Alert archive / Iowa / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 214, NWS Omaha, NE

August 6, 2007Pottawattamie County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Aug 6, 2007, 6:47 PM CDT for Pottawattamie County, Iowa. It was in force for 43 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: Aug 6, 2007, 6:47 PM CDT (23:47 UTC)
Expired: Aug 6, 2007, 7:30 PM CDT
In force: 43 min
Issued by: NWS Omaha, NE
Area: Counties, with a storm outline in the text

County Pottawattamie County, IA

The radar

The Omaha radar (KOAX), 69 km from the middle of the area, began a volume at 23:50 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, 11.8 hours before the alert went out and 421 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: 2191 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 738 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 45 m²/s²
0-3 km storm-relative helicity: 17 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 2.6

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 Omaha, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 6, 3:45 PM CDT, 3 hours 2 minutes earlier.

Area forecast discussion, Aug 6, 3:45 PM CDT, 3 hours 2 minutes before

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Hazardous weather outlook, Aug 6, 5:02 PM CDT, 1 hour 45 minutes before

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In the hours before

Local storm report, Aug 6, 1:12 PM CDT, 5 hours 35 minutes before

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Local storm report, Aug 6, 2:09 PM CDT, 4 hours 38 minutes before

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Local storm report, Aug 6, 3:50 PM CDT, 2 hours 57 minutes before

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Local storm report, Aug 6, 3:57 PM CDT, 2 hours 50 minutes before

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The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 6, 5:26 AM CDT	Dense Fog Advisory	OAX	Antelope, Boone, Burt, Butler, Cass, Cedar and 16 more	4 hr
Aug 6, 10:37 AM CDT	Severe Thunderstorm Warning	OAX	Boone	38 min
Aug 6, 10:46 AM CDT	Severe Thunderstorm Warning	OAX	Platte	59 min
Aug 6, 11:22 AM CDT	Severe Thunderstorm Warning	OAX	Butler	38 min
Aug 6, 11:59 AM CDT	Severe Thunderstorm Warning	OAX	Saunders	31 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2007 Every severe thunderstorm warning in 2007

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.