Winter 2022-23 - General Discussion

sryanbruen

We have only began meteorological autumn. It is the 11th of September when I am writing this post. Often times this time of year, the thoughts turn towards winter. There has already been a lot of talk on other forums such as Netweather. With energy prices exponentially on the rise, the likelihood of whether 2022-23 will be a cold winter will hold greater than normal chance to be discussed I am sure. As a weather enthusiast and weather photographer, I long for extreme weather events whether be it windstorms, snowfalls, severe frost. However, when writing my winter thoughts, I try and leave bias aside.

Ireland's last genuine cold winter was back in 2010-11 when we had the coldest December on record and likely the coldest month in Ireland since January 1881. 2017-18 and 2020-21 were cold by modern winter climate whilst 2012-13 and 2014-15 were average. Most winters, as to be expected in a temperate oceanic climate like Ireland has, have been mild since 2010-11. We've had some exceptional mild ones, 2018-19 was our all-time mildest on record. 2021-22, 2016-17 and 2011-12 were also up with the mildest. These four exceptionally mild winters were noted also for their anticyclonic nature which is unusual for having such a mild winter though not unprecedented - 1974-75 and 1988-89 also were exceptionally mild and had a lot of ridging from the Azores more akin to summer. On the other side, we've also had notable stormy winters in 2013-14, 2015-16 and 2019-20; to a lesser extent 2014-15 too.

2021-22, the most recent winter season, had a lot going for it from a cold perspective. The exceptional mild autumn pattern of 2021 raised some eyebrows however. The early significant stratospheric warming through October, history has told us this doesn't necessarily translate to a weak stratospheric polar vortex through the succeeding winter and in fact the opposite as PV disruption events cut off wave activity and late autumn is a cooling time of year so this only allowed radiative cooling to intensify and lead to a strong stratospheric polar vortex through the winter which never receded. This was even more the case in the infamous mild and dry winter of 2016-17 which started off with an exceptionally weak SPV through November 2016 but quickly became stronger through December. There was a cold end to November 2021 that brought lowland snowfall to parts of the UK but Ireland was on the periphery and there was a cool start to December. It was looking positive for cold lovers at this point as unlike 2020-21, Siberia was greatly colder this time around and NE Europe had a lot of cold residue with one of their coldest starts to December in a long time. There was a milder spell mid-December with anticyclonic gloom then pre-Christmas there was famously a lot of talk about the first white Christmas since 2010 (or 2004/09 if you want to be technical) with Greenland blocking possibly getting going. In fact, the NAO did indeed go negative for a short period from the 20th to 24th December 2021. This was the first time we've seen -NAO at this time of year since 2010. However, something went very wrong in the atmosphere that remains a mystery and the blocking went kaput with low pressure successfully undercutting it from the south which would result in a deluge Christmas. At this time there was a massive spike in sunspot numbers on the sun, the biggest so far seen in solar cycle 25 up to that point which has been used as a blame for Christmas 2021 going wrong for coldies. I don't buy that direct attribution however and that it was pure coincidence. Then after that we seen the mildest New Year on record with record-breaking mild southwesterly winds drawing up tropical maritime air from notably warm seas. At this point, it seemed like all bets were off for cold and snow with only the long range GFS showing cold, blocked charts most of the time. La Niña favoured a mild, zonal February and that was indeed what we got. So was 2021-22 the biggest fail ever for a winter season? I don't think so. I think 2018-19 was bigger. In 2018-19, there was a big model consensus for a -NAO dominated winter which was theorised to because of expecting a massive sudden stratospheric warming event in Dec/Jan which did happen but the effects did not project onto the NAO and the Met Office did consistently hint at cold conditions which apart from late January just never happened. In 2021-22, there wasn't that same seasonal model consensus and the Met Office forecast was strongly for a mild winter.

With that generic introduction and recent history perspective out of the way, here's what I think based on current modelling and teleconnections or drivers.

For 2022-23, these are how the usual teleconnections/drivers look from an early view:

