605
FXUS65 KTFX 092027
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
127 PM MST Sat Nov 9 2024

.KEY MESSAGES...

 - Warm and dry weather today, with above average temperatures
   through well into next week.

 - Two separate systems bring lower elevation rain/mountain snow
   Sunday through Tuesday across the Continental Divide and
   Southwest Montana.

 - Gusty winds settle in next week across the Rocky Mountain
   Front and the plains.

&&

.DISCUSSION...

 - Meteorological Overview:

Weak upper-level ridging in the area will keep the region warm
and dry today. On Sunday, a weak upper-level shortwave trough
quickly moves across the region. This will bring light
precipitation to the Continental Divide and higher terrain of
Southwest MT. Behind this wave, another broad upper level trough
moves in Monday and Tuesday. This will bring in gusty winds to the
Rocky Mountain Front and plains, with widespread precipitation
along the Continental Divide Southwest/Central MT. Some weak
upper-level ridging follows behind, but stronger mid-level winds
aloft will keep gusty winds through the week. Towards the end of
the work week, another trough could bring more widespread
precipitation to the region.

 - Forecast Confidence & Scenarios:

Short term and medium range models are in good agreement in keeping
the region dry today, and the shortwave passage Sunday keeping
precipitation minimal. There`s high confidence the higher terrain
accumulating up to an inch of snow, with lower elevations seeing
trace amounts of rain.

Even with weak ridging over the region Monday, stronger mid-level
winds will keep breezy conditions primarily across the Rocky
Mountain Front. The break down of the ridge Monday night and
Tuesday will help bring in stronger winds to the Rocky Mountain
Front and plains. The NBM(National Blend of Models) have a 50-70%
chance for 58mph winds along the Rocky Mountain Front. However,
confidence is not as high for widespread 58mph+ wind gusts, so I
held off from issuing a High Wind Watch. Though, we will continue
to monitor the potential for one for future forecast packages.
This upper-level trough also brings more widespread precipitation
to the areas primarily along the Continental Divide and Southwest
MT Monday and Tuesday. There`s a 30-60% chance of 4" of snow at
the higher peaks Southwest MT and the Northern Divide, and a
30-60% chance for 3" at Marias Pass and pass level in Southwest
MT.

Ensembles hint at snow lingering along the Northern Divide
through the rest of the week and gusty winds across the Rocky
Mountain Front and the plains. Ensembles are also in agreement of
another upper-level trough moving through Friday evening and
Saturday, bringing widespread precipitation again. Slight
variations of this trough in models gives too much uncertainty for
any details this far out. -Wilson

&&

.AVIATION...
09/18Z TAF Period

Generally VFR conditions will prevail before 06z Sun. However, low
clouds and fog will affect areas around Cut Bank and Helena for the
next few hours. After 06z Sunday, expect lowering ceilings, with
showers developing along the divide. Breezy west winds will develop
out over the northern Plains on Sunday morning. Brusda

The KWYS TAF will not be issued until airport operations resume next
spring.

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  42  52  35  59 /  10  10   0   0
CTB  37  48  28  55 /  10   0   0   0
HLN  33  50  32  59 /   0  30   0   0
BZN  27  49  27  56 /   0  20  10   0
WYS  16  38  19  43 /   0  40  30  10
DLN  30  47  27  51 /   0  10   0   0
HVR  35  50  27  57 /  10   0   0   0
LWT  33  50  30  57 /   0  20  10   0

&&

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

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