Econintersect Weather and Climate Forecast Update
Written by Sig Silber
If anything, the odds of El Nino coming this summer have improved. There is less confidence in the 6 – 14 day forecast but with the unique characteristic of a strong influence in the U.S. from high pressure in Northeast Asia. Weather wise, the World is interconnected.
It does not matter whether you look at the situation from the U.S. looking west or from Australia looking east. Everyone is working with the same data and last week the Australia Bureau of Meteorology issued this statement:
“El Niño likely in 2014 Issued on Tuesday 22 April 2014
The likelihood of El Niño remains high, with all climate models surveyed by the Bureau now indicating El Niño is likely to occur in 2014. Six of the seven models suggest El Niño thresholds may be exceeded as early as July.
The Pacific Ocean has been warming along the equator over recent weeks, with continued warming in the central Pacific likely in coming months. Another burst of westerly winds is presently occurring in the western Pacific, and is likely to cause further warming of the sub-surface.
El Niño has an impact across much of the world, including below average rainfall in the western Pacific and Indonesian regions, and increased rainfall in the central and eastern Pacific. For Australia, El Niño is usually associated with below average rainfall, with about two thirds of El Niño events since 1900 resulting in major drought over large areas of Australia.
The Indian Ocean Dipole (IOD) is currently in a neutral state. Model outlooks currently suggest the IOD is likely to remain neutral through late autumn and early winter, with two of the five models surveyed suggesting a positive IOD may develop by early spring. Positive IOD events often coincide with El Niño and are typically associated with large parts of southern and central Australia experiencing lower rainfall than usual“.
Given the inceasing likelihood of an El Nino coming this summer, I thought it might be useful to look at the history of the so-called ONI index which reflects the climatology adjusted sea-surface temperatures in the area of the Pacific which appears to be most indicative of the phase of ENSO which we are experiencing. Red is associated with El Nino. Blue with La Nina.
Year | DJF | JFM | FMA | MAM | AMJ | MJJ | JJA | JAS | ASO | SON | OND | NDJ |
1950 | -1.4 | -1.3 | -1.2 | -1.2 | -1.1 | -0.9 | -0.6 | -0.5 | -0.4 | -0.5 | -0.6 | -0.7 |
1951 | -0.8 | -0.6 | -0.4 | -0.2 | 0.0 | 0.4 | 0.6 | 1.0 | 1.1 | 1.2 | 1.1 | 0.9 |
1952 | 0.6 | 0.4 | 0.3 | 0.3 | 0.3 | 0.1 | -0.1 | 0.0 | 0.2 | 0.2 | 0.2 | 0.3 |
1953 | 0.5 | 0.6 | 0.6 | 0.7 | 0.7 | 0.7 | 0.7 | 0.7 | 0.8 | 0.8 | 0.8 | 0.8 |
1954 | 0.7 | 0.5 | 0.1 | -0.4 | -0.5 | -0.5 | -0.6 | -0.7 | -0.8 | -0.7 | -0.7 | -0.7 |
1955 | -0.7 | -0.7 | -0.7 | -0.8 | -0.8 | -0.8 | -0.8 | -0.7 | -1.1 | -1.4 | -1.7 | -1.6 |
1956 | -1.1 | -0.8 | -0.6 | -0.5 | -0.5 | -0.5 | -0.5 | -0.6 | -0.5 | -0.5 | -0.5 | -0.5 |
1957 | -0.3 | 0.1 | 0.4 | 0.7 | 0.9 | 1.0 | 1.1 | 1.2 | 1.2 | 1.3 | 1.5 | 1.8 |
1958 | 1.8 | 1.6 | 1.2 | 0.9 | 0.7 | 0.6 | 0.5 | 0.3 | 0.3 | 0.4 | 0.5 | 0.6 |
1959 | 0.6 | 0.6 | 0.5 | 0.3 | 0.2 | -0.1 | -0.2 | -0.3 | -0.1 | 0.0 | 0.1 | 0.0 |
1960 | -0.1 | -0.2 | -0.2 | -0.1 | -0.1 | 0.0 | 0.1 | 0.2 | 0.2 | 0.1 | 0.1 | 0.1 |
1961 | 0.0 | 0.0 | 0.0 | 0.1 | 0.3 | 0.4 | 0.2 | -0.1 | -0.3 | -0.3 | -0.2 | -0.1 |
1962 | -0.2 | -0.3 | -0.3 | -0.3 | -0.2 | -0.2 | 0.0 | -0.1 | -0.2 | -0.3 | -0.4 | -0.5 |
1963 | -0.4 | -0.2 | 0.1 | 0.3 | 0.3 | 0.5 | 0.8 | 1.1 | 1.2 | 1.3 | 1.4 | 1.3 |
1964 | 1.1 | 0.6 | 0.1 | -0.4 | -0.6 | -0.6 | -0.6 | -0.7 | -0.8 | -0.8 | -0.8 | -0.8 |
1965 | -0.6 | -0.3 | 0.0 | 0.2 | 0.5 | 0.8 | 1.2 | 1.5 | 1.7 | 1.9 | 1.9 | 1.7 |
1966 | 1.4 | 1.1 | 0.9 | 0.6 | 0.4 | 0.3 | 0.3 | 0.1 | 0.0 | -0.1 | -0.1 | -0.2 |
1967 | -0.3 | -0.4 | -0.5 | -0.4 | -0.2 | 0.1 | 0.1 | -0.1 | -0.3 | -0.3 | -0.3 | -0.4 |
1968 | -0.6 | -0.8 | -0.7 | -0.5 | -0.2 | 0.1 | 0.4 | 0.5 | 0.5 | 0.6 | 0.8 | 1.0 |
1969 | 1.1 | 1.1 | 1.0 | 0.9 | 0.8 | 0.6 | 0.5 | 0.5 | 0.8 | 0.9 | 0.9 | 0.8 |
1970 | 0.6 | 0.4 | 0.4 | 0.3 | 0.1 | -0.2 | -0.5 | -0.7 | -0.7 | -0.7 | -0.8 | -1.0 |
1971 | -1.2 | -1.3 | -1.1 | -0.8 | -0.7 | -0.7 | -0.7 | -0.7 | -0.7 | -0.8 | -0.9 | -0.8 |
1972 | -0.6 | -0.3 | 0.1 | 0.4 | 0.6 | 0.8 | 1.1 | 1.4 | 1.6 | 1.9 | 2.1 | 2.1 |
1973 | 1.8 | 1.2 | 0.6 | -0.1 | -0.5 | -0.8 | -1.0 | -1.2 | -1.3 | -1.6 | -1.9 | -2.0 |
1974 | -1.9 | -1.6 | -1.2 | -1.0 | -0.8 | -0.7 | -0.5 | -0.4 | -0.4 | -0.6 | -0.8 | -0.7 |
1975 | -0.5 | -0.5 | -0.6 | -0.7 | -0.8 | -1.0 | -1.1 | -1.2 | -1.4 | -1.5 | -1.6 | -1.7 |
1976 | -1.5 | -1.1 | -0.7 | -0.5 | -0.3 | -0.1 | 0.2 | 0.4 | 0.6 | 0.7 | 0.8 | 0.8 |
1977 | 0.6 | 0.6 | 0.3 | 0.3 | 0.3 | 0.4 | 0.4 | 0.4 | 0.5 | 0.7 | 0.8 | 0.8 |
