The Thunderbird Returns to the Northwest: Substantial Precipitation Ahead

 There are many Native American stories about the origin of Northwest storms and rain, with my favorite being about the Thunderbird, a huge avian living in a cave of the Olympics.  When it left its high abode to hunt for its favorite prey (the Killer Whale), storms, wind, and even lightning would occur.

If there was ever a month for Thunderbird flights, it would have to be November.

A tenth of an inch represents a decent wetting, and the frequency of that amount at Seattle Tacoma Airport is shown below.  There is a clear peak:  in mid-November!   By December, there is already a bit of drying!

With this climatology in mind, let's look at the latest forecast for accumulating precipitation.

With a weather system coming in tonight and tomorrow, the total through Thursday morning is substantial, particularly on the Olympics and the coastal mountains.  

By Friday morning, the Cascades will get to enjoy the wet fun with 2-3 inches of rain.  Note the profound rain shadow over the San Juans in the lee of the Olympics.

The next week will bring much more rain, with the totals through Friday morning, 14 November, getting to 4-5 inches in the mountains.

And far more, by Tuesday, Nov. 18th.   The Thunderbird will be busy.  This is enough to result in localized river flooding and substantial progress in filling local reservoirs.

An interesting aspect of the next two weeks will be the absence of major landfalling storms, with persistent low pressure staying offshore.

To illustrate, below is the sea level pressure forecast for tomorrow (Wednesday) morning.  Huge low offshore.

Five days from now, another low will be offshore. No major power outages to be expected, with this pattern.

No "bomb cyclone" action in our nearshore waters like last year.  At least not yet.

A relief for many.