Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/30/15
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1000 AM PDT Thu May 28 2015
.Synopsis...
Daytime temperatures 10 to 15 degrees above normal over the next
few days as high pressure slides across the west coast. Cooler
early next week with a slight chance of showers and thunderstorms
over the northern Sacramento valley and surrounding mountains as
the tail end of a Pacific trough brushes through.
&&
.Discussion...
High pressure building over Norcal today with the ridge axis
shifting inland Fri/Sat as an upper trof approaches the coast by
Sun. Weakening short wave moving through the ridge will be spreading
some high cloudiness over Norcal today...then clearing/thinning of
cloud cover tonite. Ft Ord Profiler and KOAK RAOB this morning
showed the marine layer had lowered to around 2200 ft from
yesterday. Some stratus briefly advected into the Srn Sac Vly this
morning...but has now dissipated. During the next couple of
mornings...increasing subsidence from high pressure is expected to
continue to suppress the marine layer and limit the potential for
intrusion into the valley. With less of a marine influence and
weaker onshore gradients a warming trend is expected for the next
couple of days. Onshore gradients increase again on Sun with the
approaching trof yielding cooler temps and a chance of showers over
our nrn zones.
Instability progs high-lite the usual spots...Lassen Park and near
the Crest of the Coastal range the next couple of days...where
topographic forcing/convergence is likely to cause cumuliform
cloudiness and possibly brief convection. Have added a small area of
convection in these general areas for the next couple of days per
the HRRR and WRF.
.Previous Discussion...
Overall airmass warms under the ridge with daytime highs today
forecast to run about 10 to 15 degrees above normal. Friday looks to
be the warmest day as upper ridge axis centers over the west coast.
On Saturday...daytime highs drop down just a bit as the upper ridge
axis shifts east of the state in response to an eastern Pacific
trough forecast to approach the coast. This system is forecast to
move onto the coast by Sunday afternoon or evening bringing a threat
of showers to the coast range...the northern mountains and possibly
the northern Sacramento valley. Stability progs show possibly
enough instability over the coast range for thunderstorms but
conditions are more stable farther east so removed afternoon/evening
thunderstorm threat there. Most locations Sunday will just see some
increased high cloud cover...increased southwest winds and about a 5
to 10 degree drop in daytime temperatures.
&&
.Extended Discussion (Monday through Thursday)
Models continue to forecast several short wave troughs through
northern portions of California Monday into Tuesday. Dynamics and
moisture look limited with main impact being synoptic cooling
with increased onshore flow. Locally gusty southwest to west winds
expected through the Delta and over higher mountain terrain. A
slight chance of showers and afternoon thunderstorms are possible
mainly over the mountains north of I-80 through this period.
Weak ridging moves through Wednesday followed by weak upper
troughing Thursday. Slight warming of the AMS depicted through
midweek by models with mid to upper 80s for highs in the Central
and mainly 60s to around 80 for the mountains and foothills.
&&
.Aviation...
Upr rdg blds ovr the fcst area nxt 24 hrs. Mnly VFR conds for Intr
NorCal exc lcl MVFR/IFR cigs in ST vcnty Carquinez Strait/Delta til
18-19z Thu and again from 08z-19z Fri. Lcl SWly sfc wnd gsts to arnd
25 kts poss thru Delta.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
319 AM MDT THU MAY 28 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 216 AM MDT THU MAY 28 2015
A DISTURBANCE AHEAD OF A WK UPPER LEVEL TROUGH WILL MOVE INTO NERN
CO BY EARLY AFTN. MEANWHILE AT THE SFC THERE WILL BE A LOW OVER
THE PLAINS SOMEWHERE BETWEEN AKRON AND LIMON WITH A CONVERGENCE
ZONE OVER THE FAR ERN PLAINS. APPEARS CONVECTION MAY DVLP ALONG
THIS CONVERGENCE ZONE BY LATE MORNING WITH ADDITIONAL ACTIVITY
DEVELOPING ACROSS THE REST OF NERN CO BY EARLY AFTN AS DISTURBANCE
MOVES ACROSS. ALTHOUGH PRECIPITABLE WATER VALUES WILL BE NR AN
INCH OVER THE FAR ERN PLAINS...WITH INCREASING MID LVL FLOW BY
AFTN STORMS WILL BE RATHER FAST MOVING SO WILL NOT ISSUE A FLASH
FLOOD WATCH. THERE WILL BE SOME THREAT FOR A FEW SVR STORMS OVER
PARTS OF THE PLAINS WITH LARGE HAIL AND GUSTY WINDS. OVER THE
HIGHER TERRAIN THERE WILL BE SCT SHOWERS AND TSTMS DUE TO
FAVORABLE LAPSE RATES. AS FOR HIGHS WILL KEEP READINGS IN THE
LOWER TO MID 70S OVER NERN CO.
BY TONIGHT THE DISTURBANCE WILL MOVE EAST OF THE AREA BY EARLY
EVENING AS THE WK UPPER LEVEL TROUGH MOVES INTO WY. PCPN WILL
GRADUALLY DECREASE THRU THE EARLY EVENING HOURS ACROSS THE PLAINS
WITH SOME LINGERING ACTIVITY OVER THE HIGHER TERRAIN. AS THE MAIN
UPPER LEVEL TROUGH SLOWLY MOVES SE INTO NRN CO LATE TONIGHT THERE
MAYBE ANOTHER CHC OF SHOWERS TOWARDS MORNING AS A FNT MOVES ACROSS
THE PLAINS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 216 AM MDT THU MAY 28 2015
AN UPPER TROUGH WILL PASS OVER COLORADO FRIDAY...WITH COOLER AIR
PUSHING INTO THE AREA IN UPSLOPE FLOW. ALL MODELS HAVE SHOWN A
BRIEF BREAK IN THE EARLY MORNING FROM PRECIPITATION...BEFORE THE
POST FRONTAL NORTHERLY WINDS TURN MORE NORTHEASTERLY. HAVE ADDED
THIS DETAIL INTO THE FORECAST. MAIN PLUME OF MOISTURE WILL PUSH IN
FOR THE AFTERNOON AND EVENING AS HIGH SURFACE PRESSURE MAKES ITS
MAIN PUSH INTO THE STATE. HAVE NOT ADJUSTED EXPECTED RAINFALL
AMOUNTS MUCH...EXPECT AROUND A QUARTER TO A HALF INCH OF RAIN OVER
THE FRONT RANGE MOUNTAINS...FOOTHILLS AND PALMER DIVIDE...AND ONE
TO TWO TENTHS OF AN INCH OVER THE EASTERN PLAINS AS WELL AS IN THE
HIGH COUNTRY WEST OF THE DIVIDE. WITH CLOUD COVER ALL DAY AND
SCATTERED TO WIDESPREAD RAIN SHOWERS...TEMPERATURES WILL STAY IN
THE MID 60S FOR THE PLAINS. MOUNTAINS WILL LIKELY SEE READINGS IN
THE 50S TO LOW 60S. SNOW LEVELS WILL BE DOWN AROUND 9000 EARLY
FRIDAY MORNING...INCREASE TO NEAR 11,000 FEET IN THE AFTERNOON
THEN BACK DOWN AROUND 10,000 FT AT NIGHT. EXPECT A FEW INCHES OF
WET SNOW AT THE HIGHER ELEVATIONS. COULD SEE MORE CONVECTION AND
THUNDERSTORMS OVER THE HIGH COUNTRY...BUT ALL ARE EXPECTED TO BE
WEAK. FEEL LIKE CONVECTION WILL BE DONE FRIDAY EVENING
HIGH SURFACE PRESSURE OVER THE PLAINS SATURDAY WILL KEEP STABLE
UPSLOPE FLOW OVER THE PLAINS WHILE SOME WARMING WILL OCCUR AT
MIDLEVELS AND AFFECT THE HIGH COUNTRY. EXPECT WARMER CONDITIONS
OVER THE MOUNTAINS WITH AFTERNOON AND EVENING STORMS...WHICH MAY
DRIFT EAST OVER THE WESTERN PLAINS ...BUT STABLE AIR WILL INHIBIT
THEM MAKING IT TOO FAR.
SUNDAY THROUGH TUESDAY WILL FEATURE WARMING AS AN UPPER RIDGE
MOVES OVERHEAD AND A SURFACE TROUGH DEEPENS ALONG THE LEE OF THE
ROCKIES....HELPING TO WARM MORE QUICKLY WITH DOWNSLOPE EFFECTS.
LOOKING AT EXTENDED MOS GUIDANCE...HAVE INCREASED TEMPERATURES FOR
SUNDAY THROUGH TUESDAY TO BE MORE IN LINE WITH THIS GUIDANCE.
THIS EARLY JUNE WARM UP MAY BE SHORT LIVED HOWEVER AS BOTH GFS AND
EC MODELS HAVE ANOTHER WEATHER SYSTEM MOVING OVER THE PACNW WITH
TRENDS OF COOLER AND WETTER WEATHER APPROACHING THE STATE AGAIN.
HOWEVER THE JET SEEMS TO STAY FURTHER NORTH THAN WE`VE BEEN
EXPERIENCING THIS MONTH...SO NOT AS WET AND COLD.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 216 AM MDT THU MAY 28 2015
A SFC LOW WAS JUST EAST OF DIA EARLY THIS MORNING WITH WNW WINDS. A
NARROW STRATUS DECK HAS FORMED JUST BEHIND THE LOW WITH CEILINGS
DOWN TO 800 FEET AT DIA. THE LATEST HRRR SHOW THESE LOW CLOUDS
MAY LINGER UNTIL 12Z BEFORE BREAKING UP. AS FOR TSTM CHANCES IT
APPEARS BEST CHC WOULD BE IN THE 19Z-22Z RANGE. WINDS WILL BECOME
LIGHT AND VARIABLE AROND 15Z AND THEN LIGHT ESE BY MIDDAY. BY 20Z
THEY WILL BECOME MORE NWLY AND THEN TREND BACK TO MORE SSW BY
EARLY EVENING. OVERNIGHT WILL KEEP WINDS DRAINAGE.
&&
.HYDROLOGY...
ISSUED AT 216 AM MDT THU MAY 28 2015
A FEW THUNDERSTORMS OVER THE PLAINS COULD PRODUCE UP TO AN INCH
OF RAIN THIS AFTERNOON. OTHERWISE RAIN AMOUNTS WILL BE IN THE
QUARTER INCH TO HALF INCH RANGE ACROSS THE REST OF THE AREA.
FRIDAY`S UPSLOPE EVENT WILL STILL LIKELY HAVE WIDESPREAD RAIN
SHOWERS...BUT PRECIPITATION AMOUNTS ARE TRENDING SLIGHTLY
DOWNWARD. EXPECT 0.25-0.5" OVER THE FRONT RANGE
MOUNTAINS...FOOTHILLS AND ADJACENT WESTER PLAINS. AMOUNTS OF LESS
THAN TWO TENTHS ARE EXPECTED OVER THE EASTERN PLAINS. SOME HEAVIER
SHOWERS ARE POSSIBLE IN THE AFTERNOON AGAINST THE HIGHER
TERRAIN...WHICH MAY ADD MORE WATER TO THE AREA RIVERS...BUT AT
THIS TIME THE FLOODING THREAT IS NOT THAT GREAT.
FLOOD WARNINGS CONTINUE FOR THE SOUTH PLATTE RIVER AT KERSEY AS
WELL AS THE CACHE LA POUDRE AT GREELEY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...KRIEDERMAN
AVIATION...RPK
HYDROLOGY...RPK
AREA FORECAST DISCUSSION
NWS TAUNTON MA
958 PM EDT FRI MAY 29 2015
.SYNOPSIS...
DRY WEATHER TONIGHT AND SATURDAY THANKS TO AN AREA OF HIGH
PRESSURE. A COLD FRONT WILL SLOWLY MOVE ACROSS THE REGION
SUNDAY...THEN STALL SOUTH OF NEW ENGLAND EARLY NEXT WEEK. THIS
WILL BRING A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS
SUNDAY...AND A PERIOD OF RAIN EARLY NEXT WEEK. HIGH PRESSURE
BRINGS DRY WEATHER FOR THE LATTER PART OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
1000 PM UPDATE...
OVERALL TREND IN THE FORECAST IS ON TRACK FOR THIS EVENING. HIGH
LEVEL CLOUDS CONTINUE TO MOVE OVERHEAD WITHIN WAA PATTERN.
NOTICES STRATUS AND FOG BEGINNING TO PUSH OVER ACK OVER THE PAST
HOURS. ALSO A SITE OR TWO ALONG LONG ISLAND IS SEEING THE
STRATUS/FOG AS WELL.
STILL A LOT OF UNCERTAINTY ON THE POTENTIAL FOR DENSE FOG ALONG
THE COAST LINES OVERNIGHT INTO TOMORROW MORNING. HRRR SEEMS TO BE
TO BULLISH ON THE TIMING AND HOW FAR NORTH THE FOG WILL SPREAD.
UNLIKE THE PAST FEW NIGHTS...BUFKIT SOUNDINGS DO SHOW THE
POTENTIAL FOR FOG ALONG THE SOUTH COAST. WILL CONTINUE TO MONITOR
OVER THE NEXT FEW HOURS ON THE FOG POTENTIAL.
PREVIOUS DISCUSSION...
THE FOG SHOULD LINGER LONGEST ALONG THE NORTH SHORE AND MAY
TAKE AN EXTRA COUPLE OF HOURS TO LEAVE THERE.
SATELLITE IMAGERY ALSO SHOWS A FOG BANK SOUTH OF NANTUCKET. AS
WINDS TURN OUT OF THE SOUTH THEY SHOULD ADVECT THE FOG NORTH
TOWARD NEW ENGLAND. LOW CONFIDENCE ON HOW FAR NORTH THESE LOW
CLOUDS ADVECT...BUT PROBABLY AFFECT THE SOUTH COAST AND PERHAPS AS
FAR NORTH AS THE MA PIKE. SOME FOG IS ALSO EXPECTED AND CAN/T RULE
OUT A PERIOD OF DENSE FOG ACROSS SOUTHEAST NEW ENGLAND...BUT
CONFIDENCE ON THAT IS LOW.
OTHERWISE...A DRY NIGHT OTHER THAN PERHAPS A BIT OF MIST TOWARD
DAYBREAK ALONG WITH THE FOG ACROSS THE SOUTHEAST NEW ENGLAND COAST.
LOW TEMPS MAINLY IN THE UPPER 50S TO THE LOWER 60S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
***A WARM AND SOMEWHAT HUMID SATURDAY AFTERNOON IS ON TAP INLAND
FROM THE SOUTH COAST***
HIGH PRESSURE MOVING OFF THE COAST WILL ALLOW A WARMER AND MORE
HUMID AIRMASS TO OVERSPREAD SOUTHERN NEW ENGLAND ON SATURDAY. LOW
CLOUDS THAT FORM SOUTH OF MA PIKE SHOULD SCOUR OUT BY SATURDAY
AFTERNOON IF NOT EARLIER FOR MOST OF THE REGION. HOWEVER...LOW
CLOUDS AND FOG PATCHES MAY LINGER ACROSS THE IMMEDIATE SOUTH
COAST/CAPE/ISLANDS.
OTHERWISE...HIGH TEMPS SHOULD REACH INTO THE MIDDLE TO UPPER 80S TO
THE NORTHWEST OF A BOSTON TO PROVIDENCE LINE. THE WARMEST OF THOSE
READINGS SHOULD BE FOUND IN THE MERRIMACK VALLEY. TO THE SOUTHEAST
OF A BOSTON TO PROVIDENCE LINE...GUSTY SOUTHWEST WINDS WILL HOLD
HIGH TEMPS IN THE 70S TO NEAR 80. IN FACT...SOUTHWEST WIND GUSTS OF
20 TO 30 MPH ARE EXPECTED FOR MOST OF THE REGION SATURDAY AFTERNOON
WITH GOOD MIXING.
UPPER LEVEL RIDGING SHOULD RESULT IN MAINLY A DRY DAY ACROSS THE
REGION. BEST FORCING/INSTABILITY AND DYNAMICS WILL BE WELL TO OUR
NORTHWEST WITH AN APPROACHING COLD FRONT. JUST A LOW RISK OF A SPOT
SHOWER/THUNDERSTORM LATE SATURDAY AFTERNOON/EARLY EVENING ACROSS
NORTHWEST MA.
SATURDAY NIGHT...
A COLD FRONT WILL BE SLOWLY APPROACHING OUR REGION FROM THE WEST. A
SOUTHWEST LOW LEVEL JET WILL RESULT IN A MILD NIGHT...WITH LOW TEMPS
ONLY DROPPING TO BETWEEN 60 AND 65. DRY WEATHER SHOULD DOMINATE THE
FIRST PART OF THE NIGHT...BUT WE MAY SEE SOME SCATTERED SHOWERS AND
PERHAPS AN EMBEDDED THUNDERSTORM OR TWO DEVELOP OVERNIGHT. THIS IS
RESPONSE TO LOW LEVEL JET AND A BURST OF INSTABILITY. ACTIVITY WILL
PROBABLY BE HIT AND MISS THROUGH DAYBREAK SUNDAY...WITH THE BULK OF
IT TO THE NORTHWEST OF I-95. BULK OF LOW CLOUDS SHOULD BE CONFINED
TO THE SOUTHEAST NEW ENGLAND COAST. ENOUGH WIND IN THE BOUNDARY
LAYER MAY PREVENT A LOT OF FOG FROM DEVELOPING...BUT STILL CAN NOT
RULE OUT SOME DEVELOPING.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
BIG PICTURE...
CHANGEABLE PATTERN THROUGH THE WEEK. UPPER RIDGE MOVES OFFSHORE
SUNDAY. UPPER TROUGH SLOWLY CROSSES THE NORTHEAST USA EARLY WEEK.
UPPER RIDGE FROM THE WESTERN USA THEN SHIFTS EAST OVER THE EASTERN
USA LATE WEEK.
DIFFERENCES AMONG THE MODELS REGARDING TIMING WITH THE UPPER TROUGH
EARLY WEEK WITH THE GGEM THE FASTEST AND ECMWF SLOWEST. WE USED A
MODEL CONSENSUS IN TIMING.
THE DAILIES...
SUNDAY THROUGH TUESDAY... COLD FRONT EITHER OVER OR JUST NORTH OF
NORTHERN MASS SUNDAY MORNING WILL MOVE SOUTH ACROSS THE REGION
DURING THE DAY. PRECIPITABLE WATER VALUES ALONG AND AHEAD OF THE
FRONT WILL BE 1.50 TO 1.75 INCHES WHICH IS AROUND 2 STD DEV ABOVE
NORMAL. TOTALS OF 47-49 AND SHOWALTERS OF 0 TO -2. ALL OF THIS
SUGGESTS SUFFICIENT MOISTURE FOR SHOWERS AND ENOUGH INSTABILITY OVER
THE LOW LEVEL CONVERGENCE TO SUPPORT A FEW THUNDERSTORMS.
DIFFERENCES AMONG THE MODELS ON TIMING THE FROPA BUT ALL MOVE IT
SOUTH OF THE COAST BY SUNDAY EVENING. THE FRONT IS THEN ALIGNED WITH
THE UPPER FLOW AND STALLS. SHORTWAVE MOVING THROUGH THE GREAT LAKES
IS FORECAST TO GENERATE A WAVE ALONG THE FRONT WHICH CROSSES THE
APPALACHIANS MONDAY AND PASSES SOUTH OF NEW ENGLAND TUESDAY. THIS
ALONG WITH HIGH PRESSURE IN EASTERN CANADA SHOULD BRING A COOL
NORTHEAST FLOW TO THE REGION MONDAY AND TUESDAY. MEANWHILE A
SOUTHWEST FLOW CONTINUES ABOVE 5OOO FEET AGL AND SUPPIES LIFT AND
MOISTURE OVER THE TOP. WE WILL MAINTAIN LIKELY POPS MONDAY
DIMINISHING TO CHANCE POPS DURING THE DAY TUESDAY AS THE LOW MOVES
EAST.
WEDNESDAY THROUGH FRIDAY... HIGH PRESSURE BUILDS SURFACE AND ALOFT
BRINGING DRY WEATHER TO SOUTHERN NEW ENGLAND. WITH THE DEMISE OF THE
NORTHEAST MARINE FLOW...MIXING SHOULD RETURN WITH HEIGHTS REACHING
AT LEAST 875 MB WEDNESDAY AND AT LEAST 850 MB THURSDAY AND FRIDAY.
TEMPERATURES AT THE TOP OF THE MIXED LAYER EACH DAY SUGGEST MAX SFC
TEMPS IN THE MID 60S TO LOW 70S WEDNESDAY...70S TO NEAR 80
THURSDAY...AND 75-85 FRIDAY.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT...LOW TO MODERATE CONFIDENCE. SHIFTING WINDS SHOULD PUSH
THE FOG OFF TO THE NORTHEAST SITES TONIGHT. ADDITIONAL FOG SOUTH
OF NEW ENGLAND WILL MOVE UP TO THE SOUTH COAST AND MAY SPREAD
ACROSS CT- RI-SE MASS OVERNIGHT. THIS WILL MEAN IFR/LIFR
CIGS/VSBYS DEVELOPING ALONG THE SOUTH COAST OVERNIGHT AND POSSIBLY
SPREADING ACROSS CAPE COD AND ISLANDS...AND PVD AND BDL.
SATURDAY...MODERATE CONFIDENCE. ANY LOW CLOUDS/FOG PATCHES SOUTH OF
PIKE PROBABLY SCOUR OUT BY LATE MORNING/EARLY AFTERNOON...EXCEPT
CAPE/ISLANDS WHERE THEY MAY LINGER INTO THE AFTERNOON. DRY WEATHER
EXPECTED...ALTHOUGH THERE IS A LOW RISK OF A SPOT
SHOWER/THUNDERSTORM ACROSS NORTHWEST MA LATE IN THE AFTERNOON/EARLY
EVENING.
SATURDAY NIGHT...MODERATE CONFIDENCE. MAINLY VFR TO MARGINAL MVFR
CIGS EXCEPT FAR SOUTHEAST NEW ENGLAND COAST WHERE IFR CIGS/VSBYS ARE
POSSIBLE. SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM OR TWO WILL
BE POSSIBLE MAINLY ACROSS THE INTERIOR WITH THE HIGHER RISK DURING
THE OVERNIGHT HOURS.
KBOS TERMINAL...LOW CONFIDENCE IN TAF EARLY TONIGHT. LIFR CIGS AND
VSBYS WILL LINGER OVER OR NEAR THE AIRPORT FOR THE FIRST COUPLE OF
HOURS OF THE TAF. ONCE WINDS TURN SOUTH OR SOUTHWEST THAT SHOULD
MOVE THE FOG OFF TO THE NORTHEAST ACROSS CAPE ANN AND OFFSHORE.
LOW CONFIDENCE IN THIS TIMING.
KBDL TERMINAL...LOW TO MODERATE CONFIDENCE IN TAF. MVFR TO IFR CIGS
MAY DEVELOP AFTER MIDNIGHT...THEN DISSIPATE AFTER SUNRISE.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE CONFIDENCE.
SUNDAY... COLD FRONT MOVES ACROSS SOUTHERN NEW ENGLAND FROM NORTH TO
SOUTH. VFR CIGS/VSBYS WITH AREAS OF MVFR IN SHOWERS/THUNDERSTORMS.
SOUTHWEST WINDS TO START...BECOMING NORTHEAST BY EVENING. WINDS AT
2000-3000 FEET AGL START SOUTHWEST 25-35 KNOTS AND BECOME NORTHEAST
25 TO 30 KNOTS BY EVENING. SOUTHWEST WINDS LINGER THROUGH THE DAY AT
OR ABOVE 5000 FEET. THIS MAY CREATE SOME LOW LEVEL WIND SHEAR AT
TIMES...DIRECTIONAL SHEAR IN THE VERTICAL IS LIKELY AND SPEED SHEAR
POSSIBLY.
MONDAY THROUGH TUESDAY... MVFR/IFR CIGS AND VSBYS WITH BEST CHANCE
OVER THE COASTAL PLAIN AND EASTERN SLOPES OF THE WORCESTER HILLS.
SHOWERS POSSIBLE THROUGH BOTH DAYS.
WEDNESDAY... VFR WITH A NORTH-NORTHWEST WIND.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
TONIGHT...MODERATE TO HIGH CONFIDENCE. WEAK PRESSURE GRADIENT WILL
KEEP WINDS/SEAS BELOW SMALL CRAFT ADVISORY THRESHOLDS.
HOWEVER...AREAS OF FOG MAY DEVELOP OVERNIGHT ACROSS OUR SOUTHERN
WATERS BUT ITS UNCERTAIN IF IT WILL BECOME DENSE.
SATURDAY...MODERATE TO HIGH CONFIDENCE. EXCELLENT MIXING OVER THE
LAND WILL GENERATE NEAR SHORE SMALL CRAFT WIND GUSTS OF 25 TO 30
KNOTS SATURDAY AFTERNOON. IN ADDITION...SOUTHEAST SWELL WILL
GENERATE 5 FOOT SEAS ACROSS THE OUTER-WATERS. THEREFORE...SMALL
CRAFT HEADLINES POSTED FOR ALL WATERS. AREAS OF FOG MAY BE LOCALLY
DENSE IN THE MORNING ALONG THE SOUTH COAST...SHOULD IMPROVE SOMEWHAT
BY AFTERNOON.
SATURDAY NIGHT...MODERATE TO HIGH CONFIDENCE. NEAR SHORE SMALL
CRAFT WIND GUSTS SHOULD DIMINISH SATURDAY EVENING. HOWEVER...5 FOOT
SWELL WILL CONTINUE ACROSS THE OUTER-WATERS. SOME FOG POSSIBLE SAT
NIGHT...BUT PROBABLY NOT AS WIDESPREAD AS TONIGHT GIVEN SOME MORE
BOUNDARY LAYER WIND.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE CONFIDENCE.
SUNDAY...SMALL CRAFT ADVISORY MAY BE NEEDED ON SOME OF THE WATERS. A
COLD FRONT CROSSES THE EASTERN WATERS DURING THE DAY. THE FRONT
CROSSES THE SOUTHERN WATERS SUNDAY EVENING. SHOWERS AND POSSIBLE
THUNDERSTORMS ALONG AND AHEAD OF THE FRONT. EXPECTING SOUTHWEST
GUSTS TO 20 KNOTS AHEAD OF THE FRONT. WINDS THEN SHIFT TO NORTHEAST
AND EAST BEHIND THE FRONT WITH GUSTS TO 20 KNOTS FROM THAT
DIRECTION. SEAS LINGER AROUND 5 FEET ON THE OUTER WATERS.
MONDAY-TUESDAY...SMALL CRAFT ADVISORY MAY BE NEEDED ESPECIALLY ON
THE EASTERN WATERS. NORTHEAST WINDS GUSTING 20 TO 25 KNOTS EACH DAY.
SEAS 5 TO 8 FEET ON THE EASTERN MASS WATERS...AND 3 TO 5 FEET ON THE
SOUTHERN WATERS.
WEDNESDAY...A SMALL CRAFT ADVISORY MAY BE NEEDED...MAINLY ON THE
EASTERN WATERS. DIMINISHING NORTHEAST TO NORTH WINDS. SEAS OF 5 FEET
MAY LINGER ON THE EASTERN WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 10 PM EDT SATURDAY FOR
ANZ230>237-251.
SMALL CRAFT ADVISORY FROM 2 PM SATURDAY TO 8 AM EDT SUNDAY FOR
ANZ250-254>256.
&&
$$
SYNOPSIS...WTB/FRANK
NEAR TERM...FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...WTB
AVIATION...WTB/FRANK
MARINE...WTB/FRANK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
804 PM EDT FRI MAY 29 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE ATLANTIC THROUGH SATURDAY
AFTERNOON. A COLD FRONT WILL APPROACH SATURDAY NIGHT...AND MOVE
THROUGH ON SUNDAY. THE FRONT WILL STALL JUST TO THE SOUTH AS WEAK
LOW PRESSURE RIDES ALONG IT. HIGH PRESSURE WILL THEN BUILD IN FROM
THE NORTH LATE TUESDAY INTO WEDNESDAY...AND SHIFT TO THE SOUTH
ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AFTER A MOSTLY SUNNY AFTERNOON...WITH ONLY A FEW CU OVER INTERIOR
SE CT AND THIN HIGH CLOUDS FROM NYC NORTH/WEST...ATTENTION WILL
TURN TO DEVELOPMENT OF LOW STRATUS AND PATCHY FOG TONIGHT.
IN FACT...PUBLIC REPORTED FOG JUST OUT OVER THE WATER SE
SUFFOLK...AND MONTAUK WEB CAM SHOWS REDUCED VSBYS. LATEST HRRR AND
NARRE PROB OF VSBY BELOW 1 MILE WARRANTS ISSUANCE OF DENSE FOG FOR
SOME OF THE MARINE ZONES. WILL WATCH FOR EASTERN LI AND SE CT.
COMBO OF ONSHORE FLOW AND LOW LEVEL RADIATIONAL COOLING UNDER
CLEAR SKIES WILL PROMOTE THE EXPANSION OF STRATUS AND FOG
NORTH/WEST AFTER DARK...INTO THE REST OF LONG ISLAND AND SOUTHERN
CT AFTER MIDNIGHT AND POSSIBLY ALL AREAS LATE TONIGHT.
LOW TEMPS WILL BE IN THE UPPER 50S ACROSS ERN LONG ISLAND AND SE
CT...LOWER 60S MOST ELSEWHERE...AND MID 60S INVOF NYC.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
MORNING LOW CLOUDS SHOULD BE SLOW TO BURN OFF ESPECIALLY ACROSS
LONG ISLAND AND COASTAL CT. SFC RIDGING AND SOUTHERLY FLOW SHOULD
KEEP THE AIR MASS STABLE OVER MOST OF THE CWA FROM NYC EAST...
WHILE ENOUGH LATE DAY INSTABILITY MAY DEVELOP WELL NORTH/WEST OF
NYC AHEAD OF AN ADVANCING WEAK SHORTWAVE TO SPARK ISOLD-SCT
SHOWERS AND POSSIBLY A TSTM. AFTERNOON COASTAL SEA BREEZES WILL BE
ENHANCED BY A TIGHT PRESSURE GRADIENT...AND COULD AGAIN SEE GUSTS
20-30 MPH LATE IN THE AFTERNOON ESPECIALLY ACROSS LONG ISLAND.
HIGH TEMPS SHOULD BE 80-85 INLAND AND IN THE 70S ALONG THE COAST.
CONVECTIVE POTENTIAL SHOULD WANE SAT EVENING WITH LOSS OF DAYTIME
HEATING...THEN COULD SEE SCT SHOWERS AND POSSIBLY A TSTM LATE AT
NIGHT AS A COLD FRONT APPROACHES. PREFER SLIGHTLY SLOWER/DRIER
FRONTAL APPROACH PER NAM/ECMWF VS FASTER/WETTER GFS...AND SO HAVE
SCALED BACK GUIDANCE POP...WITH ONLY CHANCE LATE AT NIGHT MAINLY
INLAND. LOW TEMPS SHOULD BE IN THE LOWER AND MID 60S.
THERE IS A HIGH RISK OF RIP CURRENTS AT THE ATLANTIC BEACHES
SATURDAY. STRONGEST RIP CURRENTS WOULD OCCUR DURING THE AFTERNOON
AS THE SOUTHERLY WINDS INCREASE.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
COLD FRONT SLOWLY CROSSES THROUGH THE CWA THROUGH ON SUNDAY WITH
SHOWERS BECOMING LIKELY. CAPE IS SUFFICIENT FOR A CHANCE OF
THUNDERSTORMS. WITH THE COLD FRONT BECOMING ALIGNED WITH THE UPPER
FLOW ALONG WITH A RELATIVELY SLOW STORM MOTION FORECAST...WILL NEED
TO KEEP AN EYE OUT FOR THE POTENTIAL OF TRAINING CELLS AND AT LEAST
MINOR URBANIZED/SMALL STREAM FLOODING DURING THE AFTERNOON AND
EVENING HOURS.
THE COLD FRONT STALLS TO OUR SOUTH...THEN A WAVE OF LOW PRESSURE
FORMS ALONG IT...PASSING OVER OR JUST SOUTH OF US ON TUESDAY. MODELS
DISAGREE ON HOW QUICKLY THIS HAPPENS WITH ECMWF CONTINUING TO BE THE
SLOWEST WITH THE PASSAGE. HAVE GONE WITH LIKELY POPS THROUGH MONDAY
NIGHT BEFORE TAPERING TO CHC ON TUESDAY. MIGHT EVENTUALLY NEED TO
INCREASE POPS FOR TUESDAY...ESPECIALLY OVER EASTERN ZONES. ELEVATED
CAPE WILL BE JUST SOUTH OF US...SO NO MENTION OF THUNDER FROM LATE
SUNDAY NIGHT THROUGH TUESDAY.
AFTER NEAR-NORMAL HIGHS ON SUNDAY...MONDAY AND TUESDAY SHOULD BE
BELOW NORMAL WITH RAIN/CLOUDS/ONSHORE FLOW.
WILL MAINTAIN A DRY FORECAST FOR WEDNESDAY...FAVORING THE MORE
PROGRESSIVE MODELS. HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING
LOW. HIGHER CONFIDENCE THAT THURSDAY WILL BE DRY WITH THE CENTER OF
THE HIGH PASSING THROUGH. TEMPS RETURNING TO NORMAL. FRIDAY LIKELY
REMAINS DRY AS WELL WITH THE HIGH OFFSHORE AND THE NEXT COLD FRONT
WELL OFF TO THE NW.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE REMAINS OFFSHORE THROUGH SATURDAY WITH A COLD FRONT
APPROACHING FROM THE GREAT LAKES. THIS WILL KEEP THE AREA UNDER A
PROLONGED PERIOD OF SOUTHERLY FLOW.
CONDITIONS EARLY THIS EVENING ARE VFR AND ARE EXPECTED TO CONTINUE
TO BE VFR THROUGH THE EVENING EXCEPT FOR KISP AND KGON WHERE LOW
STRATUS/FOG WILL BECOME AN INCREASING POSSIBILITY. DIFFICULT TO
DETERMINE WHICH ONE WILL PROVE MORE IMPACT.
FARTHER WEST...IFR/MVFR CONDITIONS WILL BE DELAYED UNTIL AFTER
06Z TONIGHT...AND THEN QUICKLY IMPROVE TO VFR AFTER 12Z SAT. THERE
WILL BE A CHANCE OF SHOWERS AND A SLIGHT CHANCE THUNDERSTORMS LATE
SAT AFTN THROUGH SAT EVE WITH MVFR POSSIBLE...BUT CONFIDENCE TOO
LOW TO INCLUDE IN TAF AT THIS TIME.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: TIMING OF LOWERING AND IMPROVING CONDITIONS
COULD BE 2-3 HOURS OFF.
KLGA FCSTER COMMENTS: TIMING OF LOWERING AND IMPROVING CONDITIONS
COULD BE 2-3 HOURS OFF. CONDITIONS MAY VERY WELL STAY VFR/MVFR
LATE TONIGHT.
KEWR FCSTER COMMENTS: TIMING OF LOWERING AND IMPROVING CONDITIONS
COULD BE 2-3 HOURS OFF. CONDITIONS MAY VERY WELL STAY VFR/MVFR
LATE TONIGHT.
KTEB FCSTER COMMENTS: TIMING OF LOWERING AND IMPROVING CONDITIONS
COULD BE 2-3 HOURS OFF. CONDITIONS MAY VERY WELL STAY VFR LATE
TONIGHT.
KHPN FCSTER COMMENTS: TIMING OF LOWERING AND IMPROVING CONDITIONS
COULD BE 2-3 HOURS OFF. CONDITIONS MAY VERY WELL STAY VFR/MVFR
LATE TONIGHT.
KISP FCSTER COMMENTS: TIMING OF LOWERING AND IMPROVING CONDITIONS
COULD BE 2-3 HOURS OFF. IFR COULD ARRIVE 1-2 HOURS EARLIER THAN
FORECAST.
.OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
.SATURDAY NIGHT-TUESDAY MORNING...GUSTY S WINDS UP TO 20 KT SAT
NIGHT BUT PERHAPS AT MORE OCCASIONAL FREQUENCY. MVFR OR LOWER AT
TIMES IN SHOWERS. THUNDERSTORMS POSSIBLE SATURDAY NIGHT- SUNDAY
NIGHT.
.TUESDAY AFTERNOON/NIGHT...BECOMING VFR.
.WEDNESDAY...VFR.
&&
.MARINE...
POOR VSBYS FOR MANY AREAS TONIGHT IN FOG.
QUIET CONDS THROUGH EARLY SAT AFTERNOON. COASTAL SEA BREEZES
ENHANCED BY A TIGHTENING PRESSURE GRADIENT SHOULD THEN HELP
GENERATE FREQUENT GUSTS UP TO 25 KT ALONG THE NEAR SHORE WATERS
SOUTH OF LONG ISLAND LATE SAT AFTERNOON INTO SAT EVENING...SO HAVE
RAISED SCA FOR THE OCEAN AND THE SOUTH SHORE BAYS.
OCEAN SEAS MAY FLIRT WITH 5 FT LATE SAT AFTERNOON AND SAT NIGHT.
WITH SUSTAINED WINDS REMAINING MOSTLY 15 KT OR LESS HELD THEM
AT 4 FT.
SCA CONDS WILL PROBABLY BE ON THE OCEAN WATERS SUNDAY AND SUNDAY
NIGHT...HOWEVER THERE COULD BE AN EXTENDED PERIOD DURING THIS
TIME FRAME WHERE THE CRITERIA IS NOT BEING MET. E WINDS OTHERWISE
INCREASE ON MONDAY WITH SCA CONDS PROBABLE ON MOST OF THE WATERS.
WINDS THEN SUBSIDE ON TUESDAY...BUT A LINGERING SWELL MAY KEEP
OCEAN SEAS AT SCA LEVELS THROUGH THE DAY...AND PROBABLY THROUGH
MOST OF WED AS WELL.
&&
.HYDROLOGY...
FORECAST RAIN AMOUNTS FROM SUNDAY THROUGH MONDAY NIGHT CURRENTLY
RANGE FROM 1.5 TO 2.5 INCHES. AS USUAL...LOCALLY HIGHER AMOUNTS WILL
BE POSSIBLE DUE TO SCATTERED THUNDERSTORMS. THESE THUNDERSTORMS ARE
MORE LIKELY TO OCCUR SUNDAY AFTERNOON AND EVENING. THERE IS A THREAT
OF FLOODING...BUT MINOR URBAN/POOR DRAINAGE/SMALL STREAM FLOODING
WOULD BE MORE LIKELY. FLASH FLOODING IS NOT OUT OF THE QUESTION
SUNDAY AFTERNOON AND NIGHT...BUT CONFIDENCE IS NOT HIGH ENOUGH TO
INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK...ESPECIALLY WITH ANTECEDENT
DRY CONDITIONS FOR THE PAST MONTH OR SO.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM TO 11 PM EDT SATURDAY FOR
ANZ345-350-353-355.
&&
$$
SYNOPSIS...JC/GOODMAN
NEAR TERM...GOODMAN/PW
SHORT TERM...GOODMAN
LONG TERM...JC
AVIATION...JM
MARINE...JC/GOODMAN/PW
HYDROLOGY...JC
AREA FORECAST DISCUSSION
NWS ALBANY NY
959 AM EDT THU MAY 28 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL TRACK THROUGH THE REGION WITH SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS THROUGH THIS AFTERNOON. WEAK
HIGH PRESSURE WILL BUILD OVER NEW YORK AND NEW ENGLAND INTO
FRIDAY...BEFORE SLIDING OFFSHORE FRIDAY NIGHT. WARMER AND MORE
HUMID AIR WILL RETURN TO THE REGION SATURDAY. A COLD FRONT WILL
DROP SLOWLY SOUTHEAST THROUGH THE REGION SATURDAY NIGHT AND
SUNDAY...AND STALL TO OUR SOUTH MONDAY. IT WILL BRING MORE SHOWERS
AND THUNDERSTORMS AND COOLER WEATHER FOR THE NEW WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE WEAK COLD FRONT...AND UPPER LEVEL TROUGH ARE TRACKING THROUGH
CENTRAL NY. THERE ARE A FEW SCATTERED SHOWERS IN THE WESTERN
MOHAWK VALLEY AND SOUTHERN ADIRONDACKS ALONG THE WIND SHIFT
BOUNDARY...WITH SOUTH WINDS SHIFTING TO WEST BEHIND THE WEAK COLD
FRONT. THERE IS A BIT OF A DROP IN DEW POINTS BEHIND THE WEAK COLD
FRONT AS WELL...ADDING A LITTLE BIT TO THE LOW LEVEL FORCING
ALONG THE FRONT. THE LOW LEVEL WIND SHIFT AND DEW POINT BOUNDARY
WILL SUPPORT DEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER EASTERN NY...WITH THE AXIS OF THIS SCATTERED
ACTIVITY REACHING A LINE FROM LAKE GEORGE TO THE CAPITAL DISTRICT
TO THE EASTERN CATSKILLS AROUND NOON...THEN FROM SOUTHERN
BERKSHIRE COUNTY TO THE SOUTHERN TACONICS AND LITCHFIELD COUNTY
3-4 PM. MESOSCALE MODELS SUCH AS THE HRRR SUPPORT THIS.
BASED ON AREA 12Z SOUNDINGS AND SATELLITE IMAGERY...SOME
INTERVALS OF SUN AND CLOUDS SHOULD RESULT IN HEATING DURING THE
DAY AND WILL CREATE SOME MARGINAL INSTABILITY. HOWEVER RELATIVELY
WARM ALOFT AND ENVIRONMENTAL WINDS THROUGH A DEEP LAYER ARE
MODERATE BUT WITH SUCH WEAK LOW LEVEL FORCING AND INSTABILITY...
MAYBE SOME ISOLATED MARGINAL SEVERE WIND GUSTS IN ANY
THUNDERSTORMS FROM THE TACONICS THROUGH WESTERN NEW ENGLAND.
WORDING GUSTY WINDS INTO THE FORECAST FOR ANY THUNDERSTORMS THIS
AFTERNOON.
BY SUNSET...ALL SHOWERS/TSTMS WILL HAVE EXITED EASTERN NY AND
WESTERN NEW ENGLAND. HIGHS TODAY WILL BE IN THE UPPER 60S OVER
THE WESTERN ADIRONDACKS...AND THE 70S TO MID 80S ELSEWHERE. WINDS
WILL SHIFT FROM SOUTH OR SOUTHWEST TO WEST OR NORTHWEST DURING THE
DAY AS THE COLD FRONT MOVES THROUGH WITH WIND GUSTS OF 20 TO 25
MPH POSSIBLE.
THE STORM PREDICTION CENTER (SPC) HAS PLACED A SMALL PORTION OF
EAST CENTRAL NY...SOUTHERN VT AND BERKSHIRE COUNTY IN A SLIGHT
RISK OF SEVERE TSTMS THROUGH THIS AFTERNOON...WITH MUCH OF THE
REST OF THE FORECAST AREA (EXCEPT FOR THE NORTHWEST THIRD)...IN A
MARGINAL RISK. MORE DETAILS CAN BE FOUND IN THE DAY 1 OUTLOOK FROM
SPC.
SKIES WILL CLEAR QUICKLY LATE THIS AFTN AND EVENING...WITH MAINLY
CLEAR TO CLEAR SKIES FORECAST OVERNIGHT. IT WILL BE COOLER AND
LESS HUMID TONIGHT WITH LOWS IN THE UPPER 40S AND 50S.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
FRI 500HPA HGTS/RIDGE BRIEFLY BUILD OVER RGN AND SLIDE
OFFSHORE...AS SFC HIGH PRESSURE BUILDS OVR RGN UNDER IT...BFR
SLIDING OFFSHORE. ANOTHER FINE SUMMER DAY AS HIGH TEMPS REACH THE
LOW AND MID 80S IN MOST AREAS WITH UPPER 70S IN THE HIR TRRN.
FRI NT AND SAT THE RIDGE AT ALL LVLS SLIDES OFFSHORE AND AN INCR
S-SW FLOW OF INCRG MOISTURE ADVECTION SETS UP ACROSS THE EASTERN
SEABOARD. TD INCREASE BACK INTO THE 60S WITH VRBL TO INCR CLOUDS.
DURING THE DAY SAT MODELS BEGIN TO DIVERGE IN TIMING BOTH THE
APPROACHING CDFNT AND THE THREAT OF TSTMS/SHRA. THE ECMWF/GEM
HOLD THE BULK OF THE PCPN THREAT OFF TILL LATE SAT...THE NAM/GFS
BRING THREAT INTO RGN BY AFTN. PVS FCST...HPC FAVORED THIS SLOWER
TIMING OF PCPN THREAT AND CDFNT AND GIVEN ITS GENERAL PARALLEL
NATURE TO UPR FLOW THAT LOOKS REASONABLE. SO SAT WILL BE VRBL
CLOUDY...WARM AND HUMID WITH INCRG CHC TSTMS.
SAT NT AND SUN MOST OF THE MDL SUITE BRINGS A CDFNT SLOWLY SOUTH
THROUGH THE FCA...BUT THE SCENARIOS BEGIN SPREADING. THE GEM
STALLS IT IN THE MID ATLC WITH SFC LOW IN THE OH VLY RIPPLING E
ALONG IT...AND CLOUDS AND -SHRA PERSISTING INTO MON. THE
ECMWF/GFS MOVES IT ALBEIT SLOWLY THROUGH FCA WITH CLEARING IMPLIED
N OF I90 CORRIDOR SUN NT. ITS SOUTHERN EXTENT WILL BE DETERMINED
BY VERY SUBTLE VARIATIONS IN THE 500HPA FLOW WHICH REMAINS LARGELY
PARALLEL TO THE BAROCLINIC ZONE.
REGARDLESS...AFTER DAYS OF WELL ABV NORMAL TEMPS...TEMPS WILL TURN
WELL BLO NORMAL SUN...UNDER CLOUDS AND COOLER AIR ADVECTING INTO
FCA ASSOC WITH SFC HIGH OVER ONT/QB.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
GENERALLY A ZONAL FLOW OVER N TIER OF USA IS REPLACED BY A
BUILDING 500 HPA RIDGE. THE GFS KEEPS MST OF THE ENERGY IN A
500HPA CUT OFF OVER S MISS VLY...WHILE THE ECMWF BRINGS SOME TO
THE REGION AS A SHORT WV ACROSS FCA TUE.
AT SAME TIME MON SFC FRONT REMAINS STALLED S OF FCA...WITH THREAT
OF SHRA AND CLOUDS ACROSS S TIER. BYND MON MOST OF THE GUID TAKES
CDFNT FAR ENOUGH S AS SFC HIGH PRESSURE BUILDS E ACROSS S ONT/QB
AND N NYS AND NEW ENG TO ALLOW FOR FAIR CONDS WITH A GRADUAL
WARMING TREND TO SET UP. HWVR THIS IS A LOW CONFIDENCE FCA...AS A
HUNDRED MILES ONE WAY OR THE OTHER WILL RESULT IN SIG CHANGES TO
THE EFP. TEMPS WILL BEGIN PD BLOW NORMAL AND END SLIGHTLY ABV
NORMALS.
WILL POP GRIDS WITH HPC WITH ONLY MINOR CHANGES.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...ABUNDANT LOW-LEVEL MOISTURE RESULTED IN WIDESPREAD
IFR/MVFR CIGS ACROSS THE KGFL/KALB/KPSF/KPOU TAF SITES...THESE CIGS
COULD LINGER UNTIL AROUND 14Z AND HAVE INCLUDED TEMPO GROUPS AT ALL
THE TAF SITES FOR IFR CIGS (MVFR AT KPOU) BETWEEN 12Z AND 14Z.
OTHERWISE MAINLY VFR CONDITIONS EXPECTED AT THE TAF SITES THROUGH AT
LEAST MIDNIGHT TONIGHT. THERE WILL BE A COLD FRONT MOVING THROUGH
THE REGION DURING THE AFTERNOON. THIS COLD FRONT WILL PRODUCE
ISOLATED TO SCATTERED TSTMS...WITH THE POTENTIAL TO PRODUCE STRONG
TO POSSIBLE SEVERE WIND GUSTS. HOWEVER...DUE TO THE ISOLATED TO
SCATTERED NATURE OF THE CONVECTION AND DIFFICULTY PINING DOWN THE
TIMING OF POSSIBLE CONVECTION AT THE TAF SITES...HAVE ONLY INCLUDED
VCSH IN THE TAFS AT THIS TIME. AFTER ABOUT 22Z EXPECT MAINLY CLEAR
TO CLEAR SKIES THROUGH AT LEAST MIDNIGHT...THEN HAVE INCLUDED THE
POTENTIAL FOR MVFR/IFR CIGS/VSBYS DUE TO THE POTENTIAL FOR FOG
FORMATION...ESPECIALLY AT THOSE LOCATIONS THAT GET PCPN THIS AFTN.
WINDS WILL BE LIGHT AND VARIABLE OR SOUTH TO SOUTHWEST AT 8 KTS OR
LESS THROUGH 13Z-14Z...THE WINDS SHOULD PICKUP TO 8 TO 12 KTS...
THEN SWITCH TO WESTERLY BETWEEN 18Z AND 20Z WITH GUSTS OF 15 TO 18
KTS AFTER THAT. AFTER 00Z WINDS WILL QUICKLY DIMINISH AND BECOME
LIGHT.
OUTLOOK...
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF SHRA...TSRA.
SATURDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
&&
.FIRE WEATHER...
FOR THE FIRST TIME IN WEEKS MOST OF FCA HAS HAD OVER A QUARTER OF
AN INCH OF RAIN. FIRE WEATHER CONCERNS SHOULD DIMINISH THROUGH
THIS PERIOD.
RH VALUES WILL DROP TO 45 TO 60 PCT THIS AFTERNOON BEFORE RETURNING
TO NEAR 100 PCT TONIGHT. THEY WILL FALL TO 30 TO 45 PCT FRIDAY
AFTERNOON. WINDS WILL BE LIGHT BECOMING SOUTH FRIDAY AFTERNOON
AROUND 10 MPH.
ANOTHER FRONT COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS FOR
LATE SAT INTO SUN.
&&
.HYDROLOGY...
SCATTERED SHOWERS ARE POSSIBLE THIS MORNING WITH GENERALLY DRY
CONDITIONS EXPECTED FROM THIS AFTERNOON INTO SAT MORNING. SHOWERS
AND THUNDERSTORMS WILL RETURN TO THE REGION LATE SAT INTO SUNDAY
AS ANOTHER COLD FRONT DROPS SOUTH THROUGH THE REGION. LOCALLY
HEAVY DOWNPOURS WILL BE POSSIBLE AND MANY AREAS COULD SEE A HALF
AN INCH TO AN INCH OF MUCH NEEDED RAIN.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER/NAS
NEAR TERM...GJM/NAS
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...GJM
FIRE WEATHER...KL/SNYDER/WASULA
HYDROLOGY...KL/SNYDER/WASULA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
919 PM EDT FRI MAY 29 2015
.SYNOPSIS...
HIGH PRESSURE WILL REESTABLISH ITSELF OFF THE EAST COAST TONIGHT
INTO SATURDAY. A COLD FRONT IS FORECAST TO MOVE ACROSS OUR REGION ON
SUNDAY, THEN STALL ACROSS THE AREA MONDAY INTO TUESDAY, AS A WAVE OF
LOW PRESSURE MOVES ALONG IT. HIGH PRESSURE WILL BUILD TO OUR NORTH
EARLY NEXT WEEK, BEFORE MOVING INTO THE AREA WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
NO BIG CHANGES WITH THE ESTF UPDATE. NAM VERIFIED THE BEST WITH
UPSTREAM AND DELMARVA CONVECTION AND CORROBORATES CURRENT NO PCPN
FORECAST FOR TONIGHT. STILL LOOKING OUT FOR THE DEVELOPMENT OF
SOME LOW CLOUDS AND PATCHY FOG OVERNIGHT. NARRE AND HRRR GUIDANCE
SUGGESTING MORE OF A LOW CLOUD IMPACT THAN FOG ON THE MAINLAND, SO
NO BIG CHANGES WERE MADE TO THE EXTENT OF FOG PRESENTLY IN THE
GRIDS. TEMPERATURES ARE RUNNING A BIT WARMER THAN EXPECTED
NORTHWEST AND COOLER THAN EXPECTED SOUTHEAST. WITH LOWER DEW
POINTS IN THE FORMER, THESE DISCREPANCIES SHOULD DAMPEN OUT OVER
THE NEXT COUPLE OF HOURS.
AN AREA OF HIGH PRESSURE REMAINS OFF THE EASTERN SEABOARD, WITH
AN UPPER LEVEL RIDGE ALSO EXTENDING OVER THE EAST COAST STATES AND
OUT OVER THE ATLANTIC WATERS. LIGHT WINDS THROUGH THE COURSE OF
FRIDAY DAY HAVE SHIFTED FROM AN EASTERLY DIRECTION TO MORE OF A
SOUTHEAST FLOW, AND SOME RETURN MOISTURE WITH DEWPOINTS SLOWLY
CREEPING UPWARD HAS BEEN OBSERVED.
OTHERWISE THEN THROUGH THE OVERNIGHT, THE OTHER MAIN ELEMENT TO
WATCH WILL BE THE POSSIBILITY FOR SOME PATCHY FOG OR PERHAPS A FEW
LOWER CLOUDS TO FORM, MAINLY FROM ALONG THE COAST AND INTO EASTERN
PORTIONS OF OUR FORECAST AREA. WHILE CONFIDENCE IS ONLY MODERATE AT
BEST ON THIS OCCURRING AT THIS TIME, WE DID KEEP A MENTION OF PATCHY
FOG IN THE FORECAST FOR THESE AREAS AS LIGHT SOUTHEAST TO SOUTH
WINDS WILL CONTINUE THROUGH THE NIGHT AND DEWPOINTS RISE INTO THE
60S. OVERNIGHT MINIMUM TEMPERATURES WERE A BLEND OF MET/MAV
GUIDANCE, AND WE ANTICIPATE LOWS IN THE 60S ACROSS THE REGION.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
DURING THE DAYTIME SATURDAY, OUR FORECAST AREA WILL BE ON THE
WESTERN PERIPHERY OF LINGERING OFFSHORE HIGH PRESSURE AND AN UPPER
LEVEL RIDGE. IN ADDITION, A COLD FRONT IS EXPECTED TO BE APPROACHING
SLOWLY FROM AROUND THE EASTERN GREAT LAKES, WITH A LEE-SIDE TROUGH
POSSIBLY DEVELOPING TO THE WEST OF OUR REGION AROUND THE
APPALACHIANS. THESE FACTORS, ALONG WITH SOME INCREASING DAYTIME
INSTABILITY, WILL LIKELY BE ENOUGH FOR SOME ISOLATED TO PERHAPS
SCATTERED SHWRS/TSTORMS TO DEVELOP FROM LATE MORNING THROUGH THE
AFTERNOON. OVERALL, WE FOCUSED HIGHEST POPS ACROSS OUR WESTERN
ZONES. MUGGY CONDITIONS WILL BE FELT ACROSS THE AREA, WITH DEWPOINTS
INTO THE 60S. MAXIMUM TEMPERATURES WERE A BLEND OF MET/MAV GUIDANCE
WITH CONTINUITY, AND WE ANTICIPATE HIGHS TO REACH INTO THE 80S FOR
MOST OF THE REGION, EXCEPT SOME COOLER 70S ALONG THE COAST AND INTO
THE POCONOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THE REGION WILL BE UNDER THE INFLUENCE OF A SOUTHWEST FLOW ALOFT AS
A MID-LEVEL TROUGH TRANSITS THE GREAT LAKES AND NORTHEAST CONUS SUN
THRU WED...WHILE AN ATTENDANT COLD FRONT MOVING INTO THE REGION ON
SUN BECOMES QUASI-STATIONARY OVER THE MID ATLANTIC THRU EARLY NEXT
WEEK...AS THE TROUGH GRADUALLY AMPLIFIES CAUSING THE MID-LEVEL FLOW
TO BECOME PARALLEL TO IT. THE FLOW SHOULD BECOME MORE ZONAL WITH
WEAK RIDGING BY WED-THU...WITH FAIR WX EXPECTED TO RETURN. TEMPS...
W/THE EXCEPTION OF MON AND TUE...SHOULD BE NEAR SEASONABLE NORMALS.
THE MAIN CONCERN DURING THE LONG TERM PORTION OF THE FORECAST IS
THE POTENTIAL FOR CONVECTION ON SUN AND HEAVY RAINFALL EARLY NEXT
WEEK. A COLD FRONT WILL APPROACH SUN AFTN...WITH AN ANAFRONT-TYPE
SETUP...AS THE BULK OF THE PRECIP IS EXPECTED TO THE NORTH AND WEST.
ML CAPE VALUES REACH 2-3 KJ...WHILE THE MOST FAVORABLE BULK SHEAR
IS ALONG AND JUST WEST OF THE FRONT. MODEL SOUNDINGS INDICATE AN
ENVIRONMENT MOST FAVORABLE FOR GUSTY WINDS WITH ANY THUNDERSTORMS
THAT OCCUR. HEAVY RAINFALL IS ALSO POSSIBLE...GIVEN PWATS OF 1.5
INCHES /1-2 STD DEV ABOVE NORMAL/ AS WELL AS SLUGGISH STORM MOTION.
THE FRONT STALLS OVER THE MID ATLANTIC REGION LATE SUN/EARLY MON
AND THIS LEADS TO AN OVERRUNNING REGIME...AS LOW PRES DEVELOPS
ALONG IT DURING THE MON-TUE TIME FRAME. THE MAIN UNCERTAINTY HERE
IS WITH REGARD TO THE PLACEMENT OF THE OVERRUNNING...AS THE MODELS
TREND FURTHER NORTH...GIVEN THE TENDENCY TOWARD A MORE AMPLIFIED
TROUGH. THE POTENTIAL EXISTS FOR 1-2 INCHES OF RAINFALL...WHICH
COULD LEAD TO FLOODING PROBLEMS DUE TO DRY ANTECEDENT CONDITIONS
BUT THERE IS A HIGH AMOUNT OF UNCERTAINTY AT THIS TIME.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
00Z TAFS ARE A BIT MORE PESSIMISTIC OVERNIGHT. THERE HAS BEEN
RECENT HOURLY MODELING TRENDS OF A GROWING CONSENSUS OF A
BORDERLINE MVFR/IFR CIG FORMING TOWARD MORNING THRUT OUR REGION
WITH CIGS TENDING TO BE IFR NEAR/AT THE COAST. CONFIDENCE IS
MODERATE INLAND, BUT HIGH AT COASTAL AIRPORTS AND TERMINALS.
REST OF THIS EVENING...VFR NO CIG, MAINLY CIRRUS. LOWEST
CONFIDENCE KACY AS THEY SHOULD BE FIRST TO OBSERVE THE STRATUS.
SOUTH TO SOUTHEAST WINDS BECOMING LIGHTER AND AVERAGING LESS THAN
10 KNOTS.
OVERNIGHT...LOW MVFR TO IFR CIG FORMING AND SPREADING THROUGHOUT
MOST OF THE REGION. CLOSER TO MIDNIGHT AT THE COAST AND LATER
AT NIGHT INLAND. VSBYS BECOMING MVFR, IFR AT KMIV. IF LOW
CLOUDS DO NOT FORM, GREATER CHANCES FOR IFR VSBYS AT MORE RURAL
AIRPORTS. LIGHT SOUTH WINDS.
SATURDAY MORNING...BECOMING VFR WITH NO CIG DVLPG BETWEEN 13Z AND
15Z. VSBY LIKELY IMPROVING FIRST TO VFR. SOUTH WINDS INCREASING TO
AROUND 10 KNOTS.
SATURDAY AFTERNOON...VFR WITH A GUSTIER SOUTH WIND. WIND GUSTS
IN FINAL FORECAST GROUP MORE LIKELY TO OCCUR IN AFTERNOON.
SCATTERED SHWRS AND TSTMS WILL DEVELOP, BUT MOST LIKELY TO
OCCUR NORTH AND WEST OF TERMINALS. CONFIDENCE TOO LOW TO INCLUDE.
LOWEST CONFIDENCE OF EXCLUSION AT KABE.
OUTLOOK...
SAT NIGHT...MVFR POSSIBLE IN LOW CLOUDS AND FOG NEAR THE
COAST...ESP ACY AND MIV.
SUN...MVFR LIKELY IN SHRA AND TSRA DURING THE AFTN AND EVE HOURS...
OTHERWISE VFR.
SUN NIGHT THRU MON NIGHT...MVFR IN SHRA/TSRA...LOW CLOUDS...AND FOG.
TUE...MVFR IN SHRA/TSRA...WITH GRADUAL IMPROVEMENT TO VFR
POSSIBLE.
&&
.MARINE...
SUB-ADVISORY CONDITIONS WILL CONTINUE FOR THE COASTAL WATERS AND FOR
DELAWARE BAY THROUGH TONIGHT, WITH GENERALLY LIGHT SOUTHEAST WINDS
BECOMING MORE SOUTHERLY AS THE NIGHT PROGRESSES. SOME FOG MAY
DEVELOP OVER THE WATERS DURING THE OVERNIGHT AND ADVECT TO THE
COAST, CAUSING LOCALLY REDUCED VISIBILITIES.
REDUCED VISIBILITIES IN FOG IS POSSIBLE EARLY SATURDAY FOR THE
WATERS, OTHERWISE SUB-SCA CONDITIONS ARE EXPECTED THROUGH THE
MORNING. MARGINAL SCA CONDITIONS MAY BE REACHED SATURDAY AFTERNOON
AND EVENING, WITH WIND GUSTS APPROACHING 25 KNOTS, ESPECIALLY FOR
THE NORTHERN COASTAL WATERS. HOWEVER, CONFIDENCE WAS NOT HIGH ENOUGH
AT THIS TIME TO ISSUE A SMALL CRAFT ADVISORY. WE WILL ALLOW THE NEXT
SHIFT TO RE-EVALUATE INCOMING DATA.
OUTLOOK...
SAT NIGHT THRU TUE...SCA CONDITIONS POSSIBLE THRU THE ENTIRE
PERIOD...AS A COLD FRONT STALLS OVER THE WATERS ON SUNDAY AND LOW
PRESSURE DEVELOPS ALONG IT EARLY NEXT WEEK. AT THIS TIME...HIGHEST
CONFIDENCE IN SEAS MEETING SCA THRESHOLDS.
&&
.RIP CURRENTS...
NEW WEBLINK, WORKS BEST ON FIREFOX. DISPLAYS THE FCST GRAPHIC ETC.
WWW.WEATHER.GOV/PHI/SURFRIP4
THE INITIAL RIP CURRENT RISK FOR THE NEW JERSEY COAST ON SATURDAY
IS MODERATE WHILE FOR THE DELAWARE COAST THE INITIAL RIP CURRENT
RISK IS LOW. THIS FOLLOWS OUR LONG TIME IN HOUSE PROCEDURE. THE
GRIDDED PROCEDURE SPLITS NEW JERSEY IN HALF WITH THE MODERATE RISK
IN OCEAN AND MONMOUTH COUNTIES. IN GENERAL LOOKS LIKE PREDICTED
WINDS ARE STRONGER PROGRESSIVELY FARTHER NORTH ALONG ON THE
WATERS. THIS WILL BE TRACKED AND REACCESSED OVERNIGHT.
&&
.CLIMATE...
MAY 2015...A TOP 5 WARMEST ON RECORD FOR LARGE PORTIONS OF OUR AREA.
ALL OVERNIGHT AND FORECAST INFORMATION CHECKED THROUGH 830 AM
TODAY - FRIDAY MAY 29.
CONSERVATIVE VALUES LISTED BELOW FROM OUR 5 AM SFT AND COOLING THE
NEAR MIDNIGHT SUNDAY NIGHT MAY 31 LOW TEMP DUE TO NLY FLOW CAA SUNDAY
EVENING.
ALLENTOWN WILL PROBABLY AVERAGE VERY CLOSE TO 65.9 OR 6 DEGREES
ABOVE NORMAL. POR BACK TO 1922. AT LEAST 5TH WARMEST ON RECORD.
1991 67.2
2012 66.1
1944 66.0
2004 65.9
PHILADELPHIA WILL PROBABLY AVERAGE CLOSE TO 69.7 DEGREES OR 5.8
DEGREES ABOVE NORMAL. SECOND WARMEST ON RECORD.
1991 70.8
NUMBER 3 WOULD BE 69.2 IN 2004.
ATLANTIC CITY MAY 2015 65.9 OR 66.0 OR 4.8 TO 4.9 ABOVE NORMAL
AND PROBABLE #2 OR #3 POR BACK TO 1874
2004 66.9
1991 66.0
2015
WILMINGTON DE SOLID POR BACK TO 1916 LOCKED INTO #4 WARMEST
1896 70.1
1991 69.1
2004 68.2
2015 AROUND 68.0
NO AVAILABLE MONTHLY HISTORICAL DATA FOR KMPO KGED KTTN AND KRDG.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANCK
NEAR TERM...GIGI/KLINE
SHORT TERM...KLINE
LONG TERM...FRANCK
AVIATION...FRANCK/GIGI
MARINE...FRANCK/KLINE
RIP CURRENTS...
CLIMATE...
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
233 PM EDT THU MAY 28 2015
.SHORT TERM (NOW THROUGH TOMORROW)...WEAK MID AND UPPER LEVEL
RIDGING HAS ESTABLISHED OVER THE REGION TODAY WITH SIGNIFICANTLY
DRIER AIR IN PLACE THROUGH THE MID LEVELS. AT THE SURFACE A
COUPLE PERTURBATION ALONG THE SOUTHERN FRINGE OF THE SURFACE
RIDGE CENTERED NORTH OF THE AREA HAS HELPED TIGHTEN THE PRESSURE
GRADIENT OVER THE CENTRAL PENINSULA. A DECENT PUSH FROM THE
EASTERLY WINDS IS HELPING TO OVERCOME THE DIURNAL SHIFT IN WINDS.
WITH THE LACK OF MOISTURE AND SEA BREEZE FORCING RAIN CHANCES WILL
REMAIN MINIMAL TODAY AND TONIGHT ACROSS THE REGION. HRRR REMAINS
THE OUTLIER IN TERMS OF SEA BREEZE DEVELOPMENT TODAY SO HAVE SIDED
WITH THE WRF AND HI RES NMM AND KEPT THE SEA BREEZE WIND SHIFT OUT
OF THE FORECAST. HOWEVER MAY SEE WINDS BRIEFLY SHIFT TOWARDS THE
NNE RIGHT ALONG THE COASTLINE.
FOR TOMORROW... DRY AIR MASS WILL BEGIN TO MODERATE OVER THE
MORNING HOURS AS MOISTURES SURGES ACROSS THE PENINSULA FROM THE
ATLANTIC. HIGHER MOISTURE CONTENT WILL FAVOR THE SOUTHERN HALF OF
THE CWA SO HAVE INCREASED POPS FOR THE SOUTH ZONES DURING THE
LATE AFTERNOON. SEA BREEZE TOMORROW WILL AGAIN HAVE TROUBLE
SHIFTING INLAND AND IF IT IS ABLE TO DEVELOP IT WILL BE PINNED
ALONG THE COASTLINE. EXPECT SOME FORCING ALONG THE COAST SO SOME
THUNDERSTORMS WILL HAVE A BETTER CHANCE TO DEVELOP FOR AREAS WEST
OF I 75. TEMPERATURES TOMORROW AFTERNOON WILL BE A DEGREE OR TWO
COOLER GIVEN INCREASED CLOUD COVER AND INCREASED RAIN POTENTIAL.
.MID/LONG TERM (TOMORROW NIGHT THROUGH THURSDAY)... UPPER AND
SURFACE RIDGING WILL REMAIN IN PLACE ALONG THE EASTERN SEA BOARD
THROUGH THE UPCOMING WEEKEND AS A PERSISTENT UPPER TROUGH OVER THE
CENTRAL U.S SHIFTS SLOWLY EAST IN THE MISSISSIPPI VALLEY. AN EAST
TO SOUTHEAST WIND FLOW AROUND THE SURFACE HIGH WILL ALLOW FOR A
SLOW INCREASE IN MOISTURE ACROSS THE FORECAST AREA SATURDAY AND
SUNDAY. THIS INCREASE IN MOISTURE COMBINED WITH DAYTIME HEATING
WILL LEAD TO INCREASING CHANCES FOR SCATTERED DIURNAL SEA BREEZE
DRIVEN SHOWERS AND STORMS EACH DAY WITH HIGHEST RAIN CHANCES
SETTING UP ALONG AND JUST EAST OF THE I-75 CORRIDOR WHERE THE EAST
AND WEST COAST SEA BREEZE MERGER OCCURS DURING THE AFTERNOON AND
EARLY EVENING HOURS.
DURING THE LATTER PART OF THE WEEKEND AND INTO EARLY NEXT WEEK
MODELS SHOW A CLOSED UPPER LEVEL LOW EVOLVING OVER THE LOWER MS
VALLEY. THE GFS AND ECMWF DIFFER SOME WITH THE HANDLING OF THE
FEATURE BUT IN GENERAL BOTH MEANDER THIS LOW OVER THE LOWER MS
VALLEY OR JUST OFFSHORE THE NORTH CENTRAL GULF COAST THROUGH THE
END OF THE FORECAST PERIOD...WHILE A WEAK AREA OF SURFACE LOW
PRESSURE TRIES TO DEVELOP IN THE VICINITY OF FLORIDA. DESPITE THE
MODEL DIFFERENCES DEEP TROPICAL MOISTURE (PW`S INCREASING TO 2+
INCHES) BEING DRAWN NORTH INTO THE FORECAST AREA ON A DEEP LAYERED
SOUTHEAST TO SOUTHERLY WIND FLOW ON THE EASTERN SIDE OF THE
CLOSED LOW WILL KEEP RAIN CHANCES ELEVATED ACROSS THE REGION
WITH THE POTENTIAL FOR SOME LOCALLY HEAVY RAINFALL FROM MID
WEEK ON.
FOR NOW WILL DEPICT POPS IN THE 50 TO 60 PERCENT RANGE (THOUGH
THESE VALUES MAY HAVE TO BE INCREASED IN LATER FORECASTS) AND
WILL WAIT TO SEE IF BETTER MODEL CONTINUITY DEVELOPS OVER THE
COMING DAYS. TEMPERATURES WILL RUN A FEW DEGREES ABOVE NORMAL
THROUGH EARLY NEXT WEEK...THEN NEAR NORMAL FROM MID WEEK ON AS
RAIN CHANCES INCREASE ACROSS THE REGION.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH TOMORROW. SOUTHERN
TAF SITES EXPECT VSCH OR VCTS BY THE MID TO LATE AFTERNOON.
&&
.MARINE...SURFACE PRESSURE GRADIENT HAS TIGHTENED SLIGHTLY ACROSS
THE EASTERN GULF HELPING TO MAINTAIN A GENTLE TO MODERATE BREEZE
ACROSS THE GULF WATERS. WITH THE EASTERLY FLOW ESTABLISHED EXPECT AN
NOCTURNAL EASTERLY SURGE AGAIN TONIGHT WITH A MODERATE TO FRESH
BREEZE POSSIBLE THROUGH SUNRISE. SOME EXCESS MOISTURE STREAMING
ACROSS THE STATE TOMORROW WILL INCREASE THE POTENTIAL FOR SOME
THUNDERSTORM DEVELOPMENT ALONG THE COAST DURING THE LATE AFTERNOON
AND PUSHING OFF SHORE DURING THE EVENING HOURS.
&&
.FIRE WEATHER...A DRIER AIR MASS REMAINS IN PLACE OVER THE REGION
WITH EAST WINDS BREEZY AT TIMES. HOWEVER...WINDS AND RH WILL
REMAIN OUTSIDE OF RED FLAG CRITERIA. EXPECTING THE DRY AIR TO
MODERATE BY TOMORROW MORNING WITH AN INCREASED POTENTIAL FOR
SHOWERS AND THUNDERSTORMS BY THE AFTERNOON HOURS... MAINLY SOUTH
OF TAMPA BAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 70 88 73 90 / 0 20 20 40
FMY 69 91 71 91 / 0 40 10 40
GIF 68 89 71 91 / 0 20 0 40
SRQ 69 88 72 89 / 10 20 30 40
BKV 65 89 68 91 / 0 20 10 40
SPG 73 87 75 89 / 10 20 30 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...20/BARRON
LONG TERM/DECISION SUPPORT...57/MCMICHAEL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
523 PM CDT THU MAY 28 2015
.SHORT TERM...
225 PM CDT
THROUGH TONIGHT...
THE FORECAST AREA FINDS ITSELF BETWEEN TWO STATIONARY FRONTS
THIS AFTERNOON WITH A WEAK RIDGE OF HIGH PRESSURE SANDWICHED IN
BETWEEN DIRECTLY OVER THE AREA. THIS RIDGE HAS ALLOWED A LAKE
BREEZE WITH LAKESIDE COOLING AT THE CHICAGO SHORE ABOUT 14
DEGREES COOLER THAN INLAND AT ORD/MDW AS OF 200 PM. THE FRONT OF
INTEREST FOR OUR AREA TONIGHT WILL BE THE ONE TO THE SOUTH WHICH
WILL LIFT NORTH AS A WARM FRONT...BRINGING A RETURN TO MUGGY AIR
BY DAYBREAK...AS WELL AS KEEP NIGHTTIME TEMPERATURES MILD...EVEN
INCREASING THEM LATE TONIGHT ALONG THE LAKE SHORE AREAS.
MULTIPLE MID-LEVEL DISTURBANCES...SOME LIKELY CONVECTIVELY
ENHANCED...ARE NOTED ON WATER VAPOR AND RADAR MOSAIC IMAGERY ACROSS
THE CENTRAL PLAINS THIS AFTERNOON. ONE OF THESE JUST NORTH OF KANSAS
CITY AS OF 200 PM IS WELL ANALYZED BY THE LATEST RAP AND THIS IS
EXPECTED TO PROPAGATE INTO WISCONSIN OVERNIGHT...WITH ONE OR TWO
WEAKER IMPULSES TO ITS SOUTH APPROACHING THE AREA. WITH A 25-30 KT
LOW-LEVEL JET AHEAD OF THESE AND INCREASING MOISTURE AT THAT
HEIGHT...THERE WILL LIKELY BE SCATTERED SHOWERS OR STORMS FROM
SOUTHWEST WISCONSIN INTO NORTHWEST AND POSSIBLY NORTH CENTRAL
ILLINOIS OVERNIGHT.
MTF
&&
.LONG TERM...
314 PM CDT
FRIDAY THROUGH THURSDAY...
MAIN FORECAST CONCERNS/CHALLENGES DURING THE PERIOD ARE WITH
SHOWER/THUNDERSTORM CHANCES FRIDAY INTO SATURDAY...AND THEN WITH
MUCH COOLER AIR TO PUSH ACROSS THE AREA SATURDAY.
SOME UNCERTAINTY AS TO HOW THE PERIOD WILL BEGIN...DUE TO HOW
PRECIP DEVELOPMENT WILL EVOLVE LATE TONIGHT INTO FRIDAY MORNING.
THE CURRENT UPSTREAM MID LEVEL TROUGH OVER THE CENTRAL PLAINS WILL
CONTINUE MOVING NORTHEAST THROUGH THE CWA FRIDAY MORNING...WITH
LINGERING PRECIP FROM THE OVERNIGHT STILL LIKELY TO AFFECT
PRIMARILY THE WESTERN HALF OF THE CWA IN NORTH CENTRAL ILLINOIS.
LIKELY SCENARIO WILL BE FOR THIS DEVELOPMENT TO CONTINUE EAST
THROUGH THE MORNING. CONFIDENCE WITH OVERALL COVERAGE DURING
FRIDAY MORNING IS LOW...AND HAVE THUS CAPPED POPS AT LIKELYS.
MORNING PRECIP AND EVEN CLOUD COVER SHOULD EXIT THROUGH LATE
MORNING AND MIDDAY...WITH SKIES BECOMING MORE PARTLY CLOUDY/PARTLY
SUNNY. THIS WILL HELP WITH EARLY DESTABILIZATION WITH LITTLE TO NO
INHIBITION AND WITH MID LEVEL ENERGY RETURNING DURING THIS
TIME...THINK DEVELOPMENT WILL ONCE AGAIN BE POSSIBLE IN THE
AFTERNOON. WITH A LACK OF GOOD FOCUS AT THE SURFACE...THINK BEST
DEVELOPMENT WILL STILL BE ACROSS NORTH CENTRAL ILLINOIS WHERE
BETTER LARGE SCALE ASCENT WILL RESIDE. WEAK MID/UPPER LEVEL FLOW
WILL BE A LIMITING FACTOR WITH HOW ORGANIZED ANY STORM WILL BE AND
ALTHOUGH I DONT THINK THERE WILL BE ANY WIDESPREAD SEVERE
THREAT...AN ISOLATED STRONG TO SEVERE STORM WILL STILL BE POSSIBLE
WITH STRONG WINDS AND HEAVY RAINFALL THE MAIN HAZARDS DUE TO
INCREASING INSTABILITY AND MOISTURE. 80 DEGREE WEATHER WILL BE
LIKELY FRIDAY...BUT WITH TEMPS LIKELY BEING LIMITED IN ANY AREA
THAT OBSERVES MORE PRECIP/CLOUD COVER.
STILL THINK THAT THE BEST CHANCES FOR WIDESPREAD
SHOWER/THUNDERSTORM DEVELOPMENT WILL BE FRIDAY NIGHT INTO SATURDAY
MORNING. HOWEVER...GUIDANCE IS VARYING WITH REGARDS TO HOW THE
NIGHT WILL EVOLVE. THIS IS LIKELY DUE TO LARGER TROUGH OVER
SOUTHERN CANADA AND NORTHERN PLAINS MOVING EAST/SOUTHEAST...WHILE
A SEPARATE TROUGH AND SEVERAL IMPULSES WORKS EAST THROUGH THE
PLAINS. NONETHELESS...BEST LOW/MID LEVEL COVERAGE WILL PUSH
THROUGH THE CWA DURING THIS TIME WHILE LARGE SCALE FORCING ALSO
INCREASES. SO DO THINK PRECIP WILL PUSH THROUGH THE CWA...BUT WITH
COVERAGE AND DURATION POSSIBLY LOWER IN SOME LOCATIONS. THUNDER
SHOULD BE DECREASING IN COVERAGE THROUGHOUT THE NIGHT AND
ESPECIALLY INTO SATURDAY MORNING AS THE INSTABILITY AXIS SHIFTS
SOUTH...WITH HEAVY RAINFALL THE MAIN HAZARD DURING THIS TIME. ANY
LINGERING PRECIP WILL CONTINUE SOUTH OF THE CWA THROUGH MIDDAY
SATURDAY AS SURFACE TROUGH AND FRONT PUSH THROUGH THE REGION.
CLOUD COVER WILL LIKELY LINGER THROUGH MUCH OF SATURDAY WHILE
WINDS/GUSTS INCREASE THROUGHOUT THE DAY. HIGH TEMPS WILL LIKELY
OCCUR EARLY SATURDAY MORNING WITH TEMPS FALLING THROUGH THE
DAY...WITH 40 DEGREE WEATHER LIKELY FOR MOST LOCATIONS IN FAR
NORTHEAST ILLINOIS AND NORTHWEST INDIANA FOR MUCH OF THE DAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* -SHRA AND TSRA TIMING ON FRIDAY.
KJB
//DISCUSSION...UPDATED 18Z...
WEAK HIGH PRESSURE DRIFTING EASTWARD HAS INFLUENCED A SOUTHEAST
FLOW. LAKE MICHIGAN HAS TAKEN HOLD OF THE WINDS AT ORD/MDW/GYY
WITH WINDS NOW EASTERLY OVER 10KT. OBSERVATIONS HAVE SHOWN SOME
GUSTS TO 15KT AS WELL FROM THE EAST TO SOUTHEAST. AFTER 01Z...THE
WINDS WILL RELAX SOME TO BECOME LESS THAN 10KT. OVERALL FLOW WILL
ALSO THEN BECOME SOUTHERLY AS LOW PRESSURE APPROACHES FROM THE
WEST EARLY FRIDAY. SOME RAIN SHOWERS ARE EXPECTED AND A CANOPY OF
BKN100 CEILINGS ARE EXPECTED AT MOST SITES.
TIMED OUT BEST CHANCE FOR TSRA BASED ON INSTABILITY INCREASING IN
THE 15-19Z TIMEFRAME...ALONG WITH THE POTENTIAL FOR A WAVE TO
HELP LIFT THINGS OFF DURING THAT TIME. LOOKING FORWARD...A BETTER
CHANCE FOR WIDESPREAD PRECIPITATION EXISTS EARLY SATURDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* LOW-MEDIUM WITH SHRA AND TSRA TIMING ON FRIDAY.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...PERIODIC SHRA/TSRA. MVFR POSSIBLE. SOUTHWEST WINDS.
SATURDAY....CHANCE SHRA EARLY. MVFR POSSIBLE. STRONG NORTH-
NORTHEAST WINDS.
SUNDAY...VFR/WX NIL. NORTHEAST WINDS.
MONDAY...VFR/WX NIL. EAST WINDS.
TUESDAY...VFR/WX NIL. SOUTHEAST WINDS.
WEDNESDAY...SLIGHT CHANCE SHRA. SOUTH WINDS.
KREIN
&&
.MARINE...
225 PM CDT
A SURFACE COLD FRONT DRAPED FROM WEST-TO-EAST ACROSS THE NORTHERN
PART OF THE LAKE WILL SHIFT NORTHWARD THIS EVENING. THIS WILL BE A
SOURCE FOR FOG ALONG IT AND THIS HAS BEEN SEEN ON VISIBLE SATELLITE
AT TIMES DURING THURSDAY. EVEN HIGHER MOISTURE WILL MOVE NORTHWARD
ACROSS THE LAKE ON FRIDAY ALLOWING FOR THE POSSIBILITY OF FOG AS
WELL...ESPECIALLY WHERE SHOWERS ARE NOT PREVALENT.
LOW PRESSURE WILL MOVE EAST INTO QUEBEC ON FRIDAY NIGHT AND STEER
A COLD FRONT SOUTHEASTWARD ACROSS THE LAKE. AS HIGH PRESSURE
BUILDS SOUTHWARD FROM ONTARIO ON SATURDAY...IT WILL DRIVE A STRONG
NORTHERLY WINDS FOR LATE MAY ACROSS THE CENTRAL AND SOUTHERN PARTS
OF THE LAKE. THIS WILL RESULT IN SMALL CRAFT ADVISORY CONDITIONS
FOR THE ILLINOIS AND INDIANA NEARSHORE AREAS SATURDAY AFTERNOON
AND NIGHT WITH LINGERING HIGH WAVES ON SUNDAY.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
317 PM CDT THU MAY 28 2015
.SHORT TERM...
225 PM CDT
THROUGH TONIGHT...
THE FORECAST AREA FINDS ITSELF BETWEEN TWO STATIONARY FRONTS
THIS AFTERNOON WITH A WEAK RIDGE OF HIGH PRESSURE SANDWICHED IN
BETWEEN DIRECTLY OVER THE AREA. THIS RIDGE HAS ALLOWED A LAKE
BREEZE WITH LAKESIDE COOLING AT THE CHICAGO SHORE ABOUT 14
DEGREES COOLER THAN INLAND AT ORD/MDW AS OF 200 PM. THE FRONT OF
INTEREST FOR OUR AREA TONIGHT WILL BE THE ONE TO THE SOUTH WHICH
WILL LIFT NORTH AS A WARM FRONT...BRINGING A RETURN TO MUGGY AIR
BY DAYBREAK...AS WELL AS KEEP NIGHTTIME TEMPERATURES MILD...EVEN
INCREASING THEM LATE TONIGHT ALONG THE LAKE SHORE AREAS.
MULTIPLE MID-LEVEL DISTURBANCES...SOME LIKELY CONVECTIVELY
ENHANCED...ARE NOTED ON WATER VAPOR AND RADAR MOSAIC IMAGERY ACROSS
THE CENTRAL PLAINS THIS AFTERNOON. ONE OF THESE JUST NORTH OF KANSAS
CITY AS OF 200 PM IS WELL ANALYZED BY THE LATEST RAP AND THIS IS
EXPECTED TO PROPAGATE INTO WISCONSIN OVERNIGHT...WITH ONE OR TWO
WEAKER IMPULSES TO ITS SOUTH APPROACHING THE AREA. WITH A 25-30 KT
LOW-LEVEL JET AHEAD OF THESE AND INCREASING MOISTURE AT THAT
HEIGHT...THERE WILL LIKELY BE SCATTERED SHOWERS OR STORMS FROM
SOUTHWEST WISCONSIN INTO NORTHWEST AND POSSIBLY NORTH CENTRAL
ILLINOIS OVERNIGHT.
MTF
&&
.LONG TERM...
314 PM CDT
FRIDAY THROUGH THURSDAY...
MAIN FORECAST CONCERNS/CHALLENGES DURING THE PERIOD ARE WITH
SHOWER/THUNDERSTORM CHANCES FRIDAY INTO SATURDAY...AND THEN WITH
MUCH COOLER AIR TO PUSH ACROSS THE AREA SATURDAY.
SOME UNCERTAINTY AS TO HOW THE PERIOD WILL BEGIN...DUE TO HOW
PRECIP DEVELOPMENT WILL EVOLVE LATE TONIGHT INTO FRIDAY MORNING.
THE CURRENT UPSTREAM MID LEVEL TROUGH OVER THE CENTRAL PLAINS WILL
CONTINUE MOVING NORTHEAST THROUGH THE CWA FRIDAY MORNING...WITH
LINGERING PRECIP FROM THE OVERNIGHT STILL LIKELY TO AFFECT
PRIMARILY THE WESTERN HALF OF THE CWA IN NORTH CENTRAL ILLINOIS.
LIKELY SCENARIO WILL BE FOR THIS DEVELOPMENT TO CONTINUE EAST
THROUGH THE MORNING. CONFIDENCE WITH OVERALL COVERAGE DURING
FRIDAY MORNING IS LOW...AND HAVE THUS CAPPED POPS AT LIKELYS.
MORNING PRECIP AND EVEN CLOUD COVER SHOULD EXIT THROUGH LATE
MORNING AND MIDDAY...WITH SKIES BECOMING MORE PARTLY CLOUDY/PARTLY
SUNNY. THIS WILL HELP WITH EARLY DESTABILIZATION WITH LITTLE TO NO
INHIBITION AND WITH MID LEVEL ENERGY RETURNING DURING THIS
TIME...THINK DEVELOPMENT WILL ONCE AGAIN BE POSSIBLE IN THE
AFTERNOON. WITH A LACK OF GOOD FOCUS AT THE SURFACE...THINK BEST
DEVELOPMENT WILL STILL BE ACROSS NORTH CENTRAL ILLINOIS WHERE
BETTER LARGE SCALE ASCENT WILL RESIDE. WEAK MID/UPPER LEVEL FLOW
WILL BE A LIMITING FACTOR WITH HOW ORGANIZED ANY STORM WILL BE AND
ALTHOUGH I DONT THINK THERE WILL BE ANY WIDESPREAD SEVERE
THREAT...AN ISOLATED STRONG TO SEVERE STORM WILL STILL BE POSSIBLE
WITH STRONG WINDS AND HEAVY RAINFALL THE MAIN HAZARDS DUE TO
INCREASING INSTABILITY AND MOISTURE. 80 DEGREE WEATHER WILL BE
LIKELY FRIDAY...BUT WITH TEMPS LIKELY BEING LIMITED IN ANY AREA
THAT OBSERVES MORE PRECIP/CLOUD COVER.
STILL THINK THAT THE BEST CHANCES FOR WIDESPREAD
SHOWER/THUNDERSTORM DEVELOPMENT WILL BE FRIDAY NIGHT INTO SATURDAY
MORNING. HOWEVER...GUIDANCE IS VARYING WITH REGARDS TO HOW THE
NIGHT WILL EVOLVE. THIS IS LIKELY DUE TO LARGER TROUGH OVER
SOUTHERN CANADA AND NORTHERN PLAINS MOVING EAST/SOUTHEAST...WHILE
A SEPARATE TROUGH AND SEVERAL IMPULSES WORKS EAST THROUGH THE
PLAINS. NONETHELESS...BEST LOW/MID LEVEL COVERAGE WILL PUSH
THROUGH THE CWA DURING THIS TIME WHILE LARGE SCALE FORCING ALSO
INCREASES. SO DO THINK PRECIP WILL PUSH THROUGH THE CWA...BUT WITH
COVERAGE AND DURATION POSSIBLY LOWER IN SOME LOCATIONS. THUNDER
SHOULD BE DECREASING IN COVERAGE THROUGHOUT THE NIGHT AND
ESPECIALLY INTO SATURDAY MORNING AS THE INSTABILITY AXIS SHIFTS
SOUTH...WITH HEAVY RAINFALL THE MAIN HAZARD DURING THIS TIME. ANY
LINGERING PRECIP WILL CONTINUE SOUTH OF THE CWA THROUGH MIDDAY
SATURDAY AS SURFACE TROUGH AND FRONT PUSH THROUGH THE REGION.
CLOUD COVER WILL LIKELY LINGER THROUGH MUCH OF SATURDAY WHILE
WINDS/GUSTS INCREASE THROUGHOUT THE DAY. HIGH TEMPS WILL LIKELY
OCCUR EARLY SATURDAY MORNING WITH TEMPS FALLING THROUGH THE
DAY...WITH 40 DEGREE WEATHER LIKELY FOR MOST LOCATIONS IN FAR
NORTHEAST ILLINOIS AND NORTHWEST INDIANA FOR MUCH OF THE DAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE WINDS VARYING FROM 080-120 AT 8-12KT GUSTING NEAR
18KT THIS AFTERNOON
* -SHRA BECOMING TSRA FRIDAY AFTERNOON
MM
//DISCUSSION...UPDATED 18Z...
WEAK HIGH PRESSURE DRIFTING EASTWARD HAS INFLUENCED A SOUTHEAST
FLOW. LAKE MICHIGAN HAS TAKEN HOLD OF THE WINDS AT ORD/MDW/GYY
WITH WINDS NOW EASTERLY OVER 10KT. OBSERVATIONS HAVE SHOWN SOME
GUSTS TO 15KT AS WELL FROM THE EAST TO SOUTHEAST. AFTER 01Z...THE
WINDS WILL RELAX SOME TO BECOME LESS THAN 10KT. OVERALL FLOW WILL
ALSO THEN BECOME SOUTHERLY AS LOW PRESSURE APPROACHES FROM THE
WEST EARLY FRIDAY. SOME RAIN SHOWERS ARE EXPECTED AND A CANOPY OF
BKN100 CEILINGS ARE EXPECTED AT MOST SITES.
TIMED OUT BEST CHANCE FOR TSRA BASED ON INSTABILITY INCREASING IN
THE 15-19Z TIMEFRAME...ALONG WITH THE POTENTIAL FOR A WAVE TO
HELP LIFT THINGS OFF DURING THAT TIME. LOOKING FORWARD...A BETTER
CHANCE FOR WIDESPREAD PRECIPITATION EXISTS EARLY SATURDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN EAST WINDS THROUGH 01Z WITH MEDIUM
CONFIDENCE IN WIND SPEEDS.
* MEDIUM CONFIDENCE IN SHRA AND TSRA OCCURRING FRIDAY...WITH LOW
CONFIDENCE ON TIMING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...PERIODIC SHRA/TSRA. MVFR POSSIBLE. SOUTHWEST WINDS.
SATURDAY....CHANCE SHRA EARLY. MVFR POSSIBLE. STRONG NORTH-
NORTHEAST WINDS.
SUNDAY...VFR/WX NIL. NORTHEAST WINDS.
MONDAY...VFR/WX NIL. EAST WINDS.
TUESDAY...VFR/WX NIL. SOUTHEAST WINDS.
WEDNESDAY...SLIGHT CHANCE SHRA. SOUTH WINDS.
KREIN
&&
.MARINE...
225 PM CDT
A SURFACE COLD FRONT DRAPED FROM WEST-TO-EAST ACROSS THE NORTHERN
PART OF THE LAKE WILL SHIFT NORTHWARD THIS EVENING. THIS WILL BE A
SOURCE FOR FOG ALONG IT AND THIS HAS BEEN SEEN ON VISIBLE SATELLITE
AT TIMES DURING THURSDAY. EVEN HIGHER MOISTURE WILL MOVE NORTHWARD
ACROSS THE LAKE ON FRIDAY ALLOWING FOR THE POSSIBILITY OF FOG AS
WELL...ESPECIALLY WHERE SHOWERS ARE NOT PREVALENT.
LOW PRESSURE WILL MOVE EAST INTO QUEBEC ON FRIDAY NIGHT AND STEER
A COLD FRONT SOUTHEASTWARD ACROSS THE LAKE. AS HIGH PRESSURE
BUILDS SOUTHWARD FROM ONTARIO ON SATURDAY...IT WILL DRIVE A STRONG
NORTHERLY WINDS FOR LATE MAY ACROSS THE CENTRAL AND SOUTHERN PARTS
OF THE LAKE. THIS WILL RESULT IN SMALL CRAFT ADVISORY CONDITIONS
FOR THE ILLINOIS AND INDIANA NEARSHORE AREAS SATURDAY AFTERNOON
AND NIGHT WITH LINGERING HIGH WAVES ON SUNDAY.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
241 PM CDT THU MAY 28 2015
.SHORT TERM...
225 PM CDT
THROUGH TONIGHT...
THE FORECAST AREA FINDS ITSELF BETWEEN TWO STATIONARY FRONTS
THIS AFTERNOON WITH A WEAK RIDGE OF HIGH PRESSURE SANDWICHED IN
BETWEEN DIRECTLY OVER THE AREA. THIS RIDGE HAS ALLOWED A LAKE
BREEZE WITH LAKESIDE COOLING AT THE CHICAGO SHORE ABOUT 14
DEGREES COOLER THAN INLAND AT ORD/MDW AS OF 200 PM. THE FRONT OF
INTEREST FOR OUR AREA TONIGHT WILL BE THE ONE TO THE SOUTH WHICH
WILL LIFT NORTH AS A WARM FRONT...BRINGING A RETURN TO MUGGY AIR
BY DAYBREAK...AS WELL AS KEEP NIGHTTIME TEMPERATURES MILD...EVEN
INCREASING THEM LATE TONIGHT ALONG THE LAKE SHORE AREAS.
MULTIPLE MID-LEVEL DISTURBANCES...SOME LIKELY CONVECTIVELY
ENHANCED...ARE NOTED ON WATER VAPOR AND RADAR MOSAIC IMAGERY ACROSS
THE CENTRAL PLAINS THIS AFTERNOON. ONE OF THESE JUST NORTH OF KANSAS
CITY AS OF 200 PM IS WELL ANALYZED BY THE LATEST RAP AND THIS IS
EXPECTED TO PROPAGATE INTO WISCONSIN OVERNIGHT...WITH ONE OR TWO
WEAKER IMPULSES TO ITS SOUTH APPROACHING THE AREA. WITH A 25-30 KT
LOW-LEVEL JET AHEAD OF THESE AND INCREASING MOISTURE AT THAT
HEIGHT...THERE WILL LIKELY BE SCATTERED SHOWERS OR STORMS FROM
SOUTHWEST WISCONSIN INTO NORTHWEST AND POSSIBLY NORTH CENTRAL
ILLINOIS OVERNIGHT.
MTF
&&
.LONG TERM...
TO BE ISSUED SHORTLY.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE WINDS VARYING FROM 080-120 AT 8-12KT GUSTING NEAR
18KT THIS AFTERNOON
* -SHRA BECOMING TSRA FRIDAY AFTERNOON
MM
//DISCUSSION...UPDATED 18Z...
WEAK HIGH PRESSURE DRIFTING EASTWARD HAS INFLUENCED A SOUTHEAST
FLOW. LAKE MICHIGAN HAS TAKEN HOLD OF THE WINDS AT ORD/MDW/GYY
WITH WINDS NOW EASTERLY OVER 10KT. OBSERVATIONS HAVE SHOWN SOME
GUSTS TO 15KT AS WELL FROM THE EAST TO SOUTHEAST. AFTER 01Z...THE
WINDS WILL RELAX SOME TO BECOME LESS THAN 10KT. OVERALL FLOW WILL
ALSO THEN BECOME SOUTHERLY AS LOW PRESSURE APPROACHES FROM THE
WEST EARLY FRIDAY. SOME RAIN SHOWERS ARE EXPECTED AND A CANOPY OF
BKN100 CEILINGS ARE EXPECTED AT MOST SITES.
TIMED OUT BEST CHANCE FOR TSRA BASED ON INSTABILITY INCREASING IN
THE 15-19Z TIMEFRAME...ALONG WITH THE POTENTIAL FOR A WAVE TO
HELP LIFT THINGS OFF DURING THAT TIME. LOOKING FORWARD...A BETTER
CHANCE FOR WIDESPREAD PRECIPITATION EXISTS EARLY SATURDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN EAST WINDS THROUGH 01Z WITH MEDIUM
CONFIDENCE IN WIND SPEEDS.
* MEDIUM CONFIDENCE IN SHRA AND TSRA OCCURRING FRIDAY...WITH LOW
CONFIDENCE ON TIMING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...PERIODIC SHRA/TSRA. MVFR POSSIBLE. SOUTHWEST WINDS.
SATURDAY....CHANCE SHRA EARLY. MVFR POSSIBLE. STRONG NORTH-
NORTHEAST WINDS.
SUNDAY...VFR/WX NIL. NORTHEAST WINDS.
MONDAY...VFR/WX NIL. EAST WINDS.
TUESDAY...VFR/WX NIL. SOUTHEAST WINDS.
WEDNESDAY...SLIGHT CHANCE SHRA. SOUTH WINDS.
KREIN
&&
.MARINE...
225 PM CDT
A SURFACE COLD FRONT DRAPED FROM WEST-TO-EAST ACROSS THE NORTHERN
PART OF THE LAKE WILL SHIFT NORTHWARD THIS EVENING. THIS WILL BE A
SOURCE FOR FOG ALONG IT AND THIS HAS BEEN SEEN ON VISIBLE SATELLITE
AT TIMES DURING THURSDAY. EVEN HIGHER MOISTURE WILL MOVE NORTHWARD
ACROSS THE LAKE ON FRIDAY ALLOWING FOR THE POSSIBILITY OF FOG AS
WELL...ESPECIALLY WHERE SHOWERS ARE NOT PREVALENT.
LOW PRESSURE WILL MOVE EAST INTO QUEBEC ON FRIDAY NIGHT AND STEER
A COLD FRONT SOUTHEASTWARD ACROSS THE LAKE. AS HIGH PRESSURE
BUILDS SOUTHWARD FROM ONTARIO ON SATURDAY...IT WILL DRIVE A STRONG
NORTHERLY WINDS FOR LATE MAY ACROSS THE CENTRAL AND SOUTHERN PARTS
OF THE LAKE. THIS WILL RESULT IN SMALL CRAFT ADVISORY CONDITIONS
FOR THE ILLINOIS AND INDIANA NEARSHORE AREAS SATURDAY AFTERNOON
AND NIGHT WITH LINGERING HIGH WAVES ON SUNDAY.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
229 PM CDT THU MAY 28 2015
.SHORT TERM...
225 PM CDT
THROUGH TONIGHT...
THE FORECAST AREA FINDS ITSELF BETWEEN TWO STATIONARY FRONTS
THIS AFTERNOON WITH A WEAK RIDGE OF HIGH PRESSURE SANDWICHED IN
BETWEEN DIRECTLY OVER THE AREA. THIS RIDGE HAS ALLOWED A LAKE
BREEZE WITH LAKESIDE COOLING AT THE CHICAGO SHORE ABOUT 14
DEGREES COOLER THAN INLAND AT ORD/MDW AS OF 200 PM. THE FRONT OF
INTEREST FOR OUR AREA TONIGHT WILL BE THE ONE TO THE SOUTH WHICH
WILL LIFT NORTH AS A WARM FRONT...BRINGING A RETURN TO MUGGY AIR
BY DAYBREAK...AS WELL AS KEEP NIGHTTIME TEMPERATURES MILD...EVEN
INCREASING THEM LATE TONIGHT ALONG THE LAKE SHORE AREAS.
MULTIPLE MID-LEVEL DISTURBANCES...SOME LIKELY CONVECTIVELY
ENHANCED...ARE NOTED ON WATER VAPOR AND RADAR MOSAIC IMAGERY ACROSS
THE CENTRAL PLAINS THIS AFTERNOON. ONE OF THESE JUST NORTH OF KANSAS
CITY AS OF 200 PM IS WELL ANALYZED BY THE LATEST RAP AND THIS IS
EXPECTED TO PROPAGATE INTO WISCONSIN OVERNIGHT...WITH ONE OR TWO
WEAKER IMPULSES TO ITS SOUTH APPROACHING THE AREA. WITH A 25-30 KT
LOW-LEVEL JET AHEAD OF THESE AND INCREASING MOISTURE AT THAT
HEIGHT...THERE WILL LIKELY BE SCATTERED SHOWERS OR STORMS FROM
SOUTHWEST WISCONSIN INTO NORTHWEST AND POSSIBLY NORTH CENTRAL
ILLINOIS OVERNIGHT.
MTF
&&
.LONG TERM...
TO BE ISSUED SHORTLY.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE WINDS VARYING FROM 080-120 AT 8-14KT THIS AFTERNOON
* -SHRA BECOMING TSRA FRIDAY AFTERNOON
MM
//DISCUSSION...UPDATED 18Z...
WEAK HIGH PRESSURE DRIFTING EASTWARD HAS INFLUENCED A SOUTHEAST
FLOW. LAKE MICHIGAN HAS TAKEN HOLD OF THE WINDS AT ORD/MDW/GYY
WITH WINDS NOW EASTERLY OVER 10KT. OBSERVATIONS HAVE SHOWN SOME
GUSTS TO 15KT AS WELL FROM THE EAST TO SOUTHEAST. AFTER 01Z...THE
WINDS WILL RELAX SOME TO BECOME LESS THAN 10KT. OVERALL FLOW WILL
ALSO THEN BECOME SOUTHERLY AS LOW PRESSURE APPROACHES FROM THE
WEST EARLY FRIDAY. SOME RAIN SHOWERS ARE EXPECTED AND A CANOPY OF
BKN100 CEILINGS ARE EXPECTED AT MOST SITES.
TIMED OUT BEST CHANCE FOR TSRA BASED ON INSTABILITY INCREASING IN
THE 15-19Z TIMEFRAME...ALONG WITH THE POTENTIAL FOR A WAVE TO
HELP LIFT THINGS OFF DURING THAT TIME. LOOKING FORWARD...A BETTER
CHANCE FOR WIDESPREAD PRECIPITATION EXISTS EARLY SATURDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE IN EAST WINDS THROUGH 01Z WITH MEDIUM
CONFIDENCE IN WIND SPEEDS.
* MEDIUM CONFIDENCE IN SHRA AND TSRA OCCURRING FRIDAY...WITH LOW
CONFIDENCE ON TIMING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...PERIODIC SHRA/TSRA. MVFR POSSIBLE. SOUTHWEST WINDS.
SATURDAY....CHANCE SHRA EARLY. MVFR POSSIBLE. STRONG NORTH-
NORTHEAST WINDS.
SUNDAY...VFR/WX NIL. NORTHEAST WINDS.
MONDAY...VFR/WX NIL. EAST WINDS.
TUESDAY...VFR/WX NIL. SOUTHEAST WINDS.
WEDNESDAY...SLIGHT CHANCE SHRA. SOUTH WINDS.
KREIN
&&
.MARINE...
225 PM CDT
A SURFACE COLD FRONT DRAPED FROM WEST-TO-EAST ACROSS THE NORTHERN
PART OF THE LAKE WILL SHIFT NORTHWARD THIS EVENING. THIS WILL BE A
SOURCE FOR FOG ALONG IT AND THIS HAS BEEN SEEN ON VISIBLE SATELLITE
AT TIMES DURING THURSDAY. EVEN HIGHER MOISTURE WILL MOVE NORTHWARD
ACROSS THE LAKE ON FRIDAY ALLOWING FOR THE POSSIBILITY OF FOG AS
WELL...ESPECIALLY WHERE SHOWERS ARE NOT PREVALENT.
LOW PRESSURE WILL MOVE EAST INTO QUEBEC ON FRIDAY NIGHT AND STEER
A COLD FRONT SOUTHEASTWARD ACROSS THE LAKE. AS HIGH PRESSURE
BUILDS SOUTHWARD FROM ONTARIO ON SATURDAY...IT WILL DRIVE A STRONG
NORTHERLY WINDS FOR LATE MAY ACROSS THE CENTRAL AND SOUTHERN PARTS
OF THE LAKE. THIS WILL RESULT IN SMALL CRAFT ADVISORY CONDITIONS
FOR THE ILLINOIS AND INDIANA NEARSHORE AREAS SATURDAY AFTERNOON
AND NIGHT WITH LINGERING HIGH WAVES ON SUNDAY.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1258 PM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 1045 AM CDT THO MAY 28 2015
MORNING SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER THE
EASTERN GREAT LAKES...WITH RIDGE AXIS EXTENDING WESTWARD ACROSS
NORTH-CENTRAL ILLINOIS. FURTHER SOUTH...A NEARLY STATIONARY
FRONTAL BOUNDARY IS IN PLACE JUST NORTH OF THE OHIO RIVER. AS THE
HIGH SHIFTS OFF TO THE EAST...THE FRONT WILL BEGIN LIFTING BACK
NORTHWARD LATER TODAY. HIGH-RES MODELS CONTINUE TO SUGGEST WIDELY
SCATTERED CONVECTION DEVELOPING ALONG/NEAR THE BOUNDARY THIS
AFTERNOON AND EVENING. HRRR HAS BEEN WAY TOO AGGRESSIVE WITH
CONVECTIVE DEVELOPMENT OVER THE PAST FEW DAYS AND CONTINUES TO BE
TODAY AS WELL. RAPID REFRESH IS VERIFYING BETTER THIS MORNING AND
SEEMS TO HAVE A MORE REASONABLE SOLUTION FOR THE AFTERNOON. WILL
THEREFORE CONTINUE TO MENTION JUST SLIGHT CHANCE POPS ALONG/SOUTH
OF A RUSHVILLE...TO SPRINGFIELD...TO OLNEY LINE. THINK NORTHWARD
EXTENT OF PRECIP WILL BE LIMITED DUE TO THE PRESENCE OF THE RIDGE
AXIS ACROSS THE CENTRAL/NORTHERN KILX CWA.
&&
.SHORT TERM...(TODAY)
ISSUED AT 338 AM CDT THO MAY 28 2015
SURFACE HIGH PRESSURE WILL DOMINATE THE WEATHER OVER THE AREA TODAY
WITH MOSTLY SUNNY SKIES AND LIGHTER WINDS. A BOUNDARY IS SOUTH OF
CWA AND COULD BECOME ACTIVE THIS AFTERNOON WITH SHOWERS AND
THUNDERSTORMS. HOWEVER ALL THIS WILL REMAIN SOUTH AND SOUTHWEST OF
THE CWA SO WILL ONLY HAVE SLIGHT CHANCE POPS IN THE SOUTHWEST ONLY
FOR THIS AFTERNOON. SHOULD BE LOTS OF SUNSHINE SO TEMPS SHOULD WARM
INTO THE MIDDLE 80S ACROSS THE AREA BY THIS AFTERNOON.
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 338 AM CDT THO MAY 28 2015
NOT MUCH OF A SHIFT IN THE FORECAST THIS MORNING WITH SOME FINE
TUNING ON THE ARRIVAL OF THE FRONT FRI NIGHT/SAT. BEFORE THEN, THE
PRECIP IS STARTING TO MOVE INTO THE REGION LATER TONIGHT IN THE
EXTREME WEST...MODELS HINTING AT SOME WAA SHOWERS DEVELOPING AHEAD
OF THE NEXT SYSTEM AS THE WINDS VEER AROUND TO MORE SOUTHERLY JUST
OFF THE SFC. BULK OF THE SYSTEMS LIFT SHOULD NOT ARRIVE UNTIL
FRIDAY AHEAD OF AND WITH THE BOUNDARY. TIMING OF THE SYSTEM
STARTING TO PUT FRIDAY AFTERNOON IN CONTENTION FOR SEVERE WEATHER.
THOUGH THE SHEAR MAY REMAIN RELATIVELY WEAK, THE WARM AND MUGGY
AIRMASS WILL PROVIDE PLENTY OF INSTABILITY FOR AN APPROACHING FRONT.
SO FAR, SPC HAS KEPT MUCH OF CENTRAL IL IN A MARGINAL THREAT FOR
FRIDAY. SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE
OVERNIGHT AND INTO SATURDAY...WHEN THE MARGINAL THREAT SHIFTS TO THE
EXTREME SE ALONG AND NEAR THE I-70 CORRIDOR. MUCH COOLER AIR MOVING
IN BEHIND THE BOUNDARY, AND THE WEEKEND WRAPS UP UNSEASONABLY COOL
FOR SUNDAY THROUGH TUESDAY WITH TEMPS IN THE 60S AND 70S. SUN NIGHT
THROUGH WED NIGHT SHOULD SEE LITTLE CHANCE FOR RAIN ALTHOUGH THE
STILL TRYING TO PULL IN SOME POPS FROM CONVECTIVE NOISE IN SOME
OF THE MODELS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1258 PM CDT THO MAY 28 2015
CU-FIELD HAS DEVELOPED ALONG/SOUTH OF A STATIONARY FRONTAL
BOUNDARY ACROSS SOUTH-CENTRAL ILLINOIS EARLY THIS AFTERNOON AND
WILL CONTINUE TO DEVELOP/SPREAD SLOWLY NORTHWARD OVER THE NEXT FEW
HOURS. MODELS ARE SHOWING ISOLATED SHOWERS/STORMS DEVELOPING IN
THE VICINITY OF THE FRONT...THEN TRACKING NORTHWARD ACROSS MAINLY
WESTERN ILLINOIS LATER THIS AFTERNOON AND EVENING. LATEST RADAR
MOSAIC IS SHOWING A FEW SHOWERS BEGINNING TO POP UP SOUTH AND WEST
OF SAINT LOUIS...SO THIS SOLUTION SEEMS REASONABLE. HAVE THEREFORE
INCLUDED VCSH AT BOTH KSPI AND KPIA THIS EVENING. FURTHER
EAST...WILL REMAIN DRY WITH ONLY HIGH CLOUDINESS EXPECTED. AS A
FRONTAL BOUNDARY BEGINS TO APPROACH FROM THE NORTHWEST...HIGH
DEWPOINT AIR WILL OVERSPREAD ALL OF CENTRAL ILLINOIS BY FRIDAY
MORNING. MAIN FOCUS FOR CONVECTION WILL REMAIN WEST OF THE AREA
UNTIL LATE IN THE DAY...SO HAVE KEPT TAFS DRY THROUGH 18Z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...AUTEN
LONG TERM...HJS
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 1045 AM CDT THU MAY 28 2015
MORNING SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER THE
EASTERN GREAT LAKES...WITH RIDGE AXIS EXTENDING WESTWARD ACROSS
NORTH-CENTRAL ILLINOIS. FURTHER SOUTH...A NEARLY STATIONARY
FRONTAL BOUNDARY IS IN PLACE JUST NORTH OF THE OHIO RIVER. AS THE
HIGH SHIFTS OFF TO THE EAST...THE FRONT WILL BEGIN LIFTING BACK
NORTHWARD LATER TODAY. HIGH-RES MODELS CONTINUE TO SUGGEST WIDELY
SCATTERED CONVECTION DEVELOPING ALONG/NEAR THE BOUNDARY THIS
AFTERNOON AND EVENING. HRRR HAS BEEN WAY TOO AGGRESSIVE WITH
CONVECTIVE DEVELOPMENT OVER THE PAST FEW DAYS AND CONTINUES TO BE
TODAY AS WELL. RAPID REFRESH IS VERIFYING BETTER THIS MORNING AND
SEEMS TO HAVE A MORE REASONABLE SOLUTION FOR THE AFTERNOON. WILL
THEREFORE CONTINUE TO MENTION JUST SLIGHT CHANCE POPS ALONG/SOUTH
OF A RUSHVILLE...TO SPRINGFIELD...TO OLNEY LINE. THINK NORTHWARD
EXTENT OF PRECIP WILL BE LIMITED DUE TO THE PRESENCE OF THE RIDGE
AXIS ACROSS THE CENTRAL/NORTHERN KILX CWA.
&&
.SHORT TERM...(TODAY)
ISSUED AT 338 AM CDT THU MAY 28 2015
SURFACE HIGH PRESSURE WILL DOMINATE THE WEATHER OVER THE AREA TODAY
WITH MOSTLY SUNNY SKIES AND LIGHTER WINDS. A BOUNDARY IS SOUTH OF
CWA AND COULD BECOME ACTIVE THIS AFTERNOON WITH SHOWERS AND
THUNDERSTORMS. HOWEVER ALL THIS WILL REMAIN SOUTH AND SOUTHWEST OF
THE CWA SO WILL ONLY HAVE SLIGHT CHANCE POPS IN THE SOUTHWEST ONLY
FOR THIS AFTERNOON. SHOULD BE LOTS OF SUNSHINE SO TEMPS SHOULD WARM
INTO THE MIDDLE 80S ACROSS THE AREA BY THIS AFTERNOON.
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 338 AM CDT THU MAY 28 2015
NOT MUCH OF A SHIFT IN THE FORECAST THIS MORNING WITH SOME FINE
TUNING ON THE ARRIVAL OF THE FRONT FRI NIGHT/SAT. BEFORE THEN, THE
PRECIP IS STARTING TO MOVE INTO THE REGION LATER TONIGHT IN THE
EXTREME WEST...MODELS HINTING AT SOME WAA SHOWERS DEVELOPING AHEAD
OF THE NEXT SYSTEM AS THE WINDS VEER AROUND TO MORE SOUTHERLY JUST
OFF THE SFC. BULK OF THE SYSTEMS LIFT SHOULD NOT ARRIVE UNTIL
FRIDAY AHEAD OF AND WITH THE BOUNDARY. TIMING OF THE SYSTEM
STARTING TO PUT FRIDAY AFTERNOON IN CONTENTION FOR SEVERE WEATHER.
THOUGH THE SHEAR MAY REMAIN RELATIVELY WEAK, THE WARM AND MUGGY
AIRMASS WILL PROVIDE PLENTY OF INSTABILITY FOR AN APPROACHING FRONT.
SO FAR, SPC HAS KEPT MUCH OF CENTRAL IL IN A MARGINAL THREAT FOR
FRIDAY. SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE
OVERNIGHT AND INTO SATURDAY...WHEN THE MARGINAL THREAT SHIFTS TO THE
EXTREME SE ALONG AND NEAR THE I-70 CORRIDOR. MUCH COOLER AIR MOVING
IN BEHIND THE BOUNDARY, AND THE WEEKEND WRAPS UP UNSEASONABLY COOL
FOR SUNDAY THROUGH TUESDAY WITH TEMPS IN THE 60S AND 70S. SUN NIGHT
THROUGH WED NIGHT SHOULD SEE LITTLE CHANCE FOR RAIN ALTHOUGH THE
SUPERBLEND STILL TRYING TO PULL IN SOME POPS FROM CONVECTIVE NOISE
IN SOME OF THE MODELS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 707 AM CDT THU MAY 28 2015
VFR CONDITIONS WILL PREVAIL AT ALL SITES NEXT 24HRS. BLOW OFF CIRRUS
CLOUDS FROM THE DYING MCS OVER NORTHWEST MO WILL SPREAD OVER THE
AREA THIS MORNING AND THROUGH THIS AFTERNOON. A FRONTAL BOUNDARY
EXTENDING FROM SOUTHERN IL NORTHWESTWARD INTO PARTS OF MO WILL
LIFT NORTHWARD AND BY THIS EVENING A BROKEN DECK OF MID CLOUDS
WILL DEVELOP AND EFFECT EACH SITE THIS EVENING...ALONG WITH
SCATTERED CU. PCPN WILL DEVELOP OUT WEST ALONG THIS FRONT ACROSS
MO AND COULD ADVECT INTO THE AREA OVERNIGHT. HOWEVER...LOTS OF
UNCERTAINTY HERE SO WILL LEAVE OUT ANY SHOWERS/TSTORMS FOR NOW AND
JUST INCREASE CU CLOUDS TO BECOME BROKEN. WINDS WILL BE SOUTHEAST
THROUGH THE DAY AROUND 10-12KTS AND THEN BECOME SOUTHERLY WHEN THE
FRONT MOVES NORTH THROUGH THE AREA LATE TONIGHT. WIND SPEEDS WILL
DECREASE AFTER SUNSET.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...AUTEN
LONG TERM...HJS
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
306 AM CDT THU MAY 28 2015
.UPDATE...
916 PM CDT
FOR EVENING UPDATE...
GOING FORECAST IN GOOD SHAPE THIS EVENING...WITH ONLY A FEW
TWEAKS TO GRIDS TO MATCH HOURLY OBS TRENDS.
WEAK SURFACE COLD HAD FRONT CLEARED THE CWA BY EARLY THIS
EVENING... WITH CLEARING SKIES IN SUBSIDENCE BEHIND MID-LEVEL
SHORT WAVE PULLING AWAY TO THE EAST. ONLY A SUBTLE DROP IN DEW
POINT TEMPS INTO THE MID-50S AND FAIRLY WEAK SURFACE HIGH PRESSURE
RIDGE NOTED ACROSS AREA PER METARS...WITH LIGHT WINDS ALREADY
TURNING BACK TO THE SOUTH ACROSS IA-WI. WINDS ALONG THE LAKE
MICHIGAN SHORE THAT HAD TURNED NORTHEAST BEHIND THE FRONT WERE
ALSO COMING AROUND TO THE SOUTH FROM WAUKEGAN NORTHWARD. THUS
EFFECTS OF THE WEAK COLD FRONT TO BE MINIMAL WITH MILD LOWS NEAR
60 TONIGHT AND WARMER TEMPS EXPECTED THURSDAY.
OF SOME INTEREST IS AN AREA OF THUNDERSTORMS OVER NORTHERN WI...
WHICH HAVE BEEN MAINTAINING THEIR STRENGTH OVER THE LAST COUPLE OF
HOURS WITHIN AXIS OF HIGHER DEW POINTS TO OUR WEST/NORTH. WATER
VAPOR IMAGERY SUGGESTS A SHORT WAVE OVER NORTHERN WI MAY BE A
LITTLE SHARPER THAN MUCH OF THE AVAILABLE GUIDANCE DEPICTS...WHICH
COMBINED WITH 1700+ J/KG MLCAPE WILL PROBABLY ALLOW THESE STORMS
TO CONTINUE TO WORK SOUTHEAST FOR THE NEXT FEW HOURS. RECENT RUNS
OF THE HRRR INDICATE GRADUAL DECAY WHICH IS TO BE EXPECTED WITH
DIURNAL DECREASE IN INSTABILITY AND MORE WESTERLY FLOW ABOVE THE
SFC...THOUGH THE HRRR DOES CONTINUE TO INDICATE SOME REMNANT
ISOLATED SHOWERS AS FAR SOUTH AS THE MKE AREA OVERNIGHT. MAY ADD
SOME POPS FOR ISOLATED SHOWERS OUT OVER SOUTH/CENTRAL LAKE MI LATE
TONIGHT...THOUGH AM NOT EXPECTING PRECIP TO AFFECT WFO LOT LAND
AREAS.
RATZER
&&
.SHORT TERM...
307 PM CDT
THROUGH THURSDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH SHOWER/THUNDERSTORM
TRENDS BY THE END OF THE WORK WEEK INTO THE WEEKEND...AND THEN
WITH COOLER TEMPS EXPECTED THIS WEEKEND INTO THE START OF NEXT
WEEK.
COLD FRONT WHICH PUSHED THROUGH THE CWA TODAY CONTINUES OFF TO
THE EAST THIS AFTERNOON...WHILE MID/UPPER LEVEL TROUGH OVER THE
UPPER MIDWEST AND GREAT LAKES LIFTS TO THE EAST/NORTHEAST.
MODERATE INSTABILITY WHICH WAS IN PLACE TODAY HAS WEAKENED AND
WILL FURTHER WEAKEN THIS AFTERNOON INTO THE EVENING...AS 50 DEGREE
DEWPOINT AIR MOVES ACROSS THE CWA. ANY MORE ROBUST
SHOWER/THUNDERSTORM DEVELOPMENT THIS AFTERNOON WILL REMAIN EAST OF
THE AREA...WITH ANY ISOLATED SHOWERY ACTIVITY TO DIMINISH HERE IN
THE NEAR TERM. CLOUD COVER WILL LIKEWISE DIMINISH THIS
EVENING...WITH MOSTLY CLEAR SKIES LIKELY TONIGHT.
IN THE WAKE OF THE DEPARTING MID/UPPER LEVEL TROUGH...RISING
HEIGHTS ALOFT WILL HELP SET THE STAGE FOR A DRY/SUNNY DAY WITH
WARM AND ABOVE NORMAL TEMPS IN THE LOW TO MID 80S ON THURSDAY. THE
EXCEPTION WILL BE FOR AREAS NEAR THE LAKE IN ILLINOIS WHERE
COOLER TEMPS IN THE 70S WILL BE OBSERVED WITH ONSHORE FLOW. A
LITTLE UNCERTAINTY WITH HOW HIGH THE TEMPS WILL GET IN THIS
LOCATION BEFORE THE WINDS TURN...BUT THINK TEMPS WILL HAVE A GOOD
CHANCE OF RISING QUICKLY IN THE MORNING BEFORE THIS OCCURS. SO DID
BUMP UP TEMPS AND EVEN FOR AREAS NEAR THE LAKE IN INDIANA...WHERE
SOUTHERLY FLOW SHOULD ALLOW LESS OF AN IMPACT FROM THE LAKE.
RODRIGUEZ
&&
.LONG TERM...
247 AM CDT
FRIDAY THROUGH WEDNESDAY...
FRIDAY...
MAIN CHALLENGES FOR FRI WILL BE ON PRECIP TIMING AND COVERAGE.
GUIDANCE HAS INDICATED SOME SLOWING TO THE DEPARTING SFC
RIDGE...WITH MID-LVL HEIGHTS NOT BEGINNING TO FALL UNTIL AFT
DAYBREAK FRI. THE MORE POTENT LOBE OF VORTICITY WILL BE ROUNDING THE
TROUGH AXIS EARLY FRI...THEN FORMING A SFC WAVE FEATURE ACROSS THE
SOUTHERN PLAINS. THE QUASI-STATIONARY BOUNDARY WILL BE ORIENTED FROM
THE SOUTHERN PLAINS NORTHEAST THROUGH THE UPPER MIDWEST. BUT WITH
THE MINOR DELAY IN DEPARTING RIDGE...THIS MAY PROVIDE A WEAK BUCKLE
TO THE GREATER PRECIP COVERAGE ONLY TEMPORARILY FRI MORNING. BY
MIDDAY THE BOUNDARY WILL BE DRIFTING EAST...WITH ABUNDANT LOW LEVEL
MOISTURE ADVECTING NORTH INTO THIS FEATURE. DEW POINTS WILL HOVER IN
THE LOW/MID 60S...AS PWAT VALUES APPROACH 1.5 INCHES. 850MB V-WIND
COMPONENT SUGGESTS WINDS WILL NOT BE TOO STRONG...SO AT THIS TIME
WOULD NOT SUSPECT AS THE SFC WAVE LIFTS NORTHEAST ALONG THE BOUNDARY
GROWTH IN CONVECTION TO BE VERY LARGE. HOWEVER...IT DOES APPEAR TO
BE AN IDEAL SETUP FOR EMBEDDED THUNDER. WITH THE UPSTREAM MID-LVL
VORT STRENGTHENING OVER CENTRAL CANADA...THIS WILL LIKELY ALLOW THE
QUASI-STATIONARY BOUNDARY TO FURTHER ENHANCE. THIS COULD AID IN
PRECIP PRODUCTION WITH THE BOUNDARY SLIDING OVERHEAD FRI
NIGHT.
TEMPS WILL EQUALLY BE A CHALLENGE FRI...GIVEN THE THICK SOLAR
SHIELDING POISED TO LIMIT SFC HEATING. THE ABUNDANT LOW LEVEL
MOISTURE WILL ABSORB ANY HEAT...MAKING IT DIFFICULT TO WARM AND
PERHAPS KEEPING TEMPS A FEW DEGREES LOWER THAN CURRENTLY PROGGED.
HAVE NUDGED TEMPS IN THE FAR NORTHERN CWFA DOWN A COUPLE DEGREES TO
REFLECT THIS INTO THE UPR 70S...MEANWHILE FURTHER SOUTH HAVE HELD
ONTO THE 80 TO LOW 80S RANGE.
SATURDAY THROUGH MIDDLE OF NEXT WEEK... ENSEMBLES HAVE CONTINUED TO
PROG A HIGH AMPLITUDE RIDGE ACROSS WESTERN CANADA AT THE START OF
THE WEEKEND...THEN SLOWLY WEAKENING THIS FEATURE AS THE CENTRAL
CONUS TRANSITIONS INTO A RELATIVELY FLAT WEST-EAST FLOW BY TUE/WED
OF NEXT WEEK. THE MAIN STORY FOR THE WEEKEND WILL BE ON THE TEMPS
ABRUPTLY CHANGEING FROM EARLY SUMMER TO MID-SPRING...WITH A STOUT
FRONTAL BOUNDARY SWEEPING ACROSS THE FORECAST AREA SAT MIDDAY. THIS
WILL BRING MUCH COOLER AIR AS WINDS QUICKLY VEER NORTH/NORTHEAST
AND BLEED THE MUCH COOLER MARINE AIR FROM LAKE MICHIGAN OVER
NORTHEAST IL/NORTHWEST IN SAT/SUN. HIGHS SAT MAY STRUGGLE TO WARM
BEYOND THE UPR 50S ACROSS NORTHEAST IL/NORTHWEST IN...WITH ONLY
LOW 60S ELSEWHERE.
WITH FLOW BECOMING SOMEWHAT FLAT TOWARDS MON/TUE ACROSS THE
CENTRAL CONUS...THIS WILL HELP TO FLUSH THE SFC RIDGE EAST FROM
THE GREAT LAKES REGION. THIS WILL LIKELY ALLOW TEMPS TO SLOWLY
RETURN TO SEASONAL CONDS BY MIDDLE OF NEXT WEEK...HOWEVER
CURRENTLY GUIDANCE INDICATES A DRY STRETCH AS MID-LVL HEIGHTS MAY
BEGIN TO NUDGE UP CLOSER TO TUE/WED. BUT CONFIDENCE IN THE FINAL
FEW PERIODS OF THE EXTENDED ARE CURRENTLY LOW.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* ESELY WINDS AROUND 10 KT THURSDAY AFTERNOON FOLLOWING LAKE
BREEZE PASSAGE.
KREIN
//DISCUSSION...UPDATED 00Z...
AS WEAK HIGH PRESSURE SETTLES OVER NRN IL/IN/SRN LAKE
MICHIGAN...WINDS HAVE DROPPED OF TO CALM/LGT AND VRBL. AN AREA OF
SHOWERS IS QUICKLY DROPPING THROUGH ECNTRL WI AND CNTRL LAKE
MICHIGAN WITH AN OUTFLOW BOUNDARY RACING OUT AHEAD. LATEST RADAR
TRENDS SUGGEST THAT THE PCPN IS WEAKENING AND MOVING SELY ENOUGH
THAT IT WILL MISS THE TERMINALS...EVEN GYY. QUIET CONDITIONS
SHOULD PREVAIL THROUGH THE REMAINDER OF THE NIGHT...BUT BY EARLY
MORNING...A DEEPENING TROUGH OVER THE CNTRL/NRN PLAINS WILL HELP
TURN WINDS TO PREVAILING SELY BY DAYBREAK...WITH SPEEDS LESS THAN
10 KT. THE WEAK SELY GRADIENT WILL REMAIN IN PLACE THROUGH THE
DAY...AND SHOULD BE WEAK ENOUGH TO ALLOW FOR A LAKE BREEZE TO
DEVELOP. THE LATEST HIGH RES MODEL GUIDANCE AGREES WITH
CONVENTIONAL WISDOM THAT A LAKE BREEZE SHOULD DEVELOP UNDER THE
EXPECTED PATTERN...WITH WINDS SHIFTING TO JUST SOUTH OF EAST AND
INCREASING TO ARND 10KT.
AS THE SFC TROUGH BEGINS TO MOVE EAST ACROSS THE NORTHERN PLAINS
AND TOWARD THE UPPER MISSISSIPPI VALLEY LAKE THURSDAY
NIGHT...WINDS WILL VEER TO SOUTHERLY. WARM/MOIST ADVECTION UNDER
THE SOUTHERLY FLOW WILL BRING INCREASING LOW AND MID CLOUDS AND A
CHANCE OF SHOWERS BY THE EARLY MORNING HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN LAKE BREEZE WIND SHIFT TIMING AND SPEED/DIRECTION
FOLLOWING LAKE BREEZE PASSAGE.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...PERIODIC SHRA/TSRA. MVFR POSSIBLE. SOUTHWEST WINDS.
SATURDAY...CHANCE SHRA. MVFR POSSIBLE. STRONG NORTH-NORTHEAST
WINDS.
SUNDAY...VFR/WX NIL. NORTHEAST WINDS.
MONDAY...VFR/WX NIL. EAST WINDS.
TUESDAY...VFR/WX NIL. SOUTH WINDS.
KJB
&&
.MARINE...
247 AM CDT
WEAK SFC RIDGE OF HIGH PRESSURE CENTERED OVER EASTERN
ONTARIO...WITH SOME LINGERING INFLUENCE OF DRY AIR ACROSS LAKE
MICHIGAN FOR THE BULK OF TODAY. THE WESTERN GREAT LAKES WILL BEGIN
TO SEE THE SOUTHERLY FLOW THIS AFTERNOON/EVENING...AS WINDS
INCREASE. A SLOW MOVING FRONTAL BOUNDARY ORIENTED OVER THE
SOUTHERN PLAINS STRETCHES NORTH TO JUST WEST OF LAKE SUPERIOR.
THSI BOUNDARY WILL BEGIN TO INCH EAST TOWARDS THE NORTHERN
PORTIONS OF LAKE MICHIGAN FRI MORNING...ALLOWING THE GRADIENT TO
TIGHTEN AND SOUTHERLY WINDS TO INCREASE. THEN THE FRONTAL BOUNDARY
WILL SLIDE SOUTHEAST SLOWLY ACROSS LAKE MICHIGAN...ALONG WITH THE
GRADIENT TIGHTENING BY FRIDAY NIGHT INTO SATURDAY. A STRONG RIDGE
OF HIGH PRESSURE WILL DROP SOUTH FROM CENTRAL CANADA ALONG THE
BACK EDGE OF THE FRONT...HELPING TO INCREASE A PERIOD OF NORTH GALES
SATURDAY FOR THE CENTRAL/SOUTHERN PORTIONS OF LAKE MICHIGAN.
GUIDANCE HAS BACKED OFF A TOUCH ON THE WIND SPEEDS...HOWEVER A
GALE WATCH MAY STILL NEED TO BE ISSUED. THE STRONG WINDS COUPLED
WITH MUCH COOLER AIR WILL EASILY BUILD WAVES FOR THE SOUTHERN HALF
OF THE LAKE SATURDAY. COOL AIR AND NORTH/NORTHEAST WINDS WILL
CONTINUE TO OCCUR SAT NIGHT THRU SUN...LIKELY MAINTAINING LARGER
WAVES ALONG THE IL/IN NEARSHORE WATERS.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1241 AM CDT THU MAY 28 2015
.UPDATE...
916 PM CDT
FOR EVENING UPDATE...
GOING FORECAST IN GOOD SHAPE THIS EVENING...WITH ONLY A FEW
TWEAKS TO GRIDS TO MATCH HOURLY OBS TRENDS.
WEAK SURFACE COLD HAD FRONT CLEARED THE CWA BY EARLY THIS
EVENING... WITH CLEARING SKIES IN SUBSIDENCE BEHIND MID-LEVEL
SHORT WAVE PULLING AWAY TO THE EAST. ONLY A SUBTLE DROP IN DEW
POINT TEMPS INTO THE MID-50S AND FAIRLY WEAK SURFACE HIGH PRESSURE
RIDGE NOTED ACROSS AREA PER METARS...WITH LIGHT WINDS ALREADY
TURNING BACK TO THE SOUTH ACROSS IA-WI. WINDS ALONG THE LAKE
MICHIGAN SHORE THAT HAD TURNED NORTHEAST BEHIND THE FRONT WERE
ALSO COMING AROUND TO THE SOUTH FROM WAUKEGAN NORTHWARD. THUS
EFFECTS OF THE WEAK COLD FRONT TO BE MINIMAL WITH MILD LOWS NEAR
60 TONIGHT AND WARMER TEMPS EXPECTED THURSDAY.
OF SOME INTEREST IS AN AREA OF THUNDERSTORMS OVER NORTHERN WI...
WHICH HAVE BEEN MAINTAINING THEIR STRENGTH OVER THE LAST COUPLE OF
HOURS WITHIN AXIS OF HIGHER DEW POINTS TO OUR WEST/NORTH. WATER
VAPOR IMAGERY SUGGESTS A SHORT WAVE OVER NORTHERN WI MAY BE A
LITTLE SHARPER THAN MUCH OF THE AVAILABLE GUIDANCE DEPICTS...WHICH
COMBINED WITH 1700+ J/KG MLCAPE WILL PROBABLY ALLOW THESE STORMS
TO CONTINUE TO WORK SOUTHEAST FOR THE NEXT FEW HOURS. RECENT RUNS
OF THE HRRR INDICATE GRADUAL DECAY WHICH IS TO BE EXPECTED WITH
DIURNAL DECREASE IN INSTABILITY AND MORE WESTERLY FLOW ABOVE THE
SFC...THOUGH THE HRRR DOES CONTINUE TO INDICATE SOME REMNANT
ISOLATED SHOWERS AS FAR SOUTH AS THE MKE AREA OVERNIGHT. MAY ADD
SOME POPS FOR ISOLATED SHOWERS OUT OVER SOUTH/CENTRAL LAKE MI LATE
TONIGHT...THOUGH AM NOT EXPECTING PRECIP TO AFFECT WFO LOT LAND
AREAS.
RATZER
&&
.SHORT TERM...
307 PM CDT
THROUGH THURSDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH SHOWER/THUNDERSTORM
TRENDS BY THE END OF THE WORK WEEK INTO THE WEEKEND...AND THEN
WITH COOLER TEMPS EXPECTED THIS WEEKEND INTO THE START OF NEXT
WEEK.
COLD FRONT WHICH PUSHED THROUGH THE CWA TODAY CONTINUES OFF TO
THE EAST THIS AFTERNOON...WHILE MID/UPPER LEVEL TROUGH OVER THE
UPPER MIDWEST AND GREAT LAKES LIFTS TO THE EAST/NORTHEAST.
MODERATE INSTABILITY WHICH WAS IN PLACE TODAY HAS WEAKENED AND
WILL FURTHER WEAKEN THIS AFTERNOON INTO THE EVENING...AS 50 DEGREE
DEWPOINT AIR MOVES ACROSS THE CWA. ANY MORE ROBUST
SHOWER/THUNDERSTORM DEVELOPMENT THIS AFTERNOON WILL REMAIN EAST OF
THE AREA...WITH ANY ISOLATED SHOWERY ACTIVITY TO DIMINISH HERE IN
THE NEAR TERM. CLOUD COVER WILL LIKEWISE DIMINISH THIS
EVENING...WITH MOSTLY CLEAR SKIES LIKELY TONIGHT.
IN THE WAKE OF THE DEPARTING MID/UPPER LEVEL TROUGH...RISING
HEIGHTS ALOFT WILL HELP SET THE STAGE FOR A DRY/SUNNY DAY WITH
WARM AND ABOVE NORMAL TEMPS IN THE LOW TO MID 80S ON THURSDAY. THE
EXCEPTION WILL BE FOR AREAS NEAR THE LAKE IN ILLINOIS WHERE
COOLER TEMPS IN THE 70S WILL BE OBSERVED WITH ONSHORE FLOW. A
LITTLE UNCERTAINTY WITH HOW HIGH THE TEMPS WILL GET IN THIS
LOCATION BEFORE THE WINDS TURN...BUT THINK TEMPS WILL HAVE A GOOD
CHANCE OF RISING QUICKLY IN THE MORNING BEFORE THIS OCCURS. SO DID
BUMP UP TEMPS AND EVEN FOR AREAS NEAR THE LAKE IN INDIANA...WHERE
SOUTHERLY FLOW SHOULD ALLOW LESS OF AN IMPACT FROM THE LAKE.
RODRIGUEZ
&&
.LONG TERM...
307 PM CDT
THURSDAY NIGHT THROUGH WEDNESDAY...
WITH STEERING FLOW KEEPING MOST OF THE ENERGY WELL NORTH OF THE
CWA THURSDAY NIGHT...EXPECT DRY CONDITIONS THURSDAY EVENING.
HOWEVER...NORTHEASTWARD MOVING SHORT WAVE ENERGY AND VEERING LLJ
COULD ALLOW FOR SOME PRECIP TO MOVE ACROSS NORTHERN ILLINOIS. WITH
THIS POSSIBILITY DID LEAVE CHANCE POPS ACROSS NORTH CENTRAL
ILLINOIS...BUT WITH MOST AREAS LIKELY REMAINING DRY DURING THIS
PERIOD. INSTABILITY DOES NOT LOOK TO BE OVERLY GREAT DURING THIS
PERIOD AND AM NOT TOO CONCERNED WITH THUNDER...BUT WITH AT LEAST
WEAK INSTABILITY AND A DECENT LLJ...DID LEAVE MENTION OF THUNDER
IN THE GRIDS. UPPER LEVEL TROUGH TO THE WEST/NORTHWEST WILL DIP
ACROSS THE REGION ON FRIDAY AND ALLOW FOR THIS MORE ENERGETIC FLOW
TO DRAW CLOSER TO THE CWA. ALTHOUGH BETTER LOW/MID LEVEL
CONVERGENCE SHOULD REMAIN TO THE NORTH IN WISCONSIN THROUGH THE
DAY FRIDAY...INCREASING INSTABILITY WITH LITTLE CIN IN THE
PRESENCE OF 60 DEGREE DEWPOINTS ALONG WITH INCREASING LARGE SCALE
LIFT SHOULD ALLOW FOR SCATTERED SHOWER/THUNDERSTORM DEVELOPMENT.
INITIALLY THIS WILL BE FOR AREAS ACROSS NORTH CENTRAL
ILLINOIS...BUT DO THINK THAT AT LEAST ISOLATED TO WIDELY SCATTERED
DEVELOPMENT WILL BE POSSIBLE FOR REMAINING AREAS IN THE AFTERNOON.
WEAKER MID AND UPPER LEVEL FLOW SHOULD LIMIT INTENSITY OF ANY
DEVELOPMENT...ALTHOUGH CANNOT RULE OUT ISOLATED STRONGER STORM
WITH STRONG GUSTS THE MAIN HAZARD. ALSO...INCREASING MOISTURE WILL
ONCE AGAIN HELP FOR HEAVIER DOWNPOURS DURING THIS TIME.
FRIDAY NIGHT INTO SATURDAY MORNING APPEAR TO BE THE BEST PERIODS
FOR WIDESPREAD PRECIP DEVELOPMENT AND HAVE INCREASED TO
CATEGORICAL POPS DURING THIS PERIOD. THIS WILL OCCUR AS THE MID
LEVEL TROUGH AND ASSOCIATED SURFACE LOW AND FRONT PUSH THROUGH.
WITH FLOW STILL REMAINING WEAK AND WITH DIMINISHING INSTABILITY
THROUGHOUT THE NIGHT...NOT OVERLY CONCERNED WITH WIDESPREAD SEVERE
STORMS. HOWEVER...STRONGER FORCING COULD STILL ALLOW FOR ISOLATED
STRONG DEVELOPMENT. WITH AN ABUNDANCE OF MOISTURE STILL IN
PLACE...HEAVIER RAIN WOULD LIKELY BE THE MAIN HAZARD. PRECIP WILL
LIKELY LINGER SATURDAY MORNING BUT PUSHING SOUTH DURING THIS TIME.
ON THE BACKSIDE OF THIS FRONT/PRECIP...STRONGER NORTHERLY WINDS
WILL ALLOW MUCH COOLER AIR TO MOVE OVER THE REGION...WITH TEMPS
LIKELY FALLING THROUGHOUT THE DAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* ESELY WINDS AROUND 10 KT THURSDAY AFTERNOON FOLLOWING LAKE
BREEZE PASSAGE.
KREIN
//DISCUSSION...UPDATED 00Z...
AS WEAK HIGH PRESSURE SETTLES OVER NRN IL/IN/SRN LAKE
MICHIGAN...WINDS HAVE DROPPED OF TO CALM/LGT AND VRBL. AN AREA OF
SHOWERS IS QUICKLY DROPPING THROUGH ECNTRL WI AND CNTRL LAKE
MICHIGAN WITH AN OUTFLOW BOUNDARY RACING OUT AHEAD. LATEST RADAR
TRENDS SUGGEST THAT THE PCPN IS WEAKENING AND MOVING SELY ENOUGH
THAT IT WILL MISS THE TERMINALS...EVEN GYY. QUIET CONDITIONS
SHOULD PREVAIL THROUGH THE REMAINDER OF THE NIGHT...BUT BY EARLY
MORNING...A DEEPENING TROUGH OVER THE CNTRL/NRN PLAINS WILL HELP
TURN WINDS TO PREVAILING SELY BY DAYBREAK...WITH SPEEDS LESS THAN
10 KT. THE WEAK SELY GRADIENT WILL REMAIN IN PLACE THROUGH THE
DAY...AND SHOULD BE WEAK ENOUGH TO ALLOW FOR A LAKE BREEZE TO
DEVELOP. THE LATEST HIGH RES MODEL GUIDANCE AGREES WITH
CONVENTIONAL WISDOM THAT A LAKE BREEZE SHOULD DEVELOP UNDER THE
EXPECTED PATTERN...WITH WINDS SHIFTING TO JUST SOUTH OF EAST AND
INCREASING TO ARND 10KT.
AS THE SFC TROUGH BEGINS TO MOVE EAST ACROSS THE NORTHERN PLAINS
AND TOWARD THE UPPER MISSISSIPPI VALLEY LAKE THURSDAY
NIGHT...WINDS WILL VEER TO SOUTHERLY. WARM/MOIST ADVECTION UNDER
THE SOUTHERLY FLOW WILL BRING INCREASING LOW AND MID CLOUDS AND A
CHANCE OF SHOWERS BY THE EARLY MORNING HOURS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN LAKE BREEZE WIND SHIFT TIMING AND SPEED/DIRECTION
FOLLOWING LAKE BREEZE PASSAGE.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...PERIODIC SHRA/TSRA. MVFR POSSIBLE. SOUTHWEST WINDS.
SATURDAY...CHANCE SHRA. MVFR POSSIBLE. STRONG NORTH-NORTHEAST
WINDS.
SUNDAY...VFR/WX NIL. NORTHEAST WINDS.
MONDAY...VFR/WX NIL. EAST WINDS.
TUESDAY...VFR/WX NIL. SOUTH WINDS.
KJB
&&
.MARINE...
225 PM CDT
GENERALLY LIGHT TO MODERATE SOUTHERLY FLOW EXPECTED THROUGH TOMORROW
NIGHT WITH SOUTHERLY WINDS INCREASING SOME FRIDAY IN ADVANCE OF
APPROACHING COLD FRONT. COLD FRONT WILL DROP DOWN THE LAKE FRIDAY
NIGHT WITH AN UNSEASONABLY STRONG CANADIAN HIGH BUILDING INTO THE
REGION IN ITS WAKE. A HEALTHY LATE SEASON SHOT OF CHILLY AIR ALONG
WITH THE TIGHT GRADIENT SHOULD SET THE STAGE FOR A PERIOD OF STRONG
FULL FETCH NORTH WINDS DOWN THE LAKE SATURDAY INTO SATURDAY NIGHT.
FORECAST SOUNDINGS SUGGEST THE MIXED LAYER WILL BE SHALLOW BUT DO
SHOW GALE FORCE WINDS WITHIN THE MIXED LAYER THAT SHOULD BE
TRANSPORTED TO THE SURFACE...ESPECIALLY CLOSE TO THE SHORE WHERE
WATER TEMPS ARE WARMER AND CONDITIONS LIKELY TO BE MORE UNSTABLE.
WHILE WIND AND GUST GRIDS DONT REFLECT THIS...THE STRONGEST WINDS
SHOULD OCCUR WITHIN ABOUT 5-8MI OF THE SHORE OVER SOUTHERN THIRD OF
THE LAKE. A LITTLE EARLY TO HOIST A GALE WATCH AT THIS POINT...BUT
CERTAINLY SOMETHING THAT MAY NEED TO BE CONSIDERED SOON.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1248 PM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 1016 AM CDT THU MAY 28 2015
A BAND OF CONVECTION IS RUNNING FROM NORTH OF KFNB TO KMHL IN
MISSOURI. THE THUNDERSTORMS ARE CONFINED TO THE SOUTHERN END OF
THE BAND WITH MORE RAIN ACROSS THE REST OF THE BAND.
IF TRENDS FROM THE RAP ARE CORRECT...THE BAND OF PRECIPITATION
WILL RUN INTO SLIGHTLY DRIER AIR AND DECREASING FORCING THROUGH
MID DAY. AS SUCH THE CURRENT BAND SHOULD SEE SOME DECAY TO IT AND
BEGIN ARRIVING IN THE FAR SOUTHWEST/SOUTH PRIOR TO MID AFTERNOON.
UPDATE ISSUED AT 643 AM CDT THU MAY 28 2015
HAVE EXPANDED PCPN CHCS A BIT MORE ACROSS THE SOUTHWEST AND
BROUGHT THEM IN A BIT EARLIER AS LATEST SEVERAL RUNS OF
HRRR CONSISTENT IN BRINGING SOME SHOWERS INTO SOUTHWEST CWA
TOWARD MID PM THROUGH LATE PM... AND MAY BE LATCHING ONTO
MCV WHICH IS SUGGESTED IN REGIONAL RADAR LOOP. UPDATED GRIDS/
ZFP OUT SOON.
&&
.SYNOPSIS...
ISSUED AT 320 AM CDT THU MAY 28 2015
HIGH PRESSURE IN FIRM CONTROL EARLY THIS AM BUT BEGINNING TO SHIFT
EAST TOWARD THE OHIO VLY WITH LIGHT SOUTHERLY RETURN FLOW
DEVELOPING. ACTIVE CONVECTION /SEVERAL LINEAR CLUSTERS/ FOUND
ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS EARLY THIS AM
IN VICINITY OF STATIONARY FRONTAL ZONE AND WITHIN PLUME OF
DEEPER MOISTURE AIDED BY SEVERAL MESOSCALE CONVECTIVE VORTICES.
OVER NEXT 24 HRS THE FLOW ALOFT WILL BECOME SOUTHWESTERLY AND WILL
SHUTTLE THESE DISTURBANCES NORTHEASTWARD BRINGING RAIN CHANCES
BACK TO THE AREA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT THU MAY 28 2015
TODAY... HIGH PRESSURE WILL REMAIN THE DOMINANT FEATURE WHILE
SHIFTING INTO THE OHIO VALLEY. SURFACE WINDS WILL BACK TO
SOUTHEAST AND INCREASE TO AROUND 10 TO 15+ MPH AND CONTINUE TO
DRAW IN DRIER AIR THUS CHEWING AWAY OR ERODING ANY PCPN
INITIALLY THIS AFTN...WITH JUST SLIGHT CHC OF A SHOWER OR WEAK
STORM FAR SW CWA LATE PM AHEAD OF INITIAL SHORTWAVE. OVERALL
JUST PARTLY TO MOSTLY SUNNY WITH MAINLY HIGH CLOUDS.
SOUTHEASTERLY WIND DIRECTION NOT FAVORABLE FOR MUCH WARMUP AND
PROGGED LOW LEVEL THICKNESS AND VERIFICATION OF HIGHS FROM YSTDY
ALONG WITH TRAJECTORY METHOD ALL SUPPORTIVE OF HIGHS IN RANGE
FROM 79-84 AND WITH COMFORTABLE HUMIDITY LEVELS SHOULD MAKE
FOR ANOTHER VERY FINE LATE SPRING DAY.
TONIGHT... SOUTHWEST FLOW AND SEVERAL SHORTWAVES WILL RESULT IN
DEVELOPING RAIN CHANCES. SOUTHEASTERLY FLOW THROUGH 850 MB
STILL USHERING IN DRIER AIR FROM DEPARTING HIGH AND THUS LIMITING
MOISTURE AXIS AND SUBSEQUENT BETTER PCPN CHCS TO WESTERN CWA...
ALTHOUGH SMALL PCPN CHCS EXIST EASTERN CWA LATE EVE/OVERNIGHT
WITH POTENTIAL WARM ADVECTION WING WITH VEERING LOW LEVEL JET
AHEAD OF MORE WIDESPREAD ACTIVITY LIFTING THROUGH CENTRAL IA. LOWS
GENERALLY IN RANGE FROM 59 TO 64.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 320 AM CDT THU MAY 28 2015
MAIN FORECAST CONCERN FOR THE LONG TERM ARE THE CHANCES FOR RAIN
AND THUNDER AT THE BEGINNING OF THE PERIOD. LITTLE CHANGE FROM
TODAYS FORECAST AND LAST NIGHTS FORECAST IS EXPECTED. AFTER THIS
SYSTEM MOVES THROUGH...WE SEE A QUITE REST OF THE EXTENDED
FORECAST.
FRIDAY AFTERNOON WE SHOULD BE SITTING IN THE DEEP MOISTURE. THE
LARGE...ILL DEFINED H5 WAVE WILL BE MOVING INTO THE AREA. LIKE THE
DAY SHIFT NOTED...THERE IS A LACK OF STRONG SHRTWV WITH THIS SYSTEM.
CURRENT FEELING IS THAT CONVECTION WILL BECOME MORE NUMEROUS IN THE
AFTERNOON AS THE FRONT APPROACHES THE AREA. INSOLATION WILL HELP TO
BUILD A HEALTHY AMOUNT OF CAPE FOR THUNDERSTORMS AND POSSIBLY STRONG
UPDRAFTS. WITH THE WEAK SHRTWV THERE IS A LACK OF SHEAR...IN FACT
DEEP LAYER IS SHEAR IS 20 KNOTS OR LESS. CONVECTION ON FRIDAY WILL
BE DICTATED BY COLD POOLS AND BE MULTICELL OR SINGLE CELL IN NATURE.
THEREFORE THUNDERSTORMS WILL NOT LAST LONG AND THE THREAT FOR SEVERE
WEATHER WILL BE VERY LOW. THE FLOW...AND RESIDUAL MOISTURE IN THE
AREA WILL LEAD TO HIGH PWATS. WITH THE THUNDERSTORMS AND HIGH
PWATS....LOCALIZED MINOR FLOODING COULD OCCUR. THE FRONT SHOULD MOVE
THROUGH THE AREA ON SATURDAY DAY AND WILL LEAD TO A DRY SATURDAY
EVENING.
COOLER AND DRIER AIR ARE STILL ON TAP FOR SATURDAY NIGHT AND SUNDAY.
AFTER THIS THE FLOW BECOMES MORE ZONAL...THIS WILL LEAD TO A GRADUAL
WARM UP ACROSS THE AREA. MIDWEEK WE COULD SEE RETURN MOISTURE AND
POSSIBLY AND ACTIVE WEATHER PATTERN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1245 PM CDT THU MAY 28 2015
VFR CONDITIONS WILL BE SEEN THROUGH 00Z/29 WITH HIGH AND THEN MID
LEVEL CLOUDS INCREASING ACROSS THE AREA. AFT 00Z/29 VFR CONDITIONS
ARE EXPECTED TO CONTINUE WITH ISOLATED TO SCATTERED SHRA AND
POSSIBLY A TSRA. KCID/KDBQ HAVE SLIGHTLY BETTER CHANCES OF SEEING
A PERIOD OF MVFR CONDITIONS WITH A POTENTIAL TSRA FROM 06Z/29 THROUGH
SUNRISE FRIDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...05
SHORT TERM...05
LONG TERM...GIBBS
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1022 AM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 1016 AM CDT THU MAY 28 2015
A BAND OF CONVECTION IS RUNNING FROM NORTH OF KFNB TO KMHL IN
MISSOURI. THE THUNDERSTORMS ARE CONFINED TO THE SOUTHERN END OF
THE BAND WITH MORE RAIN ACROSS THE REST OF THE BAND.
IF TRENDS FROM THE RAP ARE CORRECT...THE BAND OF PRECIPITATION
WILL RUN INTO SLIGHTLY DRIER AIR AND DECREASING FORCING THROUGH
MID DAY. AS SUCH THE CURRENT BAND SHOULD SEE SOME DECAY TO IT AND
BEGIN ARRIVING IN THE FAR SOUTHWEST/SOUTH PRIOR TO MID AFTERNOON.
UPDATE ISSUED AT 643 AM CDT THU MAY 28 2015
HAVE EXPANDED PCPN CHCS A BIT MORE ACROSS THE SOUTHWEST AND
BROUGHT THEM IN A BIT EARLIER AS LATEST SEVERAL RUNS OF
HRRR CONSISTENT IN BRINGING SOME SHOWERS INTO SOUTHWEST CWA
TOWARD MID PM THROUGH LATE PM... AND MAY BE LATCHING ONTO
MCV WHICH IS SUGGESTED IN REGIONAL RADAR LOOP. UPDATED GRIDS/
ZFP OUT SOON.
&&
.SYNOPSIS...
ISSUED AT 320 AM CDT THU MAY 28 2015
HIGH PRESSURE IN FIRM CONTROL EARLY THIS AM BUT BEGINNING TO SHIFT
EAST TOWARD THE OHIO VLY WITH LIGHT SOUTHERLY RETURN FLOW
DEVELOPING. ACTIVE CONVECTION /SEVERAL LINEAR CLUSTERS/ FOUND
ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS EARLY THIS AM
IN VICINITY OF STATIONARY FRONTAL ZONE AND WITHIN PLUME OF
DEEPER MOISTURE AIDED BY SEVERAL MESOSCALE CONVECTIVE VORTICES.
OVER NEXT 24 HRS THE FLOW ALOFT WILL BECOME SOUTHWESTERLY AND WILL
SHUTTLE THESE DISTURBANCES NORTHEASTWARD BRINGING RAIN CHANCES
BACK TO THE AREA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT THU MAY 28 2015
TODAY... HIGH PRESSURE WILL REMAIN THE DOMINANT FEATURE WHILE
SHIFTING INTO THE OHIO VALLEY. SURFACE WINDS WILL BACK TO
SOUTHEAST AND INCREASE TO AROUND 10 TO 15+ MPH AND CONTINUE TO
DRAW IN DRIER AIR THUS CHEWING AWAY OR ERODING ANY PCPN
INITIALLY THIS AFTN...WITH JUST SLIGHT CHC OF A SHOWER OR WEAK
STORM FAR SW CWA LATE PM AHEAD OF INITIAL SHORTWAVE. OVERALL
JUST PARTLY TO MOSTLY SUNNY WITH MAINLY HIGH CLOUDS.
SOUTHEASTERLY WIND DIRECTION NOT FAVORABLE FOR MUCH WARMUP AND
PROGGED LOW LEVEL THICKNESS AND VERIFICATION OF HIGHS FROM YSTDY
ALONG WITH TRAJECTORY METHOD ALL SUPPORTIVE OF HIGHS IN RANGE
FROM 79-84 AND WITH COMFORTABLE HUMIDITY LEVELS SHOULD MAKE
FOR ANOTHER VERY FINE LATE SPRING DAY.
TONIGHT... SOUTHWEST FLOW AND SEVERAL SHORTWAVES WILL RESULT IN
DEVELOPING RAIN CHANCES. SOUTHEASTERLY FLOW THROUGH 850 MB
STILL USHERING IN DRIER AIR FROM DEPARTING HIGH AND THUS LIMITING
MOISTURE AXIS AND SUBSEQUENT BETTER PCPN CHCS TO WESTERN CWA...
ALTHOUGH SMALL PCPN CHCS EXIST EASTERN CWA LATE EVE/OVERNIGHT
WITH POTENTIAL WARM ADVECTION WING WITH VEERING LOW LEVEL JET
AHEAD OF MORE WIDESPREAD ACTIVITY LIFTING THROUGH CENTRAL IA. LOWS
GENERALLY IN RANGE FROM 59 TO 64.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 320 AM CDT THU MAY 28 2015
MAIN FORECAST CONCERN FOR THE LONG TERM ARE THE CHANCES FOR RAIN
AND THUNDER AT THE BEGINNING OF THE PERIOD. LITTLE CHANGE FROM
TODAYS FORECAST AND LAST NIGHTS FORECAST IS EXPECTED. AFTER THIS
SYSTEM MOVES THROUGH...WE SEE A QUITE REST OF THE EXTENDED
FORECAST.
FRIDAY AFTERNOON WE SHOULD BE SITTING IN THE DEEP MOISTURE. THE
LARGE...ILL DEFINED H5 WAVE WILL BE MOVING INTO THE AREA. LIKE THE
DAY SHIFT NOTED...THERE IS A LACK OF STRONG SHRTWV WITH THIS SYSTEM.
CURRENT FEELING IS THAT CONVECTION WILL BECOME MORE NUMEROUS IN THE
AFTERNOON AS THE FRONT APPROACHES THE AREA. INSOLATION WILL HELP TO
BUILD A HEALTHY AMOUNT OF CAPE FOR THUNDERSTORMS AND POSSIBLY STRONG
UPDRAFTS. WITH THE WEAK SHRTWV THERE IS A LACK OF SHEAR...IN FACT
DEEP LAYER IS SHEAR IS 20 KNOTS OR LESS. CONVECTION ON FRIDAY WILL
BE DICTATED BY COLD POOLS AND BE MULTICELL OR SINGLE CELL IN NATURE.
THEREFORE THUNDERSTORMS WILL NOT LAST LONG AND THE THREAT FOR SEVERE
WEATHER WILL BE VERY LOW. THE FLOW...AND RESIDUAL MOISTURE IN THE
AREA WILL LEAD TO HIGH PWATS. WITH THE THUNDERSTORMS AND HIGH
PWATS....LOCALIZED MINOR FLOODING COULD OCCUR. THE FRONT SHOULD MOVE
THROUGH THE AREA ON SATURDAY DAY AND WILL LEAD TO A DRY SATURDAY
EVENING.
COOLER AND DRIER AIR ARE STILL ON TAP FOR SATURDAY NIGHT AND SUNDAY.
AFTER THIS THE FLOW BECOMES MORE ZONAL...THIS WILL LEAD TO A GRADUAL
WARM UP ACROSS THE AREA. MIDWEEK WE COULD SEE RETURN MOISTURE AND
POSSIBLY AND ACTIVE WEATHER PATTERN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 643 AM CDT THU MAY 28 2015
VFR CONDITIONS GENERALLY EXPECTED THROUGH THE TAF CYCLE. A DISTURBANCE
LIFTING NORTHEAST FROM KS WILL BRING A CHANCE OF SHOWERS TO THE AREA
FROM SOUTHWEST TO NORTHEAST BY MID PM THROUGH EARLY EVENING. THEN
EXPECT BULK OF ANY ADDITIONAL RAIN CHANCES LATER TONIGHT TO FOCUS
MAINLY FROM CENTRAL INTO NORTHEAST IA WITH VEERING LOW LEVEL JET AND
A SECONDARY DISTURBANCE... ALTHOUGH ISOLD SHOWER OR STORM IS POSSIBLE
ELSEWHERE. SOUTHEAST WINDS WILL INCREASE 10 TO 15 KTS WITH SOME
GUSTS NEAR 20 KTS POSSIBLE ON OCCASION THIS AFTN. WINDS TONIGHT WILL
DIMINISH BELOW 10 KTS FROM THE SOUTHEAST AND SOUTH.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...05
SHORT TERM...05
LONG TERM...GIBBS
AVIATION...05
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
655 PM CDT FRI MAY 29 2015
...UPDATED FOR AVIATION DISCUSSION...
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 1200 PM CDT FRI MAY 29 2015
TONIGHT:
MUCH MORE TRANQUIL SENSIBLE WEATHER IS EXPECTED FOR THIS EVENING COMPARED
TO THE LAST TWO EVENINGS. THERE WILL STILL BE A CHANCE FOR THUNDERSTORMS,
BUT THIS ACTIVITY SHOULD BE MUCH MORE LIMITED IN TERMS OF COVERAGE AND
INTENSITY. FOLLOWED A BLEND OF HRRR AND ARW GUIDANCE, WHICH SHOWS CONVECTION
MOVING ACROSS OUR NORTHERN ZONES. THERE MIGHT BE ANOTHER SHOT AT CONVECTION
TOWARDS 06Z ACROSS SOUTH-CENTRAL KANSAS AS DESCRIBED BY THE NAM. CONFIDENCE
IS LOWER IN THIS SOLUTION AS DRY AIR ADVECTS IN AND INSTABILITY BECOMES
MEDIOCRE TO NON-EXISTENT. SEVERE WEATHER IS NOT EXPECTED AS SHEAR AND
CAPE IS MARGINAL. THERE COULD BE SOME MARGINAL STORMS, BUT THAT IS ABOUT
IT. LOWS WILL BE A LITTLE BIT COOLER (UPPER 40S TO LOWER 50S) AS DRIER
AIR/LOW DEWPOINTS ADVECT IN AS ALREADY MENTIONED ABOVE.
TOMORROW:
A PRECIPITATION-FREE FORECAST IS EXPECTED TOMORROW WITH POPS AT ZERO
PERCENT. HIGHS WILL BE COOLER UNDER THE 11-16C 850-HPA AIR MASS. EXPECTING
VALUES IN THE 68-71F RANGE. WINDS WILL SLOWLY VEER AROUND TO THE EAST
BY DUSK.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 PM CDT FRI MAY 29 2015
SOUTHWEST KANSAS WILL BE IN A QUIETER PERIOD WEATHER-WISE DURING
THE FIRST FIRST FEW DAYS OF THE EXTENDED PERIOD. BY SATURDAY
NIGHT, THE UPPER LEVEL TROUGH CURRENTLY OVER THE NORTHERN AND
CENTRAL PLAINS WILL HAVE MOVED EAST INTO THE GREAT LAKES AND
MISSISSIPPI VALLEY. FARTHER WEST, UPPER LEVEL RIDGING WILL BE
BUILDING EAST ACROSS THE NORTHERN AND CENTRAL ROCKIES INTO THE
ADJACENT HIGH PLAINS. SURFACE HIGH PRESSURE WILL BE EXTENDING FROM
THE MIDWEST INTO THE CENTRAL AND SOUTHERN PLAINS. THE COOL HIGH
PRESSURE WILL RESULT IN OVERNIGHT LOWS SUNDAY MORNING IN THE MID
40S TO LOW 50S. INCREASING WESTERLY FLOW ACROSS THE NORTHERN INTO
THE CENTRAL PLAINS WILL INDUCE LEE SIDE TROUGHING ALONG THE
EASTERN SLOPES OF THE NORTHERN AND CENTRAL ROCKIES. EAST OF THE
TROUGH, A STRENGTHENING PRESSURE GRADIENT WILL BRING INCREASING
SOUTHERLY WINDS TO WESTERN KANSAS ALONG WITH SOME MODEST LOW LEVEL
MOISTURE RETURN.
BY LATE SUNDAY THROUGH LATE MONDAY, A FEW OF THE MEDIUM RANGE MODELS
HINT AT SOME THUNDERSTORM POTENTIAL SOMEWHERE ACROSS THE HIGH
PLAINS GIVEN THE MOISTURE RETURN AND INCREASE IN LOW LEVEL WARM
MOIST ADVECTION. THIS TYPE OF PATTERN HOLDS TROUGH MID WEEK. LOW
LEVEL MOISTURE WILL BE INCREASING WITH TIME. THERE WILL BE
INCREASING CHANCES FOR EVENING AND NIGHTTIME MCS DEVELOPMENT
ACROSS THE CENTRAL HIGH PLAINS AS THE LOW LEVEL JET HELPS FOCUS
THUNDERSTORM DEVELOPMENT. BETTER CHANCES FOR MCS DEVELOPMENT MAY
BE FOCUSED MORE OVER NEBRASKA AND POSSIBLY NORTHERN KANSAS WHERE
THE NOSE OF THE LOW LEVEL JET WILL BE LOCATED. THE ATMOSPHERE MAY
REMAIN BETTER CAPPED FARTHER SOUTH ACROSS WESTERN KANSAS, KEEPING
THUNDERSTORMS MORE ISOLATED.
TOWARD NEXT WEEKEND, THE MODELS SHOW AN UPPER LEVEL TROUGH
REDEVELOPING OVER THE WESTERN CONUS WITH UPPER FLOW TURNING MORE
SOUTHWESTERLY OVER THE CENTRAL HIGH PLAINS. THE ECMWF IS MORE
AMPLIFIED WITH THIS PATTERN THAN THE GFS BUT EITHER WAY, THIS
PATTERN COULD BRING INCREASING CHANCES FOR THUNDERSTORMS AND
HEAVY RAIN ACROSS WESTERN KANSAS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 653 PM CDT FRI MAY 29 2015
A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE THROUGH 02Z AS AN
UPPER LEVEL TROUGH APPROACHES; BUT THESE SHOULD WEAKEN WITH THE
LOSS OF DAYTIME HEATING. WINDS WILL INCREASE TO 10-15 KTS FROM THE
NORTH BEHIND A COLD FRONT BETWEEN 02 AND 04Z AND THEN LEVEL OFF
AROUND 10 KTS TOWARD MORNING. MVFR CIGS WILL DEVELOP BEHIND A COLD
FRONT BETWEEN 03 AND 05Z AND THEN BECOME VFR WITH DAYTIME HEATING BY
16Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 53 70 48 77 / 20 0 0 0
GCK 51 69 49 79 / 20 0 0 0
EHA 51 70 52 83 / 10 0 0 0
LBL 52 71 50 80 / 20 0 0 0
HYS 52 69 46 77 / 20 0 0 0
P28 55 71 49 77 / 30 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1230 PM CDT Thu May 28 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 353 AM CDT THU MAY 28 2015
Convective complex that began over western Kansas this afternoon had
recent central portions of the state early this morning. System is
making decent eastward progress and duration of heavy and then
lighter precip are not long, helping keep heavy amounts in check.
Precip will likely be waning in next few hours and expect the Flash
Flood Watch to expire, if not be cancelled early. Another somewhat
stationary complex has taken shape over southwest Kansas over the
past few hours, perhaps from gravity wave from MCS to its south.
Even the rapidly updating models are struggling with these smaller
scale systems, leading to a rather low confidence forecast.
West-southwest flow remains aloft with at least three shortwave
troughs over the western states evident on water vapor imagery.
HRRR and RAP continue to be slow with the current complex in the
CWA, and seem to attempt to congeal the SW KS system into the current
one over the next several hours. Going with radar trends, expect a
decreasing trend in the west with eastern areas seeing the current
bands move through early this morning. A general downtrend in
activity is then expected into the afternoon with next better chance
for convection coming in the late evening and overnight as the upper
wave over Utah early this morning swings through. With persistent
but modest warm air advection into the region and outflow
boundaries, gravity waves, and other mesoscale forcing mechanisms
likely passing through, at least small precip chances exist
throughout the day and night. Elevated instability tonight looks
somewhat greater than today with a similar though more veered low
level jet. Along with PW values around 1.5", will again need to
watch for heavy rains, but confidence is too low to support a Flash
Flood Watch with wide spread in where and even if precip will occur.
.LONG TERM...(Friday through Wednesday)
Issued at 353 AM CDT THU MAY 28 2015
By Friday morning the main mid/upper level trough stretches from
eastern WY up to MN, while several shortwaves swing over the central
and southern plains. These waves will likely dictate where showers
and storms develop and or track during the day Friday. A cold front
will then approach the area from the west bringing higher dew points
in from the south. Both the NAM and GFS are suggesting dew points
reach the mid to upper 60s with a few 70s possible. Decent lapse
rates in the southwest flow aloft yield cape on the order of
2500-3500 j/kg with little inhibition. The deep layer shear is
around 20 kts, and the vertical profile seems mostly unidirectional.
Given this type of environment both ahead and along the front do not
expect any supercells. If any of these waves or MCSs pass over
during the morning hours than subsidence could inhibit diurnal
development. The cold front should begin to slide through beginning
Friday evening and during the overnight. Showers and storms are
possible along the front, but the instability should be on the
decrease and shear remains low. So again do not expect any well
organized severe storms overnight. Also, the models are not in good
agreement on the 0-3 km bulk shear magnitudes and directions, so not
sure if there will be any organized wind threat. Although, given the
cape there is a marginal risk for hail during the afternoon and
evening hours.
The front should clear the area by 12Z Saturday, but the problem is
the mid level trough is still back over central KS and eastern NE.
The trough is forecast to progress eastward during the day Saturday.
This along with 925 mb frontogenesis could provide enough lift
within some residual low level moisture for light post frontal
precip. Confidence in these precip chances are not high therefore
kept the area mostly under slight pops. Cooler and drier air moves
in on Sunday as an upper level ridge builds across the southern
Rockies. The models have now kept the energy that moves over
Saturday closed off over the southern MS valley preventing the ridge
from building too far north. Meanwhile more mid level troughing
moves over the Pacific northwest and northern Rockies by mid week.
Southwest flow aloft will soon follow as more shortwaves begin to
drive the weather.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1229 PM CDT THU MAY 28 2015
Rain is currently moving NE toward TOP/FOE. Expect to see some on
and off again -RA at these terminals for the next couple hours
before this system moves east of the area. Storms are firing up
near MHK, so have mentioned VCTS until 21Z before clearing. A
period of VFR is expected from this afternoon until early morning
tomorrow before another system moves through from the west.
Confidence in the timing and exact evolution of this system are low
right now. Have VCTS starting at MHK at 10Z, with TOP/FOE seeing
VCTS at 12Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...Sanders
AVIATION...Heller
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1202 PM CDT THU MAY 28 2015
...UPDATED SHORT AND AVIATION...
.SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY)
ISSUED AT 1200 PM CDT THU MAY 28 2015
TONIGHT:
ANOTHER BOUT OF SEVERE THUNDERSTORMS IS LIKELY. THERE IS PLENTY OF
INSTABILITY WITH 3000 J/KG OF SBCAPE. BULK SHEAR IS WEAKER TODAY
AND IS VERY MARGINAL FOR SUPERCELLS (30 KT). UPPER LEVEL WINDS ARE
WEAKER TOO FOR STORM TOP VENTILATION. LIKE THE NSSL WRF SOLUTION AS
FAR AS CONVECTIVE EVOLUTION IS CONCERNED. RECENT HRRR RUNS HAVE TRENDED
TO A SIMILAR SOLUTION AS DESCRIBED BY THE WRF. THE NET RESULT IS CONVECTION
WILL FORM ACROSS THE WESTERN ZONES THIS AFTERNOON. THINK UPSCALE GROWTH
IN TO A LINE IS LIKELY DOWNSTREAM. TORNADO POTENTIAL LOOKS LESS LIKELY
TODAY AS SUPERCELLS LOOK LESS LIKELY. I SUPPOSE AN ISOLATED TORNADO
CANNOT BE RULED OUT, HOWEVER. THE MAIN THREATS WILL BE HEAVY RAIN AS
PWATS REMAIN VERY HIGH. THE OVERALL PROGRESSIVE NATURE OF THE EXPECTED
LINE SHOULD LIMIT SOME TRAINING OF STORMS AS THE LINE HEADS EAST. STILL,
ANOTHER 1 TO 2" OF RAIN LOOK GOOD FOR SOME SPOTS. FARTHER EAST, THE
EASTERN ZONES WILL SEE LESS RAINFALL AS THE LINE WILL PROBABLY WEAKEN
LATE TONIGHT. WET MICROBURSTS OF 60 MPH WILL ALSO BE POSSIBLE WITH THE
LINE. LOWS WILL BE IN THE UPPER 50S TO LOWER 60S.
