How a switch to El Niño could affect hurricane season
AUSTIN (KXAN) — As you may have heard by now, La Niña has met its end and we're currently in the Neutral phase of the climate pattern El-Niño-Southern Oscillation (ENSO).
While we're expected to stay neutral through at least spring and possibly a good chunk of summer, a switch to El Niño is expected from late summer into fall.
Now, Atlantic Hurricane season begins June 1 and lasts all the way through Nov. 30. This means it's likely that a good chunk of Atlantic Hurricane Season 2023 will be spent in an El Niño pattern.
El Niño and hurricanes
El Niño is the warm phase of ENSO, where the waters of the eastern Pacific are warmer than normal. Less vertical wind shear in the hurricane development zone west of Mexico typically brings more frequent hurricanes to the eastern Pacific basin.
However, in the Atlantic, El Niño typically lead to fewer hurricanes. This is largely due to increased vertical wind shear and more stability in the atmosphere. Wind shear is not good for the development or the sustaining of hurricanes as it rips them apart and a more stable atmosphere prevents the lift required for these storms.
What other factors impact hurricane season
While we talk about the changes in ENSO phase over the course of a few years at the most, there are other longer period climate phases that impact hurricane season and take much longer to switch.
The Atlantic Multi-Decadal Oscillation (AMO) can take decades to flip between cold phases and warm phases. Warm phases or "eras" lead to increased hurricane activity due to warmer waters, weaker trade winds and less vertical shear. While this doesn't impact the entire tropical Atlantic Ocean, the warm phase of the AMO can offset some of the mitigating circumstances caused by El Niño.
According to Climate.gov the warm phase of AMO during an El Niño hurricane season averages out to bring a near-normal Atlantic Hurricane Season. We've been in a warm phase of AMO since 1995.
We'll start getting 2023 Atlantic hurricane season forecasts from Colorado State University in early April. The National Hurricane Center typically releases their first hurricane season forecast later in May.
Stay with the First Warning Weather Team as we track any impactful tropical weather through the year.