Snow Watch: Scotland

[BlizzardConditions]

Just been checking out the ski cams - where have the mountains gone?

http://www.winterhighland.info/testcam/ssc.jpeg

White Lady is a bit of a white out:

http://www.winterhighland.info/testcam/lady.jpeg

Ok, what about out the window at the Ptarmigan restaurant:

http://www.cairngormmountain.co.uk//webcam/ptarmigan.jpg

Hmm....

Excellent pics there except the last one - I think you just coloured that in white

[Mondy]

The front is steaming in:

Check sat24 before it gets too dark..look at the northerly airstream about to collide with the front..gonna be a mess soon, and somebody will have to clean it up

Edit: Keep an eye on the Irish threads soon..the cousins over there will be able to let us know what conditions they're getting

Edited February 7, 2009 by Delta X-Ray

[glasgow-guy]

met-office updated much of southern and eastern Britain Monday downgraded

Edited February 7, 2009 by glasgow-guy

[Graeme B]

Oooph - I want to be under that when they meet..

Edited February 7, 2009 by dexter

[glasgow-guy]

as i thought looks like some in Glasgow will be disappointed sat into sun

[Graeme B]

That's a big upgrade from the Meto....

[LomondSnowstorm]

At the moment the Met Office Advisory looks as if the snow will get trapped behind the Ochils and will not affect Fife. Lets hope that this system has enough oomph to push its way fully across and out into the north sea.

i've not seen that happen to many atlantic fronts and anyway, surely it will come in from a southwestish direction as it approaches

it's hard to tell from the cloud whether it's rain or snow, all we can do is look at the temps and dew points closer to the time

That's a big upgrade from the Meto....

i think its for ice tonight

they haven't updated our snow advisories as far as i can see

[sammie]

i think its for ice tonight

they haven't updated our snow advisories as far as i can see

Aye they haven't really touched the snow advisories, there more worried about the ice.

[Gilly]

Thanks Delta X-Ray that Satellite pic shows a very hefty front which is about to hit west of Ireland and could reach central Scotland over night or very early morning IF it gets through and doesn't get blocked over Ireland!!!

As Dexter says

Oooph - I want to be under that when they meet..

[LomondSnowstorm]

Hey cwpiper - just curious as to where you seen this mate? Was it the TV forecast? Just wondering as the BBC site only has a warning out for Central and Northern England despite the fact the MO has one for Southern Scotland too!

tv forecast seems to show the brunt of it hitting eastern scotland sunday/monday

[stuart316]

So, in layman's terms, is there a lot of wet stuff heading our way over the Atlantic?

Could it be possible that the West Coast is going to be affected by this precipitation?

Could it be possible that it's cold enough for this precipitation to fall as snow?

Although clearly there is a danger that temperatures will increase too much as the front approaches?

Edited February 7, 2009 by stuart316

[LadyPakal]

Some more webcams - Nevis, low level Aviemore plus a host of links to other mountain webcams.

http://www.mountainspirit.co.uk/info/cairngormcams.asp

Skiers doing their thing at Cairngorm:

http://www.cairngormmountain.com/webcam/ba...y=1234023590269

[sammie]

So, in layman's terms, is there a lot of wet stuff heading our way over the Atlantic?

Could it be possible that the West Coast is going to be affected by this precipitation?

Could it be possible that it's cold enough for this precipitation to fall as snow?

Although clearly there is a danger that temperatures will increase too much as the front approaches?

From what I gather, big blob of rain coming towards big blob of cold air should = snow.

I thought the danger in increasing temps would have been after the front passes, since the new air mass should be behind the front?

[Mondy]

The temps on the west coast of Ireland are already a good indicator. Max temp 6 with a dew point of -3c over there. I reckon it will probably be sleet then rain for those parts. As you move further inland, and with temps expected to drop below freezing tonight, the front will come up against the cold air and my hunch is that snow will fall. The front is massive still, so if could be be over us for hours tomorrow - but will it snow for hours too?!

[shuggee]

It does look like a whopping front. Here's how the 12z GFS handles it:

By 18h00 tomorrow here is the profile of the 850 temps and precipitation. Remember -5ºC and below at the height of the 850 temps (about 1500m up in the atmosphere) is an approximate yardstick for the difference between rain and snow:

Now a focus 6 hours later at midnight Sun/Mon.

