Winter Model Discussion Thread 12Z onwards 5/1/13

[tinybill]

http://www.meteociel...hp?mode=2&ech=6

http://www.meteociel...?mode=2&ech=204

good afternoon all could it be things are going to get a bit colder after about Jan 12 just going by what the BBC weatherman said make the most of the mild weather this weekend!!

Edited January 5, 2013 by tinybill

[weather eater]

Yes, I think that is the crux of it. We are seeing solid agreement on the end of zonality, but the tendency for the NWP at the moment is to build HP over or very close to the UK just beyond the reliable timeframes, we want to see subsequent runs start developing higher latitude blocking.

That’s true Ian but if we have a long cold spell then that may just be a precursor to a better pattern later, helped along by cold air over the British Isles and very cold air close to it. Personally I very much doubt if the models truly have a clear picture at the moment and although what you describe is a trend at this point of time, I wouldn’t be surprised to see that change substantially over the next few days. Frankly at this point of time, as long as the wretched rain stops I don’t care, cold and snowy, cold and dry or very cold and snowy, all will do.

Edited January 5, 2013 by weather eater

[BLAST FROM THE PAST]

chionmanic just a quick question not sure what thread to stick it in ,we currently now have a m- class solar flare being forecast , do youthink this may have an impact if any on the current warming ? just there are some thoughts on how solar activity impacts HLB

When is this flare forecast for? That could be interesting.

Going off line for a couple of hours to go home from work so will look forward to the 12z. Indeed I always look forward to model watching BUT now its really interesting.

06z t384 is my chart of the week so far

BFTP

Edited January 5, 2013 by BLAST FROM THE PAST

[pyrotech]

chionmanic just a quick question not sure what thread to stick it in ,we currently now have a m- class solar flare being forecast , do youthink this may have an impact if any on the current warming ? just there are some thoughts on how solar activity impacts HLB

The only impact this will have is possible Aurora, nothing short term with weather are proved or noticed. Statistics have been colated and nothing signifigant found in short term.

The biggest impact is the very low minimum we went through and now the low maximum, we are either at maximum or are forecast to be in 2013. During the last week the sunspot number has increased signifigantly increasing the possabilities of flares, depending on the extent of this sudden increase we could still see a small count when smoothed count is done. The low maximum up to now and very minimum could have effect, with a time lag, just like our shortest day and coldest part of winter have a cumalative time lag.

The ens are looking positive with both the 2m and 850mb temps (mean) showing lower temps, i would suggest that the models can only run forwards from the current situation and normal variations for the different runs. The effects on the troposphere from the SSW will still play the models up. Its a guarantee that many in Northern hemisphere will see very cold conditions in next few weeks, but where exactly ( compared to our little island) is still to be finalised. We will see the models change rather suddenly as the effects happen and we could possibly see some very interesting charts if blocking falls right for us.

I would expect GFS to show interesting charts in fi early next week, but caution will be required, as it either starts pushing it back in time or brings it forwards. Expect a model rollercoaster - and the express news paper to make its armegeddon winter headlines.......again

[Frosty.]

The 2009/2010 winter and Nov-December 2010 big freeze had no SSW before them at all though. So a cold stratosphere doesn't prevent a big freeze / severely cold winter and I guess we'll see over the next few days and weeks what warm stratosphere may produce. Is interesting watching how the models react to it.

It would be nice to get some kind of ensemble agreement at something solid at a somewhat realistic timeframe, say +144 or so, are a while a way from that ATM though.

You won't have long to wait for ensemble agreement in the T+144 hour range, a cold spell is coming but not a sudden change to cold, more subtle with temps returning to average first which will increase the risk of frost but for the north and west it will take a bit longer with unsettled, windier and milder weather early in the period but there is growing confidence for our first decent cold spell soon after mid month, or possibly before.

[Jaffusmaximus]

The only impact this will have is possible Aurora, nothing short term with weather are proved or noticed. Statistics have been colated and nothing signifigant found in short term.

The biggest impact is the very low minimum we went through and now the low maximum, we are either at maximum or are forecast to be in 2013. During the last week the sunspot number has increased signifigantly increasing the possabilities of flares, depending on the extent of this sudden increase we could still see a small count when smoothed count is done. The low maximum up to now and very minimum could have effect, with a time lag, just like our shortest day and coldest part of winter have a cumalative time lag.

The ens are looking positive with both the 2m and 850mb temps (mean) showing lower temps, i would suggest that the models can only run forwards from the current situation and normal variations for the different runs. The effects on the troposphere from the SSW will still play the models up. Its a guarantee that many in Northern hemisphere will see very cold conditions in next few weeks, but where exactly ( compared to our little island) is still to be finalised. We will see the models change rather suddenly as the effects happen and we could possibly see some very interesting charts if blocking falls right for us.

