Is there only me not getting excited about this colder spell being forecast?

Originally Posted by: Saint Snow 

https://www.aer.com/science-research/climate-weather/arctic-oscillation/

Very interesting 😾 + 🐦

Originally Posted by: Jeff 

Alex Deakon gas just said over at metoffices Instagram page that snow next week is very unlikely away from high ground, and that indications for the coming winter suggest more likely then not it will be a mild one!!

Originally Posted by: picturesareme 

I seem to recall that the MetO made comments along those lines before the start of the 2009/10, or at least that it would be milder and wetter than the 2008/09 winter was.

In the end, it turned out to be the coldest one overall for just over 30 years if I'm not mistaken.

Originally Posted by: David M Porter 

I seem to recall that the MetO made comments along those lines before the start of the 2009/10, or at least that it would be milder and wetter than the 2008/09 winter was.

In the end, it turned out to be the coldest one overall for just over 30 years if I'm not mistaken.

Originally Posted by: David M Porter 

Not a great deal worth getting excited about though... is there?

6-10C with cold E/NE winds and plenty of cloud for most. Maybe some overnight frosts where clouds clear and winds fall light.

Drizzle and light showers near windward coast at times, and maybe some winteryness to higher grounds in the north. 

Originally Posted by: picturesareme 

From the article:

"...

While Scandinavian blocking is often the precursor of a significant stratospheric PV disruption, Greenland blocking is the symptom or the tropospheric response to the PV disruption.  The GFS is now suggesting that the blocking over Scandinavia will slide west towards Greenland, shifting the monthly means from Scandinavia towards Greenland (Figure ii).  In that scenario presumably the threat of a PV disruption and the longer term risk of severe winter weather across the NH but especially northern Eurasia would subside while the risk of short term risk of severe winter weather across Northern Europe and the Eastern US would increase with the longer term prospects more in doubt. 

..."

To me that suggests a front loaded winter.

Originally Posted by: Maunder Minimum 

Yesterday the NAO and AO were both coming up in negative territory, i am keen to know why they both flipped to quite positive territory over night? 

Originally Posted by: tallyho_83 

Updated JAMSTEC keeps the UK, Ireland and a bit of Scandinavia below average through winter the rest of Europe is a bit above average

Originally Posted by: Gavin D 

Ireland and the northern half of England look most favoured, which would suggest northern blocking.

Good stuff.

Originally Posted by: Saint Snow 

John Hammond expecting big changes with Winter on the way 

Originally Posted by: Gooner 

And he's sticking to that vehemently, dismissing the model output too.  I can't decide if thats admirable or arrogant, but either way its interesting...

Originally Posted by: beanoir 

I know cold spells develop in a variety of ways, but I can see nothing in the MO like the build-up to the brilliant Decembers of 2009 or 2010.

Originally Posted by: Saint Snow 

He's not suggesting it will be like those winters specifically, but he does expect a change to colder winter conditions in early December

Originally Posted by: beanoir 

I think it's time now for me to give my final prognosis on the coming Winter.   Picking up where I left off a couple of weeks ago, I determined that the years 1976, 1977, 1986 and 2009 were the best overall analogues to the current season.

So, the latest trends then...

ENSO - As far as I can see, no unexpected changes to the El Nino development have occurred.

QBO - Still shows a very disorganised transition to the wQBO.  I mentioned previously that a new chunk of eQBO was appearing in the top of the strat.  That is still showing, and even is being shown to develop and intensify over the next week or so, spreading down to 5hpa.  And the existing eQBO is still evident below 40hpa.  It almost looks as if we're seeing a new eQBO region spreading down before the wQBO has even got going!   So for me, it still looks like a weak wQBO through the Winter.

Atlantic SST profile - The cold zone is still there south of Greenland, although some warmer patches are appearing.  It doesn't seem to  have sparked off a raging jet so far, so maybe this season it will only have a muted effect at best.

Solar activity - remains very low.

And finally on to the synoptic matches for November 2018.  Checking the current ENSO/QBO/Solar analogues, I find that the Novembers of 1976, 1986 and 2009 are pretty decent matches to November 2018.  Furthermore, the mean 500mb heights anomaly forecast for the remainder of November 2018 match quite well with 1986 and 2009, strengthening those two analogue years.

