169
FXUS65 KPIH 080311
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
911 PM MDT Thu May 7 2026

.KEY MESSAGES...

- High pressure over the western states will keep showers out of
  the region except in the upper Snake River highlands today and
  Friday.

- Mild temperatures continue through Saturday, then very warm
  temperatures reaching the lower to middle 80s by Mothers` Day.

- Windy conditions will keep Lake Wind Advisories in effect on
  Friday and Monday afternoons and evenings.

&&

.DISCUSSION...
Issued at 1243 PM MDT Thu May 7 2026

Tonight through Sun afternoon. Northwesterly upper level flow
due to a ridge to the west will keep the storm track just close
enough over the next two nights where a small threat of
precipitation exists over the extreme northeast end of the
forecast area in the upper Snake River highlands. There is also
some cumulus development that may lead to some light shower
activity, but the air is stable enough where thunderstorms will
not be an issue. By Saturday, the upper level ridge is closer,
nearly over the forecast area. This will end the upper level
support for gusty wind at the surface, and after Fri evening,
Lake Wind Advisories will not be needed. The current Lake Wind
Advisory has been verifying since this morning with sustained
wind of 24 mph with higher gusts.

A trough moving through the upper level ridge on Sat will level
off temperatures, but the lack of such a trough on Sun will
spike temperatures some 5 to 10 degrees with widespread
afternoon highs on Mothers` Day in the lower to middle 80s in
the Snake River plain and other low elevations. Even Stanley
will be reaching the middle 70s. This will still be about 4 to 5
deg F off the record temperatures that are mainly in the upper
80s.

As the ridge axis moves closer, the upper level wind weakens and
so afternoon mixing will not be as effective in increasing the
surface wind. Still, another Lake Wind Advisory will be
necessary for the 1400 MDT to sunset period on Fri on the
American Falls Reservoir. This time period is shorter than what
happened today with wind already exceeding thresholds by 1000 at
least. Even lighter wind expected on Sat and Sun.

Sun night through Thu...The strong upper level ridge gets
stronger with 5800+ meter heights overhead. This keeps the
warming going, with middle to upper 80s for afternoon highs
developing in the low elevations, and 81 at Stanley. There is a
possibility of this ridge breaking down on Wed, so temperatures
start to cool in the forecast, but this may not occur until Thu.
This is the next time slight chance of precipitation is seen
again in eastern Idaho.

Besides the breezy to windy conditions on Mon, the breakdown of
this ridge will likely see breezy to windy conditions again on
Wed/Thu, especially in the afternoon with peak vertical mixing.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 911 PM MDT Thu May 7 2026

Gusts are done for the night at most sites with winds expected
to turn light overnight. Winds expected to become gusty once
again Friday afternoon with considerable mid to high level
clouds arriving mid to late afternoon.

&&

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

&&

$$

DISCUSSION...Messick
AVIATION...13