Catacol

He put out a dramatic tweet a few days ago warning us Brits to beware because a bitter winter was on its way. Said the temp profile of the N Atlantic was similar to that around Alaska which has caused recent recurring cold over there.

My met office site is broken and has been for 24 hours - says it cant display any severe weather warnings. Where are you getting these from? The link on your post just takes me to the broken page...

Not sure that is true. Lots depends on the severity of Nina or Nino - it is not a one size fits all weather driver. My understanding is that a weak Nino to neutral ENSO is statistically very good for cold weather over here. Strong La Nina conditions tend to favour a more active vortex in the early part of winter...

Well - I'll say this. You have gone for a very early prediction of the general pattern and I have said before that I think your success rate is astonishingly high. People would do well to take note of this "trendcast" (if I can call it that rather than a forecast) and remember that you released it a full 3 months before Xmas. Success at that range would be very impressive, and I would love to know as to your methods - as I quietly remarked last year...

Thank you - this post helps me a lot in growing my thinking.

Sorry Chio - hadnt meant to sound tetchy. The graph you post there does show a remarkably narrow and predictable temp range and drop from July through until Oct/Nov. I presume this is the case back through the record. I had managed somehow to miss any comments on QBO (though I knew it was currently easterly and likely to remain so at the bottom of the atmosphere throughout winter) but had not picked up on any posts recently about Brewer-Dobson. That is a factor I am still getting to grips with. Are these the only factors? What I was meaning to try and express was the sense that throughout autumn the SSW "specialists" seem to be shrugging shoulders a bit and saying - "wait for November and then we will open the shop", but taking a hypothetical scenario for a minute: let's imagine that the strat has a major warming at the end of November, a sign of a disrupted vortex 3 - 4 weeks later. Is there no mechanism still for predicting a likely stratospheric temperature rise at this time until we are very close to it? GP talks about mountain torque events impacting on temps; I have read you refer to wave breaking from higher up. Neither I fully understand yet. But these are comments that seem to pop up from Nov to March... and then we dont hear much of it at all. Do torque / wave breaking events not happen in early autumn, or do they happen but have no effect?

Roger - your Jan and Feb forecast looks like an almost carbon copy of the forecast (from memory) you came up with last year. Is there any particular recurring reason for this, or just chance? Last year the Siberian High got close - ever so close - but was constantly blocked and bent the wrong way by the ridging Azores High. Do you see the Azores High playing such a large role this Jan/Feb?

I suggested the same thing on the first winter thread, but it got ignored. Seems to me that the forecasting tool which is the stratosphere is still in its infancy, because it surely cannot be that nothing matters until we get to November, at least if we are talking long term trends. Accepted that we cannot possibly get highly detailed information this far out - but as trendcasts go it doesnt seem to be a tool that is used in autumn.

Yes - agreed - but are there no signals in the Strat itself that are worth looking at yet? Come winter GP will use his amazing crystal ball to look up to a month or more ahead with possible strat changes. Last year he hinted relentlessly at a warming start in the latter half of January, and from memory he came up with this in late November. (maybe a little later??) So are there no strat signals now that might point to conditions in November for example? Just wondering...

Yep - certainly impatient... but also a little uncomfortable with the concept that we cant possibly begin to look at forecasts for anotehr 4 - 6 weeks. I am no expert for sure, but to my simple mind it strikes me as odd that long term forecasts try to make sense of sequential processes and indicators, but when it comes to winter nobody seems to bother looking until late October. Why is that? Is there some aspect of global climate or weather patterns that makes the months of September and/or October redundant as tools of forecasting?

Wow - here near Taunton we have had 53.8mm of rain already this month. Anything but dry I can tell you.

You should have been in the SW last night. Heavy thunderstorms for hours... kept me up until after 2am watching relentless lightning and torrential rain...

