Alert archive / Iowa / Tornado Warnings in 2024

Tornado Warning 43, NWS Des Moines, IA

May 21, 20245 counties in Iowa

NWS Des Moines, IA issued this tornado warning at May 21, 2024, 3:55 PM CDT for 5 counties in Iowa. It was in force for 50 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: May 21, 2024, 3:55 PM CDT (20:55 UTC)
Expired: May 21, 2024, 4:45 PM CDT
In force: 50 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.25 in

Counties Clarke County, IA, Madison County, IA, Ringgold County, IA, Union County, IA, Warren County, IA

The radar

The Des Moines radar (KDMX), 76 km from the middle of the area, began a volume at 20:58 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.

What was reported inside it

Time	Report	Where	Remark
May 21, 4:18 PM CDT	TSTM WND DMG	2 W Murray, IA	Report from mPING. 3-inch tree limbs broken. Power poles broken.
May 21, 4:18 PM CDT	HAIL 0.75	1 S Murray, IA	Report from mPING: penny size hail.
May 21, 4:29 PM CDT	TSTM WND DMG	1 E Saint Marys, IA	Report from mPING. 3-inch tree limbs broken. Power poles broken.
May 21, 4:31 PM CDT	HAIL 1	2 W Murray, IA	Report from mPING: Quarter size hail.
May 21, 4:43 PM CDT	HAIL 0.75	3 S Saint Marys, IA	Report from mPING Penny Size Hail.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this tornado warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 21, 1:14 PM CDT	Tornado Watch PDS	SPC	8 hr

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 8.9 hours before the alert went out and 270 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: 1197 J/kg
Mixed-layer CIN: -325 J/kg
Mixed-layer LCL: 744 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 562 m²/s²
0-3 km storm-relative helicity: 663 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.4

Open this sounding in Storm Lab

The text

As transmitted.

976 
WFUS53 KDMX 212055
TORDMX
IAC039-121-159-175-181-212145-
/O.NEW.KDMX.TO.W.0043.240521T2055Z-240521T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
355 PM CDT Tue May 21 2024

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Southeastern Madison County in south central Iowa...
  Eastern Union County in south central Iowa...
  North central Ringgold County in south central Iowa...
  Northwestern Clarke County in south central Iowa...
  Southwestern Warren County in south central Iowa...

* Until 445 PM CDT.

* At 354 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Arispe, or 11 miles southeast of Creston, moving
  northeast at 75 mph.

  HAZARD...Tornado and half dollar size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Afton and Thayer around 400 PM CDT.
  Murray and Lorimor around 405 PM CDT.
  Truro and East Peru around 410 PM CDT.
  St. Charles around 415 PM CDT.
  Avenue Of The Saints Event Center and St. Marys around 420 PM CDT.
  Indianola and Lake Ahquabi State Park around 425 PM CDT.

Other locations impacted by this tornadic thunderstorm include New
Virginia, Truro, Bevington, Lake Ahquabi State Park, Thayer,
Martensdale, Shannon City, Afton, Patterson, and Murray.

This includes Interstate 35 between mile markers 40 and 65.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4084 9422 4094 9434 4148 9378 4130 9349
TIME...MOT...LOC 2054Z 226DEG 64KT 4095 9419 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.25 IN

$$

Curtis

What forecasters said that day

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

NWS Des Moines, IA wrote its last area forecast discussion before this tornado warning went out at May 21, 1:42 PM CDT, 2 hours 13 minutes earlier. Its key messages:

Take action for ALL weather warnings this afternoon with tornadoes, damaging wind gusts, and large hail all possible
Renewed or prolonged flooding possible with rain that falls this afternoon with rivers rising

Area forecast discussion, May 21, 1:42 PM CDT, 2 hours 13 minutes before

Area Forecast Discussion
National Weather Service Des Moines IA
142 PM CDT Tue May 21 2024

.KEY MESSAGES...
- Take action for ALL weather warnings this afternoon with
  tornadoes, damaging wind gusts, and large hail all possible
- Renewed or prolonged flooding possible with rain that falls
  this afternoon with rivers rising

