665
FXUS65 KPIH 280845
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
245 AM MDT Fri Jun 28 2024

.SHORT TERM...Today through Saturday Night.
Following Thursday`s cold front which brought wind gusts up to 74
mph to Tom Cat Summit, zonal/NW upper-level low will continue for
Friday leading to seasonably cool conditions across CNTRL and ERN
Idaho. Lows in the 30s/40s/50s will climb to the upper 60s to low
80s this afternoon with much lighter winds, generally less than
20 mph regionwide. Quiet winds and dry conditions will continue
into Saturday under the increasing influence of a H5 ridge of high
pressure shifting overhead. As this ridge axis passes over the
NRN Rockies, highs on Saturday will be around 8-16 degrees warmer
in the 80s to mid 90s courtesy of the return of predominant SW
flow aloft. Further to our west in the NE Pacific, our next H5
trough remains on track to move onshore Saturday night into Sunday
bringing changes on the way to round out the weekend into early
next week. MacKay

.LONG TERM...Sunday through next Friday.
As that aforementioned H5 trough moves onshore on Sunday, winds
will increase by the afternoon hours to around 15-30 mph with
gusts to 30-50 mph primarily across the Snake River Plain as a
cold front begins to work east across SRN Idaho. As a result,
isolated to scattered showers and thunderstorms are expected
starting Sunday afternoon of which will continue into Monday with
best chances further north and east along the Montana and Wyoming
border regions. This is where there a 30-70% chance of
precipitation and 20-40% chance of thunderstorms will exist with
the driest conditions expected further SW in and around the Magic
Valley. Given PWATs in the 0.50-0.75" range throughout this event,
we may also see a mix of wet and dry thunderstorms. Strong winds
will continue into Monday as well with the potential for LAKE WIND
ADVISORIES and or WIND ADVISORIES to capture the strongest winds
dependent on further forecasts.

With this H5 trough now east of the Continental Divide for
Tuesday, we may see some continued isolated showers and
thunderstorms around Island Park but conditions will remain dry
elsewhere as breezy afternoon winds persist. Highs on Sunday will
be in the upper 70s to low 90s before dropping back to the upper
60s to low 80s for both Monday and Tuesday associated with colder
air building in behind this cold front. Dry conditions will then
continue midweek as a broad H5 ridge of high pressure begins to
move onshore from the Pacific in what will likely a be a heat dome
later in the week across the WRN CONUS. This will lead to
gradually warming temperatures through the weekend as conditions
remain dry. Weak moisture transport over this ridge feature will
help to introduce a slight chance of showers and thunderstorms
along the Montana and Wyoming border regions each afternoon
through the work week, but any precipitation will be very
isolated in nature. When taking a look at the GEFS/EPS models,
both are in relatively solid agreement on the warmest air mass of
the year moving into our region starting late next week with highs
across our lower elevations showing the potential for mid 90s to
low 100s. Nonetheless, it will be July after all which is on
average our warmest month of the year followed right behind by
August. MacKay

&&

.AVIATION...For the 12Z TAFS through 12Z Saturday.
VFR and dry conditions will continue into Saturday with mostly
clear skies outside of passing upper-level clouds. Under the
increasing influence of high pressure overhead, winds will be much
quieter today both today and tomorrow in comparison to Thursday,
peaking around 10-15 kts with gusts to 15-25 kts. MacKay

&&

.FIRE WEATHER...
Dry and seasonably cool conditions will continue for Friday with
much lighter winds than Thursday under the increasing influence of
high pressure heading into the start of the weekend. Highs
tomorrow will be around 8-16 degrees warmer than today with
afternoon humidities bottoming out in the single digits and teens
for both today and Saturday. Our next system remains on track to
arrive Sunday into Monday with increased winds and isolated to
scattered showers and thunderstorms as a cold front passes through
our region. Best chances for thunderstorms will be further north
and east where a 20-40% chance of thunderstorms will exist, with
driest conditions expected in and around the Magic Valley.

As this system departs for Tuesday, seasonably cool conditions
early in the week will give way to a gradual warming trend through
the weekend as a broad ridge of high pressure moves onshore from
the Pacific. This will likely lead to a heat dome later in the
week across the WRN CONUS, bringing the warmest and driest air
mass into our area so far this year. As that ridge builds in
throughout next week, we may see some weak moisture transport over
the top of this ridge feature which will aid is slight chances
for isolated showers and thunderstorms along the Montana and
Wyoming border regions as conditions remain dry with breezy winds
each afternoon. MacKay

&&

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

&&

$$