Locally Heavy Rainfall for the Carolinas; Thunderstorms and Fire Weather Concerns for Intermountain West

Heavy rainfall from scattered thunderstorms is expected across the Southwest, Intermountain West, and Plains. Isolated dry thunderstorms may initiate additional fires across the west. The coastal Carolinas may experience flash floods in the coming days due to repeated thunderstorms. Additionally, a wave of intense summer heat will hit the Southern Plains and central Gulf Coast States this week. Read More >

Overview

A line of storms quickly moved across southeast South Dakota, southwest Minnesota and northwest Iowa in the early morning hours of August 5, 2018. One weak tornado and hail to the size of tennis balls was reported with the initial storms near White Lake and Plankinton, SD. This was followed by several reports of tree damage and associated property and power line damage caused by fallen trees, as the line of storms moved through Sioux Falls, South Dakota, and on toward Hawarden, Sioux Center, and Sheldon, Iowa. Wind gusts in excess of 65 mph were measured in several locations.

Radar loop of early morning storms on August 5, 2018

Radar Loop of Storms in the early morning hours of August 5, 2018

Tornado
Wind & Hail
Radar
Storm Reports
Rainfall

Tornadoes:

Tornado - 2 miles south-southeast of White Lake, SD
AURORA COUNTY, SD

Date	August 5, 2018
Time (Local)	12:40 AM CDT
EF Rating	EF0
Est. Peak Winds	80 mph
Path Length	2 miles
Max Width	100 yards
Injuries/Deaths	None
Summary: A weak tornado caused damage to fences and trees, and moved large round hay bales.

Radar Image

The Enhanced Fujita (EF) Scale classifies tornadoes into the following categories:

EF0 Weak 65-85 mph	EF1 Moderate 86-110 mph	EF2 Significant 111-135 mph	EF3 Severe 136-165 mph	EF4 Extreme 166-200 mph	EF5 Catastrophic 200+ mph

Wind & Hail:

Wind

Wind gusts of 50 to 70+ mph caused primarily tree damage in several communities. The fallen trees did result in associated property and power line damage in some locations.


Fallen tree at entrance to Cherry Rock Park in Sioux Falls	Fallen trees damage power lines in Sioux Falls	Tree damage to minivan in Sheldon, Iowa	Tree damage in Sheldon, Iowa (courtesy of Sami Anderson)

Hail

Hail up to tennis ball size was reported near Plankinton, South Dakota, with several reports of smaller hail as the storm continued to move east.


Hail in White Lake (courtesy of Dixie Falk)	Hail in White Lake (courtesy of Dixie Falk)	Hail south of Plankinton (courtesy of Angie Hill Heezen)	Hail south of Plankinton (courtesy of Angie Hill Heezen)

Radar:

Header


Radar Reflectivity and Storm Relative Velocity near the time of the tornado southeast of White Lake, SD	Radar Image near the time of tree damage at Cherry Rock Park in Sioux Falls, SD