Alert archive / South Dakota / Tornado Watches in 2001

Tornado Watch 437

June 17, 20014 states

The Storm Prediction Center issued this tornado watch at Jun 17, 2001, 4:00 PM CDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jun 17, 2001, 4:00 PM CDT (21:00 UTC)
Expired: Jun 17, 2001, 10:00 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 53 counties

Buena Vista County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Ida County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sac County, IA, Sioux County, IA, Woodbury County, IA, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Redwood County, MN, Rock County, MN, Yellow Medicine County, MN, Boyd County, NE, Cedar County, NE, Dixon County, NE, Knox County, NE, Aurora County, SD, Beadle County, SD, Bon Homme County, SD, Brookings County, SD, Charles Mix County, SD, Clark County, SD, Clay County, SD, Codington County, SD, Davison County, SD, Deuel County, SD, Douglas County, SD, Hamlin County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Spink County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 66 km from the middle of the area, began a volume at 21:04 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.

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 9.0 hours before the alert went out and 131 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1682 m above ground
0-6 km bulk shear: 62 kt
0-1 km storm-relative helicity: 69 m²/s²
0-3 km storm-relative helicity: 368 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.

267 
WWUS9 KMKC 172031
SEL7  

SEL7  
MKC WW 172021
IAZ000-MNZ000-NEZ000-SDZ000-180300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 437
STORM PREDICTION CENTER NORMAN OK
321 PM CDT SUN JUN 17 2001

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

   NORTHWEST IOWA                               
   SOUTHWEST MINNESOTA                          
   EXTREME NORTHEAST NEBRASKA                           
   EASTERN SOUTH DAKOTA                       

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 400 PM UNTIL 1000
PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 90 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 40 MILES SOUTHWEST OF HURON SOUTH DAKOTA TO 25
MILES NORTH NORTHEAST OF SPENCER IOWA.

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...AN ISOLATED SEVERE THUNDERSTORM IS MOVING ESEWD 35 KT
INTO EAST CENTRAL SOUTH DAKOTA...AND ADDITIONAL STORMS ARE EXPECTED
TO DEVELOP OVER SERN SD NEXT SEVERAL HOURS WHERE VISIBLE IMAGERY
SHOWS CU/TCU FIELD DEVELOPING NEAR WARM FRONT.  AIR MASS HAS BECOME
VERY UNSTABLE OVER NERN NEB AND SRN SD WITH MLCAPE OF 2500-3500
J/KG.  PROFILER AND VAD WINDS SHOW PRONOUNCED VEERING/INCREASE IN
SPEED WITH HEIGHT OF WINDS ALOFT...INDICATING THREAT FOR SUPERCELLS
THAT WILL MOVE EWD 30-35 KT.  SUFFICIENT MID LEVEL SR FLOW..STRONG
LOW LEVEL SHEAR AND RELATIVELY LOW LCL LEVELS SUGGEST POTENTIAL FOR
A FEW TORNADOES.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. 
MEAN STORM MOTION VECTOR 26035.


...WEISS

451,0984 444,0945 421,0945 424,0984

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 17, 5:30 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Appanoose, Clarke, Dallas, Davis and 23 more	6 hr

Nearby

Tornado Watches in South Dakota, 2001 Tornado Watches in Iowa, 2001 Tornado Watches in Minnesota, 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.