Alert archive / Iowa / Special Weather Statements in 2017

Special Weather Statement, NWS Des Moines, IA

August 1, 2017Webster County, Iowa

NWS Des Moines, IA issued this special weather statement at Aug 1, 2017, 9:13 PM CDT for Webster County, Iowa. It was in force for 32 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 1, 2017, 9:13 PM CDT (02:13 UTC)
Expired
Aug 1, 2017, 9:45 PM CDT
In force
32 min
Issued by
NWS Des Moines, IA

County Webster County, IA

The radar

The Des Moines radar (KDMX), 107 km from the middle of the area, began a volume at 02:15 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, 2.2 hours before the alert went out and 211 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 2017-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 601 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 2017-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
601 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
1685 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
66 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

992 
WWUS83 KDMX 020213
SPSDMX

Special Weather Statement
National Weather Service Des Moines IA
913 PM CDT TUE AUG 1 2017
 
IAZ024-034-035-020245-
Humboldt IA-Calhoun IA-Webster IA-
913 PM CDT TUE AUG 1 2017

...LINE OF STORMS MAY PRODUCE DIME TO NICKEL SIZE HAIL ALONG 
WITH WIND GUSTS TO 50 MPH...

At 912 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 6 miles southeast of Dakota City to near
Manson. Movement was southeast at 25 mph.

Dime size hail and wind gusts up to 50 mph will be possible with
these storms.

Locations impacted include...
Fort Dodge, Manson, Fort Dodge Regional Airport, Coalville, Badger,
Otho, Duncombe, Twin Lakes, Barnum, Thor, Vincent, Moorland, Clare,
Somers, Knierim, Woodman Hollow State Park, Frank A Gotch State Park
and Lizard Creek State Recreation Area.

LAT...LON 4255 9464 4256 9460 4256 9444 4261 9444
      4272 9406 4244 9397 4234 9453
TIME...MOT...LOC 0212Z 327DEG 21KT 4266 9411 4252 9459 

$$

Kotenberg

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 7:12 PM CDTSpecial Weather StatementDMXHumboldt33 min
Aug 1, 7:16 PM CDTSpecial Weather StatementDMXKossuth, Winnebago29 min
Aug 1, 7:45 PM CDTSpecial Weather StatementDMXCerro Gordo, Hancock, Worth45 min
Aug 1, 8:22 PM CDTSpecial Weather StatementDMXCerro Gordo, Wright38 min
Aug 1, 8:56 PM CDTSpecial Weather StatementDMXFranklin, Hamilton34 min
Aug 1, 9:21 PM CDTSpecial Weather StatementDMXHamilton, Hardin39 min
Aug 1, 9:47 PM CDTSpecial Weather StatementDMXHamilton, Webster28 min
Aug 1, 9:58 PM CDTSpecial Weather StatementDMXStory32 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.