Alert archive / Nebraska / Severe Thunderstorm Watches in 2015

Severe Thunderstorm Watch 431

July 17, 201540 counties in Nebraska; 9 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jul 17, 2015, 3:03 PM MDT for 40 counties in Nebraska; 9 counties in South Dakota. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Jul 17, 2015, 3:03 PM MDT (21:03 UTC)
Expired
Jul 17, 2015, 10:56 PM MDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
65 kt
All 49 counties

Arthur County, NE, Banner County, NE, Blaine County, NE, Box Butte County, NE, Brown County, NE, Buffalo County, NE, Cherry County, NE, Custer County, NE, Dawes County, NE, Dawson County, NE, Deuel County, NE, Frontier County, NE, Garden County, NE, Garfield County, NE, Gosper County, NE, Grant County, NE, Greeley County, NE, Hayes 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, Merrick County, NE, Morrill County, NE, Nance County, NE, Perkins County, NE, Polk County, NE, Rock County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sherman County, NE, Sioux County, NE, Thomas County, NE, Valley County, NE, Wheeler County, NE, Bennett County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Jackson County, SD, Mellette County, SD, Pennington County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 153 km from the middle of the area, began a volume at 21:06 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
2%
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

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

IssuedProductOfficeCountiesLasted
Jul 17, 3:17 PM MDTSevere Thunderstorm WarningCYSDawes, Sioux58 min
Jul 17, 3:31 PM MDTSevere Thunderstorm WarningLBFLincoln44 min
Jul 17, 3:35 PM MDTSevere Thunderstorm WarningCYSBox Butte, Morrill28 min
Jul 17, 3:38 PM MDTSevere Thunderstorm WarningLBFKeith, Perkins52 min
Jul 17, 4:02 PM MDTSevere Thunderstorm WarningCYSSioux58 min
Jul 17, 4:07 PM MDTSevere Thunderstorm WarningLBFGarden, Sheridan53 min
Jul 17, 4:14 PM MDTSevere Thunderstorm WarningLBFLincoln, Logan46 min
Jul 17, 4:29 PM MDTSevere Thunderstorm WarningLBFKeith46 min
Jul 17, 4:40 PM MDTSevere Thunderstorm WarningLBFLincoln, Logan50 min
Jul 17, 4:43 PM MDTSevere Thunderstorm WarningLBFGarden, Grant, Sheridan47 min
Jul 17, 4:49 PM MDTSevere Thunderstorm WarningLBFLogan, Thomas25 min
Jul 17, 5:04 PM MDTSevere Thunderstorm WarningLBFKeith, Lincoln41 min
Jul 17, 5:12 PM MDTSevere Thunderstorm WarningLBFCuster, Lincoln48 min
Jul 17, 5:28 PM MDTSevere Thunderstorm WarningLBFGrant, Hooker47 min
Jul 17, 5:33 PM MDTSevere Thunderstorm WarningLBFCherry42 min
Jul 17, 5:43 PM MDTSevere Thunderstorm WarningLBFLincoln47 min
Jul 17, 5:48 PM MDTSevere Thunderstorm WarningLBFCuster, Garfield, Wheeler28 min
Jul 17, 5:51 PM MDTSevere Thunderstorm WarningGIDValley23 min
Jul 17, 6:06 PM MDTSevere Thunderstorm WarningLBFCherry, Hooker, Thomas39 min
Jul 17, 6:25 PM MDTSevere Thunderstorm WarningLBFLincoln50 min
Jul 17, 6:29 PM MDTSevere Thunderstorm WarningGIDValley31 min
Jul 17, 6:39 PM MDTSevere Thunderstorm WarningLBFBlaine, Brown, Cherry, Thomas51 min
Jul 17, 6:55 PM MDTSevere Thunderstorm WarningLBFBrown, Rock50 min
Jul 17, 7:37 PM MDTSevere Thunderstorm WarningLBFHolt38 min
Jul 17, 7:57 PM MDTSevere Thunderstorm WarningLBFCuster48 min
Jul 17, 8:17 PM MDTSevere Thunderstorm WarningGIDBuffalo, Dawson, Sherman43 min
Jul 17, 8:58 PM MDTSevere Thunderstorm WarningGIDBuffalo, Hall, Howard, Sherman31 min
Jul 17, 9:27 PM MDTSevere Thunderstorm WarningLBFCuster23 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 (KRAP), launched 12:00Z, 9.1 hours before the alert went out and 155 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 2015-07-17Temperature 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, Rapid City, SD at 12:00Z on 2015-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1565 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
296 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
Jul 17, 5:02 PM MDTMesoscale DiscussionSPCLogan, Phillips, Sedgwick118 min
Jul 17, 2:36 PM MDTMesoscale DiscussionSPCArthur, Banner, Blaine, Box Butte, Brown, Cherry and 15 more54 min
Jul 17, 4:43 PM MDTMesoscale DiscussionSPCAntelope, Boone, Cedar, Colfax, Cuming, Dixon and 12 more92 min
Jul 17, 12:10 PM MDTMesoscale DiscussionSPCBeadle, Brookings, Brown, Clark, Codington, Day and 17 more2 hr
Jul 17, 2:43 PM MDTSevere Thunderstorm WatchSPCBeadle, Brookings, Brown, Buffalo, Campbell, Clark and 21 more7 hr

Nearby

Severe Thunderstorm Watches in Nebraska, 2015Severe Thunderstorm Watches in South Dakota, 2015Every severe thunderstorm watch in 2015

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.