736
FXUS66 KOTX 032217
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
317 PM PDT Thu Apr 3 2025

.SYNOPSIS...
The showers risk this evening decreases, leading into with a
warming and drying trend Friday into the weekend. Early next week
looks wet and cool again.

&&

.DISCUSSION...
This afternoon into tonight: Scattered showers will continue over
the Idaho Panhandle and eastern third of Washington through the
next few hours, decreasing in coverage and intensity heading past
sunset. The axis of an upper trough will continue to shift
southeast, with the northerly jet nosing across the region. This
is interacting with the daytime heating and convective
instability and lingering moisture to bring the aforementioned
showers. These will be most numerous over the central and southern
ID Panhandle and southeast WA along that axis. These will be in
the for of rain or rain/snow mix, with the potential for some
embedded graupel showers. T-storms may also be embedded with
these showers, but they would be isolated and weak. The winds will
be breezy from the north through early evening too, especially
around the Okanogan Valley down into the western basin and near
the Blues/Southeast WA/lower ID. Gusts of 15-30 mph will be
possible. Heading into later this evening into the overnight,
high pressure starts to build in with strong subsidence. This will
lead to clearer skies and decreasing winds. There is some risk
for patchy fog in the sheltered Idaho Panhandle valleys, but
coverage looks low. The central and southern ID Panhandle through
SE WA will need to be monitored most, as the precipitation moving
through may be enough to moisten the BL to bring a bit more fog
currently in the forecast. Low will be in the 20s to mid-30s.

Friday to Sunday. Drier and warmer weather is forecast for much of
the weekend. A high amplitude ridge of high pressure builds over
the region into early Sunday. There is the off chance of a stray
shower near the north ID mountains, near the Canadian border,
Friday PM. Otherwise look for mostly clear to partly cloudy skies
and light winds. Heading into Saturday and especially Sunday,
clouds increase some ahead of an offshore low and with an incoming
warm front. The PoPs remain low, until Sunday afternoon when the
approach of that low will bring about 20-40% chance of showers
near the Cascade crest. Temperatures will be near to slightly
above normal Friday, then a more notable warm-up comes for
Saturday and Sunday when highs will be about 10 degrees above
normal. Look for upper 50s and 60s Saturday and more 60s and low
70s Sunday, with the exception of upper 50s and lower 60s near the
Cascades. Low will remain in the 30s Saturday morning, with a few
upper 20s in the sheltered mountain valleys, then the 30s to low
40s are expected Sunday morning.

Sunday night to Thursday: The weather pattern turns a bit more
active and cooler. Between Sunday night and Monday the next
organized system moves inland, with an cold front/upper trough
couplet. PWATS rise to around 180-210% of normal or 0.50-0.80
inches. Precipitation chances expands from west to east Sunday
nigh into Monday morning, with the highest risk Monday before the
potential start to wane from the west and the higher risk starts
to retreat to the mountain zones Monday night. Some t-storms are
possible Monday afternoon, with the best chances over NE WA and
the ID Panhandle. They may be accompanied by brief heavy rains,
small hail and gusty winds. Additional shortwaves move in heading
into Tuesday to revitalize the precipitation potential. Winds in
general will become gusty through Monday with the passing front
and again Tuesday afternoon with the next disturbance. Afternoon
gusts of 10-20 mph are forecast, locally up to 30 near the Blue
Mountains and Okanogan Valley/Waterville Plateau.

As for precipitation amounts, areas away from the lee of the
Cascades and deeper Columbia Basin will see the most. The 24-hour
probability of wetting rains (>=0.1") through Monday evening is
around 70-100%, per the LREF ensemble forecast. It is only around
40-50% in the deeper basin. Then through Tuesday evening with the
next wave that probability is around 30-50% in the lowlands,
except near 10%-20% in the lee of the Cascades and deeper basin.
In the mountains the potential is around 70-90%, highest near the
Cascades. For most this will be in the form of rain. Between
Sunday night and Tuesday night around 0.20 to 0.5" of
precipitation is possible, with higher amounts in the mountains
(potentially over an inch near the Cascade crest.) The NWRFC river
forecasts do show some rises but nothing that goes high enough to
cause an impacts.

It won`t all be rain. Snow levels do drop to around 4-5.5kft
Monday evening and to between 3.5-5.0kft for Tuesday, lowest near
the Cascades. This means some snow potential around the passes.
With that said, most areas are forecast to see less than a half
inch except the Cascades which could see 1-3 inches. The best
potential there will be Monday overnight and Tuesday morning,
while the daylight hours accumulations should be less.

For Wednesday and Thursday the area remains in a southwesterly
flow, with a trough offshore and the ridge axis just to the east.
Occasional impulses ride in and this will keep some shower
chances alive around the mountains and also near the eastern third
of WA/lower ID. Overall, however, precipitation amounts if any
look lighter. It will remain a bit breezy, especially Wednesday,
with gusts forecast to be around 10-20 mph.

High temperatures will largely be in the 50s, with some 60s in
the deeper basin and L-C Valley. Lows will be in the upper 30s and
40s Sunday night/Monday morning, then largely 30s and low 40s
thereafter. /Solveig


&&

.AVIATION...
00Z TAFS: An upper trough shifting east over the area will
continue to mean some isolated -shrasn/-shra, a chance for
isolated afternoon -tsra, and local MVFR conditions in heavier
showers before 02Z. Wind will also be slightly gusty, near 20 kts
or so in the afternoon. High pressure builds in from the west
leading to drier weather and subsidence, leading to mainly VFR
conditions.


FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate to high
confidence in VFR condtions. Moderate confidence in MVFR
conditions with heavier showers. Some risk for localized fog
overnight/early Friday AM. Confidence is low. The main TAF sites
that indicates some potential is near COE, PUW, LWS, but
confidence is low with ensembles showing only a 5-10% chance at
these location.

-----------------------
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        31  56  32  62  36  67 /  20   0   0   0   0   0
Coeur d`Alene  28  55  30  60  34  66 /  20   0   0   0   0   0
Pullman        29  54  31  59  37  66 /  20   0   0   0   0   0
Lewiston       34  59  35  65  40  71 /  20   0   0   0   0   0
Colville       27  57  30  61  34  65 /   0   0   0   0   0   0
Sandpoint      29  53  30  59  34  62 /  10   0   0   0   0   0
Kellogg        27  51  31  57  36  63 /  30   0   0   0   0   0
Moses Lake     31  62  34  65  39  69 /   0   0   0   0   0   0
Wenatchee      36  60  38  63  43  65 /   0   0   0   0   0  10
Omak           31  61  34  64  38  67 /   0   0   0   0   0   0

&&

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

$$