT OF INDIANA...OHIO...AND
ILLINOIS.
TEMPERATURES THE FIRST COUPLE OF DAYS OF THE PERIOD WILL LIKELY BE
SLIGHTLY BELOW NORMAL DUE TO THE INFLUENCE OF CLOUDS AND
PRECIPITATION AND WESTERLY FLOW BEHIND THE DEPARTED WEATHER SYSTEM.
FROM SUNDAY ONWARD...THE WEATHER SHOULD BE MARKEDLY WARMER AS THE
RIDGE OF HIGH PRESSURE SETTLES OVER THE REGION...BRINGING LIGHT
WINDS AND AMPLE SUNSHINE TO THE OHIO AND TENNESSEE VALLEYS. HIGHS ON
EACH OF THESE DAYS WILL LIKELY BE ABOVE NORMAL...WITH MAX READINGS
ON MONDAY TUESDAY POSSIBLE TOPPING OUT IN THE UPPER 70S AROUND THE
AREA. A FEW LOCATIONS ON TUESDAY MAY EVEN TOP 80 DEGREES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 145 PM EDT WED APR 29 2015
MAINLY VFR CONDITIONS SHOULD PREVAIL THROUGH THE FIRST 12 TO 18
HOURS OF THE PERIOD. DIURNALLY DRIVEN SCT TO BKN CU NEAR 5 TO 6KFT
ARE EXPECTED TO CONTINUE TO DEVELOP AND WITH MOISTURE EXPECTED TO
CONTINUE TO INCREASE AROUND THAT LEVEL...A VFR CIG NEAR 5 TO 6KFT
SHOULD DEVELOP BY 0Z TO 6Z PERIOD. AS AN UPPER LEVEL LOW PRESSURE
SYSTEM APPROACHES...SOME SHRA WILL BE POSSIBLE FROM 9Z ON...STARTING
IN THE NORTH. ENOUGH INSTABILITY FROM COOLING ALOFT AND SOME
SURFACE HEATING MAY BE IN PLACE PRIOR TO THE END OF THE PERIOD FOR
ISOLATED TO POSSIBLY SCATTERED TSRA. WINDS WILL AVERAGE 10 KT OR
LESS THROUGH THE PERIOD...GENERALLY OF VARIABLE DIRECTION WHEN NOT
OUT OF THE NORTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
1055 AM EDT WED APR 29 2015
.UPDATE...
ISSUED AT 1055 AM EDT WED APR 29 2015
CLOUD COVER SEEMS TO BE CONSTRAINED TO THE SOUTHERN AND FAR
EASTERN COUNTIES AS THE SFC LOW PASSES TO OUR SOUTH...SO HAVE
BUMPED TEMPS DOWN IN THOSE AREAS. ALSO ADJUSTED SKY GRIDS TO
BETTER REFLECT CURRENT CLOUD COVER. SUSPECT MOSTLY CLEAR SKIES
WILL BE MAINTAINED IN THE NORTHERN AND WESTERN COUNTIES THROUGH
THIS AFTERNOON. NO OTHER CHANGES WERE MADE TO TODAYS FORECAST
PERIOD. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS.
UPDATE ISSUED AT 735 AM EDT WED APR 29 2015
TOUCHED UP THE GRIDS A BIT FOR THE NEXT SEVERAL HOURS PER THE
LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED APR 29 2015
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE MOVING THROUGH
THE SOUTHEAST QUARTER OF THE NATION. THE SHOWERS ASSOCIATED WITH
THIS ARE MAKING ONLY SLOW PROGRESS NORTH AND INTO TENNESSEE WHILE
THE LATEST HRRR AND NAM12 KEEP IT OUT OF KENTUCKY ENTIRELY.
HOWEVER...SOME HIGH AND MID LEVEL CLOUDS HAVE MANAGED TO PUSH INTO
SOUTHERN PARTS OF THE STATE. THESE CLOUDS...AND A SLIGHT INCREASE
IN MOISTURE...ARE HELPING TO KEEP THE TEMPERATURES THERE...EVEN IN
MOST OF THE VALLEYS...MORE UNIFORM FROM 45 TO 50 DEGREES.
MEANWHILE...TO THE NORTH...CLEAR SKIES AND LIGHT WINDS HAVE
ALLOWED A DECENT RIDGE TO VALLEY SPLIT TO DEVELOP WITH READINGS
VARYING FROM THE LOWER 50S ABOVE THE INVERSION TO THE LOWER 40S IN
THE SHELTERED SPOTS BELOW IT. DEWPOINTS...IN GENERAL...VARY ACROSS
THE AREA FROM THE LOWER 40S IN THE FAR SOUTH TO THE MID 30S IN THE
NORTH. WINDS THROUGHOUT EAST KENTUCKY ARE LIGHT AND VARIABLE IF
NOT OUTRIGHT CALM.
THE MODELS APPEAR TO BE SETTLING ON A SOLUTION AT MID LEVELS FOR
THE SHORT TERM PORTION OF THE FORECAST. THEY ALL AGREE WITH A
SOUTHERN STREAM WAVE OPENING UP AS IT MOVES INTO THE DEEP SOUTH
TODAY. IT IS THEN JOINED BY A TRAILING NORTHERN STREAM WAVE
DROPPING MAINLY SOUTH THROUGH THE MISSISSIPPI VALLEY. THESE WAVES
WILL MAINTAIN A TROUGH OVER THE NORTHEAST THIRD OF THE NATION
THROUGH THE DAY TODAY. A MORE SUBSTANTIAL WAVE WILL THEN DESCEND
THE WESTERN FLANK OF THE OHIO VALLEY TONIGHT...SHARPENING UP AS IT
MOVES INTO KENTUCKY BY MIDDAY THURSDAY. THIS CLOSED...BUT FAIRLY
QUICK MOVING...LOW WILL PUNCH THROUGH EAST KENTUCKY THURSDAY
AFTERNOON AND EVENING WITH PLENTY OF MID LEVEL ENERGY AND A CORE
OF COLDER 500 MB TEMPS. THE GFS STILL REMAINS THE STRONGEST MODEL
WITH THIS AND ALSO A BIT SLOWER. IT DOES APPEAR THAT THE OTHERS
ARE COMING AROUND TO THIS IDEA...THOUGH...WITH THE NAM
REPRESENTING A GOOD COMPROMISE. ACCORDINGLY...HAVE GONE WITH A
MAINLY NAM12 SOLUTION THROUGH THE SHORT TERM...ALONG WITH THE
WELL ALIGNED HRRR FOR TODAY/S PORTION.
SENSIBLE WEATHER WILL FEATURE A PARTLY TO MOSTLY CLOUDY DAY AS THE
SYSTEM PASSES HARMLESSLY TO THE SOUTH...ROBBING US OF ANOTHER
CHANCE TO GET SOME RAINFALL THAT WOULD GO TOWARD BREAKING THE
RECORD FOR THE MONTH HERE AT JKL. WITH LESS PCPN AND CLOUDS
ANTICIPATED TODAY...TEMPERATURES WILL BE A BIT WARMER THAN
EXPECTED 24 HOURS AGO. ACCORDINGLY...HAVE BUMPED THEM UP INTO THE
MID AND UPPER 60S MOST PLACES. AN APPROACHING SHORTWAVE AT MID
LEVELS TONIGHT WILL BRING IN A DECK OF MID LEVEL CLOUDS THAT WILL
LOWER THROUGH THE NIGHT...BUT SERVE TO KEEP TEMPERATURES RATHER
UNIFORM. SHOWERS WILL BE POSSIBLE BY DAWN IN THE NORTHWEST PARTS
OF THE AREA AS THE SFC REFLECTION OF THAT MID LEVEL WAVE MOVES
INTO KENTUCKY. LAPSE RATES WILL INCREASE THROUGH THE AFTERNOON ON
THURSDAY WITH CLIMBING CAPE AND FALLING LIS AS THE UPPER LOW MOVES
OVERHEAD. AS A RESULT...THUNDERSTORMS WILL BE POSSIBLE THAT
MORNING AND A BETTER BET BY AFTERNOON DUE TO BETTER INSULATION AND
COLD MID LEVELS. HAVE UPGRADED THE THUNDER CHANCES TO SCATTERED
FROM SLIGHT FOR THURSDAY AFTERNOON AND AM ALSO CONCERNED ABOUT
GRAUPEL FROM ANY STRONGER SHOWER OF STORM SO WILL ADD A MENTION TO
THE FORTHCOMING HWO. THE CLOUDS AND CONVECTION WILL LIKELY KEEP
TEMPS ON THE COOL SIDE THURSDAY DESPITE THE THUNDER CHANCES.
FOR TEMPERATURES/DEWPOINTS/WINDS HAVE STARTED WITH THE SHORTBLEND
GUIDANCE THROUGH THE FIRST PART OF THE FORECAST AND THE SUPERBLEND
AFTER THAT. DID MAKE SOME MINOR ADJUSTMENTS TO THE TEMPERATURES
BASED ON TERRAIN THIS MORNING AND TONIGHT. AS FOR POPS...ENDED UP
SIMILAR TO LOWER GUIDANCE TODAY/TONIGHT AND A BIT HIGHER ON
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 AM EDT WED APR 29 2015
THE EXTENDED PERIOD WILL START OUT WET AND RAINY AS A WEATHER SYSTEM
PUSHES OFF TO OUR EAST THURSDAY NIGHT AND FRIDAY. RUN OF THE MILL
RAIN SHOWERS WILL AFFECT THE AREA AS AN AREA OF LOW PRESSURE ALOFT
MOVES OUT OF THE GREAT LAKES REGION AND ACROSS THE CENTRAL AND
EASTERN OHIO VALLEY. COOLER AIR AND LACK OF INSTABILITY WILL
EFFECTIVELY KILL ANY CHANCES FOR THUNDER. THE RAIN SHOULD BE LIGHT
IN NATURE AND WILL NOT CAUSE ANY HYDRO ISSUES. AFTER LATE FRIDAY
AFTERNOON...THE FORECAST LOOKS DRY AND WARM AS A LARGE AND RATHER
STRONG RIDGE OF HIGH PRESSURE SETTLES OVER THE SOUTHEASTERN CONUS.
THE LONG TERM MODELS DO TRY TO PRODUCE A BIT OF SPOTTY PRECIPITATION
FROM TIME TO TIME DURING THE EXTENDED PERIOD FROM SATURDAY
ONWARD...BUT CONSIDERING THE STRENGTH OF THE RIDGE IN THE
MODELS...AND NO APPRECIABLE SIGNAL FOR PRECIP IN THE MODEL SOUNDINGS
AND TIME HEIGHTS...DECIDED TO KEEP PRECIPITATION OUT OF THE PICTURE
UNTIL THE VERY END OF THE PERIOD...WHEN THE GFS MODEL ATTEMPTS TO
SAG A FRONTAL BOUNDARY SOUTHWARD OUT OF INDIANA...OHIO...AND
ILLINOIS.
TEMPERATURES THE FIRST COUPLE OF DAYS OF THE PERIOD WILL LIKELY BE
SLIGHTLY BELOW NORMAL DUE TO THE INFLUENCE OF CLOUDS AND
PRECIPITATION AND WESTERLY FLOW BEHIND THE DEPARTED WEATHER SYSTEM.
FROM SUNDAY ONWARD...THE WEATHER SHOULD BE MARKEDLY WARMER AS THE
RIDGE OF HIGH PRESSURE SETTLES OVER THE REGION...BRINGING LIGHT
WINDS AND AMPLE SUNSHINE TO THE OHIO AND TENNESSEE VALLEYS. HIGHS ON
EACH OF THESE DAYS WILL LIKELY BE ABOVE NORMAL...WITH MAX READINGS
ON MONDAY TUESDAY POSSIBLE TOPPING OUT IN THE UPPER 70S AROUND THE
AREA. A FEW LOCATIONS ON TUESDAY MAY EVEN TOP 80 DEGREES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 755 AM EDT WED APR 29 2015
STILL EXPECT VFR CONDITIONS THROUGH THE PERIOD. MAINLY HIGH
CLOUDS WILL BE SEEN THROUGH THE MORNING AND AND INTO THE START OF
THE AFTERNOON WITH A LOWER DECK OF CLOUDS LIKELY FORMING FROM
SOUTH TO NORTH FROM MIDDAY ON...HOWEVER THESE WILL PROBABLY HOLD
AROUND 5K FEET AGL. SOME SHOWERS MAY THREATEN IN THE FAR SOUTH...
THOUGH THEY WILL MOST LIKELY OCCUR SOUTH OF THE KENTUCKY BORDER
AND FAR FROM ANY TAF SITE. WINDS WILL AVERAGE AROUND 5 KTS OR LESS
THROUGH THE PERIOD...GENERALLY OF VARIABLE DIRECTION WHEN NOT OUT
OF THE NORTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
755 AM EDT WED APR 29 2015
.UPDATE...
ISSUED AT 735 AM EDT WED APR 29 2015
TOUCHED UP THE GRIDS A BIT FOR THE NEXT SEVERAL HOURS PER THE
LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED APR 29 2015
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE MOVING THROUGH
THE SOUTHEAST QUARTER OF THE NATION. THE SHOWERS ASSOCIATED WITH
THIS ARE MAKING ONLY SLOW PROGRESS NORTH AND INTO TENNESSEE WHILE
THE LATEST HRRR AND NAM12 KEEP IT OUT OF KENTUCKY ENTIRELY.
HOWEVER...SOME HIGH AND MID LEVEL CLOUDS HAVE MANAGED TO PUSH INTO
SOUTHERN PARTS OF THE STATE. THESE CLOUDS...AND A SLIGHT INCREASE
IN MOISTURE...ARE HELPING TO KEEP THE TEMPERATURES THERE...EVEN IN
MOST OF THE VALLEYS...MORE UNIFORM FROM 45 TO 50 DEGREES.
MEANWHILE...TO THE NORTH...CLEAR SKIES AND LIGHT WINDS HAVE
ALLOWED A DECENT RIDGE TO VALLEY SPLIT TO DEVELOP WITH READINGS
VARYING FROM THE LOWER 50S ABOVE THE INVERSION TO THE LOWER 40S IN
THE SHELTERED SPOTS BELOW IT. DEWPOINTS...IN GENERAL...VARY ACROSS
THE AREA FROM THE LOWER 40S IN THE FAR SOUTH TO THE MID 30S IN THE
NORTH. WINDS THROUGHOUT EAST KENTUCKY ARE LIGHT AND VARIABLE IF
NOT OUTRIGHT CALM.
THE MODELS APPEAR TO BE SETTLING ON A SOLUTION AT MID LEVELS FOR
THE SHORT TERM PORTION OF THE FORECAST. THEY ALL AGREE WITH A
SOUTHERN STREAM WAVE OPENING UP AS IT MOVES INTO THE DEEP SOUTH
TODAY. IT IS THEN JOINED BY A TRAILING NORTHERN STREAM WAVE
DROPPING MAINLY SOUTH THROUGH THE MISSISSIPPI VALLEY. THESE WAVES
WILL MAINTAIN A TROUGH OVER THE NORTHEAST THIRD OF THE NATION
THROUGH THE DAY TODAY. A MORE SUBSTANTIAL WAVE WILL THEN DESCEND
THE WESTERN FLANK OF THE OHIO VALLEY TONIGHT...SHARPENING UP AS IT
MOVES INTO KENTUCKY BY MIDDAY THURSDAY. THIS CLOSED...BUT FAIRLY
QUICK MOVING...LOW WILL PUNCH THROUGH EAST KENTUCKY THURSDAY
AFTERNOON AND EVENING WITH PLENTY OF MID LEVEL ENERGY AND A CORE
OF COLDER 500 MB TEMPS. THE GFS STILL REMAINS THE STRONGEST MODEL
WITH THIS AND ALSO A BIT SLOWER. IT DOES APPEAR THAT THE OTHERS
ARE COMING AROUND TO THIS IDEA...THOUGH...WITH THE NAM
REPRESENTING A GOOD COMPROMISE. ACCORDINGLY...HAVE GONE WITH A
MAINLY NAM12 SOLUTION THROUGH THE SHORT TERM...ALONG WITH THE
WELL ALIGNED HRRR FOR TODAY/S PORTION.
SENSIBLE WEATHER WILL FEATURE A PARTLY TO MOSTLY CLOUDY DAY AS THE
SYSTEM PASSES HARMLESSLY TO THE SOUTH...ROBBING US OF ANOTHER
CHANCE TO GET SOME RAINFALL THAT WOULD GO TOWARD BREAKING THE
RECORD FOR THE MONTH HERE AT JKL. WITH LESS PCPN AND CLOUDS
ANTICIPATED TODAY...TEMPERATURES WILL BE A BIT WARMER THAN
EXPECTED 24 HOURS AGO. ACCORDINGLY...HAVE BUMPED THEM UP INTO THE
MID AND UPPER 60S MOST PLACES. AN APPROACHING SHORTWAVE AT MID
LEVELS TONIGHT WILL BRING IN A DECK OF MID LEVEL CLOUDS THAT WILL
LOWER THROUGH THE NIGHT...BUT SERVE TO KEEP TEMPERATURES RATHER
UNIFORM. SHOWERS WILL BE POSSIBLE BY DAWN IN THE NORTHWEST PARTS
OF THE AREA AS THE SFC REFLECTION OF THAT MID LEVEL WAVE MOVES
INTO KENTUCKY. LAPSE RATES WILL INCREASE THROUGH THE AFTERNOON ON
THURSDAY WITH CLIMBING CAPE AND FALLING LIS AS THE UPPER LOW MOVES
OVERHEAD. AS A RESULT...THUNDERSTORMS WILL BE POSSIBLE THAT
MORNING AND A BETTER BET BY AFTERNOON DUE TO BETTER INSOLATION AND
COLD MID LEVELS. HAVE UPGRADED THE THUNDER CHANCES TO SCATTERED
FROM SLIGHT FOR THURSDAY AFTERNOON AND AM ALSO CONCERNED ABOUT
GRAUPEL FROM ANY STRONGER SHOWER OF STORM SO WILL ADD A MENTION TO
THE FORTHCOMING HWO. THE CLOUDS AND CONVECTION WILL LIKELY KEEP
TEMPS ON THE COOL SIDE THURSDAY DESPITE THE THUNDER CHANCES.
FOR TEMPERATURES/DEWPOINTS/WINDS HAVE STARTED WITH THE SHORTBLEND
GUIDANCE THROUGH THE FIRST PART OF THE FORECAST AND THE SUPERBLEND
AFTER THAT. DID MAKE SOME MINOR ADJUSTMENTS TO THE TEMPERATURES
BASED ON TERRAIN THIS MORNING AND TONIGHT. AS FOR POPS...ENDED UP
SIMILAR TO LOWER GUIDANCE TODAY/TONIGHT AND A BIT HIGHER ON
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 AM EDT WED APR 29 2015
THE EXTENDED PERIOD WILL START OUT WET AND RAINY AS A WEATHER SYSTEM
PUSHES OFF TO OUR EAST THURSDAY NIGHT AND FRIDAY. RUN OF THE MILL
RAIN SHOWERS WILL AFFECT THE AREA AS AN AREA OF LOW PRESSURE ALOFT
MOVES OUT OF THE GREAT LAKES REGION AND ACROSS THE CENTRAL AND
EASTERN OHIO VALLEY. COOLER AIR AND LACK OF INSTABILITY WILL
EFFECTIVELY KILL ANY CHANCES FOR THUNDER. THE RAIN SHOULD BE LIGHT
IN NATURE AND WILL NOT CAUSE ANY HYDRO ISSUES. AFTER LATE FRIDAY
AFTERNOON...THE FORECAST LOOKS DRY AND WARM AS A LARGE AND RATHER
STRONG RIDGE OF HIGH PRESSURE SETTLES OVER THE SOUTHEASTERN CONUS.
THE LONG TERM MODELS DO TRY TO PRODUCE A BIT OF SPOTTY PRECIPITATION
FROM TIME TO TIME DURING THE EXTENDED PERIOD FROM SATURDAY
ONWARD...BUT CONSIDERING THE STRENGTH OF THE RIDGE IN THE
MODELS...AND NO APPRECIABLE SIGNAL FOR PRECIP IN THE MODEL SOUNDINGS
AND TIME HEIGHTS...DECIDED TO KEEP PRECIPITATION OUT OF THE PICTURE
UNTIL THE VERY END OF THE PERIOD...WHEN THE GFS MODEL ATTEMPTS TO
SAG A FRONTAL BOUNDARY SOUTHWARD OUT OF INDIANA...OHIO...AND
ILLINOIS.
TEMPERATURES THE FIRST COUPLE OF DAYS OF THE PERIOD WILL LIKELY BE
SLIGHTLY BELOW NORMAL DUE TO THE INFLUENCE OF CLOUDS AND
PRECIPITATION AND WESTERLY FLOW BEHIND THE DEPARTED WEATHER SYSTEM.
FROM SUNDAY ONWARD...THE WEATHER SHOULD BE MARKEDLY WARMER AS THE
RIDGE OF HIGH PRESSURE SETTLES OVER THE REGION...BRINGING LIGHT
WINDS AND AMPLE SUNSHINE TO THE OHIO AND TENNESSEE VALLEYS. HIGHS ON
EACH OF THESE DAYS WILL LIKELY BE ABOVE NORMAL...WITH MAX READINGS
ON MONDAY TUESDAY POSSIBLE TOPPING OUT IN THE UPPER 70S AROUND THE
AREA. A FEW LOCATIONS ON TUESDAY MAY EVEN TOP 80 DEGREES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 755 AM EDT WED APR 29 2015
STILL EXPECT VFR CONDITIONS THROUGH THE PERIOD. MAINLY HIGH
CLOUDS WILL BE SEEN THROUGH THE MORNING AND AND INTO THE START OF
THE AFTERNOON WITH A LOWER DECK OF CLOUDS LIKELY FORMING FROM
SOUTH TO NORTH FROM MIDDAY ON...HOWEVER THESE WILL PROBABLY HOLD
AROUND 5K FEET AGL. SOME SHOWERS MAY THREATEN IN THE FAR SOUTH...
THOUGH THEY WILL MOST LIKELY OCCUR SOUTH OF THE KENTUCKY BORDER
AND FAR FROM ANY TAF SITE. WINDS WILL AVERAGE AROUND 5 KTS OR LESS
THROUGH THE PERIOD...GENERALLY OF VARIABLE DIRECTION WHEN NOT OUT
OF THE NORTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
340 AM EDT WED APR 29 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED APR 29 2015
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE MOVING THROUGH
THE SOUTHEAST QUARTER OF THE NATION. THE SHOWERS ASSOCIATED WITH
THIS ARE MAKING ONLY SLOW PROGRESS NORTH AND INTO TENNESSEE WHILE
THE LATEST HRRR AND NAM12 KEEP IT OUT OF KENTUCKY ENTIRELY.
HOWEVER...SOME HIGH AND MID LEVEL CLOUDS HAVE MANAGED TO PUSH INTO
SOUTHERN PARTS OF THE STATE. THESE CLOUDS...AND A SLIGHT INCREASE
IN MOISTURE...ARE HELPING TO KEEP THE TEMPERATURES THERE...EVEN IN
MOST OF THE VALLEYS...MORE UNIFORM FROM 45 TO 50 DEGREES.
MEANWHILE...TO THE NORTH...CLEAR SKIES AND LIGHT WINDS HAVE
ALLOWED A DECENT RIDGE TO VALLEY SPLIT TO DEVELOP WITH READINGS
VARYING FROM THE LOWER 50S ABOVE THE INVERSION TO THE LOWER 40S IN
THE SHELTERED SPOTS BELOW IT. DEWPOINTS...IN GENERAL...VARY ACROSS
THE AREA FROM THE LOWER 40S IN THE FAR SOUTH TO THE MID 30S IN THE
NORTH. WINDS THROUGHOUT EAST KENTUCKY ARE LIGHT AND VARIABLE IF
NOT OUTRIGHT CALM.
THE MODELS APPEAR TO BE SETTLING ON A SOLUTION AT MID LEVELS FOR
THE SHORT TERM PORTION OF THE FORECAST. THEY ALL AGREE WITH A
SOUTHERN STREAM WAVE OPENING UP AS IT MOVES INTO THE DEEP SOUTH
TODAY. IT IS THEN JOINED BY A TRAILING NORTHERN STREAM WAVE
DROPPING MAINLY SOUTH THROUGH THE MISSISSIPPI VALLEY. THESE WAVES
WILL MAINTAIN A TROUGH OVER THE NORTHEAST THIRD OF THE NATION
THROUGH THE DAY TODAY. A MORE SUBSTANTIAL WAVE WILL THEN DESCEND
THE WESTERN FLANK OF THE OHIO VALLEY TONIGHT...SHARPENING UP AS IT
MOVES INTO KENTUCKY BY MIDDAY THURSDAY. THIS CLOSED...BUT FAIRLY
QUICK MOVING...LOW WILL PUNCH THROUGH EAST KENTUCKY THURSDAY
AFTERNOON AND EVENING WITH PLENTY OF MID LEVEL ENERGY AND A CORE
OF COLDER 500 MB TEMPS. THE GFS STILL REMAINS THE STRONGEST MODEL
WITH THIS AND ALSO A BIT SLOWER. IT DOES APPEAR THAT THE OTHERS
ARE COMING AROUND TO THIS IDEA...THOUGH...WITH THE NAM
REPRESENTING A GOOD COMPROMISE. ACCORDINGLY...HAVE GONE WITH A
MAINLY NAM12 SOLUTION THROUGH THE SHORT TERM...ALONG WITH THE
WELL ALIGNED HRRR FOR TODAY/S PORTION.
SENSIBLE WEATHER WILL FEATURE A PARTLY TO MOSTLY CLOUDY DAY AS THE
SYSTEM PASSES HARMLESSLY TO THE SOUTH...ROBBING US OF ANOTHER
CHANCE TO GET SOME RAINFALL THAT WOULD GO TOWARD BREAKING THE
RECORD FOR THE MONTH HERE AT JKL. WITH LESS PCPN AND CLOUDS
ANTICIPATED TODAY...TEMPERATURES WILL BE A BIT WARMER THAN
EXPECTED 24 HOURS AGO. ACCORDINGLY...HAVE BUMPED THEM UP INTO THE
MID AND UPPER 60S MOST PLACES. AN APPROACHING SHORTWAVE AT MID
LEVELS TONIGHT WILL BRING IN A DECK OF MID LEVEL CLOUDS THAT WILL
LOWER THROUGH THE NIGHT...BUT SERVE TO KEEP TEMPERATURES RATHER
UNIFORM. SHOWERS WILL BE POSSIBLE BY DAWN IN THE NORTHWEST PARTS
OF THE AREA AS THE SFC REFLECTION OF THAT MID LEVEL WAVE MOVES
INTO KENTUCKY. LAPSE RATES WILL INCREASE THROUGH THE AFTERNOON ON
THURSDAY WITH CLIMBING CAPE AND FALLING LIS AS THE UPPER LOW MOVES
OVERHEAD. AS A RESULT...THUNDERSTORMS WILL BE POSSIBLE THAT
MORNING AND A BETTER BET BY AFTERNOON DUE TO BETTER INSOLATION AND
COLD MID LEVELS. HAVE UPGRADED THE THUNDER CHANCES TO SCATTERED
FROM SLIGHT FOR THURSDAY AFTERNOON AND AM ALSO CONCERNED ABOUT
GRAUPEL FROM ANY STRONGER SHOWER OF STORM SO WILL ADD A MENTION TO
THE FORTHCOMING HWO. THE CLOUDS AND CONVECTION WILL LIKELY KEEP
TEMPS ON THE COOL SIDE THURSDAY DESPITE THE THUNDER CHANCES.
FOR TEMPERATURES/DEWPOINTS/WINDS HAVE STARTED WITH THE SHORTBLEND
GUIDANCE THROUGH THE FIRST PART OF THE FORECAST AND THE SUPERBLEND
AFTER THAT. DID MAKE SOME MINOR ADJUSTMENTS TO THE TEMPERATURES
BASED ON TERRAIN THIS MORNING AND TONIGHT. AS FOR POPS...ENDED UP
SIMILAR TO LOWER GUIDANCE TODAY/TONIGHT AND A BIT HIGHER ON
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 AM EDT WED APR 29 2015
THE EXTENDED PERIOD WILL START OUT WET AND RAINY AS A WEATHER SYSTEM
PUSHES OFF TO OUR EAST THURSDAY NIGHT AND FRIDAY. RUN OF THE MILL
RAIN SHOWERS WILL AFFECT THE AREA AS AN AREA OF LOW PRESSURE ALOFT
MOVES OUT OF THE GREAT LAKES REGION AND ACROSS THE CENTRAL AND
EASTERN OHIO VALLEY. COOLER AIR AND LACK OF INSTABILITY WILL
EFFECTIVELY KILL ANY CHANCES FOR THUNDER. THE RAIN SHOULD BE LIGHT
IN NATURE AND WILL NOT CAUSE ANY HYDRO ISSUES. AFTER LATE FRIDAY
AFTERNOON...THE FORECAST LOOKS DRY AND WARM AS A LARGE AND RATHER
STRONG RIDGE OF HIGH PRESSURE SETTLES OVER THE SOUTHEASTERN CONUS.
THE LONG TERM MODELS DO TRY TO PRODUCE A BIT OF SPOTTY PRECIPITATION
FROM TIME TO TIME DURING THE EXTENDED PERIOD FROM SATURDAY
ONWARD...BUT CONSIDERING THE STRENGTH OF THE RIDGE IN THE
MODELS...AND NO APPRECIABLE SIGNAL FOR PRECIP IN THE MODEL SOUNDINGS
AND TIME HEIGHTS...DECIDED TO KEEP PRECIPITATION OUT OF THE PICTURE
UNTIL THE VERY END OF THE PERIOD...WHEN THE GFS MODEL ATTEMPTS TO
SAG A FRONTAL BOUNDARY SOUTHWARD OUT OF INDIANA...OHIO...AND
ILLINOIS.
TEMPERATURES THE FIRST COUPLE OF DAYS OF THE PERIOD WILL LIKELY BE
SLIGHTLY BELOW NORMAL DUE TO THE INFLUENCE OF CLOUDS AND
PRECIPITATION AND WESTERLY FLOW BEHIND THE DEPARTED WEATHER SYSTEM.
FROM SUNDAY ONWARD...THE WEATHER SHOULD BE MARKEDLY WARMER AS THE
RIDGE OF HIGH PRESSURE SETTLES OVER THE REGION...BRINGING LIGHT
WINDS AND AMPLE SUNSHINE TO THE OHIO AND TENNESSEE VALLEYS. HIGHS ON
EACH OF THESE DAYS WILL LIKELY BE ABOVE NORMAL...WITH MAX READINGS
ON MONDAY TUESDAY POSSIBLE TOPPING OUT IN THE UPPER 70S AROUND THE
AREA. A FEW LOCATIONS ON TUESDAY MAY EVEN TOP 80 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT WED APR 29 2015
EXPECT VFR CONDITIONS THROUGH THE PERIOD. MAINLY HIGH CLOUDS WILL
BE SEEN THROUGH THE REST OF THE NIGHT...WITH A LOWER DECK OF
CLOUDS LIKELY FORMING FROM SOUTH TO NORTH DURING THE DAY
WEDNESDAY...HOWEVER THESE WILL LIKELY HOLD AT AROUND 5K FEET AGL.
SOME SHOWERS MAY THREATEN...THOUGH THEY WILL BE LIKELY OCCUR
SOUTH OF THE BORDER AND FAR FROM ANY TAF SITE. WINDS WILL AVERAGE
AROUND 5 KTS OR LESS THROUGH THE PERIOD...GENERALLY OF VARIABLE
DIRECTION WHEN NOT OUT OF THE NORTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
244 AM EDT WED APR 29 2015
.UPDATE...
ISSUED AT 200 AM EDT WED APR 29 2015
DID A QUICK TOUCH UP TO THE GRIDS FOR THE REST OF THE NIGHT GIVEN
THE HIGH CLOUDS IN THE SOUTH SLOWING THE RADIATIVE COOLING THERE
WHILE THE SHELTERED VALLEYS NORTH OF THE CLOUD LINE HAVE BEEN
ABLE TO DROP OFF TO AROUND 10 DEGREES LOWER THAN THE RIDGES. BASED
ON THE LATEST HRRR AND NAM12 HAVE TAKEN POPS DOWN EVEN MORE INTO
THE MORNING KEEPING THE PCPN OF THE SOUTHERN SFC WAVE TO THE SOUTH
OF KENTUCKY. ALSO FINE TUNED LOW TEMPS AND HOURLY T/TD PER THE
LATEST SHORTBLEND GUIDANCE...OBS...TRENDS...AND CLOUD COVER.
THESE GRID UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1107 PM EDT TUE APR 28 2015
ONE BATCH OF HIGH CLOUDS IS GRADUALLY THINNING ACROSS SOUTHEASTERN
KENTUCKY AND EAST TENNESSEE...WITH ANOTHER BATCH MOVING OUT OF
NORTHERN ALABAMA AND MISSISSIPPI. COOLER VALLEYS HAVE DROPPED OFF
INTO THE MID 40S...SO A FEW UPPER 30S STILL LOOK ON TARGET. DID GO
A BIT MILDER IN THE SOUTHWEST COUNTIES...WITH A SLOWER DROP OFF
THUS FAR. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 755 PM EDT TUE APR 28 2015
HIGH CLOUDS ARE TRYING TO ADVANCE NORTHWARD ACROSS OUR AREA. THE
LATEST SATELLITE AND MODEL TRENDS SUGGEST AREAS ALONG AND NORTH
OF THE MOUNTAIN PARKWAY WILL LIKELY BE MOSTLY CLEAR THROUGH MOST
OF THE NIGHT UNTIL THE UPPER LEVEL SHORT WAVE TROUGH CURRENTLY
SPINNING ACROSS THE ARKLATEX AREA DRAWS CLOSER BY WEDNESDAY
MORNING. AS SUCH...WITH FAIRLY CALM WINDS AND DEW POINTS BACK DOWN
IN THE 30S THIS AFTERNOON...THINK A FEW SHELTERED VALLEYS MAY DIP
BELOW THE 40 DEGREE MARK ONCE AGAIN TONIGHT. HAVE ALSO REMOVED
POPS FOR THE REST OF TONIGHT AS THE LATEST MODELS SUGGEST THAT
EVEN THE FAR SOUTHEAST WILL NOT HAVE ENOUGH MOISTURE TO ALLOW FOR
SHOWERS UNTIL DURING THE DAY ON WEDNESDAY. UPDATES WILL BE
FORTHCOMING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 403 PM EDT TUE APR 28 2015
CLOUDS WILL BE ON THE INCREASE TONIGHT AFTER A CLEAR AND BEAUTIFUL
DAY WHERE TEMPERATURES TOPPED OUT IN THE LOW TO MID 60S...ABOUT 5 TO
10 DEGREES BELOW NORMAL FOR LATE APRIL. TEMPERATURES OVERNIGHT ARE
ALSO EXPECTED TO STAY BELOW NORMAL WITH LOWS FORECASTED IN THE LOW
TO MID 40S. TOMORROW...A LOW PRESSURE SYSTEM WILL PASS TO OUR SOUTH
KEEPING THE MAJORITY OF THE PRECIP OUT OF KY. WITH THIS
SYSTEM...MODELS CONTINUE TO TREND DRIER SO HAVE SUBSTANTIALLY BUMPED
POPS DOWN THROUGH 00Z THURSDAY ONLY ALLOWING CHANCE POPS IN OUR
EXTREME SOUTH AND EASTERN COUNTIES DURING THE AFTERNOON AND EVENING
HOURS. TEMPERATURES TOMORROW AFTERNOON SHOULD TOP OUT IN THE UPPER
60S....WITH CLOUDS INCREASING THROUGHOUT THE DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 410 PM EDT TUE APR 28 2015
THE PERIOD WILL BEGIN WITH A RIDGE EXTENDING FORM PARTS OF THE
EASTERN PACIFIC NORTHEAST INTO THE CENTRAL ROCKIES AND THEN NORTH
INTO THE NORTHERN PLAINS. AN UPPER LEVEL TROUGH IS EXPECTED TO BE
WORKING ACROSS THE SOUTHERN STATES WITH A CLOSED UPPER LOW DROPPING
SOUTH ACROSS THE NORTHERN GREAT LAKES. AT THE SFC...AN AREA OF LOW
PRESSURE IS PROGGED TO BE DEPARTING THE SOUTHEAST US COAST WITH
ANOTHER BROAD REGION OF LOWER PRESSURE EXTENDING FROM THE MID
ATLANTIC STATES INTO THE CENTRAL APPALACHIANS.
FROM WED NIGHT INTO THU NIGHT...THE UPPER LEVEL LOW IS PROGGED TO
DROP SOUTH INTO THE OH VALLEY REGION AND THEN REACH THE PIEDMONT
REGION ALONG THE EASTERN SEABOARD BY DAWN ON FRIDAY. AT THE SAME
TIME...A SHORTWAVE TROUGH WILL MOVE RATHER QUICKLY FROM THE PACIFIC
NORTHWEST EAST NEAR THE US/CANADIAN BORDER AND INTO THE NORTHERN
PLAINS. SHORTWAVE RIDGING IS EXPECTED TO BE IN PLACE BETWEEN THE
SYSTEMS. FRI INTO SATURDAY...THE UPPER LEVEL LOW WILL DEPART TO THE
EAST...WHILE SHORTWAVE RIDGING BUILDS TOWARD THE AREA...BUT DAMPENS.
BY THE END OF THE WEEKEND INTO EARLY NEXT WEEK...THE FLOW WILL TAKE
ON A BIT MORE ZONAL FLAVOR.
BETWEEN THE TROUGH DEPARTING TO OUR SOUTH AND EAST EARLY IN THE
PERIOD AND THE APPROACHING UPPER LEVEL LOW...MUCH OF THE EARLY PART
OF THE PERIOD ON WED NIGHT MAY BE RATHER UNEVENTFUL WITH MID AND
HIGH SOME HIGH CLOUDS MOVING ACROSS THE REGION. THE UPPER LEVEL LOW
WILL BRING MOISTURE AND INCREASING INSTABILITY INTO THE REGION FOR
THU...ESPECIALLY WHEN COMBINED WITH SOME SOLAR INSOLATION DURING THE
DAY. THE MODELS PROJECT CAPE NEARING 500 J/KG OR SO ACROSS THE
WESTERN PART OF THE AREA BY MIDDAY ON THU...WHILE EASTERN LOCATIONS
CAPE MAY NEAR 1000 J/KG. LAPSE RATES SHOULD ALSO GET RATHER STEEP
WHILE FREEZING LEVELS AND WBZ WILL BE RATHER LOW... ON THE ORDER OF
5 TO 6KFT. SOME GRAUPEL OR HAIL MIGHT BE POSSIBLE FROM ANY STRONGER
SHOWERS OR THUNDERSTORMS. WE HAVE CONTINUE WITH SLIGHT CHANCE FOR
THUNDER...ALTHOUGH MORE SCATTERED COVERAGE OF THUNDER MAY NEED TO BE
CONSIDERED FOR THE SOUTH AND EAST. CHANCES FOR SHOWERS WILL LINGER
INTO THE DAY ON FRIDAY UNTIL THE UPPER LOW DEPARTS FURTHER
EAST...ESPECIALLY DURING PEAK HEATING.
OVER THE WEEKEND...THE ECMWF CONTINUES TO BE HIGHER WITH HEIGHTS
ACROSS THE LOCAL AREA...AND MUCH OF THE EASTERN CONUS TRACKING A
SHORTWAVE FURTHER NORTH AND WEST LATE SAT NIGHT INTO SUNDAY. THIS
KEEPS EASTERN KY GENERALLY DRY DURING THE WEEKEND AS COMPARED TO THE
WETTER GFS. FOR THE WEEKEND...WE HAVE CONTINUED TO LEAN MORE TOWARD
PERSISTENCE FROM THE PREVIOUS FORECAST AND RECENT ECMWF RUNS FOR
POPS. ALSO DURING THE WEEKEND...ANOTHER IN A SERIES OF DISTURBANCES
IN THE NORTHERN STREAM WILL TRACK TOWARD THE HUDSON AND JAMES BAY
REGION EARLY IN THE NEW WEEK AND SEND A COLD FRONT SOUTH AND
SOUTHEAST INTO THE GREAT LAKES AT THE END OF THE WEEKEND AND
APPROACHING THE OH VALLEY AROUND THE END OF THE PERIOD. ALTHOUGH
SOME ISOLATED POPS WERE CARRIED IN THE NORTH EARLY IN THE NEW
WEEK...CHANCES FOR CONVECTION APPEAR HIGHER TOWARD THE END OF THE
PERIOD...ULTIMATELY WHEN THE BOUNDARY GETS CLOSER TO THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT WED APR 29 2015
EXPECT VFR CONDITIONS THROUGH THE PERIOD. MAINLY HIGH CLOUDS WILL
BE SEEN THROUGH THE REST OF THE NIGHT...WITH A LOWER DECK OF
CLOUDS LIKELY FORMING FROM SOUTH TO NORTH DURING THE DAY
WEDNESDAY...HOWEVER THESE WILL LIKELY HOLD AT AROUND 5K FEET AGL.
SOME SHOWERS MAY THREATEN...THOUGH THEY WILL BE LIKELY OCCUR
SOUTH OF THE BORDER AND FAR FROM ANY TAF SITE. WINDS WILL AVERAGE
AROUND 5 KTS OR LESS THROUGH THE PERIOD...GENERALLY OF VARIABLE
DIRECTION WHEN NOT OUT OF THE NORTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JVM
LONG TERM...JP
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 AM EDT WED APR 29 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 359 PM EDT TUE APR 28 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS INDICATE UPSTREAM SHORTWAVE
ENERGY SPLITTING WITH ONE SHORTWAVE DIVING SE THROUGH CENTRAL MN AND
ANOTHER MORE SHEARED OUT SHORTWAVE MOVING EAST THROUGH NRN MN AS IT
APPROACHES LAKE SUPERIOR. THE ENERGY SPLIT RESULTS IN WEAKENING
DYNAMICS OUT AHEAD OF SHORTWAVE TROUGH AS DEPICTED BY WEAKENING MID-
LVL Q-VECT CONVERGENCE. AND THIS PARTLY EXPLAINS WHY LINE OF SHRA
APPROACHING FM THE WEST IS ALSO WEAKENING AND BREAKING APART AS
NOTED ON REGIONAL RADAR LOOP.
TONIGHT...SHORTWAVE TROUGH APPROACHING FROM MN IS EXPECTED TO CROSS
LAKE SUPERIOR TONIGHT. MODEL Q-VECT CONV INDICATES BEST Q-VECT CONV
SPLITTING NORTH AND SOUTH OF CWA SO WOULD EXPECT WEAKENING TREND TO
CONTINUE WITH APPROACHING LINE OF SHRA THIS EVENING. EXPECT THE DRY
FCST TO CONTINUE ESPECIALLY GIVEN THE DRY AIRMASS IN PLACE.
SECONDARY SHORTWAVE NOW MOVING NW ONTARIO WL THEN BEGIN DIGGING MORE
SHARPLY TO THE S TONIGHT WITH MODELS SUGGESTING A MID LEVEL LOW
BEGINNING TO CLOSE OFF JUST N OF LAKE SUPERIOR LATE TONIGHT. THIS
SHOULD SUPPORT AN EXPANSION OF PCPN N AND E OF LAKE SUPERIOR
TONIGHT...CLOSER TO GREATEST HEIGHT FALLS. PCPN MAY TRY TO DEVELOP S
INTO ERN UPPER MI...BUT LACK OF DEEP FORCING SUGGESTS MAINLY DRY
WEATHER SHOULD CONTINUE THRU THE NIGHT. EXPECT LOWS TONIGHT IN THE
30S UNDER PARTLY TO MOSTLY CLOUDY SKIES.
WEDNESDAY...CLOSED LOW AND ASSOC MID-LVL TROF CONTINUES TO DESCEND
SOUTH OVER ERN UPPER MI. 12Z NAM SOUNDING FOR KERY SHOWS SHALLOW LOW-
LVL MOISTURE EXTENDING TO 7-8 KFT BUT REMAINING BELOW -10C ISOTHERM.
WOULD EXPECT ONLY SPRINKLES AT BEST FOR ERN COUNTIES (POSSIBLY AIDED
BY UPSLOPE NRLY FLOW) AS BEST SYNOPTIC FORCING/Q-VECT CONV AND
DEEPER MOISTURE REMAINS EAST OF FCST AREA. N WINDS OF 10-15MPH
GUSTING TO 20MPH WILL KEEP LAKE SUPERIOR SHORELINE LOCATIONS COOL
WITH HIGHS ONLY REACHING THE 40S. FARTHER INLAND HIGHS COULD
REACH INTO THE 50S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 316 PM EDT TUE APR 28 2015
OVERALL...LITTLE CHANGES IN THE FORECAST THOUGHTS OVER THE LAST
24HRS...WITH THE REGION SEEING LIMITED PRECIPITATION CHANCES
THROUGH SUNDAY AND A TRANSITION TO ABOVE NORMAL TEMPERATURES. THIS
TRANSITION WILL BE LED BY AN UPPER RIDGE THAT WILL BUILD OVER THE
GREAT LAKES REGION ON THURSDAY NIGHT WHILE AN UPPER TROUGH BECOMES
ESTABLISHED OVER WESTERN CANADA. THIS WILL PLACE THE AREA UNDER
ZONAL FLOW FRIDAY INTO THE WEEKEND...WITH WEAK SHORTWAVES AND
SURFACE TROUGHS LEADING TO LOW CHANCES FOR PRECIPITATION.
BEFORE THAT UPPER RIDGE MOVES INTO THE AREA ON THURSDAY NIGHT...THE
START OF THE LONG TERM FORECAST WILL SEE A STRONG SHORTWAVE DIVING
SOUTH-SOUTHEAST ACROSS THE GREAT LAKES REGION. THE 700-500MB LOW
ASSOCIATED WITH THIS FEATURE WILL TRACK ACROSS EASTERN UPPER
MICHIGAN AND SHOULD KEEP ANY SHOWERS ASSOCIATED WITH THE SHORTWAVE
TO THE EAST OF A LINE FROM MUNISING TO MANISTIQUE. IT DID APPEAR
THAT THERE MAY BE ENOUGH NORTHERLY FLOW UPSLOPE HELP TO PRODUCE A
FEW SHOWERS/DRIZZLE OVER THE NORTH CENTRAL (NOT COLD ENOUGH FOR ICE
CRYSTALS AND SNOW)...SO DID ADD A MENTION OF RAIN TO THAT AREA FOR
WED NIGHT INTO THURS MORNING. THE DISTURBANCE WILL QUICKLY MOVE
SOUTH OF THE AREA WEDNESDAY NIGHT INTO THURSDAY...ALLOWING THE UPPER
RIDGE TO BUILD EAST INTO THE UPPER GREAT LAKES REGION FROM THE
NORTHERN PLAINS AND SOUTHERN CANADA. THAT WILL LEAD TO DRIER AIR
WORKING INTO THE AREA AND IN TURN DECREASING CLOUDS FROM WEST TO
EAST ON THURSDAY. EXPECT TEMPERATURES TO STILL REMAIN BELOW
NORMAL...ESPECIALLY OVER THE NORTH WITH THE COOL AIR COMING OFF LAKE
SUPERIOR.
FRIDAY WILL FEATURE A NICE START TO THE DAY IN THE U.P. WITH SUNNY
CONDITIONS ALLOWING TEMPERATURES TO WARM INTO THE 50S AND 60S. THE
NEXT DISTURBANCE (SLIDING EAST ALONG THE US/CANADIAN BORDER ON THE
LEADING EDGE OF THE UPPER TROUGH BECOMING ESTABLISHED IN WESTERN
CANADA WILL MOVE INTO WESTERN UPPER MICHIGAN IN THE AFTERNOON AND
THEN THE REST OF THE CWA THROUGH EARLY EVENING. THIS WILL LEAD TO
INCREASING CLOUDS DURING THE AFTERNOON. LIKE THE SHORTWAVE AND FRONT
THAT WILL BE MOVING THROUGH THE AREA THIS AFTERNOON/TONIGHT...IT
WILL BE RUNNING INTO EXISTING DRY AIR AND ALSO BECOMING SHEARED OUT.
THUS...EXPECT THE SYSTEM/PRECIPITATION TO DIMINISH AS IT SHIFTS INTO
THE WESTERN U.P. WILL CONTINUE TO SHOW SLIGHT CHANCE POPS OVER THE
WEST IN THE AFTERNOON AND THEN DIMINISHING AS IT SHIFTS EAST OVER
THE REST OF THE CWA IN THE EVENING.
BEHIND THAT DISTURBANCE...ZONAL FLOW BECOMES ESTABLISHED OVER THE
NORTHERN CONSUS AND EXPECT THAT TO LEAD TO ABOVE NORMAL
TEMPERATURES FOR MUCH OF THE CWA. ECMWF HAS BEEN CONSISTENT (OVER
THE LAST 6-8 RUNS) WITH HIGHS IN THE UPPER 60S TO LOWER 70S ON
SATURDAY AT KSAW/KIWD/KIMT AND A FEW DEGREES WARMER FOR SUNDAY.
THUS...WILL TREND THEIR FORECASTS UP TOWARDS THAT IDEA FOR BOTH OF
THOSE DAYS. WITH WINDS GENERALLY LIGHT...SHOULD SEE LAKE BREEZES
DEVELOP ON SATURDAY. WILL NEED TO KEEP AN EYE ON A DISTURBANCE
FORECAST TO TRACK EAST OUT OF THE CENTRAL ROCKIES ON SATURDAY. AT
THIS POINT...IT LOOKS TO STAY TO THE SOUTH OF THE AREA...BUT THERE
HAVE BEEN SOME INDICATIONS THAT IT MAY SLIDE NORTH AND AFFECT THE
AREA ON SUNDAY. OTHERWISE...THE DEPARTING SURFACE RIDGE TO THE EAST
WILL LEAD TO LIGHT SOUTHERLY FLOW DEVELOPING ON SUNDAY.
THE BEST OPPORTUNITY FOR RAIN WILL COME SUNDAY NIGHT INTO MONDAY
MORNING...AS THE UPPER TROUGH OVER THE CANADIAN ROCKIES SHIFTS EAST
AND INTERACTS WITH WEAK DISTURBANCES LIFTING NORTHEAST OUT OF THE
CENTRAL/SOUTHERN ROCKIES. WILL FOCUS ON THIS TIME FOR THE BEST RAIN
CHANCES AND TREND POPS UP BEFORE DIMINISHING THEM ON MONDAY
AFTERNOON AS THE WAVES DEPART. STILL COULD SEE SOME SHOWER LINGERING
INTO MONDAY NIGHT OR EVEN TUESDAY MORNING DEPENDING ON HOW QUICKLY
THE UPPER TROUGH AXIS DEPARTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 130 AM EDT WED APR 29 2015
DRY AIR WILL PERSIST IN THE LOWER LEVELS MAINTAINING VFR
CONDITIONS THROUGH THE FORECAST PERIOD. NORTH WINDS WILL
LIKELY GUST OVER 15 KT AT KCMX AND KSAW ON WED AHEAD OF HIGH PRES
BUILDING DOWN FROM HUDSON BAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT TUE APR 28 2015
WINDS WILL BE LIGHT...UNDER 15KT...AS A VERY WEAK LOW PRES TROF
PASSES THE AREA THIS EVENING. IN ITS WAKE... ANOTHER HIGH PRES WILL
BUILD OVER HUDSON BAY AND EXTEND A RIDGE S INTO THE WRN GREAT LAKES
WED/THU. AS THE HIGH BEGINS RIDGING S INTO THE UPPER LAKES LATE
TONIGHT/WED...NNW WINDS OVER ERN LAKE SUPERIOR WILL LIKELY GUST TO
AROUND 20KT. WINDS WILL BE LIGHTER OVER THE W. WITH WEAK PRES
GRADIENT OVER THE UPPER LAKES THU THRU SAT...WINDS SHOULD BE
LIGHT...MOSTLY UNDER 15KT. A LOW PRES TROUGH APPROACHES FROM THE
WEST LATE SAT NIGHT/SUN BUT IT LOOKS WEAK AS WINDS SHOULD REMAIN BLO
20 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1223 AM CDT WED APR 29 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT TUE APR 28 2015
AT 330 PM...A VARIETY OF WEATHER WAS OCCURRING ACROSS THE CWA.
SOME SPOTTY SHOWERS HAD DEVELOPED BEHIND THE WEAK COLD FRONT
THAT MOVED THROUGH EARLIER TODAY. THE 4KM NMM WRF...AS WELL AS
THE 18Z NAM AND THE HRRR ALL INDICATED THE POTENTIAL FOR SOME
SHOWER DEVELOPMENT IN THE AREA OF HIGHER MOISTURE LINGERING
BEHIND THE FRONT.
THE SHORTWAVE RESPONSIBLE FOR THE AREA OF SHOWERS AND THE VORT MAX
LOCATED TO THE SOUTHWEST OF THE AREA WILL GRADUALLY MOVE OFF TO THE
SOUTH AND EAST AS THE EVENING WEARS ON...BRINGING AN END TO THE THREAT
OF SHOWERS ACROSS THE SOUTHEASTERN HALF OF THE CWA. TEMPS OVERNIGHT
WILL GENERALLY DROP INTO THE 30S WITH A FEW 20S POSSIBLE IN LOW
LYING LOCATIONS. OVERALL...SKIES ARE EXPECTED TO CLEAR OVERNIGHT.
ON WEDNESDAY...A CLOSED LOW WILL DIVE SOUTHWARD INTO THE LAKE
SUPERIOR REGION BY EVENING. THIS WILL CAUSE A BACK DOOR SURFACE
COLD FRONT TO PUSH INTO THE CWA FROM THE NORTHEAST. HIGHS WILL
ONCE AGAIN CLIMB INTO THE 60S FOR DAYTIME HIGHS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 PM CDT TUE APR 28 2015
MILD TEMPERATURES FOR THE REST OF THE WEEK INTO THE WEEKEND AS THE
PATTERN TURNS MORE ACTIVE. THERE WILL BE A WIDESPREAD CHANCE FOR
RAIN ON FRIDAY AS COLD FRONT MOVES THROUGH WITH OCCASIONAL CHANCES
THROUGHOUT THE REST OF THE PERIOD AS THE UPPER LEVEL PATTERNS SHIFTS
TO A MORE ZONAL FLOW LEADING TO WEAK FAST-MOVING IMPULSES MOVING
ACROSS THE REGION.
THURSDAY...DRY AND MILD UNDER A MID-LEVEL RIDGE AXIS. LIGHT WINDS
WILL PREVENT CRITICAL FIRE WEATHER CONDITIONS FROM DEVELOPING...BUT
RELATIVE HUMIDITY VALUES MAY FALL TO 20 TO 30 PERCENT IN THE
AFTERNOON. MOSTLY SUNNY. HIGHS MID 60S TO NEAR 70S INLAND...WITH A
LAKE BREEZE LIMITING TEMPS TO THE 50S BY LAKE SUPERIOR...PERHAPS AS
COLD AS THE MID 40S ALONG THE NORTH SHORE FROM SILVER BAY NORTH.
THURSDAY NIGHT AND FRIDAY...A COLD FRONT WILL APPROACH FROM THE
WEST. THIS WILL RESULT IN INCREASED CLOUDINESS AND A CHANCE FOR RAIN
FRIDAY...MOVING ACROSS FROM WEST TO EAST SIMILAR TO TODAY /TUES/
BUT WITH MORE INTENSE RAINFALL. TOTAL PRECIP WILL AMOUNT TO AROUND A
TENTH OF AN INCH. ECMWF/GEM A BIT FASTER THAN THE GFS...BUT IN
GENERALLY THINK THE RAIN WILL BE ACROSS NORTHEAST MINNESOTA IN THE
MORNING INTO NORTHWEST WISCONSIN IN THE AFTERNOON. LOWS TUESDAY
NIGHT NEAR FREEZING WHERE SKIES REMAIN CLEAR OVERNIGHT IN THE
ARROWHEAD REGION...ELSEWHERE IN THE MID/UPPER 30S. HIGHS
COOLER...BUT STILL ABOVE NORMAL IN THE MID 50S BY THE LAKE TO MID
60S ELSEWHERE.
SAT/SUN/MON/TUES...BEHIND THIS FRONT ZONAL TO NORTHWESTERLY FLOW
DEVELOPS AT MID/UPPER LEVELS RESULTING A SERIES OF WEAK DISTURBANCES
MOVING ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST. THERE WILL BE A
CHANCE FOR PRECIP MOST DAYS...BUT NO DAY IS EXPECTED TO BE A TOTAL
WASHOUT. AT THIS POINT SUNDAY THROUGH EARLY MONDAY LOOKS TO BE THE
BEST CHANCE FOR RAINFALL...BUT WITH THIS TYPE OF PATTERN IT IS
DIFFICULT TO NAIL DOWN TIMING OF ANY INDIVIDUAL SYSTEM. TEMPS WARM
DUE TO SOME LOW LEVEL RIDGING THAT DEVELOPS OVER THE WEEKEND
RESULTING IN WEST/SOUTHWEST WINDS AND WARM AIR ADVECTION...WITH
HIGHS IN THE LOW 70S ON SATURDAY AND SUNDAY...IN THE 60S BY LAKE
SUPERIOR. EARLY NEXT WEEK THE LOW LEVEL FLOW TURNS MORE
NORTHWESTERLY RESULT IN COOLER TEMPS...IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1222 AM CDT WED APR 29 2015
THE VFR CONDITIONS OVER NE MINNESOTA AND NW WISCONSIN WILL CONTINUE
THROUGH WEDNESDAY AS HIGH PRESSURE MOVES THROUGH THE REGION. LIGHT
NORTHERLY WINDS AND MOSTLY CLEAR SKIES ARE EXPECTED THROUGH THIS
TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 35 55 36 60 / 0 0 20 30
INL 35 68 41 65 / 0 0 40 30
BRD 39 68 44 68 / 0 0 30 30
HYR 34 61 35 66 / 0 0 0 30
ASX 33 55 31 65 / 0 0 0 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM...JJM
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
630 PM CDT THU APR 30 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 347 PM CDT THU APR 30 2015
A COLD FRONT IS VERY SLOWLY MOVING SOUTHEAST ACROSS THE PANHANDLE
INTO WESTERN SOUTH DAKOTA LATE THIS AFTERNOON. THIS FRONT WILL
CONTINUE TO SLOWLY MOVE SOUTHEAST TONIGHT...AND ROUGHLY EXTEND FROM
MCCOOK TO BROKEN BOW ON NORTHEASTWARD BY EARLY FRIDAY MORNING.
MOISTURE IS LIMITED...HOWEVER WHAT MOISTURE THERE IS WILL POOL IN
THE VICINITY OF THE FRONT. A SOUTHERLY LOW LEVEL JET WILL INCREASE
BY MID EVENING ACROSS WESTERN KANSAS...WITH THE NOSE POINTED AT
SOUTHWEST NEBRASKA AND THE SANDHILLS WHERE THE FRONT WILL BE SLOWLY
MOVING SOUTHEAST. FRONTOGENESIS WILL INCREASE DRAMATICALLY IN THE
850-700 MB LAYER DURING THIS TIME...WITH BETWEEN 500-1000 J/KG MID
LEVEL CAPE. EXPECT THAT AT LEAST SCATTERING OF SHOWERS AND
THUNDERSTORMS WILL RESULT. WILL KEEP POPS FAIRLY LOW DUE TO THE
LIMITED MOISTURE...BUT A SMALL CONCENTRATED AREA OF PRECIPITATION
COULD RESULT NEAR THE NOSE OF THE LOW LEVEL JET WITHIN AREA OF
INCREASING MID LEVEL FRONTOGENESIS.
FRONT SETTLES TO THE SOUTH ACROSS NORTHERN KANSAS THROUGH SOUTHEAST
NEBRASKA FRIDAY. A PERSISTENT AREA OF MID LEVEL FRONTOGENESIS
REMAINS JUST NORTH OF THE FRONT ACROSS CENTRAL AND SOUTHWEST
NEBRASKA...AND WILL CONTINUE AT LEAST A SLIGHT CHANCE FOR SHOWERS
AND THUNDERSTORMS FOR THESE AREAS. OTHERWISE AIRMASS MILD BEHIND THE
FRONT...AND 850 MB TEMPERATURES SUPPORT HIGHS IN THE LOW TO MID
70S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 347 PM CDT THU APR 30 2015
A FAIRLY ACTIVE PERIOD IS EXPECTED AS THE UPPER RIDGE BUILDS OVER
THE SOUTHWEST U.S. DRIVING WEAK UPPER WAVES THROUGH THE CENTRAL AND
NORTHERN PLAINS. THIS PATTERN WILL RESULT IN AT LEAST A SLIGHT
CHANCE OF THUNDERSTORMS EACH DAY.
FRIDAY EVENING...A BOUNDARY MAKES ITS WAY INTO NORTHERN AND
WESTERN NEBRASKA. THE 0-6KM BULK SHEAR IS EXPECTED TO BE 30-50KT
WITH CONVECTIVE POTENTIAL ENERGY OF 800-1000J/KG IN CENTRAL...SOUTH
CENTRAL AND SOUTHWEST NEBRASKA. AS A RESULT...WE WOULD EXPECT
THUNDERSTORMS TO BE CONFINED TO AREAS SOUTH AND EAST OF A BROKEN
BOW-NORTH PLATTE-OGALLALA LINE.
ON SATURDAY...A LOW LEVEL TRAJECTORY DEVELOPS FROM THE TEXAS GULF
COAST AND FROM THE PACIFIC SOUTHWEST TO THE HIGH PLAINS. THIS WILL
RESULT IN A SLIGHT INCREASE IN PRECIPITABLE WATER TO ABOUT 0.75
INCH. THEN...ANOTHER FRONT COMES THROUGH AND CREATES ENOUGH LIFT TO
INITIATE SOME CONVECTION SATURDAY AFTERNOON AND EARLY EVENING IN THE
NEBRASKA SANDHILLS AND INTO SOUTHWEST NEBRASKA. THE CHANCES FOR AT
LEAST MARGINALLY LARGE HAIL ARE A LITTLE HIGHER WITH SURFACE-BASED
CONVECTIVE POTENTIAL ENERGY 1500-2000J/KG AND 0-6KM BULK SHEAR OF
35-40KT.
PATTERN TRANSITIONS FROM A BROAD ZONAL FLOW OVER THE WEEKEND TO A
HIGHER AMPLITUDE PATTERN OF DEVELOPING LONG WAVE TROUGH OVER THE
WEST COAST WITH A RIDGE OVER THE SOUTHEAST. TWO MAIN AREAS OF LOW
PRESSURE AND ASSOCIATED PV ANOMALIES EVOLVE OVER THE WEST...THE
STRONGER OF WHICH APPROACHES THE PAC NW BY MONDAY EVENING...THOUGH
THE SECOND UPPER LEVEL LOW MOVES ONSHORE OVER BAJA AND SO CAL SUNDAY
NIGHT INTO MONDAY IS SLIGHTLY MORE ANOMALOUS FOR THIS PERIOD OF
TIME...AND BECAUSE OF THE MORE SOUTHERN LATITUDE. EVENTUAL EVOLUTION
OF THE TWO INDIVIDUAL SYSTEMS BECOMES QUITE DIFFERENT IN THE MAIN
MID RANGE DETERMINISTIC MODELS THROUGH THE MIDDLE OF NEXT WEEK.
WITHING THE GFS ENSEMBLE MEMBERS THERE BECOMES MUCH GREATER
UNCERTAINTY BY THE END OF THE PERIOD. DESPITE THIS...BOTH GFS AND
ECMWF ARE FAIRLY WET FOR THE EASTERN TWO-THIRDS OF NEBRASKA. THIS IS
A RESULT OF A REASONABLY LONG PERIOD OF MOIST...SERLY FLOW AHEAD OF
THE NEGATIVELY TILTED UPPER LOW MOVING NORTHEAST FROM THE
SOUTHWESTERN U.S. AND A LARGE NEGATIVELY TILTED UPPER RIDGE
DOWNSTREAM...LEADING TO ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES
TUE THROUGH THUR.
FORECAST WILL REMAIN A BLEND OF MODELS IN THE OUTER PERIODS...THOUGH
CONFIDENCE IN A LONG DURATION WIDESPREAD RAIN EVENTS ARE BELOW
AVERAGE AT THIS TIME. THIS IS BECAUSE IN A CONVECTIVE ENVIRONMENT
SUCH AS THIS AND WITH A SIGNIFICANT UPPER LOW EJECTING ONTO THE
PLAINS...VIGOROUS CONVECTION WOULD LIKELY BE FAVORED ALONG MORE
SIGNIFICANT BOUNDARIES...SUCH AS THE STRONG DRYLINE THAT DEVELOPS IN
THE TUESDAY INTO WED TIME FRAME FROM TX INTO OK. BY THURSDAY THE
DRYLINE DEVELOPS NWD DUE TO THE MORE NWD MOVEMENT OF THE UPPER LOW.
HOWEVER...AS MENTIONED EARLIER WITH THE ANOMALOUS PRECIPITABLE WATER
VALUES /EXCEEDING ONE INCH/ AND ALSO WITH EARLY FLOW NORTH OF A
STALLED FRONT ON THE NORTHERN SIDE OF THE SYSTEM...RAIN SHOWERS WITH
AT LEAST ISOLATED THUNDER SEEMS PLAUSIBLE THROUGH MID WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 630 PM CDT THU APR 30 2015
THE SHOWER AND THUNDERSTORM ACTIVITY DEVELOPING NEAR KVTN IS
EXPECTED TO DRIFT EAST AND SOUTHEAST VERY SLOWLY OVERNIGHT.
ACTIVITY WOULD LIKELY BECOME MORE NUMEROUS AND AFFECT THE AREA
SOUTHWEST TO KLBF ACCORDING TO THE HRRR MODEL. BY MORNING THE
ACTIVITY WILL BE EAST OF HIGHWAY 83 BUT POSSIBLY LINGER ACROSS
CUSTER COUNTY ALL MORNING.
ADDITIONAL REDEVELOPMENT IS POSSIBLE FROM KIML EAST NORTHEAST TO
KBBW DURING THE AFTN.
THE SREF SUGGESTS THE POTENTIAL FOR A PERIOD OF MVFR CIGS FROM
KIML TO KLBF FOR A FEW HOURS FRIDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TAYLOR
LONG TERM...SPRINGER/JWS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1019 PM EDT THU APR 30 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE SLOWLY UP THE CAROLINA COAST THROUGH
TONIGHT BEFORE FINALLY MOVING AWAY FROM THE AREA DURING FRIDAY.
THE RISK FOR SHOWERS AND SOME THUNDERSTORMS WILL REMAIN THROUGH
FRIDAY. HIGH PRESSURE WILL BUILD ACROSS THE AREA FOR THE WEEKEND
AND INTO THE FIRST PART OF NEXT WEEK. THE DRY WEATHER AND
RETURNING SUNSHINE WILL ALLOW TEMPERATURES TO RETURN TO SEASONABLE
LEVELS BY THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1015 PM THURSDAY...SHOWERS BREAKING OUT ACROSS THE FORECAST
AREA AS AN UPPER DISTURBANCE DROPS SE ACROSS THE CAROLINAS. SOME
LIGHTNING BEING DETECTED OVER PENDER COUNTY BUT OTHERWISE WE ARE
SEEING JUST ISOLATED TO WIDELY SCATTERED SHOWER ACTIVITY. OTHER
THAN THE LIGHTNING THIS ACTIVITY IS FAIRLY BENIGN AND WILL
CONTINUE ON AND OFF THROUGH THE EVENING HOURS. FORECAST IN GOOD
SHAPE...PREVIOUS DISCUSSION FOLLOWS:
LOW PRESSURE CENTERED SOUTH OF CAPE HATTERAS SHOULD SLOW TONIGHT
AS A POWERFUL UPPER LEVEL DISTURBANCE DIVES SOUTHWARD FROM INDIANA
INTO NORTH CAROLINA. ALTHOUGH LOW- LEVEL BAROCLINICITY IS VERY
WEAK...A FAVORABLY ORIENTED JET STREAK OFFSHORE PLUS INCOMING
VORTICITY WITH THE DISTURBANCE SHOULD LEAD TO SLOWLY FALLING
PRESSURES OFFSHORE.
AWAY FROM EXTREME EASTERN NC (INCLUDING WILMINGTON) THERE HAS BEEN
PLENTY OF SUNSHINE TODAY. TEMPERATURES RISING INTO THE 70S PLUS
RATHER COOL TEMPERATURES ALOFT HAVE HELPED GENERATE SURFACE-BASED
CAPE AS LARGE AS 500 J/KG ALONG AND WEST OF I-95. SO FAR THIS HAS
RESULTED IN AN EXPANSIVE CUMULUS FIELD ACROSS WESTERN NC PLUS A
SMATTERING OF SHOWERS. AS 800-600 MB TEMPERATURES FALL FURTHER THIS
EVENING AND THE FIRST OF SEVERAL UPPER DISTURBANCES ARRIVES FROM THE
WEST...THE POTENTIAL FOR SHOWERS WILL EXPAND ACROSS SOUTHEASTERN
NORTH CAROLINA AND NORTHERN PORTIONS OF THE PEE DEE REGION. I HAVE
DECIDED NOT TO INCLUDE THUNDER IN THE FORECAST AS IT APPEARS AN
INVERSION BETWEEN 500-600 MB SHOULD BE SUFFICIENTLY STRONG TO CAP
OFF UPDRAFTS BEFORE THEY BECOME COLD ENOUGH ALOFT. 12Z MODELS HAVE
BACKED OFF A LITTLE COMPARED TO THEIR 00Z/06Z COUNTERPARTS WITH THE
SOUTHERN EXTENT OF PRECIPITATION...AND THIS TREND IS ECHOED BY THE
LAST FEW HRRR RUNS AS WELL.
BY LATE TONIGHT THE MAIN UPPER LOW WILL WOBBLE INTO CENTRAL NORTH
CAROLINA. NEAR AND NORTH OF THE LOW IS WHERE UNSTABLE CONDITIONS
SHOULD CONTINUE OVERNIGHT DUE TO COLD AIR ALOFT. OUR FORECAST AREA
SHOULD LARGELY REMAIN SOUTH OF THE INSTABILITY...SO ASIDE FROM
MAINTAINING 30-40 PERCENT POPS ACROSS LUMBERTON-ELIZABETHTOWN-BURGAW
I HAVE CUT POPS TO 10-20 POPS OVERNIGHT...WITH LOWS GENERALLY IN THE
LOWER 50S EXCEPT MID 50S AT THE BEACHES.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...A STRONG UPPER LOW WILL CUT BY TO OUR NORTH
ON FRIDAY. EVEN SO WE SHOULD SEE VERY STRONG PVA AND HEIGHT FALLS
LOCALLY AND SOME LIGHT SHOWERS SEEM LIKELY OVER NORTHERN ZONES.
STILL TOUGH TO RULE OUT THUNDER WITH UPWARDS OF 600J/KG OF CAPE
DEVELOPING. SOME OF THIS INSTABILITY MAY GO SUFFICIENTLY INTO THE
HAIL GROWTH LAYER FOR SOME PEA SIZED HAIL TO REACH THE GROUND
UNDERNEATH THE DEEPER CONVECTIVE CELLS. CLOUD COVER WILL MEANWHILE
BRING ONE LAST DAY OF CONSIDERABLY COOL TEMPS WITH HIGHS STUCK IN
THE 60S. DRY AIR MOVES IN FRIDAY NIGHT INTO SATURDAY. THERE IS
HOWEVER ONE TRAILING VORT AND WRAPAROUND MOISTURE ON SATURDAY AND
SOME GUIDANCE HINTING AT PRECIP OVER CAPE FEAR/COASTAL NC ZONES.
FEEL IF ANYTHING AT ALL WILL BE JUST NON-MEASURABLE AND HAVE KEPT
THE FORECAST DRY AT THIS TIME. THE DECREASED CLOUD COVER WILL
ALLOW FOR A NICE BUMP IN TEMPERATURES COME SATURDAY BUT THE
NORTHERLY FLOW COMPONENT THROUGH A DEEP LAYER WILL STILL KEEP US A
TAD BELOW CLIMO.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...BERMUDA HIGH AND MID LEVEL RIDGE BUILDING OVER
THE SOUTHEAST WILL KEEP THE REGION DRY DURING THE PERIOD WITH
TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO. AS FAR AS THE TROPICAL
WAVE/LOW COMBO EMERGING FROM THE BAHAMAS NEXT WEEK GOES THE LATEST
MEDIUM RANGE GUIDANCE HAS FALLEN OUT OF FAVOR WITH THIS SCENARIOS.
NEARLY ALL OF THE GUIDANCE (INCLUDING THE ENSEMBLES) NOW SHOW A
SHEARED OUT SURFACE WAVE MOVING EAST-NORTHEAST...REMAINING WELL
SOUTHEAST OF THE COAST. LATER IN THE PERIOD CANNOT RULE OUT AN
ISOLATED SEA BREEZE SHOWER AS LOW LEVEL MOISTURE INCREASES BUT
COVERAGE WILL BE QUITE LIMITED AND DOES NOT WARRANT INCLUSION OF POP
GREATER THAN 15 AT THIS TIME.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...VFR EXPECTED THIS EVENING WITH ISOLATED SHOWERS.
SHOWERS WILL REMAIN POSSIBLE OVERNIGHT MAINLY KILM TO KLBT AS A
STRONG UPPER LOW APPROACHES. THERE IS MODERATE CONFIDENCE IFR WILL
DEVELOP AFTER MIDNIGHT AT KLBT...DEVELOPING INTO KILM IN THE PRE-
DAWN HOURS...REACHING KCRE AROUND DAYBREAK. IFR IS POSSIBLE AT
KMYR AND KFLO AROUND SUNRISE...BUT CONFIDENCE IS HIGHER CIGS WILL
BE MVFR WITH ANY IFR OF A SHORT TEMPO DURATION.
CIGS IMPROVE TO MVFR THEN VFR DURING THE MORNING HOURS AS WINDS
BECOME NW 10-12 KT. SHOWERS WILL CONTINUE...BUT STILL MOST LIKELY
NEAR KILM. VFR EXPECTED IN THE AFTERNOON...BUT MVFR CIGS WILL BECOME
POSSIBLE AGAIN AT KILM AND KLBT AS WRAP AROUND MOISTURE SWINGS IN
FROM THE NORTH. WINDS WILL BE NW-N FRIDAY...GUSTING TO 20-25 KTS
BY AFTERNOON.
EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 PM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
LOW PRESSURE HAS MOVED SOUTH OF HATTERAS THIS AFTERNOON BUT
SHOULD SLOW TONIGHT AS A STRONG UPPER LEVEL DISTURBANCE APPROACHES
FROM THE WEST. THIS DISTURBANCE WILL CREATE A ZONE OF WEAKENED
PRESSURE GRADIENT ACROSS EASTERN NORTH CAROLINA TONIGHT...WHILE TO
THE SOUTH ACROSS SOUTH CAROLINA THE GRADIENT SHOULD GRADUALLY
TIGHTEN WITH INCREASING WESTERLY WINDS EXPECTED. BY DAYBREAK WINDS
JUST EAST OF WINYAH BAY/GEORGETOWN COULD REACH 15-20 KT. THE
VARIOUS COMPUTER MODELS HAVE DIFFERING POSITIONS OF WHERE THE
BOUNDARY BETWEEN THESE STRONGER WEST WINDS AND LIGHTER NORTH WINDS
CLOSER TO THE LOW WILL SET UP...AND I HAVE FOLLOWED THE 12Z GFS AS
A GUIDE TONIGHT.
SEAS CURRENTLY RANGE FROM 2-3 FEET INSIDE 20 MILES OF SHORE...TO 4
FEET OUT AT THE FRYING PAN SHOALS BUOY. SEAS MAY SUBSIDE A BIT THIS
EVENING BUT SHOULD INCREASE AGAIN OVERNIGHT...ESPECIALLY SOUTH OF
CAPE FEAR...DUE TO THE INCREASING WIND SPEEDS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...LOW PRESSURE OFF CAPE HATTERAS WILL BE SLOW
TO MOVE ON FRIDAY, ENERGIZED IN PART BY A STRONG LOW IN THE MID
LEVELS. THIS FEATURE WILL STRENGTHEN VERTICAL MIXING MORE THAN THE
ACTUAL SURFACE PRESSURE GRADIENT, POSSIBLY ENOUGH FOR SOME
ADVISORY-WORTHY 25KT WINDS OVER MAINLY JUST OUR NORTHERNMOST ZONE-
MAINLY FRIDAY NIGHT. ALL MODELS ARE NOT CONVINCED OF THIS AND
THERE IS STILL A BIT OF TIME TO IRON OUT THE UNCERTAINTY SO ONE
WILL NOT BE RAISED AT THIS TIME. THE LOW WILL BE GRADUALLY PULLING
AWAY TO THE NORTHEAST ON SATURDAY. WINDS LOCALLY WILL REMAIN N TO
NW AND SLOWLY SUBSIDE. THERE MAY EVEN BE A BIT OF BACKSWELL FROM
THE OFFSHORE STORM AS IT GROWS A BIT LARGER IN SIZE.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...SURFACE HIGH MOVING OFF THE COAST SUN
MORNING WILL SETUP NEAR BERMUDA SUN EVENING AND REMAIN IN PLACE
THROUGH THE END OF THE PERIOD. LIGHT AND VARIABLE WINDS ON
SUN...WITH SEA BREEZE DOMINATING NEAR SHORE FLOW...WILL BECOME
SOUTHEAST TO SOUTH MON AND TUE. GRADIENT WILL REMAIN ON THE WEAK
SIDE WITH SPEEDS GENERALLY 10 KT OR LESS. DAILY SEA BREEZE WILL
RESULT IN A SLIGHT BUMP IN SPEEDS NEAR SHORE IN THE AFTERNOON.
SEAS AROUND 2 FT WILL BE MAINTAINED THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...REK/TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...MRR
MARINE...REK/III/MBB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
712 PM EDT THU APR 30 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE SLOWLY UP THE CAROLINA COAST THROUGH
TONIGHT BEFORE FINALLY MOVING AWAY FROM THE AREA DURING FRIDAY.
THE RISK FOR SHOWERS AND SOME THUNDERSTORMS WILL REMAIN THROUGH
FRIDAY. HIGH PRESSURE WILL BUILD ACROSS THE AREA FOR THE WEEKEND
AND INTO THE FIRST PART OF NEXT WEEK. THE DRY WEATHER AND
RETURNING SUNSHINE WILL ALLOW TEMPERATURES TO RETURN TO SEASONABLE
LEVELS BY THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 715 PM THURSDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
LOW PRESSURE CENTERED SOUTH OF CAPE HATTERAS SHOULD SLOW TONIGHT
AS A POWERFUL UPPER LEVEL DISTURBANCE DIVES SOUTHWARD FROM INDIANA
INTO NORTH CAROLINA. ALTHOUGH LOW- LEVEL BAROCLINICITY IS VERY
WEAK...A FAVORABLY ORIENTED JET STREAK OFFSHORE PLUS INCOMING
VORTICITY WITH THE DISTURBANCE SHOULD LEAD TO SLOWLY FALLING
PRESSURES OFFSHORE.
AWAY FROM EXTREME EASTERN NC (INCLUDING WILMINGTON) THERE HAS BEEN
PLENTY OF SUNSHINE TODAY. TEMPERATURES RISING INTO THE 70S PLUS
RATHER COOL TEMPERATURES ALOFT HAVE HELPED GENERATE SURFACE-BASED
CAPE AS LARGE AS 500 J/KG ALONG AND WEST OF I-95. SO FAR THIS HAS
RESULTED IN AN EXPANSIVE CUMULUS FIELD ACROSS WESTERN NC PLUS A
SMATTERING OF SHOWERS. AS 800-600 MB TEMPERATURES FALL FURTHER THIS
EVENING AND THE FIRST OF SEVERAL UPPER DISTURBANCES ARRIVES FROM THE
WEST...THE POTENTIAL FOR SHOWERS WILL EXPAND ACROSS SOUTHEASTERN
NORTH CAROLINA AND NORTHERN PORTIONS OF THE PEE DEE REGION. I HAVE
DECIDED NOT TO INCLUDE THUNDER IN THE FORECAST AS IT APPEARS AN
INVERSION BETWEEN 500-600 MB SHOULD BE SUFFICIENTLY STRONG TO CAP
OFF UPDRAFTS BEFORE THEY BECOME COLD ENOUGH ALOFT. 12Z MODELS HAVE
BACKED OFF A LITTLE COMPARED TO THEIR 00Z/06Z COUNTERPARTS WITH THE
SOUTHERN EXTENT OF PRECIPITATION...AND THIS TREND IS ECHOED BY THE
LAST FEW HRRR RUNS AS WELL.
BY LATE TONIGHT THE MAIN UPPER LOW WILL WOBBLE INTO CENTRAL NORTH
CAROLINA. NEAR AND NORTH OF THE LOW IS WHERE UNSTABLE CONDITIONS
SHOULD CONTINUE OVERNIGHT DUE TO COLD AIR ALOFT. OUR FORECAST AREA
SHOULD LARGELY REMAIN SOUTH OF THE INSTABILITY...SO ASIDE FROM
MAINTAINING 30-40 PERCENT POPS ACROSS LUMBERTON-ELIZABETHTOWN-BURGAW
I HAVE CUT POPS TO 10-20 POPS OVERNIGHT...WITH LOWS GENERALLY IN THE
LOWER 50S EXCEPT MID 50S AT THE BEACHES.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY... A STRONG UPPER LOW WILL CUT BY TO OUR NORTH
ON FRIDAY. EVEN SO WE SHOULD SEE VERY STRONG PVA AND HEIGHT FALLS
LOCALLY AND SOME LIGHT SHOWERS SEEM LIKELY OVER NORTHERN ZONES.
STILL TOUGH TO RULE OUT THUNDER WITH UPWARDS OF 600J/KG OF CAPE
DEVELOPING. SOME OF THIS INSTABILITY MAY GO SUFFICIENTLY INTO THE
HAIL GROWTH LAYER FOR SOME PEA SIZED HAIL TO REACH THE GROUND
UNDERNEATH THE DEEPER CONVECTIVE CELLS. CLOUD COVER WILL MEANWHILE
BRING ONE LAST DAY OF CONSIDERABLY COOL TEMPS WITH HIGHS STUCK IN
THE 60S. DRY AIR MOVES IN FRIDAY NIGHT INTO SATURDAY. THERE IS
HOWEVER ONE TRAILING VORT AND WRAPAROUND MOISTURE ON SATURDAY AND
SOME GUIDANCE HINTING AT PRECIP OVER CAPE FEAR/COASTAL NC ZONES.
FEEL IF ANYTHING AT ALL WILL BE JUST NON-MEASURABLE AND HAVE KEPT
THE FORECAST DRY AT THIS TIME. THE DECREASED CLOUD COVER WILL ALLOW
FOR A NICE BUMP IN TEMPERATURES COME SATURDAY BUT THE NORTHERLY FLOW
COMPONENT THROUGH A DEEP LAYER WILL STILL KEEP US A TAD BELOW CLIMO.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...BERMUDA HIGH AND MID LEVEL RIDGE BUILDING OVER
THE SOUTHEAST WILL KEEP THE REGION DRY DURING THE PERIOD WITH
TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO. AS FAR AS THE TROPICAL
WAVE/LOW COMBO EMERGING FROM THE BAHAMAS NEXT WEEK GOES THE LATEST
MEDIUM RANGE GUIDANCE HAS FALLEN OUT OF FAVOR WITH THIS SCENARIOS.
NEARLY ALL OF THE GUIDANCE (INCLUDING THE ENSEMBLES) NOW SHOW A
SHEARED OUT SURFACE WAVE MOVING EAST-NORTHEAST...REMAINING WELL
SOUTHEAST OF THE COAST. LATER IN THE PERIOD CANNOT RULE OUT AN
ISOLATED SEA BREEZE SHOWER AS LOW LEVEL MOISTURE INCREASES BUT
COVERAGE WILL BE QUITE LIMITED AND DOES NOT WARRANT INCLUSION OF POP
GREATER THAN 15 AT THIS TIME.
&&
.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...VFR/MVFR PREVAILS WITH ISOLATED TO SCATTERED SHOWERS
POSSIBLE LATER TODAY. EXPECT CONDITIONS TO DETERIORATE TO MVFR/IFR
LATE OVERNIGHT INTO FRIDAY MORNING.
A MIXTURE OF VFR/MVFR PREVAILS ACROSS THE AREA THIS AFTERNOON WITH
VARYING CLOUD HEIGHTS. LATER TODAY ANTICIPATE THE RE-DEVELOPMENT OF
SHOWERS ACROSS THE AREA...WHICH WITH LINGERING LOW CIGS COULD CREATE
PERIODS OF LOWERED RESTRICTIONS. AS FOR WINDS...EXPECT NORTH-
NORTHWEST WINDS AOB 12 KTS TO PERSIST. INTO THE OVERNIGHT
HOURS...WINDS WILL BECOME LIGHT AND CONDITIONS WILL GRADUALLY
DETERIORATE AS LOW CIGS AND AREAS OF FOG INFILTRATE INTO THE AREA.
LIGHT SHOWERS ARE POSSIBLE INTO FRIDAY.
EXTENDED OUTLOOK...EXPECT VFR THROUGH THE FORECAST PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 715 PM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
LOW PRESSURE HAS MOVED SOUTH OF HATTERAS THIS AFTERNOON BUT
SHOULD SLOW TONIGHT AS A STRONG UPPER LEVEL DISTURBANCE APPROACHES
FROM THE WEST. THIS DISTURBANCE WILL CREATE A ZONE OF WEAKENED
PRESSURE GRADIENT ACROSS EASTERN NORTH CAROLINA TONIGHT...WHILE TO
THE SOUTH ACROSS SOUTH CAROLINA THE GRADIENT SHOULD GRADUALLY
TIGHTEN WITH INCREASING WESTERLY WINDS EXPECTED. BY DAYBREAK WINDS
JUST EAST OF WINYAH BAY/GEORGETOWN COULD REACH 15-20 KT. THE
VARIOUS COMPUTER MODELS HAVE DIFFERING POSITIONS OF WHERE THE
BOUNDARY BETWEEN THESE STRONGER WEST WINDS AND LIGHTER NORTH WINDS
CLOSER TO THE LOW WILL SET UP...AND I HAVE FOLLOWED THE 12Z GFS AS
A GUIDE TONIGHT.
SEAS CURRENTLY RANGE FROM 2-3 FEET INSIDE 20 MILES OF SHORE...TO 4
FEET OUT AT THE FRYING PAN SHOALS BUOY. SEAS MAY SUBSIDE A BIT THIS
EVENING BUT SHOULD INCREASE AGAIN OVERNIGHT...ESPECIALLY SOUTH OF
CAPE FEAR...DUE TO THE INCREASING WIND SPEEDS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...LOW PRESSURE OFF CAPE HATTERAS WILL BE SLOW
TO MOVE ON FRIDAY, ENERGIZED IN PART BY A STRONG LOW IN THE MID
LEVELS. THIS FEATURE WILL STRENGTHEN VERTICAL MIXING MORE THAN THE
ACTUAL SURFACE PRESSURE GRADIENT, POSSIBLY ENOUGH FOR SOME
ADVISORY-WORTHY 25KT WINDS OVER MAINLY JUST OUR NORTHERNMOST ZONE-
MAINLY FRIDAY NIGHT. ALL MODELS ARE NOT CONVINCED OF THIS AND
THERE IS STILL A BIT OF TIME TO IRON OUT THE UNCERTAINTY SO ONE
WILL NOT BE RAISED AT THIS TIME. THE LOW WILL BE GRADUALLY PULLING
AWAY TO THE NORTHEAST ON SATURDAY. WINDS LOCALLY WILL REMAIN N TO
NW AND SLOWLY SUBSIDE. THERE MAY EVEN BE A BIT OF BACKSWELL FROM
THE OFFSHORE STORM AS IT GROWS A BIT LARGER IN SIZE.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...SURFACE HIGH MOVING OFF THE COAST SUN
MORNING WILL SETUP NEAR BERMUDA SUN EVENING AND REMAIN IN PLACE
THROUGH THE END OF THE PERIOD. LIGHT AND VARIABLE WINDS ON
SUN...WITH SEA BREEZE DOMINATING NEAR SHORE FLOW...WILL BECOME
SOUTHEAST TO SOUTH MON AND TUE. GRADIENT WILL REMAIN ON THE WEAK
SIDE WITH SPEEDS GENERALLY 10 KT OR LESS. DAILY SEA BREEZE WILL
RESULT IN A SLIGHT BUMP IN SPEEDS NEAR SHORE IN THE AFTERNOON.
SEAS AROUND 2 FT WILL BE MAINTAINED THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...REK/TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...SGL
MARINE...REK/III/MBB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
100 PM EDT WED APR 29 2015
.SYNOPSIS...
SURFACE AND MID LEVEL LOW PRESSURE WILL BRING PERIODS OF RAIN
THROUGH EARLY FRIDAY. HIGH PRESSURE WILL BUILD IN LATE FRIDAY
SETTING THE STAGE FOR A WONDERFUL WEEKEND OF WEATHER. THE NICE
CONDITIONS WILL PERSIST INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM WEDNESDAY...RADAR SHOWS QUITE AN IMPRESSIVE BATCH OF
RAIN WITH EMBEDDED HEAVY SHOWERS EXTENDING ACROSS MOST OF CENTRAL
SOUTH CAROLINA...MOVING NE JUST OVER 30 MPH. LINEAR EXTRAPOLATION
TAKES THE BULK OF THIS ACTIVITY JUST NORTH OF FLORENCE...SOAKING
DARLINGTON AND BENNETTSVILLE OVER THE NEXT 2-3 HOURS...WITH
INTERMITTENT SHOWER ACTIVITY EXPECTED TO TRAIL SOUTH OF THE MAIN
CORE ACROSS THE BULK OF NE SOUTH CAROLINA. SHOWERS SHOULD FINALLY
MAKE IT DOWN TO COASTAL NC BY LATE AFTERNOON...PERHAPS BEGINNING
AROUND 4-5 PM.
HRRR AND RUC MODELING OF THIS EVENT HAS BEEN VERY POOR TO SAY THE
LEAST. THIS EARLY AFTERNOON UPDATE IS BASED SOLELY ON EXTRAPOLATION
OF SATELLITE AND RADAR TRENDS. VISIBLE SATELLITE STILL SHOWS
CONSIDERABLE BREAKS IN THE OVERCAST AHEAD OF THE INCOMING SHOWERS. I
HAVE RAISED FORECAST HIGHS BY ANOTHER DEGREE IN SPOTS WITH 68-69
DEGREES NOW FORECAST ACROSS LUMBERTON AND ELIZABETHTOWN. FALLING
TEMPERATURES DURING THE MID-AFTERNOON ARE BEING INDICATED WHERE THE
MOST CONCENTRATED RAIN SHOULD OCCUR. DISCUSSION FROM 1030 AM
FOLLOWS...
UNFORTUNATELY MAJOR CHANGES ARE NEEDED TO THE FORECAST OVER THE NEXT
6-9 HOURS. ALL MODELS...EVEN THE LATEST RUNS OF THE RUC & HRRR...ARE
HAVING SERIOUS ISSUES SEEING THE WIDE GAP BETWEEN THIS MORNING`S
LEAD BATCH OF RAIN AND THE SECOND BATCH OF SHOWERS ASSOCIATED WITH
THE MID AND UPPER LEVEL SYSTEM MOVING EAST ACROSS GEORGIA.
FIRST OF ALL...THE LEAD BATCH OF RAIN MOVING ACROSS NE SOUTH
CAROLINA THIS MORNING IS ASSOCIATED WITH MID-LEVEL ISENTROPIC LIFT
ALONG THE 305K-315K THETA SURFACES. IF YOU LOOK THIS UP ON A
FORECAST SKEW-T YOU`LL SEE THIS IS ALL 9000+ FEET ABOVE GROUND WITH
DRIER AIR BELOW THE CLOUD DECK. RAINFALL RATES HAVE BEEN RECORDED AS
HIGH AS .08 IN/HR AT GEORGETOWN SC...WITH ONLY TRACE AMOUNTS UP AT
FLORENCE. BEHIND THIS BATCH OF RAIN...VISIBLE SATELLITE SHOWS BREAKS
IN THE OVERCAST ACROSS THE SANDHILLS AND PIEDMONT REGION OF SOUTH
CAROLINA. AS THIS ADVECTS EASTWARD ACROSS THE AREA TEMPERATURES
SHOULD RESPOND QUICKLY THIS TO PERIOD OF SUNSHINE. I HAVE RAISED
FORECAST HIGHS BY 5 DEGREES FROM DARLINGTON AND BENNETTSVILLE ACROSS
LUMBERTON AND ELIZABETHTOWN...WITH LESSER INCREASES ELSEWHERE.
THE MID AND UPPER LEVEL SYSTEM ACROSS NORTH GEORGIA WILL DAMPEN OUT
AS IT MOVES EASTWARD INTO THE CAROLINAS LATER TODAY. HOWEVER THERE
SHOULD STILL BE A FAIRLY ORGANIZED AREA OF SHOWERS ASSOCIATED WITH
THIS FEATURE...REACHING INTERSTATE 95 AS EARLY AS NOON-1 PM...AND
WORKING ITS WAY DOWN TO THE NC/SC BEACHES BETWEEN 2-4 PM. FORECAST
SOUNDINGS INDICATE VERY SLIGHT ELEVATED INSTABILITY BASED AROUND
8000-9000 FEET UP...WHICH SHOULD ADD A MINOR CONVECTIVE ELEMENT TO
THE BATCH OF LIGHT TO MODERATE RAINFALL. THIS SHOULD BRING A
WIDESPREAD 0.1 TO 0.2 INCHES OF RAIN...WITH SPOTTIER HEAVIER AMOUNTS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...FORECAST REMAINS DIFFICULT TO ASCERTAIN
JUST IF AND WHEN HIGHER POPS WILL BE REQUIRED THROUGH MOST OF THE
PERIOD.
INITIALLY LOW PRESSURE WILL BE LOCATED OFF THE CAPE FEAR COAST WITH
SHEARED VORTICITY MOVING ACROSS AT THE MID LEVELS. A BAND OF HEAVIER
RAINFALL IS DEPICTED BY THE GFS NEAR THE COAST AND IS REFLECTED IN
THE MOS NUMBERS. I HAVE INCREASED POPS THROUGH 1800 UTC THURSDAY
MOSTLY ALONG THE COAST. THE REMAINDER OF THE POPS WILL BE DICTATED
BY THE MID LEVEL LOW SWINGING ACROSS THE AREA FRIDAY.
I HAVE LOWER VALUES FOR THURSDAY NIGHT ALTHOUGH STILL NOT REMOVING
ENTIRELY INCREASING SOMEWHAT FOR THE FIRST PART OF FRIDAY. OVERALL
THURSDAY LOOKS LIKE THE LAST TIMEFRAME FOR DECENT RAINFALL AS THE
REMAINDER OF THE ACTIVITY WILL BE LIGHT. THERE MAY BE SOME CLEARING
FRIDAY ESPECIALLY SOUTH AS THE SYSTEM FINALLY PULLS AWAY.
TEMPERATURE FORECAST REQUIRED ONLY MINIMAL ADJUSTMENTS TO GRAVITATE
MORE TOWARD THE LATEST GFS/MAV NUMBERS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...FORECAST REMAINS ALL BUT UNCHANGED WITH
THE MORNING UPDATE AS A MOSTLY ZONAL AND RELATIVELY WEAK MID
LEVEL PATTERN DEVELOPS. HIGH PRESSURE WILL MOVE FROM THE
MISSISSIPPI VALLEY TO WELL OFFSHORE...ASSUMING THE BERMUDA
POSITION THAT WE WILL BE SEEING MUCH MORE OF IN THE COMING MONTHS.
DONT SEE ANY POPS IN THE FORECAST. ONE INTERESTING NOTE IS THE
DEVELOPMENT OF A TROPICAL OR MORE LIKE A SUBTROPICAL FEATURE
CONSIDERING WATER TEMPERATURES NEAR THE FLORIDA PENINSULA NEXT
WEEK. BOTH THE GFS AND ECMWF HAVE THIS FEATURE BUT VERY PREMATURE
TO DIAGNOSE AT THIS POINT. STILL SOMETHING TO WATCH. TEMPERATURE
TRENDS REMAIN IN PLACE SLIGHTLY BELOW AVERAGE INITIALLY WARMING TO
ABOVE BY THE END OF THE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...CONDITIONS WILL GRADUALLY DETERIORATE TO MVFR/IFR LATER
TODAY AND CONTINUE THROUGH MUCH OF THE VALID TAF PERIOD AS LOW
CLOUDS...AREAS OF FOG...AND PERIODS OF RAIN MOVE THROUGH THE
FORECAST AREA.
VFR PREVAILS THIS AFTERNOON WITH LIGHT EAST-NORTHEAST WINDS AND
ISOLATED TO SCATTERED SHOWERS AS SEEN FROM LATEST SATELLITE IMAGERY.
FOR THIS AFTERNOON AND INTO THE EVENING HOURS...EXPECT RAINFALL TO
BECOME MORE WIDESPREAD. CONDITIONS WILL GRADUALLY DETERIORATE TO
MVFR/IFR AND CONTINUE INTO SATURDAY AS LOW CIGS AND AREAS OF FOG
ADVECT ACROSS THE AREA. EXPECT WINDS TO BACK TO THE NORTHEAST AT ALL
SITES THIS AFTERNOON AS LOW PRESSURE MOVES CLOSER TO THE
AREA...INCREASING TO AOB 10 KTS...AND POTENTIALLY SLIGHTLY HIGHER
ALONG THE COAST. INTO THE OVERNIGHT HOURS...RAIN WILL TAPER OFF BUT
ANTICIPATE A RETURN OF -RA/SHRA THURSDAY MORNING.
EXTENDED OUTLOOK...A CONTINUING CHANCE FOR SHOWERS WITH POTENTIAL
MVFR/IFR CONDITIONS THROUGH FRIDAY. OTHERWISE EXPECT VFR.
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM WEDNESDAY...WIND OBSERVATIONS FROM BUOYS...PIERS...AND
COASTAL AIRPORTS INDICATE A GENERALLY EAST TO SOUTHEAST WIND WITH
SPEEDS BELOW 10 KNOTS. LOW PRESSURE A LITTLE OVER 100 MILES OFF THE
FLORIDA EAST COAST IS BECOMING THE DOMINANT WEATHER FEATURE AND
SHOULD HELP INCREASE WIND SPEEDS TO 10-15 KT BY THIS EVENING. THE
MORNING BATCH OF RAIN HAS LARGELY DISSIPATED WITH JUST SOME
SPRINKLES REMAINING ACROSS THE COASTAL WATERS. RADAR SHOWS ANOTHER
BATCH OF SHOWERS MOVING OUT OF CENTRAL SOUTH CAROLINA THAT SHOULD
REACH THE BEACHES BETWEEN 3-6 PM. NO CHANGES ARE NEEDED TO SEA
HEIGHT FORECASTS. DISCUSSION FROM 1030 AM FOLLOWS...
THE SUITE OF COMPUTER MODELS AVAILABLE TO US IS STRUGGLING GREATLY
WITH CURRENT WIND DIRECTIONS. OBSERVATIONS ACROSS THE AREA SHOW
VARIABLE WIND DIRECTIONS WITH SPEEDS 6 KNOTS OR LESS AT THE BEACHES.
FARTHER OFFSHORE WHERE THE SYNOPTIC PRESSURE GRADIENT WOULD SUGGEST
A NORTHEAST WIND WE ARE SEEING VARIABILITY HERE AS WELL DUE TO
SHOWERS 20+ MILES OFFSHORE PRODUCING SOME OUTFLOW WIND EFFECTS. AS
THE WEAK LOW OFF THE FLORIDA EAST COAST BECOMES A LITTLE BETTER
ORGANIZED AND MOVES CLOSER THIS AFTERNOON WE ANTICIPATE EASTERLY
WINDS TO BECOME BETTER ESTABLISHED. THERE MAY STILL BE REMAINING
VARIABILITY HOWEVER DUE TO ANOTHER WAVE OF SHOWERS EXPECTED TO
ARRIVE DURING THE MID AFTERNOON HOURS FROM THE WEST.
I HAVE INCREASED FORECAST SEA HEIGHTS BY 1 FOOT THROUGH THE
REMAINDER OF TODAY. CURRENT WAVE OBSERVATIONS FROM LOCAL BUOYS
INDICATE 2 FEET NEARSHORE AND 3 FEET OUT AT THE FRYING PAN SHOALS
BUOY...ABOUT 1 FOOT HIGHER THEN PREVIOUSLY FORECAST.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...LOW PRESSURE WILL BE ABOUT 150 MILES OFF THE
CAPE FEAR COAST THURSDAY MORNING. THIS SYSTEM WILL MOVE NORTHEAST
DURING THE DAY. WINDS...INITIALLY FROM THE NORTH WILL TURN TO THE
NORTHWEST BY MIDDAY. WIND SPEEDS WILL BE 15-20 KNOTS. WIND SPEEDS
WILL DIMINISH TO A RANGE OF 10-15 KNOTS THURSDAY NIGHT AND CONTINUE
IN THIS RANGE AND DIRECTION FOR MOST OF THE DAY FRIDAY. A SECONDARY
SURGE WILL OCCUR LATE FRIDAY KICKING WINDS BACK UP TO 15-20 KNOTS
DIMINISHING ONCE AGAIN BY SATURDAY MORNING. WITH THIS PATTERN THE
HIGHER SEAS WILL RELEGATED TO THE OUTER WATERS. HEIGHTS WILL MOSTLY
BE 2-4 FEET BUT GUIDANCE IS SHOWING A FEW SIX FOOTERS ACROSS THE NC
WATERS LATE FRIDAY.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...NICE CONDITIONS FOR THE MARINE COMMUNITY
FOR THE EXTENDED PERIOD. A LITTLE BREEZY TO START WITH WINDS FROM
THE NORTHWEST AT 10-15 KNOTS. WINDS WILL QUICKLY SUBSIDE AS HIGH
PRESSURE MOVES EAST ACROSS THE CAROLINAS. SHOULD SEE TEN KNOTS OR
LESS BY SUNDAY MORNING. A RETURN FLOW DEVELOPS LATER SUNDAY WITH
SOUTH TO SOUTHWEST WINDS ONCE AGAIN...TEN KNOTS OR LESS. SEAS WILL
BE 1-3 FEET THROUGHOUT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...SGL
AREA FORECAST DISCUSSION...CORRECTED TYPO
NWS WILMINGTON NC
1035 AM EDT WED APR 29 2015
.SYNOPSIS...
SURFACE AND MID LEVEL LOW PRESSURE WILL BRING PERIODS OF RAIN
THROUGH EARLY FRIDAY. HIGH PRESSURE WILL BUILD IN LATE FRIDAY
SETTING THE STAGE FOR A WONDERFUL WEEKEND OF WEATHER. THE NICE
CONDITIONS WILL PERSIST INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...UNFORTUNATELY MAJOR CHANGES ARE NEEDED TO
THE FORECAST OVER THE NEXT 6-9 HOURS. ALL MODELS...EVEN THE LATEST
RUNS OF THE RUC & HRRR...ARE HAVING SERIOUS ISSUES SEEING THE WIDE
GAP BETWEEN THIS MORNING`S LEAD BATCH OF RAIN AND THE SECOND BATCH
OF SHOWERS ASSOCIATED WITH THE MID AND UPPER LEVEL SYSTEM MOVING
EAST ACROSS GEORGIA.
FIRST OF ALL...THE LEAD BATCH OF RAIN MOVING ACROSS NE SOUTH
CAROLINA THIS MORNING IS ASSOCIATED WITH MID-LEVEL ISENTROPIC LIFT
ALONG THE 305K-315K THETA SURFACES. IF YOU LOOK THIS UP ON A
FORECAST SKEW-T YOU`LL SEE THIS IS ALL 9000+ FEET ABOVE GROUND WITH
DRIER AIR BELOW THE CLOUD DECK. RAINFALL RATES HAVE BEEN RECORDED AS
HIGH AS .08 IN/HR AT GEORGETOWN SC...WITH ONLY TRACE AMOUNTS UP AT
FLORENCE. BEHIND THIS BATCH OF RAIN...VISIBLE SATELLITE SHOWS BREAKS
IN THE OVERCAST ACROSS THE SANDHILLS AND PIEDMONT REGION OF SOUTH
CAROLINA. AS THIS ADVECTS EASTWARD ACROSS THE AREA TEMPERATURES
SHOULD RESPOND QUICKLY THIS TO PERIOD OF SUNSHINE. I HAVE RAISED
FORECAST HIGHS BY 5 DEGREES FROM DARLINGTON AND BENNETTSVILLE ACROSS
LUMBERTON AND ELIZABETHTOWN...WITH LESSER INCREASES ELSEWHERE.
THE MID AND UPPER LEVEL SYSTEM ACROSS NORTH GEORGIA WILL DAMPEN OUT
AS IT MOVES EASTWARD INTO THE CAROLINAS LATER TODAY. HOWEVER THERE
SHOULD STILL BE A FAIRLY ORGANIZED AREA OF SHOWERS ASSOCIATED WITH
THIS FEATURE...REACHING INTERSTATE 95 AS EARLY AS NOON-1 PM...AND
WORKING ITS WAY DOWN TO THE NC/SC BEACHES BETWEEN 2-4 PM. FORECAST
SOUNDINGS INDICATE VERY SLIGHT ELEVATED INSTABILITY BASED AROUND
8000-9000 FEET UP...WHICH SHOULD ADD A MINOR CONVECTIVE ELEMENT TO
THE BATCH OF LIGHT TO MODERATE RAINFALL. THIS SHOULD BRING A
WIDESPREAD 0.1 TO 0.2 INCHES OF RAIN...WITH SPOTTIER HEAVIER AMOUNTS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...FORECAST REMAINS DIFFICULT TO ASCERTAIN
JUST IF AND WHEN HIGHER POPS WILL BE REQUIRED THROUGH MOST OF THE
PERIOD.
INITIALLY LOW PRESSURE WILL BE LOCATED OFF THE CAPE FEAR COAST WITH
SHEARED VORTICITY MOVING ACROSS AT THE MID LEVELS. A BAND OF HEAVIER
RAINFALL IS DEPICTED BY THE GFS NEAR THE COAST AND IS REFLECTED IN
THE MOS NUMBERS. I HAVE INCREASED POPS THROUGH 1800 UTC THURSDAY
MOSTLY ALONG THE COAST. THE REMAINDER OF THE POPS WILL BE DICTATED
BY THE MID LEVEL LOW SWINGING ACROSS THE AREA FRIDAY.
I HAVE LOWER VALUES FOR THURSDAY NIGHT ALTHOUGH STILL NOT REMOVING
ENTIRELY INCREASING SOMEWHAT FOR THE FIRST PART OF FRIDAY. OVERALL
THURSDAY LOOKS LIKE THE LAST TIMEFRAME FOR DECENT RAINFALL AS THE
REMAINDER OF THE ACTIVITY WILL BE LIGHT. THERE MAY BE SOME CLEARING
FRIDAY ESPECIALLY SOUTH AS THE SYSTEM FINALLY PULLS AWAY.
TEMPERATURE FORECAST REQUIRED ONLY MINIMAL ADJUSTMENTS TO GRAVITATE
MORE TOWARD THE LATEST GFS/MAV NUMBERS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...FORECAST REMAINS ALL BUT UNCHANGED WITH
THE MORNING UPDATE AS A MOSTLY ZONAL AND RELATIVELY WEAK MID
LEVEL PATTERN DEVELOPS. HIGH PRESSURE WILL MOVE FROM THE
MISSISSIPPI VALLEY TO WELL OFFSHORE...ASSUMING THE BERMUDA
POSITION THAT WE WILL BE SEEING MUCH MORE OF IN THE COMING MONTHS.
DONT SEE ANY POPS IN THE FORECAST. ONE INTERESTING NOTE IS THE
DEVELOPMENT OF A TROPICAL OR MORE LIKE A SUBTROPICAL FEATURE
CONSIDERING WATER TEMPERATURES NEAR THE FLORIDA PENINSULA NEXT
WEEK. BOTH THE GFS AND ECMWF HAVE THIS FEATURE BUT VERY PREMATURE
TO DIAGNOSE AT THIS POINT. STILL SOMETHING TO WATCH. TEMPERATURE
TRENDS REMAIN IN PLACE SLIGHTLY BELOW AVERAGE INITIALLY WARMING TO
ABOVE BY THE END OF THE PERIOD.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...VFR THROUGH THE MORNING HOURS WILL GRADUALLY
DETERIORATE TO MVFR/POTENTIAL IFR LATER TODAY AS LOW
CLOUDS...AREAS OF FOG...AND PERIODS OF RAIN MOVE THROUGH THE
FORECAST AREA.
VFR PREVAILS THIS MORNING WITH LIGHT AND VARIABLE WINDS...AND AS
SEEN FROM LATEST RADAR IMAGERY...LIGHT RAIN SHOWERS AROUND
KFLO/KMYR/KCRE. WILL CONTINUE TO SEE -RA/SHRA INFILTRATE EAST-
NORTHEAST ACROSS THE AREA AND INCREASE IN INTENSITY TODAY AND THIS
EVENING AS LOW PRESSURE CREATES UNSETTLED WEATHER OVER THE NEXT
COUPLE OF DAYS. LIGHT EASTERLY WINDS THIS MORNING WILL BACK TO THE
NORTHEAST TODAY...INCREASING TO AOB 10 KTS...WITH SLIGHTLY HIGHER
POSSIBLY ALONG THE COAST. INTO THE OVERNIGHT HOURS...RAIN WILL
TAPER OFF BUT LOW CLOUDS AND AREAS OF FOG WILL LINGER...CREATING
MVFR/POSSIBLY IFR.
EXTENDED OUTLOOK...A CONTINUING CHANCE FOR SHOWERS WITH POTENTIAL
MVFR/IFR CONDITIONS THROUGH FRIDAY. OTHERWISE EXPECT VFR.
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 WEDNESDAY...THE SUITE OF COMPUTER MODELS AVAILABLE TO US
IS STRUGGLING GREATLY WITH CURRENT WIND DIRECTIONS. OBSERVATIONS
ACROSS THE AREA SHOW VARIABLE WIND DIRECTIONS WITH SPEEDS 6 KNOTS OR
LESS AT THE BEACHES. FARTHER OFFSHORE WHERE THE SYNOPTIC PRESSURE
GRADIENT WOULD SUGGEST A NORTHEAST WIND WE ARE SEEING VARIABILITY
HERE AS WELL DUE TO SHOWERS 20+ MILES OFFSHORE PRODUCING SOME
OUTFLOW WIND EFFECTS. AS THE WEAK LOW OFF THE FLORIDA EAST COAST
BECOMES A LITTLE BETTER ORGANIZED AND MOVES CLOSER THIS AFTERNOON WE
ANTICIPATE EASTERLY WINDS TO BECOME BETTER ESTABLISHED. THERE MAY
STILL BE REMAINING VARIABILITY HOWEVER DUE TO ANOTHER WAVE OF
SHOWERS EXPECTED TO ARRIVE DURING THE MID AFTERNOON HOURS FROM THE
WEST.
I HAVE INCREASED FORECAST SEA HEIGHTS BY 1 FOOT THROUGH THE
REMAINDER OF TODAY. CURRENT WAVE OBSERVATIONS FROM LOCAL BUOYS
INDICATE 2 FEET NEARSHORE AND 3 FEET OUT AT THE FRYING PAN SHOALS
BUOY...ABOUT 1 FOOT HIGHER THEN PREVIOUSLY FORECAST.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...LOW PRESSURE WILL BE ABOUT 150 MILES OFF THE
CAPE FEAR COAST THURSDAY MORNING. THIS SYSTEM WILL MOVE NORTHEAST
DURING THE DAY. WINDS...INITIALLY FROM THE NORTH WILL TURN TO THE
NORTHWEST BY MIDDAY. WIND SPEEDS WILL BE 15-20 KNOTS. WIND SPEEDS
WILL DIMINISH TO A RANGE OF 10-15 KNOTS THURSDAY NIGHT AND CONTINUE
IN THIS RANGE AND DIRECTION FOR MOST OF THE DAY FRIDAY. A SECONDARY
SURGE WILL OCCUR LATE FRIDAY KICKING WINDS BACK UP TO 15-20 KNOTS
DIMINISHING ONCE AGAIN BY SATURDAY MORNING. WITH THIS PATTERN THE
HIGHER SEAS WILL RELEGATED TO THE OUTER WATERS. HEIGHTS WILL MOSTLY
BE 2-4 FEET BUT GUIDANCE IS SHOWING A FEW SIX FOOTERS ACROSS THE NC
WATERS LATE FRIDAY.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...NICE CONDITIONS FOR THE MARINE COMMUNITY
FOR THE EXTENDED PERIOD. A LITTLE BREEZY TO START WITH WINDS FROM
THE NORTHWEST AT 10-15 KNOTS. WINDS WILL QUICKLY SUBSIDE AS HIGH
PRESSURE MOVES EAST ACROSS THE CAROLINAS. SHOULD SEE TEN KNOTS OR
LESS BY SUNDAY MORNING. A RETURN FLOW DEVELOPS LATER SUNDAY WITH
SOUTH TO SOUTHWEST WINDS ONCE AGAIN...TEN KNOTS OR LESS. SEAS WILL
BE 1-3 FEET THROUGHOUT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1033 AM EDT WED APR 29 2015
.SYNOPSIS...
SURFACE AND MID LEVEL LOW PRESSURE WILL BRING PERIODS OF RAIN
THROUGH EARLY FRIDAY. HIGH PRESSURE WILL BUILD IN LATE FRIDAY
SETTING THE STAGE FOR A WONDERFUL WEEKEND OF WEATHER. THE NICE
CONDITIONS WILL PERSIST INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...UNFORTUNATELY MAJOR CHANGES ARE NEEDED TO
THE FORECAST OVER THE NEXT 6-9 HOURS. ALL MODELS...EVEN THE LATEST
RUNS OF THE RUC & HRRR...ARE HAVE SERIOUS ISSUES SEEING THE WIDE GAP
BETWEEN THIS MORNING`S LEAD BATCH OF RAIN AND THE SECOND BATCH OF
SHOWERS ASSOCIATED WITH THE MID AND UPPER LEVEL SYSTEM MOVING EAST
ACROSS GEORGIA.
FIRST OF ALL...THE LEAD BATCH OF RAIN MOVING ACROSS NE SOUTH
CAROLINA THIS MORNING IS ASSOCIATED WITH MID-LEVEL ISENTROPIC LIFT
ALONG THE 305K-315K THETA SURFACES. IF YOU LOOK THIS UP ON A
FORECAST SKEW-T YOU`LL SEE THIS IS ALL 9000+ FEET ABOVE GROUND WITH
DRIER AIR BELOW THE CLOUD DECK. RAINFALL RATES HAVE BEEN RECORDED AS
HIGH AS .08 IN/HR AT GEORGETOWN SC...WITH ONLY TRACE AMOUNTS UP AT
FLORENCE. BEHIND THIS BATCH OF RAIN...VISIBLE SATELLITE SHOWS BREAKS
IN THE OVERCAST ACROSS THE SANDHILLS AND PIEDMONT REGION OF SOUTH
CAROLINA. AS THIS ADVECTS EASTWARD ACROSS THE AREA TEMPERATURES
SHOULD RESPOND QUICKLY THIS TO PERIOD OF SUNSHINE. I HAVE RAISED
FORECAST HIGHS BY UP TO 5 DEGREES FROM DARLINGTON AND BENNETTSVILLE
ACROSS LUMBERTON AND ELIZABETHTOWN...WITH LESSER INCREASES
ELSEWHERE.
THE MID AND UPPER LEVEL SYSTEM ACROSS NORTH GEORGIA WILL DAMPEN OUT
AS IT MOVES EASTWARD INTO THE CAROLINAS LATER TODAY. HOWEVER THERE
SHOULD STILL BE A FAIRLY ORGANIZED AREA OF SHOWERS ASSOCIATED WITH
THIS FEATURE...REACHING INTERSTATE 95 AS EARLY AS NOON-1 PM...AND
WORKING ITS WAY DOWN TO THE NC/SC BEACHES BETWEEN 2-4 PM. FORECAST
SOUNDINGS INDICATE VERY SLIGHT ELEVATED INSTABILITY BASED AROUND
8000-9000 FEET UP...WHICH SHOULD ADD A MINOR CONVECTIVE ELEMENT TO
THE BATCH OF LIGHT TO MODERATE RAINFALL. THIS SHOULD BRING A
WIDESPREAD 0.1 TO 0.2 INCHES OF RAIN...WITH SPOTTIER HEAVIER AMOUNTS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...FORECAST REMAINS DIFFICULT TO ASCERTAIN
JUST IF AND WHEN HIGHER POPS WILL BE REQUIRED THROUGH MOST OF THE
PERIOD.
INITIALLY LOW PRESSURE WILL BE LOCATED OFF THE CAPE FEAR COAST WITH
SHEARED VORTICITY MOVING ACROSS AT THE MID LEVELS. A BAND OF HEAVIER
RAINFALL IS DEPICTED BY THE GFS NEAR THE COAST AND IS REFLECTED IN
THE MOS NUMBERS. I HAVE INCREASED POPS THROUGH 1800 UTC THURSDAY
MOSTLY ALONG THE COAST. THE REMAINDER OF THE POPS WILL BE DICTATED
BY THE MID LEVEL LOW SWINGING ACROSS THE AREA FRIDAY.
I HAVE LOWER VALUES FOR THURSDAY NIGHT ALTHOUGH STILL NOT REMOVING
ENTIRELY INCREASING SOMEWHAT FOR THE FIRST PART OF FRIDAY. OVERALL
THURSDAY LOOKS LIKE THE LAST TIMEFRAME FOR DECENT RAINFALL AS THE
REMAINDER OF THE ACTIVITY WILL BE LIGHT. THERE MAY BE SOME CLEARING
FRIDAY ESPECIALLY SOUTH AS THE SYSTEM FINALLY PULLS AWAY.
TEMPERATURE FORECAST REQUIRED ONLY MINIMAL ADJUSTMENTS TO GRAVITATE
MORE TOWARD THE LATEST GFS/MAV NUMBERS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...FORECAST REMAINS ALL BUT UNCHANGED WITH
THE MORNING UPDATE AS A MOSTLY ZONAL AND RELATIVELY WEAK MID
LEVEL PATTERN DEVELOPS. HIGH PRESSURE WILL MOVE FROM THE
MISSISSIPPI VALLEY TO WELL OFFSHORE...ASSUMING THE BERMUDA
POSITION THAT WE WILL BE SEEING MUCH MORE OF IN THE COMING MONTHS.
DONT SEE ANY POPS IN THE FORECAST. ONE INTERESTING NOTE IS THE
DEVELOPMENT OF A TROPICAL OR MORE LIKE A SUBTROPICAL FEATURE
CONSIDERING WATER TEMPERATURES NEAR THE FLORIDA PENINSULA NEXT
WEEK. BOTH THE GFS AND ECMWF HAVE THIS FEATURE BUT VERY PREMATURE
TO DIAGNOSE AT THIS POINT. STILL SOMETHING TO WATCH. TEMPERATURE
TRENDS REMAIN IN PLACE SLIGHTLY BELOW AVERAGE INITIALLY WARMING TO
ABOVE BY THE END OF THE PERIOD.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...VFR THROUGH THE MORNING HOURS WILL GRADUALLY
DETERIORATE TO MVFR/POTENTIAL IFR LATER TODAY AS LOW
CLOUDS...AREAS OF FOG...AND PERIODS OF RAIN MOVE THROUGH THE
FORECAST AREA.
VFR PREVAILS THIS MORNING WITH LIGHT AND VARIABLE WINDS...AND AS
SEEN FROM LATEST RADAR IMAGERY...LIGHT RAIN SHOWERS AROUND
KFLO/KMYR/KCRE. WILL CONTINUE TO SEE -RA/SHRA INFILTRATE EAST-
NORTHEAST ACROSS THE AREA AND INCREASE IN INTENSITY TODAY AND THIS
EVENING AS LOW PRESSURE CREATES UNSETTLED WEATHER OVER THE NEXT
COUPLE OF DAYS. LIGHT EASTERLY WINDS THIS MORNING WILL BACK TO THE
NORTHEAST TODAY...INCREASING TO AOB 10 KTS...WITH SLIGHTLY HIGHER
POSSIBLY ALONG THE COAST. INTO THE OVERNIGHT HOURS...RAIN WILL
TAPER OFF BUT LOW CLOUDS AND AREAS OF FOG WILL LINGER...CREATING
MVFR/POSSIBLY IFR.
EXTENDED OUTLOOK...A CONTINUING CHANCE FOR SHOWERS WITH POTENTIAL
MVFR/IFR CONDITIONS THROUGH FRIDAY. OTHERWISE EXPECT VFR.
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 WEDNESDAY...THE SUITE OF COMPUTER MODELS AVAILABLE TO US
IS STRUGGLING GREATLY WITH CURRENT WIND DIRECTIONS. OBSERVATIONS
ACROSS THE AREA SHOW VARIABLE WIND DIRECTIONS WITH SPEEDS 6 KNOTS OR
LESS AT THE BEACHES. FARTHER OFFSHORE WHERE THE SYNOPTIC PRESSURE
GRADIENT WOULD SUGGEST A NORTHEAST WIND WE ARE SEEING VARIABILITY
HERE AS WELL DUE TO SHOWERS 20+ MILES OFFSHORE PRODUCING SOME
OUTFLOW WIND EFFECTS. AS THE WEAK LOW OFF THE FLORIDA EAST COAST
BECOMES A LITTLE BETTER ORGANIZED AND MOVES CLOSER THIS AFTERNOON WE
ANTICIPATE EASTERLY WINDS TO BECOME BETTER ESTABLISHED. THERE MAY
STILL BE REMAINING VARIABILITY HOWEVER DUE TO ANOTHER WAVE OF
SHOWERS EXPECTED TO ARRIVE DURING THE MID AFTERNOON HOURS FROM THE
WEST.
I HAVE INCREASED FORECAST SEA HEIGHTS BY 1 FOOT THROUGH THE
REMAINDER OF TODAY. CURRENT WAVE OBSERVATIONS FROM LOCAL BUOYS
INDICATE 2 FEET NEARSHORE AND 3 FEET OUT AT THE FRYING PAN SHOALS
BUOY...ABOUT 1 FOOT HIGHER THEN PREVIOUSLY FORECAST.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...LOW PRESSURE WILL BE ABOUT 150 MILES OFF THE
CAPE FEAR COAST THURSDAY MORNING. THIS SYSTEM WILL MOVE NORTHEAST
DURING THE DAY. WINDS...INITIALLY FROM THE NORTH WILL TURN TO THE
NORTHWEST BY MIDDAY. WIND SPEEDS WILL BE 15-20 KNOTS. WIND SPEEDS
WILL DIMINISH TO A RANGE OF 10-15 KNOTS THURSDAY NIGHT AND CONTINUE
IN THIS RANGE AND DIRECTION FOR MOST OF THE DAY FRIDAY. A SECONDARY
SURGE WILL OCCUR LATE FRIDAY KICKING WINDS BACK UP TO 15-20 KNOTS
DIMINISHING ONCE AGAIN BY SATURDAY MORNING. WITH THIS PATTERN THE
HIGHER SEAS WILL RELEGATED TO THE OUTER WATERS. HEIGHTS WILL MOSTLY
BE 2-4 FEET BUT GUIDANCE IS SHOWING A FEW SIX FOOTERS ACROSS THE NC
WATERS LATE FRIDAY.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...NICE CONDITIONS FOR THE MARINE COMMUNITY
FOR THE EXTENDED PERIOD. A LITTLE BREEZY TO START WITH WINDS FROM
THE NORTHWEST AT 10-15 KNOTS. WINDS WILL QUICKLY SUBSIDE AS HIGH
PRESSURE MOVES EAST ACROSS THE CAROLINAS. SHOULD SEE TEN KNOTS OR
LESS BY SUNDAY MORNING. A RETURN FLOW DEVELOPS LATER SUNDAY WITH
SOUTH TO SOUTHWEST WINDS ONCE AGAIN...TEN KNOTS OR LESS. SEAS WILL
BE 1-3 FEET THROUGHOUT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
146 AM EDT WED APR 29 2015
.SYNOPSIS...
IT WILL BE COOL AND RAINY THROUGH THURSDAY AS LOW PRESSURE MOVES
SLOWLY UP THE SOUTHEAST COAST. SUNSHINE AND SEASONABLE TEMPERATURES
WILL RETURN ON FRIDAY AND THEN PERSIST THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1035 PM TUESDAY...HAVE MADE INCREASES IN CLOUD COVER
OVERNIGHT MORE PROGRESSIVE BASED ON LATEST SATELLITE LOOPS.
OTHERWISE NO CHANGES OF NOTE WITH THE LATEST UPDATE. PREVIOUS
DISCUSSION FROM EARLIER THIS AFTERNOON FOLLOWS:
WEAK SURFACE HIGH PRESSURE COVERS THE CAROLINAS THIS AFTERNOON.
ALL EYES ARE FOCUSED ON AN UPPER LEVEL LOW OVER THE ARKLATEX
REGION MOVING EASTWARD. AHEAD OF THIS LOW BACKING MID-LEVEL FLOW
AND MOISTURE ADVECTION FROM THE GULF WILL LEAD TO INCREASING
CLOUDINESS OVERNIGHT...WITH SOME CHANCE OF RAIN DEVELOPING BY 8 AM
AS FAR NORTH AS FLORENCE & MYRTLE BEACH.
COMPARED TO 00Z THE 12Z MODELS HAVE BECOME (AS A WHOLE) MUCH
DRIER IN THE 06-12Z WINDOW TONIGHT. THE CULPRIT APPEARS TO BE THIS
MORNING`S MCS THAT RAN EAST-SOUTHEASTWARD ACROSS THE GULF OF
MEXICO INTO THE SOUTHERN FLORIDA PENINSULA. DRYING AND
STABILIZATION BEHIND THIS FEATURE HAS LED TO A REDUCTION IN THE
AMOUNT OF MOISTURE SPREADING NORTHEASTWARD TOWARD THE CAROLINAS.
THE 12Z NAM AND RUC ARE THE PREFERRED MODELS...WITH THE 12Z GFS
LIKELY STILL TOO RAPID WITH MOISTURE RETURN. GIVEN THE LESSER
AMOUNT OF CIRRUS STREAMING NORTHWARD THIS EVENING WE SHOULD HAVE
GOOD RADIATIONAL COOLING THROUGH MIDNIGHT...PERHAPS EVEN A FEW
HOURS LONGER ACROSS SE NORTH CAROLINA.
I HAVE ADJUSTED FORECAST LOW TEMPERATURES FOR TONIGHT 3-5 DEGREES
LOWER...BUT AM STILL 1-2 DEGREES ABOVE THE CHILLY 12Z GFS AND NAM
MOS NUMBERS. LOWS SHOULD RANGE FROM THE UPPER 40S TO LOWER 50S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...VERY BUSY UPPER PATTERN IN THE EASTERN
U.S. MAKING FOR SOME FORECAST UNCERTAINTIES. A HUGE BARELY MOVING
UPPER LOW WILL BE LOCATED JUST EAST OF NEW ENGLAND STATES ON
WEDNESDAY. MEANWHILE ANOTHER NORTHERN BRANCH FEATURE WILL BE
DIVING NEARLY DUE SOUTH OUT OF THE GREAT LAKES. A SOUTHERN BRANCH
FEATURE PREVIOUSLY CUTOFF OVER THE PLAINS FOR SOME TIME WILL BE
OPENING UP AND PROGRESSING EAST. THE LATTER TWO FEATURES WILL HAVE
SOME INTERACTION IN PART MODIFIED BY THE UNWILLINGNESS OF THE
FORMER TO PROGRESS EAST. THE SOUTHERN BRANCH FEATURE WILL HAVE A
SLOW MOVING SURFACE REFLECTION THAT CROSSES FLORIDA. THE CONFUSING
ASPECT REGARDING THIS SYSTEM IS THAT IT WILL PICK UP AMPLE GULF
MOISTURE BUT MAY HAVE TROUBLE BRINGING IT FAR ENOUGH NORTH AND
WEST TO BRING THE APPRECIABLE RAINFALL THAT WAS PREVIOUSLY
ANTICIPATED. SO WHILE RAINFALL CHANCES WILL REMAIN VERY HIGH THE
QPF HAS BEEN REDUCED. WHAT APPEARS TO BE THE PROBLEM IS A WEAKENED
LOW LEVEL ISENTROPIC UPGLIDE PAIRED WITH THE FACT THAT THE MID
LEVEL WAVE NOW WEAKENS SUFFICIENTLY TO PREVENT DEEPER COUPLED
ASCENT. THE UPPER WAVE WEAKENS SO RAPIDLY AS IT GETS SHEARED OUT
BETWEEN THE UPSTREAM DIVING VORT AND THE STALWART NEW ENGLAND LOW.
THIS LEADS TO MORE UNCERTAINTY WITH RESPECT TO THURSDAY`S FORECAST
AND THE SPEED AT WHICH PRECIPITATION CHANCES WANE LOCALLY. THE
SECOND DISTURBANCE WILL ATTEMPT TO CAPTURE THE SURFACE WAVE OFF OF
CAPE HATTERAS BUT MOST GUIDANCE SHOWS THE TROUGH AS A WHOLE
REMAINS TOO CONFLUENT/POSITIVELY TILTED TO SUCCEED. ALSO THERE
WILL BE A DRY MOVING UP THE COAST ON THURSDAY AND THE LANDMASS IS
MORE LIKELY TO FIND ITSELF IN THE WRAP-AROUND REGION. HEADING INTO
THURSDAY NIGHT IT IS TOUGH TO GO WITH A DRY FORECAST ESPECIALLY
OVER NORTHERN ZONES GIVEN THE STRENGTH OF THE SHEARED VORTICITY
AND THE COLD AIR ALOFT BEARING DOWN UPON THE AREA FROM THE NORTH
AND WEST.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...SOUTHERN EDGE OF 5H LOW PASSES OVER THE
AREA DURING FRI BUT PRECIP CHANCES REMAIN RATHER LOW. INSTABILITY
UNDER THE LOW SHOULD BE ENHANCED BUT THERE IS A DISTINCT LACK OF
DEEP MOISTURE. SOME WRAP AROUND MOISTURE DOES ARRIVE LATER IN THE
DAY BUT AT THAT POINT THE LOW IS SHIFTING OFF TO THE NORTHEAST
WITH SUBSIDENCE OVERHEAD. THE 5H LOW CONTINUES MOVING NORTHEAST
FOR THE WEEKEND WITH SURFACE HIGH PRESSURE BUILDING IN UNDER
WEAKLY AMPLIFIED FLOW ALOFT. CENTER OF THE SURFACE HIGH SHIFTS
OFFSHORE EARLY NEXT WEEK...MIGRATING TO NEAR BERMUDA BY MIDWEEK.
ALOFT THE WEAKLY AMPLIFIED MID LEVEL PATTERN...RESULTING IN
NORTHWEST FLOW DURING THE WEEKEND...WILL TRANSITION TO WEAK
RIDGING FOR THE START OF NEXT WEEK. THIS WILL HELP MAINTAIN DRY
CONDITIONS THROUGH THE END OF THE FORECAST PERIOD. TEMPERATURES
SLIGHTLY BELOW CLIMO TO START THE PERIOD WILL CLIMB ABOVE CLIMO
EARLY NEXT WEEK AS RETURN FLOW DEVELOPS AROUND THE WEST SIDE OF
THE BERMUDA HIGH.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...WINDS EARLY THIS MORNING WILL BE LIGHT AND VARIABLE.
CIGS WILL GRADUALLY LOWER THROUGH 12Z BUT REMAIN VFR. ALTHOUGH SOME
RAIN COULD DEVELOP EARLIER...GENERALLY LIGHT RAIN WILL MOVE INTO THE
KMYR/KFLO/KCRE TERMINALS AROUND 11-12Z WITH MID LEVEL CIGS
DEVELOPING. THE RAIN WILL GRADUALLY SPREAD ACROSS THE REMAINING
TERMINALS DURING THE MORNING HOURS AND INCREASE IN INTENSITY BY
AFTERNOON. WORSE FLIGHT CONDITIONS WILL BE AT THE SOUTHERN TERMINALS
AND BEST AT KLBT. VFR MAY CONTINUE WELL INTO THE AFTERNOON AT BOTH
KLBT/KILM. DURING THE AFTERNOON MVFR WILL DEVELOP AT KFLO AND IFR AT
KCRE/KMYR WITH BEST CONFIDENCE KMYR. LIGHT WINDS DURING THE MORNING
WILL BECOME E...THEN GRADUALLY BACK TO NE 5-10KT EXCEPT 10-15KT AT
KMYR AS A SURFACE LOW PASSES TO THE SOUTHEAST. LITTLE CHANGE IN
CLOUDS DURING THE EVENING AS RAIN DECREASES.
EXTENDED OUTLOOK...A CONTINUING CHANCE FOR SHOWERS WITH POTENTIAL
MVFR/IFR CONDITIONS THROUGH FRIDAY. VFR SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1035 PM TUESDAY...NO CHANGES FROM EARLIER UPDATE. HIGH
PRESSURE CENTER SITTING DIRECTLY OVER THE COASTAL WATERS LEADING
TO LIGHT WINDS WITH SEAS OF 2 FT OR LESS. THESE BENIGN CONDITIONS
WILL PERSIST OVERNIGHT. PREVIOUS DISCUSSION FROM EARLIER THIS
AFTERNOON FOLLOWS:
WEAK HIGH PRESSURE PUSHING INTO THE CAROLINAS HAS HELPED DIMINISH
THE STRONGER WINDS ASSOCIATED WITH A NORTHERLY SURGE EARLY THIS
MORNING. LIGHT NORTHERLY WINDS CONTINUE AWAY FROM SHORE...WHILE
NEARSHORE A SEABREEZE CIRCULATION HAS ALLOWED ONSHORE WINDS TO
DEVELOP MAINLY SOUTH OF CAPE FEAR. THE HIGH SHOULD SLIDE EAST AND
OFF THE COAST TONIGHT WITH WINDS BECOMING GENERALLY
EASTERLY...STRONGEST ACROSS THE SOUTH CAROLINA WATERS WHERE THE
PRESSURE GRADIENT SHOULD BE STRONGER DUE TO GREATER DISTANCE FROM
THE HIGH.
SEAS ARE CURRENTLY AROUND 2 FEET WITHIN 20 MILES OF THE COAST.
THESE SHOULD FALL TO 1-2 FEET OVERNIGHT...MOSTLY DUE TO THE 4-5
SECOND WIND WAVE DYING AWAY WITH THE 8-9 SECOND SOUTHEAST SWELL
CONTINUING.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WEDNESDAY WILL BRING A LIGHT
ONSHORE/EASTERLY FLOW AS HIGH PRESSURE GIVES UP ITS INFLUENCE OVER
THE REGION WHILE AT THE SAME TIME AN AMORPHOUS LOW WILL BE
CONGEALING OVER THE NORTHEAST GOMEX AND FLORIDA PENINSULA.
DEPENDING ON THE SHAPE, SPEED, AND TRACK OF THIS LOW THE LOCAL
WINDS MAY VEER SLIGHTLY AND INCREASE A FEW KNOTS. THERE IS SOME
UNCERTAINTY HOWEVER AND SOME MODELS SHOW LIGHTER WINDS BUT HAVE
DECIDED TO ERR ON THE SIDE OF CAUTION. THIS FEATURE WILL MOVE VERY
SLOWLY AND SO STILL BE THE DOMINANT PLAYER ON THURSDAY. THE
PROXIMITY OF CYCLONIC FLOW ALWAYS LEADS TO A CONSIDERABLE CHANGE
IN WIND DIRECTION AS THE DAY WEARS ON AND THIS APPEARS TO BE THE
CASE ON THURSDAY WITH AN EVENTUAL TURN TO OFFSHORE. FORTUNATELY
THROUGH THE ENTIRE PERIOD WIND AND SEAS NEVER BUILD ABOVE ANY
THRESHOLDS THOUGH THE VARIABLE DIRECTIONS WILL KEEP DOMINANT
PERIODS RATHER SHORT AND CONDITIONS CHOPPY.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...MODEST OFFSHORE FLOW AT THE START OF THE
PERIOD WILL GRADUALLY WEAKEN ON SAT AND BEGIN BACKING TO THE
SOUTHWEST SAT NIGHT AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST.
WEAKENING GRADIENT WILL LEAD TO SPEEDS DROPPING FROM A SOLID 20 KT
FRI TO 10 KT OR LESS LATER SAT. AS THE HIGH MOVES OFFSHORE SAT
NIGHT INTO SUN WINDS WILL BECOME LIGHT AND VARIABLE WITH SOUTHWEST
FLOW BECOMING ESTABLISHED BY THE END OF THE PERIOD. SEAS MAY
BRIEFLY REACH 5 FT WELL AWAY FROM SHORE LATE FRI AND FRI NIGHT BUT
GENERALLY 3 TO 4 FT CAN BE EXPECTED INTO SAT. SEAS WILL SUBSIDE AS
WIND SPEEDS DECREASE...DROPPING TO 2 TO 3 FT LATE SAT AND SUN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK/TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...RJD/MRR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
957 PM CDT THU APR 30 2015
.UPDATE...
ISSUED AT 956 PM CDT THU APR 30 2015
FORECAST FOR THE REMAINDER OF THE NIGHT REMAINS ON TRACK AS THE
COLD FRONT HAS EXITED INTO THE RED RIVER VALLEY. FOLLOWING TRENDS
IN THE 00-01 UTC HRRR ITERATIONS...POST-FRONTAL RAIN SHOWERS ARE
EXPECTED TO CONTINUE ACROSS THE JAMES RIVER VALLEY THROUGH 06-07
UTC.
UPDATE ISSUED AT 704 PM CDT THU APR 30 2015
QUICK UPDATE TO EXPIRE THE RED FLAG WARNING ON TIME AT 00 UTC. AS
OF 00 UTC...THE SURFACE COLD FRONT WAS LOCATED FROM FAR NORTHEAST
NORTH DAKOTA THROUGH LAKE OAHE...WITH LIGHT RAIN ALONG AND BEHIND
THE FRONT. HOWEVER...A SIGNIFICANT PORTION OF THIS PRECIPITATION
WAS NOT REACHING THE GROUND ACROSS THE SOUTH CENTRAL.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 244 PM CDT THU APR 30 2015
MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE FIRE WEATHER
CONCERNS THIS AFTERNOON...AND AGAIN FRIDAY AFTERNOON.
CURRENTLY...A COLD FRONT IS SITUATED FROM AROUND BOTTINEAU TO
BISMARCK. AHEAD OF THE FRONT...SOUTHERLY WINDS 15 TO 20 MPH WITH
GUSTS OF 25 TO 30 MPH. THIS IS RESULTING IN MINIMUM HUMIDITIES
AROUND 25 PERCENT FROM SOUTHEAST EMMONS COUNTY...TO THE UPPER
TEENS OVER THE JAMES RIVER VALLEY. CRITICAL FIRE WEATHER CRITERIA
IS MARGINAL OVER THE THE WESTERN PORTION OF THE WARNING BUT WINDS
WILL INITIALLY BE GUSTY BEHIND THE FRONT...SO ALTHOUGH HUMIDITIES
WILL RISE WITH THE FRONTAL PASSAGE...WILL KEEP THE RED FLAG
WARNING IN EFFECT UNTIL AFTER THE FRONTAL PASSAGE WHEN WINDS
DIMINISH AND HUMIDITIES RISE.
WILL KEEP THE MENTION OF AFTERNOON THUNDER...ALTHOUGH CHANCES WILL
BE MINIMAL.
TONIGHT...SHOWERS WILL END ACROSS CENTRAL NORTH DAKOTA THIS
EVENING...WITH MOSTLY CLEAR SKIES DEVELOPING WEST TO EAST
OVERNIGHT. LOWS WILL BE IN THE MID 30S WEST TO MID 40S SOUTHEAST.
FRIDAY...MOSTLY SUNNY AND CONTINUED MILD FRIDAY BEHIND THE FRONT
WITH A WEST TO SOUTHWEST SURFACE FLOW. BUFR SOUNDINGS INDICATE
SUSTAINED WINDS 15 TO 20 MPH FRIDAY AFTERNOON WITH GUSTS OF 25 TO
30 MPH...ACROSS THE NORTHWEST AND NORTH CENTRAL. WITH MINIMUM
HUMIDITIES AROUND 20 PERCENT...CRITICAL FIRE WEATHER CONDITIONS
WILL BE POSSIBLE. WILL ISSUE A FIRE WEATHER WATCH FOR PORTIONS OF
THE WEST CENTRAL..THE NORTHWEST AND NORTH CENTRAL 18Z FRIDAY TO
00Z SATURDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 244 PM CDT THU APR 30 2015
CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS THROUGH THE WEEKEND WITH
THE POTENTIAL FOR CONSIDERABLE RAIN BY MID WEEK...HIGHLIGHTS THE
LONG TERM.
THE CURRENT MODEL PACKAGE PROVIDES GOOD AGREEMENT ON AN UPPER LEVEL
TROUGH DEVELOPING AND MOVING EASTWARD ACROSS THE CENTRAL CANADIAN
PLAINS THROUGH THE WEEKEND. SHOWERS AND THUNDERSTORMS ARE POSSIBLE
AHEAD OF THE ASSOCIATED SURFACE FRONT. THE GREATEST CHANCES FOR
THUNDERSTORM ACTIVITY LOOK TO BE IN THE SOUTHEAST.
THEREAFTER...ZONAL FLOW ALOFT WILL TRANSITION TO SOUTHWESTERLY FLOW
AHEAD OF AN UPPER LEVEL TROUGH DIGGING INTO THE PACIFIC
NORTHWEST...EARLY NEXT WEEK. AS A RESULT...LEE TROUGHING IS EXPECTED
AT THE SURFACE WITH MOISTURE TRANSPORT AND ATMOSPHERIC INSTABILITY
CREATING WIDESPREAD CHANCES FOR SHOWERS AND THUNDERSTORMS. ALTHOUGH
MODELS HAVE SHOWN CONSISTENT AGREEMENT ON OVERALL PRECIPITATION
DEVELOPMENT...TIMING/LOCATION REMAINS UNCERTAIN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 956 PM CDT THU APR 30 2015
AS OF 0230 UTC...A COLD FRONT ACROSS EASTERN NORTH DAKOTA WAS
CONTINUING TO MOVE EAST WITH LIGHT RAIN IN THE VICINITY OF THE
FRONT. SKIES WILL CONTINUE TO CLEAR FROM WEST TO EAST TONIGHT
ACROSS NORTH DAKOTA. SOME FOG MAY BE POSSIBLE EAST LATE TONIGHT
INTO EARLY FRIDAY MORNING. HOWEVER...GIVEN UNCERTAINTY...WILL
LEAVE OUT OF THE KJMS TAF FOR NOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING
FOR NDZ001>005-009>013-017>019-021-031-032.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...AC
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
552 PM CDT WED APR 29 2015
.UPDATE...
ISSUED AT 551 PM CDT WED APR 29 2015
NO SIGNIFICANT CHANGES WITH THIS UPDATE OTHER THAN TO EXPAND THE
ISOLATED SHOWER MENTION ACROSS THE WEST LATE TONIGHT GIVEN TRENDS
IN THE 19-21 UTC HRRR ITERATIONS WHICH PROPAGATE SHOWERS ALONG
THE COLD FRONT ACROSS THE MONTANA BORDER AROUND 10 UTC.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 317 PM CDT WED APR 29 2015
CURRENTLY...SUNNY SKIES ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. AS UPPER LEVEL RIDGING MOVES INTO WESTERN AND
CENTRAL NORTH DAKOTA. CURRENT TEMPERATURES ARE IN THE UPPER 60S TO
LOWER 70S STATEWIDE. SURFACE HIGH PRESSURE WAS LOCATED OVER THE
EASTERN DAKOTA AND MINNESOTA WITH DEVELOPING LOW PRESSURE IN THE
LEE OF THE CANADIAN AND NORTHERN ROCKIES.
TONIGHT...EXPECT MAINLY CLEAR SKIES...BUT SHOULD SEE INCREASING
CLOUDS WEST TOWARD MORNING AS THE MID-UPPER LEVEL RIDGE PUSHES
INTO MINNESOTA AND SOUTHWEST FLOW ALOFT BRINGS INCREASING MID
LEVEL MOISTURE INTO THE WEST. A SHORTWAVE TRACKING ACROSS THE
NORTHERN ROCKIES IS SITUATED OVER NORTH CENTRAL MONTANA WITH AN
ASSOCIATED SURFACE COLD FRONT OVER WESTERN NORTH DAKOTA.
INCREASING 850MB WINDS AHEAD OF THE FRONT WITH THERMAL RIDGING
MOVING INTO THE AREA SHOULD KEEP OVERNIGHT LOWS MILD WITH READINGS
GENERALLY IN THE 40S.
THURSDAY...THE UPPER LEVEL TROUGH MOVES INTO EASTERN MONTANA
AROUND MIDDAY AND INTO WESTERN NORTH DAKOTA BY EARLY EVENING. THIS
WILL PUSH THE COLD FRONT TO NEAR THE HIGHWAY 83 CORRIDOR BY
MIDDAY. AHEAD OF THE COLD FRONT WARM SOUTH TO SOUTHWEST WINDS
SHOULD BUMP TEMPERATURES INTO THE LOW TO MIDDLE 70S. THE DRY
SOUTHWEST FLOW SHOULD ALLOW DEWPOINT TEMPERATURES TO FALL TO THE
LOW TO MID 30S SOUTH CENTRAL...AND INTO THE LOWER 30S OVER THE
JAMES RIVER VALLEY. AS WE MIX OUT IN THE AFTERNOON...WE SEE THE
POTENTIAL FOR SUSTAINED WINDS AROUND 20 MPH WITH GUSTS TO AROUND
30 MPH OVER THE JAMES RIVER VALLEY...TAPERING SLIGHTLY AS YOU GO
WEST TO THE MISSOURI RIVER VALLEY. THIS PRODUCE AFTERNOON
HUMIDITIES FROM THE UPPER TEENS IN THE SOUTHERN JAMES RIVER
VALLEY...TO THE MID TO UPPER 20S ALONG THE MISSOURI RIVER. WILL BE
ISSUING A RED FLAG WARNING DUE TO THE LOW HUMIDITIES AND STRONG
WINDS THURSDAY AFTERNOON INTO THE EARLY EVENING.
NORTHWEST WINDS BEHIND THE COLD FRONT WILL BRING IN COOLER
AIR...RAISING HUMIDITIES AND BRINGING A CHANCE OF SHOWERS.
INSTABILITY IS LIMITED BUT DID MENTION AN ISOLATE THUNDERSTORM
THURSDAY AFTERNOON. CRITICAL FIRE WEATHER ISSUES ARE EXPECTED TO
DIMINISH WITH THE PASSAGE OF THE COLD FRONT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 317 PM CDT WED APR 29 2015
AS AN UPPER LEVEL TROUGH...LOCATED OVER SASKATCHEWAN AND EASTERN
NORTH DAKOTA...CONTINUES EASTWARD ACROSS THE NORTHERN
PLAINS...CHANCES FOR RAIN WILL PERSIST IN CENTRAL AND EASTERN AREAS
OF THE STATE THROUGH THURSDAY NIGHT.
THEREAFTER...THE CURRENT ENSEMBLE AND DETERMINISTIC MODELS PROVIDE
AGREEMENT ON ZONAL FLOW BECOMING DOMINANT THE THROUGH PERIOD.
SEVERAL EMBEDDED UNPREDICTABLE SHORTWAVES ARE PROJECTED WITHIN THE
UPPER LEVEL FLOW...CREATING FREQUENT CHANCES FOR RAIN AND THE
POSSIBILITY FOR THUNDERSTORMS. THIS WEEKEND LOOKS TO BE THE BEST
CHANCES FOR WIDESPREAD RAIN WITH THUNDERSTORMS MOSTLY CONFINED TO
SOUTHERN AREAS OF THE STATE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 550 PM CDT WED APR 29 2015
A COLD FRONT ACROSS CENTRAL MONTANA THIS EVENING WILL MOVE ACROSS
WESTERN AND CENTRAL NORTH DAKOTA THURSDAY MORNING AND INTO THE
AFTERNOON. ISOLATED TO SCATTERED SHOWERS AND POSSIBLY A
THUNDERSTORM ARE EXPECTED ALONG THE FRONT. SOUTHERLY WINDS
GUSTING NEAR 30 KTS AHEAD OF THE FRONT WILL CHANGE TO THE WEST
BEHIND THE FRONT. VFR CONDITIONS EXPECTED OUTSIDE OF SHOWERS AND
THUNDERSTORMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TO 7 PM CDT THURSDAY FOR NDZ023-025-
036-037-046>048-050-051.
&&
$$
UPDATE...AYD
SHORT TERM...AC
LONG TERM...TWH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
800 PM EDT THU APR 30 2015
.SYNOPSIS...
VIGOROUS MID/UPPER LOW PRESSURE CROSSES TO OUR SOUTHEAST TONIGHT.
INSTABILITY SHOWERS THEN LINGERING LOWER CLOUDS/SHOWERS OVERNIGHT.
