Alert archive / Wyoming / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 4, NWS Riverton, WY
NWS Riverton, WY issued this severe thunderstorm warning at Jun 1, 1997, 7:36 PM MDT for Natrona County, Wyoming. It was in force for 49 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
- Jun 1, 1997, 7:36 PM MDT (01:36 UTC)
- Expired
- Jun 1, 1997, 8:25 PM MDT
- In force
- 49 min
- Issued by
- NWS Riverton, WY
- Area
- Whole counties
County Natrona County, WY
The radar
The Riverton/Lander radar (KRIW), 137 km from the middle of the area, began a volume at 01:40 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jun 1, 2:45 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Riverton, WY (KRIW), launched 00:00Z, 1.6 hours before the alert went out and 131 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
- 157 J/kg
- Mixed-layer CIN
- -32 J/kg
- Mixed-layer LCL
- 2187 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 79 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
251 WUUS01 KRIW 020139 RRA SVRRIW WYC025-020225- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE RIVERTON WY 736 PM MDT SUN JUN 1 1997 * SEVERE THUNDERSTORM WARNING FOR EASTERN NATRONA COUNTY - EAST CENTRAL WYOMING * UNTIL 825 PM MDT * SOME LOCATIONS AFFECTED INTERSTATE 25 EAST OF CASPER * AT 735 PM MDT RADAR INDICATED A SEVERE THUNDERSTORM 5 MILES SOUTHWEST OF CASPER MOVING NORTH 25 MPH. * THE STORM WILL BE OVER INTERSTATE 25 EAST OF CASPER AT 745 PM MDT. WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A STRONG BUILDING. DO NOT STAND BY WINDOWS. DO NOT USE TELEPHONES OR ELECTRICAL APPLIANCES UNLESS IN AN EMERGENCY UNTIL THE STORM HAS PASSED. MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS. WCJIN-WYNE KAISER
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.
NWS Riverton, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 1, 2:41 PM MDT, 4 hours 55 minutes earlier.
Area forecast discussion, Jun 1, 2:41 PM MDT, 4 hours 55 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 240 AM MDT SUN JUNE 01 1997 MAIN FCST PRBLM INVOLVES THE INTENSITY OF THE THUNDERSTORMS OVER THE EAST HALF OF WY AND THE EASTERN PORTION OF THE CWFA. RIW 88-D INDICATING TSRA VCNTY OF JFRY CITY AND S JOHNSON CO. AS THESE STORMS MOVE EAST FROM DEWPOINTS IN THE 40S TO THE 50S VCNTY OF CPR...THESE STORMS SHOULD BLOSSOM INTO STORMS ATLEAST APPROACHING SEVERE. SO FAR WE HAVE RECEIVED REPORTS OF PEA SIZE HAIL FROM S JOHNSON CO FROM STORMS WITH VILS MOSTLY IN THE 40S AND 60 DBZ. WITH IMPRESSIVE VV...SFC CONVERGENCE...THETA E RIDGE ...AND LIFTED INDICES BETWEEN -4 AND -6 OVER EASTERN WY...ANY STORMS MOVING EAST INTO THAT REGION WILL INTENSIFY. WOULD EXPECT STORMS TO APPROACH SEVERE LEVELS IN EXTREME E PORTION OF CWFA LATE THIS AFT/EVE. ACTIVITY HAS QUIETED DOWN OVER CENTRAL AND WESTERN WY AS COLD FRONT CONTINUES TO SLIDE SE. LIFTED INDICES BETWEEN -2 AND ZERO WITH SFC DIV THERE. PREFER ETA SOLN OVER FASTER NGM/AVN BASED ON ETA HANDLING OF TIMING OF ASCT SHORT WAVE SO FAR. ETA STARTS A WEAK LOW LEVEL CIRCULATION OVER N CENTRAL CO AND SE WY BY 00Z MON. GUIDANCE TURNS WINDS MORE N AND NE AND LOWERS CEILINGS AROUND 00Z MON IN RESPONSE TO THIS. WOULD EXPECT MORE EXTENSIVE CLOUDINESS AND LIGHTER SHOWERS TO CONTINUE TONIGHT. VERY WEAK SHORT WAVE AND ASCT INCR POCKET OF 500- 800MB LYR AVE MSTR MOVES THR*OUGH MON SO WOULD CONT SCT TSRA MON AFT BUT MORE GARDEN VARIETY WITH MORE CAA AT LOWER LEVELS STABILIZING AIRMASS SOMEWHAT. AGREE WITH FWC TEMPS TAKING INTO CONSIDERATION CAA AND CLOUDINESS. LIPSON
