brian
brian
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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brian wrote: |
Incidentally, weather fans, the ECMWF (European Centre for Medium-range Weather Forecasting) has extended its free output to +240 hours now. |
Where can we access these data?
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brian
brian
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You need to Login to know who's really who.
You need to Login to know who's really who.
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Was shown this site recently. It's an excellent GFS viewer:
http://www2.wetter3.de/animation.html
Select "Schneefallgrenze, Schneedecke" and step "back" a couple of clicks to Wednesday 18th.
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brian
brian
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skanky, thanks !
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You'll need to Register first of course.
You'll need to Register first of course.
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Apologies for stupidity, but what am I seeing? Is that a touch of snow over Scotland?
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rob@rar, I'm glad someone else asked before I did
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brian
brian
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rob@rar wrote: |
Apologies for stupidity, but what am I seeing? Is that a touch of snow over Scotland? |
Yeah, the white bits are snow and the blue number is equivalent rainfall depth in mm (e.g. if the freezing level was higher, you'd get 2mm of rainfall). The amounts are the total for the six hours preceding the time shown on the chart (if it's the same as other GFS charts). So I make it about 10mm equivalent over about 24 hours.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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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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wow, never seen those Oct piccies before, looks mega depth, how many days did it snow to get that depth in October?
...and did it all melt in November??
Cheers,
greg
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You know it makes sense.
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skanky, thats the best looking graph I've ever seen. Don' really get it but it looks wicked. I might print it out and stick it on my wall.
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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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rumpole, which one?
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Poster: A snowHead
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Well that didn't last long!
I guess we need to see if any other runs bring it back.
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brian
brian
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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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brian, UCA.
However, still some hope from ECMWF, and the charts are similar enough along with UKMO. I wouldn't write it off just yet.
See what happens between now and Friday.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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You weather forecasters are all the same: raise our hopes, but then cruelly take away any chances of snow!
Do you think it would be worth asking the Mods to make the Genf, Aberdeen and one or two US based locations stickies so that they appear at the top of page 1 in this section?
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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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Can't see why not. I'd have a different thread for each one.
It's fairly easy to bookmark one, and there is now the ability to pick anywhere you want in Europe graphically, while it's been possible for a long time to build a forecast for any position as long as you know its lat/long (I think DGOrf does this for Wengen, for example). However, most of this will just be GFS, which is just one model (and I believe not the best one - apparently that's ECMWF).
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You'll need to Register first of course.
You'll need to Register first of course.
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skanky wrote: |
there is now the ability to pick anywhere you want in Europe graphically, while it's been possible for a long time to build a forecast for any position as long as you know its lat/long (I think DGOrf does this for Wengen, for example). |
I do this for Tignes (must find out lat and long for Les Arcs) but you have to go through two or three webpages before the graph is gnerated. I'm not sure how to get an updatable image which could be posted into a thread here other than the Genf one. Any clues how to do this?
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rob@rar, the Genf one is either an actual product by GFS or built by Wetterzentrale. I *think* the former, but I have seen the same ensemble graph look very different between two sites supposedly showing the same thing (only every now and then, though). I'm not sure how to do it for elsewhere, but if I get a chance tomorrow, I'll have a look around the sites I know.
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skanky, thanks. I use the NOAA site to build the GFS graph for Tignes (and anywhere else I have lat and long for).
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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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rob@rar, yeah, but I think they require a code input to prevent auto-generation. Because the GFS stuff is free, there's loads of sites out there that carry it. I'm sure someone's done something with it - though some do charge.
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brian
brian
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rob@rar, I've played about with trying to auto-generate the NOAA page for Grimentz but I'm defeated by the manual text entry bit.
The standard Wetterzentrale menu has Muenchen as well which could be useful ?
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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skanky, yes, you do have to enter a code each time. That's why I've not been able to post the output. If you come across any other sites which do the same thing without such protection that would be good (although it might put snowforecast.com out of business!).
