El Nino climate pattern officially ends as flip to hurricane-fueling La Nina looms

El Niño conditions are considered to be active when sea-surface temperature anomalies reach 0.5 degrees Celsius (0.9 degrees Fahrenheit) above average in critical parts of the eastern and central Pacific.

The strong El Niño pattern that had a significant influence on major weather pattern shifts over the past year, including sending relentless storms across California and the South while leaving much of the North with a well-below average snow season during the winter, has come to an end, NOAA announced in its monthly update Thursday.

And looming on the horizon: A flip to the opposite La Niña pattern, which could enhance the 2024 Atlantic hurricane season.

An El Niño is considered to be active when sea-surface temperature anomalies are at least 0.5 degrees Celsius (0.9 degrees Fahrenheit) above average in critical parts of the eastern and central Pacific.

When neither La Niña nor El Niño are in control of what's known as the El Niño Southern Oscillation (ENSO) pattern, it is considered to be a neutral status, which is sometimes referred to as La Nada.


Weather impacts from a neutral event

The exit out of an El Niño into a neutral status will likely not mean any immediate weather changes for North America, but the FOX Forecast Center will be watching for impacts during the upcoming summer and hurricane season.

Meteorological summer began on June 1, the same date as the start of the year’s tropical cyclone season.

Neutral years have run the gamut from just a handful of tropical systems to being one of the most active on record, but seasons under a neutral regime typically are more impactful than those that occur during an El Niño.

On the temperature front, all occurrences of neutral events over the last two decades have produced summers that had above average or well-above average temperatures.

The neutral-ENSO summer of 2019 was the hottest season on record for North America, with record heat experienced along both the West and East coasts.


La Niña up next after the neutral phase?

The world sits at a complex crossroads for what could be next for the central and eastern Pacific.  While most climate models indicate the arrival of a La Niña, the time frame remains a bit murky.

NOAA believes there is a greater than 60% chance of returning to a La Niña state by late summer, but some forecasters believe it could be later in the year before water temperatures cool to greater than -0.5 degrees Celsius below normal.

However, experts at Colorado State University and many others consider the impending La Niña to play a significant role in intensifying the 2024 hurricane season.

Researchers said they expect 23 named storms to form in 2024, with 11 that could reach hurricane status. Five of the 11 hurricanes are expected to reach major hurricane status with winds of at least 115 mph.

As we exit hurricane season at the end of the year and march toward fall and winter, the La Niña phase typically correlates to dry weather in the southern U.S. and cooler, wetter weather in the Pacific Northwest and parts of the North. 

It would be the opposite of what we’ve generally seen this past El Niño winter.

California took the brunt of several storms – many of them atmospheric river storms – leaving much of the state well above average for precipitation.

As the strong Pacific jet stream persistently hugged the South, several rainstorms have pushed through Texas and the Gulf Coast. Florida suffered through one of its cloudiest December-January periods on record, according to data from Alaska climatologist Brian Brettschneider.

Meanwhile, aside from a strong polar-vortex-fed arctic outbreak in mid-January, it was a very mild winter across the nation's northern tier. 

Minneapolis had just 29.5 inches of snow – nearly 22 inches below average – and people were able to play golf and install swimming pools during the winter in a region more well-known for subzero temperatures and snowstorms.  Swimming and golf may be relegated back to more of a summertime event if La Nina gets a hold of next winter.