Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 021939 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 339 PM EDT THU JUL 2 2015 .SYNOPSIS... A STATIONARY FRONT WILL REMAIN OVER CENTRAL VIRGINIA AND SOUTHERN MARYLAND THROUGH THE WEEKEND. SEVERAL WAVES OF LOW PRESSURE WILL MOVE EAST ALONG THE FRONT AS AN ACTIVE PATTERN CONTINUES. HIGH PRESSURE WILL RETURN FOR THE FIRST HALF OF NEXT WEEK. && .NEAR TERM /THROUGH FRIDAY/... QUASI-STATIONARY BOUNDARY APPEARS TO BE LOCATED AT THE FAR SOUTHERN EXTENT OF THE CWA...IF NOT FARTHER...WITH A WEAK SFC LOW OVER THE CHESAPEAKE BAY. THE FRONT WILL SERVE AS THE CONDUIT OF UNSETTLED WEATHER THROUGH THE UPCOMING WEEKEND. IN THE NEAR TERM...WIDESPREAD SHOWERS ARE LOCATED AHEAD OF A VORT MAX IN THE OHIO VALLEY. THESE WILL SKIRT SOUTHERN AREAS THROUGH THE REMAINDER OF THE AFTERNOON. VERY LITTLE INSTBY HAS BUILT WITH EXTENSIVE CLOUD COVER AND THEREFORE EXPECT THUNDER TO BE RATHER LIMITED IN OUR CWA. ORANGE-ST. MARYS SEEING A FEW SUN BREAKS AND ON NORTHERN EDGE OF INSTBY GRADIENT...SO PERHAPS A LITTLE HIGHER CHANCE THERE. FARTHER NORTH...SHOWER ACTIVITY WILL BE ISOLATED/SCATTERED. EXPECT SOME DOWNTURN TO SHOWER ACTIVITY AFTER THE VORT MAX PASSES THIS EVENING. HOWEVER...SCATTERED SHOWERS WILL REMAIN POSSIBLE WITH THE FRONT IN THE VICINITY THROUGH THE NIGHT. DID NOT WANT TO GO COMPLETELY DRY AS ANY IMPULSE COULD SPARK A SHOWER IN THE MOIST ENVIRONMENT...HOWEVER IT/S PLAUSIBLE THE NORTHERN HALF TO TWO-THIRDS OF THE AREA COULD BE DRY. SOME PATCHY FOG MAY DEVELOP BUT AT THIS TIME DOES NOT APPEAR TO BE DENSE. OVERNIGHT LOWS WILL REMAIN MILD...WITH LOWER 60S NORTHWEST TO AROUND 70 SE. A WAVE OF LOW PRESSURE WILL TRACK EAST ALONG THE STALLED FRONT ON FRIDAY...IN ADDITION TO POTENTIAL MID-LEVEL DISTURBANCES ROTATING OUT OF A DEEPENING TROUGH OVER THE OHIO VALLEY. EXPECT SHOWERS TO INCREASE IN COVERAGE FROM SW TO NE FROM MORNING INTO THE AFTERNOON. A LITTLE QUESTIONABLE HOW FAR NORTH THE ACTIVITY GETS AND WHETHER IT WILL BE IN ONE SLUG OR THE OFF/ON VARIETY. THEREFORE HAVE A GRADIENT OF POPS FROM 40 TO 80 NE TO SW...BUT THESE MAY NEED TO BE RAISED. WE WILL LIKELY BE ON THE STABLE SIDE OF THE BOUNDARY...SO THUNDER SHOULD BE RATHER LIMITED...ESPECIALLY WITH NORTHWARD EXTENT. THINK THAT THE RAIN WILL FALL AT A SLOW ENOUGH RATE TO LIMIT A FLOOD THREAT...BUT WITH A MOIST ATMOSPHERE AND WET SOILS...THIS WILL NEED TO BE MONITORED. WENT ON COOL SIDE OF GUIDANCE FOR HIGHS WITH CLOUDS/PRECIP...WITH MOST LOCATIONS IN THE 70S. