Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 242057 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 457 PM EDT Mon Oct 24 2016 .SYNOPSIS... High pressure over the region through midweek. A cold front will cross the area Thursday afternoon and evening. High pressure returns Friday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Temperatures have warmed to the mid 60s over much of the area...mid 70s in the central Shenandoah Valley. Winds should drop off after sunset allowing for good radiational cooling conditions. This will cause a rapid cooling tonight...possibly into the lower 30s in Highland and Pendleton counties. Because of this we issued a freeze warning for these counties. This will be the final one of the season for these counties as growing season is considered over on the 25th. To the immediate north and east of this area we have issued a frost advisory. East of the Blue Ridge lows will be in the 40s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... High pressure over the region Tuesday through Wednesday. Highs will be 55-60 over the majority of the area. The coldest night of the week is expected to be Tuesday night. High pressure will be settled over the Mid Atlantic. Portions of eastern WV are forecasted to drop into the lower 30s. Given latest trends...decided to issue a freeze watch for northern and western zones. A frost advisory may be needed for much of the remainder of the forecast area. If freezing conditions indeed occur across the current freeze warning area...this portion of the freeze watch will likely be cancelled as the growing season will have ended. Of note is that for the far western zones, the growing season should have ended nearly two weeks ago. Given this, regardless of whether freezing temperatures occur by Wednesday morning, the growing season will be declared over in these areas on Wednesday afternoon. Further east, for the majority of the CWA, the growing season still has another week before it is considered late and two additional weeks before it is so far overdue as to be considered over regardless. Wednesday temperatures will again rise to 55-60. Lows Wednesday night around 40. && .LONG TERM /THURSDAY THROUGH MONDAY/... A mid/upper level shortwave trough and associated surface low/frontal system will traverse the area Thursday. Although the shortwave aloft is pretty stout, the majority of the forcing passes to the north. In addition, there is not much opportunity for moisture return. So while there will likely be scattered showers around, precipitation amounts may average pretty light and confined mainly to northern portions of the CWA. Breezy conditions behind the front will usher in a renewal of cool temperatures for the end of the week. Another wave of low pressure may pass to the north of the area over the weekend leading to a similar outcome (a brief period of milder temperatures, scattered showers then breezy and cooler conditions). && .AVIATION /21Z MONDAY THROUGH SATURDAY/... VFR conditions expected tonight through Wednesday night. Mainly VFR Thursday into Friday. A few showers are possible Thursday as low pressure passes to the north but restrictions should be minimal. Southwesterly winds of 10 to 15 knots Thursday will become northwesterly Thursday night into Friday. && .MARINE... Small craft advisory has been of marginal values and primarily over the Bay. The upper Potomac portion will drop off this evening. Will leave remainder of the overnight portion intact for now but would not be surprised to see further reductions in the SCA by following shifts. Gusts could resume again after mid morning Tuesday. A tightening gradient between high pressure to the southeast and low pressure passing to the north will likely result in winds to Small Craft Advisory levels Thursday. Gusty winds will likely persist in a northwesterly pressure surge following the passage of low pressure to the north Thursday night into Friday. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Freeze Watch from late Tuesday night through Wednesday morning for MDZ003>006-501-502-507. VA...Freeze Watch from late Tuesday night through Wednesday morning for VAZ026>031-503-504. Freeze Warning from 3 AM to 9 AM EDT Tuesday for VAZ503-504. Frost Advisory from 3 AM to 9 AM EDT Tuesday for VAZ025>027- 029. WV...Freeze Watch from late Tuesday night through Wednesday morning for WVZ050>053-055-501>506. Freeze Warning from 3 AM to 9 AM EDT Tuesday for WVZ505-506. Frost Advisory from 3 AM to 9 AM EDT Tuesday for WVZ055-501- 502. MARINE...Small Craft Advisory until 6 PM EDT Tuesday for ANZ530>534- 537>543. Small Craft Advisory until midnight EDT tonight for ANZ535-536. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE... is the U.S. government's official web portal to all federal, state and local government web resources and services.