Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 012349

Area Forecast Discussion
National Weather Service Cheyenne WY
549 PM MDT Sat Oct 1 2022

.SHORT TERM...(This evening through Monday night)
Issued at 200 PM MDT Sat Oct 1 2022

Upper low currently located near the Wyoming/Idaho state line. Low
is spinning off another piece of energy into Carbon and Albany
Counties this afternoon. Have been getting moderate rain reports
out of Rawlins and Dixon late this morning and early afternoon.
This band has shifted east and is now located along a line from
Muddy Gap to Elk Mountain to Laramie. More convection in north
central Montana moving northeast along this boundary and will
likely bring rainshowers and isolated thunderstorms to the Laramie
Range and points east as the afternoon progresses.

Looking at simulated radar from the HRRR and RAP...line of showers
and storms slowly shifts east across the Laramie Range into the
I-25 Corridor by 23Z or so...shifting further east to
Lusk/Scottsbluff/Kimball by 01Z. Showers persist in the Panhandle
through 06Z tonight. Tried to reflect this in the PoP forecast
this afternoon and evening.

Upper low tracks northeast into western Montana Sunday. 80kt jet
max moves across the CWA late morning into the afternoon.
ECMWF/SREF and NAM showing another active afternoon Sunday with
showers and isolated thunderstorms. Did go pretty high on PoPs for

One more day of unsettled weather Monday as low tracks into
eastern Montana and trough axis moves across the CWA. Still have
good chances for afternoon and evening showers and storms as
this trough axis moves through.

.LONG TERM...(Tuesday through Saturday)
Issued at 200 PM MDT Sat Oct 1 2022

The extended forecast includes near seasonal temperatures with
multiple opportunities for precipitation across the cwa. The cut-off
ULL will ultimately become absorbed in the steering flow aloft and
begin to push to the east across the Central Plains by late Tuesday.
CAA will continue to be present on Tuesday as cloud cover will be
slow to move out of the region. 700mb temperatures will range from
+2C to -2C on Tuesday and +4C to -2C on Wednesday. Daytime highs
struggle to reach the 60s by the afternoon hours across most of the
forecast area as there will likely be a weak cool front sagging to
the south. Lingering rain showers will be possible during this time
until the upper level low pushes east. Wednesday will see a return
of mostly sunny skies, which will likely be the first day to see a
full day of mostly clear skies since the previous weekend. This is
in response to an upper level ridge amplification across the Four
Corners region of the CONUS toward our cwa. Afternoon highs will
range from the 60s to the low 70s across the lower terrain, and
slightly cooler in the higher elevations. The upper level ridge will
begin to become flattened by Thursday, and northwest flow aloft will
allow for a weak shortwave to potentially clip the cwa by Thursday
night into early Friday. More of the same is likely for Friday into
Saturday as the northwest flow aloft will assist with another
potential shortwave bringing moisture to the area. Additionally,
tropical moisture from the Pacific will be lingering across the Four
Corners area by next weekend, per the extended model guidance, and
could act as a monsoon surge for precipitation opportunities to
round out the first 10 days of the month.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 544 PM MDT Sat Oct 1 2022

A line of showers and thunderstorms is currently moving across the
area, and is about to cross the WY/NE border. Expecting VCTS near
Nebraska terminals as this moves through with winds turning
westerly as it comes through. Timing looks like 0030z-02z for
KBFF, then between 02z and 04z for the other NE terminals, but a
few showers/storms could develop both in front of and behind this
line. Expect shower activity to wane in the NE panhandle after
midnight. An area of low clouds could develop near KBFF/KAIA
around 10z through 14z, but confidence is low at this time. Quieter
in Wyoming overnight, but could see shower activity re-
developing around around 08z. Another round of scattered showers
and thunderstorms is expected on Sunday afternoon.


Issued at 200 PM MDT Sat Oct 1 2022

Minimal fire weather concerns through at least Tuesday with cool
temperatures and high humidity. Cold front moved through last
evening...bringing fairly widespread rainfall and cool
temperatures. Upper low with this front takes its sweet time
moving through northern Wyoming and southern Montana...which will
bring continued chances for wetting rains and cool temperatures
into Monday. Finally dry out Tuesday...but cool temperatures and
higher humidity remains. No fire weather concerns expected.




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