WeatherWatcher: El Niño - what does it mean for you?

On August 4th, 2011, the National Weather Service Climate Prediction Center released their latest discussion and ENSO (El Nino/Southern Oscillation) forecast. If you're a fan of this cooler and wetter weather, you are in luck! For those who miss the sun and the warm, you may have to wait another year before a warm summer arrives.

The atmosphere still reflects La Nina weather patterns

Currently the ocean sea surface temperatures over the equatorial Pacific Ocean are presently in an ENSO-neutral pattern. However because of the unusually strong La Nina we had last winter and spring, the atmosphere is still reflecting that of La Nina weather patterns globally. 

It is expected that we will continue to have ENSO-neutral conditions lasting through most of Fall 2011, however there is now in some forecast models showing a 50/50% chance that we may either be an ENSO-neutral winter, or return to a La Nina winter.

What does this mean for us?

Due to the atmospheric conditions continuing to exhibit La Nina like patterns, we will continue to have our cooler than normal summer, for those folks that like 90ºF + degree summer days, I'm sorry to say, we probably won't have any this season. 

The remainder of our summer will continue to be cool, and pleasant, with continued moderate to strong marine air flow influenced weather, so more morning clouds, afternoon sunshine, highs averaging around the low-mid 70's, with maybe another 2-4 days cracking the 80ºF mark. September will probably be wet, maybe wetter than average, with a few of sunny days still mixed in.

Stormy weather and winter snow ahead

Now here's where it gets interesting. If ENSO-neutral conditions continue through fall and winter, we will probably have a lot more storms, by storms I mean wind storms, rain storms, and in the winter, there is the likely event we may have one or two significant snow events. 

Neutral years often produce some of the biggest storm events in our area. This is owing to the Jet stream being pointed right at Washington state. If we have an ENSO-La Nina winter again, not only would it be 2 years in a row, but typically if it is two years in a row, the colder and wetter pattern effects are often more extreme. In other words, this winter has the potential to be even colder, and wetter than last winter, which could also generate more snow events than average.

Next forecast to be released in September

As we get into the fall I will have a better idea of what this fall, and first half of winter may have in store for us. The next forecast for ENSO is scheduled to be released on September 8th, 2011, by then models should have a better idea of what ENSO conditions will be this coming fall and winter.

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.