TOMORROW:
CONVECTION WILL BE POSSIBLE AGAIN ACROSS THE WESTERN ZONES AND EXTENDING
EASTWARD. HAVE CHANCE POPS IN THERE NOW. CONFIDENCE IS NOT GREAT, BUT
THE MESOSCALE MODELS ARE BREAKING OUT STORMS. SEVERE WEATHER IS UNLIKELY
AS SHEAR IS WEAK AND INSTABILITY WILL ALSO BE WEAK. HIGHS WILL BE IN
THE 70S AND 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1145 AM CDT THU MAY 28 2015
COOLER WEATHER CAN BE EXPECTED SATURDAY AND SATURDAY NIGHT IN THE
WAKE OF A COLD FRONT. HIGHS SATURDAY SHOULD ONLY REACH NEAR 70,
WITH LOWS IN THE LOWER 50S BY SUNDAY MORNING. WEAK UPPER LEVEL
RIDGING WILL DEVELOP OVER THE PLAINS BY LATE SUNDAY, ALONG WITH
LEE TROUGHING, SOUTHERLY WINDS AND A WARMING TREND THROUGH MID
WEEK. HIGH TEMPERATURES OUGHT TO WARM INTO THE LOWER 80S BY
MONDAY, WITH SOME MID 80S ALONG THE COLORADO BORDER. HIGH
TEMPERATURES SHOULD PERSIST IN THE MID 80S THROUGH THE WEEK AND
ALL OF THE RAIN WE HAVE HAD THIS SPRING WILL DISCOURAGE
TEMPERATURES FROM REACHING INTO THE 90S DUE TO ENHANCED
EVAPOTRANSPIRATION. MODERATE SURFACE BASED CAPE VALUES WILL
DEVELOP AS EARLY AS SUNDAY AND PERSIST EVERY AFTERNOON AND EVENING
ALONG THE WESTERN HIGH PLAINS AND INTO FAR WESTERN KANSAS. WITH
THE LACK OF UPPER LEVEL SUPPORT, ONLY ISOLATED, MARGINALLY SEVERE
THUNDERSTORMS ARE EXPECTED AND SOME OF THESE COULD VENTURE INTO
FAR WESTERN KANSAS. THUNDERSTORM CHANCES WILL INCREASE A LITTLE BY
WEDNESDAY AND THURSDAY AS AN UPPER LEVEL TROUGH DEVELOPS ACROSS
THE WESTERN UNITED STATES, ALONG WITH A SHARPER LEE TROUGH AND
STRONGER LOW LEVEL CONVERGENCE. DEWPOINTS WILL BE FAIRLY HIGH,
ESPECIALLY GIVEN ALL THE ANTECEDENT RAINFALL AND
EVAPOTRANSPIRATION SO THAT SURFACE BASED CAPE WILL BE FAIRLY HIGH.
HOWEVER, GIVEN THAT THE UPPER LEVEL JET WILL BE FAR TO THE NORTH,
TORNADIC ACTIVITY AND GIANT HAIL ARE NOT LIKELY THROUGH MID WEEK
AND POSSIBLY THROUGH THURSDAY OR EVEN FRIDAY. HOWEVER, IF THE
UPPER LEVEL WINDS INCREASE LATE NEXT WEEK, THEN SEVERE
THUNDERSTORM CHANCES WILL INCREASE ACCORDINGLY. TEMPERATURES WILL
REMAIN ON THE WARM SIDE THROUGH FRIDAY WITH HIGHS MAINLY IN THE
80S. GIVEN THE LEE TROUGHING AND HIGH DEWPOINTS, LOWS WILL BE WARM
IN THE 60S ACROSS CENTRAL AND SOUTH CENTRAL KANSAS WITH ONLY
SLIGHTLY COOLER READINGS ALONG THE COLORADO BORDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1200 PM CDT THU MAY 28 2015
VFR CIGS SHOULD PREVAIL THROUGH THE TAF PD. THERE WILL BE ANOTHER ROUND
OF TSRA AND LIKELY +TSRA THIS EVENING IN BETWEEN 22Z-02Z. THIS, HOWEVER,
WILL NOT BE THE PREVAILING FLIGHT CONDITION AS A PROGRESSIVE THUNDERSTORM
LINE WILL QUICKLY MOVE ACROSS THE TERMINALS DURING THIS TIME FRAME.
AS A RESULT, WILL RETAIN WITH TSRA/CB GROUPS DURING THE EVENING. THUNDERSTORMS
ARE LESS LIKELY AFTER 03Z AS SUBSIDENCE DEVELOPS. WINDS WILL BE LIGHT
AND VARIABLE TODAY AND THEN SOUTHERLY 5-15 KT TONIGHT WITH VEERING NW
BY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 81 60 79 54 / 50 70 40 40
GCK 83 57 78 53 / 60 70 40 40
EHA 82 55 77 53 / 50 50 40 50
LBL 82 58 78 55 / 60 60 40 40
HYS 79 59 78 53 / 40 50 40 40
P28 80 63 80 58 / 80 50 40 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KSZ065-066-078>081-
088>090.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...FINCH
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
642 AM CDT Thu May 28 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 353 AM CDT THU MAY 28 2015
Convective complex that began over western Kansas this afternoon had
recent central portions of the state early this morning. System is
making decent eastward progress and duration of heavy and then
lighter precip are not long, helping keep heavy amounts in check.
Precip will likely be waning in next few hours and expect the Flash
Flood Watch to expire, if not be cancelled early. Another somewhat
stationary complex has taken shape over southwest Kansas over the
past few hours, perhaps from gravity wave from MCS to its south.
Even the rapidly updating models are struggling with these smaller
scale systems, leading to a rather low confidence forecast.
West-southwest flow remains aloft with at least three shortwave
troughs over the western states evident on water vapor imagery.
HRRR and RAP continue to be slow with the current complex in the
CWA, and seem to attempt to congeal the SW KS system into the current
one over the next several hours. Going with radar trends, expect a
decreasing trend in the west with eastern areas seeing the current
bands move through early this morning. A general downtrend in
activity is then expected into the afternoon with next better chance
for convection coming in the late evening and overnight as the upper
wave over Utah early this morning swings through. With persistent
but modest warm air advection into the region and outflow
boundaries, gravity waves, and other mesoscale forcing mechanisms
likely passing through, at least small precip chances exist
throughout the day and night. Elevated instability tonight looks
somewhat greater than today with a similar though more veered low
level jet. Along with PW values around 1.5", will again need to
watch for heavy rains, but confidence is too low to support a Flash
Flood Watch with wide spread in where and even if precip will occur.
.LONG TERM...(Friday through Wednesday)
Issued at 353 AM CDT THU MAY 28 2015
By Friday morning the main mid/upper level trough stretches from
eastern WY up to MN, while several shortwaves swing over the central
and southern plains. These waves will likely dictate where showers
and storms develop and or track during the day Friday. A cold front
will then approach the area from the west bringing higher dew points
in from the south. Both the NAM and GFS are suggesting dew points
reach the mid to upper 60s with a few 70s possible. Decent lapse
rates in the southwest flow aloft yield cape on the order of
2500-3500 j/kg with little inhibition. The deep layer shear is
around 20 kts, and the vertical profile seems mostly unidirectional.
Given this type of environment both ahead and along the front do not
expect any supercells. If any of these waves or MCSs pass over
during the morning hours than subsidence could inhibit diurnal
development. The cold front should begin to slide through beginning
Friday evening and during the overnight. Showers and storms are
possible along the front, but the instability should be on the
decrease and shear remains low. So again do not expect any well
organized severe storms overnight. Also, the models are not in good
agreement on the 0-3 km bulk shear magnitudes and directions, so not
sure if there will be any organized wind threat. Although, given the
cape there is a marginal risk for hail during the afternoon and
evening hours.
The front should clear the area by 12Z Saturday, but the problem is
the mid level trough is still back over central KS and eastern NE.
The trough is forecast to progress eastward during the day Saturday.
This along with 925 mb frontogenesis could provide enough lift
within some residual low level moisture for light post frontal
precip. Confidence in these precip chances are not high therefore
kept the area mostly under slight pops. Cooler and drier air moves
in on Sunday as an upper level ridge builds across the southern
Rockies. The models have now kept the energy that moves over
Saturday closed off over the southern MS valley preventing the ridge
from building too far north. Meanwhile more mid level troughing
moves over the Pacific northwest and northern Rockies by mid week.
Southwest flow aloft will soon follow as more shortwaves begin to
drive the weather.
&&
.AVIATION...(For the 12Z TAFs through 12Z Friday Morning)
Issued at 641 AM CDT THU MAY 28 2015
Precipitation should slowly subside over the next few-several
hours with wave pushing off to the ENE. Next best chance for
convection comes after 03Z with another complex of TSRA possibly
moving through from the west. Will maintain VCTS only at this
point given continued uncertainty.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH until 7 AM CDT this morning FOR KSZ008-009-
020>022-034>037.
&&
$$
SHORT TERM...65
LONG TERM...Sanders
AVIATION...65
AREA FORECAST DISCUSSION
NWS TOPEKA KS
356 AM CDT Thu May 28 2015
.SHORT TERM...(Today and Tonight)
Issued at 353 AM CDT THU MAY 28 2015
Convective complex that began over western Kansas this afternoon had
recent central portions of the state early this morning. System is
making decent eastward progress and duration of heavy and then
lighter precip are not long, helping keep heavy amounts in check.
Precip will likely be waning in next few hours and expect the Flash
Flood Watch to expire, if not be cancelled early. Another somewhat
stationary complex has taken shape over southwest Kansas over the
past few hours, perhaps from gravity wave from MCS to its south.
Even the rapidly updating models are struggling with these smaller
scale systems, leading to a rather low confidence forecast.
West-southwest flow remains aloft with at least three shortwave
troughs over the western states evident on water vapor imagery.
HRRR and RAP continue to be slow with the current complex in the
CWA, and seem to attempt to congeal the SW KS system into the current
one over the next several hours. Going with radar trends, expect a
decreasing trend in the west with eastern areas seeing the current
bands move through early this morning. A general downtrend in
activity is then expected into the afternoon with next better chance
for convection coming in the late evening and overnight as the upper
wave over Utah early this morning swings through. With persistent
but modest warm air advection into the region and outflow
boundaries, gravity waves, and other mesoscale forcing mechanisms
likely passing through, at least small precip chances exist
throughout the day and night. Elevated instability tonight looks
somewhat greater than today with a similar though more veered low
level jet. Along with PW values around 1.5", will again need to
watch for heavy rains, but confidence is too low to support a Flash
Flood Watch with wide spread in where and even if precip will occur.
.LONG TERM...(Friday through Wednesday)
Issued at 353 AM CDT THU MAY 28 2015
By Friday morning the main mid/upper level trough stretches from
eastern WY up to MN, while several shortwaves swing over the central
and southern plains. These waves will likely dictate where showers
and storms develop and or track during the day Friday. A cold front
will then approach the area from the west bringing higher dew points
in from the south. Both the NAM and GFS are suggesting dew points
reach the mid to upper 60s with a few 70s possible. Decent lapse
rates in the southwest flow aloft yield cape on the order of
2500-3500 j/kg with little inhibition. The deep layer shear is
around 20 kts, and the vertical profile seems mostly unidirectional.
Given this type of environment both ahead and along the front do not
expect any supercells. If any of these waves or MCSs pass over
during the morning hours than subsidence could inhibit diurnal
development. The cold front should begin to slide through beginning
Friday evening and during the overnight. Showers and storms are
possible along the front, but the instability should be on the
decrease and shear remains low. So again do not expect any well
organized severe storms overnight. Also, the models are not in good
agreement on the 0-3 km bulk shear magnitudes and directions, so not
sure if there will be any organized wind threat. Although, given the
cape there is a marginal risk for hail during the afternoon and
evening hours.
The front should clear the area by 12Z Saturday, but the problem is
the mid level trough is still back over central KS and eastern NE.
The trough is forecast to progress eastward during the day Saturday.
This along with 925 mb frontogenesis could provide enough lift
within some residual low level moisture for light post frontal
precip. Confidence in these precip chances are not high therefore
kept the area mostly under slight pops. Cooler and drier air moves
in on Sunday as an upper level ridge builds across the southern
Rockies. The models have now kept the energy that moves over
Saturday closed off over the southern MS valley preventing the ridge
from building too far north. Meanwhile more mid level troughing
moves over the Pacific northwest and northern Rockies by mid week.
Southwest flow aloft will soon follow as more shortwaves begin to
drive the weather.
&&
.AVIATION...(For the 06Z TAFs through 06Z Thursday Night)
Issued at 1143 PM CDT WED MAY 27 2015
Confidence in timing precip at the terminals remains low as models
show varying solutions. In general have gone with the idea that
after the initial convection slowly moves in, storms could fall
apart mid to late morning with the weakening of the low level jet
and initial vort max passing northeast. Then there may be another
chance for scattered TS during the peak heating of the day.
Continued with VFR CIGS, but feel like MVFR VSBY will occur with
the precip. If intensity remains high, IFR VSBY could occur, but
instability is weaker across northeast KS so I expect an overall
weakening trend as storms move northeast.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH until 7 AM CDT this morning FOR KSZ008-009-
020>022-034>037.
&&
$$
SHORT TERM...65
LONG TERM...Sanders
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
225 AM MDT THU MAY 28 2015
.UPDATE...
ISSUED AT 1022 PM MDT WED MAY 27 2015
DECIDED TO ISSUE A FLASH FLOOD WATCH FOR PORTIONS OF THE REGION
THIS EVENING. BASICALLY CHOSE TO OUTLINE THE LOCATIONS MOST
SUSCEPTIBLE TO FLASH FLOODING TOMORROW WHICH IS BASICALLY THE SAME
LOCATIONS THAT RECEIVED HEAVY RAIN TODAY AND IN THE VICINITY OF
THE DRYLINE. REASONING IS MANY LOCATIONS RECEIVED HEAVY RAIN WITH
REPORTS OF FLASH FLOODING...PARTICULARLY IN SOUTHWEST NEBRASKA.
THUNDERSTORMS ARE ONCE AGAIN EXPECTED TO DEVELOP TOMORROW WITH
ANEMIC FORWARD SPEEDS AND PRECIPITABLE WATER READINGS WELL ABOVE
NORMAL.
AMENDED FORECAST FOR LATEST TRENDS IN POPS...FOG/STRATUS EXPECTED
TONIGHT AND STORM CHANCES TOMORROW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 301 PM MDT WED MAY 27 2015
NOT A LOT OF TIME TO WRITE DUE TO ONGOING SEVERE WEATHER. MODELS
HAVING A HARD TIME WITH THE CONVECTION. RUC WOULD LOOK TO HAVE THE
RIGHT IDEA WITH THE MAIN CLUSTER OF CONVECTION OVER THE SOUTHEAST
PORTION OF THE AREA. TWO DIFFERENT AREAS OF SURFACE
CONVERGENCE...ONE RUNNING FROM SOUTH TO NORTH ACROSS THE CENTER OF
THE AREA AND ANOTHER AREA APPROACHING THE NORTHWEST CORNER. WEAK
SHORTWAVE TROUGH SHOULD TRANSITIONING ACROSS THE AREA THROUGH THE
EVENING. SO STORMS LOOK TO GRADUALLY END FROM WEST TO EAST DURING
THE NIGHT.
INDICATIONS ARE THAT WILL DEFINITELY HAVE STRATUS MOVE ACROSS THE
AREA BEHIND THE RAIN WITH SOME PATCHY FOG POSSIBLE. HAVE THIS LAST
THROUGH MID MORNING. BY THE MIDDLE OF THE DAY...SURFACE BOUNDARY
SETS UP JUST EAST OF THE KANSAS AND COLORADO BORDER. MID AND UPPER
LEVEL LIFT LOOKS TO BE STRONGER THAN TODAY SO AGAIN LOOK TO HAVE
ANOTHER GOOD CHANCE OF STORMS...SOME SEVERE...IN THE AFTERNOON.
DUE TO LACK OF TIME DID NOT CHANGE THE TEMPERATURES THROUGH
TOMORROW TOO MUCH. IT DOES LOOK WARMER TOMORROW.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 225 AM MDT THU MAY 28 2015
AN UPPER LEVEL RIDGE WILL BE POSITIONED OVER THE WESTERN THIRD OF
THE CONUS ON SUNDAY...AND THE AREA OF STABLE WEATHER WILL BUILD INTO
THE CENTRAL PLAINS ON MONDAY. AS A RESULT...WARM TEMPERATURES IN
THE UPPER 70S TO LOWER 80S AND DRY WEATHER WILL BE PRESENT ACROSS
THE TRI STATE AREA.
THE UPPER RIDGE WILL BEGIN TO DEGRADE MONDAY NIGHT AND TUESDAY
MORNING AS THE FEATURE LESSENS IN AMPLITUDE AND AREAL EXTENT WITH
THE NEXT WEATHER MAKING UPPER TROUGH MOVES INTO THE PACIFIC
NORTHWEST. ECMWF/GFS/CANADIAN/DGEX MODELS ALL GENERALLY AGREE WITH
HEIGHT FALL POSITIONS ACROSS THE COLORADO FRONT RANGE TUESDAY
AFTERNOON AND EVENING WITH A VERY SUBTLE SHORTWAVE TROUGH PATTER
EMBEDDED WITHIN THE MAIN FLOW. THIS MID LEVEL TROUGH COULD SPARK
SOME AFTERNOON SHOWERS AND THUNDERSTORMS...MAINLY FOR EASTERN
COLORADO. THE MID LEVEL TROUGH WILL DEEPEN TUESDAY EVENING AND
OVERNIGHT...WHICH WILL BRING INCREASED CHANCES FOR SHOWERS AND
THUNDERSTORMS FOR MUCH OF THE TRI STATE AREA. PLENTY OF CAPE IN
MODEL SOUNDINGS BETWEEN 2000 AND 3000 J/KG COULD POTENTIALLY MEAN
SEVERE THUNDERSTORMS...HOWEVER THERE IS A LACK OF STRONG JET SUPPORT
AT THE MID OR LOWER LEVELS...SO BULK SHEAR LACKS AT THE MOMENT. DRY
AIR IN THE MID LEVELS COULD ALSO POTENTIALLY BRING SEVERE WIND GUSTS
AREA WIDE.
THE UPPER TROUGH WILL THEN BEGIN TO TAKE A NEGATIVE TILT ON
WEDNESDAY ACROSS THE CENTRAL HIGH PLAINS REGION...WHICH IN TURN WILL
BRING STEEP LAPSE RATES ALOFT AND CAPE VALUES BETWEEN 2000 AND 3000
J/KG ACROSS THE FORECAST AREA FOR THE AFTERNOON AND EVENING HOURS.
DRY AIR IN THE MID LEVELS WILL ALSO MAKE SEVERE WIND GUSTS POSSIBLE.
SIMILAR TO TUESDAY...LACK OF A STRONG JET WILL LEAVE STRONG SHEAR
VALUES ABSENT. HOWEVER...SEVERE THUNDERSTORMS WILL STILL BE POSSIBLE
FOR MANY LOCATIONS PROVIDE CURRENT MODEL FORECASTS HOLD TOGETHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM MDT WED MAY 27 2015
SEVERAL AVIATION CONCERNS ANTICIPATED THIS FORECAST. FIRST...LOW
LEVEL JET HAS STRENGTHENED OVER KGLD. HOWEVER...STRONGER WINDS AT
THE SURFACE THROUGHOUT THE NIGHT MAY PREVENT LLWS DEVELOPMENT.
SECOND...FOG/STRATUS IS LIKELY BY MORNING AT BOTH SITES. FEEL
CONDITIONS MAY BE WORSE AT KGLD WHERE THERE IS MORE OF AN
OPPORTUNITY FOR CLEARING OF THUNDERSTORM ANVIL MATTER. THIRD...A
STRONG DISTURBANCE MOVES THROUGH TOMORROW AFTERNOON WITH
WIDESPREAD THUNDERSTORM INITIATION ALONG THE DRYLINE. BOTH SITES
HAVE A HIGH CHANCE FOR STORMS SO WENT AHEAD WITH A TEMPO GROUP AS
TIMING REMAINS A LITTLE SUSPECT DUE TO POTENTIAL EARLIER
DEVELOPMENT AND ANEMIC STORM MOVEMENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH FROM NOON MDT /1 PM CDT/ TODAY THROUGH THIS
EVENING FOR KSZ001-002-013>015-028-029-042.
CO...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THIS EVENING FOR
COZ090.
NE...FLASH FLOOD WATCH FROM NOON MDT /1 PM CDT/ TODAY THROUGH THIS
EVENING FOR NEZ079-080.
&&
$$
UPDATE...RRH
SHORT TERM...BULLER
LONG TERM...MK
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1144 PM MDT WED MAY 27 2015
.UPDATE...
ISSUED AT 1022 PM MDT WED MAY 27 2015
DECIDED TO ISSUE A FLASH FLOOD WATCH FOR PORTIONS OF THE REGION
THIS EVENING. BASICALLY CHOSE TO OUTLINE THE LOCATIONS MOST
SUSCEPTIBLE TO FLASH FLOODING TOMORROW WHICH IS BASICALLY THE SAME
LOCATIONS THAT RECEIVED HEAVY RAIN TODAY AND IN THE VICINITY OF
THE DRYLINE. REASONING IS MANY LOCATIONS RECEIVED HEAVY RAIN WITH
REPORTS OF FLASH FLOODING...PARTICULARLY IN SOUTHWEST NEBRASKA.
THUNDERSTORMS ARE ONCE AGAIN EXPECTED TO DEVELOP TOMORROW WITH
ANEMIC FORWARD SPEEDS AND PRECIPITABLE WATER READINGS WELL ABOVE
NORMAL.
AMENDED FORECAST FOR LATEST TRENDS IN POPS...FOG/STRATUS EXPECTED
TONIGHT AND STORM CHANCES TOMORROW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 301 PM MDT WED MAY 27 2015
NOT A LOT OF TIME TO WRITE DUE TO ONGOING SEVERE WEATHER. MODELS
HAVING A HARD TIME WITH THE CONVECTION. RUC WOULD LOOK TO HAVE THE
RIGHT IDEA WITH THE MAIN CLUSTER OF CONVECTION OVER THE SOUTHEAST
PORTION OF THE AREA. TWO DIFFERENT AREAS OF SURFACE
CONVERGENCE...ONE RUNNING FROM SOUTH TO NORTH ACROSS THE CENTER OF
THE AREA AND ANOTHER AREA APPROACHING THE NORTHWEST CORNER. WEAK
SHORTWAVE TROUGH SHOULD TRANSITIONING ACROSS THE AREA THROUGH THE
EVENING. SO STORMS LOOK TO GRADUALLY END FROM WEST TO EAST DURING
THE NIGHT.
INDICATIONS ARE THAT WILL DEFINITELY HAVE STRATUS MOVE ACROSS THE
AREA BEHIND THE RAIN WITH SOME PATCHY FOG POSSIBLE. HAVE THIS LAST
THROUGH MID MORNING. BY THE MIDDLE OF THE DAY...SURFACE BOUNDARY
SETS UP JUST EAST OF THE KANSAS AND COLORADO BORDER. MID AND UPPER
LEVEL LIFT LOOKS TO BE STRONGER THAN TODAY SO AGAIN LOOK TO HAVE
ANOTHER GOOD CHANCE OF STORMS...SOME SEVERE...IN THE AFTERNOON.
DUE TO LACK OF TIME DID NOT CHANGE THE TEMPERATURES THROUGH
TOMORROW TOO MUCH. IT DOES LOOK WARMER TOMORROW.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 301 PM MDT WED MAY 27 2015
AGAIN NOT A LOT OF TIME DUE TO ONGOING SEVERE WEATHER. HIGH CHANCE
OF THUNDERSTORMS TO OCCUR THURSDAY NIGHT DUE TO RATHER STRONG
UPPER TROUGH MOVING THROUGH. SAME TROUGH WILL CONTINUE TO BRING
THUNDERSTORM CHANCES TO THE AREA THROUGH FRIDAY NIGHT. RIDGING AND
DRY CONDITIONS LOOK TO BE IN STORE FROM SATURDAY INTO SUNDAY.
ISOLATED THUNDERSTORMS LOOK TO BE POSSIBLE SUNDAY NIGHT INTO
MONDAY NIGHT.
FROM TUESDAY THROUGH WEDNESDAY...FLOW BECOME MORE SOUTHWEST WITH A
BETTER CHANCE OF STRONGER SHORTWAVE TROUGHS TO MOVE THROUGH. SO
THE CHANCE OF THUNDERSTORMS WILL BE A LITTLE BETTER DURING THIS
PERIOD. TEMPERATURES WERE NOT CHANGED FROM WHAT THE CRH_INIT
PRODUCED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM MDT WED MAY 27 2015
SEVERAL AVIATION CONCERNS ANTICIPATED THIS FORECAST. FIRST...LOW
LEVEL JET HAS STRENGTHENED OVER KGLD. HOWEVER...STRONGER WINDS AT
THE SURFACE THROUGHOUT THE NIGHT MAY PREVENT LLWS DEVELOPMENT.
SECOND...FOG/STRATUS IS LIKELY BY MORNING AT BOTH SITES. FEEL
CONDITIONS MAY BE WORSE AT KGLD WHERE THERE IS MORE OF AN
OPPORTUNITY FOR CLEARING OF THUNDERSTORM ANVIL MATTER. THIRD...A
STRONG DISTURBANCE MOVES THROUGH TOMORROW AFTERNOON WITH
WIDESPREAD THUNDERSTORM INITIATION ALONG THE DRYLINE. BOTH SITES
HAVE A HIGH CHANCE FOR STORMS SO WENT AHEAD WITH A TEMPO GROUP AS
TIMING REMAINS A LITTLE SUSPECT DUE TO POTENTIAL EARLIER
DEVELOPMENT AND ANEMIC STORM MOVEMENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR KSZ001-002-013>015-028-029-042.
CO...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR COZ090.
NE...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR NEZ079-080.
&&
$$
UPDATE...RRH
SHORT TERM...BULLER
LONG TERM...BULLER
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1022 PM MDT WED MAY 27 2015
.UPDATE...
ISSUED AT 1022 PM MDT WED MAY 27 2015
DECIDED TO ISSUE A FLASH FLOOD WATCH FOR PORTIONS OF THE REGION
THIS EVENING. BASICALLY CHOSE TO OUTLINE THE LOCATIONS MOST
SUSCEPTIBLE TO FLASH FLOODING TOMORROW WHICH IS BASICALLY THE SAME
LOCATIONS THAT RECEIVED HEAVY RAIN TODAY AND IN THE VICINITY OF
THE DRYLINE. REASONING IS MANY LOCATIONS RECEIVED HEAVY RAIN WITH
REPORTS OF FLASH FLOODING...PARTICULARLY IN SOUTHWEST NEBRASKA.
THUNDERSTORMS ARE ONCE AGAIN EXPECTED TO DEVELOP TOMORROW WITH
ANEMIC FORWARD SPEEDS AND PRECIPITABLE WATER READINGS WELL ABOVE
NORMAL.
AMENDED FORECAST FOR LATEST TRENDS IN POPS...FOG/STRATUS EXPECTED
TONIGHT AND STORM CHANCES TOMORROW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 301 PM MDT WED MAY 27 2015
NOT A LOT OF TIME TO WRITE DUE TO ONGOING SEVERE WEATHER. MODELS
HAVING A HARD TIME WITH THE CONVECTION. RUC WOULD LOOK TO HAVE THE
RIGHT IDEA WITH THE MAIN CLUSTER OF CONVECTION OVER THE SOUTHEAST
PORTION OF THE AREA. TWO DIFFERENT AREAS OF SURFACE
CONVERGENCE...ONE RUNNING FROM SOUTH TO NORTH ACROSS THE CENTER OF
THE AREA AND ANOTHER AREA APPROACHING THE NORTHWEST CORNER. WEAK
SHORTWAVE TROUGH SHOULD TRANSITIONING ACROSS THE AREA THROUGH THE
EVENING. SO STORMS LOOK TO GRADUALLY END FROM WEST TO EAST DURING
THE NIGHT.
INDICATIONS ARE THAT WILL DEFINITELY HAVE STRATUS MOVE ACROSS THE
AREA BEHIND THE RAIN WITH SOME PATCHY FOG POSSIBLE. HAVE THIS LAST
THROUGH MID MORNING. BY THE MIDDLE OF THE DAY...SURFACE BOUNDARY
SETS UP JUST EAST OF THE KANSAS AND COLORADO BORDER. MID AND UPPER
LEVEL LIFT LOOKS TO BE STRONGER THAN TODAY SO AGAIN LOOK TO HAVE
ANOTHER GOOD CHANCE OF STORMS...SOME SEVERE...IN THE AFTERNOON.
DUE TO LACK OF TIME DID NOT CHANGE THE TEMPERATURES THROUGH
TOMORROW TOO MUCH. IT DOES LOOK WARMER TOMORROW.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 301 PM MDT WED MAY 27 2015
AGAIN NOT A LOT OF TIME DUE TO ONGOING SEVERE WEATHER. HIGH CHANCE
OF THUNDERSTORMS TO OCCUR THURSDAY NIGHT DUE TO RATHER STRONG
UPPER TROUGH MOVING THROUGH. SAME TROUGH WILL CONTINUE TO BRING
THUNDERSTORM CHANCES TO THE AREA THROUGH FRIDAY NIGHT. RIDGING AND
DRY CONDITIONS LOOK TO BE IN STORE FROM SATURDAY INTO SUNDAY.
ISOLATED THUNDERSTORMS LOOK TO BE POSSIBLE SUNDAY NIGHT INTO
MONDAY NIGHT.
FROM TUESDAY THROUGH WEDNESDAY...FLOW BECOME MORE SOUTHWEST WITH A
BETTER CHANCE OF STRONGER SHORTWAVE TROUGHS TO MOVE THROUGH. SO
THE CHANCE OF THUNDERSTORMS WILL BE A LITTLE BETTER DURING THIS
PERIOD. TEMPERATURES WERE NOT CHANGED FROM WHAT THE CRH_INIT
PRODUCED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 552 PM MDT WED MAY 27 2015
MODELS HAVING TROUBLE RESOLVING DETAILS WITH ONGOING THUNDERSTORMS...MAINLY
DUE TO MESOSCALE PROCESSES GOVERNING THE EVOLUTION OF THE
PRECIPITATION. MOST MODEL OUTPUT WOULD SAY THAT KGLD SHOULD BE
GETTING WET RIGHT NOW. HOWEVER CURRENT RADAR AND OBSERVATION
TRENDS SUPPORT KGLD STAYING DRY WITH THUNDERSTORMS REMAINING JUST
TO THE NORTH. SO KEPT VICINITY THUNDERSTORMS AT KGLD THROUGH THE
EVENING. BEGINNING LATE IN THE EVENING INTO THE OVERNIGHT
HOURS...STRATUS AND SOME FOG CREATING MVFR CONDITIONS WILL OCCUR
INTO THE MID MORNING HOURS ON THURSDAY.
KMCK HAS THE BETTER CHANCE OF SEEING THUNDERSTORMS. LARGE CLUSTER
OF STORMS IS NOT TOO FAR AWAY. THESE STORMS HAVE A HISTORY OF
PRODUCING HEAVY RAINFALL. AT THIS TIME MVFR CONDITIONS WILL BE
POSSIBLE UNTIL NEAR 06Z. AFTER THE THUNDERSTORMS END...MVFR
CONDITIONS IN FOG AND STRATUS WILL OCCUR INTO TOMORROW AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR KSZ001-002-013>015-028-029-042.
CO...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR COZ090.
NE...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR NEZ079-080.
&&
$$
UPDATE...RRH
SHORT TERM...BULLER
LONG TERM...BULLER
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1019 PM CDT FRI MAY 29 2015
.MESOSCALE DISCUSSION...
ISSUED AT 1019 PM CDT FRI MAY 29 2015
UPDATE...THE COMBINATION OF LOW LEVEL CONVERGENCE AND WIND FIELDS IN
THE CONVECTION OVER NORTHERN PERRY COUNTY IL (NORTH OF
PINCKNEYVILLE) SUGGEST SOME INITIAL DEVELOPMENT OF A SMALL MESO-
VORTEX. THIS MAY HELP TO MAINTAIN ELEVATED CONVECTION ALONG THE
WESTERN EDGE OF THE COLD POOL WEST OF JEFFERSON COUNTY IL.
A RATHER BROAD MESO-HIGH CENTERED OVER SOUTHEAST ILLINOIS
NORTHWEST OF CISNE IN WAYNE COUNTY ILLINOIS. THIS HAS MODFIED THE
SURFACE FLOW AND SHUNTED THE EFFECTIVE SURFACE BASED CAPE TOWARD
THE SHAWNEE HILLS IN SOUTHERN ILLINOIS. BETWEEN THE PREVIOUS
CONVECTION OVER THE FOOTHILLS OF SOUTHEAST MISSOURI AND PERSISTENT
SHOWERS AND THUNDERSTORMS OVER SOUTHWEST ILLINOIS THIS AFTERNOON
AND THIS EVENING...A SHARP CAPE GRADIENT HAS DEVELOPED SOUTH OF
THE BROAD COLD POOL AROUND THE MESO-HIGH. CAPES GREATER THAN 200
J/KG2 STRETCH FROM PERRYVILLE MO TO PRINCETON IN AS OF 9 PM CDT.
THE EAST-NORTHEASTERLY BOUNDARY LAYER FLOW AROUND THE MESO HIGH IS
HELING TO GENERATE SOME UPSHEAR COLD POOL CONVECTION FROM GALATIA
TO MURHPYSBORO IL...WHERE CONVERGENT FLOW IS SUPPORTING ENOUGH
VORTICITY FOR UPDRAFTS. FURTHER TO THE NORTH...CONVECTION HAS DIED
OFF GIVEN THE LACK OF DECENT MOIST INFLOW NEAR THE UPPER LEVEL OF
THE PLANETARY BOUNDARY LAYER. THIS SHOULD CONTINUE TO WEAKEN THE
COVERAGE AND INTENSITY OF SHOWERS AND THUNDERSTORMS FURTHER NORTH.
THIS IS ALSO SUGGESTED BY THE HRRR GUIDANCE THROUGH MIDNIGHT.
ANTICIPATE SOME MAINTENANCE OF CONVECTION OVER PERRY...WILLIAMSON
AND JEFFERSON COUNTIES FOR ANOTHER HOUR OR SO.
THE CAPE GRADIENT FURTHER SOUTH OVER THE REST OF THE WFO PAH
FORECAST AREA WILL SERVE AS A GOOD DIFFERENTIAL THETA-E BOUNDARY
AND HEATING BOUNDARY FOR SATURDAY AND MAY SERVE AS A FOCAL POINT
FOR SUSTAINED CONVECTION ON SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 132 PM CDT FRI MAY 29 2015
THE HRRR PICKS UP ON CONVECTION TO OUR WEST IF OVERDONE A TAD. IT
BASICALLY MIGRATES SCATTERED CONVECTIVE ELEMENTS INTO OUR SEMO
OZARK COUNTIES TONIGHT. IT DOS NOT MODEL ACCURATELY THE WIDELY
SCATTERED ACTIVITY IN OUR EAST...BUT DOES SUGGEST SIMILAR TREND
THERE INTO THE EARLY EVENING HOURS.
OVER TIME...SYNOPTIC MODELING IS THE SAME...DRAWING FRONT IN AND
THIS WEEKEND WITH PASSAGE AND HIGH POP EVENT. LACKING STRONG
FORCING...IT APPEARS TO BE MAINLY A HEAVY RAIN THREAT...WITH
PERHAPS PULSE MAINLY HEAT OF DAY STORMS BEARING WATCH ON THEIR
INTENSITY. POPS PEAK ALONG/AHEAD OF PASSING BOUNDARY SATURDAY INTO
SATURDAY NIGHT.
ON THE BACK SIDE OF THE FRONT BEGINNING SUNDAY INTO SUNDAY
NIGHT...POPS MAY LINGER BUT DRIER AIR STARTS TO WORK DOWN THE
COLUMN. WE`LL SEE SOME DEW POINTS DROPPING BACK INTO THE 50S THEN
AND EFFECTIVELY THIS WILL WORK TOWARD ENDING POPS FROM NORTHWEST
TO SOUTHEAST WITH TIME.
SUMMER LIKE WARMTH/HUMIDITY 80S/60S CONTINUES UNTIL FROPA...AFTER
WHICH THE MOVE BACK INTO THE 70S/50S COMMENCES SUNDAY-SUNDAY
NIGHT.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 153 PM CDT FRI MAY 29 2015
A WEAK UPPER-LEVEL FLOW PATTERN WILL CONTINUE THROUGH THE LONG
TERM...WHICH SHOULD BECOME MORE FREQUENT AS WE HEAD INTO THE SUMMER
MONTHS. EARLY IN THE WEEK...WEAK TROUGHING OVER THE LOWER OHIO
VALLEY WILL BRING SOMEWHAT COOLER AND DRIER CONDITIONS. BROAD
RIDGING WILL FOLLOW IN THE WAKE OF THE TROUGH FOR MID TO LATE WEEK.
THIS WILL RESULT IN A GRADUAL INCREASE IN WARMTH AND HUMIDITY.
AS FAR AS THE SPECIFICS...MONDAY THROUGH TUESDAY NOW LOOK MAINLY DRY
AND A LITTLE COOLER. THE MODELS HAVE TRENDED DRIER AND A BIT COOLER.
POPS WILL BE REMOVED FOR MUCH OF THE AREA...BUT A SLIGHT CHANCE OF
SHOWERS WILL BE KEPT FOR PARTS OF WESTERN KENTUCKY. WITH THE COOLER
AND DRIER AIR...INSTABILITY LOOKS TOO LIMITED FOR THUNDER. LINGERING
CLOUDS SHOULD KEEP HIGHS IN THE 70S ON MONDAY. EVEN WITH LOTS OF SUN
ON TUESDAY...HIGHS SHOULD GENERALLY BE AROUND 80 DEGREES. AS FOR
OVERNIGHT LOWS...HIGH PRESSURE OVER THE GREAT LAKES WILL BRING DRIER
AIR AND LIGHT WINDS...WHICH SHOULD ALLOW MOST PLACES TO FALL INTO
THE 50S.
WEDNESDAY THROUGH FRIDAY...LOW LEVEL WINDS WILL VEER FROM THE EAST
INTO THE SOUTH AS THE HIGHS RETREATS TO THE EAST COAST. LOW LEVEL
MOISTURE WILL SLOWLY CREEP UP. WITH THE INCREASING MOISTURE WILL
COME A SMALL CHANCE OF DIURNALLY INDUCED SHOWERS AND
STORMS...ESPECIALLY THURSDAY AND FRIDAY. HIGHS WILL INCH BACK INTO
THE LOWER AND MID 80S...AND OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.AVIATION...
ISSUED AT 607 PM CDT FRI MAY 29 2015
PRIOR TO THE EFFECTIVE ISSUANCE OF THE 00Z SATURDAY WFO PAH TAF
FORECAST PACKAGE...A SMALL CLUSTER OF SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO MOVE NORTHWEST OF THE KCGI TAF SITE...SO DID NOT
INCLUDE PRECIPITATION AT THE BEGINNING OF THE FORECAST. THE
OVERALL CLUSTER OF SHOWERS AND THUNDERSTORMS MAY PERSIST BRIEFLY
WITH THE DEVELOPMENT OF A WEAK LOW LEVEL JET...SO ADDED A MENTION
OF RAIN IN THE 03Z-07Z TIME FRAME AT KCGI.
THE BULK OF CONVECTION SHOUSL HOLD OFF UNTIL TOMORROW AFTERNOON.
ATTEMPTED TO KEEP VFR CEILINGS AND VISIBILITIES FOR MOST OF THE
TAF SITES IN PLACE PRIOR TO THE ONSET OF CONVECTION ON SATURDAY.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
MESOSCALE...SMITH
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1007 PM CDT FRI MAY 29 2015
.MESOSCALE DISCUSSION...
ISSUED AT 1007 PM CDT FRI MAY 29 2015
A RATHER BROAD MESO-HIGH CENTERED OVER SOUTHEAST ILLINOIS
NORTHWEST OF CISNE IN WAYNE COUNTY ILLINOIS. THIS HAS MODFIED THE
SURFACE FLOW AND SHUNTED THE EFFECTIVE SURFACE BASED CAPE TOWARD
THE SHAWNEE HILLS IN SOUTHERN ILLINOIS. BETWEEN THE PREVIOUS
CONVECTION OVER THE FOOTHILLS OF SOUTHEAST MISSOURI AND PERSISTENT
SHOWERS AND THUNDERSTORMS OVER SOUTHWEST ILLINOIS THIS AFTERNOON
AND THIS EVENING...A SHARP CAPE GRADIENT HAS DEVELOPED SOUTH OF
THE BROAD COLD POOL AROUND THE MESO-HIGH. CAPES GREATER THAN 200
J/KG2 STRETCH FROM PERRYVILLE MO TO PRINCETON IN AS OF 9 PM CDT.
THE EAST-NORTHEASTERLY BOUNDARY LAYER FLOW AROUND THE MESO HIGH IS
HELING TO GENERATE SOME UPSHEAR COLD POOL CONVECTION FROM GALATIA
TO MURHPYSBORO IL...WHERE CONVERGENT FLOW IS SUPPORTING ENOUGH
VORTICITY FOR UPDRAFTS. FURTHER TO THE NORTH...CONVECTION HAS DIED
OFF GIVEN THE LACK OF DECENT MOIST INFLOW NEAR THE UPPER LEVEL OF
THE PLANETARY BOUNDARY LAYER. THIS SHOULD CONTINUE TO WEAKEN THE
COVERAGE AND INTENSITY OF SHOWERS AND THUNDERSTORMS FURTHER NORTH.
THIS IS ALSO SUGGESTED BY THE HRRR GUIDANCE THROUGH MIDNIGHT.
ANTICIPATE SOME MAINTENANCE OF CONVECTION OVER PERRY...WILLIAMSON
AND JEFFERSON COUNTIES FOR ANOTHER HOUR OR SO.
THE CAPE GRADIENT FURTHER SOUTH OVER THE REST OF THE WFO PAH
FORECAST AREA WILL SERVE AS A GOOD DIFFERENTIAL THETA-E BOUNDARY
AND HEATING BOUNDARY FOR SATURDAY AND MAY SERVE AS A FOCAL POINT
FOR SUSTAINED CONVECTION ON SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 132 PM CDT FRI MAY 29 2015
THE HRRR PICKS UP ON CONVECTION TO OUR WEST IF OVERDONE A TAD. IT
BASICALLY MIGRATES SCATTERED CONVECTIVE ELEMENTS INTO OUR SEMO
OZARK COUNTIES TONIGHT. IT DOS NOT MODEL ACCURATELY THE WIDELY
SCATTERED ACTIVITY IN OUR EAST...BUT DOES SUGGEST SIMILAR TREND
THERE INTO THE EARLY EVENING HOURS.
OVER TIME...SYNOPTIC MODELING IS THE SAME...DRAWING FRONT IN AND
THIS WEEKEND WITH PASSAGE AND HIGH POP EVENT. LACKING STRONG
FORCING...IT APPEARS TO BE MAINLY A HEAVY RAIN THREAT...WITH
PERHAPS PULSE MAINLY HEAT OF DAY STORMS BEARING WATCH ON THEIR
INTENSITY. POPS PEAK ALONG/AHEAD OF PASSING BOUNDARY SATURDAY INTO
SATURDAY NIGHT.
ON THE BACK SIDE OF THE FRONT BEGINNING SUNDAY INTO SUNDAY
NIGHT...POPS MAY LINGER BUT DRIER AIR STARTS TO WORK DOWN THE
COLUMN. WE`LL SEE SOME DEW POINTS DROPPING BACK INTO THE 50S THEN
AND EFFECTIVELY THIS WILL WORK TOWARD ENDING POPS FROM NORTHWEST
TO SOUTHEAST WITH TIME.
SUMMER LIKE WARMTH/HUMIDITY 80S/60S CONTINUES UNTIL FROPA...AFTER
WHICH THE MOVE BACK INTO THE 70S/50S COMMENCES SUNDAY-SUNDAY
NIGHT.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 153 PM CDT FRI MAY 29 2015
A WEAK UPPER-LEVEL FLOW PATTERN WILL CONTINUE THROUGH THE LONG
TERM...WHICH SHOULD BECOME MORE FREQUENT AS WE HEAD INTO THE SUMMER
MONTHS. EARLY IN THE WEEK...WEAK TROUGHING OVER THE LOWER OHIO
VALLEY WILL BRING SOMEWHAT COOLER AND DRIER CONDITIONS. BROAD
RIDGING WILL FOLLOW IN THE WAKE OF THE TROUGH FOR MID TO LATE WEEK.
THIS WILL RESULT IN A GRADUAL INCREASE IN WARMTH AND HUMIDITY.
AS FAR AS THE SPECIFICS...MONDAY THROUGH TUESDAY NOW LOOK MAINLY DRY
AND A LITTLE COOLER. THE MODELS HAVE TRENDED DRIER AND A BIT COOLER.
POPS WILL BE REMOVED FOR MUCH OF THE AREA...BUT A SLIGHT CHANCE OF
SHOWERS WILL BE KEPT FOR PARTS OF WESTERN KENTUCKY. WITH THE COOLER
AND DRIER AIR...INSTABILITY LOOKS TOO LIMITED FOR THUNDER. LINGERING
CLOUDS SHOULD KEEP HIGHS IN THE 70S ON MONDAY. EVEN WITH LOTS OF SUN
ON TUESDAY...HIGHS SHOULD GENERALLY BE AROUND 80 DEGREES. AS FOR
OVERNIGHT LOWS...HIGH PRESSURE OVER THE GREAT LAKES WILL BRING DRIER
AIR AND LIGHT WINDS...WHICH SHOULD ALLOW MOST PLACES TO FALL INTO
THE 50S.
WEDNESDAY THROUGH FRIDAY...LOW LEVEL WINDS WILL VEER FROM THE EAST
INTO THE SOUTH AS THE HIGHS RETREATS TO THE EAST COAST. LOW LEVEL
MOISTURE WILL SLOWLY CREEP UP. WITH THE INCREASING MOISTURE WILL
COME A SMALL CHANCE OF DIURNALLY INDUCED SHOWERS AND
STORMS...ESPECIALLY THURSDAY AND FRIDAY. HIGHS WILL INCH BACK INTO
THE LOWER AND MID 80S...AND OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.AVIATION...
ISSUED AT 607 PM CDT FRI MAY 29 2015
PRIOR TO THE EFFECTIVE ISSUANCE OF THE 00Z SATURDAY WFO PAH TAF
FORECAST PACKAGE...A SMALL CLUSTER OF SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO MOVE NORTHWEST OF THE KCGI TAF SITE...SO DID NOT
INCLUDE PRECIPITATION AT THE BEGINNING OF THE FORECAST. THE
OVERALL CLUSTER OF SHOWERS AND THUNDERSTORMS MAY PERSIST BRIEFLY
WITH THE DEVELOPMENT OF A WEAK LOW LEVEL JET...SO ADDED A MENTION
OF RAIN IN THE 03Z-07Z TIME FRAME AT KCGI.
THE BULK OF CONVECTION SHOUSL HOLD OFF UNTIL TOMORROW AFTERNOON.
ATTEMPTED TO KEEP VFR CEILINGS AND VISIBILITIES FOR MOST OF THE
TAF SITES IN PLACE PRIOR TO THE ONSET OF CONVECTION ON SATURDAY.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
MESOSCALE...SMITH
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS JACKSON KY
942 PM EDT FRI MAY 29 2015
.UPDATE...
ISSUED AT 942 PM EDT FRI MAY 29 2015
MOST OF THE AFTERNOON CONVECTION HAS WANED WITH LOSS OF DAYTIME
HEATING SO HAVE REDUCED POPS AND REMOVED THUNDER FROM THE GRIDS
FOR THE OVERNIGHT PERIOD. THERE IS ONE LONELY STORM IN THE CWA BUT
EXPECT THAT TO WEAKEN OVER THE NEXT HOUR. TEMPS ARE A BIT COOLER
THAN PREVIOUSLY FORECAST DUE TO THE EVENING SHOWER ACTIVITY SO
ADJUSTED THOSE TO BETTER REFLECT THE OBS. OTHERWISE...FORECAST
REMAINS ON TRACK. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS.
UPDATE ISSUED AT 635 PM EDT FRI MAY 29 2015
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE THROUGH
EASTERN KENTUCKY THIS EVENING. THE MOST PROMINENT SHOWERS AND
STORMS ARE CURRENTLY IMPACTING KNOTT/FLOYD/JOHNSON COUNTIES AND
POINTS EAST...WHERE SEVERAL OUTFLOW BOUNDARIES HAVE COLLIDED
TOGETHER. OTHERWISE...ISOLATED SHOWERS ARE EXPECTED TO CONTINUE
ACROSS THE AREA FOR AT LEAST THE NEXT COUPLE OF HOURS. IN TERMS
OF THE FORECAST...GRIDS APPEAR ON TRACK SO ONLY MADE MINOR
ADJUSTMENTS TO THE TEMP GRIDS TO REFLECT MOST RECENT OBS. SENT
UPDATED GRIDS TO NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM EDT FRI MAY 29 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL OVER FAR EASTERN
KENTUCKY WHILE LOW PRESSURE IS FOUND TO THE WEST OF THE AREA.
BETWEEN THESE...A SOUTHERLY FLOW OF AIR IS SUPPORTING WARM
TEMPERATURES AND HUMID CONDITIONS. WITH PARTLY SUNNY SKIES THE
INSTABILITY WAS SUFFICIENT TO KICK OFF SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS ACROSS THE AREA BY EARLY AFTERNOON.
THIS CONVECTION IS FAVORING THE WESTERN PORTION OF THE CWA WHERE A
BIT MORE SUNSHINE WAS SEEN EARLIER IN THE DAY AND DEWPOINTS WERE
HIGHER. OTHERWISE...TEMPERATURES MADE IT INTO THE LOW TO MID 80S
BEFORE THE PRECIPITATION KNOCKED THEM BACK INTO THE 70S...FOR A
TIME...IN MANY LOCATIONS. WINDS HAVE BEEN GENERALLY FROM THE
SOUTH AT 5 TO 10 KTS ACROSS THE AREA WHILE DEWPOINTS MADE IT INTO
THE MID AND UPPER 60S IN THE WEST...BUT FELL INTO THE UPPER 50S
IN THE FAR EAST...CLOSER TO THE HEART OF THE HIGH PRESSURE.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL SHOW THE WEAK SOUTHEAST RIDGE
SHIFTING OFF TO THE EAST IN THE FACE OF AN APPROACHING TROUGH FROM
THE SOUTHERN PLAINS. THE ENERGY FROM THIS WILL MOVE INTO KENTUCKY
ON SATURDAY AND PASS THROUGH THE STATE BY SUNDAY MORNING...WITH
ITS CORE PASSING BY TO THE NORTHWEST. IMPROVING UPPER LEVEL
CONDITIONS SHOULD FAVOR CONVECTION ACROSS THE AREA DURING THE
AFTERNOON AND EARLY EVENING HOURS WITH THE HIGHER RESOLUTION
NAM12 AND HRRR MODELS FAVORED FOR SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE SCATTERED CONVECTION SETTLING
DOWN AFTER SUNSET ACROSS THE AREA...THOUGH ISOLATED SHOWERS WILL
BE POSSIBLE THROUGH THE NIGHT. THIS WILL SET THE STAGE FOR PATCHY
FOG DEVELOPING LATER IN THE NIGHT...BECOMING LOCALLY DENSE IN THE
VALLEYS TOWARD DAWN WITH MILD AND MUGGY CONDITIONS IN PLACE. THE
APPROACH OF A COLD FRONT...ASSOCIATED WITH THE SFC LOW PASSING
THROUGH SOUTHERN INDIANA SATURDAY WILL BRING A THREAT OF STORMS
AGAIN FOR THE AREA...MAINLY IN THE MID AND LATE AFTERNOON HOURS
AND OVER THE WESTERN PARTS OF THE CWA. THE GFS HAS THE BEST TIMING
AND PROGRESSION OF THE FRONT AS IT PASSES THROUGH EAST KENTUCKY.
AND WAS USED AS A TEMPLATE THROUGH 12Z SUNDAY. MEANWHILE...THE
NAM12 AND ECMWF SPLIT THE FRONT MOVING IT THROUGH EAST KENTUCKY
LATER SATURDAY NIGHT AND INTO SUNDAY MORNING...TAKING THE MAIN LOW
INTO OHIO AND BYPASSING THIS PART OF THE STATE TO THE NORTH. THIS
TRANSITION MAY LIMIT THE QPF OVER THE CWA COMPARED TO THE WEST AND
NORTH...ALSO SEEN IN THE GFS...LOWERING CONFIDENCE IN A NEEDED
SOAKING RAIN FOR MUCH OF THE AREA. ACCORDINGLY...HAVE KEPT POPS IN
THE MID TO HIGH CHANCE RANGE THROUGH 12Z SUNDAY.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND
GRIDS INTO SATURDAY BEFORE SWITCHING TO THE SUPERBLEND THROUGH
12Z SUNDAY. MADE SOME MINOR RIDGE TO VALLEY TEMPERATURE
ADJUSTMENTS FOR LOWS AND HOURLY TEMPS EACH NIGHT. AS FOR POPS...
ENDED UP A BIT HIGHER THAN A BLEND OF THE DRIER MET AND WETTER MAV
GUIDANCE THROUGH THE SHORT TERM WITH AN EXAGGERATED DIURNAL CYCLE
FOR THE HOURLY POPS/WX GRIDS THROUGH SATURDAY EVENING AND MORE OF
A SYNOPTIC DRIVEN POP GRID FOR SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 235 PM EDT FRI MAY 29 2015
BASED ON MODEL TRENDS OVER THE PAST 24 HOURS...WENT AHEAD AND MADE
SOME FAIRLY SUBSTANTIAL CHANGES TO THE FORECAST FOR NEXT WEEK WHICH
WILL INVOLVE MUCH LESS RAIN CHANCES.
AT THE START OF THE PERIOD...ON SUNDAY...A VORT MAX WILL BE LIFTING
NORTHWARD ACROSS WESTERN KENTUCKY INTO INDIANA AND OHIO. THIS SYSTEM
WILL HAVE SOME GOOD DYNAMICS ASSOCIATED WITH IT TO PRODUCE GOOD
COVERAGE OF SHOWERS AND PERHAPS SOME STORMS OVER THESE AREAS.
HOWEVER...THIS FORCING JUST GRAZES THE BLUEGRASS REGION OF EASTERN
KENTUCKY...WITH MOST OF THE FORCING STAYING TO OUR NORTH.
HOWEVER...THIS WAVE WILL SEND A FRONTAL BOUNDARY SOUTH ACROSS THE
AREA AND WITH THE POSSIBILITY OF SOME INSTABILITY DEVELOPING ON
SUNDAY...WE COULD SEE SHOWERS AND STORMS INCREASE IN COVERAGE AS THE
BOUNDARY PUSHES EAST THROUGH THE DAY. STILL PLENTY OF OPPORTUNITY
FOR THE INSTABILITY TO NOT MATERIALIZE AND WE END UP DRIER THAN
EXPECTED. SAFE TO SAY...CONFIDENCE IS NOT HIGH ON RAIN CHANCES ON
SUNDAY. IN FACT...THE GFS GUIDANCE HAS BECOME MUCH MORE PESSIMISTIC
ON RAIN CHANCES ON SUNDAY. ECMWF REMAIN A BIT SLOWER WITH THIS WAVE
AND FRONT...WHICH WOULD PROVIDE BETTER SUPPORT FOR RAIN ON SUNDAY IF
THE FRONT CAN STALL OVER OUR REGION.
BY SUNDAY NIGHT INTO MONDAY...IT LOOKS LIKE BOUNDARY WILL SHIFT
SOUTH AND EAST...WITH PERHAPS SOME SLIGHT CHANCES FOR SHOWERS
LINGERING INTO MONDAY ACROSS SOUTHEAST KENTUCKY. HOWEVER...MODELS
ARE COMING INTO BETTER AGREEMENT ON DRY WEATHER FROM LATE MONDAY
THROUGH WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS EAST ACROSS THE OHIO
RIVER VALLEY. THIS WARRANTS REMOVING RAIN CHANCES FROM MONDAY NIGHT
ONWARD. AS THE HIGH SETTLES EAST BY THURSDAY...SOME RETURN FLOW MAY
DEVELOP WITH SOME MOISTURE RETURNING...WHICH COULD BRING BACK THE
POSSIBILITY OF AN AFTERNOON SHOWER OR THUNDERSTORM.
REGARDLESS...RAIN CHANCES WILL REMAIN LOW THROUGH THE END OF NEXT
WEEK. A BRIEF COOL DOWN...WITH LOWER HUMIDITIES WILL BE SEEN EARLY
IN THE COMING WEEK BEHIND THE FRONTAL BOUNDARY...BUT TEMPERATURES
WILL RETURN TO ABOVE NORMAL BY MIDDLE TO END OF NEXT WEEK ALONG WITH
HIGHER HUMIDITY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 745 PM EDT FRI MAY 29 2015
SCATTERED CONVECTION IS EXPECTED TO CONTINUE FOR THE HOUR OR SO
THEN WANE AFTER SUNSET. THIS WARRANTS KEEPING VCTS AT MOST OF THE
TAF SITES THROUGH ABOUT 02Z. ONCE THE CONVECTION DISSIPATES SOME
PATCHY FOG WILL LIKELY DEVELOP AGAIN IN THE VALLEYS AFTER 06Z
AFFECTING MOST OF THE TAF SITES WITH SOME MVFR VIS. IFR VIS MAY
ALSO BE POSSIBLE TONIGHT IN LOCATIONS WHERE IT
RAINED...PARTICULARLY THE SJS...SME AND LOZ TAF SITES.
ISOLATED TO SCATTERED CONVECTION WILL BE POSSIBLE BY EARLY
AFTERNOON ON SATURDAY WITH VCTS AGAIN INCLUDED. WINDS WILL
GENERALLY BE LIGHT AND VARIABLE FROM THE SOUTH THROUGH SATURDAY
MORNING...PICKING UP AGAIN LATER IN THE DAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JVM/GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
746 PM EDT FRI MAY 29 2015
.UPDATE...
ISSUED AT 635 PM EDT FRI MAY 29 2015
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE THROUGH
EASTERN KENTUCKY THIS EVENING. THE MOST PROMINENT SHOWERS AND
STORMS ARE CURRENTLY IMPACTING KNOTT/FLOYD/JOHNSON COUNTIES AND
POINTS EAST...WHERE SEVERAL OUTFLOW BOUNDARIES HAVE COLLIDED
TOGETHER. OTHERWISE...ISOLATED SHOWERS ARE EXPECTED TO CONTINUE
ACROSS THE AREA FOR AT LEAST THE NEXT COUPLE OF HOURS. IN TERMS
OF THE FORECAST...GRIDS APPEAR ON TRACK SO ONLY MADE MINOR
ADJUSTMENTS TO THE TEMP GRIDS TO REFLECT MOST RECENT OBS. SENT
UPDATED GRIDS TO NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM EDT FRI MAY 29 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL OVER FAR EASTERN
KENTUCKY WHILE LOW PRESSURE IS FOUND TO THE WEST OF THE AREA.
BETWEEN THESE...A SOUTHERLY FLOW OF AIR IS SUPPORTING WARM
TEMPERATURES AND HUMID CONDITIONS. WITH PARTLY SUNNY SKIES THE
INSTABILITY WAS SUFFICIENT TO KICK OFF SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS ACROSS THE AREA BY EARLY AFTERNOON.
THIS CONVECTION IS FAVORING THE WESTERN PORTION OF THE CWA WHERE A
BIT MORE SUNSHINE WAS SEEN EARLIER IN THE DAY AND DEWPOINTS WERE
HIGHER. OTHERWISE...TEMPERATURES MADE IT INTO THE LOW TO MID 80S
BEFORE THE PRECIPITATION KNOCKED THEM BACK INTO THE 70S...FOR A
TIME...IN MANY LOCATIONS. WINDS HAVE BEEN GENERALLY FROM THE
SOUTH AT 5 TO 10 KTS ACROSS THE AREA WHILE DEWPOINTS MADE IT INTO
THE MID AND UPPER 60S IN THE WEST...BUT FELL INTO THE UPPER 50S
IN THE FAR EAST...CLOSER TO THE HEART OF THE HIGH PRESSURE.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL SHOW THE WEAK SOUTHEAST RIDGE
SHIFTING OFF TO THE EAST IN THE FACE OF AN APPROACHING TROUGH FROM
THE SOUTHERN PLAINS. THE ENERGY FROM THIS WILL MOVE INTO KENTUCKY
ON SATURDAY AND PASS THROUGH THE STATE BY SUNDAY MORNING...WITH
ITS CORE PASSING BY TO THE NORTHWEST. IMPROVING UPPER LEVEL
CONDITIONS SHOULD FAVOR CONVECTION ACROSS THE AREA DURING THE
AFTERNOON AND EARLY EVENING HOURS WITH THE HIGHER RESOLUTION
NAM12 AND HRRR MODELS FAVORED FOR SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE SCATTERED CONVECTION SETTLING
DOWN AFTER SUNSET ACROSS THE AREA...THOUGH ISOLATED SHOWERS WILL
BE POSSIBLE THROUGH THE NIGHT. THIS WILL SET THE STAGE FOR PATCHY
FOG DEVELOPING LATER IN THE NIGHT...BECOMING LOCALLY DENSE IN THE
VALLEYS TOWARD DAWN WITH MILD AND MUGGY CONDITIONS IN PLACE. THE
APPROACH OF A COLD FRONT...ASSOCIATED WITH THE SFC LOW PASSING
THROUGH SOUTHERN INDIANA SATURDAY WILL BRING A THREAT OF STORMS
AGAIN FOR THE AREA...MAINLY IN THE MID AND LATE AFTERNOON HOURS
AND OVER THE WESTERN PARTS OF THE CWA. THE GFS HAS THE BEST TIMING
AND PROGRESSION OF THE FRONT AS IT PASSES THROUGH EAST KENTUCKY.
AND WAS USED AS A TEMPLATE THROUGH 12Z SUNDAY. MEANWHILE...THE
NAM12 AND ECMWF SPLIT THE FRONT MOVING IT THROUGH EAST KENTUCKY
LATER SATURDAY NIGHT AND INTO SUNDAY MORNING...TAKING THE MAIN LOW
INTO OHIO AND BYPASSING THIS PART OF THE STATE TO THE NORTH. THIS
TRANSITION MAY LIMIT THE QPF OVER THE CWA COMPARED TO THE WEST AND
NORTH...ALSO SEEN IN THE GFS...LOWERING CONFIDENCE IN A NEEDED
SOAKING RAIN FOR MUCH OF THE AREA. ACCORDINGLY...HAVE KEPT POPS IN
THE MID TO HIGH CHANCE RANGE THROUGH 12Z SUNDAY.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND
GRIDS INTO SATURDAY BEFORE SWITCHING TO THE SUPERBLEND THROUGH
12Z SUNDAY. MADE SOME MINOR RIDGE TO VALLEY TEMPERATURE
ADJUSTMENTS FOR LOWS AND HOURLY TEMPS EACH NIGHT. AS FOR POPS...
ENDED UP A BIT HIGHER THAN A BLEND OF THE DRIER MET AND WETTER MAV
GUIDANCE THROUGH THE SHORT TERM WITH AN EXAGGERATED DIURNAL CYCLE
FOR THE HOURLY POPS/WX GRIDS THROUGH SATURDAY EVENING AND MORE OF
A SYNOPTIC DRIVEN POP GRID FOR SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 235 PM EDT FRI MAY 29 2015
BASED ON MODEL TRENDS OVER THE PAST 24 HOURS...WENT AHEAD AND MADE
SOME FAIRLY SUBSTANTIAL CHANGES TO THE FORECAST FOR NEXT WEEK WHICH
WILL INVOLVE MUCH LESS RAIN CHANCES.
AT THE START OF THE PERIOD...ON SUNDAY...A VORT MAX WILL BE LIFTING
NORTHWARD ACROSS WESTERN KENTUCKY INTO INDIANA AND OHIO. THIS SYSTEM
WILL HAVE SOME GOOD DYNAMICS ASSOCIATED WITH IT TO PRODUCE GOOD
COVERAGE OF SHOWERS AND PERHAPS SOME STORMS OVER THESE AREAS.
HOWEVER...THIS FORCING JUST GRAZES THE BLUEGRASS REGION OF EASTERN
KENTUCKY...WITH MOST OF THE FORCING STAYING TO OUR NORTH.
HOWEVER...THIS WAVE WILL SEND A FRONTAL BOUNDARY SOUTH ACROSS THE
AREA AND WITH THE POSSIBILITY OF SOME INSTABILITY DEVELOPING ON
SUNDAY...WE COULD SEE SHOWERS AND STORMS INCREASE IN COVERAGE AS THE
BOUNDARY PUSHES EAST THROUGH THE DAY. STILL PLENTY OF OPPORTUNITY
FOR THE INSTABILITY TO NOT MATERIALIZE AND WE END UP DRIER THAN
EXPECTED. SAFE TO SAY...CONFIDENCE IS NOT HIGH ON RAIN CHANCES ON
SUNDAY. IN FACT...THE GFS GUIDANCE HAS BECOME MUCH MORE PESSIMISTIC
ON RAIN CHANCES ON SUNDAY. ECMWF REMAIN A BIT SLOWER WITH THIS WAVE
AND FRONT...WHICH WOULD PROVIDE BETTER SUPPORT FOR RAIN ON SUNDAY IF
THE FRONT CAN STALL OVER OUR REGION.
BY SUNDAY NIGHT INTO MONDAY...IT LOOKS LIKE BOUNDARY WILL SHIFT
SOUTH AND EAST...WITH PERHAPS SOME SLIGHT CHANCES FOR SHOWERS
LINGERING INTO MONDAY ACROSS SOUTHEAST KENTUCKY. HOWEVER...MODELS
ARE COMING INTO BETTER AGREEMENT ON DRY WEATHER FROM LATE MONDAY
THROUGH WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS EAST ACROSS THE OHIO
RIVER VALLEY. THIS WARRANTS REMOVING RAIN CHANCES FROM MONDAY NIGHT
ONWARD. AS THE HIGH SETTLES EAST BY THURSDAY...SOME RETURN FLOW MAY
DEVELOP WITH SOME MOISTURE RETURNING...WHICH COULD BRING BACK THE
POSSIBILITY OF AN AFTERNOON SHOWER OR THUNDERSTORM.
REGARDLESS...RAIN CHANCES WILL REMAIN LOW THROUGH THE END OF NEXT
WEEK. A BRIEF COOL DOWN...WITH LOWER HUMIDITIES WILL BE SEEN EARLY
IN THE COMING WEEK BEHIND THE FRONTAL BOUNDARY...BUT TEMPERATURES
WILL RETURN TO ABOVE NORMAL BY MIDDLE TO END OF NEXT WEEK ALONG WITH
HIGHER HUMIDITY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 745 PM EDT FRI MAY 29 2015
SCATTERED CONVECTION IS EXPECTED TO CONTINUE FOR THE HOUR OR SO
THEN WANE AFTER SUNSET. THIS WARRANTS KEEPING VCTS AT MOST OF THE
TAF SITES THROUGH ABOUT 02Z. ONCE THE CONVECTION DISSIPATES SOME
PATCHY FOG WILL LIKELY DEVELOP AGAIN IN THE VALLEYS AFTER 06Z
AFFECTING MOST OF THE TAF SITES WITH SOME MVFR VIS. IFR VIS MAY
ALSO BE POSSIBLE TONIGHT IN LOCATIONS WHERE IT
RAINED...PARTICULARLY THE SJS...SME AND LOZ TAF SITES.
ISOLATED TO SCATTERED CONVECTION WILL BE POSSIBLE BY EARLY
AFTERNOON ON SATURDAY WITH VCTS AGAIN INCLUDED. WINDS WILL
GENERALLY BE LIGHT AND VARIABLE FROM THE SOUTH THROUGH SATURDAY
MORNING...PICKING UP AGAIN LATER IN THE DAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JVM/GREIF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
607 PM CDT FRI MAY 29 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 132 PM CDT FRI MAY 29 2015
THE HRRR PICKS UP ON CONVECTION TO OUR WEST IF OVERDONE A TAD. IT
BASICALLY MIGRATES SCATTERED CONVECTIVE ELEMENTS INTO OUR SEMO
OZARK COUNTIES TONIGHT. IT DOS NOT MODEL ACCURATELY THE WIDELY
SCATTERED ACTIVITY IN OUR EAST...BUT DOES SUGGEST SIMILAR TREND
THERE INTO THE EARLY EVENING HOURS.
OVER TIME...SYNOPTIC MODELING IS THE SAME...DRAWING FRONT IN AND
THIS WEEKEND WITH PASSAGE AND HIGH POP EVENT. LACKING STRONG
FORCING...IT APPEARS TO BE MAINLY A HEAVY RAIN THREAT...WITH
PERHAPS PULSE MAINLY HEAT OF DAY STORMS BEARING WATCH ON THEIR
INTENSITY. POPS PEAK ALONG/AHEAD OF PASSING BOUNDARY SATURDAY INTO
SATURDAY NIGHT.
ON THE BACK SIDE OF THE FRONT BEGINNING SUNDAY INTO SUNDAY
NIGHT...POPS MAY LINGER BUT DRIER AIR STARTS TO WORK DOWN THE
COLUMN. WE`LL SEE SOME DEW POINTS DROPPING BACK INTO THE 50S THEN
AND EFFECTIVELY THIS WILL WORK TOWARD ENDING POPS FROM NORTHWEST
TO SOUTHEAST WITH TIME.
SUMMER LIKE WARMTH/HUMIDITY 80S/60S CONTINUES UNTIL FROPA...AFTER
WHICH THE MOVE BACK INTO THE 70S/50S COMMENCES SUNDAY-SUNDAY
NIGHT.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 153 PM CDT FRI MAY 29 2015
A WEAK UPPER-LEVEL FLOW PATTERN WILL CONTINUE THROUGH THE LONG
TERM...WHICH SHOULD BECOME MORE FREQUENT AS WE HEAD INTO THE SUMMER
MONTHS. EARLY IN THE WEEK...WEAK TROUGHING OVER THE LOWER OHIO
VALLEY WILL BRING SOMEWHAT COOLER AND DRIER CONDITIONS. BROAD
RIDGING WILL FOLLOW IN THE WAKE OF THE TROUGH FOR MID TO LATE WEEK.
THIS WILL RESULT IN A GRADUAL INCREASE IN WARMTH AND HUMIDITY.
AS FAR AS THE SPECIFICS...MONDAY THROUGH TUESDAY NOW LOOK MAINLY DRY
AND A LITTLE COOLER. THE MODELS HAVE TRENDED DRIER AND A BIT COOLER.
POPS WILL BE REMOVED FOR MUCH OF THE AREA...BUT A SLIGHT CHANCE OF
SHOWERS WILL BE KEPT FOR PARTS OF WESTERN KENTUCKY. WITH THE COOLER
AND DRIER AIR...INSTABILITY LOOKS TOO LIMITED FOR THUNDER. LINGERING
CLOUDS SHOULD KEEP HIGHS IN THE 70S ON MONDAY. EVEN WITH LOTS OF SUN
ON TUESDAY...HIGHS SHOULD GENERALLY BE AROUND 80 DEGREES. AS FOR
OVERNIGHT LOWS...HIGH PRESSURE OVER THE GREAT LAKES WILL BRING DRIER
AIR AND LIGHT WINDS...WHICH SHOULD ALLOW MOST PLACES TO FALL INTO
THE 50S.
WEDNESDAY THROUGH FRIDAY...LOW LEVEL WINDS WILL VEER FROM THE EAST
INTO THE SOUTH AS THE HIGHS RETREATS TO THE EAST COAST. LOW LEVEL
MOISTURE WILL SLOWLY CREEP UP. WITH THE INCREASING MOISTURE WILL
COME A SMALL CHANCE OF DIURNALLY INDUCED SHOWERS AND
STORMS...ESPECIALLY THURSDAY AND FRIDAY. HIGHS WILL INCH BACK INTO
THE LOWER AND MID 80S...AND OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.AVIATION...
ISSUED AT 607 PM CDT FRI MAY 29 2015
PRIOR TO THE EFFECTIVE ISSUANCE OF THE 00Z SATURDAY WFO PAH TAF
FORECAST PACKAGE...A SMALL CLUSTER OF SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO MOVE NORTHWEST OF THE KCGI TAF SITE...SO DID NOT
INCLUDE PRECIPITATION AT THE BEGINNING OF THE FORECAST. THE
OVERALL CLUSTER OF SHOWERS AND THUNDERSTORMS MAY PERSIST BRIEFLY
WITH THE DEVELOPMENT OF A WEAK LOW LEVEL JET...SO ADDED A MENTION
OF RAIN IN THE 03Z-07Z TIME FRAME AT KCGI.
THE BULK OF CONVECTION SHOUSL HOLD OFF UNTIL TOMORROW AFTERNOON.
ATTEMPTED TO KEEP VFR CEILINGS AND VISIBILITIES FOR MOST OF THE
TAF SITES IN PLACE PRIOR TO THE ONSET OF CONVECTION ON SATURDAY.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AVIATION...SMITH
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
330 PM EDT THU MAY 28 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM EDT THU MAY 28 2015
18Z SFC ANALYSIS SHOWS A WEAK PRESSURE PATTERN THROUGH THE AREA -
AWASH IN A WARM AND HUMID AIR MASS. ALOFT - AN MCV IS MOVING
SLOWLY NORTHEAST THROUGH THE CUMBERLAND VALLEY. THIS IS SUPPORTING
A LARGE AREA OF THICK CIRRUS IN THE FORM OF DEBRIS CLOUDS COVERING
THE SOUTHERN PORTION OF THE CWA. THIS HAS ALSO SUPPORTED AN AREA
OF LIGHT RAIN BENEATH THE THICK CLOUDS...LIKEWISE SUPPRESSING
TEMPERATURES KEEPING THEM IN THE LOW TO MID 70S. ON THE FRINGES OF
THIS AREA...THE CLOUDS ARE MORE CUMULIFORM AND TEMPERATURES HAVE
RISEN INTO THE 80S. THESE CONDITIONS ARE MORE CONDUCIVE TO THE
DEVELOPMENT OF STORMS...THOUGH SO FAR IT HAS BEEN SLOW GOING...
DESPITE AN UPTICK IN THE STRENGTH OF SHOWERS ALONG THE VIRGINIA
BORDER. THROUGHOUT THE AREA...WINDS HAVE BEEN LIGHT AND VARIABLE
WHILE DEWPOINTS HOLD IN THE LOW TO MID 60S.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT A MINOR CONVECTIVELY
INDUCED SHORTWAVE LIFTING NORTHEAST THROUGH EASTERN KENTUCKY
DURING THE REST OF THE DAY AND INTO TONIGHT. THIS WAVE IS MOVING
THROUGH GENERALLY HIGH HEIGHTS OVER THE SOUTHEAST PORTION OF THE
NATION. THESE HEIGHTS WILL HOLD THROUGH THE PERIOD...BUT A TROUGH
DOES APPROACH THE WESTERN PORTION OF THE REGION BY SATURDAY
MORNING. OTHERWISE...THE INFLUENCE OF THE MID LEVELS ON THE WX
THROUGH EAST KENTUCKY WILL BE MINIMAL IN COMPARISON TO THE DIURNAL
CYCLE. AS SUCH...HAVE FOLLOWED THE HIGHER RESOLUTION MODELS OF
THE HRRR AND NAM12.
SENSIBLE WEATHER WILL FEATURE CONVECTIVE ACTIVITY WINDING DOWN
THROUGH THE EVENING...THOUGH THE SLOW PROGRESS OF THE MCV MAY
SUSTAIN SOME SHOWERS BENEATH IT THROUGH THE NIGHT. PATCHY FOG...
LOCALLY DENSE...CAN BE ANTICIPATED AGAIN TONIGHT IN LOCATIONS THAT
SEE GOOD CLEARING AND THAT HAD PICKED UP SOME RAIN EARLIER IN THE
DAY. FOR FRIDAY THE ONLY LIMITATION ON THE CONVECTION DEVELOPING
WILL BE A LACK OF A TRIGGER AS THERE SHOULD BE PLENTY OF
INSTABILITY AROUND. THE NAM12 AND ECMWF/GFS DO SHOW A WAVE OF
CONVECTION PASSING THROUGH EASTERN KENTUCKY FRIDAY AFTERNOON
HELPING TO JUSTIFY OUR HIGHER POPS FORECAST THAN THIS AFTERNOON.
SIMILAR TO TONIGHT...EXPECT PARTIAL CLEARING AS THE CONVECTION
WANES ALLOWING FOR PATCHY VALLEY FOG TO FORM AFTER MIDNIGHT AND
LINGER INTO DAWN.
USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS
INTO FRIDAY BEFORE SWITCHING TO THE SUPERBLEND THROUGH 12Z
SATURDAY. MADE SOME MINOR RIDGE TO VALLEY TEMPERATURE DIFFERENCES
FOR LOWS AND HOURLY TEMPS EACH NIGHT. AS FOR POPS...ENDED UP
SIMILAR TO A BLEND OF THE DRIER MAV AND WETTER MET GUIDANCE
THROUGH THE SHORT TERM WITH A MORE EXAGGERATED DIURNAL CYCLE IN
THE HOURLY POPS/WX GRIDS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EDT THU MAY 28 2015
RIDGING WILL DAMPEN OUT A BIT THROUGH THE WEEKEND. A SHORTWAVE
TROUGH WILL PUSH ACROSS THE OHIO RIVER VALLEY ON SATURDAY...WITH A
FRONTAL BOUNDARY SHIFTING SOUTHEAST INTO THE REGION. THIS WILL LEAD
TO INCREASING CHANCES FOR SHOWERS AND STORMS THROUGH THE UPCOMING
WEEKEND. THE BETTER CHANCE FOR LESS ACTIVITY WILL BE SATURDAY...BUT
BY SUNDAY...FRONTAL ZONE WILL BE VIRTUALLY OVERHEAD AND WEATHER
LOOKS VERY UNSETTLED. A WEAK UPPER LEVEL TROUGH WILL THEN DEVELOP
OVER THE LOWER MISSISSIPPI RIVER VALLEY INTO EARLY NEXT WEEK...WITH
SOME WEAK IMPULSES KEEPING THE THREAT FOR SHOWERS AND STORMS GOING
WELL INTO NEXT WEEK. BY WEEKS END...UPPER LEVEL RIDGING WILL BUILD
BACK OVER THE REGION WITH HEIGHTS AGAIN ON THE INCREASE.
HOWEVER...AN AFTERNOON SHOWER AND THUNDERSTORM WILL REMAIN POSSIBLE
BENEATH THE RIDGE AS WE SHOULD HAVE PLENTY OF LOW LEVEL MOISTURE IN
PLACE. HIGHS WILL REMAIN ABOVE NORMAL WELL INTO NEXT WEEK WITH 80S
EXPECTED. LOWS WILL ALSO REMAIN ABOVE NORMAL IN THE 60S. NO REAL
SIGNS OF ANY COOL DOWNS ON THE HORIZON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 230 PM EDT THU MAY 28 2015
HIGH AND MID LEVEL CLOUDS WILL BE THE RULE THROUGH THE TAF PERIOD
WITH DIURNALLY DRIVEN CONVECTION AROUND MAINLY IN THE AFTERNOON
AND EARLY EVENING. HAVE INTRODUCED VCTS FOR THIS THROUGH THE REST
OF THE AFTERNOON AND AGAIN STARTING AT MIDDAY FRIDAY. CANNOT RULE
OUT FOG FOR THE VALLEYS AGAIN TONIGHT...BUT MOST OF THE TAF SITES
SHOULD STAY CLEAR. DID ADD A TEMPO FOR SOME MVFR VIS WITH BR AT
THE SME SITE FOR LATE TONIGHT WHERE RAIN FROM THE PAST DAY MAY
CONTRIBUTE ENOUGH EXTRA MOISTURE FOR ITS DEVELOPMENT. WINDS WILL
REMAIN LIGHT AND GENERALLY FROM THE SOUTH THROUGH THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
230 PM EDT THU MAY 28 2015
.UPDATE...
ISSUED AT 200 PM EDT THU MAY 28 2015
PLENTY OF DEBRIS CLOUDS ASSOCIATED WITH A SLOW MOVING MCV LIFTING
NORTHEAST THROUGH THE CUMBERLAND VALLEY HAVE KEPT THE INSTABILITY
IN CHECK OVER THE AREA LIMITING THUNDERSTORM DEVELOPMENT FOR THE
CWA SO FAR. HOWEVER...ON THE FRINGES OF THE AREA...ALONG THE
VIRGINIA BORDER...ISOLATED THUNDERSTORMS ARE STARTING TO DEVELOP.
EXPECT THESE TO CONTINUE THROUGH THE AFTERNOON WITH A BIT BETTER
COVERAGE BY LATE AFTERNOON...MAINLY OVER THE NORTH AND EAST PARTS
OF THE AREA. WITH THAT SAID...THE HRRR DOES SEEM OVERDONE WITH
ITS ACTIVITY THROUGH THE FIRST PART OF THE EVENING GIVEN THE
CURRENT TRENDS. HAVE TWEAKED THE SKY AND POPS FOR THE CURRENT
CONDITIONS AND TRENDS...AS WELL AS THE T/TD GRIDS. THESE UPDATES
HAVE BEEN SENT TO THE NDFD AND WEN SERVERS.
UPDATE ISSUED AT 1030 AM EDT THU MAY 28 2015
14Z SFC ANALYSIS SHOWS A DIFFUSE BOUNDARY LYING WEST TO EAST
THROUGH EASTERN KENTUCKY WITHIN GENERAL HIGH PRESSURE. ALOFT -
HEIGHTS ARE SLIGHTLY HIGHER THAN NORMAL...BUT THE REMAINS OF A
SHORTWAVE IS MOVING SLOWLY NORTH THROUGH THE AREA...THOUGH
WEAKENING. ON SATELLITE...A DECK OF FAIRLY THICK AND OPAQUE HIGH
CLOUDS ARE FOUND OVER OUR WESTERN FLANK AND SPREADING EAST INTO
THE JKL CWA. THESE CLOUDS WILL LIKELY LIMIT THE INSTABILITY
BUILDING THROUGH THE DAY AND COULD COUNTER ACT THE INFLUENCE OF
THE MID LEVEL WAVE WITH RESPECT TO CONVECTION FOR MUCH OF THE
DAY. WILL ALLOW FOR BETTER SHOWER AND STORM CHANCES LATER IN THE
DAY WHEN THE CLOUDS START TO THIN AND BREAK UP...AND INSOLATION
MORE EFFECTIVELY MAKES IT TO THE SFC. OTHERWISE...TEMPERATURES
ARE RUNNING IN THE UPPER 60S UNDER THE CLOUDS...TO THE LOWER AND
MID 70S WITH SUNSHINE. DEWPOINTS ARE RUNNING IN THE MOIST LOWER
AND MIDDLE 60S THROUGH THE AREA WITH LIGHT WINDS. HAVE UPDATED THE
GRIDS WITH THIS IN MIND...INCLUDED A DELAY TO THE RENEWAL OF
CONVECTION. ALSO FINE TUNED THE HOURLY T/TD GRIDS PER THE LATEST
SHORTBLEND GUIDANCE...OBS...AND TRENDS. THESE UPDATES HAVE BEEN
SENT TO THE NDFD AND WEB SERVERS...ALONG WITH A FRESHENED SET OF
ZONES...MAINLY TO DROP MENTION OF EARLY MORNING VALLEY FOG.
UPDATE ISSUED AT 657 AM EDT THU MAY 28 2015
A FEW RAIN SHOWERS ARE MOVING ACROSS SOME OF OUR FAR EASTERN AND
NORTHEASTERN COUNTIES THIS MORNING. SOME OF THE RAIN SHOWERS THAT
ARE MOVING THROUGH MARTIN AND PIKE COUNTIES HAVE PRODUCED CLOSE TO
AN INCH OF RAIN OVER THE PAST HOUR TO 90 MINUTES. THESE SHOWERS
SHOULD BE OUT OF THE AREA IN THE NEXT HOUR OR SO. ANOTHER AREA OF
RAIN SHOWERS WILL BE MOVING OUT OF CENTRAL TENNESSEE AND INTO THE
SOUTHWESTERN PORTION OF OUR FORECAST AREA IN BY 12Z THIS MORNING.
THIS ACTIVITY WILL GRADUALLY OVERSPREAD THE AREA THROUGH OUT THE
MORNING. BY THIS AFTERNOON SCATTERED SHOWERS AND STORMS ARE
EXPECTED TO POP UP AROUND THE AREA AS WELL. GRAPHICAL NOWCASTS
HAVE BEEN ISSUED TO DEAL WITH ANY RAIN SHOWERS THAT WE HAVE
EXPERIENCED SO FAR THIS MORNING. THE LATEST OBS DATA HAS BEEN
INGESTED INTO THE FORECAST GRIDS TO ESTABLISH NEW TRENDS...BUT
NOTHING THAT WOULD WARRANT ISSUING A NEW SET OF ZONES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 300 AM EDT THU MAY 28 2015
NOT MUCH AGREEMENT AMONGST THE MODELS REGARDING TIMING OF SHOWER
AND STORM INITIATION EARLY TODAY...OVERALL AREAL COVERAGE...AND
DURATION OF PRECIPITATION AFTER DARK THIS EVENING AND OVERNIGHT.
THE LATEST MOS GUIDANCES HAS POPS RANGING FROM NOTHING TO 20 TO 30
PERCENT DEPENDING ON WHICH FORECAST SITE YOU ARE TALKING ABOUT.
THE ONLY FIRM TRIGGER FOR CONVECTIVE ACTIVITY TODAY LOOKS TO BE A
WEAKENING AND ALREADY ILL DEFINED COLD FRONT. WITH A WARM AND
HUMID AIR MASS IN PLACE...HOWEVER...AND SOME LIFT STILL AVAILABLE
ALONG THE FRONT...ISOLATED TO SCATTERED SHOWERS AND STORMS ARE
POSSIBLE AGAIN TODAY THROUGH TOMORROW...WITH THE BULK OF ACTIVITY
OCCURRING DURING THE AFTERNOON AND EARLY EVENING HOURS WHILE PEAK
HEATING IS STILL OCCURRING. TEMPERATURES ARE STILL ON TRACK TO RUN
WELL ABOVE NORMAL TODAY AND TOMORROW DUE TO RELATIVELY UNMODIFIED
WARM AND HUMID AIR MASS THAT IS SETTING ON TOP OF US. HIGHS TODAY
TOMORROW SHOULD HAVE NO TROUBLE MAXING OUT IN THE LOW TO MID
80S...WITH OVERNIGHT LOWS IN THE LOW TO MID 60S ACROSS THE AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 331 AM EDT THU MAY 28 2015
THE WESTERN ATLANTIC RIDGE WILL GET FLATTENED OUT THROUGH EARLY
NEXT WEEK...AS DEEPER TROUGHING SLIDES ACROSS THE U.S./CANADIAN
BORDER. RESIDUAL TROUGHING WILL SWING FROM THE ROCKIES TO ACROSS
THE MISSISSIPPI VALLEY...KEEPING THE UNSETTLED WEATHER CONTINUING
ACROSS THE OHIO AND TENNESSEE VALLEYS. THE BETTER CHANCE POPS WILL
OCCUR FROM SATURDAY THROUGH MONDAY...AS A COLD FRONT GRADUALLY
DROPS SOUTHEAST ACROSS THE REGION AND DAMPENS WITH TIME. BY THE
MIDDLE OF NEXT WEEK...A CUTOFF LOW WILL EMERGE AND DRIFT ALONG THE
LOWER MISSISSIPPI VALLEY...WITH RIDGING RE-ESTABLISHING ITSELF
ACROSS THE SOUTHEASTERN CONUS AND MIDDLE APPALACHIANS. FOR EASTERN
KENTUCKY...THIS WILL MEAN LESS CONVECTIVE COVERAGE...BUT STILL
NOT TOTALLY RAIN-FREE. THE BLENDED GUIDANCE OFFERED A REASONABLE
START TO THE POPS. DID NOT STRAY FAR FROM THE GIVEN VALUES DURING
THE PERIODS OF BETTER FORCING...HOWEVER DID CONTINUE TO UNDERCUT A
BIT DURING THE OVER-ACTIVE MODELED NIGHTTIME PERIODS WITH LESS
FORCING AVAILABLE. TEMPERATURES WILL START OUT ABOVE NORMAL
THROUGH THE FIRST PART OF THE WEEKEND...BEFORE THE PASSING COLD
FRONT COOLS THINGS DOWN A FEW DEGREES TEMPORARILY INTO EARLY NEXT
WEEK. READINGS WILL THEN RETURN TO ABOVE NORMAL BY THE MIDDLE OF
NEXT WEEK...WITH THE INFLUENCE OF THE SOUTHEASTERN CONUS RIDGING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 230 PM EDT THU MAY 28 2015
HIGH AND MID LEVEL CLOUDS WILL BE THE RULE THROUGH THE TAF PERIOD
WITH DIURNALLY DRIVEN CONVECTION AROUND MAINLY IN THE AFTERNOON
AND EARLY EVENING. HAVE INTRODUCED VCTS FOR THIS THROUGH THE REST
OF THE AFTERNOON AND AGAIN STARTING AT MIDDAY FRIDAY. CANNOT RULE
OUT FOG FOR THE VALLEYS AGAIN TONIGHT...BUT MOST OF THE TAF SITES
SHOULD STAY CLEAR. DID ADD A TEMPO FOR SOME MVFR VIS WITH BR AT
THE SME SITE FOR LATE TONIGHT WHERE RAIN FROM THE PAST DAY MAY
CONTRIBUTE ENOUGH EXTRA MOISTURE FOR ITS DEVELOPMENT. WINDS WILL
REMAIN LIGHT AND GENERALLY FROM THE SOUTH THROUGH THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...AR
LONG TERM...GEOGERIAN
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
714 PM CDT FRI MAY 29 2015
.AVIATION...
SCATTERED TSTMS ACROSS SE OK...SW AR...NE TX AND NORTH CENTRAL LA
WILL CONTINUE THROUGHOUT THE EVENING HOURS. EXPECT BRIEF MVFR
CIGS...IFR VSBYS IN HEAVY RAIN WITH MODERATE TO SEVERE TURBULENCE
IN AND AROUND THIS CONVECTION. COVERAGE WILL DECREASE THROUGHOUT
THE EVENING. A SURFACE FRONT WILL CROSS THE AREA FROM THE
NORTHWEST LATER TONIGHT AND EARLY SATURDAY...WITH MOST CONVECTION
ENDING AFTER FRONTAL PASSAGE. SOUTH TO SOUTHWEST SURFACE WIND 6 TO
12 KTS WILL BECOME WEST TO NORTHWEST. AFTER 06Z...MVFR CONDITIONS
DUE TO CIGS AND FOG WILL DEVELOP AHEAD OF THE FRONT...BECOMING VFR
AFTER FROPA. MOST OF THE AREA WILL BE VFR AFTER 16Z SATURDAY...
CONTINUING THROUGH 31/00Z. /14/
&&
.PREV DISCUSSION... /ISSUED 308 PM CDT FRI MAY 29 2015/
DISCUSSION...
WILL KEEP THIS BRIEF AS CONVECTIVE TRENDS NOT TO MENTION PUBLIC
BRIEFINGS CONCERNING RIVER STAGES AND CRESTS WILL NOT ALLOW FOR A
DISSERTATION OF THE SEVEN DAY FORECAST THIS AFTERNOON.
CONVECTION CONTINUES TO DEVELOP IN ADVANCE OF AN MCV WHICH
CONTINUES TO SPIN ACROSS NE TX/SE OK ATTM. THIS CONVECTION IS
EXPECTED TO GROW IN COVERAGE AND INTENSITY PER THE HRRR AND MOVE
EASTWARD THROUGH THIS EVENING. A REMNANT BOUNDARY BOTH AT THE SFC
AND AT THE 8H LEVEL LAYING WEST TO EAST SOMEWHERE IN THE VICINITY
OF THE I-20 CORRIDOR COULD AGAIN BE A FOCUS FOR NOCTURNAL TSTM
DEVELOPMENT...SOME OF WHICH COULD PRODUCE LOCALLY HEAVY RAINFALL.
FOR THIS REASON...HAVE LEFT THE FLASH FLOOD WATCH IN PLACE EVEN
THROUGH WE HAVE BEEN MOSTLY VOID OF ANY RAINFALL IN THE WATCH AREA
THROUGH MUCH OF THE DAY TODAY. COLD FRONT WILL PUSH INTO THE
REGION FROM THE NW ON SATURDAY WITH SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS ONCE AGAIN A GOOD BET DURING THE DAY SATURDAY.
RAIN CHANCES DECREASE FROM NW TO SE BY SUNDAY AS THE UPPER
TROUGH FINALLY KICKS OUT INTO THE TENN VALLEY AND UPPER LEVEL
RIDGING BEGINS TO DOMINATE ACROSS THE INTERMOUNTAIN WEST. HAVE
LOWERED POPS THROUGH MUCH OF NEXT WEEK TO ACCOUNT FOR STRONGER
RIDGING PER THE 12Z ECMWF AS WELL.
PRELIMS TO FOLLOW...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 69 82 66 81 / 60 60 40 40
MLU 69 84 67 82 / 60 60 40 50
DEQ 67 79 64 78 / 60 60 30 20
TXK 68 81 65 79 / 60 60 30 30
ELD 69 82 66 80 / 60 60 40 40
TYR 69 81 65 80 / 60 60 40 20
GGG 69 82 66 80 / 60 60 40 30
LFK 70 85 67 83 / 40 60 40 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR ARZ050-051-
059>061-070-071.
LA...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR LAZ001-002.
OK...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR OKZ077.
TX...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR TXZ096-097-
108>112-124>126-136>138-149>151.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
242 PM CDT THU MAY 28 2015
.DISCUSSION...
CONVECTION LATE THIS AFTERNOON TIED TO INSTABILITY AND RESIDUAL
BOUNDARIES LEFT OVER FROM THE MORNING MCS WHICH MOVED ACROSS THE
MIDDLE RED RIVER VALLEY OF NORTHERN TEXAS AND SOUTHERN OKLAHOMA.
OUTFLOW BOUNDARY CURRENTLY RESIDES FROM NEAR SULPHUR SPRINGS AND
MOUNT PLEASANT TO NEAR TEXARKANA AND EL DORADO ARKANSAS...MOVING
VERY SLOWLY SOUTHWARD. SLIGHTLY STRONGER CAPPING INVERSION IS
INHIBITING STORMS FROM FORMING ALONG THE TX PORTION OF THE
BOUNDARY BUT TEMPERATURES ARE NEAR 90 SOUTH OF THE BOUNDARY ATTM
SO WOULD NOT BE SURPRISED TO SEE A FEW STRONG TO SEVERE
THUNDERSTORMS FORM ON THIS BOUNDARY BEFORE CONVECTION BEGINS TO
DIE OFF LATER THIS EVENING.
VISIBLE SATELLITE IMAGERY SHOWING OUR NEXT WEATHER MAKER TAKING
SHAPE ACROSS THE TX HILL COUNTRY. THIS CONVECTION IN ASSOCIATION
WITH AN UPPER LEVEL TROUGH THAT IS LIKELY TO TRAVERSE ACROSS THE
STATE OF TX OVERNIGHT TONIGHT. SHORT TERM PROGS ARE IN PRETTY GOOD
AGREEMENT WITH THE DEVELOPMENT OF THIS SYSTEM AND ITS PROGRESSION
EASTWARD OVERNIGHT WITH THE EXCEPTION OF THE GFS WHICH FOR SOME
REASON LOOSES IT AFTER SUNRISE ON FRIDAY. THE HRRR SEEMS TO HAVE
THE BEST HANDLE ON THIS CONVECTION AFTER MIDNIGHT APPROACHING THE
I-35 CORRIDOR OF N/C TEXAS AND EVENTUALLY MOVING INTO OUR WESTERN
ZONES DURING THE PREDAWN/DAWN HOURS. THEREFORE...HAVE ORIENTED
HIGHER CHANCE POPS AFTER MIDNIGHT IN THE WEST WITH SLIGHT CHANCE
VARIETY IN THE EAST. ALL PROGS HAVE THIS WELL DEFINED UPPER TROUGH
AXIS IN THE VICINITY OF THE I-35 CORRIDOR TO OUR WEST ON FRIDAY
AND WITH PLENTIFUL MOISTURE IN PLACE NOT TO MENTION DIVERGENT FLOW
ALOFT...HAVE INCREASED POPS TO LIKELY ACROSS OUR WESTERN TWO
THIRDS FOR FRIDAY. THIS TROUGH AXIS SLOWLY MOVES ITS WAY EASTWARD
INTO NE TX/SW AR/NW LA FRI NIGHT/SAT AND STALLS OUT. COLD FRONT AT
THE SFC IN ASSOCIATION WITH THIS UPPER TROUGH MOVES OUR WAY AND
STALLS OUT SAT NIGHT/SUN AS WELL SOMEWHERE ACROSS OUR CWA AND WILL
SERVE AS A FOCUS FOR ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT...
MAINLY ACROSS OUR SOUTHEAST ZONES SUN NIGHT THROUGH EARLY NEXT
WEEK.
THERE CONTINUES TO BE MORE AND MORE CONSISTENCY WITH EACH NEW
MODEL RUN THAT THIS STAGNANT UPPER LEVEL TROUGH WILL BECOME
CUTOFF FROM THE WESTERLIES BY THE EARLY TO MIDDLE PORTION OF NEXT
WEEK. JUST WHERE THIS OCCURS IN RELATION TO OUR VICINITY COULD
RESULT IN A VERY WET WORK WEEK NEXT WEEK...TO ONLY WIDELY
SCATTERED VARIETY STORMS. FOR NOW...WILL KEEP THE EXTENDED POP
GRIDS CONSISTENT WITH PREVIOUS FORECASTS WITH HIGHER POPS ACROSS
OUR EASTERN ZONES NEXT WEEK WITH SLIGHT CHANCE VARIETY IN THE
WEST. IT MUST BE NOTED THAT IF THIS TROUGH CUTS OFF TO OUR
WEST...THEN MUCH HIGHER POPS WOULD BE THE END RESULT FOR A MUCH
LARGER PORTION OF OUR AREA NEXT WEEK.
TEMPERATURES SHOULD BE SLIGHTLY MILDER THIS UPCOMING WEEKEND GIVEN
THE EXPECTED STORM COVERAGE WITH BELOW NORMAL TEMPERATURES THROUGH
AT LEAST THE EARLY PORTION OF NEXT WEEK BEFORE WE BEGIN TO SEE
SOME RECOVERY BY LATE NEXT WEEK.
PRELIMS TO FOLLOW...13.
&&
.PREV DISCUSSION... /ISSUED 100 PM CDT THU MAY 28 2015/
AVIATION...
FOR THE 28/18Z TAFS...SCATTERED CONVECTION ONGOING THIS AFTERNOON
ACROSS THE REGION BUT MOST TERMINALS HAVE DODGED THUS FAR...ASIDE
FROM VCTS AT SHV/TXK. EXPECT ADDITIONAL SHWRS/TSTMS THROUGH THE
REMAINDER OF THE AFTERNOON AND INTO THE EVENING BUT COVERAGE IS
STILL NOT ENOUGH TO WARRANT ANY MORE THAN VCTS ATTM...SO WILL USE
AMENDMENTS IF NECESSARY FOR TSRA. WINDS TO REMAIN RATHER LIGHT AND
SOMEWHAT VARIABLE AT TIMES...WITH A PREDOMINANT SOUTH DIRECTION
FOR MUCH OF THE PERIOD. CLOUDS WILL BE LAYERED WITH INCREASING CU
THIS AFTERNOON ALONG WITH SOME MID AND HIGH CLOUDS MIXED IN AS
WELL. CONVECTIVE DEBRIS CLOUDS WILL LIKELY LINGER OVERNIGHT WITH
LOW STRATUS RETURNING CLOSER TO DAYBREAK ALONG WITH PATCHY FOG AND
REDUCED VSBYS. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 71 86 69 83 / 30 60 50 60
MLU 69 88 69 84 / 30 50 50 60
DEQ 67 82 67 80 / 40 60 50 60
TXK 69 84 68 82 / 30 60 50 60
ELD 67 86 69 82 / 30 50 50 60
TYR 72 83 69 82 / 40 60 50 60
GGG 72 85 69 83 / 40 60 50 60
LFK 71 86 70 86 / 40 60 50 60
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19/13
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1037 AM CDT THU MAY 28 2015
.DISCUSSION...
LEADING EDGE OF COLD POOL ASSOCIATED WITH EASTWARD MIGRATING MCS
HAS NOW MOVED INTO OUR NW ZONES. WHILE IR IMAGERY CONTINUES TO
INDICATE SOME WEAKENING OVER THE PAST COUPLE HOURS...IN THE LAST
HOUR...RETURN HAVE BECOME A LITTLE MORE IMPRESSIVE WITH THE
PORTION OF THE LINE ACROSS MCCURTAIN COUNTY SHOWING A TENDENCY TO
BOW SLIGHTLY. FOR THE UPDATE THIS AFTERNOON...HAVE INCREASED POPS
ACROSS OUR EXTREME NORTHERN ZONES TO ACCOUNT FOR THIS EASTWARD
PROPAGATION.
OTHERWISE...EXPECTING WIDELY SCATTERED TYPE COVERAGE WITH
AFTERNOON HEATING ACROSS JUST ABOUT ANYWHERE ACROSS THE REMAINDER
OF OUR REGION WITH PERHAPS A LITTLE MORE CONCENTRATION ALONG ANY
REMNANT WEST TO EAST OUTFLOW BOUNDARY PRODUCED FROM CONVECTION TO
OUR NORTH THIS MORNING AND A RESIDUAL THERMAL BOUNDARY WHICH HAS
SET UP NORTH TO SOUTH ACROSS NORTHERN LOUISIANA. WILL ALSO NEED TO
WATCH FOR SOME SEABREEZE ACTIVITY COMING NORTH OUT OF SOUTHEAST
TEXAS LATE THIS AFTERNOON...POSSIBLY MOVING INTO OUR E TX ZONES
CLOSER TO 00Z THIS EVENING.
DID NOT MAKE ANY OTHER CHANGES AS FCST MAX TEMPS ARE IN THE
BALLPARK. THE ONLY TROUBLE SPOT MAY BE ACROSS OUR NORTHERN ZONES
WHERE PRESENT CONVECTION RESIDES BUT TEMPERATURE RECOVERY IS
CERTAINLY POSSIBLE LATER THIS AFTERNOON.
UPDATED PACKAGE OUT SHORTLY...13.
&&
.PREV DISCUSSION... /ISSUED 846 AM CDT THU MAY 28 2015/
DISCUSSION...
HAVE SENT OUT A QUICK UPDATE TO ACCOUNT FOR CURRENT RADAR TRENDS
TO OUR NORTHWEST. MCS CONTINUES TO MOVE QUICKLY EASTWARD ACROSS
SOUTHERN OKLAHOMA INTO NORTH CENTRAL TEXAS. IR TRENDS SHOW THAT
CLOUD TOPS HAVE SHOWN A TENDENCY TO WARM OVER THE LAST HOUR OR SO
BUT THE CONVECTION IS VERY CLOSE TO OUR EXTREME NW ZONES SO HAVE
UPDATED THE MORNING GRIDS TO ADD LIKELY POPS IN THIS AREA. ALSO
MENTIONED HEAVY RAIN AND FLASH FLOODING POSSIBLE AS WELL FOR THIS
MORNING.
NO OTHER CHANGES WERE MADE TO THE MORNING PORTION OF THE FORECAST.
WILL ADDRESS ANY AFTERNOON CONCERNS FOR THE REMAINDER OF THE
REGION A LITTLE LATER THIS MORNING.
UPDATED PACKAGE ALREADY SENT...13.
PREV DISCUSSION... /ISSUED 717 AM CDT THU MAY 28 2015/
AVIATION...
MOSTLY VFR WITH A FEW CRATERS SINCE AROUND DAYBREAK...NAMELY KMLU
AND NOW KELD/KLFK. OTHERWISE...JUST A FEW VICINITY SHOWERS
NOW...BUT INCREASING TS COVERAGE AS A FORCING AHEAD OF AN UPSTREAM
CONVECTIVE COMPLEX IS IN ROUTE. OUR SFC WINDS WILL PREVAIL S LESS
THAN 10 KTS. CLIMB WINDS ARE VERY LIGHT 10-25KT ON ASCENT AND ALL
SW/W OVER THE ARKLATEX AERODROME. OUTLOOK IS FOR INCREASING
COVERAGE BOTH DAY AND NIGHT INTO THE WEEKEND. /24/
PREV DISCUSSION... /ISSUED 532 AM CDT THU MAY 28 2015/
DISCUSSION...
ALL IS QUIET FOR THE TIME BEING...ALTHOUGH CONFIDENCE REMAINS
SOMEWHAT LOW IN THE SHORT TERM FORECAST...AND WILL BE DETERMINED
BY TWO FACTORS. THE FIRST BEING THE UPSTREAM MCS APPROACHING THE
MIDDLE RED RIVER VALLEY OF SRN OK/N TX...AND THE SECOND BEING A
WEAK AREA OF MID LEVEL CONVERGENCE THAT WILL SPREAD ENE INTO NE
TX/SW AR/N LA THIS AFTERNOON ALONG WEAK DIRTY RIDGING THAT WILL
TRY AND BUILD NE INTO THE MID-SOUTH REGION INTO THE TN VALLEY.
HOWEVER...ALL BETS WILL BE OFF ON THE LATTER SHOULD THIS MCS
MAINTAIN ITS MOMENTUM AND MOVE INTO THE REGION BY LATE
MORNING/EARLY AFTERNOON. THE 09Z SFC ANALYSIS DOES DEPICT A
DISTINCT SFC THETA-E BNDRY ALONG/JUST S OF THE RED RIVER BEFORE
ARCING SE INTO WRN LA...THUS FOCUSING AN AXIS OF INSTABILITY
WHEREAS MORNING MLCAPES RANGE FROM 1000-1500 J/KG TO THE W OF THIS
BNDRY. THE HRRR DOES INITIALIZE ON THE MCS /ALBEIT 1-2 HOURS
SLOWER/ AND BUILDS IT ESE AND GUSTING OUT AS IT MOVES INTO EXTREME
SE OK/NE TX BETWEEN 15-17Z. GRANTED...IT WILL BE OUTRUNNING THE
SHORTWAVE ENERGY NOW OVER CNTRL NM...BUT THE REMNANTS OF THIS
SYSTEM SHOULD FOCUS SCT CONVECTION OVER AT LEAST THE NRN HALF OF
THE REGION...WHICH MAY INTERACT OF THE WEAK MID LEVEL CONVERGENCE
THAT SHOULD SHIFT E INTO SCNTRL AR/NCNTRL LA THIS AFTERNOON. HAVE
CONCENTRATED BEST POPS OVER EXTREME NE TX/SE OK/SW AR...WITH LOW
CHANCE POPS FARTHER SE OVER NCNTRL LA. DESPITE THE WEAK SHEAR IN
PLACE...CAN/T RULE OUT ISOLATED SVR THIS AFTERNOON AND MODERATE
MLCAPES DEVELOP THIS AFTERNOON WITH HEATING. THE PRESENCE OF THE
WEAK RIDGING ALOFT W OF THE MID LEVEL CONVERGENT AXIS SHOULD HELP
KEEP THE CONVECTION MORE ISOLATED TODAY OVER THE SW SECTIONS OF E
TX.
THE UPPER LEVEL PATTERN WILL QUICKLY CHANGE FRIDAY THROUGH EARLY
NEXT WEEK AS A SHORTWAVE DROPPED SE ACROSS THE NRN GREAT BASIN
BENEATH AN OPENING TROUGH OVER ERN ID...SHIFTS E ALONG THE RED
RIVER VALLEY TONIGHT...THIS IGNITING SCT/NUMEROUS CONVECTION FROM
WCNTRL TX N INTO WRN OK...WITH PERHAPS ANOTHER MCS DEVELOPING AND
SPREADING ESE ACROSS SRN OK/NCNTRL TX. THIS CONVECTION SHOULD
AFFECT NE TX/SE OK/SW AR FRIDAY MORNING...WITH POTENTIAL MESOSCALE
BNDRYS FOCUSING ADDITIONAL SCT CONVECTION FARTHER E AHEAD OF THE
N-S UPPER TROUGH AS IT SETTLES INTO CNTRL OK/TX. HAVE INCREASED
POPS TO LIKELY FOR THE NW THIRD OF THE AREA...WITH HIGH CHANCE
POPS ELSEWHERE...ALTHOUGH MUCH OF THIS CONVECTION MAY BE TIED TO
HEATING AND TEND TO DIMINISH FRIDAY NIGHT. WHILE UPSTREAM WFO/S
HAVE ISSUED FLASH FLOOD WATCHES THIS MORNING FOR TONIGHT/THIS
WEEKEND...CONFIDENCE STILL REMAINS TOO LOW AT THIS POINT IN
REGARDS TO CONVECTION EVOLUTION/COVERAGE AS WELL AS QPF AMOUNTS TO
WARRANT THE ISSUANCE OF A WATCH FOR PORTIONS OF THE REGION ATTM.
HOWEVER...LATER SHIFTS WILL RE-EVALUATE LATER TRENDS/SUBSEQUENT
MODEL RUNS FOR THE NEED FOR ONE LATER TODAY/FRIDAY GIVEN THE STILL
SATURATED GROUNDS. THE AFOREMENTIONED UPPER TROUGH LOOKS TO
BECOME STATIONARY OVER THE REGION THIS WEEKEND BEFORE NOSING
SLOWLY E AND BECOMING ABSORBED IN A SECONDARY TROUGH NOW OVER ERN
ID.
SHOULD SEE PERIODS OF SCT/NUMEROUS CONVECTION DEVELOP THIS
WEEKEND AREAWIDE...AND BECOME PRIMARILY MESOSCALE DRIVEN AS SHEAR
WEAKENS FURTHER BENEATH THE WEAK TROUGH AXIS. HAVE ADDED LIKELY
POPS FOR AREAS ALONG/N OF I-20 SATURDAY...WITH THE PROGS DEPICTING
A WEAK SFC FRONT DRIFTING SE INTO SE OK/EXTREME NE TX/SW AR
SATURDAY NIGHT. THE ECMWF IS A BIT SLOWER WITH THE PROGRESSION OF
THE BNDRY AND IS PREFERRED FOR THIS FORECAST PACKAGE BEFORE
BECOMING STATIONARY SOMEWHERE OVER E TX/N LA BY LATE SUNDAY. DID
KEEP MID TO HIGH CHANCE POPS ALONG/AHEAD OF THIS BNDRY THIS
WEEKEND...TAPERING RAIN CHANCES OFF FROM THE NW BY SUNDAY AS DRIER
AIR ALOFT BEGINS TO ENTRAIN SE BEHIND THE EWD DRIFTING TROUGH
AXIS. BOTH THE GFS/ECMWF CONTINUE TO CLOSE THE TROUGH OFF BY
MONDAY...ALTHOUGH DISCREPANCIES ARISE THEREAFTER...WITH THE GFS
FARTHER W WITH THE CLOSED LOW BECOMING STATIONARY SOMEWHERE
NEAR/JUST W OF THE LOWER MS VALLEY. AGAIN PREFER THE ECMWF
HANDLING OF THE CLOSED LOW...AS IT HAS BEEN PERSISTENT IN RUNS THE
LAST FEW DAYS REMAINING NEAR THE MS RIVER. HOWEVER...GIVEN ITS
PROXIMITY EVEN ON THE NORMALLY SUBSIDENT SIDE...CAN/T REMOVE POPS
FROM THE FORECAST FOR MUCH OF NEXT WEEK AS MAINLY
AFTERNOON/EVENING ISOLATED TO WIDELY SCT CONVECTION SHOULD DEVELOP
EACH DAY...ESPECIALLY OVER SW AR/N LA. ASIDE FROM
CONVECTION/ABUNDANT CLOUD COVER EXPECTED TO KEEP TEMPS SLIGHTLY
BELOW NORMAL THIS WEEKEND...LOOK FOR TEMPS TO RETURN BACK TO
NEAR CLIMO FOR MUCH OF NEXT WEEK AS WE MOVE INTO THE FIRST WEEK OF
JUNE.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 88 72 86 69 / 30 20 50 40
MLU 88 70 88 69 / 30 20 40 30
DEQ 84 68 82 67 / 70 30 60 50
TXK 86 70 84 68 / 50 30 60 50
ELD 86 69 86 69 / 30 20 50 40
TYR 88 72 84 69 / 20 30 50 40
GGG 88 72 84 69 / 20 20 50 40
LFK 90 73 87 71 / 20 20 50 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
13
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
846 AM CDT THU MAY 28 2015
.DISCUSSION...
HAVE SENT OUT A QUICK UPDATE TO ACCOUNT FOR CURRENT RADAR TRENDS
TO OUR NORTHWEST. MCS CONTINUES TO MOVE QUICKLY EASTWARD ACROSS
SOUTHERN OKLAHOMA INTO NORTH CENTRAL TEXAS. IR TRENDS SHOW THAT
CLOUD TOPS HAVE SHOWN A TENDENCY TO WARM OVER THE LAST HOUR OR SO
BUT THE CONVECTION IS VERY CLOSE TO OUR EXTREME NW ZONES SO HAVE
UPDATED THE MORNING GRIDS TO ADD LIKELY POPS IN THIS AREA. ALSO
MENTIONED HEAVY RAIN AND FLASH FLOODING POSSIBLE AS WELL FOR THIS
MORNING.
NO OTHER CHANGES WERE MADE TO THE MORNING PORTION OF THE FORECAST.
WILL ADDRESS ANY AFTERNOON CONCERNS FOR THE REMAINDER OF THE
REGION A LITTLE LATER THIS MORNING.
UPDATED PACKAGE ALREADY SENT...13.
&&
.PREV DISCUSSION... /ISSUED 717 AM CDT THU MAY 28 2015/
AVIATION...
MOSTLY VFR WITH A FEW CRATERS SINCE AROUND DAYBREAK...NAMELY KMLU
AND NOW KELD/KLFK. OTHERWISE...JUST A FEW VICINITY SHOWERS
NOW...BUT INCREASING TS COVERAGE AS A FORCING AHEAD OF AN UPSTREAM
CONVECTIVE COMPLEX IS IN ROUTE. OUR SFC WINDS WILL PREVAIL S LESS
THAN 10 KTS. CLIMB WINDS ARE VERY LIGHT 10-25KT ON ASCENT AND ALL
SW/W OVER THE ARKLATEX AERODROME. OUTLOOK IS FOR INCREASING
COVERAGE BOTH DAY AND NIGHT INTO THE WEEKEND. /24/
PREV DISCUSSION... /ISSUED 532 AM CDT THU MAY 28 2015/
DISCUSSION...
ALL IS QUIET FOR THE TIME BEING...ALTHOUGH CONFIDENCE REMAINS
SOMEWHAT LOW IN THE SHORT TERM FORECAST...AND WILL BE DETERMINED
BY TWO FACTORS. THE FIRST BEING THE UPSTREAM MCS APPROACHING THE
MIDDLE RED RIVER VALLEY OF SRN OK/N TX...AND THE SECOND BEING A
WEAK AREA OF MID LEVEL CONVERGENCE THAT WILL SPREAD ENE INTO NE
TX/SW AR/N LA THIS AFTERNOON ALONG WEAK DIRTY RIDGING THAT WILL
TRY AND BUILD NE INTO THE MID-SOUTH REGION INTO THE TN VALLEY.
HOWEVER...ALL BETS WILL BE OFF ON THE LATTER SHOULD THIS MCS
MAINTAIN ITS MOMENTUM AND MOVE INTO THE REGION BY LATE
MORNING/EARLY AFTERNOON. THE 09Z SFC ANALYSIS DOES DEPICT A
DISTINCT SFC THETA-E BNDRY ALONG/JUST S OF THE RED RIVER BEFORE
ARCING SE INTO WRN LA...THUS FOCUSING AN AXIS OF INSTABILITY
WHEREAS MORNING MLCAPES RANGE FROM 1000-1500 J/KG TO THE W OF THIS
BNDRY. THE HRRR DOES INITIALIZE ON THE MCS /ALBEIT 1-2 HOURS
SLOWER/ AND BUILDS IT ESE AND GUSTING OUT AS IT MOVES INTO EXTREME
SE OK/NE TX BETWEEN 15-17Z. GRANTED...IT WILL BE OUTRUNNING THE
SHORTWAVE ENERGY NOW OVER CNTRL NM...BUT THE REMNANTS OF THIS
SYSTEM SHOULD FOCUS SCT CONVECTION OVER AT LEAST THE NRN HALF OF
THE REGION...WHICH MAY INTERACT OF THE WEAK MID LEVEL CONVERGENCE
THAT SHOULD SHIFT E INTO SCNTRL AR/NCNTRL LA THIS AFTERNOON. HAVE
CONCENTRATED BEST POPS OVER EXTREME NE TX/SE OK/SW AR...WITH LOW
CHANCE POPS FARTHER SE OVER NCNTRL LA. DESPITE THE WEAK SHEAR IN
PLACE...CAN/T RULE OUT ISOLATED SVR THIS AFTERNOON AND MODERATE
MLCAPES DEVELOP THIS AFTERNOON WITH HEATING. THE PRESENCE OF THE
WEAK RIDGING ALOFT W OF THE MID LEVEL CONVERGENT AXIS SHOULD HELP
KEEP THE CONVECTION MORE ISOLATED TODAY OVER THE SW SECTIONS OF E
TX.
THE UPPER LEVEL PATTERN WILL QUICKLY CHANGE FRIDAY THROUGH EARLY
NEXT WEEK AS A SHORTWAVE DROPPED SE ACROSS THE NRN GREAT BASIN
BENEATH AN OPENING TROUGH OVER ERN ID...SHIFTS E ALONG THE RED
RIVER VALLEY TONIGHT...THIS IGNITING SCT/NUMEROUS CONVECTION FROM
WCNTRL TX N INTO WRN OK...WITH PERHAPS ANOTHER MCS DEVELOPING AND
SPREADING ESE ACROSS SRN OK/NCNTRL TX. THIS CONVECTION SHOULD
AFFECT NE TX/SE OK/SW AR FRIDAY MORNING...WITH POTENTIAL MESOSCALE
BNDRYS FOCUSING ADDITIONAL SCT CONVECTION FARTHER E AHEAD OF THE
N-S UPPER TROUGH AS IT SETTLES INTO CNTRL OK/TX. HAVE INCREASED
POPS TO LIKELY FOR THE NW THIRD OF THE AREA...WITH HIGH CHANCE
POPS ELSEWHERE...ALTHOUGH MUCH OF THIS CONVECTION MAY BE TIED TO
HEATING AND TEND TO DIMINISH FRIDAY NIGHT. WHILE UPSTREAM WFO/S
HAVE ISSUED FLASH FLOOD WATCHES THIS MORNING FOR TONIGHT/THIS
WEEKEND...CONFIDENCE STILL REMAINS TOO LOW AT THIS POINT IN
REGARDS TO CONVECTION EVOLUTION/COVERAGE AS WELL AS QPF AMOUNTS TO
WARRANT THE ISSUANCE OF A WATCH FOR PORTIONS OF THE REGION ATTM.
HOWEVER...LATER SHIFTS WILL RE-EVALUATE LATER TRENDS/SUBSEQUENT
MODEL RUNS FOR THE NEED FOR ONE LATER TODAY/FRIDAY GIVEN THE STILL
SATURATED GROUNDS. THE AFOREMENTIONED UPPER TROUGH LOOKS TO
BECOME STATIONARY OVER THE REGION THIS WEEKEND BEFORE NOSING
SLOWLY E AND BECOMING ABSORBED IN A SECONDARY TROUGH NOW OVER ERN
ID.
SHOULD SEE PERIODS OF SCT/NUMEROUS CONVECTION DEVELOP THIS
WEEKEND AREAWIDE...AND BECOME PRIMARILY MESOSCALE DRIVEN AS SHEAR
WEAKENS FURTHER BENEATH THE WEAK TROUGH AXIS. HAVE ADDED LIKELY
POPS FOR AREAS ALONG/N OF I-20 SATURDAY...WITH THE PROGS DEPICTING
A WEAK SFC FRONT DRIFTING SE INTO SE OK/EXTREME NE TX/SW AR
SATURDAY NIGHT. THE ECMWF IS A BIT SLOWER WITH THE PROGRESSION OF
THE BNDRY AND IS PREFERRED FOR THIS FORECAST PACKAGE BEFORE
BECOMING STATIONARY SOMEWHERE OVER E TX/N LA BY LATE SUNDAY. DID
KEEP MID TO HIGH CHANCE POPS ALONG/AHEAD OF THIS BNDRY THIS
WEEKEND...TAPERING RAIN CHANCES OFF FROM THE NW BY SUNDAY AS DRIER
AIR ALOFT BEGINS TO ENTRAIN SE BEHIND THE EWD DRIFTING TROUGH
AXIS. BOTH THE GFS/ECMWF CONTINUE TO CLOSE THE TROUGH OFF BY
MONDAY...ALTHOUGH DISCREPANCIES ARISE THEREAFTER...WITH THE GFS
FARTHER W WITH THE CLOSED LOW BECOMING STATIONARY SOMEWHERE
NEAR/JUST W OF THE LOWER MS VALLEY. AGAIN PREFER THE ECMWF
HANDLING OF THE CLOSED LOW...AS IT HAS BEEN PERSISTENT IN RUNS THE
LAST FEW DAYS REMAINING NEAR THE MS RIVER. HOWEVER...GIVEN ITS
PROXIMITY EVEN ON THE NORMALLY SUBSIDENT SIDE...CAN/T REMOVE POPS
FROM THE FORECAST FOR MUCH OF NEXT WEEK AS MAINLY
AFTERNOON/EVENING ISOLATED TO WIDELY SCT CONVECTION SHOULD DEVELOP
EACH DAY...ESPECIALLY OVER SW AR/N LA. ASIDE FROM
CONVECTION/ABUNDANT CLOUD COVER EXPECTED TO KEEP TEMPS SLIGHTLY
BELOW NORMAL THIS WEEKEND...LOOK FOR TEMPS TO RETURN BACK TO
NEAR CLIMO FOR MUCH OF NEXT WEEK AS WE MOVE INTO THE FIRST WEEK OF
JUNE.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 88 72 86 69 / 30 20 50 40
MLU 88 70 88 69 / 30 20 40 30
DEQ 84 68 82 67 / 70 30 60 50
TXK 86 70 84 68 / 50 30 60 50
ELD 86 69 86 69 / 30 20 50 40
TYR 88 72 84 69 / 20 30 50 40
GGG 88 72 84 69 / 20 20 50 40
LFK 90 73 87 71 / 20 20 50 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
13
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
717 AM CDT THU MAY 28 2015
.AVIATION...
MOSTLY VFR WITH A FEW CRATERS SINCE AROUND DAYBREAK...NAMELY KMLU
AND NOW KELD/KLFK. OTHERWISE...JUST A FEW VICINITY SHOWERS
NOW...BUT INCREASING TS COVERAGE AS A FORCING AHEAD OF AN UPSTREAM
CONVECTIVE COMPLEX IS IN ROUTE. OUR SFC WINDS WILL PREVAIL S LESS
THAN 10 KTS. CLIMB WINDS ARE VERY LIGHT 10-25KT ON ASCENT AND ALL
SW/W OVER THE ARKLATEX AERODROME. OUTLOOK IS FOR INCREASING
COVERAGE BOTH DAY AND NIGHT INTO THE WEEKEND. /24/
&&
.PREV DISCUSSION... /ISSUED 532 AM CDT THU MAY 28 2015/
DISCUSSION...
ALL IS QUIET FOR THE TIME BEING...ALTHOUGH CONFIDENCE REMAINS
SOMEWHAT LOW IN THE SHORT TERM FORECAST...AND WILL BE DETERMINED
BY TWO FACTORS. THE FIRST BEING THE UPSTREAM MCS APPROACHING THE
MIDDLE RED RIVER VALLEY OF SRN OK/N TX...AND THE SECOND BEING A
WEAK AREA OF MID LEVEL CONVERGENCE THAT WILL SPREAD ENE INTO NE
TX/SW AR/N LA THIS AFTERNOON ALONG WEAK DIRTY RIDGING THAT WILL
TRY AND BUILD NE INTO THE MID-SOUTH REGION INTO THE TN VALLEY.
HOWEVER...ALL BETS WILL BE OFF ON THE LATTER SHOULD THIS MCS
MAINTAIN ITS MOMENTUM AND MOVE INTO THE REGION BY LATE
MORNING/EARLY AFTERNOON. THE 09Z SFC ANALYSIS DOES DEPICT A
DISTINCT SFC THETA-E BNDRY ALONG/JUST S OF THE RED RIVER BEFORE
ARCING SE INTO WRN LA...THUS FOCUSING AN AXIS OF INSTABILITY
WHEREAS MORNING MLCAPES RANGE FROM 1000-1500 J/KG TO THE W OF THIS
BNDRY. THE HRRR DOES INITIALIZE ON THE MCS /ALBEIT 1-2 HOURS
SLOWER/ AND BUILDS IT ESE AND GUSTING OUT AS IT MOVES INTO EXTREME
SE OK/NE TX BETWEEN 15-17Z. GRANTED...IT WILL BE OUTRUNNING THE
SHORTWAVE ENERGY NOW OVER CNTRL NM...BUT THE REMNANTS OF THIS
SYSTEM SHOULD FOCUS SCT CONVECTION OVER AT LEAST THE NRN HALF OF
THE REGION...WHICH MAY INTERACT OF THE WEAK MID LEVEL CONVERGENCE
THAT SHOULD SHIFT E INTO SCNTRL AR/NCNTRL LA THIS AFTERNOON. HAVE
CONCENTRATED BEST POPS OVER EXTREME NE TX/SE OK/SW AR...WITH LOW
CHANCE POPS FARTHER SE OVER NCNTRL LA. DESPITE THE WEAK SHEAR IN
PLACE...CAN/T RULE OUT ISOLATED SVR THIS AFTERNOON AND MODERATE
MLCAPES DEVELOP THIS AFTERNOON WITH HEATING. THE PRESENCE OF THE
WEAK RIDGING ALOFT W OF THE MID LEVEL CONVERGENT AXIS SHOULD HELP
KEEP THE CONVECTION MORE ISOLATED TODAY OVER THE SW SECTIONS OF E
TX.
THE UPPER LEVEL PATTERN WILL QUICKLY CHANGE FRIDAY THROUGH EARLY
NEXT WEEK AS A SHORTWAVE DROPPED SE ACROSS THE NRN GREAT BASIN
BENEATH AN OPENING TROUGH OVER ERN ID...SHIFTS E ALONG THE RED
RIVER VALLEY TONIGHT...THIS IGNITING SCT/NUMEROUS CONVECTION FROM
WCNTRL TX N INTO WRN OK...WITH PERHAPS ANOTHER MCS DEVELOPING AND
SPREADING ESE ACROSS SRN OK/NCNTRL TX. THIS CONVECTION SHOULD
AFFECT NE TX/SE OK/SW AR FRIDAY MORNING...WITH POTENTIAL MESOSCALE
BNDRYS FOCUSING ADDITIONAL SCT CONVECTION FARTHER E AHEAD OF THE
N-S UPPER TROUGH AS IT SETTLES INTO CNTRL OK/TX. HAVE INCREASED
POPS TO LIKELY FOR THE NW THIRD OF THE AREA...WITH HIGH CHANCE
POPS ELSEWHERE...ALTHOUGH MUCH OF THIS CONVECTION MAY BE TIED TO
HEATING AND TEND TO DIMINISH FRIDAY NIGHT. WHILE UPSTREAM WFO/S
HAVE ISSUED FLASH FLOOD WATCHES THIS MORNING FOR TONIGHT/THIS
WEEKEND...CONFIDENCE STILL REMAINS TOO LOW AT THIS POINT IN
REGARDS TO CONVECTION EVOLUTION/COVERAGE AS WELL AS QPF AMOUNTS TO
WARRANT THE ISSUANCE OF A WATCH FOR PORTIONS OF THE REGION ATTM.
HOWEVER...LATER SHIFTS WILL RE-EVALUATE LATER TRENDS/SUBSEQUENT
MODEL RUNS FOR THE NEED FOR ONE LATER TODAY/FRIDAY GIVEN THE STILL
SATURATED GROUNDS. THE AFOREMENTIONED UPPER TROUGH LOOKS TO
BECOME STATIONARY OVER THE REGION THIS WEEKEND BEFORE NOSING
SLOWLY E AND BECOMING ABSORBED IN A SECONDARY TROUGH NOW OVER ERN
ID.
SHOULD SEE PERIODS OF SCT/NUMEROUS CONVECTION DEVELOP THIS
WEEKEND AREAWIDE...AND BECOME PRIMARILY MESOSCALE DRIVEN AS SHEAR
WEAKENS FURTHER BENEATH THE WEAK TROUGH AXIS. HAVE ADDED LIKELY
POPS FOR AREAS ALONG/N OF I-20 SATURDAY...WITH THE PROGS DEPICTING
A WEAK SFC FRONT DRIFTING SE INTO SE OK/EXTREME NE TX/SW AR
SATURDAY NIGHT. THE ECMWF IS A BIT SLOWER WITH THE PROGRESSION OF
THE BNDRY AND IS PREFERRED FOR THIS FORECAST PACKAGE BEFORE
BECOMING STATIONARY SOMEWHERE OVER E TX/N LA BY LATE SUNDAY. DID
KEEP MID TO HIGH CHANCE POPS ALONG/AHEAD OF THIS BNDRY THIS
WEEKEND...TAPERING RAIN CHANCES OFF FROM THE NW BY SUNDAY AS DRIER
AIR ALOFT BEGINS TO ENTRAIN SE BEHIND THE EWD DRIFTING TROUGH
AXIS. BOTH THE GFS/ECMWF CONTINUE TO CLOSE THE TROUGH OFF BY
MONDAY...ALTHOUGH DISCREPANCIES ARISE THEREAFTER...WITH THE GFS
FARTHER W WITH THE CLOSED LOW BECOMING STATIONARY SOMEWHERE
NEAR/JUST W OF THE LOWER MS VALLEY. AGAIN PREFER THE ECMWF
HANDLING OF THE CLOSED LOW...AS IT HAS BEEN PERSISTENT IN RUNS THE
LAST FEW DAYS REMAINING NEAR THE MS RIVER. HOWEVER...GIVEN ITS
PROXIMITY EVEN ON THE NORMALLY SUBSIDENT SIDE...CAN/T REMOVE POPS
FROM THE FORECAST FOR MUCH OF NEXT WEEK AS MAINLY
AFTERNOON/EVENING ISOLATED TO WIDELY SCT CONVECTION SHOULD DEVELOP
EACH DAY...ESPECIALLY OVER SW AR/N LA. ASIDE FROM
CONVECTION/ABUNDANT CLOUD COVER EXPECTED TO KEEP TEMPS SLIGHTLY
BELOW NORMAL THIS WEEKEND...LOOK FOR TEMPS TO RETURN BACK TO
NEAR CLIMO FOR MUCH OF NEXT WEEK AS WE MOVE INTO THE FIRST WEEK OF
JUNE.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 88 72 86 69 / 30 20 50 40
MLU 88 70 88 69 / 30 20 40 30
DEQ 84 68 82 67 / 50 30 60 50
TXK 86 70 84 68 / 40 30 60 50
ELD 86 69 86 69 / 30 20 50 40
TYR 88 72 84 69 / 20 30 50 40
GGG 88 72 84 69 / 20 20 50 40
LFK 90 73 87 71 / 20 20 50 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24/15
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
532 AM CDT THU MAY 28 2015
.DISCUSSION...
ALL IS QUIET FOR THE TIME BEING...ALTHOUGH CONFIDENCE REMAINS
SOMEWHAT LOW IN THE SHORT TERM FORECAST...AND WILL BE DETERMINED
BY TWO FACTORS. THE FIRST BEING THE UPSTREAM MCS APPROACHING THE
MIDDLE RED RIVER VALLEY OF SRN OK/N TX...AND THE SECOND BEING A
WEAK AREA OF MID LEVEL CONVERGENCE THAT WILL SPREAD ENE INTO NE
TX/SW AR/N LA THIS AFTERNOON ALONG WEAK DIRTY RIDGING THAT WILL
TRY AND BUILD NE INTO THE MID-SOUTH REGION INTO THE TN VALLEY.
HOWEVER...ALL BETS WILL BE OFF ON THE LATTER SHOULD THIS MCS
MAINTAIN ITS MOMENTUM AND MOVE INTO THE REGION BY LATE
MORNING/EARLY AFTERNOON. THE 09Z SFC ANALYSIS DOES DEPICT A
DISTINCT SFC THETA-E BNDRY ALONG/JUST S OF THE RED RIVER BEFORE
ARCING SE INTO WRN LA...THUS FOCUSING AN AXIS OF INSTABILITY
WHEREAS MORNING MLCAPES RANGE FROM 1000-1500 J/KG TO THE W OF THIS
BNDRY. THE HRRR DOES INITIALIZE ON THE MCS /ALBEIT 1-2 HOURS
SLOWER/ AND BUILDS IT ESE AND GUSTING OUT AS IT MOVES INTO EXTREME
SE OK/NE TX BETWEEN 15-17Z. GRANTED...IT WILL BE OUTRUNNING THE
SHORTWAVE ENERGY NOW OVER CNTRL NM...BUT THE REMNANTS OF THIS
SYSTEM SHOULD FOCUS SCT CONVECTION OVER AT LEAST THE NRN HALF OF
THE REGION...WHICH MAY INTERACT OF THE WEAK MID LEVEL CONVERGENCE
THAT SHOULD SHIFT E INTO SCNTRL AR/NCNTRL LA THIS AFTERNOON. HAVE
CONCENTRATED BEST POPS OVER EXTREME NE TX/SE OK/SW AR...WITH LOW
CHANCE POPS FARTHER SE OVER NCNTRL LA. DESPITE THE WEAK SHEAR IN
PLACE...CAN/T RULE OUT ISOLATED SVR THIS AFTERNOON AND MODERATE
MLCAPES DEVELOP THIS AFTERNOON WITH HEATING. THE PRESENCE OF THE
WEAK RIDGING ALOFT W OF THE MID LEVEL CONVERGENT AXIS SHOULD HELP
KEEP THE CONVECTION MORE ISOLATED TODAY OVER THE SW SECTIONS OF E
TX.
THE UPPER LEVEL PATTERN WILL QUICKLY CHANGE FRIDAY THROUGH EARLY
NEXT WEEK AS A SHORTWAVE DROPPED SE ACROSS THE NRN GREAT BASIN
BENEATH AN OPENING TROUGH OVER ERN ID...SHIFTS E ALONG THE RED
RIVER VALLEY TONIGHT...THIS IGNITING SCT/NUMEROUS CONVECTION FROM
WCNTRL TX N INTO WRN OK...WITH PERHAPS ANOTHER MCS DEVELOPING AND
SPREADING ESE ACROSS SRN OK/NCNTRL TX. THIS CONVECTION SHOULD
AFFECT NE TX/SE OK/SW AR FRIDAY MORNING...WITH POTENTIAL MESOSCALE
BNDRYS FOCUSING ADDITIONAL SCT CONVECTION FARTHER E AHEAD OF THE
N-S UPPER TROUGH AS IT SETTLES INTO CNTRL OK/TX. HAVE INCREASED
POPS TO LIKELY FOR THE NW THIRD OF THE AREA...WITH HIGH CHANCE
POPS ELSEWHERE...ALTHOUGH MUCH OF THIS CONVECTION MAY BE TIED TO
HEATING AND TEND TO DIMINISH FRIDAY NIGHT. WHILE UPSTREAM WFO/S
HAVE ISSUED FLASH FLOOD WATCHES THIS MORNING FOR TONIGHT/THIS
WEEKEND...CONFIDENCE STILL REMAINS TOO LOW AT THIS POINT IN
REGARDS TO CONVECTION EVOLUTION/COVERAGE AS WELL AS QPF AMOUNTS TO
WARRANT THE ISSUANCE OF A WATCH FOR PORTIONS OF THE REGION ATTM.
HOWEVER...LATER SHIFTS WILL RE-EVALUATE LATER TRENDS/SUBSEQUENT
MODEL RUNS FOR THE NEED FOR ONE LATER TODAY/FRIDAY GIVEN THE STILL
SATURATED GROUNDS. THE AFOREMENTIONED UPPER TROUGH LOOKS TO
BECOME STATIONARY OVER THE REGION THIS WEEKEND BEFORE NOSING
SLOWLY E AND BECOMING ABSORBED IN A SECONDARY TROUGH NOW OVER ERN
ID.
SHOULD SEE PERIODS OF SCT/NUMEROUS CONVECTION DEVELOP THIS
WEEKEND AREAWIDE...AND BECOME PRIMARILY MESOSCALE DRIVEN AS SHEAR
WEAKENS FURTHER BENEATH THE WEAK TROUGH AXIS. HAVE ADDED LIKELY
POPS FOR AREAS ALONG/N OF I-20 SATURDAY...WITH THE PROGS DEPICTING
A WEAK SFC FRONT DRIFTING SE INTO SE OK/EXTREME NE TX/SW AR
SATURDAY NIGHT. THE ECMWF IS A BIT SLOWER WITH THE PROGRESSION OF
THE BNDRY AND IS PREFERRED FOR THIS FORECAST PACKAGE BEFORE
BECOMING STATIONARY SOMEWHERE OVER E TX/N LA BY LATE SUNDAY. DID
KEEP MID TO HIGH CHANCE POPS ALONG/AHEAD OF THIS BNDRY THIS
WEEKEND...TAPERING RAIN CHANCES OFF FROM THE NW BY SUNDAY AS DRIER
AIR ALOFT BEGINS TO ENTRAIN SE BEHIND THE EWD DRIFTING TROUGH
AXIS. BOTH THE GFS/ECMWF CONTINUE TO CLOSE THE TROUGH OFF BY
MONDAY...ALTHOUGH DISCREPANCIES ARISE THEREAFTER...WITH THE GFS
FARTHER W WITH THE CLOSED LOW BECOMING STATIONARY SOMEWHERE
NEAR/JUST W OF THE LOWER MS VALLEY. AGAIN PREFER THE ECMWF
HANDLING OF THE CLOSED LOW...AS IT HAS BEEN PERSISTENT IN RUNS THE
LAST FEW DAYS REMAINING NEAR THE MS RIVER. HOWEVER...GIVEN ITS
PROXIMITY EVEN ON THE NORMALLY SUBSIDENT SIDE...CAN/T REMOVE POPS
FROM THE FORECAST FOR MUCH OF NEXT WEEK AS MAINLY
AFTERNOON/EVENING ISOLATED TO WIDELY SCT CONVECTION SHOULD DEVELOP
EACH DAY...ESPECIALLY OVER SW AR/N LA. ASIDE FROM
CONVECTION/ABUNDANT CLOUD COVER EXPECTED TO KEEP TEMPS SLIGHTLY
BELOW NORMAL THIS WEEKEND...LOOK FOR TEMPS TO RETURN BACK TO
NEAR CLIMO FOR MUCH OF NEXT WEEK AS WE MOVE INTO THE FIRST WEEK OF
JUNE.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 88 72 86 69 / 30 20 50 40
MLU 88 70 88 69 / 30 20 40 30
DEQ 84 68 82 67 / 50 30 60 50
TXK 86 70 84 68 / 40 30 60 50
ELD 86 69 86 69 / 30 20 50 40
TYR 88 72 84 69 / 20 30 50 40
GGG 88 72 84 69 / 20 20 50 40
LFK 90 73 87 71 / 20 20 50 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS CARIBOU ME
931 PM EDT FRI MAY 29 2015
.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH THE REGION FROM THE WEST ON
SATURDAY AND CROSS THE AREA SATURDAY NIGHT INTO SUNDAY MORNING.
COOLER AND DRIER WEATHER WILL WORK INTO THE REGION LATER SUNDAY
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
930 PM UPDATE...
QUICK UPDATE TO BRING T/TD VALUES IN LINE WITH CURRENT OBS. THINGS
ARE STILL A GO REGARDING FOG DVLPMNT TONIGHT OVR COASTAL ZONES
AND SPREADING NORTH ON SRLY FLOW BLO STRONG SUBSIDENCE INVERSION
AS EVIDENCED BY 00Z RAOB.
PREV DISCUSSION BLO...
CONCERNS WILL BE LOW CLOUDS AND FOG TONIGHT AND CONVECTIVE
POTENTIAL FOR SATURDAY.
FOR TONIGHT...STARTING OUT CLEAR AND COOL, BUT A SOUTHERLY FLOW
SETTING UP LATER ON WILL BEGIN TO BRING A HUMID AIRMASS INTO THE
REGION. ALONG W/THIS HUMID AIRMASS WILL BE LOW CLOUDS AND FOG.
SOME OF THE SHORT RANGE GUIDANCE(NAM AND THE HRRR 3KM) HINTED AT
SOME LIGHT PRECIP IN THE FORM OF RAIN SHOWERS OR DRIZZLE PUSHING
IN FROM THE GULF OF MAINE WATERS LATER TONIGHT. SINCE THE
SOUTHERLY FLOW APPEARS TO TO BE RESTRICTED BELOW 925MBS AND VERY
DRY ABOVE THE THAT LAYER, THINKING HERE IS THAT SHOWERS/DRIZZLE
WILL BE LIMITED/SPOTTY AT BEST. ATTM, DECIDED TO HIT THE FOG
HARDER FOR THE INTERIOR DOWNEAST REGION AND THE COAST OVERNIGHT
INTO EARLY SATURDAY MORNING. NORTHERN AND CENTRAL AREAS WILL SEE
PATCHY FOG W/THAT LOW CLOUD DECK PUSHING NORTHWARD.
FOR SATURDAY...A COLD FRONT IS FORECAST TO APPROACH THE REGION
FROM QUEBEC. LOW CLOUDS AND FOG WILL BEGIN TO LIFT AND BURN OFF BY
MID TO LATE MORNING. SOME HEATING WILL TAKE PLACE ESPECIALLY
ACROSS THE WESTERN PORTION OF THE CWA W/THIS AREA DESTABILIZING
QUICKLY BY THE AFTERNOON. FURTHER EAST, CLOUDS COULD HANG ON FOR
A WHILE KEEPING LLVLS STABLE FOR A TIME, BEFORE THINGS BREAKOUT
AND DESTABILIZATION TAKES PLACE. DEWPOINTS ARE FORECAST TO SHOOT
THROUGH THE 50S AND GO WELL INTO MID 60S BY LATE IN THE DAY. THE
NAM12 AND GFS SOUNDINGS SHOW SB CAPES HITTING 700-1200 JOULES BY
LATE SATURDAY AFTERNOON AND LIS DROPPING TO -2 OR SO AND 0-6KM
SHEAR OF 40 KTS. FLOW TURNS TO THE SW THROUGH THE COLUMN W/SOME
DIRECTIONAL SHEAR NOTED IN THE LLVLS ESPECIALLY ACROSS THE FAR N
AND W. THERE IS ALSO A GOOD MID LEVEL JET OF 50 KTS FORECAST TO
BE HITTING THE REGION LATER IN THE DAY WHICH WOULD ENHANCE THE
FORCING. FREEZING LEVELS ARE FORECAST TO BE AROUND 12K FT. SO HAIL
IS A POSSIBILITY. THE LIMITING FACTOR IS THAT LAPSE RATES ARE NOT
OVERLY IMPRESSIVE ACROSS THE CWA, ESPECIALLY IN THE MID LEVELS.
THE BEST LAPSE RATES RUN THROUGH QUEBEC AHEAD OF THE APPROACHING
FRONT. AFTER COLLABORATING W/GYX, DECIDED TO ADD ENHANCED WORDING
FOR TSTMS MAINLY WIND GUSTS AND HAIL. SPC HAS THE WESTERN AND
NORTHERN AREAS IN A MARGINAL RISK FOR SOME ISOLATED SEVERE STORMS.
DAYTIME HIGH TEMPS ARE FORECAST TO BE IN THE 80S ACROSS THE NORTH
AND WEST WHILE THE DOWNEAST AND COAST WILL BE COOLER W/A SSW FLOW.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SHOWERS AND A FEW THUNDERSTORMS WILL BE ONGOING ACROSS THE REGION
EARLY SATURDAY EVENING AS THE COLD FRONT PUSHES ACROSS THE AREA.
WILL MENTION POSSIBILITY OF GUSTY WINDS AND SMALL HAIL ACROSS
WESTERN AREAS EARLY SATURDAY EVENING. THE COLD FRONT SHOULD BE TO
THE DOWN EAST COAST OF MAINE BY DAYBREAK SUNDAY. EXPECT A
CONTINUED CHANCE FOR SHOWERS SATURDAY NIGHT ESPECIALLY ACROSS
CENTRAL AND DOWN EAST AREAS. HIGH PRESSURE WILL START TO BUILD IN
FROM THE NORTHWEST DURING SUNDAY. EXPECT THE BEST WEATHER TO BE
FOUND ACROSS NORTHERN MOST MAINE CLOSER TO THE CENTER OF THE HIGH.
HOWEVER, CLOUDS AND A FEW SHOWERS CAN BE EXPECTED TO LINGER ACROSS
DOWN EAST MAINE. EXPECT MAINLY CLEAR SKIES ACROSS THE NORTH SUNDAY
AND PARTLY CLOUDY SKIES ACROSS CENTRAL AND DOWN EAST AREAS. LOW
TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S TO AROUND 40
ACROSS NORTHERN AREAS. THERE IS EVEN THE POSSIBILITY FOR SOME
PATCHY FROST ACROSS THE COLDER VALLEY LOCATIONS OF NORTHERN AND
NORTHWEST MAINE BUT WONT MENTION QUITE YET. MONDAY IS SHAPING UP
AS A MAINLY DRY DAY ACROSS MOST OF THE AREA AS HIGH PRESSURE
BUILDS IN FROM THE NORTH.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH MONDAY NIGHT AND THEN
MOVE INTO THE CANADIAN MARITIMES BY TUESDAY. LOW PRESSURE MOVING
UP FROM THE SOUTH COULD BRING SOME RAIN INTO THE REGION LATER
MONDAY AND INTO TUESDAY. HIGH TEMPERATURES ON TUESDAY ARE EXPECTED
TO BE BELOW NORMAL WITH MORE IN THE WAY OF CLOUD COVER AND
EASTERLY FLOW. LOW PRESSURE WILL BEGIN TO MOVE AWAY DURING
WEDNESDAY WITH IMPROVING CONDITIONS EXPECTED FOR MID TO LATE WEEK.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR INTO EARLY TONIGHT AND THEN CONDITIONS ARE EXPECTED
TO GO DOWN TO MVFR AND EVEN IFR AFTER MIDNIGHT INTO SATURDAY
MORNING. NORTHERN TERMINALS WILL CLEAR OUT BY MID MORNING ON
SATURDAY. KBGR AND KBHB WILL BE SLOWER TO CLEAR OUT DUE TO THE
SOUTHERLY FLOW.
SHORT TO LONG TERM: MVFR/IFR CONDITIONS ARE POSSIBLE IN SHOWERS
AND TSTMS SATURDAY NIGHT ESPECIALLY DOWN EAST AREAS. EXPECT VFR
ACROSS THE NORTH AND MVFR/IFR CONDITIONS EARLY SUNDAY IMPROVING TO
VFR ALL AREAS LATER SUNDAY. VFR SUNDAY NIGHT AND INTO MONDAY.
MVFR/IFR CONDITIONS POSSIBLE MONDAY NIGHT THROUGH MID WEEK IN RAIN
AND LOW CLOUDS.
&&
.MARINE...
NEAR TERM: NO HEADLINES WILL BE NEEDED ON THE WATERS THROUGH
MIDDAY SATURDAY. THINGS WILL CHANGE HOWEVER BY LATE AFTERNOON AS
THE GRADIENT TIGHTENS AHEAD OF THE APPROACHING COLD FRONT. DECIDED
TO INCREASE THE WIND SPEEDS TO 25 KTS ESPECIALLY W/THE GUSTS.
SEAS WILL COME UP AS WELL APPROACHING 5-6 FT ESPECIALLY OVER THE
OUTER ZONES BY 6 PM OR SO. FOG TONIGHT INTO EARLY SATURDAY
AFTERNOON WILL LEAD TO TRICKY NAVIGATION AS VSBYS COULD GO DOWN
BELOW 1 NM.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE SATURDAY
EVENING. WINDS AND SEAS MAY THEN INCREASE TO SCA LEVELS BY MID
WEEK.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM SATURDAY TO 6 AM EDT SUNDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...FARRAR
AREA FORECAST DISCUSSION
NWS GRAY ME
909 PM EDT FRI MAY 29 2015
.SYNOPSIS...
HIGH PRESSURE WILL RETURN TODAY AND MOVE OFF THE COAST OVER THE
WEEKEND ALLOWING A WARM AND HUMID SOUTHWEST FLOW TO RETURN.
ANOTHER COLD FRONT CROSSES THE REGION SUNDAY MORNING.
COOL...CANADIAN HIGH PRESSURE WILL BUILD BACK OVER THE REGION
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
9 PM UPDATE: HAVE ISSUED A DENSE FOG ADVSRY FOR ALL MAINE COASTAL
AREAS AND MOST ADJACENT INLAND AREAS AS WELL. A WIDESPREAD AREA OF
DENSE FOG HAD DEVEPED ALONG THE COAST AND HAD PUSHED INLAND. THIS
SHOULD CONTINUE THE REST OF THE NIGHT AS THE LIGHT ONSHORE FLOW
CONTINUES.
720 PM UPDATE: OCEAN STRATUS/FOG HAS SPREAD FURTHER INLAND TO THE
ADJACENT COASTAL AREAS AT THIS TIME. MINOR ADJUSTMENT FOR
PLACEMENT OF LOW CLOUDS AND FOG FURTHER INLAND. ALSO MINOR TWEAKS
TO TEMPS BASED ON LATEST OBS.
PREVIOUS DISCUSSION:
MAIN FORECAST PROBLEM WILL BE MARINE STRATUS QUICKLY APPROACHING
THE COAST. HI-RES MODEL GUIDANCE ACTUALLY HAS A VERY GOOD HANDLE
ON THE CURRENT DEPICTION BASED ON VISIBLE SATELLITE. LEANING
HEAVILY ON THE NARRE AND HRRR FOR TIMING AND COVERAGE FOR THE
OVERNIGHT PERIOD. COASTAL ME...ESPECIALLY NEAR KPWM WILL SEE
STRATUS SOONEST...WITH ALL COASTAL AREAS LIKELY SEEING LOW CIGS BY
00Z. THRU THE NIGHT THIS WILL CREEP INLAND...AND SHOULD ROUGHLY
MATCH THE CURRENT SEA BREEZE FRONT OUTLINE. WINDS SHIFTING TO SWLY
WILL KEEP STRATUS CONFINED TO MAINLY THE GREAT BAY AREA AND E IN
SERN NH...WHILE ALLOWING IT TO PUSH AS FAR INLAND AS KAUG AND KWVL
IN CENTRAL ME.
WHILE CONFIDENCE IS HIGH IN LOW CLOUDS...CONFIDENCE IS SOMEWHAT
LOWER IN FOG AND DRIZZLE. THERE ARE SOME SIGNS BASED ON FORECAST
SOUNDINGS THAT THIS COULD DEVELOP OVERNIGHT. HRRR IS AGGRESSIVE ON
VSBYS BELOW 1/2 SM...WHILE NARRE IS A LITTLE MORE UP IN THE AIR.
SREF VSBYS PROBABILITIES OF GREATER THAN 80 PERCENT FOR LESS THAN
1 SM VSBY POINT TOWARDS SOME FOG MORE LIKELY THAT NOT. SO WILL
HAVE AREAS OF FOG IN THE GRIDS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
GUSTY SW FLOW DEVELOPS AHEAD OF A SLOWLY APPROACHING COLD FRONT
SAT. THERE IS SUFFICIENT SHEAR FOR ORGANIZED STORMS ALONG THE
FRONT...BUT IT WILL DELAY IN REACHING THE FORECAST AREA. SREF
CALIBRATED SEVERE TSTM PROBABILITIES PEAK AROUND 21Z ACROSS THE
FAR NRN ZONES. ENVIRONMENT LOOKS FAIR ACROSS THIS AREA...SO WILL
ADD GUSTY WINDS TO THESE ZONES...AND DELAY TSTMS FOR COAST UNTIL
OVERNIGHT. THE OTHER THREAT TO WATCH WILL BE FLASH FLOODING. PWAT
VALUES WILL BE RUNNING HIGHER THAN NORMAL...AND SLOW FRONTAL
MOVEMENT COUPLED WITH TRAINING STORMS COULD YIELD SOME WATER
ISSUES. LOSS OF DAYTIME HEATING SHOULD HELP ANY STORMS TO WEAKEN
AND BECOME MORE SCATTERED...BUT A RENEWAL OF DEVELOPMENT IS
POSSIBLE EARLY SUN AS THE DAY HEATS UP AGAIN.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
POSITIVELY TILTED SHORTWAVE TROUGH PUSHES THE COLD FRONT THE
REMAINDER OF THE WAY OFFSHORE SUNDAY MORNING WITH SHOWERS COMING
TO AN END IN THE EARLY AFTERNOON. DENSE HIGH PRESSURE TO OUR NORTH
MAKES LITTLE HEADWAY SOUTH HOWEVER AS ANOTHER WAVE OF LOW PRESSURE
MOVES ALONG THE OFFSHORE FRONT. LINGERING CLOUDS AND COOLER
CANADIAN AIR MOVING IN WILL KEEP THE MOUNTAINS COOL (MID 50S)
WHILE MUCH OF THE COASTAL PLAIN CLEARS OUT AND WARMS INTO THE
UPPER 60S ON SUNDAY. MONDAY AND TUESDAY WILL GENERALLY WARM INTO
THE 60S.
THE PROXIMITY OF OFFSHORE FRONTAL SYSTEM AS WELL AS A STEADY
STREAM OF SHORT WAVE ENERGY WILL KEEP A CHANCE OF SHOWERS OVER
SOUTHERN AND COASTAL SECTIONS OF NH AND MAINE THROUGH MONDAY.
THERE IS LITTLE INSTABILITY TO BE HAD BUT THERE MAY BE SOME
LIGHTNING OFFSHORE. FOLLOWING THIS A STOUT CUTOFF SHORT WAVE MOVES
TOWARDS THE AREA TUESDAY INTO WEDNESDAY MORNING ON NEARLY ZONAL
FLOW INCREASING RAIN CHANCES ACROSS THE ENTIRE AREA. HIGH PRESSURE
BUILDS IN BEHIND THIS SYSTEM BRINGING DRY AND WARM CONDITIONS
THURSDAY AND FRIDAY.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...WIDESPREAD IFR/LIFR IS EXPECTED TONIGHT FOR COASTAL
TERMINALS AS MARINE STRATUS INVADES THE AREA. BETWEEN 21 AND 00Z
MOST SITES SHOULD BE IFR OR LOWER. KAUG MAY TAKE A COUPLE EXTRA
HOURS FOR LOW CIGS TO WORK INLAND...BUT BY 03Z IFR IS EXPECTED.
LOW CIGS PERSIST INTO SAT MORNING BEFORE LIFTING. GUSTY SW WINDS
AROUND 20 KTS POSSIBLE SAT AFTERNOON. TSTMS ARE POSSIBLE LATE SAT
INTO SUN FOR ALL TERMINALS. HIGHEST CONFIDENCE FOR TSTMS IS FOR
KHIE SAT EVENING.
LONG TERM...IMPROVING CONDITIONS SUNDAY WITH PERIODS OF MVFR IN
SHOWERS ALONG THE COAST CONTINUING THROUGH WEDNESDAY.
&&
.MARINE...
SHORT TERM...SW RETURN FLOW WILL INCREASE SAT. COOL WATERS SHOULD
LIMIT THE AMOUNT OF MIXING OF THE STRONGEST WINDS TO THE
SURFACE...BUT SUSTAINED FLOW SHOULD BUILD SEAS ABOVE 5 FT BY LATE
SAT. OCCASIONAL GUSTS TO 25 KTS ARE NOT OUT OF THE QUESTION
EITHER.
LONG TERM...WAVES DROP BELOW SCA CRITERIA SUNDAY MORNING. HIGH
SEAS RETURN MONDAY EVENING THROUGH TUESDAY NIGHT AS A TIGHT
PRESSURE GRADIENT SETS UP OVER THE WATERS.
&&
.FIRE WEATHER...
INCREASING HUMIDITY AND SOUTHWESTERLY BREEZES
WILL LEAD TO LATE AFTERNOON SHOWERS AND THUNDERSTORMS SATURDAY
AFTERNOON AND NIGHT. WETTING RAINS WILL BE MOST LIKELY IN THE
MOUNTAINS SATURDAY EVENING AND OVERNIGHT. THE AREAS NEAR THE COAST
WILL BE MORE LIKELY TO SEE WETTING RAINS SUNDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...DENSE FOG ADVISORY UNTIL 6 AM EDT SATURDAY FOR MEZ019>028.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
728 PM EDT FRI MAY 29 2015
.SYNOPSIS...
HIGH PRESSURE WILL RETURN TODAY AND MOVE OFF THE COAST OVER THE
WEEKEND ALLOWING A WARM AND HUMID SOUTHWEST FLOW TO RETURN.
ANOTHER COLD FRONT CROSSES THE REGION SUNDAY MORNING.
COOL...CANADIAN HIGH PRESSURE WILL BUILD BACK OVER THE REGION
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
720 PM UPDATE: OCEAN STRATUS/FOG HAS SPREAD FURTHER INLAND TO THE
ADJACENT COASTAL AREAS AT THIS TIME. MINOR ADJUSTMENT FOR
PLACEMENT OF LOW CLOUDS AND FOG FURTHER INLAND. ALSO MINOR TWEAKS
TO TEMPS BASED ON LATEST OBS.
PREVIOUS DISCUSSION:
MAIN FORECAST PROBLEM WILL BE MARINE STRATUS QUICKLY APPROACHING
THE COAST. HI-RES MODEL GUIDANCE ACTUALLY HAS A VERY GOOD HANDLE
ON THE CURRENT DEPICTION BASED ON VISIBLE SATELLITE. LEANING
HEAVILY ON THE NARRE AND HRRR FOR TIMING AND COVERAGE FOR THE
OVERNIGHT PERIOD. COASTAL ME...ESPECIALLY NEAR KPWM WILL SEE
STRATUS SOONEST...WITH ALL COASTAL AREAS LIKELY SEEING LOW CIGS BY
00Z. THRU THE NIGHT THIS WILL CREEP INLAND...AND SHOULD ROUGHLY
MATCH THE CURRENT SEA BREEZE FRONT OUTLINE. WINDS SHIFTING TO SWLY
WILL KEEP STRATUS CONFINED TO MAINLY THE GREAT BAY AREA AND E IN
SERN NH...WHILE ALLOWING IT TO PUSH AS FAR INLAND AS KAUG AND KWVL
IN CENTRAL ME.
WHILE CONFIDENCE IS HIGH IN LOW CLOUDS...CONFIDENCE IS SOMEWHAT
LOWER IN FOG AND DRIZZLE. THERE ARE SOME SIGNS BASED ON FORECAST
SOUNDINGS THAT THIS COULD DEVELOP OVERNIGHT. HRRR IS AGGRESSIVE ON
VSBYS BELOW 1/2 SM...WHILE NARRE IS A LITTLE MORE UP IN THE AIR.
SREF VSBYS PROBABILITIES OF GREATER THAN 80 PERCENT FOR LESS THAN
1 SM VSBY POINT TOWARDS SOME FOG MORE LIKELY THAT NOT. SO WILL
HAVE AREAS OF FOG IN THE GRIDS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
GUSTY SW FLOW DEVELOPS AHEAD OF A SLOWLY APPROACHING COLD FRONT
SAT. THERE IS SUFFICIENT SHEAR FOR ORGANIZED STORMS ALONG THE
FRONT...BUT IT WILL DELAY IN REACHING THE FORECAST AREA. SREF
CALIBRATED SEVERE TSTM PROBABILITIES PEAK AROUND 21Z ACROSS THE
FAR NRN ZONES. ENVIRONMENT LOOKS FAIR ACROSS THIS AREA...SO WILL
ADD GUSTY WINDS TO THESE ZONES...AND DELAY TSTMS FOR COAST UNTIL
OVERNIGHT. THE OTHER THREAT TO WATCH WILL BE FLASH FLOODING. PWAT
VALUES WILL BE RUNNING HIGHER THAN NORMAL...AND SLOW FRONTAL
MOVEMENT COUPLED WITH TRAINING STORMS COULD YIELD SOME WATER
ISSUES. LOSS OF DAYTIME HEATING SHOULD HELP ANY STORMS TO WEAKEN
AND BECOME MORE SCATTERED...BUT A RENEWAL OF DEVELOPMENT IS
POSSIBLE EARLY SUN AS THE DAY HEATS UP AGAIN.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
POSITIVELY TILTED SHORTWAVE TROUGH PUSHES THE COLD FRONT THE
REMAINDER OF THE WAY OFFSHORE SUNDAY MORNING WITH SHOWERS COMING
TO AN END IN THE EARLY AFTERNOON. DENSE HIGH PRESSURE TO OUR NORTH
MAKES LITTLE HEADWAY SOUTH HOWEVER AS ANOTHER WAVE OF LOW PRESSURE
MOVES ALONG THE OFFSHORE FRONT. LINGERING CLOUDS AND COOLER
CANADIAN AIR MOVING IN WILL KEEP THE MOUNTAINS COOL (MID 50S)
WHILE MUCH OF THE COASTAL PLAIN CLEARS OUT AND WARMS INTO THE
UPPER 60S ON SUNDAY. MONDAY AND TUESDAY WILL GENERALLY WARM INTO
THE 60S.
THE PROXIMITY OF OFFSHORE FRONTAL SYSTEM AS WELL AS A STEADY
STREAM OF SHORT WAVE ENERGY WILL KEEP A CHANCE OF SHOWERS OVER
SOUTHERN AND COASTAL SECTIONS OF NH AND MAINE THROUGH MONDAY.
THERE IS LITTLE INSTABILITY TO BE HAD BUT THERE MAY BE SOME
LIGHTNING OFFSHORE. FOLLOWING THIS A STOUT CUTOFF SHORT WAVE MOVES
TOWARDS THE AREA TUESDAY INTO WEDNESDAY MORNING ON NEARLY ZONAL
FLOW INCREASING RAIN CHANCES ACROSS THE ENTIRE AREA. HIGH PRESSURE
BUILDS IN BEHIND THIS SYSTEM BRINGING DRY AND WARM CONDITIONS
THURSDAY AND FRIDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...WIDESPREAD IFR/LIFR IS EXPECTED TONIGHT FOR COASTAL
TERMINALS AS MARINE STRATUS INVADES THE AREA. BETWEEN 21 AND 00Z
MOST SITES SHOULD BE IFR OR LOWER. KAUG MAY TAKE A COUPLE EXTRA
HOURS FOR LOW CIGS TO WORK INLAND...BUT BY 03Z IFR IS EXPECTED.
LOW CIGS PERSIST INTO SAT MORNING BEFORE LIFTING. GUSTY SW WINDS
AROUND 20 KTS POSSIBLE SAT AFTERNOON. TSTMS ARE POSSIBLE LATE SAT
INTO SUN FOR ALL TERMINALS. HIGHEST CONFIDENCE FOR TSTMS IS FOR
KHIE SAT EVENING.
LONG TERM...IMPROVING CONDITIONS SUNDAY WITH PERIODS OF MVFR IN
SHOWERS ALONG THE COAST CONTINUING THROUGH WEDNESDAY.
&&
.MARINE...
SHORT TERM...SW RETURN FLOW WILL INCREASE SAT. COOL WATERS SHOULD
LIMIT THE AMOUNT OF MIXING OF THE STRONGEST WINDS TO THE
SURFACE...BUT SUSTAINED FLOW SHOULD BUILD SEAS ABOVE 5 FT BY LATE
SAT. OCCASIONAL GUSTS TO 25 KTS ARE NOT OUT OF THE QUESTION
EITHER.
LONG TERM...WAVES DROP BELOW SCA CRITERIA SUNDAY MORNING. HIGH
SEAS RETURN MONDAY EVENING THROUGH TUESDAY NIGHT AS A TIGHT
PRESSURE GRADIENT SETS UP OVER THE WATERS.
&&
.FIRE WEATHER...
INCREASING HUMIDITY AND SOUTHWESTERLY BREEZES
WILL LEAD TO LATE AFTERNOON SHOWERS AND THUNDERSTORMS SATURDAY
AFTERNOON AND NIGHT. WETTING RAINS WILL BE MOST LIKELY IN THE
MOUNTAINS SATURDAY EVENING AND OVERNIGHT. THE AREAS NEAR THE COAST
WILL BE MORE LIKELY TO SEE WETTING RAINS SUNDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1246 AM EDT THU MAY 28 2015
.SYNOPSIS...
A STRONG SUBTROPICAL RIDGE WILL REMAIN OFF THE EAST COAST THROUGH
THE REMAINDER OF THE WEEK BRINGING A WARM AND HUMID FLOW OF AIR
TO OUR REGION THROUGH SATURDAY. A STRONG COLD FRONT WILL CROSS
THE REGION SATURDAY NIGHT FOLLOWED BY COOLER DRIER WEATHER ON
SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM UPDATE...SHOWERS HAVE PRETTY MUCH COME TO AN END, WITH
JUST SOME ISOLATED ACTIVITY SEEN OVER CENTRAL MAINE. STARTING TO
SEE FOG DEVELOPMENT, ESPECIALLY IN DOWNEAST LOCATIONS. WITH PLENTY
OF LOW LEVEL MOISTURE AROUND, DON`T EXPECT TEMPERATURES WILL DROP
MUCH FROM CURRENT READINGS, MEANING IT`LL BE ANOTHER MUGGY NIGHT.
THE FORECAST PRETTY MUCH HAS THIS COVERED, SO JUST MADE SOME
TWEAKS TO POPS, SKY, AND TEMPS TO MATCH CURRENT TRENDS.
PREV DISCUSSION...THE MAIN CONCERNS THIS TERM WILL BE CONVECTION
AND THE POTENTIAL FOR SVR STORMS.
LATEST MESO ANALYSIS CONTINUED TO SHOW MUCAPES OF 700-1000 JOULES
EXPANDING INTO CENTRAL AND NORTHERN MAINE. THIS COINCIDES W/A
DECENT THETA E RIDGE IN PLACE. ATMOSPHERE IS DESTABILIZING AS LIS
DOWN TO -2 IN WNW AREAS AND EXPANDING E AS HEATING CONTINUES FOR
A FEW MORE HRS. LINE OF CONVECTION IN QUEBEC FIRED UP W/PLENTY OF
LIGHTNING. HRRR 3KM AND THE NAM12 PICKED UP ON THIS LINE BUT A BIT
OVERDONE W/THE PROJECTED SCATTERED CONVECTION FURTHER AS EVIDENT
FROM THE LATEST RADAR LOOP. THE HRRR AND NAM TO PROJECT A LINE OF
CONVECTION W/POSSIBLY BOWING SEGMENTS LATER THIS AFTERNOON INTO
THE EVENING CHALLENGE TO SEVERE POTENTIAL WILL BE 1)TIMING AND
2)850-500 MB LAPSE RATES PRETTY MEAGER(6.0 C/KM). SOME STORM COULD
HAVE ROTATION AS MODEL SOUNDINGS SHOWED LLVL VEERING THROUGH 7K
FT. STORMS DEFINITELY HAVE LLVL INSTABILITY IN PLACE W/0-3KM
LAPSE RATES CLOSE TO 6.8 C/KM AND SB CAPES OF 1400+ JOULES. THEY
ALSO HAVE THE POTENTIAL TO BE DEVIATE FROM THE ENE MOVEMENT WHICH
WOULD POINT TO POSSIBLE ROTATING STORMS IF THEY HOLD TOGETHER
MOVING E. ATTM, DECIDED TO STAY W/THE ENHANCED WORDING FOR STRONG
WIND GUSTS AND HEAVY RAINFALL MAINLY ACROSS THE CENTRAL HIGHLANDS
AND PORTIONS OF NORTHERN MAINE. NEEDED TO PULL BACK ON TIMING FROM
PREVIOUS PACKAGE. THIS WILL BE MONITORED THROUGH THE EVENING.
ACTIVITY WILL WIND DOWN AFTER 01Z AS THE PRE- FRONTAL BOUNDARY
MOVES E INTO NEW BRUNSWICK AND WE LOSE THE HEATING AND BEST
FORCING. ADDED FOG INTO THE FORECAST OVERNIGHT THE DENSE FOG
POSSIBLE OVER THE DOWNEAST AND COAST. KEPT OVERNIGHT MINS UP INTO
THE 60S THROUGHOUT MUCH OF THE CWA W/THE EXCEPTION FOR THE COAST
AS OVERNIGHT TEMPS WILL BE DOWN IN THE 50S.
ANOTHER ROUND OF CONVECTION POSSIBLE THURSDAY AFTERNOON INTO THE
EVENING. SPC HAS THE REGION IN A MARGINAL OUTLOOK MEANING SOME
ISOLD SEVERE STORMS ARE POSSIBLE. SURFACE COLD FRONT IN
CONJUNCTIONW/THE UPPER TROF ARE FORECAST TO MOVE ACROSS THE
REGION LATER IN THE DAY. EXPECTING ANOTHER POSSIBLE ACTIVE DAY AS
SB/MUCAPES ARE FORECAST TO HIT 1500+ JOULES IN THE AFTERNOON
W/EVEN HIGHER VALUES ACROSS THE INTERIOR DOWNEAST REGION.
ATMOSPHERE APPEARS TO BE MORE FAVORABLE FOR HAIL AS FREEZING
LEVELS DROP DOWN TO AROUND 11K FT. 0-6KM SHEAR RIGHT AROUND 30
KTS. 850-500MB LAPSE RATES LOOK TO BE MORE FAVORABLE FOR
CONVECTION W/VALUES 6.2-6.5 C/KM. LINE SEGMENTS APPEAR TO BE THE
MAIN MODE. AFTERNOON HIGH TEMPS ARE FORECAST TO BE IN THE 70S AND
LOWER 80S. THE EXCEPTION WILL BE ALONG THE COAST AS AN ONSHORE
FLOW OFF THE GULF OF MAINE WILL ALLOW FOR COOLER TEMPS.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
A COLD FRONT WILL BE PUSHING ACROSS THE SOUTHEASTERN PORTION OF
THE AREA THURSDAY EVENING. THERE MAY BE A LINGERING SHOWER OR
THUNDERSTORM IN EASTERN AREAS EARLY THURSDAY EVENING. SKIES WILL
THEN CLEAR FROM NORTHWEST TO SOUTHEAST THURSDAY NIGHT AS HIGH
PRESSURE BUILDS IN. HIGH PRESSURE WILL BRING BRIGHT SUNSHINE WITH
A WARM AFTERNOON ON FRIDAY AS THE HIGH BUILDS OVER. THIS WILL BE
FOLLOWED BY A MOSTLY CLEAR NIGHT FRIDAY NIGHT. A STRONGER COLD
FRONT APPROACHING ON SATURDAY WILL BRING AN INCREASING SOUTH WIND
AND A WARM AFTERNOON. CLOUDS WILL INCREASE AND SHOWERS AND
THUNDERSTORMS WILL LIKELY MOVE INTO WESTERN AREAS SATURDAY
AFTERNOON. STRONG WINDS LINED UP AT THE SURFACE AND ALOFT WILL
BRING THE POTENTIAL FOR STRONG GUSTY WINDS IN ANY STORMS SATURDAY
AFTERNOON.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
SHOWERS AND THUNDERSTORM, SOME POSSIBLY WITH STRONG GUSTY WINDS,
WILL BE LIKELY SATURDAY EVENING AS A STRONG COLD FRONT CROSSES THE
AREA. SKIES WILL BEGIN TO CLEAR FROM NORTH TO SOUTH SATURDAY NIGHT
INTO SUNDAY AS THE FRONT PUSHES OFFSHORE. SOME SIGNIFICANTLY COOLER
AND DRIER AIR WILL FOLLOW THE FRONT ON SUNDAY WITH HIGHS ONLY IN THE
60S ACROSS THE AREA. HIGH PRESSURE BUILDING OVER THE REGION WILL
BRING A CLEAR AND COOL NIGHT SUNDAY NIGHT FOLLOWED BY A SUNNY AND
SEASONABLE DAY ON MONDAY. THE HIGH WILL LIKELY MAINTAIN DRY WEATHER
THROUGH MID WEEK. THE NEXT CHANCE FOR SOME SHOWERS MAY COME ON
THURSDAY AS MOISTURE INCREASES BEHIND THE HIGH AND A WEAK COLD FRONT
BEGINS TO PUSH DOWN FROM CANADA.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
NEAR TERM: LINE OF -SHRA/-TSRA EARLY IN TAF PERIOD FOR HUL WITH
NORTHERN TERMINALS AND SOUTHERN TERMINALS MISSING OUT ON THE
PRECIPITATION. MVFR EXPECTED TO SET IN AFTER 00Z AT FVE AND CAR
PROGRESSING SOUTH THROUGH 08Z. BHB WILL START OFF WITH MVFR
RESTRICTIONS DROPPING TO IFR AFTER 04Z. BGR WILL LIKELY BE VFR
BEFORE BEING REDUCED TO IFR AFTER 05Z. ANOTHER ROUND OF MVFR
SHOWERS AND POSSIBLY -TSRA LATE IN TAF VALID TIME.
