Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 221852
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
252 PM EDT WED OCT 22 2014

.SYNOPSIS...
LOW PRESSURE WILL PERSIST ALONG THE MID-ATLANTIC COAST THROUGH
THURSDAY. HIGH PRESSURE WILL RETURN TO THE AREA FRIDAY AND REMAIN
THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SURFACE LOW PRESSURE REMAINS OVER THE OCEAN EAST OF THE DELMARVA
PENINSULA THIS AFTERNOON. THERE HAS BEEN LITTLE CHANGE IN
STRENGTH OR ORGANIZATION IN THE PAST SEVERAL HOURS...BUT THE LOW
IS EXPECTED TO DEEPEN THIS AFTERNOON AND MOVE NE TOWARDS CAPE COD.
LIGHT RAIN CONTINUES TO WRAP AROUND THE BACK SIDE OF THE LOW AND
IMPACTS JUST ABOUT ALL OF THE CWA EAST OF THE BLUE RIDGE AND
PORTIONS OF THE SHENANDOAH VALLEY. RAIN SHIELD WILL GRADUALLY
SHIFT TO THE NORTH AND EAST LATE THIS AFTERNOON...BUT LIGHT RAIN
IS LIKELY PERSIST IN THE WASHINGTON DC METRO AND AREAS TO THE
NORTH AND EAST THROUGH THE AFTERNOON. N-NW WINDS GUSTING TO 20-25
MPH THIS AFTERNOON AS THE PRESSURE GRADIENT INCREASES ON THE BACK
SIDE OF THE STRENGTHENING LOW AND COOLER AIR ALOFT ADVECTS INTO
THE REGION. LATE AFTERNOON HIGH TEMPS MOSTLY IN THE 50S...AND
AROUND 60 IN ALONG THE I-95 CORRIDOR.

MOST AREAS WILL BE DRY OVERNIGHT...EXCEPT POSSIBLY LEFTOVER RAIN
NEAR CHESAPEAKE BAY AND UPSLOPE PRECIPITATION OVER THE POTOMAC
HIGHLANDS. SOME SNOW MAY MIX WITH RAIN IN THE HIGHEST
ELEVATIONS...BUT NOT CONFIDENT ABOUT PRECIPITATION AS THE AREA
UNDER THE INVERSION WILL BE SHALLOW. GUSTY WINDS
CONTINUE...BUT MAY DIMINISH FOR A FEW HRS OVERNIGHT IF AN
INVERSION IS ABLE TO DEVELOP. HIGHEST 925MB JET WILL BE PRIMARILY
ALONG AND EAST OF THE BLUE RIDGE...SO NOT EXPECTING WIND ADVISORY
GUSTS IN THE POTOMAC HIGHLANDS. OVERNIGHT LOWS PRIMARILY IN THE 40S.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
LOW CONTINUES TO GRADUALLY PULL AWAY THURSDAY. NOT EXPECTING
RAIN...EXCEPT POSSIBLE UPSLOPE RAIN OVER THE POTOMAC HIGHLANDS.
CLOUD SHIELD EXPECTED TO STAY IN PLACE OVER NORTHERN AND EASTERN
PORTIONS OF THE AREA...BUT CLEARING EXPECTED IN THE SOUTHERN AND
WESTERN COUNTIES. PRESSURE GRADIENT WILL REMAIN IN PLACE...SO N-NW
WINDS GUSTING TO 25-30 MPH EXPECTED ONCE AGAIN. HIGH TEMPS
PRIMARILY IN THE UPPER 50S TO LOW 60S.

