Derecho Danger!

In addition to the significant risk of tornadoes (tornado watch continues in effect), a second major weather risk is developing for Iowa: a derecho. A derecho is a long-lived, widespread damaging wind event quite capable of causing power failures.  Derechoes also cause tornadoes but usually on the leading edge of the storm rather than the trailing edge.

Here are some safety suggestions:

• Go to the ATM and get some extra cash well before the storms approach. 
• Fill your car's tank with gas or charge your electric car. 
• Derechoes can move very quickly. Make sure your children and infirm relatives are accounted for at all times and can be easily and quickly sheltered. 
• Plan to park your car in the garage.
• Bring in lawn furniture, grills, and trampolines.
• Make sure you have a source of weather information when thunderstorms approach that will work if the power fails. 
• Be sure your shelter has a flashlight, batteries, a bottle of water. Wear shoes and take your cell phones.

I am not able to live-blog these storms. Please go to AccuWeather.com for more information throughout the day.

UPDATE: 11:47am CDT…

With a derecho looking more and more likely, the Storm Prediction Center has updated its damaging wind forecast since I posted their 8am version below.

Fifteen percent is the significant threshold for thunderstorm-related wind gusts of 60 mph or higher. The hatched area is where wind gusts of 75 mph or higher are forecast to occur.