Alert archive / Wyoming / Tornado Warnings in 2018

Tornado Warning 17, NWS Cheyenne, WY

June 19, 2018Platte County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jun 19, 2018, 2:30 PM MDT for Platte County, Wyoming. It was in force for 17 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: Jun 19, 2018, 2:30 PM MDT (20:30 UTC)
Expired: Jun 19, 2018, 2:47 PM MDT
In force: 17 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Tornado: Observed
Hail: 1.0 in

County Platte County, WY

The radar

The Cheyenne radar (KCYS), 73 km from the middle of the area, began a volume at 20:32 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

Denver, CO (KDEN), launched 12:00Z, 8.5 hours before the alert went out and 258 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: 30 J/kg
Mixed-layer CIN: -220 J/kg
Mixed-layer LCL: 836 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 73 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

517 
WFUS55 KCYS 192030
TORCYS
WYC031-192100-
/O.NEW.KCYS.TO.W.0017.180619T2030Z-180619T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Cheyenne WY
230 PM MDT TUE JUN 19 2018

The National Weather Service in Cheyenne has issued a

* Tornado Warning for...
  Southeastern Platte County in southeastern Wyoming...

* Until 300 PM MDT.

* At 230 PM MDT, a confirmed tornado was located 8 miles southwest of
  Bordeaux, or 15 miles south of Wheatland, moving east at 35 mph.

  HAZARD...Damaging tornado and quarter size hail.

  SOURCE...Law enforcement confirmed tornado.

  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.

* The tornado will be near...
  Slater around 235 PM MDT.
  Chugwater around 250 PM MDT.

This includes Interstate 25 in Wyoming between mile markers 51 and
70.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. 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.

&&

LAT...LON 4173 10511 4192 10512 4195 10466 4168 10466
TIME...MOT...LOC 2030Z 270DEG 29KT 4184 10501 

TORNADO...OBSERVED
HAIL...1.00IN

$$

Cox

1 follow-up statement

155 
WWUS55 KCYS 192047
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
247 PM MDT TUE JUN 19 2018

WYC031-192057-
/O.CAN.KCYS.TO.W.0017.000000T0000Z-180619T2100Z/
Platte WY-
247 PM MDT TUE JUN 19 2018

...THE TORNADO WARNING FOR SOUTHEASTERN PLATTE COUNTY 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 small hail, gusty
winds and heavy rain are still possible with this thunderstorm.

LAT...LON 4173 10511 4192 10512 4195 10466 4168 10466
TIME...MOT...LOC 2046Z 270DEG 29KT 4184 10483 

$$

Cox

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 18, 6:33 PM MDT	Special Weather Statement	CYS	Goshen	42 min
Jun 18, 6:44 PM MDT	Special Weather Statement	CYS	Converse	46 min
Jun 18, 6:48 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Laramie	42 min
Jun 18, 7:30 PM MDT	Special Weather Statement	CYS	Laramie	45 min
Jun 19, 4:20 AM MDT	Special Weather Statement	CYS	Niobrara	40 min
Jun 19, 5:22 AM MDT	Special Weather Statement	CYS		38 min
Jun 19, 7:17 AM MDT	Special Weather Statement	CYS		43 min
Jun 19, 7:40 AM MDT	Special Weather Statement	CYS	Niobrara	35 min
Jun 19, 7:44 AM MDT	Special Weather Statement	CYS	Converse	46 min
Jun 19, 8:14 AM MDT	Special Weather Statement	CYS	Niobrara	46 min
Jun 19, 8:27 AM MDT	Special Weather Statement	CYS	Converse	48 min
Jun 19, 9:17 AM MDT	Special Weather Statement	CYS	Niobrara	43 min
Jun 19, 11:42 AM MDT	Special Weather Statement	CYS		48 min
Jun 19, 12:00 PM MDT	Severe Thunderstorm Warning	CYS	Carbon	45 min
Jun 19, 12:52 PM MDT	Special Weather Statement	CYS	Albany	53 min
Jun 19, 12:58 PM MDT	Special Weather Statement	CYS		47 min
Jun 19, 1:03 PM MDT	Special Weather Statement	CYS	Laramie	42 min
Jun 19, 1:10 PM MDT	Special Weather Statement	CYS	Platte	50 min
Jun 19, 1:24 PM MDT	Severe Thunderstorm Warning	CYS	Laramie, Platte	34 min
Jun 19, 1:38 PM MDT	Tornado Warning	CYS	Albany	37 min
Jun 19, 2:01 PM MDT	Tornado Warning	CYS	Albany, Laramie, Platte	44 min
Jun 19, 2:42 PM MDT	Tornado Warning	CYS	Goshen, Laramie, Platte	48 min
Jun 19, 3:20 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	40 min
Jun 19, 3:29 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	61 min
Jun 19, 3:41 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	49 min
Jun 19, 4:07 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	38 min
Jun 19, 4:38 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	52 min

Nearby

Tornado Warnings in Wyoming, 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.