Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 211853 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 253 PM EDT Sun Aug 21 2016 .SYNOPSIS...
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A cold front will continue to move east across the area into this evening. High pressure then builds over the area into Tuesday before persisting offshore through the rest of the week.
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&& .NEAR TERM /THROUGH TONIGHT/...
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As of 2pm, prefrontal line of scattered heavy showers with isolated thunderstorms has developed from Baltimore to Nelson Co VA. The actual front is seen as a line of showers in central WV. The prefrontal line will continue to move east from the Blue Ridge and north-central MD through the rest of the afternoon. These cells will continue to develop with lightning activity increasing from MLCAPE 1500 j/kg and effective shear around 30 kt. Gusty winds can be expected from these cores with localized damaging winds. Heavy rates of 1-2 inches per hour. The line orientation is nearly parallel to the mean flow, so some cells have been training. Will need to continue to look out for localized flash flooding. Cold front will shift east across the area through the early evening. NWly flow behind the front will gust around 20 mph overnight. Min temps low to mid 60s with mixing flow keeping fog limited to sheltered valleys.
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&& .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
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1027mb surface high pressure shifts overhead through Monday night. Cool and dry high pressure with max temps Monday and Tuesday low 80s with min temps Monday and Tuesday night generally low 60s, slightly less Monday night in the calm under the high pressure center. Light onshore flow Tuesday becomes southerly Tuesday night as the high sets up along the northern Mid-Atlantic coast.
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&& .LONG TERM /WEDNESDAY THROUGH SUNDAY/...
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High pressure will move offshore during the middle of the week leading to a warming trend in temperatures and increasing humidity. A strong middle to upper level ridge will build over the interior southeastern United States late in the week and persist into the weekend. Meanwhile, a cold front will drop into the area from the northwest on Friday then stall and weaken near or just south of the area. This will lead to an increased chance for showers and thunderstorms.
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&& .AVIATION /18Z SUNDAY THROUGH FRIDAY/...
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Gusty showers and thunderstorm across DC metros shift east through the rest of the afternoon. Cold front crosses from the west through the early evening. NWly flow gusts 20 kt overnight. VFR as high pressure builds through Monday night and persists offshore through the middle of next week. VFR continues Wednesday into Thursday with southeasterly winds at or below 10 knots.
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&& .MARINE...
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Special marine warnings expected rest of the afternoon as gusty showers and thunderstorms shift east through the area ahead of a cold front. Small craft advisory for 20 kt southerly gusts ahead of the front and then for NWly 25 kt gusts tonight behind the cold front. Winds ease through Monday morning with high pressure building overhead Tuesday morning for a dry and tranquil period which continues into the midweek. Southeasterly flow around high pressure departing to the east of the waters may result in gusts close to Small Craft Advisory levels Wednesday into Thursday.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...Coastal Flood Advisory from 6 PM to 11 PM EDT this evening for MDZ014. Coastal Flood Advisory until 8 PM EDT this evening for MDZ017. VA...None. WV...None. MARINE...Small Craft Advisory until noon EDT Monday for ANZ530>534- 537>543. Small Craft Advisory until 10 AM EDT Monday for ANZ535-536.
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&& $$ SYNOPSIS...BAJ NEAR TERM...BAJ SHORT TERM...BAJ LONG TERM...HTS AVIATION...BAJ/HTS MARINE...BAJ/HTS

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