742
FXUS65 KTFX 042328
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
528 PM MDT Wed Jun 4 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Showers and isolated thunderstorms will decrease this evening with
   a few isolated showers and weak thunderstorms possible again
   each afternoon through Saturday.

 - Temperatures gradually warm to above seasonal averages by the
   weekend with the warmest conditions expected on Monday.

 - A transition back to seasonal temperatures with opportunities
   for precipitation is expected next week.

&&

.DISCUSSION...
/Issued 301 PM MDT Wed Jun 4 2025/

 - Meteorological Overview:

Area remains beneath cyclonic NW flow aloft within the broad
circulation of an upper level trough centered near Hudson Bay.
Subtle shortwave disturbances moving through the NW flow and daytime
instability beneath relatively cool air aloft has led to the
development of scattered showers with the possibility of a few
weak thunderstorms and similar development is expected Thursday
afternoon. Gradual warming aloft will lead to increased stability
with a more limited coverage of isolated showers and thunderstorms
by Friday and Saturday.

An upper level ridge shifts inland later this weekend and across the
Northern Rockies on Monday. Temperatures warm to well above average
by Monday beneath the upper ridge and are likely to remain warm on
Tuesday as a southwest to westerly flow develops as the ridge
progresses east of the area. Longer range model ensembles generally
support a more zonal flow with some embedded moisture developing by
the middle of next week with potential for deeper troughing moving
onshore late next week. There is still a wide spread in details but
a transition back to more seasonal temperatures with increased
chances for showers and thunderstorms is likely as this pattern
develops mid-late next week.

 - Forecast Confidence & Scenarios:

High resolution/short range model ensembles give areas along the
Rocky Mountain Front and over the Little Belts the highest risk (30-
50%) for lightning this afternoon with much lower probabilities
(15% or less) across the plains and valleys. Similar probabilities
for lightning are forecast for late Thursday with most southwest MT
mountain ranges also having a 20-40% risk for lightning.

There is a 30-50% chance that maximum temperatures reach or exceed
90F on Monday, primarily across portions of north-central MT below
4000 ft (Great Falls, Cut Bank, Havre) while probabilities are 20%
or less elsewhere including Helena, Lewistown and Bozeman. Hoenisch

&&

.AVIATION...
05/00Z TAF Period

Scattered showers will diminish this evening with the loss of
diurnal heating, but a few lighter end showers may persist into
the overnight hours, mostly along the Rocky Mountain Front.
Continued northwesterly flow aloft will bring another round of
scattered primarily afternoon/evening showers and possibly a
thunderstorm on Thursday. VFR conditions are generally expected
for the duration of the TAF period with the exception of mountain
obscuration, passing lower and mid- level clouds, and brief/minor
reduction in visibility near showers. - RCG

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  41  72  46  80 /  20  10   0   0
CTB  39  73  45  78 /  20  10   0   0
HLN  45  75  48  81 /  20  20   0   0
BZN  38  70  41  78 /  10  20   0   0
WYS  29  65  30  70 /  10  30  10  10
DLN  36  68  41  76 /   0  20   0   0
HVR  42  75  46  83 /  20  10   0   0
LWT  40  67  43  75 /  40  30   0   0

&&

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

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