Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 250748 CCA AFDLWX AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 346 AM EDT SAT OCT 25 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY. A REINFORCING COLD FRONT WILL PASS THROUGH THE REGION LATE TONIGHT INTO SUNDAY BEFORE HIGH PRESSURE RETURNS FOR MONDAY. THE HIGH WILL MOVE OFF THE COAST TUESDAY AND ANOTHER COLD FRONT WILL PASS THROUGH THE AREA WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/...
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BARELY A DROP OF RAIN ACROSS THE ENTIRE CONUS ATTM - OUTSIDE OF THE PAC NW AND FRINGE AREAS OF THE NRN GREAT LAKES AND NEW ENGLAND. THE JET STREAM IS HANGING JUST NORTH OF THE US/CANADA BORDER BUT WILL BRIEFLY SWING SOUTH OF THE BORDER TO CARRY THE NEXT SYSTEM. THIS FEATURE IS A FAST-MOVING CLIPPER THAT WILL QUICKLY MAKE THE JOURNEY FROM CNTRL CANADA TO THE GREAT LAKES OVER THE NEXT SEVERAL HRS. A CLOSED UPPER LEVEL LOW WILL GENERATE AS THE WAVE APPROACHES NRN NEW ENGLAND LATER TODAY. THE SFC LOW PRES SYSTEM WILL REMAIN GENERALLY UNDERNEATH THE UPPER LOW...NOT ALLOWING IT TO DEVELOP MUCH OF A MID-LAT CYCLONIC CHARACTER. SO NOT MUCH IN THE WAY OF PRECIP FOR THE SRN PERIPHERY OF THE SYSTEM THAT WILL BE THE CLOSEST TO THE MID-ATLC REGION. PLENTY OF COLD AIR LOCKED IN THE MID LEVELS OF THE UPPER WAVE BUT IT WILL BE CONCENTRATED FAIRLY CLOSE TO THE CENTER OF THE LOW... CREATING A GOOD HEIGHT GRADIENT BACK ACROSS THE UPPER MIDWEST. THIS WILL EVENTUALLY MEAN ANOTHER WINDY DAY FOR THE AREA ON SUNDAY BUT FOR TODAY...ANOTHER PLEASANT AUTUMN AFTN TODAY. CURRENT TEMPS ARE FAIRLY COOL BUT NOT TOO FAR BELOW AVG VALUES FOR THIS TIME OF THE YEAR AND ONLY BECAUSE DRY NW WINDS CONTINUE TO KEEP DEWPOINTS IN THE U30S. AFTER SUNRISE...DEWPOINTS WILL BE ON A SLIGHT REBOUND AS WINDS TURN MORE SWLY. TEMPS WILL MAKE THEIR WAY BACK INTO THE 60S BY LATE MRNG...TOPPING OUT JUST BELOW 70 BY MID AFTN W/ CLEAR SKIES AND ONLY A STEADY WLY BREEZE. USED AN EVEN BLEND OF BIAS-CORRECTED ADJMAV/MET TEMPS. LATER THIS EVE...THE SRN PERIPHERY OF THE UPPER LOW WILL BE ON THE NW DOORSTEP...SLIDING A DRY COLD FRONT ACROSS THE REGION OVERNIGHT. A HANDFUL OF LIGHT SHOWERS WILL LIKELY DISSIPATE UPON REACHING THE SPINE OF THE APLCNS W/ LITTLE MORE THAN SOME LEFTOVER MID CLOUDS TO MAKE IT PAST THE HIGHER TERRAIN. OVERNIGHT LOWS WILL BE MODERATE OVERNIGHT...AS DEWPOINTS ONLY DROP INTO THE M-U40S SO TEMPS WILL STAY IN THE U40S/L50S.
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&& .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
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AS THE DRY COLD FRONT SLIDES ACROSS THE REGION EARLY SUNDAY...THE RELATIVELY MOIST AIR AHEAD OF THE BOUNDARY WILL BE SWEPT OFF TO THE EAST AND REPLACED BY NOTICEABLY COLDER/DRIER AIR. SOLID NW WINDS WILL BE THE REASON...AS THE DEEP UPPER PARENT LOW DRIFTS ACROSS NEW ENGLAND AND OFF THE COAST...THE SUBSIDENCE REGION BEHIND IT WILL SWEEP THE AVERAGE CONDITIONS AND REPLACE IT W/ A DRY AND WINDY DAY. DESPITE THESE CONDITIONS...SFC TEMPS WILL STILL CLIMB BACK INTO THE U60S AND A FEW L70S. HIGH PRESSURE WILL BUILD OVERHEAD SUNDAY NIGHT...CAUSING WINDS TO DIMINISH. LIGHT WINDS...MAINLY CLEAR SKIES AND DRY CONDITIONS WILL PROVIDE A GOOD SETUP FOR RADIATIONAL COOLING. THEREFORE...MIN TEMPS SUNDAY NIGHT WILL BE CHILLY...ESPECIALLY IN SHELTERED VALLEYS AND RURAL AREAS. MIN TEMPS WILL RANGE FROM THE MID 30S IN PORTIONS OF THE SHENANDOAH VALLEY...EASTERN WEST VIRGINIA...NORTHERN MARYLAND AND THE NORTHERN AND WESTERN SUBURBS OF WASHINGTON/BALTIMORE...TO THE MID 40S IN DOWNTOWN WASHINGTON AND BALTIMORE. FROST IS POSSIBLE ACROSS MANY LOCATIONS LATE SUNDAY NIGHT AND EARLY MONDAY MORNING...ESPECIALLY NORTH AND WEST OF INTERSTATE 95. HIGH PRESSURE OVER THE REGION MONDAY MORNING WILL SHIFT TO THE COAST BY LATE IN THE DAY. A RETURN SOUTHERLY FLOW WILL DEVELOP...ALLOWING FOR MILDER CONDITIONS MONDAY AFTERNOON ALONG WITH PLENTY OF SUNSHINE. MAX TEMPS WILL RANGE FROM THE MID 60S ACROSS NORTHEASTERN MARYLAND TO THE MIDDLE 70S IN PORTIONS OF CENTRAL VIRGINIA. A SOUTHERLY FLOW WILL CONTINUE AROUND THE HIGH MONDAY NIGHT...ALLOWING FOR MILDER CONDITIONS COMPARED TO SUNDAY NIGHT. MIN TEMPS WILL RANGE FROM THE MID AND UPPER 40S ACROSS SHELTERED VALLEYS AND RURAL AREAS TO THE MIDDLE 50S IN DOWNTOWN WASHINGTON AND BALTIMORE.