• QBO is in its mature westerly phase. This is said to decrease the likelihood of a major mid-winter sudden stratospheric warming occurring and lead to an intensified North Atlantic jet stream. Therefore, increase the chance of a mild winter.
• The North Atlantic Ocean is in an unprecedented warm state. The sea surface temperatures are off the scale near Newfoundland. Warm sea temperature anomalies around here historically do not correlate well with a cold winter in western Europe. Back to at least 1951, the North Atlantic hasn't been warmer than it is now. A general warm North Atlantic in winter time is more conducive to a weakened North Atlantic jet stream with less of a contrast between the tropics and the arctic. However, any westerly winds will be greatly milder than normal and polar maritime northwesterlies will be highly modified compared to usual. The warm SST anomalies also allow Atlantic tropical cyclones to hold tropical status for longer further north.
• The ENSO region in the central Pacific Ocean is in a developing La Niña phase. The modelling suggests this will reach moderate status by November. Currently it is in weak status with the recent week returning an anomaly of -0.8C in region 3.4. La Niña is said to favour front-loaded winters in Europe with negative NAO early on through November, perhaps December and positive NAO later with a mild February. This is especially true for stronger events, less so for weak events. This will be the third consecutive La Niña winter in a row, 2020-21 and 2021-22 both had moderate La Niña events too. The La Niña is currently more central based than eastern based - whether the event is central Pacific based (CP) or east Pacific based (EP) has been shown to have significantly different effects. An east based La Niña is more conducive to a cold winter than central based. There are also mixed events which are far rarer and the sample size is too small to come to any conclusion or to theorise.
• The 2022 Atlantic hurricane season has been notably calm to date and is highly unusual for La Niña. The Saharan dust layer this year has been strong and has been the prime reason for calm activity. August 2022 was the first August without a single named Atlantic tropical storm since 1997 and is the first known occurrence that has occurred during a developing La Niña, the other occasions were El Niño or ENSO neutral. September has so far seen a few named storms but the season remains firmly inactive on what is expected as of this point in the year. Active hurricane seasons are said to increase the chances of a cold winter but this theory like most others has mixed results at best and there are plenty exceptions - the last inactive hurricane season was back in 2015 and each hurricane season since has been active yet there has been no genuine cold winter in that time. 2009 was an inactive season and was succeeded by the coldest winter since 1978-79.
• The Indian Ocean Dipole is in its negative phase. Therefore, there is little chance of a repeat performance of 2019-20 when autumn 2019 had an anomalously positive IOD phase and this resulted in little wave activity to disturb the stratospheric polar vortex from intensifying. 2019-20 was therefore infamously called the 'Polar Vortex of Doom' winter with Europe having one of its mildest on record and for Ireland, a very wet stormy one and notably so in February 2020. However, that is irrelevant to this year because the opposite has happened.
• Solar cycle 25 is nearing its solar maximum phase which is expected to occur around 2024-25. The solar minimum occurred in December 2019. Solar maximum winters are associated with mild, zonal winters whilst cold winters are said to happen around or just after minimum. 2020-21 had a vast amount of high latitude blocking but it was never in the best position to send severe cold weather directly towards Ireland and was a near miss. Apart from that, the winters around solar minimum of 24/25 have been mild to very mild. This is a big contrast to what happened in the prior solar minimum. Blocking position is of vital importance! Ireland is one tiny part of a big world.

As you'd expect from posting early, the drivers are mixed and don't provide much to base thoughts off of. On the whole, I would lean towards a mild winter and not because of the fact that mild winters are just our norm anyway. The record mild North Atlantic even though it could lead to a weakened jet stream means any westerlies we would get would be significantly milder than they are already. Another Azores or Euro high dominated winter like 2021-22 would be exceptionally mild again and would completely overthrow any colder shots from the north or the east in the overall seasonal means. Would need a genuine strong Griceland block in my opinion to lessen the impacts of the mild Atlantic. If we are to see any cold weather, it would be early on in the season to go along with what you'd expect with a La Niña.

See how these thoughts evolve over time. Will they age poorly? How much will they change?

Thank you for reading.

mcburns07

Mild anomalies to continue so? At some point surely this run of above average months will end. Currently stands at 16 months in a row at my local station Roches Point. Only 11 months below average in the last 57 months 😬.

esposito

I have very low expectations for winter 2022/2023. I expect a fairly mild one for Ireland. With heating bills going through the roof over the coming months many people will be delighted with another mild winter.

P.S Hope I’m wrong and we do actually get a colder than average winter with decent snow amounts.

Cluedo Monopoly

Yeah I'd normally love copious amounts of snow but given the energy bills, I will happily take a mild winter. Mild and dry ideally.

mr.stonewall

Very simple, I think. WET.

Oneiric 3

As has been noted on US weather sites, there has been a substitutional lack of the 'southern Pacific Jetstream'. over the last 18 months or so, and this trend is expected to continue this coming winter. From what I can see, the lack of this driver allows high pressure cells to form more readily form over the central and southern states, which in turn move eastwards to feed and amplifiy the Azores high influence on this side of the Atlantic. In other words, a dreaded repeat of last winter's dominant pattern seems likely in my opinion, which was continually warm, cloudy, calm, dry and just generally a chore to live through from a weather enthusiats persepctive.

Billcarson

Think another mild boring winter is likely, no matter what the teleconnections are these days it nearly always ends up the same mild story. Perhaps with such warm temperatures in the Atlantic that could promote high pressure in the Mid-atlantic? Mid Atlantic high pressures or ridges could give some cold snaps if positioned right. That's my main hope.

