Misinformation in the Seattle TImes Anount Drought, Snowpack, and Climate Change

It is frustrating to read stories by the ClimateLab folks in the Seattle Times that are simply not true.

Another story was published yesterday that predicts a major drought year ahead due to poor snowpack.

A poor snowpack driven by climate change.

The problem:   their claims are easily shown to be false

The Truth

In December,  the region was hit by several strong atmospheric rivers that produced massive precipitation.  

Soils became saturated, rivers flooded, and all regional reservoirs were filled to above normal levels.

Atmospheric rivers are associated with warm conditions, thus working against snowpack accumulation.  And January was relatively dry and warm aloft due to high pressure aloft.

Consider the critically important Yakima River reservoir system.  

The heavy rain caused a huge increase in reservoir storage (blue line).  Higher than ANY TIME OF LAST YEAR and equivalent to early May levels in a normal year.

Yakima water storage will easily reach 1 million acre-feet just with rain and melt last month, resulting in a full reservoir system.

To provide 100% of the water requested, the Yakima System needs to deliver 2.3 million acre feet, with the remainder coming from melting snowpack AND late spring/early summer rainfall.  

We are only halfway through the snow accumulation season in the Cascades, and there is PLENTY of opportunity to gain much more snowpack.

Currently, the snowpack in the Yakima Basin is roughtly 48% of normal, and this percentage will only increase...and substantially.   

Evem of there was no additional snow this year, just rain, one would expect about 750,000 acre-feet from melting the snow that is not on the ground.

So WITH NO SNOW, we would get to  1.75 million acres feet.   76% of normal.

Snowpack percentage of normal yesterday for the Yakima drainage.

But we are only about halfway through the snow accumulation season, and models are going for a cooler/snowier period ahead.  For example, the European Center model predicts lots of mountain snow through February 22:

Extended seasonal forecasts are for a wet spring with normal temperatures (see below).

That means plenty of snow.

Moving beyond the Yakima River situation, snowpack is above normal over the eastern slopes of the North Cascades, and the snowpack supporting the important Columbia Basin is normal (and the water level behind the Grand Coulee dam is above normal).  

Regional reservoirs are in very good shape.

No drought.

Even Worst

As bad as all the unsupportive Seattle Times claims of regional drought, there is clear misinformation about the cause of the lack of snow last month.

The Seattle Times claims it is because of warming due to climate change."

Substantial portions of the article push the global warming origin of the thin snowpack.

This is demonstrably untrue.

The last month was warm and dry because of the persistent ridge of high pressure over the region.  

The map below shows the anomaly (or difference) from normal of the heights (equivalent to pressure) at 500 hPa (about 18,000 ft).  

A very strong ridge of high pressure over the western U.S. and an intense trough (low pressure) over the eastern U.S.

This pattern suppressed snow over the Western U.S. and ENHANCED snow over the East.

Such patterns have little to do with global warming (there is a VERY published literature on this).

The claims of the Seattle Times that our low snowpack is connected with global warming are simply false, with the impact of global warming on regional snow quite modest, something proven by the lack of downward trend in the observed Northwest snowpack over the past decades. (see below, SWE is snow water equivalent, the amount of water in the snowpack).

The continued deceptive information from the Seattle Times on climate issues is very worrisome and shows the dangers of journalism funded by advocacy groups (the Seattle Times Climate Lab sponsors).

Super Inversion But Decent Air Quality

I will define a Super Inversion when temperature increases by more than 20F in the lower atmosphere (from the surface to roughly 3000 ft).

As noted many times in this blog, temperatures normally decrease with height, but in inversion situations that opposite occurs.

Inversions represent stable situations that suppress vertical mixing, and thus encourages low level fog and pollution.

The lower-atmosphere temperature structure near SeaTac Airport is shown below, based on observations taken by aircraft arriving or leaving the airport.

Around 43 F near the surface and 63F around 2200 ft.  Wow.

The effects of the inversion were obvious in the surface temperatures around our region (see below).   East of Seattle, an observation location on the slopes of Squak Mountain was 51 F, but 33 F was observed at lower elevations not more than a mile away.

Or consider the situation near Route 2.  57F near  Gold Bar but near freezing a few miles away to the west at lower elevations.

The strong inversion was evident in the observations from the balloon-based radiosonde at Quillautye on the WA coast (below).  The red line is temperature (in °C), and the height (y-axis) indicates pressure (700 in about 10,000 ft, 850 is about 5000 ft). 

At this location, temperature increases by 13 °C (23F) in the lower few thousand feet.   Wow again.

Mama Mia!  That is an inversion.

Such strong low-level inversions result in an atmosphere lens that bends the radar signal down to the surface.  

And it happened this morning, as the radar beam from the Langley Hill radar near Hoquium was bent to the ocean surface and was reflected back, creating a false echo that suggested offshore precipitation (see below).  No precipitation was there.

Finally, what about air quality?  Normally, inversions produce poor low-level air quality, since inversions suppress vertical motion in the atmosphere, allowing low level polution to concentrate.

Here are the latest air quality maps over the region.  Generally good air quality except for an area in the South Sound.

But why?  Inversions can suppress vertical mixing, allowing pollutants to concentrate.

According to an associate of mine in the Puget Sound Clean Air Agency, the relatively warm temperatures (high around 60F) today result in less burning of wood, a prime emitter of particulates.    And, of course, there are no wildfires going on this time of the year.

The warm surface temperatures during the day also weaken the inversion at low levels, improving air quality.