Alert archive / Wyoming / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 16, NWS Riverton, WY

June 26, 2001Big Horn County, Wyoming

NWS Riverton, WY issued this severe thunderstorm warning at Jun 26, 2001, 7:13 PM MDT for Big Horn County, Wyoming. It was in force for 47 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 26, 2001, 7:13 PM MDT (01:13 UTC)
Expired
Jun 26, 2001, 8:00 PM MDT
In force
47 min
Issued by
NWS Riverton, WY
Area
Whole counties

County Big Horn County, WY

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 26, 5:00 PM MDTTornado WatchSPC6 hr

The nearest sounding before it

Riverton, WY (KRIW), launched 00:00Z, 1.2 hours before the alert went out and 165 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 2001-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 145 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 00:00Z on 2001-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 square meters per square second.193958Sfc1 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
145 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
3130 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

000 
WUUS55 KRIW 270115
SVRRIW
WYC003-270200-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE RIVERTON WY
713 PM MDT TUE JUN 26 2001

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN BIG HORN COUNTY IN NORTH CENTRAL WYOMING

* UNTIL 800 PM MDT

* AT 713 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A SEVERE THUNDERSTORM 4 MILES SOUTHEAST OF GREYBULL...MOVING   
  NORTH AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE...
  6 MILES EAST OF GREYBULL AROUND 720 PM MDT

THE SEVERE THUNDERSTORM IS CAPABLE OF PRODUCING...
 HAIL UP TO THE SIZE OF NICKELS.
 DAMAGING WINDS GREATER THAN 60 MILES AN HOUR.
 FREQUENT CLOUD-TO-GROUND LIGHTNING.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH YOU SHOULD PREPARE
FOR DAMAGING WINDS IN EXCESS OF 55 MPH...LARGE HAIL...AND DEADLY
LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY
INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

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

A TORNADO WATCH IS ALSO IN EFFECT FOR THE WARNED AREA. REMEMBER...
SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH
LITTLE OR NO ADVANCE WARNING. REMAIN CALM BUT BE ALERT FOR RAPIDLY
CHANGING WEATHER CONDITIONS.

$$
LAT...LON 4432 10845 4432 10783 4496 1x0790 4498 10853

SULLIVAN

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Riverton, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 26, 1:00 PM MDT, 6 hours 13 minutes earlier.

Area forecast discussion, Jun 26, 1:00 PM MDT, 6 hours 13 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1 PM MDT TUE JUN 26 2001

ISOLD CNVCTN FIRING UP AT 1230 PM THIS AFTN WITH AN OTHERWISE FAIR
SKY. ETA/AVN MDLS IN AGRMNT WITH MAIN FTRS THIS RUN...BUT THE ETA
HNDLG SHORT TERM DETAILS BTR. LOW LVL CNVRGNC ZONE OVR CNTRL FCST
AREA THIS AFTN WITH SHT/WVS MOVG UP FM THE SOUTH WILL KICK OFF
CNVCTN THIS AFTN. DWPTS ARE RISING WITH LOW LVL MSTR FLUX FM THE
SE...SO THESE STRMS SHOULD HAVE SOME HEAVY SHWRS AND HAIL. THETA-E
RDG THRU THIS EVG AT H8 RUNS OVR MAINLY THE FAR E AND STRETCHES TO
THE NRN AND NE FCST AREAS. WITH THE RMNTS OF THE SRN CA UPR LOW MOVG
INTO THE SW LT TNGHT WILL KEEP TSTMS GOING ALL NIGHT. WITH A SFC
LOW DVLPG OVR SW WY THIS AFTN THEN INTO CNTRL WY BY THIS EVG XCPT
INCRS SW WNDS BHND THE LOW ESPCLY ON WED AS THE LOW REACHS THE XTRM
N-NE BY 12Z. MAIN CHG TO FCST WILL BE TO BUMP UP POPS INTO HIGH SCT
RNG FOR THIS EVG. FOR WED THE UPR RDG STARTS BLDG FM THE SW AND WILL
GO WITH ONLY ISOLD SHWRS OVR THE CNTRL-SW WITH SCT TSTMS OVR THE
N-NE-E AND SCT SHWRS NW. FOR THUR THE RDG CONTS TO BLD OVR THE FCST
AREA AND WILL GO WITH ONLY ISOLD PM TSTMS HIGHER TRRN. AS FOR TMPS
WED WILL UNDERCUT GUICDANCE SM AND CONT TMPS SMLR TO TODAY OR A LTL
WARMER...AND THEN FOR THUR A FEW DEGS WARMER. XTNDD FCST ON TRAK WITH
HOT AND DRY WITH SLGHT CHC PM TSTMS MAINLY HIGHER TRRN AS RDG CONTS
TO BLD OVR THE CNTRL RCKYS. RWM

.RIW...NONE.

