Three Atmospheric Rivers During the Next Week

Three atmospheric rivers will be impinging on the Pacific Northwest, and substantial precipitation will be falling.

To illustrate, below is a plot of integrated water vapor transport (the intensity of the horizontal movement of water vapor by winds) on Friday at 5 PM.  The arrows show the direction and intensity of the water vapor transport.

Lots of water vapor pushing into western WA and BC.    Water vapor that will turn to precipitation as it is forced to rise by our local mountains.

When you get into the blue colors,  you know the atmospheric river is a strong one!

Late Monday, another (but weaker) atmosphere will make landfall

And then a monster atmospheric river will make landfall on Wednesday, with heavier precipitation in Oregon and northern California.

You want to see how much precipitation will fall?  

You bet..and be prepared to be impressed.

After the first atmospheric river (Saturday at 5 PM shown below), the Washington and BC mountains (and their windward slopes) will have received two inches or more of liquid water.

This is just the start.   

After the third atmospheric river moves through (Thursday at 4 PM shown), the accumulated precipitation totals will be stunning, with some locations getting over 10 inches of accumulated liquid water.

There will be a massive fill of regional reservoirs, and I suspect the persistent talk of drought will fade.   Of course, no more regional wildfires.

But as in late-night TV commercials, there is MORE!   The latest long-range European Center forecast for November through January predicts much more precipitation than normal over the region.

Lots of Snow in the Mountains....and the Seattle Times Gets it Wrong Again

 First, we had strong winds, taking out the power to a quarter-million local residents.  And then snow.

The vigorous system that moved through on Sunday and a second disturbance behind spread substantial snow over the regional mountains above approximately 4000 ft., with 1-2 feet on the ground in many locations.

The image at 8 PM at the Paradise Visitor Center on Mount Rainier (about 5000 ft) was a snowy dream, with the moon illuminating a winter wonderland.

Want to see how much difference a year makes?

Below are maps of the regional snow water equivalent (the amount of water in the snowpack) for last year (left) and this year (right) for 11 PM on October 26.

Can you tell the difference? 😊

Virtually nothing last year.   Bountiful snowpack this year.

And by tomorrow at 5 PM, there will be even more (see additional totals below).

Not enough to think about downhill skiing, but a good start, and a welcome beginning to the winter snowpack after a low previous year.  

A very strong atmospheric river will approach the region on Friday-Sunday, but I will leave that to my blog.

Seattle Times Errors Again

As long as I am talking about atmospheric rivers, I can't help but note the major errors in recent Seattle Times stories on this topic.   Consider the atmospheric river graphics they provided a few days ago (below).

Not very good. 

 It starts by stating that atmospheric rivers are "flowing columns of condensed water vapor". 

Water vapor is not "condensed".  It is vapor... .a GAS.  Most of the water associated with atmospheric rivers is not condensed water (that is, clouds or precipitation), but water vapor.

Water vapor that is forced to condense into clouds and precipitation as it is forced to rise by local terrain. 

    

They claim that the water vapor is found one mile above the ocean.  This is simply false.

 The claim that atmospheric rivers "generate a series of storms" is wrong.   Atmospheric rivers are the result of larger-scale circulations and storms.   The Seattle Times confused the chicken and the egg.

This error-filled Seattle Times graphic is not an isolated example of poor research and writing. I could show you a dozen more.  Ok, how about one?

Below is their graphic about the convergence zone and rainshadow.  They have the air approaching the Olympics from the southwest (which is fine), but then they show cold air from the Fraser River Valley. Wrong, wrong, wrong. 

And then they make the same mistake about "condensed water vapor" coming off the Pacific and repeat the error of the water being about one mile off the ocean.   

The quality of the scientific "journalism" in the Seattle Times is now so poor that you really can't trust what you read in it.  Just a shame.

The Storm Has Arrived

 The promised storm has begun.  Tens of thousands of customers have already lost power, mainly in the southern Puget Sound region at this point...and more will surely follow.

