703
FXUS65 KTFX 291432
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
832 AM MDT Fri Aug 29 2025

.KEY MESSAGES...

- Scattered showers and isolated thunderstorms over much of
  Central and North Central MT today, along with cool
  temperatures.

- Other than a few showers east of a Havre to Stanford line on
  Saturday, it should be mostly dry and seasonable.

- It turns warmer, along with lower humidity for Sunday and
  Monday.

&&

.UPDATE...

Patchy dense fog is around Belgrade and Raynolds pass. This fog
will gradually clear up over the course of the next couple of
hours. Today it will be cool with rain showers across North-
central and Central Montana. This afternoon there could also be a
rumble of thunder as well across North-central and Central
Montana. For the update, minimum relative humidity was increased
across North-central, Central, and Southwestern Montana to better
reflect current observations and trends. PoPs across North-central
and Central Montana this evening were adjusted to better reflect
the latest hi-res model guidance. The rest of the forecast is on
track. -IG


&&

.DISCUSSION...
/Issued 400 AM MDT Fri Aug 29 2025/

 - Meteorological Overview:
An upper level disturbance is trying to move eastward across the
northern portions of MT today. This will result in scattered
showers and isolated thunderstorms today. Patchy morning fog will
also impacts parts of the CWA as well. Expect one more day with
afternoon temperatures not quite as warm as they have been, along
with higher humidity. On Saturday, the upper level disturbance
moves east and slowly dissipates. Thus any showers will mainly be
over the eastern portions of the CWA, generally east of a Havre to
Stanford line.

For Sunday and Monday...a return to mostly dry and warm
temperatures is expected. Afternoon temperatures will be near 90
degrees once again.

For Tuesday through next Friday...an upper level ridge of high
pressure will generally reside just to our west during this
period. This would result in dry and warm conditions for much of
next week. There is some potential that a weak cold front could
slide southward from Canada and slide through the eastern portions
of the CWA, mainly from Wed thru Thu. This front could produce a
few isolated showers/thunderstorms, mostly over the eastern
portions of the CWA.

 - Forecast Confidence & Scenarios:
The main concern today will be the potential for an isolated storm
to produce heavy rainfall. High dew points and a bit more
instability today gives a 5 percent chance of that potential.
Brusda

&&

.AVIATION...
29/12Z TAF Period.

Main concern this morning will be the potential for fog/low ceilings
in any areas that have some clearing. Southwest MT is the most
favored area for fog, where LIFR visibility is possible for a few
hours. Otherwise, showers/isolated thunderstorms are expected once
again today, with North Central MT the most favored area for
precipitation. Mountains/passes will be obscured at times across the
CWA by morning fog and low clouds. Brusda

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

&&

.HYDROLOGY...
There is still a small chance that a stronger thunderstorm could
produce some heavy rainfall in a short time today. The probability
is low, generally less than 5 percent, with the highest
probability in the Stanford, Lewistown and White Sulphur Springs
area. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  74  52  84  53 /  70  50  10  10
CTB  71  48  83  51 /  50  30   0  10
HLN  77  54  83  54 /  60  30  10  10
BZN  77  49  80  48 /  30  20  10  10
WYS  71  37  72  36 /  20  10  10  10
DLN  76  45  78  45 /  10  10   0   0
HVR  71  54  81  53 /  70  50  20  10
LWT  69  51  76  53 /  80  50  20  20

&&

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

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