Alert archive / Wyoming / Tornado Watches in 2001

Tornado Watch 507

July 4, 20017 counties in Nebraska; 6 counties in South Dakota; 10 counties in Wyoming

The Storm Prediction Center issued this tornado watch at Jul 4, 2001, 2:15 PM MDT for 7 counties in Nebraska; 6 counties in South Dakota; 10 counties in Wyoming. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jul 4, 2001, 2:15 PM MDT (20:15 UTC)
Expired: Jul 4, 2001, 9:00 PM MDT
In force: 7 hr
Issued by: the Storm Prediction Center

All 23 counties

Box Butte County, NE, Dawes County, NE, Grant County, NE, Morrill County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Butte County, SD, Custer County, SD, Fall River County, SD, Lawrence County, SD, Oglala Lakota County, SD, Pennington County, SD, Albany County, WY, Campbell County, WY, Converse County, WY, Crook County, WY, Goshen County, WY, Johnson County, WY, Niobrara County, WY, Platte County, WY, Sheridan County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 127 km from the middle of the area, began a volume at 20:15 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 4, 2:30 PM MDT	Severe Thunderstorm Warning	RIW	Johnson	30 min
Jul 4, 2:43 PM MDT	Tornado Warning	RIW	Johnson	32 min
Jul 4, 3:15 PM MDT	Severe Thunderstorm Warning	RIW	Johnson	30 min
Jul 4, 3:45 PM MDT	Severe Thunderstorm Warning	RIW	Johnson	30 min
Jul 4, 4:31 PM MDT	Severe Thunderstorm Warning	BYZ	Sheridan	44 min
Jul 4, 4:37 PM MDT	Severe Thunderstorm Warning	CYS	Converse	38 min
Jul 4, 4:57 PM MDT	Severe Thunderstorm Warning	UNR	Campbell	63 min
Jul 4, 5:06 PM MDT	Severe Thunderstorm Warning	RIW	Johnson	29 min
Jul 4, 5:15 PM MDT	Severe Thunderstorm Warning	CYS	Converse	45 min
Jul 4, 5:25 PM MDT	Severe Thunderstorm Warning	LBF	Sheridan	35 min
Jul 4, 5:36 PM MDT	Severe Thunderstorm Warning	CYS	Sioux	24 min
Jul 4, 5:42 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte	48 min
Jul 4, 5:59 PM MDT	Severe Thunderstorm Warning	CYS	Converse	46 min
Jul 4, 6:02 PM MDT	Severe Thunderstorm Warning	CYS	Scotts Bluff, Sioux	28 min
Jul 4, 6:29 PM MDT	Tornado Warning	CYS	Scotts Bluff, Sioux	31 min
Jul 4, 6:58 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Scotts Bluff	32 min
Jul 4, 8:14 PM MDT	Severe Thunderstorm Warning	UNR	Fall River	31 min
Jul 4, 8:48 PM MDT	Severe Thunderstorm Warning	CYS	Sioux	42 min

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 8.3 hours before the alert went out and 121 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 360 J/kg
Mixed-layer CIN: -142 J/kg
Mixed-layer LCL: 1094 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: -65 m²/s²
0-3 km storm-relative helicity: 62 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -1.0

Open this sounding in Storm Lab

The text

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

296 
WWUS9 KMKC 042009
SEL7  

SEL7  
MKC WW 042002
NEZ000-SDZ000-WYZ000-050300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 507
STORM PREDICTION CENTER NORMAN OK
202 PM MDT WED JUL 4 2001

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   THE NEBRASKA PANHANDLE                           
   WESTERN SOUTH DAKOTA                       
   EASTERN WYOMING                            

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 215 PM UNTIL
900 PM MDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 115 STATUTE MILES EAST AND WEST
OF A LINE FROM 45 MILES NORTH OF GILLETTE WYOMING TO 15 MILES SOUTH
OF SCOTTSBLUFF NEBRASKA.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

OTHER WATCH INFORMATION...  CONTINUE...WW 503...WW 504...WW
505...WW 506...

DISCUSSION...SUPERCELLS EXPECTED TO DEVELOP AND MOVE SEWD FROM THE
BIG HORNS AND PERHAPS THE BLACK HILLS LATER TODAY AS UPPER
SHORTWAVE DROPS SE ACROSS REGION.  THE SEVERE WEATHER...INCLUDING
LARGE HAIL/HIGH WINDS AND POSSIBLE TORNADOES...SHOULD BE MOST
CONCENTRATED ALONG LOW LEVEL CONFLUENCE AXIS EXTENDING FROM
VICINITY OF SHR/CPR TO NEAR BFF.  

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. 
MEAN STORM MOTION VECTOR 31020.

...CORFIDI

445,1031 413,1012 413,1054 445,1075

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 4, 5:15 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Brown, Buffalo, Cherry, Custer, Dawson and 11 more	6 hr

Nearby

Tornado Watches in Wyoming, 2001 Tornado Watches in Nebraska, 2001 Tornado Watches in South Dakota, 2001 Every tornado 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; radar from the NEXRAD Level II archive.