Alert archive / Nebraska / Tornado Watches in 2011

Tornado Watch 523

June 20, 201111 counties in Kansas; 40 counties in Nebraska

The Storm Prediction Center issued this tornado watch at Jun 20, 2011, 1:00 PM CDT for 11 counties in Kansas; 40 counties in Nebraska. It was in force for 10 hr.

The area

The outline as issued.

The facts

Issued
Jun 20, 2011, 1:00 PM CDT (18:00 UTC)
Expired
Jun 20, 2011, 10:33 PM CDT
In force
10 hr
Issued by
the Storm Prediction Center
Particularly dangerous situation
Yes
Largest hail expected
4 in
Strongest gust expected
70 kt
All 51 counties

Decatur County, KS, Gove County, KS, Graham County, KS, Jewell County, KS, Mitchell County, KS, Norton County, KS, Osborne County, KS, Phillips County, KS, Rooks County, KS, Sheridan County, KS, Smith County, KS, Adams County, NE, Antelope County, NE, Boone County, NE, Buffalo County, NE, Butler County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Custer County, NE, Dawson County, NE, Fillmore County, NE, Franklin County, NE, Furnas County, NE, Garfield County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Holt County, NE, Howard County, NE, Kearney County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nuckolls County, NE, Phelps County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Red Willow County, NE, Sherman County, NE, Stanton County, NE, Thayer County, NE, Valley County, NE, Wayne County, NE, Webster County, NE, Wheeler County, NE, York County, NE

