Alert archive / Wyoming / Severe Thunderstorm Warnings in 2018
Severe Thunderstorm Warning 66, NWS Riverton, WY
NWS Riverton, WY issued this severe thunderstorm warning at Jul 17, 2018, 2:20 PM MDT for Johnson County, Wyoming. It was in force for 40 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 17, 2018, 2:20 PM MDT (20:20 UTC)
- Expired
- Jul 17, 2018, 3:00 PM MDT
- In force
- 40 min
- Issued by
- NWS Riverton, WY
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
County Johnson County, WY
The radar
The Riverton/Lander radar (KRIW), 187 km from the middle of the area, began a volume at 20:22 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
Riverton, WY (KRIW), launched 12:00Z, 8.3 hours before the alert went out and 182 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
- 90 J/kg
- Mixed-layer CIN
- -338 J/kg
- Mixed-layer LCL
- 1461 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 25 m²/s²
- 0-3 km storm-relative helicity
- 116 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 Jul 17, 11:59 AM MDT, 2 hours 21 minutes earlier.
Area forecast discussion, Jul 17, 11:59 AM MDT, 2 hours 21 minutes before
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</html>Hazardous weather outlook, Jul 17, 1:34 AM MDT, 12 hours 46 minutes before
Hazardous Weather Outlook National Weather Service Riverton WY 134 AM MDT Tue Jul 17 2018 WYZ001>020-022>030-181200- Yellowstone National Park-Absaroka Mountains-Cody Foothills- North Big Horn Basin-Southwest Big Horn Basin- Southeast Big Horn Basin-Owl Creek and Bridger Mountains- Bighorn Mountains West-Bighorn Mountains Southeast- Northeast Johnson County-Southeast Johnson County- Teton and Gros Ventre Mountains-Jackson Hole- Wind River Mountains West-Wind River Mountains East- Upper Wind River Basin-Wind River Basin-Lander Foothills- Green Mountains and Rattlesnake Range- Natrona County Lower Elevations-Casper Mountain-Star Valley- Salt River and Wyoming Ranges-Upper Green River Basin Foothills- Upper Green River Basin-South Lincoln County- Rock Springs and Green River-Flaming Gorge-East Sweetwater County- 134 AM MDT Tue Jul 17 2018 This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and Tonight Isolated to widely scattered thunderstorms; most numerous in northern and eastern areas. Hail and heavy rain are the main threats. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Saturday and Sunday...Isolated thunderstorms, mainly in the afternoon and evening hours. Monday...Isolated late day thunderstorms, mainly along and east of the divide. .SPOTTER INFORMATION STATEMENT... Spotters are urged to report hail, wind gusts over 45 mph and heavy rainfall. Thank you.
In the hours before
Local storm report, Jul 17, 12:36 PM MDT, 1 hour 44 minutes before
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<div class="status" id="status">Temporary Notice</div>
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</html>Special weather statement, Jul 17, 1:37 PM MDT, 43 minutes before
Special Weather Statement National Weather Service Riverton WY 137 PM MDT TUE JUL 17 2018 WYZ003-004-172015- North Big Horn Basin-Cody Foothills- 137 PM MDT TUE JUL 17 2018 ...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL PARK COUNTY UNTIL 215 PM MDT... At 137 PM MDT, Doppler radar was tracking a strong thunderstorm 7 miles southwest of Ralston, or 9 miles northeast of Cody, moving east at 15 mph. Dime size hail and winds in excess of 40 mph will be possible with this storm. This strong thunderstorm will be near... Ralston around 155 PM MDT. Other locations impacted by this storm include Park County Fairgrounds and Northwest College. PRECAUTIONARY/PREPAREDNESS ACTIONS... Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && LAT...LON 4456 10911 4472 10912 4479 10867 4449 10870 TIME...MOT...LOC 1937Z 273DEG 14KT 4464 10896 Baker
