DAMAGING WINDS LIKELY FOR PACIFIC NORTHWEST

After Thursday’s deadly wind event across the region, winter continues to create a late-season comeback in terms of the active pattern for the Pacific Northwest.

The National Weather Service has prudently issued High Wind warnings for all of Puget Sound and for coastal sections of Washington State as of 7 PM local time Saturday.

 

Above, there’s a spattering of warnings draped across the region including the aforementioned high wind warning for most coastal sections of the region.

The Warning Details

* TIMING...FROM MID SUNDAY AFTERNOON THROUGH SUNDAY EVENING.

* WINDS...SOUTH WINDS WILL RISE SUNDAY AFTERNOON WITH THE

  STRONGEST WINDS...20 TO 40 MPH WITH GUSTS TO 70 MPH...EXPECTED

  LATE SUNDAY AFTERNOON AND EVENING. WINDS WILL SHIFT TO WEST TO

  SOUTHWEST EARLY SUNDAY EVENING. WINDS WILL GRADUALLY DIMINISH

  THROUGH LATE SUNDAY 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.

 

For us, what’s the implication of some of those gusts crossing into Canada?

70 miles per is the equivalent of over 110 km/h...

You’ll often hear meteorologists on air discuss ‘track-dependency’ and how those details are ironed out closer to the weather event. But the weather event is tomorrow?

Yeah, but this is still in flux and the subtle nuances and exact track is still yet to be determined and will not be able to predict with perfect precision.

Where’s our low now?

Let’s turn to space.

The wave of low pressure is just east of the 140 W line. Over the next 24 hours the innocuous low pressure wave will rapidly deepen in atmospheric pressure as it curls towards the tip of Washington State.

With the track of the low forecast to cross so close to the Lower Mainland wind will come in several directions depending on what quadrant of the low pressure you find yourself in.

I think it’ll go something like this, but check-in tomorrow as this could change:

SE winds of varying intensity for the morning hours can be expected, and it’ll especially gusty near Victoria and the Gulf Islands and portions of East Vancouver Island (40-70 km/h).

By mid-afternoon the low reaches peak intensity SW of Victoria.

Now, crossing the NW tip of Washington State, SE winds will increase in intensity to warning criteria for the Gulf Islands and the Victoria area. At this point, sustained winds may approach 40 knots (70 km/h) especially by the water. Expect outages to occur at this point. Easterly winds are occurring across the lower mainland but not damaging (30-50 km/h).

Western Sections of the Lower Mainland have dealt with SE winds between 40-60 km/h and it’s been particularly gusty for Tsawwassen and UBC throughout the day.

Canadian Model Simulation: SE Wind Portion

Courtesy: WeatherBell

Courtesy: WeatherBell

Now, here’s where things get a little chaotic and complicated.

With the abrupt passage of the strong area of low pressure (980-985mb), winds will barrel down the Juan De Fuca strait out of the WSW at storm force (>50 knots) intensity early in the evening. Victoria is mildly protected, but southern sections of the Capital Regional District including Sooke, Metchosin, Colwood, Esquimalt, and Oak Bay are at the highest risk of outages.

Courtesy: WeatherBell

Courtesy: WeatherBell

As the low pressure system crosses the Lower Mainland winds will be swirling and damaging southerly winds are possible in the right quadrant of the low as it tracks inland (see above). Unfortunately, this would put the Fraser Valley under fire for a portion of the evening.

Isolated power outages are also possible further inland into parts of the Interior as the low crosses the southern portion of the province pre-dawn Monday.

The westerly surge will be abrupt and sudden for Vancouver in the evening; watch for tree damage around Stanley Park, UBC, and Delta & even parts of the North Shore as we head later into the evening.

SW Winds will ease overnight, but at this point thousands of power outages have likely occurred.

The ground is relatively saturated with the recent rains. Tidal surge is not anticipated to be as significant as last Thursday’s system.

Stay safe and send updates to #BCstorm and @weathernetwor