Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 119, NWS Des Moines, IA

September 20, 2021Appanoose County, Davis County, Wayne County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Sep 20, 2021, 6:34 PM CDT for Appanoose County, Davis County, Wayne County, Iowa. It was in force for 41 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
Sep 20, 2021, 6:34 PM CDT (23:34 UTC)
Expired
Sep 20, 2021, 7:15 PM CDT
In force
41 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Appanoose County, IA, Davis County, IA, Wayne County, IA

The radar

The Des Moines radar (KDMX), 135 km from the middle of the area, began a volume at 23:37 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.

IssuedProductOfficeLasted
Sep 20, 2:07 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.6 hours before the alert went out and 227 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 2021-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 450 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 2021-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -31 square meters per square second.1939Sfc1 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
450 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
567 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-31 m²/s²
0-3 km storm-relative helicity
-25 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

798 
WUUS53 KDMX 202334
SVRDMX
IAC007-051-185-210015-
/O.NEW.KDMX.SV.W.0119.210920T2334Z-210921T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
634 PM CDT Mon Sep 20 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Southwestern Davis County in southeastern Iowa...
  Southeastern Wayne County in south central Iowa...
  Southern Appanoose County in south central Iowa...

* Until 715 PM CDT.

* At 634 PM CDT, a severe thunderstorm was located 10 miles north of
  Unionville, moving east at 35 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...
  Centerville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4071 9319 4083 9251 4060 9249 4058 9316
TIME...MOT...LOC 2334Z 252DEG 31KT 4062 9305 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Donavon
2 follow-up statements
754 
WWUS53 KDMX 202348
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
648 PM CDT Mon Sep 20 2021

IAC185-202357-
/O.CAN.KDMX.SV.W.0119.000000T0000Z-210921T0015Z/
Wayne IA-
648 PM CDT Mon Sep 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WAYNE COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
south central and southeastern Iowa.

LAT...LON 4073 9310 4083 9251 4060 9249 4058 9310
TIME...MOT...LOC 2347Z 252DEG 42KT 4066 9285 

$$

IAC007-051-210015-
/O.CON.KDMX.SV.W.0119.000000T0000Z-210921T0015Z/
Davis IA-Appanoose IA-
648 PM CDT Mon Sep 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM CDT
FOR SOUTHWESTERN DAVIS AND SOUTHERN APPANOOSE COUNTIES...

At 647 PM CDT, a severe thunderstorm was located near Centerville,
moving east at 50 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Centerville, Moulton, Cincinnati, Exline, Numa, Udell, Lake Wapello
State Park, Sharon Bluffs State Park and Centerville Municipal
Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4073 9310 4083 9251 4060 9249 4058 9310
TIME...MOT...LOC 2347Z 252DEG 42KT 4066 9285 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Donavon
323 
WWUS53 KDMX 210001
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
701 PM CDT Mon Sep 20 2021

IAC007-051-210015-
/O.CON.KDMX.SV.W.0119.000000T0000Z-210921T0015Z/
Davis IA-Appanoose IA-
701 PM CDT Mon Sep 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM CDT
FOR SOUTHWESTERN DAVIS AND SOUTHEASTERN APPANOOSE COUNTIES...

At 700 PM CDT, a severe thunderstorm was located 9 miles east of
Centerville, moving east at 35 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Centerville, Moulton, Cincinnati, Exline, Udell, Lake Wapello State
Park, Sharon Bluffs State Park and Centerville Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4083 9251 4060 9249 4059 9288 4075 9299
TIME...MOT...LOC 0000Z 252DEG 31KT 4070 9270 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Donavon

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 20, 3:38 PM CDTSevere Thunderstorm WarningDMXClarke, Madison, Union, Warren52 min
Sep 20, 4:23 PM CDTSevere Thunderstorm WarningDMXClarke, Lucas, Marion, Warren52 min
Sep 20, 4:57 PM CDTSevere Thunderstorm WarningDMXLucas, Marion, Monroe, Warren48 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.