Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 031401
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1001 AM EDT WED JUN 3 2015

.SYNOPSIS...
HIGH PRESSURE WILL RESIDE OVER THE NORTHEAST WITH LOW PRESSURE
FORMING OFF THE NORTH CAROLINA COAST. THE COMBINATION WILL KEEP A
COOL NORTHEAST BREEZE OVER THE REGION THROUGH THURSDAY NIGHT.
FRIDAY THE LOW WILL MOVE FURTHER OUT TO SEA...ALLOWING HIGH
PRESSURE TO MOVE INTO THE REGION FOR SATURDAY. THE NEXT LOW
PRESSURE SYSTEM FROM THE WEST WILL MOVE THROUGH THE REGION MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
LOCAL AREA WILL REMAIN UNDER SFC WEDGE WITH CLOUDY AND COOL
CONDITIONS ONCE AGAIN. ONLY WEAK LIFT WILL BE AVAILABLE DUE TO
LOW-LEVEL CONVERGENCE UNDER NORTHEAST FLOW SO LIGHT RAIN AND
DRIZZLE WILL BE THE PREDOMINANT PRECIP MODES TODAY. THESE
CONDITIONS WILL PERSIST THROUGH TONIGHT. THE MOST WIDESPREAD
PRECIPITATION WILL BE ACROSS THE CENTRAL AND SOUTHERN PORTIONS OF
THE CWA WHERE MOISTURE IS A BIT DEEPER.

MAX TEMPS WILL BE WELL BELOW CLIMO...RANGING FROM THE 50S ALONG
THE ALLEGHENY HIGHLANDS TO THE LOWER AND MIDDLE 60S ACROSS MOST
OTHER LOCATIONS. MIN TEMPS TONIGHT WILL DROP INTO THE 50S FOR MOST
AREAS.

&&

.SHORT TERM /THURSDAY/...
DEEPER MOISTURE AND STRONGER LIFT WILL OVERSPREAD THE AREA FROM
THE SOUTH ON THU AS CLOSED MID-UPPER LEVEL LOW OVER NORTHEAST TN
MOVES ENE. THIS WILL RESULT IN RAIN BECOMING HEAVIER ESPECIALLY
OVER SOUTHERN MD LATE TONIGHT THROUGH THU. MODEL AND ENSEMBLE QPF
AVERAGES BETWEEN QUARTER INCH EAST OF THE BLUE RIDGE TO THREE
QUARTERS OF AN INCH OVER SOUTHERN MD.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
LOW PRESSURE WILL FORM OFF THE NC OR VA COAST BY THU NIGHT. THE
GRADIENT BETWEEN THAT LOW OFFSHORE AND HIGH PRESSURE NOSING DOWN
FROM THE NORTHEAST STATES WILL KEEP WINDS GUSTY ON THE WATERS...AS
WELL AS CLOUDS AND AT LEAST A CHANCE OF SHOWERS AND THUNDERSTORMS.
MODEL PRECIP HAS BEEN BACKING OFF THE PAST 24 TO 48 HOURS...AND
EVEN THE 90TH PERCENTILE OF THE MULTI MODEL ENSEMBLE HAS AN INCH
OR LESS OF RAIN OVER 24 HRS. FOR ALL OF THOSE REASONS WILL BE
REMOVING HAZARD OF POTENTIAL FLOODING FROM OUR HAZARDOUS WEATHER
OUTLOOK. WHILE WE CANT SAY WITH CERTAINTY SOME POCKETS OF HEAVY
RAIN WONT HAPPEN WITH PRECIP WATER AROUND 1.7 INCHES...THE THREAT
LOOKS ISOLATED AT BEST...WITH THE BEST CHANCE IN SOUTHERN MD WHERE
THEY CAN HANDLE MORE RAIN.

PAST FRIDAY...THE FORECAST GETS MORE UNCERTAIN. THE MOST LIKELY
EXPECTATION IS THAT HIGH PRESSURE WILL MOVE MORE FULLY OVER THE
REGION SATURDAY WITH NOT AS MANY CLOUDS...AND TEMPS REACHING
AROUND 80 IN THE AFTERNOON. THEN SUNDAY...MORE OF THE SAME WITH
WEAK LOW PRESSURE LIKELY FORMING OFF NC AGAIN WITH HIGH PRES
NOSING DOWN THE NORTHEAST STATES. THE NEXT FRONTAL SYSTEM FROM THE
WEST WILL MOVE INTO THE REGION MONDAY WITH A 50 TO 60 PERCENT
CHANCE OF SHOWERS OR THUNDERSTORMS FOR MOST.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
IFR CIGS THIS MORNING WITH CIGS IMPROVING TO MVFR LATE THIS
MORNING INTO EARLY THIS AFTERNOON. LIGHT RAIN AND DRIZZLE IS
EXPECTED DURING THIS TIME. DEEPER MOISTURE AND STRONGER LIFT WILL
OVERSPREAD THE AREA FROM THE SOUTH LATE TONIGHT WITH MODEL
GUIDANCE INDICATING CIGS DROPPING TO IFR IN -RA AND VSBYS IN THE
2-4SM RANGE WITH PERHAPS SOME IMPROVEMENT TO MVFR DURING THE
DAYTIME HRS ON THU. WOULD EXPECT MVFR TO LAST THRU FRI...WITH A
SHIFT TO VFR ON SAT. SUNDAY COULD BE A RETURN TO MVFR WITH SFC LOW
REDEVELOPING OFF NC AND HIGH PRES NOSING DOWN FROM THE NE.

&&

.MARINE...
A NORTHEAST FLOW WILL CONTINUE THROUGH THURSDAY. A SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE MARYLAND CHESAPEAKE BAY AND LOWER
TIDAL POTOMAC RIVER DURING THIS TIME. THE SMALL CRAFT ADVISORY MAY
NEED TO BE EXTENDED INTO FRIDAY GIVEN THE SLOWNESS OF THE LOW
INDICATED BY THE ENSEMBLES.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR ANZ530>534-
     536-537-540>543.

&&

$$
SYNOPSIS...CAS/LFR
NEAR TERM...BJL/LFR
SHORT TERM...LFR
LONG TERM...CAS
AVIATION...BJL/CAS/LFR
MARINE.../BJL/CAS/LFR


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