Early run up to Winter 2020/2021 discussion

[SMU]

10 hours ago, SLEETY said:

That's about the only time the met office forecast of HLB actually came off in 2010,other times when they forecast it the opposite happened. So don't get this idea they are always accurate when they forecast HLB during the winter months. They are WRONG most the time regarding long_range 

A Computer doesn't actually make the weather remember

2009 & 2010 was forecast. Both had substantial Blocking. so they were both correct. 

The glosea November smoothed forecasts for DJF have been remarkably accurate, dont confuse these forecasts with the EC46.

[feb1991blizzard]

8 minutes ago, Steve Murr said:

2009 & 2010 was forecast. Both had substantial Blocking. so they were both correct. 

The glosea November smoothed forecasts for DJF have been remarkably accurate, dont confuse these forecasts with the EC46.

Also must point out that the smoothed CFS forecasts in November when showing zonal for December have rarely been wrong.

[Yarmy]

Don't know what everyone's worried about. Looks alright to me:

[sebastiaan1973]

Glosea5 shows a CP La Nina, which teleconnects with a positive NAO.

Central Pacific (CP) La Nina (Modoki)
The SST anomaly center associated with the CP La Niña is shifted westward into the CP west of 150°W and small cooling SST anomaly is found over the EP". In contrast to the canonical EP event, which advances somewhat westward to as much as 150longitude and decays faster, the CP event decays more slowly and remains in place, while propagating only a small amount in either direction". These differences in zonal location of SST anomaly and their evolutions suggest the possibility of different underlying dynamics, which is indeed the case. Modoki la nina are largely the product of a local air-sea interaction that develops and decays in place over the central Pacific. The reduced cooling over the east may also be further attenuated by a modified Walker cycle, according to Zhang, which features a displacement to the west of the easterly trades responsible for upwelling. In the modoki la nina, the EP trades are replaced with an anticyclone, as a direct result of the cool SST anomalies being shifted west to the CP.

The EP and WP [Pacific] forcing associated with the "modoki" la nina generally features an inverse pattern from that of a modoki el nino across North America. This resultant N. American pattern is more akin to an east-based, canonical el nino. however, we obviously have the prominent Aleutian high as opposed to the Aleutian low during el nino due to opposite anomalies over the tropical Pacific. The Aleutian high is in this composite is appreciably flatter and displaced to the southeast in relation to its canonical counterpart, as alluded to.

[Simon M]

I give up.  No cold weather this winter then, just the same mild, Atlantic dross.  The "ever-changing British weather" is an absolute joke when you can forecast the coming three-months' worth of mild, wet windy rubbish.

 

See you around folks.  I'll probably come back in Spring when the "winter" is out the way.

[TSNWK]

12 minutes ago, Simon M said:

I give up.  No cold weather this winter then, just the same mild, Atlantic dross.  The "ever-changing British weather" is an absolute joke when you can forecast the coming three-months' worth of mild, wet windy rubbish.

 

See you around folks.  I'll probably come back in Spring when the "winter" is out the way.

Nice try.. but 1st WIO post was last week.. can we make October next year

[swfc]

16 minutes ago, Simon M said:

I give up.  No cold weather this winter then, just the same mild, Atlantic dross.  The "ever-changing British weather" is an absolute joke when you can forecast the coming three-months' worth of mild, wet windy rubbish.

 

See you around folks.  I'll probably come back in Spring when the "winter" is out the way.

I wouldn't bite the bullet yet mate. Looking at the professional output it's not looking great but it's weather. It does what it wants so it's capable of many suprises

[TSNWK]

Agree so much.  Its part of the fun, the chase the moments when it lands 2009 10 18 and the fails of which there are many..

Buckle up I say and let's enjoy the ride.. 

[Don]

15 hours ago, CreweCold said:

It also doesn't preclude the occasional polar NW'ly, but in the main, it's pretty bad for S UK.

If it's bad for southern UK, I think it's only fair you should eat that sock! 

Very disappointing indeed but we should perhaps be used to it now!

[Chesil View]

I think Steve Murr's reverse psychology trick has worked No sooner does he post GLOSEA showing wall to wall Positive NAO/PV driven mush all winter than the nwp models start to show mid Atlantic ridges and Greenland highs as Meteorological winter is about to start..

[Eagle Eye]

1 minute ago, Broadmayne blizzard said:

I think Steve Murr's reverse psychology trick has worked No sooner does he post GLOSEA showing wall to wall Positive NAO/PV driven mush all winter than the nwp models start to show mid Atlantic ridges and Greenland highs as Meteorological winter is about to start..

