A macroburst roared across eastern Allegheny and extreme western Westmoreland counties during the early evening hours of May 31st.  This macroburst produced an approximately 10-mile long path of damage from the straight-line winds, which were estimated as high as 105 MPH.  The macroburst damage path originated in the Homestead area of eastern Allegheny County, with the outflow winds traveling to the southeast through the towns of Whitaker, West Mifflin and Duquesne.  The macroburst outflow then continued across the Monongahela River into the towns of McKeesport and North Versailles.  Outflow winds from this macroburst continued to the southeast, weakening as it crossed into Westmoreland County, where it produced damage in several communities in North Huntington Township.  By this time, the winds had decreased significantly, but were still strong enough to down numerous trees and power lines across the area.  The maximum width of this macroburst was estimated at 3 miles as it traveled through the Munhall area.  The highest concentrated area of damage extended from the Whitaker area to West Mifflin, where major damage occurred at the Kennywood Amusement Park.  A large wooden pavilion which housed the "Whip" ride collapsed.  As the pavilion collapsed it killed one person and injured 47 others.  Just across the street from Kennywood, several homes sustained major damage from the winds as roofs were blown off and trees were blown onto homes.  Kennywood Boulevard was impassible for a period of time following the storm as a tangle of power lines and traffic light, trees, roof debris and damaged vehicles blocked the highway.  A total of approximately 75,000 customers were without power across eastern Allegheny County, with another 14,000 customers affected across Westmoreland County.  Although power was restored to most homes by the next morning, some customer in the hardest hit areas of West Mifflin were without power for several days.  Allegheny County officials placed initial damage estimates at $10 million.

Hail in ALLEGHENY, PENNSYLVANIA
From 31-MAY-02 17:15:00 to 31-MAY-02 17:15:00 (EST)
Location: BELL ACRES
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 31-MAY-02 17:35:00 to 31-MAY-02 17:35:00 (EST)
Location: WEXFORD
Property damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm winds downed several large trees.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 31-MAY-02 17:40:00 to 31-MAY-02 17:40:00 (EST)
Location: MILLVALE
Property damage: 5K
Reported by: TRAINED SPOTTER

Thunderstorm winds downed several large trees.

Hail in ALLEGHENY, PENNSYLVANIA
From 31-MAY-02 17:45:00 to 31-MAY-02 17:45:00 (EST)
Location: PENN HILLS
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in ALLEGHENY, PENNSYLVANIA
From 31-MAY-02 17:45:00 to 31-MAY-02 17:45:00 (EST)
Location: ETNA
Magnitude: 1.00 
Reported by: TRAINED SPOTTER

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 31-MAY-02 17:50:00 to 31-MAY-02 18:05:00 (EST)
Location: HOMESTEAD
Magnitude: 91 E
Property damage: 10M
Reported by: NWS STORM SURVEY

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 31-MAY-02 18:05:00 to 31-MAY-02 18:10:00 (EST)
Location: CIRCLEVILLE
Property damage: 25K
Reported by: NWS STORM SURVEY