Alert archive / Iowa / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 664

September 1, 200220 counties in Iowa; 17 counties in Minnesota; 11 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Sep 1, 2002, 5:20 PM CDT for 20 counties in Iowa; 17 counties in Minnesota; 11 counties in Wisconsin. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Sep 1, 2002, 5:20 PM CDT (22:20 UTC)
Expired
Sep 1, 2002, 11:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 48 counties

Allamakee County, IA, Bremer County, IA, Butler County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Emmet County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Hancock County, IA, Howard County, IA, Humboldt County, IA, Kossuth County, IA, Mitchell County, IA, Palo Alto County, IA, Pocahontas County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Blue Earth County, MN, Brown County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Houston County, MN, Martin County, MN, Mower County, MN, Olmsted County, MN, Rice County, MN, Steele County, MN, Wabasha County, MN, Waseca County, MN, Watonwan County, MN, Winona County, MN, Buffalo County, WI, Crawford County, WI, Iowa County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Monroe County, WI, Richland County, WI, Trempealeau County, WI, Vernon County, WI, Wood County, WI

The radar

The La Crosse radar (KARX), 134 km from the middle of the area, began a volume at 22:20 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

Minneapolis, MN (KMPX), launched 12:00Z, 10.3 hours before the alert went out and 136 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 12:00Z on 2002-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 319 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 12:00Z on 2002-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 208 square meters per square second.193958Sfc1 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
319 J/kg
Mixed-layer CIN
-200 J/kg
Mixed-layer LCL
1215 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
208 m²/s²
0-3 km storm-relative helicity
219 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 1, 3:45 PM CDTSevere Thunderstorm WatchSPCBuena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more5 hr
Aug 31, 7:00 PM CDTSevere Thunderstorm WatchSPCKittson, Marshall, Pennington, Polk, Red Lake, Roseau5 hr
Aug 31, 9:55 PM CDTSevere Thunderstorm WatchSPCClay, Clearwater, Kittson, Lake of the Woods, Mahnomen, Marshall and 6 more6 hr
Sep 1, 12:45 PM CDTSevere Thunderstorm WatchSPCAnoka, Benton, Carver, Chisago, Dakota, Hennepin and 17 more6 hr
Sep 1, 6:15 PM CDTSevere Thunderstorm WatchSPCPine, Washington6 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2002Severe Thunderstorm Watches in Minnesota, 2002Severe Thunderstorm Watches in Wisconsin, 2002Every severe thunderstorm watch in 2002

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.