Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 230135 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 935 PM EDT TUE APR 22 2014 .SYNOPSIS...
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A COLD FRONT WILL CONTINUE TO MOVE EAST ACROSS THE AREA THIS EVENING. HIGH PRESSURE THEN BUILDS THROUGH EARLY THURSDAY BEFORE MOVING OFF THE COAST. A COLD FRONT IS EXPECTED TO PASS THROUGH THE AREA LATE FRIDAY BEFORE CANADIAN HIGH PRESSURE BUILDS IN LATE SATURDAY INTO MONDAY.
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&& .NEAR TERM /THROUGH WEDNESDAY/...
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AS OF 01Z...996MB SFC LOW IS CENTERED OVER NRN NEW HAMPSHIRE WITH AN ATTENDANT COLD FRONT EXTENDING SOUTH DOWN THE HUDSON VALLEY THEN SW ACROSS THE CENTRAL MID-ATLANTIC. THUNDERSTORMS HAVE MOVED OFF THE SHORE NEAR BALTIMORE AND WILL PUSH ACROSS THE EASTERN SHORE THROUGH THE LATE EVENING. JUST A FEW SHOWERS WEST OF THE FRONT WITH NW FLOW INCREASING. OVERNIGHT GUSTS OF 20 TO 25 MPH CAN BE EXPECTED...INCREASING TO 30 TO 40 MPH AROUND SUNRISE. MIN TEMPS LOW TO MID 40S INLAND...UPR 40S URBAN/NEARSHORE. HIPRES BUILDS IN FROM THE GREAT LAKES ON WED. COLD AIRMASS WILL BE MODERATED A BIT BY THE HIGH SUN ANGLE. FORECAST UPDATE A BLEND OF MAV AND MET WHICH CAME OUT A BIT HIGHER THAN THE PREVIOUS. THIS IS REASONABLE WITH SUNNY SKIES AND DOWNSLOPING FLOW. MAX TEMPS GENERALLY RANGE FROM THE MID 50S TO MID 60S EXCEPT FOR COOLER HIGHS IN THE 40S ALONG HIGHER ELEVATIONS RIDGES.
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&& .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... SFC LOW PRESSURE SHOULD BE MOVING TOWARDS NEWFOUNDLAND WED NIGHT AND HIGH PRESSURE WILL MOVE INTO THE MID ATLANTIC FROM THE WEST. THE PRESSURE GRADIENT RESPONSIBLE FOR THE GUSTY WINDS WEDNESDAY WILL DEPART TO OUR EAST WED EVENING. TEMPS WILL REACH THE LOW 30S WEST OF THE BLUE RIDGE AS CLEARING AND CALM WINDS WILL ALLOW FOR TEMPS TO DROP. ELSEWHERE...MID TO UPPER 30S EXPECTED TO AROUND 40 IN THE METROS. UPPER LEVEL RIDGING WILL MOVE OVERHEAD THURSDAY RESULTING IN A SUNNY DAY WITH TEMPS IN THE 60S. A WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE ACROSS THE NRN PLAINS WILL APPROACH THE REGION. CLOUDS WILL INCREASE FROM THE WEST THURSDAY AS HIGH PRESSURE WILL MOVES OFF THE COAST BY THURSDAY NIGHT. A BRIEF PERIOD OF RETURN FLOW WILL INCREASE ACROSS THE REGION THURSDAY NIGHT AND FRIDAY. TEMPS WILL REACH 70-75 DEGREES FRIDAY AFTERNOON. THE WEAK COLD FRONT WILL CROSS THE APPALACHIANS FRIDAY AFTERNOON AND SHOWERS ARE EXPECTED TO MOVE AHEAD OF THE FRONT. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AN UPPER-LEVEL TROUGH...ACCOMPANIED BY A SECONDARY COLD FRONT AND STRONG PRESSURE SURGE/COLD ADVECTION WILL MOVE THROUGH THE AREA TO BEGIN THE WEEKEND. THE BOUNDARY LOOKS MOISTURE STARVED...SO ANY ISOLATED SHOWER ACTIVITY WOULD REMAIN CONFINED TO AREAS ALONG THE MASON-DIXON LINE CLOSEST TO THE FORCING FROM THE SHORTWAVE TROUGH SATURDAY. THUS SLIGHT CHANCE POPS HAVE BEEN CONFINED TO THESE AREAS. AT THE MOMENT...THE MEDIUM RANGE GUIDANCE HAS COME INTO BETTER WITH THE TIMING AND STRENGTH OF THE FRONT. STRONG AND GUSTY WINDS ARE APPEARING INCREASINGLY LIKELY FOR SATURDAY...ESPECIALLY CONSIDERING THE STRONGEST WINDS ACCOMPANYING THE PRESSURE SURGE WILL OCCUR DURING PEAK HEATING WHEN LAPSE RATES ARE STEEPEST AND MIXING DOWN HIGHER WIND GUSTS WOULD BE EASIEST. WINDS DIMINISH SATURDAY NIGHT INTO SUNDAY MORNING AS AN AREA OF HIGH PRESSURE NOSES OVER THE REGION...BUT ITS STAY OVER OUR AREA IS SHORT-LIVED AS A LARGE AND SLOW-MOVING AREA OF LOW PRESSURE APPROACH FROM THE WEST BRINGING A RETURN TO UNSETTLED WEATHER EARLY NEXT WEEK. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
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VFR CONDS THROUGH TAF PERIOD NOW THAT SHOWER AND THUNDERSTORM ACTIVITY HAS MOVED EAST. NWLY FLOW INCREASES BEHIND THE COLD FRONT TONIGHT...WITH 30 KT GUSTS THROUGH WEDNESDAY. GUSTY NW FLOW CONTINUES WED NIGHT INTO THURSDAY. HIGH PRESSURE MOVES INTO THE REGION LATE THURSDAY BEFORE MOVING OFF THE COAST AHEAD OF A WEAK COLD FRONT THURSDAY NIGHT. SHOWERS MAY CROSS THE TERMINALS FRIDAY. MODERATE CONFIDENCE IN VFR CONDITIONS AND WESTERLY WINDS AROUND 10 KNOTS FRIDAY NIGHT...WITH MODERATE CONFIDENCE IN WINDS INCREASING TO BETWEEN 15 AND 20 KNOTS WITH GUSTS UP TO 30 KNOTS DURING THE DAY SATURDAY.
