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000
FXUS66 KOTX 111818
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1118 AM PDT Thu Apr 11 2024

.SYNOPSIS...
The upcoming weather moving into the weekend will feature a few
chances of mostly mountain showers along with a warming trend.
High temperatures for much of the area will climb into the upper
60s to mid 70s over the weekend. A cold front will bring a return
of cooler and showery weather early next week. Cold front passage
on Monday will bring breezy to windy conditions regionwide.

&&

.DISCUSSION...
Today through Saturday Night: A deep low off the central BC coast
this morning will drop south to off the WA coast this afternoon.
The low will be well offshore, around 550 miles west of Forks, WA.
But a mid level frontal boundary will move over the Cascades late
in the afternoon into the evening before moving east tonight. The
front stretches and weakens as the low off the coast continues to
move south, with a chance of showers over the northern mountains
tonight. Ahead of the front, an area of elevated instability and
increased precipitable water reaching near 180% of normal tracks
from NE Oregon into SE Washington and the Central Panhandle
Mountains. Models are in good agreement that a band of elevated
convection will develop, and thus POP`s have been increased for
places like Lewiston, Pullman, and Kellogg. A small amount of
elevated CAPE (50-100 J/KG) could produce a stray lightning strike
but confidence too low to include a mention in the forecast
through Friday morning. Friday afternoon into the early evening
instability increases further over NE Oregon, the Blue Mountains,
and Camas Prairie. The ECMWF, GFS, and NAM show SB CAPE
approaching 500-1000 J/KG with increased shear as well that could
lead to a few stronger storms. SPC has a marginal risk of severe
thunderstorms over NE Oregon, clipping the Camas Prairie. Any
storms that develop will dissipate Friday evening after sunset
with the loss of daytime heating.

On Saturday the low moves into Central CA with the flow turning
more westerly over northern Washington while remaining more
south-southwest across SE Washington and the Camas Prairie. With
the low further south the models are not as excited about
convection, although CAPE values are nearly the same as Friday
over the Blues and Camas Prairie. Have a 20% chance of thunderstorms
over the Blues where some convection may develop over the higher
terrain. Decreased cloud cover on Saturday for most areas will
allow for warmer temperatures with highs in the upper 60s to mid
70s, which is 10-15 degrees above normal. JW

Sunday through Thursday: Over the course of the day on Sunday, a
trough will drop down from British Columbia, marking the beginning
of a shift from a dry zonal flow pattern to a wetter, more active
pattern. Temperatures will be warm and skies clear through the first
half of the day Sunday before cloud cover and mountain precip begin
to creep back in. High temperatures Sunday are expected to range
from the mid 60s to low 70s, which is 10 to 15 degrees above
typical highs for early April.

Monday will be a different story. The trough out of the north will
send a fairly strong cold front through the Inland Northwest, which
will drop temperatures by 10+ degrees. Accompanying the temperature
drop will be an increase in winds regionwide. Most of the regions
will see gusts into the 30s, and gusts upward of 40 mph will be
possible for some of our windier spots including the Waterville
Plateau east to Spokane Intl. and down to the Palouse. The Cascade
Crest and higher terrain of the Idaho Panhandle will take the brunt
of the precipitation with this system, but a few showers may pop up
over the eastern third of WA as well. An active weather pattern with
intermittent precip looks to persist through at least the middle of
next week. /Fewkes

&&

.AVIATION...
18Z TAFS: A slow moving cold front will push in off of the eastern
Pacific and stall out over western Washington/Oregon tonight.
Moisture will increase ahead of this frontal system across the
Inland Northwest with a 30-60% for showers across the northern
mountains in eastern Washington and along a strip of elevated
instability stretching from northeast Oregon into the southern to
central Idaho Panhandle. This will result in showers increasing
across the KPUW and KLWS terminals after 06Z this evening into
the early morning morning hours on Friday. Cloud bases will lower
with the rain, but flight conditions remaining VFR with ceilings
expected to lower between 4-7 kft agl. Expect mountain
obscurations over the Cascades by mid afternoon into tonight.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Confidence remains
high for VFR conditions across the region through Friday morning. The
one alternate scenario is if a band of precipitation across KPUW/KLWS
contains moderate rain. If this occurs, visibilities and ceilings
may lower to below VFR with the HREF model indicating up to a 30%
chance for MVFR conditions occurring. /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        61  44  63  42  70  44 /   0  10  10   0   0   0
Coeur d`Alene  60  43  64  41  68  44 /   0  10  10  10   0   0
Pullman        61  43  62  42  70  45 /   0  50  30  20   0   0
Lewiston       68  48  68  49  76  49 /   0  60  30  30   0   0
Colville       59  40  64  36  70  41 /  20  20  10   0   0   0
Sandpoint      57  42  62  40  66  40 /  10  20  20   0   0   0
Kellogg        60  45  61  44  68  45 /  10  40  30  20  10   0
Moses Lake     64  43  66  42  75  44 /   0  10   0   0   0   0
Wenatchee      61  45  64  44  73  47 /  10  10   0   0   0   0
Omak           61  43  67  40  73  41 /  10  20   0   0   0   0

&&

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

$$