El Nino is really ramping up right now.

 

It’s been a while since I talked about El Nino and other teleconnections.  So, I wanted to talk about it again. As it will be a bid deal going forward.

This post is very long and will go into El Nino and how it’s evolving, it will also the historical impacts of El Nino based on overall strength. I will try to draw some conclusions on that this could mean for winter 2026-2027.

What is El Nino?

I’ve posted many times what El Nino is and what defines a weak El Nino from a very strong one.

But here is a quick refresher.

The El Nino-Southern Oscillation, or ENSO is a recurring Pacific climate pattern that shifts ocean temperatures and disrupts tropical wind and ocean currents, weather patterns, and temperatures across the globe. The ENSO consist of El Nino, Neutral, and La Nina.

One way the ENSO phase is diagnosed is by using observations of sea surface temperatures in different regions of the equatorial Pacific Ocean. Sea surface temperature (SST) departure from average in the Nino 3.4 region.

El Nino is the warm phase of the ENSO. During an El Nino, western trade winds weaken in the Pacific Ocean, this allows warm surface water to move west across the equatorial Pacific towards South America. This allows the central and eastern tropical Pacific Ocean to become warmer than average.  That increased warmth can alter atmospheric circulation and impact the position of the jet stream across North America.

The ENSO is considered neutral when the Nino-3.4 index is +0.4°C to – 0.4°C

An El Nino is very Strong if the Nino-3.4 index is over +2.0°C (nicknamed a "super" El Nino).

Strong is when the Nino-3.4 index is at least 1.5°C

Moderate is when the Nino-3.4 index is at least +1.0°C

And weak is when the Nino-3.4 index is at least +0.5°C

What’s happening now with the El Nino

The 2026 El Niño has moved beyond the “developing” stage. The Pacific Ocean and atmosphere are now strongly coupled, and the latest multi-model forecasts show a rapidly intensifying event that could rank among the strongest since modern records began

As of 20 July 2026, the equatorial Pacific is warming: the weekly Nino-3.4 index stands at +2.1 °C which is in El Nino territory, while the official three-month ONI for Apr–Jun 2026 is +0.98 °C, which is showing a moderate El Nino. For this reason, NOAA’s Climate Prediction Center has us in a El Nino Advisory in effect. NOAA Issues this when El Nino or La Nina conditions are observed and expected to continue. NOAA is giving El Nino a 97–99% chance of persisting and strengthening through the upcoming winter, with a roughly 60% chance it reaches “strong” territory in Nino-3.4.

Images from the latest NOAA El Nino discussion

Another factor to think about.

 

Atlantic Nino

The Atlantic has something that is very similar to El Nino. This is called the Atlantic Nino and is characterized by warmer-than-average sea surface temperatures (SST) in the eastern equatorial basin and weaker-than-average trade winds throughout the east-central equatorial Atlantic. The opposite is an Atlantic Nina and is characterized by cooler-than-average sea surface temperatures (SST) in the eastern equatorial basin. Like the ENSO the Atlantic Nino/Nina swings between warm and cool phases every few years. In most years the temperature profile between El Nino/La Nina is similar.  Atlantic Nino/Nina, where the two can be in the same warm phase, or they can have opposite phases. The Atlantic Nino/Nina tends to be overall much weaker than ENSO and has less impact on the Climate.

Strong summer Atlantic Nino events are much more common than strong summer Atlantic Nina events are uncommon.  Those tropical Atlantic SST are running around 1°C to 3°C below average across the Atlantic Nina area. So, this is considered a strong event.

This summer we’re seeing a very rare cooling event in the tropical Atlantic This has emerged just as El Nino continues to strengthen in the Pacific.

The same report said current with the cooling linked to strengthened trade-wind-driven upwelling. Forecast output cited by Severe Weather Europe shows the cool Atlantic anomaly lasting into late August, while Pacific El Niño anomalies continue to intensify.

Satellite shows that cold pool in the Atlantic, while it also shows that very warm El Nino anomaly continues building across the Pacific.

El Nino’s warmer-than-average waters in the Pacific can cause more sinking air over the Atlantic and increase wind shear, which can lower Atlantic tropical activity. At the same time, a cooler tropical Atlantic associated with Atlantic Ninna can reduce the amount of heat and moisture available to fuel thunderstorms in one of the key regions where hurricanes develop. With the El Nino in the Pacific and the Nina in the Atlantic, could help farther suppress Atlantic hurricane development this season. This could make the 2026 Atlantic hurricane season, even quieter than we would expect even during a strong El Nino.  But a quiet season doesn’t mean there can’t be tropical impacts. 1992’s Hurricane Andrew is evidence of that.

