Gardiner, Montana Weather Forecast Discussion

297
FXUS65 KBYZ 262310
AFDBYZ
Area Forecast Discussion
National Weather Service Billings MT
510 PM MDT Fri Sep 26 2025
.KEY MESSAGES...
- Warm and dry conditions Saturday through Monday. High temps
  mostly 80s each day.
- Precipitation potential gradually increase next week, starting
  Monday in the west then regionwide Tuesday and Wednesday. Temps
  expected to stay above normal through Wednesday.
&&
.DISCUSSION...
Through next Friday...
Tonight & Saturday: We have seen modest visibility reductions in
wildfire smoke today, due to post-frontal subsidence and mixing.
As winds veer to the N-NE-E, it is possible some near surface
smoke becomes dammed against the foothills tonight, while eastern
areas see improvement. Air quality, which has degraded to
"moderate" at Billings and Miles City, should improve Saturday
with backing flow aloft and deeper mixing. Temps tonight will be
seasonable (lows in upper 30s to mid 40s), then Saturday we jump
back up to the lower 80s as the upper ridge becomes dominant
again.
Sunday and Monday: Upper ridge brings continued warm & dry weather
on these days, but the southerly flow will spread monsoon
moisture northward ("monsoon moisture" is not something we should
be discussing at the end of September, but oh well). Thus, we
could see weak convection over the southern mountains Sunday
afternoon/evening, then a bit more of our west Monday. The risk of
lightning is low, but any sort of downdrafts will produce gusty
and erratic surface winds and this is something to monitor with
regard to fire weather. Otherwise, look for high temps mostly in
the 80s.
Tuesday through Friday: Finally some changes as the ridge breaks
down, but the Pacific flow with near to above normal heights will
keep temps above normal thru Wednesday. Cooling to near normal is
expected to end the work week, but ensemble spread is fairly high
by then. Regarding precipitation, there is decent model consensus
for a shortwave passage in the late Tuesday into Wednesday time
frame, and ensembles show a fair QPF signal here. Again, the air
mass will remain mild and any chance of mountain snow will be
over the high elevations (>10kft as it currently looks). For now,
we are talking about a 20-50% chance of showers and a 10-40%
chance of a tenth of an inch of rain or more (highest west). So,
nothing significant. Beyond Wednesday, there may be brief period
of shortwave ridging before another Pacific wave arrives in some
fashion at the end of the week. The late week trof may be a little
deeper.
Finally, it should be noted that the tropics are active, including
over the western Pacific, and over time any tropical storms/
hurricanes/typhoons could alter the longwave pattern over North
America. This is likely a source of the tremendous spread in
ensemble temps/QPF we see in the 1-2 week time frame. Stay tuned.
JKL
.AVIATION...
00z Discussion...
Winds should gradually weaken throughout the evening with all
sites seeing winds sustained below 15 kts by 03z. Slant range
visibility will be reduced for the entirety of the period due to
wildfire smoke with a slight improvement possible later in the
day Saturday. VFR conditions will prevail, however, any site may
see a brief reduction down to MVFR in pockets of heavier smoke.
Mountains will be partially obscured due to wildfire smoke. WMR
&&
.PRELIMINARY POINT TEMP/POPS...
Sat     Sun     Mon     Tue     Wed     Thu     Fri
-----------------------------------------------------------
BIL 047/081 051/084 055/083 057/080 054/075 051/072 047/068
    00/K    00/U    00/U    11/B    32/W    21/B    22/W
LVM 040/080 045/083 049/080 050/072 044/069 041/066 038/064
    00/K    00/U    12/T    34/T    43/W    22/W    22/W
HDN 042/082 047/086 050/084 053/081 052/077 048/073 045/068
    00/K    00/K    00/B    11/B    42/W    21/B    21/B
MLS 044/082 048/087 054/087 056/084 054/078 050/075 048/070
    00/K    00/U    00/B    00/U    31/B    20/B    11/B
4BQ 046/081 052/086 055/086 058/082 055/076 051/074 048/068
    00/U    00/U    00/B    00/U    21/B    10/B    11/B
BHK 042/081 047/088 051/087 055/085 052/079 048/075 045/070
    00/U    00/U    00/B    00/U    11/B    10/B    11/B
SHR 041/082 047/086 050/083 050/079 047/074 044/072 040/067
    00/K    00/U    11/B    12/W    32/W    11/B    12/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings

NWS byz Office Area Forecast Discussion