Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 127, NWS Des Moines, IA

December 15, 202112 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Dec 15, 2021, 5:52 PM CST for 12 counties in Iowa. It was in force for 53 min. 6 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
Dec 15, 2021, 5:52 PM CST (23:52 UTC)
Expired
Dec 15, 2021, 6:45 PM CST
In force
53 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Damage threat
Destructive
Hail
0.75 in
Wind
80.0 mph

Counties Boone County, IA, Franklin County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Humboldt County, IA, Kossuth County, IA, Marshall County, IA, Story County, IA, Webster County, IA, Winnebago County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 104 km from the middle of the area, began a volume at 23:56 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

TimeReportWhereRemark
Dec 15, 6:08 PM CSTTSTM WND GST 582 S Ames, IA
Dec 15, 6:13 PM CSTTSTM WND GST 70Gilbert, IA
Dec 15, 6:23 PM CSTTSTM WND DMG2 N Galt, IABARN WALL COLLAPSED, TREE DAMAGE. REPORT FROM BROADCAST MEDIA. TIME ESTIMATED VIA RADAR.
Dec 15, 6:25 PM CSTTSTM WND DMGBelmond, IA3 TO 4 OUTBUILDINGS COMPLETELY DESTROYED NEAR BELMOND. TIME ESTIMATED BY RADAR.
Dec 15, 6:27 PM CSTTSTM WND DMGMaxwell, IALARGE TREE ON HOME. TIME ESTIMATED VIA RADAR.
Dec 15, 6:32 PM CSTHAIL 12 Wnw Coulter, IAQUARTER SIZE HAIL REPORTED AT HWY 3 AND INTERSTATE 35.

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

The watch it was issued in

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

IssuedProductOfficeLasted
Dec 15, 1:23 PM CSTTornado WatchSPC7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 11.9 hours before the alert went out and 245 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-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2021-12-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 2021-12-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 251 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
1 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
455 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
251 m²/s²
0-3 km storm-relative helicity
291 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

818 
WUUS53 KDMX 152352
SVRDMX
IAC015-069-079-081-083-091-109-127-169-187-189-197-160045-
/O.NEW.KDMX.SV.W.0127.211215T2352Z-211216T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
552 PM CST Wed Dec 15 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Story County in central Iowa...
  Marshall County in central Iowa...
  Hardin County in central Iowa...
  Northeastern Webster County in central Iowa...
  Wright County in north central Iowa...
  Western Franklin County in north central Iowa...
  Eastern Kossuth County in north central Iowa...
  Hancock County in north central Iowa...
  Eastern Humboldt County in north central Iowa...
  Eastern Boone County in central Iowa...
  Hamilton County in central Iowa...
  Winnebago County in north central Iowa...

* Until 645 PM CST.

* At 552 PM CST, severe thunderstorms were located along a line
  extending from near Swan Lake to near Slater, moving northeast at
  85 mph.

  THESE ARE DESTRUCTIVE STORMS FOR portions of central and northern 
iowa.

  HAZARD...80 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be heavily damaged. Expect 
           considerable damage to roofs, windows, and vehicles. 
           Extensive tree damage and power outages are likely.

* Severe thunderstorms will be near...
  Slater and Iowa State Center around 555 PM CST.
  Ames, Nevada and Huxley around 600 PM CST.

Other locations in the path of these severe thunderstorms include
State Center.

This includes Interstate 35 between mile markers 102 and 178.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

A Tornado Watch remains in effect until 800 PM CST for central and
north central Iowa.

&&

LAT...LON 4350 9365 4322 9350 4291 9350 4291 9333
      4230 9300 4221 9300 4221 9295 4186 9277
      4186 9377 4221 9387 4221 9393 4350 9427
TIME...MOT...LOC 2352Z 244DEG 72KT 4335 9460 4193 9373 

THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Cogil
1 follow-up statement
993 
WWUS53 KDMX 160034
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
634 PM CST Wed Dec 15 2021

IAC091-187-160044-
/O.CAN.KDMX.SV.W.0127.000000T0000Z-211216T0045Z/
Webster IA-Humboldt IA-
634 PM CST Wed Dec 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN WEBSTER AND
EASTERN HUMBOLDT COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 800 PM CST for central and
north central Iowa.

