The 2022 2023 Winter Outlook for the Northeast Part one.

 

Part one of the winter outlook will be largely based on analysis of Sea Surface Temperatures (particularly those in the equatorial Pacific), looking at possible analog years, snow extent across Siberia, and the possibility for high latitude blocking events and how that ties in with the Southern Hemisphere volcanic eruption in January of this year.

What is a seasonal outlook?

A seasonal outlook isn’t like short range and medium range forecast, trying to accurately forecast something like an entire winter season is a complicated process. At the start it looks at how temperature and precipitation are trending, using tools like satellites, radar, and automated surface observations. Then comparing a variety of atmospheric and oceanic factors as well as things like are snow cover and soil wetness; these are teleconnections and other indicators. Using these can give some insight into possible weather patterns that those factors could lead to. Then looking at computer output and looking at past years that had a similar look are taken into consideration. The closer the analogue pattern is to the current pattern, the more weight it is given. Then this information is compiled, then apply their experience and applying climatology for a given area and local geography, to try to come up with a general long-term weather average, of what is likely to occur over the next three to four months.

 

This is only October based on early analysis, there is time for things to change. So I expect to see some changes in the pattern, that could alter things enough to make me adjust what I’m seeing right now.

 

Okay let’s start the discussion, on what I think is going to happen.

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The El Nino and Southern Oscillation (ENSO):

The ENSO involves Sea Surface Temperature (SST) anomalies across the equatorial Pacific.  ENSO consist of a warm phase, a neutral phase, and a cool phase. La Nina is the colder phase, these various phases typically cycle every three to seven years. These changes disrupt wind, cloud, and pressure patterns over the Pacific, triggering temperature and precipitation changes across the planet.  

It’s important to remember that La Nina’s are not all the same. The region can see different outcomes depending on the placement of the La Nina, as well as if it is considered weak, moderate, or strong. Also, La Nina isn’t the only factor when it comes to the wintertime pattern.

La Nina is still here. So, we can expect it to be a major driver in this upcoming winter’s temperature and precipitation pattern. La Nina’s on average tend to be snowier than average across northern New York State and northern New England. Weak to moderate La Nina’s tend to be snowier over a large part of the Northeast. While strong La Nina’s tend to be much less snowy over southern New England into the Middle Atlantic. The La Nina should stay weak to moderate for this winter.

 

Looking at SST anomalies, we can see the La Nina stands out clearly in the equatorial eastern and central Pacific.  Chart of the ocean analysis shows those cold ocean anomalies in the tropical Pacific spans almost the entire length of the tropical Pacific. Looking more closely at the latest analysis of the ENSO regions below, you can see the strongest cold anomalies returning in the eastern region. Overall, La Nina looks in a healthy state.  The SST chart also shows the warm anomalies in the northern Pacific and northern Atlantic.

This seasons La Nina will be the triple dip La Nina.  This is only the fourth time we’ve seen a triple La Nina since records have been kept, the other winters that were the third in a row was 1955 – 1956, the next one was 1975 -1976, the other was 2000 -2001. Here is a timeline of La Nina events from 1900 to 2022.

Last winter there were several winter storms during January and February. There were also a couple of big coastal snowstorms. Those of Y’all who were in the right place , got a lot of snow out of these coastal storms, while others didn’t see much if anything at all. But the result was that many cities in the I-95 corridor ended up with average to above average snowfall.

 

IRI ENSO model predictions of ENSO, show that this seasons La Nina should extend at least through the heart of winter 2022 – 2023.

 

A large majority of the models in the plume predict SSTs to remain below-normal at the level of a La Nina until at least Dec-Feb 2023.

 

The latest equatorial T Penatd anomaly

Shows subsurface water temperatures in the Pacific are quite cold. This lends a lot of support to the staying power of our current La Nina conditions.

  

On the latest SOI analysis below, we can see persistent positive values with a strong recent burst. Such data further supports stronger trade winds and ocean cooling in the ENSO regions, sustaining and further cooling the La Nina towards Winter 2022/2023.

 

 

As is usually the case in a La Nina, the Southern Ridge will be an influence this winter. For now, I don’t think the southeast ridge will be as influential as it was last winter.

 

Analogue winters:

1955 -1956, 1975-1976, 2000-2001

This shows that 3rd year La Nina’s tend to be colder than average across the Northeast and Middle Atlantic, with northern New York State and northern New England being 2°F to 3°F below average.  As far as the precipitation anomalies Maryland, Delaware, southwestern Pennsylvania, and southern New Jersey tend to see slightly below average  wintertime precipitation, with the rest of the region seeing average to slightly above average wintertime precipitation.

Looking at the analogs for the individual months, third year La Ninas, tend to see winter start early, with both December and January quite cold, then for February and March temperatures warm a bit, so winter 2022 -2023 could end up front loaded.

When we look at years that saw similar Sea Surface Temperature patterns, we’re left with 2005,2013, 2014, 2020, and 2021.

Here are comparisons of our current SST anomalies to those five years.

 

For now, the analogue winters I will use are

1975 -1976, 1985-1986, 2000-2001, 2005,2013, 2014, 2020, and 2021

 

There is a correlation between warm Octobers and October tropical activity and colder winters here in the Northeast and northern Middle Atlantic. It remains to be seen if October ends up overall warmer than average; or if we a couple of tropical cyclones come close or make landfall on the U.S. But if we do, it will increase the odds of a cold winter here in the Northeast.

