516
FXUS65 KTFX 110244
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
844 PM MDT Mon Jun 10 2024


.SYNOPSIS...

This afternoon and evening an upper-level trough moves
through North-central Montana which will bring isolated showers and
maybe a few rumbles of thunder to the Hi-Line. For the rest of the
area today will be dry, breezy, and warm. Tuesday and Wednesday will
be warm, dry, and windy with the strongest wind gusts along the
Rocky Mountain Front and adjacent plains. Dry conditions will
persist until Friday when Southwestern Montana has the potential for
showers and thunderstorms when a new upper-level system begins to
move into the area. Next weekend it will be cool with the potential
for precipitation.

&&

.UPDATE...

A small upper level disturbance passing through North-Central MT
will continue to bring isolated to scattered light showers this
evening. These will dissipate a little bit after sunset. With a
small amount of instability hanging around, there`s a small chance
for an isolated rumble of thunder with showers. Main adjustments
for the update were adjusting PoPs to reflect the current radar
trends with showers. Other than that, the rest of the forecast is
on track. -Wilson


&&

.AVIATION...

11/00Z TAF Period

VFR conditions will continue through at least 12/00Z across North
Central (KCTB, KHVR), Central (KLWT, KGTF, KHLN), and Southwest
(KBZN, KEKS, KWYS) Montana.

The scattered to broken mid-level cloudiness in the lingering
northwesterly flow aloft will decrease through 04Z. Although a few
showers may move east-southeast along the Hi-Line (mainly over KHVR)
during this time, they should be light and brief and should not
reduce conditions significantly. Otherwise, high pressure will move
into the area through the remainder of the period, keeping skies
mostly clear to partly cloudy. However, a disturbance will help
flatten the ridge somewhat after 18Z, causing an increase in
westerly mid-level winds that will at least partially translate down
to the surface, especially over the plains. -Coulston

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

&&

.PREV DISCUSSION...
/ISSUED 555 PM MDT Mon Jun 10 2024/

This afternoon through Wednesday... This afternoon a fast-
moving upper-level trough moves across the Hi-Line. The upper-level
trough will bring isolated showers with a few rumbles of thunder
along the Hi-Line this afternoon and evening. Some the showers could
sneak a little farther south in North-central Montana. For the rest
of North-central, Central, and Southwestern Montana it will be dry,
breezy, and warm this afternoon and evening. Due to warm
temperatures melting snowpack in combination with recent rainfall
rivers, streams, and creeks are cold, fast flowing, and near bank
full across Southwestern Montana. Due to no additional rainfall
expected until Friday, there are no flood concerns at this time.
Continue to monitor the forecast for updates. On Tuesday an upper-
level ridge moves over North-central, Central, and Southwestern
Montana with strong upper-level flow. This will cause breezy to
strong winds and wind gusts across the area for Tuesday along with
warmer temperatures. Along the Rocky Mountain Front there is a 60 -
80% chance for wind gusts exceeding 55 mph on Tuesday. Along the
plains adjacent to the Rocky Mountain Front there is a 50% chance
for wind gusts exceeding 55 mph on Tuesday. For the lower-elevations
of North-central, Central, and Southwestern Montana there is a 30 -
50% chance for wind gusts exceeding 40 mph on Tuesday. Tuesday
evening a weak and dry cold front moves through North-central,
Central, and Southwestern Montana. This will slightly cool down high
temperatures across the area on Wednesday. On Wednesday there will
be strong upper-level zonal flow, which will keep breezy to strong
winds and wind gusts in place across North-central, Central and
Southwestern Montana. Along the Rocky Mountain Front there is a 70 -
90% chance for wind gusts exceeding 55 mph on Wednesday. Along the
plains adjacent to the Rocky Mountain Front there is a 50% chance
for wind gusts exceeding 55 mph on Wednesday. On Wednesday across
Northern Blaine County there is a 60 - 80% chance for wind gusts
exceeding 47 mph. For the rest of the lower-elevations of North-
central, Central, and Southwestern Montana there is a 30 - 60%
chance for wind gusts exceeding 40 mph on Wednesday. Even with low
humidity and breezy to strong winds on Tuesday and Wednesday
there will be limited to no fire weather concerns due to recent
rainfall and green fuels.

Thursday and Friday... On Thursday an upper-level ridge will move
over North-central, Central, and Southwestern Montana. This will
allow the dry conditions to persist. It will also allow there to be
sunny skies with slightly above seasonal average temperatures for
North-central, Central, and Southwestern Montana. On Friday the
upper-level ridge remains in place over North-central, Central, and
Southwestern Montana. On Friday afternoon/early evening an upper-
level disturbance associated with a surface cold front will move
through North-central, Central, and Southwestern Montana. This will
bring the potential for showers and thunderstorms to Southwestern
Montana. This will need to be monitored for updates. Friday will be
the warmest day of this forecast period. On Friday the Fort Benton
area to Great falls and the Helena and Gallatin Valleys have a 25 -
50% chance for high temperatures of 90 degrees or greater.

Saturday through next Monday...On Saturday clusters indicate that an
upper-level trough will move over North-central, Central, and
Southwestern Montana. The strength of the upper-level trough in the
four clusters varies. However, this indicates that the weather
pattern will change to have cooler temperatures with the possibility
for precipitation for North-central, Central, and Southwestern
Montana. On Sunday three clusters (85% of ensemble members) keep the
upper-level trough over North-central, Central, and Southwestern
Montana. The other cluster (15% of ensemble members) has zonal flow
over the area. This indicates that most likely the weather on Sunday
will be similar to that on Saturday for North-central, Central, and
Southwestern Montana. On Monday clusters indicate that the upper-
level trough will remain over the area. This means that for the
Saturday to next Monday period it will be cooler with the potential
for precipitation across North-central, Central, and Southwestern
Montana. -IG

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  50  83  50  79 /   0   0   0   0
CTB  48  79  46  72 /  10   0   0   0
HLN  53  85  53  83 /   0   0   0   0
BZN  46  84  49  84 /   0  10   0   0
WYS  40  74  42  78 /  10  10   0   0
DLN  46  82  48  83 /   0   0   0   0
HVR  51  84  54  79 /  30   0   0   0
LWT  47  79  48  78 /  10   0  10  10

&&

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

$$

http://www.weather.gov/greatfalls