SHORT TERM: CONDITIONS MAY BEGIN MVFR THURSDAY EVENING THEN
IMPROVE TO VFR FROM NORTH TO SOUTH FOLLOWING A COLD FRONT THURSDAY
NIGHT. VFR CONDITIONS ARE THEN EXPECTED FRIDAY INTO SATURDAY
MORNING. CONDITIONS WILL LIKELY LOWER TO IFR LATE SATURDAY
AFTERNOON OR SATURDAY EVENING IN SHOWERS AND THUNDERSTORMS WITH A
STRONG COLD FRONT. CONDITIONS WILL IMPROVE TO VFR ACROSS THE NORTH
SUNDAY MORNING THEN ACROSS THE REST OF THE AREA DURING THE DAY ON
SUNDAY.
&&
.MARINE...
NEAR TERM: SCA STAYS UP THROUGH THURSDAY. WINDS/SEAS ARE RUNNING
BELOW SCA ATTM W/10 KTS AND SEAS 3-4 FT. CONDITIONS ARE FORECAST
TO INCREASE LATER TONIGHT INTO THURSDAY AS SSW WINDS INCREASE TO
15-20 KTS W/GUSTS UP TO 25 KT. SEAS ARE PROJECTED TO CLIMB TO 5-6
FT. FOG WILL BE A NUISANCE FOR NAVIGATION AS IT IS OUT ON THE
WATERS ATTM.
SHORT TERM: AN SCA MAY BE NEEDED SATURDAY INTO SATURDAY NIGHT FOR
INCREASING SOUTH WINDS AHEAD OF A STRONG COLD FRONT. WINDS WILL
BECOME NORTHERLY EARLY SUNDAY MORNING THEN DIMINISH ON SUNDAY AS
HIGH PRESSURE BUILDS IN BEHIND THE FRONT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ050-
051.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...BLOOMER
LONG TERM...BLOOMER
AVIATION...HASTINGS/HEWITT/BLOOMER
MARINE...HASTINGS/HEWITT/BLOOMER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1047 PM EDT FRI MAY 29 2015
.UPDATE...
ISSUED AT 1047 PM EDT FRI MAY 29 2015 RAIN GENERALLY ACROSS THE ENTIRE UPPER
PENINSULA...HOWEVER IT SHOULD BE COMING TO AN END FAIRLY SOON ACROSS
THE FAR WEST AS DRIER AIR PER 00Z INL RAOB MOVES AND SUBSIDENCE INTO
THE AREA. REALLY NO MAJOR CHANGES TO THE FORECAST PLANNED. EXPECT
THE BACK EDGE OF THE RAIN TO STEADILY MOVE EAST ACROSS THE U.P.
TONIGHT. ANY REMAINING DENSE FOG NEAR THE LAKESHORE SHOULD ALSO
DIMINISH AS THE DRIER PBL AIRMASS UPSTREAM OF THE LAKE MOVES ACROSS.
STILL EXPECTING TEMPS TO DROP INTO THE LOWER 40S NORTH AND UPPER
40S/LOWER 50S SOUTH. ALREADY IN THE LOWER 40S NORTH OF THE LAKE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 423 PM EDT FRI MAY 29 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NRN MANITOBA INTO THE PLAINS RESULTING IN SW FLOW INTO THE WRN GREAT
LAKES. A SHORTWAVE TROUGH INTO SRN MN AND UPPER LEVEL DIV WITH THE
RIGHT ENTRANCE OF THE NRN STREAM 110 KNOT 250-300 JET OVER NRN
ONTARIO SUPPORTED A LARGE AREA OF SHOWERS AND SOME EMBEDDED TSRA
FROM SRN MN INTO WRN WI. AT THE SFC...A COLD FRONT EXTENDED FROM
NEAR CYQT-KMSP. WITH LITTLE MLCAPE AND MUCAPE VALUES IN THE 500-1000
J/KG RANGE ONLY OCNL ISOLD LIGHTNING WAS OBSERVED WITH THE SHOWERS
FROM NWN WI THROUGH UPPER MI AHEAD OF THE FRONT.
TONIGHT...MODELS SUGGEST THAT THE SFC FRONT WILL MOVE INTO CNTRL
UPPER MI BY 00Z/SAT AND THROUGH THE REST OF UPPER MI BY 06Z/SAT.
HOWEVER...A PERIOD OF POST-FRONTAL PCPN SUPPORTED BY MID LEVEL FGEN
AND UPPER LEVEL DIV WITH THE JET RIGHT ENTRANCE WILL SUPPORT
ADDITIONAL PCPN THROUGH 06Z WITH QPF OF 0.25 TO 0.50 INCH OVER
MAINLY THE CNTRL AND EAST PORTIONS OF THE CWA. UNLESS ISOLD LARGER
PCPN AMOUNTS OCCUR OVER THE AREAS WITH THE HIGHEST RAIN AMOUNTS FROM
EARLIER IN THE WEEK S CNTRL...RIVER RISES SHOULD REMAIN MODEST
KEEPING LEVELS BLO FLOOD THRESHOLD. WITH MOST OF THE INSTABILITY
REMAINING ALONG AND SOUTH OF THE FRONT...ONLY A FEW EMBEDDED TSRA
ARE EXPECTED.
SATURDAY...EXPECT LINGERING HIGH CLOUDS TO CLEAR FROM THE NW DURING
THE MORNING WITH BREEZY NRLY WINDS AND CAA THROUGH THE DAY KEEPING
TEMPS BELOW SEASONAL AVERAGES. 850 MB TEMPS FROM -1C TO 4C WILL
SUPPORT MAX READINGS RANGING FROM THE MID AND UPPER 40S OVER THE
NORTH WITH FLOW OFF LAKE SUPERIOR TO THE UPPER 50S SOUTH. TEMPS
RIGHT ALONG THE LAKE MAY EVEN STRUGGLE TO CLIMB THROUGH THE LOWER
40S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 439 PM EDT FRI MAY 29 2015
AFTER AN ACTIVE WEEK OF SUMMERLIKE WEATHER...A MUCH QUIETER WEATHER
PATTERN IS IN STORE THROUGH AT LEAST EARLY NEXT WEEK. COULD TURN
ACTIVE AGAIN BY LATE NEXT WEEK THOUGH.
CONFLUENT FLOW ALOFT ON SOUTHERN EDGE OF TROUGH OVER EASTERN CANADA
ALLOWS THE SFC HIGH OVER CNTRL CANADA TO SPREAD OVER THE GREAT LAKES
INTO SUNDAY. FROST/FREEZE IS LIKELY SATURDAY NIGHT. MOS GUIDANCE
SUGGESTS MID 20S AT FAVORED COLD SPOTS. GIVEN DRYNESS OF THE AIRMASS
COMING OVERHEAD WITH PWATS DOWN TO AROUND 0.20 INCH AND AFTN DWPNTS
ON SATURDAY DOWN TO AROUND 20 DEGREES AT THE LOWEST...ALL BUT
IMMEDIATE GREAT LAKES SHORELINES WILL SEE TEMPS BLO 30 DEGREES. COLD
HAS BEEN WELL ADVERTISED IN GRIDS/EHWO/HWO AND FORECAST FOR MANY
DAYS. COORD WITH GRB AND DECIDED TO HOLD OFF ON FROST/FREEZE
HEADLINES UNTIL SAT MORNING WITH CONTINUED THREAT OF SHRA/TSRA
STILL ONGOING TONIGHT.
COOL CONDITIONS REMAIN OVER REGION ON SUNDAY WITH TEMPS INLAND ONLY
AROUND 60 DEGREES. TEMPS WILL STAY IN THE 40S NEAR LK SUPERIOR WITH
ONSHORE LAKE BREEZE WINDS. HIGH IS STILL NEARBY ON SUNDAY NIGHT AND
PWATS ARE JUST AS LOW AS SATURDAY NIGHT. THUS...ANOTHER NIGHT OF
TEMPS AT OR BLO FREEZING AND FROST/FREEZE FOR THE INTERIOR. LIKELY
LOOKING AT MORE FROST/FREEZE HEADLINES.
TROUGHING ALOFT IN VCNTY ON MONDAY...PERHAPS EVEN MORE SO THAN
SUNDAY. AIRMASS STAYS DRY SO NOT MUCH IN WAY OF CLOUDS OR SHRA. AS
FLOW ALOFT BECOMES MORE ZONAL TO SOUTHWEST THROUGH REST OF THE LONG
TERM A WARMING TREND DEVELOPS. HIGHS ON MONDAY A TOUCH BLO NORMAL...
WITH TEMPS IN THE UPR 60S WEST AND AS COOL AS THE 50S NEAR GREAT
LAKES AS LAKE BREEZES DOMINATE. PWATS STILL BLO 0.30 INCHES ON
MONDAY NIGHT OVER THE EAST AND THE HIGH REMAINS CLOSE BY...SO COULD
SEE YET ANOTHER NIGHT OF SUB FREEZING TEMPS AND FROST. STARTED A
COOLER TREND BY GOING WITH MID TEMPS IN THE MID 30S IN THE TYPICAL
COLD SPOTS OF CNTRL AND EASTERN CWA. LIGHT SOUTH WINDS SHOULD KEEP
WEST AND GREAT LAKES SHORES WARMER THAN SAT NIGHT AND SUN NIGHT.
TEMPS ON TUESDAY SHOULD BE BACK AROUND NORMAL WITH HIGHS IN THE
LOWER 70S WEST AND ONLY AS COOL AS THE LOW 60S NEAR THE GREAT LAKES
SHORES.
SHOULD BE OUT OF THE CHILLY NIGHT PATTERN BY TUESDAY NIGHT WITH
RETURN FLOW ARRIVING OVER THE UPPER GREAT LAKES BTWN HIGH PRESSURE
CENTER OVER THE LOWER GREAT LAKES AND SFC TROUGHING OVER THE CENTRAL
AND NORTHERN PLAINS. WARM AIR ADVECTION WILL ALLOW SOME MOISTURE TO
SPILL ACROSS UPPER LAKES ON WEDNESDAY AHEAD OF MAIN TROUGH ALOFT
OVER THE WESTERN CONUS. ANY WEAK SHORTWAVE WITHIN THE WSW FLOW ALOFT
WOULD COMBINE WITH WARMER TEMPS /MID-UPR 70S/ AND BUILDING
INSTABILITY TO BRING SMALL SHRA/TSRA CHANCES BACK TO UPR MICHIGAN.
BEST CHANCES FOR SHRA/TSRA WILL BE THURSDAY INTO FRIDAY AS WEST-EAST
ORIENTED FRONTAL BOUNDARY SLOWLY DROPS ACROSS UPPER GREAT LAKES
WHILE INTERACTING WITH MORE ENERGIZED WSW FLOW ALOFT. DEPENDING ON
THE AMOUNT OF INSTABILITY AROUND DURING THAT TIME...PATTERN IS ONE
THAT COULD BE WARM AND HUMID AND ACTIVE WITH MULTIPLE ROUNDS OF TSRA
SLIDING OVER THE AREA IN THE VICINITY OF THE FRONTAL BOUNDARY. PWATS
OFF THE GFS RISE UP TO 1.5 TO 1.75 INCHES ALONG THE BOUNDARY...SO
HEAVY RAIN WOULD ALSO BE A CONCERN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 1047 PM EDT FRI MAY 29 2015
RAIN WILL SPREAD ACROSS ALL OF THE TAF SITES THIS EVENING...ALONG
WITH IFR CONDITIONS FOR A PERIOD. NORTH WINDS WILL ALLOW FOR THE
WORST CONDITIONS TO BE AT SAW AND IWD...WHILE CMX MAY BE SPARED THE
WORST CONDITIONS DUE TO NORTH-NORTHEAST WIND GENERALLY BEING
DOWSLOPE COMPONENT. THUNDER MOST LIKELY DONE AT ALL SITES FOR
TONIGHT. AS DRIER AIR MOVES INTO THE REGION WITH THE HIGH PRESSURE
BUILDING ACROSS THE UPPER GREAT LAKES...EXPECT CONDITIONS TO IMPROVE
TO VFR BY MORNING AND REMAIN VFR ON SATURDAY...ALTHOUGH SOME GUSTY
NORTH WINDS CANNOT BE RULED OUT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT FRI MAY 29 2015
WINDS ARE EXPECTED TO STAY AT OR BELOW 20 KNOTS FOR MOST OF THIS
FORECAST PERIOD WITH THE EXCEPTION OF LATE TONIGHT THROUGH SATURDAY
WHERE THEY MAY INCREASE TO NEAR 30 KNOTS MAINLY ACROSS EASTERN LAKE
SUPERIOR BEHIND A COLD FRONT MOVING THROUGH THE REGION. FOG WILL
LINGER THROUGH INTO TONIGHT AND WILL BE DENSE AT TIMES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 AM EDT SATURDAY FOR LSZ248>251-
265>267.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...MRD
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...MRD
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
358 PM EDT THU MAY 28 2015
.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 355 PM EDT THU MAY 28 2015
HIGH IMPACT WEATHER POTENTIAL: ISOLATED/SCATTERED THUNDER POTENTIAL
WITH BRIEF HEAVY RAIN POSSIBLE INTO EARLY THIS EVENING.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: OVERHEAD RIDGING DOMINATES
WITHIN A QUASI-AMPLIFIED MID LEVEL FLOW REGIME ACROSS NOAM. CENTER
OF SURFACE HIGH HAS PUSHED OFF TO THE EAST...FORCING DEVELOPMENT OF
WEAK BACKSIDE RETURN FLOW AND SOME EARLY SUMMER WARMTH. AIRMASS IS A
MARGINALLY UNSTABLE ONE...WITH LATEST RAP GUIDANCE SHOWING UPWARDS
OF A FEW HUNDRED JOULES OF ML CAPE ACROSS INTERIOR NORTHERN LOWER
MICHIGAN. MIXING OF LOW LEVEL MOISTURE HAS LARGELY KEPT CONVECTIVE
INITIATION IN CHECK...ALTHOUGH DEVELOPMENT OF ORGANIZED SURFACE
CONVERGENCE MAXIMA VIA LAKE INFLUENCES HAS BEGUN TO KICK OFF A FEW
SHOWERS AND STORMS...PARTICULARLY ACROSS THE NORTHWEST CORNER OF GRR
CWA. WOULD EXPECT THESE TO CONTINUE TO PROPAGATE NORTHEAST INTO
EARLY THIS EVENING AS ASSOCIATED COLD POOLS/OUTFLOW INTERACT WITH
REMAINING NORTHERN MICHIGAN WARMTH.
PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPORAL AND SPATIAL
RESOLUTION OF SHOWERS AND STORMS INTO THIS EVENING.
DETAILS: TABLE HAS LARGELY BEEN SET...WITH FOCUSED CONVERGENCE
MAXIMA AND STORM INITIATION FAVORING ADDITIONAL ISOLATED TO
SCATTERED SHOWER AND STORM DEVELOPMENT INTO THIS AFTERNOON.
PROPAGATION OF ACTIVITY WILL LARGELY BE TIED TO THESE CORRIDORS OF
SURFACE CONVERGENCE AND INDIVIDUAL OUTFLOW BOUNDARIES. PER SATELLITE
TRENDS AND SIMPLE PATTERN RECOGNITION...WOULD EXPECT BEST "COVERAGE"
OF TO SLIDE NORTHEAST UP THROUGH INTERIOR NORTHERN LOWER MICHIGAN.
LACK OF DEEP LAYER FORCING AND MINIMAL INSTABILITY WILL LIKELY KEEP
OVERALL COVERAGE LIMITED...SO NOT ALL INTERIOR AREAS WILL GET WET.
DEEP LAYER SHEAR/MINIMAL INSTABILITY ARGUE AGAINST ANY SEVERE
POTENTIAL...ALTHOUGH ANTICIPATED SLOW MOVEMENT OF ACTIVITY ARGUES
FOR SOME HEAVY RAIN CONCERNS. OF COURSE...ANY VERY WELL ORGANIZED
UPDRAFT MAY BE CAPABLE OF A MARGINALLY SEVERE EVENT (ISOLATED LARGE
HAIL/GUSTY WINDS).
WITH INSTABILITY LOST...EXPECT A QUIET OVERNIGHT INTO THE EARLY
MORNING HOURS. MAY SEE SOME HIGH CLOUDS...WITH PATCHY FOG
DEVELOPING...ESPECIALLY WHERE RAIN MANAGES TO FALL.
&&
.SHORT TERM...(FRIDAY THROUGH SUNDAY)
ISSUED AT 355 PM EDT THU MAY 28 2015
...WARM FRIDAY/COOL WEEKEND WITH RAIN IN THE TRANSITION...
HIGH IMPACT WEATHER POTENTIAL: MARGINAL SEVERE THREAT FRIDAY
AFTERNOON/EVENING NORTHERN LOWER MICHIGAN. FROST POSSIBILITIES
SATURDAY NIGHT.
PATTERN SYNOPSIS/FORECAST: SPLIT FLOW/BLOCKY PATTERN ACROSS THE
EASTERN PACIFIC HAVING DOWNSTREAM IMPACTS ON NORTH AMERICAN PATTERN.
NORTHERN BRANCH FLOW CONFINED TO CANADA WHILE WEAKER/WAVY SOUTHERN
BRANCH FLOW IMPACTS THE CONTINENTAL U.S.. THERE ARE A PAIR OF SHORT
WAVE TROUGHS IN THE NORTHERN BRANCH OVER CENTRAL CANADA THAT WILL
EVENTUALLY PROVE IMPACTFUL FOR THE UPPER GREAT LAKES THIS WEEKEND.
SOUTHERN BRANCH HAS A PROMINENT SHORT WAVE TROUGH OVER THE
ROCKIES...ANOTHER WEAKER WAVE (POSSIBLY CONVECTIVELY ENHANCED) OVER
EASTERN PORTIONS OF KANSAS/OKLAHOMA (SHOWS UP BETTER AT 700MB).
AFTERNOON SURFACE ANALYSIS SHOWS A COLD/STATIONARY FRONT LYING
ACROSS NORTHERN LOWER MICHIGAN/NORTHERN WISCONSIN...ANOTHER BOUNDARY
LIES ALONG THE OHIO RIVER EXTENDING WEST INTO MISSOURI/KANSAS.
NORTHERN BRANCH HEIGHTS FALLS WILL BEGIN SPILLING INTO THE UPPER
MIDWEST FRIDAY...AND INTO THE UPPER LAKES SATURDAY. NORTHERN
MICHIGAN WILL REMAIN JUST ON THE SOUTHERN FRINGES OF THE MAIN
NORTHERN BRANCH ENERGY SATURDAY...WITH A COMBINED NORTHERN-SOUTHERN
BRANCH ZONAL FLOW EXPECTED FOR SUNDAY. FRONT OVER LOWER MICHIGAN
THIS AFTERNOON WILL PUSH/REDEVELOP NORTHWARD TONIGHT...WHILE
SOUTHERN PLAINS SHORT WAVE TROUGH LIFTS NORTH INTO WISCONSIN. A
COLD FRONT ASSOCIATED WITH NORTHERN BRANCH HEIGHT FALLS WILL CROSS
THE UPPER MIDWEST/UPPER MICHIGAN FRIDAY...THEN MOVE ACROSS LOWER
MICHIGAN FRIDAY NIGHT/SATURDAY. HIGH PRESSURE WILL THEN BUILD IN
BEHIND THIS FRONT TO END THE WEEKEND.
PRIMARY FORECAST CONCERNS: INCREASING RAIN CHANCES FRIDAY INTO
SATURDAY. LOW TEMPERATURES AND POSSIBLE FROST SATURDAY NIGHT.
FRIDAY...DEEP LAYER SOUTH/SOUTHWEST FLOW ACROSS MICHIGAN TO START
THE DAY FRIDAY...WITH SOUTHERN BRANCH SHORT WAVE TROUGH LIFTING
NORTHEAST ACROSS WISCONSIN AND INTO UPPER MICHIGAN. DEEP LAYER
MOISTURE WILL ADVECT ACROSS MICHIGAN WITH PRECIPITABLE WATER VALUES
CLIMBING TO OR ABOVE 1.50 INCHES. WILL PROBABLY BE SOME SHOWERS
ONGOING ALONG THE SHORT WAVE TROUGH FRIDAY MORNING...SOME OF WHICH
MAY CLIP NORTHWEST LOWER WITH A BETTER CHANCE OF RAIN GETTING INTO
EASTERN UPPER BY LATE MORNING INTO THE AFTERNOON HOURS...ENHANCED BY
APPROACHING COLD FRONT WHICH WILL HAVE A POST-FRONTAL (ANAFRONT)
RAIN BAND ASSOCIATED WITH IT. WHILE THIS IS OCCURRING...
DESTABILIZATION EXPECTED ACROSS NORTHERN LOWER WITH SOME HEATING AND
DEW POINTS INCREASING INTO THE 60S. COULD SEE SOME CONVECTION
BUBBLING UP ESPECIALLY ACROSS NORTH CENTRAL/NORTHEAST LOWER. A MORE
WIDESPREAD RAIN THREAT WILL DEVELOP FRIDAY NIGHT AS FRONTAL
CIRCULATION CROSSES THE FORECAST AREA...WITH THE POSSIBILITY OF PRE-
FRONTAL CONVECTION DURING THE EVENING ACROSS LOWER MICHIGAN...AND
POST-FRONTAL RAIN BAND WITH THE WIND SHIFT. ANOTHER WARM AFTERNOON
ANTICIPATED ACROSS THE AREA ESPECIALLY NORTHERN LOWER WHERE
TEMPERATURES WILL AGAIN BE IN THE 80 DEGREE VICINITY.
SATURDAY...RAIN SHOULD BE ONGOING TO START SATURDAY AS THE FRONT
PUSHES THROUGH LOWER MICHIGAN...GRADUALLY ENDING FROM NORTHWEST TO
SOUTHEAST AS THE DAY WEARS ON. WILL BE MUCH COOLER SATURDAY WITH A
BIT OF A NORTHERLY BREEZE NOT HELPING MUCH...WITH TEMPERATURES
MOSTLY IN THE 50S AND LOWER 60S. COOL HIGH PRESSURE BUILDS
SOUTHEAST INTO MICHIGAN FOR SATURDAY NIGHT...IF WINDS CAN DECOUPLE
SUFFICIENTLY MAY HAVE SOME PROBLEMS WITH FROST.
SUNDAY...QUIET TO END THE WEEKEND WITH HIGH PRESSURE TO THE NORTH
RESULTING IN COOL/DRY NORTHEAST BOUNDARY LAYER FLOW. TEMPERATURES
STILL ON THE COOL SIDE RELATIVE TO LATE MAY AVERAGES WITH HIGHS IN
THE 50S TO LOWER 60S.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 PM EDT THU MAY 28 2015
LONG RANGE MODELS ARE STILL IN GOOD AGREEMENT OF HIGH PRESSURE
DOMINATING NORTHERN MICHIGAN/S WEATHER THROUGH AT LEAST
WEDNESDAY...PROVIDING PRECIPITATION-FREE WEATHER...FAIRLY LIGHT
WINDS AND SEASONAL TEMPERATURES. LOOKS LIKE THERE IS STILL THE
POSSIBILITY OF SOME FROST SUNDAY NIGHT/MONDAY MORNING WITH THE
MOSTLY CLEAR SKIES AND LIGHT WINDS. NEXT CHANCES OF PRECIPITATION
WILL BE AT THE END OF THE WORK WEEK WITH A WEAK LOW PRESSURE SYSTEM
SETTING UP OVER THE NORTHERN PLAINS WITH SOME RETURN FLOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 132 PM EDT THU MAY 28 2015
...STILL MONITORING FOR SHOWER/THUNDERSTORM DEVELOPMENT THIS
AFTERNOON AND EARLY EVENING...
VFR CU FIELD STARTING TO BUILD ACROSS NORTHEAST LOWER
MICHIGAN...WITH THIS EXPECTED TO EXPAND FURTHER NORTHWEST WITH
TIME THIS AFTERNOON. JUST ENOUGH INSTABILITY TO DEVELOP A FEW
SHOWERS AND STORMS HEADING THROUGH THE AFTERNOON...ALTHOUGH
CONFIDENCE FAR FROM HIGH ENOUGH TO INCLUDE ANY IMPACTS AT THE TAF
SITES. "BEST" POTENTIAL EXPECTED AT KAPN AFTER MID
AFTERNOON...BUT EVEN HERE CONFIDENCE REMAINS VERY LOW. STORMS WILL
BE CAPABLE OF LOCALLY GUSTY WINDS AND HEAVY RAIN IF THEY OCCUR.
ANY SHOWERS END THIS EVENING...LEAVING MAINLY CLEAR SKIES AND
LIGHT WINDS. LOW LEVEL JET PRODUCES MARGINAL WIND SHEAR ACROSS ALL
TAF SITES DURING THE EARLY MORNING. GUSTY SOUTH WINDS DEVELOP
FRIDAY MORNING UNDER VFR HIGH/MID LEVEL CLOUD DECK. ONCE AGAIN MAY
SEE A FEW VIGOROUS CU PRODUCE ISOLATED/SCATTERED SHOWERS AND
STORMS AFTER MID MORNING.
&&
.MARINE...
ISSUED AT 355 PM EDT THU MAY 28 2015
STABLE ENVIRONMENT SHOULD PREVENT ANY APPRECIABLE MIXING
OVERNIGHT...PREVENTING MUCH TAPPING INTO DEVELOPMENT OF LOW LEVEL
JET OVERNIGHT. LIGHT/MODERATE SOUTHEAST WINDS TONIGHT BECOME A BIT
MORE GUSTY OUT OF THE SOUTH FRIDAY WITH SLOW APPROACH OF DEVELOPING
UPSTREAM COLD FRONT. PASSAGE OF THIS FRONT WILL BRING THE BEST
CHANCE FOR SCA PRODUCING CONDITIONS...WITH AN INCREASINGLY UNSTABLE
OVER-WATER ENVIRONMENT SUPPORTING GUSTY NORTHWEST TO NORTH WINDS
SATURDAY AND SATURDAY NIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
NEAR TERM...MSB
SHORT TERM...JPB
LONG TERM...TJL
AVIATION...MSB
MARINE...MSB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
439 AM EDT THU MAY 28 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 416 PM EDT WED MAY 27 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A SHORTWAVE EXITING TO THE
EAST OF LAKE SUPERIOR LEAVING WNW MID/UPPER LEVEL FLOW FROM S CNTRL
CANADA INTO THE NRN LAKES. A WEAK SHRTWV FROM WRN LAKE SUPERIOR INTO
NW WI COMBINED WITH MLCAPE VALUES FROM 500-1000 J/KG OVER AREAS
WHERE SUNSHINE HAS PREVAILED THIS AFTERNOON HAS TRIGGERED SOME
ISOLD/SCT SHRA/TSRA FROM YQT TO DLH AND NEAR THE WI BORDER FROM LNL
TO IMT.
LATE THIS AFTERNOON AND TONIGHT...RADAR TRENDS AND SHORT RANGE HIGH
RES MODELS SUGGEST THAT THE SHRA/TSRA WILL REMAIN NEAR THE WI
BORDER. SOME SHRA/TSRA MOVING ACROSS LAKE SUPERIOR ABOVE THE MARINE
LAYER MAY ALSO SURVIVE INTO NW UPPER MI THIS EVENING BUT WITH LESS
AVAILABLE MLCAPE AND THE LOSS OF DAYTIME HEATING...EXPECT THE
SHRA/TSRA TO DIMINISH. OTHERWISE...WITH COOLING BY LATE EVENING THE
REST OF THE PCPN WILL END.
WED...AS THE MID LEVEL TROUGH OVER THE ROCKIES EDGES TO THE EAST SW
FLOW WILL AGAIN DEVELOP FROM THE CNTRL PLAINS TO THE WRN LAKES.
EXPECT ENOUGH SUNSHINE TO PUSH TEMPS TO NEAR 80F OVER THE WEST HALF
RESULTING IN MLCAPE VALUES INTO THE 1000-1500 J/KG RANGE. THE MODELS
SUGGEST THAT A WEAK SHRTWV MOVING INTO THE AREA WILL TRIGGER ANOTHER
ROUND OF ISOL/SCT TSRA OVER THE WEST DURING THE AFTERNOON. WITH 0-
6KM SHEAR VALUES INTO THE 30-35 KNOT RANGE...A FEW STRONGER STORMS
COULD DEVELOP WITH SMALL HAIL AND GUSTY WINDS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 439 AM EDT THU MAY 28 2015
PRIMARY WEATHER ISSUES IN THE LONG TERM ARE TSRA STRENGTH ON FRIDAY
AND MIN TEMPS/FREEZE POTENTIAL FOR SATURDAY NIGHT AND SUNDAY NIGHT.
SHORTWAVE RIDGE IS OVER UPPER GREAT LAKES ON THURSDAY EVENING WITH
BROAD TROUGH FM CNTRL CANADA BACK OVER THE WESTERN CONUS. ANY ISOLD
SHRA/TSRA ON THURSDAY AFTN SHOULD FADE AWAY WITH LOSS OF DAYTIME
HEATING AND MINUS ADDITIONAL LARGER SCALE LIFTING MECHANISM. ANOTHER
SMALL CHANCE OF SHRA/TSRA LATER AT NIGHT OVER THE WEST AHEAD OF
BETTER MOISTURE TRANSPORT OUT AHEAD OF LOW PRESSURE AND COLD FRONT
MOVING ACROSS THE NORTHERN PLAINS. SOME HINT OF WEAKER SHORTWAVE
TIED TO THAT MOISTURE TRANSPORT. IF THAT OCCURS...BETTER CHANCE FOR
ORGANIZED SHRA AND POSSIBLE TSRA LATE THU NIGHT INTO FRIDAY MORNING.
AS CENTRAL CANADA TROUGH ALOFT DROPS ACROSS MANITOBA AND NORTHERN
ONTARIO ON FRIDAY ASSOCIATED LOW PRESSURE AND SFC COLD FRONT MOVES
FROM NORTHERN PLAINS TO THE UPPER GREAT LAKES. DECENT AGREEMENT FM
THE MODELS THAT FROPA OCCURS FRIDAY AFTN. MAIN QUESTION REMAINS IN
HOW MUCH INSTABILITY BUILDS UP AHEAD OF THE FRONT...AND WOULD
CERTAINLY BE AFFECTED BY ANY SHRA/TSRA AROUND DURING THE MORNING
HOURS. OVERALL THERE IS DECENT AGREEMENT THAT MLCAPES WILL BE AT
LEAST 500J/KG AND MAY BE OVER 1000 J/KG BY TIME FRONT WORKS ACROSS
IN THE AFTN. GREATEST INSTABILITY IS LOCATED OVER WI...BUT IS
FORECAST TO EXPAND OVER PORTIONS OF CNTRL UPR MICHIGAN AHEAD OF THE
FRONT. DEEP LAYER SHEAR UP TO 35 KTS WOULD BE FAVORABLE FOR
ORGANIZED STORMS...BUT POTENTIAL WILL BE HELD DOWN IF MORE
WIDESPREAD SHRA AND TSRA ARE AROUND EARLIER IN THE DAY. MOISTURE
AVAILABILITY NOT AN ISSUE AS PERSISTENT H85-H7 MOISTURE TRANSPORT
BOOSTS PWATS OVER 1.5 INCHES ALONG AND AHEAD OF THE FRONT. FAIR TO
SAY IF THERE IS AT LEAST SOME INSOLATION ON FRIDAY...THERE WOULD BE
RISK OF AT LEAST STRONG STORMS DURING THE AFTN. SPC DAY3 RISK HAS
MARGINAL CATEGORY MAINLY SOUTH OF HERE INTO WHERE BETTER CHANCE OF
HIGHER INSTABILITY RESIDES. FRONT MOVES ACROSS ALL OF UPR MICHIGAN
AFTER MIDNIGHT FRIDAY NIGHT. IT WILL PROBABLY TAKE UNTIL THE FRONT
HAS EXITED BEFORE CHANCES OF RAIN ARE ELIMINATED DUE TO DEEP
MOISTURE PERSISTING EVEN BEHIND THE SFC FRONT AND POSSIBILITY OF
SHORTWAVES WORKING THROUGH ON EDGE OF LARGE SCALE TROUGH. POPS
HIGHEST FRIDAY WITH THIS FROPA.
CONFLUENCE ALOFT ON WESTERN EDGE OF TROUGH MOVING ACROSS NORTHERN
ONTARIO AND QUEBEC LEADS TO LARGE HIGH PRESSURE BUILDING IN ON
SATURDAY. CHILLY DAY FOR LATE MAY STANDARDS ON SATURDAY AS TEMPS
EVEN INLAND TOWARD WI BORDER MAY ONLY STRUGGLE INTO THE 50S DESPITE
GOOD DEAL OF SUNSHINE. GRADIENT ONSHORE WINDS NEAR LK SUPERIOR WILL
KEEP TEMPS THERE IN THE 40S. AIRMASS QUITE DRY WITH PWATS DROPPING
TO 0.25-0.35 INCHES BY SATURDAY NIGHT. LIGHT WINDS/CLEAR SKIES AND
DRY AIRMASS POINT TO STRONG RADIATIONAL COOLING AND WITH DWPNTS ON
SATURDAY BLO 30F...A FREEZE IS LIKELY ON SATURDAY NIGHT. LACK OF ANY
ONSHORE FLOW LATER SATURDAY NIGHT FAVORS EVEN SHORELINE AREAS NEAR
LK SUPERIOR AND MOST OF LK MICHIGAN FOR MIN TEMPS AT LEAST IN THE
LOWER 30S WITH STRONG FROST POSSIBILITY. WEAK EASTERLY WINDS ON
SOUTHERLY EDGE OF SFC HIGH COULD KEEP BAY OF GREEN BAY SHORE IN FAR
SCNTRL WITH THE WARMEST TEMPS OVER THE CWA. ANOTHER CHILLY DAY FOR
SUNDAY UNDER MOSTLY SUNNY SKIES. INLAND TEMPS NEAR 60 DEGREES WHICH
IS OVER 10 DEGREES BLO NORMAL. TEMPS ALONG LK SUPERIOR WILL BE
MAINLY IN THE 40S OR 50S. WENT ON LOW SIDE FOR TEMPS SUNDAY NIGHT
AND INCLUDED FROST MENTION AGAIN. SOME BIAS CORRECTED GUIDANCE
INDICATED MINS BACK TO AROUND 32 DEGREES WHICH SEEMS REASONABLE
AS RIDGE AND DRY AIRMASS LINGERS...ESPECIALLY CNTRAL AND EAST.
REST OF EXTENDED FEATURES A WARMING TREND. UPPER LEVEL FLOW FLATTENS
OUT IN WAKE OF THE TROUGH THIS WEEKEND. HIGH AT THE SFC SLOWLY MOVES
OFF TO THE EAST OVER NEW ENGLAND AND MID ATLANTIC PUTTING PLAINS AND
GREAT LAKES WITHIN RETURN FLOW. H85 TEMPS AS EARLY AS TUESDAY RISE
TO 14C...WHICH WOULD YIELD HIGHS WELL INTO THE 70S INLAND FROM THE
GREAT LAKES. MAY SEE SOME MID CLOUDS SPILL ACROSS UPR LAKES ON
TUESDAY DUE TO WARM AIR ADVECTION H85-H7. PROBABLY NOT MUCH RISK OF
SHRA THOUGH AS FORCING AND MOISTURE IS MARGINAL AT BEST. MAYBE BETTER
CHANCE OF SHRA/TSRA ON WEDNESDAY AS TROUGH ALOFT HEADS ACROSS
WESTERN CONUS. BETTER CHANCES PROBABLY STAY WEST YET CLOSER TO THE
SFC LOW OVER THE NORTHERN PLAINS. AS LONG AS SYSTEM DOES NOT SPEED
UP TO THE EAST...GOOD CHANCE THAT TEMPS MAY TOP OUT AROUND 80
DEGREES ON WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 132 AM EDT THU MAY 28 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST. THERE REMAINS A
CONCERN FOR PATCHY FOG TO IMPACT ALL THREE SITES AS AS WINDS GO
LIGHT AND SKIES REMAIN CLEAR OVERNIGHT. THE BETTER POTENTIAL FOR LOW
CIGS AND FOG WILL BE AT KSAW AS LIGHT NE FLOW WILL BRING IN MOISTURE
OFF THE LAKE AND THUS HAVE BROUGHT IN MVFR VSBY THERE. LIGHT
EASTERLY FLOW OFF THE LAKE MAY ALSO REDUCE VSBY AT KCMX OVERNIGHT.
WITH RESIDUAL MOISTURE AT KIWD TO TO EARLIER RAINS FROM YESTERDAY
EVENING THEY ALSO HAVE A POSSIBILITY OF REDUCED VSBYS DUE TO FOG.
HAVE KEPT THESE RESTRICTIONS TO MVFR...BUT WOULD NOT DISCOUNT IFR
VSBYS DEVELOPING AT KSAW WITH THE UPSLOPE FLOW OFF THE LAKE. ONCE
THE SUN COMES UP...ANY FOG WILL QUICKLY BURN OFF. THERE IS A
POTENTIAL FOR LIGHT RAIN SHOWERS LATE IN THE AFTERNOON AT KIWD AND
KCMX BUT THE BETTER CHANCES FOR PCPN WILL HOLD OFF UNTIL 3Z WITH THE
APPROACH OF THE NEXT SYSTEM.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EDT WED MAY 27 2015WINDS ARE EXPECTED TO STAY AT OR BELOW 20 KNOTS FOR MOST
OF THIS FORECAST PERIOD WITH THE EXCEPTION OF FRI NIGHT INTO EARLY
SATURDAY WHERE THEY WILL INCREASE TO NEAR 30 KNOTS ACROSS EASTERN
LAKE SUPERIOR BEHIND A COLD FRONT MOVING THROUGH THE REGION. FOG
WILL LINGER THROUGH TONIGHT AND MAY BE DENSE AT TIMES. ADDITIONAL
FOG IS EXPECTED TO DEVELOP THURSDAY NIGHT AND FRIDAY AHEAD OF THE
NEXT LOW AND ASSOCIATED COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR MIZ005-006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...07
AVIATION...RJT
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 AM EDT THU MAY 28 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 416 PM EDT WED MAY 27 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A SHORTWAVE EXITING TO THE
EAST OF LAKE SUPERIOR LEAVING WNW MID/UPPER LEVEL FLOW FROM S CNTRL
CANADA INTO THE NRN LAKES. A WEAK SHRTWV FROM WRN LAKE SUPERIOR INTO
NW WI COMBINED WITH MLCAPE VALUES FROM 500-1000 J/KG OVER AREAS
WHERE SUNSHINE HAS PREVAILED THIS AFTERNOON HAS TRIGGERED SOME
ISOLD/SCT SHRA/TSRA FROM YQT TO DLH AND NEAR THE WI BORDER FROM LNL
TO IMT.
LATE THIS AFTERNOON AND TONIGHT...RADAR TRENDS AND SHORT RANGE HIGH
RES MODELS SUGGEST THAT THE SHRA/TSRA WILL REMAIN NEAR THE WI
BORDER. SOME SHRA/TSRA MOVING ACROSS LAKE SUPERIOR ABOVE THE MARINE
LAYER MAY ALSO SURVIVE INTO NW UPPER MI THIS EVENING BUT WITH LESS
AVAILABLE MLCAPE AND THE LOSS OF DAYTIME HEATING...EXPECT THE
SHRA/TSRA TO DIMINISH. OTHERWISE...WITH COOLING BY LATE EVENING THE
REST OF THE PCPN WILL END.
WED...AS THE MID LEVEL TROUGH OVER THE ROCKIES EDGES TO THE EAST SW
FLOW WILL AGAIN DEVELOP FROM THE CNTRL PLAINS TO THE WRN LAKES.
EXPECT ENOUGH SUNSHINE TO PUSH TEMPS TO NEAR 80F OVER THE WEST HALF
RESULTING IN MLCAPE VALUES INTO THE 1000-1500 J/KG RANGE. THE MODELS
SUGGEST THAT A WEAK SHRTWV MOVING INTO THE AREA WILL TRIGGER ANOTHER
ROUND OF ISOL/SCT TSRA OVER THE WEST DURING THE AFTERNOON. WITH 0-
6KM SHEAR VALUES INTO THE 30-35 KNOT RANGE...A FEW STRONGER STORMS
COULD DEVELOP WITH SMALL HAIL AND GUSTY WINDS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 412 PM EDT WED MAY 27 2015
PRIMARY WEATHER ISSUES IN THE LONG TERM ARE TSRA STRENGTH ON FRIDAY
AND MIN TEMPS/FREEZE POTENTIAL FOR SATURDAY NIGHT AND SUNDAY NIGHT.
SHORTWAVE RIDGE IS OVER UPPER GREAT LAKES ON THURSDAY EVENING WITH
BROAD TROUGH FM CNTRL CANADA BACK OVER THE WESTERN CONUS. ANY ISOLD
SHRA/TSRA ON THURSDAY AFTN SHOULD FADE AWAY WITH LOSS OF DAYTIME
HEATING AND MINUS ADDITIONAL LARGER SCALE LIFTING MECHANISM. ANOTHER
SMALL CHANCE OF SHRA/TSRA LATER AT NIGHT OVER THE WEST AHEAD OF
BETTER MOISTURE TRANSPORT OUT AHEAD OF LOW PRESSURE AND COLD FRONT
MOVING ACROSS THE NORTHERN PLAINS. SOME HINT OF WEAKER SHORTWAVE
TIED TO THAT MOISTURE TRANSPORT. IF THAT OCCURS...BETTER CHANCE FOR
ORGANIZED SHRA AND POSSIBLE TSRA LATE THU NIGHT INTO FRIDAY MORNING.
AS CENTRAL CANADA TROUGH ALOFT DROPS ACROSS MANITOBA AND NORTHERN
ONTARIO ON FRIDAY ASSOCIATED LOW PRESSURE AND SFC COLD FRONT MOVES
FROM NORTHERN PLAINS TO THE UPPER GREAT LAKES. DECENT AGREEMENT FM
THE MODELS THAT FROPA OCCURS FRIDAY AFTN. MAIN QUESTION REMAINS IN
HOW MUCH INSTABILITY BUILDS UP AHEAD OF THE FRONT...AND WOULD
CERTAINLY BE AFFECTED BY ANY SHRA/TSRA AROUND DURING THE MORNING
HOURS. OVERALL THERE IS DECENT AGREEMENT THAT MLCAPES WILL BE AT
LEAST 500J/KG AND MAY BE OVER 1000 J/KG BY TIME FRONT WORKS ACROSS
IN THE AFTN. GREATEST INSTABILITY IS LOCATED OVER WI...BUT IS
FORECAST TO EXPAND OVER PORTIONS OF CNTRL UPR MICHIGAN AHEAD OF THE
FRONT. DEEP LAYER SHEAR UP TO 35 KTS WOULD BE FAVORABLE FOR
ORGANIZED STORMS...BUT POTENTIAL WILL BE HELD DOWN IF MORE
WIDESPREAD SHRA AND TSRA ARE AROUND EARLIER IN THE DAY. MOISTURE
AVAILABILITY NOT AN ISSUE AS PERSISTENT H85-H7 MOISTURE TRANSPORT
BOOSTS PWATS OVER 1.5 INCHES ALONG AND AHEAD OF THE FRONT. FAIR TO
SAY IF THERE IS AT LEAST SOME INSOLATION ON FRIDAY...THERE WOULD BE
RISK OF AT LEAST STRONG STORMS DURING THE AFTN. SPC DAY3 RISK HAS
MARGINAL CATEGORY MAINLY SOUTH OF HERE INTO WHERE BETTER CHANCE OF
HIGHER INSTABILITY RESIDES. FRONT MOVES ACROSS ALL OF UPR MICHIGAN
AFTER MIDNIGHT FRIDAY NIGHT. IT WILL PROBABLY TAKE UNTIL THE FRONT
HAS EXITED BEFORE CHANCES OF RAIN ARE ELIMINATED DUE TO DEEP
MOISTURE PERSISTING EVEN BEHIND THE SFC FRONT AND POSSIBILITY OF
SHORTWAVES WORKING THROUGH ON EDGE OF LARGE SCALE TROUGH. POPS
HIGHEST FRIDAY WITH THIS FROPA.
CONFLUENCE ALOFT ON WESTERN EDGE OF TROUGH MOVING ACROSS NORTHERN
ONTARIO AND QUEBEC LEADS TO LARGE HIGH PRESSURE BUILDING IN ON
SATURDAY. CHILLY DAY FOR LATE MAY STANDARDS ON SATURDAY AS TEMPS
EVEN INLAND TOWARD WI BORDER MAY ONLY STRUGGLE INTO THE 50S DESPITE
GOOD DEAL OF SUNSHINE. GRADIENT ONSHORE WINDS NEAR LK SUPERIOR WILL
KEEP TEMPS THERE IN THE 40S. AIRMASS QUITE DRY WITH PWATS DROPPING
TO 0.25-0.35 INCHES BY SATURDAY NIGHT. LIGHT WINDS/CLEAR SKIES AND
DRY AIRMASS POINT TO STRONG RADIATIONAL COOLING AND WITH DWPNTS ON
SATURDAY BLO 30F...A FREEZE IS LIKELY ON SATURDAY NIGHT. LACK OF ANY
ONSHORE FLOW LATER SATURDAY NIGHT FAVORS EVEN SHORELINE AREAS NEAR
LK SUPERIOR AND MOST OF LK MICHIGAN FOR MIN TEMPS AT LEAST IN THE
LOWER 30S WITH STRONG FROST POSSIBILITY. WEAK EASTERLY WINDS ON
SOUTHERLY EDGE OF SFC HIGH COULD KEEP BAY OF GREEN BAY SHORE IN FAR
SCNTRL WITH THE WARMEST TEMPS OVER THE CWA. ANOTHER CHILLY DAY FOR
SUNDAY UNDER MOSTLY SUNNY SKIES. INLAND TEMPS NEAR 60 DEGREES WHICH
IS OVER 10 DEGREES BLO NORMAL. TEMPS ALONG LK SUPERIOR WILL BE
MAINLY IN THE 40S OR 50S. WENT ON LOW SIDE FOR TEMPS SUNDAY NIGHT
AND INCLUDED FROST MENTION AGAIN. SOME BIAS CORRECTED GUIDANCE
INDICATED MINS BACK TO AROUND 32 DEGREES WHICH SEEMS REASONABLE
AS RIDGE AND DRY AIRMASS LINGERS...ESPECIALLY CNTRAL AND EAST.
REST OF EXTENDED FEATURES A WARMING TREND. UPPER LEVEL FLOW FLATTENS
OUT IN WAKE OF THE TROUGH THIS WEEKEND. HIGH AT THE SFC SLOWLY MOVES
OFF TO THE EAST OVER NEW ENGLAND AND MID ATLANTIC PUTTING PLAINS AND
GREAT LAKES WITHIN RETURN FLOW. H85 TEMPS AS EARLY AS TUESDAY RISE
TO 14C...WHICH WOULD YIELD HIGHS WELL INTO THE 70S INLAND FROM THE
GREAT LAKES. MAY SEE SOME MID CLOUDS SPILL ACROSS UPR LAKES ON
TUESDAY DUE TO WARM AIR ADVECTION H85-H7. PROBABLY NOT MUCH RISK OF
SHRA THOUGH AS FORCING AND MOISTURE IS MARGINAL AT BEST. MAYBE BETTER
CHANCE OF SHRA/TSRA ON WEDNESDAY AS TROUGH ALOFT HEADS ACROSS
WESTERN CONUS. BETTER CHANCES PROBABLY STAY WEST YET CLOSER TO THE
SFC LOW OVER THE NORTHERN PLAINS. AS LONG AS SYSTEM DOES NOT SPEED
UP TO THE EAST...GOOD CHANCE THAT TEMPS MAY TOP OUT AROUND 80
DEGREES ON WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 132 AM EDT THU MAY 28 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST. THERE REMAINS A
CONCERN FOR PATCHY FOG TO IMPACT ALL THREE SITES AS AS WINDS GO
LIGHT AND SKIES REMAIN CLEAR OVERNIGHT. THE BETTER POTENTIAL FOR LOW
CIGS AND FOG WILL BE AT KSAW AS LIGHT NE FLOW WILL BRING IN MOISTURE
OFF THE LAKE AND THUS HAVE BROUGHT IN MVFR VSBY THERE. LIGHT
EASTERLY FLOW OFF THE LAKE MAY ALSO REDUCE VSBY AT KCMX OVERNIGHT.
WITH RESIDUAL MOISTURE AT KIWD TO TO EARLIER RAINS FROM YESTERDAY
EVENING THEY ALSO HAVE A POSSIBILITY OF REDUCED VSBYS DUE TO FOG.
HAVE KEPT THESE RESTRICTIONS TO MVFR...BUT WOULD NOT DISCOUNT IFR
VSBYS DEVELOPING AT KSAW WITH THE UPSLOPE FLOW OFF THE LAKE. ONCE
THE SUN COMES UP...ANY FOG WILL QUICKLY BURN OFF. THERE IS A
POTENTIAL FOR LIGHT RAIN SHOWERS LATE IN THE AFTERNOON AT KIWD AND
KCMX BUT THE BETTER CHANCES FOR PCPN WILL HOLD OFF UNTIL 3Z WITH THE
APPROACH OF THE NEXT SYSTEM.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EDT WED MAY 27 2015WINDS ARE EXPECTED TO STAY AT OR BELOW 20 KNOTS FOR MOST
OF THIS FORECAST PERIOD WITH THE EXCEPTION OF FRI NIGHT INTO EARLY
SATURDAY WHERE THEY WILL INCREASE TO NEAR 30 KNOTS ACROSS EASTERN
LAKE SUPERIOR BEHIND A COLD FRONT MOVING THROUGH THE REGION. FOG
WILL LINGER THROUGH TONIGHT AND MAY BE DENSE AT TIMES. ADDITIONAL
FOG IS EXPECTED TO DEVELOP THURSDAY NIGHT AND FRIDAY AHEAD OF THE
NEXT LOW AND ASSOCIATED COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...RJT
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
517 PM CDT Thu May 28 2015
.SHORT TERM: (Through Late Tonight)
Issued at 337 PM CDT Thu May 28 2015
Isolated-scattered showers and thunderstorms are expected to continue
early this evening ahead of 500-hPa shortwave trough with the best
coverage of storms across central Missouri. Combination of nocturnal
stabilization and subsidence behind aforementioned shortwave
should lead to weakening/dissipation of storms as well as a
corresponding drop in coverage late evening/early overnight. Late
tonight...sch/chc PoPs for showers/storms return to the area as
LLJ strengthens and veers from the SSW to the WSW late tonight. As
for temperatures...mild conditions are expected due to a partly to
mostly cloudy sky and a light southerly breeze. Expect lows
tonight in the mid to upper 60s areawide.
Gosselin
.LONG TERM: (Friday through Next Thursday)
Issued at 337 PM CDT Thu May 28 2015
(Friday-Saturday Night)
Another shortwave trough will eject out toward the mid-Mississippi Valley
during the day tomorrow...similar to today just a bit further to the
northwest. PoPs will be on the increase especially Friday afternoon
for portions of central/northeast Missouri as well as west-central Illinois
as synoptic cold front associated with northern stream energy slowly sags
southeastward into region. Continued likely PoPs for showers and storms
for Friday afternoon. As for chances of severe weather...appears any
widespread strong/severe storms will be difficult due to weak deep-layer
shear values...around 20 knots. However...isolated strong to severe storms
with large hail/damaging winds does look plausible due to moderately
strong instability (1000-2000 J/kg) values.
Cold front will continue its slow southeastward progression on
Friday night and Saturday. Highest probabilities for showers and
thunderstorms continues to hone in on this period. Timing of cold
front looks to clear CWA by mid/late Saturday morning. Like Friday
...deep-layer shear/instability parameters do not look supportive
of any widespread severe weather...but a strong to severe storm is
not out of the question. Behind the front...showers (along with
some possible embedded thunder) look likely as shortwave trough
slows down and upper-level jet streak backbuilds to the southwest
putting CWFA beneath the RER.
Temperatures on Saturday look to be challenging due to frontal
timing and associated precip chances. Leaned cool (highs in the
upepr 60s to low 70s) for areas well behind the front in central and
northeast Missouri and west-central Illinois where clouds are
expected to linger along with strong low-level CAA from the north.
For areas further to the south and east...did not deviate too much
from guidance with highs in the mid 70s to near 80 degrees expected.
Tightened PoP gradient a bit on Saturday night with highest PoPs
remaining across southeast Missouri and southwest Illinois in closer
proximity to cold front. Did remove some mention of thunder well
behind the front due to lack of instability. Surface high across
the Great Lakes will begin flexing its muscle with much cooler and
drier weather beginning to filter into from the north and east.
Forecast lows are expected to dip back below seasonal norms with
lows generally in the 50s expected.
(Sunday-Thursday)
A cutoff low is still expected to develop somewhere near the
bootheel of Missouri on Sunday. Confined PoPs to far southeastern
sections of the area which will be closer in distance to this
feature as well as remnant cold frontal boundary. Instability looks
meager at best so just mentioned isolated tunder for the far
southern and eastern counties. Lingering clouds with 850-hPa dipping
to near +10C should yield a chilly day for very late May. Highs only
in the mid to upper 60s are expected on Sunday.
Cutoff low is expected to meander slowly to the south/southwest
heading into the middle of next week. Precipitation chances look low
as region will likely be too far north of aforementioned cutoff low
and too far south of main corridor of cyclones transversing the
upper Midwest. Best chance of showers/storms at the moment appears
to be on Thursday with chance PoPs as GFS suggests a trough axis may
approach the area from the west. All in all...the extended portion
of the forecast Monday through Thursday appears to be mostly dry
with moderating temperatures back above normal by Thursday.
Gosselin
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 501 PM CDT Thu May 28 2015
Thunderstorms have fired primarily along a warm front lifting
across the area. This is in response to a shortwave which will
move across by 12z. Additional thunderstorm have formed across SW
MO in the warm air in advance of the wave. This activity will
likely impact COU this evening and potentially UIN closer to
Midnight. HRRR decreases this precipitation gradually overnight,
but does fire up some new stuff primarily across SE MO as the wave
moves across eastern MO. Possible given this area has not had any
rain so far. Activity drifts into SUS and CPS area about 08z. Am
not optimistic about this so will leave out for now but will
monitor development late this evening closely. Another wave which
looks weaker moves in Friday and this will help kick off
showers/thunderstorms Friday afternoon. Timing difficult so some
VCTS will be the best forecast for now. Overall, TAFS will stay
VFR except briefly when storms move through.
Specifics for KSTL: Question is whether STL will stay dry
overnight. HRRR kills current rain that is over SW MO but forms
new stuff about 08z, most likely in response to the short wave
lifting across the area. Have doubts if the atmosphere will be
unstable enought to support this, so will leave out for now but
will watch closely late this evening. Thunderstorms will lilely
fire Friday afternoon in response to another, although weaker,
wave moving through. Timing no certain so a VCTS for a couple of
hours will suffice for now. More thunderstorms will be likely as
the cold front moves in overnight Friday night into Saturday
morning.
JPK
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 69 84 69 78 / 30 60 50 70
Quincy 66 81 65 69 / 30 70 70 50
Columbia 66 79 65 71 / 50 70 70 50
Jefferson City 67 80 66 71 / 50 60 70 50
Salem 68 84 69 79 / 30 40 40 70
Farmington 66 80 68 77 / 30 50 50 60
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
336 AM CDT THU MAY 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT THU MAY 28 2015
MODELS IN FAIR AGREEMENT IN THE NEAR TERM. HAVE EXPANDED POPS ACROSS
WESTERN NEBRASKA THIS MORNING WITH ACTIVITY FROM THE HILLS TO
NORTHEAST COLORADO ALONG SURFACE TROUGH AXIS AND ISOLATED
THUNDERSTORMS OVER THE EASTERN NEBRASKA PANHANDLE. THESE STORMS HAVE
NOT MADE A PUSH OFF OF THE AXIS WITHOUT FALLING APART. SOME PATCHY
STRATUS AROUND GOODLAND THIS MORNING BUT DO NOT EXPECT THAT IT WILL
CONGEAL INTO A WIDE SPREAD EVENT THIS MORNING WITH 3 AND 4 DEGREE
DEW POINT SPREADS...SO HAVE LEFT OUT OF SOUTHWEST NEBRASKA THIS
MORNING. WILL AGAIN CARRY A PRE FIRST PERIOD TO ACCOUNT FOR ACTIVITY
OVER THE WEST. BOUNDARY FROM EAST TO WEST OVER CENTRAL KANSAS WHERE
MOST OF THE ACTIVITY IS THIS MORNING. SOME OF THIS PROGGED TO MOVE
INTO SOUTH CENTRAL TO NORTH CENTRAL ZONES THIS MORNING AND HAVE
RETAINED SOME CHANCE POPS BUT NOT REAL CONFIDENT THAT THIS IS GOING
TO OCCUR. THROUGH THE DAY THE TROUGH AXIS WILL MOVE OFF THE HIGHER
TERRAIN INTO THE WESTERN SANDHILLS WITH A SURFACE LOW DEEPENING
OVER NORTHWEST KANSAS. TROUGH WILL BE FOCUS FRO THUNDERSTORM
DEVELOPMENT THIS AFTERNOON AS STRONG UPPER WAVE MOVES OUT OF THE
NORTHERN ROCKIES INTO THE NORTHERN PLAINS. BEGIN TO RAMP UP POPS
AFTER 18Z AS ATMOSPHERE DESTABILIZES AND BEST SURFACE BASED CAPE MU
CAPE 850MB-700MB VALUES OVER SOUTHWEST NEBRASKA. DEW POINTS RISING
INTO THE 60S THIS AFTERNOON AND EVENING. PRECIPITATION AREA WILL
TRANSITION FROM TROUGH IN THE AFTERNOON TO THE COLD FRONTAL PASSAGE
THROUGH THE EVENING. HIGHS THIS AFTERNOON IN THE 70S WITH LOWS IN
THE 50S TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 333 AM CDT THU MAY 28 2015
PROGRESSIVE SYNOPTIC PATTERN CONTINUES THROUGH THE EXTENDED FORECAST
PERIOD. MAIN FORECAST CHALLENGE IS POPS/QPF FOR FRIDAY. SURFACE COLD
FRONT PUSHES SOUTH OF THE CWA INTO KS/EASTERN NEB BY 12Z FRIDAY.
PLENTIFUL MOISTURE REMAINS IN THE POST-FRONTAL ENVIRONMENT AND A
LARGE BUT RATHER DISORGANIZED UPPER LEVEL LOW WITH SEVERAL EMBEDDED
WEAK PV ANOMALIES MOVES OVERHEAD. FOLDED THETA-E FIELDS IN CROSS
SECTIONS SHOW POTENTIAL FOR SOME CONVECTIVE ACTIVITY...SO INCLUDED
MENTION OF ISOLATED THUNDER IN ADDITION TO THE HIGH CHANCE/LIKELY
RAIN SHOWERS. EC HAS BEEN THE MOST CONSISTENT MODEL OVER THE
PREVIOUS 72 HOURS IN REGARDS TO PRECIP COVERAGE AND QPF AND WAS USED
AS THE PRIMARY MODEL FOR THE FRIDAY FORECAST. LOCALIZED HEAVY RAIN
WILL BE POSSIBLE WITH PWATS AOA 1 INCH...BUT CONFIDENCE IN THIS
SCENARIO IS LOW AS MODELS SHOW THE BEST LOW LEVEL MOISTURE TRANSPORT
DEFLECTING EAST OF THE CWA EARLY IN THE DAY. POPS END FRIDAY NIGHT
AS AN AREA OF COOL/DRY CANADIAN HIGH MOVES SOUTH.
THE WEEKEND LOOKS DRY AS BROAD ANTICYCLONIC FLOW BUILDS OVER THE
CENTRAL CONUS WITH SYNOPTIC SCALE SUBSIDENCE ALOFT. BELOW NORMAL
HIGHS ARE EXPECTED SATURDAY AS THE AREA OF CANADIAN HIGH PRESSURE
MOVES THROUGH THE NORTHERN PLAINS...BUT GUIDANCE HAS TRENDED WARMER
FOR SUNDAY AS THE HIGH PUSHES EAST AND SOUTHERLY FLOW RETURNS. MID
LEVEL THERMAL RIDGE AXIS MOVES INTO THE EASTERN ROCKIES AND HIGH
PLAINS TO START THE MONTH OF JUNE...AND DIURNAL BOUNDARY LAYER
MIXING WILL PROMOTE HIGHS INTO THE LOW TO MID 80S. HUMIDITY WILL
ALSO BE ON THE INCREASE...AND IT MAY FEEL MUGGY AT TIMES WITH
DEWPOINTS IN THE LOW TO MID 60S. RIDGE BEGINS TO BREAK DOWN TUESDAY
AS THE NEXT UPPER LEVEL LOW DIGS INTO THE PACIFIC NORTHWEST. SHOWERS
AND THUNDERSTORMS ARE LIKELY OVER THE CENTRAL AND NORTHERN PLAINS BY
THE MIDDLE OF THE WEEK. SEVERE WEATHER WILL BE POSSIBLE BUT IT IS
TOO DISTANT IN THE FORECAST TO PINPOINT THE THREAT WITH ANY HIGH
LEVEL OF CONFIDENCE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1123 PM CDT WED MAY 27 2015
THE RAP AND NAM MODELS CONTINUE TO FORECAST STRATUS DEVELOPING
ACROSS SWRN NEB AROUND 06Z WHICH WOULD SPREAD NORTH TO KLBF AND
KVTN. IFR/MVFR CIGS ARE EXPECTED BY 09Z. GIVEN THE EXPECTED
INCREASE IN MOISTURE BELOW 700MB...THESE CLOUDS WOULD BE SLOW TO
MIX OUT THURSDAY MORNING. THUS VFR/MVFR IS EXPECTED 18Z-20Z.
TSTM CHANCES THURSDAY SHOULD COMMENCE ACROSS THE PANHANDLE AROUND
21Z WHICH SPREAD SLOWLY EAST INTO NCNTL NEB THURSDAY EVENING.
LASTLY...STORM ACTIVITY IS UNDERWAY ACROSS THE PANHANDLE AT 04Z.
THESE STORMS ARE EXPECTED TO MOVE EAST AND BECOME ISOLATED
OVERNIGHT.
&&
.HYDROLOGY...
ISSUED AT 335 AM CDT THU MAY 28 2015
NORTH PLATTE RIVER CONTINUES SLOW RISE WITH RELEASES UP STREAM.
THE SOUTH PLATTE RIVER CONTINUES TO RISE OVER WESTERN NEBRASKA WITH
SOME RAINFALL OVER THE BASIN IN NORTHEAST COLORADO AND THE CONTINUED
SNOW MELT IN THE ROCKIES. ADDITIONAL RAINFALL...SOME WHICH COULD BE
HEAVY...IS POSSIBLE THIS AFTERNOON AND TONIGHT OVER WESTERN
NEBRASKA. CHECK WITH LATEST WARNING INFORMATION FOR CRESTS AND TIMES.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...POWER
LONG TERM...MARTIN
AVIATION...CDC
HYDROLOGY...POWER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
325 AM CDT THU MAY 28 2015
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 303 AM CDT THU MAY 28 2015
A FEW AREAS OF CONVECTION ARE ONGOING AROUND THE PLAINS...BUT SO FAR
ARE OUTSIDE THE CWA...WITH THE NEAREST ONE MOVING ACROSS NORTHEAST
KS. SUBJECTIVE 00Z UPPER AIR ANALYSIS INDICATES WEAK WEST-
SOUTHWESTERLY UPPER-LEVEL FLOW ACROSS THE CENTRAL US...WITH A FEW
RIPPLES...AND WITH AN UPPER-LEVEL TROUGH NOTED IN ID/MT EXTENDING
INTO THE DESERT SOUTHWEST. NO NOTABLE 500MB HEIGHT FALLS WERE
ANALYZED IN THE CONUS..THOUGH BROAD HEIGHT RISES UP TO 100M WERE
NOTED FROM THE MO RIVER VALLEY TOWARD THE GREAT LAKES. AN AXIS OF
850MB 8C+ DEWPOINTS EXTENDED NORTWHARD THROUGH THE HIGH
PLAINS...WITH A DRY POCKET UNDER MID-LEVEL RIDGING FROM EASTERN
NEB/EASTERN DAKOTAS INTO IA/WESTERN GREAT LAKES. HINTS OF AN EML
ALSO MADE AN APPEARANCE...WITH 10C+ TEMPERATURES AT 700MB IN
NM/SOUTHERN TX. SURFACE TROUGH AXIS AT 07Z EXTENDED ALONG THE HIGH
PLAINS.
MAIN FORECAST CONCERNS ARE POTENTIAL FOR SHOWERS AND THUNDERSTORMS
TODAY THROUGH FRIDAY NIGHT. AREAS OF CONVECTION HAVE BEEN REMAINED
SCATTERED...WITH NONE IMMINENTLY THREATENING THE CWA. SHORT-RANGE
MODELS CONTINUE TO INDICATE SHOWERS AND THUNDERSTORMS MOVING INTO AT
LEAST THE SOUTHERN CWA YET THIS MORNING...AND HAVE KEPT A CHANCE IN
THE SOUTHWEST TO WESTERN CWA...THOUGH CONFIDENCE IS LOW.
INSTABILITY IS WEAK IN EASTERN NEB...AND THINK STORMS WOULD BE
WEAKENING. WITH THOUGHT THAT PRECIPITATION COVERAGE MIGHT BE LOWER
THAN PROGS...HAVE INDICATED TEMPERATURES ON THE WARMER SIDE OF
GUIDANCE TODAY. DO THINK SHOWERS/THUNDERSTORMS WILL DEVELOP IN THE
CWA THIS AFTERNOON/EVENING AS SHORTWAVE KICKS ACROSS THE
REGION...THOUGH STILL THINK BETTER INSTABILITY WILL BE WEST AND
SEVERE WEATHER POTENTIAL WILL BE LIMITED. CONVECTION SHOULD
CONTINUE TONIGHT AT LEAST IN SOME SENSE...PERHAPS IN BROKEN AREAS AS
IS ONGOING THIS MORNING...AND CURRENT POPS MIGHT BE A BIT ON THE
AGGRESSIVE SIDE.
CONVECTIVE EVOLUTION BECOMES EVEN MORE UNCERTAIN ON FRIDAY.
UPPER=LEVEL TROUGH WILL EJECT ACROSS THE PLAINS ON FRIDAY...WITH
SURFACE COLD FRONT PUSHING OUT OF SD FRIDAY AFTERNOON/EVENING. MAY
BE SOME ONGOING SHOWERS/THUNDERSTORMS IN THE MORNING OR THROUGH THE
DAY...WITH LITTLE TO HOLD IT BACK...AND THAT ACTIVITY WOULD WEAKEN
INSTABILITY. FRONTAL PASSAGE WILL BRING HIGHER CHANCES FOR SHOWERS
AND THUNDERSTORMS FRIDAY AFTERNOON/EVENING...WITH MUCH MORE COOL AND
STABLE AIRMASS BEHIND THE FRONT. HAVE SPED TIMING OF FRONTAL PASSAGE
JUST A BIT MORE...BUT DID HOLD ONTO SLIGHT CHANCES OF SHOWERS
THROUGH 12Z SATURDAY IN THE SOUTHERN CWA BEHIND THE FRONT.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 303 AM CDT THU MAY 28 2015
BEHIND THE FRONT...COOLER AND DRIER WEATHER WILL SPILL INTO THE
CENTRAL PLAINS FOR THE WEEKEND. UPPER-LEVEL RIDGE WILL BUILD
EASTWARD INTO THE CENTRAL US FROM THE WEEKEND INTO EARLY NEXT
WEEK...KEEPING WEATHER DRY AND BRINGING MODERATING TEMPERATURES AS
LOW- TO MID-LEVEL FLOW RETURNS TO SOUTHERLY. GFS AND ECMWF BOTH
HOLD AN UPPER-LEVEL TROUGH/WEAK UPPER LOW IN THE
SOUTHERN/SOUTHEASTERN US INTO EARLY NEXT WEEK. MOISTURE FROM THE
GULF MAY DIVERT TOWARD THAT FEATURE...WITH SOME RETURN FLOW MOISTURE
ADVECTED INTO THE HIGH PLAINS...AND DRIER AREA BETWEEN FOR MUCH OF
THE CENTRAL PLAINS.
RIDGE BREAKS DOWN TO SOUTHWESTERLY FLOW AROUND WEDNESDAY AS UPPER-
LEVEL TROUGH DIGS INTO THE WESTERN US...WITH CUTOFF UPPER LOW
HOLDING ITS PLACE. FIRST EJECTING SHORTWAVE MAY BRING ACTIVE
WEATHER TO THE NORTHERN PLAINS ON TUESDAY NIGHT/WEDNESDAY...BUT THAT
BATCH LOOKS TO STAY NORTH OF THE CWA. NEXT WAVE AROUND WEDNESDAY
NIGHT/THURSDAY LOOKS MORE LIKELY TO BRING ACTIVE WEATHER TO THE AREA.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1121 PM CDT WED MAY 27 2015
UPSTREAM CONVECTION CONTINUES TO WEAKEN AND DISSIPATE LATE THIS
EVENING WITH RAP MODEL PLACING MORE FOCUS ACROSS CENTRAL KANSAS
INTO SOUTHEAST NEBRASKA BY 12Z. HAVE PLACED A PERIOD OF CONVECTION
IN TAFS FOR MID TO LATE MORNING AS MID LEVEL WAVE MOVES ACROSS THE
AREA. OUTSIDE OF CONVECTION VFR CONDITIONS WILL PREVAIL.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...MAYES
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1259 AM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 1259 AM CDT THU MAY 28 2015
NO SIGNIFICANT ADJUSTMENTS NEEDED TO THE FCST. DID RAISE LOW TEMPS
2-3F FROM LXN-ODX DUE TO THE THICK CIRROSTRATUS CANOPY OVERHEAD.
THERE DOES APPEAR TO BE SOME SEMBLANCE OF A WEAK COOL FRONT W-E
ACROSS KS. CONFIDENCE IS VERY LOW IN TSTM FORMATION OVERNIGHT AND
POOR MODEL QPF`S EVEN IN THE 1ST 6 HRS OF THE 00Z RUNS DOES NOT
HELP.
THE 04Z HRRR HAS TSTMS ALREADY OVER THE FCST AREA THAT DO NOT
EXIST.
21Z SREF QPF PROBABILITIES SUGGEST INITIATION IN THE 06Z-09Z TIME
FRAME. A 30-40 KT LLJ WILL BE IMPINGING UPON THE FRONT...AND THERE
IS A LARGE PLUME OF 10-12C 850 MB DWPTS THAT WILL BE ADVECTING N.
MUCAPE UP TO 1000 J/KG COULD SUPPORT SOME HAILERS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 1259 AM CDT THU MAY 28 2015
ALOFT: 00Z ANALYSIS AND WV IMAGERY SHOWED A TROF OVER THE WRN
USA. THIS TROF WILL GRADUALLY ADVANCE E THRU TONIGHT AND WILL BE
LOCATED JUST W OF THE FCST AREA BY DAYBREAK FRI. SEVERAL SHORTWAVE
TROFS WERE EMBEDDED AND THIS MAKES TSTM POTENTIAL MUCH LESS CLEAR.
MORE LATER...
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT WED MAY 27 2015
TO BEGIN THE MID TERM PERIOD...THE ECMWF...GFS AND NAM SOLUTIONS ARE
IN GOOD AGREEMENT ON THE POSITION OF AN OPEN UPPER LEVEL WAVE ACROSS
THE NORTHERN ROCKIES. AT THE SURFACE...A LARGE AREA OF LOW PRESSURE
EXTENDS ALONG THE MAJORITY OF THE FRONT RANGE.
AS THE UPPER LEVEL WAVE SHIFTS EASTWARD THURSDAY NIGHT...VORTICITY
ADVECTION WILL SHIFT INTO THE REGION. THIS COMBINED WITH WARM AIR
ADVECTION OUT AHEAD OF THE SURFACE LOW...PLENTY OF GULF MOISTURE AND
A LOW LEVEL JET OVERNIGHT...THURSDAY NIGHT IS LOOKING LIKE THE BEST
CHANCE FOR WIDESPREAD PRECIPITATION ACROSS THE AREA. INSTABILITY
DECREASES AFTER SUNSET BUT STILL REMAINS DECENT ACROSS PORTIONS OF
NORTH CENTRAL KANSAS. DEEP LAYER SHEAR IS LACKING...WHILE LOW LEVEL
SHEAR IS BETTER. COULD WE SEE STRONG STORMS THURSDAY NIGHT...ITS
POSSIBLE ESPECIALLY ACROSS WESTERN ZONES.
THE MAIN UPPER LEVEL WAVE MOVES THROUGH ON FRIDAY...AS DOES THE
SURFACE LOW AND A COLD FRONT. TIMING ON THIS FRONT HAS SPED UP THE
LAST FEW MODEL RUNS WITH ITS CURRENT POSITION THROUGH THE TRI CITIES
EARLY FRIDAY MORNING. WENT SLIGHTLY COOLER ON HIGH TEMPERATURES
FRIDAY TO REFLECT THIS CHANGE. MODEL SOLUTIONS SUCH AS THE NAM/GFS
ALSO INDICATE PORTIONS OF THE SOUTHWEST ON FRIDAY WILL BE IN THE DRY
SLOT...THEREFORE LOWERED POPS JUST SLIGHTLY IN THAT REGION. WRAP
AROUND MOISTURE WILL BE PRESENT FOR AT LEAST A PORTION OF THE DAY ON
FRIDAY AFTER FRONTAL PASSAGE BUT SHOULD QUICKLY DECREASE. LEFT
LINGERING POPS IN THE SOUTHEAST FRIDAY NIGHT BUT TAPERED THEM OFF
QUICKLY AFTER 6Z. THE PREVIOUS RUN OF THE ECMWF LINGERED POPS ACROSS
MUCH OF THE FORECAST AREA THROUGH SATURDAY MORNING...MOST LIKELY
BASED ON THE ACTUAL WAVE ITSELF MOVING THROUGH...BUT THE 12Z RUN WAS
QUICK TO DRY OUT THE REGION AFTER 6Z...LEAVING SATURDAY MOSTLY DRY.
COLD AIR ADVECTION BEHIND THE FRONT WILL MAKE SATURDAY THE COOLEST
DAY OF THE WEEK WITH HIGHS IN THE 60S.
AN UPPER LEVEL RIDGE AND FINALLY ZONAL FLOW MOVES INTO THE REGION
SATURDAY THROUGH TUESDAY...LEAVING DRY CONDITIONS ACROSS THE PLAINS.
WARM AIR ADVECTION HELPS TEMPERATURES RECOVER BACK INTO THE UPPER
70S TO NEAR 80 BY MONDAY. NEXT LOW PRESSURE SYSTEM ON TAP FOR MID
WEEK...WHICH SHOULD BRING A COLD FRONT AND ADDITIONAL PRECIPITATION
TO THE REGION TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THU NIGHT)
ISSUED AT 1259 AM CDT THU MAY 28 2015
REST OF THE NIGHT: VFR WITH MULTI-LAYERED CIGS AT OR ABOVE 10K FT.
POCKETS OF IFR VSBYS POSSIBLE IN SCT TSTMS AFTER 09Z. WINDS SSE
UNDER 10 KTS. LLWS. CONFIDENCE: MEDIUM
THU: IT ALL HINGES ON TSTMS WHICH COULD BE ON-GOING OR VERY NEARBY.
SOME FCST GUIDANCE SUGGESTS MVFR OR IFR STRATUS DEVELOPS IN THE
WAKE OF THESE STORMS. FOR NOW HAVE KEPT THE FCST OPTIMISTIC...BUT
WATCH FOR AMENDMENTS. S-SSE WINDS 10-15 KTS. CONFIDENCE: LOW
THU EVE: PROBABLY VFR TO START...BUT ANOTHER PERIOD OF TSTMS IS
POSSIBLE AFTER 03Z. SE WINDS 10-15 KTS. CONFIDENCE: LOW
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...SALTZMAN
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1126 PM CDT WED MAY 27 2015
.SHORT TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 255 PM CDT WED MAY 27 2015
THE MAIN FORECAST CONCERN WILL BE TIMING AND COVERAGE OF
PRECIPITATION. LATEST SHORT RANGE MODEL GUIDANCE SUGGESTS THE
MOST RECENT RADAR RETURNS OVER NORTH CENTRAL KANAS WILL STRUGGLE
TO MAKE IT TO EASTERN NEBRASKA MUCH BEFORE 06Z AS THE CURRENT
AIRMASS IS QUITE STABLE. DECIDED TO GO FAIRLY PESSIMISTIC WITH THE
NEAR-TERM FORECAST AND HAVE A DRY FORECAST THROUGH MIDNIGHT.
THEREAFTER AS THE FIRST OF TWO WEAK MID-LEVEL SHORTWAVES TRACK
INTO THE FORECAST AREA AND WE SHOULD SEE SHOWERS AND THUNDERSTORMS
DEVELOP AND LINGER INTO THURSDAY MORNING. THERE REALLY ISN`T A DRY
PERIOD IN THE FORECAST UNTIL SATURDAY MORNING...BUT DID LOWER
PRECIPITATION CHANCES FOR THURSDAY AFTERNOON BEFORE RAMPING THEM
UP AGAIN WHEN THE SECOND SHORTWAVE FINALLY TRACKS THROUGH THE
FORECAST AREA DURING THE EVENING. AS MENTIONED WE EXPECT A DRY
PERIOD OF WEATHER TO BEGIN SATURDAY MORNING AS SURFACE HIGH
PRESURE TAKES HOLD AND 500MB HEIGHTS RISE. 850MB TEMPERATURES WILL
TAKE A BIT OF DIP...THOUGH REMAIN WELL ABOVE FREEZING...ALLOWING
SATURDAY MORNING LOWS TO DROP INTO THE MID 40S NORTH TO LOW 50S
SOUTH AND EAST.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 255 PM CDT WED MAY 27 2015
THIS FORECAST PERIOD BEGINS WITH THE SURFACE HIGH PRESSURE
AREA STILL IN PLACE. THIS LULL IN PRECIPITATION LOOKS TO PERSIST
THROUGH EARLY WEDNESDAY. BY MID- WEDNESDAY THE UPPER LEVEL RIDGE
MOVES FURTHER EAST AND WESTERN CONUS TROUGH BECOMES ESTABLISHED.
AS A RESULT THE FORECAST AREA WILL SEE SEVERAL SHORT WAVE TROUGH
PASS THROUGH BRINGING RAIN BACK IN THE FORECAST BY WEDNESDAY AND
LIKELY THEREAFTER.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1121 PM CDT WED MAY 27 2015
UPSTREAM CONVECTION CONTINUES TO WEAKEN AND DISSIPATE LATE THIS
EVENING WITH RAP MODEL PLACING MORE FOCUS ACROSS CENTRAL KANSAS
INTO SOUTHEAST NEBRASKA BY 12Z. HAVE PLACED A PERIOD OF CONVECTION
IN TAFS FOR MID TO LATE MORNING AS MID LEVEL WAVE MOVES ACROSS THE
AREA. OUTSIDE OF CONVECTION VFR CONDITIONS WILL PREVAIL.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...PEARSON
LONG TERM...PEARSON
AVIATION...FOBERT
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1123 PM CDT WED MAY 27 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 309 PM CDT WED MAY 27 2015
ISOLATED TO WIDELY SCATTERED TSRA ONGOING IN THE SW NEB PANHANDLE
NEAR WY BORDER AND ALSO IN NERN CO. THOSE IN THE NEB PANHANDLE ARE
MORE ORGANIZED ALONG AN OUTFLOW BOUNDARY FROM EARLIER CONVECTION IN
SERN WY. ISOLD WEAKER CONVECTION NOTED IN THE NRN PANHANDLE. FURTHER
SOUTH IN NERN CO IS WHERE MORE ROBUST CONVECTION IS AND BASED ON SPC
MESOANALYSIS HAS THE BEST POTENTIAL FOR FURTHER DEVELOPMENT THROUGH
THE AFTERNOON AND EVE. DISCRETE SUPERCELL IN NERN CO IS MOVING
SLOWLY AND APPEARS TO BE LOCATED ALONG WARM FRONT WHICH IS SLOWLY
MOVING NWD. NERN CO STORM IS ASSISTED BY WEAK PV ANOMALY BUT IN THE
AREA OF 3K SFC BASED CAPE VALUES AND ALONG LOW LEVEL LAPSE RATE
GRADIENT. FURTHER DEVELOPMENT IS ALSO INCREASING ALONG BOUNDARY
FURTHER SOUTHWEST INTO CO...AND MORE STORMS DEVELOPING ALONG WARM
FRONT IN KS. SHORT RANGE MODELS AND OTHER CAMS AND INCLUDING CAPS 20
MEMBER ENSEMBLE SUGGEST THESE TWO AREAS WILL CONTINUE TO PROGRESS
EWD AND WILL AFFECT THE WRN CAW THIS EVENING...THOUGH MOST SUGGEST A
WEAKENING TREND WITH THE STORMS THAT MOVE OUT OF THE PANHANDLE...AND
THE MORE ROBUST STORMS IN NERN CO SHOULD MOVE INTO NWRN KS AND BE
REINFORCED BY A DEVELOPING LLJ THIS EVENING...WHICH WOULD MEAN
PROPAGATION VECTORS SHOULD BECOME MORE SERLY ORIENTED. MOISTURE HAS
BEEN POOLING ALONG AND NORTH OF THE WARM FRONT IN KS...AND KLBF HAS
GOTTEN TO 56 CURRENTLY.
ALTHOUGH STRATUS DEVELOPMENT IS POSSIBLE OVERNIGHT...PROJECTED
CLEARING BY LATE MORNING...ESPECIALLY IN SWRN NEB...SHOULD ALLOW FOR
ENOUGH TIME FOR DESTABILIZATION OF THE ATMOSPHERE AHEAD OF A MORE
ROBUST PV ANOMALY WHICH IS PROGGED TO MOVE INTO THE HIGH PLAINS BY
LATER AFTERNOON. AS THIS UPPER FORCING ENHANCES THE LIFT ALONG THE
LOW LEVEL THETA GRADIENT THAT DEVELOPS THROUGH THE DAY OVER WRN KS
AND INTO WRN NEBR...ADDITIONAL THUNDERSTORM DEVELOPMENT IS LIKELY BY
AFTERNOON. GFS MUCH QUICKER WITH ITS PREFRONTAL TROF POSITION BY
AFTERNOON AND THEREFORE DEVELOPS CONVECTIVE COMPLEXES MUCH FURTHER E
INTO CENTRAL AND NERN NEB BY THU AFTERNOON. THE NAM ON THE OTHER
HAND SUGGESTS DEVELOPMENT IN NWRN KS AND MOVING INTO CENTRAL NEBR
DURING THE EVENING. AT ANY RATE THUNDERSTORM COVERAGE SHOULD BE
GREATER FOR THE AREA TMRW...AND INTENSITY OF CONVECTION SHOULD ALSO
BE GREATER WITH THE INCREASING LOW LEVEL MOISTURE AND EVENTUAL CAPE
BY AFTERNOON. HEAVY RAIN IS ALSO POSSIBLE WITH PW VALUES INCREASING
TO OVER AN INCH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 309 PM CDT WED MAY 27 2015
FOR THURSDAY NIGHT...PROJECTION OF THE LOW LEVEL WIND AND THETA-E
INDICATES THAT WEAK SPEED CONVERGENCE AND WARM ADVECTION IN THE
0-2KM THETA-E GRADIENT WILL CONTINUE LIFTING MOIST UNSTABLE AIR OVER
SOUTH CENTRAL AND SOUTHWEST NEBRASKA AND...TO A LESSER EXTENT...
NORTH CENTRAL NEBRASKA AND THE SANDHILLS. THE STRONG CONVECTIVE
POTENTIAL AND MORE FAVORABLE 0-6KM BULK SHEAR IS LIKELY TO BE
CONFINED TO THE SOUTHERN TWO TIERS OF NEBRASKA ZONES. HOWEVER...IT
SEEMS THAT...OVER THE LAST WEEK OR SO ANYWAY...THE LOCAL AREA HAS
HAD MARGINALLY LARGE HAIL WITH BULK SHEAR SEEMINGLY NOT FAVORABLE.
AT TIMES...STRONG CONVECTIVE POTENTIAL WITH 15-25KT BULK SHEAR HAS
BEEN SUFFICIENT FOR PRODUCING 1 INCH HAIL. THE PROJECTED SCENARIO
THURSDAY EVENING SHOWS A NARROW FINGER OF SURFACE-BASED CONVECTIVE
POTENTIAL OF 2500-3500J/KG EXTENDING OVER THE NEBRASKA SANDHILLS AND
2000-3000J/KG 800MB BASED POTENTIAL WITH 15-25KT BULK SHEAR IN THE
0-6KM LAYER...BUT THE HODOGRAPH AND STORM RELATIVE HELICITY DOES NOT
APPEAR TO BE FAVORABLE FOR ROTATING UPDRAFTS. THEREFORE...THOUGH
THERE ARE MARGINALLY FAVORABLE CONDITIONS FOR SEVERE WEATHER...WE
WILL NOT INCLUDE THE WORDING FOR SEVERE AT THIS TIME.
A SURFACE BOUNDARY AND UPPER TROUGH COME ACROSS NEBRASKA FRIDAY WITH
875MB BASED LIFTED INDICES OF 0C TO -2C AHEAD OF IT. THIS WILL BRING
THE LIKELIHOOD OF SIGNIFICANT RAINFALL THROUGH FRIDAY EVENING AND
THE POSSIBILITY OF THUNDERSTORMS.
AFTER FRIDAY NIGHT...AN UPPER RIDGE BUILDS IN THE WEST AND THE
SURFACE BOUNDARY IS PUSHED AGAINST THE ROCKIES. THIS WILL BRING A
REPRIEVE IN THE RAINFALL FOR MOST OF THE WEEKEND.
AS THE HIGH MOVES OFF TOWARD THE GREAT LAKES AND MISSISSIPPI VALLEY
SUNDAY...RETURN FLOW WILL BEGIN BRINGING MOISTURE ONTO THE HIGH
PLAINS FROM THE SOUTHWEST. INSTABILITY...PRECIPITABLE WATER AND LOW
LEVEL THETA-E THEN INCREASE AGAIN AS GULF MOISTURE TRACES A SOMEWHAT
CIRCUITOUS TRAJECTORY FROM TEXAS ONTO THE HIGH PLAINS WITH A MORE
DIRECT TRAJECTORY DEVELOPING BY MONDAY AFTERNOON. THEN...AS THE
SURFACE BOUNDARY BECOMES BETTER DEVELOPED WITH A SHARP THETA-E
GRADIENT...A MENTION OF PRECIPITATION IS AGAIN APPROPRIATE POSSIBLY
AS EARLY AS MONDAY OR TUESDAY WITH BETTER CHANCES TUESDAY NIGHT OR
WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1123 PM CDT WED MAY 27 2015
THE RAP AND NAM MODELS CONTINUE TO FORECAST STRATUS DEVELOPING
ACROSS SWRN NEB AROUND 06Z WHICH WOULD SPREAD NORTH TO KLBF AND
KVTN. IFR/MVFR CIGS ARE EXPECTED BY 09Z. GIVEN THE EXPECTED
INCREASE IN MOISTURE BELOW 700MB...THESE CLOUDS WOULD BE SLOW TO
MIX OUT THURSDAY MORNING. THUS VFR/MVFR IS EXPECTED 18Z-20Z.
TSTM CHANCES THURSDAY SHOULD COMMENCE ACROSS THE PANHANDLE AROUND
21Z WHICH SPREAD SLOWLY EAST INTO NCNTL NEB THURSDAY EVENING.
LASTLY...STORM ACTIVITY IS UNDERWAY ACROSS THE PANHANDLE AT 04Z.
THESE STORMS ARE EXPECTED TO MOVE EAST AND BECOME ISOLATED
OVERNIGHT.
&&
.HYDROLOGY...
ISSUED AT 309 PM CDT WED MAY 27 2015
NORTH PLATTE RIVER SLOWLY COMING UP AT LISCO AND LEWELLEN WITH
UPSTREAM RELEASES AND RAINFALL OF THE LAST FEW DAYS. FCST CREST
HEIGHT FOR LISCO IS HALF A FOOT LOWER WITH THIS MORNINGS FCST BASED
ON LESSER AMOUNTS OF WATER DUE TO RELEASES UPSTREAM...BUT
UNCERTAINTIES EXIST. PLEASE SEE FLOOD STATEMENTS PERTAINING TO THE
NORTH PLATTE RIVER AT LISCO AND LEWELLEN FOR FURTHER DETAILS.
THE SOUTH PLATTE RIVER CONTINUES ITS RISE FROM ROSCOE TO NORTH
PLATTE AND WILL CONTINUE TO DO SO THROUGH FRIDAY. THESE RISES DUE TO
RAINFALL OVER THE BASIN IN NORTHEAST COLORADO RECENTLY...PAIRED WITH
THE CONTINUED SNOW MELT IN THE ROCKIES. THE JULESBURG GAGE IS
SHOWING THE CREST HAS LIKELY PASSED THERE. ADDITIONAL
RAINFALL...SOME WHICH COULD BE HEAVY...IS POSSIBLE THURSDAY AND
THURSDAY NIGHT IN THE BASIN. CHECK WITH LATEST WARNING INFORMATION
FOR CRESTS AND TIMES.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JWS
LONG TERM...SPRINGER
AVIATION...CDC
HYDROLOGY...JWS
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1049 AM PDT THU MAY 28 2015
.SYNOPSIS...A FEW AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
WILL BE AROUND TODAY AND POSSIBLY ON FRIDAY OVER THE SOUTHERN GREAT
BASIN. OTHERWISE EXPECT DRY CONDITIONS WITH A WARMING TREND THROUGH
THE WEEKEND. THE WARMEST WEATHER OF THE YEAR SO FAR IS EXPECTED THIS
WEEKEND. TEMPERATURES SHOULD GRADUALLY LOWER TO NEAR NORMAL BY THE
MIDDLE OF NEXT WEEK.
&&
.UPDATE...FORECAST IS ON TRACK AND NO UPDATES ARE PLANNED AT THIS
TIME. THE BEST OPPORTUNITY FOR SEEING A SHOWER OR ISOLATED
THUNDERSTORM WILL BE OVER THE PANHANDLE OF LINCOLN COUNTY THIS
AFTERNOON...WHERE SOME MARGINAL INSTABILITY WILL BE IN PLACE. TODAY
WILL BE THE FIRST DAY WITH ABOVE NORMAL TEMPERATURES IN QUITE A
WHILE. THE MAIN FORECAST ISSUE WILL BE THE WEEKEND HEAT. THE RECORD
HIGH IN LAS VEGAS ON SUNDAY IS 104 AND WE WILL BE VERY CLOSE TO
REACHING THAT VALUE.
&&
.PREVIOUS DISCUSSION...
235 AM PDT THU MAY 28 2015
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT.
THE PATTERN ALOFT WILL TRANSITION TODAY TO ONE THAT IS WARMER AND
DRIER. A MID/UPPER LEVEL TROUGH THAT HAS BEEN AROUND OVER THE AREA
FOR MOST OF MAY WILL TRANSITION TO THE EAST TODAY OPENING THE DOOR
FOR A RARE RIDGE ALOFT TO BUILD INTO CALIFORNIA FROM THE PACIFIC.
THERE IS STILL ENOUGH MID-LEVEL MOISTURE AND A SMALL RIPPLE
(WEAKNESS) NOTED IN THE MODEL 500 MB HEIGHTS IN THE WAKE OF THIS
TROUGH ACROSS SOUTH-CENTRAL NEVADA THAT WITH THE HEATING OF THE DAY
A FEW SHOWERS AND THUNDERSTORMS COULD POP OVER THE SOUTHERN GREAT
BASIN FROM NORTHERN INYO TO LINCOLN COUNTIES. THE COVERAGE OF
ACTIVITY SHOULD BE A LITTLE LESS THAN YESTERDAY AND BASED ON THE
LATEST HRRR AND LOCAL ARW AND NMM 4 KM MODELS NO CHANGES WERE MADE
TO POPS. LIGHTNING, WIND GUSTS TO 45 MPH AND DOWNPOURS WILL AGAIN BE
THE MAIN HAZARDS WITH ANY STRONGER THUNDERSTORMS. OTHERWISE, EXPECT
A DRY DAY WITH CIRRUS SPILLING IN FROM THE NORTHWEST THROUGH THE DAY
COURTESY OF THE JET STREAM FEEDING IN HIGH LEVEL MOISTURE. TEMPS
WILL WARM A FEW MORE DEGREES AND THE WARMER MAV (GFS) NUMBERS WERE
MAINLY USED WITH ADDITIONAL TWEAKS BASED ON WHAT WE SAW YESTERDAY.
CIRRUS SHOULD CROSS THE AREA TONIGHT RESULTING IN A PARTLY CLOUDY
SKY ON AVERAGE. THE RIDGE ALOFT WILL BUILD FURTHER INLAND TOMORROW.
AGAIN, THE ARW AND NMM AS WELL AS THE WRF HINT THAT FEW SHOWERS MAY
TRY TO GO IN THE AFTERNOON AND EVENING OVER THE SOUTHERN SIERRA AND
IN NORTHERN LINCOLN COUNTY. LOW END SLIGHT CHANCE POPS WERE KEPT IN
FOR THIS AS THIS WILL COME DOWN TO MAINLY MOISTURE FROM SNOWMELT
SUBLIMATING AND TERRAIN HEATING DRIVING CONVECTION. OTHERWISE,
EXPECT TEMPS TO WARM A FEW MORE DEGREES AND AGAIN I WENT WITH THE
WARMER MAV.
SATURDAY LOOKS DRY AND RELATIVELY CLOUD-FREE AS THE RIDGE AXIS
BECOMES CENTERED OVER CALIFORNIA. HIGHS SHOULD WARM A FEW DEGREES
WHICH WOULD GIVE LAS VEGAS THE FIRST TRIPLE DIGIT HIGH OF THE YEAR
AT MCCARRAN THOUGH SOME EASTERN PARTS OF THE LAS VEGAS VALLEY WILL
LIKELY SEE THAT TODAY OR ON FRIDAY. TEMPS WILL NOT COOL OFF AS MUCH
AT NIGHT AS THE HEAT ISLAND KICKS IN AND LOWS FAIL TO DROP BELOW THE
MID 70S. OUR HIGH LAST FRIDAY WAS ONLY 74 IN CASE YOU FORGOT.
AS A REMINDER, CHECK YOUR AIR CONDITIONER AND STAY HYDRATED IF YOU
HAVE ANY WEEKEND PLANS. IN ADDITION, SNOW AND ICE MELT WILL CREATE
HIGH ELEVATION HAZARDS ESPECIALLY IN THE SIERRA. WE HAVE ISSUED A
GRAPHIC TO HIGHLIGHT THIS.
.LONG TERM...SUNDAY THOUGH THURSDAY MORNING.
HIGH PRESSURE OVER THE WESTERN US WILL DOMINATE THIS PERIOD WITH HOT
TEMPERATURES UNTIL MONDAY WHEN THE RIDGE BEGINS TO FLATTEN A BIT AS
AN UPPER LEVEL TROUGH APPROACHES THE PACIFIC NORTHWEST...HELPING TO
TAMPER TEMPS A FEW DEGREES AND INCREASE WINDS ACROSS THE AREA. THE
TROUGH WILL PASS BY WELL TO THE NORTH KEEPING CHANCES OF PRECIP WELL
NORTH...WITH ONLY SLIGHTLY COOLER TEMPS...NEAR NORMAL FOR THIS TIME
OF YEAR...AND SOME HIGH CLOUDS EXPECTED FOR THE AREA FOR TUESDAY AND
WEDNESDAY. BY THURSDAY ANOTHER TROUGH IS PROGGED TO DROP DOWN THE
BACK SIDE OF THE DEPARTING TROUGH FROM WEDNESDAY. THE GFS AND ECMWF
HANDLE THIS TROUGH DIFFERENTLY...WITH THE ECMWF BEING THE SLOWER OF
THE TWO AND DIGGING IT ALONG THE COAST IN CONTRAST TO THE GFS WHICH
IS MORE PROGRESSIVE AND FURTHER INLAND. BOTH MODELS KEEP DYNAMICS
AND MOISTURE CONFINED TO THE SIERRA AND SOUTHERN GREAT BASIN AT THIS
POINT.
&&
.AVIATION...FOR MCCARRAN...WINDS WILL FAVOR TYPICAL DIURNAL
DIRECTIONAL TRENDS AT 10 KTS OR LESS THROUGH THIS EVENING WITH THE
HIGHEST SPEEDS IN THE LATE AFTERNOON AND EVENING. FEW-SCT CLOUDS AOA
12K FEET IN THE AFTERNOON WITH SCT-BKN CLOUDS AOA 25K FEET TONIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED SHRA/TSRA AFTER 20Z THURSDAY AND ENDING BY 05Z
FRIDAY NORTH OF KIYK-KDRA-KCDC LINE. GUSTY AND ERRATIC WINDS ARE
POSSIBLE IN AND NEAR ANY SHRA/TSRA WITH CIGS LOWERING TO 5K-8K FEET
AND LOCAL MOUNTAIN OBSCURATIONS POSSIBLE. OTHERWISE WINDS WILL FAVOR
TYPICAL DIURNAL DIRECTIONAL TRENDS AT 10 KTS OR LESS THROUGH
THURSDAY EVENING WITH THE HIGHEST SPEEDS IN THE LATE AFTERNOON AND
EVENING. FEW-SCT CLOUDS AOA 12K FEET IN THE AFTERNOON WITH SCT-BKN
CLOUDS AOA 25K FEET THURSDAY NIGHT.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE...CZYZYK
SHORT TERM/AVIATION...STACHELSKI
LONG TERM...STEELE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
235 AM PDT THU MAY 28 2015
.SYNOPSIS...A FEW AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
WILL BE AROUND TODAY AND POSSIBLY ON FRIDAY OVER THE SOUTHERN GREAT
BASIN. OTHERWISE EXPECT DRY CONDITIONS WITH A WARMING TREND THROUGH
THE WEEKEND. THE WARMEST WEATHER OF THE YEAR SO FAR IS EXPECTED THIS
WEEKEND. TEMPERATURES SHOULD GRADUALLY LOWER TO NEAR NORMAL BY THE
MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT.
THE PATTERN ALOFT WILL TRANSITION TODAY TO ONE THAT IS WARMER AND
DRIER. A MID/UPPER LEVEL TROUGH THAT HAS BEEN AROUND OVER THE AREA
FOR MOST OF MAY WILL TRANSITION TO THE EAST TODAY OPENING THE DOOR
FOR A RARE RIDGE ALOFT TO BUILD INTO CALIFORNIA FROM THE PACIFIC.
THERE IS STILL ENOUGH MID-LEVEL MOISTURE AND A SMALL RIPPLE
(WEAKNESS) NOTED IN THE MODEL 500 MB HEIGHTS IN THE WAKE OF THIS
TROUGH ACROSS SOUTH-CENTRAL NEVADA THAT WITH THE HEATING OF THE DAY
A FEW SHOWERS AND THUNDERSTORMS COULD POP OVER THE SOUTHERN GREAT
BASIN FROM NORTHERN INYO TO LINCOLN COUNTIES. THE COVERAGE OF
ACTIVITY SHOULD BE A LITTLE LESS THAN YESTERDAY AND BASED ON THE
LATEST HRRR AND LOCAL ARW AND NMM 4 KM MODELS NO CHANGES WERE MADE
TO POPS. LIGHTNING, WIND GUSTS TO 45 MPH AND DOWNPOURS WILL AGAIN BE
THE MAIN HAZARDS WITH ANY STRONGER THUNDERSTORMS. OTHERWISE, EXPECT
A DRY DAY WITH CIRRUS SPILLING IN FROM THE NORTHWEST THROUGH THE DAY
COURTESY OF THE JET STREAM FEEDING IN HIGH LEVEL MOISTURE. TEMPS
WILL WARM A FEW MORE DEGREES AND THE WARMER MAV (GFS) NUMBERS WERE
MAINLY USED WITH ADDITIONAL TWEAKS BASED ON WHAT WE SAW YESTERDAY.
CIRRUS SHOULD CROSS THE AREA TONIGHT RESULTING IN A PARTLY CLOUDY
SKY ON AVERAGE. THE RIDGE ALOFT WILL BUILD FURTHER INLAND TOMORROW.
AGAIN, THE ARW AND NMM AS WELL AS THE WRF HINT THAT FEW SHOWERS MAY
TRY TO GO IN THE AFTERNOON AND EVENING OVER THE SOUTHERN SIERRA AND
IN NORTHERN LINCOLN COUNTY. LOW END SLIGHT CHANCE POPS WERE KEPT IN
FOR THIS AS THIS WILL COME DOWN TO MAINLY MOISTURE FROM SNOWMELT
SUBLIMATING AND TERRAIN HEATING DRIVING CONVECTION. OTHERWISE,
EXPECT TEMPS TO WARM A FEW MORE DEGREES AND AGAIN I WENT WITH THE
WARMER MAV.
SATURDAY LOOKS DRY AND RELATIVELY CLOUD-FREE AS THE RIDGE AXIS
BECOMES CENTERED OVER CALIFORNIA. HIGHS SHOULD WARM A FEW DEGREES
WHICH WOULD GIVE LAS VEGAS THE FIRST TRIPLE DIGIT HIGH OF THE YEAR
AT MCCARRAN THOUGH SOME EASTERN PARTS OF THE LAS VEGAS VALLEY WILL
LIKELY SEE THAT TODAY OR ON FRIDAY. TEMPS WILL NOT COOL OFF AS MUCH
AT NIGHT AS THE HEAT ISLAND KICKS IN AND LOWS FAIL TO DROP BELOW THE
MID 70S. OUR HIGH LAST FRIDAY WAS ONLY 74 IN CASE YOU FORGOT.
AS A REMINDER, CHECK YOUR AIR CONDITIONER AND STAY HYDRATED IF YOU
HAVE ANY WEEKEND PLANS. IN ADDITION, SNOW AND ICE MELT WILL CREATE
HIGH ELEVATION HAZARDS ESPECIALLY IN THE SIERRA. WE HAVE ISSUED A
GRAPHIC TO HIGHLIGHT THIS.
.LONG TERM...SUNDAY THOUGH THURSDAY MORNING.
HIGH PRESSURE OVER THE WESTERN US WILL DOMINATE THIS PERIOD WITH HOT
TEMPERATURES UNTIL MONDAY WHEN THE RIDGE BEGINS TO FLATTEN A BIT AS
AN UPPER LEVEL TROUGH APPROACHES THE PACIFIC NORTHWEST...HELPING TO
TAMPER TEMPS A FEW DEGREES AND INCREASE WINDS ACROSS THE AREA. THE
TROUGH WILL PASS BY WELL TO THE NORTH KEEPING CHANCES OF PRECIP WELL
NORTH...WITH ONLY SLIGHTLY COOLER TEMPS...NEAR NORMAL FOR THIS TIME
OF YEAR...AND SOME HIGH CLOUDS EXPECTED FOR THE AREA FOR TUESDAY AND
WEDNESDAY. BY THURSDAY ANOTHER TROUGH IS PROGGED TO DROP DOWN THE
BACK SIDE OF THE DEPARTING TROUGH FROM WEDNESDAY. THE GFS AND ECMWF
HANDLE THIS TROUGH DIFFERENTLY...WITH THE ECMWF BEING THE SLOWER OF
THE TWO AND DIGGING IT ALONG THE COAST IN CONTRAST TO THE GFS WHICH
IS MORE PROGRESSIVE AND FURTHER INLAND. BOTH MODELS KEEP DYNAMICS
AND MOISTURE CONFINED TO THE SIERRA AND SOUTHERN GREAT BASIN AT THIS
POINT.
&&
.AVIATION...FOR MCCARRAN...WINDS WILL FAVOR TYPICAL DIURNAL
DIRECTIONAL TRENDS AT 10 KTS OR LESS THROUGH THURSDAY EVENING WITH
THE HIGHEST SPEEDS IN THE LATE AFTERNOON AND EVENING. FEW-SCT CLOUDS
AOA 12K FEET IN THE AFTERNOON WITH SCT-BKN CLOUDS AOA 25K FEET
THURSDAY NIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED SHRA/TSRA AFTER 20Z THURSDAY AND ENDING BY 05Z
FRIDAY NORTH OF KIYK-KDRA-KCDC LINE. GUSTY AND ERRATIC WINDS ARE
POSSIBLE IN AND NEAR ANY SHRA/TSRA WITH CIGS LOWERING TO 5K-8K FEET
AND LOCAL MOUNTAIN OBSCURATIONS POSSIBLE. OTHERWISE WINDS WILL FAVOR
TYPICAL DIURNAL DIRECTIONAL TRENDS AT 10 KTS OR LESS THROUGH
THURSDAY EVENING WITH THE HIGHEST SPEEDS IN THE LATE AFTERNOON AND
EVENING. FEW-SCT CLOUDS AOA 12K FEET IN THE AFTERNOON WITH SCT-BKN
CLOUDS AOA 25K FEET THURSDAY NIGHT.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...STACHELSKI
LONG TERM...STEELE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
939 PM MDT FRI MAY 29 2015
.UPDATE...
UPDATED GRIDS TO REMOVE THE SEVERE T STORM WATCH HEADLINES AND THE
SEVERE WORDING...THOUGH A FEW STRONG STORMS COULD REDEVELOP A
COUPLE HOURS EITHER SIDE OF MIDNIGHT. LATEST NAM MORE BULLISH FOR
SE THIRD OF NM WHILE HRRR MODEL INDICATES MORE THE NE THIRD OR SO
OF THE STATE. ONLY A FEW MODEST SHOWERS UP IN NE AS OF THIS
ISSUANCE. THUS TRIMMED BACK POPS SIGNIFICANTLY FOR REST OF PRE
MIDNIGHT HOURS WITH LESS SIGNIFICANT CUTTING BACK AFTER MIDNIGHT
AS AT LEAST SOME ADDITIONAL DEVELOPMENT EXPECTED. ZONE FCST
PRODUCT ALREADY OUT.
43
&&
.PREV DISCUSSION...517 PM MDT FRI MAY 29 2015...
.AVIATION...
00Z TAF CYCLE
ONCE AGAIN THE MAIN FOCUS FOR AVIATION IMPACTS IS OVER EASTERN NM
WHERE A SVR TSTORM WATCH IS IN EFFECT TIL 04Z. DAMAGING WINDS AND
LARGE HAIL ARE THE MAIN THREATS FROM KCAO SOUTH TO KTCC AND KROW
THIS EVENING. THIS ACTIVITY WILL MOVE SE NEAR 20KTS AND EXIT THE
REGION INTO WEST TX. FARTHER WEST...VIRGA SHOWERS ARE CREATING
ERRATIC/GUSTY OUTFLOW WINDS AND THESE WILL DISSIPATE AFT SUNSET.
THE NEXT PERIOD FOR IMPACTS WILL BEGIN AFT STORMS EXIT THE EAST
AND A FRONTAL BOUNDARY MOVES SW ALL THE WAY THRU THE BRIO GRANDE
VALLEY TONIGHT. MORE STORMS...LOCALLY STRONG...WILL FIRE UP AND
BECOME A LARGE AREA OF RAIN WITH MVFR CIGS/VSBY REDUCTION...
PARTICULARLY ALONG THE EAST SLOPES OF THE CENTRAL MT CHAIN. GAP
WINDS WILL PLOW THRU KABQ BTWN 07Z-09Z W/ AWW GUSTS TO 35KTS
POSSIBLE. AFTER SLOW CLEARING OF IMPACT CONDITIONS IN THE EAST
SATURDAY...MORE STORMS WILL FIRE UP IN THE AFTERNOON AROUND THE
HIGH TERRAIN AND OVER EASTERN NM.
GUYER
&&
.PREV DISCUSSION...316 PM MDT FRI MAY 29 2015...
.SYNOPSIS...
THE WARMING AND DRYING TREND CONTINUES TODAY WITH ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS FOCUSING ACROSS NORTHEAST AND EAST
CENTRAL PORTIONS OF THE AREA WHERE A FEW STORMS MAY BECOME SEVERE.
A BACKDOOR COLD FRONT WILL PUSH SOUTHWEST ACROSS THE AREA TONIGHT
INTO SATURDAY RESULTING IN GUSTY EAST CANYON/GAP WINDS IN THE RIO
GRANDEAND UPPER TULAROSA VALLEYS. SOME COOLING SATURDAY BEHIND
THE FRONT ACROSS THE EASTERN PLAINS WILL RESULT IN A DOWNTREND IN
THUNDERSTORMS THERE...BUT MOISTURE MOVING IN BEHIND THE FRONT WILL
RESULT IN A ROUND OF LATE DAY THUNDERSTORMS OVER THE CENTRAL AND
WESTERN MOUNTAINS. THE WARMING TREND RESUMES SUNDAY WITH ANOTHER
ROUND OF AFTERNOON AND EVENING THUNDERSTORMS FORECAST.
TEMPERATURES WILL GENERALLY BE ABOVE NORMAL NEXT WEEK AS A RIDGE
OF HIGH PRESSURE SHIFTS OVERHEAD AND DRY AIR MOVES IN BEHIND IT
LEADING TO A SEVERAL DAYS WITH LITTLE TO NO CHANCE FOR
THUNDERSTORMS.
&&
.DISCUSSION...
ROUND OF CONVECTION ONGOING ACROSS THE NORTHEAST HIGHLANDS INTO
THE NORTHEAST AND EAST CENTRAL PLAINS. HOWEVER...SURFACE BASED
INSTABILITY IS NOT AS IMPRESSIVE AS YESTERDAY WITH DEWPOINT
TEMPERATURES 5-10 DEGREES LOWER...BUT WITH MUCH IMPROVED
DIRECTIONAL SHEAR SEVERE STORMS ARE IMMINENT. A SEVERE
THUNDERSTORM WATCH WAS JUST ISSUED FOR MUCH OF THE EAST. THE
BACKDOOR FRONT WILL CONTINUE TO PROVIDE A FOCUS FOR INITIATION
THROUGH THE AFTERNOON AND EARLY EVENING HOURS ACROSS THE NORTHEAST
AND EAST CENTRAL PLAINS. THE 18Z NAM IS SHOWING A WEAK SHORTWAVE
TROUGH MOVING SOUTHEAST ACROSS SOUTHERN COLORADO AND NE NEW MEXICO
OVERNIGHT WITH RENEWED CHANCES FOR STORMS ACROSS THE EASTERN
PLAINS/HIGHLANDS.
THE BACKDOOR FRONT IS STILL FORECAST TO PUSH THROUGH THE CENTRAL
MOUNTAIN CHAIN TONIGHT...RESULTING IN GUSTY EAST CANYON/GAP WINDS
IN THE BRIO GRANDE AND UPPER TULAROSA VALLEYS. WINDS ARE
CURRENTLY FORECAST JUST BELOW ADVISORY CRITERIA. WESTWARD LOW
LAYER MOISTURE TRANSPORT IN THE FRONTAL LAYER THROUGH SATURDAY
WILL RESULT IN A LATE-DEVELOPING ROUND OF STORMS ALONG THE CENTRAL
AND WESTERN HIGHER TERRAIN WITH MOVEMENT OFF TO THE SOUTH OR
SOUTHEAST INTO THE EVENING HOURS.
A RIDGE OF HIGH PRESSURE WILL SHIFT OVER THE AREA SUNDAY INTO
MONDAY WITH 500MB HEIGHTS REACHING UP TO 588-589DAM...WHICH WILL
BE MORE THAN SUFFICIENT TO BRING-ON A RENEWED WARMING TREND.
SLOW-MOVING DAYTIME HEATING TRIGGERED STORMS ARE FORECAST SUNDAY
AND MONDAY...FOLLOWING NORMAL DIURNAL TRENDS. HIGHS WILL ACTUALLY
BE ABOVE NORMAL MOST AREAS MONDAY THROUGH AT LEAST WEDNESDAY AS
THE RIDGE AXIS SHIFT EAST AND DRY WESTERLIES PUNCH IN...WITH A
BROAD LOW AMPLITUDE TROUGHING PATTERN OVER THE WESTERN CONUS. NEXT
WEEK WILL CERTAINLY FEEL MORE SEASONAL THAN WHAT WE SAW FOR MUCH
OF MAY.
11
&&
.FIRE WEATHER...
DRIER CONDITIONS WITH ISOLATED HIGHER BASED SHOWERS/STORMS WILL
IMPACT WESTERN/CENTRAL AREAS REST OF TODAY INTO THIS EVENING.
GUSTY OUTFLOW WINDS WOULD BE THE MAIN THREAT FROM THIS ACTIVITY.
DRYLINE STORMS OF THE WETTER VARIETY WOULD BE FOUND ACROSS THE
EASTERN PLAINS. THIS ACTIVITY SHOULD GO WELL INTO THE OVERNIGHT
HOURS AND ACTUALLY ENHANCE IN SPATIAL COVERAGE DUE TO A BACK DOOR
COLD FRONTAL PLUNGE. HIGHER DEWPOINTS AND HUMIDITY WILL GET PUSHED
WESTWARD OVERNIGHT DUE TO THE FRONTAL PUSH AND MAKE IT TO THE
CONTINENTAL DIVIDE...PERHAPS A BIT FURTHER.
THE HIGHER MOISTURE WILL SET THE STAGE FOR SOME WETTING RAIN
POSSIBILITIES BETWEEN THE DIVIDE AND CENTRAL MTNS AND ADJACENT HIGH
PLAINS ON SATURDAY. HUMIDITY VALUES WILL BE HIGHER ACROSS
WESTERN/CENTRAL AREAS COMPARED TO TODAYS RESULTS. TEMPS WILL ALSO
COOL AND BE NEAR TO ABOVE NORMAL ALONG AND WEST OF THE DIVIDE AND
BELOW NORMAL TO THE EAST OF THE DIVIDE. THE SURFACE WIND FLOW IS NOT
EXPECTED TO BE TOO STRONG EXCEPT FOR NEAR THE CENTRAL MTN GAPS
DURING THE MORNING HOURS.
THE SUBTROPICAL RIDGE IS STILL DEPICTED TO BUILD OVER THE AREA
SUNDAY THROUGH EARLY NEXT WEEK. MOISTURE TRAPPED WITHIN THE RIDGE
WILL GRADUALLY MIX OUT IN THE FORM OF ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS. THIS ACTIVITY WILL TREND DRIER AS THE DAYS
PROGRESS AND LOOK FOR SMALL FOOTPRINTS OF MARGINALLY WETTING RAIN BY
MONDAY. GUSTY OUTFLOW WINDS WOULD REMAIN A CONCERN. THE ACTIVITY
SHOULD BE MUCH LESS BY TUESDAY. BOTH THE ECMWF/GFS SUPPORT THIS
TREND. ECMWF IS A BIT MORE BULLISH FOR DRYLINE STORMS ACROSS THE
EAST ON TUESDAY HOWEVER.
THE SURFACE WIND GRADIENT SHOULD PICK UP DURING THE EARLIER HALF OF
NEXT WEEK AS THE RIDGE GRADUALLY BREAKS DOWN AND ALLOWS THE WINDS
ALOFT TO STRENGTHEN. ABUNDANT MIXING HEIGHTS SHOULD LEAD TO DEEP
MIXING AND PROVIDE GUSTIER WIND FLOWS...ESPECIALLY TUES/WED. WENT A
LITTLE ABOVE MODEL GUIDANCE FOR THIS PERIOD. DRY SLOTTING WILL ALSO
LOWER SURFACE HUMIDITY VALUES AND PROVIDE SEVERAL HOURS OF SINGLE
DIGITS ACROSS WESTERN/CENTRAL AREAS. LOCALIZED STRONG WIND/LOW
HUMIDITY AND HIGHER HAINES VALUES WILL START TO SHOW UP DURING THIS
PERIOD ALTHOUGH FUEL CONDITIONS ARENT TOO BAD...ESPECIALLY WITH AN
INFLUX OF GREENUP. CONFIDENCE IS MODERATE TO HIGH BASED ON THE
RECENT TRENDS IN THE MODELS BUT THIS WOULD BE A PATTERN CHANGE OF
SORTS.
ANOTHER PACIFIC TROUGH MAY SHARPEN UP TO THE WEST DURING LATE NEXT
WEEK AND COULD PROVIDE ANOTHER ROUND OF SHOWERS/STORMS ACROSS THE
FORECAST AREA. ECMWF MODELS APPEARS TO BE MORE BULLISH FOR THAT
TREND VERSUS THE GFS BUT WILL MONITOR. STORMS COULD INITIALLY START
OUT ON THE DRIER SIDE ACROSS WESTERN/CENTRAL AREAS.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
43
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1009 PM EDT FRI MAY 29 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BE OVER THE REGION THROUGH EARLY
SATURDAY. A STRONG SURFACE COLD FRONT WILL APPROACH FROM THE
NORTHWEST SATURDAY AFTERNOON AND CROSS THE AREA OVERNIGHT. THIS
FRONT WILL STALL OUT SOUTH OF OUR FORECAST AREA AND BECOME A FOCUS
FOR SEVERAL WAVES OF SHOWERS DURING THE FIRST PART OF THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
AS OF 1009 PM EDT FRIDAY...MOSTLY CLEAR SKIES/FEW HIGH CLOUDS AND
LIGHT, DECOUPLED WINDS THUS FAR THIS EVENING HAVE ALLOWED HOURLY
TEMPS TO FALL A BIT MORE QUICKLY THAN PRIOR EXPECTATIONS IN THE
ST. LAWRENCE VALLEY. SO THE MAIN ADJUSTMENT WITH THIS UPDATE WAS
TO LOWER MIN TEMPS BY A FEW DEGREES THROUGH MIDNIGHT. HOWEVER, AS
WINDS STRENGTHEN FROM THE SOUTHWEST AFTER MIDNIGHT AND WARM/MOIST
ADVECTION BEGINS, SHOULD SEE TEMPS HOVER STEADY AND RISE INTO THE
MORNING HOURS. LATEST HRRR GUIDANCE CONTINUES TO SUGGEST SPOTTY
LIGHT SHOWERS IN THE ST. LAWRENCE VALLEY AND ADIRONDACKS AREAS
LATER IN THE OVERNIGHT, SO ULTIMATELY OPTED TO KEEP SLIGHT CHANCE
OF SHOWERS GOING. LOWS GENERALLY IN THE UPPER 50S TO MID/UPPER
60S.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 415 PM EDT FRIDAY...COLD FRONT APPROACHES FROM THE
NORTHWEST SATURDAY AND SHOWERS AND THUNDERSTORMS DEVELOP OUT AHEAD
OF THIS FEATURE ON SATURDAY AFTERNOON. BEST CHANCE FOR
THUNDERSTORMS APPEARS TO BE AFTER 18Z...AND MAINLY NORTHERN NEW
YORK AND THE CHAMPLAIN VALLEY. OUR REGION CONTINUES TO BE UNDER A
MARGINAL RISK OUT OF SPC. BETTER DYNAMICS AND STRONGER SHEAR WILL
BE WELL NORTH OF THE AREA...CLOSER TO STRONG SHORT WAVE TROF
MOVING ACROSS ONTARIO AND QUEBEC. DAYTIME MAX TEMPS WILL REACH THE
MID 70S TO MID 80S. CAPE VALUES REACH OVER 2000 IN THE SAINT
LAWRENCE VALLEY. OVERNIGHT AS THE FRONT CONTINUES ACROSS OUR
FORECAST AREA AND WITH LOSS OF DAYTIME HEATING EXPECT CONVECTION
TO END AND JUST SOME SHOWERS CONTINUING. COLD FRONT WILL STALL OUT
TO OUR SOUTH AND BECOME THE FOCUS FOR SEVERAL ROUNDS OF
PRECIPITATION. SUNDAY NIGHT WILL SEE SHOWERS MOVE ACROSS NEW YORK
AND SOUTHERN NEW ENGLAND...HAVE SOME LIKELY POPS MENTIONED IN OUR
SOUTHERN ZONES. TEMPERATURES WILL BE MUCH COOLER ON SUNDAY AS
REGION IS IN THE COOL SECTOR BEHIND COLD FRONT...MAX TEMPS WILL
ONLY BE IN THE UPPER 50S AND LOWER 60S...A GOOD 20 DEGREES COOLER
THAN SATURDAY. SUNDAY NIGHT TEMPERATURES WILL DROP INTO THE 40S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 400 PM EDT FRIDAY...RATHER TRANQUIL EXTENDED FORECAST PERIOD
FORESEEN BASED ON CONSENSUS OF 00Z GFS/GFS ENSEMBLE MEAN AND 00Z
ECMWF. DEEP-LAYER NWLY FLOW ON ERN PERIPHERY OF SFC ANTICYCLONE
BUILDING EWD FROM THE GREAT LAKES REGION WILL PROVIDE DRIER
CONDITIONS AND MORE SEASONABLE TEMPERATURES TO START THE PERIOD
WEDNESDAY NIGHT. ANTICIPATE MOSTLY CLEAR SKIES...AND IF SURFACE
WINDS DROP OFF SUFFICIENTLY...SHOULD SEE OVERNIGHT LOWS RANGING
FROM NEAR FREEZING IN THE NORTHERN ADIRONDACKS AND FAR
NORTHEASTERNVT...TO AROUND 40F IN THE CHAMPLAIN VALLEY REGION.
AFOREMENTIONED SURFACE HIGH BUILDS SLOWLY EWD ACROSS THE
NORTHEASTERN CONUS PROVIDING PLEASANT/MOSTLY CLEAR CONDITIONS
THURSDAY THROUGH AT LEAST THE FIRST HALF OF FRIDAY. HIGHS WILL BE
IN THE MID 60S THURSDAY...BEFORE MODERATING BACK INTO THE LOW 70S
ON FRIDAY.
SOME DIFFERENCES BETWEEN 00Z GFS AND 00Z ECMWF CONCERNING
POTENTIAL SHORTWAVE TROUGH MOVING EWD FROM THE GREAT LAKES FRIDAY
NIGHT INTO SATURDAY. THE GFS IS MORE ROBUST WITH THIS
FEATURE...AND TRACKS STRONGEST UVV ACROSS OUR SRN ZONES LATE
FRIDAY NIGHT INTO SATURDAY. THE 00Z ECMWF - ON THE OTHER HAND -
KEEPS BEST PRECIPITATION CHANCES TO OUR SOUTH. THE OFFICIAL
FORECAST INDICATES SOME INCREASING CLOUDS LATER FRIDAY...FOLLOWED
BY 15-30 POPS FOR SHOWER ACTIVITY FRIDAY NIGHT THRU
SATURDAY...WITH HIGHEST POP VALUES ACROSS SRN ZONES. CLOUDS COULD
KEEP TEMPS IN THE UPR 60S TO AROUND 70F FOR SATURDAY...BEFORE
TRENDING WARMING (LOW-MID 70S) WITH BETTER POTENTIAL FOR SUNSHINE
ON SUNDAY.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR (POSSIBLE MVFR MIST AT MPV) WITH
INCREASING SOUTH WINDS THROUGH OVERNIGHT. PRIMARY AVIATION FOCUS
WILL BE IN THE LATTER HALF OF THE TAF PERIOD, DUE TO GUSTY SOUTH
WINDS AND POTENTIAL FOR SHOWERS AND THUNDERSTORMS INTO SATURDAY
AFTERNOON/EVENING.
MOSTLY CLEAR WITH SCT-BKN CIRRUS CLOUDS INTO THE OVERNIGHT
TONIGHT. I`VE CONTINUED MENTION OF 4SM BR AT MPV AFTER 08Z,
THOUGH ENOUGH LOW-LEVEL FLOW MAY PRECLUDE MUCH IF ANY MIST FROM
DEVELOPING. INITIALLY LIGHT/VARIABLE WINDS BUT BECOME SOUTH 7-10
KTS.
CONTINUED MID- TO HIGH CLOUDS INTO SATURDAY. STRENGTHENING
GRADIENT AHEAD OF SURFACE COLD FRONT SHOULD ALSO ALLOW FOR
SOUTHERLY WINDS TO FURTHER INCREASE INTO THE 10-15 KT RANGE WITH
GUSTS 25-28 KTS. SHOWER/THUNDERSTORM COVERAGE LIKELY TO BE MORE
SCATTERED, BUT THREAT SOME COULD TURN STRONG WITH GUSTY OUTFLOW
WINDS, LIGHTNING AND REDUCED VISIBILITY IN HEAVY DOWNPOURS.
BEST SHOT AT SEEING THIS ACTIVITY AFTER 18Z WOULD BE AT MSS AND
SLK, BUT I`VE ALSO SHOWN VCSH AT BTV AND PBG. MPV AND SLK NOT
LIKELY TO SEE THIS ACTIVITY UNTIL AFTER 00Z.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...A SURFACE COLD FRONT
APPROACHING FROM SOUTHEASTERN ONTARIO WILL BRING SCATTERED SHOWERS
AND THUNDERSTORMS ON SATURDAY AFTERNOON INTO SATURDAY NIGHT. SOME
STORMS COULD BE STRONG WITH LOCALIZED GUSTY AND ERRATIC OUTFLOW
WINDS...HEAVY RAINFALL...AND FREQUENT LIGHTNING...MAINLY MID
AFTERNOON THROUGH EARLY EVENING HOURS SATURDAY. BRIEF IFR
CONDITIONS CAN BE EXPECTED WITH ANY THUNDERSTORM ACTIVITY.
MODERATELY STRONG GRADIENT WINDS (SOUTH TO SOUTHWEST AT 15-25 KTS)
WILL CONTINUE THROUGH THE EARLY EVENING PERIOD. PERIODS OF RAIN
CONTINUE DURING SATURDAY NIGHT WITH DEVELOPING N-NW WINDS BEHIND
THE SURFACE COLD FRONT. TRENDING VFR ACROSS NORTHERN AREAS DURING
THE DAYLIGHT HOURS SUNDAY...BUT STALLING FRONTAL ZONE MAY RESULT
IN POSSIBLE MVFR SHOWERS AT TIMES SUNDAY NIGHT INTO
MONDAY...MAINLY FOR RUT/MPV. AVIATION WX CONDITION PREDICTABILITY
LOW AT THIS POINT FROM MONDAY NIGHT THRU WEDNESDAY.
&&
.MARINE...
AS OF 400 PM EDT FRIDAY...A COLD FRONT WILL MOVE ACROSS THE AREA
SATURDAY AFTERNOON AND OVERNIGHT. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED. A LAKE THUNDERSTORM ADVISORY MAY BE
NEEDED FOR LAKE CHAMPLAIN SATURDAY AFTERNOON AND SATURDAY NIGHT.
SOUTH WINDS WILL INCREASE TO 15 TO 25 KNOTS ON SATURDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES/LOCONTO
SHORT TERM...NEILES
LONG TERM...BANACOS
AVIATION...BANACOS/LOCONTO
MARINE...NEILES
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
739 PM EDT FRI MAY 29 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BE OVER THE REGION THROUGH EARLY
SATURDAY. A STRONG SURFACE COLD FRONT WILL APPROACH FROM THE
NORTHWEST SATURDAY AFTERNOON AND CROSS THE AREA OVERNIGHT. THIS
FRONT WILL STALL OUT SOUTH OF OUR FORECAST AREA AND BECOME A FOCUS
FOR SEVERAL WAVES OF SHOWERS DURING THE FIRST PART OF THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
AS OF 739 PM EDT FRIDAY...FRIDAY AFTERNOON CLOSES WITH FILTERED
SUNSHINE ACROSS THE NORTH COUNTRY, AS MID-LEVEL MOISTURE SPILLS IN
ON THE WESTERN END OF A DEEP-LAYER ANTICYCLONE CENTERED OVER LONG
ISLAND/SOUTHERN NEW ENGLAND. THOUGH LOOKING AT A GENERALLY QUIET
EVENING ALL THINGS CONSIDERED, SURFACE ANALYSIS DEPICTS A SUBTLE
SURFACE TROUGH FROM WESTERN PA CURRENTLY TRIGGERING SHOWERS AND
THUNDERSTORMS IN THAT VICINITY. THAT TROUGH SEPARATES MORE
COMFORTABLE DEWPOINTS IN THE 50S IN PLACE, TO A MORE MOIST/HUMID
AIRMASS WITH MID-60S DEWPOINTS. THIS FEATURE WILL LIFT NORTHEAST
TOWARDS OUR AREA AFTER MIDNIGHT. MOST HI-RES GUIDANCE INDICATE A
GENERALLY DRY PASSAGE, BUT A FEW, SUCH AS THE BTV-4 WRF AND TO A
LESSER EXTENT MOST RECENT HRRR OUTPUT, SHOW SOME LIGHT SHOWERS
ACROSS ST. LAWRENCE VALLEY INTO THE ADIRONDACKS REGION AFTER
MIDNIGHT. FOR NOW, I`VE KEPT SLIGHT CHANCE SHOWERS GOING IN THIS
AREA AND WILL RE-EVAL WITH TRENDS IN RADAR AND LATER EVENING
GUIDANCE.
OTHERWISE, PRIMARY CHALLENGE WILL BE TIMING WHEN COOLING HALTS
ACROSS THE NORTH COUNTRY, IN THE FACE OF WARM/MOIST ADVECTION AND
INCREASING SOUTHWEST WINDS. THIS HAPPENS SOONER FURTHEST WEST
(TOWARD MIDNIGHT) WITH LONGER IN EASTERN VERMONT. LOWS TONIGHT
TO RANGE IN THE UPPER 50S IN EASTERN VERMONT, BUT WILL BE SOME 10
DEGREES WARMER IN THE CHAMPLAIN AND ST. LAWRENCE VALLEYS.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 415 PM EDT FRIDAY...COLD FRONT APPROACHES FROM THE
NORTHWEST SATURDAY AND SHOWERS AND THUNDERSTORMS DEVELOP OUT AHEAD
OF THIS FEATURE ON SATURDAY AFTERNOON. BEST CHANCE FOR
THUNDERSTORMS APPEARS TO BE AFTER 18Z...AND MAINLY NORTHERN NEW
YORK AND THE CHAMPLAIN VALLEY. OUR REGION CONTINUES TO BE UNDER A
MARGINAL RISK OUT OF SPC. BETTER DYNAMICS AND STRONGER SHEAR WILL
BE WELL NORTH OF THE AREA...CLOSER TO STRONG SHORT WAVE TROF
MOVING ACROSS ONTARIO AND QUEBEC. DAYTIME MAX TEMPS WILL REACH THE
MID 70S TO MID 80S. CAPE VALUES REACH OVER 2000 IN THE SAINT
LAWRENCE VALLEY. OVERNIGHT AS THE FRONT CONTINUES ACROSS OUR
FORECAST AREA AND WITH LOSS OF DAYTIME HEATING EXPECT CONVECTION
TO END AND JUST SOME SHOWERS CONTINUING. COLD FRONT WILL STALL OUT
TO OUR SOUTH AND BECOME THE FOCUS FOR SEVERAL ROUNDS OF
PRECIPITATION. SUNDAY NIGHT WILL SEE SHOWERS MOVE ACROSS NEW YORK
AND SOUTHERN NEW ENGLAND...HAVE SOME LIKELY POPS MENTIONED IN OUR
SOUTHERN ZONES. TEMPERATURES WILL BE MUCH COOLER ON SUNDAY AS
REGION IS IN THE COOL SECTOR BEHIND COLD FRONT...MAX TEMPS WILL
ONLY BE IN THE UPPER 50S AND LOWER 60S...A GOOD 20 DEGREES COOLER
THAN SATURDAY. SUNDAY NIGHT TEMPERATURES WILL DROP INTO THE 40S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 400 PM EDT FRIDAY...RATHER TRANQUIL EXTENDED FORECAST PERIOD
FORESEEN BASED ON CONSENSUS OF 00Z GFS/GFS ENSEMBLE MEAN AND 00Z
ECMWF. DEEP-LAYER NWLY FLOW ON ERN PERIPHERY OF SFC ANTICYCLONE
BUILDING EWD FROM THE GREAT LAKES REGION WILL PROVIDE DRIER
CONDITIONS AND MORE SEASONABLE TEMPERATURES TO START THE PERIOD
WEDNESDAY NIGHT. ANTICIPATE MOSTLY CLEAR SKIES...AND IF SURFACE
WINDS DROP OFF SUFFICIENTLY...SHOULD SEE OVERNIGHT LOWS RANGING
FROM NEAR FREEZING IN THE NORTHERN ADIRONDACKS AND FAR
NORTHEASTERNVT...TO AROUND 40F IN THE CHAMPLAIN VALLEY REGION.
AFOREMENTIONED SURFACE HIGH BUILDS SLOWLY EWD ACROSS THE
NORTHEASTERN CONUS PROVIDING PLEASANT/MOSTLY CLEAR CONDITIONS
THURSDAY THROUGH AT LEAST THE FIRST HALF OF FRIDAY. HIGHS WILL BE
IN THE MID 60S THURSDAY...BEFORE MODERATING BACK INTO THE LOW 70S
ON FRIDAY.
SOME DIFFERENCES BETWEEN 00Z GFS AND 00Z ECMWF CONCERNING
POTENTIAL SHORTWAVE TROUGH MOVING EWD FROM THE GREAT LAKES FRIDAY
NIGHT INTO SATURDAY. THE GFS IS MORE ROBUST WITH THIS
FEATURE...AND TRACKS STRONGEST UVV ACROSS OUR SRN ZONES LATE
FRIDAY NIGHT INTO SATURDAY. THE 00Z ECMWF - ON THE OTHER HAND -
KEEPS BEST PRECIPITATION CHANCES TO OUR SOUTH. THE OFFICIAL
FORECAST INDICATES SOME INCREASING CLOUDS LATER FRIDAY...FOLLOWED
BY 15-30 POPS FOR SHOWER ACTIVITY FRIDAY NIGHT THRU
SATURDAY...WITH HIGHEST POP VALUES ACROSS SRN ZONES. CLOUDS COULD
KEEP TEMPS IN THE UPR 60S TO AROUND 70F FOR SATURDAY...BEFORE
TRENDING WARMING (LOW-MID 70S) WITH BETTER POTENTIAL FOR SUNSHINE
ON SUNDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR (POSSIBLE MVFR MIST AT MPV) WITH
INCREASING SOUTH WINDS THROUGH OVERNIGHT. PRIMARY AVIATION FOCUS
WILL BE IN THE LATTER HALF OF THE TAF PERIOD, DUE TO GUSTY SOUTH
WINDS AND POTENTIAL FOR SHOWERS AND THUNDERSTORMS INTO SATURDAY
AFTERNOON/EVENING.
MOSTLY CLEAR WITH SCT-BKN CIRRUS CLOUDS INTO THE OVERNIGHT
TONIGHT. I`VE CONTINUED MENTION OF 4SM BR AT MPV AFTER 08Z,
THOUGH ENOUGH LOW-LEVEL FLOW MAY PRECLUDE MUCH IF ANY MIST FROM
DEVELOPING. INITIALLY LIGHT/VARIABLE WINDS BUT BECOME SOUTH 7-10
KTS.
CONTINUED MID- TO HIGH CLOUDS INTO SATURDAY. STRENGTHENING
GRADIENT AHEAD OF SURFACE COLD FRONT SHOULD ALSO ALLOW FOR
SOUTHERLY WINDS TO FURTHER INCREASE INTO THE 10-15 KT RANGE WITH
GUSTS 25-28 KTS. SHOWER/THUNDERSTORM COVERAGE LIKELY TO BE MORE
SCATTERED, BUT THREAT SOME COULD TURN STRONG WITH GUSTY OUTFLOW
WINDS, LIGHTNING AND REDUCED VISIBILITY IN HEAVY DOWNPOURS.
BEST SHOT AT SEEING THIS ACTIVITY AFTER 18Z WOULD BE AT MSS AND
SLK, BUT I`VE ALSO SHOWN VCSH AT BTV AND PBG. MPV AND SLK NOT
LIKELY TO SEE THIS ACTIVITY UNTIL AFTER 00Z.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...A SURFACE COLD FRONT
APPROACHING FROM SOUTHEASTERN ONTARIO WILL BRING SCATTERED SHOWERS
AND THUNDERSTORMS ON SATURDAY AFTERNOON INTO SATURDAY NIGHT. SOME
STORMS COULD BE STRONG WITH LOCALIZED GUSTY AND ERRATIC OUTFLOW
WINDS...HEAVY RAINFALL...AND FREQUENT LIGHTNING...MAINLY MID
AFTERNOON THROUGH EARLY EVENING HOURS SATURDAY. BRIEF IFR
CONDITIONS CAN BE EXPECTED WITH ANY THUNDERSTORM ACTIVITY.
MODERATELY STRONG GRADIENT WINDS (SOUTH TO SOUTHWEST AT 15-25 KTS)
WILL CONTINUE THROUGH THE EARLY EVENING PERIOD. PERIODS OF RAIN
CONTINUE DURING SATURDAY NIGHT WITH DEVELOPING N-NW WINDS BEHIND
THE SURFACE COLD FRONT. TRENDING VFR ACROSS NORTHERN AREAS DURING
THE DAYLIGHT HOURS SUNDAY...BUT STALLING FRONTAL ZONE MAY RESULT
IN POSSIBLE MVFR SHOWERS AT TIMES SUNDAY NIGHT INTO
MONDAY...MAINLY FOR RUT/MPV. AVIATION WX CONDITION PREDICTABILITY
LOW AT THIS POINT FROM MONDAY NIGHT THRU WEDNESDAY.
&&
.MARINE...
AS OF 400 PM EDT FRIDAY...A COLD FRONT WILL MOVE ACROSS THE AREA
SATURDAY AFTERNOON AND OVERNIGHT. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED. A LAKE THUNDERSTORM ADVISORY MAY BE
NEEDED FOR LAKE CHAMPLAIN SATURDAY AFTERNOON AND SATURDAY NIGHT.
SOUTH WINDS WILL INCREASE TO 15 TO 25 KNOTS ON SATURDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES/LOCONTO
SHORT TERM...NEILES
LONG TERM...BANACOS
AVIATION...BANACOS/LOCONTO
MARINE...NEILES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
835 PM EDT FRI MAY 29 2015
.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC WILL
EXTEND INTO THE REGION THROUGH SATURDAY. A COLD FRONT WILL DROP INTO
THE MID ATLANTIC AND SOUTHERN APPALACHIANS ON SUNDAY AND MOVE
INTO THE CAROLINAS ON MONDAY AND TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM FRIDAY...
NEAR TERM: THROUGH TONIGHT: SURFACE HIGH PRESSURE REALLY DOMINATING
THE PATTERN THE PAST FEW DAYS AND TODAY IS REALLY NO DIFFERENT. WITH
VIRTUALLY NO FORCING ALOFT (AS EVIDENCED BY FORECAST SOUNDINGS WHICH
ARE SHOWING LESS THAN 10 KTS ALL THE WAY UP THROUGH 30 KFT) ALL OF
THE ACTION WILL BE SURFACE BASED WITH MUCH OF IT OCCURRING NW OF THE
FORECAST AREA. THE TRIAD WILL CONTINUE TO HAVE SHOWERS AND POSSIBLY
A WEAK THUNDERSTORM IN THE AREA FOR THE REMAINDER OF THE AFTERNOON
AND POSSIBLY INTO THIS EVENING. RAP AND NAM FORECAST SOUNDINGS SHOW
THE BEST INSTABILITY OCCURRING RIGHT NOW AND ACTUALLY DIMINISHING
THROUGH THE AFTERNOON SO WHAT IS OUT THERE NOW COULD BE THE PEAK OF
IT BUT WILL REQUIRE WATCHING THROUGH THE AFTERNOON. ANYTHING THAT
FORMS HAS BEEN SLOWLY DRIFTING NORTHWARD AND OUT OF THE AREA. HIGHS
THIS AFTERNOON SHOULD TOP OUT IN THE MID TO UPPER 80S WITH THE
SANDHILLS RECEIVING THE HIGHEST TEMPERATURES. HIGH RESOLUTION MODELS
ALSO HINTED AT SOME SHOWERS FORMING ON THE SEA BREEZE BUT SO FAR
THESE HAVE BEEN VERY MINIMAL AND CONFINED TO THE COAST.
OVERNIGHT TONIGHT EXPECT A CHANCE FOR SOME LOW STRATUS...ESPECIALLY
IN THE TRIAD WHERE CEILINGS AS LOW AS IFR COULD SHOW UP FOR A FEW
HOURS AROUND 12Z. ELSEWHERE MVFR CEILINGS ARE MORE LIKELY. RETURN TO
VFR IS EXPECTED AFTER 15Z ON SATURDAY MORNING. LOWS OVERNIGHT IN THE
MID 60S.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 315 PM FRIDAY...
SATURDAY AND SATURDAY NIGHT: SURFACE HIGH PRESSURE BUILDS BACK IN A
LITTLE FURTHER THAN RECENT DAYS AND THE UPSHOT IS POSSIBLY A DRIER
DAY IN THE TRIAD THAN PREVIOUS AFTERNOONS. WILL STILL CARRY A SLIGHT
CHANCE OF SHOWERS IN THE WEST TOMORROW BUT CONTINUED MINIMAL SHEAR
AND EVEN LESS INSTABILITY THAN TODAY DONT BODE WELL FORE CONVECTION
PROSPECTS. THIS IS BACKED UP BY CAMS WHICH SHOW MINIMAL ACTIVITY
TOMORROW AFTERNOON. INSTEAD EXPECT ANOTHER DAY OF WARM RETURN FLOW
WITH HIGHS AGAIN MOSTLY IN THE UPPER 80S. LOWS SATURDAY NIGHT IN THE
MIDDLE 60S ONCE AGAIN.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 325 PM FRIDAY...
A LARGE SCALE PATTERN CHANGE IS AFOOT...WHEREIN THE WRN ATLANTIC
RIDGE WILL FINALLY GIVE WAY TO A SOUTHWARD DIP IN THE WESTERLIES
OVER THE CONUS. THIS WILL BRING IMPROVING CHANCES FOR MUCH-NEEDED
RAINFALL BEGINNING EARLY IN THE WORK WEEK. THE VAST MAJORITY OF
CENTRAL NC HAS SEEN VERY LITTLE RAIN IN THE LAST COUPLE OF WEEKS...
BETWEEN 1 AND 2 INCHES BELOW NORMAL IN THE LAST 14 DAYS ACCORDING TO
WATER.WEATHER.GOV/PRECIP/.
SUNDAY SHOULD BE OUR LAST STEAMY BUT MOSTLY DRY DAY. THE APPROACHING
COLD FRONT IS EXPECTED TO STRETCH ACROSS THE MASON DIXON LINE DOWN
THROUGH ERN KY LATE SUN... WITH ITS ASSOCIATED MID LEVEL TROUGH
EXTENDING FROM THE GREAT LAKES TO THE LOWER MISS VALLEY AS THE WRN
ATLANTIC RIDGE HOLDS ON FOR ONE MORE DAY. LATEST MODEL OUTPUT SHOWS
SCATTERED TO NUMEROUS SHOWERS/STORMS POPPING UP BY AFTERNOON OVER
THE HIGHER TERRAIN TRACKING TO THE NE WITHIN THE WEAK MEAN STEERING
FLOW AROUND THE RIDGE. THIS CONVECTION IS EXPECTED TO WEAKEN DURING
THE EVENING BUT EASE EASTWARD INTO THE NORTHWEST CWA SUN NIGHT...
FOLLOWING THE PROGRESSION OF THE NRN PORTION OF THE MID LEVEL TROUGH
INTO THE NORTHEAST STATES THROUGH MON. THE REST OF THE CWA SHOULD
REMAIN MOSTLY DRY (ALTHOUGH AN ISOLATED SLOW-MOVING CELL OR TWO IS
CERTAINLY POSSIBLE) GIVEN THE SOMEWHAT DRY LOW LEVELS (LIMITING
CAPE) AND DRY AIR THROUGH THE COLUMN (BELOW NORMAL PW OVER ERN HALF
OF CWA). HIGHS SUN 85-90. LOWS SUN NIGHT MAINLY IN THE UPPER 60S
WITH CONVECTIVE DEBRIS CLOUDS AND A SMALL CHANCE OF SHOWERS OVER THE
NRN/WRN CWA OVERNIGHT.
WHILE WE SHOULD SEE A PIEDMONT TROUGH FORMING (OR BECOMING BETTER
DEFINED) OVER THE CWA MON... MODELS ARE KEEPING A THERMAL RIDGE
ACROSS OUR AREA WITH THE FRONTAL ZONE HOLDING TO OUR NW THROUGH THE
DAY... A FUNCTION OF THE SLOW SPEED AND LOW AMPLITUDE OF THE MID
LEVEL TROUGH TO OUR WEST. WE`LL NEED TO WAIT FOR ADDITIONAL ENERGY
TO DROP FROM SW ONTARIO DOWN THROUGH THE GREAT LAKES STARTING MON IN
ORDER FOR THE TROUGH TO MAKE ANY MEANINGFUL EASTWARD PROGRESS. ALL
OF THIS WILL SERVE TO DELAY COOLING INTO NC UNTIL THE SURFACE FRONT
DROPS INTO NC TUE NIGHT OR EARLY WED. BOTH MOISTURE AND FORCING FOR
ASCENT WILL DEEPEN AND INCREASE AHEAD OF THE FRONT... AND BY LATE
MON AFTERNOON WE SHOULD SEE GOOD COVERAGE OF SHOWERS AND STORMS
PARTICULARLY OVER THE WRN AND SW CWA WHERE LOW LEVEL MOISTURE
POOLING SHOULD BE GREATEST. COVERAGE AND INTENSITY WILL WANE MON
NIGHT WITH LOSS OF HEATING... BUT NOT GO AWAY ENTIRELY GIVEN THE
PERSISTENCE OF ELEVATED INSTABILITY OVERNIGHT AND ABOVE-NORMAL PW.
MODERATE INSTABILITY AND HIGH MOISTURE SHOULD PERSIST AREAWIDE
TUE... SUPPORTING ABOVE NORMAL CHANCES FOR SHOWERS AND STORMS (50-
60%). EXPECT HIGH COVERAGE AGAIN WED ACROSS ALL BUT THE NW AS THE
FRONT SETTLES INTO THE NRN/WRN CWA. THE GFS/ECMWF SOLUTIONS DIVERGE
WITH THE LATTER SHOWING A DEEPER TROUGH JUST TO OUR IMMEDIATE WEST
TUE AND SHIFTING OVER THE ERN STATES WED... WHILE THE GFS KEEPS THE
STREAMS UNPHASED WITH A CUTOFF MID LEVEL LOW OVER THE LOWER MISS
VALLEY. PREFER THE WEAKER-FLOW GFS WITH THE FRONT LOITERING ACROSS
ERN AND SRN NC THROUGH THU/FRI... AS THE ONCE-COOL SURFACE HIGH
CENTERED OVER THE ERN GREAT LAKES EARLY WED MODIFIES AND STARTS TO
DRIFT OFF THE NORTHEAST COAST BY FRI. THE FRONT SHOULD BE MOSTLY
WASHED OUT AND BE OVERTAKEN BY COASTAL INVERTED TROUGHING OVER THE
SOUTHEAST COAST. WILL TREND POPS TOWARD MORE CLIMATOLOGICALLY NORMAL
VALUES THU/FRI -- 25-35% CHANCES MAINLY IN THE EAST AND SOUTH --
GIVEN THE DECREASING DEEP LAYER SHEAR AND WEAKENING FORCING
FEATURES.
DESPITE WHAT SHOULD BE A PERIOD OF MOSTLY CLOUDY SKIES FROM
CONVECTIVE DEBRIS AND LIFTING MORNING STRATUS ON MON... WE SHOULD
SEE ENOUGH HEATING WITHIN THE WARM SECTOR TO PUSH TEMPS UP TO HIGHS
FROM THE MID 80S TO AROUND 90 (COOLEST NW AND FAR NORTH). HIGH TEMPS
SHOULD SLIP BACK CLOSER TO NORMAL TUE GIVEN THE EXPECTED
CONSIDERABLE CLOUDINESS... WITH THESE CLOUDS EQUATING TO MILD/HUMID
OVERNIGHT LOWS THROUGH TUE NIGHT. SLIGHTLY BELOW NORMAL TEMPS WED...
THEN TRENDING BACK TOWARD NEAR OR SLIGHTLY ABOVE NORMAL THU/FRI AS
THE FRONT WASHES OUT AND THE RESIDENT AIR MASS MODIFIES. -GIH
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 835 PM FRIDAY...
24-HR TAF PERIOD: ASIDE FROM A POTENTIAL FOR SUB-VFR CEILINGS OR FOG
DURING THE PRE-DAWN/EARLY MORNING HOURS (08-13Z)...PRIMARILY AT THE
INT/GSO TERMINALS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH
THE TAF PERIOD IN ASSOC/W A PERSISTENT UPPER LEVEL RIDGE ALONG THE
EASTERN SEABOARD.
LOOKING AHEAD: ASIDE FROM A POTENTIAL FOR SUB-VFR CEILINGS/FOG
DURING THE EARLY MORNING (08-13Z) AND CONVECTION DURING THE LATE
AFT/EVE (20-01Z)...PRIMARILY AT THE INT/GSO TERMINALS...EXPECT VFR
CONDITIONS TO PREVAIL THROUGH THE WEEKEND. CHANCES FOR EARLY MORNING
STRATUS/FOG AND AFT/EVE CONVECTION WILL INCREASE AT ALL TERMINALS
(PARTICULARLY INT/GSO) MONDAY INTO TUESDAY AS THE UPPER LEVEL RIDGE
WEAKENS AND A SLOW-MOVING UPPER LEVEL TROUGH APPROACHES THE
CAROLINAS/MID-ATLANTIC FROM THE WEST. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...ELLIS
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
329 PM EDT THU MAY 28 2015
.SYNOPSIS...
SEASONABLE WEATHER WILL PREVAIL MUCH OF THE PERIOD AS WEAK HIGH
PRESSURE REMAINS OFFSHORE. DRY AIR ALOFT WILL LIMIT PRECIPITATION
WITH ONLY ISOLATED ACTIVITY ANTICIPATED THROUGH THE WEEKEND. AN
APPROACHING BUT WEAKENING COLD FRONT WILL BRING A SLIGHTLY BETTER
CHANCE OF RAINSHOWERS AND A FEW THUNDERSTORMS EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM THURSDAY...DRIER DESCENDING AIR ALOFT CONTINUES TO
CAP SURFACE-BASED AIR PARCEL CLIMBS. ACROSS THE DEEPER INTERIOR
WHERE HIGHER COLUMN MOISTURE WILL LINGER LONGER...A FEW ISOLATED
SHOWERS REMAIN POSSIBLE THROUGH AFTERNOON.
A BAND OF DRY SUBSIDENT AIR ACROSS THE WESTERN PERIPHERY OF A
LANDWARD MIGRATING WESTERN ATLANTIC UPPER LOW WILL CURTAIL
CONVECTIVE CHANCES ACROSS SE NC AND NE SC. ISOLATED ACTIVITY
HOWEVER CANNOT BE RULED OUT OVER FAR INLAND SE NC NEAR I-95
AND ALONG THE NC/SC STATE LINE WHERE STRONG LOW-LEVEL HEATING
IS OCCURRING PRIOR TO BETTER MID-LVL DRYING. THIS ACTIVITY WOULD
LIKELY BE SHOWERS ONLY IF NOT JUST MODERATE CUMULUS. GREATER
COVERAGE WILL REMAIN N AND W OF OUR AREA INTO CENTRAL NORTH
CAROLINA. ANY SHOWERS THAT LINGER INTO EARLY EVENING WILL LIKELY
BE LOCATED WELL INLAND...POSSIBLY TOUCHING MARLBORO OR DARLINGTON
COUNTY. LOWER DEWPOINTS...CLEAR SKIES AND LIGHT WIND MAY RESULT IN
PATCHY FOG INTO THE PRE-DAWN OF FRIDAY. SLIGHTLY LOWER MINIMUMS
WILL RESULT AS WELL...DIPPING TO 63-66 INLAND...64-68 CLOSER TO
THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RIDGE INTO THE AREA FROM THE
NORTH AND EAST THROUGH THE PERIOD WHILE A WEAK AREA OF LOW PRESSURE
ALOFT PERSISTS OFFSHORE. GENERALLY EXPECT DRY WEATHER UNDER PARTLY
CLOUDY SKIES...THOUGH A STRAY SHOWER OR STORM IS POSSIBLE EACH DAY.
HIGHS EACH DAY WILL BE IN THE MID TO UPPER 80S WITH COOLER VALUES NEARER
THE BEACHES. LOWS EACH NIGHT WILL BE IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...RIDGE IN THE MID TO UPPER LEVELS OVER THE
SOUTHEAST ON SUNDAY WILL BEGIN TO ERODE AS NORTHERN STREAM TROUGH
DIGS DOWN OVER MISSISSIPPI VALLEY AND CUTS OFF MON INTO TUES WHILE
NORTHERN PORTION OF TROUGH MOVES EAST PUSHING A COLD FRONT SOUTH
THROUGH MID WEEK. LATEST MODELS LOOK MORE AGGRESSIVE IN TERMS OF
PUSHING THIS FRONT THROUGH THE CAROLINAS TUES INTO WED AS HIGH
PRESSURE BUILDS DOWN FROM THE NORTH BEHIND IT. AT THE SAME TIME
ATLANTIC HIGH PRESSURE AT THE SFC WILL MIGRATE EAST ALLOWING FLOW
THROUGH THE MID LEVELS TO BECOME MORE SOUTHERLY LATE SUNDAY INTO
MONDAY. CONVECTION SHOULD HOLD TO OUR WEST TO NORTHWEST ON SUNDAY
AND BE MORE ISOLATED WITH FOCUS MAINLY ASSOCIATED WITH PIEDMONT
TROUGH AND FRONT EVEN FARTHER WEST BUT BY MON INTO TUES THE FRONT
WILL GET STRETCHED OUT TO THE EAST AND THEN WILL GET PUSHED SOUTH
TUES INTO WED WITH INCREASING CHC OF SHWRS AND THUNDERSTORMS.
WHILE MON MAY BE MORE ACTIVE INLAND AND NORTH ...FRONT SHOULD MAKE
IT FAR ENOUGH SOUTH AND EAST BY WED TO PRODUCE MORE WIDESPREAD
CONVECTION ACROSS THE LOCAL AREA. BY WED INTO THURS THE FRONT SHOULD
DROP SLOWLY SOUTH WITH LINGERING CLOUDS AND MOISTURE CLEARING OUT
FROM NORTH TO SOUTH ACROSS NORTH CAROLINA BUT POSSIBLY LINGERING
ACROSS SOUTH CAROLINA WED NIGHT INTO THURS. AT THE SAME TIME THE
SOUTHERLY FLOW ON THE FRONT END OF CUTOFF LOW OVER THE LOWER
MISSISSIPPI VALLEY WILL ADVECT UPPER LEVEL CLOUDS AND MOISTURE OVER
THE SOUTHEAST. OVERALL WILL SEE INCREASING CLOUDS AND THEN GREATER
CHC OF SHWRS/TSTMS THROUGH MID WEEK NEXT WEEK. LOOKS LIKE TROPICAL
OR HYBRID TYPE WAVE/LOW MAY INTERACT WITH LINGERING FRONT OFF THE
COAST OF FLORIDA/BAHAMAS LATER IN THE WEEK.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...VFR/SCATTERED LOW/MID CLOUDS AT THE TERMINALS THIS
AFTERNOON WITH SE WINDS AROUND 10 KT. PER KLTX RADAR SHOWERS ARE
DECREASING NEAR THE INLAND TERMINALS AND DEVELOPING FURTHER TO THE
NW. FOLLOWING THE TRENDS SUGGESTED BY THE HRRR MODEL IT APPEARS
THERE IS LESS LIKELIHOOD OF VCSH AT THE INLAND TERMINALS THIS
AFTERNOON.
THIS EVENING...WINDS SLOWLY DROP BACK TO 5 KT OR LESS. AFTER 08Z
MVFR FOG POSSIBLE AT THE INLAND TERMINALS WITH MVFR VSBYS APPEAR
MOST LIKELY. AFTER 08Z THERE WILL BE AN INCREASED CHANCE OF SHOWER
ACTIVITY MOVING INTO THE COASTAL TERMINALS FROM THE ATLANTIC. ATTM
DUE TO DRY MID LEVELS ANY PRECIPITATION SHOULD BE LIGHT AND ISOLATED
....BUT LOW VFR/HIGH MVFR CIGS WILL BR POSSIBLE AT LEAST THROUGH
MID MORNING.
EXTENDED OUTLOOK...TYPICAL EARLY SUMMER PATTERN WITH MORNING FOG AND
MAINLY AFTERNOON ISOLATED/SCATTERED SHOWERS AND STORMS. OTHERWISE
EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM THURSDAY...FRIENDLY MARINE ENVIRONMENT PREVAILS WITH
RELATIVELY LIGHT ONSHORE WIND AND ESE WAVES 2-3 FEET EVERY 7-8
SECONDS. THIS REGIME WILL CONTINUE OVERNIGHT WITH NO TSTMS OR
RESTRICTIONS TO VISIBILITY EXPECTED. ISOLATED SHOWERS INTO EARLY
FRIDAY MAY DOT THE WATERS...BUT ANY ENCROACHMENT OVER THE 0-20NM
WATERS FROM THE EAST WILL BE ISOLATED AT BEST.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...WEAK E-SE FLOW IS EXPECTED THROUGH THE PERIOD
AT SPEEDS GENERALLY AOB 15 KT. SEAS WILL RUN 2 TO 3 FEET OVER
MUCH OF THE WATERS WITH 4 FOOTERS ON TAP AT 20 NM BEGINNING FRIDAY
EVENING.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 300 PM THURSDAY...ATLANTIC HIGH WILL PULL BACK TO THE EAST AS
COLD FRONT MAKES ITS WAY SOUTHEAST THROUGH MONDAY. THIS WILL ALLOW
WINDS TO COME AROUND TO THE SE-SE AND THEN EVENTUALLY SOUTH AS
FRONT GETS STRETCHED FROM WEST TO EAST INTO THE ATLANTIC AS IT HEADS
SOUTH INTO NORTH CAROLINA BY TUES. WINDS WILL REMAIN FAIRLY
LIGHT...GENERALLY 10 KTS OR LESS THROUGH MUCH OF THE PERIOD. THE
NORTHERLY SURGE BEHIND FRONT SHOULD NOT AFFECT THE SEAS UNTIL END OF
PERIOD. SEAS WILL GENERALLY REMAIN BETWEEN 2 TO 4 FT AS LONGER
PERIOD EASTERLY SWELL TRANSLATES INTO A SHORTER PERIOD SOUTHERLY
WIND CHOP.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...31
LONG TERM...RGZ
AVIATION...MRR/8
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
128 PM EDT THU MAY 28 2015
.SYNOPSIS...
SEASONABLE WEATHER WILL PREVAIL MUCH OF THE PERIOD AS WEAK HIGH
PRESSURE REMAINS OFFSHORE. DRY AIR ALOFT WILL LIMIT PRECIPITATION
WITH ONLY ISOLATED ACTIVITY ANTICIPATED THROUGH THE UPCOMING
WEEKEND. AN APPROACHING BUT WEAKENING COLD FRONT WILL BRING A
SLIGHTLY BETTER CHANCE OF RAINSHOWERS AND A FEW THUNDERSTORMS
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 128 PM THURSDAY...NO CHANGES TO THE ONGOING FORECAST WITH
THE EARLY AFTERNOON UPDATES...AS DRIER DESCENDING AIR ALOFT CAPS
SURFACE-BASED AIR PARCEL CLIMBS. ACROSS THE DEEPER INTERIOR WHERE
HIGHER COLUMN MOISTURE WILL LINGER LONGER...A FEW ISOLATED SHOWERS
REMAIN POSSIBLE THIS AFTERNOON.
A BAND OF DRY SUBSIDENT AIR ACROSS THE WESTERN PERIPHERY OF A
LANDWARD MIGRATING WESTERN ATLANTIC UPPER LOW WILL CURTAIL
CONVECTIVE CHANCES ACROSS SE NC AND NE SC TODAY. ISOLATED ACTIVITY
HOWEVER IS EXPECTED OVER INTERIOR SE NC WESTWARD NEAR I-95 ALONG
THE NC/SC STATE LINE THIS AFTERNOON AS LOW-LEVEL HEATING OCCURS
PRIOR TO MID-LEVEL DRYING FARTHER INLAND. THIS ACTIVITY HOWEVER
MAY BE SHOWERS ONLY IF NOT JUST MODERATE CUMULUS. GREATER COVERAGE
WILL LIKELY DEVELOPMENT N AND W OF OUR AREA MORESO INTO CENTRAL
NORTH CAROLINA AND INLAND OF THE NC OUTER BANKS. MAXIMUMS WILL
WARM TO NEAR 80 AT THE BEACHES AS WATER TEMPS CONTINUE TO
GRADUALLY RISE...LOW TO MIDDLE 80S COASTAL INTERIOR AND UPPER 80S
DEEPER INLAND. ANY SHOWERS THAT LINGER INTO EARLY EVENING WILL
LIKELY BE LOCATED WELL INLAND...POSSIBLY TOUCHING MARLBORO COUNTY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY... CONVECTION OUGHT TO BE PRETTY HARD TO COME BY
ON FRIDAY SAVE FOR PERHAPS ISOLATED COVERAGE WELL INLAND. THIS IS
MAINLY DUE TO SOME DRYING ALOFT AND A WEAK INVERSION DEVELOPING
AROUND 700MB. INLAND HIGH TEMPS WILL BE A FEW DEGREES ABOVE CLIMO
WHILE ONSHORE FLOW SHOULD TEMPER THINGS A BIT CLOSER TO THE COAST.
WE DO SEE A RIBBON OF MID LEVEL MOISTURE THAT PEELS AWAY FROM THE
UPPER LOW WELL OFFSHORE BUT ANY CONVECTION THAT RESULTS LIKELY ONLY
AFFECTS THE WATER OVER THE GULF STREAM. THE AFOREMENTIONED
INVERSION APPEARS TO MIX OUT IN FORECAST SOUNDINGS BY SATURDAY BUT
THE DRY AIR APPEARS PRETTY STALWART. EXPECT A SIMILAR DAY
TEMPERATURE-WISE AS WELL AS THE PROSPECTS AND FAVORED LOCATIONS FOR
ANY SCANT CONVECTION.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 AM THURSDAY... PATTERN CHANGES TAKING SHAPE ON SUNDAY
COMPARED TO THE RELATIVELY TRANQUIL SHORT TERM. LOW LEVEL MOISTURE
WILL INCREASE SLIGHTLY BUT PERHAPS MORE IMPORTANTLY THE LIGHT MID
LEVEL FLOW WILL BE TAKING ON A WEAK SOUTHWESTERLY COMPONENT AHEAD OF
A SLOW MOVING SOUTHERN BRANCH TROUGH CROSSING THE MS VALLEY. WITH
THESE FACTORS TAKING SHAPE SO GRADUALLY SUNDAY STILL LIKELY ONLY
BRINGS SLIGHT CHANCE POPS OVER MAINLY WESTERN ZONES. PREVIOUS MODELS
RUNS SUGGESTED THAT THE UPPER WAVE IN THE SOUTHERN BRANCH HELPED
INCREASED MOISTURE THAT A BACKDOOR FRONT BEING PUSHED BY THE
NORTHERN BRANCH MAY INTERACT WITH. AND WHILE THIS BOUNDARY SHOULD
STILL SAG INTO THE AREA FOR SOME UNSETTLED WEATHER TUESDAY AND/OR
WEDNESDAY IT APPEARS THAT IT WILL HAVE LITTLE HELP FROM THE SOUTHERN
SYSTEM. RATHER, THIS FEATURE NOW APPEARS TO CUT OFF AND STALL. OF
NOTE THIS TROUGH MAY BE INSTRUMENTAL BEYOND THE LONG TERM SETTING
THE STAGE FOR HYBRID OR TROPICAL DEVELOPMENT IN THE EASTERN
GOMEX...POSSIBLY AFFECTING THE REGION LATE NEXT WEEK.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...VFR/SCATTERED LOW/MID CLOUDS AT THE TERMINALS THIS
AFTERNOON WITH SE WINDS AROUND 10 KT. PER KLTX RADAR SHOWERS ARE
DECREASING NEAR THE INLAND TERMINALS AND DEVELOPING FURTHER TO THE
NW. FOLLOWING THE TRENDS SUGGESTED BY THE HRRR MODEL IT APPEARS
THERE IS LESS LIKELIHOOD OF VCSH AT THE INLAND TERMINALS THIS
AFTERNOON.
THIS EVENING...WINDS SLOWLY DROP BACK TO 5 KT OR LESS. AFTER 08Z
MVFR FOG POSSIBLE AT THE INLAND TERMINALS WITH MVFR VSBYS APPEAR
MOST LIKELY. AFTER 08Z THERE WILL BE AN INCREASED CHANCE OF SHOWER
ACTIVITY MOVING INTO THE COASTAL TERMINALS FROM THE ATLANTIC. ATTM
DUE TO DRY MID LEVELS ANY PRECIPITATION SHOULD BE LIGHT AND ISOLATED
....BUT LOW VFR/HIGH MVFR CIGS WILL BR POSSIBLE AT LEAST THROUGH
MID MORNING.
EXTENDED OUTLOOK...TYPICAL EARLY SUMMER PATTERN WITH MORNING FOG AND
MAINLY AFTERNOON ISOLATED/SCATTERED SHOWERS AND STORMS. OTHERWISE
EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 128 PM THURSDAY...WINDS BACKING FROM S TO ESE-SE TODAY WITH
A SLIGHTLY RELAXED SFC PG...RESULTING IN WIND SPEEDS AROUND 10
KT...15 KT AT PEAK SEA BREEZE THIS AFTN AND EARLY EVENING.
SIGNIFICANT SEAS AT 3 FT FROM CAPE FEAR NORTHWARD...AND 2 TO 3 FT
SOUTH OF CAPE FEAR TO SOUTH SANTEE RIVER. WILL OBSERVE A BUILDING
TREND TO SIGNIFICANT SEAS AS ILLUSTRATED BY WAVEWATCH3 AND LOCALLY
RUN NWP IN RESPONSE TO THE INCREASING E-ESE FETCH. COULD SEE 4
FOOTERS BY DAYBREAK FRI ACROSS THE WATERS OFF CAPE FEAR. PERIODS
WILL RANGE FROM 7 TO 9 SECONDS...AND COULD BE CONSIDERED A SWELL
RATHER THAN JUST WIND DRIVEN WAVES. A CHOP WILL DEVELOP ACROSS THE
INSHORE WATERS THIS AFTN/EARLY EVENING.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY... THE PRESSURE GRADIENT WILL BE QUITE WEAK ON
FRIDAY AS HIGH PRESSURE WILL BE WEAKLY SPRAWLED WEST TO EAST ACROSS
THE ATLANTIC MAINLY OFF THE ATLANTIC COAST. NORMALLY SUCH LIGHT FLOW
(CAPPED AT 10 KT) WOULD LEAD TO VERY DIMINUTIVE SEAS. HOWEVER THE
EASTERLY FETCH WILL BE LONG ENOUGH TO BRING SOME LONGER PERIOD WAVE
ENERGY INTO MOST OF THE REGION. DOMINANT WAVE PERIODS ARE FORECAST
TO BE 9 SECONDS. NEARSHORE PORTIONS OF BRUNSWICK ZONES WILL BE A BIT
SHADOWED FROM THE SWELLS. THE ONLY DISCERNIBLE DIFFERENCE HEADING
INTO SATURDAY APPEARS TO BE A SLIGHT RETREAT OF THE RIDGE AXIS
BRINGING A SOUTHEASTERLY FLOW AS OPPOSED TO SOUTHEAST.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY... THE CONTINUED GRADUAL RETREAT OF WEST
ATLANTIC HIGH PRESSURE RIDGE AXIS WILL LEAD TO A SLOW VEERING
THROUGH THE PERIOD. WIND SPEEDS WILL REMAIN LIGHT...GENERALLY 10 KTS
OR LESS. THERE WILL LIKELY NOT BE MUCH CHANGE IN THE SEAS ALTHOUGH
THE BREAKING DOWN OF THE FETCH MAY DECREASE THE SWELL ENERGY. THIS
WILL BE SLIGHT HOWEVER AND MAY ONLY MANIFEST AS A SMALL DECREASE IN
WAVE PERIOD RATHER THAN PREDOMINANT WAVE HEIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...MRR/8
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1253 PM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 1244 PM CDT THU MAY 28 2015
THE FORECAST FOR THE AFTERNOON REMAINS ON TRACK WITH ISOLATED
CONVECTION BEGINNING TO INITIATE ALONG A WEAK SURFACE TROUGH
ACROSS SOUTH CENTRAL NORTH DAKOTA AND A MORE DISTINCT PRE-FRONTAL
TROUGH ACROSS NORTHWEST NORTH DAKOTA. EXPECT CONVECTIVE COVERAGE
TO CONTINUE TO INCREASE IN ASSOCIATION WITH THESE FEATURES AIDED
BY MULTIPLE IMPULSES EJECTING OUT OF THE UPPER LEVEL LOW ACROSS
NORTHERN WYOMING AND SOUTH CENTRAL MONTANA. SPC CONTINUES TO
MAINTAIN A MARGINAL RISK WITH THEIR 1630Z DAY ONE CONVECTIVE
OUTLOOK. THIS IS PLAUSIBLE WITH A FEW STRONG TO SEVERE STORMS
POSSIBLE...ESPECIALLY ACROSS FAR SOUTH CENTRAL NORTH DAKOTA...THE
JAMES RIVER VALLEY AND INTO EASTERN NORTH DAKOTA WITH ML CAPE OF
AROUND 1500 J/KG. HOWEVER...OVERALL DEEP LAYER SHEAR IS
MARGINAL...ON THE ORDER OF 20-30 KTS.
UPDATE ISSUED AT 859 AM CDT THU MAY 28 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE OTHER THAN TO
BLEND TO OBSERVED TRENDS THROUGH 14 UTC. EXPECT A LULL IN
CONVECTIVE ACTIVITY FOR THE NEXT COUPLE HOURS...UNTIL THE ARRIVAL
OF IMPULSES PROPAGATING NORTHEAST OUT OF WYOMING AND WESTERN SOUTH
DAKOTA AND POTENTIAL WEAK SCATTERED CONVECTION ACROSS THE
SOUTHWEST AND SOUTH CENTRAL AROUND 16-17 UTC.
