El Niño events are measured by looking at temperature levels in a vast rectangular zone in the central Pacific. In a moderate El Niño, temperatures might climb, say, 1 degree Celsius, or 1.8 degrees Fahrenheit, above a longer-term average. But in the biggest El Niños of the past 50 years — the ones that started in 1982, 1997, and 2015 — temperatures have soared 2 degrees Celsius or more beyond the norm. Each of those events levied a global economic toll.
It does appear that El Niño is coming, perhaps a big one. But the climatebrink site is not consistent with the two places I go for El Niño forecasts: NOAA and IRI, a research institute at Columbia.
Climatebrink says the median forecast is 3.1C.
Here’s NOAA. They say we will almost certainly have an El Niño, with a 37% chance of warming greater than 2C. That rules out a median of 3.1C
I’ve long heard about more California winter rain in El Nino years, and yet looking at a precip chart one can’t pick out strong El Ninos such as 1982-83, 1997-98 and 2015-16. 1998 seems to be the main example.
Interesting. With your prompting I spent a few minutes with Claude and asked it to make a scatterplot of ENSO temperatures and precipitation. There’s a modest correlation with some outliers.
Claude says a 1986 paper established the connection between ENSO and CA rainfall that has entered my consciousness. It says recent papers call that strong connection into question, saying the Pacific Decadal Oscillation also matters, there are regional differences within California, and perhaps ENSO makes storms wetter but doesn’t cause more of them.