1978 | 0.7 | 0.5 | 0.1 | -0.2 | -0.3 | -0.3 | -0.3 | -0.4 | -0.4 | -0.3 | -0.1 | -0.1 |
1979 | -0.1 | 0.1 | 0.2 | 0.3 | 0.2 | 0.0 | 0.0 | 0.2 | 0.3 | 0.5 | 0.5 | 0.6 |
1980 | 0.5 | 0.4 | 0.3 | 0.3 | 0.4 | 0.4 | 0.3 | 0.1 | -0.1 | 0.0 | 0.0 | -0.1 |
1981 | -0.4 | -0.6 | -0.5 | -0.4 | -0.3 | -0.3 | -0.4 | -0.4 | -0.3 | -0.2 | -0.2 | -0.1 |
1982 | -0.1 | 0.0 | 0.1 | 0.3 | 0.5 | 0.7 | 0.7 | 1.0 | 1.5 | 1.9 | 2.1 | 2.2 |
1983 | 2.2 | 1.9 | 1.5 | 1.2 | 0.9 | 0.6 | 0.2 | -0.2 | -0.5 | -0.8 | -0.9 | -0.8 |
1984 | -0.5 | -0.3 | -0.3 | -0.4 | -0.5 | -0.5 | -0.3 | -0.2 | -0.3 | -0.6 | -0.9 | -1.1 |
1985 | -1.0 | -0.9 | -0.7 | -0.7 | -0.7 | -0.6 | -0.5 | -0.5 | -0.5 | -0.4 | -0.4 | -0.4 |
1986 | -0.5 | -0.4 | -0.2 | -0.2 | -0.1 | 0.0 | 0.3 | 0.5 | 0.7 | 0.9 | 1.1 | 1.2 |
1987 | 1.2 | 1.3 | 1.2 | 1.1 | 1.0 | 1.2 | 1.4 | 1.6 | 1.6 | 1.5 | 1.3 | 1.1 |
1988 | 0.8 | 0.5 | 0.1 | -0.2 | -0.8 | -1.2 | -1.3 | -1.2 | -1.3 | -1.6 | -1.9 | -1.9 |
1989 | -1.7 | -1.5 | -1.1 | -0.8 | -0.6 | -0.4 | -0.3 | -0.3 | -0.3 | -0.3 | -0.2 | -0.1 |
1990 | 0.1 | 0.2 | 0.3 | 0.3 | 0.2 | 0.2 | 0.3 | 0.3 | 0.4 | 0.3 | 0.4 | 0.4 |
1991 | 0.3 | 0.2 | 0.2 | 0.3 | 0.5 | 0.7 | 0.8 | 0.7 | 0.7 | 0.8 | 1.2 | 1.4 |
1992 | 1.6 | 1.5 | 1.4 | 1.2 | 1.0 | 0.7 | 0.3 | 0.0 | -0.2 | -0.3 | -0.2 | 0.0 |
1993 | 0.2 | 0.3 | 0.5 | 0.6 | 0.6 | 0.5 | 0.3 | 0.2 | 0.2 | 0.2 | 0.1 | 0.1 |
1994 | 0.1 | 0.1 | 0.2 | 0.3 | 0.4 | 0.4 | 0.4 | 0.4 | 0.5 | 0.7 | 1.0 | 1.2 |
1995 | 1.0 | 0.8 | 0.6 | 0.3 | 0.2 | 0.0 | -0.2 | -0.4 | -0.7 | -0.8 | -0.9 | -0.9 |
1996 | -0.9 | -0.8 | -0.6 | -0.4 | -0.3 | -0.2 | -0.2 | -0.3 | -0.3 | -0.3 | -0.4 | -0.5 |
1997 | -0.5 | -0.4 | -0.1 | 0.2 | 0.7 | 1.2 | 1.5 | 1.8 | 2.1 | 2.3 | 2.4 | 2.3 |
1998 | 2.2 | 1.8 | 1.4 | 0.9 | 0.4 | -0.2 | -0.7 | -1.0 | -1.2 | -1.3 | -1.4 | -1.5 |
1999 | -1.5 | -1.3 | -1.0 | -0.9 | -0.9 | -1.0 | -1.0 | -1.1 | -1.1 | -1.3 | -1.5 | -1.7 |
2000 | -1.7 | -1.5 | -1.2 | -0.9 | -0.8 | -0.7 | -0.6 | -0.5 | -0.6 | -0.6 | -0.8 | -0.8 |
2001 | -0.7 | -0.6 | -0.5 | -0.4 | -0.2 | -0.1 | 0.0 | 0.0 | -0.1 | -0.2 | -0.3 | -0.3 |
2002 | -0.2 | 0.0 | 0.1 | 0.3 | 0.5 | 0.7 | 0.8 | 0.8 | 0.9 | 1.2 | 1.3 | 1.3 |
2003 | 1.1 | 0.8 | 0.4 | 0.0 | -0.2 | -0.1 | 0.2 | 0.4 | 0.4 | 0.4 | 0.4 | 0.3 |
2004 | 0.3 | 0.2 | 0.1 | 0.1 | 0.2 | 0.3 | 0.5 | 0.7 | 0.8 | 0.7 | 0.7 | 0.7 |
2005 | 0.6 | 0.4 | 0.3 | 0.3 | 0.3 | 0.3 | 0.2 | 0.1 | 0.0 | -0.2 | -0.5 | -0.8 |
