Area Forecast Discussion
Issued by NWS Billings, MT
Issued by NWS Billings, MT
801
FXUS65 KBYZ 061148
AFDBYZ
Area Forecast Discussion...Updated
National Weather Service Billings MT
548 AM MDT Sun Sep 6 2026
.KEY MESSAGES...
- Increasing chance for showers and thundersorms this evening into
Monday. Thunderstorms will be capable of producing heavy rain
and gusty winds. Cannot rule out hail with discrete
thunderstorms Today as well.
- Windy conditions are expected Monday into Tuesday (wind gusts of
25 to 50 mph, strongest in south-central MT Monday and eastern
MT Tuesday). This will cause elevated fire weather conditions.
- Drier and warmer conditions are likely during the middle of next
week ahead of another potential weather system next weekend.
&&
.DISCUSSION...
Today through Saturday...
Isolated showers and a few rumbles of thunder are ongoing this
morning, mainly over southeastern Montana. The only concern with
this activity are brief wind gusts and a few lightning strikes.
Otherwise, patchy fog may develop in the lower valleys north and
east of Billings this morning, including locations near the
Dakotas Border.
An upper low continues to dig through the Pacific Northwest
today. Later this afternoon and evening, as this low moves
eastward the left exit region of the trough could bring isolated
to scattered shower and thunderstorm development to south and
central Montana. The Storm Prediction Center has a Marginal Risk
(level 1 out of 5) across much of Montana, for a few strong to
severe thunderstorms. The primary concerns are strong wind gusts,
heavy rainfall, and hail. Capping looks to be a problem though,
with HiRes models depicting a strong enough cap that hinders
convective development. The exception is far southeast Montana
where a surface low will exist and provide a forcing mechanism.
The low continues moving through Idaho this evening,
bringing a shortwave ahead of it. This wave will bring ample
forcing and a better chance of precipitation (up to 70 percent)
to south- central Montana into Monday. Look for showers and weak
thunderstorms overnight, before the chance for precipitation
generally comes to an end through Monday morning. Lingering
activity may still exist over the mountains and foothills west of
Billings as well as along the Dakotas Border.
The aforementioned low pressure system will move northeastward
through Montana on Monday. Isolated shower and thunderstorm
activity looks to accompany this during the day. The threat for
strong to severe thunderstorms will be very low. The main hazard
looks to be the synoptic winds associated with the low pressure
system. At this time, widespread wind gusts in the 20s to 40s mph
are forecast, strongest over the foothills west of Billings. Areas
around Livingston to Big Timber and Harlowton may even see a few
50 mph wind gusts late Monday (50 to 70 percent chance).
Tuesday, windy conditions look to continue across much of the
area, though the strongest winds will shift to be over far eastern
Montana. Again, wind gusts in the 20s to 40s mph are forecast to
be common, strongest to the north and east, with a few 50 mph wind
gusts possible around Baker, Montana (25 to 40 percent chance).
Wednesday into Friday are forecast to be mostly dry days as low
amplitude ridging nudges into the region aloft. By late Friday
into the weekend, the chance of precipitation returns, but
uncertainty remains regarding the upper level weather pattern.
LA/PM
.AVIATION...
12z TAF/Aviation Discussion...A few areas of stratus and fog are
evident on satellite early this morning. One is along the east
slopes of the western foothills including K6SO which could
possibly work into KLVM over the next few hours. The other is over
the lower Musselshell River Valley east of Roundup. Observations
are sparse near this activity but where ceilometers have measured
they show around a 2500-3000ft AGL ceiling. Temp/DP spreads
support at least a slight chance for fog development over the next
few hours from Hysham east along the Yellowstone River to Miles
City and over to Baker, along with other river and stream valleys
east of Billings. Any fog and stratus should dissipate by 15-16z.
Elevated instability will be over the forecast area through the
day today, waiting on decent forcing to unleash it. Weak forcing
over SE Montana continues to spawn weak convection at 12z with
models diminishing this activity by 16z. Stronger forcing will
come tonight as strong PacNW trof pushes into the area. SPC
Convective Outlook has a slight risk of severe storms grazing our
W/NW zones and a marginal risk for much of the rest of the
forecast area for mainly this evening. Do not expect much activity
during the day today, but with that elevated instability its not
out of the question for isolated convection to randomly pop up, so
keep an eye out flying around today. Broader area of showers and
embedded thunderstorms moves north out of Wyoming and across the
forecast area starting around 02z and lasting to around sunrise if
not a bit longer. MVFR to localized IFR conditions in heavy
rainfall is possible with the stronger activity tonight, along
with wind gusts of 30 to 40kts and hail up to an inch in diameter.
Activity should be on a downward trend/lifting north of the area
by sunrise Monday. Chambers
&&
.PRELIMINARY POINT TEMP/POPS...
Tdy Mon Tue Wed Thu Fri Sat
-------------------------------------------------------
BIL 086 061/080 054/075 049/081 053/087 055/079 051/066
1/U 53/W 00/N 00/U 00/U 01/B 43/W
LVM 083 050/071 042/071 040/080 047/084 048/079 044/066
0/U 64/T 10/N 00/U 00/N 12/T 44/W
HDN 089 058/085 050/077 045/082 046/088 049/081 047/068
1/U 43/T 00/N 00/U 00/U 01/U 33/W
MLS 091 065/085 054/075 048/079 051/086 053/079 049/067
2/W 43/W 10/N 00/U 00/U 01/U 42/W
4BQ 093 068/087 054/078 048/081 052/087 054/082 050/071
2/U 52/T 30/U 00/U 00/U 00/U 32/W
BHK 095 063/088 050/077 044/080 047/087 050/081 045/070
3/T 73/N 10/N 10/U 00/U 00/U 42/W
SHR 089 057/083 045/076 042/078 046/085 048/081 045/070
0/U 31/B 00/U 00/U 00/U 00/U 33/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
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