The 2023 - 2024 Winter Outlook Part Three.

 

The days and nights are getting colder, most of us have had our killing frost, and some of us have had our first snow of the early season.  So, with the 2023-2024 winter right around the corner, the thought “what is this winter going to be like?” is growing more and more common across the region.  So that means it’s time for my Winter Outlook for the Northeast and Middle Atlantic.  Many of y’all look forward to what could be instore, where I combine a bit of science with pinch of conjecture and a spoonful of past patterns that were similar, and try to come up with the general weather patterns for the coming winter season, trying to show the overall temperature possibilities along with potential snowfall in store for the region.

The last few winters have been lackluster to say the least, many snow lovers would likely say they have been complete disasters. The Northeast has many businesses and communities that rely on winter snowfall for economic wellbeing.  With the idea of a strong El Nino that will impact this upcoming winter, many winter lovers are feeling very antsy.  

Parts one and two laid the groundwork for part three. Part three will go into the El Nino a little bit more, along with some of the different ENSO indexes. I will cover on how the snow extent and ice coverage have been progressing. I will also talk about the Quasi-Biennial Oscillation, or QBO. Lastly, I will try to go into the temperature, precipitation, snowfall amounts, and the storm tracks we could see

If you don't want to read the technical stuff, you can skip to the bottom.

Link to part one

Link to part two

 Sea Surface Temperature anomalies:

 

Above is the latest surface analysis of the global oceans. We can see the marked warm anomalies of the El Nino event in the equatorial Pacific, reaching over 4 degrees Celsius.  The well above average water anomalies also stands out across the Atlantic Basin.

The image below, show SST anomalies in the ENSO region of the equatorial Pacific over the last two years. The blue box shows the La Nina last year and how ocean temperatures quickly warmed to become our current El Nino event. The red box shows the forecasted peak values this El Nino could achieve over the Winter 2023/2024.

 

El Nino Southern Oscillation (ENSO):

ENSO is the most important coupled ocean-atmosphere phenomenon to cause global climate variability. During El Nino, we typically have a very active subtropical jet stream and an amplified polar jet stream. With the extended and amplified subtropical jet with many areas of low pressure moving along it. The southern U.S. typically sees, several storms with lots of precipitation and cooler weather. This general pattern can lead to frequent strong Gulf and East Coast Storms.

You can see exactly that in the jet stream anomaly forecast below for January 2024. It shows the typical strong subtropical jet stream over the southern United States (red).

 

NOAA bases the phase of ENSO by and large on the Oceanic Nino index (ONI).

The ONI is based on SST departures from average in the Nino 3.4 region, and is a principal measure for monitoring, assessing, and predicting ENSO.

Below is an image showing the Nino Regions across the equatorial Pacific

 

El Nino: characterized by a positive ONI greater than or equal to +0.5ºC.

La Nina: characterized by a negative ONI less than or equal to -0.5ºC.

By historical standards, to be classified as a full-fledged El Nino or La Nina episode,

these thresholds must be exceeded for a period of at least 5 consecutive overlapping

3-month seasons.

CPC considers El Nino or La Nina conditions to occur when the monthly Nino3.4 OISST

departures meet or exceed +/- 0.5ºC along with consistent atmospheric features. These

anomalies must also be forecasted to persist for 3 consecutive months.

The IRI multi-model image below show the consensus that El Nino will peak around +2 degrees above normal. That is considered a strong event. But the forecasts also agree that the El Nino will start to dissolve somewhere towards Summer 2024.

 

Based on the ONI, we’re in a strong El Nino right now, with SST anomalies in Nino 3.4 being 1.8°C above average. We will likely see this peak around 2.0°C, before it levels off and then drops back toward a moderate El Nino for the 2^nd half of winter.  I don’t think this El Nino will end up as strong as the Super El Nino of 2015 to 2016.