HIGH PRESSURE FOR THE WEEKEND...WITH A WARMING TREND INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
800 PM UPDATE...
NOT MUCH CHANGE IN THE FCST WITH THE EVE UPDATE. FINESSED POPS
USING LATEST HRRR AS A BASE WHICH PIVOTS BANDS OF SHRA THRU
OVERNIGHT ACROSS S ZONES.
PREVIOUS DISCUSSION BELOW...
AN UPPER LEVEL LOW PRESSURE SYSTEM DROPS SOUTH INTO OH
TONIGHT...TURNING SOUTHEAST ACROSS EASTERN KY OVERNIGHT. SCATTERED
SHOWERS ARE NOTED ALONG THE PERIPHERY OF THIS CIRCULATION WITH
EMBEDDED THUNDERSTORMS SOUTH AND WEST OF ITS CENTER. TONIGHT THE
WEATHER REMAINS UNSETTLED WITH LIGHT SHOWERS DRIFTING EAST. FEW
THUNDERSTORMS CAN BE POSSIBLE ACROSS THE EXTREME SOUTHERN PORTIONS
OF WV...NORTHEAST OH...AND SOUTHWEST VA TONIGHT. AS THE LOW EXITS
SOUTHEAST...IMPROVING CONDITIONS WILL SPREAD FROM WEST TO EAST
EARLY FRIDAY.
MODELS SUGGEST THAT ABUNDANT LINGERING MOISTURE WILL PROVIDE FOR
LOW LEVEL CLOUDS OVERNIGHT INTO EARLY FRIDAY. BUFKIT SOUNDINGS
INDICATE DRIER AIR FILTERS IN FROM THE WEST LATE FRIDAY...PERHAPS
BRINGING PERIODS OF SUNSHINE DURING THE AFTERNOON HOURS ACROSS
SOUTHEAST OH.
WITH ABUNDANT CLOUDINESS...TEMPERATURES TONIGHT WILL BE IN THE
40S. FRIDAY...TEMPERATURES WILL RANGE FROM THE MID 60S
LOWLANDS...INTO THE MID 50S HIGHEST ELEVATIONS. WENT CLOSER TO THE
COOLER BIAS CORRECTED ECMWF FOR LOWS TONIGHT...AND WITH THE
CONSENSUS RAW FOR HIGHS ON FRIDAY.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
INSTABILITY AND LOW LEVEL UPSLOPE FLOW WANE FRI EVENING WITH LOSS OF
HEATING AND UPPER LEVEL TROUGH PULLING AWAY. ANY MOUNTAIN SHOWERS
WILL DIE OFF BY MIDNIGHT AS A RESULT.
OTHERWISE HIGH PRESSURE SAILS SLOWLY ACROSS THE AREA THIS WEEKEND TO
PROVIDE NICE WEATHER. UPPER LEVEL RIDGING BUILDS TO THE W OF THE
FCST AREA...BUT A WEAK S/W TROUGH CROSSING LATE SAT AND AN EVEN
WEAKER ONE LATE SUNDAY WILL BRING SOME MID AND HIGH CLOUD...AND
THERE WILL ALSO BE SOME AFTERNOON CU...SO THE DAYTIME HOURS WILL
BRING A MIX OF CLOUDS AND SUNSHINE. LEFT THE SCHC FOR A SHOWER IN
THE WV MOUNTAINS SAT AFTERNOON ON ELEVATED HEATING...ALTHOUGH THE
AREA MAY BE UNDERNEATH WEAK RIDGING BETWEEN THE EXITING UPPER LEVEL
TROUGH...AND THE S/W COMING FROM THE W WHICH CROSSES SAT AFTERNOON
AND NT.
TEMPERATURES ARE CLOSE TO GUIDANCE AND NORMAL IN THIS RELATIVELY
TRANQUIL PATTERN...EXCEPT HIGHS SAT WERE A LITTLE ABOVE GUIDANCE AND
WERE LEFT ALONE IN LIGHT OF EARLY MAY SUNSHINE. TRIED TO TWEAK
HIGHS SUNDAY UPWARD TOWARD THE LATEST MEX...AGAIN IN TH EARLY MAY
SUN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
USED THE ECMWF ENSEMBLE MEAN AS THE BASIS FOR THE FORECAST. THIS
WOULD HAVE HIGH PRESSURE IN CONTROL FOR SUNDAY NIGHT AND MONDAY.
WITH THE HIGH SLIDING EASTWARD...MOISTURE INCREASES. THIS MAY ALLOW
FOR SOME AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ON TUESDAY.
BY WEDNESDAY...A FRONTAL BOUNDARY ATTEMPTS TO SLIDE INTO SOUTHEAST
OHIO AND NORTHERN WEST VIRGINIA BEFORE RETURNING BACK NORTHWARD ON
THURSDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR CONDITION WILL SLOWLY DETERIORATE TO MVFR ALONG WITH SHOWERS
ASSOCIATED WITH AN UPPER LEVEL LOW PRESSURE SYSTEM PASSING THRU. THE
LINE OF MAINLY SHOWERS WILL GRADUALLY PIVOT S TONIGHT. THUNDER CAN
NOT BE RULED OUT AT BKW WHEN THE LINE PASS THROUGH THERE THIS EVE...BUT
PROBABILITIES ARE TOO LOW TO INCORPORATED IN TAF AT THIS TIME.
MODELS SUGGEST LOW STRATUS DEVELOPING OVERNIGHT TO PRODUCE
MVFR/IFR CIGS AT MOST PLACES. BOUNDARY LAYER WINDS ARE ABOUT 5
TO 10 KNOTS...THEREFORE...FOG WILL STRUGGLE TO FORM AT MOST
PLACES...EXCEPT ALONG DEEPER RIVER VALLEYS. LOW CEILINGS SHOULD
LAST THROUGH 13-14Z. IMPROVING CONDITIONS ARE EXPECTED AFTER 15Z
WITH KCRW/KBKW THE LAST TO IMPROVE TO VFR BKN CIGS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: LOWERING CIG TONIGHT MAY TAKE LONGER TO
DEVELOP THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE FRI 05/01/15
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H M H H H H M H H H H H
HTS CONSISTENCY H H H H H H H M M M H H
BKW CONSISTENCY M M M L L H H H M M H H
EKN CONSISTENCY H H M L L L L L L H H H
PKB CONSISTENCY H H H H H H H M L L L L
CKB CONSISTENCY H H M M H H M M M M L L
AFTER 00Z SATURDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/TRM/RPY
NEAR TERM...ARJ/30
SHORT TERM...TRM
LONG TERM...RPY
AVIATION...30/ARJ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1106 PM EDT THU APR 30 2015
.SYNOPSIS...
A WEAK SURFACE LOW AND ASSOCIATED NORTH/SOUTH TROUGH WILL REMAIN
NEARLY STATIONARY OVER CENTRAL AND WESTERN PENNSYLVANIA OVERNIGHT
AND FRIDAY AS AN UPPER LOW DROPS SLOWLY SOUTHEAST FROM THE MIDDLE
OHIO RIVER VALLEY. HIGH PRESSURE WILL THEN DRIFT SLOWLY FROM THE
TENNESSEE VALLEY TO THE EAST COAST BY THE END OF THE
WEEKEND...LEADING TO WARMER TEMPERATURES THAT WILL CONTINUE
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
1030 PM UPDATE...SLOWLY WEAKENING /1008MB/ MESO LOW HAS DRIFTING A
BIT TO THE NE AND IS NOW LOCATED NEAR KIPT. A SFC TROUGH TRAILING
SSW FROM THE LOW ALONG THE I-99 CORRIDOR WAS COMBINING WITH BROAD
UPPER LEVEL DIVERGENCE TO PRODUCE NUMEROUS...WWD DRIFTING LIGHT
TO MDT RAIN SHOWERS ACROSS THE SRN TWO THIRDS OF THE STATE.
THE SHOWERS WILL SLOWLY DECREASE IN CVRG OVERNIGHT...BECOMING
WIDELY SCT INTO THE PREDAWN HOURS. ADDITIONAL RAINFALL AMOUNTS
WILL BE GENERALLY 0.10 TO 0.25 OF AN INCH...BUT SOME SPOTTY 0.5 OF
AN INCH AMTS AREN/T OUT OF THE QUESTION ACROSS THE LAURELS.
TEMPS WILL SLOWLY COOL OFF INTO THE 40S AND THERE COULD BE SOME
PATCHY FOG FORMING WHERE WINDS LIGHTEN UP A BIT IN THE MORE
PROTECTED VALLEYS THAT EXPERIENCED RAIN TODAY.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
LOWER CLOUDS SHOULD BURN AWAY...BUT IT WILL STAY COOL WITH SOME
AFTN INSTABILITY DEVELOPING SINCE THE UPPER HEIGHTS WILL STILL BE
LOW-ISH. SHOWERS MAY THEN DEVELOP OVER THE ALLEGHENIES. WILL KEEP
SCT SHRA IN THE FCST THERE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
BROAD ZONAL FLOW IS FORECAST TO EXPAND EASTWARD INTO THE REGION
DURING THE LONG TERM PERIOD. HOWEVER...THE ACTIVE NRN AND SRN
STREAM WILL CONTINUE LEADING TO SEVERAL CHANCES AT FRONTAL
PASSAGES DURING THE PERIOD.
LINGERING CYCLONIC FLOW ALOFT COULD LEAD TO THE CHANCE OF A SHOWER
SATURDAY...BUT THE TREND BOTH WEATHER AND TEMPERATURE-WISE WILL BE
FOR IMPROVING CONDITIONS AS WE ENTER NEXT WEEK...MUCH MORE
APPROPRIATE FOR MID SPRING THAN WHAT WE HAVE RECENTLY BEEN
EXPERIENCING.
NAEFS SHOWS AN UPPER RIDGE REPLACING OUR TROUGH BY EARLY NEXT
WEEK...WITH ABOVE NORMAL 500MB HEIGHTS AND 850 TEMPS MOVING IN
FOR THE TUESDAY THROUGH THE END OF THE WEEK TIME FRAME.
WITH THE NORTHERN EDGE OF THE SUBTROPICAL RIDGE BEING PROGGED UP
INTO THE LOWER GR LAKES...PATTERN HINTS THAT WE WILL BECOME
VULNERABLE FOR UPSTREAM CONVECTIVE ACTIVITY TO BE FUNNELED INTO
THE LOCAL AREA. THE FIRST CHANCE FOR THIS LOOKS TO BE SOME TIME
LATER MONDAY INTO TUESDAY...BUT HARD TIMING AT THIS RANGE IS
IMPOSSIBLE.
AS THE HIGH PUSHES OFF THE E COAST...RETURN SW FLOW WILL ADVECT
INCREASINGLY WARM AIR INTO PA. GEFS AND ECENS MEAN 8H TEMPS RISE
TO BTWN 10-12C BY EARLY NEXT WEEK...IMPLYING WIDESPREAD 70S FOR
HIGHS.
MID WEEK NEXT WEEK A FRONTAL BOUNDARY LOOKS TO MOVE SOUTH THROUGH
THE STATE THEN STALL NEARBY. SO DESPITE A WARMER PATTERN...MID
WEEK MAY TURNOUT RATHER MOIST AND NOT AS WARM UNDER A BUILDING
RIDGE OVERHEAD.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
SHOWER AND ISOLATED THUNDERSTORM ACTIVITY SLOWLY DIMINISHING FROM
THE NORTH AND EAST...WHILE CONTINUING ACROSS THE SOUTHERN HALF OF
CENTRAL PENNSYLVANIA. THIS IS WELL DEPICTED IN THE HRRR SHORT
RANGE MODEL. FOLLOWING THIS TREND AND THE HRRR GUIDANCE...WOULD
ANTICIPATE MOST SHOWER ACTIVITY TO BE OUT OF THE REGION BY 06Z.
LIGHT WINDS OVERNIGHT...COUPLED WITH THE RAINFALL THAT HAS
AFFECTED MOST TAF LOCATIONS...SHOULD LEAD TO AT LEAST MVFR...AND
AREAS OF IFR...VSBYS AND CIG FORMATION OVERNIGHT.
WITH NO GOOD DRYING PUSH IN THE AM...EXPECT RESTRICTIONS TO SLOWLY
IMPROVE DURING THE MORNING ON FRIDAY...WITH MOST LOCATIONS BACK
TO VFR TO BETWEEN 14Z AND 16Z. KJST MAY BE THE EXCEPTION...WITH
MVFR CONDITIONS LINGERING WELL INTO THE AFTERNOON.
SOME INSTABILITY AGAIN ON FRIDAY AFTERNOON...WITH MORE LIMITED
SHOWER ACTIVITY. HAVE REINTRODUCED VCSH INTO NORTHERN AND WESTERN
TAFS FOR TOMORROW AFTERNOON. HOWEVER...DESPITE THE SCATTERED
SHOWERS...GENERALLY VFR THROUGH THE DAY.
HIGH PRESSURE THEN MOVES IN FROM THE WEST THROUGH MONDAY WITH
MAINLY VFR CONDITIONS. APPROACHING FRONT MAY TRIGGER SOME SHOWERS
IN THE NORTH ON TUESDAY.
OUTLOOK...
SAT-MON...GENERALLY VFR.
TUE...VFR...WITH SHRA IN THE NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...LA CORTE/GARTNER
AVIATION...JUNG/DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
848 PM EDT THU APR 30 2015
.SYNOPSIS...
A WEAK SURFACE LOW AND ASSOCIATED NORTH/SOUTH TROUGH WILL REMAIN
NEARLY STATIONARY OVER CENTRAL AND WESTERN PENNSYLVANIA OVERNIGHT
AND FRIDAY AS AN UPPER LOW DROPS SLOWLY SOUTHEAST FROM THE MIDDLE
OHIO RIVER VALLEY. HIGH PRESSURE WILL THEN DRIFT SLOWLY FROM THE
TENNESSEE VALLEY TO THE EAST COAST BY THE END OF THE
WEEKEND...LEADING TO WARMER TEMPERATURES THAT WILL CONTINUE
THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
7 PM UPDATE... WEAK /1005MB/ MESO LOW LOCATED ACROSS SCENT PENN
EARLY THIS EVENING...WAS HELPING TO FOCUS CLUSTERS OF SHRA AND
SCATTERED TSRA WITH BRIEF HEAVY RAIN AND SMALL HAIL. THE
PREVIOUSLY STRONGEST AREA OF CONVECTION /HEADING WNW INTO THE
LAURELS ATTM/ SENT AN OUTFLOW BOUNDARY WELL TO IT/S NORTH...AND IT
JUST PUSHED THROUGH THE KUNV AREA WITH SOME SOUTHERLY WIND GUSTS
OF JUST 15-20 KTS.
EXPECT THE AREAL COVERAGE OF THE SHOWERS TO BE NEAR IT/S PEAK AT
23Z...BASED ON THE COLLOCATION OF THE MESO LOW...AREA OF BEST
UPPER LEVEL DIVERGENCE TO THE NE OF THE DIGGING OHIO VALLEY UPPER
LOW...A SLOWLY EWD DRIFTING INVERTED TROUGH NEAR THE I-99
CORRIDOR...AND SOME VERY WEAK MIXED- LAYER CAPE OF AROUND 100 J/KG
EXTENDING FROM NEAR KTHV TO KUNV AND KBFD.
THE SLOW MOTION OF THESE STORMS MAY CREATE POCKETS OF HEAVY
RAIN...BUT THE LOW PWATS PLAY INTO WIDESPREAD FLOODING IS NOT
ANTICIPATED. AN SPS/S OR FLS/S SHOULD HANDLE WHAT OCCURS. THE NRN
HALF OF THE AREA WILL LACK THE ENERGY AND INSTABILITY TO SUSTAIN
THE SHOWERS AS LONG AS THE SRN TIER WILL. HOWEVER...WEAK SHOWERS
WILL LINGER THERE INTO THE EVENING AS WELL. THE EASTERN EDGE OF
THE CWA WILL JUST ABOUT BE THE EASTERN EDGE OF THE SHOWERS.
THE CONVECTION WILL SLOWLY DECREASE IN CVRG AND INTENSITY THIS
EVENING...BECOMING WIDELY SCT SHRA FOR THE REST OF THE NIGHT.
TEMPS EARLY THIS EVENING RANGED FROM THE CHILLY MID AND UPPER 40S
ACROSS THE LAURELS /WHERE THE CONVECTION HAS BEEN THE HEAVIEST AND
MOST PERSISTENT/...TO THE MID 60S IN THE SUSQ VALLEY.
NIGHTTIME STABILITY WILL HELP THE SHOWERS DIMINISH BUT NOT STOP
TOTALLY ACROSS THE SRN TIER. SOME LOWER CLOUDS/FOG AND POSSIBLY
DRIZZLE COULD OCCUR WHERE THE RAIN IS HEAVIEST EARLIER IN THE
NIGHT. WILL NOT MENTION THAT - BUT JUST LEAVE ALL THE MENTIONS AS
JUST /SHOWERS/. MINS WILL HOLD MILD WITH PLENTY OF CLOUDS OVER
MOST OF THE AREA. BUT DEWPOINTS WILL BE LOWER AND CIGS HIGHER IN
THE NE/E. SO...LESS COVERAGE THERE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
LOWER CLOUDS SHOULD BURN AWAY...BUT IT WILL STAY COOL WITH SOME
AFTN INSTABILITY DEVELOPING SINCE THE UPPER HEIGHTS WILL STILL BE
LOW-ISH. SHOWERS MAY THEN DEVELOP OVER THE ALLEGHENIES. WILL KEEP
SCT SHRA IN THE FCST THERE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
BROAD ZONAL FLOW IS FORECAST TO EXPAND EASTWARD INTO THE REGION
DURING THE LONG TERM PERIOD. HOWEVER...THE ACTIVE NRN AND SRN
STREAM WILL CONTINUE LEADING TO SEVERAL CHANCES AT FRONTAL
PASSAGES DURING THE PERIOD.
LINGERING CYCLONIC FLOW ALOFT COULD LEAD TO THE CHANCE OF A SHOWER
SATURDAY...BUT THE TREND BOTH WEATHER AND TEMPERATURE-WISE WILL BE
FOR IMPROVING CONDITIONS AS WE ENTER NEXT WEEK...MUCH MORE
APPROPRIATE FOR MID SPRING THAN WHAT WE HAVE RECENTLY BEEN
EXPERIENCING.
NAEFS SHOWS AN UPPER RIDGE REPLACING OUR TROUGH BY EARLY NEXT
WEEK...WITH ABOVE NORMAL 500MB HEIGHTS AND 850 TEMPS MOVING IN
FOR THE TUESDAY THROUGH THE END OF THE WEEK TIME FRAME.
WITH THE NORTHERN EDGE OF THE SUBTROPICAL RIDGE BEING PROGGED UP
INTO THE LOWER GR LAKES...PATTERN HINTS THAT WE WILL BECOME
VULNERABLE FOR UPSTREAM CONVECTIVE ACTIVITY TO BE FUNNELED INTO
THE LOCAL AREA. THE FIRST CHANCE FOR THIS LOOKS TO BE SOME TIME
LATER MONDAY INTO TUESDAY...BUT HARD TIMING AT THIS RANGE IS
IMPOSSIBLE.
AS THE HIGH PUSHES OFF THE E COAST...RETURN SW FLOW WILL ADVECT
INCREASINGLY WARM AIR INTO PA. GEFS AND ECENS MEAN 8H TEMPS RISE
TO BTWN 10-12C BY EARLY NEXT WEEK...IMPLYING WIDESPREAD 70S FOR
HIGHS.
MID WEEK NEXT WEEK A FRONTAL BOUNDARY LOOKS TO MOVE SOUTH THROUGH
THE STATE THEN STALL NEARBY. SO DESPITE A WARMER PATTERN...MID
WEEK MAY TURNOUT RATHER MOIST AND NOT AS WARM UNDER A BUILDING
RIDGE OVERHEAD.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
SHOWER AND ISOLATED THUNDERSTORM ACTIVITY SLOWLY DIMINISHING FROM
THE NORTH AND EAST...WHILE CONTINUING ACROSS THE SOUTHERN HALF OF
CENTRAL PENNSYLVANIA. THIS IS WELL DEPICTED IN THE HRRR SHORT
RANGE MODEL. FOLLOWING THIS TREND AND THE HRRR GUIDANCE...WOULD
ANTICIPATE MOST SHOWER ACTIVITY TO BE OUT OF THE REGION BY 06Z.
LIGHT WINDS OVERNIGHT...COUPLED WITH THE RAINFALL THAT HAS
AFFECTED MOST TAF LOCATIONS...SHOULD LEAD TO AT LEAST MVFR...AND
AREAS OF IFR...VSBYS AND CIG FORMATION OVERNIGHT.
WITH NO GOOD DRYING PUSH IN THE AM...EXPECT RESTRICTIONS TO SLOWLY
IMPROVE DURING THE MORNING ON FRIDAY...WITH MOST LOCATIONS BACK
TO VFR TO BETWEEN 14Z AND 16Z. KJST MAY BE THE EXCEPTION...WITH
MVFR CONDITIONS LINGERING WELL INTO THE AFTERNOON.
SOME INSTABILITY AGAIN ON FRIDAY AFTERNOON...WITH MORE LIMITED
SHOWER ACTIVITY. HAVE REINTRODUCED VCSH INTO NORTHERN AND WESTERN
TAFS FOR TOMORROW AFTERNOON. HOWEVER...DESPITE THE SCATTERED
SHOWERS...GENERALLY VFR THROUGH THE DAY.
HIGH PRESSURE THEN MOVES IN FROM THE WEST THROUGH MONDAY WITH
MAINLY VFR CONDITIONS. APPROACHING FRONT MAY TRIGGER SOME SHOWERS
IN THE NORTH ON TUESDAY.
OUTLOOK...
SAT-MON...GENERALLY VFR.
TUE...VFR...WITH SHRA IN THE NORTH.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...LA CORTE/GARTNER
AVIATION...JUNG/DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1156 AM EDT WED APR 29 2015
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL MAINTAIN FAIR WEATHER ACROSS
MOST OF CENTRAL PENNSYLVANIA TODAY. AN UPPER LOW DROPPING SOUTH
THROUGH THE NORTHERN GREAT LAKES INTO THE OHIO VALLEY...AND
EVENTUALLY ACROSS THE MID ATLANTIC STATES WILL BRING SHOWERS TO
THE AREA FOR THURSDAY AND FRIDAY. A RELATIVELY COOL END TO THE
WEEK SHOULD GIVE WAY TO A WARMING TREND WITH TEMPERATURES CLIMBING
ABOVE NORMAL INTO THE FIRST WEEK OF MAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
NOON UPDATE...
ALL IS WELL. HRRR DOES MAKE A FEW SPRINKLES IN THE PLACES WITH THE
TALLER CU. WILL HOLD ONTO THE THEROY THAT IF THEY DO TRY TO
PRECIPITATE THAT IT WON/T REACH THE GROUND OR BE SIGNIFICANT
ENOUGH TO HAVE IN THE FCST.
10 AM UPDATE...
TEMPS SKYROCKETING AFTER ABYSMAL LOWS AT THE USUAL COLD SPOTS.
RIDGES WARMED FIRST BUT THE VALLEYS HAVE CAUGHT UP. NUDGED AFTN
TEMPS/MAXES UP SLIGHTLY...BUT COOL TEMPS ALOFT AND CU DEVELOPMENT
SHOULD KEEP IT FROM GETTING TOO WARM. AS STATED PREVIOUSLY...SOME
CU MAY GROW TALL OVER THE NRN MTS AND LAURELS AND MAY PRODUCE
DROPS BIG ENOUGH TO PRECIP BUT THE AIR IS GOING TO BE SO DRY IN
THE 4-5KFT BELOW THE CLOUD BASE THAT IT SHOULD HARDLY REACH THE
GROUND. POPS NIL THRU 00Z.
PREV...
M/CLR SKIES THIS MORNING SHOULD GIVE WAY TO A MIX OF SUN AND
CU/SC BY AFTN. AFTER A COOL START TO THE DAY...TEMPERATURES WILL
REBOUND NICELY TO NEAR AVG FOR THIS TIME OF YEAR WITH HIGHS
RANGING FROM THE LOW 60S ACROSS THE NW ALLEGHENIES TO THE LOW 70S
ACROSS THE LOWER SQV.
THE OPERATIONAL GFS SEEMS TOO BULLISH IN GENERATING LGT QPF AMTS
ALONG AND EAST OF THE ALLEGHENIES BY 00Z THU. THIS IS PROBABLY
MORE INDICATIVE OF SOME BKN CIGS. WILL KEEP FCST DRY THRU THE
EARLY EVE GIVEN VERY WEAK FORCING/LIFT AND MEAGER LOW LEVEL MSTR.
SLIGHTLY BETTER FORCING ARRIVES TONIGHT AS UPPER LOW AND COMPACT
AREA OF 500MB HEIGHT FALLS OVER THE NORTHERN GREAT LAKES DROPS
SWD INTO THE UPPER OH VLY BY 12Z THU. MODEL CONSENSUS APPEARS TO
BE FOCUSING A STRIPE OF QPF ALONG THE ERN PERIPHERY OF THE UPPER
LOW AND HAVE PLACED HIGHEST CHC POPS OVER THE WRN HIGH TERRAIN.
MORE CLOUDS AND A BIT MORE LLVL MSTR SHOULD SUPPORT WARMER
OVERNIGHT LOWS IN THE 40-50F RANGE FROM NORTH TO SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
ALL OPER GUIDANCE TRACKS UPPER LOW SE ACROSS THE OHIO VALLEY
THU...THEN OVR THE S APPALACHIANS THU NIGHT. THIS SCENARIO AND LACK
OF MDL SPREAD SUPPORTS A HIGH CONFIDENCE OF SHOWERS THURSDAY ACROSS
THE SW COUNTIES...WHERE MDLS PLACE ASSOC SFC TROUGH AND PLUME OF
HIGHER PWATS. BASED ON GEFS/SREF OUTPUT...POPS RANGE FROM
CATEGORICAL ACROSS THE LAUREL HIGHLANDS...TO CHC OVR THE EASTERN
COUNTIES. POCKET OF COLD AIR ALOFT SHOULD PROMOTE INCREASING
COVERAGE OF DIURNAL CONVECTION BY THU AFTN. TSRA APPEAR POSSIBLE
IN SPOTS BASED ON MARGINALLY UNSTABLE MDL SOUNDINGS.
MAX TEMPS THU ARE LKLY TO RANGE FROM THE M50S ACROSS THE ALLEGHENY
PLATEAU...WHERE SHOWERS WILL BE MOST NUMEROUS...TO THE U60S ACROSS
THE SUSQ VALLEY...WHERE BREAKS OF SUN WILL BE MOST NUMEROUS.
EXPECT DIMINISHING COVERAGE/INTENSITY OF SHOWERS THU NIGHT AS BLYR
COOLS/STABILIZES. HIGHEST POPS WILL REMAIN ACROSS THE SW
COUNTIES...CLOSEST TO UPPER LOW AND ALONG INVERTED SFC
TROUGH/AXIS OF HIGHEST PWATS. CONSALL 36HR QPF ENDING THU NIGHT
RANGES FROM ALMOST AN INCH OVR SOMERSET CO...TO LESS THAN A TENTH
OF AN INCH EAST OF THE SUSQ RIVER.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
LINGERING COLD TEMPS ALOFT...COMBINED WITH WEAK SHORTWAVES DIVING
INTO BASE OF UPPER TROUGH OVR PA...SHOULD PROMOTE SCT DIURNAL
SHOWERS FRI AND SAT. PLENTY OF CU/SC EXPECTED BENEATH UPPER TROF
WITH HIGHS ONLY IN THE U50S/L60S FRIDAY...THEN BRIGHTER/MILDER WX
LIKELY SAT...AS HEIGHTS BEGIN TO RISE OVR THE NORTHEAST CONUS.
HIGH CONFIDENCE IN A WARMING TREND SUN-TUE...AS ALL MED RANGE
GUIDANCE SHOWS A BUILDING RIDGE ACROSS THE NORTHEAST CONUS. AS
SFC HIGH PUSHES OFF THE E COAST...RETURN SW FLOW WILL ADVECT
INCREASINGLY WARM AIR INTO PA. GEFS AND ECENS MEAN 8H TEMPS RISE
TO BTWN 10-12C BY EARLY NEXT WEEK...IMPLYING WIDESPREAD 70S FOR
HIGHS AND SOME 80S IN THE S VALLEYS. ECENS TRACKS A WEAK NORTHERN
STREAM SHORTWAVE ACROSS ONTARIO/QUEBEC EARLY NEXT WEEK. WILL
INTRODUCE AN INCREASING CHC OF SHRA/TSRA LATE MON/TUE...AS ASSOC
DYING COLD FRONT PUSHES SOUTHWARD FROM NY STATE.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
29/12Z...VFR FLYING WILL DOMINATE MOST OF THE PERIOD WITH M/CLR
SKIES THIS MORNING GIVING WAY TO SCT-BKN CIGS 050-100 BY 00Z.
CANT RULE OUT AN ISOLD LATE-DAY SHOWER OVER THE FAR SW AIRSPACE
ALONG THE RIDGES INVOF JST BUT CONFIDENCE/COVERAGE IS TOO LOW TO
MENTION ATTM. CONFIDENCE IN SHOWER ACTIVITY OVER THE WRN AIRSPACE
IN ZOB SECTOR INCREASES FROM LATE TONIGHT INTO EARLY THURSDAY AS
UPPER LOW DROPS SWD FROM NRN MI INTO THE UPPER OH VLY. THEREFORE
HAVE INCLUDED VCSH AT BFD/JST WITH 2KFT MVFR CIGS AFT 06Z. MDL
DATA LEANS TOWARD IFR AT THESE SITES BY 12Z BUT WAS NOT AS
PESSIMISTIC WITH THIS ISSUANCE. ALSO INTRODUCED SOME MVFR ACROSS
THE CNTRL SITES UNV/AOO AS LLVL MSTR STARTS TO INCREASE AND WINDS
SHIFT TO THE EAST. EXPECT COVERAGE OF SHOWERS TO INCREASE DURING
THE DAY ON THURSDAY WITH A CHC OF THUNDERSTORMS OVER THE SOUTH-
CENTRAL AIRSPACE.
OUTLOOK...
THU-FRI...LOW VFR/MVFR IN SCATTERED RAIN SHOWERS.
SAT-SUN...VFR BUT WITH SCATTERED SHOWERS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DANGELO/STEINBUGL
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1038 PM EDT THU APR 30 2015
.SYNOPSIS...
AS A LOW PRESSURE SYSTEM GRADUALLY MOVES OFFSHORE TONIGHT AND
TOMORROW...DRIER AIR WILL OVERSPREAD THE REGION AND REMAIN IN PLACE
THROUGH EARLY NEXT WEEK. THIS PATTERN WILL BE SLOW TO CHANGE AND
WILL FAVOR MOSTLY DRY AND MILD CONDITIONS THROUGH MID WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1025 PM...FOR THE MOST PART...SHOWERS THAT MOVED OFF THE BLUE
RIDGE EARLIER THIS EVENING HAVE EVOLVED INTO A MASS OF -RA AND
SPRINKLES. IN FACT...OBSERVATION SITES THAT HAVE BEEN REPORTING -RA
ACROSS THE UPSTATE HAVE FOR THE MOST PART FAILED TO MEASURE ANYTHING
MORE THAN A TRACE. THEREFORE...WILL MAINTAIN POPS IN THE LOW CHANCE
RANGE AS THIS AREA PUSHES ACROSS THE SOUTHEAST QUARTER OF THE
FORECAST AREA OVER THE NEXT COUPLE OF HOURS.
UPPER LOW IS CURRENTLY SPINNING OVER EASTERN KENTUCKY. AND WHILE
THERE HAS BEEN A MARKED DECREASE IN CONVECTIVE ACTIVITY ACROSS THE
REGION WITH THE LOSS OF DIURNAL HEATING...SHOWER CHANCES WILL REMAIN
ACROSS THE MTNS...ESP THE TENN BORDER AREAS...WHERE THE LOW LEVEL
FLOW WILL MAINTAIN A WEAK NW/UPSLOPE COMPONENT INTO THE EARLY
MORNING HOURS. TEMPS HAVE ALREADY FALLEN TO THE LOWER/MID 30S ABOVE
ABOUT 5000 FT. IN FACT...THE HIGH PEAKS OF THE BLACK MOUNTAINS
PROBABLY JUST EXPERIENCED A GOOD BURST OF SNOW WITH A WEAKENING BAND
OF CONVECTION THAT MOVED THROUGH THE AREA IN THE PAST FEW MINUTES.
IF ANYTHING...TEMPS WILL PROBABLY SLOWLY COOL THROUGH THE NIGHT IN
THESE HIGH ELEVATION AREAS. THERMO PROFILES ARE ACTUALLY SOMEWHAT
IMPRESSIVE OVER THE NORTHERN MTNS THROUGH THE NIGHT...WITH TEMPS IN
THE MOIST LAYER AS COLD AS -20 C (PER THE NAM). THE UPSHOT
IS LOCATIONS ABOVE 5000 FT SO WILL LIKELY SEE SNOW AS THE PRIMARY P-
TYPE WITH ANY FALLING PRECIP....WITH UP TO AN INCH ACCUMULATION
POSSIBLE...IF NOT LIKELY BY SUNRISE.
AS OF 8 PM...DISORGANIZED AREA OF SHOWERS IS CURRENTLY MOVING OFF
THE HIGH TERRAIN...FOLLOWING THE PREVIOUS BAND/S TREND OF DISPLAYING
A GENERAL WEAKENING/CONTINUED DISORGANIZATION TREND AS IT ENCOUNTERS
THE DOWNSLOPE FLOW OFF THE BLUE RIDGE. POPS WILL THEREFORE BE
MAINTAINED AT LIKELY FOR ANOTHER COUPLE OF HOURS ACROSS THE MTNS...
AND IN THE CHANCE RANGE OUTSIDE THE MTNS...BUT AS LOW LEVEL LAPSE
RATES CONTINUE TO WEAKEN AND WHAT LITTLE BUOYANCY IS AVAILABLE IN
THE ENVIRONMENT WANES...SHOWER CHANCES SHOULD DIMINISH QUITE A BIT
OVER THE NEXT FEW HOURS. GUSTY WINDS WILL REMAIN POSSIBLE WITH SOME
OF THE HEAVIER SHOWER CORES.
AS OF 425 PM...THE FIRST REAL BAND OF SHOWERS ASSOCIATED WITH UPPER
LOW/COLD POOL AND NW FLOW IS PROGRESSING ACROSS THE NC MTNS ATTM.
IT/S NOT ABUNDANTLY CLEAR HOW THIS ACTIVITY WILL RESPOND TO THE
ONGOING DOWNSLOPE FLOW EAST OF THE BLUE RIDGE...SO WHILE POPS HAVE
BEEN INCREASED ACROSS THE NC FOOTHILLS...THEY HAVE BEEN MAINTAINED
IN THE 50-60 PERCENT RANGE. THE PRIMARY ADJUSTMENT TO THE FORECAST
FOR THE REMAINDER OF THE AFTERNOON HAS BEEN TO TEMPER THE THUNDER
MENTION...AS COVERAGE OF DEEPER CONVECTION HAS BEEN ISOLATED AT
BEST THUS FAR...AND IS UNLIKELY TO CHANGE BASED UPON THE RATHER
SHALLOW NATURE OF BUOYANCY PROFILES. WE WILL GENERALLY MENTION
SCATTERED TS ACROSS THE MTNS...AND ISOLATED TO THE EAST. HAVING SAID
THAT...THERE WILL PROBABLY BE QUITE A BIT OF SMALL HAIL THIS
AFTERNOON...AS FREEZING LEVELS ARE BELOW 10 KFT...AND WILL ONLY FALL
MORE AS THE UPPER LOW DRAWS NEARER. SOME GUSTY WINDS WILL ALSO
LIKELY BE SEEN IN LIGHT OF LOW LEVEL LAPSE RATES GREATER THEN 9 C/KM
AND SURFACE DEWPOINT DEPRESSIONS OF AROUND 30 DEGREES.
AS OF 225 PM EDT THU...A CLOSED 500 MB LOW SPINNING OVER THE OHIO
VALLEY WILL MOVE SE ACROSS THE APPALACHIANS TONIGHT. AHEAD OF THIS
SYSTEM...REGIONAL RADAR COVERAGE HAS INCREASED FROM SE KY TO THE SRN
APPALACHIANS. THE LATEST HRRR MODEL RUNS INDICATE SEVERAL ROUNDS OF
SCATTERED CONVECTION CROSSING THE REGION THROUGH THE EVENING
HOURS...IMPACTING LOCATIONS FARTHER S WITH TIME AS A COLD FRONT
PUSHES THROUGH THE AREA. STEEP MID LEVEL LAPSE RATES AROUND 7 DEG
C/KM OR BETTER WILL TRAVERSE THE AREA WITH THE UPPER COLD
POCKET...ESPECIALLY THE INTERSTATE 40 CORRIDOR. IN ADDITION...
FREEZING LEVELS AT OR BELOW 8 KFT WILL CONTRIBUTE TO SMALL HAIL
POTENTIAL WITH ANY BETTER CONVECTIVE ELEMENTS. SHEAR COULD BE A BIT
BETTER IN SRN SECTIONS THIS EVENING...BUT THE WIND DOES NOT APPEAR
TO POSE MUCH THREAT GIVEN THE LIMITED DCAPE AND SHALLOW TOPS. THE
HWO MENTION ADVERTISING SMALL HAIL WITH ANY THUNDER WILL BE
MAINTAINED.
THE COLD CORE LOW WILL PASS OVERHEAD TONIGHT...WITH SOME MEASURE OF
NW FLOW MOISTURE PERSISTING ALONG THE SPINE OF THE SRN APPALACHIANS
INTO FRI MORNING. CONTINUED MTN SHOWERS FROM STEEP LAPSE RATES WILL
BE THE MAIN CONCERN. ALTHOUGH 850 MB TEMPS SHOULD STAY JUST ABOVE
FREEZING...ANY BETTER SHOWER RATES COULD BRING SNOW LEVELS DOWN INTO
THE HIGHER TERRAIN. ANY SNOW ACCUMS SHOULD BE LIGHT AND CONFINED TO
THE RIDGE TOPS...BUT FLURRIES/RIME/GRAUPEL UNDER ANY HEAVIER SHOWERS
CANNOT BE RULED OUT DOWN INTO THE MTN VALLEYS. ALSO CANNOT RULE OUT
ISOLD ADVECTIVE FREEZE ACROSS THE HIGHEST PEAKS OVERNIGHT...BUT NO
WARNING PRODUCT SHOULD BE NEEDED.
THE CLOSED H5 LOW SHOULD MOVE OFF TO THE EAST FRI MORNING...WITH
DEEP LAYER NRLY FLOW IN PLACE ACROSS THE FORECAST AREA. MOISTURE IN
THE NRLY FLOW WILL AFFECT MAINLY THE FOOTHILLS AND PIEDMONT OF WRN
NC FRI. FAIRLY STEEP LAPSE RATES WILL KEEP THE SHOWER POTENTIAL
GOING THROUGH FRI. WILL FEATURE MAXES A BIT BELOW GUIDANCE CONSENSUS
GIVEN THE COLD AIR STRATOCUMULUS SKY COVER.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 200 PM THU...CLOSED UPPER LOW WILL MOVE FURTHER OUT OVER THE
ATLANTIC FRI NIGHT INTO SAT...AND AS HEIGHTS RISE IN ITS WAKE DRY
HIGH PRESSURE WILL FILL IN OVER OUR AREA. DIURNAL ACTIVITY FRI AFTN
DOES NOT APPEAR TO STAND MUCH CHANCE OF LASTING PAST 00Z SAT...SO A
DRY FCST FOR THE FRI NIGHT PERIOD LOOKS FINE. MIN/MAX TEMPS SATURDAY
WILL BE A COUPLE DEGREES BELOW CLIMO. SUBSIDENCE BENEATH THE HIGH
APPEARS TO BE ENOUGH TO STIFLE ANY DIURNAL CONVECTION SATURDAY EVEN
WITH A WEAK UPPER WAVE PASSING OVERHEAD. HOWEVER...BY SUNDAY THE HIGH
WILL HAVE SHIFTED TO THE SOUTHEAST COAST. THE SUBSIDENCE INVERSION IS
A BIT WEAKER AND LAPSE RATES BENEATH IT A BIT BETTER. WE ALSO LOOK TO
WARM A LITTLE MORE...MAXES RETURNING TO ABOUT CLIMO. LOW POPS ARE
SUGGESTED BY THE NAM/GFS INVOF THE BLUE RIDGE WHERE RELATIVELY
SHALLOW CONVECTION COULD FIRE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 100 PM THU...HIGH PRESSURE INITIALLY OVER THE EAST COAST SUNDAY
NIGHT WILL SHIFT EWD INTO A BERMUDA HIGH CONFIGURATION OVER THE
SUBSEQUENT FEW DAYS. UPPER HEIGHTS AND THICKNESSES GRADUALLY INCREASE
OVER THE SOUTHEAST AS A RESULT...SO WE CAN EXPECT TEMPS TO RISE A BIT
ABOVE NORMAL BY MIDWEEK. GULF FLOW WILL ALLOW AN UPWARD TREND IN
AFTERNOON INSTABILITY THRU THE PERIOD...SUGGESTING INCREASING POPS
EACH DAY. HOWEVER THEY REMAIN LOW ENOUGH TO MITIGATE SEVERE THREAT.
OPERATIONAL GFS/EC AS WELL AS MOST GEFS MEMBERS INDICATE AN INVERTED
TROUGH DEVELOPING ON THE SRN BOUNDARY OF THE BERMUDA HIGH BY LATE
TUE...WHICH DRIFTS NWD AND CLOSES OFF BY EARLY THU. THERE IS SOME
SPREAD ON HOW FAR WEST THIS FEATURE TRACKS...THE EC KEEPING IT NEAR
THE ATLANTIC COAST VICE THE GFS AND GEFS CONSENSUS TAKING IT E OF THE
BAHAMAS. IT APPEARS UNLIKELY TO BRING ANY PRECIP TO OUR AREA BASED ON
THE CURRENT PROGS.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AT KCLT...ONE AREA OF SHOWERS IS MOVING EAST OF THE TERMINAL EARLY
THIS EVENING...WHILE ANOTHER IS BEGINNING TO PUSH OFF THE HIGH
TERRAIN TO THE WEST. THIS SECOND AREA OF SHOWERS HAS BEEN APPEARING
INCREASINGLY DISORGANIZED AS IT PUSHES QUICKLY EAST...SO WHILE SHOWER
CHANCES WILL REMAIN THROUGH ABOUT 03Z OR SO...FEEL THE PROBABILITY
IS LOW ENOUGH TO STICK WITH VCSH THROUGH THAT TIME. ANY SHOWERS THAT
DO PASS NEAR THE TERMINAL WILL POSE A CONTINUED RISK FOR BRIEF GUSTY
WINDS...PRIMARILY OUT OF THE N OR NW. OTHERWISE...NW WINDS ARE
EXPECTED TO GRADUALLY DIMINISH THIS EVENING...WHILE MID-LEVEL CLOUDS
AND/OR STRATOCUMULUS SHOULD LINGER IN THE 050-100 RANGE THROUGH MUCH
OF THE OVERNIGHT...IF NOT THROUGH MUCH OF THE PERIOD. SHOWERS MAY
DEVELOP ONCE AGAIN FRI AFTERNOON...BUT COVERAGE IS EXPECTED TO BE
CONSIDERABLY MORE LIMITED THAN TODAY.
ELSEWHERE...SHOWERS WILL REMAIN MOST LIKELY NEAR KAVL THIS
EVENING...WHERE A TEMPO FOR RA/GUSTY WINDS HAS BEEN INTRODUCED
THROUGH 02Z. VCSH SHOULD SUFFICE TO COVER THE SHOWER THREAT AT THE
REMAINING TERMINALS THIS EVENING. GUSTY WINDS WILL BE POSSIBLE WITH
ANY SHOWERS PASSING NEAR THE TERMINALS. OTHERWISE...NW WINDS WILL
PERSIST THROUGH THE OVERNIGHT...GRADUALLY DIMINISHING AT ALL
LOCATIONS EXCEPT KAVL...WHERE 10-15 KT WINDS SHOULD PERSIST. THIS
MOIST UP-VALLEY FLOW COULD RESULT IN BRIEF PERIODS OF MVFR CIGS
AFTER MIDNIGHT. ALL OTHER TERMINALS SHOULD EXPERIENCE VFR CONDITIONS
THROUGH THE PERIOD...WITH PERIODS OF STRATOCU AND/OR MID-LEVEL
CLOUDS IN THE 050-100 RANGE EXPECTED. SHOWERS MAY DEVELOP ONCE AGAIN
FRI AFTERNOON...BUT COVERAGE IS EXPECTED TO BE CONSIDERABLY MORE
LIMITED THAN TODAY.
OUTLOOK...DRY HIGH PRESSURE WILL GRADUALLY BUILD INTO THE AREA LATE
FRIDAY THROUGH THE WEEKEND. RETURN FLOW MOISTURE WILL ONLY SLOWLY
REDEVELOP EARLY NEXT WEEK.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 91% HIGH 98% HIGH 100%
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...JPT
NEAR TERM...HG/JDL
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
807 PM EDT THU APR 30 2015
.SYNOPSIS...
AS A LOW PRESSURE SYSTEM GRADUALLY MOVES OFFSHORE TONIGHT AND
TOMORROW...DRIER AIR WILL OVERSPREAD THE REGION AND REMAIN IN PLACE
THROUGH EARLY NEXT WEEK. THIS PATTERN WILL BE SLOW TO CHANGE AND
WILL FAVOR MOSTLY DRY AND MILD CONDITIONS THROUGH MID WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 8 PM...DISORGANIZED AREA OF SHOWERS IS CURRENTLY MOVING OFF
THE HIGH TERRAIN...FOLLOWING THE PREVIOUS BAND/S TREND OF DISPLAYING
A GENERAL WEAKENING/CONTINUED DISORGANIZATION TREND AS IT ENCOUNTERS
THE DOWNSLOPE FLOW OFF THE BLUE RIDGE. POPS WILL THEREFORE BE
MAINTAINED AT LIKELY FOR ANOTHER COUPLE OF HOURS ACROSS THE MTNS...
AND IN THE CHANCE RANGE OUTSIDE THE MTNS...BUT AS LOW LEVEL LAPSE
RATES CONTINUE TO WEAKEN AND WHAT LITTLE BUOYANCY IS AVAILABLE IN
THE ENVIRONMENT WANES...SHOWER CHANCES SHOULD DIMINISH QUITE A BIT
OVER THE NEXT FEW HOURS. GUSTY WINDS WILL REMAIN POSSIBLE WITH SOME
OF THE HEAVIER SHOWER CORES.
AS OF 425 PM...THE FIRST REAL BAND OF SHOWERS ASSOCIATED WITH UPPER
LOW/COLD POOL AND NW FLOW IS PROGRESSING ACROSS THE NC MTNS ATTM.
IT/S NOT ABUNDANTLY CLEAR HOW THIS ACTIVITY WILL RESPOND TO THE
ONGOING DOWNSLOPE FLOW EAST OF THE BLUE RIDGE...SO WHILE POPS HAVE
BEEN INCREASED ACROSS THE NC FOOTHILLS...THEY HAVE BEEN MAINTAINED
IN THE 50-60 PERCENT RANGE. THE PRIMARY ADJUSTMENT TO THE FORECAST
FOR THE REMAINDER OF THE AFTERNOON HAS BEEN TO TEMPER THE THUNDER
MENTION...AS COVERAGE OF DEEPER CONVECTION HAS BEEN ISOLATED AT
BEST THUS FAR...AND IS UNLIKELY TO CHANGE BASED UPON THE RATHER
SHALLOW NATURE OF BUOYANCY PROFILES. WE WILL GENERALLY MENTION
SCATTERED TS ACROSS THE MTNS...AND ISOLATED TO THE EAST. HAVING SAID
THAT...THERE WILL PROBABLY BE QUITE A BIT OF SMALL HAIL THIS
AFTERNOON...AS FREEZING LEVELS ARE BELOW 10 KFT...AND WILL ONLY FALL
MORE AS THE UPPER LOW DRAWS NEARER. SOME GUSTY WINDS WILL ALSO
LIKELY BE SEEN IN LIGHT OF LOW LEVEL LAPSE RATES GREATER THEN 9 C/KM
AND SURFACE DEWPOINT DEPRESSIONS OF AROUND 30 DEGREES.
AS OF 225 PM EDT THU...A CLOSED 500 MB LOW SPINNING OVER THE OHIO
VALLEY WILL MOVE SE ACROSS THE APPALACHIANS TONIGHT. AHEAD OF THIS
SYSTEM...REGIONAL RADAR COVERAGE HAS INCREASED FROM SE KY TO THE SRN
APPALACHIANS. THE LATEST HRRR MODEL RUNS INDICATE SEVERAL ROUNDS OF
SCATTERED CONVECTION CROSSING THE REGION THROUGH THE EVENING
HOURS...IMPACTING LOCATIONS FARTHER S WITH TIME AS A COLD FRONT
PUSHES THROUGH THE AREA. STEEP MID LEVEL LAPSE RATES AROUND 7 DEG
C/KM OR BETTER WILL TRAVERSE THE AREA WITH THE UPPER COLD
POCKET...ESPECIALLY THE INTERSTATE 40 CORRIDOR. IN ADDITION...
FREEZING LEVELS AT OR BELOW 8 KFT WILL CONTRIBUTE TO SMALL HAIL
POTENTIAL WITH ANY BETTER CONVECTIVE ELEMENTS. SHEAR COULD BE A BIT
BETTER IN SRN SECTIONS THIS EVENING...BUT THE WIND DOES NOT APPEAR
TO POSE MUCH THREAT GIVEN THE LIMITED DCAPE AND SHALLOW TOPS. THE
HWO MENTION ADVERTISING SMALL HAIL WITH ANY THUNDER WILL BE
MAINTAINED.
THE COLD CORE LOW WILL PASS OVERHEAD TONIGHT...WITH SOME MEASURE OF
NW FLOW MOISTURE PERSISTING ALONG THE SPINE OF THE SRN APPALACHIANS
INTO FRI MORNING. CONTINUED MTN SHOWERS FROM STEEP LAPSE RATES WILL
BE THE MAIN CONCERN. ALTHOUGH 850 MB TEMPS SHOULD STAY JUST ABOVE
FREEZING...ANY BETTER SHOWER RATES COULD BRING SNOW LEVELS DOWN INTO
THE HIGHER TERRAIN. ANY SNOW ACCUMS SHOULD BE LIGHT AND CONFINED TO
THE RIDGE TOPS...BUT FLURRIES/RIME/GRAUPEL UNDER ANY HEAVIER SHOWERS
CANNOT BE RULED OUT DOWN INTO THE MTN VALLEYS. ALSO CANNOT RULE OUT
ISOLD ADVECTIVE FREEZE ACROSS THE HIGHEST PEAKS OVERNIGHT...BUT NO
WARNING PRODUCT SHOULD BE NEEDED.
THE CLOSED H5 LOW SHOULD MOVE OFF TO THE EAST FRI MORNING...WITH
DEEP LAYER NRLY FLOW IN PLACE ACROSS THE FORECAST AREA. MOISTURE IN
THE NRLY FLOW WILL AFFECT MAINLY THE FOOTHILLS AND PIEDMONT OF WRN
NC FRI. FAIRLY STEEP LAPSE RATES WILL KEEP THE SHOWER POTENTIAL
GOING THROUGH FRI. WILL FEATURE MAXES A BIT BELOW GUIDANCE CONSENSUS
GIVEN THE COLD AIR STRATOCUMULUS SKY COVER.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 200 PM THU...CLOSED UPPER LOW WILL MOVE FURTHER OUT OVER THE
ATLANTIC FRI NIGHT INTO SAT...AND AS HEIGHTS RISE IN ITS WAKE DRY
HIGH PRESSURE WILL FILL IN OVER OUR AREA. DIURNAL ACTIVITY FRI AFTN
DOES NOT APPEAR TO STAND MUCH CHANCE OF LASTING PAST 00Z SAT...SO A
DRY FCST FOR THE FRI NIGHT PERIOD LOOKS FINE. MIN/MAX TEMPS SATURDAY
WILL BE A COUPLE DEGREES BELOW CLIMO. SUBSIDENCE BENEATH THE HIGH
APPEARS TO BE ENOUGH TO STIFLE ANY DIURNAL CONVECTION SATURDAY EVEN
WITH A WEAK UPPER WAVE PASSING OVERHEAD. HOWEVER...BY SUNDAY THE HIGH
WILL HAVE SHIFTED TO THE SOUTHEAST COAST. THE SUBSIDENCE INVERSION IS
A BIT WEAKER AND LAPSE RATES BENEATH IT A BIT BETTER. WE ALSO LOOK TO
WARM A LITTLE MORE...MAXES RETURNING TO ABOUT CLIMO. LOW POPS ARE
SUGGESTED BY THE NAM/GFS INVOF THE BLUE RIDGE WHERE RELATIVELY
SHALLOW CONVECTION COULD FIRE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 100 PM THU...HIGH PRESSURE INITIALLY OVER THE EAST COAST SUNDAY
NIGHT WILL SHIFT EWD INTO A BERMUDA HIGH CONFIGURATION OVER THE
SUBSEQUENT FEW DAYS. UPPER HEIGHTS AND THICKNESSES GRADUALLY INCREASE
OVER THE SOUTHEAST AS A RESULT...SO WE CAN EXPECT TEMPS TO RISE A BIT
ABOVE NORMAL BY MIDWEEK. GULF FLOW WILL ALLOW AN UPWARD TREND IN
AFTERNOON INSTABILITY THRU THE PERIOD...SUGGESTING INCREASING POPS
EACH DAY. HOWEVER THEY REMAIN LOW ENOUGH TO MITIGATE SEVERE THREAT.
OPERATIONAL GFS/EC AS WELL AS MOST GEFS MEMBERS INDICATE AN INVERTED
TROUGH DEVELOPING ON THE SRN BOUNDARY OF THE BERMUDA HIGH BY LATE
TUE...WHICH DRIFTS NWD AND CLOSES OFF BY EARLY THU. THERE IS SOME
SPREAD ON HOW FAR WEST THIS FEATURE TRACKS...THE EC KEEPING IT NEAR
THE ATLANTIC COAST VICE THE GFS AND GEFS CONSENSUS TAKING IT E OF THE
BAHAMAS. IT APPEARS UNLIKELY TO BRING ANY PRECIP TO OUR AREA BASED ON
THE CURRENT PROGS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AT KCLT...ONE AREA OF SHOWERS IS MOVING EAST OF THE TERMINAL EARLY
THIS EVENING...WHILE ANOTHER IS BEGINNING TO PUSH OFF THE HIGH
TERRAIN TO THE WEST. THIS SECOND AREA OF SHOWERS HAS BEEN APPEARING
INCREASINGLY DISORGANIZED AS IT PUSHES QUICKLY EAST...SO WHILE SHOWER
CHANCES WILL REMAIN THROUGH ABOUT 03Z OR SO...FEEL THE PROBABILITY
IS LOW ENOUGH TO STICK WITH VCSH THROUGH THAT TIME. ANY SHOWERS THAT
DO PASS NEAR THE TERMINAL WILL POSE A CONTINUED RISK FOR BRIEF GUSTY
WINDS...PRIMARILY OUT OF THE N OR NW. OTHERWISE...NW WINDS ARE
EXPECTED TO GRADUALLY DIMINISH THIS EVENING...WHILE MID-LEVEL CLOUDS
AND/OR STRATOCUMULUS SHOULD LINGER IN THE 050-100 RANGE THROUGH MUCH
OF THE OVERNIGHT...IF NOT THROUGH MUCH OF THE PERIOD. SHOWERS MAY
DEVELOP ONCE AGAIN FRI AFTERNOON...BUT COVERAGE IS EXPECTED TO BE
CONSIDERABLY MORE LIMITED THAN TODAY.
ELSEWHERE...SHOWERS WILL REMAIN MOST LIKELY NEAR KAVL THIS
EVENING...WHERE A TEMPO FOR RA/GUSTY WINDS HAS BEEN INTRODUCED
THROUGH 02Z. VCSH SHOULD SUFFICE TO COVER THE SHOWER THREAT AT THE
REMAINING TERMINALS THIS EVENING. GUSTY WINDS WILL BE POSSIBLE WITH
ANY SHOWERS PASSING NEAR THE TERMINALS. OTHERWISE...NW WINDS WILL
PERSIST THROUGH THE OVERNIGHT...GRADUALLY DIMINISHING AT ALL
LOCATIONS EXCEPT KAVL...WHERE 10-15 KT WINDS SHOULD PERSIST. THIS
MOIST UP-VALLEY FLOW COULD RESULT IN BRIEF PERIODS OF MVFR CIGS
AFTER MIDNIGHT. ALL OTHER TERMINALS SHOULD EXPERIENCE VFR CONDITIONS
THROUGH THE PERIOD...WITH PERIODS OF STRATOCU AND/OR MID-LEVEL
CLOUDS IN THE 050-100 RANGE EXPECTED. SHOWERS MAY DEVELOP ONCE AGAIN
FRI AFTERNOON...BUT COVERAGE IS EXPECTED TO BE CONSIDERABLY MORE
LIMITED THAN TODAY.
OUTLOOK...DRY HIGH PRESSURE WILL GRADUALLY BUILD INTO THE AREA LATE
FRIDAY THROUGH THE WEEKEND. RETURN FLOW MOISTURE WILL ONLY SLOWLY
REDEVELOP EARLY NEXT WEEK.
CONFIDENCE TABLE...
00-06Z 06-12Z 12-18Z 18-00Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 94% HIGH 94% HIGH 100%
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...JPT
NEAR TERM...HG/JDL
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...JDL
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
511 PM CDT WED APR 29 2015
.UPDATE...
ALSO INCLUDED ISOLATED THUNDERSTORMS ALONG WITH MENTION OF
SCATTERED SHOWERS ACROSS NORTHEAST AR. LIGHTNING HAS BEEN
DETECTED WITH WEAK SURFACE BASED INSTABILITY.
UPDATE... /ISSUED 456 PM CDT WED APR 29 2015/
SCATTERED SHOWERS ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE ARE
MOVING SOUTH-SOUTHEASTWARD THROUGH NORTHEAST AR. LIGHT RAIN WAS
REPORTED AT CORNING AR WHILE WALNUT RIDGE AR REPORTED A WIND GUST
TO NEAR 40 MPH WITH ONE OF THE SHOWERS. THE LATEST HRRR SHOWS
THESE SHOWERS CONTINUING TO PUSH SOUTH-SOUTHEASTWARD THROUGH
NORTHEAST AR OVER THE NEXT FEW HOURS. WHILE THE HRRR DOES MOVE
THEM INTO MEMPHIS...THE RAP DISSIPATES THE SHOWERS WITH SUNSET
BEFORE THEY REACH MEMPHIS. WILL MONITOR THIS...BUT FOR NOW ONLY
INCLUDED THE SHOWERS ACROSS NORTHEAST AR.
JCL
&&
.DISCUSSION... /ISSUED 332 PM CDT WED APR 29 2015/
CURRENTLY AS OF 3PM... TEMPERATURES ARE IN THE 70S THROUGHOUT THE
MIDSOUTH FOR THE FIRST TIME SINCE SATURDAY BUT STILL ARE A FEW
DEGREES BELOW LATE APRIL NORMALS. SKIES ARE MOSTLY CLEAR
THROUGHOUT THE CWA BUT THAT WILL SOON CHANGE AS AN UPPER LEVEL
SHORTWAVE REVOLVING AROUND A CLOSED LOW NORTH OF THE GREAT LAKES
HAS BEGUN TO MOVE INTO THE REGION INCREASING CLOUDINESS MAINLY IN
THE WESTERN AND SOUTHERN COUNTIES OF THE MIDSOUTH. KNQA RADAR IS
ALREADY DEPICTING LIGHT SHOWERS MOVING INTO THE FAR NORTHEASTERN
CWA... HOWEVER IT IS LIKELY THAT THIS PRECIPITATION IS NOT
REACHING THE GROUND DUE TO REALLY DRY SURFACE AIR IN PLACE.
SHORT TERM...THE AFOREMENTIONED SHORTWAVE WILL CONTINUE TO PUSH
THROUGH THE REGION OVER NIGHT. MODELS AGREE ON VERY LITTLE QPF
WITH THIS DISTURBANCE AND THE MAJORITY OF THE MIDSOUTH WILL STAY DRY.
HOWEVER.. THE LATEST RUN OF THE HRRR DEPICTS SOME VERY ISOLATED
SHOWER ACTIVITY MOVING THROUGH NORTHEASTERN ARKANSAS AND NORTH
WEST MISSISSIPPI THIS EVENING.
ON A BROADER SCALE... AN UPPER LEVEL TROF WILL REMAIN OVER THE
EASTERN UNITED STATES WHILE UPPER RIDGING TAKES PLACE NEAR THE
MISSISSIPPI RIVER VALLEY. THE CLOSED LOW OVER THE GREATS LAKES
WILL PUSH SOUTHWARD THROUGH THE OHIO VALLEY REGION JUST EAST OF
THE MIDSOUTH ON THURSDAY. THE ONLY EFFECT THIS SYSTEM WILL HAVE ON
OUR CWA IS SLIGHTLY RAISED POPS FOR THE COUNTIES IN WEST
TENNESSEE NEAR THE TENNESSEE RIVER... HOWEVER MOST OF THE PRECIP
WILL STAY FAR EAST OF OUR CWA. ABNORMALLY DRY AIR ASSOCIATED WITH
A BROAD SURFACE HIGH WILL BEGIN TO FILTER INTO THE MIDSOUTH
THURSDAY. NORTHWESTERLY FLOW WILL KEEP TEMPERATURES SLIGHTLY
COOLER THAN NORMAL OVER THE NEXT FEW DAYS AS HIGH PRESSURE REMAINS
PARKED OVER THE MIDSOUTH.
LONG TERM...
TEMPERATURES WILL INCREASE TO NEAR NORMAL VALUES BY THE WEEKEND
AND ABOVE AVERAGE BY EARLY NEXT WEEK AS THE SURFACE HIGH SLOWLY SHIFTS
EAST AND FLOW BECOMES MORE SOUTHERLY. THE FORECAST WILL REMAIN DRY
THROUGH MIDWEEK NEXT WEEK. MODELS AGREE ON A MORE DYNAMIC WEATHER
PATTERN SETTING UP BY LATE NEXT WEEK AS A DEEP TROF APPROACHES THE
REGION.
JPM3
&&
.AVIATION...
18Z TAF CYCLE
A WEAK SHORTWAVE TROUGH WILL MOVE ACROSS THE FORECAST AREA THIS
EVENING. NOT MUCH CLOUD COVER OR PRECIPITATION IS EXPECTED WITH
VFR CONDITIONS EXPECTED TO PERSIST THROUGH THE PERIOD. NORTHWEST
WINDS AVERAGING BETWEEN 8-12 KTS WITH A FEW GUSTS WILL BECOME
LIGHT TONIGHT AND INCREASE TO BETWEEN 8-12KTS AFTER 30/15Z.
04
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
456 PM CDT WED APR 29 2015
.UPDATE...
SCATTERED SHOWERS ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE ARE
MOVING SOUTH-SOUTHEASTWARD THROUGH NORTHEAST AR. LIGHT RAIN WAS
REPORTED AT CORNING AR WHILE WALNUT RIDGE AR REPORTED A WIND GUST
TO NEAR 40 MPH WITH ONE OF THE SHOWERS. THE LATEST HRRR SHOWS
THESE SHOWERS CONTINUING TO PUSH SOUTH-SOUTHEASTWARD THROUGH
NORTHEAST AR OVER THE NEXT FEW HOURS. WHILE THE HRRR DOES MOVE
THEM INTO MEMPHIS...THE RAP DISSIPATES THE SHOWERS WITH SUNSET
BEFORE THEY REACH MEMPHIS. WILL MONITOR THIS...BUT FOR NOW ONLY
INCLUDED THE SHOWERS ACROSS NORTHEAST AR.
JCL
&&
.DISCUSSION... /ISSUED 332 PM CDT WED APR 29 2015/
CURRENTLY AS OF 3PM... TEMPERATURES ARE IN THE 70S THROUGHOUT THE
MIDSOUTH FOR THE FIRST TIME SINCE SATURDAY BUT STILL ARE A FEW
DEGREES BELOW LATE APRIL NORMALS. SKIES ARE MOSTLY CLEAR
THROUGHOUT THE CWA BUT THAT WILL SOON CHANGE AS AN UPPER LEVEL
SHORTWAVE REVOLVING AROUND A CLOSED LOW NORTH OF THE GREAT LAKES
HAS BEGUN TO MOVE INTO THE REGION INCREASING CLOUDINESS MAINLY IN
THE WESTERN AND SOUTHERN COUNTIES OF THE MIDSOUTH. KNQA RADAR IS
ALREADY DEPICTING LIGHT SHOWERS MOVING INTO THE FAR NORTHEASTERN
CWA... HOWEVER IT IS LIKELY THAT THIS PRECIPITATION IS NOT
REACHING THE GROUND DUE TO REALLY DRY SURFACE AIR IN PLACE.
SHORT TERM...THE AFOREMENTIONED SHORTWAVE WILL CONTINUE TO PUSH
THROUGH THE REGION OVER NIGHT. MODELS AGREE ON VERY LITTLE QPF
WITH THIS DISTURBANCE AND THE MAJORITY OF THE MIDSOUTH WILL STAY DRY.
HOWEVER.. THE LATEST RUN OF THE HRRR DEPICTS SOME VERY ISOLATED
SHOWER ACTIVITY MOVING THROUGH NORTHEASTERN ARKANSAS AND NORTH
WEST MISSISSIPPI THIS EVENING.
ON A BROADER SCALE... AN UPPER LEVEL TROF WILL REMAIN OVER THE
EASTERN UNITED STATES WHILE UPPER RIDGING TAKES PLACE NEAR THE
MISSISSIPPI RIVER VALLEY. THE CLOSED LOW OVER THE GREATS LAKES
WILL PUSH SOUTHWARD THROUGH THE OHIO VALLEY REGION JUST EAST OF
THE MIDSOUTH ON THURSDAY. THE ONLY EFFECT THIS SYSTEM WILL HAVE ON
OUR CWA IS SLIGHTLY RAISED POPS FOR THE COUNTIES IN WEST
TENNESSEE NEAR THE TENNESSEE RIVER... HOWEVER MOST OF THE PRECIP
WILL STAY FAR EAST OF OUR CWA. ABNORMALLY DRY AIR ASSOCIATED WITH
A BROAD SURFACE HIGH WILL BEGIN TO FILTER INTO THE MIDSOUTH
THURSDAY. NORTHWESTERLY FLOW WILL KEEP TEMPERATURES SLIGHTLY
COOLER THAN NORMAL OVER THE NEXT FEW DAYS AS HIGH PRESSURE REMAINS
PARKED OVER THE MIDSOUTH.
LONG TERM...
TEMPERATURES WILL INCREASE TO NEAR NORMAL VALUES BY THE WEEKEND
AND ABOVE AVERAGE BY EARLY NEXT WEEK AS THE SURFACE HIGH SLOWLY SHIFTS
EAST AND FLOW BECOMES MORE SOUTHERLY. THE FORECAST WILL REMAIN DRY
THROUGH MIDWEEK NEXT WEEK. MODELS AGREE ON A MORE DYNAMIC WEATHER
PATTERN SETTING UP BY LATE NEXT WEEK AS A DEEP TROF APPROACHES THE
REGION.
JPM3
&&
.AVIATION...
18Z TAF CYCLE
A WEAK SHORTWAVE TROUGH WILL MOVE ACROSS THE FORECAST AREA THIS
EVENING. NOT MUCH CLOUD COVER OR PRECIPITATION IS EXPECTED WITH
VFR CONDITIONS EXPECTED TO PERSIST THROUGH THE PERIOD. NORTHWEST
WINDS AVERAGING BETWEEN 8-12 KTS WITH A FEW GUSTS WILL BECOME
LIGHT TONIGHT AND INCREASE TO BETWEEN 8-12KTS AFTER 30/15Z.
04
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
332 PM CDT WED APR 29 2015
.DISCUSSION...
CURRENTLY AS OF 3PM... TEMPERATURES ARE IN THE 70S THROUGHOUT THE
MIDSOUTH FOR THE FIRST TIME SINCE SATURDAY BUT STILL ARE A FEW
DEGREES BELOW LATE APRIL NORMALS. SKIES ARE MOSTLY CLEAR
THROUGHOUT THE CWA BUT THAT WILL SOON CHANGE AS AN UPPER LEVEL
SHORTWAVE REVOLVING AROUND A CLOSED LOW NORTH OF THE GREAT LAKES
HAS BEGUN TO MOVE INTO THE REGION INCREASING CLOUDINESS MAINLY IN
THE WESTERN AND SOUTHERN COUNTIES OF THE MIDSOUTH. KNQA RADAR IS
ALREADY DEPICTING LIGHT SHOWERS MOVING INTO THE FAR NORTHEASTERN
CWA... HOWEVER IT IS LIKELY THAT THIS PRECIPITATION IS NOT
REACHING THE GROUND DUE TO REALLY DRY SURFACE AIR IN PLACE.
SHORT TERM...THE AFOREMENTIONED SHORTWAVE WILL CONTINUE TO PUSH
THROUGH THE REGION OVER NIGHT. MODELS AGREE ON VERY LITTLE QPF
WITH THIS DISTURBANCE AND THE MAJORITY OF THE MIDSOUTH WILL STAY DRY.
HOWEVER.. THE LATEST RUN OF THE HRRR DEPICTS SOME VERY ISOLATED
SHOWER ACTIVITY MOVING THROUGH NORTHEASTERN ARKANSAS AND NORTH
WEST MISSISSIPPI THIS EVENING.
ON A BROADER SCALE... AN UPPER LEVEL TROF WILL REMAIN OVER THE
EASTERN UNITED STATES WHILE UPPER RIDGING TAKES PLACE NEAR THE
MISSISSIPPI RIVER VALLEY. THE CLOSED LOW OVER THE GREATS LAKES
WILL PUSH SOUTHWARD THROUGH THE OHIO VALLEY REGION JUST EAST OF
THE MIDSOUTH ON THURSDAY. THE ONLY EFFECT THIS SYSTEM WILL HAVE ON
OUR CWA IS SLIGHTLY RAISED POPS FOR THE COUNTIES IN WEST
TENNESSEE NEAR THE TENNESSEE RIVER... HOWEVER MOST OF THE PRECIP
WILL STAY FAR EAST OF OUR CWA. ABNORMALLY DRY AIR ASSOCIATED WITH
A BROAD SURFACE HIGH WILL BEGIN TO FILTER INTO THE MIDSOUTH
THURSDAY. NORTHWESTERLY FLOW WILL KEEP TEMPERATURES SLIGHTLY
COOLER THAN NORMAL OVER THE NEXT FEW DAYS AS HIGH PRESSURE REMAINS
PARKED OVER THE MIDSOUTH.
LONG TERM...
TEMPERATURES WILL INCREASE TO NEAR NORMAL VALUES BY THE WEEKEND
AND ABOVE AVERAGE BY EARLY NEXT WEEK AS THE SURFACE HIGH SLOWLY SHIFTS
EAST AND FLOW BECOMES MORE SOUTHERLY. THE FORECAST WILL REMAIN DRY
THROUGH MIDWEEK NEXT WEEK. MODELS AGREE ON A MORE DYNAMIC WEATHER
PATTERN SETTING UP BY LATE NEXT WEEK AS A DEEP TROF APPROACHES THE
REGION.
JPM3
&&
.AVIATION...
18Z TAF CYCLE
A WEAK SHORTWAVE TROUGH WILL MOVE ACROSS THE FORECAST AREA THIS
EVENING. NOT MUCH CLOUD COVER OR PRECIPITATION IS EXPECTED WITH
VFR CONDITIONS EXPECTED TO PERSIST THROUGH THE PERIOD. NORTHWEST
WINDS AVERAGING BETWEEN 8-12 KTS WITH A FEW GUSTS WILL BECOME
LIGHT TONIGHT AND INCREASE TO BETWEEN 8-12KTS AFTER 30/15Z.
04
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1247 PM EDT WED APR 29 2015
.DISCUSSION...UPDATE...SHOWERS NOT MATERIALIZING. STILL QUITE A BIT
OF A DEWPOINT SPREAD ACROSS THE NORTHERN VALLEY AND SWVA. HAVING A
HARD TIME SEEING IT MOISTEN UP ENOUGH TO RAIN OF ANY SIGNIFICANCE.
LATEST HRRR AND RAP CONTINUE TO SHOW LITTLE PRECIP ACROSS THE AREA
FOR THE REST OF THE DAY. UPDATE TO KNOCK BACK POPS AND CLOUDS QUITE
A BIT FOR ALL AREAS WEST OF I-75. AREAS EAST OF I-75 I LOWERED POPS
AS WELL BUT NOT AS MUCH AS WESTERN AREAS. BEST CHANCES FOR LIGHT
PRECIP STILL REMAIN ACROSS THE FAR EASTERN MOUNTAINS AND SWNC WITH
UPDATE. ZONES OUT SOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 67 49 69 46 / 80 30 20 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 65 49 65 44 / 50 20 50 20
OAK RIDGE, TN 66 49 65 44 / 30 20 40 20
TRI CITIES AIRPORT, TN 64 45 61 43 / 50 30 70 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SR
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1011 AM CDT WED APR 29 2015
.UPDATE...A FEW LIGHT SHOWERS HAVE MOVED OVER PARTS OF THE PLATEAU
THIS MORNING...GENERALLY FROM ALTAMONT TO CROSSVILLE. THESE
SHOWERS WERE ON THE FRINGE OF A BATCH OF SHOWERS ASSOCIATED WITH
AN INVERTED SURFACE TROUGH AND MID LEVEL LOW. THESE SYSTEMS WILL
CONTINUE PULLING EAST...SO POPS HAVE BEEN REDUCED AND CONFINED TO
JUST EXTREME EASTERN SECTIONS OF OUR AREA. MEANWHILE...SUNSHINE
WAS PLENTIFUL WEST OF THE PLATEAU WITH MID MORNING TEMPS IN THE
UPPER 50S TO MID 60S.
AS WE GO THROUGH THE DAY...A DRY LOOKING TROUGH AROUND 500 MB WILL
DROP ACROSS TN. THIS WILL CREATE SOME STEEPER LAPSE
RATES...RESULTING IN SCT- BKN CUMULUS CLOUDS. EVEN WITH THE SCT-
BKN CLOUDS...TEMPS ARE ON TRACK TO REACH THE LOWER 70S WEST OF THE
PLATEAU. AFTERNOON HIGHS WILL BE IN THE 60S ON THE PLATEAU WHERE
THE CLOUDS WILL BE THICKER AND MORE PERSISTENT.
