Alert archive / Wyoming / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 5, NWS Riverton, WY

June 6, 2019Park County, Teton County, Wyoming

NWS Riverton, WY issued this severe thunderstorm warning at Jun 6, 2019, 4:40 PM MDT for Park County, Teton County, Wyoming. It was in force for 20 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 6, 2019, 4:40 PM MDT (22:40 UTC)
Expired
Jun 6, 2019, 5:00 PM MDT
In force
20 min
Issued by
NWS Riverton, WY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Park County, WY, Teton County, WY

The radar

The Riverton/Lander radar (KRIW), 183 km from the middle of the area, began a volume at 22:42 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.

IssuedProductOfficeLasted
Jun 6, 1:54 PM MDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.7 hours before the alert went out and 362 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, Great_falls, MT at 12:00Z on 2019-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Great_falls, MT at 12:00Z on 2019-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 153 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1765 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
153 m²/s²
0-3 km storm-relative helicity
427 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

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 6, 3:36 PM MDT, 1 hour 4 minutes earlier.

Area forecast discussion, Jun 6, 3:36 PM MDT, 1 hour 4 minutes before
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Hazardous weather outlook, Jun 6, 3:49 AM MDT, 12 hours 51 minutes before
Hazardous Weather Outlook
National Weather Service Riverton WY
349 AM MDT Thu Jun 6 2019

WYZ001>020-022>030-071200-
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-
349 AM MDT Thu Jun 6 2019

This Hazardous Weather Outlook is for Western and Central Wyoming.

.DAY ONE...Today and Tonight

Scattered thunderstorms in the west. A few thunderstorms could be
strong to severe over the west late in the afternoon into the
evening hours.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Warm temperatures Thursday and Friday will continue the higher
elevation snowmelt resulting in rising water levels in creeks,
streams, and rivers into this weekend.

Friday...A chance of thunderstorms west and north. Mainly
isolated thunderstorms elsewhere. Some thunderstorms could be
strong in Johnson County. Windy many locations. Rain will turn to
snow in the mountains Friday night with 2 to 3 inches of snow
expected in Yellowstone Park and 1 to 2 inches expected above 9000
feet in the Teton Range and the Wind River Mountains.

Saturday...A chance of thunderstorms the central and north with
isolated activity in the south.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

TEAM RIVERTON

In the hours before

Special weather statement, Jun 6, 2:39 PM MDT, 2 hours 1 minute before
Special Weather Statement
National Weather Service Riverton WY
239 PM MDT Thu Jun 6 2019

WYZ004>006-062130-
North Big Horn Basin-Southeast Big Horn Basin-Southwest Big Horn
Basin-
239 PM MDT Thu Jun 6 2019

...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL HOT SPRINGS...SOUTH
CENTRAL BIG HORN AND NORTHWESTERN WASHAKIE COUNTIES UNTIL 330 PM
MDT...

At 238 PM MDT, Doppler radar was tracking a strong thunderstorm 13
miles northeast of Legend Rock State Petroglyph Site, which is 24
miles west of Worland, moving northeast at 35 mph.

Penny size hail and winds in excess of 40 mph will be possible with
this storm.

This storm will remain over mainly rural areas of north central Hot
Springs, south central Big Horn and northwestern Washakie Counties,
including the following locations... Badlands Overlook and Washakie
County Fairgrounds.

LAT...LON 4385 10851 4394 10863 4430 10813 4404 10775
TIME...MOT...LOC 2038Z 235DEG 29KT 4396 10844

Myers

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 6, 2:39 PM MDTSpecial Weather StatementRIWHot Springs51 min
Jun 6, 4:58 PM MDTSevere Thunderstorm WarningRIWPark, Teton17 min
Jun 6, 5:16 PM MDTSpecial Weather StatementRIW44 min
Jun 6, 5:57 PM MDTSpecial Weather StatementRIWTeton48 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2019Every severe thunderstorm warning in 2019

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.