Winter 2025-2026 update

 It's been around 14 days since my last update for the upcoming winter. So I guess it's about time to touch on the subject again and show how things seem to be evolving.

So far activity during the 2025 hurricane season in the Atlantic is running well below average with only seven named systems for the season, five tropical storms and two hurricanes both of them considered major hurricanes.

We are now past the peak of the Atlantic hurricane season and Accumulated Cyclone Energy  (ACE) Is running a little more than 50% of what is considered average for this point in the season. Ace is used as a metric to try to determine the overall strength and duration of tropical cyclone activity in the Atlantic during the season. The higher the total number the more active and generally impactful the season.  The rest of the season will have to become very active or we will have to have at least a couple of long lived hurricanes to revert us back to average. Other seasons to have an ACE index at least this low at this point at this point in the season are 2002, 2009 and 2013 through 2015.

When I posted the hurricane outlook I had called for an above average year. But while we still have time to go in the season it's starting to look like I was probably wrong. .with still the chance For a brief and weak la Nina As we get into October and November it's possible the Atlantic could become a little bit more active  So we will see.

While there is no strong correlation between a  hurricane season activity and the following winter time weather. But I think, overall tropical seasonal activity Can affect a pattern.  It'  involving energy transfer. In this way the pattern that led to a certain type Of hurricane season can lead to the creation of another type of weather pattern that can impact the winter  precipitation and temperature patterns.If y'all remember your high school science, you know that energy can't be created or destroyed It can only be transferred or dispersed. So even though we can't point to a specific correlation,  logic dictates there has to be one.

Current global sea surface temperature anomalies.

Image credit tropical tidbits.

The El Nino southern Oscillation (ENSO):

In my last post for the upcoming winter I went into a lot of detail on the ENSO. So if some of y'all don't know what that is, or can't remember, y'all can go back and read that one

We're still officially in a La Nina watch, which means SST's in the equatorial pacific are considered near average at this time. The overall setup in the pacific Equatorial regions Hasn't changed all that much from when I last posted on the ENSO.So I still think we are going to head into a short lived La Nina as we had into winter 2025-2026 and then we will revert back to ENSO neutral conditions for the rest of winter. 

As I've been saying If this occurs We will have a better chance for a generally colder than average winter with generally overall above average snowfall for at least parts of the region a strong possibility.

The ENSO/La Nina is a major teleconnection But there are still many other teleconnections that we have to consider when trying to put together a seasonal forecast. With this seasons La Nina looking to be very weak if at all. Other teleconnections will have a greater chance to override the pattern that will try to set up due to La Nina.

Arctic sea ice extent:

It looks like arctic sea ice extent for 2025 has reached its minimum and is now starting to expand again. The end of the summer melting season shows ice extent slightly higher than it was at this time in 2024. For the last 13 years end of season ice extent has been greater than it was at the record low set in 2012.

The reason for this is Summer time temperatures in the arctic have been average to slightly below average for the last several years, This is likely to to the increasing atmosphere water vapor concentration levels.

Image credit Danish meteorological institute

Eurasian and Alaskan snowfall:

Snowfall Is starting to accumulate across northern parts of Siberia as well as Alaska

Image credit US national ice center.

We're heading towards October; The month where Eurasia sees it's greatest expanse in snowfall extent. So moving forward we will see much more snow accumulate over Siberia.

Doctor Judah Cohen Discovered several years ago a connection between Asian snowfall extent during October and its effect on winter here in the United States. The theory, is the greater the snowfall extent In October the more likely we are to see a negative arctic oscillation (AO). A persistent negative AO favors overall colder than average conditions during winter here in Northeast into the northern Middle Atlantic.

This time last year there was much less snow cover over Siberia and Alaska. With more snow cover over Siberia and Alaska Along with more ice extent in the bering sea The Arctic in the Northern Hemisphere is building cold and it's colder than it was this time last year. This will in turn allow more snow to fall and even greater ice extent.

Both of these things  as we move through October into November will keep the cold air building, As all the factors create a feedback on itself.

The warm water in the North Pacific:

If you've been reading these upcoming winter post you know all that warm water in the  North Pacific is something I keep coming back to time after time. This is because I think this is going to be a major factor involving a pattern for this upcoming winter.

Looking at the SST chart we can see the above average warm SST's in the North Pacific. This area is sometimes called the "Blob" Stretches across the entire North Pacific.

The blob will likely cause a steep high pressure ridge over the Pacific Northwest and a persistent trough in the eastern half of the US. This can lead to a shift in the jet stream, pushing it further eastward. which can lead to a disruption of the polar vortex and potentially lead to an overall colder and wetter winter for parts of the Central and East Coast of the United States. 

This would somewhat change the typical La Nina impact  across the US, especially the northern US. We would likely see a variable polar jet and a weaker less active subtropical jet. Those warm waters in the north pacific Likely promote quite a bit of storm development in that part of the pacific If this does occur it could help send warmer air temperatures into Alaska. This would help dislodge the cold of air of over Alaska into the arctic. Allowing the cold air to likely drop down into the central US and extend into the Northeast and Middle Atlantic region.  A prevalent northwest flow could lead to quite a few clippers dropping out of Canada and across the Great Lakes into our region.

Possible analog winters:

In my last winter outlook posted on September 11. I showed a few analog winters and how a composite of those winters worked out as far as cold across our region. The composite showed similar patterns produced a generally colder than average winter here in the northeast into the northern Middle Atlantic

SST 's during September 2013

Right now The overall pattern we have seen this summer into this fall cosely resembles The winter of 2013- 2014. The winter of 2013-2014 is a very good anomaly for the upcoming winter. The winter of 2013- 2014 also featured a neutral ENSO to weak La Nina, a below average Atlantic Hurricane season. That winter also saw big cold outbreaks and a lot of snowfall across many parts of the Northeast.

2008-2009 also had a similar pattern to what looks to be developing for this winter. During that winter December through the end of February saw a large part of the region Seeing overall cooler than average temperatures. But Maryland, Delaware into New Jersey saw slightly above average temperatures during the same time.

Based on the pattern that appears to be setting up. I still believe this winter is generally going to be overall colder than average for much of New England, New York State  into Pennsylvania, With Maryland Delaware and the southern half of New Jersey Looking to be closer to average to maybe slightly above average. The general overall snowfall across the region looks to be similar to what I laid out in my last post on winter 2025-2026.

Well that's it for now, I will likely release another update on the upcoming winter in a week or two.