Area Forecast Discussion
Issued by NWS Sterling, VA

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874 FXUS61 KLWX 090218 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 918 PM EST Thu Dec 8 2016 .SYNOPSIS...
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High pressure will build east from the Great Plains through Saturday before moving off the Mid-Atlantic coast Sunday morning. A cold front crosses the area Monday followed by a reinforcing cold front Wednesday.
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&& .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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As of 9pm, a 1050mb surface high is centered over the NErn corner of Alberta. A surface ridge extends from there all they way to the central Mid-Atlantic; underneath a broad upper trough. This high center will build over the area trough Saturday (though it will only be 1034mb or so by then). West to northwest winds became gusty this afternoon and have increased since. A few gusts of 35 to 40 mph gusts have been reported; mainly over the northern third of the CWA. A 47 mph gust occurred at 8:30pm at KW99 (Petersburg, WV). This looks to be isolated, so a wind advisory is not anticipated at this time. However, it will remain breezy overnight due to cold air advection. Upslope snow showers are very light right now; half to one inch accumulation overnight west of the Allegheny Front. Mid- level clouds are producing virga over west- central Maryland this evening and should continue to for a few more hours. Flurries possible at higher elevations. Minima primarily in the mid 20s...around 30 in the cities...teens in the Highlands.
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&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... High pressure to be in control of the weather Friday-Saturday night. Temps will be several degrees below normal (Mid 40s/upper 20s). East of I-95 will struggle to reach 40...35-40 west of I-95 to the Highlands...20s in the Highlands. Wind chills will make it feel more like 25-30 in most locales. Snow showers expected to continue in the Highlands through at least Friday night. A cold Friday night with lows in the 20s everywhere except the colder Highlands. Highs Saturday will be quite similar to Friday. High pressure will settle over the region Saturday night providing good radiational cooling conditions. Lows primarily in the lower to mid 20s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Surface high pressure overhead Sunday will move offshore as a southerly flow builds over our region. A weakening upper level shortwave could bring precipitation north of the area, but cannot rule out precipitation reaching out over the CWA. If it does, temperatures may be cold enough, mainly at higher elevations, to see some type of frozen precipitation... but there is still uncertainty on this. Warm front moves over our area Sunday night, bringing a chance of precipitation as a low pressure moves from the Mid-West into the Great Lakes. Wintry precipitation possible as temperatures may be near or below freezing in some areas before the warm front moves through. The low will continue its track northeast and push a cold front over our region Monday into Tuesday... with rain more likely ahead of the front. Conditions will be drying Tuesday into Tuesday night. Guidance disagrees for Wednesday and Thursday with GFS bringing another cold front on Wednesday, increasing the chance of precipitation over our area... then dry conditions on Thursday. The Euro is drier with a couple of disturbances bringing a chance of precipitation to the area. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/...
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VFR expected tonight through Saturday night. Strong NW winds with gusts 25 to 30 kt through midnight and again Friday. Mainly dry/VFR conditions on Sunday as high pressure moves offshore. Upper level disturbance and frontal boundary could bring some precipitation to our region Sunday into Monday... with some sub-VFR periods. Drier expected conditions Tuesday.
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&& .MARINE...
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Raised a Gale Warning for north of North Beach, MD and the upper tidal Potomac River through tonight per observations. Strongest gusts over the waters through midnight. Mainly 25 to 30kt tonight and Friday. SCA rest of the waters and all waters Friday as of now. SCA slowly diminishes through Friday night. High pressure builds overhead through Saturday with marginal SCA risk for the morning with continued west to northwest winds. Mainly dry conditions on Sunday as high pressure moves offshore. Upper level disturbance and frontal boundary could bring some precipitation Sunday into Monday. Dryer conditions expected Tuesday. Small craft advisory may be needed Sunday and Monday afternoons.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from 6 AM Friday to 6 AM EST Saturday for ANZ531-532-539-540. Gale Warning until 6 AM EST Friday for ANZ530>532-535-538>540. Small Craft Advisory from 6 AM Friday to midnight EST Friday night for ANZ530-538. Small Craft Advisory until midnight EST Friday night for ANZ536-542. Small Craft Advisory until 6 AM EST Saturday for ANZ533-534- 537-541-543. Small Craft Advisory from 6 AM to 6 PM EST Friday for ANZ535.
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&& $$ Update...Jackson Previous...Woody!/IMR

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