Alert archive / Nebraska / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 522

July 15, 200725 counties in Nebraska

The Storm Prediction Center issued this severe thunderstorm watch at Jul 15, 2007, 6:27 PM CDT for 25 counties in Nebraska. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jul 15, 2007, 6:27 PM CDT (23:27 UTC)
Expired
Jul 15, 2007, 10:43 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 25 counties

Antelope County, NE, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Douglas County, NE, Knox County, NE, Lancaster County, NE, Madison County, NE, Otoe County, NE, Pierce County, NE, Platte County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE

The radar

The Omaha radar (KOAX), 116 km from the middle of the area, began a volume at 23:30 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
5%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 15, 7:04 PM CDTSevere Thunderstorm WarningOAXBoone26 min
Jul 15, 7:06 PM CDTSevere Thunderstorm WarningOAXPierce54 min
Jul 15, 7:12 PM CDTSevere Thunderstorm WarningOAXMadison63 min
Jul 15, 7:15 PM CDTSevere Thunderstorm WarningOAXKnox30 min
Jul 15, 7:57 PM CDTSevere Thunderstorm WarningOAXStanton63 min
Jul 15, 8:01 PM CDTSevere Thunderstorm WarningOAXWayne59 min
Jul 15, 8:36 PM CDTSevere Thunderstorm WarningOAXCedar43 min
Jul 15, 9:08 PM CDTSevere Thunderstorm WarningFSDDixon28 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, 11.5 hours before the alert went out and 116 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 2007-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 290 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 2007-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 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
290 J/kg
Mixed-layer CIN
-151 J/kg
Mixed-layer LCL
1359 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
159 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 15, 2:06 PM CDTMesoscale DiscussionSPCArthur, Blaine, Brown, Buffalo, Chase, Cherry and 24 more114 min
Jul 15, 2:37 PM CDTSevere Thunderstorm WatchSPCAdams, Arthur, Blaine, Boyd, Brown, Buffalo and 41 more7 hr
Jul 15, 5:14 PM CDTMesoscale DiscussionSPCAdams, Antelope, Boone, Buffalo, Butler, Clay and 32 more91 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.