609
FXUS65 KBYZ 110641
AFDBYZ

Area Forecast Discussion
National Weather Service Billings MT
1241 AM MDT Tue Aug 11 2026

.KEY MESSAGES...

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

- Slight chance of late day thunderstorms in far southeast Montana
  today.

- Cooler with showers and thunderstorms (40-80% chance) across
  the area Wednesday through Friday. Storms may produce heavy
  rain.

- Warmer with a daily chance (20-50%) of thunderstorms this
  weekend.


&&

.DISCUSSION...
Next 7 days (Through next Monday)...

Smoke Impacts: Wildfire smoke will continue to impact our region
for the foreseeable future, keeping skies quite hazy, with reduced
surface visibilities and poor air quality at times.

There is a slight risk of fog developing by sunrise across
portions of Fallon and Carter counties as boundary level moisture
surges overnight along the Dakota/Montana borders. Any fog should
lift by 9 AM.

Conditions will remain warm & mostly dry today as zonal flow
continues over our region on top of a large dome of high pressure
anchored over the Four-Corners region. Low level moisture will
remain elevated in the far east. Once again, the environment
could favor a strong t-storm or two along the Dakota/MT border
late in the day if the midlevel cap breaks (15% chance).
Otherwise, it will be dry with temps in the upper 80s and lower
90s. Winds won`t be strong, but N-NE winds in the afternoon may
see local gusts ~20 mph. This will keep fire weather conditions
elevated, especially in the western half of the CWA where RH
readings will bottom in the lower to mid teens this afternoon.

The entire forecast area begins to turn cooler and more humid on
Wednesday, as heights fall in response to a trough dropping out
of southwest Canada into the Pacific NW. This will induce
stronger and deeper easterly flow advecting higher dewpoints
westward across our CWA, while Pacific and monsoonal moisture move
over the region from the south/southwest. The potential for
shower and t-storms dramatically increases by late Wednesday over
the east and spreads west into the evening.

By Thursday and Friday, ensembles agree PWATs will reach up to
1.25" as far west as Billings. Progs indicate a shortwave tracking
over the region as well. Thus, we expect a period of showers
and embedded t-storms capable of producing heavy rain over the
area. WPC has our area highlighted with a marginal to slight risk
of excessive rain (flooding risks) Thursday. Local burn scars will
be at an elevated risk of seeing flash flooding.

Regarding fire weather...the onset of increased lightning
activity may result in new fire starts, as almost our entire
forecast area has not seen measurable rain yet in August. However,
heavy rain with the storms and higher RH readings will hopefully
mitigate fire starts.

Weekend...Heights begin to rise over our region this weekend in
response to another Pacific low developing off the west coast.
Look for temps warming up by Sunday, and while the chance of dail
thunderstorms continues, we should see less overall coverage of
storms.

Look for temperatures to cool to the 80s Wednesday then 70s
Thursday and Friday. Readings will begin to gradually warm this
weekend, reaching lower to mid 80s by Sunday, and 80s to around 90
for Monday. BT

.AVIATION...

Patchy fog is possible (20% chance) east of KMLS this morning,
including KBHK. This afternoon and evening, isolated showers and
thunderstorms may develop over the east, including near KBHK. The
main threats are gusty, erratic winds up to 50 kts and heavy rain
reducing conditions to MVFR/IFR.

Wildfire smoke continues to impact the region, reducing slant
range visibility and occasionally surface visibility to MVFR.
Surface visibility reductions are most likely over south- central
and western Montana and northern Wyoming. This includes KLVM.
Archer

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Wed     Thu     Fri     Sat     Sun     Mon
-------------------------------------------------------
BIL 093 063/085 061/077 057/074 055/077 055/084 058/087
    0/K 00/K    64/T    97/T    64/T    42/W    31/B
LVM 092 054/087 051/076 048/073 045/077 045/083 048/084
    0/K 01/K    56/T    99/T    86/T    42/T    32/T
HDN 094 060/088 058/081 053/076 050/079 051/086 054/090
    0/K 01/K    75/T    95/T    54/T    42/W    31/B
MLS 093 061/084 058/077 056/075 052/076 053/083 057/088
    0/K 04/W    78/T    96/W    43/W    21/B    21/B
4BQ 093 063/085 060/078 058/077 055/077 055/083 058/087
    0/K 06/T    78/T    +6/T    43/T    42/T    31/B
BHK 091 055/082 052/074 051/074 048/075 048/081 052/086
    2/T 14/K    67/T    99/T    41/E    22/T    22/T
SHR 092 058/086 055/078 052/074 050/075 049/081 051/086
    0/K 04/T    57/T    99/T    78/T    53/T    21/U

&&

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

&&

$$
weather.gov/billings