Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
967 FXUS61 KLWX 291346 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 946 AM EDT Tue Sep 29 2026 .WHAT HAS CHANGED... Added patchy drizzle along the MD/PA border as light rain showers track across the area. Otherwise, no major changes were made to the forecast. && .KEY MESSAGES... - 1) Tranquil weather is expected through Thursday with climbing temperatures. - 2) Well above normal temperatures continue through Friday, but forecast confidence decreases moving into the weekend as rain chances increase. && .DISCUSSION... KEY MESSAGE 1...Tranquil weather is expected through Thursday with climbing temperatures. What`s left of the Nor`easter is over the Gulf of Maine today, with cyclonic flow aloft still affecting the Mid Atlantic. A broad moisture shield around the low continues to bring clouds across the area, although several breaks and layers are noted on satellite and in observations. Some patchy fog could develop in any extended breaks (as seen at St. Inigoes MD). This moisture remains pretty consistent throughout the day, so mostly cloudy skies (with some breaks) will likely continue. While temperatures may be held back a few degrees, high temperatures should still reach the lower to mid 70s for most locations. Some models are printing spotty light QPF this afternoon as instability increases beneath the trough axis. However, moisture will be shallow, likely limiting any precipitation to sprinkles. Skies should clear some tonight as ridging builds in at the surface and aloft. This set up could be favorable for fog to develop, although the coverage remains somewhat uncertain at this time. Lows will be close to the dew points in the 50s. The surface high will move off the coast late Wednesday into Thursday while heights continue to increase. Temperatures will climb further, with more locations reaching the 80s. Some spots could even approach 90 by Thursday. Developing southerly flow will lead to more sunshine. Dry weather is expected both days. While nightly fog is possible, increasing southwesterly flow just above the surface may limit low level saturation. KEY MESSAGE 2...Well above normal normal temperatures continue through Friday, but forecast confidence decreases moving into the weekend as rain chances increase. Another day of well above normal temperatures is expected on Friday. 850 hPa temperatures of around 16-18C should yield high temperatures in the mid 80s to near 90 at lower elevations, and 70s in the mountains. Clouds will be on the increase through the day, and a few showers can`t be ruled out in western Maryland or the West Virginia Panhandle during the afternoon as a cold front approaches from the northwest. Guidance varies substantially from model to model and ensemble member to ensemble member regarding the positioning of this front through the upcoming weekend. With the frontal boundary in the vicinity, there will be at least some chance for showers either day this weekend, with ensemble guidance favoring higher chances on Sunday. Forecast uncertainty remains high however, with ensemble members showing high temperature solutions ranging from the upper 50s to low 90s Saturday, with cooler temperatures more likely by Sunday. The frontal zone is likely to clear the area by Monday, leaving below normal temperatures in its wake. && .AVIATION /13Z TUESDAY THROUGH SATURDAY/... Moisture wrapping around what`s left of the Nor`easter will continue to bring ceilings through today, although they will most likely remain VFR. The overcast is widespread enough that fog appears unlikely this morning, although a few patches could develop if there are any breaks before sunrise. Light northwest winds continue through the day. Added in a MVFR TEMPO at KMRB until 15Z with patchy drizzle bringing in lower ceilings. Clouds should break tonight with light winds forecast. That could result in fog, although coverage is uncertain. MRB and CHO would have higher chances of lower visibilities, but will play TAFs conservatively now until confidence increases. VFR conditions will continue Wednesday and Thursday as high pressure passes, with light winds turning southerly. Fog looks a little less likely Wednesday and Thursday nights but can`t be ruled out. VFR conditions and southwesterly winds are expected on Friday. Depending on the positioning of a front, sub-VFR conditions could be possible on Saturday, but forecast confidence during that time period remains low. && .MARINE... High pressure moving toward the area will provide light winds through Wednesday. A northwesterly direction today will turn southerly on Wednesday. Southerly winds begin to pick up in strength on Thursday, with some channeling effects possibly bringing gusts to near 20 knots over the Chesapeake Thursday night. Sub-SCA level winds are expected on Friday in south to southwesterly flow. Winds are currently forecast to shift to out of the northeast on Saturday, but forecast confidence remains low with a frontal boundary nearby. SCA conditions are possible depending on the frontal position. && .TIDES/COASTAL FLOODING... Some uncertainty exists for the remainder of the week as tide levels remain elevated. Any subtle shifts upward could result in minor flooding, particularly at Annapolis. However, Alexandria, Dahlgren, and Havre de Grace may also be close at times. Minor flooding could occur as soon as this evening`s high tide. Evening tides would be favored going forward as well since they are astronomically higher. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ DISCUSSION...ADS/AVS/KJP AVIATION...ADS/KJP MARINE...ADS/KJP