903 FXUS66 KSEW 132303 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 303 PM PST Mon Jan 13 2025 .SYNOPSIS...High pressure over Western Washington will bring multiple rounds of morning fog and low stratus over the next few days. A weak system midweek will bring precipitation chances on Thursday. Cooler and drier conditions return for the weekend and early next week. && .SHORT TERM /TONIGHT THROUGH THURSDAY/...Some improvement was seen across some locations in Western Washington today, as the fog and low stratus managed to erode, giving way to some partly cloudy skies. However, some locations struggled throughout the day. A similar pattern can be expected over the next few days as an upper level ridge situated over the region will bring multiple rounds of morning fog and low stratus. Late Wednesday night a shortwave trough will descend towards British Columbia, bringing light precipitation (lowland rain and mountain snow) chances on Thursday. Based on model guidance, this system will be relatively weak with no significant impacts expected. Most of the precipitation will be centered around the Northern and Central Cascades. The lowlands may see a stray shower or two with this system. Increased cloud cover and winds will likely provide some relief from the morning fog on Thursday morning. The deterministic NBM is showing a small chance at some light rain/snow mix along parts of the interior lowlands late Thursday night into Friday morning. Confidence is high that temperatures will be near freezing; however confidence is very low on any precipitation accumulating due to low PoPs at this time. .LONG TERM /FRIDAY THROUGH MONDAY/...A cooling trend is set to ensue starting on Friday and will get colder throughout the weekend. High temperatures on Friday will peak in the low 40s. By the weekend, temperatures will likely struggle to go above 40 degrees. Low temperatures on Friday will be in the low 30s across the lowlands. By the weekend, low temperatures are expected to decrease into the mid 20s. It is possible that a Cold Weather Advisory may need to be issued in the next coming days for some portions of Western Washington, as some models are already hinting at apparent temperatures being near/within threshold criteria. An upper level ridge will rebuild off the Pacific during the weekend likely keeping Western Washington dry for the remainder of the weekend and early next week. Temperatures and precipitation are looking to trend below normal, according to the Climate Prediction Center`s 6-10 Day Outlook. MGF && .AVIATION...Strong high pressure remains over the region for dry and stable weather. Light winds and poor mixing will trap low level moisture near the surface for IFR to LIFR conditions. Slow lift of the stratus on Tuesday but ceilings likely remaining in MVFR range. 33 KSEA...IFR to LIFR conditions through 20z Tuesday with N/NE winds 5 kt or less. 33 && .MARINE...High pressure will remain over the waters through the majority of the week. Expect 10 foot seas over the outer coastal waters through Wednesday. A weak front will move across the waters Thursday into Friday for increasing north winds. 33 && .HYDROLOGY...River flooding is not expected through the next seven days. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 6 PM PST Tuesday for Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-Coastal Waters From James Island To Point Grenville 10 To 60 Nm- Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm. && $$