789
FXUS65 KBYZ 180747
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
147 AM MDT Fri Oct 18 2024

.KEY MESSAGES...

- Precipitation tapers off today.

- Dry and warm this weekend and much of next week.

&&

.DISCUSSION...

Through Saturday...

Western CONUS trof continues to dig southward toward southern UT
and AZ. We remain in a region of moist southerly flow aloft and
there is a 90kt H3 jet analyzed lifting thru central MT (a bit to
our west) leaving us in its RRQ. The combination of this large
scale ascent and low level upslope flow continues to produce
mainly light precip over our western and southern upslope areas,
in addition to the far southeast corner of MT. Snow levels are
around 4000 feet in our west and 4500-5000 feet along the
Bighorns. It has been snowing persistently at Livingston and Red
Lodge for the past several hours (a dusting shown on local web
cameras) while Sheridan has seen just rain. Higher elevations have
seen accumulating snow and most snotels are showing anywhere from
0.50-1.00" of SWE since yesterday. We have winter highlights in
effect for the Beartooth-Absaroka and Bighorn Mountains, the
Paradise Valley, and the Beartooth/Red Lodge Foothills...and will
make no changes at this time.

Areas of mainly light precip will continue past sunrise then
should gradually diminish through the morning, as the trof to our
west becomes increasingly split. It appears that precip will stay
west and south of Billings from this point on. Today will also be
dry across our north. Additional snowfall of 1-3" is expected for
the mountains, with an inch or less along the foothills. Dew point
depressions are obviously quite low and localized early morning
fog is a possibility as well.

Look for temps to climb into the 50s today w/ clearing skies in
the afternoon. The trof digging to our west will form into a cut
off low near the four corners tonight. This leaves us in a drier
zonal flow which will persist tonight and Saturday. Look for lows
tonight in the mid 20s to upper 30s, then highs Saturday in the
60s (i.e. a return to warmer than normal). The only other forecast
issue is wind along our western foothills as downslope gradients
tighten tonight and mid level westerly flow increases to 30-35
knots. Have bumped up wind speeds/gusts to show 35-45 mph gusts
overnight into Saturday morning at the gap areas. The probability
of gusts exceeding 50 mph is 30%, but this is something to monitor
as it will be cold in YNP leading to high stability tonight.

JKL

Saturday night through Friday...

Quieter weather will prevail through the weekend and through
Monday. High temperatures are forecast to be in the upper 60s to
mid 70s Sunday and Monday. Dry conditions are expected through
much of Monday, before an approaching disturbance and cold front
bring a low to moderate (15-50%) chance for precipitation, Monday
night through Tuesday. Cooler temperatures will fill in across the
area on Tuesday, with highs in the 50s to 60F. Zonal flow will
give way to ridging, Wednesday into next weekend, resulting in
warm and dry conditions. High temperatures are forecast to be in
the 60s to low 70s, Wednesday through Friday.

Outside of temperatures and precipitation, breezy conditions are
anticipated around Livingston and Nye Sunday night into Monday
morning, as high pressure builds over Yellowstone and sets up a
favorable pressure gradient for gap winds. The current forecast
has gusts in the 20-40 mph range.

Matos/Arends

&&

.AVIATION...

A fall weather system will continue to bring light precipitation
to southern and western foothills areas early this morning. Look
for reductions to MVFR-IFR and even local LIFR with embedded lower
ceilings and potential fog. Sites KLVM and KSHR will be impacted
the most. Mountains will remain obscured thru the morning. Precip
will taper off today and flight conditions will improve to VFR
regionwide this afternoon and tonight. Look for gusty SW winds to
develop along the western foothills (i.e. KLVM) tonight, with
gusts near 40 knots possible after midnight. JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Sat     Sun     Mon     Tue     Wed     Thu
-------------------------------------------------------
BIL 053 036/066 044/072 046/073 042/060 037/067 041/070
    1/B 00/N    00/U    00/B    23/W    20/U    11/U
LVM 050 031/063 035/069 038/069 036/062 034/068 038/070
    3/O 00/N    00/U    01/B    33/W    10/U    11/U
HDN 055 029/069 036/073 039/075 039/062 034/068 036/072
    1/B 00/U    00/U    00/U    23/W    20/U    11/U
MLS 056 032/068 040/072 041/074 042/058 034/066 035/068
    0/B 00/U    00/U    00/U    32/W    20/U    11/U
4BQ 052 030/067 038/072 040/074 042/060 035/067 038/071
    3/R 00/U    00/U    00/U    12/W    20/U    11/U
BHK 054 029/067 038/073 040/074 039/058 031/064 034/067
    1/E 00/U    00/U    00/U    11/B    20/U    01/U
SHR 051 026/067 035/072 038/074 036/063 032/069 036/073
    6/R 00/U    00/U    00/U    12/W    20/U    11/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect until noon MDT today FOR
      ZONES 56-64-66.
     Winter Storm Warning in effect until 3 PM MDT this afternoon
      FOR ZONE 67.
     Winter Weather Advisory in effect until 6 PM MDT this evening
      FOR ZONE 171.
WY...Winter Weather Advisory in effect until 6 PM MDT this evening
      FOR ZONE 198.

&&

$$
weather.gov/billings