Alert archive / Nebraska / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 736

August 7, 201127 counties in Nebraska; 8 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Aug 7, 2011, 1:58 PM MDT for 27 counties in Nebraska; 8 counties in South Dakota. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Aug 7, 2011, 1:58 PM MDT (19:58 UTC)
Expired
Aug 7, 2011, 10:00 PM MDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 35 counties

Arthur County, NE, Blaine County, NE, Brown County, NE, Buffalo County, NE, Cherry County, NE, Custer County, NE, Dawson County, NE, Garden County, NE, Garfield County, NE, Grant County, NE, Greeley County, NE, Holt County, NE, Hooker County, NE, Howard County, NE, Keith County, NE, Keya Paha County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Perkins County, NE, Rock County, NE, Sheridan County, NE, Sherman County, NE, Thomas County, NE, Valley County, NE, Wheeler County, NE, Bennett County, SD, Custer County, SD, Fall River County, SD, Jackson County, SD, Mellette County, SD, Pennington County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 110 km from the middle of the area, began a volume at 19:59 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
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 7, 2:27 PM MDTSevere Thunderstorm WarningUNRPennington63 min
Aug 7, 2:53 PM MDTSevere Thunderstorm WarningUNRCuster82 min
Aug 7, 3:56 PM MDTTornado WarningUNRCuster29 min
Aug 7, 4:05 PM MDTSevere Thunderstorm WarningUNRCuster, Pennington55 min
Aug 7, 4:28 PM MDTSevere Thunderstorm WarningUNR62 min
Aug 7, 4:41 PM MDTSevere Thunderstorm WarningLBFLincoln49 min
Aug 7, 4:47 PM MDTSevere Thunderstorm WarningUNRJackson58 min
Aug 7, 5:04 PM MDTSevere Thunderstorm WarningLBFKeith, Perkins41 min
Aug 7, 5:05 PM MDTSevere Thunderstorm WarningUNRBennett, Jackson55 min
Aug 7, 5:19 PM MDTSevere Thunderstorm WarningLBFLincoln36 min
Aug 7, 5:20 PM MDTSevere Thunderstorm WarningUNRJackson, Mellette55 min
Aug 7, 5:37 PM MDTSevere Thunderstorm WarningUNRTodd53 min
Aug 7, 5:49 PM MDTSevere Thunderstorm WarningUNRBennett, Jackson, Mellette, Todd56 min
Aug 7, 5:52 PM MDTSevere Thunderstorm WarningLBFCherry53 min
Aug 7, 5:56 PM MDTSevere Thunderstorm WarningGIDDawson49 min
Aug 7, 5:58 PM MDTSevere Thunderstorm WarningLBFCherry, Sheridan47 min
Aug 7, 6:02 PM MDTSevere Thunderstorm WarningUNRBennett, Todd43 min
Aug 7, 6:28 PM MDTSevere Thunderstorm WarningGIDDawson47 min
Aug 7, 6:31 PM MDTSevere Thunderstorm WarningUNRTodd59 min
Aug 7, 6:39 PM MDTSevere Thunderstorm WarningLBFCherry66 min
Aug 7, 6:43 PM MDTSevere Thunderstorm WarningGIDBuffalo, Sherman32 min
Aug 7, 7:10 PM MDTSevere Thunderstorm WarningLBFBrown, Cherry, Keya Paha, Rock50 min
Aug 7, 7:12 PM MDTSevere Thunderstorm WarningGIDBuffalo, Hall, Howard, Sherman33 min
Aug 7, 7:49 PM MDTSevere Thunderstorm WarningLBFBoyd, Brown, Holt, Keya Paha, Rock56 min
Aug 7, 8:34 PM MDTSevere Thunderstorm WarningLBFBoyd, Garfield, Holt, Keya Paha, Rock, Wheeler56 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

Rapid City, SD (KUNR), launched 12:00Z, 8.0 hours before the alert went out and 192 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, Rapid City, SD at 12:00Z on 2011-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 561 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, Rapid City, SD at 12:00Z on 2011-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 square meters per square second.193958Sfc1 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
561 J/kg
Mixed-layer CIN
-335 J/kg
Mixed-layer LCL
1423 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
136 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 6, 7:10 PM MDTMesoscale DiscussionSPCBoone, Burt, Butler, Cass, Colfax, Cuming and 23 more2 hr
Aug 7, 9:48 AM MDTMesoscale DiscussionSPCNuckolls, Thayer117 min
Aug 7, 12:23 PM MDTMesoscale DiscussionSPCArthur, Blaine, Brown, Cherry, Custer, Grant and 5 more67 min
Aug 7, 5:35 PM MDTMesoscale DiscussionSPCAdams, Arthur, Blaine, Boyd, Brown, Buffalo and 25 more115 min

Nearby

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