094
FXUS65 KGGW 171901
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
101 PM MDT Mon Aug 17 2026

.KEY MESSAGES...

- A few scattered strong to severe thunderstorms are part of the
  story this evening. Another chance for showers and storms is
  expected tomorrow evening, and then another in the north is
  possible on Wednesday.

- Temperatures look to warm up to near to above normal by the
  middle of the week as highs push back into the mid and upper
  80s.




&&

.DISCUSSION...

WEATHER PATTERN OVERVIEW:
There are some scattered showers moving across the north
currently. The models have some disagreement about storm location
and intensity, but the main possibilities are these. An isolated
strong to severe storm may occur with the ongoing activity in a
few hours from now, a strong storm may start in eastern Alberta
and move into the area by late afternoon, showers in the north
will slowly move south and remain below severe limits, or the
boundary moving southward and the higher terrain will work
together to initiate a strong storm across the south. The best
chance is from 3pm until 10pm. CAPE/Shear profiles in the
presence of steep low level lapse rates and wide afternoon dew
point depressions paint a scenario depicting isolated severe
storms with wind gusts to 60 mph. This is shown well in the HREF
ensemble guidance and high resolution model solutions.

The next shortwave trough will track through the region on Tuesday
evening into Wednesday for additional opportunities for
convection. Ensembles then show height rises over NE Montana as
the U.S. Western CONUS upper level ridge amplifies and becomes
more pronounced. This should push daytime high temperatures for
the second half of the week back toward near or above normal.

FORECAST CONFIDENCE & DEVIATIONS:
The main deviation was to PoPs to fill in the splotchy gaps in the
NBM through tomorrow evening.

There is moderate confidence in storm location and strength
through tomorrow evening.

There is low to moderate confidence in showers and storms
occurring in the northern one third of the area on Wednesday
afternoon.

There is high confidence in mainly dry weather for Thursday and
Friday.

There is low confidence in the late week ridge on when it will
break down.

&&

.AVIATION...
LAST UPDATE: Monday August 17 at 1830Z.

FLIGHT CAT RANGE: VFR, MVFR in thunderstorms.

DISCUSSION: A shortwave trough will provide the necessary support
for scattered showers and thunderstorms today between 21Z and
04Z. A few storms may be severe with wind being the main concern.
There is low to moderate confidence of scattered showers at times
overnight, and then again after 21Z Tuesday to bring slight
reductions in visibility (remaining above 5 miles).

WINDS: Northwest at 6 to 12 knots becoming light and variable
after 00Z. Look for gusty and shifting winds near storms. A few
storms may produce severe wind gusts to 60 mph.


&&

.GGW WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

weather.gov/glasgow