The Other "Hurricane" Has Just Hit Our Region!

There is a lot of coverage in the press about powerful Hurricane Helene hitting the southeast U.S. (see visible satellite image below yesterday afternoon).  The hurricane eye is quite apparent. 

But did you know that a massive storm, a Pacific "hurricane" hit the British Columbia coast at essentially the same time?  (see the satellite picture below from yesterday).  

When Hurricane Helene hit the southeast U.S., maximum wind gusts yesterday reached 99 mph in two locations.  Very dangerous

 

What do you the maximum winds along the British Columbia coast were yesterday as the Pacific storm approached?   Make sure you are sitting down right now.  95 and 96 mph along the northern Vancouver Island coast.  Wow.

Now shown above it the wind at Solander Island, right off the NW coast of Vanvouver Island, where it got to 105 mph.

To get more perspective regarding the similarity of the two storms, below is a pressure analysis of both (solid lines, called isobars, and the difference of pressure from normal, shading).   Look pretty comparable don't they?   

Only one is called a hurricane since that name is restricted to systems of tropical origin.

A satellite image of the two storms is shown below.   Helene was an unusually large hurricane, but the Pacific storm was even bigger.

Why such strong winds along the BC coast?  

Because as the powerful Gulf of Alaska low moved to the coast, it created a very strong pressure gradient (pressure difference over distance) over the northern BC coast, and strong pressure gradients create strong winds. (see a sea level pressure forecast for yesterday afternoon below)

Finally, to compare the winds of the two storms directly, below is the estimate by the European Center for the probability of wind gusts exceeding 34 knot (about 40 mph) yesterday around 11 PD PDT.  The Pacific storm has such gusts over a larger area!

It goes without saying that Helene was a much bigger threat, hitting a highly populated region.    Fortunately, the forecasts for Helene were excellent, which hopefully reduced the loss of life.

In BC, there were large power outages and substantial damage (see below)

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Announcement:  Free Public Lecture at Kane Hall on October 10:  Global Warming, the Jet Stream, and Cold Waves

All of you are invited to attend what should be an excellent public lecture by Professor Jonathan Martin on how global warming affects the jet stream and cold air outbreaks.

It will be a timely and interesting lecture accessible to non-meteorologists and given in honor of UW Professor Peter Hobbs.

The talk will be at 7 PM in Kane Hall room 210.

If you would like to go, please register online here:

Parking is available (at a modest cost) in the UW Central Garage, which is located directly under Kane Hall.  Or take the light rail (the UW stops are a 5-10-minute walk away).