textproduct: Seattle/Tacoma

UPDATE

Satellite imagery shows most of the fog from about Seattle south to Chehalis and in the Snohomish River Valley. Tops of the fog less than 1000 feet. Expect the fog to dissipate by noon over the Central Puget Sound with the fog hanging on into the afternoon hours from Olympia to Chehalis. Tuesday and Wednesday morning look similar with a little more fog coverage as the low level flow becomes lighter. No update to the forecasts this morning. Felton

SYNOPSIS

A stable and strong upper level ridge will keep conditions dry through mid week. A weak system may bring light precipitation by the end of the week and into the weekend.

SHORT TERM /TODAY THROUGH WEDNESDAY/

A strong upper level ridge will continue to keep conditions benign and dry across western Washington. Areas of fog this morning across the area, especially near the water. High temperatures this afternoon will generally be in the upper 40s with some locations in the low to even mid 50s.

Upper level ridging continues through Wednesday, with fog coverage each morning - burning off by the afternoon except in the Southwest Interior where the fog will last into the afternoon hours. Temperatures will slightly cool Tuesday and Wednesday, in the mid to upper 40s for much of the area. Overnight lows trend in the low 30s to mid 30s..with areas along the water and especially South Sound seeing temps below freezing.

LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/

Confidence is still low on the long term but latest ensemble guidances shows a weak system on Thursday becoming more dry as it brushes over the area. Ensemble guidance is also showing more drier solutions over the weekend, with another upper level ridge building offshore. Confidence remains low considering it is rather far out but it looks like we could remain dry into the weekend. For now have included a chance of PoPs in the forecast.

Mazurkiewicz

AVIATION

High pressure will remain over the region with north flow aloft. Fog continues to expand across the interior this morning. Conditions across the terminals are primarily VFR for terminals outside of fog and IFR to LIFR for terminals in fog (or freezing fog with some of the colder terminals). Fog will lift late morning/early afternoon hours for a return to more widespread VFR conditions. Light and variable winds under 5 kt this morning will become north 3-7 kts late this morning/afternoon and out of the east/northeast for terminals more susceptible to offshore flow, like KHQM and KCLM. Another round of fog will be possible on Tuesday morning (40-60%).

KSEA...Fog has moved into the terminal this morning, with 1/4 NM visibilities. Clearing time around 18Z is expected with VFR rest of the day. Light NE winds under 5 kt will increase to 3-7 kt late this morning/afternoon. There is a 40-60% chance of fog Tuesday morning, with winds expected to drop again below 5 kt tonight.

14/HPR

MARINE

High pressure will persist over the coastal waters through the first half of the week, with a thermal trough situated along the coast. This will continue to promote offshore flow through at least Wednesday. A weak frontal system may approach the waters on Thursday, allowing for flow to briefly turn back to onshore. This will remain short-lived, however as high pressure will build back into the region by Friday, bringing another round of offshore flow.

Seas will hover between 4-6 ft through much of the week. Fog will be possible across the interior waters this morning and again on Tuesday morning and may bring visibilities down to 1 nautical mile or less at times. A dense fog advisory is in effect for the Puget Sound waters through 11 am due to dense fog in the area.

14/HPR

HYDROLOGY

No river flooding next 7 days.

SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...Dense Fog Advisory until 11 AM PST this morning for Puget Sound and Hood Canal.