2022 2023 winter outlook for the Northeast Part Three

 

Well, this is it, I’m finely ready to post part three, with my thoughts for the 2022 -2023 winter.

November started out very warm, due to that strong ridge in the Jet Stream, that allowed a lot of warm southern air to invade the Northeast and Middle Atlantic region. with the entire region breaking several record day time highs and setting record nighttime high lows.  But by Mid-November that all came to a crashing halt.  This pattern change was well telegraphed, and I warned all y’all about it several weeks in advance.  With the pattern flip and return of the cold, and with Thanksgiving behind us many are now thinking about the winter and what that might bring.

This will be the third and final part of my 2022-2023  winter outlook series for the Northeast and Northern Middle Atlantic region. 

Link to part one

Link to part two

 Part one and two went into several points that will have major influences for our region this winter. These points look to still be in place and look to remain that way.

 Last Winter:

Like the winter before it, the 2021-2022 was a La Nina winter. Both winters behaved very much like we would expect a La Nina to act like. During the winter of 2021-2022, the polar vortex was relatively strong, but it did stretch a few times bringing some cold air into the Northeast. While the Northeast and Northern Middle Atlantic Region didn’t see a real cold winter, temperatures outside of a large part of Western Pennsylvania, where overall temperatures averaged well above average, most of the rest of the region, ended up with overall temperatures right around average.

Precipitation wise, the Northeast and Northern Middle Atlantic Region, saw a large variation. Most of the region saw below to well below average, with far northern New York State and far eastern Maine, ended up overall average, with far Western New York State and Pennsylvania ended above average. Snowfall wise much of the region ended up with below average snowfall.

Last winter in the major cities, Washington DC ended up with 13.2 inches, which is about half of an inch below their average. New York City ended up with 17.9, which is almost 12 inches below the seasonal average, Boston ended up with 54 inches.

Climate.gov images based on CPC data.

 

Winter 2022-2023:

Let me address the elephant in the room. There is no doubt that globally, nationally, and locally we’re warmer on average than we were 50 years ago. I’ve never said we’re not warming; I’ve just disagreed with the notion that most of the warming is due to human caused warming. But no matter your view on the subject, we are warming. The extra warming in the atmosphere, means the air can hold more water vapor, so during the summer we have a chance to see more heavy rain events. During the winter,  it means we have a better chance to make snow lovers happy. Those warm SST offshore combined with the large temperature gradient (difference) between the Atlantic and land and the extra moisture in the atmosphere, leads to a greater chance for widespread winter precipitation events. But potential doesn’t mean it will happen with every storm that comes through, as aways it’s a matter of timing and track. Because atmospheric temperatures are generally warmer than they were 50 years ago, it can make it more difficult to sort out the pattern, for what may or may not occur.  

The pre winter pattern:

The pattern over the last 7 to 8 months has been busy across the Northeast.  We had several strong inland and coastal lows, some of these ended up stalling off the Coast. Then the first in a series of Summer and Fall Nor’easters occurred in Mid-August. The number of coastal storms and early season nor’easters represents a pattern than can repeat throughout the season. We also had tropical impacts from Nicole and Ian over parts of the region.  October landfalling East Coast hurricanes and landfalling Florida November Hurricanes, do have a correlation to colder and a more active winter pattern here in the Northeast.  We had an East Coast Landfall in November 1935, the following winter of 1935-1936 was extremely cold and snowy. Then we had Hurricane Kate, make an East Coast landfall in November of 1985. The winter of 1985-1986 was extremely cold and snowy.

Polar Vortex:

When the Polar Vortex weakens and or wobbles, cold arctic air moves into the lower latitudes.  This cold air can drop into Asia, Europe, or North America.

Our winter pattern started with Hurricane Fiona in September. When Fiona made landfall on Atlantic Canada with 105 mph winds, it started the line of dominoes to fall, as Fiona continued into the Arctic Circle. 

