IEM Daily Feature
Tuesday, 06 August 2019

Severe TStorm Watch Duration

Posted: 06 Aug 2019 05:34 AM

The National Weather Service issued a Severe Thunderstorm Watch Monday afternoon for a good chunk of northern Iowa. Story County (Ames) was included in the watch that went from about 3:15 PM till 11 PM. A seven hour and forty five minute watch is a rather long duration as shown by the featured chart. The chart depicts a cumulative distribution function for the time duration of the watch at issuance and then accounting for any early cancellation. So only about 1 in 10 watches issued for Story County have a longer initial duration than yesterdays.

Good = 9
Bad = 2