Alert archive / Iowa / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 689

September 18, 200239 counties in Iowa; 31 counties in Kansas; 35 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Sep 18, 2002, 9:25 PM CDT for 39 counties in Iowa; 31 counties in Kansas; 35 counties in Missouri. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Sep 18, 2002, 9:25 PM CDT (02:25 UTC)
Expired
Sep 19, 2002, 2:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 105 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Buchanan County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Delaware County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Linn County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Allen County, KS, Anderson County, KS, Atchison County, KS, Bourbon County, KS, Brown County, KS, Butler County, KS, Chautauqua County, KS, Cherokee County, KS, Coffey County, KS, Cowley County, KS, Crawford County, KS, Doniphan County, KS, Douglas County, KS, Elk County, KS, Franklin County, KS, Greenwood County, KS, Jackson County, KS, Jefferson County, KS, Johnson County, KS, Labette County, KS, Leavenworth County, KS, Linn County, KS, Lyon County, KS, Miami County, KS, Montgomery County, KS, Neosho County, KS, Osage County, KS, Shawnee County, KS, Wilson County, KS, Woodson County, KS, Wyandotte County, KS, Adair County, MO, Andrew County, MO, Barton County, MO, Bates County, MO, Buchanan County, MO, Caldwell County, MO, Carroll County, MO, Cass County, MO, Chariton County, MO, Clay County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Henry County, MO, Holt County, MO, Jackson County, MO, Jasper County, MO, Johnson County, MO, Lafayette County, MO, Linn County, MO, Livingston County, MO, Mercer County, MO, Nodaway County, MO, Platte County, MO, Putnam County, MO, Ray County, MO, Saline County, MO, Schuyler County, MO, St. Clair County, MO, Sullivan County, MO, Vernon County, MO, Worth County, MO

The radar

The Pleasant Hill radar (KEAX), 67 km from the middle of the area, began a volume at 02:24 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
Sep 18, 9:47 PM CDTSevere Thunderstorm WarningDMXMahaska, Marion58 min
Sep 18, 10:27 PM CDTSevere Thunderstorm WarningDMXPolk33 min
Sep 18, 11:51 PM CDTSevere Thunderstorm WarningDMXPoweshiek39 min

The nearest sounding before it

Topeka, KS (KTOP), launched 00:00Z, 2.4 hours before the alert went out and 83 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, Topeka, KS at 00:00Z on 2002-09-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5560 joules per kilogram.LCLEL10008507005003002001001 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, Topeka, KS at 00:00Z on 2002-09-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 117 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
5560 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
1271 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
117 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
2.1
Supercell composite
14.9

Open this sounding in Storm Lab

Nearby

Severe Thunderstorm Watches in Iowa, 2002Severe Thunderstorm Watches in Missouri, 2002Severe Thunderstorm Watches in Kansas, 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.