635
FXUS65 KTFX 280605
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1205 AM MDT Tue Jul 28 2026

.KEY MESSAGES...

 - Remaining hot through the rest of the work week, with the
   hottest day of the upcoming week occurring on Saturday.

 - Winds increase late Saturday and last into Sunday, with the
   strongest winds occurring along the Rocky Mountain Front.

 - Brief reprieve from the heat early next week.

&&

.DISCUSSION...

 - Meteorological Overview:

Upper level ridging will dominate through much of the forecast
period, with the ridge bringing continued hot temperatures to most
locations from Southwest through North Central Montana until
Saturday. By Sunday a potent longwave trough will breakdown the
ridge and bring increasing winds and slightly cooler temperatures to
the Northern Rockies, with temperatures falling below normal into
the day on Monday in wake of a cold front. Monsoonal moisture
lifting up and around the ridge will provide daily chances for
isolated showers and storms; however, most locations will remain dry
over the next week. - Moldan

 - Forecast Confidence & Scenarios:

Return of Extreme Temperatures by Saturday...

While temperatures will remain hot through the remainder of the work
week climate anomaly indicators have honed in on Saturday being the
hottest day of the upcoming week, with values becoming unusual to
very unusual with respect to late July/early August climatology. The
fact that these climate anomaly indicators are suggesting another
period of hot temperatures is remarkable considering that August 1st
is (at most locations) only one day past the climatological peak for
average high temperatures across Southwest through North Central
Montana. The table below represents the potential high temperature
scenarios for select cities across Southwest through North Central
Montana, with the "Low End" scenario being the NBM10Pct (10% chance
that temperatures are lower than the listed value), "Most Likely"
scenario being the NBM50Pct, and the "High End" scenario being the
NBM90Pct (10% chance that temperatures exceed the listed value).

                    Saturday`s High Temperature Scenarios
LOCATION               Low End | Most Likely | High End
Browning                  88   |      93     |     98
Cut Bank                  95   |     100     |    104
Havre                    103   |     108     |    111
Great Falls              102   |     105     |    107
Lewistown                 98   |     101     |    104
Helena                    97   |     100     |    104
White Sulphur Springs     95   |     102     |    101
Bozeman                   98   |      98     |    105
Dillon                    95   |      98     |    100
Ennis                     94   |      98     |    100
West Yellowstone          89   |      93     |     96

Given the presence of regional wildfires across the Northern Rockies
the "High End" scenario will be tough to reach due to decreased
solar insolation from the smoke, with dense smoke having the ability
to hold temperatures back some 5 to 10 degrees.

Strong Winds from Saturday night through Sunday...

Confidence is increasing that a period of strong, nearing high,
winds will impact the Rocky Mountain Front from Saturday night
through the day on Sunday due to the combination of mountain wave
activity (from the late evening hours on Saturday through Sunday
morning) and deep mixing (during the daylight hourS on Sunday). H700
winds per NAEFS analysis are prog`d to reach 40-50kts from Saturday
evening through Sunday morning across the aforementioned area, which
is 2 to nearly 3 standard deviations above normal. The table below
are the NBM5.0 probabilities for wind gusts to exceed 45 mph, 55
mph, and 65 mph for select locations along the Rocky Mountain Front
for the previously mentioned timeframe.

                    Probabilities for Wind Gusts to Exceed
LOCATION               >45 mph |   >55 mph   |  >65 mph
Many Glacier Valley      55%   |     15%     |    <5%
Logan Pass               50%   |     10%     |     0%
St Mary                  80%   |     40%     |    10%
Two Medicine Valley      70%   |     30%     |    10%
East Glacier             75%   |     25%     |    10%
Browning                 70%   |     25%     |     5%
Cut Bank                 75%   |     20%     |     5%
Heart Butte              80%   |     30%     |    20%
Choteau                   5%   |      0%     |     0%
Augusta                  20%   |     <5%     |     0%

Those looking to travel or recreate along the Rocky Mountain Front
should be prepared for strong winds; which could make driving and
hiking difficult, lead to falling trees in the backcountry, and/or
lead to the spread of existing/new wildfires. - Moldan

&&

.AVIATION...
28/06Z TAF Period

Wildfire smoke from the Pacific Northwest will be the primary
concern through the TAF period. Visibilities can drop down to MVFR
at times in the morning due to the smoke across North-Central MT.
Isolated showers and thunderstorms continue into the early morning for
Southwest MT/Central MT. Another round of isolated to scattered
showers and thunderstorms for Southwest MT Tuesday afternoon and
early evening.

For KGTF: Winds will prevail out of the north into the early
morning hours, becoming light and variable through the rest of the
morning. By Tuesday afternoon, winds will prevail more out of the
west. Probabilities for a 15kt crosswind remain low through the
morning (10%), but it increases to 50% by 28/22 through 29/02z.
-Wilson


&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  95  61  94  60 /   0   0   0   0
CTB  91  56  89  55 /   0   0   0   0
HLN  94  59  93  59 /  10   0  10  10
BZN  94  58  92  57 /  20   0  20  10
WYS  88  49  85  47 /  10   0  30  20
DLN  91  55  88  54 /  10   0  20  10
HVR  98  60  95  59 /   0   0   0   0
LWT  93  58  90  57 /  20  20  10  20

&&

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

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