Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 75, NWS Des Moines, IA

July 14, 20214 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 14, 2021, 5:49 PM CDT for 4 counties in Iowa. It was in force for 41 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
Jul 14, 2021, 5:49 PM CDT (22:49 UTC)
Expired
Jul 14, 2021, 6:30 PM CDT
In force
41 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Black Hawk County, IA, Bremer County, IA, Butler County, IA, Grundy County, IA

The radar

The Des Moines radar (KDMX), 144 km from the middle of the area, began a volume at 22:50 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
Jul 14, 6:17 PM CDTTSTM WND DMGWaterloo, IANUMEROUS TREES DOWN. TIME ESTIMATED FROM RADAR.
Jul 14, 6:19 PM CDTTORNADO1 Nw Waterloo, IABRIEF TORNADO REPORTED NEAR THE JOHN DEERE FACILITY WITH DAMAGE REPORTED NEAR US 218.
Jul 14, 6:19 PM CDTTORNADO1 Nw Waterloo, IADELAYED REPORT - BRIEF TORNADO TOUCHDOWN NEAR JOHN DEERE COMPLEX WITH SOME DAMAGE EITHER SIDE OF US 218.
Jul 14, 6:19 PM CDTTORNADO1 Nw Waterloo, IADELAYED REPORT: BRIEF TORNADO TOUCHDOWN NEAR JOHN DEERE COMPLEX WITH SOME DAMAGE REPORTED EITHER SIDE OF US 218 FROM MAYNARD & ANSBOROUGH AVE SOUTH TOWARD WESTFILED AVE.
Jul 14, 6:22 PM CDTTSTM WND DMGWaterloo, IATREES DOWN. TIME ESTIMATED.

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
Jul 14, 2:35 PM CDTTornado WatchSPC8 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.8 hours before the alert went out and 179 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, Davenport, at 12:00Z on 2021-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 573 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, Davenport, at 12:00Z on 2021-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 square meters per square second.19395878Sfc1 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
573 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
1106 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
108 m²/s²
0-3 km storm-relative helicity
139 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

As transmitted.

879 
WUUS53 KDMX 142249
SVRDMX
IAC013-017-023-075-142330-
/O.NEW.KDMX.SV.W.0075.210714T2249Z-210714T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
549 PM CDT Wed Jul 14 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Black Hawk County in northeastern Iowa...
  Southern Bremer County in northeastern Iowa...
  Northeastern Grundy County in central Iowa...
  Southeastern Butler County in north central Iowa...

* Until 630 PM CDT.

* At 548 PM CDT, severe thunderstorms were located along a line
  extending from near Denver to Waterloo Municipal Airport to Hudson,
  moving east at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Waterloo, Cedar Falls, Evansdale, Jesup, Hudson, Dike, Elk Run
  Heights, Crossroads Mall, Waterloo Municipal Airport, Uni-Dome And
  McLeod Center, Janesville, Washburn, Dunkerton, Raymond,
  Gilbertville, New Hartford and George Wyth State Park.

This includes Interstate 380 between mile markers 60 and 73.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 900 PM CDT for central, north
central and northeastern Iowa.

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

&&

LAT...LON 4243 9264 4265 9263 4266 9208 4247 9208
      4247 9206 4238 9207
TIME...MOT...LOC 2248Z 251DEG 30KT 4265 9244 4255 9242 4244 9243 

HAIL...<.75IN
WIND...60MPH
 
$$

Fowle
1 follow-up statement
031 
WWUS53 KDMX 142320
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
620 PM CDT Wed Jul 14 2021

IAC023-142329-
/O.CAN.KDMX.SV.W.0075.000000T0000Z-210714T2330Z/
Butler IA-
620 PM CDT Wed Jul 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BUTLER 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 900 PM CDT for central and
northeastern Iowa.

LAT...LON 4242 9257 4251 9248 4266 9234 4266 9208
      4247 9208 4247 9206 4238 9207
TIME...MOT...LOC 2319Z 269DEG 28KT 4265 9222 4256 9225 4245 9241 

$$

IAC013-017-075-142330-
/O.CON.KDMX.SV.W.0075.000000T0000Z-210714T2330Z/
Black Hawk IA-Bremer IA-Grundy IA-
620 PM CDT Wed Jul 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM CDT
FOR CENTRAL BLACK HAWK...SOUTHEASTERN BREMER AND EAST CENTRAL GRUNDY
COUNTIES...

