National Weather Service Weather Forecast Office

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

000
FXUS65 KTFX 241712
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1112 AM MDT Wed Apr 24 2024

...Aviation Section Updated...

.SYNOPSIS...

It will be a bit on the warm side today, with afternoon
temperatures in the 70s for many lower elevation locations. Do
expect a few late day showers though over Central and Southwest
MT. On Thursday, a cooling trend starts, with a few thunderstorms
possible over Southwest MT. By Friday, widespread lower elevation
rain and mountain snow develops over much of Central MT. The cool
and wet conditions will continue through at least Saturday.

&&

.UPDATE...

Overall, the forecast is mostly on track so far this morning. The
one change I made was to tweak POPs to be more in line with the
latest Hi-Res guidance, which has been honing in on the Bridgers
and Gallatin Mountains a bit more. 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.

&&

.PREV DISCUSSION...
/ISSUED 525 AM MDT Wed Apr 24 2024/
Today through Thursday...It will be a quiet morning over the CWA,
with just some passing clouds. Do expect increasing clouds once
again this afternoon. With good mixing and dry air in place,
afternoon temperatures were raised just a few degrees above NBM
for today. There will be a few late afternoon/evening showers
over Central and Southwest MT as an upper level disturbance moves
through. On Thursday, expect similar conditions, expect it will be
a bit cooler, and with slightly more instability, there will be a
chance for thunderstorm over Southwest MT.

Friday through Sunday...A split upper level trof develops over the
western half of the US from Friday into Saturday. One piece of
energy goes into the Southwest US, while another piece of energy
moves into the Pacific Northwest, before dissolving as it moves
towards the West Yellowstone area. The end result is widespread
lower elevation rain and mountain snow to affect much of the CWA
from Friday into Sunday. The GFS continues to vary in the location
of the heavier precipitation, but most models are agreeing that
the mountains of Southwest MT will have periods of accumulating
snowfall. Overall, snow levels will generally be near/above 6000
feet this weekend. Some of the heavier snowfall is expected in the
mountains around Pony and Big Sky. Generally a 4 to 8 inch
snowfall is expected on Friday and again on Saturday in these
areas. With impacts being confined mostly to mountain areas, and
spread out over 2+ days, I think a winter weather advisory will be
the best way to handle the upcoming snowfall. However if snow
amounts increase a bit or snow levels lower, a winter storm
watch/warning might need to be issued. Otherwise, all models agree
that temperatures will be slightly below normal for Friday and
Saturday, before trying to go slightly above normal for Sunday.

Monday through Wednesday...The flow aloft will generally be
westerly next week, but also unsettled. Expect several upper level
disturbances to move from west to east through the CWA early next
week. This will result in periods of lower elevation rain and
mountain snow showers. Overall, temperatures next week look to be
close to seasonal averages for this time of year. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  76  44  67  40 /  10  20   0  10
CTB  70  38  60  37 /   0   0   0   0
HLN  76  45  67  42 /  10  20  20  20
BZN  74  39  64  38 /   0  30  70  70
WYS  64  32  54  32 /   0  30  90  80
DLN  70  40  62  39 /  10  30  50  50
HVR  76  44  69  40 /   0  10   0   0
LWT  71  41  61  39 /   0  20  20  40

&&

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

$$

http://www.weather.gov/greatfalls