Alert archive / Iowa / Tornado Watches in 2007

Tornado Watch 525

July 16, 20075 counties in Illinois; 45 counties in Iowa

The Storm Prediction Center issued this tornado watch at Jul 16, 2007, 3:38 PM CDT for 5 counties in Illinois; 45 counties in Iowa. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Jul 16, 2007, 3:38 PM CDT (20:38 UTC)
Expired
Jul 16, 2007, 11:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 50 counties

Appanoose County, IA, Benton County, IA, Boone County, IA, Buchanan County, IA, Cedar County, IA, Clarke County, IA, Clayton County, IA, Clinton County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Fayette County, IA, Greene 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, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Muscatine County, IA, Polk County, IA, Poweshiek County, IA, Scott County, IA, Story County, IA, Tama County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Winneshiek County, IA, Hancock County, IL, Henderson County, IL, Mercer County, IL, Rock Island County, IL, Warren County, IL

The radar

The Des Moines radar (KDMX), 83 km from the middle of the area, began a volume at 20:40 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
50%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
80%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
70%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 16, 3:39 PM CDTSevere Thunderstorm WarningDVNJohnson51 min
Jul 16, 4:18 PM CDTTornado WarningDVNJohnson42 min
Jul 16, 4:44 PM CDTFlash Flood WarningDVNJohnson6 hr
Jul 16, 4:49 PM CDTSevere Thunderstorm WarningDVNWashington56 min
Jul 16, 5:08 PM CDTSevere Thunderstorm WarningDVNJohnson40 min
Jul 16, 5:36 PM CDTTornado WarningDVNWashington39 min
Jul 16, 5:40 PM CDTFlash Flood WarningDVNWashington6 hr
Jul 16, 6:01 PM CDTSevere Thunderstorm WarningARXFayette59 min
Jul 16, 6:04 PM CDTSevere Thunderstorm WarningDVNHenry56 min
Jul 16, 6:11 PM CDTSevere Thunderstorm WarningARXFayette46 min
Jul 16, 6:13 PM CDTSevere Thunderstorm WarningDVNJefferson, Keokuk62 min
Jul 16, 6:26 PM CDTTornado WarningDVNJefferson49 min
Jul 16, 6:51 PM CDTSevere Thunderstorm WarningDVNBenton, Linn54 min
Jul 16, 7:12 PM CDTSevere Thunderstorm WarningDVNJefferson, Van Buren63 min
Jul 16, 7:35 PM CDTSevere Thunderstorm WarningARXChickasaw, Howard, Winneshiek25 min
Jul 16, 7:48 PM CDTSevere Thunderstorm WarningDVNLinn42 min
Jul 16, 8:00 PM CDTSevere Thunderstorm WarningARXWinneshiek11 min
Jul 16, 8:26 PM CDTSevere Thunderstorm WarningDVNVan Buren34 min
Jul 16, 8:29 PM CDTTornado WarningDMXBlack Hawk, Grundy, Tama31 min
Jul 16, 8:44 PM CDTSevere Thunderstorm WarningARXFayette29 min
Jul 16, 8:50 PM CDTSevere Thunderstorm WarningDVNBenton, Buchanan55 min
Jul 16, 9:37 PM CDTSevere Thunderstorm WarningDVNLinn53 min
Jul 16, 9:51 PM CDTFlash Flood WarningDVNLinn4 hr

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 12:00Z, 8.6 hours before the alert went out and 206 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 2007-07-16Temperature 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 12:00Z on 2007-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 square meters per square second.193958Sfc1 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
1487 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 16, 6:36 PM CDTMesoscale DiscussionSPCAdams, Brown, Hancock, McDonough, Pike, Schuyler84 min
Jul 15, 9:37 PM CDTMesoscale DiscussionSPCHarrison, Mills, Montgomery, Pottawattamie83 min
Jul 16, 1:36 PM CDTMesoscale DiscussionSPCBuena Vista, Cerro Gordo, Clay, Dickinson, Emmet, Franklin and 13 more114 min
Jul 16, 2:07 PM CDTTornado WatchSPCBlack Hawk, Bremer, Buena Vista, Butler, Calhoun, Cerro Gordo and 28 more8 hr
Jul 16, 3:11 PM CDTMesoscale DiscussionSPCBenton, Black Hawk, Bremer, Buchanan, Clayton, Delaware and 12 more2 hr
Jul 16, 5:24 PM CDTMesoscale DiscussionSPCBenton, Black Hawk, Boone, Bremer, Buchanan, Butler and 47 more2 hr

Nearby

Tornado Watches in Iowa, 2007Tornado Watches in Illinois, 2007Every tornado watch in 2007

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.