


Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
269 FXUS61 KLWX 011914 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 314 PM EDT Mon Sep 1 2025 .SYNOPSIS... Surface high pressure centered to the north slowly drifts eastward through midweek. A low pressure system and associated cold front tracks towards the forecast area from the Great Lakes region Wednesday before moving through on Thursday. A secondary cold front moves through Thursday night and into Friday morning. High pressure returns for the weekend. && .NEAR TERM /THROUGH TONIGHT/... Mostly sunny skies can be observed across the forecast area as fair weather cumulus clouds overspread the region. Northeast winds gusting of 15 to 20 mph diminish this evening as temperatures begin to cool down. Highs will be in the mid 70s to near 80 as high pressure remains centered to the north. With the loss of daytime heating, cloud cover is expected to diminish with mostly clear skies. Overnight low temperatures will be 50s-60s for most with only this at highest elevations dipping into the 40s. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Conditions remain dry for most on Tuesday as surface high pressure remains overhead. Shortwave energy pivoting aloft will bring a slight chance of precip to those in southern Maryland and along the Chesapeake Bay. Dry air will inhibit most precipitation, but an isolated shower cannot be ruled out. Temperatures remain below normal with highs forecast in the 70s for most. Those in the metro areas may rise into the low 80s while those at higher elevations stay in the upper 80s. Overnight low temperatures Tuesday into Wednesday will be in the 50s across most of the area with only those in the metros staying in the 60s. On Wednesday, surface high pressure shifts offshore bringing a change in wind direction as wind shifts southerly. This will usher in moisture leading to increasing cloud cover, dew points, and precipitation chances. A shortwave trough aloft will bring a slight chance to a chance of rain showers to areas west of the Blue Ridge in the afternoon with surface high pressure keeping the rest of the area dry. Temperatures warm slightly with more areas east of the Blue Ridge reaching the low 80s. && .LONG TERM /THURSDAY THROUGH SUNDAY/... An anomalous upper low centered south of Hudson Bay will wobble eastward on Thursday and Friday before accelerating off to the east thereafter. As this system translates eastward, a series of embedded shortwaves are expected to swing through the Great Lakes and northeastern U.S. The overall trajectory of these impulses largely graze the area with stronger height falls closer to the international border with Canada. The day-to-day model trends have been showing a slower progression of the cold air that arrives behind the synoptic-scale trough. However, this reinforcing shot of cooler air does make it into the area by late in the weekend into next Monday. The best chance for any showers and thunderstorms would be Thursday afternoon/evening with the approach of a cold front. While not necessarily providing much of a drop off in temperature, it does enhance low-level convergence. Instability is modest at best which should temper a larger scale thunderstorm threat. However, a few of the more robust updrafts could become strong to severe in nature. This boundary eventually slides east of the area by early Friday. As mentioned, any temperature falls do not really take shape until the secondary surge over the weekend. Spotty showers may also accompany this trailing cold front that tracks through on Saturday. While high temperatures should be in the upper 70s to mid 80s through Saturday, temperatures fall back down into the mid/upper 70s to finish out the period. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions continue today as high pressure remains overhead. Fair weather cumulus clouds will remain across all terminals this afternoon with cloud cover forecast to diminish overnight. Northeast wings gusting around 15 knots continue this afternoon before decreasing this evening. Patchy fog is possible tonight, mainly at CHO and MRB where low level moisture is greatest. Light winds out of the northeast are expected on Tuesday, blowing 5 to 10 knots in the afternoon. Winds become light and variable overnight before shifting to southerly on Wednesday as high pressure shifts offshore. VFR conditions continue Wednesday as winds gust 5 to 10 knots. With a threat of showers and thunderstorms on Thursday, some afternoon/evening restrictions are possible at all TAF sites. Initial winds ahead of the cold front will be out of the south and gust up to 20 to 25 knots. The boundary pushes off to the east late Thursday with winds turning more southwesterly. A secondary cold front moves through on Saturday which could bring a few showers with it. Otherwise VFR conditions are expected on Friday into Saturday with winds shifting to westerly behind this next frontal system. && .MARINE... Northeast winds continue across the waters this afternoon, gusting around 15 knots. Winds diminish overnight and are expected to remain light on Tuesday, gusting less than 10 knots. On Wednesday, high pressure shifts offshore and winds shift to southerly. Winds gust around 10 knots in the Chesapeake Bay Wednesday afternoon. Winds remain below SCA criteria through midweek with no other marine hazards expected. Ahead of a cold front, southerly channeling will likely increase gusts over the waters on Thursday. Small Craft Advisories may be required Thursday afternoon into Thursday night. Showers and thunderstorms accompany the front that moves through. Cannot rule out a Special Marine Warning or two for any of the more potent cells. Behind the front, winds generally remain out of the south to southwest. Winds could approach advisory levels at times on Friday. && .TIDES/COASTAL FLOODING... Water levels may fluctuate a bit through Tuesday as northeasterly to easterly winds fluctuate in strength. Annapolis may come close to reaching minor flood stage by tonight`s and Tuesday night`s high tide, but confidence is low. A flip to southerly flow Wednesday should allow for further rises in water levels. Confidence in Annapolis reaching minor flood increases Wednesday night. Peak water anomalies appear to occur Thursday night ahead of a front. More locations may reach minor flood, and some guidance has Annapolis approaching moderate flood. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...AVS NEAR TERM...AVS SHORT TERM...AVS LONG TERM...BRO AVIATION...AVS/BRO MARINE...AVS/BRO TIDES/COASTAL FLOODING...ADS