June 2001 Climate Summary

The month of June finally brought an end to the drought that encompassed the Commonwealth during April and May. Storm systems traversed Pennsylvania on a somewhat regular basis, and with tropical air in place, this set the stage for periodic heavy rains. However, unlike May, most days were not completely washed out and rain and thunderstorms were fueled in part by the daytime heating. The rain busted the drought that had gripped the central and eastern parts of the Commonwealth this year to date.

The first few days of June featured generally mostly cloudy skies with several periods of rain each day. This was due to a slow moving upper-level low that moved across the northeast, which caused several surface systems to advance across the Commonwealth. High temperatures remained well below normal for the week, and were 10 to 15 degrees below normal on the 3^rd. Rainfall amounts were generally a half inch or less each day, but heavier rains did affect eastern areas on the 2^nd and 3^rd.

By the time the first full week of the month arrived, the pesky storm system had settled further to the south as high pressure nosed down from central Canada. This provided a brief respite from the clouds until midweek, when a stationary front to our south crept northward. While only the southern tier received rain this go-around, the Commonwealth as a whole dealt with the clouds and below normal temperatures yet again. By Friday the 8^th, stronger high pressure moved down from Canada, pushing the frontal system all the way into the Deep South. Skies finally cleared, yielding a sunny weekend.

The week of the 11^th saw the first above normal temperatures across the Commonwealth in a few weeks. It was very active as well. A weak front settled across the state on Tuesday and Wednesday, providing mainly scattered showers and thunderstorms to the region. Severe thunderstorms ripped across Pennsylvania Tuesday afternoon and evening. Wind damage was reported in Centre, Clinton, and Huntingdon counties to name a few. The front roared back north of Pennsylvania as a warm front overnight Wednesday, allowing temperatures to soar to near 90 degrees Thursday the 14^th through Saturday the 16^th. A slow moving cold front to our west allowed tropical air to be transported northward from the Gulf of Mexico. This made these the 3 hottest and most humid days of the year to date. On the 16^th, the slow moving cold front moved across the state, and combined with tropical moisture from the remnants of Tropical Storm Allison that were moving up the East Coast. Widespread heavy rains and embedded thunderstorms affected central parts of the Commonwealth on Saturday, and eastern portions Saturday night and Sunday morning. State College received 2.02" of rain in just one hour, and event rainfall totals ranged from 2-4" across the Central and Northern Mountains to as much as 8-10" across the southeast.

High pressure moved into the region behind this system, dominating the weather into Tuesday the 19^th. Temperatures were slightly above normal with highs in the 80’s. By midweek a trough started to dig southward. This allowed a cold front to move into the Commonwealth. Highs soared to between 85 and 90 degrees on both Wednesday and Thursday. Scattered thunderstorms each day brought generally less than 0.5" of rain to some areas. The front slowed its progress across PA into the weekend. Cloudy skies and periods of rain and thunderstorms kept conditions much cooler than they had been. Up to 6" of rain fell in localized parts of the Susquehanna Valley. The storm system finally moved off the east coast by the 24^th, allowing cool high pressure to bring back tranquil weather.

High pressure moved south-eastward from the Great Lakes to off the North Carolina coast during the week of the 25^th. Temperatures which began below normal levels at the beginning of the week soared into the upper 80’s to near 90 degrees by Wednesday the 27^th. In addition, high humidity levels made it feel just like summer should. The warmth peaked with a high of 94 in Philadelphia on Friday the 29^th. A weak trough brought spotty thunderstorms to the region on the last day of the month.

Out of the last 107 years, June ranked 53^rd for temperature, or near normal. For precipitation, June ranked 70^th, or slightly above normal. Finally, however, we were able to get into a summer-like weather pattern, at least for a short while.

Highest Temp: 100 at York Haven Hydrological Station on the 27^th.

Lowest Temp: 28 at Kane 1 NNE on the 1^st.

Maximum Precip: 8.21" at Southampton.

Minimum Precip: 1.55" at Altoona.