Alert archive / Wyoming / Tornado Warnings in 2011

Tornado Warning 3, NWS Riverton, WY

June 8, 2011Natrona County, Wyoming

NWS Riverton, WY issued this tornado warning at Jun 8, 2011, 7:15 PM MDT for Natrona County, Wyoming. It was in force for 30 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
Jun 8, 2011, 7:15 PM MDT (01:15 UTC)
Expired
Jun 8, 2011, 7:45 PM MDT
In force
30 min
Issued by
NWS Riverton, WY
Area
Storm-based polygon

County Natrona County, WY

The radar

The Riverton/Lander radar (KRIW), 176 km from the middle of the area, began a volume at 01:18 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 8, 7:37 PM MDTHAIL 1.25Natrona County Airport, WYREPORTED BY TV METEOROLOGIST NEAR THE CASPER-NATRONA COUNTY INTERNATIONAL AIRPORT.
Jun 8, 7:45 PM MDTHAIL 24 N Bar Nunn, WYTRAINED SPOTTER AND OFF-DUTY NWS METEOROLOGIST EACH REPORTED 2 INCH DIAMETER HAIL NEAR MILEPOST 195 ON INTERSTATE 25.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Riverton, WY (KRIW), launched 00:00Z, 1.3 hours before the alert went out and 170 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 2011-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 78 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 2011-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 square meters per square second.19395878Sfc1 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
78 J/kg
Mixed-layer CIN
-112 J/kg
Mixed-layer LCL
1730 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
234 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

787 
WFUS55 KRIW 090115
TORRIW
WYC025-090145-
/O.NEW.KRIW.TO.W.0003.110609T0115Z-110609T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE RIVERTON WY
715 PM MDT WED JUN 8 2011

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

* TORNADO WARNING FOR...
  EAST CENTRAL NATRONA COUNTY IN CENTRAL WYOMING...

* UNTIL 745 PM MDT

* AT 714 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS
  DANGEROUS STORM WAS LOCATED NEAR NATRONA COUNTY AIRPORT...OR 12
  MILES NORTHWEST OF CASPER...AND MOVING EAST AT 30 MPH. A FUNNEL
  CLOUD AND ROTATION HAS BEEN NOTED WITH THIS STORM.

* THIS DANGEROUS STORM WILL BE NEAR...
  NATRONA COUNTY AIRPORT AROUND 720 PM MDT.
  BAR NUNN...HOMA HILLS AROUND 730 PM MDT.
  I25 EXIT 197 AND I25 MILE MARKER 200 AROUND 735 PM MDT.
  EVANSVILLE AROUND 740 PM MDT.

OTHER LOCATIONS IMPACTED BY THIS DANGEROUS STORM INCLUDE U.S. HWY
20/26 MILE MARKER 10 AND CASPER EVENTS CENTER.

THIS INCLUDES INTERSTATE 25 IN WYOMING BETWEEN MILE MARKERS 189 AND
202.

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.

&&

REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN
RIVERTON AT 1-800-211-1448.

LAT...LON 4310 10608 4287 10608 4284 10664 4299 10668
TIME...MOT...LOC 0115Z 258DEG 28KT 4292 10653

$$

JONES
2 follow-up statements
237 
WWUS55 KRIW 090125
SVSRIW

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
725 PM MDT WED JUN 8 2011

WYC025-090145-
/O.CON.KRIW.TO.W.0003.000000T0000Z-110609T0145Z/
NATRONA WY-
725 PM MDT WED JUN 8 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR EAST CENTRAL NATRONA
COUNTY UNTIL 745 PM MDT...

AT 722 PM MDT...TRAINED WEATHER SPOTTERS REPORTED A FUNNEL CLOUD AND 
ROTATION IN ASSOCIATION WITH THE WARNED THUNDERSTORM. THE STORM WAS 
LOCATED NEAR CASPER-NATRONA COUNTY INTERNATIONAL AIRPORT...MOVING 
EAST AT 30 MPH.

