Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 132, NWS Des Moines, IA

December 15, 202111 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Dec 15, 2021, 7:09 PM CST for 11 counties in Iowa. It was in force for 66 min. 7 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, 7:09 PM CST (01:09 UTC)
Expired: Dec 15, 2021, 8:15 PM CST
In force: 66 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Possible
Damage threat: Considerable
Hail: 0.75 in
Wind: 70.0 mph

Counties Appanoose County, IA, Davis County, IA, Jasper County, IA, Lucas County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Poweshiek County, IA, Wapello County, IA, Wayne County, IA

The radar

The Des Moines radar (KDMX), 105 km from the middle of the area, began a volume at 01:09 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
Dec 15, 7:15 PM CST	TSTM WND GST 60	2 Wsw Pella, IA	PEAK WIND GUST FROM KPEA.
Dec 15, 7:16 PM CST	TSTM WND GST 70	Oskaloosa, IA	SPOTTER REPORTS 60 TO 70 MPH WINDS AND POWER FLASHES. RELAYED REPORT FROM DVN.
Dec 15, 7:20 PM CST	TSTM WND DMG	Centerville, IA	LARGE TREE PARTIALLY UPROOTED AND ON A HOME, METAL BUILDING FLIPPED. TIME ESTIMATED VIA RADAR.
Dec 15, 7:25 PM CST	TSTM WND DMG	5 W Malcom, IA	2 SEMIS OVERTURNED ON I80 WB NEAR THE 185 TO 186 MM, JUST EAST OF GRINNELL.
Dec 15, 7:27 PM CST	TSTM WND GST 65	Centerville, IA	60-70 MPH WIND NEAR CENTERVILLE. REPORT VIA SOCIAL MEDIA AND TIME ESTIMATED BY RADAR.
Dec 15, 7:52 PM CST	TSTM WND GST 60	3 Wnw Fremont, IA	REPORTED AT OSKALOOSA MUNICIPAL AIRPORT.
Dec 15, 7:54 PM CST	TSTM WND GST 82	4 Se Kirkville, IA	PEAK WIND GUST AT OTTUMWA (KOTM).

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.

Issued	Product	Office	Lasted
Dec 15, 1:23 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.2 hours before the alert went out and 181 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: 229 J/kg
Mixed-layer CIN: -358 J/kg
Mixed-layer LCL: 1061 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 433 m²/s²
0-3 km storm-relative helicity: 496 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

214 
WUUS53 KDMX 160109
SVRDMX
IAC007-051-099-117-123-125-127-135-157-179-185-160215-
/O.NEW.KDMX.SV.W.0132.211216T0109Z-211216T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
709 PM CST Wed Dec 15 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Monroe County in south central Iowa...
  Eastern Lucas County in south central Iowa...
  Poweshiek County in central Iowa...
  Southeastern Marshall County in central Iowa...
  Davis County in southeastern Iowa...
  Wapello County in southeastern Iowa...
  Eastern Marion County in south central Iowa...
  Eastern Wayne County in south central Iowa...
  Mahaska County in south central Iowa...
  Appanoose County in south central Iowa...
  Eastern Jasper County in central Iowa...

* Until 815 PM CST.

* At 708 PM CST, severe thunderstorms were located along a line
  extending from near Grinnell to 11 miles west of Unionville, moving
  east at 65 mph.

  HAZARD...70 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Ottumwa, Oskaloosa, Pella, Grinnell, Knoxville, Centerville, Albia,
  Bloomfield, Montezuma, Brooklyn, New Sharon, Eddyville, Ottumwa
  Industrial Airport, Rock Creek Lake, Lake Sundown, Rathbun Lake,
  Lake Red Rock, Eldon, Victor and Sully.

This includes Interstate 80 between mile markers 170 and 204.
 
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 south central,
central and southeastern Iowa.

&&

LAT...LON 4188 9291 4186 9230 4151 9230 4151 9241
      4116 9241 4116 9218 4060 9218 4058 9331
      4059 9331
TIME...MOT...LOC 0108Z 270DEG 55KT 4180 9273 4053 9321 

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

$$

Martin

2 follow-up statements

037 
WWUS53 KDMX 160137
SVSDMX

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

IAC117-125-127-185-160146-
/O.CAN.KDMX.SV.W.0132.000000T0000Z-211216T0215Z/
Lucas IA-Marshall IA-Marion IA-Wayne IA-
737 PM CST Wed Dec 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN LUCAS...SOUTHEASTERN
MARSHALL...EASTERN MARION AND EASTERN WAYNE 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 south central,
central and southeastern Iowa.