If the Atlantic Nino persist into Winter 2026–27; it will pair with a possible strong El Nino. This could increase the risk for more frequent and intense winter storms, with a mix of snow, ice, and rain depending on the timing of different air masses.  If this persists it could Increase the chance for more a stormy, wet winter in the Northeast and mid-Atlantic then we would expect to see during El Nino. There is a chance it could extend the length of the Northeast winter season into early spring.

 Rest of Summer into this Fall.

The Northeast and northern Middle Atlantic region has already been seeing the impacts of the developing El Nino.  We’ve seen an up and down pattern, but June and July has seen a few hot and very humid stretches.  an increase in severe storms, that has resulted in quite a bit of flooding.  

This kind of pattern is typical during a developing El Nino.

With the El Nino continuing to strengthen, it will have even more impact during the end of Summer and Fall.  So, the region will experience more bouts of above-average warmth and humidity. which can sometimes contribute to increased precipitation across the Northeast. I expect to see the increased risk of frequent thunderstorms, due to the parade of frontal systems to continue.  This should allow the northeast and Middle Atlantic region is see overall above average temperatures and average to above average precipitation through the Fall.  With the chance for heavy rain at times, Possible flooding will be a concern. With the setup, the Northeast and Middle Atlantic are going to continue to see severe weather outbreaks, as all this evolves.   

 

What about Winter?

The Arctic ice melt season is underway, and right now, sea ice extent over the Bering Strait and Arctic Ocean is slightly lower than it was at this time last year.  How much sea ice remains at the end of the melt season remains to be seen.  The amount of ice will have an impact on winter 2026-2027. We will have to wait until October to find out how the ice looks and how the snowpack builds in Siberia for the answer.  

 

 Winter impacts for this El Nino

How will the ENSO impact our weather patterns across North America and specifically here in the Northeast this upcoming winter? I will touch on the general winter outcome during a strong El Nino.

The jet stream is one of the biggest drivers of weather during the winter when it drives major winter storm development.

Even with El Nino, the colder air will return to North America, that temperature contrast is going to lead to a screaming subtropical jet. During El Nino we also usually see the northern Polar jet stream shoved well north into Canada. This helps lock out that cold over northern Canada. The setup normally has the Pacific storm track shift south. Which leads to increased precipitation across California and the southern US into the Southeast. At the same time the Northern half of the United States is prone to seeing warmer and dry conditions.

 El Nino’s Likely Impact on the Northeast and northern Mid-Atlantic this Winter

This El Nino is expected to peak in late fall and early winter, making it one of the strongest on record since 1950. The strongest El Nino’s on record were 1877–1878, 1982–1983, 1997–1998, 2015–2016. The El Nino of 1877–1878: Considered the strongest El Nino ever recorded, while this currently El Nino is expected to be very strong, there is still some uncertainly on that. But many climate models are showing the 2026-2027 being at least as strong as the 1877–1878 if not stronger.

 Looking at the strongest El Nino’s over the last 44 years. We come up with 1982–1983, 1997–1998, 2015–2016. While no two El Nino’s are the same, we can draw some general conclusions by looking at temperature and precipitation anomalies from those years.

 

Temperature trends

During El Nino winters, the jet stream configuration typically brings warmer, drier air from the Pacific into the Great Lakes and Northeast. This often results the Northeast generally experiencing warmer-than-usual conditions. However, precipitation patterns are much more unpredictable. Here’s an imaging showing the typical El Nino pattern over North America.

 

Regional differences

 

Coastal New England: Warmer temperatures, more variable snow, and possible and wetter conditions in some years.

Atlantic coast: Warmer air masses from the Gulf Stream can keep coastal areas milder and wetter in some winters.

Interior and higher elevations: May see more snow than coastal areas, but still likely less than normal for a strong El Nino year.

On average, the stronger the El Nino episode, the warmer and wetter the winters have been

What does a stronger El Nino typically mean for snowfall? The map below from NOAA shows how far above and below average snowfall has been during a typical strong El Niño January through March period.

You can see quite a split in the Northeast. While much of the interior Northeast from western Pennsylvania to parts of New England trend less snowy, parts of the mid-Atlantic from southern New Jersey to Virginia and the southern Appalachians have tended to be much snowier in a stronger El Niño winter.

Snowfall departures from average during moderate to strong El Nino January-March periods. Areas in brown typically have seen less snow, while those in blue have seen more snow.

But it's not just the strength of the El Nino. El Nino isn't the only factor influencing the winter weather pattern. Other ingredients could throw a monkey wrench into this snowfall scenario.

One of the main reasons for this verbality has to do with high latitude blocking (Greenland Blocking). This typically occurs during a negative NAO.