The radar

The Grand Island radar (KUEX), 109 km from the middle of the area, began a volume at 17:56 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
90%
One or more EF2 to EF5 tornadoes
60%
Ten or more severe wind reports
80%
One or more gusts of 65 knots or more
60%
Ten or more severe hail reports
95%
One or more hailstones of 2 inches or more
95%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 20, 1:26 PM CDTTornado WarningGLDDecatur, Graham, Norton, Sheridan64 min
Jun 20, 2:03 PM CDTTornado WarningGLDGraham, Norton27 min
Jun 20, 2:20 PM CDTTornado WarningGIDPhillips40 min
Jun 20, 2:26 PM CDTTornado WarningGLDNorton34 min
Jun 20, 2:57 PM CDTTornado WarningGIDPhillips33 min
Jun 20, 2:57 PM CDTTornado WarningGLDNorton18 min
Jun 20, 3:02 PM CDTFlash Flood WarningGLDGove, Sheridan, Thomas6 hr
Jun 20, 3:23 PM CDTSevere Thunderstorm WarningGIDDawson, Gosper, Phelps52 min
Jun 20, 3:29 PM CDTTornado WarningGIDFurnas, Harlan, Phelps19 min
Jun 20, 3:29 PM CDTTornado WarningGIDBuffalo, Dawson, Gosper, Phelps31 min
Jun 20, 3:58 PM CDTTornado WarningGIDBuffalo, Dawson, Gosper, Phelps47 min
Jun 20, 4:03 PM CDTSevere Thunderstorm WarningGIDBuffalo, Sherman42 min
Jun 20, 4:21 PM CDTSevere Thunderstorm WarningGLDGove, Logan, Sheridan, Thomas35 min
Jun 20, 4:33 PM CDTTornado WarningGIDBuffalo, Sherman42 min
Jun 20, 4:40 PM CDTSevere Thunderstorm WarningGIDClay, Fillmore, Hall, Hamilton, Howard, Merrick and 1 more31 min
Jun 20, 4:46 PM CDTTornado WarningGIDBuffalo, Sherman44 min
Jun 20, 5:02 PM CDTTornado WarningGLDSheridan17 min
Jun 20, 5:05 PM CDTSevere Thunderstorm WarningGIDClay, Fillmore, Greeley, Hall, Hamilton, Howard and 4 more55 min
Jun 20, 5:08 PM CDTSevere Thunderstorm WarningGIDSherman, Valley52 min
Jun 20, 5:18 PM CDTSevere Thunderstorm WarningGLDDecatur, Sheridan42 min
Jun 20, 5:18 PM CDTTornado WarningGIDHamilton, York27 min
Jun 20, 5:25 PM CDTTornado WarningGIDGreeley, Howard, Sherman, Valley50 min
Jun 20, 5:27 PM CDTTornado WarningGLDSheridan63 min
Jun 20, 5:39 PM CDTTornado WarningGIDHamilton, Merrick, Polk, York36 min
Jun 20, 5:44 PM CDTTornado WarningGIDPolk, York31 min
Jun 20, 5:53 PM CDTSevere Thunderstorm WarningGIDGreeley, Hamilton, Howard, Merrick, Nance, Polk and 3 more52 min
Jun 20, 5:57 PM CDTTornado WarningGLDDecatur, Graham, Norton, Sheridan1 min
Jun 20, 6:00 PM CDTTornado WarningGLDDecatur60 min
Jun 20, 6:00 PM CDTTornado WarningGIDHamilton, Merrick, Polk, York45 min
Jun 20, 6:10 PM CDTSevere Thunderstorm WarningGLDRed Willow65 min
Jun 20, 6:15 PM CDTSevere Thunderstorm WarningLBFGarfield, Wheeler21 min
Jun 20, 6:22 PM CDTSevere Thunderstorm WarningOAXPlatte38 min
Jun 20, 6:25 PM CDTTornado WarningGLDDecatur, Norton65 min
Jun 20, 6:27 PM CDTSevere Thunderstorm WarningOAXAntelope48 min
Jun 20, 6:31 PM CDTSevere Thunderstorm WarningGIDFurnas44 min
Jun 20, 6:43 PM CDTSevere Thunderstorm WarningGIDMerrick, Nance, Polk17 min
Jun 20, 6:49 PM CDTTornado WarningGLDDecatur, Sheridan56 min
Jun 20, 6:51 PM CDTFlash Flood WarningGLDDecatur, Rawlins, Sheridan, Thomas6 hr
Jun 20, 6:57 PM CDTSevere Thunderstorm WarningOAXMadison, Platte63 min
Jun 20, 7:10 PM CDTTornado WarningGLDDecatur65 min
Jun 20, 7:11 PM CDTSevere Thunderstorm WarningGIDFurnas49 min
Jun 20, 7:13 PM CDTSevere Thunderstorm WarningOAXAntelope, Knox32 min
Jun 20, 7:17 PM CDTSevere Thunderstorm WarningGIDFillmore, York28 min
Jun 20, 7:27 PM CDTSevere Thunderstorm WarningOAXCedar, Knox, Madison, Pierce, Wayne48 min
Jun 20, 7:29 PM CDTTornado WarningOAXMadison, Platte31 min
Jun 20, 7:36 PM CDTTornado WarningGLDDecatur, Sheridan14 min
Jun 20, 7:36 PM CDTSevere Thunderstorm WarningGIDPolk, York39 min
Jun 20, 7:50 PM CDTSevere Thunderstorm WarningOAXCedar, Knox, Wayne40 min
Jun 20, 8:01 PM CDTSevere Thunderstorm WarningOAXBurt, Cuming, Dodge, Saunders, Thurston, Washington44 min
Jun 20, 8:11 PM CDTSevere Thunderstorm WarningGIDFurnas34 min
Jun 20, 8:15 PM CDTSevere Thunderstorm WarningGLDRed Willow21 min
Jun 20, 8:16 PM CDTFlash Flood WarningOAXMadison, Platte, Stanton3 hr
Jun 20, 8:27 PM CDTSevere Thunderstorm WarningOAXCedar, Thurston, Wayne33 min
Jun 20, 8:37 PM CDTSevere Thunderstorm WarningOAXBurt, Cuming, Thurston, Washington38 min
Jun 20, 9:12 PM CDTFlash Flood WarningOAXBurt, Cuming, Thurston2 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 6.0 hours before the alert went out and 153 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-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 12:00Z on 2011-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 163 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, N. Platte/Lee Bi, NE at 12:00Z on 2011-06-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 159 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
163 J/kg
Mixed-layer CIN
-253 J/kg
Mixed-layer LCL
570 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
159 m²/s²
0-3 km storm-relative helicity
34 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

