476
FXUS66 KOTX 141153
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
453 AM PDT Tue May 14 2024

.SYNOPSIS...
An upper level ridge will briefly rebound Tuesday and Wednesday
with temperatures above normal and breezy winds across central
Washington. Unsettled weather returns Thursday through the
weekend as multiple systems move through the region. This will
bring breezy winds to the region Thursday and Friday along with
chances for mountain precipitation and a gradual temperature
cooldown.

&&

.DISCUSSION...
Tuesday and Wednesday: A shortwave trough that brought showers and
isolated thunderstorms across northeast Washington and north Idaho
yesterday evening is exiting to the east into Montana as an upper
level ridge behinds to rebound to our west. Areas across far
northeast Washington and north Idaho will see a small chance (10%)
for weak showers this afternoon, with dry weather expected for the
rest of the forecast area.

The influence from the ridge over the Inland Northwest will not be
as strong as it was this past weekend as systems over northern BC
inhibits it from amplifying. Under a broad northwest flow aloft,
temperatures will warm by a couple degrees for Tuesday and
Wednesday. Continued onshore low level flow will support a tight
cross-Cascade pressure gradient Tuesday and Wednesday afternoons
with breezy winds across central Washington. Models are hinting that
Wednesdays winds will be stronger across the region compared to
Tuesday, notably for central Washington, as winds begin to
increase aloft and a strong west-northwest oriented jet streak
sets up slightly north of the Canadian border. Right now, the NBM
is giving the Waterville Plateau a 40-50% chance for wind gusts
over 45 mph and a 20% chance for areas such as Wenatchee, Ephrata,
and Mansfield for wind gusts over 45 mph. /vmt

Thursday: A cold front will arrive on Thursday, but the majority
of the model guidance brings it through late enough in the day
we won`t cool much until the evening. High temperatures from the
National Blend of Models (NBM) ranges from the mid 70s in north
Idaho to the mid 80s in the Columbia Basin and the L-C Valley.
The NBM limits chances for showers to a 20 to 30 percent to the
high terrain of the north Washington Cascades, and the mountains
along the Washington/Canada border Thursday afternoon and Thursday
night. For the majority of the Inland Northwest, gusty west winds
will be the most notable weather change late in the day and
through the night. West winds of 15 to 25 mph with gusts to 35 mph
are likely in the evening through the Cascade gaps and across the
Columbia Basin into the Spokane and Pullman areas. Winds of this
magnitude will be capable of producing localized blowing dust near
fields that have been recently planted. The operational run of
the GFS is stronger than roughly 90 percent of the ensembles with
sustained winds close to 30 mph for the areas mentioned above.
While this scenario appears unlikely at this time, we will be
watching the wind forecast closely on Thursday.

Friday: Breezy west winds will continue into Friday as cooler
maritime air spills over the Cascades into eastern Washington and
north Idaho. Wind through the night will keep overnight lows
relatively mild Friday morning (mid 40s to low 50s). However,
afternoon highs will be above 10 degrees cooler Friday than
Thursday with upper 60s in north Idaho and low to mid 70s across
central and eastern Washington. Scattered showers will be
enhanced by the rising terrain of the mountains of north Idaho and
northeast Washington.

Saturday through Tuesday: The ensembles are struggling to handle
an increasingly fast west to east flow across the Pacific Friday
into early next week. Some of the ensembles deepen a chilly trough
more than the other ensembles. The NBM temperature output is a
"middle of the road" forecast over the weekend into early next
week with highs ranging from the mid 60s to the mid 70s. In
general, guidance suggests near or below average temperatures
early next week with scattered showers. However, we may see some
significant changes to the forecast depending on how the upper
trough develops this weekend. A few of the ensembles have a day or
two early next week under an upper trough with daytime
temperatures as chilly as the 50s with showers. And other
ensembles amplify a ridge along the coast with highs in the upper
70s and 80s. /GKoch

&&

.AVIATION...
12Z TAFS: VFR conditions will prevail over the next 24 hours as
high pressure builds into the region. There will be some passing
mid to high level clouds through the region today with some
cumulus clouds this afternoon. Onshore flow will continue to
support breezy winds through the Cascade gaps this afternoon and
evening.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
in VFR conditions.

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

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        75  47  77  51  79  50 /   0   0   0   0   0   0
Coeur d`Alene  72  47  74  50  76  49 /   0   0   0   0   0  10
Pullman        69  47  72  50  75  49 /   0   0   0   0   0   0
Lewiston       77  52  81  55  85  55 /   0   0   0   0   0   0
Colville       76  45  79  47  79  43 /   0   0   0   0  10  10
Sandpoint      71  46  72  49  74  48 /   0   0  10  10  10  20
Kellogg        67  50  71  52  72  51 /   0   0   0   0  10  10
Moses Lake     80  49  85  52  85  50 /   0   0   0   0   0   0
Wenatchee      78  53  81  56  81  53 /   0   0   0   0   0   0
Omak           81  50  83  51  82  48 /   0   0   0   0   0   0

&&

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

$$