735 replies to this topic

[over_the_rainbow]

Certainly makes for fun model watching and let's hope we all get something up our end!

[scottish skier]

over_the_rainbow, on 07 January 2012 - 20:17 , said:

Certainly makes for fun model watching and let's hope we all get something up our end!

Aye, was just in there the now and it's all quite positive for the moment.

I think we can satisfy ourselves that as we move though january we will see a pattern change; lots of support for it. What that ends up giving is unknown, but anything is better than repeats of bawbag after bawbag!

[LomondSnowstorm]

Cheggers, on 07 January 2012 - 13:59 , said:

Fairly blowy and showery Forres. Temp @ 6c and the showers are fair rattling through. Any update on last nights Bawmegeddon LS posted?

Rest easy fellow house dwellers - bawmaggedon is off the table. Unless you mean snowbawmageddon....

Edited by LomondSnowstorm, 07 January 2012 - 21:12 .

[A Scottish Winter's Tale]

Can someone clarify the following:

1)Where we can find the models that are showing the easterly
2) At what time is the easterly present
3) What would it mean for Scotland

One particular chart that I saw showed Scotland under High Pressure with few isobars (all far apart). Do the isobars need to be closer for North Sea convection? I also read a post from kold weather that what the charts are showing for Scotland would be close call with that easterly. As there's very little Scots on the model thread I and many other members aren't sure about what it would mean for us? Still that particular easterly may never happen but atleast it's a start and hopefully throws up many other oppurtunties for the rest of our winter.

[NorthernRab]

Campsie Snow Storm, on 07 January 2012 - 22:01 , said:

Can someone clarify the following:

1)Where we can find the models that are showing the easterly
2) At what time is the easterly present
3) What would it mean for Scotland

One particular chart that I saw showed Scotland under High Pressure with few isobars (all far apart). Do the isobars need to be closer for North Sea convection? I also read a post from kold weather that what the charts are showing for Scotland would be close call with that easterly. As there's very little Scots on the model thread I and many other members aren't sure about what it would mean for us? Still that particular easterly may never happen but atleast it's a start and hopefully throws up many other oppurtunties for the rest of our winter.

It's still too early to say as the models constantly flip around at this time frame, but expect colder weather to have arrived or not to be too far away by around the 18th-20th of January. Furthermore, we are forecast to see a large SSW (sudden stratospheric warming) in approx 9-11 days time which can disrupt the polar votext and lead to colder weather anything from a week to four weeks after the event has taken place.

In summary, our best shot at cold weather is likely yet to come during the last third of January and the month of February, it's just not very clear how it will pan out at all, it could be a lot more northerly than easterly in nature than is being suggested at the moment, but like I said we'll need some cross-model agreement.

Hope that has sufficiently muddied the (hopefully soon to be frozen solid) waters

[LomondSnowstorm]

Campsie Snow Storm, on 07 January 2012 - 22:01 , said:

Can someone clarify the following:

1)Where we can find the models that are showing the easterly
2) At what time is the easterly present
3) What would it mean for Scotland
One particular chart that I saw showed Scotland under High Pressure with few isobars (all far apart). Do the isobars need to be closer for North Sea convection? I also read a post from kold weather that what the charts are showing for Scotland would be close call with that easterly. As there's very little Scots on the model thread I and many other members aren't sure about what it would mean for us? Still that particular easterly may never happen but atleast it's a start and hopefully throws up many other oppurtunties for the rest of our winter.

1) http://hw.nwstatic.c.../ecm500.216.png Let's be honest here - it's not technically an easterly here and the PV to the northwest looks a tad strong to allow it develop on that particular run. My ramping isn't based on solely on the latest model output, nice though it might well be
2)8-10 days out, most likely later than that to be honest before the cold properly starts to take hold
3)As modelled by the ECM, very little, since the flow is essentially southerly. Ramping SOLELY about those charts should be confined to southeast dwellers - we'd get more snow out of yesterday's GFS runs than this. However, it's all about the bigger picture, and that chart is a step in the right direction by the models towards a first outbreak of cold. Note that even if it isn't successful, the SSW forecast should ensure that there is at least one much better chance for prolonged cold than this.
If it upgraded slightly i.e. had at least southeasterly winds, then you're absolutely right that convection would be dependent on uppers being below -7/-8C and inland snowfall dependent on more tightly packed isobars i.e. stronger winds. It's too far out to speculate at this stage - just think of it as a precursor to something potentially much more substantive....
edit: I see Rab beat me to it

Edited by LomondSnowstorm, 07 January 2012 - 22:18 .

