Larslan, Montana Weather Forecast Discussion

002
FXUS65 KGGW 150308
AFDGGW
Area Forecast Discussion
National Weather Service Glasgow MT
908 PM MDT Sun Sep 14 2025
.DISCUSSION...
0745 PM UPDATE:
A few minor changes wer made to PoPs, Sky and Wind to bring the
next 24 hours into a hourly state for the TAFs. Limited changes
were observed. Main among these is that there appears to be some
patchy fog that will make it down into Plentywood and Poplar
near river valley bottoms. GAH
KEY MESSAGES:
1) Upper trough pattern will keep isolated to widely scattered
thunderstorms at times over the region into Tuesday.
2) Drier weather conditions are expected for the second half of
the week with seasonable temperatures continuing.
WEATHER PATTERN OVERVIEW:
A broad upper trough pattern in place will keep isolated to widely
scattered thunderstorms in the forecast at times through Tuesday.
Wetting rains are possible with the steadiest storms, but guidance
has backed off on QPF in recent trends.
Drier weather overall is expected for the second half of the week
with the overall trough having shifted east. That said, some model
guidance keeps low pressure in proximity to keep shower chances
going in the eastern zones. Regardless, temperatures are expected
to remain near seasonable levels this week.
FORECAST CONFIDENCE & DEVIATIONS:
NBM was used for the most part with subtle fixes for consistency
and collaboration. Confidence is high on an active pattern
continuing early this week with seasonable temperatures in place.
Confidence is a bit lower for the second half of the week. The
trough shifting east should result in drier conditions, but some
ensemble spread remains.
RJM
&&
.AVIATION...
LAST UPDATE: 0300Z
FLIGHT CAT RANGE: VFR - Airport Shutdown.
DISCUSSION: A FOG line has set up along the ND/MT border and far
northeast Montana. It is now expected to impact KPWD and KPO1
along with KOLF chances now rising to roughly 50% to 70%. If KOLF
is impacted it will likely reach to airport shutdown for an hour
or two.
KSDY chances have increased slightly as well to about 30-50%, but
with no METARs and a thick cirrus deck overhead it will be very
difficult to determine exactly if let alone when it is being
impacted. If KSDY is impacted ceilings will likely be the main
control with IFR levels around 500 - 900 ft.
Best guestimate at total timing for both terminals is around 12
to 15Z.
WIND: Light and variable overnight. Turning W at 5 to 10 kts on
Monday after sunrise.
EQUIPMENT: NOTAM comms issues with the KSDY observation remain.
AMD NOT SKED will remain in place until METARs are available.
GAH
&&
.GGW WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
weather.gov/glasgow

NWS GGW Office Area Forecast Discussion