450
FXUS65 KTFX 071607
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1007 AM MDT Mon Jul 7 2025

.KEY MESSAGES...

 - Temperatures continue to warm through Wednesday, with most
   locations rising into the 90s on Tuesday and Wednesday.

 - Winds increase on Wednesday ahead of Pacific front, with winds
   gusting in excess of 40 mph along the Rocky Mountain Front.

 - A brief cool down occurs on Thursday in wake of a re-enforcing
   cold front, with chances for showers and thunderstorms north
   of the I-90 corridor.

&&

.UPDATE...

With upper level ridging in place across the area, the forecast
remains on track. I have removed any lingering mentions of fog
from the forecast as the main change this morning. Ludwig

&&

.DISCUSSION...
/Issued 458 AM MDT Mon Jul 7 2025/

 - Meteorological Overview:

Broad upper level ridging will build in over the Northern Rockies
through the first half of the work week before being broken down by
a shortwave moving across Western Canada from Wednesday through
Thursday. While predominately dry conditions are expected today and
Tuesday across Southwest through North Central Montana and isolated
(light) rain shower or thunderstorm can`t be ruled out. Any shower
or thunderstorm on Tuesday, particularly across Southwest Montana
(i.e. Dillon Area), would be on the drier side but produce strong
and erratic outflow winds due to very dry air in the low to mid-
levels of the atmosphere. High temperatures will continue to
moderate today across the Northern Rockies with the hottest
temperatures of the work week occurring on Tuesday and Wednesday as
a strong push of warm air is advected north from over the Desert
Southwest/Great Basin. An approaching Pacific front on Wednesday
will bring increasing surface winds, particularly along the Rocky
Mountain Front, and precipitation chances; with continued gusty
winds and showers/storms across all of Southwest through North
Central Montana on Thursday in wake of a re-enforcing cold front
dropping south from Canada. High temperatures on Thursday will cool
significantly from the days prior, with most lower elevations
ranging from the mid-60s (Glacier County) to low 80s (valleys of
Southwest Montana). Quasi-northwest flow to end the work week and
through the weekend will then generally lead to overall dry
conditions and slowly moderating temperatures across the Northern
Rockies. - Moldan

 - Forecast Confidence & Scenarios:

Heat on Tuesday and Wednesday :

Hottest temperatures on both Tuesday and Wednesday will occur over
the plains of Central and North Central Montana, generally for
elevations at or below 3500 feet. NBM probabilities with respect to
temperatures reaching or exceeding 100 degrees have fallen
(slightly, by 5-10%) to generally range from a 5-10% chance for
these elevations on Tuesday, with probabilities remaining nearly the
same (as compared to 24 hours ago) at between a 20-50% chance on
Wednesday.

Gusty Winds on Wednesday and Thursday:

Deep mixing ahead of and behind an advancing Pacific front on
Wednesday will bring gusty west winds to the plains of Central and
North Central Montana and the north-south valleys in Southwest
Montana. Winds will be especially strong along the Rocky Mountain
Front and immediate plains out to Cut Bank, with the latest NBM
probabilities for wind gusts in excess of 40 mph ranging from a 90-
95% chance for areas like Cut Bank, Browning, and East Glacier. On
Thursday a re-enforcing cold front diving south from Canada will
bring another period of strong and gusty winds, this time from the
northwest to north. ECMWF EFIs for the day on on Thursday,
particularly across Central and portions of north Central Montana
(i.e. south of the US Hwy 2 corridor and north of the US Hwy 12
corridor) range from 0.6 to 0.8 with NBM probabilities for wind gusts
of 40+ mph generally range between a 40-70% chance. - Moldan

&&

.AVIATION...
07/12Z TAF Period

Light rain showers continue to slowly exit to the east of the KHVR
and KLWT terminals, with the main impact from any shower being
gusty and erratic winds and periods of broken mid-level CIGS.
Otherwise upper level ridging will continue to build in over the
Northern Rockies over the next 24 hours, with VFR conditions
prevailing. Mountain obscuration is not expected during the
0712/0812 TAF period. - Moldan

Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  85  54  96  61 /  10   0   0   0
CTB  80  49  90  58 /  10   0   0   0
HLN  87  55  94  58 /   0   0   0  10
BZN  87  51  94  55 /   0   0   0  10
WYS  78  37  83  38 /   0   0   0  20
DLN  85  49  89  50 /   0   0   0  20
HVR  84  54  96  61 /  10   0   0  10
LWT  79  52  89  57 /  10  10   0  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$
http://www.weather.gov/greatfalls