Alert archive / Nebraska / Tornado Warnings in 2018

Tornado Warning 11, NWS Cheyenne, WY

May 27, 2018Box Butte County, Dawes County, Nebraska

NWS Cheyenne, WY issued this tornado warning at May 27, 2018, 7:18 PM MDT for Box Butte County, Dawes County, Nebraska. It was in force for 26 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: May 27, 2018, 7:18 PM MDT (01:18 UTC)
Expired: May 27, 2018, 7:44 PM MDT
In force: 26 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Box Butte County, NE, Dawes County, NE

The radar

The Rapid City radar (KUDX), 187 km from the middle of the area, began a volume at 01:18 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
May 27, 12:05 PM MDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Rapid City, SD (KRAP), launched 00:00Z, 1.3 hours before the alert went out and 181 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: 757 J/kg
Mixed-layer CIN: -156 J/kg
Mixed-layer LCL: 1692 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 345 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 8.8

Open this sounding in Storm Lab

The text

As transmitted.

130 
WFUS55 KCYS 280118
TORCYS
NEC013-045-280200-
/O.NEW.KCYS.TO.W.0011.180528T0118Z-180528T0200Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Cheyenne WY
718 PM MDT SUN MAY 27 2018

The National Weather Service in Cheyenne has issued a

* Tornado Warning for...
  North central Box Butte County in the Panhandle of Nebraska...
  South central Dawes County in the Panhandle of Nebraska...

* Until 800 PM MDT
    
* At 718 PM MDT, a severe thunderstorm capable of producing a tornado
  was located near Box Butte Campground, or 27 miles south of
  Chadron, moving north at 15 mph.

  HAZARD...Tornado and quarter size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This tornadic thunderstorm will remain over mainly rural areas of
  north central Box Butte and south central Dawes Counties, including
  the following locations: Marsland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4242 10301 4239 10307 4236 10320 4252 10339
      4261 10313
TIME...MOT...LOC 0118Z 161DEG 11KT 4246 10318 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Allen

1 follow-up statement

349 
WWUS55 KCYS 280144
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
744 PM MDT SUN MAY 27 2018

NEC013-045-280153-
/O.CAN.KCYS.TO.W.0011.000000T0000Z-180528T0200Z/
Box Butte NE-Dawes NE-
744 PM MDT SUN MAY 27 2018

...THE TORNADO WARNING FOR NORTH CENTRAL BOX BUTTE AND SOUTH CENTRAL
DAWES COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore the warning has been cancelled.  However heavy rain is
still possible with this thunderstorm.

A severe thunderstorm watch remains in effect until 800 PM MDT for
the Panhandle of Nebraska.

Remember, a Severe Thunderstorm Warning still remains in effect for
portions of Dawes County. 

LAT...LON 4242 10301 4239 10307 4236 10320 4252 10339
      4261 10313
TIME...MOT...LOC 0141Z 161DEG 11KT 4253 10321 

$$

Allen

The office that day

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

Issued	Product	Office	Counties	Lasted
May 27, 6:22 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Cheyenne, Kimball, Morrill	38 min
May 27, 6:40 PM MDT	Severe Thunderstorm Warning	CYS	Sioux	50 min
May 27, 6:46 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Box Butte, Morrill, Scotts Bluff, Sioux	44 min
May 27, 7:04 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes, Sioux	56 min
May 27, 7:26 PM MDT	Areal Flood Warning	CYS	Scotts Bluff, Sioux	6 hr
May 27, 8:03 PM MDT	Special Weather Statement	CYS	Dawes	57 min
May 28, 1:07 AM MDT	Areal Flood Advisory	CYS	Cheyenne	3 hr
May 28, 2:36 AM MDT	Flash Flood Watch	CYS	Banner, Box Butte, Cheyenne, Dawes, Kimball, Morrill and 2 more	24 hr
May 28, 5:39 PM MDT	Severe Thunderstorm Warning	CYS	Kimball	66 min

Nearby

Tornado Warnings in Nebraska, 2018 Every tornado warning in 2018 Tornadoes in 2018

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.