I would expect GFS to show interesting charts in fi early next week, but caution will be required, as it either starts pushing it back in time or brings it forwards. Expect a model rollercoaster - and the express news paper to make its armegeddon winter headlines.......again

1947 was slap bang in the middle of a Solar Max year.

http://www.google.ie/imgres?um=1&hl=en&safe=off&tbo=d&biw=1517&bih=741&tbm=isch&tbnid=NQYbcobVThTntM:&imgrefurl=http://www.climate4you.com/Sun.htm&docid=8AACqO_b9RPpYM&imgurl=http://www.climate4you.com/images/SIDC%252520DailySunspotNumberSince1900.gif&w=880&h=434&ei=KzroUM6KGsewhAeAs4DoBQ&zoom=1&iact=hc&vpx=392&vpy=143&dur=1214&hovh=157&hovw=320&tx=131&ty=78&sig=112560139402265891678&page=1&tbnh=133&tbnw=272&start=0&ndsp=30&ved=1t:429,r:2,s:0,i:88

[nick sussex]

Interesting to see the MJO moving more quickly into those more favourable phases which begs the question is it the chicken or the egg.

Does the SSW exhibit forcing on the MJO to get its skates on to move into those phases, or were they going to move anyway.

Or are we looking at a feedback feeding itself, ie the strat warms, the major warming occurs, this forces the MJO to move into phase 7/8 which then feeds back into helping propogation.

I've read some research suggesting the MJO is more important but I really don't buy into this, IMO the greater change in the NH pattern is exhibited by a major SSW.

We've seen many favourable MJO phases which are mediated out by other factors, the mediating factor on propogation seems to be the initial base state of the NAM or AO, the link being that a neutral/positive AO at the initial warming leads to statistically significant propogation effect.

Which if you think about it makes sense, the shock to the PV is greater when its bloated and thinks its going to haunt us for the whole winter. An already weak PV may not explode with quite the same ferocity, therefore the shockwave on the NH pattern is lessened.

This also brings into question the research post SSW effect on CET how many of these were in relation to neutral/positive NAM base state at initial warming and how many with an already negative AO.

Anyway I'm probably boring everyone now! So I think we still have alot to learn regarding SSW's.

[pyrotech]

http://www.meteociel...hp?mode=2&ech=6

http://www.meteociel...?mode=2&ech=204

good afternoon all could it be things are going to get a bit colder after about Jan 12 just going by what the BBC weatherman said make the most of the mild weather this weekend!!

Yes, but remember this is for next week, with high pressure ridging in over the UK, slack winds and less cloud we will lose radiated heat at night. I don't believe this is a forecast for very cold conditions and snow. Its a normal cooling from exceptional mild towards the normal with what would be expected with this orientation of high pressure. They would not be able to talk about cold conditions two weeks away as the senior forecaster dictates the line.

Its still a positive, as getting colder temperatures on the ground does help, especially over Europe as it minimises the modification when any cold floods from the North. But for now we are looking at from mild to normal winter temperatures scenario.

[snowking]

The only impact this will have is possible Aurora, nothing short term with weather are proved or noticed. Statistics have been colated and nothing signifigant found in short term.

The biggest impact is the very low minimum we went through and now the low maximum, we are either at maximum or are forecast to be in 2013. During the last week the sunspot number has increased signifigantly increasing the possabilities of flares, depending on the extent of this sudden increase we could still see a small count when smoothed count is done. The low maximum up to now and very minimum could have effect, with a time lag, just like our shortest day and coldest part of winter have a cumalative time lag.

I've been reading up on solar effects (more especially over a longer period with the 11 year cycles) much more recently as its one of the areas of meteorology (or, perhaps more accurately, climatology) which I don't have much knowledge of. It seems to me that cycle 24 is likely to be a fair bit longer than currently projected, and it wouldn't surprise me if we didn't see the end of the (albeit very low) max until around late 2013/early 2014, particularly given the longer than expected closing minimum from cycle 23, and its very much a sign (along with the current very low maximum) that we could be headed towards something akin to the Dalton/Maunder minimums - the next sign of that, incidentally, would be cycle 24 being longer than expected - for cycle 25.

Undoubtedly something has changed in our winters in the past few years on a hemispheric scale at the very least, and looking around there are few signs that point to the cause being anything other than solar.

Anyway, better leave it there before I get in trouble. Nothing to see here folks....

SK

[Stu_London]

There is a fair bit of getting carried away with the emotion within these threads at the moment. To me, the form horse at the moment seems to be mild high over us for a few days followed by a less mild high over us for a while later.

