Alert archive / Wyoming / Tornado Warnings in 2018

Tornado Warning 34, NWS Cheyenne, WY

August 7, 2018Goshen County, Laramie County, Platte County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Aug 7, 2018, 8:13 PM MDT for Goshen County, Laramie County, Platte County, Wyoming. It was in force for 32 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 7, 2018, 8:13 PM MDT (02:13 UTC)
Expired: Aug 7, 2018, 8:45 PM MDT
In force: 32 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Goshen County, WY, Laramie County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 59 km from the middle of the area, began a volume at 02:13 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 00:00Z, 2.2 hours before the alert went out and 231 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: 1316 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 1934 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: -49 m²/s²
0-3 km storm-relative helicity: -27 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -3.3

Open this sounding in Storm Lab

The text

As transmitted.

295 
WFUS55 KCYS 080213
TORCYS
WYC015-021-031-080245-
/O.NEW.KCYS.TO.W.0034.180808T0213Z-180808T0245Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Cheyenne WY
813 PM MDT TUE AUG 7 2018

The National Weather Service in Cheyenne has issued a

* Tornado Warning for...
  Southwestern Goshen County in southeastern Wyoming...
  Northern Laramie County in southeastern Wyoming...
  Southeastern Platte County in southeastern Wyoming...

* Until 845 PM MDT.
    
* At 813 PM MDT, a severe thunderstorm capable of producing a tornado
  was located near Chugwater, or 27 miles southeast of Wheatland,
  moving southeast at 25 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
  southwestern Goshen...northern Laramie and southeastern Platte
  Counties.

This includes Interstate 25 in Wyoming between mile markers 49 and
50.
 
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 4161 10461 4165 10465 4167 10484 4180 10478
      4171 10433 4156 10449
TIME...MOT...LOC 0213Z 292DEG 22KT 4169 10473 

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

$$

Braun

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 7, 7:01 PM MDT	Special Weather Statement	CYS	Platte	29 min
Aug 7, 7:33 PM MDT	Special Weather Statement	CYS	Platte	42 min
Aug 7, 7:55 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Platte	35 min
Aug 7, 8:27 PM MDT	Tornado Warning	CYS	Goshen, Laramie, Platte	33 min
Aug 7, 8:28 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Platte	32 min
Aug 7, 8:45 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Laramie	30 min
Aug 7, 9:08 PM MDT	Special Weather Statement	CYS	Goshen	52 min
Aug 7, 9:14 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	31 min
Aug 7, 9:41 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	34 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.