UPDATE
ISSUED AT 638 AM CDT THU MAY 28 2015
SHOWERS CONTINUE TO PUSH EAST OUT OF MY EASTERN COUNTIES...SO
TWEAKED POPS TO MATCH. NEW SHOWER ACTIVITY ACROSS MY SOUTH
CENTRAL...FOLLOWED THE HRRR AND INCREASED POPS THERE FOR THIS.
ENOUGH INSTABILITY PRESENT TO INCLUDE ISOLD THUNDER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT THU MAY 28 2015
THUNDERSTORMS WILL ONCE AGAIN BE THE FOCUS FOR THE SHORT TERM.
EARLY THIS MORNING A PREFRONTAL TROUGH WAS PARKED ACROSS WESTERN
NORTH DAKOTA...WHILE A STATIONARY FRONT WAS DRAPED ACROSS
NORTHERN NORTH DAKOTA. LIGHT SHOWERS CONTINUE TO PUSH OFF TO THE
NORTH AND EAST. REDEVELOPMENT OF SHOWERS IS EXPECTED ALONG THE
FRONT THROUGH THE DAY. ACROSS WESTERN NORTH DAKOTA...WHERE SKIES
HAVE CLEARED OUT...FOG HAS DEVELOPED. THE HRRR IS SHOWING FOG
ACROSS WESTERN NORTH DAKOTA THROUGH THE EARLY MORNING HOURS.
LATER THIS AFTERNOON...THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS SOUTH CENTRAL AND SOUTHEASTERN NORTH DAKOTA ALONG THE
TROUGH AXIS. THE WRF/RAP/HRRR ARE SHOWING A RAPIDLY DESTABILIZING
BOUNDARY LAYER THIS AFTERNOON WITH 1000+ J/KG CAPE AND STEEP LOW
LEVEL LAPSE RATES. AGAIN THE INGREDIENT THAT APPEARS TO BE LACKING
IS SHEAR. HOWEVER...STRONG STORMS ARE POSSIBLE WITH GUSTY
WINDS...HAIL AND VERY HEAVY RAIN.
AS WE HEAD TOWARD THE LATE AFTERNOON AND EVENING HOURS...AN UPPER
LEVEL SHORTWAVE TROUGH WILL ENTER THE WESTERN DAKOTAS. THIS WILL
PROVIDE THE FORCING NEEDED TO KICK THE STATIONARY FRONT SOUTHWARD
ACROSS NORTH NORTH DAKOTA AS A COLD FRONT. WIDESPREAD SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT LATE THIS
AFTERNOON AND EVENING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM CDT THU MAY 28 2015
A DRY AND COOL FRI-SAT AFTERNOON PERIOD FOLLOWED BY A MUCH MORE
ACTIVE WEATHER PATTERN SATURDAY NIGHT AND ONWARDS ARE THE MAIN
HIGHLIGHTS IN THE LONG TERM PERIOD.
A STABLE AIRMASS ASSOCIATED WITH A RIDGE OF SURFACE HIGH PRESSURE
WILL DEVELOP ACROSS THE NORTHERN PLAINS ON FRIDAY...REMAINING IN
PLACE THROUGH MUCH OF SATURDAY. HIGHS FRI-SAT COMFORTABLE AT
55-65. DRY AIR ACCOMPANYING THE SFC HIGH WILL BRING A CHANCE FOR
WIDESPREAD FROST FRIDAY NIGHT-SAT MORNING WITH FORECAST LOWS IN
THE 30S. WOULD EXPECT SOME SORT OF FROST HEADLINES BEING ISSUED
FOR THAT PERIOD OVER THE NEXT 24-36 HOURS.
ROBUST RETURN FLOW WEST SATURDAY AND AREA WIDE SUNDAY INTO EARLY
NEXT WEEK AS THE RIDGE OF HIGH PRESSURE MOVES OFF TO OUR EAST AND
A STRONG FRONTAL BOUNDARY DEVELOPS JUST OFF TO OUR WEST ACROSS THE
HIGH PLAINS. FIRST WAVE OF PRECIPITATION ARRIVES SATURDAY NIGHT AS
A STRONG MID LEVEL S/WV IMPULSE MOVES EAST IN ZONAL FLOW TOWARDS
AND ACROSS NORTH DAKOTA. BOTH GFS/EC SHOW LITTLE IF ANY
INSTABILITY SO REMOVED THUNDER AND WENT WITH STRAIGHT SHOWERS.
THIS AREA OF SHOWERS CONTINUES SUNDAY MORNING BEFORE MOVING OFF TO
OUR EAST BY SUNDAY AFTERNOON. SPOTTY POPS FOR THE REMAINDER OF
SUNDAY AND SUNDAY NIGHT ALONG WITH A SLIGHT CHANCE FOR T-STORMS.
WE WILL WARM BACK INTO THE 70S WEST AND SOUTH CENTRAL WHERE MODELS
PUT THE STRONGER WAA.
STRONG WARM AIR AND MOISTURE ADVECTION CONTINUES EARLY NEXT WEEK
WITH HIGH TEMPERATURES WARMING INTO THE 70S TO MID 80S ACROSS THE
REGION. THIS WILL RESULT IN INCREASING INSTABILITY MONDAY INTO
THE MIDDLE PORTIONS OF THE WEEK. 12Z GFS/EC MODELS STILL PROJECT
ANYWHERE FROM 1500-3500 J/KG OF MUCAPE ALONG WITH AMPLE WIND SHEAR
FOR THE MONDAY-WEDNESDAY TIMEFRAME. STILL LOTS OF UNCERTAINTY
WHERE THE BEST COMBINATION OF FORCING...INSTABILITY...AND SHEAR
WILL SET UP. WILL MENTION THE POSSIBILITY FOR STRONG THUNDERSTORMS
AND HEAVY RAINFALL IN THE HWO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1244 PM CDT THU MAY 28 2015
SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THIS AFTERNOON AND INTO THE EARLY EVENING. A COLD
FRONT WILL OVERTAKE THE AREA FROM NORTHWEST TO SOUTHEAST LATE THIS
AFTERNOON AND THROUGH THE EVENING. MVFR/IFR STRATUS IS FORECAST
BEHIND THE FRONT TONIGHT INTO FRIDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AJ
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1237 PM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 1230 PM CDT THU MAY 28 2015
MINIMAL CHANGES THIS UPDATE PERIOD. WEAKENING ECHOES CONTINUE TO
PROPAGATE E-NE ACROSS THE FAR EASTERN FA AND MADE MINOR POP
ADJUSTMENTS THIS AREA. OTHERWISE...SURFACE LOW ALONG N CENTRAL
ND/CANADIAN BORDER TO CONTINUE TO PROPAGATE NE THIS AFTERNOON. E-W
ORIENTED SURFACE WARM FRONT FROM THE LOW ACROSS THE NORTHERN
FA SHOULD ALSO LIFT NORTH INTO S CANADA. N-S PREFRONTAL TROUGH
FROM THE LOW THROUGH THE CENTRAL DAKOTAS SHOULD BE OVERTAKEN BY
APPROACHING COLD FRONT FROM N CENTRAL INTO SW ND BY LATE
AFTERNOON. THIS BOUNDARY SHOULD BE THE PRIMARY CONVECTIVE FOCUS
LATER THIS AFTERNOON AND EVENING. NSSL WRF HIGH RESOLUTION MODEL
SEEMS TO HAVE THE BEST HANDLE ON CURRENT SITUATION AND WILL FOLLOW
IN THE NEAR TERM. NSSL WRF SHOWS RATHER UNORGANIZED DEVELOPMENT
MID AFTERNOON AND WITH SOME RECOVERY IN INSTABILITY/CAPE WILL
MAINTAIN CHC POPS REMAINDER OF THE AFTERNOON BEFORE MAIN BAND
ORGANIZES AHEAD OF COLD FRONT LATE AFTERNOON/EARLY EVENING.
UPDATE ISSUED AT 936 AM CDT THU MAY 28 2015
SHOWERS AND ISOLATED THUNDER CONTINUE TO LIFT NE WITH MAIN BAND
OVER NE FORECAST AREA. FARTHER SW CELLS MORE ISOLATED. AS WAVE
LIFTS INTO CANADA WILL SEE A BREAK BEHIND THE RAIN UNTIL PROBABLY
LATER THIS AFTERNOON. ADJUSTED POPS ACCORDINGLY REMAINDER OF THE
MORNING AND WILL ADJUST AT FURTHER UPDATES. NO OTHER CHANGES.
UPDATE ISSUED AT 701 AM CDT THU MAY 28 2015
FCST ON TRACK WITH AREA OF SHOWERS MOVING THRU THE RRV INTO
MINNESOTA. ISOLD TSTM IN FARGO AREA SO ADDED ISOLD T TO GRID IN
SRN RRV FOR NEXT COUPLE HOURS. OVERALL 06Z NCEP MODELS AND
HRRR/RAP INDICATE ABOUT THE SAME SCENARIO AS EXPECTED WITH THIS
BATCH OF PRECIP EXITING AND THEN SOME REDEVELOPMENT AHEAD OF COLD
FRONT MID AFTN. EXACTLY WHERE IS IN QUESTION. HRRR HAS BEEN A BIT
FARTHER SOUTH THAN SOME OTHER MODELS WITH MORE FARGO VS GRAND
FORKS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 336 AM CDT THU MAY 28 2015
WATER VAPOR SHOWS SHORT WAVE IN CNTRL ND EARLY THIS MORNING WITH A
WEAK SFC LOW IN WCNTRL ND. UPPER WAVE AND SFC LOW WILL MOVE
NORTHEAST TODAY. SFC LOW WILL STRENGTHEN SOME AS IT MOVES INTO
SOUTHEASTERN MANITOBA THIS AFTERNOON. A COLD FRONT SOUTHWEST FROM
THE SFC LOW WILL BE NR A HALLOCK MN-MICHIGAN ND-JAMESTOWN LINE NR
21Z. SOME HEATING WILL OCCUR AHD OF THIS FRONT TODAY WITH HIGHS UP
NEAR 80. GFS HAS A BIT MORE BULK SHEAR THAN NAM...AND WITH DEW PTS
PROGGED BY GFS IN THE LOW 60S MUCAPE IN THE 2000-2200 J/KG RANGE
IS POSSIBLE 21Z-00Z PERIOD IN A CORRIDOR ABOUT 50 MILES AHEAD OF
FRONT. MORNING SHOWERS WILL GRADUALLY LIFT NORTHEAST EARLY THIS
MORNING. THEN REDEVELOPMENT OF T-STORMS IN THE UNSTABLE CORRIDOR
FROM FAR NW MN INTO ECNTRL ND. THE STORMS WILL THEN MOVE
SOUTHEAST. IF WE INDEED GET SFC HEATING TO NR 80 AND DEW PTS
60-62...THEN I AGREE WITH SPC IN THAT ISOLD SVR STORMS ARE
POSSIBLE. NSSL WRF/SPC WRF ARE ALL A TAD SLOWER THAN HRRR/RAP.
T-STORM THREAT WILL LAST A BIT LONGER THAN EARLIER THOUGHT AND ONL
SLOWLY EXIT FAR SE ND/WCNTRL MN TONIGHT. CLEARING AND COOLER AIR
TO WORK INTO DVL BASIN BY 12Z FRI.
FRIDAY WILL BE BREEZY AND MUCH COOLER AS HIGH PRESSURE BUILDS
SOUTH.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 28 2015
FOR FRIDAY NIGHT LIGHTEST WINDS IN NORTH CENTRAL ND-DVL BASIN.
STILL IDEA PRESENT OF SOME SCT FROST DVL BASIN-LANGDON-COOPERSTOWN
AREA NEAR DAWN SATURDAY WITH LOWS 32-34 DEGREES. SATURDAY WILL SEE
SUNSHINE BUT STILL COOL WITH HIGHS AROUND 60. INCREASING HIGH
CLOUDS SAT AFTN-NIGHT AHD OF NEXT SHORT WAVE.
FOR SUNDAY THROUGH WEDNESDAY...
HIGH AMPLITUDE LONG WAVE RIDGE TROUGH WAS LOCATED OVER NORTHERN
NORTH AMERICA. LONG WAVE PATTERN DE-AMPLIFIES A BIT OVER NORTHERN
CANADA THROUGH THE PERIOD. A MORE ZONAL FLOW IS ACROSS THE STATES
THROUGH THE PERIOD.
THE ECMWF AND GFS WERE IN GOOD AGREEMENT AT 84 HOURS. HOWEVER THE
GFS BECOMES FASTER SOLUTION THAN THE ECMWF BY THE END OF THE PERIOD.
BOTH THE GFS AND THE ECMWF WERE SLOWER AND FARTHER NORTH OVER THE
LAST COUPLE RUNS. WILL PREFER THE ECMWF.
LITTLE CHANGE TO HIGH TEMPS ON SUN. TEMPS INCREASED A DEGREE OR TWO
FOR MON AND DECREASED ONE TO THREE DEGREES FOR TUE AND WED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1230 PM CDT THU MAY 28 2015
VFR CONDITIONS WILL CONTINUE... BUT SCATTERED SHOWERS AND
THUNDERSTORMS SHOULD BEGIN TO REDEVELOP DURING THE 20 TO 23Z TIME
FRAME. KEPT MENTION AS VCTS AS IT IS UNCERTAIN IF A STORM WILL
IMPACT INDIVIDUAL TAF SITES AT THIS TIME. WINDS WILL SHIFT AROUND TO
THE SOUTHWEST AS LOW PRESSURE MOVES INTO THE AREA. THINK THERE WILL
BE A BRIEF BREAK IN PRECIP ACTIVITY THIS EVENING AS THE FIRST ROUND
OF THUNDERSTORMS MOVES IN AND THE NEXT ARRIVES WITH THE MAIN COLD
FRONT LATER TONIGHT. HAVE THE FRONTAL BOUNDARY COMING THROUGH DURING
THE 04 TO 09Z TIME WITH WINDS SHIFTING TO THE NORTH AND SOME SHOWER
ACTIVITY. SOME MVFR CIGS ARE POSSIBLE BEHIND THE COLD FRONT LATER IN
THE PERIOD WITH GUSTY NORTH WINDS OVER 25 KTS. KEPT CIGS IN THE 2500-
3500 FT RANGE FOR TOMORROW MORNING BUT WILL HAVE TO WATCH IF
ANYTHING LOWER FORMS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...RIDDLE
LONG TERM...HOPPES/RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
941 AM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 936 AM CDT THU MAY 28 2015
SHOWERS AND ISOLATED THUNDER CONTINUE TO LIFT NE WITH MAIN BAND
OVER NE FORECAST AREA. FARTHER SW CELLS MORE ISOLATED. AS WAVE
LIFTS INTO CANADA WILL SEE A BREAK BEHIND THE RAIN UNTIL PROBABLY
LATER THIS AFTERNOON. ADJUSTED POPS ACCORDINGLY REMAINDER OF THE
MORNING AND WILL ADJUST AT FURTHER UPDATES. NO OTHER CHANGES.
UPDATE ISSUED AT 701 AM CDT THU MAY 28 2015
FCST ON TRACK WITH AREA OF SHOWERS MOVING THRU THE RRV INTO
MINNESOTA. ISOLD TSTM IN FARGO AREA SO ADDED ISOLD T TO GRID IN
SRN RRV FOR NEXT COUPLE HOURS. OVERALL 06Z NCEP MODELS AND
HRRR/RAP INDICATE ABOUT THE SAME SCENARIO AS EXPECTED WITH THIS
BATCH OF PRECIP EXITING AND THEN SOME REDEVELOPMENT AHEAD OF COLD
FRONT MID AFTN. EXACTLY WHERE IS IN QUESTION. HRRR HAS BEEN A BIT
FARTHER SOUTH THAN SOME OTHER MODELS WITH MORE FARGO VS GRAND
FORKS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 336 AM CDT THU MAY 28 2015
WATER VAPOR SHOWS SHORT WAVE IN CNTRL ND EARLY THIS MORNING WITH A
WEAK SFC LOW IN WCNTRL ND. UPPER WAVE AND SFC LOW WILL MOVE
NORTHEAST TODAY. SFC LOW WILL STRENGTHEN SOME AS IT MOVES INTO
SOUTHEASTERN MANITOBA THIS AFTERNOON. A COLD FRONT SOUTHWEST FROM
THE SFC LOW WILL BE NR A HALLOCK MN-MICHIGAN ND-JAMESTOWN LINE NR
21Z. SOME HEATING WILL OCCUR AHD OF THIS FRONT TODAY WITH HIGHS UP
NEAR 80. GFS HAS A BIT MORE BULK SHEAR THAN NAM...AND WITH DEW PTS
PROGGED BY GFS IN THE LOW 60S MUCAPE IN THE 2000-2200 J/KG RANGE
IS POSSIBLE 21Z-00Z PERIOD IN A CORRIDOR ABOUT 50 MILES AHEAD OF
FRONT. MORNING SHOWERS WILL GRADUALLY LIFT NORTHEAST EARLY THIS
MORNING. THEN REDEVELOPMENT OF T-STORMS IN THE UNSTABLE CORRIDOR
FROM FAR NW MN INTO ECNTRL ND. THE STORMS WILL THEN MOVE
SOUTHEAST. IF WE INDEED GET SFC HEATING TO NR 80 AND DEW PTS
60-62...THEN I AGREE WITH SPC IN THAT ISOLD SVR STORMS ARE
POSSIBLE. NSSL WRF/SPC WRF ARE ALL A TAD SLOWER THAN HRRR/RAP.
T-STORM THREAT WILL LAST A BIT LONGER THAN EARLIER THOUGHT AND ONL
SLOWLY EXIT FAR SE ND/WCNTRL MN TONIGHT. CLEARING AND COOLER AIR
TO WORK INTO DVL BASIN BY 12Z FRI.
FRIDAY WILL BE BREEZY AND MUCH COOLER AS HIGH PRESSURE BUILDS
SOUTH.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 28 2015
FOR FRIDAY NIGHT LIGHTEST WINDS IN NORTH CENTRAL ND-DVL BASIN.
STILL IDEA PRESENT OF SOME SCT FROST DVL BASIN-LANGDON-COOPERSTOWN
AREA NEAR DAWN SATURDAY WITH LOWS 32-34 DEGREES. SATURDAY WILL SEE
SUNSHINE BUT STILL COOL WITH HIGHS AROUND 60. INCREASING HIGH
CLOUDS SAT AFTN-NIGHT AHD OF NEXT SHORT WAVE.
FOR SUNDAY THROUGH WEDNESDAY...
HIGH AMPLITUDE LONG WAVE RIDGE TROUGH WAS LOCATED OVER NORTHERN
NORTH AMERICA. LONG WAVE PATTERN DE-AMPLIFIES A BIT OVER NORTHERN
CANADA THROUGH THE PERIOD. A MORE ZONAL FLOW IS ACROSS THE STATES
THROUGH THE PERIOD.
THE ECMWF AND GFS WERE IN GOOD AGREEMENT AT 84 HOURS. HOWEVER THE
GFS BECOMES FASTER SOLUTION THAN THE ECMWF BY THE END OF THE PERIOD.
BOTH THE GFS AND THE ECMWF WERE SLOWER AND FARTHER NORTH OVER THE
LAST COUPLE RUNS. WILL PREFER THE ECMWF.
LITTLE CHANGE TO HIGH TEMPS ON SUN. TEMPS INCREASED A DEGREE OR TWO
FOR MON AND DECREASED ONE TO THREE DEGREES FOR TUE AND WED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 701 AM CDT THU MAY 28 2015
ISOLD THUNDERSTORM NEAR FARGO WILL EXIT BY 13Z. OTHERWISE EXITING
THE NRN VALLEY AND NW MN THIS MORNING. A BREAK EXPECTED...WITH VFR
CIGS (HIGH BASED CU AND AC). THEN QUESTION IS TSTM DEVELOPMENT
AHEAD OF FRONT AND LOCATION. KEPT VCTS IDEA IN MOST TAFS MID TO
LATE AFTN. AFTER EARLY THIS MORNING WINDS WILL BE SOUTHEAST 10 TO
25 KTS THEN TURNING WEST AND NORTH-NORTHWEST BEHIND THE FRONT
TONIGHT. SOME RISK OF BRIEF MVFR CIGS BEHIND FRONT BUT KEPT IN VFR
CAT FOR NOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...RIDDLE
LONG TERM...HOPPES/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
903 AM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 859 AM CDT THU MAY 28 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE OTHER THAN TO
BLEND TO OBSERVED TRENDS THROUGH 14 UTC. EXPECT A LULL IN
CONVECTIVE ACTIVITY FOR THE NEXT COUPLE HOURS...UNTIL THE ARRIVAL
OF IMPULSES PROPAGATING NORTHEAST OUT OF WYOMING AND WESTERN SOUTH
DAKOTA AND POTENTIAL WEAK SCATTERED CONVECTION ACROSS THE
SOUTHWEST AND SOUTH CENTRAL AROUND 16-17 UTC.
UPDATE
ISSUED AT 638 AM CDT THU MAY 28 2015
SHOWERS CONTINUE TO PUSH EAST OUT OF MY EASTERN COUNTIES...SO
TWEAKED POPS TO MATCH. NEW SHOWER ACTIVITY ACROSS MY SOUTH
CENTRAL...FOLLOWED THE HRRR AND INCREASED POPS THERE FOR THIS.
ENOUGH INSTABILITY PRESENT TO INCLUDE ISOLD THUNDER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT THU MAY 28 2015
THUNDERSTORMS WILL ONCE AGAIN BE THE FOCUS FOR THE SHORT TERM.
EARLY THIS MORNING A PREFRONTAL TROUGH WAS PARKED ACROSS WESTERN
NORTH DAKOTA...WHILE A STATIONARY FRONT WAS DRAPED ACROSS
NORTHERN NORTH DAKOTA. LIGHT SHOWERS CONTINUE TO PUSH OFF TO THE
NORTH AND EAST. REDEVELOPMENT OF SHOWERS IS EXPECTED ALONG THE
FRONT THROUGH THE DAY. ACROSS WESTERN NORTH DAKOTA...WHERE SKIES
HAVE CLEARED OUT...FOG HAS DEVELOPED. THE HRRR IS SHOWING FOG
ACROSS WESTERN NORTH DAKOTA THROUGH THE EARLY MORNING HOURS.
LATER THIS AFTERNOON...THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS SOUTH CENTRAL AND SOUTHEASTERN NORTH DAKOTA ALONG THE
TROUGH AXIS. THE WRF/RAP/HRRR ARE SHOWING A RAPIDLY DESTABILIZING
BOUNDARY LAYER THIS AFTERNOON WITH 1000+ J/KG CAPE AND STEEP LOW
LEVEL LAPSE RATES. AGAIN THE INGREDIENT THAT APPEARS TO BE LACKING
IS SHEAR. HOWEVER...STRONG STORMS ARE POSSIBLE WITH GUSTY
WINDS...HAIL AND VERY HEAVY RAIN.
AS WE HEAD TOWARD THE LATE AFTERNOON AND EVENING HOURS...AN UPPER
LEVEL SHORTWAVE TROUGH WILL ENTER THE WESTERN DAKOTAS. THIS WILL
PROVIDE THE FORCING NEEDED TO KICK THE STATIONARY FRONT SOUTHWARD
ACROSS NORTH NORTH DAKOTA AS A COLD FRONT. WIDESPREAD SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT LATE THIS
AFTERNOON AND EVENING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM CDT THU MAY 28 2015
A DRY AND COOL FRI-SAT AFTERNOON PERIOD FOLLOWED BY A MUCH MORE
ACTIVE WEATHER PATTERN SATURDAY NIGHT AND ONWARDS ARE THE MAIN
HIGHLIGHTS IN THE LONG TERM PERIOD.
A STABLE AIRMASS ASSOCIATED WITH A RIDGE OF SURFACE HIGH PRESSURE
WILL DEVELOP ACROSS THE NORTHERN PLAINS ON FRIDAY...REMAINING IN
PLACE THROUGH MUCH OF SATURDAY. HIGHS FRI-SAT COMFORTABLE AT
55-65. DRY AIR ACCOMPANYING THE SFC HIGH WILL BRING A CHANCE FOR
WIDESPREAD FROST FRIDAY NIGHT-SAT MORNING WITH FORECAST LOWS IN
THE 30S. WOULD EXPECT SOME SORT OF FROST HEADLINES BEING ISSUED
FOR THAT PERIOD OVER THE NEXT 24-36 HOURS.
ROBUST RETURN FLOW WEST SATURDAY AND AREA WIDE SUNDAY INTO EARLY
NEXT WEEK AS THE RIDGE OF HIGH PRESSURE MOVES OFF TO OUR EAST AND
A STRONG FRONTAL BOUNDARY DEVELOPS JUST OFF TO OUR WEST ACROSS THE
HIGH PLAINS. FIRST WAVE OF PRECIPITATION ARRIVES SATURDAY NIGHT AS
A STRONG MID LEVEL S/WV IMPULSE MOVES EAST IN ZONAL FLOW TOWARDS
AND ACROSS NORTH DAKOTA. BOTH GFS/EC SHOW LITTLE IF ANY
INSTABILITY SO REMOVED THUNDER AND WENT WITH STRAIGHT SHOWERS.
THIS AREA OF SHOWERS CONTINUES SUNDAY MORNING BEFORE MOVING OFF TO
OUR EAST BY SUNDAY AFTERNOON. SPOTTY POPS FOR THE REMAINDER OF
SUNDAY AND SUNDAY NIGHT ALONG WITH A SLIGHT CHANCE FOR T-STORMS.
WE WILL WARM BACK INTO THE 70S WEST AND SOUTH CENTRAL WHERE MODELS
PUT THE STRONGER WAA.
STRONG WARM AIR AND MOISTURE ADVECTION CONTINUES EARLY NEXT WEEK
WITH HIGH TEMPERATURES WARMING INTO THE 70S TO MID 80S ACROSS THE
REGION. THIS WILL RESULT IN INCREASING INSTABILITY MONDAY INTO
THE MIDDLE PORTIONS OF THE WEEK. 12Z GFS/EC MODELS STILL PROJECT
ANYWHERE FROM 1500-3500 J/KG OF MUCAPE ALONG WITH AMPLE WIND SHEAR
FOR THE MONDAY-WEDNESDAY TIMEFRAME. STILL LOTS OF UNCERTAINTY
WHERE THE BEST COMBINATION OF FORCING...INSTABILITY...AND SHEAR
WILL SET UP. WILL MENTION THE POSSIBILITY FOR STRONG THUNDERSTORMS
AND HEAVY RAINFALL IN THE HWO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 859 AM CDT THU MAY 28 2015
IFR AND BELOW CONDITIONS IN FOG AND LOW STRATUS WILL TRANSITION
TO VFR LATER THIS MORNING ACROSS NORTHERN AND WESTERN NORTH
DAKOTA. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS
SOUTHERN AND EASTERN NORTH DAKOTA THIS AFTERNOON. KJMS MAY SEE
SOME THUNDERSTORMS BEGINNING AROUND 19-21Z. MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS...AND MVFR CONDITIONS...ARE POSSIBLE
LATER THIS AFTERNOON AND EVENING AT ALL TAF SITES AS A COLD FRONT
MOVES FROM NORTH TO SOUTH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AJ
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
705 AM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 701 AM CDT THU MAY 28 2015
FCST ON TRACK WITH AREA OF SHOWERS MOVING THRU THE RRV INTO
MINNESOTA. ISOLD TSTM IN FARGO AREA SO ADDED ISOLD T TO GRID IN
SRN RRV FOR NEXT COUPLE HOURS. OVERALL 06Z NCEP MODELS AND
HRRR/RAP INDICATE ABOUT THE SAME SCENARIO AS EXPECTED WITH THIS
BATCH OF PRECIP EXITING AND THEN SOME REDEVELOPMENT AHEAD OF COLD
FRONT MID AFTN. EXACTLY WHERE IS IN QUESTION. HRRR HAS BEEN A BIT
FARTHER SOUTH THAN SOME OTHER MODELS WITH MORE FARGO VS GRAND
FORKS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 336 AM CDT THU MAY 28 2015
WATER VAPOR SHOWS SHORT WAVE IN CNTRL ND EARLY THIS MORNING WITH A
WEAK SFC LOW IN WCNTRL ND. UPPER WAVE AND SFC LOW WILL MOVE
NORTHEAST TODAY. SFC LOW WILL STRENGHTEN SOME AS IT MOVES INTO
SOUTHEASTERN MANITOBA THIS AFTERNOON. A COLD FRONT SOUTHWEST FROM
THE SFC LOW WILL BE NR A HALLOCK MN-MICHIGAN ND-JAMESTOWN LINE NR
21Z. SOME HEATING WILL OCCUR AHD OF THIS FRONT TODAY WITH HIGHS UP
NEAR 80. GFS HAS A BIT MORE BULK SHEAR THAN NAM...AND WITH DEW PTS
PROGGED BY GFS IN THE LOW 60S MUCAPE IN THE 2000-2200 J/KG RANGE
IS POSSIBLE 21Z-00Z PERIOD IN A CORRIDOR ABOUT 50 MILES AHEAD OF
FRONT. MORNING SHOWERS WILL GRADUALLY LIFT NORTHEAST EARLY THIS
MORNING. THEN REDEVELOPMENT OF T-STORMS IN THE UNSTABLE CORRIDOR
FROM FAR NW MN INTO ECNTRL ND. THE STORMS WILL THEN MOVE
SOUTHEAST. IF WE INDEED GET SFC HEATING TO NR 80 AND DEW PTS
60-62...THEN I AGREE WITH SPC IN THAT ISOLD SVR STORMS ARE
POSSIBLE. NSSL WRF/SPC WRF ARE ALL A TAD SLOWER THAN HRRR/RAP.
T-STORM THREAT WILL LAST A BIT LONGER THAN EARLIER THOUGHT AND ONL
SLOWLY EXIT FAR SE ND/WCNTRL MN TONIGHT. CLEARING AND COOLER AIR
TO WORK INTO DVL BASIN BY 12Z FRI.
FRIDAY WILL BE BREEZY AND MUCH COOLER AS HIGH PRESSURE BUILDS
SOUTH.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 28 2015
FOR FRIDAY NIGHT LIGHTEST WINDS IN NORTH CENTRAL ND-DVL BASIN.
STILL IDEA PRESENT OF SOME SCT FROST DVL BASIN-LANGDON-COOPERSTOWN
AREA NEAR DAWN SATURDAY WITH LOWS 32-34 DEGREES. SATURDAY WILL SEE
SUNSHINE BUT STILL COOL WITH HIGHS AROUND 60. INCREASING HIGH
CLOUDS SAT AFTN-NIGHT AHD OF NEXT SHORT WAVE.
FOR SUNDAY THROUGH WEDNESDAY...
HIGH AMPLITUDE LONG WAVE RIDGE TROUGH WAS LOCATED OVER NORTHERN
NORTH AMERICA. LONG WAVE PATTERN DE-AMPLIFIES A BIT OVER NORTHERN
CANADA THROUGH THE PERIOD. A MORE ZONAL FLOW IS ACROSS THE STATES
THROUGH THE PERIOD.
THE ECMWF AND GFS WERE IN GOOD AGREEMENT AT 84 HOURS. HOWEVER THE
GFS BECOMES FASTER SOLUTION THAN THE ECMWF BY THE END OF THE PERIOD.
BOTH THE GFS AND THE ECMWF WERE SLOWER AND FARTHER NORTH OVER THE
LAST COUPLE RUNS. WILL PREFER THE ECMWF.
LITTLE CHANGE TO HIGH TEMPS ON SUN. TEMPS INCREASED A DEGREE OR TWO
FOR MON AND DECREASED ONE TO THREE DEGREES FOR TUE AND WED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 701 AM CDT THU MAY 28 2015
ISOLD THUNDERSTORM NEAR FARGO WILL EXIT BY 13Z. OTHERWISE EXITING
THE NRN VALLEY AND NW MN THIS MORNING. A BREAK EXPECTED...WITH VFR
CIGS (HIGH BASED CU AND AC). THEN QUESTION IS TSTM DEVELOPMENT
AHEAD OF FRONT AND LOCATION. KEPT VCTS IDEA IN MOST TAFS MID TO
LATE AFTN. AFTER EARLY THIS MORNING WINDS WILL BE SOUTHEAST 10 TO
25 KTS THEN TURNING WEST AND NORTH-NORTHWEST BEHIND THE FRONT
TONIGHT. SOME RISK OF BRIEF MVFR CIGS BEHIND FRONT BUT KEPT IN VFR
CAT FOR NOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...RIDDLE
LONG TERM...HOPPES/RIDDLE
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 AM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 638 AM CDT THU MAY 28 2015
SHOWERS CONTINUE TO PUSH EAST OUT OF MY EASTERN COUNTIES...SO
TWEAKED POPS TO MATCH. NEW SHOWER ACTIVITY ACROSS MY SOUTH
CENTRAL...FOLLOWED THE HRRR AND INCREASED POPS THERE FOR THIS.
ENOUGH INSTABILITY PRESENT TO INCLUDE ISOLD THUNDER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT THU MAY 28 2015
THUNDERSTORMS WILL ONCE AGAIN BE THE FOCUS FOR THE SHORT TERM.
EARLY THIS MORNING A PREFRONTAL TROUGH WAS PARKED ACROSS WESTERN
NORTH DAKOTA...WHILE A STATIONARY FRONT WAS DRAPED ACROSS
NORTHERN NORTH DAKOTA. LIGHT SHOWERS CONTINUE TO PUSH OFF TO THE
NORTH AND EAST. REDEVELOPMENT OF SHOWERS IS EXPECTED ALONG THE
FRONT THROUGH THE DAY. ACROSS WESTERN NORTH DAKOTA...WHERE SKIES
HAVE CLEARED OUT...FOG HAS DEVELOPED. THE HRRR IS SHOWING FOG
ACROSS WESTERN NORTH DAKOTA THROUGH THE EARLY MORNING HOURS.
LATER THIS AFTERNOON...THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS SOUTH CENTRAL AND SOUTHEASTERN NORTH DAKOTA ALONG THE
TROUGH AXIS. THE WRF/RAP/HRRR ARE SHOWING A RAPIDLY DESTABILIZING
BOUNDARY LAYER THIS AFTERNOON WITH 1000+ J/KG CAPE AND STEEP LOW
LEVEL LAPSE RATES. AGAIN THE INGREDIENT THAT APPEARS TO BE LACKING
IS SHEAR. HOWEVER...STRONG STORMS ARE POSSIBLE WITH GUSTY
WINDS...HAIL AND VERY HEAVY RAIN.
AS WE HEAD TOWARD THE LATE AFTERNOON AND EVENING HOURS...AN UPPER
LEVEL SHORTWAVE TROUGH WILL ENTER THE WESTERN DAKOTAS. THIS WILL
PROVIDE THE FORCING NEEDED TO KICK THE STATIONARY FRONT SOUTHWARD
ACROSS NORTH NORTH DAKOTA AS A COLD FRONT. WIDESPREAD SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT LATE THIS
AFTERNOON AND EVENING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM CDT THU MAY 28 2015
A DRY AND COOL FRI-SAT AFTERNOON PERIOD FOLLOWED BY A MUCH MORE
ACTIVE WEATHER PATTERN SATURDAY NIGHT AND ONWARDS ARE THE MAIN
HIGHLIGHTS IN THE LONG TERM PERIOD.
A STABLE AIRMASS ASSOCIATED WITH A RIDGE OF SURFACE HIGH PRESSURE
WILL DEVELOP ACROSS THE NORTHERN PLAINS ON FRIDAY...REMAINING IN
PLACE THROUGH MUCH OF SATURDAY. HIGHS FRI-SAT COMFORTABLE AT
55-65. DRY AIR ACCOMPANYING THE SFC HIGH WILL BRING A CHANCE FOR
WIDESPREAD FROST FRIDAY NIGHT-SAT MORNING WITH FORECAST LOWS IN
THE 30S. WOULD EXPECT SOME SORT OF FROST HEADLINES BEING ISSUED
FOR THAT PERIOD OVER THE NEXT 24-36 HOURS.
ROBUST RETURN FLOW WEST SATURDAY AND AREA WIDE SUNDAY INTO EARLY
NEXT WEEK AS THE RIDGE OF HIGH PRESSURE MOVES OFF TO OUR EAST AND
A STRONG FRONTAL BOUNDARY DEVELOPS JUST OFF TO OUR WEST ACROSS THE
HIGH PLAINS. FIRST WAVE OF PRECIPITATION ARRIVES SATURDAY NIGHT AS
A STRONG MID LEVEL S/WV IMPULSE MOVES EAST IN ZONAL FLOW TOWARDS
AND ACROSS NORTH DAKOTA. BOTH GFS/EC SHOW LITTLE IF ANY
INSTABILITY SO REMOVED THUNDER AND WENT WITH STRAIGHT SHOWERS.
THIS AREA OF SHOWERS CONTINUES SUNDAY MORNING BEFORE MOVING OFF TO
OUR EAST BY SUNDAY AFTERNOON. SPOTTY POPS FOR THE REMAINDER OF
SUNDAY AND SUNDAY NIGHT ALONG WITH A SLIGHT CHANCE FOR T-STORMS.
WE WILL WARM BACK INTO THE 70S WEST AND SOUTH CENTRAL WHERE MODELS
PUT THE STRONGER WAA.
STRONG WARM AIR AND MOISTURE ADVECTION CONTINUES EARLY NEXT WEEK
WITH HIGH TEMPERATURES WARMING INTO THE 70S TO MID 80S ACROSS THE
REGION. THIS WILL RESULT IN INCREASING INSTABILITY MONDAY INTO
THE MIDDLE PORTIONS OF THE WEEK. 12Z GFS/EC MODELS STILL PROJECT
ANYWHERE FROM 1500-3500 J/KG OF MUCAPE ALONG WITH AMPLE WIND SHEAR
FOR THE MONDAY-WEDNESDAY TIMEFRAME. STILL LOTS OF UNCERTAINTY
WHERE THE BEST COMBINATION OF FORCING...INSTABILITY...AND SHEAR
WILL SET UP. WILL MENTION THE POSSIBILITY FOR STRONG THUNDERSTORMS
AND HEAVY RAINFALL IN THE HWO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 638 AM CDT THU MAY 28 2015
IFR AND BELOW CONDITIONS IN FOG AND LOW STRATUS WILL TRANSITION
TO VFR LATER THIS MORNING ACROSS NORTHERN AND WESTERN NORTH
DAKOTA. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS
SOUTHERN AND EASTERN NORTH DAKOTA THIS AFTERNOON. KJMS MAY SEE
SOME THUNDERSTORMS BEGINNING AROUND 19-21Z. MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS...AND MVFR CONDITIONS...ARE POSSIBLE
LATER THIS AFTERNOON AND EVENING AT ALL TAF SITES AS A COLD FRONT
MOVES FROM NORTH TO SOUTH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...AJ
LONG TERM...NH
AVIATION...NH/AJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
415 AM CDT THU MAY 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT THU MAY 28 2015
THUNDERSTORMS WILL ONCE AGAIN BE THE FOCUS FOR THE SHORT TERM.
EARLY THIS MORNING A PREFRONTAL TROUGH WAS PARKED ACROSS WESTERN
NORTH DAKOTA...WHILE A STATIONARY FRONT WAS DRAPED ACROSS
NORTHERN NORTH DAKOTA. LIGHT SHOWERS CONTINUE TO PUSH OFF TO THE
NORTH AND EAST. REDEVELOPMENT OF SHOWERS IS EXPECTED ALONG THE
FRONT THROUGH THE DAY. ACROSS WESTERN NORTH DAKOTA...WHERE SKIES
HAVE CLEARED OUT...FOG HAS DEVELOPED. THE HRRR IS SHOWING FOG
ACROSS WESTERN NORTH DAKOTA THROUGH THE EARLY MORNING HOURS.
LATER THIS AFTERNOON...THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS SOUTH CENTRAL AND SOUTHEASTERN NORTH DAKOTA ALONG THE
TROUGH AXIS. THE WRF/RAP/HRRR ARE SHOWING A RAPIDLY DESTABILIZING
BOUNDARY LAYER THIS AFTERNOON WITH 1000+ J/KG CAPE AND STEEP LOW
LEVEL LAPSE RATES. AGAIN THE INGREDIENT THAT APPEARS TO BE LACKING
IS SHEAR. HOWEVER...STRONG STORMS ARE POSSIBLE WITH GUSTY
WINDS...HAIL AND VERY HEAVY RAIN.
AS WE HEAD TOWARD THE LATE AFTERNOON AND EVENING HOURS...AN UPPER
LEVEL SHORTWAVE TROUGH WILL ENTER THE WESTERN DAKOTAS. THIS WILL
PROVIDE THE FORCING NEEDED TO KICK THE STATIONARY FRONT SOUTHWARD
ACROSS NORTH NORTH DAKOTA AS A COLD FRONT. WIDESPREAD SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT LATE THIS
AFTERNOON AND EVENING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM CDT THU MAY 28 2015
A DRY AND COOL FRI-SAT AFTERNOON PERIOD FOLLOWED BY A MUCH MORE
ACTIVE WEATHER PATTERN SATURDAY NIGHT AND ONWARDS ARE THE MAIN
HIGHLIGHTS IN THE LONG TERM PERIOD.
A STABLE AIRMASS ASSOCIATED WITH A RIDGE OF SURFACE HIGH PRESSURE
WILL DEVELOP ACROSS THE NORTHERN PLAINS ON FRIDAY...REMAINING IN
PLACE THROUGH MUCH OF SATURDAY. HIGHS FRI-SAT COMFORTABLE AT
55-65. DRY AIR ACCOMPANYING THE SFC HIGH WILL BRING A CHANCE FOR
WIDESPREAD FROST FRIDAY NIGHT-SAT MORNING WITH FORECAST LOWS IN
THE 30S. WOULD EXPECT SOME SORT OF FROST HEADLINES BEING ISSUED
FOR THAT PERIOD OVER THE NEXT 24-36 HOURS.
ROBUST RETURN FLOW WEST SATURDAY AND AREA WIDE SUNDAY INTO EARLY
NEXT WEEK AS THE RIDGE OF HIGH PRESSURE MOVES OFF TO OUR EAST AND
A STRONG FRONTAL BOUNDARY DEVELOPS JUST OFF TO OUR WEST ACROSS THE
HIGH PLAINS. FIRST WAVE OF PRECIPITATION ARRIVES SATURDAY NIGHT AS
A STRONG MID LEVEL S/WV IMPULSE MOVES EAST IN ZONAL FLOW TOWARDS
AND ACROSS NORTH DAKOTA. BOTH GFS/EC SHOW LITTLE IF ANY
INSTABILITY SO REMOVED THUNDER AND WENT WITH STRAIGHT SHOWERS.
THIS AREA OF SHOWERS CONTINUES SUNDAY MORNING BEFORE MOVING OFF TO
OUR EAST BY SUNDAY AFTERNOON. SPOTTY POPS FOR THE REMAINDER OF
SUNDAY AND SUNDAY NIGHT ALONG WITH A SLIGHT CHANCE FOR T-STORMS.
WE WILL WARM BACK INTO THE 70S WEST AND SOUTH CENTRAL WHERE MODELS
PUT THE STRONGER WAA.
STRONG WARM AIR AND MOISTURE ADVECTION CONTINUES EARLY NEXT WEEK
WITH HIGH TEMPERATURES WARMING INTO THE 70S TO MID 80S ACROSS THE
REGION. THIS WILL RESULT IN INCREASING INSTABILITY MONDAY INTO
THE MIDDLE PORTIONS OF THE WEEK. 12Z GFS/EC MODELS STILL PROJECT
ANYWHERE FROM 1500-3500 J/KG OF MUCAPE ALONG WITH AMPLE WIND SHEAR
FOR THE MONDAY-WEDNESDAY TIMEFRAME. STILL LOTS OF UNCERTAINTY
WHERE THE BEST COMBINATION OF FORCING...INSTABILITY...AND SHEAR
WILL SET UP. WILL MENTION THE POSSIBILITY FOR STRONG THUNDERSTORMS
AND HEAVY RAINFALL IN THE HWO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1241 AM CDT THU MAY 28 2015
RAIN SHOWERS HAVE ENDED AT ALL BUT KJMS. LATEST MODELS STILL
FORECAST MVFR/IFR CONDITIONS FORMING EARLY THIS MORNING AT
KDIK/KMOT/KISN. SOME UNCERTAINTY IF THIS WILL BE IFR OF MORE
MVFR. TRENDING TO THE MORE POSITIVE MVFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...NH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1256 AM CDT THU MAY 28 2015
.UPDATE...
ISSUED AT 1241 AM CDT THU MAY 28 2015
SEVERAL CHANGES WERE MADE FOR THIS UPDATE.
FIRST...PRECIPITATION IS FALLING APART AND MOVING OFF TO THE
NORTHEAST FASTER THAN PREVIOUSLY THOUGHT. THEREFORE...LOWERED
PRECIPITATION AMOUNTS AND CHANCES FOR THE EARLY MORNING HOURS.
SECOND...ADDED PATCHY FOG IN ACROSS THE WEST. WITH A VERY MOIST
AND CALM BOUNDARY LAYER THE LAST SEVERAL HRRR RUNS HAVE INDICATED
FOG BREAKING OUT ACROSS WESTERN NORTH DAKOTA THIS MORNING.
THIRD...LOWERED OVERNIGHT TEMPERATURES. WITH PRECIPITATION AND
CLOUDS MOVING OUT FASTER...CLEAR SKIES AND CALM WINDS HAVE ALLOWED
TEMPERATURES TO QUICKLY FALL ACROSS WESTERN NORTH DAKOTA.
UPDATE ISSUED AT 951 PM CDT WED MAY 27 2015
LIGHTNING RATES HAVE DECREASED CONSIDERABLY DURING THE PAST HOUR.
DROPPED THE THUNDERSTORM CHANCES AND WEST HIGH PROBABILITIES OF
SHOWERS CENTRAL.
UPDATE ISSUED AT 702 PM CDT WED MAY 27 2015
LATEST RADAR AND SATELLITE IMAGERY SHOWING A LINE OF SHOWERS AND
THUNDERSTORMS ACROSS WEST CENTRAL NORTH DAKOTA MOVING EAST MUCH
LIKE THE LATEST HRRR PROJECTS. BASED ON TRENDS BUMPED UP THE POPS
TO DEFINITE ACROSS CENTRAL NORTH DAKOTA. LOOKS LIKE A LULL IN
ACTIVITY FAR WEST WITH INCREASING CHANCES LATE TONIGHT WITH THE
APPROACHING COLD FRONT ON THURSDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 310 PM CDT WED MAY 27 2015
THUNDERSTORM CHANCES THIS AFTERNOON THROUGH TONIGHT AND AGAIN
THURSDAY HIGHLIGHT THE SHORT TERM FORECAST.
WILL CONTINUE TO FOLLOW THE HIGH RESOLUTION CONVECTIVE ALLOWING
GUIDANCE....NAMELY THE 17-19 UTC HRRR ITERATIONS AND 12 UTC WRF-
ARW/NMM FOR THE EVOLUTION OF CONVECTION THIS AFTERNOON AND THROUGH
THE NIGHT GIVEN THEIR GOOD HANDLING OF THE EVENT THUS FAR.
SCATTERED THUNDERSTORMS CONTINUE TO DEVELOP ALONG THE STATIONARY
FRONTAL BOUNDARY THIS AFTERNOON ARCHING FROM NORTHWEST NORTH
DAKOTA INTO THE JAMES RIVER VALLEY. MORE NUMEROUS THUNDERSTORMS
CONTINUE ACROSS WESTERN NORTH DAKOTA NEAR THE SURFACE TROUGH AXIS.
AS DEEP LAYER SHEAR INCREASES ACROSS THE SOUTHWEST WITH THE
APPROACH OF STRONGER FORCING...MARGINAL SEVERE HAIL AND WINDS ARE
POSSIBLE LATE THIS AFTERNOON AND EVENING. CONVECTION ACROSS THE
WEST IS EXPECTED TO CONGEAL THIS EVENING AS IT PROPAGATES INTO
CENTRAL NORTH DAKOTA...LIFTING INTO THE DEVILS LAKE BASIN AND RED
RIVER VALLEY BY 09-11 UTC.
FOR THURSDAY...SPC HAS EXPANDED THEIR MARGINAL THREAT AREA IN THE
DAY TWO OUTLOOK TO INCLUDE MOST OF CENTRAL NORTH DAKOTA. ML CAPE
VALUES OF 1000-1500 J/KG ARE ANTICIPATED IN THE VICINITY OF THE
PRE-FRONTAL TROUGH AHEAD OF THE STRONG COLD FRONT ENTERING THE
NORTHWEST PORTION OF THE STATE. HOWEVER...DEEP LAYER SHEAR FOR
SUPERCELLS IS MARGINAL...ON THE ORDER OF 20-30 KTS. THUS...A FEW
STRONG TO SEVERE STORMS ARE POSSIBLE WITH LARGE HAIL AND DAMAGING
WINDS BEING THE PRIMARY THREATS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 310 PM CDT WED MAY 27 2015
FROST POTENTIAL SATURDAY MORNING AND AN ACTIVE WEATHER PATTERN
NEXT WEEK HIGHLIGHT THE EXTENDED FORECAST.
A COOL FRIDAY IS EXPECTED IN THE WAKE OF THE AFOREMENTIONED COLD
FRONT IN THE SHORT TERM...WITH HIGHS IN THE UPPER 50S TO MID 60S.
AS A SURFACE RIDGE AXIS BUILDS INTO THE STATE ON FRIDAY...A COOL
FRIDAY NIGHT INTO SATURDAY MORNING IS POSSIBLE WITH LOWS IN THE 30S
AND POTENTIAL FROST. THEREAFTER...A RETURN TO AN ACTIVE WEATHER
PATTERN COMMENCES SUNDAY INTO WEDNESDAY AS THE UPPER LEVEL FLOW
PATTERN TRANSITIONS FROM ZONAL TO SOUTHWEST ALOFT. THIS WILL HAVE
TO BE MONITORED FOR SEVERE POTENTIAL. GIVEN GOOD AGREEMENT...A
BLEND OF THE 12 UTC DETERMINISTIC AND ENSEMBLE SUITES WERE USED
FOR MOST FIELDS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1241 AM CDT THU MAY 28 2015
RAIN SHOWERS HAVE ENDED AT ALL BUT KJMS. LATEST MODELS STILL
FORECAST MVFR/IFR CONDITIONS FORMING EARLY THIS MORNING AT
KDIK/KMOT/KISN. SOME UNCERTAINTY IF THIS WILL BE IFR OF MORE
MVFR. TRENDING TO THE MORE POSITIVE MVFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1130 PM CDT WED MAY 27 2015
.UPDATE...
ISSUED AT 1130 PM CDT WED MAY 27 2015
EVERYTHING CONTINUES TO BE ON TRACK OVERNIGHT...WITH INCREASING
CHANCES FOR A CLUSTER OF SHOWERS AND A FEW STORMS TO MOVE FROM
WEST TO EAST. NO CHANGES NEEDED.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 255 PM CDT WED MAY 27 2015
FORECAST CHALLENGE FOR THE SHORT TERM CONTINUES TO BE AFTERNOON
CONVECTION POTENTIAL (LOW) AND THE EVOLUTION OF SYSTEM EXPECTED TO
IMPACT REGION BY TOMORROW MORNING AND THROUGHOUT THE DAY ON
THURSDAY. MODELS CONTINUE TO VARY ON EXACT PLACEMENT OF
PRECIP...AND PRIMARILY USED SUPERBLEND AND NAM TO ADD SOME DETAIL.
FOR THE IMMEDIATE SHORT TERM...USING HI RES MODELS FOR GUIDANCE ON
LATE AFTN SHOWERS/TSTMS POTENTIAL.
THIS EVENING...SPC MESOSCALE ANALYSIS SHOWING MU CAPE BLAND ALONG
NORTHERN TIER OF COUNTIES SOUTH OF INTL BORDER AND NORTH OF HWY 2
CORRIDOR...AS FAR EASTWARD AS HALLOCK MN. ML CAPES NOT QUITE AS
IMPRESSIVE AND SFC BASED CIN IS STILL 100 TO 250 IN THAT AREA.
OVERALL SPOTTY CONVECTION DEPICTED BY HRRR IS REASONABLE AND WILL
USE HRRR AS GUIDANCE...WHICH BASICALLY SHOWS HIGHEST CHANCES
THROUGH THE DEVILS LAKE REGION ONTO THE CENTRAL VALLEY. CIN VALUES
DECLINED RIGHT AT 21Z YESTERDAY AND EXPECT SIMILAR SITUATION THIS
AFTN.
TONIGHT...FOCUS THEN TURNS TO EVOLVING SYSTEM EXPECTED TO IMPACT
AREA LATE TONIGHT THROUGH EARLY FRIDAY MORNING. MODELS ARE SLOWER
TODAY AND HAVE DELAYED PRECIP ENTERING WESTERN CWA UNTIL AFT 06Z.
SHOULD SEE SOME SHOWERS AND STORMS DEVELOP OVER CNTRL DAKOTAS AND
MOVE INTO EASTERN ND BY MORNING.
THURSDAY...MAIN CHANGES TO ONGOING FCST WILL BE TO GO MORE TSTMS
RATHER THAN SHOWERS WITH ISOLD TSTMS. THIS IS DUE TO SHOWALTERS
BEING MORE NEGATIVE THAN YESTERDAYS 12Z RUNS...ON BOTH THE GFS AND
NAM. GFS HAS MORE IMPRESSIVE 0 TO 6 KM BULK SHEAR VALUES...AROUND
50 KTS WITHIN THE VALLEY AT 00Z FRIDAY. SPC HAS SHIFTED WESTWARD
THEIR MARGINAL RISK...INTO THE HIGHER GFS SHEAR VALUES. THE NAM
BULK SHEAR VALUES CONTINUE TO BE WEAK...DECREASING CONFIDENCE FOR
ANY SIGNIFICANT SEVERE ACTIVITY TOMORROW ALTHOUGH A HAILER OR TWO
IS CERTAINLY POSSIBLE. OVERALL SFC LOW TRACK IS A BIT FURTHER
NORTH AND BETTER SFC HEATING TO MAJORITY OF THE AREA. MODELS BRING
MOST ENHANCED PRECIP ACTIVITY INTO EASTERN ND IN THE 18Z TO 21Z
TIMEFRAME...SHIFTING TO THE MN SIDE OF THE CWA IN THE LATE
AFTERNOON INTO THE EVENING. SHOWALTERS BEGIN TO RISE AFT 06Z
FRIDAY TRANSITION BACK TO SHOWERS FROM NORTH TO SOUTH BY FRI
MORNING. COLD FRONT DROPS INTO NORTHERN CWA BY 12Z FRI...BRINGING
MUCH COOLER AIR INTO THE NORTHWEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 255 PM CDT WED MAY 27 2015
FRIDAY AND SATURDAY...A VERY COOL AIRMASS ASSOCIATED WITH CANADIAN
HIGH PRESSURE SINKS INTO THE NORTHERN VALLEY. THIS WILL BRING
DAYTIME HIGHS IN THE 50S ACROSS MOST OF THE REGION...WITH SATURDAY
MORNING TEMPS AROUND THE FREEZING MARK IN THE FAR NORTH. WITH SFC
LOW OVER SRN CANADA...SPOTTY FROST IS POSSIBLE IN COUNTIES
ADJACENT TO THE INTL BORDER.
SATURDAY NIGHT THROUGH WEDNESDAY...MID LEVEL ZONAL FLOW WILL
GRADUALLY TRANSITION TO SW FLOW PATTERN SETTING UP POTENTIALLY
ACTIVE...MORE SUMMER TYPE CONVECTIVE PERIOD NEXT WEEK. WEAK
SHORTWAVE WILL TRACK ACROSS S CANADIAN PROVINCES SUNDAY. THIS AND
WARM ADVECTION COULD HELP SET OFF MAINLY SHRA ACROSS THE REGION.
PERSISTENT SOUTHERLY FLOW WILL ADVECT WARMER/MORE UNSTABLE AIR
INTO THE REGION NEXT WEEK. WITH CONTINUED WARM ADVECTION EARLY
NEXT WEEK SPOTTY CONVECTION REMAINS POSSIBLE WITH BEST CHANCES
TOWARDS MID WEEK AS SHORTWAVE AND ASSOCIATED SURFACE BOUNDARY
APPROACHES THE REGION. AS UPPER FLOW TRANSITIONS TO THE SW ABOVE
BOUNDARY WILL PROPAGATE RELATIVELY SLOWLY SETTING UP POTENTIALLY
EXTENDED ACTIVE PERIOD. CAPPING MAY LIMIT BEST CONVECTIVE
POTENTIAL ACROSS THE NORTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1130 PM CDT WED MAY 27 2015
THE CHANCES FOR SHOWERS AND STORMS WILL INCREASE OVERNIGHT AND
CONTINUE ON THU. SOUTHERLY WINDS WILL INCREASE LATE TONIGHT AND
THURSDAY...AND GUST TO 25KT AT TIMES IN THE VALLEY. A COLD FRONT
WILL SHIFT WINDS TO A NORTHERLY DIRECTION AFTER 00Z FRI BEHIND A
COLD FRONT. THERE COULD BE POCKETS OF MVFR CONDITIONS NEAR
STRONGER SHOWERS AND STORMS THROUGH THU.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...SPEICHER
LONG TERM...SPEICHER/VOELKER
AVIATION...DK
AREA FORECAST DISCUSSION
NWS NORMAN OK
1039 PM CDT FRI MAY 29 2015
.DISCUSSION...
&&
.AVIATION...
THUNDERSTORMS APPROACHING FROM THE WEST ARE EXPECTED TO MOVE
ACROSS SOUTHERN OKLAHOMA AND AREAS TO THE SOUTH EARLY SATURDAY. A
PERIOD OF MVFR CEILINGS IS EXPECTED BEHIND A WEAK COLD FRONT.
BY SATURDAY AFTERNOON LOW CLOUDS AND RAIN ARE EXPECTED TO HAVE
MOVED SOUTH AND EAST OF CENTRAL AND WESTERN OKLAHOMA.
&&
.PREV DISCUSSION... /ISSUED 733 PM CDT FRI MAY 29 2015/
UPDATE...
ADJUSTED PRECIP/WX THROUGH MIDNIGHT...
DISCUSSION...
WATCHING SATELLITE TRENDS CLOSELY THIS EVENING AS THE CONVECTION
CONTINUES TO EVOLVE OVER NERN NM. THROUGH 7PM... STORMS HAVE
STARTED TO PUSH INTO THE W TX PH. TO THE NORTH... CONVECTION HAS
FINALLY DEVELOPED ALONG THE FRONTAL BOUNDARY IN WRN KS. FOR THE
MOMENT... TRIMMED BACK PRECIP CHCS ACROSS THE REGION... LEAVING
SLIGHTS IN THROUGH 10PM AS A FEW SHOWERS MAY DRIFT INTO FAR NWRN
OK. THE CURRENT HRRR INITIALIZED SIMILAR TO CURRENT CONDITIONS...
BUT APPEARS TO BE OVER-CONVECTING ACROSS KS. HOWEVER... THE
GENERAL PATTERN APPEARS REASONABLE GIVEN THE TRENDS. EXPECT THE
STORMS ON THE LLANO ESTACADO TO CONTINUE TO BUILD EASTWARD THIS
EVENING... DEVELOPING INTO A COMPLEX AND MOVING E/SE INTO NRN TX.
SUPPORTED BY A MODEST SWATH OF 2000 TO 3000 J/KG MUCAPES AND GOOD
SHEAR/COLD POOL BALANCE...FORWARD PROP VECTORS WOULD SUGGEST A SE
TRACK... POSSIBLY CLIPPING FAR SWRN OK/WRN N TX LATE TONIGHT/EARLY
SAT MORNING BEFORE THE FRONTAL BOUNDARY ARRIVES ALONG THE RED
RIVER AROUND SUNRISE.
DID NOT MAKE ANY MAJOR CHANGES TO THE GOING PRECIP/WX FORECAST
FROM THIS AFTN AFTER 1 AM... AS MUCH OF WHAT OCCURS OVERNIGHT WILL
BE DIRECTLY DEPENDENT ON CURRENT CONVECTION AND THEIR
TIMING/COVERAGE AS THEY APPROACH OK AND NRN TX. RAINFALL ALONG
THE RED AND WICHITA RIVER BASINS REMAINS A CONCERN... AS
FORECASTING WHERE THE HEAVIEST BAND OF PRECIP SETS UP AND MOVES
THROUGH REMAINS A CHALLENGE AND IMPACTS THE CURRENT FLOOD
SITUATION. CURRENT THOUGHTS WOULD BE FOR THE COMPLEX TO MOVE
ACROSS THE UPPER RED BASINS IN THE TEXAS PANHANDLE AND FAR SWRN
OK AND CLIP THE WRN WICHITA BASIN. HOW MUCH RAIN REMAINS DEPENDENT
ON THE TIMING AND IMPACT FROM THE ARRIVAL OF THE FRONT... WHICH
MAY SLOW AND INCREASE PRECIP SLIGHTLY. WITH THIS UNCERTAINTY...
MADE ONLY MINOR ADJUSTMENTS TO GOING PRECIP TOTAL FORECAST.
WITH A HALF TO AN INCH AND A QUARTER POSSIBLE ACROSS PORTIONS OF
WRN N TX... THE CURRENT FORECAST FOR THE WICHITA RIVER TO CREST AT
WICHITA FALLS AT MINOR FLOOD STAGE...18 TO 19 FEET... BY SUNDAY
REMAINS THE MOST LIKELY SCENARIO.
JTK
PREV DISCUSSION... /ISSUED 651 PM CDT FRI MAY 29 2015/
AVIATION...
A WEAK FRONT WILL MOVE THROUGH OKLAHOMA THIS EVENING FOLLOWED BY A
STRONGER FRONT OVERNIGHT. THUNDERSTORMS APPROACHING FROM THE WEST ARE
EXPECTED TO MOVE ACROSS SOUTHERN OKLAHOMA AND AREAS TO THE SOUTH
AFTER MIDNIGHT. A PERIOD OF MVFR CEILINGS IS EXPECTED BEHIND THE
SECOND FRONT EARLY SATURDAY. BY SATURDAY AFTERNOON LOW CLOUDS AND
RAIN ARE EXPECTED TO HAVE MOVED SOUTH AND EAST OF CENTRAL AND
WESTERN OKLAHOMA.
PREV DISCUSSION... /ISSUED 302 PM CDT FRI MAY 29 2015/
DISCUSSION...
THE MAIN CONCERNS AGAIN THIS FORECAST ARE CHANCES FOR STRONG TO
SEVERE STORMS AND HEAVY RAINFALL/FLOODING.
IF WE CAN MAKE IT THROUGH TODAY AND TONIGHT...WE`LL BE IN FOR A
LONG OVERDUE BREAK FROM THE ACTIVE WEATHER OF LATE. IN THE WORKS
FOR TODAY...TWO UPPER LEVEL STORM SYSTEMS AND A POTENT COLD
FRONT...ALONG WITH ABUNDANT MOISTURE AND SUBTLE BOUNDARIES/WAVES.
IN SHORT...ANOTHER MESSY AND UNCLEAR FORECAST IN WHICH THERE ISN`T
MUCH CONFIDENCE.
RECENT SHORT TERM AND HI-RES MODELS ARE TRENDING A BIT FASTER
WITH THE COLD FRONT...AND DEPICT LITTLE TO NO SHOWER OR STORM
ACTIVITY ALONG/BEHIND THE FRONT AS IT MOVES ACROSS NORTHERN AND
CENTRAL OKLAHOMA. GIVEN THE DEGREE OF MOISTURE...EXPECT THIS MAY
BE A BIT OPTIMISTIC AND WILL MAINTAIN CHANCE POPS ACROSS
NORTHERN/CENTRAL OKLAHOMA. FURTHER SOUTH...ALONG THE RED RIVER AND
DOWN INTO NORTH TEXAS...THE FORECAST THROUGH TONIGHT IS MORE
COMPLEX. THUNDERSTORMS ARE IN THE PROCESS OF DEVELOPING ACROSS
EASTERN NEW MEXICO AND FAR WEST TEXAS. THESE ARE EXPECTED TO
EVENTUALLY MERGE INTO A EASTWARD PROPAGATING COMPLEX THIS EVENING
AND OVERNIGHT...EVENTUALLY REACHING WESTERN NORTH TEXAS AND FAR
SOUTHWESTERN OKLAHOMA BY THIS EVENING. THIS COMPLEX MAY POSE A
RISK OF DAMAGING WINDS AND MARGINALLY SEVERE HAIL...BUT THE ISSUE
OF GREATER CONCERN WILL BE ADDITIONAL HEAVY RAIN AND FLASH
FLOODING. THIS WILL ESPECIALLY BE THE CASE AS THE COMPLEX
INTERACTS WITH THE AFOREMENTIONED COLD FRONT...ACTING TO ENHANCE
HEAVY RAINFALL POTENTIAL ALONG AND JUST NORTH OF THE FRONT. THIS
LOOKS TO BE MOST LIKELY ALONG THE RED RIVER AND INTO NORTH
TEXAS...SO THE POTENTIAL FOR FLASH FLOODING WILL CERTAINLY PERSIST
INTO TONIGHT. DESPITE SOME CONFIDENCE IN LESSER STORM CHANCES
ACROSS NORTHERN OKLAHOMA...WILL GO AHEAD AND LEAVE THE FLASH FLOOD
WATCH AS IS...GIVEN THE UNCERTAINTIES IN FRONTAL TIMING AND EXTENT
OF FRONTAL CONVECTION.
BY TOMORROW...SHOWERS AND STORMS WILL LIKELY BE ONGOING IN THE
MORNING. BUT AS COOLER DRIER AIR FILLS IN BEHIND THE FRONT...THIS
ACTIVITY SHOULD GRADUALLY WORK ITS WAY SOUTH AND EAST...LEAVING A
CLOUDY BUT DRY CONDITIONS IN ITS WAKE. OPPORTUNITIES FOR
SHOWERS/STORMS APPEAR TO BE FEW AND FAR BETWEEN FROM SUNDAY ON
INTO NEXT WEEK. WE WILL HAVE TO KEEP AN EYE ON A RETROGRADING LOW
OVER THE NORTHERN GULF...WHICH MIGHT GENERATE SOME SPOTTY SHOWER
ACTIVITY LATE NEXT WEEK ACROSS SOUTHERN/EASTERN OKLAHOMA.
OTHERWISE...EXPECT WARMER AND MORE HUMID CONDITIONS FOR MUCH OF
THE UPCOMING WEEK.
AUSTIN
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 61 72 57 76 / 40 20 0 0
HOBART OK 60 73 54 78 / 50 10 0 0
WICHITA FALLS TX 64 76 58 79 / 80 40 10 0
GAGE OK 55 71 51 78 / 30 10 0 0
PONCA CITY OK 59 72 54 76 / 20 10 0 0
DURANT OK 65 75 60 77 / 80 60 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR OKZ004>048-
050>052.
TX...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR TXZ083>090.
&&
$$
04/09/09
AREA FORECAST DISCUSSION
NWS NORMAN OK
733 PM CDT FRI MAY 29 2015
.UPDATE...
ADJUSTED PRECIP/WX THROUGH MIDNIGHT...
&&
.DISCUSSION...
WATCHING SATELLITE TRENDS CLOSELY THIS EVENING AS THE CONVECTION
CONTINUES TO EVOLVE OVER NERN NM. THROUGH 7PM... STORMS HAVE
STARTED TO PUSH INTO THE W TX PH. TO THE NORTH... CONVECTION HAS
FINALLY DEVELOPED ALONG THE FRONTAL BOUNDARY IN WRN KS. FOR THE
MOMENT... TRIMMED BACK PRECIP CHCS ACROSS THE REGION... LEAVING
SLIGHTS IN THROUGH 10PM AS A FEW SHOWERS MAY DRIFT INTO FAR NWRN
OK. THE CURRENT HRRR INITIALIZED SIMILAR TO CURRENT CONDITIONS...
BUT APPEARS TO BE OVER-CONVECTING ACROSS KS. HOWEVER... THE
GENERAL PATTERN APPEARS REASONABLE GIVEN THE TRENDS. EXPECT THE
STORMS ON THE LLANO ESTACADO TO CONTINUE TO BUILD EASTWARD THIS
EVENING... DEVELOPING INTO A COMPLEX AND MOVING E/SE INTO NRN TX.
SUPPORTED BY A MODEST SWATH OF 2000 TO 3000 J/KG MUCAPES AND GOOD
SHEAR/COLD POOL BALANCE...FORWARD PROP VECTORS WOULD SUGGEST A SE
TRACK... POSSIBLY CLIPPING FAR SWRN OK/WRN N TX LATE TONIGHT/EARLY
SAT MORNING BEFORE THE FRONTAL BOUNDARY ARRIVES ALONG THE RED
RIVER AROUND SUNRISE.
DID NOT MAKE ANY MAJOR CHANGES TO THE GOING PRECIP/WX FORECAST
FROM THIS AFTN AFTER 1 AM... AS MUCH OF WHAT OCCURS OVERNIGHT WILL
BE DIRECTLY DEPENDENT ON CURRENT CONVECTION AND THEIR
TIMING/COVERAGE AS THEY APPROACH OK AND NRN TX. RAINFALL ALONG
THE RED AND WICHITA RIVER BASINS REMAINS A CONCERN... AS
FORECASTING WHERE THE HEAVIEST BAND OF PRECIP SETS UP AND MOVES
THROUGH REMAINS A CHALLENGE AND IMPACTS THE CURRENT FLOOD
SITUATION. CURRENT THOUGHTS WOULD BE FOR THE COMPLEX TO MOVE
ACROSS THE UPPER RED BASINS IN THE TEXAS PANHANDLE AND FAR SWRN
OK AND CLIP THE WRN WICHITA BASIN. HOW MUCH RAIN REMAINS DEPENDENT
ON THE TIMING AND IMPACT FROM THE ARRIVAL OF THE FRONT... WHICH
MAY SLOW AND INCREASE PRECIP SLIGHTLY. WITH THIS UNCERTAINTY...
MADE ONLY MINOR ADJUSTMENTS TO GOING PRECIP TOTAL FORECAST.
WITH A HALF TO AN INCH AND A QUARTER POSSIBLE ACROSS PORTIONS OF
WRN N TX... THE CURRENT FORECAST FOR THE WICHITA RIVER TO CREST AT
WICHITA FALLS AT MINOR FLOOD STAGE...18 TO 19 FEET... BY SUNDAY
REMAINS THE MOST LIKELY SCENARIO.
JTK
&&
.PREV DISCUSSION... /ISSUED 651 PM CDT FRI MAY 29 2015/
AVIATION...
A WEAK FRONT WILL MOVE THROUGH OKLAHOMA THIS EVENING FOLLOWED BY A
STRONGER FRONT OVERNIGHT. THUNDERSTORMS APPROACHING FROM THE WEST ARE
EXPECTED TO MOVE ACROSS SOUTHERN OKLAHOMA AND AREAS TO THE SOUTH
AFTER MIDNIGHT. A PERIOD OF MVFR CEILINGS IS EXPECTED BEHIND THE
SECOND FRONT EARLY SATURDAY. BY SATURDAY AFTERNOON LOW CLOUDS AND
RAIN ARE EXPECTED TO HAVE MOVED SOUTH AND EAST OF CENTRAL AND
WESTERN OKLAHOMA.
PREV DISCUSSION... /ISSUED 302 PM CDT FRI MAY 29 2015/
DISCUSSION...
THE MAIN CONCERNS AGAIN THIS FORECAST ARE CHANCES FOR STRONG TO
SEVERE STORMS AND HEAVY RAINFALL/FLOODING.
IF WE CAN MAKE IT THROUGH TODAY AND TONIGHT...WE`LL BE IN FOR A
LONG OVERDUE BREAK FROM THE ACTIVE WEATHER OF LATE. IN THE WORKS
FOR TODAY...TWO UPPER LEVEL STORM SYSTEMS AND A POTENT COLD
FRONT...ALONG WITH ABUNDANT MOISTURE AND SUBTLE BOUNDARIES/WAVES.
IN SHORT...ANOTHER MESSY AND UNCLEAR FORECAST IN WHICH THERE ISN`T
MUCH CONFIDENCE.
RECENT SHORT TERM AND HI-RES MODELS ARE TRENDING A BIT FASTER
WITH THE COLD FRONT...AND DEPICT LITTLE TO NO SHOWER OR STORM
ACTIVITY ALONG/BEHIND THE FRONT AS IT MOVES ACROSS NORTHERN AND
CENTRAL OKLAHOMA. GIVEN THE DEGREE OF MOISTURE...EXPECT THIS MAY
BE A BIT OPTIMISTIC AND WILL MAINTAIN CHANCE POPS ACROSS
NORTHERN/CENTRAL OKLAHOMA. FURTHER SOUTH...ALONG THE RED RIVER AND
DOWN INTO NORTH TEXAS...THE FORECAST THROUGH TONIGHT IS MORE
COMPLEX. THUNDERSTORMS ARE IN THE PROCESS OF DEVELOPING ACROSS
EASTERN NEW MEXICO AND FAR WEST TEXAS. THESE ARE EXPECTED TO
EVENTUALLY MERGE INTO A EASTWARD PROPAGATING COMPLEX THIS EVENING
AND OVERNIGHT...EVENTUALLY REACHING WESTERN NORTH TEXAS AND FAR
SOUTHWESTERN OKLAHOMA BY THIS EVENING. THIS COMPLEX MAY POSE A
RISK OF DAMAGING WINDS AND MARGINALLY SEVERE HAIL...BUT THE ISSUE
OF GREATER CONCERN WILL BE ADDITIONAL HEAVY RAIN AND FLASH
FLOODING. THIS WILL ESPECIALLY BE THE CASE AS THE COMPLEX
INTERACTS WITH THE AFOREMENTIONED COLD FRONT...ACTING TO ENHANCE
HEAVY RAINFALL POTENTIAL ALONG AND JUST NORTH OF THE FRONT. THIS
LOOKS TO BE MOST LIKELY ALONG THE RED RIVER AND INTO NORTH
TEXAS...SO THE POTENTIAL FOR FLASH FLOODING WILL CERTAINLY PERSIST
INTO TONIGHT. DESPITE SOME CONFIDENCE IN LESSER STORM CHANCES
ACROSS NORTHERN OKLAHOMA...WILL GO AHEAD AND LEAVE THE FLASH FLOOD
WATCH AS IS...GIVEN THE UNCERTAINTIES IN FRONTAL TIMING AND EXTENT
OF FRONTAL CONVECTION.
BY TOMORROW...SHOWERS AND STORMS WILL LIKELY BE ONGOING IN THE
MORNING. BUT AS COOLER DRIER AIR FILLS IN BEHIND THE FRONT...THIS
ACTIVITY SHOULD GRADUALLY WORK ITS WAY SOUTH AND EAST...LEAVING A
CLOUDY BUT DRY CONDITIONS IN ITS WAKE. OPPORTUNITIES FOR
SHOWERS/STORMS APPEAR TO BE FEW AND FAR BETWEEN FROM SUNDAY ON
INTO NEXT WEEK. WE WILL HAVE TO KEEP AN EYE ON A RETROGRADING LOW
OVER THE NORTHERN GULF...WHICH MIGHT GENERATE SOME SPOTTY SHOWER
ACTIVITY LATE NEXT WEEK ACROSS SOUTHERN/EASTERN OKLAHOMA.
OTHERWISE...EXPECT WARMER AND MORE HUMID CONDITIONS FOR MUCH OF
THE UPCOMING WEEK.
AUSTIN
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 79 61 72 57 / 20 40 20 0
HOBART OK 81 60 73 54 / 30 50 10 0
WICHITA FALLS TX 81 64 76 58 / 20 80 40 10
GAGE OK 81 55 71 51 / 30 30 10 0
PONCA CITY OK 76 59 72 54 / 30 20 10 0
DURANT OK 77 65 75 60 / 70 80 60 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR OKZ004>048-
050>052.
TX...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS TULSA OK
1153 PM CDT WED MAY 27 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
FOR THE 6Z TAFS... VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES
WITH MID AND HIGH OVERCAST. SCATTERED THUNDERSTORMS WILL DEVELOP
THURSDAY DURING THE DAY... LASTING THROUGHOUT THE REMAINDER OF THE
FORECAST PERIOD. THERE WILL BE A FAIRLY LOW PROBABILITY OF A STORM
AFFECTING ANY PARTICULAR SITE
&&
.PREV DISCUSSION... /ISSUED 937 PM CDT WED MAY 27 2015/
DISCUSSION...
THUNDERSTORMS IN FAR NORTHWEST ARKANSAS HAVE EITHER DISSIPATED OR
MOVED NORTH OF THE AREA. THE LATEST HRRR SUGGESTS A MAINLY DRY
NIGHT WITH RAIN CHANCES INCREASING DURING THE MORNING THURSDAY.
WILL LOWER POPS SLIGHTLY IN SOME PLACES OVERNIGHT AND MAKE A FEW
OTHER MINOR FIRST PERIOD CHANGES.
UPDATE ON THE WAY.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
658 PM CDT FRI MAY 29 2015
.AVIATION... /00Z TAF UPDATE/
NO CONVECTION IS EXPECTED TO IMPACT TAFS FOR THE FIRST 9-12 HOURS.
SATURATED SOILS SHOULD INTERACT WITH MODERATE SURFACE SOUTHERLIES
TO FORM LOW CLOUDS BEFORE MIDNIGHT...WITH PERHAPS A SLIGHT DELAY
OVER THE RIO GRANDE PLAINS AND THE DRT AREA. NOCTURNAL BOUNDARY
LAYER WIND ENHANCEMENTS LOOK CONSERVATIVE IN MODEL TIME
SECTIONS...SUGGESTING AN ABUNDANCE OF IFR CONDITIONS LATE TONIGHT.
A WEAKENING STORM COMPLEX IS EXPECTED OVER CENTRAL TX BY
DAYBREAK...POSSIBLY A BIT FASTER IF RECENT RUNS OF THE HRRR
VERIFY. WILL STICK WITH THE MORE CONSERVATIVE TX TECH WRF AND THE
COARSER SCALE MODELS FOR THIS EVENING...AS THE LATE
AFTERNOON/EARLY EVENING RUNS OF THE HRRR HAVE SEEMED TO BE RUNNING
TOO AGGRESSIVE OVER THE PAST WEEK.
&&
.PREV DISCUSSION... /ISSUED 254 PM CDT FRI MAY 29 2015/
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
..LOCALLY HEAVY RAINFALL POSSIBLE SATURDAY ACROSS SOUTH CENTRAL
TEXAS...
RECOVERY AFTER LAST NIGHTS MCS IS SLOWLY TAKING PLACE WEST TO
EAST ACROSS THE CWA. CAN NOT COMPLETELY RULE OUT AN ISOLATED
STORM THROUGH SUNSET...BUT THE MAJORITY OF THE CWA WILL REMAIN
DRY THROUGH THE REMAINDER OVER THE AFTERNOON AND EVENING.
UPSTREAM...MODELS ARE INDICATING ANOTHER ORGANIZED COMPLEX OF
STORMS DEVELOPING THIS EVENING ACROSS NORTHWEST TEXAS MOVING
SOUTHEAST THROUGH WEST-CENTRAL TEXAS OVERNIGHT. PAST FEW HRRR
RUNS AND 12Z TT 4KM WRF ARE INDICATING THIS POTENTIAL LINE OF
STORMS REACHING THE NORTHERN HILL COUNTRY 09Z-12Z. UNLIKE LAST
NIGHT...THIS COMPLEX MAY WEAKEN AS IT MOVES INTO THE HILL COUNTRY
AND CENTRAL TEXAS SATURDAY MORNING. HOWEVER...OUTFLOW BOUNDARIES
LEFT OVER AND AN EVENTUAL WEAK COLD FRONT...WILL LIKELY TRIGGER
ADDITIONAL SHOWERS AND STORMS SATURDAY AFTERNOON AND EVENING
ACROSS MUCH OF SOUTH-CENTRAL TEXAS. AT THIS TIME...FORECASTING
TIMING AND LOCATIONS OF HEAVIEST AMOUNTS OF PRECIP ARE VERY
DIFFICULT...AS LARGER SCALE FORCING IS RELATIVELY WEAK.
HOWEVER...FORECAST SOUNDINGS INDICATE RATHER LARGE CAPE VALUES
ACROSS THE SOUTHERN HALF OF THE CWA SATURDAY AFTERNOON...EXCEEDING
3500 J/KG. WHEN COMBINED WITH SLOW STORM MOTIONS ACROSS CENTRAL
AND EASTERN CWA...LOCALLY HEAVY RAINFALL IS A POSSIBILITY SATURDAY
INTO SATURDAY NIGHT. A FEW STRONG STORMS POSSIBLE OUT WEST ALONG
THE RIO GRANDE WHERE BETTER DEEP LAYER SHEAR IS FORECAST. OVERALL
RAINFALL AMOUNTS OF AROUND 1 INCH ARE POSSIBLE...WITH ISOLATED
AMOUNTS OF 2-3 INCHES. GIVEN THE SATURATED CONDITIONS ACROSS THE
AREA...A QUICK 1-3 INCHES WILL CAUSE FLASH FLOODING ISSUES IN
SEVERAL AREAS. OUT OF AN ABUNDANCE OF CAUTION...HAVE ELECTED TO
ISSUE A FLASH FLOOD WATCH FOR SATURDAY AND SATURDAY NIGHT.
LONG TERM (SUNDAY THROUGH FRIDAY)...UPPER LEVEL TROUGH TO THE
WEST DEEPENS SUNDAY INTO MONDAY ACROSS AR AND LA. BETTER MOISTURE
ON SUNDAY REMAINS POOLED ACROSS THE SOUTHERN AND WESTERN CWA...
AND FARTHER TO THE SOUTH. CAN NOT RULE OUT SCATTERED SHOWERS AND
STORMS IN THIS AREA SUNDAY...BUT FORCING APPEARS RATHER LIMITED.
FINALLY DRIER CONDITIONS WILL TAKE PLACE ALONG AND WEST OF THE
I-35 CORRIDOR MONDAY-THURSDAY. CAN NOT RULE OUT ISOLATED SHOWERS
AND STORMS MONDAY THROUGH THURSDAY ACROSS THE COASTAL PRAIRIES
CLOSER TO BETTER MOISTURE AND LOWER HEIGHTS WITH THE TROUGH TO
THE EAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 71 83 67 82 64 / 30 70 40 20 10
AUSTIN BERGSTROM INTL AIRPORT 70 83 65 81 62 / 30 70 40 30 10
NEW BRAUNFELS MUNI AIRPORT 71 85 66 83 64 / 20 70 50 30 10
BURNET MUNI AIRPORT 70 80 64 80 62 / 50 70 40 20 10
DEL RIO INTL AIRPORT 74 86 67 86 68 / 20 70 40 30 10
GEORGETOWN MUNI AIRPORT 70 81 65 81 62 / 40 70 40 20 10
HONDO MUNI AIRPORT 72 86 66 83 65 / 20 70 40 40 10
SAN MARCOS MUNI AIRPORT 71 83 66 81 64 / 20 70 50 30 10
LA GRANGE - FAYETTE REGIONAL 72 84 68 82 65 / 10 70 50 40 10
SAN ANTONIO INTL AIRPORT 73 86 68 83 66 / 20 70 50 30 10
STINSON MUNI AIRPORT 73 86 68 83 66 / 10 70 50 40 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM SATURDAY MORNING THROUGH SUNDAY MORNING FOR
THE FOLLOWING COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...
BLANCO...BURNET...CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...
FAYETTE...FRIO...GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...
KENDALL...KERR...KINNEY...LAVACA...LEE...LLANO...MAVERICK...
MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...WILLIAMSON...WILSON...
ZAVALA.
&&
$$
MESOSCALE/AVIATION...OAKS
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
406 PM CDT THU MAY 28 2015
.DISCUSSION...
BEFORE WE TALK ABOUT ALL THE UPCOMING THUNDERSTORM CHANCES FOR THE
WEEKEND...HOUSTON IAH DID REACH 90F TODAY WHICH IS THE FIRST TIME
HITTING 90 DEGREES IN 2015. THE LAST TIME HOUSTON IAH HAD A 90
DEGREE DAY WAS OCTOBER 10 2014. AVERAGE 1ST DAY OF 90 DEGREES AT
HOUSTON IAH IS AROUND MAY 7.
HOPEFULLY EVERYONE ENJOYED SOME BREAK IN THE RAINFALL. THIS
WEEKEND LOOKS TO BE ANOTHER WET WEEKEND WITH PROBABLY 2 PERIODS OF
WHEN HEAVY RAINFALL COULD OCCUR. CURRENT WATER VAPOR IMAGERY SHOWS
2 UPPER LEVEL TROUGHS...ONE MOVING THROUGH THE S ROCKIES AND W TX
WHICH SHOULD IMPACT THE AREA TOMORROW AND A SECOND TROUGH MOVING
THROUGH THE N ROCKIES WHICH WILL SUPPORT THUNDERSTORM ACTIVITY
LATE SAT INTO SUN.
WE ARE ALSO MONITORING THUNDERSTORM ACTIVITY IN W TX WHICH MAY
FORM INTO A SQUALL LINE. LAST FEW RUNS OF THE HRRR CONTINUE TO
HOLD THIS LINE OF STORMS TOGETHER AND HAVE IT REACHING WESTERN
PORTIONS OF SE TX AFTER MIDNIGHT. IT LOOKS LIKE THIS ACTIVITY MAY
WEAKEN BEFORE REACHING HOUSTON BUT STILL SOMETHING TO MONITOR.
SHOULD IT HOLD TOGETHER...STRONG WINDS AND SMALL HAIL WILL BE A
THREAT ALONG WITH HEAVY RAINFALL. GIVEN THE UNCERTAINTY A FLASH
FLOOD WATCH WILL NOT BE ISSUED AS IS THE CASE IN C TX AND N TX.
MODELS STILL HAVE THE INFLUENCE OF THE UPPER TROUGH OVER SE TX
TOMORROW. ALOFT THERE SHOULD BE AT LEAST SOME COOLING WITH LARGE
SCALE ASCENT AND DIFFLUENCE IN THE THE JET TO SUPPORT BROAD LIFT.
DAY TIME HEATING ALLOWING FOR TEMPS IN THE MID/UPPER 80S SHOULD
AGAIN SUPPORT CONVECTIVE INITIATION. PRECIP WATER VALUES SHOULD BE
AROUND 1.6-1.8 INCHES WITH A SWATH OF 1.8 INCH PW FROM COLLEGE
STATION TO LUFKIN. THIS SEEMS TO BE THE MORE LIKELY AREA FOR HEAVY
RAINFALL ALTHOUGH THERE IS NOT A BOUNDARY TO FOCUS CONVECTION.
MESOSCALE INTERACTIONS WILL BE A BIG KEY FOR FURTHER CONVECTIVE
DEVELOPMENT TOMORROW. MODEL SOUNDINGS DO INDICATE WEAK CAPPING
ALONG THE COAST WITH THE CAP WEAKEST NORTH OF HOUSTON. ORIENTED 50
POPS FOR HOUSTON NORTHWARD BASED ON CAPPING AND LOWER PRECIP
WATER ALONG THE COAST.
MORE FAVORABLE SET UP FOR HEAVY RAINFALL LOOKS TO BE LATE SATURDAY
INTO SUNDAY. BY 00Z SUN MODELS ARE IN PRETTY GOOD AGREEMENT WITH
UPPER LEVEL TROUGH AXIS DROPPING INTO THE S PLAINS. A COLD FRONT
WITH THIS SYSTEM ALSO PUSHES INTO TX AND LOOKS TO STALL ACROSS THE
AREA OVERNIGHT. THE FRONT MAY MAKE SOME SLOW PROGRESS SOUTHWARD
AND OFF THE COAST LATER ON SUNDAY. UPPER LEVEL WINDS WILL BE WEAK
AND DIFFLUENT DURING THIS TIME. THE FRONT WILL LIKELY FOCUS
THUNDERSTORM ACTIVITY LATE SAT AFTERNOON GOING INTO THE OVERNIGHT.
PRECIP WATER VALUES LOOK TO BE CLOSER TO 1.8 INCHES AREA WIDE.
MISSING FROM THIS SET UP IS A STRONG LLJ OFF THE GULF BUT STILL
THINK GIVEN FORCING FROM THE FRONT...VENTING ALOFT WITH DIFFLUENCE
AND HIGH MOISTURE WILL SUPPORT THUNDERSTORM ACTIVITY CAPABLE OF
HEAVY RAINFALL. STORMS CAPABLE OF 1-2 INCHES AN HR RAINRATES CAN
NOT BE RULED OUT AND WITH SLOW STORM MOTIONS...HIGH RAINFALL
TOTALS CAN BE ACHIEVED. WE WILL BE WATCHING THIS TIME FRAME FOR A
FLASH FLOOD WATCH. ANY STORMS OF THESE STORMS COULD PRODUCE OVER 3
INCHES OF RAIN VERY QUICKLY WHICH WILL CAUSE FLOODING PROBLEMS.
WITH THE FRONT SLOWLY MOVING OFF THE COAST...MORE STORMS MAY BE
EXPECTED SUNDAY. EXPECT THERE TO BE SOME BREAK IN CONVECTION
DURING THE MORNING BUT COULD SEE MORE ACTIVITY ALONG THE COAST
WITH DAY TIME HEATING. TROUGH AXIS ALOFT WILL STILL BE OVER THE
AREA AS THE UPPER TROUGH BEGINS TO SLOWLY CLOSE OFF FROM THE MAIN
FLOW. DRIER AIR MAY FILTER INTO THE REGION LATE SUNDAY INTO MONDAY
BEHIND THE FRONT. WHILE WE WISH WE COULD END THUNDERSTORM
CHANCES...MAIN PROBLEM IS THAT UPPER LOW CLOSES OFF MON INTO TUE
OVER LOUISIANA. ECMWF TAKES THIS LOW A BIT FARTHER EAST. IT IS
STILL POSSIBLE THAT SE TX WILL BE ON THE BACK SIDE OF THE TROUGH
AND SUBSIDENCE MAY LIMIT ACTIVITY. DESPITE THAT MODELS STILL
CONTINUE TO DEVELOP PRECIP AND CONVECTION WITH DAY TIME HEATING.
POSSIBLY BY WED/THU NEXT WEEK WE WILL GET A BREAK FROM
THUNDERSTORM CHANCES.
&&
.MARINE...
THE SLIGHT TIGHTENING OF THE PRESSURE GRADIENT TONIGHT (IN RESPONSE
TO THE FIRST OF A SERIES OF UPPER LEVEL DISTURBANCES FROM THE WEST)
WILL HELP TO INCREASE WINDS A BIT TONIGHT. AT THIS TIME NOT EXPECT-
ING MUCH MORE THAN MARGINAL SCEC CONDITIONS OVERNIGHT...BUT ANOTHER
SYSTEM LATE FRI/EARLY SAT COULD BE STRONG ENOUGH FOR SCEC FLAGS FOR
THAT TIMEFRAME. MODELS STILL CALLING FOR A WEAK COLD FRONT TO STALL
OVER SE TX SUNDAY...AND ITS PROXIMITY MAY BRIEFLY BACK WINDS TO THE
EAST AT THAT TIME. OTHERWISE...THE VERY WEAK PRESSURE GRADIENT WILL
PRODUCE LIGHT ONSHORE WINDS INTO NEXT MON/TUES. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 85 70 83 67 / 40 50 20 60 50
HOUSTON (IAH) 72 86 71 85 69 / 20 50 20 60 60
GALVESTON (GLS) 77 85 76 84 74 / 20 30 20 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...41
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
346 PM CDT THU MAY 28 2015
.SHORT TERM /NOW THROUGH FRIDAY NIGHT/...LATEST WATER VAPOR IMAGERY
SHOWS A WEAK UPPER LEVEL DISTURBANCE MOVING NORTH OF DEEP SOUTH
TEXAS AND A RIDGE OVERHEAD. WATER VAPOR IMAGERY ALSO INDICATES A
STRONGER SHORTWAVE TROUGH EXTENDING FROM THE MEXICAN STATE OF SONORA
INTO ARIZONA THIS AFTERNOON. BRO RADAR SHOWS ISOLATED CONVECTION
ACROSS PORTIONS OF THE NORTHERN RANCHLANDS THIS AFTERNOON. THE MAIN
FORECAST CHALLENGE IN THE SHORT TERM WILL BE FOR POPS.
THE 500MB TROUGH OVER ARIZONA THIS AFTERNOON CONTINUE TO MOVE
NORTHEAST THROUGH THE FORECAST PERIOD. THE UPPER LEVEL DISTURBANCE
WILL MOVE ACROSS SOUTH CENTRAL TEXAS AND THE BIG BEND REGION AFTER
MIDNIGHT TONIGHT. THE CONVECTION IS EXPECTED TO DEVELOP AND MOVE
EAST AND SOUTHEAST LATER TONIGHT INTO FRIDAY MORNING. MOST OF THE
MODEL GUIDANCE KEEPS THE CONVECTION NORTH OF DEEP SOUTH TEXAS BUT
THE LATEST NAM AND THE 18Z HRRR BRING SOME ACTIVITY INTO THE AREA
LATER THIS AFTERNOON AND TODAY. WILL INCREASE POPS FOR THE REST OF
THIS AFTERNOON AND EVENING ACROSS THE WEST...ACROSS THE EASTERN
PORTIONS OF AREA ON FRIDAY. THE STORM PREDICTION CENTER HAS THE
WESTERN PORTIONS OF DEEP SOUTH TEXAS IN A MARGINAL RISK OF SEVERE
THUNDERSTORMS AND A GENERAL THUNDERSTORM RISK FOR TONIGHT...AND A
MARGINAL RISK AREA WIDE FOR FRIDAY AND FRIDAY NIGHT. THE POTENTIAL
FOR STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE ACROSS THE AREA
THROUGH FRIDAY NIGHT WITH THE BEST CHANCES REMAINING NORTH OF THE
AREA.
.LONG TERM /SATURDAY THROUGH THURSDAY/...500MB SHORTWAVE TROUGH
ACROSS THE SOUTH CENTRAL UNITED STATES SATURDAY WILL MOVE SLOWLY
EASTWARD SUNDAY BEFORE CUTTING OFF AS A CLOSED LOW ACROSS
LOUISIANA/MISSISSIPPI MONDAY INTO TUESDAY BEFORE RETROGRADING
SLOWLY WESTWARD INTO SOUTHEAST TEXAS/SOUTHWEST LA WEDNESDAY INTO
THURSDAY. AT THE SURFACE...A WEAK COLD FRONT WILL MOVE THROUGH
NORTH TX SATURDAY AND REACHING THE TX COAST LINE SUNDAY BEFORE
STALLING ACROSS THE NORTHWEST GULF OF MEXICO. LOW TO MID LEVEL
MOISTURE WILL POOL ALONG AND AHEAD OF THE FRONT AND THIS WILL
PROVIDE A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE CWA SAT
NIGHT THROUGH MONDAY WITH THE BEST CHANCE OF RAIN ON SUNDAY. RAIN
CHANCES SHOULD DIMINISH TUESDAY AS DRIER AIR INCREASES ACROSS
SOUTH TX WITH THE INCREASE IN SUBSIDENCE WEST OF THE CLOSED 500MB
LOW. A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE REST OF THE FORECAST PERIOD AS THE UPPER LEVEL LOW
ALLOWS SEABREEZE CONVECTION TO DEVELOP ACROSS THE COASTAL SECTIONS
AND MOVE INLAND DURING THE AFTERNOON WEDNESDAY AND THURSDAY.
&&
.MARINE...
NOW THROUGH FRIDAY NIGHT...LOWER PRESSURE OVER WEST TEXAS
EXTENDING INTO THE CENTRAL PLAIN STATES WILL INTERACT WITH BROAD
HIGH PRESSURE ACROSS THE GULF OF MEXICO. THIS WILL RESULT IN
MODERATE WINDS AND SEAS. EXERCISE CAUTION CONDITIONS WILL CONTINUE
ON LAGUNA MADRE FOR THE REST OF THIS AFTERNOON AND AGAIN ON FRIDAY
FOR STRONGER WINDS. A MODERATE FETCH ACROSS THE GULF WATERS WILL
MAINTAIN EXERCISE CAUTION CONDITIONS OR MARGINAL SMALL CRAFT
ADVISORIES CONDITIONS SEAS FOR TONIGHT AND FRIDAY.
SATURDAY THROUGH TUESDAY...LIGHT SOUTHEAST WINDS WILL PREVAIL
ACROSS THE COASTAL WATERS SATURDAY AS A WEAK COLD FRONT MOVES
THROUGH NORTH TEXAS. WINDS WILL SHIFT TO THE NORTHEAST SUNDAY BUT
REMAIN LIGHT AS THE WEAK COLD FRONT MOVES INTO THE NORTHWEST GULF
OF MEXICO. WINDS WILL REMAIN LIGHT AND VARIABLE MONDAY AS THE
PRESSURE GRADIENT REMAINS WEAK ACROSS THE WESTERN GULF. LIGHT
SOUTHEAST WINDS WILL RETURN TUESDAY AS LOW PRESSURE DEVELOPS
ACROSS WEST TEXAS.
&&
.HYDROLOGY...THE RIO GRANDE NEAR SAN BENITO (SBNT2) WAS NEAR 51 FEET
THIS AFTERNOON AND IS EXPECTED TO CREST NEAR 53 FEET FRIDAY
EVENING. FLOOD STAGE FOR SBNT2 IS 55 FEET. AT 55 FEET...MINOR
LOWLAND FLOODING REACHES INTO THE LOWEST SECTIONS OF THE FLOOD
PLAIN INSIDE THE LEVEES WITH NO SIGNIFICANT DAMAGE. THE RIO GRANDE
AT LOWER BROWNSVILLE (LOBT2) WAS NEAR 20 FEET THIS AFTERNOON AND
IS EXPECTED TO CREST NEAR 24 FEET LATE SATURDAY NIGHT. FLOOD
STAGE FOR LOBT2 IS 27 FEET. AT 24 FEET...THE RIVER EXCEEDS THE
LOWEST SECTIONS OF THE BANKS INSIDE THE LEVEES. THESE RIVER
FORECASTS FOR THE LOWER RIO GRANDE ARE BASED ON THE CURRENT AND
EXPECTED RELEASES FROM THE MARTE GOMEZ RESERVOIR IN MEXICO.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 79 89 79 89 / 10 20 10 20
BROWNSVILLE 79 90 77 91 / 10 20 10 20
HARLINGEN 78 92 75 92 / 10 30 10 20
MCALLEN 78 94 76 93 / 10 20 10 20
RIO GRANDE CITY 76 93 76 95 / 20 20 10 20
SOUTH PADRE ISLAND 80 85 80 87 / 10 20 10 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
63/61/BIRCHFIELD
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
307 PM CDT THU MAY 28 2015
.SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
...LOCALLY HEAVY RAINFALL POSSIBLE ACROSS MUCH OF AREA TONIGHT AND
POTENTIALLY SATURDAY AND SATURDAY NIGHT...
...SEVERE STORMS POSSIBLE ACROSS HILL COUNTRY AND RIO GRANDE
TONIGHT...
SCATTERED THUNDERSTORMS HAVE DEVELOPED THIS AFTERNOON ACROSS THE
EASTERN HALF OF THE CWA IN AN UNSTABLE AIRMASS AND RICH MOISTURE
PLUME. A FEW STRONG STORMS HAVE DEVELOPED...INCLUDING TROPICAL
FUNNELS REPORTED IN THE AUSTIN/ROUND ROCK AREA. OVERALL THIS
ACTIVITY SHOULD DIMINISH TOWARDS SUNSET.
HOWEVER...MAIN CONCERN WILL BE DEVELOPING CONVECTIVE COMPLEX
COMING OUT OF WEST TEXAS AND STORMS COMING OUT OF MEXICO. STORMS
HAVE ALREADY DEVELOPED ACROSS WEST TEXAS AND ARE BEGINNING TO FORM
IN THE HIGHER TERRAIN OF MEXICO...ALL IN ADVANCE OF APPROACHING
SHORTWAVE COMING OUT OF NM. STORMS DEVELOPING IN THE BURROUGHS OF
MEXICO COULD CROSS INTO VAL VERDE COUNTY EARLY THIS EVENING.
MUCAPE EXCEEDING 4000 J/KG AND EFFECTIVE BULK SHEAR OF 35 KTS WILL
SUPPORT STORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING
STRAIGHT LINE WINDS ACROSS VAL VERDE COUNTY. AN ISOLATED TORNADO
CAN NOT BE RULED.
SEVERAL HI RESOLUTION MODELS DEVELOP THE WEST TEXAS CONVECTION
INTO AN MCS THIS EVENING WITH PROPAGATION SOUTHEAST INTO A
STRENGTHENING 35 KT LOW LEVEL THETA-E ADVECTION AXIS UP THE RIO
GRANDE PLAINS. THE POTENTIAL MCS SHOULD MAKE IT INTO THE RIO
GRANDE AND NORTHERN HILL COUNTRY 02Z-06Z. SEVERE POTENTIAL IS
POSSIBLE IN THIS AREA...FOR MAINLY STRAIGHT-LINE WINDS.
FARTHER EASTWARD INTO THE I-35 CORRIDOR...THE CONVECTIVE COMPLEX
WILL BE ENCOUNTER INCREASING CIN AND WEAKER LOW LEVEL JET. MUCH
WILL DEPEND ON HOW STRONG OF A COLD POOL DEVELOPS BEHIND THE
COMPLEX. THE HRRR AND NAM12 DO BRING THE COMPLEX THROUGH THE I-35
CORRIDOR...WHILE TEXAS TECH 4KM WRF AND GLOBAL MODELS WEAKEN THE
SYSTEM. THERE IS ENOUGH UNCERTAINTY...AND OUT OF AN ABUDANCE OF
CAUTION GIVEN THE SATURATED CONDITIONS ACROSS THE AREA...TO EXPAND
THE FLASH FLOOD WATCH EAST THROUGH THE I-35 CORRIDOR.
FRIDAYS FORECAST WILL DEPEND HIGHLY ON WHAT HAPPENS TONIGHT. A
ORGANIZED COMPLEX THAT MAKES IT THROUGH THE CWA MAY STABILIZE
CONDITIONS FOR MUCH OF THE DAY. A WEAKENING COMPLEX...LEAVING
POTENTIAL OUTFLOW BOUNDARY IN AN UNSTABLE ENVIRONMENT...MAY
RESULT IN HIGHER POPS ACROSS THE CENTRAL AND EASTERN CWA FRIDAY.
&&
.LONG TERM (SATURDAY THROUGH THURSDAY)...MODELS ARE COMING INTO
BETTER AGREEMENT WITH MID AND UPPER LEVEL TROUGH AXIS SLIDING
ACROSS THE SOUTHERN PLAINS SATURDAY AND SHARPENING ACROSS
EAST TX/AR/LA SUNDAY INTO MONDAY. THIS WILL SEND A COLD FRONT
INTO THE AREA LATE SATURDAY...AND GOOD CHANCES FOR RAINFALL ACROSS
THE CENTRAL AND EASTERN CWA SATURDAY AND SATURDAY NIGHT. HIGHER
PWATS WILL REMAIN POOLED AHEAD OF THE FRONT AND SLOW MOVEMENT OF
THE FRONT COULD POTENTIALLY LEAD TO SOME LOCAL POCKETS OF HEAVIER
RAINFALL. GFS AND ECMWF GENERALLY IN AGREEMENT BETTER CHANCES OF
RAINFALL SHIFT SOUTH AND EAST WITH THE FRONT SUNDAY...BUT WILL
HAVE TO WATCH THIS CLOSELY IF THE FRONT ENDS UP STALLING WITH A
WEAKER UPPER TROUGH AXIS TO THE EAST.
LOOKS LIKE DRIER CONDITIONS DO DEVELOP MONDAY THROUGH
WEDNESDAY...ALTHOUGH NOT TOTALLY REMOVING POPS ACROSS THE
SOUTHEAST ZONES/COASTAL PRAIRIES WHERE BETTER MOISTURE IS POOLED
AND CLOSER TO THE LOWER HEIGHTS WITH TROUGH AXIS JUST TO THE
EAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 72 85 70 85 67 / 50 40 30 60 50
AUSTIN BERGSTROM INTL AIRPORT 72 84 68 84 65 / 50 50 30 60 50
NEW BRAUNFELS MUNI AIRPORT 73 85 70 85 67 / 50 40 30 60 50
BURNET MUNI AIRPORT 70 83 68 82 65 / 60 40 30 60 50
DEL RIO INTL AIRPORT 69 88 73 86 68 / 70 20 20 50 60
GEORGETOWN MUNI AIRPORT 71 84 69 83 65 / 50 40 30 60 50
HONDO MUNI AIRPORT 71 87 71 85 67 / 60 30 30 50 50
SAN MARCOS MUNI AIRPORT 72 84 70 84 67 / 50 50 30 60 50
LA GRANGE - FAYETTE REGIONAL 74 85 71 85 68 / 40 50 30 60 60
SAN ANTONIO INTL AIRPORT 73 86 71 85 68 / 50 40 30 60 50
STINSON MUNI AIRPORT 73 86 71 85 68 / 50 40 30 50 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH FRIDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...BASTROP...BEXAR...BLANCO...
BURNET...CALDWELL...COMAL...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GUADALUPE...HAYS...KENDALL...KERR...KINNEY...LEE...
LLANO...MAVERICK...MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...
WILLIAMSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...RUNYEN
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
PLEASE SEE THE 18Z AVIATION FORECAST DISCUSSION BELOW.
&&
.AVIATION...
NO SIGNIFICANT CHANGES HAVE BEEN MADE TO THE CURRENT AVIATION
FORECASTS. WE DID INCLUDE SOME TEMPO GROUPS FOR THE I-35 CORRIDOR
SITES FOR TSRA THIS AFTERNOON. A COMPLEX OF SHOWERS AND
THUNDERSTORMS IS EXPECTED TO DEVELOP WEST OF OUR REGION...THEN
SHIFT EAST INTO SOUTH CENTRAL TEXAS OVERNIGHT. WE HAVE MENTIONED
TEMPO GROUPS FOR DRT THIS EVENING AS WELL AS OUR SITES ALONG THE
I-35 CORRIDOR.
&&
.PREV DISCUSSION... /ISSUED 1250 PM CDT THU MAY 28 2015/
UPDATE...UPDATE FOR TORNADO WATCH FOR VAL VERDE COUNTY. CLEARING
IS OCCURRING AND CAP SHOULD CONTINUE TO ERODE. SEVERAL MODELS
INDICATING CONVECTIVE DEVELOPMENT UPSTREAM MAKING IT EAST INTO VAL
VERDE COUNTY. CONDITIONS FAVORABLE FOR LARGE HAIL...DAMAGING WIND
GUSTS AND ISOLATED TORNADOES. A LOCAL EXTENSION EASTWARD COULD BE
REQUIRED...DEPENDENT ON TRENDS. ZFP/GRID UPDATED.
PREV DISCUSSION... /ISSUED 1006 AM CDT THU MAY 28 2015/
DISCUSSION...ISOLATED STREAMER SHOWERS ONGOING THIS MORNING
ACROSS SOUTH-CENTRAL TEXAS. WEAKER CAP AND BREAKS OCCURRING IN
CLOUD COVER TO THE SOUTH ARE ALLOWING FOR DEEPER CONVECTIVE
DEVELOPMENT IN THIS REGION. THIS TREND...WITH AN INCREASE
POSSIBLE IN COVERAGE...IS EXPECTED HEADED INTO THE EARLY
AFTERNOON. FARTHER WEST...CONVECTIVE COMPLEX ACROSS MEXICO HAS
BEEN SHOWING SIGNS OF WEAKENING...AND CLOUD TOPS ARE WARMING ON
SATELLITE...ALBEIT SLOWLY. ELEVATED SHOWERS COULD MAKE IT INTO
VAL VERDE COUNTY SHORTLY. THE 700MB CAP IS STRONGER ON THE 12Z
DRT SOUNDING. HOWEVER...BOTH NAM12 AND GFS FORECAST SOUNDINGS
INDICATE CAP COMPLETELY ERODING BY AFTERNOON...ASSUMING WE GET
BREAKS IN CLOUD COVER. IF THIS HAPPENS...INSTABILITY AND SHEAR
PARAMETERS ARE CONDUCIVE FOR A FEW STRONGER TO SEVERE STORMS
ACROSS THE WESTERN THIRD OF THE CWA.
ATTENTION WILL THEN SHIFT TO UPSTREAM CONVECTIVE DEVELOPMENT THIS
AFTERNOON WITH APPROACH OF SHORTWAVE AND POTENTIAL PROPAGATION
SOUTHEAST INTO THE CWA OVERNIGHT...INTO STRENGTHENING RIO GRANDE
PLAINS LOW LEVEL JET. THERE IS SOME INDICATION IN THE EARLY 12Z
GUIDANCE THAT THE CONCERN FOR ANY CONVECTIVE COMPLEX COULD MAKE IT
FARTHER SOUTH AND EAST THAN ORIGINALLY THINKING...POTENTIALLY
THROUGH THE I-35 CORRIDOR. HOWEVER...WOULD LIKE TO AWAIT FULL
SUITE OF 12Z GUIDANCE BEFORE MAKING ANY INCREASE TO POPS AND
EXPANSION EASTWARD OF THE FLASH FLOOD WATCH FOR TONIGHT. LOOK FOR
THIS TO BE ADDRESSED IN THE AFTERNOON PACKAGE.
PREV DISCUSSION... /ISSUED 423 AM CDT THU MAY 28 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
AT 4 AM...THUNDERSTORMS WERE FORMING SOUTH OF THE BIG BEND IN
MEXICO AND MOVING NORTHEAST TOWARD VAL VERDE COUNTY. THE HRRR WAS
THE WINNING HI RES MODEL IN REGARDS TO THIS FORMATION AND EVOLVES
THIS ACTIVITY INTO A NORTH SOUTH LINE THAT MOVES THROUGH THE
WESTERN ZONES BY 12-13Z. FORECAST SOUNDINGS FOR KDRT SHOW A STOUT
CAP AT 700 MB AND LOTS OVER 100 J/KG OF CIN TO PREVENT SURFACE
BASED PARCELS FROM REALIZING THE ELEVATED INSTABILITY. SHOWERS
THAT HAVE CROSSED THE RIVER SO FAR THIS EVENING HAVE BEEN UNABLE
TO SURVIVE TOO LONG AND THINK THAT WILL BE THE CASE THROUGH THE
MORNING. STILL...WENT WITH CHANCE POPS OUT WEST WHERE THESE STORMS
ARE TRACKING THROUGH 18Z. QPF VALUES SHOULD STAY LOW THOUGH.
MOVING FORWARD...THE FOCUS SHIFTS TO THE DRY LINE OUT WEST AND
MORE UPPER LEVEL SHORTWAVE ENERGY COINCIDING WITH PEAK HEATING AND
MAX INSTABILITY. JUST ABOUT EVERY MODEL EFFICIENTLY INITIATES CONVECTION
BY AROUND 21Z ALONG THE DRY LINE WITH A LARGE HAIL AND DAMAGING
WIND THREAT. THIS THREAT MAY IMPACT WESTERN VAL VERDE THIS
AFTERNOON WHICH IS WHY SPC HAS THIS AREA IN THEIR SLIGHT RISK FOR
TODAY. FORECAST SOUNDINGS NEAR THE DRY LINE SHOW DIFFERENTIAL
HEATING AND INSTABILITY UP AND DOWN THE BOUNDARY...ALSO INVERTED V
PROFILES STAND OUT FOR THE POTENTIAL OF GENERATING HEALTHY
OUTFLOWS...ENOUGH TO PRODUCE FURTHER CONVECTION DOWNSTREAM. ONCE
THIS OCCURS...THESE ISOLATED TO SCATTERED STORMS SHOULD ORGANIZE
INTO A LINEAR SYSTEM AND PUSH SOUTHEAST INTO OUR WESTERN ZONES BY
LATE TONIGHT. THIS IS WHAT WARRANTED THE FLASH FLOOD WATCH FOR
LOCATIONS ON THE ESCARPMENT. RAINFALL TOTALS RANGING FROM HALF AN
INCH TO AN INCH AND HALF ARE POSSIBLE WITH ISOLATED AMOUNTS OF 3
INCHES POSSIBLE. THE ANTECEDENT CONDITIONS ARE THE MAIN DRIVER FOR
THE FLASH FLOOD THREAT. IT GOES WITHOUT SAYING BUT IT WONT TAKE
MUCH RAIN TO CAUSE FLASH FLOODING...EVEN OUT IN THESE WESTERN
AREAS. ADDITIONAL THREATS WITH THIS LINE COULD INCLUDE MARGINALLY
SEVERE HAIL...DAMAGING STRAIGHT LINE WINDS...AND FREQUENT CLOUD TO
GROUND LIGHTNING.
300 MB ANALYSIS SHOWS UPPER LEVEL SUPPORT FALLING OFF DRAMATICALLY
BY 12Z FRIDAY MORNING AND WITH IT...THE LINE OF STORMS. THE BIG
QUESTION WILL BE IF ANY REMNANT BOUNDARIES WILL EXIST FURTHER EAST
FROM THE OVERNIGHT STORM ACTIVITY. IF SO...THOSE LOCATIONS WILL BE
THE FOCUS FOR ISOLATED HEAVY RAIN DEVELOPMENT FRIDAY AFTERNOON.
BEST GUESS AT THE MOMENT WOULD BE THE EASTERN HALF OF THE CWA. DUE
TO THE LOWER CONFIDENCE OF THIS POSSIBILITY...DID NOT INCLUDE THE
FLASH FLOOD WATCH FOR THE I35 CORRIDOR OR EAST. HOWEVER...AN
EXTENSION OR NEW WATCH MAY BE NEEDED IF THIS IS LOOKING MORE
LIKELY.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
OVER THE WEEKEND...THE ECMWF AND GFS DISAGREE ON A COLD FRONT
WHICH MAY IMPACT OUR NORTHERN BORDER BY LATE SATURDAY. IF SO...OUR
NORTHERN ZONES COULD HAVE ANOTHER RAINY WEEKEND AS THE FRONT WOULD
STALL AND WEAK BUT VERY MOIST SOUTHERLY SFC FLOW CREATES PROLONGED
THETA-E CONVERGENCE ALONG IT.
THE ECMWF SEEMS TO WASH OUT THIS BOUNDARY ACROSS NORTH TEXAS AND
BEGINS A TRANSITION PERIOD INTO WEAK FLOW AT ALL LEVELS. THIS
WOULD BE THE PREFERRED OUTCOME AS ONLY WEAK FORCING WOULD RESULT
IN MORE ISOLATED RAIN CHANCES OVER THE WEEKEND.
MOVING INTO NEXT WEEK...A RIDGING PATTERN BEGINS TO SET UP WITH
EARLY WEEK UPPER LEVEL WINDS BEING NORTHERLY. THE DRY LINE
CONTINUES TO BE DRAPED ACROSS THE NM/TX BORDER AND DEEP LAYER
MOISTURE SEEMS TO SUBSIDE. HOWEVER...SFC DEWPOINTS WILL STILL BE
IN THE UPPER 60S AND 70S SO ISOLATED THUNDER WILL BE IN PLAY MOST
AFTERNOONS NEXT WEEK. A VERY WELCOME PATTERN GIVEN THE ENTIRE
MONTH OF MAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 72 85 70 85 68 / 50 40 30 60 50
AUSTIN BERGSTROM INTL AIRPORT 71 84 69 85 66 / 50 50 30 60 50
NEW BRAUNFELS MUNI AIRPORT 72 85 71 85 68 / 50 40 30 60 50
BURNET MUNI AIRPORT 70 83 69 82 66 / 60 40 30 60 50
DEL RIO INTL AIRPORT 70 88 73 86 69 / 70 20 20 50 60
GEORGETOWN MUNI AIRPORT 71 84 70 84 67 / 50 40 30 60 50
HONDO MUNI AIRPORT 71 86 71 86 68 / 60 30 30 50 50
SAN MARCOS MUNI AIRPORT 72 84 70 85 68 / 50 50 30 60 50
LA GRANGE - FAYETTE REGIONAL 74 85 71 85 69 / 40 50 30 60 60
SAN ANTONIO INTL AIRPORT 73 86 72 85 69 / 50 40 30 60 50
STINSON MUNI AIRPORT 73 86 72 86 69 / 50 40 30 50 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH FRIDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...BASTROP...BEXAR...BLANCO...
BURNET...CALDWELL...COMAL...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GUADALUPE...HAYS...KENDALL...KERR...KINNEY...LEE...
LLANO...MAVERICK...MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...
WILLIAMSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...76
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1250 PM CDT THU MAY 28 2015
.UPDATE...UPDATE FOR TORNADO WATCH FOR VAL VERDE COUNTY. CLEARING
IS OCCURRING AND CAP SHOULD CONTINUE TO ERODE. SEVERAL MODELS
INDICATING CONVECTIVE DEVELOPMENT UPSTREAM MAKING IT EAST INTO VAL
VERDE COUNTY. CONDITIONS FAVORABLE FOR LARGE HAIL...DAMAGING WIND
GUSTS AND ISOLATED TORNADOES. A LOCAL EXTENSION EASTWARD COULD BE
REQUIRED...DEPENDENT ON TRENDS. ZFP/GRID UPDATED.
&&
.PREV DISCUSSION... /ISSUED 1006 AM CDT THU MAY 28 2015/
DISCUSSION...ISOLATED STREAMER SHOWERS ONGOING THIS MORNING
ACROSS SOUTH-CENTRAL TEXAS. WEAKER CAP AND BREAKS OCCURRING IN
CLOUD COVER TO THE SOUTH ARE ALLOWING FOR DEEPER CONVECTIVE
DEVELOPMENT IN THIS REGION. THIS TREND...WITH AN INCREASE
POSSIBLE IN COVERAGE...IS EXPECTED HEADED INTO THE EARLY
AFTERNOON. FARTHER WEST...CONVECTIVE COMPLEX ACROSS MEXICO HAS
BEEN SHOWING SIGNS OF WEAKENING...AND CLOUD TOPS ARE WARMING ON
SATELLITE...ALBEIT SLOWLY. ELEVATED SHOWERS COULD MAKE IT INTO
VAL VERDE COUNTY SHORTLY. THE 700MB CAP IS STRONGER ON THE 12Z
DRT SOUNDING. HOWEVER...BOTH NAM12 AND GFS FORECAST SOUNDINGS
INDICATE CAP COMPLETELY ERODING BY AFTERNOON...ASSUMING WE GET
BREAKS IN CLOUD COVER. IF THIS HAPPENS...INSTABILITY AND SHEAR
PARAMETERS ARE CONDUCIVE FOR A FEW STRONGER TO SEVERE STORMS
ACROSS THE WESTERN THIRD OF THE CWA.
ATTENTION WILL THEN SHIFT TO UPSTREAM CONVECTIVE DEVELOPMENT THIS
AFTERNOON WITH APPROACH OF SHORTWAVE AND POTENTIAL PROPAGATION
SOUTHEAST INTO THE CWA OVERNIGHT...INTO STRENGTHENING RIO GRANDE
PLAINS LOW LEVEL JET. THERE IS SOME INDICATION IN THE EARLY 12Z
GUIDANCE THAT THE CONCERN FOR ANY CONVECTIVE COMPLEX COULD MAKE IT
FARTHER SOUTH AND EAST THAN ORIGINALLY THINKING...POTENTIALLY
THROUGH THE I-35 CORRIDOR. HOWEVER...WOULD LIKE TO AWAIT FULL
SUITE OF 12Z GUIDANCE BEFORE MAKING ANY INCREASE TO POPS AND
EXPANSION EASTWARD OF THE FLASH FLOOD WATCH FOR TONIGHT. LOOK FOR
THIS TO BE ADDRESSED IN THE AFTERNOON PACKAGE.
PREV DISCUSSION... /ISSUED 643 AM CDT THU MAY 28 2015/
AVIATION...
NO SIGNIFICANT CHANGES IN THESE TAFS. LOW CIGS THIS MORNING WILL
IMPROVE SOME BY MID-MORNING THEN LIFT TO VFR BY AROUND NOON. THERE
IS A CHANCE FOR SHOWERS AND THUNDERSTORMS TONIGHT AND EARLY
FRIDAY. HAVE NOT INCLUDED ANY CONVECTION IN AUSTIN AND SAN
ANTONIO...AND HAVE PROB30 AT DRT. LATER TAFS SHOULD HAVE A BETTER
FEEL FOR TIMING AND LOCATION OF ANY TSRA/SHRA. CIGS WILL DROP
AGAIN OVERNIGHT.
PREV DISCUSSION... /ISSUED 423 AM CDT THU MAY 28 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
AT 4 AM...THUNDERSTORMS WERE FORMING SOUTH OF THE BIG BEND IN
MEXICO AND MOVING NORTHEAST TOWARD VAL VERDE COUNTY. THE HRRR WAS
THE WINNING HI RES MODEL IN REGARDS TO THIS FORMATION AND EVOLVES
THIS ACTIVITY INTO A NORTH SOUTH LINE THAT MOVES THROUGH THE
WESTERN ZONES BY 12-13Z. FORECAST SOUNDINGS FOR KDRT SHOW A STOUT
CAP AT 700 MB AND LOTS OVER 100 J/KG OF CIN TO PREVENT SURFACE
BASED PARCELS FROM REALIZING THE ELEVATED INSTABILITY. SHOWERS
THAT HAVE CROSSED THE RIVER SO FAR THIS EVENING HAVE BEEN UNABLE
TO SURVIVE TOO LONG AND THINK THAT WILL BE THE CASE THROUGH THE
MORNING. STILL...WENT WITH CHANCE POPS OUT WEST WHERE THESE STORMS
ARE TRACKING THROUGH 18Z. QPF VALUES SHOULD STAY LOW THOUGH.
MOVING FORWARD...THE FOCUS SHIFTS TO THE DRY LINE OUT WEST AND
MORE UPPER LEVEL SHORTWAVE ENERGY COINCIDING WITH PEAK HEATING AND
MAX INSTABILITY. JUST ABOUT EVERY MODEL EFFICIENTLY INITIATES CONVECTION
BY AROUND 21Z ALONG THE DRY LINE WITH A LARGE HAIL AND DAMAGING
WIND THREAT. THIS THREAT MAY IMPACT WESTERN VAL VERDE THIS
AFTERNOON WHICH IS WHY SPC HAS THIS AREA IN THEIR SLIGHT RISK FOR
TODAY. FORECAST SOUNDINGS NEAR THE DRY LINE SHOW DIFFERENTIAL
HEATING AND INSTABILITY UP AND DOWN THE BOUNDARY...ALSO INVERTED V
PROFILES STAND OUT FOR THE POTENTIAL OF GENERATING HEALTHY
OUTFLOWS...ENOUGH TO PRODUCE FURTHER CONVECTION DOWNSTREAM. ONCE
THIS OCCURS...THESE ISOLATED TO SCATTERED STORMS SHOULD ORGANIZE
INTO A LINEAR SYSTEM AND PUSH SOUTHEAST INTO OUR WESTERN ZONES BY
LATE TONIGHT. THIS IS WHAT WARRANTED THE FLASH FLOOD WATCH FOR
LOCATIONS ON THE ESCARPMENT. RAINFALL TOTALS RANGING FROM HALF AN
INCH TO AN INCH AND HALF ARE POSSIBLE WITH ISOLATED AMOUNTS OF 3
INCHES POSSIBLE. THE ANTECEDENT CONDITIONS ARE THE MAIN DRIVER FOR
THE FLASH FLOOD THREAT. IT GOES WITHOUT SAYING BUT IT WONT TAKE
MUCH RAIN TO CAUSE FLASH FLOODING...EVEN OUT IN THESE WESTERN
AREAS. ADDITIONAL THREATS WITH THIS LINE COULD INCLUDE MARGINALLY
SEVERE HAIL...DAMAGING STRAIGHT LINE WINDS...AND FREQUENT CLOUD TO
GROUND LIGHTNING.
300 MB ANALYSIS SHOWS UPPER LEVEL SUPPORT FALLING OFF DRAMATICALLY
BY 12Z FRIDAY MORNING AND WITH IT...THE LINE OF STORMS. THE BIG
QUESTION WILL BE IF ANY REMNANT BOUNDARIES WILL EXIST FURTHER EAST
FROM THE OVERNIGHT STORM ACTIVITY. IF SO...THOSE LOCATIONS WILL BE
THE FOCUS FOR ISOLATED HEAVY RAIN DEVELOPMENT FRIDAY AFTERNOON.
BEST GUESS AT THE MOMENT WOULD BE THE EASTERN HALF OF THE CWA. DUE
TO THE LOWER CONFIDENCE OF THIS POSSIBILITY...DID NOT INCLUDE THE
FLASH FLOOD WATCH FOR THE I35 CORRIDOR OR EAST. HOWEVER...AN
EXTENSION OR NEW WATCH MAY BE NEEDED IF THIS IS LOOKING MORE
LIKELY.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
OVER THE WEEKEND...THE ECMWF AND GFS DISAGREE ON A COLD FRONT
WHICH MAY IMPACT OUR NORTHERN BORDER BY LATE SATURDAY. IF SO...OUR
NORTHERN ZONES COULD HAVE ANOTHER RAINY WEEKEND AS THE FRONT WOULD
STALL AND WEAK BUT VERY MOIST SOUTHERLY SFC FLOW CREATES PROLONGED
THETA-E CONVERGENCE ALONG IT.
THE ECMWF SEEMS TO WASH OUT THIS BOUNDARY ACROSS NORTH TEXAS AND
BEGINS A TRANSITION PERIOD INTO WEAK FLOW AT ALL LEVELS. THIS
WOULD BE THE PREFERRED OUTCOME AS ONLY WEAK FORCING WOULD RESULT
IN MORE ISOLATED RAIN CHANCES OVER THE WEEKEND.
MOVING INTO NEXT WEEK...A RIDGING PATTERN BEGINS TO SET UP WITH
EARLY WEEK UPPER LEVEL WINDS BEING NORTHERLY. THE DRY LINE
CONTINUES TO BE DRAPED ACROSS THE NM/TX BORDER AND DEEP LAYER
MOISTURE SEEMS TO SUBSIDE. HOWEVER...SFC DEWPOINTS WILL STILL BE
IN THE UPPER 60S AND 70S SO ISOLATED THUNDER WILL BE IN PLAY MOST
AFTERNOONS NEXT WEEK. A VERY WELCOME PATTERN GIVEN THE ENTIRE
MONTH OF MAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 88 72 85 70 85 / 40 50 50 30 40
AUSTIN BERGSTROM INTL AIRPORT 88 71 84 69 85 / 40 50 50 20 40
NEW BRAUNFELS MUNI AIRPORT 89 72 85 71 85 / 40 50 40 20 40
BURNET MUNI AIRPORT 86 70 83 69 82 / 40 50 40 30 50
DEL RIO INTL AIRPORT 89 70 88 73 86 / 50 60 20 30 40
GEORGETOWN MUNI AIRPORT 87 71 84 70 84 / 40 50 50 30 50
HONDO MUNI AIRPORT 88 71 86 71 86 / 30 50 40 20 40
SAN MARCOS MUNI AIRPORT 87 72 84 70 85 / 40 50 50 20 40
LA GRANGE - FAYETTE REGIONAL 89 74 85 71 85 / 40 30 50 20 40
SAN ANTONIO INTL AIRPORT 89 73 86 72 85 / 30 50 40 20 40
STINSON MUNI AIRPORT 89 73 86 72 86 / 30 50 40 20 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH FRIDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...EDWARDS...GILLESPIE...KERR...
KINNEY...LLANO...REAL...UVALDE...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...76
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1104 AM CDT THU MAY 28 2015
.UPDATE...
MORNING FORECAST UPDATE.
&&
.DISCUSSION...
SFC ANALYSIS HAS MOISTURE AXIS RUNNING FROM THE COASTAL BEND
THROUGH C TX AND THEN INTO N C TX. AREA RADAR SHOWING SOME SHOWERS
DEVELOPING OVER C TX JUST WEST OF THE BRAZOS VALLEY AND THIS
ACTIVITY MAY DEVELOP EAST THROUGH THE AFTERNOON BASED ON RECENT
HRRR TRENDS. INCREASED CHANCES TO 30 PERCENT FOR THE AFTERNOON
BASED ON THIS. MAX TEMPS IN THE MID/UPPER 80S LOOKS ON TRACK FOR
THE DAY AS WELL.
AFTERNOON FORECAST WILL FOCUS ON THUNDERSTORM CHANCES FRIDAY AND
THEN AGAIN LATE SATURDAY INTO SUNDAY. IT LOOKS LIKE LATE SAT INTO
SUN HAS BETTER SET UP FOR HEAVY RAINFALL WITH FRONTAL BOUNDARY
WORKING INTO THE AREA.
39
&&
.PREV DISCUSSION... /ISSUED 600 AM CDT THU MAY 28 2015/
DISCUSSION...
SEE 12Z AVIATION DISCUSSION.
AVIATION...
VARIABLE SKY CONDITIONS DOMINATE ACROSS SE TX THIS MORNING. MVFR
CIGS PERSIST OVER THE SW ZONES WITH DENSE FOG AND LIFR CIGS AT
KCXO/KUTS. FOG WILL BURN OFF QUICKLY THIS MORNING AND CIGS WILL
ERODE WITH STRONG DAYTIME HEATING. VFR CONDS EXPECTED AREAWIDE BY
16Z. PW VALUES TOP OUT BETWEEN 1.5-1.7 INCHES THIS AFTN SO CAN`T
RULE OUT ISOLATED SHRA/TSRA BUT PROBABILITY LOOKS TOO LOW TO
MENTION IN THE TAF. FCST SOUNDINGS SUPPORT MVFR CIGS DEVELOPING
BETWEEN 08Z-10Z BUT MODELS PERFORMING KINDA POOR AS OF LATE SO NOT
MUCH CONFIDENCE IN CIGS. 43
PREV DISCUSSION... /ISSUED 430 AM CDT THU MAY 28 2015/
DISCUSSION...
A MUCH QUIETER MORNING IS UNDERWAY FOR SOUTHEAST TEXAS THIS
MORNING... WITH DRY CONDITIONS... LIGHT S/SE WINDS... AND
TEMPERATURES IN THE LOW 70S AS OF 3 AM CDT. REGIONAL RADAR MOSAIC
DOES SHOW A THUNDERSTORM COMPLEX LOCATED ALONG A DUMONT...TX TO
HOBART...OK LINE SLOWLY PUSHING EAST-SOUTHEAST EARLY THIS MORNING.
CONTINUING TO MONITOR THIS COMPLEX GIVEN THE REGION/S PRESENT
SENSITIVITY TO ADDITIONAL RAINFALL BUT WITH INFRARED SATELLITE
IMAGERY SHOWING A WARMING TREND IN CLOUD TOP TEMPERATURES... THE
SYSTEM LOOKS TO WEAKEN/DISSIPATE WELL TO THE NORTH OF THE REGION.
FOR THE REMAINDER OF THE DAY... 00Z 500 MB ANALYSIS SHOWED AN
UPPER RIDGE NOSING INTO THE REGION AND THIS WILL HELP LIMIT UPPER
LEVEL SUPPORT FOR STORM DEVELOPMENT. RAP GUIDANCE DOES SHOW A WEAK
SHORTWAVE SKIRTING THE NORTHERN FRINGES OF THIS RIDGE AND
TRANSLATING ACROSS THE FORECAST AREA LATE MORNING AND INTO THE
AFTERNOON. WITH PRECIPITABLE WATER VALUES FORECAST TO RISE BACK
TO NEAR 1.7 INCHES THIS AFTERNOON... CAN/T RULE OUT SOME ISOLATED
TO SCATTERED SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO DEVELOPING
AS TEMPERATURES RISE INTO THE MID TO UPPER 80S TODAY BUT NOT
CONFIDENT ENOUGH TO GO HIGHER THAN 20 POPS FOR THIS AFTERNOON.
ANTICIPATE THIS ACTIVITY TO DIMINISH WITH LOSS OF DAYTIME HEATING.
EARLY MORNING WATER VAPOR IMAGERY SHOWS ANOTHER SHORTWAVE TROUGH
PRESENTLY ROTATING ACROSS ARIZONA/NEW MEXICO AND AS THIS
DISTURBANCE REACHES THE STATE LATE TONIGHT... A SPLIT JET/
DIFFLUENT UPPER PATTERN WILL ESTABLISH ITSELF OVER THE REGION BY
EARLY FRIDAY MORNING. RAIN CHANCES WILL ONCE AGAIN INCREASE FROM
WEST TO EAST WITH LIFT OVERSPREADING THE REGION... WITH TWO
POSSIBLE ROUNDS FOR THE REGION TONIGHT AND TOMORROW. COULD SEE
NORTHWEST TEXAS THUNDERSTORMS TODAY GROW UPSCALE INTO ANOTHER MCS
THAT MAY BE ABLE TO PROPAGATE FAR ENOUGH E/SE TO CLIP WESTERN/
NORTHWESTERN PARTS OF THE REGION OVERNIGHT. ENHANCED LIFT DURING
THE DAY ON FRIDAY WILL ALSO ALLOW FOR ADDITIONAL SHOWERS AND
THUNDERSTORMS TO BLOSSOM ACROSS THE REGION. PRECIPITABLE WATER
VALUES WILL STILL BE HIGH /AROUND THE 75TH PERCENTILE FOR THIS
TIME OF YEAR/... BUT FORECAST SOUNDINGS REMAIN UNSATURATED AND
SIGNALS FOR HEAVY RAIN /HIGH 1000-500 MB RELATIVE HUMIDITIES...
LOW LEVEL MOISTURE TRANSPORT AXIS/ REMAIN DISPLACED FROM EACH
OTHER IN LOCATION. WHILE AN ISOLATED EFFICIENT HEAVY RAIN
PRODUCING STORM CAN/T BE RULED OUT ON FRIDAY... NOT CONFIDENT IN A
WIDESPREAD HEAVY RAIN THREAT AT THE MOMENT. GIVEN HOW SATURATED
THE GROUND IS... HOWEVER... WILL CONTINUE TO MONITOR FOR ANY
POTENTIAL FLOODING THREATS ON FRIDAY.
DIURNALLY DRIVEN CONVECTION IS EXPECTED ON SATURDAY BEFORE A
NORTHERN STREAM SHORTWAVE TROUGH DIVES SOUTH ACROSS THE GREAT
PLAINS SATURDAY INTO SUNDAY... SENDING A LATE SEASON COLD FRONT
TOWARDS THE REGION. THE FRONT WILL REALLY BE MORE OF A WIND
SHIFT... WITH LITTLE CHANGE IN TEMPERATURES BETWEEN SATURDAY AND
SUNDAY /HIGHS IN THE MID 80S/. EXPECT SHOWERS AND THUNDERSTORMS TO
DEVELOP ALONG THE FRONT AS THE FRONT ENTERS THE REGION EARLY
SUNDAY MORNING... STALLING NORTH OF THE UPPER TEXAS COAST. THIS
STALLED BOUNDARY WILL PROVIDE ENOUGH OF A FOCUSING MECHANISM FOR
CONTINUED RAIN CHANCES FOR PARTS OF THE REGION THROUGH MONDAY.
HEADING INTO NEXT WEEK... THE FORECAST BECOMES SOMEWHAT MORE
UNCERTAIN AS MEDIUM RANGE GUIDANCE CUTS OFF ANOTHER PASSING
DISTURBANCE INTO A CLOSED LOW SOMEWHERE OVER THE LOWER MISSISSIPPI
RIVER VALLEY LATE SUNDAY INTO MONDAY. THE ACTUAL PLACEMENT OF THIS
FEATURE WILL DETERMINE RAIN CHANCES HEADING INTO THE MIDDLE OF
NEXT WEEK... WITH A MORE EASTWARD DISPLACEMENT OF THE LOW PLACING
THE REGION IN A MORE SUBSIDENT AND DRIER PATTERN. STILL SEVERAL
DAYS TO REFINE THIS... BUT ONLY HIGHLIGHTING 10-20 POPS IN THE
EXTENDED FOR NOW. OTHERWISE... TEMPERATURES ARE EXPECTED TO REMAIN
NEAR SEASONAL NORMALS IN THE EXTENDED.
HUFFMAN
MARINE...
HIGH PRESSURE OVER THE EASTERN U.S. AND LOWER PRESSURE OVER SE NEW
MEXICO WILL MAINTAIN A LIGHT TO MODERATE ONSHORE FLOW THROUGH
SATURDAY NIGHT. THE GRADIENT WILL TIGHTEN TONIGHT AND AGAIN FRI
NIGHT SO STRONGER NOCTURNAL WINDS EXPECTED WITH A SCEC POSSIBLE
AGAIN TONIGHT. A WEAK COLD FRONT WILL APPROACH SE TX ON SUNDAY. THE
FRONT WILL STALL BEFORE REACHING THE COASTAL WATERS BUT THE WINDS
MAY BRIEFLY BACK TO THE EAST IN ADVANCE OF THE FRONT. A VERY WEAK
PRESSURE GRADIENT WILL PRODUCE LIGHT ONSHORE WINDS NEXT MON/TUES.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 87 73 86 72 83 / 30 20 50 20 40
HOUSTON (IAH) 87 74 85 72 84 / 20 20 50 20 40
GALVESTON (GLS) 86 78 84 76 83 / 20 10 30 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1006 AM CDT THU MAY 28 2015
.DISCUSSION...ISOLATED STREAMER SHOWERS ONGOING THIS MORNING
ACROSS SOUTH-CENTRAL TEXAS. WEAKER CAP AND BREAKS OCCURRING IN
CLOUD COVER TO THE SOUTH ARE ALLOWING FOR DEEPER CONVECTIVE
DEVELOPMENT IN THIS REGION. THIS TREND...WITH AN INCREASE
POSSIBLE IN COVERAGE...IS EXPECTED HEADED INTO THE EARLY
AFTERNOON. FARTHER WEST...CONVECTIVE COMPLEX ACROSS MEXICO HAS
BEEN SHOWING SIGNS OF WEAKENING...AND CLOUD TOPS ARE WARMING ON
SATELLITE...ALBEIT SLOWLY. ELEVATED SHOWERS COULD MAKE IT INTO
VAL VERDE COUNTY SHORTLY. THE 700MB CAP IS STRONGER ON THE 12Z
DRT SOUNDING. HOWEVER...BOTH NAM12 AND GFS FORECAST SOUNDINGS
INDICATE CAP COMPLETELY ERODING BY AFTERNOON...ASSUMING WE GET
BREAKS IN CLOUD COVER. IF THIS HAPPENS...INSTABILITY AND SHEAR
PARAMETERS ARE CONDUCIVE FOR A FEW STRONGER TO SEVERE STORMS
ACROSS THE WESTERN THIRD OF THE CWA.
ATTENTION WILL THEN SHIFT TO UPSTREAM CONVECTIVE DEVELOPMENT THIS
AFTERNOON WITH APPROACH OF SHORTWAVE AND POTENTIAL PROPAGATION
SOUTHEAST INTO THE CWA OVERNIGHT...INTO STRENGTHENING RIO GRANDE
PLAINS LOW LEVEL JET. THERE IS SOME INDICATION IN THE EARLY 12Z
GUIDANCE THAT THE CONCERN FOR ANY CONVECTIVE COMPLEX COULD MAKE IT
FARTHER SOUTH AND EAST THAN ORIGINALLY THINKING...POTENTIALLY
THROUGH THE I-35 CORRIDOR. HOWEVER...WOULD LIKE TO AWAIT FULL
SUITE OF 12Z GUIDANCE BEFORE MAKING ANY INCREASE TO POPS AND
EXPANSION EASTWARD OF THE FLASH FLOOD WATCH FOR TONIGHT. LOOK FOR
THIS TO BE ADDRESSED IN THE AFTERNOON PACKAGE.
&&
.PREV DISCUSSION... /ISSUED 643 AM CDT THU MAY 28 2015/
AVIATION...
NO SIGNIFICANT CHANGES IN THESE TAFS. LOW CIGS THIS MORNING WILL
IMPROVE SOME BY MID-MORNING THEN LIFT TO VFR BY AROUND NOON. THERE
IS A CHANCE FOR SHOWERS AND THUNDERSTORMS TONIGHT AND EARLY
FRIDAY. HAVE NOT INCLUDED ANY CONVECTION IN AUSTIN AND SAN
ANTONIO...AND HAVE PROB30 AT DRT. LATER TAFS SHOULD HAVE A BETTER
FEEL FOR TIMING AND LOCATION OF ANY TSRA/SHRA. CIGS WILL DROP
AGAIN OVERNIGHT.
PREV DISCUSSION... /ISSUED 423 AM CDT THU MAY 28 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
AT 4 AM...THUNDERSTORMS WERE FORMING SOUTH OF THE BIG BEND IN
MEXICO AND MOVING NORTHEAST TOWARD VAL VERDE COUNTY. THE HRRR WAS
THE WINNING HI RES MODEL IN REGARDS TO THIS FORMATION AND EVOLVES
THIS ACTIVITY INTO A NORTH SOUTH LINE THAT MOVES THROUGH THE
WESTERN ZONES BY 12-13Z. FORECAST SOUNDINGS FOR KDRT SHOW A STOUT
CAP AT 700 MB AND LOTS OVER 100 J/KG OF CIN TO PREVENT SURFACE
BASED PARCELS FROM REALIZING THE ELEVATED INSTABILITY. SHOWERS
THAT HAVE CROSSED THE RIVER SO FAR THIS EVENING HAVE BEEN UNABLE
TO SURVIVE TOO LONG AND THINK THAT WILL BE THE CASE THROUGH THE
MORNING. STILL...WENT WITH CHANCE POPS OUT WEST WHERE THESE STORMS
ARE TRACKING THROUGH 18Z. QPF VALUES SHOULD STAY LOW THOUGH.
MOVING FORWARD...THE FOCUS SHIFTS TO THE DRY LINE OUT WEST AND
MORE UPPER LEVEL SHORTWAVE ENERGY COINCIDING WITH PEAK HEATING AND
MAX INSTABILITY. JUST ABOUT EVERY MODEL EFFICIENTLY INITIATES CONVECTION
BY AROUND 21Z ALONG THE DRY LINE WITH A LARGE HAIL AND DAMAGING
WIND THREAT. THIS THREAT MAY IMPACT WESTERN VAL VERDE THIS
AFTERNOON WHICH IS WHY SPC HAS THIS AREA IN THEIR SLIGHT RISK FOR
TODAY. FORECAST SOUNDINGS NEAR THE DRY LINE SHOW DIFFERENTIAL
HEATING AND INSTABILITY UP AND DOWN THE BOUNDARY...ALSO INVERTED V
PROFILES STAND OUT FOR THE POTENTIAL OF GENERATING HEALTHY
OUTFLOWS...ENOUGH TO PRODUCE FURTHER CONVECTION DOWNSTREAM. ONCE
THIS OCCURS...THESE ISOLATED TO SCATTERED STORMS SHOULD ORGANIZE
INTO A LINEAR SYSTEM AND PUSH SOUTHEAST INTO OUR WESTERN ZONES BY
LATE TONIGHT. THIS IS WHAT WARRANTED THE FLASH FLOOD WATCH FOR
LOCATIONS ON THE ESCARPMENT. RAINFALL TOTALS RANGING FROM HALF AN
INCH TO AN INCH AND HALF ARE POSSIBLE WITH ISOLATED AMOUNTS OF 3
INCHES POSSIBLE. THE ANTECEDENT CONDITIONS ARE THE MAIN DRIVER FOR
THE FLASH FLOOD THREAT. IT GOES WITHOUT SAYING BUT IT WONT TAKE
MUCH RAIN TO CAUSE FLASH FLOODING...EVEN OUT IN THESE WESTERN
AREAS. ADDITIONAL THREATS WITH THIS LINE COULD INCLUDE MARGINALLY
SEVERE HAIL...DAMAGING STRAIGHT LINE WINDS...AND FREQUENT CLOUD TO
GROUND LIGHTNING.
300 MB ANALYSIS SHOWS UPPER LEVEL SUPPORT FALLING OFF DRAMATICALLY
BY 12Z FRIDAY MORNING AND WITH IT...THE LINE OF STORMS. THE BIG
QUESTION WILL BE IF ANY REMNANT BOUNDARIES WILL EXIST FURTHER EAST
FROM THE OVERNIGHT STORM ACTIVITY. IF SO...THOSE LOCATIONS WILL BE
THE FOCUS FOR ISOLATED HEAVY RAIN DEVELOPMENT FRIDAY AFTERNOON.
BEST GUESS AT THE MOMENT WOULD BE THE EASTERN HALF OF THE CWA. DUE
TO THE LOWER CONFIDENCE OF THIS POSSIBILITY...DID NOT INCLUDE THE
FLASH FLOOD WATCH FOR THE I35 CORRIDOR OR EAST. HOWEVER...AN
EXTENSION OR NEW WATCH MAY BE NEEDED IF THIS IS LOOKING MORE
LIKELY.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
OVER THE WEEKEND...THE ECMWF AND GFS DISAGREE ON A COLD FRONT
WHICH MAY IMPACT OUR NORTHERN BORDER BY LATE SATURDAY. IF SO...OUR
NORTHERN ZONES COULD HAVE ANOTHER RAINY WEEKEND AS THE FRONT WOULD
STALL AND WEAK BUT VERY MOIST SOUTHERLY SFC FLOW CREATES PROLONGED
THETA-E CONVERGENCE ALONG IT.
THE ECMWF SEEMS TO WASH OUT THIS BOUNDARY ACROSS NORTH TEXAS AND
BEGINS A TRANSITION PERIOD INTO WEAK FLOW AT ALL LEVELS. THIS
WOULD BE THE PREFERRED OUTCOME AS ONLY WEAK FORCING WOULD RESULT
IN MORE ISOLATED RAIN CHANCES OVER THE WEEKEND.
MOVING INTO NEXT WEEK...A RIDGING PATTERN BEGINS TO SET UP WITH
EARLY WEEK UPPER LEVEL WINDS BEING NORTHERLY. THE DRY LINE
CONTINUES TO BE DRAPED ACROSS THE NM/TX BORDER AND DEEP LAYER
MOISTURE SEEMS TO SUBSIDE. HOWEVER...SFC DEWPOINTS WILL STILL BE
IN THE UPPER 60S AND 70S SO ISOLATED THUNDER WILL BE IN PLAY MOST
AFTERNOONS NEXT WEEK. A VERY WELCOME PATTERN GIVEN THE ENTIRE
MONTH OF MAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 88 72 85 70 85 / 30 50 50 30 40
AUSTIN BERGSTROM INTL AIRPORT 88 71 84 69 85 / 20 50 50 20 40
NEW BRAUNFELS MUNI AIRPORT 89 72 85 71 85 / 20 50 40 20 40
BURNET MUNI AIRPORT 86 70 83 69 82 / 30 50 40 30 50
DEL RIO INTL AIRPORT 89 70 88 73 86 / 50 60 20 30 40
GEORGETOWN MUNI AIRPORT 87 71 84 70 84 / 30 50 50 30 50
HONDO MUNI AIRPORT 88 71 86 71 86 / 30 50 40 20 40
SAN MARCOS MUNI AIRPORT 87 72 84 70 85 / 20 50 50 20 40
LA GRANGE - FAYETTE REGIONAL 89 74 85 71 85 / 20 30 50 20 40
SAN ANTONIO INTL AIRPORT 89 73 86 72 85 / 20 50 40 20 40
STINSON MUNI AIRPORT 89 73 86 72 86 / 20 50 40 20 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH FRIDAY MORNING
FOR THE FOLLOWING COUNTIES: BANDERA...EDWARDS...GILLESPIE...KERR...
KINNEY...LLANO...REAL...UVALDE...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...RUNYEN
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
643 AM CDT THU MAY 28 2015
.AVIATION...
NO SIGNIFICANT CHANGES IN THESE TAFS. LOW CIGS THIS MORNING WILL
IMPROVE SOME BY MID-MORNING THEN LIFT TO VFR BY AROUND NOON. THERE
IS A CHANCE FOR SHOWERS AND THUNDERSTORMS TONIGHT AND EARLY
FRIDAY. HAVE NOT INCLUDED ANY CONVECTION IN AUSTIN AND SAN
ANTONIO...AND HAVE PROB30 AT DRT. LATER TAFS SHOULD HAVE A BETTER
FEEL FOR TIMING AND LOCATION OF ANY TSRA/SHRA. CIGS WILL DROP
AGAIN OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 423 AM CDT THU MAY 28 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
AT 4 AM...THUNDERSTORMS WERE FORMING SOUTH OF THE BIG BEND IN
MEXICO AND MOVING NORTHEAST TOWARD VAL VERDE COUNTY. THE HRRR WAS
THE WINNING HI RES MODEL IN REGARDS TO THIS FORMATION AND EVOLVES
THIS ACTIVITY INTO A NORTH SOUTH LINE THAT MOVES THROUGH THE
WESTERN ZONES BY 12-13Z. FORECAST SOUNDINGS FOR KDRT SHOW A STOUT
CAP AT 700 MB AND LOTS OVER 100 J/KG OF CIN TO PREVENT SURFACE
BASED PARCELS FROM REALIZING THE ELEVATED INSTABILITY. SHOWERS
THAT HAVE CROSSED THE RIVER SO FAR THIS EVENING HAVE BEEN UNABLE
TO SURVIVE TOO LONG AND THINK THAT WILL BE THE CASE THROUGH THE
MORNING. STILL...WENT WITH CHANCE POPS OUT WEST WHERE THESE STORMS
ARE TRACKING THROUGH 18Z. QPF VALUES SHOULD STAY LOW THOUGH.
MOVING FORWARD...THE FOCUS SHIFTS TO THE DRY LINE OUT WEST AND
MORE UPPER LEVEL SHORTWAVE ENERGY COINCIDING WITH PEAK HEATING AND
MAX INSTABILITY. JUST ABOUT EVERY MODEL EFFICIENTLY INITIATES CONVECTION
BY AROUND 21Z ALONG THE DRY LINE WITH A LARGE HAIL AND DAMAGING
WIND THREAT. THIS THREAT MAY IMPACT WESTERN VAL VERDE THIS
AFTERNOON WHICH IS WHY SPC HAS THIS AREA IN THEIR SLIGHT RISK FOR
TODAY. FORECAST SOUNDINGS NEAR THE DRY LINE SHOW DIFFERENTIAL
HEATING AND INSTABILITY UP AND DOWN THE BOUNDARY...ALSO INVERTED V
PROFILES STAND OUT FOR THE POTENTIAL OF GENERATING HEALTHY
OUTFLOWS...ENOUGH TO PRODUCE FURTHER CONVECTION DOWNSTREAM. ONCE
THIS OCCURS...THESE ISOLATED TO SCATTERED STORMS SHOULD ORGANIZE
INTO A LINEAR SYSTEM AND PUSH SOUTHEAST INTO OUR WESTERN ZONES BY
LATE TONIGHT. THIS IS WHAT WARRANTED THE FLASH FLOOD WATCH FOR
LOCATIONS ON THE ESCARPMENT. RAINFALL TOTALS RANGING FROM HALF AN
INCH TO AN INCH AND HALF ARE POSSIBLE WITH ISOLATED AMOUNTS OF 3
INCHES POSSIBLE. THE ANTECEDENT CONDITIONS ARE THE MAIN DRIVER FOR
THE FLASH FLOOD THREAT. IT GOES WITHOUT SAYING BUT IT WONT TAKE
MUCH RAIN TO CAUSE FLASH FLOODING...EVEN OUT IN THESE WESTERN
AREAS. ADDITIONAL THREATS WITH THIS LINE COULD INCLUDE MARGINALLY
SEVERE HAIL...DAMAGING STRAIGHT LINE WINDS...AND FREQUENT CLOUD TO
GROUND LIGHTNING.
300 MB ANALYSIS SHOWS UPPER LEVEL SUPPORT FALLING OFF DRAMATICALLY
BY 12Z FRIDAY MORNING AND WITH IT...THE LINE OF STORMS. THE BIG
QUESTION WILL BE IF ANY REMNANT BOUNDARIES WILL EXIST FURTHER EAST
FROM THE OVERNIGHT STORM ACTIVITY. IF SO...THOSE LOCATIONS WILL BE
THE FOCUS FOR ISOLATED HEAVY RAIN DEVELOPMENT FRIDAY AFTERNOON.
BEST GUESS AT THE MOMENT WOULD BE THE EASTERN HALF OF THE CWA. DUE
TO THE LOWER CONFIDENCE OF THIS POSSIBILITY...DID NOT INCLUDE THE
FLASH FLOOD WATCH FOR THE I35 CORRIDOR OR EAST. HOWEVER...AN
EXTENSION OR NEW WATCH MAY BE NEEDED IF THIS IS LOOKING MORE
LIKELY.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
OVER THE WEEKEND...THE ECMWF AND GFS DISAGREE ON A COLD FRONT
WHICH MAY IMPACT OUR NORTHERN BORDER BY LATE SATURDAY. IF SO...OUR
NORTHERN ZONES COULD HAVE ANOTHER RAINY WEEKEND AS THE FRONT WOULD
STALL AND WEAK BUT VERY MOIST SOUTHERLY SFC FLOW CREATES PROLONGED
THETA-E CONVERGENCE ALONG IT.
THE ECMWF SEEMS TO WASH OUT THIS BOUNDARY ACROSS NORTH TEXAS AND
BEGINS A TRANSITION PERIOD INTO WEAK FLOW AT ALL LEVELS. THIS
WOULD BE THE PREFERRED OUTCOME AS ONLY WEAK FORCING WOULD RESULT
IN MORE ISOLATED RAIN CHANCES OVER THE WEEKEND.
MOVING INTO NEXT WEEK...A RIDGING PATTERN BEGINS TO SET UP WITH
EARLY WEEK UPPER LEVEL WINDS BEING NORTHERLY. THE DRY LINE
CONTINUES TO BE DRAPED ACROSS THE NM/TX BORDER AND DEEP LAYER
MOISTURE SEEMS TO SUBSIDE. HOWEVER...SFC DEWPOINTS WILL STILL BE
IN THE UPPER 60S AND 70S SO ISOLATED THUNDER WILL BE IN PLAY MOST
AFTERNOONS NEXT WEEK. A VERY WELCOME PATTERN GIVEN THE ENTIRE
MONTH OF MAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 88 72 85 70 85 / 30 50 50 30 40
AUSTIN BERGSTROM INTL AIRPORT 88 71 84 69 85 / 20 50 50 20 40
NEW BRAUNFELS MUNI AIRPORT 89 72 85 71 85 / 20 50 40 20 40
BURNET MUNI AIRPORT 86 70 83 69 82 / 30 50 40 30 50
DEL RIO INTL AIRPORT 89 70 88 73 86 / 50 60 20 30 40
GEORGETOWN MUNI AIRPORT 87 71 84 70 84 / 30 50 50 30 50
HONDO MUNI AIRPORT 88 71 86 71 86 / 30 50 40 20 40
SAN MARCOS MUNI AIRPORT 87 72 84 70 85 / 20 50 50 20 40
LA GRANGE - FAYETTE REGIONAL 89 74 85 71 85 / 20 30 50 20 40
SAN ANTONIO INTL AIRPORT 89 73 86 72 85 / 20 50 40 20 40
STINSON MUNI AIRPORT 89 73 86 72 86 / 20 50 40 20 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR THE
FOLLOWING COUNTIES: BANDERA...EDWARDS...GILLESPIE...KERR...KINNEY...
LLANO...REAL...UVALDE...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...TB3
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
600 AM CDT THU MAY 28 2015
.DISCUSSION...
SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...
VARIABLE SKY CONDITIONS DOMINATE ACROSS SE TX THIS MORNING. MVFR
CIGS PERSIST OVER THE SW ZONES WITH DENSE FOG AND LIFR CIGS AT
KCXO/KUTS. FOG WILL BURN OFF QUICKLY THIS MORNING AND CIGS WILL
ERODE WITH STRONG DAYTIME HEATING. VFR CONDS EXPECTED AREAWIDE BY
16Z. PW VALUES TOP OUT BETWEEN 1.5-1.7 INCHES THIS AFTN SO CAN`T
RULE OUT ISOLATED SHRA/TSRA BUT PROBABILITY LOOKS TOO LOW TO
MENTION IN THE TAF. FCST SOUNDINGS SUPPORT MVFR CIGS DEVELOPING
BETWEEN 08Z-10Z BUT MODELS PERFORMING KINDA POOR AS OF LATE SO NOT
MUCH CONFIDENCE IN CIGS. 43
&&
.PREV DISCUSSION... /ISSUED 430 AM CDT THU MAY 28 2015/
DISCUSSION...
A MUCH QUIETER MORNING IS UNDERWAY FOR SOUTHEAST TEXAS THIS
MORNING... WITH DRY CONDITIONS... LIGHT S/SE WINDS... AND
TEMPERATURES IN THE LOW 70S AS OF 3 AM CDT. REGIONAL RADAR MOSAIC
DOES SHOW A THUNDERSTORM COMPLEX LOCATED ALONG A DUMONT...TX TO
HOBART...OK LINE SLOWLY PUSHING EAST-SOUTHEAST EARLY THIS MORNING.
CONTINUING TO MONITOR THIS COMPLEX GIVEN THE REGION/S PRESENT
SENSITIVITY TO ADDITIONAL RAINFALL BUT WITH INFRARED SATELLITE
IMAGERY SHOWING A WARMING TREND IN CLOUD TOP TEMPERATURES... THE
SYSTEM LOOKS TO WEAKEN/DISSIPATE WELL TO THE NORTH OF THE REGION.
FOR THE REMAINDER OF THE DAY... 00Z 500 MB ANALYSIS SHOWED AN
UPPER RIDGE NOSING INTO THE REGION AND THIS WILL HELP LIMIT UPPER
LEVEL SUPPORT FOR STORM DEVELOPMENT. RAP GUIDANCE DOES SHOW A WEAK
SHORTWAVE SKIRTING THE NORTHERN FRINGES OF THIS RIDGE AND
TRANSLATING ACROSS THE FORECAST AREA LATE MORNING AND INTO THE
AFTERNOON. WITH PRECIPITABLE WATER VALUES FORECAST TO RISE BACK
TO NEAR 1.7 INCHES THIS AFTERNOON... CAN/T RULE OUT SOME ISOLATED
TO SCATTERED SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO DEVELOPING
AS TEMPERATURES RISE INTO THE MID TO UPPER 80S TODAY BUT NOT
CONFIDENT ENOUGH TO GO HIGHER THAN 20 POPS FOR THIS AFTERNOON.
ANTICIPATE THIS ACTIVITY TO DIMINISH WITH LOSS OF DAYTIME HEATING.
EARLY MORNING WATER VAPOR IMAGERY SHOWS ANOTHER SHORTWAVE TROUGH
PRESENTLY ROTATING ACROSS ARIZONA/NEW MEXICO AND AS THIS
DISTURBANCE REACHES THE STATE LATE TONIGHT... A SPLIT JET/
DIFFLUENT UPPER PATTERN WILL ESTABLISH ITSELF OVER THE REGION BY
EARLY FRIDAY MORNING. RAIN CHANCES WILL ONCE AGAIN INCREASE FROM
WEST TO EAST WITH LIFT OVERSPREADING THE REGION... WITH TWO
POSSIBLE ROUNDS FOR THE REGION TONIGHT AND TOMORROW. COULD SEE
NORTHWEST TEXAS THUNDERSTORMS TODAY GROW UPSCALE INTO ANOTHER MCS
THAT MAY BE ABLE TO PROPAGATE FAR ENOUGH E/SE TO CLIP WESTERN/
NORTHWESTERN PARTS OF THE REGION OVERNIGHT. ENHANCED LIFT DURING
THE DAY ON FRIDAY WILL ALSO ALLOW FOR ADDITIONAL SHOWERS AND
THUNDERSTORMS TO BLOSSOM ACROSS THE REGION. PRECIPITABLE WATER
VALUES WILL STILL BE HIGH /AROUND THE 75TH PERCENTILE FOR THIS
TIME OF YEAR/... BUT FORECAST SOUNDINGS REMAIN UNSATURATED AND
SIGNALS FOR HEAVY RAIN /HIGH 1000-500 MB RELATIVE HUMIDITIES...
LOW LEVEL MOISTURE TRANSPORT AXIS/ REMAIN DISPLACED FROM EACH
OTHER IN LOCATION. WHILE AN ISOLATED EFFICIENT HEAVY RAIN
PRODUCING STORM CAN/T BE RULED OUT ON FRIDAY... NOT CONFIDENT IN A
WIDESPREAD HEAVY RAIN THREAT AT THE MOMENT. GIVEN HOW SATURATED
THE GROUND IS... HOWEVER... WILL CONTINUE TO MONITOR FOR ANY
POTENTIAL FLOODING THREATS ON FRIDAY.
DIURNALLY DRIVEN CONVECTION IS EXPECTED ON SATURDAY BEFORE A
NORTHERN STREAM SHORTWAVE TROUGH DIVES SOUTH ACROSS THE GREAT
PLAINS SATURDAY INTO SUNDAY... SENDING A LATE SEASON COLD FRONT
TOWARDS THE REGION. THE FRONT WILL REALLY BE MORE OF A WIND
SHIFT... WITH LITTLE CHANGE IN TEMPERATURES BETWEEN SATURDAY AND
SUNDAY /HIGHS IN THE MID 80S/. EXPECT SHOWERS AND THUNDERSTORMS TO
DEVELOP ALONG THE FRONT AS THE FRONT ENTERS THE REGION EARLY
SUNDAY MORNING... STALLING NORTH OF THE UPPER TEXAS COAST. THIS
STALLED BOUNDARY WILL PROVIDE ENOUGH OF A FOCUSING MECHANISM FOR
CONTINUED RAIN CHANCES FOR PARTS OF THE REGION THROUGH MONDAY.
HEADING INTO NEXT WEEK... THE FORECAST BECOMES SOMEWHAT MORE
UNCERTAIN AS MEDIUM RANGE GUIDANCE CUTS OFF ANOTHER PASSING
DISTURBANCE INTO A CLOSED LOW SOMEWHERE OVER THE LOWER MISSISSIPPI
RIVER VALLEY LATE SUNDAY INTO MONDAY. THE ACTUAL PLACEMENT OF THIS
FEATURE WILL DETERMINE RAIN CHANCES HEADING INTO THE MIDDLE OF
NEXT WEEK... WITH A MORE EASTWARD DISPLACEMENT OF THE LOW PLACING
THE REGION IN A MORE SUBSIDENT AND DRIER PATTERN. STILL SEVERAL
DAYS TO REFINE THIS... BUT ONLY HIGHLIGHTING 10-20 POPS IN THE
EXTENDED FOR NOW. OTHERWISE... TEMPERATURES ARE EXPECTED TO REMAIN
NEAR SEASONAL NORMALS IN THE EXTENDED.
HUFFMAN
MARINE...
HIGH PRESSURE OVER THE EASTERN U.S. AND LOWER PRESSURE OVER SE NEW
MEXICO WILL MAINTAIN A LIGHT TO MODERATE ONSHORE FLOW THROUGH
SATURDAY NIGHT. THE GRADIENT WILL TIGHTEN TONIGHT AND AGAIN FRI
NIGHT SO STRONGER NOCTURNAL WINDS EXPECTED WITH A SCEC POSSIBLE
AGAIN TONIGHT. A WEAK COLD FRONT WILL APPROACH SE TX ON SUNDAY. THE
FRONT WILL STALL BEFORE REACHING THE COASTAL WATERS BUT THE WINDS
MAY BRIEFLY BACK TO THE EAST IN ADVANCE OF THE FRONT. A VERY WEAK
PRESSURE GRADIENT WILL PRODUCE LIGHT ONSHORE WINDS NEXT MON/TUES.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 87 73 86 72 83 / 20 20 50 20 40
HOUSTON (IAH) 87 74 85 72 84 / 20 20 50 20 40
GALVESTON (GLS) 86 78 84 76 83 / 20 10 30 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
359 AM MDT THU MAY 28 2015
.SYNOPSIS...
TROUGH ALOFT CURRENTLY PASSING THROUGH NEW MEXICO WILL ALLOW HIGHER
CLOUDS TO DIMINISH WITH PLENTY OF SUNSHINE THIS AFTERNOON. THE
SUNSHINE SHOULD CONTINUE FRIDAY WITH TEMPERATURES BOTH DAYS ABOVE
NORMAL. A COOL FRONT WILL PUSH WEST THROUGH MOST OF THE BORDERLAND
SATURDAY...GREATLY INCREASING LOW LEVEL MOISTURE AND FUELING
SCATTERED THUNDERSTORMS SATURDAY AFTERNOON AND NIGHT. A FEW OF THESE
STORMS COULD BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS. UPPER
LEVEL RIDGE MOVES OVER THE AREA SUNDAY AND PERSISTS THROUGH TUESDAY.
LOW LEVEL MOISTURE WILL PERSIST SO SOME THUNDERSTORMS ARE STILL
POSSIBLE EACH DAY. THE RIDGE HOWEVER WILL LIMIT BOTH THE COVERAGE
AND STRENGTH OF THE STORMS.
&&
.DISCUSSION...
UPPER LOW CURRENTLY OVER SOUTH CENTRAL NEW MEXICO AND CONTINUING TO
WEAKEN AS IT LIFTS OUT TO THE NORTHEAST. STILL HIGH DEWPOINTS (45-55
DEG) FROM EL PASO EASTWARD..THOUGH EXITING TROUGH SHOULD HELP FLUSH
THIS. HRRR SHOWS THIS PROCESS BEGINNING AROUND 14Z AND COMPLETING BY
18Z. IF THIS FLUSHING IS DELAYED A FEW HOURS...LATE MORNING HEATING
COULD PROVIDE A FEW THUNDERSTORMS. WILL HAVE TO WATCH FOR THAT.
OTHERWISE MOSTLY DRY WEST FLOW ALOFT TODAY AND FRIDAY. MODELS SHOW
WEAK DISTURBANCE ALOFT PASSING THROUGH FRIDAY...BUT ONLY NAM SHOWS
QPF NEAR THE NORTHERN ZONES SO WILL LEAVE OUT FOR NOW.
SATURDAY BEGINS A TRANSITION TO MORE HUMID UNSETTLED WEATHER. UPPER
RIDGE BEGINNING TO BUILD OVER THE WEST COAST AND GREAT BASIN WILL
INCREASE NORTHWEST FLOW WITH STRONG DISTURBANCE DROPPING DOWN OVER
THE SOUTHERN PLAINS FRIDAY NIGHT AND SATURDAY. THIS WILL PUSH A BACK
DOOR COOL FRONT AND SIGNIFICANT MOISTURE ADVECTION WEST THROUGH ALL
OF THE CWA. FRONT SHOULD REACH ARIZONA BORDER SATURDAY NIGHT. GFS
STILL MORE BULLISH WITH QPF THAN NAM...DESPITE VERY SIMILAR FEATURES
BETWEEN THE TWO MODELS. LI`S OF -2 TO -3 AND MUCAPES OF 1000-2000
J/KG INDICATE STRONG INSTABILITY AND GOOD SHEAR PROFILES...ALL
COMBINE TO CREATE POTENTIAL FOR SEVERE THUNDERSTORMS. PROG SOUNDINGS
HAVE SHOWN DOWNWARD TREND FOR WBZ LEVELS LAST COUPLE OF DAYS ALSO.
LATEST WBZ LEVEL FOR EL PASO IS NOW 12,500 FT MSL SATURDAY AFTERNOON
AND EVENING. LARGE HAIL AND DAMAGING WINDS OF 55-65 MPH ARE
POSSIBLE.
UPPER RIDGE FINALLY MOVES OVER THE AREA SUNDAY INTO TUESDAY. THIS
WILL GIVE US A TYPICAL SUMMER PATTERN OF MODERATE TO STRONG CAPPING
ALOFT WITH GOOD LOW LEVEL MOISTURE WHICH CAN`T BE FLUSHED OUT. THE
RESULT IS USUALLY MORE ISOLATED STORMS WITH LESS STRENGTH...AND
OFTEN FAVORED OR LIMITED TO MOUNTAIN AREAS. SO SUNDAY THROUGH
TUESDAY WILL SEE ISOLATED THUNDERSTORMS. GFS STILL SHOWING A BIT OF
TROPICAL MOISTURE FROM ANDRES MOVING NORTH OVER THE AREA WEDNESDAY
AND THURSDAY WHILE ECMWF BACKING OFF THIS SOLUTION. WILL KEEP LOW
POPS IN BOTH DAYS JUST IN CASE...BUT ECMWF PROBABLY CLOSER TO
REALITY GIVEN THE TIME OF THE YEAR AND THE POSITION OF THE BLOCKING
RIDGE.
&&
.AVIATION...VALID 28/12Z-29/12Z.
CLEAR/VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WEST WINDS 10-15
KTS AFTER 17Z.
&&
.FIRE WEATHER...
DRY AND WARM WEATHER WILL CONTINUE THROUGH SATURDAY. MIN RH`S BOTH
DAYS RANGING FROM 7-17%. SATURDAY AND SATURDAY NIGHT A BACKDOOR COLD
FRONT ACCOMPANIED BY A STRONG SURGE OF MOISTURE AND AN UNSTABLE
ATMOSPHERE WILL GENERATE THUNDERSTORMS ACROSS MUCH OF THE AREA. SOME
OF THESE STORMS COULD BE STRONG TO SEVERE WITH LARGE HAIL AND STRONG
WINDS. AREAS OF LOCALIZED HEAVY RAINFALL COULD OCCUR RESULTING IN
POSSIBLE FLOODING. RESIDUAL MOISTURE WILL REMAIN IN PLACE SUNDAY
THROUGH TUESDAY BUT UPPER RIDGE BECOMES PLANTED FIRMLY IN PLACE.
THIS WILL HAVE A CAPPING AFFECT ON THE ATMOSPHERE...LIMITING
THUNDERSTORM ACTIVITY TO ISOLATED COVERAGE AND ALSO LIKELY
ELIMINATING THE STRONG/SEVERE POTENTIAL. MIN RH`S WILL RISE
DRAMATICALLY SATURDAY AND BEYOND.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 93 64 95 65 92 / 0 0 0 0 10
SIERRA BLANCA 90 58 92 60 85 / 0 0 0 0 20
LAS CRUCES 91 56 94 58 90 / 0 0 0 0 10
ALAMOGORDO 92 58 95 59 88 / 0 0 0 0 20
CLOUDCROFT 70 43 72 41 68 / 0 0 0 0 30
TRUTH OR CONSEQUENCES 90 58 93 57 88 / 0 0 0 0 10
SILVER CITY 82 50 84 51 83 / 0 0 0 0 0
DEMING 92 53 95 56 92 / 0 0 0 0 0
LORDSBURG 90 54 94 57 92 / 0 0 0 0 0
WEST EL PASO METRO 93 64 94 65 92 / 0 0 0 0 10
DELL CITY 92 58 94 58 86 / 0 0 0 0 20
FORT HANCOCK 93 60 95 63 91 / 0 0 0 0 20
LOMA LINDA 87 58 88 57 83 / 0 0 0 0 20
FABENS 93 60 95 61 92 / 0 0 0 0 10
SANTA TERESA 92 58 94 62 91 / 0 0 0 0 10
WHITE SANDS HQ 91 60 95 62 89 / 0 0 0 0 10
JORNADA RANGE 92 55 95 56 89 / 0 0 0 0 10
HATCH 92 56 94 57 91 / 0 0 0 0 10
COLUMBUS 91 58 94 61 91 / 0 0 0 0 0
OROGRANDE 92 61 95 61 88 / 0 0 0 0 20
MAYHILL 78 49 80 47 73 / 0 0 0 0 30
MESCALERO 79 46 81 45 76 / 0 0 0 0 30
TIMBERON 78 48 79 46 76 / 0 0 0 0 30
WINSTON 82 46 83 49 81 / 0 0 0 0 10
HILLSBORO 89 53 91 54 88 / 0 0 0 0 10
SPACEPORT 92 54 96 54 90 / 0 0 0 0 10
LAKE ROBERTS 82 45 84 49 84 / 0 0 0 0 10
HURLEY 84 50 87 52 85 / 0 0 0 0 0
CLIFF 89 42 90 41 88 / 0 0 0 0 0
MULE CREEK 86 38 86 40 87 / 0 0 0 0 0
FAYWOOD 86 52 88 54 85 / 0 0 0 0 0
ANIMAS 91 54 94 58 93 / 0 0 0 0 0
HACHITA 92 52 95 56 93 / 0 0 0 0 0
ANTELOPE WELLS 91 52 94 56 93 / 0 0 0 0 0
CLOVERDALE 85 51 88 54 89 / 0 0 0 0 0
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
HEFNER
AREA FORECAST DISCUSSION...CORRECTED
NWS HOUSTON/GALVESTON TX
430 AM CDT THU MAY 28 2015
.DISCUSSION...
