Area Forecast Discussion
Issued by NWS Sterling, VA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KLWX 161951 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 251 PM EST Thu Feb 16 2017 .SYNOPSIS... High pressure will build in overhead tonight and on Friday. A weak system will pass near the area Saturday night and Sunday. A backdoor cold front will be near the region on Monday followed by the return of high pressure. && .NEAR TERM /THROUGH TONIGHT/... Gusty northwest flow will continue through the remainder of the afternoon with gusts up into the 30-35 mph range. These will diminish heading into the evening and overnight hours as high pressure builds into the area. Still seeing plenty of strato- cumulus clouds out there, but these too will diminish relatively rapidly with the loss of daytime instability, becoming mostly clear by tonight. Much of the snow shower/flurry activity has also ended, but could still see a flurry or two through the rest of the afternoon across northern Maryland and back into West Virginia. Otherwise, the first half of the night will be mostly clear for most locations, except along the Allegheny Front where some stratus clouds will linger. After midnight, will see some increase in mid/high clouds across western areas of the forecast area as upper level energy moves through and warm air advection begins. Temperatures should be able to radiate quite well once decoupling occurs, especially across areas that remain clear. Lows mainly in the 20s. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... High pressure will be overhead to start the day Friday but will slide southward by the afternoon. Morning mid/high clouds will become less prevalent by the afternoon although with warm air advection regime, will likely still be some around. Temperatures will be considerably milder with highs in the 40s/50s, coolest across northeast Maryland, warmest across central Virginia. A system will be pushing across the southern Plains Friday and Friday night, and move into the southeastern US by Saturday. Heights will build out ahead of this, leading to dry and mild conditions. Expecting partly-mostly sunny/clear skies with some increasing clouds by Saturday afternoon. Lows Friday night in the 30s will warm significantly into the 60s on Saturday. Some low 70s also possible across central VA. The system moving into the SE US will be in a decaying stage by Saturday night, so its effects will be relatively minor across our area, aside from the increased chances for a few showers. Lows Saturday night in the 40s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... High pressure will build into the region Sunday through Tuesday. Dry conditions and mild temperatures will evolve during this stretch of time, especially Sunday. Will have to monitor for potential backdoor cold front Monday which would keep temperatures a bit cooler for Monday/Tuesday, although still above normal for February. By Tuesday night, a cold front should sag across the region and then stall overhead Wednesday. There is a chance for rain showers Tuesday night and Wednesday in association with the front. Temperatures will remain mild to the south of the front and slightly cooler to the north of the front. The next low pressure system that could affect the region should develop along the tail-end of the stalled front Wednesday night. This low could meander northeastward over the Carolinas, bringing a chance for rain showers to the mid-Atlantic Wednesday night into Thursday. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... Predominantly VFR conditions expected through Saturday night. Any flurry/snow shower activity will come to an end this afternoon. Gusty northwest winds up to around 30 knots will also diminish by tonight. There is the potential for some sub-VFR conditions Saturday night with chances for some rain showers as a system pushes to the south of the area. Mostly VFR conditions Sunday through Tuesday. There is a low chance of sub-VFR conditions with potential backdoor cold front Monday into Tuesday. Winds northwest 5 to 10 knots Sunday through Monday. Winds becoming northeast around 5 knots Monday night and Tuesday. && .MARINE... SCA remains in effect across all waters with gusty northwest winds this afternoon up to around 30 knots. Winds will gradually subside overnight, however with air temperatures cooler than the waters, mixing of the lingering stronger winds aloft may still occur overnight, so have kept Small Craft Advisory going for the lower tidal Potomac and portions of the Chesapeake overnight. Otherwise, mainly sub-SCA conditions expected Friday through Saturday night with developing south/southwesterly flow. No marine hazards Sunday through Tuesday. Winds northwest 10 to 15 knots Sunday through Monday. Winds becoming northerly around 10 knots. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until 6 AM EST Friday for ANZ531>534-537- 539>541-543. Small Craft Advisory until 1 AM EST Friday for ANZ530-538-542. Small Craft Advisory until 7 PM EST this evening for ANZ535- 536. && $$ SYNOPSIS...MM NEAR TERM...MM SHORT TERM...MM LONG TERM...KLW AVIATION...MM/KLW MARINE...MM/KLW is the U.S. government's official web portal to all federal, state and local government web resources and services.