scotland Scotland Regional Weather Discussion 07/01/14

[Ravelin]

All looking good on the models front, which although its exciting, can also be worrying too. From an IMOBY perspective, as LS alluded to in his post-pub-post, I hope it's more E or NE flow than a SE flow. With the latter there's too much North Sea and around here we tend to end up with cold rain/sleet rather than anything more interesting. Lets hope it doesn't all fall apart and I'll be digging out the car next week rather than digging out my helmet for the Model Thread implosion.

 

Back to the current, and it's a decent morning with only a little cloud around and not too much of a breeze. Temperature is a bit funny. At 7:30am at home it was 2.1C, the low point for overnight and the lowest in a while. By the point I was leaving the house at just before 9am it had risen to 6.0C, quite a rise given the sun was still below the horizon and there was little wind. As I drove to work it dropped from 6C in Kemnay to 3C at Kintore and then climbed gradually back to 6C as I approached Dyce. Must have been some warm/cold pools of surface air sitting around.

[Ravelin]

I shall not be getting too excited untill i see white stuff falling from the sky......us Aberdeeenshire folk (Rav that includes you) have been disapointed too many a time lol but much more promising than of late.

Yep, although with Kemnay being that bit more inland it can easily sit 2-3C below the temperature nearer the coast, especially in lighter winds. Been plenty of times when there's been little or no snow at my work in Dyce but there's been several inches in my back garden at home (admittedly that's north facing and shaded by the house all winter).

 

As I alluded to above, N or NE flow seems to be the best for this area, E is OK if the uppers are good. SE usually ends up in disappointment.

[snowy owl]

Amazing charts, off the check out the MT.

 

Sun is shining, already feels cooler today in the brisk wind.

 

Laptop has broke, smells of burning !(eek) such bad timing, need to nip out and see if i can get it fixed. Will need it for model watching.

[Hawesy]

As I alluded to above, N or NE flow seems to be the best for this area, E is OK if the uppers are good. SE usually ends up in disappointment.

 

Nicely put. I've yet to see a SEly flow bring any significant wintry weather here (mind you the same might be said of most other wind directions for my location!). A long fetch over the North Sea and we're looking at damp and dull and 3/4c by night and day.

 

Don't want to dampen anyone's enthusiasm, but if you live near the east coast at all I would retain a healthy scepticism at this stage! 

[blitzen]

I must be reading the charts wrong (again) as I don't see where any 06z 'downgrade' is? To me, there are slider opportunities being taken which has increased the flow from the east?  Not as cold earlier on, but still cold a bit later

and the  opportunity is definitely there for convection to our eastern shores?  6z then 00z.  Anyone?

Edited January 8, 2014 by Blitzen

[LomondSnowstorm]

I must be reading the charts wrong (again) as I don't see where any 06z 'downgrade' is? To me, there are slider opportunities being taken which has increased the flow from the east?  Not as cold earlier on, but still cold a bit later

and the  opportunity is definitely there for convection to our eastern shores?  6z then 00z.

It's not really a downgrade as such, more a slight delay in the coldest uppers arriving. Once we get to this point, with the trough negatively tilted against the block, all roads should lead to an easterly. It's just a question of whether that's on Monday night or Thursday after some marginal sliders:

[November13]

I agree I think we are due an Easterly blast next week looking at the charts. There was a mention of wet snow for the borders tonight. Will need to keep an eye on this.

[tiff]

Yr.No Says snow for me Monday and Tuseday. Bring it on!

 

 

YAY

Edited January 8, 2014 by tiff

[Scottish-Irish Skier]

No here, still in Londonshire, and going to be the same for the next 4 weeks, with only weekends at hame. 

 

You should be happy with a cm then. That's loads down there. Equivalent of a ft in Scotland.

Edited January 8, 2014 by scottish skier

[LomondSnowstorm]

I agree I think we are due an Easterly blast next week looking at the charts. There was a mention of wet snow for the borders tonight. Will need to keep an eye on this.

 

Looks like it might just about creep over the border and no more:

Thicknesses a bit meh:

950s only briefly conducive:

You'd be pretty lucky to see any snow tonight this side of the border, or even in Northern England away from the tops of the Cumbrian Fells.

[edo]

Good looking charts...gonna be plenty to go through on here tonight on my new all in one PC with touchscreen and windows 8 (thanks to the kids for breaking the laptop and causing the requirement for a new bit of tekkers)...makes looking at differences in charts so easy on the split screen facility and helps to compare the excellent explanations on here...

 

Jetstream looking promising

Edited January 8, 2014 by edodfc

[shetland islands]

The potential colder spell is still low confidence and therefore needs to be treated with caution until further runs confirm a patter change.

[NUT]

Looks like there's 1 little shower right now in the central belt...........Guess whose under it

[snowy owl]

NUT its the same here - one huge black cloud! lol

[Buriedundersnow]

Definitely worth coming out of hibernation for

 

 

welcome back CATCH looks like your just in time to see if your new dwelling is any good for snow or will you be stuck in a slushfest like me lol

[Buriedundersnow]

I already know the answer to that one BUS. I'll only be getting proper snow if everyone is getting it, there will be no repeat of last winter

 

 

i'll put money on it i'll still be the last to see any snow sticking its always the same here with phantom warm layers and such but I am sure we will find out over the next week or so or if we are lucky right through spring.

