Alert archive / Wyoming / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 28, NWS Cheyenne, WY

May 18, 2023Laramie County, Wyoming; Kimball County, Nebraska

NWS Cheyenne, WY issued this severe thunderstorm warning at May 18, 2023, 2:08 PM MDT for Laramie County, Wyoming; Kimball County, Nebraska. 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: May 18, 2023, 2:08 PM MDT (20:08 UTC)
Expired: May 18, 2023, 3:00 PM MDT
In force: 52 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

Counties Kimball County, NE, Laramie County, WY

The radar

The Cheyenne radar (KCYS), 52 km from the middle of the area, began a volume at 20:08 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

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 8.1 hours before the alert went out and 302 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: 873 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: -24 m²/s²
0-3 km storm-relative helicity: 64 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 May 18, 12:06 PM MDT, 2 hours 2 minutes earlier.

Area forecast discussion, May 18, 12:06 PM MDT, 2 hours 2 minutes before

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Hazardous weather outlook, May 18, 5:04 AM MDT, 9 hours 4 minutes before

Hazardous Weather Outlook
National Weather Service Cheyenne WY
504 AM MDT Thu May 18 2023

WYZ103>107-109>118-191115-
North Laramie Range-Ferris/Seminoe/Shirley Mountains-
Shirley Basin-Central Laramie Range and Southwest Platte County-
East Platte 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-
504 AM MDT Thu May 18 2023

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

.DAY ONE...TODAY AND TONIGHT

Another round of showers and thunderstorms are expected to form
late this morning over the mountains and track southeast over the
area into this evening. These thunderstorms may track over the
same area through the afternoon and produce heavy rainfall along
with small hail.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A drier airmass will limit thunderstorm coverage into the weekend.
Thunderstorms will return to southeast Wyoming by early next week.

.Spotter information statement...

Spotter activation will not be needed.

NEZ002-003-019>021-054-055-095-096-WYZ101-102-108-119-191115-
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-Goshen County-
East Laramie County-
504 AM MDT Thu May 18 2023

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

.DAY ONE...TODAY AND TONIGHT

Another round of thunderstorms are possible today with drier
conditions expected for this weekend. The best chance for
thunderstorms will be across the southern Nebraska Panhandle.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

The probability for widespread hazardous weather is low.

.Spotter information statement...

Spotter activation will not be needed.

In the hours before

Special weather statement, May 18, 11:16 AM MDT, 2 hours 52 minutes before

Special Weather Statement
National Weather Service Cheyenne WY
1116 AM MDT Thu May 18 2023

WYZ106-115-116-181800-
South Laramie Range WY-
Central Laramie Range and Southwest Platte County WY-
Laramie Valley WY-
1116 AM MDT Thu May 18 2023

...A strong thunderstorm will impact portions of east central Albany
County through NOON MDT...

At 1115 AM MDT, Doppler radar was tracking a strong thunderstorm 10
miles north of Bosler, or 29 miles north of Laramie, moving southeast
at 20 mph.

HAZARD...Winds in excess of 40 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 storm will remain over mainly rural areas of east central Albany
County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4171 10577 4180 10567 4172 10532 4151 10553
TIME...MOT...LOC 1715Z 305DEG 18KT 4173 10567

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

Natoli

Special weather statement, May 18, 11:55 AM MDT, 2 hours 13 minutes before

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Special weather statement, May 18, 12:30 PM MDT, 1 hour 38 minutes before

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Special weather statement, May 18, 12:50 PM MDT, 1 hour 18 minutes before

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Special weather statement, May 18, 1:23 PM MDT, 45 minutes before

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Special weather statement, May 18, 2:00 PM MDT, 8 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
May 17, 6:17 PM MDT	Special Weather Statement	CYS		43 min
May 17, 7:07 PM MDT	Special Weather Statement	CYS	Laramie	53 min
May 17, 8:38 PM MDT	Special Weather Statement	CYS	Albany	67 min
May 18, 11:16 AM MDT	Special Weather Statement	CYS	Albany	44 min
May 18, 11:36 AM MDT	Severe Thunderstorm Warning	CYS	Albany, Laramie	39 min
May 18, 11:40 AM MDT	Tornado Warning Tornado observed	CYS	Albany, Laramie	35 min
May 18, 11:55 AM MDT	Special Weather Statement	CYS	Albany	50 min
May 18, 12:30 PM MDT	Special Weather Statement	CYS	Laramie	45 min
May 18, 12:50 PM MDT	Special Weather Statement	CYS	Laramie	25 min
May 18, 1:23 PM MDT	Special Weather Statement	CYS	Laramie	37 min
May 17, 6:30 PM MDT	Special Weather Statement	CYS	Banner	45 min
May 17, 7:14 PM MDT	Special Weather Statement	CYS	Kimball	46 min
May 17, 7:30 PM MDT	Special Weather Statement	CYS	Sioux	45 min
May 17, 7:48 PM MDT	Special Weather Statement	CYS	Kimball	57 min
May 18, 2:00 PM MDT	Special Weather Statement	CYS	Kimball	45 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2023 Severe Thunderstorm Warnings in Nebraska, 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.