It’s official: El Niño has returned!
In a diagnostic discussion issued by the Climate Prediction Center on Thursday, forecasters say that El Niño conditions are present and are expected to strengthen into the winter months in the Northern Hemisphere.
First off, What is El Niño?
In order to understand El Niño (and La Niña, for that matter), we first need to touch on the El Niño-Southern Oscillation (ENSO).
ENSO is the climate pattern involving changing sea-surface temperatures in the central and eastern Pacific Ocean. Warming and cooling cycles of ENSO affect weather patterns across the United States, and also impact rainfall distribution in the tropics.
- El Niño: The warming cycle of the central and eastern Pacific Ocean waters. Winds at the surface, which typically blow from east to west, weaken and can even start blowing in the opposite direction. This allows ocean waters to warm, leading to El Niño conditions.
- La Niña: The cooling cycle of the central and eastern Pacific Ocean waters. Opposite of El Niño, surface winds strengthen, and shift the warm surface water farther west at a stronger rate. To replace that warm water, cold water from below then rises to the surface, creating cooler sea-surface temperatures which lead to La Niña conditions.
- Neutral: Neither El Niño or La Niña conditions. Sea-surface temperatures in an ENSO-Neutral cycle are close to average.
The return of El Niño this year
Forecasters say that weak El Niño conditions appeared earlier this spring as sea-surface temperatures started to warm in the Pacific Ocean. Since then, these temperatures have stayed in the warmer-than-average range, and atmospheric convection has enhanced over the equator in this region as well. Scientists say that this ocean-atmosphere relationship proves the emergence of El Niño conditions.
Going forward, El Niño conditions are expected to continue, and even strengthen, into the 2023-2024 winter months in the Northern Hemisphere.
An El Niño Advisory has been issued, meaning just that: El Niño conditions have been observed and are expected to continue.
How does El Niño impact our weather patterns in South Central Texas?
El Niño conditions typically mean cooler and wetter conditions for Texas winters, since the Pacific jet stream is positioned farther south. This then allows for more frequent weather systems to work their way into our area.
This could be good news as we continue to chip away at the drought, but we also may need to watch out for flash flooding down the road. We’ll keep you posted!