Sidney, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

436
FXUS65 KGGW 111555
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
955 AM MDT Fri Apr 11 2025

.DISCUSSION...

KEY MESSAGES:

* Very warm temperatures and low humidity will prevail across the
  region today before a low pressure system moves in.

* A change in the weather pattern will bring potential for
  accumulating rain this weekend and cooler temperatures.

* Warm and dry conditions resume Monday.

WEATHER PATTERN OVERVIEW:

Synoptic scale model data (GFS and ECMWF ensemble) indicate that
a brief, strong ridge of high pressure will move across northeast
Montana this morning which will move to the east this afternoon.
Temperatures will be well above normal. For information regarding
fire weather, feel free to check out the Fire Weather discussion
below. A dry cold front this afternoon will bring gusty west to NW winds
which will be strongest in the north. The winds will be strong
enough (around 20 mph) to keep the Lake Wind Advisory in effect
for Fort Peck Lake this afternoon and early evening. WSW flow
aloft will begin to bring moisture into the area this evening.
Areas south of the Missouri River could see a few showers tonight,
however, with very dry mid and low level level air, most of this
precipitation will not reach the ground.

SW flow aloft on Saturday will be over the forecast area which
will be ahead of an approaching cooler, open wave low pressure
trough. This will bring increasing moisture into the forecast
area. Chances for a tenth of an inch of precipitation on Saturday
varies from 20-30% along the Canadian and North Dakota border to
60% around Winnett. with the deepest moisture south of the
Missouri River.

Upper trough moves through eastern Montana Saturday night and
Sunday morning. Models differ on timing and location of dry slots
Saturday night. NBM currently has the highest probability of
precipitation in the SE in the evening and in the north after
midnight. Colder air moves in which will allow mixing with snow
in some areas on Sunday. The best chances for accumulating snow
on Sunday will be near Zortman and Opheim where the probability of
one inch of snow is around 30%.

Persistent model runs show NW winds with this storm system around
20 to 25 knots on Sunday, so Lake Wind Advisory conditions are
likely on Sunday.

The upper trough moves east Sunday night ending the chances for
precipitation. A ridge of high pressure moves into Montana on
Tuesday with warm and dry weather.

FORECAST CONFIDENCE & DEVIATIONS:

Went closer to the NBM90 for winds today with higher temperatures
and lower relative humidity. Stayed with the base forecast for the
rest of the forecast.

There is high confidence on precipitation occurring this weekend
with low to moderate confidence specific rainfall amounts through
Sunday night.


&&

.AVIATION...

LAST UPDATED: 1550Z

FLIGHT CAT RANGE: VFR.

DISCUSSION: A strong ridge of high pressure will move through the
area this morning, providing warm and stable conditions for
pilots. A dry cold front this afternoon will bring NW winds with
it. An active storm system will move into the region from the west
tonight with chances for rain beginning either late tonight or
Saturday morning.

SFC WIND: South 5 to 15 knots this morning becoming WNW northwest
at 15 to 25 knots after 18Z, but sooner at KGGW. TFJ



&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 PM MDT this evening for
Dawson/McCone/Prairie/Richland/Wibaux Counties-Fort Peck
Reservation and Daniels/Roosevelt/Sheridan Counties-Northern
Valley and Northern Phillips Counties.

Lake Wind Advisory until 8 PM MDT this evening for Central and
Southeast Phillips-Central and Southern Valley-Garfield-McCone-
Petroleum.

&&

$$

weather.gov/glasgow