Forecast Discussion
Summary
SYNOPSIS
... A backdoor cold front will meander over the region through tonight before lifting northward as a warm front on Saturday. Low pressure will track from the Mississippi Valley toward the Great Lakes Friday night into Saturday. The cold front attached to this system will push through later Saturday into Saturday night. High pressure will build overhead on Sunday, before the next disturbance approaches the area early next week.
NEAR TERM /THROUGH TONIGHT/... Showers are overspreading the region generally from NW to SE as a backdoor cold front drops into the region. Cooler temperatures are starting to creep into northwestern zones and will gradually move southeast this morning. Still seeing some 60s to near 70 the further south and east you go. Rain coverage will be on the increase throughout the morning as the front becomes further entrenched into the area. This will also continue to bring temperatures down throughout the day, resulting in a much less pleasant day than we have seen recently.
Rain chances continue into tonight as the frontal boundary remains stalled somewhere over the region. Showers become a bit more sporadic at times tonight. Low temperatures will only dip into the 40s though.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... An embedded shortwave within a broad upper trough is expected to move into the Midwest and the Great Lakes on Saturday. A strong area of low pressure will slide by to our northwest during this time. Meanwhile, the stalled frontal boundary that had plagued the region for a couple of days will finally advance northward as a strong warm front. The primary cold front associated with the aforementioned low will bring more rain showers, and possibly a few thunderstorms. Thunderstorm chances will be dependent on how quickly, or if, the cold air wedge clears out. If thunderstorm activity isn't suppressed, there is the potential for some gusty winds, owing to some decent CAPE and an impressive 60 kts of shear. High temperatures will be dependent on the timing of wedge breaking, and have actually come down a few degrees for our northern and northwestern zones. Elsewhere, kept things mostly the same as they should break out of the wedge and reach into the 60s.
High pressure will build across the region Sunday. Winds will actually be out of the west, so there is a good chance we could get pretty warm and dry on Sunday. Winds could gust in the 15-20 mph range at times during the afternoon hours. The best overlap of dry conditions and gusty winds is actually going to be right where we should see the most rain in the coming days, so not seeing any fire weather concerns for this period.
LONG TERM /MONDAY THROUGH THURSDAY/... Zonal flow aloft is forecast to develop across the Mid-Atlantic for the first half of next week as several perturbations traverse the area. Dry conditions are expected Monday as a weak surface high slides by to our north. This is followed by a strong shortwave trough quickly moving from the Midwest to the Mid-Atlantic Tuesday into Tuesday night. A weak surface low that develops over the eastern OH valley slides northeast into western PA Tuesday night. An associated cold front sweeps through our area Tuesday afternoon into Tuesday night. We could see a few showers develop ahead of the front early Tuesday, however the best chance for rain looks to be Tuesday afternoon and evening as the front moves through.
A large surface high builds across the region Wednesday, then slides off the Carolina coast on Thursday. Dry conditions are forecast on Wednesday, with mostly dry and breezy conditions for Thursday.
High temperatures next week are forecast to be near normal for most of the week - in the mid 50s to low 60s, except for 40s along the Allegheny Front. The warmest day looks to be Monday where most areas reach the low to mid 60s. It is a similar story for overnight lows that are forecast to range from the mid 30s to lower 40s. The Alleghenies could see below freezing temps Tuesday and Wednesday nights.