Winter Storm Warning 5, NWS Cheyenne, WY

Area Forecast Discussion
National Weather Service Cheyenne WY
1052 PM MDT Wed Apr 1 2026

.KEY MESSAGES...

- Cool and unsettled weather will remain in place through tonight
  with several chances for rain showers.

- Accumulating snow is expected for the higher mountains above
  9000 ft in elevation tonight through Wednesday evening.

- After a brief warmup Thursday, another strong cold front will
  sweep through the area and bring additional chances for rain,
  snow, and high winds Thursday afternoon into Friday.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 223 PM MDT Wed Apr 1 2026

An active weather work week is finally upon us! Multiple shortwaves
will be pushing through the forecast area. Continuing this evening,
a negatively tilted shortwave will continue to push in from the
West. Model soundings show our dry layer near the surface to slowly
erode away allowing for greater precipitation chances to occur
overnight. Southwesterly flow at 700mb is expected to continue
through the late mornings hours before more westerly flow develops
as a 700mb low attempts to develop with the approaching system. A
closed system at 700mb is progged to develop by 00Z Thursday in most
models, further showcasing the increasing strength of this system. A
stout Colorado Low will develop off the Rocky Mountains in eastern
Colorado this afternoon and evening, leading to northwesterly flow
across areas east of the Laramie Range and colder air funneling down
into the region. Mountain precipitation has already begun across the
Sierra Madre and Snowy Ranges, but precipitation chances spread
northeastward through the late morning and early afternoon hours.
Precipitation is anticipated to start as rain across much of the
area as 700mb temperatures remain too warm for snow. Some hi-res
model soundings suggest some CAPE pockets for the showers to take
advantage of. So with this small amount of CAPE available it can't
be ruled out for some weak thunderstorms or claps of thunder as
these showers pass overhead. NAEFS Mean Precipitable Water is above
the 99th percentile this afternoon, so good moisture is anticipated
with this system. A brief lull in precipitation is expected early
Thursday morning through the afternoon hours before precipitation
chances start increasing west to east. Upper-level flow will remain
largely zonal throughout the morning hours Thursday before the next
upper-level trough starts to move into the Intermountain West and
upper-level flow turns southwesterly once more. The closed, 500mb
system starts to move into western Wyoming by Thursday evening, with
much of the western portions of the CWA under strong, southwesterly
flow and within the left exit region of the trough, favoring
synoptic lift across the region. Another 700mb system is progged to
develop late Thursday night into the early morning hours Friday,
leading to increasing height gradients and strong, southwesterly
flow across western portions of the CWA and strong, westerly flow
across the Laramie Range. There is a little uncertainty with the
precipitation chances during this time as it will be a battle
between downsloping winds and the enhanced forcing this 700mb system
brings. The 700mb jet also ramps up Thursday night into Friday that
could possibly have a couple of brief blips of high winds along the
I-80 and I-25 corridor of Southeast Wyoming. Because the 700mb jet
continues to haphazardly ramp up to possible high wind criteria then
die down much like a rough running engine, the high wind watches
were left as is. Our in house algorithm also supports the general
train of thought for the low confidence high wind forecast as it
bounces between 40 to 60 percent probabilities between elevated and
high winds.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Issued at 223 PM MDT Wed Apr 1 2026

The weekend into early next week will feature a return to drier
weather as northwest flow transitions to weak ridging across the
western CONUS. Temperatures will run near to slightly above normal
throughout the period, however we will not see a return to record
high temperatures, at least for the next week or so. Northwest flow
behind our departing system on Saturday will result in a seasonably
chilly, but sunny day across southeast Wyoming and western Nebraska.
As ridging builds in from the southwest and mid-level temperatures
warm, expect a moderating trend to temperatures for Sunday with high
confidence in dry weather expected once again.

A bit more uncertainty enters the forecast from Monday through
Wednesday as a plume of subtropical moisture moves in through the
southwestern CONUS. This feature, underneath the building ridge,
gives almost a summery-flavor to the weather pattern with increasing
chances of afternoon convective showers and possibly thunder over
the higher terrain. At the very least, an increase in mid-level
moisture will make for cloudier afternoons from Monday through
midweek. Despite the cloud cover, warming mid-level temperatures will
compensate resulting in highs still running above average through
the period. Late in the long-term period on Wednesday into Thursday,
attention shifts to the chance of a more robust storm system to move
through the Central Rockies. A large amount of spread exists in
ensemble guidance for this period, with some members taking a
stronger low-pressure system through the region with rain and
mountain snow, and others limiting this event to a brief period of
moisture and a cold front. Still, the next major opportunity for
some form of accumulating precipitation of note looks to arrive on
Wednesday evening through Thursday of next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1052 PM MDT Wed Apr 1 2026

A progressive upper level trough will push east of the region
tonight, with rainfall and high elevation snow briefly ending after
midnight.  Can't rule out some terminals in/out of fog for the rest
of the night through 15z Thursday depending on cloud cover. Strong
gusty winds expected for KRWL and KLAR after 12z as a strong cold
front moves into the region.

HAZARDS/WEATHER TRENDS: Conditions will temporarily improve at the
southeast Wyoming terminals over the next few hours with VFR
conditions expected by 08z to 11z. Main concern for the rest of
tonight and into early Thursday will be the potential for fog and
LIFR CIGS. Tweaked the timing at most locations since the extent of
precipitation is not quite as widespread as previously thought.
Added VCFG for terminals which have a 10% to 25% chance of locally
dense fog. KAIA has the highest probability, so left the prevailing
LIFR conditions going between 09z and 15z. Fog and low CIGS will
lift by 17z for all terminals.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Watch from Thursday evening through Friday afternoon
     for WYZ106.
     High Wind Watch from Thursday morning through Thursday
     afternoon for WYZ109.
     High Wind Watch from Thursday morning through Friday afternoon
     for WYZ110.
     Winter Weather Advisory until 9 PM MDT this evening for WYZ112-
     114.
     High Wind Watch from Thursday morning through Friday evening
     for WYZ116-117.
     High Wind Watch from Thursday evening through Friday afternoon
     for WYZ118.
NE...None.

&&

SHORT TERM...MM
LONG TERM...MAC
AVIATION...TJT

Hazardous Weather Outlook
National Weather Service Cheyenne WY
228 PM MDT Wed Apr 1 2026

NEZ002-003-019>021-054-055-095-096-WYZ101>119-022030-
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-
228 PM MDT Wed Apr 1 2026

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

Cool and unsettled weather will remain in place through Wednesday
night with several chances for rain showers. Numerous showers and
isolated thunderstorms are expected this afternoon and evening. A
brief period of strong winds may occur along Interstate 80 behind
this activity.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

After a brief warmup Thursday, another strong cold front will sweep
through the area and bring additional chances for rain, snow, and
high winds Thursday afternoon into Friday.

.Spotter information statement...

Spotter activation will not be needed.