First, how much snow is in the mountains right now? Below left is the total snow water equivalent (SWE) of the snow pack we have today, and to the right is what was on the ground last year. There is already significant snow in the north Cascades and the mountains of southern BC. Last year, practically nothing.
Here is a picture today (Oct 28th) from Whistler in BC. Looks promising to me.
So what about the coming winter? The only tool we have that has any real skill (and even that is not perfect), is the correlation between El Nino/La Nina and the snowpack over our region. El Nino years are associated with warm sea surface temperatures over the central/eastern tropical Pacific, and La Nina years, colder than normal
La Nina years, and particularly strong ones, bring healthy mountain snowpacks.
El Nino years, poor ones.
In between or neutral years, average snowpack.
This correlation is useful but imperfect. For example, last winter we started with a strong El Nino and the snowpack turned out to be near normal.
Based on sea surface temperature (SST) measurements over the tropical Pacific, we are now in a weak La Nina situation. The figure below shows the SST anomaly (difference from normal) for the critical Nino 3.4 region (see map beneath). Blue is colder than normal. Neutral years have small SST anomalies (within .5C of normal). Weak La Nina years are colder than normal by .5 to 1 C. We now are in a weak La Nina situation.
According to the official Climate Prediction Center (CPC) and Columbia IRI probabilistic forecast, we will stay in La Nina for several more months (blue color) before we slide into neutral (or La Nada) conditions later in the winter.
And according to a collection of La Nina/El Nino forecasting models, we will stay with a weak/marginal La Nina for the winter.
Strong La Nina conditions tend to bring colder/marginally wetter conditions to the Northwest, with more snow than normal in the mountains. Weak La Nina years like this one typically bring near normal snowpack in the Cascades.
Now there is something else we should consider, the phenomena that brings terror to all skiers: the BLOB, which is the occurrence of warm water over the Northeast Pacific. The BLOB is not good for NW snow. The latest SST analysis shows a weakening of the BLOB with over the central NE Pacific (blue colors).
Bottom line: Our best estimate is for a normal snow year in the Cascades.
And to get my ski friends excited, here is the 72 hr snow total ending 5 PM Wednesday. Several feet in the Coast Mountain of BC. and a half foot in the north Cascades. The folks at Whistler, must be, well whistling.
I 732 and Skiing.
High-resolution climate simulations show emphatically that rising temperatures forced by increasing CO2 levels will decimate Northwest mountain snowpacks. There is substantial confidence in this projection.
So if you care about skiing, or water resources in the Northwest, or our local environment, please vote for I-732, the carbon tax swap.
This has to be one of the most progressive, wise initiatives in the history of WA state. Supported by both Democrats and Republicans, it takes carbon and GIVES ALL THE MONEY BACK to WA State citizens and businesses. Economists consider carbon taxes the most effective way to get CO2 under control and the giving the money back (by reducing the sales tax by 1 % and more) helps repair the crazy, regressive tax system in the State. Solomon could not have done better.
There is a lot of false information being spread about I-732, with some claiming that it is not revenue neutral. This can easily be disproved.
The big carbon polluters are pushing a lot of bad information and lies about the impacts of I-732. Please go to the I-732 web site to learn the truth.
The entire nation is watching us. Please join me, and much of the local climate scientist community, in supporting this extraordinarily positive measure.