783
FXUS65 KCYS 011137
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
537 AM MDT Thu Oct 1 2026

.KEY MESSAGES...

- Warmer temperatures and drier conditions will continue into
  the weekend.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 235 AM MDT Thu Oct 1 2026

Not much to speak of in the short term as benign weather is expected
through the end of the work week. Cloud cover will gradually
decrease throughout the morning on Thursday as the low pressure
system over Kansas continues to move eastward. Upper-level ridging
over southern California will also gradually shift eastward into the
Four Corners region, helping to move clouds out of the area.
Temperatures will be roughly the same as yesterday with highs mainly
in the 60s to low 70s. Today will mark the start of a drying trend
with the strengthening ridge keeping precipitation chances at bay.
Heading into the overnight hours, a low-level jet will develop over
the eastern half of the forecast area, leading to breezy conditions.

Breezy conditions will continue into the day Friday as flow aloft
becomes more zonal. Zonal flow will lead to downslope, helping warm
temperatures across the area. Zonal flow will also help usher in
warmer and drier air aloft. High temperatures on Friday will be
anywhere from 5 to 15 degrees warmer than Thursday. These
temperatures will be about 10 degrees above average for the
beginning of October. On top of the warming temperatures, conditions
will get drier with mostly sunny skies and no precipitation chances
anticipated. Overnight lows Friday night will also be on the milder
side.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 151 PM MDT Wed Sep 30 2026

Global ensemble forecast guidance remains generally unchanged
compared to yesterday regarding the long-term forecast period from
this weekend into next week. High confidence exists for tranquil
weather through much of the long-term period. Large-scale ridging
will dominate the weather pattern over the western CONUS resulting
in generally mild above-average temperatures and limited
precipitation chances over southeast Wyoming and western Nebraska.
This ridging pattern continues to be a result of the highly active
tropical pattern over the eastern Pacific. Numerous EPAC and CPAC
tropical storms will continue to move west and then recurve to the
north in the mid-latitudes of the central Pacific, resulting in
potent synoptic troughing over the Bearing Sea/Gulf of Alaska. This
setup then drives downstream ridging over western North America,
which is apparent once again in today`s ensemble mean guidance. As
mentioned yesterday, these types of stable-synoptic-wave patterns
can often persist for weeks or more, locking in high-confidence
forecasts over much of the west including our region.

Local details remain largely unchanged in the forecast. Above-
average temps are expected each day from Saturday onward. High
confidence exists in temps around 5 degrees above average this
weekend (low to mid-70s east of the mountains) and highs 10 to 15
degrees above average through next week. The one new exception in
the forecast in today`s guidance is a very weak wave in the overall
ridge which may move through on Tuesday. Ensemble guidance has a
very high amount of spatiotemporal dispersion with regard to this
system. Some members do not even show this wave, and others bring it
through strong enough to produce some weak showers over the higher
terrain of southern Wyoming and northern Colorado. We will opt for
the driest solutions for now given recent model performance with
similar systems. Mild temps even during the overnight hours should
continue to hold off the first frosts for any populated areas
outside of the mountains. Afternoon RH values will drop to near or
slightly below 20% throughout the weekend during the afternoon hours
across all of southeast Wyoming and portions of the Nebraska
panhandle. However, generally light surface flow out of the west
less than 20 mph will likely preclude the need for any fire weather
headlines. The synoptic pattern described in both today`s and
yesterdays discussion will continue to result in high forecast
confidence throughout the entire long-term period with limited
societal impacts expected.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 537 AM MDT Thu Oct 1 2026

Major aviation impacts are not anticipated today. However, there are
low probabilities for low CIGS this morning, mainly for terminals
east of the Laramie Range. Any cloud cover is likely to clear by the
afternoon. Aside from that, breezy conditions can be expected
throughout the day. A low-level jet will develop Thursday night,
leading to windy conditions for terminals in the Nebraska
panhandle.

&&

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

&&

$$

SHORT TERM...SF
LONG TERM...MAC
AVIATION...SF