Alert archive / Wyoming / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 187, NWS Cheyenne, WY

June 29, 2023Converse County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 29, 2023, 12:56 PM MDT for Converse County, Wyoming. It was in force for 52 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 29, 2023, 12:56 PM MDT (18:56 UTC)
Expired
Jun 29, 2023, 1:48 PM MDT
In force
52 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Damage threat
Considerable
Hail
1.75 in
Wind
60.0 mph

County Converse County, WY

The radar

The Cheyenne radar (KCYS), 210 km from the middle of the area, began a volume at 18:56 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, 6.9 hours before the alert went out and 235 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, Riverton, WY at 12:00Z on 2023-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 51 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2023-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 square meters per square second.193958Sfc1 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
51 J/kg
Mixed-layer CIN
-125 J/kg
Mixed-layer LCL
1483 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
89 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 Cheyenne, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 29, 11:33 AM MDT, 1 hour 23 minutes earlier.

Area forecast discussion, Jun 29, 11:33 AM MDT, 1 hour 23 minutes before
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Hazardous weather outlook, Jun 29, 4:49 AM MDT, 8 hours 7 minutes before
Hazardous Weather Outlook
National Weather Service Cheyenne WY
449 AM MDT Thu Jun 29 2023

NEZ002-003-019>021-054-055-095-096-WYZ101>103-106>108-115>119-
301100-
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-
Central Laramie Range and Southwest Platte County-
East Platte County-Goshen County-Laramie Valley-
South Laramie Range-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
449 AM MDT Thu Jun 29 2023

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

.DAY ONE...TODAY AND TONIGHT

Scattered to numerous showers and thunderstorms are expected
across southeast Wyoming and the western Nebraska Panhandle this
afternoon through late tonight. A few storms are likely to become
severe, with very large and destructive hail larger than golf
balls possible with the most intense storms. Localized flash
flooding, damaging wind gusts, and isolated tornadoes are also
possible.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

An unsettled weather pattern will contribute to daily chances for
showers and thunderstorms across the region. Occasional chances
for strong to severe thunderstorms are expected.

.Spotter information statement...

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

WYZ104-105-109>114-301100-
Ferris/Seminoe/Shirley Mountains-Shirley Basin-
Central Carbon County-North Snowy Range Foothills-
Southwest Carbon County-Sierra Madre Range-
Upper North Platte River Basin-Snowy Range-
449 AM MDT Thu Jun 29 2023

This hazardous weather outlook is for portions of south central
Wyoming.

.DAY ONE...TODAY AND TONIGHT

Scattered to numerous showers and thunderstorms are expected
across southeast Wyoming and the western Nebraska Panhandle this
afternoon through late tonight. A few stronger storms may produce
small hail, gusty winds, and locally heavy rainfall.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

The probability for widespread hazardous weather is low.

.Spotter information statement...

Spotter activation is not anticipated.

In the hours before

Special weather statement, Jun 29, 12:16 PM MDT, 40 minutes before
Special Weather Statement
National Weather Service Cheyenne WY
1216 PM MDT Thu Jun 29 2023

WYZ103-291900-
North Laramie Range WY-
1216 PM MDT Thu Jun 29 2023

...A strong thunderstorm will impact portions of southwestern
Converse County through 100 PM MDT...

At 1216 PM MDT, Doppler radar was tracking a strong thunderstorm near
Boxelder, or 24 miles southwest of Douglas, moving southwest at 15
mph.

HAZARD...Wind gusts of 50 to 55 mph and nickel size hail.

SOURCE...Radar indicated.

