Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
223 FXUS61 KLWX 311411 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 1011 AM EDT Fri May 31 2024 .SYNOPSIS... High pressure will build across the area today through Saturday before sliding offshore Sunday. Dry conditions and below normal temperatures will continue as a result into the start of the weekend. Temperatures start to warm with increasing shower and thunderstorm chances Sunday into the middle part of next week. && .NEAR TERM /THROUGH TONIGHT/... It was a frosty start in the high valley locations of western MD, western VA, and eastern WV this morning with temperatures in the mid 20s and low 30s. Elsewhere, many locations decoupled into the upper 40s and low to mid 50s. Frost Advisories have been allowed to expire for the mountains with mostly sunny skies prevailing across the entire forecast area. Synoptically, upper level troughing will continue push further offshore while large Canadian high pressure builds into the region. This will lead to abundant sunshine across the region along with comfortable humidity values thanks to north to northwesterly flow. Light north to northwest breezes will continue to blow through mid- afternoon as the center of the high swings overhead. Gusts of 15-20 mph can be expected mainly east of the Blue Ridge before the gradient relaxes late afternoon into the early evening hours. Even with the breeze, high temperatures will recover nicely into the low mid 70s for most with mid to upper 60s over the mountains. Another chilly night is expected with mid to upper 40s mainly along and west of the Blue Ridge and low to mid 50s further east. Some high sheltered valley locations could fall back into the upper 30s depending on how quickly things decouple with clear skies and light winds in place as high pressure sits overhead. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... Dry conditions continue into Saturday with a return of some high cirrus clouds around. A gradual warmup is expected with afternoon highs on Saturday in the upper 70s to low 80s. Winds will remain light out of the south throughout the day. By Saturday night, clouds will continue to increase from the west with dry conditions expected and overnight lows in the mid 50s to low 60s for most of the area. By Sunday, low-level moisture will increase thanks to a series of shortwaves that will impact the Mid-Atlantic through early next week. Isolated to scattered showers and thunderstorms will be possible on Sunday, moving in from west (early) to east (later). Overall, any storms should behave in terms of intensity but cannot completely rule out some gusty winds or hail with any storms that strengthen. Winds out of the southwest will strengthen during the day, with 15 to 20 knot gusts possible. && .LONG TERM /MONDAY THROUGH THURSDAY/... A weak upper trough will depart offshore on Monday, leaving us under low-amplitude upper level ridging for Monday into Tuesday. Instability is expected to be limited both days, and there won`t be much synoptic scale forcing for ascent, so conditions are expected to remain mainly dry. High temperatures both days are forecast to be in the low-mid 80s, with overnight lows in the 60s. As we move toward the middle of the week, upper troughing and an associated surface cold front will start to dive southeastward from the Northern Plains toward the Great Lakes, and eventually the Northeast/Mid-Atlantic. Spread in model guidance starts to increase during this time period, with some solutions showing the trough closing off into an upper low and becoming cut off from the main belt of westerlies to our north. This casts some uncertainty in both the temperature and precipitation forecast, but most guidance favors increasing chances for afternoon showers and thunderstorms on Wednesday and Thursday. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... VFR conditions are expected for the terminals through the first half of the weekend. Dry conditions are expected for the terminals during this time thanks to an area of high pressure nearby or overhead. Northerly winds may be a bit gusty (15-20 knots) for a short period this afternoon before subsiding. Winds will become southerly and light on Saturday. Sub-VFR conditions may briefly mix into the area late Sunday ahead of an approaching disturbance poised to bring showers and thunderstorms back to the terminals Sunday afternoon and evening. Prevailing VFR conditions are expected on both Monday and Tuesday. Winds will be light out of the north to northwest on Monday, and light out of the southeast on Tuesday. && .MARINE... SCA winds are expected through a majority of today with gusts up to 20 knots out of the north. These winds will begin to subside later today and into tonight. Sub-SCA winds are expected through early Sunday before some gusty southerly winds pick back up along with isolated showers and thunderstorms that may cross the waters later in the day on Sunday. Sub-SCA northerly winds are expected on Monday. Winds should turn southeasterly on Tuesday and remain sub-SCA in nature. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until 11 AM EDT this morning for ANZ530>532-538>540. Small Craft Advisory until 5 PM EDT this afternoon for ANZ533- 534-537-541>543. && $$ SYNOPSIS...EST NEAR TERM...EST SHORT TERM...ADM LONG TERM...KJP AVIATION...KJP/ADM MARINE...KJP/ADM