textproduct: Seattle/Tacoma

SYNOPSIS

Warm, sunny conditions this afternoon. A frontal system will traverse the area tonight into Saturday, bringing chances for rain early and gusty winds. Cooler temperatures are in store for the weekend with localized frost potential. The next system looks to arrive Tuesday for the next round of rain chances and breezy winds.

SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/

A few patchy low clouds are lingering across portions of the waters across the area, as well as the immediate coastline and portions of the south Puget Sound, but these clouds will continue to diminish this afternoon for mostly sunny skies. Temperatures will vary depending on the time of clearing, with temperatures varying from the low 60s along the coast to low 70s in places with the most clearing. Seattle will likely reach the upper 60s.

Clouds will increase this evening as a frontal system traverses the area overnight into early Monday. A fairly-quick hitting band of rain will traverse the area in associated with the front. Behind the front, most of the remaining chances for rain in the mountains and in a convergence zone over the central Puget Sound for much of the day on Friday. Rainfall amounts will be light with most areas seeing less than a quarter to a half inch of rain. Some places in the south Sound could remain mostly dry and shadowed.

In addition to rain, winds will increase early tomorrow morning, peaking in the late morning/early afternoon timeframe. Winds will begin as southwesterly before becoming more westerly behind the frontal passage. Convergent flow is expected through the afternoon as winds turn north from the east entrance to the Strait south towards Seattle. Peak gusts for the majority of the area look to remain in the 20-30 mph range, though areas along the Strait and near Whidbey Island/Port Townsend, as well as Point Roberts have around a 50-70% chance to see gusts greater than 45 mph. Winds will slowly ease Friday evening and overnight.

Lingering chances for light showers continue into Saturday as a weak wave moves through the area. Shower chances diminish Saturday night.

Highs will be much cooler on Friday, in the upper 50s on the coast with low to mid 60s in the interior. Lows remain in the low 50s. Even cooler air will filter in on Saturday, with highs in the mid 50s to near 60s, with lows in the mid 30s to mid 40s. Will have to monitor for the amount of clearing and fog potential to see how low temperatures can get, as the more sheltered locations are beginning to near frost thresholds, through the more likely evening will be Sunday night/Monday morning.

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LONG TERM /SUNDAY THROUGH THURSDAY/

Ensembles continue to highlight drier but cooler conditions through the first half of the week. With the cooler temperatures, the lows on Sunday morning will generally range anywhere from the upper 30s into the lower 40s. Colder air in the Cascade valleys may drop the lows down to around freezing, with latest probabilities showing a 30% chance of temperatures 32 degrees or less on Sunday morning in those aforementioned areas. This will be the first in the season for any freeze or frost concerns, especially for those who have sensitive vegetation. Heading into the first half of the week, the lows will get warmer, generally in the 40s, while the afternoon highs will stay in the upper 50s to low 60s.

Troughing looks to continue over the Pacific Northwest through the work week, with a chance of a system entering the area Tuesday into Wednesday for more unsettled conditions.

Mazurkiewicz

AVIATION

Northwesterly flow aloft becoming westerly this afternoon as an upper level trough continues to drop down into the area. Fog has cleared way this afternoon, with most terminals rebounding to VFR, the exception being HQM where stratus continues to hug the coastline and the terminal, seeing LIFR conditions. A frontal system will move through the area tonight into Friday morning, lowering ceilings across much of the area to MVFR/IFR. Light rain will start along the coast 10z-12z, with showers generally affecting terminals 12z-17z. Will likely see lowered conditions through the early part of the morning through the interior before ceilings lift to VFR late afternoon.

N/NW winds this evening 4 to 8 knots, turning southerly overnight. Winds will increase Friday morning, 8 to 12 knots, with periodic gusts up to 20 kts.

KSEA...VFR conditions this afternoon continuing into the evening. Light rail will enter the area early Friday morning, lowering ceilings down to MVFR generally around 09z-15z. NW winds 4 to 8 knots this evening will turn southerly overnight, increasing to 8 to 12 knots through the morning with gusts briefly up to 20 to 25 knots at times. Breezy winds will likely continue throughout the afternoon before gradually decreasing, along with VFR returning.

Mazurkiewicz

MARINE

A frontal system will traverse the area waters tonight into early Friday. Ahead of the system, a brief increase in onshore flow through the central/eastern Strait of Juan de Fuca will allow for winds to reach Small Craft thresholds. As the system moves through, winds begin to increase area-wide early Friday morning. Gales will be most likely through the northern portions of the coastal waters, as well as through the central/eastern Strait of Juan de Fuca where gusts could reach up to 40 kt. Elsewhere through the Strait of Juan de Fuca and coastal waters, as well as through the Strait of Georgia and Admiralty Inlet, Small Craft level winds are more likely. Winds peak Friday afternoon before slowly easing Friday night. Headlines for the interior waters should be able to drop by late Friday night, but winds look to persist into Saturday morning through the coastal waters.

North/northwesterly winds persist into Saturday as a weak low moves through the area. High pressure will attempt to nose into the area Monday before another low pressure system looks to traverse the area on Tuesday for another round of stronger winds and increased seas.

Seas 6 to 7 ft will increase to around 12-14 ft, potentially locally up to 15-16 ft over the northernmost coastal waters during the day Friday. Seas remain around 12-14 through early Saturday morning before easing through the rest of the day. Seas then become around 5-7 ft Sunday before rising once again as the next system arrives on Tuesday.

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SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Small Craft Advisory from 2 PM to 11 PM PDT Friday for Grays Harbor Bar.

Small Craft Advisory from 2 AM to 8 PM PDT Friday for West Entrance U.S. Waters Strait Of Juan De Fuca.

Small Craft Advisory until 3 AM PDT Friday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca.

Gale Warning from 3 AM to 11 PM PDT Friday for Central U.S. Waters Strait Of Juan De Fuca-Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-Coastal Waters From Cape Flattery To James Island Out 10 Nm-Coastal Waters From James Island To Point Grenville 10 To 60 Nm-Coastal Waters From James Island To Point Grenville Out 10 Nm- East Entrance U.S. Waters Strait Of Juan De Fuca.

Small Craft Advisory from 2 AM to 5 PM PDT Friday for Northern Inland Waters Including The San Juan Islands.

Small Craft Advisory from 8 AM to 8 PM PDT Friday for Admiralty Inlet.

Small Craft Advisory from 5 AM to 11 PM PDT Friday for Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm.