The all new 11/12 Weather Outlook thread

A snowHead

bobmcstuff, snowfall amounts in terms of cms of new snow can give an indication of whether there will be "a lot" or "not so much" snow but are pretty meaningless beyong that

A snowHead

Samerberg Sue, yes. I was agreeing with you. The rainfall was very concentrated. The two precipitation charts above are rolling. Once they get past 11 November the top half will plummet into the red unless there is a lot of rain in Austria between now and 11 November (and there is not much forecast).

bobmcstuff, a large number (most?) of commercial forecasts rely on the operational run of GFS to produce their forecasts. I suspect as I said above that this is the case with wetter.com and know it is the case with snowforecast.com. If you look at the GFS ensembles (there are a whole bunch listed at the top of the previous page) you can see the operational as the thick green line. Beyond about 3 to 5 days the spread of the ensemble runs increases, beyond seven to ten days it normally increases further. The extent of the divergence is an indicator of the confidence you might have in any particular run, the less divergence the greater the confidence. Although for real confidence you would want to see it repeated in run after run and picked up by the other major models (ECM and UKMO, sometimes known as the Euros).

There is no point in looking at different commercial forecasts all run off the GFS operational and using them as corroboration. They are all using the same source information (differences more often than not come from different frequency with which the forecasts update to the latest GFS run).

That isn't to say there is anything necessarily wrong with forecasts using the GFS operational, just that they don't give you much feel for the confidence you might have in a particular outcome.

And like Arno said.

Well, the person's real but it's just a made up name, see?

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I am not going to look at any GFS ensembles before mid-November. If I was going to Tignes in November I would - but for the broad swathe of resorts, and for people going middle December onward, there's not much point.

Anyway, snowHeads is much more fun if you do.

I've been waiting for ages to be able to ask this question and now we're into November I feel within my rights. I'm off to Tignes for a few days on the 10th Nov, can anyone shed any light / hazard a guess as to what's likely to happen between now and then and what may or not be left by the time we get there (I'm hoping for plenty)!

Many thanks in advance.

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The coming weekend it seems that the Pyrenees will have the first dump this season Very Happy

Then you can post your own questions or snow reports...

Arno, nozawaonsen, pam w, cheers guys.

I was just wondering why there were some differences between the two and which was considered more accurate. But if they're both off the same data then it probably doesn't matter!!

I must admit I like to use the snow-forecast one more because it normally says there will be more snow even though that's obviously a stupid thing to do...

Any other good summaries?

After all it is free

Noza. Simples

reded78, being at the altitude it is Tignes looks like it will do quite well out of the rain/snow arriving late Thursday early Friday. Although it's hard to be precise about these things it looks like at least a foot of snow if not more (and could be a lot more on the Swiss/Italian border). Snow line looks like it will be at or a little above resort level.

Temperatures then look dipping a bit overnight Sunday and Monday and possibly some more fresh snow on Tuesday though with a snow line a little higher.

Tignes Meteogram

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nozawaonsen,

Do we think that this snow falling above say 2400 could be the beginning of the upper base layer,temps look like they could remain cold enough for this , plus there looks like there could be more snow later next week, it would be cool to think in 9 weeks time I could be on top of this latest fall !!

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Pretty much as yesterday.

The amount of snowfall at altitude between Thursday evening and Sunday could be substantial in places. Bergfex is suggesting over 2m in Zermatt above 2400m. Whilst I wouldn't be too focussed on the figure that does sound like very heavy snowfall with inevitable high avalanche risk. The equivalent amount of rain falling lower down could cause quite a bit of disruption too.

As temperatures then fall into November it does sound like this could be the start of a good high altitude base in places in the southern Alps. That said I do wonder a little about stability given the large amount of snowfall followed quickly by a couple of sharply colder and clear nights?

By and large the models are suggesting temperatures will fall to seasonal average for the remainder of their runs. Slightly higher than average in the eastern Alps for now. Further east however cold air looks like it will start piling up on the far side of the (still rather persistent) block...

Scotland for now remains on the rather too mild side.

snow reports

Excellent news! Sounds like it could be a good few days.

Thanks Nozawaonsen.

It's only November guys, a few days of warmth will wipe out any early snow.....

You know it makes sense.

Agree - but hopefully not between now and next Thursday!!

Otherwise you'll just go on seeing the one name:

A snowHead

A snowHead

Well, the person's real but it's just a made up name, see?

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North side of the Alps will see quite warm windy weather, the south, mild windy and in the west very, very wet conditions. It really starts in ernest tomorrow though first signs should be apparent tonight.

