Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 280132 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 932 PM EDT Mon Jun 27 2016 .SYNOPSIS...
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A surface trough will remain over the region through Tuesday, shifting east as a cold front late Tuesday. High pressure will build from the west through Wednesday, then Bermuda high pressure will provide a south wind Thursday and Friday. The next cold front crosses the area from the west Saturday, stalling over the southern Mid-Atlantic Sunday.
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&& .NEAR TERM /THROUGH TUESDAY/...
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As of 9pm, surface trough/cold front is stalling over central VA and southern MD. It will remain roughly there until an upper trough shifts across the area Tuesday. Scattered showers and thunderstorms, which persist along this boundary, will continue to shift northeast to southern MD through the rest of the evening before diminishing after midnight. As noted previously, some showers could linger through the night. Elsewhere, particularly in clearer skies behind the cold front in NWrn zones, patchy fog could develop. Lows upper 60s to low 70s with plenty of lingering moisture. Previous... Surface trough will remain over eastern portions of the area Tuesday morning, supporting at least isolated to scattered showers. Meanwhile, cold front will approach from the west with better mid-level height falls. Convection could activate along the front during the afternoon as it cross the Blue Ridge and enters a more moisture-rich environment. Deep layer shear is still moderate, but a little stronger than today, so would think there would be a better chance of isolated strong to severe storms. Weak mid-level lapse rates will be a limiting factor. With stronger flow, flooding should be less of a concern. Highs will reach the mid to upper 80s.
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&& .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
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Cold front will push east Tuesday night, clearing any remaining showers and storms. High pressure and drier air will build into the area Wednesday and Wednesday night; however, upper level troughing may result in some clouds. Temperatures and humidity will be a little lower. On Thursday, upper level troughing will persist, but low level flow will become more southerly. This may support enough moisture return to result in a few showers and storms, especially over the higher terrain. Temperatures may bump up a couple degrees.
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&& .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... The Mid-Atlantic region will be under the influence of an upper level trough late in the week. Southerly flow ahead of a cold front will continue through Friday, however temperatures will be near or below normal with max temps in the low to mid 80s. Showers and thunderstorms will be possible both days. The front will slowly move eastward Friday night into Saturday. An additional cold front will approach Saturday afternoon. Showers and thunderstorms are possible Saturday through Sunday. High pressure should build into the region behind the second front Sunday night into Monday. Showers may linger into Monday. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/...
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As of 01Z, a cold front is stalling over southern MD and central VA. No more TSRA threats for the TAF sites this evening. Skies are clearing behind the cold front with thick clouds along the frontal zone. Fog is possible late tonight, most likely NW where clearing will last longest. Maintained MVFR conds in 00Z TAFs except for KCHO which is most climatologically prone for fog. Scattered thunderstorms will develop along a cold front Tuesday afternoon. DC/Baltimore the mostly likely affected area. There is a better chance some of these storms could be strong. Generally VFR with high pressure from late Tuesday night through Thursday morning. Showers/storms may develop mainly SW of the metros Thursday afternoon. Sub-VFR conditions possible Thursday night-Saturday in SHRA/TSRA.
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&& .MARINE...
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Southerly channeling on southern MD waters ahead of a stalled cold front over northern section of the Bay and Tidal Potomac. Local gusty showers possible rest of the evening. Behind the front early Wednesday, westerly winds may also be close to SCA levels. With high pressure to the north, sub- SCA conditions are expected Wednesday night- Thursday night. Sub-SCA southerly winds expected on the waters Friday-Saturday.
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&& .HYDROLOGY...
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Heavy thunderstorms have tapered off/shifted southeast with the cold front which is stalling over the central VA piedmont and southern MD. locally heavy rain in showers/isolated thunderstorms likely through the rest of the evening, but nothing that warrants a flash flood watch.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until 2 AM EDT Tuesday for ANZ532-533-537- 540-541. Small Craft Advisory until 6 AM EDT Tuesday for ANZ534-543.
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&& $$ SYNOPSIS...BAJ/ADS NEAR TERM...BAJ/ADS SHORT TERM...ADS LONG TERM...HAS AVIATION...BAJ/ADS/HAS MARINE...BAJ/ADS/HAS HYDROLOGY...lwx

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