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.

 

 

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.

 

 

 

 

 

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.

 

 

regards

steve

 

Afternoon All-

 

This is update / Comments number 1 on the Winter forecast as it stands.

 

we are now 1/6th of winter complete & the first half of December is out, -

Here is the first half monthly anomaly-

 

 

If we look at the forecast the clear picture depicted was one of an unsettled Westerly Picture with bouts of PM air- & that's exactly whats happened with the support of the slightly displaced Azores high.

The CET return to the 15th is 4.7 & -0.2 for the month - again within the range of temps given all be it at the top end.

 

In terms of H2 of December the forecast is / was for a considerable change to blocky conditions in week 3 ( so out to about the 22nd ) - The models are now firming up on the start of the change to a blocked flow on the 23rd as the Atlantic & - EPO high Start to develop

 

This was clearly defined in the 03/12/14 & should this happen will change the 500 anomaly chart for the whole of December towards one that was forecast for the overall month...

 

 

Steve Murr

Posted 03 December 2014 - 00:26

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,........

 

The Ensemble Data also now supporting the 'interest in Xmas day' & if your having a flurry on a white Xmas - get in quick for the North west before they slash the odds...

the forecast did indicate statistically it should be drier & colder- which at this stage looks pretty solid....

 

 

Also a key metric in the forecast was the AO indicator & the expectation that mid to late December would see at least 1 return of -2.5 with 2 more periods in jan.

Well here is the updates 17th Ensembles   ( updates around 2pm)

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.shtml

 

the expectation is the Period around the 26-30th of December may well see this negative value reached.

 

With Xmas day ushering in a pattern change I would stab for a landing zone of the CET around mid to low 4's currently with an outside chance into the 3's - which is well within the forecast zone...

 

 

 

So far so good....

 

regards

S

Edited December 17, 2014 by Steve Murr

[SMU]

Afternoon All-

 

Well, not the greatest of forecasts in terms of accuracy. I will give it 4/10.

the OPI & all cold forecasts were a bust.

 

Overall for the north ( mainly the NW) its been a better Winter than last, & by default of the fact that there's been some snow falling in the south its been better here to. However on the whole a below par winter for the UK driven by the AO being persistently in AO figures.

 

There's been much analysis of the MJO, + Stratosphere / Troposphere this winter, however I think to be honest I haven't seen any 'continued' signals that things were going to move to a blocked pattern despite some other posters posting week in week out that things were on the turn.

 

The last embers of winter are flickering out- nowt much in the suites for 10 days- which gives us just 10 days left.

Obviously availability for snow in March, however past weeks 1+ 2 it doesn't reduce off pretty fast.

 

 

This is me signing off for winter. Ive had enough- another winter going down as a crap one.-

 

S

[Polar Maritime]

Its been a very average British Winter so far here.

[snowrye]

fair play mate for making a forecast,i think we were all hopefull of something decent after the opi etc.i ,along with many others enjoy reading your posts,and as someone who loves weather,but only has a limited understanding,its fantastic to have people with knowledge to learn from,keep up the good work

[4wd]

A cold and raw one at times here - so far.
Near average snow falling/lying days I suspect. 
February has clocked up 25mm - almost all fell as snow.

Edited February 7, 2015 by 4wd

[Bristawl Si]

Hats off to Steve for being downright honest about his forecast and not trying to claim much success.

It's been a v ordinary winter here, no snow, but the one blessing has been the lack of storms.

An early warm Spring can't come quick enough; hopefully it delivers.

[Gael_Force]

Elsewhere I called it the 'nearly' winter but in reality it will sit as pretty average in the climatology of the British Isles. We are now starting to compare winters to the few extreme events in recent years but these were way off base in regard to normal -  IMO, can possibly be attributed to the lowest solar cycle for more than a hundred years.

 

We'll not have long to wait to see if they can be replicated in coming winters, when current cycle winds down - if not, some other quirk of chance/permutation of drivers was at work and who knows when the like will be seen again.

[TEITS]

Despite the winter I am still very grateful to Steve M for attempting a LRF. I have always been of the opinion that providing an accurate LRF for the UK is incredibly difficult. You will find it is difficult to be accurate for a large land mass like the USA let alone a tiny island like the UK.

 

Here in Peterborough the winter has been poor. Only 1 day of lying snow with the greatest depth being 7cm, 3 days of snow falling and my lowest min has been -4C. Compared to last winter an improvement but disappointing overall.

 

What has stood out for me this winter is the sheer lack of eye candy from the models even into F.I. Like Steve says the AO has been positive and whilst at times the PV has split, the split vortices have never been in the right position for the UK.

 

Finally as already mentioned I believe 2009, 2010 winter's we're linked to the sunspot cycle but I also believe the series of volcanic eruptions were another factor. Although a long way away im looking forward to the winters between 2018-2020!

[Snowyowl9]

Its been a very average British Winter so far here.

For you I would`ve its thought its been much higher than average for snowfall as TM has done well too.

Here 4/10 as theres been no easterlies.

The atlantic was the main driver but it did deliver 3inches December 4inches January and 3inches followed by another inch.

Edited February 7, 2015 by Snowyowl9

[feno13]

Despite the winter I am still very grateful to Steve M for attempting a LRF. I have always been of the opinion that providing an accurate LRF for the UK is incredibly difficult. You will find it is difficult to be accurate for a large land mass like the USA let alone a tiny island like the UK.

 

Here in Peterborough the winter has been poor. Only 1 day of lying snow with the greatest depth being 7cm, 3 days of snow falling and my lowest min has been -4C. Compared to last winter an improvement but disappointing overall.

 

What has stood out for me this winter is the sheer lack of eye candy from the models even into F.I. Like Steve says the AO has been positive and whilst at times the PV has split, the split vortices have never been in the right position for the UK.

 

Finally as already mentioned I believe 2009, 2010 winter's we're linked to the sunspot cycle but I also believe the series of volcanic eruptions were another factor. Although a long way away im looking forward to the winters between 2018-2020!

Hmmm 7 cm of snow , not in the Peterborough I live at I am afraid  

[TEITS]

Hmmm 7 cm of snow , not in the Peterborough I live at I am afraid  

Yes around 7cm here. The accumulation is clear to see on the roof.

 

[Polar Maritime]

For you I would`ve its thought its been much higher than average for snowfall as TM has done well too.

Here 4/10 as theres been no easterlies.

The atlantic was the main driver but it did deliver 3inches December 4inches January and 3inches followed by another inch.

Yes very good for lying snow round here, Rated around 8th in 50 yrs or so. Still have around 3cm of compacted snow covering 60%.

[Bobd29]

A lot of credit to Steve, the final result may have been Mother Nature 1 Steve Murr 0, but I can't wait for the repeat fixture next winter, cheers Steve