Winter 2023/24 - Discussions & Forecasts

[SqueakheartLW]

3 hours ago, Chesil View said:

Well done Squeakheart. Brilliant and pretty accurate too.

LOL

Don't you want to have a go at them all and come up with different ones to mine?

[Don]

1 hour ago, Jacob said:

Here are all the cold snaps that CFS is predicting. Jan and Feb appear to have a very strong PV 

Another PV of doom winter?! 

[raz.org.rain]

On 12/10/2023 at 13:08, Jacob said:

Looking at the cfs 850hpa charts, not a single very cold weather event is predicted. Its disappointing but its still too long range to make precise predictions

It would be unusual to go through a winter period with not even a single cold snap. Even the mildest of winters have their colder events surely?

[Jacob]

31 minutes ago, Don said:

Another PV of doom winter?! 

I hope not 

 

Just now, razorgrain said:

It would be unusual to go through a winter period with not even a single cold snap. Even the mildest of winters have their colder events surely?

It still predicted some cold snaps but none of them would have actually been enough to be notable. This was only one run though and a more recent one did predict some decent cold snaps which could be barely enough to produce decent lying snow as far south as the south of England

[Don]

3 hours ago, Jacob said:

I hope not 

I hope not too, but could be the case.....

Hope for the best but expect the worst!

Edited October 13, 2023 by Don

[Jacob]

CFS has predicted some much better cold snaps with the PV being less intense

[Methuselah]

6 minutes ago, Jacob said:

CFS has predicted some much better cold snaps with the PV being less intense

And Admiral Sir Horatio Nelson was my uncle. 

[Jacob]

New CFS run brought 3 cold snaps with the once in December being similar to the beast from the east. Sadly there was often blocking from the south

[Jacob]

18z CFS run predicted a very strong PV in winter with this cold snap being the only severe one

[bluearmy]

Looking at every cfs run for the next six months, day by day, is simply filling your time up.  It’s a model of what winter could bring - there will be runs where there’s nothing notably cold and there will be runs where it shows some pretty cold spells.  However, that really means nothing at this range. 

it’s just for fun as someone often says ! 

[Chesil View]

28 minutes ago, bluearmy said:

Looking at every cfs run for the next six months, day by day, is simply filling your time up.  It’s a model of what winter could bring - there will be runs where there’s nothing notably cold and there will be runs where it shows some pretty cold spells.  However, that really means nothing at this range. 

it’s just for fun as someone often says ! 

Indeed Blue the only time I take any notice of cfs is if it consistently shows the same  cold scenario at a certain period( over a long period of time) whilst chaos reigns before and after and even then pinch of salt is taken.  It did this from months out with the 2018 beast from the east suggesting the period late feb/ early march would be the coldest and snowies spell of the winter but that is one victory in a sea of failures.

Having said that the ECM has shown easterlies at 48 hours in the past with 50 out of 51 ensemble members in favour only for nothing to happen so perhaps we should be too hard on the cfs. 

Edited October 14, 2023 by Chesil View

[Jacob]

42 minutes ago, bluearmy said:

Looking at every cfs run for the next six months, day by day, is simply filling your time up.  It’s a model of what winter could bring - there will be runs where there’s nothing notably cold and there will be runs where it shows some pretty cold spells.  However, that really means nothing at this range. 

it’s just for fun as someone often says ! 

I’m not trying to just look at a single run to make a decision, I’m looking at many to try to see what patterns are forming since in the long range, it’s impossible for it to predict actual weather events but it can predict things like a strong PV, higher chance of a blocking, etc

[DOdo]

Its impossible to predict what winter will be like at this early stage.The way things have panned out. Nothing can be ruled in or out at this early stage with the extremes we have been witnessing. All to play for now

[Frostbite80]

u 60N 10 hPa

WWW.WEATHERISCOOL.COM

Interesting this keeps popping up...if only

[WYorksWeather]

Posting here as well, from the model output thread.

From a cold perspective, SSTs might be starting to look better into early November. These charts start with today's ECM 00z, and step forward five days at a time.

   

General trend towards more near-normal areas in a couple of weeks' time. I still think we're likely to see some moderation though, and especially any direct southerly to south-westerly winds will trend warm.

 

[Bradley in Kent]

Absolutely agree with how one can't predict the weather months ahead. What I will say though is that, just like short to mid-term forecasts, a warm outlook weighs more than cold outlook based on the most recent update. I'm basing this on warmth equaling energy and cold being the lack of energy. A lack of energy will always be beaten by energy in itself. 

