037
FXUS65 KTFX 241952
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
152 PM MDT Sat May 24 2025

.KEY MESSAGES...

- Low end chances for isolated showers and thunderstorms today.

- Chances for showers and thunderstorms increases Monday, with a few
  stronger storms and heavy downpours possible.

- Temperatures warm up to above average for the weekend and into
  next week.

&&

.DISCUSSION...

 - Meteorological Overview:

A small shortwave passing through will bring low chances for
isolated showers/thunderstorms this afternoon east of the Havre to
West Yellowstone line. Subsidence from the upper-level ridge
moving in and clearer skies tonight will bring another round of
patchy fog for the North-Central plains. However, winds will be
slightly stronger than this morning, which can limit fog
development. Sunday is currently trending drier with the ridge
building in. Better chances for showers and thunderstorms arrive
Monday along a frontal passage, potentially bringing a few
stronger storms. A small shortwave trough Tuesday will bring
another round of showers and thunderstorms. After Tuesday, the
upper level ridge dominates the region, but a nearby cut off low
aloft will try to sneak in a few disturbances for low chances for
showers and thunderstorms for the week. Temperatures will warm
throughout the forecast period, reaching to well above normal
towards next weekend.

 - Forecast Confidence & Scenarios:

For the thunderstorms on Monday and Tuesday, there`s a little
uncertainty in the potential for strong storms. For Monday, CAPE
increases to 500-1,000 J/kg which will be conducive for stronger
updrafts. However, weak vertical depth in shear can limit the
potential for strong storms. If shear and winds aloft remains
weak, then storms will be more stationary. This combined with a
tall, skinny CAPE profile will bring an increased risk for heavy
downpours. Inverted V vertical profile soundings can also bring a
gusty wind potential with showers/storms. Tuesday will have a
slightly less chance for stronger storms, with the threat being
mainly concentrated in the Southwest.

Even though next week is trending drier overall, there are still
chances for precipitation. An upper level trough may split into 2
waves and form cut off lows aloft early next week. Mini
disturbances from those waves moving into the region will bring
low end chances for precipitation during the second half of the
week. -Wilson

&&

.AVIATION...
24/18Z TAF Period

Predominately VFR conditions will prevail throughout the 2418/2518
TAF period as transient ridging slides east towards the Northern
Rockies through Sunday. The few exceptions will be the KHVR and
KLWT terminals through 00-03z Sunday where MVFR/low-VFR CIGS will
remain, with even a few showers and an isolated thunderstorm being
possible over/near the KLWT terminal through the afternoon hours
today. As skies clear this evening across the Northern Rockies the
potential for patchy fog development will increase; with the
latest HREF probabilities suggesting a 20% chance for VIS falling
below VFR at the KCTB and KHVR terminals and a 40-50% chance for
VIS falling below VFR within the vicinity of the aforementioned
terminals. Limited mountain obscuration is expected over the next
24 hours. - Moldan

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  42  76  46  80 /   0   0   0  20
CTB  41  76  45  80 /   0   0   0  10
HLN  45  78  48  81 /   0   0   0  20
BZN  39  74  41  78 /   0   0   0  20
WYS  30  69  33  71 /  10  10   0  30
DLN  40  72  43  76 /   0   0   0  30
HVR  42  77  47  79 /   0   0   0  10
LWT  41  69  43  72 /  10   0   0  10

&&

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

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