Alert archive / Wyoming / Tornado Warnings in 1998

Tornado Warning 4, NWS Riverton, WY

July 1, 1998Big Horn County, Wyoming

NWS Riverton, WY issued this tornado warning at Jul 1, 1998, 4:17 PM MDT for Big Horn County, Wyoming. It was in force for 33 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
Jul 1, 1998, 4:17 PM MDT (22:17 UTC)
Expired
Jul 1, 1998, 4:50 PM MDT
In force
33 min
Issued by
NWS Riverton, WY
Area
Whole counties

County Big Horn County, WY

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 10.3 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 12:00Z on 1998-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 155 joules per kilogram.LCLLFCEL10008507005003002001001 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 12:00Z on 1998-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 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
155 J/kg
Mixed-layer CIN
-230 J/kg
Mixed-layer LCL
1484 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
274 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

703 
WFUS01 KRIW 012218
TORRIW
WYC003-012250-

BULLETIN - EAS ACTIVATION
TORNADO WARNING
NATIONAL WEATHER SERVICE RIVERTON WY
417 PM MDT WED JUL 1 1998

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHWESTERN AND SOUTH CENTRAL BIG HORN COUNTY IN NORTH CENTRAL
  WYOMING

* UNTIL 450 PM MDT

* AT 415 PM... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 5 MILES WEST OF BASIN AND MANDERSON... MOVING EAST AT 25 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  BASIN AND MANDERSON AT 422 PM

GO TO THE BASEMENT OR A SMALL INTERIOR ROOM ON THE LOWEST FLOOR

DO NOT USE YOUR CAR TO OUTRUN A TORNADO. CARS ARE EASILY TOSSED
AROUND BY TORNADIC WINDS. IF YOU ARE CAUGHT IN THE PATH OF A
TORNADO... LEAVE THE CAR AND GO TO A STRONG BUILDING. IF NO
STRUCTURE IS NEARBY...SEEK SAFETY IN A DITCH OR LOW SPOT. BE
MINDFUL OF RISING WATERS.

WCJIN-WYNW
RWM

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 6:04 PM MDTSevere Thunderstorm WarningRIWHot Springs31 min
Jul 1, 2:34 PM MDTSevere Thunderstorm WarningRIWPark31 min
Jul 1, 3:00 PM MDTSevere Thunderstorm WarningRIWPark30 min
Jul 1, 3:28 PM MDTSevere Thunderstorm WarningRIWBig Horn32 min
Jul 1, 3:54 PM MDTSevere Thunderstorm WarningRIWWashakie41 min
Jul 1, 4:03 PM MDTSevere Thunderstorm WarningRIWBig Horn47 min
Jul 1, 4:43 PM MDTSevere Thunderstorm WarningRIWWashakie27 min
Jul 1, 5:16 PM MDTSevere Thunderstorm WarningRIWWashakie44 min

Nearby

Tornado Warnings in Wyoming, 1998Every tornado warning in 1998Tornadoes in 1998

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.