Alert archive / Kansas / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 765

August 10, 2011Cheyenne County, Kit Carson County, Yuma County, Colorado; 9 counties in Kansas; Dundy County, Hitchcock County, Red Willow County, Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Aug 10, 2011, 6:50 PM MDT for Cheyenne County, Kit Carson County, Yuma County, Colorado; 9 counties in Kansas; Dundy County, Hitchcock County, Red Willow County, Nebraska. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Aug 10, 2011, 6:50 PM MDT (00:50 UTC)
Expired
Aug 10, 2011, 9:48 PM MDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
65 kt

Counties Cheyenne County, CO, Kit Carson County, CO, Yuma County, CO, Cheyenne County, KS, Decatur County, KS, Gove County, KS, Logan County, KS, Rawlins County, KS, Sheridan County, KS, Sherman County, KS, Thomas County, KS, Wallace County, KS, Dundy County, NE, Hitchcock County, NE, Red Willow County, NE

The radar

The Goodland radar (KGLD), 5 km from the middle of the area, began a volume at 00:53 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
10%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
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
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 10, 9:00 PM MDTSevere Thunderstorm WarningGLDYuma28 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, 0.8 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 00:00Z on 2011-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 87 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 2011-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.19395878Sfc1 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
87 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
3466 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
149 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.

IssuedProductOfficeCountiesLasted
Aug 10, 9:10 PM MDTMesoscale DiscussionSPCPhillips, Sedgwick95 min
Aug 11, 2:15 AM MDTMesoscale DiscussionSPCHarper90 min
Aug 11, 3:15 PM MDTMesoscale DiscussionSPCArthur, Cherry, Garden, Grant, Hooker, Logan and 3 more60 min
Aug 11, 3:38 PM MDTTornado WatchSPCBlaine, Boyd, Brown, Cherry, Custer, Garfield and 9 more9 hr
Aug 11, 5:38 PM MDTMesoscale DiscussionSPCAntelope, Boone, Burt, Cedar, Colfax, Cuming and 13 more97 min

Nearby

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