[Buriedundersnow]

The potential colder spell is still low confidence and therefore needs to be treated with caution until further runs confirm a patter change.

 

 

I think we will see the cold come in just how long it stays is the question mark but we should at least see something.

 

see your a new member last night well welcome to the Scottish thread and hopefully you will enjoy joining in with the kilted bunch in the chase for the white stuff then posting pics of the tremendous scenes when it does come.

[jon_d1983]

i'll put money on it i'll still be the last to see any snow sticking its always the same here with phantom warm layers and such but I am sure we will find out over the next week or so or if we are lucky right through spring.

 

If anyone deserves some snow its you BUS!! surely skadii teh snow goddess will drop some off you!

[LomondSnowstorm]

Everything's backing west the closer we get:

 

7th Jan FAX 00z +96hrs.gif8th Jan FAX 00z +84hrs.gif

 

That second chart is pretty interesting (the more recent one) - sub 528 thicknesses with troughs coming in from the west on Saturday means decent snow potential. EURO4 has precip charts back again so might be a good wee test of the mesoscale models before the real stuff hits.

[Buriedundersnow]

If anyone deserves some snow its you BUS!! surely skadii teh snow goddess will drop some off you!

 

 

aye well heres hoping but sadly never works like that for me hopefully this is the winter i'll see an epic streamer set up off the forth and pummel me but cant see it

[Buriedundersnow]

That second chart is pretty interesting (the more recent one) - sub 528 thicknesses with troughs coming in from the west on Saturday means decent snow potential. EURO4 has precip charts back again so might be a good wee test of the mesoscale models before the real stuff hits.

 

 

UKMO also has decent uppers out west at 72hr so that -6 air will prob be rolling through

 

[Buriedundersnow]

wee question for you LS as I have only been following models for a short time.

 

I have heard you and others say the models struggle with heights to our north or north east and cant model it correctly well what we are seeing in the models with the high sinking is this a normal thing for the models and we will see this continue but as it gets closer in the models will keep it up there or is the models wanting to constantly sink it meaning we will see it sink at some point.

 

ie will we still always see it try and sink till the models work out another slider low to prop it up.

Edited January 8, 2014 by Buriedundersnow

[LomondSnowstorm]

wee question for you LS as I have only been following models for a short time.

 

I have heard you and others say the models struggle with heights to our north or north east and cant model it correctly well what we are seeing in the models with the high sinking is this a normal thing for the models and we will see this continue but as it gets closer in the models will keep it up there or is the models wanting to constantly sink it meaning we will see it sink at some point.

 

ie will we still always see it try and sink till the models work out another slider low to prop it up.

 

A lot depends on the upstream pattern - the models generally have been a bit too flat for troughs going through the US, particularly the GFS - if it's more amplified then we'll be able to get WAA up into Greenland which will in turn deflect the jet southwards and allow our ridge to ridge westwards.

The reason the high sinks in FI is because the PV backs eastwards from Canada to Greenland, which pushes the jet energy over the top of the block and causes it to sink.

Without the heights extending to Greenland this is pretty much inevitable, although we could end up with a mid latitude high which just gives us a settled, cold and dry period. The best example of this extension comes from the GEM - the low exiting the US is sufficiently 'vertical' to draw the Azores heights northwards and extend the Scandi heights northwestwards:

This then deflects the next low under the block and at that point it's a long long way back to westerlies.

January '47 was about as long a period as you get generally with an easterly sustained without any real extension westwards.

Massive Siberian ridging sets up on the 20th:

We get an easterly but it's generally a bit flabby:

Fortunately, the upstream trough on the chart above is negatively tilted so the trough disrupts (i.e. the jet splits) sending energy under the block:

The vortex gradually weakens before the high sinks fully, with a strong Euro trough propping the flow up:

The Azores high is the saviour, deflecting the weakened jet SEwards under the block around a very flimsy looking Scandi high:

A protracted battleground with the troughing sliding under a giant but pretty weak Siberian high ensues until finally a Greenland high just sort of appears, with the vortex completely shot to hell by this point:

Bit of a freak synoptic event which you'd struggle to replicate and still keep us on the right side of marginal, but quite probably SSW driven (I believe the data only goes back to 1955 so we don't know for certain but it'd be hard to imagine that kind of disruption without a complete reversal up top). Obviously our PV at the moment is in healthier shape and it's only the wave 2 action which has brought about a temporary split, which appears as though it will work out incredibly favourably for us in basically 'rolling a 6' at the first attempt. Therefore, we really need something favourable to happen upstream to stop the next low barrelling in because, while the PV is weakening, it hasn't (yet) had that knockout blow which would stop any chance of zonality returning. Basically, look for weak, slow and vertical lows over the eastern US around +168 for the easiest route to a continuation of the cold.

[Buriedundersnow]

Joe Bastardi â€@BigJoeBastardi 2h

Winter coming for Europe. Day 10-15 temps pic.twitter.com/urRy1tJDEI

 

 

[LomondSnowstorm]

 

Joe laminate floori â€@BigJoelaminate floori 2h

Winter coming for Europe. Day 10-15 temps pic.twitter.com/urRy1tJDEI

 

Bddci18CYAAA4n0.jpg

 

 

Exceptional, mean temperatures easily sub 0C for most of Scotland on that for Days 10-15 when it's 'meant' to be getting more zonal - suggests either very cold HP or proper retrogression (as highlighted by GEM in post above). Some brutal cold in there: