Severe Thunderstorm Warning 29, NWS Cheyenne, WY

Area Forecast Discussion
National Weather Service Cheyenne WY
139 PM MDT Fri May 23 2025

.KEY MESSAGES...

- Slight Risk (Level 2 of 5) for severe weather Friday across
  portions of the Nebraska Panhandle. All threats are possible.

- Unsettled weather expected to continue this weekend through next
  week with daily chances for showers and thunderstorms.
  Temperatures will be near or slightly below average for late May.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 1130 AM MDT Fri May 23 2025

Low stratus is currently clearing out of the CWA after ample
moisture advection overnight. Observations from across the area show
dewpoints in the 50s across the Nebraska panhandle, 40s along the
Interstate 25 corridor, and 20s on the west side of the dryline that
is sitting over the Laramie Range. Models like the RAP show
dewpoints continuing to increase in the southern panhandle this
afternoon as southeasterly flow intensifies moisture advection from
the Gulf. A weak disturbance moving overhead will likely spark
convection along the dryline early this afternoon. Storms will push
eastward into Nebraska through the afternoon hours, moving into an
environment more favorable for severe storms.

Model soundings from across western Nebraska are rather aggressive
this afternoon. GFS soundings around Sidney show MUCAPE values in
excess of 2000 J/kg. Effective shear is greater than 40 kts with
steep mid-level lapse rates. These variables lend itself to a
significant hail threat, with hail larger than 2 inches in
diameter possible. Cannot rule out an isolated tornado as well
with effective shear values as high as they are with MLCAPE
values greater than 1500 J/kg. Most Hi-Res guidance also
suggests discrete cells this afternoon which also lends itself
to more of a large hail and isolated tornado threat. Cannot rule
out damaging wind gusts as well with DCAPE values greater than
900 J/kg with storm clusters possible. Most guidance shows a
relatively short window for convection this afternoon.
Initiation will likely be early this afternoon, with peak
intensity of storms expected late this afternoon. Severe storms
will push out of the CWA this evening, with a few lingering
storms possible overnight.

Weak moisture advection will continue overnight, leading to areas of
fog and low stratus Saturday morning, mainly east of the Laramie
Range. Moist southerly flow will continue throughout most of the day
in the mid-levels ahead of an approaching shortwave. This will
increase PWATs into the 90th percentile for NAEFS climatology.
Combined with the vorticity maxes aloft, widespread precipitation
will likely develop during the afternoon. Hi-Res guidance shows most
of the CWA seeing precipitation at some point during the
day/evening. The severe threat will be limited somewhat by a
cooler environment. Model soundings do still show modest
instability, especially around the Cheyenne area, which suggests
this may be where some of the stronger storms are. The clustery
nature of the storms tomorrow will lend itself more to a strong
wind threat, however hail cannot be ruled out. Showers and
storms could linger into the overnight hours, however coverage
of storms will be much lower.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 135 PM MDT Fri May 23 2025

Sunday...Expecting a cool day due to widespread cloud cover and
precipitation coverage, with high temperatures in the 50s east of I-
25, with 60s further west. With a deep, moist airmass in place, low
level upslope east winds and a passing shortwave trough aloft, we
anticipate widespread showers and scattered thunderstorms in the
afternoon and evening.

Monday...Somewhat similar pattern to Sunday, although the flow aloft
turns northwesterly with slightly less moisture available. Still
though, we expect scattered to numerous showers and scattered
thunderstorms in the afternoon and evening.

Tuesday...Northwest flow aloft continues and with adequate low and
mid level moisture, we expect to see scattered late day showers and
thunderstorms, though with less areal coverage compared to Monday.
Warmer temperatures compared to Monday based on 700 mb temperatures.

Wednesday...Another comparable scenario to Tuesday, with north
northwest flow aloft and low level upslope winds, providing enough
shear and instability for scattered afternoon and evening showers
and thunderstorms. Slightly cooler than Tuesday based on 700 mb
temperature trends.

Thursday-Friday...The flow aloft turns northerly, with some drying
noted in the low and mid levels, thus we should see a decrease in
areal coverage of afternoon and evening showers and thunderstorms,
though moisture looks plentiful enough for scattered coverage. With
700 mb temperatures from 7-9 Celsius, maximum temperatures will show
a warming trend.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1135 AM MDT Fri May 23 2025

There is a weak dry line looking boundary that is east of the
Laramie Range forming. Between 20z to 02z thunderstorms are
expected to develop KCYS and east minus KCDR. SPC has the main
threat being hail and wind. The storms look to stay just south
of KCDR so there may be some VCTS or VCSH depending on timing
and location of these storms. Overnight, a nocturnal inversion
may develop creating some fog or low stratus over the panhandle
and KCYS. This may burn off by 15z but low confidence in timing
for that burn off.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.

&&

SHORT TERM...SF
LONG TERM...RUBIN
AVIATION...MM

Hazardous Weather Outlook
National Weather Service Cheyenne WY
140 PM MDT Fri May 23 2025

NEZ002-003-019>021-054-055-095-096-WYZ101>119-241945-
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-
140 PM MDT Fri May 23 2025

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

- Slight Risk (Level 2 of 5) for severe weather Friday across
  portions of the Nebraska Panhandle. All threats are possible.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

- Unsettled weather expected to continue this weekend through next
  week with daily chances for showers and thunderstorms.
  Temperatures will be near or slightly below average for late May.

.Spotter information statement...

Spotters are encouraged to report severe weather to the NWS.

Special Weather Statement
National Weather Service Cheyenne WY
306 PM MDT Fri May 23 2025

WYZ117>119-232130-
Central Laramie County WY-South Laramie Range Foothills WY-
East Laramie County WY-
306 PM MDT Fri May 23 2025

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL LARAMIE COUNTY THROUGH
330 PM MDT...

At 305 PM MDT, Doppler radar was tracking a strong thunderstorm near
Whitaker, or 15 miles north of Cheyenne, moving east at 20 mph.

HAZARD...Wind gusts of 50 to 55 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...
Whitaker.

This includes Interstate 25 in Wyoming between mile markers 27 and
29.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

&&

LAT...LON 4126 10479 4140 10490 4153 10450 4135 10441
TIME...MOT...LOC 2105Z 248DEG 18KT 4137 10479

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...55 MPH

MM

Special Weather Statement
National Weather Service Cheyenne WY
318 PM MDT Fri May 23 2025

NEZ019-020-WYZ108-119-232200-
Scotts Bluff NE-Banner NE-Goshen County WY-East Laramie County WY-
318 PM MDT Fri May 23 2025

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN SCOTTS BLUFF...
NORTHWESTERN BANNER...SOUTHEASTERN GOSHEN AND NORTHEASTERN LARAMIE
COUNTIES THROUGH 400 PM MDT...

At 318 PM MDT, Doppler radar was tracking a strong thunderstorm over
Meriden Rest Area, or 36 miles south of Torrington, moving east at 20
mph.

HAZARD...Wind gusts of 50 to 55 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...
La Grange and Meriden Rest Area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
the Panhandle of Nebraska...and southeastern Wyoming.

&&

LAT...LON 4143 10433 4160 10440 4170 10398 4147 10391
TIME...MOT...LOC 2118Z 253DEG 17KT 4154 10428

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...55 MPH

MM

Special Weather Statement
National Weather Service Cheyenne WY
332 PM MDT Fri May 23 2025

NEZ054-232200-
Kimball NE-
332 PM MDT Fri May 23 2025

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN KIMBALL COUNTY
THROUGH 400 PM MDT...

At 332 PM MDT, Doppler radar was tracking a strong thunderstorm 8
miles south of Oliver Reservoir, or 12 miles southwest of Kimball,
moving east at 20 mph.

HAZARD...Wind gusts of 50 to 55 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.

This storm will remain over mainly rural areas of southwestern
Kimball County.

This includes Interstate 80 in Nebraska between mile markers 13 and
18.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
the Panhandle of Nebraska.

&&

LAT...LON 4101 10391 4114 10397 4122 10372 4109 10359
TIME...MOT...LOC 2132Z 253DEG 17KT 4110 10383

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...55 MPH

MM

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Preliminary Local Storm Report
National Weather Service Cheyenne WY
518 PM MDT Fri May 23 2025

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

0448 PM     Hail             11 NE Scottsbluff       41.98N 103.51W
05/23/2025  M1.25 Inch       Scotts Bluff       NE   Public

            Facebook image of 1.25in hail northeast of
            Lake Minatare.

&&