179
FXUS66 KOTX 082152
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
252 PM PDT Sat Jun 8 2024

.SYNOPSIS...
A weak weather system will pass through on Sunday with a chance
of showers and thunderstorms. Above normal temperatures will
continue though much of the week, with cooler temperatures by late
next week.

&&

.DISCUSSION...
Tonight through Monday: Mid and high clouds will continue to move
in tonight ahead of a short wave trough. The trough will push
east across the region on Sunday, drawing up increased moisture
from the southwest. Initially, a lack of large scale forcing and
mostly cloudy skies will limit instability through early to mid
afternoon with most areas only receiving light showers or
sprinkles. This could change in the late afternoon and evening on
the back side of this system as sun breaks help destabilize the
atmosphere. Most unstable CAPE values increase to 300-800 J/KG,
with the NBM painting the area with the best chances for
thunderstorms (30%) over the North Cascades, Methow Valley, and
Okanogan Highlands. This is where there will be a combination of
afternoon sun breaks, and cooling aloft with the passing mid level
trough. Elsewhere there will be a 10-20% chance of thunderstorms
as the atmosphere briefly destabilizes. Drying aloft combined with
a short wave ridge will bring quieter weather on Monday, except
for a 20% chance of showers or a stray thunderstorm over the north
Idaho Panhandle mountains in the afternoon. JW

Monday night to Saturday: The Inland NW will find itself in a
somewhat progressive flow, with periodic breezy conditions and
limited shower chances. A shortwave ridge tracks from the Cascades
to the Continental Divide Monday evening into Tuesday morning,
while a shortwave trough moves in from the west Tuesday. That
shortwave trough will bring some clouds and it will bring shower
chances to the Cascade crest, expanding to the northeast WA and
north ID mountain zones in the afternoon. Some showers may slip
by the Spokane/CdA area then too, but these would be isolated in
nature. The system also comes with breezy/gusty winds as a 110kt+
jet streams pushes over the top of the region. The winds increase
for the afternoon and evening hours, with speeds of 10-20 mph and
gusts of 20-40 mph. The higher range of those will be around the
lee of the Cascades to central WA. While RH values will not be
critical values, they will still be dry and the whole area is
starting to dry out so this may be of concern to the fire weather
community. Winds decline through the late evening and especially
the overnight.

Wednesday and Thursday the area see the precipitation chances wane
with a shortwave ridge moving back into the region, though look
for breezy conditions again Wednesday with gusts near 15-25 mph.
Friday and next Saturday another trough moves into the region,
though models disagree over the precise timing and track. It will
bring some precipitation chances again. However at this time 60-70%
of the ensembles keep the system more focused near the Cascades
and northern mountains, while 30-40% bring it more directly across
the CWA with broader precipitation chances and t-storm chances. I
trended PoPs a bit higher on next Saturday to account for that
uncertainty but keep the higher PoPs over the Cascades and closer
to the Canadian border. This system will also come with another
increase in the breezy conditions, especially Friday with gusts
near 20-30 mph.

Temperatures fluctuate through this period, holding above normal
Tuesday, dropping closer to normal Wednesday, rebounding toward
the mid to upper 70s to mid-80s Thursday and Friday, before
cooling closer to normal again next Saturday. /Solveig

&&

.AVIATION...
18Z TAFS: VFR conditions will prevail. An incoming weather system
will spread increasing mid and high clouds into the region through
tonight. The moisture deepens a bit more 12-18z Sunday for a
10-20% chance of rain showers. Sunday afternoon and evening
(beyond the current TAF period) as the instability increases, the
chance for rain showers increases to 20-40%, along with a 10-20%
chance of thunderstorms.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
Confidence remains high for VFR conditions through Sunday morning.

-----------------------

Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance

For additional probabilistic information for NWS Spokane airports,
please refer to the Aviation Dashboard on our webpage:
https:/www.weather.gov/otx/avndashboard

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  78  54  80  54  82 /   0  10  20   0   0  10
Coeur d`Alene  53  77  53  76  52  77 /   0  10  20  10   0  20
Pullman        53  73  53  74  51  78 /   0  10  10   0   0  10
Lewiston       61  84  59  86  58  88 /   0  20  10   0   0   0
Colville       49  78  48  78  49  81 /   0  20  30  10   0  30
Sandpoint      50  77  52  77  51  74 /   0  10  40  20   0  20
Kellogg        54  76  56  73  55  75 /   0  20  30  10   0  10
Moses Lake     58  84  55  86  54  86 /   0  20  20   0   0   0
Wenatchee      63  84  58  87  59  80 /  10  20  10   0   0   0
Omak           59  81  53  84  54  86 /   0  30  20   0   0  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$