Alert archive / Iowa / Special Weather Statements in 2021

Special Weather Statement, NWS La Crosse, WI

August 8, 2021Howard County, Iowa

NWS La Crosse, WI issued this special weather statement at Aug 8, 2021, 2:56 AM CDT for Howard County, Iowa. It was in force for 34 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, 2:56 AM CDT (07:56 UTC)
Expired
Aug 8, 2021, 3:30 AM CDT
In force
34 min
Issued by
NWS La Crosse, WI
Hail
0.25 in
Wind
30

County Howard County, IA

The radar

The La Crosse radar (KARX), 104 km from the middle of the area, began a volume at 07:55 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

Minneapolis, MN (KMPX), launched 00:00Z, 7.9 hours before the alert went out and 195 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, Minneapolis, MN at 00:00Z on 2021-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1238 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, Minneapolis, MN at 00:00Z on 2021-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 144 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
1238 J/kg
Mixed-layer CIN
-150 J/kg
Mixed-layer LCL
630 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
144 m²/s²
0-3 km storm-relative helicity
226 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.6

Open this sounding in Storm Lab

The text

As transmitted.

237 
WWUS83 KARX 080756
SPSARX

Special Weather Statement
National Weather Service La Crosse WI
256 AM CDT Sun Aug 8 2021
 
IAZ009-010-080830-
Winneshiek IA-Howard IA-
256 AM CDT Sun Aug 8 2021

...Strong thunderstorm will impact Howard and northwestern 
Winneshiek Counties through 330 AM CDT...

At 255 AM CDT, Doppler radar was tracking a strong thunderstorm 7
miles northeast of Elma, or 10 miles southwest of Cresco, moving
northeast at 30 mph.

HAZARD...Winds in excess of 30 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...
Cresco, Elma, Lime Springs, Ridgeway, Protivin, Chester, Lylahs Marsh
County Park, Vernon Springs County Park, Saratoga, County B 17 And
Bell Avenue, Maple Leaf, Vernon Springs, Bonair, County Roads V 58
And A 46, Hayden Prairie, Schley, County V 10 And 40th Street, Davis
Corners, County Roads W 14 And A 34 and State Road 9 And 290th
Street.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4350 9254 4350 9201 4323 9195 4321 9224
      4321 9255
TIME...MOT...LOC 0755Z 228DEG 25KT 4330 9231 

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...30 MPH

$$

Kurz

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 7:16 PM CDTAreal Flood WarningARXVernon6 hr
Aug 7, 8:59 PM CDTRiver Flood WarningARXCrawford5 days
Aug 7, 8:59 PM CDTRiver Flood WarningARXCrawford6 days
Aug 7, 8:59 PM CDTRiver Flood WarningARXCrawford6 days
Aug 7, 9:14 PM CDTRiver Flood WarningARXJackson48 hr
Aug 8, 2:27 PM CDTSpecial Weather StatementARXAdams, Jackson, Juneau, Monroe78 min
Aug 8, 3:32 PM CDTSevere Thunderstorm WarningARXAdams31 min
Aug 8, 3:41 AM CDTSpecial Weather StatementARXHoward34 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.