375
FXUS65 KTFX 062058
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
258 PM MDT Sat Jul 6 2024

.SYNOPSIS...

Scattered showers and thunderstorms diminish in coverage this
evening and tonight. High pressure begins to build in on Sunday
for warmer and drier conditions. The warming trend significantly
increases next week with an extended period of very warm to hot
temperatures expected through at least the weekend.

&&

.DISCUSSION...

Remainder of this afternoon through Sunday night...Showers and
embedded thunderstorms from this morning have mostly moved east of
the CWA, but a more scattered variety of showers and storms will
continue to fire up over Central/North-central MT and southwestern
locations mostly north of I90 with the assistance of weak
perturbations within the northwesterly flow aloft and diurnal
heating. Although ML CAPE levels are approaching and exceeding 500
J/kg in spots, bulk shear mostly less than 20 kts will limit
storm strength and temporal longevity. Regardless, even general
thunderstorms such as these may produce gusty and erratic winds,
small hail, and brief downpours in addition to lightning. Most
showers and storms diminish and end this evening, but a few
lighter showers may linger into the overnight hours. - RCG

The building upper level ridge begins to nudge eastward Sunday,
though northwesterly flow will persist for one more day across the
region. There doesn`t look to be any embedded waves diving
southeastward through this flow however, so chances for showers
and thunderstorms look to decrease quite a bit. Given lingering
moisture and marginally cool temperatures aloft remaining in
place, showers and an isolated thunderstorm or two will remain in
the forecast on Sunday, particularly over over higher terrain.

Monday through next weekend...The aforementioned upper level
ridge will continue to slowly shift eastward, inland across the
western CONUS Monday into the middle of next week. A warming trend
will commence as a result, with temperatures pushing well into
the 90`s at lower elevations by Wednesday. The brute of the heat
looks to peak around Thursday, but an increasing share of longer
range ensemble members favor well above average temperatures
persisting into at least next weekend. - AM

&&

.AVIATION...
06/18Z TAF Period

Showers/isolated thunderstorms will continue to push off to the
east, mainly impacting the KLWT terminal for the next few hours.
Showers/isolated thunderstorms redevelop this afternoon with a 10-
30% of thunderstorms. However, storms will be hit or miss at
terminals, and there`s less confidence to pinpointing the exact
timing of these storms. Therefore, I`ve kept out the mention of
thunder in the TAFs. If confidence increases of thunder affecting
terminals later this afternoon, then an amendment will be issued.
Brief gusty winds, lightning, and small hail will be a threat to
thunderstorms that form. Isolated pockets of heavier rainfall can
bring brief MVFR visibilities to terminals. -Wilson

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

&&

.PREV DISCUSSION...
/ISSUED 1145 AM MDT Sat Jul 6 2024/
FXUS65 KTFX 061745
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1145 AM MDT Sat Jul 6 2024

..Aviation Section Updated...

SYNOPSIS...

Cooler than average temperatures persist for most areas through
Sunday. Showers and thunderstorms will be around again today, and to
a lesser extent tomorrow before a warming and drying trend commences
Monday. Hot temperatures look to last through the week and into
next weekend, with the only uncertainty related to exactly how hot
it will get.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  50  82  55  88 /  10  10   0   0
CTB  49  83  52  88 /  10  10   0   0
HLN  55  87  58  92 /  20   0   0   0
BZN  48  80  51  87 /  20  20   0   0
WYS  38  75  38  80 /  10  20   0   0
DLN  46  79  49  86 /  10   0   0   0
HVR  53  82  55  90 /  20  20   0   0
LWT  47  74  50  83 /  20  20   0   0

&&

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

$$

http://www.weather.gov/greatfalls