Alert archive / Wyoming / Tornado Warnings in 2023

Tornado Warning 39, NWS Cheyenne, WY

June 29, 2023Laramie County, Platte County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jun 29, 2023, 3:22 PM MDT for Laramie County, Platte County, Wyoming. It was in force for 23 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 29, 2023, 3:22 PM MDT (21:22 UTC)
Expired
Jun 29, 2023, 3:45 PM MDT
In force
23 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.5 in

Counties Laramie County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 44 km from the middle of the area, began a volume at 21:23 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.

IssuedProductOfficeLasted
Jun 29, 1:17 PM MDTTornado WatchSPC8 hr

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 9.4 hours before the alert went out and 329 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-pSkew-T log-p diagram, Riverton, WY at 12:00Z on 2023-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 51 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2023-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
51 J/kg
Mixed-layer CIN
-125 J/kg
Mixed-layer LCL
1483 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

580 
WFUS55 KCYS 292122
TORCYS
WYC021-031-292145-
/O.NEW.KCYS.TO.W.0039.230629T2122Z-230629T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Cheyenne WY
322 PM MDT Thu Jun 29 2023

The National Weather Service in Cheyenne has issued a

* Tornado Warning for...
  Northwestern Laramie County in southeastern Wyoming...
  South central Platte County in southeastern Wyoming...

* Until 345 PM MDT.
    
* At 322 PM MDT, a severe thunderstorm capable of producing a tornado
  was located 8 miles east of Iron Mountain, or 28 miles northwest of
  Cheyenne, moving northeast at 20 mph.

  HAZARD...Tornado and ping pong 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
  northwestern Laramie and south central Platte Counties.

This includes Interstate 25 in Wyoming between mile markers 34 and
44.
 
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 4145 10505 4155 10514 4171 10494 4148 10472
TIME...MOT...LOC 2122Z 237DEG 17KT 4152 10505 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.50 IN

$$

Rubin
2 follow-up statements
185 
WWUS55 KCYS 292132
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
332 PM MDT Thu Jun 29 2023

WYC021-031-292145-
/O.CON.KCYS.TO.W.0039.000000T0000Z-230629T2145Z/
Laramie WY-Platte WY-
332 PM MDT Thu Jun 29 2023

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 345 PM MDT FOR
NORTHWESTERN LARAMIE AND SOUTH CENTRAL PLATTE COUNTIES...
    
At 331 PM MDT, a severe thunderstorm capable of producing a tornado
was located 11 miles east of Iron Mountain, or 29 miles north of
Cheyenne, moving northeast at 20 mph.

HAZARD...Tornado and ping pong 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
northwestern Laramie and south central Platte Counties.

This includes Interstate 25 in Wyoming between mile markers 34 and
44.
 
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.

Motorists should not take shelter under highway overpasses. If you
cannot safely drive away from the tornado, as a last resort, either
park your vehicle and stay put, or abandon your vehicle and lie down
in a low lying area and protect yourself from flying debris.

&&

LAT...LON 4145 10500 4159 10509 4171 10494 4148 10472
TIME...MOT...LOC 2131Z 237DEG 17KT 4155 10500 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.50 IN

$$

Rubin
368 
WWUS55 KCYS 292144
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
344 PM MDT Thu Jun 29 2023

WYC021-031-292151-
/O.EXP.KCYS.TO.W.0039.000000T0000Z-230629T2145Z/
Laramie WY-Platte WY-
344 PM MDT Thu Jun 29 2023

...THE TORNADO WARNING FOR NORTHWESTERN LARAMIE AND SOUTH CENTRAL
PLATTE COUNTIES WILL EXPIRE AT 345 PM MDT...
    
The tornado threat has diminished and the Tornado Warning has been
cancelled. However, large hail and damaging winds remain likely and 
a Severe Thunderstorm Warning remains in effect for northwestern 
Laramie County and Southeastern Platte County until 415 PM MDT.

A Tornado Watch remains in effect until 900 PM MDT for southeastern
Wyoming.

LAT...LON 4145 10500 4159 10509 4171 10494 4148 10472
TIME...MOT...LOC 2141Z 237DEG 17KT 4157 10495 

$$

Rubin

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 28, 6:20 PM MDTSevere Thunderstorm WarningCYSLaramie40 min
Jun 28, 6:46 PM MDTSevere Thunderstorm WarningCYSLaramie59 min
Jun 28, 7:17 PM MDTSpecial Weather StatementCYSLaramie43 min
Jun 28, 7:47 PM MDTSpecial Weather StatementCYSConverse58 min
Jun 28, 8:15 PM MDTSevere Thunderstorm WarningCYSConverse45 min
Jun 28, 8:18 PM MDTSpecial Weather StatementCYSAlbany42 min
Jun 29, 12:16 PM MDTSpecial Weather StatementCYSConverse44 min
Jun 29, 12:56 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSConverse52 min
Jun 29, 1:35 PM MDTSevere Thunderstorm WarningCYSConverse, Platte40 min
Jun 29, 1:59 PM MDTSevere Thunderstorm WarningCYSConverse46 min
Jun 29, 2:02 PM MDTSpecial Weather StatementCYSPlatte43 min
Jun 29, 2:12 PM MDTSevere Thunderstorm WarningCYSAlbany, Laramie, Platte63 min
Jun 29, 2:13 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSConverse, Platte47 min
Jun 29, 2:27 PM MDTSpecial Weather StatementCYSAlbany48 min
Jun 29, 2:41 PM MDTSevere Thunderstorm WarningCYSConverse49 min
Jun 29, 2:55 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSConverse, Goshen, Niobrara, Platte50 min
Jun 29, 2:56 PM MDTFlash Flood WarningCYSConverse3 hr
Jun 29, 3:11 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSLaramie, Platte64 min
Jun 29, 3:16 PM MDTSpecial Weather StatementCYSAlbany44 min
Jun 29, 3:16 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte29 min
Jun 29, 3:21 PM MDTSevere Thunderstorm WarningCYSNiobrara24 min
Jun 29, 3:44 PM MDTSevere Thunderstorm WarningCYSGoshen, Niobrara, Platte46 min
Jun 29, 3:54 PM MDTSpecial Weather StatementCYSCarbon51 min
Jun 29, 4:01 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSGoshen, Laramie, Platte74 min
Jun 29, 4:04 PM MDTFlash Flood WarningCYSNiobrara91 min
Jun 29, 4:28 PM MDTSpecial Weather StatementCYSGoshen32 min
Jun 29, 4:44 PM MDTSpecial Weather StatementCYSGoshen31 min
Jun 29, 5:04 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie71 min
Jun 29, 5:30 PM MDTAreal Flood AdvisoryCYSGoshen, Laramie3 hr
Jun 29, 5:52 PM MDTSpecial Weather StatementCYSLaramie38 min
Jun 29, 5:57 PM MDTSpecial Weather StatementCYSAlbany48 min

Nearby

Tornado Warnings in Wyoming, 2023Every tornado warning in 2023Tornadoes in 2023

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.