Expires:No;;141028
FXUS65 KCYS 040509
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1009 PM MST Tue Dec 3 2024

.KEY MESSAGES...

- Above average temperatures will continue each day through the
  end of the week with dry weather expected.

- High winds return on Sunday into Monday with cooler
  temperatures and a chance for precipitation on Monday.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 242 PM MST Tue Dec 3 2024

A ridge of high pressure remains in control over the northern
Rockies this afternoon. High temperatures have run nearly 20
degrees above average east of the mountains including locations
such as Cheyenne and Scottsbluff. Expect clear skies to remain
in place overnight with lows running around 5-10 degrees above
average. 
 
More of the same on Wednesday as high pressure remains in place,
perhaps drifting a bit farther to the west as the jet stream
backs west over the northern plains. Heights may end up a few
ticks lower on Wednesday as a result of this jet stream wobble,
and a few high clouds may help keep high temps around 5 degrees
lower. Overall forecast confidence is extremely high through the
short term. Only adjustments made in this forecast package were
raising high temps a few degrees above consensus blends.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 242 PM MST Tue Dec 3 2024

High pressure remains in control over the west through the first
half of the long term forecast. Expect afternoon highs 10-15
degrees above average from Thursday through Saturday. A weak
impulse passing well to the east may briefly tighten pressure
gradients enough to increase winds over the Snowy Range
foothills into the 40 knot range on Thursday night, otherwise
expect a fairly calm stretch wind-wise as well for southeast
Wyoming. 

By Sunday, a trough will move inland along the Pacific northwest
coast. Fast jet stream flow aloft ahead of this system will
spread eastward through the Rockies. Local machine learning
guidance suggests a period of high likelihood of winds exceeding
60 mph in the Snowy Range Foothills and possibly the Laramie
Range/eastern foothills on Sunday into Monday. This is a pretty
long-range forecast for now, with the exact timing and location
of the jet/fast flow still a bit in question. Another major
question with this system will be precipitation chances. It is
likely that a deep plume of anomalous PW will move inland
through the Great Basin and toward the mountains of the Front
Range. For now, it looks like any precipitation with this event
will be driven mainly by the Pacific moisture stream favoring
mountain and high-elevation snows. However, a minority of
ensemble members do form a high-plains surface low. In this
less-likely scenario, easterly upslope flow on the north side 
of this low could result in accumulating snowfall for areas east
of the Laramie Range into the NE panhandle. However, this 
solution is still in the minority of ensemble outcomes but is 
worth mentioning. The one thing that is certain with this storm 
will be colder temperatures starting on Sunday. By Monday, 
expect below-average weather across the entire region. 
Adjustments were made to raise temperatures early in the long-
term, with minor upticks to the wind forecast as well.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1007 PM MST Tue Dec 3 2024

VFR conditions with no weather impacts expected for southeast
Wyoming and Nebraska Panhandle airports. High pressure remains
in control of the weather for the next 24 hours and beyond.

&&

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

&&

$$

SHORT TERM...MAC
LONG TERM...MAC
AVIATION...GCC