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A Winter's Tale

The Seasonal Forecast Thread

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46 minutes ago, mpkio2 said:

To be honest, I'm not too worried about what GLOSEA5 is predicting because (And correct me if I'm wrong!), but for Winter period last year, wasn't it  (And EC Seasonal Model) predicting a winter of HLB and cold for the UK?

Look how that winter panned out! :whistling:

If you look at the November 2016 prediction for temperature it showed above average for the winter months?

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1 hour ago, johnholmes said:

QWell best look away if you do not want warm water being pured on your cold hopes>

UK Met latest model output carries on with the same version over the last few months, see below for link

https://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

Of course it may be wrong but it is usually, not always of course, recent seasons not been totally out.

Oh dear, where’s the sick bag?!  There is no denying the GLOSEA 5 has been consistent for several months now.  My fears of a 1988/89 type winter could be well founded!

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Oh come on, when i checked before for nov/dec/jan they also went for way warmer than normal, and it looks like november will turn out to be colder, so dec and jan will have some cathing up work to do. It's just bullsuper duper, all those models. There is almost no place on the entire plant where there is a decent chance of cold winter. That's just not true.

I'm checking those models for years, and CFS never went for a cold winter in almost ten years, and in warmer years they turn out to be right, and in colder years they turn out to be horribly wrong.

Edited by Lakigigar

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Is the Netweather winter forecast going to be released this evening?  I thought it was supposed to be released today?

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I see that Accuweather are forecasting rain and snow for Watford, Herts on 25/26 December 1917, giving a max of +5 during the day on 25th with some rain and snow showers, 71% probability of precipitation with a wind SSE 15 kp/h gusting to 48 kp/h, followed by continuous moderate snow for 12 hours amounting to 18.8 cm during the night with a min of -2C, wind ESE 24 kp/h gusting to 46 kp/h.

However 26th shows the wind turning round to N with max rising to +5C, so we will have to be quick to catch it. 

Perhaps it's their Christmas present from them to us!  :) 

25.12.2017.docx

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2 hours ago, mike Meehan said:

I see that Accuweather are forecasting rain and snow for Watford, Herts on 25/26 December 1917, giving a max of +5 during the day on 25th with some rain and snow showers, 71% probability of precipitation with a wind SSE 15 kp/h gusting to 48 kp/h, followed by continuous moderate snow for 12 hours amounting to 18.8 cm during the night with a min of -2C, wind ESE 24 kp/h gusting to 46 kp/h.

However 26th shows the wind turning round to N with max rising to +5C, so we will have to be quick to catch it. 

Perhaps it's their Christmas present from them to us!  :) 

25.12.2017.docx

I didn't know Accuweather have been going for 100 years!! :rofl:

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1 hour ago, Don said:

I didn't know Accuweather have been going for 100 years!! :rofl:

A typo Don - put it down to my advancing age,   :oops:

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Might be getting somewhere but just need to change the position of the high centred just north of Olso, flatten it out and elongate it to east into Russia  to bring us more into a direct easterly flow.  :)

There's a fair bit of time yet for the situation to change. 

24.12.2017.png

Edited by mike Meehan

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Looking forward to the up and coming PM set up. Some are calling it 'cold zonal' , which is fairly accurate . The thing is IMO the PM set up can very easily switch round to a Artic or nne set up. where as a full blown zonal set up is hard to budge.

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Met office maps have updated for Jan the next 3 monthly period of Feb to April looks mild and unsettled

2cat_20180101_mslp_months24_global_deter_public.thumb.png.a5a62c287196e8cd340a7e23334ada67.png2cat_20180101_prec_months24_global_deter_public.thumb.png.cc9f7535ceeb5be493892774b7aacae6.png

2cat_20180101_temp2m_months24_global_deter_public.thumb.png.c5c7f5a0f341b32d566d545cc8388ce7.png2cat_20180101_t850_months24_global_deter_public.thumb.png.ace5cb1d3ff4fa2ae07462a42b4408fd.png

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Latest 3 monthly outlook from the weather company

Quote

 

European Seasonal Outlook: The Weather Company Expects Warmer-than-Normal Pattern to Continue in Europe into Spring

Jan 23, 2018

Wet and Windy Conditions Expected Across Northern Europe, Drier Southern Europe

Andover, MA, 23 January 2018 – For the aggregate February-April period, The Weather Company, an IBM Business, is forecasting above-normal temperatures for most of Europe, with slightly below-normal temperatures confined to parts of southwest Europe, including Iberia. Precipitation is expected to be above normal across the north and below normal across the south.

