S.Murr Winter Forecast 2014/15

[SMU]

1/12/14.- S.Murr

 

Please find below a rather compressed version of my notes for this forthcoming Winter, the thread below took around 20-30 hours are work so the actual forecast wasn't actually meant to take that long

The # posts are where the time went initially relating to the OPI however post that following up on the article around the ice loss & developing that theory - then the AO wasn't just a continuation.

 

https://forum.netweather.tv/topic/81676-winter-2014-15-preliminary-view-cold-possibly-very-cold-drier-than-ave/page-1

 

In terms of the preliminary thoughts please visit posts

#1  - Preliminary thoughts

#42- Ice Feedback - Taymyr Region

#46- The changing Faces of the AO.

 

My Composite years Are:

58/59

62/63

65/66

68/69

76/77

84/85

09/10

 

Now though with the ENSO forecast for neutral to shallow positive the ones highlighted in bold seem to be the closest-
 

 

Also preliminary CET forecast was

DJF  3.8. 1.5  2.9

 

 

With every Winter here we have advancements in the science that leads us into some thought processes that the following winter can be forecast in the latter stages of October & early part of November.

I firmly believe this is not the case, & with things like the OPI we need to see a continuation of the proposed pattern & composites throughout all of November to feel confident that the winter is taking shape how we expect.

 

The OPI this Winter being sub -2 has indicated that are set well....

 

OPI loading pattern-                                                       October 2014

 

                    

 

As was discussed in the prelim thread we managed good composite mapping from the negative phase, which was a negative AO & low height anomalies around Eastern Atlantic & Eastern Russia, Also a strong positive EPO pattern.

 

 

So have we traversed November in the same mapped fashion-

 

Well here is the November loading pattern for Negative OPI years-  & Nov 14

 

                             

 

The eastern atlantic low is still prominent, the height anomalies are more pronounced along 60n & whilst its not a BEST fit - its certainly more of a fit than the long term mean.

The other variable that I was waiting to see was the November Stratosphere anomalies, with the key focus over Western Russia for positive anomalies.

Again if we look at the 5 composite years for this winter then we would expect duplication this November.-

 

Composite years November Anomaly                                   Nov 2014

 

                        

 

There is a VERY good match for the composite years.( which to summarise are)

 

* Deep Negative OPI

* Positive ENSO

* Easterly QBO

* Key positive Strat indicator in Nov

 

Building the pattern then the predicted DJF anomaly charts are:

 

December -                                                            January                                                                  Feb

 

                         
 

 

These represent the general predicted pattern across the month, however December has the low height further North indicating that this is likely to be the mildest month.

This does make sense as the jet isn't fully as south as it should be. There is a slight offset to this in as much as its the only month that shows a mildly displaced azores high.

 

Also whats worth noting is the start of Winter for each of the composite years to see when we should expect a change to this 'blocky pattern'

 

The benchmark is the first -2.5 AO reading.

1958 =  Dec 15th

1965 =  Dec NA

1968 =  Dec 25th

1976 =  Dec 18th

2009 =  Dec 10th

 

so removing the outlier 1965 then MEAN average is 17th - so for those expecting deep cold before the first half of the month is finished is statistically only 20%.

 

indeed when we look at the anomalies for Dec split into 2 then we get the following-

 

All months reanalysed to 1-15.

 

1958                                                        1965                                                       1968

 

      

 

 

1976                                                        2009

 

 

 

Generally unsettled with low heights close by or just to the west of the UK.

 

 

refining my Composites to the top 3 now based on QBO & ENSO I would go with -

 

19 58/59

19 68/69

20 09/10

 

 

 

Summary using 3 composites.

 

Dec 2014

 

 

 

Monthly Summary -

 

Expect a very unsettled first half of the month with temps close to average with the suggestion of a higher frequency of polar incursions then maybe slightly below,

high rainfall especially in the NW,

Snow more focussed on the NW of Scotland & the hills doing very well, also NI may fair well in the colder incursions.

The CHANGE to more blocked conditions is favourable in week 3 but could manifest in week 2 - the CET for the month will be heavily related to how quick the pattern changes.

Christmas statistically would fit into a drier & colder category with a higher chance of a white Xmas for the North & North east.

 

Final CET estimate - range 3.7 to 4.7 so slightly below the 71-2000 average.

 

 

Jan 2015

 

 

Monthly Summary -

 

With the composites I have the suggested pattern is a very high frequency of continental flows effecting not just the UK but the heart of Europe, the MEAN average of the composites is 2.8 so certainly the expectation is a below average month.

I am expecting more of a NH 2 or 3 wave pattern which is the -EPO high, the Siberian/ Scandi high & of course High Greenland pressure.

The core of the cold should influence the East & the South, with Scotland & Ireland on the furthest edge- maybe even above average.

Jet stream wise a split flow around Greenland & south of the UK

 

Final CET estimate - Range 2.0 to 3.0 so again, below the 71-2000 average.

