Alert archive / Nebraska / Tornado Watches in 1997

Tornado Watch 403

June 11, 199720 counties in Nebraska; 5 counties in South Dakota

The Storm Prediction Center issued this tornado watch at Jun 11, 1997, 3:30 PM CDT for 20 counties in Nebraska; 5 counties in South Dakota. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jun 11, 1997, 3:30 PM CDT (20:30 UTC)
Expired: Jun 11, 1997, 9:00 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 25 counties

Blaine County, NE, Boone County, NE, Boyd County, NE, Brown County, NE, Cherry County, NE, Custer County, NE, Garfield County, NE, Greeley County, NE, Holt County, NE, Howard County, NE, Keya Paha County, NE, Logan County, NE, Loup County, NE, Merrick County, NE, Nance County, NE, Rock County, NE, Sherman County, NE, Thomas County, NE, Valley County, NE, Wheeler County, NE, Bennett County, SD, Gregory County, SD, Mellette County, SD, Todd County, SD, Tripp County, SD

The radar

The North Platte radar (KLNX), 103 km from the middle of the area, began a volume at 20:29 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

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

Issued	Product	Office	Counties	Lasted
Jun 11, 3:35 PM CDT	Severe Thunderstorm Warning	LBF	Custer	45 min
Jun 11, 3:44 PM CDT	Severe Thunderstorm Warning	LBF	Keya Paha	61 min
Jun 11, 3:52 PM CDT	Severe Thunderstorm Warning	LBF	Blaine	33 min
Jun 11, 4:00 PM CDT	Severe Thunderstorm Warning	UNR	Mellette	45 min
Jun 11, 4:28 PM CDT	Severe Thunderstorm Warning	UNR	Todd	47 min
Jun 11, 5:15 PM CDT	Severe Thunderstorm Warning	LBF	Custer, Loup	50 min
Jun 11, 5:23 PM CDT	Severe Thunderstorm Warning	GID	Valley	52 min
Jun 11, 6:18 PM CDT	Severe Thunderstorm Warning	GID	Sherman, Valley	42 min
Jun 11, 6:23 PM CDT	Severe Thunderstorm Warning	LBF	Brown, Rock	62 min
Jun 11, 6:55 PM CDT	Tornado Warning	GID	Sherman	50 min
Jun 11, 7:33 PM CDT	Tornado Warning	GID	Howard	42 min
Jun 11, 7:47 PM CDT	Tornado Warning	GID	Sherman	28 min
Jun 11, 8:05 PM CDT	Severe Thunderstorm Warning	LBF	Holt	65 min
Jun 11, 8:18 PM CDT	Severe Thunderstorm Warning	GID	Howard	42 min

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 8.5 hours before the alert went out and 183 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: 270 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 578 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 279 m²/s²
0-3 km storm-relative helicity: 369 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

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

534 
WWUS9 KMKC 111956
SEL3  
MKC WW 111956
NEZ000-SDZ000-120200-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 403
STORM PREDICTION CENTER NORMAN OK
256 PM CDT WED JUN 11 1997

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

   CENTRAL NEBRASKA                           
   SOUTHERN SOUTH DAKOTA                       

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 330 PM UNTIL
900 PM CDT.

TORNADOES...HAIL TO 2 1/2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS ALONG AND 75 STATUTE MILES EAST AND WEST
OF A LINE FROM 55 MILES NORTH OF VALENTINE NEBRASKA TO 30 MILES
SOUTHEAST OF BROKEN BOW 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 402...

DISCUSSION...THUNDERSTORMS DEVELOPING RAPIDLY VICINITY
SURFACE/UPPER LOW NE/SD BORDER.  BEST MOISTURE CONVERGENCE ACROSS
NORTHCENTRAL NE WHERE STORMS SHOULD DEVELOP TOWARD.  SUFFICIENT
SHEAR AND MODERATE INSTABILITY FOR SUPERCELLS AND ISOLATED
TORNADOES.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 1/2 INCHES.  EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
520.  MEAN STORM MOTION VECTOR 26030.


...HALES

433,0990 410,0974 410,1003 433,1020

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 11, 5:00 PM CDT	Tornado Watch	SPC	Jefferson, Pawnee, Richardson	5 hr
Jun 11, 5:30 PM CDT	Tornado Watch	SPC	Adams, Buffalo, Dawson, Franklin, Frontier, Furnas and 8 more	4 hr

Nearby

Tornado Watches in Nebraska, 1997 Tornado Watches in South Dakota, 1997 Every tornado watch in 1997

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.