470
FXUS65 KPIH 032101
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
301 PM MDT Mon Jun 3 2024

.SHORT TERM...Today through Tuesday Night.
Early afternoon satellite imagery shows a H5 trough over the
PacNW and NRN Rockies which will continue to drive a cold front
through SRN Idaho this afternoon and evening. This will support a
mix of scattered showers and thunderstorms through sunset tonight
ahead of drier conditions returning overnight. Rainfall has been
heaviest across the WRN-CNTRL Mountains today associated with
lingering atmospheric river moisture with the Stanley Ranger
Station seeing 0.64" of rain so far today as of 230 PM, breaking
the previous daily record of 0.40" set in 2001. Even heavier
precipitation in that 1-2" range has been seen further west with
several minor rises on rivers so far in our CWA we have been
keeping an eye on. As a result of these higher rainfall totals and
a rain on snow event, a FLOOD WATCH remains in effect for the
WRN-CNTRL Mountains through tonight with impacts expected in the
backcountry and along smaller creeks and streams.

Precipitation will decrease in areal coverage west to east this
evening as dry conditions return for Tuesday associated with the
leading edge of a H5 ridge of high pressure building into the Gem
State. As a result, highs in the 50s/60s today will increase the
60s/70s for Tuesday with overnight lows in the 40s/50s outside of
some 30s in our colder, high elevation mountain valleys.

Winds today remain elevated especially across the Snake River
Plain where wind gusts around 40-60 mph have been recorded. As a
result of these strong winds aided by 40-50 kt 700 mb winds aloft,
a WIND ADVISORY remains in effect until 9 PM across the Upper
Snake Plain. The latest forecast for Tuesday does support the
potential for a LAKE WIND ADVISORY on Tuesday for American Falls
Reservoir. This is supported by 25-40 kt 700 mb winds which will
bring gusts to around 30-45 mph across the Snake River Plain.
MacKay

.LONG TERM...Wednesday through next Monday.
The extended forecast start off with relatively quiet weather on
Wednesday. We will be under a ridge of high pressure by midweek
with our highs warming into the upper 70s and low 80s for most of
the area. Winds will still be breezy on Wednesday afternoon with
gusts of 25 to 35 mph through the eastern Magic Valley and Snake
Plain. Highs will jump up about 5 to 10 degrees for Thursday
afternoon with the NBM showing about a 40 to 60 percent chance of
highs reaching or exceeding 90 degrees F through the eastern Magic
Valley and lower Snake Plain. Even where we don`t hit 90 on
Thursday, we`ll be in the mid to upper 80s. Highs continue to
increase by a couple of degrees each afternoon through Saturday
with a 50 to 70 percent chance of reaching 90 degrees from
Pocatello to Twin Falls on Friday and Saturday afternoons. Idaho
Falls will be close to 90, with about a 40 to 60 percent chance of
reaching it Friday and Saturday. A weak shortwave arriving
onshore Thursday into Friday will work to bring some moisture up
along the ridge and re-introduce about a 15 to 30 percent chance
for showers and storms on Thursday and Friday afternoons with the
better potential in the higher elevations of the Southern Hills,
Central Mountains, and Eastern Highlands. This continued troughing
off of the West coast along with a low over Baja California will
work to bring some more rain and storm chances to the area through
the weekend, though uncertainty remains with how strong the ridge
of high pressure will be through at least Saturday. With
increased cloud cover and about a 20 to 40 percent chance of
showers and storms for both Sunday and Monday, highs will drop a
few degrees for Sunday and drop farther for Monday, into the 70s
and low 80s. AMM

&&

.AVIATION...For the 18Z TAFS through 18Z Tuesday.
The forecast through the rest of today will be wet and windy.
Where showers pass over terminals, expect conditions to drop to or
very near MVFR due to low clouds and potential impacts to VIS.
Low clouds have dropped conditions down to IFR at times already at
SUN. Any showers and storms are expected to be wrapped up by
midnight. The wind today will be strongest at IDA where gusts will
approach 40 kts this afternoon. At all other sites, gusts will be
between 25 to 30 kts. Wind gusts will back off overnight at SUN
and DIJ, but remain gust at 25 kts at BYI, PIH, and IDA. Tuesday
will be much drier, but still breezy with gusts at all sites
between 20 to 30 kts with the strongest gusts at BYI, PIH, and
IDA. AMM

&&

.FIRE WEATHER...
Radar shows precipitation moving into the central mountains.
Widespread wetting rains will overspread the region early this
morning with chances for isolated thunderstorms during the
afternoon and evening. The Weather Prediction Center has included
portions of Fire Weather Zones 475, 476, and 422 in their
Excessive Rain Outlook. The most accumulated rainfall will be over
the Sawtooths and Stanley region, where 1 inch to 3 inches of QPF
is forecast to fall through tonight. During the 24-hour or so
timeframe, 1" to 1.50" is forecast over the eastern half of the
Ross Fork burn scar, with 1.50" to 2" over the western half.
Elsewhere, generally 0.40" or less is forecast with locally higher
totals of 0.50" to 1" in the high terrain of the eastern
mountains. Min RH will continue to increase today, ranging 40 to
70 percent. Elevated winds aloft will support breezy conditions at
the surface each afternoon and evening through Tuesday or
Wednesday. The strongest SW to W winds are expected across Fire
Weather Zone 410, where SW winds will range 25 to 35 mph with
gusts 40 to 50 mph. The pattern turns dry and warmer beginning
Tuesday as a ridge of high pressure builds in from the Southwest.
Temperatures will even reach into the 90s for some portions of the
Magic Valley and Snake River Plain beginning Thursday through
late week. Minimum humidities will widely range 15 to 40 percent
during this timeframe, but winds should remain light. Cropp

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 9 PM MDT this evening for IDZ052>054.

Flood Watch until midnight MDT tonight for IDZ072-073.

&&

$$