 

 

Siberian snow cover:

Now that we’re in Mid-October, we can try to get a feel for what’s going in with Siberian snow cover. A few weeks ago, snow cover in Siberia was quickly expanding. In fact, it was the fastest advance in over 12 years. But since then, snow cover advance as slowed down a lot.  So currently Siberian snow cover is at a moderate level when compared to other years. The pattern over that part of the world is such, that I don’t expect to see any big changes in snow extent over the 7-10 days. After that conditions should become more conductive for more in the way of snow, so we should see snow cover expand.

I expect by the end of October snow extent will be above average. The question is will it be slightly above average or well above average. Given the current pause in snowfall over Siberia, it will be an uphill climb to reach well above average. But the pattern that looks to setup says it could be possible. We will see.

 

 

A few teleconnection thoughts:

 

The Madden Julian Oscillation (MJO):

The MJO is currently in phase six. Phase six on average tends to favor ridging over western North America and troughing over eastern North America. This could keep October on the coolish side. A cooler overall October would mean a cold winter would be less likely, but that would only be one factor.

The Atlantic Oscillation (AO):

Right now, the AO is positive. Then it looks to become more neutral for much of the rest of October. I think the AO will become overall negative during the first week of November

The North Atlantic Oscillation (NAO):

While the AO is going to be neutral for a week or two. The NAO looks to be negative during the same time. The NAO will likely stay slightly negative for at least the first part of November.

 

The Hunga Tonga Volcanic eruption:

The eruption in the southern Pacific, Introduced a lot of water vapor and debris into the stratosphere in the Southern Hemisphere. The eruption resulted in a large stratospheric cooling event in the Southern Hemisphere. There is a correlation between what happened in the Southern Hemisphere earlier this year, and high latitude blocking over Greenland and a predominantly negative NAO pattern for this winter.

Years that had similar Southern Hemisphere cooling were 1988,1990,2002,2004, 2009, 2010,2016, 2019,2022  

 

Looking at the 500mb geopotential height composite anomaly those analogue years, based on  1991 2020 climatology  for the winter months of December through February. It clearly shows that idea of an overall negative NAO with higher latitude blocking over Greenland, is a good bet for this winter. 

 

High latitude blocking does tend to increase the odds of cold air outbreak in the Central and Eastern U.S.

 

As far as the Polar Vortex, I don’t think it will be super weak like we’ve seen in winters like 2020-2021. But we still should end up with a few times the polar Vortex breaks down enough to allow some of that arctic air to move into the Northeast.

 

Great Lakes water temperature:

 

Temperatures over the last few weeks have been generally below average. As a result, the water temperatures across the Great Lakes are slightly cooler than average for this time of year. The Lakes will cool down slowly as we head into mid-November. Lake effect snow should be average to above average this winter.

 

 

Images from the PRISM Climate Group at Oregon State University

 

Bottom line, and putting it all together:

On average for the Northeast and northern Middle Atlantic region, La Nina winters tend to be rather chilly, with snow typically ending up a story of the haves and have nots.

This winter looks Likely to have an active northern jet stream and a persistent ridge in the Southeast US. I

 

Because of all the stratospheric cooling earlier this from the Hunga Tonga volcanic eruption , I think there should be a more predominate tendency for the NAO to stay generally negative during winter 2022-2023. Which will lead to a greater chance for blocking over Greenland and increasing the odds for at least some cold air outbreaks. That along with the tendency for triple dip La Nina to be colder than average. I think this winter will be at least somewhat overall colder than the last couple of winters.  

 

Temperatures:

Based on the analogue package I’m currently using, winter 2022-2023 will likely start early. The pattern I see developing will likely be somewhat bookend like, with a lot of cold on the front end, then February could be warmish, before we see a cool down before April.

December into Mid-January is likely to be cold.

The end of January and into Mid-February could be inundated with some milder temperatures. So, there is a chance during that time temperatures will be overall above average for that time of year.

Then March will likely turn chilly again.

Snowfall:

Based on the pattern that looks to setup, interior parts of the region look to be more in the way of snowy, while parts of the Middle Atlantic and southern New England will see less in the way of snow. But all in all I see winter 2022-2023 being more in the way of what some expect winter to look like in our region.

Western and Central Pennsylvania, western into central New York State and into the Adirondacks should end up with snowfall that is  120%  to 130 % of the seasonal average.

 Northern into Central New England  slightly above average with total amounts of 105% to 115% of average.  

For eastern New York State and the Hudson Valley, southern New England, New Jersey, eastern Maryland, Delaware, and New Jersey.   85% to 100%

As for the major coastal cities,  New York City and Boston snowfall looks to be right around average. For cities like Washington D.C., Philadelphia, Baltimore snowfall will most likely be slightly below average to below average.

Snowfall in New England into Maryland, Delaware, and New Jersey, especially for the I-95 Corridor, a lot will depend on the storm track evolving from any Coastal storms that do develop.

 

Well, that’s it for Part one, as we get closer to the official start of winter. I will have a better handle on how things look to trend, as I release part 2 and maybe part three these will try to narrow things down more and provide more detail.

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