Alert archive / Iowa / Special Weather Statements in 2021

Special Weather Statement, NWS Quad Cities, IA

August 9, 2021Dubuque County, Iowa

NWS Quad Cities, IA issued this special weather statement at Aug 9, 2021, 5:37 AM CDT for Dubuque County, Iowa. It was in force for 38 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: Aug 9, 2021, 5:37 AM CDT (10:37 UTC)
Expired: Aug 9, 2021, 6:15 AM CDT
In force: 38 min
Issued by: NWS Quad Cities, IA
Hail: 0.25 in
Wind: 40

County Dubuque County, IA

The radar

The Quad Cities radar (KDVN), 96 km from the middle of the area, began a volume at 10:41 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 nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 10.6 hours before the alert went out and 96 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: 1341 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 999 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 92 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.7

Open this sounding in Storm Lab

The text

As transmitted.

984 
WWUS83 KDVN 091037
SPSDVN

Special Weather Statement
National Weather Service Quad Cities IA/IL
537 AM CDT Mon Aug 9 2021
 
IAZ042-054-ILZ001-091115-
Jo Daviess IL-Jackson IA-Dubuque IA-
537 AM CDT Mon Aug 9 2021

...A strong thunderstorm will impact portions of western Jo Daviess,
northwestern Jackson and southern Dubuque Counties through 615 AM
CDT...

At 537 AM CDT, Doppler radar was tracking a strong thunderstorm over
Peosta, or 9 miles southwest of Dubuque, moving east at 35 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects. Minor damage to outdoor objects is 
         possible.

Locations impacted include...
Dubuque, Galena, Asbury, Bellevue, Cascade, Epworth, East Dubuque,
Peosta, La Motte, Menominee, St. Donatus, Centralia, Sageville,
Bernard, Zwingle, Durango, Rice, Graf, Dubuque Regional Airport and
Fillmore.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

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

&&

LAT...LON 4254 9064 4251 9064 4251 9039 4225 9036
      4231 9107 4256 9086 4256 9066
TIME...MOT...LOC 1037Z 274DEG 31KT 4241 9082 

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

$$

Sheets

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 3:55 AM CDT	Special Weather Statement	DVN	Buchanan	35 min
Aug 9, 4:31 AM CDT	Special Weather Statement	DVN	Delaware	29 min
Aug 9, 5:06 AM CDT	Special Weather Statement	DVN	Delaware	24 min
Aug 9, 4:59 AM CDT	Special Weather Statement	DVN	Stephenson	31 min
Aug 9, 7:08 AM CDT	Special Weather Statement	DVN	Stephenson	22 min
Aug 9, 7:38 AM CDT	Special Weather Statement	DVN	Stephenson	22 min
Aug 9, 5:55 PM CDT	Tornado Warning	DVN	Bureau	50 min
Aug 9, 6:50 PM CDT	Tornado Warning	DVN	Bureau	25 min

Nearby

Special Weather Statements in Iowa, 2021 Every special weather statement 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.