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Ensembles??  ie statistics?

 

each model has its main run then it has several different runs between 20 up to I think maybe 50 on some models which run with slightly different inputs than the main model then when you see ensembles charts like below you see all the runs and also the mean line which in this case is the yellow line and they take the mean from all different parameters temps, pressure, rainfall etc to give an idea of what we may see instead of just taking what one model run says

 

post-18233-0-88066800-1388426651_thumb.g

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Learner area is packed with information - http://forum.netweather.tv/forum/5-the-netweather-guides/

 

From there this link on Ensemble forecasting -

 

https://docs.google.com/document/d/1ClkAme7CLzViv51_1r8KQINHoendcxYbHJh2Ya2zQzI/edit?hl=en&pli=1

 

RE: Meteociel - couple of images may help.

 

When you select GEFS - Global Ensemble Forecasting System, the 'control' run opens, from here and highlighted you can see the mean and also spread charts.

post-7292-0-54311000-1388427378_thumb.pn

 

If you click panel, this opens up all the different variances created by each of the 'perturbations' or ensemble members.

post-7292-0-36308000-1388427395_thumb.pn

 

If you click diagramme you can see the ensembles plotted as a graph, click Carte Europe presents a map on whcih you can click to bring up the ensembles for that location. http://www.meteociel.fr/modeles/gefs.php?carte=1

post-7292-0-42141500-1388427646_thumb.gi

 

Where the operational run deviates from the cluster of ensembles this can be considered an 'outlier' solution, you read this a lot specifically where a model produces a very warm run or a very cold run.

 

 

 

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not far off its the polar vortex on Saturn I spotted it on twitter and thought it looked quite cool makes a change to see a vortex when it isn't just colours and lines.

 

Find a wider range image BUS - it's hexagonal...!!

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Thats cool alright,     Today i was costing up the weather balloon with gps and camera etc to try get some real nice pic's up in the stratosphere...gets to 90-125,000ft...problem is where it lands as its quite common up here to lose signal very easy so finding the payload could be difficult, working on it though..

 

Lorenzo i appreciate the post and will be putting my head in the learners section,  Enjoy the crack here!   It would be easy to carry on posting stats of the week or of the day but i want my teeth into forecasting..the GFS was what i used before i came on here, i only really understood pressure and isobars really on it...nice to know i was looking at a model you guys use though... 

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Like everywhere else its been rain, rain and more rain here today. At least my rain gauge is getting some action,its recorded 14.2mm of rain so far today, so not as much as some. Temp is currently 5.8C but car was showing 4C when I was out earlier. Nothing even remotely slush like though, probably cos the dew point ain't much lower than the temperature. Virtually no wind all day.

 

Hopefully the ski centres are getting plastered with snow, which would at least be some consolation while we wait for more widespread cold and snow.

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ECM 12z went wrong quite early tonight so will wait for ensembles to see where it stands but think it might be wrong as early as 120hr.

 

below is yesterdays 12z at 144hr and this mornings 144hr and todays 12z 120hr if you notice both yesterdays and this mornings both have ridging through Alaska and they look a good match for the pattern moved 12hrs on then todays 12z and there is no ridging which greatly affects things

 

post-18233-0-07178300-1388435452_thumb.gpost-18233-0-43826200-1388435513_thumb.gpost-18233-0-06378300-1388435573_thumb.g

 

if we move on to yesterdays 12z 168hr and this mornings 0z 168hr and todays 12z 144hr then you can see again yesterdays 12z and todays 0z look ok for a 12hr progression then todays 12z doesn't look quite right then the run goes a little wrong from here on in

 

post-18233-0-71679400-1388435453_thumb.gpost-18233-0-68506300-1388435515_thumb.gpost-18233-0-01724400-1388435574_thumb.g

 

maybe a hiccup maybe not or maybe some Shannon entropy kicking in that we will just have to wait and see

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Back roads around here were pretty bad. Was torrential in the early afternoon.

 

Had to turn around at one point on the way to Gala; could probably have gone through but silly risking a flooded engine bay.

