 Poster: A snowHead
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Watching GWV Christmas Weather forecasts, and in the space of 4 days the output has changed from one of the coldest signals ever, to the warmest signal ever.
He's still using CFSv2 until GFS comes into range, but it just shows you how totally unreliable this range / model is. Yeah it's fun to look at (when it's "right"), but am beginning to think it's utterly pointless.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| langball wrote: |
Watching GWV Christmas Weather forecasts, and in the space of 4 days the output has changed from one of the coldest signals ever, to the warmest signal ever.
He's still using CFSv2 until GFS comes into range, but it just shows you how totally unreliable this range / model is. Yeah it's fun to look at, but am beginning to think it's utterly pointless. |
There's much more reliable indicators of long term models, than CFS.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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@smagsmith, no need to worry about 'natural' snow -- the cannons are blowing full time at the mo' (sella ronda has been opened)
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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There are no reliable long term weather forecasts...
12z ECM has mild weather across Europe for pretty much the whole of its run. GFS toys with a return to more seasonal weather in FI, but at present is tending towards further milder weather. So nothing to get too excited about in the forecasts at present. It will stay sunny for now and so should be pleasant if you get up high. Ischgl was good today though pistes are hard packed.
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| albob wrote: |
| @smagsmith, no need to worry about 'natural' snow -- the cannons are blowing full time at the mo' (sella ronda has been opened) |
Thanks albob
Never been to Dolomites. Can't get wait to give it a go.
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Long term models give you an idea what will happen in the future, definitely not accurate or to be relied on...
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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The current accuracy for EC 10 days out is 52.6%, so it's not to be relied on but gives an idea of what may happen...
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I am into my usual "6 weeks to go" period where I look at this thread every day, it will move to twice a day and then onto every 5 minutes in the last week. The usual anticipation mixed with dread will start to happen the longer we go without some sign of snow on the horizon. 6 weeks is a long time, about a quarter of the season and although there have been a few close shaves in the past I have always been lucky with a decent dump before I go. I can only remember one disaster and that was in La Mongie about 10 years ago when we went walking in shorts and T shirts instead of skiing but the only one that came close since then was Chatel about 6-7 years ago. It was again 20+ degrees and completely green in Chatel and we were really downhearted but when we went to Linga and Avoriaz everything was open so we still had a really decent few days skiing.
Nowadays the snow making can make sure you always get something decent.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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| Jellybeans1000 wrote: |
| The current accuracy for EC 10 days out is 52.6%, so it's not to be relied on but gives an idea of what may happen... |
So a similar probability to a coin toss then...?
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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3 weeks to go 
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00z GFS op has thrown in the towel and gone mild for the whole run. ECM 00z more interested in something cold round 13 December, but brief on this morning's output.
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You know it makes sense.
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In aviation there's something called a TAF which is a short term forecast for a specific airport. They're always surprisingly accurate probaby by virtue of the fact that they are only looking up to 24hr ahead. There's a coded segment that appears that reads "prob40" (40% probability) followed by a weather occurrence such as +the (heavy thunderstorms). It's a masterstroke by the forecasters because if it happens they can say "we told you there was a good chance", and if it doesn't they say "we told you it probably wouldn't "!
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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@Jellybeans1000, it is to be relied on, but only when it's what I want to read......
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Poster: A snowHead
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@esaw1, a TAF from a Taff ? Sorry couldn't resist 
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| mikeycharlton wrote: |
| Jellybeans1000 wrote: |
| The current accuracy for EC 10 days out is 52.6%, so it's not to be relied on but gives an idea of what may happen... |
So a similar probability to a coin toss then...? |
I like long term forecasting... it's my former part time job.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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| 2planks wrote: |
| @esaw1, a TAF from a Taff ? Sorry couldn't resist |
Ah, but I live the right side of the bridge. Though actually I was dragged up in London.
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You need to Login to know who's really who.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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@AthersT, yes though the op run as opposed to the control is still trending mild.
@sugardaddy, there is a fairly simple choice given weather is unpredictable and complex and people want forecasts that go well beyond what is feasible to predict with confidence (eg 3-5 days). You can either lie and say this outcome is definite (it will definitely be sunny or snowy in 10 days), or you can be more honest and say it's not that clear cut, but the probability is X, Y, Z. So I guess it depends on whether you want false certainty or honest uncertainty.
