Alert archive / Wyoming / Special Weather Statements in 2021
Special Weather Statement, NWS Riverton, WY
NWS Riverton, WY issued this special weather statement at May 19, 2021, 5:50 PM MDT for Fremont County, Wyoming. It was in force for 25 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- May 19, 2021, 5:50 PM MDT (23:50 UTC)
- Expired
- May 19, 2021, 6:15 PM MDT
- In force
- 25 min
- Issued by
- NWS Riverton, WY
County Fremont County, WY
The radar
The Riverton/Lander radar (KRIW), 30 km from the middle of the area, began a volume at 23:53 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
Salt Lake City I, UT (KSLC), launched 12:00Z, 11.8 hours before the alert went out and 411 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
- 2894 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 41 m²/s²
- 0-3 km storm-relative helicity
- 77 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
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</html>What forecasters said that day
The local office's own words before this special weather statement 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 special weather statement went out at May 19, 2:01 PM MDT, 3 hours 49 minutes earlier.
Area forecast discussion, May 19, 2:01 PM MDT, 3 hours 49 minutes before
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</html>Hazardous weather outlook, May 19, 3:12 AM MDT, 14 hours 38 minutes before
Hazardous Weather Outlook National Weather Service Riverton WY 312 AM MDT Wed May 19 2021 WYZ001>020-022>030-200915- 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- 312 AM MDT Wed May 19 2021 This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and Tonight. Afternoon and evening thunderstorms possible across much of the area, with the most numerous in the northwest. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. Thursday...A good chance of thunderstorms across the northern half of the area, some storms could be strong to severe. Strong winds and elevated fire weather possible across southern Wyoming in the afternoon. Friday through Sunday...Widespread afternoon and evening thunderstorms across the area. Some storms could be strong to possibly severe. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions, according to standard operating procedures.
In the hours before
Special weather statement, May 19, 4:43 PM MDT, 1 hour 7 minutes before
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</html>Special weather statement, May 19, 5:27 PM MDT, 23 minutes before
Special Weather Statement National Weather Service Riverton WY 527 PM MDT Wed May 19 2021 WYZ017-200000- Wind River Basin- 527 PM MDT Wed May 19 2021 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL FREMONT COUNTY UNTIL 600 PM MDT... At 527 PM MDT, Doppler radar was tracking a strong thunderstorm over Arapahoe, or near Riverton, moving north at 35 mph. Half inch hail and wind gusts of 50 to 55 mph will be possible with this storm. This strong thunderstorm will be near... Ocean Lake around 545 PM MDT. Other locations impacted by this storm include Arapahoe Elementary School, St Stephens, Fremont County Fairgrounds and Riverton Regional Airport. PRECAUTIONARY/PREPAREDNESS ACTIONS... Brief heavy rainfall is also occurring with this storm. 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 4294 10833 4292 10857 4320 10866 4323 10829 TIME...MOT...LOC 2327Z 172DEG 32KT 4301 10847 Vorst
Special weather statement, May 19, 5:47 PM MDT, 3 minutes before
Special Weather Statement National Weather Service Riverton WY 547 PM MDT Wed May 19 2021 WYZ005-007-017-200015- Owl Creek and Bridger Mountains-Wind River Basin-Southwest Big Horn Basin- 547 PM MDT Wed May 19 2021 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL HOT SPRINGS AND EAST CENTRAL FREMONT COUNTIES UNTIL 615 PM MDT... At 546 PM MDT, Doppler radar was tracking strong thunderstorms along a line extending from 12 miles south of Hamilton Dome to 8 miles northeast of Ocean Lake. Movement was east at 30 mph. Pea size hail and wind gusts up to 50 mph will be possible with these storms. Strong thunderstorms will be near... Thermopolis and Hot Springs State Park around 615 PM MDT. Other locations impacted by these storms include Hot Springs County Fairgrounds and Hot Springs County Airport. PRECAUTIONARY/PREPAREDNESS ACTIONS... Brief heavy rainfall is also occurring with these storms. Frequent cloud to ground lightning is occurring with these storms. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. If on or near Ocean Lake and Boysen Reservoir, get out of the water and move indoors or inside a vehicle. Remember, lightning can strike out to 10 miles from the parent thunderstorm. If you can hear thunder, you are close enough to be struck by lightning. Move to safe shelter now! Do not be caught on the water in a thunderstorm. && LAT...LON 4376 10814 4328 10798 4325 10852 4366 10866 TIME...MOT...LOC 2346Z 265DEG 24KT 4360 10858 4328 10849 Vorst
Special weather statement, May 19, 5:50 PM MDT, 0 minutes before
Special Weather Statement
National Weather Service Riverton WY
550 PM MDT Wed May 19 2021
WYZ017-200015-
Wind River Basin-
550 PM MDT Wed May 19 2021
...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL FREMONT COUNTY UNTIL
615 PM MDT...
At 549 PM MDT, Doppler radar was tracking a strong thunderstorm near
Hidden Valley, or 7 miles northeast of Riverton, moving northeast at
30 mph.
Pea size hail and wind gusts up to 50 mph will be possible with this
storm.
This strong thunderstorm will be near...
Boysen State Park around 555 PM MDT.
Hidden Valley around 600 PM MDT.
Shoshoni around 615 PM MDT.
Other locations impacted by this storm include Bonneville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Brief heavy rainfall is also occurring with this storm.
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.
If on or near Boysen Reservoir, get out of the water and move indoors
or inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.
Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.
&&
LAT...LON 4299 10828 4312 10845 4340 10812 4340 10809
4342 10810 4316 10779
TIME...MOT...LOC 2349Z 226DEG 26KT 4311 10829
VorstThe office that day
Everything else NWS Riverton, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 19, 4:43 PM MDT | Special Weather Statement | RIW | Hot Springs | 32 min |
| May 19, 5:14 PM MDT | Special Weather Statement | RIW | Hot Springs | 31 min |
| May 19, 5:27 PM MDT | Special Weather Statement | RIW | Fremont | 33 min |
| May 19, 5:47 PM MDT | Special Weather Statement | RIW | Hot Springs | 28 min |
Nearby
Special Weather Statements in Wyoming, 2021Every special weather statement in 2021
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.