2006 | -0.9 | -0.7 | -0.5 | -0.3 | 0.0 | 0.1 | 0.2 | 0.3 | 0.5 | 0.8 | 1.0 | 1.0 |
2007 | 0.7 | 0.3 | -0.1 | -0.2 | -0.3 | -0.3 | -0.4 | -0.6 | -0.8 | -1.1 | -1.2 | -1.4 |
2008 | -1.5 | -1.5 | -1.2 | -0.9 | -0.7 | -0.5 | -0.3 | -0.2 | -0.1 | -0.2 | -0.5 | -0.7 |
2009 | -0.8 | -0.7 | -0.5 | -0.2 | 0.2 | 0.4 | 0.5 | 0.6 | 0.8 | 1.1 | 1.4 | 1.6 |
2010 | 1.6 | 1.3 | 1.0 | 0.6 | 0.1 | -0.4 | -0.9 | -1.2 | -1.4 | -1.5 | -1.5 | -1.5 |
2011 | -1.4 | -1.2 | -0.9 | -0.6 | -0.3 | -0.2 | -0.2 | -0.4 | -0.6 | -0.8 | -1.0 | -1.0 |
2012 | -0.9 | -0.6 | -0.5 | -0.3 | -0.2 | 0.0 | 0.1 | 0.4 | 0.5 | 0.6 | 0.2 | -0.3 |
2013 | -0.6 | -0.6 | -0.4 | -0.2 | -0.2 | -0.3 | -0.3 | -0.3 | -0.3 | -0.2 | -0.3 | -0.4 |
2014 | -0.6 | -0.7 |
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Curiously the ONI value for the first two three-month periods of this year are actually La Nina type values. I anticipate we will see a big change in the February March April value which should be updated really soon. Just for fun I counted the number of three-month periods since April/May/June 1998 when it appears the Pacific Decadal Oscillation changed phase from positive to negative where the ONI was +0.5 or higher (positive i.e. El Ninoish) or -0.5 or lower (negative i.e. La Ninaish) and if I counted correctly I have 75 negative values and 34 positive values. This 2:1 ratio is consistent with the sparcity of El Nino conditions and is consistent with PDO- conditions. Also the AMO has been in its positive phase during this entire period of time which also suggests a paucity of El Nino conditions. The above table provides a good way of understanding the pattern of El Nino and La Nina conditions which has prevailed slince the PDO changed phase.
It is useful to remember that there are two criteria for ENSO one of which is related to sea surface temperatures and the other part has to do with air pressure differentials.
One can see the reversal to El Nino Coniditions re the Southern Oscillation early this year. It seems that the correlation between the ONI and the SO is so consistent that generally people these days only really consider the ONI Index. But it pays to watch the change in atmospheric circulation which is significant in producing the wetness that results from El Nino in the Northern part of South America and the Southwest in the U.S.