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... FRONTAL BOUNDARY WILL REMAIN JUST SOUTH OF THE REGION WITH WAVES OF LOW PRESSURE RIDING NORTHWARD ALONG THE BOUNDARY. SHOWERS WILL REMAIN IN THE FORECAST FRIDAY NIGHT AND INTO THE 4TH OF JULY HOLIDAY. WINDS WILL LIKELY REMAIN OUT OF THE EAST OR NORTHEAST WHICH WILL KEEP THE ATMOSPHERE COOLER AND MORE STABLE. HAVE REMOVED MENTION OF THUNDERSTORMS FROM THE FORECAST ATTM. HIGH TEMPERATURES WILL LIKELY ONLY REACH THE MIDDLE TO UPPER 70S DURING SATURDAY WITH LOWS IN THE 60S. && .LONG TERM /SUNDAY THROUGH THURSDAY/... FRONTAL BOUNDARY SOUTH OF THE AREA DRIFTS FARTHER SOUTH SUNDAY AND MONDAY AS UPR RIDGE BUILDS EAST OVER THE MIDWEST. ANY ISOLATED TO POSSIBLY SCATTERED THUNDERSTORMS BOTH DAY LOOK TO BE DIURNALLY DRIVEN. BY TUESDAY FRONT RETURNS TO AREA AND A COASTAL LOW DEVELOPS OFF DELMARVA IN RESPONSE TO UPPER LEVEL TROUGH. INCREASING CHANCE OF CONVECTIVE DEVELOPMENT ESPECIALLY OVER EASTERN MD AND VA TIDEWATER. NEXT COLD FRONT APPROACHES REGION FROM THE MIDWEST WEDNESDAY AND SLOWS WITH MORE ACTIVE WEATHER INTO LATE NEXT WEEK. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... AN UNSETTLED FORECAST IS EXPECTED THROUGH FRIDAY DUE TO A STALLED FRONT ACROSS SOUTHERN VA. CHO HAS THE HIGHEST CHANCE OF SEEING MULTIPLE ROUNDS OF SHOWERS THROUGH THE PERIOD...WITH MORE UNCERTAIN COVERAGE FOR THE METRO TERMINALS. ANY PERIOD OF STEADIER RAIN COULD BRING MVFR OR POSSIBLY IFR CONDITIONS. TOUGH TO TIME THESE OUT NOW. THE MOST NUMEROUS COVERAGE IS EXPECTED FRIDAY AFTERNOON. THERE IS A LIMITED CHANCE OF THUNDER DURING THE AFTERNOON HOURS. IN ADDITION...FOG AND/OR LOW CIGS MAY DEVELOP TONIGHT INTO FRIDAY MORNING. GENERALLY HAVE MVFR CONDITIONS INDICATED...BUT IFR IS POSSIBLE. LIGHT WINDS EXPECTED FROM THE N/E QUADRANT. OVERCAST CONDITIONS ALONG WITH A CHANCE FOR SHOWERS WILL PERSIST SATURDAY AND PERHAPS INTO SUNDAY. CONDITIONS WILL LIELY IMPROVE LATER SUNDAY AND INTO EARLY NEXT WEEK. && .MARINE... FRONT STALLED SOUTH OF THE AREA THROUGH FRIDAY. SUB-SCA CONDITIONS LIKELY. HOWEVER BY LATE FRIDAY AFTERNOON...LOW PRESSURE WILL TRACK ALONG THE FRONT AND MAY INCREASE EASTERLY WINDS OVER THE SOUTHERN PARTS OF THE WATERS. PERIODS OF SHOWERS WILL CROSS THE WATERS. THEIR MAIN IMPACT WILL BE TO REDUCE VSBY...BUT EMBEDDED THUNDERSTORMS COULD ALSO BRING GUSTIER WINDS. EXPECT THESE TO BE ISOLATED...RELEGATED TO AFTERNOON/EVENING HOURS...AND MOST LIKELY OVER SOUTHERN PARTS OF THE WATERS. WINDS ARE EXPECTED TO REMAIN BELOW SCA LEVELS SATURDAY INTO MONDAY. OCCASIONAL SHOWERS COULD IMPACT THE WATERS DURING THIS TIME BUT THE THREAT FOR THUNDERSTORMS IS LOW. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...KRW NEAR TERM...ADS SHORT TERM...KRW LONG TERM...CEM AVIATION...ADS/KRW MARINE...BAJ/ADS/KRW

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