116
FXUS65 KTFX 031900
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
100 PM MDT Wed Jun 3 2026

.KEY MESSAGES...

 - Showers and thunderstorms develop late tonight and persist
   through Thursday afternoon.

 - Temperatures warm above normal on Friday, but cool back below
   normal over the weekend.

 - Gusty winds develop on Friday and Saturday over Southwest
   Montana.

&&

.DISCUSSION...

 - Meteorological Overview:

Transient ridging will slide over the Northern Rockies this evening
and through the early morning hours on Thursday ahead of a fast,
compact shortwave and attendant Pacific front, which will then move
over/across Southwest through North Central Montana through the mid-
morning and afternoon hours on Thursday. Clear to partly clear skies
late this afternoon and early this evening combined with light winds
and recent precipitation may support the development of fog in the
Milk River Valley of North Central Montana and the high, fog prone
valleys in Southwest and Central Montana. As the aforementioned
ridge begins to slide east of the region late this evening and
through the early morning hours on Thursday cloud cover and chances
for precipitation will begin to increase from west to east, with
precipitation chances peaking between sunrise and the early
afternoon hours on Thursday. The highest chances for showers and
thunderstorms over this timeframe will exist along and south of the
Montana Hwy 200 corridor and north of the I-90 corridor, with
generally a 20-50% chance for showers and storms elsewhere. While a
stronger thunderstorm or two can`t be ruled out on Saturday, most
notably over Fergus and Judith Basin Counties, the overall early
nature of the Pacific front and preluding clouding conditions will
help to limit instability across the area. Another period of
transient ridging looks to move over the Northern Rockies during the
overnight hours of Thursday, with increasing southwesterly flow then
settling in on Friday over Southwest through North Central Montana.
High temperatures look to climb above normal on Friday thanks to the
the southwest flow aloft, with gusty south to west surface winds
developing during the afternoon hours. Overall dry conditions can be
expected on Friday, but an isolated afternoon/evening thunderstorm
can`t be ruled out over the Bears Paw/Little Rocky Mountain areas. -
Moldan

For Saturday afternoon into early next week...an unstable
southwesterly flow will develop over the CWA. This will result in
daily chances for showers and thunderstorms to move through the CWA.
At this time, most of the severe storms should be to our east, but
an isolated strong/severe storm is possible. Overall, temperatures
will be a bit above normal most days, except on Sunday, when
temperatures are likely to be a few degrees below normal.

 - Forecast Confidence & Scenarios: With warm air moving in aloft
today, the forecast models want to keep the CWA dry. However, with
recent moisture, the airmass is likely to become a bit unstable with
any heating over North Central MT, thus kept low pops in the
forecast, especially for areas along the Highway 2 corridor from
Shelby to Harlem.

There is the potential that a few strong storms could develop over
the eastern portions of the CWA on Saturday, but they should quickly
move off to the northeast. Brusda

 - Forecast Confidence & Scenarios:

Gusty Winds on Saturday...

H700-500 south to southwest flow will increase over Southwest
Montana through the day, with values reaching 1 to 2 standard
deviations above normal by the afternoon and evening hours. Deep
mixing during this timeframe will help to transport the strong winds
to the surface, most notably along and southeast of a Dillon, to
Ennis, to Bozeman line where ECMWF EFIs of 0.6 to 0.75 indicate the
potential for a climatologically unusual wind events. NBM5.0
probabilities for wind gusts of 40 mph or greater are in excess of a
70% chance along and south of a Dillon, to Ennis, to Big Sky line,
with a 20-50% chance for gusts to exceed 55 mph across these same
areas. Wind gusts exceeding 55 mph are entirely possible beneath
decaying showers and thunderstorms, most notably in the Dillon and
Ennis Areas. - Moldan

Strong Thunderstorms on Saturday...

There is the potential that a few strong storms could develop over
the eastern portions of the CWA on Saturday, but they should quickly
move off to the northeast. Brusda

&&

.AVIATION...
03/18Z TAF Period

VFR conditons will prevail at all but the KGTF and KHVR terminals
during this TAF Period. At the KGTF and KHVR terminals there will be
MVFR-level ceilings for a few hours at the beginning of this TAF
Period. After 04/00Z rain will begin to affect terminals beginning
in Southwestern Montana and spreading up to North-central Montana by
04/12Z. During the beginning and end of this TAF Period there will
be instances of mountain obscuration primarily across North-central
Montana. -IG

&&

.HYDROLOGY...

The latest hydrographs show river levels decreasing over the
southwestern portions of Glacier County. This includes the Two
Medicine River and Badger Creek. Thus if no new reports of
flooding are received this morning, it is likely the flood
advisory for southwestern Glacier County will expire at Noon
today, or even be cancelled early. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  48  70  42  78 /  40  50  10   0
CTB  45  71  41  73 /  20  20   0   0
HLN  52  72  42  80 /  40  30   0   0
BZN  45  71  39  80 /  30  40   0   0
WYS  37  67  33  72 /  10  20  20   0
DLN  45  72  40  80 /  20  20   0   0
HVR  42  72  45  78 /  10  60  20   0
LWT  43  66  40  77 /  50  70  20   0

&&

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

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