National Weather Service Weather Forecast Office

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

000
FXUS65 KTFX 112059
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
259 PM MDT Thu Apr 11 2024

.SYNOPSIS...

Warm weather is expected over the next few days as southwesterly
flow aloft brings in warmer air from the south. While most of us
will stay dry the next few days, we will see a few showers and
thunderstorms develop each of the next few afternoons, especially
across Southwestern Montana. Cooler and wetter weather will return
next week.

&&

.DISCUSSION...

Key Points:

- Mostly dry this weekend with a few isolated showers and
thunderstorms, especially Friday

-There is the potential for an impactful winter storm to affect
the area area early to mid next week

Short Term (Through Sunday)... Current radar and satellite
imagery this afternoon shows a dry and clear day across North
Central and Southwestern Montana as high pressure both aloft and
at the surface exert control over our weather today. While the
upper level ridge will keep us warm through the weekend, a low
pressure system diving south along the Pacific Coastline will push
some moisture into the area on Friday, which will help kick off
some showers and thunderstorms across the area. While organized
severe weather is not expected, we have enough shear and DCAPE
(the potential for air to cool from rain and move towards the
ground) that could result in some isolated gusty outflow winds.
Otherwise, fans of warmer weather will rejoice across the area
tomorrow as temperatures reach the upper 60s and low 70s across
the lower elevations. Warm and mostly dry weather continues
Saturday and Sunday as the ridge continues to maintain control of
the weather, with just a few afternoon showers and storms. Ludwig

Monday through next Thursday... Ensemble cluster analysis are in
fairly good agreement for Monday into Wednesday in forecasting a
secondary low pressure center to move southeast into the Northern
Rockies and adjacent plains to merge with the Great Basin low.
Therefore, there is increasing confidence in a change to a much
cooler and wetter weather pattern. The uncertainty with this
change will be just how cold it may get and how much precipitation
will fall as snow at lower elevations. As of right now, the NBM
keeps the 60+ percent probability of 6+ inches of snow in the
mountains for the 72-hour period of Monday through Wednesday,
while lower elevations adjacent to mountain foothills only have a
20 to 40 percent chance. Some uncertainties regarding snow
amounts at lower elevations include - how much snow will melt
before it sticks; and will temperatures cool more rapidly than
the NBM indicates, resulting in more snow than currently expected
at lower elevations. Also concerning will be associated winds
during the Monday into Tuesday timeframe. Overall, they are not
expected to be exceptionally strong, as NBM probabilities of both
sustained winds of 25+ mph and gusts of 40+ mph will be greater
than 60 percent, but most areas will only have up to a 20 percent
probability of high wind criteria winds (sustained 40+ mph, gusts
58+ mph). Monday should be warm enough to limit any blowing snow
threat, but temperatures cooling below normal on Tuesday with a
shift from westerly winds to more northerly winds may increase the
blowing snow threat. Lots of uncertainty that will need to be
examined over the next couple of days. The NBM indicates that
conditions should improve Wednesday into Thursday, but the
clusters start to diverge in their solutions, so uncertainty
exists in that part of the forecast as well. -Coulston

&&

.AVIATION...
1145 AM MDT Thu Apr 11 2024 (11/18Z TAF Period)

VFR conditions will prevail throughout the duration of the 1118/1218
TAF period as upper level ridging moves over the Northern Rockies
through this afternoon. By the evening hours mid-level cloud cover
will begin to increase as the aforementioned ridge shifts east over
the Northern High Plains, with increasing southwesterly flow aloft.
This will bring increasing winds to the south-north orientated
valleys in Southwest Montana (i.e. KEKS terminal), with wind gusts
in excess of 25kts becoming increasingly likely through the evening
hours on Thursday. Mountain obscuration is not expected until after
18z Thursday, mainly along the Continental Divide and in the
vicinity of KBZN. - Moldan/thor

Equipment Note: ASOS data is not currently available for
KHLN and, as a result, amendments are not scheduled at this time.

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  41  72  43  73 /  10  20  20  10
CTB  36  66  38  70 /  10  10   0   0
HLN  41  76  45  75 /   0  20  20  20
BZN  38  74  39  75 /   0  10  20  20
WYS  27  62  30  63 /   0  10  10  10
DLN  37  71  39  73 /   0  10  10  10
HVR  37  71  42  73 /   0  10  10   0
LWT  37  70  40  68 /   0  20  30  20

&&

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

$$

http://www.weather.gov/greatfalls