textproduct: Seattle/Tacoma

SYNOPSIS

Upper level troughing will continue to bring onshore flow and cooler temperatures through midweek. A weak system will bring light rain today into Wednesday. A stronger system will bring more widespread rain and slightly cooler temperatures to the area Thursday and Friday. Unsettled conditions continue over the weekend with likely additional precipitation.

SHORT TERM /TODAY THROUGH THURSDAY/

Recent satellite imagery shows low stratus spreading throughout the interior as southwest onshore flow continues over the area. Expect morning clouds to start to dissipate by the mid afternoon hours, with a mix of sun and mid level clouds the rest of the day. High temperatures will warm up in the mid to upper 60s, with areas in the Southwest Interior being a touch warmer, maybe in the low 70s.

A weak disturbance will cross over the area into Wednesday, with a chance of showers across the area, especially in the morning. Most of the area will remain dry as this system is rather weak. High temperatures remaining generally in the mid 60s for much of the interior, with locations along the coast seeing the influence of onshore flow, with temps in the low 60s.

Ensembles continue to be in agreement with a slightly stronger and wetter frontal system Thursday into Friday. Widespread rain will spread throughout the interior by Thursday afternoon and evening, with areas in the Cascades and Olympics seeing the bulk of the precip. With this frontal system, snow levels will lower to 6000 to 7000 feet, with some higher elevation peaks seeing their first dusting of snow for the season. High temperatures Thursday will cool, with most areas seeing upper 50s to lower 60s.

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/

Rain will continue on Friday and become more scattered in nature later in the day, with cooler temperatures in the upper 50s to low 60s continuing. Upper level troughing continues over the weekend, with additional chances of precipitation and cooler temperatures. There is still some uncertainty in ensembles, but for now, it looks like fall weather is here.

Mazurkiewicz

AVIATION

A weak cold front will move through the terminals this morning, with minimal precipitation (few areas of drizzle and an isolated shower post-front in northern Puget Sound this morning up to the north interior). MVFR ceilings (with isolated pockets of IFR ceilings and mist) will continue to increase in coverage this morning, peaking from 14Z-18Z, and likely lasting through 20-21Z before improving to VFR in the afternoon. Ceilings Wednesday morning are favored either in low-end VFR or MVFR, with fewer pockets of IFR. Variable/northeast winds this morning under 5 kt will transition to the southwest in the afternoon 4-8 kt (expect higher winds in the Strait of Juan de Fuca).

KSEA...LAMP guidance favors MVFR development from 12-14Z (already in progress at neighboring KBFI to the north), likely lasting through 20-21Z before improving to VFR for the remainder of the period. Variable/light northeast winds this morning will switch to the southwest this afternoon 4-8 kt.

HPR

MARINE

This morning's west push through the Strait of Juan de Fuca will weaken as a cold front has progressed through most of the waters. A weaker push is likely to occur this afternoon, although confidence remains low in wind gusts exceeding 20 kt for most of the Strait of Juan de Fuca (except for a small portion of the central strait on the Canadian side). An additional front will pass through tonight into Wednesday with little to no impact expected. A stronger system will move through Thursday into Friday with more precipitation, as well as an increased likelihood of seeing winds/wind gusts over 20 kt in the coastal waters and Strait of Juan de Fuca. An additional system late into next weekend does not appear likely at this time to produce hazardous winds to the waters.

Seas 6 to 8 feet today with isolated pockets of 9 feet but with longer northwest periods of 10 to 12 seconds. Seas drop back to 6 to 8 feet through the remainder of the forecast.

HPR

SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory until 3 AM PDT early this morning for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca.