021 FXUS61 KLWX 110134 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 934 PM EDT Thu Apr 10 2025 .SYNOPSIS... An upper level low will slowly pivot across the east coast through the end of the week, bringing multiple rounds of rain to the forecast area. On Saturday, the area of low pressure shifts offshore as surface high pressure, located over the Ohio River Valley, builds in from the west. Dry conditions and warming temperatures are expected beginning Sunday, ahead of a cold front moving through the area Tuesday into Wednesday. && .NEAR TERM /THROUGH FRIDAY/... Broad upper troughing continues to dig across the Eastern US this evening, with a weak lead shortwave tracking northeastward toward Lake Erie, and a much stronger shortwave tracking southeastward into the base of the trough over the Tennessee Valley. As we progress through the night, the southern shortwave will continue to dig, and will eventually close off into an upper low over the southern Appalachians. Showers are ongoing across the area this evening within weak low-level warm advection downstream of the approaching longwave trough. On and off showers will continue through the night, especially to the east of the Blue Ridge. Pockets of drizzle may also be possible. Temperatures will only drop a few degrees over the course of the night, with overnight lows generally in the 40s. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... As the aforementioned low pressure system tracks north from the Carolinas, widespread showers are expected throughout the day on Friday. WPC has the southern portions of the area and those along and east of I-95 in a marginal risk for excessive rain with QPF totals nearing 1.5" in those areas. That being said, persistent drought conditions across the area will likely lead to this being a beneficial rainfall event. Highest totals will be in the metro areas with those west of the Blue Ridge seeing the least amount of rain. As temperatures fall overnight Friday into Saturday, rain may mix with snow in the mountains. Outside of the highest ridgetops in the Alleghenies, rain will be the dominant precipitation type. On Saturday, precipitation chances linger as a low pressure system departs off the MD/DE coast. Conditions dry out initially in the Shenadoah Valley with low end (30%) chance of precipitation lingering through the afternoon elsewhere. High pressure builds in over the Mid-Atlantic from the west with dry conditions and decreasing cloud cover expected overnight. High temperatures on Saturday will be in the 40s to mid 50s with overnight low temperatures in the 30s and 40s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... A slow moving amplified upper level pattern will continue into next week. The first trough will be moving off the coast Sunday, which should result in clearing skies and warmer (seasonable) temperatures compared to Saturday. There are some hints that warm advection aloft could result in a brief chance of light showers or sprinkles Sunday night. High pressure to the south should gain enough influence on Monday for temperatures to warm further into the 60s and 70s. The next trough will be evolving into a closed low across the northern Great Lakes by late Monday. A cold front trailing the associated surface low will push east into the area Monday night. With weakening/glancing forcing and westerly flow, there will likely be a tendency for showers and isolated thunderstorms to fall apart as they cross the mountains. A couple secondary fronts may cross the area Tuesday into Tuesday night. Precipitation with these boundaries will likely be limited to upslope areas of the Allegheny Front. This precipitation could change over to snow as temperatures fall. Temperatures will likely return closer to normal Tuesday, then fall below normal Wednesday. Wednesday night looks like the coldest of the stretch, when some areas could fall below freezing. Winds will also become gusty Tuesday through Wednesday due to the pressure gradient tightening as the surface low moves along the St. Lawrence Valley. Surface high pressure will likely build in by Thursday. Temperatures will remain near to slightly below normal. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/... Ceilings are starting to drop this evening, but most locations remain VFR. Drops to MVFR, and then eventually IFR to LIFR ceilings are expected over the course of the night. On and off showers, along with pockets of drizzle will also be possible over the course of the night. Widespread rain will impact all terminals beginning Friday morning, with IFR to LIFR CIGs expected. Rain will continue throughout the day. NE winds gust up to 15 knots. Sub-VFR conditions linger on Saturday as precipitation slowly exits the region. Conditions improve to VFR Saturday night as conditions dry out. NW winds on Saturday blow 5 to 10 knots and gust around 15 knots. VFR conditions likely prevail Sunday through Tuesday, although there is a low chance of rain showers Monday night. Northwest winds may gust to 20 kt Sunday, followed by lighter south winds Monday. West winds increase behind a cold front early Tuesday, potentially gusting to around 30 kt. && .MARINE... SCA conditions continue through this evening for all waters with southeast winds gusting up to 20 knots. While winds diminish later this evening for the upper waters, SCA conditions linger through the overnight for the lower portions of the waters. SCA conditions possibly continue Friday and Saturday as a low pressure system tracks nearby. Winds will be out of the N/NW, gusting 15 to 20 knots over the waters. SCA conditions in NW flow may linger into Sunday. Lighter winds are expected Sunday night into Monday as high pressure builds into the area, with direction becoming southerly. A cold front will push through Monday night, with strong westerly winds developing in its wake. SCAs are likely, and gusts could approach gale force. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Small Craft Advisory until 11 PM EDT this evening for MDZ008. VA...None. WV...None. MARINE...Small Craft Advisory until 11 PM EDT this evening for ANZ530- 531-535-536-538-539. Small Craft Advisory until 5 AM EDT Friday for ANZ532>534-537- 540>543. && $$ SYNOPSIS...AVS NEAR TERM...KJP SHORT TERM...AVS LONG TERM...ADS AVIATION...ADS/AVS/KJP MARINE...ADS/AVS