


Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA
Issued by NWS Seattle/Tacoma, WA
767 FXUS66 KSEW 160315 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 815 PM PDT Wed Oct 15 2025 .UPDATE...Mostly clear skies remain in place of western Washington this evening with lowland temperatures already in the 40s to lower 50s. Inherited forecast remains on track for quiet conditions to persist into Thursday. The Aviation section below has been updated. && .SYNOPSIS...Clouds will increase and a little rain will reach Western Washington Thursday night into Friday as a weak frontal system moves through the area. A stronger system will move into the region over the weekend bringing gusty winds, lowland rain, and mountain snow. Unsettled conditions will continue into early next week. && .SHORT TERM /TONIGHT THROUGH SATURDAY/...The upper level ridge offshore will begin to flatten tonight and allow a weakening frontal system to reach the area Thursday night into Friday. QPF will be minimal with this one...a few hundredths interior lowlands to a quarter to half inch coast and mountains. This will open the door for a stronger system to arrive over the weekend. .LONG TERM /SUNDAY THROUGH WEDNESDAY/...A more vigorous front arrives Saturday night into Sunday. Snow levels will bump up to 7500 to 9500 feet in the warm sector ahead of the cold front, but this will be relatively brief with snow levels falling back to 4500 to 5000 feet behind it on Sunday morning. It will be a noteworthy early season system with QPF totals ranging from around three quarters of an inch in the Olympic rain shadow to 3 or 4 inches in the Olympics and North and Central Cascades. Though this is a good primer for area rivers, the antecedent dry conditions lend little concern for any flooding at this time. Standard breezy to locally windy conditions will apply with the system. The trailing upper trough will waste little time coming onshore with weak upper ridging leading to some drying Sunday night into Monday. Forecast confidence in the details falls off Tuesday and beyond with clusters/ensembles showing quite a spread in solutions. A couple of weaker systems may brush the area Tuesday into Wednesday, but upper ridging centered to our south may act to blunt their impacts. 27 && .AVIATION...Weak flow aloft as a transient ridge moves southward tonight into Thursday. Terminals are VFR this evening with winds decreasing (becoming calm or variable 2-4 kt as winds will turn more southerly in most areas around midnight local time). Flow will turn more onshore tonight into tomorrow. However given the weak gradient tonight (combined with the dry weather past few days), the push of stratus/fog will likely be limited from the coast to as far inland as the south interior/Kitsap areas (12-15Z start to as late as 18Z). Most terminals outside of this area tonight will remain VFR with mid level clouds filling in with light scattered rain showers likely Thursday evening. Ceilings will gradually lower with these showers from VFR down to MVFR going into Friday morning. Winds will remain out of the south 4-8 kt going through Thursday. KSEA...VFR likely remaining through the TAF period. While chance of IFR/LIFR are low, there still remains a medium chance of MVFR cigs in the morning briefly from roughly 14Z through 17Z in the morning. The dry conditions and weak onshore gradients tonight will most likely keep lower CIGs/VIS to the west of the terminal (with only 2 out of 11 HREF members mentioning anything low near the terminal). VFR mid level clouds are favored for the rest of the day with the front passing, with low confidence in showers passing through the terminal later (but high enough probability to put a PROB30 group with the 06Z TAFs). Winds have calmed this evening - will turn south by midnight and pick up 4-8 kt during the day Thursday. HPR && .MARINE...A weak front will arrive Thursday night into Friday with a modest increase in coastal seas but no impacts are expected. A stronger frontal system will reach the waters Saturday night into Sunday with headlines expected for most of the waters. Coastal seas will build into the double digits this weekend and could exceed 15 feet by later Sunday and remain above 10 ft into early next week. McMillian/27 && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...None. && $$