 

Few idiots were attempting it; hope they knew where their air intake was.

 

TIP: Don't drive through unless you know for sure the base of the car will have at least an inch of clearance. Cars float - at least initially so... Drive slowly - going fast doesn't help unless it's a narrow stretch of water and you're in a real hurry. Go fast and the force of water can tear off the sump guard, wheel arch internal covers etc; they were never meant to take that. Also make sure your engine air intake is well clear; on some cars it can be quite low.

 

Leon has ridden narrow 2 ft drifts on winters. 1.5 ft of flood is another matter...

Edited by scottish skier
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Back roads around here were pretty bad. Was torrential in the early afternoon.

 

 

 

TIP: Don't drive through unless you know for sure the base of the car will have at least an inch of clearance. Cars float - at least initially so... Drive slowly - going fast doesn't help unless it's a narrow stretch of water and you're in a real hurry. Go fast and the force of water can tear off the sump guard, wheel arch internal covers etc; they were never meant to take that. Also make sure your engine air intake is well clear; on some cars it can be quite low.

 

Leon has ridden narrow 2 ft drifts on winters. 1.5 ft of flood is another matter...

Especially if you drive an Alfa Romeo, Rover/MG or Vectra Diesel- these are the most common cars I pull out of floods. Not that we get much flooding in Fife.. I'm off today and tomorrow so not my problem!

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was in the MOD and saw this posted so thought I would post it in here as this is what I have been talking about and was looking for to be the eventual outcome in the pattern I have been looking at with the first ridge putting some heights to our north then later on a push of heights from the Atlantic to reinforce the block

 

post-18233-0-59817600-1388441457_thumb.p

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was in the MOD and saw this posted so thought I would post it in here as this is what I have been talking about and was looking for to be the eventual outcome in the pattern I have been looking at with the first ridge putting some heights to our north then later on a push of heights from the Atlantic to reinforce the block

 

Posted Imagepost-6981-0-91844300-1388437758.png

As long as the high gets no closer to us than that? 

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Did we have 24/7 Breaking News today about all the flooding? I seem to recall we had that recently at a flooding event further south a few days ago.....Posted Image

 

Scottish flooding was about 10 mins in on the Radio 4 six o'clock news and got 2 very short sentences.  Perhaps they couldn't find anyone with a sufficiently flooded ego to be worth interviewing.

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yeah would be good a little further north if something like that does manage to come off.

 

I think that's almost perfect to be honest, slightly depends on the upper cold pool I guess but our mean heights in winter are so low that even a little bit above average is still pretty low in an easterly type setup.

This is December 1st 2010 in the same format for example:

post-9298-0-22445000-1388446472_thumb.gi

And the actual:

Posted Image

It's not quite as good as the above on second glance at the air pressure charts but it'd still be quite a decent wee easterly even at that. Even slightly lower heights with a similarly weak central pressured high (i.e. everything shifted a bit north) would give potential for shortwave activity developing with slack pressure and a good convective setup if the flow is stronger.

Anyway, all speculative yet, would be good just to get to a stage where we can discuss charts like that as a realistic possibility again.

 

Also, as Chiono pointed out on the MT we don't have the geopotential 10hpa charts (I'm sure they're out there somewhere though, if you're on Lorenzo link me up to them as it would be enlightening for the 18Z) but this looks pretty close to a full on split SSW for the 15th:

Posted Image

edit: no need, appears to be pretty comprehensively covered on the strat thread as ever (also stupidly forgot that SSW is defined by reverse of winds at 30hpa rather than 10hpaPosted Image )

Edited by LomondSnowstorm
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the ECM 12z was on the warmer side of the ensembles and was one of the latest with the ridge all probably due to downstream the lack or ridging in Alaska if it had ridged earlier it probably would have placed the heights in a more favourable position to trap more of the trough underneath it as it looks ready to sink on the op.

 

post-18233-0-36394300-1388447808_thumb.gpost-18233-0-45309700-1388447806_thumb.g

 

 

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