Saturday, April 11, 2015

Long Range Climate Models Show Cold, Snowy SST Pattern for 2015-2016 Winter

I'll bite the bullet and be 'that one person' who starts discussing next winter far too early. Long range climate models are showing a sea surface temperature anomaly prognosis that could be conducive to another cold and snowy winter, particularly along the East US.

Climate Prediction Center
The graphic above shows mean sea surface temperature anomalies from seven different long range models, valid for November 2015. There are a few areas of interest on the chart above. We'll begin in the Gulf of Alaska and work our way south from there.

In the Gulf of Alaska, the ensemble mean of models tells us that the warm pool we have seen the last two winters will only solidify itself for a third consecutive winter, with temperature anomalies definitively above normal in that area.

So what would that warm pool in the Gulf of Alaska mean for us? The chart above shows the correlation between the Pacific Decadal Oscillation, and temperatures in the United States in the winter. For example, if the Pacific Decadal Oscillation (PDO) were negative (which would be signified by cold waters in the Gulf of Alaska), the negative correlation area over the South and East US tells us temperatures would be warm there. Similarly, temperatures would be colder than normal in the positive correlation area.
As we head into the coming winter, it is expected that the pool of warm waters over the Gulf of Alaska will persist, as climate models above suggest. Using our chart from the ESRL, a positive PDO correlates to below-normal temperatures in the South and East, and warmer than normal temperatures in the West. This is not a good preliminary outlook for those in the Southwest undergoing a devastating drought.

The other key item we see on this prognosis is a large swath of above-normal sea surface temperatures along the Equator in the Pacific. This is the El Nino phenomenon.

In a typical El Nino winter, warmer than normal conditions will prevail along the south Alaskan shore into western Canada and the Pacific Northwest. Wetter and cooler than normal conditions are then favored in the Southwest, South-central, and Southeast United States, all the way up along the East Coast, though that area is not depicted with those anomalies. Drier conditions then prevail in the Ohio Valley.

Last season, there was talk of an El Nino brewing for the winter, which it did end up doing, but very late in the season. Part of the reason the El Nino didn't evolve as eagerly as forecasted was likely how Equatorial Pacific waters were rather cool in the spring before last winter, which is not a good breeding ground for the El Nino. This spring, however, we are already under a weak El Nino, and climate models expect that to intensify as we push into the fall. If this happens, the forecast for next winter could once again be one of snow and chilly weather for the East.

To summarize:

- Climate models are indicating portions of the South and East US may see favorable conditions for another cold and snowy/wet winter in 2015-2016.



Anonymous said...

The problem is the forecast for sea surface temperatures anomalies is wrong.

El Nino will be much weaker.

North Atlantic waters much colder.

Christopher Ebie said...

Groan....I was hoping for something different next year. I hope this changes before next winter.

Anonymous said...

As always Andrew, many thanks for this early heads-up of what Winter 2015-16 may be like for those of us in the Midwest and East. It definitely helps nudge us to be preparing early and thoroughly.

Anonymous said...

I live 20 miles west of Boston and as of yesterday we still have snow on the ground. I know you are cutting edge and all, but do you really think its necessary to discuss next winter already?


Frank-o said...

Hmmmmmmm.....The "FIRST" clue here is ""Long Range Climate Models Show"......There is no "FORECAST" here. Andrew is simply showing." MODEL RUNS" ...Get a clue..."Anonymous said" there is "NO PROBLEM" here......Thanks for the great article Andrew!....Most excellent read!!

Anonymous said...

Can't we at least enjoy a few months of warmth before having to think about serving another 5-month sentence in the freezing Siberian hellhole called the Northeast?

Shawn said...

What could this entail for Missouri for the 2015/2016 winter Andrew?

Because although we had some cold days and nights and some snow Missouri's winter was basically a bust in 2014/2015!

Anonymous said...

Well Andrew, fingers crossed whatever comes this winter it brings MUCH needed rain to all of the west. And hoping that the east doesn't hog all the snow, Indy's biggest snowfall this year was eight inches on March 1st. Winter lovers were heart broken.
Thanks for looking ahead for us! Always appreciate the updates.