New Strategy for Dealing With ENSO

The El Nino-Southern Oscillation (ENSO) has incredible influence on the distribution of global temperatures and precipitation. There are two phases to this phenomenon including the warm phase (El Niño) which is observed when the Pacific Ocean is observed to be colder than average. However, one thing that has been troubling is the idea that as the earth continues to warm, would that mean that the Pacific Ocean would be perpetually in the warm phase? Would La Niña seemingly disappear? Or, will we simply need to just redefine what is considered “warm” and what is considered “cold”? These questions have to be answered as the central tropical Pacific continues to warm as demonstrated by the figure of 30-year average temperatures. We currently define phases of ENSO based upon whether Pacific Ocean temperatures are 0.5°C above (El Niño) or below (La Niña) average. Since the average temperature is changing with time, the CPC has recently begun using five year periods in the historical record centered around a 30 year average in order to calculate La Niña and El Niño. This enables us to calculate the ENSO phase based on the very latest climatology, not what the average was decades ago. For example, 1950-1955 are compared against the 1936-1965 average. This is actually quite effective until we consider the 2001-2005 period, since that will require more years of data, 1985-2015. CPC will use the most recent 30-year average until those years have passed, which for the 2001 and 2005 period would be 1981-2010. For additional reading please see: http://www.climatewatch.noaa.gov/article/2013/in-watching-for-el-nino-and-la-nina-noaa-adapts-to-global-warming.

Cold Advisory for Newborn Livestock: The cold advisory for Newborn Livestock (CANL) system is up and running. While we have been running it experimentally for about the last five years, it will now be an official product from the National Weather Service. You can find the graphics, and the information on how the system is run on our website in the headlines sections, or bookmark this URL: http://www.wrh.noaa.gov/ggw/canl/canl.html.