099
FXUS66 KOTX 230011
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
411 PM PST Sat Feb 22 2025

.SYNOPSIS...
Rain will arrive this weekend as high temperatures warm
into the 40s and low 50s. Runoff from rain and melting snow will
lead to increased flow and minor flooding across southeast
Washington and the central and southern Idaho Panhandle.
Another weather system Monday into Tuesday will bring more rain and
stronger winds.

&&

.DISCUSSION...
Two systems accompanied by a moderate to strong atmospheric river
are on track to impact the region this weekend. Models continue to
be in good agreement with the ridge over the Western US
progressively flattening as the systems ride overtop.

Tonight: The first system will arrive tonight as a warm front lifts
north across the Inland Northwest. PWATs will increase to 200 to 250
percent of normal as this front spreads north supporting widespread
rainfall. Heaviest rainfall amounts will be across the Cascades, far
eastern Washington, and the Idaho Panhandle as strong westerly flow
aloft favors orographic enhancement.

Tomorrow: A second surge of widespread precipitation will occur
tomorrow as a more compact low nears the northwest coast. The low
will direct moist air out of the southwest into the Inland Northwest
through the day tomorrow and into early Monday. The 48 hour
precipitation totals range from 0.80 to 1.40 inches for the lowlands
of far eastern Washington and 1.5 to 2.5 inches over the mountains.
Additionally, winds have increased for Sunday night into early
Monday as a cold front moves through the region with wind gusts
ranging from 30 to 45 mph.

The combination of warmer temperatures, rain, and breezy winds will
cause rapid snowmelt across the lowlands, resulting in rises on the
flashier creeks and streams across Spokane County and throughout the
Palouse. Field flooding and ponding of water in urban areas with
poor or clogged drainage will be of concern.

Monday and Tuesday: Models continue to show another deepening
surface low moving northward along the Pacific Northwest coast on
Monday, creating a strong pressure gradient across the region,
bringing more gusty winds and precipitation. Models and their
ensembles continue to show a 30 to 40 percent chance for wind gusts
over 40 mph for Spokane and the Columbia Basin and and a 70 percent
chance for wind gusts over 40 mph for Pullman. If the stronger winds
were to pan out, saturated soils may exacerbate impacts with
isolated to scattered tree damage. Snow levels look to decrease
heading into the workweek, so mountain pass snow is something to
watch with this system. Currently, there is a 60% chance for Stevens
Pass to receive 12 inches of snow.

Mid and late week:
Confidence continues to increases that upper ridging will prevail
across the region mid to late week. Near to above seasonable
normal (normal is 44 degrees for Spokane) temperatures are
expected especially across the Columbia Basin. There will be a
subtle wave moving through the upper flow Thursday and will bring
a low confidence precipitation chance of 20-30% across the mtns
and eastern WA/ID Panhandle.

&&

.AVIATION...
00Z TAFS: Another round of rain is on track to move in around 04Z
tonight and will continue through the TAF period (except for
KEAT/KMWH where probability of rain is low). There is the
potential for KGEG- KSFF- KLWS- KCOE to see wind shear values of
30 knots or more at 2000 feet this evening through tomorrow
morning.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate
confidence in timing and location of upcoming precipitation.
Ceilings expected to degrade to MVFR with lower confidence for
IFR overnight. Moderate to low confidence of wind shear values
being greater than 30 knots difference.

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

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        40  49  37  49  38  48 /  90  80  90  40  90  30
Coeur d`Alene  38  46  35  48  35  46 / 100  90 100  30  90  50
Pullman        38  46  36  47  37  45 / 100  90 100  50  90  40
Lewiston       41  52  39  52  39  53 /  90  90  90  40  90  30
Colville       37  46  31  45  35  46 / 100  70  90  30  90  40
Sandpoint      37  41  32  43  33  39 / 100  90 100  30  90  70
Kellogg        39  44  37  47  36  40 / 100 100 100  30  90  70
Moses Lake     40  54  35  50  38  54 /  80  70  50  60  60  10
Wenatchee      37  47  34  44  35  48 /  90  80  60  70  60  20
Omak           35  42  31  41  33  42 / 100  60  80  50  80  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flood Watch from 10 PM PST this evening through late Monday
     night for Central Panhandle Mountains-Coeur d`Alene Area-
     Idaho Palouse-Lewis and Southern Nez Perce Counties-
     Lewiston Area-Northern Panhandle.

WA...Flood Watch from 10 PM PST this evening through late Monday
     night for Lower Garfield and Asotin Counties-Northeast Blue
     Mountains-Northeast Mountains-Spokane Area-Washington
     Palouse.

&&

$$