Alert archive / Wyoming / Tornado Warnings in 2019

Tornado Warning 13, NWS Riverton, WY

August 23, 2019Johnson County, Natrona County, Wyoming

NWS Riverton, WY issued this tornado warning at Aug 23, 2019, 5:12 PM MDT for Johnson County, Natrona County, Wyoming. It was in force for 33 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: Aug 23, 2019, 5:12 PM MDT (23:12 UTC)
Expired: Aug 23, 2019, 5:45 PM MDT
In force: 33 min
Issued by: NWS Riverton, WY
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Johnson County, WY, Natrona County, WY

The radar

The Riverton/Lander radar (KRIW), 186 km from the middle of the area, began a volume at 23:12 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

Riverton, WY (KRIW), launched 12:00Z, 11.2 hours before the alert went out and 180 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: 253 J/kg
Mixed-layer CIN: -192 J/kg
Mixed-layer LCL: 1818 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 89 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

853 
WFUS55 KRIW 232312
TORRIW
WYC019-025-232345-
/O.NEW.KRIW.TO.W.0013.190823T2312Z-190823T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Riverton WY
512 PM MDT Fri Aug 23 2019

The National Weather Service in Riverton has issued a

* Tornado Warning for...
  Southeastern Johnson County in north central Wyoming...
  Northeastern Natrona County in central Wyoming...

* Until 545 PM MDT.
    
* At 510 PM MDT, a severe thunderstorm capable of producing a tornado
  was located over Midwest, which is 27 miles southeast of Kaycee, 
  moving north at 30 mph. A second thunderstorm between Midwest and 
  Linch is also capable of producing a tornado and is moving north 
  at 30 mph. 

  HAZARD...Tornado and quarter 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
  southeastern Johnson and northeastern Natrona Counties, including
  the following locations... Sussex.

This includes Interstate 25 between mile markers 226 and 247.
 
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 4345 10612 4332 10619 4330 10630 4363 10662
      4380 10616
TIME...MOT...LOC 2310Z 166DEG 24KT 4339 10631 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Bourque

2 follow-up statements

224 
WWUS55 KRIW 232333
SVSRIW

Severe Weather Statement
National Weather Service Riverton WY
533 PM MDT Fri Aug 23 2019

WYC025-232342-
/O.CAN.KRIW.TO.W.0013.000000T0000Z-190823T2345Z/
Natrona-
533 PM MDT Fri Aug 23 2019

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

A Severe Thunderstorm Watch remains in effect until 1000 PM MDT for
north central Wyoming.

LAT...LON 4350 10613 4350 10634 4369 10647 4380 10616
TIME...MOT...LOC 2332Z 166DEG 24KT 4354 10636 

$$

WYC019-232345-
/O.CON.KRIW.TO.W.0013.000000T0000Z-190823T2345Z/
Johnson-
533 PM MDT Fri Aug 23 2019

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 545 PM MDT FOR
SOUTHEASTERN JOHNSON COUNTY...
    
At 532 PM MDT, a severe thunderstorm capable of producing a tornado
was located 9 miles southwest of Linch, which is 18 miles southeast
of Kaycee, moving north at 30 mph.

HAZARD...Tornado and quarter 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.

Locations impacted include...
Linch and Sussex. 

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 4350 10613 4350 10634 4369 10647 4380 10616
TIME...MOT...LOC 2332Z 166DEG 24KT 4354 10636 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Bourque

608 
WWUS55 KRIW 232340
SVSRIW

Severe Weather Statement
National Weather Service Riverton WY
540 PM MDT Fri Aug 23 2019

WYC019-232349-
/O.EXP.KRIW.TO.W.0013.000000T0000Z-190823T2345Z/
Johnson-
540 PM MDT Fri Aug 23 2019

...THE TORNADO WARNING FOR SOUTHEASTERN JOHNSON COUNTY WILL EXPIRE AT
545 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.  However small hail
is still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1000 PM MDT for
north central Wyoming.

