Alert archive / Wyoming / Tornado Warnings in 2018

Tornado Warning 21, NWS Cheyenne, WY

July 28, 2018Converse County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jul 28, 2018, 3:12 PM MDT for Converse County, Wyoming. It was in force for 48 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
Jul 28, 2018, 3:12 PM MDT (21:12 UTC)
Expired
Jul 28, 2018, 4:00 PM MDT
In force
48 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.75 in

County Converse County, WY

The radar

The Cheyenne radar (KCYS), 212 km from the middle of the area, began a volume at 21:15 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

TimeReportWhereRemark
Jul 28, 3:56 PM MDTTORNADO8 Wnw Douglas, WYMOVING TO THE SOUTHEAST
Jul 28, 3:59 PM MDTTORNADO12 W Douglas, WYAYERS NATURAL BRIDGE.

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.

IssuedProductOfficeLasted
Jul 28, 2:34 PM MDTTornado WatchSPC7 hr

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 9.2 hours before the alert went out and 222 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 2018-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 33 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 2018-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 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
33 J/kg
Mixed-layer CIN
-324 J/kg
Mixed-layer LCL
1147 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
407 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

442 
WFUS55 KCYS 282112
TORCYS
WYC009-282200-
/O.NEW.KCYS.TO.W.0021.180728T2112Z-180728T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Cheyenne WY
312 PM MDT SAT JUL 28 2018

The National Weather Service in Cheyenne has issued a

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

* Until 400 PM MDT.
    
* At 312 PM MDT, a severe thunderstorm capable of producing a tornado
  was located 7 miles north of Rolling Hills, or 26 miles northeast
  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 dangerous storm will be near...
  Rolling Hills and Rolling Hills Estates around 320 PM MDT.
  Glenrock around 325 PM MDT.
  Deer Creek around 330 PM MDT.
  Laprele Reservoir around 350 PM MDT.
  Douglas around 400 PM MDT.

This includes Interstate 25 in Wyoming between mile markers 139 and
172.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

This Tornado Warning replaces the Severe Thunderstorm Warning issued
for the same area.

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 4299 10502 4244 10586 4297 10608 4306 10607
      4321 10597
TIME...MOT...LOC 2112Z 315DEG 32KT 4301 10586 

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

$$

Hammer
2 follow-up statements
833 
WWUS55 KCYS 282134
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
334 PM MDT SAT JUL 28 2018

WYC009-282200-
/O.CON.KCYS.TO.W.0021.000000T0000Z-180728T2200Z/
Converse WY-
334 PM MDT SAT JUL 28 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 400 PM MDT FOR
SOUTHWESTERN CONVERSE COUNTY...
    
At 333 PM MDT, a severe thunderstorm capable of producing a tornado
was located near Deer Creek, or 16 miles northwest of Douglas, moving
southeast at 35 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 dangerous storm will be near...
  Laprele Reservoir around 350 PM MDT.
  Douglas around 400 PM MDT.

This includes Interstate 25 in Wyoming between mile markers 139 and
166.
 
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 4288 10519 4248 10580 4293 10593 4305 10574
TIME...MOT...LOC 2133Z 315DEG 32KT 4287 10567 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

Hammer
182 
WWUS55 KCYS 282145
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
345 PM MDT SAT JUL 28 2018

WYC009-282200-
/O.CON.KCYS.TO.W.0021.000000T0000Z-180728T2200Z/
Converse WY-
345 PM MDT SAT JUL 28 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 400 PM MDT FOR CENTRAL
CONVERSE COUNTY...
    
At 344 PM MDT, a severe thunderstorm with a history of producing 
tornadoes was located near Laprele Reservoir, or 9 miles west of 
Douglas, moving southeast at 35 mph.

HAZARD...Tornado and ping pong ball size hail.

SOURCE...Radar indicated rotation. This storm has a history of 
         producing tornadoes! 

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...
  Douglas around 400 PM MDT.

If in the Douglas area, seek shelter immediately! 

This includes Interstate 25 in Wyoming between mile markers 139 and
159.
 
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 4283 10527 4255 10570 4287 10578 4295 10555
TIME...MOT...LOC 2144Z 315DEG 32KT 4280 10558 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

Hammer

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 6:08 PM MDTSevere Thunderstorm WarningCYSAlbany, Converse, Platte52 min
Jul 27, 7:04 PM MDTSpecial Weather StatementCYSPlatte41 min
Jul 27, 7:09 PM MDTSevere Thunderstorm WarningCYSAlbany, Platte29 min
Jul 27, 8:01 PM MDTSevere Thunderstorm WarningCYSConverse29 min
Jul 27, 8:25 PM MDTSevere Thunderstorm WarningCYSConverse50 min
Jul 27, 9:03 PM MDTSevere Thunderstorm WarningCYSConverse42 min
Jul 27, 9:25 PM MDTSpecial Weather StatementCYSConverse50 min
Jul 27, 9:31 PM MDTSevere Thunderstorm WarningCYSConverse29 min
Jul 27, 9:36 PM MDTSpecial Weather StatementCYSNiobrara39 min
Jul 28, 3:02 PM MDTSevere Thunderstorm WarningCYSConverse43 min
Jul 28, 3:27 PM MDTTornado WarningCYSGoshen, Platte33 min
Jul 28, 3:32 PM MDTSevere Thunderstorm WarningCYSConverse, Niobrara, Platte43 min
Jul 28, 3:49 PM MDTTornado WarningCYSAlbany, Converse, Platte41 min
Jul 28, 3:55 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie35 min
Jul 28, 4:26 PM MDTTornado Warning Tornado observedConsiderable damage threatCYSAlbany, Converse, Platte34 min
Jul 28, 4:29 PM MDTSevere Thunderstorm WarningCYSLaramie46 min
Jul 28, 4:53 PM MDTTornado WarningCYSGoshen, Platte52 min
Jul 28, 5:30 PM MDTSpecial Weather StatementCYSConverse45 min
Jul 28, 5:43 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte47 min
Jul 28, 5:56 PM MDTSevere Thunderstorm WarningCYSConverse64 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.