Area Forecast Discussion
Issued by NWS Sterling, VA

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775 FXUS61 KLWX 210758 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 358 AM EDT Thu Sep 21 2017 .SYNOPSIS...High pressure both at the surface and aloft will build overhead through the weekend. Hurricane Maria may approach the mid- Atlantic coast middle of next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Early this morning, Jose continues to meander off the coast of New England, well to our east, while a ridge of high pressure is building over the midwest aloft. At the surface, the high pressure ridge extends along the Appalachians. The only fly in the ointment is the trough which brought showers and thunderstorms to western Virginia yesterday - this system remains nearby, but is slowly sinking south. Its influence may still bring a stray shower to the far southwestern corner of the CWA this afternoon, but odds look considerably less than yesterday, so have just included some slight chance POPS for now. Otherwise, patchy fog this morning should break for another mostly sunny and warm day, with another clear to partly cloudy night with more patchy fog. The air mass is drier than it was 24 hours ago, and we have not had significant rain in a couple weeks, so dense fog is not going to be as easy to come by as it might otherwise be. However, a few spots may drop to 1/4 mile early this morning and again late tonight, but not up to Dense Fog Advisory calibre. Highs today will be well into the 80s once again, with lows tonight in the 50s and 60s once again. Winds will be light. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... High pressure ridge at the surface will remain more or less stationary over the Appalachians through Saturday night. Aloft, ridge of high pressure centered over the Midwest will continue to extend its influence across our region, while Jose will continue to meander over the northwest Atlantic near New England. End result will be continued warm and dry weather, with the only real weather concern being extent and coverage of patchy fog each morning. Highs will be well into the 80s Friday and Saturday with lows in the 50s and 60s. Winds will be light. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Strong ridge of high pressure will remain in place through at least Sun and likely beyond albeit weakening. With regards to the track forecast of Hurricane Maria, global models show Maria having a similar track to Jose tracking a little west of 70W. Please consult NHC forecasts for more info on Hurricane Maria. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... Main concern through the next several days is patchy late night and early morning fog, mainly at MRB and CHO. Vis could drop briefly to IFR at either or both sites each of the next three mornings. An MVFR restriction is not out of the question at the other terminals (except DCA). Otherwise, VFR with light winds should prevail through Saturday night thanks to high pressure. No sig wx wx expected through Mon. && .MARINE... High pressure will provide dry weather with sub-SCA winds through Saturday night. Global models show winds strengthening on Tue as pressure gradient tightens as Hurricane Maria gets closer to the mid-Atlc coast middle of next week. For now, it appears small craft advisories are possible. && .TIDES/COASTAL FLOODING... Minor coastal flooding will continue at most of the sites over the next several days. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...Coastal Flood Advisory until midnight EDT tonight for DCZ001. MD...Coastal Flood Advisory until 5 PM EDT this afternoon for MDZ018. Coastal Flood Advisory until 9 AM EDT this morning for MDZ011. Coastal Flood Advisory until 9 PM EDT this evening for MDZ014. Coastal Flood Advisory until 7 AM EDT this morning for MDZ016. Coastal Flood Warning until 6 AM EDT early this morning for MDZ017. Coastal Flood Advisory until 7 PM EDT this evening for MDZ017. VA...Coastal Flood Advisory until 7 AM EDT this morning for VAZ057. Coastal Flood Advisory until midnight EDT tonight for VAZ054. WV...None. MARINE...None. && $$ SYNOPSIS...BJL/LFR NEAR TERM...RCM SHORT TERM...RCM LONG TERM...LFR AVIATION...RCM/LFR MARINE...RCM TIDES/COASTAL FLOODING...LFR is the U.S. government's official web portal to all federal, state and local government web resources and services.