A MUCH QUIETER MORNING IS UNDERWAY FOR SOUTHEAST TEXAS THIS
MORNING... WITH DRY CONDITIONS... LIGHT S/SE WINDS... AND
TEMPERATURES IN THE LOW 70S AS OF 3 AM CDT. REGIONAL RADAR MOSAIC
DOES SHOW A THUNDERSTORM COMPLEX LOCATED ALONG A DUMONT...TX TO
HOBART...OK LINE SLOWLY PUSHING EAST-SOUTHEAST EARLY THIS MORNING.
CONTINUING TO MONITOR THIS COMPLEX GIVEN THE REGION/S PRESENT
SENSITIVITY TO ADDITIONAL RAINFALL BUT WITH INFRARED SATELLITE
IMAGERY SHOWING A WARMING TREND IN CLOUD TOP TEMPERATURES... THE
SYSTEM LOOKS TO WEAKEN/DISSIPATE WELL TO THE NORTH OF THE REGION.
FOR THE REMAINDER OF THE DAY... 00Z 500 MB ANALYSIS SHOWED AN
UPPER RIDGE NOSING INTO THE REGION AND THIS WILL HELP LIMIT UPPER
LEVEL SUPPORT FOR STORM DEVELOPMENT. RAP GUIDANCE DOES SHOW A WEAK
SHORTWAVE SKIRTING THE NORTHERN FRINGES OF THIS RIDGE AND
TRANSLATING ACROSS THE FORECAST AREA LATE MORNING AND INTO THE
AFTERNOON. WITH PRECIPITABLE WATER VALUES FORECAST TO RISE BACK
TO NEAR 1.7 INCHES THIS AFTERNOON... CAN/T RULE OUT SOME ISOLATED
TO SCATTERED SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO DEVELOPING
AS TEMPERATURES RISE INTO THE MID TO UPPER 80S TODAY BUT NOT
CONFIDENT ENOUGH TO GO HIGHER THAN 20 POPS FOR THIS AFTERNOON.
ANTICIPATE THIS ACTIVITY TO DIMINISH WITH LOSS OF DAYTIME HEATING.
EARLY MORNING WATER VAPOR IMAGERY SHOWS ANOTHER SHORTWAVE TROUGH
PRESENTLY ROTATING ACROSS ARIZONA/NEW MEXICO AND AS THIS
DISTURBANCE REACHES THE STATE LATE TONIGHT... A SPLIT JET/
DIFFLUENT UPPER PATTERN WILL ESTABLISH ITSELF OVER THE REGION BY
EARLY FRIDAY MORNING. RAIN CHANCES WILL ONCE AGAIN INCREASE FROM
WEST TO EAST WITH LIFT OVERSPREADING THE REGION... WITH TWO
POSSIBLE ROUNDS FOR THE REGION TONIGHT AND TOMORROW. COULD SEE
NORTHWEST TEXAS THUNDERSTORMS TODAY GROW UPSCALE INTO ANOTHER MCS
THAT MAY BE ABLE TO PROPAGATE FAR ENOUGH E/SE TO CLIP WESTERN/
NORTHWESTERN PARTS OF THE REGION OVERNIGHT. ENHANCED LIFT DURING
THE DAY ON FRIDAY WILL ALSO ALLOW FOR ADDITIONAL SHOWERS AND
THUNDERSTORMS TO BLOSSOM ACROSS THE REGION. PRECIPITABLE WATER
VALUES WILL STILL BE HIGH /AROUND THE 75TH PERCENTILE FOR THIS
TIME OF YEAR/... BUT FORECAST SOUNDINGS REMAIN UNSATURATED AND
SIGNALS FOR HEAVY RAIN /HIGH 1000-500 MB RELATIVE HUMIDITIES...
LOW LEVEL MOISTURE TRANSPORT AXIS/ REMAIN DISPLACED FROM EACH
OTHER IN LOCATION. WHILE AN ISOLATED EFFICIENT HEAVY RAIN
PRODUCING STORM CAN/T BE RULED OUT ON FRIDAY... NOT CONFIDENT IN A
WIDESPREAD HEAVY RAIN THREAT AT THE MOMENT. GIVEN HOW SATURATED
THE GROUND IS... HOWEVER... WILL CONTINUE TO MONITOR FOR ANY
POTENTIAL FLOODING THREATS ON FRIDAY.
DIURNALLY DRIVEN CONVECTION IS EXPECTED ON SATURDAY BEFORE A
NORTHERN STREAM SHORTWAVE TROUGH DIVES SOUTH ACROSS THE GREAT
PLAINS SATURDAY INTO SUNDAY... SENDING A LATE SEASON COLD FRONT
TOWARDS THE REGION. THE FRONT WILL REALLY BE MORE OF A WIND
SHIFT... WITH LITTLE CHANGE IN TEMPERATURES BETWEEN SATURDAY AND
SUNDAY /HIGHS IN THE MID 80S/. EXPECT SHOWERS AND THUNDERSTORMS TO
DEVELOP ALONG THE FRONT AS THE FRONT ENTERS THE REGION EARLY
SUNDAY MORNING... STALLING NORTH OF THE UPPER TEXAS COAST. THIS
STALLED BOUNDARY WILL PROVIDE ENOUGH OF A FOCUSING MECHANISM FOR
CONTINUED RAIN CHANCES FOR PARTS OF THE REGION THROUGH MONDAY.
HEADING INTO NEXT WEEK... THE FORECAST BECOMES SOMEWHAT MORE
UNCERTAIN AS MEDIUM RANGE GUIDANCE CUTS OFF ANOTHER PASSING
DISTURBANCE INTO A CLOSED LOW SOMEWHERE OVER THE LOWER MISSISSIPPI
RIVER VALLEY LATE SUNDAY INTO MONDAY. THE ACTUAL PLACEMENT OF THIS
FEATURE WILL DETERMINE RAIN CHANCES HEADING INTO THE MIDDLE OF
NEXT WEEK... WITH A MORE EASTWARD DISPLACEMENT OF THE LOW PLACING
THE REGION IN A MORE SUBSIDENT AND DRIER PATTERN. STILL SEVERAL
DAYS TO REFINE THIS... BUT ONLY HIGHLIGHTING 10-20 POPS IN THE
EXTENDED FOR NOW. OTHERWISE... TEMPERATURES ARE EXPECTED TO REMAIN
NEAR SEASONAL NORMALS IN THE EXTENDED.
HUFFMAN
&&
.MARINE...
HIGH PRESSURE OVER THE EASTERN U.S. AND LOWER PRESSURE OVER SE NEW
MEXICO WILL MAINTAIN A LIGHT TO MODERATE ONSHORE FLOW THROUGH
SATURDAY NIGHT. THE GRADIENT WILL TIGHTEN TONIGHT AND AGAIN FRI
NIGHT SO STRONGER NOCTURNAL WINDS EXPECTED WITH A SCEC POSSIBLE
AGAIN TONIGHT. A WEAK COLD FRONT WILL APPROACH SE TX ON SUNDAY. THE
FRONT WILL STALL BEFORE REACHING THE COASTAL WATERS BUT THE WINDS
MAY BRIEFLY BACK TO THE EAST IN ADVANCE OF THE FRONT. A VERY WEAK
PRESSURE GRADIENT WILL PRODUCE LIGHT ONSHORE WINDS NEXT MON/TUES.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 87 73 86 72 83 / 20 20 50 20 40
HOUSTON (IAH) 87 74 85 72 84 / 20 20 50 20 40
GALVESTON (GLS) 86 78 84 76 83 / 20 10 30 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
423 AM CDT THU MAY 28 2015
.SHORT TERM (TODAY THROUGH FRIDAY)...
AT 4 AM...THUNDERSTORMS WERE FORMING SOUTH OF THE BIG BEND IN
MEXICO AND MOVING NORTHEAST TOWARD VAL VERDE COUNTY. THE HRRR WAS
THE WINNING HI RES MODEL IN REGARDS TO THIS FORMATION AND EVOLVES
THIS ACTIVITY INTO A NORTH SOUTH LINE THAT MOVES THROUGH THE
WESTERN ZONES BY 12-13Z. FORECAST SOUNDINGS FOR KDRT SHOW A STOUT
CAP AT 700 MB AND LOTS OVER 100 J/KG OF CIN TO PREVENT SURFACE
BASED PARCELS FROM REALIZING THE ELEVATED INSTABILITY. SHOWERS
THAT HAVE CROSSED THE RIVER SO FAR THIS EVENING HAVE BEEN UNABLE
TO SURVIVE TOO LONG AND THINK THAT WILL BE THE CASE THROUGH THE
MORNING. STILL...WENT WITH CHANCE POPS OUT WEST WHERE THESE STORMS
ARE TRACKING THROUGH 18Z. QPF VALUES SHOULD STAY LOW THOUGH.
MOVING FORWARD...THE FOCUS SHIFTS TO THE DRY LINE OUT WEST AND
MORE UPPER LEVEL SHORTWAVE ENERGY COINCIDING WITH PEAK HEATING AND
MAX INSTABILITY. JUST ABOUT EVERY MODEL EFFICIENTLY INITIATESCONVECTION
BY AROUND 21Z ALONG THE DRY LINE WITH A LARGE HAIL AND DAMAGING
WIND THREAT. THIS THREAT MAY IMPACT WESTERN VAL VERDE THIS
AFTERNOON WHICH IS WHY SPC HAS THIS AREA IN THEIR SLIGHT RISK FOR
TODAY. FORECAST SOUNDINGS NEAR THE DRY LINE SHOW DIFFERENTIAL
HEATING AND INSTABILITY UP AND DOWN THE BOUNDARY...ALSO INVERTED V
PROFILES STAND OUT FOR THE POTENTIAL OF GENERATING HEALTHY
OUTFLOWS...ENOUGH TO PRODUCE FURTHER CONVECTION DOWNSTREAM. ONCE
THIS OCCURS...THESE ISOLATED TO SCATTERED STORMS SHOULD ORGANIZE
INTO A LINEAR SYSTEM AND PUSH SOUTHEAST INTO OUR WESTERN ZONES BY
LATE TONIGHT. THIS IS WHAT WARRANTED THE FLASH FLOOD WATCH FOR
LOCATIONS ON THE ESCARPMENT. RAINFALL TOTALS RANGING FROM HALF AN
INCH TO AN INCH AND HALF ARE POSSIBLE WITH ISOLATED AMOUNTS OF 3
INCHES POSSIBLE. THE ANTECEDENT CONDITIONS ARE THE MAIN DRIVER FOR
THE FLASH FLOOD THREAT. IT GOES WITHOUT SAYING BUT IT WONT TAKE
MUCH RAIN TO CAUSE FLASH FLOODING...EVEN OUT IN THESE WESTERN
AREAS. ADDITIONAL THREATS WITH THIS LINE COULD INCLUDE MARGINALLY
SEVERE HAIL...DAMAGING STRAIGHT LINE WINDS...AND FREQUENT CLOUD TO
GROUND LIGHTNING.
300 MB ANALYSIS SHOWS UPPER LEVEL SUPPORT FALLING OFF DRAMATICALLY
BY 12Z FRIDAY MORNING AND WITH IT...THE LINE OF STORMS. THE BIG
QUESTION WILL BE IF ANY REMNANT BOUNDARIES WILL EXIST FURTHER EAST
FROM THE OVERNIGHT STORM ACTIVITY. IF SO...THOSE LOCATIONS WILL BE
THE FOCUS FOR ISOLATED HEAVY RAIN DEVELOPMENT FRIDAY AFTERNOON.
BEST GUESS AT THE MOMENT WOULD BE THE EASTERN HALF OF THE CWA. DUE
TO THE LOWER CONFIDENCE OF THIS POSSIBILITY...DID NOT INCLUDE THE
FLASH FLOOD WATCH FOR THE I35 CORRIDOR OR EAST. HOWEVER...AN
EXTENSION OR NEW WATCH MAY BE NEEDED IF THIS IS LOOKING MORE
LIKELY.
&&
.LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
OVER THE WEEKEND...THE ECMWF AND GFS DISAGREE ON A COLD FRONT
WHICH MAY IMPACT OUR NORTHERN BORDER BY LATE SATURDAY. IF SO...OUR
NORTHERN ZONES COULD HAVE ANOTHER RAINY WEEKEND AS THE FRONT WOULD
STALL AND WEAK BUT VERY MOIST SOUTHERLY SFC FLOW CREATES PROLONGED
THETA-E CONVERGENCE ALONG IT.
THE ECMWF SEEMS TO WASH OUT THIS BOUNDARY ACROSS NORTH TEXAS AND
BEGINS A TRANSITION PERIOD INTO WEAK FLOW AT ALL LEVELS. THIS
WOULD BE THE PREFERRED OUTCOME AS ONLY WEAK FORCING WOULD RESULT
IN MORE ISOLATED RAIN CHANCES OVER THE WEEKEND.
MOVING INTO NEXT WEEK...A RIDGING PATTERN BEGINS TO SET UP WITH
EARLY WEEK UPPER LEVEL WINDS BEING NORTHERLY. THE DRY LINE
CONTINUES TO BE DRAPED ACROSS THE NM/TX BORDER AND DEEP LAYER
MOISTURE SEEMS TO SUBSIDE. HOWEVER...SFC DEWPOINTS WILL STILL BE
IN THE UPPER 60S AND 70S SO ISOLATED THUNDER WILL BE IN PLAY MOST
AFTERNOONS NEXT WEEK. A VERY WELCOME PATTERN GIVEN THE ENTIRE
MONTH OF MAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 88 72 85 70 85 / 30 50 50 30 40
AUSTIN BERGSTROM INTL AIRPORT 88 71 84 69 85 / 20 50 50 20 40
NEW BRAUNFELS MUNI AIRPORT 89 72 85 71 85 / 20 50 40 20 40
BURNET MUNI AIRPORT 86 70 83 69 82 / 30 50 40 30 50
DEL RIO INTL AIRPORT 89 70 88 73 86 / 50 60 20 30 40
GEORGETOWN MUNI AIRPORT 87 71 84 70 84 / 30 50 50 30 50
HONDO MUNI AIRPORT 88 71 86 71 86 / 30 50 40 20 40
SAN MARCOS MUNI AIRPORT 87 72 84 70 85 / 20 50 50 20 40
LA GRANGE - FAYETTE REGIONAL 89 74 85 71 85 / 20 30 50 20 40
SAN ANTONIO INTL AIRPORT 89 73 86 72 85 / 20 50 40 20 40
STINSON MUNI AIRPORT 89 73 86 72 86 / 20 50 40 20 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR THE
FOLLOWING COUNTIES: BANDERA...EDWARDS...GILLESPIE...KERR...KINNEY...
LLANO...REAL...UVALDE...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...TB3
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1237 AM CDT THU MAY 28 2015
.AVIATION...
CIGS IN AUSTIN AND SAN ANTONIO HAVE DROPPED TO MVFR AND WILL DROP
TO IFR WITHIN THE NEXT COUPLE OF HOURS. AT DRT CIGS WILL DROP TO
MVFR BY AROUND 08Z AND THEN TO IFR A COUPLE OF HOURS AFTER THAT.
CIGS WILL IMPROVE BY LATE MORNING OR EARLY AFTERNOON. THERE IS A
SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING...BUT PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS. THE
BETTER CHANCES ARE AT DRT AND HAVE INCLUDED PROB30 GROUP TO
ACCOUNT FOR THIS.
&&
.PREV DISCUSSION... /ISSUED 913 PM CDT WED MAY 27 2015/
UPDATE... /FFA CANCELLED/
WHILE THERE WAS A BRIEF PERIOD WHERE CONVECTION TRIED TO
REGENERATE OVER CENTRAL TEXAS ALONG A DIFFERENTIAL HEATING
BOUNDARY LATE IN THE AFTERNOON...THE ATMOSPHERE HAS BECOME MORE
STABLE FOR THE REST OF TONIGHT WITH THE LOSS OF DAYTIME HEATING.
HIGH MOISTURE CONTENT IN THE ATMOSPHERE AND NOCTURNAL LOW LEVEL
WINDS OF 20-25 KNOTS OVER THE ESCARPMENT WILL LIKELY SUPPORT SOME
SCATTERED LIGHT SHOWERS AND POSSIBLY A THUNDERSTORM...BUT MAINLY
WEST OF THE AREA WHERE THE WATCH WAS IN EFFECT. MODEL CONSENSUS
SUGGESTS A MORE LIKELY THREAT FOR FLASH FLOODING TO DEVELOP
THURSDAY NIGHT. WILL LEAVE THE DECISION FOR A POSSIBLE NEW FLASH
FLOOD WATCH FOR LATER SHIFTS AS THE INCOMING 00Z MODEL RUNS SHOULD
SHOW LESS CONTAMINATION FROM EARLIER CONVECTION AND BOUNDARIES.
PREV DISCUSSION... /ISSUED 305 PM CDT WED MAY 27 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
VISIBLE SATELLITE IMAGES ARE SHOWING SEVERAL OUTFLOW BOUNDARIES
ACROSS THE REGION INCLUDING THE ONE THAT HELPED STORMS TO FIRE UP
ACROSS BLANCO AND TRAVIS COUNTIES MID MORNING. THERE ARE STILL
FEW THUNDERSTORMS ON GOING ACROSS WESTERN LLANO COUNTY AS THEY
SLOWLY PUSH TO THE NORTH. THIS ACTIVITY MAY COME TO AN END WITHIN
THE NEXT FEW HOURS. HOWEVER...LATER THIS EVENING...A LINE OR
COMPLEX OF STORMS ARE EXPECTED TO DEVELOP ALONG OUTFLOW BOUNDARIES
PUSHING WEST ACROSS CENTRAL TEXAS...AHEAD OF A DRY-LINE OVER WEST
TEXAS AND NORTH OF THE REMNANT OF THIS MORNING SURFACE/OUTFLOW
BOUNDARY. AT THIS TIME...SOME HIRES MODELS AND THE 12Z GFS
SOLUTION CONTINUE TO INDICATE CONVECTIVE INITIATION ACROSS CENTRAL
TEXAS AND PUSHING ACROSS THE NORTHERN HILL COUNTRY FOR THIS
EVENING. LATEST HRRR IS SHOWING CONVECTION NORTH OF BURNET AND
LLANO COUNTIES EARLY THIS EVENING BUT DISSIPATE ACTIVITY AROUND 8
OR 9 PM. LATEST ECM SOLUTION IS NOT SHOWING PRECIP ACROSS OUR AREA
THROUGH THE FIRST PERIOD. WITH ALL OF THESE DISAGREEMENTS IN
PLACE...WE DECIDED TO GO WITH THE MORE AGGRESSIVE SOLUTIONS WHICH
SHOWS SHOWERS AND THUNDERSTORMS AFFECTING THE NORTHERN PART OF
SOUTH CENTRAL TEXAS TONIGHT. ALSO...A FLASH FLOOD WATCH IS IN
EFFECT ACROSS THE HILL COUNTRY FROM 7 PM THIS EVENING THROUGH 7 AM
THURSDAY. THIS DECISION HAS BEEN MADE BASED ON GOING FLOOD ISSUES
ACROSS THE AREA AND THE LITTLE AMOUNTS OF RAINFALL THAT WILL TAKE
FOR AREAS TO FLOOD IN A SHORT PERIOD OF TIME. AS A REMINDER...WE
HAVE A LOW CONFIDENCE ON TONIGHT`S RAIN DUE TO POOR AGREEMENT
BETWEEN MODELS.
FOR THURSDAY NIGHT INTO FRIDAY...OUR CONFIDENCE INCREASE AS
MODELS AGREE ON BRINGING A LINE OF STRONG TO SEVERE STORMS ACROSS
THE EDWARDS PLATEAU AND RIO GRANDE PLAINS. HEAVY RAIN IS LIKELY
AND FLASH FLOODING IS POSSIBLE MAINLY ACROSS AREA
ROADS...UNDERPASSES...POOR DRAINAGE AREAS...AND SMALL CREEKS. A
FLASH FLOOD WATCH COULD BE ISSUED FOR AREAS WEST OF HIGHWAY 83
LATER TONIGHT OR THURSDAY.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS SOUTH CENTRAL TEXAS
THROUGH THE UPCOMING WEEKEND WITH A DRIER TREND EXPECTED FOR NEXT
WEEK. THE SUBTROPICAL RIDGE WILL BUILD ACROSS THE FOUR CORNERS
REGION AND BRING DRIER AND WARMER DAYS FOR MUCH OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 87 72 85 70 85 / 30 40 40 30 50
AUSTIN BERGSTROM INTL AIRPORT 86 72 85 70 84 / 30 40 40 20 50
NEW BRAUNFELS MUNI AIRPORT 87 73 85 70 85 / 30 30 40 20 40
BURNET MUNI AIRPORT 85 71 82 68 83 / 30 50 40 30 50
DEL RIO INTL AIRPORT 88 70 86 72 87 / 50 60 20 30 40
GEORGETOWN MUNI AIRPORT 86 72 84 69 84 / 30 40 40 30 50
HONDO MUNI AIRPORT 87 73 85 70 86 / 30 40 40 20 30
SAN MARCOS MUNI AIRPORT 86 72 84 69 84 / 30 30 40 20 40
LA GRANGE - FAYETTE REGIONAL 87 74 85 71 85 / 30 30 40 20 50
SAN ANTONIO INTL AIRPORT 87 74 85 71 85 / 30 40 40 20 40
STINSON MUNI AIRPORT 87 74 86 72 86 / 30 30 40 20 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...TB3
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
225 PM EDT THU MAY 28 2015
.SYNOPSIS...
HIGH PRESSURE IS CENTERED OFF THE SOUTHEAST ATLANTIC COAST AND WILL
MAINTAIN A BROAD SOUTHERLY FLOW OF MOISTURE INTO THE REGION
THROUGH THE REMAINDER OF THIS WEEK...A PATTERN THAT WILL FEATURE
WARM/HUMID SUMMERLIKE CONDITIONS. IN ADDITION TO THE HEAT/HUMIDITY...
THERE WILL BE A DAILY THREAT OF SCATTERED SHOWERS/STORMS. FOR
TODAY THE STORM POTENTIAL WILL BE MOST PRONOUNCED ALONG A WEAK
COLD FRONT THAT WILL BE APPROACHING THE AREA FROM THE NORTHWEST.
ADDITIONAL SHOWERS/STORMS WILL ACCOMPANY AN UPPER LEVEL
DISTURBANCE THAT WILL BE MOVING NORTHEAST THROUGH THE TENNESSEE
VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM EDT THURSDAY...
NO CHANGES NEEDED TO THE CURRENT FORECAST GRID SET. VISIBLE
SATELLITE IMAGES SHOW MOSTLY CLEAR SKIES OVER THE AREA AS ANY EARLY
MORNING FOG/STRATUS HAS BURNED OFF. APPROACHING BROAD/DIFFUSE
FRONTAL ZONE COMBINED WITH TROFINESS OVER THE REGION SHOULD BE
MORE THAN ENOUGH TO GENERATE SOME CONVECTIVE ACTIVITY THIS
AFTERNOON WITH OROGRAPHIC AFFECTS ADDING ENHANCEMENT FROM THE
BLUE RIDGE WESTWARD. WATER VAPOR IMAGERY SHOWED A BIT OF DRY AIR
ALOFT AND THIS WAS EVIDENT IN THE MORNING RNK SOUNDING AS WELL.
HOWEVER...THE COLUMN WILL MOISTEN TODAY AND EXPECT THE PROSPECT OF
SLOW MOVING THUNDERSTORMS WITH HEAVY RAIN IS STILL A GOOD BET.
PREVIOUS AFD...
A WEAK COLD FRONT EXTENDS FROM WESTERN NEW YORK INTO THE OHIO
VALLEY. THIS FRONT WILL MOVE SOUTHEAST INTO THE VA/WV HIGHLANDS
TODAY BEFORE DISSIPATING OVER THE REGION TONIGHT. IN ADDITION TO
THE FRONT...AN UPPER LEVEL DISTURBANCE WILL BE MOVING NORTHEAST
THROUGH THE TENNESSEE VALLEY...AND WILL INTERACT WITH THE
APPROACHING SURFACE FRONT TO PROVIDE LIFT FOR SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING. BEST COVERAGE OF
SHOWERS/STORMS TODAY WILL BE ACROSS THE MOUNTAINS WEST OF THE BLUE
RIDGE. STEERING WINDS ARE WEAK...SFC-20KFT MEAN FLOW OF 10KTS OR
LESS. THIS SUGGESTS ANY ACTIVITY THAT DEVELOPS TODAY WILL BE SLOW
MOVING AND WILL PROLONG THE HEAVIER SHOWERS ONCE THEY DEVELOP.
BOTH THE HIGH RES-WRF AND HRRR INDICATE THAT SHOWERS WILL BEGIN TO
DEVELOP OVER OUR MTNS AROUND MID-DAY...BECOMING MOST PRONOUNCED
BETWEEN 20Z/3PM AND SUNSET 01Z/9PM.
THE OVERALL THREAT FOR WIDESPREAD HAZARDOUS WEATHER IS
LOW...HOWEVER WITH PRESENCE OF THE UPPER LEVEL DISTURBANCE...CAN`T
RULE OUT SOME PULSE SEVERE STORMS THIS AFTERNOON. MODEL FORECAST
CAPE OF 2500 J/KG COUPLED WITH FORECAST DCAPE OF 1000 MAY BE
ENOUGH FOR SOME ISOLATED MICROBURSTS.
TEMPERATURES TODAY WILL BE SUMMER-LIKE WITH HIGHS IN THE
80S...COMPLIMENTED BY DEWPOINTS IN THE U50S-LOWER 60S.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 500 AM EDT THURSDAY...
UPPER LEVEL RIDGING WILL REMAIN IN PLACE ALONG THE EAST COAST ON
FRIDAY...BUT WILL SLOWLY BREAK DOWN DURING THE WEEKEND...GIVING WAY
TO A FLATTENING...MORE ZONAL PATTERN AS AN UPPER LEVEL TROUGH SHIFTS
ACROSS EASTERN CANADA. THE PASSAGE OF THIS TROUGH WILL PUSH A COLD
FRONT SOUTHWARD...WHERE IT WILL ENTER OUR AREA SUNDAY AFTERNOON
BEFORE STALLING.
FOR FRIDAY AND SATURDAY...SPOTTY SHOWERS AND THUNDERSTORMS WILL
DEVELOP ACROSS THE MOUNTAINS EARLY BOTH AFTERNOONS...WITH COVERAGE
PEAKING DURING EARLY EVENING. CONVECTION WILL WEAKEN AND FADE AROUND
SUNSET WITH LOSS OF HEATING...BUT STILL EXPECT LIGHT SHOWER TO TWO
TO FLOAT ACROSS THE AREA OVERNIGHT. MAY SEE ONE OR TWO STORMS BECOME
STRONG...BUT THE BIGGER CONCERN IS LIGHT UPPER LEVEL WINDS/SLOW CELL
MOVEMENT...WHICH MAY RESULT IN LOCALLY HEAVY RAIN IF CELLS STALL OR
TRAIN. AFTERNOON HIGHS WILL RANGE FROM THE UPPER 70S AND LOW 80S
ACROSS THE MOUNTAINS...TO THE MID 80S ACROSS THE PIEDMONT. OVERNIGHT
LOWS WILL FALL INTO THE LOW/MID 60S.
EXPECT GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY AS
THE COLD FRONT APPROACHES. WHILE THE UPPER LEVEL DYNAMICS STILL
APPEAR TO BE MARGINAL...INCREASED CONVERGENCE IN THE LOW LEVELS
SHOULD BE ENOUGH TO SUPPORT A SLIGHTLY BETTER CHANCE OF STRONG
STORMS DURING THE AFTERNOON AND EVENING...PERHAPS WITH A FEW STORMS
BECOMING SEVERE. THE COLD FRONT WILL ENTER THE INTERSTATE 64
CORRIDOR BY EARLY EVENING...AND EVENTUALLY STALL SOMEWHERE ACROSS
OUR AREA FOR THE REMAINDER OF THE NIGHT...PROVIDING THE FOCUS FOR
SPOTTY SHOWERS INTO MONDAY MORNING. INCREASED CLOUDS WILL MAKE FOR
SLIGHTLY COOLER TEMPERATURES ACROSS THE MOUNTAINS...WITH HIGHS IN
THE MID/UPPER 70S...WHILE THE PIEDMONT WILL REACH THE UPPER 80S.
LOWS WILL BE IN THE UPPER 50S NEAR INTERSTATE 64...AND HOLD IN THE
MID 60S FURTHER SOUTH.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 500 AM EDT THURSDAY...
BY MONDAY...THE UPPER PATTERN WILL HAVE ESTABLISHED A SPLIT FLOW
REGIME ACROSS THE NORTHERN TIER OF STATES AS A CLOSED LOW DEVELOPS
OVER THE LOWER MISSISSIPPI VALLEY AND SLOWLY SINKS SOUTHWARD THROUGH
THE MIDDLE OF NEXT WEEK. SOME RIDGING WILL ALSO BE TAKING PLACE OVER
THE MID ATLANTIC REGION AND SET UP A SLUGGISH BLOCKY PATTERN.
AT THE SURFACE...HIGH PRESSURE PASSING EAST ACROSS THE GREAT LAKES
WILL SPREAD ACROSS THE NORTHEAST AND WEDGE DOWN THE EASTERN
SEABOARD...GIVE THE COLD FRONT A RENEWED PUSH THROUGH OUR AREA. THE
HIGH WILL BRING COOLER/NEAR NORMAL TEMPERATURES TO THE REGION.
HOWEVER...THE PATTERN WILL KEEP US MOIST WITH DEEP SOUTHEASTERLY
FLOW AND EXPECT ENOUGH FORCING BETWEEN OROGRAPHIC UPSLOPE AND
DIURNAL EFFECTS TO KEEP SOME SHOWER ACTIVITY...AND POSSIBLY A
THUNDERSTORM...IN THE FORECAST THROUGH THE PERIOD.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 215 PM EDT THURSDAY...
VISIBLE SATELLITE IMAGES SHOW CU/CB DEVELOPMENT THIS AFTERNOON
ESPECIALLY PREVALENT FROM THE BLUE RIDGE WEST...AND RADAR SHOWS
SCATTERED SHOWERS/THUNDERSTORMS MATCHING IN A SIMILAR PATTERN.
WHILE THERE IS AMPLE INSTABILITY ACROSS THE REGION TO SUPPORT
CONVECTION WE CONTINUE TO LACK ANYTHING RESEMBLING SIGNIFICANT
DYNAMICS SO STORMS WILL LACK ORGANIZATION SAVE FOR WHAT THEY
CAN MUSTER THROUGH OUTFLOW BOUNDARY INTERACTION. THIS WILL MAKE
IT DIFFICULT TO PIN ACTIVITY TO A SINGLE LOCATION/TIME SO EXPECT
VFR CONDITIONS OUTSIDE OF SHOWERS/STORMS. WILL USE VCTS AT ALL
LOCATIONS EARLY IN THE TAF PERIOD AND AMEND AS CONDITIONS DICTATE.
SHOWERS AND STORMS SHOULD TAPER OFF RAPIDLY WITH LOSS OF HEATING
AFTER SUNSET. MEDIUM TO LOW CONFIDENCE IN FOG POTENTIAL AS IT WILL
BE CONTINGENT ON HOW MUCH MID/UPPER CLOUD DEBRIS LINGERS OVER THE
AREA TO HINDER RADIATIONAL COOLING. WILL GO ALONG WITH GUIDANCE
AND PERSISTENCE FROM LAST NIGHT AND INTRODUCE SOME FOG/STRATUS
MOST LOCATIONS TOWARD DAYBREAK. ANY LOCATIONS THAT GET
PRECIPITATION TODAY WILL LIKELY FOG IN BUT WILL HAVE TO WAIT AND
SEE HOW THINGS UNFOLD THROUGH THIS EVENING. ANY FOG/STRATUS WILL
BURN OFF AFTER DAYBREAK TOMORROW AND ANOTHER ROUND OF DIURNAL
CONVECTION WILL BEGIN TOWARD THE END OF THE TAF PERIOD...BUT
CONFIDENCE IS FAR TO LOW TO INDICATE CONVECTIVE INITIATION
SPECIFIC TO TAF SITES THAT FAR OUT.
EXTENDED AVIATION DISCUSSION...
THROUGH THE UPCOMING WEEKEND...A MOIST UNSTABLE AIR MASS WILL
REMAIN IN PLACE ACROSS THE REGION WITH ONLY WEAK FORCING. THIS
WILL RESULT IN MAINLY SLOW MOVING DIURNALLY DRIVE DEEP CONVECTION
DURING THE AFTERNOON AND EVENING HOURS FOLLOWED BY STABLE
CONDITIONS AT NIGHT. A FRONTAL SYSTEM WILL APPROACH FROM THE
NORTH DURING THE WEEKEND...BUT WILL LIKELY REMAIN WELL NORTH OF
THE FORECAST AREA THROUGH SUNDAY. THUS...NO CHANGE IN AIR MASS IS
EXPECTED THROUGH THE PERIOD.
WITH MOIST/STABLE CONDITIONS AT NIGHT...PATCHY LATE NIGHT/EARLY
MORNING LOW CLOUDS/FOG AND ASSOCIATED IFR-LIFR CIGS/VSBYS WILL BE
POSSIBLE EACH MORNING...BUT LIMITED TO A FEW HOURS BEFORE DAYBREAK
AND QUICKLY BURNING OFF AFTER SUNRISE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...MBS/PM
SHORT TERM...NF
LONG TERM...NF/MBS
AVIATION...MBS/PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1006 AM EDT THU MAY 28 2015
.SYNOPSIS...
HIGH PRESSURE IS CENTERED OFF THE SOUTHEAST ATLANTIC COAST AND WILL
MAINTAIN A BROAD SOUTHERLY FLOW OF MOISTURE INTO THE REGION
THROUGH THE REMAINDER OF THIS WEEK...A PATTERN THAT WILL FEATURE
WARM/HUMID SUMMERLIKE CONDITIONS. IN ADDITION TO THE HEAT/HUMIDITY...
THERE WILL BE A DAILY THREAT OF SCATTERED SHOWERS/STORMS. FOR
TODAY THE STORM POTENTIAL WILL BE MOST PRONOUNCED ALONG A WEAK
COLD FRONT THAT WILL BE APPROACHING THE AREA FROM THE NORTHWEST.
ADDITIONAL SHOWERS/STORMS WILL ACCOMPANY AN UPPER LEVEL
DISTURBANCE THAT WILL BE MOVING NORTHEAST THROUGH THE TENNESSEE
VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM EDT THURSDAY...
NO CHANGES NEEDED TO THE CURRENT FORECAST GRID SET. VISIBLE
SATELLITE IMAGES SHOW MOSTLY CLEAR SKIES OVER THE AREA AS ANY EARLY
MORNING FOG/STRATUS HAS BURNED OFF. APPROACHING BROAD/DIFFUSE
FRONTAL ZONE COMBINED WITH TROFINESS OVER THE REGION SHOULD BE
MORE THAN ENOUGH TO GENERATE SOME CONVECTIVE ACTIVITY THIS
AFTERNOON WITH OROGRAPHIC AFFECTS ADDING ENHANCEMENT FROM THE
BLUE RIDGE WESTWARD. WATER VAPOR IMAGERY SHOWED A BIT OF DRY AIR
ALOFT AND THIS WAS EVIDENT IN THE MORNING RNK SOUNDING AS WELL.
HOWEVER...THE COLUMN WILL MOISTEN TODAY AND EXPECT THE PROSPECT OF
SLOW MOVING THUNDERSTORMS WITH HEAVY RAIN IS STILL A GOOD BET.
PREVIOUS AFD...
A WEAK COLD FRONT EXTENDS FROM WESTERN NEW YORK INTO THE OHIO
VALLEY. THIS FRONT WILL MOVE SOUTHEAST INTO THE VA/WV HIGHLANDS
TODAY BEFORE DISSIPATING OVER THE REGION TONIGHT. IN ADDITION TO
THE FRONT...AN UPPER LEVEL DISTURBANCE WILL BE MOVING NORTHEAST
THROUGH THE TENNESSEE VALLEY...AND WILL INTERACT WITH THE
APPROACHING SURFACE FRONT TO PROVIDE LIFT FOR SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING. BEST COVERAGE OF
SHOWERS/STORMS TODAY WILL BE ACROSS THE MOUNTAINS WEST OF THE BLUE
RIDGE. STEERING WINDS ARE WEAK...SFC-20KFT MEAN FLOW OF 10KTS OR
LESS. THIS SUGGESTS ANY ACTIVITY THAT DEVELOPS TODAY WILL BE SLOW
MOVING AND WILL PROLONG THE HEAVIER SHOWERS ONCE THEY DEVELOP.
BOTH THE HIGH RES-WRF AND HRRR INDICATE THAT SHOWERS WILL BEGIN TO
DEVELOP OVER OUR MTNS AROUND MID-DAY...BECOMING MOST PRONOUNCED
BETWEEN 20Z/3PM AND SUNSET 01Z/9PM.
THE OVERALL THREAT FOR WIDESPREAD HAZARDOUS WEATHER IS
LOW...HOWEVER WITH PRESENCE OF THE UPPER LEVEL DISTURBANCE...CAN`T
RULE OUT SOME PULSE SEVERE STORMS THIS AFTERNOON. MODEL FORECAST
CAPE OF 2500 J/KG COUPLED WITH FORECAST DCAPE OF 1000 MAY BE
ENOUGH FOR SOME ISOLATED MICROBURSTS.
TEMPERATURES TODAY WILL BE SUMMER-LIKE WITH HIGHS IN THE
80S...COMPLIMENTED BY DEWPOINTS IN THE U50S-LOWER 60S.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 500 AM EDT THURSDAY...
UPPER LEVEL RIDGING WILL REMAIN IN PLACE ALONG THE EAST COAST ON
FRIDAY...BUT WILL SLOWLY BREAK DOWN DURING THE WEEKEND...GIVING WAY
TO A FLATTENING...MORE ZONAL PATTERN AS AN UPPER LEVEL TROUGH SHIFTS
ACROSS EASTERN CANADA. THE PASSAGE OF THIS TROUGH WILL PUSH A COLD
FRONT SOUTHWARD...WHERE IT WILL ENTER OUR AREA SUNDAY AFTERNOON
BEFORE STALLING.
FOR FRIDAY AND SATURDAY...SPOTTY SHOWERS AND THUNDERSTORMS WILL
DEVELOP ACROSS THE MOUNTAINS EARLY BOTH AFTERNOONS...WITH COVERAGE
PEAKING DURING EARLY EVENING. CONVECTION WILL WEAKEN AND FADE AROUND
SUNSET WITH LOSS OF HEATING...BUT STILL EXPECT LIGHT SHOWER TO TWO
TO FLOAT ACROSS THE AREA OVERNIGHT. MAY SEE ONE OR TWO STORMS BECOME
STRONG...BUT THE BIGGER CONCERN IS LIGHT UPPER LEVEL WINDS/SLOW CELL
MOVEMENT...WHICH MAY RESULT IN LOCALLY HEAVY RAIN IF CELLS STALL OR
TRAIN. AFTERNOON HIGHS WILL RANGE FROM THE UPPER 70S AND LOW 80S
ACROSS THE MOUNTAINS...TO THE MID 80S ACROSS THE PIEDMONT. OVERNIGHT
LOWS WILL FALL INTO THE LOW/MID 60S.
EXPECT GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY AS
THE COLD FRONT APPROACHES. WHILE THE UPPER LEVEL DYNAMICS STILL
APPEAR TO BE MARGINAL...INCREASED CONVERGENCE IN THE LOW LEVELS
SHOULD BE ENOUGH TO SUPPORT A SLIGHTLY BETTER CHANCE OF STRONG
STORMS DURING THE AFTERNOON AND EVENING...PERHAPS WITH A FEW STORMS
BECOMING SEVERE. THE COLD FRONT WILL ENTER THE INTERSTATE 64
CORRIDOR BY EARLY EVENING...AND EVENTUALLY STALL SOMEWHERE ACROSS
OUR AREA FOR THE REMAINDER OF THE NIGHT...PROVIDING THE FOCUS FOR
SPOTTY SHOWERS INTO MONDAY MORNING. INCREASED CLOUDS WILL MAKE FOR
SLIGHTLY COOLER TEMPERATURES ACROSS THE MOUNTAINS...WITH HIGHS IN
THE MID/UPPER 70S...WHILE THE PIEDMONT WILL REACH THE UPPER 80S.
LOWS WILL BE IN THE UPPER 50S NEAR INTERSTATE 64...AND HOLD IN THE
MID 60S FURTHER SOUTH.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 500 AM EDT THURSDAY...
BY MONDAY...THE UPPER PATTERN WILL HAVE ESTABLISHED A SPLIT FLOW
REGIME ACROSS THE NORTHERN TIER OF STATES AS A CLOSED LOW DEVELOPS
OVER THE LOWER MISSISSIPPI VALLEY AND SLOWLY SINKS SOUTHWARD THROUGH
THE MIDDLE OF NEXT WEEK. SOME RIDGING WILL ALSO BE TAKING PLACE OVER
THE MID ATLANTIC REGION AND SET UP A SLUGGISH BLOCKY PATTERN.
AT THE SURFACE...HIGH PRESSURE PASSING EAST ACROSS THE GREAT LAKES
WILL SPREAD ACROSS THE NORTHEAST AND WEDGE DOWN THE EASTERN
SEABOARD...GIVE THE COLD FRONT A RENEWED PUSH THROUGH OUR AREA. THE
HIGH WILL BRING COOLER/NEAR NORMAL TEMPERATURES TO THE REGION.
HOWEVER...THE PATTERN WILL KEEP US MOIST WITH DEEP SOUTHEASTERLY
FLOW AND EXPECT ENOUGH FORCING BETWEEN OROGRAPHIC UPSLOPE AND
DIURNAL EFFECTS TO KEEP SOME SHOWER ACTIVITY...AND POSSIBLY A
THUNDERSTORM...IN THE FORECAST THROUGH THE PERIOD.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 800 AM EDT THURSDAY...
EARLY MORNING FOG/STRATUS WILL DISSIPATE BY 10AM...THEN
ANTICIPATING VFR THROUGH EARLY AFTERNOON. DAYTIME HEATING...IN
ADDITION TO SOME LIFT FROM APPROACHING FRONT OVER THE OHIO VALLEY
AND VORTICITY ASSOCIATED WITH CONVECTIVE DEBRIS MOVING NORTH FROM
THE SOUTHERN APPALACHIANS...SHOULD RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE MID/LATE AFTERNOON AND EVENING. MESOSCALE
MODELS FOCUS THE GREATEST COVERAGE BETWEEN 20Z/3PM AND
01Z/9PM...AND MAINLY ACROSS THE MOUNTAINS ALONG AND WEST OF THE
BLUE RIDGE. MEAN WINDS FROM SFC- 20KFT ARE FCST TO BE LESS THAN 10
KTS...SO SHOWERS/STORMS THAT DEVELOP SHOULD BE SLOW MOVING.
SURFACE WINDS THROUGH THE TAF VALID PERIOD WILL BE LIGHT AND
VARIABLE...SPEEDS MOSTLY 7KTS OR LESS.
LATE NIGHT FOG/STRATUS IS EXPECTED AGAIN TONIGHT AND EARLY
FRIDAY...ESPECIALLY IN THE MOUNTAIN VALLEYS AND AN LOCATION WHICH
RECEIVES WETTING SHOWERS TODAY.
EXTENDED AVIATION DISCUSSION...
THROUGH THE UPCOMING WEEKEND...A MOIST UNSTABLE AIR MASS WILL
REMAIN IN PLACE ACROSS THE REGION WITH ONLY WEAK FORCING. THIS
WILL RESULT IN MAINLY SLOW MOVING DIURNALLY DRIVE DEEP CONVECTION
DURING THE AFTERNOON AND EVENING HOURS FOLLOWED BY STABLE
CONDITIONS AT NIGHT. A FRONTAL SYSTEM WILL APPROACH FROM THE
NORTH DURING THE WEEKEND...BUT WILL LIKELY REMAIN WELL NORTH OF
THE FORECAST AREA THROUGH SUNDAY. THUS...NO CHANGE IN AIR MASS IS
EXPECTED THROUGH THE PERIOD.
WITH MOIST/STABLE CONDITIONS AT NIGHT...PATCHY LATE NIGHT/EARLY
MORNING LOW CLOUDS/FOG AND ASSOCIATED IFR-LIFR CIGS/VSBYS WILL BE
POSSIBLE EACH MORNING...BUT LIMITED TO A FEW HOURS BEFORE DAYBREAK
AND QUICKLY BURNING OFF AFTER SUNRISE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...MBS/PM
SHORT TERM...NF
LONG TERM...MBS/NF
AVIATION...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
742 AM EDT THU MAY 28 2015
.SYNOPSIS...
HIGH PRESSURE IS CENTERED OFF THE SOUTHEAST ATLANTIC COAST AND WILL
MAINTAIN A BROAD SOUTHERLY FLOW OF MOISTURE INTO THE REGION
THROUGH THE REMAINDER OF THIS WEEK...A PATTERN THAT WILL FEATURE
WARM/HUMID SUMMERLIKE CONDITIONS. IN ADDITION TO THE HEAT/HUMIDITY...
THERE WILL BE A DAILY THREAT OF SCATTERED SHOWERS/STORMS. FOR
TODAY THE STORM POTENTIAL WILL BE MOST PRONOUNCED ALONG A WEAK
COLD FRONT THAT WILL BE APPROACHING THE AREA FROM THE NORTHWEST.
ADDITIONAL SHOWERS/STORMS WILL ACCOMPANY AN UPPER LEVEL
DISTURBANCE THAT WILL BE MOVING NORTHEAST THROUGH THE TENNESSEE
VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 530 AM EDT THURSDAY...
A WEAK COLD FRONT EXTENDS FROM WESTERN NEW YORK INTO THE OHIO
VALLEY. THIS FRONT WILL MOVE SOUTHEAST INTO THE VA/WV HIGHLANDS
TODAY BEFORE DISSIPATING OVER THE REGION TONIGHT. IN ADDITION TO
THE FRONT...AN UPPER LEVEL DISTURBANCE WILL BE MOVING NORTHEAST
THROUGH THE TENNESSEE VALLEY...AND WILL INTERACT WITH THE
APPROACHING SURFACE FRONT TO PROVIDE LIFT FOR SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING. BEST COVERAGE OF
SHOWERS/STORMS TODAY WILL BE ACROSS THE MOUNTAINS WEST OF THE BLUE
RIDGE. STEERING WINDS ARE WEAK...SFC-20KFT MEAN FLOW OF 10KTS OR
LESS. THIS SUGGESTS ANY ACTIVITY THAT DEVELOPS TODAY WILL BE SLOW
MOVING AND WILL PROLONG THE HEAVIER SHOWERS ONCE THEY DEVELOP.
BOTH THE HIGH RES-WRF AND HRRR INDICATE THAT SHOWERS WILL BEGIN TO
DEVELOP OVER OUR MTNS AROUND MID-DAY...BECOMING MOST PRONOUNCED
BETWEEN 20Z/3PM AND SUNSET 01Z/9PM.
THE OVERALL THREAT FOR WIDESPREAD HAZARDOUS WEATHER IS
LOW...HOWEVER WITH PRESENCE OF THE UPPER LEVEL DISTURBANCE...CAN`T
RULE OUT SOME PULSE SEVERE STORMS THIS AFTERNOON. MODEL FORECAST
CAPE OF 2500 J/KG COUPLED WITH FORECAST DCAPE OF 1000 MAY BE
ENOUGH FOR SOME ISOLATED MICROBURSTS.
TEMPERATURES TODAY WILL BE SUMMER-LIKE WITH HIGHS IN THE
80S...COMPLIMENTED BY DEWPOINTS IN THE U50S-LOWER 60S.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 500 AM EDT THURSDAY...
UPPER LEVEL RIDGING WILL REMAIN IN PLACE ALONG THE EAST COAST ON
FRIDAY...BUT WILL SLOWLY BREAK DOWN DURING THE WEEKEND...GIVING WAY
TO A FLATTENING...MORE ZONAL PATTERN AS AN UPPER LEVEL TROUGH SHIFTS
ACROSS EASTERN CANADA. THE PASSAGE OF THIS TROUGH WILL PUSH A COLD
FRONT SOUTHWARD...WHERE IT WILL ENTER OUR AREA SUNDAY AFTERNOON
BEFORE STALLING.
FOR FRIDAY AND SATURDAY...SPOTTY SHOWERS AND THUNDERSTORMS WILL
DEVELOP ACROSS THE MOUNTAINS EARLY BOTH AFTERNOONS...WITH COVERAGE
PEAKING DURING EARLY EVENING. CONVECTION WILL WEAKEN AND FADE AROUND
SUNSET WITH LOSS OF HEATING...BUT STILL EXPECT LIGHT SHOWER TO TWO
TO FLOAT ACROSS THE AREA OVERNIGHT. MAY SEE ONE OR TWO STORMS BECOME
STRONG...BUT THE BIGGER CONCERN IS LIGHT UPPER LEVEL WINDS/SLOW CELL
MOVEMENT...WHICH MAY RESULT IN LOCALLY HEAVY RAIN IF CELLS STALL OR
TRAIN. AFTERNOON HIGHS WILL RANGE FROM THE UPPER 70S AND LOW 80S
ACROSS THE MOUNTAINS...TO THE MID 80S ACROSS THE PIEDMONT. OVERNIGHT
LOWS WILL FALL INTO THE LOW/MID 60S.
EXPECT GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY AS
THE COLD FRONT APPROACHES. WHILE THE UPPER LEVEL DYNAMICS STILL
APPEAR TO BE MARGINAL...INCREASED CONVERGENCE IN THE LOW LEVELS
SHOULD BE ENOUGH TO SUPPORT A SLIGHTLY BETTER CHANCE OF STRONG
STORMS DURING THE AFTERNOON AND EVENING...PERHAPS WITH A FEW STORMS
BECOMING SEVERE. THE COLD FRONT WILL ENTER THE INTERSTATE 64
CORRIDOR BY EARLY EVENING...AND EVENTUALLY STALL SOMEWHERE ACROSS
OUR AREA FOR THE REMAINDER OF THE NIGHT...PROVIDING THE FOCUS FOR
SPOTTY SHOWERS INTO MONDAY MORNING. INCREASED CLOUDS WILL MAKE FOR
SLIGHTLY COOLER TEMPERATURES ACROSS THE MOUNTAINS...WITH HIGHS IN
THE MID/UPPER 70S...WHILE THE PIEDMONT WILL REACH THE UPPER 80S.
LOWS WILL BE IN THE UPPER 50S NEAR INTERSTATE 64...AND HOLD IN THE
MID 60S FURTHER SOUTH.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 500 AM EDT THURSDAY...
BY MONDAY...THE UPPER PATTERN WILL HAVE ESTABLISHED A SPLIT FLOW
REGIME ACROSS THE NORTHERN TIER OF STATES AS A CLOSED LOW DEVELOPS
OVER THE LOWER MISSISSIPPI VALLEY AND SLOWLY SINKS SOUTHWARD THROUGH
THE MIDDLE OF NEXT WEEK. SOME RIDGING WILL ALSO BE TAKING PLACE OVER
THE MID ATLANTIC REGION AND SET UP A SLUGGISH BLOCKY PATTERN.
AT THE SURFACE...HIGH PRESSURE PASSING EAST ACROSS THE GREAT LAKES
WILL SPREAD ACROSS THE NORTHEAST AND WEDGE DOWN THE EASTERN
SEABOARD...GIVE THE COLD FRONT A RENEWED PUSH THROUGH OUR AREA. THE
HIGH WILL BRING COOLER/NEAR NORMAL TEMPERATURES TO THE REGION.
HOWEVER...THE PATTERN WILL KEEP US MOIST WITH DEEP SOUTHEASTERLY
FLOW AND EXPECT ENOUGH FORCING BETWEEN OROGRAPHIC UPSLOPE AND
DIURNAL EFFECTS TO KEEP SOME SHOWER ACTIVITY...AND POSSIBLY A
THUNDERSTORM...IN THE FORECAST THROUGH THE PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 800 AM EDT THURSDAY...
EARLY MORNING FOG/STRATUS WILL DISSIPATE BY 10AM...THEN
ANTICIPATING VFR THROUGH EARLY AFTERNOON. DAYTIME HEATING...IN
ADDITION TO SOME LIFT FROM APPROACHING FRONT OVER THE OHIO VALLEY
AND VORTICITY ASSOCIATED WITH CONVECTIVE DEBRIS MOVING NORTH FROM
THE SOUTHERN APPALACHIANS...SHOULD RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE MID/LATE AFTERNOON AND EVENING. MESOSCALE
MODELS FOCUS THE GREATEST COVERAGE BETWEEN 20Z/3PM AND
01Z/9PM...AND MAINLY ACROSS THE MOUNTAINS ALONG AND WEST OF THE
BLUE RIDGE. MEAN WINDS FROM SFC- 20KFT ARE FCST TO BE LESS THAN 10
KTS...SO SHOWERS/STORMS THAT DEVELOP SHOULD BE SLOW MOVING.
SURFACE WINDS THROUGH THE TAF VALID PERIOD WILL BE LIGHT AND
VARIABLE...SPEEDS MOSTLY 7KTS OR LESS.
LATE NIGHT FOG/STRATUS IS EXPECTED AGAIN TONIGHT AND EARLY
FRIDAY...ESPECIALLY IN THE MOUNTAIN VALLEYS AND AN LOCATION WHICH
RECEIVES WETTING SHOWERS TODAY.
EXTENDED AVIATION DISCUSSION...
THROUGH THE UPCOMING WEEKEND...A MOIST UNSTABLE AIR MASS WILL
REMAIN IN PLACE ACROSS THE REGION WITH ONLY WEAK FORCING. THIS
WILL RESULT IN MAINLY SLOW MOVING DIURNALLY DRIVE DEEP CONVECTION
DURING THE AFTERNOON AND EVENING HOURS FOLLOWED BY STABLE
CONDITIONS AT NIGHT. A FRONTAL SYSTEM WILL APPROACH FROM THE
NORTH DURING THE WEEKEND...BUT WILL LIKELY REMAIN WELL NORTH OF
THE FORECAST AREA THROUGH SUNDAY. THUS...NO CHANGE IN AIR MASS IS
EXPECTED THROUGH THE PERIOD.
WITH MOIST/STABLE CONDITIONS AT NIGHT...PATCHY LATE NIGHT/EARLY
MORNING LOW CLOUDS/FOG AND ASSOCIATED IFR-LIFR CIGS/VSBYS WILL BE
POSSIBLE EACH MORNING...BUT LIMITED TO A FEW HOURS BEFORE DAYBREAK
AND QUICKLY BURNING OFF AFTER SUNRISE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...PM
SHORT TERM...NF
LONG TERM...MBS/NF
AVIATION...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
603 AM EDT THU MAY 28 2015
.SYNOPSIS...
HIGH PRESSURE IS CENTERED OFF THE SOUTHEAST ATLANTIC COAST AND WILL
MAINTAIN A BROAD SOUTHERLY FLOW OF MOISTURE INTO THE REGION
THROUGH THE REMAINDER OF THIS WEEK...A PATTERN THAT WILL FEATURE
WARM/HUMID SUMMERLIKE CONDITIONS. IN ADDITION TO THE HEAT/HUMIDITY...
THERE WILL BE A DAILY THREAT OF SCATTERED SHOWERS/STORMS. FOR
TODAY THE STORM POTENTIAL WILL BE MOST PRONOUNCED ALONG A WEAK
COLD FRONT THAT WILL BE APPROACHING THE AREA FROM THE NORTHWEST.
ADDITIONAL SHOWERS/STORMS WILL ACCOMPANY AN UPPER LEVEL
DISTURBANCE THAT WILL BE MOVING NORTHEAST THROUGH THE TENNESSEE
VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 530 AM EDT THURSDAY...
A WEAK COLD FRONT EXTENDS FROM WESTERN NEW YORK INTO THE OHIO
VALLEY. THIS FRONT WILL MOVE SOUTHEAST INTO THE VA/WV HIGHLANDS
TODAY BEFORE DISSIPATING OVER THE REGION TONIGHT. IN ADDITION TO
THE FRONT...AN UPPER LEVEL DISTURBANCE WILL BE MOVING NORTHEAST
THROUGH THE TENNESSEE VALLEY...AND WILL INTERACT WITH THE
APPROACHING SURFACE FRONT TO PROVIDE LIFT FOR SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING. BEST COVERAGE OF
SHOWERS/STORMS TODAY WILL BE ACROSS THE MOUNTAINS WEST OF THE BLUE
RIDGE. STEERING WINDS ARE WEAK...SFC-20KFT MEAN FLOW OF 10KTS OR
LESS. THIS SUGGESTS ANY ACTIVITY THAT DEVELOPS TODAY WILL BE SLOW
MOVING AND WILL PROLONG THE HEAVIER SHOWERS ONCE THEY DEVELOP.
BOTH THE HIGH RES-WRF AND HRRR INDICATE THAT SHOWERS WILL BEGIN TO
DEVELOP OVER OUR MTNS AROUND MID-DAY...BECOMING MOST PRONOUNCED
BETWEEN 20Z/3PM AND SUNSET 01Z/9PM.
THE OVERALL THREAT FOR WIDESPREAD HAZARDOUS WEATHER IS
LOW...HOWEVER WITH PRESENCE OF THE UPPER LEVEL DISTURBANCE...CAN`T
RULE OUT SOME PULSE SEVERE STORMS THIS AFTERNOON. MODEL FORECAST
CAPE OF 2500 J/KG COUPLED WITH FORECAST DCAPE OF 1000 MAY BE
ENOUGH FOR SOME ISOLATED MICROBURSTS.
TEMPERATURES TODAY WILL BE SUMMER-LIKE WITH HIGHS IN THE
80S...COMPLIMENTED BY DEWPOINTS IN THE U50S-LOWER 60S.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 500 AM EDT THURSDAY...
UPPER LEVEL RIDGING WILL REMAIN IN PLACE ALONG THE EAST COAST ON
FRIDAY...BUT WILL SLOWLY BREAK DOWN DURING THE WEEKEND...GIVING WAY
TO A FLATTENING...MORE ZONAL PATTERN AS AN UPPER LEVEL TROUGH SHIFTS
ACROSS EASTERN CANADA. THE PASSAGE OF THIS TROUGH WILL PUSH A COLD
FRONT SOUTHWARD...WHERE IT WILL ENTER OUR AREA SUNDAY AFTERNOON
BEFORE STALLING.
FOR FRIDAY AND SATURDAY...SPOTTY SHOWERS AND THUNDERSTORMS WILL
DEVELOP ACROSS THE MOUNTAINS EARLY BOTH AFTERNOONS...WITH COVERAGE
PEAKING DURING EARLY EVENING. CONVECTION WILL WEAKEN AND FADE AROUND
SUNSET WITH LOSS OF HEATING...BUT STILL EXPECT LIGHT SHOWER TO TWO
TO FLOAT ACROSS THE AREA OVERNIGHT. MAY SEE ONE OR TWO STORMS BECOME
STRONG...BUT THE BIGGER CONCERN IS LIGHT UPPER LEVEL WINDS/SLOW CELL
MOVEMENT...WHICH MAY RESULT IN LOCALLY HEAVY RAIN IF CELLS STALL OR
TRAIN. AFTERNOON HIGHS WILL RANGE FROM THE UPPER 70S AND LOW 80S
ACROSS THE MOUNTAINS...TO THE MID 80S ACROSS THE PIEDMONT. OVERNIGHT
LOWS WILL FALL INTO THE LOW/MID 60S.
EXPECT GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY AS
THE COLD FRONT APPROACHES. WHILE THE UPPER LEVEL DYNAMICS STILL
APPEAR TO BE MARGINAL...INCREASED CONVERGENCE IN THE LOW LEVELS
SHOULD BE ENOUGH TO SUPPORT A SLIGHTLY BETTER CHANCE OF STRONG
STORMS DURING THE AFTERNOON AND EVENING...PERHAPS WITH A FEW STORMS
BECOMING SEVERE. THE COLD FRONT WILL ENTER THE INTERSTATE 64
CORRIDOR BY EARLY EVENING...AND EVENTUALLY STALL SOMEWHERE ACROSS
OUR AREA FOR THE REMAINDER OF THE NIGHT...PROVIDING THE FOCUS FOR
SPOTTY SHOWERS INTO MONDAY MORNING. INCREASED CLOUDS WILL MAKE FOR
SLIGHTLY COOLER TEMPERATURES ACROSS THE MOUNTAINS...WITH HIGHS IN
THE MID/UPPER 70S...WHILE THE PIEDMONT WILL REACH THE UPPER 80S.
LOWS WILL BE IN THE UPPER 50S NEAR INTERSTATE 64...AND HOLD IN THE
MID 60S FURTHER SOUTH.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 500 AM EDT THURSDAY...
BY MONDAY...THE UPPER PATTERN WILL HAVE ESTABLISHED A SPLIT FLOW
REGIME ACROSS THE NORTHERN TIER OF STATES AS A CLOSED LOW DEVELOPS
OVER THE LOWER MISSISSIPPI VALLEY AND SLOWLY SINKS SOUTHWARD THROUGH
THE MIDDLE OF NEXT WEEK. SOME RIDGING WILL ALSO BE TAKING PLACE OVER
THE MID ATLANTIC REGION AND SET UP A SLUGGISH BLOCKY PATTERN.
AT THE SURFACE...HIGH PRESSURE PASSING EAST ACROSS THE GREAT LAKES
WILL SPREAD ACROSS THE NORTHEAST AND WEDGE DOWN THE EASTERN
SEABOARD...GIVE THE COLD FRONT A RENEWED PUSH THROUGH OUR AREA. THE
HIGH WILL BRING COOLER/NEAR NORMAL TEMPERATURES TO THE REGION.
HOWEVER...THE PATTERN WILL KEEP US MOIST WITH DEEP SOUTHEASTERLY
FLOW AND EXPECT ENOUGH FORCING BETWEEN OROGRAPHIC UPSLOPE AND
DIURNAL EFFECTS TO KEEP SOME SHOWER ACTIVITY...AND POSSIBLY A
THUNDERSTORM...IN THE FORECAST THROUGH THE PERIOD.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
AS OF 200 AM EDT THURSDAY...
PATCHY FOG THIS MORNING...OTHERWISE VFR ANTICIPATED THROUGH FIRST
HALF OF THE DAY THURSDAY. DAYTIME HEATING...IN ADDITION TO SOME
LIFT FROM APPROACHING FRONT OVER THE OHIO VALLEY AND VORTICITY
ASSOCIATED WITH CONVECTIVE DEBRIS MOVING NORTH FROM THE SOUTHERN
APPALACHIANS...SHOULD RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE MID/LATE AFTERNOON AND EVENING. MESOSCALE
MODELS FOCUS THE GREATEST COVERAGE BETWEEN 20Z/3PM AND
01Z/9PM...AND MAINLY ACROSS THE MOUNTAINS ALONG AND WEST OF THE
BLUE RIDGE. MEAN WINDS FROM SFC-20KFT ARE FCST TO BE LESS THAN 10
KTS...SO SHOWERS/STORMS THAT DEVELOP SHOULD BE SLOW MOVING.
SURFACE WINDS THROUGH THE TAF VALID PERIOD WILL BE LIGHT AND
VARIABLE...SPEEDS MOSTLY 7KTS OR LESS.
EXTENDED AVIATION DISCUSSION...
THROUGH THE UPCOMING WEEKEND...A MOIST UNSTABLE AIR MASS WILL
REMAIN IN PLACE ACROSS THE REGION WITH ONLY WEAK FORCING. THIS
WILL RESULT IN MAINLY SLOW MOVING DIURNALLY DRIVE DEEP CONVECTION
DURING THE AFTERNOON AND EVENING HOURS FOLLOWED BY STABLE
CONDITIONS AT NIGHT. A FRONTAL SYSTEM WILL APPROACH FROM THE
NORTH DURING THE WEEKEND...BUT WILL LIKELY REMAIN WELL NORTH OF
THE FORECAST AREA THROUGH SUNDAY. THUS...NO CHANGE IN AIR MASS IS
EXPECTED THROUGH THE PERIOD.
WITH MOIST/STABLE CONDITIONS AT NIGHT...PATCHY LATE NIGHT/EARLY
MORNING LOW CLOUDS/FOG AND ASSOCIATED IFR-LIFR CIGS/VSBYS WILL BE
POSSIBLE EACH MORNING...BUT LIMITED TO A FEW HOURS BEFORE DAYBREAK
AND QUICKLY BURNING OFF AFTER SUNRISE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...PM
SHORT TERM...NF
LONG TERM...MBS/NF
AVIATION...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
601 AM EDT THU MAY 28 2015
.SYNOPSIS...
HIGH PRESSURE IS CENTERED OFF THE SOUTHEAST ATLANTIC COAST AND WILL
MAINTAIN A BROAD SOUTHERLY FLOW OF MOISTURE INTO THE REGION
THROUGH THE REMAINDER OF THIS WEEK...A PATTERN THAT WILL FEATURE
WARM/HUMID SUMMERLIKE CONDITIONS. IN ADDITION TO THE HEAT/HUMIDITY...
THERE WILL BE A DAILY THREAT OF SCATTERED SHOWERS/STORMS. FOR
TODAY THE STORM POTENTIAL WILL BE MOST PRONOUNCED ALONG A WEAK
COLD FRONT THAT WILL BE APPROACHING THE AREA FROM THE NORTHWEST.
ADDITIONAL SHOWERS/STORMS WILL ACCOMPANY AN UPPER LEVEL
DISTURBANCE THAT WILL BE MOVING NORTHEAST THROUGH THE TENNESSEE
VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 530 AM EDT THURSDAY...
A WEAK COLD FRONT EXTENDS FROM WESTERN NEW YORK INTO THE OHIO
VALLEY. THIS FRONT WILL MOVE SOUTHEAST INTO THE VA/WV HIGHLANDS
TODAY BEFORE DISSIPATING OVER THE REGION TONIGHT. IN ADDITION TO
THE FRONT...AN UPPER LEVEL DISTURBANCE WILL BE MOVING NORTHEAST
THROUGH THE TENNESSEE VALLEY...AND WILL INTERACT WITH THE
APPROACHING SURFACE FRONT TO PROVIDE LIFT FOR SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING. BEST COVERAGE OF
SHOWERS/STORMS TODAY WILL BE ACROSS THE MOUNTAINS WEST OF THE BLUE
RIDGE. STEERING WINDS ARE WEAK...SFC-20KFT MEAN FLOW OF 10KTS OR
LESS. THIS SUGGESTS ANY ACTIVITY THAT DEVELOPS TODAY WILL BE SLOW
MOVING AND WILL PROLONG THE HEAVIER SHOWERS ONCE THEY DEVELOP.
BOTH THE HIGH RES-WRF AND HRRR INDICATE THAT SHOWERS WILL BEGIN TO
DEVELOP OVER OUR MTNS AROUND MID-DAY...BECOMING MOST PRONOUNCED
BETWEEN 20Z/3PM AND SUNSET 01Z/9PM.
THE OVERALL THREAT FOR WIDESPREAD HAZARDOUS IS LOW...HOWEVER WITH
PRESENCE OF THE UPPER LEVEL DISTURBANCE...CAN`T RULE OUT SOME
PULSE SEVERE STORMS THIS AFTERNOON. MODEL FORECAST CAPE OF 2500
J/KG COUPLED WITH FORECAST DCAPE OF 1000 MAY BE ENOUGH FOR SOME
ISOLATED MICROBURSTS.
TEMPERATURES TODAY WILL BE SUMMER-LIKE WITH HIGHS IN THE
80S...COMPLIMENTED BY DEWPOINTS IN THE U50S-LOWER 60S.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 500 AM EDT THURSDAY...
UPPER LEVEL RIDGING WILL REMAIN IN PLACE ALONG THE EAST COAST ON
FRIDAY...BUT WILL SLOWLY BREAK DOWN DURING THE WEEKEND...GIVING WAY
TO A FLATTENING...MORE ZONAL PATTERN AS AN UPPER LEVEL TROUGH SHIFTS
ACROSS EASTERN CANADA. THE PASSAGE OF THIS TROUGH WILL PUSH A COLD
FRONT SOUTHWARD...WHERE IT WILL ENTER OUR AREA SUNDAY AFTERNOON
BEFORE STALLING.
FOR FRIDAY AND SATURDAY...SPOTTY SHOWERS AND THUNDERSTORMS WILL
DEVELOP ACROSS THE MOUNTAINS EARLY BOTH AFTERNOONS...WITH COVERAGE
PEAKING DURING EARLY EVENING. CONVECTION WILL WEAKEN AND FADE AROUND
SUNSET WITH LOSS OF HEATING...BUT STILL EXPECT LIGHT SHOWER TO TWO
TO FLOAT ACROSS THE AREA OVERNIGHT. MAY SEE ONE OR TWO STORMS BECOME
STRONG...BUT THE BIGGER CONCERN IS LIGHT UPPER LEVEL WINDS/SLOW CELL
MOVEMENT...WHICH MAY RESULT IN LOCALLY HEAVY RAIN IF CELLS STALL OR
TRAIN. AFTERNOON HIGHS WILL RANGE FROM THE UPPER 70S AND LOW 80S
ACROSS THE MOUNTAINS...TO THE MID 80S ACROSS THE PIEDMONT. OVERNIGHT
LOWS WILL FALL INTO THE LOW/MID 60S.
EXPECT GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS ON SUNDAY AS
THE COLD FRONT APPROACHES. WHILE THE UPPER LEVEL DYNAMICS STILL
APPEAR TO BE MARGINAL...INCREASED CONVERGENCE IN THE LOW LEVELS
SHOULD BE ENOUGH TO SUPPORT A SLIGHTLY BETTER CHANCE OF STRONG
STORMS DURING THE AFTERNOON AND EVENING...PERHAPS WITH A FEW STORMS
BECOMING SEVERE. THE COLD FRONT WILL ENTER THE INTERSTATE 64
CORRIDOR BY EARLY EVENING...AND EVENTUALLY STALL SOMEWHERE ACROSS
OUR AREA FOR THE REMAINDER OF THE NIGHT...PROVIDING THE FOCUS FOR
SPOTTY SHOWERS INTO MONDAY MORNING. INCREASED CLOUDS WILL MAKE FOR
SLIGHTLY COOLER TEMPERATURES ACROSS THE MOUNTAINS...WITH HIGHS IN
THE MID/UPPER 70S...WHILE THE PIEDMONT WILL REACH THE UPPER 80S.
LOWS WILL BE IN THE UPPER 50S NEAR INTERSTATE 64...AND HOLD IN THE
MID 60S FURTHER SOUTH.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 500 AM EDT THURSDAY...
BY MONDAY...THE UPPER PATTERN WILL HAVE ESTABLISHED A SPLIT FLOW
REGIME ACROSS THE NORTHERN TIER OF STATES AS A CLOSED LOW DEVELOPS
OVER THE LOWER MISSISSIPPI VALLEY AND SLOWLY SINKS SOUTHWARD THROUGH
THE MIDDLE OF NEXT WEEK. SOME RIDGING WILL ALSO BE TAKING PLACE OVER
THE MID ATLANTIC REGION AND SET UP A SLUGGISH BLOCKY PATTERN.
AT THE SURFACE...HIGH PRESSURE PASSING EAST ACROSS THE GREAT LAKES
WILL SPREAD ACROSS THE NORTHEAST AND WEDGE DOWN THE EASTERN
SEABOARD...GIVE THE COLD FRONT A RENEWED PUSH THROUGH OUR AREA. THE
HIGH WILL BRING COOLER/NEAR NORMAL TEMPERATURES TO THE REGION.
HOWEVER...THE PATTERN WILL KEEP US MOIST WITH DEEP SOUTHEASTERLY
FLOW AND EXPECT ENOUGH FORCING BETWEEN OROGRAPHIC UPSLOPE AND
DIURNAL EFFECTS TO KEEP SOME SHOWER ACTIVITY...AND POSSIBLY A
THUNDERSTORM...IN THE FORECAST THROUGH THE PERIOD.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
AS OF 200 AM EDT THURSDAY...
PATCHY FOG THIS MORNING...OTHERWISE VFR ANTICIPATED THROUGH FIRST
HALF OF THE DAY THURSDAY. DAYTIME HEATING...IN ADDITION TO SOME
LIFT FROM APPROACHING FRONT OVER THE OHIO VALLEY AND VORTICITY
ASSOCIATED WITH CONVECTIVE DEBRIS MOVING NORTH FROM THE SOUTHERN
APPALACHIANS...SHOULD RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE MID/LATE AFTERNOON AND EVENING. MESOSCALE
MODELS FOCUS THE GREATEST COVERAGE BETWEEN 20Z/3PM AND
01Z/9PM...AND MAINLY ACROSS THE MOUNTAINS ALONG AND WEST OF THE
BLUE RIDGE. MEAN WINDS FROM SFC-20KFT ARE FCST TO BE LESS THAN 10
KTS...SO SHOWERS/STORMS THAT DEVELOP SHOULD BE SLOW MOVING.
SURFACE WINDS THROUGH THE TAF VALID PERIOD WILL BE LIGHT AND
VARIABLE...SPEEDS MOSTLY 7KTS OR LESS.
EXTENDED AVIATION DISCUSSION...
THROUGH THE UPCOMING WEEKEND...A MOIST UNSTABLE AIR MASS WILL
REMAIN IN PLACE ACROSS THE REGION WITH ONLY WEAK FORCING. THIS
WILL RESULT IN MAINLY SLOW MOVING DIURNALLY DRIVE DEEP CONVECTION
DURING THE AFTERNOON AND EVENING HOURS FOLLOWED BY STABLE
CONDITIONS AT NIGHT. A FRONTAL SYSTEM WILL APPROACH FROM THE
NORTH DURING THE WEEKEND...BUT WILL LIKELY REMAIN WELL NORTH OF
THE FORECAST AREA THROUGH SUNDAY. THUS...NO CHANGE IN AIR MASS IS
EXPECTED THROUGH THE PERIOD.
WITH MOIST/STABLE CONDITIONS AT NIGHT...PATCHY LATE NIGHT/EARLY
MORNING LOW CLOUDS/FOG AND ASSOCIATED IFR-LIFR CIGS/VSBYS WILL BE
POSSIBLE EACH MORNING...BUT LIMITED TO A FEW HOURS BEFORE DAYBREAK
AND QUICKLY BURNING OFF AFTER SUNRISE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...PM
SHORT TERM...NF
LONG TERM...MBS/NF
AVIATION...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
210 AM EDT THU MAY 28 2015
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL MAINTAIN A BROAD
SOUTHERLY FLOW OF MOISTURE INTO THE REGION THROUGH THE REMAINDER
OF THIS WEEK. A WEAK UPPER LEVEL DISTURBANCE AND ASSOCIATED
FRONTAL BOUNDARY WILL SLIDE INTO THE REGION EARLY THURSDAY. THIS
WEATHER FEATURE IN COMBINATION WITH DAYTIME HEATING AND
INSTABILITY WILL RESULT IN PERIODIC ROUNDS OF SHOWERS AND STORMS
OVER THE NEXT FEW DAYS.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 926 PM EDT WEDNESDAY...
SHOWERS AND THUNDERSTORMS LOCATED TO OUR SOUTHEAST FROM RALEIGH
NORTH CAROLINA TO EMPORIA VIRGINIA WHICH DEVELOPED ALONG OUTFLOW
BOUNDARIES AND IN THE AREAS OF RICHER CAPE ABOVE 1K AND STRONG
THETAE/ADVECTION ARE MOVING NORTHEAST AND WILL MISS THE EASTERN
COUNTIES OF OUR FORECAST AREA DURING THE NEXT HOUR OR TWO.
ISOLATED SHOWERS HAVE FORMED IN THE WESTERN MOUNTAINS AND ENDED
QUICKLY WITH THE MORE STABLE AIR. WE WILL HAVE TO WATCH NEXT
COUPLE OF HOURS TO SEE IF ANY CONVECTION TO OUR WEST IN EASTERN
TENNESSEE AND KENTUCKY SURVIVES ITS MARCH EASTWARD INTO THE
STABLE AIR ACROSS THE WESTERN MOUNTAINS. HOWEVER...WITH THE LOSS
OF SOLAR HEATING MOST OF THE CONVECTION WILL WEAKEN AND DISSIPATE
THIS EVENING INTO TONIGHT. UNDER PARTLY CLOUDY SKIES EXPECT
ANOTHER MILD OVERNIGHT WITH LOW TEMPERATURES FROM THE UPPER 50S IN
THE MOUNTAINS TO THE MID 60S IN THE PIEDMONT.
LINGERING BOUNDARIES AND MCVS FROM UPSTREAM CONVECTION SHOULD
PROVIDE FOR BETTER COVERAGE OF CONVECTION THURSDAY AFTERNOON.
THE SWODY2 (CONVECTIVE OUTLOOK DAY 2 FOR SEVERE POTENTIAL) KEEPS
OUR AREA IN THE GENERAL THUNDERSTORMS. WITH WEAK STEERING FLOW AND
WELL ABOVE AVERAGE PRECIP WATER VALUES EXPECTED...LOCALLY HEAVY
RAIN WILL BE POSSIBLE WITH TRAINING OR STORMS LOCKED ON TERRAIN.
HIGH TEMPERATURES WILL RANGE FROM THE MID 70S IN THE MOUNTAINS TO
THE UPPER 80S IN THE PIEDMONT.
AS OF 630 PM EDT WEDNESDAY...
MADE SOME ADJUSTMENTS TO POPS FOR THIS EVENING INTO TONIGHT.
USED A BLEND OF HRRR AND RNK WRFARW. DRIER AIR PUSHING IN FROM
THE WEST...WAS HINDERING THUNDERSTORM DEVELOPMENT. GIVEN LIMITED
INSTABILITY EXPECTED CONVECTION TO DIMINISH WITH THE LOSS OF SOLAR
HEATING THIS EVENING. LOW TEMPERATURES WILL BE MILD OVERNIGHT WITH
READINGS FROM AROUND 60 DEGREES IN THE MOUNTAINS TO THE MID 60S
IN THE PIEDMONT.
AS OF 350 PM EDT WEDNESDAY...
CONVECTION STRUGGLING TO GET GOING SO FAR THIS AFTERNOON AND WILL
LIKELY REMAIN ISOLATED THROUGH THIS EVENING...MAINLY IN MTNS AND
FOOTHILLS...GIVEN LIMITED INSTABILITY AND DRIER AIR PUSHING IN FROM
THE WEST BEHIND THE WEAK SHORT WAVE THAT HAS LIFTED NORTHEAST OVER
THE NORTHEAST U.S. ANY WIDELY SCATTERED CONVECTION THAT DOES
MANAGE TO DEVELOP THE REMAINDER OF THE AFTERNOON SHOULD DIMINISH
QUICKLY WITH LOSS OF HEATING. WILL NEED KEEP AN EYE ON MORE
ORGANIZED CONVECTION WELL TO THE WEST AS IT MOVES INTO EASTERN KY
AND TN...BUT ALL INDICATIONS ARE THAT THIS WILL DIE QUICKLY WELL
BEFORE IT REACHES WESTERN SLOPES OF APPALACHIANS...WHICH WOULD BE
NEAR MIDNIGHT IF IT DID SURVIVE. KEEPING A SLIGHT CHANCE POP IN
THE WEST FOR THIS SMALL POSSIBILITY... AS WELL AS ALONG BLUE RIDGE
MAINLY IN NW NC GIVEN SOME LINGERING INSTABILITY AND CONVERGENCE
PER THE HRRR...BUT OTHERWISE DROPPING POPS AFTER MIDNIGHT.
SOME SUGGESTION IN THE GUIDANCE THAT PATCHY FOG MAY BE MORE LIKELY
LATE TONIGHT...BUT WITH GENERAL LACK OF RAINFALL EXPECTED REMAINDER
OF THE DAY...AND SOME RESIDUAL MID DECK OVERNIGHT...THINK THIS IS
NOT LIKELY AND HAVE CHOSEN NOT TO INCLUDE IT.
FOR THURSDAY...WE FINALLY HAVE SOME INGREDIENTS COMING TOGETHER TO
SUPPORT MORE WIDESPREAD COVERAGE OF CONVECTION...WITH WEAK UPPER
WAVE MOVING INTO APPALACHIANS EARLY IN THE DAY AND ASSOCIATED WEAK
FRONTAL BOUNDARY...OR REALLY MORE OF A TROUGH AXIS...WHICH WILL ADD
TO SOME WEAK CONVERGENCE ALREADY GEOGRAPHICALLY FAVORED NEAR THE
BLUE RIDGE. MODELS SUGGEST MODEST INSTABILITY IN PART BECAUSE OF
WARMER AFTERNOON TEMPS EXPECTED...BUT STILL NOTHING SUPER
IMPRESSIVE...AND PERHAPS ENOUGH DRY AIR AT MID LEVELS TO SUPPORT
SOME GUSTY DOWNDRAFTS. AT THIS POINT THINK SEVERE POTENTIAL IS
LIMITED...BUT MUCH BETTER THAN THE LAST COUPLE OF DAYS. HOWEVER WITH
WEAKER STEERING FLOW AND WELL ABOVE AVERAGE PRECIP WATER VALUES
EXPECTED...LOCALLY HEAVY RAIN WILL BE THE MAIN CONCERN. GIVEN DRY
ANTECEDENT CONDITIONS...NOT ALL THAT CONCERNED ABOUT A FLASH FLOOD
THREAT...BUT STILL SOMETHING TO KEEP AN EYE ON WITH ISOLATED AREAS
IF ANY STORMS BECOME LOCKED ON TERRAIN. THIS WILL STILL MAINLY BE
OVER THE MOUNTAINS...WITH COVERAGE JUSTIFYING SOME LIKELY POPS...BUT
STORMS MAY DRIFT INTO THE PIEDMONT BY LATE AFTERNOON...SO MID CHANCE
POPS BY LATE IN THE DAY THERE AS WELL.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 330 PM EDT WEDNESDAY...
UPPER PATTERN WILL BE IN TRANSITION DURING THE SHORT TERM WITH
FLATTENING OF THE EAST COAST RIDGE AND A TROF DEVELOPING INTO A CLOSED
LOW OVER THE MISSISSIPPI VALLEY. THIS WILL KEEP US IN A WEAKLY FORCED
WARM/MOIST/UNSTABLE ENVIRONMENT WITH A DIURNAL TREND AND MOUNTAIN BIAS
FOR SHOWERS/THUNDERSTORMS. A WEAK COLD FRONT WILL BE APPROACHING FROM
THE NORTHWEST BY THE WEEKEND BUT UNCERTAINTY WILL BE INCREASING AS
GUIDANCE DIFFERS IN HANDLING THE SPEED OF THIS FEATURE. BELIEVE THE
SCENARIO WILL LEAD TO INCREASING CHANCES FOR FOR CONVECTION DURING THE
LATTER PORTION OF THE WEEKEND. BIGGEST CONCERN WILL BE THE POSSIBILITY
OF LOCALLY HEAVY RAIN GIVEN PRECIPITABLE WATER VALUES OF 1.0 TO 1.5
INCHES ACROSS THE REGION. TEMPERATURES WILL REMAIN ABOVE NORMAL WITH
READINGS TRENDING UP A FEW DEGREES THROUGH THE WEEKEND... GENERALLY
LOOKING FOR MID/UPPER 80S EAST OF THE BLUE RIDGE LOWER 80S WEST WITH
THE USUAL COOLER READINGS AT THE HIGHER ELEVATIONS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 PM EDT WEDNESDAY...
BY SUNDAY NIGHT THE UPPER PATTERN WILL BE WELL ON ITS WAY TO DEVELOPING
A SPLIT FLOW REGIME ACROSS THE NORTHERN TIER OF STATES AS A CLOSED LOW
DEVELOPS OVER THE MISSISSIPPI VALLEY AND SLOWLY SINKS SOUTHWARD THROUGH
THE MIDDLE OF NEXT WEEK. SOME RIDGING WILL ALSO BE TAKING PLACE OVER
THE MID ATLANTIC REGION AND SET UP A SLUGGISH BLOCKY PATTERN. AT THE
SURFACE HIGH PRESSURE WILL BUILD THROUGH THE NORTHEAST AND WEDGE DOWN
THE EASTERN SEABOARD...BRINGING COOLER/NEAR NORMAL TEMPERATURES TO THE
REGION. HOWEVER...THE PATTERN WILL KEEP US MOIST WITH DEEP SOUTHEASTERLY
FLOW AND EXPECT ENOUGH FORCING BETWEEN OROGRAPHIC UPSLOPE AND DIURNAL
EFFECTS TO KEEP SOME SHOWER ACTIVITY...AND POSSIBLY A THUNDERSTORM...
IN THE FORECAST THROUGH THE PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 200 AM EDT THURSDAY...
PATCHY FOG THIS MORNING...OTHERWISE VFR ANTICIPATED THROUGH FIRST
HALF OF THE DAY THURSDAY. DAYTIME HEATING...IN ADDITION TO SOME
LIFT FROM APPROACHING FRONT OVER THE OHIO VALLEY AND VORTICITY
ASSOCIATED WITH CONVECTIVE DEBRIS MOVING NORTH FROM THE SOUTHERN
APPALACHIANS...SHOULD RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE MID/LATE AFTERNOON AND EVENING. MESOSCALE
MODELS FOCUS THE GREATEST COVERAGE BETWEEN 20Z/3PM AND
01Z/9PM...AND MAINLY ACROSS THE MOUNTAINS ALONG AND WEST OF THE
BLUE RIDGE. MEAN WINDS FROM SFC-20KFT ARE FCST TO BE LESS THAN 10
KTS...SO SHOWERS/STORMS THAT DEVELOP SHOULD BE SLOW MOVING.
SURFACE WINDS THROUGH THE TAF VALID PERIOD WILL BE LIGHT AND
VARIABLE...SPEEDS MOSTLY 7KTS OR LESS.
EXTENDED AVIATION DISCUSSION...
THROUGH THE UPCOMING WEEKEND...A MOIST UNSTABLE AIR MASS WILL
REMAIN IN PLACE ACROSS THE REGION WITH ONLY WEAK FORCING. THIS
WILL RESULT IN MAINLY SLOW MOVING DIURNALLY DRIVE DEEP CONVECTION
DURING THE AFTERNOON AND EVENING HOURS FOLLOWED BY STABLE
CONDITIONS AT NIGHT. A FRONTAL SYSTEM WILL APPROACH FROM THE
NORTH DURING THE WEEKEND...BUT WILL LIKELY REMAIN WELL NORTH OF
THE FORECAST AREA THROUGH SUNDAY. THUS...NO CHANGE IN AIR MASS IS
EXPECTED THROUGH THE PERIOD.
WITH MOIST/STABLE CONDITIONS AT NIGHT...PATCHY LATE NIGHT/EARLY
MORNING LOW CLOUDS/FOG AND ASSOCIATED IFR-LIFR CIGS/VSBYS WILL BE
POSSIBLE EACH MORNING...BUT LIMITED TO A FEW HOURS BEFORE DAYBREAK
AND QUICKLY BURNING OFF AFTER SUNRISE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM/SK
NEAR TERM...KK/SK
SHORT TERM...MBS
LONG TERM...MBS
AVIATION...PM
AREA FORECAST DISCUSSION
NWS PORTLAND
149 AM PDT THU MAY 28 2015
.SYNOPSIS...HIGH PRESSURE ALOFT WILL BE OVER THE FORECAST AREA
THROUGH SATURDAY. THE CLOSED UPPER LOW OVER CENTRAL IDAHO TONIGHT
WILL CONTINUE TO DRIFT SOUTHEAST TODAY. EXPECT A LITTLE MORE WARMING
TODAY...AND THEN INLAND DAYTIME TEMPERATURE SHOULD PEAK FRIDAY. THE
UPPER RIDGE STARTS TO FLATTEN SATURDAY. THE HIGHER CASCADES WILL
CONTINUE TO HAVE A SLIM THREAT OF LATE-DAY THUNDERSTORMS THE NEXT
COUPLE OF DAYS. THE NEXT UPPER LOW SWINGS CLOSER TO THE OREGON COAST
SUNDAY...RESULTING IN A LITTLE MORE COOLING BUT A BETTER CHANCE OF
CASCADE THUNDERSTORMS. A MUCH DEEPER MARINE LAYER IS EXPECTED OVER
THE AREA EARLY NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH SATURDAY...WATER VAPOR LOOP SHOWS ONE
UPPER LOW OVER CENTRAL IDAHO...AND A SECOND LOW NEAR 55N 131W. A 500
MB RIDGE AXIS EXTENDS BETWEEN 125W AND 130W. WATER VAPOR ALSO SHOWS A
DRY SLOT SLIDING SOUTH OVER VANCOUVER ISLAND AND THE WA COAST. ON THE
SMALLER SCALE...STRATUS HAS ALREADY REACHED KKLS AT 08Z. THE 975 MB
RH FORECAST FROM THE NAM VALID 09Z WAS A LITTLE BEHIND...SHOWING THE
90 PCT OR GREATER VALUES A LITTLE FURTHER WEST. MAIN FORECAST PROBLEM
FOR TODAY AND FRIDAY WILL BE THE POTENTIAL FOR THUNDERSTORMS FOR THE
HIGHER CASCADES. THE UPPER LOW THAT WAS CENTERED NEAR THE
OREGON...WASHINGTON...IDAHO TRIPLE-POINT 00Z THU WILL CONTINUE TO
SHIFT SOUTHEAST TODAY. THIS WILL ALLOW NORTHWEST FLOW ALOFT OVER THE
FORECAST AREA. HOWEVER...MODEL SOUNDINGS FOR A POINT NEAR SANTIAM
PASS...ESPECIALLY THE NAM...MAINTAIN SOME DEGREE OF INSTABILITY FROM
LATE-AFTERNOON THROUGH THE EVENING TODAY AND FRI. BELIEVE THE MODELS
MAY BE SLIGHTLY OVER-DOING THE LOW-LEVEL DEW POINTS...THUS GENERATING
HIGHER CAPE VALUES. ACTUALLY THINK THE BEST CHANCE FOR CONVECTION...
ALBEIT SLIM...WILL BE OVER THE HIGHER S WA CASCADES.
EXPECT A THINNER MARINE LAYER TODAY. THE 06Z NAM DOES NOT SHOW MARINE
STRATUS REACHING KPDX...ALTHOUGH THE HI-RES ARW DOES INDICATE STRATUS
GETTING TO NEAR MULTNOMAH FALLS BY 15Z. HI-RES MODEL ALSO SUGGESTING
THE BEACHES WILL REMAIN CLOUDY. MAY BE A SHORT PERIOD OF SCATTERED
SKY CONDITIONS LATE IN THE DAY FROM ABOUT KONP NORTHWARD. MODEL 850
MB TEMPS FORECAST TO BE AROUND 15C TODAY IN THE WILLAMETTE VALLEY...
UP ABOUT 1 DEG FROM WED. THIS SHOULD PUT THE INLAND VALLEYS IN THE
LOWER 80S. WARMEST DAY LOOKS TO BE FRI WITH A SLIGHTLY WARMER START.
THE UPPER RIDGE STARTS TO FLATTEN A BIT LATE FRI AS AN UPPER LOW OVER
NRN BRITISH COLUMBIA SLOWLY DRIFTS SOUTH.
LITTLE CHANGE SAT WITH 500 MB HIGH PRES REMAINING OVER THE AREA. A
SLIGHT AMPLIFICATION IN THE RIDGE SAT AFTERNOON DUE TO A DEVELOPING
LOW MODELS SHOW NEAR 34N 138W SAT AFTERNOON. THIS ALSO INDUCES
SLIGHTLY MORE UNSTABLE SWLY FLOW ALOFT INTO THE REGION. WILL LEAVE
THE SLIGHT THREAT OF THUNDERSTORMS FOR THE LANE COUNTY CASCADES SAT
AFTERNOON. WEISHAAR
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...WEAK SHORTWAVE
RIDGING MOVES THROUGH THE AREA EARLY SAT NIGHT WITH AN APPROACHING
UPPER LEVEL LOW PRESSURE SYSTEM NEARING 130W BY EARLY SUN. AS THIS
LOW PRESSURE TRACKS INLAND...INCREASING CLOUDS AND MUCH COOLER
TEMPERATURES MOVE INTO THE REGION. SHOWERS WILL BEGIN BY LATE SUN
AFTERNOON OR EVENING AS THE SURFACE BOUNDARY SLIDES ONSHORE AND
ACROSS THE REGION...WITH A CHANCE FOR THUNDERSTORMS IN THE CASCADES
SOUTH OF AROUND MT HOOD. AS THIS UPPER LOW CONTINUES TO TRACK ALONG
A GENERALLY SOUTHWEST TO EAST-NORTHEAST PATH ACROSS THE REGION AND
THEN EAST OF THE CASCADES...EXPECT CONTINUED RAIN CHANCES AND COOLER
WEATHER TO CONTINUE THROUGH AROUND MIDWEEK. WHILE SOME MODEST
DIFFERENCES IN PATTERN EVOLUTION BETWEEN MODEL SOLUTIONS SUGGEST A
BIT OF UNCERTAINTY IN LOCATION AND TIMING OF RAINFALL AMOUNTS...THE
MODEL GUIDANCE REMAINS IN REMARKABLY DECENT AGREEMENT WITH RESPECT
TO THE SHOWERY PATTERN ALONG WITH TEMPERATURES AT OR A FEW DEGREES
BELOW SEASONAL NORMALS.
&&
.AVIATION...VFR TODAY OVER MUCH OF THE REGION...WITH DRIER STABLE
N TO NW FLOW ALOFT. SHALLOW MARINE LAYER OVER THE PAC WILL KEEP
IFR STRATUS ON THE COAST JAMMED AGAINST THE COAST RANGE. TOPS
LIKELY IN 1000 TO 1200 FT RANGE. DO HAVE POCKETS OF STRATUS
EXTENDING INTO THE COAST RANGE AND UP THE COLUMBIA RIVER THIS
AM. STRATUS AT KKLS WILL CONTINUE PUSHING UPSTREAM...REACHING KPDX
AND KTTD ARUOND 12Z...THEN STRATUS WILL PUSH BIT MORE TO THE SOUTH
AGAINST THE CASCADES FOOTHILLS. BUT THOSE INLAND CLOUDS WILL BURN
OFF BETWEEN 16Z AND 18Z.
KPDX AND APPROACHES...VFR TODAY WITH DRY STABLE AIR MASS ALOFT.
LIKE WED AM...LOW STRATUS WITH CIGS NEAR 800 FT WILL ARRIVE FROM
THE N AROUND 12Z...BUT WILL BURN OUT BETWEEN 16Z AND 17Z. ROCKEY.
&&
.MARINE...NOT MUCH CHANGE OVERALL. HIGH PRES REMAINS LOCKED OVER
THE NE PAC...WITH WEAK PRES GRADIENTS. SEAS CONTINUE AS A MIX OF W
AND SW SWELL TRAINS...BUT OVERALL SEAS CONTINUE AROUND 5 TO 6 FT
THROUGH THE COMING WEEKEND.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
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
1020 PM PDT WED MAY 27 2015
.SYNOPSIS...
Scattered showers and thunderstorms decrease through sunset
Wednesday night, but the threat returns for the afternoon hours
on Thursday and Friday. However they will be more focused around
the mountains. Expect a warming trend into the weekend, with highs
in the 80s, with a lingering threat of mainly mountain showers
and thunderstorms. By next Monday and Tuesday the next best chance
of showers and thunderstorms arrives, with the potential for some
stronger storms and the return of cooler temperatures.
&&
.DISCUSSION...
Evening update: the shower and thunderstorm threat is largely on
the wane. However there disturbances continue to pivot around the
exiting upper low. WV imagery shows the center of that exiting low
around eastern Idaho county (in lower panhandle of Idaho) this
hour. However disturbance rounding the backside of that low will
continue to provide some shower threat through the night. One wave
is dropping across southeast WA now. Another couple wave are
pushing toward the US/BC border. These latter two waves and at
least some indication of elevated instability through the night,
as well as trends on the HRRR suggest keeping some shower threat
going through the night across the northern mountains,
Spokane/C`dA area and Panhandle mountains. Though after 09Z-10Z
(2-3 AM) this threat may be on the wane as the waves leave the
main pool of potential elevated instability. Either way, I
continued the threat of showers going into the overnight the
aforementioned locations. I`m not as confident that there could be
any nocturnal thunder mixed in, so I left it out.
The remainder of the forecast looks generally on track. Only minor
tweaks to the Thursday afternoon/evening shower chances. With the
flow turning from northwest to westerly through tonight into
tomorrow this should help hold the main shower chances in the
mountains and closer to the WA/ID border eastward, leaving much of
the Basin dry. Yet there is still enough to say there is some
threat in the Spokane area into the higher Palouse, again with the
best chance closer to the Idaho border. /J. Cote`
&&
.AVIATION...
06Z TAFS: Isolated -shra remain a threat tonight over the
NE TAF sites (GEG to COE) as a disturbance drops in from the
north, interacting with some elevated instability. The threat that
a shower may pass a TAF site is small. Behind the showers in the
morning there could be some patchy fog, but it should be shallow
and short-lived and may not impact TAF sites. Additional showers
and thunderstorms are expected in afternoon heating Thursday.
Confidence is highest around the mountains, but some may pass the
TAF sites too. In this latter region confidence is highest closer
to the ID border. The threat will wane again after dark Thursday
night. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 52 79 57 82 59 85 / 20 10 10 20 10 10
Coeur d`Alene 49 78 54 82 56 83 / 20 20 20 30 20 20
Pullman 46 75 52 82 56 83 / 20 20 20 20 20 20
Lewiston 52 83 58 88 63 90 / 20 10 10 20 20 20
Colville 53 82 54 83 54 86 / 20 20 20 30 20 20
Sandpoint 50 78 51 81 52 80 / 20 20 20 30 20 20
Kellogg 47 76 49 81 53 81 / 20 40 40 30 30 20
Moses Lake 53 86 58 90 59 92 / 20 10 10 10 10 10
Wenatchee 59 86 64 89 63 90 / 10 10 10 10 10 10
Omak 51 86 56 87 54 90 / 20 10 10 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1038 PM CDT FRI MAY 29 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 227 PM CDT FRI MAY 29 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG
COLD FRONT MOVING ACROSS NORTHWEST WISCONSIN EARLY THIS AFTERNOON.
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP AHEAD OF THE
FRONT WITH HELP FROM WEAK SHORTWAVES...ONE OVER SOUTHWEST
WISCONSIN...AND ANOTHER OVER SOUTHERN MINNESOTA. AS THE WAVE OVER
SOUTHEAST WISCONSIN LIFTS NORTHEAST...SCATTERED STORMS SHOULD SPREAD
ACROSS THE FOX VALLEY AND LAKE SHORE AREAS WHERE ML CAPES ARE
BUILDING TO GREATER THAN 400 J/KG. SHOWERS AND A FEW THUNDERSTORMS
WILL ALSO BECOME MORE WIDESPREAD OVER N-C WISCONSIN AHEAD OF THE
FRONT THIS AFTERNOON. GUSTY WINDS AND SMALL HAIL WILL BE POSSIBLE
WITHIN ANY STORMS...ALONG WITH A POTENTIAL QUICK INCH OF RAIN. WITH
A JUICY AIRMASS IN PLACE...PRECIP TRENDS AND AMOUNTS ARE THE MAIN
FORECAST CONCERNS AS THE FRONT SLOWLY MOVES ACROSS THE REGION.
TONIGHT...THE STRONG COLD FRONT WILL MOVE SOUTHEAST ACROSS CENTRAL
AND NORTHEAST WISCONSIN DURING THE EVENING. AHEAD OF THE
FRONT...SCATTERED SHOWERS AND THUNDERSTORMS WILL BE OCCURRING IN AN
AREA OF DIMINISHING INSTABILITY. IN ADDITION...THERE WILL BE A
MINIMUM OF SHEAR RIGHT AHEAD OF THE FRONT. SO POTENTIAL FOR ANY
SEVERE WEATHER REMAINS LOW...BUT GUSTY WINDS TO 40 MPH AND SMALL
HAIL LOOKS REASONABLE WITHIN ANY THUNDERSTORMS. BEHIND THE
FRONT...STRONG MID-LEVEL FGEN COMBINED WITH UPPER DIVERGENCE IN THE
RIGHT REAR QUAD OF AN UPPER JET...AND PWATS IN EXCESS OF 1.50 WILL
LEAD TO A BAND OF MODERATE TO HEAVY RAIN SLOWLY MOVING ACROSS THE
FORECAST AREA. THE SLOW MOVEMENT OF THE RAIN WITH SOME INTERACTION
FROM DAYTIME INSTABILITY LEADS ME TO THINK THE HIGHEST RAINFALL
TOTALS WILL BE ACROSS NORTH-CENTRAL WISCONSIN WHERE A WIDESPREAD
INCH...LOCALLY UP TO 2 INCHES WITHIN THUNDERSTORMS...COULD FALL.
ELSEWHERE...A WIDESPREAD HALF INCH TO INCH LOOKS REASONABLE. NORTH
WINDS WILL BECOME GUSTY LATE BEHIND THE FRONT AS COLDER AIR RUSHES
IN. LOWS RANGING FROM THE LOWER 40S NORTH TO MID 50S SOUTH.
SATURDAY...THOUGH THE FRONT WILL BE EXITING THE REGION BY THE START
OF SATURDAY MORNING...RIGHT REAR QUAD OF THE UPPER JET AND MID-LEVEL
FGEN WILL BE HANGING OVER EASTERN WISCONSIN. HAVE INCREASED PRECIP
CHANCES THERE FOR THE MORNING. MODELS ARE ALSO SLOWER EXITING
PRECIP IN THE AFTERNOON...AND HAVE KEPT A SMALL CHANCE OVER EAST-
CENTRAL WISCONSIN THROUGH 21Z. AS A COLD CANADIAN AIRMASS BUILDS
INTO THE REGION...TEMPERATURES WILL BE SIGNIFICANTLY COOLER THAN
TODAYS READINGS. WITH BLUSTERY CONDITIONS...HIGHS WILL RANGE FROM
THE MID 50S NORTH TO LOW 60S SOUTH.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 227 PM CDT FRI MAY 29 2015
THE POTENTIAL FROST AND FREEZE HEADLINES WILL BE THE PRIMARY
ISSUE THIS WEEKEND AS A VERY COOL DRY HIGH PRESSURE SYSTEM WILL
DRIFT OVER THE GREAT LAKES REGION IN THE WAKE OF A STRONG COLD
FRONT. NEXT PCPN CHANCES FOR NEXT WEEK WILL BE THE NEXT ISSUE AS
TEMPERATURES GRADUALLY WARM.
THE RIDGE AXIS OF THE A CANADIAN HIGH PRESSURE SYSTEM IS PROGGED
TO BE OVER NORTHERN WISCONSIN DURING THE LATE SATURDAY NIGHT
HOURS. THE LIGHT WINDS...CLEAR SKIES...DRY AIR AND H850 TEMPS LESS
THAN +2 C PROVIDE A LIKELY SCENARIO OF FROST OR FREEZING
TEMPERATURES. ANTICIPATE A HEADLINE WILL BE NEEDED IN THE NEXT 24
HOURS AFTER DEALING WITH THE STRONG COLD FRONT AND CONVECTION.
AIR MASS MAY STILL SUPPORT SOME FROST OVER THE FAR NORTHEAST
SUNDAY NIGHT BUT NOT AS WIDESPREAD.
TEMPERATURES WILL GRADUALLY WARM FOR THE START OF THE NEW WEEK AS
AN UPPER RIDGE SETTLES OVER THE GREAT LAKES REGION. THE CANADIAN
SURFACE HIGH WILL CONTINUE TO RIDGE INTO THE REGION WHILE THE RETURN
WARM AIR ADVECTION FLOW AND CHANCES OF CONVECTION IS PRIMARILY
CONFINED TO THE NORTHERN PLAINS IN THE SOUTHWEST FLOW OF A BROAD
UPPER TROUGH OVER THE WESTERN STATES. SOME DEBRIS CLOUDS FROM THIS
NORTHERN PLAINS CONVECTION MAY BE ABLE TO DRIFT INTO NORTHERN
WISCONSIN MONDAY AND TUESDAY TO AFFECT TEMPERATURES.
CONVECTION MAY BEGIN TO SPREAD INTO AT LEAST THE NORTHWEST PORTION
OF WISCONSIN ON WEDNESDAY AND THURSDAY WITH THE UPPER RIDGE
PROGGED TO SHIFT A BIT MORE EAST. RETURN FLOW 850 WARM AIR
ADVECTION CONTINUES TO INCREASE OVER THE NORTHERN PLAINS AS WELL
AS INTO THE FAR WESTERN GREAT LAKES REGION. EASTERN SECTIONS MAY
CONTINUE TO BE PROTECTED BY THE DEPARTING HIGH PRESSURE SYSTEM SO
HIGH PCPN CHANCES WILL BE CONFINED OVER THE NORTHWEST. PROGS IN
SOME AGREEMENT WITH THE UPPER RIDGE SUBSIDING AND A RETURN TO A
SOUTHWEST FLOW ALOFT AND PCPN CHANCES SPREADING EASTWARD LATE NEXT
WEEK.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1037 PM CDT FRI MAY 29 2015
LIGHT RAIN AND INSTRUMENT FLIGHT RULES CONDITIONS EXPECTED TONIGHT
THROUGH AROUND 15Z SATURDAY. THEN CLEARING SKIES AND GOOD FLYING
WEATHER EXPECTED THROUGH SUNDAY AND MONDAY.
RDM.
&&
.HYDROLOGY...
ISSUED AT 227 PM CDT FRI MAY 29 2015
MOST RIVERS LEVELS PRIOR TO THE NEXT ROUND OF RAIN TODAY/TONIGHT
WERE MAINLY STEADY OR SLOWLY FALLING. AN ANTICIPATED WIDESPREAD 1
INCH RAINFALL THROUGH SATURDAY MORNING WILL REVERSE THAT TREND
WITH SOME RIVERS LIKELY RISING TO NEAR FS AND PERHAPS A FEW
EXCEEDING INTO THE MINOR FS LEVELS BY SATURDAY MORNING. LOCALLY
HIGHER 2 INCHES AMOUNTS POSSIBLE WITH THUNDERSTORMS. ISOLATED TO
SCATTERED STORMS WITH LOCALLY HEAVY RAINFALL ANTICIPATED AHEAD OF
THE COLD FRONT THROUGH THIS EVENING. A MORE WIDESPREAD 1 INCH
RAINFALL IN THE WAKE OF THE COLD FRONT OR POST FRONTAL REGION...WITH
LOCALLY HIGHER AMOUNTS OF 2 INCHES DUE TO EMBEDDED STORMS.
TDH.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......RDM
HYDROLOGY......TDH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
937 PM CDT FRI MAY 29 2015
.UPDATE...
MID-LEVEL LAPSE RATES HAVE STEEPENED A BIT OVER EAST CENTRAL WI
THIS EVENING...BUT MUCH LESS STEEP OVER THE REST OF SRN WISCONSIN
LIMITING INSTABILITY FOR THUNDERSTORMS. STILL ONLY GETTING BRIEF
PULSE STORMS THAT DO NOT LAST LONG ENOUGH TO PRODUCE MUCH IF ANY
CLOUD TO GROUND LIGHTNING...AND ONLY A SHORT PERIOD OF IN-CLOUDLIGHTNING
WITH THE STRONGEST CELLS. HOWEVER WITH PRECIPITABLE WATER VALUES
OF 1.6 TO 1.7 INCHES...THE STRONGER CELLS ARE PRODUCING RAINFALL
RATES OF 3 TO 4 INCHES PER HOUR...WHICH CAN YIELD UP TO 1 INCH OF
RAINFALL OVER THE 15-20 MINUTES WHEN THEY DROP THEIR PRECIPITATION
CORES.
MOST OF THE FORECAST AREA WILL SEE SHOWERS AND A FEW THUNDERSTORMS
SPREAD ACROSS WITH THE SURFACE TROUGH/COLD FRONT OVERNIGHT TONIGHT
INTO SATURDAY MORNING. WITH THE CURRENT FRONT TIMING...EXPECT
24-HOUR HIGHS FOR SATURDAY TO BE JUST AFTER MIDNIGHT. TAKING INTO
ACCOUNT THE FASTER MOVEMENT DOWN THE LAKESHORE...THE DAYTIME
HIGHS FOR SATURDAY SHOULD BE AROUND 12Z...EXCEPT MAY BE A REBOUND
IN THE FAR WEST LATE IN THE AFTERNOON.
&&
.AVIATION/06Z TAFS/...
LOOK FOR VFR CONDITIONS TO CONTINUE UNTIL SCATTERED TO BROKEN
COVERAGE SHOWERS MOVE IN WITH THE SURFACE TROUGH/COLD
FRONT...REACHING KMSN BY 03Z...KUES AROUND 0530Z AND KMKE AND KENW
AROUND 06Z. WILL MAINLY SEE MVFR VSBYS UNTIL AROUND 09Z...THEN A
SHORT PERIOD OF MVFR CIGS RIGHT BEHIND THE FRONT FALLING TO IFR
LEVELS UNTIL MID-MORNING IN THE WESTERN CWA...BUT REMAINING BELOW
1K FT IN THE EAST WITH THE MOIST COOL ONSHORE FLOW UNTIL LATE
AFTERNOON.
&&
.MARINE...
NO CHANGES TO HEADLINES AT THIS TIME...BUT NEXT SHIFT WILL HAVE TO
ASSESS THE FULL 00Z DATA SET TO SEE IF THERE WILL BE A NEED FOR A
GALE WARNING. 01Z RAP FORECAST SOUNDINGS INDICATE ENOUGH MIXING TO
TAP 33 TO 39 KNOT WINDS AROUND 400 FT FROM THE LATE MORNING
THROUGH THE END OF THE MODEL RUN AT 19Z...WHICH ARE SIMILAR TO THE
18Z GFS WINDS AT THAT HEIGHT THOUGH STRONGER THAN THE 18Z NAM.
&&
.PREV DISCUSSION... /ISSUED 353 PM CDT FRI MAY 29 2015/
TONIGHT AND SATURDAY...FORECAST CONFIDENCE - HIGH.
ON AND OFF SHOWERS WITH A FEW STORMS WILL CONTINUE THIS AFTERNOON
AND OVERNIGHT. CURRENT ACTIVITY MAY WIND DOWN FOR A TIME LATER THIS
AFTERNOON...WITH MORE SHOWERS/STORMS MOVING IN FROM THE WEST IN THE
EVENING AND NIGHT HOURS AND A COLD FRONT DROPS SOUTHEAST INTO THE
AREA. THE COLD FRONT WILL MAKE IT DOWN TO ABOUT THE
MADISON/MILWAUKEE AREAS BY DAYBREAK SATURDAY...CROSSING THE WI/IL
BORDER EARLY MORNING. MORE SHOWERS AND MAYBE A COUPLE STORMS WILL
PERSIST THROUGH THE MORNING ON THE BACK SIDE OF THE SURFACE LOW AS
THE UPPER TROUGH MOVES THROUGH. MODELS HAVE SLOWED DOWN OVERALL...SO
RAISED POPS FOR TOMORROW. SHOULD SEE RAIN WIND DOWN NORTHWEST TO
SOUTHEAST LATE MORNING INTO THE AFTERNOON.
STILL A MARGINAL RISK FOR SEVERE STORMS PER SPC...THOUGH HAVE NOT
SEEN MUCH OF CONCERN SO FAR...AND INSTABILITY WILL GENERALLY
DECREASE THROUGH THE EVENING HOURS. SOMETHING TO KEEP AN EYE ON
THOUGH.
TEMPS WILL CRASH LATE TONIGHT INTO SATURDAY MORNING AS THE COLD
FRONT MOVES THROUGH...WITH A COOL SATURDAY IN STORE FOR SOUTHERN
WISCONSIN...ESPECIALLY NEAR LAKE MICHIGAN. LINGERING CLOUDY SKIES
AND BREEZY NORTH TO NORTHEAST WINDS WILL ADD A BIT MORE OF A CHILL
IN THE AIR AS WELL.
SATURDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE - HIGH.
LOW TO MID-LEVEL Q-VECTOR CONVERGENCE EXITS SOUTHEAST WI EARLY
SATURDAY EVENING AS BREEZY NORTHEAST WINDS CONTINUE TO FEED DRIER
AIR ACROSS SOUTHERN WISCONSIN. LINGERING EVENING CLOUDINESS SHOULD
CLEAR...SUCCUMBING TO DRY AIR ONSLAUGHT. A COOL NIGHT IS EXPECTED
WITH 925H TEMPS FALLING TO 4-5C. WITH CLEAR SKIES...OVERNIGHT TEMPS
WILL FALL INTO THE UPPER 30S TO LOWER 40S MOST AREAS. A FEW
SUSCEPTIBLE LOCATIONS WILL FALL INTO THE MIDDLE 30S. HOWEVER DUE TO
LINGERING BOUNDARY LAYER MIXING...NOT EXPECTING ANY FROST FORMATION
LATE SATURDAY NIGHT.
COOL AIR REMAINS IN PLACE THROUGH SUNDAY INTO SUNDAY NIGHT BEFORE
WARMING TREND COMMENCES. LIGHTER BOUNDARY LAYER WINDS AND CONTINUED
DRY ATMOSPHERE WILL ALLOW TEMPS TO FALL INTO THE MIDDLE 30S TO LOWER
40S SUNDAY NIGHT. PENDING AMOUNT OF UPSTREAM HIGH CLOUD COVER THAT
WORKS INTO SOUTHERN WI...MAY BE SOME PATCHY LATE NIGHT FROST IN
SUSCEPTIBLE AREAS SUNDAY NIGHT.
MONDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE - MEDIUM.
NO SURPRISES FROM 24 HOURS AGO. CENTRAL CONUS LARGE-SCALE RIDGING
EXPANDS INTO UPPER MIDWEST EARLY IN THE PERIOD RESULTING IN WARMING
TREND AND QUIET CONDITIONS THROUGH TUE. SOME CONCERN ABOUT
POTENTIAL SHORT WAVE MOVING EWD ACROSS CONUS/CANADIAN BORDER TUE
NIGHT AND WED. INCREASING SOUTHERLY WINDS WILL ALLOW COLUMN PWAT TO
INCREASE TO OVER 0.50 INCH. MEDIUM RANGE GUIDANCE DIVERGES ON
STRENGTH AND PLACEMENT OF THIS WAVE...WITH MORE CONSISTENT ECMWF
MUCH WEAKER THAN GFS AND GEM. MEDIUM RANGE GUIDANCE IN BETTER
AGREEMENT ON LARGE SCALE RIDGE RE-EXPANDING INTO THE UPPER MIDWEST
AROUND THURSDAY. STRONGER MID-LEVEL SHORT WAVE LOOKS TO FLATTEN
RIDGING ACROSS THE UPPER MIDWEST THU NIGHT AND FRI. HENCE THIS
PERIOD LOOKS TO HAVE BEST CHANCE FOR MORE WIDESPREAD CONVECTION.
DAYTIME TEMPERATURES WILL REMAIN ON THE WARM SIDE FOR MUCH OF THE
EXTENDED PERIOD. HOWEVER LAKESHORE AREAS WILL REMAIN COOLER DUE TO
A PROLONGED PERIOD OF S TO SE WINDS.
GFS 5-DAY 500H MEANS CONTINUE TO SHOW WEST TO SOUTHWEST STEERING
FLOW THROUGH THE FIRST WEEK OF JUNE AND ABOVE NORMAL HEIGHTS. HENCE
EXPECT WARMER THAN NORMAL TEMPS FOR MUCH OF THE PERIOD WITH GOOD
GROWING CONDITIONS AND LITTLE FROST THREAT.
AVIATION/00Z TAFS/...
CURRENT SHOWERS/STORMS MAY WIND DOWN FOR A TIME LATER THIS
AFTERNOON...WITH MORE CONVECTION MOVING IN FROM THE WEST IN THE
EVENING AND NIGHT HOURS AND A COLD FRONT DROPS SOUTHEAST INTO THE
AREA. THE COLD FRONT WILL MAKE IT DOWN TO ABOUT THE
MADISON/MILWAUKEE AREAS BY DAYBREAK SATURDAY...CROSSING THE WI/IL
BORDER EARLY MORNING. EXPECT A FAIRLY QUICK SHIFT AND INCREASE IN
THE WINDS AS THE FRONT MOVES THROUGH.
MORE SHOWERS AND MAYBE A COUPLE STORMS WILL PERSIST THROUGH THE
MORNING ON THE BACK SIDE OF THE SURFACE LOW AS THE UPPER TROUGH
MOVES THROUGH.
OUTSIDE OF MODERATE TO HEAVY RAINFALL...VFR CONDITIONS WILL LIKELY
PERSIST INTO THIS EVENING. EXPECT LOWER CIGS TO MOVE IN OVERNIGHT AS
THE COLD FRONT MOVES THROUGH. SHOULD SEE RAIN WIND DOWN NORTHWEST TO
SOUTHEAST LATE MORNING INTO THE AFTERNOON...WITH SLOWLY IMPROVING
CIGS AS DRIER AIR WORKS INTO THE AREA.
MARINE...
NORTH TO NORTHEAST WINDS WILL BECOME GUSTY SATURDAY MORNING BEHIND A
DEPARTING COLD FRONT. GUSTS TO 30 KNOTS ARE EXPECTED ON SATURDAY.
WINDS WILL EASE A BIT SATURDAY NIGHT AND SUNDAY...BUT THE PRESSURE
GRADIENT LOOKS TO BE TIGHT ENOUGH TO KEEP GUSTS TO 25 KNOTS GOING
THROUGH THE DAY SUNDAY. A SMALL CRAFT ADVISORY IS THUS BEING ISSUED
THIS AFTERNOON FOR SATURDAY THROUGH THE DAY SUNDAY.
MAY SEEM SOME FOG AT TIMES THIS EVENING INTO TONIGHT GIVEN THE MOIST
AIRMASS OVER THE COOLER WATERS. SO FAR THOUGH...THE NEARSHORE AREAS
SEEM TO BE REMAINING MAINLY FREE OF FOG. SOMETHING TO KEEP AN EYE ON
UNTIL THE COLD FRONT MOVES THROUGH LATE TONIGHT INTO SATURDAY
MORNING.
BEACHES...
HIGH SWIM RISK CONDITIONS ARE EXPECTED ON SATURDAY. STRONG NORTH TO
NORTHEAST WINDS WILL BRING LIFE THREATENING WAVES AND CURRENTS ALONG
THE LAKE MICHIGAN SHORE. A HAZARD IS NOT BEING ISSUED TO DUE COLD
AIR TEMPERATURES...BUT FOR THOSE THAT VENTURE OUT...IT IS ADVISED TO
STAY OUT OF THE WATER SATURDAY AND SATURDAY NIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 7 PM CDT SUNDAY FOR
LMZ643>646.
&&
$$
UPDATE...REM
TONIGHT/SATURDAY AND AVIATION/MARINE...DDV
SATURDAY NIGHT THROUGH FRIDAY...MBK
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 230 PM CDT THU MAY 28 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY
SHOW A SHORTWAVE TROUGH MOVING NORTHEAST OVER THE CENTRAL
PLAINS...AND ANOTHER UPPER LOW OVER THE CENTRAL ROCKIES. CLOSER TO
HOME...TEMPERATURES REACHED THEIR CONVECTIVE TEMPS EARLY THIS
AFTERNOON...WHICH COMBINED WITH A CONVERGENCE AXIS...HAS LED TO
SHOWER AND THUNDERSTORM DEVELOPMENT MAINLY OVER NORTH-CENTRAL
WISCONSIN. A FEW OTHER ISOLATED CELLS HAVE ALSO POPPED UP OVER
MARATHON AND WAUPACA COUNTIES. DEWPOINTS HAVE MIXED OUT INTO THE
40S AND MID 50S ACROSS THE NORTH...SO THINK THIS WILL HOLD THE
INTENSITY OF STORMS IN CHECK. BUT DEWPOINTS REMAIN IN THE 60S OVER
FAR NE WISCONSIN WHERE ML CAPES ARE SURPASSING 1000 J/KG...SO CANNOT
RULE OUT A NEAR SEVERE STORM DEVELOPING LATER THIS AFTERNOON.
BETWEEN ONGOING STORMS AND THE INCOMING PRECIP FROM THE CENTRAL
PLAINS SHORTWAVE...PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS
THROUGH TOMORROW.
TONIGHT...SHOWERS AND STORMS OVER NORTHERN WISCONSIN WILL DIMINISH
WITH THE LOSS OF DAYTIME HEATING BY MID-EVENING. FOLLOWING A BRIEF
PERIOD OF MOSTLY CLEAR SKIES...CLOUDS WILL BE ON THE INCREASE AGAIN
AHEAD OF A SHORTWAVE LIFTING NORTHEAST OUT OF THE CENTRAL PLAINS.
AS PWATS INCREASE TO 1.5 INCHES BY SUNRISE...CLOUDS WILL BE LOWERING
AND PRECIP WILL BE APPROACHING WOOD COUNTY BY 09Z. SHOWERS WITH
EMBEDDED THUNDESTORMS WILL THEN BE SPREADING NE ACROSS CENTRAL
WISCONSIN BY 12Z. ELEVATED INSTABILITY IS PRETTY MEAGER SO THE
THREAT OF SEVERE STORMS IS LOW. MIN TEMPS IN THE UPPER 50S TO LOWER
60S.
FRIDAY...AS THE SHORTWAVE TROUGH LIFTS NORTHEAST ACROSS THE
REGION...LOW PRESSURE WILL TRACKING OVER N-C WISCONSIN. SHOWERS AND
EMBEDDED STORMS WILL CONTINUE TO LIFT NORTHEAST INTO NORTHEAST
WISCONSIN DURING THE MORNING. THE MOST PERSISTENT RAINFALL SHOULD
OCCUR OVER THE NORTHWEST HALF OF THE CWA THROUGH THE DAY. IF ANY
BREAKS OCCUR OVER THE SOUTHEAST...PROGGED SOUNDINGS AND THE SREF
SHOW BETWEEN 500 AND 750 J/KG OF ML CAPE. THINK THE PROBABILITY OF
THESE CAPES OCCURRING IS LOW DUE TO THE RAINFALL...HOWEVER. BUT
WILL NOT KNOW THESE SORTS OF DETAILS UNTIL TRENDS EMERGE TOMORROW.
RAIN COOLED HIGHS NEAR 70 ACROSS THE NORTH....AND INTO THE UPPER 70S
OVER EAST-CENTRAL WI.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 230 PM CDT THU MAY 28 2015
AFTER A PERIOD OF SHOWERS AND STORMS THROUGH SATURDAY
MORNING...COOLER TEMPERATURES EXPECTED FOR THE REMAINDER OF THE
WEEKEND. BUILDING UPPER HEIGHTS FOR NEXT WEEK PROMISES A DRIER AND
MILDER PERIOD WITH PERHAPS ANOTHER CHANCE OF PCPN ARRIVING MID TO
LATE NEXT WEEK.
OVERNIGHT MODEL RUNS SLOWED DOWN THE FRONT...AND THE BLEND OF
TODAYS RUNS SO FAR HAVE NOT CHANGED FROM THAT TREND. WILL
CONTINUE TO HANG ONTO THE SATURDAY MORNING PCPN OVER MUCH OF EAST
CENTRAL WISCONSIN. OTHERWISE THE DYNAMICS HAVE NOT CHANGED WITH
THE COLD FRONT PASSAGE WHICH INCLUDES A HEALTHY 850 MB BAROCLINIC
ZONE...RRQ REGION OF THE UPPER JET...PWATS NEAR 1.50 AHEAD OF A
RELATIVELY SLOW SAGGING FRONT. A FEW MODELS ALSO PROG A SURFACE
WAVE TO MOVE ALONG THE FRONT FRIDAY NIGHT OR SATURDAY MORNING
WHICH WOULD NOT ONLY SLOW THE FRONT BUT COULD ALSO FOCUS HIGHER
RAINFALL AMOUNTS. STILL THE LIKELY RANGE OF A 1 TO 2 INCH AVERAGE
WIDESPREAD RAIN FROM FRIDAY INTO SATURDAY MORNING IS POSSIBLE.
IN THE WAKE OF THE COLD FRONT...A COOL HIGH PRESSURE SYSTEM WILL
DRIFT OVER THE NORTHERN GREAT LAKES REGION LATER SATURDAY INTO
SUNDAY. GUSTY NORTHEAST TO NORTH WINDS WILL USHER IN A MUCH COOLER
AND DRIER AIR MASS INTO THE REGION STARTING SATURDAY. UNDER
MAINLY CLEAR SKIES AND DIMINISHING E-NE WINDS...THE THREAT OF
FROST RETURNS OVER NORTHERN WISCONSIN CLOSER TO THE CENTER OF THE
HIGH PRESSURE SYSTEM. TEMPS MAY ALSO DIP BELOW THE FREEZING MARK
OVER THE FAR NORTH.
AFTER A COOL START SUNDAY...TEMPERATURES WILL BE ON THE INCREASE
FOR THE START OF THE NEW WORK WEEK AS AN UPPER RIDGE DRIFTS OVER
THE MID SECTION OF THE COUNTRY INCLUDING THE GREAT LAKES REGION.
NEXT CHANCE OF PCPN APPEARS TO BE TOWARD THE MIDDLE OR LATER HALF
OF NEXT WEEK AS TROUGH OF LOW PRESSURE APPROACHES FROM THE
NORTHERN AND CENTRAL PLAINS.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 230 PM CDT THU MAY 28 2015
FOG WILL LEAD TO QUITE VARIABLE AND LOCALLY VERY POOR FLIGHT
CONDITIONS EARLY THIS MORNING. BUT ONCE THAT BURNS OFF AFTER
SUNRISE...GENERALLY GOOD FLIGHT CONDITIONS ARE EXPECTED FOR THE
REST OF TDA AND MUCH OF TNGT...WITH THE EXCEPTION OF ANY ISOLD-SCT
SHRA/TSRA THAT DEVELOP THIS AFTN.
&&
.HYDROLOGY...
ISSUED AT 230 PM CDT THU MAY 28 2015
MOST OF THE FORECAST AREA WILL BE GETTING A NICE
PERIOD OF DRY WEATHER TODAY...BETWEEN THE PCPN FROM THE FIRST
HALF OF THE WEEK AND THE ANTICIPATED 1-2 INCH RAINS FRIDAY INTO
SATURDAY MORNING. SO LIKELY RUN OFF WILL MAINLY AFFECT CURRENT
MAIN STEM RIVERS...WHICH ARE RUNNING NEAR BANKFULL STAGE. LATEST
NCRFC FORECAST DATA SUGGESTS ONLY ONE LOCATION ON THE MENOMINEE
RIVER MAY RISE TO NEAR MINOR FLOOD STAGE FRIDAY MORNING SO NO
PLANS ON A AREAL FLOOD WATCH AT THIS TIME. ISSUED A FLOOD WARNING
FOR THIS LOCATION THURSDAY AFTERNOON. EVEN IF THE RIVER DOES NOT
REACH FS...ADDITIONAL RAINFALL FRIDAY INTO FRIDAY NIGHT MAY BE
ENOUGH TO EXCEED FS BY SATURDAY MORNING. WILL LIKELY REISSUE THE
ESF DUE TO THE EXPECTED RISE IN STREAMS AND RIVERS AGAIN BY
SATURDAY MORNING.
TDH.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......MPC
HYDROLOGY......TDH
AREA FORECAST DISCUSSION
NWS ALBANY NY
500 AM EDT SAT MAY 30 2015
.SYNOPSIS...
A COLD FRONT...WORKING ACROSS THE WESTERN GREAT LAKES...WILL
APPROACH OUR AREA BY TONIGHT. SCATTERED THUNDERSTORMS COULD BREAK
OUT AHEAD OF THIS FEATURE THIS AFTERNOON AND EVENING. THEN...AS THE
COLD FRONT REACHES OUR REGION...IT WILL STALL JUST TO THE SOUTH OF
ALBANY. WAVES OF LOW PRESSURE WILL RIDE ALONG THIS BOUNDARY LATE
TONIGHT THROUGH MONDAY WHICH COULD BRING A SOAKING RAINFALL TO THE
REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 445 AM EDT...RADARS STILL DEPICTED NO ACTIVITY ACROSS OUR
REGION. THE LATEST HRRR CONTINUES TO INSIST THAT SCATTERED TO
NUMEROUS SHOWERS WILL DEVELOP ACROSS THE MOHAWK VALLEY INTO THE
CAPITAL DISTRICT SHORTLY AFTER SUNRISE. THE LATEST RAP INDICATED THE
SAME IDEA...NOT AS AGGRESSIVE. BOTH OF THESE MODELS DID HINT AT SOME
THETA-RIDGING ACROSS THE AREA. MEANWHILE...THE 00Z AND 06Z NAM AND
GFS DID NOT HAVE THIS. AT THIS TIME WE LEANED AGAINST THIS HAPPENING
BUT WILL MONITOR TO SEE IF ANYTHING DOES.
THE NEAREST SHOWER ACTIVITY WAS UP ACROSS THE ST. LAWRENCE VALLEY
AND LAKE ONTARIO...OUT AHEAD OF STRONG COLD FRONT...WORKING INTO THE
WESTERN GREAT LAKES AND WESTERN PORTIONS OF THE OHIO VALLEY. THIS
FRONT WAS HEADING SOUTHEAST ABOUT 30 MPH.
ASSUMING NO SHOWERS DEVELOP IT SHOULD STAY MAINLY DRY THROUGH EARLY
MORNING. A FEW SHOWERS MIGHT WORK INTO THE ADIRONDACKS AND WE DO
HAVE SLIGHT CHANCES FOR THOSE AREAS STARTING BEFORE SUNRISE.
TEMPERATURES VARIED DEPENDING ON HOW MUCH OF A BREEZE TOOK PLACE AS
WELL AS CLOUDS. TEMPERATURES RANGED FROM THE UPPER 60S IN THE
IMMEDIATE CAPITAL REGION DUE TO A SOUTHERLY BREEZE AROUND 10
MPH...WHILE OTHER PLACES WERE CLOSER TO 60...OR EVEN IN THE UPPER
50S DUE TO THIN CLOUDS AND LITTLE OR NO WIND. TEMPERATURES WILL
LIKELY NOT FALL MUCH MORE BEFORE DAWN.
SOME AREAS WILL ACTUALLY ENJOY SOME MORNING SUNSHINE...BEFORE MID
LEVEL CLOUDS THICKEN AND CU DEVELOP. THERE WAS ALSO SOME STRATUS
WORKING INTO THE MID HUDSON VALLEY.
AS THE ATMOSPHERE HEATS UP...IT WILL BECOME UNSTABLE. MID LEVEL
LAPSE RATES LOOK MODEST (AROUND 5.5 C/KM). HOWEVER INSTABILITY WILL
RAMP UP TO ABOUT 1500 SBCAPES DURING THE AFTERNOON. WE EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS TO CROP UP...ESPECIALLY NORTH
AND WEST OF THE CAPITAL REGION. THE STORM PREDICTION CENTER HAS OUR
MOST OF OUR REGION IN MARGINAL WHICH MEANS SOME STRONG TO LOCALLY
SEVERE STORMS COULD HAPPEN LATER TODAY DUE TO INCREASING WINDS
ALOFT. WE WILL INTRODUCE ENHANCED WORDING FOR THUNDERSTORMS POSSIBLY
CONTAINING GUSTY WINDS. SOME HAIL IS POSSIBLE...BUT RIGHT NOW...WIND
APPEARS THE BIGGER THREAT.
THIS WILL BE THE LAST DAY OF THIS CURRENT WARM SPELL...WITH HIGHS IN
THE LOWER TO MID 80S IN THE VALLEYS...75-80 HIGHER TERRAIN.
THE WIND WILL BE OUT OF THE SOUTH AND BY AFTERNOON...MOST PLACES
WILL AVERAGE AROUND 10 MPH...WITH SOME GUSTS TO 20 MPH OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE AFOREMENTIONED COLD FRONT BE ACROSS THE SAINT LAWRENCE THIS
EVENING...AND WORK SOUTHWARD TOWARD THE CAPITAL REGION OVERNIGHT.
WITH AN INCREASING LOW LEVEL JET AND EVENTUALLY ANTICYLONICALLY
CURVED UPPER LEVEL JET ENTRANCE REGION...COMBINING WITH PWATS WELL
OVER 1.5 INCHES...THIS SET UP IS LOOKING MORE AND MORE LIKE A GOOD
BET TO BRING A SOAKING RAINFALL TO THE REGION THROUGH MONDAY.
NOW IT WILL PROBABLY NOT RAIN THE WHOLE TIME FRAME. INITIALLY IT
LOOKS LIKE A ROUND OF SHOWERS AND PERHAPS A FEW MORE EMBEDDED
THUNDERSTORMS TONIGHT RIGHT ALONG AND BEHIND THE COLD FRONT...AS IT
BECOMES PARALLEL TO THE SOUTHWEST FLOW ALOFT.
THERE MIGHT BE A REDUCTION IN SHOWERS ON SUNDAY AS ONE WAVE PASSES
BY. HOWEVER...IT LOOKS AS IF A STRONG WAVE OF LOW PRESSURE SHOULD
FORM BY LATE SUNDAY...TRACKING FROM THE SOUTHERN OHIO
VALLEY...WESTERN PA AND UP ACROSS NY STATE. THIS WILL BE THE BEST
SHOT OF STEADY RAIN...POSSIBLY MODERATE TO EVEN HEAVY AT TIMES
SUNDAY NIGHT INTO MONDAY.
IT WILL TURN NOTICEABLY CHILLIER BEHIND THE FRONT. THE FIRST AREAS
TO FEEL THIS WILL BE NORTH OF THE MOHAWK VALLEY SATURDAY NIGHT WHERE
TEMPERATURES WILL DROP INTO THE 50S...WHILE MUGGIER 60S WILL BE
COMMON FROM THE CAPITAL REGION SOUTHWARD.
SUNDAY...HIGH TEMPERATURES MIGHT HOLD IN THE MID OR UPPER 50S WELL
NORTH OF ALBANY...LOWER 60S IN THE CAPITAL REGION...STILL WARMER
SOUTH WHERE THE FRONT WILL LIKELY TO CLEAR UNTIL LATE IN THE DAY.
TEMPERATURES NEAR POUGHKEEPSIE WILL LIKELY POP INTO THE 70S.
MUCH COOLER EVERYWHERE ON MONDAY AS OUR REGION LOOKS TO REMAIN IN
THE COOL SECTORS...GENERALLY AROUND 70 SOUTH...LOWER TO MID 60S IN
AND AROUND THE CAPITAL REGION...60 OR LOWER NORTH. THESE VALUES ARE
MUCH CLOSER FOR THE 1ST DAY OF MAY AS OPPOSED TO THE FIRST DAY OF
JUNE.
TO THE SOUTH OF CAPITAL REGION...THERE COULD BE ENOUGH AFTERNOON
INSTABILITY FOR SOME THUNDERSTORM ACTIVITY ON SUNDAY AFTERNOON AS
THE FRONT CONTINUES TO WORK THROUGH.
CHECKING ANOMALIES...THE PWATS UP TO 1.75 INCHES CONTINUE TO BE 2-3
STANDARD DEVIATION ABOVE NORMAL. THE H850 SOUTHERLY COMPONENT REACHED
THE 1-2 STANDARD DEVIATION RANGE...AND THE 250 WIND (EAST WEST)
COMPONENT NEVER STRAYS THAT MUCH FROM NORMAL. THE 03Z SREFS AVERAGE
ABOUT 1.5 INCHES FOR ALBANY...WITH HIGHEST AMOUNTS AROUND 3.5
INCHES. THE 00Z GEFS WERE CONSIDERABLY HIGHER...AVERAGING AROUND 3
INCHES WITH MEMBERS AS HIGH AS 4 INCHES AND THE LOWEST VALUES AROUND
1.3 INCHES.
FOR NOW OUR QPF WAS BLEND OF THE GEFS/SREF. MORE ABOUT THE QPF CAN
BE FOUND IN OUR HYDROLOGY SECTION.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
EVEN THOUGH THE SURFACE WAVE AND HEAVIER RAINFALL WILL HAVE ALREADY
CLEARED THE REGION BY SUNRISE TUESDAY...WE CAN STILL EXPECT SOME
LINGERING SHOWERS TUESDAY DUE TO THE UPPER LOW THAT WILL BE MOVING
EASTWARD ACROSS SOUTHERN QUEBEC. SHOWER ACTIVITY WITH THIS FEATURE
WILL BE SCATTERED AT BEST...AND HAVE FORECAST POPS OF 40 TO 50
PERCENT TUESDAY MORNING...DECREASING TO 30 TO 40 PERCENT DURING THE
AFTERNOON. IT WILL BE PARTLY TO MOSTLY CLOUDY ON TUESDAY WITH HIGHS
IN THE UPPER 50S AND 60S.
TUESDAY NIGHT THROUGH FRIDAY LOOKS DRY AT THIS POINT WITH TEMPS
GRADUALLY RISING THROUGH THE PERIOD. A LARGE RIDGE OF HIGH PRESSURE
WILL BUILD ACROSS THE REGION. LOWS TUESDAY NIGHT WILL BE 40 TO 50.
HIGHS ON WEDNESDAY IN THE UPPER 60S TO LOWER 70S. LOWS WEDNESDAY
NIGHT IN THE UPPER 40S TO MID 50S. HIGHS THURSDAY IN THE 70S TO
LOWER 80S. LOWS THURSDAY NIGHT IN THE 50S. HIGHS FRIDAY IN THE MID
70S TO LOWER 80S.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
A HIGH PRESSURE RIDGE WILL MOVE OFF THE NEW ENGLAND COAST
BY SATURDAY MORNING. EXPECT MAINLY VFR CONDITIONS AT THE
KGFL/KALB/KPOU/KPSF TAF SITES THROUGH MOST OF SATURDAY WITH MAINLY
MID/HI CLOUDS AND SCT CUMULUS. THE EXCEPTION WILL BE EARLY THIS
MORNING (BETWEEN 08Z AND 12Z)...THERE IS THE POTENTIAL AT
KPSF/KPOU FOR SOME FOG AND A VFR STRATUS DECK SPREADING NORTHWARD
DUE TO MOISTURE OFF THE ATLANTIC. ANY MVFR VISIBILITIES AND
STRATUS DECK SHOULD MIX OUT BY SHORTLY AFTER 12Z. LATE IN THE DAY
ON SATURDAY THERE WILL BE SHOWERS ADVANCING ACROSS THE MOST OF THE
REGION AND HAVE PLACED VCSH IN THE TAFS AT KGFL/KALB/KPSF AFTER
21Z...AND INCLUDED A PROB30 GROUP FOR THUNDERSTORMS WITH IFR/MVFR
CONDITIONS BETWEEN 30/21Z-22Z AND 31/03Z-04Z. AT KPOU THE VCSH
STARTS AT 23Z WITH THE PROB30 GROUP FROM 30/23Z TO 31/05Z. AFTER
THE THREAT OF TSTMS...HAVE FORECAST CIGS/VSBYS LOWERING TO MVFR AT
KGFL/KALB/KPSF BETWEEN 03Z AND 04Z AS A MORE WIDESPREAD AREA OF
SHOWERS MOVES IN.
THROUGH A FEW HOURS AFTER SUNRISE...WINDS WILL BE LIGHT AND
VARIABLE OR CALM AT KGFL/KPOU/KPSF...AND SOUTH AROUND 10 KTS AT
KALB. DURING SATURDAY MORNING...SOUTH WINDS WILL PICK UP AT ALL
THE TAF SITES AND INCREASE TO 10 TO 15 KTS WITH GUSTS OF 20 TO 25
KTS DURING THE AFTERNOON AND EARLY SATURDAY EVENING. BY MIDNIGHT
WINDS WILL DECREASE TO AROUND 10 KTS...WITH SOME GUSTS OVER 15 KTS
AT KALB.
OUTLOOK...
LATE SAT NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA
SUN-MON AM: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
MON AFT-TUE: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
TUE NIGHT-WED: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
MOST AREAS WILL START OFF WITH HIGH RH VALUES TODAY...IN THE 75-90
PERCENT RANGE. RH VALUES WILL ONLY FALL TO AROUND 50 PERCENT THIS
AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON WITH ANY THUNDERSTORMS POSSIBLY CONTAINING GUSTY WINDS.
THE MOST NUMEROUS STORMS SHOULD BE NORTH AND WEST OF THE CAPITAL
REGION...LESS NUMEROUS SOUTH AND EAST OF THE CAPITAL REGION.
THEN...IT LOOKS AS IF A SOAKING RAIN IS LIKELY HAPPEN TONIGHT
THROUGH AT LEAST MONDAY. WHILE IT NOT BE RAINING ALL OF THIS
TIME...THERE IS POTENTIAL FOR MODERATE TO HEAVY RAINFALL AT TIMES.
IT IS ALMOST A CERTAINTY EVERYONE WILL END UP WITH WELL OVER A
QUARTER INCH OF RAINFALL...MOST AREAS LIKELY RECEIVING AROUND TWO
INCHES OF RAINFALL.
DRYING CONDITIONS ARE EXPECTED TUESDAY THROUGH THURSDAY AS THE RAINS
ARE REPLACED BY DRIER AND EVENTUALLY A RETURNS TO WARMER WEATHER.
&&
.HYDROLOGY...
A WIDESPREAD SIGNIFICANT RAINFALL AS COLD FRONT APPROACHES AND
SLOWLY MOVES ACROSS THE REGION AS A WAVE OF LOW PRESSURE MOVES ALONG
THE BOUNDARY. SHOWERS AND THUNDERSTORMS ARE EXPECTED MAINLY THIS
AFTERNOON INTO THE EVENING WELL AHEAD OF THE COLD FRONT. A WAVE OF
LOW PRESSURE WILL FORM ON THE BOUNDARY SLOWING ITS PROGRESS ACROSS
THE REGION AND RESULTING IN SHOWERS ACROSS THE REGION. AT THIS
TIME...A WIDESPREAD 1 TO 3 INCHES OF RAINFALL IS FORECAST THROUGH
MONDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE. HAVE ADDED MENTION TO
OUR HAZARDOUS WEATHER OUTLOOK THAT IF THE THREAT OF HEAVY RAINFALL
BECOMES MORE CERTAIN A FLOOD WATCH MAY BE ISSUED. ON THE OTHER
HAND...THIS WILL LIKELY BE BENEFICIAL RAINFALL SINCE MUCH OF OUR
REGION HAS ONLY SEEN ABOUT HALF ITS NORMAL RAINFALL SO FAR THIS
YEAR.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...HWJIV/GJM
FIRE WEATHER...HWJIV
HYDROLOGY...IAA/HWJIV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
158 AM EDT SAT MAY 30 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE ATLANTIC THROUGH SATURDAY
AFTERNOON. A COLD FRONT WILL APPROACH SATURDAY NIGHT...AND MOVE
THROUGH ON SUNDAY. THE FRONT WILL STALL JUST TO THE SOUTH AS WEAK
LOW PRESSURE RIDES ALONG IT. HIGH PRESSURE WILL THEN BUILD IN FROM
THE NORTH LATE TUESDAY INTO WEDNESDAY...AND SHIFT TO THE SOUTH
ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HAVE ISSUED A DENSE FOG ADVISORY FOR THE TWIN FORKS OF LONG ISLAND
AND NEW LONDON COUNTY CONNECTICUT AS FOG HAS EXPANDED AND SHOULD
REMAIN DENSE THROUGH JUST AFTER DAY BREAK.
THE CHALLENGE STILL REMAINS TO BE HOW MUCH FURTHER WEST/INLAND THE
FOG/STRATUS EXPANDS. FOR NOW HAVE KEPT THE FORECAST WORDING AS
PATCHY FOG WEST OF THE TWIN FORKS AND NEW LONDON COUNTY.
STRENGTHENING WINDS THOUGH OFF THE DECK MAY PRECLUDE WIDESPREAD
FOG DEVELOPMENT FURTHER WEST. HRRR AND NARRE CONTINUE TO SHOW
HIGHER PROBS OF VSBY BELOW 1 MILE OVER ERN ZONES...WHERE THE DENSE
FOG ADVISORY IS IN EFFECT. STRATUS SHOULD EXPAND TO AT LEAST THE
REST OF LONG ISLAND AND SOUTHERN CT BEFORE DAY BREAK WITH
RADIATIVE COOLING.
LOW TEMPS WILL BE IN THE UPPER 50S ACROSS ERN LONG ISLAND AND SE
CT...LOWER 60S MOST ELSEWHERE...AND MID 60S INVOF NYC.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
MORNING LOW CLOUDS SHOULD BE SLOW TO BURN OFF ESPECIALLY ACROSS
LONG ISLAND AND COASTAL CT. SFC RIDGING AND SOUTHERLY FLOW SHOULD
KEEP THE AIR MASS STABLE OVER MOST OF THE CWA FROM NYC EAST...
WHILE ENOUGH LATE DAY INSTABILITY MAY DEVELOP WELL NORTH/WEST OF
NYC AHEAD OF AN ADVANCING WEAK SHORTWAVE TO SPARK ISOLD-SCT
SHOWERS AND POSSIBLY A TSTM. AFTERNOON COASTAL SEA BREEZES WILL BE
ENHANCED BY A TIGHT PRESSURE GRADIENT...AND COULD AGAIN SEE GUSTS
20-30 MPH LATE IN THE AFTERNOON ESPECIALLY ACROSS LONG ISLAND.
HIGH TEMPS SHOULD BE 80-85 INLAND AND IN THE 70S ALONG THE COAST.
CONVECTIVE POTENTIAL SHOULD WANE SAT EVENING WITH LOSS OF DAYTIME
HEATING...THEN COULD SEE SCT SHOWERS AND POSSIBLY A TSTM LATE AT
NIGHT AS A COLD FRONT APPROACHES. PREFER SLIGHTLY SLOWER/DRIER
FRONTAL APPROACH PER NAM/ECMWF VS FASTER/WETTER GFS...AND SO HAVE
SCALED BACK GUIDANCE POP...WITH ONLY CHANCE LATE AT NIGHT MAINLY
INLAND. LOW TEMPS SHOULD BE IN THE LOWER AND MID 60S.
THERE IS A HIGH RISK OF RIP CURRENTS AT THE ATLANTIC BEACHES
SATURDAY. STRONGEST RIP CURRENTS WOULD OCCUR DURING THE AFTERNOON
AS THE SOUTHERLY WINDS INCREASE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
COLD FRONT SLOWLY CROSSES THROUGH THE CWA THROUGH ON SUNDAY WITH
SHOWERS BECOMING LIKELY. CAPE IS SUFFICIENT FOR A CHANCE OF
THUNDERSTORMS. WITH THE COLD FRONT BECOMING ALIGNED WITH THE UPPER
FLOW ALONG WITH A RELATIVELY SLOW STORM MOTION FORECAST...WILL NEED
TO KEEP AN EYE OUT FOR THE POTENTIAL OF TRAINING CELLS AND AT LEAST
MINOR URBANIZED/SMALL STREAM FLOODING DURING THE AFTERNOON AND
EVENING HOURS.
THE COLD FRONT STALLS TO OUR SOUTH...THEN A WAVE OF LOW PRESSURE
FORMS ALONG IT...PASSING OVER OR JUST SOUTH OF US ON TUESDAY. MODELS
DISAGREE ON HOW QUICKLY THIS HAPPENS WITH ECMWF CONTINUING TO BE THE
SLOWEST WITH THE PASSAGE. HAVE GONE WITH LIKELY POPS THROUGH MONDAY
NIGHT BEFORE TAPERING TO CHC ON TUESDAY. MIGHT EVENTUALLY NEED TO
INCREASE POPS FOR TUESDAY...ESPECIALLY OVER EASTERN ZONES. ELEVATED
CAPE WILL BE JUST SOUTH OF US...SO NO MENTION OF THUNDER FROM LATE
SUNDAY NIGHT THROUGH TUESDAY.
AFTER NEAR-NORMAL HIGHS ON SUNDAY...MONDAY AND TUESDAY SHOULD BE
BELOW NORMAL WITH RAIN/CLOUDS/ONSHORE FLOW.
WILL MAINTAIN A DRY FORECAST FOR WEDNESDAY...FAVORING THE MORE
PROGRESSIVE MODELS. HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING
LOW. HIGHER CONFIDENCE THAT THURSDAY WILL BE DRY WITH THE CENTER OF
THE HIGH PASSING THROUGH. TEMPS RETURNING TO NORMAL. FRIDAY LIKELY
REMAINS DRY AS WELL WITH THE HIGH OFFSHORE AND THE NEXT COLD FRONT
WELL OFF TO THE NW.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE REMAINS OFFSHORE THROUGH SATURDAY NIGHT WITH A COLD
FRONT APPROACHING FROM NORTHWEST. SOUTHERLY FLOW WILL PREVAIL
THROUGH THE FORECAST.
VFR AT THE BEGINNING OF THE FORECAST. LOW STRATUS...300 FT TO 500 FT
WAS ACROSS MUCH OF LONG ISLAND...AND SOUTHEASTERN COASTAL
CONNECTICUT.
IFR CEILINGS ARE EXPECTED ACROSS LONG ISLAND AND SOUTHEASTERN
COASTAL CONNECTICUT OVERNIGHT...WITH IFR CEILINGS INTO THE NYC AREA
TERMINALS FOR A TIME OVERNIGHT. IFR TO VLIFR VISIBILITIES IN FOG ARE
LIKELY EAST OF THE NYC TERMINALS WITH A CHANCE OF MARGINAL VFR
VISIBILITIES ELSEWHERE.
CONDITIONS IMPROVE TO VFR 13Z TOP 14Z. GUSTY SOUTHERLY WIND DEVELOPS
BY THIS AFTERNOON WITH GUSTS UP TO 25 KT POSSIBLE.
THERE WILL BE A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS FROM
LATE THIS AFTERNOON THROUGH TONIGHT NORTH AND WEST OF THE NYC AREA
TERMINALS WITH MARGINAL VFR CONDITIONS.
.OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.SATURDAY NIGHT-TUESDAY...THERE WILL BE A CHANCE OF MARGINAL VFR TO
IFR CEILINGS LATE AT NIGHT AND INTO THE MORNING...ESPECIALLY
SATURDAY NIGHT AND SUNDAY NIGHT. MARGINAL VFR TO IFR AT TIMES IN
SHOWERS AND THUNDERSTORMS.
.TUESDAY NIGHT...BECOMING VFR.
.WEDNESDAY...VFR.
&&
.MARINE...
POOR VSBYS FOR MANY AREAS TONIGHT IN FOG. DENSE FOG FOR SOME OF
THE WATERS IN EFFECT.
QUIET CONDS THROUGH EARLY SAT AFTERNOON. COASTAL SEA BREEZES
ENHANCED BY A TIGHTENING PRESSURE GRADIENT SHOULD THEN HELP
GENERATE FREQUENT GUSTS UP TO 25 KT ALONG THE NEAR SHORE WATERS
SOUTH OF LONG ISLAND LATE SAT AFTERNOON INTO SAT EVENING...SO HAVE
RAISED SCA FOR THE OCEAN AND THE SOUTH SHORE BAYS.
OCEAN SEAS MAY FLIRT WITH 5 FT LATE SAT AFTERNOON AND SAT NIGHT.
WITH SUSTAINED WINDS REMAINING MOSTLY 15 KT OR LESS HELD THEM
AT 4 FT.
SCA CONDS WILL PROBABLY BE ON THE OCEAN WATERS SUNDAY AND SUNDAY
NIGHT...HOWEVER THERE COULD BE AN EXTENDED PERIOD DURING THIS
TIME FRAME WHERE THE CRITERIA IS NOT BEING MET. E WINDS OTHERWISE
INCREASE ON MONDAY WITH SCA CONDS PROBABLE ON MOST OF THE WATERS.
WINDS THEN SUBSIDE ON TUESDAY...BUT A LINGERING SWELL MAY KEEP
OCEAN SEAS AT SCA LEVELS THROUGH THE DAY...AND PROBABLY THROUGH
MOST OF WED AS WELL.
&&
.HYDROLOGY...
FORECAST RAIN AMOUNTS FROM SUNDAY THROUGH MONDAY NIGHT CURRENTLY
RANGE FROM 1.5 TO 2.5 INCHES. AS USUAL...LOCALLY HIGHER AMOUNTS WILL
BE POSSIBLE DUE TO SCATTERED THUNDERSTORMS. THESE THUNDERSTORMS ARE
MORE LIKELY TO OCCUR SUNDAY AFTERNOON AND EVENING. THERE IS A THREAT
OF FLOODING...BUT MINOR URBAN/POOR DRAINAGE/SMALL STREAM FLOODING
WOULD BE MORE LIKELY. FLASH FLOODING IS NOT OUT OF THE QUESTION
SUNDAY AFTERNOON AND NIGHT...BUT CONFIDENCE IS NOT HIGH ENOUGH TO
INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK...ESPECIALLY WITH ANTECEDENT
DRY CONDITIONS FOR THE PAST MONTH OR SO.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR CTZ008-012.
NY...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR NYZ079-081.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ330-340-
345-350-353.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 11 PM EDT
THIS EVENING FOR ANZ345-350-353-355.
&&
$$
SYNOPSIS...JC/GOODMAN
NEAR TERM...GOODMAN/DS/PW
SHORT TERM...GOODMAN
LONG TERM...JC
AVIATION...MET
MARINE...JC/GOODMAN/PW
HYDROLOGY...JC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
100 AM EDT SAT MAY 30 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE ATLANTIC THROUGH SATURDAY
AFTERNOON. A COLD FRONT WILL APPROACH SATURDAY NIGHT...AND MOVE
THROUGH ON SUNDAY. THE FRONT WILL STALL JUST TO THE SOUTH AS WEAK
LOW PRESSURE RIDES ALONG IT. HIGH PRESSURE WILL THEN BUILD IN FROM
THE NORTH LATE TUESDAY INTO WEDNESDAY...AND SHIFT TO THE SOUTH
ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HAVE ISSUED A DENSE FOG ADVISORY FOR THE TWIN FORKS OF LONG ISLAND
AND NEW LONDON COUNTY CONNECTICUT AS FOG HAS EXPANDED AND SHOULD
REMAIN DENSE THROUGH JUST AFTER DAY BREAK.
THE CHALLENGE STILL REMAINS TO BE HOW MUCH FURTHER WEST/INLAND THE
FOG/STRATUS EXPANDS. FOR NOW HAVE KEPT THE FORECAST WORDING AS
PATCHY FOG WEST OF THE TWIN FORKS AND NEW LONDON COUNTY.
STRENGTHENING WINDS THOUGH OFF THE DECK MAY PRECLUDE WIDESPREAD
FOG DEVELOPMENT FURTHER WEST. HRRR AND NARRE CONTINUE TO SHOW
HIGHER PROBS OF VSBY BELOW 1 MILE OVER ERN ZONES...WHERE THE DENSE
FOG ADVISORY IS IN EFFECT. STRATUS SHOULD EXPAND TO AT LEAST THE
REST OF LONG ISLAND AND SOUTHERN CT BEFORE DAY BREAK WITH
RADIATIVE COOLING.
LOW TEMPS WILL BE IN THE UPPER 50S ACROSS ERN LONG ISLAND AND SE
CT...LOWER 60S MOST ELSEWHERE...AND MID 60S INVOF NYC.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
MORNING LOW CLOUDS SHOULD BE SLOW TO BURN OFF ESPECIALLY ACROSS
LONG ISLAND AND COASTAL CT. SFC RIDGING AND SOUTHERLY FLOW SHOULD
KEEP THE AIR MASS STABLE OVER MOST OF THE CWA FROM NYC EAST...
WHILE ENOUGH LATE DAY INSTABILITY MAY DEVELOP WELL NORTH/WEST OF
NYC AHEAD OF AN ADVANCING WEAK SHORTWAVE TO SPARK ISOLD-SCT
SHOWERS AND POSSIBLY A TSTM. AFTERNOON COASTAL SEA BREEZES WILL BE
ENHANCED BY A TIGHT PRESSURE GRADIENT...AND COULD AGAIN SEE GUSTS
20-30 MPH LATE IN THE AFTERNOON ESPECIALLY ACROSS LONG ISLAND.
HIGH TEMPS SHOULD BE 80-85 INLAND AND IN THE 70S ALONG THE COAST.
CONVECTIVE POTENTIAL SHOULD WANE SAT EVENING WITH LOSS OF DAYTIME
HEATING...THEN COULD SEE SCT SHOWERS AND POSSIBLY A TSTM LATE AT
NIGHT AS A COLD FRONT APPROACHES. PREFER SLIGHTLY SLOWER/DRIER
FRONTAL APPROACH PER NAM/ECMWF VS FASTER/WETTER GFS...AND SO HAVE
SCALED BACK GUIDANCE POP...WITH ONLY CHANCE LATE AT NIGHT MAINLY
INLAND. LOW TEMPS SHOULD BE IN THE LOWER AND MID 60S.
THERE IS A HIGH RISK OF RIP CURRENTS AT THE ATLANTIC BEACHES
SATURDAY. STRONGEST RIP CURRENTS WOULD OCCUR DURING THE AFTERNOON
AS THE SOUTHERLY WINDS INCREASE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
COLD FRONT SLOWLY CROSSES THROUGH THE CWA THROUGH ON SUNDAY WITH
SHOWERS BECOMING LIKELY. CAPE IS SUFFICIENT FOR A CHANCE OF
THUNDERSTORMS. WITH THE COLD FRONT BECOMING ALIGNED WITH THE UPPER
FLOW ALONG WITH A RELATIVELY SLOW STORM MOTION FORECAST...WILL NEED
TO KEEP AN EYE OUT FOR THE POTENTIAL OF TRAINING CELLS AND AT LEAST
MINOR URBANIZED/SMALL STREAM FLOODING DURING THE AFTERNOON AND
EVENING HOURS.
THE COLD FRONT STALLS TO OUR SOUTH...THEN A WAVE OF LOW PRESSURE
FORMS ALONG IT...PASSING OVER OR JUST SOUTH OF US ON TUESDAY. MODELS
DISAGREE ON HOW QUICKLY THIS HAPPENS WITH ECMWF CONTINUING TO BE THE
SLOWEST WITH THE PASSAGE. HAVE GONE WITH LIKELY POPS THROUGH MONDAY
NIGHT BEFORE TAPERING TO CHC ON TUESDAY. MIGHT EVENTUALLY NEED TO
INCREASE POPS FOR TUESDAY...ESPECIALLY OVER EASTERN ZONES. ELEVATED
CAPE WILL BE JUST SOUTH OF US...SO NO MENTION OF THUNDER FROM LATE
SUNDAY NIGHT THROUGH TUESDAY.
AFTER NEAR-NORMAL HIGHS ON SUNDAY...MONDAY AND TUESDAY SHOULD BE
BELOW NORMAL WITH RAIN/CLOUDS/ONSHORE FLOW.
WILL MAINTAIN A DRY FORECAST FOR WEDNESDAY...FAVORING THE MORE
PROGRESSIVE MODELS. HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING
LOW. HIGHER CONFIDENCE THAT THURSDAY WILL BE DRY WITH THE CENTER OF
THE HIGH PASSING THROUGH. TEMPS RETURNING TO NORMAL. FRIDAY LIKELY
REMAINS DRY AS WELL WITH THE HIGH OFFSHORE AND THE NEXT COLD FRONT
WELL OFF TO THE NW.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE REMAINS OFFSHORE THROUGH SATURDAY WITH A COLD FRONT
APPROACHING FROM THE GREAT LAKES. THIS WILL KEEP THE AREA UNDER A
PROLONGED PERIOD OF SOUTHERLY FLOW.
VFR WILL LOWER TO MVFR/IFR AND BELOW IN LOW
STRATUS/FOG...ESPECIALLY KISP AND KGON. MORE UNCERTAIN FARTHER
WEST...IFR POTENTIAL LATE AT KJFK AND POTENTIAL FOR MVFR FOR OTHER
TERMINALS NORTH AND WEST.
CONDITIONS IMPROVE TO VFR AFTER 13Z SAT. THERE WILL BE A CHANCE
OF SHOWERS AND A SLIGHT CHANCE THUNDERSTORMS LATE SAT AFTN THROUGH
SAT EVE WITH MVFR POSSIBLE...BUT CONFIDENCE TOO LOW TO INCLUDE IN
TAF AT THIS TIME.
THE TIMING HAS UNCERTAINTY AND CATEGORICAL CHANGES COULD BE OFF BY
2-4 HOURS.
.OUTLOOK FOR 03Z SUNDAY THROUGH WEDNESDAY...
.SATURDAY NIGHT-TUESDAY MORNING...GUSTY S WINDS UP TO 20 KT SAT
NIGHT BUT PERHAPS AT MORE OCCASIONAL FREQUENCY. MVFR OR LOWER AT
TIMES IN SHOWERS. THUNDERSTORMS POSSIBLE SATURDAY NIGHT-SUNDAY
NIGHT.
.TUESDAY AFTERNOON/NIGHT...BECOMING VFR.
.WEDNESDAY...VFR.
&&
.MARINE...
POOR VSBYS FOR MANY AREAS TONIGHT IN FOG. DENSE FOG FOR SOME OF
THE WATERS IN EFFECT.
QUIET CONDS THROUGH EARLY SAT AFTERNOON. COASTAL SEA BREEZES
ENHANCED BY A TIGHTENING PRESSURE GRADIENT SHOULD THEN HELP
GENERATE FREQUENT GUSTS UP TO 25 KT ALONG THE NEAR SHORE WATERS
SOUTH OF LONG ISLAND LATE SAT AFTERNOON INTO SAT EVENING...SO HAVE
RAISED SCA FOR THE OCEAN AND THE SOUTH SHORE BAYS.
OCEAN SEAS MAY FLIRT WITH 5 FT LATE SAT AFTERNOON AND SAT NIGHT.
WITH SUSTAINED WINDS REMAINING MOSTLY 15 KT OR LESS HELD THEM
AT 4 FT.
SCA CONDS WILL PROBABLY BE ON THE OCEAN WATERS SUNDAY AND SUNDAY
NIGHT...HOWEVER THERE COULD BE AN EXTENDED PERIOD DURING THIS
TIME FRAME WHERE THE CRITERIA IS NOT BEING MET. E WINDS OTHERWISE
INCREASE ON MONDAY WITH SCA CONDS PROBABLE ON MOST OF THE WATERS.
WINDS THEN SUBSIDE ON TUESDAY...BUT A LINGERING SWELL MAY KEEP
OCEAN SEAS AT SCA LEVELS THROUGH THE DAY...AND PROBABLY THROUGH
MOST OF WED AS WELL.
&&
.HYDROLOGY...
FORECAST RAIN AMOUNTS FROM SUNDAY THROUGH MONDAY NIGHT CURRENTLY
RANGE FROM 1.5 TO 2.5 INCHES. AS USUAL...LOCALLY HIGHER AMOUNTS WILL
BE POSSIBLE DUE TO SCATTERED THUNDERSTORMS. THESE THUNDERSTORMS ARE
MORE LIKELY TO OCCUR SUNDAY AFTERNOON AND EVENING. THERE IS A THREAT
OF FLOODING...BUT MINOR URBAN/POOR DRAINAGE/SMALL STREAM FLOODING
WOULD BE MORE LIKELY. FLASH FLOODING IS NOT OUT OF THE QUESTION
SUNDAY AFTERNOON AND NIGHT...BUT CONFIDENCE IS NOT HIGH ENOUGH TO
INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK...ESPECIALLY WITH ANTECEDENT
DRY CONDITIONS FOR THE PAST MONTH OR SO.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR CTZ008-012.
NY...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR NYZ079-081.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ330-340-
345-350-353.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 11 PM EDT
THIS EVENING FOR ANZ345-350-353-355.
&&
$$
SYNOPSIS...JC/GOODMAN
NEAR TERM...GOODMAN/DS/PW
SHORT TERM...GOODMAN
LONG TERM...JC
AVIATION...JM
MARINE...JC/GOODMAN/PW
HYDROLOGY...JC
AREA FORECAST DISCUSSION
NWS GOODLAND KS
231 AM MDT SAT MAY 30 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1240 PM MDT FRI MAY 29 2015
RAP ANALYSIS INDICATED A SHORTWAVE TROUGH POSITIONED ACROSS THE
NORTH CENTRAL HIGH PLAINS REGION...WHICH WAS MOVING INTO THE CENTRAL
HIGH PLAINS. AN ASSOCIATED COLD FRONT WITH THIS UPPER LEVEL SYSTEM
WAS DRAPED ACROSS THE NORTH CENTRAL PLAINS. VISIBLE SATELLITE
IMAGERY INDICATED A POPULATED CUMULUS FIELD STARTING AT HIGHWAY 83
AND INCREASED IN DENSITY TO THE WEST. RADAR INDICATED SHOWERS
BEGINNING TO FORM OVER YUMA COUNTY.
HIRES NMM...ARW...AND RAP ANALYSIS HAVE STORMS DEVELOPING CLOSER TO
21Z...AND BECOMING MORE WIDESPREAD TOWARDS 00Z TONIGHT. LAPSE RATES
ALOFT TRANSLATE TO BETWEEN 400 AND 600 J/KG IN THE PROFILE...WITH
CAPE VALUES DECREASING AFTER SUNSET. WITH 0-6 SHEAR VALUES ON THE
FRINGE OF 40 KTS...SOME SEVERE STORMS CANNOT BE RULED OUT ACROSS THE
AREA...ALTHOUGH A MAJORITY OF STORMS SHOULD REMAIN SUB SEVERE.
SHOWERS AND ISOLATED THUNDERSTORMS WILL TAPER OFF INTO THE LATE
EVENING HOURS TONIGHT WITH INCREASING CLOUDINESS. KEPT LOW
TEMPERATURES SLIGHTLY WARMER THAN MOS OUTPUT DUE TO BLANKETING
OVERCAST CLOUD COVER. AN UPPER LEVEL RIDGE WILL BUILD INTO THE
REGION FROM THE WEST...WHICH WILL KEEP CONDITIONS DRY SATURDAY WITH
DECREASING CLOUDS AFTER MID MORNING. HIGH TEMPERATURES WILL BE
SLIGHTLY COOLER DUE TO COLD AIR ADVECTION AT THE SURFACE IN THE
UPPER 60S TO LOWER 70S...WHICH IS ABOUT 10 DEGREES BELOW NORMAL
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 228 AM MDT SAT MAY 30 2015
AT THE BEGINNING OF THE EXTENDED PERIOD MODELS SHOW A MID/UPPER
LEVEL TROUGH DEVELOPING OVER THE WESTERN UNITED STATES AND
GRADUALLY DEEPENING/AMPLIFYING TOWARDS THE END OF THE PERIOD. THE
POSITION OF THIS TROUGH WILL PRODUCE A PREDOMINANT SOUTHWEST FLOW
OVER THE TRI STATE AREA FOR THE WEEK. NUMEROUS SHORTWAVE TROUGHS
ARE EXPECTED TO MOVE ALONG THIS FLOW AND CROSS OUR REGION. AT THE
SAME TIME... ON THE SURFACE... ANTICIPATE LOW LEVEL MOISTURE BEING
BROUGHT IN BY SOUTH TO SOUTHEAST WINDS.
THIS PATTERN WILL HELP MAINTAIN HIGH TEMPERATURES IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID 50S TO LOW 60S FOR THE REST OF THE
WEEK AND INTO THE WEEKEND. IT WILL ALSO PRODUCE A CHANCE OF
PRECIPITATION IN THE FORM OF SHOWERS AND THUNDERSTORMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1107 PM MDT FRI MAY 29 2015
MVFR CONDITIONS DUE TO STRATUS WILL PERSIST OVERNIGHT AT KMCK AND
KGLD. CONDITIONS SHOULD IMPROVE AT BOTH SITES BY MID MORNING
SATURDAY WITH VFR EXPECTED FOR THE REST OF THIS TAF PERIOD AS HIGH
PRESSURE AND SUBSIDENCE MOVE INTO THE REGION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...BW
AVIATION...FS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1237 AM CDT SAT MAY 30 2015
...UPDATED AVIATION SECTION...
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 1200 PM CDT FRI MAY 29 2015
TONIGHT:
MUCH MORE TRANQUIL SENSIBLE WEATHER IS EXPECTED FOR THIS EVENING COMPARED
TO THE LAST TWO EVENINGS. THERE WILL STILL BE A CHANCE FOR THUNDERSTORMS,
BUT THIS ACTIVITY SHOULD BE MUCH MORE LIMITED IN TERMS OF COVERAGE AND
INTENSITY. FOLLOWED A BLEND OF HRRR AND ARW GUIDANCE, WHICH SHOWS CONVECTION
MOVING ACROSS OUR NORTHERN ZONES. THERE MIGHT BE ANOTHER SHOT AT CONVECTION
TOWARDS 06Z ACROSS SOUTH-CENTRAL KANSAS AS DESCRIBED BY THE NAM. CONFIDENCE
IS LOWER IN THIS SOLUTION AS DRY AIR ADVECTS IN AND INSTABILITY BECOMES
MEDIOCRE TO NON-EXISTENT. SEVERE WEATHER IS NOT EXPECTED AS SHEAR AND
CAPE IS MARGINAL. THERE COULD BE SOME MARGINAL STORMS, BUT THAT IS ABOUT
IT. LOWS WILL BE A LITTLE BIT COOLER (UPPER 40S TO LOWER 50S) AS DRIER
AIR/LOW DEWPOINTS ADVECT IN AS ALREADY MENTIONED ABOVE.
TOMORROW:
A PRECIPITATION-FREE FORECAST IS EXPECTED TOMORROW WITH POPS AT ZERO
PERCENT. HIGHS WILL BE COOLER UNDER THE 11-16C 850-HPA AIR MASS. EXPECTING
VALUES IN THE 68-71F RANGE. WINDS WILL SLOWLY VEER AROUND TO THE EAST
BY DUSK.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 PM CDT FRI MAY 29 2015
SOUTHWEST KANSAS WILL BE IN A QUIETER PERIOD WEATHER-WISE DURING
THE FIRST FIRST FEW DAYS OF THE EXTENDED PERIOD. BY SATURDAY
NIGHT, THE UPPER LEVEL TROUGH CURRENTLY OVER THE NORTHERN AND
CENTRAL PLAINS WILL HAVE MOVED EAST INTO THE GREAT LAKES AND
MISSISSIPPI VALLEY. FARTHER WEST, UPPER LEVEL RIDGING WILL BE
BUILDING EAST ACROSS THE NORTHERN AND CENTRAL ROCKIES INTO THE
ADJACENT HIGH PLAINS. SURFACE HIGH PRESSURE WILL BE EXTENDING FROM
THE MIDWEST INTO THE CENTRAL AND SOUTHERN PLAINS. THE COOL HIGH
PRESSURE WILL RESULT IN OVERNIGHT LOWS SUNDAY MORNING IN THE MID
40S TO LOW 50S. INCREASING WESTERLY FLOW ACROSS THE NORTHERN INTO
THE CENTRAL PLAINS WILL INDUCE LEE SIDE TROUGHING ALONG THE
EASTERN SLOPES OF THE NORTHERN AND CENTRAL ROCKIES. EAST OF THE
TROUGH, A STRENGTHENING PRESSURE GRADIENT WILL BRING INCREASING
SOUTHERLY WINDS TO WESTERN KANSAS ALONG WITH SOME MODEST LOW LEVEL
MOISTURE RETURN.
