Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 113, NWS Quad Cities, IA

December 15, 20214 counties in Iowa; Clark County, Missouri

NWS Quad Cities, IA issued this severe thunderstorm warning at Dec 15, 2021, 8:18 PM CST for 4 counties in Iowa; Clark County, Missouri. It was in force for 57 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: Dec 15, 2021, 8:18 PM CST (02:18 UTC)
Expired: Dec 15, 2021, 9:15 PM CST
In force: 57 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Possible
Damage threat: Considerable
Hail: 0.75 in
Wind: 70.0 mph

Counties Henry County, IA, Jefferson County, IA, Lee County, IA, Van Buren County, IA, Clark County, MO

The radar

The Quad Cities radar (KDVN), 137 km from the middle of the area, began a volume at 02:20 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
Dec 15, 8:55 PM CST	TSTM WND GST 60	Mount Pleasant Municipa, IA
Dec 15, 9:06 PM CST	TSTM WND GST 58	Keokuk Airport, IA
Dec 15, 9:10 PM CST	TSTM WND GST 60	Keokuk, IA

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
Dec 15, 5:30 PM CST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.3 hours before the alert went out and 142 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: 229 J/kg
Mixed-layer CIN: -358 J/kg
Mixed-layer LCL: 1061 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 433 m²/s²
0-3 km storm-relative helicity: 496 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

004 
WUUS53 KDVN 160218
SVRDVN
IAC087-101-111-177-MOC045-160315-
/O.NEW.KDVN.SV.W.0113.211216T0218Z-211216T0315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
818 PM CST Wed Dec 15 2021

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Henry County in southeastern Iowa...
  Eastern Van Buren County in southeastern Iowa...
  Eastern Jefferson County in southeastern Iowa...
  Lee County in southeastern Iowa...
  Clark County in northeastern Missouri...

* Until 915 PM CST.

* At 817 PM CST, severe thunderstorms were located along a line
  extending from near Richland to Granger, moving east at 55 mph.

  HAZARD...70 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Fort Madison, Keokuk, Fairfield, Mount Pleasant, Kahoka, Nauvoo,
  Hamilton, New London, Warsaw, Winfield, West Point, Donnellson,
  Montrose, Wayland, Birmingham, Bonaparte, Salem, Stockport,
  Lockridge and Olds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM CST for west central
Illinois...southeastern Iowa...and northeastern Missouri.

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

A Tornado Watch remains in effect until 1100 PM CST for west central
Illinois...southeastern Iowa...and northeastern Missouri.

&&

LAT...LON 4026 9195 4116 9194 4116 9137 4081 9138
      4081 9141 4080 9138 4057 9138 4055 9141
      4052 9138 4039 9138 4035 9146 4025 9150
TIME...MOT...LOC 0217Z 279DEG 46KT 4117 9194 4049 9197 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

McClure

1 follow-up statement

992 
WWUS53 KDVN 160233
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
833 PM CST Wed Dec 15 2021

IAC087-101-111-177-MOC045-160315-
/O.CON.KDVN.SV.W.0113.000000T0000Z-211216T0315Z/
Henry IA-Van Buren IA-Jefferson IA-Lee IA-Clark MO-
833 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CST
FOR HENRY...EASTERN VAN BUREN...EASTERN JEFFERSON...LEE AND CLARK
COUNTIES...

At 832 PM CST, severe thunderstorms were located along a line
extending from Coppock to near Kahoka, moving east at 55 mph.

HAZARD...70 mph wind gusts.

SOURCE...Trained weather spotters. A 65 mph wind was measured in 
         Atkins at 832 pm. 

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Fort Madison, Keokuk, Fairfield, Mount Pleasant, Kahoka, Nauvoo,
Hamilton, New London, Warsaw, Winfield, West Point, Donnellson,
Montrose, Wayland, Birmingham, Bonaparte, Salem, Stockport, Lockridge
and Olds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM CST for west central
Illinois...southeastern Iowa...and northeastern Missouri.

&&

LAT...LON 4026 9195 4116 9194 4116 9137 4081 9138
      4081 9141 4080 9138 4057 9138 4055 9141
      4052 9138 4039 9138 4035 9146 4025 9150
TIME...MOT...LOC 0232Z 270DEG 46KT 4114 9170 4046 9174 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

McClure

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 15, 7:17 PM CST	Severe Thunderstorm Warning Destructive damage threat	DVN	Benton, Iowa	58 min
Dec 15, 7:31 PM CST	Severe Thunderstorm Warning Considerable damage threat	DVN	Jefferson, Keokuk, Van Buren	59 min
Dec 15, 7:33 PM CST	Severe Thunderstorm Warning Considerable damage threat	DVN	Buchanan	57 min
Dec 15, 8:06 PM CST	Tornado Warning	DVN	Benton, Buchanan	20 min
Dec 15, 8:08 PM CST	Severe Thunderstorm Warning Considerable damage threat	DVN	Buchanan, Delaware, Johnson, Linn, Louisa, Washington	67 min
Dec 15, 8:23 PM CST	Severe Thunderstorm Warning Considerable damage threat	DVN	Benton, Iowa	37 min
Dec 15, 8:34 PM CST	Severe Thunderstorm Warning Considerable damage threat	DVN	Jefferson, Keokuk, Van Buren	26 min
Dec 15, 8:44 PM CST	Severe Thunderstorm Warning Considerable damage threat	DVN	Delaware, Dubuque, Jones	61 min
Dec 15, 8:50 PM CST	Severe Thunderstorm Warning Considerable damage threat	DVN	Cedar, Louisa, Muscatine	55 min
Dec 15, 8:53 PM CST	Severe Thunderstorm Warning Considerable damage threat	DVN	Des Moines, Lee	67 min
Dec 15, 9:12 PM CST	Severe Thunderstorm Warning Considerable damage threat	DVN	Clinton, Dubuque, Jackson, Scott	63 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021 Severe Thunderstorm Warnings in Missouri, 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.