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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KLWX 201907
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
307 PM EDT MON MAY 20 2013

.SYNOPSIS...
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HIGH PRESSURE OVER THE ATLANTIC WILL PROVIDE A SOUTHERLY FLOW FOR
TUESDAY AND WEDNESDAY...BRINGING WARM AND HUMID CONDITIONS.
MEANWHILE...AND UPPER LEVEL DISTURBANCE WILL CROSS THE REGION. A
COLD FRONT WILL PASS THROUGH THE AREA THURSDAY AFTERNOON AND
EVENING. COOLER CONDITIONS WILL RETURN FOR NEXT WEEKEND.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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CWFA WITHIN WARM SECTOR TAFTN...BUT LOTSA CLDCVR HAS HELD TEMPS
DOWN...WHICH IN TURN HAS LIMITED AMT IN INSTBY GENERATED. CUTOFF
H5 TROF AXIS UNDER L/WV RDGG HAS ASSISTED IN FOCUSING SHRA/TSRA
ACTIVITY ACRS WVA/WRN VA/CENTRL NC. SINCE THESE STORMS ARE W/IN A
RDG AXIS...FWD MOTION HAS BEEN SLOW...AND MUCH OF THIS ACTIVITY
LKLY WONT REACH CWFA E OF THE SHEN VLY. GREATER INSTBY ALSO CAN BE
FOUND IN SERN VA/ERN NC DUE TO MORE AMPLE HEATING...AND SOME OF
THESE STORMS WL APPROACH SRN MD AND THE NRN NECK OF VA. POPS HIEST
IN THESE TWO AREAS. AM HANGING ONTO CHC POPS ELSW TIL ABT SUNSET.
PWAT ALMOST UP TO 1.5 INCHES...SO HVY RAIN SHUD BE THE BIGGEST
THREAT.

ONCE DAYTIME HEATING WANES...THINK SHRA/TSRA CVRG SHUD DIMINISH.
AM RUNNING WITH A DRY FCST OVNGT. ITS PSBL THAT THERE MAY BE A
STRAY STORM OR TWO...BUT CANNOT PINPOINT WHERE...AND WUD RATHER
NOT BLANKET SMALL POPS OVER A LARGE AREA. INSTEAD...THE NEARLY
SATD LLVLS SHUD LEAD TO MORE LOW CLDS/FOG FOR THE OVNGT HRS.
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&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
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MID-ATLANTIC WILL RESIDE IN A WARM SECTOR DURING THE MID-WEEK. THIS
WILL ALLOW FOR A WARM UP TUESDAY THROUGH WEDNESDAY...WITH MAXIMA IN
THE MID 80S. IF THERE IS MORE SUNSHINE...THEN MAXIMA COULD EVEN
REACH UPPER 80S IN SOME LOCATIONS.

TUESDAY MORNING MAY START OFF WITH SOME FOG/STRATUS...BUT CLOUDS
SHOULD BREAK FOR SOME SUNSHINE DURING THE AFTERNOON. GREATER
INSTBY IN PLACE AND H5 TROF AXIS SHUD STILL BE LINGERING...MUCH
LIKE SSIDE VA/NC TAFTN. PLUS...THERE WL BE TRRN BASED
CIRCULATIONS AND DIURNAL HEATING BNDRYS. AM THEREFORE
UNCOMFORTABLE WITH A DRY FCST...AND HV ADDED CHC POPS CENTERED
UPON TIME OF PEAK HTG TUE AFTN. AM TAKING THAT ROUND EWD IN THE
EVNG INVOF H5 AXIS.

THE MID LVL RDG AXIS BREAKS DOWN WED WHICH WL PROVIDE ITS OWN TSRA
SUPPORT. WED AFTN POPS SEEM ADEQUATE IN THE 30-40 PCT RANGE...BUT
HV INCREASE EVNG CVRG AS HGTS FALL. NWRN CORNER OF CWFA TOUCHING
SPC DAY 3 SLGT RISK...AND ISOL SVR CRVG TO APPROX THE BLURDG IN
CONJUNCTION WITH THIS THREAT.
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&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
SLIGHT HEIGHT FALLS ARE FORECAST TOWARD THE END OF THE WEEK AS AN
UPPER TROUGH APPROACHES...IN TANDEM WITH A COLD FRONT. THERE IS SOME
QUESTION REGARDING TIMING OF THE FROPA...LATEST GUIDANCE SUGGESTING
LATE THURSDAY INTO EARLY FRIDAY. DUE TO UNCERTAINTY HAVE CHANCE POPS
IN THE THURSDAY THROUGH FRIDAY TIME FRAME...AND WE CAN FINE TUNE THE
TIMING AS WE GET CLOSER.

THERE IS GOOD AGREEMENT THAT THE FRONT WILL HAVE MOVED THROUGH THE
AREA BY THE WEEKEND...FAVORING A COOLER/DRIER AIR MASS. FORECAST
REFLECTS MOSTLY CLEAR SKIES AND TEMPERATURES NEAR CLIMATOLOGY.
&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
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CIGS HV LIFTED...AND VFR CONDS PREVAIL AT ALL SITES XCPT MTN.
TSRA/SHRA CHCS THRU SUNSET SLIM...BUT NONZERO. UNLKLY THAT A CELL
WL AFFECT AN AIRFIELD...BUT CHO WL BE NEAREST AIRPORT.

EXPECT FOG/STRATUS EARLY TUESDAY AS LOW LEVEL MOISTURE REMAINS.
ONCE THIS MSTR BURNS OFF...VFR EXPECTED TO PREVAIL THE BALANCE OF
TUESDAY. CHANCE OF THUNDERSTORMS RETURNS IN THE AFTN...BUT CVRG
ISSUES REDUCE CONFIDENCE IF AIRFIELDS WL BE IMPACTED. A REPEAT
PERFORMANCE POSSIBLE WED...AND AGAIN THU. GREATEST CVRG ASSOCD
WITH CFP LT THU.
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&&

.MARINE...
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SLY WNDS TAFTN...BUT AOB 10 KT. THERE MAY BE A FEW SHRA/TSRA...
SPCLY IN THE MID BAY/LWR PTMC WHICH WUD PRODUCE LCLLY HIER WNDS.

SLY WINDS ARE EXPECTED TUE-WED UNTIL A COLD FRONT MOVES THROUGH
THU SWITCHING WINDS TO THE NORTHWEST. THERES A DAILY TSRA RISK...
SPCLY IN THE AFTN/EVE.

SOUTHERLY CHANNELLING UP THE BAY COULD BRING MARGINAL SCA
CONDITIONS...PARTICULARLY DURING THE LATE AFTERNOON/EVENINGS.
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&&

.TIDES/COASTAL FLOODING...
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TIDAL ANOMALIES REMAIN NEAR NORMAL. WILL HAVE TO WATCH SOUTHERLY
FLOW DURING THE MID-WEEK AS IT MAY SUPPORT AN INCREASE IN
DEPARTURES AGAIN.
-- End Changed Discussion --
&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$