Alert archive / Iowa / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 46, NWS Omaha, NE

April 26, 2009Montgomery County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Apr 26, 2009, 4:34 PM CDT for Montgomery County, Iowa. It was in force for 28 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 26, 2009, 4:34 PM CDT (21:34 UTC)
Expired: Apr 26, 2009, 5:02 PM CDT
In force: 28 min
Issued by: NWS Omaha, NE
Area: Storm-based polygon

County Montgomery County, IA

The radar

The Omaha radar (KOAX), 106 km from the middle of the area, began a volume at 21:35 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 26, 12:48 PM CDT	Tornado Watch	SPC	4 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 9.6 hours before the alert went out and 107 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 538 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 457 m²/s²
0-3 km storm-relative helicity: 572 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.0

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 Apr 26, 4:17 PM CDT, 17 minutes earlier.

Area forecast discussion, Apr 26, 4:17 PM CDT, 17 minutes before

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Hazardous weather outlook, Apr 26, 11:39 AM CDT, 4 hours 55 minutes before

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In the hours before

Local storm report, Apr 26, 2:15 PM CDT, 2 hours 19 minutes before

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Local storm report, Apr 26, 2:21 PM CDT, 2 hours 13 minutes before

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Local storm report, Apr 26, 2:25 PM CDT, 2 hours 9 minutes before

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Local storm report, Apr 26, 2:29 PM CDT, 2 hours 5 minutes before

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Local storm report, Apr 26, 3:10 PM CDT, 1 hour 24 minutes before

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Local storm report, Apr 26, 3:25 PM CDT, 1 hour 9 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
Apr 25, 11:58 PM CDT	Severe Thunderstorm Warning	OAX	Saline	47 min
Apr 26, 3:30 AM CDT	Flash Flood Watch	OAX	Gage, Johnson, Nemaha, Otoe, Pawnee, Richardson	14 hr
Apr 26, 8:35 AM CDT	Severe Thunderstorm Warning	OAX	Douglas, Sarpy	43 min
Apr 26, 9:21 AM CDT	Severe Thunderstorm Warning	OAX	Nemaha, Pawnee, Richardson	41 min
Apr 26, 11:10 AM CDT	Severe Thunderstorm Warning	OAX	Gage	50 min
Apr 26, 11:52 AM CDT	Severe Thunderstorm Warning	OAX	Gage, Johnson	38 min
Apr 26, 12:18 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Otoe	42 min
Apr 26, 12:48 PM CDT	Areal Flood Advisory	OAX	Cass, Gage, Johnson, Nemaha, Otoe	6 hr
Apr 26, 12:59 PM CDT	Areal Flood Advisory	OAX	Cass, Gage, Johnson, Nemaha, Otoe	6 hr
Apr 26, 1:12 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson	63 min
Apr 26, 1:52 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Johnson, Lancaster, Otoe	38 min
Apr 26, 2:17 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Otoe	58 min
Apr 26, 2:36 PM CDT	Areal Flood Advisory	OAX	Douglas, Sarpy	5 hr
Apr 26, 2:50 PM CDT	Areal Flood Advisory	OAX	Douglas, Sarpy	4 hr
Apr 26, 3:04 PM CDT	Severe Thunderstorm Warning	OAX	Butler	25 min
Apr 26, 3:45 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha, Richardson	22 min
Apr 26, 9:06 AM CDT	Severe Thunderstorm Warning	OAX	Mills, Pottawattamie	39 min
Apr 26, 1:49 PM CDT	Severe Thunderstorm Warning	OAX	Mills, Montgomery, Pottawattamie	41 min
Apr 26, 3:01 PM CDT	Severe Thunderstorm Warning	OAX	Mills, Montgomery, Pottawattamie	59 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.