High Wind Warning 30, NWS Cheyenne, WY

988 
WWUS75 KCYS 152158
NPWCYS

URGENT - WEATHER MESSAGE
National Weather Service Cheyenne WY
Issued by National Weather Service Riverton WY
358 PM MDT Thu May 15 2025

WYZ116-117-152300-
/O.EXP.KCYS.HW.W.0030.000000T0000Z-250515T2200Z/
South Laramie Range-South Laramie Range Foothills-
Including the cities of Pumpkin Vine, Vedauwoo, Whitaker, Horse
Creek, Buford, and Federal
358 PM MDT Thu May 15 2025

...HIGH WIND WARNING WILL EXPIRE AT 4 PM MDT THIS AFTERNOON...

Wind gusts have fallen below high wind thresholds and this trend is 
expected to continue into the evening hours. Therefore, the High 
Wind Warning will expire at 4 PM MDT. Wind gusts of 40 to 50 mph 
will persist along Interstate 80 until sunset Thursday.

$$

CNJ

Area Forecast Discussion
National Weather Service Cheyenne WY
Issued by National Weather Service Riverton WY
1105 AM MDT Thu May 15 2025

.KEY MESSAGES...

- Very windy conditions expected for most of southeast Wyoming and
  portions of western Nebraska on Thursday. Gusts over 50 mph possible.

- Seasonable temperatures into this weekend with isolated thunderstorms
  returning on Saturday.

- Active weather pattern late this weekend and early next week
  as another Pacific storm system impacts the region.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 227 AM MDT Thu May 15 2025

Current KCYS radar loops shows remnant light rain across
western Nebraska and far eastern Wyoming as a strong surface low
across eastern Nebraska lifts northeast early this morning. The
upper level trough, which pushed across the region today, is
forecast to stall and become a closed low across the Dakotas
today. Models show this system remaining over the Dakotas into
tonight and possibly even retrograding westward a bit before it
begins lifting northeast into the Great Lakes region into early
Friday morning. Expect rain showers to continue early this
morning with a brief lull later this morning through sunrise. It
continues to look very windy across southeast Wyoming and
portions of western Nebraska due to the strengthening surface
low to our east. However, 700mb winds are not quite as strong in
contrast to 24 hours ago and winds aloft actually strengthen
above 50 knots tonight instead of this afternoon. Will continue
to keep an eye on the wind prone areas and adjacent High Plains
for potential High Wind Watches/Warnings, but strong wind gusts
appear to be brief with low confidence in timing. In addition,
showers and thunder showers are expected this afternoon behind
the main storm system as a secondary shortwave trough moves
eastward into Wyoming. Any convective winds associated with
shower and thunder shower activity will likely complicate the
timing and magnitude of the environmental winds. Expect
sustained winds out of the northwest 25 to 40 mph with gusts
around 50 mph. Thursday will likely be the coolest day of the
week with most of southeast Wyoming in the 50s to low 60s, with
low to mid 60s over western Nebraska.

Friday looks like the driest day of the next 7 days across the
region as a much drier airmass moves into Wyoming as the storm
system to our east begins to push into the Great Lakes region.
Midlevel subsidence associated with the building upper level
ridge should suppress most convective initiation into the
evening hours. Otherwise, expect a slight warming trend with
700mb temperatures increasing between 0C to 5C, which should
translate to highs in the 60s across southeast Wyoming and upper
60s to lower 70s for western Nebraska. It will remain windy,
but winds should start to ease in the mid to late afternoon
hours.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 227 AM MDT Thu May 15 2025

Previous forecast on track for most of this weekend with model
solutions diverging significantly compared to the last few days
regarding the next Pacific storm system for early next week.
Expect showers and thunderstorms to return to the region on
Saturday as the mid to upper level flow shifts to the southwest
with gradually warm air advection and a brief warming trend.
High temperatures on Saturday will return to the mid 60s to mid
70s...warmest over the eastern plains. Models show a weak
shortwave disturbance lifting northeast ahead of the next
Pacific storm system moving into the Great Basin region late on
Saturday. This disturbance will help initiate scattered rain
showers and widely scattered thunderstorms across southeast
Wyoming. These storms will then move northeast into western
Nebraska during the evening hours. Although severe storms are
not expected at this time, a few stronger storms are possible
with gusty winds and small hail the primary threats.

