March 30, 2024

Northwest Wind Energy Generation Collapses Again: Can We Blame El Nino?

 The latest Northwest energy generation statistics are available from the Bonneville Power Administration and they are sobering:   wind energy generation (green line) has collapsed over the past several days (see below).   Spring is normally a time when wind generation increases robustly, but not this year.


What is going on?

Something happened between March 25th and March 27th.  But what?

Winds are driven by pressure differences, so let's examine the changes in the regional pressure fields.

At 5 PM on March 25th, there was high pressure offshore and low pressure over eastern Washington, resulting in westerly (from he west) flow descending into eastern Washington (see pressure map below).  Good for wind energy generation.


A look at the winds at 5 PM on March 25th (below, with gusts in red), shows substantial winds (greater than 20 knots) over many of the prime wind-generation areas of eastern Washington and Oregon.


But the pressure situation on the 27th at 5 PM is radically different, with a strong low offshore (see below).


This greatly weakens the pressure difference across the Cascades and thus the winds.  To see this explicitly, here are the regional winds at 5 PM on the 27th.  Can you see the difference?


A plot of the sustained windspeed and gusts at Ellensburg Airport further illustrates the situation (below)


We have repeatedly been in a situation with a low-pressure area offshore this winter.   As noted in my previous blogs, this is a classic situation during El Nino years, something shown by a composite analysis of pressure differences from normal during El Nino years (see below, from a NOAA website).   The blue colors indicate enhanced low pressure offshore.

For those hoping for wind energy to lead the way to independence from other energy sources, this situation is a warning.  Wind energy alone can not fill the gap: it is too variable, both by season and by weather regime.  

This situation is particularly concerning considering the rapid rise in electricity usage, driven by increasing numbers of electric cars, massive new computational centers, and the push by many governmental groups and others to reduce the use of natural gas for heating and cooking.

The problems with wind generation make the consideration of nuclear energy critical for any serious reduction in fossil fuel use.

March 28, 2024

First Look at the Weather for the April 8 Solar Eclipse

 I have gotten a lot of inquiries about the weather on April 8, the day of the total solar eclipse of the sun over the eastern half of the U.S.

Our operational forecast models reach that far in time and have for a few days.  But considering the uncertainty at such a long projection, I have refrained from commenting until now.

The model solutions are starting to settle down and I have increasing confidence that I can provide useful information.  So let me do the first of several updates on the weather associated with the event.

The area of totality will extend from Texas to Ohio to northern Maine (see below).


Totality will occur at roughly 1800 UTC (11 AM PDT) for most of the path (earlier to the southwest, later to the northeast).   Here in Seattle, only about 20% of the sun will be covered (see below).  You would hardly notice this, even if the skies were clear.


The Forecast Situation

Below is the forecast 700-300 hPa (10,000-30,000 ft) relative humidity, a good measure of cloud cover, at 1800 UTC 8 April based on the U.S. GFS model.

Portions of southwest Texas might have a good view, but I worry about viewing conditions over much of the Midwest.  Some openings in Ohio and northern Maine.


But at this projection (270 hours), there is still substantial uncertainty.   Only when we get within roughly 5 days (120 hr) will confidence be relatively high in the forecast.

To illustrate the uncertainty, let me show you are series of forecasts for the above humidity field for four different forecast projections, but verifying at the same time (1800 UTC 8 April).  Specifically, you are viewing an animation of 288, 282, 276, and 270-hour forecasts of sea level pressure (solid lines) and the moisture field.  

All have some kind of low-pressure system and a plume of clouds in the middle part of the country and it appears the solutions are converging.  But there are significant changes between the forecasts.  

For Seattle, the variations are quite large.


An animation of the precipitation forecasts valid for the same eclipse time is shown below.   Enough precipitation to get a Midwest eclipse watcher nervous. And not promising for western Washington.


Another approach for such a long-term forecast is to look at the forecasts of ensembles of many forecasts.  

Below is the North American Ensemble Forecast System (NAEFS) prediction of clouds over Dallas/Fort Worth Texas over time.  I put a red arrow at the time of the eclipse.  Remember:  an ensemble forecast shows the results of many different forecasts all valid at a certain time.

10 indicates total cloud cover.  The horizontal line shows the median cloud cover for that location and the yellow box around the medium shows the range of 50% of the ensemble forecast members. (remember that the median is in the middle of a distribution of many forecasts, as many above as below).

 Lots of clouds and lots of uncertainty at that location.


