Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 270037 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 837 PM EDT Fri Aug 26 2016 .SYNOPSIS... A dry cold front will move through the area this evening. High pressure will build tonight through early Sunday. Another cold front will move through the area middle of next week. && .NEAR TERM /THROUGH SATURDAY/... A weak boundary over the area this evening currently extends across northern Virginia into southern Maryland. There is a dewpoint gradient along the boundary...and a couple showers and thunderstorms develop to the south of this boundary across central Virginia. This activity should dissipate this evening due to the loss of daytime heating. The boundary will slowly shift south tonight and a ridge of high pressure both at the surface and aloft will build over the area through Saturday. Mainly clear skies and light winds will cause patchy fog in sheltered valleys and rural areas...but widespread fog is not expected at this time. Plenty of sunshine is expected Saturday and unseasonably hot conditions will continue...but not quite as hot as Friday with max temps forecast to be in the upper 80s to lower 90s across most locations. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... Surface high pressure will shift to the coast Saturday night and a light easterly flow is expected. This may lead to low clouds toward morning across eastern portions of the CWA. For locations west of the Blue Ridge Mountains...mainly clear skies are expected with patchy fog. Latest GFS suggests some increase in moisture with some light showers over the mtns Sun as easterly flow continues. Think this is largely overdone given vertically stacked high pressure center over the area resulting in strong subsidence. Will downplay precip potential. Hot again with temps in the low 90s. && .LONG TERM /MONDAY THROUGH FRIDAY/... Ridge of high pressure will begin to weaken Mon with a dissipating front to the north and west. The weakening ridge and increasing warmth and instability may result in isolated showers and t-storms over the mtns. Heights will fall more sharply Tue and Wed as a pair of nrn stream disturbances move across. The stronger of these will help push a cdfnt through the area Wed night bringing better precip potential to the area Wed afternoon. Trough pushes east Thu with high pressure building again Thu through the Labor Day weekend. Hotter and more humid Mon through Wed with temps in the mid 90s and heat indices above 100F. Much cooler Thu and Fri behind front with temps in the mid 80s. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... Patchy fog may develop overnight into early Saturday. MVFR vsbys are possible across KMRB and KCHO during this time. Easterly flow may impact the terminals late Saturday night through Sunday night. Areas of low clouds and fog are possible during the late night and early morning hours each day. Precip chances increase Tue and Wed with showers/t-storms possible especially Wed. && .MARINE... Winds increase somewhat Sat and Sun afternoons, but will likely remain below SCA criteria. T-storms possible Wed afternoon with a frontal passage. && .CLIMATE... High temperature tied the old record of 95 degrees at Washington Dulles Airport today. The old record of 95 occurred in 1998...1993 and 1975. Ranking of summer 2016 in terms of average temperature (JUN 1 - AUG 25) Site RankAverage Temperature DC 3 (tie with 2012)80.4 Balt 19 (tie with 2 other years) 77.2 IAD 3 77.2 && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...LFR NEAR TERM...BJL/LFR SHORT TERM...LFR LONG TERM...LFR AVIATION...BJL/LFR MARINE...BJL/LFR CLIMATE...ABW/BJL is the U.S. government's official web portal to all federal, state and local government web resources and services.