LAT...LON 4187 9275 4186 9230 4151 9230 4151 9241
      4116 9241 4116 9218 4060 9218 4059 9295
TIME...MOT...LOC 0136Z 270DEG 55KT 4180 9215 4053 9264 

$$

IAC007-051-099-123-135-157-179-160215-
/O.CON.KDMX.SV.W.0132.000000T0000Z-211216T0215Z/
Monroe IA-Poweshiek IA-Davis IA-Wapello IA-Mahaska IA-Appanoose IA-
Jasper IA-
737 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CST
FOR EASTERN MONROE...POWESHIEK...DAVIS...WAPELLO...MAHASKA...
APPANOOSE AND SOUTHEASTERN JASPER COUNTIES...

At 736 PM CST, severe thunderstorms were located along a line
extending from near Ladora to near Lancaster, moving east at 65 mph.

HAZARD...70 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Ottumwa, Oskaloosa, Grinnell, Centerville, Albia, Bloomfield,
Montezuma, Brooklyn, New Sharon, Eddyville, Ottumwa Industrial
Airport, Lake Sundown, Rathbun Lake, Eldon, Victor, Fremont, Moravia,
Agency, Moulton and Beacon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CST for south central,
central and southeastern Iowa.

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

&&

LAT...LON 4187 9275 4186 9230 4151 9230 4151 9241
      4116 9241 4116 9218 4060 9218 4059 9295
TIME...MOT...LOC 0136Z 270DEG 55KT 4180 9215 4053 9264 

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

$$

Martin

895 
WWUS53 KDMX 160151
SVSDMX

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

IAC099-160201-
/O.CAN.KDMX.SV.W.0132.000000T0000Z-211216T0215Z/
Jasper IA-
751 PM CST Wed Dec 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN JASPER COUNTY 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 south central,
central and southeastern Iowa.

LAT...LON 4186 9247 4186 9230 4151 9230 4151 9241
      4116 9241 4116 9218 4060 9218 4059 9269
      4131 9266
TIME...MOT...LOC 0151Z 270DEG 55KT 4180 9187 4053 9236 

$$

IAC007-051-123-135-157-179-160215-
/O.CON.KDMX.SV.W.0132.000000T0000Z-211216T0215Z/
Monroe IA-Poweshiek IA-Davis IA-Wapello IA-Mahaska IA-Appanoose IA-
751 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CST
FOR EASTERN MONROE...EASTERN POWESHIEK...DAVIS...WAPELLO...EASTERN
MAHASKA AND EASTERN APPANOOSE COUNTIES...

At 751 PM CST, severe thunderstorms were located along a line
extending from Amana to near Downing, moving east at 65 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Ottumwa, Oskaloosa, Bloomfield, Montezuma, Brooklyn, Eddyville,
Ottumwa Industrial Airport, Eldon, Victor, Fremont, Agency, Moulton,
University Park, Holiday Lake, Blakesburg, Deep River, Pulaski,
Drakesville, Barnes City and Rose Hill.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CST for south central,
central and southeastern Iowa.

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

&&

LAT...LON 4186 9247 4186 9230 4151 9230 4151 9241
      4116 9241 4116 9218 4060 9218 4059 9269
      4131 9266
TIME...MOT...LOC 0151Z 270DEG 55KT 4180 9187 4053 9236 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Martin

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 15, 6:13 PM CST	Severe Thunderstorm Warning	DMX	Appanoose, Clarke, Decatur, Lucas, Marion, Monroe and 2 more	62 min
Dec 15, 6:19 PM CST	Tornado Warning	DMX	Hancock, Kossuth, Winnebago	41 min
Dec 15, 6:24 PM CST	Severe Thunderstorm Warning Considerable damage threat	DMX	Clarke, Dallas, Jasper, Lucas, Madison, Mahaska and 5 more	66 min
Dec 15, 6:30 PM CST	Severe Thunderstorm Warning Considerable damage threat	DMX	Black Hawk, Bremer, Butler, Cerro Gordo, Franklin, Grundy and 6 more	75 min
Dec 15, 6:37 PM CST	Tornado Warning	DMX	Butler, Cerro Gordo, Franklin	20 min
Dec 15, 6:47 PM CST	Severe Thunderstorm Warning Considerable damage threat	DMX	Grundy, Hardin, Marshall, Story	43 min
Dec 15, 7:44 PM CST	Severe Thunderstorm Warning Considerable damage threat	DMX	Black Hawk, Bremer, Butler, Grundy, Tama	27 min
Dec 15, 11:52 PM CST	Wind Advisory	DMX	Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 45 more	6 hr

Nearby

Severe Thunderstorm Warnings in Iowa, 2021 Every 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.