Alert archive / Wyoming / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 62, NWS Cheyenne, WY
NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 9, 1998, 12:57 PM MDT for Platte County, Wyoming. It was in force for 33 min. 1 report 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
- Jun 9, 1998, 12:57 PM MDT (18:57 UTC)
- Expired
- Jun 9, 1998, 1:30 PM MDT
- In force
- 33 min
- Issued by
- NWS Cheyenne, WY
- Area
- Whole counties
County Platte County, WY
The radar
The Cheyenne radar (KCYS), 110 km from the middle of the area, began a volume at 18:56 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jun 9, 1:04 PM MDT | Tornado F0 | Chugwater, WY | A tornado moved across open country south of Chugwater and dissipated. The sheriffs office said that the tornado only churned up some grass and dirt. A pilot who was flying 25 miles northwest of Cheyenne also observed the tornado on the ground. |
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 nearest sounding before it
Rapid City, SD (KUNR), launched 12:00Z, 7.0 hours before the alert went out and 274 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 630 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- -19 m²/s²
- 0-3 km storm-relative helicity
- 102 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
161 WUUS1 KCYS 091859 RRA SVRCYS WYC031-091930- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE CHEYENNE WY 1257 PM MDT TUE JUN 9 1998 THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHERN PLATTE COUNTY IN SOUTHEASTERN WYOMING * UNTIL 130 PM MDT * AT 1255 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 25 MILES SOUTHWEST OF CHUGWATER... MOVING EAST AT 20 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... ONLY OPEN COUNTRY DAMAGING WINDS AND LARGE HAIL ARE LIKELY. GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS PAL WCJIN-WYSE
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
In the hours before
Special weather statement, Jun 9, 9:25 AM MDT, 3 hours 32 minutes before
WYZ061>066-100000- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHEYENNE WY 925 AM MDT MON JUN 9 1998 THERE IS A SLIGHT CHANCE FOR SEVERE THUNDERSTORMS OVER SOUTHEAST AND EAST CENTRAL WYOMING INTO THE NEBRASKA PANHANDLE TODAY. SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON. DISCUSSION...A MOIST SOUTH TO SOUTHEAST FLOW CONTINUED TO PROVIDE ABUNDANT LOW LEVEL MOISTURE OVER THE HIGH PLAINS OF WYOMING AND THE NEBRASKA PANHANDLE. A WEAK UPPER LEVEL DISTURBANCE IS EXPECTED TO MOVE INTO THE AREA THIS AFTERNOON AND COMBINE WITH DAYTIME HEATING TO DESTABILIZE THE AIR MASS. STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP AMD MOVE NORTHEAST ACROSS THE COUNTY WARNING AREA DURING THE AFTERNOON INTO THIS EVENING. A FEW STORMS MAY BECOME SEVERE PRODUCING LARGE HAIL AND DAMAGING. WCJIN-WYSE-WYNE PAL
The office that day
Everything else NWS Cheyenne, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 9, 1:07 PM MDT | Tornado Warning | CYS | Platte | 33 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.