778
FXUS65 KTFX 051612
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1012 AM MDT Sat Jul 5 2025

.KEY MESSAGES...

 - Another round of showers and thunderstorms are expected today
   with isolated severe thunderstorms possible in portions of
   central Montana.

 - Temperatures will slowly warm up heading into next week with
   drier conditions expected to persist after today.

&&

.UPDATE...

Surface observations this morning show dew points in the upper 40s
to mid 50s across much of the region in wake of precipitation
yesterday. Although this surface moisture looks to decrease a bit as
daytime mixing ensues (But maintain over the eastern plains),
slightly cooler temperatures aloft and forcing from an
approaching trough moving across the region this afternoon will
result in another round of showers and thunderstorms.

The risk for stronger thunderstorms today largely appears to be
confined to areas on the eastern plains, where the greatest
instability overlaps with favorable kinematics. Large hail has
trended to be the greatest threat today in recent guidance given
relatively straight and long forecast hodographs. Given surface
moisture in place, mixing isn`t overly deep. Hence, strong wind gusts
do not appear to be an immediate risk from thunderstorms that form.
As storms move east and outside of the forecast area, the threat for
strong wind gusts appears to increase as congealing of thunderstorms
occurs.

The forecast was updated to reflect ongoing trends. -AM

&&

.DISCUSSION...
/Issued 514 AM MDT Sat Jul 5 2025/

 - Meteorological Overview:

Cool and wet conditions will linger through today as the low
pressure system continues its march east. Morning stratiform rain
will transition into more convective showers by the afternoon. A
few storms, particularly in Fergus county, may turn severe this
afternoon with the main threat being strong winds.

Behind the departing low, northwest flow sets up on Sunday allowing
temperatures to start moderating back to normal through Monday.
Weak upper level ridging builds over the state through the
middle of the work week, allowing temperatures to warm back into
the upper 80s to mid 90s Tuesday and Wednesday. Generally dry
conditions will persist through much of the week, however, an
isolated afternoon thunderstorm cannot be ruled out, particularly
over higher terrain.

A weak shortwave is expected to pass through Thursday through
Friday which will bring temperatures back down to normal and
introduce a chance for isolated afternoon thunderstorms,
especially along higher terrain. In its wake quasi-zonal flow sets
up which will slowly allow the region to warm back up and enter
another dry period by next weekend.


 - Forecast Confidence & Scenarios:

Thunderstorms Today:

Evaluating the latest HREF, the first thing that becomes quite
clear is the most significant risk for severe weather is east of our
area. Which is not to say that severe weather is off the table for
us. Rather the greatest threat will be any thunderstorm that
kicks off in the early to mid afternoon before heading east
towards the southeastern portion of the state. The main concern
will be wind gusts in the 40-50 mph range with some isolated
higher gusts, small hail (<0.50"), and a potential for cold air
funnels. Time-wise, the greatest threat will be between 2 PM and
6 PM and the areas to watch will be Fergus, Judith Basin, and
Meagher counties.

In general, rainfall totals will be on the lower side Saturday
afternoon with hit-or-miss higher amounts around stronger
thunderstorms. After today, we enter a warmer and dry period with
very little accumulation expected over the upcoming week. -thor


&&

.AVIATION...
05/12Z TAF Period

Light winds, clear skies, and recent precipitation will continue
to maintain the risk for IFR/MVFR conditions due to fog/mist at
the KWYS, KBZN, and KHLN terminals through 15z this morning;
thereafter increasing heating will help to decrease the threat.

Showers and thunderstorms, which are ongoing this morning along
the Continental Divide, will increase in areal coverage beyond
15-18z Saturday across the remainder of the Northern Rockies and
persist through 03-06z Sunday. While VFR conditions will
predominately prevail beneath the shower and thunderstorm activity
there remains the potential for temporary periods of MVFR
conditions, mainly due to reduced VIS beneath heavier burst of
precipitation. Main concern with thunderstorm activity during the
afternoon hours today will be gusty and erratic winds, generally
along and east of a KEKS, to KBZN, to KLWT line. Mountains,
especially those above 9kft, will be obscured through 06-09z
Sunday. - Moldan

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  75  50  81  52 /  60  20   0   0
CTB  65  46  75  47 /  70  10   0   0
HLN  74  51  82  53 /  60  20   0   0
BZN  76  45  82  49 /  70  30   0   0
WYS  71  35  75  36 /  50  20   0   0
DLN  74  43  79  46 /  50  10   0   0
HVR  77  50  82  52 /  70  40  10  10
LWT  72  47  75  49 /  80  40   0  10

&&

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

$$
http://www.weather.gov/greatfalls