13
&&
.PREV DISCUSSION... /ISSUED 550 AM CDT WED APR 29 2015/
UPDATE...
12Z TAFS.
AVIATION...
SFC LOW CROSSING THE GULF...THROUGH NORTH FL AND INTO THE ATLANTIC
WILL HELP KEEP DEEPER MOISTURE SOUTH/EAST AHEAD OF FAIRLY DEEP
UPPER TROUGH. CSV MAY HAVE A FEW SHOWERS LATER TODAY BUT OVERALL
LITTLE IF ANY IMPACT IS EXPECTED TO THE MID-STATE. CSV HOWEVER
COULD GET SOME MVFR LEVEL FOG TOWARD 12Z/THU BUT VFR CONDITIONS
ARE EXPECTED ALL SITES OTHERWISE.
340 AM CDT WED APR 29 2015
.DISCUSSION...
REFLECTIVITY IMAGES CLEARLY SHOW THE UPPER LEVEL SYSTEM CURRENTLY
OVER NW AL. THE MOISTURE IS ON THE SE SIDE OF THE UPPER TROUGH
AXIS WHICH EXTENDS NE FROM THE LOWS CENTER. AT THE SFC...INVERTED
TROUGH STRETCHES FROM THE NRN GULF NNE ACROSS NWRN GA. LOW LEVEL
FORCING IS IN PLACE ALONG THE AXIS. HOWEVER...THE NRN EXTENT OF
THE MOISTURE IS ONLY AS FAR NORTH AS OUR FAR SRN COUNTIES.
LATEST HRRR DATA KEEPS THE MOISTURE ACROSS OUR FAR
SOUTH...EVENTUALLY SPREADING ACROSS THE SOUTHERN AND CENTRAL
PLATEAU. IN KEEPING WITH THAT TREND...WILL CARRY LOW SHOWER CHANCES
FOR THE SOUTH AND EAST ONLY.
TONIGHT...THE SFC TROUGH PUSHES EAST OF OUR AREA. PARTIAL CLOUDINESS
TO REMAIN ALONG WITH COOL TEMPS AGAIN WITH LOWS IN THE 40S.
ON THURSDAY...AN UPPER LEVEL SYSTEM WILL DROP SOUTHWARD ACROSS
EASTERN KY. SOME BACKSIDE MOISTURE DOES APPEAR TO EXIST AND WILL
THEREFORE CARRY A LOW CHANCE OF SHOWERS ONCE AGAIN. ON THIS DAY...I
WILL UNDERCUT THE MAV GUIDANCE RATHER CONSIDERABLY AS CLOUDS...LOW
850 MB TEMPS...AND A FAIRLY STRONG NORTHERLY FLOW ALL PREVAIL.
IN THE EXT FCST...AFOREMENTIONED UPPER LEVEL SYSTEM WILL MOVE
SOUTHEAST AND THEN EAST RATHER QUICKLY. THIS WILL LEAVE A PATTERN
WHEREBY RISING HEIGHTS WILL BE THE RULE. BY EARLY NEXT WEEK...SOME
UPPER LEVEL RIDGING WILL GAIN A STRONGHOLD ON THE WEATHER
SCENARIO. THIS WILL EQUATE TO HIGH TEMPS PUSHING INTO THE 80S WITH
LOW TEMPS IN THE MID TO UPPER 50S. SO...WARM AND DRY DRY WEATHER
IS EXPECTED.
STILL NO ORGANIZED COLD FRONT TO SPEAK OF. UPCOMING PATTERN APPEARS
TO BE PUTTING THE CLAMPS ON ANY UPCOMING SEVERE WX POTENTIAL.
MEANWHILE...MAY IS JUST A FEW DAYS AWAY.
21
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1034 AM EDT WED APR 29 2015
.DISCUSSION...FORECAST MOSTLY ON TRACK THIS MORNING...BUT WITH A FEW
MINOR UPDATES. BUMPED UP MAX TEMPS ACROSS SWVA BY A FEW DEGREES AS
TEMPS HEATED UP MORE QUICKLY THIS MORNING DUE SLOWER ARRIVAL OF
CLOUD COVER. VIS SAT NOW SHOWS CLOUDS FILLING INTO THAT AREA.
DECREASED POPS ACROSS THE PLATEAU FOR LATER THIS AFTERNOON AS HRRR
AND RUC BOTH SHOW BEST CHANCES OF RAIN STAYING WELL EAST OF I-75.
QPF WILL BE VERY LIGHT TODAY NORTH OF I-40...A FEW HUNDREDTHS OF AN
INCH. ALSO DECREASES CLOUD COVER ACROSS MARION...BLEDSOE...AND
SEQUATCHIE DOWN TO PARTLY SUNNY AS CLOUDS SLOWY PULL EAST THROUGH
THE DAY. TWEAKED HOURLY TEMPS TO MATCH UP WITH LATEST OBS. SEVERAL
SPOTS ACROSS THE NORTHERN VALLEY AND SWVA WERE RUNNING 5 TO 8
DEGREES TO LOW IN HOURLY GRID TEMPS DUE TO SLOWER ARRIVAL OF
CLOUDS. NEW ZONES REFLECT TEMP UPDATES...CLOUD COVER...AND POPS FOR
THE AFFECTED AREAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 67 49 69 46 / 80 30 20 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 65 49 65 44 / 60 20 50 20
OAK RIDGE, TN 66 49 65 44 / 50 20 40 20
TRI CITIES AIRPORT, TN 64 45 61 43 / 60 30 70 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SR
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
340 AM CDT WED APR 29 2015
.DISCUSSION...
REFLECTIVITY IMAGES CLEARLY SHOW THE UPPER LEVEL SYSTEM CURRENTLY
OVER NW AL. THE MOISTURE IS ON THE SE SIDE OF THE UPPER TROUGH
AXIS WHICH EXTENDS NE FROM THE LOWS CENTER. AT THE SFC...INVERTED
TROUGH STRETCHES FROM THE NRN GULF NNE ACROSS NWRN GA. LOW LEVEL
FORCING IS IN PLACE ALONG THE AXIS. HOWEVER...THE NRN EXTENT OF
THE MOISTURE IS ONLY AS FAR NORTH AS OUR FAR SRN COUNTIES.
LATEST HRRR DATA KEEPS THE MOISTURE ACROSS OUR FAR
SOUTH...EVENTUALLY SPREADING ACROSS THE SOUTHERN AND CENTRAL
PLATEAU. IN KEEPING WITH THAT TREND...WILL CARRY LOW SHOWER CHANCES
FOR THE SOUTH AND EAST ONLY.
TONIGHT...THE SFC TROUGH PUSHES EAST OF OUR AREA. PARTIAL CLOUDINESS
TO REMAIN ALONG WITH COOL TEMPS AGAIN WITH LOWS IN THE 40S.
ON THURSDAY...AN UPPER LEVEL SYSTEM WILL DROP SOUTHWARD ACROSS
EASTERN KY. SOME BACKSIDE MOISTURE DOES APPEAR TO EXIST AND WILL
THEREFORE CARRY A LOW CHANCE OF SHOWERS ONCE AGAIN. ON THIS DAY...I
WILL UNDERCUT THE MAV GUIDANCE RATHER CONSIDERABLY AS CLOUDS...LOW
850 MB TEMPS...AND A FAIRLY STRONG NORTHERLY FLOW ALL PREVAIL.
IN THE EXT FCST...AFOREMENTIONED UPPER LEVEL SYSTEM WILL MOVE
SOUTHEAST AND THEN EAST RATHER QUICKLY. THIS WILL LEAVE A PATTERN
WHEREBY RISING HEIGHTS WILL BE THE RULE. BY EARLY NEXT WEEK...SOME
UPPER LEVEL RIDGING WILL GAIN A STRONGHOLD ON THE WEATHER
SCENARIO. THIS WILL EQUATE TO HIGH TEMPS PUSHING INTO THE 80S WITH
LOW TEMPS IN THE MID TO UPPER 50S. SO...WARM AND DRY DRY WEATHER
IS EXPECTED.
STILL NO ORGANIZED COLD FRONT TO SPEAK OF. UPCOMING PATTERN APPEARS
TO BE PUTTING THE CLAMPS ON ANY UPCOMING SEVERE WX POTENTIAL.
MEANWHILE...MAY IS JUST A FEW DAYS AWAY.
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 71 48 67 43 / 10 10 20 10
CLARKSVILLE 70 47 66 44 / 10 10 20 05
CROSSVILLE 66 45 64 39 / 30 20 30 10
COLUMBIA 70 48 68 44 / 10 10 20 10
LAWRENCEBURG 69 47 68 45 / 20 10 20 10
WAVERLY 70 47 67 43 / 10 10 20 05
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1101 PM EDT THU APR 30 2015
.SYNOPSIS...
AN UPPER LEVEL LOW WILL HEAD FROM EASTERN KENTUCKY TO NORTH
CAROLINA DURING TONIGHT INTO FRIDAY...WHICH WILL SPARK SCATTERED
SHOWERS AND THUNDERSTORMS. THIS UPPER LEVEL LOW SHOULD DEPART BY
FRIDAY NIGHT...AND HIGH PRESSURE WILL ARRIVE TO BRING WARMER
WEATHER FOR EARLY NEXT WEEK. THE CHANCE OF AFTERNOON SHOWERS AND
THUNDERSTORMS WILL RETURN AS THE WEEK PROGRESSES.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1100 PM EDT THURSDAY...
UPPER LOW CONTINUES TO DRIFT SOUTHEAST AND IN SO
DOING...RAIN SHOWERS HAVE SPREAD BACK INTO THE REGION FROM THE
NORTHWEST...GENERALLY PIVOTING ABOUT THE ROA/BCB REGION. ONE AREA
OF RAIN PERSISTED FOR QUITE SOME TIME ACROSS NORTHERN
PITTSYLVANIA/SOUTHERN CAMPBELL COUNTY WHERE DOPPLER RAINFALL
ESTIMATES 1.5 TO 2.0 INCHES OF RAIN HAS FALLEN TODAY. CURRENT
TREND ON POPS LOOKS GOOD. NOT SEEING ANY LIGHTNING ANY MORE AND
WITH THE LOSS OF DAYTIME HEATING WOULD NOT EXPECT ANY FROM THIS
POINT FORWARD. PREVIOUS GRIDS CAPTURED THE ENDING TIME OF THAT AS
WELL. EARLIER ADJUSTMENT DOWNWARD OF TEMPERATURES HAS BEEN ON
TRACK AND OTHER THAN A MINOR ADJUSTMENT DOWNWARD ACROSS THE
PIEDMONT...TEMPERATURES APPEAR TO BE ON TRACK FOR THE REMAINDER OF
THE NIGHT. SYNOPTIC SITUATION NOT PARTICULARLY SUPPORTIVE OF
FOG...SO WILL NOT ADD ANY IN THE GRIDS AT THIS TIME.
AS OF 730 PM EDT THURSDAY...
SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO
ROTATE AROUND THE UPPER LOW. MAIN AREA AT THIS MOMENT HAS SHIFTED
OVER INTO THE NC PIEDMONT OUT OF OUR CWA...BUT A NEW AREA IS
POISED TO MOVE INTO FAR SW VA. HRRR INDICATES ACTIVITY UP IN
PA/NORTHERN VA/MD WILL SHIFT SOUTH OVERNIGHT ACROSS THE CWA FROM
NORTH-SOUTH AS THE UPPER LOW MOVES ESE TOWARD THE COAST. THE
PRECIPITATION RESULTED IN SOME SIGNIFICANT EVAPORATIVE COOLING IN
THE WEST WITH TEMPERATURES DOWN IN THE 40S IN THE WESTERN
COUNTIES. THUS...HAD TO LOWER TEMPERATURES IN THOSE AREAS A GOOD
10 DEGREES. HOWEVER...ADDITIONAL COOLING OVERNIGHT SHOULD BE
LIMITED AS TEMPERATURES NEAR DEWPOINT. ONLY ADJUSTED OVERNIGHT
MINS DOWN A COUPLE OF DEGREES. DID NOT ADJUST POPS MUCH AS HRRR
SHOWS ACTIVITY CONTINUING MUCH OF THE NIGHT. WILL RE-EVALUATE POPS
WITH LATER UPDATES.
AS OF 405 PM EDT THURSDAY...
AN UPPER LEVEL LOW CONTINUES TO HEAD CLOSER TO THE WESTERN PORTION
OF THE CWA. CURRENTLY...SCATTERED SHOWERS AND THUNDERSTORMS ARE
LINING UP OVER THE PIEDMONT. WEAK FLOW ALOFT IS CAUSING
CONSIDERABLY SLOW STORM MOTIONS. DUE TO EARLIER SUNSHINE AND
STEEPENING LAPSE RATES AS COOLER AIR ARRIVES ALOFT...SOME SMALL
HAIL IS LIKELY IN THE STRONGER STORMS. WE HAVE ALREADY RECEIVED
SEVERAL REPORTS OF PEA TO DIME SIZE HAIL THIS AFTERNOON...BUT
NOTHING HAS REACHED SEVERE LIMITS. MEANWHILE...MORE SHOWERS AND
THUNDERSTORMS ARE SPREADING OVER THE WESTERN MOUNTAINS. THIS
ACTIVITY IS MUCH LESS ORGANIZED...BUT IT COULD PICK UP A LITTLE
DURING THE NEXT SEVERAL HOURS.
BY TONIGHT...THE UPPER LEVEL LOW WILL BE DIRECTLY OVERHEAD...WHICH
WILL KEEP THE SHOWER ACTIVITY ONGOING THROUGHOUT THE NIGHT.
HOWEVER...THUNDER CHANCES SHOULD DIMINISH AFTER MIDNIGHT. CLOUD
COVER WILL BE WIDESPREAD...WHICH MEANS LOW TEMPERATURES COULD DROP
NO FURTHER THAN THE 40S. ALTHOUGH MOISTURE WILL GRADUALLY SUBSIDE
DURING FRIDAY...THE SHOWERS WILL LINGER INTO FRIDAY AFTERNOON. THE
ACTIVITY SHOULD SPREAD EASTWARD INTO THE PIEDMONT...AND EVENTUALLY
CLEAR THE CWA BY SUNSET. HIGHS ON FRIDAY MAY BE A LITTLE TRICKY IF
THE CLOUD COVER TRIES TO SCATTER SOONER THAN ANTICIPATED BY THE
MODELS. ONLY MID 50S TO LOWER 60S ARE EXPECTED FOR HIGHS...WHICH
ARE A COUPLE DEGREES BELOW MOS GUIDANCE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 215 PM EDT THURSDAY...
SATURDAY NIGHT...SOME LINGERING SHOWERS WILL STILL BE POSSIBLE
DURING THE EARLY EVENING HOURS FROM EARLIER CONVECTION SATURDAY
AFTERNOON. THE GREATEST CONCENTRATION WILL BE ACROSS THE
MOUNTAINS...ALONG AND NORTH OF ROUTE 460.
ON SATURDAY...ONE LAST SHORTWAVE TROUGH WILL SPIRAL AROUND THE WEST
SIDE OF THE DEPARTING UPPER LOW. ANTICIPATED ISOLATED TO SCATTERED
SHOWERS TO DEVELOP DURING THE PEAK HEATING OF THE AFTERNOON ACROSS
THE EASTERN HALF OF THE REGION. INSTABILITY AT THIS TIME APPEARS TOO
WEAK TO INCLUDE MENTION OF ISOLATED STORMS.
SATURDAY NIGHT INTO SUNDAY...AN UPPER RIDGE WILL START TO BUILD JUST
WEST OF THE REGION. THIS WILL BE THE START OF THE TREND OF MILDER
CONDITIONS AND A MUCH LOWER PROBABILITY OF PRECIPITATION. AT
BEST...ISOLATED SHOWERS MAY OCCUR SUNDAY AFTERNOON ACROSS THE
NORTHERN MOUNTAINS OF NORTH CAROLINA.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 1230 PM EDT THURSDAY...
UPPER LEVEL RIDGING WILL CONTINUE ACROSS THE REGION DURING THE
MAJORITY OF THIS PORTION OF THE FORECAST. AN UPPER LOW MOVING
EASTWARD THROUGH CANADA WILL WEAKEN THE RIDGE A BIT WEDNESDAY INTO
THURSDAY...SHIFTING A BACKDOOR FRONT TOWARD OUR REGION. WHILE ALL OF
THIS IS OCCURRING...AN ELONGATED TROUGH/UPPER LOW WILL BE DEVELOPING
ACROSS THE CENTRAL PART OF THE COUNTRY. WE ARE ANTICIPATING
PROGRESSIVELY MILDER TEMPERATURES EACH DAY WITHIN THIS REGIME. FOR
PRECIPITATION...THE CENTER OF THE SURFACE HIGH WILL JUST BE SHIFTING
EAST OF THE AREA ON MONDAY. THIS WILL LIMIT THE DEGREE OF RETURN
MOISTURE INTO THE AREA TO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
IT IS HERE WHERE ISOLATED SHOWERS WILL BE FORECAST FOR THE
AFTERNOON. FROM TUESDAY INTO THURSDAY...COVERAGE OF SHOWERS AND
STORMS WILL BE INCREASING...ESPECIALLY IN THE WEST...WITH THE
APPROACH...AND POTENTIAL ARRIVAL...OF THE BACKDOOR FRONT.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS OF 759 PM EDT THURSDAY...
AN UPPER LEVEL LOW WILL MOVE SOUTHWARD ACROSS THE REGION TONIGHT
INTO FRIDAY. SCATTERED MVFR/IFR RAIN SHOWERS AND ISOLATED
THUNDERSTORMS WILL CONTINUE TO ROTATE AROUND THE3 UPPER LOW.
BELIEVE THE THREAT FOR THUNDERSTORMS WILL DIMINISH DURING THE
NEXT COUPLE OF HOURS WITH THE LOSS OF SOLAR HEATING. BUT THE COLD
POOL ALOFT WILL SUPPORT SHOWERS CONTINUING OVERNIGHT. CEILINGS
WILL LOWER OVERNIGHT ESPECIALLY IN LOCATIONS WHICH RECEIVED
RAINFALL. PATCHES OF LOW CLOUDS AND FOG WILL DEVELOP IN SPOTS
WHERE OVER AN INCH OF RAIN OCCURRED THURSDAY.
VISIBILITIES SHOULD IMPROVE TO VFR BY FRIDAY MORNING...BUT
CEILINGS WILL TAKE LONGER TO IMPROVE...AND MAY STILL BE MVFR BY
18Z FRIDAY. WINDS SHOULD BE A BIT STRONGER AND FROM THE
NORTH...WHILE THE COVERAGE OF RAIN SHOWERS SLOWLY WANES. THUNDER
CHANCES ARE SIGNIFICANTLY LESS AS WELL.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
CONDITIONS SHOULD IMPROVE TO VFR BY FRIDAY EVENING...AS THE UPPER
LEVEL LOW DEPARTS OFFSHORE. A SIGNIFICANT WEATHER PATTERN CHANCE
WILL TAKE PLACE THIS WEEKEND...AS HIGH PRESSURE BUILDS OVERHEAD.
OTHER THAN POSSIBLE EARLY MORNING MVFR FOG IN THE USUAL RIVER
VALLEY LOCATIONS...VFR CONDITIONS SHOULD PERSIST THROUGH THIS
WEEKEND INTO EARLY NEXT WEEK. A WARMER AND MOISTER AIR MASS COULD
ALLOW FOR A FEW SHOWERS TO POP UP DURING MONDAY AFTERNOON. A
GREATER CHANCE OF SHOWERS...WITH A FEW ISOLATED THUNDERSTORMS IN
THE WESTERN MOUNTAINS...ARE POSSIBLE FOR TUESDAY.
&&
.EQUIPMENT...
AS OF 150 PM EDT THURSDAY...
THE UPPER AIR TRACKING SYSTEM HAS MALFUNCTIONED...SO THERE WILL
BE NO SOUNDINGS UNTIL THIS ISSUE IS RESOLVED. A PART IS ON
ORDER...AND TECHNICIANS WILL BE REPLACING THIS PART ONCE IT
ARRIVES EITHER LATER TODAY OR TOMORROW.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PW
NEAR TERM...PW
SHORT TERM...DS/RAB
LONG TERM...DS
AVIATION...KK/PW
EQUIPMENT...PW
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
759 PM EDT THU APR 30 2015
.SYNOPSIS...
AN UPPER LEVEL LOW WILL HEAD FROM EASTERN KENTUCKY TO NORTH
CAROLINA DURING TONIGHT INTO FRIDAY...WHICH WILL SPARK SCATTERED
SHOWERS AND THUNDERSTORMS. THIS UPPER LEVEL LOW SHOULD DEPART BY
FRIDAY NIGHT...AND HIGH PRESSURE WILL ARRIVE TO BRING WARMER
WEATHER FOR EARLY NEXT WEEK. THE CHANCE OF AFTERNOON SHOWERS AND
THUNDERSTORMS WILL RETURN AS THE WEEK PROGRESSES.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 730 PM EDT THURSDAY...
SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO
ROTATE AROUND THE UPPER LOW. MAIN AREA AT THIS MOMENT HAS SHIFTED
OVER INTO THE NC PIEDMONT OUT OF OUR CWA...BUT A NEW AREA IS
POISED TO MOVE INTO FAR SW VA. HRRR INDICATES ACTIVITY UP IN
PA/NORTHERN VA/MD WILL SHIFT SOUTH OVERNIGHT ACROSS THE CWA FROM
NORTH-SOUTH AS THE UPPER LOW MOVES ESE TOWARD THE COAST. THE
PRECIPITATION RESULTED IN SOME SIGNIFICANT EVAPORATIVE COOLING IN
THE WEST WITH TEMPERATURES DOWN IN THE 40S IN THE WESTERN
COUNTIES. THUS...HAD TO LOWER TEMPERATURES IN THOSE AREAS A GOOD
10 DEGREES. HOWEVER...ADDITIONAL COOLING OVERNIGHT SHOULD BE
LIMITED AS TEMPERATURES NEAR DEWPOINT. ONLY ADJUSTED OVERNIGHT
MINS DOWN A COUPLE OF DEGREES. DID NOT ADJUST POPS MUCH AS HRRR
SHOWS ACTIVITY CONTINUING MUCH OF THE NIGHT. WILL RE-EVALUATE POPS
WITH LATER UPDATES.
AS OF 405 PM EDT THURSDAY...
AN UPPER LEVEL LOW CONTINUES TO HEAD CLOSER TO THE WESTERN PORTION
OF THE CWA. CURRENTLY...SCATTERED SHOWERS AND THUNDERSTORMS ARE
LINING UP OVER THE PIEDMONT. WEAK FLOW ALOFT IS CAUSING
CONSIDERABLY SLOW STORM MOTIONS. DUE TO EARLIER SUNSHINE AND
STEEPENING LAPSE RATES AS COOLER AIR ARRIVES ALOFT...SOME SMALL
HAIL IS LIKELY IN THE STRONGER STORMS. WE HAVE ALREADY RECEIVED
SEVERAL REPORTS OF PEA TO DIME SIZE HAIL THIS AFTERNOON...BUT
NOTHING HAS REACHED SEVERE LIMITS. MEANWHILE...MORE SHOWERS AND
THUNDERSTORMS ARE SPREADING OVER THE WESTERN MOUNTAINS. THIS
ACTIVITY IS MUCH LESS ORGANIZED...BUT IT COULD PICK UP A LITTLE
DURING THE NEXT SEVERAL HOURS.
BY TONIGHT...THE UPPER LEVEL LOW WILL BE DIRECTLY OVERHEAD...WHICH
WILL KEEP THE SHOWER ACTIVITY ONGOING THROUGHOUT THE NIGHT.
HOWEVER...THUNDER CHANCES SHOULD DIMINISH AFTER MIDNIGHT. CLOUD
COVER WILL BE WIDESPREAD...WHICH MEANS LOW TEMPERATURES COULD DROP
NO FURTHER THAN THE 40S. ALTHOUGH MOISTURE WILL GRADUALLY SUBSIDE
DURING FRIDAY...THE SHOWERS WILL LINGER INTO FRIDAY AFTERNOON. THE
ACTIVITY SHOULD SPREAD EASTWARD INTO THE PIEDMONT...AND EVENTUALLY
CLEAR THE CWA BY SUNSET. HIGHS ON FRIDAY MAY BE A LITTLE TRICKY IF
THE CLOUD COVER TRIES TO SCATTER SOONER THAN ANTICIPATED BY THE
MODELS. ONLY MID 50S TO LOWER 60S ARE EXPECTED FOR HIGHS...WHICH
ARE A COUPLE DEGREES BELOW MOS GUIDANCE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 215 PM EDT THURSDAY...
SATURDAY NIGHT...SOME LINGERING SHOWERS WILL STILL BE POSSIBLE
DURING THE EARLY EVENING HOURS FROM EARLIER CONVECTION SATURDAY
AFTERNOON. THE GREATEST CONCENTRATION WILL BE ACROSS THE
MOUNTAINS...ALONG AND NORTH OF ROUTE 460.
ON SATURDAY...ONE LAST SHORTWAVE TROUGH WILL SPIRAL AROUND THE WEST
SIDE OF THE DEPARTING UPPER LOW. ANTICIPATED ISOLATED TO SCATTERED
SHOWERS TO DEVELOP DURING THE PEAK HEATING OF THE AFTERNOON ACROSS
THE EASTERN HALF OF THE REGION. INSTABILITY AT THIS TIME APPEARS TOO
WEAK TO INCLUDE MENTION OF ISOLATED STORMS.
SATURDAY NIGHT INTO SUNDAY...AN UPPER RIDGE WILL START TO BUILD JUST
WEST OF THE REGION. THIS WILL BE THE START OF THE TREND OF MILDER
CONDITIONS AND A MUCH LOWER PROBABILITY OF PRECIPITATION. AT
BEST...ISOLATED SHOWERS MAY OCCUR SUNDAY AFTERNOON ACROSS THE
NORTHERN MOUNTAINS OF NORTH CAROLINA.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 1230 PM EDT THURSDAY...
UPPER LEVEL RIDGING WILL CONTINUE ACROSS THE REGION DURING THE
MAJORITY OF THIS PORTION OF THE FORECAST. AN UPPER LOW MOVING
EASTWARD THROUGH CANADA WILL WEAKEN THE RIDGE A BIT WEDNESDAY INTO
THURSDAY...SHIFTING A BACKDOOR FRONT TOWARD OUR REGION. WHILE ALL OF
THIS IS OCCURRING...AN ELONGATED TROUGH/UPPER LOW WILL BE DEVELOPING
ACROSS THE CENTRAL PART OF THE COUNTRY. WE ARE ANTICIPATING
PROGRESSIVELY MILDER TEMPERATURES EACH DAY WITHIN THIS REGIME. FOR
PRECIPITATION...THE CENTER OF THE SURFACE HIGH WILL JUST BE SHIFTING
EAST OF THE AREA ON MONDAY. THIS WILL LIMIT THE DEGREE OF RETURN
MOISTURE INTO THE AREA TO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
IT IS HERE WHERE ISOLATED SHOWERS WILL BE FORECAST FOR THE
AFTERNOON. FROM TUESDAY INTO THURSDAY...COVERAGE OF SHOWERS AND
STORMS WILL BE INCREASING...ESPECIALLY IN THE WEST...WITH THE
APPROACH...AND POTENTIAL ARRIVAL...OF THE BACKDOOR FRONT.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 759 PM EDT THURSDAY...
AN UPPER LEVEL LOW WILL MOVE SOUTHWARD ACROSS THE REGION TONIGHT
INTO FRIDAY. SCATTERED MVFR/IFR RAIN SHOWERS AND ISOLATED
THUNDERSTORMS WILL CONTINUE TO ROTATE AROUND THE3 UPPER LOW.
BELIEVE THE THREAT FOR THUNDERSTORMS WILL DIMINSH DURING THE NEXT
COUPLE OF HOURS WITH THE LOSS OF SOLAR HEATING. BUT THE COLD POOL
ALOFT WILL SUPPORT SHOWERS CONTINUING OVERNIGHT. CEILINGS WILL
LOWER OVERNIGHT ESPECIALLY IN LOCATIONS WHICH RECEIVED RAINFALL.
PATCHES OF LOW CLOUDS AND FOG WILL DEVELOP IN SPOTS WHERE OVER AN
INCH OF RAIN OCCURRED THURSDAY.
VISIBILITIES SHOULD IMPROVE TO VFR BY FRIDAY MORNING...BUT
CEILINGS WILL TAKE LONGER TO IMPROVE...AND MAY STILL BE MVFR BY
18Z FRIDAY. WINDS SHOULD BE A BIT STRONGER AND FROM THE
NORTH...WHILE THE COVERAGE OF RAIN SHOWERS SLOWLY WANES. THUNDER
CHANCES ARE SIGNIFICANTLY LESS AS WELL.
MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
CONDITIONS SHOULD IMPROVE TO VFR BY FRIDAY EVENING...AS THE UPPER
LEVEL LOW DEPARTS OFFSHORE. A SIGNIFICANT WEATHER PATTERN CHANCE
WILL TAKE PLACE THIS WEEKEND...AS HIGH PRESSURE BUILDS OVERHEAD.
OTHER THAN POSSIBLE EARLY MORNING MVFR FOG IN THE USUAL RIVER
VALLEY LOCATIONS...VFR CONDITIONS SHOULD PERSIST THROUGH THIS
WEEKEND INTO EARLY NEXT WEEK. A WARMER AND MOISTER AIR MASS COULD
ALLOW FOR A FEW SHOWERS TO POP UP DURING MONDAY AFTERNOON. A
GREATER CHANCE OF SHOWERS...WITH A FEW ISOLATED THUNDERSTORMS IN
THE WESTERN MOUNTAINS...ARE POSSIBLE FOR TUESDAY.
&&
.EQUIPMENT...
AS OF 150 PM EDT THURSDAY...
THE UPPER AIR TRACKING SYSTEM HAS MALFUNCTIONED...SO THERE WILL
BE NO SOUNDINGS UNTIL THIS ISSUE IS RESOLVED. A PART IS ON
ORDER...AND TECHNICIANS WILL BE REPLACING THIS PART ONCE IT
ARRIVES EITHER LATER TODAY OR TOMORROW.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PW
NEAR TERM...PW
SHORT TERM...DS/RAB
LONG TERM...DS
AVIATION...KK/PW
EQUIPMENT...PW
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
739 PM EDT THU APR 30 2015
.SYNOPSIS...
AN UPPER LEVEL LOW WILL HEAD FROM EASTERN KENTUCKY TO NORTH
CAROLINA DURING TONIGHT INTO FRIDAY...WHICH WILL SPARK SCATTERED
SHOWERS AND THUNDERSTORMS. THIS UPPER LEVEL LOW SHOULD DEPART BY
FRIDAY NIGHT...AND HIGH PRESSURE WILL ARRIVE TO BRING WARMER
WEATHER FOR EARLY NEXT WEEK. THE CHANCE OF AFTERNOON SHOWERS AND
THUNDERSTORMS WILL RETURN AS THE WEEK PROGRESSES.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 730 PM EDT THURSDAY...
SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO
ROTATE AROUND THE UPPER LOW. MAIN AREA AT THIS MOMENT HAS SHIFTED
OVER INTO THE NC PIEDMONT OUT OF OUR CWA...BUT A NEW AREA IS
POISED TO MOVE INTO FAR SW VA. HRRR INDICATES ACTIVITY UP IN
PA/NORTHERN VA/MD WILL SHIFT SOUTH OVERNIGHT ACROSS THE CWA FROM
NORTH-SOUTH AS THE UPPER LOW MOVES ESE TOWARD THE COAST. THE
PRECIPITATION RESULTED IN SOME SIGNIFICANT EVAPORATIVE COOLING IN
THE WEST WITH TEMPERATURES DOWN IN THE 40S IN THE WESTERN
COUNTIES. THUS...HAD TO LOWER TEMPERATURES IN THOSE AREAS A GOOD
10 DEGREES. HOWEVER...ADDITIONAL COOLING OVERNIGHT SHOULD BE
LIMITED AS TEMPERATURES NEAR DEWPOINT. ONLY ADJUSTED OVERNIGHT
MINS DOWN A COUPLE OF DEGREES. DID NOT ADJUST POPS MUCH AS HRRR
SHOWS ACTIVITY CONTINUING MUCH OF THE NIGHT. WILL RE-EVALUATE POPS
WITH LATER UPDATES.
AS OF 405 PM EDT THURSDAY...
AN UPPER LEVEL LOW CONTINUES TO HEAD CLOSER TO THE WESTERN PORTION
OF THE CWA. CURRENTLY...SCATTERED SHOWERS AND THUNDERSTORMS ARE
LINING UP OVER THE PIEDMONT. WEAK FLOW ALOFT IS CAUSING
CONSIDERABLY SLOW STORM MOTIONS. DUE TO EARLIER SUNSHINE AND
STEEPENING LAPSE RATES AS COOLER AIR ARRIVES ALOFT...SOME SMALL
HAIL IS LIKELY IN THE STRONGER STORMS. WE HAVE ALREADY RECEIVED
SEVERAL REPORTS OF PEA TO DIME SIZE HAIL THIS AFTERNOON...BUT
NOTHING HAS REACHED SEVERE LIMITS. MEANWHILE...MORE SHOWERS AND
THUNDERSTORMS ARE SPREADING OVER THE WESTERN MOUNTAINS. THIS
ACTIVITY IS MUCH LESS ORGANIZED...BUT IT COULD PICK UP A LITTLE
DURING THE NEXT SEVERAL HOURS.
BY TONIGHT...THE UPPER LEVEL LOW WILL BE DIRECTLY OVERHEAD...WHICH
WILL KEEP THE SHOWER ACTIVITY ONGOING THROUGHOUT THE NIGHT.
HOWEVER...THUNDER CHANCES SHOULD DIMINISH AFTER MIDNIGHT. CLOUD
COVER WILL BE WIDESPREAD...WHICH MEANS LOW TEMPERATURES COULD DROP
NO FURTHER THAN THE 40S. ALTHOUGH MOISTURE WILL GRADUALLY SUBSIDE
DURING FRIDAY...THE SHOWERS WILL LINGER INTO FRIDAY AFTERNOON. THE
ACTIVITY SHOULD SPREAD EASTWARD INTO THE PIEDMONT...AND EVENTUALLY
CLEAR THE CWA BY SUNSET. HIGHS ON FRIDAY MAY BE A LITTLE TRICKY IF
THE CLOUD COVER TRIES TO SCATTER SOONER THAN ANTICIPATED BY THE
MODELS. ONLY MID 50S TO LOWER 60S ARE EXPECTED FOR HIGHS...WHICH
ARE A COUPLE DEGREES BELOW MOS GUIDANCE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 215 PM EDT THURSDAY...
SATURDAY NIGHT...SOME LINGERING SHOWERS WILL STILL BE POSSIBLE
DURING THE EARLY EVENING HOURS FROM EARLIER CONVECTION SATURDAY
AFTERNOON. THE GREATEST CONCENTRATION WILL BE ACROSS THE
MOUNTAINS...ALONG AND NORTH OF ROUTE 460.
ON SATURDAY...ONE LAST SHORTWAVE TROUGH WILL SPIRAL AROUND THE WEST
SIDE OF THE DEPARTING UPPER LOW. ANTICIPATED ISOLATED TO SCATTERED
SHOWERS TO DEVELOP DURING THE PEAK HEATING OF THE AFTERNOON ACROSS
THE EASTERN HALF OF THE REGION. INSTABILITY AT THIS TIME APPEARS TOO
WEAK TO INCLUDE MENTION OF ISOLATED STORMS.
SATURDAY NIGHT INTO SUNDAY...AN UPPER RIDGE WILL START TO BUILD JUST
WEST OF THE REGION. THIS WILL BE THE START OF THE TREND OF MILDER
CONDITIONS AND A MUCH LOWER PROBABILITY OF PRECIPITATION. AT
BEST...ISOLATED SHOWERS MAY OCCUR SUNDAY AFTERNOON ACROSS THE
NORTHERN MOUNTAINS OF NORTH CAROLINA.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 1230 PM EDT THURSDAY...
UPPER LEVEL RIDGING WILL CONTINUE ACROSS THE REGION DURING THE
MAJORITY OF THIS PORTION OF THE FORECAST. AN UPPER LOW MOVING
EASTWARD THROUGH CANADA WILL WEAKEN THE RIDGE A BIT WEDNESDAY INTO
THURSDAY...SHIFTING A BACKDOOR FRONT TOWARD OUR REGION. WHILE ALL OF
THIS IS OCCURRING...AN ELONGATED TROUGH/UPPER LOW WILL BE DEVELOPING
ACROSS THE CENTRAL PART OF THE COUNTRY. WE ARE ANTICIPATING
PROGRESSIVELY MILDER TEMPERATURES EACH DAY WITHIN THIS REGIME. FOR
PRECIPITATION...THE CENTER OF THE SURFACE HIGH WILL JUST BE SHIFTING
EAST OF THE AREA ON MONDAY. THIS WILL LIMIT THE DEGREE OF RETURN
MOISTURE INTO THE AREA TO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
IT IS HERE WHERE ISOLATED SHOWERS WILL BE FORECAST FOR THE
AFTERNOON. FROM TUESDAY INTO THURSDAY...COVERAGE OF SHOWERS AND
STORMS WILL BE INCREASING...ESPECIALLY IN THE WEST...WITH THE
APPROACH...AND POTENTIAL ARRIVAL...OF THE BACKDOOR FRONT.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 150 PM EDT THURSDAY...
SHOWERS AND THUNDERSTORMS ARE STARTING TO INCREASE IN COVERAGE
ACROSS THE TERMINAL AREA...BUT NONE ARE DIRECTLY AFFECTING THE TAF
SITES AT THIS HOUR. THUS...A MENTION OF VCSH SHOULD SUFFICE FOR
THIS AFTERNOON...BUT MAY NEED A FEW AMENDS LATER IF ANY ACTIVITY
BECOMES MORE ORGANIZED AND FOCUSED. THE BEST CHANCES APPEAR TO BE
ALONG THE BLUE RIDGE MOUNTAINS...WHERE SURFACE CONVERGENCE AND
OROGRAPHICAL LIFT ARE HELPING TO FOCUS THE ACTION. DUE TO THUNDER
BEING WIDELY SCATTERED AND LOW CONFIDENCE IN PINPOINTING EXACT
LOCATIONS AT THIS TIME...NO MENTION OF TS WAS INCLUDED IN THIS
UPDATE...BUT IT IS NOT OUT OF THE REALM OF POSSIBILITY.
AN UPPER LEVEL LOW DIVING SOUTHWARD TOWARD NORTH CAROLINA IS
RESPONSIBLE FOR THE ACTIVITY THIS AFTERNOON...WHICH SHOULD
CONTINUE THROUGH TONIGHT. CEILINGS AND VISIBILITIES WILL
DETERIORATE TO MVFR UNDER THE HEAVIER SHOWERS THIS EVENING...AND
LATER THROUGHOUT THE ENTIRE TERMINAL AREA TONIGHT. MODEL GUIDANCE
IS SHOWING IFR CEILINGS POSSIBLE FOR BCB/BLF/LWB/LYH...WHICH IS
NOTED IN THE TAFS FOR THESE SITES BY EARLY FRIDAY MORNING.
CONFIDENCE IS SIGNIFICANTLY LOWER FOR IFR TO APPEAR FOR ROA/DAN.
VISIBILITIES SHOULD IMPROVE TO VFR BY FRIDAY MORNING...BUT
CEILINGS WILL TAKE LONGER TO IMPROVE...AND MAY STILL BE MVFR BY
18Z FRIDAY. WINDS SHOULD BE A BIT STRONGER AND FROM THE
NORTH...WHILE THE COVERAGE OF RAIN SHOWERS SLOWLY WANES. THUNDER
CHANCES ARE SIGNIFICANTLY LESS AS WELL.
CONDITIONS SHOULD IMPROVE TO VFR BY FRIDAY EVENING...AS THE UPPER
LEVEL LOW DEPARTS OFFSHORE. A SIGNIFICANT WEATHER PATTERN CHANCE
WILL TAKE PLACE THIS WEEKEND...AS HIGH PRESSURE BUILDS OVERHEAD.
OTHER THAN POSSIBLE EARLY MORNING MVFR FOG IN THE USUAL RIVER
VALLEY LOCATIONS...VFR CONDITIONS SHOULD PERSIST THROUGH THIS
WEEKEND INTO EARLY NEXT WEEK. A WARMER AND MOISTER AIR MASS COULD
ALLOW FOR A FEW SHOWERS TO POP UP DURING MONDAY AFTERNOON. A
GREATER CHANCE OF SHOWERS...WITH A FEW ISOLATED THUNDERSTORMS IN
THE WESTERN MOUNTAINS...ARE POSSIBLE FOR TUESDAY.
&&
.EQUIPMENT...
AS OF 150 PM EDT THURSDAY...
THE UPPER AIR TRACKING SYSTEM HAS MALFUNCTIONED...SO THERE WILL
BE NO SOUNDINGS UNTIL THIS ISSUE IS RESOLVED. A PART IS ON
ORDER...AND TECHNICIANS WILL BE REPLACING THIS PART ONCE IT
ARRIVES EITHER LATER TODAY OR TOMORROW.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PW
NEAR TERM...PW
SHORT TERM...DS/RAB
LONG TERM...DS
AVIATION...KK/PW
EQUIPMENT...PW
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
135 PM EDT WED APR 29 2015
.SYNOPSIS...
LOW PRESSURE DEVELOPING OVER THE SOUTHEASTERN UNITED STATES WILL
SLOWLY MOVE OFF THE MIDDLE ATLANTIC COAST BY FRIDAY. THIS WILL
BRING A CHANCE OF RAIN TO THE REGION THROUGH THE END OF THE
WORKWEEK. HIGH PRESSURE WILL THEN MOVE IN FROM THE SOUTHWEST...
BRINGING WARMER AND GENERALLY DRY CONDITIONS TO THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 PM EDT WEDNESDAY...
FOR THIS AFTERNOON...TWO NOTABLE ADJUSTMENTS HAVE BEEN MADE TO
THE FORECAST. FIRST...00Z/8PM GUIDANCE HAD BEEN HINTING AT SOME
INSTABILITY ACROSS THE WESTERN PORTIONS OF THE AREA THIS AFTERNOON
ALONG AND INVERTED TROUGH. WITH THE 12Z/8AM GUIDANCE SHOWING EQUAL
OR GREATER AMOUNTS OF INSTABILITY OVER A GREATER GUIDANCE
MEMBERS...HAVE DECIDED TO INCLUDE ISOLATED THUNDERSTORMS FROM THE
NORTHERN MOUNTAINS OF NORTH CAROLINA...NORTH INTO SOUTHEAST WEST
VIRGINIA THIS AFTERNOON. THIS MATCHES WELL WITH THE LATEST DAY
ONE OUTLOOK FROM THE STORM PREDICTION CENTER WITH GENERAL THUNDER
OVER A SIMILAR REGION. SECOND...CLOUD COVER CONTINUES TO
OVERSPREAD THE REGION FROM SOUTH TO NORTHER AS EARLIER
ANTICIPATED. HOWEVER...TEMPERATURES HAVE MANAGED TO INCREASE A
LITTLE BIT MORE QUICKLY THAN PREVIOUSLY ADVERTISED. HAVE ADJUSTED
THE FORECAST HIGH TEMPERATURES UPWARD A FEW DEGREES AT MOST
LOCATIONS IN RESPONSE TO THIS.
AS OF 955 AM EDT WEDNESDAY...
HAVE CONTINUED THE TREND OF BACKING OFF ON POPS TODAY BASED UPON
THE LATEST HRRR AND RNK WRK ARW GUIDANCE...ESPECIALLY EAST OF THE
CREST OF THE BLUE RIDGE. ACROSS THE MOUNTAINS...HAVE SLOWED THE
ONSET OF SHOWERS DEVELOPING ACROSS THE NORTHERN MOUNTAINS OF NORTH
CAROLINA...AND SPREADING NORTH INTO SOUTHEAST WEST VIRGINIA.
COVERAGE IS STILL EXPECTED TO BE THE GREATEST ACROSS THE FAR
SOUTHWEST PARTS OF THE REGION THIS AFTERNOON. HAVE ALSO DECREASED
THE EXTENT OF THE COVERAGE HEAD INTO...AND CONTINUING THROUGH MUCH
OF THE OVERNIGHT PERIOD. NO OTHER MAJOR CHANGES AT THIS TIME.
AS OF 734 AM EDT WEDNESDAY...
CONTINUE TO SEE SLOWER PROGRESS NORTH INTO THE DRIER AIR WE HAVE
IN PLACE...SO BACKED OFF POPS AGAIN AND LOWERED SKY COVER AND
TEMPS EARLY ON BASED ON OBS. STILL LOOKS LIKE MAINLY WRN CWA AFTER
MIDDAY TO SEE SOME SHOWERS/LIGHT RAIN...STILL
PATCHY/SCATTERED...WITH MORE COVERAGE TOWARD THE NC MTNS.
PREVIOUS DISCUSSION FROM 4 AM....
OVERALL THE FORECAST EXPECTED TO BE A LITTLE DRIER TODAY THAN
WHAT IS APPEARED 24 TO 60 HRS AGO. THIS MORNING...THE UPPER
LOW/TROUGH WAS SITUATED OVER THE LOWER MS VALLEY WITH WEAK FLOW
ALOFT ACROSS OUR AREA. MAIN AREA OF RAINFALL AND LIFT WAS WELL
SOUTH OF US FROM NRN ALABAMA INTO SC.
THE MODELS IN AGREEMENT WHICH SPELLS AN INCREASE IN MID AND HIGH
CLOUDS THIS MORNING...THEN MORE LOWER CLOUDS INTO THE SRN CWA BY LATE
MORNING WITH LIGHT RAIN/RAIN SHOWERS DEVELOPING WITH INCREASING
LIFT...THOUGH THE LOW LVL FLOW IS NOT THAT STRONG.
THE MODELS TAKE THE SFC LOW FROM THE FL PANHANDLE THIS MORNING TO
WELL OFF THE SC COAST BY THIS EVENING...WHILE NRN STREAM ENERGY
DIVES SE INTO THE GREAT LAKES FORMING A WEAK SFC LOW OVER THE MID
ATLANTIC. NOT TOO IMPRESSED WITH RAIN THREAT TODAY BUT THE PATTERN
FAVORS THE BLUE RIDGE AND WEST HAVING A BETTER CHANCE THAN THE
NORTHEAST AND EAST OVER THE PIEDMONT. HAVE BACKED OFF POPS THIS
MORNING AND SITUATE HIGH CHANCE TO LOW LIKELY POPS FROM THE NEW
RIVER VALLEY SOUTH AND WEST TO SRN WV/NW NC. QPF WITH THIS WILL BE
UNDER A QUARTER INCH...WITH MOST ONLY SEEING A FEW HUNDREDTHS.
FOR TEMPS...THINK ENOUGH SUNSHINE IN THE VA PIEDMONT THROUGH HIGH
CLOUDS ALLOWS READINGS TO CLIMB TO LOWER 70S THIS AFTERNOON WHILE IT
WILL STAY COOLER OVER THE SOUTHERN BLUE RIDGE WHERE SHOWERS/RAIN
MOVE IN QUICKER. THIS AREA WILL ONLY EXPERIENCE HIGHS IN THE 50S.
ELSEWHERE IT WILL BE IN THE 60S.
TONIGHT...THE SRN SHORTWAVE DIVE SOUTHEAST INTO THE GULF COAST
STATES...SOME BACKING FLOW AND DIGGING NRN STREAM SHORTWAVE TO ALLOW
SOME UPPER FORCING OVER THE MTNS. CONFIDENCE NOT HIGH THAT RAINFALL
WILL BE NUMEROUS...SO KEPT POPS 50 PERCENT OR LESS TIL DAWN..WHEN
THE UPPER TROUGH HEADS CLOSER WITH BETTER LIFT.
LOW TEMPS WILL BE IN THE 40S. WEAK SFC WINDS AND INCREASED SFC
MOISTURE EVEN WITH CLOUDS WILL LEAD TO A THREAT OF FOG AREAWIDE...SO
ADDED THAT TO THE FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM EDT WEDNESDAY...
THE MAIN WEATHER FEATURE TO BE CONCERNED WITH ON THURSDAY WILL BE AN
UPPER LEVEL LOW PRESSURE SYSTEM DESCENDING FROM THE GREAT LAKES
DURING THE MORNING...REACHING EASTERN KENTUCKY DURING THE EVENING.
THE COLD AIR ALOFT ASSOCIATED WITH THIS SYSTEM WILL SUPPORT
SCATTERED SHOWERS ACROSS THE AREA...WITH A FEW THUNDERSTORMS
DEVELOPING DURING THE AFTERNOON AND EVENING. THIS SYSTEM WILL DRIVE
VERY STEEP LAPSE RATES INTO OUR AREA...MEANING THAT WHILE AFTERNOON
HIGH TEMPERATURES WILL RANGE FROM THE LOW 60S ACROSS THE MOUNTAINS
TO THE UPPER 60S FURTHER EAST...TEMPERATURES WILL COOL RAPIDLY WITH
HEIGHT...FALLING BELOW FREEZING SOME FOUR TO SEVEN THOUSAND FEET
ABOVE THE SURFACE. WITH FREEZING HEIGHTS SO LOW...BELIEVE THAT EVEN
SHOWER ACTIVITY WILL BE CAPABLE OF PRODUCING SMALL HAIL...WHILE ONE
OR TWO OF THE STRONGER STORMS MAY PRODUCE QUARTER-SIZE HAIL. IN
ADDITION...WITH DRY AIR IN THE LOW LEVELS...MAY ALSO SEE A COUPLE OF
THE STRONGER CELLS PRODUCE LOCALLY GUSTY DOWNDRAFTS. WITH LOSS OF
DAYTIME HEATING AROUND SUNSET...SHOWER ACTIVITY IS EXPECTED TO
WEAKEN...BUT EXPECT A FEW SHOWERS TO LINGER THROUGH THE OVERNIGHT.
ON FRIDAY...THE UPPER LEVEL LOW WILL SHIFT QUICKLY FROM THE CENTRAL
APPALACHIANS DURING THE MORNING...TO OFF THE COAST DURING THE
AFTERNOON. EXPECT TO SEE SCATTERED SHOWERS REDEVELOP DURING THE
MORNING...MORE SO ACROSS THE PIEDMONT...AS DAYTIME HEATING
INCREASES. HOWEVER SHOWER ACTIVITY WILL DIMINISH DURING THE
AFTERNOON AS THE COLD AIR ALOFT EXITS...WITH DOWNSLOPE NORTHWESTERLY
FLOW TAKING OVER AND ADDING STABILITY TO THE ATMOSPHERE. THE PASSAGE
OF THE UPPER LOW WILL MAKE FOR A COOLER DAY...WITH AFTERNOON HIGHS
RANGING FROM THE UPPER 50S WEST TO THE LOW 60S EAST.
HIGH PRESSURE IN THE LOW LEVELS WILL BECOME ESTABLISHED FROM THE
MISSISSIPPI RIVER THROUGH THE APPALACHIANS ON SATURDAY...WHILE UPPER
LEVEL FLOW BEGINS A TRANSITION TO A MORE ZONAL PATTERN. THE
INCREASED SUNSHINE...ALBEIT WITH SCATTERED AFTERNOON CLOUDS...WILL
COMBINE WITH THE DOWNSLOPE WINDFLOW TO PUSH AFTERNOON HIGHS INTO THE
MID 60S ACROSS THE MOUNTAINS...AND INTO THE LOW 70S ACROSS THE
PIEDMONT.
OVERNIGHT LOWS WILL FALL INTO THE 40S EACH NIGHT. BELIEVE CLOUD
COVER ON THURSDAY AND FRIDAY NIGHTS WILL KEEP FROST FORMATION
ISOLATED AT BEST...IF ANY AT ALL.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 320 PM EDT TUESDAY...
THE ENSEMBLE MEANS ARE FAIRLY HARMONIOUS, DEPICTING GENTLY
UNDULATING ZONAL FLOW ACROSS THE CONTIGUOUS UNITED STATES INTO EARLY
NEXT WEEK. THIS WILL BE A CHANGE FROM THE HIGH AMPLITUDE FLOW WE
HAVE ENDURED THIS MONTH SUGGESTING THE COOL AIR WILL FINALLY MAKE
A RETREAT. AS HEIGHTS/THICKNESSES RISE LOOK FOR TEMPERATURES TO
RETURN CLOSER TO NORMAL THIS WEEKEND AND FAVORING ABOVE NORMAL
READINGS...+4 TO +8 DEGREES...FOR THE FIRST FULL WEEK OF MAY.
THREAT FOR RAINFALL NEXT WEEK LOOKS MINIMAL FOR THE MID
ATLANTIC...WITH FOCUS FOR SHOWERS/STORMS CONFINED MAINLY TO THE MID
SECTION OF THE COUNTRY. IT WILL NOT BE ENTIRELY CLEAR HOWEVER...AS
WE STILL ANTICIPATE PERIODS OF DEBRIS CLOUDINESS TO MOVE QUICKLY
EAST WITHIN THE FAST ZONAL FLOW FROM THE STORMS MID CONUS.
WITH THE MODELS IN RELATIVE AGREEMENT...ANOTHER FEATURE OF INTEREST
SPARKED SOME CURIOSITY. BOTH THE GFS AND ECMWF SHOWED THE
DEVELOPMENT OF A CYCLONE...TROPICAL?...JUST OFF THE EAST COAST OF
FLORIDA BY THE MIDDLE OF NEXT WEEK. WHETHER THIS COMES TO FRUITION
OR NOT...IT DID CAUSE ME TO TAKE PAUSE AND LOOK AT THE CALENDAR. T-
MINUS 33 DAYS AND COUNTING TO THE OFFICIAL START OF HURRICANE
SEASON.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 130 PM EDT WEDNESDAY...
FORECAST CONFIDENCE IS MODERATE TO HIGH THIS AFTERNOON THROUGH
EARLY THURSDAY EVENING.
CLOUD COVER IS INCREASING ACROSS THE AREA FROM SOUTH TO
NORTH...HOWEVER VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER
OF THE AFTERNOON. ISOLATED TO SCATTERED SHOWERS ARE EXPECTED TO
DEVELOP THIS AFTERNOON GENERALLY ALONG AND WEST OF A KTNB-KBCB-
KLWB LINE...WITH ISOLATED THUNDERSTORMS A POTENTIAL.
OVERNIGHT...MAINLY VFR CIGS ARE ANTICIPATED...BUT PATCHY MVFR
LIGHT FOG IS EXPECTED TO DEVELOP...ESPECIALLY IN THE VALLEYS AND
WHERE PRECIPITATION OCCURS THIS AFTERNOON INTO THE EVENING.
APPROACH OF AN UPPER LOW FROM THE NORTHWEST ON THURSDAY WILL BRING
INCREASING LAPSE RATES ALOFT...ALONG WITH THE POTENTIAL FOR
GREATER COVERAGE OF SHOWERS AND STORMS AS COMPARED TO TODAY. ANY
MVFR VSBYS SHOULD IMPROVE TO VFR BY 13-14Z/9-10AM.
THURSDAY AFTERNOON AND EARLY EVENING...ANTICIPATE SCATTERED
SHOWERS AND STORMS TO CONTINUE ALONG WITH PRIMARILY VFR
CONDITIONS.
FORECAST CONFIDENCE IS MODERATE THURSDAY NIGHT INTO FRIDAY.
UPPER LOW CROSSES THE AREA THURSDAY NIGHT INTO FRIDAY. EXPECT
ADDITIONAL SHOWER AND STORMS...ALONG WITH FLIGHT CATEGORIES
TRENDING TO MVFR FOR VSBYS AND MVFR/IFR FOR CIGS THURSDAY NIGHT.
VSBYS ARE EXPECTED TO IMPROVE QUICKLY TO VFR ON FRIDAY...WITH CIGS
GRADUALLY INCREASING TO VFR DURING THE DAY.
FORECAST CONFIDENCE IS MODERATE TO HIGH FRIDAY NIGHT THROUGH
MONDAY.
THE AREA WILL TRANSITION FROM A NORTHWEST FLOW PATTERN TO MORE A
ZONAL FLOW PATTERN WITH SURFACE HIGH PRESSURE BUILDING OVERNIGHT.
OTHER THAN SOME LATE NIGHT EARLY MORNING VALLEY/RIVER
FOG...CONDITIONS FOR THE MOST PART ARE EXPECTED TO BE VFR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS/WP
NEAR TERM...DS/WP
SHORT TERM...NF
LONG TERM...PM
AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1250 PM EDT WED APR 29 2015
.SYNOPSIS...
LOW PRESSURE DEVELOPING OVER THE SOUTHEASTERN UNITED STATES WILL
SLOWLY MOVE OFF THE MIDDLE ATLANTIC COAST BY FRIDAY. THIS WILL
BRING A CHANCE OF RAIN TO THE REGION THROUGH THE END OF THE
WORKWEEK. HIGH PRESSURE WILL THEN MOVE IN FROM THE SOUTHWEST...
BRINGING WARMER AND GENERALLY DRY CONDITIONS TO THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 PM EDT WEDNESDAY...
FOR THIS AFTERNOON...TWO NOTABLE ADJUSTMENTS HAVE BEEN MADE TO
THE FORECAST. FIRST...00Z/8PM GUIDANCE HAD BEEN HINTING AT SOME
INSTABILITY ACROSS THE WESTERN PORTIONS OF THE AREA THIS AFTERNOON
ALONG AND INVERTED TROUGH. WITH THE 12Z/8AM GUIDANCE SHOWING EQUAL
OR GREATER AMOUNTS OF INSTABILITY OVER A GREATER GUIDANCE
MEMBERS...HAVE DECIDED TO INCLUDE ISOLATED THUNDERSTORMS FROM THE
NORTHERN MOUNTAINS OF NORTH CAROLINA...NORTH INTO SOUTHEAST WEST
VIRGINIA THIS AFTERNOON. THIS MATCHES WELL WITH THE LATEST DAY
ONE OUTLOOK FROM THE STORM PREDICTION CENTER WITH GENERAL THUNDER
OVER A SIMILAR REGION. SECOND...CLOUD COVER CONTINUES TO
OVERSPREAD THE REGION FROM SOUTH TO NORTHER AS EARLIER
ANTICIPATED. HOWEVER...TEMPERATURES HAVE MANAGED TO INCREASE A
LITTLE BIT MORE QUICKLY THAN PREVIOUSLY ADVERTISED. HAVE ADJUSTED
THE FORECAST HIGH TEMPERATURES UPWARD A FEW DEGREES AT MOST
LOCATIONS IN RESPONSE TO THIS.
AS OF 955 AM EDT WEDNESDAY...
HAVE CONTINUED THE TREND OF BACKING OFF ON POPS TODAY BASED UPON
THE LATEST HRRR AND RNK WRK ARW GUIDANCE...ESPECIALLY EAST OF THE
CREST OF THE BLUE RIDGE. ACROSS THE MOUNTAINS...HAVE SLOWED THE
ONSET OF SHOWERS DEVELOPING ACROSS THE NORTHERN MOUNTAINS OF NORTH
CAROLINA...AND SPREADING NORTH INTO SOUTHEAST WEST VIRGINIA.
COVERAGE IS STILL EXPECTED TO BE THE GREATEST ACROSS THE FAR
SOUTHWEST PARTS OF THE REGION THIS AFTERNOON. HAVE ALSO DECREASED
THE EXTENT OF THE COVERAGE HEAD INTO...AND CONTINUING THROUGH MUCH
OF THE OVERNIGHT PERIOD. NO OTHER MAJOR CHANGES AT THIS TIME.
AS OF 734 AM EDT WEDNESDAY...
CONTINUE TO SEE SLOWER PROGRESS NORTH INTO THE DRIER AIR WE HAVE
IN PLACE...SO BACKED OFF POPS AGAIN AND LOWERED SKY COVER AND
TEMPS EARLY ON BASED ON OBS. STILL LOOKS LIKE MAINLY WRN CWA AFTER
MIDDAY TO SEE SOME SHOWERS/LIGHT RAIN...STILL
PATCHY/SCATTERED...WITH MORE COVERAGE TOWARD THE NC MTNS.
PREVIOUS DISCUSSION FROM 4 AM....
OVERALL THE FORECAST EXPECTED TO BE A LITTLE DRIER TODAY THAN
WHAT IS APPEARED 24 TO 60 HRS AGO. THIS MORNING...THE UPPER
LOW/TROUGH WAS SITUATED OVER THE LOWER MS VALLEY WITH WEAK FLOW
ALOFT ACROSS OUR AREA. MAIN AREA OF RAINFALL AND LIFT WAS WELL
SOUTH OF US FROM NRN ALABAMA INTO SC.
THE MODELS IN AGREEMENT WHICH SPELLS AN INCREASE IN MID AND HIGH
CLOUDS THIS MORNING...THEN MORE LOWER CLOUDS INTO THE SRN CWA BY LATE
MORNING WITH LIGHT RAIN/RAIN SHOWERS DEVELOPING WITH INCREASING
LIFT...THOUGH THE LOW LVL FLOW IS NOT THAT STRONG.
THE MODELS TAKE THE SFC LOW FROM THE FL PANHANDLE THIS MORNING TO
WELL OFF THE SC COAST BY THIS EVENING...WHILE NRN STREAM ENERGY
DIVES SE INTO THE GREAT LAKES FORMING A WEAK SFC LOW OVER THE MID
ATLANTIC. NOT TOO IMPRESSED WITH RAIN THREAT TODAY BUT THE PATTERN
FAVORS THE BLUE RIDGE AND WEST HAVING A BETTER CHANCE THAN THE
NORTHEAST AND EAST OVER THE PIEDMONT. HAVE BACKED OFF POPS THIS
MORNING AND SITUATE HIGH CHANCE TO LOW LIKELY POPS FROM THE NEW
RIVER VALLEY SOUTH AND WEST TO SRN WV/NW NC. QPF WITH THIS WILL BE
UNDER A QUARTER INCH...WITH MOST ONLY SEEING A FEW HUNDREDTHS.
FOR TEMPS...THINK ENOUGH SUNSHINE IN THE VA PIEDMONT THROUGH HIGH
CLOUDS ALLOWS READINGS TO CLIMB TO LOWER 70S THIS AFTERNOON WHILE IT
WILL STAY COOLER OVER THE SOUTHERN BLUE RIDGE WHERE SHOWERS/RAIN
MOVE IN QUICKER. THIS AREA WILL ONLY EXPERIENCE HIGHS IN THE 50S.
ELSEWHERE IT WILL BE IN THE 60S.
TONIGHT...THE SRN SHORTWAVE DIVE SOUTHEAST INTO THE GULF COAST
STATES...SOME BACKING FLOW AND DIGGING NRN STREAM SHORTWAVE TO ALLOW
SOME UPPER FORCING OVER THE MTNS. CONFIDENCE NOT HIGH THAT RAINFALL
WILL BE NUMEROUS...SO KEPT POPS 50 PERCENT OR LESS TIL DAWN..WHEN
THE UPPER TROUGH HEADS CLOSER WITH BETTER LIFT.
LOW TEMPS WILL BE IN THE 40S. WEAK SFC WINDS AND INCREASED SFC
MOISTURE EVEN WITH CLOUDS WILL LEAD TO A THREAT OF FOG AREAWIDE...SO
ADDED THAT TO THE FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM EDT WEDNESDAY...
THE MAIN WEATHER FEATURE TO BE CONCERNED WITH ON THURSDAY WILL BE AN
UPPER LEVEL LOW PRESSURE SYSTEM DESCENDING FROM THE GREAT LAKES
DURING THE MORNING...REACHING EASTERN KENTUCKY DURING THE EVENING.
THE COLD AIR ALOFT ASSOCIATED WITH THIS SYSTEM WILL SUPPORT
SCATTERED SHOWERS ACROSS THE AREA...WITH A FEW THUNDERSTORMS
DEVELOPING DURING THE AFTERNOON AND EVENING. THIS SYSTEM WILL DRIVE
VERY STEEP LAPSE RATES INTO OUR AREA...MEANING THAT WHILE AFTERNOON
HIGH TEMPERATURES WILL RANGE FROM THE LOW 60S ACROSS THE MOUNTAINS
TO THE UPPER 60S FURTHER EAST...TEMPERATURES WILL COOL RAPIDLY WITH
HEIGHT...FALLING BELOW FREEZING SOME FOUR TO SEVEN THOUSAND FEET
ABOVE THE SURFACE. WITH FREEZING HEIGHTS SO LOW...BELIEVE THAT EVEN
SHOWER ACTIVITY WILL BE CAPABLE OF PRODUCING SMALL HAIL...WHILE ONE
OR TWO OF THE STRONGER STORMS MAY PRODUCE QUARTER-SIZE HAIL. IN
ADDITION...WITH DRY AIR IN THE LOW LEVELS...MAY ALSO SEE A COUPLE OF
THE STRONGER CELLS PRODUCE LOCALLY GUSTY DOWNDRAFTS. WITH LOSS OF
DAYTIME HEATING AROUND SUNSET...SHOWER ACTIVITY IS EXPECTED TO
WEAKEN...BUT EXPECT A FEW SHOWERS TO LINGER THROUGH THE OVERNIGHT.
ON FRIDAY...THE UPPER LEVEL LOW WILL SHIFT QUICKLY FROM THE CENTRAL
APPALACHIANS DURING THE MORNING...TO OFF THE COAST DURING THE
AFTERNOON. EXPECT TO SEE SCATTERED SHOWERS REDEVELOP DURING THE
MORNING...MORE SO ACROSS THE PIEDMONT...AS DAYTIME HEATING
INCREASES. HOWEVER SHOWER ACTIVITY WILL DIMINISH DURING THE
AFTERNOON AS THE COLD AIR ALOFT EXITS...WITH DOWNSLOPE NORTHWESTERLY
FLOW TAKING OVER AND ADDING STABILITY TO THE ATMOSPHERE. THE PASSAGE
OF THE UPPER LOW WILL MAKE FOR A COOLER DAY...WITH AFTERNOON HIGHS
RANGING FROM THE UPPER 50S WEST TO THE LOW 60S EAST.
HIGH PRESSURE IN THE LOW LEVELS WILL BECOME ESTABLISHED FROM THE
MISSISSIPPI RIVER THROUGH THE APPALACHIANS ON SATURDAY...WHILE UPPER
LEVEL FLOW BEGINS A TRANSITION TO A MORE ZONAL PATTERN. THE
INCREASED SUNSHINE...ALBEIT WITH SCATTERED AFTERNOON CLOUDS...WILL
COMBINE WITH THE DOWNSLOPE WINDFLOW TO PUSH AFTERNOON HIGHS INTO THE
MID 60S ACROSS THE MOUNTAINS...AND INTO THE LOW 70S ACROSS THE
PIEDMONT.
OVERNIGHT LOWS WILL FALL INTO THE 40S EACH NIGHT. BELIEVE CLOUD
COVER ON THURSDAY AND FRIDAY NIGHTS WILL KEEP FROST FORMATION
ISOLATED AT BEST...IF ANY AT ALL.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 320 PM EDT TUESDAY...
THE ENSEMBLE MEANS ARE FAIRLY HARMONIOUS, DEPICTING GENTLY
UNDULATING ZONAL FLOW ACROSS THE CONTIGUOUS UNITED STATES INTO EARLY
NEXT WEEK. THIS WILL BE A CHANGE FROM THE HIGH AMPLITUDE FLOW WE
HAVE ENDURED THIS MONTH SUGGESTING THE COOL AIR WILL FINALLY MAKE
A RETREAT. AS HEIGHTS/THICKNESSES RISE LOOK FOR TEMPERATURES TO
RETURN CLOSER TO NORMAL THIS WEEKEND AND FAVORING ABOVE NORMAL
READINGS...+4 TO +8 DEGREES...FOR THE FIRST FULL WEEK OF MAY.
THREAT FOR RAINFALL NEXT WEEK LOOKS MINIMAL FOR THE MID
ATLANTIC...WITH FOCUS FOR SHOWERS/STORMS CONFINED MAINLY TO THE MID
SECTION OF THE COUNTRY. IT WILL NOT BE ENTIRELY CLEAR HOWEVER...AS
WE STILL ANTICIPATE PERIODS OF DEBRIS CLOUDINESS TO MOVE QUICKLY
EAST WITHIN THE FAST ZONAL FLOW FROM THE STORMS MID CONUS.
WITH THE MODELS IN RELATIVE AGREEMENT...ANOTHER FEATURE OF INTEREST
SPARKED SOME CURIOSITY. BOTH THE GFS AND ECMWF SHOWED THE
DEVELOPMENT OF A CYCLONE...TROPICAL?...JUST OFF THE EAST COAST OF
FLORIDA BY THE MIDDLE OF NEXT WEEK. WHETHER THIS COMES TO FRUITION
OR NOT...IT DID CAUSE ME TO TAKE PAUSE AND LOOK AT THE CALENDAR. T-
MINUS 33 DAYS AND COUNTING TO THE OFFICIAL START OF HURRICANE
SEASON.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 745 AM EDT WEDNESDAY...
FOR TODAY WE WILL SEE CIRRUS INCREASING THEN MID AND LOWER CLOUDS
ARRIVING FROM THE SOUTH AFTER 18Z...WITH MORE CLOUD COVER BY
EVENING. MODELS SLOWING DOWN SHOWERS...BUT STILL LOOKS LIKE LIGHT
RAIN OR VERY LIGHT SHOWERS WILL AFFECT BCB/BLF/LWB AND LYH LATE
TODAY INTO TONIGHT. LIGHT FLOW AND INCREASING MOISTURE WITH LIGHT
PRECIP OVERNIGHT MAY HELP DEVELOP FOG AND LOWER CIGS...SO HAVE
HEDGED THE FORECAST THAT WAY AFTER 05Z AT ALL SITES.
EXTENDED AVIATION DISCUSSION...
THURSDAY CIGS MVFR OR WORSE EXPECTED WITH A BETTER THREAT OF
RAIN. MODELS OVERALL SHOWING BETTER COVERAGE FOR SHOWERS THURSDAY
WITH THE UPPER SHORTWAVE MOVING ACROSS THE KY/TN AREA LATER
THURSDAY AFTERNOON.
UPPER TROUGH AXIS REMAINS OVER THE AREA THURSDAY NIGHT INTO FRIDAY
AND NOT CONFIDENT AT THIS POINT ON CIGS...BUT THIS APPEARS TO
FAVOR THE MOUNTAINS KEEPING THE SHOWERS AT TIMES...WITH SUB VFR
CIGS. SHOULD SEE GRADUALLY IMPROVING CONDITIONS THOUGH AS WIND
STARTS TO PICK UP BETWEEN HIGH TO THE WEST OF THE MTNS AND LOW OFF
THE COAST. THE WEEKEND LOOKS DRIER AS HIGH MOVES OVERHEAD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS/WP
NEAR TERM...DS/WP
SHORT TERM...NF
LONG TERM...PM
AVIATION...AMS/MBS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
959 AM EDT WED APR 29 2015
.SYNOPSIS...
LOW PRESSURE DEVELOPING OVER THE SOUTHEASTERN UNITED STATES WILL
SLOWLY MOVE OFF THE MIDDLE ATLANTIC COAST BY FRIDAY. THIS WILL
BRING A CHANCE OF RAIN TO THE REGION THROUGH THE END OF THE
WORKWEEK. HIGH PRESSURE WILL THEN MOVE IN FROM THE SOUTHWEST...
BRINGING WARMER AND GENERALLY DRY CONDITIONS TO THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM EDT WEDNESDAY...
HAVE CONTINUED THE TREND OF BACKING OFF ON POPS TODAY BASED UPON
THE LATEST HRRR AND RNK WRK ARW GUIDANCE...ESPECIALLY EAST OF THE
CREST OF THE BLUE RIDGE. ACROSS THE MOUNTAINS...HAVE SLOWED THE
ONSET OF SHOWERS DEVELOPING ACROSS THE NORTHERN MOUNTAINS OF NORTH
CAROLINA...AND SPREADING NORTH INTO SOUTHEAST WEST VIRGINIA.
COVERAGE IS STILL EXPECTED TO BE THE GREATEST ACROSS THE FAR
SOUTHWEST PARTS OF THE REGION THIS AFTERNOON. HAVE ALSO DECREASED
THE EXTENT OF THE COVERAGE HEAD INTO...AND CONTINUING THROUGH MUCH
OF THE OVERNIGHT PERIOD. NO OTHER MAJOR CHANGES AT THIS TIME.
AS OF 734 AM EDT WEDNESDAY...
CONTINUE TO SEE SLOWER PROGRESS NORTH INTO THE DRIER AIR WE HAVE
IN PLACE...SO BACKED OFF POPS AGAIN AND LOWERED SKY COVER AND
TEMPS EARLY ON BASED ON OBS. STILL LOOKS LIKE MAINLY WRN CWA AFTER
MIDDAY TO SEE SOME SHOWERS/LIGHT RAIN...STILL
PATCHY/SCATTERED...WITH MORE COVERAGE TOWARD THE NC MTNS.
PREVIOUS DISCUSSION FROM 4 AM....
OVERALL THE FORECAST EXPECTED TO BE A LITTLE DRIER TODAY THAN
WHAT IS APPEARED 24 TO 60 HRS AGO. THIS MORNING...THE UPPER
LOW/TROUGH WAS SITUATED OVER THE LOWER MS VALLEY WITH WEAK FLOW
ALOFT ACROSS OUR AREA. MAIN AREA OF RAINFALL AND LIFT WAS WELL
SOUTH OF US FROM NRN ALABAMA INTO SC.
THE MODELS IN AGREEMENT WHICH SPELLS AN INCREASE IN MID AND HIGH
CLOUDS THIS MORNING...THEN MORE LOWER CLOUDS INTO THE SRN CWA BY LATE
MORNING WITH LIGHT RAIN/RAIN SHOWERS DEVELOPING WITH INCREASING
LIFT...THOUGH THE LOW LVL FLOW IS NOT THAT STRONG.
THE MODELS TAKE THE SFC LOW FROM THE FL PANHANDLE THIS MORNING TO
WELL OFF THE SC COAST BY THIS EVENING...WHILE NRN STREAM ENERGY
DIVES SE INTO THE GREAT LAKES FORMING A WEAK SFC LOW OVER THE MID
ATLANTIC. NOT TOO IMPRESSED WITH RAIN THREAT TODAY BUT THE PATTERN
FAVORS THE BLUE RIDGE AND WEST HAVING A BETTER CHANCE THAN THE
NORTHEAST AND EAST OVER THE PIEDMONT. HAVE BACKED OFF POPS THIS
MORNING AND SITUATE HIGH CHANCE TO LOW LIKELY POPS FROM THE NEW
RIVER VALLEY SOUTH AND WEST TO SRN WV/NW NC. QPF WITH THIS WILL BE
UNDER A QUARTER INCH...WITH MOST ONLY SEEING A FEW HUNDREDTHS.
