NorthernRab

Light Sneachd just arrived in Inverness!

Very touch and go here I'm guessing, fingers crossed!

Excellent consistency? Eh? It wasn't two days ago that it was showing high pressure!

You'll have a very depressing time of it unless you just accept that it snows more in Scotland, it's just the world we live in. Anyway, considerable snow still there for Monday, excellent for the ski ranges

Believe it or not, the last few winters haven't actually been the best for Highland snowfall, although they have been very cold. Now this is a true Highland blizzard, 1978.

The Northern Hemisphere charts continue (i.e consistent pattern across many runs) to paint a positive picture synoptically, so lots of potential and a very pleasing starting point to winter!

Fort William, that's your idea of the far north, really? -- Looks the possibility of some considerable marginal snow in Scotland come Monday

It is indeed a fact that the models are a lack of considerable cold for the next 10 days, but what they are showing in the later stages very likely is not fact. Crucial difference.

In fairness, this is the model output discussion for the United Kingdom - some considerable snow looks a distinct possbility for Scotland this weekend.

I am truly astounded how many people are putting so much faith in the GFS' handling of the depth a low 120 hours away or so. Once bitten twice shy I'd have thought, but apparently not!

Has there ever not been?

So long as the mid-Northern latitudes continue to spin at a rate of about 700-900mph, we'll always have some form of vortex I'd imagine.

Abair ainm breagha a th'ort - failte gu Netweather Hopefully there'll be many a Snowman for Dublin this winter!

Some bone-chilling cold for us here in the Scottish Highlands suggested next week, just 6pm here.

While it's all doom and gloom on here, the 12z GFS, like the 6z before, forecasts some very good snowfall for much of Scotland. 850hPa temperatures eventually head down towards the -10'C here too.

Just look at that intense cold over Scandinavia, ready to make the hop across the N.Sea to Scotland!

I was very confused as to why a few people were so gloomy on the model thread this morning; I hurried away to check the charts thinking there had been a big downgrade, but it's still looking great! People need to realise that the details will not be firmed up until this weekend at the earliest and even then we'll only be able to tell what the first incursion of cold might bring. So much to play for and bang on time for the start to hopefully an amazing Scottish Winter of 2012/2013!

What unbelievable ramping in the model output discussion thread! Looking really very nice for the start of December though, there is big potential admitidly!

Clear morning, but quite windy. Quite chilly at 1.2'C Dew point: 0.7'C Wind: 11mph Windchill: -4'C

Anyway, ignoring the very nice FI and longer term trend for cold weather towards the end of the month, in the shorter time frame, Sunday looking quite nice for parts of Scotland. The Highlands in particularly look set to experience another brief taste of winter. Cold uppers in a NWrly flow. Surface temperatures around freezing: Decent precipitation looks a possibility: Could be a little bit of surprise snowfall around Glasgow etc, and under 100 hours!

Yes, but it's the blocking we need to consider. It's the context for the cold, the exact set-up of pressure is something you consider closer to the time. Nothing "always mean cold and snow" in meteorology, we wouldn't need this thread if that was the case. Like I said, look at the Northern Hemisphere charts, a disrupted vortex with good heights at the poles = cold air displaced further south, perhaps to our shores. Oh and press both the ctrl key and the = key (two keys to the right of the zero key) at the same time, means you can manually change font sizes quickly. (The minus key beside it will make them smaller).

It's shifted forward though; higher heights at the pole with a more disrupted vortex too.

But none of the models were suggesting cold in the short term? Unless of course you're referring to the last week of November, in which case the fact that the GFS is still showing a disrupted vortex is indicative of the fact that it's still very much all to play for! Take a look at this profile of the Northern Hemisphere: No deep purples over Greenland / no large vortex and a northerly flow across the UK. Not a bad outlook for traditionally one of the most zonal periods of the year!

"If the starting point is lower, i.e making the jump from a cold stratosphere to a warm stratosphere larger, will that encourage more blocking?" is the question I think you're asking here? I.e is it the the amount by which the stratosphere warms or is it how warm it gets that is important? I think the answer is the latter, but I'll leave it for someone else with a bit more experience to answer your question with a bit more detail.

It's not looking THAT bad!