Area Forecast Discussion
Issued by NWS Sterling, VA

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466 FXUS61 KLWX 170758 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 358 AM EDT Tue Apr 17 2018 .SYNOPSIS...Low pressure over Quebec will maintain unseasonably cool conditions through today. Weak high pressure will build over the area late tonight into Wednesday. A cold front will cross the area on Thursday. High pressure will build over the region for the end of the week. && .NEAR TERM /THROUGH TONIGHT/... Low pressure over Quebec this morning will maintain a northwest flow across the region today with continued cool weather. A few breaks in the clouds are seen from Fauquier county south to Orange early this morning, but these will be short-lived as bkn-ovc stratocumulus fill in again after sunrise with continued PVA and NW flow. Upslope snow showers are expected over the Appalachians with a few rain or snow showers possibly making it east of the mtns and especially along the Mason Dixon line. Clearing and cold tonight with diminishing winds. More freeze watches and/or warnings may be required as far east as U.S. Rt 15 and Rt 29 corridors and will likely issue them a little later. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... Nice day on Wed as weak high pressure remains overhead. Warmer with temperatures in the mid 60s and light winds. Clouds increase late in the day ahead of next low pressure system moving across the midwest. Nmrs-widespread rain showers expected especially NW with lesser chances south and east. Cdfnt crosses the area around 12Z Thu with cold air filtering in quickly with rain showers turning to snow showers in the mtns. Turning windy especially in the mtns and northeast MD where wind advzy conditions are possible. Turning much colder Thu night and remaining brisk with more freezing temperatures likely. && .LONG TERM /FRIDAY THROUGH MONDAY/... The long term will start out cool and breezy as high pressure gradually builds in from the northwest while low pressure strengthens as it heads its way northeast along the Maine coast. There could be some lingering upslope snow showers along the Allegheny Front Friday morning, but otherwise it should also be dry. With Canadian high pressure building more firmly overhead Saturday and Sunday, we will remain cool and dry, though the breeze should diminish. We will once again have frost/freeze concerns Saturday and Sunday mornings, but otherwise no hazardous weather is expected. The northerly flow will become a bit more easterly by early next week as high pressure slides towards northern New England and a low pressure system moves east along the Gulf Coast. Otherwise, expect the cool dry weather to continue into early next week. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... Breezy today with bkn-ovc cigs 040-050. Clearing tonight with diminishing winds. No weather on Wed. Windy on Thu with gusts 30-40kt. VFR conditions expected Friday and Saturday. A gusty northwest wind on Friday should diminish Saturday. && .MARINE... SCA conditions today. Winds diminish tonight. Gale conditions possible on Thu. Small Craft Advisories may be necessary Friday in the wake of low pressure moving northeast along the Maine coast. Winds likely diminish a bit Saturday. && .TIDES/COASTAL FLOODING... Minor coastal flooding possible at Washington Channel later this morning at high tide. Will reevaluate situation again in the next hour or so. Anomalies already dropping elsewhere and no more advisories needed. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Coastal Flood Advisory until 6 AM EDT early this morning for MDZ017. VA...Freeze Warning until 9 AM EDT this morning for VAZ025>031-507- 508. WV...Freeze Warning until 9 AM EDT this morning for WVZ051>053. MARINE...Small Craft Advisory until midnight EDT tonight for ANZ530>532- 535-536-538>540. Small Craft Advisory until 6 AM EDT Wednesday for ANZ533-534- 537-541>543. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...RCM AVIATION...RCM/LFR MARINE...RCM/LFR TIDES/COASTAL FLOODING...LFR is the U.S. government's official web portal to all federal, state and local government web resources and services.