336
FXUS65 KTFX 271101
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
501 AM MDT Fri Sep 27 2024

...Aviation Section Updated...

.SYNOPSIS...

The only blemish to the weather through the day Saturday will be a
period of breezy winds over the plains today. Otherwise, benign
conditions will prevail with temperatures rising quite a bit above
average both today and Saturday. Cooler and windier conditions
arrive Sunday into Monday behind a cold front.

&&

.DISCUSSION...

Through Saturday night... Zonal to southwesterly flow aloft will be
in place through the period as weak upper level ridging develops
across the interior CONUS. This largely will result in benign
conditions across the region, though winds will be on the breezy
side today, especially along the Northern Rocky Mountain Front and
adjacent plains late this morning through early afternoon. A speed
max within the 850-700 mb layer will largely miss the region to the
north this morning, though does clip the Northern Rocky Mountain
Front and adjacent plains briefly. Mountain wave activity will allow
for intermittent gusty conditions near the Rocky Mountain Front this
morning. Although I can`t quite rule out a mountain wave getting out
to Cut Bank this morning, the better chance for a strong wind gust
in that area will be associated with mixing out while the stronger
flow in the mid levels is still present. Mid-level flow decreases
through the day, leaving a narrow temporal opportunity for a
stronger gust to be realized. Due to this narrow window for stronger
gusts away from the immediate eastern slopes, and limited
probabilistic support for stronger wind gusts in general, I opted to
not issue a High Wind Warning.

Otherwise today and tomorrow are looking quite benign, with above
average temperatures persisting, with no chance for precipitation.

Sunday through next week... An upper level disturbance will break
down the weak ridge Sunday into Monday, bringing with it a cold
front and at least breezy conditions.  The timing of the cold front
looks to be during the day Sunday, which makes for a bit of a
difficult high temperature forecast. Areas further west and across
the plains are much more likely to see cooler highs than areas
further east and in Southwest Montana valleys. The cold front looks
to be mostly dry in nature, though does look to be quite breezy. The
chance for a 58 mph gust in the Browning to Cut Bank corridor Sunday
along and behind the front is roughly 40%. The chance for a 40 mph
gust is above 50% for all areas Sunday into Sunday evening.

Thereafter, the upper level pattern will oscillate between brief
weak riding and troughing through the rest of the week. Temperatures
will be up and down through the week as a result. Overall, much of
next week looks dry, with the Wednesday into Thursday featuring the
best chance (Largely less than 20% still) for precipitation. -AM

&&

.AVIATION...
27/12Z TAF Period

Strong, westerly flow aloft over Central and North Central Montana
through the late morning/early afternoon hours today will continue
to result in mountain wave turbulence and instances of low level
wind shear, especially near/over the KCTB terminal. Otherwise, VFR
conditions will prevail across all terminals in Southwest through
North Central Montana over the next 24 hours, but breezy and gusty
surface winds of 20-40kts can be expected at the KCTB, KHVR, and
KGTF terminals through the early evening hours tonight. Mountains
will remain unobscured throughout the duration of the 2712/2812 TAF
period. - Moldan

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  81  47  82  51 /   0   0   0   0
CTB  73  40  76  46 /   0   0   0   0
HLN  82  49  85  52 /   0   0   0   0
BZN  81  44  84  48 /   0   0   0   0
WYS  74  33  77  36 /   0   0   0   0
DLN  79  44  82  48 /   0   0   0   0
HVR  82  45  83  49 /   0   0   0   0
LWT  79  47  81  54 /   0   0   0   0

&&

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

$$

http://www.weather.gov/greatfalls