Western Washington

637 
FXUS66 KSEW 010334
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
834 PM PDT Sat Oct 31 2026

.SYNOPSIS...Drier conditions will settle into the region into 
Monday as an upper low moves south and a ridge builds into the 
region. The first half of next week will remain mostly dry, with
chances of precipitation increasing mid to late week as a 
series of systems approaches the Pacific Northwest.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...An upper level low
will continue to weaken as it moves onshore to the south, with 
split flow briefly developing aloft over western Washington. 
Cool overnight lows in the 30s will bring areas of additional 
frost development to the area on Sunday morning while moisture 
in the low levels promotes another round of morning fog. A Dense
Fog Advisory has been issued for portions of Puget Sound and the
Southwest Interior due to the expected fog development. Fog is
already beginning to develop in isolated river valleys, and is
expected to further expand tonight into Sunday morning. 

High pressure building into the Pacific Northwest will maintain
dry conditions and seasonable temperatures through Monday, with
periods of morning fog and afternoon sun breaks. As the upper 
level ridge axis shifts eastward on Monday, ensembles continue 
to show low chances of rain generally along the coast and over 
the Olympic Peninsula.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...Chances for light rain 
continue into Tuesday as a splitting frontal system passes over 
the region. Wetter and more unsettled conditions are expected to
return on Wednesday and beyond as a series of systems are set 
to move over the region. While ensembles continue to show a fair
amount of variability heading into next weekend, the system 
Friday looks to be the strongest and will likely bring breezy 
winds alongside widespread lowland rain and mountain snow.

JD/15

&&

.AVIATION...Most locations across western Washington are VFR 
this evening. Areas of localized fog have begun to form around 
Olympia and the in the middle Chehalis river valley and will 
continue to expand and encompass much of the western WA 
lowlands. The highest confidence remains across the metro area 
south of Everett, through will also expand, at least briefly, 
towards HQM and BLI. This will bring widespread LIFR conditions 
through Sunday morning. Improvement to VFR expected after 
18-20Z. Northerly surface winds 4-6 kt becoming light and 
variable tonight into Sunday morning. 

KSEA...VFR conditions today. Conditions will deteriorate Sunday 
morning with LIFR fog expected to form at the terminal after 10Z-
12Z, through latest satellite trends indicate the potential for an 
earlier start. Conditions will improve to VFR after 18-20Z. NW winds 
will ease this evening becoming 5 kt or less into Sunday morning.

29/62

&&

.MARINE...Shower activity was decreased this afternoon across 
the coastal waters and the threat for brief waterspouts has 
ended. 

A surface low pressure will continue to dig south today. High 
pressure will build over the waters tomorrow through Monday. A 
system will approach the coastal waters to the north, leading to an 
increase in winds over the outer coastal waters on Monday. Latest 
guidance suggests there is a 55-70% chance for wind gusts briefly 
exceeding 21 kt Monday morning over zones PZZ170 and PZZ173. High 
pressure will move inland on Tuesday. The next system arrives 
Wednesday. Winds will increase across the coastal waters; however, 
latest probabilities indicate a 40-50% chance for wind gusts meeting 
small craft thresholds. A stronger system will impact the waters 
Thursday into Friday, bringing stronger winds across the coastal 
waters and interior waters, with latest probabilities at 65-75% for 
winds above 21 kt. 

Seas 4-6 feet this afternoon, decreasing below 5 feet tonight. Seas 
will build on Monday 7-10 feet and will hover around this range 
through late in the week. With the stronger system arriving Friday, 
latest guidance suggests seas will build  up to 13-16 feet. 

29

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Dense Fog Advisory from 1 AM to 10 AM PDT Sunday for City of 
     Seattle-Downtown Everett / Marysville Area-Eastern Kitsap 
     County-Eastside-Lowlands of Lewis and Southern Thurston 
     Counties-Lowlands of Pierce and Southern King Counties-
     Olympia and Southern Puget Sound-Shoreline / Lynnwood / 
     South Everett Area.

     Dense Fog Advisory until 10 AM PDT Sunday for Lower Chehalis 
     River Valley-Middle Chehalis River Valley.

PZ...None.

&&

$$

Southwestern Washington and Western Oregon

021 
FXUS66 KPQR 010549 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1049 PM PDT Sat Oct 31 2026

Updated Aviation Discussion...

.SYNOPSIS...Mostly clear skies and calm winds may bring frost 
and/or fog development across much of NW OR and SW WA in the 
mornings through Monday. Mostly dry conditions through Monday. 
Low chances for scattered showers Monday night, then 
precipitation chances increase later next week with limited 
weather impacts expected.

