textproduct: Seattle/Tacoma

SYNOPSIS

An upper level trough will weaken today with high pressure aloft will rebuilding across the region Monday into Tuesday for warm and drier conditions. Another weak trough offshore will temporarily cool temperatures midweek before a longer term warming trend begins toward next weekend with a strong ridge of high pressure.

SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/

The latest forecast remains on track this evening with no updates. An upper level ridge will nudge slightly into the area Monday into Tuesday, promoting warmer temperatures back into the upper 70s and low 80s for most of the area Monday and Tuesday, with Tuesday likely being the warmer day of the two. Areas of Seattle Metro and southward will likely see Moderate (Orange) HeatRisk on Tuesday - with all other places across western Washington seeing Minor (Yellow) HeatRisk.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Upper level heights will stay relatively high on Wednesday, with latest ensembles keying into a upper level low offshore. Guidance is struggling on the exact path and strength of this cut off upper level low as of now. We will continue to monitor on how this cut off low develops because it may introduce some convection in our area, especially in the Cascades. For the remainder of the week, it looks like strong upper level ridging will develop which will warm temperatures up above normal - heading into the weekend.

Mazurkiewicz

AVIATION

VFR across the terminals this evening with most sites remaining VFR through the period under mostly clear skies. However, marine stratus is slated to develop along the coast (KHQM) around 10-12z Monday along with isolated coverage over the interior. Stratus is favored to burn off by 16-18z allowing the return of VFR. Light to moderate low- level onshore flow developing this evening and overnight with north- northwest surface winds increasing in the afternoon to around 5-12 kt with gusts to around 20 kt for Puget Sound terminals.

KSEA...VFR throughout the period under mostly clear skies. North to northeast winds will prevail tonight, decreasing to around 5 kt overnight. Northerly winds will continue through the TAF period, increasing to around 7 to 12 kt Monday afternoon.

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MARINE

Surface high pressure over area waters throughout the next few days. Diurnal westerly winds through the Strait of Juan de Fuca will be the main theme with the next best chance of headlines on Tuesday evening. Winds during this time appear to be SCA-level but gusts could get to near gale strength. Coastal waters may also see wind gusts approach 20 kt towards the end of the week on Thursday and Friday with another low system tracking through the waters.

Seas for the majority of the forecast will remain at 4-6 ft, with the system Thursday/Friday increasing seas to 7-8 ft with periods around 6-8 seconds.

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FIRE WEATHER

The lack of offshore flow through the middle of the week will keep fire weather concerns at a minimum. Warming temperatures later in the week will begin to increase the fire weather risks going into the weekend. An upper trough arriving around midweek will need to be monitored in the days ahead for potential convection and associated risks of lightning strikes with fuels now running quite dry.

SEW WATCHES/WARNINGS/ADVISORIES

WA...None. PZ...None.