BY LATE SUNDAY THROUGH LATE MONDAY, A FEW OF THE MEDIUM RANGE MODELS
HINT AT SOME THUNDERSTORM POTENTIAL SOMEWHERE ACROSS THE HIGH
PLAINS GIVEN THE MOISTURE RETURN AND INCREASE IN LOW LEVEL WARM
MOIST ADVECTION. THIS TYPE OF PATTERN HOLDS TROUGH MID WEEK. LOW
LEVEL MOISTURE WILL BE INCREASING WITH TIME. THERE WILL BE
INCREASING CHANCES FOR EVENING AND NIGHTTIME MCS DEVELOPMENT
ACROSS THE CENTRAL HIGH PLAINS AS THE LOW LEVEL JET HELPS FOCUS
THUNDERSTORM DEVELOPMENT. BETTER CHANCES FOR MCS DEVELOPMENT MAY
BE FOCUSED MORE OVER NEBRASKA AND POSSIBLY NORTHERN KANSAS WHERE
THE NOSE OF THE LOW LEVEL JET WILL BE LOCATED. THE ATMOSPHERE MAY
REMAIN BETTER CAPPED FARTHER SOUTH ACROSS WESTERN KANSAS, KEEPING
THUNDERSTORMS MORE ISOLATED.
TOWARD NEXT WEEKEND, THE MODELS SHOW AN UPPER LEVEL TROUGH
REDEVELOPING OVER THE WESTERN CONUS WITH UPPER FLOW TURNING MORE
SOUTHWESTERLY OVER THE CENTRAL HIGH PLAINS. THE ECMWF IS MORE
AMPLIFIED WITH THIS PATTERN THAN THE GFS BUT EITHER WAY, THIS
PATTERN COULD BRING INCREASING CHANCES FOR THUNDERSTORMS AND
HEAVY RAIN ACROSS WESTERN KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1234 AM CDT SAT MAY 30 2015
A COLD FRONT THAT EXTENDED FROM NORTHEAST KANSAS INTO NORTHWEST
OKLAHOMA AT MIDNIGHT WILL CONTINUE MOVING SOUTH AND WILL EXTEND
FROM SOUTHEAST MISSOURI INTO CENTRAL TEXAS BY EARLY SATURDAY
AFTERNOON. SURFACE HIGH PRESSURE WILL BUILD INTO WESTERN KANSAS
BEHIND THE FRONT TODAY. AN EXTENSIVE STRATUS DECK WITH CEILINGS
015-020 IN THE REGION OF COLD AIR ADVECTION BEHIND THE FRONT WILL
CONTINUE TO SPREAD SOUTH ACROSS WESTERN KANSAS EARLY THIS MORNING
BUT WILL BEGIN TO ERODE AFTER SUNRISE. VFR CONDITIONS SHOULD
PREVAIL BY 16Z AT ALL TAF LOCATIONS AND WILL CONTINUE THROUGH
SUNDAY. LOW LEVEL NORTH WINDS 15 TO 20 KTS WITH GUSTS TO NEAR 30
MPH WILL DECREASE TO 10-15 KTS BY MID MORNING AND WILL BECOME EAST
AT LESS THAN 10 KTS BEFORE SUNSET.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 77 57 83 / 0 0 10 10
GCK 49 79 58 84 / 0 0 10 10
EHA 52 83 59 87 / 0 0 10 10
LBL 50 80 59 85 / 0 0 10 10
HYS 46 77 55 82 / 0 0 10 10
P28 49 77 56 81 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...RUTHI
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1114 PM MDT FRI MAY 29 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1240 PM MDT FRI MAY 29 2015
RAP ANALYSIS INDICATED A SHORTWAVE TROUGH POSITIONED ACROSS THE
NORTH CENTRAL HIGH PLAINS REGION...WHICH WAS MOVING INTO THE CENTRAL
HIGH PLAINS. AN ASSOCIATED COLD FRONT WITH THIS UPPER LEVEL SYSTEM
WAS DRAPED ACROSS THE NORTH CENTRAL PLAINS. VISIBLE SATELLITE
IMAGERY INDICATED A POPULATED CUMULUS FIELD STARTING AT HIGHWAY 83
AND INCREASED IN DENSITY TO THE WEST. RADAR INDICATED SHOWERS
BEGINNING TO FORM OVER YUMA COUNTY.
HIRES NMM...ARW...AND RAP ANALYSIS HAVE STORMS DEVELOPING CLOSER TO
21Z...AND BECOMING MORE WIDESPREAD TOWARDS 00Z TONIGHT. LAPSE RATES
ALOFT TRANSLATE TO BETWEEN 400 AND 600 J/KG IN THE PROFILE...WITH
CAPE VALUES DECREASING AFTER SUNSET. WITH 0-6 SHEAR VALUES ON THE
FRINGE OF 40 KTS...SOME SEVERE STORMS CANNOT BE RULED OUT ACROSS THE
AREA...ALTHOUGH A MAJORITY OF STORMS SHOULD REMAIN SUB SEVERE.
SHOWERS AND ISOLATED THUNDERSTORMS WILL TAPER OFF INTO THE LATE
EVENING HOURS TONIGHT WITH INCREASING CLOUDINESS. KEPT LOW
TEMPERATURES SLIGHTLY WARMER THAN MOS OUTPUT DUE TO BLANKETING
OVERCAST CLOUD COVER. AN UPPER LEVEL RIDGE WILL BUILD INTO THE
REGION FROM THE WEST...WHICH WILL KEEP CONDITIONS DRY SATURDAY WITH
DECREASING CLOUDS AFTER MID MORNING. HIGH TEMPERATURES WILL BE
SLIGHTLY COOLER DUE TO COLD AIR ADVECTION AT THE SURFACE IN THE
UPPER 60S TO LOWER 70S...WHICH IS ABOUT 10 DEGREES BELOW NORMAL
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 232 PM MDT FRI MAY 29 2015
FORECAST PROBLEMS AT THE BEGINNING OF THE PERIOD ARE CHANCES OF
PRECIPITATION AND HOW MUCH IT WARMS UP SUNDAY AND MONDAY. SATELLITE
SHOWING AN AMPLIFIED AND COMPLICATED FLOW FROM THE CENTRAL PACIFIC
INTO EASTERN NORTH AMERICA.
MODELS INITIALIZED REASONABLE WELL ON THE JET AND MID LEVELS WITH
SO SERIOUS PROBLEMS. MODELS DO NOT START OUT STRONG ENOUGH WITH
THE SURFACE RIDGING BEHIND THE CURRENT FRONT. THE NAM WAS DOING
THE BEST. MODELS TENDED TO START OUT TOO WARM. OVERALL THE
GFS...ECMWF AND CANADIAN WERE DOING A LITTLE BETTER.
SATURDAY NIGHT...SURFACE RIDGE STARTS OUT OVER THE AREA EARLY IN THE
NIGHT. AT THE SAME WEAK SHORTWAVE RIDGING AND RISING HEIGHTS WILL
OCCUR THROUGH THE FIRST HALF OF THE NIGHT. A WEAK SHORTWAVE TROUGH
DOES MOVE THROUGH LATE IN THE NIGHT. MODELS DO HAVE SOME ELEVATED
CAPE BUT INHIBITION LOOKS STRONG ENOUGH TO KEEP ANY STORMS FROM
DEVELOPING. ALSO VERY DEEP DRY LAYER WITH ONLY THE VERY LOW LEVELS
HAVING ANY MOISTURE. SO WILL KEEP THIS PERIOD DRY.
RETURN FLOW BECOMES THE STRONGEST OVER THE FAR WESTERN PORTION.
MODELS HINTING AT...MAINLY THE NAM...ABOUT SOME STRATUS DEVELOPING.
THIS MAY BE A BIT FAST. CONSIDERING THIS AND THE SHORTWAVE TROUGH
SPREADING IN CLOUDS...WILL INCREASE CLOUDS LATE IN THE NIGHT. THE
FAR EAST WILL HAVE THE COOLEST TEMPERATURES DUE TO THE BEST COOLING
CONDITIONS THERE.
SUNDAY/SUNDAY NIGHT...A WEAK SHORTWAVE TROUGH WILL PUSH A SURFACE
TROUGH INTO THE FAR WESTERN PORTION OF THE AREA LATE IN THE DAY.
THAT BOUNDARY LOOKS TO RETREAT TO THE WEST DURING THE EVENING WITH
ANOTHER SURFACE TROUGH MOVING INTO THE WEST HALF OF THE AREA DURING
THE OVERNIGHT HOURS...PROBABLY DUE TO ANOTHER WEAK SHORTWAVE TROUGH
MOVING THROUGH. RIDGE ALOFT STARTS BUILDING IN WITH SOME MINOR
HEIGHT RISES.
THERE LOOKS TO BE SOME WEAK CONVERGENCE WITH DEWPOINTS TO THE
EAST OF IT IN THE 50S...ALTHOUGH THE MODELS DO DISAGREE WITH HOW
MUCH. MODEL SOUNDINGS SHOW LITTLE TO NO MOISTURE ALOFT. DURING THE
NIGHT MODELS DO HAVE SOME ELEVATED INSTABILITY MOVING ACROSS WITH
A DECENT AMOUNT OF CINH...WITH THE WEAKEST CAP LATER IN THE
NIGHT...MAINLY IN THE NORTHEAST. DURING THE DAY WILL KEEP THE IT
DRY NEAR THE SURFACE TROUGH BUT WILL HAVE HIGH SILENT POPS. WILL
KEEP HIGH SILENT/DRY POPS DURING THE NIGHT. LOOKING LIKE IT WILL
BE DRY BUT WOULD NOT BE SURPRISED TO SEE AN ISOLATED
THUNDERSTORM.
PRESSURE GRADIENT AND FALLS WOULD SUPPORT BREEZY OR NEAR BREEZY
CONDITIONS TO THE EAST OF THE COLORADO BORDER. WIND DIRECTION DOES
NOT BECOME DOWNSLOPE EXCEPT MAYBE FOR THE FAR WEST. NEWER GUIDANCE
SUPPORTS A LITTLE WARMER FORECAST THAN PREVIOUS PACKAGE AND WILL USE
THE BETTER PERFORMING GUIDANCE IN MAKING THOSE ADJUSTMENTS. FOR THE
NIGHT...DOES LOOK LIKE A BETTER CHANCE FOR STRATUS AND MAYBE SOME
FOG. LOW TEMPERATURES WILL BE WARMER DUE TO PERSISTENT SOUTHERLY
WINDS...HIGHER DEWPOINTS AND STRATUS.
MONDAY...LEE TROUGH PULLS BACK TO THE WEST OF THE AREA DURING THE
DAY WITH SOUTH TO SOUTHEAST WINDS OVER THE ENTIRE AREA. RIDGE
CONTINUES TO BUILD IN AND IS RATHER STRONG...ESPECIALLY AT 500 MB.
THE RIDGE MOVES SLIGHTLY EAST DURING THE DAY WHICH MAY ALLOW A WEAK
SHORTWAVE TROUGH TO APPROACH THE WESTERN PORTION OF THE AREA IN THE
AFTERNOON.
MODELS SHOW LITTLE TO NO CAP WITH AN ADEQUATE AMOUNT OF LOW LEVEL
MOISTURE. ALOFT THE TEMPERATURES ARE GETTING RATHER WARM BUT
BREAKABLE. SHORTWAVE TROUGH IS NEAR THE WESTERN END OF THE AREA WITH
THE SURFACE TROUGH TO THE WEST. STORM MOTIONS ARE RATHER SLOW. AT
THIS TIME WILL INTRODUCE A SLIGHT CHANCE TO THE FAR WEST.
NO DOWNSLOPE COMPONENT TO THE WINDS WHICH WILL HINDER THE WARMUP A
LITTLE. ALL THINGS CONSIDERED...TEMPERATURES WILL BE WARMER THAN THE
PREVIOUS DAY AND GUIDANCE HAS GOTTEN WARMER. CONSIDERING THAT PLUS
RECENT RAINS...WILL NOT GO AS WARM AS THE WARMEST GUIDANCE.
MONDAY NIGHT THROUGH FRIDAY...DURING THIS PERIOD MID/UPPER LEVEL
TROUGH DEVELOPS OVER THE WESTERN PORTION OF THE COUNTRY AND
GRADUALLY DEEPENS/AMPLIFIES AT THE END OF THE PERIOD. MODELS SHOWING
NUMEROUS SHORTWAVES MOVING THROUGH THE FLOW ACROSS OUR REGION. AT
THE SURFACE...MODELS ARE ALSO SIMILAR WITH A PERSISTENT LEE
TROUGH/DRYLINE/SOME BOUNDARY NEAR OR OVER THE WESTERN PORTION OF OUR
AREA WITH SOUTH TO SOUTHEAST WINDS BRINGING IN LOW LEVEL MOISTURE.
THIS MATCHED WELL WITH WHAT THE CRH_INIT GAVE ME AND DID NOT CHANGE.
OVERALL DID NOT CHANGE ANYTHING WITH INIT PRODUCING REASONABLE
OUTPUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1107 PM MDT FRI MAY 29 2015
MVFR CONDITIONS DUE TO STRATUS WILL PERSIST OVERNIGHT AT KMCK AND
KGLD. CONDITIONS SHOULD IMPROVE AT BOTH SITES BY MID MORNING
SATURDAY WITH VFR EXPECTED FOR THE REST OF THIS TAF PERIOD AS HIGH
PRESSURE AND SUBSIDENCE MOVE INTO THE REGION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
325 AM CDT SAT MAY 30 2015
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 324 AM CDT SAT MAY 30 2015
A WELL-DEVELOPED MCV OVER CENTRAL ARKANSAS AND ASSOCIATED SURFACE
LOW OVER NORTH CENTRAL ARKANSAS AS OF 08Z ARE FORECAST BY ALL
AVAILABLE GUIDANCE TO LIFT NORTHEAST ACROSS OUR AREA TODAY. THEY
SHOULD REACH SOUTHEAST MISSOURI BY MIDDAY AND THEN MOVE ACROSS THE
REMAINDER OF THE REGION THROUGH SUNSET. LATEST RADAR TRENDS
INDICATE THAT SCATTERED SHOWERS WILL LIFT NORTH OF OUR SOUTHEAST
MISSOURI COUNTIES BY 09Z AND MOST...IF NOT ALL...OF THE AREA
SHOULD BE DRY AT SUNRISE.
THE LATEST HRRR AND THE 00Z NMM AND ARW WRF RUNS DEVELOP SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE AREA BY
MIDDAY...AND MAINTAIN GOOD COVERAGE OF CONVECTION THROUGH THE
AFTERNOON...BEFORE COMING TO AN END FROM SOUTHWEST TO NORTHEAST
THIS EVENING.
LIKELY TO CATEGORICAL POPS SEEM LIKE THE WAY TO GO. NOT SURE HOW
MUCH HEATING WE WILL BE ABLE TO MUSTER WITH LOTS OF CLOUDS
EXPECTED THROUGH THE DAY...BUT CANNOT RULE OUT A STRAY STRONG
STORM WITH DAMAGING WINDS. ORGANIZED SEVERE WEATHER SEEMS
UNLIKELY TODAY. LOCALLY HEAVY RAINFALL AND LIGHTNING WILL BE THE
PRIMARY CONCERNS.
SOUTH WINDS WILL PICK UP ACROSS THE AREA THIS MORNING...AND MAY
PUSH LAKE WIND ADVISORY CRITERIA OVER MUCH OF THE REGION.
HOWEVER...WILL NOT BE ISSUING AN ADVISORY AT THIS TIME...MAINLY
DUE TO THE EXPECTED COVERAGE OF CONVECTION.
IN THE WAKE OF THE SURFACE LOW...SURFACE HIGH PRESSURE WILL BEGIN
TO BUILD ACROSS THE AREA LATE TONIGHT AND SUNDAY. REALLY NOT
SEEING MUCH IN THE WAY OF QPF FROM THE 00Z MODELS ON SUNDAY...BUT
WITH THE LARGER-SCALE MID/UPPER-LEVEL TROUGH MOVING THROUGH THE
REGION...CANNOT RULE OUT AN ISOLATED SHOWER OR STORM OVER THE
SOUTHEAST HALF OF THE REGION.
THE FORECAST IS DRY FROM SUNDAY NIGHT THROUGH MONDAY NIGHT AS
COOL...DRY SURFACE HIGH PRESSURE DOMINATES THE REGION.
TEMPERATURES TODAY THROUGH SUNDAY WILL BE HIGHLY DEPENDENT ON
CLOUDS AND CONVECTION. THE CONSENSUS OF GUIDANCE IS TRENDING
COOLER...AND WAS FOLLOWED PRETTY CLOSELY THROUGH THE ENTIRE SHORT
TERM PERIOD
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 324 AM CDT SAT MAY 30 2015
WHAT A DIFFERENCE 24 HRS MAKES. THOUGH THERE WERE HINTS PREVIOUSLY
THAT IT MIGHT HAPPEN...THE MED RANGE MODELS HAVE NOW TRENDED MUCH
DRIER IN THE EXTENDED PERIOD...ESPECIALLY IN THE FIRST HALF. THE
PREVIOUSLY SUGGESTED RIDGING ALOFT OVER THE PAH FORECAST AREA
APPEARS TO HAVE MORE DOMINANCE NOW AS A DOME OF SFC HIGH PRESSURE
SLOWLY FILTERS INTO THE AREA INITIALLY. AS A WRN CONUS TROF PERSISTS
IN VARYING DEGREES ACCORDING TO DIFFERENT MODEL SOLUTIONS...SOME
VERSION OF MID LEVEL RIDGING SHOULD PREVAIL OVER OUR REGION
THROUGHOUT THE EXTENDED PERIOD...WITH THE NRN STREAM REMAINING
ACTIVE. LATER IN THE PERIOD...A WEAKNESS IN THE ERN CONUS RIDGE
APPEARED TO BE FAR AWAY ENOUGH FROM THE PAH FORECAST AREA (THE
ATLANTIC COAST) AS TO NOT HAVE A DIRECT INFLUENCE ON OUR WEATHER.
THE FLOW ALOFT OVER US WILL BE WEAK.
BY THU...LOW LEVEL WINDS SHOULD PICK UP MORE OF A SRLY COMPONENT
OVER OUR REGION...AND THEREFORE DEEPER MOISTURE SHOULD BE MADE
AVAILABLE. THIS COMBINED WITH INCREASED INSTABILITY MAY YIELD THE
DEVELOPMENT OF ISOLD TSTMS IN THE SOUTH BY AFTERNOON. THE DIURNALLY-
DRIVEN CONVECTION SHOULD DISAPPEAR THU NIGHT..THEN RETURN FOR FRI
WITH SOMEWHAT BETTER COVERAGE.
IN THE SOMEWHAT DRIER AIR MID WEEK...AFTERNOON TEMPS ARE EXPECTED TO
STILL REACH ABOUT 80 TUE...CLIMBING INTO THE LOWER TO MIDDLE 80S
WITH HIGHER HUMIDITY FOR THE REST OF THE PERIOD...DEPENDING ON CLOUD
COVER. LOWS ARE EXPECTED TO RISE FROM ABOUT 60 INITIALLY TO ABOUT
65.
&&
.AVIATION...
ISSUED AT 1152 PM CDT FRI MAY 29 2015
VFR CEILINGS WILL DOMINATE MOST OF THE MORNING...WITH MVFR/LOCAL
IFR CONDITIONS WITH THE DEVELOPMENT OF CONVECTION LATER SATURDAY
AND SATURDAY NIGHT. AS THE SURFACE LOW AND ATTENDANT WEAK COLD
FRONT DEVELOP NORTHWEST OF THE WFO PAH TAF SITES, CEILINGS WILL
WORK DOWNWARD WITH TIME AS THE LOW MOVES EAST OF THE AREA.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...DB
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1153 PM CDT FRI MAY 29 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 132 PM CDT FRI MAY 29 2015
THE HRRR PICKS UP ON CONVECTION TO OUR WEST IF OVERDONE A TAD. IT
BASICALLY MIGRATES SCATTERED CONVECTIVE ELEMENTS INTO OUR SEMO
OZARK COUNTIES TONIGHT. IT DOS NOT MODEL ACCURATELY THE WIDELY
SCATTERED ACTIVITY IN OUR EAST...BUT DOES SUGGEST SIMILAR TREND
THERE INTO THE EARLY EVENING HOURS.
OVER TIME...SYNOPTIC MODELING IS THE SAME...DRAWING FRONT IN AND
THIS WEEKEND WITH PASSAGE AND HIGH POP EVENT. LACKING STRONG
FORCING...IT APPEARS TO BE MAINLY A HEAVY RAIN THREAT...WITH
PERHAPS PULSE MAINLY HEAT OF DAY STORMS BEARING WATCH ON THEIR
INTENSITY. POPS PEAK ALONG/AHEAD OF PASSING BOUNDARY SATURDAY INTO
SATURDAY NIGHT.
ON THE BACK SIDE OF THE FRONT BEGINNING SUNDAY INTO SUNDAY
NIGHT...POPS MAY LINGER BUT DRIER AIR STARTS TO WORK DOWN THE
COLUMN. WE`LL SEE SOME DEW POINTS DROPPING BACK INTO THE 50S THEN
AND EFFECTIVELY THIS WILL WORK TOWARD ENDING POPS FROM NORTHWEST
TO SOUTHEAST WITH TIME.
SUMMER LIKE WARMTH/HUMIDITY 80S/60S CONTINUES UNTIL FROPA...AFTER
WHICH THE MOVE BACK INTO THE 70S/50S COMMENCES SUNDAY-SUNDAY
NIGHT.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 153 PM CDT FRI MAY 29 2015
A WEAK UPPER-LEVEL FLOW PATTERN WILL CONTINUE THROUGH THE LONG
TERM...WHICH SHOULD BECOME MORE FREQUENT AS WE HEAD INTO THE SUMMER
MONTHS. EARLY IN THE WEEK...WEAK TROUGHING OVER THE LOWER OHIO
VALLEY WILL BRING SOMEWHAT COOLER AND DRIER CONDITIONS. BROAD
RIDGING WILL FOLLOW IN THE WAKE OF THE TROUGH FOR MID TO LATE WEEK.
THIS WILL RESULT IN A GRADUAL INCREASE IN WARMTH AND HUMIDITY.
AS FAR AS THE SPECIFICS...MONDAY THROUGH TUESDAY NOW LOOK MAINLY DRY
AND A LITTLE COOLER. THE MODELS HAVE TRENDED DRIER AND A BIT COOLER.
POPS WILL BE REMOVED FOR MUCH OF THE AREA...BUT A SLIGHT CHANCE OF
SHOWERS WILL BE KEPT FOR PARTS OF WESTERN KENTUCKY. WITH THE COOLER
AND DRIER AIR...INSTABILITY LOOKS TOO LIMITED FOR THUNDER. LINGERING
CLOUDS SHOULD KEEP HIGHS IN THE 70S ON MONDAY. EVEN WITH LOTS OF SUN
ON TUESDAY...HIGHS SHOULD GENERALLY BE AROUND 80 DEGREES. AS FOR
OVERNIGHT LOWS...HIGH PRESSURE OVER THE GREAT LAKES WILL BRING DRIER
AIR AND LIGHT WINDS...WHICH SHOULD ALLOW MOST PLACES TO FALL INTO
THE 50S.
WEDNESDAY THROUGH FRIDAY...LOW LEVEL WINDS WILL VEER FROM THE EAST
INTO THE SOUTH AS THE HIGHS RETREATS TO THE EAST COAST. LOW LEVEL
MOISTURE WILL SLOWLY CREEP UP. WITH THE INCREASING MOISTURE WILL
COME A SMALL CHANCE OF DIURNALLY INDUCED SHOWERS AND
STORMS...ESPECIALLY THURSDAY AND FRIDAY. HIGHS WILL INCH BACK INTO
THE LOWER AND MID 80S...AND OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.AVIATION...
ISSUED AT 1152 PM CDT FRI MAY 29 2015
VFR CEILINGS WILL DOMINATE MOST OF THE MORNING...WITH MVFR/LOCAL
IFR CONDITIONS WITH THE DEVELOPMENT OF CONVECTION LATER SATURDAY
AND SATURDAY NIGHT. AS THE SURFACE LOW AND ATTENDANT WEAK COLD
FRONT DEVELOP NORTHWEST OF THE WFO PAH TAF SITES, CEILINGS WILL
WORK DOWNWARD WITH TIME AS THE LOW MOVES EAST OF THE AREA.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1246 AM EDT SAT MAY 30 2015
.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH THE REGION FROM THE WEST ON
SATURDAY AND CROSS THE AREA SATURDAY NIGHT INTO SUNDAY MORNING.
COOLER AND DRIER WEATHER WILL WORK INTO THE REGION LATER SUNDAY
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE: WE BEEFED UP CLD CVR OVR DOWNEAST...E CNTRL AND NE
PTNS OF THE FA FOR THE REMAINDER OF THE LATE NGT INTO ERLY MORN
HRS SAT WI THE THE ADVC OF MARINE ST. OTHERWISE...FCST HRLY TEMPS
WERE UPDATED FOR THE REMAINDER OF THE LATE NGT BASED ON MDNGT
OBSVD TEMPS TO UNCHGD FCST LOWS AT 5 AM.
PREV DISC: CONCERNS WILL BE LOW CLOUDS AND FOG TONIGHT AND
CONVECTIVE POTENTIAL FOR SATURDAY.
FOR TONIGHT...STARTING OUT CLEAR AND COOL, BUT A SOUTHERLY FLOW
SETTING UP LATER ON WILL BEGIN TO BRING A HUMID AIRMASS INTO THE
REGION. ALONG W/THIS HUMID AIRMASS WILL BE LOW CLOUDS AND FOG.
SOME OF THE SHORT RANGE GUIDANCE(NAM AND THE HRRR 3KM) HINTED AT
SOME LIGHT PRECIP IN THE FORM OF RAIN SHOWERS OR DRIZZLE PUSHING
IN FROM THE GULF OF MAINE WATERS LATER TONIGHT. SINCE THE
SOUTHERLY FLOW APPEARS TO TO BE RESTRICTED BELOW 925MBS AND VERY
DRY ABOVE THE THAT LAYER, THINKING HERE IS THAT SHOWERS/DRIZZLE
WILL BE LIMITED/SPOTTY AT BEST. ATTM, DECIDED TO HIT THE FOG
HARDER FOR THE INTERIOR DOWNEAST REGION AND THE COAST OVERNIGHT
INTO EARLY SATURDAY MORNING. NORTHERN AND CENTRAL AREAS WILL SEE
PATCHY FOG W/THAT LOW CLOUD DECK PUSHING NORTHWARD.
FOR SATURDAY...A COLD FRONT IS FORECAST TO APPROACH THE REGION
FROM QUEBEC. LOW CLOUDS AND FOG WILL BEGIN TO LIFT AND BURN OFF BY
MID TO LATE MORNING. SOME HEATING WILL TAKE PLACE ESPECIALLY
ACROSS THE WESTERN PORTION OF THE CWA W/THIS AREA DESTABILIZING
QUICKLY BY THE AFTERNOON. FURTHER EAST, CLOUDS COULD HANG ON FOR
A WHILE KEEPING LLVLS STABLE FOR A TIME, BEFORE THINGS BREAKOUT
AND DESTABILIZATION TAKES PLACE. DEWPOINTS ARE FORECAST TO SHOOT
THROUGH THE 50S AND GO WELL INTO MID 60S BY LATE IN THE DAY. THE
NAM12 AND GFS SOUNDINGS SHOW SB CAPES HITTING 700-1200 JOULES BY
LATE SATURDAY AFTERNOON AND LI`S DROPPING TO -2 OR SO AND 0-6KM
SHEAR OF 40 KTS. FLOW TURNS TO THE SW THROUGH THE COLUMN W/SOME
DIRECTIONAL SHEAR NOTED IN THE LLVLS ESPECIALLY ACROSS THE FAR N
AND W. THERE IS ALSO A GOOD MID LEVEL JET OF 50 KTS FORECAST TO
BE HITTING THE REGION LATER IN THE DAY WHICH WOULD ENHANCE THE
FORCING. FREEZING LEVELS ARE FORECAST TO BE AROUND 12K FT. SO HAIL
IS A POSSIBILITY. THE LIMITING FACTOR IS THAT LAPSE RATES ARE NOT
OVERLY IMPRESSIVE ACROSS THE CWA, ESPECIALLY IN THE MID LEVELS.
THE BEST LAPSE RATES RUN THROUGH QUEBEC AHEAD OF THE APPROACHING
FRONT. AFTER COLLABORATING W/GYX, DECIDED TO ADD ENHANCED WORDING
FOR TSTMS MAINLY WIND GUSTS AND HAIL. SPC HAS THE WESTERN AND
NORTHERN AREAS IN A MARGINAL RISK FOR SOME ISOLATED SEVERE STORMS.
DAYTIME HIGH TEMPS ARE FORECAST TO BE IN THE 80S ACROSS THE NORTH
AND WEST WHILE THE DOWNEAST AND COAST WILL BE COOLER W/A SSW FLOW.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
SHOWERS AND A FEW THUNDERSTORMS WILL BE ONGOING ACROSS THE REGION
EARLY SATURDAY EVENING AS THE COLD FRONT PUSHES ACROSS THE AREA.
WILL MENTION POSSIBILITY OF GUSTY WINDS AND SMALL HAIL ACROSS
WESTERN AREAS EARLY SATURDAY EVENING. THE COLD FRONT SHOULD BE TO
THE DOWN EAST COAST OF MAINE BY DAYBREAK SUNDAY. EXPECT A
CONTINUED CHANCE FOR SHOWERS SATURDAY NIGHT ESPECIALLY ACROSS
CENTRAL AND DOWN EAST AREAS. HIGH PRESSURE WILL START TO BUILD IN
FROM THE NORTHWEST DURING SUNDAY. EXPECT THE BEST WEATHER TO BE
FOUND ACROSS NORTHERN MOST MAINE CLOSER TO THE CENTER OF THE HIGH.
HOWEVER, CLOUDS AND A FEW SHOWERS CAN BE EXPECTED TO LINGER ACROSS
DOWN EAST MAINE. EXPECT MAINLY CLEAR SKIES ACROSS THE NORTH SUNDAY
AND PARTLY CLOUDY SKIES ACROSS CENTRAL AND DOWN EAST AREAS. LOW
TEMPERATURES SUNDAY NIGHT WILL FALL INTO THE MID 30S TO AROUND 40
ACROSS NORTHERN AREAS. THERE IS EVEN THE POSSIBILITY FOR SOME
PATCHY FROST ACROSS THE COLDER VALLEY LOCATIONS OF NORTHERN AND
NORTHWEST MAINE BUT WONT MENTION QUITE YET. MONDAY IS SHAPING UP
AS A MAINLY DRY DAY ACROSS MOST OF THE AREA AS HIGH PRESSURE
BUILDS IN FROM THE NORTH.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH MONDAY NIGHT AND THEN
MOVE INTO THE CANADIAN MARITIMES BY TUESDAY. LOW PRESSURE MOVING
UP FROM THE SOUTH COULD BRING SOME RAIN INTO THE REGION LATER
MONDAY AND INTO TUESDAY. HIGH TEMPERATURES ON TUESDAY ARE EXPECTED
TO BE BELOW NORMAL WITH MORE IN THE WAY OF CLOUD COVER AND
EASTERLY FLOW. LOW PRESSURE WILL BEGIN TO MOVE AWAY DURING
WEDNESDAY WITH IMPROVING CONDITIONS EXPECTED FOR MID TO LATE WEEK.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR INTO EARLY TONIGHT AND THEN CONDITIONS ARE EXPECTED
TO GO DOWN TO MVFR AND EVEN IFR AFTER MIDNIGHT INTO SATURDAY
MORNING. NORTHERN TERMINALS WILL CLEAR OUT BY MID MORNING ON
SATURDAY. KBGR AND KBHB WILL BE SLOWER TO CLEAR OUT DUE TO THE
SOUTHERLY FLOW.
SHORT TO LONG TERM: MVFR/IFR CONDITIONS ARE POSSIBLE IN SHOWERS
AND TSTMS SATURDAY NIGHT ESPECIALLY DOWN EAST AREAS. EXPECT VFR
ACROSS THE NORTH AND MVFR/IFR CONDITIONS EARLY SUNDAY IMPROVING TO
VFR ALL AREAS LATER SUNDAY. VFR SUNDAY NIGHT AND INTO MONDAY.
MVFR/IFR CONDITIONS POSSIBLE MONDAY NIGHT THROUGH MID WEEK IN RAIN
AND LOW CLOUDS.
&&
.MARINE...
NEAR TERM: NO HEADLINES WILL BE NEEDED ON THE WATERS THROUGH
MIDDAY SATURDAY. THINGS WILL CHANGE HOWEVER BY LATE AFTERNOON AS
THE GRADIENT TIGHTENS AHEAD OF THE APPROACHING COLD FRONT. DECIDED
TO INCREASE THE WIND SPEEDS TO 25 KTS ESPECIALLY W/THE GUSTS.
SEAS WILL COME UP AS WELL APPROACHING 5-6 FT ESPECIALLY OVER THE
OUTER ZONES BY 6 PM OR SO. FOG TONIGHT INTO EARLY SATURDAY
AFTERNOON WILL LEAD TO TRICKY NAVIGATION AS VSBYS COULD GO DOWN
BELOW 1 NM.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE SATURDAY
EVENING. WINDS AND SEAS MAY THEN INCREASE TO SCA LEVELS BY MID
WEEK.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 6 AM EDT
SUNDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...VJN/DUDA
MARINE...VJN/DUDA
AREA FORECAST DISCUSSION
NWS GRAY ME
1231 AM EDT SAT MAY 30 2015
.SYNOPSIS...
HIGH PRESSURE WILL RETURN TODAY AND MOVE OFF THE COAST OVER THE
WEEKEND ALLOWING A WARM AND HUMID SOUTHWEST FLOW TO RETURN.
ANOTHER COLD FRONT CROSSES THE REGION SUNDAY MORNING.
COOL...CANADIAN HIGH PRESSURE WILL BUILD BACK OVER THE REGION
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WILL CONTINUE A DENSE FOG ADVSRY FOR ALL MAINE COASTAL AREAS AND
MOST ADJACENT INLAND AREAS AS WELL. A WIDESPREAD AREA OF DENSE FOG
HAD DEVEPED ALONG THE COAST AND HAD PUSHED INLAND. THIS SHOULD
CONTINUE THE REST OF THE NIGHT AS THE LIGHT ONSHORE FLOW
CONTINUES.
720 PM UPDATE: OCEAN STRATUS/FOG HAS SPREAD FURTHER INLAND TO THE
ADJACENT COASTAL AREAS AT THIS TIME. MINOR ADJUSTMENT FOR
PLACEMENT OF LOW CLOUDS AND FOG FURTHER INLAND. ALSO MINOR TWEAKS
TO TEMPS BASED ON LATEST OBS.
PREVIOUS DISCUSSION:
MAIN FORECAST PROBLEM WILL BE MARINE STRATUS QUICKLY APPROACHING
THE COAST. HI-RES MODEL GUIDANCE ACTUALLY HAS A VERY GOOD HANDLE
ON THE CURRENT DEPICTION BASED ON VISIBLE SATELLITE. LEANING
HEAVILY ON THE NARRE AND HRRR FOR TIMING AND COVERAGE FOR THE
OVERNIGHT PERIOD. COASTAL ME...ESPECIALLY NEAR KPWM WILL SEE
STRATUS SOONEST...WITH ALL COASTAL AREAS LIKELY SEEING LOW CIGS BY
00Z. THRU THE NIGHT THIS WILL CREEP INLAND...AND SHOULD ROUGHLY
MATCH THE CURRENT SEA BREEZE FRONT OUTLINE. WINDS SHIFTING TO SWLY
WILL KEEP STRATUS CONFINED TO MAINLY THE GREAT BAY AREA AND E IN
SERN NH...WHILE ALLOWING IT TO PUSH AS FAR INLAND AS KAUG AND KWVL
IN CENTRAL ME.
WHILE CONFIDENCE IS HIGH IN LOW CLOUDS...CONFIDENCE IS SOMEWHAT
LOWER IN FOG AND DRIZZLE. THERE ARE SOME SIGNS BASED ON FORECAST
SOUNDINGS THAT THIS COULD DEVELOP OVERNIGHT. HRRR IS AGGRESSIVE ON
VSBYS BELOW 1/2 SM...WHILE NARRE IS A LITTLE MORE UP IN THE AIR.
SREF VSBYS PROBABILITIES OF GREATER THAN 80 PERCENT FOR LESS THAN
1 SM VSBY POINT TOWARDS SOME FOG MORE LIKELY THAT NOT. SO WILL
HAVE AREAS OF FOG IN THE GRIDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
GUSTY SW FLOW DEVELOPS AHEAD OF A SLOWLY APPROACHING COLD FRONT
SAT. THERE IS SUFFICIENT SHEAR FOR ORGANIZED STORMS ALONG THE
FRONT...BUT IT WILL DELAY IN REACHING THE FORECAST AREA. SREF
CALIBRATED SEVERE TSTM PROBABILITIES PEAK AROUND 21Z ACROSS THE
FAR NRN ZONES. ENVIRONMENT LOOKS FAIR ACROSS THIS AREA...SO WILL
ADD GUSTY WINDS TO THESE ZONES...AND DELAY TSTMS FOR COAST UNTIL
OVERNIGHT. THE OTHER THREAT TO WATCH WILL BE FLASH FLOODING. PWAT
VALUES WILL BE RUNNING HIGHER THAN NORMAL...AND SLOW FRONTAL
MOVEMENT COUPLED WITH TRAINING STORMS COULD YIELD SOME WATER
ISSUES. LOSS OF DAYTIME HEATING SHOULD HELP ANY STORMS TO WEAKEN
AND BECOME MORE SCATTERED...BUT A RENEWAL OF DEVELOPMENT IS
POSSIBLE EARLY SUN AS THE DAY HEATS UP AGAIN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
POSITIVELY TILTED SHORTWAVE TROUGH PUSHES THE COLD FRONT THE
REMAINDER OF THE WAY OFFSHORE SUNDAY MORNING WITH SHOWERS COMING
TO AN END IN THE EARLY AFTERNOON. DENSE HIGH PRESSURE TO OUR NORTH
MAKES LITTLE HEADWAY SOUTH HOWEVER AS ANOTHER WAVE OF LOW PRESSURE
MOVES ALONG THE OFFSHORE FRONT. LINGERING CLOUDS AND COOLER
CANADIAN AIR MOVING IN WILL KEEP THE MOUNTAINS COOL (MID 50S)
WHILE MUCH OF THE COASTAL PLAIN CLEARS OUT AND WARMS INTO THE
UPPER 60S ON SUNDAY. MONDAY AND TUESDAY WILL GENERALLY WARM INTO
THE 60S.
THE PROXIMITY OF OFFSHORE FRONTAL SYSTEM AS WELL AS A STEADY
STREAM OF SHORT WAVE ENERGY WILL KEEP A CHANCE OF SHOWERS OVER
SOUTHERN AND COASTAL SECTIONS OF NH AND MAINE THROUGH MONDAY.
THERE IS LITTLE INSTABILITY TO BE HAD BUT THERE MAY BE SOME
LIGHTNING OFFSHORE. FOLLOWING THIS A STOUT CUTOFF SHORT WAVE MOVES
TOWARDS THE AREA TUESDAY INTO WEDNESDAY MORNING ON NEARLY ZONAL
FLOW INCREASING RAIN CHANCES ACROSS THE ENTIRE AREA. HIGH PRESSURE
BUILDS IN BEHIND THIS SYSTEM BRINGING DRY AND WARM CONDITIONS
THURSDAY AND FRIDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...WIDESPREAD IFR/LIFR IS EXPECTED TONIGHT FOR COASTAL
TERMINALS AS MARINE STRATUS INVADES THE AREA. BETWEEN 21 AND 00Z
MOST SITES SHOULD BE IFR OR LOWER. KAUG MAY TAKE A COUPLE EXTRA
HOURS FOR LOW CIGS TO WORK INLAND...BUT BY 03Z IFR IS EXPECTED.
LOW CIGS PERSIST INTO SAT MORNING BEFORE LIFTING. GUSTY SW WINDS
AROUND 20 KTS POSSIBLE SAT AFTERNOON. TSTMS ARE POSSIBLE LATE SAT
INTO SUN FOR ALL TERMINALS. HIGHEST CONFIDENCE FOR TSTMS IS FOR
KHIE SAT EVENING.
LONG TERM...IMPROVING CONDITIONS SUNDAY WITH PERIODS OF MVFR IN
SHOWERS ALONG THE COAST CONTINUING THROUGH WEDNESDAY.
&&
.MARINE...
SHORT TERM...SW RETURN FLOW WILL INCREASE SAT. COOL WATERS SHOULD
LIMIT THE AMOUNT OF MIXING OF THE STRONGEST WINDS TO THE
SURFACE...BUT SUSTAINED FLOW SHOULD BUILD SEAS ABOVE 5 FT BY LATE
SAT. OCCASIONAL GUSTS TO 25 KTS ARE NOT OUT OF THE QUESTION
EITHER.
LONG TERM...WAVES DROP BELOW SCA CRITERIA SUNDAY MORNING. HIGH
SEAS RETURN MONDAY EVENING THROUGH TUESDAY NIGHT AS A TIGHT
PRESSURE GRADIENT SETS UP OVER THE WATERS.
&&
.FIRE WEATHER...
INCREASING HUMIDITY AND SOUTHWESTERLY BREEZES
WILL LEAD TO LATE AFTERNOON SHOWERS AND THUNDERSTORMS SATURDAY
AFTERNOON AND NIGHT. WETTING RAINS WILL BE MOST LIKELY IN THE
MOUNTAINS SATURDAY EVENING AND OVERNIGHT. THE AREAS NEAR THE COAST
WILL BE MORE LIKELY TO SEE WETTING RAINS SUNDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...DENSE FOG ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
MEZ019>028.
NH...NONE.
MARINE...NONE.
&&
$$ ..
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
127 AM EDT SAT MAY 30 2015
.UPDATE...
ISSUED AT 1047 PM EDT FRI MAY 29 2015 RAIN GENERALLY ACROSS THE ENTIRE UPPER
PENINSULA...HOWEVER IT SHOULD BE COMING TO AN END FAIRLY SOON ACROSS
THE FAR WEST AS DRIER AIR PER 00Z INL RAOB MOVES AND SUBSIDENCE INTO
THE AREA. REALLY NO MAJOR CHANGES TO THE FORECAST PLANNED. EXPECT
THE BACK EDGE OF THE RAIN TO STEADILY MOVE EAST ACROSS THE U.P.
TONIGHT. ANY REMAINING DENSE FOG NEAR THE LAKESHORE SHOULD ALSO
DIMINISH AS THE DRIER PBL AIRMASS UPSTREAM OF THE LAKE MOVES ACROSS.
STILL EXPECTING TEMPS TO DROP INTO THE LOWER 40S NORTH AND UPPER
40S/LOWER 50S SOUTH. ALREADY IN THE LOWER 40S NORTH OF THE LAKE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 423 PM EDT FRI MAY 29 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NRN MANITOBA INTO THE PLAINS RESULTING IN SW FLOW INTO THE WRN GREAT
LAKES. A SHORTWAVE TROUGH INTO SRN MN AND UPPER LEVEL DIV WITH THE
RIGHT ENTRANCE OF THE NRN STREAM 110 KNOT 250-300 JET OVER NRN
ONTARIO SUPPORTED A LARGE AREA OF SHOWERS AND SOME EMBEDDED TSRA
FROM SRN MN INTO WRN WI. AT THE SFC...A COLD FRONT EXTENDED FROM
NEAR CYQT-KMSP. WITH LITTLE MLCAPE AND MUCAPE VALUES IN THE 500-1000
J/KG RANGE ONLY OCNL ISOLD LIGHTNING WAS OBSERVED WITH THE SHOWERS
FROM NWN WI THROUGH UPPER MI AHEAD OF THE FRONT.
TONIGHT...MODELS SUGGEST THAT THE SFC FRONT WILL MOVE INTO CNTRL
UPPER MI BY 00Z/SAT AND THROUGH THE REST OF UPPER MI BY 06Z/SAT.
HOWEVER...A PERIOD OF POST-FRONTAL PCPN SUPPORTED BY MID LEVEL FGEN
AND UPPER LEVEL DIV WITH THE JET RIGHT ENTRANCE WILL SUPPORT
ADDITIONAL PCPN THROUGH 06Z WITH QPF OF 0.25 TO 0.50 INCH OVER
MAINLY THE CNTRL AND EAST PORTIONS OF THE CWA. UNLESS ISOLD LARGER
PCPN AMOUNTS OCCUR OVER THE AREAS WITH THE HIGHEST RAIN AMOUNTS FROM
EARLIER IN THE WEEK S CNTRL...RIVER RISES SHOULD REMAIN MODEST
KEEPING LEVELS BLO FLOOD THRESHOLD. WITH MOST OF THE INSTABILITY
REMAINING ALONG AND SOUTH OF THE FRONT...ONLY A FEW EMBEDDED TSRA
ARE EXPECTED.
SATURDAY...EXPECT LINGERING HIGH CLOUDS TO CLEAR FROM THE NW DURING
THE MORNING WITH BREEZY NRLY WINDS AND CAA THROUGH THE DAY KEEPING
TEMPS BELOW SEASONAL AVERAGES. 850 MB TEMPS FROM -1C TO 4C WILL
SUPPORT MAX READINGS RANGING FROM THE MID AND UPPER 40S OVER THE
NORTH WITH FLOW OFF LAKE SUPERIOR TO THE UPPER 50S SOUTH. TEMPS
RIGHT ALONG THE LAKE MAY EVEN STRUGGLE TO CLIMB THROUGH THE LOWER
40S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 439 PM EDT FRI MAY 29 2015
AFTER AN ACTIVE WEEK OF SUMMERLIKE WEATHER...A MUCH QUIETER WEATHER
PATTERN IS IN STORE THROUGH AT LEAST EARLY NEXT WEEK. COULD TURN
ACTIVE AGAIN BY LATE NEXT WEEK THOUGH.
CONFLUENT FLOW ALOFT ON SOUTHERN EDGE OF TROUGH OVER EASTERN CANADA
ALLOWS THE SFC HIGH OVER CNTRL CANADA TO SPREAD OVER THE GREAT LAKES
INTO SUNDAY. FROST/FREEZE IS LIKELY SATURDAY NIGHT. MOS GUIDANCE
SUGGESTS MID 20S AT FAVORED COLD SPOTS. GIVEN DRYNESS OF THE AIRMASS
COMING OVERHEAD WITH PWATS DOWN TO AROUND 0.20 INCH AND AFTN DWPNTS
ON SATURDAY DOWN TO AROUND 20 DEGREES AT THE LOWEST...ALL BUT
IMMEDIATE GREAT LAKES SHORELINES WILL SEE TEMPS BLO 30 DEGREES. COLD
HAS BEEN WELL ADVERTISED IN GRIDS/EHWO/HWO AND FORECAST FOR MANY
DAYS. COORD WITH GRB AND DECIDED TO HOLD OFF ON FROST/FREEZE
HEADLINES UNTIL SAT MORNING WITH CONTINUED THREAT OF SHRA/TSRA
STILL ONGOING TONIGHT.
COOL CONDITIONS REMAIN OVER REGION ON SUNDAY WITH TEMPS INLAND ONLY
AROUND 60 DEGREES. TEMPS WILL STAY IN THE 40S NEAR LK SUPERIOR WITH
ONSHORE LAKE BREEZE WINDS. HIGH IS STILL NEARBY ON SUNDAY NIGHT AND
PWATS ARE JUST AS LOW AS SATURDAY NIGHT. THUS...ANOTHER NIGHT OF
TEMPS AT OR BLO FREEZING AND FROST/FREEZE FOR THE INTERIOR. LIKELY
LOOKING AT MORE FROST/FREEZE HEADLINES.
TROUGHING ALOFT IN VCNTY ON MONDAY...PERHAPS EVEN MORE SO THAN
SUNDAY. AIRMASS STAYS DRY SO NOT MUCH IN WAY OF CLOUDS OR SHRA. AS
FLOW ALOFT BECOMES MORE ZONAL TO SOUTHWEST THROUGH REST OF THE LONG
TERM A WARMING TREND DEVELOPS. HIGHS ON MONDAY A TOUCH BLO NORMAL...
WITH TEMPS IN THE UPR 60S WEST AND AS COOL AS THE 50S NEAR GREAT
LAKES AS LAKE BREEZES DOMINATE. PWATS STILL BLO 0.30 INCHES ON
MONDAY NIGHT OVER THE EAST AND THE HIGH REMAINS CLOSE BY...SO COULD
SEE YET ANOTHER NIGHT OF SUB FREEZING TEMPS AND FROST. STARTED A
COOLER TREND BY GOING WITH MID TEMPS IN THE MID 30S IN THE TYPICAL
COLD SPOTS OF CNTRL AND EASTERN CWA. LIGHT SOUTH WINDS SHOULD KEEP
WEST AND GREAT LAKES SHORES WARMER THAN SAT NIGHT AND SUN NIGHT.
TEMPS ON TUESDAY SHOULD BE BACK AROUND NORMAL WITH HIGHS IN THE
LOWER 70S WEST AND ONLY AS COOL AS THE LOW 60S NEAR THE GREAT LAKES
SHORES.
SHOULD BE OUT OF THE CHILLY NIGHT PATTERN BY TUESDAY NIGHT WITH
RETURN FLOW ARRIVING OVER THE UPPER GREAT LAKES BTWN HIGH PRESSURE
CENTER OVER THE LOWER GREAT LAKES AND SFC TROUGHING OVER THE CENTRAL
AND NORTHERN PLAINS. WARM AIR ADVECTION WILL ALLOW SOME MOISTURE TO
SPILL ACROSS UPPER LAKES ON WEDNESDAY AHEAD OF MAIN TROUGH ALOFT
OVER THE WESTERN CONUS. ANY WEAK SHORTWAVE WITHIN THE WSW FLOW ALOFT
WOULD COMBINE WITH WARMER TEMPS /MID-UPR 70S/ AND BUILDING
INSTABILITY TO BRING SMALL SHRA/TSRA CHANCES BACK TO UPR MICHIGAN.
BEST CHANCES FOR SHRA/TSRA WILL BE THURSDAY INTO FRIDAY AS WEST-EAST
ORIENTED FRONTAL BOUNDARY SLOWLY DROPS ACROSS UPPER GREAT LAKES
WHILE INTERACTING WITH MORE ENERGIZED WSW FLOW ALOFT. DEPENDING ON
THE AMOUNT OF INSTABILITY AROUND DURING THAT TIME...PATTERN IS ONE
THAT COULD BE WARM AND HUMID AND ACTIVE WITH MULTIPLE ROUNDS OF TSRA
SLIDING OVER THE AREA IN THE VICINITY OF THE FRONTAL BOUNDARY. PWATS
OFF THE GFS RISE UP TO 1.5 TO 1.75 INCHES ALONG THE BOUNDARY...SO
HEAVY RAIN WOULD ALSO BE A CONCERN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 127 AM EDT SAT MAY 30 2015
THE FRONT HAS MOVED THROUGH THE UPPER PENINSULA...WITH CANADIAN HIGH
PRESSURE BUILDING QUICKLY BEHIND. THE REMAINING PRECIPITATION AND
IFR CIGS AT SAW SHOULD QUICKLY COME TO AN END IN THE NEXT FEW
HOURS...LEADING TO A GENERALLY QUIET AVIATION WEATHER DAY ON
SATURDAY WITH THE HIGH IN CONTROL. THERE MAY BE SOME NORTHERLY WIND
GUSTS TO 20 KT AT SAW...BUT OTHERWISE VFR CONDITIONS WILL PREVAIL.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT FRI MAY 29 2015
WINDS ARE EXPECTED TO STAY AT OR BELOW 20 KNOTS FOR MOST OF THIS
FORECAST PERIOD WITH THE EXCEPTION OF LATE TONIGHT THROUGH SATURDAY
WHERE THEY MAY INCREASE TO NEAR 30 KNOTS MAINLY ACROSS EASTERN LAKE
SUPERIOR BEHIND A COLD FRONT MOVING THROUGH THE REGION. FOG WILL
LINGER THROUGH INTO TONIGHT AND WILL BE DENSE AT TIMES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR
LSZ248>251-265>267.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...MRD
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...MRD
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1136 PM MDT FRI MAY 29 2015
.AVIATION...
06Z TAF CYCLE
AFTER 1ST ROUND OF SEVERE WX OVER THE EASTERN PLAINS THE 2ND BATCH
OF -TSRA IS DEVELOPING ALONG AND BEHIND THE BACK DOOR COLD FRONT.
EXPECT ACTIVITY TO BECOME WIDESPREAD AREA OF RA W/ EMBEDDED -TSRA.
GREATEST IMPACTS FROM LOW CIGS/VSBYS EXPECTED ALONG THE EAST SLOPE
SOUTH AND EAST TO NEAR KROW. GAP WINDS ENTERING THE RGV CURRENTLY
WITH GUSTS OF 25-30KTS. AWW CRITERIA TO 35KTS AT KABQ MAY OCCUR
BRIEFLY BUT CONFIDENCE LOW ON ISSUANCE. CLOUDS AND RAIN WILL VERY
SLOWLY EXIT THE EAST AFT SUNRISE SATURDAY. -SHRA/TSRA WILL DEVELOP
AROUND THE HIGH TERRAIN OF CENTRAL/WESTERN NM AFT 21Z WHERE THE
FOCUS OF THE CURRENT FRONTAL BOUNDARY WASHES OUT.
GUYER
&&
.PREV DISCUSSION...939 PM MDT FRI MAY 29 2015...
.UPDATE...
UPDATED GRIDS TO REMOVE THE SEVERE T STORM WATCH HEADLINES AND THE
SEVERE WORDING...THOUGH A FEW STRONG STORMS COULD REDEVELOP A
COUPLE HOURS EITHER SIDE OF MIDNIGHT. LATEST NAM MORE BULLISH FOR
SE THIRD OF NM WHILE HRRR MODEL INDICATES MORE THE NE THIRD OR SO
OF THE STATE. ONLY A FEW MODEST SHOWERS UP IN NE AS OF THIS
ISSUANCE. THUS TRIMMED BACK POPS SIGNIFICANTLY FOR REST OF PRE
MIDNIGHT HOURS WITH LESS SIGNIFICANT CUTTING BACK AFTER MIDNIGHT
AS AT LEAST SOME ADDITIONAL DEVELOPMENT EXPECTED. ZONE FCST
PRODUCT ALREADY OUT.
43
&&
.PREV DISCUSSION...316 PM MDT FRI MAY 29 2015...
.SYNOPSIS...
THE WARMING AND DRYING TREND CONTINUES TODAY WITH ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS FOCUSING ACROSS NORTHEAST AND EAST
CENTRAL PORTIONS OF THE AREA WHERE A FEW STORMS MAY BECOME SEVERE.
A BACKDOOR COLD FRONT WILL PUSH SOUTHWEST ACROSS THE AREA TONIGHT
INTO SATURDAY RESULTING IN GUSTY EAST CANYON/GAP WINDS IN THE RIO
GRANDE AND UPPER TULAROSA VALLEYS. SOME COOLING SATURDAY BEHIND
THE FRONT ACROSS THE EASTERN PLAINS WILL RESULT IN A DOWNTREND IN
THUNDERSTORMS THERE...BUT MOISTURE MOVING IN BEHIND THE FRONT WILL
RESULT IN A ROUND OF LATE DAY THUNDERSTORMS OVER THE CENTRAL AND
WESTERN MOUNTAINS. THE WARMING TREND RESUMES SUNDAY WITH ANOTHER
ROUND OF AFTERNOON AND EVENING THUNDERSTORMS FORECAST.
TEMPERATURES WILL GENERALLY BE ABOVE NORMAL NEXT WEEK AS A RIDGE
OF HIGH PRESSURE SHIFTS OVERHEAD AND DRY AIR MOVES IN BEHIND IT
LEADING TO A SEVERAL DAYS WITH LITTLE TO NO CHANCE FOR
THUNDERSTORMS.
&&
.DISCUSSION...
ROUND OF CONVECTION ONGOING ACROSS THE NORTHEAST HIGHLANDS INTO
THE NORTHEAST AND EAST CENTRAL PLAINS. HOWEVER...SURFACE BASED
INSTABILITY IS NOT AS IMPRESSIVE AS YESTERDAY WITH DEWPOINT
TEMPERATURES 5-10 DEGREES LOWER...BUT WITH MUCH IMPROVED
DIRECTIONAL SHEAR SEVERE STORMS ARE IMMINENT. A SEVERE
THUNDERSTORM WATCH WAS JUST ISSUED FOR MUCH OF THE EAST. THE
BACKDOOR FRONT WILL CONTINUE TO PROVIDE A FOCUS FOR INITIATION
THROUGH THE AFTERNOON AND EARLY EVENING HOURS ACROSS THE NORTHEAST
AND EAST CENTRAL PLAINS. THE 18Z NAM IS SHOWING A WEAK SHORTWAVE
TROUGH MOVING SOUTHEAST ACROSS SOUTHERN COLORADO AND NE NEW MEXICO
OVERNIGHT WITH RENEWED CHANCES FOR STORMS ACROSS THE EASTERN
PLAINS/HIGHLANDS.
THE BACKDOOR FRONT IS STILL FORECAST TO PUSH THROUGH THE CENTRAL
MOUNTAIN CHAIN TONIGHT...RESULTING IN GUSTY EAST CANYON/GAP WINDS
IN THE BRIO GRANDE AND UPPER TULAROSA VALLEYS. WINDS ARE
CURRENTLY FORECAST JUST BELOW ADVISORY CRITERIA. WESTWARD LOW
LAYER MOISTURE TRANSPORT IN THE FRONTAL LAYER THROUGH SATURDAY
WILL RESULT IN A LATE-DEVELOPING ROUND OF STORMS ALONG THE CENTRAL
AND WESTERN HIGHER TERRAIN WITH MOVEMENT OFF TO THE SOUTH OR
SOUTHEAST INTO THE EVENING HOURS.
A RIDGE OF HIGH PRESSURE WILL SHIFT OVER THE AREA SUNDAY INTO
MONDAY WITH 500MB HEIGHTS REACHING UP TO 588-589DAM...WHICH WILL
BE MORE THAN SUFFICIENT TO BRING-ON A RENEWED WARMING TREND.
SLOW-MOVING DAYTIME HEATING TRIGGERED STORMS ARE FORECAST SUNDAY
AND MONDAY...FOLLOWING NORMAL DIURNAL TRENDS. HIGHS WILL ACTUALLY
BE ABOVE NORMAL MOST AREAS MONDAY THROUGH AT LEAST WEDNESDAY AS
THE RIDGE AXIS SHIFT EAST AND DRY WESTERLIES PUNCH IN...WITH A
BROAD LOW AMPLITUDE TROUGHING PATTERN OVER THE WESTERN CONUS. NEXT
WEEK WILL CERTAINLY FEEL MORE SEASONAL THAN WHAT WE SAW FOR MUCH
OF MAY.
11
&&
.FIRE WEATHER...
DRIER CONDITIONS WITH ISOLATED HIGHER BASED SHOWERS/STORMS WILL
IMPACT WESTERN/CENTRAL AREAS REST OF TODAY INTO THIS EVENING.
GUSTY OUTFLOW WINDS WOULD BE THE MAIN THREAT FROM THIS ACTIVITY.
DRYLINE STORMS OF THE WETTER VARIETY WOULD BE FOUND ACROSS THE
EASTERN PLAINS. THIS ACTIVITY SHOULD GO WELL INTO THE OVERNIGHT
HOURS AND ACTUALLY ENHANCE IN SPATIAL COVERAGE DUE TO A BACK DOOR
COLD FRONTAL PLUNGE. HIGHER DEWPOINTS AND HUMIDITY WILL GET PUSHED
WESTWARD OVERNIGHT DUE TO THE FRONTAL PUSH AND MAKE IT TO THE
CONTINENTAL DIVIDE...PERHAPS A BIT FURTHER.
THE HIGHER MOISTURE WILL SET THE STAGE FOR SOME WETTING RAIN
POSSIBILITIES BETWEEN THE DIVIDE AND CENTRAL MTNS AND ADJACENT HIGH
PLAINS ON SATURDAY. HUMIDITY VALUES WILL BE HIGHER ACROSS
WESTERN/CENTRAL AREAS COMPARED TO TODAYS RESULTS. TEMPS WILL ALSO
COOL AND BE NEAR TO ABOVE NORMAL ALONG AND WEST OF THE DIVIDE AND
BELOW NORMAL TO THE EAST OF THE DIVIDE. THE SURFACE WIND FLOW IS NOT
EXPECTED TO BE TOO STRONG EXCEPT FOR NEAR THE CENTRAL MTN GAPS
DURING THE MORNING HOURS.
THE SUBTROPICAL RIDGE IS STILL DEPICTED TO BUILD OVER THE AREA
SUNDAY THROUGH EARLY NEXT WEEK. MOISTURE TRAPPED WITHIN THE RIDGE
WILL GRADUALLY MIX OUT IN THE FORM OF ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS. THIS ACTIVITY WILL TREND DRIER AS THE DAYS
PROGRESS AND LOOK FOR SMALL FOOTPRINTS OF MARGINALLY WETTING RAIN BY
MONDAY. GUSTY OUTFLOW WINDS WOULD REMAIN A CONCERN. THE ACTIVITY
SHOULD BE MUCH LESS BY TUESDAY. BOTH THE ECMWF/GFS SUPPORT THIS
TREND. ECMWF IS A BIT MORE BULLISH FOR DRYLINE STORMS ACROSS THE
EAST ON TUESDAY HOWEVER.
THE SURFACE WIND GRADIENT SHOULD PICK UP DURING THE EARLIER HALF OF
NEXT WEEK AS THE RIDGE GRADUALLY BREAKS DOWN AND ALLOWS THE WINDS
ALOFT TO STRENGTHEN. ABUNDANT MIXING HEIGHTS SHOULD LEAD TO DEEP
MIXING AND PROVIDE GUSTIER WIND FLOWS...ESPECIALLY TUES/WED. WENT A
LITTLE ABOVE MODEL GUIDANCE FOR THIS PERIOD. DRY SLOTTING WILL ALSO
LOWER SURFACE HUMIDITY VALUES AND PROVIDE SEVERAL HOURS OF SINGLE
DIGITS ACROSS WESTERN/CENTRAL AREAS. LOCALIZED STRONG WIND/LOW
HUMIDITY AND HIGHER HAINES VALUES WILL START TO SHOW UP DURING THIS
PERIOD ALTHOUGH FUEL CONDITIONS ARENT TOO BAD...ESPECIALLY WITH AN
INFLUX OF GREENUP. CONFIDENCE IS MODERATE TO HIGH BASED ON THE
RECENT TRENDS IN THE MODELS BUT THIS WOULD BE A PATTERN CHANGE OF
SORTS.
ANOTHER PACIFIC TROUGH MAY SHARPEN UP TO THE WEST DURING LATE NEXT
WEEK AND COULD PROVIDE ANOTHER ROUND OF SHOWERS/STORMS ACROSS THE
FORECAST AREA. ECMWF MODELS APPEARS TO BE MORE BULLISH FOR THAT
TREND VERSUS THE GFS BUT WILL MONITOR. STORMS COULD INITIALLY START
OUT ON THE DRIER SIDE ACROSS WESTERN/CENTRAL AREAS.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
157 AM EDT SAT MAY 30 2015
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BE OVER THE REGION THROUGH EARLY
SATURDAY. A STRONG SURFACE COLD FRONT WILL APPROACH FROM THE
NORTHWEST SATURDAY AFTERNOON AND CROSS THE AREA OVERNIGHT. THIS
FRONT WILL STALL OUT SOUTH OF OUR FORECAST AREA AND BECOME A FOCUS
FOR SEVERAL WAVES OF SHOWERS DURING THE FIRST PART OF THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1009 PM EDT FRIDAY...MOSTLY CLEAR SKIES/FEW HIGH CLOUDS AND
LIGHT, DECOUPLED WINDS THUS FAR THIS EVENING HAVE ALLOWED HOURLY
TEMPS TO FALL A BIT MORE QUICKLY THAN PRIOR EXPECTATIONS IN THE
ST. LAWRENCE VALLEY. SO THE MAIN ADJUSTMENT WITH THIS UPDATE WAS
TO LOWER MIN TEMPS BY A FEW DEGREES THROUGH MIDNIGHT. HOWEVER, AS
WINDS STRENGTHEN FROM THE SOUTHWEST AFTER MIDNIGHT AND WARM/MOIST
ADVECTION BEGINS, SHOULD SEE TEMPS HOVER STEADY AND RISE INTO THE
MORNING HOURS. LATEST HRRR GUIDANCE CONTINUES TO SUGGEST SPOTTY
LIGHT SHOWERS IN THE ST. LAWRENCE VALLEY AND ADIRONDACKS AREAS
LATER IN THE OVERNIGHT, SO ULTIMATELY OPTED TO KEEP SLIGHT CHANCE
OF SHOWERS GOING. LOWS GENERALLY IN THE UPPER 50S TO MID/UPPER
60S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 415 PM EDT FRIDAY...COLD FRONT APPROACHES FROM THE
NORTHWEST SATURDAY AND SHOWERS AND THUNDERSTORMS DEVELOP OUT AHEAD
OF THIS FEATURE ON SATURDAY AFTERNOON. BEST CHANCE FOR
THUNDERSTORMS APPEARS TO BE AFTER 18Z...AND MAINLY NORTHERN NEW
YORK AND THE CHAMPLAIN VALLEY. OUR REGION CONTINUES TO BE UNDER A
MARGINAL RISK OUT OF SPC. BETTER DYNAMICS AND STRONGER SHEAR WILL
BE WELL NORTH OF THE AREA...CLOSER TO STRONG SHORT WAVE TROF
MOVING ACROSS ONTARIO AND QUEBEC. DAYTIME MAX TEMPS WILL REACH THE
MID 70S TO MID 80S. CAPE VALUES REACH OVER 2000 IN THE SAINT
LAWRENCE VALLEY. OVERNIGHT AS THE FRONT CONTINUES ACROSS OUR
FORECAST AREA AND WITH LOSS OF DAYTIME HEATING EXPECT CONVECTION
TO END AND JUST SOME SHOWERS CONTINUING. COLD FRONT WILL STALL OUT
TO OUR SOUTH AND BECOME THE FOCUS FOR SEVERAL ROUNDS OF
PRECIPITATION. SUNDAY NIGHT WILL SEE SHOWERS MOVE ACROSS NEW YORK
AND SOUTHERN NEW ENGLAND...HAVE SOME LIKELY POPS MENTIONED IN OUR
SOUTHERN ZONES. TEMPERATURES WILL BE MUCH COOLER ON SUNDAY AS
REGION IS IN THE COOL SECTOR BEHIND COLD FRONT...MAX TEMPS WILL
ONLY BE IN THE UPPER 50S AND LOWER 60S...A GOOD 20 DEGREES COOLER
THAN SATURDAY. SUNDAY NIGHT TEMPERATURES WILL DROP INTO THE 40S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 400 PM EDT FRIDAY...RATHER TRANQUIL EXTENDED FORECAST PERIOD
FORESEEN BASED ON CONSENSUS OF 00Z GFS/GFS ENSEMBLE MEAN AND 00Z
ECMWF. DEEP-LAYER NWLY FLOW ON ERN PERIPHERY OF SFC ANTICYCLONE
BUILDING EWD FROM THE GREAT LAKES REGION WILL PROVIDE DRIER
CONDITIONS AND MORE SEASONABLE TEMPERATURES TO START THE PERIOD
WEDNESDAY NIGHT. ANTICIPATE MOSTLY CLEAR SKIES...AND IF SURFACE
WINDS DROP OFF SUFFICIENTLY...SHOULD SEE OVERNIGHT LOWS RANGING
FROM NEAR FREEZING IN THE NORTHERN ADIRONDACKS AND FAR
NORTHEASTERNVT...TO AROUND 40F IN THE CHAMPLAIN VALLEY REGION.
AFOREMENTIONED SURFACE HIGH BUILDS SLOWLY EWD ACROSS THE
NORTHEASTERN CONUS PROVIDING PLEASANT/MOSTLY CLEAR CONDITIONS
THURSDAY THROUGH AT LEAST THE FIRST HALF OF FRIDAY. HIGHS WILL BE
IN THE MID 60S THURSDAY...BEFORE MODERATING BACK INTO THE LOW 70S
ON FRIDAY.
SOME DIFFERENCES BETWEEN 00Z GFS AND 00Z ECMWF CONCERNING
POTENTIAL SHORTWAVE TROUGH MOVING EWD FROM THE GREAT LAKES FRIDAY
NIGHT INTO SATURDAY. THE GFS IS MORE ROBUST WITH THIS
FEATURE...AND TRACKS STRONGEST UVV ACROSS OUR SRN ZONES LATE
FRIDAY NIGHT INTO SATURDAY. THE 00Z ECMWF - ON THE OTHER HAND -
KEEPS BEST PRECIPITATION CHANCES TO OUR SOUTH. THE OFFICIAL
FORECAST INDICATES SOME INCREASING CLOUDS LATER FRIDAY...FOLLOWED
BY 15-30 POPS FOR SHOWER ACTIVITY FRIDAY NIGHT THRU
SATURDAY...WITH HIGHEST POP VALUES ACROSS SRN ZONES. CLOUDS COULD
KEEP TEMPS IN THE UPR 60S TO AROUND 70F FOR SATURDAY...BEFORE
TRENDING WARMING (LOW-MID 70S) WITH BETTER POTENTIAL FOR SUNSHINE
ON SUNDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...VFR (POSSIBLE MVFR MIST AT MPV) WITH
INCREASING SOUTH WINDS TOWARDS MORNING. PRIMARY AVIATION FOCUS
WILL BE IN THE LATTER HALF OF THE TAF PERIOD...DUE TO GUSTY SOUTH
WINDS AND POTENTIAL FOR SHOWERS AND THUNDERSTORMS SATURDAY
AFTERNOON/EVENING.
MOSTLY CLEAR WITH SCT-BKN CIRRUS CLOUDS OVERNIGHT. CONTINUED MID-
TO HIGH CLOUDS INTO SATURDAY. STRENGTHENING GRADIENT AHEAD OF
SURFACE COLD FRONT SHOULD ALSO ALLOW FOR SOUTHERLY WINDS TO
FURTHER INCREASE INTO THE 10-18 KT RANGE WITH GUSTS 25-28 KTS.
SHOWER/THUNDERSTORM COVERAGE LIKELY TO BE MORE SCATTERED...BUT
SOME COULD TURN STRONG WITH GUSTY OUTFLOW WINDS...LIGHTNING AND
REDUCED VISIBILITY IN HEAVY DOWNPOURS. BEST SHOT AT SEEING THIS
ACTIVITY AFTER 18Z WOULD BE AT MSS AND SLK...AND AFTER 22Z AT
REST OF SITES.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
PERIODS OF RAIN SATURDAY NIGHT WITH DEVELOPING N-NW WINDS BEHIND
SURFACE COLD FRONT. TRENDING VFR ACROSS NORTHERN AREAS DURING THE
DAYLIGHT HOURS SUNDAY...BUT STALLING FRONTAL ZONE MAY RESULT IN
POSSIBLE MVFR SHOWERS AT TIMES SUNDAY NIGHT INTO MONDAY...MAINLY
FOR RUT/MPV. AVIATION WX CONDITION PREDICTABILITY LOW AT THIS
POINT FROM MONDAY NIGHT THRU WEDNESDAY.
&&
.MARINE...
AS OF 400 PM EDT FRIDAY...A COLD FRONT WILL MOVE ACROSS THE AREA
SATURDAY AFTERNOON AND OVERNIGHT. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED. A LAKE THUNDERSTORM ADVISORY MAY BE
NEEDED FOR LAKE CHAMPLAIN SATURDAY AFTERNOON AND SATURDAY NIGHT.
SOUTH WINDS WILL INCREASE TO 15 TO 25 KNOTS ON SATURDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES/LOCONTO
SHORT TERM...NEILES
LONG TERM...BANACOS
AVIATION...RJS/LOCONTO
MARINE...NEILES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
413 AM EDT SAT MAY 30 2015
.SYNOPSIS...
MOISTURE ASSOCIATED WITH LOW PRESSURE AND A SLOW MOVING COLD FRONT
WILL BRING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS TODAY
THROUGH SUNDAY. HIGH PRESSURE WILL BRING COOLER AND DRIER AIR FOR
THE BEGINNING OF THE WORK WEEK. WARMER TEMPERATURES WILL RETURN
LATER NEXT WEEK AS THE HIGH TRAVELS SLOWLY EASTWARD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AREA IS IN A PERSISTENTLY HUMID SOUTHERLY FLOW BETWEEN HIGH
PRESSURE CENTERED TO THE EAST AND A LOW PRESSURE SYSTEM TO THE
WEST. ISOLATED SHOWERS HAVE DISSIPATED EARLY THIS MORNING LEAVING
PARTLY TO MOSTLY CLOUDY SKIES. LATEST RAP SHOWS PRECIP DEVELOPING
WITHIN THE NEXT COUPLE OF HOURS BUT THIS APPEARS OVERDONE. WILL
CONTINUE TO MONITOR.
A SURFACE LOW FORMING OVER MISSOURI AT THE TAIL END OF A COLD
FRONT WILL MOVE TO ILLINOIS THIS AFTERNOON. EXPECT SHOWERS AND
THUNDERSTORMS TO REDEVELOP TODAY AS INSTABILITY AND FORCING
INCREASES AHEAD OF THE LOW...ESPECIALLY THIS AFTERNOON DURING PEAK
HEATING. BEST CHANCE FOR CONVECTIVE DEVELOPMENT WILL BE IN
NORTHWEST COUNTIES CLOSER TO THE AXIS OF AN UPPER TROUGH CENTERED
OVER THE MISSISSIPPI VALLEY. A FEW STRONG THUNDERSTORMS WILL BE
POSSIBLE THIS AFTERNOON BUT RATHER WEAK INSTABILITY AND WIND SHEAR
WILL LIMIT SEVERE POTENTIAL.
HIGH TEMPERATURES WILL REACH THE LOWER TO MIDDLE 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THERE MAY BE A TEMPORARY LULL IN CONVECTION THIS EVENING WITH LOSS
OF DAYTIME HEATING. BY LATER TONIGHT...SURFACE LOW PRESSURE PUSHED
TO OHIO BY THE UPPER TROUGH WILL PRODUCE A NOTABLE INCREASE IN
FORCING. SHOWERS AND THUNDERSTORMS ARE A NEAR CERTAINTY IN
NORTHERN COUNTIES THAT WILL BE ON THE NORTH SIDE OF THE LOW TRACK. A
POTENT LOW LEVEL JET...COPIOUS MOISTURE AND A BAND OF DEFORMATION
WILL ALL COME INTO PLAY TO PRODUCE PERHAPS AS MUCH AS TWO INCHES
OF RAIN IN NORTHERN LOCATIONS. RAIN CHANCES WILL DECREASE TOWARD
THE SOUTH AWAY FROM THE MOST FAVORABLE FORCING.
WIDESPREAD SHOWERS WILL DIMINISH SUNDAY AS THE LOW MOVES EAST AND
THE LOW LEVEL FLOW BECOMES NORTHWEST. THUNDERSTORMS WILL BE LESS
EVIDENT ON SUNDAY IN A REGIME OF DECREASING INSTABILITY. HIGH
PRESSURE AND A DRY AIRMASS WILL MOVE IN MONDAY ON A NORTHWEST
FLOW ALOFT.
THE NORTHERLY LOW LEVEL FLOW BEHIND THE LOW WILL BRING COOLER
TEMPERATURES. HIGHS ON SUNDAY WILL VARY FROM THE LOW 60S NORTHWEST
UP TO THE UPPER 70S SOUTHEAST. HIGHS IN THE 60S ARE EXPECTED IN
MOST LOCATIONS ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
FORECAST HAS SHIFTED IN TIMING RETURN FLOW TO THE OHIO VALLEY. A
SLOWER SHIFT OF WINDS IN THE TUES-THURS TIME FRAME FROM EAST TO
EVENTUALLY SOUTH HAS HELPED KEEP A DRIER AND COOLER FORECAST FOR THE
BETTER PART OF NEXT WEEK.
A LARGE AREA OF HIGH PRESSURE NORTH OF THE GREAT LAKES REGION WILL
EXTEND A RIDGE SOUTHWEST INTO THE NORTHERN OHIO VALLEY TUESDAY THROUGH
WEDNESDAY. THE HIGH WILL SETTLE IN THE OHIO VALLEY ON WEDNESDAY
AND THEN MEANDER EASTWARD OVERNIGHT AND THURSDAY.
WITH THE NORTHEAST TO EAST WINDS HOLDING SWAY OVER THE REGION
THROUGH THIS TIME...HAVE REMOVED POPS UNTIL THURS AFTERNOON WHEN
SOME RETURN TO SOUTHERLY FLOW AND INCREASED MOISTURE WOULD BE
EXPECTED. TEMPS THROUGH THIS TIME WILL BE BELOW NORMAL...STARTING
WITH HIGHS IN THE UPPER 60S TO LOW 70S MONDAY RISING TO AROUND 80
WEDNESDAY AND LOW TO MID 80S FOR THE END OF THE WEEK. DRIER AIR WILL
PERMIT LOWS TO DIP INTO THE 50S MON NIGHT AND INCREASE TO AROUND 60
WED NIGHT...JUMPING TO THE MID 60S WHEN THE FLOW TURNS SOUTH AND
MOISTURE INCREASES LATE IN THE FORECAST.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
CAN/T RULE OUT A STRAY SHOWER DEVELOPING PRIOR TO SUNRISE...BUT
CHANCE IS TOO LOW TO MENTION IN TAFS. IN MOIST FLOW...EXPECT
POTENTIAL FOR MVFR VIS IN BR AT KLUK...OTHERWISE VFR THIS MORNING.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON/EARLY EVENING...CONTINUED VCTS IN TAFS. IT LOOKS LIKE
MOST OF THE MID TO LATE EVENING SHOWER/THUNDERSTORM ACTIVITY WILL
RESIDE JUST NORTHWEST OF THE TERMINALS CLOSER TO A FRONT/LOW
PRESSURE...BUT CHANCES MAY START TO INCREASE AGAIN TOWARD THE
DAY/CVG TERMINALS CLOSE TO 06Z.
OUTLOOK...SHOWERS AND THUNDERSTORMS ARE POSSIBLE SUNDAY.
POTENTIAL EXISTS FOR MVFR OR IFR CIGS LATE SUNDAY THROUGH MONDAY
MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...CONIGLIO
SHORT TERM...CONIGLIO
LONG TERM...FRANKS
AVIATION...BPP
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
424 AM CDT SAT MAY 30 2015
.DISCUSSION...
EARLY MORNING GOES WATER VAPOR IMAGERY SHOWED A WELL DEFINED UPPER
LEVEL SHORTWAVE CENTERED JUST SOUTH OF FORT SMITH AR...MOVING
EAST. NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS WERE SPREADING
NORTHEAST THROUGH EASTERN AR AHEAD OF THIS FEATURE.
SHOWERS AND THUNDERSTORMS WILL LIKELY SPREAD EAST THROUGH MOST OF
THE MIDSOUTH THIS MORNING. 07Z HRRR MODEL SHOWS BEST RAIN CHANCES
SHIFTING TO NORTHEAST MS AND AREAS OF WEST TN NEAR THE TN RIVER BY
MIDAFTERNOON. A FEW WRAP AROUND SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE FURTHER WEST...ALONG AND BEHIND A SURFACE COLD FRONT. ANY
WRAP AROUND SHOWERS SHOULD DISSIPATE THIS EVENING... AS THE
SHORTWAVE LIFTS OUT AND DAYTIME HEATING ENDS.
A SECONDARY SHORTWAVE WILL DROP FROM THE OZARKS INTO THE MIDSOUTH
ON SUNDAY...WITH NORTHEAST MS BEST POSITIONED TO RECEIVE
MEASURABLE RAINFALL. THIS SECONDARY SHORTWAVE WILL EXIT SUNDAY
EVENING... LEAVING DRIER DEEP NORTHWEST FLOW PREVAILING OVER ALL
OF THE MIDSOUTH BY SUNDAY NIGHT.
THE MONDAY THROUGH WEDNESDAY PERIODS APPEAR DRIER THAN EARLIER
FORECAST...WITH WEAKENING NORTHWEST FLOW ALOFT GIVING WAY TO
AN ENCROACHING UPPER LEVEL RIDGE FROM THE SOUTHERN PLAINS. THE
GFS AND ECMWF MODELS CONTINUE TO SHOW DIFFERING SOLUTIONS TO A
DEVELOPING CUTOFF LOW OVER THE SOUTHEAST STATES. NEITHER MODEL
RETROGRADES THE UPPER LOW SUFFICIENTLY TO BRING APPRECIABLE RAIN
CHANCES TO THE MIDSOUTH UNTIL LATER IN THE WEEK...AND ONLY THE GFS
SHOWS THIS SCENARIO. IF THE ECMWF VERIFIES...WE MAY SEE LOWER 90S
OVER MUCH OF THE MIDSOUTH LATE IN THE WEEK. FOR NOW...HAVE KEPT
THE EXTENDED FORECAST HIGHS NEAR THE MODEL ENSEMBLE AVERAGE...BUT
THERE MAY BE A WARMER TREND DEVELOPING FOR LATER NEXT WEEK.
PWB
&&
.AVIATION...
06Z TAF CYCLE
NUMEROUS SHOWERS AND THUNDERSTORMS WILL GRADUALLY MOVE INTO THE
REGION FROM THE WEST OVERNIGHT IN ASSOCIATION WITH AN UPPER LEVEL
TROUGH. SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS THE REGION
SATURDAY AS THE UPPER LEVEL TROUGH CONTINUES EASTWARD. CEILINGS
LOWERING TO IFR BY LATE TONIGHT AT KMEM...KMKL AND KTUP...MVFR AT
KJBR. CEILINGS BECOMING MVFR OUTSIDE SHOWERS AND THUNDERSTORMS
ACROSS THE ENTIRE AREA AFTER 30/17Z. WINDS TONIGHT SOUTHERLY 7-10
KTS. WINDS SATURDAY SW INCREASING TO NEAR 12 KTS WITH GUSTS TO 20
KTS. WINDS TURNING MORE WESTERLY AT KJBR DURING THE AFTERNOON.
AFTER 31/00Z...VFR CONDITIONS WILL OCCUR AS SHOWER AND THUNDERSTORMS
MOVE EAST OF THE AREA. WINDS TURNING TO W AND NW 6-8 KTS.
JCL
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1234 AM CDT SAT MAY 30 2015
.AVIATION...
AN MCS CURRENTLY FROM N OF KABI TO N OF KMAF WILL MOVE TO THE SE
OVERNIGHT INTO CENTRAL TEXAS TO EDWARDS PLATEAU BY SATURDAY
MORNING PRIOR TO WEAKENING. OUTFLOW BOUNDARIES FROM THIS MCS AND A
COLD FRONTAL PASSAGE WILL LEAD TO SHRA/TSRA LATER IN THE DAY INTO
SATURDAY NIGHT. HAVE GONE WITH A BLEND OF MORE RECENT HRRR RUNS
AND TTU WRF WITH PROB30S FOR THE TAF SITES IN THE AFTERNOON INTO
EVENING AND VCSH OTHERWISE. VFR FLYING CONDITIONS WILL TURN MVFR
AND POSSIBLY IFR OVERNIGHT AS STRATUS AND BR DEVELOP. CONDITIONS
RETURN TO VFR LATE MORNING TO MIDDAY. BRIEF MVFR/IFR CIGS ARE
POSSIBLE IN SHRA/TSRA. SOME MVFR CIGS REDEVELOP SATURDAY EVENING.
S TO SE WINDS 5 TO 10 KTS WILL TURN TO N TO NE WITH THE OUTFLOW
BOUNDARY AND FRONTAL PASSAGE. SOME GUSTS TO 50 KTS AND GR ARE
POSSIBLE IN AND NEAR TSRA.
&&
.PREV DISCUSSION... /ISSUED 658 PM CDT FRI MAY 29 2015/
AVIATION... /00Z TAF UPDATE/
NO CONVECTION IS EXPECTED TO IMPACT TAFS FOR THE FIRST 9-12 HOURS.
SATURATED SOILS SHOULD INTERACT WITH MODERATE SURFACE SOUTHERLIES
TO FORM LOW CLOUDS BEFORE MIDNIGHT...WITH PERHAPS A SLIGHT DELAY
OVER THE RIO GRANDE PLAINS AND THE DRT AREA. NOCTURNAL BOUNDARY
LAYER WIND ENHANCEMENTS LOOK CONSERVATIVE IN MODEL TIME
SECTIONS...SUGGESTING AN ABUNDANCE OF IFR CONDITIONS LATE TONIGHT.
A WEAKENING STORM COMPLEX IS EXPECTED OVER CENTRAL TX BY
DAYBREAK...POSSIBLY A BIT FASTER IF RECENT RUNS OF THE HRRR
VERIFY. WILL STICK WITH THE MORE CONSERVATIVE TX TECH WRF AND THE
COARSER SCALE MODELS FOR THIS EVENING...AS THE LATE
AFTERNOON/EARLY EVENING RUNS OF THE HRRR HAVE SEEMED TO BE RUNNING
TOO AGGRESSIVE OVER THE PAST WEEK.
PREV DISCUSSION... /ISSUED 254 PM CDT FRI MAY 29 2015/
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
.LOCALLY HEAVY RAINFALL POSSIBLE SATURDAY ACROSS SOUTH CENTRAL
TEXAS...
RECOVERY AFTER LAST NIGHTS MCS IS SLOWLY TAKING PLACE WEST TO
EAST ACROSS THE CWA. CAN NOT COMPLETELY RULE OUT AN ISOLATED
STORM THROUGH SUNSET...BUT THE MAJORITY OF THE CWA WILL REMAIN
DRY THROUGH THE REMAINDER OVER THE AFTERNOON AND EVENING.
UPSTREAM...MODELS ARE INDICATING ANOTHER ORGANIZED COMPLEX OF
STORMS DEVELOPING THIS EVENING ACROSS NORTHWEST TEXAS MOVING
SOUTHEAST THROUGH WEST-CENTRAL TEXAS OVERNIGHT. PAST FEW HRRR
RUNS AND 12Z TT 4KM WRF ARE INDICATING THIS POTENTIAL LINE OF
STORMS REACHING THE NORTHERN HILL COUNTRY 09Z-12Z. UNLIKE LAST
NIGHT...THIS COMPLEX MAY WEAKEN AS IT MOVES INTO THE HILL COUNTRY
AND CENTRAL TEXAS SATURDAY MORNING. HOWEVER...OUTFLOW BOUNDARIES
LEFT OVER AND AN EVENTUAL WEAK COLD FRONT...WILL LIKELY TRIGGER
ADDITIONAL SHOWERS AND STORMS SATURDAY AFTERNOON AND EVENING
ACROSS MUCH OF SOUTH-CENTRAL TEXAS. AT THIS TIME...FORECASTING
TIMING AND LOCATIONS OF HEAVIEST AMOUNTS OF PRECIP ARE VERY
DIFFICULT...AS LARGER SCALE FORCING IS RELATIVELY WEAK.
HOWEVER...FORECAST SOUNDINGS INDICATE RATHER LARGE CAPE VALUES
ACROSS THE SOUTHERN HALF OF THE CWA SATURDAY AFTERNOON...EXCEEDING
3500 J/KG. WHEN COMBINED WITH SLOW STORM MOTIONS ACROSS CENTRAL
AND EASTERN CWA...LOCALLY HEAVY RAINFALL IS A POSSIBILITY SATURDAY
INTO SATURDAY NIGHT. A FEW STRONG STORMS POSSIBLE OUT WEST ALONG
THE RIO GRANDE WHERE BETTER DEEP LAYER SHEAR IS FORECAST. OVERALL
RAINFALL AMOUNTS OF AROUND 1 INCH ARE POSSIBLE...WITH ISOLATED
AMOUNTS OF 2-3 INCHES. GIVEN THE SATURATED CONDITIONS ACROSS THE
AREA...A QUICK 1-3 INCHES WILL CAUSE FLASH FLOODING ISSUES IN
SEVERAL AREAS. OUT OF AN ABUNDANCE OF CAUTION...HAVE ELECTED TO
ISSUE A FLASH FLOOD WATCH FOR SATURDAY AND SATURDAY NIGHT.
LONG TERM (SUNDAY THROUGH FRIDAY)...UPPER LEVEL TROUGH TO THE
WEST DEEPENS SUNDAY INTO MONDAY ACROSS AR AND LA. BETTER MOISTURE
ON SUNDAY REMAINS POOLED ACROSS THE SOUTHERN AND WESTERN CWA...
AND FARTHER TO THE SOUTH. CAN NOT RULE OUT SCATTERED SHOWERS AND
STORMS IN THIS AREA SUNDAY...BUT FORCING APPEARS RATHER LIMITED.
FINALLY DRIER CONDITIONS WILL TAKE PLACE ALONG AND WEST OF THE
I-35 CORRIDOR MONDAY-THURSDAY. CAN NOT RULE OUT ISOLATED SHOWERS
AND STORMS MONDAY THROUGH THURSDAY ACROSS THE COASTAL PRAIRIES
CLOSER TO BETTER MOISTURE AND LOWER HEIGHTS WITH THE TROUGH TO
THE EAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 67 82 64 85 66 / 40 20 10 20 -
AUSTIN BERGSTROM INTL AIRPORT 65 81 62 85 63 / 40 30 10 20 -
NEW BRAUNFELS MUNI AIRPORT 66 83 64 86 66 / 50 30 10 20 -
BURNET MUNI AIRPORT 64 80 62 83 65 / 40 20 10 10 0
DEL RIO INTL AIRPORT 67 86 68 88 69 / 40 30 10 10 -
GEORGETOWN MUNI AIRPORT 65 81 62 84 64 / 40 20 10 20 0
HONDO MUNI AIRPORT 66 83 65 86 66 / 40 40 10 10 -
SAN MARCOS MUNI AIRPORT 66 81 64 84 65 / 50 30 10 20 -
LA GRANGE - FAYETTE REGIONAL 68 82 65 85 66 / 50 40 10 20 10
SAN ANTONIO INTL AIRPORT 68 83 66 85 67 / 50 30 10 20 -
STINSON MUNI AIRPORT 68 83 66 86 67 / 50 40 10 20 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH SUNDAY MORNING
FOR THE FOLLOWING COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...
BLANCO...BURNET...CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...
FAYETTE...FRIO...GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...
KENDALL...KERR...KINNEY...LAVACA...LEE...LLANO...MAVERICK...
MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...WILLIAMSON...WILSON...
ZAVALA.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...ALLEN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
308 AM EDT SAT MAY 30 2015
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL MAINTAIN A VERY WARM AND HUMID AIRMASS
ACROSS THE REGION TODAY INTO SUNDAY. A COLD FRONT WILL APPROACH
FROM THE NORTHWEST LATE IN THE WEEKEND...BEFORE PUSHING SOUTH OF
THE AREA BY MONDAY...RESULTING IN MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS LATER SUNDAY INTO MONDAY AFTERNOON. COOLER WEATHER
UNDER HIGH PRESSURE WILL BUILD IN BY THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 222 AM EDT SATURDAY...
ISOLATED SHOWERS HAVE FINALLY ALL BUT FADED ACROSS THE REGION EARLY
THIS MORNING LEAVING MORE PATCHY FOG AND LOW/MID CLOUDS TO INIT.
HOWEVER AGAIN EXPECTING THIS MOISTURE TO QUICKLY BURN OFF THIS MORNING
LEADING TO ANOTHER RATHER HOT AND HUMID AFTERNOON AS UPPER HEIGHTS
ACTUALLY RISE JUST A BIT FROM THE EAST DURING THE DAY. THIS SHOULD
ALLOW AN AREA OF WEAK SUBSIDENCE THAT WAS TO THE SE ON FRIDAY TO PUSH
NORTH/NW AND PUT MORE OF A LID ON CONVECTION GIVEN FORECAST DRYING
ALOFT OFF SOUNDINGS. LATEST GUIDANCE ALSO SHOWING A DROP IN PWATS THIS
AFTERNOON WITH MORE OF A SOUTHERLY TRAJECTORY DEVELOPING AHEAD OF THE
NEXT 5H TROUGH TO THE WEST. APPEARS BEST WEAK CONVERGENCE TO TAKE PLACE
OVER THE NW WHERE SLIGHTLY BETTER RESIDUAL MOISTURE UNDER A LEFTOVER
WEAKNESS ALOFT MAY ACT TO ENHANCE LIFT A BIT MORE TO PRODUCE A
SCATTERING OF CONVECTION. THIS IN LINE WITH MOST SOLUTIONS AND ESPCLY
THE LATEST NCAR ENSEMBLE AND HRRR BUT STILL NO MORE THAN CHANCE POPS AT
BEST. ELSEWHERE CANT TOTALLY RULE OUT AT LEAST ISOLATED SHRA/TSRA PER
HEATING...DECENT INSTABILITY...AND HIGH 85H THETA-E WITH BEST CHANCES
MOUNTAINS WHERE AIDED BY OROGRAPHICS ESPCLY BLUE RIDGE.
SHOULD BE ONE OF THE WARMEST DAYS SO FAR THIS SEASON GIVEN A WARM START
AND LESS EXPECTED CLOUDS/TSRA THIS AFTERNOON. AGAIN APPEARS MOS A BIT
COOL AS SEEN OVER THE PAST COUPLE OF DAYS AS THICKNESS SUGGESTS HIGHS
CLOSE TO 90 SE...WITH LOW/MID 80S ELSEWHERE OUTSIDE OF THE HIGHEST
ELEVATIONS.
ANY EVENING CONVECTION MAY LINGER ESPCLY MOUNTAINS AN HOUR OR TWO AFTER
SUNSET BEFORE LOSS OF HEATING AND LACK OF FORCING CAUSE SHOWERS TO FADE
SO WILL KEEP SOME LOW POPS GOING THIS EVENING MAINLY FAR WEST. UPSTREAM
PRE-FRONTAL SHRA/TSRA WILL THEN BE THE MAIN CONCERN OVERNIGHT BUT
APPEARS MUCH OF THIS TOO FAR WEST TO REACH THE REGION BY DAYBREAK
SUNDAY. HOWEVER RETURN OF DEEPER MOISTURE AHEAD OF THE TROUGH/FRONT AS
SEEN IN MODEL PWATS LATE SUPPORTS INCLUDING SOME ISOLATED TO LOW CHANCE
POPS MAINLY WESTERN THIRD LATE. OTHERWISE MAINLY PC WITH ADDED PATCHY
FOG BY MORNING. TEMPS TO REMAIN ON THE WARM/MUGGY SIDE WITH MOST SPOTS
ONLY FALLING INTO THE 60-66 RANGE.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 245 AM EDT SATURDAY
THE MEDIUM RANGE MODELS ARE ALL IN CONSENSUS THAT A SFC COLD FRONT..
ASSOCIATED WITH AN UPPER TROUGH MOVING THROUGH THE EASTERN GREAT
LAKES INTO NEW ENGLAND...MOVES THROUGH OUR FORECAST AREA MONDAY.
HOWEVER...THE MORE NOTICEABLE DRIER AIR AND COOLER TEMPS ARRIVE
MONDAY NIGHT/EARLY TUESDAY ONCE SOUTHERN STREAM ENERGY AND
ASSOCIATED SFC WAVE LIFT EAST.
THE FORECAST AREA WILL REMAIN FIRMLY ENTRENCHED IN THE WARM SECTOR
SUNDAY. WHILE INSTABILITY WILL INCREASE AS HIGHER PWAT AIR
RETURNS...BEST SHEAR AND UPPER LEVEL DYNAMICS REMAIN NORTH AND WEST
OF THE FORECAST AREA THROUGH SUNDAY. WHILE AN ISOLATED SEVERE STORM
IS POSSIBLE...GREATER CONCERN MAY BE WITH LOCALLY HEAVY DOWNPOURS.
WITH THE SLOWER ARRIVAL OF THE FRONT...PUSHED UP TEMPS A COUPLE OF
DEGREES FOR HIGHS...ESPECIALLY IN THE EAST.
KEPT POPS GOING AFTER SUNDOWN SUNDAY WITH FORCING FROM SFC BOUNDARY
MOVING INTO THE AREA. WENT ABOVE GUIDANCE FOR LOWS SUNDAY NIGHT DUE
TO CLOUDS AND SOME MIXING.
PRECIPITATION MAY BE MORE WIDESPREAD MONDAY...ESPECIALLY IN THE
SOUTHERN HALF OF THE FORECAST AREA...AS SFC BOUNDARY SLOWS SOMEWHERE
IN THE EASTERN PORTION OF THE FORECAST AREA DUE TO A SFC WAVE FROM
SOUTHERN STREAM ENERGY DEVELOPING IN NC. EXPECT MORE CLOUD COVER AND
SLIGHTLY COOLER TEMPS ON MONDAY...AS A RESULT...LOWER INSTABILITY.
THE EXCEPTION WOULD BE IN ADVANCE OF THE FRONT...IN THE FAR EASTERN
PORTION OF THE FORECAST AREA WHERE AN ISOLATED SEVERE STORM CANNOT
BE RULED OUT.
DRIER/COOLER AIR FINALLY SURGES INTO THE FORECAST AREA MONDAY NIGHT
AND TUESDAY. LEANED TOWARD THE COOLER GUIDANCE VALUES DURING THIS
PERIOD. WHILE THE SFC BOUNDARY PUSHES SOUTH OF THE FORECAST AREA BY
TUESDAY...850MB THETA-E AXIS LINGERS IN NC AND SOUTHERN VA AND WEAK
OVERRUNNING WILL KEEP THE THREAT FOR SHOWERS FOR THIS AREA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 245 PM EDT FRIDAY...
THE COLD FRONT WILL WASH OUT OVER OR JUST SOUTH OF THE AREA BY
TUESDAY AFTERNOON. AFTER THIS POINT...THE REGION WILL START TO
TRANSITION BACK A SOUTHERLY FLOW PATTERN AS A LOW/TROUGH DEVELOPS
ACROSS THE LOWER MISSISSIPPI RIVER VALLEY...AND HIGH PRESSURE
BECOMES CENTERED AGAIN OFF THE COAST OF THE CAROLINAS. DAYTIME
HEATING ALONG WITH PIECES OF ENERGY EJECTING OFF THE LOWER
MISSISSIPPI VALLEY LOW WILL HELP YIELD INCREASING CHANCE OF SHOWERS
AND STORMS AGAIN BY THURSDAY INTO FRIDAY. TEMPERATURES WILL ALSO
START TO TREND MILDER THURSDAY INTO FRIDAY.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1240 AM EDT SATURDAY...
STILL SEEING ISOLATED SHRA LINGER ALONG THE BLUE RIDGE GIVEN
LEFTOVER INSTABILITY BUT EXPECTING MOST RAINFALL TO DISSIPATE
OVER THE NEXT COUPLE OF HOURS WITH COOLING OVERNIGHT. MAY NEED TO
INCLUDE A VCSH MENTION PENDING LOCATION OF SHRA AT RELEASE OTRW
LEAVING OUT MENTION OVERNIGHT.
OTHERWISE...PREVIOUS FORECAST THINKING CONCERNING THE DEVELOPMENT
OF MVFR OR IFR FOG LATER TONIGHT IN AREAS THAT RECEIVED RAIN
EARLIER TODAY STILL SEEMS REASONABLE...AND THIS SUPPORTED BY
LATEST LAMP GUIDANCE. KLWB...KLYH...AND KBCB HAVE THE GREATEST
POTENTIAL FOR DEVELOPMENT OF LATE NIGHT VISIBILITY RESTRICTIONS...LESS
SO AT KDAN...KBLF...AND KROA. HOWEVER STILL QUITE UNCERTAIN AS TO
HOW LOW VSBYS WILL GO GIVEN PATCHY NATURE TO FOG AND LINGERING
STRATO-CU/AC THAT COULD HINDER FOG DEVELOPMENT SIMILAR TO LAST
NIGHT. FOR NOW ADDED IN BRIEF TEMPO GROUPS FOR LOWER VSBYS AT
KBCB/KLWB WHERE COULD SEE A PERIOD OF LIFR AROUND DAYBREAK.
SIMILAR TO FRIDAY MORNING...EXPECT MOST LATE NIGHT FOG TO
DISSIPATE BY 13Z/9AM...TO BE QUICKLY FOLLOWED BY DEVELOPMENT OF
CUMULUS WITH ONSET OF SURFACE HEATING. HOWEVER...UNLIKE
FRIDAY...EXPECT SOME SUBSIDENCE NUDGING IN FROM THE SOUTHEAST SUCH
THAT ANY DIURNAL REDEVELOPMENT OF SHOWERS/STORMS BY LATE
MORNING/EARLY AFTERNOON EXPECTED TO BE LESS IN OVERALL COVERAGE
AND MAINLY CONFINED TO SOUTHEAST WEST VIRGINIA. THEREFORE...VCTS
COMMENT KEPT AT KBLF AND KLWB TERMINAL FORECAST POINTS AT
17Z/1PM...BUT NOT AT THE REMAINING AVIATION FORECAST POINTS.
EXTENDED DISCUSSION...
ON SUNDAY...A MOIST UNSTABLE AIR MASS WILL REMAIN IN PLACE ACROSS
THE REGION WITH ONLY WEAK FORCING. THIS WILL RESULT IN MAINLY SLOW
MOVING DIURNALLY DRIVEN DEEP CONVECTION DURING THE AFTERNOON AND
EVENING HOURS FOLLOWED BY STABLE CONDITIONS AND PATCHY MVFR FOG AT
NIGHT.
A FRONTAL SYSTEM WILL APPROACH FROM THE NORTH SUNDAY NIGHT. THIS
BOUNDARY SHOULD FINALLY SINK SOUTH INTO THE REGION BY MONDAY RESULTING
IN WIDESPREAD CONVECTION...WITH ADDITIONAL ROUNDS OF SHRA/TSRA
INTO AT LEAST MONDAY NIGHT BEFORE THE BOUNDARY SINKS TO THE
SOUTH. THIS SHOULD MAKE FOR MORE FREQUENT PERIODS OF SUB-VFR FROM
SUNDAY NIGHT INTO TUESDAY MORNING WITH LOWER CIGS/VSBY REDUCTIONS
DUE TO SHOWERS/STORMS DURING THE DAY...AND IN FOG OVERNIGHT INTO
THE EARLY MORNING HOURS EACH DAY. LOWER MVFR/IFR CIGS ARE LIKELY
BEHIND THE FRONT ON TUESDAY AND WEDNESDAY WITH EASTERLY FLOW AND
WEDGING IN PLACE RESULTING IN MVFR CEILINGS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...JH
SHORT TERM...PH
LONG TERM...DS
AVIATION...AMS/JH/WERT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1148 PM CDT FRI MAY 29 2015
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 207 PM CDT FRI MAY 29 2015
SURFACE MAP THIS AFTERNOON HAS A COLD FRONT DRAPED FROM WESTERN
LAKE SUPERIOR THROUGH SOUTH CENTRAL MN...INTO EASTERN NEB. RADAR
MOSAIC SHOWING WIDELY SCATTERED SHOWER/THUNDERSTORMS OUT AHEAD OF THE
FRONT ACROSS THE ARX FORECAST AREA. MEANWHILE...FOCUS OF
SHOWERS/STORMS TIED MORE TOWARD POST FRONTAL/MID-LEVEL TROUGH PV-
ADVECTION/850-700MB FRONTOGENESIS FORCING ACROSS NORTHWEST
WI/SOUTHERN MN/EASTERN SD. OTHERWISE...MOSTLY CLOUDY SKIES IN PLACE
WITH TEMPERATURES RANGING FROM THE UPPER 60S ACROSS NORTH CENTRAL
WI...TO THE MIDDLE AND UPPER 70S ELSEWHERE.
LOOK FOR THE COLD FRONTAL BOUNDARY TO SLIDE SOUTHEAST ACROSS THE
AREA...EXITING EAST AFTER MIDNIGHT. RAP MODEL SHOWS FAIRLY STRONG
850-700MB FRONTOGENESIS/700-300MB PV-ADVECTION...ALONG WITH
INCREASING 700-500MB LAPSE RATES GOING INTO THIS EVENING. THIS WILL
CONTINUE TO FUEL SHOWER AND THUNDERSTORMS...WITH GRADUAL DIMINISHING
TREND FROM WEST TO EAST AFTER MIDNIGHT. COULD BE SOME HEAVIER RAIN
RATES WITH THE SHOWERS/STORMS GIVEN THE FORCING AND PRECIPITABLE
WATER VALUES IN THE 1.5-1.8 INCH RANGE.
AFTER A FEW LINGERING SHOWERS/ISOLATED THUNDERSTORMS SATURDAY
MORNING...LOOK FOR DRYING/COOLER CONDITIONS THROUGH THE REMAINDER OF
THE DAY AS CANADIAN HIGH PRESSURE BUILDS IN. HIGHS SATURDAY ARE ONLY
EXPECTED TO TOP OFF IN THE LOWER/MIDDLE 60S.
HIGH PRESSURE WILL SETTLE OVERHEAD SATURDAY NIGHT FOR MOSTLY
CLEAR/CALM CONDITIONS. THIS WILL SET UP GOOD RADIATIONAL COOLING WITH
PATCHY FROST POSSIBLE ACROSS THE SAND/BOG COUNTRY AREAS OF CENTRAL
WI. PLAN ON LOWS IN THE MIDDLE 30S ACROSS THAT AREA...AND
LOWER/MIDDLE 40S ELSEWHERE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 207 PM CDT FRI MAY 29 2015
COOL CANADIAN HIGH PRESSURE REMAINS IN CONTROL THROUGH MONDAY. LOOK
FOR HIGH TEMPERATURES ON SUNDAY IN THE LOWER/MIDDLE 60S...WARMING
SLIGHTLY INTO THE 65-70 DEGREE RANGE MONDAY.
LOW PRESSURE MOVING INTO THE PLAINS WILL PUSH A WARM FRONT
TOWARD/THROUGH THE AREA TUESDAY THROUGH WEDNESDAY NIGHT FOR A
CHANCE OF SHOWERS AND THUNDERSTORMS. HIGHS TUESDAY LOOK TO BE IN THE
70-75 DEGREE RANGE...WARMING INTO THE UPPER 70S/LOWER 80S ON
THURSDAY. SHOWER/THUNDER CHANCES CONTINUE INTO FRIDAY AS A MID-LEVEL
TROUGH/SURFACE COLD FRONT MOVES THROUGH THE REGION. HIGHS FRIDAY ARE
EXPECTED TO TOP OFF AGAIN IN THE UPPER 70S/LOWER 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1147 PM CDT FRI MAY 29 2015
STRONG 900 TO 800 MB FRONTOGENESIS WILL CONTINUE TO PRODUCE
SHOWERS IN THE WAKE OF THE COLD FRONT AT KRST THROUGH 30.08Z AND
AT KLSE THROUGH 30.10Z. SOUNDINGS CONTINUE TO SHOW THAT IFR/MVFR
CEILINGS WILL CONTINUE THROUGH THE SATURDAY MORNING AT BOTH TAF
SITES AND THEN SKIES WILL BECOME VFR AS SUBSIDENCE AND DRIER AIR
MOVE INTO THE REGION.
BOTH TAF SITES THROUGH THE AFTERNOON WILL SEE SUSTAINED NORTH
WINDS OF 10 TO 20 KNOTS WITH GUSTS RANGING FROM 20 TO 25 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1023 AM EDT SAT MAY 30 2015
.SYNOPSIS...
DRY WEATHER WILL CONTINUE FOR TODAY THANKS TO AN AREA OF HIGH
PRESSURE. A COLD FRONT WILL SLOWLY MOVE ACROSS THE REGION
SUNDAY...THEN STALL SOUTH OF NEW ENGLAND EARLY NEXT WEEK. THIS
WILL BRING A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS
SUNDAY...AND A PERIOD OF RAIN EARLY NEXT WEEK. HIGH PRESSURE
BRINGS DRY WEATHER FOR THE LATTER PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1015 AM UPDATE...
FOG HAS MOSTLY LIFTED WITH EXCEPTION OF THE S COASTAL WATERS AND
PORTIONS OF RI COAST...WHILE STRATUS IS SLOWLY ERODING ACROSS
NE CT AND RI. STRATUS AND PATCHY FOG WILL LIFT BY
MIDDAY...OTHERWISE EXPECT PT-MOSUNNY SKIES.
THE MAIN FORECAST QUESTION IS EXTENT OF ANY CONVECTION THIS
AFTERNOON. MID LEVEL RIDGE REMAINS JUST OFF THE COAST WHICH WILL
SLOW COLD FRONT AS IT MOVES THROUGH THE GT LAKES AND STABILIZE E
HALF NEW ENG. MAIN FOCUS FOR CONVECTION WILL BE ACROSS UPSTATE NY
AND VT IN HIGHER THETA-E AXIS AND BETTER INSTABILITY. MODELS DO
GENERATE MARGINAL INSTABILITY IN W NEW ENG WITH CAPES 500-1000
J/KG BUT 0-6KM SHEAR IS QUITE WEAK. HRRR SHOWS A FEW ISOLD SHOWERS
DEVELOPING IN THE WEST THIS AFTERNOON AND WILL KEEP SLIGHT CHC
POPS W MA FOR A BRIEF SHOWER/TSTM THIS AFTERNOON...BUT MOST OF THE
AREA WILL REMAIN DRY.
HIGH TEMPS WILL REACH THE LOW TO MID 80S ACROSS MUCH OF THE
REGION AWAY FROM THE S COAST WITH WARMEST TEMPS IN THE UPPER 80S
LIKELY ACROSS INTERIOR NE MA. OTHERWISE 70S NEAR THE S COAST DUE
TO GUSTY SW FLOW. IN FACT...SOUNDINGS SUPPORT WIND GUSTS TO 25-30
MPH TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
NOTICED GUIDANCE CONTINUES TO SLOW DOWN THE FRONTAL PASSAGE...SO
HAVE ADJUSTED THE FORECAST TO ACCOUNT FOR THIS TREND.
THE COLD FRONT WILL BEGIN TO APPROACH THE REGION
TONIGHT...BRINGING SOME MUCH NEED RAINFALL TO THE REGION. AS THE
FRONT APPROACHES GUIDANCE INDICATES THAT SHOWALTERS WILL BE BELOW
0 WITH K VALUES ABOVE 30C. THEREFORE CANNOT RULE OUT SOME
EMBEDDED THUNDER OVERNIGHT. AREA THAT WILL SEE THE HIGHER RAINFALL
AMOUNTS WILL BE NORTH OF THE PIKE...ESP NORTH OF ROUTE 2.
SINCE THE FRONT WILL STILL BE NORTHWEST OF THE REGION...ANTICIPATE
ANOTHER ROUND OF FOG TO DEVELOP ALONG THE SOUTH COAST/CAPE AND
ISLANDS AS MOISTURE POOLS ALONG THE FRONT. LOW CONFIDENCE IF IT WILL
BE DENSE OR NOT.
TOMORROW...
TIMING OF THE COLD FRONT IS STILL IN QUESTION AS LATEST GUIDANCE
TREND IS TO SLOW DOWN THE FRONT. REGARDLESS BELIEVE THAT THE FRONT
WILL CROSS SOUTHERN NEW ENGLAND ON SUNDAY BRINGING SOME MUCH NEEDED
RAIN. GUIDANCE STILL SHOWS ELEVATED THUNDER PARAMETERS...SO WILL
CONTINUE TO MENTION THUNDER IN THE FORECAST...BUT STRONG TO SEVERE
STORMS ARE NOT EXPECTED.
BOTH THE NAM AND GFS INDICATE GOOD BOUNDARY LAYER MOISTURE ALONG THE
FRONT AS IS BEGINS TO STALL OVER THE REGION. WITH PWAT VALUES AROUND
1.6 INCHES AND THE FRONT BECOMING ALIGNED WITH THE UPPER FLOW
ALOFT...COULD SEE THE POTENTIAL FOR HEAVY RAIN AND FLOODING DUE TO A
SLOW STORM MOTION. BECAUSE OF THE UNCERTAINTY ON WHERE THE FRONT
WILL STALL...HELD OFF ON ISSUING ANY SORT OF FLOOD WATCH AT THIS
TIME. RIGHT NOW BELIEVE THAT LOCATIONS ALONG AND NORTH OF THE MASS
PIKE WILL SEE THE HIGHER PRECIP AMOUNTS ON SUNDAY. PERHAPS IT WILL
PUSH WORCESTER OUT OF THE TOP 5 DRIEST MAYS ON RECORD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
OVERVIEW AND MODEL PREFERENCES...
QUITE A CHANGE IN THE SOLUTIONS OF THE 30/00Z GUIDANCE FROM THOSE
JUST 24 HOURS AGO. THE TREND HAS BEEN FOR A SIGNIFICANT SLOW-DOWN
OF A COLD FRONTAL PASSAGE SUNDAY NIGHT INTO MONDAY. SOME MINOR
DIFFERENCES REMAIN...BUT IT WAS NOTEWORTHY THAT JUST ABOUT ALL OF
THE GUIDANCE LATCHED ON TO THIS SLOWER TIMING. MODELS HAVE ALSO
COME INTO BETTER AGREEMENT WITH THEIR HANDLING OF A MID LEVEL
TROUGH EARLY NEXT WEEK. MORE RIDGING RETURNS FOR LATE NEXT WEEK.
FAVORED A MODEL CONSENSUS SOLUTION FOR THIS FORECAST UPDATE TO
SMOOTH OVER THE MINOR DIFFERENCES...WHERE POSSIBLE.
THE DAILIES...
SUNDAY NIGHT THROUGH TUESDAY...DIFFERENCES AMONG THE MODELS ON
TIMING A FRONTAL PASSAGE...BUT ALL MOVE IT TO THE SOUTH COAST OF
NEW ENGLAND BY SUNDAY EVENING. THIS FRONT THEN SHOULD ALIGN WITH
THE UPPER FLOW AND STALL. A SHORTWAVE MOVING THROUGH THE GREAT
LAKES IS FORECAST TO GENERATE A WAVE ALONG THIS FRONT...WHICH
CROSSES THE APPALACHIANS MONDAY AND PASSES SOUTH OF NEW ENGLAND
TUESDAY. THIS LOW PRESSURE...ALONG WITH HIGH PRESSURE OVER EASTERN
CANADA...SHOULD BRING A COOL NORTHEAST FLOW TO THE REGION MONDAY
AND TUESDAY. MEANWHILE A SOUTHWEST FLOW CONTINUES ALOFT...
PROVIDING BOTH LIFT AND MOISTURE. WE WILL MAINTAIN LIKELY POPS
MONDAY...DIMINISHING TO CHANCE POPS BY LATE TUESDAY AS THIS LOW
MOVES EAST.
WEDNESDAY THROUGH FRIDAY...HIGH PRESSURE BUILDS AT THE SURFACE
AND ALOFT...BRINGING DRY WEATHER TO SOUTHERN NEW ENGLAND. LIGHT
WINDS WILL FAVOR LOCAL SEABREEZES DURING THE DAYLIGHT HOURS.
HOWEVER...THE INCREASED SUNSHINE WILL FAVOR A GRADUAL WARM-UP
ACROSS THE INTERIOR EACH DAY.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TODAY...MODERATE CONFIDENCE. PATCHY IFR STRATUS AND FOG NEAR THE
S COAST ERODING BY MIDDAY...OTHERWISE VFR. DRY WEATHER
EXPECTED...ALTHOUGH THERE IS A LOW RISK OF A SPOT SHOWER/
THUNDERSTORM ACROSS WESTERN MA THIS AFTERNOON/EARLY EVENING.
TONIGHT INTO SUNDAY...MODERATE CONFIDENCE. VFR TO START WITH
CONDITIONS DETERIORATING BY LATE TONIGHT INTO SUNDAY DUE TO
WIDESPREAD -SHRA/-TSRA. FOG AND STRATUS MAY FILL BACK IN ALONG THE
SOUTH COAST OVERNIGHT TONIGHT. OTHERWISE COULD SEE SOME LLWS
ACROSS THE SOUTHERN SITES ON SUNDAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...MODERATE CONFIDENCE.
MONDAY THROUGH TUESDAY...MVFR/IFR CIGS AND VSBYS...MOST LIKELY
OVER THE COASTAL PLAIN AND ALONG THE EASTERN SLOPES OF THE
WORCESTER HILLS. SHOWERS POSSIBLE THROUGH BOTH DAYS.
WEDNESDAY...VFR WITH A LIGHT NORTH-NORTHWEST WIND. LOCAL
SEABREEZES POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH SUNDAY/...
TODAY...MODERATE TO HIGH CONFIDENCE. EXCELLENT MIXING OVER THE
LAND WILL GENERATE NEAR SHORE SMALL CRAFT WIND GUSTS OF 25 TO 30
KNOTS THIS AFTERNOON. IN ADDITION...SOUTHEAST SWELL WILL GENERATE
5 FOOT SEAS ACROSS THE OUTER-WATERS. THEREFORE...SMALL CRAFT
HEADLINES POSTED FOR ALL WATERS. AREAS OF FOG SHOULD IMPROVE
SOMEWHAT BY AFTERNOON.
TONIGHT...MODERATE TO HIGH CONFIDENCE. NEAR SHORE SMALL CRAFT
WIND GUSTS SHOULD DIMINISH BY THE EVENING. HOWEVER...5 FOOT SWELL
WILL CONTINUE ACROSS THE OUTER-WATERS. AREAS OF DENSE FOG
POSSIBLE TONIGHT.
SUNDAY...MODERATE CONFIDENCE. MAY NEED TO EXTEND SCA FOR CAA
BEHIND A PASSING COLD FRONT FROM THE NORTH. OTHERWISE EXPECT
SHOWERS WITH EMBEDDED THUNDER COULD OCCUR AHEAD OF THE FRONT DURING
THE AFTERNOON HOURS.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...MODERATE CONFIDENCE.
MONDAY-TUESDAY...SMALL CRAFT ADVISORY MAY BE NEEDED...ESPECIALLY
ON THE EASTERN COASTAL WATERS. NORTHEAST WINDS GUSTING UP TO 20
KT...AND PERHAPS A FEW GUSTS TO 25 KNOTS...EACH DAY. SEAS 5 TO 8
FEET ON THE EASTERN MA WATERS...AND 3 TO 5 FEET ON THE SOUTHERN
WATERS.
WEDNESDAY...A SMALL CRAFT ADVISORY MAY BE NEEDED...MAINLY ON THE
EASTERN WATERS. DIMINISHING NORTHEAST TO NORTH WINDS. SEAS OF 5 FEET
MAY LINGER ON THE EASTERN WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
ANZ230>237-251.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 3 PM EDT
SUNDAY FOR ANZ250-254>256.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...KJC/DUNTEN
SHORT TERM...DUNTEN
LONG TERM...BELK
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
AREA FORECAST DISCUSSION
NWS ALBANY NY
1006 AM EDT SAT MAY 30 2015
.SYNOPSIS...
A COLD FRONT...WORKING ACROSS THE WESTERN GREAT LAKES...WILL
APPROACH OUR AREA BY TONIGHT. SCATTERED THUNDERSTORMS COULD BREAK
OUT AHEAD OF THIS FEATURE THIS AFTERNOON AND EVENING. THEN...AS THE
COLD FRONT REACHES OUR REGION...IT WILL STALL JUST TO THE SOUTH OF
ALBANY. WAVES OF LOW PRESSURE WILL RIDE ALONG THIS BOUNDARY LATE
TONIGHT THROUGH MONDAY WHICH COULD BRING A SOAKING RAINFALL TO THE
REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 930 AM EDT...A REVIEW OF THE 12Z SOUNDINGS REVEAL PWATS ARE
CLIMBING ACROSS WESTERN NY/PA WITH THE BEST UPPER DYNAMICS
TRANSVERSING WELL TO THE NORTH AND WEST OF THE CWFA. H2O VAPOR
LOOP REVEALS THE APPROACHING SHORT WAVE TROUGH TO THE NORTH OF THE
GREAT LAKES REGION WITH A FEW SUBTLE EMBEDDED WAVES ON THE
SOUTHERN PERIPHERY OF THIS TROUGH THROUGH THE OHIO VALLEY AND
LOWER GREAT LAKES. MODIFYING THE SOUNDINGS UPSTREAM YIELDS SBCAPES
AROUND 1000 J/KG WITH WEAK MID LEVEL LAPSE RATES TO CONTINUE THE
PREVIOUS SPC OUTLOOK OF `MARGINAL` 5%. LATEST HRRR SUGGESTS
CONVECTION WILL DEVELOP CLOSE TO THE NOON HOUR THEN EXPAND IN
COVERAGE ACROSS MOST OF THE REGION DURING THE AFTERNOON HOURS. THE
MAIN CONCERN WILL BE HEAVY RAINFALL AS THIS UPSTREAM FRONT SLOWS
DOWN ITS FORWARD PROPAGATION AS MOISTURE CONVERGENCE AND HIGHER
PWATS CONVERGE ACROSS THE NORTHWEST 1/3RD OF THE CWFA. SO FOR THIS
ESTF...MODIFIED THE HOURLY GRIDS TO ACCOUNT FOR
OBSERVATIONS...ADDED ENHANCED WORDING FOR THUNDERSTORMS WITH
RESPECT TO SOME GUST WINDS AND HEAVY RAIN AND PER THE
SOUNDINGS...OUR AFTERNOON TEMPERATURES LOOK ON TRACK AT THIS TIME.
PREV DISC...
AS THE ATMOSPHERE HEATS UP...IT WILL BECOME UNSTABLE. MID LEVEL
LAPSE RATES LOOK MODEST (AROUND 5.5 C/KM). HOWEVER INSTABILITY WILL
RAMP UP TO ABOUT 1500 SBCAPES DURING THE AFTERNOON. WE EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS TO CROP UP...ESPECIALLY NORTH
AND WEST OF THE CAPITAL REGION. THE STORM PREDICTION CENTER HAS OUR
MOST OF OUR REGION IN MARGINAL WHICH MEANS SOME STRONG TO LOCALLY
SEVERE STORMS COULD HAPPEN LATER TODAY DUE TO INCREASING WINDS
ALOFT. WE WILL INTRODUCE ENHANCED WORDING FOR THUNDERSTORMS POSSIBLY
CONTAINING GUSTY WINDS. SOME HAIL IS POSSIBLE...BUT RIGHT NOW...WIND
APPEARS THE BIGGER THREAT.
THIS WILL BE THE LAST DAY OF THIS CURRENT WARM SPELL...WITH HIGHS IN
THE LOWER TO MID 80S IN THE VALLEYS...75-80 HIGHER TERRAIN.
THE WIND WILL BE OUT OF THE SOUTH AND BY AFTERNOON...MOST PLACES
WILL AVERAGE AROUND 10 MPH...WITH SOME GUSTS TO 20 MPH OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE AFOREMENTIONED COLD FRONT BE ACROSS THE SAINT LAWRENCE THIS
EVENING...AND WORK SOUTHWARD TOWARD THE CAPITAL REGION OVERNIGHT.
WITH AN INCREASING LOW LEVEL JET AND EVENTUALLY ANTICYLONICALLY
CURVED UPPER LEVEL JET ENTRANCE REGION...COMBINING WITH PWATS WELL
OVER 1.5 INCHES...THIS SET UP IS LOOKING MORE AND MORE LIKE A GOOD
BET TO BRING A SOAKING RAINFALL TO THE REGION THROUGH MONDAY.
NOW IT WILL PROBABLY NOT RAIN THE WHOLE TIME FRAME. INITIALLY IT
LOOKS LIKE A ROUND OF SHOWERS AND PERHAPS A FEW MORE EMBEDDED
THUNDERSTORMS TONIGHT RIGHT ALONG AND BEHIND THE COLD FRONT...AS IT
BECOMES PARALLEL TO THE SOUTHWEST FLOW ALOFT.
THERE MIGHT BE A REDUCTION IN SHOWERS ON SUNDAY AS ONE WAVE PASSES
BY. HOWEVER...IT LOOKS AS IF A STRONG WAVE OF LOW PRESSURE SHOULD
FORM BY LATE SUNDAY...TRACKING FROM THE SOUTHERN OHIO
VALLEY...WESTERN PA AND UP ACROSS NY STATE. THIS WILL BE THE BEST
SHOT OF STEADY RAIN...POSSIBLY MODERATE TO EVEN HEAVY AT TIMES
SUNDAY NIGHT INTO MONDAY.
IT WILL TURN NOTICEABLY CHILLIER BEHIND THE FRONT. THE FIRST AREAS
TO FEEL THIS WILL BE NORTH OF THE MOHAWK VALLEY SATURDAY NIGHT WHERE
TEMPERATURES WILL DROP INTO THE 50S...WHILE MUGGIER 60S WILL BE
COMMON FROM THE CAPITAL REGION SOUTHWARD.
SUNDAY...HIGH TEMPERATURES MIGHT HOLD IN THE MID OR UPPER 50S WELL
NORTH OF ALBANY...LOWER 60S IN THE CAPITAL REGION...STILL WARMER
SOUTH WHERE THE FRONT WILL LIKELY TO CLEAR UNTIL LATE IN THE DAY.
TEMPERATURES NEAR POUGHKEEPSIE WILL LIKELY POP INTO THE 70S.
MUCH COOLER EVERYWHERE ON MONDAY AS OUR REGION LOOKS TO REMAIN IN
THE COOL SECTORS...GENERALLY AROUND 70 SOUTH...LOWER TO MID 60S IN
AND AROUND THE CAPITAL REGION...60 OR LOWER NORTH. THESE VALUES ARE
MUCH CLOSER FOR THE 1ST DAY OF MAY AS OPPOSED TO THE FIRST DAY OF
JUNE.
TO THE SOUTH OF CAPITAL REGION...THERE COULD BE ENOUGH AFTERNOON
INSTABILITY FOR SOME THUNDERSTORM ACTIVITY ON SUNDAY AFTERNOON AS
THE FRONT CONTINUES TO WORK THROUGH.
CHECKING ANOMALIES...THE PWATS UP TO 1.75 INCHES CONTINUE TO BE 2-3
STANDARD DEVIATION ABOVE NORMAL. THE H850 SOUTHERLY COMPONENT REACHED
THE 1-2 STANDARD DEVIATION RANGE...AND THE 250 WIND (EAST WEST)
COMPONENT NEVER STRAYS THAT MUCH FROM NORMAL. THE 03Z SREFS AVERAGE
ABOUT 1.5 INCHES FOR ALBANY...WITH HIGHEST AMOUNTS AROUND 3.5
INCHES. THE 00Z GEFS WERE CONSIDERABLY HIGHER...AVERAGING AROUND 3
INCHES WITH MEMBERS AS HIGH AS 4 INCHES AND THE LOWEST VALUES AROUND
1.3 INCHES.
FOR NOW OUR QPF WAS BLEND OF THE GEFS/SREF. MORE ABOUT THE QPF CAN
BE FOUND IN OUR HYDROLOGY SECTION.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
EVEN THOUGH THE SURFACE WAVE AND HEAVIER RAINFALL WILL HAVE ALREADY
CLEARED THE REGION BY SUNRISE TUESDAY...WE CAN STILL EXPECT SOME
LINGERING SHOWERS TUESDAY DUE TO THE UPPER LOW THAT WILL BE MOVING
EASTWARD ACROSS SOUTHERN QUEBEC. SHOWER ACTIVITY WITH THIS FEATURE
WILL BE SCATTERED AT BEST...AND HAVE FORECAST POPS OF 40 TO 50
PERCENT TUESDAY MORNING...DECREASING TO 30 TO 40 PERCENT DURING THE
AFTERNOON. IT WILL BE PARTLY TO MOSTLY CLOUDY ON TUESDAY WITH HIGHS
IN THE UPPER 50S AND 60S.
TUESDAY NIGHT THROUGH FRIDAY LOOKS DRY AT THIS POINT WITH TEMPS
GRADUALLY RISING THROUGH THE PERIOD. A LARGE RIDGE OF HIGH PRESSURE
WILL BUILD ACROSS THE REGION. LOWS TUESDAY NIGHT WILL BE 40 TO 50.
HIGHS ON WEDNESDAY IN THE UPPER 60S TO LOWER 70S. LOWS WEDNESDAY
NIGHT IN THE UPPER 40S TO MID 50S. HIGHS THURSDAY IN THE 70S TO
LOWER 80S. LOWS THURSDAY NIGHT IN THE 50S. HIGHS FRIDAY IN THE MID
70S TO LOWER 80S.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT WILL BE APPROACHING THE REGION FROM THE WEST TODAY
AND TONIGHT. IT WILL LIKELY MOVE THROUGH KGFL BEFORE THE END OF
THE TAF PERIOD AT 12Z SUNDAY...BUT REMAIN TO THE NORTH AND WEST OF
KALB/KPOU/KPSF.
EXPECT MAINLY VFR CONDITIONS AT THE KGFL/KALB/KPOU/KPSF TAF SITES
THROUGH MOST OF TODAY WITH MAINLY MID/HI CLOUDS AND SCT CUMULUS.
THE EXCEPTION WILL BE EARLY THIS MORNING WHERE A MVFR STRATUS DECK
WAS OVER KPOU AS OF 630 AM. THIS STRATUS DECK SHOULD MIX OUT BY
AROUND 14Z.
SHOWERS WILL BE ADVANCING ACROSS THE REGION LATER TODAY...AND HAVE
PLACED VCSH IN THE TAFS AT KGFL/KALB/KPSF AFTER 21Z...AND INCLUDED
A PROB30 GROUP FOR THUNDERSTORMS WITH IFR/MVFR CONDITIONS BETWEEN
30/21Z- 22Z AND 31/03Z-04Z. AT KPOU THE VCSH STARTS AT 23Z WITH
THE PROB30 GROUP FROM 30/23Z TO 31/05Z. AFTER THE THREAT OF
TSTMS...HAVE FORECAST CIGS/VSBYS LOWERING TO MVFR AT KGFL/KALB/KPSF
BETWEEN 03Z AND 04Z AS A MORE WIDESPREAD AREA OF SHOWERS MOVES IN.
BETWEEN 06Z AND 09Z...VSBYS SHOULD LOWER EVEN FURTHER...WITH CIGS
LOWERING INTO THE IFR RANGE AT KGFL/KALB/KPSF.
SOUTHERLY WINDS WILL BE INCREASING TODAY...REACHING SPEEDS OF 10
TO 15 KTS WITH GUSTS OF 20 TO 25 KTS DURING THE AFTERNOON AND
EARLY EVENING. BY MIDNIGHT WINDS WILL DECREASE TO AROUND 10
KTS...WITH SOME GUSTS OVER 15 KTS AT KALB. AT KGFL...WINDS WILL
SHIFT TO NORTHERLY AROUND 09Z AS THE COLD FRONT MOVES THROUGH.
OUTLOOK...
SUN-MON: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
MON NIGHT-TUE: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
TUE NIGHT-WED: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
MOST AREAS WILL START OFF WITH HIGH RH VALUES TODAY...IN THE 75-90
PERCENT RANGE. RH VALUES WILL ONLY FALL TO AROUND 50 PERCENT THIS
AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON WITH ANY THUNDERSTORMS POSSIBLY CONTAINING GUSTY WINDS.
THE MOST NUMEROUS STORMS SHOULD BE NORTH AND WEST OF THE CAPITAL
REGION...LESS NUMEROUS SOUTH AND EAST OF THE CAPITAL REGION.
THEN...IT LOOKS AS IF A SOAKING RAIN IS LIKELY HAPPEN TONIGHT
THROUGH AT LEAST MONDAY. WHILE IT NOT BE RAINING ALL OF THIS
TIME...THERE IS POTENTIAL FOR MODERATE TO HEAVY RAINFALL AT TIMES.
IT IS ALMOST A CERTAINTY EVERYONE WILL END UP WITH WELL OVER A
QUARTER INCH OF RAINFALL...MOST AREAS LIKELY RECEIVING AROUND TWO
INCHES OF RAINFALL.
DRYING CONDITIONS ARE EXPECTED TUESDAY THROUGH THURSDAY AS THE RAINS
ARE REPLACED BY DRIER AND EVENTUALLY A RETURNS TO WARMER WEATHER.
&&
.HYDROLOGY...
A WIDESPREAD SIGNIFICANT RAINFALL AS COLD FRONT APPROACHES AND
SLOWLY MOVES ACROSS THE REGION AS A WAVE OF LOW PRESSURE MOVES ALONG
THE BOUNDARY. SHOWERS AND THUNDERSTORMS ARE EXPECTED MAINLY THIS
AFTERNOON INTO THE EVENING WELL AHEAD OF THE COLD FRONT. A WAVE OF
LOW PRESSURE WILL FORM ON THE BOUNDARY SLOWING ITS PROGRESS ACROSS
THE REGION AND RESULTING IN SHOWERS ACROSS THE REGION. AT THIS
TIME...A WIDESPREAD 1 TO 3 INCHES OF RAINFALL IS FORECAST THROUGH
MONDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE. HAVE ADDED MENTION TO
OUR HAZARDOUS WEATHER OUTLOOK THAT IF THE THREAT OF HEAVY RAINFALL
BECOMES MORE CERTAIN A FLOOD WATCH MAY BE ISSUED. ON THE OTHER
HAND...THIS WILL LIKELY BE BENEFICIAL RAINFALL SINCE MUCH OF OUR
REGION HAS ONLY SEEN ABOUT HALF ITS NORMAL RAINFALL SO FAR THIS
YEAR.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV/BGM
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
FIRE WEATHER...HWJIV
HYDROLOGY...IAA/HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
628 AM EDT SAT MAY 30 2015
.SYNOPSIS...
A COLD FRONT...WORKING ACROSS THE WESTERN GREAT LAKES...WILL
APPROACH OUR AREA BY TONIGHT. SCATTERED THUNDERSTORMS COULD BREAK
OUT AHEAD OF THIS FEATURE THIS AFTERNOON AND EVENING. THEN...AS THE
COLD FRONT REACHES OUR REGION...IT WILL STALL JUST TO THE SOUTH OF
ALBANY. WAVES OF LOW PRESSURE WILL RIDE ALONG THIS BOUNDARY LATE
TONIGHT THROUGH MONDAY WHICH COULD BRING A SOAKING RAINFALL TO THE
REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 445 AM EDT...RADARS STILL DEPICTED NO ACTIVITY ACROSS OUR
REGION. THE LATEST HRRR CONTINUES TO INSIST THAT SCATTERED TO
NUMEROUS SHOWERS WILL DEVELOP ACROSS THE MOHAWK VALLEY INTO THE
CAPITAL DISTRICT SHORTLY AFTER SUNRISE. THE LATEST RAP INDICATED THE
SAME IDEA...NOT AS AGGRESSIVE. BOTH OF THESE MODELS DID HINT AT SOME
THETA-RIDGING ACROSS THE AREA. MEANWHILE...THE 00Z AND 06Z NAM AND
GFS DID NOT HAVE THIS. AT THIS TIME WE LEANED AGAINST THIS HAPPENING
BUT WILL MONITOR TO SEE IF ANYTHING DOES.
THE NEAREST SHOWER ACTIVITY WAS UP ACROSS THE ST. LAWRENCE VALLEY
AND LAKE ONTARIO...OUT AHEAD OF STRONG COLD FRONT...WORKING INTO THE
WESTERN GREAT LAKES AND WESTERN PORTIONS OF THE OHIO VALLEY. THIS
FRONT WAS HEADING SOUTHEAST ABOUT 30 MPH.
ASSUMING NO SHOWERS DEVELOP IT SHOULD STAY MAINLY DRY THROUGH EARLY
MORNING. A FEW SHOWERS MIGHT WORK INTO THE ADIRONDACKS AND WE DO
HAVE SLIGHT CHANCES FOR THOSE AREAS STARTING BEFORE SUNRISE.
TEMPERATURES VARIED DEPENDING ON HOW MUCH OF A BREEZE TOOK PLACE AS
WELL AS CLOUDS. TEMPERATURES RANGED FROM THE UPPER 60S IN THE
IMMEDIATE CAPITAL REGION DUE TO A SOUTHERLY BREEZE AROUND 10
MPH...WHILE OTHER PLACES WERE CLOSER TO 60...OR EVEN IN THE UPPER
50S DUE TO THIN CLOUDS AND LITTLE OR NO WIND. TEMPERATURES WILL
LIKELY NOT FALL MUCH MORE BEFORE DAWN.
SOME AREAS WILL ACTUALLY ENJOY SOME MORNING SUNSHINE...BEFORE MID
LEVEL CLOUDS THICKEN AND CU DEVELOP. THERE WAS ALSO SOME STRATUS
WORKING INTO THE MID HUDSON VALLEY.
AS THE ATMOSPHERE HEATS UP...IT WILL BECOME UNSTABLE. MID LEVEL
LAPSE RATES LOOK MODEST (AROUND 5.5 C/KM). HOWEVER INSTABILITY WILL
RAMP UP TO ABOUT 1500 SBCAPES DURING THE AFTERNOON. WE EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS TO CROP UP...ESPECIALLY NORTH
AND WEST OF THE CAPITAL REGION. THE STORM PREDICTION CENTER HAS OUR
MOST OF OUR REGION IN MARGINAL WHICH MEANS SOME STRONG TO LOCALLY
SEVERE STORMS COULD HAPPEN LATER TODAY DUE TO INCREASING WINDS
ALOFT. WE WILL INTRODUCE ENHANCED WORDING FOR THUNDERSTORMS POSSIBLY
CONTAINING GUSTY WINDS. SOME HAIL IS POSSIBLE...BUT RIGHT NOW...WIND
APPEARS THE BIGGER THREAT.
THIS WILL BE THE LAST DAY OF THIS CURRENT WARM SPELL...WITH HIGHS IN
THE LOWER TO MID 80S IN THE VALLEYS...75-80 HIGHER TERRAIN.
THE WIND WILL BE OUT OF THE SOUTH AND BY AFTERNOON...MOST PLACES
WILL AVERAGE AROUND 10 MPH...WITH SOME GUSTS TO 20 MPH OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE AFOREMENTIONED COLD FRONT BE ACROSS THE SAINT LAWRENCE THIS
EVENING...AND WORK SOUTHWARD TOWARD THE CAPITAL REGION OVERNIGHT.
WITH AN INCREASING LOW LEVEL JET AND EVENTUALLY ANTICYLONICALLY
CURVED UPPER LEVEL JET ENTRANCE REGION...COMBINING WITH PWATS WELL
OVER 1.5 INCHES...THIS SET UP IS LOOKING MORE AND MORE LIKE A GOOD
BET TO BRING A SOAKING RAINFALL TO THE REGION THROUGH MONDAY.
NOW IT WILL PROBABLY NOT RAIN THE WHOLE TIME FRAME. INITIALLY IT
LOOKS LIKE A ROUND OF SHOWERS AND PERHAPS A FEW MORE EMBEDDED
THUNDERSTORMS TONIGHT RIGHT ALONG AND BEHIND THE COLD FRONT...AS IT
BECOMES PARALLEL TO THE SOUTHWEST FLOW ALOFT.
THERE MIGHT BE A REDUCTION IN SHOWERS ON SUNDAY AS ONE WAVE PASSES
BY. HOWEVER...IT LOOKS AS IF A STRONG WAVE OF LOW PRESSURE SHOULD
FORM BY LATE SUNDAY...TRACKING FROM THE SOUTHERN OHIO
VALLEY...WESTERN PA AND UP ACROSS NY STATE. THIS WILL BE THE BEST
SHOT OF STEADY RAIN...POSSIBLY MODERATE TO EVEN HEAVY AT TIMES
SUNDAY NIGHT INTO MONDAY.
IT WILL TURN NOTICEABLY CHILLIER BEHIND THE FRONT. THE FIRST AREAS
TO FEEL THIS WILL BE NORTH OF THE MOHAWK VALLEY SATURDAY NIGHT WHERE
TEMPERATURES WILL DROP INTO THE 50S...WHILE MUGGIER 60S WILL BE
COMMON FROM THE CAPITAL REGION SOUTHWARD.
SUNDAY...HIGH TEMPERATURES MIGHT HOLD IN THE MID OR UPPER 50S WELL
NORTH OF ALBANY...LOWER 60S IN THE CAPITAL REGION...STILL WARMER
SOUTH WHERE THE FRONT WILL LIKELY TO CLEAR UNTIL LATE IN THE DAY.
TEMPERATURES NEAR POUGHKEEPSIE WILL LIKELY POP INTO THE 70S.
MUCH COOLER EVERYWHERE ON MONDAY AS OUR REGION LOOKS TO REMAIN IN
THE COOL SECTORS...GENERALLY AROUND 70 SOUTH...LOWER TO MID 60S IN
AND AROUND THE CAPITAL REGION...60 OR LOWER NORTH. THESE VALUES ARE
MUCH CLOSER FOR THE 1ST DAY OF MAY AS OPPOSED TO THE FIRST DAY OF
JUNE.
TO THE SOUTH OF CAPITAL REGION...THERE COULD BE ENOUGH AFTERNOON
INSTABILITY FOR SOME THUNDERSTORM ACTIVITY ON SUNDAY AFTERNOON AS
THE FRONT CONTINUES TO WORK THROUGH.
CHECKING ANOMALIES...THE PWATS UP TO 1.75 INCHES CONTINUE TO BE 2-3
STANDARD DEVIATION ABOVE NORMAL. THE H850 SOUTHERLY COMPONENT REACHED
THE 1-2 STANDARD DEVIATION RANGE...AND THE 250 WIND (EAST WEST)
COMPONENT NEVER STRAYS THAT MUCH FROM NORMAL. THE 03Z SREFS AVERAGE
ABOUT 1.5 INCHES FOR ALBANY...WITH HIGHEST AMOUNTS AROUND 3.5
INCHES. THE 00Z GEFS WERE CONSIDERABLY HIGHER...AVERAGING AROUND 3
INCHES WITH MEMBERS AS HIGH AS 4 INCHES AND THE LOWEST VALUES AROUND
1.3 INCHES.
FOR NOW OUR QPF WAS BLEND OF THE GEFS/SREF. MORE ABOUT THE QPF CAN
BE FOUND IN OUR HYDROLOGY SECTION.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
EVEN THOUGH THE SURFACE WAVE AND HEAVIER RAINFALL WILL HAVE ALREADY
CLEARED THE REGION BY SUNRISE TUESDAY...WE CAN STILL EXPECT SOME
LINGERING SHOWERS TUESDAY DUE TO THE UPPER LOW THAT WILL BE MOVING
EASTWARD ACROSS SOUTHERN QUEBEC. SHOWER ACTIVITY WITH THIS FEATURE
WILL BE SCATTERED AT BEST...AND HAVE FORECAST POPS OF 40 TO 50
PERCENT TUESDAY MORNING...DECREASING TO 30 TO 40 PERCENT DURING THE
AFTERNOON. IT WILL BE PARTLY TO MOSTLY CLOUDY ON TUESDAY WITH HIGHS
IN THE UPPER 50S AND 60S.
TUESDAY NIGHT THROUGH FRIDAY LOOKS DRY AT THIS POINT WITH TEMPS
GRADUALLY RISING THROUGH THE PERIOD. A LARGE RIDGE OF HIGH PRESSURE
WILL BUILD ACROSS THE REGION. LOWS TUESDAY NIGHT WILL BE 40 TO 50.
HIGHS ON WEDNESDAY IN THE UPPER 60S TO LOWER 70S. LOWS WEDNESDAY
NIGHT IN THE UPPER 40S TO MID 50S. HIGHS THURSDAY IN THE 70S TO
LOWER 80S. LOWS THURSDAY NIGHT IN THE 50S. HIGHS FRIDAY IN THE MID
70S TO LOWER 80S.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT WILL BE APPROACHING THE REGION FROM THE WEST TODAY
AND TONIGHT. IT WILL LIKELY MOVE THROUGH KGFL BEFORE THE END OF
THE TAF PERIOD AT 12Z SUNDAY...BUT REMAIN TO THE NORTH AND WEST OF
KALB/KPOU/KPSF.
EXPECT MAINLY VFR CONDITIONS AT THE KGFL/KALB/KPOU/KPSF TAF SITES
THROUGH MOST OF TODAY WITH MAINLY MID/HI CLOUDS AND SCT CUMULUS.
THE EXCEPTION WILL BE EARLY THIS MORNING WHERE A MVFR STRATUS DECK
WAS OVER KPOU AS OF 630 AM. THIS STRATUS DECK SHOULD MIX OUT BY
AROUND 14Z.
SHOWERS WILL BE ADVANCING ACROSS THE REGION LATR TODAY...AND HAVE
PLACED VCSH IN THE TAFS AT KGFL/KALB/KPSF AFTER 21Z...AND INCLUDED
A PROB30 GROUP FOR THUNDERSTORMS WITH IFR/MVFR CONDITIONS BETWEEN
30/21Z- 22Z AND 31/03Z-04Z. AT KPOU THE VCSH STARTS AT 23Z WITH
THE PROB30 GROUP FROM 30/23Z TO 31/05Z. AFTER THE THREAT OF
TSTMS...HAVE FORECAST CIGS/VSBYS LOWERING TO MVFR AT KGFL/KALB/KPSF
BETWEEN 03Z AND 04Z AS A MORE WIDESPREAD AREA OF SHOWERS MOVES IN.
BETWEEN 06Z AND 09Z...VSBYS SHOULD LOWER EVEN FURTHER...WITH CIGS
LOWERING INTO THE IFR RANGE AT KGFL/KALB/KPSF.
SOUTHERLY WINDS WILL BE INCREASING TODAY...REACHING SPEEDS OF 10
TO 15 KTS WITH GUSTS OF 20 TO 25 KTS DURING THE AFTERNOON AND
EARLY EVENING. BY MIDNIGHT WINDS WILL DECREASE TO AROUND 10
KTS...WITH SOME GUSTS OVER 15 KTS AT KALB. AT KGFL...WINDS WILL
SHIFT TO NORTHERLY AROUND 09Z AS THE COLD FRONT MOVES THROUGH.
OUTLOOK...
SUN-MON: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
MON NIGHT-TUE: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
TUE NIGHT-WED: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
MOST AREAS WILL START OFF WITH HIGH RH VALUES TODAY...IN THE 75-90
PERCENT RANGE. RH VALUES WILL ONLY FALL TO AROUND 50 PERCENT THIS
AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON WITH ANY THUNDERSTORMS POSSIBLY CONTAINING GUSTY WINDS.
THE MOST NUMEROUS STORMS SHOULD BE NORTH AND WEST OF THE CAPITAL
REGION...LESS NUMEROUS SOUTH AND EAST OF THE CAPITAL REGION.
THEN...IT LOOKS AS IF A SOAKING RAIN IS LIKELY HAPPEN TONIGHT
THROUGH AT LEAST MONDAY. WHILE IT NOT BE RAINING ALL OF THIS
TIME...THERE IS POTENTIAL FOR MODERATE TO HEAVY RAINFALL AT TIMES.
IT IS ALMOST A CERTAINTY EVERYONE WILL END UP WITH WELL OVER A
QUARTER INCH OF RAINFALL...MOST AREAS LIKELY RECEIVING AROUND TWO
INCHES OF RAINFALL.
DRYING CONDITIONS ARE EXPECTED TUESDAY THROUGH THURSDAY AS THE RAINS
ARE REPLACED BY DRIER AND EVENTUALLY A RETURNS TO WARMER WEATHER.
&&
.HYDROLOGY...
A WIDESPREAD SIGNIFICANT RAINFALL AS COLD FRONT APPROACHES AND
SLOWLY MOVES ACROSS THE REGION AS A WAVE OF LOW PRESSURE MOVES ALONG
THE BOUNDARY. SHOWERS AND THUNDERSTORMS ARE EXPECTED MAINLY THIS
AFTERNOON INTO THE EVENING WELL AHEAD OF THE COLD FRONT. A WAVE OF
LOW PRESSURE WILL FORM ON THE BOUNDARY SLOWING ITS PROGRESS ACROSS
THE REGION AND RESULTING IN SHOWERS ACROSS THE REGION. AT THIS
TIME...A WIDESPREAD 1 TO 3 INCHES OF RAINFALL IS FORECAST THROUGH
MONDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE. HAVE ADDED MENTION TO
OUR HAZARDOUS WEATHER OUTLOOK THAT IF THE THREAT OF HEAVY RAINFALL
BECOMES MORE CERTAIN A FLOOD WATCH MAY BE ISSUED. ON THE OTHER
HAND...THIS WILL LIKELY BE BENEFICIAL RAINFALL SINCE MUCH OF OUR
REGION HAS ONLY SEEN ABOUT HALF ITS NORMAL RAINFALL SO FAR THIS
YEAR.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
FIRE WEATHER...HWJIV
HYDROLOGY...IAA/HWJIV
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
843 AM EDT SAT MAY 30 2015
.UPDATE...12Z SOUNDINGS CONFIRM RADAR TRENDS...WITH DRY AIRMASS
WRN HALF OF FORECAST AREA...GREATER LOW-LEVEL MOISTURE ERN HALF.
RADAR SHOWING SCT`D SHOWERS AFFECTING COASTLINE. HRRR AND NAM
SUGGEST WEAK COASTAL TROUGH WILL WORK WESTWARD...MOVING WELL
INLAND THIS AFTERNOON. SHOULD SEE SHOWER ACTIVITY SHIFT FROM
COASTAL/EASTERN AREAS THIS MORNING TO WESTERN AREAS THIS
AFTERNOON. PRIMARILY SHOWERS EXPECTED EASTERN AREAS...SOME
HEATING COULD SUPPORT A FEW T-STORMS WESTERN AREAS THIS AFTERNOON.
CURRENT HOURLY POP TRENDS SHOW THIS WELL. ANTICIPATING SIMILAR
HIGH TEMPS TODAY VS. YESTERDAY...88-90 INTERIOR...84-87 EASTERN
AREAS AND COAST.
&&
.AVIATION...GENERALLY VFR CONDITIONS...EXCEPT OCCASIONAL MVFR
VICINTY OF SCATTERED SHOWERS. BEST CHANCE OF TSRA VICINITY KGNV
THIS AFTERNOON GIVEN SOME DAYTIME HEATING.
&&
.MARINE...NO SIG CHANGES PLANNED IN NEXT CWF ISSUANCE. CONTINUED
ONSHORE FLOW PATTERN THIS WEEKEND WITH E TO SE WINDS 10-15 KTS
AND 3-5 FT SEAS.
RIP CURRENTS: MODERATE RISK THIS WEEKEND WITH CONTINUED ONSHORE
FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 88 68 90 68 / 30 10 40 40
SSI 83 73 83 73 / 40 20 20 0
JAX 86 69 88 71 / 40 10 30 0
SGJ 84 72 84 71 / 40 20 20 0
GNV 88 67 90 68 / 30 10 50 30
OCF 89 68 91 69 / 40 10 50 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
WOLF/GUILLET
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
613 AM CDT SAT MAY 30 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 248 AM CDT SAT MAY 30 2015
THE ATMOSPHERE IS EVOLVING TOWARD A MORE TYPICAL LATE SPRING/EARLY
SUMMERTIME PATTERN WITH RIDGING BUILDING INTO THE CENTRAL PART OF THE
COUNTRY AND A NORTHWARD SHIFT OF THE JET. VERY WARM SEA SURFACE
TEMPERATURES CONTINUE IN THE EASTERN NORTH PACIFIC, AND SEA SURFACE
TEMPERATURES NEAR THE EQUATOR ARE VERY WARM FROM THE COAST OF SOUTH
AMERICA TO NEAR 160E. ATMOSPHERIC KELVIN WAVES CONTINUE TO RIPPLE
AROUND THE GLOBE, AND A LARGE AREA OF UPPER LEVEL DIVERGENCE WITH A
KELVIN WAVE IS ENHANCING THUNDERSTORM ACTIVITY IN THE TROPICAL EAST
PACIFIC, WHERE HURRICANE ANDRES HAS DEVELOPED. THIS KELVIN WAVE LIKELY
WILL CONTINUE TO PROPAGATE EAST THROUGH THE WESTERN HEMISPHERE AND
SHOULD REACH THE INDIAN OCEAN BY MID JUNE. THE NUMERICAL MODELS DIFFER
CONSIDERABLY ON THE AMPLITUDE OF THE COHERENT SIGNAL AND ITS
EVOLUTION. THE ECMWF MAINTAINS A CONSISTENT EASTWARD PROPAGATION OF
THE SIGNAL AND SEEMS REASONABLE GIVEN THE STRENGTH OF THE HIGH LEVEL
DIVERGENCE NEAR 100W AND THE CONSISTENT PROPAGATION SPEED OF KELVIN
WAVES AROUND THE GLOBE IN RECENT WEEKS. AS SUCH, ENHANCED TROPICAL
THUNDERSTORM ACTIVITY IS LIKELY IN PHASE TWO OF THE WHEELER-HENDON
PHASE-SPACE DIAGRAM THE FIRST WEEK OF JUNE PROBABLY EXTENDING INTO
PHASE THREE THE SECOND WEEK OF JUNE. ENHANCED TROPICAL THUNDERSTORMS
IN PHASE TWO OF THE WHEELER-HENDON PHASE SPACE DIAGRAM ARE CORRELATED
WITH ANTICYCLONIC FLOW FROM THE SOUTHWESTERN STATES TO THE MID
ATLANTIC AND A TENDENCY FOR TROUGHING IN THE WESTERN PART OF THE
COUNTRY. THE ECMWF MAY BE A LITTLE TOO STRONG WITH TROUGH IN
CALIFORNIA LATE NEXT WEEK, BUT MAINTENANCE OF RIDGING IN THE SOUTHERN
PLAINS AND SOUTHEASTERN UNITED STATES SEEMS LIKE A MORE REASONABLE
SOLUTION THAN THE TROUGHING ADVERTISED BY THE GFS.
IN THE MORE IMMEDIATE FUTURE, VERY QUIET WEATHER CAN BE EXPECTED IN
KANSAS TODAY AND SUNDAY. AN UPPER LEVEL TROUGH EXTENDING FROM EASTERN
NEBRASKA INTO SOUTHERN COLORADO WILL CONTINUE MOVING SOUTHEAST AND
WILL EXTEND FROM NORTHERN MISSOURI INTO WESTERN OKLAHOMA BY THIS
EVENING. SHORT WAVE RIDGING WILL BUILD OVER WESTERN KANSAS THIS
AFTERNOON AND TONIGHT. THE COLD FRONT THAT MOVED RAPIDLY THROUGH
WESTERN KANSAS FRIDAY AFTERNOON AND EVENING WILL REACH CENTRAL TEXAS
BY EARLY AFTERNOON, AND CANADIAN HIGH PRESSURE WILL BUILD INTO KANSAS.
AN EXTENSIVE AREA COLD AIR ADVECTION STRATUS BEHIND THE COLD FRONT HAD
INVADED NEARLY ALL OF WESTERN KANSAS BY 07Z, BUT CLEARING WAS EVIDENT
ON SATELLITE IMAGERY IN THE DIVERGENT LOW LEVEL FLOW IN CENTRAL AND
NORTHERN NEBRASKA. THE STRATUS SHOULD ERODE FROM NORTHERN KANSAS SOON
AFTER SUNRISE AND LIKELY WILL BE GONE FROM ALL OF WESTERN KANSAS BY
LATE MORNING. TEMPERATURES WILL BE SEVERAL DEGREES COOLER TODAY THAN
ON FRIDAY EVEN WITH LOTS OF SUNSHINE AFTER THE STRATUS ERODES. NORTH
WINDS WILL DECREASE DURING THE DAY AS THE PRESSURE GRADIENT WEAKENS,
AND LIGHT EAST WINDS WILL DEVELOP BY SUNSET.
AN UPPER LEVEL TROUGH WILL MOVE FROM THE PACIFIC NORTHWEST ACROSS THE
ROCKIES TO THE NORTHERN PLAINS BY SUNDAY MORNING, AND INCREASING FLOW
PERPENDICULAR TO THE NORTHERN ROCKIES WILL FAVOR INTENSIFICATION OF
LEE TROUGHING. LOW LEVEL SOUTH WINDS WILL INCREASE SATURDAY NIGHT AND
PROVIDE SUFFICIENT MIXING TO KEEP MINIMUM TEMPERATURES IN THE LOWER
50S IN FAR WESTERN KANSAS. TEMPERATURES WILL BE A FEW DEGREES COOLER
IN CENTRAL KANSAS, WHERE WINDS WILL BE LIGHTER. SKIES SHOULD BE MOSTLY
CLEAR SATURDAY NIGHT, ALTHOUGH SOME INCREASE IN CIRRIFORM CLOUDINESS
IS LIKELY SUNDAY. PRECIPITATION CHANCES ARE NEAR ZERO THROUGH LATE
SUNDAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 325 AM CDT SAT MAY 30 2015
A TROUGH OF LOW PRESSURE ALONG THE LEE OF THE ROCKIES IS EXPECTED
TO REMAIN NEARLY STATIONARY ON SUNDAY AN UPPER LEVEL RIDGE MOVES
EAST INTO THE ROCKIES. A SURFACE BOUNDARY WILL LIFT NORTH AS A
WARM FRONT ACROSS SOUTHWEST KANSAS LATE SUNDAY, AND AS MOISTURE
AND WARM AIR ADVECTION IMPROVES NORTH OF THIS BOUNDARY THERE WILL
BE A CHANCE FOR SOME OVERNIGHT THUNDERSTORMS. AT THIS TIME THE
AREA MORE FAVORABLE FOR OVERNIGHT CONVECTION APPEARS TO BE IN
NORTH CENTRAL KANSAS WHICH WILL BE JUST EAST OF A 700MB BAROCLINIC
ZONE AND AHEAD OF AN UPPER LEVEL DISTURBANCE THAT WILL BE ROTATING
AROUND THE UPPER LEVEL RIDGE AXIS. WILL KEEP A MENTION OF
CONVECTION GOING THROUGH EARLY MONDAY BASED ON TIMING OF THE UPPER
LEVEL DISTURBANCE AS IT CROSSES INTO CENTRAL KANSAS.
THE WARMER TEMPERATURES ARE EXPECTED ON MONDAY AS 850MB AND 700MB
TEMPERATURES CONTINUE TO WARM ACROSS WESTERN KANSAS. 700MB
TEMPERATURES ACROSS WESTERN KANSAS ARE FORECAST TO BE IN 10 TO
NEAR 13C RANGE BY 00Z TUESDAY AS ANOTHER UPPER LEVEL DISTURBANCE
EXITS THE CENTRAL ROCKIES AND APPROACHES WESTERN KANSAS. LATE DAY
CONVECTION WILL BE POSSIBLE ALONG THE LEE SURFACE TROUGH WHICH
WILL BE LOCATED WEST OF THE COLORADO BORDER, HOWEVER THESE STORMS
SHOULD WEAKEN/DISSIPATE AFTER SUNSET AS THEY APPROACH FAR WESTERN
KANSAS. ANOTHER AREA FAVORABLE FOR OVERNIGHT CONVECTION WILL ONCE
AGAIN BE NORTH OF THE WARM FRONT AND ALONG THE NORTHEASTERN EDGE
OF THE WARM 700MB TEMPERATURES. NAM AND GFS DIFFERS ON WHERE THE
NORTHEASTERN EDGE OF THE WARM LAYER WILL BE LOCATED MONDAY NIGHT
SO AT THIS TIME WILL STAY WITH PERSISTENCE AND NOT MENTION
PRECIPITATION JUST YET ACROSS NORTH CENTRAL KANSAS. BASED ON 850MB
TEMPERATURES MONDAY AFTERNOON WILL CONTINUE TO FAVOR HIGHS IN THE
MID TO UPPER 80S, ESPECIALLY WEST OF HIGHWAY 283.
GFS AND ECMWF BOTH SHIFT THE UPPER RIDGE AXIS EAST INTO THE
CENTRAL PLAINS TUESDAY AND WEDNESDAY. THE 700MB TEMPERATURES OVER
SOUTHWEST KANSAS BOTH DAYS ARE FORECAST TO RANGE FROM +12C AND
NEAR +16C. 850MB TEMPERATURES WERE FORECAST TO RANGE FROM THE
UPPER 20S TO LOWER 30S. BASED ON THESE TEMPERATURES EXPECTED ALONG
WITH THE RECENT RAINFALL ACROSS WESTERN KANSAS WILL STAY CLOSE TO
THE LATEST CREXTENDEDFCST_INIT FOR HIGHS BOTH ON TUESDAY AND
WEDNESDAY RANGING FROM 85 TO NEAR 90. PRECIPITATION CHANCES SHOULD
BE NORTH AND EAST OF SOUTHWEST KANSAS ON TUESDAY BASED ON THE WARM
TEMPERATURES IN THE MID LEVELS. WEDNESDAY NIGHT THERE WILL BE A
BETTER CHANCE FOR CONVECTION WILL BE POSSIBLE ACROSS NORTHERN
KANSAS.
MODELS BEGIN TO DIVERGE LATE WEEK ON THE EVOLUTION OF AN UPPER
LEVEL TROUGH AS IT BEGINS TO CROSS THE SOUTHWEST UNITED STATES.
DESPITE THE DIFFERENCES IN THE LATER PERIODS BOTH THE GFS AND
ECMWF KEEPS A SOUTHWESTERLY FLOW PRESENT OVER THE CENTRAL HIGH
PLAINS. SEVERAL UPPER LEVEL WAVES WILL BE EMBEDDED IN THIS
SOUTHWEST FLOW AND AS THEY CROSS THE CENTRAL PLAINS THERE WILL BE
A CHANCE FOR CONVECTION EACH DAY LATE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 612 AM CDT SAT MAY 30 2015
BUFR SOUNDINGS AND THE LATEST HRRR WERE BOTH IN GOOD AGREEMENT
WITH CLEARING SKIES DEVELOPING BY LATE MORNING ACROSS WESTERN
KANSAS. HYS WILL BEGIN THIS TAF CYCLE WILL VFR CONDITIONS. THE LOW
MVFR CEILINGS AT DDC AND GCK AT 12Z SATURDAY WILL GIVE WAY TO VFR
CONDITIONS BETWEEN 15Z AND 17Z. GUSTY NORTH WINDS WILL DECREASE TO
AROUND 10 KNOTS BY 18Z SATURDAY AS AN AREA OF HIGH PRESSURE AT THE
SURFACE BEGINS TO BUILD INTO WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 71 48 78 57 / 0 0 0 10
GCK 69 49 80 59 / 0 0 0 20
EHA 71 54 83 60 / 0 0 0 10
LBL 71 49 80 60 / 0 0 0 10
HYS 69 45 77 56 / 0 0 0 30
P28 71 49 78 57 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUTHI
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1100 AM EDT SAT MAY 30 2015
.UPDATE...
ISSUED AT 1100 AM EDT SAT MAY 30 2015
14Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE EAST STILL HOLDING
SOME INFLUENCE OVER FAR EASTERN KENTUCKY WHILE AN AREA OF LOW
PRESSURE IS MOVING INTO THE MID MISSISSIPPI VALLEY. THE PRESSURE
GRADIENT BETWEEN THESE FEATURES IS RESULTING IN A CONTINUED FLOW
OF WARM AND MOIST AIR INTO EASTERN KENTUCKY. SPECIFICALLY...
READINGS ARE NOW IN THE MID TO UPPER 70S THROUGH THE AREA WHILE
DEWPOINTS HOLD IN THE MID 60S FOR MOST PLACES ALONG WITH SOUTH
WINDS AT 5 TO 10 KTS. A BIT MORE IN THE WAY OF LOW AND MID LEVEL
CLOUDS OVERNIGHT HELPED TO LIMIT THE FOG DEVELOPMENT THIS MORNING
AND NOW ALL THAT IS GONE...WHILE PARTLY CLOUDY CONDITIONS REMAIN.
A ROGUE AREA OF SHOWERS MOVED NORTH THROUGH THE CUMBERLAND VALLEY
EARLIER IN THE MORNING...THOUGH THESE HAVE NOW DISSIPATED. BASED
ON THE LATEST HRRR AND INCOMING NAM12...ALONG WITH DIURNAL
CLIMATOLOGY... EXPECT SCATTERED CONVECTION TO REDEVELOP OVER THE
AREA SHORTLY AFTERNOON. THE BETTER COVERAGE SHOULD BE CONCENTRATED
OVER OUR WESTERN COUNTIES LATE IN THE DAY CLOSER TO THE SFC LOW
AND IS SLOWLY APPROACHING FRONT. HOWEVER...THE HRRR IS MORE
INSISTENT THAT CONVECTION IS EQUALLY POSSIBLE FURTHER EAST AND
GIVEN THIS ENVIRONMENT...OF INCREASING INSTABILITY AND NO
CAPPING...WILL NOT RULE IT OUT. ACCORDINGLY...HAVE BROUGHT HIGH
CHANCE POPS A BIT FURTHER EAST WITH THIS UPDATE. ANY STORMS THAT
DEVELOP COULD BECOME STRONG WITH ENOUGH WIND SHEAR ALOFT TO
SUGGEST A POTENTIAL FOR STRONGER WIND GUSTS THAN WE SAW YESTERDAY.
THE ENTIRE AREA REMAINS IN A MARGINAL RISK FOR JUST THAT FROM SPC
WHILE A SLIGHT RISK OUTLOOK IS FOUND JUST TO OUR NORTHWEST. ANY
LATE DAY STORM WILL NEED TO BE MONITORED CLOSELY FOR SEVERE
POTENTIAL. THE UPDATED GRIDS...INCLUDING ADJUSTMENTS TO THE T/TD
GRIDS PER THE LATEST SHORTBLEND GUIDANCE...OBS...AND TRENDS...
HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. IN ADDITION...A
TOUCHED UP SET OF ZONES...MAINLY REMOVING THE MORNING FOG
WORDING...HAS BEEN SENT.
UPDATE ISSUED AT 739 AM EDT SAT MAY 30 2015
FOG IS LIFTING ACROSS THE REGION AS THE SUN BEGINS TO RISE. A FEW
LOCATIONS IN THE EAST ARE STILL REPORTING VIS BELOW 2 MILES. AS A
RESULT...UPDATED THE WEATHER GRIDS TO TAKE OUT FOG IN THE WESTERN
CWA...AND THE DENSE FOG IN THE EAST. FOG WILL CONTINUE TO LIFT
AND DISSIPATE ACROSS THE EAST OVER THE NEXT HOUR OR TWO...SO LEFT
IN FORECAST THROUGH 12Z. ALSO...RAIN SHOWERS ARE ALREADY STARTING
TO DEVELOP ACROSS PORTIONS OF EASTERN KY...MOVING NNE. ALSO
UPDATED POPS AND WEATHER GRIDS TO REFLECT THE EARLIER ONSET OF
CONVECTION. ONCE THE LATEST OBSERVATIONS WERE INGESTED INTO THE
DATABASE...LOADED THESE INTO THE FORECAST TO MAKE SURE CURRENT
CONDITIONS WERE WELL REFLECTED IN THE NEAR TERM FORECAST.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 418 AM EDT SAT MAY 30 2015
AFTER RAINS IMPACTED SECTIONS OF THE CWA YESTERDAY...LINGERING
MOISTURE HAS LED TO DECENT AREAS OF FOG DEVELOPMENT DURING THE
OVERNIGHT HOURS. PATCHY DENSE FOG HAS ALSO BEEN OBSERVED...AND
WILL LIKELY CONTINUE THROUGH THE EARLY MORNING HOURS. AS THE SUN
BEGINS TO RISE THIS MORNING...EXPECT FOG TO LIFT AND GIVE WAY TO
MOSTLY TO PARTLY SUNNY SKIES ACROSS THE REGION THIS MORNING.
UPPER LEVEL RIDGING OFF THE SOUTHEAST ATLANTIC CONUS WILL SLOWLY
BREAK DOWN OVER THE NEXT DAY AS TROUGHING OVER THE MISSISSIPPI RIVER
VALLEY SHIFTS EASTWARD AND ACROSS THE OHIO RIVER VALLEY. THIS SHIFT
WILL BE OUR PRIMARY WEATHER DRIVER OVER THE NEXT 2 DAYS. AT THE
SURFACE...A LOW PRESSURE SYSTEM...CURRENTLY MOVING ACROSS
MISSOURI...WILL REACH WESTERN INDIANA BY THIS EVENING...THEN
CONTINUE TO SHIFT NORTHEAST...JUST NORTH OF THE OHIO
RIVER...THROUGH SATURDAY NIGHT AND INTO SUNDAY MORNING. AS THIS
OCCURS...A COLD FRONT IS EXPECTED TO PUSH THROUGH KENTUCKY. STILL
FAVORING THE GFS SOLUTION OF THE FRONTAL PASSAGE...WHICH SHOULD
TRAVERSE WESTERN KY LATE TONIGHT...CENTRAL KY THROUGH 12Z
SUNDAY...AND STALL OUT ACROSS THE HIGH TERRAIN OF KY BETWEEN 18Z
SUNDAY AND 0Z MONDAY.
FOR TODAY...CONTINUED STRONG WARM MOIST SOUTHERLY FLOW AHEAD OF THE
BOUNDARY WILL BRING YET ANOTHER HIGH HUMIDITY/WARM WEATHER DAY TO
THE REGION...AS WELL AS THE POTENTIAL FOR CONVECTIVE DEVELOPMENT. AS
HAS BEEN THE CASE IN THE PREVIOUS DAYS...BEST CHANCES FOR CONVECTION
WILL BE IN THE AFTERNOON WITH PEAK HEATING AND INSTABILITY. LATEST
FORECAST SOUNDINGS FOR TODAY DON/T LOOK OVERLY IMPRESSIVE FOR SEVERE
POTENTIAL...BUT COULD STILL SEE SOME GOOD RAINERS AND DECENT
LIGHTNING FROM ANY THUNDERSTORM THAT DEVELOPS. AS WE LOSE DAYTIME
HEATING...EXPECT COVERAGE TO DECREASE INTO THE OVERNIGHT
HOURS...ESPECIALLY IN THE SE PORTION OF THE CWA AWAY FROM THE BEST
FORCING OF THE INCOMING FRONT. BEGAN INCREASING POPS AGAIN BY 12Z
SUNDAY AS SUN BEGINS TO INFLUENCE UNSTABLE AIRMASS ONCE
MORE...PEAKING AS THE FRONT BEGINS PASSING OVER DURING THE AFTERNOON
HOURS. FORECAST SOUNDINGS ARE SHOWING BETTER HAIL POTENTIAL DURING
THE DAY SUNDAY...WITH MUCH MORE DRYING ALOFT AND DECENT CAPE VALUES
IN THE 2 TO 3K J/KG RANGE. LAPSE RATES ARE NOT SUPER
IMPRESSIVE...BUT LI/S WILL DROP INTO THE -5 TO -6C RANGE IN SOME
LOCATIONS...INDICATING GOOD POTENTIAL FOR THUNDERSTORM INITIATION.
ALL IN ALL...EXPECT SOME DECENT SCATTERED STORM DEVELOPMENT TO
POTENTIALLY TAKE PLACE OVER SOUTHEAST KY...WHICH CORRESPONDS WELL TO
SPC/S MARGINAL RISK OVER THIS SAME AREA FOR SUNDAY. SOMETHING TO
WATCH OUT FOR. HOWEVER...DID NOTE THE LEVEL OF MOISTURE IN THE
SOUNDINGS ARE QUITE SHALLOW...WITH UNIMPRESSIVE PWATS...SO NOT
EXPECTING MUCH HYDRO CONCERNS...UNLESS STORMS CONTINUE TO IMPACT THE
SAME LOCATIONS MULTIPLE TIMES.
WITH SUCH A STRONG SOUTHERLY FLOW EXPECTED TODAY...TEMPERATURES
COULD WARM WELL INTO THE MID 80S ACROSS MUCH OF THE REGION...WITH
CONTINUED HIGH HUMIDITY VALUES. HOWEVER...WITH INCREASED CLOUD COVER
OVERNIGHT AND INTO TOMORROW...AS WELL AS WINDS SHIFTING TO A MORE NW
DIRECTION BEHIND THE FRONT...EXPECT TEMPERATURES TO ONLY REACH THE
UPPER 70 TO LOW 80 RANGE FOR DURING THE DAY SUNDAY /COOLEST IN THE
WEST/. OVERALL...SUPERBLEND AND GFS WERE THE MODELS OF CHOICE DURING
THE SHORT TERM...THOUGH MOST SHORT TERM MODELS SEEMED TO BE IN
DECENT AGREEMENT WITH ONE ANOTHER.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 418 AM EDT SAT MAY 30 2015
THE EXTENDED FORECAST PERIOD BEGINS ON SUNDAY NIGHT WITH A PRETTY
ACTIVE AND PROGRESSIVE PATTERN IN PLACE. AS AN UPPER LOW BEGINS TO
EXIT THE OH VALLEY AREA AND A COLD FRONT PUSHES THROUGH THE AREA.
