Alert archive / Nebraska / Tornado Warnings in 2011
Tornado Warning 23, NWS Cheyenne, WY
NWS Cheyenne, WY issued this tornado warning at Jul 4, 2011, 4:45 PM MDT for Sioux County, Nebraska. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jul 4, 2011, 4:45 PM MDT (22:45 UTC)
- Expired
- Jul 4, 2011, 5:12 PM MDT
- In force
- 27 min
- Issued by
- NWS Cheyenne, WY
- Area
- Storm-based polygon
County Sioux County, NE
The radar
The Cheyenne radar (KCYS), 146 km from the middle of the area, began a volume at 22:46 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
Rapid City, SD (KUNR), launched 12:00Z, 10.8 hours before the alert went out and 224 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.
- Mixed-layer CAPE
- 1069 J/kg
- Mixed-layer CIN
- -380 J/kg
- Mixed-layer LCL
- 1605 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- -18 m²/s²
- 0-3 km storm-relative helicity
- 252 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.1
The text
As transmitted, in the capitals the NWS used until 2016.
564 WFUS55 KCYS 042245 TORCYS NEC165-042330- /O.NEW.KCYS.TO.W.0023.110704T2245Z-110704T2330Z/ BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE CHEYENNE WY 445 PM MDT MON JUL 4 2011 THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A * TORNADO WARNING FOR... SOUTH CENTRAL SIOUX COUNTY IN THE PANHANDLE OF NEBRASKA... * UNTIL 530 PM MDT * AT 441 PM MDT...TRAINED WEATHER SPOTTERS REPORTED A FUNNEL CLOUD 12 MILES NORTHEAST OF MORRILL...OR 19 MILES EAST OF TORRINGTON. A TORNADO MAY DEVELOP AT ANY TIME. DOPPLER RADAR SHOWED THIS DANGEROUS STORM MOVING EAST AT 10 MPH. * LOCATIONS IMPACTED INCLUDE... MAINLY RURAL AREAS OF SOUTHERN SIOUX COUNTY. PRECAUTIONARY/PREPAREDNESS ACTIONS... TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS. && LAT...LON 4221 10351 4201 10352 4207 10388 4220 10386 TIME...MOT...LOC 2246Z 276DEG 8KT 4212 10381 $$ MAZUR
1 follow-up statement
170 WWUS55 KCYS 042312 SVSCYS SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE CHEYENNE WY 512 PM MDT MON JUL 4 2011 NEC165-042319- /O.CAN.KCYS.TO.W.0023.000000T0000Z-110704T2330Z/ SIOUX NE- 512 PM MDT MON JUL 4 2011 ...THE TORNADO WARNING FOR SOUTH CENTRAL SIOUX COUNTY HAS BEEN REISSUED... THE TORNADO WARNING REMAINS IN EFFECT FOR SOUTHWESTERN SIOUX AND NORTH CENTRAL SCOTTS BLUFF COUNTIES UNTIL 530 PM. LAT...LON 4221 10351 4201 10352 4207 10388 4220 10386 TIME...MOT...LOC 2309Z 276DEG 8KT 4211 10374 $$ MAZUR
The office that day
Everything else NWS Cheyenne, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 4, 4:27 PM MDT | Severe Thunderstorm Warning | CYS | Kimball | 29 min |
| Jul 4, 4:35 PM MDT | Severe Thunderstorm Warning | CYS | Sioux | 12 min |
| Jul 4, 5:08 PM MDT | Tornado Warning | CYS | Scotts Bluff, Sioux | 37 min |
| Jul 4, 5:37 PM MDT | Tornado Warning | CYS | Banner, Scotts Bluff | 26 min |
| Jul 4, 5:41 PM MDT | Flash Flood Warning | CYS | Scotts Bluff, Sioux | 2 hr |
Nearby
Tornado Warnings in Nebraska, 2011Every tornado warning in 2011Tornadoes 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.