Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
829 FXUS61 KLWX 300743 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 343 AM EDT Tue Apr 30 2024 .SYNOPSIS... A lee-side trof will move across the area this afternoon followed by a cold front late tonight. Ridging builds over the region during the second half of the week. A cold front will approach the area during the weekend and clear the area early next week. && .NEAR TERM /THROUGH TONIGHT/... A cold front associated with a surface low tracking north of the Great Lakes will cross through the forecast area this evening and into the overnight. This will bring a slight relief to well above normal temperatures and an increased chances of showers and thunderstorms. Temperatures will be slightly cooler compared to yesterday with highs in the 80s for most. Those in metro areas could reach the low 90s again with higher elevations staying in the 70s. Precipitation chances increase in the afternoon with storms becoming more likely in the evening. The threat for severe weather remains low, but not zero. Potential hazards include frequent lightning, locally heavy rain at times, and gusty winds during storms. Storms move out of the area around midnight, with a slight chance of precipitation lingering throughout the overnight as the front moves to our south. Overnight temperatures will be in the mid 50s to mid 60s. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... By Wednesday morning, the aforementioned cold front will be lifting northward as an upper level trough pivots over the area. This will allow for precipitation chances to linger throughout the morning. Recent model guidance has trended drier for Wednesday, with conditions expected to dry out areawide in the afternoon. Surface low pressure near the Carolinas make so an isolated rain shower cannot be ruled out in the southernmost portions of the area. However, chances for this remain low as dry air aloft filters into the area. Dry conditions continue on Thursday as high pressure builds in over the area. A moisture starved cold front will linger over the forecast area, but no precipitation is expected with this. High temperatures each day will be in the 70s to mid 80s with overnight lows dipping into the 50s to low 60s each night. && .LONG TERM /FRIDAY THROUGH MONDAY/... Large scale ridge will start breaking down Saturday as successive mid-level perturbations move across the Mid-Atlantic region during the second half of the weekend. Moisture will pool along a decaying/weakening frontal zone Saturday to bring the threat of showers. This frontal zone will be slow to exit the area with the risk of showers persisting through Sunday. Given the slow progression of this front, isolated heavy rain totals exceeding an inch are possible which may cause isold flooding in the more vulnerable urban areas. The lack of instability suggest any rainfall should be manageable. By Monday, enough dry air appears to make it into the area and the frontal zone dissipates to lower PoP chances allowing sunshine to bring temperatures back up. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... VFR conditions are expected this morning through the early afternoon, ahead of any precipitation expected later today. A cold front moving over the area will bring scattered showers and thunderstorms to all terminals this evening and into the late evening. Some storms may be strong, possibly producing winds gusts of 35 knots or greater, frequent lightning strikes, and heavy rainfall leading to reduced visibilities. Shower and thunderstorms chances move out of all terminals between 03-04 UTC with the exceptions being CHO where conditions dry out earlier around 01 UTC. Outside of showers and thunderstorms, VFR conditions are expected. Southwesterly winds today will shift to northwesterly winds on Wednesday. Winds gust between 10-15 knots this afternoon with winds gusting up to 20 knots at DCA. Winds diminish overnight before remaining light on Wednesday, blowing between 5-10 knots. VFR conditions continue on Thursday as high pressure builds in over the area. Showers are likely on Saturday. Cig restrictions are possible Saturday. && .MARINE... A cold front will cross the waters this afternoon and into the overnight, leading to increased chances of showers and thunderstorms. A SCA is in effect for this afternoon and into this evening for southwest winds 10 to 15 knots with gusts up to 20 knots expected. During thunderstorms, higher wind gusts of 35 knots or greater are possible along with lightning. Special Marine Warnings may be required as showers and thunderstorms cross the waters. By Wednesday morning, showers and thunderstorms will have moved away from the waters. Winds shift to the northwest an are expected to stay below SCA criteria. Winds shift to the south on Thursday, but continue to remain below SCA criteria. Small Craft Advisory conditions likely Friday through the weekend. Showers appear likely over the weekend, but the threat of thunderstorms remains low. && .CLIMATE... Below is a list of record high temperatures for today, April 30th. Apr 30th Climate Site Record High Forecast High Washington-National (DCA) 92F (1942+) 87F Washington-Dulles (IAD) 86F (2017+) 85F Baltimore (BWI) 92F (1910) 87F Martinsburg (MRB) 91F (1974+) 84F + denotes that multiple years reached this value, but the depicted year is the most recent && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from noon today to midnight EDT tonight for ANZ530>543. && $$ SYNOPSIS...LFR NEAR TERM...AVS SHORT TERM...AVS/EST LONG TERM...LFR AVIATION...AVS/LFR MARINE...AVS/LFR CLIMATE...LWX