FOR TEMPS...THINK ENOUGH SUNSHINE IN THE VA PIEDMONT THROUGH HIGH
CLOUDS ALLOWS READINGS TO CLIMB TO LOWER 70S THIS AFTERNOON WHILE IT
WILL STAY COOLER OVER THE SOUTHERN BLUE RIDGE WHERE SHOWERS/RAIN
MOVE IN QUICKER. THIS AREA WILL ONLY EXPERIENCE HIGHS IN THE 50S.
ELSEWHERE IT WILL BE IN THE 60S.
TONIGHT...THE SRN SHORTWAVE DIVE SOUTHEAST INTO THE GULF COAST
STATES...SOME BACKING FLOW AND DIGGING NRN STREAM SHORTWAVE TO ALLOW
SOME UPPER FORCING OVER THE MTNS. CONFIDENCE NOT HIGH THAT RAINFALL
WILL BE NUMEROUS...SO KEPT POPS 50 PERCENT OR LESS TIL DAWN..WHEN
THE UPPER TROUGH HEADS CLOSER WITH BETTER LIFT.
LOW TEMPS WILL BE IN THE 40S. WEAK SFC WINDS AND INCREASED SFC
MOISTURE EVEN WITH CLOUDS WILL LEAD TO A THREAT OF FOG AREAWIDE...SO
ADDED THAT TO THE FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM EDT WEDNESDAY...
THE MAIN WEATHER FEATURE TO BE CONCERNED WITH ON THURSDAY WILL BE AN
UPPER LEVEL LOW PRESSURE SYSTEM DESCENDING FROM THE GREAT LAKES
DURING THE MORNING...REACHING EASTERN KENTUCKY DURING THE EVENING.
THE COLD AIR ALOFT ASSOCIATED WITH THIS SYSTEM WILL SUPPORT
SCATTERED SHOWERS ACROSS THE AREA...WITH A FEW THUNDERSTORMS
DEVELOPING DURING THE AFTERNOON AND EVENING. THIS SYSTEM WILL DRIVE
VERY STEEP LAPSE RATES INTO OUR AREA...MEANING THAT WHILE AFTERNOON
HIGH TEMPERATURES WILL RANGE FROM THE LOW 60S ACROSS THE MOUNTAINS
TO THE UPPER 60S FURTHER EAST...TEMPERATURES WILL COOL RAPIDLY WITH
HEIGHT...FALLING BELOW FREEZING SOME FOUR TO SEVEN THOUSAND FEET
ABOVE THE SURFACE. WITH FREEZING HEIGHTS SO LOW...BELIEVE THAT EVEN
SHOWER ACTIVITY WILL BE CAPABLE OF PRODUCING SMALL HAIL...WHILE ONE
OR TWO OF THE STRONGER STORMS MAY PRODUCE QUARTER-SIZE HAIL. IN
ADDITION...WITH DRY AIR IN THE LOW LEVELS...MAY ALSO SEE A COUPLE OF
THE STRONGER CELLS PRODUCE LOCALLY GUSTY DOWNDRAFTS. WITH LOSS OF
DAYTIME HEATING AROUND SUNSET...SHOWER ACTIVITY IS EXPECTED TO
WEAKEN...BUT EXPECT A FEW SHOWERS TO LINGER THROUGH THE OVERNIGHT.
ON FRIDAY...THE UPPER LEVEL LOW WILL SHIFT QUICKLY FROM THE CENTRAL
APPALACHIANS DURING THE MORNING...TO OFF THE COAST DURING THE
AFTERNOON. EXPECT TO SEE SCATTERED SHOWERS REDEVELOP DURING THE
MORNING...MORE SO ACROSS THE PIEDMONT...AS DAYTIME HEATING
INCREASES. HOWEVER SHOWER ACTIVITY WILL DIMINISH DURING THE
AFTERNOON AS THE COLD AIR ALOFT EXITS...WITH DOWNSLOPE NORTHWESTERLY
FLOW TAKING OVER AND ADDING STABILITY TO THE ATMOSPHERE. THE PASSAGE
OF THE UPPER LOW WILL MAKE FOR A COOLER DAY...WITH AFTERNOON HIGHS
RANGING FROM THE UPPER 50S WEST TO THE LOW 60S EAST.
HIGH PRESSURE IN THE LOW LEVELS WILL BECOME ESTABLISHED FROM THE
MISSISSIPPI RIVER THROUGH THE APPALACHIANS ON SATURDAY...WHILE UPPER
LEVEL FLOW BEGINS A TRANSITION TO A MORE ZONAL PATTERN. THE
INCREASED SUNSHINE...ALBEIT WITH SCATTERED AFTERNOON CLOUDS...WILL
COMBINE WITH THE DOWNSLOPE WINDFLOW TO PUSH AFTERNOON HIGHS INTO THE
MID 60S ACROSS THE MOUNTAINS...AND INTO THE LOW 70S ACROSS THE
PIEDMONT.
OVERNIGHT LOWS WILL FALL INTO THE 40S EACH NIGHT. BELIEVE CLOUD
COVER ON THURSDAY AND FRIDAY NIGHTS WILL KEEP FROST FORMATION
ISOLATED AT BEST...IF ANY AT ALL.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 320 PM EDT TUESDAY...
THE ENSEMBLE MEANS ARE FAIRLY HARMONIOUS, DEPICTING GENTLY
UNDULATING ZONAL FLOW ACROSS THE CONTIGUOUS UNITED STATES INTO EARLY
NEXT WEEK. THIS WILL BE A CHANGE FROM THE HIGH AMPLITUDE FLOW WE
HAVE ENDURED THIS MONTH SUGGESTING THE COOL AIR WILL FINALLY MAKE
A RETREAT. AS HEIGHTS/THICKNESSES RISE LOOK FOR TEMPERATURES TO
RETURN CLOSER TO NORMAL THIS WEEKEND AND FAVORING ABOVE NORMAL
READINGS...+4 TO +8 DEGREES...FOR THE FIRST FULL WEEK OF MAY.
THREAT FOR RAINFALL NEXT WEEK LOOKS MINIMAL FOR THE MID
ATLANTIC...WITH FOCUS FOR SHOWERS/STORMS CONFINED MAINLY TO THE MID
SECTION OF THE COUNTRY. IT WILL NOT BE ENTIRELY CLEAR HOWEVER...AS
WE STILL ANTICIPATE PERIODS OF DEBRIS CLOUDINESS TO MOVE QUICKLY
EAST WITHIN THE FAST ZONAL FLOW FROM THE STORMS MID CONUS.
WITH THE MODELS IN RELATIVE AGREEMENT...ANOTHER FEATURE OF INTEREST
SPARKED SOME CURIOSITY. BOTH THE GFS AND ECMWF SHOWED THE
DEVELOPMENT OF A CYCLONE...TROPICAL?...JUST OFF THE EAST COAST OF
FLORIDA BY THE MIDDLE OF NEXT WEEK. WHETHER THIS COMES TO FRUITION
OR NOT...IT DID CAUSE ME TO TAKE PAUSE AND LOOK AT THE CALENDAR. T-
MINUS 33 DAYS AND COUNTING TO THE OFFICIAL START OF HURRICANE
SEASON.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 745 AM EDT WEDNESDAY...
FOR TODAY WE WILL SEE CIRRUS INCREASING THEN MID AND LOWER CLOUDS
ARRIVING FROM THE SOUTH AFTER 18Z...WITH MORE CLOUD COVER BY
EVENING. MODELS SLOWING DOWN SHOWERS...BUT STILL LOOKS LIKE LIGHT
RAIN OR VERY LIGHT SHOWERS WILL AFFECT BCB/BLF/LWB AND LYH LATE
TODAY INTO TONIGHT. LIGHT FLOW AND INCREASING MOISTURE WITH LIGHT
PRECIP OVERNIGHT MAY HELP DEVELOP FOG AND LOWER CIGS...SO HAVE
HEDGED THE FORECAST THAT WAY AFTER 05Z AT ALL SITES.
EXTENDED AVIATION DISCUSSION...
THURSDAY CIGS MVFR OR WORSE EXPECTED WITH A BETTER THREAT OF
RAIN. MODELS OVERALL SHOWING BETTER COVERAGE FOR SHOWERS THURSDAY
WITH THE UPPER SHORTWAVE MOVING ACROSS THE KY/TN AREA LATER
THURSDAY AFTERNOON.
UPPER TROUGH AXIS REMAINS OVER THE AREA THURSDAY NIGHT INTO FRIDAY
AND NOT CONFIDENT AT THIS POINT ON CIGS...BUT THIS APPEARS TO
FAVOR THE MOUNTAINS KEEPING THE SHOWERS AT TIMES...WITH SUB VFR
CIGS. SHOULD SEE GRADUALLY IMPROVING CONDITIONS THOUGH AS WIND
STARTS TO PICK UP BETWEEN HIGH TO THE WEST OF THE MTNS AND LOW OFF
THE COAST. THE WEEKEND LOOKS DRIER AS HIGH MOVES OVERHEAD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS/WP
NEAR TERM...DS/WP
SHORT TERM...NF
LONG TERM...PM
AVIATION...AMS/MBS/WP
AREA FORECAST DISCUSSION
NWS PORTLAND
301 PM PDT WED APR 29 2015
.SYNOPSIS...AN UPPER LEVEL TROUGH WAS MOVING THROUGH WESTERN
WASHINGTON AND NORTHWEST OREGON THIS AFTERNOON WITH A FEW SHOWERS...
ESPECIALLY NORTH OF SALEM AND ESPECIALLY OVER THE COAST RANGE. THIS
TROUGH HAS LOWERED TEMPS AS WELL TODAY. THERE IS ALSO A BAND OF
CLOUDS AND SHOWERS OFF THE COAST THAT WILL IMPACT THE COASTAL AREAS
THIS EVENING. ONCE THE UPPER UPPER LEVEL TROUGH MOVES THROUGH AND
THAT BAND WEAKENS...RATHER FLAT WESTERLY FLOW WILL BE OVER THE
EASTERN PACIFIC AND INTO THE PACIFIC NORTHWEST THAT WILL TEND TO
PRODUCE A MORE TYPICAL SUMMERTIME NIGHT AND MORNING CLOUD REGIME WITH
SUNSHINE MOST AFTERNOONS THROUGH THE REMAINDER OF THIS WEEK AND
THROUGH THIS WEEKEND. ANY WEAK PASSING DISTURBANCES WILL TEND TO BE
DRY AND MAINLY AFFECT THE COVERAGE OF THE MARINE CLOUDS. THE NEXT LOW
PRESSURE SYSTEM IS EXPECTED AROUND TUESDAY OF NEXT WEEK.
&&
.SHORT TERM...THE MODELS ALL SHOW AN UPPER LEVEL TROUGH AND ITS AXIS
MOVING THROUGH WESTERN WASHINGTON AND NORTHWEST OREGON THIS
AFTERNOON. THERE IS A BAND OF CLOUDS AND POSSIBLE SHOWERS ABOUT 60 NM
OFFSHORE THAT IS FORECAST TO REACH THE COAST THIS EVENING THEN WEAKEN
AND DISSIPATE AS IT MOVES INLAND. WE ALSO HAVE SOME OVERTURNING
CLOUDS AND SHOWERS OVER THE NORTHERN COASTAL MOUNTAINS THAT COULD
DRIFT OUT OVER THE ADJACENT VALLEYS THIS EVENING. THE SHOWERS SHOULD
MOSTLY END BY LATER TONIGHT THOUGH THERE SHOULD STILL BE A FAIR
AMOUNT OF CLOUDS AROUND.
BEHIND THE UPPER TROUGH...WE WILL SEE A RATHER FLAT WESTERLY FLOW
WITH MODERATELY HIGH 500 MB HEIGHTS NEAR 570 DM THAT WILL MAINLY
RESULT IN A TYPICAL SUMMERTIME ONSHORE FLOW PATTERN WITH A NIGHT AND
MORNING LOW CLOUDS AND PATCHY FOG REGIME. THURSDAY SHOULD SEE PLENTY
OF SUNSHINE MOST AREAS ONCE THE CLOUDS AND ANY PATCHY FOG CLEAR. ON
FRIDAY...THERE IS A WEAK DISTURBANCE PASSING BY THAT MIGHT KEEP SOME
SCATTERED CLOUDS AROUND ESPECIALLY NORTH IN THE AFTERNOON ONCE THE
MORNING CLOUDS BREAK UP. SATURDAY LOOKS SIMILAR TO FRIDAY...EXCEPT
THE MODELS INDICATE A LARGER COVERAGE OF LOW CLOUDS INLAND AND
SOUTHWARD IN THE WILLAMETTE VALLEY ON SATURDAY MORNING THAN ON FRIDAY
MORNING.
LOOK FOR TYPICAL SUMMERTIME TYPE BREEZES IN THE AFTERNOON AND EVENING
HOURS ALONG THE COAST THE NEXT FEW DAYS AS WELL. TOLLESON
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. A WEAK RIDGE OF HIGH
PRESSURE REMAIN OVER THE REGION FOR THE START OF NEXT WEEK. FOR
SUNDAY...EXPECT THE TREND OF SOME MORNING CLOUDS BECOMING MOSTLY
SUNNY IN THE AFTERNOON TO CONTINUE ALONG WITH HIGH TEMPERATURES IN
THE UPPER 60S TO NEAR 70 FOR THE WILLAMETTE VALLEY. INCREASED CLOUDS
WILL BEGIN TO MOVE INTO THE AREA ON MONDAY AFTERNOON AHEAD OF THE
NEXT FRONTAL SYSTEM WHAT WILL ARRIVE LATE MONDAY INTO EARLY TUESDAY.
THIS SYSTEM WILL BRING SOME COOLER MARINE AIR...WHICH WILL RETURN
TEMPERATURES BACK TO NEAR OR SLIGHTLY BELOW SEASONAL NORMS...ALONG
WITH A ROUND OF PRECIPITATION IN THE FORM OF RAIN. SNOW LEVELS MAY
FALL DOWN TO AROUND OR SLIGHTLY ABOVE THE CASCADE PASSES BY WEDNESDAY
WITH SOME RESIDUAL SHOWERS CONTINUING.CULLEN
&&
.AVIATION...VFR CONDITIONS THROUGH THIS EVENING. A FEW SHOWERS WILL
CONTINUE THROUGH SUNSET BUT MAINLY WILL NOT AFFECT TERMINAL
CONDITIONS MUCH. MAY SEE SOME PATCHY MVFR FOG OR LOW STRATUS EARLY
THURSDAY MORNING...GENERALLY AFTER 12Z. BEST LIKELIHOOD APPEARS TO BE
ALONG THE COAST BUT CANNOT RULE OUT INLAND SITES.
KPDX AND APPROACHES...EXPECT VFR WITH LIGHT NW FLOW TODAY AND
TONIGHT. THERE IS THE POTENTIAL FOR A FEW LIGHT SHOWERS BUT THEY ARE
NOT EXPECTED TO HAVE MUCH IMPACT ON THE TERMINAL. MVFR FOG OR LOW
STRATUS POSSIBLE EARLY THURSDAY...GENERALLY AFTER 12Z. BOWEN
&&
.MARINE...SEAS STUBBORNLY REMAIN AROUND 10 FT THIS AFTERNOON WITH
ALMOST 11 FT AT BUOY 29 AND 9 FT AT BUOY 50. GUIDANCE IS SHOWING
AN AREA OF 10 FT SEAS PERSISTING INTO THE EVENING IN THE OFFSHORE
NORTHERN WATERS SO HAVE EXTENDED THE SMALL CRAFT ADVISORY FOR SEAS
FOR THE NORTHERN WATERS. ONCE SEAS FINALLY DROP BELOW 10 FT LATER
TODAY...EXPECT THEM TO STAY DOWN AROUND 6 TO 8 FT THROUGH AT LEAST
EARLY NEXT WEEK.
WINDS WILL REMAIN RELATIVELY LIGHT OUT OF THE SW THIS AFTERNOON AS
HIGH PRESSURE NOSES INTO THE CENTRAL OREGON COAST. HIGH PRESSURE
WILL REMAIN IN THE AREA BUT WITH A SURFACE THERMAL LOW LIKELY
BUILDING OVER THE S OREGON/N CALIFORNIA COAST. THIS WILL LIKELY
BRING ADVISORY GUSTS STARTING THURSDAY AFTERNOON...WITH THE
STRONGEST WINDS OVER THE CENTRAL WATERS AND DURING THE AFTERNOON
HOURS EACH DAY THROUGH THE WEEKEND. BOWEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM PDT THIS
EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE
HEAD OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 5 PM
PDT THIS AFTERNOON.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
235 PM PDT WED APR 29 2015
.SYNOPSIS...
This evening will be breezy near the Cascades early...with only
spotty showers close to the BC border. Following this...there
won`t be much chance of any additional precipitation until Tuesday
or Wednesday of next week. Look for temperatures at or above
average through early next week before cooling markedly.
&&
.DISCUSSION...
Tonight and Thursday: Drier air filtering into the region behind
the cold front passage last night has really put a damper on the
post frontal shower activity this afternoon. Some flat cumulus is
building over the Cascade crest, Northeast Mtns and in the
Northern Panhandle. The higher terrain across these areas will see
the best shot at a passing shower through the early evening hours. Skies
will then clear out overnight. This will allow the surface to
radiate quite efficiently with temperatures bottoming out near to
or below freezing across the mountain valleys. This will be
especially so for the colder pockets around the region including
communities such as Winthrop, Republic, Metaline Falls and Deer
Park. Some frost may also be observed early in the morning on
Thursday. Temperatures on Thursday will be a few degrees warmer
compared to today with clear to mostly clear skies across much of
the region. /SVH
Thurs Nt through Wed: We kept the fcst uneventful and straight-forward
through Mon nt before a high level of uncertainty develops
beginning Tues. Until then, we only have an isolated threat of
rain showers for Fri in the mtns along the BC border in the
presence of a quick- moving, dry fropa. This may even be overdone.
The biggest event for Fri will turn out to be the gusty west gap
winds near and in the Cascades. This includes Wenatchee as cross-
Cascade pressure gradients tighten behind the front. These winds
will peak in the early evening. For the Tue and Wed fcst,
individual model run consistencies are very poor, and also
disagree significantly with the track of a moderately strong upper
low that digs SE down the BC coast. Given only two examples, the
GFS takes this low over Ern Wa and N Idaho by Wed, whereas the
ECMWF already has it well east out of the region into Alberta. The
consensus was more or less of a compromise between the two. The
main message, however, is clear: Expect a sharp cool-down that
will accompany an steadily-increasing shower and embedded thunder
threat Tue and Wed. bz
&&
.AVIATION...
18Z TAFS: A cold front is pushing east and south of the central to
northern ID Panhandle. A tightening pressure gradient behind the
front will result in breezy westerly winds through the afternoon
with gusts up to 20-25 mph. Any post frontal showers will likely
be confined to the mountains along the Cascade crest, in northeast
WA and in the ID Panhandle. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 65 43 72 43 67 / 0 0 0 0 0 0
Coeur d`Alene 35 63 38 71 40 66 / 0 0 0 0 0 0
Pullman 34 63 38 71 41 66 / 0 0 0 0 0 0
Lewiston 39 71 42 78 44 72 / 0 0 0 0 0 0
Colville 36 69 43 74 39 71 / 20 0 10 10 0 10
Sandpoint 32 62 35 68 37 66 / 10 0 10 10 0 10
Kellogg 35 61 38 67 40 64 / 0 0 0 10 0 10
Moses Lake 37 73 42 76 42 73 / 0 0 0 0 0 0
Wenatchee 44 72 47 75 47 74 / 0 0 0 0 0 0
Omak 36 71 42 74 42 71 / 0 0 0 10 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
235 PM PDT WED APR 29 2015
.SYNOPSIS...
This evening will be breezy near the Cascades early...with only
spotty showers close to the BC border. Following this...there
won`t be much chance of any additional precipitation until Tuesday
or Wednesday of next week. Look for temperatures at or above
average through early next week before cooling markedly.
&&
.DISCUSSION...
Tonight and Thursday: Drier air filtering into the region behind
the cold front passage last night has really put a damper on the
post frontal shower activity this afternoon. Some flat cumulus is
building over the Cascade crest, Northeast Mtns and in the
Northern Panhandle. The higher terrain across these areas will see
the best shot at a passing shower through the early evening hours. Skies
will then clear out overnight. This will allow the surface to
radiate quite efficiently with temperatures bottoming out near to
or below freezing across the mountain valleys. This will be
especially so for the colder pockets around the region including
communities such as Winthrop, Republic, Metaline Falls and Deer
Park. Some frost may also be observed early in the morning on
Thursday. Temperatures on Thursday will be a few degrees warmer
compared to today with clear to mostly clear skies across much of
the region. /SVH
Thurs Nt through Wed: We kept the fcst uneventful and straight-forward
through Mon nt before a high level of uncertainty develops
beginning Tues. Until then, we only have an isolated threat of
rain showers for Fri in the mtns along the BC border in the
presence of a quick- moving, dry fropa. This may even be overdone.
The biggest event for Fri will turn out to be the gusty west gap
winds near and in the Cascades. This includes Wenatchee as cross-
Cascade pressure gradients tighten behind the front. These winds
will peak in the early evening. For the Tue and Wed fcst,
individual model run consistencies are very poor, and also
disagree significantly with the track of a moderately strong upper
low that digs SE down the BC coast. Given only two examples, the
GFS takes this low over Ern Wa and N Idaho by Wed, whereas the
ECMWF already has it well east out of the region into Alberta. The
consensus was more or less of a compromise between the two. The
main message, however, is clear: Expect a sharp cool-down that
will accompany an steadily-increasing shower and embedded thunder
threat Tue and Wed. bz
&&
.AVIATION...
18Z TAFS: A cold front is pushing east and south of the central to
northern ID Panhandle. A tightening pressure gradient behind the
front will result in breezy westerly winds through the afternoon
with gusts up to 20-25 mph. Any post frontal showers will likely
be confined to the mountains along the Cascade crest, in northeast
WA and in the ID Panhandle. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 65 43 72 43 67 / 0 0 0 0 0 0
Coeur d`Alene 35 63 38 71 40 66 / 0 0 0 0 0 0
Pullman 34 63 38 71 41 66 / 0 0 0 0 0 0
Lewiston 39 71 42 78 44 72 / 0 0 0 0 0 0
Colville 36 69 43 74 39 71 / 20 0 10 10 0 10
Sandpoint 32 62 35 68 37 66 / 10 0 10 10 0 10
Kellogg 35 61 38 67 40 64 / 0 0 0 10 0 10
Moses Lake 37 73 42 76 42 73 / 0 0 0 0 0 0
Wenatchee 44 72 47 75 47 74 / 0 0 0 0 0 0
Omak 36 71 42 74 42 71 / 0 0 0 10 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1040 AM PDT WED APR 29 2015
.SYNOPSIS...
Today will be breezy and cooler with afternoon temperatures in the
60s over much of the Inland Northwest. Showers today will be
spotty, and there won`t be much chance of any additional
precipitation until Tuesday or Wednesday of next week. Look for
temperatures at or above average through early next week.
&&
.DISCUSSION...
Morning update to remove thunderstorms in the forecast for this
afternoon. The GFS solution is the most unstable with a bullseye
of CAPE of around 250 J/kg and LIs of -3 over the Northeast Mtns.
This appears to be overdone compared to the ECMWF and NAM
solutions. The GFS seems to be holding on to dew points in the
upper 30s. The NAM and RUC show this moisture mixing out a bit
better with dew points dropping more into the lower and mid 30s.
Considering that there is a dry slot moving into the region behind
last night`s cold front passage, I am inclined to believe the less
unstable model solutions for this afternoon (especially when
little rain fell with the front). Best potential for any
thunderstorms today appear to be under the upper level cold pool
in BC and ahead of the mid level front across the southern ID
Panhandle into southwestern MT. /SVH
&&
.AVIATION...
18Z TAFS: A cold front is pushing east and south of the central to
northern ID Panhandle. A tightening pressure gradient behind the
front will result in breezy westerly winds through the afternoon
with gusts up to 20-25 mph. Any post frontal showers will likely
be confined to the mountains along the Cascade crest, in northeast
WA and in the ID Panhandle. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 62 38 63 43 72 43 / 10 10 0 0 0 0
Coeur d`Alene 60 36 62 38 71 40 / 10 10 0 0 0 0
Pullman 59 34 62 38 71 41 / 0 0 0 0 0 0
Lewiston 66 40 70 42 78 44 / 0 0 0 0 0 0
Colville 66 37 68 43 74 39 / 20 20 0 10 10 0
Sandpoint 60 33 61 35 68 37 / 10 10 0 10 10 0
Kellogg 57 36 60 38 67 40 / 10 10 0 0 10 0
Moses Lake 69 39 71 42 76 42 / 0 0 0 0 0 0
Wenatchee 68 46 72 47 75 47 / 0 0 0 0 0 0
Omak 67 36 70 42 74 42 / 0 0 0 0 10 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND
312 AM PDT WED APR 29 2015
.SYNOPSIS...AN UPPER LEVEL TROUGH THAT WAS ALONG THE COAST EARLY WED
MORNING WILL MOVE INLAND TODAY...AND E OF THE REGION TONIGHT. HIGH
PRES OFF THE COAST WILL THEN KEEP AN ONSHORE FLOW GOING THROUGH THE
WEEKEND FOR MAINLY DRY WEATHER WITH TEMPERATURES JUST A LITTLE ABOVE
NORMAL. EARLY NEXT WEEK ANOTHER UPPER LEVEL TROUG IS EXPECTED TO
MOVE BACK OVER THE PACIFIC NW.
&&
.SHORT TERM...WATER VAPOR PICTURES EARLY THIS MORNING SHOWED THE
MAIN UPPER TROUGH STILL OFF THE COAST...WITH A SHORTWAVE ROTATING
AROUND THE BASE OF THE LOW POISED TO MOVE INLAND LATER TODAY ACROSS
WA AND NW OREGON. IR PICTURES SHOWED CLOUDS REMAINING OVER THE
CASCADES AND FOOTHILLS...WHILE ELSEWHERE MOST OF THE LOW CLOUDS HAD
CLEARED OUT. MODELS ALL CONTINUE TO INDICATE HOWEVER LOW LEVELS
REMAINING MOIST BELOW 850 MB THIS MORNING...ESP ACROSS THE N WHERE
BEST RESIDUAL ONSHORE FLOW CONTINUED. EXPECT SOME REDEVELOPMENT OF
CLOUDS TODAY. SOME OF THE SCATTERED CONVECTIVE OFFSHORE WERE SHOWING
LIGHT SHOWERS ASSOCIATED WITH THEM ON RADAR OFF THE N OREGON AND S
WA COAST. WILL NEED TO KEEP A LOW POP IN FOR SHOWERS TODAY ACROSS
THE N AS THE UPPER SHORTWAVE MOVES ACROSS.
THE THREAT OF SHOWERS WILL DROP OFF THIS EVENING AS THE MAIN TROUGH
MOVES OFF TO THE E. SURFACE HIGH PRES OFFSHORE WITH A RATHER FLAT
WESTERLY FLOW ALOFT THROUGH THE REST OF THE WEEK WILL KEEP THE
REGION DRY. AREAS OF MAINLY MORNING CLOUDS ARE LIKELY ESPECIALLY
ACROSS THE N IN THE NW ONSHORE FLOW THU AND FRI.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. FRIDAY NIGHT
THROUGH TUESDAY. ZONAL FLOW ALOFT WILL PERSIST OVER THE REGION THIS
WEEKEND WITH GENERALLY PARTLY CLOUDY SKIES AND DRY WEATHER. WHILE A
FEW UPPER LEVEL DISTURBANCES MAY MOVE ACROSS THE REGION...ANY
PRECIPITATION SHOULD REMAIN WELL TO THE NORTH IN NORTHERN
WASHINGTON/SOUTHERN CANADA. TEMPERATURES WILL REMAIN A FEW DEGREES
ABOVE NORMAL ACROSS THE VALLEY...BUT LIKELY CLOSER TO NORMAL AT THE
COAST AS WEAK ONSHORE FLOW DEVELOPS BY THE END OF THE WEEKEND.
INCREASING CLOUDS AND COOLING TEMPERATURES EARLY NEXT WEEK AS THE
NEXT FRONTAL SYSTEM APPROACHES WITH COOLER MARINE AIR AND SOME
SHOWERS POSSIBLE. CULLEN
&&
.AVIATION...THE MID LEVEL CLOUDS THAT WERE ACROSS THE REGION LAST
EVENING HAVE MOSTLY DISSIPATED EARLY THIS MORNING. THE EXCEPTION
IS IN THE CASCADES...WHICH APPEAR TO REMAIN OBSCURED BASED ON THE
LATEST SATELLITE IMAGERY. WITH HIGH PRES NOSING INTO THE REGION
THIS MORNING AND DEW POINTS SPREADS ONLY A COUPLE OF DEGREES IN
MANY SPOTS...EXPECT WE MAY SEE SOME PATCHY FOG OR LOW STRATUS FORM
BETWEEN 11Z AND 15Z. THEN EXPECT MAINLY VFR CONDITIONS ACROSS THE
REGION TODAY AND TONIGHT. A WEAK UPPER LEVEL TROUGH WILL MOVE
THROUGH LATER TODAY AND MAY BRING A FEW LIGHT SHOWERS...MAINLY
NORTH OF KSLE.
KPDX AND APPROACHES...PATCHY FOG OR LOW STRATUS MAY FORM AROUND
THE TERMINAL BETWEEN 11Z AND 15Z. OTHERWISE EXPECT VFR WITH LIGHT
NW FLOW TODAY AND TONIGHT. THERE IS THE POTENTIAL FOR A FEW BRIEF
SHOWERS THIS AFTERNOON. PYLE
&&
.MARINE...WINDS ARE RELATIVELY LIGHT OUT OF THE WEST/NORTHWEST THIS
MORNING AS WEAK HIGH PRES HAS BUILD OVER THE COASTAL WATERS. A
WEAK SURFACE TROUGH WILL MOVE THROUGH THE WATERS THIS
AFTERNOON...BUT LOOKS LIKE IT WILL HAVE LITTLE EFFECT OTHER THAN
TURNING THE WINDS BRIEFLY SOUTHWESTERLY. HIGH PRES RETURNS ON
THU...WITH A SURFACE THERMAL LOW LIKELY BUILDING OVER THE S
OREGON/N CALIFORNIA COAST. THIS WILL LIKELY BRING ADVISORY GUSTS
THIS WEEKEND...WITH THE STRONGEST WINDS OVER THE CENTRAL WATERS.
SEAS ARE CURRENTLY SITTING AROUND 10 TO 11 FT DUE TO NORTHWESTERLY
SWELL BEHIND THE FRONT THAT MOVED THROUGH YESTERDAY. EXPECT THE
SEAS TO GRADUALLY SUBSIDE TODAY...DROPPING BELOW 10 FT THIS
MORNING AND EVENTUALLY REACHING 7 TO 8 FT LATE TONIGHT. SEAS
SHOULD REMAIN BELOW 10 FT THROUGH EARLY NEXT WEEK. PYLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT THIS
MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
4 AM PDT EARLY THIS MORNING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM NOON
TODAY TO 5 PM PDT THIS AFTERNOON.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
253 AM PDT WED APR 29 2015
.SYNOPSIS...
Today will be breezy and cooler with afternoon temperatures in the
60s over much of the Inland Northwest. Showers today will be
spotty, and there won`t be much chance of any additional
precipitation until Tuesday or Wednesday of next week. Look for
temperatures at or above average through early next week.
&&
.DISCUSSION...
Today through Thursday night...A south-north oriented narrow band
of rain showers associated with a cold front over extreme Eastern
Washington will track into North Idaho between 4 am and 8 am this
morning. A pocket of mid level instability along the front will
lead to locally moderate rain showers. Much drier air is moving in
behind the front both aloft and at the surface which will limit
post frontal shower activity today. Most of the showers this
afternoon will be over the northern mountains around Colville,
Northport, and Metaline Falls. GFS model even shows CAPE values of
200-400 J/KG in this area which could result in an isolated
thunderstorm. Convection will die down this evening with the loss
of daytime heating.
Cold advection across the area behind the front will lead to much
cooler temperatures compared to yesterday...with highs closer to
seasonal normals. Locally breezy winds are expected today through
the Cascade gaps...as well as the Upper Columbia Basin, Spokane
area, and Palouse with gusts around 30 mph expected. Drier air
mixing down over Central Washington with dew points falling into
the lower to mid 20s will lead to low relative humidities values
in the teens as well.
For overnight tonight into Thursday night a series of system pass
north of the Canadian border with a dry zonal (westerly) flow over
the area. Pressure gradient relax a bit on Thursday with sustained
winds over most of the area ranging from 5-15 mph. JW
Friday through Monday: A rather benign weather pattern is progged
by the medium range models Friday through Monday. Not only is weak
west to east (zonal) pattern forecast over the Pacific Northwest,
but it looks to be the predominant flow regime for the remainder of
the lower 48 states. We raised temperatures a bit for Friday ahead
of a weak cold front. Little more than an increase in westerly
winds is expected with the passage of the dry cold front Friday
evening. With the upper level jet axis well north of the Canadian
border, the models are forecasting very little moisture along and
behind Friday evening`s front. The weekend looks pretty favorable
for outdoor activities with an abundance of sunshine and afternoon
temperatures about five degrees above average.
Tuesday and Wednesday: There is reasonably good agreement between
the GFS, ECMWF, Canadian and the GFS Ensemble Mean that a slow
moving upper low will approach the Washington/British Columbia
coast Tuesday into Wednesday. This pattern should increase our
chance for showers and possibly some afternoon thunderstorms
Tuesday and Wednesday. The increasing on-shore flow will also have
the potential to produce locally breezy winds through the Cascade
Gaps in places like Wenatchee, Chelan, and Vantage. /GKoch
&&
.AVIATION...
06Z TAFS: A cold front will pass through KMWH this evening and
east across the remainder of the area tonight. Showers are
expected with the front for the eastern TAF sites. VFR conditions
are likely at all TAF sites through 06Z Thursday...except for the
possibility of brief MVFR ceilings in heavier shower cores after
06Z tonight at the eastern TAF sites. Gusty southwest winds will
follow the frontal passage. Expect winds to diminish after sunset
Wednesday. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 62 38 63 43 72 43 / 10 10 0 0 0 0
Coeur d`Alene 60 36 62 38 71 40 / 40 10 0 0 0 0
Pullman 59 34 62 38 71 41 / 40 0 0 0 0 0
Lewiston 66 40 70 42 78 44 / 30 0 0 0 0 0
Colville 66 37 68 43 74 39 / 20 20 0 10 10 0
Sandpoint 60 33 61 35 68 37 / 50 10 0 10 10 0
Kellogg 57 36 60 38 67 40 / 50 10 0 0 10 0
Moses Lake 69 39 71 42 76 42 / 0 0 0 0 0 0
Wenatchee 68 46 72 47 75 47 / 0 0 0 0 0 0
Omak 67 36 70 42 74 42 / 0 0 0 0 10 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
253 AM PDT WED APR 29 2015
.SYNOPSIS...
Today will be breezy and cooler with afternoon temperatures in the
60s over much of the Inland Northwest. Showers today will be
spotty, and there won`t be much chance of any additional
precipitation until Tuesday or Wednesday of next week. Look for
temperatures at or above average through early next week.
&&
.DISCUSSION...
Today through Thursday night...A south-north oriented narrow band
of rain showers associated with a cold front over extreme Eastern
Washington will track into North Idaho between 4 am and 8 am this
morning. A pocket of mid level instability along the front will
lead to locally moderate rain showers. Much drier air is moving in
behind the front both aloft and at the surface which will limit
post frontal shower activity today. Most of the showers this
afternoon will be over the northern mountains around Colville,
Northport, and Metaline Falls. GFS model even shows CAPE values of
200-400 J/KG in this area which could result in an isolated
thunderstorm. Convection will die down this evening with the loss
of daytime heating.
Cold advection across the area behind the front will lead to much
cooler temperatures compared to yesterday...with highs closer to
seasonal normals. Locally breezy winds are expected today through
the Cascade gaps...as well as the Upper Columbia Basin, Spokane
area, and Palouse with gusts around 30 mph expected. Drier air
mixing down over Central Washington with dew points falling into
the lower to mid 20s will lead to low relative humidities values
in the teens as well.
For overnight tonight into Thursday night a series of system pass
north of the Canadian border with a dry zonal (westerly) flow over
the area. Pressure gradient relax a bit on Thursday with sustained
winds over most of the area ranging from 5-15 mph. JW
Friday through Monday: A rather benign weather pattern is progged
by the medium range models Friday through Monday. Not only is weak
west to east (zonal) pattern forecast over the Pacific Northwest,
but it looks to be the predominant flow regime for the remainder of
the lower 48 states. We raised temperatures a bit for Friday ahead
of a weak cold front. Little more than an increase in westerly
winds is expected with the passage of the dry cold front Friday
evening. With the upper level jet axis well north of the Canadian
border, the models are forecasting very little moisture along and
behind Friday evening`s front. The weekend looks pretty favorable
for outdoor activities with an abundance of sunshine and afternoon
temperatures about five degrees above average.
Tuesday and Wednesday: There is reasonably good agreement between
the GFS, ECMWF, Canadian and the GFS Ensemble Mean that a slow
moving upper low will approach the Washington/British Columbia
coast Tuesday into Wednesday. This pattern should increase our
chance for showers and possibly some afternoon thunderstorms
Tuesday and Wednesday. The increasing on-shore flow will also have
the potential to produce locally breezy winds through the Cascade
Gaps in places like Wenatchee, Chelan, and Vantage. /GKoch
&&
.AVIATION...
06Z TAFS: A cold front will pass through KMWH this evening and
east across the remainder of the area tonight. Showers are
expected with the front for the eastern TAF sites. VFR conditions
are likely at all TAF sites through 06Z Thursday...except for the
possibility of brief MVFR ceilings in heavier shower cores after
06Z tonight at the eastern TAF sites. Gusty southwest winds will
follow the frontal passage. Expect winds to diminish after sunset
Wednesday. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 62 38 63 43 72 43 / 10 10 0 0 0 0
Coeur d`Alene 60 36 62 38 71 40 / 40 10 0 0 0 0
Pullman 59 34 62 38 71 41 / 40 0 0 0 0 0
Lewiston 66 40 70 42 78 44 / 30 0 0 0 0 0
Colville 66 37 68 43 74 39 / 20 20 0 10 10 0
Sandpoint 60 33 61 35 68 37 / 50 10 0 10 10 0
Kellogg 57 36 60 38 67 40 / 50 10 0 0 10 0
Moses Lake 69 39 71 42 76 42 / 0 0 0 0 0 0
Wenatchee 68 46 72 47 75 47 / 0 0 0 0 0 0
Omak 67 36 70 42 74 42 / 0 0 0 0 10 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1021 PM PDT TUE APR 28 2015
.SYNOPSIS...
An approaching cold front will lead to an increase in winds and
much cooler temperatures through Wednesday, along with a chance
for showers and a possible thunderstorm mainly tonight. A few
showers may linger over the mountains on Wednesday. This will be
followed by a general drying trend into the weekend with
temperatures warming near to or slightly above normal.
&&
.DISCUSSION...
No update needed to the forecast this evening as the current
forecast package is right on track with the timing of the frontal
system that will cross the Inland Northwest tonight. radar is
showing the prefrontal precipitation band just west of Moses Lake
area as of 830 pm. The HRRR has a good handle on this and has the
band of showers moving through eastern WA and into north Idaho
over the next 6 hours. Winds will increase and become gusty behind
the front tonight. There is still the possibility of a few rumbles
of thunder across the northeast tonight as the upper level jet
slides over the area but confidence is low for more than a strike
or two. /Kelch
&&
.AVIATION...
06Z TAFS: A cold front will pass through KMWH this evening and
east across the remainder of the area tonight. Showers are
expected with the front for the eastern TAF sites. VFR conditions
are likely at all TAF sites through 06Z Thursday...except for the
possibility of brief MVFR ceilings in heavier shower cores after
06Z tonight at the eastern TAF sites. Gusty southwest winds will
follow the frontal passage. Expect winds to diminish after sunset
Wednesday. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 61 38 63 42 70 / 60 30 10 0 0 10
Coeur d`Alene 42 59 35 62 38 68 / 50 50 10 0 0 10
Pullman 43 57 35 61 38 69 / 30 50 10 0 0 10
Lewiston 49 65 40 68 43 76 / 20 30 10 0 0 10
Colville 45 64 36 69 40 73 / 60 30 20 10 10 10
Sandpoint 40 60 32 62 35 67 / 50 70 10 10 10 10
Kellogg 41 57 34 60 37 67 / 20 60 10 10 0 10
Moses Lake 41 67 38 71 41 75 / 20 0 10 0 0 10
Wenatchee 43 65 43 71 46 75 / 10 0 10 0 0 10
Omak 42 66 37 70 41 73 / 10 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
238 AM EDT FRI MAY 1 2015
.SYNOPSIS...
LOW PRESSURE JUST OFF THE NORTH CAROLINA COAST TODAY WILL BE
FARTHER OFFSHORE SATURDAY AND SUNDAY. A PRESSURE RIDGE IN THE
MISSISSIPPI RIVER VALLEY TODAY WILL SHIFT EASTWARD. THE RIDGE
WILL EXTEND ALONG THE EAST COAST SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SOME WRAP-AROUND MOISTURE ASSOCIATED WITH LOW PRESSURE JUST OFF THE
NORTH CAROLINA COAST WILL AFFECT MAINLY THE NORTHEAST PART OF THE
FORECAST AREA TODAY. INSTABILITY ASSOCIATED WITH THE UPPER LOW
OVER NORTH CAROLINA WILL BE GREATER IN THE NORTH PART OF THE
FORECAST AREA. THE MODELS INDICATE LIFT ASSOCIATED WITH A
SHORTWAVE TROUGH ROTATING AROUND THE UPPER LOW WILL HAVE MOVED OUT
OF THE FORECAST AREA THIS AFTERNOON. THE PATTERN SUPPORTS A CHANCE
OF SHOWERS MAINLY IN THE NORTHEAST SECTION EARLY TODAY. THE LOW
GUIDANCE POPS APPEAR REASONABLE BECAUSE OF CONTINUED SHALLOW
MOISTURE. THE HIGH-RESOLUTION MODELS DISPLAY WIDELY SCATTERED COVERAGE
IN THE NORTH PART. THUNDERSTORMS COULD POSSIBLY OCCUR IN THE NORTH
PART CLOSER TO THE COLDER TEMPERATURES ALOFT. LOW WET-BULB ZERO
HEIGHTS FAVOR HAIL...BUT ANY HAIL SHOULD BE SMALL BECAUSE OF WEAK
INSTABILITY. USED THE COOLER HIGH TEMPERATURE GUIDANCE BECAUSE OF
THE COLD TEMPERATURES ALOFT.
ANY SHOWERS SHOULD DISSIPATE TONIGHT WITH THE LOSS OF HEATING. THE
MODELS DISPLAY MOISTURE FURTHER DIMINISHING AS THE AREA OF LOW
PRESSURE OFF THE NORTH CAROLINA COAST SHIFTS A LITTLE FARTHER
EASTWARD. IT WILL BE A COOL NIGHT. THE GUIDANCE WAS CLOSE WITH
LOWS AROUND 50.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
THE PRESSURE RIDGE APPROACHING FROM THE WEST SHOULD EXTEND THROUGH
THE AREA SUNDAY. EXPECT DRY WEATHER. THE TEMPERATURE GUIDANCE WAS
CONSISTENT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MODELS HAVE BEEN CONSISTENT WITH RIDGING DOMINATING THROUGH
THE MEDIUM-RANGE PERIOD. THE GFS...ECMWF...AND EKD MOS HAVE POPS
LESS THAN 20 PERCENT THROUGH THE PERIOD. THE MOS HAS LOW TEMPERATURES
IN THE 50S WITH HIGHS IN THE LOWER AND MIDDLE 80S.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WEAK SURFACE LOW ALONG
THE CAROLINA COAST. UPPER LOW SINKING SOUTHEAST ACROSS NORTH
CAROLINA. WIDELY SCATTERED SHOWERS ASSOCIATED WITH UPPER LOW MOVING
SOUTHEAST FROM THE UPSTATE INTO PORTIONS OF THE NORTHERN AND CENTRAL
MIDLANDS. LATEST HRRR GUIDANCE AND RADAR TRENDS SUGGEST SOME SHOWERS
MAY MOVE NEAR THE TERMINALS IN THE 06Z-08Z TIME FRAME. PRECIPITATION
WILL BE LIGHT AND VSBYS WILL REMAIN VFR. GIVEN LATEST RADAR
TRENDS...WILL MENTION -RA AT CAE/CUB UNTIL 08Z. WINDS LIGHT AND
MAINLY SOUTHWEST TO NORTHWEST DURING THE PRE-DAWN HOURS. DRIER AIR
IN PLACE AND BOUNDARY LAYER MIXING SHOULD PREVENT FOG DEVELOPMENT
BEFORE SUNRISE. SCATTERED TO BROKEN STRATO-CU EXPECTED LATER TODAY
WITH GUSTY NORTHWEST TO NORTH WINDS AS SURFACE LOW ALONG THE
CAROLINA COAST MOVES TO THE NORTHEAST. WINDS WILL DIMINISH THIS
EVENING.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS EXPECTED THROUGH THE
PERIOD WITH HIGH PRESSURE OVER THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
134 AM EDT FRI MAY 1 2015
.SYNOPSIS...
LOW PRESSURE OFF THE CAROLINA COAST WILL TRACK TO THE NORTHEAST
AWAY FROM THE AREA FOR THE WEEKEND. AN UPPER-LEVEL LOW WILL
REMAIN IN THE REGION THROUGH FRIDAY. THIS FEATURE WILL GENERATE
WIDELY SCATTERED MAINLY AFTERNOON SHOWERS. HIGH PRESSURE WILL
BUILD INTO THE REGION THROUGH THE WEEKEND INTO NEXT WEEK WITH DRY
AND SEASONABLE CONDITIONS.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
SURFACE LOW PRESSURE OFF THE NC COAST WILL LIFT NORTHEAST
OVERNIGHT AS HIGH PRESSURE OVER THE CENTRAL CONUS BUILDS INTO THE
REGION. AN UPPER LEVEL LOW OVER THE OHIO RIVER VALLEY WILL MOVE
SOUTHWARD INTO NC BY SUNRISE FRIDAY. COLD AIR ALOFT ASSOCIATED
WITH THE UPPER LOW AND A SHORT WAVE ROTATING AROUND THE UPPER LOW
WILL BRING CLOUDS AND SCATTERED TO ISOLATED SHOWERS TO THE
MIDLANDS AND UPPER SAVANNAH RIVER AREA OVERNIGHT. THUS...HAVE
INCREASED POPS FOR THE OVERNIGHT ALTHOUGH RAINFALL AMOUNTS WILL BE
LIGHT. OVERNIGHT LOWS ARE EXPECTED TO FALL INTO THE UPPER 40S AND
LOWER 50S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY/...
SLIGHT CHANCE OF SHOWERS IN THE NORTHERN MIDLANDS/PEE DEE REGIONS
THROUGH FRIDAY MORNING AS A STRONG S/W MOVES SE THROUGH THE AREA.
MODELS HAVE THE S/WV CLEARING THE AREA FRIDAY AFTERNOON. HIGH
PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND WITH MOSTLY
CLEAR SKIES AND BELOW NORMAL TEMPS. HIGHS WILL BE IN THE LOWER 70S
FRIDAY AND MID TO UPPER 70S SATURDAY. OVERNIGHT LOWS WILL BE IN
THE UPPER 40S TO LOWER 50S FRIDAY NIGHT AND IN THE 50S SATURDAY
NIGHT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MODELS HAVE BEEN CONSISTENT SHOWING AN UPPER LEVEL RIDGE MOVING OVER
THE REGION AT THE BEGINNING OF NEXT WEEK. SURFACE HIGH PRESSURE IS
EXPECTED TO DOMINATE FROM MONDAY THROUGH THURSDAY. POPS NEXT WEEK
ARE EXPECTED TO BE LESS THAN 20 PERCENT. TEMPERATURES ARE LIKELY TO
BE NEAR NORMAL WITH HIGHS IN THE LOW TO MID 80S.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WEAK SURFACE LOW ALONG
THE CAROLINA COAST. UPPER LOW SINKING SOUTHEAST ACROSS NORTH
CAROLINA. WIDELY SCATTERED SHOWERS ASSOCIATED WITH UPPER LOW MOVING
SOUTHEAST FROM THE UPSTATE INTO PORTIONS OF THE NORTHERN AND CENTRAL
MIDLANDS. LATEST HRRR GUIDANCE AND RADAR TRENDS SUGGEST SOME SHOWERS
MAY MOVE NEAR THE TERMINALS IN THE 06Z-08Z TIME FRAME. PRECIPITATION
WILL BE LIGHT AND VSBYS WILL REMAIN VFR...BUT CONFIDENCE IS LOW
WHETHER TO MENTION IN THE TAFS SO WILL LEAVE OUT FOR NOW. WINDS
LIGHT AND MAINLY SOUTHWEST TO NORTHWEST DURING THE PRE-DAWN HOURS.
DRIER AIR IN PLACE AND BOUNDARY LAYER MIXING SHOULD PREVENT FOG
DEVELOPMENT BEFORE SUNRISE. SCATTERED TO BROKEN STRATO-CU EXPECTED
LATER TODAY WITH GUSTY NORTHWEST TO NORTH WINDS AS SURFACE LOW ALONG
THE CAROLINA COAST MOVES TO THE NORTHEAST. WINDS WILL DIMINISH THIS
EVENING.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS EXPECTED THROUGH THE
PERIOD WITH HIGH PRESSURE OVER THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
355 AM CDT Fri May 1 2015
.SHORT TERM...(Today and Tonight)
Issued at 332 AM CDT FRI MAY 1 2015
Water vapor loop shows nearly zonal stronger flow aloft across the
northern Rockies and northern Plains states with a well-defined
shortwave trough from the eastern Dakotas into northwest MN. A band
of showers is associated with lift ahead of upper trough moving
through western MN trailing back into northeast Nebraska at this
time. Forcing associated with this system should stay well to north
of forecast area today. However, regional radar loops show showers
and isolated thunderstorms occurring with trailing cold front/trough
from central Nebraska into northwest KS. There is some disagreement
among models but NAM, RAP and HRRR show remnants of this high-based
precip making it into north central KS by early afternoon and then
moving across far northeastern KS during the rest of the afternoon.
While confidence is not high in measurable precip with this
activity, have continued slight chance POPs for far northern
counties this afternoon. Something similar could happen again
tonight with developing showers and thunderstorms over western
Nebraska, which is forecast by some models to persist and move into
far northern parts of our area tonight. Once again, without a
stronger upper level system or recognizable front coming through,
this will be a low chance event, with slightly better chances to our
north.
Considerable mid and high level cloudiness today could make high
temp forecast tricky. Still think enough sunshine will get through
to allow highs to reach the mid to upper 70s.
.LONG TERM...(Saturday through Thursday)
Issued at 332 AM CDT FRI MAY 1 2015
By Saturday, fairly zonal mid-level flow will be in place with
surface high pressure prevailing across the southeastern U.S. and
surface low pressure extending along the High Plains. Models
continue to show a few weak embedded shortwaves developing within
the zonal flow on Saturday as a vort max skims just north of the
CWA. However, with no surface feature to help further support these
waves and with model soundings showing a decent amount of dry air in
the low levels, have only slight chance PoPs in across far northern
and far northeast Kansas Saturday morning with dry conditions by the
afternoon as the associated vort max lifts to the northeast. With
the above-mentioned surface pattern in place, southerly surface
winds should boost high temperatures into the upper 70s/low 80s.
Have gone with a dry forecast Saturday afternoon through Sunday
before the next system moves into the region, which will be the
beginning of a wet stretch of weather that looks to extend through
the latter part of next week. Models show the surface low advancing
eastward toward the CWA on Sunday, resulting in an increased
pressure gradient, breezy southerly winds, and thus good warm air
advection that should support the warmest temperatures of the week
with highs reaching into the low/mid 80s. Precipitation chances will
increase Sunday night through Monday as a cold front slowly sags
southeastward across the CWA. However, models show the front
stalling out over the southern portions of the forecast area and
pivoting over the area before lifting northward as a warm front to
just north of the KS/NE border on Tuesday. As a result, have chance
to likely PoPs for thunderstorms from Sunday night through Monday
night. Even though the cap looks to significantly weaken through the
day on Monday and the amount of available instability is modest,
wind shear looks to be fairly weak across the region, thus limiting
the potential for strong storms. With the warm front lifting into
Nebraska, ECMWF/GEM actually keep Tuesday predominantly dry while
the GFS tries to hold on to some scattered precipitation chances, so
have lowered PoPs. However, thunderstorm chances increase once again
by Tuesday night as a mid-level trough becomes negatively tilted and
begins to lift northward into the central U.S. This approaching
trough will not only provide additional forcing to support
thunderstorm development, but also push another area of surface low
pressure into the area by mid week. However, there are still model
discrepancies in the evolution of the mid-level trough as it lifts
northward and in the timing of the passage of the cold front, which
should track eastward across the area sometime during the latter
part of the week. As a result, there is uncertainty still with when
this system will exit the region. At this time, have chance to
likely PoPs in from Tuesday night through Thursday night. The best
potential for some more-organized storms looks to be during the mid
to late week period in which the combination of the surface low
pressure system and mid-level trough should provide decent forcing
along with decent instability and some slightly improved wind shear.
At this time, temperatures next week look to be fairly steady with
highs in the 70s and lows in the 50s to low 60s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Friday Night)
Issued at 1148 PM CDT THU APR 30 2015
Expect VFR conditions through the next 24 hours. Light east to
southeast winds this morning will become southerly after 14Z, but
will remain below 10 KTS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GDP
LONG TERM...Hennecke
AVIATION...Gargan
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
110 AM EDT Fri May 1 2015
...Updated Aviation Discussion...
.SHORT TERM (Now through Friday Night)...
Issued at 305 PM EDT Thu Apr 30 2015
Unseasonably cold mid-level low continues to move southward and was
centered over west-central IN at mid-afternoon. The low will
propagate over central and eastern KY this evening. As expected,
cold mid-level temperatures combined with modest low-level heating
have steepened lapse rates and facilitated development of scattered
to numerous showers and a few thunderstorms. A few cells have
produced pea size hail, brief wind gusts up to 40 mph, and some
lightning strikes.
Currently, radar data shows better precipitation coverage over
east-central KY including the Lexington area, and approaching the
eastern half of south-central IN from the north. Latest HRRR model
reflectivity forecast captures these areas reasonably well. It
maintains the southern IN cells, moving them south-southeast into
north-central and east-central KY late this afternoon. Other pop up
cells could occur elsewhere as well. Thus, will maintain highest
coverage/percentage of precipitation east of Interstate 65,
especially over east-central KY.
Rainfall intensity and coverage will slowly diminish this evening
with loss of daytime heating and as the upper low moves eastward.
Overnight, dry weather is expected with some clouds remaining over
the east, with fewer clouds over western parts of our forecast area.
There could be patchy fog near daybreak over parts of east-central
KY. It will be chilly, with lows Friday morning in the upper 30s and
lower 40s in many areas.
On Friday, the mid-level low will continue pulling eastward away
from our area. There could be some residual clouds over the east
half of our forecast area, but dry weather is expected. Temperatures
will begin a warming trend that will last through the weekend and
into next week. Expect highs Friday afternoon in the mid 60s to
lower 70s.
.LONG TERM (Saturday through Thursday)...
Issued at 315 PM EDT Thu Apr 30 2015
Saturday - Saturday Night...
NW flow aloft will dominate the pattern, meanwhile surface high
pressure will be in place. Models have been consistent now for the
past several runs in depicting a shortwave embedded in the flow
traversing the area on Saturday. Will continue to keep the forecast
dry as this feature looks starved of moisture. Instead, will depict
an increase in cloud cover through the afternoon, although still
expect partly sunny skies. With plenty of peaks at the sun, will
call for temps mostly in the mid 70s. A few spots that see more
clouds may stay in the low 70s.
Dry conditions will continue into Saturday night where weak and
progressive upper ridging slides over the Ohio River Valley.
Meanwhile, surface high pressure remains at the surface. Given good
radiational cooling conditions, lows will still slide into the upper
40s and low 50s.
Sunday - Thursday...
Low amplitude NW flow aloft will transition to upper ridging over
the CWA to end the weekend and start the new work week. This ridge
is then expected to hold over the area through the end of the week.
A frontal boundary that looks to stall nearly parallel to the upper
flow should stay well to the north across the southern Great Lakes.
This pattern will result in continued dry conditions and
temperatures rising above normal for this time of year. Can`t rule
out an extremely isolated shower or t-storm at some point through
the week, however lack of a trigger and mid level subsidence
inversion is enough to keep a dry forecast going.
Have nudged temperatures up around MEX guidance given the warmer
pattern, and wouldn`t be surprised if they end up a couple of
degrees warmer. This will result in forecast temperatures more
solidly in the low and mid 80s Tue-Thur. Will go with upper 70s to
around 80 for Sunday, and around 80 for Monday. Lows each night
should mostly be in the 50s, with the usual warm spots likely around
60.
&&
.AVIATION (06Z TAF Update)...
Updated at 109 AM EDT Fri May 1 2015
High pressure building in from the north should keep the TAFs VFR
during this forecast period. There`s a small chance of some MVFR BR
at BWG early this morning, but right now it looks like dew point
depressions will remain large enough to warrant a VFR TAF. Also,
there is a small chance of an MVFR ceiling at LEX in the hours
before and after sunrise, but it`s looking like the best chances for
low ceilings will stay just east of the terminal. Lastly, there is
some concern for MVFR BR at LEX, but with expected cloud cover
and continued north wind, will not include it in the TAF at this
time.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........TWF
Long Term.........BJS
Aviation..........13
AREA FORECAST DISCUSSION
NWS DULUTH MN
331 AM CDT FRI MAY 1 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 331 AM CDT FRI MAY 1 2015
A TROUGH AND SHORTWAVE WERE MOVING INTO WESTERN MINNESOTA THIS
MORNING WITH AN AREA OF RAIN OCCURRING AHEAD OF THESE FEATURES.
AS OF 0830Z...RAIN STRETCHED FROM NEAR KINL TO KDTL AND SOUTH INTO
SOUTHWEST MINNESOTA. THERE WERE ALSO A FEW SHOWERS FURTHER WEST
TOWARD KABR. THE MODELS REMAIN IN DECENT AGREEMENT THAT THIS AREA
OF RAIN WILL BECOME LESS ORGANIZED AND DIMINISH AS IT MOVES
FURTHER EAST INTO DRIER AIR AND AWAY FROM THE BETTER FORCING. OUR
POPS REFLECT THIS TREND WITH LIKELY WORDING OVER THE WEST
EARLY...AND A SLIGHT CHANCE FAR EAST. ONE CHANGE WE DID MAKE
WAS TO ADD A CHANCE FOR SHOWERS TO PORTIONS OF EASTERN MINNESOTA
AND NORTHWEST WISCONSIN THIS AFTERNOON INTO THE EVENING. THE LOW
LEVEL TROUGH WILL BE A FOCUS AND ACT ON SOME LOW STABILITY AIR
WHICH MAY SET OFF A FEW LIGHT SHOWERS. THE MODELS WERE INDICATING
THIS CHANCE WITH EARLIER RUNS...AND CONTINUE TO DO SO. SEVERAL OF
THE HIGH RESOLUTION MODELS SHOW THIS AS WELL. WE HAVE HIGHS IN THE
LOWER SIXTIES TO LOWER SEVENTIES ACROSS THE CWA...WARMEST OVER THE
WEST WHERE MORE SUN IS EXPECTED.
CLOUDS WILL DIMINISH TONIGHT AND THERE MAY BE SOME PATCHY FOG IN
SPOTS INTO EARLY SATURDAY MORNING.
SATURDAY WILL BE A WARM DAY FOR MOST AREAS WITH HIGHS FROM THE MID
SEVENTIES TO AROUND 80. THERE IS A CONCERN THAT WE MAY BE TOO WARM
AROUND LAKE SUPERIOR. THERE MAY BE AN ONSHORE WIND ALONG THE SOUTH
SHORE INTO THE TWIN PORTS/TWO HARBORS AREAS THROUGH THE
MORNING...BUT MOST OF THE GUIDANCE SUGGESTS WINDS WILL TURN TO
SOUTHWEST. IF THIS HAPPENS...IT WILL WARM THE AREAS
MENTIONED...BUT KEEP THE NORTH SHORE COOLER THROUGH THE DAY. LOW
HUMIDITY AND SOME AFTERNOON SOUTHERLY GUSTS WILL MEAN FIRE WEATHER
VALUES WILL APPROACH CRITICAL CONDITIONS...ESPECIALLY FROM THE
BRAINERD LAKES REGION NORTH THROUGH INTERNATIONAL FALLS. THE RAIN
TODAY WILL DO LITTLE TO MOISTEN FUELS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 331 AM CDT FRI MAY 1 2015
FORECAST REMAINS WARM AND UNSETTLED INTO NEXT WEEK.
A COLD FRONT ASSOCIATED WITH A H85 TROUGH IS FCST TO SWEEP ACROSS
NORTH CENTRAL MN SUNDAY MORNING...REACHING THE WESTERN TIP OF LAKE
SUPERIOR AND NW WISCONSIN DURING THE AFTERNOON/EARLY EVENING HRS.
ATTM...THERE IS SUFFICIENT SHEAR/INSTABILITY AND MOISTURE TO SUPPORT
THUNDER AND EVEN A FEW STRONG STORMS WITH THE FRONTAL PASSAGE
SUNDAY. LOCATIONS IN NRN WISCONSIN WILL HAVE A THREAT FOR AN
ISOLATED SEVERE STORMS WITH LARGE HAIL...AS LATEST NAM BUFR
SOUNDINGS SUGGEST PWATS CLIMB IN EXCESS OF AN INCH AND SFC BASED
CAPE VALUES ARE IN EXCESS OF 2000 J/KG SUNDAY AFTERNOON.
SFC HIGH PRESSURE RETURNS SUNDAY NIGHT/MONDAY AS COLD AIR ALOFT
SINKS OVER THE NORTHLAND. MODELS ARE IN GOOD AGREEMENT THAT H85
TEMPERATURES COMMENCE IN THE MID TEENS SUNDAY MORNING...FALLING INTO
THE SINGLE DIGITS BY MONDAY MORNING. ALTHOUGH HIGH TEMPS WILL BE
COOLER MONDAY...IN THE 50S TO 60S...THE DRY AIR MASS AND STEEP LAPSE
RATES WILL PROMOTE DEEP MIXING AND LOW RH VALUES AROUND 20 PERCENT.
WINDS WILL GENERALLY BE OUT OF THE NORTHWEST TO NORTH WITH AFTERNOON
GUSTS AROUND 15 MPH.
FOCUS TURNS TO LONG WAVE TROUGH IN THE WESTERN CONUS THAT EJECTS A
SHORT WAVE INTO THE UPPER PLAINS MID-WEEK. THE WAVE WILL BRING GUSTY
SOUTHERLY WINDS /EXCEPT EAST NEAR LAKE SUPERIOR/ AND INCREASING
MOISTURE TO THE THE REGION. LONG RANGE MODELS SHOW SIGNIFICANT
DIFFERENCES IN THE UPPER LEVEL SPLIT FLOW BEYOND WEDNESDAY...WITH A
TREND TOWARDS A WET PERIOD THROUGH THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1259 AM CDT FRI MAY 1 2015
VFR CONDITIONS EXPECTED AT ALL TERMINALS EXCEPT FOR KBRD BETWEEN
12Z-15Z. MVFR CIGS EXPECTED DURING THIS TIMEFRAME...AS -RA DEVELOPS
DUE TO A COLD FRONT PASSING THROUGH. KINL MAY SEE MVFR CIGS FROM
TIME TO TIME BETWEEN 10Z AND 15Z...BUT WAS NOT CONFIDENT ENOUGH
DUE TO DRIER AIR IN THE LOWER LEVELS.
LAST SEVERAL HRRR RUNS SHOW PRECIPITATION DIMINISH IN
COVERAGE AS THE FRONT WEAKENS WHILE MOVING THROUGH. AS A RESULT
ONLY KEPT VCSH FOR KDLH AND KHIB DUE TO THE DRY AIR AND WEAKENING
FRONT. BEHIND THE FRONT CONDITIONS WILL IMPROVE AS HIGH PRESSURE
BUILDS IN.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 67 44 75 49 / 50 20 0 20
INL 70 45 81 49 / 50 10 10 20
BRD 69 48 81 53 / 70 10 0 30
HYR 65 43 80 53 / 20 20 0 10
ASX 69 41 77 51 / 20 20 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...GRANING
AVIATION...GRANING/WL
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1259 AM CDT FRI MAY 1 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 341 PM CDT THU APR 30 2015
A WEAK COLD FRONT/TROUGH AXIS WILL MOVE THROUGH THE FORECAST AREA
TONIGHT AND EARLY FRIDAY...DRAGGING SOME RAIN SHOWERS WITH IT. THE
FRONTOGENESIS IS FAIRLY DECENT NOW OVER NORTH DAKOTA WHERE THERE IS
A NICE FIELD OF NUMEROUS SHOWERS...BUT WEAKENS TONIGHT AND FRIDAY AS
THE FRONT MOVES EAST. TOGETHER WITH THE LARGE AMOUNT OF DRY AIR TO
BE OVERCOME AT THE LOW LEVELS...THIS IS GOING TO LIMIT OUR
PRECIPITATION AMOUNTS. THE WESTERN CWA HAS THE BEST POTENTIAL FOR
GETTING FROM ONE TO TWO TENTHS OF AN INCH...BUT SOME LOCATIONS
FARTHER EAST MAY ONLY GET A TRACE. TEMPERATURES TOMORROW WILL BE
LIMITED BY THE CLOUD COVER AND PRECIPITATION...BUT WITH THE STRONG
WARM AIR ADVECTION GOING ON WE SHOULD STILL GET BACK INTO THE MID
60S TO NEAR 70. LOWS TONIGHT WILL BE BACK IN THE MID 30S TO MID 40S
MOST LOCATIONS...THOUGH SOME PLACES ALONG THE NORTH SHORE MAY DIP TO
AROUND FREEZING.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 341 PM CDT THU APR 30 2015
A MILD AND ACTIVE WEATHER PATTERN THROUGH THE WEEKEND AND THROUGH
MUCH OF NEXT WEEK.
ON THE SYNOPTIC SCALE MID/UPPER LEVEL FLOW WILL BE GENERALLY
WEST-SOUTHWEST THROUGH THE WEEKEND WITH SOUTHWESTERLY FLOW AT LOW
LEVELS BRINGING IN MUCH WARMER AIR...ALLOWING HIGHS TO REACH THE MID
TO UPPER 70S ON SATURDAY AND SUNDAY. A COLD FRONT WILL MOVE THROUGH
ON SATURDAY NIGHT INTO SUNDAY WHICH WILL BRING CLOUDS AND A CHANCE
FOR SHOWERS AND ISOLATED THUNDERSTORMS. MOST OF THE RAIN WILL FALL
SUNDAY AFTERNOON INTO THE EVENING ACROSS NORTHWEST WISCONSIN...WITH
THE POTENTIAL FOR UP TO A HALF INCH OR MORE IN SOME LOCATIONS FROM
THE SAINT CROIX RIVER VALLEY EAST TO SOUTHERN PORTIONS OF THE
CHEQUAMEGON NATIONAL FOREST.
HIGH PRESSURE MOVES IN BEHIND THE COLD FRONT WITH 850MB TEMPS
PLUNGING FROM 12-14C SATURDAY AFTERNOON TO 3-5C BY MONDAY
MORNING...THOUGH WITH CLEARING SKIES AS HIGH PRESSURE MOVES IN AND
DEEP MIXING TAKING PLACE EXPECT HIGHS IN THE 60S MONDAY AND
APPROACHING 70 ON TUESDAY. IT WILL ALSO BE DRY WITH MINIMUM
AFTERNOON RELATIVE HUMIDITY VALUES IN THE 25 TO 35 PERCENT
RANGE...WITH LIGHT AND VARIABLE WINDS AS HIGH PRESSURE MOVES ACROSS
THE UPPER GREAT LAKES. AN UPPER LEVEL LOW WILL MOVE ACROSS THE FOUR
CORNERS REGION ON TUESDAY AND BE EJECTED NORTH/NORTHEAST INTO THE
PLAINS AND UPPER MIDWEST LATE WEDNESDAY INTO THURSDAY...WITH A
STREAM OF MOIST GULF AIR AHEAD OF IT RAISING PWAT VALUES TO WELL
ABOVE NORMAL. THERE IS THE POTENTIAL FOR MODERATE TO HEAVY RAINFALL
WITH THIS PATTERN THROUGH THE LATTER PORTION OF THE WORK WEEK.
TEMPERATURES WILL GENERALLY BE SEASONABLE TO ABOVE NORMAL...WITH
HIGHS IN THE 60S TO NEAR 70 ON WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1259 AM CDT FRI MAY 1 2015
VFR CONDITIONS EXPECTED AT ALL TERMINALS EXCEPT FOR KBRD BETWEEN
12Z-15Z. MVFR CIGS EXPECTED DURING THIS TIMEFRAME...AS -RA DEVELOPS
DUE TO A COLD FRONT PASSING THROUGH. KINL MAY SEE MVFR CIGS FROM
TIME TO TIME BETWEEN 10Z AND 15Z...BUT WAS NOT CONFIDENT ENOUGH
DUE TO DRIER AIR IN THE LOWER LEVELS.
LAST SEVERAL HRRR RUNS SHOW PRECIPITATION DIMINISH IN
COVERAGE AS THE FRONT WEAKENS WHILE MOVING THROUGH. AS A RESULT
ONLY KEPT VCSH FOR KDLH AND KHIB DUE TO THE DRY AIR AND WEAKENING
FRONT. BEHIND THE FRONT CONDITIONS WILL IMPROVE AS HIGH PRESSURE
BUILDS IN.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 45 73 50 72 / 0 0 20 50
INL 40 78 49 70 / 0 10 20 20
BRD 45 78 54 74 / 0 0 30 50
HYR 44 76 53 77 / 10 0 10 40
ASX 42 75 51 76 / 10 0 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...LE
LONG TERM...LE
AVIATION...GRANING/WL
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
343 AM CDT Fri May 1 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 322 AM CDT Fri May 1 2015
Dry and tranquil weather is expected today as weak height rises
commence aloft with the departure of the mid Atlantic upper
low/trof and eastward shift in the upper ridge currently centered
in the southern Rockies. The surface high centered in northern IL
will only meander southeast. This will translate to a nice day with
light winds, lots of morning sun, and some thin high clouds in the
afternoon. Temperatures will be seasonable and forecast highs are
a blend of the warmer MAV MOS and RAP 2m temps.
Glass
.LONG TERM: (Tonight through Thursday)
Issued at 322 AM CDT Fri May 1 2015
The tail end of a weak short wave passing to the north will bring
an increase in cloudiness overnight. The persistent and ever so
slowly retreating low level anticyclone will limit low level
moisture transport/return to the Plains into Iowa. That said the
increase in mid level moisture and warm advection may be
sufficient for spotty showers across parts of northeast MO. While
southerly flow and WAA becomes better established Saturday and
Saturday night in the wake of the slow retreating anticyclone,
trajectories are poor for low level moisture return. Once again
the main impetus for pops will be mid level moisture, WAA,
glancing influence from passing disturbances, and some marginal
elevated instability leading to slight chance pops across parts of
northeast MO and west central IL. The ridge aloft builds east into
the OH Valley on Sunday and the threat of precipitation takes a
decided northward shift to the vicinity of a cold front moving
through the northern Plains and upper MS Valley. The threat of
showers and thunderstorms will progressively increase late Sunday
night into Monday night as the cold front approaches Sunday night
and then becomes quasi-stationary across northern MO and west
central IL Monday into Monday night. By this time the low level
moisture and hence instability is much improved owing to
persistent s-sw lower trop flow and presence of steep mid level
lapse rates. This front then moves back north by midweek leading
to a diminished precipitation threat, which increases again late
week with the development of southwest flow aloft and accompanying
disturbances and continued low level moisture transport.
Temperatures will be above average beginning this weekend and
continuing all of next week.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1143 PM CDT Thu Apr 30 2015
Large dome of high pressure over the upper Great Lakes and upper
Mississippi Valley will be building south, maintaining a firm
control over the region`s weather heading into the start of the weekend.
VFR conditions will continue at all TAF locations, with little in the way
of cloudiness and light winds.
Specifics for KSTL: VFR conditions are forecast through Friday,
with only a bit of cirrus from time to time along with light
surface winds.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
345 AM CDT FRI MAY 1 2015
.SHORT TERM...(TODAY)
ISSUED AT 341 AM CDT FRI MAY 1 2015
PCPN CHANCES/PCPN COVERAGE AND TEMPERATURES WILL PROVIDE THE MAIN
FORECAST CHALLENGES FOR THE TODAY PERIOD.
REGIONAL RADAR LOOP EARLY THIS MORNING SHOWED SHOWERS AND A FEW
EMBEDDED THUNDERSTORMS OCCURRING IN ASSOCIATION WITH A WEAK COLD
FRONT MOVING EASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS. THIS
FRONT SHOULD STALL OUT AND THEN WASH OUT THIS EVENING. LATEST SHORT
RANGE HIGH RESOLUTION MODELS ARE IN DECENT AGREEMENT SHOWING SOME
SCATTERED AND MAINLY LIGHT PCPN MOVING ACROSS THE FORECAST AREA THIS
MORNING. 06Z RAP SEEMED TO HAVE A FAIRLY GOOD HANDLE ON THE PATTERN.
LOOK FOR HIGHS MOSTLY IN THE LOWER AND MID 70S BUT A FEW LOCATIONS
IN WEST CENTRAL IOWA MAY ONLY REACH NEAR 70.
.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 341 AM CDT FRI MAY 1 2015
FOCUS FOR POSSIBLE PCPN SHIFTS TO THE SRN CWA TONIGHT AND SATURDAY
MORNING WHERE 310K UPGLIDE AND LOW COND PRES DEF WILL BE MOST
PREVALENT.
NEXT ROUND OF PCPN ASSOCIATED WITH A COLD FRONT DROPPING THRU THE
DAKOTAS/UPPER MID WEST SATURDAY NIGHT THE INTO THE CWA ON SUNDAY.
