943
FXUS65 KTFX 032007
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
207 PM MDT Mon Jun 3 2024

.SYNOPSIS...

Scattered rain showers continue and a few thunderstorms this evening
across Central and Southwest Montana with primary concern being
gusty winds. Strong winds tonight through Wednesday. Dry conditions
and warm afternoon high temperatures Thursday into the weekend.

&&

.DISCUSSION...

Rest of today through Wednesday night...Upper level troughing
continues across the state today bringing unsettled weather
conditions through tomorrow. A cold front from the Pacific Northwest
continues to move across the state this evening. Scattered light
rain showers across Central and Southwest Montana, and along the
Rocky Mountain Front continues through this evening. A few
thunderstorms have potential to develop this evening across
Southwest Montana from a Bozeman to Lewistown line into Central
Montana as the front pushes through. Primary concerns for any
developed thunderstorms are gusty winds. Scattered rain shower and
thunderstorm activity diminishes between 6 pm and 9 pm this
evening. Along the Hi-Line, there`s a 30 to 40 percent probability
of a rain shower coming down from Canada between midnight and 3
am. Otherwise, conditions become drier this evening and strong
winds reaching warning criteria start along the Rocky Mountain
Front into North Central Montana. We are strongly advising
limiting outdoor recreation between tonight and Wednesday along
the Rocky Mountain Front as wind probabilities are high (greater
than 75 percent) for wind gusts reaching over 65 mph periodically
during this timeframe. High profile vehicles will have difficulty
traveling over mountain passes due to these strong winds. High
Wind Warnings continue through Wednesday for the Rocky Mountain
Front. For everywhere else for the High Wind Warnings, timing is
still on track to start this evening for tonight into tomorrow
morning and continue through the Wednesday morning hours. We held
off on including Helena as latest probabilities are still not
supporting high wind criteria. It`ll still be windy nevertheless.

As the upper level trough departs tomorrow, upper level ridging
builds in for Wednesday with dry and windy conditions, especially
along the Rocky Mountain Front Wednesday morning into the
afternoon and across the eastern portion of North Central and
Central Montana.

Thursday through this upcoming weekend...Ensemble model guidance
is still in support for upper level ridging to continue during
this timeframe. Drier conditions are favored for our region under
surface high pressure. Beyond Sunday remains uncertain on whether
upper level ridging continues or begins to move out and upper
level troughing moves in from the west. The Climate Prediction
Center has our region in likely above (60-70% probability) of
above normal temperatures for this weekend into early next week.
This could mean we see temperatures 2 degrees above normal or 10
degrees in some locations. Our normal high temperatures this time
of year (middle of June) is between 75 and 80 degrees, with the
exception of higher mountainous terrain where it`s cooler. We`ll
continue to monitor ensemble model trends for heat risk potential
for this upcoming weekend as well as when upper level ridging will
begin to move. Webb

&&

.AVIATION...

03/18Z TAF Period

Primary concern for this afternoon and early evening will be
convective showers and isolated thunderstorms associated with a
Pacific cold front. Although there will be little in the way of
lightning and mostly VFR conditions, stronger upper level winds and
cold air advection aloft increase the chances for showers
transferring wind gusts in excess of 35 kts to the surface. This
will be most likely to occur over locations south and east of a KHLN
to KHVR line where there is around a 40 to 70% chance for gusts over
30 kts. Strong westerly flow moves in behind the cold front with
winds initially increasing tonight along the Rocky Mountain
Front/central ranges and their adjacent eastern plains. Very windy
conditions are then expected over much of Central/North-central MT
on Tuesday. Expect mountain wave activity to increase along with
instances of low level wind shear. - RCG

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  44  67  47  71 /  10   0   0   0
CTB  41  61  43  67 /  10   0  10   0
HLN  44  69  51  76 /  10  10  10   0
BZN  38  70  49  77 /  60  10   0   0
WYS  36  61  42  73 /  80  10   0   0
DLN  39  67  48  78 /  20  10   0   0
HVR  46  71  48  71 /  40  10   0   0
LWT  39  67  46  68 /  40   0   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
High Wind Warning from 6 PM this evening to noon MDT Wednesday
for Bears Paw Mountains and Southern Blaine-Big Belt, Bridger
and Castle Mountains-Cascade County below 5000ft-East Glacier
Park Region-Eastern Glacier, Western Toole, and Central Pondera-
Eastern Toole and Liberty-Fergus County below 4500ft-Judith
Basin County and Judith Gap-Little Belt and Highwood Mountains-
Meagher County Valleys-Northern High Plains-Snowy and Judith
Mountains-Southern High Plains-Southern Rocky Mountain Front-
Upper Blackfoot and MacDonald Pass.

High Wind Warning from 9 AM Tuesday to noon MDT Wednesday for
Eastern Pondera and Eastern Teton-Hill County-Northern Blaine
County-Western and Central Chouteau County.

&&

$$

http://www.weather.gov/greatfalls