THE FRONT DOES WASH OUT A BIT AND INSTABILITY WILL BEGIN TO BECOME
TIED TO DIURNAL TRENDS BUT WILL KEEP POPS THROUGH THE SUNDAY NIGHT
PERIOD AND TRANSITION TO SLIGHT CHANCE POPS INTO MONDAY AFTERNOON.
TEMPERATURES REALLY COOL OFF WITH LOWER 70S EXPECTED WITH THE
APPROACHING COOLER AIR MASS. THE FRONT THEN BECOMES A STALLED
BOUNDARY ALONG THE KY/TN BORDER AND ALONG THE VA/KY BORDER AND SO
WILL KEEP SLIGHT CHANCE POPS EACH DAY ALONG THE HIGH TERRAIN AREAS
THERE. THIS WILL BE THE CASE EACH DAY FROM MONDAY THROUGH
WEDNESDAY WITH THE MAX CHANCE OCCURRING EACH DAY DURING THE
AFTERNOON BUT DID GO BELOW THE SUPER BLEND SOLUTION WITH THE LACK
OF UPPER LEVEL SUPPORT AND COLLABORATION WITH THE NEIGHBORING
OFFICES.
BY THURSDAY...WITH AN INCREASED SOUTHERLY FLOW...A WEAK WAVE
OVERHEAD...AND THE MENTIONED STATIONARY BOUNDARY...A BETTER CHANCE
FOR PRECIP WILL BE ON TAP FRO THURSDAY AFTERNOON AND FRIDAY
AFTERNOON. THIS PERIOD WILL STILL MAINTAIN A DIURNAL TREND TO ANY
CONVECTION. STILL KEPT CLOSE TO THE SUPER BLEND SOLUTION BUT DID
NUDGE POPS BELOW A BIT DURING THE FEW DAYS WITH LACK OF UPPER
LEVEL SUPPORT. OVERALL...BESIDES THE EXITING COLD FRONT ON SUNDAY
NIGHT...NO DOMINANT WEATHER FEATURE WILL PROVIDE A DEFINITE CHANCE
OF PRECIP OR AT LEAST THE LACK OF CONSISTENCY IN THE MODELS IS
SUCH THAT NOTHING ABOVE SLIGHT CHANCE POPS IS DISCERNIBLE. FOR
THIS FACT...DID STAY RATHER CLOSE TO THE SUPER BLEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 746 AM EDT SAT MAY 30 2015
FOG WILL QUICKLY BURN OFF ACROSS EASTERN KY OVER THE NEXT HOUR AND
VFR CONDITIONS WILL TAKE HOLD THROUGH MUCH OF THE DAY. STRONG
SOUTHERLY FLOW WILL CONTINUE THE TREND OF WARM MOIST CONDITIONS
ACROSS THE REGION. THIS WILL RESULT IN CU DEVELOPMENT AND
SCATTERED SHOWERS AND THUNDERSTORMS THROUGHOUT THE DAY. LIGHT
SHOWERS ARE ALREADY STARTING TO DEVELOP THIS MORNING BUT HAVE SO
FAR HAD LITTLE IMPACT. GIVEN THAT THE EXACT LOCATION AND TIMING OF
THESE DEVELOPING STORMS IS UNKNOWN...CONTINUED WITH MENTION OF
VCTS FOR THE HOURS WHEN STORMS ARE MOST LIKELY EXPECTED. DAYTIME
MIXING WILL ALSO LEAD TO SOME DECENT WIND GUSTS IN THE 10 TO 20KT
RANGE DURING THE AFTERNOON HOURS. BY THIS EVENING...CONVECTION
WILL BEGIN A DOWNWARD TREND AS WE LOSE BEST INSTABILITY AND
HEATING. WINDS WILL ALSO DIMINISH...WITH PATCHY/AREAS OF FOG
TAKING HOLD ACROSS PORTIONS OF THE REGION ONCE MORE. UNLESS RAIN
DIRECTLY AFFECTS A TAF SITE THIS EVENING...EXPECT MOST OF THE FOG
TO REMAIN IN THE VALLEYS AND NOT AFFECT TAF SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JMW
LONG TERM...SHALLENBERGER
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS PADUCAH KY
650 AM CDT SAT MAY 30 2015
.UPDATE...
ISSUED AT 650 AM CDT SAT MAY 30 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 324 AM CDT SAT MAY 30 2015
A WELL-DEVELOPED MCV OVER CENTRAL ARKANSAS AND ASSOCIATED SURFACE
LOW OVER NORTH CENTRAL ARKANSAS AS OF 08Z ARE FORECAST BY ALL
AVAILABLE GUIDANCE TO LIFT NORTHEAST ACROSS OUR AREA TODAY. THEY
SHOULD REACH SOUTHEAST MISSOURI BY MIDDAY AND THEN MOVE ACROSS THE
REMAINDER OF THE REGION THROUGH SUNSET. LATEST RADAR TRENDS
INDICATE THAT SCATTERED SHOWERS WILL LIFT NORTH OF OUR SOUTHEAST
MISSOURI COUNTIES BY 09Z AND MOST...IF NOT ALL...OF THE AREA
SHOULD BE DRY AT SUNRISE.
THE LATEST HRRR AND THE 00Z NMM AND ARW WRF RUNS DEVELOP SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE AREA BY
MIDDAY...AND MAINTAIN GOOD COVERAGE OF CONVECTION THROUGH THE
AFTERNOON...BEFORE COMING TO AN END FROM SOUTHWEST TO NORTHEAST
THIS EVENING.
LIKELY TO CATEGORICAL POPS SEEM LIKE THE WAY TO GO. NOT SURE HOW
MUCH HEATING WE WILL BE ABLE TO MUSTER WITH LOTS OF CLOUDS
EXPECTED THROUGH THE DAY...BUT CANNOT RULE OUT A STRAY STRONG
STORM WITH DAMAGING WINDS. ORGANIZED SEVERE WEATHER SEEMS
UNLIKELY TODAY. LOCALLY HEAVY RAINFALL AND LIGHTNING WILL BE THE
PRIMARY CONCERNS.
SOUTH WINDS WILL PICK UP ACROSS THE AREA THIS MORNING...AND MAY
PUSH LAKE WIND ADVISORY CRITERIA OVER MUCH OF THE REGION.
HOWEVER...WILL NOT BE ISSUING AN ADVISORY AT THIS TIME...MAINLY
DUE TO THE EXPECTED COVERAGE OF CONVECTION.
IN THE WAKE OF THE SURFACE LOW...SURFACE HIGH PRESSURE WILL BEGIN
TO BUILD ACROSS THE AREA LATE TONIGHT AND SUNDAY. REALLY NOT
SEEING MUCH IN THE WAY OF QPF FROM THE 00Z MODELS ON SUNDAY...BUT
WITH THE LARGER-SCALE MID/UPPER-LEVEL TROUGH MOVING THROUGH THE
REGION...CANNOT RULE OUT AN ISOLATED SHOWER OR STORM OVER THE
SOUTHEAST HALF OF THE REGION.
THE FORECAST IS DRY FROM SUNDAY NIGHT THROUGH MONDAY NIGHT AS
COOL...DRY SURFACE HIGH PRESSURE DOMINATES THE REGION.
TEMPERATURES TODAY THROUGH SUNDAY WILL BE HIGHLY DEPENDENT ON
CLOUDS AND CONVECTION. THE CONSENSUS OF GUIDANCE IS TRENDING
COOLER...AND WAS FOLLOWED PRETTY CLOSELY THROUGH THE ENTIRE SHORT
TERM PERIOD
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 324 AM CDT SAT MAY 30 2015
WHAT A DIFFERENCE 24 HRS MAKES. THOUGH THERE WERE HINTS PREVIOUSLY
THAT IT MIGHT HAPPEN...THE MED RANGE MODELS HAVE NOW TRENDED MUCH
DRIER IN THE EXTENDED PERIOD...ESPECIALLY IN THE FIRST HALF. THE
PREVIOUSLY SUGGESTED RIDGING ALOFT OVER THE PAH FORECAST AREA
APPEARS TO HAVE MORE DOMINANCE NOW AS A DOME OF SFC HIGH PRESSURE
SLOWLY FILTERS INTO THE AREA INITIALLY. AS A WRN CONUS TROF PERSISTS
IN VARYING DEGREES ACCORDING TO DIFFERENT MODEL SOLUTIONS...SOME
VERSION OF MID LEVEL RIDGING SHOULD PREVAIL OVER OUR REGION
THROUGHOUT THE EXTENDED PERIOD...WITH THE NRN STREAM REMAINING
ACTIVE. LATER IN THE PERIOD...A WEAKNESS IN THE ERN CONUS RIDGE
APPEARED TO BE FAR AWAY ENOUGH FROM THE PAH FORECAST AREA (THE
ATLANTIC COAST) AS TO NOT HAVE A DIRECT INFLUENCE ON OUR WEATHER.
THE FLOW ALOFT OVER US WILL BE WEAK.
BY THU...LOW LEVEL WINDS SHOULD PICK UP MORE OF A SRLY COMPONENT
OVER OUR REGION...AND THEREFORE DEEPER MOISTURE SHOULD BE MADE
AVAILABLE. THIS COMBINED WITH INCREASED INSTABILITY MAY YIELD THE
DEVELOPMENT OF ISOLD TSTMS IN THE SOUTH BY AFTERNOON. THE DIURNALLY-
DRIVEN CONVECTION SHOULD DISAPPEAR THU NIGHT..THEN RETURN FOR FRI
WITH SOMEWHAT BETTER COVERAGE.
IN THE SOMEWHAT DRIER AIR MID WEEK...AFTERNOON TEMPS ARE EXPECTED TO
STILL REACH ABOUT 80 TUE...CLIMBING INTO THE LOWER TO MIDDLE 80S
WITH HIGHER HUMIDITY FOR THE REST OF THE PERIOD...DEPENDING ON CLOUD
COVER. LOWS ARE EXPECTED TO RISE FROM ABOUT 60 INITIALLY TO ABOUT
65.
&&
.AVIATION...
ISSUED AT 650 AM CDT SAT MAY 30 2015
A MID/UPPER-LEVEL DISTURBANCE WILL MOVE NORTHEAST ACROSS THE
REGION TODAY. NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP AHEAD OF IT THIS AFTERNOON THROUGH EARLY THIS EVENING.
CONFIDENCE IS HIGH ENOUGH TO WARRANT A TS MENTION IN TEMPO GROUPS
AT ALL SITES. THERE COULD EASILY BE MORE THAN ONE STORM AT LEAST
IN THE VICINITY OF EACH TERMINAL.
WINDS WILL BE QUITE GUSTY THROUGH THE DAY AND EVEN THE EVENING IN
THE NORTHEAST. WINDS WILL VEER THROUGH THE PERIOD...AS A SURFACE
LOW PASSES BY TO THE NORTH OF ALL SITES...AND SURFACE HIGH
PRESSURE EVENTUALLY BUILDS IN. CEILINGS WILL DROP FROM MVFR BEHIND
THE CONVECTION TO IFR...IF NOT LIFR...OVERNIGHT.
TRIED TO ACCOUNT FOR THESE GENERAL TRENDS IN CONVECTION...WINDS
AND CEILINGS...BUT EXACT TIMING MAY VARY AT EACH SITE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...DB
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
734 AM EDT SAT MAY 30 2015
.SYNOPSIS...
THE WEEKEND WILL GET OFF TO A WARM AND HUMID START BUT A COLD
FRONT WILL DROP ACROSS THE REGION THIS EVENING AND BRING MUCH
COOLER TEMPERATURES FOR SUNDAY. THERE WILL BE WIDESPREAD SHOWERS
AND THUNDERSTORMS WITH THIS FRONT...WITH THE POTENTIAL FOR HEAVY
RAINFALL LASTING THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY WILL START OFF SIMILAR TO YESTERDAY WITH HUMID CONDITIONS
AND ABOVE NORMAL TEMPERATURES. THE CWA IS RAIN-FREE AT DAYBREAK
AND THE DEPARTURE OF A MODEST LLJ SHOULD HELP KEEP THINGS DRY FOR
THIS MORNING OUTSIDE OF AN ISOLATED SHOWER. IR SATELLITE SHOWS
SIGNIFICANT BREAKS IN CLOUD COVER AND THE PAST SEVERAL RUNS OF
THE HRRR DELAYS THE ONSET OF CONVECTION. BASED ON THESE TRENDS
HAVE LOWERED POPS LATE THIS MORNING AND AFTERNOON...AND ALSO
RAISED FORECAST MAX TEMPS WHICH SHOULD RISE WELL INTO THE 80S IN
MOST LOCATIONS.
DIURNALLY DRIVEN INSTABILITY WILL INCREASE AHEAD OF A COLD FRONT
THIS AFTERNOON. SHOWERS AND THUNDERSTORMS SHOULD FIRST DEVELOP
ACROSS INTERIOR SECTIONS WITH THE SOUTHWESTERLY FLOW HELPING KEEP
THE LAKE PLAINS BOUNDARY LAYER MIXED WHICH WILL DELAY THE
DEVELOPMENT OF ANY SHOWERS. CONVECTION WILL STILL NEED A FOCUS...AND
WITH THE FRONT STILL WELL UPSTREAM ACROSS SOUTHERN ONTARIO PROVINCE
IT WILL PROBABLY BE LAKE BREEZE OR TERRAIN BOUNDARIES THAT DO THIS.
DESPITE FAIRLY IMPRESSIVE CONSENSUS MODEL QPF...HIGH RESOLUTION
GUIDANCE (HRRR/WRF/ARW) SHOWS AREAL COVERAGE RELATIVELY SCATTERED IN
NATURE. THIS DOES NOT DIMINISH THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL. PWATS TO 1.75 INCHES AND QPF GUIDANCE SUPPORTS LOCALIZED
RAINFALL OF 1 TO 2 INCHES FROM SOME THUNDERSTORMS THIS AFTERNOON.
AREAS MOST LIKELY TO SEE THESE AMOUNTS ARE EAST OF LAKE ERIE IN
WESTERN PORTIONS OF THE SOUTHERN TIER...AND ESE OF LAKE ONTARIO FROM
WAYNE TO LEWIS COUNTIES. GIVEN THE DRY ANTECEDENT CONDITIONS AND
LOCALIZED NATURE OF HEAVY RAIN...DO NOT HAVE THE CONFIDENCE TO ISSUE
A FLOOD WATCH.
WINDS ALOFT WILL NOT BE THAT STRONG WITH 850MB WINDS ONLY ABOUT
25 KTS THIS AFTERNOON WHEN CONVECTION DEVELOPS. SPC HAS A MARGINAL
RISK FOR SEVERE WEATHER ACROSS OUR CWA AND THERE IS CHANCE FOR A
FEW STRONG TO SEVERE PULSE STORMS.
MODEL CONSENSUS BRINGS THE FRONT THROUGH THIS EVENING...WHICH WILL
BRING LARGE SCALE FORCING WHEN THE COOLER AIR UNDERCUTS THE WARM
MOIST AIRMASS. THUS THERE IS A HIGHER CONFIDENCE (NEARLY CERTAIN) IN
MEASURABLE PRECIPITATION TONIGHT WITH A WIDESPREAD SHOWERS AND SOME
EMBEDDED THUNDERSTORMS. TEMPERATURES ARE MUCH COOLER BEHIND THE
FRONT...WITH TEMPERATURES LIKELY TO FALL INTO THE UPPER 40S TO MID
50S BY DAYBREAK SUNDAY. PATCHY FOG IS ALSO POSSIBLE AS THE MOIST AIR
MASS MIXES WITH THE COOLER AIR AND GETS SQUEEZED BY THE DEVELOPING
INVERSION.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
A COMPLEX STORM AND MOISTURE LADEN STORM SYSTEM WILL CONTINUE TO
EVOLVE THROUGH THIS TIME PERIOD. ON SUNDAY THE SURFACE BAROCLINIC
BOUNDARY WILL LIE FROM NEW ENGLAND SOUTHWESTWARD ACROSS THE
SOUTHERN MID ATLANTIC STATES AND BACK TOWARDS THE MID WEST. A
SURFACE WAVE RIDING SLOWLY ALONG THIS BAROCLINIC BOUNDARY FROM THE
OHIO VALLEY WILL SEND ANOTHER WAVE OF RAINFALL ACROSS THE REGION
ON SUNDAY. PWATS SUNDAY WILL AVERAGE 1.50 TO 1.75
INCHES...INDICATING THE MOISTURE RICH ENVIRONMENT. SHARP
ISENTROPIC LIFT IN THE MID LEVELS NORTHEAST OF THE SURFACE WAVE
AND THE STILL PRESENT RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET
WILL PROVIDE FOR BROAD LIFT ACROSS THE EASTERN GREAT LAKES
REGION...WITH THIS LIFT PRODUCING A PERIOD OF RAIN SHOWERS THROUGH
THE DAY. FAVORABLE CONDITIONS FOR RAIN SHOWERS SUNDAY WILL SLOWLY
PUSH EASTWARD THROUGH THE DAY AS THE UPPER LEVEL JET AND SURFACE
WAVE SLIDE EASTWARD. BY SUNDAY NIGHT THE AREAS MOST PRONE TO RAIN
SHOWERS WILL BE CENTRAL PORTIONS OF NEW YORK STATE. HOWEVER WITH
THE SURFACE WAVE STALLING OVER PENNSYLVANIA SUNDAY NIGHT...ALL
AREAS OF THE CWA WILL HAVE AT LEAST LIKELY POPS.
INSTABILITY WILL BE MARGINAL FOR THUNDERSTORMS SUNDAY AND SUNDAY
NIGHT...WITH WHAT INSTABILITY TO BE HAD THIS DAY LYING ACROSS THE
SOUTHERN TIER. WILL PLACE THUNDER CHANCES HERE...WHILE JUST CALLING
IT PLAIN RAIN SHOWERS ACROSS THE REMAINDER OF THE REGION.
WE HAVE NOT HAD A WIDESPREAD, LONG DURATION SYNOPTIC PRECIPITATION
EVENT OF THIS MAGNITUDE IN QUITE SOME TIME. RAINFALL AMOUNTS SUNDAY
AND SUNDAY NIGHT WILL AVERAGE AROUND A HALF AN INCH OF
PRECIPITATION...WITH A FEW AREAS UPWARDS TO THREE QUARTERS OF AN
INCH. ALL TOLD BY THE END OF THE WEEKEND AN INCH TO TWO INCHES OF
RAINFALL IS LIKELY ACROSS THE CWA. WITH THE VERY DRY CONDITIONS AND
LOW CREEK AND STREAM FLOWS RIVER FLOODING IS NOT A BIG CONCERN AT
THIS POINT...AND WOULD ONLY BECOME A CONCERN IN AREAS WHERE STORMS
TRAIN AND PRODUCE LOCALLY SIGNIFICANT AMOUNTS.
BY MONDAY THE MID LEVEL SHORTWAVE WILL BE EAST OF THE REGION.
HOWEVER AT THE SURFACE A WAVE OF LOW PRESSURE WILL STILL BE NEAR THE
REGION AND WILL ADVANCE FROM WESTERN PENNSYLVANIA TOWARDS THE
EASTERN MID ATLANTIC REGION. A NORTHWEST FLOW BEHIND THIS SURFACE
LOW AND EASTERLY FLOW AHEAD OF THE SURFACE LOW WILL PROVIDE FOR
AMPLE LOW LEVEL CONVERGENCE ACROSS THE REGION. A MOISTURE RICH
ENVIRONMENT WILL REMAIN AND LIGHT RAIN SHOWERS WILL AGAIN DEVELOP
ACROSS THE EASTERN GREAT LAKES REGION ON MONDAY. THE POOR LAPSE
RATES AND LITTLE SURFACE INSTABILITY ON MONDAY WILL NOT MAKE FOR A
FAVORABLE ENVIRONMENT FOR THUNDERSTORM DEVELOPMENT.
RAIN SHOWERS MAY NOT TAPER OFF AS QUICKLY MONDAY NIGHT. THOUGH THE
SURFACE LOW WILL BE TRACKING ACROSS NEW ENGLAND MONDAY NIGHT...AND
UPPER LEVEL SHORTWAVE TROUGH WILL ADVANCE TOWARDS OUR REGION FROM
THE CENTRAL GREAT LAKES. THIS FEATURE WILL CONTINUE CHANCE POPS
ACROSS THE REGION MONDAY NIGHT.
ON TUESDAY THIS UPPER LEVEL SHORTWAVE TROUGH WILL CROSS THE EASTERN
GREAT LAKES REGION. A COLD POOL ASSOCIATED WITH THIS TROUGH WILL
INCREASE LAPSE RATES THROUGH THE DAY SUCH THAT LOW TOP SHOWERS WILL
DEVELOP THROUGH THE DAYTIME. MOISTURE WILL BE FOUND GREATEST TOWARDS
THE EAST...FROM THE GENESEE VALLEY EASTWARD THERE WILL BE A CHANCE
FOR A BRIEF SHOWER. CLOUDS WILL LIKELY START THE DAY THICK ACROSS
THE EASTERN GREAT LAKES REGION...WITH CLEARING SLOWLY EDGING
EASTWARD THROUGH THE AFTERNOON HOURS. A MUCH DRIER AIRMASS BEHIND
THIS SHORTWAVE WILL CLEAR SKIES TUESDAY NIGHT...MAKING FOR A CHILLY
NIGHT UNDER GOOD RADIATIONAL COOLING CONDITIONS.
TEMPERATURES THIS TIME PERIOD WILL AVERAGE WELL BELOW NORMAL...WITH
HIGHS SUNDAY AND MONDAY IN THE 50S. A FEW LOW 60S ARE POSSIBLE NEAR
THE STATE LINE WHERE THE SURFACE BOUNDARY MAY EDGE NORTHWARD ENOUGH
TO ALLOW FOR WARMER AIR TO REACH INTO THE SOUTHERN TIER. TUESDAY
UNDER CLOUDY SKIES AND 850 HPA TEMPERATURES OF ONLY +4 TO +5C
DAYTIME HIGHS WILL STILL REMAIN IN THE 50S TO AROUND 60. LOWS
TUESDAY NIGHT WILL DROP BACK INTO THE 40S...5 TO 10F DEGREES BELOW
NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
RIDGING ALOFT AND SURFACE HIGH PRESSURE FINALLY BUILD IN ACROSS
WESTERN NEW YORK FOR THE SECOND HALF OF THE WORK WEEK. WITH A DRIER
AIRMASS MOVING IN ON WEDNESDAY...EXPECT MOST LOCATIONS TO FINALLY
CLEAR OUT NICELY AFTER A GLOOMY START TO THE WEEK. NICE WEATHER WILL
REMAIN WITH US WEDNESDAY AND THURSDAY AS HIGH PRESSURE CROSSES THE
REGION. FRIDAY WILL BE THE NEXT CHANCE FOR SOME RAIN
SHOWERS...ALBEIT SMALL WITH A FEW THUNDERSTORMS POSSIBLY BLOSSOMING
ON A LAKE BREEZE BOUNDARY FRIDAY AFTERNOON.
TEMPERATURES WILL ALSO RECOVER THROUGH THE SECOND HALF OF THE WEEK
AS SOUTHERLY FLOW DEVELOPS ON THE BACK SIDE OF THE HIGH PRESSURE AND
WARM AIR ADVECTION PUSHES 850 MB TEMPERATURES BACK INTO THE LOW
TEENS CELSIUS ABOVE ZERO. THE WARMING TREND WILL BRING 70S BACK TO
THE FORECAST ON WEDNESDAY WITH MID 80S POSSIBLE BY FRIDAY.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
EXPECT THE VAST MAJORITY OF TIME TO BE DRY THROUGH 16Z WITH VFR
CONDITIONS. DIURNAL INSTABILITY CONVECTION WILL DEVELOP THIS
AFTERNOON...FIRST ACROSS INTERIOR SECTIONS BUT THEN BECOMING MORE
WIDESPREAD ACROSS THE ENTIRE REGION LATE AFTERNOON AND EVENING AS
A COLD FRONT APPROACHES. THIS IS LIKELY TO PRODUCE NUMEROUS
SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND INTO THIS
EVENING. THERE IS LOW FORECAST CONFIDENCE IN TIMING THE EXACT
LOCATION OF ANY STORMS. THUNDERSTORMS MAY LOWER VSBY 2SM OR LESS
IN HEAVY RAIN...AND COULD HAVE AN EXTENDED IMPACT ON FLIGHT
OPERATIONS 21Z- 03Z SUNDAY.
THE FRONT WILL DROP ACROSS THE REGION BETWEEN 03Z AND 06Z SUNDAY
WHICH WILL LOWER CIGS TO IFR OR LOWER TONIGHT FOLLOWING THE WIND
SHIFT. SHOWERS WILL LINGER OVERNIGHT WITH PERHAPS SOME EMBEDDED
TSTMS.
OUTLOOK...
SUNDAY...SHOWERS AND POSSIBLY A TSTM. IFR CIGS.
SUNDAY NIGHT AND MONDAY...MAINLY MVFR. SHOWERS LIKELY...POSSIBLY
A TSTM. TUESDAY AND WEDNESDAY...MAINLY VFR.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE AHEAD OF A COLD FRONT WITH THE
STRONGEST WINDS ACROSS THE SAINT LAWRENCE RIVER WHERE A SMALL CRAFT
ADVISORY HAS BEEN ISSUED.
BEHIND THE COLD FRONT... WINDS AND WAVES WILL INCREASE ACROSS THE
LOWER LAKES TONIGHT AND SUNDAY AS NORTH THEN NORTHEAST WINDS DEVELOP
IN A COLD AIR ADVECTION REGIME. SMALL CRAFT ADVISORIES HAVE BEEN
ISSUED FOR MOST OF THE WATERS STARTING LATE TONIGHT. WINDS WILL
DIMINISH ON MONDAY WHEN THE NORTHERLY FLOW IS EXPECTED TO DIMINISH.
&&
.CLIMATE...
MAY 2015 WILL GO DOWN AS ONE OF THE WARMEST MAYS ON RECORD...AND
POSSIBLY ONE OF THE DRIEST FOR BUFFALO AND WATERTOWN. A MOISTURE
LADEN COLD FRONT WILL CROSS THE REGION TO END THE MONTH...AND
SHOWERS AND THUNDERSTORMS ALONG THIS FEATURE MAY REMOVE CLIMATE
SITES FROM A TOP 10 DRIEST MAY`S ON RECORD. BELOW ARE THE WARMEST
MAYS ON RECORD.
BUFFALO RANK MEAN TEMPERATURE YEAR
1 64.3 1991
2 63.8 2012
3 63.4 1944
4 62.8 1998
5 62.3 2015 (THROUGH 5/29)
6 62.2 1975
ROCHESTER RANK MEAN TEMPERATURE YEAR
1 63.7 1911
2 63.6 2015 (THROUGH 5/29)
3 63.2 2012
4 63.2 1944
WATERTOWN RANK MEAN TEMPERATURE YEAR
1 60.5 2012
2 60.0 1998
3 59.3 1975
4 58.8 2015 (THROUGH 5/29)
5 58.8 1960
6 58.3 1991
MAY HAS ALSO BEEN A DRY MONTH. OUTSIDE OF A FEW LOCALIZED HEAVY
THUNDERSTORMS MANY LOCATIONS ARE WELL BELOW NORMAL FOR THE MONTH.
BELOW IS MONTHLY PRECIPITATION FOR THE DRIEST MONTHS ON RECORD FOR
OUR THREE CLIMATE SITES.
BUFFALO RANK PRECIP YEAR
1 0.53 1877
2 0.54 1934
3 0.60 2005
4 0.83 2015 (THROUGH 5/29)
5 0.90 2012
..
10 1.11 1926
ROCHESTER RANK PRECIP YEAR
1 0.24 2007
..
27 1.52 2015 (THROUGH 5/29)
28 1.55 1876
29 1.59 1954
30 1.64 1926
WATERTOWN RANK PRECIP YEAR
1 0.70 1965
2 0.87 2005
3 0.88 1980
4 0.90 1974
5 0.99 1966
6 1.04 2015 (THROUGH 5/29)
7 1.08 1972
8 1.09 1951
9 1.14 1949
10 1.16 1962
AGAIN WITH THUNDERSTORMS IN THE FORECAST TO CLOSE OUT THE MONTH
NONE OF OUR THREE CLIMATE SITES MAY HAVE A TOP TEN DRIEST MAY ON
RECORD. HOWEVER ALL THREE SITES MAY CONTINUE THE STRETCH OF BELOW
NORMAL PRECIPITATION MONTHS. BELOW ARE LISTED THE LATEST MONTH
FOR WHEN PRECIPITATION RECORDED WAS ABOVE NORMAL FOR EACH OF OUR
THREE CLIMATE LOCATIONS.
BUFFALO - OCTOBER 2014
ROCHESTER - FEBRUARY 2015
WATERTOWN - AUGUST 2014
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 8 AM EDT MONDAY FOR
LEZ040-041.
SMALL CRAFT ADVISORY FROM 2 AM SUNDAY TO 2 AM EDT
MONDAY FOR LOZ030.
SMALL CRAFT ADVISORY FROM 8 AM SUNDAY TO 8 AM EDT MONDAY
FOR LOZ042-043.
SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 5 AM EDT MONDAY
FOR LOZ044-045.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
SLZ022-024.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...THOMAS
LONG TERM...CHURCH/THOMAS
AVIATION...APFFEL
MARINE...APFFEL/THOMAS
CLIMATE...THOMAS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1001 AM EDT SAT MAY 30 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED WELL OFF THE MID ATLANTIC COAST WILL
CONTINUE TO RIDGE SOUTHWESTWARD ACROSS THE CAROLINAS THROUGH EARLY
NEXT WEEK. AN APPROACHING COLD FRONT ON MONDAY MAY STALL ACROSS
THE AREA TUESDAY...REMAINING NEARBY THROUGH FRIDAY. NEXT WEEK
THERE IS A RISK FOR SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...OVERALL SYNOPTIC PATTERN REMAINS BASICALLY
UNCHANGED FROM THE PAST SEVERAL DAYS. EXPANSIVE SURFACE HIGH
CENTERED SEVERAL HUNDRED MILES NE OF BERMUDA IS MAINTAINING A RIDGE
AXIS BACK INTO THE CAROLINAS. ALOFT...A RIDGE AXIS REMAINS OVERHEAD
WHILE JUST ONLY SLOWLY MOVING TO THE NE. THESE FEATURES TOGETHER
WILL CONTINUE THE WARM...BUT AT TIMES SHOWERY...WEATHER TODAY.
MOIST ADVECTION ON LONG E/SE FETCH IS FINALLY OVERCOMING THE
CONTINENTAL DRY AIR AND SHOWERS HAVE DEVELOPED ACROSS THE CAPE FEAR
REGION AND OVER GEORGETOWN COUNTY THIS MORNING. AS NOTED
YESTERDAY...AIR PARCELS ARE ACTUALLY ORIGINATING OVER SE CANADA
BEFORE TRAVERSING CLOCKWISE AROUND THE RIDGE AND ADVECTING BACK INTO
THE CAROLINAS. THIS IS IMPORTANT BECAUSE THE AIRMASS IS OF DRY
ORIGIN...AND THUS IT IS DIFFICULT TO CREATE WIDESPREAD CONVECTION.
HOWEVER...ENOUGH MOISTURE IS PRESENT TODAY THAT SHOWERS WILL LIKELY
BE MORE WIDESPREAD THAN PREVIOUS DAYS...BUT STILL ONLY ISOLATED TO
SCATTERED IN NATURE. THE CURRENT HRRR IS PERFORMING WELL AND IS
LEANED UPON FOR THE DAYLIGHT HOURS. SHOWERS AT THE COAST WILL BE
MOST FAVORED THIS MORNING...THEN TRENDING INLAND THROUGH THE DAY.
THIS IS DUE TO A SURGE OF DRIER AIR FORECAST BY LOWER PWATS ON
SOUNDINGS AND PLAN-VIEW GUIDANCE...AND NOTED ON WV SATELLITE...WHICH
IS PROGGED TO SHIFT WEST INTO THE AREA THIS AFTN. HAVE BUMPED POP TO
CHC...USING THE SCT WORDING HOWEVER...ALONG THE CAPE FEAR COAST THIS
MORNING...AND THEN ADDED ISOLATED TO THE REST OF THE CWA THROUGH
THIS AFTN. THE DRY PUSH SHOULD KEEP SHOWER COVERAGE TO SCATTERED AT
BEST HOWEVER...ENDING BEFORE DARK...AND NO LIGHTNING IS ANTICIPATED.
HAVE BEEN FORECASTING HIGHS TOO LOW THE PAST FEW DAYS...SO EVEN WITH
THE EASTERLY FLOW HAVE FORECAST HIGHS ABOVE THE AVAILABLE
GUIDANCE...AND AM EXPECTING 80-82 AT THE BEACHES...TO AS HIGH AS 90
FROM KINGSTREE TO BENNETTSVILLE AND LUMBERTON.
LOWS TONIGHT WILL DROP INTO THE LOW 60S...MID 60S AT THE BEACHES.
WILL NEED TO WATCH ONCE AGAIN FOR ISOLATED ADVECTION SHOWERS MOVING
ONSHORE...ESPECIALLY NEAR THE CAPE FEAR REGION...BUT FOR NOW HAVE
LEFT OUT MENTIONABLE POP FROM THE FORECAST.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...MID TO UPPER TROUGH DIGGING DOWN THROUGH
THE MISSISSIPPI VALLEY ON SUNDAY WILL MOVE EAST PUSHING A COLD
FRONT INTO THE CAROLINAS BY MONDAY. QUIET WEATHER WILL PREVAIL
AHEAD OF THIS FRONT ON SUNDAY INTO EARLY MONDAY AS HIGH PRESSURE
REMAINS DOMINANT AT THE SURFACE WITH PLENTY OF DRY AIR AND
SUBSIDENCE ALOFT. ASIDE FROM SOME DIURNAL CU AND POSSIBLE ISOLATED
SHOWER ON SUNDAY...EXPECT A VERY WARM AND MOSTLY SUNNY DAY. A
STEADY STREAM OF MOIST AIR OFF THE ATLANTIC AROUND ATLANTIC RIDGE
WILL KEEP DEWPOINT TEMPS WELL INTO THE 60S SUNDAY INTO MONDAY WITH
OVERNIGHT LOWS CLOSER TO 70 AND DAY TIME HIGHS MID HIGHS TO NEAR
90.
WINDS WILL VEER AROUND AS TROUGH DISPLACES THE HIGH FURTHER
EAST AND COLD FRONT APPROACHES FROM THE WEST. THIS WILL ALSO HELP
TO TIGHTEN THE GRADIENT A BIT THROUGH MONDAY WITH INCREASING
MOISTURE ADVECTION AS SOUTHEAST WINDS BECOME MORE
SOUTHERLY...TAPPING INTO INCREASING GULF MOISTURE. PCP WATER
VALUES DOWN CLOSER TO AN INCH SUN MORNING WILL BE 1.5 TO 1.75
INCHES BY MON AFTN INTO MON NIGHT AHEAD OF APPROACHING COLD FRONT.
THE GFS SEEMS TO BE THE MOST AGGRESSIVE WITH SHWRS/TSTMS AHEAD OF
FRONT ON MONDAY. EITHER WAY THERE WILL BE INCREASING CLOUDS ACROSS
THE AREA LATE SUNDAY THROUGH MONDAY. LOOKS LIKE BEST UPPER LEVEL
SUPPORT WILL BE WEST OF AREA ON MONDAY...AFFECTING MORE OF THE I95
CORRIDOR OR WEST. BY MONDAY AS NORTHERN STREAM TROUGH PROGRESSES
EAST...THE SOUTHERN PORTION MAY CUT OFF OVER THE GULF AS RIDGE
GETS NUDGED SOUTHEASTWARD. THIS WILL STRETCH OUT THE FRONT MORE
WEST TO EAST JUST NORTHWEST OR OVER FORECAST AREA BY TUES MORNING
AND WILL CAUSE IT TO MOVE SLOWER OR STALL. OVERALL IT LOOKS LIKE
PLENTY OF MOISTURE AND LIFT IN SOUTHERLY FLOW AHEAD OF FRONT WILL
PRODUCE MORE WIDESPREAD CONVECTION LATE MONDAY AS CAP BECOMES
ERODED...ESPECIALLY OVER WESTERN PORTION OF FORECAST AREA. ONCE
DIURNAL HEATING CUTS OFF MON EVENING SHOULD BE LEFT WITH LINGERING
SHOWERS AND CLOUDS OVER AREA THROUGH MON NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...MID TO UPPER TROUGH EXTENDING DOWN FROM
THE GREAT LAKES WILL CONTINUE TO PUSH A COLD FRONT SOUTH AND EAST
ON TUES BUT AS THE NORTHERN PORTION MOVES OFF TO THE EAST...IT MAY
CUT OFF TO THE SOUTH LEAVING FRONT STRETCHED ACROSS THE AREA FROM
W-SW TO E-NE THROUGH MID WEEK. HIGH PRESSURE WILL TRY AND BUILD
DOWN BEHIND IT FROM THE UPPER GREAT LAKES BUT DEVELOPING LOW
PRESSURE NEAR THE YUCATAN PENINSULA ON WED WILL BEGIN TO TRACK
NORTHWARD. THE LATEST GFS RUN WAS MORE AGGRESSIVE IN TERMS OF
STRENGTH AND MOVEMENT NORTHWARD...BUT EITHER WAY CLOUDS AND
SHOWERS WILL MOST LIKELY REMAIN IN FORECAST THROUGH AT LEAST
FRIDAY. DRIER HIGH PRESSURE MAY WIN OUT OVER THE AREA ON
FRIDAY...BUT GFS WOULD HAVE LOW OVER GA/SC BORDER WITH PLENTY OF
MOISTURE AND GUSTY WINDS HEADING INTO NEXT WEEKEND. FOR NOW WILL
KEEP CHC OF PCP EACH DAY WITH GREATEST CHC TUES/WED AS FRONT SAGS
OVER AREA.
CLOUDS...PCP AND SLIGHTLY COOLER NORTHERLY FLOW WILL KEEP TEMPS A
COUPLE OF DEGREES OR SO BELOW CLIMO DURING THE DAY THROUGH MOST
OF THE PERIOD....WHILE KEEPING NIGHTTIME TEMPS ON THE WARMER SIDE.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...SCT TO OCCASIONALLY BKN LOW/MID CLOUDS EXPECTED
TODAY...BUT FOR THE MOST PART CLOUD LEVELS WILL BE VFR. LIGHT
NE WINDS THIS MORNING WILL BECOME E-SE BY AFTERNOON. THERE
WILL BE ISOLATED SHOWERS...ESPECIALLY NEAR KILM THROUGH MID
MORNING BUT WILL NOT MENTION IN TAFS ATTM. THIS EVENING WINDS
WILL BECOME LIGHT AND VARIABLE. MODELS AGAIN SUGGEST MVFR CIGS
OVERNIGHT BUT CONFIDENCE IS LOW.
EXTENDED OUTLOOK...TYPICAL EARLY SUMMER PATTERN WITH MORNING MVFR
CONDITIONS WITH MAINLY AFTERNOON ISOLATED/SCATTERED SHOWERS AND
STORMS. INCREASING CHANCES FOR CONVECTION TUE AND WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...MORE OF THE SAME FOR THE MARINE COMMUNITY AS
EXPANSIVE AREA OF HIGH PRESSURE LOCATED WELL NE OF BERMUDA CONTINUES
ITS INFLUENCE LOCALLY. THE GRADIENT REMAINS PRETTY WEAK...SO E/SE
WINDS WILL CONTINUE...INCREASING FROM 5-10 KTS THIS MORNING TO 10-15
KTS THROUGH THE AFTN AND EARLY TONIGHT. A RETURN TO 5-10 KTS IS
FORECAST LATE. THE WAVE SPECTRUM WILL BE NEARLY ENTIRELY SWELL
DOMINATED...AS A 4 FT AT 9 SEC EASTERLY SWELL PERSISTS...PUSHING
WAVE HEIGHTS TO 2-4 FT THROUGH THE PERIOD.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...SE WIND EARLY SUNDAY WILL BECOME MORE
SOUTHERLY LATE SUN AND SUN NIGHT AS HIGH PRESSURE EXTENDING IN
FROM THE ATLANTIC BEGINS TO RETREAT. THE PERSISTENT SOUTHERLY PUSH
WILL KEEP SEAS 2 TO 4 FT THROUGH EARLY NEXT WEEK. A COLD FRONT
WILL APPROACH THE WATERS HEADING INTO TUES WHICH WILL HELP TO VEER
WINDS AROUND TO THE S-SW AND INCREASE SLIGHTLY FROM LESS THAN 10
KTS SUN INTO MON UP TO AROUND 10 KTS OR SO BY TUES MORNING. THE
LONGER PERIOD EASTERLY FETCH WITH A PERIOD UP TO 9 SECONDS WILL
COMBINE A SHORTER PERIOD WIND WAVE.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...WINDS WILL CONTINUE TO VEER AROUND TUES
INTO WED AS COLD FRONT LAYS DOWN ACROSS THE WATERS AND STALLS
THROUGH MID WEEK. THIS WILL SHIFT THE WINDS TO EASTERLY AND
EVENTUALLY NORTHEAST. WINDS MAY BECOME VARIABLE DEPENDING WHERE
FRONT STALLS WITH N-NE WINDS ON NORTH SIDE OF FRONT AND S-SE
WINDS ON SOUTH SIDE. WINDS WILL REMAIN 10 KTS OR LESS THROUGH MOST
OF THE PERIOD WITH SEAS 3 FT OR LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$ SYNOPSIS...RGZ
NEAR TERM...JDW
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR
MARINE...JDW/RGZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
924 AM EDT SAT MAY 30 2015
.SYNOPSIS...
MOISTURE ASSOCIATED WITH LOW PRESSURE AND A SLOW MOVING COLD FRONT
WILL BRING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS TODAY
THROUGH SUNDAY. HIGH PRESSURE WILL BRING COOLER AND DRIER AIR FOR
THE BEGINNING OF THE WORK WEEK. WARMER TEMPERATURES WILL RETURN
LATER NEXT WEEK AS THE HIGH TRAVELS SLOWLY EASTWARD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST KILN SOUNDING SHOWING A PRETTY MOIST ENVIRONMENT OUT THERE
WITH PWATS AT 1.50" (NORMAL JUST ABOVE 1" FOR THIS TIME OF YEAR).
K INDEX WAS ALSO 35. HIGH RES MODELS ARE A BIT OVERDONE THIS
MORNING. LATEST HRRR DIDN`T INITIALIZE WELL WITH LATEST RAP
OVERDONE. THE NCEP WRF AND NSSL WRF SEEM TO BE DOING A GOOD JOB SO
FAR WITH MORNING RAIN AND SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS FORMING THIS AFTERNOON. HAVE PUSHED HIGHER POPS MORE
TOWARDS THIS AFTERNOON AND INCREASED POPS TO AT LEAST CHANCE
ACROSS THE AREA BY LATER AFTERNOON. THIS IS SUPPORTED BY 12Z KILN
SOUNDING DATA ALONG WITH HIGH RES MODELS. A FEW THUNDERSTORMS
COULD BE STRONG THIS AFTERNOON BUT LOWER INSTABILITY AND WIND SHEAR
SHOULD KEEP THE SEVERE POTENTIAL LIMITED. HIGHS IN THE LOWER TO
MID 80S STILL LOOK ON TRACK WITH 850 TEMPS VERY SIMILAR TO
YESTERDAY.
PREV DISCUSSION->
AREA IS IN A PERSISTENTLY HUMID SOUTHERLY FLOW BETWEEN HIGH
PRESSURE CENTERED TO THE EAST AND A LOW PRESSURE SYSTEM TO THE
WEST. ISOLATED SHOWERS HAVE DISSIPATED EARLY THIS MORNING LEAVING
PARTLY TO MOSTLY CLOUDY SKIES. LATEST RAP SHOWS PRECIP DEVELOPING
WITHIN THE NEXT COUPLE OF HOURS BUT THIS APPEARS OVERDONE. WILL
CONTINUE TO MONITOR.
A SURFACE LOW FORMING OVER MISSOURI AT THE TAIL END OF A COLD
FRONT WILL MOVE TO ILLINOIS THIS AFTERNOON. EXPECT SHOWERS AND
THUNDERSTORMS TO REDEVELOP TODAY AS INSTABILITY AND FORCING
INCREASES AHEAD OF THE LOW...ESPECIALLY THIS AFTERNOON DURING PEAK
HEATING. BEST CHANCE FOR CONVECTIVE DEVELOPMENT WILL BE IN
NORTHWEST COUNTIES CLOSER TO THE AXIS OF AN UPPER TROUGH CENTERED
OVER THE MISSISSIPPI VALLEY. A FEW STRONG THUNDERSTORMS WILL BE
POSSIBLE THIS AFTERNOON BUT RATHER WEAK INSTABILITY AND WIND SHEAR
WILL LIMIT SEVERE POTENTIAL.
HIGH TEMPERATURES WILL REACH THE LOWER TO MIDDLE 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THERE MAY BE A TEMPORARY LULL IN CONVECTION THIS EVENING WITH LOSS
OF DAYTIME HEATING. BY LATER TONIGHT...SURFACE LOW PRESSURE PUSHED
TO OHIO BY THE UPPER TROUGH WILL PRODUCE A NOTABLE INCREASE IN
FORCING. SHOWERS AND THUNDERSTORMS ARE A NEAR CERTAINTY IN
NORTHERN COUNTIES THAT WILL BE ON THE NORTH SIDE OF THE LOW TRACK. A
POTENT LOW LEVEL JET...COPIOUS MOISTURE AND A BAND OF DEFORMATION
WILL ALL COME INTO PLAY TO PRODUCE PERHAPS AS MUCH AS TWO INCHES
OF RAIN IN NORTHERN LOCATIONS. RAIN CHANCES WILL DECREASE TOWARD
THE SOUTH AWAY FROM THE MOST FAVORABLE FORCING.
WIDESPREAD SHOWERS WILL DIMINISH SUNDAY AS THE LOW MOVES EAST AND
THE LOW LEVEL FLOW BECOMES NORTHWEST. THUNDERSTORMS WILL BE LESS
EVIDENT ON SUNDAY IN A REGIME OF DECREASING INSTABILITY. HIGH
PRESSURE AND A DRY AIRMASS WILL MOVE IN MONDAY ON A NORTHWEST
FLOW ALOFT.
THE NORTHERLY LOW LEVEL FLOW BEHIND THE LOW WILL BRING COOLER
TEMPERATURES. HIGHS ON SUNDAY WILL VARY FROM THE LOW 60S NORTHWEST
UP TO THE UPPER 70S SOUTHEAST. HIGHS IN THE 60S ARE EXPECTED IN
MOST LOCATIONS ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
FORECAST HAS SHIFTED IN TIMING RETURN FLOW TO THE OHIO VALLEY. A
SLOWER SHIFT OF WINDS IN THE TUES-THURS TIME FRAME FROM EAST TO
EVENTUALLY SOUTH HAS HELPED KEEP A DRIER AND COOLER FORECAST FOR THE
BETTER PART OF NEXT WEEK.
A LARGE AREA OF HIGH PRESSURE NORTH OF THE GREAT LAKES REGION WILL
EXTEND A RIDGE SOUTHWEST INTO THE NORTHERN OHIO VALLEY TUESDAY THROUGH
WEDNESDAY. THE HIGH WILL SETTLE IN THE OHIO VALLEY ON WEDNESDAY
AND THEN MEANDER EASTWARD OVERNIGHT AND THURSDAY.
WITH THE NORTHEAST TO EAST WINDS HOLDING SWAY OVER THE REGION
THROUGH THIS TIME...HAVE REMOVED POPS UNTIL THURS AFTERNOON WHEN
SOME RETURN TO SOUTHERLY FLOW AND INCREASED MOISTURE WOULD BE
EXPECTED. TEMPS THROUGH THIS TIME WILL BE BELOW NORMAL...STARTING
WITH HIGHS IN THE UPPER 60S TO LOW 70S MONDAY RISING TO AROUND 80
WEDNESDAY AND LOW TO MID 80S FOR THE END OF THE WEEK. DRIER AIR WILL
PERMIT LOWS TO DIP INTO THE 50S MON NIGHT AND INCREASE TO AROUND 60
WED NIGHT...JUMPING TO THE MID 60S WHEN THE FLOW TURNS SOUTH AND
MOISTURE INCREASES LATE IN THE FORECAST.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
A COUPLE OF SHOWERS HAVE DEVELOPED EARLY THIS MORNING...AFFECTING
ILN AND IF THEY HOLD TOGETHER COULD MOVE TOWARD CMH. WILL LIKELY HAVE
VCSH IN ATTM THROUGH 14Z-15Z. OTHERWISE...PREVAILING VFR THIS
MORNING. SCATTERED SHOWERS AND THUNDERSTORMS ARE THEN EXPECTED
THIS AFTERNOON/EARLY EVENING...CONTINUE VCTS IN TAFS. IT LOOKS
LIKE MOST OF THE MID TO LATE EVENING SHOWER/THUNDERSTORM ACTIVITY
WILL RESIDE JUST NORTHWEST OF THE TERMINALS CLOSER TO A FRONT/LOW
PRESSURE...BUT CHANCES WILL START TO INCREASE AGAIN AFT 06Z. SOME
GUIDANCE ALSO SUGGESTS LOWERING CIGS TO AT LEAST MVFR. CONFIDENCE
IS LOW...AND KEPT CIGS IN VFR ATTM.
OUTLOOK...SHOWERS AND THUNDERSTORMS ARE POSSIBLE SUNDAY.
POTENTIAL EXISTS FOR MVFR OR IFR CIGS LATE SUNDAY THROUGH MONDAY
MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO/HAINES
NEAR TERM...CONIGLIO/HAINES
SHORT TERM...CONIGLIO
LONG TERM...FRANKS
AVIATION...BPP
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
652 AM EDT SAT MAY 30 2015
.SYNOPSIS...
MOISTURE ASSOCIATED WITH LOW PRESSURE AND A SLOW MOVING COLD FRONT
WILL BRING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS TODAY
THROUGH SUNDAY. HIGH PRESSURE WILL BRING COOLER AND DRIER AIR FOR
THE BEGINNING OF THE WORK WEEK. WARMER TEMPERATURES WILL RETURN
LATER NEXT WEEK AS THE HIGH TRAVELS SLOWLY EASTWARD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AREA IS IN A PERSISTENTLY HUMID SOUTHERLY FLOW BETWEEN HIGH
PRESSURE CENTERED TO THE EAST AND A LOW PRESSURE SYSTEM TO THE
WEST. ISOLATED SHOWERS HAVE DISSIPATED EARLY THIS MORNING LEAVING
PARTLY TO MOSTLY CLOUDY SKIES. LATEST RAP SHOWS PRECIP DEVELOPING
WITHIN THE NEXT COUPLE OF HOURS BUT THIS APPEARS OVERDONE. WILL
CONTINUE TO MONITOR.
A SURFACE LOW FORMING OVER MISSOURI AT THE TAIL END OF A COLD
FRONT WILL MOVE TO ILLINOIS THIS AFTERNOON. EXPECT SHOWERS AND
THUNDERSTORMS TO REDEVELOP TODAY AS INSTABILITY AND FORCING
INCREASES AHEAD OF THE LOW...ESPECIALLY THIS AFTERNOON DURING PEAK
HEATING. BEST CHANCE FOR CONVECTIVE DEVELOPMENT WILL BE IN
NORTHWEST COUNTIES CLOSER TO THE AXIS OF AN UPPER TROUGH CENTERED
OVER THE MISSISSIPPI VALLEY. A FEW STRONG THUNDERSTORMS WILL BE
POSSIBLE THIS AFTERNOON BUT RATHER WEAK INSTABILITY AND WIND SHEAR
WILL LIMIT SEVERE POTENTIAL.
HIGH TEMPERATURES WILL REACH THE LOWER TO MIDDLE 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THERE MAY BE A TEMPORARY LULL IN CONVECTION THIS EVENING WITH LOSS
OF DAYTIME HEATING. BY LATER TONIGHT...SURFACE LOW PRESSURE PUSHED
TO OHIO BY THE UPPER TROUGH WILL PRODUCE A NOTABLE INCREASE IN
FORCING. SHOWERS AND THUNDERSTORMS ARE A NEAR CERTAINTY IN
NORTHERN COUNTIES THAT WILL BE ON THE NORTH SIDE OF THE LOW TRACK. A
POTENT LOW LEVEL JET...COPIOUS MOISTURE AND A BAND OF DEFORMATION
WILL ALL COME INTO PLAY TO PRODUCE PERHAPS AS MUCH AS TWO INCHES
OF RAIN IN NORTHERN LOCATIONS. RAIN CHANCES WILL DECREASE TOWARD
THE SOUTH AWAY FROM THE MOST FAVORABLE FORCING.
WIDESPREAD SHOWERS WILL DIMINISH SUNDAY AS THE LOW MOVES EAST AND
THE LOW LEVEL FLOW BECOMES NORTHWEST. THUNDERSTORMS WILL BE LESS
EVIDENT ON SUNDAY IN A REGIME OF DECREASING INSTABILITY. HIGH
PRESSURE AND A DRY AIRMASS WILL MOVE IN MONDAY ON A NORTHWEST
FLOW ALOFT.
THE NORTHERLY LOW LEVEL FLOW BEHIND THE LOW WILL BRING COOLER
TEMPERATURES. HIGHS ON SUNDAY WILL VARY FROM THE LOW 60S NORTHWEST
UP TO THE UPPER 70S SOUTHEAST. HIGHS IN THE 60S ARE EXPECTED IN
MOST LOCATIONS ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
FORECAST HAS SHIFTED IN TIMING RETURN FLOW TO THE OHIO VALLEY. A
SLOWER SHIFT OF WINDS IN THE TUES-THURS TIME FRAME FROM EAST TO
EVENTUALLY SOUTH HAS HELPED KEEP A DRIER AND COOLER FORECAST FOR THE
BETTER PART OF NEXT WEEK.
A LARGE AREA OF HIGH PRESSURE NORTH OF THE GREAT LAKES REGION WILL
EXTEND A RIDGE SOUTHWEST INTO THE NORTHERN OHIO VALLEY TUESDAY THROUGH
WEDNESDAY. THE HIGH WILL SETTLE IN THE OHIO VALLEY ON WEDNESDAY
AND THEN MEANDER EASTWARD OVERNIGHT AND THURSDAY.
WITH THE NORTHEAST TO EAST WINDS HOLDING SWAY OVER THE REGION
THROUGH THIS TIME...HAVE REMOVED POPS UNTIL THURS AFTERNOON WHEN
SOME RETURN TO SOUTHERLY FLOW AND INCREASED MOISTURE WOULD BE
EXPECTED. TEMPS THROUGH THIS TIME WILL BE BELOW NORMAL...STARTING
WITH HIGHS IN THE UPPER 60S TO LOW 70S MONDAY RISING TO AROUND 80
WEDNESDAY AND LOW TO MID 80S FOR THE END OF THE WEEK. DRIER AIR WILL
PERMIT LOWS TO DIP INTO THE 50S MON NIGHT AND INCREASE TO AROUND 60
WED NIGHT...JUMPING TO THE MID 60S WHEN THE FLOW TURNS SOUTH AND
MOISTURE INCREASES LATE IN THE FORECAST.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A COUPLE OF SHOWERS HAVE DEVELOPED EARLY THIS MORNING...AFFECTING
ILN AND IF THEY HOLD TOGETHER COULD MOVE TOWARD CMH. WILL LIKELY HAVE
VCSH IN ATTM THROUGH 14Z-15Z. OTHERWISE...PREVAILING VFR THIS
MORNING. SCATTERED SHOWERS AND THUNDERSTORMS ARE THEN EXPECTED
THIS AFTERNOON/EARLY EVENING...CONTINUE VCTS IN TAFS. IT LOOKS
LIKE MOST OF THE MID TO LATE EVENING SHOWER/THUNDERSTORM ACTIVITY
WILL RESIDE JUST NORTHWEST OF THE TERMINALS CLOSER TO A FRONT/LOW
PRESSURE...BUT CHANCES WILL START TO INCREASE AGAIN AFT 06Z. SOME
GUIDANCE ALSO SUGGESTS LOWERING CIGS TO AT LEAST MVFR. CONFIDENCE
IS LOW...AND KEPT CIGS IN VFR ATTM.
OUTLOOK...SHOWERS AND THUNDERSTORMS ARE POSSIBLE SUNDAY.
POTENTIAL EXISTS FOR MVFR OR IFR CIGS LATE SUNDAY THROUGH MONDAY
MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...CONIGLIO
SHORT TERM...CONIGLIO
LONG TERM...FRANKS
AVIATION...BPP
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
850 AM CDT SAT MAY 30 2015
.UPDATE...
UPDATED FOR A SLIGHT REDUCTION OF POPS IN THE DELTA THIS MORNING.
&&
.DISCUSSION...
WATER VAPOR IMAGERY SHOWING MCV ROTATING NORTHEASTWARD ACROSS
ARKANSAS THIS MORNING...WITH RADAR INDICATING A BETTER
CONCENTRATION OF MEASURABLE RAINFALL NEAR THE CENTER AND AN ILL-
DEFINED DRY SLOT ROTATING UP ALONG THE SOUTHWEST DELTA COUNTIES.
HAVE REDUCED POPS IN THIS LATTER REGION TO INCLUDE THE MEMPHIS
METRO THROUGH NOON. AFTER WHICH...THE BRUNT OF THE STORMS WILL RUN
EAST OF A UNION CITY TENNESSEE...TO AN OXFORD MISSISSIPPI
LINE...WITH THE BEST THREAT FOR A SEVERE STORM RUNNING ACROSS THE
NORTHEAST COUNTIES ALONG THE LOWER TENNESSEE RIVER VALLEY.
THE REMAINDER OF THE MORNING FORECAST APPEARS TO BE ON TRACK.
JAB
&&
.PREV DISCUSSION... /ISSUED 616 AM CDT SAT MAY 30 2015/
DISCUSSION... /ISSUED 424 AM CDT SAT MAY 30 2015/
EARLY MORNING GOES WATER VAPOR IMAGERY SHOWED A WELL DEFINED
UPPER LEVEL SHORTWAVE CENTERED JUST SOUTH OF FORT SMITH
AR...MOVING EAST. NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS WERE
SPREADING NORTHEAST THROUGH EASTERN AR AHEAD OF THIS FEATURE.
SHOWERS AND THUNDERSTORMS WILL LIKELY SPREAD EAST THROUGH MOST OF
THE MIDSOUTH THIS MORNING. 07Z HRRR MODEL SHOWS BEST RAIN CHANCES
SHIFTING TO NORTHEAST MS AND AREAS OF WEST TN NEAR THE TN RIVER BY
MIDAFTERNOON. A FEW WRAP AROUND SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE FURTHER WEST...ALONG AND BEHIND A SURFACE COLD FRONT. ANY
WRAP AROUND SHOWERS SHOULD DISSIPATE THIS EVENING... AS THE
SHORTWAVE LIFTS OUT AND DAYTIME HEATING ENDS.
A SECONDARY SHORTWAVE WILL DROP FROM THE OZARKS INTO THE MIDSOUTH
ON SUNDAY...WITH NORTHEAST MS BEST POSITIONED TO RECEIVE
MEASURABLE RAINFALL. THIS SECONDARY SHORTWAVE WILL EXIT SUNDAY
EVENING... LEAVING DRIER DEEP NORTHWEST FLOW PREVAILING OVER ALL
OF THE MIDSOUTH BY SUNDAY NIGHT.
THE MONDAY THROUGH WEDNESDAY PERIODS APPEAR DRIER THAN EARLIER
FORECAST...WITH WEAKENING NORTHWEST FLOW ALOFT GIVING WAY TO
AN ENCROACHING UPPER LEVEL RIDGE FROM THE SOUTHERN PLAINS. THE
GFS AND ECMWF MODELS CONTINUE TO SHOW DIFFERING SOLUTIONS TO A
DEVELOPING CUTOFF LOW OVER THE SOUTHEAST STATES. NEITHER MODEL
RETROGRADES THE UPPER LOW SUFFICIENTLY TO BRING APPRECIABLE RAIN
CHANCES TO THE MIDSOUTH UNTIL LATER IN THE WEEK...AND ONLY THE GFS
SHOWS THIS SCENARIO. IF THE ECMWF VERIFIES...WE MAY SEE LOWER 90S
OVER MUCH OF THE MIDSOUTH LATE IN THE WEEK. FOR NOW...HAVE KEPT
THE EXTENDED FORECAST HIGHS NEAR THE MODEL ENSEMBLE AVERAGE...BUT
THERE MAY BE A WARMER TREND DEVELOPING FOR LATER NEXT WEEK.
PWB
&&
.AVIATION...
12Z TAF SET
SCATTERED TO NUMEROUS SHRAS/TSRAS WILL OCCUR TODAY ACROSS THE
MIDSOUTH AHEAD OF A COLD FRONT. VSBYS AND CIGS WILL BE REDUCED IN
THE HEAVIER CONVECTION. AFTER 00Z...EXPECT THE FRONT TO BE LOCATED
ROUGHLY NEAR THE MS/TN BORDER THUS REDEVELOPMENT OF CONVECTION MAY
OCCUR DURING THE EVENING ALONG AND AHEAD OF THE FRONT. WENT AHEAD
AND KEPT VCTS WORDING THROUGH ENTIRE TAF PERIOD AT KTUP. AT KMEM
ENDED THREAT AT 9Z. POST-FRONTAL MVFR CIGS...POSSIBLY LOWER...WILL
IMPACT KJBR...KMKL AND KMEM AFTER 8-9Z. GUSTY SSW WINDS EXPECTED
TODAY AHEAD OF FRONT. WINDS WILL BECOME NW AT 5-8 KTS BEHIND
FRONT.
KRM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
616 AM CDT SAT MAY 30 2015
.DISCUSSION... /ISSUED 424 AM CDT SAT MAY 30 2015/
EARLY MORNING GOES WATER VAPOR IMAGERY SHOWED A WELL DEFINED
UPPER LEVEL SHORTWAVE CENTERED JUST SOUTH OF FORT SMITH
AR...MOVING EAST. NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS WERE
SPREADING NORTHEAST THROUGH EASTERN AR AHEAD OF THIS FEATURE.
SHOWERS AND THUNDERSTORMS WILL LIKELY SPREAD EAST THROUGH MOST OF
THE MIDSOUTH THIS MORNING. 07Z HRRR MODEL SHOWS BEST RAIN CHANCES
SHIFTING TO NORTHEAST MS AND AREAS OF WEST TN NEAR THE TN RIVER BY
MIDAFTERNOON. A FEW WRAP AROUND SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE FURTHER WEST...ALONG AND BEHIND A SURFACE COLD FRONT. ANY
WRAP AROUND SHOWERS SHOULD DISSIPATE THIS EVENING... AS THE
SHORTWAVE LIFTS OUT AND DAYTIME HEATING ENDS.
A SECONDARY SHORTWAVE WILL DROP FROM THE OZARKS INTO THE MIDSOUTH
ON SUNDAY...WITH NORTHEAST MS BEST POSITIONED TO RECEIVE
MEASURABLE RAINFALL. THIS SECONDARY SHORTWAVE WILL EXIT SUNDAY
EVENING... LEAVING DRIER DEEP NORTHWEST FLOW PREVAILING OVER ALL
OF THE MIDSOUTH BY SUNDAY NIGHT.
THE MONDAY THROUGH WEDNESDAY PERIODS APPEAR DRIER THAN EARLIER
FORECAST...WITH WEAKENING NORTHWEST FLOW ALOFT GIVING WAY TO
AN ENCROACHING UPPER LEVEL RIDGE FROM THE SOUTHERN PLAINS. THE
GFS AND ECMWF MODELS CONTINUE TO SHOW DIFFERING SOLUTIONS TO A
DEVELOPING CUTOFF LOW OVER THE SOUTHEAST STATES. NEITHER MODEL
RETROGRADES THE UPPER LOW SUFFICIENTLY TO BRING APPRECIABLE RAIN
CHANCES TO THE MIDSOUTH UNTIL LATER IN THE WEEK...AND ONLY THE GFS
SHOWS THIS SCENARIO. IF THE ECMWF VERIFIES...WE MAY SEE LOWER 90S
OVER MUCH OF THE MIDSOUTH LATE IN THE WEEK. FOR NOW...HAVE KEPT
THE EXTENDED FORECAST HIGHS NEAR THE MODEL ENSEMBLE AVERAGE...BUT
THERE MAY BE A WARMER TREND DEVELOPING FOR LATER NEXT WEEK.
PWB
&&
.AVIATION...
12Z TAF SET
SCATTERED TO NUMEROUS SHRAS/TSRAS WILL OCCUR TODAY ACROSS THE
MIDSOUTH AHEAD OF A COLD FRONT. VSBYS AND CIGS WILL BE REDUCED IN
THE HEAVIER CONVECTION. AFTER 00Z...EXPECT THE FRONT TO BE LOCATED
ROUGHLY NEAR THE MS/TN BORDER THUS REDEVELOPMENT OF CONVECTION MAY
OCCUR DURING THE EVENING ALONG AND AHEAD OF THE FRONT. WENT AHEAD
AND KEPT VCTS WORDING THROUGH ENTIRE TAF PERIOD AT KTUP. AT KMEM
ENDED THREAT AT 9Z. POST-FRONTAL MVFR CIGS...POSSIBLY LOWER...WILL
IMPACT KJBR...KMKL AND KMEM AFTER 8-9Z. GUSTY SSW WINDS EXPECTED
TODAY AHEAD OF FRONT. WINDS WILL BECOME NW AT 5-8 KTS BEHIND
FRONT.
KRM
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1056 AM CDT SAT MAY 30 2015
.DISCUSSION...
OUTFLOW BOUNDARY HAS PUSHED INTO SE TX FROM CONVECTION OVER N TX
THIS MORNING. THIS ALONG WITH DIURNAL HEATING HAVE ALLOWED FOR A
FEW SCT SHOWERS AND STORMS TO FORM MAINLY ALONG US 59 FROM HOUSTON
TO LUFKIN. OTHER ISO COVECTIVE CELLS HAVE FORMED FROM COLUMBUS TO
PALACIOS. MOST OF THIS ACTIVITY SEEMS TO PULSE IN INTENSITY WITH
MAYBE RAIN RATES OF HALF INCH AN HOUR. THE MAIN TREND TO NOTE IS
THAT STORMS ARE NOT MOVING VERY MUCH. LATEST SFC ANALYSIS HAS COLD
FRONT PUSHING THROUGH N TX INTO W C TX. FRONT SHOULD BE MAKING ITS
WAY TO SE TX THIS AFTERNOON. BEGINNING OF THE FRONT SHOULD REACH
COLLEGE STATION/CROCKETT LINE 3-4PM AND THEN HOUSTON AREA 6-7PM
BASED ON LATEST HRRR RUN.
LATEST SHORT RANGE GUIDANCE STILL HAS STORMS FORMING ON SEA
BREEZE EARLY AFTERNOON AND THEN ALONG THE FRONT LATER THIS
AFTERNOON. MAIN CONCERN WILL BE FOR HEAVY RAINFALL AS STORMS WILL
NOT BE MOVING QUIKCLY. RAIN RATES OF 1-2 INCHES FOR A COUPLE OF
HRS WILL CAUSE FLOODING PROBLEMS. WE ARE STILL LOOKING AT VERY
SATURATED GROUNDS WHICH MEANS EVEN 2-3 INCHES OF RAIN COULD CAUSE
FLOODING PROBLEMS. FOR NOW WE WILL KEEP FLASH FLOOD WATCH AS IS
BUT WILL EVALUATE THE NEED FOR A WATCH FOR SOME OF THE NORTHERN
PORTIONS OF THE FORECAST AREA DEPENDING ON THE EVOLUTION OF
CONVECTION.
39
&&
.PREV DISCUSSION... /ISSUED 628 AM CDT SAT MAY 30 2015/
DISCUSSION...
SEE THE 12Z AVIATION DISCUSSION BELOW.
40
AVIATION...
THE SQUALL LINE OVER THE HILL COUNTRY MAY HOLD TOGETHER TO AFFECT
KCLL AND KUTS BEFORE 15Z. THE LATEST HIGH RES MODELS ARE HOLDING
BACK ON THUNDERSTORM CHANCES AT THESE TWO SITES UNTIL MID MORNING.
THIS MAY PAN OUT AS THE LATEST RADAR INDICATES THAT THE SQUALL
LINE WAS WEAKENING AT 11Z AS IT WAS MOVING TOWARD THE KGRK RADAR
SITE. WILL UPDATE THE FORECAST FOR THESE LOCATIONS IF THESE STORMS
HOLD TOGETHER.
KEPT THE SAME TIMING FOR THE MOST PART AS IN THE LAST FORECAST
PACKAGE. BY MID MORNING BETTER CHANCES FOR SHOWERS WILL DEVELOP
AND BY MIDDAY THUNDERSTORM CHANCES WILL BECOME BETTER. THERE ARE
SOME INDICATIONS THAT THE STORMS MOVING IN FROM THE NORTHWEST WILL
MERGE WITH SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE
SEABREEZE. IF SO...THE HOUSTON METRO AIRPORTS MAY HAVE ADVERSE
IMPACTS FROM THUNDERSTORMS FROM 18Z TO 03Z. AFTER A BREAK...THE
NAM12 BRINGS ANOTHER CHANCE FOR THUNDERSTORMS FROM KCXO TO THE
COAST AFTER 09Z.
40
PREV DISCUSSION... /ISSUED 400 AM CDT SAT MAY 30 2015/
DISCUSSION...
AT 3 AM...A COLD FRONT EXTENDED FROM ABOUT OKLAHOMA CITY TO
ABILENE TO FORT STOCKTON. SHRA/TSRA CONTINUE TO DEVELOP ALONG THE
FRONT AS IT SURGES SOUTH...AND PUSHES EAST A BIT MORE SLOWLY.
SATELLITE DERIVED PW VALUES SHOW 1.6-1.9 INCHES ACROSS SOUTHEAST
TEXAS. FCST SOUNDINGS SHOW CONVECTIVE TEMPS AROUND 82 DEGREES.
UPPER LEVEL WINDS ARE BROADLY DIVERGENT AND ARE PROGGED TO REMAIN
DIVERGENT THROUGH SUNDAY MORNING. SE TX WILL BRIEFLY LIE IN A
RIGHT REAR QUAD SATURDAY NIGHT. SHRA/TSRA WILL BEGIN TO DEVELOP
ALONG THE COAST BETWEEN 15-17Z AS TEMPS WARM INTO THE LOWER 80S.
THE COLD FRONT OVER NORTH TEXAS WILL BE PUSHING SOUTH AND EAST AND
WILL REACH THE NORTHERN ZONES ABOUT 18Z. THE SEA BREEZE WILL BEGIN
TO WORK INLAND DURING THE AFTN AS THE FRONT CONTINUES TO PUSH
SOUTH AND THE TWO FEATURES SHOULD MERGE OVER SE TX DURING THE
AFTN. THE NAM 12 IS VERY AGGRESSIVE WITH THE SEA BREEZE/FRONT
COLLIDING AROUND 21Z WITH VERY HEAVY RAIN DEVELOPING ALONG THE
U.S. HIGHWAY 59 CORRIDOR. THE NAM IS PRODUCING 3-4 INCHES OF RAIN
ACROSS HARRIS...BRAZORIA AND FT BEND COUNTIES. THE QPF OUTPUT FROM
THE GFS AND ECMWF ARE MORE BENIGN BUT THEY ARE BASICALLY ON THE
SAME PAGE WITH A WEAK SEA BREEZE MERGING WITH THE COLD FRONT. WILL
MAINTAIN THE FLASH FLOOD WATCH AS IS BUT FEEL THE THREAT FOR
EXCESSIVE RAIN WILL FOCUS OVER THE CENTRAL ZONES. THINK THE WATCH
WILL BE TRIMMED FROM THE NORTH TOWARD EVENING ONCE CONVECTIVE
TRENDS BECOME CLEAR.
THE FRONT WILL MEANDER OVER THE SOUTHERN HALF OF SOUTHEAST TEXAS
THROUGH EARLY SUNDAY MORNING. THE COMBINATION OF THE FRONT AND A
TROUGH AT 500 MB WILL LEAD TO ADDITIONAL SHOWERS OVERNIGHT INTO
SUNDAY. DRIER AIR WILL WORK INTO THE AREA SUNDAY AFTERNOON AND
RAIN CHANCES WILL DECREASE DURING THE AFTN.
THE UPPER LEVEL TROUGH WILL PUSH EAST ON MONDAY BUT IT LOOKS
CLOSE ENOUGH TO STILL TRIGGER A FEW AFTN SHRA/TSRA OVER THE
EASTERN ZONES ON MON. UPPER LEVEL RIDGING WILL BUILD ACROSS SOUTH
TEXAS TUE-FRI. SUBSIDENCE FROM THE RIDGE SHOULD LIMIT RAIN CHANCES
AND ALLOW TEMPS TO WARM TO NEAR 90 DEGREES BY THE END OF NEXT
WEEK. 43
MARINE...
WINDS AND SEAS MAY BRIEFLY GET TO ABOVE CAUTION LEVELS WITH
THUNDERSTORMS LATER TODAY AND TONIGHT. A FRONTAL BOUNDARY IS
FORECAST BY THE MODELS TO MOVE OFF THE COAST LATER TONIGHT OR ON
SUNDAY. THE FRONT IS THEN FORECAST TO DISSIPATE AS HIGH PRESSURE
BUILDS INTO THE NORTHWESTERN GULF INTO THE MID WEEK PERIOD.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 85 67 81 64 85 / 70 50 30 10 20
HOUSTON (IAH) 87 70 83 66 87 / 80 70 50 20 30
GALVESTON (GLS) 85 75 81 74 81 / 50 50 50 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
934 AM CDT SAT MAY 30 2015
.UPDATE...
CURRENT CONDITIONS ACROSS THE AREA SHOW AN OUTFLOW BOUNDARY FROM
UVALDE TO SAN ANTONIO TO LA GRANGE LEFT OVER FROM THE LINE OF
STORMS THAT PUSHED THROUGH THIS MORNING. BEHIND THIS LINE SKIES
HAVE CLEARED OUR ALLOWING TEMPERATURES TO WARM. ACROSS THE WEST
THE NEXT LINE OF SHOWERS AND THUNDERSTORMS IS PUSHING INTO VAL
VERDE COUNTY.
HAVE ADJUSTED THE POPS/QPF/WEATHER GRIDS TO FOCUS THE HIGHEST
CHANCES OF PRECIPITATION ACROSS THE WEST THIS MORNING WITH THIS
LINE. RECENT RUNS OF THE HRRR TAKE THIS COMPLEX TO THE SOUTHEAST
ALONG THE RIO GRANDE RIVER AND THE RIO GRANDE PLAINS. THE MAIN
THREATS WILL BE BRIEF GUSTY WINDS UP TO 40 MPH AND SOME SMALL
HAIL. BRIEF HEAVY RAINFALL WILL ALSO BE POSSIBLE AS THIS LINE
RACES TO THE SOUTHEAST.
THE HIGH RESOLUTION MODELS THEN DEVELOP MORE SHOWERS AND
THUNDERSTORMS LATER THIS AFTERNOON ALONG THE LEFT OVER OUTFLOW
BOUNDARIES DUE TO NOT ONLY DAY TIME HEATING BUT ALSO A WEAK
FRONTAL BOUNDARY. LEFT THE FLASH FLOOD WATCH AS IS FOR NOW.
CURRENT THINKING IS THAT MOST AREAS WILL SEE BETWEEN HALF AN INCH
TO AN INCH THROUGH TODAY AND THIS EVENING...WITH ISOLATED TOTALS
UP TO 2 AND 3 INCHES WITH THE SLOWER MOVING OR MORE INTENSE
THUNDERSTORMS.
&&
.PREV DISCUSSION... /ISSUED 642 AM CDT SAT MAY 30 2015/
AVIATION...
SHRA/ISOLD TSRA CURRENTLY ALONG A BOUNDARY FROM KDRT TO KERV TO
KBMQ TO KILE WILL SLOWLY WEAKEN AS IT MOVES TO THE SE ACROSS SOUTH
CENTRAL TEXAS THIS MORNING. BOUNDARIES AND A COLD FRONTAL PASSAGE
WILL LEAD TO SHRA/TSRA MIDDAY INTO TONIGHT. HAVE GONE WITH
SHRA/TSRA AT THE TAF SITES FOR 12Z TO 14Z AND TEMPOS FOR TSRA FOR
THIS AFTERNOON INTO EVENING WITH VCSH OTHERWISE. IFR/MVFR CIGS
BECOME VFR WITH THE PASSAGE OF THE BOUNDARY AND WILL GENERALLY
REMAIN VFR FOR THE REST OF TODAY THROUGH SUNDAY MORNING...EXCEPT
FOR MVFR CIGS IN SHRA/TSRA AND POSSIBLY A PERIOD TONIGHT. S TO SE
WINDS 5 TO 10 KTS WILL TURN TO N TO NE WITH THE SURFACE BOUNDARIES
AND FRONTAL PASSAGE. SOME GUSTS TO 50 KTS AND GR ARE POSSIBLE IN
AND NEAR TSRA.
PREV DISCUSSION... /ISSUED 253 AM CDT SAT MAY 30 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
THE MAIN HIGHLIGHT THIS PERIOD WILL FOCUS ON THE CURRENTLY
ONGOING THUNDERSTORM COMPLEX N/NW OF THE REGION AND ITS EVOLUTION
THROUGH THE DAY TODAY THAT COULD RESULT IN LOCALLY HEAVY RAINFALL
AND FLASH FLOODING. WILL BUMP UP THE TIMING OF THE FLASH FLOOD
WATCH TO START AT 4AM THIS MORNING GIVEN CURRENT TRENDS AND
CONTINUE IT THROUGH 7AM SUNDAY.
CURRENT RADAR IMAGERY ACROSS THE STATE OF TEXAS REVEALS A SOUTHWARD
TRAVELING THUNDERSTORM COMPLEX. RADAR TRENDS INDICATE A GUST
FRONT/OUTFLOW BOUNDARY HAD DEVELOPED OUT WELL AHEAD OF THE COMPLEX
AS IT PUSHES SOUTH AND THIS WILL LIKELY UNDERCUT THE UPDRAFTS AND
KEEP THEM IN A WEAKENED STATE. THE QUESTION BECOMES HOW WILL THIS
OUTFLOW BOUNDARY OR ANOTHER POSSIBLE BOUNDARY FROM THE STORMS
CURRENTLY IN NEW MEXICO AND HOW THEY MAY INTERACT WITH A SEA-BREEZE
WILL SHAPE TODAY`S RAIN AND THUNDERSTORM POTENTIAL. TODAY`S
RESULTANT STORM ACTIVITY WILL BE HIGHLY MESOSCALE DRIVEN WITH SOME
AID ON THE SYNOPTIC SCALE AS A WEAK SHORTWAVE TROUGH WILL BE OVER
THE REGION.
OVERALL, FEEL HRRR/RAP HAVE DECENT HANDLE ON CURRENT SITUATION AND
OVERALL SIGNALS FROM SPC SSEO SUGGEST THAT SOUTHWARD PROGRESSING
BOUNDARY AND WEAKENING STORMS WILL ENTER HILL COUNTRY AROUND 4-5AM.
GENERAL BAND OF LIGHT TO MODERATE RAIN MAY MAKE IT TO THE I-35
CORRIDOR NEAR 8-10AM WITH SOUTHERN AREAS REMAINING DRY THROUGH NOON.
THE QUESTION WILL BE HOW MUCH MOMENTUM WILL THIS BOUNDARY HAVE AND
HOW MUCH CLOUD COVER COULD RESULT. IF MOMENTUM SLOWS AND SETS UP A
CONVERGENCE BOUNDARY WITH THE SEA-BREEZE IN AN UNSTABLE ENVIRONMENT
THEN THE CONDITIONS WILL BE SET FOR LOCALIZED SHOWERS AND STORMS
WITH LOCALIZED HEAVY RAINFALL DURING THE AFTERNOON. A SECOND
SCENARIO IS THAT THE OUTFLOW CONTINUES THROUGH MUCH OF THE REGION
THROUGH LATE MORNING AND A SECOND BOUNDARY (FROM CURRENT NEW MEXICO
STORMS) IN COMBO WITH WEAK FRONT IN ASSOCIATION WITH THE SHORTWAVE
TROUGH AND ALSO ACTS TO HELP TRIGGER LOCALIZED HEAVY SHOWERS AND
STORMS. A THIRD SCENARIO WOULD BE THE FIRST BOUNDARY HANGS UP OVER
THE REGION BUT WITH SLIGHTLY STRONGER CONVECTION INITIALLY THIS
MORNING AND CREATES MORE CLOUD COVER/STRATIFORM RAIN. THIS WOULD
DEPLETE SOME OF THE AVAILABLE BUOYANT ENERGY LATER THIS AFTERNOON BY
KEEPING TEMPS DOWN AND KEEP THE ATMOSPHERE SLIGHTLY MORE STABLE. AT
THIS STAGE...FEEL THE FIRST TWO SCENARIOS ARE MORE LIKELY AND HAVE A
CONCERN FOR LOCALIZED HEAVY RAINFALL OF 1-2 INCHES WITH LOCALIZED 3
INCHES OVER ALREADY SATURATED GROUND. THESE CONDITIONS COULD LEAD TO
RAPID RUN-OFF AND LOCALIZED FLASH FLOODING. WILL MAINTAIN THE FLOOD
WATCH AS IS AREA WISE GIVEN PWATS 1.6" AND THE NUMEROUS TRIGGERS
POSSIBLE. OVERALL HEAVY RAIN THREAT WILL DIMINISH THROUGH SUNDAY
MORNING.
FOR SUNDAY...LINGERING SHOWERS AND SOME ISOLATED THUNDERSTORMS WILL
REMAIN POSSIBLE AS THE BASE OF THE TROUGH PIVOTS ACROSS THE REGION.
WHILE RAIN WILL BE POSSIBLE...HEAVY RAIN DOES NOT APPEAR LIKELY AT
THIS POINT.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
A MUCH NEEDED BREAK FROM THE ACTIVE WET PATTERN FINALLY LOOKS TO
DEVELOP IN THE LONG TERM PERIOD WITH NO MAJOR IMPACT WEATHER
HIGHLIGHTS.
BY MONDAY...GLOBAL MODELS ARE IN AGREEMENT THAT THE TROUGH FROM
SUNDAY WILL LINGER AND POSSIBLY CLOSE OFF IN THE NORTHERN GULF OR
LOWER MISSISSIPPI RIVER VALLEY. SHORTWAVE RIDGING AND DEEPER MID TO
UPPER LEVEL NORTHERLY FLOW MONDAY THROUGH WEDNESDAY SHOULD KEEP MOST
OF THE AREA DRY. THE ONLY SMALL CAVEAT WOULD BE LIMITED MOISTURE
RETURN IN THE LOW-LVLS FROM SE SURFACE WINDS. THERE MAY BE SOME SEA-
BREEZE ACTIVITY THAT COULD MAKE INTO FAR SE COASTAL PRAIRIE ZONES BUT
COVERAGE IS NOT EXPECTED TO BE HIGH. GLOBAL MODELS DIVERGE MID-WEEK
ON STRENGTH OF THE RIDGE OVER TEXAS WITH GFS BEING WEAKER WITH
IMPULSES RIDING THE NORTH EDGE ACROSS THE PANHANDLE WHILE ECMWF IS
MUCH STRONGER WITH LITTLE EVIDENCE OF DISTURBANCES. WILL HAVE TO
MONITOR HOW THIS EVOLVES AND WATCH FOR ANY NW FLOW TSTORM COMPLEX
DEVELOPING ON THE DRYLINE IN FAR W/NW TEXAS AND POSSIBLY SHIFTING
THIS DIRECTION. CONFIDENCE IN THIS POSSIBILITY IS NOT HIGH AT THIS
POINT HOWEVER. GFS ENSEMBLES SUPPORT THE ECMWF AND IT APPEARS A WEAK
TO MODERATE OMEGA BLOCK COULD TAKE FORM MID TO LATE WEEK WITH TEXAS
UNDER THE DRIER RIDGE. THIS WILL ALLOW FOR SWOLLEN AND ELEVATED
RIVER LEVELS TO RECEDE. TEMPERATURES SHOULD BE NEAR NORMAL WITH
READINGS IN THE UPPER 80S/LOW 90S AND LOWS IN THE UPPER 60S/NEAR 70.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 83 67 81 65 85 / 70 50 30 10 10
AUSTIN BERGSTROM INTL AIRPORT 82 66 81 62 85 / 70 60 30 10 10
NEW BRAUNFELS MUNI AIRPORT 84 67 82 65 86 / 70 60 30 10 10
BURNET MUNI AIRPORT 80 65 79 63 84 / 70 50 20 10 10
DEL RIO INTL AIRPORT 86 67 85 68 89 / 70 40 30 10 10
GEORGETOWN MUNI AIRPORT 81 65 80 62 84 / 70 50 20 10 10
HONDO MUNI AIRPORT 86 67 83 66 86 / 70 50 30 10 10
SAN MARCOS MUNI AIRPORT 83 66 81 64 84 / 70 60 30 10 10
LA GRANGE - FAYETTE REGIONAL 83 68 81 65 85 / 70 60 30 10 20
SAN ANTONIO INTL AIRPORT 85 68 83 67 86 / 70 50 30 10 10
STINSON MUNI AIRPORT 86 69 83 67 86 / 70 50 30 10 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...
KINNEY...LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...
UVALDE...VAL VERDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
655 AM EDT SAT MAY 30 2015
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL MAINTAIN A VERY WARM AND HUMID AIR
MASS ACROSS THE REGION TODAY INTO SUNDAY. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST LATE IN THE WEEKEND...BEFORE PUSHING
SOUTH OF THE AREA BY MONDAY...RESULTING IN MORE WIDESPREAD SHOWERS
AND THUNDERSTORMS LATER SUNDAY INTO MONDAY AFTERNOON. COOLER
WEATHER UNDER HIGH PRESSURE WILL BUILD IN BY THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 222 AM EDT SATURDAY...
ISOLATED SHOWERS HAVE FINALLY ALL BUT FADED ACROSS THE REGION EARLY
THIS MORNING LEAVING MORE PATCHY FOG AND LOW/MID CLOUDS TO INIT.
HOWEVER AGAIN EXPECTING THIS MOISTURE TO QUICKLY BURN OFF THIS MORNING
LEADING TO ANOTHER RATHER HOT AND HUMID AFTERNOON AS UPPER HEIGHTS
ACTUALLY RISE JUST A BIT FROM THE EAST DURING THE DAY. THIS SHOULD
ALLOW AN AREA OF WEAK SUBSIDENCE THAT WAS TO THE SE ON FRIDAY TO PUSH
NORTH/NW AND PUT MORE OF A LID ON CONVECTION GIVEN FORECAST DRYING
ALOFT OFF SOUNDINGS. LATEST GUIDANCE ALSO SHOWING A DROP IN PWATS THIS
AFTERNOON WITH MORE OF A SOUTHERLY TRAJECTORY DEVELOPING AHEAD OF THE
NEXT 5H TROUGH TO THE WEST. APPEARS BEST WEAK CONVERGENCE TO TAKE PLACE
OVER THE NW WHERE SLIGHTLY BETTER RESIDUAL MOISTURE UNDER A LEFTOVER
WEAKNESS ALOFT MAY ACT TO ENHANCE LIFT A BIT MORE TO PRODUCE A
SCATTERING OF CONVECTION. THIS IN LINE WITH MOST SOLUTIONS AND ESPCLY
THE LATEST NCAR ENSEMBLE AND HRRR BUT STILL NO MORE THAN CHANCE POPS AT
BEST. ELSEWHERE CANT TOTALLY RULE OUT AT LEAST ISOLATED SHRA/TSRA PER
HEATING...DECENT INSTABILITY...AND HIGH 85H THETA-E WITH BEST CHANCES
MOUNTAINS WHERE AIDED BY OROGRAPHICS ESPCLY BLUE RIDGE.
SHOULD BE ONE OF THE WARMEST DAYS SO FAR THIS SEASON GIVEN A WARM START
AND LESS EXPECTED CLOUDS/TSRA THIS AFTERNOON. AGAIN APPEARS MOS A BIT
COOL AS SEEN OVER THE PAST COUPLE OF DAYS AS THICKNESS SUGGESTS HIGHS
CLOSE TO 90 SE...WITH LOW/MID 80S ELSEWHERE OUTSIDE OF THE HIGHEST
ELEVATIONS.
ANY EVENING CONVECTION MAY LINGER ESPCLY MOUNTAINS AN HOUR OR TWO AFTER
SUNSET BEFORE LOSS OF HEATING AND LACK OF FORCING CAUSE SHOWERS TO FADE
SO WILL KEEP SOME LOW POPS GOING THIS EVENING MAINLY FAR WEST. UPSTREAM
PRE-FRONTAL SHRA/TSRA WILL THEN BE THE MAIN CONCERN OVERNIGHT BUT
APPEARS MUCH OF THIS TOO FAR WEST TO REACH THE REGION BY DAYBREAK
SUNDAY. HOWEVER RETURN OF DEEPER MOISTURE AHEAD OF THE TROUGH/FRONT AS
SEEN IN MODEL PWATS LATE SUPPORTS INCLUDING SOME ISOLATED TO LOW CHANCE
POPS MAINLY WESTERN THIRD LATE. OTHERWISE MAINLY PC WITH ADDED PATCHY
FOG BY MORNING. TEMPS TO REMAIN ON THE WARM/MUGGY SIDE WITH MOST SPOTS
ONLY FALLING INTO THE 60-66 RANGE.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 245 AM EDT SATURDAY
THE MEDIUM RANGE MODELS ARE ALL IN CONSENSUS THAT A SFC COLD FRONT..
ASSOCIATED WITH AN UPPER TROUGH MOVING THROUGH THE EASTERN GREAT
LAKES INTO NEW ENGLAND...MOVES THROUGH OUR FORECAST AREA MONDAY.
HOWEVER...THE MORE NOTICEABLE DRIER AIR AND COOLER TEMPS ARRIVE
MONDAY NIGHT/EARLY TUESDAY ONCE SOUTHERN STREAM ENERGY AND
ASSOCIATED SFC WAVE LIFT EAST.
THE FORECAST AREA WILL REMAIN FIRMLY ENTRENCHED IN THE WARM SECTOR
SUNDAY. WHILE INSTABILITY WILL INCREASE AS HIGHER PWAT AIR
RETURNS...BEST SHEAR AND UPPER LEVEL DYNAMICS REMAIN NORTH AND WEST
OF THE FORECAST AREA THROUGH SUNDAY. WHILE AN ISOLATED SEVERE STORM
IS POSSIBLE...GREATER CONCERN MAY BE WITH LOCALLY HEAVY DOWNPOURS.
WITH THE SLOWER ARRIVAL OF THE FRONT...PUSHED UP TEMPS A COUPLE OF
DEGREES FOR HIGHS...ESPECIALLY IN THE EAST.
KEPT POPS GOING AFTER SUNDOWN SUNDAY WITH FORCING FROM SFC BOUNDARY
MOVING INTO THE AREA. WENT ABOVE GUIDANCE FOR LOWS SUNDAY NIGHT DUE
TO CLOUDS AND SOME MIXING.
PRECIPITATION MAY BE MORE WIDESPREAD MONDAY...ESPECIALLY IN THE
SOUTHERN HALF OF THE FORECAST AREA...AS SFC BOUNDARY SLOWS SOMEWHERE
IN THE EASTERN PORTION OF THE FORECAST AREA DUE TO A SFC WAVE FROM
SOUTHERN STREAM ENERGY DEVELOPING IN NC. EXPECT MORE CLOUD COVER AND
SLIGHTLY COOLER TEMPS ON MONDAY...AS A RESULT...LOWER INSTABILITY.
THE EXCEPTION WOULD BE IN ADVANCE OF THE FRONT...IN THE FAR EASTERN
PORTION OF THE FORECAST AREA WHERE AN ISOLATED SEVERE STORM CANNOT
BE RULED OUT.
DRIER/COOLER AIR FINALLY SURGES INTO THE FORECAST AREA MONDAY NIGHT
AND TUESDAY. LEANED TOWARD THE COOLER GUIDANCE VALUES DURING THIS
PERIOD. WHILE THE SFC BOUNDARY PUSHES SOUTH OF THE FORECAST AREA BY
TUESDAY...850MB THETA-E AXIS LINGERS IN NC AND SOUTHERN VA AND WEAK
OVERRUNNING WILL KEEP THE THREAT FOR SHOWERS FOR THIS AREA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 245 PM EDT FRIDAY...
THE COLD FRONT WILL WASH OUT OVER OR JUST SOUTH OF THE AREA BY
TUESDAY AFTERNOON. AFTER THIS POINT...THE REGION WILL START TO
TRANSITION BACK A SOUTHERLY FLOW PATTERN AS A LOW/TROUGH DEVELOPS
ACROSS THE LOWER MISSISSIPPI RIVER VALLEY...AND HIGH PRESSURE
BECOMES CENTERED AGAIN OFF THE COAST OF THE CAROLINAS. DAYTIME
HEATING ALONG WITH PIECES OF ENERGY EJECTING OFF THE LOWER
MISSISSIPPI VALLEY LOW WILL HELP YIELD INCREASING CHANCE OF SHOWERS
AND STORMS AGAIN BY THURSDAY INTO FRIDAY. TEMPERATURES WILL ALSO
START TO TREND MILDER THURSDAY INTO FRIDAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 640 AM EDT SATURDAY...
FOG REMAINS PATCHY ACROSS THE REGION EARLY THIS MORNING BUT DENSE
IN SPOTS WITH IFR/LIFR AT KBCB/KLWB AND AREAS OF MVFR AROUND KROA.
THIS ALSO RESULTING IN SOME LOWER STRATUS AS WELL WITH MOSTLY MID
DECK ELSEWHERE OVER THE MOUNTAINS WHERE STILL SEEING ISOLATED
SHOWERS NW OF KLWB. EXPECT FOG/LOW CLOUDS TO QUICKLY ERODE WITH
HEATING AROUND 13Z/9AM...FOLLOWED BY DEVELOPMENT OF VFR 4-6K FT
CU FIELDS BY MIDDAY INTO THIS AFTERNOON. HOWEVER...UNLIKE
FRIDAY...EXPECT SOME SUBSIDENCE NUDGING IN FROM THE SOUTHEAST SUCH
THAT ANY DIURNAL REDEVELOPMENT OF SHOWERS/STORMS BY LATE
MORNING/EARLY AFTERNOON EXPECTED TO BE LESS IN OVERALL COVERAGE
AND MAINLY CONFINED TO SOUTHEAST WEST VIRGINIA. THEREFORE...VCTS
KEPT AT KBLF AND KLWB AROUND 17Z/1PM...BUT NOT AT THE REMAINING
AVIATION FORECAST POINTS FOR NOW GIVEN MORE EXPECTED ISOLATED
NATURE TO ANY CONVECTION.
ANY SHOWERS/STORMS SHOULD AGAIN FADE WITH LOSS OF HEATING THIS
EVENING BUT WITH DEEPER MOISTURE RETURNING OVERNIGHT AHEAD OF THE
FRONT TO THE WEST COULD SEE A BIT MORE ISOLATED COVERAGE LATER
TONIGHT. HOWEVER NOT ENOUGH TO INCLUDE MENTION IN THE TAFS WITH
MORE IFR/LIFR FOG POSSIBLE AT KLWB/KBCB BY DAYBREAK SUNDAY WITH
PATCHY BUT BRIEF MVFR ELSEWHERE ACROSS THE VALLEYS.
EXTENDED DISCUSSION...
ON SUNDAY...A MOIST UNSTABLE AIR MASS WILL REMAIN IN PLACE ACROSS
THE REGION WITH BETTER SW FLOW AHEAD OF A COLD FRONT NEARING THE
MOUNTAINS BY SUNDAY EVENING. THIS WILL RESULT IN DEVELOPMENT OF
MORE WIDESPREAD CONVECTION INITIALLY ALONG THE BLUE RIDGE SUNDAY
AFTERNOON AND ACROSS MUCH OF THE WEST LATE IN THE DAY AS THE FRONT
APPROACHES. SOME OF THE CONVECTION MAY SPREAD EAST OF THE BLUE
RIDGE LATER IN THE AFTERNOON SO POTENTIAL FOR A LITTLE MORE IN THE
WAY OF PERIODIC SUB-VFR SUNDAY AFTERNOON/EVENING ESPCLY OVER THE
MOUNTAIN LOCATIONS.
A FRONTAL SYSTEM WILL CONTINUE TO SLOWLY APPROACH THE AREA FROM
THE NORTHWEST SUNDAY NIGHT. THIS BOUNDARY SHOULD FINALLY SINK
SOUTH INTO THE REGION BY MONDAY RESULTING IN WIDESPREAD
CONVECTION ESPCLY BLUE RIDGE EAST...WITH ADDITIONAL ROUNDS OF
SHRA/TSRA INTO AT LEAST MONDAY NIGHT BEFORE THE BOUNDARY SINKS TO
THE SOUTH. THIS SHOULD MAKE FOR MORE FREQUENT PERIODS OF SUB- VFR
FROM SUNDAY NIGHT INTO TUESDAY WITH LOWER CIGS/VSBY REDUCTIONS
DUE TO SHOWERS/STORMS DURING THE DAY...AND IN FOG OVERNIGHT INTO
THE EARLY MORNING HOURS EACH DAY. LOWER MVFR/IFR CIGS ARE LIKELY
BEHIND THE FRONT INTO WEDNESDAY WITH EASTERLY FLOW AND WEDGING IN
PLACE RESULTING IN MVFR CEILINGS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...JH
SHORT TERM...PH
LONG TERM...DS
AVIATION...AMS/JH/WERT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
204 PM EDT SAT MAY 30 2015
.SYNOPSIS...
DRY WEATHER WILL CONTINUE FOR TODAY THANKS TO AN AREA OF HIGH
PRESSURE. A COLD FRONT WILL SLOWLY MOVE ACROSS THE REGION
SUNDAY...THEN STALL SOUTH OF NEW ENGLAND EARLY NEXT WEEK. THIS
WILL BRING A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS
SUNDAY...AND A PERIOD OF RAIN EARLY NEXT WEEK. HIGH PRESSURE
BRINGS DRY WEATHER FOR THE LATTER PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
2 PM UPDATE...
CONVECTION FIRING ACROSS E NY EARLY THIS AFTERNOON IN AXIS OF
GREATEST INSTABILITY AND MOISTURE. FURTHER E ACROSS W NEW
ENG...MLCAPES OF 500-1000 J/KG HAVE DEVELOPED BUT KI VALUES ARE
LESS THAN WHAT IS OBSERVED OVER E NY...MOSTLY LESS THAN 30
INDICATING LESS MOISTURE. KI VALUES ARE FORECAST TO INCREASE A
BIT SO CANT RULE OUT AN ISOLD SHOWER/TSTM IN W MA AND HRRR
CONTINUES TO SUGGEST ISOLD CONVECTION.
STRATUS AND FOG CONFINED TO S COASTAL WATERS AND ISLANDS AND
LIFTING N SO AREAS OF LOW CLOUDS/FOG POSSIBLE ALONG THE IMMEDIATE
S COAST AND CAPE COD.
PREVIOUS DISCUSSION...
THE MAIN FORECAST QUESTION IS EXTENT OF ANY CONVECTION THIS
AFTERNOON. MID LEVEL RIDGE REMAINS JUST OFF THE COAST WHICH WILL
SLOW COLD FRONT AS IT MOVES THROUGH THE GT LAKES AND STABILIZE E
HALF NEW ENG. MAIN FOCUS FOR CONVECTION WILL BE ACROSS UPSTATE NY
AND VT IN HIGHER THETA-E AXIS AND BETTER INSTABILITY. MODELS DO
GENERATE MARGINAL INSTABILITY IN W NEW ENG WITH CAPES 500-1000
J/KG BUT 0-6KM SHEAR IS QUITE WEAK. HRRR SHOWS A FEW ISOLD SHOWERS
DEVELOPING IN THE WEST THIS AFTERNOON AND WILL KEEP SLIGHT CHC
POPS W MA FOR A BRIEF SHOWER/TSTM THIS AFTERNOON...BUT MOST OF THE
AREA WILL REMAIN DRY.
HIGH TEMPS WILL REACH THE LOW TO MID 80S ACROSS MUCH OF THE
REGION AWAY FROM THE S COAST WITH WARMEST TEMPS IN THE UPPER 80S
LIKELY ACROSS INTERIOR NE MA. OTHERWISE 70S NEAR THE S COAST DUE
TO GUSTY SW FLOW. IN FACT...SOUNDINGS SUPPORT WIND GUSTS TO 25-30
MPH TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
NOTICED GUIDANCE CONTINUES TO SLOW DOWN THE FRONTAL PASSAGE...SO
HAVE ADJUSTED THE FORECAST TO ACCOUNT FOR THIS TREND.
THE COLD FRONT WILL BEGIN TO APPROACH THE REGION
TONIGHT...BRINGING SOME MUCH NEED RAINFALL TO THE REGION. AS THE
FRONT APPROACHES GUIDANCE INDICATES THAT SHOWALTERS WILL BE BELOW
0 WITH K VALUES ABOVE 30C. THEREFORE CANNOT RULE OUT SOME
EMBEDDED THUNDER OVERNIGHT. AREA THAT WILL SEE THE HIGHER RAINFALL
AMOUNTS WILL BE NORTH OF THE PIKE...ESP NORTH OF ROUTE 2.
SINCE THE FRONT WILL STILL BE NORTHWEST OF THE REGION...ANTICIPATE
ANOTHER ROUND OF FOG TO DEVELOP ALONG THE SOUTH COAST/CAPE AND
ISLANDS AS MOISTURE POOLS ALONG THE FRONT. LOW CONFIDENCE IF IT WILL
BE DENSE OR NOT.
TOMORROW...
TIMING OF THE COLD FRONT IS STILL IN QUESTION AS LATEST GUIDANCE
TREND IS TO SLOW DOWN THE FRONT. REGARDLESS BELIEVE THAT THE FRONT
WILL CROSS SOUTHERN NEW ENGLAND ON SUNDAY BRINGING SOME MUCH NEEDED
RAIN. GUIDANCE STILL SHOWS ELEVATED THUNDER PARAMETERS...SO WILL
CONTINUE TO MENTION THUNDER IN THE FORECAST...BUT STRONG TO SEVERE
STORMS ARE NOT EXPECTED.
BOTH THE NAM AND GFS INDICATE GOOD BOUNDARY LAYER MOISTURE ALONG THE
FRONT AS IS BEGINS TO STALL OVER THE REGION. WITH PWAT VALUES AROUND
1.6 INCHES AND THE FRONT BECOMING ALIGNED WITH THE UPPER FLOW
ALOFT...COULD SEE THE POTENTIAL FOR HEAVY RAIN AND FLOODING DUE TO A
SLOW STORM MOTION. BECAUSE OF THE UNCERTAINTY ON WHERE THE FRONT
WILL STALL...HELD OFF ON ISSUING ANY SORT OF FLOOD WATCH AT THIS
TIME. RIGHT NOW BELIEVE THAT LOCATIONS ALONG AND NORTH OF THE MASS
PIKE WILL SEE THE HIGHER PRECIP AMOUNTS ON SUNDAY. PERHAPS IT WILL
PUSH WORCESTER OUT OF THE TOP 5 DRIEST MAYS ON RECORD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
OVERVIEW AND MODEL PREFERENCES...
QUITE A CHANGE IN THE SOLUTIONS OF THE 30/00Z GUIDANCE FROM THOSE
JUST 24 HOURS AGO. THE TREND HAS BEEN FOR A SIGNIFICANT SLOW-DOWN
OF A COLD FRONTAL PASSAGE SUNDAY NIGHT INTO MONDAY. SOME MINOR
DIFFERENCES REMAIN...BUT IT WAS NOTEWORTHY THAT JUST ABOUT ALL OF
THE GUIDANCE LATCHED ON TO THIS SLOWER TIMING. MODELS HAVE ALSO
COME INTO BETTER AGREEMENT WITH THEIR HANDLING OF A MID LEVEL
TROUGH EARLY NEXT WEEK. MORE RIDGING RETURNS FOR LATE NEXT WEEK.
FAVORED A MODEL CONSENSUS SOLUTION FOR THIS FORECAST UPDATE TO
SMOOTH OVER THE MINOR DIFFERENCES...WHERE POSSIBLE.
THE DAILIES...
SUNDAY NIGHT THROUGH TUESDAY...DIFFERENCES AMONG THE MODELS ON
TIMING A FRONTAL PASSAGE...BUT ALL MOVE IT TO THE SOUTH COAST OF
NEW ENGLAND BY SUNDAY EVENING. THIS FRONT THEN SHOULD ALIGN WITH
THE UPPER FLOW AND STALL. A SHORTWAVE MOVING THROUGH THE GREAT
LAKES IS FORECAST TO GENERATE A WAVE ALONG THIS FRONT...WHICH
CROSSES THE APPALACHIANS MONDAY AND PASSES SOUTH OF NEW ENGLAND
TUESDAY. THIS LOW PRESSURE...ALONG WITH HIGH PRESSURE OVER EASTERN
CANADA...SHOULD BRING A COOL NORTHEAST FLOW TO THE REGION MONDAY
AND TUESDAY. MEANWHILE A SOUTHWEST FLOW CONTINUES ALOFT...
PROVIDING BOTH LIFT AND MOISTURE. WE WILL MAINTAIN LIKELY POPS
MONDAY...DIMINISHING TO CHANCE POPS BY LATE TUESDAY AS THIS LOW
MOVES EAST.
WEDNESDAY THROUGH FRIDAY...HIGH PRESSURE BUILDS AT THE SURFACE
AND ALOFT...BRINGING DRY WEATHER TO SOUTHERN NEW ENGLAND. LIGHT
WINDS WILL FAVOR LOCAL SEABREEZES DURING THE DAYLIGHT HOURS.
HOWEVER...THE INCREASED SUNSHINE WILL FAVOR A GRADUAL WARM-UP
ACROSS THE INTERIOR EACH DAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH 00Z...MOSTLY VFR...BUT AREAS OF IFR STRATUS/FOG POSSIBLE
ALONG IMMEDIATE S COAST AND ISLANDS. LOW RISK OF A SPOT SHOWER/
THUNDERSTORM ACROSS WESTERN MA.
TONIGHT...MODERATE CONFIDENCE. EXPECT IFR/LIFR STRATUS AND FOG TO
DEVELOP ALONG THE S COAST THIS EVENING THEN SLOWLY SPREAD NWD
ACROSS SNE. FOG WILL BE MAINLY CONFINED TO THE SE COASTAL NEW ENG
WITH AREAS OF MVFR/IFR CIGS WILL EXPAND N ACROSS MUCH OF THE
REGION OVERNIGHT. A FEW SHOWERS AND POSSIBLE A TSTM DEVELOPING
OVERNIGHT IN THE INTERIOR.
SUNDAY...MODERATE CONFIDENCE. WIDESPREAD MVFR/IFR CONDITIONS.
NUMEROUS SHOWERS AND TSTMS DEVELOPING AS COLD FRONT DROPS S ACROSS
SNE. MAIN FOCUS WILL BE NEAR THE MASS PIKE. WINDS SHIFTING FROM SW
TO NE BEHIND THE FRONT WITH G25 KT POSSIBLE NE MA IN THE
AFTERNOON. TIMING OF FRONT...15-18Z ALONG AND N OF MASS PIKE
REACHING S COAST 21-00Z.
SUNDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD MVFR/IFR
CONDITIONS. SHOWERS LIKELY...ESPECIALLY INTERIOR.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. IFR CONDITIONS LIKELY
DEVELOP SUN AFTERNOON AS WINDS SHIFT TO NE BEHIND THE FRONT.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK...MONDAY THROUGH WEDNESDAY...MODERATE CONFIDENCE.
MONDAY THROUGH TUESDAY...MVFR/IFR CIGS AND VSBYS...MOST LIKELY
OVER THE COASTAL PLAIN AND ALONG THE EASTERN SLOPES OF THE
WORCESTER HILLS. SHOWERS POSSIBLE THROUGH BOTH DAYS.
WEDNESDAY...VFR WITH A LIGHT NORTH-NORTHWEST WIND. LOCAL
SEABREEZES POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH SUNDAY/...
TODAY...MODERATE TO HIGH CONFIDENCE. EXCELLENT MIXING OVER THE
LAND WILL GENERATE NEAR SHORE SMALL CRAFT WIND GUSTS OF 25 TO 30
KNOTS THIS AFTERNOON. IN ADDITION...SOUTHEAST SWELL WILL GENERATE
5 FOOT SEAS ACROSS THE OUTER-WATERS. THEREFORE...SMALL CRAFT
HEADLINES POSTED FOR ALL WATERS. AREAS OF FOG SHOULD IMPROVE
SOMEWHAT BY AFTERNOON.
TONIGHT...MODERATE TO HIGH CONFIDENCE. NEAR SHORE SMALL CRAFT
WIND GUSTS SHOULD DIMINISH BY THE EVENING. HOWEVER...5 FOOT SWELL
WILL CONTINUE ACROSS THE OUTER-WATERS. AREAS OF DENSE FOG
POSSIBLE TONIGHT.
SUNDAY...MODERATE CONFIDENCE. MAY NEED TO EXTEND SCA FOR CAA
BEHIND A PASSING COLD FRONT FROM THE NORTH. OTHERWISE EXPECT
SHOWERS WITH EMBEDDED THUNDER COULD OCCUR AHEAD OF THE FRONT DURING
THE AFTERNOON HOURS.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...MODERATE CONFIDENCE.
MONDAY-TUESDAY...SMALL CRAFT ADVISORY MAY BE NEEDED...ESPECIALLY
ON THE EASTERN COASTAL WATERS. NORTHEAST WINDS GUSTING UP TO 20
KT...AND PERHAPS A FEW GUSTS TO 25 KNOTS...EACH DAY. SEAS 5 TO 8
FEET ON THE EASTERN MA WATERS...AND 3 TO 5 FEET ON THE SOUTHERN
WATERS.
WEDNESDAY...A SMALL CRAFT ADVISORY MAY BE NEEDED...MAINLY ON THE
EASTERN WATERS. DIMINISHING NORTHEAST TO NORTH WINDS. SEAS OF 5 FEET
MAY LINGER ON THE EASTERN WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
ANZ230>237-251.
SMALL CRAFT ADVISORY UNTIL 3 PM EDT SUNDAY FOR ANZ250-254>256.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...KJC
SHORT TERM...DUNTEN
LONG TERM...BELK
AVIATION...BELK/KJC
MARINE...BELK/DUNTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
103 PM CDT SAT MAY 30 2015
.UPDATE...
ISSUED AT 1112 AM CDT SAT MAY 30 2015
WIDESPREAD CLOUDS/SHOWERS BLANKET THE WESTERN HALF OF THE KILX CWA
THIS MORNING...WHILE SOME PEEKS OF SUNSHINE ARE OCCURRING FURTHER
EAST ACROSS EAST-CENTRAL AND SOUTHEAST ILLINOIS. DUE TO THE
PARTIAL SUNSHINE AND A CONTINUED SOUTHERLY FLOW...TEMPERATURES
HAVE RISEN WELL INTO THE 70S AND EVEN THE LOWER 80S IN SOME
LOCATIONS ALONG/EAST OF THE I-57 CORRIDOR. THIS IS THE AREA WE
WILL BE WATCHING FOR POTENTIAL STRONG TO SEVERE THUNDERSTORM
DEVELOPMENT LATER TODAY AS LOW PRESSURE CURRENTLY OVER SOUTHEAST
MISSOURI TRACKS ACROSS SOUTHERN ILLINOIS. ENHANCED LOW-LEVEL WIND
SHEAR NEAR THE LOW WILL INTERACT WITH A MODERATELY UNSTABLE
ENVIRONMENT TO TRIGGER WIDESPREAD THUNDERSTORMS. LATEST DAY 1
OUTLOOK FROM SPC HIGHLIGHTS LOCATIONS ALONG/SOUTHEAST OF A
CHAMPAIGN TO SHELBYVILLE LINE WITH A SLIGHT RISK FOR SEVERE LATER
TODAY. BASED ON HRRR FORECASTS...IT APPEARS THE PRIMARY TIME FRAME
WILL BE BETWEEN 2 PM AND 8 PM. MADE A FEW MINOR ADJUSTMENTS TO THE
GOING FORECAST...BUT OVERALL TREND IS RIGHT ON TRACK.
&&
.SHORT TERM...(TODAY)
ISSUED AT 328 AM CDT SAT MAY 30 2015
LOW PRESSURE IS PROJECTED TO TRACK IN A NORTHEAST DIRECTION ACROSS
SOUTHEAST ILLINOIS TODAY, WITH A COLD FRONT PUSHING ACROSS ILLINOIS
FROM NW TO SE DURING THE DAY. BOTH FEATURES WILL PROVIDE A FOCUS FOR
AN EXTENDED PERIOD OF RAIN SHOWERS AND SCATTERED THUNDERSTORMS IN
CENTRAL AND SOUTHEAST ILLINOIS. AN INTENSIFYING SOUTHERLY LOW LEVEL
JET WILL PROGRESS ACROSS SOUTHERN IL AHEAD OF THE LOW...WITH SPEED
CONVERGENCE MAXIMIZED ON AN AXIS FROM SW TO NE ACROSS OUR FORECAST
AREA. THAT LLJ WILL AID IN MOISTURE TRANSPORT PUSHING PRECIP WATER
VALUES INTO THE 1.5 TO 2 INCH RANGE. FLASH FLOOD GUIDANCE FOR ONE
HOUR IS GENERALLY 2 TO 2.5 INCHES IN AREAS THAT ARE EXPECTED TO SEE
THE HIGHER PRECIP TOTALS. SOME CONCERN FOR A FLASH FLOOD WATCH
SOUTHEAST OF THE ILLINOIS RIVER, BUT MOST OF THAT AREA SHOULD BE
ABLE TO HANDLE THE RAINFALL THAT OCCURS WITH THIS SYSTEM. PEAK
INSTABILITY THIS AFTERNOON IS FORECAST TO REACH TO AROUND 1500 J/KG
MUCAPE SE OF I-55, WHICH WILL INCREASE RAINFALL RATES WITH STRONGER
UPDRAFT DEVELOPMENT. SEVERE STORMS ARE NOT EXPECTED, BUT A FEW
STORMS CLOSER TO THE TRACK OF THE LOW SE OF I-55 COULD SEE SOME
SMALL HAIL AND GUSTY WINDS.
HIGH TEMPS WILL BE HELD IN CHECK BY THE WIDESPREAD CLOUD COVER AND
PERIODIC RAIN. HIGHS WILL STRUGGLE TO REACH 70 AROUND GALESBURG,
WITH LOW 80S FOR 80S SE OF I-70 WHERE SOME PEEKS OF SUN MAY OCCUR
THIS MORNING TO HELP BOOST TEMPS.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 328 AM CDT SAT MAY 30 2015
SURFACE LOW PROJECTED TO RIDE JUST NORTH OF THE OHIO RIVER AND THEN
INTO CENTRAL INDIANA TONIGHT...WITH MOST OF THE MODELS FAVORING A
POSITION IN EAST CENTRAL INDIANA BY SUNDAY MORNING. SOME HEAVIER
RAINS SHOULD CONTINUE TO AFFECT EASTERN ILLINOIS INTO THE FIRST PART
OF THE EVENING WITH THIS TRACK...WHERE CATEGORICAL POP`S WILL BE IN
PLACE FOR THE FIRST FEW HOURS. WITH THE CHANGES TO THE TRACK...HAVE
HAD TO RE-ORIENT THE ORIGINAL POP GRIDS TO FAVOR A MORE WEST-EAST
TAPERING OF THE RAIN VS A CLEARING FROM THE NORTHWEST. THUS...POP`S
WILL LINGER EAST OF I-57 PAST MIDNIGHT. TOTAL QPF FOR TODAY AND
TONIGHT EXPECTED TO BE IN THE 1.5 INCH RANGE IN AREAS FROM EFFINGHAM
NORTHEAST TO DANVILLE. STIFF NORTH/NORTHEAST WIND WILL DRIVE IN MUCH
COOLER AIR INTO THE AREA...ALTHOUGH THERE WILL BE A TIGHT
TEMPERATURE GRADIENT ACROSS THE FAR EAST DEPENDING ON THE SPEED OF
THE DEPARTING LOW.
MUCH QUIETER WEATHER EXPECTED SUNDAY AND MONDAY IN THE WAKE OF THE
DEPARTING SYSTEM. SURFACE HIGH TO BUILD SOUTHWARD THROUGH THE GREAT
LAKES...AND WILL NOT BE IN ANY PARTICULAR HURRY TO LEAVE. GFS AND
ECMWF TAKE UNTIL LATE WEDNESDAY/EARLY THURSDAY TO PUSH THIS SYSTEM
INTO THE EASTERN GREAT LAKES REGION...RESULTING IN DRY CONDITIONS
FOR OUR AREA. IN FACT...THEY BASICALLY KEEP THINGS DRY UNTIL LATE
THURSDAY OR FRIDAY AS UPPER LEVEL HEIGHTS BUILD DUE TO HIGH PRESSURE
IN THE PLAINS. TEMPERATURES WILL START OFF RATHER COOL WITH HIGHS IN
THE 60S TO AROUND 70 SUNDAY AND MONDAY...BUT 80S SHOULD RETURN BY
MID WEEK AS THE HIGH PUSHES FARTHER EAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 103 PM CDT SAT MAY 30 2015
OCCASIONAL SHOWERS WILL PERSIST AT THE KILX TERMINALS THROUGH THE
AFTERNOON AS LOW PRESSURE TRACKS ACROSS SOUTHERN ILLINOIS. MODEL
CONSENSUS BRINGS THE RAIN TO AN END AT KPIA BY AROUND 23Z...THEN
FURTHER EAST TO KCMI BY 05Z. CEILINGS WILL GENERALLY BE IN THE
MVFR CATEGORY THROUGH THE AFTERNOON...HOWEVER AS WINDS SWING
AROUND TO THE N/NE ON THE BACK SIDE OF THE DEPARTING LOW...A
PERIOD OF VFR CEILINGS IS LIKELY FROM LATE AFTERNOON THROUGH THE
EVENING. STRONG/GUSTY WINDS WILL DEVELOP AS WELL...WITH FORECAST
SOUNDINGS SUGGESTING GUSTS OF 20 TO 25KT. PRESSURE GRADIENT WILL
REMAIN TIGHT THROUGH THE NIGHT...SO STRONG N/NE WINDS WILL
CONTINUE THROUGH 18Z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...SHIMON
LONG TERM...GEELHART
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1112 AM CDT SAT MAY 30 2015
.UPDATE...
ISSUED AT 1112 AM CDT SAT MAY 30 2015
WIDESPREAD CLOUDS/SHOWERS BLANKET THE WESTERN HALF OF THE KILX CWA
THIS MORNING...WHILE SOME PEEKS OF SUNSHINE ARE OCCURRING FURTHER
EAST ACROSS EAST-CENTRAL AND SOUTHEAST ILLINOIS. DUE TO THE
PARTIAL SUNSHINE AND A CONTINUED SOUTHERLY FLOW...TEMPERATURES
HAVE RISEN WELL INTO THE 70S AND EVEN THE LOWER 80S IN SOME
LOCATIONS ALONG/EAST OF THE I-57 CORRIDOR. THIS IS THE AREA WE
WILL BE WATCHING FOR POTENTIAL STRONG TO SEVERE THUNDERSTORM
DEVELOPMENT LATER TODAY AS LOW PRESSURE CURRENTLY OVER SOUTHEAST
MISSOURI TRACKS ACROSS SOUTHERN ILLINOIS. ENHANCED LOW-LEVEL WIND
SHEAR NEAR THE LOW WILL INTERACT WITH A MODERATELY UNSTABLE
ENVIRONMENT TO TRIGGER WIDESPREAD THUNDERSTORMS. LATEST DAY 1
OUTLOOK FROM SPC HIGHLIGHTS LOCATIONS ALONG/SOUTHEAST OF A
CHAMPAIGN TO SHELBYVILLE LINE WITH A SLIGHT RISK FOR SEVERE LATER
TODAY. BASED ON HRRR FORECASTS...IT APPEARS THE PRIMARY TIME FRAME
WILL BE BETWEEN 2 PM AND 8 PM. MADE A FEW MINOR ADJUSTMENTS TO THE
GOING FORECAST...BUT OVERALL TREND IS RIGHT ON TRACK.
&&
.SHORT TERM...(TODAY)
ISSUED AT 328 AM CDT SAT MAY 30 2015
LOW PRESSURE IS PROJECTED TO TRACK IN A NORTHEAST DIRECTION ACROSS
SOUTHEAST ILLINOIS TODAY, WITH A COLD FRONT PUSHING ACROSS ILLINOIS
FROM NW TO SE DURING THE DAY. BOTH FEATURES WILL PROVIDE A FOCUS FOR
AN EXTENDED PERIOD OF RAIN SHOWERS AND SCATTERED THUNDERSTORMS IN
CENTRAL AND SOUTHEAST ILLINOIS. AN INTENSIFYING SOUTHERLY LOW LEVEL
JET WILL PROGRESS ACROSS SOUTHERN IL AHEAD OF THE LOW...WITH SPEED
CONVERGENCE MAXIMIZED ON AN AXIS FROM SW TO NE ACROSS OUR FORECAST
AREA. THAT LLJ WILL AID IN MOISTURE TRANSPORT PUSHING PRECIP WATER
VALUES INTO THE 1.5 TO 2 INCH RANGE. FLASH FLOOD GUIDANCE FOR ONE
HOUR IS GENERALLY 2 TO 2.5 INCHES IN AREAS THAT ARE EXPECTED TO SEE
THE HIGHER PRECIP TOTALS. SOME CONCERN FOR A FLASH FLOOD WATCH
SOUTHEAST OF THE ILLINOIS RIVER, BUT MOST OF THAT AREA SHOULD BE
ABLE TO HANDLE THE RAINFALL THAT OCCURS WITH THIS SYSTEM. PEAK
INSTABILITY THIS AFTERNOON IS FORECAST TO REACH TO AROUND 1500 J/KG
MUCAPE SE OF I-55, WHICH WILL INCREASE RAINFALL RATES WITH STRONGER
UPDRAFT DEVELOPMENT. SEVERE STORMS ARE NOT EXPECTED, BUT A FEW
STORMS CLOSER TO THE TRACK OF THE LOW SE OF I-55 COULD SEE SOME
SMALL HAIL AND GUSTY WINDS.
HIGH TEMPS WILL BE HELD IN CHECK BY THE WIDESPREAD CLOUD COVER AND
PERIODIC RAIN. HIGHS WILL STRUGGLE TO REACH 70 AROUND GALESBURG,
WITH LOW 80S FOR 80S SE OF I-70 WHERE SOME PEEKS OF SUN MAY OCCUR
THIS MORNING TO HELP BOOST TEMPS.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 328 AM CDT SAT MAY 30 2015
SURFACE LOW PROJECTED TO RIDE JUST NORTH OF THE OHIO RIVER AND THEN
INTO CENTRAL INDIANA TONIGHT...WITH MOST OF THE MODELS FAVORING A
POSITION IN EAST CENTRAL INDIANA BY SUNDAY MORNING. SOME HEAVIER
RAINS SHOULD CONTINUE TO AFFECT EASTERN ILLINOIS INTO THE FIRST PART
OF THE EVENING WITH THIS TRACK...WHERE CATEGORICAL POP`S WILL BE IN
PLACE FOR THE FIRST FEW HOURS. WITH THE CHANGES TO THE TRACK...HAVE
HAD TO RE-ORIENT THE ORIGINAL POP GRIDS TO FAVOR A MORE WEST-EAST
TAPERING OF THE RAIN VS A CLEARING FROM THE NORTHWEST. THUS...POP`S
WILL LINGER EAST OF I-57 PAST MIDNIGHT. TOTAL QPF FOR TODAY AND
TONIGHT EXPECTED TO BE IN THE 1.5 INCH RANGE IN AREAS FROM EFFINGHAM
NORTHEAST TO DANVILLE. STIFF NORTH/NORTHEAST WIND WILL DRIVE IN MUCH
COOLER AIR INTO THE AREA...ALTHOUGH THERE WILL BE A TIGHT
TEMPERATURE GRADIENT ACROSS THE FAR EAST DEPENDING ON THE SPEED OF
THE DEPARTING LOW.
MUCH QUIETER WEATHER EXPECTED SUNDAY AND MONDAY IN THE WAKE OF THE
DEPARTING SYSTEM. SURFACE HIGH TO BUILD SOUTHWARD THROUGH THE GREAT
LAKES...AND WILL NOT BE IN ANY PARTICULAR HURRY TO LEAVE. GFS AND
ECMWF TAKE UNTIL LATE WEDNESDAY/EARLY THURSDAY TO PUSH THIS SYSTEM
INTO THE EASTERN GREAT LAKES REGION...RESULTING IN DRY CONDITIONS
FOR OUR AREA. IN FACT...THEY BASICALLY KEEP THINGS DRY UNTIL LATE
THURSDAY OR FRIDAY AS UPPER LEVEL HEIGHTS BUILD DUE TO HIGH PRESSURE
IN THE PLAINS. TEMPERATURES WILL START OFF RATHER COOL WITH HIGHS IN
THE 60S TO AROUND 70 SUNDAY AND MONDAY...BUT 80S SHOULD RETURN BY
MID WEEK AS THE HIGH PUSHES FARTHER EAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 700 AM CDT SAT MAY 30 2015
LOW PRESSURE APPROACHING FROM THE SW AND A COLD FRONT FROM THE NW
WILL COMBINE TO KEEP RAIN AND STORM CHANCES ACROSS ALL THE
TERMINAL SITES TODAY AND INTO THIS EVENING. LOCALLY HEAVY RAINFALL
WILL BE POSSIBLE, WITH PONDING OF WATER IN LOW SPOTS AT TIMES.
IFR/LIFR CLOUD HEIGHTS WILL AFFECT THE TERMINAL SITES AT LEAST
THIS MORNING, BUT POSSIBLY THROUGH THE AFTERNOON AS THE LOW
PRESSURE CROSSES SOUTHERN IL LATER TODAY AND IT PULLS MOISTURE AND
LOW CLOUDS INTO IL. PERIODS OF MVFR AND EVEN VFR COULD DEVELOP
BETWEEN RAIN AND STORMS TODAY, BUT OVERALL CLOUD HEIGHTS ARE
EXPECTED TO RETURN TO IFR/LIFR OVERNIGHT TONIGHT.
ONCE THE COLD FRONT PASSES TO THE SOUTHEAST OF THE TERMINAL SITES
THIS AFTERNOON, WINDS WILL SHIFT FROM SOUTHEAST TO NORTH-
NORTHEAST. WIND SPEEDS WILL INCREASE DRAMATICALLY AS THE LOW
CROSSES SOUTHEAST IL EARLY THIS EVENING, WITH SUSTAINED NORTH
WINDS OF 15-20KT AND GUSTS AROUND 3OKT. WIND GUSTS SHOULD DIMINISH
AFTER 06-08Z TONIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...SHIMON
LONG TERM...GEELHART
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
212 PM EDT SAT MAY 30 2015
.SYNOPSIS...
ISSUED AT 429 AM EDT SAT MAY 30 2015
A STRONG COLD FRONT WILL MOVE SOUTHEAST ACROSS THE AREA TODAY
CAUSING SHOWERS AND THUNDERSTORMS. RAIN WILL CONTINUE TONIGHT AND
SUNDAY MORNING AS A LOW PRESSURE SYSTEM MOVES NORTHEAST ALONG THE
FRONT. HIGHS TODAY WILL RANGE FROM THE LOWER 70S OVER SOUTHWEST
MICHIGAN TO THE LOWER 80S OVER NORTHWEST OHIO AND NORTHEAST
INDIANA WITH LOWS TONIGHT RANGING FROM THE UPPER 40S OVER SOUTHERN
MICHIGAN TO THE UPPER 50S OVER CENTRAL PORTIONS OF INDIANA AND
OHIO.
&&
.UPDATE...
ISSUED AT 210 PM EDT SAT MAY 30 2015
IN LIGHT OF WARM SECTOR DESTABILIZATION TRENDS THROUGH THIS MORNING
AND EXPANDING CONVN FM ERN IL THROUGH CNTRL IN AND IN REFLECTION OF
NR TERM HIGHRES GUIDANCE WILL HOIST FLOOD WATCH FOR A PORTION OF ERN
ZONES...GENERALLY INVOF AND EAST OF I-69.
VIS IMAGERY AND MESONET OBS INDICATE A LOOSELY DEFINED
OUTFLW/DIFFERENTIAL HEATING BOUNDARY HAD DVLPG FM NR KLAF TO KDFI
AHD OF EJECTING POTENT SRN STREAM SW LIFTING NEWD OUT OF MO
BOOTHILL. NR TERM HRRR GUIDANCE SUGGESTS ADDNL UPTICK AND
CONSOLIDATION OF ALG AND SOUTH OF A GUS>FWA>DFI LINE THROUGH THIS
EVENING. THUS GIVEN GOES SNDG DRIVED PWS APCHG 1.8" AND RAPIDLY
INCREASING FORCED ASCENT AHD OF APCHG UPR WAVE SEE LTL REASON WHY
HEAVY RAIN RATES IN CONVN WILL NOT MATERIALIZE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 429 AM EDT SAT MAY 30 2015
UPR LEVEL TROF OVER THE NRN PLAINS THIS MORNING EXPECTED TO MOVE
E-SE TO WI/IL BY SUNDAY MORNING. ASSOCIATED SFC CDFNT SHOULD DROP SE
ACROSS OUR CWA TODAY WITH VORT MAX/SFC WAVE OVER ARKANSAS LIFTING NE
INTO CENTRAL INDIANA TONIGHT. GENERALLY WK INSTABILITY EXPECTED
ACROSS THE AREA TODAY AS SHOWERS/CLOUD COVER LIMIT HEATING HWVR
MODERATE INSTABILITY MAY DEVELOP SE PORTION OF CWA WHERE FROPA WILL
HOLD OFF TIL THIS EVE. THIS COULD RESULT IN SOME STORMS WITH STRONG
GUSTY WINDS... THOUGH EXPECT ALL WILL REMAIN BLO SVR LEVELS GIVEN
LACK OF SGFNT DEEP LAYER SHEAR. POTENTIAL FOR HEAVY RAINFALL
AS SOME TRAINING OF ECHOES IN WARM/MOIST AIRMASS PSBL ALONG/AHEAD OF
THE FRONT TODAY AND EXTENSIVE POST FRONTAL RAINFALL ASSOCIATED
WITH UPR LEVEL JET DYNAMICS/MID LEVEL DEFORMATION ZONE TONIGHT.
00Z MODELS HAVE HEAVY QPF IN OUR AREA BUT DIFFER ON LOCATION.
PREFER NAM/ECMWF WITH HEAVIEST RAINFALL AXIS CLOSER TO FRONT
ACROSS NE INDIANA/SE MICHIGAN TONIGHT AS OPPOSED TO FARTHER NW
AXIS FCST BY GFS. IT HAS BEEN RATHER DRY ACROSS OUR AREA RECENTLY
AND RIVER FLOWS GENERALLY RUNNING BLO NORMAL IN OUR CWA SO WHILE
SOME FLOODING MAY BE PSBL OVER THE NEXT 24HRS... CONFIDENCE NOT
HIGH ENOUGH ATTM TO ISSUE A FLOOD WATCH. HIGHS TODAY EXPECTED TO
RANGE FROM THE L70S NW TO THE L80S SE... WITH TEMPS FALLING AFTER
FROPA... ESPECIALLY NW WITH SOME LAKE MICHIGAN ENHANCEMENT OF THE
CDFNT. WAVE RIDING ALONG FRONT TONIGHT SHOULD TEMPER CAA WITH LOWS
FCST TO RANGE FROM THE U40S NW TO THE U50S SE.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 429 AM EDT SAT MAY 30 2015
ENERGY CURRENTLY OVER ARKANSAS WILL EJECT SLOWLY NORTHEAST INTO THE
UPPER OHIO VALLEY BY SUNDAY MORNING. DEEPENING SFC WAVE WILL BE
MOVING NORTHEAST ALONG A STALLED BOUNDARY WITH AN AREA OF RAIN ALONG
AND NORTH OF THE TRACK. WHILE MODELS DO VARY ON POSITIONING OF
REMNANTS OF WHAT SHOULD BE A RATHER LARGE AREA OF
RAIN/RAINSHOWERS...THEY AT LEAST HAVE COME INTO SUFFICIENT AGREEMENT
TO NUDGED POPS UPWARDS MAINLY SE AND NE SUNDAY MORNING. BAROCLINIC
ZONE MAY BE SLOW TO SHIFT SE THROUGH THE DAY SO HAVE LEFT CHC POPS
IN SE AREAS INTO THE AFTERNOON. A FEW OF THE MODELS ATTEMPT TO BRING
MORE THAN AN INCH OF QPF SUNDAY MORNING TO SOME SPOTS. WITH PWATS
SLOWLY DECREASING AND SOMEWHAT PROGRESSIVE NATURE MODELS HAVE LEANED
TOWARDS MORE SUBDUED QPF GRIDS FROM SUPERBLEND OF MODELS. WITH THE
EXPECTED CLOUD COVER AND RAINFALL...MODEL GUIDANCE TANKED HIGHS BACK
INTO THE 50S IN SOME SPOTS NORTH OF THE LOW TRACK. TREND HAS BEEN
COLDER AND WILL CONTINUE IT AS A SLIGHTLY FASTER PACE. THIS COMBINED
WITH BREEZY CONDITIONS WILL MAKE FOR A BLUSTERY END TO MAY.
UPPER LEVEL WAVE WILL DIVE OUT OF CANADA INTO THE EASTERN GREAT
LAKES AND PHASES WITH REMNANTS OF UPPER OHIO VALLEY ENERGY. THIS
WILL KEEP COOL CONDITIONS IN PLACE MONDAY AND TUESDAY WITH BELOW
NORMAL HIGHS IN THE MID 60S TO MID 70S. INCREASING LOW LEVEL FLOW
AND WARMER TEMPERATURES WILL MOVE BACK INTO THE REGION FOR THE
MIDDLE AND LATTER PARTS OF THE WEEK. MODELS STILL ATTEMPTING TO
DEVELOP SHOWERS HERE AND THERE THURS INTO FRIDAY BUT NO REAL CLEAR
SIGNALS AT THIS TIME FOR MORE FOCUSED CHANCES AS WHAT DOES DEVELOP
MAY BE DIURNALLY BASED. WILL STICK WITH SLGT CHC TO CHC POPS FOR THE
TIME BEING WITH TEMPERATURES BACK NEAR/ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 210 PM EDT SAT MAY 30 2015
VFR CONDS TO BEING WILL DETERIORIATE QUICKLY THROUGH THIS EVENING
AHD OF POTENT NEWD EJECTING SW OUT OF THE MO BOOTHILL. EXPANDING
CONVN FM ERN IL INTO CNTRL IN SHLD STEADILY BRIDGE NWD THROUGH THIS
AFTN IN RESPONSE TO RAPIDLY INCREASING LL WAA ALTHOUGH DO XPC A MORE
SUBDUED THUNDER THREAT INVOF KSBN AS SFC CYCLONE TRACKS WELL SOUTH
THROUGH CNTRL IN. OTRWS WIDESPREAD IFR CONDS XPCD TO DVLP THROUGH
THIS EVENING AS WIDESPREAD RAIN DVLPS ACRS THE TERMINALS. IN
ADDN...WINDS XPCD TO VEER NERLY OVERNIGHT AND BECOME QUITE GUSTY IN
RESPONSE TO DEEPENING CYCLONE OVERHEAD W/SFC GUSTS TO 25KTS LIKELY
AFT 06Z.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLOOD WATCH THROUGH SUNDAY MORNING FOR INZ009-017-018-022>027-
032-033.
BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR INZ003.
MI...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR MIZ077.
OH...FLOOD WATCH THROUGH SUNDAY MORNING FOR OHZ001-002-004-005-015-
024.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR LMZ043-046.
&&
$$
UPDATE...T
SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...FISHER
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
319 PM MDT SAT MAY 30 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 155 PM MDT SAT MAY 30 2015
EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS SHOWS LARGE SCALE RIDGE
ACROSS THE SW US...WITH WESTERLY FLOW ACROSS THE PACIFIC
NORTHWEST. AXIS OF STRONG SUBSIDENCE/DRY AIR IS IN PLACE OVER OUR
CWA WITH SHORTWAVE RIDGE EXTENDING ACROSS THE CENTRAL ROCKIES INTO
THE NORTHERN PLAINS. AT THE SURFACE HIGH PRESSURE EXTENDS FROM
MANITOBA CANADA TO THE SOUTHERN PLANS OF THE US. THIS CANADIAN AIR
MASS HAS BROUGHT BELOW NORMAL TEMPERATURES AND A MUCH DRIER AIR
MASS TO OUR CWA
TONIGHT...SURFACE HIGH WILL BEGIN TO SLIDE EAST WITH LEE TROUGH
DEVELOPING LATE AS WEST/NORTHWEST FLOW BEGINS TO BUILD TOWARDS THE
CENTRAL ROCKIES. RESULT WITH BE SHIFT TO SE BL FLOW LATE TONIGHT
WHICH WILL BEGIN TO ADVECT GOOD BL MOISTURE INTO NORTH CENTRAL
KANSAS AND SOUTHWEST NEBRASKA. NAM/SREF/RAP ARE SHOWING POSSIBLE
FOG DEVELOPMENT INTO OUR EASTERN CWA LATE TONIGHT/EARLY SUNDAY
MORNING PARTICULARLY AROUND SUNRISE. SOUNDINGS TEND TO SUPPORT A
VERY SHALLOW MOIST LAYER THROUGH THE EARLY MORNING...SO I AM NOT
SURE WHAT KIND OF VISIBILITY RESTRICTIONS TO ANTICIPATE AT THIS
TIME. I INTRODUCED PATCHY FOG LATE TONIGHT/EARLY SUNDAY MORNING
FOR NOW.
SUNDAY...SOUTHERLY SURFACE GRADIENT BEGINS TO INCREASE OVER THE
CWA WITH INCREASING MIXING TO ABOUT 800MB BRINGING BREEZY WINDS
ACROSS THE CWA (GUSTS 30-35 MPH) AND GOOD WAA. CURRENTLY EXPECTING
SEASONAL HIGHS FROM THE UPPER 70S (EAST) TO THE MIDDLE 80S (WEST).
SURFACE TROUGH IN COLORADO COULD ACT AS A FOCUS FOR POSSIBLE
THUNDERSTORM DEVELOPMENT SUNDAY AFTERNOON AS AIR MASS DESTABILIZED
AND CAP WEAKENS. GUIDANCE SHOWS STRONG CINH IN NW KANSAS AND SW
NEBRASKA SUNDAY AFTERNOON...WITH CAP WEAKENING PRIMARILY ALONG
SURFACE TROUGH IN EASTERN COLORADO THROUGH THE AFTERNOON. TD
VALUES INCREASING TO NEAR 60F COULD RESULT IN CAPE VALUES
APPROACHING 2500 J/KG ALONG THE COLORADO STATE LINE. SHEER
APPEARS TO BE WEAK WITH 0-6KM BULK SHEER VALUES GENERALLY AROUND
20KT AND NO DIRECTIONAL SHEER TO SPEAK OF (OUTSIDE OF WEAK LOW
LEVEL VORTICITY ALONG SURFACE TROUGH IN COLORADO). CONSIDERING THE
AMOUNT OF CAPE A FEW STRONGER UPDRAFTS COULD CREATE A LIMITED
LARGE HAIL/STRONG WIND THREAT. SINCE COVERAGE IS EXPECTED TO BE
ISOLATED IN NATURE DUE TO LIMITED LARGE SCALE FORCING AND LACK OF
ORGANIZATION TO INDIVIDUAL CELLS I AM NOT ANTICIPATING A
WIDESPREAD THREAT OF SEVERE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 316 PM MDT SAT MAY 30 2015
MAIN FORECAST CONCERNS WILL BE PRECIPITATION CHANCES IN THE MID TERM
AND A RETURN TO AN ACTIVE PATTERN IN THE 4 TO 7 DAY. SATELLITE
SHOWING AN AMPLIFIED AND BLOCKY/COMPLICATED FLOW FROM THE CENTRAL
PACIFIC INTO EASTERN NORTH AMERICA.
MODELS STARTED OUT WELL AT THE JET AND MID LEVELS WITH A SLIGHT
ADVANTAGE TO THE GFS...UKMET...AND CANADIAN. THE NAM...ECMWF AND GFS
WERE DOING THE BEST ON THE SURFACE WIND AND PRESSURE FIELD. THE NAM
AND CANADIAN WERE DOING A LITTLE BETTER THAN THE GFS AND ECMWF ON
THE LOW LEVEL THERMAL FIELD.
SUNDAY NIGHT...INTERESTING AND COMPLICATED THUNDERSTORM FORECAST.
MID LEVEL RIDGE LOOKS A LITTLE FURTHER WEST THAN IT WAS YESTERDAY.
SURFACE TROUGH IS CLOSE TO THE WESTERN PORTION OF THE AREA EARLY IN
THIS PERIOD. FLOW ALOFT IS FROM THE NORTHWEST SO ONE WOULD THINK
THAT THE ACTIVITY SHOULD HAVE NO PROBLEM IN GOING SOUTHEAST. HOWEVER
MORE OF THE FORCING GOES NORTH AND THE LEAST ELEVATED CINH IS ALONG
THE NEBRASKA AND KANSAS BORDER. THAT FORCING AND WEAKNESS IN THE
INHIBITION SLIDES SOUTHEAST ACROSS THE AREA. SO HAVE SLIGHT TO
CHANCE POPS FROM THE WEST TO THE NORTH THEN INTO THE EASTERN PORTION
OF THE AREA. MODEL OUTPUT SHOWS HIGH BOUNDARY LAYER RH OVER MOST OF
THE AREA EAST OF THE COLORADO BORDER. AT THE VERY LEAST IT LOOKS
LIKE STRATUS BUT AM ALSO ANTICIPATING FOG.
MONDAY/MONDAY NIGHT...FOG SHOULD DISSIPATE BY LATE IN THE MORNING.
MODELS HAVE COOLED OFF TEMPERATURES FOR THE DAY BUT THERE IS STILL A
LOT OF DIFFERENCES. CONSIDERING THE MORNING STRATUS AND WINDS COMING
MORE FROM A SOUTHEAST DIRECTION...AM SIDING TOWARD COOLER.
MID/UPPER LEVEL RIDGE STARTS MOVING TO THE EAST IN THE AFTERNOON
INTO THE NIGHT. FLOW BECOMES MORE FROM A SOUTHERLY DIRECTION. SO
THERE IS SOME UNCERTAINTY AS TO HOW FAR EAST ANY STORMS WILL MAKE
IT. AS ON SUNDAY...SHORTWAVE AND SURFACE TROUGH ARE OVER OR NEAR THE
WESTERN PORTION OF OUR AREA...AND KEPT THE SLIGHT CHANCE IN THE FAR
WEST IN THE AFTERNOON.
THE ABOVE MENTIONED SHORTWAVE TROUGH MOVES NORTHEAST DURING THE
EVENING. SO HAVE A SLIGHT CHANCE TO CHANCE IN THE NORTHWEST HALF TO
TWO THIRDS. AFTER THAT WAVE PASSES ANOTHER SHORTWAVE TROUGH COMES IN
FROM THE SOUTHWEST LATE IN THE NIGHT. SO HAVE A SLIGHT CHANCE OVER
MOST OF THE AREA IN THE OVERNIGHT HOURS. ALSO THE BOUNDARY LAYER RH
COMES UP AGAIN AND HAVE INSERTED PATCHY FOG OVER MOST OF THE AREA.
TUESDAY...PATCHY FOG WILL BURN OFF IN THE MORNING. NEXT SHORTWAVE
COMES IN LATE IN THE DAY SO HAVE A SLIGHT CHANCE IN THE FAR WEST.
TEMPERATURES WILL BE WARMER BUT THAT WARMUP AGAIN WILL BE TEMPERED
BY SOUTHEASTERLY WINDS AND STRATUS.
TUESDAY NIGHT THROUGH SATURDAY...GENERAL PATTERN SHOWN BY THE MODELS
YESTERDAY CONTINUES TODAY. UPPER TROUGH DEVELOPS OVER THE WESTERN
PORTION OF THE COUNTRY WITH A CUT/CLOSED OFF LOW DEVELOPING
SOMEWHERE OVER/NEAR THE SOUTHWEST PORTION OF THE AREA. THIS DOES
SEEM OUT OF THE REALM OF POSSIBILITY DUE TO THE HIGHLY AMPLIFIED
RIDGE ALONG THE WEST COAST OF NORTH AMERICA.
OF COURSE THE DETAILS DIFFER BUT WITH TIME THOSE SHOULD BE RESOLVED.
IN GENERAL LEE TROUGH WILL BE NEAR THE COLORADO BORDER WITH
SOUTHERLY WINDS CONTINUING TO PULL IN LOW LEVEL MOISTURE. AT THE
SAME TIME MULTIPLE SHORTWAVE TROUGHS...SOME STRONGER THAN
OTHERS...ESPECIALLY TOWARD THE END OF THE PERIOD...WILL MOVE
THROUGH. CONSIDERING THIS...THIS TIME PERIOD LOOKS CONVECTIVELY
ACTIVE AND WET ONCE AGAIN. KNOW IT IS FAR OUT...BUT THE GEFS
PROBABILITIES FOR AT LEAST .05 ARE NEAR 100 PERCENT FOR ALL OR
PORTIONS OF THE FORECAST AREA. PATTERN DEFINITELY SUPPORTS IT.
SO A WET AND NOT VERY HOT PATTERN LOOK IN STORE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1119 AM MDT SAT MAY 30 2015
STRATUS DECK WITH HEIGHTS 1200-2500 AGL IS IN THE PROCESS OF
CLEARING OVER KGLD WITH VFR CONDITIONS EXPECTED THROUGH THE VALID
TAF PERIOD. VFR CONDITIONS WILL CONTINUE AT KMCK...THOUGH THERE
COULD BE A WINDOW FOR MVFR CIGS/VIS TO DEVELOP AROUND 12Z SUNDAY
MORNING AS SE FLOW BEGINS TO BRING BETTER LOW LEVEL MOISTURE INTO
NORTHCENTRAL KANSAS AND SOUTHWEST NEBRASKA. WITH SURFACE HIGH
PRESSURE IN PLACE WINDS WILL BEGIN TO DECREASE THIS
AFTERNOON/EVENING. SURFACE LOW PRESSURE BUILDING ACROSS EASTERN
COLORADO SUNDAY MORNING WILL RESULT IN WINDS SHIFTING TO THE SOUTH
AND INCREASING SUNDAY MORNING. GUSTS TO 25 KT WILL BE POSSIBLE AT
KGLD AND KMCK BY MIDDAY SUNDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
350 PM CDT SAT MAY 30 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 346 PM CDT SAT MAY 30 2015
SURFACE HIGH PRESSURE EXTENDING THROUGH THE CENTRAL HIGH PLAINS
REGION WILL BE THE DOMINATING INFLUENCE FOR SENSIBLE WEATHER LATE
TODAY AND TONIGHT. A CLOUD FREE SKY OTHER THAN SOME VERY THIN HIGH
CIRRUS IS PROBABLE AS SATELLITE HAS CONTINUED TO TREND THROUGH THE
DAY. WITH DRIER AIR IN PLACE, A COOLER OVERNIGHT IS FORECAST THAN
HAS BEEN SEEN IN PAST COUPLE OF WEEKS. CONSENSUS OF THE MODEL OUTPUT
SUPPORTS UPPER 40S TO ABOUT 50 DEGREES FOR MUCH OF THE FORECAST
AREA. THE NAM AND RAP13 ARE BOTH FAVORABLE FOR RADIATION FOG AFTER 9
UTC, HOWEVER THE RAP 13 DOES NOT EXTEND ANY FARTHER WEST THAN CENTRAL
KANSAS VERY PATCHY COVERAGE, WHILE THE NAM , WHICH IS OFTEN TOO
AGGRESSIVE, EXTENDS AREAS OF FOG MUCH FARTHER WEST INTO THE HIGHWAY
83 CORRIDOR. WOULD LIKE TO SEE SOME BETTER SUPPORT FROM THE LOCAL
GFS MOS, BUT MAY ADD SOME PATCHY FOG MENTION TO THE WX GRIDS IN THE
LOWER SURFACE DEWPOINT DEPRESSION AXIS ACROSS OUR NORTH CENTRAL
COUNTIES EARLY SUNDAY.
WITH SURFACE HIGH PRESSURE SLOWLY RETREATING, SURFACE WINDS
WILL AGAIN VEER TO THE SOUTH BY SUNDAY. THE NAM AND THE GFS ARE
QUITE DIFFERENT WITH RESPECT TO THE MAGNITUDE OF THE MOISTURE RETURN
ACROSS THE HIGHWAY 83-COLORADO BORDER CORRIDOR SUNDAY/SUNDAY
EVENING. THE MUCH MORE AGGRESSIVE NAM MODEL PERHAPS TOO RAPIDLY
SURGES DEW POINTS BACK INTO THE 60S LATE SUNDAY AND MID 60 BEYOND
THAT. NAM IS THE ONLY SCENARIO RIGHT NOW THAT WOULD BRING SURFACE
BASED CONVECTION FROM SE COLORADO INTO EXTREME SW KANSAS LATE SUNDAY
AFTERNOON, AND IF THE NAM WERE TO VERIFY, A SEVERE THREAT WOULD BE
POSSIBLE. HOWEVER AS OF THIS TIME NEITHER THE GFS OR THE ARW/NMM ARE
INDICATING CONVECTION IN THIS TIMEFRAME/AREA AND WILL LEAVE OUT FOR
THE UPCOMING SHORT TERM CONSENSUS PROCESS TO HANDLE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 346 PM CDT SAT MAY 30 2015
UPPER LEVEL RIDGING MOVES INTO THE PLAINS ON MONDAY INTO WEDNESDAY
WITH ONLY A SLIGHT CHANCE FOR THUNDERSTORMS SUNDAY NIGHT AND INTO
MONDAY MORNING. COULD ALSO HAVE SOME AREAS OF STRATUS EACH EARLY
MORNING FROM MONDAY MORNING INTO THURSDAY MORNING WITH SOUTHEAST
WINDS AND LOW LEVEL MOISTURE ADVECTION.
THE UPPER FLOW PATTERN AND MAIN STORM TRACK THEN SHIFTS TO THE NORTH
AND WEST OF THE REGION ACROSS THE INTERMOUNTAIN WEST AND NORTHERN
PLAINS, INTO NEXT WEEKEND. THE CHANCES FOR THUNDERSTORMS WILL BE
MAINLY ACROSS PARTS OF NORTHWEST KANSAS INTO PARTS OF SOUTH CENTRAL
KANSAS FRIDAY INTO SATURDAY.
LOWS WILL WARM FROM THE MID AND UPPER 50S SUNDAY NIGHT THEN INTO THE
60S THROUGH NEXT WEEKEND. HIGHS WILL BE MAINLY IN THE MID TO UPPER
80S THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 106 PM CDT SAT MAY 30 2015
SURFACE HIGH PRESSURE CONTINUES TO WEDGE SOUTHWARD INTO WESTERN KS,
DRYING OUT THE STRATUS LAYER WITH TIME AS SURFACE WARMING INCREASES.
SKIES WILL REMAIN CLEAR THROUGH TONIGHT WITH WINDS DROPPING TO
WELL BELOW 12 KNOTS AND VEERING TO A SOUTHERLY DIRECTION BY MIDDAY
SUNDAY. IT IS POSSIBLE STRATUS SHOULD BEGIN TO WORK ITS WAY BACK
NORTHWARD TOWARD THE GCK TERMINAL BY 15-18 UTC SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 346 PM CDT SAT MAY 30 2015
MINOR FLOODING ALONG CROOKED CREEK IN MEADE COUNTY CONTINUED THIS
AFTNEROON. HOWEVER THE STREAM HAS CROSSED BELOW THE FLOOD STAGE
RECENTLY AND THE WARNING IS CANCELED. UPSTREAM WATER ACROSS
CREEKS IN NORTHERN FORD AND SOUTHERN HODGEMAN COUNTIES COULD ADD
TO THE FLOW ON THE PAWNEE OVER THE NEXT DAY TO TWO AND WILL BE
CLOSELY MONITORED FOR REACTIONS DOWNSTREAM ON THE PAWNEE TOWARDS
LARNED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 77 58 83 / 0 0 10 10
GCK 49 79 59 84 / 0 0 10 10
EHA 54 82 60 90 / 0 10 10 10
LBL 49 79 60 87 / 0 10 10 10
HYS 45 76 56 82 / 0 0 30 30
P28 49 77 58 81 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...KRUSE
AVIATION...RUSSELL
HYDROLOGY...RUSSELL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
155 PM MDT SAT MAY 30 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 155 PM MDT SAT MAY 30 2015
EARLY AFTERNOON WV IMAGERY AND RAP ANALYSIS SHOWS LARGE SCALE RIDGE
ACROSS THE SW US...WITH WESTERLY FLOW ACROSS THE PACIFIC
NORTHWEST. AXIS OF STRONG SUBSIDENCE/DRY AIR IS IN PLACE OVER OUR
CWA WITH SHORTWAVE RIDGE EXTENDING ACROSS THE CENTRAL ROCKIES INTO
THE NORTHERN PLAINS. AT THE SURFACE HIGH PRESSURE EXTENDS FROM
MANITOBA CANADA TO THE SOUTHERN PLANS OF THE US. THIS CANADIAN AIR
MASS HAS BROUGHT BELOW NORMAL TEMPERATURES AND A MUCH DRIER AIR
MASS TO OUR CWA
TONIGHT...SURFACE HIGH WILL BEGIN TO SLIDE EAST WITH LEE TROUGH
DEVELOPING LATE AS WEST/NORTHWEST FLOW BEGINS TO BUILD TOWARDS THE
CENTRAL ROCKIES. RESULT WITH BE SHIFT TO SE BL FLOW LATE TONIGHT
WHICH WILL BEGIN TO ADVECT GOOD BL MOISTURE INTO NORTH CENTRAL
KANSAS AND SOUTHWEST NEBRASKA. NAM/SREF/RAP ARE SHOWING POSSIBLE
FOG DEVELOPMENT INTO OUR EASTERN CWA LATE TONIGHT/EARLY SUNDAY
MORNING PARTICULARLY AROUND SUNRISE. SOUNDINGS TEND TO SUPPORT A
VERY SHALLOW MOIST LAYER THROUGH THE EARLY MORNING...SO IM NOT
SURE WHAT KIND OF VISIBILITY RESTRICTIONS TO ANTICIPATE AT THIS
TIME. I INTRODUCED PATCHY FOG LATE TONIGHT/EARLY SUNDAY MORNING
FOR NOW.
SUNDAY...SOUTHERLY SURFACE GRADIENT BEGINS TO INCREASE OVER THE
CWA WITH INCREASING MIXING TO ABOUT 800MB BRINGING BREEZY WINDS
ACROSS THE CWA (GUSTS 30-35 MPH) AND GOOD WAA. CURRENTLY EXPECTING
SEASONAL HIGHS FROM THE UPPER 70S (EAST) TO THE MIDDLE 80S (WEST).
SURFACE TROUGH IN COLORADO COULD ACT AS A FOCUS FOR POSSIBLE
THUNDERSTORM DEVELOPMENT SUNDAY AFTERNOON AS AIR MASS DESTABILIZED
AND CAP WEAKENS. GUIDANCE SHOWS STRONG CINH IN NW KANSAS AND SW
NEBRASKA SUNDAY AFTERNOON...WITH CAP WEAKENING PRIMARILY ALONG
SURFACE TROUGH IN EASTERN COLORADO THROUGH THE AFTERNOON. TD
VALUES INCREASING TO NEAR 60F COULD RESULT IN CAPE VALUES
APPROACHING 2500 J/KG ALONG THE COLORADO STATE LINE. SHEER
APPEARS TO BE WEAK WITH 0-6KM BULK SHEER VALUES GENERALLY AROUND
20KT AND NO DIRECTIONAL SHEER TO SPEAK OF (OUTSIDE OF WEAK LOW
LEVEL VORTICITY ALONG SURFACE TROUGH IN COLORADO). CONSIDERING THE
AMOUNT OF CAPE A FEW STRONGER UPDRAFTS COULD CREATE A LIMITED
LARGE HAIL/STRONG WIND THREAT. SINCE COVERAGE IS EXPECTED TO BE
ISOLATED IN NATURE DUE TO LIMITED LARGE SCALE FORCING AND LACK OF
ORGANIZATION TO INDIVIDUAL CELLS I AM NOT ANTICIPATING A
WIDESPREAD THREAT OF SEVERE.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 228 AM MDT SAT MAY 30 2015
AT THE BEGINNING OF THE EXTENDED PERIOD MODELS SHOW A MID/UPPER
LEVEL TROUGH DEVELOPING OVER THE WESTERN UNITED STATES AND
GRADUALLY DEEPENING/AMPLIFYING TOWARDS THE END OF THE PERIOD. THE
POSITION OF THIS TROUGH WILL PRODUCE A PREDOMINANT SOUTHWEST FLOW
OVER THE TRI STATE AREA FOR THE WEEK. NUMEROUS SHORTWAVE TROUGHS
ARE EXPECTED TO MOVE ALONG THIS FLOW AND CROSS OUR REGION. AT THE
SAME TIME... ON THE SURFACE... ANTICIPATE LOW LEVEL MOISTURE BEING
BROUGHT IN BY SOUTH TO SOUTHEAST WINDS.
THIS PATTERN WILL HELP MAINTAIN HIGH TEMPERATURES IN THE LOW 80S
AND LOW TEMPERATURES IN THE MID 50S TO LOW 60S FOR THE REST OF THE
WEEK AND INTO THE WEEKEND. IT WILL ALSO PRODUCE A CHANCE OF
PRECIPITATION IN THE FORM OF SHOWERS AND THUNDERSTORMS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1119 AM MDT SAT MAY 30 2015
STRATUS DECK WITH HEIGHTS 1200-2500 AGL IS IN THE PROCESS OF
CLEARING OVER KGLD WITH VFR CONDITIONS EXPECTED THROUGH THE VALID
TAF PERIOD. VFR CONDITIONS WILL CONTINUE AT KMCK...THOUGH THERE
COULD BE A WINDOW FOR MVFR CIGS/VIS TO DEVELOP AROUND 12Z SUNDAY
MORNING AS SE FLOW BEGINS TO BRING BETTER LOW LEVEL MOISTURE INTO
NORTHCENTRAL KANSAS AND SOUTHWEST NEBRASKA. WITH SURFACE HIGH
PRESSURE IN PLACE WINDS WILL BEGIN TO DECREASE THIS
AFTERNOON/EVENING. SURFACE LOW PRESSURE BUILDING ACROSS EASTERN
COLORADO SUNDAY MORNING WILL RESULT IN WINDS SHIFTING TO THE SOUTH
AND INCREASING SUNDAY MORNING. GUSTS TO 25 KT WILL BE POSSIBLE AT
KGLD AND KMCK BY MIDDAY SUNDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BW
AVIATION...DR
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
340 PM EDT SAT MAY 30 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 340 PM EDT SAT MAY 30 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE PASSING THROUGH THE
MID MISSISSIPPI VALLEY AND INTO SOUTHERN INDIANA WHILE HIGH
PRESSURE HOLDS ON OVER THE SOUTHEAST PART OF THE NATION. THE
SOUTHEAST FLOW BETWEEN THESE FEATURES IS SUPPORTING WARM AND HUMID
CONDITIONS...THOUGH FAR EASTERN PARTS OF THE AREA ARE SEEING DRIER
DEWPOINTS DOWN INTO THE 50S. TEMPERATURES ARE GENERALLY IN THE
LOW TO MID 80S ACROSS THE AREA WITH DEWPOINTS...OUTSIDE OF THE
FAR EAST...IN THE MID 60S. WINDS ARE UP A BIT FROM YESTERDAY...
GENERALLY FROM THE SOUTH AT 5 TO 10 MPH WITH SOME GUSTS TO 15 AND
20 MPH. DESPITE REACHING CONVECTIVE TEMPERATURES...THE RADAR HAS
REMAINED RATHER QUIET THROUGH THE AFTERNOON.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL SHOW A BROAD TROUGH WORKING
INTO THE OHIO VALLEY WITH SEVERAL WAVES BRUSHING BY NORTHERN
KENTUCKY. THE SLIGHTLY LOWER HEIGHTS FROM THESE SHOULD SUPPORT
MORE IN THE WAY OF CONVECTIVE DEVELOPMENT INTO THIS EVENING AND
ON SUNDAY...GIVEN THE INSTABILITY THAT IS IN PLACE THIS AFTERNOON
AND WILL BUILD FOR MUCH OF THE AREA ON SUNDAY. HOWEVER...THE BEST
SUPPORT WILL BE TO THE NORTHWEST OF THE AREA INTO THIS EVENING AND
THEN PROBABLY MORE THROUGH SOUTHEAST KENTUCKY ON SUNDAY...IN
CONJUNCTION WITH THE COLD FRONT SETTLING INTO THIS PART OF THE
STATE. AS SUCH...HAVE FOLLOWED THE HIGHER RESOLUTION PROGS FROM
THE HRRR AND NAM12 THROUGH THE SHORT TERM PORTION OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE A WARM AND RELATIVELY QUIET EVENING
AS THE BETTER STORM COVERAGE HOLDS OFF TO THE NORTHWEST AND
TRIGGERS WILL BE HARD TO COME BY IN THE CWA. CANNOT RULE OUT A
STRAY SHOWER OR THUNDERSTORM AT ANYTIME OVERNIGHT GIVEN THE
APPROACH OF THE COLD FRONT...BUT MOST PLACES WILL STAY DRY.
SIMILARLY...WITH VARIABLE SKY COVER...PATCHY VALLEY FOG CAN BE
EXPECTED LATER TONIGHT...BECOMING LOCALLY DENSE. MOST OF THE
MODELS HAVE THE FRONT PUSHING DOWN INTO EAST KENTUCKY EARLY SUNDAY
AND MAINLY DRY BEFORE BECOMING MORE ACTIVE IN THE FAR SOUTHEAST
LATER SUNDAY AFTERNOON. THE CONVECTION SHOULD LINGER THROUGH THE
EVENING AND EVEN REMAIN A THREAT INTO THE NIGHT AS THE FRONT
STALLS OVER THE AREA. DUE TO THAT BOUNDARY...HAVE KEPT POPS
HIGHER INTO SUNDAY NIGHT THAN WHAT ONE WOULD TYPICAL EXPECTED FOR
A MORE DIURNALLY DRIVEN PATTERN. AGAIN SUNDAY NIGHT...PATCHY
VALLEY FOG CAN BE EXPECTED LATE AT NIGHT. FOR ANY STORM THROUGH
THE SHORT TERM...STRONG GUSTY WINDS WILL BE POSSIBILITY GIVEN THE
MODERATE INSTABILITY AND SOME MID LEVEL WIND SUPPORT. WILL
CONTINUE TO MENTION THIS CONCERN IN THE HWO.
ONCE AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE
T/TD/WIND GRIDS INTO SUNDAY BEFORE SWITCHING TO THE SUPERBLEND
THROUGH 12Z MONDAY. AGAIN MADE SOME MINOR RIDGE TO VALLEY
TEMPERATURE ADJUSTMENTS FOR LOWS AND HOURLY TEMPS BOTH NIGHTS...
COOLER IN THE VALLEYS TONIGHT...MILDER ON SUNDAY NIGHT. AS FOR
POPS...ENDED UP CLOSE TO A BLEND OF THE MAV AND MET MOS THROUGH
THE SHORT TERM...THOUGH SUBSTANTIALLY LOWER THAN THE RATHER WET
MET NUMBERS AT JKL EACH PERIOD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 155 PM EDT SAT MAY 30 2015
FORECAST REMAINS VERY UNCERTAIN HEADING INTO NEXT WEEK AS A FRONTAL
BOUNDARY WILL LIKELY STALL OVER OR NEAR EASTERN KENTUCKY...SETTING
UP A CLASH OF AIR MASSES THROUGH NEXT WEEK. THIS WILL LIKELY RESULT
IN A GOOD SPREAD IN TEMPERATURES/DEWPOINTS/RAIN CHANCES FROM NORTH
TO SOUTH THROUGH THE WEEK. OF COURSE MODELS CONTINUE TO FLIP FLOP
ON ACTUAL PLACEMENT OF THIS FRONT WITH THE 12Z MODEL SUITE TRENDING
BACK TOWARDS A WETTER FORECAST FOR THE UPCOMING WEEK AS THE BOUNDARY
STAYS MORE OVER EASTERN KENTUCKY INSTEAD OF SHIFTING OFF TO THE
SOUTH. IN FACT...MONDAY NOW LOOKS MUCH WETTER AS THE BOUNDARY
SETTLES SOUTH OVER EASTERN KENTUCKY AS A SHORTWAVE TROUGH PUSHES
ACROSS THE AREA MONDAY. THUS...WILL RAMP UP POPS TO CHANCE/LIKELY
WITH A GRADIENT OF HIGHER POPS IN THE SOUTHEAST...TO LESSER POPS TO
THE NORTHWEST. SHOWER/STORM CHANCES SHOULD DECREASE INTO MONDAY
NIGHT WITH THE LOSS OF INSTABILITY. HOWEVER...WITH THE FRONTAL
BOUNDARY SETTLING OVER THE AREA WITH SUBTLE SHIFTS NORTH OR SOUTH
THROUGH THE WEEK...HAVE OPTED TO GO WITH SLIGHT CHANCE POPS EACH
AFTERNOON/EVENING TO ACCOUNT FOR DIURNALLY DRIVEN SHOWERS AND
STORMS. WE SHOULD SEE A LULL THROUGH EACH OVERNIGHT PERIOD WITH THE
LACK OF INSTABILITY...ALTHOUGH A STRAY SHOWER COULD STILL BE
POSSIBLE. HAVE OPTED TO STAY AWAY FROM ANY HIGHER POPS FOR NOW GIVEN
THE UNCERTAINTY IN THE FORECAST AND LACK OF ANY SIGNIFICANT WAVES.
THE COMING WEEK WILL FEATURE A DIFFICULT TEMPERATURES FORECAST
PENDING THE FRONTAL POSITION EACH DAY...BUT POTENTIAL EXIST THAT WE
COULD SEE TEMPERATURES FAIRLY CLOSE TO NORMAL FOR SOME OF THE AREA
AS CLOUDS AND ANY SHOWERS/STORMS WILL KEEP HIGH TEMPERATURES IN
CHECK. LOWS COULD FALL INTO THE 50S IN SOME AREAS EARLY NEXT
WEEK...IF THE FRONT CAN PUSH FAR ENOUGH SOUTH. REGARDLESS...THOSE
WITH OUTDOOR PLANS WILL WANT TO CHECK BACK ON THIS FORECAST AS
CONFIDENCE REMAINS LOW ON THE FORECAST PAST MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 215 PM EDT SAT MAY 30 2015
CU DEVELOPMENT AND SCATTERED SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO BE ON TAP THROUGHOUT THE REST OF THE AFTERNOON AND
INTO THE FIRST PART OF THE EVENING. THE EXACT LOCATION AND TIMING
OF THE STORMS IS TOUGH TO DISCERN SO HAVE CONTINUED THE MENTION
OF VCTS FOR THE HOURS WHEN THEY ARE MOST LIKELY TO OCCUR ACROSS
THE AREA. DAYTIME MIXING WILL ALSO ALLOW SOME DECENT WIND GUSTS IN
THE 15 TO 20 KT RANGE DURING THE LATTER PART OF THE AFTERNOON. BY
EVENING...THE CONVECTION WILL BEGIN A DOWNWARD TREND AS WE LOSE
THE BEST INSTABILITY AND HEATING. WINDS WILL ALSO DIMINISH...WITH
PATCHY VALLEY FOG AGAIN SETTING UP. UNLESS RAIN DIRECTLY AFFECTS A
TAF SITE THROUGH THIS EVENING...EXPECT MOST OF THE FOG TO REMAIN
IN THE VALLEYS AND NOT AFFECT ANY TAF AIRPORT. THE APPROACHING
COLD FRONT WILL KEEP A SMALL CHANCE OF SHOWER IN THE FORECAST
THROUGH THE NIGHT WITH A VCSH IN PLACE. LATER ON SUNDAY...THE
NEARBY BOUNDARY WILL KEEP THUNDERSTORMS A POSSIBILITY SO HAVE
INCLUDED A VCTS FOR THIS AS WELL. WINDS WILL BE FROM THE SOUTH TO
SOUTHWEST DURING THE DAYTIME HOURS AT 5 TO 10 KTS...WITH
OCCASIONAL HIGHER GUSTS...AND LIGHT/VARIABLE AT NIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
215 PM EDT SAT MAY 30 2015
.UPDATE...
ISSUED AT 200 PM EDT SAT MAY 30 2015
STILL WAITING FOR THE BETTER CONVECTION TO DEVELOP ACROSS EAST
KENTUCKY THIS AFTERNOON. THE HRRR HAS NOW BACKED OFF ITS
EASTERNMOST SPROUTINGS SO HAVE GONE BACK TO MAINLY A NORTHWEST TO
SOUTHEAST GRADIENT TO THE POPS AND WX THROUGH THE REST OF THE
DAY...IN THE GRIDS. OTHERWISE...JUST TOUCHED UP THE T/TD ONES PER
THE LATEST SHORTBLEND GUIDANCE...OBS...AND TRENDS. THESE HAVE BEEN
SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1100 AM EDT SAT MAY 30 2015
14Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE EAST STILL HOLDING
SOME INFLUENCE OVER FAR EASTERN KENTUCKY WHILE AN AREA OF LOW
PRESSURE IS MOVING INTO THE MID MISSISSIPPI VALLEY. THE PRESSURE
GRADIENT BETWEEN THESE FEATURES IS RESULTING IN A CONTINUED FLOW
OF WARM AND MOIST AIR INTO EASTERN KENTUCKY. SPECIFICALLY...
READINGS ARE NOW IN THE MID TO UPPER 70S THROUGH THE AREA WHILE
DEWPOINTS HOLD IN THE MID 60S FOR MOST PLACES ALONG WITH SOUTH
WINDS AT 5 TO 10 KTS. A BIT MORE IN THE WAY OF LOW AND MID LEVEL
CLOUDS OVERNIGHT HELPED TO LIMIT THE FOG DEVELOPMENT THIS MORNING
AND NOW ALL THAT IS GONE...WHILE PARTLY CLOUDY CONDITIONS REMAIN.
A ROGUE AREA OF SHOWERS MOVED NORTH THROUGH THE CUMBERLAND VALLEY
EARLIER IN THE MORNING...THOUGH THESE HAVE NOW DISSIPATED. BASED
ON THE LATEST HRRR AND INCOMING NAM12...ALONG WITH DIURNAL
CLIMATOLOGY... EXPECT SCATTERED CONVECTION TO REDEVELOP OVER THE
AREA SHORTLY AFTERNOON. THE BETTER COVERAGE SHOULD BE CONCENTRATED
OVER OUR WESTERN COUNTIES LATE IN THE DAY CLOSER TO THE SFC LOW
AND IS SLOWLY APPROACHING FRONT. HOWEVER...THE HRRR IS MORE
INSISTENT THAT CONVECTION IS EQUALLY POSSIBLE FURTHER EAST AND
GIVEN THIS ENVIRONMENT...OF INCREASING INSTABILITY AND NO
CAPPING...WILL NOT RULE IT OUT. ACCORDINGLY...HAVE BROUGHT HIGH
CHANCE POPS A BIT FURTHER EAST WITH THIS UPDATE. ANY STORMS THAT
DEVELOP COULD BECOME STRONG WITH ENOUGH WIND SHEAR ALOFT TO
SUGGEST A POTENTIAL FOR STRONGER WIND GUSTS THAN WE SAW YESTERDAY.
