Alert archive / Nebraska / Severe Thunderstorm Watches in 2001

Severe Thunderstorm Watch 521

July 7, 200111 counties in Nebraska; Fall River County, Oglala Lakota County, South Dakota; Goshen County, Laramie County, Niobrara County, Wyoming

The Storm Prediction Center issued this severe thunderstorm watch at Jul 7, 2001, 4:45 PM MDT for 11 counties in Nebraska; Fall River County, Oglala Lakota County, South Dakota; Goshen County, Laramie County, Niobrara County, Wyoming. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jul 7, 2001, 4:45 PM MDT (22:45 UTC)
Expired
Jul 7, 2001, 10:00 PM MDT
In force
5 hr
Issued by
the Storm Prediction Center

Counties Banner County, NE, Box Butte County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Garden County, NE, Kimball County, NE, Morrill County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Fall River County, SD, Oglala Lakota County, SD, Goshen County, WY, Laramie County, WY, Niobrara County, WY

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 7, 5:00 PM MDTSevere Thunderstorm WarningCYSLaramie45 min
Jul 7, 5:57 PM MDTSevere Thunderstorm WarningCYSSioux48 min
Jul 7, 6:06 PM MDTTornado WarningCYSNiobrara44 min
Jul 7, 6:29 PM MDTSevere Thunderstorm WarningCYSLaramie61 min
Jul 7, 7:05 PM MDTSevere Thunderstorm WarningCYSKimball55 min
Jul 7, 7:50 PM MDTSevere Thunderstorm WarningCYSBox Butte40 min
Jul 7, 8:04 PM MDTSevere Thunderstorm WarningLBFGarden56 min
Jul 7, 8:41 PM MDTSevere Thunderstorm WarningLBFSheridan49 min
Jul 7, 9:02 PM MDTSevere Thunderstorm WarningLBFGarden58 min

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 10.8 hours before the alert went out and 189 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 2001-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 605 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, Rapid City, SD at 12:00Z on 2001-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 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
605 J/kg
Mixed-layer CIN
-232 J/kg
Mixed-layer LCL
1497 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
142 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

579 
WWUS9 KMKC 072231
SEL1  

SEL1  
MKC WW 072225
NEZ000-SDZ000-WYZ000-080400-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 521
STORM PREDICTION CENTER NORMAN OK
425 PM MDT SAT JUL 7 2001

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

   NEBRASKA PANHANDLE                          
   EXTREME SOUTHWESTERN SOUTH DAKOTA                       
   SOUTHEASTERN WYOMING                            

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 445 PM UNTIL
1000 PM MDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 85 STATUTE MILES
EITHER SIDE OF A LINE FROM 70 MILES WEST NORTHWEST OF SCOTTSBLUFF
NEBRASKA TO 40 MILES EAST NORTHEAST OF ALLIANCE NEBRASKA.

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.

DISCUSSION...THUNDERSTORMS DEVELOPING IN ERN WY ARE EXPECTED TO
MOVE EWD INTO AN ENVIRONMENT WITH MODERATE INSTABILITY AND
SUFFICIENT SHEAR FOR A FEW STORMS WITH LARGE HAIL AND DAMAGING
WINDS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550.  MEAN STORM
MOTION VECTOR 25020.

...IMY

432,1045 433,1020 410,1020 410,1045

Nearby

Severe Thunderstorm Watches in Nebraska, 2001Severe Thunderstorm Watches in Wyoming, 2001Severe Thunderstorm Watches in South Dakota, 2001Every severe thunderstorm watch in 2001

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.