Here's the 850s and precipitation again:

So borderline for the central belt - better in the east than the west. And of course the likes of Fife/Stirling/Perth/Dundee looking good.

Here's a different chart than I'd usually use to look at the ground temps. This is the average temp at midnight - a blend of the maximum and minimum temps at that time. Will be interesting to see how this verifies:

And dew points (remember if it's zero or below than it's more likely snow). And now I'm poet too:

So looking good for most of central Scotland there. Next is the zero degree isotherm (the height at which the air temp is at freezing point above the ground):

Again around 100/200m in most central population centres. Borderline again for the west - better in the east and better still north of the Forth.

Snow risk and snow level chart at midnight:

Worth a look at the winds at midnight too. As you can see across Central Scotland, the area of low pressure seems to be smack in the middle of the Central Belt, say over the eastern suburbs of Glasgow.

I'd suggest that if you are to the north and east of that the likelihood of seeing snow is increased than if you are to the south or west. Ideally for us in the Glasgow or Edinburgh areas - if the track of that low was, say, 50-100miles further south, this would be a much more confident forecast of snow for those two cities.

Finally here's the 850 temps and precipitation for 12midday Monday:

The cold air comes back over Scotland and there's still a hangover of precipitation (very likely snow) for The Kingdom, central eastern Highlands, Angus and Aberdeen.

For me, the intensity of the precipitation will likely decide what is seen in the central belt tomorrow evening. As Mondy is showing with the satellite shots - this is a hefty front. I'm thinking that the precipitation amounts indicated on the GFS charts are underplaying the intensity and amount of what will actually fall. If I'm right - many more of us could see snow than I've indicated above

[LadyPakal]

So, in layman's terms, is there a lot of wet stuff heading our way over the Atlantic?

Could it be possible that the West Coast is going to be affected by this precipitation?

Could it be possible that it's cold enough for this precipitation to fall as snow?

Although clearly there is a danger that temperatures will increase too much as the front approaches?

Looking here:

http://www.xcweather.co.uk/

The west coast (Ireland & some Scottish islands) temps seem a bit high for snow right now. Scotland mainland west coast is ok right now - with night coming it may drop a bit more there before the front arrives, we'll have to see if the temps rise with the arrival of the front. Subzero temps already heading down from the north to the central areas. A whole heap more snow for the ski resorts coming...

I remember the big front that came over (early Dec I think), Aberdeen was meant to see snow, then to rain, then maybe back to snow. As it happens it stayed as snow all the way through and we got quite a dumping.

[Gilly]

Thanks Shuggee..........that is really helpful, explains a lot.

[glasgow-guy]

well that easterly that came in on Monday blanketed most of the central belt good chance it will this time around

[East Kilbride Blizzards]

It does look like a whopping front. Here's how the 12z GFS handles it:

By 18h00 tomorrow here is the profile of the 850 temps and precipitation. Remember -5ºC and below at the height of the 850 temps (about 1500m up in the atmosphere) is an approximate yardstick for the difference between rain and snow:

<snip>

You got also take a note that the front is weakening as it approaches the British Isles, light to moderate snow for most.

Edited February 7, 2009 by shuggee

[sammie]

.

.

.

You are a gem! Thank you very much!

[East Kilbride Blizzards]

Had a few Heavy Snow Showers in East Kilbride this morning.

16:35 GMT:

Temp: 0.3c

Dew point: -4.9c

Edited February 7, 2009 by East Kilbride Blizzards

[glasgow-guy]

Had a few Heavy Snow Showers in East Kilbride this morning.

16:35 GMT:

Temp: 0.3c

Dew point: -4.9c

yes same down here was a fresh dusting dident last long

[Graeme B]

Thanks for that Shugmeister - great post and answers a lot of questions therein....

[East Kilbride Blizzards]

It is possible things could less cold for northern western parts late this week all depends on the models. :o

[shuggee]

You're all welcome. It's looking interesting :o

Forgot to post the computer modelling of the precipitation type at midnight tomorrow night :o