Cascade, Montana Weather Forecast Discussion

532
FXUS65 KTFX 130220
AFDTFX
Area Forecast Discussion
National Weather Service Great Falls MT
820 PM MDT Fri Sep 12 2025
.KEY MESSAGES...
- Scattered showers and thunderstorms will continue across
   north-central and central Montana through the evening.
- Above normal temperatures and daily chances for showers and
   thunderstorms will continue through the weekend.
&&
.UPDATE...
Satellite imagery this evening shows the upper level trough axis
oriented from southern AB to central ID with smaller scale
waves/vort features embedded. Scattered showers and a few
thunderstorms are ongoing this evening but are gradually
decreasing in coverage/intensity, which should continue as the
airmass further stabilizes. The risk for stronger storms and
excessive precipitation has decreased but slow movement and
locally higher precipitation rates could still create some
standing/ponding of water, particularly with somewhat more intense
cells still across the Golden Triangle area. Partial clearing
overnight could lead to some areas of fog development,
particularly across portions of north-central MT that saw more
substantial precipitation from storms earlier today. Hoenisch
&&
.DISCUSSION...
/Issued 455 PM MDT Fri Sep 12 2025/
- Meteorological Overview:
Thunderstorms are already underway across portions of central and
north-central Montana with the strongest storms expected in Judith
Basin, Fergus, and Blaine counties. The latest CAMs show MLCAPE in
the 1500-2000 J/kg range which is more than sufficient to kick of
stronger storms. Due to a lack of shear, these storms are quasi-
stationary at the moment which may become a concern for localized
flash flooding under stronger cells.
An active pattern will continue through the weekend with daily
chances for showers and thunderstorms across the region. Above
normal temperatures will persist across north-central and central
Montana with more seasonably temperatures expected across
southwest Montana.
- Forecast Confidence & Scenarios:
Right now the main concern are the storms firing off of the Little
Belt and Bears Paw mountains. Some gusty winds, generally less
than 40 mph, are expected along with small hail. There is a
concern that a couple of these thunderstorms may get stronger and
produce locally stronger wind gusts up to 50 mph and larger hail
up to 1 inch. At this time, widespread severe weather is not
expected with the biggest threat for severe thunderstorms off to
the east of our area.
Otherwise the primary concern is how slow these storms are
moving. Quite a few of the storms that have developed have storm
motions of 5 to 10 mph which is expected given the lack of shear
but it also means that the threat for flooding starts to slowly
tick up the longer these storms stall over one area. For now,
there is low confidence (

NWS TFX Office Area Forecast Discussion