A moderate (4/5) risk of severe weather is possible for all of Grundy County and the NW corner of Tama County including the town of Lincoln; the rest of Tama County sits at an enhanced (3/5) risk for severe weather between 4 p.m. and 8 p.m. - National Weather Service - Dec. 15, 2021 - 4:22 a.m.

The Des Moines National Weather Service has produced a weather briefing concerning hazardous weather Wednesday afternoon and evening for much of Iowa including Grundy and Tama counties.

A fast moving line of severe thunderstorms is expected with damaging winds likely – rapidly moving from west to east across central Iowa between 4pm and 8pm.

Tornadoes are also possible.

Storms may enhance winds to gusts in excess of 80+ mph.

Be aware and ready to act with multiple ways to receive warning information.

Severe Weather Outlook Map - National Weather Service - Dec. 15, 2021 - 4:22 a.m.

Reaction time may be minimal due to extremely fast storm motion.

Storms could move through a typical Iowa county in only 20 minutes.

Rare wind event for Iowa

Much of Iowa’s severe weather outlook has been updated to a moderate (4/5) risk for severe weather including all of Grundy County and the northwest corner of Tama County; much of the rest of Tama county remains at an enhanced risk (3/5) for severe weather.

High wind warning has been issued for Grundy and Tama counties beginning at 3:00 p.m. today and lasting through 3:00 a.m. Thursday.

Sustained wind speeds of 30 to 40 mph and gusts in excess of 60 to 70 mph.

Winds of this magnitude are infrequent and a rare wind event for Iowa.

Strongest winds will occur late afternoon to evening.

* Any fires that start will spread quickly.

* Damage to trees and downed power lines with some power outages expected.

* Widespread non-thunderstorm high winds anticipated with gusts of 55 to 75 mph.

Historical perspective

Similar weather events from Iowa’s past include February 19, 2016, which featured peak wind gusts from 55 to 65 mp. Several semis tipped over along I-35.

November 10, 1998, featured a longer duration event of peak winds from 55 to 70 mph. The strongest winds lasted two to four hours. Trees and power lines were downed, minor structural damage occurred, and semis were blown off the road.

For up to the minute emergency alerts in Tama County, sign up for the Alert Iowa emergency notification system at https://www.smart911.com/smart911/ref/reg.action?pa=TamaCountyIowa