Alert archive / Nebraska / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 612

July 8, 20114 states

The Storm Prediction Center issued this severe thunderstorm watch at Jul 8, 2011, 3:48 PM MDT for 4 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jul 8, 2011, 3:48 PM MDT (21:48 UTC)
Expired: Jul 8, 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 57 counties

Cheyenne County, CO, Kit Carson County, CO, Lincoln County, CO, Logan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Cheyenne County, KS, Logan County, KS, Rawlins County, KS, Sherman County, KS, Thomas County, KS, Wallace County, KS, 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, Hayes County, NE, Hitchcock County, NE, Hooker County, NE, Keith County, NE, Kimball County, NE, Lincoln County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Bennett County, SD, Butte County, SD, Campbell County, SD, Corson County, SD, Custer County, SD, Dewey County, SD, Fall River County, SD, Haakon County, SD, Harding County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Meade County, SD, Mellette County, SD, Pennington County, SD, Perkins County, SD, Stanley County, SD, Todd County, SD, Walworth County, SD, Ziebach County, SD

The radar

The Rapid City radar (KUDX), 111 km from the middle of the area, began a volume at 21:49 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: 30%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 90%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 8, 4:11 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	49 min
Jul 8, 4:29 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne, Kimball	46 min
Jul 8, 4:57 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	16 min
Jul 8, 5:08 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne	52 min
Jul 8, 5:26 PM MDT	Severe Thunderstorm Warning	LBF	Deuel, Garden	49 min
Jul 8, 5:57 PM MDT	Severe Thunderstorm Warning	GLD	Kit Carson, Yuma	33 min
Jul 8, 6:04 PM MDT	Severe Thunderstorm Warning	BOU	Phillips, Sedgwick	56 min
Jul 8, 6:10 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	31 min
Jul 8, 6:19 PM MDT	Severe Thunderstorm Warning	GLD	Cheyenne, Kit Carson	26 min
Jul 8, 6:24 PM MDT	Severe Thunderstorm Warning	GLD	Kit Carson, Yuma	43 min
Jul 8, 6:42 PM MDT	Severe Thunderstorm Warning	GLD	Cheyenne, Kit Carson	33 min
Jul 8, 7:13 PM MDT	Severe Thunderstorm Warning	GLD	Kit Carson, Yuma	47 min
Jul 8, 7:41 PM MDT	Severe Thunderstorm Warning	GLD	Kit Carson, Yuma	49 min
Jul 8, 8:03 PM MDT	Severe Thunderstorm Warning	GLD	Kit Carson, Yuma	42 min
Jul 8, 8:11 PM MDT	Severe Thunderstorm Warning	BOU	Phillips, Sedgwick	34 min
Jul 8, 8:26 PM MDT	Severe Thunderstorm Warning	LBF	Perkins	49 min
Jul 8, 8:44 PM MDT	Flash Flood Warning	LBF	Logan, McPherson, Thomas	2 min
Jul 8, 8:50 PM MDT	Flash Flood Warning	LBF	Chase, Perkins	6 hr
Jul 8, 9:29 PM MDT	Severe Thunderstorm Warning	ABR	Jones, Lyman, Stanley	31 min
Jul 8, 9:49 PM MDT	Severe Thunderstorm Warning	ABR	Hughes, Stanley, Sully	26 min
Jul 8, 10:01 PM MDT	Severe Thunderstorm Warning	GLD	Yuma	30 min
Jul 8, 10:02 PM MDT	Flash Flood Warning	BOU	Phillips, Sedgwick	6 hr
Jul 8, 10:24 PM MDT	Severe Thunderstorm Warning	ABR	Jones, Lyman, Stanley	35 min
Jul 8, 10:29 PM MDT	Flash Flood Warning	GLD	Yuma	3 hr
Jul 8, 10:33 PM MDT	Flash Flood Warning	BOU	Washington	4 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

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 9.8 hours before the alert went out and 286 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: 110 J/kg
Mixed-layer CIN: -178 J/kg
Mixed-layer LCL: 1340 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 47 m²/s²
0-3 km storm-relative helicity: 100 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 8, 1:43 PM MDT	Mesoscale Discussion	SPC	Adams, Arapahoe, Bent, Boulder, Broomfield, Crowley and 18 more	92 min
Jul 8, 3:29 PM MDT	Mesoscale Discussion	SPC	Adams, Arapahoe, Kit Carson, Logan, Morgan, Phillips and 3 more	2 hr
Jul 8, 4:38 PM MDT	Mesoscale Discussion	SPC	Marshall, Roberts	2 hr
Jul 8, 5:02 PM MDT	Tornado Watch	SPC	Marshall, Roberts	7 hr

Nearby

Severe Thunderstorm Watches in Nebraska, 2011 Severe Thunderstorm Watches in South Dakota, 2011 Severe Thunderstorm Watches in Colorado, 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.