540
FXUS66 KOTX 142138
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
238 PM PDT Tue May 14 2024

.SYNOPSIS...
An upper level ridge will rebound through 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 to windy conditions across the region Thursday and Friday
along with chances for mountain precipitation and a gradual
temperature cooldown.

&&

.DISCUSSION...

Tonight through Thursday night: The Inland Northwest will be under
northwest flow with a fairly robust Polar Jet overtop. The axis of
the jet stream will generally be directed into southern BC through
Wednesday night before a shortwave trough of lower pressure buckles
the jet over the region for Thursday into Thursday night. Stiff
upper level winds with a tightening cross-Cascade pressure gradient
each afternoon/evening will promote a period of gusty westerly winds
through the gaps. Winds of 15 to 25 mph with gusts of 30 to 40 mph
in the lee of the Cascades. Peak of the wind gusts is expected to be
in the evening hours until inversions strengthen overnight and the
boundary decouples. The set up for breaking mountain waves isn`t as
favorable over the next couple of nights, so I don`t expect a repeat
of stronger gusts of 45+ mph mixing down into populated areas of
Chelan, Wenatchee, Beverly, or the Waterville Plateau over this
period. With that said, winds do figure to increase and become
breezy and may be enough to blow around any unsecured light weight
objects.

A cold front will push through Thursday night and this will act to
tighten the pressure gradient across the region. Thursday will be a
breezy to windy day across much of the region. Strongest winds will
again be in the lee of the Cascades in the late afternoon into
evening hours with sustained winds near 30 mph and gust of 45 to 50
mph possible for the Wenatchee Area, Waterville Plateau and Moses
Lake Area. It`s also going to be windy across the Columbia Basin
into the Spokane West Plains with the potential for gusts up to 45
mph there as well. Winds may be enough to produce patchy blowing
dust across the Waterville Plateau, in the Moses Lake Area and
portions of the Upper Columbia Basin. Anyone planning on driving
across the basin should plan on the potential for strong cross winds
and reduced visibility due to blowing dust near recently worked
fields. Winds will continue to be breezy to windy through Thursday
night, especially in the lee of the Cascades.

Temperatures will continue to run above normal for mid May with
highs 70s to mid 80s. The warm temperatures will result in melting
snow with mainstem rivers seeing rises. Water temperatures also
remain very cold at this point in the spring season. Recreationalist
should be weary of the dangers of swift water currents in rivers and
wear those life jackets if planning to be out on the water. /SVH

Friday through Tuesday: At this point in time an upper level trof is
positioned overhead. Initially it brings about a progressive zonal
flow with a slight northwest to southeast orientation with a weak
precipitable water moisture feed into a disturbance exiting Friday
morning allows for windy /gusty conditions along with the expected
downsloping processes keeping a rain shadow of sorts of a good
portion of the lowland and basin areas with remaining locations
holding onto showers. On saturday and on through the remainder of
the weekend it appears the trof gets reloaded with disturbances
dropping down from the northwest and shows a tendency to dig further
south (although there remains some spread in the clusters) so some
mention of gusty winds and similar orientation of pops for showers,
and possibly some short lived weak pulse thunderstorms for the
afternoon and early evenings , remains in place over the remainder
of the weekend. This trend of general trof overhead with
disturbances dropping down from the northwest that reload it
continues on into the early part of the workweek thus the forecast
reads similar with cool temps with no trend other than NBM showing
more spread (uncertainty) in the temps via the larger box and
whisker plots of the max and min temps out through day 7. The
windiest day looks to be Friday however synoptic winds will continue
to mask the diurnal winds and result in some gusty conditions,
mainly in the afternoon and evening hours. /Pelatti

&&

.AVIATION...
18Z TAFS: High pressure will promote VFR conditions over the
Inland Northwest. There will be passing high level cirrus clouds
with fair weather cumulus clouds over the mountains this
afternoon. Onshore flow will continue to support breezy winds
through the Cascade gaps this afternoon and evening. Expect wind
gusts to between 20-25 kts at KEAT this evening after 00Z.

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

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

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        50  77  51  78  46  64 /   0   0   0   0  10  20
Coeur d`Alene  48  74  50  74  46  60 /   0   0   0  10  10  30
Pullman        47  72  50  74  46  61 /   0   0   0   0  10  10
Lewiston       54  81  55  84  54  69 /   0   0   0   0  10  10
Colville       47  78  47  77  41  65 /   0  10   0  20  10  30
Sandpoint      47  73  49  72  46  59 /   0  10  10  20  20  50
Kellogg        49  71  52  71  48  58 /   0  10   0  10  20  40
Moses Lake     51  84  52  83  46  70 /   0   0   0   0   0   0
Wenatchee      54  81  56  78  48  64 /   0   0   0   0   0   0
Omak           52  82  51  79  44  68 /   0   0   0   0  10  10

&&

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

$$