Alert archive / Wyoming / Tornado Warnings in 2011

Tornado Warning 27, NWS Cheyenne, WY

July 12, 2011Goshen County, Laramie County, Platte County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jul 12, 2011, 6:03 PM MDT for Goshen County, Laramie County, Platte County, Wyoming. It was in force for 30 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
Jul 12, 2011, 6:03 PM MDT (00:03 UTC)
Expired
Jul 12, 2011, 6:33 PM MDT
In force
30 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon

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

The radar

The Cheyenne radar (KCYS), 65 km from the middle of the area, began a volume at 00:05 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 (KDNR), launched 00:00Z, 0.1 hours before the alert went out and 250 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, Denver, CO at 00:00Z on 2011-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 596 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2011-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 square meters per square second.1939Sfc1 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
596 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
1449 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
256 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

622 
WFUS55 KCYS 130003
TORCYS
WYC015-021-031-130045-
/O.NEW.KCYS.TO.W.0027.110713T0003Z-110713T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
603 PM MDT TUE JUL 12 2011

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHWESTERN GOSHEN COUNTY IN SOUTHEAST WYOMING...
  NORTH CENTRAL LARAMIE COUNTY IN SOUTHEAST WYOMING...
  SOUTHEASTERN PLATTE COUNTY IN SOUTHEAST WYOMING...

* UNTIL 645 PM MDT

* AT 601 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 11 MILES SOUTHWEST OF CHUGWATER...OR 29 MILES
  SOUTH OF WHEATLAND...AND MOVING NORTHEAST AT 25 MPH.

* LOCATIONS IMPACTED INCLUDE...
  CHUGWATER...I-25 EXIT 54 AND I-25 EXIT 65.

THIS INCLUDES INTERSTATE 25 IN WYOMING BETWEEN MILE MARKERS 38 AND
69.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN CHEYENNE.

&&

LAT...LON 4194 10499 4170 10440 4151 10489 4160 10510
TIME...MOT...LOC 0003Z 211DEG 22KT 4164 10493

$$

CLAYCOMB
2 follow-up statements
635 
WWUS55 KCYS 130027
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
627 PM MDT TUE JUL 12 2011

WYC015-021-031-130045-
/O.CON.KCYS.TO.W.0027.000000T0000Z-110713T0045Z/
GOSHEN WY-LARAMIE WY-PLATTE WY-
627 PM MDT TUE JUL 12 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN PLATTE...
NORTH CENTRAL LARAMIE AND SOUTHWESTERN GOSHEN COUNTIES UNTIL 645 PM
MDT...

AT 623 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED 7 MILES SOUTH OF CHUGWATER...OR 28 MILES SOUTH OF
WHEATLAND...MOVING NORTHEAST AT 30 MPH.

LOCATIONS IMPACTED INCLUDE...
  CHUGWATER...I-25 EXIT 54 AND I-25 EXIT 65.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN CHEYENNE.

&&

LAT...LON 4167 10508 4194 10499 4170 10440 4157 10473
TIME...MOT...LOC 0026Z 206DEG 26KT 4168 10485

$$

CLAYCOMB
201 
WWUS55 KCYS 130033
SVSCYS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
633 PM MDT TUE JUL 12 2011

WYC015-021-031-130044-
/O.CAN.KCYS.TO.W.0027.000000T0000Z-110713T0045Z/
GOSHEN WY-LARAMIE WY-PLATTE WY-
633 PM MDT TUE JUL 12 2011

...THE TORNADO WARNING FOR SOUTHEASTERN PLATTE...NORTH CENTRAL
LARAMIE AND SOUTHWESTERN GOSHEN COUNTIES IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN CHEYENNE.

LAT...LON 4167 10508 4194 10499 4170 10440 4157 10473
TIME...MOT...LOC 0034Z 206DEG 26KT 4173 10482

$$

CLAYCOMB

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 6:03 PM MDTTornado WarningCYSLaramie27 min
Jul 12, 6:56 PM MDTSevere Thunderstorm WarningCYSLaramie45 min
Jul 12, 7:09 PM MDTFlash Flood WarningCYSGoshen, Laramie8 hr
Jul 12, 7:46 PM MDTSevere Thunderstorm WarningCYSLaramie32 min
Jul 12, 10:26 PM MDTFlash Flood WarningCYSGoshen, Laramie, Platte4 hr

Nearby

Tornado Warnings in Wyoming, 2011Every tornado warning in 2011Tornadoes in 2011

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.