Alert archive / Wyoming / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 71, NWS Cheyenne, WY

June 21, 2024Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 21, 2024, 8:09 PM MDT for Laramie County, Wyoming. It was in force for 51 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 21, 2024, 8:09 PM MDT (02:09 UTC)
Expired: Jun 21, 2024, 9:00 PM MDT
In force: 51 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 20 km from the middle of the area, began a volume at 02:09 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 21, 1:27 PM MDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 2.2 hours before the alert went out and 343 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: 607 J/kg
Mixed-layer CIN: -156 J/kg
Mixed-layer LCL: 1484 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 154 m²/s²
0-3 km storm-relative helicity: 171 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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 Cheyenne, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 21, 5:33 PM MDT, 2 hours 36 minutes earlier.

Area forecast discussion, Jun 21, 5:33 PM MDT, 2 hours 36 minutes before

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Hazardous weather outlook, Jun 21, 3:51 AM MDT, 16 hours 18 minutes before

Hazardous Weather Outlook
National Weather Service Cheyenne WY
351 AM MDT Fri Jun 21 2024

NEZ002-003-019>021-054-055-095-096-WYZ101>119-221000-
Dawes County-Box Butte County-Scotts Bluff County-Banner County-
Morrill County-Kimball County-Cheyenne County-
Northern Sioux County-Southern Sioux County-
Converse County Lower Elevations-Niobrara County-
North Laramie Range-Ferris/Seminoe/Shirley Mountains-
Shirley Basin-Central Laramie Range and Southwest Platte County-
East Platte County-Goshen County-Central Carbon County-
North Snowy Range Foothills-Southwest Carbon County-
Sierra Madre Range-Upper North Platte River Basin-Snowy Range-
Laramie Valley-South Laramie Range-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
351 AM MDT Fri Jun 21 2024

This hazardous weather outlook is for portions of panhandle
Nebraska...east central Wyoming...south central Wyoming and
southeast Wyoming.

.DAY ONE...TODAY AND TONIGHT

Widespread showers and thunderstorms expected once again this
afternoon into the early evening with a few severe thunderstorms
capable of producing large hail and strong winds. Localized
flooding is also possible with heavy rainfall.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

Warmer and drier trend starting on Saturday, but cannot rule out
gusty winds with high-based storms in the afternoon near the CO/WY
border.

Hot temperatures in the upper 80s to 90s are expected for Sunday
through much of next week. Elevations below 4500 feet will have
approximately a 30 to 60% chance of exceeding 100F on Monday.

.Spotter information statement...

Spotters are encouraged to report severe weather to the National
Weather Service in Cheyenne.

In the hours before

Special weather statement, Jun 21, 2:30 PM MDT, 5 hours 39 minutes before

Special Weather Statement
National Weather Service Cheyenne WY
230 PM MDT Fri Jun 21 2024

WYZ117-118-212100-
Central Laramie County WY-South Laramie Range Foothills WY-
230 PM MDT Fri Jun 21 2024

...STRONG THUNDERSTORMS WILL IMPACT SOUTHWESTERN LARAMIE COUNTY
THROUGH 300 PM MDT...

At 230 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from Whitaker to near Natural Fort. Movement was
east at 20 mph.

HAZARD...Wind gusts up to 40 mph and half inch hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Cheyenne, Rocking Star Ranch, Silver Sage Estates, Laramie County
Fairgrounds at Archer, Fox Farm-College, Cheyenne Regional Airport,
Winchester Hills, South Greeley Highway, Ranchettes, Warren AFB,
Frontier Park, North Cheyenne, South Cheyenne, Bison Crossing, Grass
Hills, and Cowboy Ranch South.

This includes the following highways...
 Interstate 25 in Wyoming between mile markers 1 and 28.
 Interstate 80 in Wyoming between mile markers 351 and 375.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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.

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
southeastern Wyoming.

&&

LAT...LON 4136 10502 4146 10461 4100 10452 4100 10501
TIME...MOT...LOC 2030Z 261DEG 16KT 4142 10487 4097 10487

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

Wills

Local storm report, Jun 21, 3:20 PM MDT, 4 hours 49 minutes before

Preliminary Local Storm Report
National Weather Service Cheyenne WY
320 PM MDT Fri Jun 21 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0244 PM     Hail             5 S Chugwater           41.68N 104.83W
06/21/2024  M1.00 Inch       Platte             WY   Fire Dept/Rescue

            Fire department responding to vehicle crash.

&&

SF

Local storm report, Jun 21, 3:22 PM MDT, 4 hours 47 minutes before

Preliminary Local Storm Report
National Weather Service Cheyenne WY
322 PM MDT Fri Jun 21 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0321 PM     Flash Flood      5 S Chugwater           41.69N 104.83W
06/21/2024                   Platte             WY   Fire Dept/Rescue

            Fire department responding to vehicle crash.
            Observing flash flooding.

&&

SF

Local storm report, Jun 21, 3:28 PM MDT, 4 hours 41 minutes before

Preliminary Local Storm Report
National Weather Service Cheyenne WY
328 PM MDT Fri Jun 21 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0319 PM     Flash Flood      7 S Chugwater           41.66N 104.85W
06/21/2024                   Platte             WY   Trained Spotter

            Video from social media showing water
            rapidly flowing over road and into nearby
            ditches.

&&

SF

Special weather statement, Jun 21, 3:40 PM MDT, 4 hours 29 minutes before

Special Weather Statement
National Weather Service Cheyenne WY
340 PM MDT Fri Jun 21 2024

WYZ102-108-212215-
Goshen County WY-Niobrara County WY-
340 PM MDT Fri Jun 21 2024

...STRONG THUNDERSTORMS WILL IMPACT SOUTHEASTERN NIOBRARA AND
NORTHERN GOSHEN COUNTIES THROUGH 415 PM MDT...

At 339 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 6 miles southeast of Lusk to near Pine Ridge
Estates. Movement was northeast at 40 mph.

HAZARD...Wind gusts up to 50 mph and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Van Tassell, Prairie Center, Jay Em, and Hwy 85 At Dry Rawhide Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
southeastern and east central Wyoming.

&&

LAT...LON 4288 10406 4230 10406 4230 10465 4272 10440
TIME...MOT...LOC 2139Z 238DEG 33KT 4270 10435 4233 10455

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH

Wills

Special weather statement, Jun 21, 5:58 PM MDT, 2 hours 11 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 21, 6:04 PM MDT	Special Weather Statement	CYS	Carbon	71 min
Jun 21, 6:17 PM MDT	Special Weather Statement	CYS	Platte	43 min
Jun 21, 7:58 PM MDT	Special Weather Statement	CYS	Laramie	47 min
Jun 21, 8:24 PM MDT	Special Weather Statement	CYS	Laramie	51 min
Jun 21, 9:18 PM MDT	Special Weather Statement	CYS	Goshen	27 min
Jun 22, 3:31 PM MDT	Special Weather Statement	CYS		59 min
Jun 21, 9:27 PM MDT	Special Weather Statement	CYS	Banner	33 min
Jun 21, 10:30 PM MDT	Special Weather Statement	CYS	Morrill	60 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2024 Every severe thunderstorm warning in 2024

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.