Wildfire in Idaho, August 23 to 25, 2025

Area Forecast Discussion
National Weather Service Pocatello ID
429 PM MDT Sat Aug 23 2025

.KEY MESSAGES...

- Smoke from regional wildfires returns tonight into Sunday.

- Mostly hot and dry today with isolated storms farther south.
  Nearly a repeat on Sunday with a slight increase in isolated
  storm coverage.

- Monsoon moisture Monday through Thursday will bring scattered
  showers and storms daily, cooler temperatures, and measurable
  rainfall for many.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 124 PM MDT Sat Aug 23 2025

A check of satellite and radar early this afternoon shows a few
isolated showers and storms pinwheeling northeast around high
pressure in the Southwest and moving out of northeastern Nevada and
northwestern Utah into parts of southern Idaho. This will continue
this evening with these isolated storms mainly confined to parts of
the South Hills, but a few will likely make it into parts of the
Southeastern Highlands. Elsewhere, expect mostly dry conditions,
highs in the upper 80s to mid 90s, and wind gust of 15 to 25 mph.
This monsoon moisture will continue to increase through tonight and
Sunday will see an uptick in storms, but coverage in the South
Hills, Southeastern Highlands, and Central Mountains looks to remain
isolated. The increasing cloud cover on Sunday will help keep
temperatures just a few degrees cooler on Sunday and wind gusts will
remain in the 15 to 25 mph range.

Smoke from regional wildfires looks to filter back into parts of
Eastern Idaho a bit more tonight and into Sunday. While it will
likely be noticeable for all, an increased amount looks most likely
in parts of the Central Mountains. At this point, air quality
impacts look limited, but drops into the "Moderate" or briefly even
into the "Unhealthy for Sensitive Groups" would not be a big
surprise, particularly up around the Stanley and Challis areas.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 124 PM MDT Sat Aug 23 2025

Still on track for a prolonged period of clouds and rain across the
region, beginning as early as Monday for most locations. Those areas
that don't see rain on Monday will almost certainly see some Tuesday
and Wednesday with rain chances regionwide in the 70-90 percent
range for those two days. When was the last time we had that?? It's
been awhile for sure. Monsoonal moisture throughout the region will
keep clouds and rain chances prevalent Monday through Thursday with
Tuesday afternoon to Wednesday evening looking like the most active
period in the extended. Forecast QPF amounts generally range from
1/2 to 1 inch throughout the area through Thursday with some higher
elevations spots currently forecast to see above 1 inch. As we'd
expect with widespread clouds and rain, forecast highs run well
below normal, especially for Wednesday with 60s and 70s expected.
This pattern looks to change starting on Friday with the upper flow
becoming more southwesterly again as weak ridging again tries to
establish itself into next weekend. This should dry things out a bit
and allow temps to slowly start to warm up into the Labor Day
holiday weekend.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 428 PM MDT Sat Aug 23 2025

VFR conditions with light and variable winds this evening and winds
generally under 10 kts during the day Sunday. Mid-level and high
clouds will increase through the period as monsoon moisture begins
to filter northward. Isolated showers and thunderstorms are expected
to largely remain south and east of KBYI on Sunday, however much
variation exists amongst hi-resolution models, with several showing
activity advancing from a more westerly direction and overspreading
the region much further north. At this time, have only included VCSH
at KBYI through 00z and will continue to assess future model runs.

&&

.FIRE WEATHER...
Issued at 124 PM MDT Sat Aug 23 2025

It remains hot and dry today for most with just a few isolated
storms in parts of the South Hills and Southeastern Highlands once
again. Min RHs today are still in the 10 to 20 percent range with
wind gusts around 15 to 25 mph. Our hot and dry weather pattern
finally begins to break down on Sunday, so we will start to see some
big changes moving into Eastern Idaho as monsoon moisture begins to
arrive. Min RHs on Sunday will range from 20 to 30 percent in the
southern half of our coverage area and from 15 to 20 percent in the
northern half. At this point, thunderstorms on Sunday still appear
to be mostly isolated in nature, but we will see some make it into
the Central Mountains, too. While this will likely keep things below
Red Flag Warning criteria on Sunday, it's important to note these
storms are more likely to be a mix of wet and dry storms before the
bulk of the monsoon moisture arrives on Monday, so fire weather
conditions will be elevated on Sunday, but not quite critical.
Chances for a wetting rain will increase for Monday through
Thursday, likely peaking on Wednesday.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.

&&

SHORT TERM...AMM
LONG TERM...McKaughan
AVIATION...Cropp
FIRE WEATHER...AMM