Alert archive / Nebraska / Tornado Warnings in 1990

Tornado Warning 5, NWS Cheyenne, WY

May 18, 1990Sioux County, Nebraska

NWS Cheyenne, WY issued this tornado warning at May 18, 1990, 4:00 PM MDT for Sioux County, Nebraska. It was in force for 60 min.

The area

The counties it named.

The facts

Issued
May 18, 1990, 4:00 PM MDT (22:00 UTC)
Expired
May 18, 1990, 5:00 PM MDT
In force
60 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Sioux County, NE

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 10.0 hours before the alert went out and 190 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, Rapid City, SD at 12:00Z on 1990-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 12:00Z on 1990-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 291 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1613 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
291 m²/s²
0-3 km storm-relative helicity
636 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.

000 
TTAA00 KBFF 182200
TORBFF
NEC165-182300-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING 
NATIONAL WEATHER SERVICE SCOTTSBLUFF NE
400 PM MDT FRI MAY 18 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 500 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTY

   IN THE PANHANDLE OF NEBRASKA
      SIOUX

AT 358 PM MDT A TORNADO WAS INDICATED BY RADAR 38 MILES NORTHWEST
OF SCOTTSBLUFF NEBRASKA...OR 15 MILES SOUTH OF HARRISON IN SIOUX
COUNTY NEAR THE NIOBRARA RIVER.  THE STORM WAS MOVING TO THE EAST
AND NORTHEAST AROUND 25 MILES AN HOUR.

TAKE SHELTER IN A BASEMENT IF AVAILABLE.  OTHERWISE GO TO A SMALL
INTERIOR ROOM ON THE LOWEST FLOOR.  STAY AWAY FROM WINDOqWS.  ABANDON
CARS AND MOBILE HOMES.

IF YOU ARE CAUGHT OUTSIDE...FIND SHELTER IN A NEARBY REINFORCED
BUILDING.  AS A LAST RESORT...TAKE SHELTER IN A CULVERT...DITCH OR
LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

PFEIFFER

The office that day

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

IssuedProductOfficeCountiesLasted
May 18, 3:43 PM MDTSevere Thunderstorm WarningCYSSioux62 min
May 18, 4:11 PM MDTSevere Thunderstorm WarningCYSBox Butte, Dawes64 min
May 18, 4:52 PM MDTTornado WarningCYSMorrill68 min
May 18, 5:23 PM MDTSevere Thunderstorm WarningCYSBox Butte, Dawes, Sheridan67 min
May 18, 5:52 PM MDTTornado WarningCYSSheridan38 min

Nearby

Tornado Warnings in Nebraska, 1990Every tornado warning in 1990Tornadoes in 1990

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.