Alert archive / Iowa / Severe Thunderstorm Watches in 2009

Severe Thunderstorm Watch 340

June 6, 200930 counties in Iowa; 4 counties in Kansas; 26 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Jun 6, 2009, 11:16 PM CDT for 30 counties in Iowa; 4 counties in Kansas; 26 counties in Missouri. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jun 6, 2009, 11:16 PM CDT (04:16 UTC)
Expired
Jun 7, 2009, 5:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
70 kt
All 60 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Boone County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Greene County, IA, Guthrie County, IA, Jasper 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, Wayne County, IA, Atchison County, KS, Doniphan County, KS, Leavenworth County, KS, Wyandotte County, KS, Adair County, MO, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Caldwell County, MO, Carroll 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, Holt County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Mercer County, MO, Nodaway County, MO, Platte County, MO, Putnam County, MO, Ray County, MO, Schuyler County, MO, Sullivan County, MO, Worth County, MO

The radar

The Des Moines radar (KDMX), 141 km from the middle of the area, began a volume at 04:16 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
50%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
50%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 7, 12:50 AM CDTSevere Thunderstorm WarningDMXCass39 min
Jun 7, 1:12 AM CDTSevere Thunderstorm WarningDMXAdair48 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 4.3 hours before the alert went out and 195 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, Omaha, NE at 00:00Z on 2009-06-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2090 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, Omaha, NE at 00:00Z on 2009-06-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 159 square meters per square second.1939587897Sfc1 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
2090 J/kg
Mixed-layer CIN
-79 J/kg
Mixed-layer LCL
899 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
159 m²/s²
0-3 km storm-relative helicity
202 m²/s²
Significant tornado parameter
1.7
Supercell composite
9.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 6, 9:01 PM CDTSevere Thunderstorm WatchSPCFremont, Mills, Montgomery, Page6 hr
Jun 6, 11:04 PM CDTMesoscale DiscussionSPCAdams, Fremont, Mills, Montgomery, Page, Taylor86 min
Jun 7, 12:44 AM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Boone, Carroll and 36 more61 min
Jun 7, 4:45 AM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Cass, Cedar, Clarke and 31 more30 min
Jun 7, 11:16 AM CDTMesoscale DiscussionSPCBuena Vista, Calhoun, Carroll, Cerro Gordo, Cherokee, Clay and 24 more119 min
Jun 7, 2:36 PM CDTMesoscale DiscussionSPCFremont, Mills, Montgomery, Page, Taylor114 min
Jun 7, 3:45 PM CDTTornado WatchSPCAdair, Adams, Audubon, Cass, Clarke, Dallas and 12 more7 hr
Jun 7, 5:21 PM CDTMesoscale DiscussionSPCBoone, Bremer, Buena Vista, Butler, Calhoun, Carroll and 25 more54 min
Jun 7, 5:31 PM CDTMesoscale DiscussionSPCAppanoose, Davis, Henry, Iowa, Jefferson, Keokuk and 10 more59 min
Jun 7, 5:44 PM CDTTornado WatchSPCAppanoose, Boone, Davis, Jasper, Lucas, Mahaska and 10 more6 hr
Jun 7, 3:30 PM CDTMesoscale DiscussionSPCCheyenne, Sherman, Thomas, Wallace60 min
Jun 7, 4:13 PM CDTMesoscale DiscussionSPCBarber, Barton, Comanche, Edwards, Ellsworth, Harper and 10 more62 min
Jun 7, 5:07 PM CDTSevere Thunderstorm WatchSPCAllen, Anderson, Barber, Barton, Butler, Chase and 39 more7 hr
Jun 7, 5:31 PM CDTSevere Thunderstorm WatchSPCCheyenne, Decatur, Gove, Graham, Greeley, Logan and 7 more5 hr
Jun 7, 12:18 PM CDTMesoscale DiscussionSPCAudrain, Benton, Boone, Callaway, Camden, Chariton and 26 more57 min

Nearby

Severe Thunderstorm Watches in Iowa, 2009Severe Thunderstorm Watches in Missouri, 2009Severe Thunderstorm Watches in Kansas, 2009Every severe thunderstorm watch 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.