At 619 PM CDT, severe thunderstorms were located along a line
extending from near Denver to 6 miles north of Elk Run Heights to
near Hudson, moving east at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Waterloo, Cedar Falls, Evansdale, Jesup, Hudson, Denver, Elk Run
Heights, Crossroads Mall, Waterloo Municipal Airport, Uni-Dome And
McLeod Center, Washburn, Dunkerton, Raymond, Gilbertville and George
Wyth State Park.

This includes Interstate 380 between mile markers 60 and 73.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 900 PM CDT for central and
northeastern Iowa.

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

&&

LAT...LON 4242 9257 4251 9248 4266 9234 4266 9208
      4247 9208 4247 9206 4238 9207
TIME...MOT...LOC 2319Z 269DEG 28KT 4265 9222 4256 9225 4245 9241 

HAIL...<.75IN
WIND...60MPH
 
$$

Fowle

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 7:17 AM CDTSpecial Weather StatementDMXEmmet, Humboldt, Kossuth, Palo Alto, Pocahontas58 min
Jul 14, 8:08 AM CDTSevere Thunderstorm WarningDMXKossuth, Winnebago52 min
Jul 14, 8:24 AM CDTSpecial Weather StatementDMXButler, Cerro Gordo, Franklin, Hancock, Winnebago, Worth66 min
Jul 14, 8:39 AM CDTSevere Thunderstorm WarningDMXButler, Cerro Gordo, Franklin, Grundy, Hancock, Hardin and 1 more66 min
Jul 14, 8:43 AM CDTSevere Thunderstorm WarningDMXCerro Gordo, Hancock, Winnebago, Worth62 min
Jul 14, 8:49 AM CDTSevere Thunderstorm WarningDMXGrundy, Hardin, Marshall, Story, Tama56 min
Jul 14, 9:40 AM CDTSpecial Weather StatementDMXBlack Hawk, Bremer, Tama65 min
Jul 14, 3:55 PM CDTTornado WarningDMXCalhoun, Carroll, Greene35 min
Jul 14, 4:04 PM CDTTornado WarningDMXBoone, Hamilton, Story, Webster41 min
Jul 14, 4:23 PM CDTTornado WarningDMXFranklin, Hamilton, Hardin, Wright37 min
Jul 14, 4:29 PM CDTTornado Warning Tornado observedDMXCalhoun, Greene, Webster31 min
Jul 14, 4:29 PM CDTTornado Warning Tornado observedDMXHamilton, Hardin31 min
Jul 14, 4:30 PM CDTTornado WarningDMXButler30 min
Jul 14, 4:35 PM CDTTornado WarningDMXFranklin, Hardin40 min
Jul 14, 4:53 PM CDTTornado WarningDMXBremer, Butler37 min
Jul 14, 4:56 PM CDTTornado Warning Tornado observedDMXHamilton, Hardin25 min
Jul 14, 5:00 PM CDTTornado WarningDMXHamilton, Hardin, Story25 min
Jul 14, 5:18 PM CDTSevere Thunderstorm WarningDMXBlack Hawk, Bremer, Butler42 min
Jul 14, 5:18 PM CDTSevere Thunderstorm WarningDMXGrundy, Hardin42 min
Jul 14, 5:23 PM CDTTornado Warning Tornado observedDMXBlack Hawk, Bremer, Butler37 min
Jul 14, 5:50 PM CDTTornado WarningDMXCerro Gordo25 min
Jul 14, 5:53 PM CDTTornado Warning Tornado observedDMXBlack Hawk, Bremer37 min
Jul 14, 5:58 PM CDTTornado WarningDMXCalhoun47 min
Jul 14, 6:02 PM CDTTornado WarningDMXBlack Hawk, Grundy, Marshall, Tama43 min
Jul 14, 6:42 PM CDTSevere Thunderstorm WarningDMXTama48 min
Jul 14, 6:42 PM CDTTornado WarningDMXWebster36 min
Jul 14, 6:55 PM CDTTornado WarningDMXTama19 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.