The composite weather radar image is extraordinary (see image around 7:40 PM below).  The low center was then along the central Washington coast.  We can only see this because of the Langley Hill radar near Hoquium (thanks, as always, to Senator Cantwell for helping to make that radar a reality).

A few hours earlier, the low center was also evident in visible satellite imagery (below).

As of 7 PM, winds have exceeded 70 mph on the coast and at Crystal Mountain, with and over 50 mph over the south Sound area (see below).

With low pressure along the coast and higher pressure inland, strong easterly winds from the east descended the western slopes of the Cascades, contributing to power outages from Issaquah and Black Diamond to Enumclaw and out to the Sound.

This has resulted in massive power outages in these locations (see Puget Sound Energy outage map at 7:30 PM)

In Seattle, only about 850 customers have lost power.  

The numbers increase greatly in the hours ahead.  

The latest UW/Seattle Windwatch prediction of maximum winds in Seattle suggests that winds will peak around midnight, as the low center passes to the north (see prediction below).    This early in the season, with lots of leaves on the trees and untested new growth, one can expect substantial power loss with such winds.

Showtime in 2-3 hours for central Puget Sound.  Time to make sure all my devices are charged up.

Potential for Power Outages Saturday Night/Sunday Morning

Local power companies should organize their supplies and ensure they are fully staffed starting around 6 PM tomorrow (Saturday).

If you live in western Washington, I would charge up your phones and other devices.

A significant blow is coming from a Pacific cyclone making landfall on southern Vancouver Island.

The first strong wind of the season, particularly in October, is always a problem.   There has been substantial growth over the spring/summer that has yet to be tested by strong winds.

Many trees still have leaves, which catch the wind better than the leafless situation later in the winter.

The University of Washington modeling system (WRF) predicts a 986 hPa low-pressure system west of the Washington coast at 10 AM Saturday (see below).   On this chart, the lines of isobars (lines of constant sea-level pressure) and the wind speeds (gusts, knots) are indicated by color shading.  Big pressure changes and strong winds (gusts to 60 kt) are south and west of the low center.

Classic for an ocean cyclone.

As the low moves into southwestern British Columbia, an intense pressure variation (gradient) will move into western Washington (see forecast for 11 PM Saturday night), which will produce strong winds over the region.

The strongest winds so far this autumn.

How strong?  In Seattle, the best way to find out is by going to the City of Seattle Windwatch website (below), which uses multiple weather models to visualize the strong winds over Seattle (below).

Late Saturday and early Sunday, the forecast gusts exceed 40 mph.  My rule of thumb is that early in the season, power outages start with 30 mph gusts and are certain with 40 mph gusts.

Over western Washington, the winds will come in two steps.  

Step one, around 11 PM, will have strong southerly winds (blue colors) from Everett southward (shown below).  

The second act, a few hours later, will have strong westerly (from the west) winds surging eastward in the Strait of Juan de Fuca, hitting NW Washington

Strong southerly winds will also push northward in eastern Washington (wind gusts over the entire state at 2 AM Sunday are shown below)

Puget Sound Energy, Seattle City Light, and other utilities should be ready.

I don't want to hype this event. It is not the Columbus Day storm by any means, but it will have impacts.

Finally, as the low moves past us, air temperatures will cool, and substantial snow is expected in the Cascades.    Snowfall totals through 5 PM Sunday are shown below

The good news in all this is that wildfire season is over in Washington, and our water resources are rapidly growing again. Large amounts of precipitation are being forecast for the next ten days over our region.

Serious storms....midlatitude cyclones...are now predicted

 

Multiple Atmospheric Rivers and Substantial Precipitation

 During the next weeks, a series of potent plumes of moisture (water vapor), commonly known as  atmospheric rivers, will be arriving on the West Coast, and we in the Pacific Northwest will get a substantial taste of it.

Much of the arriving moisture will have traveled thousands of miles from Southeast Asia!

Let me show you forecasts of these atmospheric rivers.  Red colors indicate the most potent areas of water vapor.  At 6 PM tonight (Tuesday), there is an atmospheric river with a tail that extends thousands of miles to the west.

