CEDAR RAPIDS, Iowa (KCRG) - UPDATE 10:06 p.m.: The Tornado and Severe Thunderstorm Watches have been canceled for eastern Iowa. However, widespread showers and storms are still likely overnight which could bring heavy rainfall and flash flooding.
Tornado Watch #670, in yellow, in effect until 10:00 p.m., and Severe Thunderstorm Watch #671, in pink, in effect until Midnight (KCRG)
Thunderstorms will bring a variety of potential hazards to eastern Iowa this evening, according to forecasters.
The Storm Prediction Center has issued Tornado Watch #670, in effect until 10:00 p.m. tonight, for parts of Iowa, Kansas, and Nebraska. In the KCRG-TV9 viewing area, it includes Bremer, Black Hawk, Grundy, Mahaska, Marshall, Poweshiek, and Tama counties.
Storms developing in western and central Iowa will move to the northeast into eastern Iowa. They will carry the threat of damaging winds and isolated tornadoes.
"Enough instability built up along and ahead of a cold front that's draped across Iowa to bring a threat of some severe storms this evening," Joe Winters, TV9 chief meteorologist, said. "Combine that with a lot of spin in the atmosphere, and we could wind up with a few storms that could produce a tornado."
Wind shear, which is a measure of change of wind speeds and direction with height, is strong across the Tornado Watch area, which is leading to the severe weather threat.
An additional threat with storms tonight would be very heavy rainfall. A Flash Flood Watch is in place for much of the TV9 viewing area, with a wide area of one to three inches of rain possible. This could lead to flash flooding, especially in areas that have seen recent heavy rainfall.
More rain is expected Wednesday before conditions dry out with cooler temperatures.