TornadoLookup

Home / Alabama / St. Clair

EF1 tornado in St. Clair County, Alabama

Tornado March 19, 2018 · St. Clair County, Alabama

EF1
Rating
6.4 mi
Whole path
880 yd
Path width

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

EF0EF1EF2EF3EF4EF5Unrated

The path drawn at its surveyed width of 880 yards (0.50 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

National Weather Service meteorologists surveyed damage in northern St. Clair County and determined that the damage was consistent with an EF1 tornado, with maximum sustained winds near 90 mph. This tornado began just west of the St. Clair/Blount County line near Jones Chapel Loop Road. The tornado crossed Blount Mountain along Walker Gap Road and crossed Crawford Cove Road near Highway 11. Trees in this area were mainly uprooted with only a few snapped off. The tornado continued eastbound and eventually lifted near the Interstate 59 rest area just south of the Ashville exit. The majority of the damage was due to trees falling on structures and power lines.

The wider storm

Six tornadoes and hail up to 3 inches in diameter affected the northern areas of Central Alabama on the afternoon and evening hours of March 19th, with a rare PDS (Particularly Dangerous Situation) Tornado Watch issued for a large portion of Central Alabama. An environment favorable for significant severe thunderstorms developed as a low-amplitude upper-level trough moved into the region with a deepening surface low passing across far north Alabama. These two features resulted in a deep column of strong wind shear with 0-6km Bulk Shear values of 60-70 knots. Additionally, moist southerly flow, warm surface temperatures, and colder temperatures aloft yielded a moderately unstable air mass. Initially, thunderstorms were producing large to very large hail. However, the tornado threat increased in the late afternoon and evening hours as wind speeds at low levels increased with the arrival of a low-level jet.

Began near Caldwell (33.8549, -86.3881).

Other tornadoes from the same storm system

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

Source: NOAA Storm Events Database, event 746481. 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.