&&

.DISCUSSION...
Issued at 142 PM CDT Tue May 21 2024

Already one round of heavy rainfall moved through the state last
night with 3 to 5 inches of rainfall in some areas with isolated
higher amounts that led to flash flooding. Severe storms also moved
over southern and parts of central Iowa in the morning hours. As a
shortwave trough lifts northeastward and negatively tilts this
afternoon, latest Warn on Forecast System (WoFS) is showing
good airmass recovery with dewpoints rising 5 or so degrees
ahead of a surface triple point. Low level kinematics are
already strong and mid-levels are increasing as well. As the
airmass recovers, WoFS shows strong instability with MLCAPE
growing above 1500 J/kg and very favorable 0-500m and 0-1km SRH
ahead of it as well. Hodographs show a bit more linear
depiction, but initially they may be able to remain curved in
the low levels. Therefore, concern and confidence remain high of
rotating storms capable of tornadoes, including a few strong
given the Particularly Dangerous Situation Tornado Watch issued
earlier, damaging wind gusts including the potential of a few
intense wind gusts (greater than 75 mph), and large hail larger
than golf ball size. The hail size can be greater with rotating
storms as hailstones recycle in the updraft. Rainfall with
these storms of 1 to 2 inches will be possible and could cause
new flash flooding or prolong or renew flooding with rivers
rising as well from the recent and future rainfall. Storms will
move quickly through our area this afternoon and be largely east
of a Waterloo to Ottumwa line by around 7pm

As we move into this evening, we will enter a several day period of
drier conditions, which will be welcome for saturated soils and
swollen streams. While river flooding will be peaking mid to
late this week, no substantial rainfall is forecast until
Thursday night into Friday. This is when the next shortwave
trough will approach and pass north of the region and bring
thunderstorms through the state. The timing may mitigate a wider
severe risk, but instability and shear may be sufficient for a
few strong to severe storms.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1235 PM CDT Tue May 21 2024

Main concern is severe thunderstorms that may have large hail
and damaging wind gusts this afternoon. TEMPO lines are for best
timing of storms with impacts that may need more limited as the
storms move through than currently shown. Winds are gusty from
the southeast early this afternoon, but will stay gusty as they
become from the northwest behind the storms. A return to VFR
conditions is forecast into tonight.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 7 PM CDT this evening for IAZ004>007-015>017-
023>028-033>039-044>050-057>062-070>075-081>083-092.

&&

DISCUSSION...Ansorge
AVIATION...Ansorge

Hazardous weather outlook, May 21, 2:15 PM CDT, 1 hour 40 minutes before

Hazardous Weather Outlook
National Weather Service Des Moines IA
215 PM CDT Tue May 21 2024

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097-221915-
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun-
Webster-Hamilton-Hardin-Grundy-Black Hawk-Crawford-Carroll-Greene-
Boone-Story-Marshall-Tama-Audubon-Guthrie-Dallas-Polk-Jasper-
Poweshiek-Cass-Adair-Madison-Warren-Marion-Mahaska-Adams-Union-
Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne-
Appanoose-Davis-
215 PM CDT Tue May 21 2024

This Hazardous Weather Outlook is for portions of central Iowa,
north central Iowa, northeast Iowa, northwest Iowa, south central
Iowa, southeast Iowa, southwest Iowa, and west central Iowa.

.DAY ONE...This Afternoon and Tonight

A cold front that will be moving eastward across the state of Iowa
to generate a line of strong-severe storms during the afternoon
and evening hours with tornadoes, damaging winds, flash flooding,
and large hail all possible with the strongest storms. The worst
of the storms will be primarily during the 3 pm to 9 pm timeframe.
Winds could gust over 40 mph at times this evening as the storms
move off to the east.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Additional thunderstorm chances return at times Friday and
through the weekend. The severe weather potential for these days
will be better determined in the coming days.

.SPOTTER INFORMATION STATEMENT...

In the hours before

Local storm report, May 21, 3:35 PM CDT, 20 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
335 PM CDT Tue May 21 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0313 PM     Tornado          2 NNE Corning           41.01N 94.72W
05/21/2024                   Adams              IA   Broadcast Media

            Reports of structure damage near Corning.

&&

Local storm report, May 21, 3:42 PM CDT, 13 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
342 PM CDT Tue May 21 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0333 PM     Tornado          1 ENE Carbon            41.05N 94.81W
05/21/2024                   Adams              IA   Public

            Social media report of tornado damage,
            windmill knocked down and on fire.

&&

AB

Local storm report, May 21, 3:48 PM CDT, 7 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
348 PM CDT Tue May 21 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0346 PM     Hail             1 N Creston             41.07N 94.37W
05/21/2024  M0.50 Inch       Union              IA   Public

&&

MP

Local storm report, May 21, 3:49 PM CDT, 6 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
349 PM CDT Tue May 21 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0345 PM     Tornado          Greenfield              41.31N 94.46W
05/21/2024                   Adair              IA   Emergency Mngr

            Damage in Greenfield.

&&

Local storm report, May 21, 3:51 PM CDT, 4 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
351 PM CDT Tue May 21 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0330 PM     Tstm Wnd Dmg     3 N Williamson          41.13N 93.26W
05/21/2024                   Lucas              IA   Storm Chaser

            Damage reported Vehicles flipped, windmills
            on ground. 1 windmill on fire.

