Area Forecast Discussion
Issued by NWS Sterling, VA
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Issued by NWS Sterling, VA
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-- Discussion containing changed information from previous version are highlighted. --783 FXUS61 KLWX 021433 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 1033 AM EDT Thu May 2 2024 .SYNOPSIS... An upper level ridge will build over the area today through Friday. Meanwhile, a backdoor cold front will cross the area late Thursday night into Friday before sinking south this weekend. A secondary cold front and area of low pressure will pass through the area Sunday into early next week. && .NEAR TERM /THROUGH TONIGHT/...-- Changed Discussion --MID MORNING UPDATE... Mostly clear skies are expected today, with the exception of some high clouds. Some patches of fair weather cumulus are also in the forecast for today, primarily along and west of the Blue Ridge, with some already evident on visible satellite. With high pressure, dry conditions are expected but a stray shower west of the Blue Ridge can`t be ruled out. PREVIOUS DISCUSSION FOLLOWS... An upper level ridge will build over the East today leading to hot and record high temps at IAD and BWI. Humidity levels will be manageable due to dewpoints below 60. It should remain mostly clear tonight, except for some cirrus. Backdoor cold front will enter the picture late tonight with winds turning from the NE. No precip is expected.-- End Changed Discussion --&& .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... Plenty of cirrus Fri and cooler as high pressure wedges south. This will allow for onshore east to southeast flow to increase across the area especially east of the Blue Ridge. Isolated to scattered mountain showers and t-storms are expected as cdfnt banks against the Appalachians. Showers stay mainly west of the Blue Ridge Fri night, but begin to progress east Saturday into Sunday as shortwave perturbations break down the ridge pattern. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... A weak low pressure system and associated cold front will move through the area on Sunday. The cold front will stall over the forecast area Monday and Tuesday before lifting northward as a warm front Tuesday afternoon. This will bring a prolonged period of unsettled weather as we close out the weekend and begin the workweek. Shower and thunderstorm chances peak Sunday as the front moves through the area. rainfall will be heavy at times with localized instances of flooding possible due to southerly flow providing ample moisture. WPC has the western those along and west of the Blue Ridge in a marginal risk for excessive rainfall. At this time, the severe risk is low with limited instability. Slight chance to chance PoPs linger through midweek as the aforementioned frontal boundary remains stalled over the area. Afternoon showers and thunderstorms are possible each day. High temperatures on Sunday will range from the mid 60s in NE Maryland and higher elevations to the upper 70s in central Virginia. Overnight low temperatures will fall into the upper 50s to low 60s. There will be a gradual warming trend each day with highs reaching the upper 80s on Wednesday. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... VFR today and Fri. Marine layer pushes inland Fri night into Saturday with MVFR cigs developing. A cold front moving through the area and then stalling to our south will bring unsettled weather to all terminals Sunday and Monday. During showers and thunderstorms, reduced CIGs and VSBYs are possible. Gusty southerly winds will gradually decrease throughout the day Sunday, gusting 15-20 knots in the morning. Winds remain out of the southeast on Monday, blowing 5 to 10 knots. && .MARINE... SCA issued for Fri as onshore flow strengthens. It will likely need to be extended into Saturday and beyond. Showers and thunderstorms are possible over the waters Sunday and Monday. Gusty southeasterly winds on Sunday will likely be SCA criteria. Winds remain out of the southeast on Monday, diminishing to sub-SCA criteria. && .TIDES/COASTAL FLOODING... Onshore flow will lead to rising water levels Saturday into Sunday with minor coastal flooding expected during the weekend. && .CLIMATE...-- Changed Discussion --Well above normal temperatures are forecast today. Below is a list of daily high temperature records. ==================================================================== Record Daily High Temperatures for Thursday 05/02 ==================================================================== Site Thursday 05/02 value (Year record was set) -------------------------------------------------------------------- Record Highs Thursday 05/02 Sites Records/Year Forecast High Washington DC (DCA) 91/2018 90 Dulles(IAD) 88/2018 89 Baltimore, MD (BWI) 90/2018 93 Martinsburg, WV (MRB) 95/1942 86 Charlottesville, VA (CHO) 91/2018 89 Hagerstown, MD (HGR) 90/2018 86 Annapolis, MD (NAK) 90/1992 84 =================================================================== = Site Legend ------------------------ DCA area - Washington DC BWI area - Baltimore MD Table Legend IAD area - Sterling/Dulles VA ------------------------ MRB area - Martinsburg WV Temperature (Year) CHO area - Charlottesville VA HGR area - Hagerstown MD NAK area - Annapolis MD Although the facilities (airports, etc.) where temperatures are currently observed were built in the mid to late 20th century, additional temperature records taken at nearby sites before that extend the valid periods of record back into the late 1800s (except for IAD, where records go back to 1960). Record Event Reports (RERs) are only issued for the sites denoted with a (*). All climate data is considered preliminary until reviewed by the National Centers for Environmental Information (NCEI).-- End Changed Discussion --&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from 11 AM to 6 PM EDT Friday for ANZ530>543. && $$ SYNOPSIS...LFR NEAR TERM...LFR/CAS SHORT TERM...LFR LONG TERM...AVS AVIATION...AVS/LFR MARINE...AVS/LFR TIDES/COASTAL FLOODING...LFR CLIMATE...LWX