See that's what the bbc does reverse phychology

[SLEETY]

As if you will get exactly what glosea is showing for 3 months in a row.The skill woud be if they could pick up when a cold spell would occur  in advance,only 2010 comes to mind,countless others they never predicted.

 

Pointless thinking they can forecast the next 3 months ,as is writing off the whole 3 months of winter on 12th November

[Weather Enthusiast91]

6 hours ago, Simon M said:

I give up.  No cold weather this winter then, just the same mild, Atlantic dross.  The "ever-changing British weather" is an absolute joke when you can forecast the coming three-months' worth of mild, wet windy rubbish.

 

See you around folks.  I'll probably come back in Spring when the "winter" is out the way.

I want a good winter just as much as you do. But don't give up so easily.  

Remember that even the most experienced weather forecaster cannot accurately predict the weather any more than a couple of days in advance. As far as autumn itself goes, it has been very monotonous indeed but that doesn't necessarily mean that winter will end up being the same way. I must admit, I am not holding my breath but nobody knows how winter will pan out. Anything could happen. We shall have to wait and see.
 

I can remember back in the spring of 2013 I thought we were heading for a poor summer. Yet look at how that turned out.

Edited November 12, 2020 by Weather Enthusiast91

[Tim Bland]

7 hours ago, Simon M said:

I give up.  No cold weather this winter then, just the same mild, Atlantic dross.  The "ever-changing British weather" is an absolute joke when you can forecast the coming three-months' worth of mild, wet windy rubbish.

 

See you around folks.  I'll probably come back in Spring when the "winter" is out the way.

Thanks for coming Simon, close the door on your way out ?
 

Geez was that really a winter is over post, he only joined on 27th October...let’s hope he has a bit more stamina next year and actually makes it to winter 

Edited November 12, 2020 by Tim Bland

[Wilxy]

7 hours ago, Simon M said:

I give up.  No cold weather this winter then, just the same mild, Atlantic dross.  The "ever-changing British weather" is an absolute joke when you can forecast the coming three-months' worth of mild, wet windy rubbish.

 

See you around folks.  I'll probably come back in Spring when the "winter" is out the way.

3 Posts and the 3rd one is the "Winter is over" classic! 

[mulzy]

This morning’s ECMWF sub seasonal shows a little promise with some higher heights to the north west in weeks 4 and 5 - albeit the signal being weak.

[NorthYorkMoorsSnow]

You’d think it was the end of winter looking at some posts on here. It will be what it will be. There’s plenty of months for a cold spell to occur as others have said these can crop up out of nowhere. Here’s hoping for a white Christmas  

[virtualsphere]

10 hours ago, sebastiaan1973 said:

Glosea5 shows a CP La Nina, which teleconnects with a positive NAO.

Central Pacific (CP) La Nina (Modoki)
The SST anomaly center associated with the CP La Niña is shifted westward into the CP west of 150°W and small cooling SST anomaly is found over the EP". In contrast to the canonical EP event, which advances somewhat westward to as much as 150longitude and decays faster, the CP event decays more slowly and remains in place, while propagating only a small amount in either direction". These differences in zonal location of SST anomaly and their evolutions suggest the possibility of different underlying dynamics, which is indeed the case. Modoki la nina are largely the product of a local air-sea interaction that develops and decays in place over the central Pacific. The reduced cooling over the east may also be further attenuated by a modified Walker cycle, according to Zhang, which features a displacement to the west of the easterly trades responsible for upwelling. In the modoki la nina, the EP trades are replaced with an anticyclone, as a direct result of the cool SST anomalies being shifted west to the CP.

Not disputing this, but thought I'd have a look at the data in relation to difference between ENSO regions 1+2 and 3.4 in Nina winters and what that means for the CET.  In this chart anything below the horizontal 0 line has a greater negative anomaly in the 3.4 region for Dec - Feb; anything above has a greater negative anomaly in the 1+2 region.  The further below / above the line, the greater the difference.  We should see CP La Ninas below the line and there are still quite a few colder examples, including in more recent years 2010-11 and 2008-09.  There are also some very warm ones of course like 1988-89, and the extremes do trend warmer, but it shows that anything's still possible in this setup.

