415
FXUS65 KTFX 221651
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1051 AM MDT Sun Sep 22 2024

...Aviation Section Updated...

.SYNOPSIS...

Westerly winds increase today while temperatures warm closer to
average. An approaching weather system will increase middle and
higher level clouds by this afternoon before bringing isolated
lighter end shower activity tonight into early Monday. Much warmer
and dry conditions are expected for Tuesday and Wednesday.

&&

.UPDATE...

Increasing westerly to northwesterly flow aloft will result in a
pressure gradient developing over the plains through the day today
and tonight. Breezy westerly winds will be the theme today across
the plains as a result, with at least a light wind persisting
tonight out of the west. A weak wave passing through this
increasing westerly to northwesterly flow tonight will bring a
narrow window for a few showers late tonight into early tomorrow
across Central and North-central Montana. The only change to the
forecast this morning was to increase winds a bit in areas where
winds have developed already this morning. -AM

&&

.AVIATION...
22/18Z TAF Period

VFR conditions will prevail throughout the 2218/2318 TAF period;
however, mid- and upper level cloudiness will continue to increase
over the Central and North Central Montana through 00z Monday and
across Southwest Montana between 00-06z Monday. While an isolated
shower or two are possible between 03-12z Monday across the Northern
Rockies, little to no precipitation is expected to reach the
surface given dry air in the low levels. Breezy and gusty west to
northwest winds at the KCTB and KGTF terminals, with gusts of 25-
35kts this afternoon, will gradually decrease beyond 00z Monday.
Mountain wave turbulence and instances of low level wind shear will
be possible over the next 12-18 hours. - Moldan

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

&&

.PREV DISCUSSION...
/ISSUED 532 AM MDT Sun Sep 22 2024/

Mostly clear skies are being observed early this morning aside
from some passing cirrus and the ongoing potential for AM patchy
fog development for some of the wind protected valleys. Westerly
winds are already increasing along the Rocky Mountain Front and
this will spread onto the plains later today. There is over a 70%
chance for gusts to exceed 40 mph along the Northern Rocky
Mountain Front eastward toward the Cut Bank area; otherwise, most
other Central/North-central locations should see gusts more in the
15 to 30 mph range.

Middle and higher level cloudiness will be on the increase today
as a Pacific shortwave approaches from the northwest. This system
is much weaker than last Friday`s, but it will still bring some
lighter end shower activity, mostly for Central/North- central MT
this evening through early Monday. Temperatures moderate to near
average toady and nearly hold steady on Monday.

High pressure aloft builds in Tuesday and Wednesday for dry and
very warm conditions. Most lower elevation temperatures will peak
in the lower and middle 80s Wednesday afternoon, about 15 to 20
degrees above average for this time of year. Most record highs for
Wednesday run from the upper 80s for the cooler southwest valleys
to the lower and middle 90s over the warmer central/north-central
areas, so widespread record breaking temperatures are not
expected at this time.

Most ensembles bring a trough onto the Pacific NW coast on
Wednesday before brushing the Northern Rockies on Thursday for a
slight cool down, breezy to windy conditions, and perhaps a few
showers or thunderstorms. Temperatures still remain above average
until the next cold front arrives around Saturday and brings more
seasonable conditions. The next chance for more widespread
precipitation looks to hold off until next Sunday/Monday or even
beyond. - RCG

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  75  46  73  45 /  10  20   0   0
CTB  69  43  69  46 /   0  10   0   0
HLN  75  50  73  46 /   0  10   0   0
BZN  71  43  70  40 /   0  10   0   0
WYS  67  31  64  30 /   0  10   0   0
DLN  72  41  68  39 /   0  10   0   0
HVR  71  47  71  45 /   0  10   0   0
LWT  70  45  67  42 /   0  10   0   0

&&

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

$$

http://www.weather.gov/greatfalls