Alert archive / Iowa / Tornado Watches in 2008

Tornado Watch 392

May 30, 20086 counties in Illinois; 31 counties in Iowa; Clark County, Scotland County, Missouri

The Storm Prediction Center issued this tornado watch at May 30, 2008, 1:19 AM CDT for 6 counties in Illinois; 31 counties in Iowa; Clark County, Scotland County, Missouri. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
May 30, 2008, 1:19 AM CDT (06:19 UTC)
Expired
May 30, 2008, 9:00 AM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 39 counties

Appanoose County, IA, Benton County, IA, Cedar County, IA, Clarke County, IA, Clinton County, IA, Davis County, IA, Des Moines County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Mahaska County, IA, Marion County, IA, Monroe County, IA, Muscatine County, IA, Poweshiek County, IA, Scott County, IA, Tama County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Hancock County, IL, Henderson County, IL, McDonough County, IL, Mercer County, IL, Rock Island County, IL, Warren County, IL, Clark County, MO, Scotland County, MO

The radar

The Quad Cities radar (KDVN), 91 km from the middle of the area, began a volume at 06:20 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.

What SPC expected

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

Two or more tornadoes
30%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 30, 1:41 AM CDTSevere Thunderstorm WarningDMXAdair, Adams, Clarke, Dallas, Guthrie, Madison and 2 more49 min
May 30, 1:50 AM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Ringgold, Union, Warren40 min
May 30, 1:51 AM CDTFlash Flood WarningDVNBenton6 hr
May 30, 1:53 AM CDTFlash Flood WarningDMXBlack Hawk, Grundy, Hardin, Marshall, Tama6 hr
May 30, 2:41 AM CDTSevere Thunderstorm WarningDVNDelaware, Dubuque, Jackson, Jones34 min
May 30, 4:05 AM CDTTornado WarningDMXClarke, Union40 min
May 30, 4:25 AM CDTSevere Thunderstorm WarningDMXClarke, Lucas, Marion, Warren50 min
May 30, 4:40 AM CDTTornado WarningDMXClarke, Lucas, Warren19 min
May 30, 5:01 AM CDTSevere Thunderstorm WarningDMXMahaska, Marion44 min
May 30, 5:18 AM CDTTornado WarningDMXMahaska, Marion42 min
May 30, 5:37 AM CDTSevere Thunderstorm WarningDMXMahaska23 min
May 30, 6:32 AM CDTSevere Thunderstorm WarningDMXAppanoose, Wayne43 min
May 30, 7:54 AM CDTSevere Thunderstorm WarningDVNMercer36 min
May 30, 7:56 AM CDTFlash Flood WarningDVNJones7 hr
May 30, 8:14 AM CDTSevere Thunderstorm WarningDVNHenry, Mercer, Rock Island61 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

Davenport, (KDVN), launched 00:00Z, 6.3 hours before the alert went out and 98 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 00:00Z on 2008-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Davenport, at 00:00Z on 2008-05-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 381 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2119 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
381 m²/s²
0-3 km storm-relative helicity
712 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 30, 2:17 AM CDTMesoscale DiscussionSPCHancock, Henderson, McDonough, Mercer, Rock Island, Warren88 min
May 30, 6:00 AM CDTMesoscale DiscussionSPCCarroll, Hancock, Henderson, Henry, Knox, Mercer and 3 more2 hr
May 30, 7:56 AM CDTTornado WatchSPCAdams, Brown, Bureau, Cass, Cook, DuPage and 26 more6 hr
May 30, 10:13 AM CDTMesoscale DiscussionSPCCook, DuPage, Grundy, Kendall, LaSalle, Will62 min
May 30, 1:14 PM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Champaign, Christian and 24 more2 hr
May 30, 1:56 PM CDTTornado WatchSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 37 more8 hr
May 30, 4:29 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 19 more61 min
May 30, 5:18 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 37 more87 min
May 29, 7:37 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Boone, Calhoun and 25 more53 min
May 29, 8:13 PM CDTTornado WatchSPCAdair, Adams, Appanoose, Audubon, Boone, Calhoun and 29 more8 hr
May 29, 10:21 PM CDTMesoscale DiscussionSPCPlymouth, Sioux, Woodbury24 min
May 29, 11:34 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Black Hawk, Boone and 38 more56 min
May 30, 1:37 AM CDTMesoscale DiscussionSPCFremont, Harrison, Mills, Monona, Montgomery, Page and 2 more53 min
May 30, 4:58 PM CDTSevere Thunderstorm WatchSPCAllamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more3 hr
May 30, 2:23 PM CDTMesoscale DiscussionSPCBates, Caldwell, Carroll, Cass, Chariton, Clay and 15 more97 min
May 30, 2:42 PM CDTTornado WatchSPCAdair, Barton, Bates, Benton, Caldwell, Camden and 36 more7 hr

Nearby

Tornado Watches in Iowa, 2008Tornado Watches in Illinois, 2008Tornado Watches in Missouri, 2008Every tornado watch in 2008

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.