764
FXUS65 KTFX 301944
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
144 PM MDT Sun Jun 30 2024

.SYNOPSIS...

Strong to severe thunderstorms will be around across eastern
portions of Southwest through Central Montana this afternoon and
evening. Thereafter, the upcoming week looks to be on the cooler
side of average, with daily opportunities for showers and
thunderstorms through July 4th. Looking toward this weekend,
warmer and drier conditions are favored.

&&

.DISCUSSION...

The rest of today and tonight... The leading wave within an
approaching upper level trough is passing across the region this
afternoon. This wave has helped initiate showers and thunderstorms
near Monida Pass that will shift northeastward through the
evening. Relatively deep inverted-V soundings, modest instability,
and long straight hodographs will foster a strong wind gust and
hail threat, though the former is the main concern today. These
showers and thunderstorms exit eastern portions of Central Montana
this evening.

Although the most favorable area for ascent will exit eastward
tonight, the broad upper trough across the region will still allow
for showers and thunderstorms to develop across Southwest Montana
tonight, with impacts being much more limited.

Monday... The broad troughing will remain in place across the
northern Rockies, allowing for scattered showers and thunderstorms,
mainly in the afternoon and evening. At this point, these
thunderstorms look to be more of a run-of-the-mill variety. -AM

Tuesday through the 4th of July...Expect a slow cooling trend for
temperatures during this period, with the 4th of July looking like
the coolest day for most areas. The airmass will remain unstable,
with daily chances for showers/thunderstorms, especially for areas
north of I-90 from Butte to Bozeman. At this time, it looks like the
showers/storms will exit much of the CWA by late in the afternoon on
July 4th, resulting in mostly dry conditions for the 4th of July
evening hours. Overall, the threat for any severe storms early next
week looks to be less than 10 percent.

Friday through Sunday...The GFS and EC differ in terms of how strong
an upper level trof will be over MT for next weekend. Right now
there is only about a 20 percent chance from the cluster analysis
that the GFS is right. Thus, I will continue to use the warmer and
drier NBM solution for next weekend, as there is an 80 percent
chance for this solution to pan out. Brusda

&&

.AVIATION...
30/18Z TAF Period

Since the last round of TAFs KLWT, KBZN, and KEKS are now included
in the slight risk for severe weather. The main concern will be for
severe wind gusts, particularly for KLWT. The main timeframe for
severe weather will be from 30/20Z to 01/00Z with MVFR/IFR
conditions and mountain obscuration expected around thunderstorms.
For both KBZN and KEKS there is around 10% chance of dipping into
LIFR conditions with heavier thunderstorms. However, confidence was
not high enough to add it to the TAFs.

Otherwise for all other sites scattered showers and thunderstorms
will be moving across the area this afternoon with the main threat
being gusty and erratic winds near stronger storms. Flight
conditions will generally remain VFR with some periods of MVFR
possible this afternoon.

Showers and thunderstorms will exit the area after sunset allowing
for calmer conditions to return to all sites.

-thor

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  53  76  52  75 /  30  30  40  50
CTB  51  71  50  73 /  10  60  30  60
HLN  54  79  54  81 /  50  30  30  30
BZN  50  74  47  76 /  60  60  60  20
WYS  44  65  37  67 /  50  80  80  20
DLN  48  71  43  73 /  60  60  40   0
HVR  55  76  54  77 /  30  40  30  70
LWT  50  72  48  71 /  80  20  20  70

&&

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

$$

http://www.weather.gov/greatfalls