Winter 2012 / 2013 Part 3

[Formula_1_Fan]

Thanks Jethro, I'll have a good read of that tomorrow!

[Chris D]

All this ramping on here about a cold winter, anyway don't look at the GFS 18z , unless your like Gavin, Aka summer sun

Ah well as the Netweather saying goes, "it's only one run"

hahaha

[Snowy Easterlies]

true, it was the 18z, however lets hope some sort of Euro high don't set up shop over us now, like it did last autumn, all this optimism from people, about there being "good signals" for late autumn and winter and imagine the opposite happened, eg Bartlett high, southerlies, raging PV over greenland bringing dry settled rubbish,

surely it can't happen two years in a row can it, i remember people last year saying "its only october" then look what happened, no decent blocking came til February, anyway im not saying this is gonna happen, but we can't always put our faith into these good signals for northern blocking as sadly the weather is not that straight forward

Edited October 7, 2012 by Snowy Easterlies

[bluearmy]

Current modelling and output over thhe past few weeks certainly shows that there is an issue lowering heights to our north for any sustained period, allowing the jet to get a footholdin this area. That bodes well going forward and I suspect it must have something to do with SST's as we haven't seen any proper blocking set up in the area.

[BLAST FROM THE PAST]

Perhaps new areas of ice. What if those cold waters head down around the UK? i think something interesting is going to happen that we have not seen before, for that reason we do not know what the effects will be. I see all pointers towards less activity from the Atlantic as we get into Dec, could be earlier, more blocking cold blocks that will not shift as easily as would be expected.

I didn't want to say this now but i am actually seeing indicators that make me confident of what could be a colder then average late autumn progressing to a very cold blocked winter, as i see a higher risk of low pressure during November but cold, then we would most likely have snow.

Why should it be any different to 07/08? Let's not get away from ourselves here......BFTP

[Methuselah]

Why should it be any different to 07/08? Let's not get away from ourselves here......BFTP

As none of us knows what the winter holds, Fred, that's not a bad suggestion...

[shedhead]

As none of us knows what the winter holds, Fred, that's not a bad suggestion...

Agreed Peter... nothing wrong with speculation, but speculation is all it can be at this range, albeit (in some cases at least) educated speculation. If we're looking for facts, nights will be longer than days seems a safe enough call, even at this stage...

[Gavin Hannah]

Saw on twitter last night that laminate floori posted a tweet linking to http://www.iceagenow.info .............. Oh dear.

Joe laminate floori â€@BigJoelaminate floori

http://iceagenow.info/2012/09/arctic-blast-hammer-britain/ … Gonna be a long, cold winter for nw Europe

Edited October 7, 2012 by IBringTheHammer

[Gavin P]

Hi all,

Snow is one of the most difficult, if not the most difficult element to forecast in the UK, so I've done a guide/tutorial just explaining some of the most important things to look out for if you want to know whether its going to snow or rain;

http://www.gavsweath.../snowwatch.html

Hope your enoy it and I hope I've explained everything OK.

Many thanks.

Edited October 7, 2012 by Gavin P

[Summer Sun]

All this ramping on here about a cold winter, anyway don't look at the GFS 18z , unless your like Gavin, Aka summer sun

I didn't see the 18z (I never do) but the 00z has high pressure returning once more

So if the 18z seems similar to the 00z I guess

Edited October 7, 2012 by Summer Sun

[AWD]

I thought October was Autumn?

Does winter not start until December?

Edited October 7, 2012 by AWD

[EML Network]

Why, Ohh Why Ohh WHY are people looking for snow in the charts in October ??

Do me one favour ..if you DO see snowfall in a chart deep into FI ,(In October) then try also to look at the dew points for that same day , basic rule of thumb is thus...if you see snowfall being predicted and your dew point is not in the negative values, you'll be sorely disapointed as it won't settle.

