According to the National Weather Service, Pittsburgh residents can look forward to mostly dry and warm conditions today and Saturday. With high pressure moving south, clear skies and seasonable temperature are on today's weather menu, providing a brief spell of respite following the chilly start this morning that saw patchy frost and robust river valley fog, which are expected to dissipate shortly. "Surface high pressure drifts south across the region," reported the National Weather Service, signaling a day of calm before the approaching upper-level trough, which is set to shake things up come Sunday.
While tonight's forecast sees a continuation of the fair weather with increased cirrus clouds due to an upper-level trough and elevated surface winds keeping frost at bay, the narrative shifts for the weekend. A weak shortwave and an anemic cold front will bring increasing clouds on Saturday, but the absence of substantial moisture and lift along the front means that rain is not expected to mar the stretch of pleasant skies. "Minimal to no precip chances are expected with a lack of moisture and lift along the front," the National Weather Service detailed in their report.
Rain showers, however, are poised to sneak back into the forecast late Saturday night into Sunday as a surface low pressure develops and pulls a warm front northward across the region. Residents north of Pittsburgh are more likely to need their umbrellas, with lesser chances of rainfall to the south. This low-pressure system will also pave the way for showers and possibly thunderstorms on Sunday, fueled by an incoming jet aloft that could amplify the showers and the potential for strong storms. Winds could also get gusty, especially with stronger weather activity. Model ensembles hint at some storms being potent enough to be labeled "strong" south of the surface low's track.
The weather promises to stay interesting with cooler temperatures, gusty wind, and showers expected Sunday night, as the National Weather Service indicates. The early part of next week doesn't look to break the unsettled trend either, as a longwave trough digs its heels across the Eastern U.S. The trough-induced cold northwest flow off of the Great Lakes and rotating shortwaves will likely pepper the Ohio Valley with scattered showers until Wednesday. Aviation should remain VFR today, but the changing conditions suggest increased rain chances and potential restrictions come Sunday, so travelers should be prepared for periodic disturbances from the sky.
