Alert archive / Wyoming / Tornado Warnings in 2017

Tornado Warning 8, NWS Riverton, WY

June 12, 2017Big Horn County, Washakie County, Wyoming

NWS Riverton, WY issued this tornado warning at Jun 12, 2017, 6:19 PM MDT for Big Horn County, Washakie County, Wyoming. It was in force for 26 min. 1 report 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
Jun 12, 2017, 6:19 PM MDT (00:19 UTC)
Expired
Jun 12, 2017, 6:45 PM MDT
In force
26 min
Issued by
NWS Riverton, WY
Area
Storm-based polygon
Tornado
Observed
Hail
1.5 in

Counties Big Horn County, WY, Washakie County, WY

The radar

The Riverton/Lander radar (KRIW), 147 km from the middle of the area, began a volume at 00:22 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.

What was reported inside it

TimeReportWhereRemark
Jun 12, 6:21 PM MDTTORNADO4 W Burlington, WYPHOTO RECEIVED OF ROPE TORNADO WEST OF BURLINGTON

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
Jun 12, 2:45 PM MDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Riverton, WY (KRIW), launched 00:00Z, 0.3 hours before the alert went out and 147 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 00:00Z on 2017-06-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 804 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 00:00Z on 2017-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 square meters per square second.1939587897117Sfc1 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
804 J/kg
Mixed-layer CIN
-131 J/kg
Mixed-layer LCL
2386 m above ground
0-6 km bulk shear
65 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted.

163 
WFUS55 KRIW 130019
TORRIW
WYC003-043-130045-
/O.NEW.KRIW.TO.W.0008.170613T0019Z-170613T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Riverton WY
619 PM MDT MON JUN 12 2017

The National Weather Service in Riverton has issued a

* Tornado Warning for...
  Southwestern Big Horn County in central Wyoming...
  Northwestern Washakie County in central Wyoming...

* Until 645 PM MDT

* At 618 PM MDT, a confirmed tornado was located 14 miles southwest
  of Otto, which is 21 miles east of Meeteetse, moving north at 45
  mph.

  HAZARD...Damaging tornado and ping pong ball size hail. 

  SOURCE...Weather spotters confirmed tornado. 

  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. 

* The tornado will be near...
  Otto around 635 PM MDT. 

Other locations impacted by this tornadic thunderstorm include Rocky
Mountain High School, Emblem and Burlington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. 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.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Riverton.

&&

LAT...LON 4476 10814 4413 10833 4415 10855 4417 10855
      4417 10857 4419 10858 4480 10852
TIME...MOT...LOC 0018Z 187DEG 38KT 4423 10844 

TORNADO...OBSERVED
HAIL...1.50IN

$$

TL
2 follow-up statements
791 
WWUS55 KRIW 130032
SVSRIW

Severe Weather Statement
National Weather Service Riverton WY
632 PM MDT MON JUN 12 2017

WYC043-130040-
/O.CAN.KRIW.TO.W.0008.000000T0000Z-170613T0045Z/
Washakie-
632 PM MDT MON JUN 12 2017

...THE TORNADO WARNING FOR NORTHWESTERN WASHAKIE 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
central Wyoming.

LAT...LON 4427 10830 4429 10855 4445 10855 4462 10854
      4459 10819 4444 10824
TIME...MOT...LOC 0030Z 187DEG 38KT 4436 10842 

$$

WYC003-130045-
/O.CON.KRIW.TO.W.0008.000000T0000Z-170613T0045Z/
Big Horn-
632 PM MDT MON JUN 12 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM MDT FOR
SOUTHWESTERN BIG HORN COUNTY...
    
At 630 PM MDT, a confirmed tornado was located 7 miles west of Otto,
which is 18 miles west of Basin, moving north at 45 mph.

HAZARD...Damaging tornado and ping pong ball size hail. 

SOURCE...Weather spotters confirmed tornado. 

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 tornado will be near...
  Otto around 635 PM MDT. 

Other locations impacted by this tornadic thunderstorm include Emblem
and Burlington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. 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.

If a tornado or other severe weather is spotted, report it to the
National Weather Service or your local nearest law enforcement agency
who will send your report. This act may save lives of others in the
path of dangerous weather.