Anyway, if you are planning to go to the eclipse, don't expect perfect conditions and be prepared to move, depending on the closer-in forecasts. 



March 26, 2024

The Seattle Times Says Washington State is in a Serious Drought. Is this True?

It is more than a little disturbing when a major regional newspaper (the Seattle Times) provides demonstrably inaccurate and deceptive weather and climate information.

But yesterday, the infamous Seattle Times ClimateLab did it again.


The first lines of the article describe the past year in apocalyptic terms:

Virtually every aspect of life in Washington suffered during last year’s drought. 
Groundwater wells ran dry, fields produced fewer crops, trees died in greater numbers, fish faced disease and famine

And the next paragraph paints a very dark picture of our future:

Now those sectors are bracing for yet another poor water year as El Nino conditions, compounded by climate change, produced well below normal snowpack. The state also has recently hit record-high temperatures for this time of year.

The state’s water woes will continue, even worsen, in the decades ahead.

Has the state been in a terrible drought that has seriously impacted agriculture, causing fish to face famine, and causing regional water shortages?  And are other claims of this article true, such as high temperatures causing terrible losses in the State's cherry crops?

Most of the claims are factually wrong.

The article was accompanied by a picture of a Rattlesnake Lake, which looked like a scene from the moon.   They did not mention that this is an artificial lake controlled by Seattle Public Utilities.


So are we in some terrible drought that caused state agriculture to fail?

Absolutely not.  The 2023 state apple crop was huge under near-perfect conditions (28% above 2022).  Apples are the state's number one crop.

The number two WA crop is milk and 2023 tied the record-breaking amounts in 2022.

The number three WA crop is potatoes, which had a 9.5% increase over 2022.

Doesn't sound like agriculture took too much of a hit from the Seattle Times's drought.

But what about the cherry crop you ask?  The Seattle Times states:

sudden melt-off (of snow in May 2023) sent the state’s sweet cherry growers into an early harvest, causing perhaps $100 million in losses.


It turns out the truth was a bit different.  The Washington State cherry crop was very large and high quality.  The problem was the cool, wet weather resulted in a bumper, late crop in California that suppressed prices.  

So low that Washington cherry farmers left a lot of the crop on the trees. So it was the OPPOSITE of drought in California that caused problems for Washington State farmers.  Lots of snow and rain in the "Golden State"


The Seattle Times describes famine times for fish, but salmon returns were UP for all areas of Washington State.

So are we in a drought right now?

The accumulated precipitation at Seattle for the past year is nearly normal (green is this  year, brown is normal):

Portland was wetter than normal.

What about Yakima on the eastern Cascades slopes?  Near normal.


Doesn't look like much of a drought. Yes, the snowpack is less this year because temperatures were warmer than normal for a while (due to El Nino, NOT climate change).  

But the amount of water falling from the sky was near normal and many reservoirs stored more water than usual.

Seattle's reservoirs are above normal (see below)

And the same is true for Everett's large Spada Lake reservoir:


Surely, if the Seattle Times is correct, river levels would be at very low "drought" levels.

Maybe not.  The streams on the "dry" eastern slopes of the Cascades are running high (see below).  Nearly normal streamflow conditions on the western slopes of the Cascades.  The only streams running low are around the South Sound area.


In summary, Seattle Times ClimateLab articles are not doing anyone a favor by telling tall tales about drought and climate change.  El Nino conditions are evident right now, with low snowpack but near normal precipitation.   Agriculture is not collapsing.  Precipitation is near normal.  

Truth matters.  Or at least it should.







March 24, 2024

Potential Aurora Over Washington State Tonight

Look to the north tonight, you might see an aurora!

Skies are relatively clear outside, as shown by the visible satellite image around 6 PM

A significant solar CME event has resulted in particles reaching the Earth's orbit today.  As shown by a NOAA Space Weather Center graphic, the Kp index has reached 8 and will be quite high tonight. 

The figure below illustrates that auroral intensity and southward extent increase with Kp.  Once it gets to around 5, I start looking here in Puget Sound!


In fact, tracking the ejection from the sun shows that the impulse will reach our orbit tonight, just after dark.


Here is the predicted auroral extent this evening.  I am encouraged.

If you can't go out, the next best thing is to check the sensitive sky cam at Skunk Bay Weather that is found here: https://www.skunkbayweather.com/SkunkBayWebcam.html





March 22, 2024

Space Weather: March is Aurora Season, Particularly This Year

We should not forget that the Earth's atmosphere can be seriously influenced by the "weather" on the sun!

