Alert archive / Wyoming / Tornado Warnings in 2017

Tornado Warning 7, NWS Cheyenne, WY

June 12, 2017Goshen County, Platte County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jun 12, 2017, 4:12 PM MDT for Goshen County, Platte County, Wyoming. It was in force for 33 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, 4:12 PM MDT (22:12 UTC)
Expired: Jun 12, 2017, 4:45 PM MDT
In force: 33 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 2.75 in

Counties Goshen County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 117 km from the middle of the area, began a volume at 22:13 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.

What was reported inside it

Time	Report	Where	Remark
Jun 12, 4:19 PM MDT	HAIL 2.5	Fort Laramie, WY
Jun 12, 4:25 PM MDT	HAIL 2.75	Fort Laramie, WY	TIME BASED ON RADAR.

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

Rapid City, SD (KRAP), launched 12:00Z, 10.2 hours before the alert went out and 248 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2300 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 168 m²/s²
0-3 km storm-relative helicity: 427 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted.

153 
WFUS55 KCYS 122212
TORCYS
WYC015-031-122245-
/O.NEW.KCYS.TO.W.0007.170612T2212Z-170612T2245Z/

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

The National Weather Service in Cheyenne has issued a

* Tornado Warning for...
  Northwestern Goshen County in southeastern Wyoming...
  Eastern Platte County in southeastern Wyoming...

* Until 445 PM MDT
    
* At 411 PM MDT, a severe thunderstorm capable of producing a tornado
  was located near Fort Laramie National Historic Site, or 19 miles
  northeast of Wheatland, moving northeast at 20 mph.

  HAZARD...Tornado and baseball 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 dangerous storm will be near...
  Fort Laramie National Historic Site around 425 PM MDT. 
  Fort Laramie around 430 PM MDT. 

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 4206 10457 4218 10472 4241 10448 4220 10425
TIME...MOT...LOC 2211Z 230DEG 16KT 4216 10461 

TORNADO...RADAR INDICATED
HAIL...2.75IN

$$

Levin

1 follow-up statement

754 
WWUS55 KCYS 122230
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
430 PM MDT MON JUN 12 2017

WYC031-122239-
/O.CAN.KCYS.TO.W.0007.000000T0000Z-170612T2245Z/
Platte WY-
430 PM MDT MON JUN 12 2017

...THE TORNADO WARNING FOR EASTERN PLATTE COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A tornado watch remains in effect until 800 PM MDT for southeastern
Wyoming.

LAT...LON 4212 10450 4224 10465 4241 10448 4220 10425
TIME...MOT...LOC 2229Z 230DEG 16KT 4221 10452 

$$

WYC015-122245-
/O.CON.KCYS.TO.W.0007.000000T0000Z-170612T2245Z/
Goshen WY-
430 PM MDT MON JUN 12 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM MDT FOR
NORTHWESTERN GOSHEN COUNTY...
    
At 429 PM MDT, a severe thunderstorm capable of producing a tornado
was located over Fort Laramie, or 20 miles northwest of Torrington,
moving northeast at 20 mph.

HAZARD...Tornado and softball 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
northwestern Goshen 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 4212 10450 4224 10465 4241 10448 4220 10425
TIME...MOT...LOC 2229Z 230DEG 16KT 4221 10452 

TORNADO...RADAR INDICATED
HAIL...4.00IN

$$

Levin

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, 4:15 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	45 min
Jun 12, 4:22 PM MDT	Tornado Warning	CYS	Laramie	23 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.