880
FXUS65 KGGW 090817
AFDGGW

Area Forecast Discussion
National Weather Service Glasgow MT
217 AM MDT Wed Jul 9 2025

.DISCUSSION...

KEY MESSAGES:
1) Hot July conditions will continue with high temperatures in
the 100s today (Wednesday). A Heat Advisory is in effect,
highlighting the risk for heat related illnesses.

2) Isolated to scattered showers/thunderstorms are expected with
a cold front late this afternoon. Lightning over dry fuels could
lead to some new starts and downdrafts gusts from collapsing
cells could be borderline severe, fanning new flames. Therefore a
Red Flag is also up for this afternoon and evening.

3) Strong winds may generate conditions for a Lake Wind Thursday
afternoon.


WEATHER PATTERN OVERVIEW:
A ridge will shift more over the northern High Plains mid day and
then collapse eastward int eh late afternoon, setting up
favorable conditions for high temperatures to climb above 100.
Thankfully, with such a dry atmosphere, the heat index will
actually be lower than the actual temperature. But hot is still
hot, and the Heat Risk guidance suggests that major heat illness
impacts are possible across most northeast Montana locations for
those not taking necessary precautions. The previous Heat Advisory
that was issued this morning has been updated this afternoon to
include all of our forecast zones.

The partial collapse of the ridge will bring some isolated to
scattered high based thunderstorms during the afternoon through
evening hours across the west, but models continue to show very
little if any rain resulting from them, which raises concerns for
dry lightning. Widespread steady wind speeds will be 10 to 15 mph,
so fire weather concerns would only focus on wind potential from
sudden and short-leved downdraft wind gusts late in the day and
into the evening from any collapsing cells.

Relief, in the form of cooler air is expected Thursday and Friday.
FORECAST CONFIDENCE & DEVIATIONS:
There is high confidence of temperatures reaching the 90s to near
100 for many locations by Wednesday.

Dry thunderstorms with gusty to near severe wind gusts late
Wednesday afternoon and early evening is average/moderate
confidence.

Deviations included increased wind speeds Thursday afternoon.


&&

.AVIATION...

LAST UPDATED: 0830Z

FLIGHT CAT RANGE: VFR.

LLWS: Chances for low level wind shear should exit the terminals
around 12Z.

DISCUSSION: A few high to mid clouds moving in this morning. There
is a 10 to 20% chance for thunderstorms after 06Z for all the
terminals tonight.

WINDS: SE to E at 5 to 10 kts early this morning. Becoming W to NW
around sunrise through the day. Then light and variable this
evening through tonight. Gusty erratic winds could happen near
any thunderstorms tonight.

GAH


&&

.GGW WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 10 AM this morning to 9 PM MDT this evening
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.

Red Flag Warning from 2 PM this afternoon to 4 AM MDT Thursday
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.


&&

$$

weather.gov/glasgow