Nicole led to a weakness in the atmosphere that resulted in colder air sweeping into parts of the region, as well as yet another nor’easter.

Hurricane Martin was the furthest North forming November Hurricane in the Atlantic on record.

All of this tropical activity had a impact on the upcoming winter pattern. 

We just had our record-breaking Lake Effect Snow Event, due to the Polar Vortex buckling sending very cold air over the warm Great Lakes. While this wasn’t a major snowstorm across the region, it was the result of an arctic blast. Currently the polar vortex is redeveloping. The winter of 2014-2015 saw a similar severe lake effect event that occurred on the 17-19th of November.  In fact, many winters that saw early lake effect events like this ended up being active with below average temperatures.

But correlation is not causation.

Sea Surface Temperature Anomaly:

 

Looking at the latest global ocean anomalies, you can see the cold La Nina standing out in the tropical Pacific. We also see cooling developing along the west coast of North America, with a very warm pool in the northern west Pacific

Analogues:

For the analogues I’ve finely come up with these six years.

1935-1936, 1966-1967, 1984-1985, 1995-1996, 2010-2011, 2013-2014. The winter of 2014-2015 pattern didn't match the pattern, quite as well, but it could have been used, If I had used seven analogues, it would have skewed the results to even a colder and snowier winter.

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Teleconnections:

This winter is featuring a rare tropical dip La Nina. The La Nina should be moderate to weak. Currently the La Nina is still basically east based. The current strength of the La Nina is moderate, we can see this with the Southern Oscillation Index (SOI) value over the last 90 days has been 14.47, when the SOI is generally between 14 and 20, the La Nina is considered moderate.

Here is a look at the IRI probability forecast. It predicts the current moderate La Nina will weaken and become weak during the 2^nd half of winter, likely transitioning to neutral during spring 2023.     

 

 I discussed the La Nina in parts one and two. So, no need to go into a lot of detail.

 

Pacific decadal Oscillation (PDO):

Looking at the Sea Surface Temperature Anomaly above, currently the PDO is generally negative. But, in part two, I talked about how the PDO looked to be trying to turn positive. The cooler SST pool in the Gulf of Alaska has expanded, and as I said above there does appear to be cooling trying to develop off the West Coast. So, it is still possible the PDO could become neutral or go positive.  The warm Atlantic stands out as well. 

 

The Quasi-Biennial Oscillation:

QBO is looking to be positive (westerly)

The QBO deals with winds in the stratosphere above the equator. This belt of winds circles around the equator. The wind direction generally switches direction every 14 months. 

On average winters that feature a positive QBO, tend to be milder for the Eastern CONUS. This is because there is less tendency for the polar vortex to become disrupted.  

Pacific North American Pattern (PNA):

We have the higher heights in the Gulf of Alaska, lower heights in the Aleutians, and higher heights over Florida.  So, we should see the PNA become predominantly positive this winter.

Eastern Pacific Oscillation (EPO):

The EPO is negative, with the current strength of the ridging into Alaska, I think the EPO should remain mainly negative for much of winter 2022-2023. This will help in displacing the cold air into the Great Lakes and East.

 Indian Ocean Dipole (IOD)

The IOD deals with variations in the difference between the SST in the tropical Western and Eastern Indian Ocean.

The IOD was negative, but it has been weakening. The most recent value is -0.06 which means it is now- neutral.  When the IOD is negative, Lower 48 typically see warmer than average temperatures. With the IOD currently neutral and heading toward positive. It would be an indicator for cooler than average temperatures.

Atlantic Multi-decadal Oscillation:

The AMO is a very long term (decadal) oscillation, meaning it doesn’t flip every few years. Currently, the AMO is in its positive (warm) phase AMO. Looking at the chart (blue is negative and red is positive), we can see the last negative phase went generally from the early 1960’s into the early 2000’s. Then we flipped to the positive phase, outside of a few variations we’ve been long term phase ever since.  

