903
FXUS66 KOTX 260447
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
947 PM PDT Tue Mar 25 2025

.SYNOPSIS...
Warmer temperatures will occur into Wednesday as high temperatures
for several cities reach record temperatures in the 70s. Then
another system moves in Wednesday night into Friday with rain,
chances for thunderstorms, returning mountain snow, and more
seasonal temperatures. Some thunderstorms Wednesday evening may be
severe with damaging winds and hail up to one inch in diameter
possible.

&&

.DISCUSSION...

Tuesday night through Wednesday afternoon: Moist, upper level ridge
currently in place over the Inland Northwest has brought beautiful
weather conditions this afternoon. Temperatures across the region
are in the upper 50s to low 70s, with the L-C valley being the
exception where temperatures have warmed into the mid 70s. Precipitable
water values up near 200% of normal have brought mid and high
level clouds primarily across northern Washington and North Idaho
this afternoon. The ridge will begin to amplify tonight as a large
low pressure system nears the west coast. Deep, southerly flow
and strong subsidence inversions at the low levels will warm 850mb
temperatures to 14-16C. This translates to record warm high
temperatures in the 70s across much of the region and upper 70s to
low 80s for the L-C valley.

Wednesday evening and night: The forecast gets interesting late
Wednesday afternoon into the night as the upper level low begins
to move inland and brings the potential for strong to severe
thunderstorms. After a day of record warmth, combined with
precipitable water values 150% to over 200% of normal, daytime
MUCAPE values will increase to 1000-2000 J/kg across eastern
Washington and the Idaho Panhandle and 500-1500 J/kg across
central Washington. Additionally, strong 0-6 km shear of 40 to 60
knots will be present in the evening. While this provides the
necessary ingredients for strong to severe thunderstorms, most of
the SBCAPE will be strongly capped under the low level inversion
during the day. Currently, models keep the low and embedded waves
too far west during the bulk of the daytime heating to overcome
the -50 to -150 J/kg of convective inhibition (CIN) and tap into
the strongest instability. Some high resolution models show
isolated convection before 5PM, but a majority of models delay
convection initiation until 7-8 PM after the surface instability
begins to wane. There will be a widespread thunderstorm threat
with the continued elevated instability. MUCAPE values up to 1000
J/kg after sunset for eastern Washington and north Idaho will
continue to support isolated severe thunderstorms. The primary
hazards for any strong to severe thunderstorms will be strong
winds with erratic gusts up to 60 to 70 mph for central
Washington, eastern Washington, and north Idaho, and the potential
for hail up to a inch in diameter (quarter sized) for
southeastern Washington and the central and southern Panhandle.

Recent precipitation, and the record warmth will lead to continued
snow melt and river rises. Currently near bankfull levels are
forecast for the St Joe and Coeur d`Alene Rivers, and will continue
to be closely monitored. /vmt

Thursday evening through Friday: Temperatures will range from the
mid 50s to low 60s, with lows in the mid 40s by Thursday night. A
frontal passage will bring light rain to much of the area, with snow
levels dropping to right around mountain passes. Winds will increase
in the Okanogan Valley, Waterville Plateau, and Columbia Basin,
leaving Thursday evening breezy. The threat of showers and
thunderstorms continues through Thursday night as there is still
some atmospheric CAPE. Winds will increase again on Friday morning,
with the strongest winds over the Columbia Basin and Waterville
Plateau, with gusts of 35 to 40 mph. Winds will decrease after
sunset.

Saturday through Tuesday: An unsettled pattern will continue into
early next week, with normal temperatures and showery conditions. A
break is expected on Sunday from the precipitation, but will return
Monday as weak shortwaves move over. At this time there are no
notable systems moving through. We look to remain in a similar
pattern through much of next week. /KK

&&

.AVIATION...
06Z TAFS: VFR conditions are currently in place as an upper level
ridge sits over the region. Tonight northeast boundary layer
winds and continued boundary layer moisture over NE WA/N Idaho
Panhandle will allow for areas of shallow fog and stratus to
redevelop, with KGEG/KSFF/KCOE the most likely of the TAF sites to
be impacted by MVFR to IFR visibilities. If it develops, fog and
stratus would improve to VFR by 16Z. The ridge will begin to break
down Wednesday afternoon with the potential for strong to severe
thunderstorms emerging after 00Z Thursday. This will bring the
potential for strong and erratic wind gusts and LLWS along with
isolated hail up to a quarter inch in diameter.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: There is low to
moderate confidence for a few hours of fog and stratus to
redevelop overnight for KGEG/KSFF/KCOE. There is potential (5%
chance) for strong to severe thunderstorms after 00Z Thursday at
all TAF sites, but confidence for any specific TAF site is low.

-----------------------
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        44  74  49  60  42  55 /   0   0  50  70  60  80
Coeur d`Alene  43  72  46  59  40  53 /   0   0  50  80  60  80
Pullman        47  74  47  59  42  53 /   0   0  30  70  60  80
Lewiston       50  81  52  66  47  60 /   0   0  20  60  40  60
Colville       38  68  42  57  37  53 /   0  10  80  80  60  90
Sandpoint      43  66  45  56  39  50 /   0   0  70  90  70  90
Kellogg        46  70  49  58  42  49 /   0   0  50  80  70  90
Moses Lake     47  77  48  62  44  60 /   0   0  60  50  40  20
Wenatchee      48  73  48  58  44  56 /   0   0  80  50  40  40
Omak           45  73  46  60  42  58 /   0  10  80  70  50  70

&&

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

$$