F4 Tornadoes in Eastern Iowa – 8/12/1974

Two damaging tornadoes tracked through eastern Iowa on August 12, 1974 casing major damage and several injuries.

The first tornado moved through the southern end of Ryan in Delaware County.  The tornado was an F4, damaging or destroying several dozen homes.  Two business were also hit hard, along with a school and Saint Patrick’s Church in town.  According to the National Weather Service Des Moines, the church and 20 other businesses were destroyed.  There were 12 injuries in Ryan.

 

Another tornado touched down in Iowa County, near Ladora.  Two people were injured, and the tornado swept away a farm house.  The Ladora tornado was also an F4.

The Fujita Scale (F-Scale) was retired in 2007, and replaced by the Enhanced Fujita Scale.  The F-Scale was based on the damage from the tornado.  Enhance Fujita Scale also takes into account the damage, but the ratings are put in line with coinciding wind speeds with the damage.  All based on estimates.

Below is the surface and upper air map from that day at 6 AM Iowa time.  You can see a cold front approaching from the northwest, and a dip in the 500 mb jet stream.

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Posted under Severe Weather, Weather History

This post was written by Kyle Kiel on August 12, 2018

July 19 Tornado Outbreak

The National Weather Service has now confirmed 15 tornadoes have occurred on July 19, 2018 in Iowa. Here is a break down on the ratings.

EF0...WEAK......65 TO 85 MPH
EF1...WEAK......86 TO 110 MPH
EF2...STRONG....111 TO 135 MPH
EF3...STRONG....136 TO 165 MPH
EF4...VIOLENT...166 TO 200 MPH
EF5...VIOLENT...>200 MPH

Below is the official path the Marshalltown tornado took according the the National Weather Service:

 

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Posted under Severe Weather

This post was written by Schnack on August 2, 2018

Dust Devil in California

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Posted under Severe Weather, Video

This post was written by Schnack on July 24, 2018

Tornado Rating information

Here is the information about the five tornadoes from Thursday afternoon. The information is preliminary and more information will be released through the next several days. Here is what we know as of Friday evening. Additional tornadoes might be confirmed as the National Weather Service continues to do damage surveys.

 

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Posted under Severe Weather

This post was written by Schnack on July 20, 2018

One Year since EF-1 Tornado in McGregor

It’s been a year since an EF-1 tornado tracked through portions of Clayton County, and causes severe damage in the historic downtown area of McGregor.  Two buildings were destroyed.

The tornado began 0.4 miles northeast of Giard, and tracked through the town of McGregor, before lifting east of town in the Mississippi River.  It was on the ground for 5.7 miles and was 400 yards wide.

Estimated wind speeds for the tornado were 110 mph, which equates to EF-1 damage.  Two people were injured due to flying glass.

West of McGregor, several trees were damaged, a metal roof on an outbuilding was ripped back and a storage shed was damaged.

Several inches of rain also lead to flooding in northeast Iowa that evening.  For more information on that, including radar history and photos from the damage, here is the storm assessment from our friends at the National Weather Service in La Crosse, WI.

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Posted under Severe Weather, Weather History

This post was written by Kyle Kiel on July 19, 2018

Iowa-Wisconsin Flooding of July 2007

Iowa is no stranger to flooding events. On July 17, 2007, storms tracked through northeast Iowa and southwestern Wisconsin.

Severe weather alerts were in place that evening into the early morning hours of July 18th. Large hail and severe winds were reported within those counties in the large yellow polygon.

Storm reports July 17-July 18, 2007. Green values represent hail reports while blue values represent wind reports.

Winds damaged trees in Dubuque and Clayton counties. In addition to the hail and wind experienced overnight, very heavy rain fell along the Iowa-Wisconsin border into the morning of the 18th.

National precipitation ending 6AM Central, July 18, 2007

 

Heavy rain near the Mississippi during the early morning of July 18, 2007

 

The rain caused flooding on the morning of the 18th in counties and towns close to the Mississippi where Iowa and Wisconsin meet. Marquette and McGregor in Clayton Co, Iowa and Bagley in Grant Co, Wisconsin were some of the hardest hit areas, according to the National Weather Service (NWS) in La Crosse, Wisconsin.

More than 8 inches was reported in McGregor and Marquette. Prairie Du Chien had multiple reports of over 5 inches in Crawford Co, Wisconsin, with one report of more than 7 inches. 911 calls began coming in early in the morning in Grant Co, WI. Flooding and mudslides were seen in Iowa. The area near Bagley, Wisconsin experienced similar effects as well as sewage backup and power issues.

Flooding in Bagley, WI July 18, 2007

Mudslides July 18, 2007

When looking at the rain totals across the state of Iowa in that month, the heaviest amounts of rain were concentrated in counties closer to the Mississippi River.