THE ENTIRE AREA REMAINS IN A MARGINAL RISK FOR JUST THAT FROM SPC
WHILE A SLIGHT RISK OUTLOOK IS FOUND JUST TO OUR NORTHWEST. ANY
LATE DAY STORM WILL NEED TO BE MONITORED CLOSELY FOR SEVERE
POTENTIAL. THE UPDATED GRIDS...INCLUDING ADJUSTMENTS TO THE T/TD
GRIDS PER THE LATEST SHORTBLEND GUIDANCE...OBS...AND TRENDS...
HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. IN ADDITION...A
TOUCHED UP SET OF ZONES...MAINLY REMOVING THE MORNING FOG
WORDING...HAS BEEN SENT.
UPDATE ISSUED AT 739 AM EDT SAT MAY 30 2015
FOG IS LIFTING ACROSS THE REGION AS THE SUN BEGINS TO RISE. A FEW
LOCATIONS IN THE EAST ARE STILL REPORTING VIS BELOW 2 MILES. AS A
RESULT...UPDATED THE WEATHER GRIDS TO TAKE OUT FOG IN THE WESTERN
CWA...AND THE DENSE FOG IN THE EAST. FOG WILL CONTINUE TO LIFT
AND DISSIPATE ACROSS THE EAST OVER THE NEXT HOUR OR TWO...SO LEFT
IN FORECAST THROUGH 12Z. ALSO...RAIN SHOWERS ARE ALREADY STARTING
TO DEVELOP ACROSS PORTIONS OF EASTERN KY...MOVING NNE. ALSO
UPDATED POPS AND WEATHER GRIDS TO REFLECT THE EARLIER ONSET OF
CONVECTION. ONCE THE LATEST OBSERVATIONS WERE INGESTED INTO THE
DATABASE...LOADED THESE INTO THE FORECAST TO MAKE SURE CURRENT
CONDITIONS WERE WELL REFLECTED IN THE NEAR TERM FORECAST.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 418 AM EDT SAT MAY 30 2015
AFTER RAINS IMPACTED SECTIONS OF THE CWA YESTERDAY...LINGERING
MOISTURE HAS LED TO DECENT AREAS OF FOG DEVELOPMENT DURING THE
OVERNIGHT HOURS. PATCHY DENSE FOG HAS ALSO BEEN OBSERVED...AND
WILL LIKELY CONTINUE THROUGH THE EARLY MORNING HOURS. AS THE SUN
BEGINS TO RISE THIS MORNING...EXPECT FOG TO LIFT AND GIVE WAY TO
MOSTLY TO PARTLY SUNNY SKIES ACROSS THE REGION THIS MORNING.
UPPER LEVEL RIDGING OFF THE SOUTHEAST ATLANTIC CONUS WILL SLOWLY
BREAK DOWN OVER THE NEXT DAY AS TROUGHING OVER THE MISSISSIPPI RIVER
VALLEY SHIFTS EASTWARD AND ACROSS THE OHIO RIVER VALLEY. THIS SHIFT
WILL BE OUR PRIMARY WEATHER DRIVER OVER THE NEXT 2 DAYS. AT THE
SURFACE...A LOW PRESSURE SYSTEM...CURRENTLY MOVING ACROSS
MISSOURI...WILL REACH WESTERN INDIANA BY THIS EVENING...THEN
CONTINUE TO SHIFT NORTHEAST...JUST NORTH OF THE OHIO
RIVER...THROUGH SATURDAY NIGHT AND INTO SUNDAY MORNING. AS THIS
OCCURS...A COLD FRONT IS EXPECTED TO PUSH THROUGH KENTUCKY. STILL
FAVORING THE GFS SOLUTION OF THE FRONTAL PASSAGE...WHICH SHOULD
TRAVERSE WESTERN KY LATE TONIGHT...CENTRAL KY THROUGH 12Z
SUNDAY...AND STALL OUT ACROSS THE HIGH TERRAIN OF KY BETWEEN 18Z
SUNDAY AND 0Z MONDAY.
FOR TODAY...CONTINUED STRONG WARM MOIST SOUTHERLY FLOW AHEAD OF THE
BOUNDARY WILL BRING YET ANOTHER HIGH HUMIDITY/WARM WEATHER DAY TO
THE REGION...AS WELL AS THE POTENTIAL FOR CONVECTIVE DEVELOPMENT. AS
HAS BEEN THE CASE IN THE PREVIOUS DAYS...BEST CHANCES FOR CONVECTION
WILL BE IN THE AFTERNOON WITH PEAK HEATING AND INSTABILITY. LATEST
FORECAST SOUNDINGS FOR TODAY DON/T LOOK OVERLY IMPRESSIVE FOR SEVERE
POTENTIAL...BUT COULD STILL SEE SOME GOOD RAINERS AND DECENT
LIGHTNING FROM ANY THUNDERSTORM THAT DEVELOPS. AS WE LOSE DAYTIME
HEATING...EXPECT COVERAGE TO DECREASE INTO THE OVERNIGHT
HOURS...ESPECIALLY IN THE SE PORTION OF THE CWA AWAY FROM THE BEST
FORCING OF THE INCOMING FRONT. BEGAN INCREASING POPS AGAIN BY 12Z
SUNDAY AS SUN BEGINS TO INFLUENCE UNSTABLE AIRMASS ONCE
MORE...PEAKING AS THE FRONT BEGINS PASSING OVER DURING THE AFTERNOON
HOURS. FORECAST SOUNDINGS ARE SHOWING BETTER HAIL POTENTIAL DURING
THE DAY SUNDAY...WITH MUCH MORE DRYING ALOFT AND DECENT CAPE VALUES
IN THE 2 TO 3K J/KG RANGE. LAPSE RATES ARE NOT SUPER
IMPRESSIVE...BUT LI/S WILL DROP INTO THE -5 TO -6C RANGE IN SOME
LOCATIONS...INDICATING GOOD POTENTIAL FOR THUNDERSTORM INITIATION.
ALL IN ALL...EXPECT SOME DECENT SCATTERED STORM DEVELOPMENT TO
POTENTIALLY TAKE PLACE OVER SOUTHEAST KY...WHICH CORRESPONDS WELL TO
SPC/S MARGINAL RISK OVER THIS SAME AREA FOR SUNDAY. SOMETHING TO
WATCH OUT FOR. HOWEVER...DID NOTE THE LEVEL OF MOISTURE IN THE
SOUNDINGS ARE QUITE SHALLOW...WITH UNIMPRESSIVE PWATS...SO NOT
EXPECTING MUCH HYDRO CONCERNS...UNLESS STORMS CONTINUE TO IMPACT THE
SAME LOCATIONS MULTIPLE TIMES.
WITH SUCH A STRONG SOUTHERLY FLOW EXPECTED TODAY...TEMPERATURES
COULD WARM WELL INTO THE MID 80S ACROSS MUCH OF THE REGION...WITH
CONTINUED HIGH HUMIDITY VALUES. HOWEVER...WITH INCREASED CLOUD COVER
OVERNIGHT AND INTO TOMORROW...AS WELL AS WINDS SHIFTING TO A MORE NW
DIRECTION BEHIND THE FRONT...EXPECT TEMPERATURES TO ONLY REACH THE
UPPER 70 TO LOW 80 RANGE FOR DURING THE DAY SUNDAY /COOLEST IN THE
WEST/. OVERALL...SUPERBLEND AND GFS WERE THE MODELS OF CHOICE DURING
THE SHORT TERM...THOUGH MOST SHORT TERM MODELS SEEMED TO BE IN
DECENT AGREEMENT WITH ONE ANOTHER.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 418 AM EDT SAT MAY 30 2015
THE EXTENDED FORECAST PERIOD BEGINS ON SUNDAY NIGHT WITH A PRETTY
ACTIVE AND PROGRESSIVE PATTERN IN PLACE. AS AN UPPER LOW BEGINS TO
EXIT THE OH VALLEY AREA AND A COLD FRONT PUSHES THROUGH THE AREA.
THE FRONT DOES WASH OUT A BIT AND INSTABILITY WILL BEGIN TO BECOME
TIED TO DIURNAL TRENDS BUT WILL KEEP POPS THROUGH THE SUNDAY NIGHT
PERIOD AND TRANSITION TO SLIGHT CHANCE POPS INTO MONDAY AFTERNOON.
TEMPERATURES REALLY COOL OFF WITH LOWER 70S EXPECTED WITH THE
APPROACHING COOLER AIR MASS. THE FRONT THEN BECOMES A STALLED
BOUNDARY ALONG THE KY/TN BORDER AND ALONG THE VA/KY BORDER AND SO
WILL KEEP SLIGHT CHANCE POPS EACH DAY ALONG THE HIGH TERRAIN AREAS
THERE. THIS WILL BE THE CASE EACH DAY FROM MONDAY THROUGH
WEDNESDAY WITH THE MAX CHANCE OCCURRING EACH DAY DURING THE
AFTERNOON BUT DID GO BELOW THE SUPER BLEND SOLUTION WITH THE LACK
OF UPPER LEVEL SUPPORT AND COLLABORATION WITH THE NEIGHBORING
OFFICES.
BY THURSDAY...WITH AN INCREASED SOUTHERLY FLOW...A WEAK WAVE
OVERHEAD...AND THE MENTIONED STATIONARY BOUNDARY...A BETTER CHANCE
FOR PRECIP WILL BE ON TAP FRO THURSDAY AFTERNOON AND FRIDAY
AFTERNOON. THIS PERIOD WILL STILL MAINTAIN A DIURNAL TREND TO ANY
CONVECTION. STILL KEPT CLOSE TO THE SUPER BLEND SOLUTION BUT DID
NUDGE POPS BELOW A BIT DURING THE FEW DAYS WITH LACK OF UPPER
LEVEL SUPPORT. OVERALL...BESIDES THE EXITING COLD FRONT ON SUNDAY
NIGHT...NO DOMINANT WEATHER FEATURE WILL PROVIDE A DEFINITE CHANCE
OF PRECIP OR AT LEAST THE LACK OF CONSISTENCY IN THE MODELS IS
SUCH THAT NOTHING ABOVE SLIGHT CHANCE POPS IS DISCERNIBLE. FOR
THIS FACT...DID STAY RATHER CLOSE TO THE SUPER BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 215 PM EDT SAT MAY 30 2015
CU DEVELOPMENT AND SCATTERED SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO BE ON TAP THROUGHOUT THE REST OF THE AFTERNOON AND
INTO THE FIRST PART OF THE EVENING. THE EXACT LOCATION AND TIMING
OF THE STORMS IS TOUGH TO DISCERN SO HAVE CONTINUED THE MENTION
OF VCTS FOR THE HOURS WHEN THEY ARE MOST LIKELY TO OCCUR ACROSS
THE AREA. DAYTIME MIXING WILL ALSO ALLOW SOME DECENT WIND GUSTS IN
THE 15 TO 20 KT RANGE DURING THE LATTER PART OF THE AFTERNOON. BY
EVENING...THE CONVECTION WILL BEGIN A DOWNWARD TREND AS WE LOSE
THE BEST INSTABILITY AND HEATING. WINDS WILL ALSO DIMINISH...WITH
PATCHY VALLEY FOG AGAIN SETTING UP. UNLESS RAIN DIRECTLY AFFECTS A
TAF SITE THROUGH THIS EVENING...EXPECT MOST OF THE FOG TO REMAIN
IN THE VALLEYS AND NOT AFFECT ANY TAF AIRPORT. THE APPROACHING
COLD FRONT WILL KEEP A SMALL CHANCE OF SHOWER IN THE FORECAST
THROUGH THE NIGHT WITH A VCSH IN PLACE. LATER ON SUNDAY...THE
NEARBY BOUNDARY WILL KEEP THUNDERSTORMS A POSSIBILITY SO HAVE
INCLUDED A VCTS FOR THIS AS WELL. WINDS WILL BE FROM THE SOUTH TO
SOUTHWEST DURING THE DAYTIME HOURS AT 5 TO 10 KTS...WITH
OCCASIONAL HIGHER GUSTS...AND LIGHT/VARIABLE AT NIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JMW
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
205 PM CDT SAT MAY 30 2015
.DISCUSSION...
REMNANT COLD POOL BOUNDARY AND CONVECTION ARE CURRENTLY EXITING
OUR EXTREME EASTERN PARISHES THIS AFTN. THE BOUNDARY HAS WORKED
OVER OUR ATMOSPHERE PRETTY GOOD TODAY BUT REMNANT MCV CONTINUES TO
SPIN ACROSS NE TX ATTM. STARTING TO SEE SOME AIRMASS RECOVERY
ACROSS CENTRAL TEXAS AND EVEN STARTING TO SEE SOME NEW DEVELOPMENT
ALONG AND NORTH OF THE I-20 CORRIDOR IN NORTH CENTRAL TX CLOSER TO
THE MCV ITSELF. WITH LOW CINH IN PLACE NOT TO MENTION THE
MOISTURE... HAVE DECIDED TO LEAVE THE FFA IN PLACE THROUGH 7 PM
THIS EVENING. THE HRRR DOES DEVELOP ADDITIONAL SCATTERED
THUNDERSTORM ACTIVITY IN THE VICINITY OF THE FILLING MCV THIS
EVENING AND TRIES TO GENERATE ADDITIONAL ACTIVITY SOUTH OF THE
I-20 CORRIDOR AND THIS SEEMS PLAUSIBLE AS THIS AREA WAS MOSTLY
MISSED BY PREVIOUS DAYTIME CONVECTION. DID NOT EXPAND THE WATCH TO
INCLUDE DEEP EAST TEXAS OR THE REST OF NORTHERN LOUISIANA AS AREAS
ALONG AND SOUTH OF THE I-20 CORRIDOR HAVE MISSED OUT ON RAINFALL
OVER THE LAST 3 DAYS...AT LEAST THE SOUTHERN HALF OF NE TX HAS AND
FOR THAT REASON...THEY SHOULD BE ABLE TO TAKE A GOOD INCH TO TWO
INCH RAIN IF THEY DO SEE THAT THIS EVENING. COLD FRONT AS OF 18Z
WAS ANALYZED FROM NW AR INTO SOUTHERN OK/N CENTRAL TX AND THIS
FEATURE SHOULD MAKE GOOD PROGRESS INTO SW AR/NW LA AND NE TX
OVERNIGHT.
MAIN UPPER TROUGH AXIS SHOULD EXTEND FROM THE GREAT LAKES REGION
INTO THE SOUTHERN PLAINS LATE TONIGHT...WITH THIS FEATURE MOVING
SLOWLY INTO EASTERN OK/WESTERN AR BY MIDDAY SUN AND INTO THE TENN
VALLEY BY MIDDAY MON. THIS TROUGH AXIS WILL HELP TO FOCUS ADDITIONAL
SHOWER AND THUNDERSTORM ACTIVITY ON SUNDAY BUT COVERAGE SHOULD BE
MOSTLY SCATTERED IN NATURE AND MORE FOCUSED ALONG AND TO THE EAST
OF THE REMNANT COLD FRONT WHICH MAY STALL LATE TNGT/SUN ACROSS OUR
SE ZONES. KEPT POPS HIGHEST IN OUR SE ZONES FOR SUN THROUGH
MONDAY. THE TROUGH APPEARS TO BECOME CUTOFF FROM THE WESTERLIES ON
TUESDAY EAST OF OUR REGION AND THAT SHOULD KEEP THE ANY PRECIP
EAST OF OUR REGION AS WELL. EXTENDED PORTION OF THE FORECAST
BEYOND TUE IS A DRY ONE WITH BELOW NORMAL TEMPERATURES EARLY
IN THE WEEK...GRADUALLY WARMING TO NEAR SEASONAL NORMS BY MID TO
LATE WORK WEEK.
THANKS FOR THE COORDINATION TODAY SURROUNDING OFFICES...PRELIMS
TO FOLLOW...13.
&&
.PREV DISCUSSION... /ISSUED 138 PM CDT SAT MAY 30 2015/
AVIATION...
FIRST ROUND OF CONVECTION NOW MAKING ITS WAY THROUGH KMLU...WITH
REDEVELOPMENT OVER E TX POSSIBLE THROUGH THIS AFTERNOON. DUE TO
THE UNCERTAINTY WITH REGARD TO COVERAGE...WILL HANDLE WITH VCTS
AND AMD FOR TEMPO GROUPS AS NECESSARY. VFR EXPECTED TO PREVAIL
OUTSIDE OF TSTMS...HOWEVER. CONVECTION WILL LIKELY COME TO AN END
AS A COLD FRONT MOVES THROUGH THE REGION TONIGHT. OTHERWISE...
MVFR/IFR CIGS/VSBYS ARE EXPECTED DURING THE WEE HOURS OF THE
MORNING AS MOISTURE WRAPS AROUND THE BACK SIDE OF THE UPPER LOW.
CIGS SHOULD LIFT BY MID TO LATE MORNING. EXPECT LIGHT/VRB WINDS
TODAY TO GIVE WAY TO N TO NWLY WINDS AT 5-10 KTS AFTER FROPA. /12/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 63 81 63 81 / 40 20 10 20
MLU 66 82 63 80 / 50 40 30 30
DEQ 55 78 59 78 / 40 20 10 20
TXK 60 79 61 79 / 40 20 10 20
ELD 62 80 60 79 / 40 30 20 30
TYR 62 80 61 81 / 40 20 10 20
GGG 62 80 62 81 / 40 20 10 20
LFK 65 82 63 83 / 50 30 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR ARZ050-051-
059>061-070-071.
LA...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR LAZ001-002.
OK...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR OKZ077.
TX...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR TXZ096-097-
108>112-124>126-136>138-149>151.
&&
$$
13
AREA FORECAST DISCUSSION
NWS CARIBOU ME
624 PM EDT SAT MAY 30 2015
.SYNOPSIS...
A COLD FRONT WILL ENTER THE REGION THIS EVENING AND SLOWLY MOVE
ACROSS THE FORECAST AREA TONIGHT AND SUNDAY. THE FRONT WILL RETURN
NORTHWARD AS A WARM FRONT MONDAY AND LOW PRESSURE WILL CROSS THE
STATE TUESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
624 PM UPDATE...THUS FAR THE ACTIVITY THAT HAS MOVED ACROSS
PORTIONS OF AROOSTOOK...NORTHERN SOMERSET...AND NORTHERN
PISCATAQUIS COUNTIES HAS NOT BEEN IMPRESSIVE AND HAS GENERALLY
WEAKENED AS IT HAS MOVED EAST. STILL THE POTENTIAL FOR THE NEXT
COUPLE OF HOURS THAT ANY LINE SEGMENTS THAT ENTER THE CWA FROM THE
WEST COULD CONTAIN GUSTY WIND...BUT THE THREAT OF SEVERE WEATHER
IS DIMINISHING. THE BEST SFC BASED AND MU CAPES AND SHEAR WILL
REMAIN ACROSS THE NW THIRD OF CWA THROUGH EARLY THIS EVENING WITH
CONDITIONS TO STABILIZE LATER THIS EVE WITH THE LOSS OF DAYTIME
HEATING. ONLY MINOR TWEAKS TO THE ONGOING FORECAST BASED ON THE
LATEST RADAR TRENDS.
PREVIOUS DISCUSSION...
ATMOSPHERE DESTABILIZING AS WE MOVE ALONG THROUGH THE REST OF THE
AFTERNOON INTO THE EVENING. SB CAPES ARE FORECAST TO HIT
1000-1500+ JOULES MAINLY ACROSS THE NORTHERN AND WESTERN AREAS.
THERE IS SOME GOOD SPEED SHEAR ESPECIALLY FROM 700-500MBS OF 50+
KTS. PWATS RISING ABOVE 1.5 INCHES AND K INDEX ABOVE 35. MESOSCALE
GUIDANCE INCLUDING THE HRRR 3KM AND NAM12 POINT TO THE FIRST BATCH
ASSOCIATED W/A PRE-FRONTAL TROUGH TO MOVE ACROSS THE AREA THIS
AFTERNOON W/THE HEAVIEST ACTION ACROSS THE FAR NORTH ATTM. THE
SECOND ROUND W/THE APPROACHING COLD FRONT EXPECTED LATER THIS
AFTERNOON INTO THE EVENING W/BROKEN LINE SEGMENTS OF CONVECTION.
THIS IS WHEN THE BEST MID LEVEL FORCING ARRIVES AS WELL TO ENHANCE
THE STORMS. KEPT THE ENHANCED WORDING IN THERE FOR THE NORTHERN
1/2 OF THE CWA W/SOME STORMS PRODUCING DAMAGING WIND GUSTS AND
HAVING ROTATION. FLOW PARALLELING THE LINE SEGMENTS COULD ALLOW
FOR SOME TRAINING OF THE CELLS W/HEAVY RAINFALL AND POSSIBLE FLASH
FLOODING. ALTHOUGH ATTM, CONFIDENCE ON THE FLASH FLOODING IS LOW
DUE TO FAST FLOW ALOFT. FURTHER S AND E TOWARDS CENTRAL AND
DOWNEAST AREAS, LLVLS A BIT MORE STABLE TO ALLEVIATE ANY STRONG
CONVECTION. THEREFORE, KEPT JUST GENERAL WORDING FOR TSTMS FOR
NOW. THE COAST LOOKS TO BE CONVECTION FREE FROM THIS STANDPOINT.
AS THE NIGHT WEARS ON, CONVECTION WILL WIND DOWN W/PRECIP JUST IN
THE FROM OF SHOWERS AND A STEADY RAIN AS WEAK LOW PRES WAVE IS
FORECAST TO DEVELOP ON THE FRONT. THIS WILL SLOW THE FORWARD
PROGRESS OF THE FRONT UP FOR A TIME OVERNIGHT.
ON SUNDAY, NORTHERN AREAS WILL BEGIN TO DRY AND COOL DOWN BEHIND
THE FRONT AND WINDS WILL TURN TO A MORE NNW DIRECTION. AIRMASS
BEHIND THE FRONT IS MUCH COLDER AND TEMPS FOR SUNDAY WILL BE WELL
BELOW NORMAL FOR THE LAST DAY OF MAY. FURTHER S TOWARD THE BANGOR
AND BAR HARBOR REGIONS, RAIN/SHOWERS WILL HANG ON AS THE FRONT
STALLS FOR A TIME ACROSS THE DOWNEAST REGION. DAYTIME TEMPERATURES
ARE FORECAST TO BE IN THE UPPER 50S TO LOWER 60S. TOTAL RAINFALL
FROM THIS EVENT IS EXPECTED TO BE IN THE RANGE OF 0.40 TO 0.75
INCHES W/THE HIGHEST AMOUNTS EXPECTED ACROSS THE NORTHERN 1/2 OF
THE CWA.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
A STALLED STATIONARY BOUNDARY ACROSS SOUTHERN MAINE WILL INTERACT
WITH AN OVERRUNNING SURGE OF SUB-TROPICAL MOISTURE TO BRING STEADY
RAIN THIS PERIOD ACROSS DOWNEAST MAINE. FORECAST CONFIDENCE ON THE
EXACT AXIS OF HEAVY RAIN AND HOW FAR NORTH IT SPREADS STILL REMAINS
LOW. CONFIDENCE IS HIGHEST THAT THERE WILL BE AN AXIS OF 1-2" OF
RAIN ACROSS SOUTHERN PENOBSCOT...HANCOCK...AND WASHINGTON COUNTY
OVER THIS 48 HOUR PERIOD. RAINFALL AMOUNTS WILL FALL OFF
DRASTICALLY AS YOU HEAD INTO NORTHERN MAINE. DUE TO LARGE SPREAD IN
THE QPF BETWEEN THE SREF...NAM...ECMWF...AND GFS DECIDED TO GO WITH
A BLEND OF ALL GUIDANCE. TEMPERATURES WILL BE COOL FOR THIS PERIOD
WITH HIGHS MOSTLY IN THE MID TO LOWER 50S ACROSS CENTRAL AND
DOWNEAST MAINE AS COOL EASTERLY ONSHORE FLOW...AND OVERCAST SKIES
CAP ANY WARMING. FURTHER NORTH HIGH TEMPERATURES WILL BE WARMER IN
THE LOW 60S ON MONDAY WITH SOME BREAKS OF SUN POSSIBLE...WIDESPREAD
CLOUD COVER WILL KEEP THINGS COOLER ON TUESDAY. WINDS WILL REMAIN
LIGHT OUT OF THE EAST THROUGH THE ENTIRE PERIOD.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
CLOSED UPPER LOW OVER CWA WILL FINALLY MOVE EAST EARLY WEDNESDAY
WITH DECREASING CLOUDS AND SHOWERS THROUGH THE EARLY MORNING
HOURS. HIGH PRESSURE BUILDS IN BY LATE WEDNESDAY AND DOMINATES
THROUGH FRIDAY. HIGHS WILL REBOUND INTO THE LOW TO MID 70S AND
WITH INCREASING HUMIDITY LOWS WILL CLIMB BACK TO THE MID 50S BY
FRIDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST ON FRIDAY WILL
BRING INCREASING CLOUDINESS AND SHOWERS AND COOLER TEMPERATURES
FOR THE WEEKEND.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
NEAR TERM: VFR ACROSS THE NORTHERN GOING TO MVFR THIS EVENING
W/SOME TSTMS. CONDITIONS WILL THEN GO TO IFR IN RAIN OVERNIGHT
INTO EARLY SUNDAY MORNING AND THEN VFR BY MIDDAY. FOR KBGR AND
BHB, VFR GOING TO MVFR/IFR LATER TONIGHT INTO EARLY SUNDAY.
CONDITIONS WILL BEGIN TO IMPROVE TO VFR ESPECIALLY FOR BGR BY
EARLY AFTERNOON.
SHORT TERM: MONDAY THROUGH TUESDAY...SIGNIFICANT
RAINFALL IS EXPECTED SOUTH OF KHUL THROUGH THIS PERIOD WITH IFR
CONDITIONS BEING THE NORM AT KBNG/KBHB WITH LOW CIGS/VIS IN STEADY
RAIN. FURTHER NORTH CONDITIONS WILL NOT BE AS BAD...ESPECIALLY ON
MONDAY WITH VFR CONDITIONS EXPECTED. TUESDAY FORECAST CONFIDENCE
IS STILL LOW ON HOW FAR NORTH THE HEAVIER RAIN WILL SPREAD...WITH
KHUL HAVING THE HIGHEST PROBABILITY OF BEGIN IMPACTED BY IFR
CONDITIONS.
&&
.MARINE...
NEAR TERM: SCA REMAINS IN PLACE ATTM. THE WIND AND SEAS HAVE
FINALLY COME UP AND THE SEAS ARE RUNNING NEAR 5 FT AT THE EASTERN
MAINE SHELF. THE WIND WILL START TO COME DOWN AS THE GRADIENT
WEAKENS AND THEN FRONT STALLS ACROSS THE WATERS BY SUNDAY MORNING.
THE SCA MADE NEED TO BE TRANSITIONED TO HAZARDOUS SEAS ON SUNDAY
W/A SWELL COMPONENT EXPECTED TO SET UP.
SHORT TERM: NO ADVISORIES EXPECTED...BUT SEAS COULD BE CLOSE TO
THE 5 FOOT MONDAY AND TUESDAY. SIGNIFICANT RAINFALL IS ALSO
EXPECTED MONDAY NIGHT THROUGH TUESDAY WHICH WILL KEEP VISIBILITIES
AROUND 2 MILES...LOCALLY LOWER IN HEAVIER RAIN. WINDS WILL REMAIN
OUT OF THE NORTHEAST FOR THIS ENTIRE PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ050>052.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...DUMONT
LONG TERM...RAHE
AVIATION...CB/HEWITT/DUMONT
MARINE...CB/HEWITT/DUMONT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
407 PM EDT SAT MAY 30 2015
.SYNOPSIS...
A COLD FRONT WILL ENTER THE REGION THIS EVENING AND SLOWLY MOVE
ACROSS THE FORECAST AREA TONIGHT AND SUNDAY. THE FRONT WILL RETURN
NORTHWARD AS A WARM FRONT MONDAY AND LOW PRESSURE WILL CROSS THE
STATE TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ATMOSPHERE DESTABILIZING AS WE MOVE ALONG THROUGH THE REST OF THE
AFTERNOON INTO THE EVENING. SB CAPES ARE FORECAST TO HIT
1000-1500+ JOULES MAINLY ACROSS THE NORTHERN AND WESTERN AREAS.
THERE IS SOME GOOD SPEED SHEAR ESPECIALLY FROM 700-500MBS OF 50+
KTS. PWATS RISING ABOVE 1.5 INCHES AND K INDEX ABOVE 35. MESOSCALE
GUIDANCE INCLUDING THE HRRR 3KM AND NAM12 POINT TO THE FIRST BATCH
ASSOCIATED W/A PRE-FRONTAL TROUGH TO MOVE ACROSS THE AREA THIS
AFTERNOON W/THE HEAVIEST ACTION ACROSS THE FAR NORTH ATTM. THE
SECOND ROUND W/THE APPROACHING COLD FRONT EXPECTED LATER THIS
AFTERNOON INTO THE EVENING W/BROKEN LINE SEGMENTS OF CONVECTION.
THIS IS WHEN THE BEST MID LEVEL FORCING ARRIVES AS WELL TO ENHANCE
THE STORMS. KEPT THE ENHANCED WORDING IN THERE FOR THE NORTHERN
1/2 OF THE CWA W/SOME STORMS PRODUCING DAMAGING WIND GUSTS AND
HAVING ROTATION. FLOW PARALLELING THE LINE SEGMENTS COULD ALLOW
FOR SOME TRAINING OF THE CELLS W/HEAVY RAINFALL AND POSSIBLE FLASH
FLOODING. ALTHOUGH ATTM, CONFIDENCE ON THE FLASH FLOODING IS LOW
DUE TO FAST FLOW ALOFT. FURTHER S AND E TOWARDS CENTRAL AND
DOWNEAST AREAS, LLVLS A BIT MORE STABLE TO ALLEVIATE ANY STRONG
CONVECTION. THEREFORE, KEPT JUST GENERAL WORDING FOR TSTMS FOR
NOW. THE COAST LOOKS TO BE CONVECTION FREE FROM THIS STANDPOINT.
AS THE NIGHT WEARS ON, CONVECTION WILL WIND DOWN W/PRECIP JUST IN
THE FROM OF SHOWERS AND A STEADY RAIN AS WEAK LOW PRES WAVE IS
FORECAST TO DEVELOP ON THE FRONT. THIS WILL SLOW THE FORWARD
PROGRESS OF THE FRONT UP FOR A TIME OVERNIGHT.
ON SUNDAY, NORTHERN AREAS WILL BEGIN TO DRY AND COOL DOWN BEHIND
THE FRONT AND WINDS WILL TURN TO A MORE NNW DIRECTION. AIRMASS
BEHIND THE FRONT IS MUCH COLDER AND TEMPS FOR SUNDAY WILL BE WELL
BELOW NORMAL FOR THE LAST DAY OF MAY. FURTHER S TOWARD THE BANGOR
AND BAR HARBOR REGIONS, RAIN/SHOWERS WILL HANG ON AS THE FRONT
STALLS FOR A TIME ACROSS THE DOWNEAST REGION. DAYTIME TEMPERATURES
ARE FORECAST TO BE IN THE UPPER 50S TO LOWER 60S. TOTAL RAINFALL
FROM THIS EVENT IS EXPECTED TO BE IN THE RANGE OF 0.40 TO 0.75
INCHES W/THE HIGHEST AMOUNTS EXPECTED ACROSS THE NORTHERN 1/2 OF
THE CWA.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
A STALLED STATIONARY BOUNDARY ACROSS SOUTHERN MAINE WILL INTERACT
WITH AN OVERRUNNING SURGE OF SUB-TROPICAL MOISTURE TO BRING STEADY
RAIN THIS PERIOD ACROSS DOWNEAST MAINE. FORECAST CONFIDENCE ON THE
EXACT AXIS OF HEAVY RAIN AND HOW FAR NORTH IT SPREADS STILL REMAINS
LOW. CONFIDENCE IS HIGHEST THAT THERE WILL BE AN AXIS OF 1-2" OF
RAIN ACROSS SOUTHERN PENOBSCOT...HANCOCK...AND WASHINGTON COUNTY
OVER THIS 48 HOUR PERIOD. RAINFALL AMOUNTS WILL FALL OFF
DRASTICALLY AS YOU HEAD INTO NORTHERN MAINE. DUE TO LARGE SPREAD IN
THE QPF BETWEEN THE SREF...NAM...ECMWF...AND GFS DECIDED TO GO WITH
A BLEND OF ALL GUIDANCE. TEMPERATURES WILL BE COOL FOR THIS PERIOD
WITH HIGHS MOSTLY IN THE MID TO LOWER 50S ACROSS CENTRAL AND
DOWNEAST MAINE AS COOL EASTERLY ONSHORE FLOW...AND OVERCAST SKIES
CAP ANY WARMING. FURTHER NORTH HIGH TEMPERATURES WILL BE WARMER IN
THE LOW 60S ON MONDAY WITH SOME BREAKS OF SUN POSSIBLE...WIDESPREAD
CLOUD COVER WILL KEEP THINGS COOLER ON TUESDAY. WINDS WILL REMAIN
LIGHT OUT OF THE EAST THROUGH THE ENTIRE PERIOD.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
CLOSED UPPER LOW OVER CWA WILL FINALLY MOVE EAST EARLY WEDNESDAY
WITH DECREASING CLOUDS AND SHOWERS THROUGH THE EARLY MORNING
HOURS. HIGH PRESSURE BUILDS IN BY LATE WEDNESDAY AND DOMINATES
THROUGH FRIDAY. HIGHS WILL REBOUND INTO THE LOW TO MID 70S AND
WITH INCREASING HUMIDITY LOWS WILL CLIMB BACK TO THE MID 50S BY
FRIDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST ON FRIDAY WILL
BRING INCREASING CLOUDINESS AND SHOWERS AND COOLER TEMPERATURES
FOR THE WEEKEND.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
NEAR TERM: VFR ACROSS THE NORTHERN GOING TO MVFR THIS EVENING
W/SOME TSTMS. CONDITIONS WILL THEN GO TO IFR IN RAIN OVERNIGHT
INTO EARLY SUNDAY MORNING AND THEN VFR BY MIDDAY. FOR KBGR AND
BHB, VFR GOING TO MVFR/IFR LATER TONIGHT INTO EARLY SUNDAY.
CONDITIONS WILL BEGIN TO IMPROVE TO VFR ESPECIALLY FOR BGR BY
EARLY AFTERNOON.
SHORT TERM: MONDAY THROUGH TUESDAY...SIGNIFICANT
RAINFALL IS EXPECTED SOUTH OF KHUL THROUGH THIS PERIOD WITH IFR
CONDITIONS BEING THE NORM AT KBNG/KBHB WITH LOW CIGS/VIS IN STEADY
RAIN. FURTHER NORTH CONDITIONS WILL NOT BE AS BAD...ESPECIALLY ON
MONDAY WITH VFR CONDITIONS EXPECTED. TUESDAY FORECAST CONFIDENCE
IS STILL LOW ON HOW FAR NORTH THE HEAVIER RAIN WILL SPREAD...WITH
KHUL HAVING THE HIGHEST PROBABILITY OF BEGIN IMPACTED BY IFR
CONDITIONS.
&&
.MARINE...
NEAR TERM: SCA REMAINS IN PLACE ATTM. WINDS HAVE BEEN SLOW TO COME
UP HOLDING AT 10 KTS W/SEAS AROUND 2 FT. CONDITIONS ARE EXPECTED
TO PICK UP LATER THIS EVENING W/WINDS HITTING 15-20 KTS AND GUSTS
AT 25 KT ESPECIALLY FOR THE OUTER ZONES. WAVE HEIGHTS WILL BUILD
TO 4 TO 6 FT BY MIDNIGHT. WINDS WILL START TO COME DOWN AS THE
GRADIENT WEAKENS AND THEN FRONT STALLS ACROSS THE WATERS BY SUNDAY
MORNING. THE SCA MADE NEED TO BE TRANSITIONED TO HAZARDOUS SEAS
ON SUNDAY W/A SWELL COMPONENT EXPECTED TO SET UP.
SHORT TERM: NO ADVISORIES EXPECTED...BUT SEAS COULD BE CLOSE TO
THE 5 FOOT MONDAY AND TUESDAY. SIGNIFICANT RAINFALL IS ALSO
EXPECTED MONDAY NIGHT THROUGH TUESDAY WHICH WILL KEEP VISIBILITIES
AROUND 2 MILES...LOCALLY LOWER IN HEAVIER RAIN. WINDS WILL REMAIN
OUT OF THE NORTHEAST FOR THIS ENTIRE PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUMONT
LONG TERM...RAHE
AVIATION...HEWITT/DUMONT
MARINE...HEWITT/DUMONT
AREA FORECAST DISCUSSION
NWS GAYLORD MI
349 PM EDT SAT MAY 30 2015
.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 345 PM EDT SAT MAY 30 2015
HIGH IMPACT WEATHER POTENTIAL: NOT MUCH. PATCHY FROST
POTENTIAL FOR EASTERN UPPER MICHIGAN.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: MUCH COOLER AIRMASS NOW
FULLY IN PLACE ACROSS NORTHERN MICHIGAN...COURTESY OF GUSTY NORTH
WINDS BEHIND MUCH EARLIER PASSING COLD FRONT. LAGGING BEHIND OFF
THE DECK FRONTAL FEATURES...COMBINED WITH EXCELLENT RER UPPER JET
DYNAMICS...CONTINUES TO PRODUCE WIDESPREAD LIGHT TO MODERATE RAINS
ALONG AND SOUTH OF THE M-72 CORRIDOR. TRENDS HAVE DEFINITELY BEEN
SOUTHWARD WITH THIS RAIN AXIS...WITH AGGRESSIVE DRYING NOTED PER
LATEST RAP ANALYSIS SPREADING STEADILY SOUTH ACROSS EASTERN UPPER
MICHIGAN AND THE TIP OF THE MITT. THIS SOUTHWARD PROGRESSION WILL
CONTINUE...WITH ALL DEEP LAYER FORCING CENTERING ITSELF ACROSS
SOUTHERN MICHIGAN TONIGHT INTO SUNDAY IN RESPONSE TO SHORTWAVE
TROUGH MERGER AND DEVELOPING OHIO VALLEY LOW PRESSURE.
PRIMARY FORECAST CONCERNS/CHALLENGES: EVENING RAIN AND OVERNIGHT
TEMPERATURE TRENDS.
DETAILS: AS MENTIONED...STEADY SOUTHWARD PUSH TO CURRENT RAIN AXIS
WILL CONTINUE THIS AFTERNOON AND EVENING. RATHER IMPRESSIVE (FOR THE
SEASON) SHORTWAVE TROUGH MERGER AND ATTENDANT SURFACE CYCLOGENESIS
TAKES PLACE ACROSS THE NORTHERN OHIO VALLEY TONIGHT AND SUNDAY...
FORCING THIS RAIN SHIELD TO STALL AND INTENSIFY OVER SOUTHERN
MICHIGAN. NEARLY ALL TRENDS SUPPORT THIS OCCURRING JUST SOUTH OF OUR
SOUTHERN BORDER. WILL DEFINITELY NEED TO MONITOR...BUT HAVE
CAUTIOUSLY TAKING THIS MORE OPTIMISTIC APPROACH...ENDING ALL RAINS
OVERNIGHT. DEEP SOUTHWEST FLOW WILL BE MAINTAINED ALOFT...SUGGESTING
PLENTY OF HIGH CLOUDS WILL CONTINUE TO STREAM OVER NORTHERN LOWER
MICHIGAN RIGHT THROUGH THE OVERNIGHT. COMBINE THIS WITH STILL DECENT
PRESSURE GRADIENT ALLOWING LIGHT WINDS TO CONTINUE...AND JUST GOTTA
SIDE WITH THE WARMER END OF THE GUIDANCE SPECTRUM (ESSENTIALLY
IGNORING ALL STRAIGHT MOS GUIDANCE) FOR LOWS TONIGHT. THAT GIVES MID
30S/LOWER 40S FOR LOWS SOUTH OF THE BRIDGE...NEGATING ANY MENTION OF
FROST DEVELOPMENT. READINGS SHOULD BE A TOUCH CHILLER ACROSS EASTERN
UPPER...MORE SOLIDLY IN THE MIDDLE 30S. EVEN HERE...MAINTENANCE OF
LIGHT WINDS SHOULD PREVENT WIDESPREAD FROST FORMATION AND A NEED FOR
A HEADLINE.
&&
.SHORT TERM...(SUNDAY THROUGH TUESDAY)
ISSUED AT 345 PM EDT SAT MAY 30 2015
...DRYING OUT TO START THE WEEK/COOL SUNDAY FOLLOWED BY MODERATING
TEMPERATURES...
HIGH IMPACT WEATHER POTENTIAL: FROST POTENTIAL EARLY MONDAY
MORNING...POSSIBLY EARLY TUESDAY MORNING AS WELL.
PATTERN SYNOPSIS/FORECAST: SPLIT FLOW PATTERN FROM THE EASTERN
PACIFIC ACROSS NORTH AMERICA WITH BULK OF THE NORTHERN BRANCH FLOW
ACROSS CANADA...WITH A SHORT WAVE TROUGH IN THE NORTHERN BRANCH OVER
NORTHWEST ONTARIO AND JUST CLIPPING THE UPPER GREAT LAKES. SHORT
WAVE TROUGHS IN THE SOUTHERN BRANCH RESIDE OVER WESTERN IOWA AND
ALONG THE LOWER MISSISSIPPI RIVER. CURRENT SURFACE ANALYSIS SHOWS A
COLD FRONT ACROSS LOWER MICHIGAN EXTENDING SOUTHWEST INTO THE MID
MISSISSIPPI VALLEY AND INTO OKLAHOMA/TEXAS. UNSEASONABLY STRONG
(FOR LATE MAY) 1033MB SURFACE HIGH OVER SOUTHERN MANITOBA WITH A
RIDGE AXIS EXTENDING SOUTHWARD ACROSS THE PLAINS STATES TO THE TEXAS
PANHANDLE. PLENTY OF DEEP LAYER MOISTURE ALONG/AHEAD OF THE FRONT
WITH PRECIPITABLE WATER VALUES APPROACHING 1.50 INCHES...WITH
COOLER/DRIER AIR BEHIND THE BOUNDARY (850MB 0C ISOTHERM CREEPING
ACROSS LAKE SUPERIOR).
SOUTHERN BRANCH ENERGY WILL SLIDE MOSTLY SOUTH OF MICHIGAN SUNDAY...
WHILE NEW SHORT WAVE TROUGHING TAKES SHAPE OVER THE UPPER LAKES
SUNDAY NIGHT INTO MONDAY...SHIFTING INTO NEW ENGLAND ON TUESDAY.
COLD FRONT WILL SETTLE ACROSS THE OHIO VALLEY TONIGHT...WITH A
FRONTAL WAVE SPINNING UP ALONG IT WITHIN JET ENTRANCE REGION
FORCING...KEEPING A DECENT NORTHEAST GRADIENT ACROSS LOWER MICHIGAN
SUNDAY. HIGH PRESSURE RIDGES INTO THE UPPER LAKES FROM THE
NORTHEAST ON MONDAY...WHILE SHORT WAVE TROUGHING GETS ORGANIZED
OVERHEAD. HIGH PRESSURE "BUBBLE" IN PLACE FOR TUESDAY AS SHORT WAVE
ENERGY STARTS TO PULL AWAY.
PRIMARY FORECAST CONCERNS: LOW TEMPERATURES/FROST POTENTIAL EARLY
MONDAY MORNING...PERHAPS AGAIN IN SPOTS EARLY TUESDAY MORNING.
SUNDAY...PRECIPITATION WILL BE ONGOING ACROSS FAR SOUTHERN LOWER
MICHIGAN WITHIN DEFORMATION AXIS TO THE NORTH OF THE FRONTAL WAVE
CROSSING INDIANA/OHIO. THIS WILL BRING MID/HIGH CLOUDS TO NORTHERN
LOWER MICHIGAN...THICKER CLOSER TO SAGINAW BAY BUT THAT WILL BE
ABOUT IT EXPECTING MUCH OF THE PRECIPITATION WILL BE SOUTH OF THE
AREA (COULD BE CLOSE FOR GLADWIN/ARENAC COUNTIES SO THAT IS ONE AREA
WORTH WATCHING). WILL ALSO BE BREEZY THE FARTHER SOUTH ONE GOES...
WITH WIND GUSTS TO 35 MPH OVER THE FAR SOUTHEAST PORTION OF THE
FORECAST AREA DURING THE FIRST HALF OF THE DAY. COOL AFTERNOON
HIGHS MOSTLY IN THE 50S (AROUND 60 PARTS OF NORTHWEST LOWER).
SUNDAY NIGHT LOW TEMPERATURES WILL BE TRICKY...ESPECIALLY STARTING
THE NIGHT ON THE COOL SIDE. LOOKS LIKE WINDS WILL BE MORE LIKELY TO
DECOUPLE SUNDAY NIGHT...AND WITH DEW POINTS MIXING INTO THE UPPER
20S/LOWER 30S HAVE A GOOD BIT OF ROOM TO DROP. COMPLICATING FACTOR
IS MID/HIGH CLOUDS DEVELOPING WITH STRENGTHENING SHORT WAVE
TROUGHING...WHICH DEPENDING ON TIMING/COVERAGE WOULD STABILIZE
TEMPERATURES. FOR NOW WILL ALLOW TEMPERATURES TO DROP TOWARD THE
FREEZING MARK ACROSS PARTS OF EASTERN UPPER/NORTHERN LOWER WITH A
MENTION OF FROST BOTH IN THE FORECAST AND IN THE AFTERNOON HAZARDOUS
WEATHER OUTLOOK.
MONDAY...SOME MID/HIGH CLOUDS AROUND AS DEVELOPING UPPER LEVEL
VORTICITY CENTER TRACKS ACROSS LAKE SUPERIOR...OTHERWISE SHOULD BE
ANOTHER NICE AFTERNOON WITH TEMPERATURES MODERATING INTO THE 60S
(BUT STILL 4-8F OFF EARLY JUNE NORMALS). WINDS EXPECTED TO DECOUPLE
AGAIN MONDAY NIGHT WITH A WEAK GRADIENT IN PLACE...AND POTENTIAL FOR
TEMPERATURES TO DROP INTO THE 30S ONCE AGAIN IN SOME SPOTS.
TUESDAY...SURFACE HIGH PRESSURE AND SHORT WAVE RIDGING ALOFT
EXPECTED TO BRING ANOTHER DRY DAY WITH TEMPERATURES CONTINUING TO
RECOVER (MORE 70S EXPECTED FOR AFTERNOON HIGHS).
&&
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM EDT SAT MAY 30 2015
HIGH IMPACT WEATHER POTENTIAL: POSSIBLE THUNDERSTORMS FRIDAY AND
SATURDAY...
HIGH PRESSURE REMAINS THE MAIN PLAYER ACROSS THE REGION NEXT WEEK
THROUGH WEDNESDAY. THIS WILL MAKE FOR DRY CONDITIONS AND CONTINUED
MODERATING TEMPERATURES THOUGH THE MID WEEK PERIOD...WARMING TO
ABOVE NORMAL READINGS BY FRIDAY. HIGH PRESSURE NUDGES EAST ON
THURSDAY...AS AN UNORGANIZED SYSTEM OVER THE NORTHERN PLAINS
ENCROACHES ON THE GREAT LAKES. WILL BRING CHANCE POPS BACK IN FOR
THURSDAY...WITH HIGHER CONFIDENCE FOR MEASURABLE RAIN AND POSSIBLY
THUNDER ON FRIDAY AND SATURDAY AS THE LOW DEEPENS AND SLIDES EAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 106 PM EDT SAT MAY 30 2015
OVERHEAD RAINS WILL CONTINUE TO SAG SOUTH...EXITING ALL TAF SITES
THROUGH THIS AFTERNOON. LOW LEVEL MOISTURE WILL DO THE
SAME...LEAVING VFR CONDITIONS UNDER A BROKEN/SCATTERED CIRRUS DECK THROUGH
THE OVERNIGHT AND EARLY SUNDAY. NORTH TO NORTHEAST WINDS WILL
BECOME INCREASINGLY GUSTY SUNDAY MORNING.
&&
.MARINE...
ISSUED AT 345 PM EDT SAT MAY 30 2015
WINDS WILL CONTINUE TO VEER AROUND TO THE NORTHEAST
TONIGHT. WHILE WIND GUSTS WILL SLOWLY DECREASE ACROSS LAKE
MICHIGAN/SUPERIOR...INCREASING LONG FETCH LENGTH WILL RESULT IN VERY
GUSTY WINDS TARGETING THE AREA AROUND SAGINAW BAY LATER TONIGHT AND
SUNDAY. WILL HOIST SCA/S FOR THIS AREA...LETTING OTHERS EXPIRE AS
PLANNED. GUSTY NORTHEAST WINDS WILL CONTINUE ON SUNDAY...PERHAPS
REQUIRING A NORTHWARD EXTENSION OF THE LAKE HURON SCA.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 11 PM EDT THIS EVENING FOR MIZ020-
025-031.
LH...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 5 PM EDT SUNDAY
FOR LHZ349.
LM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SUNDAY FOR LMZ345-346.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ341.
LS...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LSZ321.
&&
$$
NEAR TERM...MSB
SHORT TERM...JPB
LONG TERM...BERGER/DE
AVIATION...MSB
MARINE...MSB
AREA FORECAST DISCUSSION
NWS BUFFALO NY
336 PM EDT SAT MAY 30 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE SLOWLY SOUTH ACROSS THE AREA TONIGHT THEN
STALL OVER PENNSYLVANIA THROUGH MONDAY BRINGING PERIODS OF RAIN.
SOME OF THE RAIN MAY BE HEAVY AT TIMES. A DRAMATICALLY COOLER
AIRMASS WILL MOVE INTO THE REGION SUNDAY AND MONDAY BEFORE A SLOW
WARMING TREND AND RETURN TO DRIER WEATHER BY THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
RADAR IMAGERY LATE THIS AFTERNOON SHOWING SCATTERED TO NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS FROM THE WESTERN SOUTHERN TIER
EASTWARD TO CENTRAL NY. EXPECT MOST OF THE RAIN TO STAY IN THIS
GENERAL AREA THROUGH EARLY TO MID EVENING...WITH A LARGE STABLE LAKE
SHADOW KEEPING THE NIAGARA FRONTIER TO ROCHESTER AND ALSO MUCH OF
JEFFERSON COUNTY DRY.
SPC OBJECTIVE RUC ANALYSIS SHOWING RELATIVELY MODEST SBCAPE OF
AROUND 1500J/KG WITH VERY LIMITED 25 KNOT 0-6KM DEEP LAYER SHEAR.
CONVECTION HAS DEVELOPED IN A LARGE NUMBER OF CLOSELY SPACED
CELLS...WHICH ARE COMPETING FOR THE RELATIVELY LIMITED INSTABILITY.
THIS WILL LIKELY PREVENT ANY ONE STORM FROM BECOMING VERY
STRONG...WITH ONLY SMALL HAIL AND HEAVY RAIN EXPECTED FROM THE
STRONGER CORES. BETTER DEEP LAYER SHEAR...INSTABILITY...AND LARGE
SCALE SUPPORT ACROSS SOUTHERN ONTARIO WILL REMAIN NORTH OF THE
BORDER UNTIL LATER THIS EVENING...AND BY THAT TIME NOCTURNAL COOLING
WILL HAVE STABILIZED THE COLUMN ENOUGH TO GREATLY LIMIT THE
POTENTIAL FOR ANY STRONGER STORMS.
LATER THIS EVENING THE SURFACE COLD FRONT OVER ONTARIO WILL BEGIN TO
SAG SLOWLY SOUTH ACROSS THE REGION...INCREASING LOW LEVEL
CONVERGENCE. A MORE ORGANIZED AREA OF CONVECTION OVER INDIANA AND
OHIO ASSOCIATED WITH A LOW AMPLITUDE MID LEVEL WAVE WILL MOVE
NORTHEASTWARD ALONG THE FRONTAL ZONE AND BRING INCREASING SHOWERS
AND SCATTERED THUNDERSTORMS. LATER TONIGHT MOST OF THE THUNDERSTORMS
WILL END AS THE COLD FRONT MOVES SOUTH AND A MUCH MORE STABLE LOW
LEVEL AIRMASS BUILDS INTO THE REGION. THE RAIN WILL CONTINUE HOWEVER
AS THE FRONT BECOMES ANABATIC IN NATURE...WITH ASCENT FOCUSING ON
THE COLD SIDE OF THE BOUNDARY.
LATE TONIGHT THROUGH SUNDAY THE FRONTAL ZONE WILL STALL FROM OHIO TO
PENNSYLVANIA. A STRONG DIFFERENTIAL TEMPERATURE ADVECTION REGIME
WILL DEVELOP ACROSS THE BOUNDARY...WITH LOW LEVEL COLD ADVECTION
TOPPED BY MID LEVEL WARM ADVECTION. THIS WILL PRODUCE STRONG
FRONTOGENSIS AND DEFORMATION ALONG AND NORTH OF THE BOUNDARY WHICH
WILL SUPPORT PERIODS OF RAIN ACROSS THE ENTIRE REGION. A FEW
SCATTERED THUNDERSTORMS ARE POSSIBLE NEAR THE PA STATE LINE...BUT
FOR THE REST OF THE AREA LITTLE INSTABILITY WILL REMAIN. RAIN TOTALS
TONIGHT THROUGH SUNDAY WILL APPROACH AN INCH...WITH LOCALLY HIGHER
AMOUNTS FROM CONVECTION THIS EVENING. ADDITIONAL RAIN WILL FALL
BEYOND SUNDAY.
TEMPERATURES WILL TURN DRAMATICALLY COOLER BEHIND THE FRONT LATE
TONIGHT AND SUNDAY. TEMPS IN THE MID 50S PRE-DAWN ON SUNDAY WILL
LIKELY DROP INTO THE UPPER 40S BY MID MORNING AS COLD ADVECTION AND
RAIN CONTINUE. TEMPS WILL THEN ONLY RECOVER TO THE LOWER 50S LATE IN
THE DAY AT BEST IN MOST AREAS. MILD TEMPERATURES AT MIDNIGHT WILL
PREVENT THE RECORD COLD HIGH TEMPS FROM BEING APPROACHED.
FINALLY...WITH THE DEEP LOW LEVEL MOISTURE AND NORTHERLY UPSLOPE
FLOW PATCHY FOG WILL DEVELOP LATER TONIGHT AND CONTINUE THROUGH
SUNDAY. EXPECT FOG TO BE MOST WIDESPREAD ACROSS THE HIGHER TERRAIN
WHERE LOW STRATUS WILL INTERSECT THE TERRAIN. FOG MAY ALSO BECOME
MORE WIDESPREAD ALONG THE SOUTH SHORE OF LAKE ONTARIO WITH A MOIST
AIRMASS CROSSING THE STILL COLD LAKE WATERS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
A COMPLEX STORM AND MOISTURE LADEN STORM SYSTEM WILL CONTINUE TO
EVOLVE THROUGH THIS TIME PERIOD. ON SUNDAY THE SURFACE BAROCLINIC
BOUNDARY WILL LIE FROM NEW ENGLAND SOUTHWESTWARD ACROSS THE
SOUTHERN MID ATLANTIC STATES AND BACK TOWARDS THE MID WEST. A
SURFACE WAVE RIDING SLOWLY ALONG THIS BAROCLINIC BOUNDARY FROM THE
OHIO VALLEY WILL SEND ANOTHER WAVE OF RAINFALL ACROSS THE REGION
ON SUNDAY. PWATS SUNDAY WILL AVERAGE 1.50 TO 1.75
INCHES...INDICATING THE MOISTURE RICH ENVIRONMENT. SHARP
ISENTROPIC LIFT IN THE MID LEVELS NORTHEAST OF THE SURFACE WAVE
AND THE STILL PRESENT RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET
WILL PROVIDE FOR BROAD LIFT ACROSS THE EASTERN GREAT LAKES
REGION...WITH THIS LIFT PRODUCING A PERIOD OF RAIN SHOWERS THROUGH
THE DAY. FAVORABLE CONDITIONS FOR RAIN SHOWERS SUNDAY WILL SLOWLY
PUSH EASTWARD THROUGH THE DAY AS THE UPPER LEVEL JET AND SURFACE
WAVE SLIDE EASTWARD. BY SUNDAY NIGHT THE AREAS MOST PRONE TO RAIN
SHOWERS WILL BE CENTRAL PORTIONS OF NEW YORK STATE. HOWEVER WITH
THE SURFACE WAVE STALLING OVER PENNSYLVANIA SUNDAY NIGHT...ALL
AREAS OF THE CWA WILL HAVE AT LEAST LIKELY POPS.
INSTABILITY WILL BE MARGINAL FOR THUNDERSTORMS SUNDAY AND SUNDAY
NIGHT...WITH WHAT INSTABILITY TO BE HAD THIS DAY LYING ACROSS THE
SOUTHERN TIER. WILL PLACE THUNDER CHANCES HERE...WHILE JUST CALLING
IT PLAIN RAIN SHOWERS ACROSS THE REMAINDER OF THE REGION.
WE HAVE NOT HAD A WIDESPREAD, LONG DURATION SYNOPTIC PRECIPITATION
EVENT OF THIS MAGNITUDE IN QUITE SOME TIME. RAINFALL AMOUNTS SUNDAY
AND SUNDAY NIGHT WILL AVERAGE AROUND A HALF AN INCH OF
PRECIPITATION...WITH A FEW AREAS UPWARDS TO THREE QUARTERS OF AN
INCH. ALL TOLD BY THE END OF THE WEEKEND AN INCH TO TWO INCHES OF
RAINFALL IS LIKELY ACROSS THE CWA. WITH THE VERY DRY CONDITIONS AND
LOW CREEK AND STREAM FLOWS RIVER FLOODING IS NOT A BIG CONCERN AT
THIS POINT...AND WOULD ONLY BECOME A CONCERN IN AREAS WHERE STORMS
TRAIN AND PRODUCE LOCALLY SIGNIFICANT AMOUNTS.
BY MONDAY THE MID LEVEL SHORTWAVE WILL BE EAST OF THE REGION.
HOWEVER AT THE SURFACE A WAVE OF LOW PRESSURE WILL STILL BE NEAR THE
REGION AND WILL ADVANCE FROM WESTERN PENNSYLVANIA TOWARDS THE
EASTERN MID ATLANTIC REGION. A NORTHWEST FLOW BEHIND THIS SURFACE
LOW AND EASTERLY FLOW AHEAD OF THE SURFACE LOW WILL PROVIDE FOR
AMPLE LOW LEVEL CONVERGENCE ACROSS THE REGION. A MOISTURE RICH
ENVIRONMENT WILL REMAIN AND LIGHT RAIN SHOWERS WILL AGAIN DEVELOP
ACROSS THE EASTERN GREAT LAKES REGION ON MONDAY. THE POOR LAPSE
RATES AND LITTLE SURFACE INSTABILITY ON MONDAY WILL NOT MAKE FOR A
FAVORABLE ENVIRONMENT FOR THUNDERSTORM DEVELOPMENT.
RAIN SHOWERS MAY NOT TAPER OFF AS QUICKLY MONDAY NIGHT. THOUGH THE
SURFACE LOW WILL BE TRACKING ACROSS NEW ENGLAND MONDAY NIGHT...AND
UPPER LEVEL SHORTWAVE TROUGH WILL ADVANCE TOWARDS OUR REGION FROM
THE CENTRAL GREAT LAKES. THIS FEATURE WILL CONTINUE CHANCE POPS
ACROSS THE REGION MONDAY NIGHT.
ON TUESDAY THIS UPPER LEVEL SHORTWAVE TROUGH WILL CROSS THE EASTERN
GREAT LAKES REGION. A COLD POOL ASSOCIATED WITH THIS TROUGH WILL
INCREASE LAPSE RATES THROUGH THE DAY SUCH THAT LOW TOP SHOWERS WILL
DEVELOP THROUGH THE DAYTIME. MOISTURE WILL BE FOUND GREATEST TOWARDS
THE EAST...FROM THE GENESEE VALLEY EASTWARD THERE WILL BE A CHANCE
FOR A BRIEF SHOWER. CLOUDS WILL LIKELY START THE DAY THICK ACROSS
THE EASTERN GREAT LAKES REGION...WITH CLEARING SLOWLY EDGING
EASTWARD THROUGH THE AFTERNOON HOURS. A MUCH DRIER AIRMASS BEHIND
THIS SHORTWAVE WILL CLEAR SKIES TUESDAY NIGHT...MAKING FOR A CHILLY
NIGHT UNDER GOOD RADIATIONAL COOLING CONDITIONS.
TEMPERATURES THIS TIME PERIOD WILL AVERAGE WELL BELOW NORMAL...WITH
HIGHS SUNDAY AND MONDAY IN THE 50S. A FEW LOW 60S ARE POSSIBLE NEAR
THE STATE LINE WHERE THE SURFACE BOUNDARY MAY EDGE NORTHWARD ENOUGH
TO ALLOW FOR WARMER AIR TO REACH INTO THE SOUTHERN TIER. TUESDAY
UNDER CLOUDY SKIES AND 850 HPA TEMPERATURES OF ONLY +4 TO +5C
DAYTIME HIGHS WILL STILL REMAIN IN THE 50S TO AROUND 60. LOWS
TUESDAY NIGHT WILL DROP BACK INTO THE 40S...5 TO 10F DEGREES BELOW
NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
RIDGING ALOFT AND SURFACE HIGH PRESSURE FINALLY BUILD IN ACROSS
WESTERN NEW YORK FOR THE SECOND HALF OF THE WORK WEEK. WITH A DRIER
AIRMASS MOVING IN ON WEDNESDAY...EXPECT MOST LOCATIONS TO FINALLY
CLEAR OUT NICELY AFTER A GLOOMY START TO THE WEEK. NICE WEATHER WILL
REMAIN WITH US WEDNESDAY AND THURSDAY AS HIGH PRESSURE CROSSES THE
REGION. FRIDAY WILL BE THE NEXT CHANCE FOR SOME RAIN
SHOWERS...ALBEIT SMALL WITH A FEW THUNDERSTORMS POSSIBLY BLOSSOMING
ON A LAKE BREEZE BOUNDARY FRIDAY AFTERNOON.
TEMPERATURES WILL ALSO RECOVER THROUGH THE SECOND HALF OF THE WEEK
AS SOUTHERLY FLOW DEVELOPS ON THE BACK SIDE OF THE HIGH PRESSURE AND
WARM AIR ADVECTION PUSHES 850 MB TEMPERATURES BACK INTO THE LOW
TEENS CELSIUS ABOVE ZERO. THE WARMING TREND WILL BRING 70S BACK TO
THE FORECAST ON WEDNESDAY WITH MID 80S POSSIBLE BY FRIDAY.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
SHOWERS AND STORMS ARE INCREASING THIS AFTERNOON FROM THE SOUTHERN
TIER INTO THE GENESEE VALLEY AND CENTRAL NY. EXPECT SCATTERED TO
NUMEROUS COVERAGE TO CONTINUE IN THIS AREA THROUGH THE EVENING. VFR
WILL PREVAIL MOST OF THE TIME...BUT THE HEAVIER STORMS WILL PRODUCE
BRIEF MVFR/IFR CONDITIONS LOCALLY. A SOUTHWEST WIND OFF LAKE ERIE
AND ONTARIO WILL SUPPORT STABLE LAKE SHADOWS NORTHEAST OF BOTH LAKES
WITH LITTLE OR NO CONVECTION THROUGH LATE AFTERNOON...INCLUDING MOST
OF THE TAF SITES.
TONIGHT THE STABLE LAKE SHADOWS WILL BREAK DOWN WITH THE LOSS OF
DAYTIME HEATING. A COLD FRONT WILL SAG SLOWLY SOUTH ACROSS THE AREA
AND PROVIDE THE FOCUS FOR INCREASING RAIN COVERAGE FOR THE ENTIRE
REGION. SCATTERED THUNDERSTORMS WILL CONTINUE THROUGH THE EVENING
BEFORE DIMINISHING OVERNIGHT AS A MORE STABLE AIRMASS MOVES INTO THE
REGION. DURING THE EVENING CIGS/VSBY WILL STAY MAINLY VFR OUTSIDE OF
THE HEAVIER SHOWERS AND STORMS WHICH WILL CONTINUE TO PRODUCE BRIEF
MVFR/IFR LOCALLY.
OVERNIGHT EXTENSIVE LOW LEVEL MOISTURE WILL MOVE INTO THE AREA
BEHIND THE SURFACE COLD FRONT AND BECOME TRAPPED BENEATH A STEEP
FRONTAL INVERSION. THIS WILL SET THE STAGE FOR A RARE LATE SPRING
EXTENDED PERIOD OF IFR CIGS ACROSS MUCH OF THE REGION FROM LATER
TONIGHT THROUGH SUNDAY AND BEYOND. CIGS WILL BE LOWEST ACROSS THE
HIGHER TERRAIN...BUT EVEN THE LAKE PLAINS WILL SEE PLENTY OF IFR.
PATCHY FOG WILL ALSO REDUCE VSBY AT TIMES...ESPECIALLY ACROSS HIGHER
TERRAIN AND ALONG THE SOUTH SHORE OF LAKE ONTARIO. PERIODS OF RAIN
WILL CONTINUE ALONG AND NORTH OF THE STALLED FRONTAL BOUNDARY LATE
TONIGHT THROUGH SUNDAY.
OUTLOOK...
SUNDAY NIGHT AND MONDAY...WIDESPREAD IFR WITH PERIODS OF RAIN.
TUESDAY THROUGH WEDNESDAY...MAINLY VFR.
&&
.MARINE...
SOUTHWEST WINDS AHEAD OF A COLD FRONT WILL BECOME NORTH TONIGHT AS
THE FRONT SAGS SLOWLY SOUTH OF THE LOWER GREAT LAKES. THIS WILL
BRING A PERIOD OF MODERATE NORTH TO NORTHEAST WINDS LATER TONIGHT
THROUGH SUNDAY NIGHT WITH SMALL CRAFT ADVISORY CONDITIONS ON BOTH
LAKES ERIE AND ONTARIO.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 8 AM EDT MONDAY FOR
LEZ040-041.
SMALL CRAFT ADVISORY FROM 2 AM SUNDAY TO 2 AM EDT
MONDAY FOR LOZ030.
SMALL CRAFT ADVISORY FROM 8 AM SUNDAY TO 8 AM EDT MONDAY
FOR LOZ042-043.
SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 5 AM EDT MONDAY
FOR LOZ044-045.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
SLZ022-024.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...CHURCH
LONG TERM...CHURCH
AVIATION...HITCHCOCK
MARINE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
124 PM EDT SAT MAY 30 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED WELL OFF THE MID ATLANTIC COAST WILL
CONTINUE TO RIDGE SOUTHWESTWARD ACROSS THE CAROLINAS THROUGH EARLY
NEXT WEEK. AN APPROACHING COLD FRONT ON MONDAY MAY STALL ACROSS
THE AREA TUESDAY...REMAINING NEARBY THROUGH FRIDAY. NEXT WEEK
THERE IS A RISK FOR SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...OVERALL SYNOPTIC PATTERN REMAINS BASICALLY
UNCHANGED FROM THE PAST SEVERAL DAYS. EXPANSIVE SURFACE HIGH
CENTERED SEVERAL HUNDRED MILES NE OF BERMUDA IS MAINTAINING A RIDGE
AXIS BACK INTO THE CAROLINAS. ALOFT...A RIDGE AXIS REMAINS OVERHEAD
WHILE JUST ONLY SLOWLY MOVING TO THE NE. THESE FEATURES TOGETHER
WILL CONTINUE THE WARM...BUT AT TIMES SHOWERY...WEATHER TODAY.
MOIST ADVECTION ON LONG E/SE FETCH IS FINALLY OVERCOMING THE
CONTINENTAL DRY AIR AND SHOWERS HAVE DEVELOPED ACROSS THE CAPE FEAR
REGION AND OVER GEORGETOWN COUNTY THIS MORNING. AS NOTED
YESTERDAY...AIR PARCELS ARE ACTUALLY ORIGINATING OVER SE CANADA
BEFORE TRAVERSING CLOCKWISE AROUND THE RIDGE AND ADVECTING BACK INTO
THE CAROLINAS. THIS IS IMPORTANT BECAUSE THE AIRMASS IS OF DRY
ORIGIN...AND THUS IT IS DIFFICULT TO CREATE WIDESPREAD CONVECTION.
HOWEVER...ENOUGH MOISTURE IS PRESENT TODAY THAT SHOWERS WILL LIKELY
BE MORE WIDESPREAD THAN PREVIOUS DAYS...BUT STILL ONLY ISOLATED TO
SCATTERED IN NATURE. THE CURRENT HRRR IS PERFORMING WELL AND IS
LEANED UPON FOR THE DAYLIGHT HOURS. SHOWERS AT THE COAST WILL BE
MOST FAVORED THIS MORNING...THEN TRENDING INLAND THROUGH THE DAY.
THIS IS DUE TO A SURGE OF DRIER AIR FORECAST BY LOWER PWATS ON
SOUNDINGS AND PLAN-VIEW GUIDANCE...AND NOTED ON WV SATELLITE...WHICH
IS PROGGED TO SHIFT WEST INTO THE AREA THIS AFTN. HAVE BUMPED POP TO
CHC...USING THE SCT WORDING HOWEVER...ALONG THE CAPE FEAR COAST THIS
MORNING...AND THEN ADDED ISOLATED TO THE REST OF THE CWA THROUGH
THIS AFTN. THE DRY PUSH SHOULD KEEP SHOWER COVERAGE TO SCATTERED AT
BEST HOWEVER...ENDING BEFORE DARK...AND NO LIGHTNING IS ANTICIPATED.
HAVE BEEN FORECASTING HIGHS TOO LOW THE PAST FEW DAYS...SO EVEN WITH
THE EASTERLY FLOW HAVE FORECAST HIGHS ABOVE THE AVAILABLE
GUIDANCE...AND AM EXPECTING 80-82 AT THE BEACHES...TO AS HIGH AS 90
FROM KINGSTREE TO BENNETTSVILLE AND LUMBERTON.
LOWS TONIGHT WILL DROP INTO THE LOW 60S...MID 60S AT THE BEACHES.
WILL NEED TO WATCH ONCE AGAIN FOR ISOLATED ADVECTION SHOWERS MOVING
ONSHORE...ESPECIALLY NEAR THE CAPE FEAR REGION...BUT FOR NOW HAVE
LEFT OUT MENTIONABLE POP FROM THE FORECAST.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...MID TO UPPER TROUGH DIGGING DOWN THROUGH
THE MISSISSIPPI VALLEY ON SUNDAY WILL MOVE EAST PUSHING A COLD
FRONT INTO THE CAROLINAS BY MONDAY. QUIET WEATHER WILL PREVAIL
AHEAD OF THIS FRONT ON SUNDAY INTO EARLY MONDAY AS HIGH PRESSURE
REMAINS DOMINANT AT THE SURFACE WITH PLENTY OF DRY AIR AND
SUBSIDENCE ALOFT. ASIDE FROM SOME DIURNAL CU AND POSSIBLE ISOLATED
SHOWER ON SUNDAY...EXPECT A VERY WARM AND MOSTLY SUNNY DAY. A
STEADY STREAM OF MOIST AIR OFF THE ATLANTIC AROUND ATLANTIC RIDGE
WILL KEEP DEWPOINT TEMPS WELL INTO THE 60S SUNDAY INTO MONDAY WITH
OVERNIGHT LOWS CLOSER TO 70 AND DAY TIME HIGHS MID HIGHS TO NEAR
90.
WINDS WILL VEER AROUND AS TROUGH DISPLACES THE HIGH FURTHER
EAST AND COLD FRONT APPROACHES FROM THE WEST. THIS WILL ALSO HELP
TO TIGHTEN THE GRADIENT A BIT THROUGH MONDAY WITH INCREASING
MOISTURE ADVECTION AS SOUTHEAST WINDS BECOME MORE
SOUTHERLY...TAPPING INTO INCREASING GULF MOISTURE. PCP WATER
VALUES DOWN CLOSER TO AN INCH SUN MORNING WILL BE 1.5 TO 1.75
INCHES BY MON AFTN INTO MON NIGHT AHEAD OF APPROACHING COLD FRONT.
THE GFS SEEMS TO BE THE MOST AGGRESSIVE WITH SHWRS/TSTMS AHEAD OF
FRONT ON MONDAY. EITHER WAY THERE WILL BE INCREASING CLOUDS ACROSS
THE AREA LATE SUNDAY THROUGH MONDAY. LOOKS LIKE BEST UPPER LEVEL
SUPPORT WILL BE WEST OF AREA ON MONDAY...AFFECTING MORE OF THE I95
CORRIDOR OR WEST. BY MONDAY AS NORTHERN STREAM TROUGH PROGRESSES
EAST...THE SOUTHERN PORTION MAY CUT OFF OVER THE GULF AS RIDGE
GETS NUDGED SOUTHEASTWARD. THIS WILL STRETCH OUT THE FRONT MORE
WEST TO EAST JUST NORTHWEST OR OVER FORECAST AREA BY TUES MORNING
AND WILL CAUSE IT TO MOVE SLOWER OR STALL. OVERALL IT LOOKS LIKE
PLENTY OF MOISTURE AND LIFT IN SOUTHERLY FLOW AHEAD OF FRONT WILL
PRODUCE MORE WIDESPREAD CONVECTION LATE MONDAY AS CAP BECOMES
ERODED...ESPECIALLY OVER WESTERN PORTION OF FORECAST AREA. ONCE
DIURNAL HEATING CUTS OFF MON EVENING SHOULD BE LEFT WITH LINGERING
SHOWERS AND CLOUDS OVER AREA THROUGH MON NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...MID TO UPPER TROUGH EXTENDING DOWN FROM
THE GREAT LAKES WILL CONTINUE TO PUSH A COLD FRONT SOUTH AND EAST
ON TUES BUT AS THE NORTHERN PORTION MOVES OFF TO THE EAST...IT MAY
CUT OFF TO THE SOUTH LEAVING FRONT STRETCHED ACROSS THE AREA FROM
W-SW TO E-NE THROUGH MID WEEK. HIGH PRESSURE WILL TRY AND BUILD
DOWN BEHIND IT FROM THE UPPER GREAT LAKES BUT DEVELOPING LOW
PRESSURE NEAR THE YUCATAN PENINSULA ON WED WILL BEGIN TO TRACK
NORTHWARD. THE LATEST GFS RUN WAS MORE AGGRESSIVE IN TERMS OF
STRENGTH AND MOVEMENT NORTHWARD...BUT EITHER WAY CLOUDS AND
SHOWERS WILL MOST LIKELY REMAIN IN FORECAST THROUGH AT LEAST
FRIDAY. DRIER HIGH PRESSURE MAY WIN OUT OVER THE AREA ON
FRIDAY...BUT GFS WOULD HAVE LOW OVER GA/SC BORDER WITH PLENTY OF
MOISTURE AND GUSTY WINDS HEADING INTO NEXT WEEKEND. FOR NOW WILL
KEEP CHC OF PCP EACH DAY WITH GREATEST CHC TUES/WED AS FRONT SAGS
OVER AREA.
CLOUDS...PCP AND SLIGHTLY COOLER NORTHERLY FLOW WILL KEEP TEMPS A
COUPLE OF DEGREES OR SO BELOW CLIMO DURING THE DAY THROUGH MOST
OF THE PERIOD....WHILE KEEPING NIGHTTIME TEMPS ON THE WARMER SIDE.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...SCT TO OCCASIONALLY BKN VFR LEVEL LOW/MID CLOUDS
THIS AFTERNOON...MAINLY INLAND TERMINALS WITH E-SE WINDS. THERE WILL
BE ISOLATED SHOWERS...ESPECIALLY NEAR KILM...ENDING THIS AFTERNOON
BUT BECOMING POSSIBLE AGAIN LATER THIS EVENING. THIS EVENING WINDS
WILL BECOME LIGHT AND VARIABLE. MODELS AGAIN ARE SUGGESTING MVFR
VSBYS DUE TO BR AT THE INLAND TERMINALS. CONFIDENCE OF OCCURRENCE IS
INCREASING...AND HAVE ADDED MVFR PREDOMINANT AT CRE/FLO/LBT. SOME
SHOWERS MAY PRODUCE BRIEF MVFR CIGS AT ILM OVERNIGHT...BUT HAVE
OPTED TO LEAVE THAT OUT OF THE TAF FOR NOW...AND SINCE SHOWER
ACTIVITY SHOULD BE ISOLATED.
EXPECT THE SAME CONDITIONS AFTER SUNRISE WITH TEMPO MVFR CIGS
POSSIBLE BUT VFR FOR THE MOST PART. VCSH CONTINUES AT THE COASTAL
TERMINALS WITH WINDS BECOMING SE AT ALL TERMINALS LATE IN THE TAF
VALID PERIOD.
EXTENDED OUTLOOK...MORNING MVFR CONDITIONS WITH MAINLY AFTERNOON
ISOLATED/SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD. AN
INCREASED CHANCE FOR CONVECTION TUE AND WED. SHOWERS DECREASING FROM
WEST TO EAST THUR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...MORE OF THE SAME FOR THE MARINE COMMUNITY AS
EXPANSIVE AREA OF HIGH PRESSURE LOCATED WELL NE OF BERMUDA CONTINUES
ITS INFLUENCE LOCALLY. THE GRADIENT REMAINS PRETTY WEAK...SO E/SE
WINDS WILL CONTINUE...INCREASING FROM 5-10 KTS THIS MORNING TO 10-15
KTS THROUGH THE AFTN AND EARLY TONIGHT. A RETURN TO 5-10 KTS IS
FORECAST LATE. THE WAVE SPECTRUM WILL BE NEARLY ENTIRELY SWELL
DOMINATED...AS A 4 FT AT 9 SEC EASTERLY SWELL PERSISTS...PUSHING
WAVE HEIGHTS TO 2-4 FT THROUGH THE PERIOD.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...SE WIND EARLY SUNDAY WILL BECOME MORE
SOUTHERLY LATE SUN AND SUN NIGHT AS HIGH PRESSURE EXTENDING IN
FROM THE ATLANTIC BEGINS TO RETREAT. THE PERSISTENT SOUTHERLY PUSH
WILL KEEP SEAS 2 TO 4 FT THROUGH EARLY NEXT WEEK. A COLD FRONT
WILL APPROACH THE WATERS HEADING INTO TUES WHICH WILL HELP TO VEER
WINDS AROUND TO THE S-SW AND INCREASE SLIGHTLY FROM LESS THAN 10
KTS SUN INTO MON UP TO AROUND 10 KTS OR SO BY TUES MORNING. THE
LONGER PERIOD EASTERLY FETCH WITH A PERIOD UP TO 9 SECONDS WILL
COMBINE A SHORTER PERIOD WIND WAVE.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...WINDS WILL CONTINUE TO VEER AROUND TUES
INTO WED AS COLD FRONT LAYS DOWN ACROSS THE WATERS AND STALLS
THROUGH MID WEEK. THIS WILL SHIFT THE WINDS TO EASTERLY AND
EVENTUALLY NORTHEAST. WINDS MAY BECOME VARIABLE DEPENDING WHERE
FRONT STALLS WITH N-NE WINDS ON NORTH SIDE OF FRONT AND S-SE
WINDS ON SOUTH SIDE. WINDS WILL REMAIN 10 KTS OR LESS THROUGH MOST
OF THE PERIOD WITH SEAS 3 FT OR LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...JDW
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR/JDW
MARINE...JDW/RGZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
137 PM EDT SAT MAY 30 2015
.SYNOPSIS...
MOISTURE ASSOCIATED WITH LOW PRESSURE AND A SLOW MOVING COLD FRONT
WILL BRING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS TODAY
THROUGH SUNDAY. HIGH PRESSURE WILL BRING COOLER AND DRIER AIR FOR
THE BEGINNING OF THE WORK WEEK. WARMER TEMPERATURES WILL RETURN
LATER NEXT WEEK AS THE HIGH TRAVELS SLOWLY EASTWARD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST KILN SOUNDING SHOWING A PRETTY MOIST ENVIRONMENT OUT THERE
WITH PWATS AT 1.50" (NORMAL JUST ABOVE 1" FOR THIS TIME OF YEAR).
K INDEX WAS ALSO 35. HIGH RES MODELS ARE A BIT OVERDONE THIS
MORNING. LATEST HRRR DIDN`T INITIALIZE WELL WITH LATEST RAP
OVERDONE. THE NCEP WRF AND NSSL WRF SEEM TO BE DOING A GOOD JOB SO
FAR WITH MORNING RAIN AND SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS FORMING THIS AFTERNOON. HAVE PUSHED HIGHER POPS MORE
TOWARDS THIS AFTERNOON AND INCREASED POPS TO AT LEAST CHANCE
ACROSS THE AREA BY LATER AFTERNOON. THIS IS SUPPORTED BY 12Z KILN
SOUNDING DATA ALONG WITH HIGH RES MODELS. A FEW THUNDERSTORMS
COULD BE STRONG THIS AFTERNOON BUT LOWER INSTABILITY AND WIND SHEAR
SHOULD KEEP THE SEVERE POTENTIAL LIMITED. HIGHS IN THE LOWER TO
MID 80S STILL LOOK ON TRACK WITH 850 TEMPS VERY SIMILAR TO
YESTERDAY.
PREV DISCUSSION->
AREA IS IN A PERSISTENTLY HUMID SOUTHERLY FLOW BETWEEN HIGH
PRESSURE CENTERED TO THE EAST AND A LOW PRESSURE SYSTEM TO THE
WEST. ISOLATED SHOWERS HAVE DISSIPATED EARLY THIS MORNING LEAVING
PARTLY TO MOSTLY CLOUDY SKIES. LATEST RAP SHOWS PRECIP DEVELOPING
WITHIN THE NEXT COUPLE OF HOURS BUT THIS APPEARS OVERDONE. WILL
CONTINUE TO MONITOR.
A SURFACE LOW FORMING OVER MISSOURI AT THE TAIL END OF A COLD
FRONT WILL MOVE TO ILLINOIS THIS AFTERNOON. EXPECT SHOWERS AND
THUNDERSTORMS TO REDEVELOP TODAY AS INSTABILITY AND FORCING
INCREASES AHEAD OF THE LOW...ESPECIALLY THIS AFTERNOON DURING PEAK
HEATING. BEST CHANCE FOR CONVECTIVE DEVELOPMENT WILL BE IN
NORTHWEST COUNTIES CLOSER TO THE AXIS OF AN UPPER TROUGH CENTERED
OVER THE MISSISSIPPI VALLEY. A FEW STRONG THUNDERSTORMS WILL BE
POSSIBLE THIS AFTERNOON BUT RATHER WEAK INSTABILITY AND WIND SHEAR
WILL LIMIT SEVERE POTENTIAL.
HIGH TEMPERATURES WILL REACH THE LOWER TO MIDDLE 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THERE MAY BE A TEMPORARY LULL IN CONVECTION THIS EVENING WITH LOSS
OF DAYTIME HEATING. BY LATER TONIGHT...SURFACE LOW PRESSURE PUSHED
TO OHIO BY THE UPPER TROUGH WILL PRODUCE A NOTABLE INCREASE IN
FORCING. SHOWERS AND THUNDERSTORMS ARE A NEAR CERTAINTY IN
NORTHERN COUNTIES THAT WILL BE ON THE NORTH SIDE OF THE LOW TRACK. A
POTENT LOW LEVEL JET...COPIOUS MOISTURE AND A BAND OF DEFORMATION
WILL ALL COME INTO PLAY TO PRODUCE PERHAPS AS MUCH AS TWO INCHES
OF RAIN IN NORTHERN LOCATIONS. RAIN CHANCES WILL DECREASE TOWARD
THE SOUTH AWAY FROM THE MOST FAVORABLE FORCING.
WIDESPREAD SHOWERS WILL DIMINISH SUNDAY AS THE LOW MOVES EAST AND
THE LOW LEVEL FLOW BECOMES NORTHWEST. THUNDERSTORMS WILL BE LESS
EVIDENT ON SUNDAY IN A REGIME OF DECREASING INSTABILITY. HIGH
PRESSURE AND A DRY AIRMASS WILL MOVE IN MONDAY ON A NORTHWEST
FLOW ALOFT.
THE NORTHERLY LOW LEVEL FLOW BEHIND THE LOW WILL BRING COOLER
TEMPERATURES. HIGHS ON SUNDAY WILL VARY FROM THE LOW 60S NORTHWEST
UP TO THE UPPER 70S SOUTHEAST. HIGHS IN THE 60S ARE EXPECTED IN
MOST LOCATIONS ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
FORECAST HAS SHIFTED IN TIMING RETURN FLOW TO THE OHIO VALLEY. A
SLOWER SHIFT OF WINDS IN THE TUES-THURS TIME FRAME FROM EAST TO
EVENTUALLY SOUTH HAS HELPED KEEP A DRIER AND COOLER FORECAST FOR THE
BETTER PART OF NEXT WEEK.
A LARGE AREA OF HIGH PRESSURE NORTH OF THE GREAT LAKES REGION WILL
EXTEND A RIDGE SOUTHWEST INTO THE NORTHERN OHIO VALLEY TUESDAY THROUGH
WEDNESDAY. THE HIGH WILL SETTLE IN THE OHIO VALLEY ON WEDNESDAY
AND THEN MEANDER EASTWARD OVERNIGHT AND THURSDAY.
WITH THE NORTHEAST TO EAST WINDS HOLDING SWAY OVER THE REGION
THROUGH THIS TIME...HAVE REMOVED POPS UNTIL THURS AFTERNOON WHEN
SOME RETURN TO SOUTHERLY FLOW AND INCREASED MOISTURE WOULD BE
EXPECTED. TEMPS THROUGH THIS TIME WILL BE BELOW NORMAL...STARTING
WITH HIGHS IN THE UPPER 60S TO LOW 70S MONDAY RISING TO AROUND 80
WEDNESDAY AND LOW TO MID 80S FOR THE END OF THE WEEK. DRIER AIR WILL
PERMIT LOWS TO DIP INTO THE 50S MON NIGHT AND INCREASE TO AROUND 60
WED NIGHT...JUMPING TO THE MID 60S WHEN THE FLOW TURNS SOUTH AND
MOISTURE INCREASES LATE IN THE FORECAST.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
NUMEROUS TO WIDESPREAD SHOWERS AND THUNDERSTORMS ON THE RADAR
CURRENTLY. DUE TO COVERAGE HAVE ADDED TEMPO TSRA TO ALL TAF SITES
THIS AFTERNOON. EXPECT COVERAGE TO REMAIN WIDESPREAD THROUGH THE
AFTERNOON INTO EVENING. A SURFACE LOW WILL APPROACH FROM THE
SOUTHWEST LATER THIS EVENING WHICH SHOULD HELP TO TRANSITION BEST
COVERAGE FARTHER NORTH. HIGH RES MODELS THEN ARE INDICATING A LINE
OF SHOWERS AND THUNDERSTORMS PUSHING INTO THE AREA EARLY TOMORROW
MORNING ALONG A FRONT. HIGH RES MODELS THEN WEAKEN THE N-S LINE AS
IT MOVES INTO THE AREA. AS THE LOW MOVES NORTHEAST OF THE AREA
MODELS CONTINUE TO SHOW DEVELOPMENT OF MVFR CIGS. NAM AND GFS
FORECAST SOUNDINGS SHOW IFR CIGS OFF TO THE WEST WITH MVFR TOWARDS
THE EAST. FOR NOW HAVE TRENDED CIGS DOWN.
OUTLOOK...SHOWERS AND THUNDERSTORMS ARE POSSIBLE SUNDAY.
POTENTIAL EXISTS FOR MVFR OR IFR CIGS LATE SUNDAY THROUGH MONDAY
MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO/HAINES
NEAR TERM...CONIGLIO/HAINES
SHORT TERM...CONIGLIO
LONG TERM...FRANKS
AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1250 PM CDT SAT MAY 30 2015
.DISCUSSION...
UPDATED FOR THE 18Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 850 AM CDT SAT MAY 30 2015/
UPDATE...
UPDATED FOR A SLIGHT REDUCTION OF POPS IN THE DELTA THIS MORNING.
DISCUSSION...
WATER VAPOR IMAGERY SHOWING MCV ROTATING NORTHEASTWARD ACROSS
ARKANSAS THIS MORNING...WITH RADAR INDICATING A BETTER
CONCENTRATION OF MEASURABLE RAINFALL NEAR THE CENTER AND AN ILL-
DEFINED DRY SLOT ROTATING UP ALONG THE SOUTHWEST DELTA COUNTIES.
HAVE REDUCED POPS IN THIS LATTER REGION TO INCLUDE THE MEMPHIS
METRO THROUGH NOON. AFTER WHICH...THE BRUNT OF THE STORMS WILL RUN
EAST OF A UNION CITY TENNESSEE...TO AN OXFORD MISSISSIPPI
LINE...WITH THE BEST THREAT FOR A SEVERE STORM RUNNING ACROSS THE
NORTHEAST COUNTIES ALONG THE LOWER TENNESSEE RIVER VALLEY.
THE REMAINDER OF THE MORNING FORECAST APPEARS TO BE ON TRACK.
JAB
&&
.PREV DISCUSSION... /ISSUED 424 AM CDT SAT MAY 30 2015/
EARLY MORNING GOES WATER VAPOR IMAGERY SHOWED A WELL DEFINED
UPPER LEVEL SHORTWAVE CENTERED JUST SOUTH OF FORT SMITH
AR...MOVING EAST. NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS WERE
SPREADING NORTHEAST THROUGH EASTERN AR AHEAD OF THIS FEATURE.
SHOWERS AND THUNDERSTORMS WILL LIKELY SPREAD EAST THROUGH MOST OF
THE MIDSOUTH THIS MORNING. 07Z HRRR MODEL SHOWS BEST RAIN CHANCES
SHIFTING TO NORTHEAST MS AND AREAS OF WEST TN NEAR THE TN RIVER BY
MIDAFTERNOON. A FEW WRAP AROUND SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE FURTHER WEST...ALONG AND BEHIND A SURFACE COLD FRONT. ANY
WRAP AROUND SHOWERS SHOULD DISSIPATE THIS EVENING... AS THE
SHORTWAVE LIFTS OUT AND DAYTIME HEATING ENDS.
A SECONDARY SHORTWAVE WILL DROP FROM THE OZARKS INTO THE MIDSOUTH
ON SUNDAY...WITH NORTHEAST MS BEST POSITIONED TO RECEIVE
MEASURABLE RAINFALL. THIS SECONDARY SHORTWAVE WILL EXIT SUNDAY
EVENING... LEAVING DRIER DEEP NORTHWEST FLOW PREVAILING OVER ALL
OF THE MIDSOUTH BY SUNDAY NIGHT.
THE MONDAY THROUGH WEDNESDAY PERIODS APPEAR DRIER THAN EARLIER
FORECAST...WITH WEAKENING NORTHWEST FLOW ALOFT GIVING WAY TO
AN ENCROACHING UPPER LEVEL RIDGE FROM THE SOUTHERN PLAINS. THE
GFS AND ECMWF MODELS CONTINUE TO SHOW DIFFERING SOLUTIONS TO A
DEVELOPING CUTOFF LOW OVER THE SOUTHEAST STATES. NEITHER MODEL
RETROGRADES THE UPPER LOW SUFFICIENTLY TO BRING APPRECIABLE RAIN
CHANCES TO THE MIDSOUTH UNTIL LATER IN THE WEEK...AND ONLY THE GFS
SHOWS THIS SCENARIO. IF THE ECMWF VERIFIES...WE MAY SEE LOWER 90S
OVER MUCH OF THE MIDSOUTH LATE IN THE WEEK. FOR NOW...HAVE KEPT
THE EXTENDED FORECAST HIGHS NEAR THE MODEL ENSEMBLE AVERAGE...BUT
THERE MAY BE A WARMER TREND DEVELOPING FOR LATER NEXT WEEK.
PWB
&&
.AVIATION...
18Z TAF CYCLE
AN MCV CONTINUES TO LIFT NORTHEAST ACROSS NORTHEAST ARKANSAS WITH
NUMEROUS SHOWERS AND THUNDERSTORMS EAST OF THE MISSISSIPPI RIVER.
TEMPOS FOR TSRA HAVE BEEN INCLUDED AT KMKL AND KTUP FOR THE
AFTERNOON HOURS DURING PEAK HEATING ALONG WITH MVFR CIG/VSBY
REDUCTIONS. AT KMEM AND KJBR WILL CARRY VCTS ALONG WITH VFR CIGS
WHERE COVERAGE IS LOWER.
THERE WILL BE A BREAK IN CONVECTION THIS EVENING WITH A RETURN TO
AREAWIDE VFR CONDITIONS. LATER THIS EVENING INTO THE MORNING HOURS
ON SUNDAY...ANOTHER SHORTWAVE LIFTING NORTHEAST FROM TEXAS SHOULD
TRIGGER ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ALONG WITH MVFR
CIG/VSBY REDUCTIONS. MVFR CIGS SHOULD PERSIST THROUGH MUCH OF THE
MORNING HOURS SUNDAY.
JLH
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
442 PM CDT SAT MAY 30 2015
.UPDATE...
HAVE DROPPED SEVERE THUNDERSTORM WATCH 244 FOR THE COUNTIES ALONG
THE SOUTHERN RIO GRANDE PLAINS. THE REMNANTS OF THE EARLIER MCS
HAVE WEAKENED AND PUSHED EAST OF THE WATCH AREA. OTHER AREAS
ACROSS SOUTH CENTRAL TEXAS ARE VERY PULSE LIKE. HAVE GOTTEN
SEVERAL REPORTS OF SUB-SEVERE HAIL OUT OF THESE STORMS AND LOTS OF
HEAVY RAINFALL. HEAVY RAINFALL CONTINUES TO BE THE MAIN THREAT
WITH STRONG GUSTY THUNDERSTORM WINDS AND SMALL HAIL ALSO POSSIBLE.
WILL CONTINUE TO WATCH THESE STORMS AS THEY PUSH SOUTH AND COLLIDE
WITH THE SEA BREEZE COMING UP FROM THE SOUTH LATER THIS EVENING.
NO OTHER UPDATES TO THE ONGOING FORECAST AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 308 PM CDT SAT MAY 30 2015/
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
TRICKY FORECAST REMAINS FOR THE AFTERNOON AND OVERNIGHT PERIOD
ACROSS SOUTH CENTRAL TEXAS. THE LEFT OVER OUTFLOW BOUNDARY FROM
KERRVILLE TO SAN MARCOS TO BASTROP HAS BEGUN TO LIGHT UP WITH
STORMS WITHIN THE LAST HOUR OR SO. THE MCS THAT BEGUN THIS MORNING
TO OUR NORTHWEST ACROSS FORT STOCKTON HAS DEVELOPED SOUTHWARD AND
TAKEN A MORE EASTERLY TRACK AND NOW EXTENDS FROM UVALDE SOUTH TO
CARRIZO SPRINGS AS A BROKEN LINE OF STORMS.
THE HRRR HAS BEEN THE MODEL WITH THE BEST HANDLE ON BOTH FEATURES.
MOST OF THE OTHER MESOSCALE MODELS (TEXAS TECH WRF/ARM/NMM) ALL DO
NOT HAVE THE REMNANTS OF THE MCS TO THE WEST. THE HRRR PUSHES THE
THE MCS TO THE EAST AND CONTINUES TO WEAKEN IT WHILE MOVING THE
LINE OF SHOWERS AND STORMS SOUTH WITH THE BOUNDARY. IT THEN SEEM
TO DEVELOP A FEW MORE ISOLATED SHOWERS AND STORMS ALONG THE WEAK
FRONT AS IT PUSHES TO THE SOUTH. THE MAJORITY OF THE CONVECTION
WILL PUSH TO THE SOUTH AND EAST BY ABOUT 8 PM TONIGHT WITH
ISOLATED ACTIVITY CONTINUING THROUGH ABOUT MIDNIGHT. THE MAIN
THREATS WITH THESE STORMS WILL BE STRONG GUSTY WINDS...FREQUENT
LIGHTNING...AND SMALL HAIL. LOCALLY HEAVY RAINFALL WILL ALSO BE
POSSIBLE WITH THESE STORMS...ESPECIALLY THOSE THAT ARE SLOWLY
MOVING TO THE SOUTH. THE FLASH FLOOD WATCH CONTINUES ACROSS THE
WHOLE AREA. RAINFALL AMOUNTS WILL AVERAGE AROUND AN INCH WITH
HIGHER TOTALS OF TWO TO THREE INCHES POSSIBLE. IT IS SET TO EXPIRE
AT 7 AM TOMORROW...BUT COULD POSSIBLY BE CANCELED EARLY ONCE
STORMS PUSH OUT OF THE AREA TONIGHT. LATER SHIFTS WILL RE-
EVALUATE AND MAKE CHANGES TO THE WATCH AS NEEDED.
GLOBAL MODELS SHOW SHOWERS AND STORMS CONTINUING ACROSS THE
COASTAL PLAINS LATE TONIGHT AND SUNDAY MORNING ALONG THE WEAK COLD
FRONT AS IT CONTINUES TO PUSH SOUTH. WITH THE MOIST ENVIRONMENT
AROUND THE AREA WE COULD SEE AN ISOLATED SHOWER OR THUNDERSTORM
THROUGHOUT THE AFTERNOON SUNDAY...BUT CHANCES REMAIN LOW. ONCE THE
FRONT PUSHES WELL TO OUR SOUTH LATE SUNDAY THE LONG AWAITED DRYING
TREND WILL BEGIN. SUNDAY NIGHT WILL BE MOSTLY CLEAR AND PLEASANT
WITH LOWS ACROSS MUCH OF SOUTH CENTRAL TEXAS IN THE LOW TO MID
60S.
LONG TERM (MONDAY THROUGH SATURDAY)...
THE UPPER LEVEL PATTERN FOR MUCH OF NEXT WEEK WILL BE THE SAME AS
A TROUGH OF LOW PRESSURE WILL DROP DOWN INTO THE SOUTHEAST UNITED
STATES AND BECOME CUT OFF FROM THE FLOW. AT THE SAME TIME A RIDGE
OF HIGH PRESSURE BUILDS OVER NORTHERN MEXICO AND THE SOUTHWEST
U.S. THIS WILL KEEP SOUTH CENTRAL TEXAS IN NORTHWEST FLOW ALOFT
AND KEEP THE AREA MOSTLY DRY. AN ISOLATED SHOWER OR THUNDERSTORM
ALONG THE TEXAS SEA BREEZE LOOKS TO BE THE ONLY CHANCE FOR
PRECIPITATION THROUGH THE END OF NEXT WEEK. SOUTH CENTRAL TEXAS
WILL WELCOME THE FIRST WEEK OF JUNE AS A CHANCE TO DRY OUT FROM A
VERY WET AND STORMY MONTH OF MAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 66 84 64 86 66 / 50 20 - 10 -
AUSTIN BERGSTROM INTL AIRPORT 64 83 61 85 64 / 50 20 - 10 -
NEW BRAUNFELS MUNI AIRPORT 67 85 64 87 66 / 50 30 - - -
BURNET MUNI AIRPORT 64 81 62 84 65 / 40 20 - 10 -
DEL RIO INTL AIRPORT 66 87 69 89 70 / 40 30 - 20 -
GEORGETOWN MUNI AIRPORT 65 82 62 84 65 / 40 20 - - -
HONDO MUNI AIRPORT 66 85 65 87 66 / 50 30 - 10 -
SAN MARCOS MUNI AIRPORT 65 83 63 85 65 / 50 20 - - -
LA GRANGE - FAYETTE REGIONAL 68 84 63 85 67 / 60 40 - 20 -
SAN ANTONIO INTL AIRPORT 67 85 66 86 68 / 50 30 - 10 -
STINSON MUNI AIRPORT 68 85 67 86 67 / 60 30 - 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...
KINNEY...LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...
UVALDE...VAL VERDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...OAKS
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
308 PM CDT SAT MAY 30 2015
.SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
TRICKY FORECAST REMAINS FOR THE AFTERNOON AND OVERNIGHT PERIOD
ACROSS SOUTH CENTRAL TEXAS. THE LEFT OVER OUTFLOW BOUNDARY FROM
KERRVILLE TO SAN MARCOS TO BASTROP HAS BEGUN TO LIGHT UP WITH
STORMS WITHIN THE LAST HOUR OR SO. THE MCS THAT BEGUN THIS MORNING
TO OUR NORTHWEST ACROSS FORT STOCKTON HAS DEVELOPED SOUTHWARD AND
TAKEN A MORE EASTERLY TRACK AND NOW EXTENDS FROM UVALDE SOUTH TO
CARRIZO SPRINGS AS A BROKEN LINE OF STORMS.
THE HRRR HAS BEEN THE MODEL WITH THE BEST HANDLE ON BOTH FEATURES.
MOST OF THE OTHER MESOSCALE MODELS (TEXAS TECH WRF/ARM/NMM) ALL DO
NOT HAVE THE REMNANTS OF THE MCS TO THE WEST. THE HRRR PUSHES THE
THE MCS TO THE EAST AND CONTINUES TO WEAKEN IT WHILE MOVIING THE
LINE OF SHOWERS AND STORMS SOUTH WITH THE BOUNDARY. IT THEN SEEM
TO DEVELOP A FEW MORE ISOLATED SHOWERS AND STORMS ALONG THE WEAK
FRONT AS IT PUSHES TO THE SOUTH. THE MAJORITY OF THE CONVECTION
WILL PUSH TO THE SOUTH AND EAST BY ABOUT 8 PM TONIGHT WITH
ISOLATED ACTIVITY CONTINUING THROUGH ABOUT MIDNIGHT. THE MAIN
THREATS WITH THESE STORMS WILL BE STRONG GUSTY WINDS...FREQUENT
LIGHTNING...AND SMALL HAIL. LOCALLY HEAVY RAINFALL WILL ALSO BE
POSSIBLE WITH THESE STORMS...ESPECIALLY THOSE THAT ARE SLOWLY
MOVING TO THE SOUTH. THE FLASH FLOOD WATCH CONTINUES ACROSS THE
WHOLE AREA. RAINFALL AMOUNTS WILL AVERAGE AROUND AN INCH WITH
HIGHER TOTALS OF TWO TO THREE INCHES POSSIBLE. IT IS SET TO
EXPIRE AT 7 AM TOMORROW...BUT COULD POSSIBLY BE CANCELED EARLY
ONCE STORMS PUSH OUT OF THE AREA TONIGHT. LATER SHIFTS WILL RE-
EVALUATE AND MAKE CHANGES TO THE WATCH AS NEEDED.
GLOBAL MODELS SHOW SHOWERS AND STORMS CONTINUING ACROSS THE
COASTAL PLAINS LATE TONIGHT AND SUNDAY MORNING ALONG THE WEAK COLD
FRONT AS IT CONTINUES TO PUSH SOUTH. WITH THE MOIST ENVIRONMENT
AROUND THE AREA WE COULD SEE AN ISOLATED SHOWER OR THUNDERSTORM
THROUGHOUT THE AFTERNOON SUNDAY...BUT CHANCES REMAIN LOW. ONCE THE
FRONT PUSHES WELL TO OUR SOUTH LATE SUNDAY THE LONG AWAITED DRYING
TREND WILL BEGIN. SUNDAY NIGHT WILL BE MOSTLY CLEAR AND PLEASANT
WITH LOWS ACROSS MUCH OF SOUTH CENTRAL TEXAS IN THE LOW TO MID
60S.
&&
.LONG TERM (MONDAY THROUGH SATURDAY)...
THE UPPER LEVEL PATTERN FOR MUCH OF NEXT WEEK WILL BE THE SAME AS
A TROUGH OF LOW PRESSURE WILL DROP DOWN INTO THE SOUTHEAST UNITED
STATES AND BECOME CUT OFF FROM THE FLOW. AT THE SAME TIME A RIDGE
OF HIGH PRESSURE BUILDS OVER NORTHERN MEXICO AND THE SOUTHWEST
U.S. THIS WILL KEEP SOUTH CENTRAL TEXAS IN NORTHWEST FLOW ALOFT
AND KEEP THE AREA MOSTLY DRY. AN ISOLATED SHOWER OR THUNDERSTORM
ALONG THE TEXAS SEA BREEZE LOOKS TO BE THE ONLY CHANCE FOR
PRECIPITATION THROUGH THE END OF NEXT WEEK. SOUTH CENTRAL TEXAS
WILL WELCOME THE FIRST WEEK OF JUNE AS A CHANCE TO DRY OUT FROM A
VERY WET AND STORMY MONTH OF MAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 66 84 64 86 66 / 50 20 - 10 -
AUSTIN BERGSTROM INTL AIRPORT 64 83 61 85 64 / 50 20 - 10 -
NEW BRAUNFELS MUNI AIRPORT 67 85 64 87 66 / 50 30 - - -
BURNET MUNI AIRPORT 64 81 62 84 65 / 40 20 - 10 -
DEL RIO INTL AIRPORT 66 87 69 89 70 / 40 30 - 20 -
GEORGETOWN MUNI AIRPORT 65 82 62 84 65 / 40 20 - - -
HONDO MUNI AIRPORT 66 85 65 87 66 / 50 30 - 10 -
SAN MARCOS MUNI AIRPORT 65 83 63 85 65 / 50 20 - - -
LA GRANGE - FAYETTE REGIONAL 68 84 63 85 67 / 60 40 - 20 -
SAN ANTONIO INTL AIRPORT 67 85 66 86 68 / 50 30 - 10 -
STINSON MUNI AIRPORT 68 85 67 86 67 / 60 30 - 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...
KINNEY...LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...
UVALDE...VAL VERDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
255 PM CDT SAT MAY 30 2015
...FLASH FLOOD WATCH IN EFFECT THROUGH TONIGHT...
.MESOANALYSIS...
19Z ANALYSIS...VIS SATELLITE IMAGERY SHOWS SEA BREEZE BOUNDARY
PUSHING INLAND FROM HOUSTON TO VICTORIA. THERE IS ALSO A FRONTAL
BOUNDARY PUSHING THROUGH C TX NOW THROUGH WACO/TEMPLE AREAS. VIS
SATELLITE ALSO SHOWS AREAS OF ENHANCED CU DEVELOPMENT FROM
COLUMBUS TO CONROE WITH ANOTHER AREA POSSIBLY ALONG AN OLD OUTFLOW
BOUNDARY FROM CROCKETT TO COLLEGE STATION AND THEN NEAR SAN
ANTONIO. WATER VAPOR IMAGERY SHOWS SHORT WAVE TROUGH MOVING
THROUGH N C TX AND W TX WHICH HAS ALREADY INITIATED CONVECTION
DOWN ALONG THE RIO GRANDE. CONVECTION ALONG THE OUT FLOW OVER C TX
AND HILL COUNTRY LOOKS TO BE GETTING SOME ENHANCEMENT FROM
ASSOCIATED LIFT. SATELLITE DERIVED PRECIP WATER VALUES RANGE FROM
1.6 TO 1.7 INCHES IN THE AREAS OF ENHANCED CONVECTION. SPC
MESOANALYSIS SHOWS INSTABILITY BUILDING UP TO AROUND 3000 J/KG
OVER THE AREA WITH VERY LITTLE CIN. CHANGES IN CAPE/CIN THE LAST 3
HRS HAVE BEEN TO INCREASE CAPE AND DECREASE CIN SO STARTING TO SEE
THE AIRMASS DESTABILIZE ACROSS THE AREA.
THINK THAT CONVECTION SHOULD BE INITIATING THE NEXT COUPLE OF
HOURS WITH AREAS IN THE UPPER 80S ALREADY. SUSPECT THAT IF PRECIP
WATER VALUES WERE HIGHER STORMS WOULD BE FORMING ALREADY. RECENT
TRENDS IN HRRR STILL DEVELOP CONVECTION OVER THE AREA AS DO 12Z
WRF ARW/NMM RUNS. EVEN TX TECH WRF IS AGGRESSIVE WITH
THUNDERSTORM DEVELOPMENT 21Z SAT TO 03Z. ONLY CONDITIONS THAT MAY
BE KEEPING THUNDERSTORMS FROM FORMING IS SLIGHTLY LOWER MOISTURE
THAN EXPECTED AND PERHAPS SOME WEAK RIDGING AT 700MB. THAT SAID
THERE IS A COLD POCKET OF -13C AT 500MB OVER C TX THAT MAY PUSH
OVER THE AREA LATER THIS EVENING. TROUGH AXIS MAY BE ENOUGH TO
WEAKEN ANY MID LEVEL RIDGING.
ONCE STORMS DO FORM...THINKING IS THAT STORM MOTIONS WILL BE VERY
SLOW. BUT HI RES MODELS SEEM TO THINK A LINE OF STORMS COULD FORM
WITH A COLD POOL. THE GOOD NEWS WITH THIS IS THAT STORMS MAY PUSH
THROUGH THE AREA AND DECREASE THE THREAT FOR HEAVY
RAINFALL/FLOODING. STILL NEED TO WATCH BECAUSE ANY STORMS THAT
EXCEED RAIN RATES OF 2 INCHES AN HOUR COULD STILL POTENTIALLY
CAUSE FLOODING PROBLEMS. IN GENERAL ANY AREA THAT GETS OVER 3
INCHES QUICKLY COULD HAVE FLOODING PROBLEMS. SHOULD STORMS MOVE
SLOWER THE EVEN STORM WITH 1-2 INCHES AN HOUR COULD CAUSE PROBLEM
IF THEY PERSIST FOR ONLY 2-3 HOURS. FOR THIS REASON WE
WILL KEEP THE FLASH FLOOD WATCH GOING AS IS.
SHORT TERM...
FRONTAL BOUNDARY SHOULD PUSH OFF THE COAST SUNDAY WITH LOWER
DEWPOINTS FORECAST TO MOVE INTO THE AREA. MODELS SHOW PRECIP WATER
VALUES DROPPING TO UNDER 1 INCH FOR MONDAY. PRECIP WATER VALUES
COULD REMAIN UNDER 1.5 INCHES THROUGH THE MIDDLE OF THE WEEK. FOR
NOW HAVE CONTINUED TO TRIM BACK RAIN CHANCES. UPPER LOW THAT WAS
PROGGED TO CLOSE OFF OVER LA IS NOW PROGRESSIVE WITH BOTH THE
GFS/ECMWF SO LOOKS LIKE NORTHERLY FLOW ALOFT WILL KEEP RAIN
CHANCES LOW.
LONG TERM...
THUR/FRI/SAT FOR THE COMING WEEK BOTH THE GFS/ECMWF ARE IN GOOD
AGREEMENT WITH UPPER LEVEL RIDGING BUILDING OVER TX FOR THE
BEGINNING OF JUNE. THIS SHOULD KEEP RAIN CHANCES OUT OF THE
FORECAST AND ALLOW FOR GROUNDS TO DRY OUT. MAX TEMPS MAY REACH THE
UPPER 80S TO LOW 90S EACH DAY. RAIN CHANCES KEPT IN THE 10-20
PERCENT RANGE.
39
&&
.MARINE...
RELATIVELY BENIGN WITH WINDS AROUND 5 KNOTS AT THE MOMENT AND SEAS
OF 2 FEET. THIS SHOULD PREVAIL TONIGHT BUT WILL HAVE TO WATCH THE
STYSEM COMING DOWN THE RIO GRANDE AND EXTENDING INTO THE AUSTIN AREA
TO MAKE SURE THEY DON`T TURN EAST. IF SO THEN STRONG GUSTY WINDS
COULD ACCOMPANY THE STORMS. COLD FRONT SHOULD ARRIVE NEAR THE COAST
AROUND 4 AM PLUS OR MINUS A COUPLE OF HOURS. NORTHERLY WINDS IN THE
MORNING RELAX AS ANOTHER SEABREEZE FORMS. A LITTLE STRONGER
NORTHERLY FLOW SUNDAY NIGHT MAY REACH SUSTAINED NEAR 10 KNOTS.
ONSHORE FLOW RESUMES BY LATE MONDAY AND CONTINUES UNTIL A SECOND
PUSH OF DRIER AIR ARRIVES EARLY TUESDAY BUT THIS ONE IS SHORTER
LIVED. WEDNESDAY IS RETURN FLOW AND MAY FINALLY SEE SUSTAINED 10-15
KNOT SE-SSE WINDS BY WEDNESDAY NIGHT.
TIDE LEVELS ONE HALF FOOT TO ONE FOOT ABOVE NORMAL THROUGH TONIGHT
THEN SHOULD SUBSIDE SUNDAY WITH ONSET OF THE MORE NORTHERLY WINDS.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 67 82 64 85 68 / 50 20 10 10 10
HOUSTON (IAH) 69 84 66 87 68 / 60 40 20 10 10
GALVESTON (GLS) 74 84 73 85 74 / 50 50 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...45
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
150 PM CDT SAT MAY 30 2015
.AVIATION...
SUBSIDENCE WITH 700-500MB RIDGING APPARENT WITH DEMISE OF MOST OF
THE STORMS SO FAR THIS AFTERNOON. BUT SEABREEZE IS SPREADING
INLAND AND RIDGING ALOFT IS SLIDING EAST SO FULLY EXPECT THAT WITH
87-90 DEGREE READINGS THIS AFTERNOON THAT STORMS WILL FIRE UP
ALONG THE SEABREEZE ROUGHLY ALONG THE HIGHWAY 59 CORRIDOR SW-NE
THROUGH THE HOUSTON TAF SITES. STORMS WILL BE SLOW MOVERS AND
CAPABLE OF HEAVY DOWNPOURS AND REDUCED VISBY WITH GUSTY WINDS.
21-01Z SHOULD BE THE TIME THEY FOCUS ALONG THE SEABREEZE THEN
SHOULD WANE IN THE EVENING. BOUNDARY NEARING A JAS/UTS/CLL/AUS
LINE SHOULD CONTINUE TO MARCH SOUTH INTO AN INCREASINGLY UNSTABLE
ATMOSPHERE AND WILL HAVE TO WATCH FOR THIS BOUNDARY TO BECOME AS
ACTIVE AS THE SEABREEZE AND FOR ANY POTENTIAL COLLISIONS LATE THIS
AFTERNOON AND EVENING. AGAIN SLOW STORM MOTIONS EVEN ALONG THIS
BOUNDARY. DRIER AIR BUILDS INTO THE AREA OVERNIGHT AND NORTHERLY
FLOW ON TAP SUNDAY...RAIN CHANCES MAY BE FOCUSED NEAR THE COAST.
45
&&
.PREV DISCUSSION... /ISSUED 1056 AM CDT SAT MAY 30 2015/
DISCUSSION...
OUTFLOW BOUNDARY HAS PUSHED INTO SE TX FROM CONVECTION OVER N TX
THIS MORNING. THIS ALONG WITH DIURNAL HEATING HAVE ALLOWED FOR A
FEW SCT SHOWERS AND STORMS TO FORM MAINLY ALONG US 59 FROM HOUSTON
TO LUFKIN. OTHER ISO CONVECTIVE CELLS HAVE FORMED FROM COLUMBUS
TO PALACIOS. MOST OF THIS ACTIVITY SEEMS TO PULSE IN INTENSITY
WITH MAYBE RAIN RATES OF HALF INCH AN HOUR. THE MAIN TREND TO NOTE
IS THAT STORMS ARE NOT MOVING VERY MUCH. LATEST SFC ANALYSIS HAS
COLD FRONT PUSHING THROUGH N TX INTO W C TX. FRONT SHOULD BE
MAKING ITS WAY TO SE TX THIS AFTERNOON. BEGINNING OF THE FRONT
SHOULD REACH COLLEGE STATION/CROCKETT LINE 3-4PM AND THEN HOUSTON
AREA 6-7PM BASED ON LATEST HRRR RUN.
LATEST SHORT RANGE GUIDANCE STILL HAS STORMS FORMING ON SEA
BREEZE EARLY AFTERNOON AND THEN ALONG THE FRONT LATER THIS
AFTERNOON. MAIN CONCERN WILL BE FOR HEAVY RAINFALL AS STORMS WILL
NOT BE MOVING QUICKLY. RAIN RATES OF 1-2 INCHES FOR A COUPLE OF
HRS WILL CAUSE FLOODING PROBLEMS. WE ARE STILL LOOKING AT VERY
SATURATED GROUNDS WHICH MEANS EVEN 2-3 INCHES OF RAIN COULD CAUSE
FLOODING PROBLEMS. FOR NOW WE WILL KEEP FLASH FLOOD WATCH AS IS
BUT WILL EVALUATE THE NEED FOR A WATCH FOR SOME OF THE NORTHERN
PORTIONS OF THE FORECAST AREA DEPENDING ON THE EVOLUTION OF
CONVECTION.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 85 67 81 64 85 / 70 50 30 10 20
HOUSTON (IAH) 87 70 83 66 87 / 80 70 50 20 30
GALVESTON (GLS) 85 75 81 74 81 / 50 50 50 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...45
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1257 PM CDT SAT MAY 30 2015
.AVIATION...
/18Z TAFS/
A LINE OF STORMS LEAVING KDRT WILL CONTINUE TO PUSH TO THE EAST
SOUTHEAST THIS AFTERNOON. EMBEDDED STRONG TO SEVERE STORMS ARE
POSSIBLE WITH THIS LINE AS IT MERGES WITH OTHER BOUNDARIES AND A
WEAK COLD FRONT EXPECTED TO MOVE ACROSS THE AREA MID TO LATE
AFTERNOON. MVFR CONDITIONS ARE FORECAST TO PREVAIL FOR MOST OF THE
FORECAST PERIOD WITH IFR VBSYS WITH STORMS MOVING ACROSS AREA
TERMINALS ALONG THE I-35 LATE THIS AFTERNOON AND EVENING.
&&
.PREV DISCUSSION... /ISSUED 934 AM CDT SAT MAY 30 2015/
UPDATE...
CURRENT CONDITIONS ACROSS THE AREA SHOW AN OUTFLOW BOUNDARY FROM
UVALDE TO SAN ANTONIO TO LA GRANGE LEFT OVER FROM THE LINE OF
STORMS THAT PUSHED THROUGH THIS MORNING. BEHIND THIS LINE SKIES
HAVE CLEARED OUR ALLOWING TEMPERATURES TO WARM. ACROSS THE WEST
THE NEXT LINE OF SHOWERS AND THUNDERSTORMS IS PUSHING INTO VAL
VERDE COUNTY.
HAVE ADJUSTED THE POPS/QPF/WEATHER GRIDS TO FOCUS THE HIGHEST
CHANCES OF PRECIPITATION ACROSS THE WEST THIS MORNING WITH THIS
LINE. RECENT RUNS OF THE HRRR TAKE THIS COMPLEX TO THE SOUTHEAST
ALONG THE RIO GRANDE RIVER AND THE RIO GRANDE PLAINS. THE MAIN
THREATS WILL BE BRIEF GUSTY WINDS UP TO 40 MPH AND SOME SMALL
HAIL. BRIEF HEAVY RAINFALL WILL ALSO BE POSSIBLE AS THIS LINE
RACES TO THE SOUTHEAST.
THE HIGH RESOLUTION MODELS THEN DEVELOP MORE SHOWERS AND
THUNDERSTORMS LATER THIS AFTERNOON ALONG THE LEFT OVER OUTFLOW
BOUNDARIES DUE TO NOT ONLY DAY TIME HEATING BUT ALSO A WEAK
FRONTAL BOUNDARY. LEFT THE FLASH FLOOD WATCH AS IS FOR NOW.
CURRENT THINKING IS THAT MOST AREAS WILL SEE BETWEEN HALF AN INCH
TO AN INCH THROUGH TODAY AND THIS EVENING...WITH ISOLATED TOTALS
UP TO 2 AND 3 INCHES WITH THE SLOWER MOVING OR MORE INTENSE
THUNDERSTORMS.
PREV DISCUSSION... /ISSUED 642 AM CDT SAT MAY 30 2015/
AVIATION...
SHRA/ISOLD TSRA CURRENTLY ALONG A BOUNDARY FROM KDRT TO KERV TO
KBMQ TO KILE WILL SLOWLY WEAKEN AS IT MOVES TO THE SE ACROSS SOUTH
CENTRAL TEXAS THIS MORNING. BOUNDARIES AND A COLD FRONTAL PASSAGE
WILL LEAD TO SHRA/TSRA MIDDAY INTO TONIGHT. HAVE GONE WITH
SHRA/TSRA AT THE TAF SITES FOR 12Z TO 14Z AND TEMPOS FOR TSRA FOR
THIS AFTERNOON INTO EVENING WITH VCSH OTHERWISE. IFR/MVFR CIGS
BECOME VFR WITH THE PASSAGE OF THE BOUNDARY AND WILL GENERALLY
REMAIN VFR FOR THE REST OF TODAY THROUGH SUNDAY MORNING...EXCEPT
FOR MVFR CIGS IN SHRA/TSRA AND POSSIBLY A PERIOD TONIGHT. S TO SE
WINDS 5 TO 10 KTS WILL TURN TO N TO NE WITH THE SURFACE BOUNDARIES
AND FRONTAL PASSAGE. SOME GUSTS TO 50 KTS AND GR ARE POSSIBLE IN
AND NEAR TSRA.
PREV DISCUSSION... /ISSUED 253 AM CDT SAT MAY 30 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
THE MAIN HIGHLIGHT THIS PERIOD WILL FOCUS ON THE CURRENTLY
ONGOING THUNDERSTORM COMPLEX N/NW OF THE REGION AND ITS EVOLUTION
THROUGH THE DAY TODAY THAT COULD RESULT IN LOCALLY HEAVY RAINFALL
AND FLASH FLOODING. WILL BUMP UP THE TIMING OF THE FLASH FLOOD
WATCH TO START AT 4AM THIS MORNING GIVEN CURRENT TRENDS AND
CONTINUE IT THROUGH 7AM SUNDAY.
CURRENT RADAR IMAGERY ACROSS THE STATE OF TEXAS REVEALS A SOUTHWARD
TRAVELING THUNDERSTORM COMPLEX. RADAR TRENDS INDICATE A GUST
FRONT/OUTFLOW BOUNDARY HAD DEVELOPED OUT WELL AHEAD OF THE COMPLEX
AS IT PUSHES SOUTH AND THIS WILL LIKELY UNDERCUT THE UPDRAFTS AND
KEEP THEM IN A WEAKENED STATE. THE QUESTION BECOMES HOW WILL THIS
OUTFLOW BOUNDARY OR ANOTHER POSSIBLE BOUNDARY FROM THE STORMS
CURRENTLY IN NEW MEXICO AND HOW THEY MAY INTERACT WITH A SEA-BREEZE
WILL SHAPE TODAY`S RAIN AND THUNDERSTORM POTENTIAL. TODAY`S
RESULTANT STORM ACTIVITY WILL BE HIGHLY MESOSCALE DRIVEN WITH SOME
AID ON THE SYNOPTIC SCALE AS A WEAK SHORTWAVE TROUGH WILL BE OVER
THE REGION.
OVERALL, FEEL HRRR/RAP HAVE DECENT HANDLE ON CURRENT SITUATION AND
OVERALL SIGNALS FROM SPC SSEO SUGGEST THAT SOUTHWARD PROGRESSING
BOUNDARY AND WEAKENING STORMS WILL ENTER HILL COUNTRY AROUND 4-5AM.
GENERAL BAND OF LIGHT TO MODERATE RAIN MAY MAKE IT TO THE I-35
CORRIDOR NEAR 8-10AM WITH SOUTHERN AREAS REMAINING DRY THROUGH NOON.
THE QUESTION WILL BE HOW MUCH MOMENTUM WILL THIS BOUNDARY HAVE AND
HOW MUCH CLOUD COVER COULD RESULT. IF MOMENTUM SLOWS AND SETS UP A
CONVERGENCE BOUNDARY WITH THE SEA-BREEZE IN AN UNSTABLE ENVIRONMENT
THEN THE CONDITIONS WILL BE SET FOR LOCALIZED SHOWERS AND STORMS
WITH LOCALIZED HEAVY RAINFALL DURING THE AFTERNOON. A SECOND
SCENARIO IS THAT THE OUTFLOW CONTINUES THROUGH MUCH OF THE REGION
THROUGH LATE MORNING AND A SECOND BOUNDARY (FROM CURRENT NEW MEXICO
STORMS) IN COMBO WITH WEAK FRONT IN ASSOCIATION WITH THE SHORTWAVE
TROUGH AND ALSO ACTS TO HELP TRIGGER LOCALIZED HEAVY SHOWERS AND
STORMS. A THIRD SCENARIO WOULD BE THE FIRST BOUNDARY HANGS UP OVER
THE REGION BUT WITH SLIGHTLY STRONGER CONVECTION INITIALLY THIS
MORNING AND CREATES MORE CLOUD COVER/STRATIFORM RAIN. THIS WOULD
DEPLETE SOME OF THE AVAILABLE BUOYANT ENERGY LATER THIS AFTERNOON BY
KEEPING TEMPS DOWN AND KEEP THE ATMOSPHERE SLIGHTLY MORE STABLE. AT
THIS STAGE...FEEL THE FIRST TWO SCENARIOS ARE MORE LIKELY AND HAVE A
CONCERN FOR LOCALIZED HEAVY RAINFALL OF 1-2 INCHES WITH LOCALIZED 3
INCHES OVER ALREADY SATURATED GROUND. THESE CONDITIONS COULD LEAD TO
RAPID RUN-OFF AND LOCALIZED FLASH FLOODING. WILL MAINTAIN THE FLOOD
WATCH AS IS AREA WISE GIVEN PWATS 1.6" AND THE NUMEROUS TRIGGERS
POSSIBLE. OVERALL HEAVY RAIN THREAT WILL DIMINISH THROUGH SUNDAY
MORNING.
FOR SUNDAY...LINGERING SHOWERS AND SOME ISOLATED THUNDERSTORMS WILL
REMAIN POSSIBLE AS THE BASE OF THE TROUGH PIVOTS ACROSS THE REGION.
WHILE RAIN WILL BE POSSIBLE...HEAVY RAIN DOES NOT APPEAR LIKELY AT
THIS POINT.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
A MUCH NEEDED BREAK FROM THE ACTIVE WET PATTERN FINALLY LOOKS TO
DEVELOP IN THE LONG TERM PERIOD WITH NO MAJOR IMPACT WEATHER
HIGHLIGHTS.
BY MONDAY...GLOBAL MODELS ARE IN AGREEMENT THAT THE TROUGH FROM
SUNDAY WILL LINGER AND POSSIBLY CLOSE OFF IN THE NORTHERN GULF OR
LOWER MISSISSIPPI RIVER VALLEY. SHORTWAVE RIDGING AND DEEPER MID TO
UPPER LEVEL NORTHERLY FLOW MONDAY THROUGH WEDNESDAY SHOULD KEEP MOST
OF THE AREA DRY. THE ONLY SMALL CAVEAT WOULD BE LIMITED MOISTURE
RETURN IN THE LOW-LVLS FROM SE SURFACE WINDS. THERE MAY BE SOME SEA-
BREEZE ACTIVITY THAT COULD MAKE INTO FAR SE COASTAL PRAIRIE ZONES BUT
COVERAGE IS NOT EXPECTED TO BE HIGH. GLOBAL MODELS DIVERGE MID-WEEK
ON STRENGTH OF THE RIDGE OVER TEXAS WITH GFS BEING WEAKER WITH
IMPULSES RIDING THE NORTH EDGE ACROSS THE PANHANDLE WHILE ECMWF IS
MUCH STRONGER WITH LITTLE EVIDENCE OF DISTURBANCES. WILL HAVE TO
MONITOR HOW THIS EVOLVES AND WATCH FOR ANY NW FLOW TSTORM COMPLEX
DEVELOPING ON THE DRYLINE IN FAR W/NW TEXAS AND POSSIBLY SHIFTING
THIS DIRECTION. CONFIDENCE IN THIS POSSIBILITY IS NOT HIGH AT THIS
POINT HOWEVER. GFS ENSEMBLES SUPPORT THE ECMWF AND IT APPEARS A WEAK
TO MODERATE OMEGA BLOCK COULD TAKE FORM MID TO LATE WEEK WITH TEXAS
UNDER THE DRIER RIDGE. THIS WILL ALLOW FOR SWOLLEN AND ELEVATED
RIVER LEVELS TO RECEDE. TEMPERATURES SHOULD BE NEAR NORMAL WITH
READINGS IN THE UPPER 80S/LOW 90S AND LOWS IN THE UPPER 60S/NEAR 70.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 66 83 64 86 66 / 40 20 0 10 -
AUSTIN BERGSTROM INTL AIRPORT 64 82 61 85 64 / 40 20 0 10 0
NEW BRAUNFELS MUNI AIRPORT 67 84 64 87 66 / 50 20 0 - 0
BURNET MUNI AIRPORT 64 80 62 84 65 / 40 10 0 10 0
DEL RIO INTL AIRPORT 66 86 69 89 70 / 50 20 - 10 0
GEORGETOWN MUNI AIRPORT 65 81 62 84 65 / 40 10 0 - -
HONDO MUNI AIRPORT 66 84 65 87 66 / 50 20 - 10 0
SAN MARCOS MUNI AIRPORT 65 82 63 85 65 / 50 20 0 - 0
LA GRANGE - FAYETTE REGIONAL 68 83 63 85 67 / 50 20 - 10 0
SAN ANTONIO INTL AIRPORT 67 84 66 86 68 / 40 20 0 10 0
STINSON MUNI AIRPORT 68 84 67 86 67 / 40 20 0 10 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...
KINNEY...LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...
UVALDE...VAL VERDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
135 PM EDT SAT MAY 30 2015
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL MAINTAIN A VERY WARM AND HUMID AIR
MASS ACROSS THE REGION TODAY INTO SUNDAY. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST LATE IN THE WEEKEND...BEFORE PUSHING
SOUTH OF THE AREA BY MONDAY...RESULTING IN MORE WIDESPREAD SHOWERS
AND THUNDERSTORMS LATER SUNDAY INTO MONDAY AFTERNOON. COOLER
WEATHER UNDER HIGH PRESSURE WILL BUILD IN BY THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 PM EDT SATURDAY...
CONVECTIVE INITIATION AND LATEST RADAR TRENDS SHOWED DEVELOPMENT
OF SCATTERED SHOWERS AND THUNDERSTORMS ALONG THE BLUE RIDGE NORTH
OF ROANOKE AND WEST OF A LINE FROM BUENA VISTA TO BLUEFIELD. HAVE
ADJUSTED PROBABILITY OF PRECIPITATION TO HAVE HIGHEST PERCENTAGES
IN THAT AREA. LITTLE CHANGE NEEDED TO TEMPERATURE FORECAST FOR THE
REST OF THE DAY.
THE LATEST NCAR ENSEMBLE AND HRRR BUT STILL
SHOWED NO MORE THAN CHANCE POPS AT BEST. ELSEWHERE CANT TOTALLY
RULE OUT AT LEAST ISOLATED SHRA/TSRA PER HEATING...DECENT
INSTABILITY...AND HIGH 85H THETA-E WITH BEST CHANCES MOUNTAINS
WHERE AIDED BY OROGRAPHICS ESPCLY BLUE RIDGE.
SHOULD BE ONE OF THE WARMEST DAYS SO FAR THIS SEASON GIVEN A WARM START
AND LESS EXPECTED CLOUDS/TSRA THIS AFTERNOON. AGAIN APPEARS MOS A BIT
COOL AS SEEN OVER THE PAST COUPLE OF DAYS AS THICKNESS SUGGESTS HIGHS
CLOSE TO 90 SE...WITH LOW/MID 80S ELSEWHERE OUTSIDE OF THE HIGHEST
ELEVATIONS.
ANY EVENING CONVECTION MAY LINGER ESPCLY MOUNTAINS AN HOUR OR TWO AFTER
SUNSET BEFORE LOSS OF HEATING AND LACK OF FORCING CAUSE SHOWERS TO FADE
SO WILL KEEP SOME LOW POPS GOING THIS EVENING MAINLY FAR WEST. UPSTREAM
PRE-FRONTAL SHRA/TSRA WILL THEN BE THE MAIN CONCERN OVERNIGHT BUT
APPEARS MUCH OF THIS TOO FAR WEST TO REACH THE REGION BY DAYBREAK
SUNDAY. HOWEVER RETURN OF DEEPER MOISTURE AHEAD OF THE TROUGH/FRONT AS
SEEN IN MODEL PWATS LATE SUPPORTS INCLUDING SOME ISOLATED TO LOW CHANCE
POPS MAINLY WESTERN THIRD LATE. OTHERWISE MAINLY PC WITH ADDED PATCHY
FOG BY MORNING. TEMPS TO REMAIN ON THE WARM/MUGGY SIDE WITH MOST SPOTS
ONLY FALLING INTO THE 60-66 RANGE.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 245 AM EDT SATURDAY
THE MEDIUM RANGE MODELS ARE ALL IN CONSENSUS THAT A SFC COLD FRONT..
ASSOCIATED WITH AN UPPER TROUGH MOVING THROUGH THE EASTERN GREAT
LAKES INTO NEW ENGLAND...MOVES THROUGH OUR FORECAST AREA MONDAY.
HOWEVER...THE MORE NOTICEABLE DRIER AIR AND COOLER TEMPS ARRIVE
MONDAY NIGHT/EARLY TUESDAY ONCE SOUTHERN STREAM ENERGY AND
ASSOCIATED SFC WAVE LIFT EAST.
THE FORECAST AREA WILL REMAIN FIRMLY ENTRENCHED IN THE WARM SECTOR
SUNDAY. WHILE INSTABILITY WILL INCREASE AS HIGHER PWAT AIR
RETURNS...BEST SHEAR AND UPPER LEVEL DYNAMICS REMAIN NORTH AND WEST
OF THE FORECAST AREA THROUGH SUNDAY. WHILE AN ISOLATED SEVERE STORM
IS POSSIBLE...GREATER CONCERN MAY BE WITH LOCALLY HEAVY DOWNPOURS.
WITH THE SLOWER ARRIVAL OF THE FRONT...PUSHED UP TEMPS A COUPLE OF
DEGREES FOR HIGHS...ESPECIALLY IN THE EAST.
KEPT POPS GOING AFTER SUNDOWN SUNDAY WITH FORCING FROM SFC BOUNDARY
MOVING INTO THE AREA. WENT ABOVE GUIDANCE FOR LOWS SUNDAY NIGHT DUE
TO CLOUDS AND SOME MIXING.
PRECIPITATION MAY BE MORE WIDESPREAD MONDAY...ESPECIALLY IN THE
SOUTHERN HALF OF THE FORECAST AREA...AS SFC BOUNDARY SLOWS SOMEWHERE
IN THE EASTERN PORTION OF THE FORECAST AREA DUE TO A SFC WAVE FROM
SOUTHERN STREAM ENERGY DEVELOPING IN NC. EXPECT MORE CLOUD COVER AND
SLIGHTLY COOLER TEMPS ON MONDAY...AS A RESULT...LOWER INSTABILITY.
THE EXCEPTION WOULD BE IN ADVANCE OF THE FRONT...IN THE FAR EASTERN
PORTION OF THE FORECAST AREA WHERE AN ISOLATED SEVERE STORM CANNOT
BE RULED OUT.
DRIER/COOLER AIR FINALLY SURGES INTO THE FORECAST AREA MONDAY NIGHT
AND TUESDAY. LEANED TOWARD THE COOLER GUIDANCE VALUES DURING THIS
PERIOD. WHILE THE SFC BOUNDARY PUSHES SOUTH OF THE FORECAST AREA BY
TUESDAY...850MB THETA-E AXIS LINGERS IN NC AND SOUTHERN VA AND WEAK
OVERRUNNING WILL KEEP THE THREAT FOR SHOWERS FOR THIS AREA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 245 PM EDT FRIDAY...
THE COLD FRONT WILL WASH OUT OVER OR JUST SOUTH OF THE AREA BY
TUESDAY AFTERNOON. AFTER THIS POINT...THE REGION WILL START TO
TRANSITION BACK A SOUTHERLY FLOW PATTERN AS A LOW/TROUGH DEVELOPS
ACROSS THE LOWER MISSISSIPPI RIVER VALLEY...AND HIGH PRESSURE
BECOMES CENTERED AGAIN OFF THE COAST OF THE CAROLINAS. DAYTIME
HEATING ALONG WITH PIECES OF ENERGY EJECTING OFF THE LOWER
MISSISSIPPI VALLEY LOW WILL HELP YIELD INCREASING CHANCE OF SHOWERS
AND STORMS AGAIN BY THURSDAY INTO FRIDAY. TEMPERATURES WILL ALSO
START TO TREND MILDER THURSDAY INTO FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 125 PM EDT SATURDAY...
NWS RADAR SHOWED ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
WERE DEVELOP AT THE START OF THE 18Z TAF PERIOD WEST OF A LINE
FROM BUENA VISTA VIRGINIA TO ROANOKE TO TAZEWELL VIRGINIA. KLWB
HAS THE HIGHEST PROBABILITY OF HAVE THUNDERSTORMS BEFORE 00Z
TODAY BUT MAY ALSO NEED TO ADD TSRA OR VCTS IN FOR THE KROA AND
KBCB TAFS DEPENDING ON SHORT TERM RADAR TRENDS.
ONCE THE SUN SET THE COVERAGE OF SHOWERS AND THUNDERSTORMS WILL
DIMINISH. EXPECT PATCHY MVFR FOG OVERNIGHT. AIRPORT THAT GET RAIN
THIS AFTERNOON ALSO HAVE A BETTER CHANCE OF HAVING FOG AFTER
MIDNIGHT. SIMILAR TO SATURDAY MORNING FOG WILL BE SHALLOW AND WILL
DISSIPATE BY 14Z/10AM SUNDAY.
COLD FRONT WILL TRAIL ACROSS THE OHIO VALLEY ON SUNDAY. THIS WILL
TURN SURFACE AND LOW LEVEL WINDS TO THE SOUTHEAST. NO OTHER UPPER
SUPPORT FOR SHOWERS AND THUNDERSTORMS SUNDAY. ONCE AGAIN STORMS
WILL DEVELOP BETWEEN 16Z-18Z/NOON-2PM BUT PROBABILITY IS NOT HIGH
ENOUGH IN THAT TIME FRAME TO INCLUDE IN THE TAFS.
EXTENDED DISCUSSION...
THE SLOWLY APPROACHING FRONT WILL RESULT IN DEVELOPMENT OF MORE
WIDESPREAD CONVECTION INITIALLY ALONG THE BLUE RIDGE SUNDAY
AFTERNOON AND ACROSS MUCH OF THE WEST LATE IN THE DAY AS THE FRONT
APPROACHES. SOME OF THE CONVECTION MAY SPREAD EAST OF THE BLUE
RIDGE LATER IN THE AFTERNOON SO POTENTIAL FOR A LITTLE MORE IN THE
WAY OF PERIODIC SUB-VFR SUNDAY AFTERNOON/EVENING ESPCLY OVER THE
MOUNTAIN LOCATIONS.
THIS BOUNDARY SHOULD FINALLY SINK SOUTH INTO THE REGION BY MONDAY
RESULTING IN WIDESPREAD CONVECTION ESPCLY BLUE RIDGE EAST...WITH
ADDITIONAL ROUNDS OF SHRA/TSRA INTO AT LEAST MONDAY NIGHT BEFORE
THE BOUNDARY SINKS TO THE SOUTH. THIS SHOULD MAKE FOR MORE
FREQUENT PERIODS OF SUB-VFR FROM SUNDAY NIGHT INTO TUESDAY WITH
LOWER CIGS/VSBY REDUCTIONS DUE TO SHOWERS/STORMS DURING THE
DAY...AND IN FOG OVERNIGHT INTO THE EARLY MORNING HOURS EACH DAY.
LOWER MVFR/IFR CIGS ARE LIKELY BEHIND THE FRONT INTO THURSDAY WITH
EASTERLY FLOW AND WEDGING IN PLACE RESULTING IN MVFR CEILINGS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...JH
SHORT TERM...PH
LONG TERM...DS
AVIATION...AMS/JH/WERT
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1251 PM EDT SAT MAY 30 2015
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL MAINTAIN A VERY WARM AND HUMID AIR
MASS ACROSS THE REGION TODAY INTO SUNDAY. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST LATE IN THE WEEKEND...BEFORE PUSHING
SOUTH OF THE AREA BY MONDAY...RESULTING IN MORE WIDESPREAD SHOWERS
AND THUNDERSTORMS LATER SUNDAY INTO MONDAY AFTERNOON. COOLER
WEATHER UNDER HIGH PRESSURE WILL BUILD IN BY THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 PM EDT SATURDAY...
CONVECTIVE INITIATION AND LATEST RADAR TRENDS SHOWED DEVELOPMENT
OF SCATTERED SHOWERS AND THUNDERSTORMS ALONG THE BLUE RIDGE NORTH
OF ROANOKE AND WEST OF A LINE FROM BUENA VISTA TO BLUEFIELD. HAVE
ADJUSTED PROBABILITY OF PRECIPITATION TO HAVE HIGHEST PERCENTAGES
IN THAT AREA. LITTLE CHANGE NEEDED TO TEMPERATURE FORECAST FOR THE
REST OF THE DAY.
THE LATEST NCAR ENSEMBLE AND HRRR BUT STILL
SHOWED NO MORE THAN CHANCE POPS AT BEST. ELSEWHERE CANT TOTALLY
RULE OUT AT LEAST ISOLATED SHRA/TSRA PER HEATING...DECENT
INSTABILITY...AND HIGH 85H THETA-E WITH BEST CHANCES MOUNTAINS
WHERE AIDED BY OROGRAPHICS ESPCLY BLUE RIDGE.
SHOULD BE ONE OF THE WARMEST DAYS SO FAR THIS SEASON GIVEN A WARM START
AND LESS EXPECTED CLOUDS/TSRA THIS AFTERNOON. AGAIN APPEARS MOS A BIT
COOL AS SEEN OVER THE PAST COUPLE OF DAYS AS THICKNESS SUGGESTS HIGHS
CLOSE TO 90 SE...WITH LOW/MID 80S ELSEWHERE OUTSIDE OF THE HIGHEST
ELEVATIONS.
ANY EVENING CONVECTION MAY LINGER ESPCLY MOUNTAINS AN HOUR OR TWO AFTER
SUNSET BEFORE LOSS OF HEATING AND LACK OF FORCING CAUSE SHOWERS TO FADE
SO WILL KEEP SOME LOW POPS GOING THIS EVENING MAINLY FAR WEST. UPSTREAM
PRE-FRONTAL SHRA/TSRA WILL THEN BE THE MAIN CONCERN OVERNIGHT BUT
APPEARS MUCH OF THIS TOO FAR WEST TO REACH THE REGION BY DAYBREAK
SUNDAY. HOWEVER RETURN OF DEEPER MOISTURE AHEAD OF THE TROUGH/FRONT AS
SEEN IN MODEL PWATS LATE SUPPORTS INCLUDING SOME ISOLATED TO LOW CHANCE
POPS MAINLY WESTERN THIRD LATE. OTHERWISE MAINLY PC WITH ADDED PATCHY
FOG BY MORNING. TEMPS TO REMAIN ON THE WARM/MUGGY SIDE WITH MOST SPOTS
ONLY FALLING INTO THE 60-66 RANGE.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 245 AM EDT SATURDAY
THE MEDIUM RANGE MODELS ARE ALL IN CONSENSUS THAT A SFC COLD FRONT..
ASSOCIATED WITH AN UPPER TROUGH MOVING THROUGH THE EASTERN GREAT
LAKES INTO NEW ENGLAND...MOVES THROUGH OUR FORECAST AREA MONDAY.
HOWEVER...THE MORE NOTICEABLE DRIER AIR AND COOLER TEMPS ARRIVE
MONDAY NIGHT/EARLY TUESDAY ONCE SOUTHERN STREAM ENERGY AND
ASSOCIATED SFC WAVE LIFT EAST.
THE FORECAST AREA WILL REMAIN FIRMLY ENTRENCHED IN THE WARM SECTOR
SUNDAY. WHILE INSTABILITY WILL INCREASE AS HIGHER PWAT AIR
RETURNS...BEST SHEAR AND UPPER LEVEL DYNAMICS REMAIN NORTH AND WEST
OF THE FORECAST AREA THROUGH SUNDAY. WHILE AN ISOLATED SEVERE STORM
IS POSSIBLE...GREATER CONCERN MAY BE WITH LOCALLY HEAVY DOWNPOURS.
WITH THE SLOWER ARRIVAL OF THE FRONT...PUSHED UP TEMPS A COUPLE OF
DEGREES FOR HIGHS...ESPECIALLY IN THE EAST.
KEPT POPS GOING AFTER SUNDOWN SUNDAY WITH FORCING FROM SFC BOUNDARY
MOVING INTO THE AREA. WENT ABOVE GUIDANCE FOR LOWS SUNDAY NIGHT DUE
TO CLOUDS AND SOME MIXING.
PRECIPITATION MAY BE MORE WIDESPREAD MONDAY...ESPECIALLY IN THE
SOUTHERN HALF OF THE FORECAST AREA...AS SFC BOUNDARY SLOWS SOMEWHERE
IN THE EASTERN PORTION OF THE FORECAST AREA DUE TO A SFC WAVE FROM
SOUTHERN STREAM ENERGY DEVELOPING IN NC. EXPECT MORE CLOUD COVER AND
SLIGHTLY COOLER TEMPS ON MONDAY...AS A RESULT...LOWER INSTABILITY.
THE EXCEPTION WOULD BE IN ADVANCE OF THE FRONT...IN THE FAR EASTERN
PORTION OF THE FORECAST AREA WHERE AN ISOLATED SEVERE STORM CANNOT
BE RULED OUT.
DRIER/COOLER AIR FINALLY SURGES INTO THE FORECAST AREA MONDAY NIGHT
AND TUESDAY. LEANED TOWARD THE COOLER GUIDANCE VALUES DURING THIS
PERIOD. WHILE THE SFC BOUNDARY PUSHES SOUTH OF THE FORECAST AREA BY
TUESDAY...850MB THETA-E AXIS LINGERS IN NC AND SOUTHERN VA AND WEAK
OVERRUNNING WILL KEEP THE THREAT FOR SHOWERS FOR THIS AREA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 245 PM EDT FRIDAY...
THE COLD FRONT WILL WASH OUT OVER OR JUST SOUTH OF THE AREA BY
TUESDAY AFTERNOON. AFTER THIS POINT...THE REGION WILL START TO
TRANSITION BACK A SOUTHERLY FLOW PATTERN AS A LOW/TROUGH DEVELOPS
ACROSS THE LOWER MISSISSIPPI RIVER VALLEY...AND HIGH PRESSURE
BECOMES CENTERED AGAIN OFF THE COAST OF THE CAROLINAS. DAYTIME
HEATING ALONG WITH PIECES OF ENERGY EJECTING OFF THE LOWER
MISSISSIPPI VALLEY LOW WILL HELP YIELD INCREASING CHANCE OF SHOWERS
AND STORMS AGAIN BY THURSDAY INTO FRIDAY. TEMPERATURES WILL ALSO
START TO TREND MILDER THURSDAY INTO FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 640 AM EDT SATURDAY...
FOG REMAINS PATCHY ACROSS THE REGION EARLY THIS MORNING BUT DENSE
IN SPOTS WITH IFR/LIFR AT KBCB/KLWB AND AREAS OF MVFR AROUND KROA.
THIS ALSO RESULTING IN SOME LOWER STRATUS AS WELL WITH MOSTLY MID
DECK ELSEWHERE OVER THE MOUNTAINS WHERE STILL SEEING ISOLATED
SHOWERS NW OF KLWB. EXPECT FOG/LOW CLOUDS TO QUICKLY ERODE WITH
HEATING AROUND 13Z/9AM...FOLLOWED BY DEVELOPMENT OF VFR 4-6K FT
CU FIELDS BY MIDDAY INTO THIS AFTERNOON. HOWEVER...UNLIKE
FRIDAY...EXPECT SOME SUBSIDENCE NUDGING IN FROM THE SOUTHEAST SUCH
THAT ANY DIURNAL REDEVELOPMENT OF SHOWERS/STORMS BY LATE
MORNING/EARLY AFTERNOON EXPECTED TO BE LESS IN OVERALL COVERAGE
AND MAINLY CONFINED TO SOUTHEAST WEST VIRGINIA. THEREFORE...VCTS
KEPT AT KBLF AND KLWB AROUND 17Z/1PM...BUT NOT AT THE REMAINING
AVIATION FORECAST POINTS FOR NOW GIVEN MORE EXPECTED ISOLATED
NATURE TO ANY CONVECTION.
ANY SHOWERS/STORMS SHOULD AGAIN FADE WITH LOSS OF HEATING THIS
EVENING BUT WITH DEEPER MOISTURE RETURNING OVERNIGHT AHEAD OF THE
FRONT TO THE WEST COULD SEE A BIT MORE ISOLATED COVERAGE LATER
TONIGHT. HOWEVER NOT ENOUGH TO INCLUDE MENTION IN THE TAFS WITH
MORE IFR/LIFR FOG POSSIBLE AT KLWB/KBCB BY DAYBREAK SUNDAY WITH
PATCHY BUT BRIEF MVFR ELSEWHERE ACROSS THE VALLEYS.
EXTENDED DISCUSSION...
ON SUNDAY...A MOIST UNSTABLE AIR MASS WILL REMAIN IN PLACE ACROSS
THE REGION WITH BETTER SW FLOW AHEAD OF A COLD FRONT NEARING THE
MOUNTAINS BY SUNDAY EVENING. THIS WILL RESULT IN DEVELOPMENT OF
MORE WIDESPREAD CONVECTION INITIALLY ALONG THE BLUE RIDGE SUNDAY
AFTERNOON AND ACROSS MUCH OF THE WEST LATE IN THE DAY AS THE FRONT
APPROACHES. SOME OF THE CONVECTION MAY SPREAD EAST OF THE BLUE
RIDGE LATER IN THE AFTERNOON SO POTENTIAL FOR A LITTLE MORE IN THE
WAY OF PERIODIC SUB-VFR SUNDAY AFTERNOON/EVENING ESPCLY OVER THE
MOUNTAIN LOCATIONS.
A FRONTAL SYSTEM WILL CONTINUE TO SLOWLY APPROACH THE AREA FROM
THE NORTHWEST SUNDAY NIGHT. THIS BOUNDARY SHOULD FINALLY SINK
SOUTH INTO THE REGION BY MONDAY RESULTING IN WIDESPREAD
CONVECTION ESPCLY BLUE RIDGE EAST...WITH ADDITIONAL ROUNDS OF
SHRA/TSRA INTO AT LEAST MONDAY NIGHT BEFORE THE BOUNDARY SINKS TO
THE SOUTH. THIS SHOULD MAKE FOR MORE FREQUENT PERIODS OF SUB- VFR
FROM SUNDAY NIGHT INTO TUESDAY WITH LOWER CIGS/VSBY REDUCTIONS
DUE TO SHOWERS/STORMS DURING THE DAY...AND IN FOG OVERNIGHT INTO
THE EARLY MORNING HOURS EACH DAY. LOWER MVFR/IFR CIGS ARE LIKELY
BEHIND THE FRONT INTO WEDNESDAY WITH EASTERLY FLOW AND WEDGING IN
PLACE RESULTING IN MVFR CEILINGS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...JH
SHORT TERM...PH
LONG TERM...DS
AVIATION...AMS/JH/WERT
AREA FORECAST DISCUSSION
NWS PORTLAND
348 PM PDT SAT MAY 30 2015
.SYNOPSIS...THE UPPER FLOW WILL TURN MORE SOUTHERLY LATER TONIGHT
AND SUNDAY AHEAD OF THE NEXT LOW OFF THE COAST...SHARPENING THE
UPPER RIDGE... RESTRICTING THE MARINE LAYER MORE TO THE COAST
AGAIN...AND ALLOWING INLAND TEMPS TO WARM. AS THE LOW MOVES ONSHORE
SUNDAY NIGHT AND MONDAY...LOOK FOR MORE CLOUDS...AND CHANCE OF
SHOWERS AND POSSIBLY A FEW THUNDERSTORMS EVEN AT NIGHT...AS WELL AS
SUBSTANTIAL COOLING. SOME STORMS ON SUNDAY MAY BECOME STRONG. THE
COOLER SHOWERY PATTERN WILL CONTINUE THROUGH MID WEEK OR SO...THEN
SOME DRYING AND A BIT OF WARMING IS POSSIBLE LATE NEXT WEEK.
&&
.SHORT TERM...TONIGHT THROUGH TUESDAY...BROAD UPPER RIDGE WILL
CONTINUE TO SHIFT EAST BECOMING CENTERED OVER THE ROCKIES BY MIDDAY
SUNDAY. THIS WILL OPEN THE DOOR FOR MODESTLY DEEP TROUGH TO DIG
OFFSHORE AND THEN SLIDE OVER THE REGION AND BE CENTERED JUST
OFFSHORE BY MONDAY EVENING. WILL PROBABLY SEE THE MOST INTERESTING
WEATHER DURING THE TRANSITION PERIOD SUNDAY AFTERNOON THROUGH MONDAY
MORNING AS A MODEST SHORTWAVE ROTATES AROUND THE BASE OF THE TROUGH
AND TAKES ON A NEGATIVE TILT ORIENTATION.
SUNDAY WILL SEE SURFACE TEMPERATURES REBOUND 4 TO 8 DEGREES WHILE
TEMPERATURES ALOFT COOL OFF. 500 MB FLOW ALOFT WILL ALSO BECOME MORE
DIFFLUENT WITH TIME. THIS SETS UP A FAIRLY GOOD CONVECTIVE SCENARIO
AND ESPECIALLY FOR THE CASCADES IN THE AFTERNOON AND EARLY EVENING.
MAY ALSO SEE SOME SHOWERS AND THUNDERSTORMS FOR THE SOUTH VALLEY
DURING THE EVENING. ANY STORMS WHICH DO FORM OVER CASCADES WILL HAVE
SOME GOOD BULK SHEAR OF 35 TO 45 KTS PLUS A FAIR AMOUNT OF CAPE
AVAILABLE THROUGH THE HAIL GROWTH ZONE. MOST OF THE SHEAR APPEARS TO
BE FROM INCREASING SPEED ALOFT AND NOT SO MUCH ROTATIONAL SHEAR.
STORM MOTIONS ARE FROM SOUTHWEST TO NORTHEAST AND FAIRLY SLOW AT NO
MORE THAN 10 KTS. PW VALUES ARE AT 0.85 INCHES AND HAVE SOME
MODERATE RAIN CAPABILITY AS WELL. THEREFORE...THE MAIN CONCERNS FROM
THE STORMS WILL BE POTENTIAL FOR MODERATE RAINS...0.50 INCH HAIL
WITH A NON-TRIVIAL CHANCE FOR LARGER HAIL...AND SOME POTENTIAL FOR
MARGINALLY SEVERE WINDS. AS WE GET CLOSER TO THE EVENING HOURS...MAY
SEE CONVECTION BEGIN INITIATING AS FAR WEST AS THE EUGENE AREA BUT
THE DYNAMIC SUPPORT IS FAR WEAKER OVER THERE SO DO NOT ANTICIPATE
NEAR THE STRENGTH POTENTIAL FROM THOSE STORMS SHOULD ANY DEVELOP.
AS THE INITIAL ROUND OF STORMS WEAKEN SUNDAY EVENING...AN UPPER
LEVEL TROPOPAUSE FOLD DIPPING DOWN TO 500 MB APPROACHES THE CENTRAL
COAST FROM THE SOUTHWEST. AT THIS POINT THE BEST DYNAMICS WILL BE TO
THE EAST OF THE CASCADE CREST BUT STILL HAVE SOME MINOR POTENTIAL
FOR THAT FOLD TO ACT AS A TRIGGER FOR SOME ELEVATED NOCTURNAL
CONVECTION. WE HAD THE CASCADES COVERED WITH CHANCE WORDING ALREADY
BUT THESE EVENTS COMMONLY INITIATE ABOUT 75 TO 100 MILES FURTHER
WEST THAN MODEL DATA WOULD INDICATE. HAVE THEREFORE PUSHED THE
THUNDERSTORM COVERAGE FURTHER WEST OVERNIGHT SUNDAY NIGHT AND EARLY
MONDAY MORNING BY ADDING A SLIGHT CHANCE THUNDERSTORM MENTION. THERE
MAY AN OCCASIONAL HANDFUL OF CLOUD TO GROUND STRIKES BUT THE LACK
OF DYNAMICS WILL RESULT IN JUST A PRIMARY IN CLOUD SHOW...AGAIN IF
ANY DO OCCUR.
THE SHORTWAVE TROUGH AXIS ASSOCIATED WITH THE TROPOPAUSE FOLD LIFTS NORTH
ACROSS THE AREA DURING MONDAY MORNING AND SHOULD LARGELY END THE
SIGNIFICANT THREAT FOR THUNDERSTORMS. THERE WILL BE PLENTY OF
TRAILING SHOWERS THROUGH TUESDAY AS THE PARENT UPPER TROUGH SETTLES
IN OFFSHORE AND BEGINS FILLING AND SLOWLY DRIFTING NORTH.
TEMPERATURES ALOFT WILL BE GRADUALLY WARNING AT THIS POINT AND
LIKELY RESULT IN RAIN WITH THE OCCASIONAL EMBEDDED SMALL HAIL
SHAFT. /JBONK
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...THE AFOREMENTIONED
UPPER TROUGH WILL CONTINUE TO DRIFT NORTH TUESDAY NIGHT AND SHOWERS
WILL DIMINISH. WEDNESDAY LARGELY LOOKS DRY AT THIS POINT WITH THE
WASHINGTON ZONES POSSIBLY GETTING SOME SCATTERED SHOWERS EARLY. THE
CASCADES STILL HAVE AN OUTSIDE CHANCE AT SOME LIGHT SHOWERS THURSDAY
AS AN UPPER RIDGE REESTABLISHES OFFSHORE WITH RISING HEIGHTS. FRIDAY
AND SATURDAY APPEAR DRY FOR NOW AS THE RIDGE AXIS EXTENDS NORTHWARD
AND BEGINS TO TAKE A POSITIVE TILT OVER THE PACNW FOR DRY WEATHER
HEADING INTO THE WEEKEND. /JBONK
&&
.AVIATION...MARINE STRATUS WAS QUICK TO RECEDE OFF THE COAST THIS
AFTERNOON...ALLOWING WIDESPREAD VFR CONDITIONS TO PREVAIL. EXPECT
MVFR STRATUS TO RETURN BY 23Z SAT-02Z SUN ALONG THE COAST. HIGH
CLOUDS CONTINUE ACROSS THE REGION. MVFR COASTAL STRATUS WILL
LOWER ALONG THE COAST AGAIN TO 1500 FT TONIGHT...AND TRY TO MOVE
INLAND OVERNIGHT BUT MAY NOT REACH AS FAR INLAND EARLY SUN
MORNING.
KPDX AND APPROACHES...VFR NEXT 24 HRS WITH INCREASING MID AND HIGH
CLOUDS. /27
&&
.MARINE...QUIET CONDITIONS PREVAIL OVER THE COASTAL WATERS THROUGH
MUCH OF NEXT WEEK. NW TO N WINDS GENERALLY 15 KT OR LESS...WITH
AFTERNOON AND EVENING GUSTS UP TO 20 KT AT TIMES.
SEAS PRIMARILY 5 FT OR LESS THROUGH NEXT WEEK. SPECTRAL ANALYSIS
SUGGESTS SEVERAL 2 OR 3 FT SWELL SETS THROUGH EARLY NEXT
WEEK...ANY OF WHICH COULD BE THE DOMINANT FEATURE. EXPECT MAINLY
WIND-WAVE DOMINATED CONDITIONS THROUGH THE WEEKEND...WITH A
SECONDARY LONGER-PERIOD SW SWELL. WEISHAAR/27
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
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.
[top]
Area Forecast Discussion
National Weather Service Spokane WA
308 PM PDT SAT MAY 30 2015
.SYNOPSIS...
Strong thunderstorms will be possible in the Idaho Panhandle and
in the Northeast Mountains early this evening with large hail,
gusty winds and heavy rains possible. Thunderstorm chances will
lessen on Sunday and are expected to be more confined to a small
portion of southeast Washington and north central Idaho.
Meanwhile most locations will see very warm temperatures with
highs in the 80s through the weekend. Thunderstorm chances will
increase markedly on Monday into Tuesday as a strong upper level
trough moves in from the south. Some of the storms on Monday could
be strong. Unsettled and cooler weather will persist into the
remainder of the work week with a threat of showers and
thunderstorms each day.
&&
.DISCUSSION...
Rest of This Afternoon and Tonight: Short term models seem to
agree on the best shower and thunderstorm activity to continue
through the afternoon and then begin to tapper off quickly after
about 5pm. Scattered showers and thunderstorms will
continue...mainly impacting eastern WA and north ID. The best
chance of strong storms will be across NE WA and north ID. All
storms will produce torrential rains and frequent lightning.
However the stronger storms will also see gusty winds and large
hail. After 5 pm showers and thunderstorms will begin to decrease,
and even more so during the overnight hours. Drier air is moving
through the Kittitas Valley and will continue to push east into
portions of the Columbia Basin. This will hinder showers and
thunderstorms from developing. The Cascades will also see a break
today/tonight. Activity will decrease overnight but some high
clouds will begin to stream in from the south. /Nisbet
Sunday and Monday...The strong upper level low currently over
central British Columbia will shift into Alberta on Sunday with
a shortwave ridge temporarily setting up over the area. With the
passage of the low...most of the moisture and instability will be
shunted into NE Oregon and central Idaho with the extreme
southeast portion of our forecast area...ie the Blues, Lewiston
Area, and Camas Prairie remaining subject to a continued chance of
diurnal convection. Nothing looks too impressive on Sunday with
little if any upper level forcing combined with weak upper level
subsidence associated with the shortwave trough. Meanwhile temperatures
will remain unseasonably warm with valley highs generally in the 80s
to lower 90s. The lofty precipitable water values of late will
take a temporary reprieve with most dewpoints falling into the mid
30s and 40s which is significantly drier than the 50s of the past
couple days.
...STRONG to SEVERE Storms looking more likely for Monday...
By late Sunday night or Monday the pattern changes significantly
as a deep offshore trough...currently off the California
Coast...heads into SW Oregon in the morning and then up the WA/OR
border by afternoon. The trough will take on a negative
orientation ( a classic orientation for severe weather over the
Inland NW) as it heads northward into our area resulting in good
upper level difluent flow combined with significant atmospheric
destabilization. Its interesting to note that as early as 5am
Monday...some of the instability parameters are quite impressive
along the Oregon/Washington border. The High Level Total Totals
suggest a good potential for elevated nocturnal convection moving
northward from Oregon and into the southern portions of Washington
and NC Idaho. Even more impressive are surface CAPES around 700
j/kg in the Blues with MUCAPES approaching 2000 j/kg. These are
impressive values for this region during the peak of the afternoon
heating but this early in the morning would be something rather
unusual and this could foretell the weather for the remainder of
the day. Model agreement is growing that this instability will
continue to spread northward through the day ahead of the incoming
trough. The trough will bring good lifting potential to much of
the area while the potential instability will likely allow
numerous thunderstorms to form. MUCAPES will approach or exceed
2000 over much of the region by afternoon. Meanwhile the shear
associated with the incoming trough wont be great...but with 0-6
km values of 20-30 kts over portions of the forecast area it is
certainly sufficient for strong/isolated severe development.
Precipitable water values will also near an inch...which is even
heavier than we`ve seen over the past several days and given weak
steering flow, especially near the Cascades we will need to be
concerned with more flash flooding potential as well. It would not
be surprising if Monday turns out to be the most active day of the
past several days. fx
Monday night through Saturday...the upper level low will take up
residence over the Inland Northwest through at least the midweek
period. Showers will be widespread Monday night into Tuesday as the
low pressure center is directly over the forecast area. Scattered
thunderstorms will be possible during peak daytime heating each day,
with the higher elevations more favored for development. Shower
coverage will diminish as the low drifts off to the southeast toward
the end of the work week with mostly dry conditions expected for
Friday and Saturday. Cool temperatures on Tuesday will start to
trend a bit warmer as shower coverage lessens. /Kelch
&&
.AVIATION...18Z TAFS: A very unstable atmosphere will remain fixed
over the eastern third of Washington and the Idaho Panhandle
through at least 00z. This will lead to a chance of thunderstorms
by this afternoon...with the best chances likely impacting GEG SFF
and COE with smaller chances at PUW and LWS. We did not put
prevailing thunder in the forecasts since the HRRR has
consistently kept the bulk of the thunder north and east of GEG-
COE as well as east of PUW-LWS. Nonetheless not confident that
will pan out as the atmosphere is quite ripe for convection with
clearing skies moving in from the west-southwest which should tap
into this instability. Thunderstorms will be capable of small
hail, gusty outflow winds, frequent lightning strikes and
torrential rainfall. Drier air across the Cascades will quickly
eradicate the thunder chances between 00z-02z with the last
remnants hanging on over the northern Panhandle. Remainder of the
forecast should see dry weather with VFR conditions.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 56 82 59 77 52 70 / 10 10 10 70 70 60
Coeur d`Alene 55 81 57 78 52 68 / 30 10 10 70 70 60
Pullman 54 80 56 74 49 66 / 10 10 20 70 60 60
Lewiston 62 88 62 82 56 73 / 20 20 20 80 70 60
Colville 53 84 56 81 54 73 / 20 10 10 70 80 80
Sandpoint 52 80 54 77 51 68 / 60 10 10 70 80 80
Kellogg 53 79 55 75 49 66 / 50 10 10 80 80 80
Moses Lake 56 87 61 83 55 75 / 0 0 0 60 50 50
Wenatchee 60 86 62 80 56 74 / 0 0 10 60 70 70
Omak 52 85 56 81 53 74 / 10 0 0 70 80 80
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1213 PM CDT SAT MAY 30 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 255 AM CDT SAT MAY 30 2015
UPPER LEVEL SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT MAKING STEADY
ALBEIT SOMEWHAT SLOW PROGRESS EAST/SOUTHEAST ACROSS THE REGION EARLY
THIS MORNING. SHOWERS WERE WIDESPREAD AHEAD OF IT...WITH A LINE OF
CONVECTION RIDING ALONG THE FRONT.
THE FRONT SINKS ACROSS ILL BY LATE MORNING BUT THE TROUGH AXIS ISN/T
SLATED TO CLEAR THE FORECAST AREA TIL THIS EVENING. NAM POINTS TO
SOME ELEVATED FRONTOGENETIC FORCING ACROSS NORTHEAST IA/SOUTHWEST WI
THROUGH THE BETTER PART OF THE DAY...BUT MINIMAL IF ANY INSTABILITY
AND NON-IMPRESSIVE LAPSE RATES. THE NAM WOULD HANG ONTO SOME RAIN
CHANCES ACROSS THE FAR SOUTH INTO THE AFTERNOON...BUT MOST MESO
MODELS WANT TO CLEAR IT BY 18Z. GOING TO SIDE THE FORECAST TOWARD
THESE MORE PROGRESSIVE SOLUTIONS.
HIGH PRESSURE BUILDS IN LATER TODAY AND HANGS AROUND THE GREAT LAKES
THROUGH MONDAY. GFS/NAM/ECMWF ALL SUGGEST THE HIGH WILL SERVE TO
BOUNCE ANY POTENTIAL SHORTWAVES SOUTH/NORTH OF THE FORECAST AREA
DURING THIS TIME...KEEPING THE AREA DRY. WILL CONTINUE THIS TREND.
TEMPERATURES ARE GOING TO TAKE A TUMBLE FOR THE NEXT FEW DAYS...WITH
850 BM TEMPS FALLING FROM NEAR 12C LAST NIGHT...TO 4 C BY 00Z MON.
HIGHS WILL MOSTLY BE IN THE 60S THROUGH MONDAY. IN ADDITION...WITH
CLEARING SKIES TONIGHT...RADIATIONAL COOLING COULD RESULT IN SOME
MID 30 LOWS FOR PARTS OF CENTRAL/NORTHERN WI. PATCHY/AREAS FROST IS
POSSIBLE. WINDS COULD STAY ABOVE 5 KTS THOUGH...WHICH LIMITS
CONFIDENCE IN A WIDESPREAD EVENT. PER COORDINATION WITH SURROUNDING
OFFICES...WILL ISSUE FROST ADV FOR TAYLOR COUNTY IN NORTH-CENTRAL
WI. IF WIND SPEEDS LOOK LOWER...THE ADV COULD BE EXPANDED INTO PARTS
OF CENTRAL WISCONSIN WHERE COLD AIR DRAINAGE IS COMMON.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT MAY 30 2015
EXTENDED FORECAST HINGES ON THE STRENGTH OF THE LONG WAVE RIDGE
BUILDING ANTICIPATED FOR MUCH OF THE CENTRAL U.S...WILL IT BE ENOUGH
TO HOLD AT BAY THE VARIOUS PERTURBATIONS A WEST COAST TROUGH WILL
SEND AT US.
MODELS ALREADY AT ODDS WITHIN AND BETWEEN EACH OTHER...AND EXPECT
THE DIFFERENCES TO PERSIST FOR AT LEAST THE NEXT COUPLE DAYS. THIS
LOWERS FORECAST CONFIDENCE IN THE DRY-NOT DRY QUESTION. WILL HAVE TO
LEAN ON CONSENSUS AS A RESULT...WHICH PAINTS A LOT OF SMALL
POPS...ESPECIALLY WEST AND NORTH.
AS IT STANDS NOW...THE GFS FAVORS THE DRIER SOLUTION...USING THE
RIDGE TO KEEP/SHUNT PCPN CHANCES WEST/NORTH. THIS IS ESPECIALLY
EVIDENT ON WED WHERE THE EC/GEM TAKES A SHORTWAVE THEY ALL FORECAST
INTO THE UPPER MISSISSIPPI RIVER VALLEY...BRINGING THE THREAT FOR
SHOWERS/STORMS. THE EC THEN STAYS THE WET MODEL WITH ANOTHER
SHORTWAVE WORKING IN CONCERT WITH A SFC FRONT TO CONTINUE THE RAIN
THREAT INTO FRIDAY MORNING. THE GFS WOULD FINALLY BREAK INTO THE
RIDGE ON FRIDAY...CONTINUING SOME SMALL PCPN CHANCES INTO SAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1213 PM CDT SAT MAY 30 2015
MVFR DECK REMAINS OVER THE AREA IN THE WAKE OF THE COLD FRONT THAT
WENT THROUGH OVERNIGHT. THE BACK EDGE OF THE CLOUDS ARE SLOWLY
WORKING EAST ACROSS MINNESOTA...BUT STILL EXPECT IT WILL TAKE MOST
OF THE AFTERNOON BEFORE THESE CLOUDS WILL START TO SCATTER OUT.
BASED ON THE 30.15Z RAP SOUNDINGS...THE CLEARING SHOULD OCCUR LATE
THIS AFTERNOON AT KRST AND EARLY THIS EVENING AT KLSE. WITH THE
RECENT RAINS...CONCERNED ABOUT FOG POTENTIAL OVERNIGHT WITH ALL
THE LOW LEVEL MOISTURE AND THE CLEARING SKIES. HOWEVER...IT LOOKS
LIKE THE WINDS WILL REMAIN BETWEEN 5 AND 10 KNOTS OUT OF THE
NORTHEAST AS HIGH PRESSURE SLOWLY BUILDS IN FROM CANADA. DEW
POINTS ARE IN THE 30S ACROSS NORTHERN MINNESOTA AND WISCONSIN AND
THE NORTHEAST WINDS SHOULD ADVECT THIS DRIER AIR IN HELPING TO
MITIGATE THE FOG THREAT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM 3 AM TO 8 AM CDT SUNDAY FOR WIZ017.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04