NWS upgrades Greenfield to EF4 rating, 11 total tornadoes confirmed from Tuesday

The National Weather Service offices in Des Moines and Omaha confirmed at least 11 tornadoes following the rounds of severe weather on Tuesday.

The first two tornadoes in southwest Iowa hit the towns of Coburg and Hepburn during a round of severe weather early Tuesday morning. The remaining nine tornadoes — including three long-track tornadoes — struck in a wave of severe weather that moved across Iowa on Tuesday afternoon and evening.

Four more tornadoes confirmed by the National Weather Service Friday

The National Weather Service confirmed four more tornadoes touched down in Friday morning's storm.

Two EF0 tornadoes touched down in Warren County. One near Spring Hill traveled just over 2 miles with wind speeds that reached up to 75 mph. The other touched down in Martensdale and traveled for around 1 mile, also reaching up to 75 mph. Both were around 3:30 p.m.

An EF1 tornado touched down in Southern Audobon County near Exira. It touched down just after 3 p.m., and traveled more than 7 miles with winds speeds estimated up to 95 mph.

An EF2 tornado touched down just north of Greenfield, minutes after the town of 2,000 was hit. It traveled around 11.5 miles and had winds up to 115 mph. It was from the same storm cell as the EF4 that hit Greenfield.

No injuries were reported from these tornadoes.

Adair County: Greenfield, Iowa tornado was at least an EF4 that killed 5

The tornado that swept across Greenfield, Iowa on Tuesday afternoon was at least an EF4 tornado, the National Weather Service said Thursday afternoon. That's an upgrade from its initial assessment of an EF3 tornado. It's also the first time the NWS had shared the track of the storm, which ran more than 44 miles.

The tornado started south of Villisca and Nodaway before traveling past Corning, Prescott and Williamson on its way up to Greenfield. It continued past the city where it caused significant damage.

The EF4 tornado produced wind speeds of 175-185 mph and was 1,000 yards wide at its maximum size. It was on the ground for an estimated 46 minutes.

Four people died in Greenfield from the storm. A fifth person, Monica Zamarron, was killed when she was thrown from her car by the tornado on Highway 148 north of Corning.

The NWS said further refinement of the track and rating is possible in the days ahead.

Montgomery County: Early morning EF0 tornado hit Coburg, Iowa

A tornado near Coburg was the first tornado to hit Iowa on Tuesday. The EF0 tornado touched down at 7:10 a.m. and ran 0.69 miles before lifting up at 7:11 a.m. It had peak wind speeds of 75 mph.

Page County: Early morning EF1 tornado hit Hepburn, Iowa

A Tuesday morning tornado in Hepburn, Iowa left a path 3.27 miles long and had peek wind speeds of 100 mph. The tornado, which touched down around 7:32 a.m., was rated an EF1.

Montgomery County: EF1 tornado hit Red Oak, Iowa

A tornado in Red Oak, Iowa on Tuesday was rated an EF1. It traveled 2.95 miles and hit peak wind speeds of 107 mph.

Red Oak Mayor Shawnna Silvius, in a Facebook posting, said there were no reported injuries reported after a search and rescue effort on Tuesday.

The city street department's building "is likely a loss" and there were multiple downed powerlines. She said city street and wastewater employees who were present when the tornado touched down "are shook up but all are safe."

The town is scheduled to be the Day 1 overnight town on RAGBRAI in July.

Page, Montgomery and Adams counties: Preliminary work rates tornado EF3

A tornado tracked through Page, Montgomery and Adams counties for 32 miles and produced winds of up to 150 mph, according to the National Weather Service. Preliminary assessments rate the storm an EF3, but more will be posted as NWS continues its work.

Adams County: EF0 tornado confirmed south of Prescott

The NWS confirmed an additional tornado in southeast Adams County. The EF0 tornado ran for 12 miles starting around 3:19 p.m.

Polk and Story counties: EF2 tornado tracked 41 miles from Johnston through Nevada to Zearing

A National Weather Service survey team working on the north side of the Des Moines metro and into Story County, confirmed one tornado as of Wednesday afternoon.

The team confirmed an EF2-rated tornado touched down and traveled from Johnston to Zearing between 4:30 and 5 p.m. Tuesday.

Wind speed is estimated to have reached up to 135 miles per hour. The tornado traveled approximately 41 miles. There are two recorded injuries, according to the post.

The tornado touched down near Johnston High School, causing "extensive" damage that canceled classes for Wednesday.

Iowa Department of Transportation cameras also captured the tornado crossing U.S. Highway 30 near Nevada. The camera showed a stop semitrailer being pushed over as the tornado and debris moved across the road shortly before 5 p.m. on Tuesday.

The semi driver did not report any injuries, Iowa State Patrol Sgt. Alex Dinkla told the Register on Wednesday.

How were other Iowa tornadoes from Tuesday rated?

Tornadoes can't be officially confirmed until the National Weather Service can send crews out to conduct surveys. On social media, the Des Moines office said three survey teams will be in the field on Wednesday. The National Weather Service in Omaha is also sending teams into southwest Iowa to complete surveys.

Unofficial reports from trained weather spotters throughout Tuesday included: A cluster of sightings in southwest Iowa in Cromwell, Prescott, Corning, Carbon, Red Oak and Villisca. Greenfield in southwest Iowa appeared to be a particularly hard hit. In central Iowa there were unconfirmed reports in Nevada, rural Story County and southeast of Polk City.

What is an EF4 tornado?

EF4 tornados have wind gusts of at least 166 mph, according to NWS' website. The EF scale is a set of wind estimates, not measurements, based on damage.

EF ratings begin a 0, with wind gusts of 65 to 85 mph. The highest rating a tornado can have is EF5, with wind gusts of 200 mph or more.

Has Iowa ever had an EF5 tornado?

The 16-year anniversary of the last EF5 tornado in Iowa is coming up this weekend, on May 25.

In 2008, the community of Parkersburg was hit by an EF5 tornado that was the second-deadliest tornado recorded in Iowa history. Nine people died and wind gusts were up to 205 mph, causing more $100 million dollars in damage.

Victoria Reyna-Rodriguez is a general assignment reporter for the Register. Reach her at vreynarodriguez@registermedia.com or follow her on Twitter @VictoriaReynaR.

This article originally appeared on Des Moines Register: Greenfield tornado upgraded to EF4; 11 total Iowa tornadoes confirmed