textproduct: Seattle/Tacoma

SYNOPSIS

Dry and warm conditions continue today across Western Washington, with even warmer temperatures Friday. The next disturbance shifts over the area late Friday through Saturday, bringing cooler and cloudy conditions along with showers and isolated thunderstorms. High pressure returns early next week, bringing back dry and warmer conditions.

SHORT TERM /TODAY THROUGH SATURDAY/

Dry and steadily warmer temperatures will continue across western Washington through the next several days as low pressure remains off the B.C. coast and gradually rising heights across the region. Modest onshore flow continues in the lower levels of the atmosphere each of these days, maintaining some degree of clouds each morning that give way to mostly sunny skies in the afternoon. Temperatures through the interior climb through into the 70s today, with cool nights limiting the HeatRisk to minor levels. Even with the warmest day of the week on Friday, as temperatures reach the lower 80s, will maintain only a minor risk of heat-releated illness.

Ensemble guidance continues to favor a shift in the pattern late Friday into Saturday across the region, as the next upper low shifts inland. This will usher the arrival of a more solid cloud deck, cooler temperatures, and even some rainfall chances. These rain chances will be highest along the coast and in the Olympics, but a potential Puget Sound Convergence Zone behind the system will also be another focus for shower chances. Gusty southerly wind gusts also develop across much of the lowlands, with gusts to 20-25 mph expected. There's also around a 15-20% chance for an isolated thunderstorm or two, especially closer to the North Cascades

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/

Any lingering showers likely come to end Sunday as the upper low departs the region and heights again begin to rise. High pressure builds across the interior during the early portions of next week with steadily warmer temperatures. Expect highs in the interior to again reach the 80s with a few spots approaching 90 Tuesday. This will largely maintain Minor HeatRisk for the early part of next week, though chances increase to around 40-50% Tuesday and Wednesday for some areas of Moderate HeatRisk for the Seattle area south through Lewis County.

AVIATION

Southwesterly flow aloft with weak low level onshore flow into Friday. Areas of MVFR ceilings west of Puget Sound until 18z otherwise mostly clear skies.

KSEA...Mostly clear skies through Friday morning. Variable wind 5 knots or less becoming southwest 4 to 8 knots around 15z, west southwest 4 to 8 knots around 22z and northerly 4 to 8 knots after 04z. Felton

MARINE

High pressure over the waters through Friday. Another weak system will reach the waters Friday night and Saturday. High pressure will rebuild over the coastal waters Sunday and remain in place through Monday.

Gale force winds are likely in the Central and Eastern Strait of Juan de Fuca late Saturday afternoon into Saturday evening.

Seas mostly in the 3 to 5 foot range over the inner coastal waters and 4 to 6 feet over the outer coastal waters into the first part of next week. Felton

FIRE WEATHER

Next elevated fire weather conditions Friday with warmer and drier weather with minimum relative humidity values approaching 30 percent in the Black Hills and SW Interior lowlands, SE Puget Sound lowlands, and Cascade valleys. A system Saturday will ease fire weather concerns with wetting rains north coast and North Cascades. Slight chance, less than 15 percent, of thunderstorms in the North Cascades near the Canadian border. Another round of elevated fire weather concerns beginning Monday and continuing through the week with above normal temperatures and low late day minimum relative humidities. Felton

SEW WATCHES/WARNINGS/ADVISORIES

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