On the Facebook weather pages and in past blog post, I’ve talked about ENSO indexes, such as the SST anomalies like the ONI and Southern Oscillation Index. The ENSO is the biggest climate driver on the planet, for this reason over the years several ways have come up to measure it.  Besides the SST indexes and SOI, there is the wind index, outgoing longwave radiation index, and the multivariate ENSO index. Each of these Indexes have strong points and limitations.

I want to focus on the multivariate ENSO index (MEI).

The MEI, is a method used to characterize the intensity of an ENSO event. Given that ENSO arises from a complex interaction of a variety of climate systems, MEI is regarded as the most comprehensive index for monitoring ENSO since it combines analysis of oceanic and atmospheric variables.

 While NOAA is showing we’re in a strong El Nino, looking at the MEI images below, we can see it’s showing more in the way of a weak to moderate El Nino. Since sometimes we see more cold and snowy conditions during weak to moderate El Nino’s than we typically do during strong El Nino’s.

 

The way the atmosphere is responding to El Nino, is supporting what the MEI is showing.

 In part one and two, I talked about the North Atlantic Oscillation (NAO), Arctic Oscillation (AO), and the Pacific Decadal Oscillation (PDO).  As I’ve said, The ENSO isn’t the only deciding teleconnection, as other factors have to also be factored in.

Here in the Northeast, the actual correlation from the impact of El Nino is very weak, when compared to many other places. So, it’s very problematic to say El Nino will produce this or that kind of impact here in the Northeast.  So, while the El Nino could likely override the other contributing factors in other parts of the U.S. Here in the Northeast El Nino, might not rule the roost.  For the Northeast our snowfall potential is often driven by the NAO, AO, and other teleconnections including the Madden-Julian Oscillation (MJO). In the previous parts I went into NAO, AO and the PDO. The factors I laid out are still valid. But I do what to talk a bit on the QBO.

 Quasi-Biennial Oscillation:

The QBO, is another teleconnection that is a prime driver of global climate. The QBO is winds in the stratosphere 15km to 50km over our heads. As with all teleconnections the QBO has two phases.  An easterly (negative) phase, when the winds in the stratosphere blow in an easterly direction, and a westerly (positive) phase when the stratospheric winds blow in a westerly direction.  The QBO is very predictable with the phase changes occurring about every 14 months.

The QBO influences the strength of the polar vortex. When the QBO is in a positive phase, the odds for a strong polar vortex increases. During the negative phase the chances increase for the polar vortex to be weaker, increasing the likelihood for some cold air intrusions into the U.S. When the QBO is easterly, there is a better chance for the AO and NAO to be generally negative.

Currently the QBO is negative, this will increase the odds for high latitude blocking along with a better chance for polar vortex disruptions, increasing the odds for cold air incursions during this winter.    

 Eurasian Snow Extent:

In part two, I said, Eurasian Snow cover was below average over Siberia. Since then, more snow as fallen over Siberia.  

 

I’ve placed a box on the Rutgers Snow Extent map, showing the area in Eurasia where we’re concerned with in Siberia. There is a color scale that shows how much above or below average snowfall extent is. The coral tones show where snow cover is below average; whereas, the blue tones show where snow cover is above average. Looking at the map, we can see most of that area is colored in a light shade of blue, which indicates snow extent in Eurasia is slightly above average for this time of year.

 

The Chart from 1967 to 2023 is also showing snow cover is just slightly above average.  Snow cover is indicating a slightly better chance for a colder and more in the way of snowy winter in the Northeast and Middle Atlantic.  As we saw last winter, snowfall was well below average across the region. When we look at the chart, we can see the snow extent was even lower last winter than now.  

 Sea Ice:

On the map from the National Snow and Ice Data Center, I’ve placed a red box over the Barents-Kara Sea.  The map shows the sea ice extent that is monitored for possible influences on our winter weather. We can see that well over half of the area is ice free. The Charts show Ice extent is well below average

Some meteorologist (myself included) thinks the less sea ice over the Barents-Kara Sea, the more likely the chance for the polar vortex to be weaker, increasing the likelihood for cold air intrusions into the U.S.  

