Alert archive / Nebraska / Tornado Watches in 2002

Tornado Watch 412

June 11, 20024 states

The Storm Prediction Center issued this tornado watch at Jun 11, 2002, 5:45 PM CDT for 4 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jun 11, 2002, 5:45 PM CDT (22:45 UTC)
Expired: Jun 11, 2002, 11:00 PM CDT
In force: 5 hr
Issued by: the Storm Prediction Center

All 44 counties

Crawford County, IA, Fremont County, IA, Harrison County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Shelby County, IA, Cloud County, KS, Marshall County, KS, Nemaha County, KS, Republic County, KS, Washington County, KS, Atchison County, MO, Holt County, MO, Burt County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Colfax County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Hamilton County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Nuckolls County, NE, Otoe County, NE, Pawnee County, NE, Platte County, NE, Polk County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thayer County, NE, Washington County, NE, York County, NE

The radar

The Omaha radar (KOAX), 66 km from the middle of the area, began a volume at 22:47 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

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

Issued	Product	Office	Counties	Lasted
Jun 11, 7:27 PM CDT	Severe Thunderstorm Warning	OAX	Jefferson	33 min
Jun 11, 7:48 PM CDT	Severe Thunderstorm Warning	OAX	Gage	27 min
Jun 11, 8:14 PM CDT	Severe Thunderstorm Warning	OAX	Gage	31 min

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 10.8 hours before the alert went out and 236 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: 2011 J/kg
Mixed-layer CIN: -155 J/kg
Mixed-layer LCL: 733 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 272 m²/s²
0-3 km storm-relative helicity: 377 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 13.4

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 112237
SEL2  
SPC WW 112231
IAZ000-KSZ000-NEZ000-120400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 412
STORM PREDICTION CENTER NORMAN OK
531 PM CDT TUE JUN 11 2002

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

   WESTERN IOWA                               
   FAR NORTHERN KANSAS                             
   EASTERN AND SOUTHERN NEBRASKA                           

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 545 PM UNTIL 1100
PM CDT.

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

THE TORNADO WATCH AREA IS ALONG AND 75 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 65 MILES NORTH NORTHWEST OF CONCORDIA KANSAS
TO 45 MILES EAST SOUTHEAST OF OMAHA 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 410...WW 411...

DISCUSSION...THUNDERSTORMS/SUPERCELLS EXPECTED TO SPREAD NWD INTO
WW FROM NRN KS.  OTHER STORMS EXPECTED TO INITIATE IN WW AREA LATER
THIS EVENING AS CONVERGENCE/SURFACE HEATING FURTHER DESTABILIZE
REGION.  DEEP SHEAR ALREADY SUPPORTIVE OF SUPERCELLS EXPECTED TO
STRENGTHEN THIS EVENING /PER RECENT UPSTREAM PROFILER TRENDS/. 
COUPLED WITH RICH BOUNDARY LAYER MOISTURE AND LIGHT AND VARIABLE
NEAR-SURFACE FLOW...POTENTIAL WILL EXIST FOR LOW LEVEL STORM
ROTATION/POSSIBLE TORNADOES.

AVIATION...TORNADOES AND 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 27035.

...CORFIDI

395,0950 391,0980 412,0980 420,0950

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 10, 9:30 PM CDT	Severe Thunderstorm Watch	SPC	Audubon, Buena Vista, Calhoun, Carroll, Cass, Cherokee and 18 more	5 hr
Jun 11, 1:30 AM CDT	Severe Thunderstorm Watch	SPC	Allamakee, Black Hawk, Bremer, Chickasaw, Clayton, Fayette and 5 more	6 hr
Jun 11, 3:45 PM CDT	Tornado Watch	SPC	Anderson, Atchison, Barton, Brown, Chase, Clark and 33 more	6 hr
Jun 11, 5:15 PM CDT	Tornado Watch	SPC	Doniphan, Johnson, Leavenworth, Miami, Wyandotte	6 hr

Nearby

Tornado Watches in Nebraska, 2002 Tornado Watches in Iowa, 2002 Tornado Watches in Kansas, 2002 Every tornado watch in 2002

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.