230
FXUS65 KTFX 152203
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
403 PM MDT Thu Aug 15 2024

.SYNOPSIS...

Showers and thunderstorms will lift northward across the region this
afternoon and evening. Additional showers and thunderstorms will be
around at times Friday into the weekend, with temperatures largely
near normal through the upcoming week.

&&

.DISCUSSION...

Key Points:

-A few showers and thunderstorms this afternoon and Friday
afternoon, some of which may cause gusty winds

-Near to slightly below average temperatures expected through
the first half of next week

Short term (through Friday)... As an upper level trough moves
into the area from the Pacific Northwest this afternoon and
evening, a few showers and thunderstorms have begun to develop,
mostly over the higher terrain. Expect these showers and
thunderstorms to gradually grow and become detached from the
higher terrain by mid to late afternoon, especially south and west
of a line from Cut Bank to Great Falls to White Sulphur Springs.
While most of these showers and storms should be run of the mill
cells, a few of the storms may be able to produce some gusty winds
to 50 mph, mainly south of I-90 on the east side of the divide.
Showers and thunderstorms will move northeastward overnight and
for the day on Friday, resulting in scattered showers and
thunderstorms across the plains, though any location will be
unlikely to see rain last for an extended period of time. Like
today, a few of the storms may be able to produce a few isolated
wind gusts to 40-50 mph, but severe storms are not expected to be
a major concern. Ludwig

Saturday through Thursday...An upper level ridge will try to
build over the CWA over the weekend, but our CWA will generally be
in the southwesterly flow of the ridge. This will allow for
warmer air to move into the CWA over the weekend and into early
next week. It will also allow for weak upper level disturbances to
move northeastward through the CWA producing a few
showers/thunderstorms. With afternoon temperatures
approaching/slight above 90 degrees by early next week, there will
be enough instability that a few strong storms will be possible,
however, the dynamics are fairly weak so widespread severe weather
is unlikely at this time. By late next week afternoon
temperatures are progged to start to cool down a few degrees, as
the upper level ridge starts to move off to our east. Brusda

&&

.AVIATION...
15/18Z TAF Period

At all terminals, excluding the KWYS terminal, VFR conditions will
prevail during this TAF period, except during thunderstorms. There
are IFR-level ceilings at the KWYS terminal which will gradually
improve to VFR-levels by 00Z. From 22Z to 00Z there is a 40% chance
for thunderstorms at the KEKS land KWYS terminals. From 00Z through
12Z there is a 50 - 70% chance for showers and thunderstorms at all
terminals excluding the KHVR and KLWT terminals. During any
thunderstorm that affects a terminal visibility will be reduced to
MVFR-levels. Thunderstorms will produce gusty erratic winds,
frequent lightning, and brief heavy rainfall. During thunderstorms
there will be mountain obscuration. There is a 20% chance between 10
and 14Z for fog at the KBZN and KEKS terminals. There will be fog at
the KWYS terminal between 10Z and 14Z reducing visibility to at
least low IFR-levels. At the KGTF, KCTB, KHVR, and KLWT terminals
there is a 40% chance for showers from 12Z through at least the end
of the TAF period. During most of this TAF period there will be
mountain obscuration around the KWYS terminal. -IG

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  84  57  81  53 /   0  50  60  20
CTB  82  54  74  48 /  10  60  80  20
HLN  85  55  83  54 /  10  60  40  30
BZN  83  48  83  48 /  10  60  20  30
WYS  75  38  73  36 /  20  70  10  10
DLN  78  46  78  45 /  60  60  10  10
HVR  87  58  84  55 /   0  10  50  60
LWT  81  54  80  50 /  10  20  60  30

&&

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

$$

http://www.weather.gov/greatfalls