Alert archive / Wyoming / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 90, NWS Cheyenne, WY

July 1, 1998Niobrara County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 1, 1998, 10:01 PM MDT for Niobrara County, Wyoming. It was in force for 44 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, 10:01 PM MDT (04:01 UTC)
Expired
Jul 1, 1998, 10:45 PM MDT
In force
44 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Niobrara County, WY

The radar

The Rapid City radar (KUDX), 178 km from the middle of the area, began a volume at 04:04 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.

The nearest sounding before it

Rapid City, SD (KUNR), launched 00:00Z, 4.0 hours before the alert went out and 171 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 00:00Z on 1998-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1135 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 1998-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 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
1135 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
1329 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
0.5
Supercell composite
8.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KCYS 020401 RRA
SVRCYS
WYC027-020445-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
1001 PM MDT WED JUL 1 1998

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN NIOBRARA COUNTY IN EASTERN WYOMING

* UNTIL 1045 PM MDT

* AT 955 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 40 MILES NORTH OF LUSK...OR 10 MILES NORTHWEST
  OF REDBIRD...MOVING EAST AT 10 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  REDBIRD BY 1040 PM MDT
  MULE CREEK JUNCTION BY 1040 MDT

DAMAGING WINDS AND HEAVY RAIN ARE LIKELY. GO INSIDE A STURDY
BUILDING AND STAY AWAY FROM WINDOWS!  THE SLOW MOVEMENT OF THIS STORM
MAY CAUSE SOME LOCALIZED FLOODING.

WCJIN-WYNE
SULLIVAN

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 7:10 PM MDTSevere Thunderstorm WarningCYSConverse60 min
Jul 1, 7:59 PM MDTTornado WarningCYSConverse31 min
Jul 1, 8:30 PM MDTSevere Thunderstorm WarningCYSConverse60 min
Jul 1, 9:22 PM MDTFlash Flood WarningCYSConverse6 hr
Jul 1, 9:33 PM MDTSevere Thunderstorm WarningCYSConverse47 min
Jul 2, 3:47 PM MDTTornado WarningCYSAlbany28 min
Jul 2, 3:53 PM MDTSevere Thunderstorm WarningCYSAlbany47 min
Jul 2, 4:35 PM MDTSevere Thunderstorm WarningCYSLaramie45 min
Jul 2, 4:54 PM MDTSevere Thunderstorm WarningCYSLaramie41 min
Jul 2, 5:31 PM MDTSevere Thunderstorm WarningCYSLaramie49 min
Jul 2, 5:51 PM MDTSevere Thunderstorm WarningCYSGoshen49 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 1998Every severe thunderstorm warning 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; radar from the NEXRAD Level II archive.