Alert archive / Iowa / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 134, NWS Des Moines, IA

July 10, 20094 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 10, 2009, 4:58 AM CDT for 4 counties in Iowa. It was in force for 47 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 10, 2009, 4:58 AM CDT (09:58 UTC)
Expired: Jul 10, 2009, 5:45 AM CDT
In force: 47 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon

Counties Black Hawk County, IA, Grundy County, IA, Marshall County, IA, Tama County, IA

The radar

The Des Moines radar (KDMX), 105 km from the middle of the area, began a volume at 10:02 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 00:00Z, 10.0 hours before the alert went out and 192 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: 11 J/kg
Mixed-layer CIN: -339 J/kg
Mixed-layer LCL: 982 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: 146 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

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 10, 3:13 AM CDT, 1 hour 45 minutes earlier.

Area forecast discussion, Jul 10, 3:13 AM CDT, 1 hour 45 minutes before

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Hazardous weather outlook, Jul 10, 4:34 AM CDT, 24 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
434 AM CDT FRI JUL 10 2009

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-111115-
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-
434 AM CDT FRI JUL 10 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS WILL CONTINUE TO DEVELOP IN EASTERN IOWA EARLY THIS
MORNING...AND SPREAD SOUTH ACROSS THE EASTERN PORTION OF THE
OUTLOOK AREA EARLY TODAY. THUNDERSTORMS AREA ALSO EXPECTED TO
DEVELOP OVER NORTHWEST IOWA AND MOVE EAST INTO NORTHERN IOWA THIS
MORNING. HEAVY RAIN AND SOME SEVERE WEATHER IS LIKELY THROUGH 10
AM THIS MORNING NORTH OF HIGHWAY 20 AND EAST OF INTERSTATE 35.

BY LATE MORNING AND EARLY AFTERNOON...ADDITIONAL THUNDERSTORMS WITH
LARGE HAIL...DAMAGING STRAIGHT LINE WINDS TO 70 MPH WILL BE POSSIBLE
OVER MUCH OF THE REGION. AN ISOLATED TORNADO IS ALSO POSSIBLE.
HEAVY RAINFALL IS ALSO POSSIBLE THIS AFTERNOON AND EVENING
...MAINLY ALONG AND SOUTH OF HIGHWAY 20. ISOLATED 3 TO 4 INCH RAINFALL
AMOUNTS COULD PRODUCE SOME FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THUNDERSTORM CHANCES RETURN TO THE FORECAST LATE SUNDAY NIGHT INTO
EARLY NEXT WEEK AND WILL REMAIN IN THE FORECAST THROUGH AT LEAST TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED AT TIMES THROUGH LATE EVENING...AND
POSSIBLY AGAIN EARLY NEXT WEEK.

REV

In the hours before

Special weather statement, Jul 9, 11:55 PM CDT, 5 hours 3 minutes before

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Special weather statement, Jul 10, 1:18 AM CDT, 3 hours 40 minutes before

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Local storm report, Jul 10, 3:50 AM CDT, 1 hour 8 minutes before

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Local storm report, Jul 10, 4:00 AM CDT, 58 minutes before

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Local storm report, Jul 10, 4:04 AM CDT, 54 minutes before

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Local storm report, Jul 10, 4:44 AM CDT, 14 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
Jul 9, 8:57 PM CDT	Severe Thunderstorm Warning	DMX	Emmet, Palo Alto	48 min
Jul 9, 9:42 PM CDT	Severe Thunderstorm Warning	DMX	Emmet, Palo Alto	48 min
Jul 9, 10:51 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth	39 min
Jul 9, 11:09 PM CDT	Flash Flood Warning	DMX	Emmet, Kossuth	6 hr
Jul 10, 12:59 AM CDT	Areal Flood Advisory	DMX	Cerro Gordo, Hancock, Kossuth, Winnebago, Worth	3 hr
Jul 10, 1:54 AM CDT	Areal Flood Advisory	DMX	Cerro Gordo, Franklin, Hancock, Wright	3 hr
Jul 10, 2:54 AM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Bremer, Butler	36 min
Jul 10, 3:27 AM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Bremer, Butler, Grundy	48 min
Jul 10, 4:28 AM CDT	Areal Flood Advisory	DMX	Black Hawk, Bremer, Butler, Franklin, Grundy, Hardin	4 hr
Jul 10, 8:02 AM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Hamilton, Webster	43 min
Jul 10, 8:10 AM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Carroll, Crawford, Greene, Sac	50 min
Jul 10, 8:29 AM CDT	Severe Thunderstorm Warning	DMX	Boone, Greene, Hamilton, Story	46 min
Jul 10, 8:45 AM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas, Greene, Guthrie	29 min
Jul 10, 9:10 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Polk, Story	50 min
Jul 10, 9:36 AM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall	39 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2009 Every severe thunderstorm warning in 2009

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.