Why is this important? Warm SSTs in the northern Atlantic, can increase precipitation amounts for us here in the Northeast and Middle Atlantic Region.

Madden Julian Oscillation (MJO):

The MJO is a tropical pattern, involving an eastward atmospheric pattern and rainfall, that circles the earth every 30 to 60 days. It broken down into 8 phases.  It is known to have big influence a variety of weather patterns around the globe. There is a significant relationship between the phases of the MJO and the frequency of nor’easters.

When the MJO is in phases 7, 8, and 1, chances of snowfall are increased. Chances of snowfall are decreased for MJO phases 4 and 5. Research has shown Nor’easters are more numerus when the MJO is in phases 7 and 8.

Teleconnections are important, but they’re not the end all say all. They will give you an overall broad brush as to what the pattern looks to generally do. But they don’t tell you where the ridges and troughs will setup, or where the individual storms will track.

 

Eurasian and Northern Hemisphere Snowfall Extent:

Snow extent has grown very fast over the last 30 days. Snow extent over East Asia has been fairly robust and currently is above the 30-year average. In fact, snow extent across the entire northern Hemisphere is well above average.  Russia is almost completely covered in snow, Alaska and Canada have been inundated with snow, and extends farther south over the Lower 48 than the average. But the snow extent is the largest it has been in 56 years.

Extensive snow extent early in the season is an indicator of the amount of colder air available in the pattern has we head into Winter.   But across Western Asia, snowfall hasn’t been as pronounced.  The idea that snow extent is deep and expanding across Siberia, is a good sign for an expansive pool of cold air over that region. If this happens, there is a much greater chance for disruptions in the Polar Vortex, leading to chances for cold outbreaks across North America.  

When we look back at the winters that had a similar snow extent; the Northeast and Middle Atlantic had overall cold and snowy winters. These winters also featured severe lake effect snow storms; we’ve just had one 10 days ago. With another big lake effect event occurring tomorrow. 

   

 

 The predominate winter storm types:

Clippers, Cutters, Miller B nor’easter and Miller A nor’easter

Clippers, drop out of Western Canada drop into the Upper Midwest and then move somewhere between the Northeast and the Delmarva Peninsula. These typically bring light to moderate snow events. 

Cutters, move up the coast along the Appalachian Mountains. Depending on how they track they can bring a mix of precipitation types. 

Miller B’s many times start out as a clipper type system, but they end up transferring to a 2^nd low offshore. These complex storms move fairly slow but can bring big snow but who sees heavy snow depends more on timing.

Miller A’s typically start over the Gulf of Mexico then moves up the Coast. Miller A’s are what is normally called a classic Nor’easter, and can move slowly or very fast. Miller A’s can bring widespread heavy snow who sees how much depends on the storm track.

 

November has been very active, we’re seeing lots of storms moving up into the Great Lakes (which is quite common this time of year), and more than a few coming up the coast. These storms have brought a lot of winter type with them, when we look back at winters that had similar November’s they ended up being quite wintery.   

The last part of November has seen a warming trend. Looking at the teleconnections this mild pattern should last into around December 5^th. After that, a much more wintery pattern develops. At that time, we will have a strong ridge across Alaska and Greenland, as a result of the negative EPO, negative AO and the negative NAO.  We should have troughing setting up over the Plains for the end of November, this would likely expand east as we get into December. This is likely to be widespread and long-lasting cold East of the Rockies, with chances for snow storms due to that active subtropical Jet.  The MJO is looking to move into Phase 7 as we get into December, As I said above, when the MJO is in phases 7,8 and 1 the chances for coastal snowstorms increases along the East Coast. We also look to have another disruption in the Polar Vortex, for the first part of January. 

