534
FXUS66 KOTX 130436
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
936 PM PDT Sun May 12 2024

.SYNOPSIS...
An approaching system will deliver breezy conditions into Monday,
especially closer to the Cascades and western Columbia Basin. A
chance for showers will come to the Cascade crest, northeast
Washington and the northern Idaho Monday, lingering over Idaho
Tuesday. Temperatures will cool for Monday and Tuesday, rebound
around midweek, then decrease again later in the week as the next
shower and breezy winds chances come in.

&&

.DISCUSSION...

Sunday: Today is shaping up to be a dry day in Eastern Washington
and North Idaho. Some cumulus build ups have been observed over
higher terrain. Expecting some passing mid and high level clouds
with a dry frontal passage tonight after dark. Winds will become
breezy as the pressure gradient tightens near the Cascades into
the Waterville Plateau early this evening, with speeds near 15-25
mph, with gusts near 30-40 mph. Areas just downwind of the Blue
Mountains will see some winds near 15 mph and gusts of 20-30 mph.
Speeds abate a little overnight into early Monday.

Monday: A second wave comes through tomorrow afternoon increasing
low bringing increased cloud cover tomorrow and additional breezy
winds. There is a 15% chance of showers near the Cascade crest
tomorrow through much of the day with increased moisture thanks to
onshore flow. High resolution models also indicate a 15% chance
of thunderstorms in Northeastern Washington and the northern
Panhandle with this wave passage tomorrow. Wind gusts tomorrow
will be of a similar magnitude to this evening.

Tuesday: Mostly dry with some sporadic shower activity over
northern Idaho. Tuesday morning will be a bit breezy with north
winds down the Okanogan Valley. There is a 40% chance of gusts
greater than 25 mph before the upvalley winds decrease wind speeds
in the afternoon.

Wednesday through Sunday: The weather pattern in the extended
features an upper ridge off the coast with troughs dropping down
into the region from the northwest. Roughly 70% of the 100 member
grand ensemble from the GFS, ECMWF, and Canadian models favor
this setup, with the bulk of the moisture from these troughs
passing north of the Canadian border and breezy winds being the
main impacts. The other 30% show more of a zonal flow over the
region with dry and quiet weather. Going with the majority, the
forecast favors a cooling trend from above normal temperatures in
the mid 70s to mid 80s Wednesday and Thursday, down towards normal
values in the mid 60s to mid 70s by next weekend. Typical spring
time breezes are also forecast, except Thursday where there is a
60-80% chance of gusts of reaching 30-40 MPH or higher in parts of
Central Washington include the Wenatchee area and Waterville
Plateau as a dry cold front passes through. JW

&&

.AVIATION...
06Z TAFS: A pair of cold fronts push through the region over the
next 24 hours. The first front has pushed into W WA and will swing
across the forecast area overnight. A second front arrives Monday
evening 00-03z with more of a northwest orientation. Winds will
remain breezy through the night with gusts near 30kts possible
especially in the Cascade gaps. There will be a small risk for
marginal LLWS in advance of the front. The front first front will
deliver little to no precipitation. The second front will bring a
20-40% chance for showers across far NE WA and N ID mainly north
of a line from Kellogg to Colville. North Idaho has a 15% chance
of thunder after 18z Mon. Generally VFR skies are expected
region-wide outside some mountain obscrns on the higher peaks.
The main impact for most terminals will be gusty west to southwest
winds. Wind gusts of 20-30 mph are anticipated for most terminals
between 19-03z Monday afternoon-evening. KEAT could experience a
few periods of winds closer to 40 mph which were added as a tempo
group.  /sb


FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
There is high confidence for gusty winds with a transition in air
masses occurring in the next 24 hours. Confidence is low for
rainfall in NE WA and N ID and general pilots should be aware of
virga showers producing gusty, erratic winds. Winds could decouple
sooner than expected for sites after sunset leading to lower
confidence for exact wind speeds.

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

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        51  75  47  75  48  80 /   0   0   0   0   0   0
Coeur d`Alene  50  72  47  72  47  76 /   0  10  10   0   0   0
Pullman        50  69  47  69  48  75 /   0   0   0   0   0   0
Lewiston       55  78  52  77  52  83 /   0  10   0   0   0   0
Colville       47  75  44  77  45  81 /  10  20  10   0   0   0
Sandpoint      49  70  48  69  46  75 /   0  30  30  20   0   0
Kellogg        53  68  49  67  50  73 /   0  20  10  10   0   0
Moses Lake     53  79  48  80  51  86 /   0   0   0   0   0   0
Wenatchee      56  74  50  79  54  84 /   0   0   0   0   0   0
Omak           52  78  48  80  51  85 /   0   0   0   0   0   0

&&

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

$$