301
FXUS65 KTFX 072056
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
256 PM MDT Tue May 7 2024

.SYNOPSIS...
Widespread rain and snow will affect North Central MT through
Wednesday, along with strong winds. Over Southwest MT, expect the
precipitation to be more scattered. Temperatures remain below
normal for the next few days, but do climb back up above normal
over the weekend and into early next week, along with drier
conditions.

&&

.DISCUSSION...
Key Points...Adjustments made to the high wind warning. Flood
statements issued, but no changes to the winter weather
statements.

Tonight through Wednesday...Rain, heavy at times will affect
North Central MT through Wednesday. There is an 80 percent chance
of 1 inch of rainfall over much of North Central MT, with a 40
percent chance for 2 inches of liquid. One concern is how low
will snow levels get. Snow levels are currently falling down to
about 4000 feet, with the possibility of snow levels falling down
to about 3500 feet. Thus snow is possible for the Great Falls
area, while periods of snow fall around Belt, Geyser and
Lewistown. With temperatures near freezing though, the snow will
melt a bit at the lower elevations, limiting snow accumulations.
However, some periods of heavier snowfall are possible at lower
elevations, which will reduce visibility. In the mountains for
elevations above 5000 feet, 6 to 12 inches of snowfall will be
common, with 1 to 2 feet in the Kings Hill and Big Snowy areas.
With a strong area of low pressure to our east, strong northwest
winds will continue. Blizzard conditions are likely tonight and
into Wednesday in the Kings Hill area. Elsewhere, the high wind
warning was expanded along the I-15 corridor from Great Falls to
Conrad as a period of strong winds are expected from now through
late tonight. Below normal temperatures are expected through
Wednesday as well.

Thursday through Tuesday...The main storm system moves off to the
east on Thursday, resulting in drier and warmer air moving in from
the west. Expect a warming trend to begin on Friday and then
continue through the weekend and into next week. Afternoon
temperatures will be around 10 to 15 degrees above normal at times
during this period. Weak upper level disturbances will try to move
southeast from Canada into the northeast portions of the CWA by
early next week. This could result in a few scattered showers or a
thunderstorm, however much of the area will likely remain dry.
Brusda

&&

.AVIATION...
1215 PM MDT May 7 2024 (07/18Z TAF Period)

VFR conditions will prevail until about 00Z for the KBZN, KEKS,
KWYS, and KCTB terminals. An area of concern today is strong wind
gusts at the KLWT, KHVR, and KCTB terminals where winds will gust
between 44 to 51 kts. These winds will die down by 00Z for all but
the KCTB terminal where wind gusts will stay strong throughout the
TAF period. At the KGTF and KHLN terminals winds will gust to 40 kts
until 22Z for the KGTF terminal and 06Z for the KHLN terminal.
Across all terminals through the end of the TAF period there will be
rain, a rain/snow mix, and/or snow showers. This will reduce
ceilings for all but the KLWT, KHVR, and KCTB terminals where the
ceilings will be reduced to IFR levels. At the end of this TAF
period at the KHVR and KLWT terminals there is the potential for fog
reducing visibility down to IFR levels but there was not enough
probabilistic support to include it in those TAFs. During the middle
of this TAF period there will be isolated instances of low-level
wind shear at the KCTB, KLWT, and KGTF. During this TAF period there
will mountain obscuration. There will also be instances of mountain
wave turbulence primarily during the beginning and middle of this
TAF period. -IG

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

&&

.HYDROLOGY...
Heavy rainfall in the Bears Paw mountains will result in minor
flooding on Beaver Creek and possibly Clear Creek. Flood
highlights are in effect for portions of North Central MT. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  31  43  38  58 / 100  90  80  30
CTB  32  44  32  61 / 100  90  20   0
HLN  34  46  40  62 / 100  90  70  20
BZN  32  46  34  57 / 100  90  90  30
WYS  26  46  29  55 /  90  80  40  10
DLN  33  48  37  58 /  80 100  50  10
HVR  38  57  40  65 / 100  90  50  20
LWT  29  41  35  50 / 100  90  90  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 6 AM MDT Wednesday for Bears Paw
Mountains and Southern Blaine-Cascade County below 5000ft-
Eastern Glacier, Western Toole, and Central Pondera-Eastern
Pondera and Eastern Teton-Eastern Toole and Liberty-Fergus
County below 4500ft-Hill County-Judith Basin County and Judith
Gap-Northern Blaine County-Snowy and Judith Mountains-Western
and Central Chouteau County.

Winter Storm Warning until midnight MDT Wednesday night for Big
Belt, Bridger and Castle Mountains-East Glacier Park Region-
Snowy and Judith Mountains-Southern Rocky Mountain Front.

Winter Weather Advisory from 6 PM this evening to 6 AM MDT
Wednesday for Bears Paw Mountains and Southern Blaine-Eastern
Toole and Liberty.

Blizzard Warning until midnight MDT Wednesday night for Little
Belt and Highwood Mountains.

Winter Weather Advisory from 6 PM this evening to noon MDT
Wednesday for Cascade County below 5000ft-Fergus County below
4500ft-Judith Basin County and Judith Gap.

Winter Weather Advisory from 6 PM this evening to midnight MDT
Wednesday night for Elkhorn and Boulder Mountains-Upper
Blackfoot and MacDonald Pass.

High Wind Warning until midnight MDT tonight for Big Belt,
Bridger and Castle Mountains-Meagher County Valleys.

Winter Storm Warning from 6 PM this evening to midnight MDT
Wednesday night for Gallatin and Madison County Mountains and
Centennial Mountains.

Flood highlights in effect for portions of North Central MT.

&&

$$

http://www.weather.gov/greatfalls