Area Forecast Discussion
Issued by NWS Billings, MT

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938
FXUS65 KBYZ 261454
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
854 AM MDT Thu Sep 26 2024

.KEY MESSAGES...
- Becoming breezy behind a dry cold front today.

&&

.UPDATE...
Satellite imagery shows a Pacific shortwave moving west-to-east
thru central MT, with only scattered mid-high clouds eking into
our forecast area. Surface analysis shows a cold front into our
west, and winds from Big Timber to Harlowton are starting to
respond w/ increasing westerly winds. The front will progress
eastward and reach southeast MT by early afternoon. NW-N winds
will be breezy behind the front w/ widespread 20-35 mph gusts. The
combination of the wind along with still hot temps and sub-20%
humidity will be problematic with regard to fire weather, so
current Red Flag Warning for Sheridan and southeast MT looks to be
on track. Instability along the trof axis may generate some mid
cloud and perhaps virga a bit later today, but the air mass is
quite dry so no real chance of precip today. JKL

&&

.DISCUSSION...

Through Friday night...

Satellite imagery shows a poorly organized trough moving inland
along the Pacific NW coast with an associated cloud leaf and
showers moving through Idaho into western Montana. This system
will move across Montana today, with most of the energy up in
Canada we do not expect any precipitation, but generally wind
impacts. Look for an initial wind shift during the morning with
southwest winds turning west, then becoming north/northwest in the
afternoon with a secondary push of cooler air. Some areas may see
gusts flirt with 30 mph at times today, especially near the
foothills. The atmospheric column looks to dry to support any
measurable precipitation, though some high based virga is possible
here and there over the central zones. Aided by downslope flow,
we should still see temps into the 80s at most locations today
despite the cool frontal passage, and maybe even approach 90
degrees in the southeast. Winds will calm down tonight with lows
in the 40s.

Nothing to remarkable about Friday. High pressure aloft will
prevail to our south with weak zonal to anti-cyclonic flow over
our region. Highs will remain well above normal in the lower to
mid 80s.

Red Flag Warning remains in place for zones 131 (Ashland Ranger
District & Northern Cheyenne) and 274 (Sheridan Co) as well as
zone 133 (Sioux Ranger District) in southeast Montana and
northwest South Dakota through 600 PM. We expect temps in the mid
80s to around 90F, RHs 15-20% and W-NW winds gusting to 30 mph in
these areas. Fuels in these locations still appear to be primed
for fire starts (due to recent man made fires). BT

Saturday through Thursday...

The weekend will be warm and dry, with breezy conditions on
Sunday, as upper ridging gives way to upper troughing. Hot Dry
Windy highlights Sunday as a possible fire weather day, so will
need to keep an eye on this period. Temps could reach the 90s
again on Sunday, with NBM showing a 30% chance of reaching 90
degrees in KBIL to a 98% chance in KSHR. These temps will approach
or possibly exceed record highs. Upper trough moves across the
area on Monday. Deterministic models showed a strong cold frontal
passage Sun. night, with a back door cold front moving into the
area on Monday. Breezy conditions continue through Monday, but
Monday will be much cooler with highs in the 60s, which will help
with fire weather concerns. Other than a slight (20%) chance of
showers over the northern tier of the forecast area Sun. evening,
conditions will be dry through Monday.

Ensembles patterns were in disagreement for Tuesday and ranged
from a trough to a ridge. Zonal flow or ridging was progged for
Wednesday. NBM was dry with around normal temps both days. Ridging
or NW flow were in the ensembles on Thursday. Other than a slight
chance of showers W of KBIL Wed. night, with possible mountain
snow showers, the forecast remained dry. Temps will be near normal
on Wed. with cooler conditions Thursday. Arthur

&&

.AVIATION...

Dry Pacific cold front will push across the area today, bringing
breezy west then northwest winds in the late morning and
afternoon. Expect widespread 20-30 knot gusts. Winds will decrease
quickly after sunset. Otherwise, VFR will prevail over the next 24
hours. JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Fri     Sat     Sun     Mon     Tue     Wed
-------------------------------------------------------
BIL 084 050/084 051/083 053/088 047/062 040/074 048/072
    0/U 00/U    00/U    00/B    11/U    10/U    00/U
LVM 080 046/084 047/085 052/086 038/064 037/076 044/072
    0/N 00/U    00/U    00/N    11/U    10/U    01/U
HDN 086 047/085 048/086 050/092 045/063 037/075 044/073
    0/U 00/U    00/U    00/U    11/U    10/U    00/U
MLS 083 048/084 052/087 055/090 048/061 039/069 046/069
    0/U 00/U    00/U    00/U    11/U    10/U    00/U
4BQ 091 049/087 052/089 059/094 050/062 039/072 046/072
    0/U 00/U    00/U    00/U    00/U    10/U    00/U
BHK 086 044/086 049/088 054/090 045/063 035/068 042/069
    0/N 00/U    00/U    00/U    00/N    10/B    00/U
SHR 091 046/087 050/089 052/094 044/064 035/076 042/075
    0/U 00/U    00/U    00/U    00/U    10/U    00/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Red Flag Warning in effect until 6 PM MDT this evening FOR
      ZONES 131-133.
WY...Red Flag Warning in effect until 6 PM MDT this evening FOR
      ZONE 274.

&&

$$
weather.gov/billings