Pittsburgh residents can expect a shift from today's dry and seasonal conditions to a dreary cycle of rain and chilly temperatures beginning Wednesday evening and persisting through the week, the National Weather Service in Pittsburgh reported. The weather pivot is attributed to an upper-level low and surface cyclogenesis occurring near the western Tennessee River basin, steering Pittsburgh under the influence of northeasterly high pressure for now. Pittsburgh will feel cooler than usual today thanks to a breezy easterly wind that might gust up to 20-25 mph.
As we head into the night, the sky should stay mostly clear, but easterly winds will persist. There's a chance for areas of frost to develop in the northwest (favoring valley locations), but only in spots where the surface wind settles down. The forecast for Wednesday through Thursday night foresees a damp outlook, with widespread rain taking over after a dry start to Wednesday and temperatures continuing to dip below the norm. Despite variances in forecasts, localized rainfall could exceed 1 inch in some areas, especially along the West Virginia ridges, where the probability of flooding could become an issue due to saturated grounds or drainage clogs from fall foliage, according to a forecast discussion from the National Weather Service.
Looking towards the weekend, the National Weather Service suggests lingering showers in northwestern PA and the higher elevations could be in store, with a low probability of snowfall where temperatures flirt with the freezing mark. A brief respite might arrive Saturday with shortwave ridging offering a short-lived dry and warmer period. However, a weather pattern with periodic precipitation and near to below-average temperatures might extend into early next week.
For aviation interests, VFR conditions are expected to be maintained through Tuesday night, with high clouds the only concern and easterly winds keeping fog at bay. By midday Tuesday, wind could become gustier and reach peaks of 15-20 knots in the afternoon. The impending weather system on Wednesday could bring about rain and restrictions, with increasingly likely restrictions for Thursday and Friday, along with breezy conditions as a surface low-pressure system passes to the south.
