089 
FXUS65 KPIH 030745
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
145 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

Precip looks to linger across the region for much of the day on 
Saturday as the low moves across northern Utah and into western 
Wyoming. Expecting widespread precip for Saturday with daytime highs 
likely only topping out in the 40s and low to mid 50s, at best, 
regionwide. 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 /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 855 PM MDT Thu Oct 2 2025

No major changes to the aviation forecast at this time. Showers 
continue to move into Central Idaho tonight, very near to KSUN where 
VCSH will remain in the forecast. The rest of our sites are expected 
to remain dry tonight. There is low confidence in some gusty winds 
around 25 kts as showers pass near SUN tonight. As moisture 
continues moving into Eastern Idaho, models suggest the development 
of some low stratus around BYI, PIH, and IDA early Friday morning 
with about a 20 to 30 percent chance of MVFR CIGs. As such, have FEW 
to SCT MVFR clouds, but no predominant MVFR CIGs. Showers and 
an isolated storm or two may not reach the Snake River Plain 
until Friday afternoon, before coverage increases Friday night 
into Saturday.

&&

.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...AMM
FIRE WEATHER...13