307 
FXUS65 KCYS 162232
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
432 PM MDT Sun Oct 16 2022

.SHORT TERM...(Late this afternoon through Tuesday night)
Issued at 225 PM MDT Sun Oct 16 2022

No changes in the large scale pattern this afternoon with the nearly
stationary broad upper trough over the eastern CONUS and upper ridge
over the Intermountain West. A dry northerly flow aloft prevailed with
mostly sunny to sunny skies. Temperatures ranged from the upper 40s
to lower 60s. Winds were north to northeast 5-15 kt with gusts to
near 25 kt in the southeast WY wind-prone zones.

Northerly to northwesterly flow aloft will persist with little change
in the synoptic scale pattern during the short term. There will be no
moisture to work with, so nil PoPs. Light winds, a dry boundary layer
and clear skies will promote ideal radiational cooling with freezing
temperatures and areas of frost over much of southeast WY. Temperatures
will moderate Monday with highs in the lower to mid 60s. Nearly identical
conditions forecast Monday night and early Tuesday morning with 20s
and lower 30s. The warming trend continues Tuesday with 700mb 
temperatures rising to 4C to 6C in the afternoon. Expect highs in the
60s to near 70F. Winds will remain relatively light Tuesday.

.LONG TERM...(Wednesday through Sunday)
Issued at 225 PM MDT Sun Oct 16 2022

Long term forecast remains on track with little changes in the 
Wednesday to Friday timeframe. Quiet but breezy weather expected for 
the latter half of the work week as an upper-level ridge sits just 
to the west of the Rockies. This will result in dry conditions with 
above average high temperatures through at least Friday. Mid 60s are 
expected for areas west of the Laramie Range. Areas to the east will 
see temperatures in the mid 60s to mid 70s, which is about 5 to 10 
degrees above average.

More forecast uncertainty is expected for the weekend. Both the 12Z 
deterministic GFS and ECMWF model runs seem to have shifted the 
timing of the front later than previous runs. Cold front looks to 
move through during the day on Sunday rather than Saturday night. 
The GFS also looks much wetter than previous runs which could lead 
to a pretty solid snowfall event for the Snowy and Sierra Madre 
Ranges. As for the lower elevations, precipitation type will likely 
be dependent on the time of day. Long range ensembles still show 
somewhat mild daytime temperatures, but nighttime lows will likely 
fall below freezing Sunday night for most locations. 

Lastly, cannot rule out the potential for a high wind event Friday 
night into Saturday out ahead of the cold front. Looks like our 
typical cold season high wind set up with tightening pressure and 
height gradients ahead of a strong cold front. Winds aloft at 750 mb 
reach 55 to 60 kts with good subsidence to bring them down to the 
surface. If the front weakens, the potential for high winds may 
decrease, but for now, upped the winds slightly Saturday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 429 PM MDT Sun Oct 16 2022

Pretty tranquil conditions next 24 hours with clear skies and
light winds. West winds returning Monday as a weak cold front
edges east. No weather impacts expected for next 24 to 48 hours.

&&

.FIRE WEATHER...
Issued at 225 PM MDT Sun Oct 16 2022

A dry northwesterly flow aloft will prevail through the week. Temperatures
will warm each day to above seasonal normals. No fire weather concerns
are anticipated through Tuesday with relatively light winds. Gusty winds
and afternoon relative humidities decreasing to 10 to 15 percent will
raise concerns with potential Red Flag conditions Wednesday through
Friday for much of the region. A trend toward cooler and wetter weather
returns next weekend.

&&

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

$$

SHORT TERM...MAJ
LONG TERM...SF
AVIATION...GCC
FIRE WEATHER...MAJ