Alert archive / Iowa / Severe Thunderstorm Warnings in 2010

Severe Thunderstorm Warning 34, NWS Des Moines, IA

April 6, 2010Jasper County, Poweshiek County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Apr 6, 2010, 6:57 PM CDT for Jasper County, Poweshiek County, Iowa. It was in force for 48 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: Apr 6, 2010, 6:57 PM CDT (23:57 UTC)
Expired: Apr 6, 2010, 7:45 PM CDT
In force: 48 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 0.5 in
Wind: 70.0 mph

Counties Jasper County, IA, Poweshiek County, IA

The radar

The Des Moines radar (KDMX), 77 km from the middle of the area, began a volume at 23:57 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 6, 2:57 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 12.0 hours before the alert went out and 191 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: 672 J/kg
Mixed-layer CIN: -116 J/kg
Mixed-layer LCL: 554 m above ground
0-6 km bulk shear: 73 kt
0-1 km storm-relative helicity: 401 m²/s²
0-3 km storm-relative helicity: 373 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 19.2

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 Apr 6, 6:55 PM CDT, 2 minutes earlier.

Area forecast discussion, Apr 6, 6:55 PM CDT, 2 minutes before

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Hazardous weather outlook, Apr 6, 2:31 PM CDT, 4 hours 26 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
231 PM CDT TUE APR 6 2010

IAZ026>028-036>039-046>050-057>062-070>075-081>086-092>097-071945-
FRANKLIN-BUTLER-BREMER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-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-
231 PM CDT TUE APR 6 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SEVERE STORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND INTO THE
EARLY EVENING HOURS. THE THREAT FOR DISCRETE TORNADIC SUPERCELLS
CONTINUES TO INCREASE ACROSS THE AREA. THE GREATEST THREAT FOR A
FEW STRONG TORNADOES EXIST ESPECIALLY ALONG THE HIGHWAY 30 AND
INTERSTATE 80 CORRIDORS EAST OF A JEFFERSON TO STUART LINE. THIS
COULD BECOME A PARTICULARLY DANGEROUS SITUATION.

THESE STORMS WILL ALSO BE CAPABLE OF VERY LARGE HAIL TO THE SIZE
OF BASEBALLS AND STRAIGHT LINE WIND GUSTS UP TO 80 MPH. LOCALIZED
VERY HEAVY RAIN IS ALSO POSSIBLE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

ISOLATED NON-SEVERE THUNDERSTORMS ARE POSSIBLE EAST OF INTERSTATE
35 ON WEDNESDAY. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED ON
MONDAY. AT THIS TIME IT IS TOO EARLY TO DETERMINE SEVERITY OF
THESE STORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY BETWEEN 4 PM AND 10 PM THIS AFTERNOON
AND EVENING.

IAZ004>007-015>017-023>025-033>035-044-045-071945-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-SAC-CALHOUN-WEBSTER-CRAWFORD-CARROLL-
231 PM CDT TUE APR 6 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS ARE POSSIBLE THROUGH TONIGHT...SOME MAY
BECOME SEVERE AT TIMES. THE MAIN THREAT LOOKS TO BE HAIL UP TO THE
SIZE OF QUARTERS WITH WIND GUSTS UP TO 60 MPH AT TIMES.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

ISOLATED NON-SEVERE THUNDERSTORMS ARE POSSIBLE EAST OF INTERSTATE
35 ON WEDNESDAY. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED ON
MONDAY. AT THIS TIME IT IS TOO EARLY TO DETERMINE SEVERITY OF
THESE STORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE THROUGH THIS EVENING.

In the hours before

Local storm report, Apr 6, 6:29 PM CDT, 28 minutes before

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Local storm report, Apr 6, 6:30 PM CDT, 27 minutes before

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Local storm report, Apr 6, 6:35 PM CDT, 22 minutes before

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Local storm report, Apr 6, 6:46 PM CDT, 11 minutes before

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Local storm report, Apr 6, 6:56 PM CDT, 1 minute before

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Local storm report, Apr 6, 6:57 PM CDT, 0 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 5, 11:39 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Cass, Guthrie	35 min
Apr 6, 12:06 AM CDT	Severe Thunderstorm Warning	DMX	Audubon, Carroll	39 min
Apr 6, 12:09 AM CDT	Severe Thunderstorm Warning	DMX	Audubon, Cass	36 min
Apr 6, 12:33 AM CDT	Severe Thunderstorm Warning	DMX	Guthrie	42 min
Apr 6, 1:03 AM CDT	Severe Thunderstorm Warning	DMX	Crawford	42 min
Apr 6, 1:25 AM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas	50 min
Apr 6, 5:12 AM CDT	Areal Flood Advisory	DMX	Black Hawk, Grundy	108 min
Apr 6, 4:35 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Bremer, Grundy	40 min
Apr 6, 5:03 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Lucas, Mahaska, Marion, Warren	42 min
Apr 6, 5:11 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Bremer	34 min
Apr 6, 5:44 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Mahaska, Poweshiek, Tama	46 min
Apr 6, 5:57 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Poweshiek, Tama	48 min
Apr 6, 6:01 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marion	26 min
Apr 6, 6:06 PM CDT	Severe Thunderstorm Warning	DMX	Warren	39 min
Apr 6, 6:08 PM CDT	Tornado Warning	DMX	Poweshiek, Tama	37 min
Apr 6, 6:13 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Warren	32 min
Apr 6, 6:29 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marion, Marshall, Polk, Poweshiek	46 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2010 Every severe thunderstorm warning in 2010

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.