In the hours before

Special weather statement, Jun 26, 5:00 PM MDT, 2 hours 13 minutes before
WYZ002-004-005-008-009-013-015-026>028-270000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
500 PM MDT TUE JUN 26 2001

...A TORNADO WATCH HAS BEEN ISSUED FOR PARTS OF CENTRAL AND
NORTHERN WYOMING UNTIL 1100 PM MDT...

...STRONG THUNDERSTORMS OVER CENTRAL NATRONA AND NORTHEAST FREMONT
COUNTY...

AT 455 PM MDT...RIVERTON DOPPLER RADAR SHOWED STRONG THUNDERSTORMS
OVER CENTRAL NATRONA COUNTY NEAR THE COMMUNITY OF NATRONA...AND OVER
NORTHEAST FREMONT COUNTY NEAR BOYSEN RESERVOIR.  THESE STORMS
WERE MOVING NORTH AT BETWEEN 15 AND 20 MPH.  FREQUENT LIGHTNING...
GUSTY WINDS...BRIEF HEAVY RAIN...AND HAIL MAY ACCOMPANY THESE
STORMS.

THE AIRMASS OVER CENTRAL AND NORTHERN WYOMING IS VERY MOIST AND
UNSTABLE THIS EVENING...AND THE STORMS OVER NATRONA AND NORTHEAST
FREMONT COUNTY WILL LIKELY INTENSIFY AS THEY MOVE NORTH INTO
NORTHERN WYOMING. THE COUNTIES IN THE TORNADO WATCH AREA INCLUDE
EASTERN PARK...BIG HORN...HOT SPRINGS...WASHAKIE...JOHNSON AND
NATRONA.

CONTINUE TO LISTEN TO THIS STATION FOR LATER STATEMENTS AND
POSSIBLE WARNINGS.

DN

WCJIN-WYNW-WYNE
Local storm report, Jun 26, 5:20 PM MDT, 1 hour 53 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RIVERTON, WY
520 PM MDT TUE JUN 26 2001

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0316 PM    ALCOVA                    WY   FUNNEL CLOUD
06/26/01   NATRONA                        REPORTED BY PUBLIC

0320 PM    5 N ALCOVA                WY   FUNNEL CLOUD
06/26/01   NATRONA

0322 PM    3 N ALCOVA                WY   FUNNEL CLOUD
06/26/01   NATRONA                        REPORTED BY SPOTTERS

0324 PM    3 NW ALCOVA               WY   FUNNEL CLOUD
06/26/01   NATRONA

0325 PM    3 N ALCOVA                WY   FUNNEL CLOUD
06/26/01   NATRONA                        REPORTED BY SPOTTERS

0343 PM    13-18 WSW CASPER          WY   FUNNEL CLOUD
06/26/01   NATRONA

0345 PM    40 SW CASPER              WY   .75 INCH HAIL
06/26/01   NATRONA

MLC
Local storm report, Jun 26, 6:23 PM MDT, 50 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RIVERTON, WY
623 PM MDT TUE JUN 26 2001

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0545 PM    6 SE THERMOPOLIS          WY   WIND DAMAGE
06/26/01   HOT SPRINGS                    1"-2" TREE BRANCHES
                                          DOWN FROM WIND.
                                          ESTIMATED WIND GUST
         |                                 OF 60 MPH.

MLC
Local storm report, Jun 26, 6:57 PM MDT, 16 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RIVERTON, WY
657 PM MDT TUE JUN 26 2001

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0655 PM    1 S GREYBULL              WY   TORNADO
06/26/01   BIG HORN

0656 PM    1 W GREYBULL              WY   TORNADO
06/26/01   BIG HORN

MLC
Local storm report, Jun 26, 7:05 PM MDT, 8 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RIVERTON, WY
705 PM MDT TUE JUN 26 2001

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0702 PM    1/2 S GREYBULL            WY   .75 INCH HAIL
06/26/01   BIG HORN
Local storm report, Jun 26, 7:13 PM MDT, 0 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RIVERTON, WY
713 PM MDT TUE JUN 26 2001

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0653 PM    1 W GREYBULL              WY   TORNADO
06/26/01   BIG HORN

0707 PM    1 E GREYBULL              WY   FUNNEL CLOUD
06/26/01   BIG HORN

0642 PM    10 SW BASIN               WY   FUNNEL CLOUD
06/26/01   BIG HORN

MLC

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 26, 6:50 PM MDTTornado WarningRIWBig Horn25 min
Jun 26, 7:15 PM MDTTornado WarningRIWBig Horn45 min
Jun 27, 2:05 PM MDTSevere Thunderstorm WarningRIWBig Horn, Washakie40 min
Jun 27, 2:28 PM MDTSevere Thunderstorm WarningRIWHot Springs, Washakie32 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2001Every severe thunderstorm warning in 2001

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.