LAT...LON 4350 10613 4350 10634 4369 10647 4380 10616
TIME...MOT...LOC 2339Z 166DEG 24KT 4358 10637 

$$

Bourque

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 22, 6:14 PM MDT	Special Weather Statement	RIW	Big Horn, Hot Springs, Washakie	91 min
Aug 22, 6:21 PM MDT	Special Weather Statement	RIW	Johnson	24 min
Aug 22, 6:34 PM MDT	Severe Thunderstorm Warning	RIW	Johnson	41 min
Aug 22, 6:55 PM MDT	Areal Flood Advisory	RIW	Johnson	2 hr
Aug 22, 7:21 PM MDT	Special Weather Statement	RIW	Johnson	39 min
Aug 22, 7:59 PM MDT	Severe Thunderstorm Warning	RIW	Johnson	31 min
Aug 22, 8:34 PM MDT	Flash Flood Warning	RIW	Johnson	3 hr
Aug 23, 12:53 PM MDT	Special Weather Statement	RIW		37 min
Aug 23, 1:31 PM MDT	Special Weather Statement	RIW		44 min
Aug 23, 1:47 PM MDT	Special Weather Statement	RIW		43 min
Aug 23, 2:18 PM MDT	Special Weather Statement	RIW	Hot Springs	27 min
Aug 23, 2:31 PM MDT	Special Weather Statement	RIW		44 min
Aug 23, 2:51 PM MDT	Special Weather Statement	RIW		24 min
Aug 23, 2:55 PM MDT	Special Weather Statement	RIW	Washakie	35 min
Aug 23, 2:58 PM MDT	Special Weather Statement	RIW		47 min
Aug 23, 3:11 PM MDT	Special Weather Statement	RIW		34 min
Aug 23, 3:19 PM MDT	Fire Weather Watch	RIW	Fremont, Lincoln, Natrona, Park, Sublette, Sweetwater and 2 more	23 hr
Aug 23, 3:25 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	50 min
Aug 23, 3:35 PM MDT	Severe Thunderstorm Warning	RIW	Fremont, Hot Springs	25 min
Aug 23, 3:50 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	25 min
Aug 23, 3:55 PM MDT	Areal Flood Advisory	RIW	Johnson, Washakie	3 hr
Aug 23, 3:58 PM MDT	Special Weather Statement	RIW	Natrona	32 min
Aug 23, 4:11 PM MDT	Special Weather Statement	RIW	Hot Springs	34 min
Aug 23, 4:21 PM MDT	Special Weather Statement	RIW	Natrona	24 min
Aug 23, 4:22 PM MDT	Areal Flood Advisory	RIW	Natrona	3 hr
Aug 23, 4:23 PM MDT	Special Weather Statement	RIW	Natrona	37 min
Aug 23, 4:29 PM MDT	Tornado Warning Tornado observed	RIW	Natrona	31 min
Aug 23, 4:34 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	11 min
Aug 23, 4:42 PM MDT	Tornado Warning	RIW	Johnson, Natrona	33 min
Aug 23, 4:44 PM MDT	Severe Thunderstorm Warning	RIW	Hot Springs, Washakie	31 min
Aug 23, 4:52 PM MDT	Special Weather Statement	RIW		23 min
Aug 23, 5:01 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	29 min
Aug 23, 5:04 PM MDT	Special Weather Statement	RIW		41 min
Aug 23, 5:15 PM MDT	Special Weather Statement	RIW	Hot Springs	30 min
Aug 23, 5:19 PM MDT	Special Weather Statement	RIW	Johnson	26 min
Aug 23, 5:40 PM MDT	Special Weather Statement	RIW	Natrona	35 min
Aug 23, 5:59 PM MDT	Special Weather Statement	RIW	Fremont	31 min

Nearby

Tornado Warnings in Wyoming, 2019 Every tornado warning in 2019 Tornadoes in 2019

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.