... A series of weak troughs and fronts will rotate around Canadian low pressure through Wednesday. High pressure will build north of the area Thursday and Friday.
NEAR TERM /UNTIL 7 AM TUESDAY MORNING/... Light showers over parts of western and northern MD have earlier this evening have now dissipated. Mostly dry conditions are expected through the overnight. Dense cirrus has developed off the mountains, as some of the model guidance was suggesting earlier. This should maintain mostly cloudy skies overnight. Lows will be in the mid 40s to mid 50s.
SHORT TERM /7 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... Within the persistent cyclonic flow regime, various shortwave troughs and secondary/reinforcing surface boundaries will cross the area through the middle of the week. Prevailing west- northwesterly flow ensues through mid-week, becoming occasionally breezy during each afternoon. This pattern will favor the most clouds in the upslope regions, but daily cumulus will form areawide. The greatest chance for showers will be Tuesday and Wednesday afternoons near and west of the Allegheny Front. Cold advection will bring temperatures below normal, with highs in the mid 60s to lower 70s (50s in the higher elevations) and lows in the 40s to near 50.
LONG TERM /THURSDAY THROUGH MONDAY/... Thursday and Friday will be dry and slightly below average as a strong 1030+ mb high pressure system drops south out of Canada and sets up over New England. A very chilly morning is expected on Friday across the area, with perhaps some patchy frost in the valleys along the the higher terrain.
For next weekend, that is where forecast uncertainty greatly increases over our area. Hurricane Ian is forecast to move into the southeast this weekend after landfall somewhere along the eastern Gulf Coast. What Ian does from there is still quite uncertain in terms of the when and where. Some impacts from whatever is left of Ian are possible this weekend though, so monitor the latest forecast for Ian from the National Hurricane Center with more details at hurricanes.gov.