moses
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Posts posted by moses
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People are banging on about the possible snow on Monday but thats still F.I yet.
Look a bit closer to now... Thursday evening...
Mmmm.......... What I find disconcerting is the models are showing one thing and people like The Met Office/ John Holmes on Net Weather video forecasting rain with a wintry mix. Surely not?
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ECM control run is even colder than the operational!
http://www.knmi.nl/exp/pluim/vijftiendaagse/Data/15DAAGSE_06260_NWT.png
Back to the GFS and if this is going to trend towards the UKMO/ECM don't expect this to happen in one run. I have found in the past that if the GFS does trend towards the Euros then its a slow backtrack with each consective run.
As the period in question is between +96/+120 I don't expect this to be resolved until tomorrows 12Zs. However lets hope the Euros remain with this trend because the longer they do the more likely the GFS will backtrack.
Re: Control Run Briefly, what is it and how does it differ from the operational.....
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This ECMWF surely, just surely cannot be correct - although I really do hope that it is!
It's exceptionally wintry from start to finish...
850's down to -4 to -6 by T+120... Even at T+72 - T+96 the pattern is set..
T+168 850's of -10 across Ireland, -12 across the UK...
Followed by a complete reload from the North.
The entire British Isles would be cut off by Day 10 if this run were to occur & with the agreement this evening on the ''upgrading'' of next weeks' easterly I'm sure that the pros at Exeter must be a bit concerned to say the least.
One word, from start to finish - STUNNING.
IF this run were to verify then we would be heading for a Feb 1991, or even better!
Something out of Dr Who, for sure. However, I can still imagine the Met Office update tomorrow: Cooler everywhere, some wintry showers creeping into the SE later in period.. Again , still FI .I'll believe that when I see it. However, the models are tending to upgrade ............ How then does this compare with 1947(Jan) Jan 63, surely a more severe spell than that???
Question: Has there EVER been a synoptic set up like this, either T+ 0, t+ 2500 or in the last 60 years? If so, when!
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Its not going to be the 18z that backs down, my real fear is waking up and seeing the downgrade. Till then just about anything could happen however.
HD, it is an outlier but the control run is using the same data as the op run but comes out with a different evolution. This is so key because it shows this could go either way still.
Stunning 18z GFS though it has to be said, probably would be some good snow at home.
Briefly, I'm following all this synoptically, but what IS a control run , compared to the operational? Why the difference and the importance?
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Some sensational snow events on the 06Z Parallel Run..
In fact, several feet of snow would fall widely across the country..
In the somewhat more reliable, it looks like rather heavy snow could be falling by late next Tuesday if GFS were correct..
Time for this forecast yet??
A STUNNING 06Z GFS PARALLEL RUN!!!!
For the third time, would someone kindly tell me what a parallel run is?
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Ok, I've heard all the wild excitement about these computer models and their prediction of an a potentially stunning synoptic set up
How then, do they compare with Jan '79 Dec 81 or Jan 63 in terms of cold and snow ( Obviously a question for experts) in terms of high pressure orientation/blocking, 850 temps, jet track and longevity??,
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For the likely evolution from the UKMO, check out the evolution for early December 1959:
http://www.wetterzentrale.de/archive/ra/1959/Rrea00119591207.gif
Exceptionally cold continental air around Moscow, but mild southerlies over Britain.
http://www.wetterzentrale.de/archive/ra/1959/Rrea00119591209.gif
The low hangs around W Britain, the cold easterly flow is shunted away to our north.
http://www.wetterzentrale.de/archive/ra/1959/Rrea00119591211.gif
Finally an easterly, but a watered-down, probably dry cloudy version.
http://www.wetterzentrale.de/archive/ra/1959/Rrea00119591213.gif
And in with the south-westerlies.
Unless it's a cold raw wet outlook with snowfalls restricted to high ground that you're after, I don't think this UKMO output is very favourable at all! However, the December 1959 analogy resulted from a Scandinavian High and not an omega block and this is partly why I, like Tamara, KW and others, think the UKMO may be being too progressive with its evolution.
Interesting comparison. Where is the link for historical charts like this?
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Would anyone care to eleaborate on these subtle differences? Thanks
Guy
PLEASE!
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Would anyone care to eleaborate on these subtle differences? Thanks
Guy
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Could someone please tell me the difference between 500 and 850 charts - sometimes the 500 charts have lots of blue - but there are mild temperatures over the same region
What 850 temps do we need for snow?
