Alert archive / Nebraska / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 693

September 28, 200715 counties in Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Sep 28, 2007, 4:55 PM MDT for 15 counties in Nebraska. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Sep 28, 2007, 4:55 PM MDT (22:55 UTC)
Expired
Sep 28, 2007, 10:40 PM MDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Arthur County, NE, Blaine County, NE, Chase County, NE, Custer County, NE, Frontier County, NE, Grant County, NE, Hayes County, NE, Hooker County, NE, Keith County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Perkins County, NE, Thomas County, NE

The radar

The North Platte radar (KLNX), 113 km from the middle of the area, began a volume at 22:55 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
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 28, 5:01 PM MDTSevere Thunderstorm WarningLBFCuster44 min
Sep 28, 5:22 PM MDTSevere Thunderstorm WarningLBFLincoln38 min
Sep 28, 5:34 PM MDTSevere Thunderstorm WarningLBFLincoln41 min
Sep 28, 5:43 PM MDTSevere Thunderstorm WarningLBFCuster47 min
Sep 28, 5:51 PM MDTSevere Thunderstorm WarningLBFLincoln24 min
Sep 28, 6:02 PM MDTSevere Thunderstorm WarningLBFMcPherson28 min
Sep 28, 6:13 PM MDTSevere Thunderstorm WarningLBFLincoln32 min
Sep 28, 6:27 PM MDTSevere Thunderstorm WarningLBFLincoln, Logan, McPherson33 min
Sep 28, 6:43 PM MDTSevere Thunderstorm WarningLBFMcPherson32 min
Sep 28, 6:46 PM MDTSevere Thunderstorm WarningLBFLincoln29 min
Sep 28, 7:11 PM MDTSevere Thunderstorm WarningLBFMcPherson, Thomas34 min
Sep 28, 7:22 PM MDTSevere Thunderstorm WarningLBFLogan23 min
Sep 28, 7:40 PM MDTSevere Thunderstorm WarningLBFCuster, Logan35 min
Sep 28, 7:43 PM MDTSevere Thunderstorm WarningLBFLogan, Thomas32 min
Sep 28, 8:14 PM MDTSevere Thunderstorm WarningLBFThomas31 min
Sep 28, 8:59 PM MDTSevere Thunderstorm WarningLBFBlaine31 min
Sep 28, 9:22 PM MDTSevere Thunderstorm WarningLBFLoup, Rock23 min
Sep 28, 9:47 PM MDTSevere Thunderstorm WarningLBFGarfield, Holt, Loup, Rock43 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

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 10.9 hours before the alert went out and 51 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, N. Platte/Lee Bi, NE at 12:00Z on 2007-09-28Temperature 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, N. Platte/Lee Bi, NE at 12:00Z on 2007-09-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 322 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
2279 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
322 m²/s²
0-3 km storm-relative helicity
517 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 28, 1:01 PM MDTMesoscale DiscussionSPCChase, Dundy, Hitchcock89 min
Sep 28, 2:03 PM MDTSevere Thunderstorm WatchSPCDundy, Hitchcock, Red Willow6 hr

Nearby

Severe Thunderstorm Watches in Nebraska, 2007Every severe thunderstorm watch in 2007

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.