Lewiston, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

882
FXUS66 KOTX 021144
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
444 AM PDT Wed Apr 2 2025

.SYNOPSIS...
A cool and unsettled weather pattern will persist through Thursday
with a warming and drying trend by the weekend.

&&

.DISCUSSION...
Today through Thursday: The low has moved south, but we remain on
the backside of the trough with additional weather disturbances
moving through. Showers are again redeveloping this morning and
will continue through the evening hours across northern
Washington, extreme eastern WA and the ID Panhandle. As of 2am,
there is an area of convergence between the two disturbances that
is creating some light rain or sprinkles across the Spokane/CdA
area south onto the Palouse and moving towards Shoshone
county. While most of it will be rain, temps are cold enough on
the Palouse for some light brief snow this morning. There is
enough instability for isolated afternoon thunderstorms (15-20%
chance), mainly for northern WA and the northern and central ID
Panhandle. However, cannot rule out the potential for the Spokane
area as well.

Thursday is looking fairly similar as the last push from the
north will bring a shower and isolated thunder threat, mainly to
extreme eastern WA and the ID Panhandle. With this stronger
northerly push as the trough begins to exit and the ridge nudges
closer to the coast, we will see an increase in winds down the
Okanogan Valley. There is a 60-70% chance of sustained winds of
15 mph and a 20-30% chance of sustained speeds over 20 mph. There
is a 30-40% chance of seeing gusts to 30 mph.The winds will push
down the Okanogan Valley and onto the Waterville Plateau and parts
of the northern Columbia Basin.

Temperatures will be at or a couple degrees below average for the
beginning of April. Highs will be in the upper 40s and 50s, with
lows in the upper 20s to mid 30s.

Friday through Sunday: Ensembles models are in really good
agreement that the ridge builds in for Friday through the weekend
brining warming temperatures and a very pleasant weekend. Daytime
temps will be in the 50s Friday and by Sunday widespread 60s with
around 70 for parts of the LC Valley and areas south of Moses
Lake. Dry air in place and clear to mostly clear skies will allow
overnight temps to remain chilly through the weekend. The EC
ensemble is still showing drier precipitable water values than the
GFS ensemble, which could impact low temps, as well as relative
humidity values for any prescribed burns planned.

Monday and Tuesday: The ensembles are in agreement of the ridge
being transient and moving east Monday, but they differ in how
much influence a trough trying to approach the west coast will
have. Currently about 65% of the guidance suggest precipitation
moving east of the Cascades. The NBM has increased the chance of
precipitation to 30-40%. Have daytime temps cooling a few degrees
given the increase in cloud cover and potential for light rain.
Overnight temps will be above average given the cloud cover. Snow
levels start out high at 5-6k ft, and lower by about 1k ft by
Tuesday morning.

Wednesday: Guidance shows a broad ridge developing over the
western US. About 30% of the ensembles suggest it to be a messier
ridge with continued threat of mainly mountain showers. /Nisbet

&&

.AVIATION...
12Z TAFS: Showers have blossomed overnight and have vcsh and/or
prob30 for a -shra for PUW/LWS thru 17-18Z. This afternoon showers
will become more widespread across northern WA, eastern WA and the
ID Panhandle, with a prob30 for -shra from 21Z-03Z for
GEG/SFF/COE/PUW. Things will wane through the evening, but showers
will redevelop again after 09Z and could impact PUW.


FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Low confidence on
on IFR conditions developing for GEG/SFF/COE and so have taken out
cigs below 1k ft.

-----------------------
Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        53  33  53  31  56  32 /  50  30  20   0   0   0
Coeur d`Alene  50  32  51  28  55  29 /  60  50  50   0   0   0
Pullman        49  31  48  30  54  31 /  30  20  30  10   0   0
Lewiston       55  36  56  34  59  34 /  20   0  20  10   0   0
Colville       52  30  53  27  57  30 /  60  50  10   0   0   0
Sandpoint      47  32  48  27  55  29 /  60  50  60  10   0   0
Kellogg        45  34  45  27  50  30 /  70  40  70  10   0   0
Moses Lake     59  34  59  32  62  34 /   0   0   0   0   0   0
Wenatchee      56  34  58  35  59  37 /   0   0   0   0   0   0
Omak           57  33  59  31  61  34 /  20  30   0   0   0   0

&&

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

$$