Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 280301 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 1001 PM EST Sun Nov 27 2016 .SYNOPSIS... High pressure will crest overhead this afternoon and tonight, then move offshore on Monday. Upper energy from a large low pressure system over the upper midwest will move into the region Monday night and Tuesday, followed by a deepening surface low that moves across the area Wednesday night through Thursday. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... High pressure will remain over the region tonight. High clouds will increase well ahead of a storm system over the central CONUS...but current thinking is that the cloud deck should be thin enough for radiational cooling. Therefore...bumped the temps down a few degrees in rural areas and sheltered Valleys. Min temps will range from the lower and middle 20s in the colder valleys and rural areas to the upper 30s in downtown Washington and Baltimore. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... Increasingly active weather then expected as the week progresses. Strengthening low pressure center across the central US Monday will eventually weaken, fill, and slowly move eastward into the Great Lakes Tuesday and into Wednesday. This will slowly push a frontal zone towards the region, with strong southerly flow out ahead of it, bringing with it milder and wetter conditions. Will see a continued increase and thickening of the cloud deck on Monday. Light and variable winds in the morning will give way to a developing southerly flow. Highs by the afternoon reach the 50s area-wide. A strong push of warm air advection and energy aloft will then make the move towards the region Monday night and into Tuesday. Winds at 850 mb increase markedly and by Tuesday morning reach 60 knots. While not expected to reach the surface at most locations, gusts up to 50 mph are possible across the higher elevations of the Allegheny and Blue Ridge Mountains, and a Wind Advisory may be needed. Rain showers will overspread the region during the overnight hours and into the day on Tuesday. Mixing may increase a bit during the day on Tuesday as well, so breezy conditions likely for most locations during the day. Lows Monday night in the 40s climb into the 60s on Tuesday. There looks to be a lull in the action Tuesday night, with a lower chance of rain showers. Should be a mild night with lows not dropping out of the 50s in many locations. Will also likely be areas of fog with lingering low level moisture and moist and mild air aloft. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... A storm system is expected to develop along the tail-end of a cold front over the interior Southeast U.S. Wednesday morning. The storm should ride northeast along the front Wednesday and Wednesday night, bringing more rain showers to the region. Temperatures will be on the warm side of things with a gusty breeze. The storm system will continue to move northeastward toward southern New England Thursday. High pressure will build in behind the storm and its associated cold front Thursday and Thursday night. Drier and colder air will filter into the region. An upper level trough of low pressure is expected to sag southward into the region from the Eastern Great Lakes Thursday night and Friday. There may not be a lot of moisture available to fuel any showers with the trough. Plus, a downsloping flow over the Appalachian Mountains could encourage a dry day Friday. However, higher elevations in the Appalachians could encounter a couple of snow showers Friday into Friday night. High pressure will build in behind the trough of low pressure Saturday and Sunday. Dry and chilly conditions expected each day. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... VFR and tranquil flying conditions expected through Monday increasing cirrus overnight and into Monday morning. Light and variable winds tonight also give way to a developing southerly flow on Monday. Conditions will deteriorate Monday night and into Tuesday as rain overspreads the region bringing periods of MVFR and IFR. With increasing low level wind field, low level wind shear is also expected. Some brief improvement is likely Tuesday afternoon along with breezy southerly flow, with additional low ceilings/visibilities possible Tuesday night in fog/stratus. IFR to LIFR conditions expected due to rain showers Wednesday and Wednesday night. Winds southeast to south around 10 knots with higher gusts Wednesday. Winds south becoming west around 10 knots Wednesday night. && .MARINE...
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Winds will diminish tonight with high pressure building overhead. A southerly flow will develop Monday as high pressure moves off to our east. Winds will increase Monday afternoon with gusts around 20 knots expected. A Small Craft Advisory is in effect for the waters Monday afternoon. The SCA continues continues for Monday night. The strongest period of winds is expected Tuesday, when a Gale Warning may become necessary. Winds will then decrease somewhat Tuesday night. Small craft advisories likely Wednesday. Winds southerly 10 to 15 knots with gusts in excess of 20 knots Wednesday. Small craft advisories possible Wednesday night as well with winds shifting to the west and gusting to 20 knots Wednesday night.
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&& .TIDES/COASTAL FLOODING... Monday through Wednesday will feature a strong southerly fetch up the bay coupled with a new moon and deepening low pressure. Will continue to monitor the potential for coastal flooding. && .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from noon Monday to 6 AM EST Tuesday for ANZ530>543.
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&& $$ SYNOPSIS...MM NEAR TERM...BJL/MM SHORT TERM...MM LONG TERM...KLW AVIATION...BJL/MM/KLW MARINE...BJL/ADS/MM/KLW TIDES/COASTAL FLOODING...MM

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