textproduct: Seattle/Tacoma

SYNOPSIS

High pressure will remain situated offshore through much of next week, maintaining near-normal temperatures across western Washington with cloudy mornings and sunshine in the afternoons. A few weak systems will move over the top of the ridge towards the middle of next week, bringing little more than a few periods of sprinkles.

SHORT TERM /TODAY THROUGH TUESDAY NIGHT/

A high pressure ridge will continue to build offshore throughout the short term, bringing northwest flow aloft and onshore flow at the surface to western Washington. This will bring more spring-like conditions to the region, with temperatures through Tuesday peaking near normal generally in the 60s. In addition, onshore flow will allow marine stratus to expand inland each morning, breaking up for most areas by the afternoon. A splitting frontal system will attempt to overrun the ridge on Tuesday, but will likely bring little more than a few sprinkles to the area.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Wednesday will see more of the same, with potential for a cloudy morning, mostly sunny afternoon, and mild temperatures peaking in the 60s to lower 70s.

By Thursday, the upper level ridge offshore will begin to flatten as a low pressure system slowly strengthens and lowers from the Gulf of Alaska. Conditions are favored to remain dry into the first half of the weekend as zonal flow sets up aloft, with continued mild temperatures.

Ensembles are honing in on a potential pattern change by the end of next weekend, with increasing chances for accumulating rainfall over the North Cascades on Saturday. However, the details remain uncertain at this time.

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AVIATION

High pressure under a ridge will build along the coast today into Monday. The flow aloft will decrease out of the north tonight as the ridge axis passes overhead. Cloud coverage continues to decrease this afternoon from west to east. Terminals outside of the Cascades have become VFR with few or scattered deck. Given the current synoptic setup into Monday, a marine push of stratus inland is likely in the morning. Highest probabilities for MVFR ceilings is from the Kitsap Peninsula westward, with chances decreasing (but remaining elevated) for the Puget Sound terminals Monday morning. Additionally, there is some potential again for fog/mist under the clouds for the Kitsap/South Interior terminals (but this is lower confidence due to the cloud coverage). Ceilings Monday afternoon will retreat towards the coast (but likely remain along the immediate coastline). Winds outside of the interior terminals will remain northwest 5-10 kt (couple gusts to 20 kt near the Strait of Juan de Fuca). North Interior/Puget Sound winds both afternoons will favor the northwest 5-10 kt, with winds returning to the south under 5 kt overnight.

KSEA...VFR with few or scattered clouds this afternoon through tonight. Stratus likely to reach interior Monday morning. Lower-end VFR is favored, but there is a 40% chance the ceilings may get down into MVFR criteria in the morning, before clearing early Monday afternoon. Winds to increase out of the north this afternoon 5-10 kt, returning to the south under 5 kt overnight, before returning to the north again early Monday afternoon.

HPR

MARINE

High pressure will continue to build offshore through much of the next week. This will generate a Small Craft westerly push through the central and eastern Strait of Juan de Fuca tonight, as well as daily pushes of westerly winds through the Strait of Juan de Fuca through much of the coming week. A splitting frontal system will move across the area waters Monday into Tuesday, before high pressure builds back in its wake on Wednesday. Another weak frontal system looks to move into the area waters on Thursday.

Seas around 6 to 8 feet today will build to 8 to 10 feet on Monday, remaining near 10 feet through Wednesday. Seas will build to 10 to 13 feet by late Thursday and hover around 10 feet heading into next weekend.

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HYDROLOGY

The daily hydrology discussion has ended until the start of the next rainy season; it will only be updated during this time as needed.

SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory from 5 PM this afternoon to 5 AM PDT Monday for Central U.S. Waters Strait Of Juan De Fuca- East Entrance U.S. Waters Strait Of Juan De Fuca.