


Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
172 FXUS61 KLWX 011912 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 312 PM EDT Tue Jul 1 2025 .SYNOPSIS... An upper trough and associated cold front will move through the area later tonight into tomorrow. High pressure will build over the area later this week into the weekend. && .NEAR TERM /THROUGH TONIGHT/... Multiple lines of showers and thundestorms are currently ongoing at this time. Radar trends and simulated satellite imagery from various models indicate lines may merge across central and northeast MD posing a significant flash flooding threat into the evening. New 12Z ECMWF AIFS Ensembles and its ensemble mean show potential for significant rainfall totals along the US-29 corridor and I-95 from Washington DC to Wilmington DE. Severe threat should start diminishing after 00Z, but flooding may still be ongoing after 00Z. Peak rainfall rates should start diminishing after 00Z tonight as instability is exhausted, but light rain will continue well through the night on the cool side of the sfc boundary. A rainy night is expected for most tonight. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... Showers are still likely to be ongoing south of I-70 at 12Z Wed, but should start progressing southward more rapidly through the day and should have mostly exited the fcst area by 18Z, except perhaps the southern tip of St. Mary`s County. After that, dry air will filter in. A reinforcing shortwave-trough will move across the area Thu afternoon bringing a threat of showers or thunderstorms across areas west of I-81. Dry Thu night into Fri just in time for the Fourth of July. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Dry conditions and seasonable temperatures continue Friday through Sunday. Heat and humidity returns Sunday night and Monday and so does the shower and thunderstorm chances through this period. A trough of low pressure will be the focal point of any convection Sunday night and Monday morning. A cold front that follows the trough will be the focal point of convection Monday afternoon and evening. Highs Friday through Sunday will be in the middle to upper 80s. Highs Monday should reach near 90 or the lower 90s. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... Widespread thunderstorms expected through 01Z, but showers could linger well into the overnight. Brief IFR/LIFR conditions are likely. Windshift is not expected until after 00Z. VFR conditions at all terminals Friday through Saturday night. Winds northwest around 5 knots becoming light and variable Friday into Friday night. Winds light becoming southeast 5 knots Saturday and Saturday night. && .MARINE... SCA conditions are possible across the middle and lower bay and south of Cobb Island. In addition, numerous thunderstorms are expected which may produce strong wind gusts in excess of 34 kt. SMWs may be required. Winds are expected to diminish Wed morning. No marine hazards Friday through Saturday night. Winds northwest 5 to 10 knots Friday and Friday night. Winds becoming southeast 5 to 10 knots Saturday and Saturday night. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...Flood Watch until 11 PM EDT this evening for DCZ001. MD...Flood Watch until 11 PM EDT this evening for MDZ003>006-008- 011-013-014-503>508. VA...Flood Watch until 11 PM EDT this evening for VAZ026>031- 038>040-051-053-054-501-502-505>507-526-527. WV...Flood Watch until 11 PM EDT this evening for WVZ050>053-055. MARINE...Flood Watch until 11 PM EDT this evening for ANZ530. Small Craft Advisory until 9 PM EDT this evening for ANZ532- 533-540>542. Small Craft Advisory until 6 AM EDT Wednesday for ANZ534-537- 543. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...KLW AVIATION...LFR/KLW MARINE...LFR/KLW