 OK let’s get into the Maps and Idea’s I have for the 2023-2024 winter.

 Temperature Outlook for Winter 2023-24:

Even though El Nino’s impact here in the Northeast is a bit tricky, it does produce general impacts. In general, we expect temperatures to run milder than average in moderate to strong El Nino winters.

 

Based on the data I’ve shown, this isn’t likely to  be a downright frigid winter. But we will see cold air outbreaks that extend southward out of Canada from time to time.

Eastern Canada is going to end up with overall below average temperatures -1°F to -3°F. So sometimes we will see cold air outbreaks into the Northeast depending on the timing we could end up with a few major nor’easters.

Around the Great Lakes and far Northern New York State and Northern New England temperatures look to be overall above average

From Pittsburgh up through the Finger Lakes, Central New York State, Northern Hudson Valley, Northern Vermont and Northern New Hampshire into Central Maine, temperatures look to be slightly above average.

For Central Pennsylvania, Central Hudson Valley, Central New England, and Southern Maine will end up with overall average temperatures, +1°F to -1°F for the winter. Southern Maryland, Delaware, and southern New Jersey will end up below average -2°F to -3°F. With the Southeast being well below average temperatures -3°F to -4°F

The upper Great Lakes look to be +2°F to +3°F above average.

 Storm Track Analysis for Winter 2023-24:

The southern subtropical jet is going to stay very active, with a lot of Pacific Moisture moving along it.

There will be frigid air north of the polar Jet

We will have disturbances moving along a fairly active polar Jet. The northern Jet is going to be bouncing around a bit.

The highly amplified and extended subtropical Jet, will support moisture across the southern U.S. The low pressure that will move across the southern U.S. Bringing snowfall across the Southeast. Some of these storms will move up the East Coast, increasing the odds for snowfall across the Middle Atlantic and perhaps Southern New England.

The polar jet is going to be to be just north of the Northeast. Given the pattern that is looking to setup, there is increased chances for sudden stratospheric warming events, that will lead to disruptions in the polar vortex, increasing the odds for cold air intrusions into the Northeast and Middle Atlantic. Given proper timing, there will be snowfall opportunities, especially from Mid-Winter into March.

The image below shows the general pressure pattern during past El Nino events. It shows low pressure over the North Pacific, strong high pressure over Canada and lesser high pressure over the North Atlantic near Greenland. It also shows the low-pressure storm track over the southern U.S. 

  

The pattern will support several snowfall opportunities for the Northeast and Middle Atlantic, we’ve already seeing several coastal storms this fall. So, Miller A and Miller B northeasters could be quite possible during this upcoming winter. While we will most likely see some lake cutters, I don’t think that will be the predominate storm track like we saw last winter.

Given those extremely warm SST in the Atlantic, if we have some cold that drops down from the Arctic, the warm SST could help support a strengthening coastal low. the greater the temperature gradient the stronger the potential of the nor'easter. Depending on the track this setup would also be capable of producing influence of a cold conveyor belt, which would help set up zones of heavier snow. Warm SST's during December can work against big snowstorms, but during the 2nd half of the winter, those warm SST can be a snow lovers’ best friend.

Precipitation Outlook for Winter 2023-24:

Rain, sleet, freezing rain, and snow

Southern and eastern Pennsylvania, Southeast New York State and the Central Hudson Valley, across central New England into southern Maine look to see of generally 10% above average precipitation While Southeast New England, New Jersey, Southeast Pennsylvania, Maryland and Delaware end up generally 20% above average.

The Great Lakes, northwest Pennsylvania and western New York State look to see slightly below average precipitation at -10%

The rest of New York State and northern Vermont, northern New Hampshire and northern Maine ending up with generally average overall precipitation.

 

 

Snowfall Outlook for Winter 2023-24:

These snowfall amounts are overall general ideas for the Northeast and Middle Atlantic for this winter. I base this on the general teleconnection pattern and what I anticipate to be the general storm tracks.