Auuoral displays are particularly frequent in March for reasons I will explain later.

The sun's surface is not uniform over time, with varying sunspots and "solar storms", including solar flares and coronal mass ejections (CME), that send solar particles away from the sun and can greatly disturb the sun's magnetic fields.  

Such solar disturbances can be associated with higher-latitude auroras and the disruption of  radio communication and electricity transmission.

CMEs and other solar disturbances are modulated by the number of sunspots on the sun's surface, with more sunspots resulting in more activity.

Sunspots vary over time, with an eleven-year cycle being the most prominent (see below)


Importantly, we are now approaching the peak of a cycle (see a blow-up image below).  So there is an increased probability of solar "action" during this period.


But there is more.    

The potential for auroras and other solar impacts on Earth is maximized in our current season.  As shown in the next figure, the number of days in which solar disturbances impact the earth; 's atmosphere peaks in early spring and early fall, near the time of the equinoxes (night and day being similar lengths)

Why is that?     

It has to do with the orientation of the earth's axis relative to the sun.   During the equinox, the poles are oriented perpendicular to the sun's rays and the magnetic fields of the sun and earth are aligned in an optimal way to produce auroras (I will not go into the details here).


As an aside, you can see the nearly simultaneous sunrise north to south from the visible satellite image this morning (below).   The terminator separating day from night is a vertical line from the north to south poles.


So should you expect any auroral activity soon?   The NOAA Space Weather Center has declared a MINOR geomagnetic storm alert after some minor solar flares a few days ago.  Nothing serious, but it should rev up auoral activity in northern latitudes.   Nothing serious.


But be ready for more interesting solar storms.    The geophysical dice are weighted in their favor this year and season.


March 19, 2024

Summertime Low Clouds in Winter!

The satellite picture this morning did not look like mid-March.   Really reminded me of June or early summer.

A massive area of low clouds (mainly stratus and fog) covered the northeast Pacific, with some of the clouds pushing into western Oregon and Washington.


A view from a webcam at LaPush on the northern WA coast this moring was pretty dismal.


Viewing a local, high-resolution visible satellite image at 8:06 AM this morning shows the low clouds offshore, pushing into the Chehalis Valley and eastward down the Columbia.  Look closely and you will see some fog in the Snoqualmie drainage and around Bellingham.

Look even more closely and you will see the thin, tell-tale streaks of contrails, many going north-south and some oriented east-west.    There are some wide super-contrails (oriented east-west) along the coast, with their shadows on the low cloud below.

So why this summer-like low-cloud pattern?

Because summer-like high pressure has built offshore over the eastern Pacific (see surface pressure map for 10 PM Monday evening).  

A high-pressure area offshore results in northerly winds along our coast (typical of summer) and a low-level stable layer or inversion (temperature increasing with height), which is ideal for promoting low clouds.

High pressure is associated with sinking air aloft, particularly on the western sides of high-pressure areas.   Sinking air warms by compression (like in your bicycle pump, which is warm to the touch after you fill your tires).   Clearly, sinking is weaker near the surface (air can't move through the ground).  With greater sinking and warming aloft, an inversion often forms at low levels when high pressure is nearby.

Inversions are very stable structures, suppressing vertical motion, which is good for low clouds and fog.  They can also foster haze and air pollution.

Want to see the influence of the current high pressure on low-level temperatures? 

 Below is the lower part of the vertical sounding at Forks on the Washington coast, with the data coming from the radiosonde launched twice a day at that location.  The red line is temperature and the blue dashed line is dewpoint.   

Mama Mia!   That is a very strong inversion, with temperature increasing from the surface (around 1010 hPa) to around 950 hPa (roughly 2000 ft ASL) by about 13C (roughly 23F!!). 

 Temperature and dewpoint are the same in a very shallow layer:  This is where the low clouds are found.


Enjoy this taste of summer.   Much cooler temperatures and precipitation will soon return.


March 18, 2024

Should I Let AI Write My Blogs?

I spend a lot of time thinking about and writing my blogs.  

Could AI apps do the work for me?   Could any of you tell the difference?


