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706
FXUS65 KPIH 240905
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
305 AM MDT Mon Jun 24 2024

.SHORT TERM...
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Today through Tuesday Night.
Under the continued influence of a ridge of high pressure
overhead, seasonably warm and dry conditions will continue through
Tuesday with highs in the 80s to mid 90s. Temperatures today will
be slightly cooler versus Sunday given slightly lower H5 heights
with a mix of zonal/SW flow following yesterdays passing trough in
Canada. Associated with that H5 trough passing to our north in
WRN Canada yesterday, wind gusts were observed up to 30-55 mph
with winds expected to remain elevated again for today and Tuesday
aided by 25-35 kt 700 mb winds aloft. Winds will be strongest
during the afternoon hours with gusts today around 30-50 mph,
slightly less for Tuesday around 20-40 mph. A low-end WIND
ADVISORY potential exists again for the Arco/Mud Lake Desert today
but have held off on any issuance at this time.

As prevailing SW flow returns for Tuesday, high temperatures will
warm by around 2-5 degrees as attention then turns to an
approaching H5 trough in the NE Pacific and a moist air mass
setting up over the SW CONUS. Moisture working overtop this ridge
feature (accentuated by the approaching midweek trough) will
begin moving into the region Tuesday night as conditions remain
predominantly dry outside of a 5-15% chance of showers south of
the Magic Valley to along the Utah/Nevada border. MacKay

.LONG TERM...Wednesday through next Monday.
While still under the influence of high pressure for Wednesday,
moisture working overtop this ridge feature in addition to an
approaching H5 trough, will support isolated showers and
thunderstorms back in the forecast throughout the day with an
increase in cloud cover. PWATs will also be on the rise for
Wednesday, rising up to around 0.75-1.00" which is around 150-200%
of normal for late June given our typical dry conditions around
this time of year. Given precipitation chances are only currently
sitting at 15-30%, conditions will remain mostly dry with those
areas that see more organized convection seeing the best potential
for more moderate, localized rainfall.

The moisture in place Wednesday will be forced east for Thursday
as a H5 trough in the NE Pacific moves onshore, driving a cold
front across SRN Idaho. Best chances for isolated precipitation
will shift SE of the Snake River Plain and along the Continental
Divide as strong winds usher in a drier airmass to round out the
work week. Winds on Thursday look to be the strongest of the week
with gusts up to 45-65 mph on the latest NBM 24-hour maximum wind
gust forecast. This will be supported by 30-45 kt 700 mb winds
overhead and a tighter PGF between the departing ridge and
approaching trough. As a result, the potential for wind products
will continue to need to be monitored to capture these stronger
winds.

Courtesy of cooler air moving in behind Thursday`s cold front,
highs in the 80s to low 90s on Wednesday will drop to the 70s to
mid 80s on Thursday before dropping even more for Friday down to
the 70s to low 80s. This will mark a brief return to more
seasonable conditions but will be short lived however as a H5
ridge of high pressure begins to quickly fill in behind this
exiting trough for the start of the weekend. With that trough now
east of the Rockies for Saturday, highs will climb back into the
80s to low 90s for both Saturday and Sunday. Both the GFS/GEFS and
ECMWF/EPS models show a secondary H5 trough in the NE Pacific
moving onshore for Sunday which will help to reintroduce a 10-30%
chance of afternoon showers and thunderstorms across the CNTRL
Mountains, Upper Snake Plain, and ERN Highlands as conditions
remain predominantly dry elsewhere. A cold front on Sunday will
also bring an increase in winds followed by cooler temperatures
for Monday. Those shower and thunderstorm chances will continue
into Monday as the trough passes directly over the NRN Rockies,
bringing highs back down to the 70s to low 80s as breezy winds
persist. Behind that Sunday/Monday trough, ensemble models
continue to support the return to drier, zonal/SW flow under the
increasing influence of a H5 ridge of high pressure through
Independence Day. This will bring a return to dry conditions as
temperatures seeing a warming trend through July 4th. MacKay
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&&

.AVIATION...
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For the 12Z TAFS through 12Z Tuesday.
Predominant VFR and dry conditions will continue into Tuesday
under clear skies with high pressure overhead. Elevated winds will
be the primary impact for Monday as light winds this morning
increase to 12-25 kts with gusts to 20-35 kts by this afternoon.
Following peak winds this afternoon, winds will begin to subside
this evening with lighter winds expected overnight. MacKay
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&&

.FIRE WEATHER...
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Dry and seasonably warm conditions will continue through Tuesday
under high pressure as winds remain elevated, with gusts up to
30-50 mph today and 20-40 mph on Tuesday. Afternoon minimum RHs
will also bottom out in the single digits and teens. Changes are
on the way for Wednesday as moisture begins to work overtop this
ridge feature overhead, aided by an approaching low pressure
system in the NE Pacific. This will help to introduce a 10-30%
chance of showers and thunderstorms regionwide for Wednesday, of
which will shift to being confined SE of the Snake Plain and along
the Continental Divide for Thursday as a cold front moves across
SRN Idaho. Winds will see an increase on Thursday with afternoon
gusts up to 40-65 mph, strongest across FWZ 410. While afternoon
humidities will see some minor improvement on Wednesday, drier air
associated with this cold front will drop humidities back into
the teens across portions of FWZ 410, 425, and 476.

A cooler airmass will then shift into place for Friday with highs
back to near climatological norms for late June. A ridge of high
pressure filling in behind this exiting trough will bring warmer
and dry conditions for the start of the weekend, with a secondary
trough moving in for Sunday/Monday. This will bring another round
of isolated showers and thunderstorms in addition to strong winds
on Sunday as another cold front passes through the region. MacKay
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&&

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

&&

$$