861
FXUS65 KPIH 290904
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
304 AM MDT Wed May 29 2024

.SHORT TERM...Today and Thursday
Early morning satellite imagery shows an upper level trough in
place across the Pacific NW. Clouds, showers and a few isolated
thunderstorms are moving through the region early this morning
with some of the showers producing gusty winds in the 35-45 mph
range. As we progress through the day, expecting some increased
coverage of showers and storms, mainly across the eastern half of
the forecast area with the highest PoPs focused in the eastern
highlands and up around Island Park. Precipitation will likely
taper off by late evening. Winds will be a concern today with the
tightening pressure gradient and a Wind Advisory continues across
the Snake Plain, Magic Valley and into the Arco Desert. Expecting
sustained winds in the 25- 35 mph with gusts in the 40-50 mph
range, highest likely across the Arco Desert. Temperatures today
will be noticeably cooler as colder air moves into the region this
morning. Daytime highs will be some 15-20 degrees cooler than
yesterday which equates to mid and upper 60s for highs in the
valleys with upper 50s to lower 60s in the mountains zones.
Overnight lows tonight look cold enough to support the issuance of
a Frost Advisory in the upper Snake, Arco Desert and down towards
Shoshone.

As we get into Thursday, winds will lessen (although remain a touch
breezy) but skies will clear but precip should be hard to come by.
Despite ample sunshine, temperatures will remain on the cooler side
of normal with highs again only in the 50s and 60s. Have no fear
though, a quick warmup is expected Friday and into the weekend.
McKaughan

.LONG TERM...Friday through next Wednesday.
Our northwest flow aloft on Friday begins to loosen its grip. This
will help decrease our wind gusts to around 20 mph for Friday
afternoon and increase our highs to the upper 60s and low to mid 70s
in the valley locations and low to mid 60s in the mountains. Weak
ridging pass over us on Saturday followed quickly but a weak
shortwave late Saturday into Sunday to bring back a small precip
chance for the weekend. Ensemble cluster anomalies are split nearly
50/50 on whether we are under the influence of weak troughing versus
weak ridging, so will keep with the NBM PoPs of about 20 to 30
percent in the higher elevations of the Central Mountains and
Eastern Highlands for the weekend. This won`t temper our highs at
all on Saturday as we push into the 70s for almost everyone and low
to mid 80s in the eastern Magic Valley and lower Snake Plain.
However, it will cool us back down about 5 to 10 degrees for Sunday
afternoon. Look for an increase in wind gusts with this, too, in the
25 to 35 mph range both afternoons, but especially on Sunday.

These afternoon wind gusts will continue on Monday and Tuesday, as
will the highs in the 70s both afternoons. The 50/50 ensemble
cluster split continues for Monday and Tuesday with the potential
arrival of more troughing over our area. The ECMWF is on board while
the GFS keeps the moisture in parts of the Central Mountains and
just farther north in general. After that, zonal flow solidly takes
over as the dominant weather pattern and the heat settles in over
the area.
AMM


&&

.AVIATION...
Winds will be the biggest concern today for anyone with aviation
interests. Expecting SW winds in the 20 to 30 knot range throughout
much of the day at KBYI, KPIH, and KIDA. KSUN and KDIJ will also be
breezy but not quite as high. Precipitation this morning will
continue to move east across the region and the best chances today
will be focused closer to KDIJ but still expecting enough precip
potential around KPIH, KIDA to maintain VCSH for a good portion of
the day. KSUN and KBYI will see VCSH wording removed a bit earlier
in the day. Outside of any precipitation, VFR conditions are likely
to prevail. McKaughan

&&

.FIRE WEATHER...
A cold front moving through today will bring a mix of wet and dry
thunderstorms across most of eastern Idaho. The chance for wet
thunderstorms increases the farther north you go with a 50 percent
chance of 24-hour QPF greater than 0.1 inches in Stanley, a 70
percent chance of the same near Spencer, and a general 40 to 60
percent chance of the same for areas north and east of Idaho Falls.
The wind will also be gusting near 45 mph through the eastern Magic
Valley and Snake Plain today outside of any thunderstorm outflows.
With shower and thunderstorm outflows, gusts could be closer to 50
to 55 mph. We`ve already seen gusts around 45 mph out of meager
looking showers on radar early this morning. Wind gusts won`t be as
strong on Thursday and Friday, but will still be in the 20 to 25 mph
range.

Thanks to the cold front, temperatures will be some 10 to 20 degrees
cooler today with highs in the 60s for most with highs on Thursday
being nearly a repeat of today. Min RHs will bottom out today around
the 20 percent mark and stay in the teens and 20s Thursday through
Saturday.
AMM

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 6 AM this morning to 9 PM MDT this evening
for IDZ051>055.

Frost Advisory from 3 AM to 9 AM MDT Thursday for IDZ051>053.

&&

$$