Alert archive / Iowa / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 137, NWS Omaha, NE

June 23, 2009Shelby County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Jun 23, 2009, 3:40 PM CDT for Shelby County, Iowa. It was in force for 50 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: Jun 23, 2009, 3:40 PM CDT (20:40 UTC)
Expired: Jun 23, 2009, 4:30 PM CDT
In force: 50 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon

County Shelby County, IA

The radar

The Omaha radar (KOAX), 97 km from the middle of the area, began a volume at 20:41 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
Jun 23, 3:28 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 8.7 hours before the alert went out and 97 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: 5075 J/kg
Mixed-layer CIN: -83 J/kg
Mixed-layer LCL: 959 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 55 m²/s²
0-3 km storm-relative helicity: 45 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.1

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 Omaha, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 23, 3:05 PM CDT, 35 minutes earlier.

Area forecast discussion, Jun 23, 3:05 PM CDT, 35 minutes before

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Hazardous weather outlook, Jun 23, 12:07 PM CDT, 3 hours 33 minutes before

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In the hours before

Local storm report, Jun 23, 3:18 PM CDT, 22 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
Jun 23, 1:31 PM CDT	Excessive Heat Warning	OAX	Cass, Douglas, Johnson, Nemaha, Otoe, Pawnee and 2 more	25 hr
Jun 23, 5:54 PM CDT	Severe Thunderstorm Warning	OAX	Sarpy	36 min
Jun 23, 5:57 PM CDT	Severe Thunderstorm Warning	OAX	Butler	33 min
Jun 23, 3:02 PM CDT	Severe Thunderstorm Warning	OAX	Harrison	43 min
Jun 23, 3:23 PM CDT	Severe Thunderstorm Warning	OAX	Harrison	52 min
Jun 23, 6:17 PM CDT	Severe Thunderstorm Warning	OAX	Montgomery, Page	44 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.