208
FXUS65 KPIH 091128
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
528 AM MDT Sun Aug 9 2026

.KEY MESSAGES...

- Red Flag Warning for the Central Mountains this afternoon due
  to low relative humidity and breezy winds.

- Very small chance for an isolated (virga) shower or storm this
  afternoon, mainly in the South Hills, very similar to
  yesterday.

- Wildfire smoke will continue to impact the area on and off for
  the next few days. Expect decreased air quality at times with
  an air quality advisory remaining in effect for Custer County.

&&

.DISCUSSION...
Issued at 210 AM MDT Sun Aug 9 2026

The heat continues today, though we will be just a couple of degrees
"cooler" than yesterday. Still, expect to see highs in the mid 90s
across much of the area. A RED FLAG WARNING will be in effect for
the Central Mountains again today due to critically low relative
humidity and breezy winds. We stay just barely below Red Flag
criteria throughout the Snake River Plain this afternoon with wind
gusts around 25 mph to 30 mph. In the same vein as Saturday`s
forecast, there is a very slight chance (again, about 10 percent)
for a few virga showers in the South Hills this afternoon. You are
more likely to see gusty winds under any radar returns today than
any rainfall. The ridge of high pressure overhead gets flattened
just a bit due to troughing developing along the West Coast early in
the week ahead, and while this doesn`t change the forecast much, it
will drop our afternoon highs by just a couple of degrees each
afternoon through the week ahead. Troughing deepens in the second
half of the week as an area of low pressure moves through
southwestern Canada and that will help drop temperatures into the
low 80s by Thursday, Friday, and Saturday afternoons. An increase in
moisture looks more likely to hold off until the second half of the
week. At this point, we will look forward to any precipitation we
can wring out of the atmosphere, but will have to see how models
changes over the next several days.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 528 AM MDT Sun Aug 9 2026

Some upper level clouds remain visitble on satellite early this
morning. These FEW to SCT mid and upper level clouds will continue
today, but are not expected to impacts conditions. Light wildfire
smoke continues with 6SM FU remaining in the TAFs for BYI, PIH, and
IDA this morning before working into SUN this afternoon. Winds are
light and variable to start the day, but get a bit breezy at times
in the afternoon with gusts 15 to 20 kts.

&&

.FIRE WEATHER...
Issued at 210 AM MDT Sun Aug 9 2026

A RED FLAG WARNING will be in effect again this afternoon for Fire
Weather Zones 475 and 476 in the Central Mountains due to low
relative humidity and breezy winds. Considered adding Zone 410 to
the Red Flag Warning for today as it looks likely that at least
portions of the western half of the zone will meet criteria, but
decided to hold off. Either way, expect elevated, near-critical fire
weather conditions across much Eastern Idaho once again this
afternoon due to very low RHs and breezy winds. It appears wind
gusts will increase a bit more on Monday, so there will likely be
some coordination with partners today about issuing a Red Flag
Warning for Monday. While there will likely be some returns visible
on radar again this afternoon, expect no precipitation to actually
fall as it all remains virga. Some gusty winds around 40 to 50
mph would be more likely around those returns.

A deepening trough along the Pacific coast will continue to
gradually flatten the ridge of high pressure over Idaho, resulting
in a gradual cool-down through late this upcoming week. Daytime
highs will return to around normal by mid-week, turning cooler than
normal late week. Dry conditions will linger through the first half
of the week ahead, with models indicating the return of monsoon
moisture by the latter half of the week.

&&

.AIR QUALITY...
Issued at 209 AM MDT Sat Aug 8 2026

An Air Quality Advisory remains in effect for Custer County through
Monday afternoon due to air quality expected to remain in the
"moderate" to "unhealthy for sensitive groups" categories.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Air Quality Alert until 3 PM MDT Monday for IDZ068>074.
Red Flag Warning from noon today to 9 PM MDT this evening for
IDZ475-476.

&&

$$

DISCUSSION...AMM
AVIATION...Messick/AMM
FIRE WEATHER...Cropp/AMM
AIR QUALITY...AMM