Alert archive / Iowa / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 172, NWS Des Moines, IA

July 2, 2013Mahaska County, Marion County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 2, 2013, 2:06 PM CDT for Mahaska County, Marion County, Iowa. It was in force for 54 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 2, 2013, 2:06 PM CDT (19:06 UTC)
Expired: Jul 2, 2013, 3:00 PM CDT
In force: 54 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Mahaska County, IA, Marion County, IA

The radar

The Des Moines radar (KDMX), 84 km from the middle of the area, began a volume at 19:11 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 12:00Z, 7.1 hours before the alert went out and 200 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1698 m above ground
0-6 km bulk shear: 3 kt
0-1 km storm-relative helicity: 6 m²/s²
0-3 km storm-relative helicity: -3 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 2, 12:45 PM CDT, 1 hour 21 minutes earlier.

Area forecast discussion, Jul 2, 12:45 PM CDT, 1 hour 21 minutes before

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Hazardous weather outlook, Jul 2, 4:54 AM CDT, 9 hours 12 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
454 AM CDT TUE JUL 2 2013

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-031000-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-
WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-CRAWFORD-CARROLL-GREENE-
BOONE-STORY-MARSHALL-TAMA-AUDUBON-GUTHRIE-DALLAS-POLK-JASPER-
POWESHIEK-CASS-ADAIR-MADISON-WARREN-MARION-MAHASKA-ADAMS-UNION-
CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE-
DAVIS-
454 AM CDT TUE JUL 2 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TODAY AND TONIGHT

ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLY MAINLY THIS
AFTERNOON INTO THE EVENING HOURS. THE OVERALL SEVERE WEATHER
THREAT IS LOW...HOWEVER CONDITIONS WILL BE PRESENT FOR AN ISOLATED
FUNNEL CLOUD REPORT ESPECIALLY ALONG AND EAST OF INTERSTATE 35.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THERE ARE ADDITIONAL CHANCES FOR THUNDERSTORMS ACROSS PORTIONS OF
THE AREA WEDNESDAY INTO THURSDAY AND AGAIN SATURDAY NIGHT INTO
MONDAY. THE SEVERE WEATHER THREAT IS LOW WEDNESDAY INTO
THURSDAY...BUT IS MORE LIKELY WITH THE ACTIVITY SATURDAY NIGHT
THROUGH MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

MJB

In the hours before

Special weather statement, Jul 2, 1:16 PM CDT, 50 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
116 PM CDT TUE JUL 2 2013

IAZ035>038-047>049-022030-
WEBSTER-HAMILTON-HARDIN-GRUNDY-BOONE-STORY-MARSHALL-
INCLUDING THE CITIES OF...FORT DODGE...WEBSTER CITY...ELDORA...
GRUNDY CENTER...BOONE...AMES...MARSHALLTOWN
116 PM CDT TUE JUL 2 2013

...THUNDERSTORMS WITH SMALL HAIL AND GUSTY WIND MOVING ACROSS THE
AREA...

ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP AND MOVE SOUTH
BETWEEN THE HIGHWAY 20 AND HIGHWAY 30 CORRIDORS THIS AFTERNOON.
THE STORMS MAY PRODUCE SOME SMALL HAIL...TO THE SIZE OF DIMES...
AND GUSTY WINDS TO 30 MPH. THERE IS ALSO SOME POTENTIAL FOR FUNNEL
CLOUDS TO DEVELOP...MAINLY IN THE BEGINNING STAGES OF THUNDERSTORM
DEVELOPMENT.

FAB

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 2, 3:54 PM CDT	Severe Thunderstorm Warning	DMX	Polk	21 min
Jul 2, 4:24 PM CDT	Severe Thunderstorm Warning	DMX	Wayne	36 min
Jul 2, 5:27 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Warren	33 min
Jul 2, 5:43 PM CDT	Severe Thunderstorm Warning	DMX	Madison, Union	32 min
Jul 2, 6:25 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur	35 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2013 Every severe thunderstorm warning in 2013

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.