THE RARITY OF THE TORNADO EMERGENCY...
Central Iowa towns are still picking up the pieces after several tornadoes touched down and caused damage. The National Weather Service in Des Moines was out surveying the damage in Bondurant, Pella, and Marshalltown.
Home damaged in Marshalltown, via Aaron Gerhardt
As of Friday the NWS says there were at least five tornadoes and they have given preliminary ratings for some of those tornadoes.
Bondurant tornado: EF-2 with peak winds of 115 mph
Pella tornado: EF-3 with peak winds of 144 mph
Marshalltown tornado: EF-3 with peak winds of 144 mph
There is still a lot of work to do and more damage to go through, especially in Marshalltown where there was extensive damage. Even with the strength of these tornadoes and the damage done there were no fatalities with the Thursday twisters. That wasn't all luck. Tornado Warnings were issued for each storm and in Marshalltown a Tornado Emergency -- the rarest and highest level of warning -- was issued. This is the warning text for Marshalltown --
Per the NWS: A TORNADO EMERGENCY means that significant, widespread damage with a high likelihood of numerous fatalities is expected to continue with a strong and violent tornado. A tornado emergency is not a new warning product, but a new, visible and high impact call-to-action.
Because the NWS had issued a Warning for Marshalltown 53 minutes prior to the tornado touching down and then issued this Tornado Emergency - lives were saved.
Tornado Emergencies are rare - especially in Iowa. They have only been in use by the National Weather Service for a few years. The only other instance I could find a Tornado Emergency issued in Iowa was in 2013 with the EF-4 tornado in Cherokee, Iowa on October 4th. I could only find one ever issued in Illinois which was with the EF-2 in Peoria on June 5, 2010.
Additionally, the tornadoes in Pella and Marshalltown were rated EF-3. The last time there was an EF-3 tornado in Iowa was three years ago near Columbia on June 22, 2015.
Now the weather has calmed down. It is going to be a nice weekend around the Midwest with partly cloudy skies and below normal temperatures. In fact, temperatures will likely remain near and below normal through the end of the month.
This will keep the threat for severe weather, and rain in general, very low through the next several days.