Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 77, NWS Des Moines, IA

July 14, 20214 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 14, 2021, 7:23 PM CDT for 4 counties in Iowa. It was in force for 67 min. 2 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, 7:23 PM CDT (00:23 UTC)
Expired: Jul 14, 2021, 8:30 PM CDT
In force: 67 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Possible
Hail: 1.0 in
Wind: 60.0 mph

Counties Jasper County, IA, Marshall County, IA, Polk County, IA, Story County, IA

The radar

The Des Moines radar (KDMX), 41 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.

What was reported inside it

Time	Report	Where	Remark
Jul 14, 8:15 PM CDT	FUNNEL CLOUD	2 Ese Melbourne, IA	TRAINED SPOTTER REPORTS BRIEF FUNNEL CLOUD 2 MILES ESE OF MELBOURNE.
Jul 14, 8:23 PM CDT	TSTM WND GST 60	4 Se Colo, IA	LARGE TREE BRANCHES DOWN.

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
Jul 14, 2:35 PM CDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.4 hours before the alert went out and 237 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.

360 
WUUS53 KDMX 150023
SVRDMX
IAC099-127-153-169-150130-
/O.NEW.KDMX.SV.W.0077.210715T0023Z-210715T0130Z/

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

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Northeastern Polk County in central Iowa...
  Southeastern Story County in central Iowa...
  Western Marshall County in central Iowa...
  Northwestern Jasper County in central Iowa...

* Until 830 PM CDT.

* At 722 PM CDT, a severe thunderstorm was located near Huxley, or 8
  miles south of Nevada, moving northeast at 30 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Nevada, Huxley, State Center, Baxter, Maxwell, Colo, Melbourne,
  Cambridge, Zearing, Collins, Kelley, Rhodes, Mingo, Laurel,
  Haverhill, Clemons and St. Anthony.

This includes Interstate 35 between mile markers 102 and 111.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4176 9334 4191 9370 4193 9370 4221 9323
      4221 9308 4187 9287
TIME...MOT...LOC 0022Z 247DEG 27KT 4190 9347 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
 
$$

Small

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, 7:29 PM CDT	Severe Thunderstorm Warning	DMX	Tama	14 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.