Many outlets are keying on La Nina being the major influence for this upcoming winter season. Typically, during La Nina the subtropical jet stream is weaker, which means less moisture available over the East Coast, with a lesser chance for phasing developing for bigger snowstorm potential. But less moisture doesn’t mean no snow…when we average all La Nina years, snowfall patterns across northern New York State and northern New England tend to be above average, with the rest of the region typically seeing below average snowfall. Since no two La Nina’s are exactly the same, that can vary.  

For this winter, I’m betting on La Nina not being typical or the main driver of this winter. Many times, during La Nina we see a predominate zonal flow, with a firehose of moisture coming off the Pacific and working across the CONUS. For winter 2022-2023 I don’t see that being the case.  There is a lot of amplitude over the Pacific, with a steep ridge building into the Aleutian Islands. We have a very active southern subtropical jet stream. I covered the reasons for this in parts one and two. This active subtropical jet stream is more than likely going to distort the influence from La Nina. As I said in part one and two. The Hunga Tonga Volcano huge water vapor ejection is the reason for the subtropical jet being and staying so active, due to the imbalance it set into motion. So, it will have a big impact on our winter weather.

What could go wrong:

Southeast ridge when this pushes north it might overwhelm the pattern, especially for the Mid Atlantic. The Tonga Volcanic eruption is another wild card. An event like this that pushed so much water vapor into the atmosphere, has never been witness in recorded weather history, so we’re in new territory. If it behaves different than I anticipate it will throw the entire outlook into the dumpster. Another wild card will be the chance that this La Nina will be more of a hybrid than I anticipate .   The MJO will be another wildcard. MJO phases will be critical in how the winter storms behave.

OK so what about the Northeast and northern Middle Atlantic this winter:

To call for the type of winter I am, is a bold statement, most outlets are calling for the exact opposite. But I have to trust in the data, and what I see! 

I still think this is going to be a front-loaded winter. Winter starts early with December being overall quite cold. With the Pattern setting up, there should be several snow chances.   It does look like we’re going to see another polar vortex event during the first 10 days of December. We could see it very cold near or over Christmas, with the chance for some snow.  As I said, in the earlier parts of this outlook, the polar vortex for this winter is looking to be fairly weak.  This winter is going to be very active, so the idea of a weak polar vortex is a good thing if you want to see cold and snow.

So, with December into at least Mid-January looking to be generally cold and snowy. That’s next? Well, I think we’re going to see a lull develop for the last part of January and well into February. But that doesn’t mean there won’t be cold shots, depending on timing there could be chances for snow during this time as well.  Then for the end of February into March we could see a better chance for a few larger snowstorms.  

The pattern I’ve described, means this isn’t going to be the type of winter we’ve become accustomed to the last several years. The pattern means several nor’easters are likely this winter, but not all of them will have a track that brings widespread heavy snow.

Well that's it....We will see how things work out. 

2022 2023 winter outlook for the Northeast part two

 

Welcome to part two of my 2022-2023 winter outlook. Part, one went into this seasons triple dip La Nina, a few teleconnections, and the Hunga Tonga Volcanic eruption. Part one, showed how both of those are arguing for a colder than average winter for a large part of the Northeast.  Part two will go into the Pacific Decadal Oscillation, the Eastern Pacific Oscillation, the Quasi Biennial Oscillation, and the Pacific North American Pattern, and how they detract or enhance the atmospheric effect of the La Nina and Volcanic eruption. Part two will go into possible storm tracks we should see this winter. As well as some thoughts on the Polar Vortex. I will also go more into analogue winters and make some adjustment from part one.

 2022-2023 winter outlook part one

Teleconnections:

 

Pacific Decadal Oscillation (PDO):

The PDO is a change in the Sea Surface Temperatures pattern in the North Pacific Ocean above 20-degree north latitude. Like all teleconnections the PDO has a positive (warm) phase and a negative (cool) phase. Generally during the positive phase, warmer SST exist along the Northwest Coast and West Coast of Canada. During the positive phase the wintertime temperatures tend to be warmer across the western CONUS and cooler in the eastern CONUS, during the negative phase the opposite is generally true. The Phases of the PDO can enhance or diminish the effects caused by the ENSO. So, when we have a negative PDO during a La Nina, it can increase the impacts on temperature and precipitation patterns typical of La Nina. The last two winters involved negative PDO’s.

