084 FXUS66 KSEW 162157 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 257 PM PDT Mon Sep 16 2024 .SYNOPSIS...Weak ridging over the area today for general benign conditions. A upper level trough and associated front will push through the region late Tuesday for some rain showers into Wednesday. Drier conditions into Thursday before unsettled weather likely returns to the area through the weekend. && .SHORT TERM /TONIGHT THROUGH THURSDAY/...Recent satellite imagery shows dissipating stratus clouds from this morning leading to mostly clear skies this afternoon. High temperatures this afternoon will remain near normal, in the mid 60s to lower 70s across the area. Clear skies will continue to trend into tonight with some high level clouds moving ahead of an approaching system, with some patchy fog likely in the lower prone areas. An upper level trough and associated front will start to approach the coastal areas by Tuesday morning and will start to spread rain showers inland by the afternoon. Latest ensembles show a strong jet jet digging southward which could slow down and weaken the front as it approaches western Washington. Regardless, there will be plenty of cloud cover around with light rain showers across the area. Low temperatures Tuesday night will hover in the 50s. The front will dissipate over the area into Wednesday with lingering showers, as weak northerly flow will keep our region somewhat dry into Thursday. High temperatures will continue to remain in the low to mid 60s. .LONG TERM /FRIDAY THROUGH MONDAY/...Confidence in the long term continues to wobble as ensembles attempt to agree on a solution. Latest guidance indicates a weak disturbance passing through the area on Friday which would keep showers in the forecast. The GFS continues to highlight an upper level ridge into the weekend, meanwhile the ECMWF highlights multiple systems with plentiful moisture into the beginning of next week. The latest trends have been pushing more towards the more wet solution, of multiple systems transversing across the Pacific Northwest, which could really open up the door to fall. Will keep chance of showers in the forecast for now and will see how the models evolve. Mazurkiewicz && .AVIATION...Light east to northeast flow aloft will become westerly late tonight as another upper trough and associated frontal system approach the region. At low levels, increasing onshore flow will result in widespread low MVFR to IFR ceilings along the coast by 07Z then spreading across Western Washington by 14z Tuesday morning. KSEA...VFR conditions will linger though the evening with stratus and MVFR ceilings expected to develop by 14Z. NW surface winds 5 to 7 knots this afternoon will become light NE during the late evening before backing to south/southwesterly late tonight. && .MARINE...A broad surface ridge remains centered well offshore with lower pressure over the interior. Onshore flow will increase somewhat this evening. Strongest winds expected in the central/east strait tonight, with high resolution ensembles continuing to show only a 15-20% chance of reaching small craft criteria. The surface ridge over the offshore waters will weaken tonight and a trough and associated front will shift into the coastal waters on Tuesday. This system is unlikely to generate any headlines. The trough will weaken as it gradually shifts southward into the Oregon coastal waters on Wednesday. High pressure rebuilds offshore late in the week before another front is expected over the upcoming weekend. 27/cook && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...None. && $$
NWS SEW Office Area Forecast Discussion
