Alert archive / Iowa / Severe Thunderstorm Watches in 2001

Severe Thunderstorm Watch 499

July 2, 200131 counties in Iowa; Burt County, Dakota County, Thurston County, Nebraska; Clay County, Union County, South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jul 2, 2001, 10:45 PM CDT for 31 counties in Iowa; Burt County, Dakota County, Thurston County, Nebraska; Clay County, Union County, South Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jul 2, 2001, 10:45 PM CDT (03:45 UTC)
Expired: Jul 3, 2001, 4:00 AM CDT
In force: 5 hr
Issued by: the Storm Prediction Center

All 36 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cherokee County, IA, Clarke County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Greene County, IA, Guthrie County, IA, Harrison County, IA, Ida County, IA, Lucas County, IA, Madison County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, O'Brien County, IA, Plymouth County, IA, Pocahontas County, IA, Pottawattamie County, IA, Sac County, IA, Shelby County, IA, Sioux County, IA, Union County, IA, Warren County, IA, Woodbury County, IA, Burt County, NE, Dakota County, NE, Thurston County, NE, Clay County, SD, Union County, SD

The radar

The Des Moines radar (KDMX), 132 km from the middle of the area, began a volume at 03:43 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

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

Issued	Product	Office	Counties	Lasted
Jul 3, 1:49 AM CDT	Severe Thunderstorm Warning	OAX	Monona	26 min
Jul 3, 3:05 AM CDT	Severe Thunderstorm Warning	FSD	Clay, Dickinson	15 min

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 3.8 hours before the alert went out and 149 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: 2777 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 1589 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 81 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 4.0

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.

Issued	Product	Office	Counties	Lasted
Jul 3, 1:00 AM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Audubon, Carroll, Cass, Crawford and 12 more	5 hr
Jul 3, 4:00 PM CDT	Tornado Watch	SPC	Adair, Adams, Appanoose, Audubon, Cass, Clarke and 32 more	6 hr
Jul 2, 8:00 PM CDT	Severe Thunderstorm Watch	SPC	Antelope, Blaine, Boone, Boyd, Brown, Butler and 32 more	5 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2001 Severe Thunderstorm Watches in Nebraska, 2001 Severe Thunderstorm Watches in South Dakota, 2001 Every 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.