Cheyenne, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

286
FXUS65 KCYS 021746
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1146 AM MDT Wed Apr 2 2025

.KEY MESSAGES...

- Snow showers may rotate back into the US-20 corridor through
  Wednesday morning, with up to two additional inches of slushy
  accumulation possible. Scattered, squall-like showers possible
  across much of the forecast area this afternoon.

- Widespread gusty winds are expected Wednesday. There is
  approximately a 40% chance for high winds in the wind prone
  areas along I-80.

- Below average temperatures alongside a chance of light mixed
  precipitation moving into the weekend, with dry conditions and
  a warming trend to start next week.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 350 AM MDT Wed Apr 2 2025

With the surface low from yesterday`s system now well off to the
east in Nebraska, shower activity early this morning has been
relatively quiet. Radar shows some light echoes across the panhandle
and out west by Rawlins, but ground truth confirms light snow mainly
between Cheyenne and Rawlins along Interstate 80. Lingering
wrap around moisture from the low pressure system will lead to
additional snow showers along the Pine Ridge. Northwest upslope
flow could lead to an inch or two of additional snowfall in the
Pine Ridge. As instability increases throughout the day, Hi-Res
guidance shows scattered showers developing across much of the
CWA. Wrap around moisture will help fuel some of these showers.
Given steep lapse rates and some background windiness from a
tight pressure gradient across the area, some squall-like
showers could be possible and could even produce a rumble of
thunder. These squall-like showers could cause rapidly changing
conditions so use caution if traveling. Showers will taper off
this evening as instability weakens.

As mentioned, a windy day is expected across much of the area. A
strong MSLP gradient across the Laramie Range will make some of the
wind prones more susceptible to high winds this morning. The
South Laramie Range has about a 40 percent chance of seeing high
winds this morning per in-house guidance. Winds aloft this
morning will max out around 45 kts with good subsidence. Winds
aloft will begin to weaken later in the morning. For now, held
off on any wind products as observations have not shown an
uptick in winds yet as the GFS has suggested. This event also
looks marginal, with 50+ MPH wind gusts possible for only a
brief time this morning.

On Thursday, yet another upper-level trough will begin to make its
way into the Rockies. A surface low developing in southern Colorado
will move into Kansas, pushing precipitation up into the Interstate
80 corridor by Thursday afternoon. The GFS and ECMWF differ in what
happens Thursday night. The GFS is quick to dissipate precipitation
while the ECMWF creates a bit more complex system that pushes
precipitation further north into the CWA that continues into the day
Friday.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Issued at 350 AM MDT Wed Apr 2 2025

No significant changes to the medium to long range forecast with
models remaining in good agreement until late Monday. Models continue
to show a long wave trough remaining over the Intermountain West
and adjacent high plains late this week and into the weekend.
Expect a continuation of cloudy skies, intermittent snow with
rain below 4500 feet, and temperatures much below average for
this time of the year. Although it will be pretty cold for early
April with high temperatures generally ranging between the mid
30s to mid 40s, this pattern will result in generally light winds
through the weekend. Low clouds and some fog are possible Friday
through the weekend, but confidence is limited at this time due
to persistent mid to high clouds. Saturday morning and Sunday
morning will likely be the coldest with lows in the teens to low
20s across much of southeast Wyoming and western Nebraska.

Primary forecast concern will be for late Friday and into the
weekend as a potent disturbance drifts east across the southwest
United States and attempts to redevelop across the central or
southern plains. All models continue to show this energy too far
south to pose much of a threat to southeast Wyoming and western
Nebraska. Ensembles are less excited about it as well and have
continued to trend lower on precipitation totals. Do expect a
period of light snow, with rain/snow mixing below 4500 feet,
late on Friday and Friday night. There is enough frontogenesis
and low level lift to justify 60+ POP along Interstate 80 and a
few inches of snow, mainly on grassy surfaces, as another cold
front and reinforcing shot of cold air moves south across the
high plains Friday night.

As we head into Sunday and early next week, models are trending
faster with ejecting this energy eastward into the Great Plains,
with most models now showing clearing skies and drier conditions
by Saturday afternoon. Continued to lower POP on Saturday and
Saturday night. Otherwise, expect a gradual warming trend Sunday
through early next week. Models are trending slightly cooler for
Monday and Tuesday as some Pacific energy starts to move into
the area...likely resulting from the earlier departure of
Friday/Friday night`s disturbance and long wave trough. However,
precip chances appear minimal at this time along with temperatures
near or slightly above average for this time of the year.
Afternoon convection may return to the region as early as
Tuesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1140 AM MDT Wed Apr 2 2025

Latest radar loop was showing showers wrapping around the upper
level disturbance in the upper midwest. These showers are
mostly clipping the KCDR TAF site, but some of this could bleed
into KAIA during the afternoon. These two sites will most likely
experience some MVFR conditions this afternoon, but these
ceilings should climb to the VFR category this evening. The
remainder of the TAF sites may see a few snow showers this
afternoon, but ceilings should generally stay in the VFR
category. Cannot rule out some patchy fog in the North Platte
Valley overnight which includes KBFF, but most locations should
have VFR conditions.

&&

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

&&

$$

SHORT TERM...SF
LONG TERM...TJT
AVIATION...REC