What about the figures 530 dam on the 500 charts - what use are they?
Also - the phrase "height rises over greenland" - what is this in relation to the charts?
thanks
Guy
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There's been a bit of this discussion in other threads, especially "Early Signs of Autumn".
It's too early for waxwings - their periodic eruptions into the UK (caused by failures of the rowan berry crop in their native range, or population explosions following a good previous berrying season) are generally in winter and never before October.
As to this year's heavy fruiting, it follows on ideal conditions rather than presaging anything. Lack of spring frosts allows more fruit to set, and ample water as it swells allows more to be retained - in dry weather trees and shrubs tend to automatically drop a proportion of their crop so that the remaining fruit/berries can form properly and ripen, given adequate warmth. Lack of warmth is seldom an issue in native (or climatically suitable) plants these days, though it may be a problem for grapes this year if things do not warm up: currently the vines are heavily laden - little thinning has been needed because of the high rainfall - but they badly need some heat now and into September to ripen properly.
Um, yes, sorry - we have gone off topic, haven't we?
There were three blackbirds on the lawn this morning, two males, one female - all moving in clockwise circular rotations of 1.04m radius, finishing in an easterly direction bearing 089 degrees. The last time this happened according to my records was ....... AUGUST 1978 , then August 1995.??
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For flips sake, it's the middle of July!
'They' haven't got a clue, we haven't got a clue.
I can't believe I am even bothering to waste 10 minutes of my time (I'm a slow typer) posting this. What differencve would it've made if they'd said it was going to be a cool winter, at this stage?? They've got the same data we have, it's a speculatative LRF not one for three days time.
Surely their response was obvious??? We know they take little note of SSTs and with a very strong possibility of La Nina cropping up, how on earth could they've gone for a blistering cold forecast??
Frankly then : a negative NAO of -0.34 will give what from December to Feb say?
A few more frosty days than last year , perhaps a few more snowy days/ foggy days - and that's it
Historically, this reading appears much better than many years over the last 20
Should we be reasonably pleased in terms of a reasonably good winter compared to recent years?
Guy
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That summary for the w/c 18th Dec is erm, quite surprising with the recent model output.
I'm afraid if the models showed -15 temps and arctic lows, the BBC mild rampers would suggests temps at or slightly below average- a hideous forecast that, I think will change, - - like last year's did if memory serves me correctly
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Which charts would be useful in detecting the jetstream
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Not sure what your getting at ... but looking at that chart it has an Easterly flow over the UK, though not a particuarly cold one, it would have brought cool sunny days with overnight frosts if it was from a dry source - or may have brought low cloud to the East if there was moisture caught in the flow. Can think of far more depressing charts than that.
Looks like it was the 500 instead of the 850
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This is very depressing for Nov 62
Any thoughts
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500hPa is mid level in the troposphere at about 18000 feet and the temperatures at this level give a fair view of the synoptic pattern. You should be able to get a rought idea of where the jet stream ought to be by looking at the steepest temperature gradients. You should be able to get a feel for how air is moving and from that the general synoptic pattern.
Heres a quick first look at a 500hPa chart.
Not too far out when looking at the more detailed charts at that level.
Note that where the 500hPa winds are strongest is where rain is likely to occur most.
850hPa is a lower level in the troposphere at about 4500 feet. This gives a reasonable indication of low level temperatures with -8C at this level equating to about 0C at ground level. It also is a good level to get of feel of where the frontal systems are. Warm air and strong temperature boundarys being likely places for fronts.
Here is another quick interpretation of a chart.
A little out but not too far off the detailed chart.
As easy quick glance charts these charts give a lot of information and really cannot be beaten ,however delving into some of the other charts will tell you a lot more if you are so inclined.
Cheers mate!!
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Could anyone please explain what these figures mean on the top of weather models eg GFS/ECM etc
and what thrie significance is - why two separate readings
Thanks Guy
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Thanks Steve. That was the most informative and lucidly argued post I've read on here for a while. I was going to write something about the El Nino/PDO/NAO predictions/effects myself, but it's just as well you did it for me, as you clearly have a far more comprehensive understanding of these matters than I do with my rather sketchy knowledge (though I feel slightly less sketchy now).