As was predicted by myself and others, the ensembles (in FI) have gone haywire and are chucking out a wide variety of solutions - this will continue for the next few days until the next pattern change is nailed down and by this time FI might be as near as +60 or +72.

I like Ian's idea of mapping any cold spell collapse in the models (I nearly started a new thread myself in the General Discussion Area, after THAT Ecm run in December, to map and record for posterity a cold spell collapse and I wish I had now), however I feel this should maybe have it's own thread and is still a little premature on the current output.

[blizzard81]

chionmanic just a quick question not sure what thread to stick it in ,we currently now have a m- class solar flare being forecast , do youthink this may have an impact if any on the current warming ? just there are some thoughts on how solar activity impacts HLB

I must admit, this worries me a great deal with regards to scuppering the possible upcoming cold spell.

If I remember correctly, Glacier Point suggested that increased solar activity could have been one of the main

factors which contributed to the failed cold spell back in December. It would be great to hear what GP thinks of this

latest increase in solar flares and what impact (if any) it will have on the weather.

[pyrotech]

1947 was slap bang in the middle of a Solar Max year.

http://www.google.ie...29,r:2,s:0,i:88

I do not understand?

Perhaps these posts should be in the solar thread, but anyway

What has 1947 being in solar max have to do with anything?

Firstly for any signifigant climate changes you need cumalative years of low solar max and solar min. Then you get a lag of several years. So our lowest for many years minimum would take several years with the lag to have an effect. Like around now not during the actual minimum. I think we would need a end to max now, and another low minimum to see any recordable climatic changes. To see lag and effects see Dalton and Maunder minimum.

[southbank]

BFTP .... The NOAA space weather prediction centre are forecasting a m-class flare over next 3 days , now I stress there may be no correlation to how this all pan out but sure will be interesting to see if there are any interaction at all with solar flares , SSW , other teleco connections and indeed HLB , just preferred there wasn't a flare at this stage !!!

[Jaffusmaximus]

I do not understand?

Perhaps these posts should be in the solar thread, but anyway

What has 1947 being in solar max have to do with anything?

Firstly for any signifigant climate changes you need cumalative years of low solar max and solar min. Then you get a lag of several years. So our lowest for many years minimum would take several years with the lag to have an effect. Like around now not during the actual minimum. I think we would need a end to max now, and another low minimum to see any recordable climatic changes. To see lag and effects see Dalton and Maunder minimum.

Same as was mentioned above, GP suggested that solar output may have had a negative effect on the outcome of the last Dec possible cold spell. So what I am highlighting is that the winter 1947 took place during a year of increased solar activity but as they say the rest is history.

[Methuselah]

1947 was slap bang in the middle of a Solar Max year.

http://www.google.ie...29,r:2,s:0,i:88

Precisely Jaffus! If modern-day scientific equipment/analysis are incapable of detecting any correlation - let alone any causal link - between one-off solar flares and any lack of cold weather, I guess the most prosaic explanation would be that: there is no correlation - let alone a causal link...

But, we digress!

But I do see a link to the models: solar flares, like 'shortwaves' can come in very handy a 'get out of gaol free' cards...

Edited January 5, 2013 by Rybris Ponce

[snowking]

BFTP .... The NOAA space weather prediction centre are forecasting a m-class flare over next 3 days , now I stress there may be no correlation to how this all pan out but sure will be interesting to see if there are any interaction at all with solar flares , SSW , other teleco connections and indeed HLB , just preferred there wasn't a flare at this stage !!!

I certainly couldn't comment on any links with our weather, but from my reading, we get something like 75 solar flares a year. That means that we average more than 1 a week. I realise an M class flare is a little stronger than many of them, but I am yet to find research which suggests much of an influence of these.

Heres a quote from the Australian BOM website:

Much research has been conducted now over many decades in an attempt to link sunspots or other forms of solar activity to the weather. The subject is often extremely popular with the media. Countless hours have been spent in trying to convince the world that droughts or floods are the consequence of an unprecedented outburst of solar fury. Unfortunately, for each paper published showing a relationship between the floods of some year and sunspots, there can usually be found a contradictory paper showing either no relationship of perhaps a relationship between sunspots and a drought of the same year. Some scientists believe there may be a small connection between weather disturbances and solar activity. Still others believe there is very little connection. The reason why many scientists have difficulty accepting that solar activity has a major affect on our weather is very simple. Even a large solar eruption (either a coronal mass ejection or a flare) - although a gigantic explosion by Earth standards - only releases an amount of energy comparable to what the whole sun emits in a few seconds. In other words, solar activity is only a very small variation of the total solar output. Much larger variations in the received sunlight at the Earth's surface are due to the Earth's tilt and its elliptical orbit.