Well - this shows that even basic meteorology confuses me. The warm waters around Greenland I took to mean lower than average pressure as I thought that warm water and low pressure go hand in hand. Conversely I took the cold water belt further south to indicate the suppressed Azores High sitting in place, with cold water encouraging the maintenance of strong high pressure. The NAO is a pressure gradient and not a temperature gradient - as I understood it - and therefore it looked like an enhanced pressure gradient and therefore a +NAO. So can someone help me here - the warmer than average temps off Greenland therefore indicate a HIGHER than average pressure to the semi permanent Icelandic Low, and the cold water to the south suggests a LOWER than average pressure to the semi permanent Azores High. Is this correct now?? What puzzles me there is that I would have thought that if warmer water does indeed promote cyclogenesis then it would automatically follow that low pressure systems born around Iceland would be deeper... and therefore of lower pressure not higher? Or is the NAO about temperature and not pressure after all? I can clearly see that the temperature gradient is less steep... so -NAO based just on that? Rather confused I am now... Sorry to ask such a basic question. I thought I understood this already!!

Fred - the finer details of this weather hobby are still things I am absorbing... but is that current temp profile in the atlantic not indicative of a positive NAO? If so then is the current setup not an example of a deeply negative PDO actually linking up with a +NAO? An exception to your rule therefore?

For the first time since reading your forecasts this one is way out, and at quite short range too. Does this mean that the rest of the forecast needs adjusting according to new data, or do the July and August predictions stand strong no matter what might be going astray in June?

Good read RJS - I always enjoy reading your forecasts and admire your methods (thought I dont understand them...) You have a high hit rate - in my opinion. However I think you have been out of the country a bit long!! Sometimes you rather overcook your winter estimated minimums and likewise your summer maximums. If anywhere in the UK hits 39 degrees I'll eat more than just my hat... and I dont think 37 is anywhere near a reality either. That sort of extreme just doesnt happen here - the ocean has too great an effect. I'm sure someone somewhere will pull out figures to prove that such extremes have happened once in a blue moon... but there is no way we will have temperatures like that widespread across the country. It is very unusual indeed for temperatures to break 30: instead anything in the 26 - 29 bracket here would be considered hot and 30 degrees rare.

Good grief - why couldnt the current synoptics have hit us in winter. :-( Someone upstairs is laughing.

Looks like Roger has got April bang on from 2 months away. Amazing. I'm hoping for once he is wrong - with regards to May anyway. As a cricket coach I can do without a wet month following such a wet end to April!

Forgive my very long term inspired question, but if I understand GP correctly he felt as far back as October that he had a sense of the winter to come. Has anyone ever taken a domino approach to this? In other words if the Oct wave and following winter gives rise to the probability (if GP is proven correct [again] ) of a major strat warming in March on the back of another wave then how far down the line can we go? What does this suggest in terms of pattern for the summer, and is it possible even then to give a call on the following autumn and winter? A daft question I expect... but there must be grogs out there with more time and expertise than I have got who have looked at this. How close are experts to being able to give a 12 month approximate forecast, or do the variables just get too complex to deal with?

Then you have been very lucky. The SW has not seen a flake all winter unless you are on Exmoor or Dartmoor, and a handful of windscreen scraping frosts hardly constitutes a winter to me. It has been the worst in a number of years down here for cold... so far.

Cold miserable rain in Wellington. Air temp 2 degrees; no snow coming here. Missed it by 50 miles last week; missed it by about 30 miles this week. Winter so far, despite some days of cold, has been very disappointing and current suggestions are that the northerly next week will be an east of the UK only event. Not impressed. :-( NAE got my hopes up earlier today too : that'll teach me to bother to check charts again!

NAE is rolling out now... Not good for the SW - ie Somerset and SW of there. The precipitation has dived south earlier than predicted, and it will not turn to snow much further west than Yeovil from the looks of it. Very annoying to have a last minute downgrade - the 06z run was really good. :-(

Yes - a key tool. From memory some time in the next 30 mins...

The postcode thing on the Met site is tosh. Dont bother using it - I dont know why they keep it on there. Read the weather warnings instead, and use the High Res NAE model to get the most up to date prediction of what will happen. Even then it is apt to get thngs off target, but it is nevertheless the best tool we have. Borderline event whatever the Met warning says. We need the front to slow down for sure - if it fires through at speed then little will stick even if it falls as snow. My gut feeling is that the precipiation has arrived rather on the early side and that this is not good news for snow lovers. We will see.

Wrong. Go check the NAE High Res over at Weatheronline. The link you want is http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=nae&MODELLTYP=1&BASE=201202091200&VAR=prty&HH=18&ZOOM=0&ARCHIV=0&WMO=&PERIOD= That will give you the best idea of what is going to happen.