“While the major energy-demand centers of the eastern U.S. and east Asia have experienced a cold winter so far, the atmospheric pattern has not favored persistent cold in Europe,” said Dr. Todd Crawford, chief meteorologist with The Weather Company. “And most of the meteorological evidence suggests that this dearth of cold will continue through the remainder of winter into early spring, as the type of ‘blocking’ needed to get cold in Europe will likely not materialize.”

For the February-April 2018 period, The Weather Company is forecasting the following temperatures:

February

  • Nordic region – Warmer than normal
  • U.K. – Warmer than normal
  • Northern Mainland – Warmer than normal
  • Southern Mainland – Warmer than normal, except Iberia

March

  • Nordic region – Warmer than normal
  • U.K. – Warmer than normal
  • Northern Mainland – Warmer than normal
  • Southern Mainland – Warmer than normal, except southwest

April

  • Nordic region – Warmer than normal
  • U.K. – Warmer than normal
  • Northern Mainland – Warmer than normal, except southern Denmark/France
  • Southern Mainland – Warmer than normal, except central

 

 

4

https://business.weather.com/news/european-seasonal-outlook-the-weather-company-expects-warmer-than-normal-pattern-to-continue-in-europe-into-spring?utm_campaign=&utm_medium=social&utm_source=twitter

TRADER_T2M_DFN30_WSI_DAY3090_EUROP400_180124_091818.jpg

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Okay, so how did that long-range winter forecast actually turn out? 

I have copied it and pasted below, but in paragraphs with comments in green. These comments come after the paragraphs to which they refer.

(Roger Smith LRF for winter 2017-18 posted on 3rd of November 2017)

=================================================================

In general, I would look for a fairly cold winter to develop, almost all global drivers seem to be at least 50-50 in suggesting a mixture of rather cold zonal patterns and at least weak blocking episodes over the North Atlantic and European sectors.

^^ A bit too vague to be verifiable, I suppose. ^^

While I'm not optimistic about this being an exceptional winter, it could produce one spell of severe winter weather conditions, so I'm expecting it to finish perhaps colder than 3/4 of the past fifty winters or near the average of the past 360 as provided by the CET record. Perhaps the best way to describe the expected outcome is a typical 18th or 19th century winter, with at least one month well below normal in temperature.

^^ This was fairly accurate but a little cold-biased. The winter averaged 4.33 C (4.8, 5.3, 2.9 monthlies), had one cold month (Feb), and was colder than 30 of the past fifty (which would begin with 1967-68); these 20 winters were colder (in increasing degrees of cold) 1982-83, 1983-84, 2005-06, 1977-78, 1996-97, 2012-13, 2008-09, 1986-87, 1967-68, 1976-77, 1969-70, 1968-69, 2010-11, 1995-96, 1990-91, 1985-86, 1984-85, 1981-82, 2009-10, 1978-79. ... To be near the average of the whole CET period the winter would have had to finish 0.5 deg colder than it did, it ranked 129th (but tied with 130th to 134th) warmest overall. As to being a "typical" 18th or 19th century winter, that seems to fit better than it might many recent winters. There was no outrageously mild month, and one fairly cold one. But as a rough measure, I counted how many winters out of 200 (1701 to 1900) were milder than this past one, and found 59 out of 200 were milder. In fact about ten from the Maunder half-century were milder also. So this winter would not have been that unusual, whether "typical" is the right word or not. ^^

There are more signs of this being January than either December or February but the most severe portion of the winter could come fairly late into January and edge into early February. 

^^ No doubt those signs were the widely rumoured stratospheric warming which was delayed into mid-February. So the most severe portion of the winter almost missed winter (D-J-F) entirely. ^^

At the same time I think the set-up will produce some stormy episodes and not overly mild storms either, coming at the UK from a westerly or slightly northwesterly direction in some cases. The period from about mid-December to mid-January is favoured for this stormier period. 

^^ I think this was generally accurate. The stormy period of the winter was probably more like the first three weeks of January than the above, and many did come from a westerly direction more than south-westerly. Of course the end of February was stormy also, from a northeasterly direction. ^^

I could go into detail about why I think this may happen but I think it has been fairly widely discussed already that solar and PDO factors are generally in favour of colder outcomes downstream from both large oceans. The pattern expected in North America is for very cold weather to set up over western regions with oscillating extensions of this cold towards the northeast U.S., in other words, an up and down temperature trend for the western Atlantic. There are signs of at least mild blocking over Greenland and a trend to lower if not below normal heights over western Europe. 

