782
FXUS65 KBYZ 091834
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
1234 PM MDT Sun Aug 9 2026

.KEY MESSAGES...

- An isolated thunderstorm possible near the Dakotas border late
  this afternoon and early evening.

- Wildfire smoke keeps skies hazy for the foreseeable future, and
  will occasionally reduce air quality. For the latest air
  quality, visit airnow.gov.

- Increasing chance of thunderstorms in southeast Montana Tuesday
  and Wednesday.

- Cooler with a greater chance (25-60%) of showers and
  thunderstorms across the area to end the week. Thunderstorms may
  produce heavy rain.

&&

.DISCUSSION...

Through next Sunday...

Morning light showers/sprinkles have exited southeast MT and dry
conditions exist across the forecast area. Most of the area will
remain dry today, but cannot rule out a t-storm or two near the
Dakotas border in the late afternoon and early evening, though
admittedly the greater chance of this is in the Dakotas.
Mesoanalysis shows a 850mb dewpt tongue of >+10C over southeast
MT, so instability will build with daytime heating. The question
is whether or not the air mass remains capped. Low confidence, but
the mention of isolated TS is warranted. Mixed NW-N winds will
become somewhat breezy over the western two-thirds of our forecast
area this afternoon, which along with RHs in the low-mid teens
will keep fire weather conditions elevated through the day. Be
careful to not spark a fire. Wildfire smoke will continue to
advect from the west for the foreseeable future, keeping skies
quite hazy, with occasionally reduced surface visibilities and air
quality. Unfortunately there is no end in sight for the smoke
issues.

Low level easterly winds will continue to push up pwats the next
couple of days, especially over the east. There is a low chance
(10-20%) of late day t-storms in the far east each of the next two
days. Forcing will be weak and it is also possible that the air
mass will remain too capped for storms to develop. Smoke cover
will also be a hindrance.

Pwats eventually become 1-2 standard deviations above normal by
midweek. Along with falling heights from a trof dropping out of
southwest Canada, this will lead to increasing shower and
thunderstorm potential from Wednesday through the end of the week.
Ensembles show pwats increasing to greater than an inch close to
the western foothills by Wednesday night. Lightning from t-storm
activity may be problematic with regard to fire potential after
the current stretch of hot & dry days (most of our cwa has not
seen measurable rain yet this month, and won`t for the next few
days), but the storms will no doubt be wet and could produce heavy
rain as well as gusty surface winds. Timing of waves and periods
of ascent/subsidence into late week are difficult to determine
now, but generally speaking the atmospheric moisture will remain
elevated and the risk of wet t-storms will continue daily through
the weekend.

Temperatures will transition from above normal early in the week
to below normal at the end. Look for upper 80s to mid 90s Monday
and Tuesday, followed by 80s Wednesday, then 70s to lower 80s
Thursday through the weekend.

As a side note, there is a tropical wave near 10N 140W that is
likely to become a named storm southeast of Hawaii over the next 7
days. Models at this time have varying solutions with the
evolution of this wave, but it may eventually impact the longwave
pattern over the central and eastern Pacific during the latter
part of August, and is worth watching. We are in the time of year
when storms in the tropical Pacific can alter large scale weather
patterns.

JKL

.AVIATION...

Wildfire smoke will continue to impact the region today, reducing
slant range visibility and occasionally surface visibility to
MVFR (generally 4SM or 5SM). Surface visibility reductions are
most likely over south-central and western Montana and northern
Wyoming. Otherwise, there is a low chance (15 percent) of showers
and thunderstorms developing over far eastern Montana late this
afternoon and evening before quickly moving east into North Dakota
and South Dakota. This activity could impact KBHK and K97M, but
confidence is low. LA

&&

.PRELIMINARY POINT TEMP/POPS...

    Mon     Tue     Wed     Thu     Fri     Sat     Sun
-----------------------------------------------------------
BIL 062/093 062/092 061/084 060/076 057/073 056/075 056/080
    00/K    00/U    01/B    55/T    75/W    54/T    43/W
LVM 051/093 051/091 050/085 051/076 048/074 047/076 047/079
    00/K    00/U    01/B    45/T    76/T    66/T    54/T
HDN 057/094 059/092 058/086 057/078 054/075 052/077 052/082
    00/K    00/U    01/B    56/T    75/T    54/T    43/T
MLS 060/092 062/092 061/083 057/076 055/075 053/076 054/081
    00/K    00/U    14/T    57/T    76/T    33/T    43/T
4BQ 060/094 062/092 062/084 059/075 056/074 055/075 055/080
    00/K    00/U    15/T    78/T    86/T    64/T    53/T
BHK 057/089 057/090 055/081 051/074 050/073 049/075 049/079
    21/K    02/T    25/T    66/T    77/T    53/W    43/T
SHR 057/094 057/092 055/086 055/076 052/072 051/073 050/078
    00/K    00/U    13/T    58/T    88/T    77/T    54/T

&&

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

&&

$$
weather.gov/billings