709
FXUS65 KTFX 050206
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
806 PM MDT Thu Jul 4 2024

.SYNOPSIS...

Scattered showers and thunderstorms will continue daily through
Saturday for north central Montana with drier conditions expected
south of interstate 90. Temperatures will stay cooler through
Saturday before warming up next week. Well above normal
temperatures and dry conditions are expected through much of next
week.

&&

.UPDATE...

Main update to the overnight forecast period was to increase
humidity where the heaviest rain fell over the plains late this
afternoon into the early evening. This has increased the chance
for fog mainly north and east of Great Falls in the more wind-
protected river valleys. Areas along the east slopes of the
Rockies did not receive as much precipitation and winds should
stay up enough to prevent fog formation there.

Otherwise, the showers and thunderstorms over the plains have
diminished quite a bit over the last couple of hours. Only
isolated showers and thunderstorms are lingering over Hill,
Blaine, Chouteau, Judith Basin, and Fergus Counties as of 8 pm,
and they should diminish through midnight with little additional
impact. -Coulston

&&

.AVIATION...
05/00Z TAF Period

VFR conditions are mostly forecast to continue through at least
06/00Z across North Central (KCTB, KHVR), Central (KLWT, KGTF,
KHLN), and Southwest (KBZN, KEKS, KWYS) Montana. However,
scattered showers and thunderstorms lingering over much of
Central Montana through around 03Z will keep a chance for brief
periods of MVFR conditions in heavier rain and small hail. Some
of these storms may also produce erratic wind gusts up to 35 kt
or so.

Partly cloudy skies will linger through the remainder of the
period with relatively light winds overnight. This may allow
patchy fog to form where heavier rain fell today, but confidence
is low that it will directly impact any of the terminals, so have
left mention out of the TAFs for now. The northwesterly flow
aloft will increase after 12Z, increasing the threat for mountain
wave turbulence. The airmass should become weakly unstable again
after 16Z, with the best chance for isolated to scattered showers
and thunderstorms mostly remaining over the plains east of a KCTB
to KGTF line. -Coulston

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

&&

.PREV DISCUSSION...
/ISSUED 530 PM MDT Thu Jul 4 2024/

Scattered showers and thunderstorms are expected on and off
through Saturday afternoon as northwesterly flow aloft continues
to bring moisture and instability into the region. In general,
these storms are expected to stay below severe limits, however,
some small hail and gusty winds up to 55 mph are possible with
stronger showers. Temperatures closer to normal will stick around
through the weekend before warming up early next week. -thor

Sunday through Thursday...A strong upper level ridge of high
pressure is forecast to move over MT during this period. This
will result in a significant heat wave to move into the CWA by
the middle portion of next week. Depending on how far east the
center of high pressure goes, will depend on exactly how hot it
gets. However, most models prog afternoon temperatures close to
at least 15 degrees above normal by Wednesday. Additionally, the
airmass will be very dry under this ridge, so no precipitation is
expected. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  49  77  53  76 /   0  20  10  20
CTB  46  77  50  75 /  10  10  20  20
HLN  52  83  56  83 /   0  10  10  30
BZN  45  79  48  79 /   0  10   0  20
WYS  34  73  37  75 /   0  10   0  20
DLN  43  79  46  81 /   0   0   0  10
HVR  50  78  52  77 /  10  40  20  30
LWT  46  72  48  71 /  10  40  20  50

&&

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

$$

http://www.weather.gov/greatfalls