[NorthernRab]

Yes LomondSnowstorm is bang on - I suppose you could say we have the chess board and many of the pieces, but the game isn't set up yet, we're not certain that we actually have the queens or the castles and we're undecided as to when exactly we'll be playing. In short, it's all looking very promising but we're really looking for a more north-easterly flow to allow for heavy snowfalls so fingers crossed!

Edit: Above is possibly the most pompous thing I've written in a long time!

Edited by NorthernRab, 07 January 2012 - 22:33 .

[LomondSnowstorm]

Getting closer..... http://hw.nwstatic.c.../h850t850eu.png
Think we maybe found a pawn there
edit: About to jinx it but this pub run looks like turning into something pretty damned fantastic.
edit 2: Just a few hundred miles too far south initially. Going to turn out nicely to end though surely..

Edited by LomondSnowstorm, 07 January 2012 - 22:43 .

[A Scottish Winter's Tale]

The latest run was quite good, especially for Shetland where there is a raging easterly at around 276hrs

And in parts of the Arctic circle the uppers are going above 0C and we're very close to getting a beasterly at 324hrs.

The PV is taking a hit. That was the best run of the winter so far as we came close to a decent easterly with Shetland benefiting greatly. Further south, the mood would have dimmed somewhat but I have to say that I'm surprised at how decent that run was and it carries on the theme of a weakening PV, a developing cold pool over Europe which we might end up in.

[LomondSnowstorm]

A bit of a messy setup and not exactly ideal but if we get to here by the 23rd I'll be bouncing off the walls http://176.31.229.22...18-0-384.png?18 Just one run though, the pub run, and I know we're all mature enough not to get overly excited about what are still FI charts but for once the background signals and the model runs are beginning to agree quite nicely....

[A Scottish Winter's Tale]

EDIT: At the very end of the run, the entirety of Scotland is under an easterly!

LomondSnowstorm, on 07 January 2012 - 22:48 , said:

A bit of a messy setup and not exactly ideal but if we get to here by the 23rd I'll be bouncing off the walls http://176.31.229.22...18-0-384.png?18 Just one run though, the pub run, and I know we're all mature enough not to get overly excited about what are still FI charts but for once the background signals and the model runs are beginning to agree quite nicely....

Yes, it's improving run after run so there is a real trend there. But the positives to take from the pub run is that at the end it does show Scotland under an easterly for the first time this winter; the PV looks like it's going; there's a great cold pool over Europe; it seems that the cold air is flooding further south and west and we may tap into it; and this is all before the end of January too!

[A Scottish Winter's Tale]

I feel like doing a fantasy island analysis!


Cold pool over Europe, warming further north, 1032mb over N Scandi



The cold pool decided to try and visit us. Look at the trail of green to the north. High pressure over Scandi.



Unfortuantly, despite the Scandi Hi and warming Arctic, an area of low pressure tries to stop the approaching big freeze. As a result, Shetland gets a raging SEly.




The battle between the low pressure and big freeze continues resulting in a beasterly for Shetland and lots of snow.




The cold pool remains intact and is still willing to say hello.



Suddenly, we have a breakthrough with low pressure to our south a Scandi Hi, Higher Pressure over Greenland with PV weakening and of course an easterly for much of Scotland.






Final chart. All of Scotland under an easterly and -6C uppers. -10C uppers at Shetland. Scandi Hi, low pressure to the south. Lots of greens near Greenland with 1024 mb and still 35 days of winter left after this.




BINGO!

[LomondSnowstorm]

One thing to bear in mind is that the first attempt at setting up an easterly is often unsuccessful. For example, in December 2009 we had a similar 'will it won't it' situation and the first easterly progged eventually downgraded to nothing. Not that it mattered by that point because behind it was something much more promising. Equally there have been fantasy easterlies that came to nothing - http://91.121.94.83/...18-1-300.png?18

But all the same, Steve Murr just got the '47 charts out and I have to say it was a shame most datasets don't go back that far otherwise it may well have had merit as an analoguous year (mid january flip, weak la nina(?))

Edited by LomondSnowstorm, 07 January 2012 - 23:27 .

[A Scottish Winter's Tale]

LomondSnowstorm, on 07 January 2012 - 23:16 , said:

One thing to bear in mind is that the first attempt at setting up an easterly is often unsuccessful. For example, in December 2009 we had a similar 'will it won't it' situation and the first easterly progged eventually downgraded to nothing. Not that it mattered by that point because behind it was something much more promising. Equally there have been fantasy easterlies that came to nothing - http://91.121.94.83/...18-1-300.png?18

I remember that after last winter's big freeze, there were many great easterlies around, particulary in February!