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

This strong thunderstorm will be near...
  Campbell Creek Campground around 1250 PM MDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4272 10577 4264 10558 4244 10573 4245 10603
TIME...MOT...LOC 1816Z 032DEG 11KT 4256 10580

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...55 MPH

Rubin

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 28, 6:20 PM MDTSevere Thunderstorm WarningCYSLaramie40 min
Jun 28, 6:46 PM MDTSevere Thunderstorm WarningCYSLaramie59 min
Jun 28, 7:17 PM MDTSpecial Weather StatementCYSLaramie43 min
Jun 28, 7:47 PM MDTSpecial Weather StatementCYSConverse58 min
Jun 28, 8:15 PM MDTSevere Thunderstorm WarningCYSConverse45 min
Jun 28, 8:18 PM MDTSpecial Weather StatementCYSAlbany42 min
Jun 29, 12:16 PM MDTSpecial Weather StatementCYSConverse44 min
Jun 29, 1:35 PM MDTSevere Thunderstorm WarningCYSConverse, Platte40 min
Jun 29, 1:59 PM MDTSevere Thunderstorm WarningCYSConverse46 min
Jun 29, 2:02 PM MDTSpecial Weather StatementCYSPlatte43 min
Jun 29, 2:12 PM MDTSevere Thunderstorm WarningCYSAlbany, Laramie, Platte63 min
Jun 29, 2:13 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSConverse, Platte47 min
Jun 29, 2:27 PM MDTSpecial Weather StatementCYSAlbany48 min
Jun 29, 2:41 PM MDTSevere Thunderstorm WarningCYSConverse49 min
Jun 29, 2:55 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSConverse, Goshen, Niobrara, Platte50 min
Jun 29, 2:56 PM MDTFlash Flood WarningCYSConverse3 hr
Jun 29, 3:11 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSLaramie, Platte64 min
Jun 29, 3:16 PM MDTSpecial Weather StatementCYSAlbany44 min
Jun 29, 3:16 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte29 min
Jun 29, 3:21 PM MDTSevere Thunderstorm WarningCYSNiobrara24 min
Jun 29, 3:22 PM MDTTornado WarningCYSLaramie, Platte23 min
Jun 29, 3:44 PM MDTSevere Thunderstorm WarningCYSGoshen, Niobrara, Platte46 min
Jun 29, 3:54 PM MDTSpecial Weather StatementCYSCarbon51 min
Jun 29, 4:01 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSGoshen, Laramie, Platte74 min
Jun 29, 4:04 PM MDTFlash Flood WarningCYSNiobrara91 min
Jun 29, 4:28 PM MDTSpecial Weather StatementCYSGoshen32 min
Jun 29, 4:44 PM MDTSpecial Weather StatementCYSGoshen31 min
Jun 29, 5:04 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie71 min
Jun 29, 5:30 PM MDTAreal Flood AdvisoryCYSGoshen, Laramie3 hr
Jun 29, 5:52 PM MDTSpecial Weather StatementCYSLaramie38 min
Jun 29, 5:57 PM MDTSpecial Weather StatementCYSAlbany48 min
Jun 28, 6:09 PM MDTSevere Thunderstorm Warning Destructive damage threatCYSCheyenne, Kimball81 min
Jun 28, 6:14 PM MDTTornado Warning Tornado observedCYSKimball31 min
Jun 28, 6:18 PM MDTSpecial Weather StatementCYSDawes42 min
Jun 28, 6:43 PM MDTTornado Warning Tornado observedConsiderable damage threatCYSKimball32 min
Jun 28, 6:58 PM MDTSpecial Weather StatementCYSCheyenne47 min
Jun 28, 6:58 PM MDTTornado Warning Considerable damage threatCYSCheyenne, Kimball32 min
Jun 28, 7:10 PM MDTSevere Thunderstorm WarningCYSCheyenne65 min
Jun 28, 7:40 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSCheyenne, Kimball45 min
Jun 28, 7:43 PM MDTFlash Flood WarningCYSKimball63 min
Jun 28, 7:53 PM MDTSpecial Weather StatementCYSBanner52 min
Jun 28, 10:46 PM MDTSpecial Weather StatementCYSKimball29 min
Jun 29, 4:12 PM MDTSpecial Weather StatementCYSSioux33 min
Jun 29, 4:50 PM MDTSpecial Weather StatementCYSSioux25 min
Jun 29, 5:13 PM MDTSpecial Weather StatementCYSDawes32 min
Jun 29, 5:46 PM MDTSpecial Weather StatementCYSBox Butte, Dawes59 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2023Every 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.