Weather Outlook

Posted: June 26, 2012

A warming trend will began on Wednesday and it should lead to a spell of uncomfortably warm, humid conditions from Thursday into the first half of next week. The boundary with mild, dry air to the north will waver across parts of Pennsylvania during this period leading to several opportunities for thunderstorms.

The first risk could come as early as Friday morning as a cluster of storms from the Midwest descend and dissipate over the western and southern counties. Afternoon thunderstorms are expected each day from Friday through next Tuesday, and the most widespread storms are expected on either Sunday or Monday as a puff of a Canadian air mass attempts to bring temporary relief to the region. Most days will see readings from the low-mid 80’s in the northern tier to low-mid 90’s in the southern counties. Nights will stay quite warm with readings between 65-75F. During the next week, the vast majority of the state should receive a modest amount of rain, 0.10-0.50”. A few places could miss all the rain, and some spots (about 15% of the region) will get more than 1”. Evaporation rates will be quite high, despite the increased humidity.

The longer range outlook points toward a spell of hot weather during the first half of July with below average rainfall. Odds still favor a turn to cooler conditions in August, perhaps accompanied by more widespread rain. Despite the early onset of tropical storms, their effects on Pennsylvania in 2012 are likely to be small. Conditions in the tropical Pacific are turning toward an expected El Nino (weak to moderate) for the winter of 2012-2013. This would favor notably cooler and snowier conditions compared with 2011-2012.

Contact Information

Paul Knight
  • Pennsylvania State Climatologist