 

Feb 2015

 

 

Monthly summary   -

 

I am expecting a similar pattern to jan, although the pattern could begin to fade away with less of a continental Easterly & a warmer SE / southerly flow.

I would like to review this mid jan.

 

Final CET estimate - Range 2.5 to 4.0 - again at the lower end of the scale.

 

 

 

Stratosphere & waves / AO

 

 

Expect a much increased temperature within the stratosphere this year the composites are geared up around warmings in December ( Canadian ) however this often means feb is slightly colder in the strat- a Jan warming may well deliver sustained cold in Jan & feb.

 

The AO is expected to dip away to below the magical -2.5 level on 2 - 4 periods this winter. - The first is expected mid to late December , 2 more populating January & 1 more possibly in early feb.

Obviously these coinciding with the cold periods for the UK.

 

 

 

Hope you find the info useful, in my mind the first critical period to this forecasts success is the NH 500 MB anomaly charts for between the 15th & 25th of dec as we should see a considerable change to blocked conditions possibly aided & abetted by a Canadian warming although this doesn't have to be a feature......

 

regards

steve

Edited December 3, 2014 by Steve Murr

[A.J]

Steve, just wondering if you want to keep this as a stand alone thread or incorporate it into your earlier winter forecast thread?

[BLAST FROM THE PAST]

the CHANGE to more blocked conditions is favourable in week 3 but could manifest in week 2 - the CET for the month will be heavily related to how quick the pattern changes.

 

 

Excellent Steve....interested in the above sentence, what are you looking at for that to occur

 

BFTP

[SMU]

AJpool please lock the other thread even though I asked Lorenzo to open it.

 

Blast- tropospheric wave breaking-  3 wave

 

* -EPO ( or possibly + PNA)

* Scandi block

* atlantic ridge  into Greenland with some sort of retrograde.

 

Xmas 'COULD' be interesting.--- depends on timing of course,........

[A.J]

no worries, will do 

[Bobd29]

Fantastic amount of work, well reasoned and explained so that novices such as I can understand...many thanks Steve, May you be very close to the mark

[BLAST FROM THE PAST]

thanks for reply....glad you posted LRF mate

 

BFTP

[Mark Neal.]

Really pleased you posted your forecast Steve! You put a lot of work into it and very well thought out.. Good luck with it!

[DOdo]

Good Luck with it Steve

[Timmytour]

Great stuff Steve..... to some degree, whether it verifies or not is irrelevant,. There's a reasoned methodology and analysis there that can be refined in the future with the benefit that hindsight will bring and perhaps take us closer to the day when such forecasts are more consistently near the mark

But I happen to think that the efforts you've already put in, not just this year, but in all the previous years as well, are getting you nearer to this point then perhaps many others are.

For your sake, as a reward for your efforts, and for my sake from a purely selfish aspect as being a lot more representative of the kind of winter I want to see, I sincerely hope you are recognised in hindsight as having been very close to the mark

[starstream]

Really pleased you have posted your forecast Steve.

Here's hoping for a memorable winter 14/15.

[marksp]

echoing others on here and posts to come, thanks for the hard work, looks like your forecast as well as old man met posts suggest plenty of cold

action to come, again many thanks.

[V for Very Cold]

thank you for all your hard work and generosity in sharing with us - even I could understand (most) of it lol

[chionomaniac]

You have chosen a few different years in your originals to us Steve, but a few the same too!

 

Good Luck.

[johnholmes]

thanks for all the hard work Steve, well reasoned; 1 March and we will know how accurate it is.

[lorenzo]

Good luck with forecast Steve, lets hope we get the blocking coming through and a good shot at winter proper.

[MR EXTREMES]

well done steve good to see reasoning in your post and i got my fingers crossed for you.

[feb1991blizzard]

Good luck, we will need to see the strat getting a shift on with it to see the change in week 3.

[Man With Beard]

Thanks Steve, not massively different to a lot of other long-range forecasts on here, the 15th-25th of December seems key for something to give.

[joggs]

Good luck Steve,hope your on the money.My sort of winter that lol.

[Daniel*]

I respect you Steve that you chose to release your winter forecast following what has been said. that is the past now we must look to the future...January has always looked good, we will see. (Fixed typo)

Edited December 3, 2014 by Daniel*

[Steve C]

Thanks for posting your thoughts.

[Methuselah]

Let's just hope you are right, Steve...  

[Dorsetbred]

Steve, thanks for the time and effort that you have taken for this series of posts, and I was glad to see the present mail. Clearly you put a lot of work into producing these, and they are good reference for the future, like other well detailed winter outlooks (NW included).

Keep it up, and if a review is forthcoming midway then let's see that too, the weather does what the weather does, we mortals can but try and predicted her moves..

[Staffordshire]

Clearly a lot of hard work put in there, and for that I credit you!

A seemingly logical and objective methodology behind your forecast as well as a clearly laid out presentation made for a very good read!

Hopefully this is an accurate forecast!

Would love a white Christmas!