Winter 2023/24 - A Post Mortem

[TillyS]

2 hours ago, Continental Climate said:

in the mad thread

 

[sorepaw1]

I found GFS to be very good this Winter just my opinion.  I suppose we'll have another 9 or so months till I'm back in here , joining the chase.

Take care everyone hope we have a hot summer . 

See you late November 24.

[Don]

2 hours ago, sorepaw1 said:

See you late November 24.

Probably another waste of time if you're looking for 'proper' winter weather, but you never know.....

[TillyS]

2 hours ago, sorepaw1 said:

I found GFS to be very good this Winter just my opinion

I agree with you. In my opinion it has been the standout leading model.

I’m beginning to feel that teleconnections, apart from AGW, are little more, for UK forecasting, than magicians’ misdirection.

[Don]

4 hours ago, Continental Climate said:

I really have no idea where we will be in 30 years time but if things keep going as they are, well we are in serious trouble. 

We are in serious trouble full stop with the way the world's going!

[SqueakheartLW]

 kold weather

23 hours ago, Don said:

I'm beginning to think we maybe starting to see a similar kick upwards into the 10.8-11.4c range where we basically won't deviate far from that bar the odd freak cold month relative to the mean that might still happen at times (see Dec 10, or to a lesser extent Mar 13).

 Don

I wouldn't rule it out again as 2024 is already provisionally warmer than both 2022 and 2023, the other 11C CET years on the record and we are also above 2014 as well at this stage.

Edited February 27 by SqueakheartLW

[Don]

 SqueakheartLW most certainly can’t rule out 2024 being another 11C year indeed!

[Man With Beard]

Having had a "busy" life period recently I've been away from the forum for a while, and so I've just been catching up ... great thread!

I think one thing to add (probably has been but I'm only on page 2) ... I think there's a lack of appreciation that global signals are very difficult to correlate to "is it going to snow north or south of the M4"?

Global signals are only every starting point relating to a general area of the globe. They're never a guarantee of the end result for a specific location.

I hear Scandinavia has experienced a very cold winter. Doesn't that suggest it could have been us but for a little tweaking? 

As much as science feels as if it should be perfect, and there's a craving for solutions as perfect as maths, we're just not there yet when it comes to scientific explanation, whether meteorology, or other stuff like the origins of the human race.

[Penrith Snow]

I never expected anything from this winter due to the strong El Nino, I am more hopeful of winter 2024/25 with a moderate La Nina.

What I won't be doing is chasing the MJO and other Snake Oil solutions.

If we stick to synoptic meteorology up to 168 hours our lives will be far less stressful.

Andy

[Downburst]

Still not explanation as to why this absolutely crazy global sea temp anomaly is ongoing. I'm keeping an eye out for explanations and from what I can see there is no solid explanation, a "freak" event. 

https://www.pbs.org/newshour/science/sea-ice-lows-extreme-ocean-heat-of-2023-offers-glimpse-of-future-warming-study-says

[swebby]

 Downburst

Just some considerations -

First, obviously we are currently in an el Nino phase that started back in June last year - the point that orange line really begins to diverge from the norm.

Second, The article talks about abnormally high North atlantic sea surface temperatures.  I note that it was a relatively quiet hurricane season in the Atlantic basin with many of the emerging storms in the East Atlantic getting battered by wind shear and not amounting to much.  So the overturn of the sea surface and the huge amounts of energy from the sea that these large hurricanes normally suck up never really occurred.

No idea if these are the reasons, even if they are, that graph is rather alarming.

[damianslaw]

I'll be looking for a very mild end to Nov, start to Dec with rampant zonal winds and PV, for promise of cold next season. Early cold before christmas since 2019 with exception of 2020 has been a bad omen for cold thereafter. I always feel the synoptics and state of play around christmas gives clues how rest of winter may pan out, cold outbreaks a good omen, locked in mild not so.. case in point late Dec 14, 17 and 20 brought a degree of cold and snow, followed by average or cold rest of winter. All others since 2013, not so.. 

Edited February 28 by damianslaw

[Daniel*]

10 hours ago, Downburst said:

Still not explanation as to why this absolutely crazy global sea temp anomaly is ongoing. I'm keeping an eye out for explanations and from what I can see there is no solid explanation, a "freak" event. 

Strong El Niño that’s your explanation on top of GW, the long duration La Niña accumulated a lot of heat in places… El Niño will die in coming weeks/months. Oceans will be cooler late 2024 with La Niña returning.

Edited February 28 by Daniel*

[Don]

 Daniel* that anomaly is a real eye opener though, even taking into account a strong El Nino and GW, which is rather worrying!

