Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 270121 AAA AFDLWX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 921 PM EDT SUN OCT 26 2014 .SYNOPSIS...
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HIGH PRESSURE WILL BUILD OVERHEAD TONIGHT BEFORE MOVING OFF THE COAST MONDAY AND TUESDAY. A COLD FRONT WILL PASS THROUGH THE AREA WEDNESDAY AND HIGH PRESSURE WILL RETURN FOR THURSDAY INTO FRIDAY. ANOTHER COLD FRONT COULD IMPACT THE REGION LATER FRIDAY INTO SATURDAY.
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&& .NEAR TERM /THROUGH MONDAY/...
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BOUNDARY LAYER HAS DECOUPLED AND WINDS HAVE DROPPED OFF MARKEDLY THIS EVENING. TEMPERATURES WILL FALL OFF QUICKLY UNDER CLEAR SKIES...LIGHT WINDS AND DRY CONDITIONS. HIGH PRESSURE IS EXPECTED TO BE RIGHT OVERHEAD BY 12Z MONDAY. TEMPERATURES WILL DROP INTO THE LOW TO MID 30S NORTH AND WEST OF THE I-95 CORRIDOR. A FROST ADVISORY IS IN EFFECT FOR LOCATIONS HUGGING THE BLUE RIDGE...LOW LYING AREAS IN THE NRN PIEDMONT AND NORTH-CENTRAL MARYLAND. HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC COAST BY MONDAY AFTERNOON AND WINDS WILL BECOME SOUTHERLY. DEWPTS AND TEMPS WILL INCREASE ACROSS THE AREA AND FCST MAX TEMPS WILL RANGE FROM THE UPPER 60S TO LOW 70S.
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&& .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
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A 500 MB RIDGE AXIS WILL MOVE OVER THE MID-ATLANTIC MONDAY NIGHT INTO TUESDAY. FLOW ALOFT WILL BECOME SW AND WAA WILL INCREASE TUESDAY. THE SFC HIGH WILL BE WELL OFF THE COAST TUESDAY WITH SOUTHERLY FLOW AT THE SFC. MOSTLY SUNNY CONDITIONS ARE EXPECTED TUESDAY ALBEIT WAA ALOFT. TEMPS ARE EXPECTED TO REACH THE UPPER 70S TO NEAR 80 ON TUESDAY...5-10 DEG WARMER THAN CLIMO.
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&& .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
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BROAD UPPER LEVEL LOW PRESSURE TROUGHING WILL AFFECT THE CWA DURING THE PERIOD. A SHORTWAVE IN THE PATTERN WILL SWEEP ACROSS THE GREAT LAKES REGION INTO UPSTATE NY BEFORE STALLING IN RESPONSE TO THE FORMATION OF A CUT-OFF LOW. SURFACE HIGH PRESSURE BUILDING OVER THE CWA WILL WEAKEN ALLOWING LOW PRESSURE TO CROSS THE AREA FRIDAY. UNCERTAINTY IN THE STRENGTH AND TIMING OF THIS SYSTEM REMAIN HIGH. THERE WILL BE A CHANCE FOR SHOWERS DURING THIS TIME.
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&& .AVIATION /01Z MONDAY THROUGH FRIDAY/...
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VFR CONDITIONS ARE EXPECTED OVERNIGHT AND MONDAY. A COLD FRONT WILL BRING A CHANCE FOR SHOWERS LATE TUESDAY NIGHT AND WEDNESDAY. CIGS/VSBYS MAY APPROACH MVFR LEVELS DURING THIS TIME.
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&& .MARINE...
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WINDS HAVE FALLEN BELOW ADVISORY LEVELS AT ALL SITES. SMALL CRAFT ADVISORY THAT WAS IN EFFECT FOR TONIGHT HAS BEEN CANCELLED. WINDS BECOME SOUTHERLY BY MONDAY AFTERNOON AS HIGH PRESSURE MOVES OFF THE COAST. WINDS SHOULD STAY BELOW SCA CRITERIA THROUGH MONDAY NIGHT. SOUTHERLY CHANNELING UP THE BAY WILL INCREASE TUESDAY AND WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS TUESDAY INTO TUESDAY NIGHT. THE COLD FRONT WILL PASS THROUGH THE WATERS WEDNESDAY. A PRESSURE SURGE MAY CAUSE WIND GUSTS TO EXCEED SCA CRITERIA WEDNESDAY NIGHT INTO THURSDAY FOR PORTIONS OF THE WATERS. TIGHTNING GRADIENT BETWEEN LOW PRESSURE TROUGH CENTER OVER UPSTATE NY AND AN APPPROACHING HIGH FROM WEST MAY PRODUCE WIND GUSTS OF 15 TO 20 KTS FRIDAY NIGHT INTO SATURDAY.
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&& .FIRE WEATHER...
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HUMIDITY VALUES WILL COTNINUE TO RECOVER THIS EVENING AND WINDS HAVE SUBSIDED. THE THREAT FOR ENHANCED FIRE WEATHER CONDITIONS HAS ENDED.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...NONE. MD...FROST ADVISORY FROM 3 AM TO 9 AM EDT MONDAY FOR MDZ003>005. VA...FROST ADVISORY FROM 3 AM TO 9 AM EDT MONDAY FOR VAZ025>031- 036>040-042-050-051-501-502. WV...FROST ADVISORY FROM 3 AM TO 9 AM EDT MONDAY FOR WVZ051>053. MARINE...NONE.
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&& $$ SYNOPSIS...HAS NEAR TERM...KRW SHORT TERM...HAS/GMS LONG TERM...CEM AVIATION...KRW MARINE...KRW FIRE WEATHER...KRW

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