History repeats in weather
October 2, 2023
What is an analog year? Years in the past with weather patterns similar to the current weather pattern and those projected by the weather models for the next several months. Basically, using history to help forecast the future…
I always like to share with you some analog years for the next several months, and this year we have strong El Niño to work with. The other thing about this fall and winter, is that we have a strong El Niño with a negative/cold Pacific Decadal Oscillation. That is somewhat rare… Since 1950, we’ve only had two years with a strong El Niño and a negative/cold PDO…1951-52 and 1972-73. The two maps below show the precipitation and temperature anomalies averaged out for those two years, from October through March.
The interesting thing about the precipitation anomaly map (first image), is that it does show some dry anomalies across parts of Texas. Typically, El Niño will bring wetter than average conditions to Texas and the Gulf Coast. The temperature anomaly map (second image) reflects the cold in the west and the warmth in the east during these two events. Not too out of whack, but historically, the cooler than average weather ends up in the South and the warmer than average weather in the North. The following map shows all the El Niño years since 1950 and their precipitation and temperature anomalies averaged out, from October through March.
Those maps are a little more in line with what we would expect El Niño to produce. Wettest in the southern half of the country, drier to the north. Certainly warmer than average across the north, with average to cooler than average south.
So, is there a perfect analog for the upcoming fall and winter? No… However, history would suggest than the southern tier of the country would be wetter and cooler than average. A lot of computer model information supports this too… However, I am always leary of the blanket statement associated with El Niño or La Niña. Every event is different and can may times have unexpected impacts. We still have some time to watch this evolve, but just wanted to show you some history and what is “expected”…