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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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rob@rar, if they're any good they won't just be trying to resell GFS raw output. Which should mean their forecasts will be better than anything we post up here, so it will still be worth people subscribing to them. I treat this more as an entertaining exercise and will still keep an eye on the professionals' output (like I do with UK forecasts). I hope people realise that.
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skanky, yes, I'm sure you're right, although I'm guessing its some sort of automated process. I can't imagine them being able to take individual decisions for single resorts because they offer forecasts for so many.
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You know it makes sense.
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rob@rar, they probably do a Tarenteise forecast, a Valais (N & S?) forecast, etc.?
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brian
brian
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skanky, snow-forecast ?
This is what it says on their site ....
the snow-guessers wrote: |
We use the Global Forecast System (GFS) weather models for our input data. For our purposes these are ideal, not only because they are detailed, reliable and frequently updated, but also, because they are intended for aviation planning. Thus, they contain accurate descriptions of how conditions vary with elevation. This provides the key to how we derive surface temperature over a wide range of altitudes using digital elevation models. When we combine this with preciptiation forecasts, we arrive at snowfall.
Our Snow Forecast Maps are calculated by estimating the temperature on the surface (represented by a 1km digital elevation model) using lapse rates derived from pressure and temperature data. Snowfall is predicted wherever this same model forecasts precipitation falling onto ground that is expected to be below freezing on the basis of its altitude and the lapse rate at that point. The quantity of snow is given by the forecast accumulated precipitation, multiplied by a conservative snow:rain factor (8.0). In some areas, where dry and powdery snow tends to fall, such as central Otago in New Zealand, this factor can sometimes be as great as 12 or more which would lead to an underestimate in snow levels locally and better ski conditions.
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Poster: A snowHead
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skanky, that might be a sensible compromise. I'll pay a bit more attention to them this year after ignoring their forecasts for the past couple of seasons because they seemed to significantly overestimate likely snow depths.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Quote: |
We use the Global Forecast System (GFS) weather models for our input data. For our purposes these are ideal, |
Because they are free.
Snowdepth is difficult to estimate and most straight conversion factors are no more than rules of thumb. If they're basing theirs on NZ (google "snow:rain factor") then they probably will be out by a margin in various situations - though here we're already stretching the limits of my knowledge, so I'll admit that they probably know far, far more about this than I do.
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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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http://meteonet.nl/aktueel/brackall.htm
FAX now showing an nly could be on the cards.
Also, those GFS ensembles now all showing a cold spell - still no full agreement from all the models though. Keep watching for HP over Greenland/Iceland.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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Sorry not got round to it yet, but those with firefox may want to check out the forecastfox extension (for 48 hour fourecasts).
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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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skanky wrote: |
brian, UCA.
However, still some hope from ECMWF, and the charts are similar enough along with UKMO. I wouldn't write it off just yet.
See what happens between now and Friday. |
Well the potential for snow flurries in Scotland is still there, but little agreement between the models. UKMO & GFS have a broad agreement, ECMWF is off the way though. The difference between cold and warmth for N England and Scotland is down to quite small differences in the systems' positioning and their size - especially with that trough extending NE from the off the SW.
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brian
brian
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BBC weather mentioned a chance of snow on the highlands later today....
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kitenski,
Beleive it when I see it. Look what happened last week - stayed warm and wet. Was hoping for a light dusting on Cairngorm this morning as it got down to 0C, but not a sign at the moment. Beginning of November looks warm again with summit temps approaching double figures.
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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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Looking quite good for Tues/Weds next week. The main model difference seems to be in the timing (ECMWF delaying it slightly).
Might not last long but with HP possibly building behind it, their could be some cool nights and sunny days to enjoy any snow that does fall. Definitely worth watching.
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Are you a believer now Dave
Dave Horsley wrote: |
kitenski,
Beleive it when I see it. Look what happened last week - stayed warm and wet. Was hoping for a light dusting on Cairngorm this morning as it got down to 0C, but not a sign at the moment. Beginning of November looks warm again with summit temps approaching double figures. |
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