717
FXUS66 KOTX 151756
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1056 AM PDT Wed May 15 2024

.SYNOPSIS...
An upper level ridge will rebound through Wednesday with
temperatures above normal and breezy winds across central
Washington. A cold front will move through the region on Thursday,
bringing widespread breezy to gusty winds Thursday afternoon
through Friday, mountain precipitation, and cooler temperatures.
Unsettled weather looks to continue into the weekend


&&

.DISCUSSION...
Wednesday: An upper level ridge remains over the region today but
will begin to flatten this evening as an upper level low moves
southeastward across British Columbia. High clouds associated with
this system are streaming across the Inland Northwest under a
strong northwest flow aloft and will filter the sunshine through
the day. A strong west- northwest oriented upper level jet on the
south side of this low will be directed across southern British
Columbia Wednesday afternoon through the evening. These strong
upper level winds combined with continued onshore low level flow
tightening the cross-Cascade pressure gradient will promote
another afternoon of gusty winds through the Cascade gaps and
central Washington. Sustained winds of 20 to 30 mph and wind gusts
of 30 to 45 mph will be capable of blowing around any unsecured
lightweight objects.

...Widespread breezy to gusty winds Thursday and Friday...

Thursday: A cold front will push through the region Thursday
evening. This will be late enough in the day where temperatures
will be able to warm into the upper 70s and low 80s for one more
day. Winds will begin to pick up ahead of the front Thursday
afternoon and peak with the cold front passage as strong winds
aloft mix down to the surface. The strongest winds will be felt
across the lee of the Cascades in the late afternoon into evening
hours with sustained winds near 30 mph and gusts of 45 to 50 mph
for the Wenatchee Area, Waterville Plateau, and Moses Lake Area.
Areas across the Waterville Plateau and the northern Columbia
Basin have a 50-60% chance for wind gusts over 50 mph on Thursday.
These strong winds will increase the potential for strong cross
winds on north-south facing highways and reduced visibility due to
blowing dust near recently worked fields. Further east into the
Spokane area sustained west winds of 20 to 30 mph with gusts up to
45 mph are expected. This front will be mostly dry as limited
moisture and the strong zonal flow aloft keep the best chances for
light precipitation across Cascade crest and the higher
elevations of northeast Washington and north Idaho. Snow levels
will drop to 4000-4500 feet with very light snow for the high
mountains. /vmt

Friday: Post frontal winds will continue through Friday afternoon
as low pressure deepens over the Dakotas and the prairies of south
central Canada. While Thursday`s winds look stronger during the
frontal passage, Friday will continue to be quite windy. Sustained
west winds of 20 to 25 mph are common within the ECMWF ensemble
membership. Gusts of 30 to 40 mph are likely from late morning
into the late afternoon from the East Slopes of the Cascades
across the Columbia Basin onto the West Plains and Palouse.
Friday`s high temperatures are trending cooler as the ensemble
variability has decreased over the last 24 hours. Afternoon highs
will be 10 to 15 degrees cooler than Thursday with readings mainly
in the 60s. Rain shower chances have trended up too with a 50 to
60 percent chance of measurable precipitation for Kellogg,
Sandpoint, Bonners Ferry and Metaline Falls. Vigorous west winds
do not favor measurable rain in central Washington where there is
a 10 percent or less chance for Wenatchee, Moses Lake, Ritzville,
and Omak.

Saturday and Sunday: The Polar Jet will continue to deliver active
weather through the weekend. Temperatures will be seasonably cool
with highs mainly in the 60s. West winds will continue to be
breezy, but without big temperature swings our temperature and
pressure gradients won`t be as strong as Thu/Fri. Sustained 10 to
15 mph winds with gust of 25 mph will be common with wind prone
spots like the Cascade gaps and the Waterville Plateau reaching 30
mph or more. A broad trough and cool air aloft will generate
afternoon and evening showers enhanced by the rising terrain of
north Idaho and northeast Washington. The National Blend of Models
(NBM) generates 20 to 40 percent chances of showers across the
mountainous terrain around Sandpoint, Metaline, and Colville
Saturday. Shower chances increase Sunday afternoon to 30 to 50
percent for north Idaho as well as the mountainous terrain of
northeast and north central Washington. A few of the strongest
cells will be capable of lightning and pea hail.

Monday through Wednesday: Ensembles have trended cooler early next
week. Compared to 24 hours ago, more of the ensembles are
forecasting highs in the 60s early next week with fewer members in
the 70s. Tuesday and Wednesday will be days to watch for the
potential for widespread precipitation. The operational runs of
the GFS, ECMWF, and Canadian models dig a low into Washington and
north Idaho Tuesday or Wednesday. There are timing differences
between the operational runs as well as their respective ensemble
suites. While it is too early to count our chickens before they
hatch, this trend is encouraging. Our region could use more spring
rain. /GKoch

&&

.AVIATION...
18Z TAFS: VFR conditions will continue through the upcoming
period with bands mid to high level clouds streaming in from the
northwest. Winds will pick up through the Cascade gaps into the
western Columbia Basin again Wednesday afternoon and evening with
wind gusts up to 30 knots in the early evening. Winds will be
breezy from the southwest in the afternoon for KGEG, KSFF, and
KCOE as well with gusts up to 20 knots then subsiding after
03-04Z. Winds will generally be calm overnight before an incoming
front on Thursday. Winds will increase toward the end of the TAF
period.

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        77  52  77  45  64  41 /   0   0  10  10  20   0
Coeur d`Alene  76  50  75  44  60  40 /   0   0  10  10  40  10
Pullman        73  50  73  45  59  40 /   0   0   0  10  20   0
Lewiston       82  56  83  52  68  45 /   0   0   0  10  10   0
Colville       79  48  76  39  64  36 /  10  10  20  10  40  10
Sandpoint      74  50  72  43  58  39 /  10  10  30  30  60  20
Kellogg        71  53  70  45  55  42 /  10   0  10  30  50  10
Moses Lake     84  51  80  45  69  42 /   0   0   0   0   0   0
Wenatchee      81  55  75  47  65  45 /   0   0   0  10   0   0
Omak           84  53  78  43  69  42 /   0   0   0  10  10   0

&&

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

$$