textproduct: Seattle/Tacoma

SYNOPSIS

A weak front will pass through today for a few showers across the coast, Olympics and Cascades. A ridge will build over the region through the end of the week for another round of warm and dry conditions. The pattern flips to unsettled this weekend and early next week as a couple of systems pass through.

SHORT TERM /TODAY THROUGH FRIDAY/

A cold front will weaken as it shifts E/SE into western WA today. Expect isolated to scattered showers mainly over the coast and mountains this morning.

High pressure and offshore flow will lead to drier and warmer weather Thursday and Friday. Expect highs on Thursday in the lower 70s with 60s near the water. Offshore flow will strengthen Thursday night with gusty east Cascade gap winds of 20-30 MPH. Friday will be slightly warmer in the interior with highs in the mid 70s. 33

LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/

Friday night and Saturday will be cooler and wetter as a cold front and trailing trough push into western WA. Showers with a convergence zone are likely Saturday afternoon/evening near the King/Snohomish line. High will be cooler and in the 50s and 60s Saturday afternoon. Expect cooler lows Sunday morning with 30s around the south sound. The system slated for Sunday and Monday is now shifting south over the offshore waters, missing WA, with lower probabilities of seeing gusty winds. The air mass will still be cool and showery with a trough overhead, though. Expect a chance of showers moving into Tuesday before the trough exits. 33

AVIATION

A weak frontal system will continue to bring light rain showers across portions of western Washington through late this morning as it traverses the area. In addition to rain, ceilings are a bit of a mixed bag ranging from IFR to VFR. Ceilings will likely continue to slowly lower early this morning, with mostly continuing MVFR conditions across the interior, with IFR to LIFR conditions along the coast. Ceilings will slowly lift and scatter late morning/early afternoon (between 18-21Z) across the interior, and may not fully scatter along the coast until after 00-03Z Thur this evening. Light winds and clearing skies tonight will allow for low stratus/fog development going into early Thursday morning.

Winds remain southwesterly 4-8 kt and will become light/variable before switching to northerly, 5 kt or less, by around 00Z Thur.

KSEA...MVFR ceilings early this morning with a 10% chance of brief IFR conditions as rain showers move through early this morning. Ceilings look to lift to VFR after around 18Z this morning and slowly scatter into the early afternoon. Clearing skies and light winds will allow for fog/low stratus to develop, with a 25-35% chance of LIFR conditions after 12Z Thur. SW winds 4-8 kt will become light before switching to N/NE up to 5 kt after 00Z Thur.

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MARINE

A weak front will traverse the area waters early this morning. High pressure will quickly build in across the offshore waters tonight, with thermal troughing developing along the coast. This will allow for winds to turn offshore tonight into Thursday. While winds are favored to remain below any thresholds for headlines, there will be some enhancement to the winds through the gaps, with a 20-40% chance for gusts to exceed 20 kt near the west entrance to the Strait of Juan de Fuca and around Grays Harbor. Winds will ease on Friday as the thermal trough gets pushed inland by an incoming frontal system. Onshore flow will start to increase as a frontal system traverses the area Friday night into Saturday. Another low may follow suit Sunday into Monday but there are significant differences in the exact low track.

Seas remain around 4 to 7 ft through Friday, increasing through the weekend. The most likely forecast is around 8 to 10 ft, though seas could reach as high as 13-16 ft Sunday into Monday, depending on the track of the low pressure systems as the move across the northeast Pacific. GEFS is showing 40-50% chances of seeing greater than 12 ft during that time frame.

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SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...None.