Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
834 FXUS61 KLWX 030759 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 359 AM EDT Fri May 3 2024 .SYNOPSIS... A backdoor cold front will cross the area today before sinking south this weekend. A secondary cold front will pass through the area Monday. && .NEAR TERM /THROUGH TONIGHT/... Backdoor cold front is currently crossing the Potomac River from northeast to southwest as seen on TDWRs base reflectivity product. NE winds will cool things down significantly today with high temperatures 10 degs or more cooler than yesterday. There will be plenty of high level clouds around through much of the day. Sct-nmrs afternoon showers and t-storms are expected to develop, but should remain primarily west of the Blue Ridge. Sfc to upper level ridging to the east should keep things dry through tonight. As onshore flow strengthens tonight, expect marine layer to advect well inland with a low thick overcast expected by daybreak Saturday. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... A series of weak upper level perturbations will move across the region over the weekend gradually eroding the ridge pattern and allowing moisture to deepen, particularly during the Saturday night and Sunday time frame. Expect a gloomy and soggy weekend with off and on showers through Sunday evening. Rainfall amounts are likely to exceed one inch over the entire weekend. The lack of instability suggests that rainfall rates will be manageable. Also, the long duration of the event should allow for the ground to absorb much of the rain without causing much in the way of flooding problems. && .LONG TERM /MONDAY THROUGH THURSDAY/... A cold front draped across the region Monday and Tuesday will bring unsettled weather to the forecast area. Diurnally driven showers and thunderstorms are possible both days with atmospheric conditions peaking each afternoon and into the evening. Ample moisture aloft (PWATS 1.5in-2 in) will allow for heavy rainfall rates at times. Beginning Tuesday, the focus will be on the parent low pressure system as it begins to lift northward through the Great Lakes region. The cold front draped over the forecast area will begin lifting northward as a warm front while the associated cold front approaches from the Plains. From Tuesday through the remainder of the long term period, the forecast area will be in the warm sector allowing for an increasing threat for strong to severe thunderstorms. In addition to the severe weather threat, isolated instances of flooding are possible due to recent weekend rainfall possibly saturating soils. We will continue to monitor this system as is approaches. Temperatures will be in the 70s to low 80s Monday and Tuesday with overnight low temperatures expected to be in the mid 50s to mid 60s. In the wake of the warm front, temperatures rise into the 80s for most Wednesday and Thursday. Those at higher elevations will stay in the upper 70s each day. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... VFR through 06Z Sat, then rapidly lowering cigs overnight to IFR/LIFR as onshore flow develops. Off and on rain/showers develop Saturday and persist through Sunday with prevailing IFR conditions persisting through early next week. Reduced CIGs and VSBYs are possible during showers and thunderstorms Monday and Tuesday. Outside of showers and thunderstorms, VFR conditions are expected along with light winds 5-10 knots and gusting up to 15 knots. Winds will be out of the south each day. && .MARINE... SCA conditions develop later this morning and likely persist through Monday as onshore flow strengthens. Rain/showers will be widespread both Saturday and Sunday, but the threat of thunder will remain low. Showers and thunderstorms will impact the waters both Monday and Tuesday as southerly winds stay below SCA criteria. As a warm front moves over the waters, winds increase to just below SCA criteria Tuesday night. && .TIDES/COASTAL FLOODING... Onshore flow will strengthen today and persist through early next week. This will raise water levels and keep them elevated through early next week causing minor coastal flooding as early as Saturday. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from 11 AM this morning to 6 PM EDT Saturday for ANZ530>534-537>543. Small Craft Advisory from 11 AM this morning to midnight EDT tonight for ANZ535-536. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...AVS AVIATION...AVS/LFR MARINE...AVS/LFR TIDES/COASTAL FLOODING...LFR