EF1 tornado in Beaver County, Pennsylvania

The National Weather Service in Pittsburgh conducted a storm

survey in far northern Beaver County just northeast of New Galilee.

The damage was confined along either side of Fairlane Boulevard /

State Route 351. Majority of the damage was hardwood and softwood

trees missing large branches. One softwood tree was uprooted, which

was the damage indicator that warranted the EF1 rating. One of the

large branches fell onto a detached garage causing damage to the

roof. The tornado lifted prior to reaching the intersection of State

Route 351 and Big Beaver Boulevard.

A broken line of supercells, which formed along a front, moved quickly through the Ohio River Valley the evening of October 21st and spun off several tornadoes. The number of tornadoes, time of year, and intensity (one long track EF2 tornado) will mark this event as very rare and significant for this region.

Prior to tornado development, surface temperatures warmed into the low-mid 60s; dew points topped out near 60F. Forecast soundings indicated modest levels of mean layer CAPE, and a relatively straight hodograph yielding marginal but sufficient storm relative helicity. The overall quick track of the broken line and eastward propagation helped cells sustain rotating updrafts.