439
FXUS65 KCYS 032017
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
217 PM MDT Fri May 3 2024

.KEY MESSAGES...

- A cold front will move through the region today with another
  round of shower activity in the mountains. Snow levels will
  remain above 6500 feet.

- Breezy to windy, and cooler weather expected for Monday
  through Wednesday, with isolated to scattered late day showers
  and thunderstorms.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 159 PM MDT Fri May 3 2024

As the cold front continues to move east across southeast Wyoming
and western Nebraska, we saw a weaker dryline develop ahead of it
stretching from near Cheyenne to Alliance with southerly winds and
dewpoints in the upper 40s ahead of it, and north to northwest winds
and dewpoints in the 20s to low 30s behind it. A line of
thunderstorms developed along it with pockets of 40 knots of shear
and CAPE values near 1000 J/kg, but it was quickly undercut by the
approaching cold front and died out nearly as fast as it developed.
Rawlins saw some moderate to heavy snow showers this morning, and
while they are very slowly moving east, they will likely not impact
areas east of Interstate-25, producing very little precipitation
between the Laramie Valley and the Interstate-25 corridor,
including Cheyenne. The primary impacts to areas between the
Laramie Valley and the Interstate-25 corridor for the rest of
the day will be occasional light rain showers and snow showers
possible above 6500 feet, but mainly strong gusty winds with
wind gusts 35 to 45 mph possible and colder temperatures
tonight.

Saturday the trough moves off to the east as a ridge approaches
southeast Wyoming and western Nebraska bringing high temperatures in
the 50s to low 60s with clear skies. Winds will likely be light with
south to southeast wind gusts 20 to 30 mph possible across the High
Plains. Overall a pleasant, cool Saturday expected.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 159 PM MDT Fri May 3 2024

Warm day Sunday will transition to a prolonged windy and slightly
cooler pattern as a storm system slow churns across Intermountain
West beginning Monday and persisting into Wednesday. Looking like
there is a chance for elevated winds with intermittent periods of
high winds to impact the wind prone areas and much of the I-25
corridor and areas across the Nebraska Panhandle.

The long term forecast will begin with a nice day on tap for Sunday
as upper level ridging settles across the area allowing for 700mb
temperatures to climb into the 7-11C which will translate to
afternoon high temperatures climbing into the upper 60s to mid 70s
for locations east of the Laramie Range and into the Nebraska
Panhandle. Ahead of the next storm system increasing clouds and low
level moisture will lead to the development of some high elevation
snow showers across Carbon county and the Sierra Madres. Not
expecting much in the way of impactful accumulation with these snow
showers.

A combination of a slow moving and strengthening storm system
moving to our south and some lee troughing will be the catalysts
from a prolonged period of windy conditions across much of SE
Wyoming and the Nebraska Panhandle. Not much change regarding the NBM
probabilities as they continue to show a period from Monday through
Wednesday night where a large swath of SE Wyoming and the Nebraska
Panhandle of seeing a (>80%) chance of seeing wind gusts greater
than 40 mph Monday through Wednesday with lower intermittent
probabilities of periodically seeing wind gusts up to high wind
criteria (>58 mph). The wind prones should see more consistent wind
gusts above high wind criteria so if we can stay underneath the jet
energy aloft and keep those gradients tight then I`d expect we may
begin to issue high wind highlights in the coming forecast updates.
The extent of the winds and magnitude as stated above will be the
track of the low pressure system to our south as a more southerly
shift would pull the bulk of the high winds aloft further south into
Colorado and this cut down on both the magnitude and duration of the
wind threat. This track to the south would also pull the wrap around
moisture out of northern Wyoming and southern South Dakota and
shift it more into our area increasing the precipitation chances
heading into next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1110 AM MDT Fri May 3 2024

Snow showers have been moving through KRWL with an associated
cold front, dropping conditions to IFR and will likely continue
over the next few hours, clearing up by this evening. These
snow showers will continue moving east and will begin to affect
KLAR over the next two hours, and potentially KCYS in the next
four hours. Precipitation type will more likely be rain by the
time it reaches KCYS. In addition, thunderstorms will likely
begin developing in the eastern Nebraska panhandle this
afternoon, if they were to develop and affect any terminal, it
will most likely be KAIA. As the cold front moves across
southeast Wyoming and western Nebraska, winds will turn more
northerly with strong wind gusts 30 to 40+ knots.

&&

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

&&

$$

SHORT TERM...LEG
LONG TERM...AW
AVIATION...LEG