Craters Of The Moon National Monument, Idaho Weather Forecast Discussion

190
FXUS65 KPIH 031005
AFDPIH
Area Forecast Discussion
National Weather Service Pocatello ID
405 AM MDT Fri Oct 3 2025
.KEY MESSAGES...
- Cold front arrives today and tonight bringing increasing rain
  chances and cooling temperatures for parts of the area
- Showers, storms and much colder temperatures for the weekend
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 144 AM MDT Fri Oct 3 2025
A low pressure system will move through northern Nevada today while
a slow moving cold front moves into southwest Idaho. A band of heavy
rain and embedded thunderstorms will continue to pass through the
Sawtooth region today. Additional rainfall amounts in that area of
0.25 inches are likely today with most of that falling this morning.
A flash flood watch continue for the Wapiti burn scar. Otherwise
most of central and east Idaho will be dry until afternoon. Models
are showing some strong thunderstorms developing across south Idaho
late this afternoon and this evening as upper level dynamics become
more favorable for lift. Gusty outflow winds and marginally severe
hail are the main threat late this afternoon and evening across
south central and east Idaho. Showers will become more widespread
across central and east Idaho tonight as the low moves over southern
Idaho and northern Utah. Rainfall amounts tonight for the south
central and eastern Idaho up to 0.25 inches are likely. Although
rainfall amounts are highly dependent on where the storms pass
through. For example, there`s a 10% chance of little to no rainfall
and a 10% chance of 0.50 inches. So, tonight could be a bit of a
feast or famine type of rainfall.
On Saturday, the low will move east into Wyoming. Colder air will be
moving into the region behind the low and we will see some light
high elevation snow (above 9000 feet) across the central mountains.
Additional rainfall amounts on Saturday will range from around 0.10
inches in the central mountains and Magic Valley to around 0.25
inches across the Snake Plain to as much as 0.50 inches for the
eastern highlands. Once again, rainfall amounts are still very
dependent upon where the stronger showers set up with models still
showing 10% chances of very little moisture and 10% chance of an
additional 0.25 inches on top of the amounts quoted. Highs on
Saturday will struggle to get into the 50s across the region.
On Saturday night, a secondary weak system will pass through our
region. This will keep continued chances for light rain showers
going through the night. Although additional rainfall amounts should
be light, ranging from a few hundredths across the Magic Valley to
0.10 inches or so for east Idaho. Additional light snow looks likely
for high elevations of the central mountains and around the
Montana/Wyoming border. Probably above 7500 feet or so. Frost/freeze
headlines look unlikely at this point for Saturday night as the
cloud cover and precipitation will likely keep temperatures up just
enough in the Snake Plain and Magic Valley. Although some of the
high country communities could see lower 30s.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 237 PM MDT Thu Oct 2 2025
The region will reside in a broad upper trough across the
Pacific NW throughout the weekend so even as the low moves into
Wyoming on Sunday, we will likely still see some wrap-around
precip across the eastern half of the region with continued
cooler than normal temps with continued temps in the 40s and 50s
for our daytime highs on Sunday. Upper level troughing will
give way to weak ridging building back over the region for the
start of the workweek. This will allow temps to start on an
slow,upward trajectory for the workweek next week. Things will
run on the cooler side of normal, but still generally pleasant,
with a fair amount of sunshine expected. A few weak upper level
shortwaves may swing through the region during the week which
could bring some clouds and maybe an isolated precip chance
across the higher terrain but things look dry for much of
eastern Idaho next week. Perhaps things become more active as we
get closer towards next weekend but this far out in time,
confidence isn`t too high. We`ll see how things trends over the
coming days.
&&
.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 404 AM MDT Fri Oct 3 2025
A surface boundary blew through during the overnight
hours. Gusty winds accompanied the boundary along with low ceilings.
Already seeing signs that the low ceilings are breaking up around
BYI and HRRR/NBM seems to indicate that we`ll see these ceilings
break up around 16Z elsewhere. Biggest impact is at SUN where the
winds turned upvalley helping to drag these low clouds into SUN.
Guidance indicates that SUN will remain upvalley through the day and
that the ceilings should break up mid to late morning there as well.
Expect wind gusts at all TAF sites to diminish around mid morning as
well. Next problem is timing if storms develop this afternoon with
high resolution models offering very little run to run consistency.
Compelled to include PROB30s at most TAF sites, did leave it out of
SUN with the feeling that most of the activity will be east of
there. Although not overly confident in that decision.
&&
.FIRE WEATHER...
Issued at 144 AM MDT Fri Oct 3 2025
A slow moving low pressure system will bring wetting
rains to the region through Saturday. An additional 0.25 to 0.50
inches is likely across central and south Idaho fire districts while
east Idaho will most likely see 0.50 to 1.00 inches through 12z
Sunday. Along with the rainfall, much cooler temperatures and higher
humidity will arrive. Some high elevation light snow is also likely.
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...13
LONG TERM...McKaughan
AVIATION...13
FIRE WEATHER...13

NWS PIH Office Area Forecast Discussion