  

[Roger J Smith]

There can never be a reliable "winter is over" signal in November. Pessimism to mid-season is perhaps valid in some cases but never past let's say mid-January as shown in 1946-47 (very mild start to Nov 1946 which at 8.1 was one of four tied 24th warmest). That said, top 23 November CET values have only seen the following results:

Rank ___ Year ___ CET Nov __ Dec __  Jan __  Feb __  Mar

_ 01 ____ 1994 _____ 10.1 ____ 6.4 ___ 4.8 ___ 6.5 ___ 5.6

_ 02 ____ 2011 ______ 9.6 ____ 6.0 ___ 5.4 ___ 3.8 ___ 8.3

_ 03t____ 1818 ______ 9.5 ____ 3.6 ___ 4.4 ___ 4.3 ___ 6.8

_ 03t____ 2015 ______ 9.5 ____ 9.7 ___ 5.4 ___ 4.9 ___ 5.8

_ 05 ____ 1938 ______ 9.4 ____ 4.4 ___ 4.2 ___ 5.6 ___ 5.8

_ 06 ____ 1743 ______ 9.3 ____ 4.9 ___ 1.4 ___ 2.9 ___ 4.8

_ 07 ____ 1730 ______ 9.2 ____ 3.4 ___ 1.9 ___ 2.2 ___ 6.0

_ 08 ____ 1817 ______ 9.1 ____ 2.5 ___ 4.4 ___ 2.7 ___ 4.5

_ 09 ____ 1881 ______ 8.9 ____ 3.9 ___ 5.2 ___ 6.1 ___ 7.4

_ 10t____ 1939 ______ 8.7 ____ 3.2 ___-1.4 ___ 2.6 ___ 6.0

_ 10t____ 2009 ______ 8.7 ____ 3.1 ___ 1.4 ___ 2.8 ___ 6.1

_ 12t____ 1821 ______ 8.6 ____ 6.4 ___ 4.7 ___ 6.3 ___ 7.8

_ 12t____ 2014 ______ 8.6 ____ 5.2 ___ 4.4 ___ 4.0 ___ 6.4

_ 14t____ 1899 ______ 8.5 ____ 2.2 ___ 4.4 ___ 2.6 ___ 3.7

_ 14t____ 1951 ______ 8.5 ____ 5.5 ___ 2.7 ___ 3.4 ___ 6.6

_ 14t____ 1953 ______ 8.5 ____ 6.9 ___ 2.9 ___ 2.6 ___ 5.8

_ 14t____ 1978 ______ 8.5 ____ 3.9 ___-0.4 ___ 1.2 ___ 4.7

_ 14t____ 2002 ______ 8.5 ____ 5.7 ___ 4.5 ___ 3.9 ___ 7.5

_ 19t____ 1913 ______ 8.4 ____ 5.1 ___ 3.7 ___ 6.8 ___ 6.1

_ 19t____ 1997 ______ 8.4 ____ 5.8 ___ 5.2 ___ 7.3 ___ 7.9

_ 21 ____ 2018 ______ 8.3 ____ 6.9 ___ 4.0 ___ 6.7 ___ 7.8

_ 22t____ 1822 ______ 8.2 ____ 1.6 ___-0.1 ___ 3.1 ___ 5.0

_ 22t____ 1963 ______ 8.2 ____ 2.6 ___ 3.4 ___ 4.5 ___ 4.3

Average of 23 ______ 8.8 ____ 4.7 ___ 3.3 ___ 4.2 ___ 6.1

__________________________________________________________________

ANALYSIS __ 

The signal of a mild November is basically extinguished from the data within the first month, the averages are all quite close to long-term (all CET) means for each month, perhaps a bit of a mild signal for March overall. 

There are a few relatively cold winters in the set, indicating that a mild November will not prevent a colder turn with snow on the ground. Even Jan 2012 which shows up as a somewhat mild January had that colder signal by mid to late month. 

The chances for at least some colder synoptics after a very mild November are encouraging. Only a small number of the sample were above normal for every month of the four that followed the mild November. It has to be said though, the trend over time is for increasing temperatures in this data set, although as 2009-10 showed, not exclusively so, and then on the other hand as far back as 1881-82 they had a mild winter following a mild November.

