Update 7:00pm
The power that was lost due to high winds that blew through the Seattle area on March 13 finally began to diminish as the evening wore on and people who lost power mostly had it restored. Trees came down all over the area and thousands lost electricity, but City Light crews managed to get it mostly restored before their estimated times.

Update 11:45am Sunday

National Weather Service updated this morning said the winds will arrive sooner but be somewhat lower than an earlier forecast. They had predicted gusts up to 70mph but have downgraded to 60mph, still a strong wind event.

...HIGH WIND WARNING NOW IN EFFECT UNTIL 8 PM PDT THIS EVENING...

* TIMING...THE STORM IS MOVING FASTER AND WINDS ARE EXPECTED TO BEGIN RISING SOONER...AROUND MID MORNING. THE STRONGEST WINDS ARE NOW EXPECTED DURING THE LATE MORNING THROUGH EARLY AFTERNOON.

* WINDS...EAST TO SOUTHEAST WINDS 20 TO 30 MPH...SHIFTING TO SOUTHWEST 25 TO 40 MPH WITH GUSTS TO 60 MPH IN THE LATE MORNING AND EARLY AFTERNOON. WINDS BECOMING WEST 20 TO 30 MPH WITH GUSTS TO 40 MPH THIS EVENING.

* IMPACTS...POWER OUTAGES AND DOWNED TREES ARE LIKELY. SOME DAMAGE TO BUILDINGS IS POSSIBLE. REMEMBER THAT FALLING TREES AND TREE LIMBS CAN CAUSE SERIOUS INJURY OR DEATH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH WIND WARNING MEANS A HAZARDOUS HIGH WIND EVENT IS EXPECTED OR OCCURRING. SUSTAINED WIND SPEEDS OF AT LEAST 40 MPH OR GUSTS OF 58 MPH OR MORE CAN LEAD TO PROPERTY DAMAGE.

Update 6:45 Saturday
The high winds predicted for Sunday just got a bump up in speed with the top gusts now at 70mph. That means move anything that's on patios, decks or outside to a secure area, be aware of any "wind sail" tree limbs, and make sure you have batteries and flashlights since power outages are highly likely.
The most recent forecast says:

* TIMING...SUNDAY AFTERNOON THROUGH SUNDAY EVENING. STRONGEST WINDS WILL LIKELY BE LATER SUNDAY AFTERNOON THROUGH EARLY EVENING.

* WINDS...SOUTHEAST WINDS 20 TO 30 MPH WITH GUSTS TO 45 MPH POSSIBLE EARLY IN THE AFTERNOON. WINDS WILL SHIFT TO SOUTH TO SOUTHWEST AND RISE...WITH STRONGEST WINDS REACHING 30 TO 45 MPH WITH GUSTS TO AROUND 70 MPH IN THE LATE AFTERNOON AND EARLY EVENING. WINDS WILL GRADUALLY DIMINISH THROUGH LATE EVENING.

* IMPACTS...WIDESPREAD POWER OUTAGES AND DOWNED TREES ARE LIKELY. SOME DAMAGE TO BUILDINGS IS POSSIBLE. REMEMBER THAT FALLING TREES AND TREE LIMBS CAN CAUSE SERIOUS INJURY OR DEATH.

Original post
The National Weather Service is forecasting high winds on Sunday afternoon into evening predicting sustained winds of between 20 to 40 mph with gusts to 60mph possible. That could mean power outages and downed trees.

Here's their forecast:

3:28 PM PST FRI MAR 11 2016

...HIGH WIND WATCH IN EFFECT FROM SUNDAY AFTERNOON THROUGH LATE
SUNDAY NIGHT...

THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A HIGH WIND
WATCH...WHICH IS IN EFFECT FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY NIGHT.
* TIMING...SUNDAY AFTERNOON THROUGH SUNDAY NIGHT. STRONGEST WINDS
WILL LIKELY BE LATER SUNDAY AFTERNOON AND EVENING.

* WINDS...SOUTH TO SOUTHWEST WINDS 20 TO 40 MPH WITH GUSTS TO AROUND 60 MPH ARE POSSIBLE.

* IMPACTS...POWER OUTAGES...DOWNED TREE LIMBS AND TREES ARE POSSIBLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HIGH WIND WATCH MEANS THERE IS THE POTENTIAL FOR A HAZARDOUS HIGHWIND EVENT. SUSTAINED WINDS OF AT LEAST 40 MPH...OR GUSTS OF 58 MPH OR STRONGER MAY OCCUR.

CONTINUE TO MONITOR THE LATEST FORECASTS.