Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 050933 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 533 AM EDT SUN JUL 5 2015 .SYNOPSIS... A STATIONARY FRONT WILL REMAIN OVER THE CAROLINAS THIS MORNING AS WEAK HIGH PRESSURE CENTERED OVER PENNSYLVANIA SHIFTS EAST. THE FRONT WILL LIFT NORTH INTO THE AREA AS A WARM FRONT MONDAY. A WEAK COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY...THEN STALL AND SLOWLY DISSIPATE. && .NEAR TERM /THROUGH TONIGHT/... EXPANDED DENSE FOG ADVISORY PER LATEST OBS. TRAFFIC CAMS SUGGEST THE FOG IS MORE PATCHY THAN AREAS. SUNRISE IS BY 6AM...SO THE HEADLINE IS EXPECTED TO BE CANCELLED WELL BEFORE THE CURRENT EXPIRY TIME OF 10AM. AS OF 09Z...1019MB SFC HIGH OVER SRN PA WITH AN UPR LOW APPARENT OVER THE TN VLY IN WATER VAPOR IMAGERY. HIGH CLOUDS AHEAD OF THE LOW HAVE OVERSPREAD THE AREA RIDING A 60 KT W-SWLY JET STREAM. THE HIGH CLOUDS AND SOME MIXING ELY/SELY FLOW HAVE LIMITED FOG DEVELOPMENT TO MORE OF A PATCHY COVERAGE FOR WRN BALT-WASH SUBURBS AND NORTH-CENTRAL VA. TODAY...HIGH PRESSURE SHIFTS EAST FROM PA LATE THIS MORNING. HIGH CLOUDS INCREASE IN COVERAGE AND THICKEN A BIT AS THE UPR LOW DRIFTS TOWARD THE AREA. SUBTROPICAL MOISTURE PLUME SHIFTS INTO THE SWRN ZONES LATER THIS MORNING WITH POPS INCREASING IN ELY FLOW. HOWEVER...THE HIGH CLOUDS WILL LIMIT INSOLATION AND THUS THE INSTABILITY. EXPECT SHOWERS AND THUNDERSTORMS IN AT LEAST SCATTERED COVERAGE THIS AFTERNOON INTO THE OVERNIGHT. UPR LOW DRIFTS TO THE CNTRL APPALACHIANS THROUGH TONIGHT WITH LWX IN THE WARM SECTOR WITH THE ASSOCIATED WARM FRONT OVER THE AREA...PROVIDING CONVERGENT FORCING. POPS ROUGHLY INCREASE AND SPREAD NE OVER THE CWA THIS AFTERNOON INTO TONIGHT...WITH A RAINY PERIOD THIS EVENING TO MONDAY EVENING FOR MOST OF THE CWA. WITH LIMITED INSTABILITY...EXPECT MAINLY ISOLATED TO SCATTERED THUNDERSTORM COVERAGE. && .SHORT TERM /MONDAY/... MONDAY...SOME RISK FOR SEVERE WEATHER EAST FROM THE BLUE RIDGE AS UPR LOW IS ANCHORED OVER THE ALLEGHENIES. LIMITED INSTABILITY SHOULD EVENTUALLY RESULT IN A MARGINAL RISK...THOUGH IT IS NOT OFFICIALLY ONE IN THE DAY 2 OUTLOOK FROM SPC. WIDESPREAD RAIN WITH EMBEDDED THUNDERSTORMS EXPECTED. HEAVY RAIN THREAT ALSO WITH PWATS AROUND 2 INCH. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... LOW PRESSURE WILL LIFT OUT MONDAY NIGHT. THUNDERSTORMS RESULTING FROM IT COULD LINGER INTO TUE IF THE LOW IS SLOW...BUT NOT EXPECTING THAT AT THIS TIME AND HAVE MINIMIZED POPS FOR TUE DUE TO SUBSIDENCE BEHIND THE LOW. THE NEXT WEAK FRONT MOVES INTO THE REGION WED...BUT ONLY CHANCE POPS ON WED WITH THAT. WITH THE FRONT STALLING AND WASHING OUT THU THRU SAT...MAINLY SLIGHT CHANCE POPS DURING THAT PERIOD. TEMPS WILL BE PRETTY STAGNANT THRU THE PERIOD...ONLY WAVERING A FEW DEGREES FROM DAY TO DAY. TYPICAL JULY WEATHER IN THE MID ATLANTIC. && .AVIATION /10Z SUNDAY THROUGH THURSDAY/... FOG EXPECTED TO DEVELOP LATE TONIGHT INTO THE MORNING FOR MUCH OF THE AREA. HOWEVER...LIGHT MIXING AND HIGH CLOUDS HAVE KEPT CONDS MVFR FOR NOW...WILL CONTINUE TO MONITOR. HIGH CLOUDS THICKEN TONIGHT WITH RAIN AND EMBEDDED TSTMS SHIFT NORTH ACROSS THE TERMINALS THIS EVENING THROUGH TONIGHT. RAINY TONIGHT INTO MONDAY EVENING ACROSS THE AREA WITH IFR CONDS POSSIBLE IN HEAVIEST ACTIVITY. OTHER THAN TSTMS...NO AVIATION CONCERNS TUE THRU SATURDAY. WINDS LIGHT...BELOW 10 KT. && .MARINE... LIGHT ELY FLOW TODAY AS HIGH PRESSURE SHIFTS EAST FROM PA. SELY FLOW AROUND 10 KT TONIGHT...SHIFTING S MONDAY. SLY CHANNELING POSSIBLE BY LATE MONDAY AFTERNOON. WILL NEED TO WATCH FOR SRN MD WATER SCA TOWARD MONDAY EVENING. OTHER THAN TSTMS...NO MARINE CONCERNS TUE THROUGH SATURDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR MDZ004>006- 503-505-507. VA...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR VAZ026-027- 029-030-037>040-050>053-055>057-501-502-505-506. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...BAJ/CAS NEAR TERM...BAJ SHORT TERM...BAJ LONG TERM...CAS AVIATION...BAJ/CAS MARINE...BAJ/CAS

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