Alert archive / Iowa / Special Weather Statements in 2017

Special Weather Statement, NWS Des Moines, IA

August 3, 2017Guthrie County, Iowa

NWS Des Moines, IA issued this special weather statement at Aug 3, 2017, 3:33 AM CDT for Guthrie County, Iowa. It was in force for 27 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 3, 2017, 3:33 AM CDT (08:33 UTC)
Expired
Aug 3, 2017, 4:00 AM CDT
In force
27 min
Issued by
NWS Des Moines, IA

County Guthrie County, IA

The radar

The Des Moines radar (KDMX), 85 km from the middle of the area, began a volume at 08:36 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

Omaha, NE (KOAX), launched 00:00Z, 8.6 hours before the alert went out and 140 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, Omaha, NE at 00:00Z on 2017-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1511 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, Omaha, NE at 00:00Z on 2017-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 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
1511 J/kg
Mixed-layer CIN
-43 J/kg
Mixed-layer LCL
1282 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

285 
WWUS83 KDMX 030833
SPSDMX

Special Weather Statement
National Weather Service Des Moines IA
333 AM CDT THU AUG 3 2017
 
IAZ057-058-030900-
Guthrie IA-Audubon IA-
333 AM CDT THU AUG 3 2017

...Dime sized hail possible...

At 332 AM CDT, Doppler radar was tracking a strong thunderstorm 10
miles south of Audubon, moving east at 30 mph.

Dime size hail will be possible with this storm.

Locations impacted include...
Guthrie Center, Exira and Springbrook State Park. 

LAT...LON 4151 9490 4163 9494 4182 9448 4154 9442
TIME...MOT...LOC 0832Z 254DEG 27KT 4157 9501 

$$

Ansorge

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 3, 4:49 AM CDTSpecial Weather StatementDMXAdams41 min
Aug 3, 7:12 AM CDTSpecial Weather StatementDMXClarke, Decatur, Lucas, Wayne48 min
Aug 3, 7:41 AM CDTSpecial Weather StatementDMXAppanoose, Lucas, Monroe, Wayne64 min
Aug 3, 8:24 AM CDTSpecial Weather StatementDMXDavis, Wapello66 min

Nearby

Special Weather Statements in Iowa, 2017Every special weather statement in 2017

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.