Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
289
FXUS66 KOTX 102258
AFDOTX
Area Forecast Discussion
National Weather Service Spokane WA
258 PM PST Wed Dec 10 2025
.KEY MESSAGES...
- Heavy mountain rain continues to bring a risk for flooding in
the Cascades and the Idaho Panhandle. Potential for minor to
moderate flooding along the Entiat River and Wenatchee River
in the Cascades tomorrow.
- Strong winds will impact eastern Washington and portions of
north ID this evening and tonight. Winds gusting around 45 to
55 mph.
&&
.SYNOPSIS...
Heavy mountain rain, high mountain snow, and gusty winds will
continue through Wednesday evening and Wednesday night. Winds
and rain will taper through the day Thursday. Friday and
Saturday will bring a brief break. A weak system moves in Sunday
bringing light rain the mountains. Confidence is increasing for
another atmospheric river early next week but with lower snow
levels.
&&
.DISCUSSION...
...STRONG ATMOSPHERIC RIVER BRINGING FLOODING, ROCK/MUD
SLIDES, AS WELL AS STRONG WINDS THROUGH THURSDAY MORNING...
Today through Friday: Round 2 of the Pacific northwest strong
atmospheric river is well underway this afternoon.
* Rain: The Cascades have put up some impressive precipitation
totals since midnight (Viewpoint Raws: Over 3", Dry Creek
Raws: Over 2", Stehekin Raws: Over 2"). An additional 1 to 4
inches of rain is expected for locations west of
Leavenworth/Mazama to the crest of the Cascades through
tomorrow evening. In North Idaho, an additional 1-2" of rain
is forecasted through tomorrow afternoon. Luckily strong
shadowing is currently keeping locations east of Leavenworth
dry and that will continue to be the case. The flood watch in
Chelan County was upgraded to a flood warning and is in effect
through Friday morning. The flood watch for
Kootenai/Benewah/Shoshone Counties remain in effect until
Friday morning to Friday evening as well. Lighter showery
activity will continue through Thursday night to Friday night
as the 150-200% of normal PWAT plume migrates north into
Canada. This will give time for the river flows to decrease.
* Wind: Wind advisories and high wind warnings remain in effect
until 7 AM tomorrow. Forecast looks on track still for
sustained southwest winds around 25-35 mph gusting up to 45-55
mph for the Upper Columbia Basin, Palouse, and Spokane area.
There is a 10% chance for isolated pockets of gusts greater
than 60 mph from highway 395 at the Adams/Franklin County
line, to along I-90 from Ritzville to the West Plains, the
Palouse, and wind prone locations of US-95 from Worley to Cda.
Sustained southwest 35-45 mph winds gusting up to 65 mph
remains for locations between Clarkston and Dayton. With
unfrozen and wet soils, wind impacts may be higher than usual.
A 16-18 mb gradient from Portland to Cut Bank MT will stay
established through much of the night keeping wind gusts above
40 in the advisory area. The upper ridges of southwest Chelan
County will continue to gust around 60 to 100 mph through
this evening. Mission Ridge Summit NWAC sensor gusted to 107
mph at the 1PM observation. Winds will slowly decrease
overnight into Thursday as the surface low in the lee of the
MT rockies moves into eastern MT.
Saturday through Wednesday: Mild conditions with highs in the 40s
and 50s will continue through this weekend into mid next week.
Saturday look showery in the mountains as the southern periphery of
the next atmospheric river is touching the Canadian border. The cold
front with this system will bring light rain to the Cascades up to
0.5" from Saturday night to Sunday night. Ensembles are hinting at
another potent atmospheric river early to mid next week. Snow levels
look lower for this event perhaps as low as 3000 feet near the
Canadian border. It is too early to discuss expected precipitation
amounts but there is a 20-50% chance of 2+" of precipitation in the
Idaho Panhandle mountains and an 80% chance of 2+" of precipitation
at the Cascade crest from 4 AM Monday to 4 AM Thursday. /DB
&&
.AVIATION...
