Alert archive / Wyoming / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 41, NWS Riverton, WY

June 26, 2023Washakie County, Wyoming

NWS Riverton, WY issued this severe thunderstorm warning at Jun 26, 2023, 5:38 PM MDT for Washakie County, Wyoming. It was in force for 38 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 26, 2023, 5:38 PM MDT (23:38 UTC)
Expired: Jun 26, 2023, 6:16 PM MDT
In force: 38 min
Issued by: NWS Riverton, WY
Area: Storm-based polygon
Tornado: Possible
Hail: 1.25 in
Wind: 60.0 mph

County Washakie County, WY

The radar

The Riverton/Lander radar (KRIW), 113 km from the middle of the area, began a volume at 23:37 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

Great_falls, MT (KTFX), launched 12:00Z, 11.6 hours before the alert went out and 456 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1560 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 47 m²/s²
0-3 km storm-relative helicity: 45 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 26, 5:30 PM MDT, 8 minutes earlier.

Area forecast discussion, Jun 26, 5:30 PM MDT, 8 minutes before

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Hazardous weather outlook, Jun 26, 1:03 AM MDT, 16 hours 35 minutes before

Hazardous Weather Outlook
National Weather Service Riverton WY
103 AM MDT Mon Jun 26 2023

WYZ001>020-022>030-271115-
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-
103 AM MDT Mon Jun 26 2023

This Hazardous Weather Outlook is for Western and Central Wyoming.

.DAY ONE...Tonight.

Strong to marginally severe thunderstorms are expected to develop
early afternoon Monday off the Bighorns in Johnson County before
quickly pushing to the east of the CWA by late afternoon. The main
severe weather threats will be larger hail over the size of quarters
and damaging winds up to 60 mph. Tornado threat is low but locally
heavy rainfall is possible as well in areas of entraining storms or
rain showers that linger through the evening across much of the
northern half of the CWA. Any lingering rain showers and
thunderstorms will weaken towards sunset Monday evening.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Tuesday will see similar conditions as Monday but less of a severe
weather chance with weaker parameters expected. The severe weather
threat will be limited to Johnson County again during peak heating of
the afternoon being shortlived in the process. Lingering scattered
rain showers and isolated thunderstorms for the northern half of the
CWA east of the Divide expected once again into the evening hours
diminishing towards sunset once again.

Unsettled weather continues through the remainder of the long term
with scattered rain showers and isolated thunderstorms but severe
weather probability is low after Tuesday at this point in time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed.

In the hours before

Special weather statement, Jun 26, 4:11 PM MDT, 1 hour 27 minutes before

Special Weather Statement
National Weather Service Riverton WY
411 PM MDT Mon Jun 26 2023

WYZ010-011-262245-
Southeast Johnson County-Northeast Johnson County-
411 PM MDT Mon Jun 26 2023

...A strong thunderstorm will impact portions of east central Johnson
County through 445 PM MDT...

At 410 PM MDT, Doppler radar was tracking a strong thunderstorm 12
miles west of Powder River Rest Area, which is also 18 miles
southeast of Buffalo, moving east at 20 mph.

HAZARD...Winds in excess of 30 mph, penny size hail, and heavy rain.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This storm will remain over mainly rural areas of east central
Johnson County.

This includes Interstate 90 between mile markers 75 and 87.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4414 10644 4423 10646 4428 10619 4412 10619
TIME...MOT...LOC 2210Z 267DEG 18KT 4420 10641

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...30 MPH

Wittmann

Special weather statement, Jun 26, 4:33 PM MDT, 1 hour 5 minutes before

Special Weather Statement
National Weather Service Riverton WY
433 PM MDT Mon Jun 26 2023

WYZ010-011-262300-
Southeast Johnson County-Northeast Johnson County-
433 PM MDT Mon Jun 26 2023

...A strong thunderstorm will impact portions of central Johnson
County through 500 PM MDT...

At 433 PM MDT, Doppler radar was tracking a strong thunderstorm 10
miles south of Buffalo, moving east at 20 mph.

HAZARD...Half inch hail and heavy rain.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible.

This storm will remain over mainly rural areas of central Johnson
County.

This includes the following highways...
 Interstate 25 between mile markers 284 and 291.
 Interstate 90 between mile markers 66 and 70.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4413 10671 4422 10675 4431 10651 4416 10642
TIME...MOT...LOC 2233Z 251DEG 17KT 4420 10666

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...<30 MPH

Wittmann

Special weather statement, Jun 26, 4:44 PM MDT, 54 minutes before

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Special weather statement, Jun 26, 5:25 PM MDT, 13 minutes before

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Special weather statement, Jun 26, 5:28 PM MDT, 10 minutes before

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Special weather statement, Jun 26, 5:38 PM MDT, 0 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 25, 11:57 PM MDT	Special Weather Statement	RIW	Natrona	33 min
Jun 26, 12:38 AM MDT	Special Weather Statement	RIW	Natrona	52 min
Jun 26, 1:31 AM MDT	Special Weather Statement	RIW	Natrona	44 min
Jun 26, 2:11 AM MDT	Special Weather Statement	RIW	Natrona	34 min
Jun 26, 1:05 PM MDT	Special Weather Statement	RIW		25 min
Jun 26, 2:39 PM MDT	Special Weather Statement	RIW	Johnson	21 min
Jun 26, 2:59 PM MDT	Special Weather Statement	RIW	Johnson	16 min
Jun 26, 3:14 PM MDT	Special Weather Statement	RIW	Johnson	31 min
Jun 26, 3:18 PM MDT	Flash Flood Warning	RIW	Johnson	4 hr
Jun 26, 3:37 PM MDT	Severe Thunderstorm Warning	RIW	Johnson	38 min
Jun 26, 4:11 PM MDT	Special Weather Statement	RIW	Johnson	34 min
Jun 26, 4:13 PM MDT	Severe Thunderstorm Warning	RIW	Hot Springs, Park	32 min
Jun 26, 4:33 PM MDT	Special Weather Statement	RIW	Johnson	27 min
Jun 26, 4:36 PM MDT	Severe Thunderstorm Warning	RIW	Hot Springs	24 min
Jun 26, 4:44 PM MDT	Special Weather Statement	RIW	Johnson	16 min
Jun 26, 4:50 PM MDT	Severe Thunderstorm Warning	RIW	Johnson	15 min
Jun 26, 4:59 PM MDT	Severe Thunderstorm Warning	RIW	Hot Springs, Washakie	46 min
Jun 26, 5:05 PM MDT	Severe Thunderstorm Warning	RIW	Fremont, Hot Springs	25 min
Jun 26, 5:25 PM MDT	Special Weather Statement	RIW	Hot Springs	35 min
Jun 26, 5:28 PM MDT	Special Weather Statement	RIW		32 min
Jun 26, 5:38 PM MDT	Special Weather Statement	RIW	Hot Springs	22 min
Jun 26, 5:48 PM MDT	Severe Thunderstorm Warning	RIW	Hot Springs	27 min
Jun 26, 5:50 PM MDT	Severe Thunderstorm Warning	RIW	Fremont, Natrona	25 min
Jun 26, 5:55 PM MDT	Special Weather Statement	RIW	Hot Springs	35 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2023 Every severe thunderstorm warning in 2023

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.