Alert archive / South Dakota / Tornado Watches in 2001

Tornado Watch 484

June 30, 200114 counties in South Dakota; 7 counties in Wyoming

The Storm Prediction Center issued this tornado watch at Jun 30, 2001, 4:15 PM MDT for 14 counties in South Dakota; 7 counties in Wyoming. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jun 30, 2001, 4:15 PM MDT (22:15 UTC)
Expired: Jun 30, 2001, 10:00 PM MDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 21 counties

Bennett County, SD, Butte County, SD, Custer County, SD, Fall River County, SD, Haakon County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Meade County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Todd County, SD, Ziebach County, SD, Campbell County, WY, Converse County, WY, Crook County, WY, Johnson County, WY, Niobrara County, WY, Sheridan County, WY, Weston County, WY

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 30, 4:29 PM MDT	Severe Thunderstorm Warning	UNR	Custer, Pennington	61 min
Jun 30, 5:04 PM MDT	Severe Thunderstorm Warning	RIW	Johnson	41 min
Jun 30, 5:28 PM MDT	Severe Thunderstorm Warning	UNR	Custer	62 min
Jun 30, 6:09 PM MDT	Severe Thunderstorm Warning	UNR	Meade	66 min
Jun 30, 7:00 PM MDT	Severe Thunderstorm Warning	UNR	Pennington	60 min
Jun 30, 7:23 PM MDT	Severe Thunderstorm Warning	UNR	Lawrence	37 min

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 10.3 hours before the alert went out and 30 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: 584 J/kg
Mixed-layer CIN: -62 J/kg
Mixed-layer LCL: 975 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 84 m²/s²
0-3 km storm-relative helicity: 276 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 12.8

Open this sounding in Storm Lab

The text

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

000 
WWUS9 KMKC 302215
SEL4  

SEL4  
MKC WW 302207
SDZ000-WYZ000-010400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 484
STORM PREDICTION CENTER NORMAN OK
407 PM MDT SAT JUN 30 2001

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

   WESTERN AND SOUTHERN SOUTH DAKOTA                       
   EASTERN AND NORTHERN WYOMING                            

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 415 PM UNTIL
1000 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 160 STATUTE MILES EAST AND WEST
OF A LINE FROM 50 MILES NORTH NORTHEAST OF MOORCROFT WYOMING TO 75
MILES SOUTH OF RAPID CITY SOUTH DAKOTA.

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.

DISCUSSION...THUNDERSTORMS/SUPERCELLS EXPECTED TO INCREASE IN
COVERAGE OVER WATCH AREA THIS EVENING AS MOIST UPSLOPE FLOW
CONTINUES INVOF ENE/WSW-ORIENTED SURFACE TROUGH...AND LARGE SCALE
ASCENT INCREASES IN RESPONSE TO PASSAGE OF EXIT REGION ASSOCIATED
WITH SRN MANITOBA SPEED MAX.   CAPPING APPEARS TO BE LIMITING STORM
DEVELOPMENT ALONG SURFACE COLD FRONT NOW OVER NW SD/SE MT...BUT
THIS FEATURE MAY BE A FOCUS FOR STORM DEVELOPMENT AS IT CONTINUES
SWD LATER THIS EVENING.

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 500. 
MEAN STORM MOTION VECTOR 30025.

...CORFIDI

;445,1010 425,0995 425,1061 445,1074;

Nearby

Tornado Watches in South Dakota, 2001 Tornado Watches in Wyoming, 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.