So, that results in the following final analogues for Winter 2018-19, in order of best match:

2009 (ENSO, Solar Cycle, October and November synoptic matches)

1986 (ENSO, Solar Cycle, October and November synoptics)

1976 (ENSO, Solar Cycle and November synoptics (up to current time)

1977 (ENSO, QBO, PDO,)

1985 and 1995 were weaker matches (Solar cycle and October synoptics)

I have to say- I've been making Winter forecasts now for around 15 years or so, and these have to be the coldest/wintriest set of analogues I've seen in that time.  All the six top analogues led to cold Winters, some significantly so.

So my final prognosis is for a "Cold Winter" for 2018-19.   In particular, the top 3 matches contained a particularly significant wintry period in the second week of January...

Jan 2010- second week had widespread significant snowfall

Jan 1987- second week saw severe snow & cold in the E & SE.

Jan 1977- second week saw major snowfalls across many areas.

So summing up...

Coldest/snowiest period of Winter 2018-19 likely to be focused in, or close to the second week of January, with brief cold snaps before and after this. Most of the analogue years saw further cold/snowy spells into February, apart from 1977, so I think there's potential for rinse/repeat cold snaps carrying on right through February.

Rainfall amounts hard to determine, but probably not far from average this Winter, perhaps favouring the driest weather in northern areas.

Finally, with such a cold set of analogues, I think there is a reasonable chance of a "very cold" Winter similar to 2009-10 !

Originally Posted by: Andy J 

I think it's time now for me to give my final prognosis on the coming Winter.   Picking up where I left off a couple of weeks ago, I determined that the years 1976, 1977, 1986 and 2009 were the best overall analogues to the current season.

So, the latest trends then...

ENSO - As far as I can see, no unexpected changes to the El Nino development have occurred.

QBO - Still shows a very disorganised transition to the wQBO.  I mentioned previously that a new chunk of eQBO was appearing in the top of the strat.  That is still showing, and even is being shown to develop and intensify over the next week or so, spreading down to 5hpa.  And the existing eQBO is still evident below 40hpa.  It almost looks as if we're seeing a new eQBO region spreading down before the wQBO has even got going!   So for me, it still looks like a weak wQBO through the Winter.

Atlantic SST profile - The cold zone is still there south of Greenland, although some warmer patches are appearing.  It doesn't seem to  have sparked off a raging jet so far, so maybe this season it will only have a muted effect at best.

Solar activity - remains very low.

And finally on to the synoptic matches for November 2018.  Checking the current ENSO/QBO/Solar analogues, I find that the Novembers of 1976, 1986 and 2009 are pretty decent matches to November 2018.  Furthermore, the mean 500mb heights anomaly forecast for the remainder of November 2018 match quite well with 1986 and 2009, strengthening those two analogue years.

So, that results in the following final analogues for Winter 2018-19, in order of best match:

2009 (ENSO, Solar Cycle, October and November synoptic matches)

1986 (ENSO, Solar Cycle, October and November synoptics)

1976 (ENSO, Solar Cycle and November synoptics (up to current time)

1977 (ENSO, QBO, PDO,)

1985 and 1995 were weaker matches (Solar cycle and October synoptics)

I have to say- I've been making Winter forecasts now for around 15 years or so, and these have to be the coldest/wintriest set of analogues I've seen in that time.  All the six top analogues led to cold Winters, some significantly so.

So my final prognosis is for a "Cold Winter" for 2018-19.   In particular, the top 3 matches contained a particularly significant wintry period in the second week of January...

Jan 2010- second week had widespread significant snowfall

Jan 1987- second week saw severe snow & cold in the E & SE.

Jan 1977- second week saw major snowfalls across many areas.

So summing up...

Coldest/snowiest period of Winter 2018-19 likely to be focused in, or close to the second week of January, with brief cold snaps before and after this. Most of the analogue years saw further cold/snowy spells into February, apart from 1977, so I think there's potential for rinse/repeat cold snaps carrying on right through February.

Rainfall amounts hard to determine, but probably not far from average this Winter, perhaps favouring the driest weather in northern areas.

Finally, with such a cold set of analogues, I think there is a reasonable chance of a "very cold" Winter similar to 2009-10 !

Originally Posted by: Andy J