18Z TAFs: MVFR CIGS/VIS will linger across parts of the region
including KGEG, KSFF, and KCOE through the day as rain and low
level clouds continue to move through. For other parts of the
region that will see downsloping winds drying out the boundary
layer (including KEAT, KMWH, KPUW, and KLWS), VFR conditions
are forecast. Gusty southwest winds expected with gusts ranging
from 30-50 kts across the Basin and into the Spokane area.
.FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Confidence is
high for VFR conditions for KEAT, KMWH, KPUW, and KLWS.
For KGEG, KSFF, and KCOE, confidence in the forecast is lower. Ceilings
could hover around the MVFR/VFR line. Moderate to High
confidence for MVFR ceilings to return to the KGEG- KSFF- KCOE
overnight.
-----------------------
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
&&
.HYDROLOGY...
The ongoing atmospheric river event will continue to drive heavy
precipitation into the high terrain through Thursday. While model
guidance indicates a gradual weakening of moisture transport (IVT)
over the next 24 hours, the cumulative impacts of prolonged rainfall
remain the primary concern. Observed 72-hour precipitation totals as
of 2:30 PM range from 4 to 8 inches along the Cascades and east
slopes, with 2 to 5.5 inches recorded across the Idaho Panhandle.
Through early Friday morning, additional QPF of 1 to 3 inches is
forecast for the Cascade crest extending into central Chelan and
Okanogan counties, while the higher terrain of the Idaho Panhandle
can expect an additional 0.50 to 2 inches.
The combination of heavy rainfall, mid-elevation snowmelt, and
saturated antecedent soil conditions continue to bring heightened
concerns for rock and mudslides. Areas of steep terrain and recent
burn scars in both the Cascades and central Idaho Panhandle are
particularly susceptible to rock and mudslides. Reports of rock and
mud on roadways have already been received in these throughout
Chelan County.
River Forecasts
Central Washington: The Wenatchee and Stehekin Rivers are projected
to crest within flood stage between this evening (Wednesday) and
early Thursday morning. Beyond the mainstem river forecast points,
rapid rises are occurring on smaller rivers and creeks, specifically
Icicle Creek near Leavenworth and Peshastin Creek.
Idaho Panhandle: The Coeur dAlene River at Cataldo is forecast to
reach Minor Flood Stage by Thursday afternoon. Smaller creeks and
streams across the region will remain elevated with high flows.
For the latest hydrographs and specific river stage forecasts,
please refer to water.noaa.gov/wfo/otx.
&&
.Preliminary Point Temps/PoPs...
Spokane 48 53 41 50 40 52 / 20 20 30 20 10 10
Coeur d`Alene 48 51 41 49 41 51 / 70 60 50 40 30 10
Pullman 48 52 45 52 41 52 / 10 60 50 20 20 10
Lewiston 53 58 49 59 43 55 / 10 20 40 10 10 0
Colville 39 48 31 43 32 44 / 30 10 10 30 20 10
Sandpoint 44 49 37 44 39 47 / 90 80 40 60 50 30
Kellogg 46 49 42 49 41 52 / 90 90 70 70 40 20
Moses Lake 48 56 39 54 37 51 / 10 10 10 0 10 0
Wenatchee 46 52 42 54 40 52 / 30 10 20 10 10 0
Omak 40 48 34 44 35 44 / 10 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory until 7 AM PST Thursday for Spokane Area-Upper
Columbia Basin-Washington Palouse.
High Wind Warning until 7 AM PST Thursday for Lower Garfield
and Asotin Counties.
ID...Flood Watch through Friday afternoon for Central Panhandle
Mountains-Coeur d`Alene Area-Idaho Palouse-Northern
Panhandle.
Wind Advisory until 7 AM PST Thursday for Coeur d`Alene Area-
Idaho Palouse.
&&
$$