When high pressure aloft forms near Greenland, it blocks the west-to-east flow of the jet stream, forcing it to take a sharp southward plunge into the eastern U.S. This pattern delivers ample cold air from Canada and sometimes is an instigator for East Coast snowstorms.

How often this pattern develops in any winter season is challenging to figure out months ahead of time. But if it sets up frequently during a stronger El Nino winter, parts of the Northeast can have a colder, snowier winter.

The area of blocking high pressure near Greenland forces a southward plunge in the jet stream across the eastern states when the North Atlantic Oscillation is in its negative phase. This leads to persistent cold temperatures and the potential for East Coast snowstorms.

Even a stronger El Nino doesn't necessarily guarantee strong impacts on the weather pattern.

Here’s what the data shows. We examined seasonal snowfall totals during nine strong El Ninos since 1950 for several Northeast cities.

When we break down nine seasons into those which also had frequent Greenland blocking (three seasons) and those that had a lack of blocking (six seasons). Admittedly, it's a rather small sample size. There where big differences.

For the Middle Atlantic Region

Both Philadelphia and Washington, D.C., saw generally more snow on average in a strong El Nino winter.

These composites are further broken down by the strength (weak, moderate and strong) of the El Nino episode. Based on the small dataset, there is some historical correlation between the strength of the warming in the equatorial Pacific Ocean and seasonal temperatures, precipitation, and snowfall locally at Washington D.C. and Baltimore. Weak El Nino winters averaged below normal temperatures and precipitation, while strong El Nino episodes averaged above normal temperatures and precipitation. These findings can partly be linked to a stronger than average sub-tropical jet that typically occurs during moderate to strong El Nino winters, which would favor more active storm systems moving northward from the south that draw warm, moist air northward as opposed to the drier Alberta clippers from the northwest. Seasonal snowfall averaged above normal, especially for moderate El Nino episodes.

Not all El Nino winters are alike as many other shorter [e.g., North Atlantic Oscillation (NAO), Pacific-North American Pattern (PNA)] and longer-term climate patterns influence the local weather. For example, the moderate El Nino episode during the 2009-10 winter was associated with record-breaking seasonal snowfall in the mid-Atlantic region. Although it might seem (based on the 2009-10 winter) that all moderate El Nino winters in Washington D.C. and Baltimore are linked to above normal snowfall, these atmospheric quantities have been variable each winter. Of the seven strong El Nino winters since 1950, four have been associated with well above normal snowfall while snowfall was virtually absent in the other three winters.  

I​-95 Contrasts

Snowfall was generally less during a strong El Nino winter from New York City northward. Boston saw an average reduction of almost 25% in snowfall during a strong El Nino. It is typically a different story in the mid-Atlantic states. Both Philadelphia and Washington, D.C., saw markedly more snow on average in a strong El Niño winter.

Strong El Nino winters with frequent Greenland blocking (labeled as -NAO in the graph below) were much snowier than average in New York City, Philadelphia and Washington, D.C. But, as alluded to earlier, there were only three such winters since 1950. By contrast, strong El Ninos without much Greenland blocking were far less snowy than average along the I-95 corridor.

Seasonal snowfall during all strong El Ninos (yellow bars), strong El Ninos without Greenland blocking (red bars), strong El Ninos with frequent Greenland blocking (blue bars), compared to 1950-2023 average (gray bars) in four major Northeast cities along the Interstate 95 corridor.

Interior Northeast

 

Over the rest of the Northeast, there was generally less snowfall during stronger El Ninos in most areas, consistent with the map we showed earlier. Most of these areas were saw similar ups and downs in snowfall due to strong El Nino winters with frequent/little Greenland blocking, respectively. So strong El Nino with little Greenland blocking saw lower snowfall amounts. The notable exception was in northern Maine. While each strong El Nino exhibited an average reduction in snowfall of around 10% in Caribou, Maine, the amount of Greenland blocking didn't make much difference there. (I’m not really sure why)

Same as the previous graph, but for interior Northeast cities from Pennsylvania to Maine.

Will this winter be a repeat of 1997-1998.

The super El Nino brought unusually warm temperatures and below-normal snowfall across much of the Northeast, with notable exceptions in the form of extreme ice storms

The winter of 1997-1998 in New England and northern New York State was marked by extreme ice storms and heavy snow at times, with the January 1998 ice storm being the most catastrophic event. That ice storm was a series of five successive ice storms hit northern New York, Vermont, New Hampshire, and Maine from Jan 5–9, 1998, Ice accumulations reached up to 4 inches in some areas of northern NY and SE Canada, with 3/4–2 inches in northern New England. The winter of 1997–1998 in Pennsylvania was dominated by that strong El Nino event, which brought unusually warm temperatures and below-normal snowfall across much of the state. The Appalachians was a notable exception as they saw above to well above average snowfall.

