Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 121852 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 252 PM EDT Sat Aug 12 2017 .SYNOPSIS...
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A cold front will move through the area this evening and become stationary across the Carolinas early in the week. Weak high pressure builds over the area Sunday and holds through mid week.
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&& .NEAR TERM /THROUGH TONIGHT/...
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Cdfnt is currently moving through wrn PA and the OH river as seen on moisture discontinuity on 24-hr microphysics GOES-16 RGB. Air mass over the area ahead of front has destabilized after morning low clouds and fog with MLCAPE around 1000 J/kg. 0-6 km shear is respectable with around 45 kt, but appears limiting factor for severe storms is strongest forcing will remain north of the Mason-Dixon line. Nevertheless, expect nrms-widespread showers and sct thunderstorms as the front comes through later this evening with best chance of showers between 5PM-9PM. Activity will end from west to east after 8PM but linger through at least midnight in the southeast over srn St. Marys county. Definitely not expecting a repeat of last night. Some low clouds are possible over upslope areas overnight, otherwise lots of high clouds overnight.
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&& .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
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Weak high pressure will build over the area Sun and hold through the middle of the week. Low clouds and a few showers will be possible Sun night into Mon as sfc flow turns onshore but it will remain too stable for t-storms.
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&& .LONG TERM /TUESDAY THROUGH SATURDAY/...
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Upper shortwave/surface reflection should depart to the east of the area Tuesday, leading to a drying trend through the middle of next week as high pressure builds. Decent model agreement through mid week, which includes a stark warming trend by Thursday. Models then diverge on timing/orientation of the next upper level wave and surface front that would in theory bring the next chance of organized precip.
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&& .AVIATION /18Z SATURDAY THROUGH THURSDAY/...
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A brief t-storm is possible through 01Z tonight. Cdfnt then crosses the area with winds shifting and clouds scattering out. Mainly VFR Tue-Wed. Patchy fog possible Tue night in areas that receive rain if dry advection isn`t strong enough prior to nightfall. NW flow AOB 10 kts.
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&& .MARINE...
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Gusty showers and t-storms possible over the waters this evening. SMWs may be required. Cdfnt crosses the waters late this evening. Generally light winds expected mid-week as high pressure moves over the waters.
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&& .TIDES/COASTAL FLOODING...
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Minor coastal flooding possible at Straits Point early this evening.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...Coastal Flood Advisory until 8 PM EDT this evening for MDZ017. VA...None. WV...None. MARINE...None.
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&& $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...DFH AVIATION...LFR/DFH MARINE...LFR/DFH TIDES/COASTAL FLOODING...LFR

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