LAT...LON 4350 9365 4322 9350 4291 9350 4291 9333
      4230 9300 4221 9300 4221 9295 4186 9277
      4186 9372 4255 9360 4326 9415 4350 9427
TIME...MOT...LOC 0034Z 270DEG 72KT 4370 9360 4228 9274 

$$

IAC015-069-079-081-083-109-127-169-189-197-160045-
/O.CON.KDMX.SV.W.0127.000000T0000Z-211216T0045Z/
Story IA-Marshall IA-Hardin IA-Wright IA-Franklin IA-Kossuth IA-
Hancock IA-Boone IA-Hamilton IA-Winnebago IA-
634 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM CST
FOR STORY...MARSHALL...HARDIN...EASTERN WRIGHT...WESTERN FRANKLIN...
NORTHEASTERN KOSSUTH...HANCOCK...SOUTHEASTERN BOONE...EASTERN
HAMILTON AND WINNEBAGO COUNTIES...

At 634 PM CST, severe thunderstorms were located along a line
extending from near Alden to near Grundy Center, moving east at 85
mph.

HAZARD...70 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

These severe thunderstorms will remain over mainly rural areas of
Story, Marshall, Hardin, eastern Wright, western Franklin,
northeastern Kossuth, Hancock, southeastern Boone, eastern Hamilton
and Winnebago Counties, including the following locations... Wesley,
Steamboat Rock, Ferguson, Forest City Municipal Airport, Radcliffe,
Bradford, Maxwell, Cambridge, Melbourne and Buffalo Center.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CST for central and
north central Iowa.

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4350 9365 4322 9350 4291 9350 4291 9333
      4230 9300 4221 9300 4221 9295 4186 9277
      4186 9372 4255 9360 4326 9415 4350 9427
TIME...MOT...LOC 0034Z 270DEG 72KT 4370 9360 4228 9274 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Cogil

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 15, 4:13 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXAdair, Adams, Audubon, Cass, Guthrie, Ringgold and 2 more77 min
Dec 15, 4:16 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXCarroll, Crawford, Sac74 min
Dec 15, 4:37 PM CSTTornado Warning Tornado observedDMXCass23 min
Dec 15, 4:44 PM CSTTornado WarningDMXCrawford36 min
Dec 15, 4:53 PM CSTTornado WarningDMXAdair, Audubon, Cass, Guthrie33 min
Dec 15, 5:07 PM CSTTornado WarningDMXSac27 min
Dec 15, 5:10 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXAdair, Audubon, Boone, Dallas, Greene, Guthrie and 4 more80 min
Dec 15, 5:10 PM CSTTornado WarningDMXCarroll, Crawford35 min
Dec 15, 5:14 PM CSTTornado WarningDMXAudubon, Calhoun, Carroll, Greene, Guthrie31 min
Dec 15, 5:15 PM CSTTornado WarningDMXCalhoun, Carroll, Crawford, Sac30 min
Dec 15, 5:18 PM CSTTornado Warning Tornado observedDMXAdair, Boone, Dallas, Greene, Guthrie42 min
Dec 15, 5:19 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXBoone, Calhoun, Carroll, Emmet, Greene, Humboldt and 5 more71 min
Dec 15, 5:22 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXCarroll, Crawford, Sac23 min
Dec 15, 5:22 PM CSTSevere Thunderstorm Warning Considerable damage threatDMXAdair, Adams, Clarke, Decatur, Madison, Ringgold and 3 more68 min
Dec 15, 5:36 PM CSTTornado WarningDMXCalhoun, Humboldt, Kossuth, Palo Alto, Pocahontas24 min
Dec 15, 5:38 PM CSTTornado Warning Tornado observedDMXBoone, Calhoun, Greene, Hamilton, Webster37 min
Dec 15, 5:45 PM CSTTornado WarningDMXCalhoun, Pocahontas, Webster30 min
Dec 15, 5:58 PM CSTTornado WarningDMXHancock, Humboldt, Kossuth, Palo Alto, Pocahontas32 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021Every severe thunderstorm warning in 2021

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.