Alert archive / Nebraska / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 588

August 12, 200736 counties in Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Aug 12, 2007, 1:57 PM CDT for 36 counties in Nebraska. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Aug 12, 2007, 1:57 PM CDT (18:57 UTC)
Expired
Aug 12, 2007, 7:31 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 36 counties

Adams County, NE, Antelope County, NE, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Howard County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Platte County, NE, Polk County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Washington County, NE, York County, NE

The radar

The Omaha radar (KOAX), 96 km from the middle of the area, began a volume at 18:56 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
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

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

IssuedProductOfficeCountiesLasted
Aug 12, 2:04 PM CDTSevere Thunderstorm WarningOAXAntelope46 min
Aug 12, 2:42 PM CDTSevere Thunderstorm WarningOAXBoone44 min
Aug 12, 2:50 PM CDTSevere Thunderstorm WarningGIDNance40 min
Aug 12, 3:15 PM CDTSevere Thunderstorm WarningOAXPlatte60 min
Aug 12, 3:16 PM CDTSevere Thunderstorm WarningGIDMerrick, Nance, Polk59 min
Aug 12, 3:41 PM CDTSevere Thunderstorm WarningOAXColfax48 min
Aug 12, 3:42 PM CDTSevere Thunderstorm WarningOAXButler48 min
Aug 12, 3:57 PM CDTSevere Thunderstorm WarningOAXSeward48 min
Aug 12, 4:01 PM CDTSevere Thunderstorm WarningOAXDodge44 min
Aug 12, 4:05 PM CDTSevere Thunderstorm WarningOAXSaunders55 min
Aug 12, 4:25 PM CDTSevere Thunderstorm WarningOAXLancaster35 min
Aug 12, 4:27 PM CDTSevere Thunderstorm WarningOAXButler22 min
Aug 12, 4:28 PM CDTSevere Thunderstorm WarningOAXWashington47 min
Aug 12, 4:36 PM CDTSevere Thunderstorm WarningOAXDouglas, Sarpy54 min
Aug 12, 4:46 PM CDTSevere Thunderstorm WarningOAXBurt44 min
Aug 12, 4:50 PM CDTFlash Flood WarningOAXCuming115 min
Aug 12, 4:53 PM CDTSevere Thunderstorm WarningOAXCuming35 min
Aug 12, 4:56 PM CDTSevere Thunderstorm WarningOAXSaunders34 min
Aug 12, 5:13 PM CDTSevere Thunderstorm WarningOAXWashington47 min
Aug 12, 5:26 PM CDTSevere Thunderstorm WarningOAXBurt36 min
Aug 12, 5:28 PM CDTSevere Thunderstorm WarningOAXDouglas, Sarpy32 min
Aug 12, 5:42 PM CDTFlash Flood WarningOAXSaunders4 hr
Aug 12, 5:44 PM CDTSevere Thunderstorm WarningOAXCass25 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

Omaha, NE (KOAX), launched 12:00Z, 7.0 hours before the alert went out and 96 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, Omaha, NE at 12:00Z on 2007-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3259 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, Omaha, NE at 12:00Z on 2007-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 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
3259 J/kg
Mixed-layer CIN
-153 J/kg
Mixed-layer LCL
1117 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 12, 11:20 AM CDTMesoscale DiscussionSPCAdams, Arthur, Buffalo, Butler, Cass, Chase and 38 more115 min
Aug 12, 2:52 PM CDTMesoscale DiscussionSPCAdams, Burt, Butler, Cass, Clay, Colfax and 24 more83 min

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.