Alert archive / Iowa / Special Weather Statements in 2021

Special Weather Statement, NWS Quad Cities, IA

August 8, 2021Benton County, Iowa

NWS Quad Cities, IA issued this special weather statement at Aug 8, 2021, 1:59 AM CDT for Benton County, Iowa. It was in force for 31 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 8, 2021, 1:59 AM CDT (06:59 UTC)
Expired
Aug 8, 2021, 2:30 AM CDT
In force
31 min
Issued by
NWS Quad Cities, IA
Hail
0.75 in
Wind
50

County Benton County, IA

The radar

The Des Moines radar (KDMX), 140 km from the middle of the area, began a volume at 06:59 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, 7.0 hours before the alert went out and 155 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 00:00Z on 2021-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2231 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2021-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 square meters per square second.193958Sfc1 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
2231 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
1094 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.1

Open this sounding in Storm Lab

The text

As transmitted.

045 
WWUS83 KDVN 080659
SPSDVN

Special Weather Statement
National Weather Service Quad Cities IA/IL
159 AM CDT Sun Aug 8 2021
 
IAZ040-051-080730-
Buchanan IA-Benton IA-
159 AM CDT Sun Aug 8 2021

...A strong thunderstorm will impact portions of southwestern
Buchanan and northwestern Benton Counties through 230 AM CDT...

At 159 AM CDT, Doppler radar was tracking a strong thunderstorm over
Dysart, or 11 miles west of Vinton, moving northeast at 15 mph.

HAZARD...Wind gusts up to 50 mph and penny 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...
Dysart, Brandon and Mount Auburn. 

This includes Interstate 380 near mile marker 51.
 
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 4230 9230 4230 9207 4234 9206 4232 9197
      4208 9222 4210 9230
TIME...MOT...LOC 0659Z 208DEG 11KT 4216 9226 

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH

$$

Sheets

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 1:29 AM CDTSpecial Weather StatementDVNBenton31 min
Aug 8, 2:32 AM CDTSpecial Weather StatementDVNBenton28 min
Aug 8, 2:24 PM CDTHeat AdvisoryDVNBenton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more53 hr

Nearby

Special Weather Statements in Iowa, 2021Every 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.