Perhaps a similar analogy is light beating darkness which is why there's more daylight and twilight on Earth than true night. 

Not going to write off this winter, simply acknowledging that crisp days, frost and snow will be extra special as such conditions will really be against the background signals, that being El Nino & +IOD duo, strong PV and higher SSTs not to mention the 'warm September/October' omen!

[sebastiaan1973]

Can't find the whole article, but here is the abtract. Adam Scaife. UKMO's finest 

Abstract
This study investigates the interdecadal variation of the Scandinavian (SCA) pattern and corresponding drivers during the boreal winter. It is found that the SCA pattern experiences a prominent regime shift from its negative to positive phase in the early 2000s based on several reanalyses. This interdecadal change contributes to an extensive cooling over Siberia after the early 2000s, revealing its importance for recent variations of climate over Eurasia. The outputs from 35 coupled models within phase 6 of the Coupled Model Intercomparison Project (CMIP6) are also analyzed. The results show that the interdecadal change of the SCA is weak in response to external forcings but can be largely explained by internal variability associated with a change of precipitation over the tropical Atlantic. Further analysis indicates that the enhanced tropical convection induces poleward propagation of Rossby waves and further results in an intensification of geopotential height over the Scandinavian Peninsula during the transition to positive SCA phases. These findings imply a contribution of tropical forcing to the observed interdecadal strengthening of the SCA around the early 2000s and offer an insight into the understanding of future climate change over the Eurasian continent. https://journals.ametsoc.org/view/journals/clim/36/10/JCLI-D-22-0494.1.xml

[sebastiaan1973]

Tweet by Ben Noll.

[Chesil View]

Crikey.  Blocking Highs and easterly winds being mentioned in the meto 15 to 30 day outlook.!!  

[damianslaw]

6 minutes ago, Chesil View said:

Crikey.  Blocking Highs and easterly winds being mentioned in the meto 15 to 30 day outlook.!!  

Surprised they are sticking their neck out like that. It is quite a precarious situation, there is a signal for a southerly tracking jet and deep trough interacting with northern heights, but these could be relatively weak and osscilate from NW to NE..

Easterly outbreaks in November do not necessarily equate to sustained cold weather into Dec. Indeed good examples of where these have broke by Dec, include 1985, 1988, 1993 and 2016.

2010 saw a gradual transition to cold easterlies as the month wore on.

I'd be looking at a perhaps slight variation to the Nov 09 synoptics, with a stronger high to the east positioned further west.. with more of a cyclonic SE flow, just as we have in the days ahead, as a better base state for cold into winter, than a direct easterly. 

Edited October 18, 2023 by damianslaw

[Chesil View]

Indeed Damianslaw. I was very surprised to see such a bullish outlook. Although as you say no guarantee of znything lasting into December even if it does materialise.

Having said that they must be picking up a strong signal to go out on a limb like this when a lot of the time they simply quote average climatology for the extended period of the forecast.

[Jacob]

11 minutes ago, Chesil View said:

Crikey.  Blocking Highs and easterly winds being mentioned in the meto 15 to 30 day outlook.!!  

Maybe a chance for some early snow I hope. Over here in the SE it’s rare to find snow before January

[swebby]

On 16/10/2023 at 20:40, WYorksWeather said:

Posting here as well, from the model output thread.

From a cold perspective, SSTs might be starting to look better into early November. These charts start with today's ECM 00z, and step forward five days at a time.

   

General trend towards more near-normal areas in a couple of weeks' time. I still think we're likely to see some moderation though, and especially any direct southerly to south-westerly winds will trend warm.

 

Looking at the central med - Does anyone know if abnormally warm sea surface temperatures would be conducive for high pressure, or low pressure, to form around Italy?  Low pressure over Italy normally being a key ingredient for an easterly in NW Europe.

[summer blizzard]

6 hours ago, Chesil View said:

Crikey.  Blocking Highs and easterly winds being mentioned in the meto 15 to 30 day outlook.!!  

Interesting. 

That suggests that there is strong support in the long range Euro ensembles and Glosea.

[Rain All Night]

51 minutes ago, summer blizzard said:

Interesting. 

That suggests that there is strong support in the long range Euro ensembles and Glosea.

These were (and for us public still are) the latest EC46 anomalies for the week 6-13 Nov at the time they wrote that forecast (with the range of that MetO forecast having been out to 15 Nov when it was first published yesterday; the wording has been kept today) - you can see how they might have got the impression that there could be easterlies: