El Niño Or No Niño?

It seems to be a little on the no-show side here in northern Baja, although it’s helping to fill southern Cal’s reservoirs which they keep in northern Cal
BY: TOM EMANUEL

You know how you wake up in the middle of the night and you’re in a sweat thinking that somebody is on your roof or climbing your trellis to get to the second floor? You listen hard for a minute. Nothing. Listen harder. Nothing. Finally, you relax and  drift back to sleep. Next morning you check around. Nothing. Well that was weird!

That is pretty much what happened with El Nino, at least in Baja and Southern California. We were terrorized by dire warnings about how this was going to be a Godzilla El Nino, even worse than the one in 1997-98 which caused 23,000 deaths world wide. The eastern and central Pacific ocean around the equator has been warmer than it has ever been. We were in for it! We were told to prepare for flooding, mud slides, and other kinds of rain-related disasters. Fix the roof ! Clean the gutters ! Buy out Home Depot!

What the hell happened?

Ahh see ahh, well …. It’s complicated.

We did get a whole lot of rain in the Pacific northwest and northern California, but most of it didn’t make it down to Southern California. And that’s a good thing, because southern California’s water is piped down from the north for use there, but most of the rain they get in southern California just runs off into the ocean. And we’ve got a good snow pack up there this year, about 95% of normal.  Of course, the rain and snow so far is not anywhere near enough to alleviate the five year drought in the state. But it is a very good start, with some reservoirs near capacity.

So here in Southern California and Baja what are we? Chopped liver in the precipitation department? Yeah, pretty much, at least so far, but the official rain season extends into May, so the fat lady hasn’t sung yet.

El Nino is one of the phases, (the other is La Nina), which describes fluctuations in the water temperature and atmosphere in the Equatorial Pacific ocean. Whenever the water temperature is greater than one degree Fahrenheit above normal, it is the start of an El Nino episode or fluctuation. These episodes typically last between nine months and a year. Ocean temperatures in the eastern equatorial Pacific have been at or above their record highest  for several months now, reaching more than five degrees higher than normal. That is the greatest El Nino temperature ever recorded.

So why are we not feeling the effects right here in Baja? Because the atmospheric response to a warm ocean varies according to what is happening in other areas of the world. An El Nino is not just a North American event. It is a worldwide phenomenon affecting the weather over the entire earth. But for purposes of this article we will concentrate on what happens to the southwestern United States and to northern Baja California because we’re mostly concerned about us. It’s all about us.

Typically in an El Nino year the persistent low over the Gulf of Alaska is enhanced, while the jet stream is moved south, resulting in much heavier precipitation than usual in the winter and spring months in Southern California. Typically there is also heavy thunderstorm activity in the eastern tropical Pacific. For instance Brazil has been feeling the very extensive effects of El Nino this year, experiencing massive flooding.

Usually heavy thunderstorms pump vast quantities of heat into the upper atmosphere which eventually makes its way north. This effect is called the Hadley Circulation. When the moisture laden heated atmosphere meets the huge temperature differential of cool Gulf of Alaska air, it increases the jet stream coming south forcing the warm moist air down and dumping lots of rain in the mid central areas roughly on a parallel with Hawaii.

But this year the Hadley Circulation has been even stronger and so the El Nino differential has been forced slightly north of where it usually takes place. That means the northwest Pacific areas of Washington and Oregon and Northern California have been taking the brunt of this El Nino. There has also been some effects from a warmer than usual Indian Ocean, and many climatologists have attributed some of what we are seeing there to global warming.

The jet stream over North America and Canada has been swept east and southward which accounts for the terrible winter experienced on the eastern seaboard this year. It also has drawn much more warmth up from the tropics and given Baja and Southern California record high temperatures. We did see a smattering of rain in early January with some tough winds. Some people lost their roofs. But really, when was the last time you remember temps in the 90’s in mid-February?

So what does it look like for the rest of this El Nino season in terms of rain and snow for Southern California? Weather gurus are sure of two things: 1) this is truly a super colossal El Nino, and 2) it is still with us. There is no agreement about whether the northern shift of the rain and snow weather pattern will continue in this way, or whether it will finally come south enough to splatter the Los Angeles, San Diego, Baja corridors with much needed rain. Most weather guys are saying the pattern may have moved along a timeline further into spring and early summer and that we could still see a wetter year than normal.

Climate predictions are a hazardous activity at best. The El Nino weather system is so huge and is affected by so many variables that even the most educated weather analysts have a tough time predicting the wiles of mother nature. You will note your local weather girl has a tough time getting the next three days right, much less serving up accurate predictions about El Nino.

So at this point there are a lot of crossed fingers among climatologists for more rain yet this year.  The bottom line is: we haven’t seen it yet and we don’t know if we will.  Come 4th of July we sit around and  talk about what happened with El Nino this year.

Oh, and that was probably just a cat scratching around on your roof.