Des Moines, IA

Weather Forecast Office

Fast Moving Storms on March 28th, Produced First Tornadoes of 2020 in Iowa

Overview

A strong spring storm system moved through portions of the Midwest on Saturday, March 28th, 2020. Thunderstorms developed over portions of southwest Iowa during the early afternoon hours along a northward advancing warm front. Scattered storms then raced quickly to the northeast across central and northeastern Iowa. One EF1 tornado occurred near the Adair and Adams County line with several other brief and weak tornadoes occurring over Marshall and Black Hawk Counties. Hail reports of pea to half dollar sized hail were also received over portions of central and northern Iowa on the cooler side of the boundary. Minor to moderate property damage was reported with the tornadoes but thankfully no injuries. In addition to the 4 tornadoes in the WFO DMX area, 2 additional tornadoes formed in NWS ARX, including an EF-1 that hit the west side of Oelwein, Iowa. Here, you can find a write-up for northeast Iowa. These were the first tornadoes of 2020 for Iowa.

Radar loop of the entire of event with warnings overlaid.


Tornado and rainbow south of Waterloo, Iowa. Photo courtesy of Mark Schnackenburg	Near Stuart, Iowa. Photo courtesy of Gregory Clark.	Damage to two machine sheds south of Bridgewater, Iowa in Adair County. Photo Courtesy of Emergency Manage Bob Kempf.

Tornado
Photos & Video
Storm Reports
Environment

Tornadoes

Tornado #1 - South of Fontanelle
Adair/Adams Counties

Date	3/28/2020
Time (Local)	1:59 PM - 2:15 PM CDT
EF Rating	EF-1
Est. Peak Winds	95 mph
Path Length	4.5 miles
Max Width	80 yards
Injuries/Deaths	0 injury / 0 deaths
Summary: Tornado developed in far northern Adams County and did minor damage to a farmstead before entering Adair County. Much of the path was then across open farmland. However, one farmstead was impacted with EF-1 damage to an outbuilding or machine shed.

Track Map

Downloadable KMZ File


Base reflectivity (left) and storm relative velocity (right) at 2:00 PM CDT 3/28/2020.	Base reflectivity (left) and storm relative velocity (right) at 2:04 PM CDT 3/28/2020	Radar loop showing the transition of the couplet in conjunction with the tornado track.	Caption

Tornado #2 - South of Rhodes
Marshall County

Date	3/28/2020
Time (Local)	4:26 PM - 4:27 PM CDT
EF Rating	EF-Unknown
Est. Peak Winds	Unknown
Path Length	0.8 miles
Max Width	40 yards
Injuries/Deaths	0 Injuries/Deaths
Summary: Tornado developed near State Highway 330 and moved north through rural farmland. No damage indicators were impacted, therefore the EF-Unknown rating.

Track Map

Downloadable KMZ File


Caption	Caption	Caption	Caption

Tornado #3 - South of Hudson
Black Hawk County

Date	3/28/2020
Time (Local)	5:39 pm - 5:40 pm CDT
EF Rating	EF-Unknown
Est. Peak Winds	Unknown
Path Length	1.0 miles
Max Width	40 yards
Injuries/Deaths	0 injuries/deaths
Summary: Brief tornado in rural area near Voorhies. Tornado did not impact damage indicators, hence the EF-unknown rating.

Track Map

Downloadable KMZ File


Caption	Caption	Caption	Caption

Tornado - South of Waterloo
Black Hawk County

Date	3/28/2020
Time (Local)	5:49 pm - 5:51 pm CDT
EF Rating	EF-0
Est. Peak Winds	85 mph
Path Length	1.9 miles
Max Width	50 yards
Injuries/Deaths	0 injuries/deaths
Summary: Tornado developed just south of Waterloo, Iowa in a farm field. The tornado moved quickly northeast, removing and overturning the roof of an open poll barn. A small nearby garage was also demolished. The tornado continued northeast through open fields before dissipating just south of Highway 20.

Track Map

Downloadable KMZ File


Base reflectivity (left) and Storm Relative Velocity (right) at 5:49 PM CDT at the beginning of the tornado.	Base reflectivity (left) and Storm Relative Velocity (right) at 5:50 PM CDT.	Base reflectivity (left) and Storm Relative Velocity (right) at 5:51 PM CDT as the tornado lifted.	Animation of base reflectivity (left) and storm relative velocity (right) from 5:49 PM to 5:56 PM CDT.

The Enhanced Fujita (EF) Scale classifies tornadoes into the following categories:

EF0 Weak 65-85 mph	EF1 Moderate 86-110 mph	EF2 Significant 111-135 mph	EF3 Severe 136-165 mph	EF4 Extreme 166-200 mph	EF5 Catastrophic 200+ mph

Photos & Video

A few photos from the event, including some damage pictures.


Very low hanging wall cloud near Prairie City, Iowa. Photo courtesy of Jason Blommers.	Damage to a barn south of Waterloo, Iowa. Photo courtesy of Ty Bellfy via KWWL.	2x4 ejected into the side of a house just south of Fontanelle, Iowa. Photo courtesy of Bob Kempf.	Southwest of Waterloo, Iowa. Photo courtesy of Tanner Schaaf.

Storm Reports

Click on the map or this link to the right for list of storm reports: https://nwschat.weather.gov/lsr/#DMX/202003281910/202003282250/0100

Environment

An area of low pressure transitioned across the Central Plains and through the Corn Belt dragging a sharp cold front behind it. Out ahead of the surface low, a warm front surged northward through the day and made it about as far north as Highway 30 to even portions of Highway 20 by the late afternoon hours. Fast moving storms produced 6 tornadoes across the state.


Surface analysis throughout the day March 28, 2020. this shows the strong low pressure system and associated warm front and cold front that tracked across the state.	850 mb loop of the event shows the strong low pressure system tracking northeast over northwest portions of Iowa.	As the low pressure moved across the region, it pulled significant amounts of moisture north into the state which is a key ingredient for tornadic development.

Near-storm environment summary.


Significant Tornado Parameter as the storms rolled northeast across Iowa. Most significant tornadoes (EF-2 or greater) have been associated with a STP values greater than 1. As you can see, 3-4 values of STP were found over Iowa. Find more info here on this parameter.	0-3 KM CAPE values tend to support tornado formation when co-located with significant vertical velocity near the ground. Via SPC	Effective Storm Relative Helicity (m2s2). For official definition, click here.

GOES-East 1-minute Satellite data and NWS SPC Outlook and Watch.


Storms initiating over southwest Iowa.	Storm Prediction Center's Day 1 Outlook Updated at 11:30 AM, March 28, 2020.	PDS Tornado Watch issued at 2:45 PM CDT on Saturday, March 28, 2020.

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