682
FXUS65 KGGW 160825
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
225 AM MDT Thu Oct 16 2025

.DISCUSSION...

KEY MESSAGES:

1) Cool and wet weather will continue at times through tonight,
with 1 to 2 inches of rainfall possible near the MT/ND border.

2) Gusty northwest winds will develop on Friday on the backside of
a departing low pressure system.

3) Upper ridging will develop over the region for the weekend with
drier and milder weather conditions.

WEATHER PATTERN OVERVIEW:

A deep Western U.S. trough and closed low lifting northeast looks
to send significant rounds of rainfall across eastern Montana
today and tonight. While there continues to be variations in the
models and ensemble, NBM continues to support an inch or more of
additional QPF for eastern locations. The latest HREF mean QPF
through tonight is also in the 1.00 to 1.50 inch range east of
Circle, Poplar, and Plentywood. The probability of one inch or
more additional rain today and tonight ending at 12z Friday in
this area is 50-60 percent in the NBM and 50-90 percent in the
HREF with the maximum located near Terry and Glendive. Hydrology
concerns are not expected given the stratiform and gradual
accumulation expected along with dry soils leading into this
event. However, embedded convective elements could lead to
locally heavy rainfall at times. Low clouds over the area will be
below ground level in some areas today with fog expected at times.

On Friday the low will lift to the northeast with showers becoming
more isolated. These showers may become enhanced Friday night with
a new shortwave dropping southeast Friday night. That said, also
look for strengthening northwest winds on the backside of the main
low as it lifts to the northeast. A Lake Wind Advisory for Fort
Peck Lake may be needed on Friday.

Over the weekend, ensembles carve out the next ridge pattern
building across the Pacific Northwest, extending into Montana.
This should result in a warm up in temperatures and drier weather
conditions.

FORECAST CONFIDENCE & DEVIATIONS:

NBM was used this forecast cycle except for small adjustments for
collaboration and consistency. Overall confidence is high on cool
and wet weather today and tonight.


&&

.AVIATION...

LAST UPDATE: Thursday October 16 at 0820Z

FLIGHT CAT RANGE: MVFR - IFR

DISCUSSION: Low pressure will bring rain, steady at times across
area terminals leading to reductions in visibility and associated
ceilings. Rain will be most frequent at KGDV and KSDY and least
frequent at KGGW. Patchy fog is also expected with near saturated
boundary layer conditions with rain as well as higher elevations
with stratus.

Rain will diminish from west to east late tonight and Friday
morning. KGGW will see conditions improve to VFR after 06z tonight
as skies clear over that area. It will be after 12z Friday before
skies clear at the other TAF sites.

WIND: Either light and variable or NE less than 10 knots early,
becoming north around 10 knots this morning and NW this afternoon
at KGGW and this evening at KOLF, KSDY, and KGDV and west late
tonight.


&&

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

$$

weather.gov/glasgow