Damaging Wind in Idaho, August 9, 2024

Area Forecast Discussion
National Weather Service Pocatello ID
843 AM MDT Fri Aug 9 2024

.UPDATE...
Thunderstorms have developed in southern hills and updated
forecast to include in southern zones.
GK

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.PREV DISCUSSION... /issued 152 AM MDT Fri Aug 9 2024/

SHORT TERM...Today and Saturday. We haven't seen much in the way
of precipitation in the past 24 hours with what monsoon moisture
that has been in place. Deeper moisture is still expected later
today and Saturday. The best chance today will be across the
central mountains, the far north end of the Snake Plain and along
the Montana border. That area is also favored for higher rainfall
amounts and gusty winds. There is a 50-70% bullseye of gusts over
35 mph (and likely over 45 mph) in that area. There is a 50%
bullseye across the mountains along the Utah border, but we
suspect any area where storms can form will see stronger outflow
winds. Overnight and tomorrow morning, we should see a few
showers still around. Showers and storms redevelop later in the
morning and continue through the rest of the day. We are looking
at an even higher chance of rain over higher elevations and
potentially higher coverage of storms. There is a 70% bullseye for
winds over 35 mph (potentially 45 mph) up north and 50-90% across
the southeast highlands and Snake Plain along the I-15 corridor
from Pocatello to Idaho Falls. Keyes

LONG TERM...Sunday through Friday
The second half of the weekend looks quite a bit drier than the
first half as an upper level trough moves east of the area and weak
high pressure builds back in. Skies will be mostly clear although
but a very isolated shower chance can't be ruled out along the
Divide or into the eastern highlands. The upper flow becomes
southwesterly throughout much of next week and a series of weak
shortwaves moving through the PacNW will keep things unsettled
across the higher terrain of the eastern highlands each day. This is
the area that will be most favored for isolated to low end scattered
PoPs each day although a few showers/storm could sneak into the
Snake Plain. Temperatures will be around their seasonal norms
throughout the period with only a few degrees of variance from day
to day. McKaughan

AVIATION...VFR conditions expected to prevail through most of the period but
smoke could be a wildcard once again. For now, will maintain just 6
miles as models don't look too aggressive with smoke impacts but
we'll see how things progress. There will be some potential for
showers and storms later this afternoon, mainly at KSUN and KDIJ,
but have added VCTS at KIDA as hi-res models show some potential for
storms getting close there. Winds won't be much of an issue today,
light generally 10 kts or less, outside of any potential
thunderstorm outflows. McKaughan

FIRE WEATHER...Deeper monsoon moisture will be in place today and
Saturday. So far, we haven't seen much in the way of gusty winds
or even light rain/sprinkles. That should change as we get in the
afternoon and evening hours. Right now, coverage looks mostly
isolated. The is a small window for scattered coverage across the
southeast corner of Lemhi County (476), across the far upper end
of the Snake Plain (410), and along the Montana border (411). At
the moment, the window appears too small and too confined in space
to issue a RED FLAG WARNING this morning. That could change later
today if trends work back the other direction. In that same area,
there is a 25-45% chance of wetting rains and a 50-70% bullseye
for wind over 35 mph(likely 45 mph or higher). There is also an
area for similar winds along the Utah border in Zones 427 and 413.
For tonight and early Saturday morning, lingering showers are
expected. At the moment, there doesn't seem to be any potential
for isolated storms overnight. We will see things quickly ramping
up later in the morning with showers and thunderstorms on the
increase. Lightning/thunderstorm coverage should be much higher
tomorrow across the central mountains (475/476), the upper end of
the Snake Plain (410), Zone 411, and along the Wyoming border
south around Bear Lake (413). Chance of wetting rains increase to
60-70% up north and 30-50% across Zone 413. We will need
coordinate to see if RED FLAG WARNINGS are needed especially with
the increasing chance of appreciable rainfall in some areas. There
is a 70% bullseye up north for winds over 35 mph (likely over 45
mph) and 50-90% bullseye along and east of I-15 in Zone 413.
Slightly drier air arrives Sunday. This will limit any risk of dry
thunderstorms to isolated along the Montana border and perhaps the
southeast corner. It looks like another big surge of monsoon
moisture should impact central and eastern Idaho early next week.
Keyes

AIR QUALITY...Air Quality Advisories are in effect for Blaine, Bannock, Bear Lake,
Bingham, Caribou, Franklin, Oneida, and Power counties due to air
quality currently in the "Unhealthy for Sensitive Groups" category
and forecast to be "Moderate" the following two days. Smoke models
indicate some reprieve across the Snake River Plain early tomorrow
as drainage winds help to disperse smoke but then show smoke
filtering back in as the day progresses. Cropp

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