621
FXUS65 KBYZ 312301
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
501 PM MDT Mon Aug 31 2026

.KEY MESSAGES...

- Average temperatures through Tuesday; followed by hot in the
  east and cool in the west.

- Daily chances for showers and thunderstorms starting Tuesday.
  Strong winds may accompany the stronger storms.

- Elevated fire weather Wednesday and Thursday.

- Considerable uncertainty in the forecast later this week. Stay
  tuned as changes are likely.

&&

.DISCUSSION...
Through the Weekend...

After the upper level low from the weekend moves into MB/ON later
today we will be transitioning into a new pattern for most of the
work week. A blocking pattern over the Northern Pacific will
result in a strong upper level low situated just off the coast of
the PNW which will keep SW flow over the western parts of the CWA
for much of the week. There will then be an area of relative high
pressure over much of the central and eastern CONUS keeping our
eastern zones mostly under the influence of that ridge. We will be
in the "battle zone" between these features until the block
potentially breaks down late week.

With this southwesterly flow, we will see several shortwaves move
through the area bringing repeated chances for showers and
storms. The first of which should arrive Tuesday afternoon bringing
a chance for isolated to scattered showers and storms across the
region, mostly in the mountains. Better chances of showers come
Wednesday with a slightly stronger vort max with likely PoPs
forecast in the mountains. None of the showers and storms will be
efficient rainfall producers due to the lack of moisture. PWATs
Tuesday do not even touch 1" on the 90th percentile while the mean
sits around 0.5" of the NBM with Wednesday values only a tenth or
two higher. In terms of severe, the only concern I see as of now
would be strong wind gusts associated with downburst activity /
collapsing showers and storms.

Temperatures will return to normal today and tomorrow with
widespread highs in the upper 70s and low 80s. Following this
there may be a notable difference between the highs in our eastern
plains versus the foothills in the west as the two aforementioned
regimes jockey for dominance. Places like Baker and Miles City may
see highs 10F above average into the 90s while Livingston keeps
temps a touch below average in the 70s. Winds will be a little
breezy Wednesday and Thursday with the advancing shortwaves but
models have backed off with this morning`s runs to what appear to
be more reasonable values. Widespread gusts in the the 20s mph are
forecast both days with slightly higher (30s mph with isolated up
to 40 mph) in the gap areas of the south-centeral Montana
foothills. These conditions combined with Min RH values in the
teens to low 20s will result in elevated fire weather concerns
both Wednesday and Thursday, esepcailly low elevations west of
Billings. Locations in the higher terrain recently received 0.5-1"
of precip and thus fire concerns decrease notably with elevation.

All weather elements this weekend still have several question
marks around it. It looks like the blocking pattern will start to
break down a bit which could result in a progressive pattern
emerging to kick off meteorological fall. The GFS however, is also
showing the remnants of a strong hurricane getting ingested by
the southwesterly monsoonal flow which could bring very wet
conditions to our area. Or there is still a slight chance that the
block could maintain its position a little longer and/or the
tropical system could not develop / miss the track entirely and
then we just remain under the ridge. Those with interests in this
weekend`s weather should frequently check back as the forecast
will likely chance several more times before the end of the work
week. WMR

.AVIATION...

00z Aviation Discussion...Breezy conditions late this afternoon
over SE Montana will diminish heading toward sunset this evening,
with mostly clear skies and light winds overnight. A disturbance
moving in from the south will bring increasing clouds (ceilings
12-20kft AGL) from south to north around sunrise along with a
chance of showers to the southern mountains. By late morning
southerly winds will increase with gusts in the 20-30 mph range
common Tuesday afternoon across the forecast area. Showers will
become possible in the foothills by 16-18z, with isolated
thunderstorms possible in the afternoon, mainly near the higher
terrain. At this time the atmosphere looks too dry below 10kft
AGL to support precipitation making it to the ground over the
plains, but will need to be alert for localized gusty winds and
low level turbulence near areas of virga tomorrow afternoon.
Chambers

&&

.PRELIMINARY POINT TEMP/POPS...

    Tue     Wed     Thu     Fri     Sat     Sun     Mon
-----------------------------------------------------------
BIL 053/080 057/087 058/086 056/087 057/083 058/079 057/080
    02/E    11/U    10/U    00/U    10/U    23/W    32/W
LVM 045/082 048/080 045/079 045/081 047/080 047/076 046/077
    02/W    31/N    00/N    00/U    11/U    23/T    43/T
HDN 050/082 052/090 052/090 050/091 052/086 055/083 054/084
    02/W    00/U    10/U    00/U    00/U    12/W    31/B
MLS 050/084 057/089 057/089 057/091 059/085 060/082 058/083
    02/E    10/U    20/U    00/U    00/U    34/W    31/B
4BQ 054/083 056/091 058/090 059/093 061/087 061/084 059/085
    02/W    20/B    00/U    00/U    00/U    23/T    31/B
BHK 046/083 051/090 055/090 057/094 059/090 057/085 054/085
    02/W    30/U    20/U    00/U    00/U    23/T    41/B
SHR 049/079 049/087 050/087 051/091 054/085 054/081 052/082
    02/T    00/U    00/U    00/U    00/U    22/T    21/B

&&

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

&&

$$
weather.gov/billings