Dillon, Montana Weather Forecast Discussion

629
FXUS65 KTFX 250549
AFDTFX
Area Forecast Discussion
National Weather Service Great Falls MT
1149 PM MDT Wed Sep 24 2025
Aviation Section Updated.
.KEY MESSAGES...
- Afternoon high temperatures will soar as high as 15 to 20
  degrees above average through Thursday.
- Periods of breezy to windy conditions are expected
  through Saturday, especially along the Rocky Mountain Front.
- Temperatures cool slightly on Friday and then rebound once
  again early next week.
- Scattered shower and thunderstorm activity returns by Monday.
&&
.UPDATE...
/Issued 800 PM MDT Wed Sep 24 2025/
Tonight it will be dry and cool across North-central, Central,
and Southwestern Montana. For the update maximum relative humidity
was decreased across North-central, Central, and Southwestern
Montana to better reflect current observations and trends.
Overnight lows across North-central Montana were slightly
decreased to reflect the latest model guidance. The rest of the
forecast is on track. -IG
&&
.DISCUSSION...
/Issued 800 PM MDT Wed Sep 24 2025/
- Meteorological Overview:
Strong ridging aloft will maintain late summer/early autumn heat
over the Northern Rockies for the next 24 hours before a fast
moving Pacific trough brings a brief cool down on Friday. Other
than increased mid- to high level cloudiness and the
aforementioned cooler temperatures Thursday night into Friday, the
primary concern will be very warm, dry, and breezy to windy
conditions, especially on Thursday when southwesterly winds
increase in response to the approaching trough and afternoon
temperatures peak well into the 80s.
The ridge aloft rebuilds over the weekend, despite continued
elevated westerly flow aloft. The stronger winds aloft will relax
after Saturday, but not before mountain wave activity brings a
period of 40 to 60 mph winds along the Rocky Mountain Front Friday
night into early Saturday.
Southwesterly flow aloft develops over the Northern Rockies by
Monday in response to a trough moving into the Pacific Northwest.
This will result in increased shower and thunderstorm activity
while temperatures remain above average through mid- week. - RCG
- Forecast Confidence & Scenarios:
Very warm, dry, and or breezy to windy conditions through
Saturday...
Lower elevation high temperatures warming well into the 80s and
increased westerly breezes will be the primary concern for the
next couple of days. The driest and windiest conditions are
expected along the Rocky Mountain Front and the adjacent high
plains west of I15 on Thursday. These areas will see minimum
relative humidity values falling into the teens while winds gust
over 30 mph at times. Despite the windy and dry conditions, energy
release component values well below the 90th percentile are
expected to preclude widespread elevated fire weather concerns.
The windier conditions expand to include most of central and
north- central MT on Friday with probabilities for gusts over 35
mph increasing to the 40 to 60% range. The elevated fire risk
should be on the low side on Friday given the strongest winds
looking to occur earlier in the day and afternoon temperatures
cooling 10 to 15 degrees cooler from Thursday`s highs. Mountain
wave activity will bring more windy conditions to the Rocky
Mountain Front and adjacent high plains Friday night into early
Saturday with areas along and west of the highway 89 corridor
currently having a greater than 50% chance for 50 mph wind gusts.
Increased shower and thunderstorm activity Monday through next
Wednesday...
A more active southwesterly flow aloft will bring increased
shower and thunderstorm activity early next week. Areas along the
Continental Divide and Southwest Montana should see the most
rainfall where probabilities for totals over a quarter inch are
running between 50 and 70% for the 72 hour period ending next
Thursday at 6 am. The general unsettled conditions are expected to
continue into the second half of next week. - RCG
&&
.AVIATION...
25/06Z TAF Period
Light northerly winds behind a weak cold front will gradually
dissipate over the course of the overnight. Otherwise, expect VFR
conditions through the next 24 hours with the light winds, though
winds will begin to increase at KEKS after 0z tomorrow as a
stronger cold front approaches. Ludwig
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF  46  86  51  75 /   0   0   0   0
CTB  39  84  46  69 /   0   0   0   0
HLN  49  84  50  74 /   0   0   0   0
BZN  44  83  44  74 /   0   0   0   0
WYS  28  71  33  69 /   0   0   0   0
DLN  40  79  42  74 /   0   0   0   0
HVR  43  83  48  73 /   0   0   0   0
LWT  48  84  51  72 /   0   0   0   0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls

NWS TFX Office Area Forecast Discussion