Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 261854 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 254 PM EDT TUE AUG 26 2014 .SYNOPSIS...
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HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH TONIGHT THEN WEAKEN WEDNESDAY AHEAD OF A COLD FRONT THAT WILL CROSS FROM THE NORTHWEST LATE WEDNESDAY. HIGH PRESSURE WILL CROSS THE NORTHERN MID-ATLANTIC THURSDAY NIGHT AND RESIDE OFFSHORE OVER THE WEEKEND. THE NEXT COLD FRONT WILL APPROACH THE MID-ATLANTIC EARLY NEXT WEEK.
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&& .NEAR TERM /THROUGH WEDNESDAY NIGHT/...
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AS OF 18Z...1022MB SFC HIGH IS CENTERED FROM SERN PA TO NRN WV. ELY/NELY FLOW CONTINUES EAST OF THE BLUE RIDGE. JUST A FEW FAIR CU OUT THERE WITH TEMPS RISING INTO THE MID TO UPR 80S. TONIGHT...SIMILAR VALLEY FOG SETUP. MIN TEMPS GENERALLY A FEW DEGREES HIGHER THAN LAST WITH DEWPOINTS UP A BIT...LOW TO MID 50S WEST OF THE BLUE RIDGE AND LOW TO MID 60S EAST. WEDNESDAY...WEAKENING COLD FRONT (CURRENTLY CAUSING STRONG STORMS IN NRN IN/SRN MI) REACHES THE NORTHWEST ZONES LATE MORNING. MAX TEMPS LOW 90S AND DEWPOINTS IN THE LOW TO MID 60S ALLOW 1000 J/KG MLCAPE (ACCORDING TO 09Z SREF). SCATTERED THUNDERSTORMS THAT DIE AS THEY DOWNSLOPE AND GET STRUNG OUT FROM THE WEAKENING FRONT. I-95 WAS A GOOD DISCRIMINATOR FOR POP/NO POP AS OF NOW. SHOULD ORGANIZED ACTIVITY GET GOING THE BALT-WASH METRO COULD SEE SOME THUNDERSTORMS WEDNESDAY EVENING. DIURNAL TREND IN ACTIVITY WITH THE COLD FRONT ALSO DISSIPATING OVERNIGHT. FOG SHOULD FORM PARTICULARLY WHERE RAIN FALLS AS CLOUDS GENERALLY CLEAR BY LATE IN THE NIGHT. MIN TEMPS GENERALLY LOW TO MID 60S.
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&& .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
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THURSDAY...LIGHT NWLY FLOW AS SFC HIGH BUILDS IN FROM THE GREAT LAKES. MAX TEMPS MID TO UPR 80S WITH AMPLE SUNSHINE. OVERRUNNING MID/HIGH CLOUDS ENTER FROM THE WEST DURING THE AFTERNOON. NLY FLOW SHOULD LIMIT FOG THURSDAY NIGHT. MIN TEMPS MID 50S NW TO LOW 60S SE (MID 60S URBAN).
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&& .LONG TERM /FRIDAY THROUGH TUESDAY/...
