Terry’s Take: Impact based warnings

Posted on: 6:26 pm, March 20, 2013, by , updated on: 01:55pm, March 22, 2013

Terry Swails Weather Blog

2011 was a historic year in terms of the number of tornado fatalities across the United States with over 550 recorded. The May 22, 2011, Joplin tornado resulted in nearly 160 of the deaths, making it the single deadliest tornado since modern record keeping began in1950. Following the Joplin tornado, an experimental warning program was started in Kansas and Missouri that will be used across much of the central U.S. this severe weather season.
IMPACT WARNING EXAMPLE

IMPACT WARNING EXAMPLE

STRONG WORDING FOR DANGEROUS STORMS

STRONG WORDING FOR DANGEROUS STORMS

Beginning April 1st, the National Weather Service will issue impact-based warnings for severe thunderstorms throughout the Midwest.  This is an expansion of the successful NWS experiment that began last year. It was implemented after surveys following deadly tornadoes in Joplin, Missouri and Tuscaloosa, Alabama found that most people didn’t heed the initial warnings about the oncoming storms. The research also concluded that people in tornado-prone areas have become desensitized by frequent false alarms and don’t always pay attention to the initial warnings.

WARNING BOX FOR TORNADO PRODUCING STORM

WARNING BOX FOR TORNADO PRODUCING STORM

Offices in Missouri and Kansas last storm season began sending out “impact-based” warnings during severe weather that describe how much damage a storm could cause. Among the messages in the new warnings:

“COMPLETE DESTRUCTION OF ENTIRE NEIGHBORHOODS IS LIKELY” and “MASS DEVASTATION IS HIGHLY LIKELY MAKING THE AREA UNRECOGNIZABLE TO SURVIVORS.”

TWIN TORNADOES NEAR ELKHART, IN 1965

TWIN TORNADOES NEAR ELKHART, IN 1965

The goal of impact-based warnings is provide to provide additional valuable information to media and emergency management officials, which in turn is expected to improve the public’s willingness to seek the necessary shelter.