&&

.DISCUSSION...Through Friday...Visible satellite imagery early 
Saturday afternoon shows areas of fog/stratus across some 
inland valleys with mostly clear skies elsewhere. Afternoon 
temperatures are expected to warm into the mid- 50s, before 
quickly falling into the 40s after sunset this evening. The 
upper trough that has been spinning just offshore all week 
became elongated offshore overnight and is slowly pushing inland
today through tonight. This will bring a 20-40% chance of 
showers to mainly the Lane and Linn County Cascades and 
foothills this afternoon and evening, decreasing around 
midnight. Valley locations should remain dry with just some high
clouds overhead. 

Dry conditions continue Sunday into Monday as an upper level 
ridge of high pressure builds over the PacNW behind the trough 
passage. Skies are expected to clear after midnight tonight, 
which combined with calm winds is expected to lead to another 
round of widespread fog or low stratus across inland valleys 
Sunday morning. Radiational cooling is also expected under these
conditions, which will allow minimum temperatures outside of 
urban areas to cool into the mid to upper 30s. Fog/low stratus 
should dissipate by midday with sunny skies and high 
temperatures in the 50s. Expect a rinse and repeat of this 
forecast on Monday.

Today's 12z ensemble guidance has come into much better 
agreement on the overall weather pattern through midweek next 
week, though some uncertainty on specifics still exist. Guidance
indicates a low pressure system will develop in the eastern 
Pacific early next week as the high pressure moves inland over 
the PacNW. The majority of ensemble members indicate this low 
will move inland somewhere in northern CA or along the CA/OR 
border late Monday through Tuesday. Currently the forecast has a
10-25% chance of scattered showers Monday night into early 
Tuesday with very limited rain amounts, though depending on the 
strength and north to south extent of this low, these chances 
could decrease in subsequent forecasts. Tuesday through most of 
Wednesday look to dry out with temperatures warming to near 60 
degrees for the interior lowlands. Then precipitation chances 
increase again late Wednesday into Friday as ensemble members 
indicate another front or two could bring a couple more rounds 
of moisture to the area. At this point, no significant 
precipitation impacts are expected with any of these weather 
systems, though there's a 25-50% chance of wind gusts increasing
over 30 mph along the coast (5-20% chance inland) with each 
frontal passage late in the week. -03

&&

.AVIATION...Through 06Z Monday...Currently mostly VFR across the
airspace with northward-moving mid to high level clouds gradually
breaking and shifting east of the Cascades due to high pressure
aloft. With skies gradually clearing through 9-13Z Sun, expect 
increasing chances for fog development. KAST and KUAO have already
begun to experience deteriorated conditions, currently with MVFR 
to IFR visibility. After 9-13Z Sun, expect fog to develop at most 
inland terminals, with the least confidence for fog at KTTD. 
Probabilistic guidance currently suggests a 20-50% chance of LIFR 
conditions between 09-20Z Sun, with the highest chances, earliest
occurrence, and longest duration at terminals within the southern
Willamette Valley. Specifically, most terminals will improve back
to VFR by 18-19Z Sun, while KSLE and KEUG may remain under 
deteriorated conditions until 20-21Z Sun. Winds will remain 
generally light and variable through the TAF period, further 
favoring fog development overnight. Light easterly wind at coastal
terminals will likely limit conditions to VFR, with only a 15-25%
chance of MVFR conditions between 10-18Z Sun.

KPDX AND APPROACHES...Currently VFR conditions with mid to high
level clouds gradually clearing towards 13Z Sun. Clearing skies
will bring favorable conditions for fog development, prompting
probabilistic guidance to suggest a 20-30% chance of LIFR VIS
anytime between 12-18Z Sun. VFR conditions will return by 18-19Z
Sun. Generally light and variable winds through the TAF period.
~12

&&

.MARINE...Weak low pressure offshore gradually dissipates today as
winds decrease below 10 kt. Seas around 4 to 5 ft continue to 
subside to 3 to 4 ft into Sunday morning. Offshore winds develop 
late Sunday night and persist into early next week. A long period
west-northwest swell also arrives Sunday evening, building seas 
to around 7 to 9 ft at 16-19 seconds on Monday. Chances for seas 
over 10 ft on Monday remain at around 30-50% across the outer 
waters. This long period swell will result in a moderate threat 
for sneaker waves at the coast Sunday evening through Tuesday. 
Caution should be used at beaches when in or near the water. 