For Sunday, we will be tracking the potent Pacific disturbance
which is forecast to move across the eastern Great Basin region
on Sunday. Models are no longer showing a closed upper level low
across the Four Corners region with even the 00Z ECMWF backing
off on this solution. All models are now showing the secondary
disturbance, which is forecast to dig south out of the Pacific
NW, trending much later in terms of timing and not as organized.
Therefore, most models eject this system eastward much faster
and further south than previous forecasts suggested. Therefore,
ensemble guidance has continued to trend lower on QPF and PoP
for early next week due to the lack of a closed upper level low
to the south of the forecast area. However, will still have to
keep an eye on the first upper level trough and associated
potent disturbance that lifts northeast across Colorado and the
eastern plains Sunday afternoon. Along with scattered to
numerous thunderstorms possible with moderate to heavy rainfall,
models and ensembles are starting to indicate a severe weather
threat for the High Plains (along and east of Interstate 25)
with ample 0-6km shear values over 40 knots and MLCAPE of 1000
to 2000 J/kg. Forcing is also evident as the first upper level
trough lifts northeast over the area with some cyclogenesis over
northeastern Colorado and the southern Nebraska Panhandle,
which should also help low level easterly moisture advection
into the area as well as low level shear. Kept high PoP above
60% for most of the eastern plains with a favorable pattern for
strong to severe thunderstorms and appreciable rainfall amounts.

For early next week, models now show drier conditions Tuesday through
Thursday with lower coverage of showers and thunderstorms as the upper
level flow shifts to the west and the storm track/jet stream
shifts north towards the Canadian border. Expect another warming
trend with high temperatures back into the 60s and 70s by
midweek if current trends continue.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1057 AM MDT Thu May 15 2025

CU field continues to bubble up this afternoon as a wave moves
across eastern WY/western NE. Some light showers are developing,
but support is a lot less than that of yesterday. Best chances
for showers remain toward KRWL/KLAR through this afternoon, but
some showers may still reach the remainder of the sites through
00Z. Have added a couple TEMPO groupings for western sites, with
PROB30 for KBFF/KCDR until peak heating ends early this
evening. Winds will continue to howl through the day, with
frequent gusts at 40kts through this evening. Winds will ramp
down overnight, but jump back up early tomorrow morning with
more gusts above 35kts. The main weather system in the Dakotas
tries to wrap back southward Friday morning, and may bring some
low clouds and light rain to KCDR, possibly as far south as
KAIA through 18Z.

&&

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

&&

SHORT TERM...TJT
LONG TERM...TJT
AVIATION...WFO-RIW

Hazardous Weather Outlook
National Weather Service Cheyenne WY
Issued by National Weather Service Riverton WY
425 AM MDT Thu May 15 2025

NEZ002-003-019>021-054-055-095-096-WYZ101>119-161030-
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-
425 AM MDT Thu May 15 2025

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

.DAY ONE...TODAY AND TONIGHT

Very windy conditions are forecast for most of southeast
Wyoming and the higher ridges of the western Nebraska
Panhandle. West to northwest winds between 25 to 40 mph are
expected with gusts as high as 55 mph at times. Stronger winds
are possible along portions of Interstate 25 and the Interstate
80 Summit. Isolated thunderstorms are possible this afternoon
and this evening.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

Remaining windy on Friday with drier conditions. Thunderstorms
will increase in coverage this weekend and early next week.
Some of the thunderstorms on Sunday may become strong to severe
across the eastern plains.

.Spotter information statement...

Spotter activation will not be needed.

Preliminary Local Storm Report
National Weather Service Cheyenne WY
732 AM MDT Thu May 15 2025

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

0730 AM     Rain             0.1 N Hillsdale         41.21N 104.48W
05/15/2025  M0.65 Inch       Laramie            WY   CO-OP Observer

            CO-OP observer called to report 0.65 inches
            of rain from last nights storm.

&&