Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 241926 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 326 PM EDT FRI APR 24 2015 .SYNOPSIS...
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HIGH PRESSURE MOVES ACROSS THE REGION THROUGH SATURDAY...WITH LOW PRESSURE TRAVERSING THE MID ATLANTIC FOR THE SECOND HALF OF THE WEEKEND. THE LOW WILL SETTLE OFFSHORE TO START THE WORK WEEK AS HIGH PRESSURE BUILDS IN. ANOTHER LOW WILL IMPACT THE REGION MID WEEK.
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&& .NEAR TERM /THROUGH SATURDAY/...
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BREEZY AND DRY CONDITIONS WILL PERSIST OVER THE NEXT FEW HOURS BEFORE HIGH PRESSURE BUILDS IN AND WINDS DIMINISH AROUND SUNSET. CLEAR SKIES AND DIMINISHED WINDS WILL ALLOW TEMPERATURES TO DROP QUICKLY AFTER SUNSET. HIGH CLOUDS WILL GRADUALLY INCREASE FROM SOUTHWEST TO NORTHEAST ACROSS THE REGION. OVERNIGHT TEMPERATURE FORECAST REMAINS A BIT TRICKY. DEWPOINT TEMPERATURES HAVE DROPPED INTO THE UPPER TEENS IN MANY LOCATIONS...LOWER TEENS NEAR THE MASON DIXON LINE. GIVEN THE LOWER DEWPOINTS...DIMINISHING WINDS AND A GOOD CHANCE FOR RADIATIONAL COOLING...HAVE UPGRADED THE FREEZE WATCH TO A WARNING OVER THE NORTHERN SECTOR. HIGHEST CONFIDENCE REMAINS ACROSS NORTH CENTRAL MD...WESTERN LOUDOUN AND THE EASTERN WV PANHANDLE. AREAS FURTHER SOUTH AND EAST STAND A BETTER CHANCE FOR FROST VS FREEZE OVERNIGHT DUE TO A BIT MILDER TEMPERATURES THAN PREVIOUSLY EXPECTED. OVERCAST CONDITIONS WILL MOVE IN LATE WITH LIGHT RAIN DEVELOPING OVER THE SOUTHWEST MID-LATE MORNING SATURDAY THEN SPREADING OVER THE REMAINDER OF THE REGION SATURDAY AFTERNOON AND EVENING. HIGH TEMPERATURES WILL REMAIN WELL BELOW NORMAL WITH READINGS ONLY REACHING THE UPPER 40S OVER THE HIGHER TERRAIN AND MID TO UPPER 50S ELSEWHERE.
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&& .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
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RAIN OVERSPREADING THE ENTIRE REGION BY SAT EVENING CENTER OF SFC LOW REACHES THE OH RIVER VALLEY...WITH A SFC TROUGH EXTENDING ACROSS THE MID ATLANTIC. HIGH CONFIDENCE PCPN WILL BE OVER SOUTHWESTERN HALF OF THE CWA FOR THIS TIME...QUESTION REMAINS ON HOW QUICKLY IT REACHES NORTHEASTERN MD...WITH THE THINKING IT SHOULD REACH SOMETIME BEFORE MIDNIGHT. STILL SOME UNCERTAINTY WHERE THE AXIS OF HEAVIEST PCPN ALIGNS...BUT WITH THE CONSENSUS GENERALLY SHOWING SHORTWAVE MOVING WV INTO SOUTHERN VA...EXPECTING THE HEAVIEST PCPN WILL BE CENTRAL VA AND SOUTH. AS THE LOW PUSHES EAST SUNDAY...PCPN PUSHES TO THE SOUTH AND EAST. AREAS ALONG THE MASON-DIXON COULD DRY AS EARLY AS SUN MORNING...WITH MOST OF THE REMAINING AREA LOOKING TO BE DRY BY SUNSET SUN EVENING. THE ONE AREA THAT COULD SEE PCPN SUN NIGHT- MONDAY IS THE UPSLOPE REGIONS OF THE ALLEGHENIES AS A POTENT SHORTWAVE ROUNDS THE SOUTHWESTERN PERIPHERY OF AN UPPER LVL LOW. WAA OVERNIGHT THE WEEKEND WILL WARM UP BOTH HIGH AND LOW TEMPS. HOWEVER...DEPENDING ON THE TEMPS...CANNOT RULE OUT A SNOWFLAKE MIXING IN FOR A PERIOD LATE SUN NIGHT FOR THIS AREA AS WELL.
