Alert archive / Nebraska / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 606

July 6, 201120 counties in Colorado; 11 counties in Kansas; 29 counties in Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Jul 6, 2011, 2:56 PM MDT for 20 counties in Colorado; 11 counties in Kansas; 29 counties in Nebraska. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Jul 6, 2011, 2:56 PM MDT (20:56 UTC)
Expired
Jul 6, 2011, 10:57 PM MDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 60 counties

Adams County, CO, Arapahoe County, CO, Bent County, CO, Cheyenne County, CO, Crowley County, CO, El Paso County, CO, Elbert County, CO, Kiowa County, CO, Kit Carson County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Otero County, CO, Phillips County, CO, Prowers County, CO, Pueblo County, CO, Sedgwick County, CO, Washington County, CO, Weld County, CO, Yuma County, CO, Cheyenne County, KS, Decatur County, KS, Gove County, KS, Greeley County, KS, Logan 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, Blaine County, NE, Box Butte County, NE, Brown 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, Hitchcock County, NE, Hooker County, NE, Keith County, NE, Keya Paha County, NE, Kimball County, NE, Lincoln County, NE, Logan County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Red Willow County, NE, Rock County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Thomas County, NE

The radar

The Cheyenne radar (KCYS), 185 km from the middle of the area, began a volume at 20:56 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
40%
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

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

IssuedProductOfficeCountiesLasted
Jul 6, 2:58 PM MDTSevere Thunderstorm WarningBOUElbert48 min
Jul 6, 3:28 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert47 min
Jul 6, 3:44 PM MDTFlash Flood WarningCYSDawes, Sioux3 hr
Jul 6, 4:33 PM MDTTornado WarningBOULogan, Weld42 min
Jul 6, 5:00 PM MDTSevere Thunderstorm WarningBOUWashington33 min
Jul 6, 5:06 PM MDTSevere Thunderstorm WarningBOUAdams, Logan, Morgan, Washington, Weld39 min
Jul 6, 5:26 PM MDTSevere Thunderstorm WarningBOUAdams, Denver, Weld49 min
Jul 6, 5:27 PM MDTSevere Thunderstorm WarningCYSBanner, Box Butte, Morrill, Scotts Bluff63 min
Jul 6, 5:31 PM MDTSevere Thunderstorm WarningLBFGarden, Sheridan44 min
Jul 6, 6:15 PM MDTSevere Thunderstorm WarningLBFArthur, Garden, Grant, Sheridan45 min
Jul 6, 8:47 PM MDTSevere Thunderstorm WarningGLDCheyenne, Rawlins, Sherman, Thomas41 min
Jul 6, 8:49 PM MDTSevere Thunderstorm WarningPUBBent, Prowers56 min
Jul 6, 9:39 PM MDTSevere Thunderstorm WarningGLDGove, Logan, Sherman, Thomas, Wallace66 min
Jul 6, 9:43 PM MDTSevere Thunderstorm WarningPUBKiowa, Prowers37 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 12:00Z, 8.9 hours before the alert went out and 138 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 12:00Z on 2011-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 161 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, Denver, CO at 12:00Z on 2011-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 square meters per square second.1939Sfc1 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
161 J/kg
Mixed-layer CIN
-159 J/kg
Mixed-layer LCL
1212 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
90 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
Jul 5, 6:01 PM MDTSevere Thunderstorm WatchSPCLogan, Morgan, Phillips, Sedgwick, Washington4 hr
Jul 5, 7:23 PM MDTMesoscale DiscussionSPCLogan, Phillips, Sedgwick, Washington, Yuma2 hr
Jul 5, 9:41 PM MDTMesoscale DiscussionSPCPhillips, Yuma2 hr
Jul 6, 2:38 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Bent, Boulder, Broomfield, Cheyenne and 21 more67 min
Jul 6, 5:16 PM MDTMesoscale DiscussionSPCBent, Cheyenne, Crowley, Elbert, El Paso, Kiowa and 11 more119 min
Jul 5, 6:07 PM MDTMesoscale DiscussionSPCAtchison, Brown, Cheyenne, Clay, Cloud, Decatur and 26 more113 min
Jul 5, 7:02 PM MDTSevere Thunderstorm WatchSPCAllen, Anderson, Atchison, Butler, Chase, Clay and 28 more7 hr

Nearby

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