In the hours before
Special weather statement, Jun 1, 3:51 PM MDT, 3 hours 45 minutes before
WYZ015-022>025-027-028-012250- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 350 PM MDT SUN JUN 1 1997 ...THUNDERSTORMS CONTINUE TO DEVELOP OVER SOUTHERN AND EAST CENTRAL WYOMING... AT 340 PM MDT RIVERTON WEATHER RADAR INDICATED STRONG THUNDERSTORMS CONTINUING TO MOVE EAST ACROSS SOUTHEAST JOHNSON COUNTY IN THE VICINITY OF LINCH. ANOTHER CLUSTER OF THUNDERSTORMS WAS LOCATED OVER SOUTHERN NATRONA COUNTY IN THE VICINITY OF ALCOVA RESERVOIR. A NEW CLUSTER OF THUNDERSTORMS HAS ALSO FORMED OVER EASTERN SWEETWATER COUNTY. THESE STORMS ARE MOVING EAST AT 20 TO 30 MPH AND SHOULD BE AFFECTING CASPER MOUNTAIN WITHIN THE HOUR. SMALL HAIL...FREQUENT LIGHTNING...BRIEF HEAVY RAIN AND AND STRONG GUSTY WINDS CAN BE EXPECTED WITH SOME OF THESE STORMS. PEOPLE OUT ON ALCOVA RESERVOIR SHOULD HEAD TO SHORE EMMEDIATELY AND MOVE TO A PLACE OF SAFETY AT THE FIRST SIGN OF THREATENING WEATHER SUCH AS...TOWERING THUNDERHEADS...DARKENING SKIES...LIGHTNING AND INCREASING WINDS. TUNE IN NOAA WEATHER RADIO OR YOUR LOCAL RADIO OR TV STATION FOR THE LATEST WEATHER INFORMATION. WCJIN-WYSW-WYNE LIPSON
Special weather statement, Jun 1, 5:20 PM MDT, 2 hours 16 minutes before
WYZ013>015-022>028-020100- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 520 PM MDT SUN JUN 1 1997 ...SEVERE THUNDERSTORM WATCH FOR NATRONA COUNTY UNTIL 9 PM... ...STRONG THUNDERSTORMS ACROSS SOUTHWEST WYOMING... AT 515 PM WEATHER RADAR IN RIVERTON CONTINUED TO SHOW STRONG THUNDERSTORMS ACROSS MOST OF SWEETWATER COUNTY. THE STRONGEST STORMS WERE ABOUT 5 MILES NORTHWEST OF WAMSUTTER. THE STORMS WERE MOVING NORTHEAST AT 30 MPH. THESE STORMS WERE PRODUCING EXTENSIVE DANGEROUS CLOUD TO GROUND LIGHTNING...SMALL HAIL AND HEAVY DOWNPOURS. THE STORMS WILL LIKELY MOVE THROUGH SOUTHEASTERN FREMONT COUNTY AND THROUGH JEFFREY CITY BY 630 PM AND THEN INTO SOUTHERN NATRONA COUNTY. THUNDERSTORMS WILL CONTINUE THROUGH MUCH OF THE EVENING ACROSS CENTRAL AND SOUTHWEST WYOMING. IF THREATENING WEATHER APPROACHES YOUR AREA SEEK SHELTER IMMEDIATELY. ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON NOAA WEATHER RADIO...LOCAL CABLE TELEVISION OR ON THE INTERNET AT HTTP://RIW.WEATHER.WYOMING.COM WCJIN-WYSW-WYNE-WYNW GK
Special weather statement, Jun 1, 5:22 PM MDT, 2 hours 14 minutes before
WYZ013>015-022>028-020100- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 520 PM MDT SUN JUN 1 1997 ...SEVERE THUNDERSTORM WATCH FOR NATRONA COUNTY UNTIL 9 PM... ...STRONG THUNDERSTORMS ACROSS SOUTHWEST WYOMING... AT 515 PM WEATHER RADAR IN RIVERTON CONTINUED TO SHOW STRONG THUNDERSTORMS ACROSS MOST OF SWEETWATER COUNTY. THE STRONGEST STORMS WERE ABOUT 5 MILES NORTHWEST OF WAMSUTTER. THE STORMS WERE MOVING NORTHEAST AT 30 MPH. THESE STORMS WERE PRODUCING EXTENSIVE DANGEROUS CLOUD TO GROUND LIGHTNING...SMALL HAIL AND HEAVY DOWNPOURS. THE STORMS WILL LIKELY MOVE THROUGH SOUTHEASTERN FREMONT COUNTY AND THROUGH JEFFREY CITY BY 630 PM AND THEN INTO SOUTHERN NATRONA COUNTY. THUNDERSTORMS WILL CONTINUE THROUGH MUCH OF THE EVENING ACROSS CENTRAL AND SOUTHWEST WYOMING. IF THREATENING WEATHER APPROACHES YOUR AREA SEEK SHELTER IMMEDIATELY. ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON NOAA WEATHER RADIO...LOCAL CABLE TELEVISION OR ON THE INTERNET AT HTTP://RIW.WEATHER.WYOMING.COM WCJIN-WYSW-WYNE-WYNW GK
Special weather statement, Jun 1, 6:20 PM MDT, 1 hour 16 minutes before
