Alert archive / Nebraska / Tornado Warnings in 2011

Tornado Warning 32, NWS Cheyenne, WY

August 9, 2011Cheyenne County, Nebraska

NWS Cheyenne, WY issued this tornado warning at Aug 9, 2011, 2:47 PM MDT for Cheyenne County, Nebraska. It was in force for 16 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: Aug 9, 2011, 2:47 PM MDT (20:47 UTC)
Expired: Aug 9, 2011, 3:03 PM MDT
In force: 16 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon

County Cheyenne County, NE

The radar

The Cheyenne radar (KCYS), 169 km from the middle of the area, began a volume at 20:49 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 9, 1:51 PM MDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 8.8 hours before the alert went out and 137 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: 245 J/kg
Mixed-layer CIN: -295 J/kg
Mixed-layer LCL: 1813 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 91 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.

501 
WFUS55 KCYS 092047
TORCYS
NEC033-092115-
/O.NEW.KCYS.TO.W.0032.110809T2047Z-110809T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
247 PM MDT TUE AUG 9 2011

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN CHEYENNE COUNTY IN THE PANHANDLE OF NEBRASKA...

* UNTIL 315 PM MDT

* AT 245 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR SIDNEY AIRPORT...OR 5 MILES SOUTHEAST OF
  SIDNEY...AND MOVING SOUTH AT 15 MPH.

* LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF SOUTHERN CHEYENNE COUNTY.

THIS INCLUDES INTERSTATE 80 IN NEBRASKA BETWEEN MILE MARKERS 52 AND
77.

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 4105 10261 4100 10261 4099 10263 4100 10282
      4099 10283 4100 10310 4106 10316 4122 10307
      4121 10264 4105 10260
TIME...MOT...LOC 2047Z 338DEG 11KT 4106 10292

$$

GRIFFITH

1 follow-up statement

235 
WWUS55 KCYS 092103
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
303 PM MDT TUE AUG 9 2011

NEC033-092113-
/O.CAN.KCYS.TO.W.0032.000000T0000Z-110809T2115Z/
CHEYENNE NE-
303 PM MDT TUE AUG 9 2011

...THE TORNADO WARNING FOR SOUTHEASTERN CHEYENNE COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA.

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL 9 PM.

LAT...LON 4105 10261 4100 10261 4099 10263 4100 10282
      4099 10283 4100 10310 4106 10316 4122 10307
      4121 10264 4105 10260
TIME...MOT...LOC 2103Z 338DEG 11KT 4101 10290

$$

GRIFFITH

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 8, 6:09 PM MDT	Special Weather Statement	CYS	Morrill	51 min
Aug 8, 7:06 PM MDT	Special Weather Statement	CYS	Box Butte	24 min
Aug 9, 8:55 AM MDT	Severe Thunderstorm Warning	CYS	Morrill	26 min
Aug 9, 9:48 AM MDT	Special Weather Statement	CYS	Dawes	57 min
Aug 9, 10:41 AM MDT	Special Weather Statement	CYS	Box Butte	49 min
Aug 9, 2:16 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne	10 min
Aug 9, 2:24 PM MDT	Tornado Warning	CYS	Cheyenne	36 min

Nearby

Tornado Warnings in Nebraska, 2011 Every tornado warning in 2011 Tornadoes 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.