295 
WWUS20 KWNS 201801
SEL3
SPC WW 201801
KSZ000-NEZ000-210100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 523
NWS STORM PREDICTION CENTER NORMAN OK
100 PM CDT MON JUN 20 2011

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

       PARTS OF NORTH CENTRAL KANSAS
       LARGE PART OF EASTERN NEBRASKA

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 100 PM UNTIL 800
PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 4 INCHES IN DIAMETER...
THUNDERSTORM WIND GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE
POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE
MILES EAST AND WEST OF A LINE FROM 50 MILES EAST NORTHEAST OF
ONEILL NEBRASKA TO 25 MILES SOUTH SOUTHEAST OF HILL CITY KANSAS.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU3).

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 522...

DISCUSSION...INTENSE SURFACE LOW OVER NCENTRAL KS WITH RAPID
DESTABILIZATION OCCURRING  INTO NEB WHERE SHEAR IS VERY FAVORABLE
FOR SUPERCELL DEVELOPMENT.  SUPERCELL THUNDERSTORMS WELL DEVELOP
AHEAD OF THE TRACK OF THE LOW WITH POTENTIAL FOR STRONG TORNADOES
INCREASING THRU THE AFTERNOON AS SYSTEM MOVES NNE.  VERY LARGE HAIL
ALSO LIKELY GIVEN MLCAPES AOA 2500 J/KG AND LARGE HODOGRAPHS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 22030.


...HALES

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 8:05 AM CDTMesoscale DiscussionSPCCheyenne, Decatur, Finney, Gove, Graham, Grant and 15 more55 min
Jun 20, 8:38 AM CDTSevere Thunderstorm WatchSPCDecatur, Ellis, Finney, Gove, Graham, Grant and 25 more6 hr
Jun 20, 10:42 AM CDTMesoscale DiscussionSPCAllen, Anderson, Butler, Chase, Chautauqua, Coffey and 18 more63 min
Jun 20, 12:22 PM CDTMesoscale DiscussionSPCDecatur, Gove, Graham, Logan, Norton, Phillips and 6 more83 min
Jun 20, 1:34 PM CDTMesoscale DiscussionSPCButler, Chase, Clay, Cowley, Dickinson, Ellsworth and 15 more116 min
Jun 20, 2:19 PM CDTMesoscale DiscussionSPCNorton, Phillips, Smith86 min
Jun 20, 2:52 PM CDTMesoscale DiscussionSPCDecatur, Rawlins, Thomas53 min
Jun 20, 3:08 PM CDTTornado WatchSPCAtchison, Brown, Butler, Chase, Chautauqua, Clay and 34 more7 hr
Jun 20, 3:59 PM CDTMesoscale DiscussionSPCJewell61 min
Jun 20, 6:17 PM CDTMesoscale DiscussionSPCBrown, Butler, Chase, Chautauqua, Clay, Coffey and 28 more58 min
Jun 19, 8:24 PM CDTMesoscale DiscussionSPCAdams, Blaine, Boone, Buffalo, Chase, Clay and 35 more96 min
Jun 19, 9:16 PM CDTMesoscale DiscussionSPCBurt, Cass, Dodge, Douglas, Lancaster, Nemaha and 4 more59 min
Jun 19, 9:49 PM CDTTornado WatchSPCAdams, Antelope, Boone, Buffalo, Burt, Butler and 46 more6 hr
Jun 20, 12:45 AM CDTSevere Thunderstorm WatchSPCChase, Dundy, Frontier, Hayes, Hitchcock, Red Willow2 hr
Jun 20, 3:27 AM CDTMesoscale DiscussionSPCBurt, Butler, Cass, Colfax, Cuming, Dodge and 11 more33 min
Jun 20, 3:46 AM CDTSevere Thunderstorm WatchSPCBurt, Butler, Cass, Colfax, Cuming, Dodge and 10 more5 hr
Jun 20, 6:53 PM CDTTornado WatchSPCAntelope, Boone, Boyd, Burt, Butler, Cass and 29 more6 hr

Nearby

Tornado Watches in Nebraska, 2011Tornado Watches in Kansas, 2011Every tornado watch in 2011

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.