Weather blog
W/Trey blog
09-10-2026 PM WEATHER
Key Points:
-Additional showers/storms this evening and overnight, esp. Southern counties
-Drier, comfortable Friday
-Non-severe storms, but locally heavy rainfall possible Saturday.
-Isolated to scattered storms Sunday evening with cold front, low severe risk.
-Dry start next week, but warm & humid with storms possible mid-late week.
Forecast Discussion:
Parts of the Pittsburgh metro received between 1-3" of rain with Wednesday night's storms. 1.06" fell at the airport bringing the monthly total to 3.55" and the annual total to 37.17". This is the 5th wettest January 1-September 9th on record.
This afternoon, skies are mostly cloudy and will continue to remain that way as most of the forecast area remains within a very moist air mass ahead of the cold front currently dropping south from the Lower Great Lakes. A disturbance moving embedded within the mid to upper-level flow across the Midwest States will move east passing over Western PA late tonight into Friday morning. This will result in increasing chances for showers and possibly a few thunderstorms this evening—mainly from the I-70 corridor and points south. These will continue through the overnight hours, especially across far Southwest PA into Northern WV before some clearing on Friday morning. As the cold front continues to move south, a drier and comfortable air mass will move in for the rest of Friday, leaving most of the region with partly cloudy skies and temperatures peaking between 75F-80F.
This cold front will not make much southward progress and actually start to lift north by early Saturday morning turning into a warm front. This will allow a very humid air mass to be in place for most of our forecast area on Saturday. Precipitable water or atmospheric moisture values will be near record-breaking levels for this time of year. A weak disturbance moving northeast from the Ohio River Valley will provide the forcing to trigger showers and scattered storms from midday through late evening Saturday. As of now, I believe the highest coverage of rainfall will occur mainly from the Pittsburgh metro and east & south into the Laurel Highlands and Northern WV as this is where the greatest moisture advection and strongest forcing from the disturbance will occur. Severe weather is not a major concern for Saturday as the winds aloft will be weak leaving us with a weakly sheared environment and favoring more disorganized storms. Flash flooding is possible, especially for areas that receive repeated rounds of heavy rainfall.
This system will exit Saturday night into Sunday morning. While precipitation chances drop off temporarily for Sunday morning through early afternoon, it will likely remain humid ahead of a southward moving cold front and strong core of jet stream energy. As the cold front moves south, isolated to scattered storms are likely to develop Sunday late-afternoon and evening. Instability values will be higher and the stronger winds aloft will be stronger so a severe storm cannot be ruled out. One caveat may be a lack of convergence along the cold front which would lead to less storm development, but still worth watching.
Drier and slightly cooler air make a return on Monday, but a hot and humid air mass looks to return by Tuesday and Wednesday. This will be in advance of several disturbances and a slow-moving front that will increase storm chances with possible severe weather by Wednesday and Thursday next week.