COASTAL LOW MOVES FURTHER AWAY THURSDAY NIGHT AND HIGH PRESSURE
BUILDS INTO THE OHIO VALLEY. CLEARING EXPECTED OVER DC/BALTIMORE
AREAS. WINDS DIMINISH WITH DECOUPLING. LOWS IN THE 40S...AND UPPER
30S IN HIGHER ELEVATIONS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
OVERALL...THE LONG TERM WILL BE A RATHER QUIET PERIOD. HIGH PRESSURE
WILL BEGIN TO BUILD INTO THE AREA FRIDAY AND WINDS WILL GRADUALLY
EASE. TEMPS WILL BE NEAR NORMAL...IN THE LOW TO MID 60S...FRIDAY AND
SATURDAY AS HIGH PRESSURE CENTERED OVER THE GULF COAST RIDGES INTO
THE AREA. AN UPPER LEVEL TROUGH AXIS PASSING OVERHEAD COULD LEAD TO
SOME AN INCREASE IN UPPER LEVEL CLOUDS FRIDAY NIGHT...BUT THE TROUGH
SHOULD HAVE LITTLE TO NO IMPACT ON SENSIBLE WEATHER AT THE SURFACE.

A WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE NEAR THE HUDSON BAY
WILL CROSS THE AREA SATURDAY NIGHT. EXPECT THIS TO BE A DRY COLD
FRONT...WITH ONLY A COUPLE DEGREE DROP IN TEMPERATURES RESULTING. IT
IS WORTH NOTING THAT MODELS ARE TRENDING THE SOUTHERN EDGE OF PRECIP
CLOSER TO THE AREA...BUT AT THIS POINT IT IS STILL EXPECTED TO STAY
TO OUR NORTH SO NO POPS IN THE FORECAST. SUNDAY WILL SEE HIGHS IN THE
UPPER 50S TO LOWER 60S.

HIGH PRESSURE WILL BUILD IN AGGRESSIVELY EARLY NEXT WEEK AND SHOULD
BE OVERHEAD BY MONDAY MORNING. TEMPERATURES WILL BE ON THE RISE AS
THIS HIGH PRESSURE MOVES OFF THE COAST TUESDAY AND SOUTHERLY FLOW
FILLS IN. MANY PLACES COULD BE INTO THE 70S ON TUESDAY. A COLD FRONT
MAY APPROACH THE REGION WEDNESDAY NIGHT.



&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
RAIN IS EXPECTED TO TAPER OFF BY LATE AFTERNOON AT DC AREA
TERMINALS. BALTIMORE AIRPORTS WILL BE LAST TO SEE RAIN END LATE
THIS EVENING. PRIMARILY MVFR CONDS...BUT PDS OF VFR WHEN LOWER
CLOUDS SCATTER. NW WINDS WITH GUSTS 25 TO 30 KT. GUSTY WINDS
CONTINUE TONIGHT AND THURSDAY.

CONFIDENCE IS LOW IN THE OCCURRENCE OF AVIATION HAZARDS THROUGH THE
LONG TERM PERIOD.

&&

.MARINE...
PERIODIC RAIN TODAY. SCA THROUGH TODAY AS NWLY FLOW INCREASES.
GALES OVER THE SRN MD WATERS AND LOWER TIDAL POTOMAC TONIGHT
THROUGH THURSDAY AFTERNOON AS THE GRADIENT INCREASES. ELECTED NOT TO
ISSUE A GALE OVER THE NORTHERN WATERS AS HIGHEST WINDS ALOFT NOT
LIKELY TO MIX DOWN...BUT WILL CONTINUE TO MONITOR.

A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED DURING THE DAY FRIDAY
AS GUSTY NORTHWESTERLY WINDS GRADUALLY EASY DUE TO HIGH PRESSURE
RIDGING INTO THE AREA. A SMALL CRAFT ADVISORY MAY BE NECESSARY LATE
SATURDAY NIGHT AND SUNDAY MORNING FOR BREEZY WINDS ON THE BACKSIDE
OF A DRY COLD FRONT THAT WILL CROSS THE REGION.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ530>532-
     535-536-538>540-542.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ533-
     534-537-541-543.
     GALE WARNING FROM 6 PM THIS EVENING TO 6 PM EDT THURSDAY FOR
     ANZ533-534-537-541-543.

&&

$$
SYNOPSIS...KCS
NEAR TERM...KCS
SHORT TERM...KCS
LONG TERM...CEB
AVIATION...KCS/CEB
MARINE...KCS/CEB








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