543
FXUS65 KBYZ 231716
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
1016 AM MST Mon Dec 23 2024

.KEY MESSAGES...

- Above normal temperatures continue through the week, periodic
  windy conditions along the western foothills.

- Travel conditions look good leading up to Christmas with low
  rain chances today and tomorrow.

- Changes in the weather pattern may be in store by the end of the
  month, but there is a lot of uncertainty.

&&

.DISCUSSION...

Through Tuesday Night...

Today we will be under short wave ridging with increasing clouds
due to an incoming trough. Temperatures will be above average with
values in the 40s. This morning, 20-30% Pops will move into the
western zones and move to the east throughout the afternoon and
early evening. Precipitation values are expected to remain light
with HREF keeping 90th percentiles below 0.05 inches. Temperatures
will be warm enough for precipitation to stay as rain for lower
elevations.

Tuesday will see the return of shortwave ridging with temperatures
similar to today. Increasing clouds will be seen ahead of another
incoming trough. Locations west of Rosebud County will have 30-50%
Pops Tuesday night through early Wednesday. Precipitation amounts
will be heavier than todays system with locations east of Rosebud
County having a 20-30% of getting >0.1 inches of precipitation.
Temperatures will be warm enough for lower elevations to receive
rain with snow being limited to the mountains and higher hills.
Torgerson

Wednesday through Monday...

The second half of the weekend is more of the same, with above
normal temperatures, mostly dry conditions (across the lower
elevations), and breezy winds.

On Christmas, despite a dynamic trough cross the country, the far
southern extent of it across the 4 corners regions and staying
south keeps all moisture potential with it as well, leaving us
with only a small (10-20%) chance for light rain across the lower
elevations, and some snow in the mountains. Despite looking like a
brown Christmas, it will at least leave travel conditions good
for those driving that day.

Christmas night and onward continues with a trend of an overall
ridge being in place, with quick waves moving across the area.
This will leave temperatures above normal, with quick, small
chances of light rain across the lower elevations and some snow
potential each day over the mountains. It also keeps gap wind
potential going for the foothills west of Billings, so take
caution if traveling along I-90 through Big Timber and
Livingston, and along HIghway 191 from Big Timber through
Harlowton.

Still signs of a pattern change, but latest ensembles lean
towards a flatter flow vs a dominat trough, which while it would
still bring about lower temperatures and higher precip potential,
doesn`t scream some large winter storm at this time. Lotta time
left before the start of 2025 though (when this pattern change is
expected). VErtz
&&

.AVIATION...

18z TAF update...

A weak wave is moving through right now which is producing some
light showers near KBIL this morning and may stick around for a
few more hours. KLVM will set up a gusty wind from 250 degrees
starting around 03z and should also have VCSH for most of the
period. Mountain snow will cause partial mountain obscuration as
well. VFR conditions should prevail at all sites.

WMR

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Tue     Wed     Thu     Fri     Sat     Sun
-------------------------------------------------------
BIL 049 028/046 033/047 027/045 030/047 030/048 031/048
    2/W 10/B    42/R    00/B    22/O    12/O    11/B
LVM 047 029/049 033/043 027/043 028/044 029/047 033/049
    4/W 10/N    62/S    01/N    22/S    24/O    22/R
HDN 047 026/048 029/047 023/045 027/048 027/048 029/049
    2/W 20/B    23/O    00/B    22/O    12/O    11/B
MLS 044 026/045 029/045 022/043 028/045 026/046 028/045
    1/B 20/B    01/E    00/B    01/B    01/B    00/B
4BQ 048 029/048 032/044 025/047 028/047 027/046 030/048
    0/B 20/U    01/E    00/U    01/B    11/B    10/B
BHK 044 025/045 026/041 021/044 025/043 022/043 024/042
    0/U 20/U    00/E    00/U    01/B    01/B    00/B
SHR 050 024/050 026/045 021/048 024/048 023/049 025/051
    1/E 20/U    12/O    00/B    12/O    11/B    11/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.

&&

$$
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