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what's the difference between the operational run and the control run ?
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@esaw1, Yip and the forecasters are generally based at the airport (especially military ones) so local knowledge comes into play. I do use them in my Tignes forecast, especially at weekends to forecast the probability of 2planks delivering his self loading freight to the right airport at the right time!!
@2planks, You've beena bit quiet lately - busy summer season!
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@notnats, the way I understand it is that the control run is run with the same computing cycles and data input resolution as the operational but it is given just a little perturbation at the outset such as that from the beating of a butterfly's wings in Mexico (probably an under-exaggeration, but you get the point). It's run as a model sense check. The other ensemble members are run at lower resolution with similar perturbations at the outset (although they are all as high in computing resolution now as the operational/control were just a year or so ago). The fact that there's still such an enormous amount of deviation is testament to how incredibly chaotic the atmosphere and its influences are in the model, and a reflection of the real physics.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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@moffatross, I think that's close but not quite right.
The operational run is the high resolution version, with no tweaking or interfering.
The control run and the ensemble runs are all run at a slightly lower resolution (fewer data points), but whereas the ensembles all get minor 'perturbations' at the outset, the control is untouched (hence it's called the control).
So the control acts as a control for all the ensembles in a classic sense, but due to its relationship to the operational (neither is tweaked) it also serves to indicate at which point during the forecast period the resolution is starting to have a significant effect.
So on the above charts (and don't forget, each only represents one pinpoint location on the charts), the control tends to decouple around the 12th, suggesting the resolution might have become a significant issue by then.
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@notnats, my info is a few years old so I could be wrong but I think the Control and Op runs are run on identical inputs. The Run GFS/Op (Hauptlauf on some graphs) out is run at highest resolution (1/2 degree grid) whereas the control run is older software which only calculates for a full degree grid. The other runs have the "butterfly effect" added to give a range of forecast variations.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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Oops, slightly slow typing.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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I guess there's a chance of snowmaking, but that all looks like a rerun of last season!!!
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and the one before that......when there was scant little until snowmedeggeon on Boxing Day
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You know it makes sense.
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@Daleskier,
As far as I can see (ski?)
Open that wasn't at all or very much open at this time last year:
- Grands Montets (and possibly Brevent-Flegere as of next Saturday)
- Monterosa
- Espace Killy (no personal experience so I am quite happy to be shown wrong here)
- Verbier
- Courmayeur
So in my own local and personal experience, it's really quite different from last year.
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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A bit of mixed snow and rain at my place this morning. Snowing to the North and South of Seattle. Cold temps have arrived for big chunks of North America. Big old cold front dropping down from the Gulf of Alaska. There's a storm to the South and West churning in the Pacific that looks to be following on the coattails of the cold front to bring some snow to the Cascades and possibly to the Sierra's around Wed. night into Thursday. (Storm track seems to be more North of Cali. This front will be warmer than the one that just hit, so snow levels will rise.)
Colorado should be seeing the remnants of the storm that hit the PNW on Saturday night with 10cm-20cm of snow through Tuesday, and then the storm coming through on Wed. on the West Coast will work it's way into Utah and Colorado around late Thursday/Friday morning into this weekend. Wyoming and the Tetons should also benefit from the storm percolating out in the Pacific. The usual caveats apply, and the storm will make it's decision when it gets closer to land.
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Poster: A snowHead
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@chocksaway, sort of !
So this new moon stuff is nonsense but it always seems to work !
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Actually, @2planks, I think it's been examined a few times (easy enough, we know when there's a new moon and we know what the weather was) and there's absolutely nothing in it.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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Andorra and Spain have had a good start to the season this year.
All the major Andorra resorts are now open.
And Sierra Nevada, in Spain, already has 60-80% of all its lifts and trails open.
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You need to Login to know who's really who.
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@under a new name, back to the seaweed then....
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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| under a new name wrote: |
Open that wasn't at all or very much open at this time last year:
...
So in my own local and personal experience, it's really quite different from last year. |
Pila is also open, which wasn't last year.
The Espace Killy is in very good condition IMHO.
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12z gives a hint of a break-up from the 19th?
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Going back to the new moon thing there is really good evidence that all major weather events tend to occur within 14 days of a new moon.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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Better get some new moon charts up then
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It looks like possible light snow falls on the 12th and 16th. (16th favouring Austria)
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FAQ
