


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. --423 FXUS61 KLWX 290036 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 836 PM EDT Sat Jun 28 2025 .SYNOPSIS...-- Changed Discussion --Showers and thunderstorms are likely Sunday as a weakening cold front drops southward into the area. Shower and thunderstorm chances continue Monday and Tuesday as a stronger cold front pushes through. Less humidity and drier conditions are expected late next week.-- End Changed Discussion --&& .NEAR TERM /THROUGH SUNDAY/...-- Changed Discussion --Storms will continue to gradually diminish through the late evening hours with loss of daytime heating, with mainly dry conditions through the overnight hours. Some patchy fog can`t be ruled out late tonight, especially in locations that receive thunderstorms during the daylight hours. Overnight low temperatures will be in the upper 60s to the west of the Blue Ridge, and lower to middle 70s further east.-- End Changed Discussion --&& .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... Additional shower and thunderstorm chances are possible for portions of the area Sunday as a decaying weak cold front drops southward into the region. Current 12z CAM/synoptic guidance place this boundary in the vicinity of the I-66/US-50 corridor or just south of it into central VA Sunday afternoon. The boundary will have little impact on temperatures with highs once again reaching back into the upper 80s and low 90s. Humidity may drop off a little bit especially for those the further north of I-66/US-50 where modeled PWAT values look to fall into the 1.1 to 1.4 inch range Sunday afternoon and evening. Areas south of I-66/US-50 will continue to deal with the rich moisture laden air with PWATS around 2 inches. This will be the primary area for convective development (south of I-66/US-50) Sunday afternoon. SPC continues to maintain a Marginal Risk for most of central and eastern VA during this timeframe with locally damaging winds from wet microbursts and instances of flash flooding as the primary threats. Storms will diminish with the loss of daytime heating Sunday night with lows once again falling back into the upper 60s and low 70s. More widespread shower and thunderstorm activity is possible Monday especially in northern parts of the forecast area as a washed out front sits nearby. At the same time, will monitor the progression of pre-frontal trough off to the west and encroaching strong cold front approaching from the Ohio River Valley Tuesday. A warm and humid airmass remains in between these two systems yielding ample instability and subtle shear for storms to feed off of especially during the peak heating period. SPC once again highlights the entire area for a Marginal Risk (Level 1 out of 5) for severe weather. Locally damaging winds and isolated instances of flooding will remain possible with CAPE values greater than 2000 j/kg, 0-6 km shear values less than 30 kts, and PWATS around or /above 2". Highs Monday will climb back into the upper 80s and low 90s with heat index values hovering close to 100 degrees. Lows Monday night will sit in the low to mid 70s. && .LONG TERM /TUESDAY THROUGH SATURDAY/...-- Changed Discussion --Potent shortwave-trough and accompanying sfc cold front will cross the area Tuesday afternoon and bring an organized threat of severe thunderstorms Tuesday afternoon into the evening. The main threat will be damaging winds given expected fast storm motions, ample shear and strong instability. After trough axis passes Tuesday night, height rises and building high pressure will result in seasonable warm and dry/tranquil conditions through the remainder of the week. A reinforcing dry cool front will push through the area Fri bringing cooler and drier air mass for the upcoming Fourth of July weekend.-- End Changed Discussion --&& .AVIATION /01Z SUNDAY THROUGH THURSDAY/...-- Changed Discussion --Convection will slowly diminish this evening. Areas of patchy fog are possible tonight with vsbys remaining MVFR or greater at most of the terminals outside of KCHO. Additional showers and thunderstorms are possible Sunday afternoon and evening as a decaying cold front sags southward into the region. VFR conditions will prevail for most with sub-VFR reductions at times for terminals south of KIAD and KDCA. Highest coverage of thunderstorm activity looks to be down around KCHO-KSHD-KLYH-KRIC with limited to no coverage up toward KBWI-KMRB where slightly drier/stable air will push in. Winds will switch to the northwest at less than 10 kts. VFR conditions at all terminals Monday with exception to brief MVFR conditions in strong thunderstorms during the afternoon and evening hours. Numerous showers and thunderstorms expected Tuesday afternoon, some possibly severe with damaging winds. Dry conditions expected Wednesday and Thursday.-- End Changed Discussion --&& .MARINE...-- Changed Discussion --Sub-SCA level winds are expected to continue through Monday morning. Winds will be light and variable Sunday. Southerly winds return Monday with some channeling possible especially over the open and middle waters Monday afternoon and evening. Expect the chance of an SMW or two each afternoon and evening through Monday as a result of scattered showers and thunderstorms. SCA conditions expected late Monday night into Tuesday as the gradient tightens ahead of an approaching cold front from the Ohio River Valley. SCA conditions likely Tuesday-Tuesday night. Severe t-storms are likely Tuesday afternoon, which may require SMWs.-- End Changed Discussion --&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...EST NEAR TERM...CPB/EST SHORT TERM...EST LONG TERM...LFR AVIATION...LFR/CPB/EST MARINE...LFR/KJP/CPB/EST