Area Forecast Discussion
Issued by NWS Sterling, VA

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947 FXUS61 KLWX 270116 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 916 PM EDT Tue Jul 26 2016 .SYNOPSIS... A front will remain stationary across the Mid-Atlantic region through the middle of the week. Low pressure will cross the region Thursday night into Friday. Another cold front will approach the area early next week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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Convection ongoing this evening out ahead of approaching shortwave and along weak remnant frontal boundary. Much of the thunderstorm activity, some severe, has been along south side of instability gradient where 1500-2000 J/KG remains this evening. Remnant of MCS in WV also progressing eastward this evening, but as it runs into increasingly stable air mass already worked over earlier this evening, expecting further weakening. Thus severe threat should be waning, but potential for heavy rain continues with precipitable water values 2-2.3 inches. While no significant flooding currently anticipated, will continue to monitor as some places have already received locally heavy amounts of rainfall earlier today. Shower/storm coverage should decrease overnight, but chances will continue through the night with the presence of a shortwave/surface reflection. Lows mainly in the 70s.
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&& .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... The front may move a little to the south Wednesday, but some storms will still be possible over southern portions of the area. The front will begin to lift back north Thursday and Thursday night as a surface low approaches. Flow will also strengthen aloft attendant to a short wave trough. There is still some spread in guidance, but there could be a severe and heavy rain threat depending on the low track. Temperatures will likely remain above normal. && .LONG TERM /FRIDAY THROUGH TUESDAY/... While timing differences remain, overall depiction among long-term guidance is for an unsettled weather pattern this weekend, as multiple impulses rotate through broad cyclonic flow aloft. This will help suppress temperatures back closer to normal, which will be a welcome relief after the elevated temperatures of earlier this week. However, even though we have been relatively dry across the area, multiple rounds of rainfall could create some Hydro issues, as moisture throughout the column will be plentiful. Cold front approaches the area Sunday into Monday and is then forecast to hang up just south of the area Monday and Tuesday. Current forecast has our area on the "cooler" (M/U80s) and drier side of the front Monday and Tuesday...with best precipitation chances generally in the southern portion of the forecast area. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
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Mainly VFR through the period, although chances for scattered showers and some thunderstorms exist through at least the first half of tonight (mainly CHO), and again on Wednesday. Low pressure crossing the area late Thursday may bring more widespread storms and rain with more prolonged sub- VFR conditions. Risk of showers and thunderstorms continues over the weekend, with warm and moist atmosphere remaining and several impulses moving through the upper-level flow.
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&& .MARINE...
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Primarily sub-SCA conditions expected. The main threat through Thursday night will come from thunderstorms producing gusty winds. This threat will greatest over the southern waters. Gradient winds will likely remain below 15 kt as a weak front is stalled across the area. Gradient winds remain sub-SCA Friday through the weekend, though higher winds and waves can be expected near thunderstorms.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...None. VA...None. WV...None. MARINE...None.
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&& $$ SYNOPSIS...ADS NEAR TERM...ADS/MM SHORT TERM...ADS LONG TERM...MSE AVIATION...ADS/MM/MSE MARINE...ADS/MM/MSE

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