Area Forecast Discussion
Issued by NWS Sterling, VA

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880 FXUS61 KLWX 230844 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 444 AM EDT MON MAY 23 2016 .SYNOPSIS... Low pressure east of Norfolk this morning will move north towards New England today and tonight, then move into the Canadian Maritimes on Tuesday. High pressure over the Midwest will slide southeastward into the western Atlantic by Tuesday night, where it will remain through next weekend. && .NEAR TERM /THROUGH TONIGHT/... Latest analysis shows our nearest significant features to be a surface low pressure east of Cape Hatteras and surface high pressure centered over Michigan. Aloft, a deep closed low is centered over southern Virginia while a sharp ridge extends northward from eastern Texas to Lake Superior. The upper level features will generally shift slowly eastward today while the surface low will move north and the high moves southeastward. This shift should cause the isentropic lift/cool conveyor belt precip over our region to diminish this morning. However...with the potential for breaks in the clouds by this afternoon and the strong late May sun (equal to mid July in strength) combined with plentiful low level moisture and the cold low aloft...and the stage will be set for additional shower development along with possible thunderstorms. Do not expect any severe but wouldn`t be shocked by some small hail. alluded to by the sun mention...temperatures should be able to rebound a bit after any patchy morning fog dissipates...but cool air aloft with the closed low will prevent them from reaching normal no matter what. Tonight the low aloft and at the surface both head northeastward away from us and their influence should wane. We will likely still have some showers and even a thunderstorm or two to deal with in the early evening...but precip and then clouds should wane as the night progresses. Lows will remain near normal with limited advection behind the system so far and the moist atmosphere may result in fog development. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Ridge continues moving east towards us on Tuesday as the low pressure system pushes further northeast away from us. Some clouds or even a stray shower may linger early Tuesday but we should end up with a much nicer day. As already mentioned...some patchy fog could also impair conditions early but it should not persist as northwest downslope winds should bring sun back to the region. Temps should also rebound considerably as temps warm quickly aloft and the sun does its job. Unlike today...with the warming aloft we should not see much if any attempt at convection in the afternoon. Highs will reach the high 70s to even some low 80s. Continued improvement with ridging moving in Tuesday night through Wednesday night. Warmth will also increase as westerly to southwesterly flow develops aloft and at the surface. Will need to watch a shortwave with attendent weak frontal boundary later Wednesday and Wednesday night which may try to spark off a shower or storm but overall think period is dry. Highs into the 80s most spots Wednesday. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Bermuda high pressure sets up Wednesday night and persists at least through the Memorial Day weekend. Moisture influx from SLY flow around the high should enable afternoon/evening thunderstorms Thursday through Monday per typical diurnal trends in this pattern. General thunderstorms expected with low bulk shear. Warmest stretch of the year so far. Mid to upr 80s max temps expected Thursday through Monday. Only caveat is how quickly clouds develop and where rain falls before the diurnal maximum in temperatures. Areas sunniest longest may hit 90F any of the days. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... Low clouds and patchy fog potential...along with showers...will cause MVFR this morning in many areas and perhaps some times of IFR. Will need to closely monitor this as guidance has been too pessimistic so far. Conditions improve today with VFR expected at times especially this afternoon...but showers and t-storms may result in reductions. After showers end this evening we may again have fog issues with IFR potential. VFR returns Tuesday and should persist thru Wednesday night. Bermuda high sets up wednesday night with diurnal thunderstorms and light SLY flow starting Thursday. IFR conds expected in heaviest activity. && .MARINE...
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Generally light winds next 72 hours. Exception is near the mouth of the Potomac, where northerly channelling is resulting in gusts around 20 knots. Expect this to wane by mid-morning as winds shift but for now have issued SCA til then. Othwersise..showers today and a few t-storms possible this afternoon...then drying next few days. However...low passing to east on Tuesday may bring NW winds to 20 knots. SCA potential exists. Light SLY flow begins Wednesday night as a Bermuda high sets up. Localized SMWs likely any day. Will need to watch for SLY channeling.
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DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until 8 AM EDT this morning for ANZ534- 537.
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&& $$ SYNOPSIS...RCM NEAR TERM...RCM SHORT TERM...RCM LONG TERM...BAJ AVIATION...BAJ/RCM MARINE...BAJ/RCM is the U.S. government's official web portal to all federal, state and local government web resources and services.