Well, let's give them a test! First I asked Google's Gemini to write a blog in my style on the subject of the Puget Sound Convergence Zone.  Here is its attempt:

_________________________

Exploring the Mysteries of the Puget Sound Convergence Zone

Welcome back, weather enthusiasts! Today, we delve into one of the most intriguing and mystifying phenomena that grace the skies of the Pacific Northwest: the Puget Sound Convergence Zone (PSCZ). Nestled in the heart of the Puget Sound region, this atmospheric feature often leaves residents scratching their heads in wonder and meteorologists pondering its intricacies.

What is the Puget Sound Convergence Zone?

Imagine a meteorological ballet, where air masses gracefully pirouette and swirl, creating a symphony of weather patterns. Such is the essence of the Puget Sound Convergence Zone. Picture a convergence of air masses, where maritime air from the Pacific Ocean collides with colder, denser air from the interior of the continent. This collision sets the stage for a spectacle of cloud formation, precipitation, and atmospheric dynamics.

The Dance of the Elements

As maritime air flows inland from the Pacific, it encounters the towering peaks of the Olympic and Cascade mountain ranges. Forced to rise, this moist air cools and condenses, giving birth to clouds and precipitation. Meanwhile, colder air masses from the east press against this maritime flow, creating a zone of convergence where the two air masses meet.

In this convergence zone, the air is forced to rise even further, intensifying cloud development and precipitation. The result? A narrow band of enhanced rainfall, stretching from the northern reaches of Puget Sound down to its southern shores. This band of precipitation can be quite localized, with areas just a few miles apart experiencing vastly different weather conditions.

The Influence of Topography

Ah, the intricacies of topography! Just as a conductor guides an orchestra, so too does the landscape orchestrate the movements of atmospheric elements. The Puget Sound Convergence Zone owes much of its existence to the unique geography of the region.

The presence of the Olympic and Cascade mountain ranges plays a crucial role in shaping the PSCZ. As air masses encounter these towering barriers, they are forced to ascend, setting the stage for convergence and atmospheric drama. Additionally, the complex network of valleys, fjords, and inlets further influences the behavior of the convergence zone, guiding its movements and intensifying its effects in certain areas.

Forecasting the Unpredictable

Ah, the eternal challenge of weather forecasting! While meteorologists have made great strides in understanding the Puget Sound Convergence Zone, predicting its exact behavior remains a daunting task. The narrow and transient nature of the convergence zone poses a challenge for forecasters, who must rely on a combination of observational data, computer models, and sheer intuition to anticipate its movements.

However, despite its unpredictable nature, the PSCZ has not eluded the watchful eye of science. Advances in weather modeling and observational technologies have provided new insights into the dynamics of this atmospheric phenomenon, helping forecasters better anticipate its impacts and provide timely warnings to residents.

Embracing the Mystique

In a region renowned for its diverse and dynamic weather, the Puget Sound Convergence Zone stands out as a testament to the intricate interplay of atmospheric forces. Its ever-shifting patterns and elusive nature serve as a reminder of the awe-inspiring complexity of the natural world.

So, the next time you find yourself caught in a sudden downpour or gazing up at a mesmerizing display of clouds, take a moment to appreciate the mysteries of the Puget Sound Convergence Zone. For in its swirling mists and fleeting rains, we find a glimpse of the wondrous dance of nature.

Until next time, weather aficionados, keep your eyes on the skies and your hearts open to the marvels of the atmospheric world.

_____________________________

Evaluation:  A lot of technical errors.  The convergence is NOT produced by ocean air hitting air from the interior.  The precipitation is NOT from the northern to the southern shores of Puget Sound.  Many more things are wrong.  My grade:  F.


Now let's try the same prompt with Google's Gemini AI app:

_________________________________________

The Persistent Puget Sound Convergence Zone: A PNW Weather Staple

Ah, the Puget Sound Convergence Zone (PSCZ). Our moody friend that brings sunshine to some and drenches others, often within spitting distance of each other.  For those unfamiliar, the PSCZ is a band of clouds and, more importantly, precipitation that forms when prevailing winds encounter the Olympic Mountains.

Splitting Hairs (and Winds) Over the Olympics

Imagine air flowing west-to-east, like a giant river of air. The Olympic Mountains act like a giant rock in the stream, forcing the air to split around it. One branch travels north, the other south, before they come together again over Puget Sound. This "convergence" zone is where the magic (or should I say, moisture) happens.

As the air converges, it's forced upwards. Remember, as air rises, it cools. Cooler air holds less moisture, and bingo! - condensation and precipitation form. This is why you can be sipping a latte in a cozy cafe while your friend across the Sound is battling downpours.