MODELS HOLD OFF DEVELOPMENT UNTIL AFTN WHEN ENVIRONMENT BECOMES
ADEQUATELY UNSTABLE...THEN INCREASES IN AREAL COVERAGE AND
INTENSITY SUNDAY NIGHT IN RESPONSE TO STRENGTHENING BNDRY LYR
MOISTURE CONVERGENCE. WITH RELATIVELY HIGH CONCENTRATION OF
ENVIRONMENTAL MOISTURE AND PERSISTENT FORCING...CONDITIONS WILL
BE FAVORABLE FOR SOME LOCATIONS TO SEE RAINFALL AMOUNTS OF HALF
AND INCH OR SO.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI MAY 1 2015
SFC BNDRY AT THIS POINT PROGGED TO BECOME NEARLY STATIONARY MONDAY
MORNING THRU TUESDAY MORNING. PERSISTENT INFLUX OF GULF MOISTURE
COUPLED WITH MOIST BNDRY LYR CONVERGENCE/INSTABILITY AXIS SITUATED
OVER THE CWA WOULD SUGGEST CONDITIONS WILL AGAIN BE FAVORABLE FOR
SIGNIFICANT RAINFALL ACCUMULATIONS. TUESDAY AFTN THRU THURSDAY
NIGHT PCPN ACCUMULATIONS BEING DRIVEN BY EXTENDED PERIOD OF 305K
UPGLIDE/PRESIDENT LLVL MOISTURE ADVECTION. OTHERWISE...METEOGRAMS
STILL SHOWING MODERATE COOL NEXT WEEK IN LIGHT OF SFC BNDRY MOVING
IN.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1144 PM CDT THU APR 30 2015
FORECAST REASONING REMAINS FROM PREVIOUS TAF CYCLE. VFR CONDITIONS
ARE EXPECTED TO CONTINUE. ISOLATED TO SCATTERED SHOWERS AND A
POSSIBLE RUMBLE OF THUNDER SHOULD MOVE INTO THE AREA FROM LATE
OVERNIGHT/EARLY MORNING THROUGH THE AFTERNOON...BUT COVERAGE
CONCERNS PRECLUDES MENTION AT THIS TIME. SOUTHEAST WINDS WILL
BECOME SOUTHWESTERLY...WITH SPEEDS AT OR BELOW 10KT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
TONIGHT...BCM
SHORT TERM...DEE
LONG TERM...DEE
AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
147 AM EDT FRI MAY 1 2015
.SYNOPSIS...
THE PASSAGE OF A STRONG UPPER LEVEL DISTURBANCE LATE IN THE DAY
WILL FINALLY KICK LOW PRESSURE ALONG THE NORTH CAROLINA COAST
WELL OFFSHORE...ENDING THE RISK FOR SHOWERS AND THUNDERSTORMS.
HIGH PRESSURE WILL BUILD ACROSS THE AREA FOR THE WEEKEND AND INTO
THE FIRST PART OF NEXT WEEK. THE DRY WEATHER AND RETURNING
SUNSHINE WILL ALLOW TEMPERATURES TO RETURN TO SEASONABLE LEVELS BY
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1015 PM THURSDAY...SHOWERS BREAKING OUT ACROSS THE FORECAST
AREA AS AN UPPER DISTURBANCE DROPS SE ACROSS THE CAROLINAS. SOME
LIGHTNING BEING DETECTED OVER PENDER COUNTY BUT OTHERWISE WE ARE
SEEING JUST ISOLATED TO WIDELY SCATTERED SHOWER ACTIVITY. OTHER
THAN THE LIGHTNING THIS ACTIVITY IS FAIRLY BENIGN AND WILL
CONTINUE ON AND OFF THROUGH THE EVENING HOURS. FORECAST IN GOOD
SHAPE...PREVIOUS DISCUSSION FOLLOWS:
LOW PRESSURE CENTERED SOUTH OF CAPE HATTERAS SHOULD SLOW TONIGHT
AS A POWERFUL UPPER LEVEL DISTURBANCE DIVES SOUTHWARD FROM INDIANA
INTO NORTH CAROLINA. ALTHOUGH LOW- LEVEL BAROCLINICITY IS VERY
WEAK...A FAVORABLY ORIENTED JET STREAK OFFSHORE PLUS INCOMING
VORTICITY WITH THE DISTURBANCE SHOULD LEAD TO SLOWLY FALLING
PRESSURES OFFSHORE.
AWAY FROM EXTREME EASTERN NC (INCLUDING WILMINGTON) THERE HAS BEEN
PLENTY OF SUNSHINE TODAY. TEMPERATURES RISING INTO THE 70S PLUS
RATHER COOL TEMPERATURES ALOFT HAVE HELPED GENERATE SURFACE-BASED
CAPE AS LARGE AS 500 J/KG ALONG AND WEST OF I-95. SO FAR THIS HAS
RESULTED IN AN EXPANSIVE CUMULUS FIELD ACROSS WESTERN NC PLUS A
SMATTERING OF SHOWERS. AS 800-600 MB TEMPERATURES FALL FURTHER THIS
EVENING AND THE FIRST OF SEVERAL UPPER DISTURBANCES ARRIVES FROM THE
WEST...THE POTENTIAL FOR SHOWERS WILL EXPAND ACROSS SOUTHEASTERN
NORTH CAROLINA AND NORTHERN PORTIONS OF THE PEE DEE REGION. I HAVE
DECIDED NOT TO INCLUDE THUNDER IN THE FORECAST AS IT APPEARS AN
INVERSION BETWEEN 500-600 MB SHOULD BE SUFFICIENTLY STRONG TO CAP
OFF UPDRAFTS BEFORE THEY BECOME COLD ENOUGH ALOFT. 12Z MODELS HAVE
BACKED OFF A LITTLE COMPARED TO THEIR 00Z/06Z COUNTERPARTS WITH THE
SOUTHERN EXTENT OF PRECIPITATION...AND THIS TREND IS ECHOED BY THE
LAST FEW HRRR RUNS AS WELL.
BY LATE TONIGHT THE MAIN UPPER LOW WILL WOBBLE INTO CENTRAL NORTH
CAROLINA. NEAR AND NORTH OF THE LOW IS WHERE UNSTABLE CONDITIONS
SHOULD CONTINUE OVERNIGHT DUE TO COLD AIR ALOFT. OUR FORECAST AREA
SHOULD LARGELY REMAIN SOUTH OF THE INSTABILITY...SO ASIDE FROM
MAINTAINING 30-40 PERCENT POPS ACROSS LUMBERTON-ELIZABETHTOWN-BURGAW
I HAVE CUT POPS TO 10-20 POPS OVERNIGHT...WITH LOWS GENERALLY IN THE
LOWER 50S EXCEPT MID 50S AT THE BEACHES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
AS OF 300 PM THURSDAY...A STRONG UPPER LOW WILL CUT BY TO OUR
NORTH ON FRIDAY. EVEN SO WE SHOULD SEE VERY STRONG PVA AND HEIGHT
FALLS LOCALLY AND SOME LIGHT SHOWERS SEEM LIKELY OVER NORTHERN
ZONES. STILL TOUGH TO RULE OUT THUNDER WITH UPWARDS OF 600J/KG OF
CAPE DEVELOPING. SOME OF THIS INSTABILITY MAY GO SUFFICIENTLY INTO
THE HAIL GROWTH LAYER FOR SOME PEA SIZED HAIL TO REACH THE GROUND
UNDERNEATH THE DEEPER CONVECTIVE CELLS. CLOUD COVER WILL MEANWHILE
BRING ONE LAST DAY OF CONSIDERABLY COOL TEMPS WITH HIGHS STUCK IN
THE 60S. DRY AIR MOVES IN FRIDAY NIGHT INTO SATURDAY. THERE IS
HOWEVER ONE TRAILING VORT AND WRAPAROUND MOISTURE ON SATURDAY AND
SOME GUIDANCE HINTING AT PRECIP OVER CAPE FEAR/COASTAL NC ZONES.
FEEL IF ANYTHING AT ALL WILL BE JUST NON-MEASURABLE AND HAVE KEPT
THE FORECAST DRY AT THIS TIME. THE DECREASED CLOUD COVER WILL
ALLOW FOR A NICE BUMP IN TEMPERATURES COME SATURDAY BUT THE
NORTHERLY FLOW COMPONENT THROUGH A DEEP LAYER WILL STILL KEEP US A
TAD BELOW CLIMO.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...BERMUDA HIGH AND MID LEVEL RIDGE BUILDING
OVER THE SOUTHEAST WILL KEEP THE REGION DRY DURING THE PERIOD WITH
TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO. AS FAR AS THE TROPICAL
WAVE/LOW COMBO EMERGING FROM THE BAHAMAS NEXT WEEK GOES THE LATEST
MEDIUM RANGE GUIDANCE HAS FALLEN OUT OF FAVOR WITH THIS SCENARIOS.
NEARLY ALL OF THE GUIDANCE (INCLUDING THE ENSEMBLES) NOW SHOW A
SHEARED OUT SURFACE WAVE MOVING EAST-NORTHEAST...REMAINING WELL
SOUTHEAST OF THE COAST. LATER IN THE PERIOD CANNOT RULE OUT AN
ISOLATED SEA BREEZE SHOWER AS LOW LEVEL MOISTURE INCREASES BUT
COVERAGE WILL BE QUITE LIMITED AND DOES NOT WARRANT INCLUSION OF
POP GREATER THAN 15 AT THIS TIME.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...SHOWERS WILL TEND TO INCREASE EARLY THIS MORNING MAINLY
KILM TO KLBT AS A STRONG UPPER LOW APPROACHES. THERE IS MODERATE
CONFIDENCE IFR WILL DEVELOP AT KLBT/KILM/KCRE. IFR IS POSSIBLE AT
KMYR AND KFLO AROUND SUNRISE...BUT CONFIDENCE IS HIGHER CIGS WILL
BE MVFR WITH ANY IFR OF A SHORT TEMPO DURATION. GENERALLY CIGS WILL
IMPROVE TO MVFR THEN VFR DURING THE MORNING HOURS AS WINDS BECOME
NW 10-12 KT. SHOWERS WILL CONTINUE...BUT STILL MOST LIKELY NEAR KILM.
VFR EXPECTED IN THE AFTERNOON...BUT MVFR CIGS WILL BECOME POSSIBLE
AGAIN WITH BEST CONFIDENCE OF OCCURRENCE AT KILM AND KLBT. WINDS
WILL BE NW-N FRIDAY...GUSTING TO 20-25 KT BY AFTERNOON. WINDS
DECREASE AFTER 23-00Z AS SKIES BECOME SCT.
EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 PM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
LOW PRESSURE HAS MOVED SOUTH OF HATTERAS THIS AFTERNOON BUT
SHOULD SLOW TONIGHT AS A STRONG UPPER LEVEL DISTURBANCE APPROACHES
FROM THE WEST. THIS DISTURBANCE WILL CREATE A ZONE OF WEAKENED
PRESSURE GRADIENT ACROSS EASTERN NORTH CAROLINA TONIGHT...WHILE TO
THE SOUTH ACROSS SOUTH CAROLINA THE GRADIENT SHOULD GRADUALLY
TIGHTEN WITH INCREASING WESTERLY WINDS EXPECTED. BY DAYBREAK WINDS
JUST EAST OF WINYAH BAY/GEORGETOWN COULD REACH 15-20 KT. THE
VARIOUS COMPUTER MODELS HAVE DIFFERING POSITIONS OF WHERE THE
BOUNDARY BETWEEN THESE STRONGER WEST WINDS AND LIGHTER NORTH WINDS
CLOSER TO THE LOW WILL SET UP...AND I HAVE FOLLOWED THE 12Z GFS AS
A GUIDE TONIGHT.
SEAS CURRENTLY RANGE FROM 2-3 FEET INSIDE 20 MILES OF SHORE...TO 4
FEET OUT AT THE FRYING PAN SHOALS BUOY. SEAS MAY SUBSIDE A BIT THIS
EVENING BUT SHOULD INCREASE AGAIN OVERNIGHT...ESPECIALLY SOUTH OF
CAPE FEAR...DUE TO THE INCREASING WIND SPEEDS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 PM THURSDAY...LOW PRESSURE OFF CAPE HATTERAS WILL BE
SLOW TO MOVE ON FRIDAY, ENERGIZED IN PART BY A STRONG LOW IN THE
MID LEVELS. THIS FEATURE WILL STRENGTHEN VERTICAL MIXING MORE THAN
THE ACTUAL SURFACE PRESSURE GRADIENT, POSSIBLY ENOUGH FOR SOME
ADVISORY-WORTHY 25KT WINDS OVER MAINLY JUST OUR NORTHERNMOST ZONE-
MAINLY FRIDAY NIGHT. ALL MODELS ARE NOT CONVINCED OF THIS AND
THERE IS STILL A BIT OF TIME TO IRON OUT THE UNCERTAINTY SO ONE
WILL NOT BE RAISED AT THIS TIME. THE LOW WILL BE GRADUALLY PULLING
AWAY TO THE NORTHEAST ON SATURDAY. WINDS LOCALLY WILL REMAIN N TO
NW AND SLOWLY SUBSIDE. THERE MAY EVEN BE A BIT OF BACKSWELL FROM
THE OFFSHORE STORM AS IT GROWS A BIT LARGER IN SIZE.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 300 PM THURSDAY...SURFACE HIGH MOVING OFF THE COAST SUN
MORNING WILL SETUP NEAR BERMUDA SUN EVENING AND REMAIN IN PLACE
THROUGH THE END OF THE PERIOD. LIGHT AND VARIABLE WINDS ON
SUN...WITH SEA BREEZE DOMINATING NEAR SHORE FLOW...WILL BECOME
SOUTHEAST TO SOUTH MON AND TUE. GRADIENT WILL REMAIN ON THE WEAK
SIDE WITH SPEEDS GENERALLY 10 KT OR LESS. DAILY SEA BREEZE WILL
RESULT IN A SLIGHT BUMP IN SPEEDS NEAR SHORE IN THE AFTERNOON.
SEAS AROUND 2 FT WILL BE MAINTAINED THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK/TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...RJD/MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
259 AM CDT FRI MAY 1 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 259 AM CDT FRI MAY 1 2015
PRECIP THIS MORNING AND AGAIN SATURDAY AFTERNOON WILL BE THE MAIN
CONCERNS...ALONG WITH WIND TODAY FOR FIRE WEATHER.
NEAR ZONAL FLOW ALOFT SETS UP AS THE UPPER RIDGE PUSHES OFF TO THE
EAST. THE SFC TROUGH OVER THE CWA THIS MORNING WILL MOVE
SOUTHEASTWARD TODAY AND WASH OUT...LEAVING RELATIVELY LIGHTER WEST
WINDS. RAINFALL OVER THE EASTERN COUNTIES WILL MOVE OUT OF THE
AREA SHORTLY AFTER 12Z. THERE WILL BE A PERIOD BEFORE THE WESTERLY
WINDS START TO PICK UP BUT AFTER CLOUDS CLEAR OUT. WITH RECENT
RAINFALL SOME RADIATION FOG HAS DEVELOPED IN THE NORTHWESTERN CWA.
IT IS SOMEWHAT PATCHY...WITH KDVL SHOWING 10SM RIGHT NOW. EXPANDED
THE FOG MENTION IN THE GRIDS BUT GIVEN THE PATCHY NATURE WILL JUST
KEEP AN EYE ON WEB CAMS AND OBS FOR NOW AND HOLD OFF ON ANY DENSE
FOG ADVISORIES.
WITH WESTERLY WINDS TODAY WE SHOULD DRY OUT NICELY BY AFTERNOON
AND TEMPS WILL AGAIN WARM INTO THE 70S ALTHOUGH NOT AS WARM AS
YESTERDAY. DRY CONDITIONS WILL AGAIN BE AN ISSUE BUT WINDS WILL BE
MUCH LESS TODAY...AROUND 10 KTS IN THE VALLEY AND EASTWARD...WITH
MAX OF LESS THAN 15 KTS IN THE NORTHWESTERN COUNTIES. THERE SHOULD
BE A DEEP ADIABATIC LAYER...BUT MODEL SOUNDINGS FOR KDVL SHOW AT
MOST A 10 TO 15 KTS AT THE TOP...SO THINK THAT GUSTINESS WILL NOT
BE TOO HIGH. THE SOUTH WINDS WILL CONTINUE TO SLOWLY RAMP UP INTO
TONIGHT AS SFC LOW PRESSURE DEVELOPS ALONG THE
SASKATCHEWAN/MANITOBA BORDER. THE WINDS SHOULD HELP TEMPS FRIDAY
NIGHT TO STAY IN THE UPPER 40S TO NEAR 50 DEGREES.
SATURDAY...A DECENT SHORTWAVE TROUGH MOVES INTO
SASKATCHEWAN...WITH THE SFC TROUGH AXIS PUSHING INTO CENTRAL ND.
TEMPS WILL BE VERY WARM WITH THE THERMAL RIDGE OVER THE AREA...AND
WITH DECENT MIXING HIGHS COULD GET INTO THE LOW 80S IN SOME AREAS.
SFC DEWPOINTS WILL BE INCREASING...WITH PWAT VALUES UP TO AND EVEN
ABOVE 1 INCH. THERE COULD BE SOME CAPE VALUES NEAR 1000 J/KG AND
WITH DEEP LAYER BULK SHEAR VALUES OF 45 TO 50 KTS SOME MARGINAL
SEVERE STORMS ARE POSSIBLE. HAVE POPS STARTING OUT SLOW IN THE
WEST DURING THE EARLY AFTERNOON BUT RAMPING UP LATE SATURDAY
TOWARDS SATURDAY NIGHT.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 259 AM CDT FRI MAY 1 2015
SATURDAY NIGHT THROUGH SUNDAY NIGHT...THE UPPER SHORTWAVE WILL
MOVE FROM MANITOBA INTO ONTARIO...BRINGING A COLD FRONT DOWN THROUGH
THE NORTHERN PLAINS. THERE SHOULD BE SOME GOOD THUNDERSTORM
ACTIVITY ALONG THE FRONT OVER THE SOUTHERN AND EASTERN COUNTIES AT
THE START OF THE PERIOD...AND MODELS SHOW ACTIVITY CONTINUING INTO
SUNDAY BEFORE THE BOUNDARY PUSHES OFF TO THE SOUTHEAST SUNDAY
NIGHT. KEPT THE HIGHEST POPS IN THE SOUTH AND EAST...BUT SOME
MODELS SHOW SOME ADDITIONAL DEVELOPMENT FURTHER BACK BEHIND THE
FRONT TOWARDS SUNDAY MORNING. TEMPS WILL BE MILD SATURDAY NIGHT
THANKS TO CLOUDS AND PRECIP. HIGHS ON SUNDAY WILL BE QUITE A BIT
COOLER THAN SATURDAY ALTHOUGH STILL ABOVE AVERAGE IN THE 60S TO
LOW 70S...DROPPING DOWN INTO THE UPPER 30S TO 40S SUNDAY NIGHT.
MONDAY THROUGH THURSDAY...THE UPPER LEVEL FLOW WILL SHIFT TO A
SOUTHWEST FLOW PATTERN FOR THE LONG TERM AND BRING AN INCREASED
CHANCE FOR PRECIPITATION...ESPECIALLY DURING THE MIDWEEK. MODELS
ARE INDICATING AN OPEN GULF WITH AMPLE MOISTURE TO BRING SHOWERS
AND CONVECTION THROUGHOUT THE CNTRL PLAINS AND NORTHERN TIER OF
THE CONUS. HOWEVER...THERE ARE STILL DIFFERENCES ON PLACEMENT AND
TIMING OF CYCLONE AND WILL REMOVE ANY LIKELY POPS AT THIS TIME
ALTHOUGH THERE IS A HIGH LIKELIHOOD IN THE WED/THU TIMEFRAME.
DAYTIME HIGHS WILL GENERALLY BE IN THE 60S AND 70S WITH A LITTLE
MORE HUMIDITY THAN WE HAVE SEEN THE LAST COUPLE OF WEEKS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1144 PM CDT THU APR 30 2015
RAIN SHOWER BAND MOVING EAST AS EXPECTED WITH VFR CIGS. SKIES
CLEARING QUICKY BEHIND IT WITH SKY CLEAR AT DVL NOW AND SKIES WILL
CLEAR OVERNIGHT INTO THE RRV AND REACH BJI AREA MID MORNING.
QUESTION WILL BE FOG POTENTIAL. CLEAR SKY BEHIND LINE AND LIGHT
WINDS AFTER SOME LIGHT RAIN MEANS SOME FOG POTENTIAL. HRRR MODEL
SHOWS SOME AND THREW IN SOME MVFR VSBYS FOR BR INTO TVF/DVL/GFK
OVERNIGHT AS THAT MODELS SHOWS A BETTER CHC IN THIS AREA. AS USUAL
WITH RADIATIONAL FOG DEVELOPMENT AND COVERAGE/INTENSITY IS
UNCERTAIN. SKIES WILL BE CLEAR ON FRIDAY WITH A WEST WIND NR 10
KTS.
&&
.FIRE WEATHER...
ISSUED AT 259 AM CDT FRI MAY 1 2015
A VERY DRY AIRMASS WILL REMAIN IN PLACE IN THE CENTRAL AND WESTERN
DAKOTAS FRIDAY. LIGHT RAIN SHOWERS DEVELOPED IN FAR EASTERN ND AND
MOVED ACROSS NW AND W CNTRL MN THIS EVENING...BUT THE DVL REGION
RECEIVED LITTLE IF ANY PRECIP. DEWPOINTS THIS AFTERNOON WILL BE IN
THE UPPER TEENS. HOWEVER...WHILE A DEEP ADIABATIC LAYER WILL SET UP
BY 21Z...WINDS THROUGHOUT THE COLUMN ARE ON THE ORDER OF 10 KTS.
FURTHER WEST...COLUMN WINDS ARE AROUND 20KTS AT MINOT. NEAR CRITICAL
FIRE WEATHER CONDITIONS WILL EXIST IN THE DEVILS LAKE REGION UP
THROUGH LANGDON...BUT THE HIGHER THREAT WILL BE ACROSS WESTERN AND N
CNTRL ND AND WILL HOLD OFF ON A RED FLAG WARNING DUE TO WEAK FLOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/SPEICHER
AVIATION...RIDDLE
FIRE WEATHER...SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1214 AM CDT FRI MAY 1 2015
.UPDATE...
ISSUED AT 1211 AM CDT FRI MAY 1 2015
LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH EXITING THE
JAMES RIVER VALLEY AT THIS TIME...WITH RAIN SHOWERS EXPECTED TO
DIMINISH AND END ACROSS THE SOUTHERN JAMES RIVER VALLEY BY 07Z.
SURFACE OBSERVATIONS AND SATELLITE SHOW FOG JUST EAST OF THE
TURTLE MOUNTAINS...WITH THE LATEST HRRR LOW VISIBILITY FORECAST
JUST GRAZING ROLETTE AND POSSIBLY PIERCE COUNTIES OVERNIGHT...SO
HAVE ADDED IN PATCHY FOG. OTHERWISE CLEAR FORECAST WITH HIGH
CLOUDS APPROACHING THE NORTHWEST AND NORTH CENTRAL OVERNIGHT.
CONCERN FOR FRIDAY AFTERNOON WILL BE FIRE WEATHER AND WILL BE
FOCUSING ON THIS FOR THE NEXT UPDATE.
UPDATE ISSUED AT 956 PM CDT THU APR 30 2015
FORECAST FOR THE REMAINDER OF THE NIGHT REMAINS ON TRACK AS THE
COLD FRONT HAS EXITED INTO THE RED RIVER VALLEY. FOLLOWING TRENDS
IN THE 00-01 UTC HRRR ITERATIONS...POST-FRONTAL RAIN SHOWERS ARE
EXPECTED TO CONTINUE ACROSS THE JAMES RIVER VALLEY THROUGH 06-07
UTC.
UPDATE ISSUED AT 704 PM CDT THU APR 30 2015
QUICK UPDATE TO EXPIRE THE RED FLAG WARNING ON TIME AT 00 UTC. AS
OF 00 UTC...THE SURFACE COLD FRONT WAS LOCATED FROM FAR NORTHEAST
NORTH DAKOTA THROUGH LAKE OAHE...WITH LIGHT RAIN ALONG AND BEHIND
THE FRONT. HOWEVER...A SIGNIFICANT PORTION OF THIS PRECIPITATION
WAS NOT REACHING THE GROUND ACROSS THE SOUTH CENTRAL.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 244 PM CDT THU APR 30 2015
MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE FIRE WEATHER
CONCERNS THIS AFTERNOON...AND AGAIN FRIDAY AFTERNOON.
CURRENTLY...A COLD FRONT IS SITUATED FROM AROUND BOTTINEAU TO
BISMARCK. AHEAD OF THE FRONT...SOUTHERLY WINDS 15 TO 20 MPH WITH
GUSTS OF 25 TO 30 MPH. THIS IS RESULTING IN MINIMUM HUMIDITIES
AROUND 25 PERCENT FROM SOUTHEAST EMMONS COUNTY...TO THE UPPER
TEENS OVER THE JAMES RIVER VALLEY. CRITICAL FIRE WEATHER CRITERIA
IS MARGINAL OVER THE THE WESTERN PORTION OF THE WARNING BUT WINDS
WILL INITIALLY BE GUSTY BEHIND THE FRONT...SO ALTHOUGH HUMIDITIES
WILL RISE WITH THE FRONTAL PASSAGE...WILL KEEP THE RED FLAG
WARNING IN EFFECT UNTIL AFTER THE FRONTAL PASSAGE WHEN WINDS
DIMINISH AND HUMIDITIES RISE.
WILL KEEP THE MENTION OF AFTERNOON THUNDER...ALTHOUGH CHANCES WILL
BE MINIMAL.
TONIGHT...SHOWERS WILL END ACROSS CENTRAL NORTH DAKOTA THIS
EVENING...WITH MOSTLY CLEAR SKIES DEVELOPING WEST TO EAST
OVERNIGHT. LOWS WILL BE IN THE MID 30S WEST TO MID 40S SOUTHEAST.
FRIDAY...MOSTLY SUNNY AND CONTINUED MILD FRIDAY BEHIND THE FRONT
WITH A WEST TO SOUTHWEST SURFACE FLOW. BUFR SOUNDINGS INDICATE
SUSTAINED WINDS 15 TO 20 MPH FRIDAY AFTERNOON WITH GUSTS OF 25 TO
30 MPH...ACROSS THE NORTHWEST AND NORTH CENTRAL. WITH MINIMUM
HUMIDITIES AROUND 20 PERCENT...CRITICAL FIRE WEATHER CONDITIONS
WILL BE POSSIBLE. WILL ISSUE A FIRE WEATHER WATCH FOR PORTIONS OF
THE WEST CENTRAL..THE NORTHWEST AND NORTH CENTRAL 18Z FRIDAY TO
00Z SATURDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 244 PM CDT THU APR 30 2015
CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS THROUGH THE WEEKEND WITH
THE POTENTIAL FOR CONSIDERABLE RAIN BY MID WEEK...HIGHLIGHTS THE
LONG TERM.
THE CURRENT MODEL PACKAGE PROVIDES GOOD AGREEMENT ON AN UPPER LEVEL
TROUGH DEVELOPING AND MOVING EASTWARD ACROSS THE CENTRAL CANADIAN
PLAINS THROUGH THE WEEKEND. SHOWERS AND THUNDERSTORMS ARE POSSIBLE
AHEAD OF THE ASSOCIATED SURFACE FRONT. THE GREATEST CHANCES FOR
THUNDERSTORM ACTIVITY LOOK TO BE IN THE SOUTHEAST.
THEREAFTER...ZONAL FLOW ALOFT WILL TRANSITION TO SOUTHWESTERLY FLOW
AHEAD OF AN UPPER LEVEL TROUGH DIGGING INTO THE PACIFIC
NORTHWEST...EARLY NEXT WEEK. AS A RESULT...LEE TROUGHING IS EXPECTED
AT THE SURFACE WITH MOISTURE TRANSPORT AND ATMOSPHERIC INSTABILITY
CREATING WIDESPREAD CHANCES FOR SHOWERS AND THUNDERSTORMS. ALTHOUGH
MODELS HAVE SHOWN CONSISTENT AGREEMENT ON OVERALL PRECIPITATION
DEVELOPMENT...TIMING/LOCATION REMAINS UNCERTAIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1211 AM CDT FRI MAY 1 2015
VFR CIGS/VSBYS NEXT 24HR. EXPECT SOUTHWEST WINDS TO AROUND 25KT
AT KISN/KMOT/KDIK FRIDAY AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM THIS AFTERNOON THROUGH THIS EVENING FOR
NDZ001>005-009>013-017>019-021-031-032.
&&
$$
UPDATE...KS
SHORT TERM...TWH
LONG TERM...AC
AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1148 PM CDT THU APR 30 2015
.UPDATE...
ISSUED AT 1144 PM CDT THU APR 30 2015
COLD FRONT ENTERING ERN FCST AREA NEAR A WARROAD TO FOSSTON TO
NEAR WAHPETON LINE. AREA OF SHOWERS JUST WEST OF FRONT MOVIGN EAST
AS WELL. ONE BIT HEAVIER BATCH LIFTED INTO MANITOBA AND A BIT
HEAVIER RAIN AREA (MAYBE UP TO 0.25) SOUTHWEST OF FARGO. OTHERWISE
RAINFALL IS LIGHT (AROUND 0.05 OR SO). SKIES CLEAR QUICKYL BEHIND
SHOWER BAND. QUESTION IS FOG IN CLEARING LATER TONIGHT. LATEST
HRRR HINTS AS SOME LOWER VSBYS IN NRN VALLEY OVERNGITH AND LAST
OBS FROM LANGDON ND (KD55) SHOWS SOME BR ALREADY. SO WILL THROW IN
SOME PATCHY FOG TO MAINLY NRN VALLEY OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 347 PM CDT THU APR 30 2015
A PROGRESSIVE PATTERN WAS ACROSS THE STATES IN A ZONAL FLOW. UPPER
LEVEL JET MOVING INTO SOUTHWEST CANADA WILL MOVE ACROSS SOUTHERN
MANITOBA FRI THROUGH SUN. UPPER LEVEL TROUGH OVER MT WILL MOVE
ACROSS THE FORECAST AREA TONIGHT. PRECIPITATION WAS GENERALLY IN THE
700 HPA THETA-E RIDGE OR THE GRADIENT. PRECIPITABLE WATER WILL RISE
TO NEAR AN INCH OVERNIGHT OR EAST OF THE FRONT. FRONT/WIND SHIFT
WILL MOVE THROUGH FORECAST AREA TONIGHT THEN WASH OUT. RETURN FLOW
TO OCCUR FRI.
NEXT TROUGH OVER THE GULF OF AK WILL MOVE ACROSS SOUTHERN CANADA ON
SUN. TROUGH WILL SEND ANOTHER COLD FRONT ACROSS THE FORECAST AREA
SAT AFTERNOON AND SAT NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 347 PM CDT THU APR 30 2015
FOR SUNDAY NIGHT THROUGH THURSDAY...THE PERIOD WILL START OUT DRY TO
START THE WEEK. MODELS ARE COMING INTO BETTER AGREEMENT WITH
INCREASING CHANCES FOR SHOWERS AND SOME THUNDER WED/THU. PWATS WILL
RISE TO AROUND 1.30 INCHES...ALONG WITH SOME ELEVATED INSTABILITY
WITH SHOWALTERS SLIGHTLY NEGATIVE AND STRONG MOISTURE TRANSPORT.
THIS WOULD BE BENEFICIAL RAIN THAT COULD TOTAL AN INCH OR MORE
PERHAPS IN SOME AREAS FOR WED THROUGH THU. TEMPS SHOULD BE ABOVE
NORMAL THROUGH THE PERIOD WITH SOME COOLING BY WED/THU WITH MORE
CLOUDS/PRECIP.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1144 PM CDT THU APR 30 2015
RAIN SHOWER BAND MOVING EAST AS EXPECTED WITH VFR CIGS. SKIES
CLEARING QUICKY BEHIND IT WITH SKY CLEAR AT DVL NOW AND SKIES WILL
CLEAR OVERNIGHT INTO THE RRV AND REACH BJI AREA MID MORNING.
QUESTION WILL BE FOG POTENTIAL. CLEAR SKY BEHIND LINE AND LIGHT
WINDS AFTER SOME LIGHT RAIN MEANS SOME FOG POTENTIAL. HRRR MODEL
SHOWS SOME AND THREW IN SOME MVFR VSBYS FOR BR INTO TVF/DVL/GFK
OVERNIGHT AS THAT MODELS SHOWS A BETTER CHC IN THIS AREA. AS USUAL
WITH RADIATIONAL FOG DEVELOPMENT AND COVERAGE/INTENSITY IS
UNCERTAIN. SKIES WILL BE CLEAR ON FRIDAY WITH A WEST WIND NR 10
KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...HOPPES
LONG TERM...DK
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
139 AM EDT FRI MAY 1 2015
.SYNOPSIS...
VIGOROUS MID/UPPER LOW PRESSURE CROSSES TO OUR SOUTHEAST TONIGHT.
INSTABILITY SHOWERS THEN LINGERING LOWER CLOUDS/SHOWERS OVERNIGHT.
HIGH PRESSURE FOR THE WEEKEND...WITH A WARMING TREND INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
800 PM UPDATE...
NOT MUCH CHANGE IN THE FCST WITH THE EVE UPDATE. FINESSED POPS
USING LATEST HRRR AS A BASE WHICH PIVOTS BANDS OF SHRA THRU
OVERNIGHT ACROSS S ZONES.
PREVIOUS DISCUSSION BELOW...
AN UPPER LEVEL LOW PRESSURE SYSTEM DROPS SOUTH INTO OH
TONIGHT...TURNING SOUTHEAST ACROSS EASTERN KY OVERNIGHT. SCATTERED
SHOWERS ARE NOTED ALONG THE PERIPHERY OF THIS CIRCULATION WITH
EMBEDDED THUNDERSTORMS SOUTH AND WEST OF ITS CENTER. TONIGHT THE
WEATHER REMAINS UNSETTLED WITH LIGHT SHOWERS DRIFTING EAST. FEW
THUNDERSTORMS CAN BE POSSIBLE ACROSS THE EXTREME SOUTHERN PORTIONS
OF WV...NORTHEAST OH...AND SOUTHWEST VA TONIGHT. AS THE LOW EXITS
SOUTHEAST...IMPROVING CONDITIONS WILL SPREAD FROM WEST TO EAST
EARLY FRIDAY.
MODELS SUGGEST THAT ABUNDANT LINGERING MOISTURE WILL PROVIDE FOR
LOW LEVEL CLOUDS OVERNIGHT INTO EARLY FRIDAY. BUFKIT SOUNDINGS
INDICATE DRIER AIR FILTERS IN FROM THE WEST LATE FRIDAY...PERHAPS
BRINGING PERIODS OF SUNSHINE DURING THE AFTERNOON HOURS ACROSS
SOUTHEAST OH.
WITH ABUNDANT CLOUDINESS...TEMPERATURES TONIGHT WILL BE IN THE
40S. FRIDAY...TEMPERATURES WILL RANGE FROM THE MID 60S
LOWLANDS...INTO THE MID 50S HIGHEST ELEVATIONS. WENT CLOSER TO THE
COOLER BIAS CORRECTED ECMWF FOR LOWS TONIGHT...AND WITH THE
CONSENSUS RAW FOR HIGHS ON FRIDAY.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
INSTABILITY AND LOW LEVEL UPSLOPE FLOW WANE FRI EVENING WITH LOSS OF
HEATING AND UPPER LEVEL TROUGH PULLING AWAY. ANY MOUNTAIN SHOWERS
WILL DIE OFF BY MIDNIGHT AS A RESULT.
OTHERWISE HIGH PRESSURE SAILS SLOWLY ACROSS THE AREA THIS WEEKEND TO
PROVIDE NICE WEATHER. UPPER LEVEL RIDGING BUILDS TO THE W OF THE
FCST AREA...BUT A WEAK S/W TROUGH CROSSING LATE SAT AND AN EVEN
WEAKER ONE LATE SUNDAY WILL BRING SOME MID AND HIGH CLOUD...AND
THERE WILL ALSO BE SOME AFTERNOON CU...SO THE DAYTIME HOURS WILL
BRING A MIX OF CLOUDS AND SUNSHINE. LEFT THE SCHC FOR A SHOWER IN
THE WV MOUNTAINS SAT AFTERNOON ON ELEVATED HEATING...ALTHOUGH THE
AREA MAY BE UNDERNEATH WEAK RIDGING BETWEEN THE EXITING UPPER LEVEL
TROUGH...AND THE S/W COMING FROM THE W WHICH CROSSES SAT AFTERNOON
AND NT.
TEMPERATURES ARE CLOSE TO GUIDANCE AND NORMAL IN THIS RELATIVELY
TRANQUIL PATTERN...EXCEPT HIGHS SAT WERE A LITTLE ABOVE GUIDANCE AND
WERE LEFT ALONE IN LIGHT OF EARLY MAY SUNSHINE. TRIED TO TWEAK
HIGHS SUNDAY UPWARD TOWARD THE LATEST MEX...AGAIN IN TH EARLY MAY
SUN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
USED THE ECMWF ENSEMBLE MEAN AS THE BASIS FOR THE FORECAST. THIS
WOULD HAVE HIGH PRESSURE IN CONTROL FOR SUNDAY NIGHT AND MONDAY.
WITH THE HIGH SLIDING EASTWARD...MOISTURE INCREASES. THIS MAY ALLOW
FOR SOME AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ON TUESDAY.
BY WEDNESDAY...A FRONTAL BOUNDARY ATTEMPTS TO SLIDE INTO SOUTHEAST
OHIO AND NORTHERN WEST VIRGINIA BEFORE RETURNING BACK NORTHWARD ON
THURSDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
UPPER LEVEL LOW IS ROTATING SLOWLY TO THE SOUTH WHILE SATURATING
THE LOWER LEVELS OF THE ATMOSPHERE. ALSO...SHOWERS ARE PRESENT
OVER THE MOUNTAINS...AND WILL BE DEVELOPING OVER THE NORTHERN
LOWLANDS.
FORECAST SOUNDINGS SHOW THE POTENTIAL FOR MVFR TO IFR CEILINGS AS
WE GO TOWARDS 12Z THIS MORNING. THIS DECREASES CONFIDENCE IN THE
OVERALL FORECAST.
FIGURE VISIBILITIES WILL NOT BE A CONSISTENT ISSUE WITH CLOUDS AND
BRIEF SHOWER ACTIVITY...ALONG WITH A LIGHT WIND REMAINING IN
PLACE.
MOUNTAINS WILL HAVE THE POSSIBILITY OF THUNDER IN THE VICINITY
DURING THE AFTERNOON HOURS FRIDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: LOWERING CEILING TONIGHT MAY NOT DEVELOP...OR
MAY NEED MORE EXTENSIVE IFR. AMENDMENTS MAY BE NEEDED.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE FRI 05/01/15
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY M M H M M M L H H H M M
HTS CONSISTENCY M M H H H M M H H H H H
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY L L L L H H H H H H H H
PKB CONSISTENCY M M M L H M H M M M M H
CKB CONSISTENCY H H H H H H H H M M M H
AFTER 06Z SATURDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/TRM/RPY
NEAR TERM...ARJ/30/26
SHORT TERM...TRM
LONG TERM...RPY
AVIATION...26
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
217 AM EDT FRI MAY 1 2015
.SYNOPSIS...
AN UPPER LEVEL LOW WILL HEAD INTO NORTH CAROLINA TODAY. THIS
UPPER LEVEL LOW SHOULD DEPART BY FRIDAY NIGHT...AND HIGH PRESSURE
WILL ARRIVE TO BRING WARMER WEATHER FOR EARLY NEXT WEEK. THE
CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS WILL RETURN AS THE
WEEK PROGRESSES.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 200 AM EDT FRIDAY...
FORECAST UPDATED TO CONCENTRATE HIGHER POPS FROM SRN
WV...SOUTHEAST ACROSS THE NEW RIVER VALLEY INTO THE NW PIEDMONT OF
NC...ALONG AXIS OF BEST SFC AND UPPER LEVEL FORCING AHEAD OF THE
UPPER LOW. EXPECT THE SHOWERS TO PIVOT SW OVER THE MTNS AND TO THE
NORTH OVER THE PIEDMONT AS EVIDENCED ON RADAR. AS THE LOW MOVES
ACROSS NRN NC LATER THIS MORNING THE SHOWERS TO SHIFT FURTHER
NORTHEAST TOWARD THE LYH/FVX AREA WITH SOME DRY SLOTTING
DEVELOPING OVER THE NC MTNS/FOOTHILLS. AS SUCH KEPT SOME TREND OF
OFFICIAL FORECAST THEN MADE SOME ADJUSTMENTS BASED ON LATEST
HRRR/LOCAL WRF. OTHER ISSUE IS COLD AIR ALOFT. RADAR SHOWING
BRIGHT BANDING OVER THE NRV INTO SRN WV...WITH EVIDENCE OF FZ LVL
ABOUT 2000FT AGL. AS SUCH ADDED SOME SNOW MIXED IN ALONG THE
HIGHER TERRAIN ABOVE 4KFT. PLACES LIKE MT ROGERS AND BEECH MTN
COULD SEE A DUSTING TO AN MAYBE AN INCH. TEMP AT BEECH MTN AT 32F.
PREVIOUS DISCUSSION FROM LATE THURSDAY EVENING...
UPPER LOW CONTINUES TO DRIFT SOUTHEAST AND IN SO
DOING...RAIN SHOWERS HAVE SPREAD BACK INTO THE REGION FROM THE
NORTHWEST...GENERALLY PIVOTING ABOUT THE ROA/BCB REGION. ONE AREA
OF RAIN PERSISTED FOR QUITE SOME TIME ACROSS NORTHERN
PITTSYLVANIA/SOUTHERN CAMPBELL COUNTY WHERE DOPPLER RAINFALL
ESTIMATES 1.5 TO 2.0 INCHES OF RAIN HAS FALLEN TODAY. CURRENT
TREND ON POPS LOOKS GOOD. NOT SEEING ANY LIGHTNING ANY MORE AND
WITH THE LOSS OF DAYTIME HEATING WOULD NOT EXPECT ANY FROM THIS
POINT FORWARD. PREVIOUS GRIDS CAPTURED THE ENDING TIME OF THAT AS
WELL. EARLIER ADJUSTMENT DOWNWARD OF TEMPERATURES HAS BEEN ON
TRACK AND OTHER THAN A MINOR ADJUSTMENT DOWNWARD ACROSS THE
PIEDMONT...TEMPERATURES APPEAR TO BE ON TRACK FOR THE REMAINDER OF
THE NIGHT. SYNOPTIC SITUATION NOT PARTICULARLY SUPPORTIVE OF
FOG...SO WILL NOT ADD ANY IN THE GRIDS AT THIS TIME.
AS OF 730 PM EDT THURSDAY...
SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO
ROTATE AROUND THE UPPER LOW. MAIN AREA AT THIS MOMENT HAS SHIFTED
OVER INTO THE NC PIEDMONT OUT OF OUR CWA...BUT A NEW AREA IS
POISED TO MOVE INTO FAR SW VA. HRRR INDICATES ACTIVITY UP IN
PA/NORTHERN VA/MD WILL SHIFT SOUTH OVERNIGHT ACROSS THE CWA FROM
NORTH-SOUTH AS THE UPPER LOW MOVES ESE TOWARD THE COAST. THE
PRECIPITATION RESULTED IN SOME SIGNIFICANT EVAPORATIVE COOLING IN
THE WEST WITH TEMPERATURES DOWN IN THE 40S IN THE WESTERN
COUNTIES. THUS...HAD TO LOWER TEMPERATURES IN THOSE AREAS A GOOD
10 DEGREES. HOWEVER...ADDITIONAL COOLING OVERNIGHT SHOULD BE
LIMITED AS TEMPERATURES NEAR DEWPOINT. ONLY ADJUSTED OVERNIGHT
MINS DOWN A COUPLE OF DEGREES. DID NOT ADJUST POPS MUCH AS HRRR
SHOWS ACTIVITY CONTINUING MUCH OF THE NIGHT. WILL RE-EVALUATE POPS
WITH LATER UPDATES.
AS OF 405 PM EDT THURSDAY...
AN UPPER LEVEL LOW CONTINUES TO HEAD CLOSER TO THE WESTERN PORTION
OF THE CWA. CURRENTLY...SCATTERED SHOWERS AND THUNDERSTORMS ARE
LINING UP OVER THE PIEDMONT. WEAK FLOW ALOFT IS CAUSING
CONSIDERABLY SLOW STORM MOTIONS. DUE TO EARLIER SUNSHINE AND
STEEPENING LAPSE RATES AS COOLER AIR ARRIVES ALOFT...SOME SMALL
HAIL IS LIKELY IN THE STRONGER STORMS. WE HAVE ALREADY RECEIVED
SEVERAL REPORTS OF PEA TO DIME SIZE HAIL THIS AFTERNOON...BUT
NOTHING HAS REACHED SEVERE LIMITS. MEANWHILE...MORE SHOWERS AND
THUNDERSTORMS ARE SPREADING OVER THE WESTERN MOUNTAINS. THIS
ACTIVITY IS MUCH LESS ORGANIZED...BUT IT COULD PICK UP A LITTLE
DURING THE NEXT SEVERAL HOURS.
BY TONIGHT...THE UPPER LEVEL LOW WILL BE DIRECTLY OVERHEAD...WHICH
WILL KEEP THE SHOWER ACTIVITY ONGOING THROUGHOUT THE NIGHT.
HOWEVER...THUNDER CHANCES SHOULD DIMINISH AFTER MIDNIGHT. CLOUD
COVER WILL BE WIDESPREAD...WHICH MEANS LOW TEMPERATURES COULD DROP
NO FURTHER THAN THE 40S. ALTHOUGH MOISTURE WILL GRADUALLY SUBSIDE
DURING FRIDAY...THE SHOWERS WILL LINGER INTO FRIDAY AFTERNOON. THE
ACTIVITY SHOULD SPREAD EASTWARD INTO THE PIEDMONT...AND EVENTUALLY
CLEAR THE CWA BY SUNSET. HIGHS ON FRIDAY MAY BE A LITTLE TRICKY IF
THE CLOUD COVER TRIES TO SCATTER SOONER THAN ANTICIPATED BY THE
MODELS. ONLY MID 50S TO LOWER 60S ARE EXPECTED FOR HIGHS...WHICH
ARE A COUPLE DEGREES BELOW MOS GUIDANCE.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 215 PM EDT THURSDAY...
SATURDAY NIGHT...SOME LINGERING SHOWERS WILL STILL BE POSSIBLE
DURING THE EARLY EVENING HOURS FROM EARLIER CONVECTION SATURDAY
AFTERNOON. THE GREATEST CONCENTRATION WILL BE ACROSS THE
MOUNTAINS...ALONG AND NORTH OF ROUTE 460.
ON SATURDAY...ONE LAST SHORTWAVE TROUGH WILL SPIRAL AROUND THE WEST
SIDE OF THE DEPARTING UPPER LOW. ANTICIPATED ISOLATED TO SCATTERED
SHOWERS TO DEVELOP DURING THE PEAK HEATING OF THE AFTERNOON ACROSS
THE EASTERN HALF OF THE REGION. INSTABILITY AT THIS TIME APPEARS TOO
WEAK TO INCLUDE MENTION OF ISOLATED STORMS.
SATURDAY NIGHT INTO SUNDAY...AN UPPER RIDGE WILL START TO BUILD JUST
WEST OF THE REGION. THIS WILL BE THE START OF THE TREND OF MILDER
CONDITIONS AND A MUCH LOWER PROBABILITY OF PRECIPITATION. AT
BEST...ISOLATED SHOWERS MAY OCCUR SUNDAY AFTERNOON ACROSS THE
NORTHERN MOUNTAINS OF NORTH CAROLINA.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 1230 PM EDT THURSDAY...
UPPER LEVEL RIDGING WILL CONTINUE ACROSS THE REGION DURING THE
MAJORITY OF THIS PORTION OF THE FORECAST. AN UPPER LOW MOVING
EASTWARD THROUGH CANADA WILL WEAKEN THE RIDGE A BIT WEDNESDAY INTO
THURSDAY...SHIFTING A BACKDOOR FRONT TOWARD OUR REGION. WHILE ALL OF
THIS IS OCCURRING...AN ELONGATED TROUGH/UPPER LOW WILL BE DEVELOPING
ACROSS THE CENTRAL PART OF THE COUNTRY. WE ARE ANTICIPATING
PROGRESSIVELY MILDER TEMPERATURES EACH DAY WITHIN THIS REGIME. FOR
PRECIPITATION...THE CENTER OF THE SURFACE HIGH WILL JUST BE SHIFTING
EAST OF THE AREA ON MONDAY. THIS WILL LIMIT THE DEGREE OF RETURN
MOISTURE INTO THE AREA TO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
IT IS HERE WHERE ISOLATED SHOWERS WILL BE FORECAST FOR THE
AFTERNOON. FROM TUESDAY INTO THURSDAY...COVERAGE OF SHOWERS AND
STORMS WILL BE INCREASING...ESPECIALLY IN THE WEST...WITH THE
APPROACH...AND POTENTIAL ARRIVAL...OF THE BACKDOOR FRONT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 200 AM EDT FRIDAY...
SHOWERS WILL BE MORE NUMEROUS OVERNIGHT INTO FRIDAY AS UPPER LOW
MOVES FROM THE MTNS OF SW VA INTO THE NC PIEDMONT. AXIS OF
MODERATE TO HEAVY SHOWER SHOULD AFFECT BLF-BCB-DAN THIS MORNING
THEN LIFT NE TO ROA/LYH AND POSSIBLY LWB THROUGH THE MORNING.
NOT GOING TO GET CUTE WITH THE INS AND OUTS OF LIGHT TO MODERATE
RAIN AND KEEP IT MOSTLY LIGHT. FREEZING LEVEL IS ABOUT 4-5KFT
MSL...SO MAY HAVE TO DEAL WITH ICING.
THE TERMINALS SHOULD GO TO SUB VFR IF NOT ALREADY THERE AS LOW
LVLS MOISTEN UP. KEEPING SOME FOG IN AS WELL ACROSS THE MTNS LATER
THIS MORNING.
MODELS SHOWING INCREASE IN CIGS TOWARD MID TO LATE MORNING AND
WILL TREND THAT WAY...WHICH WE ALREADY HAD IN THE PREVIOUS
TAFS. THE RAIN SHOWER SWING EAST THROUGH THE DAY AND SHOULD BE
GONE FRIDAY AFTERNOON...WITH ALL SITES TURNING TO VFR...THOUGH NW
FLOW IS GOING TO PERSIST INTO THE MTNS...SO BLF APPEARS THEY MAY
KEEP MVFR CIGS THRU THE END OF THIS TAF PERIOD.
CONFIDENCE IS FAIRLY HIGH FOR WINDS/CIGS AND MEDIUM ON RAINFALL
INTENSITY AND VSBYS.
A SIGNIFICANT WEATHER PATTERN CHANCE WILL TAKE PLACE THIS
WEEKEND...AS HIGH PRESSURE BUILDS OVERHEAD. OTHER THAN POSSIBLE
EARLY MORNING MVFR FOG IN THE USUAL RIVER VALLEY LOCATIONS...VFR
CONDITIONS SHOULD PERSIST THROUGH THIS WEEKEND INTO EARLY NEXT
WEEK. A WARMER AND MOISTER AIR MASS COULD ALLOW FOR A FEW SHOWERS
TO POP UP DURING MONDAY AFTERNOON. A GREATER CHANCE OF
SHOWERS...WITH A FEW ISOLATED THUNDERSTORMS IN THE WESTERN
MOUNTAINS...ARE POSSIBLE FOR TUESDAY.
&&
.EQUIPMENT...
AS OF 150 AM EDT FRIDAY...
PART FOR THE UPPER AIR ARRIVED LATE FRIDAY EVENING AND TECHNICIANS
WILL WORK ON GETTING THIS FIXED TO HAVE A 12Z UPPER AIR RUN TODAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PW
NEAR TERM...PW/WP
SHORT TERM...DS/RAB
LONG TERM...DS
AVIATION...KK/PW/WP
EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
328 AM CDT FRI MAY 1 2015
.TODAY...FORECAST CONFIDENCE IS HIGH.
DRY AND SUNNY TO START THE DAY WITH HIGH PRESSURE OVER REGION.
SLOWLY INCREASING HIGH TO MID LEVEL CLOUDS FROM THE WEST WITH
APPROACHING SHORT WAVE TROUGH.
BRIEF PERIOD OF STRONG UPPER LIFT WITH CVA AHEAD OF SHORT MOVES
INTO THE WEST BETWEEN 21Z AND 00Z. NAM AND RAP SOUNDINGS/CROSS
SECTIONS DEPICTING A DEEPER MOIST LAYER ABOVE 10K FT THAN GFS
COINCIDENT WITH THIS LIFT...BUT ALL FORECAST SOUNDINGS ARE VERY
DRY BELOW 10K FEET...REFLECTING THE DRY LOWER LEVEL AIR IN PLACE
WITH THE HIGH.
CURRENT SHOWERS IN THE EASTERN DAKOTAS WITHIN NARROW RIBBON OF
MOISTURE RETURN/POOLING LIMITED TO RIGHT ALONG THE SURFACE TROUGH.
BUT SURFACE TROUGH WASHES OUT AS IT MOVES TOWARD WESTERN
WISCONSIN...WITH AN ATTENDANT SHARP REDUCTION IN FRONTOGENETIC
FORCING,
ADDED ISOLATED SPRINKLES IN THE FAR WEST MORE FOR
COLLABORATION... BUT WILL BE HARD TO GET ANY PRECIPITATION TO
REACH THE SURFACE THROUGH THE DEEP DRY LAYER AND WEAKENING
FORCING.
SLOWLY RISING 925 MB TEMPERATURES WILL YIELD HIGHS AROUND 70 IN
SOUTH CENTRAL WISCONSIN...WITH MID TO UPPER 60S OVER SOUTHEAST
WISCONSIN AWAY FROM THE LAKE...WITH WEAK GRADIENT ALLOWING A LIGHT
LAKE BREEZE THAT KEEPS AREAS WITHIN 5-10 MILES OF THE LAKE IN THE
50 TO 60 DEGREE RANGE.
.TONIGHT...FORECAST CONFIDENCE IS HIGH.
DECENT UPPER LEVEL LIFT CROSSES REST OF THE REGION WITH SHORT
WAVE THIS EVENING...BUT LAYERS BELOW 5K FEET NEVER SATURATE...AND
LOWER LEVEL FORCING WEAKENS RAPIDLY AHEAD OF TROUGH. WILL KEEP
TONIGHT DRY WITH ONLY CLOUDS MARKING THE PASSAGE OF THE TROUGH.
THE MOSTLY CLOUDY SKIES AND WEAK WARM ADVECTION ON SOUTHERLY WINDS
WILL KEEP LOWS IN THE MID-UPPER 40S...WITH A FEW 50 DEGREE LOWS IN
THE WEST.
.SHORT TERM...SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
MODELS ARE IN GOOD AGREEMENT WITH WARM AIR ADVECTION LINGERING
ACROSS THE AREA DURING THIS PERIOD. INCREASING SOUTH TO SOUTHWEST
WINDS ARE EXPECTED...BRINGING WARM TEMPERATURES TO MOST OF THE
AREA. ONSHORE WINDS NORTH OF PORT WASHINGTON MAY KEEP COOLER
TEMPERATURES THERE. HIGHS SHOULD REACH INTO THE 70S ON
SATURDAY...WITH HIGHS IN THE MID 70S TO AROUND 80 ON SUNDAY.
MOISTURE IS MEAGER SATURDAY INTO SATURDAY NIGHT ACROSS THE
AREA...SO NOT EXPECTING MUCH IN THE WAY OF PRECIPITATION...DESPITE
WARM AIR ADVECTION AND WEAK 500 MB VORTICITY MAXIMUM PASSING SOUTH
OF THE AREA. SUNDAY MAY END UP DRY AS WELL...WITH BEST UPWARD
VERTICAL MOTION AND MOISTURE COMBINATION NOT ARRIVING UNTIL SUNDAY
NIGHT...AS THE COLD FRONT APPROACHES FROM THE NORTHWEST.
KEPT SOME POPS FOR SUNDAY FOR NOW...BUT MAY NEED TO BE LOWERED OR
REMOVED IN LATER FORECASTS. KEPT LIKELY POPS FOR SUNDAY
NIGHT...WHICH MAY NEED TO BE RAISED IN LATER FORECASTS. AREA
FORECAST SOUNDINGS SUGGEST 500 TO 1000 J/KG MEAN LAYER OR ELEVATED
CAPE...THOUGH DEEP LAYER SHEAR IS MODEST AT BEST. SPC KEPT
MARGINAL SEVERE RISK NORTHWEST OF THE AREA SUNDAY...CLOSER TO THE
FRONT. SHOULD BRING SOME NEEDED RAINFALL TO THE AREA.
.LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF/GFS IN DECENT AGREEMENT WITH TAKING COLD FRONT INTO NORTHERN
ILLINOIS MONDAY...STALLING OUT MONDAY NIGHT INTO TUESDAY...BEFORE
SHIFTING BACK NORTH AS A WARM FRONT TUESDAY NIGHT INTO WEDNESDAY.
KEPT POPS GOING FOR THIS PERIOD...THOUGH THERE MAY BE MORE BREAKS
DURING THIS TIME. GFS WAS SHOWING WEAK CAPE...SO HAVE SOME SLIGHT
CHANCES FOR THUNDER GOING IN FORECAST. TEMPERATURES RETURN CLOSER
TO SEASONAL NORMALS...WITH ONSHORE WINDS NEAR THE LAKE.
MODELS DIFFER MORE INTO THURSDAY...THOUGH BOTH SHOWING SOME WARM
AIR ADVECTION DEVELOPING INTO THE AREA. USED CONSENSUS POPS AND
TEMPERATURES FOR WEDNESDAY NIGHT INTO THURSDAY FOR NOW.
&&
.AVIATION/12Z TAFS/...
VFR CONDITIONS THROUGH THE FORECAST WITH HIGH PRESSURE DOMINATING
THE FORECAST. WILL SEE INCREASING VFR CLOUDS...MAINLY ABOVE 10K
FT...MOVE FROM WEST TO EAST THIS AFTERNOON INTO THIS EVENING
WITH A WEAK UPPER LEVEL WAVE...BUT CLOUD DECK WILL NOT LOWER MORE
THAN 5K FEET WITH NO PRECIPITATION EXPECTED.
&&
.FIRE WEATHER...
MAX TEMPERATURES WEST OF THE KETTLE MORAINE WILL RANGE BETWEEN 65
AND 70 DEGREES...WITH MINIMUM RELATIVE HUMIDITY VALUES OF 25 TO 30
PERCENT WEST OF A RIPON...WATERTOWN TO DELAVAN LINE. SW WINDS WILL
BE BETWEEN 8 AND 10 MPH...WITH GUSTS BELOW 15 MPH THIS AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SATURDAY THROUGH THURSDAY...WOOD
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NWS MELBOURNE FL
924 AM EDT FRI MAY 1 2015
.DISCUSSION... RELATIVELY DRY NW FLOW WILL SLOWLY DIMINISH IN SPEED
WHILE VEERING MORE NLY LATER TODAY. AN ONSHORE WIND IN THE FORM OF
AN AFTERNOON SEABREEZE WL WORK INLAND THROUGH MID AFTERNOON. UNDER
MOSTLY SUNNY SKIES TEMPS WILL RISE INTO TEH LWR 80S INLAND AND
AROUND 80 ALONG THE COAST. THE CURRENT FORECAST IS IN GOOD SHAPE.
&&
.AVIATION...VFR.
&&
.MARINE... TODAY-TONIGHT...NORTHWEST WINDS WILL RESULT IN RATHER
BENIGN CONDITIONS FOR SMALL CRAFT OPERATORS NEAR THE COAST THIS
MORNING. A SEA BREEZE ALONG THE IMMEDIATE CST WILL VEER WINDS TO
NE AT EARLY TO MID AFTERNOON. A NORTHERLY SURGE TO 15 KNOTS IS
INDICATED LATE IN THE AFTERNOON IN THE NORTH AND SHIFTING TO THE
SOUTHERN WATERS AFTER MIDNIGHT. A CAUTION STATEMENT MAY BE NECESSARY
LATE TODAY / TONIGHT IN THE GULF STREAM IF THE SURGE TURNS OUT TO BE
SLIGHTLY STRONGER AS IS INDICATED BY LTST HRRR GUID.
&&
.FIRE WEATHER...COT`S ADVECTION SWD OF DRIER AIR WILL CAUSE MIN RH
VALUES TO FALL SLIGHTLY BELOW 35 PERCENT ALONG/NORTHWEST OF I-4.
WINDS ARE FORECAST TO REMAIN BELOW 15 MPH.
&&
.CLIMATE...
APRIL WAS THE RECORD WARMEST AT DAB/MLB/VRB. IT WAS THE SECOND
WARMEST APRIL AT MCO.
EVERY DAY WAS WARMER THAN NORMAL AT THESE SITES IN APRIL...EXCEPT
ON THE 30TH DAB WAS A FEW DEGREES BELOW THAN NORMAL WHILE MCO AND
MLB WERE RIGHT AT NORMAL.
STATION AVERAGE TEMP RECORD
DAB 75.3 74.4 IN 1947
MCO 77.6 78.7 IN 1908
MLB 77.1 75.1 IN 1947
VRB 76.9 75.4 IN 1945 & 1947
APRIL WAS WETTER THAN NORMAL: DAB WAS THE 7TH WETTEST ON RECORD
AND VRB WAS THE 10TH WETTEST ON RECORD.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
JP/ALM
AREA FORECAST DISCUSSION
NWS TOPEKA KS
619 AM CDT Fri May 1 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 332 AM CDT FRI MAY 1 2015
Water vapor loop shows nearly zonal stronger flow aloft across the
northern Rockies and northern Plains states with a well-defined
shortwave trough from the eastern Dakotas into northwest MN. A band
of showers is associated with lift ahead of upper trough moving
through western MN trailing back into northeast Nebraska at this
time. Forcing associated with this system should stay well to north
of forecast area today. However, regional radar loops show showers
and isolated thunderstorms occurring with trailing cold front/trough
from central Nebraska into northwest KS. There is some disagreement
among models but NAM, RAP and HRRR show remnants of this high-based
precip making it into north central KS by early afternoon and then
moving across far northeastern KS during the rest of the afternoon.
While confidence is not high in measurable precip with this
activity, have continued slight chance POPs for far northern
counties this afternoon. Something similar could happen again
tonight with developing showers and thunderstorms over western
Nebraska, which is forecast by some models to persist and move into
far northern parts of our area tonight. Once again, without a
stronger upper level system or recognizable front coming through,
this will be a low chance event, with slightly better chances to our
north.
Considerable mid and high level cloudiness today could make high
temp forecast tricky. Still think enough sunshine will get through
to allow highs to reach the mid to upper 70s.
.LONG TERM...(Saturday through Thursday)
Issued at 332 AM CDT FRI MAY 1 2015
By Saturday, fairly zonal mid-level flow will be in place with
surface high pressure prevailing across the southeastern U.S. and
surface low pressure extending along the High Plains. Models
continue to show a few weak embedded shortwaves developing within
the zonal flow on Saturday as a vort max skims just north of the
CWA. However, with no surface feature to help further support these
waves and with model soundings showing a decent amount of dry air in
the low levels, have only slight chance PoPs in across far northern
and far northeast Kansas Saturday morning with dry conditions by the
afternoon as the associated vort max lifts to the northeast. With
the above-mentioned surface pattern in place, southerly surface
winds should boost high temperatures into the upper 70s/low 80s.
Have gone with a dry forecast Saturday afternoon through Sunday
before the next system moves into the region, which will be the
beginning of a wet stretch of weather that looks to extend through
the latter part of next week. Models show the surface low advancing
eastward toward the CWA on Sunday, resulting in an increased
pressure gradient, breezy southerly winds, and thus good warm air
advection that should support the warmest temperatures of the week
with highs reaching into the low/mid 80s. Precipitation chances will
increase Sunday night through Monday as a cold front slowly sags
southeastward across the CWA. However, models show the front
stalling out over the southern portions of the forecast area and
pivoting over the area before lifting northward as a warm front to
just north of the KS/NE border on Tuesday. As a result, have chance
to likely PoPs for thunderstorms from Sunday night through Monday
night. Even though the cap looks to significantly weaken through the
day on Monday and the amount of available instability is modest,
wind shear looks to be fairly weak across the region, thus limiting
the potential for strong storms. With the warm front lifting into
Nebraska, ECMWF/GEM actually keep Tuesday predominantly dry while
the GFS tries to hold on to some scattered precipitation chances, so
have lowered PoPs. However, thunderstorm chances increase once again
by Tuesday night as a mid-level trough becomes negatively tilted and
begins to lift northward into the central U.S. This approaching
trough will not only provide additional forcing to support
thunderstorm development, but also push another area of surface low
pressure into the area by mid week. However, there are still model
discrepancies in the evolution of the mid-level trough as it lifts
northward and in the timing of the passage of the cold front, which
should track eastward across the area sometime during the latter
part of the week. As a result, there is uncertainty still with when
this system will exit the region. At this time, have chance to
likely PoPs in from Tuesday night through Thursday night. The best
potential for some more-organized storms looks to be during the mid
to late week period in which the combination of the surface low
pressure system and mid-level trough should provide decent forcing
along with decent instability and some slightly improved wind shear.
At this time, temperatures next week look to be fairly steady with
highs in the 70s and lows in the 50s to low 60s.
&&
.AVIATION...(For the 12Z TAFs through 12Z Saturday Morning)
Issued at 613 AM CDT FRI MAY 1 2015
Expect considerably high level cloudiness today. But clouds should
be at 10,000 ft and above. A very weak upper system could affect
area tonight and isolated showers are a possibility. However,
coverage is expected to be too isolated to mention in TAFs.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GDP
LONG TERM...Hennecke
AVIATION...GDP
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
551 AM CDT Fri May 1 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 322 AM CDT Fri May 1 2015
Dry and tranquil weather is expected today as weak height rises
commence aloft with the departure of the mid Atlantic upper
low/trof and eastward shift in the upper ridge currently centered
in the southern Rockies. The surface high centered in northern IL
will only meander southeast. This will translate to a nice day with
light winds, lots of morning sun, and some thin high clouds in the
afternoon. Temperatures will be seasonable and forecast highs are
a blend of the warmer MAV MOS and RAP 2m temps.
Glass
.LONG TERM: (Tonight through Thursday)
Issued at 322 AM CDT Fri May 1 2015
The tail end of a weak short wave passing to the north will bring
an increase in cloudiness overnight. The persistent and ever so
slowly retreating low level anticyclone will limit low level
moisture transport/return to the Plains into Iowa. That said the
increase in mid level moisture and warm advection may be
sufficient for spotty showers across parts of northeast MO. While
southerly flow and WAA becomes better established Saturday and
Saturday night in the wake of the slow retreating anticyclone,
trajectories are poor for low level moisture return. Once again
the main impetus for pops will be mid level moisture, WAA,
glancing influence from passing disturbances, and some marginal
elevated instability leading to slight chance pops across parts of
northeast MO and west central IL. The ridge aloft builds east into
the OH Valley on Sunday and the threat of precipitation takes a
decided northward shift to the vicinity of a cold front moving
through the northern Plains and upper MS Valley. The threat of
showers and thunderstorms will progressively increase late Sunday
night into Monday night as the cold front approaches Sunday night
and then becomes quasi-stationary across northern MO and west
central IL Monday into Monday night. By this time the low level
moisture and hence instability is much improved owing to
persistent s-sw lower trop flow and presence of steep mid level
lapse rates. This front then moves back north by midweek leading
to a diminished precipitation threat, which increases again late
week with the development of southwest flow aloft and accompanying
disturbances and continued low level moisture transport.
Temperatures will be above average beginning this weekend and
continuing all of next week.
Glass
&&
.AVIATION: (For the 12z TAFs through 12z Saturday Morning)
Issued at 550 AM CDT Fri May 1 2015
VFR conditions with light and vrb winds anticipated thru the
period. RA can not be ruled out at UIN late tonight. Otherwise, no
precip anticipated at terminals.
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
908 AM MDT FRI MAY 1 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...
CHINOOK ARCH HAS INTRODUCED A BOUNTIFUL AMOUNT OF HIGH CLOUDINESS
ACROSS THE CWA THIS MORNING. WITH WATER VAPOR SHOWING ADDITIONAL
MOISTURE UPSTREAM...THINK RUC HAS A GOOD HANDLE ON SKY AND THUS HAVE
INCREASED CLOUDS INTO TONIGHT. ALSO RAISED RH A BIT. REST OF
FORECAST LOOKED GOOD. TFJ
PREVIOUS DISCUSSION...
ZONAL FLOW OVER THE PACIFIC NORTHWEST AND NORTHERN ROCKIES OVER
THE NEXT FEW DAYS WILL PRODUCE DRY AND WARM CONDITIONS FOR
NORTHEAST MONTANA. A SHORTWAVE DIPPING THROUGH WESTERN CANADA OVER
THE WEEKEND WILL INTRODUCE SOME SLIGHT CYCLONIC CURVATURE TO THE
UPPER FLOW AND PUSH A COLD FRONT INTO NORTHERN MONTANA. MOST OF
THE MOISTURE AND ENERGY WITH THIS SYSTEM REMAINS WELL NORTH...SO
MAINLY EXPECT A WIND SHIFT FROM SOUTHWEST TO NORTHWEST EARLY ON
SATURDAY AND TEMPERATURES COOLING SLIGHTLY FROM TODAY INTO SUNDAY.
EBERT
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
THE EXTENDED FORECAST PERIOD BEGINS SUNDAY NIGHT WITH GENERALLY
ZONAL FLOW ALOFT OVER NORTHEAST MONTANA. OFF TO THE WEST THERE
WILL BE SHALLOW...MEDIUM-WAVE RIDGE BEGINNING TO WORK ITS WAY
EAST. THE WAVE NEVER GAINS MUCH STRENGTH AS IT PASSES OVER THE
LOCAL REGION LATE MONDAY. BUT GREAT BASIN WARMTH DOES PUSH NORTH
INTO MONTANA TO MAINTAIN SLIGHTLY ABOVE NORMAL TEMPERATURES.
BOTH GFS AND THE EC DEVELOP A CLOSED UPPER LOW OFF THE NORTHWEST
COAST MONDAY NIGHT. THIS LOW BEGINS TO PUSH THROUGH THE INTER-
MOUNTAIN WEST. MORE WARM AIR IS THUS NUDGED NORTH INTO OUR AREA
FOR A WARMER TUESDAY.
TUESDAY NIGHT AND WEDNESDAY BEGINS A WET PROGRESSIVE PATTERN...A
SURFACE TROUGH IN THE LEE OF THE NORTHERN ROCKIES MOVES OVER THE
LOCAL REGION CREATING INSTABILITY. FLOW ALOFT TURNS SOUTHWEST
SENDING MOISTURE FROM THE WESTERN TROUGH INTO THE LOCAL AREA.
TIMING IS NOT CERTAIN YET BUT BOTH GFS AND EC SUGGEST MODERATE
CAPE AND NEGATIVE LIFTED INDEX VALUES. THE SET-UP APPEARS GOODS
FOR AT LEAST GENERAL THUNDERSTORM DEVELOP LATE TUESDAY AND
WEDNESDAY. INTO THURSDAY THE MODELS SPLIT THE TROUGH INTO A
SOUTHWESTERN WAVE AND A NORTHEASTERN WAVE...WITH THE NORTHERN
PORTION AFFECTING THE AREA WITH CONTINUED CONVECTION AND SHOWERS.
SCT
&&
.AVIATION...
SOME HIGH CLOUDS AROUND FL240 DUE TO CHINOOK ARCHING FROM WESTERLY
FLOW ALOFT OVER THE NORTHERN ROCKIES. FLOW PATTERN ALOFT IS FAIRLY
STABLE FOR THE NEXT 24 HOURS. AT THE SURFACE...A TROUGH OF LOW
PRESSURE WILL PASS THROUGH THE AREA FRIDAY EVENING AND VEER THE
WINDS AROUND FROM 5 TO 15KTS SOUTHWESTERLY TO 5 TO 15 KTS NORTHWESTERLY.
NO PRECIPITATION IS EXPECTED WITH THE FRONTAL PASSAGE AND
CONDITIONS WILL REMAIN WELL WITHIN VFR LIMITS. MARTIN
&&
.CLIMATE...
APRIL CAME UP A BIT WET FOR THE WESTERN ZONES AND NEAR NORMAL
TO THE EAST. A GRAPHIC EXPLAINING THIS A BIT WAS POSTED ON OUR
FACEBOOK PAGE THIS MORNING. TFJ
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
857 AM MDT FRI MAY 1 2015
.UPDATE...
MADE JUST A FEW ADJUSTMENTS TO THE GOING FORECAST. A DRY ZONAL
FLOW WITH A JET TO THE N WAS OVER THE FORECAST AREA THIS MORNING.
JET WAS BRINGING SOME CLOUDINESS TO FAR NORTHERN SECTIONS PER
SATELLITE IMAGERY...SO ADJUSTED SKY COVER TO MATCH UP WITH
SATELLITE TRENDS. SOME CLOUDS WILL MOVE IN THIS AFTERNOON AS
WELL...AS A WEAK SHORTWAVE MOVES INTO THE AREA. FORECAST HAS THIS
COVERED WELL. THE RAP SOUNDINGS SHOWED A VERY DRY AIRMASS THROUGH
JUST ABOUT THE ENTIRE COLUMN THROUGH THIS AFTERNOON WHICH WILL
ALLOW FOR GOOD MIXING. LOWERED DEWPOINTS A FEW DEGREES AND
INCREASED WIND SPEEDS A BIT. SOME AFTERNOON GUSTS ABOVE 20 MPH ARE
POSSIBLE. TEMPERATURES WERE IN GOOD SHAPE BASED ON THE EXPECTED
MIXING.
A COLD FRONT WILL MOVE S THROUGH THE AREA ON SAT AND GENERATE
ISOLATED MOUNTAIN SHOWERS WITH POSSIBLE THUNDERSTORMS. ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND SAT...
QUIET WEATHER PATTERN FOR THE MOST PART CAN BE EXPECTED FOR THE
NEXT COUPLE OF DAYS ACROSS OUR FORECAST AREA. A FAST ZONAL FLOW
ALOFT WILL MOVE ACROSS OUR AREA TODAY AND THROUGH MOST OF SATURDAY
BEFORE THE FLOW BECOMES A BIT NORTHWEST BY LATE SATURDAY. SKIES
WILL BE MOSTLY SUNNY TODAY WITH ABOVE NORMAL TEMPERATURES AS
READINGS WILL WARM INTO THE MIDDLE TO UPPER 70S FOR MOST
LOCATIONS.
A COLD FRONT DROPS SOUTH ACROSS THE AREA SATURDAY AFTERNOON
BRINGING A WIND SHIFT TO THE NORTHWEST THEN NORTHEAST BY SATURDAY
NIGHT. MODELS DON`T SHOW MUCH IN THE WAY OF MOISTURE ASSOCIATED
WITH THE FRONT BUT WE CAN`T RULE OUT AN ISOLATED SHOWER.
