Alert archive / Iowa / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 18, NWS La Crosse, WI

May 21, 2024Chickasaw County, Fayette County, Winneshiek County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at May 21, 2024, 3:17 AM CDT for Chickasaw County, Fayette County, Winneshiek County, Iowa. It was in force for 43 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 21, 2024, 3:17 AM CDT (08:17 UTC)
Expired: May 21, 2024, 4:00 AM CDT
In force: 43 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Damage threat: Considerable
Hail: 0.75 in
Wind: 70.0 mph

Counties Chickasaw County, IA, Fayette County, IA, Winneshiek County, IA

The radar

The La Crosse radar (KARX), 106 km from the middle of the area, began a volume at 08:18 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 8.3 hours before the alert went out and 203 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 812 J/kg
Mixed-layer CIN: -32 J/kg
Mixed-layer LCL: 1664 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 15 m²/s²
0-3 km storm-relative helicity: 47 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS La Crosse, WI wrote its last area forecast discussion before this severe thunderstorm warning went out at May 20, 10:30 PM CDT, 4 hours 47 minutes earlier.

Area forecast discussion, May 20, 10:30 PM CDT, 4 hours 47 minutes before

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Hazardous weather outlook, May 20, 1:32 PM CDT, 13 hours 45 minutes before

Hazardous Weather Outlook
National Weather Service La Crosse WI
132 PM CDT Mon May 20 2024

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-211200-
Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette-
Clayton-Wabasha-Dodge-Olmsted-Winona-Mower-Fillmore-Houston-
Taylor-Clark-Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-
Adams-Vernon-Crawford-Richland-Grant-
132 PM CDT Mon May 20 2024

This Hazardous Weather Outlook is for parts of southeast
Minnesota...northeast Iowa and southwest into central Wisconsin.

.DAY ONE...Tonight

Storms will redevelop, especially across parts of southeast
Minnesota and northern Iowa. Strong to severe storms could develop
overnight with large hail and damaging winds.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Multiple rounds of storms are expected Tuesday. Storms could
impact the area Tuesday morning, with more redevelopment expected
Tuesday afternoon and evening / 3-9pm / when the highest
potential for severe storms exists. Storm activity later in the
day will depend on where morning storms track. All hazards are
possible Tuesday with damaging wind gusts and tornadoes being the
primary threats, large hail is also possible with some storms.

With the consecutive rounds of thunderstorms, localized areas may
recieve several inches of rain. As a result, the threat for river
rises and flooding will be on the increase. Those with interests
along area creeks, streams, and rivers should monitor conditions
closer to start the week.

More thunderstorms are possible later in the week / Friday and
Saturday / but it is too early to discern the severe weather
threat at this time.

.SPOTTER INFORMATION STATEMENT...

Spotters should monitor the weather closely tonight through
Tuesday. Tuesday afternoon and evening look like the highest
potential for severe weather but please report any hail, gusty
winds, or other severe weather if observed. Activation could be
needed at times.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

Naylor/Shea

In the hours before

Local storm report, May 20, 9:24 PM CDT, 5 hours 53 minutes before

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Special weather statement, May 20, 10:10 PM CDT, 5 hours 7 minutes before

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The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 21, 10:30 AM CDT	River Flood Watch	ARX	Jackson	24 hr
May 21, 10:30 AM CDT	River Flood Watch	ARX	Juneau	3 days
May 21, 12:30 PM CDT	Special Weather Statement	ARX	Buffalo, Trempealeau	45 min
May 21, 3:30 PM CDT	Severe Thunderstorm Warning	ARX	Grant	45 min
May 21, 6:09 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ARX	Buffalo, Jackson, La Crosse, Monroe, Trempealeau	66 min
May 21, 6:16 PM CDT	Tornado Warning	ARX	Buffalo, Trempealeau	16 min
May 21, 6:35 PM CDT	Severe Thunderstorm Warning	ARX	Grant	25 min
May 21, 6:40 PM CDT	Tornado Warning	ARX	Jackson, Trempealeau	31 min
May 21, 6:41 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ARX	Crawford	52 min
May 21, 6:47 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ARX	La Crosse, Monroe, Vernon	43 min
May 21, 6:55 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ARX	Clark, Jackson, Monroe, Vernon	65 min
May 21, 1:31 AM CDT	Flood Watch	ARX	Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more	19 hr
May 21, 11:24 AM CDT	River Flood Watch	ARX	Clayton	18 hr
May 21, 11:24 AM CDT	River Flood Warning	ARX	Winneshiek	29 hr
May 21, 11:24 AM CDT	River Flood Warning	ARX	Clayton	53 hr
May 21, 11:42 AM CDT	Special Weather Statement	ARX	Chickasaw, Clayton, Fayette, Howard, Mitchell, Winneshiek	48 min
May 21, 5:03 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ARX	Floyd, Mitchell	57 min
May 21, 5:24 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ARX	Chickasaw, Howard	66 min
May 21, 5:51 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ARX	Winneshiek	39 min
May 21, 6:14 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ARX	Fayette	46 min
May 21, 6:24 PM CDT	Flash Flood Warning	ARX	Fayette, Winneshiek	3 hr
May 21, 6:28 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ARX	Allamakee, Winneshiek	62 min
May 21, 6:49 PM CDT	Flash Flood Warning	ARX	Allamakee, Winneshiek	3 hr
May 21, 6:49 PM CDT	Tornado Warning	ARX	Allamakee, Clayton, Fayette, Winneshiek	15 min
May 20, 7:13 PM CDT	Severe Thunderstorm Warning	ARX	Dodge, Olmsted	62 min
May 20, 7:31 PM CDT	Severe Thunderstorm Warning	ARX	Dodge, Mower	44 min
May 20, 7:53 PM CDT	Areal Flood Advisory	ARX	Dodge, Olmsted	2 hr
May 20, 9:51 PM CDT	Areal Flood Advisory	ARX	Mower	2 hr
May 20, 10:10 PM CDT	Special Weather Statement	ARX	Mower	35 min
May 20, 10:17 PM CDT	Severe Thunderstorm Warning	ARX	Mower	41 min
May 21, 5:08 PM CDT	Severe Thunderstorm Warning Considerable damage threat	ARX	Dodge	52 min
May 21, 6:05 PM CDT	Tornado Warning	ARX	Winona	25 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2024 Every severe thunderstorm warning in 2024

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.