Iowa rainfall July 2007

The highest rain totals in Iowa during August 2007 would be recorded in the northeastern part of the state.

Iowa rainfall August 2007

In fact, another flooding event occurred in northeast Iowa, southeast Minnesota and southwestern Wisconsin in August 2007.

For more information on the July 17-18, 2007 flooding event, visit the NWS La Crosse event recap.

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Posted under Flooding, Severe Weather, Weather History

This post was written by Rachael Peart on July 18, 2018

EF-0 Tornado Keokuk County



...NWS DAMAGE SURVEY FOR 06/20/2018 TORNADO EVENT...

.KEOKUK COUNTY TORNADO...

RATING:                 EF-0
ESTIMATED PEAK WIND:    65 MPH
PATH LENGTH /STATUTE/:  6.3 MILES
PATH WIDTH /MAXIMUM/:   50 YARDS
FATALITIES:             0
INJURIES:               0

START DATE:             JUN 20 2018
START TIME:             2:31 PM CDT
START LOCATION:         1 MI ESE DELTA, IA

END DATE:               JUN 20 2018
END TIME:               2:39 PM CDT
END LOCATION:           2 MI NNW SIGOURNEY, IA

SURVEY SUMMARY: 

A SURVEY DONE BY THE KEOKUK COUNTY EM FOUND THAT AN EF0
TORNADO TOUCHED DOWN JUST EAST OF DELTA IA.  THE ONLY DAMAGE 
ALONG ITS 6.3 MILE PATH WAS TO CORN.  A SPECIAL THANK
YOU TO THE KEOKUK COUNTY EM FOR PROVIDING US WITH THIS
INFO!
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Posted under Severe Weather

This post was written by Schnack on July 3, 2018

Funnel Clouds

The conditions this afternoon could result in funnel clouds. These are not the type associated with thunderstorms. They are small and typically drop a few hundred feet from the clouds. Rarely do they ever reach the ground and if they do it is for just a brief time. Here are a few photos sent in of the funnel clouds this afternoon.

 

west of Garwin

south of La Porte City

south of Dysart

Belle Plaine

La Porte City

south of Wellsburg

Jesup

southeast of Dysart

west of Brooklyn

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Posted under Severe Weather

This post was written by Schnack on June 19, 2018

EF-1 Tornado in Winthrop Saturday Evening

NWS DAMAGE SURVEY FOR 06/09/18 TORNADO EVENT...

Brief tornado occurred Saturday evening in Buchanan
County Iowa.

Winthrop TORNADO...

RATING:                 EF-1
ESTIMATED PEAK WIND:    95 MPH
PATH LENGTH /STATUTE/:  0.1 MILES
PATH WIDTH /MAXIMUM/:   20 YARDS
FATALITIES:             0
INJURIES:               0

START DATE:             June 09 2018  
START TIME:             9:36 PM CDT 
START LOCATION:         6.0 SE Winthrop / Buchanan / Iowa 
START LAT/LON:          42.4419 / -91.6231

END DATE:               June 09 2018 
END TIME:               9:37 PM CDT 
END LOCATION:           6.0 SE Winthrop / Buchanan / Iowa 
END LAT/LON:            42.4430 / -91.6219  

An EF-1 tornado touched down southeast of Winthrop, IA. A house
was damaged. Garage door failed and roof came off in the wind. 
Some tree damage was also noted in the area. 

EF SCALE: THE ENHANCED FUJITA SCALE CLASSIFIES TORNADOES INTO THE
FOLLOWING CATEGORIES BASED ON THE DAMAGE THEY CAUSE.

EF0...WEAK......65 TO 85 MPH
EF1...WEAK......86 TO 110 MPH
EF2...STRONG....111 TO 135 MPH
EF3...STRONG....136 TO 165 MPH
EF4...VIOLENT...166 TO 200 MPH
EF5...VIOLENT...>200 MPH
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Posted under NOAA, Severe Weather

This post was written by Schnack on June 11, 2018

A severe thunderstorm moved across Tama County with heavy rain, lightning, gusty winds and large hail. All the reports and photos we have gotten this evening were from Traer.

Here is the warning issued at 4:34 PM…

Here is a look at the radar…

Golf ball size or maybe a little large were some of the reports. There might be some damage to vehicles and the roof of you home or business. You might want to have them checked out to make sure there was no damage.

 

Trista Zimp

Anthony Kinkade

Edward Hatcher

Jennifer Ambrose

Michelle Siversten

Bill Dedic (a view from Waterloo)

Melissa Potter

Scott & Karla Weber

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Posted under Photo, Severe Weather

This post was written by Schnack on June 6, 2018