Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 211355 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 955 AM EDT TUE OCT 21 2014 .SYNOPSIS...
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A COLD FRONT WILL MOVE THROUGH THE MID ATLANTIC REGION THIS AFTERNOON. LOW PRESSURE WILL PERSIST ALONG THE COAST THROUGH THURSDAY. HIGH PRESSURE WILL RETURN FOR THE END OF THE WORKWEEK AND INTO THE WEEKEND.
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&& .NEAR TERM /THROUGH TONIGHT/...
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AS OF 13Z...1010MB SFC LOW OVER LAKE ONTARIO WITH AN ATTENDANT COLD FRONT STRETCHING OVER WRN PA AND ERN OHIO. SCATTERED LIGHT RAIN IS MOVING EWD THROUGH CENTRAL WV...AND MAY IMPACT THE ERN WV PANHANDLE BY EARLY AFTERNOON. THE UPPER TROUGH WILL DROP SEWD FROM THE GREAT LAKES INTO WRN PA AND WV THROUGH THIS AFTERNOON...WHILE A SURFACE COLD FRONT MOVES THROUGH THE FORECAST AREA. AS IT DOES...SHOWER ACTIVITY IS EXPECTED GRADUALLY INCREASE IN COVERAGE AND MOVE ACROSS THE AREA. BASED ON CURRENT RADAR AND HRRR/WRF MODELS...ANY PRECIPITATION SHOULD BE CONFINED TO THE AREAS ALONG AND WEST OF THE BLUE RIDGE THROUGH MID AFTERNOON...THEN SPREADING EWD TO THE METRO AREAS LATE AFTERNOON OR EARLY EVENING. AIRMASS WILL BE RELATIVELY DRY...WITH SURFACE DEW POINTS IN THE UPPER 40S TO LOW 50S. SURFACE TEMPS SHOULD REACH WELL INTO THE 60S...AND MAY TOUCH 70 ALONG AND EAST OF I-95. AIR ALOFT WILL BE VERY COOL DUE TO THE UPPER LOW...WHICH WILL HELP INCREASE OVERALL INSTABILITY IN SPITE OF MARGINAL SURFACE DEW POINTS. MODIFIED 12Z KIAD SOUNDING YIELDS SBCAPE BETWEEN 400-500 J/KG...ENOUGH FOR A FEW POTENTIAL ISOLATED THUNDERSTORMS. POPS GENERALLY DECREASE SLOWLY TONIGHT WEST TO EAST (EAST OF THE ALLEGHENY FRONT WITH UPSLOPE RAIN CONTINUING) AS THE UPR LOW CENTER SHIFTS TO THE DELMARVA. MIN TEMPS MAINLY UPR 40S INLAND UNDER THE COLD CORE LOW (UPR 30S IN THE ALLEGHENIES AND LOW 50S NEAR SHORE).
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&& .SHORT TERM /WEDNESDAY/...
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WEDNESDAY...LOW PRESSURE MERELY DRIFTS EAST FROM THE DELMARVA COAST. POPS PERSIST IN THE ALLEGHENIES FOR UPSLOPE AND EAST OF I-95 FROM WRAP AROUND PRECIP. GUSTY NWLY FLOW FROM THE NOW CUTOFF LOW. EXPECT GUSTS 35 TO 40 MPH...PARTICULARLY IN THE LATE AFTERNOON.
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&& .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... BLUSTERY WX LOOKS TO BE IN STORE WED NGT AND THU...ESPECIALLY IN THE ERN PART OF THE FCST AREA. LOW PRES GOES VERTICALLY STACKED OFF THE NJ CST W/ HIGH PRES BUILDING OVR OH/KY. THIS WL CREATE A STRONG PRES GRAD AND BRZY/WINDY CONDS. ISOLD RW WL BE PSBL AS WELL..AGN IN THE ERN PART OF THE AREA. LOW TEMPS IN THE 40S. SKIES SHOULD BE CLRG DURG THU AS THE LOW SLOWLY DRIFTS TOWARDS LONG ISLAND BUT SUSPECT IT WL STILL BE BRZY GIVEN THE PRES GRAD. GRTR SUNSHINE SHOULD ALSO HELP TO DESTABILIZE THE LOWER LVLS OF THE ATMOSPHERE AND BRING WIND TO THE SFC. HIGH TEMPS IN THE U50S TO LM60S. AFTR THU WX SHOULD GET BETTER AND BETTER. HIGH PRES REPLACES THE DEPARTED LOW ALONG THE ERN SEABOARD FRI THRU THE WKND...AND INTO THE BEGINNING OF THE NEW WK. EACH DAY SHOULD BE A LTL WARMER THAN THE ONE B4...STARTING W/ THE LM60S FRI TO THE LM70S MON. LOWS IN THE LM40S EVERYWHERE XCPT THE COOLER HIGHLANDS. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/...
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VFR PREVAILS INTO THIS AFTERNOON AHEAD OF AN APPROACHING UPPER LEVEL LOW. LIKELY RAIN AND ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING WITH PERIODS OF MVFR VSBYS ACROSS THE TERMINALS. AMENDMENTS POSSIBLE TO REFINE TIMING OF ANY PRECIPITATION AND DEVELOPMENT OF TSTMS. SCATTERED SHOWERS PERSIST TONIGHT AS THE LOW CROSSES THE AREA. STRONG NWLY FLOW WEDNESDAY WITH GUSTS AROUND 30 KT BY THE LATE AFTERNOON. CLDY WED NGT BUT CIGS XPCTD TO BE VFR. BRZY NW WINDS XPCTD WED NGT AND THU. VFR/NO PROBS FRI AND SAT.
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&& .MARINE...
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FLOW BECOMING WLY LATE THIS MORNING AS LOW PRESSURE APPROACHES FROM THE NORTHWEST. RAIN AND ISOLATED THUNDER THIS EVENING OVER THE BAY. NWLY FLOW INCREASES THROUGH WEDNESDAY WITH GUSTS AT LEAST 30 KT BY THE LATE AFTERNOON. GALES POSSIBLE WEDNESDAY NIGHT AS THE LOW LINGERS OFF THE DELMARVA. SCA WL LKLY BE ISSUED FOR WED NGT AND THU. WE`LL HV TO KEEP OUR EYES OUT FOR THE PSBLTY OF GUSTS REACHING GALE LVLS. THE WKND IS LOOKING QUITE GOOD FOR MARINE ACTIVITIES - SUNNY SKIES...PLSNT TEMPS...LGT WINDS. WATER TEMPS STILL IN LM60S.
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&& .TIDES/COASTAL FLOODING...
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ANOMALIES HAVE DROPPED TO JUST OVER ONE HALF FOOT AT SENSITIVE LOCATIONS. COASTAL FLOODING IS NOT EXPECTED.
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&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT WEDNESDAY FOR ANZ530>543. && $$ UPDATES...KCS

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