textproduct: Seattle/Tacoma

SYNOPSIS

Upper level ridge over Western Washington through Thursday shifting east Thursday night. Dissipating front trying to move into the area later Friday into Saturday morning. Another upper level ridge builds Saturday afternoon into Sunday. Low level flow turning onshore today with varying degrees of onshore flow through most of the week.

SHORT TERM /TODAY THROUGH WEDNESDAY/

Satellite imagery shows stratus surging up the coastline has reached the Grays Harbor/Pacific county border at 2 am/09z. A few high clouds over the remainder of the area. Temperatures were in the 50s and lower 60s.

Stratus will continue moving up the coastline reaching the North Coast this afternoon. Outside of the Grays Harbor area the stratus will remain near the beaches. Light flow in the lower levels this morning becoming onshore later this morning into the afternoon. The marine layer will be too shallow to get east of Puget Sound with highs similar to Sunday's readings, in the 70s and lower 80s. The marine air will filter into the Lower Chehalis Valley, Southern Hood Canal and portions of the Southwest Interior cooling highs about 5 degrees from yesterday. Highs in these locations in the 70s to lower 80s as well. Significant cooling along the coast with highs in the mid to upper 60s. Warmer temperatures along the North Coast.

Low level onshore flow peaking tonight with the marine layer getting into the Puget Sound area by early Tuesday morning. Lows in the mid 40s to mid 50s.

Onshore gradients going light during the day Tuesday with the marine layer retreating to the coastline by afternoon. The weak marine push will lower highs by about 5 degrees over the interior, into the upper 60s to mid 70s. Marine layer remaining intact along the coast keeping highs in the lower 60s.

Little change in the pattern Tuesday night into Wednesday with an upper level ridge over the area and light low level onshore flow. Lows in the mid 40s to mid 50s. Highs Wednesday a little cooler again over the interior, mid 60s to lower 70s while along the coast highs near 60. Felton

LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/

Extended models still showing good consistency. Upper level ridge over the area Wednesday night and Thursday shifting east Thursday night. Dissipating negatively tilted front falling apart over Western Washington later Friday into Saturday morning. Slight chance of showers in this window. Another upper level ridge building over the area Saturday afternoon into Sunday. Highs in the 60s and lower 70s Thursday cooling into the upper 50s to mid 60s Friday. Warming trend for the weekend with 60s and lower 70s Saturday and mid 60s to mid 70s Sunday.

AVIATION

North to northeast flow aloft continues with an upper ridge located offshore. Low level onshore flow will increase today with IFR/LIFR stratus reaching most of the coast this morning. VFR conditions will prevail across the interior today. Stratus will spread into the interior late tonight with IFR conditions expected across much of the interior lowlands on Tuesday morning.

KSEA...VFR today. IFR stratus expected to return around 12Z-14Z Tuesday. Surface wind light and variable becoming W/SW 7 to 10 knots this afternoon then light southerly tonight.

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MARINE

A thermal trough will shift inland today for a return to onshore flow. Varying degrees of onshore flow will then persist through the week as a surface ridge remains anchored offshore with lower pressure inland. Small craft advisory westerlies are likely in the central/east strait each of the next several afternoons and evenings.

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HYDROLOGY

No river flooding in the next 7 days.

SEW WATCHES/WARNINGS/ADVISORIES

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