Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 270053
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
853 PM EDT THU MAR 26 2015

.SYNOPSIS...
A COLD FRONT IS APPROACHING THE CHESAPEAKE BAY. AN UPPER-LEVEL
TROUGH WILL SLOWLY MOVE THROUGH BEHIND THE FRONT LATE TONIGHT
THROUGH SATURDAY. HIGH PRESSURE WILL BUILD OVERHEAD SUNDAY BEFORE
MOVING OFF THE COAST EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...

THIS IS ONE OF THOSE DAYS WHERE THE ADAGE "IF YOU DON`T LK THE WX
WAIT A MINUTE AND IT WL CHG" APPLIES. RAIN IN THE MRNG W/ TEMPS IN
THE 50S...THEN SOARING INTO THE M70S AFTR THE WARM FNT PUSHED
N...THEN BACK INTO THE 50S AS THE CD FNT MOVES THRU IN THE EVE.
PEA SIZE HAIL WAS THE WORST WX REPORTED W/ THE CD FNT WHICH IS NOW
THRU ALL XCPT LWR SRN MD.

PRVS DSCN..

NORTHWEST WINDS BEHIND THE FRONT OVERNIGHT WILL USHER IN MUCH
COLDER CONDITIONS. A COLD RAIN IS EXPECTED ACROSS MOST AREAS AS AN
UPPER-LEVEL DISTURBANCE SWINGS THROUGH IN THE SOUTHWEST FLOW
ALOFT. HOWEVER...THERE WILL BE ENOUGH COLD AIR FOR SNOW ALONG THE
RIDGE TOPS OF THE ALLEGHENY HIGHLANDS AND BLUE RIDGE MOUNTAINS.
SNOW ACCUMULATIONS WILL MOST LIKELY BE CONFINED TO ELEVATIONS
ABOVE 2500 FEET.

LOW PRESSURE DEVELOP ALONG THE NORTH CAROLINA COAST FRIDAY MORNING
BEFORE MOVING OUT TO SEA LATER IN THE DAY. AN UPPER-LEVEL TROUGH
WILL BUILD OVERHEAD DURING THIS TIME. A NORTHWEST FLOW WILL
CONTINUE TO USHER IN CHILLY CONDITIONS FOR THIS TIME OF YEAR. RAIN
ACROSS THE SOUTHEASTERN PORTION OF THE CWA...CLOSER TO THE LOW
WILL MOVE OUT OF THE AREA DURING THE LATE MORNING AND EARLY
AFTERNOON HOURS. ELSEWHERE...IT WILL BE DRY FOR MOST OF THE DAY
BUT A COUPLE SHOWERS CANNOT BE RULED OUT DUE TO THE INSTABILITY
FROM THE UPPER-LEVEL TROUGH BUILDING OVERHEAD. THERE WILL BE MORE
UPSLOPE SNOW SHOWERS ALONG AND WEST OF THE ALLEGHENY FRONT...BUT
ANY ACCUMULATION WILL BE LIGHT. MAX TEMPS WILL RANGE FROM THE
UPPER 20S AND LOWER 30S ALONG THE RIDGE TOPS OF THE ALLEGHENY
HIGHLANDS TO THE UPPER 40S AND LOWER 50S ACROSS MOST OTHER
LOCATIONS.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
MODERATE CAA WILL PERSIST THROUGH THE OVERNIGHT FRI AS THE SFC LOW
BEGINS TO MOVE AWAY FROM OUR AREA...ALTHOUGH CLOUDY SKIES AND BREEZY
WINDS WILL PREVENT TEMPERATURES FROM PLUMMETING TOO MUCH. EXPECT SAT
MORNING LOWS IN THE MID 30S NEAR THE BAY...LOW 30S IN THE
METROS...AND MID/UPPER 20S TO THE WEST. LEFT A CHANCE OF UPSLOPE
SNOW SHOWERS IN FAVORED WESTERN REGIONS...AND SLT CHANCE POPS
ELSEWHERE TO ACCOUNT FOR ANY RESIDUAL PRECIP.

CAA CONTINUES DURING THE DAY SAT AND WINDS INCREASE AS THE PRESSURE
GRADIENT INCREASES DUE TO THE STRENGTHENING DEPARTING SFC LOW.
INSTABILITY SHOWERS WL BE PSBL FM LATE MRNG THRU LATE AFTN. GIVEN
THE COLD LOW LVLS OF THE ATMOSPHERE W OF I-95 COULD SEE
SNSH...ALTHO NO ACCUM IS XPCTD.

SAT NIGHT WILL BE UNSEASONABLY COLD...WITH TEMPERATURES AREA WIDE IN
THE MID/LOW 20S AND IN THE TEENS TO THE WEST. IT COULD BE EVEN
COLDER IF CLOUDS CLEAR SOONER.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
SUNDAY WILL BE SUNNY...CONTINUED CAA THROUGH THE DAY AND BREEZY
WINDS WILL MAKE IT FEEL MUCH COLDER...WITH APPARENT TEMPS IN THE
MID/UPPER 40S. UPPER LEVEL RIDGE OVER REGION SHIFTING OFFSHORE BY
MONDAY MORNING. PACKETS OF PVA EMBEDDED IN TROUGH ON NORTHERN
TRACK CROSSING THE REGION DURING THE DAY MONDAY...MONDAY
NIGHT...TUESDAY NIGHT...AND THURSDAY. RIDGE BUILDING OVER THE
REGION AT MIDWEEK WILL FLATTEN AS TROUGH PASSES NORTH OF AREA AT
WEEKS END.

SURFACE HIGH ALONG EASTERN SEABOARD MOVING OFFSHORE ALLOWING COLD
FRONT AND LIGHT PRECIPITATION TO AFFECT AREA MONDAY. NEXT SESSION OF
PRECIPITATION TRIGGERED BY LOW SYSTEM AT MIDWEEK. TEMPERATURE
PROFILE SUPPORTS BRIEF PERIODS OF MIXED PRECIPITATION TUESDAY
MORNING AND AGAIN WEDNESDAY MORNING NEAR THE MASON-DIXON LINE.
PASSAGE OF WEAK FRONTAL SYSTEM WILL AFFECT THE REGION LATE
WEDNESDAY AND THURSDAY. TIGHTENING GRADIENT BETWEEN FRONT AND
HIGH PRESSURE OFFSHORE PRODUCING WINDS OF 10 TO 15 KNOTS.

&&

.AVIATION /01Z FRIDAY THROUGH TUESDAY/...

COLD FNT HAS NOW MOVED THRU THE MAJOR TAF SITES. WIND SHIFT HAS
OCCURRED. CIGS ARE XPCTD TO STAY IN MVFR RNG THRU MID MRNG.

GUSTY NORTHWEST WINDS ARE EXPECTED FRIDAY NIGHT THROUGH SUNDAY.

VFR CONDITIONS ARE EXPECTED MOST OF THE TIME SUNDAY NIGHT THROUGH
TUESDAY.

&&

.MARINE...
A COLD FRONT WILL PASS THROUGH THE WATERS BETWEEN 01Z AND 04Z
THIS EVENING. A LINE OF GUSTY SHOWERS AND ISOLATED THUNDERSTORMS
IS POSSIBLE ALONG THE FRONT. NORTHWEST WINDS ARE EXPECTED BEHIND
THE FRONT. A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH
FRIDAY. HOWEVER...IT MAY BE MARGINAL ON FRIDAY.

A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FRIDAY NIGHT INTO
SUNDAY DUE TO GUSTY NORTHWEST WINDS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT FRIDAY FOR ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...BJL/HTS/IMR/JSE



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