Pittsburgh, Pennsylvania — Light rain will move across western Pennsylvania and northern West Virginia Saturday afternoon, creating slick conditions before temperatures drop sharply overnight, setting up frost that could damage vegetation and impact early Sunday travel.
According to the National Weather Service in Pittsburgh, scattered showers will develop between noon and 6 p.m. Saturday, with the steadiest rain from 2 p.m. to 5 p.m. across Pittsburgh, Wheeling, Morgantown, Zanesville and Butler. Rainfall will be light, but enough to create wet pavement and reduced visibility along I-79, I-70 and I-376 during peak weekend travel hours.
By late evening, skies begin to clear and temperatures fall into the low to mid 30s by 2 a.m. Sunday. The coldest window runs from 3 a.m. to 7 a.m., when frost formation becomes likely in low-lying areas, including river valleys and rural spots near Washington and Beaver. Moist ground from earlier showers may accelerate frost development on bridges and untreated surfaces.
This is part of a broader system bringing cool air into the Upper Ohio Valley, allowing rapid overnight cooling once clouds exit.
Residents should slow down on wet roads Saturday, then cover sensitive plants and avoid early morning travel on untreated routes where frost may develop.
The highest combined risk shifts from slick roads Saturday afternoon to frost formation between 3 a.m. and 7 a.m. Sunday, when temperatures bottom out and surfaces can turn slippery.
