Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 261839 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 239 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 MAY RETURN FOR THURSDAY INTO FRIDAY.
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&& .NEAR TERM /THROUGH MONDAY/...
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LOW PRESSURE IS LOCATED NEAR MAINE THIS AFTERNOON AND THE MID-ATLANTIC IS IN A POST FRONTAL PATTERN. A TIGHT PRESSURE GRADIENT IS ACROSS THE REGION DUE TO APPROACHING HIGH PRESSURE ACROSS THE OHIO VALLEY. GUSTY NW WINDS WILL CONTINUE THIS AFTERNOON. FULL MIXING THIS AFTERNOON HAS ALLOWED GUSTS UP TO 35 KTS TO REACH THE SFC. WINDS SHOULD DIMINISH BY SUNSET TODAY. MIXING HAS ALSO CAUSED DEWPTS TO DROP INTO THE 20S ACROSS THE MID-ATLANTIC LEAVING THE REGION VERY DRY. THE COMBINATION POSES A THREAT FOR THE SPREAD OF WILDFIRES. SEE FIRE WX SECTION BELOW. HIGH PRESSURE WILL CONTINUE TO MOVE INTO THE MID-ATLANTIC TONIGHT AND WESTERLY WINDS WILL BECOME LIGHT OVERNIGHT. THE CENTER OF THE HIGH IS EXPECTED TO BE RIGHT OVERHEAD BY 12Z MONDAY. LIGHT WINDS AND CLEAR SKIES WILL ALLOW RADIATIONAL COOLING TO OCCUR AND THEREFORE TEMPS TO 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. PREV DISCUSSION... THE COLD FRONT WILL SLOWLY PASS THROUGH THE AREA LATE TUESDAY NIGHT AND WEDNESDAY. CLOUDS WILL INCREASE AHEAD OF THIS SYSTEM AND A FEW SHOWERS ARE POSSIBLE DURING THIS TIME. HOWEVER...PRECIPITATION AMOUNTS SHOULD BE LIGHT SINCE LITTLE MOISTURE WILL BE ASSOCIATED WITH THE BOUNDARY.
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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 GREAT LAKES AREA 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 /18Z SUNDAY THROUGH FRIDAY/...
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VFR CONDITIONS ARE EXPECTED TODAY...TONIGHT AND MONDAY. NW WINDS WITH GUSTS UP TO 25 KTS WILL PERSIST THIS AFTERNOON. WINDS WILL SUBSIDE BY SUNSET AND DIMINISH INTO THE EVENING HOURS. HIGH PRESSURE WILL MOVE OVERHEAD MONDAY MORNING AND WINDS SHOULD BE LIGHT IF NOT CALM. HIGH PRESSURE MOVES OFF THE COAST MONDAY AND WINDS BECOME SOUTHERLY. SOUTHERLY WINDS WILL CONTINUE THROUGH TUESDAY. 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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NW WINDS WITH GUSTS UP TO 30 KTS WILL PERSIST THIS AFTERNOON. A PRESSURE GRADIENT RESPONSIBLE FOR THE WINDS WILL MOVE OFF THE EAST COAST LATE TONIGHT. A SCA IS IN EFFECT FOR ALL THE WATERS THROUGH SUNSET. IT CONTINUES FOR THE LOWER TIDAL POTOMAC AND MD BAY MAIN CHANNEL. HIGH PRESSURE WILL MOVE OVER THE WATERS MONDAY MORNING AND WINDS WILL DIMINISH TO W 10-15 KTS. 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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GUSTY NW WINDS 15-25 MPH WITH GUSTS UP TO 30 MPH WILL CONTINUE THIS AFTERNOON AS THE MID-ATLANTIC STAYS IN A POST-FRONTAL PATTERN. DEEP MIXING WAS ABLE TO DROP DEWPTS AND RH VALUES INTO THE 20S TODAY RESULTING IN DRY CONDITIONS. DUE TO DRY FUELS NEAR THE BLUE RIDGE MTNS AND LOCATIONS IN THE PIEDMONT AND NOVA...A SPECIAL WEATHER STATEMENT WAS ISSUED FOR THE ENHANCED THREAT OF THE SPREAD OF WILDFIRES. THIS WILL EXPIRE AROUND SUNSET TONIGHT AS WINDS DIMINISH. DRY CONDITIONS AND GUSTY WINDS HAVE BEEN OBSERVED IN THE ENTIRE OUTLOOK AREA. ALTHOUGH RECENT RAINS HAVE MADE SOME LOCATIONS DAMPER THAN OTHERS...OPEN BURNING OF ANY TYPE IS CONSIDERED VERY HAZARDOUS THIS TIME OF YEAR. ACCIDENTAL ESCAPED DEBRIS BURNS ARE THE NUMBER ONE CAUSE OF WILDFIRES.
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&& .LWX WATCHES/WARNINGS/ADVISORIES... 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...SMALL CRAFT ADVISORY UNTIL 2 AM EDT MONDAY FOR ANZ530>534-537- 539>541-543. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ535- 536-538-542. && $$ SYNOPSIS...HAS NEAR TERM...HAS SHORT TERM...HAS/GMS LONG TERM...CEM AVIATION...HAS MARINE...CEM/HAS FIRE WEATHER...HAS

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