Alert archive / Iowa / Special Weather Statements in 2021

Special Weather Statement, NWS La Crosse, WI

April 4, 2021Clayton County, Iowa

NWS La Crosse, WI issued this special weather statement at Apr 4, 2021, 10:40 PM CDT for Clayton County, Iowa. It was in force for 35 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
Apr 4, 2021, 10:40 PM CDT (03:40 UTC)
Expired
Apr 4, 2021, 11:15 PM CDT
In force
35 min
Issued by
NWS La Crosse, WI

County Clayton County, IA

The radar

The La Crosse radar (KARX), 109 km from the middle of the area, began a volume at 03:42 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, 3.7 hours before the alert went out and 144 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 2021-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2635 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
168 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

406 
WWUS83 KARX 050340
SPSARX

Special Weather Statement
National Weather Service La Crosse WI
1040 PM CDT Sun Apr 4 2021

IAZ030-WIZ061-050415-
Clayton-Grant-
1040 PM CDT Sun Apr 4 2021

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL CLAYTON AND WEST CENTRAL
GRANT COUNTIES...

At 1039 PM CDT, a strong thunderstorm was located near Guttenberg,
moving east at 15 mph.

Half inch hail is possible with this storm.

Locations impacted include...
Guttenberg, Bloomington, Glen Haven, Bagley, Clayton, North Andover
and Jellystone Park Near Bagley.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4281 9116 4293 9115 4293 9087 4275 9091
TIME...MOT...LOC 0339Z 280DEG 14KT 4287 9110 

$$

Kurz

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 4, 7:38 PM CDTSpecial Weather StatementARXCrawford52 min
Apr 4, 8:28 PM CDTSpecial Weather StatementARXCrawford47 min
Apr 4, 9:19 PM CDTSpecial Weather StatementARXGrant41 min
Apr 4, 9:41 PM CDTSpecial Weather StatementARXClayton49 min
Apr 5, 5:58 AM CDTSpecial Weather StatementARXChickasaw, Fayette, Floyd62 min

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.