When we look at the SST in the northern Pacific, we can see those warm SST off the West Coast south of Alaska. It seems the PDO is starting to turn positive.

 

The La Nina, PDO and the Hunga Tonga Hunga eruption will make this winter very distinctive:

As I said in part one, this winter is going to feature a triple dip weak to moderate East Based La Nina. The fact that we look to see a positive PDO during this coming winter, is a big deal. Every other triple dip La Nina had a negative PDO. So, therefor they enhanced the La Nina in those winters. So clearly as rare as these triple dip La Nina’s are, this one is going to be one of kind. Looking back at La Nina winters that had a positive PDO, we come up with 1908-1909, 1938-1939, 1984-1985, 1995-1996 and 2005-2006.

Only 95-96 featured a weak polar vortex and a strong very persistent negative phase of the AO and NAO. That winter was an extremely snowy winter. Due to how the pattern for the entire winter was perfect for winter storms. So that doesn’t mean this winter would end up the same. But, each one of these winters featured average to above average snowfall across our region.

Hunga Tonga Hunga volcano:

In part one I went into some detail on the Hunga Tonga Hunga eruption. But that volcanic eruption is so unique, that it forces me to talk more about it and the impacts it could bring for this winter.

Here are a couple of images that show the amount of Water Vapor from the eruption and its distribution across the globe. We can see that the amount of water vapor released is astonishing. We can also see that the vast majority of the stratospheric water vapor is confined to the Southern Hemisphere.  The amount and distribution are going to have a big say in this winter’s temperature and precipitation pattern. In fact, the eruption aftereffects are the main reason this hurricane season has acted the way it has.

 

It all comes down to balance, or in this case the lack of balance.

In part one I showed the stratospheric cooling at occurred in the Southern Hemisphere. When we go to see the stratospheric data from the CPC and look at the 30hPa layer of the Southern Stratosphere we can see that the current temperature (shown by the red line, is at a historically low level. It is well below the base line. The 50hPa layer shows the same kind of well below average cooling. All of this rapid cooling was a result of all that water vapor being sent into the Southern Hemisphere stratosphere causing the upper atmosphere to contract.  As a result of the upper atmospheric cooling the troposphere ended up warming due to the expansion of the lower atmosphere

But when we look at the stratospheric data for the Northern Hemisphere, we see the exact opposite, those 30hPa and 50hPa layer temperatures are above average.

The Subtropical Jet has been very active this year; which is very atypical for a La Nina year. This is one of the main reasons this year’s hurricane season turned out the way it did. The Northern Hemisphere atmospheric profile was a blend of La Nina and El Nino; which led to all that extra windshear over the tropical Atlantic due to the active subtropical jet. So that well above average hurricane season forecast, never had a chance to get going. This was all a result of the global atmospheric circulation trying to find balance. This is already affecting the polar vortex over the Arctic. In these images we can see while the Polar Vortex over the Antarctic is very strong and well defined. The Polar Vortex over the Arctic is very weak and very elongated.

North 

 

South

Source Earth Null School

As this pattern continues, the Subtropical jet is going to be much more active for the 2022-2023 winter than is typical of a La Nina winter.  With the Polar Jet being active and also having an active Subtropical Jet; there is going to be increased chances for phasing involving the Northern and Southern Jets. How this phasing comes about will be determined by these winters storm tracks.

