183 
FXUS65 KCYS 071104
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
504 AM MDT Fri Oct 7 2022

.SHORT TERM...(Today through Sunday)
Issued at 245 AM MDT Fri Oct 7 2022

Stout upper ridge remained parked over the western CONUS with a
deep upper trough over the Great Lakes and Midwest. The cold front
that moved through southeast WY and the NE Panhandle Thursday 
extended from just west of the Laramie Range into southeast CO. A
moist upslope northeasterly flow produced widespread low stratus,
drizzle and patchy fog, dense at times, over parts of southeast 
WY. Isentropic lift and weak instability (MUCAPE up to 200 j/kg) 
generated scattered showers and a few embedded thunderstorms from 
the eastern WY plains through the southern 2/3 of the NE Panhandle.
Rainfall amounts between 0.20 and 0.50 were observed since 6 PM 
Thursday. Temperatures ranged from the mid 30s to mid 40s. 

The cool and moist weather pattern will persist today along and
east of the front. The showers will taper off early this morning
over the plains, with clouds slowly decreasing from west to east
this afternoon. High temperatures will only rise into the lower 
and mid 50s east of the Laramie Range, with upper 50s and lower
60s west of the front. The front will weaken and shift east into
western NE this evening. Mostly clear skies and light winds will
create ideal radiational cooling with low temperatures tonight
falling into the lower and mid 30s. More widespread frost is
likely east of the Laramie Range, and a Frost Advisory is in
effect from midnight tonight to 8 AM Saturday.

The northwesterly flow aloft will prevail through the weekend.
700mb temperatures will moderate from 0C to 4C today, to 4C to 
8C Sunday. High temperatures will moderate into the 60s Saturday,
and mid 60s to lower 70s Sunday. No precipitation is forecast.
Saturday night will not be as cool with low temperatures in the
mid 30s to near 40. Frost coverage early Sunday morning will be 
more patchy compared to early Saturday morning.

.LONG TERM...(Sunday night through Thursday)
Issued at 245 AM MDT Fri Oct 7 2022

Complete changes in the long term as model guidance really shifting
a low pressure system further west.

Starting off Sunday night...CWA will be under a ridge of high pressure.
Low that was in Idaho previously...now forecast over northern California.
Weather looks pretty benign with light winds under this high pressure.
700mb temperatures will be fairly warm at +6 to +7C.

Upper low tracks into southern California Tuesday. Dry cold front
expected to move through Tuesday afternoon as a fairly strong upper
shortwave tracks into eastern Montana. 

Confidence in any precip occurring is fading fast with this setup.
Followed NBM PoPs and even cut PoPs for Tuesday night into Wednesday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 501 AM MDT Fri Oct 7 2022

Cold front has pushed west past KLAR into Carbon County near KRWL
at 5 AM this morning. Pesky stratus bringing IFR/LIFR conditions
to some areas with MVFR conditions elsewhere. Stratus could stick
around through 18Z before lifting.

&&

.FIRE WEATHER...
Issued at 245 AM MDT Fri Oct 7 2022

A cold front will remain stalled along the Laramie Range today then
shift east into western Nebraska this evening. Scattered showers over
the Nebraska Panhandle will end shortly after sunrise. It will be cooler
than normal east of the Laramie Range today with high relative humidities.
A warming and drying trend commences Saturday and continues through
early nest week. Minimum relative humidities will decrease to 20 to
30 percent this weekend, and 15 to 25 percent Monday and Tuesday. Winds
will remain light this weekend, becoming breezy Monday and Tuesday.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Frost Advisory from midnight tonight to 8 AM MDT Saturday for 
     WYZ101-102-107-108-118-119.

     Dense Fog Advisory until 9 AM MDT this morning for WYZ106-
     116>118.

NE...Frost Advisory from midnight tonight to 8 AM MDT Saturday for 
     NEZ002-003-019>021-054-055-095-096.

&&

$$

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