987
FXUS65 KTFX 180557
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1157 PM MDT Wed Jul 17 2024

...AVIATION SECTION UPDATED...

.UPDATE...

Satellite imagery this evening shows mid to upper level moisture
being drawn north into the region and circulating around a mid
level feature centered across WA. This resulted in widely
scattered afternoon shower and thunderstorm development across
the area which is decreasing this evening but a few lingering
showers remain possible across primarily southwest MT, north along
the continental divide and across Glacier county. Showers and
thunderstorms currently closer to the mid level circulation across
eastern WA/OR may move into areas along the continental divide
north of Lincoln late tonight before crossing north-central MT
Thursday morning as the mid level feature lifts out across the
Northern Rockies. Have made some adjustments to pops through
Thursday morning to better align with current and upstream
precipitation trends but forecast is otherwise in good shape.
Hoenisch

&&

.SYNOPSIS...
Isolated thunderstorms are expected this evening, mostly south of
a line from Great Falls to Lewistown. On Thursday, expect a few
more thunderstorms during the afternoon and evening hours,
especially in the Havre and Lewistown areas. Otherwise, above
normal temperatures will continue through the upcoming weekend and
into next week.

&&

.AVIATION...
18/06Z TAF Period

Mid- and higher level clouds are expected to stream in tonight as a
shortwave disturbance approaches from the southwest. An initial wave
of light shower activity and perhaps a few embedded thunderstorms
will move through the Rocky Mountain Front and portions of
Central/North-central MT between 18/12 and 18/18Z. Then widely
scattered showers and thunderstorms are expected area wide Thursday
afternoon and evening. A few storms may be on the stronger side with
strong, gusty winds, lightning, and brief downpours. Hazy skies will
continue to impact slantwise visibility and hot afternoon
temperatures will impact density altitude. - RCG

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

&&

.FIRE WEATHER...
Isolated thunderstorms are expected this evening, while scattered
thunderstorms are expected on Thursday. Expect a mix of dry and
wet thunderstorms. The main concern from any storms will be gusty
outflow winds and lightning that occurs away from the parent
storms. Brusda

&&

.PREV DISCUSSION...
/ISSUED 545 PM MDT Wed Jul 17 2024/
Tonight through Thursday...Isolated thunderstorms are expected
through this evening, with a redevelopment of scattered
thunderstorms on Thursday. Some of the stronger storms will
produce gusty winds, hail and frequent lightning. An isolated
severe storm is also possible. Otherwise above normal temperatures
will continue.

For Friday through Wednesday, expect the trend of above normal
temperatures to continue. Overall, most lower elevation locations
will have afternoon highs ranging from the lower to upper 90s.
Little to no precipitation is expected for much of the early
portions of next week, as an upper level ridge will reside over
the CWA into the middle portion of next week. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  63  93  60  93 /  10  20  10   0
CTB  60  89  55  92 /  20  40  10   0
HLN  64  98  62  97 /  10  20  10  10
BZN  58  95  57  93 /  20  20  10  10
WYS  45  84  44  84 /  20  30  10  20
DLN  56  91  54  89 /  20  10   0  10
HVR  63  94  59  94 /  10  20  50  10
LWT  59  90  55  87 /  30  30  30  10

&&

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

$$

http://www.weather.gov/greatfalls