Malmstrom AFB, Montana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

231
FXUS65 KTFX 111147
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
547 AM MDT Wed Jun 11 2025

Aviation Section Updated.

.KEY MESSAGES...

- Another round of showers and thunderstorms move from south
  to north this afternoon and evening with a few stronger storms
  capable of producing localized strong winds over 50 mph, brief
  heavy downpours, and hail.

- There will be a period of general rain and embedded
  thunderstorms over Central and North-central Montana tonight
  into Thursday.

- Clouds and precipitation will cool temperatures closer to
  average today and on Thursday.

- Slightly above average temperatures and daily showers
  and thunderstorms are expected heading into the weekend, with
  some storms on the stronger side.

&&

.DISCUSSION...
/Issued 356 AM MDT Wed Jun 11 2025/

 - Meteorological Overview:

Showers and thunderstorms over the Central Montana have
diminished, but will continue along the Hi-Line of Hill and Blaine
counties through mid- morning thanks to a weak perturbation
within the westerly flow aloft. Another area of showers and
thunderstorms, associated with a stronger shortwave, moves into
Southwestern Montana later this morning before heading into
Central and North- central Montana this afternoon and evening.
Although wind shear will be on the lower side, precipitable water
values between 0.75 and 1 inch and CAPE in the 600 to 1,200 J/kg
range will be sufficient for a few stronger storms with localized
wind gusts over 50 mph, brief heavy downpours, and marginally
severe hail (0.25 to 1 inch in diameter).

As the shortwave lifts northeastward tonight into Thursday, a
closed low begins to develop with the showers and thunderstorms
over Central and North-central Montana transitioning to more of an
area of general rain and embedded thunderstorms. Low level east
to northeasterly flow will also work to maintain periods of light
to moderate rain. The heaviest precipitation will be over the
northerly/easterly upslope areas along the Rocky Mountain Front
and the Central Montana island ranges where probabilistic guidance
supports rainfall totals in the 0.25 to 1 inch mark through
Thursday afternoon. The clouds and precipitation will cool
temperatures closer to average, coolest on Thursday.

Southwesterly flow aloft strengthens heading towards the weekend
and early next week all while CAPE and precipitable water values
more or less remain roughly similar to those of previous days. The
additional shear will increase overall storm intensity and
lifespan. - RCG

 - Forecast Confidence & Scenarios:

Stronger showers and thunderstorms today and this weekend...

Showers and thunderstorms will be most concentrated over the
southwest this morning into the early afternoon hours before
moving northward into Central/North-central Montana later in the
afternoon and evening. The areas with the highest CAPE values will
be south of a weak frontal boundary situated just south of the
Hi-Line. Slightly cooler temperatures today does work against
stronger storm development, but increased moisture should make up
the difference. Localized wind gusts over 50 mph, brief heavy
downpours, and marginally severe hail (0.25 to 1 inch in diameter)
will be the primary hazards in addition to lightning. Improved
shear does increase storm intensity and storm life cycle Friday
through early next week. Friday and Saturday look to be the
busiest days as of right now, but this will be dependent on the
timing of shortwaves and frontal boundaries.

Rain over Central and North-central Montana tonight into
Thursday...

A closed looks to develop over Central and Eastern Montana
tonight into Thursday which will work to maintain areas of rain
and embedded thunderstorms over the plains and the
northern/eastern slopes of the Rocky Mountain Front and the
Central Montana island ranges. Probabilistic guidance supports
rainfall totals between 0.25 and 1 inch in these areas with a 40
to 80% chance for a half inch or more of rainfall, highest over
Central Montana island ranges and their northerly foothills.
Localized areas may see amounts exceeding an inch, particularly
areas that are hit localized heavier downpours from thunderstorms
earlier in the day. Flooding is generally not expected, but those
outdoors near waterways and or low lying areas should be aware of
their surroundings. - RCG

&&

.AVIATION...
11/12Z TAF Period

Variable cloudiness today with showers and thunderstorms
northeast of KHVR is expected to persist through 11/18Z. Another
round of showers and thunderstorms is currently moving into far
Southwest Montana and will continue to move north and eastward
through the southwest this morning and eventually Central and
North- central Montana this afternoon and evening. Localized wind
gusts over 40 kts, brief heavy downpours, and marginally severe
hail (0.25 to 1 inch in diameter) will be the primary hazards in
addition to lightning.

Low VFR or MVFR conditions can be expected during times
of precipitation this afternooon and evening. Degraded categories
will become more widespread tonight into Thursday morning due to
low clouds and or patchy fog in addition to rain. Also haze from
Canadian wildfire smoke will continue to impact KHVR over the next
24 hours and is expected to expand westward in KCTB this
afternoon and evening.- RCG

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  80  55  74  52 /  50  90  80  30
CTB  75  52  71  49 /  50  90  90  30
HLN  79  57  79  54 /  60  70  60  40
BZN  77  50  77  49 /  70  80  40  30
WYS  72  39  71  39 /  80  90  30  30
DLN  72  46  75  48 /  90  80  30  20
HVR  80  52  70  49 /  40  90  90  30
LWT  76  52  64  47 /  60  90  90  30

&&

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

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