NWS assessment discovers straight-line wind damage, no tornado in Johnson County

Straight-line winds caused minor damage near Iowa City as part of a storm system that rolled through the area on Tuesday night.

A preliminary National Weather Service assessment of two possible tornadic paths revealed that the damage was likely the result of high-speed straight-line winds, not a tornado as originally believed Tuesday night, the Johnson County Emergency Management Agency said on Facebook.

Wind speeds reached 81 miles per hour near both Frytown to the southwest and Riverside to the south, NWS said on Wednesday morning.

More than an inch of rain fell in parts of Johnson County during Tuesday evening's storms, according to NWS precipitation reports. At the Iowa City Municipal Airport, 1.35 inches of rain was measured. Totals fell between 1.2 and 1.35 inches of rain at various locations across Iowa City.

Nearly three inches of rain fell in Washington, Iowa, about 30 miles south of Iowa City.

The National Weather Service extended its severe weather outlook on Tuesday afternoon to include large portions of western and southern Johnson County. Iowa City, Coralville, North Liberty, and Tiffin were in the level three "enhanced risk" zone, the third-highest ranking on the NWS scale.

Sirens sounded throughout Johnson County as the National Weather Service issued a flurry of tornado warnings across eastern Iowa. Post-storm evaluations remain ongoing on Wednesday.

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10 a.m.: Flood Warning in effect along English River near Kalona

Some county roads along the English River could be underwater throughout the next few days, the National Weather Service warned.

A flood warning is in effect through Friday morning near Kalona in northern Washington County. The flooding impact will be minor, the warning noted.

The English River connects with the Iowa River near the River Junction area.

Flood warnings are issued when flooding is "happening or about to happen," according to NWS.

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6:15 p.m.: NWS confirms tornado near Hills or south Iowa City

Editor's Note: This determination has been revised as of 9:30 a.m. on Wednesday.

NWS updated its warning to say a tornado was spotted on the ground "over Hills or near Iowa City" around 6:02 p.m.

At 6:10 p.m., a confirmed tornado was also spotted over the Muscatine County Fairgrounds, eight miles southeast of West Branch, according to the NWS. Officials did not specify whether it was the same tornado.

The tornado warning that included the Iowa City area was allowed to expire at 6:30 p.m.

Portions of Cedar County and areas east were placed under a broad tornado warning through 7:15 p.m., including West Liberty, Tipton and other counties further east.

Another severe thunderstorm warning was also issued for southern Johnson County, extending west to the Mississippi River through 7 p.m.

6:05 p.m.: Flash flood warning issued for Iowa City, Coralville, areas south and west

A flash flood warning has been issued until midnight for portions of multiple counties, including Johnson County and counties to the west and south.

The warning also stretches through Frytown and Kalona.

Flash flood warnings mean that flooding is happening or about to happen.

5:50 p.m.: Tornado warning issued for southern Johnson County

The National Weather Service issued a tornado warning for large portions of Johnson County, including Iowa City, Hills, Riverside, and Kalona, through 6:30 p.m.

According to the National Weather Service, the tornado is radar-indicated but not visually confirmed. The warning said pea-sized hail is possible. This portion of the storm is moving east toward West Branch and West Liberty.

5:45 p.m.: Warnings prompt suspension of area transit services

Iowa City and Coralville Transit suspended service shortly after the severe thunderstorm warning was issued on Tuesday night. The services will communicate via text when buses resume operating.

The University of Iowa also issued a HawkAlert in the wake of the severe thunderstorm warning.

5:30 p.m.: Incoming storms prompt sirens in Johnson County

The National Weather Service issued a severe thunderstorm warning for portions of southern Iowa and Johnson County and areas of northern Washington County.

This warning includes the communities of Frytown, Kalona, Wellman, Hills and Lone Tree and runs through 6:15 p.m.

The warning comes with strong winds and pea-sized hail. Earlier this afternoon, NWS issued a tornado warning for the communities of North and South English and Wellman. That warning expired at 5:30 p.m.

3:15 p.m.: Tornado watch sprawls southern half of state

The National Weather Service has issued a tornado watch for large portions of the state, especially in the south. The watch includes Johnson and Linn counties in eastern Iowa and stretches as far west as Des Moines and Ames.

The watch warns of "a couple" tornadoes, hail up to two inches in diameter, and winds that could reach 70 miles per hour.

The watch extends through 9 p.m.

2 p.m.: Flooding possible during heavy downpour

A flood watch has also been issued for much of eastern Iowa and portions of Wisconsin and Illinois. The National Weather Service expects the storm to produce one to three inches of rainfall through the evening.

The watch begins at 3 p.m. on Tuesday and extends through 1 a.m. on Wednesday morning.

Like other watches and warnings, flood watches indicate that flooding is "possible or likely" within a given area. Flood warnings indicate flooding is "happening or about to happen."

Flash flooding is also possible tonight, the NWS said.

Ryan Hansen covers local government and crime for the Press-Citizen. He can be reached at rhansen@press-citizen.com or on X, formerly known as Twitter, @ryanhansen01.

This article originally appeared on Iowa City Press-Citizen: Straight-line winds, flooding hampered eastern Iowa on Tuesday