Yesterday, NOAA released this image of sea surface temperature anomalies over the Eastern Equatorial Pacific comparing current conditions (on the right) to those of the strongest El Nino that has been observed in the last 30 years (November 1997 on left).
A Bruce Lee El Nino?
While the current El Nino is drawing comparisons to the famous 1997-1998 event, one NOAA writer is comparing it to the late, great Hollywood Action Star, Bruce Lee...
Tropical storms and hurricanes have been given names since the early 1950s, which helps to clarify communications. In recent years, the Weather Channel has attracted attention by naming winter storms, perhaps with similar intentions. “So why don’t we name ENSO events?” you ask. Excellent question! I propose we do name them, starting this year. Since I think we should have a theme to the names, and the theme should be action movie stars, I hereby designate the 2015-2016 event as El Niño Bruce Lee.
Statue of the movie star and Chinese martial artist Bruce Lee on the Avenue of Stars of Hong Kong. Photo by Soerfm from Wikimedia.org.
In all seriousness though, the current El Nino is strong and sea surface temperatures have risen to their highest level in nearly 20 years off the coast of Ecuador.
So what does this mean for late Summer and early Fall?
The Climate Prediction Center, which heavily biases it's seasonal forecasts on strong ENSO (El Nino - Southern Oscillation) events, recently updated their August - October predictions indicating that wetter than normal conditions will likely continue in our area and for much of the West-Central US.
Temperature-wise, the expectation is for slightly cooler than normal conditions through the period.
How long could this El Nino last?
Current climate models are in good agreement that the current El Nino event will continue and possibly strengthen through the fall months and will likely still be going strong by the start of winter.
How will El Nino impact our winter?
Strong El Nino events tend to have a strong influence on the weather over the US during the winter months.
In the plots below, are odds of a wetter/drier and warmer/cooler than normal January thru March time frame (Winter/Early Spring) based on 100 years worth of data collected between 1896 and 1995.
The plots show the odds of a wet/dry or warm/cold season with ENSO conditions preceding the season. ENSO conditions are defined from the SOI index. The lead time is 3 seasons to concurrent. Results are based on the US climate division dasaset for 1896-1995. Extreme is defined as being in the highest or lowest 20% of the 100 year record. ENSO is defined as the top 20 SOI years (La Niña) and the lowest 20 SOI years (El Niño). Four extreme events would be expected by chance. A decrease number of years to zero or one year would be significant at the 99.3% and 95.7% level, respectively. An increase to seven, eight or nine years would be significant at the 95.4%, 98.6% and 99.9% levels. Actual significance is probably less due to the number of tests run and time/space correlations in the dataset.
So what does this mean?
The above information indicates that we will likely have a drier than normal winter this year and temps could be below normal again.
While strong ENSO events do carry weight going into a winter forecast, ultimately it is not the only climate signal that influences our weather and at the end of the day we will have to wait and see how these other indicators come together before making a true assessment of our 2015-2016 winter season.
It is worth noting, however, that the last time we had an El Nino as strong as this one, we ended up with a HUGE February snow when Louisville picked up a record 22" snowfall on February 3 - 6, 1998.
While I'm certainly not calling for anything like that this season, it will be something to watch for.
WDRB Meteorologist Jeremy Kappell
Find me on Facebook!
Follow me on Twitter!
Email me at email@example.com