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&& .MARINE...
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SCA REMAINS IN EFFECT FOR THE WATERS THRU TNGT WITH NWLY FLOW INCREASING TO 25 TO 30 KT THROUGH THE OVERNIGHT BEHIND THE COLD FRONT. A GALE WARNING IS IN EFFECT WEDNESDAY FOR ALL OF THE WATERS WITH GUSTS TO AROUND 35 KT EXPECTED DURING THE DAY. THE GALE WARNING MAY BE ABLE TO BE DOWNGRADING SOMETIME DURING THE AFTN AS THE PRESSURE GRADIENT AND ASSOCIATED WIND FIELD WEAKENS A BIT. NORTHWEST WINDS WILL CONTINUE ON THE WATERS WEDNESDAY NIGHT AND THURSDAY WITH AN SCA IN EFFECT FOR ALL WATERS THROUGH THAT TIME. HIGH PRESSURE MOVES INTO THE REGION LATE THURSDAY AND THURSDAY NIGHT. SOUTHERLY FLOW WILL INCREASE ACROSS THE WATERS FRIDAY. A PERIOD OF HIGH-END SMALL CRAFT ARE EXPECTED BEHIND A STRONG BUT MOISTURE-STARVED COLD FRONT SATURDAY. WINDS DIMINISH THROUGH THE NIGHT SATURDAY AND LIKELY DROP BELOW SMALL CRAFT LEVELS DURING THE DAY SUNDAY.
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&& .FIRE WEATHER...
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A COLD FRONT WILL CONTINUE TO PASS THROUGH THE AREA THIS EVENING AND GUSTY NORTHWEST WINDS ARE EXPECTED BEHIND THE COLD FRONT WEDNESDAY. A DEEP MIXING LAYER WILL ALLOW FOR DRIER AIR TO MIX DOWN...CAUSING LOW RELATIVE HUMIDITY VALUES DURING THE LATE MORNING THROUGH THE AFTERNOON. THE COMBINATION OF GUSTY WINDS...LOW FUEL MOISTURE AND LOW RELATIVE HUMIDITY WILL ENHANCE THE THREAT FOR THE SPREAD OF WILDFIRES WEDNESDAY. AFTER COORDINATION WITH STATE OFFICIALS AND SURROUNDING WFOS...A FIRE WEATHER WATCH WAS ISSUED.
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&& .TIDES/COASTAL FLOODING...
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POSITIVE TIDAL ANOMALIES REMAIN STEADY AROUND THREE-QUARTERS OF A FOOT THIS EVENING. NWLY WITHIN THE NEXT FEW HRS WILL CAUSE ANOMALIES TO DECREASE TO ABOUT HALF A FOOT BELOW MLLW. GUSTY NORTHWEST WINDS WILL DEVELOP TONIGHT AND CONTINUE THROUGH WEDNESDAY. BLOWOUT TIDES ARE EXPECTED WEDNESDAY.
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&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR DCZ001. MD...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR MDZ003>007-009>011-013-014-016>018-502. VA...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR VAZ025>031-036>040-042-050>057-501-502-504. WV...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR WVZ050>053-055-502-504-506. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ530>543. SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO 6 AM EDT THURSDAY FOR ANZ530>534-537>543. GALE WARNING FROM 6 AM TO 6 PM EDT WEDNESDAY FOR ANZ530>543. SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO MIDNIGHT EDT WEDNESDAY NIGHT FOR ANZ535-536. && $$ SYNOPSIS...BAJ/JRK NEAR TERM...BAJ/JRK SHORT TERM...HAS LONG TERM...DFH AVIATION...BAJ/JRK/HAS/DFH MARINE...BAJ/JRK/HAS/DFH FIRE WEATHER... TIDES/COASTAL FLOODING...

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