I know everyone has heard the term “El Niño” going around. What exactly is that? El Niño is the term for unusually warm waters in the Equatorial Pacific Ocean. There is also the opposite of that called La Niña, which is the term for unusually cool waters in the Equatorial Pacific Ocean. I also know that people have been hearing the term “Super El Niño” recently and wonder what the difference is between an El Niño and a Super El Niño.
El Niño’s are classified into 4 categories: Weak, Moderate, Strong, Very Strong (Super El Niño)
- Weak El Niño’s have an average water temperature deviation of 0.5 °C to 0.9 °C.
- Moderate El Niño’s have an average water temperature deviation of 1.0 °C to 1.4 °C.
- Strong El Niño’s have an average water deviation of 1.5 °C to 2.0 °C
- A Very Strong El Niño has an average water deviation that exceeds 2.0 °C.
Since 1950, there have only been three El Niño events classified as “Super El Niño.” The first one was in 1981-1982, the second one being in 1997-1998 and the final one being 2015-2016.
The Jet Stream Impacts
El Niño events can directly and indirectly affect the weather here in the USA. We are also more likely to feel the impacts during our cooler months from basically October through May, so we will focus on those months. Before I explain what the impacts usually are, let’s take a quick lesson regarding the track that a storm system takes.
I know you all have heard of the “Jet Stream”, well there are actually two of them. The Polar Jet Stream and the Subtropical Jet Stream. Storm systems tend to follow the Subtropical Jet like a highway and El Niño events tend to shift and extend this highway towards the southern United States. In short, moisture from the Pacific Ocean and the Gulf of Mexico can be pulled along the Subtropical Jet Stream by any given storm system, leading the way for wetter than average conditions from Southern California through the Southeast.
The Polar Jet Stream tends to be further north than average, across the northern US and Canada. The Polar Jet Stream basically acts like a barrier and keeps much of the arctic air in the arctic. Subtle and random dips in the Polar Jet Stream will happen periodically but overall will happen less than an average year. That being said, the northern US is typically drier and warmer in winter than on average.
How Does it Relate to us?
I decided to do some digging and look back at these past three Super El Niño events and the winter before to see how they unfolded across in Southern West Virginia. The data that I got was based off the Beckley area weather station on the NWS Charleston WV page. These findings are specifically for that area, and these events may have behaved differently in other parts of West Virginia, given the complex terrain of The Mountain State. The findings were not what I quite expected to see as all three Super El Niño events were very different.
Now, let’s take a look at those past three El Niño events case by case!
1982-1983
The event in 1982-1983 was much drier than you would expect in a typical El Niño with only 3.65″ of liquid precipitation (rain/freezing rain/water content in snow) from December through February, however it still ended up producing 51.3″ of snowfall over those three months nearly 10″ above the average, but 6.8″ less than the previous winter. With ~51″ of snow measured with just over 3.5″ of liquid precipitation, that leads to a liquid-snow ratio of roughly 14:1 which is typically drier and fluffier snow than normal, which has a liquid-snow ratio of 10:1. The temperatures over these months were also slightly warmer than average with the average temperature in December being 41℉, which is 5.6℉ warmer than the average December temperature.
1997-1998
When we look at the El Niño of 1997-1998, it is much different than the 3.65″ in 1982-1983 with 11.96″ of liquid precipitation falling from December through February. The snow totals were also much more during this event with 76.2″ of snow falling in that three-month period, which is 35.1″ above the average snowfall across that period. The liquid to snow ratio of that snow was also much different than the previous case, just over 6:1. That makes the snow of 1997-1998 overall much heavier and wet. There is an exception to look at in this winter season though. The average January temperature of 1998 was 36.2℉, nearly 6℉ warmer than average. However, 29.2” of snow fell during that month which obliterates the average January snowfall of 16.9”.
When I looked closer at January of 1998, one thing stands out to me. 25.5” of that snow fell over 2 days in late January. From January 1st through January 26th, Beckley was running nearly a foot below average. The temperatures in early January were running 20℉ above average but had cooled down to below average for a couple days in a row, while a storm system happened to be traversing the Appalachians in late January.
2015-2016
Lastly, we are going to look briefly at the event of 2015-2016 and it’s also pretty different than the other two. The total liquid precipitation from December through February was 9.41″ which is right around the average of 9.44″. The snowfall was 39.2″ over that three-month period which is also right around average. The big difference in this one though, was that basically all of that snow fell in January and February, while December only measured a trace.
Conclusions
So, while we can’t really gather a true pattern through all this data on how a Super El Niño impacts southern West Virginia. We can point out the fact that early winter (November-December) tends to be drier than or right around average. Mid-winter (January) is an unpredictable battle ground where all it takes is one storm like 1998 to send the winter into the history books. February has averaged just under 25″ of snow, which is actually 11″ more than average since 1965.
What this means is that we won’t know exactly how this Super El Niño will behave. But Super El Niño’s in the past have brought warmer temperatures and more moisture in some months. While it still will get cold on some days (it’s the mountains for crying out loud), if moisture and those colder days line up, then we might see something like 1998. If the moisture and those colder days don’t line up, it’ll be closer to the other two, which had 3 of the 4 core winter months less snow than the previous winter.
