313
FXUS65 KTFX 060002
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
602 PM MDT Sat Sep 5 2026

Aviation Section Updated.

.KEY MESSAGES...

- Showers and thunderstorms tonight and Sunday, become a more
  widespread rainfall Sunday night into Monday.

- An isolated severe storm possible Sunday.

- Cool temperatures to begin the week, with some warmer afternoon
  temperatures for a few days mid week.

&&

.DISCUSSION...
/Issued 244 PM MDT Sat Sep 5 2026/

 - Meteorological Overview:
A slow moving upper level low will remain to our west through
Sunday, before slowly moving eastward Sunday night into Monday.
Expect waves of showers/thunderstorms to move through the CWA from
now through Sunday afternoon. There is the potential that a few
storms could become severe on Sunday, thus much of the CWA is in a
marginal risk for severe storms. As the upper level low moves
eastward Sunday night into Monday, the showers will change more
into a stratiform rain, with the heaviest rainfall expected over
North Central MT. There is also a marginal risk for excessive
rainfall that could cause flash flooding Sunday night into Mon
over North Central MT.

Drier and warmer conditions develop mid week, with afternoon
temperatures close to 10 degrees above normal by Thursday. By next
Friday, another upper level trof will start to move southward into
the Pacific Northwest, resulting in a moist southwesterly flow
over Montana. Thus the chances for precipitation will start to
increase once again next Fri/Sat.

 - Forecast Confidence & Scenarios:
The main concern on Sunday for any severe storms will be strong
wind gusts. This system on Sunday will not be as strong as the
weather system that went through the CWA on Wednesday, never the
less, an isolated severe storm is possible. Additionally, some
storms could also produce heavy rainfall. By Monday night, the
northern portions of North Central MT could have received between
1 and 3 inches of rainfall, with isolated amounts near 4 inches
possible. Overall, flooding is not expected, but in areas that
exceed 3 inches, the probability of minor flooding on small
streams and creaks starts to increase. Brusda

&&

.AVIATION...
06/00Z TAF Period

VFR conditions are prevailing across the region currently however
lower ceilings are expected to develop tonight after 06/04Z primarily
impacting KGTF, KCTB, KHVR, and KLWT. IFR conditions will occur
generally from 10Z until 18Z with potentially LIFR at KCTB from
12Z to 15Z. Rainshowers and mist will also restrict visibility
over north and central MT from 06Z until 16Z. Secondary hazards
will be mountain obscuration due to clouds, rain, and mist as well
as icing in-cloud above FL100 along and 50 NM east of the Rocky
Mtn Front.


For KGTF: MVFR conditions for lower ceilings will develop by 07Z
and potentially becoming IFR temporarily from 11Z to 14Z. Some
uncertainty is present in the overnight low temperature and
dewpoint depression which will determine if ceilings become IFR or
LIFR for the morning. Low level northeast upsloping flow with
adequate moisture is present to persist these conditions until
late Sunday morning. - Akins

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  50  73  51  64 /  30  10  90 100
CTB  46  63  46  58 /  90  80  80  90
HLN  49  77  52  66 /  20  10  70  90
BZN  46  82  49  70 /   0   0  60  70
WYS  38  75  40  59 /   0   0  80  60
DLN  43  80  46  66 /   0   0  70  70
HVR  51  77  51  69 /  10  50  90 100
LWT  49  79  50  70 /   0  20  90  90

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
&&

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