As for how much snow we should expect this winter, well, specific numbers are hard to nail down but with a weak to moderate El Nino in the picture, along with the pattern I describe above, I see support for an above average snowfall season for Southern New England, Southeast New York State (including New York City and Long Island into the Middle Atlantic, With the area around the Appalachian’s ending up as the jackpot, with good odds for well above average snowfall.

Slightly above average snowfall for most of Northern New England into Northwest Massachusetts, Hudson Valley and the Catskills, along with the Twin Tiers of New York State and Pennsylvania, back through most of Western Pennsylvania

Northern and Central New York State and the Adirondacks into Northern Vermont, looks to see near average snowfall. Northwest Pennsylvania away from Lake Erie could also see average snowfall.  

Slightly below average lake effect snows off of Lake Erie. With around average lake snow off of Lake Ontario.

 

A general look month by month:

December:

Temperatures…

Past Thanksgiving into the first week of December is looking to generally be below average, then we should see some warming, resulting in slightly above to above average temperatures up through the time around mid-month, then we look to see general temperatures become slightly below to below average for the end of December.

Overall temperatures should generally end up fairly mild with above average for the month of December.

Snowfall…

For the month I expect generally slightly below average snowfall.

 

January:

January is going to continue to see the up and down temperature roller coaster. The month could start slightly below average. Then there would be the chance for temperatures to warm back up near average to above average, before falling back to average to below average during the 2^nd half of January.

The subtropical jet, will stay active during the month. We could see many of the southern storms head out to sea; but we could see a few of these storms come up the coast. While Western Pennsylvania up through Western New York State, see generally below average snowfall, for Eastern Pennsylvania the rest of New York State into New England see generally average snowfall typically for the month of January.  

 February:

The last half of the winter, is likely going to be colder and snowier than the first half.  February as a whole should see Western parts of the region with slightly below average overall temperatures. The temperatures across Northern into Central New York State and the Northern half of New England, end up with overall temperatures near average, Southern New England, back through Southeast New York State, Eastern Pennsylvania, and the Middle Atlantic should see below average temperatures.

Based on this being an El Nino winter and climatology, February should end up a big snow month. The Southern and Northern jets should stay active. During past El Nino’s, nor’easters are common off the Coast. So, I will be very surprised if we don’t see at least a couple big coastal storms come up the coast, bringing snow across the Eastern half of Pennsylvania, Maryland, Delaware, into New York State along with New England. As we saw during the Super El Nino of 2015-2016, Coastal storms can bring significant snowfall into the Middle Atlantic and Northeast, even during El Nino years.

As far as snowfall, Western New York State, and Western Pennsylvania should generally see slightly above average snowfall With Central into Eastern Pennsylvania and New York State seeing above average snowfall, with possibly well above average snowfall for the Middle Atlantic into Southern and perhaps Eastern New England.  

 March:

Temperatures should be overall above average in the Northeast and Middle Atlantic Region, especially during the 2^nd half of the Month.  With generally below average snowfall across Western Pennsylvania and Western New York State, with average to slightly below average snowfall over Eastern Pennsylvania, Eastern New York State, into the Middle Atlantic and New England.

 Closing thoughts:

.Remember seasonal outlooks are deterministic in nature, so with the overall idea of randomness in mind, different outcomes are always possible. Afterall the law of averages, insist that everything must level out, so these different outputs are expected.

This winter is going to see wild swings between warm and cold temperatures, So snowfall is going to depend on the overall pressure pattern and the timing of the individual storms. So, get ready for a wild ride.  Also with the temperature going back and forth, it will be more difficult to develop a deep snowpack. So while snowfall may indeed end up above average, we might not see long lasting snow banks.  

Well, that’s it

I hope you found this multipart outlook interesting and educational. As always, I can’t answer questions about the outlook from other outlets. But I will always answer all y’all’s questions in regards to my outlooks and forecast.