TEMPERATURES AGAIN WILL BE QUITE WARM WITH READINGS IN THE MIDDLE
TO UPPER 70S AND POSSIBLY AN 80 DEGREE READING FOR SOME AREAS
SATURDAY AFTERNOON. HOOLEY
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
THE DISPARITY BETWEEN THE MODEL SOLUTIONS FOR THE LOW MIDWEEK
NEXT WEEK CONTINUES...IF NOT HAS WIDENED A LITTLE. THE GFS
CONTINUES TO TRACK THE LOW SOUTH OVER NEVADA AND ARIZONA...THE
ECMWF TRACKS THE LOW ACROSS SOUTHERN CANADA. THE 12Z RUN OF THE EC
HAD BETTER AGREEMENT WITH THE GFS SOLUTIONS...BUT WITH THE 00Z RUN
HAS SINCE BACKED OFF THE PREVIOUS TRACK.
GIVEN THAT NONE OF THE SOLUTIONS ARE STABLE ENOUGH TO LEAN ONE
WAY OR THE OTHER...HAVE NOT MADE ANY MAJOR CHANGES TO THE
FORECAST. PRETTY MUCH KEPT POPS IN THE 30 TO 40 PERCENT RANGE.
ONE THING THAT DOES LOOK LIKELY IS A GENERAL COOLING TREND DURING
THE SECOND HALF OF THE WEEK. THE QUESTION OF HOW MUCH REMAINS
UNCERTAIN. KEPT TEMPERATURES MAINLY IN THE LOWER 60S..MAYBE
TRENDING A DEGREE OR TWO COOLER.
FOR THE FIRST HALF OF THE WEEK...THE AREA WILL REMAIN IN FAST
WESTERLY FLOW. SEVERAL WEAK WAVES WILL QUICKLY MOVE ACROSS THE
AREA. THIS WILL KEEP CHANCES FOR RAIN. THE BEST CHANCES WILL BE
IN THE HIGHER TERRAIN...BUT SCATTERED SHOWERS AND THUNDERSTORMS
ARE POSSIBLE OUT ONTO THE PLAINS. REIMER
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL AT ALL TERMINALS TODAY. WIND GUSTS
MAY APPROACH 20 MPH NEAR KLVM AND KBIL BY THIS AFTERNOON...BUT
SHOULD DWINDLE BY THE EVENING HOURS. SINGER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 078 048/078 045/066 043/070 045/076 047/067 042/060
0/U 00/B 22/T 32/T 22/T 23/W 33/W
LVM 075 039/075 036/068 037/071 040/075 040/065 037/059
0/U 02/T 13/T 32/T 23/T 33/W 33/W
HDN 082 043/083 041/069 042/071 043/077 045/070 041/061
0/U 00/B 21/B 32/T 22/T 23/W 33/W
MLS 077 048/079 044/066 042/067 045/074 047/068 042/063
0/U 00/B 21/B 32/T 12/T 23/W 33/W
4BQ 078 043/081 043/068 043/065 045/071 047/067 041/062
0/U 00/U 11/B 33/T 22/T 33/W 33/W
BHK 078 044/078 041/064 039/061 041/069 045/065 040/061
0/U 00/B 21/B 33/T 11/N 23/W 33/W
SHR 075 039/077 040/066 039/067 041/070 040/064 040/057
0/U 00/U 12/T 33/T 23/T 33/W 33/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
620 AM CDT FRI MAY 1 2015
.SHORT TERM...(TODAY)
ISSUED AT 341 AM CDT FRI MAY 1 2015
PCPN CHANCES/PCPN COVERAGE AND TEMPERATURES WILL PROVIDE THE MAIN
FORECAST CHALLENGES FOR THE TODAY PERIOD.
REGIONAL RADAR LOOP EARLY THIS MORNING SHOWED SHOWERS AND A FEW
EMBEDDED THUNDERSTORMS OCCURRING IN ASSOCIATION WITH A WEAK COLD
FRONT MOVING EASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS. THIS
FRONT SHOULD STALL OUT AND THEN WASH OUT THIS EVENING. LATEST SHORT
RANGE HIGH RESOLUTION MODELS ARE IN DECENT AGREEMENT SHOWING SOME
SCATTERED AND MAINLY LIGHT PCPN MOVING ACROSS THE FORECAST AREA THIS
MORNING. 06Z RAP SEEMED TO HAVE A FAIRLY GOOD HANDLE ON THE PATTERN.
LOOK FOR HIGHS MOSTLY IN THE LOWER AND MID 70S BUT A FEW LOCATIONS
IN WEST CENTRAL IOWA MAY ONLY REACH NEAR 70.
MILLER
SHORT TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 341 AM CDT
FRI MAY 1 2015
FOCUS FOR POSSIBLE PCPN SHIFTS TO THE SRN CWA TONIGHT AND SATURDAY
MORNING WHERE 310K UPGLIDE AND LOW COND PRES DEF WILL BE MOST
PREVALENT.
NEXT ROUND OF PCPN ASSOCIATED WITH A COLD FRONT DROPPING THRU THE
DAKOTAS/UPPER MID WEST SATURDAY NIGHT THE INTO THE CWA ON SUNDAY.
MODELS HOLD OFF DEVELOPMENT UNTIL AFTN WHEN ENVIRONMENT BECOMES
ADEQUATELY UNSTABLE...THEN INCREASES IN AREAL COVERAGE AND
INTENSITY SUNDAY NIGHT IN RESPONSE TO STRENGTHENING BNDRY LYR
MOISTURE CONVERGENCE. WITH RELATIVELY HIGH CONCENTRATION OF
ENVIRONMENTAL MOISTURE AND PERSISTENT FORCING...CONDITIONS WILL
BE FAVORABLE FOR SOME LOCATIONS TO SEE RAINFALL AMOUNTS OF HALF
AND INCH OR SO.
DEE
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI MAY 1 2015
SFC BNDRY AT THIS POINT PROGGED TO BECOME NEARLY STATIONARY MONDAY
MORNING THRU TUESDAY MORNING. PERSISTENT INFLUX OF GULF MOISTURE
COUPLED WITH MOIST BNDRY LYR CONVERGENCE/INSTABILITY AXIS SITUATED
OVER THE CWA WOULD SUGGEST CONDITIONS WILL AGAIN BE FAVORABLE FOR
SIGNIFICANT RAINFALL ACCUMULATIONS. TUESDAY AFTN THRU THURSDAY
NIGHT PCPN ACCUMULATIONS BEING DRIVEN BY EXTENDED PERIOD OF 305K
UPGLIDE/PRESIDENT LLVL MOISTURE ADVECTION. OTHERWISE...METEOGRAMS
STILL SHOWING MODERATE COOL NEXT WEEK IN LIGHT OF SFC BNDRY MOVING
IN.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 620 AM CDT FRI MAY 1 2015
SOME CEILINGS AROUND 5000 FEET AND VSBYS IN THE MVFR CATEGORY WILL
BE POSSIBLE INTO THIS EVENING WITH SCATTERED SHRA. DID NOT MENTION
THUNDER WITH THE 12Z TAFS BECAUSE ANYTHING SHOULD BE ISOLATED. WE
CAN AMEND THE TAFS IF CONFIDENCE INCREASES. WINDS WILL BE MAINLY
LESS THAN 12 KNOTS.
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER/DEE
LONG TERM...DEE
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1034 AM EDT FRI MAY 1 2015
.SYNOPSIS...LOW PRESSURE WILL LINGER OVER AND JUST OFF THE CAROLINA
COAST TODAY... AS A STRONG UPPER LEVEL DISTURBANCE CROSSES THE
REGION. THE LOW AND DISTURBANCE WILL MOVE OFFSHORE LATE TONIGHT...
AND HIGH PRESSURE WILL BUILD IN FROM THE WEST OVER THE WEEKEND.
&&
.NEAR TERM /TODAY/...
AS OF 1030 AM FRIDAY...
THE INTENSITY OF THE RAIN OVER THE CENTRAL PIEDMONT EARLIER THIS
MORNING HAS DECREASED AS IT PUSHES SOUTH INTO THE SOUTHERN PIEDMONT
AND SANDHILLS. AN UPPER LOW WITHIN A LARGER POSITIVELY TILTED UPPER
TROUGH IS ROTATING OVERHEAD...AND THE MAIN LOBE OF STRONG VORTICITY
RESPONSIBLE FOR THAT BATCH OF RAIN IS SHIFTING MORE TOWARD SC AND
SOUTHEAST NC. MORNING OBS ANALYSIS SHOWS ANOTHER...WEAKER SHORTWAVE
NORTH OF THE LOW THAT WILL ROTATE OUR WAY THIS AFTERNOON...ALONG
WITH 30-35KT OF 850MB FLOW THAT WILL ENHANCE LOW-LEVEL CONVERGENCE.
SPC TROPOSPHERIC LAPSE RATES ARE STILL RELATIVELY STEEP WITHIN THE
UPPER LOW...WITH AN AXIS AREA OF NEAR -7C STRETCHING FROM WSW TO ENE
ACROSS THE AREA....SO SOME WEAK INSTABILITY MAY DEVELOP AGAIN THIS
AFTERNOON...THOUGH THE WIDESPREAD AND CONTINUED FEED OF RAIN FROM
THE NORTHEAST WILL LIKELY INHIBIT WARMING MORE THAN YESTERDAY.
THUS...EXPECT MAINLY SHOWERS THIS AFTERNOON BECOMING INCREASINGLY
FOCUSED EAST OF US 1. THE LATEST HRRR SHOWS SOME DEEPER CONVECTION
FIRING ACROSS THE SOUTHERN COASTAL PLAIN AFTER 18Z...AND WITH THE
FREEZING LEVEL BELOW 6K FT ON THE KGSO RAOB AND THE -10C TO -20C
LAYER CENTERED AROUND 15K FT...SOME SMALL HAIL CANT BE COMPLETELY
RULED OUT. HOWEVER...THE PROBABILITY SEEMS VERY LOW AT THIS POINT.
CURRENT TEMP FORECAST LOOKS PRETTY REASONABLE WITH LIMITED
WARMING...STRONGEST ACROSS THE SOUTHERN PIEDMONT THIS AFTERNOON AS
PRECIP MOVES OFF TO THE EAST....WITH UPPER 50S NORTHEAST TO SOME MID 60S
SOUTHWEST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 255 AM FRIDAY...
TONIGHT: EXPECT SLOW CLEARING WITH MODEST BUT DEEP SUBSIDENCE AND
DRYING IN THE WAKE OF THE EXITING LOW. SURFACE WINDS WILL BECOME
FAIRLY LIGHT FROM THE NNW WHILE 950-850 MB WINDS WILL BE MAINLY FROM
THE NNE... ALLOWING ATLANTIC MOISTURE TO CONTINUE TO SPILL IN ON THE
NW SIDE OF THE LOW... SO SCATTERED STRATOCU MAY LINGER WELL INTO THE
NIGHT. LOWS 45-50 WITH WEAK COOL AIR ADVECTION AS SURFACE HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST... BUT INITIALLY GETS
HELD UP BY THE MOUNTAINS.
SAT/SAT NIGHT: MOSTLY DRY AND QUIET WEATHER IS EXPECTED. A BAND OF
ISOLATED SHOWERS IS EXPECTED OVER THE NRN/ERN PORTIONS OF CENTRAL NC
IN THE AFTERNOON... AS A NOSE OF ENHANCED PW AND WEAK VORTICITY
DROPS TO THE SSE AROUND THE WEST SIDE OF THE OFFSHORE LOW. MOISTURE
IS UNIMPRESSIVE HOWEVER... WITH VERY SMALL FORECAST MUCAPE... SO
WILL MAINTAIN JUST ISOLATED COVERAGE... FOCUSED ON THE NW PIEDMONT
AND NRN/CENTRAL COASTAL PLAIN... AS SUGGESTED BY THE HI-RES WRF
MODEL RUNS. EXPECT MOSTLY CLEAR SKIES SAT NIGHT WITH WINDS BECOMING
LIGHT/VARIABLE AS THE CENTER OF THE SURFACE HIGH SHIFTS OVERHEAD.
HIGHS 71-76 NE TO SW... AND LOWS IN THE UPPER 40S TO LOWER 50S. -GIH
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
THE LONG TERM WILL FEATURE WARM AND DRY CONDITIONS WITH OUR FIRST
REAL STRETCH OF 80 DEGREE DAYS OF THE YEAR. THE PATTERN WILL FEATURE
SURFACE HIGH PRESSURE OFFSHORE WITH WEAK SOUTHERLY RETURN FLOW
ACROSS CENTRAL NC. THE NORTHWESTERLIES ALOFT WILL WEAKEN
CONSIDERABLY TO VERY LIGHT WINDS FOR THE FIRST HALF OF THE WEEK. IN
FACT THE GFS FORECAST SOUNDING FOR GREENSBORO ON MONDAY AFTERNOON
HAS LESS THAN 10 KTS OF WIND ALL THE WAY UP THROUGH 200 MB. WHILE
THE TEMPERATURES WILL FEEL VERY WARM IN CONTRAST TO WHAT WE HAVE
BEEN EXPERIENCING THIS PAST WEEK...THE LOW TO MID 80S WILL ONLY BE
ABOUT 5 DEGREES ABOVE NORMAL FOR THIS TIME OF THE YEAR AND NOT EVEN
CLOSE TO APPROACHING RECORDS AS THESE ARE ALL IN THE LOW TO MID 90S.
LOWS WILL BE IN THE UPPER 50S TO LOW 60S.
NOT MUCH IN THE WAY OF PRECIPITATION IS EXPECTED DURING THE PERIOD
BUT SOME CONVECTION ASSOCIATED WITH A TROUGH NORTHWEST OF THE AREA
COULD IMPINGE ON THE TRIAD ON WEDNESDAY AND THURSDAY AFTERNOONS BUT
COVERAGE...AND DURATION SHOULD BE MINIMAL AS MOST ACTIVITY SHOULD
REMAIN NORTH OF THE AREA.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 655 AM FRIDAY...
MVFR TO IFR CONDITIONS WILL DOMINATE CENTRAL NC TAFS THROUGH THIS
MORNING... FOLLOWED BY SLOW IMPROVEMENT TO VFR MID-LATE FRI
AFTERNOON (AFTER 20Z). A STRONG UPPER LEVEL LOW MOVING OVER THE
REGION THROUGH TODAY WILL BRING UNSETTLED WEATHER WITH MVFR CIGS
COMMON AT ALL SITES... AND PERIODS OF VFR-MVFR VSBYS IN SHOWERS...
FROM MORNING THROUGH THE MID AFTERNOON HOURS. CIGS MAY DROP TO IFR
FOR A FEW HOURS EARLY THIS MORNING BETWEEN 07Z AND 13Z. AN ISOLATED
THUNDERSTORM OR TWO IS ALSO POSSIBLE ESPECIALLY AT THE EASTERN
TERMINALS OF RDU/RWI/FAY 14Z-20Z TODAY... BUT THE THUNDER COVERAGE
SHOULD BE TOO LOW TO MENTION IN THE TAFS. WINDS WILL INCREASE THIS
MORNING FROM THE NORTH OR NE AT 10-14 KTS GUSTING UP TO 20 KTS...
THEN DROP BACK UNDER 10 KTS AFTER 22Z. VFR CONDITIONS ARE LIKELY
THIS EVENING ON THROUGH TONIGHT.
LOOKING BEYOND 12Z SAT MORNING: VFR CONDITIONS LIKELY SAT MORNING
THROUGH TUE... AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE
WEST... SHIFTING OVERHEAD LATE IN THE WEEKEND AND MOVING OFFSHORE
EARLY NEXT WEEK. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/22
SHORT TERM...HARTFIELD
LONG TERM...ELLIS
AVIATION...HARTFIELD
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
930 AM CDT FRI MAY 1 2015
.UPDATE...
SHOWERS OVER MINNESOTA AND IOWA ASSOCIATED WITH A SHORTWAVE WILL
MOVE EASTWARD INTO WISCONSIN TODAY. MODELS CONTINUE TO SUGGEST
THAT THE SHOWERS WILL MAINLY FALL APART...THOUGH A FEW MAY SURVIVE
AS THE SHORTWAVE MOVES THROUGH. WILL CONSIDER ADDING LOW POPS OR
SPRINKLES TO THE FORECAST FOR LATE AFTERNOON AND
EVENING...DEPENDING ON RADAR TRENDS LATER ON.
TEMPERATURES ARE ON TRACK FOR FORECAST HIGHS...SO NO SIGNIFICANT
FORECAST UPDATES ARE EXPECTED FOR THE REMAINDER OF THE DAY.
&&
.AVIATION/18Z TAFS/...
VFR CONDITIONS WILL PERSIST THROUGH SATURDAY. COULD SEE A FEW
SHOWERS OR SPRINKLES ARRIVE LATE AFTERNOON INTO THIS EVENING...BUT
EXPECTING UPSTREAM AREA OF RAIN TO MAINLY FALL APART AS IT HEADS
EASTWARD TODAY. MODELS SHOWING A STRAY SHOWER OR TWO POSSIBLE
SATURDAY...BUT MOST PLACES SHOULD REMAIN DRY THROUGH TOMORROW.
WINDS WILL TURN EAST TO SOUTHEAST NEAR LAKE MICHIGAN LATE THIS
MORNING INTO THE AFTERNOON. WILL HAVE TO WATCH FOR A POSSIBLE WIND
SHIFT SATURDAY AFTERNOON NEAR THE LAKE...DEPENDING ON HOW STRONG
PREVAILING SOUTHWEST WINDS ARE. BEST CHANCE FOR SOUTH TO SOUTHEAST
WINDS LOOKS TO BE NORTH OF MILWAUKEE.
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT FRI MAY 1 2015/
TODAY...FORECAST CONFIDENCE IS HIGH.
DRY AND SUNNY TO START THE DAY WITH HIGH PRESSURE OVER REGION.
SLOWLY INCREASING HIGH TO MID LEVEL CLOUDS FROM THE WEST WITH
APPROACHING SHORT WAVE TROUGH.
BRIEF PERIOD OF STRONG UPPER LIFT WITH CVA AHEAD OF SHORT MOVES
INTO THE WEST BETWEEN 21Z AND 00Z. NAM AND RAP SOUNDINGS/CROSS
SECTIONS DEPICTING A DEEPER MOIST LAYER ABOVE 10K FT THAN GFS
COINCIDENT WITH THIS LIFT...BUT ALL FORECAST SOUNDINGS ARE VERY
DRY BELOW 10K FEET...REFLECTING THE DRY LOWER LEVEL AIR IN PLACE
WITH THE HIGH.
CURRENT SHOWERS IN THE EASTERN DAKOTAS WITHIN NARROW RIBBON OF
MOISTURE RETURN/POOLING LIMITED TO RIGHT ALONG THE SURFACE TROUGH.
BUT SURFACE TROUGH WASHES OUT AS IT MOVES TOWARD WESTERN
WISCONSIN...WITH AN ATTENDANT SHARP REDUCTION IN FRONTOGENETIC
FORCING,
ADDED ISOLATED SPRINKLES IN THE FAR WEST MORE FOR
COLLABORATION... BUT WILL BE HARD TO GET ANY PRECIPITATION TO
REACH THE SURFACE THROUGH THE DEEP DRY LAYER AND WEAKENING
FORCING.
SLOWLY RISING 925 MB TEMPERATURES WILL YIELD HIGHS AROUND 70 IN
SOUTH CENTRAL WISCONSIN...WITH MID TO UPPER 60S OVER SOUTHEAST
WISCONSIN AWAY FROM THE LAKE...WITH WEAK GRADIENT ALLOWING A LIGHT
LAKE BREEZE THAT KEEPS AREAS WITHIN 5-10 MILES OF THE LAKE IN THE
50 TO 60 DEGREE RANGE.
TONIGHT...FORECAST CONFIDENCE IS HIGH.
DECENT UPPER LEVEL LIFT CROSSES REST OF THE REGION WITH SHORT
WAVE THIS EVENING...BUT LAYERS BELOW 5K FEET NEVER SATURATE...AND
LOWER LEVEL FORCING WEAKENS RAPIDLY AHEAD OF TROUGH. WILL KEEP
TONIGHT DRY WITH ONLY CLOUDS MARKING THE PASSAGE OF THE TROUGH.
THE MOSTLY CLOUDY SKIES AND WEAK WARM ADVECTION ON SOUTHERLY WINDS
WILL KEEP LOWS IN THE MID-UPPER 40S...WITH A FEW 50 DEGREE LOWS IN
THE WEST.
SHORT TERM...SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
MODELS ARE IN GOOD AGREEMENT WITH WARM AIR ADVECTION LINGERING
ACROSS THE AREA DURING THIS PERIOD. INCREASING SOUTH TO SOUTHWEST
WINDS ARE EXPECTED...BRINGING WARM TEMPERATURES TO MOST OF THE
AREA. ONSHORE WINDS NORTH OF PORT WASHINGTON MAY KEEP COOLER
TEMPERATURES THERE. HIGHS SHOULD REACH INTO THE 70S ON
SATURDAY...WITH HIGHS IN THE MID 70S TO AROUND 80 ON SUNDAY.
MOISTURE IS MEAGER SATURDAY INTO SATURDAY NIGHT ACROSS THE
AREA...SO NOT EXPECTING MUCH IN THE WAY OF PRECIPITATION...DESPITE
WARM AIR ADVECTION AND WEAK 500 MB VORTICITY MAXIMUM PASSING SOUTH
OF THE AREA. SUNDAY MAY END UP DRY AS WELL...WITH BEST UPWARD
VERTICAL MOTION AND MOISTURE COMBINATION NOT ARRIVING UNTIL SUNDAY
NIGHT...AS THE COLD FRONT APPROACHES FROM THE NORTHWEST.
KEPT SOME POPS FOR SUNDAY FOR NOW...BUT MAY NEED TO BE LOWERED OR
REMOVED IN LATER FORECASTS. KEPT LIKELY POPS FOR SUNDAY
NIGHT...WHICH MAY NEED TO BE RAISED IN LATER FORECASTS. AREA
FORECAST SOUNDINGS SUGGEST 500 TO 1000 J/KG MEAN LAYER OR ELEVATED
CAPE...THOUGH DEEP LAYER SHEAR IS MODEST AT BEST. SPC KEPT
MARGINAL SEVERE RISK NORTHWEST OF THE AREA SUNDAY...CLOSER TO THE
FRONT. SHOULD BRING SOME NEEDED RAINFALL TO THE AREA.
LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF/GFS IN DECENT AGREEMENT WITH TAKING COLD FRONT INTO NORTHERN
ILLINOIS MONDAY...STALLING OUT MONDAY NIGHT INTO TUESDAY...BEFORE
SHIFTING BACK NORTH AS A WARM FRONT TUESDAY NIGHT INTO WEDNESDAY.
KEPT POPS GOING FOR THIS PERIOD...THOUGH THERE MAY BE MORE BREAKS
DURING THIS TIME. GFS WAS SHOWING WEAK CAPE...SO HAVE SOME SLIGHT
CHANCES FOR THUNDER GOING IN FORECAST. TEMPERATURES RETURN CLOSER
TO SEASONAL NORMALS...WITH ONSHORE WINDS NEAR THE LAKE.
MODELS DIFFER MORE INTO THURSDAY...THOUGH BOTH SHOWING SOME WARM
AIR ADVECTION DEVELOPING INTO THE AREA. USED CONSENSUS POPS AND
TEMPERATURES FOR WEDNESDAY NIGHT INTO THURSDAY FOR NOW.
AVIATION/12Z TAFS/...
VFR CONDITIONS THROUGH THE FORECAST WITH HIGH PRESSURE DOMINATING
THE FORECAST. WILL SEE INCREASING VFR CLOUDS...MAINLY ABOVE 10K
FT...MOVE FROM WEST TO EAST THIS AFTERNOON INTO THIS EVENING
WITH A WEAK UPPER LEVEL WAVE...BUT CLOUD DECK WILL NOT LOWER MORE
THAN 5K FEET WITH NO PRECIPITATION EXPECTED.
FIRE WEATHER...
MAX TEMPERATURES WEST OF THE KETTLE MORAINE WILL RANGE BETWEEN 65
AND 70 DEGREES...WITH MINIMUM RELATIVE HUMIDITY VALUES OF 25 TO 30
PERCENT WEST OF A RIPON...WATERTOWN TO DELAVAN LINE. SW WINDS WILL
BE BETWEEN 8 AND 10 MPH...WITH GUSTS BELOW 15 MPH THIS AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...DDV
TODAY/TONIGHT AND AVIATION/FIRE WEATHER...REM
SATURDAY THROUGH THURSDAY...WOOD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
259 PM MDT FRI MAY 1 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 257 PM MDT FRI MAY 1 2015
...STORMS MOVING INTO EASTERN COLORADO THIS EVENING...
...WARM WEEKEND ON THE WAY...
LATEST HRRR HAS A DECENT HANDLE ON THE CONVECTION...AND ALONG WITH
OTHER HI-RES GUIDANCE SHOWS A WAVE OF CONVECTION INCREASING IN
COVERAGE OVER THE I-25 CORRIDOR THIS AFTERNOON...THEN CLEARING I-25
BY 00-01Z THIS EVENING. STORMS WILL THEN CONSOLIDATE INTO AN MCS
OVER THE ERN PLAINS THIS EVENING. THEN...SHOULD SEE SHOWERS AND
STORMS MOVING INTO WRN KS BY 03Z OR SO THIS EVE. AFTER 06Z...PRECIP
SHOULD BE OVER FOR MOST OF THE AREA...WITH JUST SOME LINGERING
SHOWERS POSSIBLE OVER THE FAR ERN PLAINS AND HYR TRRN. UPPER RIDGE
AND ASSOCIATED AVA SHOULD HELP SUPPRESS THINGS THROUGH SAT MORNING.
TOMORROW...A WARMER DAY IS IN STORE...AS FLOW BECOMES A BIT MORE
ZONAL AND H7 TEMPS RISE TO AROUND 10 DEG C. EXPECT 80 PLUS DEG
TEMPS OVER MUCH OF THE PLAINS BY AFTERNOON...WITH 60S AND 70S FOR THE
HIGHER ELEVATIONS. ANOTHER WEAK DISTURBANCE WILL SPARK SOME AFTERNOON
STORMS MOVING OFF THE MTS SAT AFTERNOON...BUT WITH DEW POINTS IN
THE 30S CONVECTION WILL NOT BE AS STRONG AS IT IS/WILL BE
TODAY...AND COVERAGE A BIT LESS AS WELL. ROSE
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 257 PM MDT FRI MAY 1 2015
A RATHER WET PERIOD IS EXPECTED THE FIRST PART HALF OF NEXT WEEK.
ON SUN AN UPR TROF WL MOVE TO ALONG THE CA COAST...WITH MSTR AHEAD
OF THIS SYSTEM MOVING INTO THE FORECAST AREA...ALONG WITH A
SHORTWAVE TROF IN THE AFTERNOON AND EVENING HOURS. IT STILL LOOKS
LIKE A FRONT WL HANG UP ALONG THE PALMER DVD SUN AFTERNOON AND THEN
WORK ITS WAY SOUTH IN THE EVENING HOURS. MUCH OF THE AREA WL SEE AT
LEAST ISOLD TO SCT SHOWERS AND TSTMS SUN AND SUN EVENING. HIGH TEMPS
ON SUN SHOULD STILL BE ABOVE AVERAGE BY ABOUT 5-10 DEG.
ON MON THE UPR TROF MOVES INTO THE WRN STATES...WITH AN UPR LOW
CENTER EXPECTED TO BE OVR SWRN AZ BY 00Z TUE. MSTR WL CONTINUE
STREAMING INTO THE FORECAST AREA AHEAD OF THIS SYSTEM. OVR ERN
PORTIONS OF THE FORECAST AREA...LOW TO MID LEVEL SERLY WINDS SHOULD
HELP ENHANCE PCPN CHANCE ALONG AND ADJACENT TO THE ERN MTNS.
WIDESPREAD PCPN IS EXPECTED ON MON ALONG WITH COOLER TEMPS. THE
ECMWF AND GFS LIFT THE UPR LOW NORTHEASTWARD ON TUE. THE GFS IS A
LITTLE FARTHER NORTH THAN THE GFS WITH THE LOW CENTER. THE GFS HAS
IT IN NERN CO BY 00Z WED WITH THE ECMWF SHOWING IT OVR SERN CO.
EITHER WAY...WIDESPREAD PCPN SHOULD CONTINUE THRU TUE.
THIS SYSTEM WEAKENS AS IT MOVES NORTH-NORTHEASTWARD TUE NIGHT
THROUGH WED...MOVING INTO THE WRN DAKOTAS BY 00Z THU. ALTHOUGH PCPN
CHANCES ARE EXPECTED TO DECREASE SOME TUE NIGHT...THERE SHOULD STILL
BE PLENTY OF MSTR AROUND FOR AN INCREASE IN ACTIVITY IN THE
AFTERNOON AND EVENING HOURS ON WED AS THINGS REMAIN UNSETTLED.
TEMPS REMAIN QUITE WARM AS THIS SYSTEM AFFECTS THE AREA AND SNOW
ACCUMULATIONS ARE GENERALLY EXPECTED TO REMAIN OVR THE HYR MTN
AREAS. SOME AREAS...ESPECIALLY NR THE ERN MTN...COULD SEE PERIODS
OF HEAVY RAIN.
ANOTHER UPR LOW IS THEN FORECAST TO MOVE INTO THE GREAT BASIN FOR
LATE THU AND FRI. THIS WL KEEP THE WX UNSETTLED WITH PROBABLY FAIRLY
WIDESPREAD PCPN CHANCES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 257 PM MDT FRI MAY 1 2015
MAIN CONCERN WILL BE FROM NOW THROUGH ABOUT 02Z THIS EVENING...AS A
BROKEN LINE OF STORMS MOVES EWD ACROSS THE I-25 CORRIDOR. COULD SEE
SOME BRIEF IFR-MVFR IN STRONGER CELLS DURING THIS TIME...WITH BRIEF
RA+ AND POSSIBLY SOME SMALL GR. STORMS WILL CONSOLIDATE OVER THE
SERN CO PLAINS THIS EVENING BEFORE MOVING ON INTO WRN KS TONIGHT.
THERE IS A SLIGHT CHANCE SOME PATCHY LOW CIGS OR BR COULD DEVELOP
VC KCOS OR KPUB AFTER 03Z TONIGHT...DEPENDING ON THE EXTENT OF
STORMS LATER THIS AFTERNOON AND EVENING. BUT ANY IMPACT SHOULD BE
MINIMAL...WITH VFR CONDITIONS EXPECTED TO PERSIST THROUGH SATURDAY.
STORMS SAT AFTERNOON SHOULD NOT BER AS WIDESPREAD OR STRONG AS THE
STORMS TODAY. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ROSE
LONG TERM...28
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1028 AM MDT FRI MAY 1 2015
.UPDATE...
ISSUED AT 1028 AM MDT FRI MAY 1 2015
WILL BE UPDATING THE FORECAST TO INCREASE THE THUNDERSTORMS TO THE
LIKELY CATEGORY ON THE PALMER DIVIDE AND EASTERN PLAINS DURING THE
AFTERNOON AND EVENING. SATELLITE PICTURES SHOW THAT THE STRATUS
ALONG THE FOOTHILLS IS THICKEST FROM THE NORTHWEST SIDE OF DENVER
TO THE WYOMING BORDER. THIS IS LEAVING THE PALMER DIVIDE IN NEARLY
FULL SUNSHINE. THE STRONGER HEATING OVER THE PALMER DIVIDE WILL
CAUSE THE AIRMASS TO DE-STABILIZE THERE FIRST. THE LATEST RUNS OF
THE HRRR AND RAP SHOW THE STRONGEST CONVECTION DEVELOPING OVER
DOUGLAS COUNTY BY SHORTLY AFTER 18Z. THE MORNING SOUNDING SHOWED A
PRECIPITABLE WATER OF .66 INCHES WHICH IS JUST SHORT OF THE RECORD
FOR MAY 1. SHOULD SEE A GOOD ROUND OF SHOWERS DEVELOP EARLY IN
THE AFTERNOON WHICH WILL DRIFT EASTWARD. THE OTHER MAIN AREA OF
PRECIPITATION IS EXPECTED TO DEVELOP OVER THE CHEYENNE RIDGE AFTER
ABOUT 21Z WHICH WILL MOVE OVER THE NORTHERN PLAINS ZONES THROUGH
THE EVENING. WITH CAPE VALUES IN THE 1000-1500 J/KG RANGE THIS
AFTERNOON...STORMS MAY GET STRONG ENOUGH TO PRODUCE SOME HAIL
CLOSE TO 1 INCH IN DIAMETER. OTHERWISE...THEY WILL PRODUCE BRIEF
HEAVY RAIN AND SOME GUSTY WINDS. MOST THUNDERSTORM ACTIVITY ALONG
THE FRONT RANGE SHOULD BE DONE BY EARLY EVENING...WITH THE FOCUS
OF CONVECTION THROUGH THE EVENING OUT ON THE NORTHEAST PLAINS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 337 AM MDT FRI MAY 1 2015
MUCH OF THE SHOWERS HAVE DISSIPATED OVER THE NORTHEAST PLAINS WITH
JUST A FEW LIGHT SHOWERS EXITING WASHINGTON AND PARK COUNTIES.
STILL QUITE A BIT OF STRATUS AROUND AT VARIOUS LEVELS AND IS NOT
WIDESPREAD OR UNIFORM. NO FOG BEING REPORTED YET BUT STILL EXPECT
SOME PATCHY FOG STILL TO DEVELOP OVER LOW LYING AREAS AS SOME
T/TD SPREADS ARE ONLY 2-5 DEGREES.
COLORADO WILL BE UNDER A MODERATE WESTERLY FLOW ALOFT TODAY
FOLLOWING LAST NIGHTS DISTURBANCE WITH STILL SOME UPSTREAM
MOISTURE TO WORK WITH. MOST IMPRESSIVE IS THE INCREASE IN PW
VALUES OVER THE PAST 24 HOURS...WITH INCREASES OVER .40" OVER THE
FRONT RANGE WITH READINGS AROUND .75" FROM INTEGRATED PW FROM GPS.
SHOULD SEE ANOTHER ROUND OF AFTERNOON/EVENING THUNDERSTORMS TODAY
GIVEN AMPLE MOISTURE AS SURFACE DEWPOINTS SHOULD REMAIN IN THE
40S. THIS WILL RESULT IN SURFACE BASED CAPES FROM 800-1500J/KG.
THERE IS SOME INITIAL STABILITY WITH LOW LEVEL INVERSIONS AROUND
750MB THIS AM WHICH MODELS EVENTUALLY ERODE BY LATE AFTERNOON.
EXPECT HIGHER COVERAGE OF STORMS TODAY OVER FRONT RANGE FOOTHILLS
AND PALMER DIVIDE AND LOWER COVERAGE OVER THE FAR PLAINS AS HIGHER
STABILITY REMAINS. GIVEN CAPE VALUES AND THE INCREASE SHEAR ALOFT
COULD BE A FEW SEVERE STORMS WITH HAIL UP TO ONE INCH IN DIAMETER
AND DAMAGING WINDS. NOT MUCH HELP UPSTAIRS TODAY AS QG VERTICAL
VELOCITY FIELDS INDICATE A NEUTRAL TO SLIGHTLY SUBSIDENT AIRMASS.
STORMS SHOULD FOLLOW DIURNAL TRENDS WITH MOST STORMS ENDING BEFORE
MIDNIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 337 AM MDT FRI MAY 1 2015
EXPECT THE UPPER RIDGE TO REMAIN ALOFT ON SATURDAY. AT THE
SURFACE...A TROUGH DIGGING ALONG THE EASTERN CO PLAINS WILL HELP
MIX OUT THE POST FRONTAL STABLE AIRMASS FOR MUCH WARMER
TEMPERATURES. SHOWERS AND STORMS ARE NOT EXPECTED TO FORM UNTIL
THE AFTERNOON WITH SOME DECENT CAPE OVER THE FAR EASTERN PLAINS.
COULD SEE SOME STRONGER STORMS IN THE LATE AFTERNOON AND EARLY
EVENING OUT THAT WAY.
ANOTHER COLD FRONT IS PROGGED TO PUSH DOWN THE PLAINS SUNDAY
COMBINED WITH MOISTURE ADVECTING UP FROM NEAR BAJA. LOOK FOR
COOLER TEMPERATURES AND AN INCREASE IN SHOWER AND STORM COVERAGE.
AN UPPER LOW WILL DIG DOWN OVER SRN CALIFORNIA/BAJA SUNDAY NIGHT.
THIS UPPER LOW WILL PUSH EAST EARLY MONDAY THEN GET PICKED UP AND
BROUGHT NORTHEAST OVER THE STATE AS A LARGER LOW OVER THE PACIFIC
NORTHWEST MOVES ONSHORE TUESDAY. UPSLOPE FLOW FROM SUNDAY NIGHT IS
EXPECTED TO CONTINUE THROUGH TUESDAY AFTERNOON AS THE UPPER LOW
APPROACHES. THIS WILL BRING A VERY GOOD CHANCE FOR RAIN SHOWERS
AND THUNDERSTORMS TO THE AREA MONDAY THROUGH TUESDAY AFTERNOON.
HAVE PUT POPS IN THE HIGH CHANCE CATEGORY...WITH THE FAR EASTERN
PLAINS SEEING LIKELY POPS ON TUESDAY AFTERNOON. THEN AS THE UPPER
LOW PUSHES NORTHEAST OF THE AREA AND A SURFACE LOW FORMS OVER THE
EASTERN COLORADO PLAINS...CHANCES WILL START DECREASING FROM THE
SOUTH BUT WILL STILL SEE SHOWERS AROUND THROUGH WEDNESDAY. SYSTEM
WILL BE QUITE WARM WITH SNOW LEVELS REMAINING AROUND 10KFT.
PAST WEDNESDAY REMAINS AN UNCLEAR FORECAST...AS MODELS CONTINUE
TO STRUGGLE WITH THE EVOLUTION AND TRACK OF THE PACNW UPPER LOW.
MODELS HAD BEEN SEEMING TO TAKE A MORE SOUTHERLY TRACK...UNTIL THE
00Z EC CAME IN PUSHING IT BACK FARTHER NOR TH. HOWEVER...EITHER
WAY...MOISTURE WILL CONTINUE TO BE PRESENT WEDNEDAY INTO
THURSDAY...THE MODEL DIFFERENCES WILL MAINLY AFFECT TEMPERATURES.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 1028 AM MDT FRI MAY 1 2015
WILL MENTION THE BEST TIME FOR THUNDERSTORMS ACROSS THE DENVER
AREA AIRPORTS FROM 3 PM THROUGH ABOUT 7 PM. OVERNIGHT...THINGS
SHOULD CLEAR OUT NICELY WITH DECENT DRAINAGE WINDS WHICH SHOULD
KEEP FOG OR STRATUS FROM DEVELOPING. NO OTHER AVIATION IMPACTS ARE
EXPECTED AFTER THE ROUND OF AFTERNOON THUNDERSTORMS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DANKERS
SHORT TERM...ENTREKIN
LONG TERM...KRIEDERMAN
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
339 PM CDT FRI MAY 1 2015
.SYNOPSIS...
ISSUED AT 321 PM CDT FRI MAY 1 2015
WEAK FRONTAL BOUNDARY WILL DISSIPATE OVER IOWA TONIGHT AS A
FRONTAL BOUNDARY DEVELOPS TO THE NORTHWEST ON SATURDAY. THIS FRONT
WILL MOVE SOUTHEAST THROUGH THE AREA SUNDAY AFTERNOON AND NIGHT
BEFORE STALLING. THE OVERALL WEATHER PATTERN WILL BE ACTIVE WITH
THE FRONT IN THE VICINITY THROUGH THE NEXT WEEK.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 321 PM CDT FRI MAY 1 2015
MAIN FORECAST CONCERN WILL BE PRECIPITATION CHANCES THIS EVENING AND
AGAIN VERY LATE IN THE PERIOD. ONGOING PRECIPITATION ACROSS CENTRAL
PORTION OF THE CWA WILL PERSIST THROUGH THE EVENING...CONTINUING TO
PUSH SLOWLY SOUTHEAST. WEAK BOUNDARY AND FORCING WITH PRECIPITATION
WILL CONTINUE TO WEAKEN AND WILL SEE PRECIPITATION CONTINUE TO
BECOME MORE SCATTERED THROUGH THE LATE EVENING. HRRR MODEL HAS A
GOOD HANDLE ON PRECIPITATION TRENDS...AND HAVE TRENDED THIS WAY FOR
POPS. GIVEN CURRENT LACK OF INSTABILITY HAVE LEFT THUNDER MENTION
OUT...THOUGH COULD SEE SOME ISOLATED THUNDER IN THE LATE AFTERNOON
OR EARLY EVENING WITH INCREASING INSTABILITY IN THE FAR WEST.
SHORTWAVE LIFTING NORTH FROM KS/NE WILL BEGIN TO PUSH INTO SOUTHWEST
NEAR 12Z. HAVE CUT BACK ON POPS WITH SLIGHTLY SLOWER PROGRESSION OF
WAVE AND MOISTURE NOTED...NOT PUSHING INTO CWA UNTIL AFTER 12Z.
HOWEVER...PLACEMENT MAY BE TOO FAR SOUTH ACROSS THE WEST. HAVE KEPT
OVERNIGHT LOW TEMPERATURES DOWN A DEGREE OR TWO GIVEN HOW
PRECIPITATION LIMITED DAYTIME HIGHS...AND EXPECT CLEARING SKIES
ACROSS THE NORTH TONIGHT.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 321 PM CDT FRI MAY 1 2015
CONTINUED WAA AND POCKETS OF STRONGER THETA-E WILL DOMINATE
THROUGH THE NEXT WEEK. A WEAK FEATURE WILL MOVE THROUGH THE AREA
ON SATURDAY BRINGING WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS...BUT NOTHING TO REALLY FOCUS ON WITH THIS.
SUNDAY LOOKS TO BE MORE ACTIVE AS DEW POINTS COME UP AND A
STRONGER FRONT MOVES IN. CAPE RISES TO AROUND 2000 J/KG OR SO BY
MID DAY SUNDAY WITH LITTLE RESIDUAL CAP. OTHER PARAMETERS ARE NOT
AS FAVORABLE WITH INFLOW RELATIVELY WEAK AND OVERALL CONVERGENCE
ALONG THE FRONT NOT OPTIMAL. STILL, THUNDER CHANCES ARE DECENT AND
IT APPEARS THAT MARGINAL TO SLIGHT THREAD FOR SEVERE LOOKS
REASONABLE.
THE REST OF THE WEEK WILL BE WARMER THAN NORMAL AND WET. TROUGH IN
THE WEST WILL SEND OUT PERIODIC PIECES WITH THE NEXT STRONGER
PIECE ARRIVING ABOUT THURSDAY...THE NEXT BEYOND THE FORECAST
PERIOD. THOUGH THE SEVERE THREAT LOOKS RELATIVELY LOW...THE
CHANCES FOR WIDESPREAD RAINFALL IN EXCESS OF 2 INCHES IN A WEEK IS
PRETTY GOOD. DO NOT EXPECT THE RAINFALL TO BE A PROBLEM...BUT IT
WILL PUT A CRIMP IN PLANTING PROGRESS.
&&
.AVIATION...01/18Z
ISSUED AT 1220 PM CDT FRI MAY 1 2015
BOUNDARY WILL BRING CHANCE FOR -RA OR -DZ TO SITES BEFORE
00Z...THOUGH WILL BE MOSTLY SCATTERED AND CONDITIONS WILL REMAIN
VFR. WINDS WILL BECOME MORE SOUTHERLY AND DECREASE AFTER 00Z. LATE
IN PERIOD...BEYOND 12Z WINDS WILL SHIFT TO THE SOUTHWEST AND WILL
INCREASE. IN ADDITION...SHRA WILL BE POSSIBLE AND KDSM AND KFOD
VERY LATE IN PERIOD OR BEYOND PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MS MAY 15
SHORT TERM...AWB
LONG TERM...MS MAY 15
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS TOPEKA KS
333 PM CDT Fri May 1 2015
.SHORT TERM...(This Evening through Saturday)
Issued at 333 PM CDT FRI MAY 1 2015
19Z water vapor shows a ridge of high pressure centered over the
AZ/NM boarder and broad cyclonic flow from the Gulf of AK through
western Canada. Within this pattern, much of the shortwave activity
remains along the Canadian boarder. At the surface, a ridge of high
pressure was centered over the MS river valley with a weak trough of
low pressure from northwest KS through the eastern Dakotas.
For tonight and Saturday, there are two potential sources for
forcing convection, and confidence in either one is rather so-so.
The first is a possible convectively induced vort max (MCV) coming
off the central Rockies this evening. The HRRR and RAP have been the
most aggressive in holding precip together off the higher terrain
and into the forecast area through Saturday morning. These solutions
have also be to aggressive in this afternoon`s precip so I don`t
know how much weight to put behind this idea with the GFS and NAM
shearing out any MCV. At this point, have taken a wait and see
approach for the convection to fully move off the mountains.
Additionally the MCV may tend to move just southwest of the forecast
area. The second forcing mechanism may end up being the low level
jet and isentropic lift. The NAM and GFS seem to favor this,
developing precip along the NEB state line and moving it into
northern MO Saturday morning. However it appears the low level jet
will be veered to the southwest with the stronger wind speeds to the
west of the area. Additionally theta-e advection is marginal with
the low level jet. The models do prog some isentropic lift over far
northeast KS which may explain why they are generating precip.
Nevertheless confidence is marginal since the low level jet itself
is not very strong and moisture advection with the jet is weak. Have
kept some 20 to 30 percent POPs across the northern counties through
the morning to account for the possibility.
Lows tonight should be a little more mild with readings remaining in
the lower and mid 50s. Think skies are likely to remain at least
partly cloudy with debris clouds spreading in from the west, helping
to keep lows in the 50s. Models show some warm air advection through
the day Saturday as low level flow remains southerly. Based on 850
temp progs and some insolation through the afternoon, think highs
should warm into the upper 70s and lower 80s.
.LONG TERM...(Saturday Night through Friday)
Issued at 333 PM CDT FRI MAY 1 2015
Increasing low level southerly flow Saturday night into Sunday
brings precipitable water values further above normal to near 1.5
inches. Main forcing mechanism approaches Sunday afternoon as a
northern branch wave allows a cold front to settle south into the
area, likely from southwest Kansas into east central Nebraska. Could
see far western locations impacted late in the afternoon as storms
could fire not far to the west-southwest, but chances increase in
the next few periods as the front ceases its southerly push, between
the northern and southern branches. Just how far the front gets is
obviously a challenge and will be key for precip potential. Have
tapered southern end of precip chances for Sunday night, with best
mean chances Monday into Monday night until southerly flow returns
to the northwest, ushering the front back north. At this point Tuesday
appears the most likely dry period, with a modest but increasingly
powerful upper wave rotating northeast into the Plains Tuesday night
into Wednesday night. Expect most locations to see at least some
precip in this period with deep south flow keeping available
moisture plentiful. Beyond this, model differences increase for a
much less confidence forecast, though a modified front could be in
play with a still warm and moist airmass to support chance PoPs. As
for thunderstorm severity, mid/upper flow is not very strong being
between the northern and southern branches. With greater confidence
in the late weekend/early next week boundary in the vicinity, there
will of course be low level shear potential here with ML CAPE likely
around 1500 J/kg. In the latter wetter period, the wave`s
orientation keeps winds somewhat unidirectional with height, and
instability specifics anything but certain with periodic precip
quite likely. Expect highs to be generally near to a few degrees
above normal, with main problem being depth/persistence of
cloud/precip north of the front Monday to bring possibly cooler
temps possible in northern areas.
&&
.AVIATION...(For the 18Z TAFs through 18Z Saturday Afternoon)
Issued at 1224 PM CDT FRI MAY 1 2015
Very limited forcing should keep any shower activity isolated
through the period. Therefore will maintain a VFR forecast
expecting only some mid level clouds lingering in the weak mid
level flow.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
220 PM MDT FRI MAY 1 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 150 PM MDT FRI MAY 1 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS BROAD RIDGE IN
PALACE ACROSS THE SOUTHERN PLAINS WITH WESTERLY FLOW EXTENDING FROM
THE GREAT BASIN ACROSS THE CENTRAL ROCKIES AND INTO THE CENTRAL
PLAINS. A WEAK SHORTWAVE H5/H7 TROUGH IS IN THE PROCESS OF ROTATING
THROUGH THE MEAN FLOW ACROSS THE CENTRAL ROCKIES WITH
SHOWER/THUNDERSTORM DEVELOPMENT APPARENT ON UPSTREAM RADARS MOVING
EAST OFF THE HIGHER TERRAIN. AT THE SURFACE LOW PRESSURE IS IN PLACE
ACROSS THE CWA WITH A STATIONARY FRONT ALONG THE SOUTHEASTERN CORNER
OF THE CWA EXTENDING SOUTH IN SOUTHEAST COLORADO.
THIS AFTERNOON-TONIGHT...FOCUS CONTINUES TO BE ON POTENTIAL FOR
THUNDERSTORMS DEVELOPING OVER THE CWA OR SPREADING EAST INTO THE
CWA AS SHORTWAVE MOVES THROUGH THE REGION. WITH FRONT IN PLACE AND
AIR MASS DESTABILIZING THERE IS SOME CONCERN THAT ISOLATED
THUNDERSTORMS COULD DEVELOP AHEAD OF MAIN SHORTWAVE. HIGH CINH
VALUES CURRENTLY IN PLACE ARE INHIBITING CONVECTION CURRENTLY OVER
THE CWA DESPITE INCREASING INSTABILITY. AS SHORTWAVE MOVES EAST
IT APPEARS THE CAP SHOULD WEAKEN ALLOWING FOR INCREASING CHANCES
FROM THE WEST TO THE EAST. BEST PRECIP SIGNAL FROM RAP/HRRR
CONTINUES TO BE IN THE SOUTHWEST PART OF THE CWA. 12Z GUIDANCE WAS
RUNNING HIGH REGARDING CAPE VALUES MOST OF THE DAY...THOUGH AS
SKIES HAVE CLEARED THE LATEST RAP ANALYSIS DOES SHOW 500-1000 KG/J
ML CAPE DEVELOPING OVER THE REGION. SHEER IS NOT PARTICULARLY
IMPRESSIVE AND AT THIS POINT SEVERE THREAT SEEMS TO BE LIMITED.
ANY SHOWER/THUNDERSTORM ACTIVITY SHOULD QUICKLY DISSIPATE OR
TRANSITION EAST OF THE CWA THROUGH LATE THIS EVENING AS A SHARP
AREA OF SUBSIDENCE MOVES IN BEHIND EXITING SHORTWAVE.
SATURDAY...VERY GOOD WAA IS ADVERTISED AND WITH CLEARING SKIES
DURING THE FIRST PART OF THE DAY HIGHS SHOULD REACH THE 80S ACROSS
THE CWA...POSSIBLY IN THE MID/UPPER 80S IN THE EAST. THE NEXT
SHORTWAVE IS SHOWN TO APPROACH THE REGION FROM THE CENTRAL ROCKIES
LATE AFTERNOON WITH THUNDERSTORM INITIATION NEAR SURFACE TROUGH
ALONG CO/KS BORDER POSSIBLE AFTER 21Z...OTHERWISE BETTER CHANCES
ARRIVE LATER IN THE EVENING. MODELS ARE SHOWING VERY UNSTABLE AIR
BUILDING OVER THE REGION WITH NAM ADVERTISING 1500-2500 J/KG OF ML
CAPE BY LATE AFTERNOON. SHEER IS A LITTLE BETTER THAN TODAY WITH
EFFECTIVE SHEER IN EXCESS OF 35KT. WITH THIS IN MIND ANY
THUNDERSTORMS THAT DEVELOP LATE TUESDAY AFTERNOON COULD
POTENTIALLY ORGANIZE AND BECOME SEVERE. WITH MINIMAL LOW LEVEL
SHEER LARGE HAIL/DAMAGING WIND CONTINUE TO BE MAIN CONCERNS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 218 PM MDT FRI MAY 1 2015
A FLATTENED RIDGE WILL BE OVER THE SOUTHERN PLAINS THROUGH SUNDAY
NIGHT WITH WESTERLY FLOW OVER THE CENTRAL PLAINS. THE SOUTHERN
PLAINS RIDGE WILL SHIFT EASTWARD MONDAY WITH SOUTHWEST FLOW OVER THE
CENTRAL PLAINS. A SURFACE TROUGH OVER EASTERN COLORADO WILL MIGRATE
SLOWLY EAST ACROSS NORTHWEST KANSAS THROUGH SUNDAY NIGHT. SURFACE
HIGH PRESSURE WILL MOVE INTO THE REGION MONDAY BEHIND THE EXITING
TROUGH.
A SHORTWAVE MOVES ACROSS THE FA SATURDAY EVENING WITH SUBSIDENCE
INDICATED AFTER 06Z TUESDAY AS THE SHORTWAVE SLIDES SOUTHEAST OUT OF
THE AREA. H8-7 LAYER MEAN RH IS NOT IDEAL SO WILL KEEP POPS AT
SLIGHT CHANCE. CAPE VALUES UP TO 1000 J/KG ARE EXPECTED WITH AN
AREA OF 35 KTS SHEAR OVER NORTHEAST COLORADO. A FEW ISOLATED
MARGINALLY SEVERE STORMS ARE POSSIBLE. SUBSIDENCE CONTINUES THROUGH
SUNDAY MORNING AND INTO THE AFTERNOON. THE NEXT SHORTWAVE SHOULD
IMPACT EASTERN COLORADO BY MID TO LATE AFTERNOON. PLAN TO GO WITH
CHANCE POPS OVER WESTERN PORTIONS OF EASTERN COLORADO AND ALSO NEAR
THE TROUGH AXIS IN THE SOUTHEASTERN FA. GOOD DYNAMICS AND MOISTURE
MOVE ACROSS THE FA SUNDAY NIGHT SO WILL GO WITH HIGHER CHANCE POPS
ESPECIALLY IN THE WEST DURING THE EVENING WHERE STORMS SHOULD
ALREADY BE IN PROGRESS. HIGH CHANCE POPS WILL CONTINUE AFTER 06Z
MONDAY AS THE SHORTWAVE IMPACTS THE ENTIRE AREA. MONDAY DOES NOT
APPEAR TO BE AS FAVORABLE FOR PRECIPITATION AS HIGH PRESSURE
BUILDING IN FROM THE NORTH PUSHES THE SURFACE BOUNDARY FURTHER
SOUTH. FURTHERMORE, THE MAIN SURFACE LOW IS OVER SOUTHERN
CALIFORNIA, DYNAMICS ARE MORE UNCERTAIN. CONSEQUENTLY LOWERED POPS
SOME BUT STILL KEPT CHANCE POPS OVER THE AREA MONDAY AFTERNOON.
MIN TEMPERATURES SHOULD VARY FROM THE UPPER 40S TO THE LOWER 50S
SATURDAY AND SUNDAY NIGHTS. MAX TEMPERATURES SHOULD RISE TO THE LOWER
TO MID 80S SUNDAY AND THEN COOL TO THE MID 60S TO AROUND 70 MONDAY.
IN THE EXTENDED...(TUESDAY THROUGH FRIDAY)...ACTIVE WEATHER IS
EXPECTED FOR THIS PART OF THE FORECAST. AN UPPER LEVEL TROUGH OVER
THE SW CONUS WILL MOVE NORTHEAST AND PHASE INTO A TROUGH OVER THE
PACIFIC NORTHWEST. NUMEROUS SHORTWAVES WILL MOVE THROUGH THE FLOW
AND ACROSS THE CENTRAL PLAINS. THERE WILL BE A CHANCE OF SHOWERS
AND THUNDERSTORMS ACROSS THE FA ON A DAILY BASIS THROUGH FRIDAY.
MIN TEMPERATURES WILL COOL TO THE UPPER 40S AND LOWER 50S. MAX
TEMPERATURES SHOULD RANGE FROM 65 TO 70 TUESDAY WARMING TO THE 70S
WEDNESDAY THROUGH FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1125 AM MDT FRI MAY 1 2015
VFR CONDITIONS CURRENTLY EXPECTED TO PREVAIL AT BOTH KGLD AND
KMCK. THERE IS SOME INDICATION OF INCREASING BOUNDARY LAYER
MOISTURE AND THE POSSIBILITY FOR STRATUS DEVELOPMENT
LATE...HOWEVER THIS WILL BE HEAVILY DEPENDENT ON POSITION OF
SURFACE FRONT AND COVERAGE OF SHOWERS/THUNDERSTORMS. AT THIS TIME
THERE WAS TOO MUCH UNCERTAINTY TO INCLUDE LOWER CONDITIONS IN THE
TAF. I INCLUDED A VCSH AT KGLD AS BETTER PRECIP SIGNAL INDICATES
SCATTERED COVERAGE FROM THE WEST AND LESS COVERAGE IN THE
NORTHEAST NEAR KMCK. MODELS APPEAR TO BE OVERDONE REGARDING
INSTABILITY AND COVERAGE OF THUNDERSTORMS IS UNCERTAIN WITH
SHOWERS POSSIBLY FAVORED THIS AFTERNOON/EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
151 PM MDT FRI MAY 1 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 150 PM MDT FRI MAY 1 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS BROAD RIDGE IN
PALACE ACROSS THE SOUTHERN PLAINS WITH WESTERLY FLOW EXTENDING FROM
THE GREAT BASIN ACROSS THE CENTRAL ROCKIES AND INTO THE CENTRAL
PLAINS. A WEAK SHORTWAVE H5/H7 TROUGH IS IN THE PROCESS OF ROTATING
THROUGH THE MEAN FLOW ACROSS THE CENTRAL ROCKIES WITH
SHOWER/THUNDERSTORM DEVELOPMENT APPARENT ON UPSTREAM RADARS MOVING
EAST OFF THE HIGHER TERRAIN. AT THE SURFACE LOW PRESSURE IS IN PLACE
ACROSS THE CWA WITH A STATIONARY FRONT ALONG THE SOUTHEASTERN CORNER
OF THE CWA EXTENDING SOUTH IN SOUTHEAST COLORADO.
THIS AFTERNOON-TONIGHT...FOCUS CONTINUES TO BE ON POTENTIAL FOR
THUNDERSTORMS DEVELOPING OVER THE CWA OR SPREADING EAST INTO THE
CWA AS SHORTWAVE MOVES THROUGH THE REGION. WITH FRONT IN PLACE AND
AIR MASS DESTABILIZING THERE IS SOME CONCERN THAT ISOLATED
THUNDERSTORMS COULD DEVELOP AHEAD OF MAIN SHORTWAVE. HIGH CINH
VALUES CURRENTLY IN PLACE ARE INHIBITING CONVECTION CURRENTLY OVER
THE CWA DESPITE INCREASING INSTABILITY. AS SHORTWAVE MOVES EAST
IT APPEARS THE CAP SHOULD WEAKEN ALLOWING FOR INCREASING CHANCES
FROM THE WEST TO THE EAST. BEST PRECIP SIGNAL FROM RAP/HRRR
CONTINUES TO BE IN THE SOUTHWEST PART OF THE CWA. 12Z GUIDANCE WAS
RUNNING HIGH REGARDING CAPE VALUES MOST OF THE DAY...THOUGH AS
SKIES HAVE CLEARED THE LATEST RAP ANALYSIS DOES SHOW 500-1000 KG/J
ML CAPE DEVELOPING OVER THE REGION. SHEER IS NOT PARTICULARLY
IMPRESSIVE AND AT THIS POINT SEVERE THREAT SEEMS TO BE LIMITED.
ANY SHOWER/THUNDERSTORM ACTIVITY SHOULD QUICKLY DISSIPATE OR
TRANSITION EAST OF THE CWA THROUGH LATE THIS EVENING AS A SHARP
AREA OF SUBSIDENCE MOVES IN BEHIND EXITING SHORTWAVE.
TUESDAY...VERY GOOD WAA IS ADVERTISED AND WITH CLEARING SKIES DURING
THE FIRST PART OF THE DAY HIGHS SHOULD REACH THE 80S ACROSS THE
CWA...POSSIBLY IN THE MID/UPPER 80S IN THE EAST. THE NEXT
SHORTWAVE IS SHOWN TO APPROACH THE REGION FROM THE CENTRAL ROCKIES
LATE AFTERNOON WITH THUNDERSTORM INITIATION NEAR SURFACE TROUGH
ALONG CO/KS BORDER POSSIBLE AFTER 21Z...OTHERWISE BETTER CHANCES
ARRIVE LATER IN THE EVENING. MODELS ARE SHOWING VERY UNSTABLE AIR
BUILDING OVER THE REGION WITH NAM ADVERTISING 1500-2500 J/KG OF ML
CAPE BY LATE AFTERNOON. SHEER IS A LITTLE BETTER THAN TODAY WITH
EFFECTIVE SHEER IN EXCESS OF 35KT. WITH THIS IN MIND ANY
THUNDERSTORMS THAT DEVELOP LATE TUESDAY AFTERNOON COULD
POTENTIALLY ORGANIZE AND BECOME SEVERE. WITH MINIMAL LOW LEVEL
SHEER LARGE HAIL/DAMAGING WIND CONTINUE TO BE MAIN CONCERNS.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 348 AM MDT FRI MAY 1 2015
AN UPPER LEVEL LOW SITUATED OVER THE PACIFIC NORTHWEST WILL SLOWLY
MOVE SOUTHEAST INTO THE INTERMOUNTAIN WEST MONDAY THROUGH WEDNESDAY.
SEVERAL SHORTWAVES WILL FORM ALONG THE SOUTHERN AXIS OF THIS LOW AND
MOVE ACROSS THE REGION NEXT WEEK. A POTENT AREA OF LOW PRESSURE WILL
FORM ON MONDAY IN THE SOUTHWEST US AND MOVE NORTHWARD INTO SOUTHERN
COLORADO ON TUESDAY. LOOKING AT THE 500MB AND 700MB HEIGHT FIELDS...
A NEGATIVE TROUGH WILL TAKE SHAPE AS WE HEAD INTO LATE MONDAY NIGHT
AND TUESDAY MORNING AND AMPLIFY OVER THE COURSE OF THE DAY. CAPE AND
OMEGA VALUES TUESDAY MORNING WILL BE HIGHEST IN THE SOUTHERN
PORTIONS OF THE CWA AND WILL SPREAD NORTHWARD THROUGH THE DAY
HOWEVER CAPE VALUES ARE RELATIVELY MODEST AT THIS POINT. SHEAR IS
EXPECTED TO INCREASE AS THE DAY PROGRESSES AS WELL. THERE IS A
POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS ON BOTH MONDAY AND
TUESDAY AS THIS SYSTEM SLOWLY LIFTS NORTHWARD. THERE WILL BE ENOUGH
MOISTURE AND INSTABILITY ON WEDNESDAY TO ALLOW THE CHANCE FOR AT
LEAST ISOLATED TO SCATTERED THUNDERSTORMS AS THE DISTURBANCE
CONTINUES TO INFLUENCE THE REGION... CONTINUING NORTHWARD THROUGH
THE DAY. GIVEN THE PRESENCE OF RELATIVELY HIGH SHEAR... MARGINAL
CAPE AND DCAPE... AND HIGH PW VALUES WE COULD SEE LOCALLY HEAVY
RAIN... SEVERE HAIL AND GUSTY WINDS. THERE IS STILL SOME UNCERTAINTY
IN THE FORECAST HOWEVER BRIEF TORNADOES CANNOT BE RULED OUT
ESPECIALLY DURING THE AFTERNOON AND EARLY EVENING HOURS MAINLY ON
MONDAY AND TUESDAY AS SHEAR BEGINS TO TAPER OFF ON WEDNESDAY.
EARLY INDICATIONS SHOW THE POSSIBILITY OF SLIGHT RAIN CHANCES AS WE
HEAD INTO THURSDAY AS THE MAIN AREA OF LOW PRESSURE LOCATED OVER THE
PACIFIC NORTHWEST CONTINUES TO PUSH SHORTWAVES ACROSS THE REGION
FROM SOUTHWEST TO NORTHEAST. AT THIS POINT POP REMAINS IN THE 20-30
PERCENT RANGE HOWEVER THERE IS MUCH DISAGREEMENT BETWEEN THE GLOBAL
MODELS AT THIS TIME WITH THE GFS CONTINUING THE TREND OF BEING MORE
AGGRESSIVE WITH BOTH MOISTURE AVAILABILITY AND TROUGH STRENGTH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1125 AM MDT FRI MAY 1 2015
VFR CONDITIONS CURRENTLY EXPECTED TO PREVAIL AT BOTH KGLD AND
KMCK. THERE IS SOME INDICATION OF INCREASING BOUNDARY LAYER
MOISTURE AND THE POSSIBILITY FOR STRATUS DEVELOPMENT
LATE...HOWEVER THIS WILL BE HEAVILY DEPENDENT ON POSITION OF
SURFACE FRONT AND COVERAGE OF SHOWERS/THUNDERSTORMS. AT THIS TIME
THERE WAS TOO MUCH UNCERTAINTY TO INCLUDE LOWER CONDITIONS IN THE
TAF. I INCLUDED A VCSH AT KGLD AS BETTER PRECIP SIGNAL INDICATES
SCATTERED COVERAGE FROM THE WEST AND LESS COVERAGE IN THE
NORTHEAST NEAR KMCK. MODELS APPEAR TO BE OVERDONE REGARDING
INSTABILITY AND COVERAGE OF THUNDERSTORMS IS UNCERTAIN WITH
SHOWERS POSSIBLY FAVORED THIS AFTERNOON/EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...TML
AVIATION...DR
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1224 PM CDT Fri May 1 2015
.UPDATE...
Issued at 1224 PM CDT FRI MAY 1 2015
The light shower activity seems to be having a hard time holding
together against the dry air seen in this morning`s 12Z RAOB. With
the water vapor imagery showing the upper shortwave trough well
north of the area, may remove POPs from this afternoon and this
evening all together. Will also trend afternoon highs a little
warmer, though based on RAP and GFS forecast soundings think temps
will remain below 80 degrees this afternoon.
Tonight`s precip chances appear to be dependent on whether a
convectively induced vort max moves out from the central Rockies
this evening. Only the high resolution models seem to think this
is possible. Still have some things to look at, but I do not
foresee precip chances to be very high.
&&
.SHORT TERM...(Today and Tonight)
Issued at 332 AM CDT FRI MAY 1 2015
Water vapor loop shows nearly zonal stronger flow aloft across the
northern Rockies and northern Plains states with a well-defined
shortwave trough from the eastern Dakotas into northwest MN. A band
of showers is associated with lift ahead of upper trough moving
through western MN trailing back into northeast Nebraska at this
time. Forcing associated with this system should stay well to north
of forecast area today. However, regional radar loops show showers
and isolated thunderstorms occurring with trailing cold front/trough
from central Nebraska into northwest KS. There is some disagreement
among models but NAM, RAP and HRRR show remnants of this high-based
precip making it into north central KS by early afternoon and then
moving across far northeastern KS during the rest of the afternoon.
While confidence is not high in measurable precip with this
activity, have continued slight chance POPs for far northern
counties this afternoon. Something similar could happen again
tonight with developing showers and thunderstorms over western
Nebraska, which is forecast by some models to persist and move into
far northern parts of our area tonight. Once again, without a
stronger upper level system or recognizable front coming through,
this will be a low chance event, with slightly better chances to our
north.
Considerable mid and high level cloudiness today could make high
temp forecast tricky. Still think enough sunshine will get through
to allow highs to reach the mid to upper 70s.
.LONG TERM...(Saturday through Thursday)
Issued at 332 AM CDT FRI MAY 1 2015
By Saturday, fairly zonal mid-level flow will be in place with
surface high pressure prevailing across the southeastern U.S. and
surface low pressure extending along the High Plains. Models
continue to show a few weak embedded shortwaves developing within
the zonal flow on Saturday as a vort max skims just north of the
CWA. However, with no surface feature to help further support these
waves and with model soundings showing a decent amount of dry air in
the low levels, have only slight chance PoPs in across far northern
and far northeast Kansas Saturday morning with dry conditions by the
afternoon as the associated vort max lifts to the northeast. With
the above-mentioned surface pattern in place, southerly surface
winds should boost high temperatures into the upper 70s/low 80s.
Have gone with a dry forecast Saturday afternoon through Sunday
before the next system moves into the region, which will be the
beginning of a wet stretch of weather that looks to extend through
the latter part of next week. Models show the surface low advancing
eastward toward the CWA on Sunday, resulting in an increased
pressure gradient, breezy southerly winds, and thus good warm air
advection that should support the warmest temperatures of the week
with highs reaching into the low/mid 80s. Precipitation chances will
increase Sunday night through Monday as a cold front slowly sags
southeastward across the CWA. However, models show the front
stalling out over the southern portions of the forecast area and
pivoting over the area before lifting northward as a warm front to
just north of the KS/NE border on Tuesday. As a result, have chance
to likely PoPs for thunderstorms from Sunday night through Monday
night. Even though the cap looks to significantly weaken through the
day on Monday and the amount of available instability is modest,
wind shear looks to be fairly weak across the region, thus limiting
the potential for strong storms. With the warm front lifting into
Nebraska, ECMWF/GEM actually keep Tuesday predominantly dry while
the GFS tries to hold on to some scattered precipitation chances, so
have lowered PoPs. However, thunderstorm chances increase once again
by Tuesday night as a mid-level trough becomes negatively tilted and
begins to lift northward into the central U.S. This approaching
trough will not only provide additional forcing to support
thunderstorm development, but also push another area of surface low
pressure into the area by mid week. However, there are still model
discrepancies in the evolution of the mid-level trough as it lifts
northward and in the timing of the passage of the cold front, which
should track eastward across the area sometime during the latter
part of the week. As a result, there is uncertainty still with when
this system will exit the region. At this time, have chance to
likely PoPs in from Tuesday night through Thursday night. The best
potential for some more-organized storms looks to be during the mid
to late week period in which the combination of the surface low
pressure system and mid-level trough should provide decent forcing
along with decent instability and some slightly improved wind shear.
At this time, temperatures next week look to be fairly steady with
highs in the 70s and lows in the 50s to low 60s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Saturday Afternoon)
Issued at 1224 PM CDT FRI MAY 1 2015
Very limited forcing should keep any shower activity isolated
through the period. Therefore will maintain a VFR forecast
expecting only some mid level clouds lingering in the weak mid
level flow.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...GDP
LONG TERM...Hennecke
AVIATION...Wolters
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1244 PM CDT Fri May 1 2015
.UPDATE:
Issued at 1152 AM CDT Fri May 1 2015
Based on cloud trends from this morning`s satellite imagery,
afternoon update will increase the clouds a bit faster over our
far NW counties. Otherwise, forecast is looking good and generally
remains unchanged.
Truett
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 322 AM CDT Fri May 1 2015
Dry and tranquil weather is expected today as weak height rises
commence aloft with the departure of the mid Atlantic upper
low/trof and eastward shift in the upper ridge currently centered
in the southern Rockies. The surface high centered in northern IL
will only meander southeast. This will translate to a nice day with
light winds, lots of morning sun, and some thin high clouds in the
afternoon. Temperatures will be seasonable and forecast highs are
a blend of the warmer MAV MOS and RAP 2m temps.
Glass
.LONG TERM: (Tonight through Thursday)
Issued at 322 AM CDT Fri May 1 2015
The tail end of a weak short wave passing to the north will bring
an increase in cloudiness overnight. The persistent and ever so
slowly retreating low level anticyclone will limit low level
moisture transport/return to the Plains into Iowa. That said the
increase in mid level moisture and warm advection may be
sufficient for spotty showers across parts of northeast MO. While
southerly flow and WAA becomes better established Saturday and
Saturday night in the wake of the slow retreating anticyclone,
trajectories are poor for low level moisture return. Once again
the main impetus for pops will be mid level moisture, WAA,
glancing influence from passing disturbances, and some marginal
elevated instability leading to slight chance pops across parts of
northeast MO and west central IL. The ridge aloft builds east into
the OH Valley on Sunday and the threat of precipitation takes a
decided northward shift to the vicinity of a cold front moving
through the northern Plains and upper MS Valley. The threat of
showers and thunderstorms will progressively increase late Sunday
night into Monday night as the cold front approaches Sunday night
and then becomes quasi-stationary across northern MO and west
central IL Monday into Monday night. By this time the low level
moisture and hence instability is much improved owing to
persistent s-sw lower trop flow and presence of steep mid level
lapse rates. This front then moves back north by midweek leading
to a diminished precipitation threat, which increases again late
week with the development of southwest flow aloft and accompanying
disturbances and continued low level moisture transport.
Temperatures will be above average beginning this weekend and
continuing all of next week.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1242 PM CDT Fri May 1 2015
Several weak shortwaves will pass over the region during the next
24 hours. However, low level moisture will be non-existent thanks
to surface ridge maintaining its firm grip over the mid-
Mississippi Valley, so impacts of the shortwave energy will be
limited to occasional bands of mid level cloudiness (with bases
aoa 8kft). Any threat of rain will remain very low. Surface winds
will also remain quite light.
Specifics for KSTL: VFR conditions will continue into the start of
the weekend, with the clear skies of this afternoon giving way to
a bit of mid level cloudiness (bases aoa 8kft) tonight and into
Saturday. Winds will remain quite light...generally aob
6 kts...into Saturday morning.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1154 AM CDT Fri May 1 2015
.UPDATE:
Issued at 1152 AM CDT Fri May 1 2015
Based on cloud trends from this morning`s satellite imagery,
afternoon update will increase the clouds a bit faster over our
far NW counties. Otherwise, forecast is looking good and generally
remains unchanged.
Truett
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 322 AM CDT Fri May 1 2015
Dry and tranquil weather is expected today as weak height rises
commence aloft with the departure of the mid Atlantic upper
low/trof and eastward shift in the upper ridge currently centered
in the southern Rockies. The surface high centered in northern IL
will only meander southeast. This will translate to a nice day with
light winds, lots of morning sun, and some thin high clouds in the
afternoon. Temperatures will be seasonable and forecast highs are
a blend of the warmer MAV MOS and RAP 2m temps.
Glass
.LONG TERM: (Tonight through Thursday)
Issued at 322 AM CDT Fri May 1 2015
The tail end of a weak short wave passing to the north will bring
an increase in cloudiness overnight. The persistent and ever so
slowly retreating low level anticyclone will limit low level
moisture transport/return to the Plains into Iowa. That said the
increase in mid level moisture and warm advection may be
sufficient for spotty showers across parts of northeast MO. While
southerly flow and WAA becomes better established Saturday and
Saturday night in the wake of the slow retreating anticyclone,
trajectories are poor for low level moisture return. Once again
the main impetus for pops will be mid level moisture, WAA,
glancing influence from passing disturbances, and some marginal
elevated instability leading to slight chance pops across parts of
northeast MO and west central IL. The ridge aloft builds east into
the OH Valley on Sunday and the threat of precipitation takes a
decided northward shift to the vicinity of a cold front moving
through the northern Plains and upper MS Valley. The threat of
showers and thunderstorms will progressively increase late Sunday
night into Monday night as the cold front approaches Sunday night
and then becomes quasi-stationary across northern MO and west
central IL Monday into Monday night. By this time the low level
moisture and hence instability is much improved owing to
persistent s-sw lower trop flow and presence of steep mid level
lapse rates. This front then moves back north by midweek leading
to a diminished precipitation threat, which increases again late
week with the development of southwest flow aloft and accompanying
disturbances and continued low level moisture transport.
