It’s been a while since we have talked about El Niño or La Niña. At last check we were under a weak La Niña. What that normally means is that for us here in the Southeast, we typically see drier and warmer conditions than normal. While this is the average pattern we see, it’s not definitive.
We did not see a lot of rain at the back end of the summer and went 40 plus days where we didn’t see measurable rain, but when it finally did start raining, it felt like it didn’t stop. Now was that due to a weakening La Niña? That is too hard to say, but ultimately that pattern is gone.
La Niña Explained.
La Niña occurs when the waters in the Pacific between South America & Australia become cooler than normal. This might seem weird that something so far away can influence our weather, but more often than not, it does. However, with the latest La Nina it is hard to break down the effects because of how weak it was. Even though we were in La Nina, it was close to neutral to most of the time.
La Niña effects are usually more noticeable during the winter time, but here in the Southeast and along the Gulf Coast, La Nina may also contribute to Hurricane climatology. During a La Niña, conditions usually mean more likely conditions for tropical development. This is because a La Niña typically sends the jet streams farther north and keeps the tropical jet farther south. This means, not as much wind shear, and that can spell more likely conditions for tropical development. Also, since on average the Southeast is warmer than normal, warmer Gulf waters might also be a factor, but again, this is very hard to measure, and just because conditions might be more likely, it can’t be said for sure it will mean more tropical cyclones (tropical storm/hurricane). Warm waters and low shear are just a couple pieces of a complex tropical cyclone puzzle.
Ok, now that we have a basis let’s talk about our forecast going forward. For the short term it looks like things will be neutral, but long term forecasts are calling for a potential El Niño to form by this summer. I do want to make mention at this time last year, forecasts were calling for a strong La Niña, but instead it turned out to be a weak La Niña, so while it is forecast for us to enter an El Niño later this year, we still can’t say 100% sure it will happen.
El Niño Explained.
El Niño occurs when the waters in the Pacific between South America & Australia become warmer than normal. This pattern results in a weakening in the westerly trade winds and as a direct result, the sub-tropical jet that influences weather patterns in the sub-tropics and northern tropics moves a little farther north. Typically this means for the Southeast we have a wetter and cooler pattern than normal as more moisture is able to move into our area due to the jet. Think of it like the jet stream, just a separate one that is normally farther south.
Like La Nina, El Niño may also influence our tropical season, but unlike La Niña, the effect of an El Niño may result in unfavorable development conditions for tropical cyclones and it is directly related to the sub-tropical jet. This jet is more apt to move over the Gulf of Mexico and the Gulf Stream and may mean increased wind shear, something detrimental to tropical development. However, like said earlier with La Niña, it gives a basis, but we can’t say for sure it will stop all tropical cyclones. There have been hurricanes and strong ones at that have occurred during an El Niño year. With hurricane season approaching though, anything that can hinder the chance for tropical weather is welcome.
So, that was a lot and like stated over and over again, both El Niño and La Niña do influence climate patterns, but they do not explain what can happen day by day and are not forecasts. So for the time being it looks like we will be neutral and maybe (key word maybe) by this summer we will begin to enter an El Niño. For more updates and details stay tuned to WKRG.com and be sure to follow the First Alert Storm Team on social media!