Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
440 FXUS61 KLWX 310745 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 345 AM EDT Fri Jul 31 2026 .WHAT HAS CHANGED... No significant changes made to the forecast this morning. Small Craft Advisory will be needed for most of the waters for Saturday afternoon to evening. && .KEY MESSAGES... - 1) Increasing shower and thunderstorm chances this weekend into next week. && .DISCUSSION... KEY MESSAGE 1...Increasing shower and thunderstorm chances this weekend into next week. Expecting another dry summer day as weak high pressure moves over the region. Temps will be slightly warmer in the upper 80s to low 90s, with light northwest winds through this evening. Southerly flow returns tonight into this weekend as the high pressure moves offshore. in its wake a potent upper level trough moves east from the Great Lakes toward the Ohio River Valley. The upper level trough then pinches off into a cut low near Ohio late Sunday night. The associated cold front is progged to slowly track across the area during the second half of the weekend into early next week. Moisture return ahead of this system begins Saturday where scattered showers and thunderstorms return to the forecast. Convection looks to be focused mainly west of the Blue Ridge on Saturday, then widespread showers and thunderstorms are most likely Sunday into Sunday night. Shear and instability values look to remain low due to weak winds aloft and widespread cloud cover. Locally heavy rainfall is possible Sunday night, but the exact placement and intensity will depend on where the cutoff low and jet streak aloft are located. A few ensemble members show the possibility of rain amounts upwards of 2-3" if favorable dynamics come together. On Monday, the cutoff surface low pressure system near the Ohio River Valley continues to fill in and increase in pressure. Although ensembles tend to weaken the low pressure system Monday, widespread showers and thunderstorms chances continue throughout the day with abundant cloud cover. As the upper level trough associated with Monday`s weather leaves our region Tuesday, conditions remain unstable with an abnormally moist airmass remaining over our region through much of next week. With peak heating, diurnal thunderstorms cannot be ruled out next week with chances increasing into the work week. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... VFR conditions are expected through at least Sunday morning as high pressure over the region moves offshore. Sub-VFR conditions likely at some point Sunday afternoon/evening as a cold front slowly approaches from the west. A period of rain, with some thunderstorms, are likely Sunday night. VFR conditions Monday through Tuesday night for the most part. There is a chance for showers and thunderstorms both day that could bring brief MVFR or IFR conditions, primarily Monday and particularly near CHO terminal. Winds south to southwest 5 to 10 knots Monday. Winds becoming northeast 5 to 10 knots Tuesday, then southeast late Tuesday. && .MARINE... High pressure moving over the region today maintains light winds over the waters, with a return of southerly flow tonight as the high moves offshore. SCA conditions are likely each afternoon/evening this weekend, especially over the open waters of the Chesapeake Bay where southerly channeling will be strongest. A few thunderstorms possible over the waters Sunday night. No marine hazards expected at this time through Tuesday night. Winds south to southwest 5 to 15 knots Monday. Winds becoming northeast 5 to 10 knots Tuesday, then southeast late Tuesday. && .TIDES/COASTAL FLOODING... Tidal anomalies are forecast to slowly rise this weekend as southerly flow returns. Sensitive tidal locations will reach Action Stage during high tide cycles, with Annapolis forecast to reach minor flood stage during the Saturday morning high tide cycle. Other locations could also approach minor flood stage this weekend. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ DISCUSSION...KRR/KVH AVIATION...KRR/KVH MARINE...KRR/KVH