Alert archive / Iowa / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 192, NWS Omaha, NE

August 9, 2009Monona County, Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Aug 9, 2009, 6:57 AM CDT for Monona County, Iowa. It was in force for 48 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 9, 2009, 6:57 AM CDT (11:57 UTC)
Expired
Aug 9, 2009, 7:45 AM CDT
In force
48 min
Issued by
NWS Omaha, NE
Area
Storm-based polygon

County Monona County, IA

The radar

The Omaha radar (KOAX), 88 km from the middle of the area, began a volume at 11:57 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.

IssuedProductOfficeLasted
Aug 9, 5:16 AM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 12.0 hours before the alert went out and 365 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-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2009-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3715 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2009-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 190 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
3715 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
841 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
190 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
3.8
Supercell composite
16.8

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 5:36 AM CDTSevere Thunderstorm WarningOAXButler, Colfax, Platte54 min
Aug 9, 5:44 AM CDTSevere Thunderstorm WarningOAXColfax, Cuming, Madison, Platte, Stanton, Wayne61 min
Aug 9, 6:18 AM CDTSevere Thunderstorm WarningOAXButler, Colfax, Dodge, Saunders48 min
Aug 9, 6:54 AM CDTSevere Thunderstorm WarningOAXBurt, Cuming, Dodge, Washington45 min
Aug 9, 7:33 AM CDTSevere Thunderstorm WarningOAXBurt, Washington57 min
Aug 9, 3:55 PM CDTSevere Thunderstorm WarningOAXGage, Johnson, Nemaha, Otoe65 min
Aug 9, 4:28 PM CDTSevere Thunderstorm WarningOAXJohnson, Nemaha, Otoe50 min
Aug 9, 5:41 PM CDTSevere Thunderstorm WarningOAXGage34 min
Aug 9, 5:12 PM CDTSevere Thunderstorm WarningOAXFremont, Page39 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2009Every 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.