Severe weather chances remain throughout the day Friday in Pittsburgh
Isolated to scattered severe storms are possible in western Pennsylvania on Friday ahead of a cooldown.
There was a severe thunderstorm watch for most of the Pittsburgh area, but it's been canceled. The watch remains in effect for Venango, Clarion, Forest and Jefferson counties until 10 p.m.
A tornado warning was issued for parts of Washington and Greene counties, but it expired at 3:15 p.m.
The biggest change in the Pittsburgh area's forecast for Friday has been the addition of scattered strong to severe storms for the afternoon and early evening hours. This is mainly due to the fact that overnight storms were not as widespread as originally expected, and now areas from Route 422 and points southwest through Pittsburgh into northern West Virginia are able to build up more "fuel" since none was used in these areas last night or this morning.
Where and when will severe storms happen Friday?
Clouds are already showing signs of towering and attempting to form storms just northwest of Pittsburgh from Beaver County east through Armstrong County. Areas between Route 422 and I-70 will likely be the hotspot for any isolated to widely scattered storms Friday afternoon.
Should any of these cells form and maintain their strength, large hail and damaging downburst winds would occur. The peak time for this afternoon's risk will be between 2 p.m. and 9 p.m.
Severe storms could hit again overnight
Overnight, things become a bit more complex and very conditional. A severe weather outbreak will likely be ongoing in Illinois, Indiana and Kentucky. These storms will likely form a large squall line and move east in the direction of western Pennsylvania after midnight and into the predawn hours of Saturday.
While the Pittsburgh area will have the lift and jet stream energy to support storms, the crucial ingredients of moisture and instability may be missing due to outflow winds from storms ongoing Friday afternoon in Kentucky and West Virginia and any storms that may develop in western Pennsylvania during the late afternoon or early evening hours of Friday. This would cause a lot of the storms to lose their potency and drop below severe limits.
Bottom line: the more activity the Pittsburgh area sees Friday afternoon/evening, the less intense the overnight round will be and vice versa.
Cold front moves through Saturday
Saturday begins with a few remnant showers, then some isolated showers and storms may develop by midday to early afternoon as the cold front moves through. It will be windy as well with gusts upwards of 35 mph during the midday to midafternoon time frame.
A cooler and drier air mass looks to settle in by Sunday and will stick with us through the middle of next week. The next wave of low pressure to bring rain and storm chances does not appear to arrive until Wednesday next week with a chilly air mass for late May standards.
