529
FXUS65 KPIH 130709
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
109 AM MDT Thu Aug 13 2026

.KEY MESSAGES...

- Isolated to scattered thunderstorms this afternoon. Gusty
  outflow winds possible near storms.

- Threat for showers and thunderstorms increases Thursday
  through Saturday.

- Locally heavy rain possible with burn scars most vulnerable.

&&

.DISCUSSION...
Issued at 108 AM MDT Thu Aug 13 2026

Forecast remains mostly consistent. We have southwest flow over
our area with a longwave trough set up over the west coast. A
strong circulation over central California will break up today.
A large chunk of that circulation will eject towards our region
today. As it moves towards our area, it will interact with the
monsoon moisture and produce widespread showers with isolated to
scattered thunderstorms. The track of the low has consistently
been through the Magic Valley. As a result, the Magic Valley may
see more showers and less thunderstorm activity. Along the
edges of that track, scattered storms look likely. Eastern
Idaho, especially the eastern highlands has been consistently
favored for heavier rainfall amounts from storms with up to 0.50
inches possible this afternoon. Convection and qpf amounts
across the central mountains is a bit of a question mark with
how much the mid and upper level clouds from the low suppress
development. A flash flood watch remains in effect for the Big
Rock Fire east of Idaho Falls where combination of steep
terrain, the effects of the recent burn, and the potential for
heavy rain exist. Most of the activity will move into Montana
this evening, but a few isolated showers may persist through the
night.

On Friday, a second impulse arrives from the southwest. This second
system isn`t nearly as strong. As a result, coverage isn`t as
widespread. Models are favoring the mountains and highlands for the
best chances for activity on Friday, especially the central
mountains which are closer to the storm track. Locally heavy
rainfall will remain a threat as the monsoonal moisture isn`t going
anywhere.

On Saturday, one final impulse works through the region. The best
chances for storms is across the central mountains as the flow
begins to flatten from southwesterly to westerly. Isolated to
scattered showers and thunderstorms will remain possible areawide
largely due to the monsoon moisture. Potentially, could see a
limited flash flood threat once again Saturday. But the convection
is beginning to shift from organized (good idea of where convection
will be) to disorganized (random).

The forecast for Sunday into early next week looks largely dry. But,
the moisture is still in place. Dew points will still be sitting in
the mid 40s to low 50s across the region, which is high for our
area. Think at least isolated heat of the day pop up storms will be
around. The cap associated with the ridge is rarely strong enough to
completely suppress convection when the moisture is as high as it is.

Daytime highs look well below normal for the remainder of the week
and will not approach normal until early to mid next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 108 AM MDT Thu Aug 13 2026

Main issues are once again thunderstorm potential. Will include
a prob30 this afternoon for gusty outflow winds. Otherwise,
expect showers around most areas this afternoon. The threat for
isolated to scattered storms will persist into the weekend.
Locally heavy rain may accompany these storms.

&&

.FIRE WEATHER...
Issued at 108 AM MDT Thu Aug 13 2026

Red flag warnings remain in place across the region for
scattered thunderstorms and gusty outflow winds today. Locally
heavy rain is possible with storms, especially across east Idaho
this afternoon.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon today to 9 PM MDT this evening for
IDZ410-411-413-422-425-427-475-476.

&&

$$

DISCUSSION...13
AVIATION...13
FIRE WEATHER...13