A weak low pressure system approaches the waters mid next week, 
returning light southerly winds. By the end of the week, model 
guidance hints at a stronger system entering the waters, resulting
in a 60-80% chance for maximum wind gusts exceeding 21 kt on 
Friday with a 30-50% chance for seas exceeding 15 ft.     -10/DH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...Dense Fog Advisory from 1 AM to 10 AM PDT Sunday for ORZ108-109-
     111-112-114>118.

WA...Dense Fog Advisory from 1 AM to 10 AM PDT Sunday for WAZ204>207.

PZ...None.

&&

$$

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Southeastern Washington and Northeastern Oregon

025 
FXUS66 KPDT 010537
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1037 PM PDT Sat Oct 31 2026

.KEY MESSAGES...
- Near- to below-normal temperatures into next week.

- Precipitation this evening into Sunday morning, mainly for 
  eastern Oregon and far southeast Washington.

- Low chance (30% or less, except for freeze-prone areas) of a 
  season-ending freeze for the eastern Columbia River Gorge 
  Monday.

&&

.DISCUSSION...
Composite reflectivity showed a few showers popping off the NW 
Blue Mountains of Washington, near Walla Walla as well as 
elevated echoes over Franklin county early This Afternoon. Radar
returns were still sparse over the Oregon Cascades where 
initial probabilities associated with the incoming synoptic 
system for Tonight were found. Elsewhere, dense fog resulted in 
limited visibility to a quarter mile or less during the morning 
to early afternoon hours across the upper end of the Kittitas 
valley, the Walla Walla Valley as well as the Foothills of the 
Northern Blue Mountains. Based on mesonet observations and 
roadcam networks, these areas have improved visibility to at 
least 2 miles or better. REFS trends for precipitation Tonight 
suggest around a tenth and up to a quarter of an inch of liquid 
equivalent precipitation across the central Oregon 
mountains/Oregon Cascades through about the middle of the 
overnight hours. And meanwhile these trends have tended to 
reduce QPF amounts in the last few days for the northern Blue 
Mountains, where the mean QPF across the Blue Mountains and 
Wallowas on average is up to a tenth of an inch (30 to 50% 
confidence) with REFS QPF max amount over the Eagle Caps upwards
between a quarter and one half inch of liquid equivalent. Rain 
snow mix is possible higher than 6500 ft, however the REFS only 
offers about a half inch over the Oregon Cascade crest and one 
to two inches on the Eagle Caps. Sunday ultimately winds up 
being slightly warmer for parts of the forecast area like the 
Yakima Valley, and Lower Columbia Basin with abundant insolation
and light westerly surface winds  and highs in the upper 50s 
to low 60s in the Yakima and Columbia River Gorge. 

The upper ridge develops Monday behind the exiting mid level 
trough, redistributing the light westerly wind field to light 
northeast across the Basin and potentially turning winds 
southerly and breezy in the Grande Ronde Valley by Overnight 
into Tuesday morning. Overnight low Temperatures through the 
eastern Columbia River Gorge still appear mild and above 
freezing over the next 7 day as to think at least at this time, 
low confidence exists in any anticipated freeze headlines for 
these last remaining last warning eligible zones, at least for 
the first week of November.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...MVFR or lower
conditions expected to impact some sites through the period.
Short-term high-res guidance does indicate a return of CIGS AOB
2kft AGL at sites PDT/RDM/BDN/ALW tonight into tomorrow
afternoon. Wind shifts to the northwest at site PDT and shifts
to the south southwest at site ALW will coincide with lowering
CIGs. Confidence is low (15-20%) in vsby reductions occurring 
at sites PDT/RDM/BDN/ALW throughout the night so have not 
included in current TAFs. Otherwise, site PSC will see a CIG 
reduction to around 3.5kft AGL overnight. VFR conditions to 
prevail at sites DLS/YKM through the period. Winds will be 
light, 12kts or less, through the period. Lawhorn/82

&&

.Preliminary Point Temps/PoPs...
PDT  34  53  31  57 /  20  20   0   0 
ALW  38  52  35  56 /  40  20   0   0 
PSC  33  59  30  56 /  10  10   0   0 
YKM  32  60  29  55 /  10   0   0   0 
HRI  32  57  31  56 /  10  10   0   0 
ELN  27  56  25  52 /   0   0   0   0 
RDM  25  51  21  57 /  20  10   0   0 
LGD  36  52  29  56 /  30  30   0   0 
GCD  35  50  30  58 /  20  10   0   0 
DLS  36  60  33  57 /  10   0   0   0 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
WA...None.
OR...None.

