322
FXUS65 KTFX 250600
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1200 AM MDT Sat May 25 2024

...Updated Aviation Section...


.SYNOPSIS...

Showers and thunderstorms continue today and tomorrow as an
unsettled weather pattern continues across North Central and
Southwestern Montana. Expect warmer and drier weather for the
first part of next week, with another round of cooler and
unsettled weather possible for the middle of next week.

&&

.UPDATE...

Scattered rain showers and thunderstorms along the Hi-Line this
evening continue to diminish within the next 2 to 3 hours.
Probability of precipitation was updated to account for the
lingering showers as well as winds were updated to account for
the wind direction changes across Southwest and portions of North
Central Montana. Patchy fog has low probability (less than 30
percent) of developing along the Hi-Line tomorrow morning, but a
few spots that saw precipitation this evening could develop some
localized fog in the early morning hours tomorrow. The rest of the
forecast is on track for tonight into tomorrow afternoon where
the next round of precipitation is forecasted. Webb

&&

.AVIATION...
25/06Z TAF Period

VFR conditions will prevail during this TAF period at all terminals.
The main concern for this TAF period is rain showers and
thunderstorms Saturday afternoon and evening. At the KEKS, KBZN,
KWYS, KHLN, and KLWT terminals there is a 50% chance for
thunderstorms Saturday afternoon and evening and so a PROB30 group
was included for them in those TAFs. At the KGTF and KHVR terminals
late Saturday afternoon and evening there is a 50% chance for
thunderstorms and so a PROB30 group was included for those TAFs. At
the KCTB terminal there is a 50% chance for rain showers Saturday
afternoon and so a PROB30 group was included for it. At the KWYS,
KEKS, KBZN, and KLWT terminals there will be rain showers Saturday
afternoon through the end of the TAF period. At the KHVR and KGTF
terminals there is a 50% chance for rain showers Saturday afternoon
and early evening. Another concern for this TAF period are wind
gusts from 15 to 24 kts at the KHLN and KCTB terminals Saturday
afternoon and evening. Due to the rain showers, mountain obscuration
will occur intermittently primarily across Southwestern Montana
Saturday afternoon and evening. -IG

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

&&

.PREV DISCUSSION...
/ISSUED 550 PM MDT Fri May 24 2024/

Key Points:

-A few thunderstorms this evening and Saturday may bring some
isolated gusty winds

-Dry with comfortable temperatures for Memorial Day, with most
lower elevations reaching the low 70s

Short Term (through Saturday)... A more or less typical spring
day is in progress across North Central and Southwestern Montana
with a few rain showers and thunderstorms developing across North
Central Montana. For the most part, any rain showers or
thunderstorms will not be of much note, though a few isolated
heavy downpours and gusty winds to 40 mph will be possible,
especially considering that most of these showers are moderately
high based, with bases around 7000 feet with fairly dry air below
them. Looking at the Southwest, expect a mostly dry and partly
sunny day here, with just an isolated rain shower or two over the
higher terrain. Any showers and thunderstorms should quickly
dissipate after sunset.

Saturday will be a similar day to today, only just a few degrees
warmer across the Northern Plains as showers and thunderstorms
will tend to be more across Southwestern and Central Montana as
opposed to the plains that we have this afternoon. This setup will
bring some mostly beneficial rainfall to a decent portion of
Southwestern Montana, though we will have to watch for some
isolated strong winds thanks to storm bases reaching 7-8000 feet
above the valley floors.

Extended (Sunday though next Friday)...Aside from a few rain and
mountain top snow showers on Sunday, The second half of the
Memorial Day weekend will feature mostly dry and warm weather for
all of the Memorial Day activities that are scheduled for the
weekend as an upper level ridge builds into the area. After highs
on Sunday remaining in the 60s across the lower elevations across
the area, highs for Memorial Day will reach into the 70s with a
few locations toying with 80 on Tuesday.

Our next system looks to push in Tuesday night or Wednesday,
which will bring a potential for widespread thunderstorms followed
by cooler temperatures. Not much is known about the details of
this system yet aside from the potential for thunderstorms and
cooler weather, however, as ensemble guidance from the WPC Cluster
Analysis shows that models diverge strongly and rapidly beyond
the middle of next week. Ludwig

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  40  65  41  63 /  10  70  40  10
CTB  37  62  40  60 /  20  30  10  10
HLN  43  65  41  64 /   0  70  40  10
BZN  35  63  37  62 /  20  80  80  20
WYS  30  54  33  54 /  10  80  80  20
DLN  36  59  34  62 /  10  70  40   0
HVR  40  69  44  64 /  40  40  50  30
LWT  37  63  38  59 /  10  70  70  20

&&

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

$$

http://www.weather.gov/greatfalls