Hail in Pennsylvania, June 26, 1998

Severe thunderstorms bringing damaging winds and torrential rains affected much of east-central Ohio, western Pennsylvania and northern West Virginia during the period of June 26-30. These storms caused eight deaths and several injuries, along with millions of dollars of damage across the region. High pressure anchored over the Tennessee Valley contributed to the northward transport of a tropical airmass into eastern Ohio by the afternoon of June 26th. Explosive thunderstorm development on the afternoon of June 26th over northeast Ohio and western Pennsylvania formed a Mesoscale Convective System (MCS) by late afternoon. As this MCS propagated slowly to the southeast during the evening, it left behind a northwest-to-southeast oriented outflow boundary. This boundary remained nearly stationary for over 36 hours and served to focus waves of thunderstorms from the evening of June 26th through the early morning hours of June 28th across eastern Ohio and into western Pennsylvania. Across western Pennsylvania, although severe thunderstorms passed across the area every day during this period except the 29th, the thunderstorms on the afternoon of the 30th proved to be the most damaging. One microburst over the Pittsburgh area brought 85 MPH winds to the city, causing an estimated $41 million in damage to the area. Numerous trees were snapped or felled by the winds across the remainder of southwest Pennsylvania. One township in Allegheny County just north of Pittsburgh estimated it would take up to 30 days to clear all of the downed trees. Power was lost to over 100,000 people in the Pittsburgh area alone. Thousands of people across the region remained without power for days after the storms.