Correct me IF I am wrong, but if snow falls and your dew point is above ZERO it'll simply melt the moment it touches the ground, and I can't recall a year when the dew points have remained under Zero in October during daylight hours (with the exception of the mountains and highest peaks in England) ??

To sum up there's very little point in getting excited about the prospect of snow fall in October unless you happen to live on a hut on the top of a Mountain

[Snowmadsam]

Why, Ohh Why Ohh WHY are people looking for snow in the charts in October ??

Do me one favour ..if you DO see snowfall in a chart deep into FI ,(In October) then try also to look at the dew points for that same day , basic rule of thumb is thus...if you see snowfall being predicted and your dew point is not in the negative values, you'll be sorely disapointed as it won't settle.

Correct me IF I am wrong, but if snow falls and your dew point is above ZERO it'll simply melt the moment it touches the ground, and I can't recall a year when the dew points have remained under Zero in October during daylight hours (with the exception of the mountains and highest peaks in England) ??

To sum up there's very little point in getting excited about the prospect of snow fall in October unless you happen to live on a hut on the top of a Mountain

Its all a bit of fun we don't go stir crazy yet.....

SAMS 1000TH POST WAS HERE

Edited October 7, 2012 by Stormmadsam

[Thundery wintry showers]

Widespread falling and lying snow is possible in October but is pretty rare. The 28th October 2008 was the most outstanding recent example, as a trough moved in from the NW and brought sleet and snow showers and some longer outbreaks of wintry precipitation, accompanied by thunder in some places, and some parts of the Home Counties had two or three days with lying snow. Around the 20th October 2010, sleety showers affected eastern coastal areas as far south as Scarborough with a dusting of snow for Aberdeen.

However, other than that, lying snow in October has been very rare. In 1993 the Aberdeen area had a snow cover on the 16th, and in 2000 parts of Lancashire and Yorkshire woke up to a snow cover on the 30th, but as a general rule October northerlies bring mainly rain showers at low levels with sleet and snow over the hills.

October snowfalls were more common in the 19th century. When I trawled through the synoptic archives at Wetterzentrale I found about half a dozen years when the -5C 850hPa line was well south around the 11th October, and I remember reading that lying snow was widespread over Cumbria on the 11th October 1896 with thundersnow at Dartmoor. Statistically though lying snow at low levels has always been rare except near the end of the month.

[SMU]

Morning All-

I continue to be very optimist around Winter- we have another 3 & a bit weeks - Post that the patterns that are infront of us are beginning to set in for Winter-

Irrespective of what the models try to show post 192 we SHOULD be seeing the polar front expanding now & produce a sinuous jet around 60N with minimal interuptions, The latter part of October should be the time when the zonal jet is the Strongest with the Mean across the month at around 35 m/s across the atlantic-

Seen here-

& 500 MB mean-

This is not the case this year in OCtober- we are at the other end of the scale with the jet having no energy-

Look at the blocking & splits in the PV for 7 days time

http://www.meteociel.fr/modeles/ecmwf/runs/2012100700/ECH1-168.GIF?07-12

We see the fledgling polar vortex shunted right over to Eastern Russia & into the pacific- Its trying to migrate East across canada, however is coming up again repetative blocking & ridging in the Northern atlantic towards greenland-

Ring any bells?- This is exactly where the greatest SSTA is in terms of plus anomalies-

At the moment we are really seeing the outcome of that weak thermal gradient & a weak jet.

The net of all that is a wall of blocking & semi stagnent air developing over europe-

Its not the right time of year to have a BIG effect on the UK, however the CET for us has a lot higher chance of being below normal.

