Alert archive / Iowa / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 104, NWS Omaha, NE

June 12, 2017Pottawattamie County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Jun 12, 2017, 6:44 PM CDT for Pottawattamie County, Iowa. It was in force for 31 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 12, 2017, 6:44 PM CDT (23:44 UTC)
Expired: Jun 12, 2017, 7:15 PM CDT
In force: 31 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

County Pottawattamie County, IA

The radar

The Omaha radar (KOAX), 69 km from the middle of the area, began a volume at 23:44 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

Omaha, NE (KOAX), launched 12:00Z, 11.7 hours before the alert went out and 69 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: 1090 J/kg
Mixed-layer CIN: -412 J/kg
Mixed-layer LCL: 1058 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 215 m²/s²
0-3 km storm-relative helicity: 326 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.7

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 12, 3:13 PM CDT, 3 hours 31 minutes earlier.

Area forecast discussion, Jun 12, 3:13 PM CDT, 3 hours 31 minutes before

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Hazardous weather outlook, Jun 12, 3:17 PM CDT, 3 hours 27 minutes before

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In the hours before

Special weather statement, Jun 12, 2:33 PM CDT, 4 hours 11 minutes before

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Special weather statement, Jun 12, 5:31 PM CDT, 1 hour 13 minutes before

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Special weather statement, Jun 12, 5:41 PM CDT, 1 hour 3 minutes before

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Special weather statement, Jun 12, 5:45 PM CDT, 59 minutes before

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Special weather statement, Jun 12, 5:55 PM CDT, 49 minutes before

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Special weather statement, Jun 12, 6:22 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 12, 4:59 AM CDT	Special Weather Statement	OAX	Lancaster	46 min
Jun 12, 5:16 AM CDT	Severe Thunderstorm Warning	OAX	Lancaster, Seward	29 min
Jun 12, 5:42 AM CDT	Severe Thunderstorm Warning	OAX	Lancaster, Seward	33 min
Jun 12, 6:11 AM CDT	Severe Thunderstorm Warning	OAX	Lancaster	34 min
Jun 12, 6:41 AM CDT	Severe Thunderstorm Warning	OAX	Lancaster	34 min
Jun 12, 7:11 AM CDT	Severe Thunderstorm Warning	OAX	Lancaster	34 min
Jun 12, 7:30 AM CDT	Special Weather Statement	OAX	Dodge	45 min
Jun 12, 7:34 AM CDT	Flash Flood Warning	OAX	Lancaster	3 hr
Jun 12, 7:44 AM CDT	Severe Thunderstorm Warning	OAX	Lancaster	31 min
Jun 12, 8:16 AM CDT	Special Weather Statement	OAX	Lancaster	44 min
Jun 12, 8:25 AM CDT	Special Weather Statement	OAX	Cass, Otoe, Sarpy	50 min
Jun 12, 8:36 AM CDT	Special Weather Statement	OAX	Lancaster	39 min
Jun 12, 8:43 AM CDT	Severe Thunderstorm Warning	OAX	Cass, Otoe, Sarpy	47 min
Jun 12, 8:49 AM CDT	Special Weather Statement	OAX	Butler	41 min
Jun 12, 8:56 AM CDT	Severe Thunderstorm Warning	OAX	Butler, Seward	49 min
Jun 12, 9:30 AM CDT	Special Weather Statement	OAX	Platte	45 min
Jun 12, 11:49 AM CDT	Special Weather Statement	OAX	Douglas, Sarpy	41 min
Jun 12, 12:21 PM CDT	Special Weather Statement	OAX	Gage, Pawnee	39 min
Jun 12, 1:12 PM CDT	Special Weather Statement	OAX	Cass, Johnson, Nemaha, Otoe	63 min
Jun 12, 2:33 PM CDT	Special Weather Statement	OAX	Montgomery	27 min
Jun 12, 5:31 PM CDT	Special Weather Statement	OAX	Harrison	44 min
Jun 12, 5:41 PM CDT	Special Weather Statement	OAX	Montgomery	49 min
Jun 12, 5:45 PM CDT	Special Weather Statement	OAX	Pottawattamie	45 min
Jun 12, 5:55 PM CDT	Special Weather Statement	OAX	Pottawattamie	50 min
Jun 12, 6:22 PM CDT	Special Weather Statement	OAX	Pottawattamie	53 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2017 Every severe thunderstorm warning in 2017

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.