Special weather statement, Jul 17, 2:17 PM MDT, 3 minutes before
Special Weather Statement National Weather Service Riverton WY 217 PM MDT TUE JUL 17 2018 WYZ012-013-172100- Jackson Hole-Teton and Gros Ventre Mountains- 217 PM MDT TUE JUL 17 2018 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL TETON COUNTY UNTIL 300 PM MDT... At 216 PM MDT, Doppler radar was tracking a strong thunderstorm over Mount Moran, or 13 miles northeast of Alta, moving east at 30 mph. Half inch hail and winds in excess of 40 mph will be possible with this storm. This strong thunderstorm will be near... Moran Bay and Leigh Lake around 225 PM MDT. Colter Bay Village around 235 PM MDT. Moran Junction around 245 PM MDT. Buffalo Valley Ranch around 255 PM MDT. Other locations impacted by this storm include Grand Targhee Resort, Lutons Log Cabins And Lodge, Signal Mountain Lodge, Leek's Marina, Jackson Lake Lodge, Lost Creek Ranch And Spa and Jenny Lake Lodge. PRECAUTIONARY/PREPAREDNESS ACTIONS... Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && LAT...LON 4374 11097 4390 11099 4404 11042 4368 11037 TIME...MOT...LOC 2016Z 265DEG 28KT 4384 11080 Baker
The office that day
Everything else NWS Riverton, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 16, 6:19 PM MDT | Special Weather Statement | RIW | Hot Springs | 26 min |
| Jul 16, 6:39 PM MDT | Special Weather Statement | RIW | Lincoln | 36 min |
| Jul 16, 6:43 PM MDT | Special Weather Statement | RIW | Teton | 47 min |
| Jul 16, 6:48 PM MDT | Special Weather Statement | RIW | Hot Springs | 27 min |
| Jul 16, 7:14 PM MDT | Special Weather Statement | RIW | Lincoln | 46 min |
| Jul 16, 7:15 PM MDT | Special Weather Statement | RIW | Hot Springs | 30 min |
| Jul 16, 7:26 PM MDT | Special Weather Statement | RIW | 49 min | |
| Jul 16, 8:12 PM MDT | Special Weather Statement | RIW | Fremont | 48 min |
| Jul 16, 8:52 PM MDT | Special Weather Statement | RIW | Fremont | 38 min |
| Jul 16, 9:11 PM MDT | Special Weather Statement | RIW | Fremont | 49 min |
| Jul 16, 9:43 PM MDT | Special Weather Statement | RIW | Fremont | 32 min |
| Jul 16, 9:47 PM MDT | Special Weather Statement | RIW | Fremont | 43 min |
| Jul 17, 1:37 PM MDT | Special Weather Statement | RIW | 38 min | |
| Jul 17, 2:17 PM MDT | Special Weather Statement | RIW | Teton | 43 min |
| Jul 17, 2:32 PM MDT | Special Weather Statement | RIW | Park | 43 min |
| Jul 17, 2:34 PM MDT | Special Weather Statement | RIW | 41 min | |
| Jul 17, 2:54 PM MDT | Severe Thunderstorm Warning | RIW | Johnson | 36 min |
| Jul 17, 3:24 PM MDT | Special Weather Statement | RIW | Big Horn | 21 min |
| Jul 17, 3:25 PM MDT | Severe Thunderstorm Warning | RIW | Johnson | 35 min |
| Jul 17, 3:28 PM MDT | Special Weather Statement | RIW | Johnson | 47 min |
| Jul 17, 3:41 PM MDT | Severe Thunderstorm Warning | RIW | Johnson | 12 min |
| Jul 17, 4:02 PM MDT | Special Weather Statement | RIW | Hot Springs | 28 min |
| Jul 17, 4:08 PM MDT | Special Weather Statement | RIW | Teton | 37 min |
| Jul 17, 4:20 PM MDT | Special Weather Statement | RIW | Johnson | 40 min |
| Jul 17, 4:23 PM MDT | Severe Thunderstorm Warning | RIW | Big Horn, Hot Springs, Washakie | 37 min |
| Jul 17, 4:29 PM MDT | Special Weather Statement | RIW | Johnson | 31 min |
| Jul 17, 4:32 PM MDT | Severe Thunderstorm Warning | RIW | Johnson | 28 min |
| Jul 17, 4:44 PM MDT | Special Weather Statement | RIW | Hot Springs | 31 min |
| Jul 17, 5:35 PM MDT | Special Weather Statement | RIW | Washakie | 25 min |
| Jul 17, 5:52 PM MDT | Special Weather Statement | RIW | Fremont | 23 min |
Nearby
Severe Thunderstorm Warnings in Wyoming, 2018Every severe thunderstorm warning in 2018
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.