Alert archive / Wyoming / Tornado Warnings in 2001

Tornado Warning 4, NWS Riverton, WY

July 4, 2001Johnson County, Wyoming

NWS Riverton, WY issued this tornado warning at Jul 4, 2001, 2:43 PM MDT for Johnson County, Wyoming. It was in force for 32 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 4, 2001, 2:43 PM MDT (20:43 UTC)
Expired
Jul 4, 2001, 3:15 PM MDT
In force
32 min
Issued by
NWS Riverton, WY
Area
Whole counties

County Johnson County, WY

What was reported inside it

TimeReportWhereRemark
Jul 4, 3:10 PM MDTHail 0.88Sussex, WY
Jul 4, 3:25 PM MDTHail 0.88Sussex, WY

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

IssuedProductOfficeLasted
Jul 4, 2:15 PM MDTTornado WatchSPC7 hr

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 8.7 hours before the alert went out and 182 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 12:00Z on 2001-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 271 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 12:00Z on 2001-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -60 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
271 J/kg
Mixed-layer CIN
-288 J/kg
Mixed-layer LCL
1924 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-60 m²/s²
0-3 km storm-relative helicity
89 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.

000 
WFUS55 KRIW 042044
TORRIW

WYC019-042115-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE RIVERTON WY
243 PM MDT WED JUL 4 2001

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN JOHNSON COUNTY IN NORTH CENTRAL WYOMING

* UNTIL 315 PM MDT

* AT 243 PM MDT...LOCAL LAW ENFORCEMENT REPORTED A SEVERAL FUNNEL 
CLOUDS 15 MILES NORTH OF SUSSEX...OR ABOUT 36 MILES SOUTHEAST OF 
BUFFALO.  THIS THUNDERSTORM WILL LIKELY PRODUCE A TORNADO.  DOPPLER 
RADAR INDICATED THE ASSOCIATED STORM MOVING SOUTHEAST AT 45 MPH.

* THE TORNADO IS EXPECTED TO BE...
  12 MILES NORTHEAST OF SUSSEX AROUND 250 PM MDT

THIS TORNADO WARNING REPLACES THE SEVERE THUNDERSTORM WARNING
PREVIOUSLY ISSUED FOR THE WARNED AREA.

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY STURDY BUILDING.
AS A LAST RESORT...SEEK REFUGE IN A CULVERT...DITCH OR LOW SPOT AND
COVER YOUR HEAD WITH YOUR HANDS. BEWARE OF THE THREAT OF RISING
WATER.

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

$$
LAT...LON 4418 10608 4383 10659 4351 10643 4356 10607

C. BAKER

WCJIN-WYNE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 2:06 PM MDTSevere Thunderstorm WarningRIWJohnson24 min
Jul 4, 2:30 PM MDTSevere Thunderstorm WarningRIWJohnson30 min
Jul 4, 2:44 PM MDTSevere Thunderstorm WarningRIWFremont, Hot Springs31 min
Jul 4, 3:15 PM MDTSevere Thunderstorm WarningRIWJohnson30 min
Jul 4, 3:45 PM MDTSevere Thunderstorm WarningRIWJohnson30 min
Jul 4, 4:30 PM MDTSevere Thunderstorm WarningRIWFremont30 min
Jul 4, 5:06 PM MDTSevere Thunderstorm WarningRIWJohnson29 min

Nearby

Tornado Warnings in Wyoming, 2001Every tornado warning in 2001Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.