Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 66, NWS Quad Cities, IA

August 10, 2021Buchanan County, Delaware County, Linn County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Aug 10, 2021, 3:25 PM CDT for Buchanan County, Delaware County, Linn County, Iowa. It was in force for 50 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: Aug 10, 2021, 3:25 PM CDT (20:25 UTC)
Expired: Aug 10, 2021, 4:15 PM CDT
In force: 50 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Buchanan County, IA, Delaware County, IA, Linn County, IA

The radar

The Quad Cities radar (KDVN), 111 km from the middle of the area, began a volume at 20:24 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 10, 3:55 PM CDT	TSTM WND GST 60	3 N Hopkinton, IA	PUBLIC REPORT OF ESTIMATED 60 MPH WIND GUST. RELAYED BY COUNTY OFFICIAL.
Aug 10, 4:20 PM CDT	TSTM WND DMG	Prairieburg, IA	DELAYED REPORT. LARGE TREE DOWN ALONG WITH POWER LINES.

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
Aug 10, 2:08 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.4 hours before the alert went out and 115 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: 3755 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 819 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -37 m²/s²
0-3 km storm-relative helicity: 4 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

142 
WUUS53 KDVN 102025
SVRDVN
IAC019-055-113-102115-
/O.NEW.KDVN.SV.W.0066.210810T2025Z-210810T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
325 PM CDT Tue Aug 10 2021

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Eastern Buchanan County in northeastern Iowa...
  Delaware County in northeastern Iowa...
  Northern Linn County in east central Iowa...

* Until 415 PM CDT.

* At 324 PM CDT, severe thunderstorms were located along a line
  extending from near Garnavillo to near Delhi to near Alburnett, 
  moving east at 30 mph. A trained spotter reported a 60 mph wind 
  gust in Independence at 215 PM CDT.

  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.

* Severe thunderstorms will be near...
  Delhi and Delaware around 330 PM CDT.
  Earlville around 335 PM CDT.
  Coggon and Hopkinton around 340 PM CDT.

Other locations in the path of these severe thunderstorms include
Prairieburg and Waubeek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 4230 9113 4230 9136 4213 9136 4213 9183
      4230 9183 4230 9186 4264 9184 4265 9113
TIME...MOT...LOC 2024Z 271DEG 25KT 4283 9131 4238 9138 4218 9169 

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

$$

Gunkel

1 follow-up statement

091 
WWUS53 KDVN 102042
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
342 PM CDT Tue Aug 10 2021

IAC019-055-113-102115-
/O.CON.KDVN.SV.W.0066.000000T0000Z-210810T2115Z/
Buchanan IA-Delaware IA-Linn IA-
342 PM CDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM CDT
FOR EASTERN BUCHANAN...DELAWARE AND NORTHERN LINN COUNTIES...

At 341 PM CDT, severe thunderstorms were located along a line
extending from near Guttenberg to near Hopkinton to Central City,
moving east 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.

These severe thunderstorms will remain over mainly rural areas of
eastern Buchanan, Delaware and northern Linn Counties, including the
following locations... Winthrop Golf Course, Robinson, Delaware
County Fairgrounds, Buffalo Creek Park, Manchester Airport, Howard H
Cherry Scout Reservation, Oneida, Linn  County Fairgrounds, Monti and
Coffins Grove Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Continuous cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 4230 9113 4230 9136 4213 9136 4213 9183
      4230 9183 4230 9186 4264 9184 4265 9113
TIME...MOT...LOC 2041Z 271DEG 25KT 4283 9115 4238 9123 4218 9154 

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

$$

Gunkel

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 2:28 PM CDT	Heat Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	29 hr
Aug 10, 2:33 PM CDT	Special Weather Statement	DVN	Buchanan	27 min
Aug 10, 2:42 PM CDT	Special Weather Statement	DVN	Benton	33 min
Aug 10, 2:55 PM CDT	Severe Thunderstorm Warning	DVN	Buchanan	50 min
Aug 10, 3:07 PM CDT	Severe Thunderstorm Warning	DVN	Delaware, Dubuque	23 min
Aug 10, 3:29 PM CDT	Severe Thunderstorm Warning	DVN	Delaware, Dubuque	31 min
Aug 10, 3:49 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Buchanan, Iowa	41 min
Aug 10, 4:04 PM CDT	Severe Thunderstorm Warning	DVN	Delaware, Dubuque, Jackson, Jones, Linn	56 min
Aug 10, 4:28 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Buchanan, Delaware, Linn	36 min
Aug 10, 4:38 PM CDT	Severe Thunderstorm Warning	DVN	Cedar, Jackson, Jones, Linn	52 min
Aug 10, 5:00 PM CDT	Severe Thunderstorm Warning	DVN	Clinton, Jackson, Jones	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.