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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
901 PM EDT WED MAY 6 2015

.SYNOPSIS...
A WEAK FRONT OVER PENNSYLVANIA WILL DISSIPATE OVERNIGHT. HIGH
PRESSURE WILL BUILD OVER THE NORTHERN MID-ATLANTIC THURSDAY. LOW
PRESSURE OFF THE CAROLINA COAST FRIDAY WILL GRADUALLY ERODE THIS
WEEKEND. A COLD FRONT LOOKS TO MOVE INTO THE REGION TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
TWO CLUSTERS OF SHOWERS AND THUNDERSTORMS...ONE OVER THE EASTERN
WEST VIRGINIA PANHANDLE AND NEAR THE CITY OF WINCHESTER AND THE
OTHER OVER THE VIRGINIA PIEDMONT...ARE WEAKENING AS THEY DROP
SOUTHWARD THE REMAINDER OF THIS EVENING. EARLIER...THIS ACTIVITY
WAS PRODUCING FREQUENT LIGHTNING...HEAVY DOWNPOURS AND EVEN SOME
LARGE HAIL. NOW...THIS ACTIVITY HOLDS NOT MUCH MORE THAN A QUICK
DOWNPOUR OR A WIND GUST OVER 35 MPH. ONE THING TO NOTE IS TO BE
CAUTIOUS ABOUT DRIVING THIS EVENING IN CASE YOU COME ACROSS SOME
PONDING OF WATER ON ROADWAYS DUE TO THE DOWNPOURS OR IF YOU ARE
OUTDOORS TO BE LEARY OF AN OCCASIONAL LIGHTNING STRIKE WITH THE
COLLAPSING THUNDERSTORMS.

ANY OTHER RESIDUAL SHOWERS SHOULD DISSIPATE WITHIN THE HOUR AND
ARE FEW AND FAR BETWEEN EACH OTHER. NO BIG ISSUES EXPECTED
OVERNIGHT. REGARDING RECENT RAINFALL FROM EARLIER ACTIVITY...SOME
PLACES MAY ENCOUNTER PATCHY FOG THAT COULD REDUCE VISIBILITY
QUICKLY BUT BRIEFLY. LOWS MAINLY IN THE 55-60 RANGE
OVERNIGHT..SLTLY WARMER IN THE CITIES AND COOLER IN THE HIGHLANDS.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
FNT IS XPCTD TO DISSIPATE OVR THE MID ATLC THU THEN WK INDUCED
HIGH PRES OVR THE AREA. PERHAPS SRN PART OF THE FCST AREA WL SEE
SOME HIGH CLDS AS A RESULT OF THE LOW PRES AREA OFF THE GA/SC
CST. HIGHS GNRLY ARND 80.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE PERIOD FROM THURSDAY NIGHT THROUGH FRIDAY NIGHT MAY BE AMONG THE 
MOST TRANQUIL OF THE PERIOD...YET STILL FEELING A LITTLE MORE LIKE 
SUMMER THAN SPRING. MID/UPPER LEVEL RIDGE AXIS WILL BE CENTERED 
OVERHEAD WITH SFC HIGH PRESSURE OFFSHORE. COASTAL LOW PRESSURE WILL 
BE TRAPPED UNDER THE RIDGE JUST OFF THE CAROLINA COAST. ITS EFFECTS 
ON THE LOCAL AREA SHOULD BE MINIMAL THROUGH THIS TIME 
PERIOD...ALTHOUGH A SURGE OF HIGHER PWATS BEGINS TO MOVE NORTH LATE 
FRIDAY. THERE WON/T BE MUCH FORCING TO TAP INTO IT THOUGH...AND IT 
APPEARS ANY PRECIP WILL STAY SOUTH OF THE CWA. OTHERWISE EXPECT ONLY 
ISOLATED DIURNAL CONVECTION TIED TO THE TERRAIN...AS LOCATIONS EAST 
OF THE ALLEGHENIES WILL LIKELY BE CAPPED.

AS WE SAW THIS MORNING...MOIST LOW LEVELS (DEW POINTS AROUND 60F) 
AND LIGHT WINDS MAY LEAD TO FOG FORMATION AROUND DAWN. WHILE THIS 
POTENTIAL WILL EXIST BOTH THURSDAY AND FRIDAY MORNINGS...FORECAST 
SOUNDINGS AND SREF PROBS INDICATE MORE FAVORABLE CONDITIONS SATURDAY 
MORNING...ESPECIALLY IF SKIES CLEAR UNDER THE RIDGE. SOMETHING TO 
KEEP IN MIND FOR THE TIME BEING AS FOG WILL BE CONDITIONAL ON SUBTLE 
INFLUENCES. WITH VERY MINIMAL CHANGE TO THE AIRMASS...LOWS WILL BE 
IN THE UPPER 50S TO LOWER 60S BOTH MORNINGS. HIGHS IN UPPER 70S TO 
LOWER 80S FRIDAY.

