EF1 tornado in Washington County, Pennsylvania

Tornado October 21, 2021 · Washington County, Pennsylvania

EF1

Rating

0.9 mi

Whole path

50 yd

Path width

NOAA records this tornado county by county. Its path ran through Washington County → Washington County; the totals above are for the whole tornado.

EF0EF1EF2EF3EF4EF5Unrated

The path drawn at its surveyed width of 50 yards (0.03 mi) — zoom in and the swath grows to true scale. Other tornadoes recorded nearby that day are shown faint.

What EF1 means. On the Enhanced Fujita scale, EF1 is moderate damage: roofs badly stripped, mobile homes pushed off foundations or overturned, windows broken, consistent with estimated gusts of 86–110 mph. The rating comes from a survey of the worst damage after the storm, not from a wind measurement, so it says as much about what the tornado hit as about how strong it was.

What the National Weather Service wrote

The National Weather Service conducted a survey off E Finley Dr in

Washington County. The damage path was oriented west-to-east near

a road that consisted of farms and residences. Damage consisted

of several snapped and uprooted hardwood trees, roof damage to a

shed, and a completely destroyed barn. Estimated Maximum Wind Speed...100 mph.

The wider storm

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.

Began near Gale (39.9980, -80.3650).

Other tornadoes from the same storm system

7 more tornadoes the National Weather Service filed under this storm episode.

EF2 Washington County EF1 Allegheny County EF1 Washington County EF1 Beaver County EF1 Beaver County EF0 Allegheny County EF0 Butler County

Source: NOAA Storm Events Database, event 987794. Narratives are written by the National Weather Service forecast office that issued the report.

Tornadoes near your address

See every tornado that passed near a place you know, measured to its path.