 

[damianslaw]

5 minutes ago, Roger J Smith said:

There can never be a reliable "winter is over" signal in November. Pessimism to mid-season is perhaps valid in some cases but never past let's say mid-January as shown in 1946-47 (very mild start to Nov 1946 which at 8.1 was one of four tied 24th warmest). That said, top 23 November CET values have only seen the following results:

Rank ___ Year ___ CET Nov __ Dec __  Jan __  Feb __  Mar

_ 01 ____ 1994 _____ 10.1 ____ 6.4 ___ 4.8 ___ 6.5 ___ 5.6

_ 02 ____ 2011 ______ 9.6 ____ 6.0 ___ 5.4 ___ 3.8 ___ 8.3

_ 03t____ 1818 ______ 9.5 ____ 3.6 ___ 4.4 ___ 4.3 ___ 6.8

_ 03t____ 2015 ______ 9.5 ____ 9.7 ___ 5.4 ___ 4.9 ___ 5.8

_ 05 ____ 1938 ______ 9.4 ____ 4.4 ___ 4.2 ___ 5.6 ___ 5.8

_ 06 ____ 1743 ______ 9.3 ____ 4.9 ___ 1.4 ___ 2.9 ___ 4.8

_ 07 ____ 1730 ______ 9.2 ____ 3.4 ___ 1.9 ___ 2.2 ___ 6.0

_ 08 ____ 1817 ______ 9.1 ____ 2.5 ___ 4.4 ___ 2.7 ___ 4.5

_ 09 ____ 1881 ______ 8.9 ____ 3.9 ___ 5.2 ___ 6.1 ___ 7.4

_ 10t____ 1939 ______ 8.7 ____ 3.2 ___-1.4 ___ 2.6 ___ 6.0

_ 10t____ 2009 ______ 8.7 ____ 3.1 ___ 1.4 ___ 2.8 ___ 6.1

_ 12t____ 1821 ______ 8.6 ____ 6.4 ___ 4.7 ___ 6.3 ___ 7.8

_ 12t____ 2014 ______ 8.6 ____ 5.2 ___ 4.4 ___ 4.0 ___ 6.4

_ 14t____ 1899 ______ 8.5 ____ 2.2 ___ 4.4 ___ 2.6 ___ 3.7

_ 14t____ 1951 ______ 8.5 ____ 5.5 ___ 2.7 ___ 3.4 ___ 6.6

_ 14t____ 1953 ______ 8.5 ____ 6.9 ___ 2.9 ___ 2.6 ___ 5.8

_ 14t____ 1978 ______ 8.5 ____ 3.9 ___-0.4 ___ 1.2 ___ 4.7

_ 14t____ 2002 ______ 8.5 ____ 5.7 ___ 4.5 ___ 3.9 ___ 7.5

_ 19t____ 1913 ______ 8.4 ____ 5.1 ___ 3.7 ___ 6.8 ___ 6.1

_ 19t____ 1997 ______ 8.4 ____ 5.8 ___ 5.2 ___ 7.3 ___ 7.9

_ 21 ____ 2018 ______ 8.3 ____ 6.9 ___ 4.0 ___ 6.7 ___ 7.8

_ 22t____ 1822 ______ 8.2 ____ 1.6 ___-0.1 ___ 3.1 ___ 5.0

_ 22t____ 1963 ______ 8.2 ____ 2.6 ___ 3.4 ___ 4.5 ___ 4.3

Average of 23 ______ 8.8 ____ 4.7 ___ 3.3 ___ 4.2 ___ 6.1

__________________________________________________________________

ANALYSIS __ 

The signal of a mild November is basically extinguished from the data within the first month, the averages are all quite close to long-term (all CET) means for each month, perhaps a bit of a mild signal for March overall. 

There are a few relatively cold winters in the set, indicating that a mild November will not prevent a colder turn with snow on the ground. Even Jan 2012 which shows up as a somewhat mild January had that colder signal by mid to late month. 

The chances for at least some colder synoptics after a very mild November are encouraging. Only a small number of the sample were above normal for every month of the four that followed the mild November. It has to be said though, the trend over time is for increasing temperatures in this data set, although as 2009-10 showed, not exclusively so, and then on the other hand as far back as 1881-82 they had a mild winter following a mild November.

 

Interesting viewing, there are some notably not relatively cold winters in there, 1939-40, 1978-79 and 2009-10, three of the top coldest winters in the north at least in the last 100 years.

However, some notably very mild winters as well. 

Good to compare with say coldest Novembers and what happened. 

There have been a few colder than average Novembers in the last 30 years or so followed by very winters, 1988 and 2016, but doubt these rank as top coldest. The likes of 1985 were followed by at least one cold winter month. However, 1919 for example wasn't followed by a cold one.

 

 

[Catacol]

Scanning various feeds and sources the pattern of extremes globally continues. We know how extreme ice loss was this summer, and the open water on the siberian side was extraordinary. Still is to be honest. The antarctic polar vortex is extremely cold - off the bottom of the chart at 50hpa and quite a long way off the bottom..... the spike in GLAAM in October was the most aggressive of any La Nina since 1958.... and the PMM (Pacific Meridional Mode - I'm not familiar with this measurement but this article helps)

Your eight-minute speed date with the Pacific Meridional Mode | NOAA Climate.gov

WWW.CLIMATE.GOV

---

Are sea surface temperatures located north of the equator important for El Niño or La Niña development? Yes! Introducing the...