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&& .LONG TERM /TUESDAY THROUGH FRIDAY/... A COLD FRONT WILL APPROACH FROM THE WEST TUESDAY...BUT IT WILL REMAIN TO OUR WEST AND A SOUTHWEST FLOW AHEAD OF THIS SYSTEM WILL USHER IN UNUSUALLY WARM CONDITIONS FOR THIS TIME OF YEAR. MAX TEMPS WILL APPROACH 80 DEGREES ACROSS MANY LOCATIONS. THE COLD FRONT WILL MOVE INTO WESTERN PORTIONS OF OUR CWA TUESDAY NIGHT. CLOUDS WILL INCREASE AHEAD OF THIS SYSTEM AND THERE MAY EVEN BE A FEW SHOWERS LATE ACROSS THE POTOMAC HIGHLANDS...BUT PRECIPITATION AMOUNTS WILL BE LIGHT. THE COLD FRONT WILL MOVE THROUGH THE AREA WEDNESDAY INTO WEDNESDAY NIGHT...BRINGING THE CHANCE FOR SHOWERS. PRECIPITATION AMOUNTS WILL BE LIGHT SINCE LITTLE MOISTURE WILL BE ASSOCIATED WITH THE FRONT. HIGH PRESSURE WILL BUILD OVERHEAD FOR LATE IN THE WEEK...BRINGING A RETURN OF MORE SEASONABLE CONDITIONS. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
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VFR CONDS THRU THE CURRENT TAF PERIOD. QUIET HIGH PRES TODAY W/ JUST A FEW PASSING CLOUDS AND A LIGHT SW WIND THIS AFTN. WINDS AGAIN BECOME THE CONCERN SUNDAY...AS SFC AND LOW LEVEL WINDS REACH THE 15-25KT RANGE RANGE - LOCALLY HIGHER. A COLD FRONT WILL USHER-IN THIS NEW WINDY DAY EARLY SUN...W/ GUSTS CONTAINING UNTIL LATER THIS EVE. VFR CONDITIONS ARE EXPECTED MOST OF THE TIME SUNDAY NIGHT THROUGH WEDNESDAY. A SOUTHERLY FLOW WILL INCREASE AHEAD OF A COLD FRONT MONDAY AND TUESDAY. WINDS WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT FOR WEDNESDAY.
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&& .MARINE...
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A FEW 10-15KT GUSTS OVERNIGHT AS THE EVEN THE LAND AREAS CONTINUE TO SHOW WINDS OUT OF THE NW - WHICH HAS BEEN FAIRLY CONSISTENT FOR THE PAST FEW DAYS. AT LEAST A CHANGING TREND IN STORE TO HEAD INTO EARLY NEXT WEEK. HIGH PRESSURE WILL BUMP UP WINDS AGAIN THIS AFTN BUT ONLY IN THE 5-10KT RANGE AND OUT OF THE SSW. A QUICK-MOVING COLD FRONT WILL BE THE PRECURSOR TO ANOTHER WINDY DAY ON SUNDAY. A SCA UP FOR ALL THE WATERS STARTING JUST A COUPLE OF HRS AFT SUNRISE AND LASTING THRU THE EVE. HIGH PRESSURE OVER THE WATERS SUNDAY NIGHT WILL MOVE OFF THE COAST MONDAY THROUGH TUESDAY. A SOUTHERLY FLOW WILL DEVELOP DURING THIS TIME. A COLD FRONT WILL PASS THROUGH THE WATERS WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS TUESDAY AND WEDNESDAY. HIGH PRESSURE WILL RETURN FOR LATE IN THE WEEK.
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&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM EDT SUNDAY FOR ANZ530>543. && $$ SYNOPSIS...BJL NEAR TERM...GMS SHORT TERM...BJL/GMS LONG TERM...BJL/GMS AVIATION...BJL/GMS MARINE...BJL/GMS

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