^^ There certainly was a cold source in western Canada that sent periodic cold waves southeast, anomalies for the eastern states were bouncing up and down with more than the usual vigour all winter, although the trend was probably more mild than cold in that region. The other comments seem generally true. ^^

So I think the signs are more favourable than in many recent winters (other than 2009-10 or 2010-11) and finally the research model that I use (independent of most of the above reasoning) also shows a tendency to a colder turn in January in analogue years. 

^^ January had some cold days around 19th-20th but the most significant cold arrived before mid February, backed off for a while and returned with a sting in late February. ^^

Since the period after southern declination maximum and leading towards northern maximum is favoured for blocking and cold this further implicates late January with the northern max timing for the month around 2nd and 29th. The period of 2-4 January would be my best bet for stormy conditions and 18-20 December as well as 16-18 January secondary peaks. When you consider the overall trends then the best bet for a snowy interval would be during or after that mid-January peak of storminess. Given the high energy peaks available this winter, I will not be at all surprised if one of these winter storms is in the exceptionally severe category (either for wind or snow).

^^ These peaks of storminess verified well. The strongest winds in Ireland for example occurred on January 2nd, and there was a very severe storm across the North Sea (Frederike or some such spelling) that intensified over the eastern part of England and walloped the Netherlands quite hard (think that was 17th-18th Jan). As to whether these were exceptionally severe, probably not in the UK, locally yes in Ireland's case and certainly for the Netherlands a memorable storm. The end of February into first two days of March brought an exceptionally severe snowstorm to southeast Ireland and fairly severe in parts of England and Wales, but this wasn't a time period mentioned in the forecast. ^^

There are bound to be one or two very mild days in the mix given the high frequency of record or near-record highs in this climate phase, and the most likely times for those would be before the mid-December storminess peak, and possibly in late February when blocking may convert to a southerly flow. 

^^ The mildest days of the winter from CET stats (7.5 and above) were these .. 9.2 and 9.0 on 6th-7th of Dec, and 9.2, 9.0, 8.4, 8.7, 9.7 from 21 to 25 Dec, followed by 7.7 and 8.5 on 30-31 Dec 2017, then  7.9 on 4th Jan, 9.1 and 9.8 on 23rd-24th Jan, 8.9 and 9.3 on 29th-30th Jan; 7.9 and 7.5 on 19th and 20th of February. So in general this was incomplete at best, the warmth expected before the mid-December storminess was delayed like the storminess itself, and a cold spell around 9th to 14th December was not anticipated in the forecast. The January warmth came about when it would have been expected (mostly before northern max dates) but this was not discussed in the forecast because January was expected to see the colder trend setting in. The late February blocking occurred with some southerly flow ahead of it but this was blown away by stronger easterly flow after about the 24th. ^^

Overall, this forecast did better in its broad general assumptions than in the specific timing of events. I would give it a B for the overall assessment (it was a bit milder in general than expected but did fall fairly close to where it was placed in the long-term context), B for storminess commentary (some good hits there) and C for month to month variability (the only good feature was that there was one cold month, the timing was generally not good).

The exceptional cold and snow at the end of February and first two days of March was not really anticipated then, perhaps more about a month earlier from the wording of the forecast. Had there been some better guidance available about the timing of the stratospheric warming event that might have influenced the wording. This is not a part of my research that has received enough attention from me, as I have no working theory of cause and effect within the research paradigm (in other words, I am looking for a cause for these episodes that I can time out successfully, and so far this has eluded detection). 

The cold spell in December also fell through the cracks of the research index values, so I'm looking at that for clues for improvements. 

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Absolutely fascinating read @Roger J Smith , hopefully other members get to have a read as it was thread I didn’t know existed and only became aware of through twitter ! Full marks for putting an ‘against the usual grain’ forecast out there 

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Thanks for the forecast.  As a coldie, fingers crossed!

Edited by Don

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Very interesting read thanks Roger, I always look forward to your forecasts. Hope this one is on the money :snowman-emoji::reindeer-emoji:

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Brave, reasoned and fairly specific....well done Roger and thanks, April review will be interesting.

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 A very well thought out forecast let’s hope it very five looking forward to it all ready excellent read thank you roger.s

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A very interesting forecast Roger which if it came off would probably produce something not unlike 1978/79 here in the south. Where the cold and snow was broken by stormier milder spells at times.

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Interesting read Roger...my feeling is  the stormy spells may stem from the Northwest.... keeping it colder than average through these spells particularly for Northern Britain.

Or do you envisage them coming from a milder direction?

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On 24/01/2018 at 22:55, Summer Sun said:

Btw, that forecast went well for wsi  .......

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1 hour ago, bluearmy said:

Btw, that forecast went well for wsi  .......

Indeed, and the thing is that the Feb stratospheric warming event was well within the range of the models at the point at which they made that forecast. 

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