Written by Sig Silber
Fabius Maximus has posted an excellent article about the recent media coverage of what appears to be a current El Nino in progress.For those not familiar (maybe there are a few?) El Nino refers to a shifting of the physical distribution of warmer and cooler water in the Pacific controlled in part by changes in the strength of the prevailing Easterlies such that the central and eastern Pacific surface temperatures are warmer than usual and North and South American weather patterns are affected as well as Asian weather patterns through complex mechanisms. That is an oversimplification, but will do for now.) Fabius Maximus leads his article with a criticism of media for writing sensationalized articles (especially wild headlines which he calls “clickbait”). I want to amplify on some of the points FM makes about El Nino.
I would have chosen a different title but this is an excellent article in many ways. The level of hysteria about an El Nino or a Super El Nino is amazing and yet the different phases of the ENSO cycle do have a significant impact on weather in pretty much every part of the World. The ENSO cycle is really about where the warm water in the Pacific along the equator is located and that determines convection patterns. With an El Nino, the Warm Water is shifted to the east so clouds form further east than usual.
FM makes many good points, especially that our ability to predict the specific impacts is limited and we try to do this with about four different indices which are useful but not sufficient to predict precisely what the impacts will be. The Equatorial Pacific is a large area and the nature of an El Nino is not just the surface but the subsurface distribution of warm water and the winds at different altitudes so four indices provide only a general characterization of a particular El Nino or La Nina (conditions deviating from normal in the opposite direction from El Nino). At any point in time there are many different weather phenomena occurring, not just what is occurring in the Equatorial Pacific, so attempting to attribute everything to an El Nino is problematical. It is very important but it is not the only thing that is going on.
Of many weather terms, “El Nino” is recognizable so people respond to it and thus the news media find it to be an easy way to get our attention. In the Northern Hemisphere, it is useful in increasing the accuracy of weather forecasts out as far as nine months especially in the Fall, Winter and Spring but in the Southern Hemisphere they have an other somewhat similar cycle the Indian Ocean Dipole (IOD) that sometimes is in sync with El Nino and sometimes not so the predictions for part of the Southern Hemisphere are complicated. Latin America especially near the Equator is directly impacted by El Nino. Australia and India and West Africa may be more impacted by the IOD.
I think the message of the Fabius Maximus article is to rely on scientific sources and not get carried away by the media. In recent years we have had a Super El Nino Alert almost every year and generally Super El Ninos are actually fairly rare. According to the data that the author presented these occur about every eight years on average and obviously the World has survived them. Same goes for the opposite extreme of the ENSO cycle called La Nina.
This El Nino appears to be quite strong but unusual in many regards. For a number of different reasons it does not remind me of the 1997 El Nino but every week the analogs posted by NOAA as part of their short term forecasting work change so it would appear that this El Nino is not exactly like any prior El Nino – so it might have more or less impact than the ONI number reported by the Meteorological Agencies.
It is probably best to just take it in stride and plan some ski trips out west. It most likely will be a good snow year.
Editor’s note: Sig Silber writes a comprehensive global weather and climate review every week as a GEI Feature. He tracks the progress of this El Nino each Monday, not only using data from NOAA (U.S. National Oceanic and Atmospheric Administration) but also reporting what data and analysis is coming from other sources, such as Japan and Australia. For another article he wrote on “fickle” El Ninos, see NOAA Quietly Rescinds Faux El Nino (GEI News).