Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 78, NWS Des Moines, IA

July 14, 2021Tama County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 14, 2021, 7:29 PM CDT for Tama County, Iowa. It was in force for 14 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 14, 2021, 7:29 PM CDT (00:29 UTC)
Expired: Jul 14, 2021, 7:43 PM CDT
In force: 14 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

County Tama County, IA

The radar

The Des Moines radar (KDMX), 114 km from the middle of the area, began a volume at 00:27 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 watch it was issued in

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

Issued	Product	Office	Lasted
Jul 14, 2:35 PM CDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.5 hours before the alert went out and 167 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: 2569 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 832 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 253 m²/s²
0-3 km storm-relative helicity: 346 m²/s²
Significant tornado parameter: 3.2
Supercell composite: 23.4

Open this sounding in Storm Lab

The text

As transmitted.

606 
WUUS53 KDMX 150029
SVRDMX
IAC171-150100-
/O.NEW.KDMX.SV.W.0078.210715T0029Z-210715T0100Z/

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

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  East central Tama County in central Iowa...

* Until 800 PM CDT.

* At 729 PM CDT, a severe thunderstorm was located 7 miles southwest
  of Dysart, or 11 miles northeast of Toledo, moving east at 40 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

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

* This severe thunderstorm will be near...
  Dysart around 740 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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

&&

LAT...LON 4200 9250 4214 9251 4219 9230 4201 9230
TIME...MOT...LOC 0029Z 257DEG 35KT 4207 9238 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

Fowle

1 follow-up statement

917 
WWUS53 KDMX 150043
SVSDMX

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

IAC171-150053-
/O.CAN.KDMX.SV.W.0078.000000T0000Z-210715T0100Z/
Tama IA-
743 PM CDT Wed Jul 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL TAMA COUNTY IS
CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

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

LAT...LON 4200 9250 4214 9251 4219 9230 4201 9230
TIME...MOT...LOC 0042Z 257DEG 35KT 4210 9220 

$$

Fowle

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 14, 7:03 PM CDT	Special Weather Statement	DMX	Story	42 min
Jul 14, 7:23 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Polk, Story	67 min
Jul 14, 8:10 PM CDT	Tornado Warning	DMX	Marshall	35 min
Jul 14, 8:28 PM CDT	Flash Flood Warning	DMX	Marshall, Polk, Story	6 hr
Jul 14, 8:42 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Polk, Story	43 min
Jul 14, 8:45 PM CDT	Severe Thunderstorm Warning	DMX	Poweshiek, Tama	45 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.