Alert archive / Nebraska / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 760

August 9, 20117 counties in Colorado; 13 counties in Kansas; 17 counties in Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Aug 9, 2011, 8:51 PM MDT for 7 counties in Colorado; 13 counties in Kansas; 17 counties in Nebraska. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Aug 9, 2011, 8:51 PM MDT (02:51 UTC)
Expired
Aug 10, 2011, 4:00 AM MDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 37 counties

Cheyenne County, CO, Kit Carson County, CO, Logan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Cheyenne County, KS, Decatur County, KS, Gove County, KS, Graham County, KS, Greeley County, KS, Logan County, KS, Norton County, KS, Rawlins County, KS, Sheridan County, KS, Sherman County, KS, Thomas County, KS, Wallace County, KS, Wichita County, KS, Arthur County, NE, Banner County, NE, Chase County, NE, Cheyenne County, NE, Deuel County, NE, Dundy County, NE, Frontier County, NE, Garden County, NE, Hayes County, NE, Hitchcock County, NE, Keith County, NE, Kimball County, NE, Lincoln County, NE, Morrill County, NE, Perkins County, NE, Red Willow County, NE, Scotts Bluff County, NE

The radar

The Goodland radar (KGLD), 145 km from the middle of the area, began a volume at 02:54 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
10%
Ten or more severe hail reports
60%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 9, 9:30 PM MDTSevere Thunderstorm WarningGLDGraham33 min
Aug 9, 9:42 PM MDTSevere Thunderstorm WarningCYSCheyenne, Morrill30 min
Aug 9, 9:45 PM MDTSevere Thunderstorm WarningBOULogan, Sedgwick45 min
Aug 9, 9:49 PM MDTSevere Thunderstorm WarningLBFDeuel, Garden41 min
Aug 9, 9:53 PM MDTSevere Thunderstorm WarningLBFChase, Perkins45 min
Aug 9, 10:28 PM MDTSevere Thunderstorm WarningLBFChase, Deuel, Keith, Perkins29 min
Aug 9, 10:30 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick30 min
Aug 9, 10:55 PM MDTSevere Thunderstorm WarningLBFChase45 min
Aug 9, 11:03 PM MDTSevere Thunderstorm WarningGLDDundy42 min
Aug 9, 11:13 PM MDTSevere Thunderstorm WarningGLDDecatur44 min
Aug 9, 11:44 PM MDTSevere Thunderstorm WarningGLDCheyenne, Rawlins31 min
Aug 10, 1:19 AM MDTSevere Thunderstorm WarningGLDDecatur, Gove, Graham, Sheridan56 min
Aug 10, 1:35 AM MDTSevere Thunderstorm WarningGLDDundy, Hitchcock29 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

Denver, CO (KDNR), launched 00:00Z, 2.9 hours before the alert went out and 83 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, Denver, CO at 00:00Z on 2011-08-10Temperature 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, Denver, CO at 00:00Z on 2011-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -2 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
5160 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
24 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
Aug 9, 8:26 PM MDTMesoscale DiscussionSPCLogan, Morgan, Phillips, Sedgwick, Washington, Weld and 1 more64 min
Aug 10, 3:42 PM MDTMesoscale DiscussionSPCLogan, Phillips, Sedgwick63 min
Aug 10, 4:03 PM MDTSevere Thunderstorm WatchSPCLogan, Phillips, Sedgwick, Washington6 hr
Aug 10, 5:54 PM MDTMesoscale DiscussionSPCCheyenne, Kit Carson, Logan, Phillips, Sedgwick, Washington and 1 more66 min
Aug 9, 7:27 PM MDTMesoscale DiscussionSPCClark, Comanche, Kiowa, Meade, Seward2 hr
Aug 9, 10:11 PM MDTMesoscale DiscussionSPCBarber, Barton, Butler, Chautauqua, Cowley, Edwards and 28 more94 min
Aug 10, 2:25 AM MDTMesoscale DiscussionSPCBarton, Butler, Cowley, Ellis, Ellsworth, Greenwood and 12 more65 min
Aug 10, 2:42 AM MDTSevere Thunderstorm WatchSPCBarton, Butler, Chase, Chautauqua, Cowley, Elk and 17 more3 hr
Aug 10, 2:53 AM MDTMesoscale DiscussionSPCCheyenne, Decatur, Gove, Rawlins, Sheridan, Sherman and 1 more67 min

Nearby

Severe Thunderstorm Watches in Nebraska, 2011Severe Thunderstorm Watches in Kansas, 2011Severe Thunderstorm Watches in Colorado, 2011Every 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.