Im sure either GP or Roger will be the man to ask, but I cant find much to link the two myself

Kind Regards

SK

[TAFKAP]

BFTP .... The NOAA space weather prediction centre are forecasting a m-class flare over next 3 days , now I stress there may be no correlation to how this all pan out but sure will be interesting to see if there are any interaction at all with solar flares , SSW , other teleco connections and indeed HLB , just preferred there wasn't a flare at this stage !!!

That solar flare has about as much chance of scuppering this cold spell as Westham do of winning the champions league. Why go out of our way to look for obscure and implausible reasons as to why a cold spell which hasn't even arrived could be a no go.

Edited January 5, 2013 by TAFKAP

[Frosty.]

I'm enjoying the charts that are appearing here regularly and you can almost taste the expectation too, but what I'd like to know is......what could happen weatherwise to prevent the cold and snow arriving? I'm deliberately not getting my hopes up as they were dashed in December, but I'd just like to know if there's a chance of that happening again in view of the fact that the various forecasts for once all appear to be singing from the same hymn sheet.

I share your concerns mistyqueen but there is now a great deal of hope in the strat warming which the meto are using as the basis of their more wintry 16-30 day update, the models are now showing a colder trend within the next 7-10 days which is really good news.

[J10]

Latest Ski Blog out now.

http://forum.netweat...h-january-2013/

Synoptic Extract here

Synoptic Charts

The weather pattern starts with low Pressure over Greenland and the Western Atlantic, High Pressure ridging from Iberia through the UK to Western Scandinavia and much of Western mainland Europe, with a mild South Westerly flow here. Low Pressure over Eastern Europe with Northerly winds keeping it cold here.

Little change over the weekend, but the pattern moving slightly further east, putting more of Europe into the mild air, with the cold in Eastern Europe pushing away further east.

By Tuesday and Wednesday, the High Pressure covering most of mainland Europe, so the cold restricted to Far East and into Greece. Largely mild over the UK and the Alps during this time, however always colder to the East, with cold air fringing eastern parts of Austria and very cold for Bulgaria further East.

Towards the end of the week a change in the pattern with Low Pressure over Scandinavia introducing a cold NE flow over Scandinavia and into the UK, and over Northern parts of mainland Europe Possibly turning very cold over NE mainland Europe, and generally turning cooler over the Alps and the UK

Edited January 5, 2013 by Jackone

[Ian Brown]

That solar flare has about as much chance of scuppering this cold spell as Westham do of winning the champions league. Why go out of our way to look for obscure and implausible reasons as to why a cold spell which hasn't even arrived could be a no go.

Well you can say that but many times one was able to look at the models at ranges between T120 and T192 and think 'how can this go wrong ?' And it very often did.

[TAFKAP]

Well you can say that but many times one was able to look at the models at ranges between T120 and T192 and think 'how can this go wrong ?' And it very often did.

Provide some proof solar flares were to blame for those times.

[Met4Cast]

I think too much emphasis is being placed on solar flares. It's my understanding that prolonged activity is what effects our weather, rather than short term bursts.

- Prolonged high solar activity = Wetter, milder European winters

- Prolonged quiet solar activity = More blocked, colder European winters

I'm not sure ANY link has been made between single solar flares and short term weather effects.

[Ian Brown]

Provide some proof solar flares were to blame for those times.

I can't and I don't know that was the reason for any or all of the failures - what was true that for many years we were unable to achieve stable high latitude blocking, this may have been down to latent energy from the warm Summers/Autumns, strong solar phases, SSTs or a combination of all three.

[Kentish Snowman in Yorks]

We may not get the deep cold and copious amounts of snow that most on here want but the increasingly implausible suggestions as to why such cold may not arrive is becoming laughable!

Given that the Northern Hemisphere is currently in winter and bearing in mind the size of the landmass of the UK, I would imagine that the chances of a forecast solar flare causing our tiny island to become / remain mild are miniscule, and that is being generous!

Why would this flare pick on the UK and not the rest of the Northern Hemisphere? Or is it being suggested that this flare will cause the early onset of spring across the entire hemisphere?!

It's all a conspiracy I tell ya...

Eyes down for the 12z...

Edited January 5, 2013 by Kentish Snowman

[Zenarcher]

Giving models time to catch up has been said and it is happening,

GFS a few days ago for the 9th,

And now today for the 9th less energy going over our North and better heights showing,

ECM has ended up doing the same thing,

Few days ago for the 9th,

Today for the 9th,

UKMO for the 7th a few days ago,

And what it shows today,

Much less PV and things further West,