&&

Local storm report, May 21, 3:53 PM CDT, 2 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
353 PM CDT Tue May 21 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0347 PM     Funnel Cloud     2 WSW Callender         42.35N 94.34W
05/21/2024                   Webster            IA   Trained Spotter

&&

MP

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 20, 8:25 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DMX	Palo Alto, Pocahontas	50 min
May 20, 8:48 PM CDT	Severe Thunderstorm Warning	DMX	Hancock, Kossuth, Winnebago	42 min
May 20, 9:12 PM CDT	River Flood Watch	DMX	Black Hawk	24 hr
May 20, 9:13 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DMX	Humboldt, Kossuth, Palo Alto, Pocahontas	37 min
May 20, 9:30 PM CDT	Severe Thunderstorm Warning	DMX	Hancock, Winnebago, Worth	22 min
May 20, 10:20 PM CDT	Special Weather Statement	DMX	Hancock	25 min
May 20, 10:35 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth	25 min
May 20, 10:40 PM CDT	Special Weather Statement	DMX	Palo Alto, Pocahontas	35 min
May 20, 11:02 PM CDT	Severe Thunderstorm Warning	DMX	Palo Alto, Pocahontas	28 min
May 20, 11:16 PM CDT	Flash Flood Warning	DMX	Hancock, Kossuth, Winnebago	6 hr
May 20, 11:30 PM CDT	Special Weather Statement	DMX	Carroll	30 min
May 20, 11:34 PM CDT	Special Weather Statement	DMX	Guthrie	26 min
May 20, 11:58 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Calhoun, Carroll, Dallas, Greene, Guthrie and 2 more	36 min
May 21, 12:06 AM CDT	Special Weather Statement	DMX	Pocahontas	24 min
May 21, 12:10 AM CDT	Special Weather Statement	DMX	Hancock	35 min
May 21, 1:09 AM CDT	Severe Thunderstorm Warning	DMX	Audubon, Carroll, Crawford	66 min
May 21, 1:20 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Polk	40 min
May 21, 2:15 AM CDT	Special Weather Statement	DMX	Audubon, Guthrie	60 min
May 21, 2:32 AM CDT	Special Weather Statement	DMX	Black Hawk, Tama	28 min
May 21, 2:38 AM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Butler, Grundy, Hardin	37 min
May 21, 2:56 AM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Bremer, Butler	49 min
May 21, 3:09 AM CDT	Flash Flood Warning	DMX	Butler, Franklin, Grundy, Hardin, Wright	8 hr
May 21, 3:22 AM CDT	Severe Thunderstorm Warning	DMX	Carroll, Crawford, Sac	38 min
May 21, 3:26 AM CDT	Flash Flood Warning	DMX	Adair, Audubon, Cass, Guthrie	8 hr
May 21, 4:12 AM CDT	Special Weather Statement	DMX	Polk	33 min
May 21, 4:22 AM CDT	Flash Flood Warning	DMX	Boone, Dallas, Greene, Guthrie, Jasper, Marshall and 2 more	7 hr
May 21, 5:09 AM CDT	Areal Flood Warning	DMX	Hancock, Kossuth, Winnebago	14 hr
May 21, 5:25 AM CDT	Severe Thunderstorm Warning	DMX	Poweshiek, Tama	50 min
May 21, 5:51 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Poweshiek, Tama	39 min
May 21, 6:18 AM CDT	Severe Thunderstorm Warning	DMX	Poweshiek, Tama	42 min
May 21, 6:26 AM CDT	Flash Flood Warning	DMX	Jasper, Marshall, Poweshiek, Tama	5 hr
May 21, 6:28 AM CDT	Severe Thunderstorm Warning Considerable damage threat	DMX	Carroll, Crawford, Sac	47 min
May 21, 6:51 AM CDT	Severe Thunderstorm Warning	DMX	Audubon, Carroll, Cass, Crawford, Guthrie	54 min
May 21, 7:07 AM CDT	Severe Thunderstorm Warning Considerable damage threat	DMX	Cass	23 min
May 21, 7:24 AM CDT	Tornado Warning	DMX	Adair, Cass	36 min
May 21, 7:29 AM CDT	Severe Thunderstorm Warning Considerable damage threat	DMX	Adair, Audubon, Cass, Guthrie	46 min
May 21, 7:35 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Adams, Cass, Taylor	40 min
May 21, 8:05 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Dallas, Guthrie, Madison	55 min
May 21, 8:41 AM CDT	Severe Thunderstorm Warning Considerable damage threat	DMX	Dallas, Madison, Polk, Warren	64 min
