Mark Twain once said – “everyone talks about the weather, but no one does anything about it”.  That has been the case for the Florida panhandle now.  We have been in a drought and water levels are lower.  Our total rainfall for the Pensacola area in 2025 was 60.68”.  This is in line with our historic annual mean of 60-61 inches a year.  So far – for the winter of 2026 – we are at 7.81”.  Over the last three months this would be 2.60” / month, which could suggest an annual rainfall of 31.24” for the year.  But you must remember that the winter months are the dry season for us, and we expect more rain during the wet season – spring and summer.

 

But it has been mentioned that 2026 will be an El Nino year.  Most of us have heard of the El Nino, but what is this? And how will it affect our rainfall?

I first learned of the El Nino in the early 1980s when I was working at Dauphin Island Sea Lab.  The name came from Peruvian fishermen who had been witnessing this event for a long time.  Off the coast of Peru there is a cold water ocean current known as the Humbolt Current.  This current comes from Antarctica and moves towards the equator, passing Peru along the way.  Peru is a mountainous country.  Cold, dry winds from the higher elevations flow down the mountains and offshore across the Pacific Ocean.  As this wind blows offshore it moves the surface of the ocean offshore as well.  This offshore movement causes a current to move from the seafloor to the surface – what oceanographers call an upwelling.  These upwellings bring nutrients from the seafloor to the highly oxygenated, sun lit waters at the surface – and the amount of marine life explodes.  The fishing grounds off Peru are some of the richest in the world.  We see a similar system along other coasts where the ocean currents are cold and mountains are found along the coastline – California for one.  But for centuries, the Peruvian fishermen have noticed that every so many years this upwelling appears to stop, the nutrients cease, and fishing is not good.  This event would usually occur near Christmas and so they called it the “El Nino” – the child.

 

In the early 1980s science was still not sure what caused this.  They noticed a pattern, about every 10 years, but were not sure what occurred to trigger it.  They did notice there was a pattern of increased sunspot activity on the sun during El Nino years but did not know if there was a cause and effect, or whether it was just coincidence.  However, scientists from other parts of the Pacific were noticing other events besides the decrease in fish off Peru.  Further north off the coast of Panama corals would experience a large die off.  Further north still off the coast of California there were large die-offs of young seal pups.  This El Nino seemed to be more of a global phenomenon.  Further monitoring found that the cold ocean currents became warm during the El Nino years.  But what caused this.

 

The International Decade of Ocean Exploration occurred in the 1970s.  More than 50 countries from around the world worked to better understand the oceans.  One of the questions on the agenda – could we predict when El Nino’s would occur.  In the 1990s science understanding of the El Nino was as such…

1. Occurs every 3-7 years.
2. Wind patterns and rainfall distributions shift.
3. Satellite observations and sea-level measurements from central Pacific Islands can detect, and predict, El Nino’s 9 months before they begin to affect the South American coast.
4. The Pacific Ocean currents near equatorial South America move warm water across the ocean to Indonesia, where it “builds up” and forms an area of very warm seawater.
5. This “pocket” of warm ocean water in the western Pacific somehow causes the prevailing trade winds (which normally flows from the eastern Pacific to the western coast) to reverse. The cause of this in the 1990s was not understood.  This reversal lasts from a few days to a few weeks and usually occurs between November and April.
6. These reversals are sometimes accompanied by strong typhoons north and south of the equator, which make landfall in the western Pacific.
7. As this pocket of warm water expands in the western Pacific, the high pressure zone over the eastern Pacific (caused by the cold ocean current there) weakens, as does the low pressure zone over the western Pacific. The atmospheric circulation over the entire Pacific changes and warm water begins to move back towards the eastern Pacific.  This is referred to as the Southern Oscillation.  The Southern Oscillation and El Nino event was given the acronym ENSO.
8. Typhoons occurring in the western Pacific generate waves of warm water flowing back towards the eastern Pacific and generally encounter the Peruvian coast 9 months after the atmosphere in the western Pacific began moving them.
9. The effects of this movement – the El Nino – usually last one to two years. During this time the pocket of warm water in the western Pacific has been depleted and there is no more to “push” across the ocean.  Things return to normal.
10. Warm water begins to build up in the western Pacific again, and the cycle begins again. What the Peruvian fishermen have witnessed for decades but had no explanation of.
11. In the 1990s oceanographers did witness an increase in the frequency of El Ninos – which could be connected to climate change.

Oceanographers noticed the effects of an El Nino were more worldwide.

1. The normal dry central Pacific Islands flood due to increased rain events from warm water moving back in their direction.
2. There are fewer hurricanes in the Atlantic. This can trigger droughts in areas expecting hurricane rains.
3. During the strong El Nino of 1982-83, droughts and wildfires were catastrophic in Australia.
4. Heavy rains and flooding caused much damage to the drier regions of South America.
5. The El Nino of 1991 lasted until 1993 (unusually long), and it reoccurred in 1994-95 (unusual). These brought severe storms to California.
6. At times, at the end of an El Nino and as things get back to “normal”, it can “overshoot” and the waters off of Peru become colder than normal. This can cause a shift in the jet stream and additional climate/weather changes.

It was not quite understood then, but oceanographers did believe that human induced climate change was affecting the ENSOs.

 

What have we observed since…

 

1998 – El Nino

1999-2000 – La Nina (when the Pacific is colder than normal, that’s another story)

2001-2002 – Neutral/Normal years

2003 – El Nino

2004-2006 – Normal

2007 – El Nino

2008 – La Nina

2009 – Normal

2010 – El Nino

2011-2012 – La Nina

2013-2015 – Normal

2016 – El Nino

2017-2020 – Normal

2021-2022 – La Nina

2023-2024 – El Nino

2025 – La Nina

 

So, what lies in store of 2026?

 

NOAA posted this on March 12, 2026…

A transition from a La Nina to climate neutral (normal) conditions is expected over the next month.  This should last until June-July when there is a 62% chance the El Nino will begin to form and extend through the rest of 2026. 

 

If this does happen, we can expect fewer tropical systems in our region of the Atlantic this year.  The impact (strength) may dictate the movement of the jet stream and how much rainfall we can expect.  It could be drier.  The west coast could be wetter.

 

Oceanography is cool.

 

References

 

Gross, M.G., Gross, E. 1996. Oceanography; A View of Earth. Prentice Hall. Upper Saddle River, New Jersey. 7^th edition. pp.472.

 

NOAA. Past Events. psl.noaa.gov/enso/past_events.html.

 

NOAA.  National Weather Service. Climate Prediction Center. Climate Prediction Center: ENSO Diagnostic Discussion.

 

Accuweather. El Nino 2026. El Nino is brewing: Here’s what it means for US weather in 2026.