WYZ015-020130- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 620 PM MDT SUN JUN 1 1997 ...SEVERE THUNDERSTORM WATCH FOR NATRONA COUNTY UNTIL 9 PM... ...LINE OF STRONG THUNDERSTORMS APPROACHING NATRONA COUNTY FROM THE SOUTH... AT 615 PM WEATHER RADAR IN RIVERTON SHOWED A LINE OF STRONG THUNDERSTORMS IN NORTHERN CARBON COUNTY MOVING NORTHEAST AT 15 TO 20 MPH. THE STORMS WILL BE IN THE PATHFINDER DAM AND ALCOVA RESERVOIR AREAS BY 7 PM. EXPECT SMALL HAIL AND EXTENSIVE DANGEROUS CLOUD TO GROUND LIGHTNING WITH THESE STORMS AS WELL AS WIND GUSTS APPROACHING 50 MPH. PERSONS OUTDOORS THIS AFTERNOON IN THE ALCOVA AND PATHFINDER AREAS SHOULD SEEK SHELTER IMMEDIATELY. THESE STORMS WILL ALSO LIKELY AFFECT THE CITY OF CASPER AS WELL. EVERYONE IN NATRONA COUNTY SHOULD BE AWARE OF THE POTENTIAL FOR STRONG THUNDERSTORMS THIS EVENING. SOME OF THE STORMS MAY BECOME SEVERE. SO KEEP ABREAST OF THE LATEST WEATHER INFORMATION AND THE PROGRESS OF THUNDERSTORMS THIS EVENING. ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON NOAA WEATHER RADIO...LOCAL CABLE TELEVISION OR ON THE INTERNET AT HTTP://RIW.WEATHER.WYOMING.COM WCJIN-WYSW-WYNE GK
Special weather statement, Jun 1, 6:23 PM MDT, 1 hour 13 minutes before
WYZ015-020130- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 620 PM MDT SUN JUN 1 1997 ...SEVERE THUNDERSTORM WATCH FOR NATRONA COUNTY UNTIL 9 PM... ...LINE OF STRONG THUNDERSTORMS APPROACHING NATRONA COUNTY FROM THE SOUTH... AT 615 PM WEATHER RADAR IN RIVERTON SHOWED A LINE OF STRONG THUNDERSTORMS IN NORTHERN CARBON COUNTY MOVING NORTHEAST AT 15 TO 20 MPH. THE STORMS WILL BE IN THE PATHFINDER DAM AND ALCOVA RESERVOIR AREAS BY 7 PM. EXPECT SMALL HAIL AND EXTENSIVE DANGEROUS CLOUD TO GROUND LIGHTNING WITH THESE STORMS AS WELL AS WIND GUSTS APPROACHING 50 MPH. PERSONS OUTDOORS THIS AFTERNOON IN THE ALCOVA AND PATHFINDER AREAS SHOULD SEEK SHELTER IMMEDIATELY. THESE STORMS WILL ALSO LIKELY AFFECT THE CITY OF CASPER AS WELL. EVERYONE IN NATRONA COUNTY SHOULD BE AWARE OF THE POTENTIAL FOR STRONG THUNDERSTORMS THIS EVENING. SOME OF THE STORMS MAY BECOME SEVERE. SO KEEP ABREAST OF THE LATEST WEATHER INFORMATION AND THE PROGRESS OF THUNDERSTORMS THIS EVENING. ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON NOAA WEATHER RADIO...LOCAL CABLE TELEVISION OR ON THE INTERNET AT HTTP://RIW.WEATHER.WYOMING.COM WCJIN-WYSW-WYNE GK
Special weather statement, Jun 1, 7:30 PM MDT, 6 minutes before
WYZ015-020230- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 730 PM MDT SUN JUN 1 1997 ...SEVERE THUNDERSTORM WATCH FOR NATRONA COUNTY UNTIL 9 PM... ...STRONG THUNDERSTORMS DEVELOPING THROUGHOUT NATRONA COUNTY... AT 725 PM WEATHER RADAR IN RIVERTON SHOWED SEVERAL STRONG THUNDERSTORMS THROUGHOUT NATRONA COUNTY. THE STRONGEST WAS ABOUT 8 MILES TO THE SOUTHEAST OF CASPER. OTHER STRONG STORMS WERE 2 MILES WEST OF ALCOVA RESERVOIR AND IN THE EXTREME SOUTHWEST CORNER OF THE COUNTY. OTHER STORMS HAD DEVELOPED ALONG ROUTE 26 EAST OF NATRONA. THESE STORMS WILL LIKELY PRODUCE SMALL HAIL...HEAVY RAIN...WIND GUSTS APPROACHING 50 MPH AND EXTENSIVE CLOUD TO GROUND LIGHTNING. EVERYONE IN NATRONA COUNTY SHOULD BE AWARE OF THE POTENTIAL FOR STRONG THUNDERSTORMS THIS EVENING. SOME OF THE STORMS MAY BECOME SEVERE. SO KEEP ABREAST OF THE LATEST WEATHER INFORMATION IN THE EVENT WARNINGS ARE ISSUED LATER THIS EVENING. ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON NOAA WEATHER RADIO...LOCAL CABLE TELEVISION OR ON THE INTERNET AT HTTP://RIW.WEATHER.WYOMING.COM WCJIN-WYSW-WYNE GK
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.