Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 100108 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 908 PM EDT WED APR 9 2014 .SYNOPSIS...
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HIGH PRESSURE WILL BUILD OVERHEAD TONIGHT BEFORE MOVING OFF THE COAST THURSDAY. A COLD FRONT WILL STALL OUT OVER THE AREA FRIDAY AND A WAVE OF LOW PRESSURE WILL RIDE ALONG THE BOUNDARY...PASSING THROUGH OUR AREA FRIDAY NIGHT. HIGH PRESSURE WILL RETURN FOR SATURDAY BEFORE MOVING OFF THE COAST EARLY NEXT WEEK.
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&& .NEAR TERM /THROUGH THURSDAY/...
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HIGH PRESSURE WILL BUILD OVERHEAD TONIGHT. DRY AND SEASONABLY CHILLY CONDITIONS ARE EXPECTED TONIGHT. THE HIGH WILL MOVE OFF THE COAST THURSDAY AND A RETURN FLOW FROM THE SOUTHWEST WILL DEVELOP. THE SOUTHWEST WIND WILL COMBINE WITH PLENTY OF SUNSHINE TO USHER IN WARMER CONDITIONS. IT WILL BE BREEZY DURING THE AFTERNOON DUE TO A DEEP MIXING LAYER AND TIGHTENING PRESSURE GRADIENT BETWEEN HIGH PRESSURE OFF THE COAST AND A COLD FRONT MOVING INTO THE OHIO VALLEY. SOUTHWEST WINDS WILL GUST AROUND 20 TO 30 MPH THURSDAY AFTERNOON. MAX TEMPS WILL RANGE FROM THE 50S IN THE MOUNTAINS TO THE LOWER AND MID 70S IN THE WASHINGTON METROPOLITAN AREA AS WELL AS CENTRAL VIRGINIA. A BAY BREEZE WILL KEEP TEMPS A BIT COOLER ALONG THE WESTERN SHORE...WITH MAX TEMPS GENERALLY IN THE 60S.
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&& .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... SOUTHWEST 50 KT LOW LEVEL JET DEVELOPS OVERHEAD THURSDAY NIGHT AHEAD OF APPROACHING TRAILING COLD FRONT ASSOCIATED WITH UPPER LOW OVER HUDSON BAY. THIS FRONT LOSES MOMENTUM AND STALLS OVER THE REGION FRIDAY/FRIDAY NIGHT. LOW PRESSURE DEVELOPS AND TRAVERSES THE FRONT FRIDAY INTO FRIDAY NIGHT WITH SHORT WAVE IN FLOW ALOFT. SOME INSTABILITY IS PRESENT BOTH NORTH OF THE SURFACE FRONT ACROSS E WV/NORTHERN MD AND SOUTH OF THE SURFACE FRONT WHERE MLCAPES OF A COUPLE HUNDRED J/KG ARE PRESENT FRIDAY AFTERNOON. HAVE INTRODUCED A SCHC OF THUNDER ACCORDINGLY. FORECAST SOUNDINGS SHOW A THIN CAPE PROFILE ALTHOUGH DEEP MIXING SOUTH OF THE FRONT COULD RESULT IN SOME GUSTY WINDS WITH ANY SHOWERS/TSTMS. SOUNDING PROFILES ARE MORE STABLE NORTH OF THE FRONT. AS SHORT WAVE EXITS ENE SATURDAY...THERMAL RIDGE BEGINS TO BUILD ONCE AGAIN WITH WARM AIR ADVECTION. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
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A STALLED FRONT WILL MOVE NORTH AS A WARM FRONT SATURDAY NIGHT. ISOLATED SHOWERS CANNOT BE RULED OUT ALONG AND AHEAD OF THE WARM FRONT SATURDAY NIGHT INTO EARLY SUNDAY. TEMPERATURES TO THE SOUTH OF THE FRONT SHOULD REACH THE MIDDLE TO UPPER 70S...WHILE TEMPERATURES TO THE NORTH OF THE FRONT WILL ABOUT 5 TO 10 DEGREES COOLER. DEWPOINT TEMPERATURES ARE EXPECTED TO BE IN THE 50S SATURDAY NIGHT INTO SUNDAY. A LOW PRESSURE SYSTEM WILL CONNECT TO THE WEST END OF THE WARM FRONT ACROSS THE LOWER GREAT LAKES SUNDAY INTO SUNDAY NIGHT BEFORE MOVING TO NEW ENGLAND SUNDAY NIGHT. IT IS PSBL THAT MON NGT/TUE COULD SEE A STRONG MOISTURE FLOW FM THE GULF CST TO NEW ENGLAND AS A COLD FRONT APRCHS THE AREA W/ A PTNL FOR A STRONG MOISTURE FETCH IN THE PRE-FRONTAL ENVIRONMENT. PD OF HVY RA IS PSBL. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON WEDNESDAY. COOLER TEMPERATURES ARE EXPECTED TUESDAY INTO WEDNESDAY.
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&& .AVIATION /01Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS ARE EXPECTED THROUGH THURSDAY. WINDS WILL BE LIGHT TONIGHT BEFORE SHIFTING TO THE SOUTHWEST AND GUSTING AROUND 20 TO 25 KNOTS THURSDAY AFTERNOON. AREAS OF MVFR RESTRICTIONS MAY BE PRESENT FRIDAY/FRIDAY NIGHT DUE TO SHOWERS AND POSSIBLE ISOLATED TSTMS ALONG A SLOW MOVING COLD FRONT. HIGH PRESSURE WILL BUILD OVER THE TERMINALS SATURDAY BEFORE MOVING OFF THE COAST SUNDAY. A SOUTHERLY FLOW WILL INCREASE AHEAD OF A COLD FRONT EARLY NEXT WEEK. && .MARINE... HIGH PRES WILL MOVE OFF THE COAST THURSDAY AND A RETURN FLOW FROM THE SOUTH WILL DEVELOP. A DEEP MIXING LAYER AND TIGHTENING PRESSURE GRADIENT WILL CAUSE THE POTENTIAL FOR GUSTY WINDS AROUND 20 TO 25 KNOTS. A SMALL CRAFT ADVISORY IS IN EFFECT THURSDAY AFTERNOON FOR THE NORTHERN PORTION OF THE MARYLAND CHESAPEAKE BAY AND THE UPPER TIDAL POTOMAC RIVER. FARTHER SOUTH...THE GRADIENT MAY NOT BE AS STRONG AND THE RELATIVELY COOLER WATERS MAY PREVENT THE DEEP MIXING LAYER FROM DEVELOPING. THEREFORE...WINDS HAVE BEEN CAPPED AROUND 15 KNOTS FOR NOW. SCA CONDITIONS ARE EXPECTED WITH SOUTHWEST WINDS THURSDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. SCA CONDITIONS MAY BE MET AGAIN AS WINDS INCREASE FRIDAY AFTERNOON SOUTH OF A COLD FRONT. HIGH PRESSURE WILL BUILD OVERHEAD SATURDAY BEFORE MOVING OFF THE COAST EARLY NEXT WEEK. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON THURSDAY TO 6 AM EDT FRIDAY FOR ANZ530>532-538>540. SMALL CRAFT ADVISORY FROM 6 PM THURSDAY TO 6 AM EDT FRIDAY FOR ANZ533-534-537-541>543. SMALL CRAFT ADVISORY FROM NOON TO 8 PM EDT THURSDAY FOR ANZ535- 536. && $$ UPDATE...WOODY! PRVS...BJL/AEB/KLW

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