Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 241817 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 217 PM EDT Mon Jun 24 2019 .SYNOPSIS... A frontal system will cross the Mid-Atlantic through tonight. High pressure will build from the Tennessee Valley toward the region through the end of the week. A cold front may approach from Pennsylvania this weekend. && .NEAR TERM /THROUGH TONIGHT/... Broken line of showers and thunderstorms along I-81 from near Hagerstown to Harrisonburg pushing eastward as of mid afternoon. Surface warm front is currently draped across central Virginia, and this is where scattered convection is expected to continue to focus this afternoon, with an isolated damaging wind gust or two and locally heavy rainfall possible given increasing moisture and instability as well as marginal shear. Max observed rainfall rates so far have been about 2 in/hr, but not persisting very long. Shear magnitude thanks to strengthening low-level jet increases this evening ahead of an approaching shortwave and developing MCS. This convective system is most likely to affect eastern WV zones this evening, weakening as it moves east. Some damaging wind gusts are possible mainly west of I-81 this evening, with spotty heavy rain possibly making it as far east as the I-95 corridor overnight. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Frontal system pushes east and falls apart Tuesday. No real appreciable rain chances and since the front will be falling apart, there`s no real airmass change. If anything, Tuesday will be even hotter given less cloud cover and downsloping westerly flow (though humidity may be a little lower). A weak front may touch off a pop up shower or thunderstorm later Wednesday afternoon and evening, but with rising heights and weak forcing anything should be very isolated at best. Otherwise, hot and humid weather continues with heat indices 95-100 for most areas. && .LONG TERM /THURSDAY THROUGH MONDAY/... Mid-upper level ridge will reach its maximum amplitude over our CWA Thu and Fri keeping convection suppressed. Highs will be in the mid 90s possibly reaching the upper 90s to near 100 as indicated in the 95th percentile by various global models. Despite the hot temperatures, heat indices appear will remain below the threshold of 105/100F east/west of the Blue Ridge respectively for Heat Advisories. Heights begin to fall Saturday as closed upper level low drops from Hudson Bay to northern New England. Its associated cold front is fcst to cross the area Sunday and bring a slight reprieve from the heat along a small risk of showers and t-storms. Ridge builds again during the first few days of July with temperatures rising again into the middle 90s. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... IFR restrictions possible in any heavy shower or thunderstorm activity until around midnight. Most likely to affect CHO/MRB. Patchy fog possible mainly near outlying terminals late tonight, but not confident enough in restrictions to put in TAF attm. Gusty winds possible near storms mainly W of I-81 this eve. Mainly VFR Tuesday through Saturday in W or SW flow. && .MARINE... SCA for mid Chesapeake Bay waters and lower tidal Potomac River through tonight for marginal southerly channeling. Gusts may extend further north to near the Bay Bridge tonight, but not high enough probability for a headline just yet. Could also be a few near 20 kt W/NW gusts behind a departing frontal system Tuesday morning. Generally light flow and dry but very warm weather anticipated Tuesday through Saturday. && .TIDES/COASTAL FLOODING... Tides running half to one foot above normal, approaching but likely not to exceed minor flood stage through Tuesday morning. Highest anomalies are expected this evening, but this is coincident with the lower of two daily high tide cycles. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until 6 AM EDT Tuesday for ANZ534-537-543. && $$ SYNOPSIS...DHOF NEAR TERM...DHOF SHORT TERM...DHOF LONG TERM...LFR AVIATION...LFR/DHOF MARINE...LFR/DHOF TIDES/COASTAL FLOODING...DHOF

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