 

Other important Teleconnections:

The Quasi Biennial Oscillation (QBO):

The QBO deals with the variation in wind flow in the lower stratosphere at the 30hPA layer above the equator. The QBO can influence weather patterns across the globe. This alternating belt of strong stratospheric wind completely changes direction right around every 14 months. So, the full cycle is roughly 28 months. When the winds are westerly (WQBO) the QBO is in its positive phase. So, when they blow in the easterly (EQBO) direction the QBO is in its negative phase.  The QBO has in influence on the strength of the jet stream, polar vortex and the likelihood of high latitude blocking.

During the positive phase winter temperatures across northern New York State into Northern New England are more likely to be colder than average, with the Mid Atlantic and New England likely to be drier than average. During the negative phase the cold shifts south a bit; so Central and Southern New York State, Southern New England, Pennsylvania, and the Middle Atlantic to be cooler than average. During the negative phase the entire Northeast and Northern Middle Atlantic tend to be drier than average.

Here is a look at the QBO composites

 

Source…Philly Weather Authority

Dec – Feb Temperature and Precipitation anomaly probability maps.

Westerly QBO

 

 

Source World Climate Service

Eastern QBO

 

 

Source World Climate Service

Last winter the QBO was negative; currently the QBO is in a positive phase. As of September, the index was at +9.80.

This year has seen the upper atmospheric winds fairly weak. Could this have something to do with the volcanic eruption back in January? Maybe. With this, it should lend some support for high latitude blocking and a decent chance for some stratospheric warming here in the Northern Hemisphere.

 

 

The Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO):

The AO is a northern hemisphere circulation pattern that influences the position of the northern jet stream. It also has some influence on the strength of the polar jet as well as the strength of the Polar Vortex.

During the positive phase the Northeast and Northern Mid Atlantic Region generally see warmer and more moderate winters. During a positive phase of the AO, the Polar Vortex is generally strong.

During the negative phase the Northeast and Northern Mid-Atlantic Region generally see more in the way of cold and stormy winters. During a negative phase of the AO, the Polar Vortex is generally weaker.

The NAO deals with the air pressure pattern between Greenland and the Azores. During the positive phase, the CONUS generally sees a Zonal west-east flow, which typically keeps the cold air bottled up in Canada; this is generally because we see little high latitude blocking during the positive phase of the NAO. 

During the negative phase, we generally see a lot of high latitude blocking over Greenland. The blocking forces the Jet stream to buckle, bringing cold air outbreaks into the Great Lakes and Northeast.

 

 

When we see an east based La Nina, typically we see a predominate negative AO and NAO.

 

 Pacific North American Pattern (PNA):

When the PNA is positive generally in Western Canada and the Western CONUS. it is warmer than average and the Eastern CONUS. is colder than average, there is also a tendency for the eastern CONUS to see below average precipitation as well. When it’s negative, we see the opposite occur more times than not. Currently the PNA is in a positive phase.

 

 

Courtesy of the NWS Climate Prediction Center

Given the overall setup, I favor the idea of the PNA being primarily positive this winter.  

 

Eastern Pacific Oscillation (EPO):

The EPO deals with the atmospheric flow pattern across the Eastern Pacific including Alaska. In other words, the EPO is about the placement of the trough around the Aleutians into the Gulf of Alaska. During a positive EPO the trough is located in the Central and Eastern Gulf of Alaska. As a result, we see strong Pacific jet pushing in a mild north Pacific air flow pattern into the Western CONUS, as this air flows over and down the Eastern slopes of the Rocky Mountains, it warms up and dries out. This typically results in warmer than average temperatures across the Central and Eastern CONUS. During a negative EPO the trough is centered in the Aleutians into the Western Gulf of Alaska. This results in a ridge over the Eastern Pacific off the West Coast. Because of the ridge, the western flow of that mild Pacific air is diverted up toward Alaska.  As Alaska warms, we see the cold Arctic air displaced and forced to move down the western ridge into the Central CONUS. Because of this the Plains and Great Lakes tend to be very cold, some of this cold migrates East into the Northeast and Northern Middle Atlantic.  So typically, our region tends to see colder overall temperatures during a negative EPO.

