September Pennsylvania Weather Summary

 

            From September 1-4, high pressure dominated the weather until a cold front passed on September 4.  Temperatures ranged from near 80s-lower 90s before the passage.  This front brought a few sprinkles across Pennsylvania associated with its passage and a relief from the unseasonably warm temperatures.  September 5 brought another high pressure system and temperatures ranged from the upper 70s-low 80s.  This system dominated the weather until September 10 when a cold front made it into Pennsylvania. Temperatures stayed in the mid-upper 80s until its passage. This frontal system sped through the Mid-West, but stalled over Pennsylvania because of a tropical storm off the coast.  This combination brought a few sprinkles to Pennsylvania, but temperatures were still unseasonably warm.  This front moved out with the tropical storm on September 12.  High pressure on September 13 and 14 brought a break to the rain with warm temperatures ranging from mid-80s to near 90s continuing. 

 

Inevitably, light rain occurred across Pennsylvania on September 15 due to a front passing and a return to temperatures near 80s was reached throughout the Commonwealth.  A high pressure system moved into the Northeast and across Pennsylvania on September 17 and stuck around until September 20.  This brought a return to temperatures in the mid-upper 80s. 

 

One frontal system passed through September 21 after the strong high pressure evacuated the area bringing some light showers and temperatures in the mid-70s.  Another front followed overnight, but it was weak since cooler air was already in place from the frontal passage the day before.  A weak high took its place on the 23, but a low came through on the 24, but it did not bring any rain to the area.  So high pressure took it's place yet again from the 25-26 until Tropical Storm Isidore traveled through the eastern coastal states up into Pennsylvania and the New England states during the 26 through the 27.  The rain totals throughout the state were approximately two inches with temperatures dipping into the low-60s. This system stuck around until the high pressure in the Atlantic let the low, previously Tropical Storm Isidore, move out of the Eastern United States.  Strong high pressure moved into the area from the 28 into next month warming the Commonwealth back into the mid-70s.