The Pacific Ocean is on fire. Well, not literally on fire, but it’s pretty damn toasty out there. Chris Farley would be proud of this El Nino. The large mass of unusually warm water in the equatorial Pacific continues to grow and become even warmer – possibly rivaling some of the strongest El Ninos in recent memory.
Computer model forecasts continue to show a strengthening of this El Nino – and most experts I’ve spoken to believe this El Nino will be strong come winter.
The question is – what will a strong El Nino mean for New England? The three most powerful winter El Ninos since 1950 have produced below average snow in Connecticut. In fact, the mean and median snowfall for the top 10 El Nino events is below normal for both Hartford and Bridgeport.
The record 1997-1998 El Nino was accompanied by a mighty dud of a winter. Only 8.9″ of snow fell in Bridgeport (average is 29.0″) and in the Hartford area only 28.7″ of snow fell* (average is 48.4″). The 1982-1983 El Nino which peaked over the winter was only somewhat below normal in terms of snowfall, 46.4″ in Hartford and 23.0″ in Bridgeport. Rounding out the top 3 the winter of 1991-1992 was another dud with 23.6″ of snow in Hartford and 16.5″ in Bridgeport. Awful.
The top 10 El Nino and top 10 La Nina events are all relatively blah when it comes to snowfall.
Top 10 La Nina Events (since 1950)
- Hartford mean snowfall 46.4″ / median snowfall 41.9″
- Bridgeport mean snowfall 26.3″ / median snowfall 22.6″
Top 10 El Nino Events (since 1950)
- Hartford mean snowfall 41.9″ / median snowfall 40.8″
- Bridgeport mean snowfall 26.0″ / median snowfall 21.5″
Also of interest is that the top 10 El Nino events in Hartford have an average winter temperature above normal. The top 10 events average a winter temperature of 29.5 degrees (median of 29.7 degrees) compared to the 30-year average of 29.1 degrees. Additionally the top 3 El Nino events (’82, ’91, ’97) were all well above average with a mean of 31.5 degrees – more than 2 degrees above normal.
El Nino is only one part of the puzzle. While odds favor a warmer than normal and less-snowy than normal winter in Connecticut meteorologists will likely have their hands full. A strong El Nino will essentially put the subtropical jet stream on steroids. Plenty of moisture and energy will be around for “fun” storms – likely many messy storms with snow, mix, rain, etc. Even a “below normal” winter can produce a big one – remember the Megalopolitan snowstorm of 1983?
*Notes: To compensate for missing snowfall data in the official records I’ve used our weather observer in Collinsville for snow totals and adjusted them by a factor of 0.86 (I got this from comparing the mean snowfall at BDL and Collinsville for available years). This isn’t perfect but it is the best we’ve got. Also, to compute the top 10 El Nino/La Nina I averaged the MEI over December, January and February to come up with a winter ENSO strength. All stats are for ENSO events 1950-present.