Shelby, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

051
FXUS65 KTFX 151736
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1120 AM MDT Fri Aug 15 2025

Updated Aviation Discussion

.KEY MESSAGES...

 - Dry and breezy weather today will lead to elevated fire
   weather conditions, especially across Southwestern Montana.
 - Building upper level ridging across the Western US will bring
   increasingly warm and dry conditions to the area next week
 - A mix of wet and dry thunderstorms is expected on Saturday and
   Sunday

&&

.UPDATE...

Dry air at the surface today will keep the region mostly dry.
However, a weak upper-level wave passing through this afternoon
with enough mid-level moisture can produce a few light isolated
showers or a thunderstorm in North-Central and Southwest MT.
Little precipitation is expected with any shower that pops up this
afternoon. -Wilson

&&

.DISCUSSION...
/Issued 536 AM MDT Fri Aug 15 2025/

 - Meteorological Overview:

With dry and warm southwesterly flow aloft in place, expect
another warm, dry, and slightly breezy day across North Central
and Southwestern Montana today. While temperatures will be similar
to what they were yesterday across Southwestern Montana, expect
temperatures to be around 10 degrees warmer than yesterday across
the Plains as the shallow layer of cooler air erodes away quickly
under the influence of clear skies and the southwesterly flow
aloft. While the upper level pattern will remain fairly consistent
through the weekend, a plume of moisture aloft will help to spur
the development of a few showers and thunderstorms over the
weekend. While a few of the storms could bring some beneficial
rainfall to some isolated areas, dry air near the surface will
likely keep the storms relatively dry and could lead to some new
fire starts next week.

Upper level ridging will retrograde westward early next week,
moving from the Central US Plains to the Great Basin/Desert
Southwest early next week, which will help nudge temperatures
upward while keeping our weather largely dry.

- Forecast Confidence & Scenarios

As southwesterly flow aloft brings in a plume of moisture over the
weekend, expect a few showers and thunderstorms to develop across
mainly Southwestern Montana during the afternoon and evening
hours. While moisture will be abundant in the mid and upper
levels, current model soundings show a deeply mixed and very dry
boundary layer at the surface, which is likely to keep
precipitation isolated to directly under the thunderstorm cores.
With that said, model soundings also show a tall and skinny
instability profile, which are notorious for producing localized
heavy rains. These factors, combined with weak steering flows
aloft, may result in storms moving very slowly, which could lead
to some flooding, particularly if a thunderstorm moves over a burn
scar such as the Horse Gulch or an actively burning fire. While
flooding appears unlikely at this point, there are enough
atmospheric signs that it is possible in the right scenario to
mention in the AFD. Ludwig&&

&&

.AVIATION...
15/18Z TAF Period

A dry west to southwesterly flow aloft continues across the Northern
Rockies and MT with predominantly VFR conditions at all terminals
through the period. Expect some cumulus development this afternoon
as well as an influx of some higher level clouds from the west going
into this evening. An isolated thunderstorm or two cannot be ruled
out across portions of north-central and southwest MT through early
this evening, but probabilities are around 10% or less at most TAF
sites. Breezy winds are expected to develop this afternoon and
diminish this evening.

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

&&

.FIRE WEATHER...

Elevated to near critical fire weather conditions are expected
across Southwestern Montana this afternoon as critically low RH
values in the teens combine with occasional wind gusts to 20 to 25
mph through this evening. Some improvement is expected through
the weekend with slight moderation in temperatures there along
with less windy conditions, however breezy afternoon winds and low
humidity will maintain an elevated fire weather risk. In addition,
a few wet and dry thunderstorms will be possible, which could
result in new fire starts over the weekend. Hoenisch/Ludwig


&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  88  57  91  59 /  10  10   0  20
CTB  80  54  83  55 /  20  10   0  10
HLN  89  57  90  59 /   0   0  10  20
BZN  91  53  91  53 /   0  10  10  20
WYS  82  42  81  42 /   0   0  20  20
DLN  88  49  86  51 /  10  10  10  10
HVR  85  57  91  59 /  20  20   0  20
LWT  83  56  88  56 /  10  10  10  30

&&

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

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