Where's the Party? (The Rainy One, That Is)

The PSCZ isn't a stationary weather system. It tends to favor a sweet spot between Everett and north Seattle, but can meander as far south as SeaTac.  This creates a frustrating situation for forecasters (yours truly included) - predicting the exact path of this convergence zone can be a tricky business.

However, there are some clues.  North-south wind direction shifts are a dead giveaway - if you see northerly winds in Everett and southerly winds in Seattle, you know the PSCZ is probably setting up shop in between.

The Not-So-Gentle Giant

While the PSCZ is known for rain showers, it can pack a punch. Updrafts within the convergence zone can lead to thunderstorms and even heavier precipitation.  These downpours can cause localized flooding, so it's always wise to be aware of the PSCZ, especially during the fall and winter when these events are most common.

Living with the PSCZ

The PSCZ is a fact of life here in the Pacific Northwest. But hey, at least it keeps things interesting!  By understanding how it works, you can be better prepared for those sudden weather changes. Keep an eye on the forecast, especially for wind direction shifts, and you'll be one step ahead of the ever-shifting PSCZ.

Stay weather-aware, Seattle!

P.S. Got a PSCZ story? Share it in the comments below!

_______________________________

My Evaluation:  Not bad!  Most of the information is technically correct, FAR better than Chatgpt

Finally, sometimes I do blogs on "controversial" topics, such as the hype and exaggeration regarding climate change in local media (especially the Seattle Times).   I asked both chatgpt and Gemini their opinions of the Seattle Times ClimateLab efforts, which hopelessly hype global warming in contradiction to the best science.  Here are their answers:

I guess I better say on the job for a while...

March 16, 2024

Most Northwest Heatwaves are Local

 Northwest heatwaves are funny things.  

It is rare to have a heatwave over the entire region.   Instead, real warmth is generally restricted to a distinct subset of the region.

Why is this the case, you ask?  

Because of the complex regional terrain and land/water contrasts.


Since the regional waters are cold, onshore flow is cool, but offshore flow (particularly during the warm portion of the year) is warm.

Downslope warm is warm, since the air warms by compression as it sinks, and sinking kills clouds (and thus more sun).  Upslope flow is cooled by expansion in addition to associated clouds and precipitation.

Consider the "heatwave" of yesterday (Friday) and today (Saturday).  Let's start with the high temperatures on Friday around the Olympic peninsula.  Temperatures were in the fifties around Sequim, Port Angeles, and Port Townsend, but in the 70s south and southwest of the Olympics. 


TWENTY DEGREE DIFFERENCE!

Why?  Because the winds were generally northerly (from the north) over the lower atmosphere, so the northern Peninsula had cool air from off the Strait, plus upslope flow.  In contrast, the air sank down the southern slopes and warmed before it reached the warm zone to the southwest and south.

Today, Saturday, the regional flow turned more easterly, a direction that strengthens the downslope to the western slopes of the Cascades and Olympics.  With easterly flow, the warmest temperatures are often near the western foothills of mountain barriers.

The local high temperatures near and east of Seattle today  illustrate this (see below).

Temperature role to 80F in Carnation.  Mid-70s on the east side, but 50s and 60s near Puget Sound.  


There has been some talk in the media and some climate activist groups that the warmest temperatures are in south Seattle in the urban core. This is generally NOT true during western Washington heatwaves, which generally occur with easterly, downslope flow. The eastern side of the Metro area, away from the water and near the slopes, is generally warmest.  

Those poor folks in Duvall, Carnation, Monroe, North Bend, Issaquah, and other foothills towns.  If you really want to see this, below is a high-resolution simulation of the temperatures today at 2 PM around the central Sound area:

Finally, let's consider the southern portion of our region, from central Oregon into northern California, on Friday, a period of moderate easterly flow (see below).  Mid-70s on the coast, but only in the 50s over the desert area of eastern Oregon.   The offshore, easterly flow sank of two mountain ranges (Cascades and the coastal terrain) and the cool marine air was pushed offshore.


The simulated surface temperatures on Friday at 5 PM illustrate this temperature pattern even better:


Enjoy this warm interlude.  It won't last, by Wednesday the cool/wetness will return.  But it sure was wonderful today.  I even got to work on my vegetable garden.  😁



Another Northwest Bomb Cyclone with Localized Strong Winds

  Don't tell the media folks, but another midlatitude cyclone will be "bombing" off our coast today, with some local impacts. ...