Area Forecast Discussion
Issued by NWS Sterling, VA

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179 FXUS61 KLWX 171458 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 1058 AM EDT Sun Jul 17 2016 .SYNOPSIS... A surface trough will remain over the region through tonight. A front will approach the area Monday before passing through the area Monday night and Tuesday. High pressure will return for Wednesday and Thursday before moving off the coast late in the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Mostly sunny and seasonably hot summer day expected across the region today as high pressure builds in overhead and remnant frontal boundary continues to dissipate. Mostly sunny skies aside from fair weather cumulus and a few cirrus will be the rule. Can`t rule out a rogue shower or storm, but keeping with a dry forecast for all locations for now as drier air works in and atmosphere will be largely capped. High temperatures will range from the upper 80s to low 90s. With dew points in the 60s, and even some 50s west, heat indices should peak in the mid 90s and below.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... Quiet weather expected tonight with mostly clear skies and lows generally 60s to mid 70s. Forecast becomes a little more unclear for the Monday to Tuesday time period as next frontal system approaches the area. May have a decaying MCS moving towards the region early Monday. While not expecting any direct impacts from it, its evolution may play a role in any convection Monday, in the form of convective debris clouds and any outflow boundaries for future convective development. Timing differences also exist between major model guidance, but general idea is for initial boundary to move across the area late Monday night/early Tuesday morning (not ideal for convection), with main frontal passage later Tuesday. For now, will keep POPs relatively low on Monday, aside from the western higher terrain, with lack of apparent significant forcing and slow return of surface moisture. Will concentrate the highest POPs for most of the region Monday night as first boundary approaches. Southern Maryland and central Virginia then see the greatest precipitation chances on Tuesday, with less further north as drier air begins to work in. High temperatures will be hottest Monday in the low to mid 90s, and then mid 80s to low 90s on Tuesday. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Weak high pressure will build in the area behind a cold front for Wednesday and Thursday. Seasonably warm conditions are expected during this time and humidity will be a bit lower. The high will shift offshore and weaken Friday while a cold front moves through the central Conus. A southwest flow will allow for the return of more hot and humid conditions. A cold front will approach the area next weekend. Confidence in how far south the front will make it is low...but given a strong subtropical ridge to our south the latest forecast will lean toward the front dissipating or stalling out nearby. This means that hot and humid conditions are likely for next weekend along with possible popup thunderstorms. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/...
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VFR and dry conditions through this evening. Some patchy fog possible again Monday morning, but coverage will be much less than this morning. Next chance of showers/thunderstorms will arrive Monday afternoon through Tuesday with next frontal system. VFR conditions are expected most of the time Wednesday through Thursday with high pressure overhead.
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&& .MARINE... Sub-SCA conditions expected today across all waters. Southerly flow increases tonight and into Monday with near-SCA conditions possible at times, however will leave below 18 knots at this time. Greatest risk of SCA will occur Monday night out ahead of next frontal system. Isolated to scattered showers/thunderstorms also possible Monday into Tuesday. High pressure will settle overhead for Wednesday and Thursday. The high will weaken and shift offshore Friday while a cold front moves through the central CONUS. A south to southwest flow will develop during this time. Winds should remain below SCA criteria Wednesday through Friday...but gusts may be close to 20 knots Friday with the gradient strengthening a bit between the cold front well to our west and High pressure out in the Atlantic. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...BJL NEAR TERM...MM/RCM SHORT TERM...MM LONG TERM...BJL AVIATION...BJL/MM/RCM MARINE...BJL/MM/RCM is the U.S. government's official web portal to all federal, state and local government web resources and services.