Alert archive / Wyoming / Tornado Warnings in 2018

Tornado Warning 20, NWS Cheyenne, WY

July 26, 2018Converse County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jul 26, 2018, 3:18 PM MDT for Converse County, Wyoming. It was in force for 27 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 26, 2018, 3:18 PM MDT (21:18 UTC)
Expired
Jul 26, 2018, 3:45 PM MDT
In force
27 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.75 in

County Converse County, WY

The radar

The Riverton/Lander radar (KRIW), 206 km from the middle of the area, began a volume at 21:22 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.

The watch it was issued in

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

IssuedProductOfficeLasted
Jul 26, 1:49 PM MDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 9.3 hours before the alert went out and 200 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 2018-07-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 38 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 2018-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 square meters per square second.1939587897Sfc1 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
38 J/kg
Mixed-layer CIN
-304 J/kg
Mixed-layer LCL
1416 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
95 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

033 
WFUS55 KCYS 262118
TORCYS
WYC009-262145-
/O.NEW.KCYS.TO.W.0020.180726T2118Z-180726T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Cheyenne WY
318 PM MDT THU JUL 26 2018

The National Weather Service in Cheyenne has issued a

* Tornado Warning for...
  West central Converse County in east central Wyoming...

* Until 345 PM MDT.
    
* At 318 PM MDT, a severe thunderstorm capable of producing a tornado
  was located 7 miles east of Teapot Rock, or 29 miles north of
  Casper, moving southeast at 35 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
  west central Converse 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 4308 10580 4295 10607 4333 10607
TIME...MOT...LOC 2118Z 322DEG 31KT 4324 10617 

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

$$

Lyons
1 follow-up statement
124 
WWUS55 KCYS 262149
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
349 PM MDT THU JUL 26 2018

WYC009-262158-
/O.EXP.KCYS.TO.W.0020.000000T0000Z-180726T2145Z/
Converse WY-
349 PM MDT THU JUL 26 2018

...THE TORNADO WARNING FOR WEST CENTRAL CONVERSE COUNTY HAS
EXPIRED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been allowed to expire.  However small
hail and gusty winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
east central Wyoming.

Remember, a Severe Thunderstorm Warning still remains in effect for
Converese county until 4:30 pm mdt.

LAT...LON 4308 10580 4295 10607 4333 10607
TIME...MOT...LOC 2148Z 322DEG 31KT 4304 10596 

$$

Lyons

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 25, 6:08 PM MDTSpecial Weather StatementCYSConverse52 min
Jul 25, 6:25 PM MDTSpecial Weather StatementCYS35 min
Jul 25, 6:47 PM MDTSpecial Weather StatementCYSConverse28 min
Jul 25, 6:54 PM MDTSpecial Weather StatementCYSAlbany51 min
Jul 25, 7:05 PM MDTSpecial Weather StatementCYSConverse25 min
Jul 25, 7:11 PM MDTSpecial Weather StatementCYSNiobrara34 min
Jul 25, 7:39 PM MDTSpecial Weather StatementCYSAlbany, Platte51 min
Jul 26, 9:23 AM MDTFlash Flood WatchCYSGoshen, Laramie11 hr
Jul 26, 9:48 AM MDTSpecial Weather StatementCYSConverse42 min
Jul 26, 10:48 AM MDTSpecial Weather StatementCYSPlatte42 min
Jul 26, 10:57 AM MDTSevere Thunderstorm WarningCYSConverse, Platte33 min
Jul 26, 12:02 PM MDTSpecial Weather StatementCYSGoshen43 min
Jul 26, 2:19 PM MDTSpecial Weather StatementCYSLaramie41 min
Jul 26, 2:45 PM MDTSpecial Weather StatementCYS45 min
Jul 26, 2:58 PM MDTSpecial Weather StatementCYSConverse47 min
Jul 26, 3:31 PM MDTSpecial Weather StatementCYS44 min
Jul 26, 3:38 PM MDTSpecial Weather StatementCYSConverse52 min
Jul 26, 3:42 PM MDTSevere Thunderstorm WarningCYSConverse48 min
Jul 26, 3:45 PM MDTSpecial Weather StatementCYSPlatte45 min
Jul 26, 3:59 PM MDTSpecial Weather StatementCYSAlbany61 min
Jul 26, 4:08 PM MDTSevere Thunderstorm WarningCYSAlbany52 min
Jul 26, 4:09 PM MDTSpecial Weather StatementCYSConverse51 min
Jul 26, 4:26 PM MDTSevere Thunderstorm WarningCYSConverse24 min
Jul 26, 4:28 PM MDTSevere Thunderstorm WarningCYSAlbany, Carbon, Converse47 min
Jul 26, 4:46 PM MDTSevere Thunderstorm WarningCYSAlbany, Laramie, Platte44 min
Jul 26, 4:58 PM MDTSpecial Weather StatementCYSGoshen47 min
Jul 26, 5:12 PM MDTSevere Thunderstorm WarningCYSAlbany48 min
Jul 26, 5:28 PM MDTSevere Thunderstorm WarningCYSAlbany, Laramie47 min
Jul 26, 5:49 PM MDTSevere Thunderstorm WarningCYSAlbany, Laramie41 min

Nearby

Tornado Warnings in Wyoming, 2018Every tornado warning in 2018Tornadoes 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.