I'm not going to get too excited too yet but there's quite obviously a trend towards a Scandi Hi, weakening PV, maybe even a Greenie Hi (ramp).
And most importantly, it looks likely that there's going to be a cold pool over Europe, it's just a question of when we will tap into it.

As the latest run showed, it had one attempt to say hello, never gave up and had a back-up plan that succeeded. With the expected SSW and the likelyhood of a colder Europe then I would imagine that perhaps there will be many more attemps from the cold pool to swallow us up. I believe that once the cold pool is instore, and the SSW, a greenie hi or scandi hi is possible and with a lot of winter left it remains possible for us to at least a few more attempts before finally being put into the freezer.

I'm feeling very confident as whatever happens this week or next week, there's a lot of winter left, there's a predicted SSW, possible height rises over Scandi and Greenland, a cold pool to our east, decent models and lot of time left for us to eventually end up in the freezer.

Also, when is the next run?

[LomondSnowstorm]

The 18Z ensembles tonight are a complete shambles http://www.meteociel...=0&type=1&ext=1
That's the air pressure for northern Sweden. Very limited model support for the Scandi High at all. So, which is it - the ensembles or the GFS and ECM? I'm tempted to bin the ensembles because a) it's the easier choice and an overpowering PV just makes no sense at all given the strat. picture. So we'll go with that, until the 00Zs come out with raging zonality and a Bartlett

[lorenzo]

Wow, you go out for a few hours and look what happens .Amazing charts, everything has gone off on one.

Spectacular changes all over FI runs, very easy / easterly on the eye.


Mashed Vortex.

Then GFS and ECM both calling this set up..


Must admit I never expected the pattern to accelerate to change that quickly, so am looking on these with caution. The main thing here is that the PV takes an almighty hit. Looking more like disintegration vs displacement. Great to see that flat Jet carved to bits.

Ensembles also looking good - this is for Aberdeen approx location.


Looking this evening that the bundles of patience shown will be worth it !

[A Scottish Winter's Tale]

So, without any hmmms, buts, ifs and maybes, what is everyone's actual opinion about what the latter part of January and Febuary is going to bring.

So, out of 100, what are your odds on a decent cold spell sometime this winter (a cold spell lasting at least 5 days, bring some snow and low temps to everyone).

I'm going for 68 in favour of a decent cold spell and 32 not in favour.

And the predicted cold spell if it come off out of 10. I'm going for 8/10 during the second week of February.

[NorthernRab]

Campsie Snow Storm, on 08 January 2012 - 00:23 , said:

So, without any hmmms, buts, ifs and maybes, what is everyone's actual opinion about what the latter part of January and Febuary is going to bring.

So, out of 100, what are your odds on a decent cold spell sometime this winter (a cold spell lasting at least 5 days, bring some snow and low temps to everyone).

I'm going for 68 in favour of a decent cold spell and 32 not in favour.

And the predicted cold spell if it come off out of 10. I'm going for 8/10 during the second week of February.

Of all my years of model watching, I've got to say it's never ever going to be that clear cut. I'll give percentages for the sake of interest, but they are only an estimate at best. Odds of a cold spell in Scotland between now and mid-March...I'd say 90/100, perhaps higher. Do remember that we're actually a North Western European nation and seeing as the Arctic is actually its coldest in late Feb / early March, northerly outbreaks really can deliver late in the season (March 2006 anyone?). Of a decent cold spell, perhaps as high as 80/100 given the very impressive SSW that is forecast to take place around the 17th of January, perhaps a little bit lower / higher depending on what the models show over over the next couple of weeks.

It really is so difficult to give probabilities with regards to snow and cold, but I really am confident of a cold spell at some point over the next two months. I'll give a more in depth analysis tomorrow.

[Cheggers]

Cool, grey and breezy here in the wilds of Moray. Will be heading doon the A9 later today, might take a few snaps around Drumochter if light permits.

[Hairy Celt]

Cheggers, on 08 January 2012 - 10:14 , said:

Cool, grey and breezy here in the wilds of Moray. Will be heading doon the A9 later today, might take a few snaps around Drumochter if light permits.

Cool? Nah, this is 'mild'! 7C here anyway. Grey but little wind & the odd spot of rain.