WeatherWatcher: El Niño / Southern Oscillation Status and Forecast

Carl's Shoreline Weather Station

Current ENSO status: La Niña Advisory as of November 10, 2011

La Niña is expected to continue through the Northern Hemisphere winter of 2011-2012. 

So far this has been a weak La Niña, however forecast models are split about 50/50% from a weak to a moderate-strong La Niña. 

Historically, a La Niña in a 2nd winter in a row following an ENSO neutral summer stays weak. 

However, this year we have an added factor. The Pacific Decadial Oscillation (A.K.A. P.D.O) is currently in a cold phase. La Niña's during a cold P.D.O. typically are stronger and more frequent. I suspect this will be at least a moderate La Niña winter. La Niña is expected to peak mid-late November through January, and is expected to slowly dissipate February 2012 and on.

Plan for the worst of winter weather
Photo by Carl Dinse

How does this affect us?

Winter: We will be having a much colder than normal winter, and possibly wetter as well. I am actually expecting at least 3 snow events this winter. We will see many "winter" storms. Meaning several wind storms, rain storms, and yes probably a few snow events as well.

With this knowledge I urge everyone to prepare for the worst of winter weather, I believe it is possible we could have one of our worst winters in over a decade.

Spring: Early spring will be colder and wetter than normal, however it looks like it may ease up around mid April to return to normal spring weather, with normal temperatures.

My judgment on our local weather is based on my past experience studying the effects of ENSO locally and of studying historical weather events that occurred here and in the greater Seattle area since record keeping begin, coordinated with the known past of the ENSO status each year.