Area Forecast Discussion
Issued by NWS Sterling, VA

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459 FXUS61 KLWX 260107 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 907 PM EDT Thu May 25 2017 .SYNOPSIS... Low pressure and associated cold front will move through the area this evening. Weak high pressure will return to the area later Friday and Friday night before moving off the coast Saturday. A warm front will stall out overhead later Saturday through Sunday. A stronger cold front will pass through the area Monday. && .NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
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Cutoff low that produced the widespread showers/thunderstorms this afternoon/evening now pushing eastward, and coverage/intensity of the activity will continue to decline during the remainder of the evening. Will see westerly flow increase behind the departing system, so some upslope rain showers likely overnight into Friday morning. Otherwise, for the rest of the area, drying conditions likely, with even some breaks in the clouds developing. There may also be some patchy fog develop in areas that can decouple. Temperatures not going to fall much more, generally holding or falling slightly into the 50s.
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&& .SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... Low pressure will continue to move away from the area Friday while high pressure approaches from the west. A west to northwest flow will usher in seasonable conditions...but it will be breeze due to a tight gradient between the departing low and building high. An isolated shower cannot be ruled out from daytime heating...but much of the time will be dry. Weak high pressure will build overhead Friday night before moving off off the coast Saturday. A warm front will stall out over the area later Saturday through Saturday night. Marine air will allow for cooler conditions across northeastern portions of the CWA while much warmer and more humid conditions are expected across central and western areas behind the boundary. There is still some uncertainty as to exactly where the boundary will setup. However...with warm and humid conditions in place showers and thunderstorms will likely develop. Sufficient shear suggests that some storms could be severe...mainly along and south/west of the boundary. Convection should dissipate in coverage later Saturday night due to the loss of daytime heating. && .LONG TERM /SUNDAY THROUGH THURSDAY/... A warm front will settle near/over our CWA Sunday before a cold front moves across late Sunday night into Monday morning. Showers and thunderstorms possible with periods of heavy rain during these days. Conditions start to dry out into Tuesday as westerly flow settles in. Another -weaker- front approaches on Tuesday night into Wednesday, increasing PoPs slightly. Several pieces of upper level energy could bring a chance of precip to our area Wednesday into Thursday, but looking into mostly dry conditions. High temperatures will be in the 70s and 80s... some 60s at higher elevations. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/...
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Showers and thunderstorms and their associated sub-VFR conditions and gusty winds are weakening and decreasing in coverage. This will lead to the return of primarily VFR conditions overnight. There may be some patchy fog around, but have kept out of the TAFs for now given increasing low level wind field. VFR conditions are expected most of the time Friday through Saturday night. West to northwest winds will gust around 20 to 25 knots Friday. A few showers and thunderstorms are possible Saturday. Some storms may become strong to severe during the afternoon and evening hours. Sub-VFR conditions expected Sunday into Monday with rounds of showers and thunderstorms moving through our region with a boundaries stalled/moving through. Conditions become drier/VFR Monday night into Tuesday.
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&& .MARINE...
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Showers/thunderstorms will decrease in coverage through the evening. A Small Craft Advisory is in effect for most of the waters tonight as westerly flow increases behind departing system. Gusts up to around 20 knots expected overnight. A Small Craft Advisory is in effect for all of the waters Friday due to gusty west to northwest winds expected behind departing low pressure. Winds will quickly diminish toward sunset. Weak high pressure will build overhead Friday night before moving offshore Saturday. A warm front will stall out near the waters later Saturday through Saturday night. Additional showers and thunderstorms are possible during this time...especially Saturday afternoon and evening.
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&& .TIDES/COASTAL FLOODING...
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Combination of high astronomical tides due to a new moon and onshore flow will result in minor coastal flooding near times of high tide through tonight for most areas and into Friday morning for sensitive areas. Coastal Flood Headlines are in effect during this time. Tidal anomalies should decrease rapidly later Friday due to strengthening west to northwest flow.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...Coastal Flood Advisory until 11 PM EDT this evening for DCZ001. MD...Coastal Flood Advisory until 10 AM EDT Friday for MDZ014-018. Coastal Flood Advisory from 4 AM to 10 AM EDT Friday for MDZ011. Coastal Flood Advisory until 6 AM EDT Friday for MDZ017. VA...Coastal Flood Advisory until 11 PM EDT this evening for VAZ054. WV...None. MARINE...Small Craft Advisory until 6 PM EDT Friday for ANZ530>534- 536>543. Small Craft Advisory from 6 AM to 6 PM EDT Friday for ANZ535.
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&& $$ SYNOPSIS...BJL NEAR TERM...BJL/MM SHORT TERM...BJL LONG TERM...IMR AVIATION...BJL/MM/IMR MARINE...BJL/MM/IMR TIDES/COASTAL FLOODING...BJL/MM

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