Alert archive / Iowa / Tornado Warnings in 2021

Tornado Warning 26, NWS Des Moines, IA

August 8, 2021Pocahontas County, Iowa

NWS Des Moines, IA issued this tornado warning at Aug 8, 2021, 8:36 PM CDT for Pocahontas County, Iowa. It was in force for 24 min. 3 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: Aug 8, 2021, 8:36 PM CDT (01:36 UTC)
Expired: Aug 8, 2021, 9:00 PM CDT
In force: 24 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

County Pocahontas County, IA

The radar

The Des Moines radar (KDMX), 134 km from the middle of the area, began a volume at 01:38 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
Aug 8, 8:41 PM CDT	FUNNEL CLOUD	2 N Fonda, IA
Aug 8, 8:49 PM CDT	FUNNEL CLOUD	4 Ene Fonda, IA
Aug 8, 8:56 PM CDT	FUNNEL CLOUD	3 Ene Fonda, IA	TIME AND LOCATION ESTIMATED BY RADAR.

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

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.6 hours before the alert went out and 194 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: 1733 J/kg
Mixed-layer CIN: -130 J/kg
Mixed-layer LCL: 1356 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 104 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 6.0

Open this sounding in Storm Lab

The text

As transmitted.

140 
WFUS53 KDMX 090136
TORDMX
IAC151-090200-
/O.NEW.KDMX.TO.W.0026.210809T0136Z-210809T0200Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
836 PM CDT Sun Aug 8 2021

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Southwestern Pocahontas County in northwestern Iowa...

* Until 900 PM CDT.
    
* At 836 PM CDT, a severe thunderstorm capable of producing a tornado
  was located 8 miles east of Newell, or 11 miles southwest of
  Pocahontas, moving southeast at 20 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This tornadic thunderstorm will remain over mainly rural areas of
  southwestern Pocahontas County, including the following
  locations... Fonda.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4269 9483 4256 9463 4256 9486 4264 9490
TIME...MOT...LOC 0136Z 318DEG 16KT 4263 9483 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

Cogil

1 follow-up statement

210 
WWUS53 KDMX 090149
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
849 PM CDT Sun Aug 8 2021

IAC151-090200-
/O.CON.KDMX.TO.W.0026.000000T0000Z-210809T0200Z/
Pocahontas IA-
849 PM CDT Sun Aug 8 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 900 PM CDT FOR
SOUTHWESTERN POCAHONTAS COUNTY...
    
At 848 PM CDT, a severe thunderstorm capable of producing a tornado
was located 9 miles southwest of Pocahontas, moving southeast at 20
mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornadic thunderstorm will remain over mainly rural areas of
southwestern Pocahontas County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4256 9463 4256 9482 4264 9484 4266 9478
TIME...MOT...LOC 0148Z 301DEG 16KT 4262 9477 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

Cogil

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 8, 9:02 PM CDT	Tornado Warning	DMX	Calhoun, Pocahontas	31 min
Aug 8, 10:39 PM CDT	Special Weather Statement	DMX	Webster	51 min
Aug 8, 11:00 PM CDT	Tornado Warning	DMX	Webster	30 min
Aug 8, 11:30 PM CDT	Tornado Warning Tornado observed	DMX	Webster	30 min
Aug 8, 11:52 PM CDT	Tornado Warning	DMX	Boone, Webster	38 min
Aug 9, 12:23 AM CDT	Tornado Warning	DMX	Butler, Franklin	20 min
Aug 9, 12:29 AM CDT	Severe Thunderstorm Warning	DMX	Boone, Hamilton, Webster	46 min

Nearby

Tornado Warnings in Iowa, 2021 Every tornado warning in 2021 Tornadoes 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.