Niall145

I have zero expectations for this winter, absolutely zilch. Last 'winter' was just an absolute trainwreck (including the worst Christmas day in living memory), literally the only highlight of the entire season was seeing some snow in the Dublin/Wicklow mountains in the first week of January. Anyway who knows, maybe we'll get something slightly more seasonal this year; even one day of snow (or even a hard frost!) would be a bonus in our crap climate.

pauldry

Do we even have a Winter anymore. Apart from long dark nights temperatures of 11 to 13c most days isn't really Winter.

However the weather always surprises and my only hope that this Winter might be different is that A. The hurricane season has been quiet so maybe a different pattern emerges for Winter and B. Above average Arctic sea ice so maybe that equates to something colder for Winter. However little can be attached to these just that they are differences from previous years.

sryanbruen

https://www.boards.ie/discussion/comment/119603853#Comment_119603853

Yeah I note similar and with one of the likely driving forces of that (La Niña) set to continue for yet another year, is there anything that will drive the atmosphere out of this hell hole? No, probably not unless the stratosphere throws some surprises.

I'm sure the average Joe will be delighted at the thoughts of a calm, dry and mild winter but I have to wonder, would the lack of wind from such a winter even be good for energy prices? However, the weather will do what it pleases regardless.

mcburns07

Feels like we’re due some storms this winter. Been few and far between lately.

Gonzo

This winter is likely to be either mild or exceptinally mild winter. Maybe we might get lucky and get one cold day with snow showers in an overall mild winter. With the fuel bills through the roof I think most people will be happy with a very mild winter as long as it isn't overly wet or stormy.

Billcarson

I suppose we have to see how the autumn pans out. I thought it was pretty obvious after last autumn that last winter was going to be a complete dud. If during this autumn we can break out of these above average months it may give a bit of hope. Not suggesting a cold autumn would mean a cold winter but surely a better chance then compared to last autumn.

esposito

Jaysus we’re all so negative (me included) but you can’t blame us as most of our ‘Winters’ in the last 11 years have been rubbish (except for 2017/18). 2020/21 wasn’t too bad I guess with that Ice day in December but still very little snow.

mcburns07

Yep lot of negativity. Not sure why, long range forecasting is rarely right…. And teleconnections make fools out of forecasters time and time again.

sryanbruen

Probably means nothing, especially at this point in the year but I found it interesting how the ECM, CFSv2 and CMCC are all singing from the same hymn sheet with a mid-Atlantic ridge pattern for January 2023. Perhaps a reaction to the very warm North Atlantic SSTs? I'm only speculating here.

The ECM for December 2022 is notably blocked with the strongest positive anomaly over Iceland and low heights over Iberia. Would be pretty horrific for the energy bills as cold and dry conditions would be dominant.

Meanwhile the UK Met Glosea6 shows a zonal pattern with troughing over the country and positive heights over eastern Europe. Would be mild and wet.

Slightly off topic but a highly unusual September hemispheric pattern to date (anomaly is to the 10th) with well above average z500 over Greenland and a trough to the southwest of Ireland. Whilst it hasn't been cool at all, this is a clear -NAO signature. I don't recall too many years with a September pattern like this. In fact, September is one of the months I expect +NAO most likely to occur. Nothing like September 2021.

Darwin

Thanks for the great writeup Syran. Another variable to throw into the mix is the eruption of the Hunga-Tonga-Hunga-Ha’apai volcano (Southern Pacific) on 15 January 2022 and is thought to have had a cooling effect on the Southern Hemisphere. As I understand it, this eruption was significantly larger than Pinatubo in 1992 which had an impact on weather for many years afterwards. The Pinatubo eruption composed of dust and sulphur compounds, while the Tonga volcano was mostly water. Is the quieter than normal hurricane season linked to this event and will it have a knock-on effect on the Northern hemisphere winter?

Danno

Interesting thoughts @sryanbruen lots of mixed signals there. I suppose on balance of all the signals you discussed in the OP there are subtle hints of central to northern Atlantic blocking and a generally slow moving atmosphere overall.

Given the warm SSTs over the north Atlantic, I would not like to see central Atlantic blocking set up. Toppler lows with a dreaded warm sector turning potential snow to sleet is the greatest buzzkill for those who enjoy a proper snowy winter. Nothing worse than 2c days and dripping sleet. I think it was winter 2002 or 2003 that had a good few northwesterly lows that gave sleet time and time again.

A north Atlantic blocking dominated winter would be very interesting, with those aforementioned warm SSTs, lows undercutting would have alot of moisture embedded and hitting that cold air could translate to a very snowy winter.

Lots of interesting pieces with the jigsaw to be put together and we truly won't know the picture 'till well into March.

