Believe it or not, 2023 hurricane forecasts actually showed up last month and a group out of England, Tropical Storm Risk, issued theirs on Dec. 9, calling for a “below-normal” hurricane season. TSR has been in the forecasting business since the early 1990s and most recently is headed up Dr. Adam Lea from University College London.
They base this on, as they admit, very preliminary data and conjecture, largely centered around La Nina and El Niño. We’ve had a La Nina pattern (cool Pacific waters) for the past three years and since 1950 that has only happened two other times, 1954-56 and 1998-2000. So it stands to reason to ask what kind of hurricane season followed those three-year stints? The answer is near or below-normal! In 1957, the storm count came in below as there were eight tropical storms, three hurricanes and two major -- although take note that activity in the Gulf was very busy and one of those majors was Hurricane Audrey which decimated Cameron, Louisiana (416 people died across the U.S. and Canada).
Following the La Nina years of 1998-2000, the 2001 season totaled 15 storms, nine hurricanes and four major (average is 14-seven-three). So while 2001 may have been near average, it was a bit above and included Tropical Storm Allison!
I find the comparison to past years a bit thin as a real predictor (there just isn’t enough data), but the waning La Nina and weak El Nino that is forecast probably holds some salt. You can see from this graphic the cool waters in the Pacific are in full force:
There is little probability we will continue with a La Nina for a fourth year and the models take us to a weak El Niño by late summer. I’ve highlighted the neutral line and you can see the ‘red’ forecast line goes above that by June:
Why is this important? El Niño trade winds across the Caribbean help tear up developing storms so a strong El Niño can inhibit storm development. Predicting just how strong the upcoming El Niño will be is not really possible (in scientific terms: lacks skill), but the models do indicate that La Nina is leaving.
Tropical Storm Risk last season’s early forecast was for 18-eight-three in 2022 and we wound up with 14-eight-two, so for hurricanes themselves they were right on target. This year’s early forecast for 2023 is 13-six-three against the average of 14 storms-seven hurricanes-three major.
You can have a look at the full (short) report from Tropical Storm Risk right here.
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