After this passes through next week will see cooler temperatures (3 to 5 C lower), but still around seasonal average on in the Eastern Alps a bit above (which actually means about the same given that normally the east would be starting to get cooler by now).

And... The Eastern block is still in place... For now...

Anyway, snowHeads is much more fun if you do.

anyone happen to know the GFS location for Niseko ?

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kitenski, not quite sure what you're after? I've not come across GFS ensembles for Japan.

A couple of products which work off the GFS operational run.

WXMaps 10 day temperature outlook East Asia http://www.wxmaps.org/pix/temp5.html

GFS +120 500hPa chart http://www.wetterzentrale.de/pics/Roasavn1201.png

You can play around with the first to get precipitation outlook. In terms of temperature still running a little mild in Japan, but some nice cold air building up over China later in the run.

Again with the second chart you can play around to shift the time, chart, etc.

Then you can post your own questions or snow reports...

Cheers, on a phone do cannot check links yet, but I was basically after wiggles for niseko.....

After all it is free

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stiniog are you from blena ffestiniog as its a welsh quote

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I, m going to la Tania new year, and have promised myself will not panic untii December 21st, I would love to see lots of snow before then but have been gobsmacked to many times when I've thought this is it the start, we all want to hear/ see the first real dump that we know is going to stay,but truth is I never believe it until I see it and then step out on it, will not stop me looking/believing/hoping , what I do know is it will be White , how high up and how deep only god/noza knows , and he,s not that reliable either!

snow reports

Here's SLF on the forthcoming heavy snowfall at altitude, heavy rain in valleys.

Heavy snowfall in high alpine regions

- Between 120cm to 170cm in Simplon and Maggia.
- Snowline ranging between 2000m to 3000m.

Here's ESTOFEX on the rainfall (snow).

- "A level 2 was issued for S-France and NW-Italy mainly for excessive rainfall amounts."
- "For the western/central Mediterranean, this day marks the start of a particluar dangerous multi-day excessive rainfall event for parts of SE-France and parts of NW-Italy."
- "extreme NW-Italy may locally see rainfall amounts in excess of 300 mm/ 24h!"

You know it makes sense.

Otherwise you'll just go on seeing the one name:

tallman, yes.

Read the first post in the thread (and indeed several others over the subsequent pages).

More recently have a look at 28 and 31 October for some thoughts on the potential for a more -NAO pattern possibly taking shape from mid month. The GFS operational output over the last 24 hours has tended to support this. Clearly though still too far out to have any confidence.

Rain/snow looks like it will be building through today in SW Alps and more so through Saturday and Sunday.

A snowHead

Thanks, I should have read more! I have heard it banded around many times but never really understood the impacts in the Alps and it sounds as though it is not well defined. With strong (and well documented) tele-connections in other regions - it becomes tempting for the casual observer to infer that ENSO can explain all the quirks in the weather! As is usually the way, it is far more complicated...

A snowHead

Continuing heavy rain and snow at high altitude over the weekend as the same system that brought the snow to the eastern US drives into the southern Alps. Flash floods caused several fatalities downstream in Genoa. The focus looks like Sestriere, through Monterosa to Zermatt.

Interesting to note how the NAO forecast is moving. Clearly still a spread, but with some quite steep negative options from mid month. Some of these are continuing to pop up in the ensembles, but it's a weak signal at present.

Nearer term the possibility of further rain/snow (though not on anything like the scale of the current weather) returning to the southern Alps in a week's time continues to crop up on charts.

Well, the person's real but it's just a made up name, see?

On the GFS graphs. 45 /6 still showing above average temps right to the end of sequence ,and this has been the case for the last week, it looks like all the predictions as seen earlier in the thread of a cold November are way of the mark,but then again no one until the last minute saw this HIgh pressure out to the east,with regards to this I do find it funny that no one could predict something like that bearing in mind how long it has lasted,shame wasn't further west, anyway forget November roll on December

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It's certainly been a mild start to November.

- But given it's only 05 November, perhaps a little early to write the month off.

- Most of the models I've been looking at on this thread have been suggesting a higher probability of a cold or average temperatures pre season (ie October, November, December). With a ratio of 10:7 in cold's favour. That said I'd take all LRF's with a pinch of salt.

- Average in terms of anomalies is +/-0.5C. Out of curiosity how does this compare with the previous 30 days? Looking at Bourg St Maurice station you get +0.42C which shows an average anomaly (though I'd expect there to be upwards pressure on that in the coming days).

- High pressure in eastern Europe? Well there's been a strong signal for dry weather so high pressure is likely to be playing a part somewhere. Here's how BCC saw the likely high pressure anomalies for November to January in September. And in fairness there is quite a lot of high pressure over eastern Europe.