IN ADDITION...HAIL OF ONE-HALF TO ONE INCH IN DIAMETER WAS REPORTED 
ON HIGHWAY 20/26 WEST OF THE CASPER AIRPORT. 

THE TORNADO WILL BE NEAR...
  BAR NUNN AND HOMA HILLS AROUND 730 PM MDT.
  
OTHER LOCATIONS IMPACTED BY THE TORNADO INCLUDE INTERSTATE 25 
BETWEEN MILEPOSTS 191 AND 210.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPEAT...A TORNADO IS ON THE GROUND. 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.

&&

REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN
RIVERTON AT 1-800-211-1448.

LAT...LON 4285 10655 4300 10658 4310 10608 4287 10608
TIME...MOT...LOC 0122Z 258DEG 28KT 4293 10646

$$

JONES
489 
WWUS55 KRIW 090135
SVSRIW

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
735 PM MDT WED JUN 8 2011

WYC025-090145-
/O.CON.KRIW.TO.W.0003.000000T0000Z-110609T0145Z/
NATRONA WY-
735 PM MDT WED JUN 8 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR EAST CENTRAL NATRONA
COUNTY UNTIL 745 PM MDT...

AT 731 PM MDT...TRAINED WEATHER SPOTTERS REPORTED A FUNNEL CLOUD.  A
TORNADO MAY DEVELOP AT ANY TIME. THIS DANGEROUS STORM WAS LOCATED
NEAR HOMA HILLS...OR 9 MILES NORTH OF CASPER...MOVING EAST AT 30 MPH.

HAIL OF ONE INCH IN DIAMETER HAS ALSO BEEN REPORTED WITH THIS STORM.

THIS DANGEROUS STORM WILL BE NEAR...
  HOMA HILLS AND INTERSTATE 25 MILEPOST 195 UNTIL 745 PM MDT.

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.

&&

REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN
RIVERTON AT 1-800-211-1448.

LAT...LON 4288 10643 4302 10649 4310 10608 4291 10608
TIME...MOT...LOC 0133Z 252DEG 25KT 4296 10637

$$

JONES

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 8, 6:25 PM MDTSevere Thunderstorm WarningRIWNatrona65 min
Jun 8, 6:39 PM MDTTornado WarningRIWNatrona36 min
Jun 8, 6:54 PM MDTSpecial Weather StatementRIW51 min
Jun 8, 7:33 PM MDTSpecial Weather StatementRIWFremont27 min
Jun 8, 7:42 PM MDTSevere Thunderstorm WarningRIWNatrona33 min
Jun 8, 7:46 PM MDTTornado WarningRIWNatrona29 min
Jun 8, 8:02 PM MDTSpecial Weather StatementRIWFremont43 min
Jun 8, 8:47 PM MDTSpecial Weather StatementRIWFremont43 min
Jun 8, 10:21 PM MDTSpecial Weather StatementRIW39 min
Jun 8, 10:31 PM MDTSevere Thunderstorm WarningRIWNatrona29 min
Jun 9, 12:19 AM MDTSpecial Weather StatementRIWJohnson26 min
Jun 9, 1:02 PM MDTSpecial Weather StatementRIWFremont43 min
Jun 9, 1:40 PM MDTSpecial Weather StatementRIWFremont50 min
Jun 9, 2:06 PM MDTSpecial Weather StatementRIWHot Springs39 min
Jun 9, 2:32 PM MDTSpecial Weather StatementRIWWashakie43 min
Jun 9, 2:56 PM MDTSpecial Weather StatementRIWWashakie49 min
Jun 9, 3:07 PM MDTFlash Flood WarningRIWHot Springs, Washakie113 min
Jun 9, 5:17 PM MDTAreal Flood AdvisoryRIWHot Springs, Washakie19 hr
Jun 9, 5:43 PM MDTSpecial Weather StatementRIWFremont47 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.