National Weather Service United States Department of Commerce

Major Winter Storm to Impact the Mid-Atlantic and Northeast; Inclement Weather in the Pacific Northwest

A major winter storm is expected to bring heavy snow, strong winds, and coastal flooding across the Mid-Atlantic and Northeast that may cause impossible travel conditions and power outages. Blizzard conditions are possible along coastal areas from the DelMarVa Peninsula through southeastern New England. Wet weather and strong winds return to the Pacific Northwest and north-central California. Read More >

Overview

On June 29, 2019 a surface boundary was located across south central South Dakota. Very strong instability along the boundary was realized when a thunderstorm exploded along it. The thunderstorm updraft stretched energy along the boundary into a very slow moving tornado near Allen, SD.

The tornado was visible for many miles. It was unusual because it only moved within a two mile area, but lasted about 40 minutes. Fortunately, it spun over corn fields most of the time. It damaged a house, blew over a couple of grain bins, snapped power poles, and carried grain bags. The tornado was rated EF-1 by an NWS storm survey team.

More information about the environment of the Allen tornado can be found here

Tornado near Allen, SD
Courtesy Chris O.
Tornado near Allen, SD Tornado near Allen, SD Tornado near Allen, SD
Courtesy Gail S. Courtesy Josie D. Courtesy Ang G.
nws logo Media use of NWS Web News Stories is encouraged!
Please acknowledge the NWS as the source of any news information accessed from this site.
nws logo