Here is a moisture channel view of the atmospheric river tonight.  You will notice the moisture plume heads northwestward into the Gulf of Alaska, where it circles around a large low-pressure center..  Another stream of moisture is apparent far to the west, starting near SE Asia.  

Thursday morning, another atmospheric river is extending into southwest BC

Next Monday, a potent, intense river will push into north/central California

And the following Friday, a strong river hits the northwest

Still there there on Sunday morning.

These atmospheric rivers will bring lots of precipitation to our region.  Below is the total through Sunday morning.   Our regional mountains get hit pretty hard.  Even more during the next week (not shown).

The latest seasonal forecats are for wetter than normal conditions over the Northwest this winter (see below).  Not surprising for a La Nina year.

A Double Convergence Zone and the Upcoming Election in Seattle

Western Washington is the land of mountain-forced atmospheric convergence.  Convergence that can produce localized heavy showers and even thunderstorms.    

As shown in the figure below, when the low-level airflow off the Pacific is from the northwest, air is forced around the Olympics and then converges over central Puget Sound.   This convergence pushes air upwards, producing clouds and showers (see below).

Another convergence zone frequently develops east of southern Vancouver Island as air moving down the Strait of Juan de Fuca converges with air pushing southward down the Strait of Georgia.

The radar image around 4 PM today clearly showed both features: 

Both convergence zones were very evident in the visible satellite imagery around the same time (see below).  One amazing aspect of these convergence lines is how far east they extend:  over and to the east of the Cascade crest!

Think about it....folks in Wenatchee or Ellensburg can have added clouds and showers due to the local effects of the Olympics!  Who would have thought?

The southern feature, the Puget Sound Convergence zone, even had some thunderstorms, which were picked up by satellite lightning sensors (see the infrared satellite image below, with lightning strokes).

To show you how far numerical weather prediction has come, the FORECAST radar image at 5 PM from a simulation from yesterday is shown below.  Both convergence zones are there!  Couldn't do this 20 years ago.

Finally, the convergence zones produced two areas of localized rainfall, as shown below (only amounts greater than a third of an inch are shown).   Heavy rain in the mountains with these features.

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The Seattle Election 

There is a stark choice between candidates for City Attorney and Mayor, with Ann Davidson and Bruce Harrell being far and away the best individuals for these positions.

City Attorney

Ann Davidson has done an extraordinary job as City Attorney.  I am a numbers person, and the numbers show that Ann Davidson's leadership has produced excellent results.  Ann entered office in 2022.    Filing times for Domestic Violence cases dropped almost immediately.

Retail theft charge rates rose substantially.  Very important for keeping local businesses alive.

And the number of prolific offenders dropped substantially.

Ann Davidson's opponent seems to think the race is about Trump.  It is not. It is about public safety in Seattle.

I don't agree with the Seattle Times on everying, but they are very correct about Ann Davidson:

Seattleites who want a competent leader who prioritizes public safety and understands the bounds of the office ought to reelect Davison.

Davison is a solid public servant with a strong track record. To ensure a better city, she deserves reelection.

Mayorial Race

The choice for mayor is similarly easy.  Bruce Harrel has deep experience with our city.  He grew up here, was on the City Council for over a decade,  and now has substantial experience in managing a large complex government.   He has made some mistakes, but appears to have learned from them.  

In contrast, Katie Wilson has never been elected to any office.  She has never managed a large enterprise of any kind.   Her major initiatives are to tax the rich and use the funds for "affordable housing."   Perhaps she hasn't noticed the massive amounts of apartments and house units that have been built during the past decade, or that adding massive numbers of very low-cost housing will attract large numbers of folks from outside the city.  She does not appear to understand that much of the homeless problem is driven by drug use and mental illness.  

Ms. Wilson also has very unsettling opinions about Jews and Israel, accusing Israel of genocide and calling for Seattle to divest from Israel.   Such genocide claims reflect a prejudice incompatible with the leadership of a diverse American City.