Alert archive / Iowa / Severe Thunderstorm Watches in 2016

Severe Thunderstorm Watch 344

July 7, 201643 counties in Iowa

The Storm Prediction Center issued this severe thunderstorm watch at Jul 7, 2016, 12:47 AM CDT for 43 counties in Iowa. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jul 7, 2016, 12:47 AM CDT (05:47 UTC)
Expired
Jul 7, 2016, 4:55 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 43 counties

Adair County, IA, Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Crawford County, IA, Dallas County, IA, Emmet County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Howard County, IA, Humboldt County, IA, Jasper County, IA, Kossuth County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Mitchell County, IA, Palo Alto County, IA, Pocahontas County, IA, Polk County, IA, Poweshiek County, IA, Sac County, IA, Story County, IA, Tama County, IA, Warren County, IA, Webster County, IA, Winnebago County, IA, Worth County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 42 km from the middle of the area, began a volume at 05:51 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
5%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 7, 12:52 AM CDTSevere Thunderstorm WarningDMXCalhoun, Carroll, Greene, Pocahontas, Sac, Webster38 min
Jul 7, 1:09 AM CDTSevere Thunderstorm WarningDMXPalo Alto36 min
Jul 7, 1:22 AM CDTSevere Thunderstorm WarningDMXEmmet, Kossuth, Palo Alto, Pocahontas38 min
Jul 7, 2:43 AM CDTSevere Thunderstorm WarningDMXWorth32 min
Jul 7, 2:50 AM CDTSevere Thunderstorm WarningARXMitchell40 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, 5.8 hours before the alert went out and 224 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 2016-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3450 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 2016-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
3450 J/kg
Mixed-layer CIN
-78 J/kg
Mixed-layer LCL
1344 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
102 m²/s²
Significant tornado parameter
0.7
Supercell composite
7.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 6, 7:38 PM CDTSevere Thunderstorm WatchSPCBuena Vista, Cherokee, Clay, Dickinson, Harrison, Ida and 7 more6 hr
Jul 7, 12:30 AM CDTMesoscale DiscussionSPCAudubon, Benton, Black Hawk, Boone, Bremer, Buchanan and 51 more90 min
Jul 7, 1:22 AM CDTMesoscale DiscussionSPCDecatur, Fremont, Page, Ringgold, Taylor, Wayne83 min
Jul 7, 1:37 AM CDTSevere Thunderstorm WatchSPCAdams, Appanoose, Clarke, Davis, Decatur, Fremont and 11 more6 hr
Jul 7, 3:52 AM CDTMesoscale DiscussionSPCAllamakee, Black Hawk, Bremer, Buchanan, Chickasaw, Fayette and 8 more83 min
Jul 7, 4:27 AM CDTMesoscale DiscussionSPCAdams, Appanoose, Clarke, Davis, Decatur, Lucas and 6 more93 min
Jul 7, 5:26 AM CDTMesoscale DiscussionSPCAppanoose, Clarke, Davis, Decatur, Lucas, Monroe and 2 more2 hr
Jul 7, 6:01 AM CDTSevere Thunderstorm WatchSPCDes Moines, Henry, Jefferson, Lee, Van Buren6 hr
Jul 7, 8:10 AM CDTMesoscale DiscussionSPCDes Moines, Lee95 min
Jul 7, 1:50 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Boone, Buena Vista, Calhoun and 41 more115 min
Jul 7, 3:54 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Audubon, Boone, Buena Vista, Calhoun and 37 more5 hr
Jul 7, 6:30 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Black Hawk, Boone, Bremer and 39 more2 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2016Every severe thunderstorm watch in 2016

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.