*IF* we continue to see this blocking through October & into November when the stratosphere really cools then thats the strongest real time signal for this forthcoming winter-

S

[Trickster]

Think the last 2 runs of the CFS shows how much it can flip between runs. Everything up in the air, but CFS has shown a bitter winter on several runs. Trending is the thing to look for. Would be interesting to see the average for the last 4 runs. Maybe that would give us more of an idea

[bluearmy]

steve, that was my point this morning re SST's to our north. the jet has been unable to overide weak ridging to our north and northeast all through september. the best winter sypnotics for snowfall come about when atlantic systems cannot make ne progress against what looks to be weak ridging but actually turns out to be very effective at pushing the jet se. your word 'stagnant' is a good descriptive one re what is currently developing. lets hope a cold strat signal doesnt take control and kick start a more mobile environment.

[gottolovethisweather]

Look at the blocking & splits in the PV for 7 days time

http://www.meteociel...1-168.GIF?07-12

The net of all that is a wall of blocking & semi stagnent air developing over europe-

S

I really ought to know, but what do those numbers represent on the link you provide, are they mean Air pressure readings? Your third attachment also shows quite different readings, which I can understand, with deep lows and high highs.

Anyway, I agree largely with what you say, so fingers crossed that there could be some surprises along the way and we may start edging ever nearer to a cold autumn, yet alone winter.

Edited October 7, 2012 by gottolovethisweather

[johnholmes]

Hi all,

Snow is one of the most difficult, if not the most difficult element to forecast in the UK, so I've done a guide/tutorial just explaining some of the most important things to look out for if you want to know whether its going to snow or rain;

http://www.gavsweath.../snowwatch.html

Hope your enoy it and I hope I've explained everything OK.

Many thanks.

hi Gavin

I am sending you a pm but hope you don't mind me adding this link for folk to have a read of, in the Net Wx Guides

http://forum.netweather.tv/topic/27989-how-to-try-and-forecast-snow/

By the way the video is overall a nice and easy to undstand explanation and keeping it simple should help newcomers start to get a grasp of the compexities of predicting snow.

[johnholmes]

I really ought to know, but what do those numbers represent on the link you provide, are they mean Air pressure readings? Your third attachment also shows quite different readings, which I can understand, with deep lows and high highs.

Anyway, I agree largely with what you say, so fingers crossed that there could be some surprises along the way and we may start edging ever nearer to a cold autumn, yet alone winter.

one is for 14 Oct and the other is 24 hours later?

The numbers are spot pressure values, the white lines being the isobars?

does that help?

[SteveB]

Just out of interest, but has there ever been an Autumn/winter were each month has recorded below average temps?

[gottolovethisweather]

one is for 14 Oct and the other is 24 hours later?

The numbers are spot pressure values, the white lines being the isobars?

does that help?

Hi John,

Spot pressure values meaning readings from specific locations? I have seen these charts before but never asked for more info, well at least, I was interpreting them correctly. I must say I prefer the charts which produce an actual analysis of where the synoptics are trending at a given time, that way makes more sense to me.

Maybe, I need a read of those netweather guides too.

Edited October 7, 2012 by gottolovethisweather

[Methuselah]

Think the last 2 runs of the CFS shows how much it can flip between runs. Everything up in the air, but CFS has shown a bitter winter on several runs. Trending is the thing to look for. Would be interesting to see the average for the last 4 runs. Maybe that would give us more of an idea

Yes, indeed. To be honest, I often wonder why everyone puts quite so much faith in what the CFS comes-out with, as it would appear we do...If it really were 'that good' it would continually surpass the success-rates of all the other models. thus rendering them all obsolete...

[UV-RAY]

Yes, indeed. To be honest, I often wonder everyone puts quite so much faith in what the CFS comes-out with, as it would appear we do...If it really were 'that good' it would continually surpass the success-rates of all the other models. thus rendering them all obsolete...

Indeed RP, I've never placed any faith in the CFS no matter what it shows, and the updated 2 version looks no better than the previous one. Until it starts to show a little more consistency then it's one for mild amusement for me.

[johnholmes]

Hi John,

Maybe, I need a read of those netweather guides too.

you took the words right out of my mouth!

Please pm me if you have any questions after reading any of them. If I can't answer you I can usually point you to someone who can?

j