July 2002 Pennsylvania Weather Summary

First Week (July 1-7)

July began with a high-pressure system dominating the weather for much of the Eastern U.S. Much of Pennsylvania was in the westerly flow on the northern edge of the high, resulting in a mild and short-lived heat wave. Most locations topped 90 degrees for three straight days from July 2nd to July 4th. A cold front passed through on the 5th relatively dry and brought cooler air to the region. This front washed out over the Gulf-Coast states and brought relief from the heat for heat for the weekend.

Week 2 (July 8-14)

The high-pressure system that followed the frontal passage on the 5th settled over the Atlantic Ocean, bringing a moist southerly flow to the area through the 8th and 9th.and a few more warm days. Another front quickly approached from the north, producing more widespread rain then the previous week. Afterward, a large high nudged its way over Pennsylvania, providing several beautiful mid July days, with temperatures holding in the middle to upper 70’s across the Commonwealth. The week ended with a minor disturbance bringing showers and storms to the region, which quickly passed off to the East.

Week 3 (July 15-21)

A weakening cold front draped over the central portion of the state to open the week. A Low Pressure system in central Canada moved WSW and passed through the northern Great Lakes region, keeping Pennsylvania in a warm to hot temperature regime. Temperatures remained above 90 degrees F for upwards of five straight days in the southeastern counties, which is a note-worthy event that hasn’t happened for years. A cold front finally managed to pass through on the 20th, easing the heat and bringing at least a half inch of rain to a majority of the state. The front washed out just to the south and heat quickly returned.

Week 4 (July 22-31)

The first two days were more 90-degree days. However, a strong cold front scoured the heat from much of the Midwest and worked its way eastward. Pennsylvania received showers and storms from this front as it draped itself across the Ohio Valley and Mid-Atlantic states. Clouds and showers kept most of the state in the 80’s for most of the week, as frontal foundries meandered across the region. Rain events were generally light and widely separated in nature. This boundary finally passed to the north as a warm front into round out the month with yet another bout of widespread 90-degree days.

Summary

The Commonwealth of Pennsylvania saw wild temperature variations throughout July 2002. Most of the month was on the warm side however, with lots of widespread 90-degree days. It did have its share of beautiful “Sunny and 70” days as well. Precipitation was generally weak everywhere. Most of the rain events were not significant and were too wide spread to completely put away the weakening drought that has been around for months. Locations that received more than 3 inches of rain were extremely lucky. For the most part, all areas received around an inch and a half of precipitation.

-Dan Swank

July 2002 Pennsylvania Extremes