National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS65 KTFX 242105
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
305 PM MDT Wed Apr 24 2024

.SYNOPSIS...

Clouds will be on the increase tomorrow as our next weather system
begins to push into the area. Expect cool and wet weather Friday
and Saturday, with significant snow accumulations possible above
7000 feet. The cooler and active weather pattern will continue
through at least the middle of next week.

&&

.DISCUSSION...

Key Points:

-Warmth continues through Thursday
-Cooler and wetter weather arrives Friday and Saturday with some
 higher elevation snow
-Temperatures moderate early next week, even as rain chances
remain

Short term (through Thursday)... Warm temperatures and mostly
clear skies have been the norm today as a ridge of high pressure
centered just to our east allows warm southwesterly flow to bring
warm air into North Central and Southwestern Montana today. While
skies have been clear so far, the warm southwesterly flow will
have sufficient moisture with it to kick off a few showers and
maybe a thunderstorm or two, especially across Southwestern
Montana and even onto the plains of North Central Montana.
Thursday will see warmth continue across North Central and
Southwestern Montana, though increasing clouds will hold
temperatures slightly cooler tomorrow. Expect highs tomorrow to
generally be in the 60s area wide. As we head into the evening,
the clouds will begin to result in some mountain snow and valley
rain across Southwestern Montana, mainly southeast of a line from
Dillon to White Sulphur Springs. While this will be the beginning
of our next weather event, Thursday will not see much in the way
of significant impacts, as precipitation will generally be light
and snowfall totals generally confined to the highest peaks.

Extended (Friday through next Wednesday)... As a broad and slow
moving upper level low pressure system begins to push into the
Intermountain West, precipitation will begin to become more
widespread and more intense, especially South of I-90. As this
precipitation continues, we will see a combination of dynamic
cooling, wet bulbing, and some advection of cooler air coming in
from the north. This combination of cooling effects will result in
noticeably cooler temperatures across the area, keeping highs
across the area in the 50s Friday and Saturday across the lower
terrain, with temperatures staying closer to freezing above 7000
feet. With this in mind, we will see some significant
accumulations of snow across the mountains south of I-90, with
some peaks seeing 12-18” of snowfall between Friday and Saturday.
At lower elevations, precipitation should be mostly rain, though I
cannot rule out some brief periods of snow reaching the ground
where some heavier precipitation sets up. With all of this in
mind, I have gone ahead and issued a Winter Storm Watch for the
mountains south of I-90 for this event.

As we head into the day on Sunday, we will begin to dry out as
our weather system begins to push off to the east and upper level
flow becomes southwesterly. While this will result in a dry day on
Sunday across the plains, we will see precipitation return to the
higher terrain of the southwest as our next weather system pushes
in from the west. This active weather pattern will continue into
at least the middle of next week, though there is considerable
uncertainty on the number and timing of systems next week. Ludwig

&&

.AVIATION...
1112 AM MDT Wed Apr 24 2024 (24/18Z TAF Period)

VFR conditions are predominately expected through 09z Thursday;
however, low to upper level cloud cover will be increasing from
southwest to northeast across the Northern Rockies as a disturbance
moves across the Western US. Isolated to scattered rain showers are
expected to develop during the afternoon hours and persist through
the overnight hours southwest of a KHVR, to KGTF, to KHLN line, but
confidence in any one shower impacting a terminal was too low to
mention at this time. Main impact from any showers will be gusty and
erratic winds and CIGS lowering to low-VFR. Beyond 09z Thursday,
CIGS across Southwest Montana are expected to lower to MVFR/low-VFR,
with continued chances for rain showers. Mountains will become
increasingly obscured beyond 03z Thursday. - Moldan

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  43  66  41  58 /  20  10  10  50
CTB  38  60  37  51 /  10   0   0  30
HLN  44  67  42  59 /  20  10  20  70
BZN  39  64  38  55 /  20  50  70  90
WYS  33  55  32  49 /  30  80  70  90
DLN  39  63  38  53 /  20  40  50  80
HVR  43  68  40  65 /  10   0   0  10
LWT  41  63  39  54 /  20  20  40  60

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Friday morning through late Saturday
night for Gallatin and Madison County Mountains and Centennial
Mountains-Northwest Beaverhead County-Ruby Mountains and
Southern Beaverhead Mountains.

&&

$$

http://www.weather.gov/greatfalls