Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 191853 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 253 PM EDT Wed Apr 19 2017 .SYNOPSIS...High pressure off of Atlantic Canada will move further away from the coast tonight and Thursday. A lee-side trof will setup across the area tomorrow. A cold front will cross the area Friday afternoon. Weak high pressure builds over the area Friday night before another low pressure impacts the area Saturday night and Sunday. && .NEAR TERM /THROUGH THURSDAY/...Light rain over ncntrl MD will taper off later today with patchy drizzle and areas of fog developing late tonight as mid-levels dry out and moist air remains in place near the sfc. Low clouds/fog dissipate by mid- morning Thu with risk of showers and t-storms as lee-side trof sets up and provides lift and instability builds as temps rise through the 70s to perhaps 80F. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...Shra/tsra activity will wane with loss of heating Thu evening, but approaching cdfnt from the west could bring another round of late night and early morning showers Thu night and Fri. Still warm on Fri with sufficient moisture and instability Fri afternoon for another round of showers/t-storms mainly across the southern half of the fcst area. The 12Z GFS wants to push the front all the way into North Carolina, but the latest Euro keeps the front across srn VA keeping the risk of showers across srn zones. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... An area of low pressure will take shape over the south-central CONUS Saturday morning, then slowly push east just south of the area through the second half of the weekend. Models are in general agreement with this setup, which should result in a beneficial soaking rain across much of the area. A cool area of high pressure will persist to the north following the weekend system which should keep temperatures near to below normal for this time of year during the first half of next week. Periods of clouds or sprinkles will be possible in onshore flow as well. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/...MVFR/IFR cigs developing tonight with areas of fog with 1-3SM vsbys. Sct-nmrs showers and t-storms Thu afternoon potentially affecting all TAFs sites. Cdfnt moves through Fri afternoon with risk of showers/t-storms again on Fri. Sub-VFR likely over the weekend with rain. Winds will generally be out of the northeast around 10 knots or so. && .MARINE...Canadian HRDPS suggests winds will increase across the waters tonight, but other reliable guidance such as the GEFS and SREF indicate winds will remain steady and perhaps even diminish tonight. Solid SCA not likely until Sun afternoon when low pressure moves offshore. Northeasterly winds of 10 to 15 knots are expected across the waters over the weekend as low pressure passes to the south. Gusts would exceed 20 knots for a time especially Saturday as the pressure gradient tightens between low pressure developing to the southwest and high pressure developing to the northeast. && .TIDES/COASTAL FLOODING...Minor coastal flooding expected at Straits Point over the next two high tide cycles tonight and Thu morning as onshore flow persists. Cdfnt will clear the area Fri afternoon with positive anomalies dropping. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Coastal Flood Advisory from 7 PM this evening to 11 AM EDT Thursday for MDZ017. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...DFH AVIATION...LFR/DFH MARINE...LFR/DFH TIDES/COASTAL FLOODING...LFR is the U.S. government's official web portal to all federal, state and local government web resources and services.