May 21, 8:57 AM CDT	Flash Flood Warning	DMX	Black Hawk, Bremer, Grundy, Hardin, Marshall, Tama	2 hr
May 21, 9:26 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Mahaska, Marion, Marshall, Polk, Poweshiek and 2 more	64 min
May 21, 10:09 AM CDT	River Flood Warning	DMX	Cass	15 hr
May 21, 11:14 AM CDT	River Flood Watch	DMX	Polk	4 days
May 21, 11:14 AM CDT	River Flood Watch	DMX	Webster	9 hr
May 21, 11:14 AM CDT	River Flood Watch	DMX	Polk	5 days
May 21, 11:14 AM CDT	River Flood Watch	DMX	Dallas, Greene	4 days
May 21, 11:14 AM CDT	River Flood Watch	DMX	Boone, Hamilton, Webster	47 hr
May 21, 11:14 AM CDT	River Flood Warning	DMX	Tama	8 days
May 21, 11:14 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Mahaska, Marion, Poweshiek	46 min
May 21, 11:16 AM CDT	Areal Flood Warning	DMX	Black Hawk, Bremer, Butler, Franklin, Grundy, Hardin and 6 more	24 hr
May 21, 11:54 AM CDT	Severe Thunderstorm Warning Considerable damage threat	DMX	Poweshiek	21 min
May 21, 1:38 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	52 min
May 21, 2:18 PM CDT	Severe Thunderstorm Warning	DMX	Sac	29 min
May 21, 2:28 PM CDT	Severe Thunderstorm Warning	DMX	Adams, Audubon, Cass	62 min
May 21, 2:30 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Calhoun, Carroll, Crawford, Sac	45 min
May 21, 2:52 PM CDT	Tornado Warning	DMX	Adams, Cass	18 min
May 21, 2:55 PM CDT	Tornado Warning	DMX	Adair, Adams, Cass, Union	50 min
May 21, 2:57 PM CDT	Flash Flood Warning	DMX	Adair, Audubon, Carroll, Cass, Crawford, Greene and 1 more	6 hr
May 21, 3:07 PM CDT	Tornado Warning	DMX	Adair, Adams, Madison, Taylor, Union	53 min
May 21, 3:11 PM CDT	Severe Thunderstorm Warning Considerable damage threat	DMX	Audubon, Boone, Calhoun, Carroll, Greene, Guthrie and 1 more	49 min
May 21, 3:13 PM CDT	Tornado Warning	DMX	Audubon, Cass, Greene, Guthrie	22 min
May 21, 3:20 PM CDT	River Flood Warning	DMX	Polk	7 hr
May 21, 3:26 PM CDT	River Flood Warning	DMX	Polk	4 days
May 21, 3:26 PM CDT	River Flood Warning	DMX	Polk	4 days
May 21, 3:26 PM CDT	Tornado Warning Tornado observed	DMX	Adair, Adams, Madison, Union	49 min
May 21, 3:31 PM CDT	Severe Thunderstorm Warning Destructive damage threat	DMX	Boone, Greene, Hamilton, Webster, Wright	44 min
May 21, 3:33 PM CDT	Tornado Warning	DMX	Ringgold, Taylor, Union	42 min
May 21, 3:35 PM CDT	Tornado Warning Tornado observedConsiderable damage threat	DMX	Adair, Dallas, Guthrie, Madison	40 min
May 21, 3:40 PM CDT	Tornado Warning Tornado observed	DMX	Adair, Adams, Dallas, Madison, Ringgold, Union	50 min
May 21, 3:58 PM CDT	Tornado Warning	DMX	Clarke, Decatur, Lucas, Ringgold, Union, Warren	47 min
May 21, 4:01 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Greene, Guthrie, Hamilton, Webster	44 min
May 21, 4:03 PM CDT	Tornado Warning	DMX	Boone, Hamilton, Webster	42 min
May 21, 4:11 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Clarke, Dallas, Decatur, Lucas, Madison and 4 more	64 min
May 21, 4:11 PM CDT	Severe Thunderstorm Warning	DMX	Hancock, Kossuth, Winnebago, Worth	49 min
May 21, 4:15 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Franklin, Hancock, Worth, Wright	45 min
May 21, 4:19 PM CDT	Tornado Warning	DMX	Boone, Dallas, Polk, Story	41 min
May 21, 4:25 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Franklin, Grundy, Hamilton, Hardin, Marshall and 2 more	50 min
May 21, 4:30 PM CDT	Tornado Warning	DMX	Jasper, Madison, Polk, Warren	45 min
May 21, 4:43 PM CDT	Severe Thunderstorm Warning	DMX	Grundy, Hardin, Jasper, Marion, Marshall, Polk and 2 more	47 min
May 21, 4:46 PM CDT	Tornado Warning	DMX	Franklin, Grundy, Hamilton, Hardin	17 min

Nearby

Tornado Warnings in Iowa, 2024 Every tornado warning in 2024 Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.