&&

LAT...LON 4427 10830 4429 10855 4445 10855 4462 10854
      4459 10819 4444 10824
TIME...MOT...LOC 0030Z 187DEG 38KT 4436 10842 

TORNADO...OBSERVED
HAIL...1.50IN

$$

TL
117 
WWUS55 KRIW 130042
SVSRIW

Severe Weather Statement
National Weather Service Riverton WY
642 PM MDT MON JUN 12 2017

WYC003-130052-
/O.EXP.KRIW.TO.W.0008.000000T0000Z-170613T0045Z/
Big Horn-
642 PM MDT MON JUN 12 2017

...THE TORNADO WARNING FOR SOUTHWESTERN BIG HORN COUNTY WILL EXPIRE
AT 645 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.

A severe thunderstorm watch remains in effect until 1000 PM MDT for
central Wyoming.

LAT...LON 4427 10830 4429 10855 4445 10855 4462 10854
      4459 10819 4444 10824
TIME...MOT...LOC 0042Z 187DEG 38KT 4447 10840 

$$

TL

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 12, 6:00 PM MDTTornado Warning Tornado observedRIWJohnson30 min
Jun 12, 6:02 PM MDTSevere Thunderstorm WarningRIWBig Horn, Park19 min
Jun 12, 6:18 PM MDTSevere Thunderstorm WarningRIWNatrona26 min
Jun 12, 6:19 PM MDTSevere Thunderstorm WarningRIWPark15 min
Jun 12, 6:20 PM MDTSpecial Weather StatementRIWWashakie25 min
Jun 12, 6:24 PM MDTSpecial Weather StatementRIWNatrona36 min
Jun 12, 6:32 PM MDTTornado WarningRIWJohnson28 min
Jun 12, 6:35 PM MDTSpecial Weather StatementRIWNatrona25 min
Jun 12, 6:36 PM MDTSpecial Weather StatementRIW24 min
Jun 12, 6:40 PM MDTTornado Warning Tornado observedRIWNatrona35 min
Jun 12, 6:42 PM MDTSpecial Weather StatementRIWNatrona33 min
Jun 12, 6:45 PM MDTSpecial Weather StatementRIWJohnson30 min
Jun 12, 6:51 PM MDTSpecial Weather StatementRIWWashakie24 min
Jun 12, 6:56 PM MDTSevere Thunderstorm WarningRIWBig Horn, Johnson, Washakie34 min
Jun 12, 7:02 PM MDTSevere Thunderstorm WarningRIWJohnson43 min
Jun 12, 7:07 PM MDTSevere Thunderstorm WarningRIWJohnson, Natrona53 min
Jun 12, 7:12 PM MDTSpecial Weather StatementRIWJohnson33 min
Jun 12, 7:16 PM MDTAreal Flood AdvisoryRIWJohnson4 hr
Jun 12, 7:18 PM MDTSevere Thunderstorm WarningRIWJohnson, Natrona27 min
Jun 12, 7:34 PM MDTSevere Thunderstorm WarningRIWBig Horn, Johnson, Washakie19 min
Jun 12, 7:44 PM MDTSevere Thunderstorm WarningRIWJohnson46 min
Jun 12, 7:46 PM MDTSpecial Weather StatementRIW29 min
Jun 12, 7:49 PM MDTSpecial Weather StatementRIW26 min
Jun 12, 8:02 PM MDTSpecial Weather StatementRIWJohnson28 min
Jun 12, 8:03 PM MDTSpecial Weather StatementRIWJohnson27 min
Jun 12, 8:13 PM MDTSpecial Weather StatementRIWBig Horn32 min
Jun 12, 8:18 PM MDTSpecial Weather StatementRIWPark27 min
Jun 12, 8:21 PM MDTSpecial Weather StatementRIWBig Horn24 min
Jun 12, 8:31 PM MDTSpecial Weather StatementRIWJohnson29 min
Jun 12, 8:45 PM MDTSpecial Weather StatementRIW45 min
Jun 12, 8:47 PM MDTFlash Flood WarningRIWJohnson4 hr
Jun 12, 8:52 PM MDTFlash Flood WarningRIWJohnson4 hr
Jun 12, 8:57 PM MDTSpecial Weather StatementRIWJohnson33 min
Jun 12, 9:27 PM MDTSpecial Weather StatementRIWJohnson33 min
Jun 12, 10:56 PM MDTHigh Wind WarningRIWFremont, Natrona, Sweetwater22 hr
Jun 13, 12:22 AM MDTFlash Flood WarningRIWJohnson4 hr

Nearby

Tornado Warnings in Wyoming, 2017Every tornado warning in 2017Tornadoes in 2017

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.