December 11, 2024

A Major Cyclone Will Approach Our Coast But Not a Repeat of November 19

A very strong, rapidly developing, midlatitude cyclone will approach the Northwest coast on Friday and move through on Saturday.

Fortunately, the wind situation will be far less threatening in the interior compared to the November 9 event.  This blog will explain why.  But big waves may cause problems on the northwest coast.

Let's start with the predicted sea level pressure and surface wind gust map at 10 AM Friday morning.  

Pretty scary looking, with a 979 hPa low-pressure center.  Strong winds (up to 60 knots) will occur in a ring around the low center.  An associated occluded front will be hitting the Oregon coast with even stronger winds at this time.

By 7 PM on Friday the low will move northwestward and strengthen slightly to 977 hPa. 


Overnight the system will weaken and move across northern Vancouver Island.

Importantly, this will change the orientation of the isobars, producing a large north-south pressure difference and strong winds over NW Washington,

Over western Washington, the winds will evolve in three acts.

In the first, shown at 1 PM on Friday, strong winds (blue colors) will occur along the coast and over the waters of NW Washington.  Strong downslope winds will occur on the lee (NE) side of the Olympics. Moderate (20-35 kt) easterly winds will descend the western slopes of the Cascades, but their strength will be NOTHING like November 19th.


In stage two,  shown at 1 AM Saturday, the coastal winds will weaken, although still strong on the northern WA coast.  The downslope easterly winds will have ended and winds will pick up over Puget Sound.

In stage three, northern Puget Sound winds (from roughly Seattle to Bellingham) will strengthen with gusts reaching 30-40 knots from the Sound.   A few branches may fall and I expect a few minor power outages.  Nothing significant.  Winds will fade later in the day


This event will represent a typical mid-winter blow.

The most serious impacts may be the waves and high water levels on the Washington Coast.

The strong winds acting on the Pacific should produce substantial wave action on our coast and Vancouver Island.  The latest NOAA WaveWatch3 prediction is for significant wave heights of 20-30 ft.

That will be on top of some higher-than-normal astronomical tides (see below for La Push/Quilayute):

Clearly, some potential for coastal flooding on the northern Washington coast late Friday and Saturday.


December 08, 2024

Poor Vegetation Management and Windstorm Power Outages: A Frustrated Meteorologist Complains

 One of the great frustrations of being a meteorologist is to see a major event nearly perfectly forecast, yet with massive impacts on society.

It is frustrating to be concerned about global warming and seeing our region unable to keep the lights on for over a million people, some for 2-5 days. Without reliability, a transition away from fossil fuels cannot be made.

I have blogged several times about the major easterly wind event on November 19, which resulted in over a half-million homes losing power.    This event was nearly perfectly forecast several days ahead.....so there is not much more my discipline can do.


Brave, resilient individuals who restored power, some working for 12-36 h without rest, are the heroes of this story.

The villains?   Perhaps utility companies that were complacent about clearing trees and branches from the powerlines.  Utilities that did not invest in underground wiring when needed.

Let me show you some examples...and you be the judge.

Large areas in Seattle were out of power for 3-5 days, resulting in spoiled food, folks forced out of their homes by cold, and closed businesses.

For example, major Seattle City Light powerlines in northwest Seattle along Sand Point Way NE  (between NE 70th and NE 95th) frequently fail because of the lack of trimming of branches that extend above the powerlines.   Multiple branch failures on these lines blacked out northern Magnuson Park, Inverness, Inverness Park, Sand Point Country Club, and Mathews Beach on November 19, affecting thousands of Seattle residents.

Even today, there are large sections of Sand Point Way NE where branches extend over the powerlines (see below)....the next power outage is ready to go!



Vegetation management outside of Seattle, mainly in areas for which Puget Sound Energy is responsible, is even worse.   A few of thousands of examples are shown below

South of Issaquah

Mercer Island....find the powerline!

If this region is really serious about moving to a dependency on electricity, the power grid needs to be much more reliable.   Either bury power cables or initiate a massive program of tree trimming and removal.  Meteorologists are doing our part... utilities must do theirs.




A Major Cyclone Will Approach Our Coast But Not a Repeat of November 19

A very strong, rapidly developing, midlatitude cyclone will approach the Northwest coast on Friday and move through on Saturday. Fortunately...