Alert archive / Wyoming / Tornado Warnings in 2011

Tornado Warning 2, NWS Riverton, WY

June 8, 2011Natrona County, Wyoming

NWS Riverton, WY issued this tornado warning at Jun 8, 2011, 6:39 PM MDT for Natrona County, Wyoming. It was in force for 36 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 8, 2011, 6:39 PM MDT (00:39 UTC)
Expired
Jun 8, 2011, 7:15 PM MDT
In force
36 min
Issued by
NWS Riverton, WY
Area
Storm-based polygon

County Natrona County, WY

The radar

The Riverton/Lander radar (KRIW), 146 km from the middle of the area, began a volume at 00:40 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, 7:25 PM MDTFUNNEL CLOUD15 W Casper, WYTWO REPORTS OF FUNNEL CLOUDS APPROXIMATELY 15 MILES WEST OF CASPER. REPORTED BY NATRONA COUNTY DISPATCH.

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, 0.7 hours before the alert went out and 140 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.

112 
WFUS55 KRIW 090039
TORRIW
WYC025-090115-
/O.NEW.KRIW.TO.W.0002.110609T0039Z-110609T0115Z/

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

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

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

* UNTIL 715 PM MDT

* AT 636 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 12 MILES SOUTH OF POWDER RIVER...OR 29 MILES WEST
  OF CASPER...AND MOVING EAST AT 30 MPH.

* THIS DANGEROUS STORM WILL BE NEAR...
  U.S. HWY 20/26 MILE MARKER 20 AROUND 705 PM MDT.
  EMIGRANT GAP AROUND 710 PM MDT.

OTHER LOCATIONS IMPACTED BY THIS DANGEROUS STORM INCLUDE U.S. HWY 
20/26 BETWEEN MILEPOSTS 10 AND 20.

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 4308 10651 4278 10642 4275 10700 4297 10703
TIME...MOT...LOC 0039Z 258DEG 27KT 4287 10687

$$

JONES
1 follow-up statement
495 
WWUS55 KRIW 090051
SVSRIW

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

WYC025-090115-
/O.CON.KRIW.TO.W.0002.000000T0000Z-110609T0115Z/
NATRONA WY-
651 PM MDT WED JUN 8 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR CENTRAL NATRONA COUNTY
UNTIL 715 PM MDT...

AT 650 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED 8 MILES SOUTHWEST OF U.S. HWY 20/26 MILE MARKER
20...OR 23 MILES WEST OF CASPER...MOVING EAST AT 30 MPH.

THIS DANGEROUS STORM WILL BE NEAR...
  U.S. HWY 20/26 MILE MARKER 20 AROUND 700 PM MDT.
  EMIGRANT GAP AROUND 710 PM MDT.

OTHER LOCATIONS IMPACTED BY THIS DANGEROUS STORM INCLUDE U.S. HWY 
20/26 BETWEEN MILEPOSTS 10 AND 20.

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 4277 10687 4299 10691 4308 10651 4278 10642
TIME...MOT...LOC 0051Z 258DEG 27KT 4290 10674

$$

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, 6:54 PM MDTSpecial Weather StatementRIW51 min
Jun 8, 7:15 PM MDTTornado WarningRIWNatrona30 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.