Alert archive / Nebraska / Severe Thunderstorm Watches in 2006

Severe Thunderstorm Watch 708

August 10, 20064 counties in Iowa; 27 counties in Nebraska; Union County, South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Aug 10, 2006, 10:30 PM CDT for 4 counties in Iowa; 27 counties in Nebraska; Union County, South Dakota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Aug 10, 2006, 10:30 PM CDT (03:30 UTC)
Expired
Aug 11, 2006, 4:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 32 counties

Monona County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Antelope County, NE, Blaine County, NE, Boone County, NE, Burt County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Custer County, NE, Dakota County, NE, Dixon County, NE, Dodge County, NE, Garfield County, NE, Greeley County, NE, Howard County, NE, Knox County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Pierce County, NE, Platte County, NE, Sherman County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Wayne County, NE, Wheeler County, NE, Union County, SD

The radar

The Sioux Falls radar (KFSD), 153 km from the middle of the area, began a volume at 03:32 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
30%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 11, 12:01 AM CDTSevere Thunderstorm WarningOAXAntelope, Knox59 min
Aug 11, 12:25 AM CDTSevere Thunderstorm WarningOAXCedar50 min
Aug 11, 1:00 AM CDTSevere Thunderstorm WarningOAXAntelope45 min
Aug 11, 1:22 AM CDTSevere Thunderstorm WarningOAXPierce38 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 00:00Z, 3.5 hours before the alert went out and 163 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 00:00Z on 2006-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1714 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2006-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -21 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
1714 J/kg
Mixed-layer CIN
-127 J/kg
Mixed-layer LCL
1205 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
-21 m²/s²
0-3 km storm-relative helicity
6 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-1.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WWUS20 KWNS 110332
SEL8  
SPC WW 110332
IAZ000-NEZ000-SDZ000-110900-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 708
NWS STORM PREDICTION CENTER NORMAN OK
1030 PM CDT THU AUG 10 2006

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 

       WESTERN IOWA
       NORTHERN AND CENTRAL NEBRASKA
       FAR SOUTHEASTERN SOUTH DAKOTA

EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 1030 PM
UNTIL 400 AM CDT.

HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 50
STATUTE MILES EITHER SIDE OF A LINE FROM 30 MILES NORTHEAST OF
SIOUX CITY IOWA TO 30 MILES WEST NORTHWEST OF BROKEN BOW
NEBRASKA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 707...

DISCUSSION...MCS WITH EMBEDDED SUSTAINED STORMS/WEAK SUPERCELLS
EXPECTED TO CONTINUE MAINLY SSE INTO REGION OF MODERATE TO STRONG
INSTABILITY OVER NEB DURING THE NEXT FEW HOURS.  WHILE CIN WILL
INCREASE WITH TIME/INCREASING SWD EXTENT...GIVEN SYSTEM SUPPORT WITH
MODERATE NNW FLOW ALOFT/CONTINUED COLD POOL DEVELOPMENT...POTENTIAL
MAY PERSIST FOR ADDITIONAL WIND DAMAGE/HAIL.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION
VECTOR 33020.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 10, 7:07 PM CDTSevere Thunderstorm WatchSPCLyon6 hr
Aug 11, 2:07 AM CDTMesoscale DiscussionSPCMonona, Plymouth, Woodbury53 min
Aug 10, 9:29 PM CDTMesoscale DiscussionSPCAntelope, Blaine, Boone, Boyd, Brown, Cedar and 25 more91 min
Aug 11, 2:18 PM CDTMesoscale DiscussionSPCBox Butte, Cherry, Dawes, Sheridan117 min
Aug 11, 2:46 PM CDTSevere Thunderstorm WatchSPCCherry, Sheridan8 hr
Aug 11, 5:20 PM CDTMesoscale DiscussionSPCBoyd, Keya Paha85 min

Nearby

Severe Thunderstorm Watches in Nebraska, 2006Severe Thunderstorm Watches in Iowa, 2006Severe Thunderstorm Watches in South Dakota, 2006Every severe thunderstorm watch in 2006

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.