264 FXUS66 KSEW 091952 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 915 AM PDT Tue Oct 9 2018...corrected version .SYNOPSIS...Showers will taper today as a weather system exits. The rest of the next week looks dry with high pressure aloft in control. Lingering low level moisture and light winds will produce some night and morning fog through Friday. Increasing offshore flow for the weekend will likely limit the fog coverage. && .SHORT TERM...WV satellite imagery show the closed 500 mb upper low circulation migrating slowly east over WA/Oregon and Idaho. Some wrap around moisture is still producing a few showers over the Cascades but activity is generally decreasing. The convergence zone between Seattle and Tacoma is also weakening. Most showers should end by afternoon as the low continues to shift east. Model time- height and MOS guidance all point toward gradual improvement this afternoon with partial sunshine expected, and some area of clearing to the north. Highs will remain cool with north flow keeping highs mainly in the mid to upper 50s. Mid and upper level clouds will decrease tonight into Wednesday, and mostly clear out by Thursday. Residual low level moisture will be slower to clear out and should lead to some areas of fog during the late night and morning hours Wednesday through the end of the week. Fog prone valleys may hold onto fog later into the afternoon which could result in somewhat cooler high temperatures than more exposed spots. Much of the greater Puget Sound and other interior areas will have more afternoon sunshine each day with highs reaching the low or mid 60s. Mercer .LONG TERM...Previous discussion...An upper ridge will remain over the area Friday through Monday with northerly low level offshore flow for dry weather and seasonable temperatures. Models show a weak weather system brushing the area to the north Thursday night and Friday. This might bring some sprinkles to the north part of the area but for now the forecast is dry. Schneider && .AVIATION...Moderate to strong northwest flow today as cold front shifts southeast of the region. A few gaps in the clouds have appeared this morning with conditions bouncing around between VFR and IFR as air mass remains very moist. Gradual drying expected throughout the day today with ceilings lifting later this afternoon or early evening back to VFR. Improvement will be short lived though as light surface gradients, recent rainfall, and longer nights will allow for fog development after 09-10z. Widespread IFR or LIFR conditions expected for much of the region through Wednesday morning. KSEA...Above discussion applies. Ceilings may bounce around between VFR and MVFR through the early afternoon hours as air mass remains moist. Improvement expected by the afternoon to early evening hours. Breezy north winds (with a few gusts to 20 kts) will continue through around 21z this afternoon before dropping off to 10 kts or below. Low clouds and fog will return tonight with IFR to LIFR conditions a good bet after 10z. Light and variable winds overnight into Wednesday morning. CEO && .MARINE...Strong northwesterly winds continue over the coastal waters this morning in the wake of departing cold front. Small craft advisory remains in place through this evening. High pressure will build into the waters later today and continue through Thursday. This will result in lighter winds and areas of fog. Winds should be 20 kts or less. CEO && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until midnight PDT tonight 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. Small Craft Advisory until noon PDT today for Coastal Waters From Cape Flattery To James Island Out 10 Nm-Coastal Waters From James Island To Point Grenville Out 10 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm. && $$ www.weather.gov/seattle