Alert archive / Wyoming / Tornado Warnings in 2017

Tornado Warning 8, NWS Cheyenne, WY

June 12, 2017Laramie County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jun 12, 2017, 4:22 PM MDT for Laramie County, Wyoming. It was in force for 23 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jun 12, 2017, 4:22 PM MDT (22:22 UTC)
Expired: Jun 12, 2017, 4:45 PM MDT
In force: 23 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.75 in

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 20 km from the middle of the area, began a volume at 22:22 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.

What was reported inside it

Time	Report	Where	Remark
Jun 12, 4:40 PM MDT	TORNADO	11 Ne Cheyenne, WY	CONFIRMED TORNADO ON THE GROUND.
Jun 12, 4:40 PM MDT	TORNADO	11 Ne Cheyenne, WY	CONFIRMED TORNADO ON THE GROUND. TWO HOMES DAMAGED ON COUNTY RD 222. IRRIGATION PIVOT FLIPPED. PINE TREE UPROOTED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

Issued	Product	Office	Lasted
Jun 12, 1:11 PM MDT	Tornado Watch PDS	SPC	8 hr

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 10.4 hours before the alert went out and 194 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: 697 J/kg
Mixed-layer CIN: -160 J/kg
Mixed-layer LCL: 1130 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: 153 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

403 
WFUS55 KCYS 122222
TORCYS
WYC021-122245-
/O.NEW.KCYS.TO.W.0008.170612T2222Z-170612T2245Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Cheyenne WY
422 PM MDT MON JUN 12 2017

The National Weather Service in Cheyenne has issued a

* Tornado Warning for...
  Central Laramie County in southeastern Wyoming...

* Until 445 PM MDT
    
* At 422 PM MDT, a severe thunderstorm capable of producing a tornado
  was located near Ranchettes, or 9 miles northeast of Cheyenne,
  moving northeast at 20 mph.

  HAZARD...Tornado and golf ball 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
  central Laramie County.

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.

&&

LAT...LON 4117 10468 4121 10475 4144 10461 4130 10437
TIME...MOT...LOC 2222Z 220DEG 19KT 4125 10468 

TORNADO...RADAR INDICATED
HAIL...1.75IN

$$

Hammer

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 11, 7:26 PM MDT	Special Weather Statement	CYS	Converse	49 min
Jun 11, 9:19 PM MDT	Severe Thunderstorm Warning	CYS	Converse	26 min
Jun 12, 3:50 AM MDT	High Wind Watch	CYS	Albany, Carbon	23 hr
Jun 12, 2:05 PM MDT	Severe Thunderstorm Warning	CYS	Platte	25 min
Jun 12, 2:28 PM MDT	Severe Thunderstorm Warning	CYS	Albany, Platte	47 min
Jun 12, 2:55 PM MDT	Tornado Warning	CYS	Platte	35 min
Jun 12, 3:10 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	65 min
Jun 12, 3:11 PM MDT	Severe Thunderstorm Warning	CYS	Albany, Converse, Platte	34 min
Jun 12, 3:26 PM MDT	Tornado Warning	CYS	Goshen, Platte	34 min
Jun 12, 3:36 PM MDT	Severe Thunderstorm Warning	CYS	Albany, Converse	27 min
Jun 12, 3:40 PM MDT	Severe Thunderstorm Warning	CYS	Converse, Platte	34 min
Jun 12, 3:52 PM MDT	Tornado Warning	CYS	Goshen, Platte	23 min
Jun 12, 4:12 PM MDT	Tornado Warning	CYS	Goshen, Platte	33 min
Jun 12, 4:15 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	45 min
Jun 12, 4:26 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	34 min
Jun 12, 4:34 PM MDT	Tornado Warning	CYS	Laramie	41 min
Jun 12, 4:41 PM MDT	Tornado Warning	CYS	Goshen	34 min
Jun 12, 4:45 PM MDT	Tornado Warning Tornado observed	CYS	Laramie	20 min
Jun 12, 4:51 PM MDT	Tornado Warning Tornado observed	CYS	Laramie	39 min
Jun 12, 5:03 PM MDT	Severe Thunderstorm Warning	CYS	Converse, Platte	42 min
Jun 12, 5:09 PM MDT	Tornado Warning	CYS	Laramie	36 min
Jun 12, 5:12 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Niobrara	48 min
Jun 12, 5:15 PM MDT	Tornado Warning	CYS	Goshen, Laramie	30 min
Jun 12, 5:21 PM MDT	Tornado Warning	CYS	Laramie	39 min
Jun 12, 5:34 PM MDT	Tornado Warning Tornado observed	CYS	Goshen, Niobrara	41 min
Jun 12, 5:39 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Laramie	36 min
Jun 12, 5:42 PM MDT	Tornado Warning	CYS	Goshen	33 min
Jun 12, 5:52 PM MDT	Tornado Warning	CYS	Goshen, Laramie	38 min

Nearby

Tornado Warnings in Wyoming, 2017 Every tornado warning in 2017 Tornadoes in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.