Area Forecast Discussion
Issued by NWS Sterling, VA

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029
FXUS61 KLWX 010014
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
814 PM EDT SAT APR 30 2016

.SYNOPSIS...
HIGH PRESSURE OFF THE NEW ENGLAND COAST WILL MOVE
FURTHER OFFSHORE TONIGHT. LOW PRESSURE WILL TRACK ACROSS
PENNSYLVANIA SUNDAY NIGHT WITH ASSOCIATED COLD FRONT MOVING
THROUGH THE AREA EARLY MONDAY. ANOTHER COLD FRONT IS EXPECTED
THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
LOW PRESSURE WILL TRACK THROUGH THE OHIO VALLEY TONIGHT...AND A
BOUNDARY WILL REMAIN NEARLY STATIONARY FROM THE ALLEGHENY
HIGHLANDS INTO NORTH CAROLINA. WARM MOIST AIR WILL OVERRUN THE
COOL AIR BEHIND THE BOUNDARY...RESULTING IN A SOAKING RAIN
TONIGHT. ONE-HALF TO ONE INCH OF RAIN EXPECTED. RAIN TAPERS OFF
TO -SHRA BY 18Z SUNDAY AS DRY SLOT MOVES IN. NOT LOOKING FOR MUCH
INSTABILITY THAT COULD KICK T-STORMS AS CLOUDS SHOULD HANG TOUGH
AND AN INVERSION REMAINS IN PLACE. THE BEST CHANCE FOR
THUNDERSTORMS WILL BE DURING THE MID TO LATE AFTERNOON HOURS
ACROSS THE ALLEGHENY AND POTOMAC HIGHLANDS TOWARD CENTRAL
VIRGINIA.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
POTENTIAL FOR FOG AND ADDITIONAL SHOWERS SUN NIGHT AS MOIST
SOUTHEAST FLOW PREVAILS AND LOW PRESSURE TRACKS ACROSS PA.
ASSOCIATED CDFNT SWEEPS THROUGH THE AREA AROUND 12Z MON WITH DRY
WESTERLY FLOW TAKING OVER. MUCH WARMER THAN IT HAS BEEN RECENTLY
WITH HIGHS TOPPING OUT IN THE LOW 80S. ANOTHER UPPER AIR
DISTURBANCE TRACKS ACROSS THE AREA MON NIGHT WITH SHOWERS POSSIBLE
LATE MON NIGHT.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
WEAK HIGH PRESSURE BUILDS IN TUE BEFORE ANOTHER UPPER LEVEL
TROUGH SWINGS THROUGH THE AREA FROM THE ERN GRT LKS WED-THU. MUCH
COLDER AIR ALOFT MOVING WILL RESULT IN INSTABILITY SHOWERS AND
POSSIBLE T-STORMS. HIGH PRESSURE RETURNS FOR NEXT WEEKEND WITH
IMPROVING WX CONDITIONS.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
RAIN WILL CONTINUE OVER THE TERMINALS. MODERATE RAINFALL RATES ARE
EXPECTED OVERNIGHT. VSBYS WILL BE REDUCED TO BETWEEN 2 AND 4 MILES
AND BANDS OF HEAVIER RAINFALL. MVFR CIGS ACROSS MOST LOCATIONS
THIS EVENING WILL DROP TO IFR LEVELS OVERNIGHT. IFR CIGS WILL
CONTINUE THROUGH SUNDAY MORNING AS RAIN SLOWLY TAPERS OFF. CIGS
MAY IMPROVE A BIT SUNDAY AFTERNOON...BUT LOW IFR/SUBIFR CIGS WILL
RETURN SUNDAY NIGHT. A FEW SHOWERS ARE POSSIBLE SUNDAY AFTERNOON
INTO SUNDAY NIGHT. AN ISOLATED THUNDERSTORM CANNOT BE RULED
OUT...BUT ANY THUNDERSTORM COVERAGE WILL BE MINIMAL DUE TO MARINE
AIR IN PLACE. FOG POTENTIAL AS WELL SUNDAY NIGHT WITH VSBYS BELOW
1 MILE POSSIBLE. IFR/SUBIFR CIGS AND VSBYS EARLY MONDAY MORNING
WILL IMPROVE...AND IT WILL TURN OUT DRY AND BREEZY THANKS TO A
WESTERLY FLOW.

A WAVE OF LOW PRESSURE WILL PASS BY TO THE SOUTH MONDAY NIGHT INTO
TUESDAY. RAIN AND SUBVFR CONDITIONS ARE POSSIBLE. VFR CONDITIONS
MAY RETURN TOWARD THE MIDDLE PORTION OF NEXT WEEK.

&&

.MARINE...
WINDS 10 KT OR LESS THROUGH SUN NIGHT THEN SCA CONDITIONS LIKELY
MON UNDER WESTERLY FLOW.

&&

.TIDES/COASTAL FLOODING...
THE ONSHORE FLOW HAS CAUSED TIDAL ANOMALIES AROUND ONE FOOT ABOVE
NORMAL. WATER LEVELS SHOULD REMAIN BELOW MINOR FLOODING THRESHOLDS
TONIGHT. HOWEVER...THE ASTRONOMICAL HIGH TIDE SUNDAY WILL BE THE
HIGHER OF THE TWO. MINOR FLOODING FOR SENSITIVE AREAS IS
POSSIBLE...ESPECIALLY NEAR ANNAPOLIS AND STRAITS POINT.

ELEVATED WATER LEVELS WILL CONTINUE SUNDAY NIGHT INTO EARLY
MONDAY...BUT ANOMALIES SHOULD FALL CLOSER TO NORMAL LATER MONDAY.

&&

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

&&

$$
SYNOPSIS...LFR
NEAR TERM...BJL/LFR
SHORT TERM...LFR
LONG TERM...MSE
AVIATION...BJL/MSE/LFR
MARINE...BJL/MSE/LFR
TIDES/COASTAL FLOODING...BJL/LFR



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