Danno

https://www.boards.ie/discussion/comment/119615167#Comment_119615167

Hard to say really. 2017-18 was the snowiest winter I remember living through in Ireland and I'm no spring chicken either. The snow in January 2021 while not overly deep, it stuck around for a few days - and probably was the last notable snowfall, at least in these parts.

pauldry

In Sligo we generally get 1 to 3 snowy mornings each Winter but again I think the period to Christmas is going to be relatively quiet and mild. The new year might bring more storminess and 1 or 2 of those snowy mornings in between.

Elmer Blooker

I like extremes in our tedious climate, northern blocking with lying snow and blue skies is my preference. This is unlikely as northern blocking in Dec, Jan and Feb seems very unlikely in our 21st century climate (who knows what caused Dec ‘10, I don’t believe a solar minimum causes cold winters anymore like I used to)

My second preference would be for a Euro high giving dry weather with 14/15c by day and all windows in the house open in a balmy southerly and those lovely lenticulars over the hills. February 1998 is a good example, anything is better than wet and windy.

a typical chart from Feb 1998, winter 88/89 was similar.

PokeHerKing

I'm going to be positive and say we'll get a belter of a winter. Maybe not 2010 but above average cold/snow wise.

Nothing scientific to it but we're currently experiencing lots of 'once in a generation' type events so I'm going to throw winter 2022/23 onto the pile.

Gonzo

https://www.boards.ie/discussion/comment/119620864#Comment_119620864

I completely agree if we don't get a cold and snowy winter the next best thing is a dry and very mild winter. Nothing worse than week after week of mild but feels cold, blustery Atlantic conveyer belt of rain, deluges, showers and mist/drizzle.

mr.stonewall

https://www.boards.ie/discussion/comment/119621291#Comment_119621291

We have to take the heavy stuff off the Atlantic at some time during the year. My preference is to take it in the winter and increase the odds for better in the year

Danno

https://www.boards.ie/discussion/comment/119621675#Comment_119621675

November is the time and place for the Atlantic onslaught in my opinion, after that it can go to Spain for winter and Iceland for summer.

mr.stonewall

https://www.boards.ie/discussion/comment/119625251#Comment_119625251

Very thoughtful, share the love

Oneiric 3

What I expect the bulk of this coming winter to look like on the charts:

I really, really want to be wrong.

[Deleted User]

https://www.boards.ie/discussion/comment/119627307#Comment_119627307

Sadly that set up seems to becoming more common. Absolute borefest.

Gonzo

That setup is great for late Spring, all of summer and early Autumn but yeah it's terrible if it persists into the winter and through to early Spring.

sryanbruen

I made the graphic below to help visualise the difference in NAO and European winter pattern tendency between eastern based La Niña events and central based La Niña events for the period November to February that I briefly touched upon. The reanalysis all but confirms it. Note the caveat with these analogs is they do not take into account the strength of the events.

There is a tendency for -NAO in November for both events with somewhat of a mid-Atlantic ridge through December but the -NAO signal lessens a lot, especially in central based years. The real big differences come in January and February.

In eastern based years, there is a tendency for blocking in the high latitudes in both months - towards northern Scandinavia in January and over Iceland in February possibly indicating retrogression as the season goes on. In fact if you look closely, the retrogression starts as soon as December with positive heights near the Urals. This would give the possibility of a mid-winter major sudden stratospheric warming that could possibly result in such a blocked late winter period even though it's Niña (think of 2017-18 as a good example).

Meanwhile, in central based years, there is a strong signal for a +NAO through January with a deep Icelandic Low. The +NAO signal continues through February but with more high pressure around and possibly the risk of severe cold easterlies for central and southern Europe as in February 2012 which was indeed during a CP Niña. A mild and dry signal for Ireland largely in those Februaries.

Here's how the current oceans look on 15th September 2022. The coldest of the SST anomalies in the central Pacific have become more eastern based in regions 1-3. This is a change on what this La Niña has so far developed. Will it stay that way? Who knows. Plenty of time to change and I think we will see further variation.

The seas remain much warmer than average around Newfoundland but there has been a definite cooling from the unprecedented warm levels they had been seeing the past 2 months. The warmest of the anomalies seem to be migrating a bit further northward towards Greenland as well. There was an interesting point brought up around long range modelling continuously raising heights where these SST anomalies are warmest in the North Atlantic. More evidence perhaps of the theory I gave that maybe modelling (including some of the seasonals for winter) are reacting to the SSTs?

Lots to keep a watch on.

Danno

https://www.boards.ie/discussion/comment/119628030#Comment_119628030

Good research there @sryanbruen - alot of moving parts. Would it be fair, even optimistic to say at this early stage that a steamroller Atlantic based winter is unlikely?