438
FXUS65 KTFX 311004
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
404 AM MDT Fri May 31 2024

.SYNOPSIS...

Seasonably mild and dry conditions are expected through Saturday
afternoon with another cool night tonight before a weak weather
disturbance brings a chance for showers and isolated
thunderstorms to some areas Saturday evening. A more significant
series of weather systems will bring wind and rain to the area
Monday and Tuesday with warmer and drier weather developing later
next week.

&&

.DISCUSSION...

Cyclonic west-northwest flow aloft on the periphery of upper level
troughing centered across central Canada will bring one more day of
near to slightly below average temperatures today and another cool
night tonight before a more zonal (W to E) flow develops across the
region this weekend and temperatures warm to near and slightly above
seasonal averages. A relatively weak disturbance moves across the
area Saturday evening with scattered showers and a few isolated
thunderstorms possible, mainly across central and southwest MT.

Early next week, an unusually strong (for early June) Pacific upper
level jet moves moves onshore with a fairly potent mid level wave
and surface low kicking out across MT/AB Monday night/Tuesday. Windy
conditions are expected to develop Monday as westerly flow aloft
increases ahead of the wave with very windy conditions likely
across much of the area Tuesday and potentially into Wednesday.
Latest probabilistic guidance maintains a 30-50% chance for gusts
exceeding 45 mph Tuesday across southwest MT with 60% or higher
probabilities across north-central MT, where there is a 90% risk
of gusts in excess of 55 mph for areas adjacent to the Rocky Mtn
Front. A plume of unusually deep Pacific moisture (PWATs 150-180%
of normal) streams across the area ahead of the wave on Monday
with the most widespread and persistent precipitation focused
along and west of the continental dive but showers are also likely
to the east, especially across central and southwest MT.

Late next week, there is strong model agreement to build an upper
level ridge across the interior western and NW US, resulting in
temperatures warming well above seasonal averages by the weekend.
Some uncertainty still exists with its amplitude and the W/E
placement of the ridge axis with larger differences arising next
weekend. Hoenisch

&&

.AVIATION...

31/06Z TAF Period

VFR conditions prevail this TAF period. Winds will remain generally
calm across all sites except KCTB through the overnight hours before
picking up across central and north-central Montana after 31/18Z.
Otherwise the main concern will be for scattered showers this
afternoon across eastern portions of the hi-line including KHVR. -
thor

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  67  38  75  49 /   0   0   0  20
CTB  64  37  70  44 /   0   0   0   0
HLN  70  42  77  51 /   0   0  10  20
BZN  67  37  75  46 /   0   0  10  30
WYS  61  33  67  41 /   0   0   0  30
DLN  67  39  74  46 /   0   0  10  20
HVR  67  39  75  50 /  10  10   0  10
LWT  62  37  72  46 /   0   0   0  40

&&

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

$$

http://www.weather.gov/greatfalls