Area Forecast Discussion
Issued by NWS Sterling, VA

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179 FXUS61 KLWX 151916 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 216 PM EST Sun Jan 15 2017 .SYNOPSIS...
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High pressure will build over the area through tonight. A stationary front over the southern mid-Atlantic states will move north as a warm front Tuesday. A weak cold front will push through the area Wednesday.
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&& .NEAR TERM /THROUGH MONDAY/...
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Developing warm air advection pattern and upslope precip late tonight will lead to some precip mainly over the southern half of the fcst area. Main concern for any freezing precip would be over the Blue Ridge mtns (i.e. Skyline Drive) where very hi-res guidance mainly the NCAR 3km 10-member WRF-ARW Ensemble and NAM-WRF 3-km parallel runs show sfc temps dropping below freezing. Current temps in those areas are in the 37-39F deg range. Given very marginal sfc temps and only light precip amounts, we`ll not issue any fzra advzy for those areas attm, but conditions will need to be monitored. Farther north, where sfc temps are likely to drop below freezing, no precip is expected. Forcing wanes during the day Monday with only spotty precip with any fzra ending as temps rise abv freezing. Otherwise, plenty of low clouds under weakening sfc wedge.
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&& .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
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Late Mon night, deeper moisture begins to spread the area from the west as a storm system tracks from Kansas City to Chicago. Rain appears likely everywhere late Mon night through Tue as a warm front lifts through the area. Very mild Tue evening ahead of cdfnt with temps in the 50s. Cdfnt clears the area around 12Z Wed.
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&& .LONG TERM /WEDNESDAY THROUGH SUNDAY/...
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A cold front will move across the region as the low pressure system pushes across northern New England Wednesday into Wednesday night. The chance for rain may linger Wednesday, but then should taper off with partial clearing, cooler temperatures, and perhaps some upslope snow showers in the higher elevations of the Appalachians. High pressure should build across the region Thursday and Thursday night before moving offshore the eastern U.S. Coast by Friday. Drier conditions with seasonable to mild temperatures are anticipated each period. A warm front should work its way northward up the Appalachian Front later Friday into Friday night, bringing a chance for a few rain showers. During the day Saturday, a second warm front could work its way northward toward the region. Even milder air and the chance for rain showers exist with this warm front as well. How far north this warm front gets will depend on the strength of an area of high pressure over New England. This high could try to wedge itself southward into our region. By Sunday, the high should weaken just enough to allow for a low pressure system over the Southeast U.S. to slide northeastward toward the mid-Atlantic. Due to the lack of cold air, any precipitation should be in the form of rain.
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&& .AVIATION /19Z SUNDAY THROUGH FRIDAY/...
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Thickening mid-high level clouds tonight with IFR conditions in -RA at KCHO. MVFR cigs at all other TAF sites Mon with no precip. Better chances of rain area wide late Mon night through Tue with passage of warm front. Mvfr conditions Wednesday into Wednesday evening. Winds west 5 to 10 knots Wednesday, becoming northwest 5 knots Wednesday night.
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&& .MARINE...
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Winds will diminish through Monday and begin to strengthen on Tue. SCA conditions possible Tue afternoon through Wednesday. No marine hazards Wed night through Fri.
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&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...KLW AVIATION...LFR/KLW MARINE...LFR/KLW

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