During the winter of 1997-1998 the Coastal Plain and the I-95 saw very little snow.

Across the northern Great Lakes, the 1997–98 El Nino’s, it was a very mild and dry winter, with record-low ice cover and above-average lake temperatures, reduced lake effect snow totals compared to normal years, making it a winter with unusually weak LES for the area.

The 1997–98 saw the lowest Great Lakes ice cover over the lakes since systematic records began in 1960.

The snowbelt regions downwind of Lake Erie and Lake Ontario, likely will be cold enough at times to get lake effect snowstorms, Past winters that featured a strong El Nino saw average to slightly below average snowfall. But do the variable temperature pattern it was hard to keep much of a snowpack. Winter 2026-2027 could see a similar problem. But while the first part of the winter was extremely snow free. There was a huge lake‑effect snow event in Tug Hill during the 1997–1998 winter. It occurred on January 11–12, 1997, when a massive storm produced a 77‑inch, 24‑hour snowfall at Montague, NY National Centers for Environmental Information. This was the highest recorded 24‑hour snowfall in the United States at the time, but a federal review committee later concluded it did not meet official standards for a national record Rutgers University Climate Lab.

1997-98 saw very little snow in the coastal Plain of the Middle Atlantic and New England. The I-95 corridor ended up with very little snow. For the winter season from December 1997 through February 1998, Washington, D.C. recorded only 0.1 inches of snow for the entire season, Philadelphia recorded a total of 0.8 inches of snow for the season, NYC’s total for the entire winter was 5.5 inches. Boston ended up better with Boston recorded 56.8 inches. Much of this is the result of late season blizzards.

For Maryland, the 1997–1998 winter was mild and wetter than normal, with above-average temperatures and precipitation. The El Niño climate pattern brought a generally warmer, wetter season, with only occasional cold snaps and snow events. The region avoided the extreme cold or flooding seen in other parts of the country, but residents experienced more rain and occasional icy conditions.

What does all of this tell us about this winter?

Here is a look at a typical winter pattern during El Nino

NOAA has released their 3-month forecast for December, January, and February across the United States from 2026 to 2027. The forecast calls for above average temperatures and below average. 

Precipitation for the northern half of the United States, above average precipitation and near normal temperatures for the southern half.

Summary

Above-normal temperatures are favored across much of the East. This could increase the frequency of rain or mixed precipitation at lower elevations, but it does not rule out major snowstorms.

A strong southern jet stream can provide moisture for East Coast storms. If enough cold air is available, that moisture can produce a significant nor’easter. Without sustained cold, the same storm track may produce rain along the coast and snow farther inland or at higher elevations. Other very strong El Ninos have experienced things like this.

If this El Nino reaches its projected strength, the Northeast is likely to be milder and drier than average, with warmer temperatures and reduced snowfall compared to recent years. However, the exact outcome depends on the timing and strength of the jet stream, so forecasts will be updated as the season approaches.

Parts of the Great Lakes sit near where that drier northern signal is expected to setup, while the Mid-Atlantic and portions of the eastern United States are closer to the wetter southern storm track.

The snowbelt regions downwind of Lake Erie and Lake Ontario, likely will be cold enough at times to get lake effect snowstorms, Past winters that featured a strong El Nino saw average to slightly below average snowfall. But due to variable temperature patterns it was hard to keep much of a snowpack. Winter 2026-2027 could see a similar problem.

Coastal New England: Warmer temperatures, more variable snow, and possible and wetter conditions in some years.

Atlantic coast: Warmer air masses from the Gulf Stream can keep coastal areas milder and wetter in some winters.

Middle Atlantic Coast and I-95 corridor from Washington DC to Boston, will likely see a milder winter with average to lower-than-average snowfall, but that will depend on how strong El Nino gets.

Interior and higher elevations: May see more snow than coastal areas, but still likely less than average if this is indeed a strong El Nino year.

Depending on the timing of particular setups, several Ice storms are on the table. One or two of these could be crippling like we saw in 1998.  

The snowbelts off of Lake Erie and Lake Ontario, could see average to slightly below average overall snowfall. But with frequent times of milder temperatures a deep snowpack might be hard to come-by.

I know the hype just about everywhere is talking about super El Nino and this being the strongest in record history, signaling doom and gloom with massive impacts. But as I’ve shown many other variables can alter things.  While a very strong super El Nino is very possible, there is still a chance it won’t end up as strong as people think. Over the next several months we will see how things trend.

I hope you found this post interesting and educational. Please leave a comment on what you thought. And if you liked it, let others know and see it.

I will likely release the first outlook post on the 2026-2027 winter sometime in October.