- What about the GFS ensembles? It's simply not true to suggest they haven't been throwing out colder options for the second half of the month.

03 Nov 06z operational
03 Nov 12z operational
03 Nov 18z operational

But that's all in far FI and anything beyond seven days I wouldn't take that seriously. If a trend is there in FI even on multiple runs, but can't come into the high res section of the output and build then it isn't happening. A good example of this is the colder weather for 05 November which was cropping up in a few runs around 26 October. It never got past the +192 mark. So although it might have looked like the beginning of a trend in FI, after watching it a bit more carefully it never developed.

- For a bit of fun you could look back to this time of the season in last year's thread. Over this weekend and the following week in 2010 there were reports of temperatures of 17C at 800m on the German Austrian border (Samerberg Sue). Likely heavy rainfall coming into the Alps, snow line of 2500m+ (Brian). Outlook suggesting freezing level at 3000m in the coming week and only dropping to 2000m at the end of November. Then. On 11 November. It all changed it suddenly started looking colder and kept getting colder. Now I would be genuinely surprised if we got temperatures as cold as that again, but I would certainly not be surprised to see a colder patter developing in the second half of the month even if there are no signs now.

And just to be clear there is no strong identifiable link I have seen between a warm, cold or average start to November and the subsequent season.

Anyway, snowHeads is much more fun if you do.

What is it with this subject, the technicalities of which are pretty impenetrable to the average punter, that makes the experts so interesting and readable? Thank you, nozawaonsen, really fantastic contribution to the forum! Very Happy

I would never have believed that this would remain my favourite thread after previous experts stopped posting, but it still is.

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Here are the Meteo France avalanche warnings for Haute Savoie and Savoie covering this weekends rain and snow at high levels. Most of the rain this weekend (snow at altitude) has been focussed up towards the Swiss Italian border.

Haute Savoie

Rather neatly summed up as "Pas grand chose à se mettre sous la dent d'ici lundi prochain." Or not much to get your teeth into.

- Small amounts of snow 2400m down to 2200m
- However, much more snow on the Italian side down to 1600/1800m by Monday.

Savoie

- Violent winds gusting between 70 and 100kmh
- Snow line yo-yoing between 1800m and 2400m
- By Monday and above 2500m parts of Haute Marienne close to Italy could receive 60cm to 120cm. 10cm to 40cm elsewhere.

For what it's worth Snowforecast.com suggests 13 cm fell in Tignes at or around 2500m since Thursday night and 23cm at the top of the mountain.

Worth keeping an eye on the NAO forecast . It pushes back into positive territory over the next week before dropping quite sharply from mid month (the number of ensemble members heading south has increased over the last 24 hours). It will be interesting to see if this pattern continues and whether it starts getting picked up in the GFS model output.

Mid month also sees the Arctic Oscillation pushing down too.

For comparison here is a chart from Reading University showing how the NAO and AO dropped early in the last two winters.

Then you can post your own questions or snow reports...

An update from SLF on the storm in the southern Alps.

Large amounts of fresh fallen snow in the high alpine regions of southern Valais

So far.

- Precipitation started Thursday, snow line 2000m rose to 2400m on Saturday.
- Snowfall from just below 2600m, upper Maggia valleys, about 1m, from Monte Rosa into the Simplon region and in the remaining parts of northern Ticino, 50 to 70 cm. Along the remaining Main Alpine Ridge from the Great St. Bernard into the Bernina region about 30 cm of new snow.
- Winds were strong to storm force.

To come.

- Heaviest precipitation in southern Valais, at its most intense during Saturday night.
- From the Monte Rosa over the Simplon region into the Binntal, as much as an additional meter of snowfall is anticipated.
- Southern Valais over Goms into northern Ticino, another 30 to 50 cm of snowfall is expected.
- Even greater amounts of snowfall are possible.
- Initial snow line approximately 2600 m. Over the course of the day descending towards 2000 m.

After all it is free

Much of today's model output suggests a very slight cooling during the first few days of the week, still mild for the time of year though, before with high pressure never far from eastern Europe, temperatures start rising towards next weekend by which time temperatures are as mild if not slightly milder than this weekend.

Beyond then and into the low res section and weak signals continue to suggest the possibility of a pattern change later in the second half of the month with the potential for cooler weather with heights building to the north and a more -NAO. But too far off to have confidence... for now.

Pedantica,

Bless, let's see if the " average punter" is right.

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Any news on the first cold spell and snow in the UK???

Help!!

The all new 11/12 Weather Outlook thread

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