Alert archive / Wyoming / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 83, NWS Cheyenne, WY

July 11, 1997Niobrara County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 11, 1997, 5:53 PM MDT for Niobrara County, Wyoming. It was in force for 62 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 11, 1997, 5:53 PM MDT (23:53 UTC)
Expired
Jul 11, 1997, 6:55 PM MDT
In force
62 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 23:57 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 12:00Z, 11.9 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 12:00Z on 1997-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1017 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 12:00Z on 1997-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
1017 J/kg
Mixed-layer CIN
-301 J/kg
Mixed-layer LCL
1583 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
31 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 KCYS 112353 RRA
SVRCYS
WYC027-120055-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
553 PM MDT FRI JUL 11 1997

* SEVERE THUNDERSTORM WARNING FOR
  CENTRAL NIOBRARA COUNTY IN EASTERN WYOMING

* UNTIL 655 PM MDT

* THIS STORM IS EXPECTED TO REMAIN IN RURAL AREAS.

* AT 550 PM MDT...A SEVERE THUNDERSTORM WAS INDICATED BY DOPPLER
  RADAR 25 MILES NORTH OF LUSK OR 6 MILES NORTH OF LANCE CREEK MOVING
  EAST AT 810 MPH.
 
 
LARGE HAIL IS LIKELY WITH THIS STORM.  SEEK SHELTER INSIDE A STURDY
BUILDING AWAY FROM ALL WINDOWS UNTIL THE STORM PASSES.

WCJIN-WYNE

PAL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 4:50 PM MDTSevere Thunderstorm WarningCYSConverse, Niobrara60 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 1997Every severe thunderstorm warning in 1997

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.