Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 107, NWS Quad Cities, IA

September 20, 2021Delaware County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Sep 20, 2021, 6:52 PM CDT for Delaware County, Iowa. It was in force for 38 min. 1 report 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
Sep 20, 2021, 6:52 PM CDT (23:52 UTC)
Expired
Sep 20, 2021, 7:30 PM CDT
In force
38 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Delaware County, IA

The radar

The Quad Cities radar (KDVN), 118 km from the middle of the area, began a volume at 23:51 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

TimeReportWhereRemark
Sep 20, 7:10 PM CDTHAIL 0.7Manchester, IANO HAIL NOTED.

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.

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

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.9 hours before the alert went out and 121 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.

448 
WUUS53 KDVN 202352
SVRDVN
IAC055-210030-
/O.NEW.KDVN.SV.W.0107.210920T2352Z-210921T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
652 PM CDT Mon Sep 20 2021

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Western Delaware County in northeastern Iowa...

* Until 730 PM CDT.

* At 652 PM CDT, a severe thunderstorm was located near Masonville,
  or near Manchester, moving northeast at 45 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.

* This severe thunderstorm will be near...
  Manchester and Dundee around 700 PM CDT.
  Delhi, Delaware and Oneida around 705 PM CDT.
  Edgewood, Earlville and Greeley around 710 PM CDT.

Other locations in the path of this severe thunderstorm include
Colesburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in the Quad Cities.

&&

LAT...LON 4235 9136 4240 9160 4264 9160 4265 9113
TIME...MOT...LOC 2352Z 235DEG 41KT 4244 9154 

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

$$

McClure
3 follow-up statements
300 
WWUS53 KDVN 202359
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
659 PM CDT Mon Sep 20 2021

IAC055-210030-
/O.CON.KDVN.SV.W.0107.000000T0000Z-210921T0030Z/
Delaware IA-
659 PM CDT Mon Sep 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM CDT
FOR WESTERN DELAWARE COUNTY...

At 658 PM CDT, a severe thunderstorm was located over Manchester,
moving northeast at 45 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.

This severe storm will be near...
  Oneida around 705 PM CDT.
  Edgewood, Earlville and Greeley around 710 PM CDT.
  Colesburg around 720 PM CDT.

Other locations impacted by this severe thunderstorm include Coffins
Grove Park, Twin Bridges Park, Baileys Ford Park, Petersburg,
Backbone State Park, Delaware County Fairgrounds, Manchester Airport,
Oneida and Turtle Creek Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
the Quad Cities.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4235 9136 4240 9160 4264 9160 4265 9113
TIME...MOT...LOC 2358Z 235DEG 41KT 4248 9146 

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

$$

McClure
389 
WWUS53 KDVN 210014
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
714 PM CDT Mon Sep 20 2021

IAC055-210030-
/O.CON.KDVN.SV.W.0107.000000T0000Z-210921T0030Z/
Delaware IA-
714 PM CDT Mon Sep 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM CDT
FOR DELAWARE COUNTY...

At 714 PM CDT, a severe thunderstorm was located near Greeley, or 12
miles northeast of Manchester, moving northeast at 45 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 remain over mainly rural areas of
Delaware County, including the following locations... Coffins Grove
Park, Twin Bridges Park, Baileys Ford Park, Petersburg, Backbone
State Park, Delaware County Fairgrounds, Manchester Airport, Oneida
and Turtle Creek Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
the Quad Cities.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4235 9136 4242 9160 4264 9160 4265 9113
TIME...MOT...LOC 0014Z 235DEG 41KT 4259 9126 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

McClure
430 
WWUS53 KDVN 210020
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
720 PM CDT Mon Sep 20 2021

IAC055-210030-
/O.EXP.KDVN.SV.W.0107.000000T0000Z-210921T0030Z/
Delaware IA-
720 PM CDT Mon Sep 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR DELAWARE COUNTY WILL EXPIRE AT
730 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However small hail
and gusty winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
northeastern Iowa.

LAT...LON 4235 9136 4242 9160 4264 9160 4265 9113
TIME...MOT...LOC 0020Z 235DEG 41KT 4262 9120 

$$

McClure

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 20, 5:50 PM CDTSpecial Weather StatementDVNKeokuk25 min
Sep 20, 6:16 PM CDTSpecial Weather StatementDVNWashington29 min
Sep 20, 6:26 PM CDTSpecial Weather StatementDVNBuchanan34 min
Sep 20, 6:28 PM CDTSpecial Weather StatementDVNBenton, Linn32 min
Sep 20, 6:34 PM CDTSpecial Weather StatementDVNKeokuk26 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.