Temperatures will be above average beginning this weekend and
continuing all of next week.
Glass
&&
.AVIATION: (For the 12z TAFs through 12z Saturday Morning)
Issued at 550 AM CDT Fri May 1 2015
VFR conditions with light and vrb winds anticipated thru the
period. RA can not be ruled out at UIN late tonight. Otherwise, no
precip anticipated at terminals.
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
243 PM CDT FRI MAY 1 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 242 PM CDT FRI MAY 1 2015
WEAK HIGH PRESSURE OVERHEAD WILL PIVOT MOISTURE NORTHWARD THIS
EVENING. THE RAP AND HRRR SUGGEST WEAKLY ORGANIZED DISCRETE SHOWER
AND THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON AND THIS EVENING.
OTHER THAN GUSTY OUTFLOW WINDS...NO SIGNIFICANT WEATHER IS EXPECTED
AND NO STORMS SHOULD REACH SEVERE LIMITS.
A WARM FRONT WILL LIFT NORTH AS THE HIGH MOVES EAST LATER THIS
EVENING. DEW POINTS SHOULD INCREASE TO AROUND 50F BY MID SATURDAY
MORNING. THE NAM CONTINUES TO ADVERTISE A FAIRLY ROBUST DRYLINE
SURGE SATURDAY AFTN FOCUSED ALONG HIGHWAY 20 WEST OF VALENTINE.
DESTABILIZATION IS POSSIBLE ACROSS PINE RIDGE AND THE WRN SANDHILLS
SOUTH THROUGH IMPERIAL AROUND 21Z. THE NAM DID SHOW ABOUT 20 TO 30
J/KG OF INHIBITION SO POPS ARE ISOLATED. MLCAPE NEAR 1500 J/KG AND
BULK SHEAR TO 450 MB OF 30 TO 35 KT COULD SUPPORT AN ISOLATED STRONG
OR SEVERE STORM DURING THE PEAK HEATING PERIOD. THE BULK RICHARDSON
NUMBER IS CLOSE TO 50 AT THIS TIME AND SHEAR PROFILES LOOK SMOOTHLY
CURVED.
LOWS TONIGHT FALL TO THE UPPER 40S TO AROUND 50. HIGHS SATURDAY RISE
INTO THE LOW TO MID 80S WITH MIXING HEIGHTS NEAR 700 MB.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 242 PM CDT FRI MAY 1 2015
A TRAJECTORY FROM THE PACIFIC SOUTHWEST CONTINUES SATURDAY NIGHT
WHILE A TRAJECTORY FROM THE TEXAS GULF COAST CROSSES CENTRAL AND
EASTERN NEBRASKA. THE PACIFIC MOISTURE WILL THUS BE IN PLACE WHEN A
SURFACE FRONT COMES THROUGH SUNDAY MORNING. THE TIMING OF THE FRONT
IS NOT REAL FAVORABLE FOR THUNDERSTORMS. HOWEVER...THE LIFT SHOULD
BE SUFFICIENT TO TRIGGER ISOLATED CONVECTION BY SUNDAY EVENING WITH
IT CONTINUING SUNDAY NIGHT AND MONDAY IN CENTRAL AND SOUTHWEST
NEBRASKA.
WITH THE FRONT BECOMING STATIONARY ACROSS CENTRAL KANSAS...SOME
UPGLIDE WILL CONTINUE INTO MONDAY AFTERNOON AND EVENING. THIS CAN BE
SEEN WITH THE PRESSURE LEVELS AND MOISTURE TRANSPORT VECTORS OVER
CENTRAL...SOUTH CENTRAL AND SOUTHWEST NEBRASKA ON THE 300K AND 305K
SURFACES. THE INSTABILITY...AT ABOUT 0C FOR THE 800MB BASED LIFTED
INDEX...IS EXPECTED TO BE MARGINAL. AS A RESULT...ONLY A FEW
EMBEDDED THUNDERSTORMS ARE EXPECTED IN AN AREA OF GENERAL RAIN OR
SHOWERS. WITH PRECIPITABLE WATER EXCEEDING 0.7 INCH...SIGNIFICANT
PRECIPITATION TOTALS CAN BE EXPECTED ALONG A BROKEN BOW-NORTH
PLATTE-IMPERIAL LINE AND SOUTH WITH AMOUNTS DROPPING OFF SHARPLY
NORTH OF THAT LINE.
AS THE ACTIVE UPPER PATTERN CONTINUES...ANOTHER NEGATIVELY TILTED
TROUGH PIVOTS ACROSS THE NORTHERN PLAINS. AHEAD OF THE SYSTEM...A
GOOD MOISTURE TRAJECTORY CONTINUES TUESDAY NIGHT AND WEDNESDAY FROM
THE TEXAS GULF COAST INTO NEBRASKA AND THE DAKOTAS. AS THE CYCLONE
MAKES ITS WAY NORTHWARD...WARM ADVECTION ALOFT WILL CONTINUE
BRINGING WIDESPREAD RAINFALL TO WESTERN NEBRASKA. BY EARLY
THURSDAY...THE DRY INTRUSION OVERTAKES THE CYCLONE AND BRINGS AN END
TO THE PRECIPITATION IN CENTRAL AND WESTERN NEBRASKA. THERE IS
SIGNIFICANT DISAGREEMENT BETWEEN THE 00Z ECMWF AND THE 12Z GFS40
WITH THIS SYSTEM...SO CONFIDENCE IS NOT HIGH IN THE SOLUTIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1224 PM CDT FRI MAY 1 2015
VFR IS EXPECTED ALONG AND NORTH OF HIGHWAY 2 THIS AFTN THROUGH
SATURDAY MORNING. SOUTH OF THIS AREA ISOLATED WEAKLY ORGANIZED
SHOWER AND THUNDERSTORM COVERAGE IS EXPECTED FROM 21Z THIS
AFTERNOON THROUGH 08Z TONIGHT. VFR IS EXPECTED ALL AREAS
THEREAFTER.
STORM DEVELOPMENT IS EXPECTED ALONG THE LARAMIE AND COLORADO
RANGES 18Z-21Z WITH ACTIVITY MOVING EAST INTO THE FORECAST AREA
THIS EVENING. OTHER ISOLATED ACTIVITY COULD DEVELOP ALONG AND
SOUTH OF INTERSTATE 80 THIS AFTERNOON 21Z-00Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...SPRINGER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
110 PM CDT FRI MAY 1 2015
.SHORT TERM...(TODAY)
ISSUED AT 341 AM CDT FRI MAY 1 2015
PCPN CHANCES/PCPN COVERAGE AND TEMPERATURES WILL PROVIDE THE MAIN
FORECAST CHALLENGES FOR THE TODAY PERIOD.
REGIONAL RADAR LOOP EARLY THIS MORNING SHOWED SHOWERS AND A FEW
EMBEDDED THUNDERSTORMS OCCURRING IN ASSOCIATION WITH A WEAK COLD
FRONT MOVING EASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS. THIS
FRONT SHOULD STALL OUT AND THEN WASH OUT THIS EVENING. LATEST SHORT
RANGE HIGH RESOLUTION MODELS ARE IN DECENT AGREEMENT SHOWING SOME
SCATTERED AND MAINLY LIGHT PCPN MOVING ACROSS THE FORECAST AREA THIS
MORNING. 06Z RAP SEEMED TO HAVE A FAIRLY GOOD HANDLE ON THE PATTERN.
LOOK FOR HIGHS MOSTLY IN THE LOWER AND MID 70S BUT A FEW LOCATIONS
IN WEST CENTRAL IOWA MAY ONLY REACH NEAR 70.
MILLER
SHORT TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 341 AM CDT
FRI MAY 1 2015
FOCUS FOR POSSIBLE PCPN SHIFTS TO THE SRN CWA TONIGHT AND SATURDAY
MORNING WHERE 310K UPGLIDE AND LOW COND PRES DEF WILL BE MOST
PREVALENT.
NEXT ROUND OF PCPN ASSOCIATED WITH A COLD FRONT DROPPING THRU THE
DAKOTAS/UPPER MID WEST SATURDAY NIGHT THE INTO THE CWA ON SUNDAY.
MODELS HOLD OFF DEVELOPMENT UNTIL AFTN WHEN ENVIRONMENT BECOMES
ADEQUATELY UNSTABLE...THEN INCREASES IN AREAL COVERAGE AND
INTENSITY SUNDAY NIGHT IN RESPONSE TO STRENGTHENING BNDRY LYR
MOISTURE CONVERGENCE. WITH RELATIVELY HIGH CONCENTRATION OF
ENVIRONMENTAL MOISTURE AND PERSISTENT FORCING...CONDITIONS WILL
BE FAVORABLE FOR SOME LOCATIONS TO SEE RAINFALL AMOUNTS OF HALF
AND INCH OR SO.
DEE
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI MAY 1 2015
SFC BNDRY AT THIS POINT PROGGED TO BECOME NEARLY STATIONARY MONDAY
MORNING THRU TUESDAY MORNING. PERSISTENT INFLUX OF GULF MOISTURE
COUPLED WITH MOIST BNDRY LYR CONVERGENCE/INSTABILITY AXIS SITUATED
OVER THE CWA WOULD SUGGEST CONDITIONS WILL AGAIN BE FAVORABLE FOR
SIGNIFICANT RAINFALL ACCUMULATIONS. TUESDAY AFTN THRU THURSDAY
NIGHT PCPN ACCUMULATIONS BEING DRIVEN BY EXTENDED PERIOD OF 305K
UPGLIDE/PRESIDENT LLVL MOISTURE ADVECTION. OTHERWISE...METEOGRAMS
STILL SHOWING MODERATE COOL NEXT WEEK IN LIGHT OF SFC BNDRY MOVING
IN.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 107 PM CDT FRI MAY 1 2015
MAINLY VFR CONDITIONS ARE FORECAST THROUGH SATURDAY MORNING.
SCATTERED SHOWERS MAY AFFECT ALL TAF SITES THROUGH THE
AFTERNOON...BUT STILL EXPECT VFR CIGS/VSBYS IN ALL BUT THE
HEAVIEST SHOWERS. THERE SHOULD BE PERIOD OF DRY WEATHER DURING THE
EVENING...WITH MORE SHOWERS MOVING TOWARD KLNK AND KOMA AFTER 06Z.
AGAIN MAINLY VFR CIGS/VSBYS ARE FORECAST WITH THIS ACTIVITY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER/DEE
LONG TERM...DEE
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 PM EDT FRI MAY 1 2015
.SYNOPSIS...AN UPPER LEVEL LOW AND ASSOCIATED SURFACE LOW WILL MOVE
EAST OF THE AREA TONIGHT...AS HIGH PRESSURE AND MORE SEASONABLE
CONDITIONS SPREAD IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 PM FRIDAY...
WATER VAPOR AND LATEST RAP DATA SUGGEST THE UPPER LOW IS NOW OVER
THE PAMLICO SOUND AND CONTINUING TO DRIFT EAST...WHILE THE STRONGEST
ASSOCIATED VORTICITY IS NOW OVER SOUTHEASTERN NC. MOIST
NORTHEASTERLY FLOW...30-35KT AT 850MB...AND ISENTROPIC LIFT OVER THE
NORTHERN COASTAL PLAIN HAS GIVEN WAY TO SOME ISENTROPIC DOWNGLIDE
THIS AFTERNOON PER RAP ANALYSIS. THE STEEPER LAPSE RATES THAT WERE
OVER CENTRAL NC THIS MORNING HAVE ALSO SHIFTED SOUTH/EAST...AND WITH
THE LOSS OF BETTER FORCING/LAPSE RATES...SHOWERS HAVE BECOME MORE
SCATTERED ACROSS THE NORTHERN PIEDMONT/COASTAL PLAIN OVER THE PAST
COUPLE HOURS. THERE ARE SOME ADDITIONAL SMALL DISTURBANCES IN THE
CYCLONIC FLOW ALOFT THAT SHOULD AID SHOWER ACTIVITY FOR A FEW MORE
HOURS...MOST NOTABLY WITH AN AREA OF SHOWERS MOVING SOUTH THROUGH
SOUTHWESTERN VA. THE LATEST HRRR SHOWS THIS CONVECTION REACHING THE
TRIAD AROUND 21Z BUT DWINDLING BEFORE MOVING MUCH FURTHER SOUTHEAST
AS HEATING...WHAT LITTLE WE HAVE HAD...IS LOST. WILL TREND POPS
DOWN FROM WEST TO EAST FOR MOST OF THE AREA...KEEPING A CHANCE POP
ACROSS THE WEST THROUGH 00Z.
TONIGHT...SKIES WILL BEGIN TO CLEAR WITHIN THE SUBSIDENCE BEHIND THE
UPPER LOW...THOUGH GUIDANCE IS IN PRETTY GOOD AGREEMENT ON SOME
LINGERING MOISTURE NEAR 5K FT...WHICH SHOULD ALSO DRIFT SOUTHEAST
WITH TIME AS THE LOW LEVEL FLOW CONTINUES TO BACK AROUND TO MORE
NORTHERLY. A LIGHT WIND WILL CONTINUE OVER THE COASTAL PLAIN...BUT
BUT TO THE WEST SOME PATCHY FOG SEEMS POSSIBLE GIVEN LITTLE CHANGE
IN AIRMASS AND LIGHT WINDS/DRYING ALOFT. SREF PROBABILITIES FOR FOG
ARE NOT VERY HIGH...SO DENSE FOG IS NOT EXPECTED. LOWS IN THE UPPER
40S.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 320 PM FRIDAY...
ONE LAST RIBBON OF VORTICITY IS EXPECTED TO DROP SOUTH ACROSS THE
COASTAL PLAIN AROUND MIDDAY...AND ALL MODELS SHOW A SIGNAL FOR AT
LEAST ISOLATED SHOWERS WITH SOME SHALLOW INSTABILITY BEFORE THE
ATMOSPHERE DRIES OUT MORE SUBSTANTIALLY AND STRONGER SUBSIDENCE SETS
IN. WILL KEEP THE SLIGHT CHANCE POP FROM ROUGHLY ROXBORO TO CLINTON
THROUGH MID AFTERNOON. HIGHS 72-76 NORTHEAST TO SOUTHWEST.
HIGHS PRESSURE WILL FINALLY BUILD OVERHEAD SATURDAY NIGHT AND SKIES
WILL FULLY CLEAR. DESPITE THE GOOD RADIATIONAL COOLING
CONDITIONS...THE AIRMASS ACTUALLY MODIFIES SLIGHTLY AND LOWS WILL BE
COMPARABLE TO TONIGHT...IF NOT WARMER IN SOME SPOTS WITH UPPER 40S
AND LOWER 50S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 240 PM FRIDAY...
HIGH PRESSURE OVERHEAD ON SUNDAY WILL SLOWLY MIGRATE OFFSHORE BUT
CONTINUE TO RIDGE WESTWARD INTO NC THROUGH TUESDAY. A WEAK TROUGH
WILL GET SANDWICHED BETWEEN THE EXITING HIGH AND A HIGH OVER THE
GREAT LAKES MID-WEEK. ALTHOUGH SOME OF THE MODELS INDICATE A SLIGHT
CHANCE FOR SOME SHOWERS IN THE FAR NORTHWEST DURING THE AFTERNOON
PERIODS MON-WED...MOST OF THE SHOWER ACTIVITY SHOULD STAY WELL TO
THE NORTH AND NORTHWEST. CENTRAL NC WILL REMAIN UNDER HIGH PRESSURE
BUT GENERALLY WEAK SURFACE FLOW FOR THE REMAINDER OF THE WEEK.
WEDNESDAY THROUGH FRIDAY GETS INTERESTING TO OUR SOUTHEAST AS BOTH
THE GFS AND ECMWF GENERATE A TROPICAL LOW PRESSURE SYSTEM OVER THE
CARIBBEAN...MOVING SLOWLY NORTH AND STALLING OFF THE CAROLINA COAST.
WHILE THERE IS STILL A GOOD DEAL OF UNCERTAINTY WITH THIS SYSTEM
GIVEN THAT IT IS FAR OUT IN THE MODEL FORECAST PERIOD...THE FACT
THAT BOTH MODELS SHOW SIMILAR FEATURES INCREASES THE CHANCE THAT
SOMETHING OF INTEREST WILL DEVELOP OFF THE SOUTHEAST ATLANTIC COAST
TOWARD THE END OF THE WEEK. REGARDLESS...ITS EVOLUTION WILL BE
SOMETHING TO WATCH. AS FOR TEMPERATURES...STILL EXPECT OUR FIRST
EXTENDED PERIOD OF 80 DEGREE DAYS...WITH HIGHS INCREASING ABOUT A
DEGREE OR SO A DAY FROM THE MID TO UPPER 70S ON SUNDAY INTO THE LOW
TO MID 80S BY FRIDAY. LOWS WILL SEE A SIMILAR TREND...INCREASING
FROM THE MID 50S SUNDAY NIGHT INTO THE UPPER 50S TO LOW 60S BY
FRIDAY NIGHT. SKIES WILL GENERALLY BE CLEAR TO PARTLY CLOUDY THROUGH
MOST OF THE PERIOD...WITH FAIRLY LIGHT WINDS...EXCEPT IN THE
SOUTHEAST AS THAT LOW HANGS OFF THE CAROLINA COAST.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 200 PM FRIDAY...
DESPITE THE CONTINUED AREAS OF LIGHT RAIN MOVING FROM NNE TO SSW
ACROSS THE AREA TODAY...CEILINGS HAVE BEEN ABLE TO LIFT A BIT INTO
THE MVFR RANGE...WITH SOME VFR CONDITIONS AT TIMES ACROSS THE
WESTERN PIEDMONT AREA. THE UPPER LOW THAT IS RESPONSIBLE FOR THE
PRECIP WILL CONTINUE TO SLOWLY MOVE EAST THIS AFTERNOON AND
EVENING...EVENTUALLY BRINGING MOST OF THE SHOWERS TO AN FROM WEST TO
EAST IN THE 20Z TO 00Z TIME FRAME. HOWEVER..THERE IS A SLIGHT
CHANCE OF SOME SOME ADDITIONAL SHOWERS CURRENTLY NEAR ROANOKE VA
MOVING SOUTH TOWARD THIS TRIAD AROUND 21Z...WHICH COULD BRING
ANOTHER SHORT PERIOD OF MVFR CEILINGS/VSBYS TO KGSO/KINT...BUT THESE
ARE EXPECTED TO DWINDLE BY SUNSET AND NOT IMPACT ANY SITES TO THE
EAST. MEANWHILE...CEILINGS WILL LIFT TO VFR AND REMAIN MOSTLY VFR
THROUGH TONIGHT AND INTO THE WEEKEND. AS THE CLOUDS LIFT AND
THIN...SOME LOW VSBYS MAY DEVELOP AFTER MIDNIGHT...WITH SREF
PROBABILITIES INDICATING AREA FROM KRDU TO KFAY HAVING THE BEST
CHANCE OF MAINLY MVFR VSBYS. HOWEVER...IF WINDS ARE LIGHT ENOUGH
BEHIND THE DEPARTING LOW AND SKIES CLEAR...SOME DENSE FOG CANT BE
RULED OUT.
OUTLOOK... VFR CONDITIONS LIKELY SAT MORNING THROUGH TUE... AS HIGH
PRESSURE BUILDS INTO THE AREA FROM THE WEST... SHIFTING OVERHEAD
LATE IN THE WEEKEND AND MOVING OFFSHORE EARLY NEXT WEEK. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...22
NEAR TERM...22
SHORT TERM...22
LONG TERM...KC
AVIATION...HARTFIELD/22
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT FRI MAY 1 2015
.SYNOPSIS...LOW PRESSURE WILL LINGER OVER AND JUST OFF THE CAROLINA
COAST TODAY... AS A STRONG UPPER LEVEL DISTURBANCE CROSSES THE
REGION. THE LOW AND DISTURBANCE WILL MOVE OFFSHORE LATE TONIGHT...
AND HIGH PRESSURE WILL BUILD IN FROM THE WEST OVER THE WEEKEND.
&&
.NEAR TERM /TODAY/...
AS OF 1030 AM FRIDAY...
THE INTENSITY OF THE RAIN OVER THE CENTRAL PIEDMONT EARLIER THIS
MORNING HAS DECREASED AS IT PUSHES SOUTH INTO THE SOUTHERN PIEDMONT
AND SANDHILLS. AN UPPER LOW WITHIN A LARGER POSITIVELY TILTED UPPER
TROUGH IS ROTATING OVERHEAD...AND THE MAIN LOBE OF STRONG VORTICITY
RESPONSIBLE FOR THAT BATCH OF RAIN IS SHIFTING MORE TOWARD SC AND
SOUTHEAST NC. MORNING OBS ANALYSIS SHOWS ANOTHER...WEAKER SHORTWAVE
NORTH OF THE LOW THAT WILL ROTATE OUR WAY THIS AFTERNOON...ALONG
WITH 30-35KT OF 850MB FLOW THAT WILL ENHANCE LOW-LEVEL CONVERGENCE.
SPC TROPOSPHERIC LAPSE RATES ARE STILL RELATIVELY STEEP WITHIN THE
UPPER LOW...WITH AN AXIS AREA OF NEAR -7C STRETCHING FROM WSW TO ENE
ACROSS THE AREA....SO SOME WEAK INSTABILITY MAY DEVELOP AGAIN THIS
AFTERNOON...THOUGH THE WIDESPREAD AND CONTINUED FEED OF RAIN FROM
THE NORTHEAST WILL LIKELY INHIBIT WARMING MORE THAN YESTERDAY.
THUS...EXPECT MAINLY SHOWERS THIS AFTERNOON BECOMING INCREASINGLY
FOCUSED EAST OF US 1. THE LATEST HRRR SHOWS SOME DEEPER CONVECTION
FIRING ACROSS THE SOUTHERN COASTAL PLAIN AFTER 18Z...AND WITH THE
FREEZING LEVEL BELOW 6K FT ON THE KGSO RAOB AND THE -10C TO -20C
LAYER CENTERED AROUND 15K FT...SOME SMALL HAIL CANT BE COMPLETELY
RULED OUT. HOWEVER...THE PROBABILITY SEEMS VERY LOW AT THIS POINT.
CURRENT TEMP FORECAST LOOKS PRETTY REASONABLE WITH LIMITED
WARMING...STRONGEST ACROSS THE SOUTHERN PIEDMONT THIS AFTERNOON AS
PRECIP MOVES OFF TO THE EAST....WITH UPPER 50S NORTHEAST TO SOME MID 60S
SOUTHWEST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 255 AM FRIDAY...
TONIGHT: EXPECT SLOW CLEARING WITH MODEST BUT DEEP SUBSIDENCE AND
DRYING IN THE WAKE OF THE EXITING LOW. SURFACE WINDS WILL BECOME
FAIRLY LIGHT FROM THE NNW WHILE 950-850 MB WINDS WILL BE MAINLY FROM
THE NNE... ALLOWING ATLANTIC MOISTURE TO CONTINUE TO SPILL IN ON THE
NW SIDE OF THE LOW... SO SCATTERED STRATOCU MAY LINGER WELL INTO THE
NIGHT. LOWS 45-50 WITH WEAK COOL AIR ADVECTION AS SURFACE HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST... BUT INITIALLY GETS
HELD UP BY THE MOUNTAINS.
SAT/SAT NIGHT: MOSTLY DRY AND QUIET WEATHER IS EXPECTED. A BAND OF
ISOLATED SHOWERS IS EXPECTED OVER THE NRN/ERN PORTIONS OF CENTRAL NC
IN THE AFTERNOON... AS A NOSE OF ENHANCED PW AND WEAK VORTICITY
DROPS TO THE SSE AROUND THE WEST SIDE OF THE OFFSHORE LOW. MOISTURE
IS UNIMPRESSIVE HOWEVER... WITH VERY SMALL FORECAST MUCAPE... SO
WILL MAINTAIN JUST ISOLATED COVERAGE... FOCUSED ON THE NW PIEDMONT
AND NRN/CENTRAL COASTAL PLAIN... AS SUGGESTED BY THE HI-RES WRF
MODEL RUNS. EXPECT MOSTLY CLEAR SKIES SAT NIGHT WITH WINDS BECOMING
LIGHT/VARIABLE AS THE CENTER OF THE SURFACE HIGH SHIFTS OVERHEAD.
HIGHS 71-76 NE TO SW... AND LOWS IN THE UPPER 40S TO LOWER 50S. -GIH
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 240 PM FRIDAY...
HIGH PRESSURE OVERHEAD ON SUNDAY WILL SLOWLY MIGRATE OFFSHORE BUT
CONTINUE TO RIDGE WESTWARD INTO NC THROUGH TUESDAY. A WEAK TROUGH
WILL GET SANDWICHED BETWEEN THE EXITING HIGH AND A HIGH OVER THE
GREAT LAKES MID-WEEK. ALTHOUGH SOME OF THE MODELS INDICATE A SLIGHT
CHANCE FOR SOME SHOWERS IN THE FAR NORTHWEST DURING THE AFTERNOON
PERIODS MON-WED...MOST OF THE SHOWER ACTIVITY SHOULD STAY WELL TO
THE NORTH AND NORTHWEST. CENTRAL NC WILL REMAIN UNDER HIGH PRESSURE
BUT GENERALLY WEAK SURFACE FLOW FOR THE REMAINDER OF THE WEEK.
WEDNESDAY THROUGH FRIDAY GETS INTERESTING TO OUR SOUTHEAST AS BOTH
THE GFS AND ECMWF GENERATE A TROPICAL LOW PRESSURE SYSTEM OVER THE
CARIBBEAN...MOVING SLOWLY NORTH AND STALLING OFF THE CAROLINA COAST.
WHILE THERE IS STILL A GOOD DEAL OF UNCERTAINTY WITH THIS SYSTEM
GIVEN THAT IT IS FAR OUT IN THE MODEL FORECAST PERIOD...THE FACT
THAT BOTH MODELS SHOW SIMILAR FEATURES INCREASES THE CHANCE THAT
SOMETHING OF INTEREST WILL DEVELOP OFF THE SOUTHEAST ATLANTIC COAST
TOWARD THE END OF THE WEEK. REGARDLESS...ITS EVOLUTION WILL BE
SOMETHING TO WATCH. AS FOR TEMPERATURES...STILL EXPECT OUR FIRST
EXTENDED PERIOD OF 80 DEGREE DAYS...WITH HIGHS INCREASING ABOUT A
DEGREE OR SO A DAY FROM THE MID TO UPPER 70S ON SUNDAY INTO THE LOW
TO MID 80S BY FRIDAY. LOWS WILL SEE A SIMILAR TREND...INCREASING
FROM THE MID 50S SUNDAY NIGHT INTO THE UPPER 50S TO LOW 60S BY
FRIDAY NIGHT. SKIES WILL GENERALLY BE CLEAR TO PARTLY CLOUDY THROUGH
MOST OF THE PERIOD...WITH FAIRLY LIGHT WINDS...EXCEPT IN THE
SOUTHEAST AS THAT LOW HANGS OFF THE CAROLINA COAST.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 200 PM FRIDAY...
DESPITE THE CONTINUED AREAS OF LIGHT RAIN MOVING FROM NNE TO SSW
ACROSS THE AREA TODAY...CEILINGS HAVE BEEN ABLE TO LIFT A BIT INTO
THE MVFR RANGE...WITH SOME VFR CONDITIONS AT TIMES ACROSS THE
WESTERN PIEDMONT AREA. THE UPPER LOW THAT IS RESPONSIBLE FOR THE
PRECIP WILL CONTINUE TO SLOWLY MOVE EAST THIS AFTERNOON AND
EVENING...EVENTUALLY BRINGING MOST OF THE SHOWERS TO AN FROM WEST TO
EAST IN THE 20Z TO 00Z TIME FRAME. HOWEVER..THERE IS A SLIGHT
CHANCE OF SOME SOME ADDITIONAL SHOWERS CURRENTLY NEAR ROANOKE VA
MOVING SOUTH TOWARD THIS TRIAD AROUND 21Z...WHICH COULD BRING
ANOTHER SHORT PERIOD OF MVFR CEILINGS/VSBYS TO KGSO/KINT...BUT THESE
ARE EXPECTED TO DWINDLE BY SUNSET AND NOT IMPACT ANY SITES TO THE
EAST. MEANWHILE...CEILINGS WILL LIFT TO VFR AND REMAIN MOSTLY VFR
THROUGH TONIGHT AND INTO THE WEEKEND. AS THE CLOUDS LIFT AND
THIN...SOME LOW VSBYS MAY DEVELOP AFTER MIDNIGHT...WITH SREF
PROBABILITIES INDICATING AREA FROM KRDU TO KFAY HAVING THE BEST
CHANCE OF MAINLY MVFR VSBYS. HOWEVER...IF WINDS ARE LIGHT ENOUGH
BEHIND THE DEPARTING LOW AND SKIES CLEAR...SOME DENSE FOG CANT BE
RULED OUT.
OUTLOOK... VFR CONDITIONS LIKELY SAT MORNING THROUGH TUE... AS HIGH
PRESSURE BUILDS INTO THE AREA FROM THE WEST... SHIFTING OVERHEAD
LATE IN THE WEEKEND AND MOVING OFFSHORE EARLY NEXT WEEK. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/22
SHORT TERM...HARTFIELD
LONG TERM...KC
AVIATION...HARTFIELD/22
AREA FORECAST DISCUSSION
NWS RALEIGH NC
200 PM EDT FRI MAY 1 2015
.SYNOPSIS...LOW PRESSURE WILL LINGER OVER AND JUST OFF THE CAROLINA
COAST TODAY... AS A STRONG UPPER LEVEL DISTURBANCE CROSSES THE
REGION. THE LOW AND DISTURBANCE WILL MOVE OFFSHORE LATE TONIGHT...
AND HIGH PRESSURE WILL BUILD IN FROM THE WEST OVER THE WEEKEND.
&&
.NEAR TERM /TODAY/...
AS OF 1030 AM FRIDAY...
THE INTENSITY OF THE RAIN OVER THE CENTRAL PIEDMONT EARLIER THIS
MORNING HAS DECREASED AS IT PUSHES SOUTH INTO THE SOUTHERN PIEDMONT
AND SANDHILLS. AN UPPER LOW WITHIN A LARGER POSITIVELY TILTED UPPER
TROUGH IS ROTATING OVERHEAD...AND THE MAIN LOBE OF STRONG VORTICITY
RESPONSIBLE FOR THAT BATCH OF RAIN IS SHIFTING MORE TOWARD SC AND
SOUTHEAST NC. MORNING OBS ANALYSIS SHOWS ANOTHER...WEAKER SHORTWAVE
NORTH OF THE LOW THAT WILL ROTATE OUR WAY THIS AFTERNOON...ALONG
WITH 30-35KT OF 850MB FLOW THAT WILL ENHANCE LOW-LEVEL CONVERGENCE.
SPC TROPOSPHERIC LAPSE RATES ARE STILL RELATIVELY STEEP WITHIN THE
UPPER LOW...WITH AN AXIS AREA OF NEAR -7C STRETCHING FROM WSW TO ENE
ACROSS THE AREA....SO SOME WEAK INSTABILITY MAY DEVELOP AGAIN THIS
AFTERNOON...THOUGH THE WIDESPREAD AND CONTINUED FEED OF RAIN FROM
THE NORTHEAST WILL LIKELY INHIBIT WARMING MORE THAN YESTERDAY.
THUS...EXPECT MAINLY SHOWERS THIS AFTERNOON BECOMING INCREASINGLY
FOCUSED EAST OF US 1. THE LATEST HRRR SHOWS SOME DEEPER CONVECTION
FIRING ACROSS THE SOUTHERN COASTAL PLAIN AFTER 18Z...AND WITH THE
FREEZING LEVEL BELOW 6K FT ON THE KGSO RAOB AND THE -10C TO -20C
LAYER CENTERED AROUND 15K FT...SOME SMALL HAIL CANT BE COMPLETELY
RULED OUT. HOWEVER...THE PROBABILITY SEEMS VERY LOW AT THIS POINT.
CURRENT TEMP FORECAST LOOKS PRETTY REASONABLE WITH LIMITED
WARMING...STRONGEST ACROSS THE SOUTHERN PIEDMONT THIS AFTERNOON AS
PRECIP MOVES OFF TO THE EAST....WITH UPPER 50S NORTHEAST TO SOME MID 60S
SOUTHWEST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 255 AM FRIDAY...
TONIGHT: EXPECT SLOW CLEARING WITH MODEST BUT DEEP SUBSIDENCE AND
DRYING IN THE WAKE OF THE EXITING LOW. SURFACE WINDS WILL BECOME
FAIRLY LIGHT FROM THE NNW WHILE 950-850 MB WINDS WILL BE MAINLY FROM
THE NNE... ALLOWING ATLANTIC MOISTURE TO CONTINUE TO SPILL IN ON THE
NW SIDE OF THE LOW... SO SCATTERED STRATOCU MAY LINGER WELL INTO THE
NIGHT. LOWS 45-50 WITH WEAK COOL AIR ADVECTION AS SURFACE HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST... BUT INITIALLY GETS
HELD UP BY THE MOUNTAINS.
SAT/SAT NIGHT: MOSTLY DRY AND QUIET WEATHER IS EXPECTED. A BAND OF
ISOLATED SHOWERS IS EXPECTED OVER THE NRN/ERN PORTIONS OF CENTRAL NC
IN THE AFTERNOON... AS A NOSE OF ENHANCED PW AND WEAK VORTICITY
DROPS TO THE SSE AROUND THE WEST SIDE OF THE OFFSHORE LOW. MOISTURE
IS UNIMPRESSIVE HOWEVER... WITH VERY SMALL FORECAST MUCAPE... SO
WILL MAINTAIN JUST ISOLATED COVERAGE... FOCUSED ON THE NW PIEDMONT
AND NRN/CENTRAL COASTAL PLAIN... AS SUGGESTED BY THE HI-RES WRF
MODEL RUNS. EXPECT MOSTLY CLEAR SKIES SAT NIGHT WITH WINDS BECOMING
LIGHT/VARIABLE AS THE CENTER OF THE SURFACE HIGH SHIFTS OVERHEAD.
HIGHS 71-76 NE TO SW... AND LOWS IN THE UPPER 40S TO LOWER 50S. -GIH
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
THE LONG TERM WILL FEATURE WARM AND DRY CONDITIONS WITH OUR FIRST
REAL STRETCH OF 80 DEGREE DAYS OF THE YEAR. THE PATTERN WILL FEATURE
SURFACE HIGH PRESSURE OFFSHORE WITH WEAK SOUTHERLY RETURN FLOW
ACROSS CENTRAL NC. THE NORTHWESTERLIES ALOFT WILL WEAKEN
CONSIDERABLY TO VERY LIGHT WINDS FOR THE FIRST HALF OF THE WEEK. IN
FACT THE GFS FORECAST SOUNDING FOR GREENSBORO ON MONDAY AFTERNOON
HAS LESS THAN 10 KTS OF WIND ALL THE WAY UP THROUGH 200 MB. WHILE
THE TEMPERATURES WILL FEEL VERY WARM IN CONTRAST TO WHAT WE HAVE
BEEN EXPERIENCING THIS PAST WEEK...THE LOW TO MID 80S WILL ONLY BE
ABOUT 5 DEGREES ABOVE NORMAL FOR THIS TIME OF THE YEAR AND NOT EVEN
CLOSE TO APPROACHING RECORDS AS THESE ARE ALL IN THE LOW TO MID 90S.
LOWS WILL BE IN THE UPPER 50S TO LOW 60S.
NOT MUCH IN THE WAY OF PRECIPITATION IS EXPECTED DURING THE PERIOD
BUT SOME CONVECTION ASSOCIATED WITH A TROUGH NORTHWEST OF THE AREA
COULD IMPINGE ON THE TRIAD ON WEDNESDAY AND THURSDAY AFTERNOONS BUT
COVERAGE...AND DURATION SHOULD BE MINIMAL AS MOST ACTIVITY SHOULD
REMAIN NORTH OF THE AREA.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 200 PM FRIDAY...
DESPITE THE CONTINUED AREAS OF LIGHT RAIN MOVING FROM NNE TO SSW
ACROSS THE AREA TODAY...CEILINGS HAVE BEEN ABLE TO LIFT A BIT INTO
THE MVFR RANGE...WITH SOME VFR CONDITIONS AT TIMES ACROSS THE
WESTERN PIEDMONT AREA. THE UPPER LOW THAT IS RESPONSIBLE FOR THE
PRECIP WILL CONTINUE TO SLOWLY MOVE EAST THIS AFTERNOON AND
EVENING...EVENTUALLY BRINGING MOST OF THE SHOWERS TO AN FROM WEST TO
EAST IN THE 20Z TO 00Z TIME FRAME. HOWEVER..THERE IS A SLIGHT
CHANCE OF SOME SOME ADDITIONAL SHOWERS CURRENTLY NEAR ROANOKE VA
MOVING SOUTH TOWARD THIS TRIAD AROUND 21Z...WHICH COULD BRING
ANOTHER SHORT PERIOD OF MVFR CEILINGS/VSBYS TO KGSO/KINT...BUT THESE
ARE EXPECTED TO DWINDLE BY SUNSET AND NOT IMPACT ANY SITES TO THE
EAST. MEANWHILE...CEILINGS WILL LIFT TO VFR AND REMAIN MOSTLY VFR
THROUGH TONIGHT AND INTO THE WEEKEND. AS THE CLOUDS LIFT AND
THIN...SOME LOW VSBYS MAY DEVELOP AFTER MIDNIGHT...WITH SREF
PROBABILITIES INDICATING AREA FROM KRDU TO KFAY HAVING THE BEST
CHANCE OF MAINLY MVFR VSBYS. HOWEVER...IF WINDS ARE LIGHT ENOUGH
BEHIND THE DEPARTING LOW AND SKIES CLEAR...SOME DENSE FOG CANT BE
RULED OUT.
OUTLOOK... VFR CONDITIONS LIKELY SAT MORNING THROUGH TUE... AS HIGH
PRESSURE BUILDS INTO THE AREA FROM THE WEST... SHIFTING OVERHEAD
LATE IN THE WEEKEND AND MOVING OFFSHORE EARLY NEXT WEEK. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/22
SHORT TERM...HARTFIELD
LONG TERM...ELLIS
AVIATION...HARTFIELD/22
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
258 PM EDT FRI MAY 1 2015
.SHORT TERM...(TONIGHT THROUGH SUNDAY)...SEEING MOSTLY CLOUDS THIS
AFTERNOON ACROSS THE NE HALF OF THE FORECAST AREA. NO SHOWERS AS OF
YET WITH A MORE STABLE AIRMASS THAN EXPECTED. LATEST HRRR MODEL RUN
WOULD ONLY BRING A STRAY SHOWER THIS EVENING TO OUR FAR NE CORNER
SO POPS WERE DROPPED ELSEWHERE...WITH A SLIGHT CHANCE OF SHOWERS
MENTIONED FOR RUSSELL/WASHINGTON VA COUNTIES AND OUR NE TN MTNS.
SLOWED DOWN THE DECREASE IN CLOUDS JUST A BIT...AND KEPT THE PATCHY
AREAS OF FOG FROM PREVIOUS GRIDS FOR LATE TONIGHT AROUND THE LAKES
& STREAMS.
UPPER AND SURFACE RIDGING STILL LOOKS TO BRING US AN AWESOME
WEEKEND WITH DRY WEATHER AND TEMPS ACTUALLY WARMING ABOVE SEASONAL
NORMALS BY SUNDAY. THE SREF AND NAM MODELS TRY TO ALLOW FOR SOME
POP UP CONVECTION IN THE SMOKY MTNS SUNDAY AFTERNOON...WHILE GFS
AND ECMWF REMAIN DRY. SAW NO REASON TO ADD SLIGHT CHANCE POPS JUST
YET FOR SUNDAY AFTERNOON...AS GFS/NAM SOUNDINGS SHOW WARMING TEMPS
ALOFT TO INHIBIT ANY CONVECTION. CLOSELY FOLLOWED THE SIMILAR NAM
AND GFS MOS TEMPS THROUGH THE SHORT TERM.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY NIGHT)...THE MODELS CONTINUE
TO SHOW A RATHER PLEASANT EXTENDED PERIOD WITH A FAIRLY EXTENDED
PERIOD OF UPPER RIDGING AND AN ATMOSPHERE THAT MAY NOT HAVE QUITE
ENOUGH MOISTURE TO GENERATE RAINFALL. THE GFS TRIES TO GENERATE A
TINY LITTLE WEAKNESS IN THE RIDGE PATTERN IN THE VICINITY OF THE
MOUNTAINS AND WITH SOME OROGRAPHICS IT SEEMS TO "OVERDO" THE CHANCE
FOR A SHOWER OR THUNDERSTORM IN THE TERRAIN. STAYED WITH THE RATHER
SMALL POPS THAT THE SUPERBLEND CREATE OVER THE FORECAST AREA AND
TRIED TO TRIM BACK TO THE MORE ORGRAPHICALLY FAVORED PARTS OF THE
VIEWING AREA NEXT WEEK. LOW LEVEL MOISTURE WILL BE GRADUALLY
INCREASING THROUGH THE WEEK AS A LIGHT SOUTHERLY COMPONENT EDGES
INTO THE SOUTHERN APPALACHIAN REGION AND THIS MAY LEAD TO AN EVER SO
SLIGHT INCREASE IN POP FOR WIDELY SCATTERED...MAINLY TERRAIN
INFLUENCED SHOWERS AND A POSSIBLE THUNDERSTORM TOWARD THE END OF THE
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 49 75 51 79 / 0 0 0 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 48 73 49 77 / 0 0 0 0
OAK RIDGE, TN 46 73 48 78 / 0 0 0 0
TRI CITIES AIRPORT, TN 43 70 44 76 / 10 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
556 PM EDT FRI MAY 1 2015
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL PROGRESS EASTWARD...OUT
OF THE REGION TONIGHT. HIGH PRESSURE WILL BUILD INTO THE REGION
THIS WEEKEND AND BE POSITIONED ACROSS OUR REGION INTO MUCH OF NEXT
WEEK. OUR NEXT BEST CHANCE OF PRECIPITATION WILL COME DURING
THE MIDDLE OF NEXT WEEK WHEN A BACKDOOR COLD FRONT APPROACHES OUR
AREA.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 555 PM EDT FRIDAY...
ADJUSTED TEMPERATURES DOWN IN RAIN COOLED LOCATIONS AND BLEND
LAMP TEMPERATURES INTO THE OVERNIGHT. MODIFIED POPS AND WEATHER
WITH LATEST WSR-88D TRENDS AND SHAPED POPS THIS EVENING INTO
TONIGHT TOWARDS A BLEND OF THE HRRR AND THE RNK WRFARW. AS THE
UPPER LOW PUSHES EAST...AREAL COVERAGE OF CONVECTION WILL
DIMINISH AND EXIT THE REGION. PATCHES OF FOG WILL DEVELOP
ESPECIALLY WHERE IT RAIN THIS AFTERNOON AND THIS EVENING AND
CONTINUE INTO THE OVERNIGHT. HELD ON TO THE THE OVERNIGHT LOW
TEMPERATURES FROM AROUND 40 DEGREES IN THE NORTHWEST MOUNTAINS TO
THE UPPER 40S IN THE PIEDMONT.
AS OF 300 PM EDT FRIDAY...
AN AREA OF SHOWERS WITH A FEW THUNDERSTORMS CONTINUES TO EXPAND IN
COVERAGE BETWEEN ROUGHLY HOT SPRINGS AND BLACKSBURG VA. THE
PRECIPITATION WAS EXPANDING TOWARDS THE S-SW. HEADING INTO THIS
EVENING...THE REGION OF PRECIPITATION WILL GRADUALLY MAKE PROGRESS
EASTWARD...IN PACE WITH THE PROGRESSION OF THE RESPONSIBLE UPPER
LEVEL LOW PRESSURE SYSTEM. COVERAGE WILL START TO DECREASE AT
SUNSET...WITH THE LAST SHOWERS EXITING THE AREA OR DISSIPATING
AROUND 11PM BETWEEN DANVILLE AND LYNCHBURG. CLOUD COVER WILL BE ON
THE DECREASE THE REMAINDER OF THE NIGHT. PATCHY LIGHT RIVER VALLEY
FOG WILL BE POSSIBLE...AND ALSO IN VALLEYS THAT RECEIVED
PRECIPITATION THIS AFTERNOON OR EVENING. LOW TEMPERATURES WILL RANGE
FROM AROUND 40 TO THE MID 40S ACROSS THE MOUNTAINS...WITH MID 40S TO
UPPER 40S ACROSS THE PIEDMONT.
ON SATURDAY...HIGH PRESSURE WILL START TO WORK ITS WAY INTO THE
REGION FROM THE WEST. ONE LATE SHORTWAVE TROUGH ROUNDING THE
BACKSIDE OF THE DEPARTING UPPER LOW IS EXPECTED TO MOVE SOUTH
THROUGH CENTRAL VIRGINIA AND NORTH CAROLINA TOMORROW AFTERNOON. THIS
FEATURE PASSING AT THE TIME OF PEAK HEATING MAY HELP TO GENERATE
SOME ISOLATED SHOWERS...GENERALLY ALONG AND EAST OF A LEXINGTON VA
TO REIDSVILLE NORTH CAROLINA LINE. THANKS TO BUILDING HEIGHTS AND
LESS CLOUD COVER...ANTICIPATE A MILDER DAY ON SATURDAY AS COMPARED TO
TODAY. HIGHS ACROSS THE MOUNTAINS WILL RANGE FROM THE MID 60S TO
NEAR 70 DEGREES...WITH LOW TO MID 70S ACROSS THE PIEDMONT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 315 PM EDT FRIDAY...
500 MB HEIGHTS GRADUALLY RISE SATURDAY NIGHT AND SUNDAY AS THE
PATTERN BECOMES MORE ZONAL. BUFKIT DATA FOR SUNDAY IN THE SOUTHWEST
COUNTY WARNING AREA SHOWED A LARGE ENOUGH LOW LEVEL LAPSE RATE AND A
LAYER OF MOISTURE THAT WOULD SUPPORT SHOWERS ISOLATED THUNDERSTORMS.
HOWEVER...THERE WILL ONLY BE MINIMAL LIFT FROM ANY VORTICITY SO
COVERAGE WILL BE CONFINED TO AREAS WITH THE BEST HEATING AND
INSTABILITY.
AIR MASS WARMS THROUGH THE PERIOD AND WILL BE CLOSE TO +10 TO +12
VALUES AT 850 MB BY THE END OF THE DAY ON MONDAY. THIS WILL PUT
MAXIMUM TEMPERATURES JUST ABOVE NORMAL MONDAY. HIGH PRESSURE WILL BE
OVER THE AREA SATURDAY NIGHT AND SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 125 PM EDT FRIDAY...
LONG WAVE PATTERN ADVERTISED BY MODELS SHOWED TROFING IN THE WESTERN
UNITED STATES AND A BROAD SOUTHEAST U.S. RIDGE. A SURFACE COLD FRONT
THE THE NORTHERN STREAM WILL BE OVER THE GREAT LAKES ON MONDAY AND
WILL PUSH SOUTH AS A BACKDOOR FRONT OVER THE MID ATLANTIC REGION
TUESDAY AND WEDNESDAY. QUESTIONABLE HOW FAR SOUTH THIS BOUNDARY GETS
HEADING INTO A LARGE RIDGE OVER THE SOUTHEAST. BEST PROBABILITY OF
PRECIPITATION WILL BE IN THE VICINITY OF THIS BOUNDARY. OTHERWISE
THE CHANCE WILL BE LIMITED TO AIRMASS TYPE THUNDERSTORMS...MAINLY IN
THE MOUNTAINS EACH AFTERNOON AND EVENING. MAXIMUM/MINIMUM
TEMPERATURES WILL REMAIN 5 TO 15 DEGREES ABOVE NORMAL TUESDAY
THROUGH FRIDAY.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
AS OF 140 PM EDT FRIDAY...
FORECAST CONFIDENCE IS MODERATE TO HIGH THROUGH SATURDAY.
MIX OF MVFR AND LOW END VFR CIGS PREVAIL ACROSS THE REGION THIS
AFTERNOON AS THE AREA AS AN AREA OF UPPER LEVEL LOW PRESSURE CROSS
THE REGION. SHOWERS HAD STARTED TO DECREASE IN COVERAGE UNTIL
RECENTLY. NOW THE FOCUS FOR NEW DEVELOPMENT WILL BE ALONG A KLWB-
KBCB LINE...AND THEN POINTS EAST AS THE CONVECTION TRANSITIONS
EASTWARD...FOLLOWING THE TRACK OF THE UPPER LOW. BRIEF...ISOLATED
IFR CONDITIONS WILL BE POSSIBLE UNDER THE HEAVIER SHOWERS AND
STORMS THAT DEVELOP.
OVERNIGHT...CLOUDS WILL DECREASE IN COVERAGE AS DRIER AIR STARTS
TO WORK ITS WAY INTO THE AREA...AND PRECIPITATION WILL DECREASE IN
COVERAGE THROUGH THE EVENING HOURS. LINGERING BOUNDARY LAYER
MOISTURE MAY DEVELOP INTO SOME PATCHY FOG IN THE RIVER AND
MOUNTAIN VALLEYS AS WINDS TREND LIGHTER. BETWEEN KBLF-KLWB...A
SHALLOW IFR CIG MAY DEVELOP AS LIGHT NORTHWEST FLOW GENERATES A
SMALL UPSLOPE COMPONENT IN THIS AREA. ON SATURDAY...ANY SUB-VFR
OVERNIGHT CONDITIONS WILL TRANSITION FAIRLY QUICKLY TO VFR AFTER
SUNRISE.
THE VISIBILITY SENSOR AT THE ASOS AT KBLF CONTINUES TO
MALFUNCTION. WILL CONTINUE WITH AMD NOT SKED APPENDED TO ITS TAF.
FORECAST CONFIDENCE IS HIGH SATURDAY AFTERNOON THROUGH MONDAY
NIGHT.
OTHER THAN SOME PATCHY LATE NIGHT/EARLY MORNING RIVER VALLEY FOG
IN THE TYPICAL LOCATIONS...VFR CONDITIONS ARE EXPECTED THROUGH
MONDAY NIGHT.
FORECAST CONFIDENCE TUESDAY THROUGH WEDNESDAY IS MODERATE.
LOOK FOR AN INCREASING AMOUNT OF SHOWERS AND LOWER BASED CLOUDS
TUESDAY AND WEDNESDAY AS LOW LEVEL MOISTURE FLOW INCREASES ACROSS
THE AREA...AND A BACKDOOR FRONT DRIFTS SOUTH TOWARD OR INTO OUR
AREA.
&&
.EQUIPMENT...
AS OF 330 PM EDT FRIDAY...
THE VISIBILITY SENSOR AT THE BLUEFIELD...KBLF...ASOS MAY ALTERNATE
BETWEEN AVAILABLE AND UNAVAILABLE UNTIL SUCH TIME APPROPRIATE
CORRECTIVE MEASURES CAN BE COMPLETED.
THE NOAA WEATHER RADIO AT ROANOKE VIRGINIA...WXL60...WHICH
BROADCASTS AT A FREQUENCY OF 162.475 MHZ...IS BACK ON THE AIR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS/KK
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...DS
EQUIPMENT...DS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
356 PM MDT FRI MAY 1 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 354 PM MDT FRI MAY 1 2015
SHOWERS AND THUNDERSTORMS ARE ON THE UPTICK ALONG THE INTERSTATE 80
CORRIDOR IN SOUTHEAST WY THIS AFTERNOON. AS EXPECTED...THE GREATEST
COVERAGE HAS BEEN IN ALBANY IN LARAMIE COUNTIES WITH ENHANCED LOWER
LEVEL CONVERGENCE ALONG THE LARAMIE RANGE. THE KCYS RADAR LOOP ALSO
SHOWS NUMEROUS BOUNDARIES IN THE VICINITY OF CYS...LIKELY PLAYING A
ROLE IN CONVECTIVE EVOLUTION. CLOUDS CLEARED LATE THIS AM...HELPING
PUSH SFC TEMPS INTO THE 55-65 DEGREE RANGE AMID DECENT LLVL MOISTURE
WITH DEWPOINTS IN THE MID 40S F. THIS BENEATH STEEP MID LEVEL LAPSE
RATES ON THE ORDER OF 8-9 DEG C/KM IS CONTRIBUTING TO SBCAPES ON THE
ORDER OF 1500 J/KG PER THE 21Z SPC MESOANALYSIS. GFS AND NAM BUFKIT
SOUNDINGS BOTH SHOW H5 FLOW AROUND 30 KTS...WHICH COMBINED WITH GOOD
VEERING IN THE SFC-500 MILLIBAR LAYER IS CONTRIBUTING TO EFFECTIVE
BULK SHEAR VALUES FAVORABLE FOR ROTATING UPDRAFTS (35-45 KTS). COULD
SEE A HAIL THREAT EVOLVE WITH SOME CELLS...BUT DO NOT EXPECT TO SEE
MORE THAN ONE OR TWO SEVERE STORMS. OPTED TO MAINTAIN SMALL HAIL AND
GUSTY WIND WORDING IN THE OFFICIAL FORECAST. LATEST HRRR HAS CHANGED
VERY LITTLE FROM THIS MORNING...AND APPEARS TO BE ACCURATELY SHOWING
CONVECTIVE ELEMENTS BETWEEN LARAMIE AND CHEYENNE. FOR THAT REASON...
WILL MAINTAIN LIKELY POPS FOR THOSE AREAS. CONVECTIVE COVERAGE WILL
DWINDLE OVERNIGHT WITH THE LOSS OF DAYTIME HEATING/INSTABILITY.
QUASI-ZONAL FLOW ALOFT PERSISTS INTO SATURDAY. A SERIES OF MID LEVEL
DISTURBANCES WILL TRAVERSE THE FLOW OVER THE CENTRAL ROCKIES...ONCE
AGAIN PROMOTING AFTERNOON CONVECTION CHANCES. THE DAY 2 SPC OUTLOOK
HAS SHIFTED THE MARGINAL RISK EAST OF OUR CWA...WHICH MAKES SENSE AS
THE LATEST IN-HOUSE WRF PLACES THE BEST INSTABILITY AXIS EAST OF AN
ALLIANCE TO SIDNEY LINE BETWEEN 18-20Z SAT. POTENTIAL FOR WIDESPREAD
THUNDERSTORMS WILL DEPEND ON THE TIMING OF THE DRYLINE. GFS AND NAM
BOTH PUSH THIS FEATURE EAST OF THE CWA BY EARLY TO MID AFTERNOON...
BUT MODELS TEND TO MIX DRYLINES A BIT QUICKLY. LATER SHIFTS MAY NEED
TO ADJUST POPS ACCORDINGLY IF IT APPEARS THE LOW-LEVEL CONVERGENCE
ZONE WILL HANG ANY FURTHER WEST. A MUCH WARMER DAY APPEARS TO BE ON
TAP TOMORROW FOR THE PLAINS WITH WESTERLY DOWNSLOPE FLOW...AND 700
MILLIBAR TEMPS AROUND 8-10 DEG C.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 354 PM MDT FRI MAY 1 2015
THIS PERIOD WILL BE DOMINATED BY GENERALLY CONSISTENT SOUTHWEST
FLOW ACROSS THE INTERMOUNTAIN WEST AS YET ANOTHER LARGE SCALE
TROUGH IS CARVED INTO THE WRN CONUS. MOISTURE ADVECTION ALONG WITH
DIFFICULT TO TIME SHORTWAVES EMBEDDED WTIHIN THIS FLOW WILL SET
THE STAGE FOR A RELATIVELY UNSETTLED PERIOD. THIS BEGINS ON
SUNDAY/MONDAY AS WEAK SFC BOUNDARY SETTLES SOUTH ACROSS THE PLAINS
HANGING UP AROUND THE FRONT RANGE. MEANWHILE...RELATIVELY WEAK
SHORTWAVE ENERGY WILL LIFT ACROSS THIS BOUNDARY AND WHEN COMBINED
WITH WEAK INSTABILITY PROGS (SBCAPE 300- 500 J/KG) WILL PRODUCE
AFTERNOON/EVENING CONVECTION BOTH DAYS. A STRONGER EJECTING TROUGH
WILL MOVE THROUGH THE CWFA TUE/WED. BUT WITH MORE MOISTURE AND
THICKER CLOUD CANOPY...INSTABILITIES ARE PROGD TO BE LESS.
SOUTHWEST FLOW PERSISTS INTO THURSDAY WITH THE NEXT TROUGH
SWINGING OUT OF THE DEEPENING WEST COAST TROUGH FOR FRIDAY OR
FRIDAY NIGHT...DEPENDING ON THE MEDIUM RANGE GUIDANCE OF CHOICE.
ISOLATED TO SCATTERED LATE DAY SHOWERS AND THUNDERSTORMS ARE HARD
TO ARGUE WITH REALLY ANY DAY NEXT WEEK. SO HAVE KEPT PRECIP
CHANCES FAIRLY BROAD BRUSH BUT NOT WIDESPREAD NEXT WEEK. SUNDAY
WILL BE THE WARMEST DAY OF THE WEEK WITH HIGHS REACHING THE
60S/70S. HIGHS WILL FALL BACK INTO THE 60S GENERALLY MON-FRI.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1134 AM MDT FRI MAY 1 2015
AVIATION CONCERNS CENTER AROUND TIMING AND PLACEMENT OF CONVECTION
THIS AFTERNOON AND EARLY EVENING...WHILE CAN ALWAYS BE A TRICKY.
ALL SITES WITH THE EXCEPTION OF KCYS WILL BEGIN THE PERIOD IN
VFR. PESKY STRATOCU DECK WILL KEEP BKN020-030 AGL IN PLACE AT KCYS
AT LEAST FOR THE NEXT HOUR OR TWO. LATEST HRRR INITIATE
-SHRA/-TSRA DEVELOPMENT ALONG THE DIFFERENTIAL HEATING AXIS (NR
THE LARAMIE RANGE W OF KCYS) BETWEEN THIS STRATOCU DECK AND THE
CLEARING TO THE WEST 20-21Z. CONFIDENCE HAS INCREASED ENOUGH TO
ADD A TEMPO -TSRA GROUP INTO KCYS. CONFIDENCE IS LOWER WEST OF
THIS AREA OF DIFFERENTIAL HEATING...SO HAVE KEPT VCTS IN KCYS.
HAVE ADDED VCTS TO THE NEBRASKA PANHANDLE SITES AS WELL LATER THIS
AFTERNOON AS WHATEVER CONVECTION DOES MANAGE TO DEVELOP TRANSLATES
EAST. IF THIS ACTIVITY DOES IMPACT AN AIRIFIELD...EXPECT MVFR
CIGS/VSBYS ALONG WITH BRIEF +RA...THE POTENTIAL FROM SMALL GS
ALONG WITH GUSTY WINDS. AM NOT CONFIDENT ENOUGH IN TIMING OR
PLACEMENT TO INCLUDE IN THE TAF...BUT WILL BE MONITORING RADAR
TRENDS CLOSELY THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 354 PM MDT FRI MAY 1 2015
FIRE WEATHER CONCERNS WILL BE ON THE LOW SIDE WITH DAILY CHANCES FOR
SHOWERS AND THUNDERSTORMS. WHILE ANY GIVEN STORM MAY PRODUCE GUSTY
AND ERRATIC WINDS...NO DRY LIGHTNING IS EXPECTED. AFTERNOON RELATIVE
HUMIDITY VALUES SHOULD REMAIN ABOVE 15 PERCENT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLH
LONG TERM...CAH
AVIATION...CAH
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1134 AM MDT FRI MAY 1 2015
.UPDATE...
ISSUED AT 1048 AM MDT FRI MAY 1 2015
AREA WEBCAMS AND VISIBLE SATELLITE IMAGERY SHOW FOG AND/OR LOW
STRATUS RAPIDLY DIMINISHING ACROSS PORTIONS OF CARBON AND ALBANY
COUNTIES THIS AM. CLOUD COVER HAS BEEN SLOW TO ERODE OVER THE CO
FRONT RANGE WITH WEAK LLVL UPSLOPE...BUT CLOUDS ARE THINNING AND
LLVL MIXING SHOULD GIVE WAY TO AT LEAST PARTLY SUNNY SKIES AS WE
HEAD INTO THE AFTERNOON. OUR ATTENTION THEN SHIFTS TO CONVECTIVE
POTENTIAL LATER TODAY. FORCING IS NOT AS PRONOUNCED AS PREVIOUS
DAYS...BUT INSTABILITY SHOULD BE THERE WITH STEEP MIDLEVEL LAPSE
RATES AND GOOD LLVL MOISTURE WITH SURFACE DEWPOINTS IN THE MID
40S. IF WE CAN BREAK OUT OF THE CLOUDS...OUR LOCAL WRF SUGGESTS
SBCAPE NEAR 750-1000 J/KG. 0-6KM SHEAR VECTORS ARE WESTERLY AT
AROUND 40 KTS...SUPPORTING POTENTIAL FOR ROTATING UPDRAFTS AND
HAIL PRODUCTION. THE HRRR INITIATES CONVECTION AROUND 20Z OVER
ALBANY AND LARAMIE COUNTIES...SO WENT AHEAD AND INCREASED POPS
INTO THE LIKELY CATEGORY. ALSO ADDED SMALL HAIL AND GUSTY WINDS
GIVEN THE THERMODYNAMIC/KINEMATIC ENVIRONMENT. WE COULD HAVE A
SEVERE STORM OR TWO...BUT OPTED NOT TO MENTION IN THE GRIDS AS
UNCERTAINTIES REMAIN WITH HOW CLOUDS WILL IMPACT COVERAGE OF
STRONGER STORMS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 300 AM MDT FRI MAY 1 2015
PATTERN WILL BE CHARACTERIZED BY A ZONAL FLOW ALOFT WITH SEVERAL
WEAK IMPULSES PASSING ACROSS THE CWA IN THIS FLOW PATTERN. A SFC
BOUNDARY WILL REMAIN BANKED UP ALONG THE HIGHER TERRAIN OF SE
WYOMING TODAY BEFORE ERODING EASTWARD OVERNIGHT INTO SATURDAY.
THIS BOUNDARY SHOULD INTERACT WITH THESE WEAK DISTURBANCES AND
SOME INSTABILITY TO PRODUCE SCTD SHOWERS AND A FEW STORMS MAINLY
OVER SE WYOMING TODAY. CAPE VALUES RANGE FROM ABOUT 500-1000J/KG
AGAINST THE LARAMIE RANGE THIS AFTERNOON BUT SHEAR VALUES RATHER
LOW SO A FEW STRONGER STORMS POSSIBLE. ACTIVITY SHOULD MOVE
OUT/DISSIPATE THIS EVENING LEAVING A QUIET NIGHT TONIGHT. MORE OF
THE SAME EXPECTED FOR SATURDAY AND SUNDAY EXCEPT AFTERNOON AND
EVENING CONVECTION SHOULD MAKE MORE PROGRESS EASTWARD AS THE SFC
BOUNDARY SHIFTS EAST. CAPE VALUES MUCH LESS OVERALL EXCEPT OVER
PARTS OF THE PANHANDLE WHERE THEY EXCEED 1500 J/KG LATE IN THE
MORNING BEFORE SHIFTING EAST OF THE CWA. WARMER TEMPS FOR SATURDAY
THEN THE NEXT COOL FRONT WILL PASS ACROSS EARLY SUNDAY RESULTING
IN ABOUT 5-15 DEGREES OF COOLING...GREATEST OVER THE PANHANDLE.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI MAY 1 2015
MUCH OF THE LONG TERM REMAINS UNSETTLED AS GUIDANCE CONTINUES TO
SHOW ALMOST DAILY PRECIP CHANCES OVER THE CWFA.
AREA REMAINS UNDER EASTERLY TO SOUTHEASTERLY UPSLOPE FLOW SUNDAY
NIGHT INTO MONDAY AS A SURFACE HIGH OVER WESTERN SOUTH DAKOTA
REMAINS NEARLY STATIONARY.
EACH DAY THERE LOOKS TO BE PIECES OF ENERGY BEING DRAWN NORTH INTO
THE AREA FROM THE DESERT SOUTHWEST THAT INTERACTS WITH A BOUNDARY
THAT IS STALLED ALONG THE LARAMIE RANGE. MONDAY
AFTERNOON...CONVECTION IS CONCENTRATED MAINLY ACROSS OUR WESTERN
ZONES...BUT AS THE LOW PRESSURE SYSTEM MOVES INTO COLORADO
TUESDAY...OUR EASTERN ZONES GET SOME PRETTY GOOD RAINFALL. BEST
PRECIP CHANCES APPEAR TO BE ALONG THE WYOMING/COLORADO BORDER
ALONG INTERSTATE 80.
UPPER LOW SLOW TO MOVE OUT OF COLORADO AND WE SHOULD SEE
WIDESPREAD CHANCES FOR SHOWERS AND THUNDERSTORMS WEDNESDAY ACROSS
THE ENTIRE CWFA. FINALLY BY THURSDAY...UPPER LOW MOVES NORTHEAST
INTO THE DAKOTAS. NOT MUCH OF A BREAK IN PRECIP THOUGH AS A SECOND
SHORTWAVE MOVES IN BEHIND THIS ONE FOR FRIDAY. AREA WILL CONTINUE
TO SEE ABOVE NORMAL CHANCES FOR MUCH NEEDED RAINFALL INTO THE END
OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1134 AM MDT FRI MAY 1 2015
AVIATION CONCERNS CENTER AROUND TIMING AND PLACEMENT OF CONVECTION
THIS AFTERNOON AND EARLY EVENING...WHILE CAN ALWAYS BE A TRICKY.
ALL SITES WITH THE EXCEPTION OF KCYS WILL BEGIN THE PERIOD IN
VFR. PESKY STRATOCU DECK WILL KEEP BKN020-030 AGL IN PLACE AT KCYS
AT LEAST FOR THE NEXT HOUR OR TWO. LATEST HRRR INITIATE
-SHRA/-TSRA DEVELOPMENT ALONG THE DIFFERENTIAL HEATING AXIS (NR
THE LARAMIE RANGE W OF KCYS) BETWEEN THIS STRATOCU DECK AND THE
CLEARING TO THE WEST 20-21Z. CONFIDENCE HAS INCREASED ENOUGH TO
ADD A TEMPO -TSRA GROUP INTO KCYS. CONFIDENCE IS LOWER WEST OF
THIS AREA OF DIFFERENTIAL HEATING...SO HAVE KEPT VCTS IN KCYS.
HAVE ADDED VCTS TO THE NEBRASKA PANHANDLE SITES AS WELL LATER THIS
AFTERNOON AS WHATEVER CONVECTION DOES MANAGE TO DEVELOP TRANSLATES
EAST. IF THIS ACTIVITY DOES IMPACT AN AIRIFIELD...EXPECT MVFR
CIGS/VSBYS ALONG WITH BRIEF +RA...THE POTENTIAL FROM SMALL GS
ALONG WITH GUSTY WINDS. AM NOT CONFIDENT ENOUGH IN TIMING OR
PLACEMENT TO INCLUDE IN THE TAF...BUT WILL BE MONITORING RADAR
TRENDS CLOSELY THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 300 AM MDT FRI MAY 1 2015
CONCERNS TO REMAIN LOW THROUGH THE WEEKEND INTO EARLY NEXT WEEK
WITH NEARLY DAILY CHANCES FOR SHOWERS AND A FEW STORMS...BUT NO
DRY LIGHTNING. WEATHER FACTORS REMAINING NON-CRITICAL.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...RE
LONG TERM...GCC
AVIATION...CAH
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1117 AM MDT FRI MAY 1 2015
.UPDATE...
ISSUED AT 1048 AM MDT FRI MAY 1 2015
AREA WEBCAMS AND VISIBLE SATELLITE IMAGERY SHOW FOG AND/OR LOW
STRATUS RAPIDLY DIMINISHING ACROSS PORTIONS OF CARBON AND ALBANY
COUNTIES THIS AM. CLOUD COVER HAS BEEN SLOW TO ERODE OVER THE CO
FRONT RANGE WITH WEAK LLVL UPSLOPE...BUT CLOUDS ARE THINNING AND
LLVL MIXING SHOULD GIVE WAY TO AT LEAST PARTLY SUNNY SKIES AS WE
HEAD INTO THE AFTERNOON. OUR ATTENTION THEN SHIFTS TO CONVECTIVE
POTENTIAL LATER TODAY. FORCING IS NOT AS PRONOUNCED AS PREVIOUS
DAYS...BUT INSTABILITY SHOULD BE THERE WITH STEEP MIDLEVEL LAPSE
RATES AND GOOD LLVL MOISTURE WITH SURFACE DEWPOINTS IN THE MID
40S. IF WE CAN BREAK OUT OF THE CLOUDS...OUR LOCAL WRF SUGGESTS
SBCAPE NEAR 750-1000 J/KG. 0-6KM SHEAR VECTORS ARE WESTERLY AT
AROUND 40 KTS...SUPPORTING POTENTIAL FOR ROTATING UPDRAFTS AND
HAIL PRODUCTION. THE HRRR INITIATES CONVECTION AROUND 20Z OVER
ALBANY AND LARAMIE COUNTIES...SO WENT AHEAD AND INCREASED POPS
INTO THE LIKELY CATEGORY. ALSO ADDED SMALL HAIL AND GUSTY WINDS
GIVEN THE THERMODYNAMIC/KINEMATIC ENVIRONMENT. WE COULD HAVE A
SEVERE STORM OR TWO...BUT OPTED NOT TO MENTION IN THE GRIDS AS
UNCERTAINTIES REMAIN WITH HOW CLOUDS WILL IMPACT COVERAGE OF
STRONGER STORMS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 300 AM MDT FRI MAY 1 2015
PATTERN WILL BE CHARACTERIZED BY A ZONAL FLOW ALOFT WITH SEVERAL
WEAK IMPULSES PASSING ACROSS THE CWA IN THIS FLOW PATTERN. A SFC
BOUNDARY WILL REMAIN BANKED UP ALONG THE HIGHER TERRAIN OF SE
WYOMING TODAY BEFORE ERODING EASTWARD OVERNIGHT INTO SATURDAY.
THIS BOUNDARY SHOULD INTERACT WITH THESE WEAK DISTURBANCES AND
SOME INSTABILITY TO PRODUCE SCTD SHOWERS AND A FEW STORMS MAINLY
OVER SE WYOMING TODAY. CAPE VALUES RANGE FROM ABOUT 500-1000J/KG
AGAINST THE LARAMIE RANGE THIS AFTERNOON BUT SHEAR VALUES RATHER
LOW SO A FEW STRONGER STORMS POSSIBLE. ACTIVITY SHOULD MOVE
OUT/DISSIPATE THIS EVENING LEAVING A QUIET NIGHT TONIGHT. MORE OF
THE SAME EXPECTED FOR SATURDAY AND SUNDAY EXCEPT AFTERNOON AND
EVENING CONVECTION SHOULD MAKE MORE PROGRESS EASTWARD AS THE SFC
BOUNDARY SHIFTS EAST. CAPE VALUES MUCH LESS OVERALL EXCEPT OVER
PARTS OF THE PANHANDLE WHERE THEY EXCEED 1500 J/KG LATE IN THE
MORNING BEFORE SHIFTING EAST OF THE CWA. WARMER TEMPS FOR SATURDAY
THEN THE NEXT COOL FRONT WILL PASS ACROSS EARLY SUNDAY RESULTING
IN ABOUT 5-15 DEGREES OF COOLING...GREATEST OVER THE PANHANDLE.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI MAY 1 2015
MUCH OF THE LONG TERM REMAINS UNSETTLED AS GUIDANCE CONTINUES TO
SHOW ALMOST DAILY PRECIP CHANCES OVER THE CWFA.
AREA REMAINS UNDER EASTERLY TO SOUTHEASTERLY UPSLOPE FLOW SUNDAY
NIGHT INTO MONDAY AS A SURFACE HIGH OVER WESTERN SOUTH DAKOTA
REMAINS NEARLY STATIONARY.
EACH DAY THERE LOOKS TO BE PIECES OF ENERGY BEING DRAWN NORTH INTO
THE AREA FROM THE DESERT SOUTHWEST THAT INTERACTS WITH A BOUNDARY
THAT IS STALLED ALONG THE LARAMIE RANGE. MONDAY
AFTERNOON...CONVECTION IS CONCENTRATED MAINLY ACROSS OUR WESTERN
ZONES...BUT AS THE LOW PRESSURE SYSTEM MOVES INTO COLORADO
TUESDAY...OUR EASTERN ZONES GET SOME PRETTY GOOD RAINFALL. BEST
PRECIP CHANCES APPEAR TO BE ALONG THE WYOMING/COLORADO BORDER
ALONG INTERSTATE 80.
UPPER LOW SLOW TO MOVE OUT OF COLORADO AND WE SHOULD SEE
WIDESPREAD CHANCES FOR SHOWERS AND THUNDERSTORMS WEDNESDAY ACROSS
THE ENTIRE CWFA. FINALLY BY THURSDAY...UPPER LOW MOVES NORTHEAST
INTO THE DAKOTAS. NOT MUCH OF A BREAK IN PRECIP THOUGH AS A SECOND
SHORTWAVE MOVES IN BEHIND THIS ONE FOR FRIDAY. AREA WILL CONTINUE
TO SEE ABOVE NORMAL CHANCES FOR MUCH NEEDED RAINFALL INTO THE END
OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 647 AM MDT FRI MAY 1 2015
PATCHY FOG AND LOW CLOUDS RESIDE WEST OF THE LARAMIE RANGE THIS
MORNING. KRWL DOWN NOW IN STRATUS THAT IS EXPECTED TO CONTINUE
UNTIL 15Z OR SO. MVFR CONDITIONS HERE AT KCYS SHOULD IMPROVE BY
MID MORNING WITH HEATING. AFTERNOON CONVECTION FOR KCYS...KLAR AND
POSSIBLY THE SOUTHERN PANHANDLE AIRPORTS.
&&
.FIRE WEATHER...
ISSUED AT 300 AM MDT FRI MAY 1 2015
CONCERNS TO REMAIN LOW THROUGH THE WEEKEND INTO EARLY NEXT WEEK
WITH NEARLY DAILY CHANCES FOR SHOWERS AND A FEW STORMS...BUT NO
DRY LIGHTNING. WEATHER FACTORS REMAINING NON-CRITICAL.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...RE
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RE