635
FXUS65 KGGW 092041
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
241 PM MDT Sun Jun 9 2024

.DISCUSSION...

KEY MESSAGES:

- Numerous rain showers and isolated strong thunderstorms will
  arrive from the southwest after 9 PM this evening and linger
  through Monday afternoon.

- With elevated wind speeds and gusts with the passing cold front,
  a Lake Wind Advisory is out through 9 PM Monday.

- A general warming trend to above-normal temperatures is expected
  through the remainder of the forecast period.

WEATHER PATTERN OVERVIEW:
A shortwave trough and associated cold front will make their way
through northeast MT. This will bring rain showers to the area;
there is also moderate (50 percent) confidence of isolated strong
thunderstorms moving through any one location between midnight and
noon Monday. Isolated thunderstorms are expected in the afternoon
Monday after the frontal passage. For rainfall amounts, there is
moderate to high (40 to 60 percent) confidence of rainfall
reaching at least a quarter of an inch between 6 PM tonight
through 6 PM Monday.

Another shortwave trough is expected to move through overnight
Tuesday into Wednesday morning, but little to no rainfall
accumulation is expected with this disturbance.

Shortwave ridging will build in for Wednesday through early
Friday ahead of the next disturbance. The GFS is hinting at a
shortwave trough moving through the region late Friday, but the
ECMWF is not hinting at a shortwave trough moving through at all.
In other words, there is low (30 percent) confidence in the
timing, location, and simply the existence of a shortwave trough
bringing thunderstorms to the area Friday night.


FORECAST CONFIDENCE and DEVIATIONS:
There is moderate to high confidence in rainfall amounts, and high
confidence in timing of showers and thunderstorms through Monday.
There is low to moderate confidence in fire weather conditions
occurring in the southwest portion of the CWA on Thursday. There
is low confidence in timing and location of thunderstorms on
Friday.

-Zanker/Stoinskers



&&

.AVIATION...

LAST UPDATE: 2030Z

FLIGHT CAT RANGE: VFR, then MVFR/IFR after 12Z Monday.

DISCUSSION: High clouds will be over the area through 06Z, and
then scattered showers and thunderstorms will move in from the
southwest. This activity is associated with a shortwave trough
that will move through tonight. There is moderate to high (50 to
60 percent) confidence of showers and thunderstorms moving through
between 12Z and 21Z Monday. Ceilings are expected to lower to
MVFR, with moderate (50 percent) confidence of scattered IFR
conditions occurring in this same time period.

WIND: East at 12 to 20 knots with gusts to 25 knots, becoming
west at 15 to 20 knots after 17Z Monday. Gusty and erratic winds
may occur in the vicinity of thunderstorms.



&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 9 PM MDT Monday for Central and
Southeast Phillips-Central and Southern Valley-Garfield-McCone-
Petroleum.

&&

$$

weather.gov/glasgow