Sidney, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

929
FXUS65 KGGW 241859
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
1259 PM MDT Fri Jul 24 2026

.KEY MESSAGES...

- Temperatures in the 90s to low 100s for highs are expected this
  weekend into most of next week. An Extreme Heat Warning is in
  effect through Sunday...for now.

- Dry conditions most of the time but there could be an isolated
  thunderstorm in the evening tonight and tomorrow evening.

- Mainly dry and breezy conditions today. A Red Flag Warning is in
  effect today and tomorrow afternoon and evening for various
  locations.




&&

.DISCUSSION...

WEATHER PATTERN OVERVIEW:
An upper ridge over the western states is bringing the heat back
to the area. The base NBM has 100 degrees forecast for at least a
few locations through Wednesday. Today, a shortwave trough is
expected to bring an isolated storm to the southwest and
northeast. The main concern is gusty outflow winds. A shortwave
trough is expected to move into the southwest part of the area
tomorrow afternoon and evening, and the main concern is gusty
winds again. The base HREF has gusts up to around 60 mph, and the
maximum HREF has gusts up to 80 mph. There is a low probability of
80 mph occurring tomorrow. The main concern for fire starts is low
humidity and strong winds for today, and lightning strikes
tomorrow. There is a Red Flag Warning out for fire zones 122, 135,
134, 137, and 136 for today, and fire zones 134, 135, 136, and 137
for tomorrow afternoon and evening.

Abundant smoke from the Pacific NW fires is over the area, and
mainly reducing visibility from 1 KM to 6 KM above the ground.
There is a chance of this haze and smoke affecting sensitive
groups near the ground for smoke that does reach the ground.

West winds are strong enough to support the Lake Wind Advisory
from now through 6 PM this evening.

There is an Extreme Heat Warning in effect for this strong ridge
that has aided in bringing temperatures up. These warm conditions
during the day and poor temperature recoveries at night
(temperatures staying above 65 degrees) will make it important to
have efficient cooling systems in place. These poor temperature
recoveries are in the forecast in the southern half of the area
through Thursday.

FORECAST CONFIDENCE & DEVIATIONS:
The only deviation was to add a slight chance of PoPs to various
parts of the area through tomorrow evening.

There is high confidence in the heat products that are in effect
through Sunday evening. There is moderate confidence in heat
products being needed again during the week.

There is low to moderate confidence in severe wind gusts occurring
in the northeast this evening and in the west tomorrow afternoon
and evening.

There is high confidence in smoke moving through the area from 1
kilometer and 6 kilometer above the ground through tomorrow
morning, and moderate confidence in surface haze and smoke
occurring.

There is high confidence in the Red Flag Warning verifying today,
and moderate confidence for tomorrow. This confidence is the same
for the Lake Wind Advisory in effect for today.

&&

.AVIATION...
UPDATE TIME: 1830Z

FLIGHT CATEGORY: Mostly VFR. MVFR in isolated thunderstorms, haze,
ans smoke.

SYNOPSIS: An upper ridge is over the area. The main concern at TAF
sites through 20Z tomorrow is haze and smoke. There is some
indication this will be near the ground today, but most of it is
lofted from 2 KM to 6 KM off the surface through about 03Z. Then
another round is expected to affect the area from about 03Z
through about 12Z Saturday. There is moderate confidence to high
confidence of visibilities reaching down to 6 miles, and low
confidence in visibility lower than that. The next concern is
isolated thunderstorms tomorrow evening from 22Z Saturday to 04Z
Saturday for KGGW.

DENSITY ALTITUDE: Issues are expected at times with the heat
today through Sunday at the terminals as temperatures hang around
the 100 degree mark.

WINDS: Northwest at 10 to 20 knots with gusts to 28 knots,
decreasing to light and variable after 03Z.

&&

.FIRE WEATHER...

Upper level ridge moves east across the region today and may
topple over after Sunday. Highs will be in the 80s initially with
a chance for showers mid-day today. Outside of these isolated
showers no wetting rains are expected through the work week. Then,
expect a slow warm up back to near 100s Friday through the
weekend.



&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM MDT this evening for
Dawson/McCone/Prairie/Richland/Wibaux Counties-Northern Valley
and Northern Phillips Counties-Southern Petroleum and Southern
Garfield Counties-The Little Rockies-The Lower Missouri River
Breaks including the Charles M Russell National Wildlife Refuge.

Red Flag Warning from 4 PM to 10 PM MDT Saturday for Northern
Valley and Northern Phillips Counties-Southern Petroleum and
Southern Garfield Counties-The Little Rockies-The Lower Missouri
River Breaks including the Charles M Russell National Wildlife
Refuge.

Lake Wind Advisory until 6 PM MDT this evening for Central and
Southeast Phillips-Central and Southern Valley-Garfield-McCone-
Petroleum.

Extreme Heat Warning until 10 PM MDT Sunday for Central and
Southeast Phillips-Central and Southern Valley-Daniels-Dawson-
Eastern Roosevelt-Garfield-McCone-Northern Phillips-Northern
Valley-Petroleum-Prairie-Richland-Sheridan-Southwest Phillips-
Western Roosevelt-Wibaux.

&&

$$

weather.gov/glasgow