El Nino and your interesting summer

I've had a number of "Ask Mike's" recently about the El Nino conditions strengthening off the coast of South America, and specifically "is this why we've had such a wet summer?"

Let's start with the easy one first..."is El Nino responsible for the buckets of rainfall we've had over the past month or so?" and the answer is a resounding NO. It's just one of those years (kind of like 1997).

Even though an El Nino is building (more about that in just a bit), its effects are minimal in North America during the Summer and Fall.

Now then, just what is El Nino? It's an ocean an atmospheric condition diagnosed by warmer-than-average sea surface temperatures off the coast of Peru. It may be measured locally, but the effects are global.

As an El Nino strengthens, the trade winds that usually flow from South America to Indonesia either die away or reverse. Indonesia (and Australia) often go into long-term drought as a result, often followed by wildfires.

The entire global wind flow is affected, and as a result, during El Nino years (which occur every 7 to 14 years), the southeast usually gets more rainfall, the northeast more snow, and here at home in Colorado, we can do almost anything. That seems like sidestepping the question, but during strong El Nino years, we've been wetter-than-average, drier-than-average and average.

There are usually fewer Atlantic hurricanes when El Nino is strong, which may explain why the hurricane forecast for the season has just been downgraded to a lower number.

Want to know more? Here's a good place to start http://www.elnino.noaa.gov/.