Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 310154 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 954 PM EDT SUN AUG 30 2015 .SYNOPSIS... HIGH PRESSURE WILL REMAIN ANCHORED OFFSHORE THROUGH MONDAY BEFORE HIGH PRESSURE RECENTERS OVER THE CENTRAL APPALACHIANS AND PERSISTS LATE INTO THE WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... HIGH CLOUDS PERSIST OVER THE AREA THIS EVENING. SCATTERED LINE OF SHOWERS HAS CONTINUED OVER THE POTOMAC HIGHLANDS. THESE SLOW MOVING CELLS ARE PRODUCING RAIN RATES OF HALF TO AN INCH PER HOUR. THIS ACTIVITY WILL CONTINUE GIVEN CONTINUED MOISTURE ADVECTION FROM SLY FLOW. OTHER ISOLATED SHOWERS MAY DEVELOP THROUGH THE OVERNIGHT...THOUGH GENERALLY WEST FROM THE BLUE RIDGE. MIN TEMPS GENERALLY U60S/L70S. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... HIGH PRESSURE STILL OFFSHORE WITH SLY FLOW ADVECTION IN MOISTURE. HIGHS WL AGN RANGE FM THE M80S TO THE L90S. SCATTERED TSTMS PSBL IN TERRAIN THROUGH THE AFTN. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... SHEARED OUT VORT MAX MAY LINGER OVER THE AREA MONDAY EVENING...SO LINGERED SLIGHT CHANCE POPS OF A SHOWER OVER THE SOUTHERN QUARTER OR SO OF THE CWA UNTIL MIDNIGHT. OTHERWISE EXPECT GRADUALLY CLEARING SKIES. LOWS IN MOST AREAS MID TO UPPER 60S...WITH 70S URBAN CENTERS AND NEAR SHORE. MAIN STORY TUESDAY WILL BE THE HEAT AS MID AND UPPER LEVEL RIDGING BUILD OVER THE EASTERN CONUS. LOWER ELEVATION LOCATIONS HAVE AT LEAST A CHANCE OF HITTING 90...WITH MID 90S POSSIBLE IN THE URBAN CORRIDOR. PROGGED DEW POINTS IN THE MID TO PERHAPS UPPER 60S WILL LIMIT HEAT INDICES TO A FEW DEGREES ABOVE AIR TEMPS. AS THE ATMOSPHERE APPEARS TO BE CAPPED...ONLY HAVE A SMALL CHANCE OF TERRAIN-BASED CONVECTION IN THE FAR WEST. WITH LITTLE CHANGE IN AIRMASS AND MOSTLY CLEAR SKIES...LOWS TUESDAY NIGHT SHOULD BE CLOSE TO PERSISTENCE. ON WEDNESDAY...A SHORTWAVE TROUGH ALOFT WILL BE ROUNDING THE RIDGE ALTHOUGH THERE ARE SOME TIMING DIFFERENCES AMONGST THE MODELS. MID- LEVEL LAPSE RATES WILL BE STEEPENING IN THE WEST...SO THERE WILL BE A BETTER CHANCE OF THUNDERSTORMS ALONG AND WEST OF THE BLUE RIDGE. UNCERTAIN AT THIS TIME HOW MUCH IF ANY ACTIVITY IS ABLE TO SPREAD TO THE EAST. HIGHS MAY BE SLIGHTLY LOWER THAN TUESDAY...ESPECIALLY IN THE WEST...BUT UPPER 80S-LOWER 90S WILL STILL BE SUPPORTED FOR MOST. SFC HIGH PRES DOMINATES THROUGH FRI BUT UPR LEVEL DISTURBANCES KEEP CHANCES OF AFTRN SHOWERS AND TSTMS EACH DAY... WITH HIGHER CHANCES WEST OF THE BLUE RIDGE. TEMPS WILL BE 5 TO 10 DEGREES ABOVE NORMAL BETWEEN THU AND FRI...M80S FOR THE WKND. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... VFR CONDS XPCTD THIS EVE THRU MON. ISOLATED SHOWERS AND THUNDERSTORMS GENERALLY WEST OF THE BLUE RIDGE. VFR CONDITIONS AND LIGHT WINDS PREVAIL A MAJORITY OF THE TIME MONDAY NIGHT THROUGH WEDNESDAY. ONLY EXCEPTION WILL BE POSSIBLE MORNING BR AT CHO/MRB. WEDNESDAY AFTERNOON WILL HAVE A SLIGHTLY HIGHER POSSIBILITY OF SCATTERED THUNDERSTORMS...ESPECIALLY CHO/MRB...WITH LESS CERTAINTY FOR THE METROS. VFR CONDITIONS EXPECTED WED NIGHT INTO THU. SOME SHOWERS AND TSTMS PSBL THU AFTN. && .MARINE... SLY CHANNELING HAS BEEN LESS THAN EXPECTED...BUT STILL SOME 18KT GUSTS. WILL CANCEL SOME OR ALL OF THE HEADLINE WITH THE 1030PM UPDATE. WINDS XPCTD TO RMN BLO SCA VALUES MONDAY WITH SWLY FLOW FROM HIGH OFFSHORE. WINDS MAY INCREASE WITH SOUTHERLY CHANNELING ON THE BAY MONDAY EVENING...BUT AT THIS TIME WILL LEAVE FORECAST AT 15 KT. GENERALLY LIGHT WINDS ARE THEN EXPECTED THROUGH WEDNESDAY AS HIGH PRESSURE DOMINATES. AN ISOLATED THUNDERSTORM MAY REACH THE WATERS WEDNESDAY AFTERNOON. SUB-SCA CONDITIONS EXPECTED FOR WED NIGHT INTO THU. SOME SHOWERS AND TSTMS PSBL THU AFTRN. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 3 AM EDT MONDAY FOR ANZ530>534-537- 539>541-543. && $$ UPDATE...JACKSON PREVIOUS...WOODY!/ADS/IMR

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