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&& .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
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ECMWF 500MB RIDGE BUILDING OVER MID ATLANTIC REGION BY MIDWEEK. LOW ON SOUTHERN TRACK MOVING TO WESTERN KENTUCKY/TENNESSEE BEFORE STALLING AND WEAKENING WEDNESDAY. SHORTWAVE ON NORTHERN TRACK WILL MOVE SOUTHWARD TO REINFORCE THE SOUTHERN LOW. THE LOW WILL MOVE SOUTH OF CWA AND OFFSHORE THURSDAY. SURFACE HIGH OVER THE EASTERN US THROUGH MIDWEEK. LOW CENTER OVER LOUISIANA COAST WILL MOVE NORTHEAST TO AFFECT THE CWA LATE WEDNESDAY AND THURSDAY.
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&& .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
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VFR CONDITIONS WILL PERSIST INTO SATURDAY MORNING FOLLOWED BY LIGHT RAIN OVERSPREADING THE TERMINALS SATURDAY AFTERNOON AND EVENING. SUB-VFR CONDITIONS PSBL SAT NIGHT-SUN WITH RAIN IMPACTING ALL TERMINALS. IMPROVING CONDITIONS BY SUN AFTN...WITH VFR THEN SUN NIGHT THRU MON.
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&& .MARINE...
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SMALL CRAFT CONDITIONS WILL PERSIST INTO EARLY EVENING BEFORE HIGH PRESSURE MOVES OVER THE WATERS AND WINDS DIMINISH. WINDS ARE EXPECTED TO REMAIN BELOW SCA OVERNIGHT AND SATURDAY. HOWEVER...VSBYS WILL DECREASE LATE IN THE DAY AS LIGHT RAIN OVERSPREADS THE WATERS. SUB-SCA CONDITIONS EXPECTED SAT NIGHT. MARGINAL SCA GUSTS ARE PSBL OVER THE CENTRAL CHESAPEAKE BAY WATERS SUN AFTN...WITH SUB-SCA CONDITIONS EVERYWHERE SUN NIGHT. INCRSG WINDS ON MON SHOULD BRING GUSTS UP TO 20 KTS ON ALL WATERS MON-MON NIGHT. PSBL LINGERING SCA GUSTS INTO TUES...WITH SUB-SCA CONDITIONS RETURNING BY TUES NIGHT.
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&& .FIRE WEATHER...
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SPECIAL WEATHER STATEMENT CONTINUES FOR THE ENTIRE AREA THROUGH THIS EVENING. DRY HUMIDITIES AND BREEZY CONDITIONS WILL CONTINUE TO CREATE AN ENHANCED FIRE WEATHER THREAT THROUGH THE REMAINDER OF THIS AFTERNOON. WINDS WILL DIMINISH AROUND SUNSET AND CONDITIONS WILL IMPROVE.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...NONE. MD...FROST ADVISORY FROM 2 AM TO 10 AM EDT SATURDAY FOR MDZ011- 503>506. FREEZE WARNING FROM 2 AM TO 10 AM EDT SATURDAY FOR MDZ003>006- 507-508. VA...FROST ADVISORY FROM 2 AM TO 10 AM EDT SATURDAY FOR VAZ025>027- 029-030-038>040-051>053-501-502-506>508. FREEZE WARNING FROM 2 AM TO 10 AM EDT SATURDAY FOR VAZ028-031- 505. WV...FREEZE WARNING FROM 2 AM TO 10 AM EDT SATURDAY FOR WVZ051>053. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ531-532- 539>541. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ535- 536-538-542. SMALL CRAFT ADVISORY UNTIL 10 AM EDT SATURDAY FOR ANZ533-534- 537-543. SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ530.
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&& $$ SYNOPSIS...KRW NEAR TERM...KRW SHORT TERM...SEARS LONG TERM...CEM AVIATION...SEARS/KRW MARINE...SEARS/KRW FIRE WEATHER...

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