- is very positive and actually way out on its own for its positive strength in a Nina season. With regards to the ENSO/PMM relationship at present Eric Webb has written - "we're basically in uncharted territory..." And note Steve Murr's reference to 9 degrees at night in Svalbard yesterday evening. Good grief.

 

Conclusion? The climate doesn't do things by halves these days - not often anyway. Things seem to push the envelope. Glosea might be a poor run and it took the gloss of my day yesterday - but wrapped up in probability projections of above or below normal 500hpa patterns is a weather context that is constantly breaking the rules. I dont expect this to change. Standing by my general sense of chances early and late for cold and I think standing by a belief that if it goes mild it will go mild in a big way - and if it goes cold it might well go big too. Masiello notes that the AAM profile for the autumn so far is a closest match for.................2017. Hmmm. Anyone fancy a Beast rerun??

[Catacol]

If you haven't encountered Griteater before he is worth following. Combines a degree of pattern matching with logical thinking. To be honest - when reading his forecasts it puts me off ever doing one myself because he has such a high level of detail I couldn't hope to be as good. Anyway - anyone wanting to know about pattern forecasting with a strong ENSO element save this pdf. A big learning opportunity.

However - if you want snow this winter then perhaps don't read it all the way to the bottom. His top analog is terrible for us - and his second best analog is 1988/89.... nuff said. If he is correct we best prepare for a lot of water..........

http://m.uploadedit.com/busd/1605190618743.pdf

 

Edited November 12, 2020 by Catacol

[Chesil View]

9 hours ago, Catacol said:

Scanning various feeds and sources the pattern of extremes globally continues. We know how extreme ice loss was this summer, and the open water on the siberian side was extraordinary. Still is to be honest. The antarctic polar vortex is extremely cold - off the bottom of the chart at 50hpa and quite a long way off the bottom..... the spike in GLAAM in October was the most aggressive of any La Nina since 1958.... and the PMM (Pacific Meridional Mode - I'm not familiar with this measurement but this article helps)

Your eight-minute speed date with the Pacific Meridional Mode | NOAA Climate.gov

WWW.CLIMATE.GOV

---

Are sea surface temperatures located north of the equator important for El Niño or La Niña development? Yes! Introducing the...

- is very positive and actually way out on its own for its positive strength in a Nina season. With regards to the ENSO/PMM relationship at present Eric Webb has written - "we're basically in uncharted territory..." And note Steve Murr's reference to 9 degrees at night in Svalbard yesterday evening. Good grief.

 

Conclusion? The climate doesn't do things by halves these days - not often anyway. Things seem to push the envelope. Glosea might be a poor run and it took the gloss of my day yesterday - but wrapped up in probability projections of above or below normal 500hpa patterns is a weather context that is constantly breaking the rules. I dont expect this to change. Standing by my general sense of chances early and late for cold and I think standing by a belief that if it goes mild it will go mild in a big way - and if it goes cold it might well go big too. Masiello notes that the AAM profile for the autumn so far is a closest match for.................2017. Hmmm. Anyone fancy a Beast rerun??

Quite so Catacol. It has long been a contention of mine that the further we get into this new uncharted climate change territory that extremes will happen at both ends of the scale. Obviously there will be more at the warm end but it worth remembering that Beast was the coldest March spell CET wise since 1845 and in my nick of the woods Dec 2010 was colder then Dec 1890,so the coldest on record. In 28 years of recording weather locally my top 5 minima have all been recorded in the last 11 years.

[damianslaw]

2017-18 indeed was a sandwich winter, some modest cold early on in December, a mild middle in January but less so in the north, and a cold, notably very cold end. Our most varied winter since 12-13.

Increasingly it seems we are getting quite extreme results, when its mild it's super mild, so I buy into the logic we entering new depths so to speak. If we can get super mild we can get super cold, less likely but not out of possibility. A super cold northerly or easterly as well as super mild southerly. 

[SLEETY]

despite global warming etc,we still  seem to be able to get severe cold like Nov, dec 2010 and  march 2013 where even here on South coast had 3ft snow drifts mid month then severe cold spell end of feb  2018 into March 2018 with coldest ever march max temps,recorded.

 

So maybe more extreme both ends of the scale.

Glosea bust already?