Break Out the Umbrellas, Here Comes El Niño

For several years now we've been hearing about how all of us Southern Californian's are in a drought. We're told to save water at every opportunity, and there are constant threats of rationing and huge price increases.

Well, Mother Gaia has a habit of fixing that every few years with something known as "El Niño", a condition in the Pacific Ocean that can cause a dramatic increase in rainfall in our area. The last time this happened we had well over 30" of rain that season, in an area with a normal annual rainfall of 14". It was a mess.

According to this Orange County Register piece, a new El Niño is setting up:

The U.S. Climate Prediction Center, which said only a couple of weeks ago that an El Nino might arise in the equatorial Pacific, now says that the periodic natural climate change seems to be evolving rapidly. The result, if the forecast turns out to be right, could mean an unusually wet winter for drought-plagued Orange County. It also might mean that the monsoonal flow into this area will be much stronger this summer.

In an analysis (read it) of the monsoon season for southeast Arizona, the CPC says online, “The forecast for the second half of the monsoon remains uncertain due to what appears to be a rapid-developing El Nino. An El Nino, which is a warming of water temperatures across the tropical East Pacific Ocean, causes significant changes in both monsoon and jet stream patterns, as well as the number of tropical cyclones in both the eastern Pacific and Atlantic oceans.

“It is unusual for an El Nino to develop this early and rapidly in the summer, but it has happened before: in 1972, 1982, 1997 and 2004. It is too early to tell how strong the El Niño will be, or when it will begin to affect the atmosphere. Based on recent water temperature trends in the tropical Pacific, it appears that the atmosphere won’t begin to fully respond to the developing El Niño until mid August or September, which should allow the monsoon high to remain generally north and east of Arizona, and keep things active for much of the summer.

“However, when an El Niño develops rapidly in the summer months, the monsoon high can be pushed away from us into Mexico during the second half of the season as the jet stream strengthens and dips farther south along the west coast of the United States. This in turn can result in a significant rainfall decrease in August and September. However, the same jet stream changes, coupled with an increase in tropical cyclones along the Mexico coast due to the warmer than normal water temperatures, can draw considerable tropical moisture into Arizona during September and October. Thus, the El Niño development, and any jet stream changes it may cause, will be watched closely in the coming weeks.”

I remember the 1997 event particularly well. On one memorable Saturday we had 6 1/2" of rain in that single day. I've never seen anything like it, with the exception of the Texas hurricane I experienced in 1970. We had a wooden deck in our backyard and I could see the water building up under the deck and threatening to flood into the house. I had to get out there in the downpour with a pick-axe and tear up a section of the deck to release the water from underneath. My kids thought it was pretty funny watching dad out in that mess.

I must admit, if the monsoon flow moves more strongly into Southern California that can be kind of entertaining because it usually brings thunderstorms with it, something we rarely see around here.

We need the rain, but we don't need it faster than an inch or two a day. This could be an eventful fall and winter.