&&

$$

DISCUSSION...71
AVIATION...82

Northeastern Washington and Northern Idaho

714 
FXUS66 KOTX 010548
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1048 PM PDT Sat Oct 31 2026

.KEY MESSAGES...

- Cool temperatures, light winds, and 20-50% chance of light
  rain Sunday morning in southeast Washington and southern Idaho
  Panhandle. Light rain accumulations up to a tenth of an inch .

- Dry conditions Sunday evening through Wednesday.

&&

.SYNOPSIS...
Mid and high clouds bring a small chance of sprinkles and 
showers to southeastern Washington and north Idaho through 
Sunday morning. Drier air arrives Sunday afternoon and 
conditions remain seasonal and dry through Wednesday. Mountain 
snow showers return mid to late week. 

&&

.DISCUSSION...
Sunday through Wednesday: The upper level that was offshore finally
moves into northern California tonight, bringing clouds and 
light rain to southeast Washington and the southern Idaho 
Panhandle. Because the best dynamics are shifting south, the 
chance for substantial rain tonight is decreasing. There is a 
10-30% chance of 0.10” or more of rain through Sunday afternoon 
for the Palouse, foothills of the Blue Mountains, L-C valley, 
and Camas Prairie. Dry air filters in from the west during the 
day behind the base of the shortwave trough, which will lead to 
very sunny skies filtering into most of the region except 
lingering low stratus in southeast Washington and the central 
and southern ID Panhandle. There will be a risk for fog Sunday 
night with clear skies across the region. Forecasting fog is a 
low confidence endeavor but high resolution models are hinting 
at fog development on the northern Palouse and chances 
increasing to the north and west overnight. Monday through 
Wednesday afternoon remains quiet and dry with near normal 
temperatures in the upper 40s to mid 50s. 

Wednesday night through Sunday: A couple of waves will move
through the region mid to late week, bringing the potential for
rain and mountain snow. From 4 AM Thursday to 4 AM Saturday, 
there is a 5-10% chance of 4+ inches of snow for Stevens Pass 
and Lookout Pass and a 30% chance for Washington Pass. The Gulf 
of Alaska longwave trough remains firmly anchored into next 
weekend with shortwaves pivoting around it, favoring ridging 
building into our area which would favor drier conditions in 70%
of the global ensemble. This does not mean it would be 
completely dry, especially the Cascades. 30% of the global 
ensemble resembles a dirty ridge with deeper troughing in the 
northeast Pacific and displaced further east towards the Pacific
northwest. Overall, the next week is drier than we would like 
to see for the start of November. /DB

&&

.AVIATION...
06Z TAFS: Clouds have overspread the Inland Northwest and rain
has starting falling over KPUW and KLWS. There is a 20-30%
chance of reaching KGEG-KSFF by 08Z but confidence is low. Overall,
conditions are expected to remain VFR except for KPUW. Upslope 
westerly flow into KPUW has lead to ceilings dropping to 
LIFR/IFR earlier than expected. There is a 60% chance this 
persists until 20z. With continued westerly flow, it would not
surprise me if KPUW does not clear out at all before
southeasterly winds increase overnight after 06z. Rain will
depart KPUW-KLWS by 18Z Sunday. Dry air will filter in bringing
sunny skies elsewhere. 

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence
in IFR ceilings for KPUW. Confidence remains moderate to stay
IFR through Sunday afternoon and evening. High confidence in 
VFR conditions elsewhere.

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

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

&&

.Preliminary Point Temps/PoPs...
Spokane        38  51  33  52  35  53 /  30  10   0   0   0   0 
Coeur d'Alene  38  52  33  51  35  53 /  20  10   0   0   0   0 
Pullman        36  48  32  51  35  52 /  30  30   0   0   0   0 
Lewiston       42  53  38  55  39  56 /  30  40   0   0   0   0 
Colville       32  51  27  51  26  53 /  30  10   0   0   0   0 
Sandpoint      35  50  32  49  32  51 /   0  10   0   0   0   0 
Kellogg        37  51  34  51  35  54 /  10  20   0   0   0   0 
Moses Lake     35  54  29  55  34  57 /  10   0   0   0   0   0 
Wenatchee      36  52  34  52  40  56 /   0   0   0   0   0   0 
Omak           35  51  31  52  36  55 /  10   0   0   0   0   0 

&&

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

&&

$$