Alert archive / Nebraska / Tornado Watches in 2009

Tornado Watch 452

June 17, 20095 counties in Iowa; 39 counties in Nebraska

The Storm Prediction Center issued this tornado watch at Jun 17, 2009, 9:04 PM CDT for 5 counties in Iowa; 39 counties in Nebraska. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jun 17, 2009, 9:04 PM CDT (02:04 UTC)
Expired
Jun 17, 2009, 11:36 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 44 counties

Fremont County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Adams County, NE, Buffalo County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Dawson County, NE, Douglas County, NE, Fillmore County, NE, Franklin County, NE, Furnas County, NE, Gage County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Howard County, NE, Jefferson County, NE, Johnson County, NE, Kearney County, NE, Lancaster County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Nuckolls County, NE, Otoe County, NE, Pawnee County, NE, Phelps County, NE, Polk County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Thayer County, NE, Valley County, NE, Webster County, NE, York County, NE

The radar

The Grand Island radar (KUEX), 93 km from the middle of the area, began a volume at 02:04 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 17, 9:22 PM CDTTornado Warning EmergencyGIDHamilton23 min
Jun 17, 9:29 PM CDTSevere Thunderstorm WarningGIDHamilton, York35 min
Jun 17, 10:01 PM CDTSevere Thunderstorm WarningGIDYork44 min
Jun 17, 10:10 PM CDTSevere Thunderstorm WarningOAXSeward35 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, 2.1 hours before the alert went out and 118 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 2009-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1256 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 2009-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
1256 J/kg
Mixed-layer CIN
-128 J/kg
Mixed-layer LCL
1892 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 17, 7:01 PM CDTTornado WatchSPCAllamakee, Bremer, Butler, Cerro Gordo, Chickasaw, Clayton and 12 more5 hr
Jun 17, 8:04 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Cass, Fremont, Guthrie and 8 more56 min
Jun 17, 11:07 PM CDTMesoscale DiscussionSPCAllamakee, Chickasaw, Clayton, Fayette, Howard, Winneshiek53 min
Jun 17, 11:33 PM CDTMesoscale DiscussionSPCFremont, Mills, Pottawattamie87 min
Jun 17, 11:53 PM CDTSevere Thunderstorm WatchSPCAdair, Allamakee, Appanoose, Audubon, Benton, Black Hawk and 68 more6 hr
Jun 18, 1:01 AM CDTMesoscale DiscussionSPCAppanoose, Davis, Decatur, Des Moines, Henry, Jefferson and 6 more89 min
Jun 18, 3:20 AM CDTMesoscale DiscussionSPCDavis, Des Moines, Henry, Iowa, Jefferson, Johnson and 12 more85 min
Jun 18, 4:20 AM CDTSevere Thunderstorm WatchSPCBuena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more4 hr
Jun 18, 6:41 AM CDTMesoscale DiscussionSPCBlack Hawk, Boone, Bremer, Buchanan, Buena Vista, Butler and 31 more94 min
Jun 18, 7:04 AM CDTSevere Thunderstorm WatchSPCBlack Hawk, Bremer, Butler, Calhoun, Cerro Gordo, Chickasaw and 20 more4 hr
Jun 18, 9:42 AM CDTMesoscale DiscussionSPCBenton, Buchanan, Cedar, Clinton, Delaware, Dubuque and 8 more93 min
Jun 18, 10:11 AM CDTSevere Thunderstorm WatchSPCBenton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 11 more6 hr
Jun 18, 1:17 PM CDTMesoscale DiscussionSPCBenton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 11 more88 min
Jun 18, 3:15 PM CDTMesoscale DiscussionSPCBlack Hawk, Boone, Bremer, Buena Vista, Butler, Calhoun and 25 more90 min
Jun 18, 6:52 PM CDTMesoscale DiscussionSPCLyon, Sioux113 min
Jun 17, 7:16 PM CDTTornado WatchSPCBenton, Camden, Crawford, Dent, Franklin, Iron and 19 more4 hr
Jun 17, 10:34 PM CDTMesoscale DiscussionSPCArthur, Banner, Chase, Cheyenne, Deuel, Garden and 12 more56 min
Jun 17, 11:01 PM CDTSevere Thunderstorm WatchSPCArthur, Blaine, Boyd, Brown, Cherry, Cheyenne and 19 more6 hr
Jun 18, 1:46 AM CDTMesoscale DiscussionSPCArthur, Blaine, Boyd, Brown, Cherry, Cheyenne and 20 more89 min

Nearby

Tornado Watches in Nebraska, 2009Tornado Watches in Iowa, 2009Every tornado 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.