Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 200125 AAA AFDLWX Area Forecast Discussion...UPDATED National Weather Service Baltimore MD/Washington DC 925 PM EDT Sat Aug 19 2017 .SYNOPSIS... Weak high pressure will build in today...but an upper-level disturbance and reinforcing cold front will pass through the area this evening. High pressure will build overhead late tonight through Sunday before moving offshore Monday. High pressure will remain offshore Tuesday and a stronger cold front will pass through Wednesday. High pressure returns for the second half of the week. && .NEAR TERM /THROUGH SUNDAY/... Scattered showers and isolated thunderstorms will continue for the next couple of hours until upper level trof passes over the area around midnight. Gust front well out ahead of the showers with common gusts 25 to 30 mph behind it. Skies become clear quickly after midnight. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... High pressure will move off the coast by Monday morning. Southerly flow will increase resulting in the return of warm and humid conditions. Westerly flow aloft will lead to the potential upper level disturbances to pass across the Mid-Atlantic region. A CU field will likely develop by afternoon and showers and thunderstorms are possible. At this time...disorganized activity is expected through the afternoon and early evening. Any convection will likely wane Monday night resulting in mild and dry conditions. && .LONG TERM /TUESDAY THROUGH SATURDAY/... A cold front is expected to move into the Ohio Valley Tuesday afternoon. This will present a chance of thunderstorms across teh northern part of our forecast area by mid/late afternoon, and across the entire region Tuesday night as the front moves into PA. The chance should persist through at least midday Wednesday. Ahead of the front east of the mountains highs Tuesday will reach the 90 degree mark, with lows in the lower to mid 70s. Wednesday highs should drop back into the 80s. High pressure will decend out of the upper Great Lakes and bring some very pleasant weather to the region for the second half of the week. Lows Thursday and Friday night will drop into the 50s west of the mountains, and lower 60s east. Highs Thursday through Saturday around 80. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... VFR conditions are expected most of the time through Wednesday. An isolated shower or thunderstorm is possible late this afternoon and evening across the northern terminals...but most areas will be dry. Patchy fog cannot be ruled out early Sunday morning. Scattered thunderstorms are possible later Monday into Monday night as a southerly flow allow for more atmospheric moisture to return. A cold front is expected to move into PA Tuesday night...and cross the Bay midday Wednesday. Thunderstorms/sub-VFR weather will be possible during this time. VFR conditions to end the day Wednesday. && .MARINE... A reinforcing cold front will pass through the waters this evening. A pop up shower cannot be ruled out but most areas will be dry. High pressure will build overhead for Sunday before moving offshore Monday. A return southerly flow will develop Monday and persist through Tuesday night ahead of a cold front. A cold front is expected to push through the waters by midday Wednesday. Showers and thunderstorms will be possible beginning late Tuesday afternoon. Wind gusts may reach SCA levels Tuesday and Wednesday. && .TIDES/COASTAL FLOODING... Waters may rise to minor levels at Annapolis Monday. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ Update...LFR Products...HSK/WOODY!

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