Ranchettes, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

231
FXUS65 KCYS 031706
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1006 AM MST Tue Dec 3 2024

.KEY MESSAGES...

- Mild, above average temperatures are expected on Tuesday with
  dry and breezy conditions.

- Minimal to no precipitation chances expected during much of the
  work week. Near-normal to above average temperatures also
  expected during this time.

- Precipitation chances and the potential for high winds return
  to the area on Sunday. There is a chance for widespread
  snowfall early next week across southeast Wyoming and western
  Nebraska.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 215 AM MST Tue Dec 3 2024

Clear skies and fairly mild conditions are ongoing as of 0830Z, with
not a single cloud detectable on GOES16 satellite across the entire
CWA. Light, downsloping winds have developed at several locations in
southeast Wyoming, leading to overnight lows moderating out slightly
higher than forecast. Most locations in southeast Wyoming are in the
30s and 40s, with teens and 20s present across the Panhandle behind
a front the moved through on Monday. Relatively mild temperatures
are expected over night across southeast Wyoming, despite the clear
skies, as downsloping winds are likely to continue over the next few
hours. Much cooler temperatures will be seen across the western
Nebraska Panhandle.

Fairly benign weather is expected for the middle part of the week,
with mostly sunny skies and warm temperatures for the region Tuesday
through Thursday. The synoptic pattern remains relatively unchanged,
with a large trough over the eastern CONUS and a stout ridge over
the western CONUS. Sandwiched between these two features is
northwest flow aloft, ushering in quiet weather and slightly above
average temperatures. Gusty winds are likely through the day today
as 700mb gradients tighten slightly and a 700mb jet develops aloft.
Craig to Casper gradients are modest, approaching 60m, but with the
700mb jet remaining around 30kts, high winds are not expected today.
Elevated winds cannot be ruled out, especially at Bordeaux, as the
700mb jet increases towards 30kts, but should remain well below high
wind criteria. With subsidence aloft from the upper-level ridge,
mostly sunny skies are expected across the region. Temperatures will
remain above average for this time of year, especially in locations
downstream of the Laramie Range as downsloping winds act to increase
temperatures in these area. Highs for today will be in the 40s and
50s west of the Laramie Range and 50s to 60s east of the Laramie
Range. A weak cold front will traverse across the region this
evening, cutting off the elevated winds and decreasing temperatures
slightly for Wednesday.

Much of the same is expected for Wednesday, just with slightly
cooler temperatures thanks to the cold frontal passage later this
evening. Temperatures will drop into the upper-40s to low-50s east
of the Laramie Range and remain in the 40s west of the Laramie
Range. The synoptic pattern remains unchanged, with northwest flow
aloft still dominating the region. The western CONUS ridge axis will
slowly slide easterly throughout the day, leading to slightly warmer
temperatures than might have been expected after a cold frontal
passage. Additionally, subsidence from the ridge will keep skies
mostly clear once more for Wednesday. 700mb winds remain mostly
calm, except for a slight increase across norther Carbon and Albany
counties early Thursday morning. Therefore, fairly calm winds will
be present Wednesday with a slight increase towards early Thursday
morning. Once again, high winds are not likely as Craig to Casper
gradients drop into the 30s and 40s, and the 700mb jet remains
weak. Overall, should be a pleasant middle of the week.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 215 AM MST Tue Dec 3 2024

Medium range models show a quiet weather pattern over the
western U.S. late this week and into next weekend. All models
show a ridge of high pressure aloft remaining over the west
coast and the Great Basin Region, with a weak upper level low
remaining stationary near the New Mexico/Arizona border. A few
deterministic models and ensembles show a Rex Blocking
attempting to form west of Wyoming next weekend, but any
blocking is expected to be brief as a strong Pacific storm
begins to move southeast towards the PAC northwest coastline on
Saturday. 700mb temperatures across Wyoming and western Nebraska
are expected to remain above 0c Thursday through Saturday, with
values closer to +5c on Saturday. This will likely result in
high temperatures between 10 to 20 degrees above average for
this time of the year (average is generally in the upper 30s to
mid 40s) with highs ranging from the low to mid 40s west of I-25
to the 50s and low 60s east of I-25. Once the Pacific system
starts heading inland late Saturday and into Sunday, windy
conditions are expected across most of the area with the wind
prone areas approaching High Wind criteria. Kept the strongest
winds near Bordeaux along I-25 and the Elk Mountain/Arlington
area along I-80.

As we enter the extended, all models and most ensemble members
show a pattern change as the Pacific storm system moves into the
Intermountain West and the Front Range early next week. Primary
forecast concern will be the primary trough axis aloft and the
potent shortwave disturbance associated with the storm. The GFS
is the most aggressive, showing this feature translating
southeast near the four corners region and aiding in the
developing of lee-side cyclogenesis at the surface. This
solution would result in a decent Front Range winter storm if
the GFS would verify. The ECMWF and Canadian are about 24 hours
later compared to the GFS, and do not show the rapid
intensification quite as much. Most ensemble data, including
the GEFS, still show a more progressive system moving across the
area with some differences in timing. The 00z GFS is a major
outlier, so will keep POP between 15 to 30 percent for most
areas and near 55 percent for the mountains. Did increase POP a
little higher than the NBM due to reasonable run to run
consistency on the timing of the precipitation. One thing
models do agree: it will be much colder with highs returning to
below average for this time of the year. There is some
uncertainty when the colder airmass will get here, so trended
temperatures lower each day Sunday through Tuesday of next week
for now.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1001 AM MST Tue Dec 3 2024

Clear skies and VFR conditions expected at all terminals today.
Winds will remain generally light with westerly flow in
southeast Wyoming mountain terminals. Some wind shear is
possible in the NE panhandle overnight as surface winds diminish
and winds aloft remain stronger out of the north-northwest. This
wind shear in the NE terminals will subside by Wednesday
morning.

&&

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

&&

$$

SHORT TERM...AM
LONG TERM...TJT
AVIATION...MAC