Alert archive / Nebraska / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 474

June 13, 201110 counties in Colorado; 23 counties in Nebraska; 6 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jun 13, 2011, 4:24 PM MDT for 10 counties in Colorado; 23 counties in Nebraska; 6 counties in South Dakota. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jun 13, 2011, 4:24 PM MDT (22:24 UTC)
Expired: Jun 13, 2011, 11:00 PM MDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 39 counties

Cheyenne County, CO, Elbert County, CO, Kit Carson County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Arthur County, NE, Banner County, NE, Box Butte County, NE, Chase County, NE, Cherry County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Dundy County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keith County, NE, Kimball County, NE, Lincoln County, NE, Logan County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Thomas County, NE, Bennett County, SD, Fall River County, SD, Jackson County, SD, Mellette County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 179 km from the middle of the area, began a volume at 22:24 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: 30%
One or more gusts of 65 knots or more: 30%
Ten or more severe hail reports: 40%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 80%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 13, 4:26 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln, Washington	16 min
Jun 13, 4:49 PM MDT	Severe Thunderstorm Warning	BOU	Washington	41 min
Jun 13, 5:04 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	41 min
Jun 13, 5:07 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes, Sioux	53 min
Jun 13, 5:21 PM MDT	Severe Thunderstorm Warning	GLD	Cheyenne	54 min
Jun 13, 5:26 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Cheyenne, Kimball, Morrill	64 min
Jun 13, 5:33 PM MDT	Severe Thunderstorm Warning	BOU	Morgan, Washington	32 min
Jun 13, 5:39 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	51 min
Jun 13, 5:48 PM MDT	Tornado Warning	LBF	Cherry	27 min
Jun 13, 5:54 PM MDT	Severe Thunderstorm Warning	GLD	Cheyenne	26 min
Jun 13, 5:55 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes	30 min
Jun 13, 6:07 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	38 min
Jun 13, 6:14 PM MDT	Tornado Warning	LBF	Cherry	31 min
Jun 13, 6:21 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne	54 min
Jun 13, 6:30 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	45 min
Jun 13, 6:59 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	29 min
Jun 13, 7:02 PM MDT	Severe Thunderstorm Warning	LBF	Deuel	47 min
Jun 13, 7:06 PM MDT	Severe Thunderstorm Warning	BOU	Logan, Sedgwick	45 min
Jun 13, 7:13 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne	28 min
Jun 13, 7:13 PM MDT	Severe Thunderstorm Warning	LBF	Garden	47 min
Jun 13, 7:15 PM MDT	Severe Thunderstorm Warning	LBF	Cherry	45 min
Jun 13, 7:16 PM MDT	Severe Thunderstorm Warning	UNR	Bennett, Todd	27 min
Jun 13, 7:27 PM MDT	Severe Thunderstorm Warning	LBF	Cherry, Grant	48 min
Jun 13, 7:46 PM MDT	Severe Thunderstorm Warning	LBF	Grant	59 min
Jun 13, 8:07 PM MDT	Severe Thunderstorm Warning	UNR	Bennett, Jackson	38 min
Jun 13, 9:45 PM MDT	Severe Thunderstorm Warning	UNR	Jackson, Pennington	60 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

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 10.4 hours before the alert went out and 185 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2140 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 486 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 86 m²/s²
Significant tornado parameter: 1.1
Supercell composite: 4.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 13, 1:53 PM MDT	Mesoscale Discussion	SPC	Logan, Morgan, Phillips, Sedgwick, Weld	2 hr
Jun 12, 6:07 PM MDT	Mesoscale Discussion	SPC	Brown, Buffalo, Corson, Dewey, Edmunds, Faulk and 16 more	53 min
Jun 12, 6:33 PM MDT	Severe Thunderstorm Watch	SPC	Buffalo, Campbell, Corson, Dewey, Haakon, Hughes and 12 more	6 hr
Jun 12, 8:55 PM MDT	Mesoscale Discussion	SPC	Bennett, Campbell, Corson, Dewey, Haakon, Hughes and 11 more	65 min
Jun 13, 12:44 AM MDT	Mesoscale Discussion	SPC	Jones, Lyman, Mellette, Todd, Tripp	61 min

Nearby

Severe Thunderstorm Watches in Nebraska, 2011 Severe Thunderstorm Watches in Colorado, 2011 Severe Thunderstorm Watches in South Dakota, 2011 Every severe thunderstorm watch in 2011

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.