992
FXUS65 KTFX 091634
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1034 AM MDT Wed Jul 9 2025

.KEY MESSAGES...

 - Hot, dry, and breezy conditions will occur across all of
   Southwest through North Central Montana today.

 - Winds, with gusts of between 40 to 50 mph, will be strongest
   along the Rock Mountain Front through this evening.

 - Showers and thunderstorms will increase in coverage through
   the late afternoon and evening hours as a Pacific front
   approaches the Northern Rockies, with any shower or storm
   producing gusty and erratic winds.

 - Temperatures cool into the day on Thursday, with a better
   chance for rainfall.

&&

.UPDATE...

A few mid and upper level clouds across North Central Montana this
morning continue to slowly drift off to the east. While these
clouds have slowed the inevitable warm up across the area, expect
temperatures to quickly rise as these clouds move out of the area
and evaporate. Additionally, the threat for gusty winds from
thunderstorms continues to increase even in spite of these clouds,
and I have added gusty wind wording to thunderstorms this
afternoon and evening. Ludwig

&&

.DISCUSSION...
/Issued 510 AM MDT Wed Jul 9 2025/

Upper level ridge over the Northern Rockies will be broken down as a
longwave trough, currently moving over the western seaboard of the
CONUS/Canada, slides east through the day on Thursday. At the
surface a Pacific front, which was moving over the Pacific Northwest
this morning, will move across Southwest through North Central
Montana during the evening hours tonight. Strong warm air advection
ahead of the advancing shortwave and attendant Pacific front will
once again push high temperatures across Southwest through North
Central Montana some 10 to 15 degrees above normal, with highs over
the plains (below 3500 feet in elevation) of Central and North
Central Montana peaking in excess of 95 degrees today. Isolated
showers and thunderstorms through the morning and early afternoon
hours, which will be predominately on the dry side, will become more
widely scattered through the late afternoon and evening hours as the
aforementioned Pacific front approaches. Given high cloud bases and
very dry air in the low to mid-levels (i.e. inverted-V sounding) any
shower and thunderstorm through this evening will be capable of
producing strong and erratic winds on top of the already increasing
westerly surface winds. These breezy and gusty west surface winds
ahead of the Pacific front will be especially strong along the Rocky
Mountain Front and immediate eastern plains out to the I-15 corridor
in Central and North Central Montana, with frequent guest of between
40-50 mph occurring here.

By Thursday morning a potent shortwave rotating through the overall
longwave trough axis will begin to dive southeast from British
Columbia and over the Northern Rockies. This shortwave and a re-
enforcing cold front will help to bring cooler conditions to all of
the Northern Rockies on Thursday, along with scattered to numerous
showers and isolated thunderstorms. Snow levels across Glacier
National Park will fall to as low as 8500feet through Thursday
evening, which could lead to a dusting of snow over the highest
peaks across the park. Surface winds in wake of the re-enforcing
cold front will shift to the northwest and north, with another period
of strong and gusty winds expected through the day on Thursday,
especially in the north-south orientated valleys of Southwest and
Central Montana.

Quasi-zonal to northwest flow through the remainder of the work
week, weekend, and early next week will lead to fluctuating
temperatures and periods of dry and wet conditons. - Moldan


&&

.AVIATION...
09/12Z TAF Period

Isolated showers and thunderstorms through the morning and early
afternoon hours, all of which will produce little to no rainfall,
will become more widely scattered from the late afternoon through
evening hours tonight. Main impact to terminal operations of any
shower or thunderstorm that moves over or near a given terminal
will be gusty and erratic winds. This will be especially true
along and east of a KHLN, to KGTF, to KHVR line where
thunderstorms have a 5-15% chance of producing wind gusts in
excess of 50kts. Otherwise VFR conditions are expected throughout
the 0912/1012 TAF period, with limited mountain obscuration over
the next 24 hours. - Moldan

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

&&

.FIRE WEATHER...

Upper level ridging over the Northern Rockies will undergo a full
breakdown over the next 24-36 hours, with cooler conditions and
better chances for rainfall returning to Southwest through North
Central Montana through the day on Thursday. Prior to these
improving fire weather conditions a hot, dry, and breezy day can be
expected across all fire weather zones today. High temperatures will
once again soar some 10 to 15 degrees above normal, with minimum
relative humidity values generally falling to between 10% to 15%.
Westerly surface winds will be on the increase throughout the day,
most notably along the Rocky Mountain Front and immediate eastern
plains, ahead of an advancing Pacific front.  This Pacific front
will provide the opportunity for generally dry, showers and
thunderstorms which would be capable of producing gusty and erratic
winds. By Thursday a re-enforcing cold front will begin to dive
south from Canada, with a shift to more northerly winds that will
remain breezy and gusty.

With Hot, Dry, and Windy Indices (HDWI) and ERC values remaining
below the 95th Percentile through the ridge breakdown across all
Fire Weather Zones we have held-off on any Fire Weather Highlights;
however, this ridge breakdown will certainly aide in the further
curing of fuels across both the forests and grasslands. Elevated
fire weather conditions will exist through this evening. - Moldan

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  98  59  78  45 /  20  20  20  20
CTB  91  56  66  41 /  20  20  50  10
HLN  94  59  81  47 /  20  30  20  10
BZN  95  52  85  46 /  20  30  20  20
WYS  83  43  77  38 /  20  20  20  20
DLN  90  48  82  45 /  20  30   0  10
HVR 100  58  77  45 /  20  20  30  10
LWT  92  55  77  42 /  20  30  20  30

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM MDT this evening for Cascade County
below 5000ft-Hill County-Northern Blaine County-Western and
Central Chouteau County.

&&

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