[cheeky_monkey]

 Don if you look at the last ElNino event of 2016 the global sea temp is only 0.1c warmer than it was then... be interesting to see if there is a similar drop off in SSTs this year as there was in 2016 

[al78]

 swebby I disagree 2023 was a relatively quiet hurricane season, it was the most active hurricane season since reliable records began for a moderate to strong El Nino season. The extremely warm tropical Atlantic SSTs offset the normally high vertical wind shear associated with El Nino events (by that I mean those SSTs acted to perturb the Walker circulation in the opposite manner to which an El Nino does).

[Don]

 cheeky_monkey

That doesn't appear to be apparent on the chart though?

[cheeky_monkey]

 Don the scale is in very small increments thats why.

[Catacol]

On 27/02/2024 at 10:43, TillyS said:

I agree with you. In my opinion it has been the standout leading model.

I’m beginning to feel that teleconnections, apart from AGW, are little more, for UK forecasting, than magicians’ misdirection.

For all the correct talk of climate change impact on our weather, this needs picking up. An understanding of windflows - whether impacted or not by CC - is only a "misdirection" when it is not understood. You would do well to look at the two cold snaps we did manage to get out of this year's winter and ask yourself the question as to where they came from. The point is - teleconnections will not always deliver, and perhaps are becoming less likely to deliver for the UK, but without them you have no chance at all of reversing westerly dominance. Ignorance is not an excuse for making an assertion like this that fundamentally undermines the steps forward that have been made in understanding what drives our weather.

This winter the stratosphere dealt us a blow and reminded all that momentum and wave action originating from the Pacific is not always destined to put a high lat block in place in the Atlantic sector especially when the strat is not in sympathy. The biggest single factor that shredded the second half of winter was the failed SSW in early January and what transpired afterwards. I am sure the real strat grogs will come up with an analysis as to what reversed that very optimistic position at New Year.

And AGW is not a teleconnection. It is a background constant against which everything is operating. There is less cold air, there is more warm ocean. A constant, not a driver.

Finally, you have pushed the GFS agenda all winter but the stats do not support this. We are now able to look at EPS alongside GEFS and GEPS and the Euro model continues to be the go to, with UKMO close behind. Check the stats, they do not lie. There may be a case to argue that over Greenland all models substantially struggle and the GFS is no worse than the others at interpreting data in that area, but once we get to lower latitudes GFS is less accurate. Do not be fooled by the fact we see 4 GFS compared to 2 of the others each day and equate occasional identification of a future pattern in the 06z or 18z as being the same as being "better".

Edited March 2 by Catacol

[bluearmy]

 Catacol the gfs will invariably return to climatology as week 2 progresses 

hence it will invariably predict the demise of a cold spell first 

if there is only one horse in the race then you’d expect it to win 

I have been more impressed with gfs’s forecasting in the upper strat this year than previous. I have also been taken by its performance lower down in the trop in the 144/192 period but I think that could be on the basis that I expected less from it !

would like to see an NH anomoly chart for feb. I expected a frustrating month  with good patterns too far north for the U.K. but the AO going + post 18th was a surprise to most. 

the AO/NAO solidly negative from the 4th to the 18th and then solidly positive which wasn’t forecast more than a week or so ahead. (Which we’d expect the ens to get right).  Was that a reaction to the reflected reversal? 

 

[Metwatch]

15 minutes ago, bluearmy said:

would like to see an NH anomoly chart for feb. I expected a frustrating month  with good patterns too far north for the U.K. but the AO going + post 18th was a surprise to most. 

[bluearmy]

 Metwatch high anomoly to the west as forecast by most models. But too far west as some mused. 
high anomoly over Barents which did us no favours. Low anomoly to our north was useless because it couldn’t get further east and more importantly, the high euro anomoly delivered a very mild month.  Take out the euro anom and we could have had some fun.  That may end up on most of our gravestones!

[summer blizzard]

 Metwatch

Canadian High further east than normal, we might have had more U.K. or Scandi blocking if we had a normal Nino +PNA and Alaskan Low. Likewise, second anomaly with high over Russia results in a cyclone near Greenland and a trough near us. 
 

A broadly unkind winter.

[North-Easterly Blast]

 Metwatch Out of interest, as well as for February, are you able to post a pressure anomaly chart for the whole of winter 2023-24 (December to February period) ?  

[Metwatch]

10 minutes ago, North-Easterly Blast said:

pressure anomaly chart for the whole of winter 2023-24

Sure, link to create them for any other periods here: https://psl.noaa.gov/data/composites/day/

Settings: (sea level pressure plot is also possible to do in the variable tab which shows similar)

Result: (rotated clockwise for easier viewing)

Edited March 3 by Metwatch