Alert archive / Wyoming / Tornado Warnings in 2011

Tornado Warning 6, NWS Riverton, WY

June 16, 2011Natrona County, Wyoming

NWS Riverton, WY issued this tornado warning at Jun 16, 2011, 5:26 PM MDT for Natrona County, Wyoming. It was in force for 34 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 16, 2011, 5:26 PM MDT (23:26 UTC)
Expired: Jun 16, 2011, 6:00 PM MDT
In force: 34 min
Issued by: NWS Riverton, WY
Area: Storm-based polygon

County Natrona County, WY

The radar

The Riverton/Lander radar (KRIW), 191 km from the middle of the area, began a volume at 23:25 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

Time	Report	Where	Remark
Jun 16, 5:28 PM MDT	FUNNEL CLOUD	7 Ne Evansville, WY	1/3 OF THE WAY TO THE GROUND

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 12:00Z, 11.4 hours before the alert went out and 185 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2040 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 201 m²/s²
0-3 km storm-relative helicity: 292 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

069 
WFUS55 KRIW 162326
TORRIW
WYC025-170000-
/O.NEW.KRIW.TO.W.0006.110616T2326Z-110617T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE RIVERTON WY
526 PM MDT THU JUN 16 2011

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

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

* UNTIL 600 PM MDT

* AT 525 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR I25 EXIT 197...OR 9 MILES NORTHEAST OF
  CASPER...AND MOVING NORTHEAST AT 35 MPH.

* THIS DANGEROUS STORM WILL AFFECT MAINLY RURAL AREAS OF EAST CENTRAL
  NATRONA COUNTY.

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 10620 4296 10626 4313 10616 4316 10608
      4316 10607 4307 10607 4306 10606 4289 10606
TIME...MOT...LOC 2326Z 220DEG 29KT 4296 10625

$$

C. BAKER

3 follow-up statements

070 
WWUS55 KRIW 162332
SVSRIW

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
532 PM MDT THU JUN 16 2011

WYC025-170000-
/O.CON.KRIW.TO.W.0006.000000T0000Z-110617T0000Z/
NATRONA WY-
532 PM MDT THU JUN 16 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR EAST CENTRAL NATRONA
COUNTY UNTIL 600 PM MDT...

AT 530 PM MDT...TRAINED WEATHER SPOTTERS REPORTED A FUNNEL CLOUD.  A
TORNADO MAY DEVELOP AT ANY TIME. THIS DANGEROUS STORM WAS LOCATED 6
MILES EAST OF I25 EXIT 197...OR 12 MILES NORTHEAST OF CASPER...MOVING
NORTHEAST AT 35 MPH.

LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF EXTREME EASTERN NATRONA COUNTY.

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.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN RIVERTON.

&&

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

LAT...LON 4295 10607 4294 10618 4300 10624 4313 10616
      4316 10608 4316 10607 4307 10607 4306 10606
TIME...MOT...LOC 2332Z 220DEG 29KT 4300 10621

$$

C. BAKER

807 
WWUS55 KRIW 162341
SVSRIW

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
541 PM MDT THU JUN 16 2011

WYC025-170000-
/O.CON.KRIW.TO.W.0006.000000T0000Z-110617T0000Z/
NATRONA WY-
541 PM MDT THU JUN 16 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR EAST CENTRAL NATRONA
COUNTY UNTIL 600 PM MDT...

AT 539 PM MDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO.  THIS
TORNADO WAS LOCATED 8 MILES EAST OF ANTELOPE HILLS...OR 17 MILES
NORTHEAST OF CASPER...MOVING NORTHEAST AT 35 MPH.

LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF EXTREME EASTERN NATRONA COUNTY.

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.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN RIVERTON.

&&

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

LAT...LON 4295 10607 4294 10618 4300 10624 4313 10616
      4316 10608 4316 10607 4307 10607 4306 10606
TIME...MOT...LOC 2341Z 220DEG 29KT 4306 10615

$$

C. BAKER

102 
WWUS55 KRIW 162353
SVSRIW

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
553 PM MDT THU JUN 16 2011

WYC025-170003-
/O.EXP.KRIW.TO.W.0006.000000T0000Z-110617T0000Z/
NATRONA WY-
553 PM MDT THU JUN 16 2011

...THE TORNADO WARNING FOR EAST CENTRAL NATRONA COUNTY WILL EXPIRE AT
600 PM MDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
HOWEVER HEAVY RAIN IS STILL POSSIBLE WITH THIS THUNDERSTORM.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN RIVERTON.

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

LAT...LON 4295 10607 4294 10618 4300 10624 4313 10616
      4316 10608 4316 10607 4307 10607 4306 10606
TIME...MOT...LOC 2353Z 220DEG 29KT 4313 10606

$$

C. BAKER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 15, 6:27 PM MDT	Special Weather Statement	RIW		33 min
Jun 16, 3:01 AM MDT	Flash Flood Watch	RIW	Big Horn, Fremont, Hot Springs, Johnson, Natrona, Park and 2 more	24 hr
Jun 16, 1:28 PM MDT	Special Weather Statement	RIW	Sweetwater	47 min
Jun 16, 1:31 PM MDT	Special Weather Statement	RIW	Natrona	44 min
Jun 16, 1:59 PM MDT	Special Weather Statement	RIW	Sweetwater	46 min
Jun 16, 2:09 PM MDT	Special Weather Statement	RIW	Sweetwater	51 min
Jun 16, 2:39 PM MDT	Severe Thunderstorm Warning	RIW	Sweetwater	66 min
Jun 16, 3:14 PM MDT	Special Weather Statement	RIW		46 min
Jun 16, 3:18 PM MDT	Special Weather Statement	RIW	Natrona	42 min
Jun 16, 3:54 PM MDT	Special Weather Statement	RIW	Natrona	51 min
Jun 16, 4:01 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	44 min
Jun 16, 4:26 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	49 min
Jun 16, 4:38 PM MDT	Special Weather Statement	RIW	Natrona	37 min
Jun 16, 4:49 PM MDT	Severe Thunderstorm Warning	RIW	Natrona	41 min
Jun 16, 5:45 PM MDT	Special Weather Statement	RIW	Natrona	45 min

Nearby

Tornado Warnings in Wyoming, 2011 Every tornado warning in 2011 Tornadoes 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.