I find it interesting that the forecast for the NAO this winter has changed so quickly from predicting a slightly positive oscillation,
to predicting a negative one. Is this the sort of thing which can work as a trend, so that changing factors which have obviously led to modifications in NAO forecasts, keep changing in the same way, so that forecasts go even more negative?
Who has predicted a negative NAO?
Thank goodness for some decent argument away from the......"it was colder last winter, so we've got a really good chance of it being colder this winter", stuff. And no-one getting upset! Marvellous!Yes and if there is a real link between Arctic temperatures and UK temperatures (which, though the link sounds as if it should be an obvious one, the graph shows a clear link only in the present warming trend) just think how much warmer our latitudes are likely to be, when (much more likely than "if", in my opinion - trend-changing odds again), the Arctic warms further and we lose the present-day cooler-than-the-30's/40's influence? Only speculation, as I'm not sure we can link Arctic temps to warmer/colder BI conditions at all, but both the Arctic and the BI will be affected by GW, as it continues to progress.
Paul, in a very wet Dawlish, with a very depressed dog.
PS I hope the breakfast GW debate from a warmer point of view hasn't spoiled your cornflakes, folks.
I'm surprised no one has mentioned the north atlantic drift or whatever it's called - and the fact that it is slowing down would give us greater chances of bad winters - or is this just the daily express getting too excited???
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Very good news for most of us!
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Forecast for Winter 2006/7
N
Note that even an average winter is likely to include some notable cold snaps and snowfalls.
Precipitation
Is this on the basis that many of the recent winters have been well above average in terms of not snowing and warmth
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i can think of a few that come close ...
Yuk
Mucky,
Bleurgh,
it's definately a dreich day here!
What about mild ........above average!!
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Completely potty.
The chances of this winter being colder than average are about 20% The chances of it being warmer than average are about 70%.
Since 1990, this percentage of warm as opposed to cold has actually been exceeded. There is nothing, apart from some highly iffy LRFs, that indicate anything different, The Met office reckon it will be a milder than average winter, but, quite frankly, I don't actually believe them either. Long-range forecasting is not good enough to predict the coming winter.
I can't see why on earth people who are desperate for a cold winter get all stirred up about this when, actually........no one knows. You are hope-casting. No more.
Damien; you really must qualify these, quite ridiculous assertions that you make that there is actually evidence for people to believe a cold winter is in the offing. It may be; but the odds are well in favour of it not being colder than average. I'd trust them.
Paul
Interestingly, when did the met office forcast last winter as being colder than average etc. I remember end of october - but not September - what evidence do they have again?
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I think what might also be fun is to try and forecast the prevalent types of weather from the local lore that comes up. If we get a formal old wives forecast it can go in the mix with the others and we'll see where it ranks. If it wins then we can try again for Spring and Summer. Before long we'll have Everton Fox consulting his seaweed for the month ahead!
Well said....... Simple truth is that the most reliable method is the most useful .... I wonder if someone could put all the scientific methods and find out which is the most reliable - over last 20 say - cause and effect?
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I'd agree with all of this.
I think in terms of long range you can currently get some of the goodies you need but not all. For example, its possible to see what sort of cold pooling exists and what kind of pattern the various oscillations are on. From this you can tinker with probabilities. Lets say there is a huge amount of cold pooling around Greenland or Siberia in November. From that its no great shakes to conclude that the chances of a colder than average December/Jan etc are higher than were they not there, it falls from there to the right conditions/blocks etc to allow the cold air to advect to our shores. I remember Dawlish used to play the 70/20/10 card for predictions - ok, thats probably not a bad call on the past 20 years evidence but it needs tailoring to whats going on at point of guesstimate. Generalisations can be made with probabilities of them being correct increasing the nearer the mark you get. Further than that it really is pinning the block on the landmass.
Instincts are fair enough, if I see birds flying south in mild conditions earlier than they usually would I would still plump for colder conditions on their way despite LRFs to the contrary!
I saw 6 blackbirds on the lawn this morning -5 males 1 female
Records suggest this is a 1 in 5 chance of a colder than average winter................
How Much Snow Have You Got?
in Spring Weather Discussion
Posted
Yep, im from Chesterfield too. 48 cms in Whittington. Truly astounding. I think the 78/9 winter was the last time this happened. Then, everyone got together, shovels etc... and sept all driveways/access roads. Now its every man for himself. I was genuinely shocked at the amount. I do feel the Met O have grossly underestimated this one!!