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HIGH PRESSURE OVER THE NORTHEAST WILL MIGRATE OFF THE COAST THROUGH THE DAY ON FRIDAY...CAUSING SURFACE WINDS TO BACK FROM EASTERLY TO SOUTHERLY AND SIGNALING THE RETURN OF WARMER AND MORE HUMID CONDITIONS FOR THE WEEKEND. HIGHS ON FRIDAY WILL BE IN THE LOWER TO MID 80S...INCREASING TO THE UPPER 80S TO LOWER 90S SATURDAY AND SUNDAY. UPPER LEVEL SUBTROPICAL HIGH PRESSURE OVER THE SOUTHEAST COAST SHOULD SUPPRESS ANY CONVECTION...KEEPING CONDITIONS DRY WITH ONLY FAIR WEATHER CUMULUS CLOUDS TO PROVIDE BREAKS FROM THE SUN FRIDAY AND SATURDAY. SUNDAY MAY SEE SOME THUNDERSTORMS IN THE EVENING AS THE UPPER LEVEL RIDGE WEAKENS AND MOVES SOUTH AND AN APPROACHING SHORTWAVE ASSISTS IN DESTABILIZING THE ATMOSPHERE. CONVECTION SHOULD REMAIN SCATTERED AND SEVERE CONVECTION IS NOT ANTICIPATED AT THIS POINT AS CAPE VALUES WILL MAX OUT AROUND 1000 J/KG. AN UPPER LEVEL SHORTWAVE TROUGH WILL DRAG SURFACE LOW PRESSURE ACROSS THE GREAT LAKES AND NORTHEASTWARD TOWARD NEW ENGLAND SUNDAY NIGHT AND MONDAY. THE ASSOCIATED COLD FRONT WILL BEGIN TO BRING RAIN TO THE AREA SUNDAY NIGHT. A SHORTWAVE/VORT MAX IS CURRENTLY PROGGED TO PASS NEAR THE NORTHWESTERN PORTION OF THE CWA...LEADING TO ENHANCED POPS IN THAT AREA SUNDAY NIGHT AND MONDAY MORNING . MONDAY SHOULD BE WET FOR MOST OF THE AREA AS THE FRONT MOVES OVER THE AREA AND STALLS. LOWEST POPS WILL BE FOUND ACROSS SOUTHERN MARYLAND...AS THE SURFACE BOUNDARY MAY STALL BEFORE IT REACHES THAT FAR SOUTHEAST. THE STALLED FRONT WILL CONTINUE TO BRING SHOWERS AND THUNDERSTORMS TO THE MID-ATLANTIC MONDAY NIGHT AND TUESDAY...AND ADDITIONAL PERIODS OF ENHANCE RAINFALL MAY OCCUR TUESDAY AS ANOTHER SHORT WAVE MAY CROSS THE FRONT. TEMPS FOR THE EARLY PART OF NEXT WORKWEEK SHOULD BE NEAR NORMAL...IN THE MID 80S.
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&& .AVIATION /19Z TUESDAY THROUGH SUNDAY/...
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HIGH PRESSURE/VFR INTO WEDNESDAY OUTSIDE OF MORNING VALLEY FOG. WEAK COLD FRONT CROSSES LATE WEDNESDAY NIGHT WITH SCT TSRA WEST OF BALT-WASH CORRIDOR. VFR/HIGH PRESSURE RETURNS THURSDAY WITH LIGHT NWLY FLOW. CONFIDENCE IS LOW IN THE OCCURRENCE OF ANY HAZARDS TO AVIATION IN THE LONG TERM.
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&& .MARINE...
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LIGHT NLY FLOW THIS AFTERNOON BECOMES ELY THIS EVENING. WEAK COLD FRONT CROSSES THE WATERS WEDNESDAY NIGHT. THUNDERSTORMS ARE EXPECTED TO DIE OUT BEFORE THE REACH THE WATERS AS OF THIS TIME. LIGHT NWLY FLOW THURSDAY AS HIGH PRESSURE BUILDS FROM THE GREAT LAKES. A SMALL CRAFT ADVISORY MAY BE NECESSARY SUNDAY IN BREEZY PREFRONTAL SOUTHERLY FLOW.
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&& .TIDES/COASTAL FLOODING...
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WATER LEVELS STILL HALF TO TWO THIRDS FOOT ABOVE NORMAL IN SPITE OF LIGHT NLY FLOW. FLOW BECOMES ELY AGAIN TONIGHT...SO WATER LEVELS WILL REMAIN ELEVATED. HOWEVER....NO MINOR FLOODING IS EXPECTED OVER THE NEXT FEW DAYS AS OF NOW.
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&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...BAJ NEAR TERM...BAJ SHORT TERM...BAJ LONG TERM...CEB AVIATION...BAJ/CEB MARINE...BAJ/CEB TIDES/COASTAL FLOODING...BAJ

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