957
FXUS65 KTFX 051752
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1152 AM MDT Tue May 5 2026

Aviation Section Updated.

.KEY MESSAGES...

 - Another cool and cloudy day today with isolated rain or snow
   showers.

 - A hard freeze is likely tonight as skies clear with light winds by
   Wednesday morning.

 - Warmer temperatures Wednesday through the weekend with chances for
   showers and a few thunderstorms, mainly Thursday and Saturday.

&&

.UPDATE...
/Issued 654 AM MDT Tue May 5 2026/

Weak forcing within the cyclonic flow aloft is resulting in
pockets of light snow this morning across the region. The only
update this morning was to increase mention of light snow through
the morning before additional showers develop this afternoon. -AM

&&

.DISCUSSION...
/Issued 654 AM MDT Tue May 5 2026/

 - Meteorological Overview:

Today through Thursday...Cyclonic, northwest flow aloft will help to
maintain scattered shower and isolated thunderstorm chances across
Southwest through North Central Montana through the evening hours
tonight, especially over the higher terrain and in northerly upslope
areas. High temperatures today will once again be well below normal,
with most locations running 10 to 15 degrees below normal.
Transient ridging begins to slide east over the Northern Rockies
during the overnight hours, with surface high pressure drifting
south and east towards the Central Rockies. Light winds and
clearing skies over this timeframe (tonight) will allow
temperatures to cool efficiently, with most locations falling into
the low to mid-20s, with the exception of the cold prone valleys
of Southwest Montana where the teens will be possible. Overall dry
conditions with moderating temperatures are expected on Wednesday
as the transient ridge axis moves overhead; however,
precipitation chance will be on the increase Wednesday night as a
fast moving shortwave dives southeast from British Columbia and
over the Northern Rockies through the day on Thursday. This
shortwave will support numerous showers and scattered
thunderstorms across Southwest through North Central Montana
during the day on Thursday.

Friday through next Tuesday...Ensemble clusters are in good
agreement with upper level ridging over the Eastern Pacific shifting
east and over the Northern Rockies through the day on Friday before
a fast moving shortwave dives southeast from the Pacific
Northwest/British Columbia and flattens the ridge over the Northern
Rockies (Friday night through the day on Saturday). Upper level
ridging quickly builds back in over the Eastern Pacific from
Saturday night and through the day on Sunday, with this ridge
continuing to build east over the Northern Rockies and amplifying
further through the first half of the upcoming work week. This
pattern will promote moderating temperatures on Friday following
Thursday`s cool and wet conditions, but this moderation will be
short-lived as temperatures cool back to near or slightly below
normal on Saturday. Along with the cool down on Saturday another
opportunity for widespread precipitation will be possible,
especially across Southwest and Central Montana. Temperatures warm
well above normal then for the second half of the weekend and
beginning of the upcoming work week. - Moldan

 - Forecast Confidence & Scenarios:

A hard freeze (min temps 28F or less) is expected (>80% probability)
at most locations across north-central and southwest MT tonight.
This is within the typical climatological window for our area but
those with more sensitive vegetation may need to take protective
steps. A few daily temperatures records may also be challenged
tonight with forecast minimum temps at or below daily records at
Great Falls (26F in 2020), Havre (24F in 1967) and Lewistown (21F in
1942). Hoenisch

&&

.AVIATION...
05/18Z TAF Period

VFR conditions will prevail at all terminals except for the KGTF
and KCTB terminals during this TAF Period. For the first 6 hours
of this TAF Period there will be low ceilings at all terminals
(VFR for all but the KGTF and KCTB terminals). At the KLWT, KGTF,
KHLN, KBZN, and KEKS terminals there is a 10 - 20% chance for
rain/snow showers between now and 06/02Z. Any heavy snow/rain
shower will briefly reduce visibility to MVFR-levels. There will
be mountain obscuration across all of Southwestern, Central, and
North-central Montana during first 6 hours of this TAF Period.
-IG

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  49  25  69  48 /  20  10   0  20
CTB  49  22  70  45 /  20   0   0  10
HLN  49  26  69  47 /  20  10   0  20
BZN  48  21  64  39 /  20  10   0  10
WYS  44  16  56  31 /  10  10   0  10
DLN  50  22  65  41 /  20  10  10   0
HVR  50  21  66  39 /  20   0   0  10
LWT  44  20  59  40 /  20  10   0  10

&&

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

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