HEAT AND DAILY ISOLATED AFTERNOON T-STORM CHANCES CONTINUE TO BE THE 
MAIN WX STORY FOR THE LONG TERM...AS WE REMAIN UNDER THE INFLUENCE 
OF RIDGING AND A DECENT MOISTURE FETCH FROM GOM AND LOW OFF CAROLINA 
COAST. MOST DAYS WILL SEE TEMPS IN THE 80S...WITH MONDAY THE WARMEST 
(HIGH TEMPS M/U 80S)...BEFORE A COLD FRONT MOVES THROUGH SOMETIME 
TUESDAY. DEWPOINTS WILL ALSO BE INCREASING DURING THE PERIOD...WHICH 
WILL KEEP NIGHTTIME LOWS IN M/U 60S...AND MAKE IT FEEL MUGGY FOR 
MAY. COULD START APPROACHING RECORD HI MINS TEMPS AT A SOME 
LOCATIONS SUN/MON NIGHT.

&&

.AVIATION /01Z THURSDAY THROUGH MONDAY/...
MODERATE SHOWERS AND OCCASIONAL LIGHTNING NEAR MRB TERMINAL UNTIL
ABOUT 0130Z...THEN ACTIVITY MOVES SOUTH. THUNDERSTORMS NEAR CHO
TERMINAL WILL COLLAPSE OVER THE NEXT 30 MINUTES TO 1
HOUR...RESULTING IN REDUCED VISIBILITY LESS THAN 3 SM AND CEILINGS
BETWEEN 3K AND 4K FEET. CONDITIONS GRADUALLY IMPROVE THROUGH 02Z
AND 03Z. BRIEF RAIN SHOWERS NEAR IAD BETWEEN 01Z AND 02Z MAY LEAD
TO BRIEF MVFR CONDITIONS. ELSEWHERE...TERMINALS WILL BE VFR
CONDITIONS FOR THE MOST PART THROUGH THE OVERNIGHT.

THERE IS A CHANCE OF PATCHY FOG NEAR SOME TERMINALS WHERE SHOWERS
AND THUNDERSTORMS HAVE OCCURRED WEDNESDAY AFTERNOON AND
EVENING...MAINLY MRB...CHO...IAD AND DCA. DON'T ANTICIPATE VSBY
AND CIGS TO LOWER TOO MUCH...PERHAPS BRIEFLY TO IFR FOR A FEW
HOURS OR MAINLY MVFR. THE BEST CHANCE TO ENCOUNTER IFR WOULD BE
BETWEEN 8Z AND 12Z. VFR CONDITIONS ALL TERMINALS FOR THURSDAY.

SUBVFR VSBY POSSIBLE IN FOG DURING THE EARLY MORNING HOURS OF
BOTH FRIDAY AND SATURDAY...FAVORING THE MORE TYPICAL FOG PRONE
AREAS. CURRENT INDICATIONS THAT BETTER FOG POTENTIAL WILL BE
SATURDAY MORNING. OTHERWISE EXPECT LITTLE TO NO WX IMPACTS FRIDAY.
S/SE WINDS UNDER 10 KT.

VFR CONDITIONS EXPECTED THROUGH THE WEEKEND...EXCEPT NEAR AFTERNOON 
T-STORMS...WHERE BRIEF SUB-VFR CONDS ARE POSSIBLE.

&&

.MARINE...
WINDS WILL REMAIN BELOW SMALL CRAFT ADVISORY THE REST OF TONIGHT
AND THURSDAY. 

LITTLE TO NO WX IMPACTS ON THE WATERS THURSDAY NIGHT THRU FRIDAY 
NIGHT UNDER THE INFLUENCE OF HIGH PRESSURE. EXPECT SE WINDS LESS 
THAN 15 KT...AND LIKELY LESS THAN 10 KT MOST OF THE TIME.

WINDS WILL REMAIN WEAK THROUGH THE WEEKEND...SO NOT EXPECTING SCA 
CONDS.

&&

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

&&

$$
SYNOPSIS...LEE/KLW
NEAR TERM...LEE/KLW
SHORT TERM...ADS
LONG TERM...MSE
AVIATION...ADS/MSE/KLW
MARINE...ADS/MSE/KLW

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