Latest Forecast

West-to-southwesterly flow on the backside of a high pressure system over the southeastern United States and western Atlantic will usher hotter air into the mid-Atlantic States through the start of the weekend. Under mostly sunny skies, high temperatures will reach the mid- to-upper across the Lower Susquehanna Valley this afternoon and upper 80s to low 90s on Friday. Fortunately, humidity will remain low with dewpoints in the 50s. Due to light winds and the dry air mass in place, tonight will still be comfortable with lows in the mid-to-upper 50s. The large-scale subsidence, or sinking motion, associated with the high will also prevent shower and thunderstorm formation through at least early Saturday afternoon. Southwesterly winds of 12-25 mph will pump somewhat more humid air into the region on Saturday, but dewpoints still should not exceed the low 60s during the afternoon hours. Much like Friday, high temperatures on Saturday will generally be in the low 90s across southeastern PA.