 

This winter the EPO is going to be the composer, controlling how all these factors mesh. Because the EPO has a major influence on storm tracks across North America.

 

Storm Tracks:

This winter’s storm tracks will be based on the idea of moderate East Based La Nina that will weaken as we get into Midwinter, this along with the pattern setup caused by a positive PDO that interacts with a primarily negative AO and negative NAO and the phase orientation of the EPO during the winter of 2022-2023. This will be enhanced by the results of the Hunga Tonga Volcanic eruption making for a very active subtropical jet, and the increased chances for higher latitude blocking over Greenland due to the QBO. The type of storm and precipitation type will be mainly determined by the phase of the EPO and NAO; these are variable and so we will see a range in outcomes.  

 

When the EPO is positive, the pattern would favor a general storm track into the Great Lakes.  A positive NAO would mean a lot of snow into the Western Great Lakes. We would expect mixing over the interior parts of the Northeast into the Eastern Great Lakes, with a quick change over to rain along the coast. If the NAO is negative, The Northeast would expect to see a substantial mixed precipitation type storm.

When the EPO is negative, the pattern would favor a general snowstorm in the Northeast and Middle Atlantic.  A positive NAO would mean a less chance for phasing between the northern and southern jets, with a general track farther from the coast, this would favor snow for interior New York State and Pennsylvania, leaving the Middle Atlantic and New England more likely a missing out on heavy snow. If the NAO is negative, The Northeast and Middle Atlantic would expect to see a substantial winter storm, due to the high likelihood of both jet streams phasing, with even the potential for a triple phase event. A triple phase storm is when we see the subtropical Jet, the Pacific Jet and the Polar Jet all phase. A true triple phase snowstorm is rare but when they occur, they end up as monster snowstorms.  The pattern this year is going to favor the chance for Miller A and Miller B nor’easters.

Types of winter storms link

Polar Vortex:

As I showed earlier the Polar Vortex has been very disrupted and fairly weak. Now while the Polar Vortex is strengthening as it should be at this time of year. But given the factors I went over; I don’t see the Polar Vortex becoming strong this winter. So it will be easier for the vortex to elongate and split.

 

Analogues:

1908-1909, 1938-1939, 1984-1985, 1990-1991, 1995-1996, 2005-2006, 2010-2011, 2013-2014.

These analogues are based on winters that had a positive PDO with an East based La Nina, had similar SST pattern, and a cool southern hemisphere.

Conclusion:

In part one I discussed how December and January look to be active and wintery. I still believe this to be the case. It is unclear how the end of February into March will act due to the weakening La Nina.

I believe the polar vortex will be weak and will have the potential to be disrupted several times.

The subtropical jet is going to stay active right through the winter, which is something we don’t typically see during a La Nina winter.  

 

Based on the analysis so far, I think this winter will end up colder overall than I indicated it would be in part one. The pattern is looking to be very active with the chance for several cold outbreaks. The pattern should produce several opportunities storm tracks near and offshore, with the idea of prevalent blocking over Greenland due to a general negative NAO, the chance for these storms phasing will be rather high. As for the Lower Great Lakes, this looks to be an active lake effect snow winter.  

Eastern Long Island along the Connecticut Coast into Rhode Island, look to see near average temperatures, and average snowfall.

For Maryland, the major Cities along the I-95 Corridor, Eastern Long Island, Southeastern Massachusetts including Boston will see average to slightly above average snowfall with overall temperatures ending up around average.

For much of the rest of the interior Pennsylvania, New York State and New England, generally below average overall temperatures with snowfall ending up above average.  This is looking to be a good Lake effect snow winter.  

 

Well, that’s it. I will be releasing part three end of November into the first week of December. Part three will cover the overall trend that has been occurring since part two was released, and will attempt to narrow things down a bit more.

 

 

 

 

 

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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