Alert archive / Iowa / Severe Thunderstorm Watches in 2001

Severe Thunderstorm Watch 603

July 21, 200127 counties in Iowa; Crawford County, Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jul 21, 2001, 1:30 PM CDT for 27 counties in Iowa; Crawford County, Wisconsin. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jul 21, 2001, 1:30 PM CDT (18:30 UTC)
Expired
Jul 21, 2001, 6:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 28 counties

Allamakee County, IA, Benton County, IA, Black Hawk County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Cedar County, IA, Chickasaw County, IA, Clayton County, IA, Delaware County, IA, Dubuque County, IA, Fayette County, IA, Floyd County, IA, Grundy County, IA, Howard County, IA, Iowa County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Mahaska County, IA, Mitchell County, IA, Muscatine County, IA, Poweshiek County, IA, Tama County, IA, Washington County, IA, Winneshiek County, IA, Crawford County, WI

The radar

The Quad Cities radar (KDVN), 136 km from the middle of the area, began a volume at 18:32 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.

Warnings issued inside it

3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jul 21, 4:13 PM CDTSevere Thunderstorm WarningDMXJasper, Poweshiek47 min
Jul 21, 5:07 PM CDTSevere Thunderstorm WarningDVNJohnson53 min
Jul 21, 5:29 PM CDTSevere Thunderstorm WarningDVNMuscatine61 min

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 6.5 hours before the alert went out and 139 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, Davenport, at 12:00Z on 2001-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 963 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2001-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 square meters per square second.1939Sfc1 km3 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
963 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
605 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 10:30 AM CDTSevere Thunderstorm WatchSPCBoone, Buena Vista, Calhoun, Carroll, Cerro Gordo, Cherokee and 23 more5 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2001Severe Thunderstorm Watches in Wisconsin, 2001Every severe thunderstorm watch in 2001

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.