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Scotland Regional Weather Discussion 07/01/14


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Some interesting views (and some degree of scepticism) on this here:

 

http://www.winterhighland.info/forum/read.php?2,160860

 

I have a copy of the Adam Watson book so will need to remind myself of the chapter evaluating the possibility of glaciers existing historically in Scotland.

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Some thoughts from Fergie on Thursday snow potential, WBFL = Wet Bulb Freezing levels

http://forum.netweather.tv/topic/79144-model-output-discussion-19th-january-2014-18z-onwards/page-29#entry2902329

 

Mesoscale models out to Thursday morning at present.

 

Euro4 shows a good set of 850hPa temps, contrasted with the 950hPa on the front, above mentions post front the temps dropping, a couple of more runs will reveal more, hopefully fergie will post up a sneak peak later of Meto output. 528 line straddles the country on this morning fax which is good and you can just see the colder air filtering in here.

Posted Image850 hPa Euro4.gifPosted Image950 hPa Euro4.gif

Posted Image14012306_2106.gifPosted ImagePrecip.gif

 

NAE at 006z, again one step away from showing some real interest.

Posted ImageNAE 06z Thurs.gif

 

Hi Res GFS looking good for Thurs also.

Posted Image45-779UK.gif

 

Ian F had an interesting post on the MT highlighting that Web Bulb Freezing Levels  (WBFLs) on the euro4 12Z are widely sub 400m, which is very conducive to snow at low levels. We don't have access to this particular metric but a good shorthand for calculating the Wet Bulb temperature (if you don't have an actual 'Wet Bulb' thermometer as snow1975 has and can't be bothered plotting everything on a skew-t diagram) is that it's slightly greater than the 'mean' of the DP and the Air temperature. Anyway, if the wet bulb temperature is below 2C at surface level things are pretty peachy for snow, although getting it to lie is a different issue and in practice usually requires a Tw of 1C or lower, a DP around or below 0C and the Temperature below 2C. However, even then we need everything above the near surface freezing level to also be below 0C, which is why both the 850hpa and 950hpa levels are so important.

What I really like about the Euro4 is that we actually have a continuous set of data for the entirety of the British Isles for most of the parameters, whereas before we were having to look at discrete values at certain points which often meant that a given run would have the boundary between snow and rain as being e.g. 'somewhere between Edinburgh and Crieff' rather than saying whether all of Fife or none of Fife would end up with snow. The sub 0C 950s are already starting to push in on that chart, although once again it also highlights how much easier things would be if either a) the whole setup was shoved a few hundred miles west or b) we all lived on top of a fjord in Norway.

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Regards the potential for a Sunday storm, the latest NMM run from Netweather Extra has 100mph-110mph mean winds over an area of the Western Highlands taking in the Glencoe and Nevis Range mountains later Sunday. Never seen that colour band come across land before on that model, and we are looking at the 850hpa height being 3000 to 3500ft as well. GFS 06z had what looks like 105knots mean 850hpa wind - not as easy to see on the newer charts from weatheronline with the barbs as it used to be. GFS12z seems to occlude out the warm sector quicker and keep the low further North. One to watch anyway.

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Around 25% of the ensembles on the GEFS want to serve up some form of meaningful Easterly by the end of January. A real mixed bag among the rest with the troughing on a NW-SE trajectory the main theme, really is a good watch due to the variations thrown up day to day ebb and flow of disruption on that Scandi Block, prior to that even happening the daily will we or won't we see separation of the inbound trough from it's Canadian parent.

 

Among that 25% or so cluster there are a few belters.

 

Lucky Number 13 Please atmosphere, we have been waiting patiently for a long, long time...!

post-7292-0-37497300-1390325854_thumb.pnpost-7292-0-57633400-1390325841_thumb.pnpost-7292-0-94671900-1390325851_thumb.pn

 

And a few of the others...

post-7292-0-05723200-1390325894_thumb.pnpost-7292-0-88153900-1390325906_thumb.pnpost-7292-0-38321000-1390325908_thumb.pnpost-7292-0-51151400-1390325898_thumb.pn

 

Great model watching continues !

 

 

 

 

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Speaking of wet-bulb temperatures, here is a photo showing my set-up in a Stevenson screen. The wet-bulb on the right is covered in tubular cotton lab wick which dips into a container of distilled water.

post-10675-0-70951700-1390326267_thumb.j

Edited by snow1975
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the whole setup was shoved a few hundred miles west or Posted Image we all lived on top of a fjord in Norway.

 

I'll be at the bottom of one Sunday night through to Monday afternoon.

 

Shall be taking the camera.

 

http://www.yr.no/place/Norway/Rogaland/Stavanger/Stavanger/long.html

 

Quite looking forward to it, even though it's just one night and with work.

 

Lovely country and best of all, drinking a standard (large) beer with a meal in a posh restaurant is perfectly acceptable, even encouraged. What's not to like.

Edited by scottish skier
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Speaking of wet-bulb temperatures, here is a photo showing my set-up in a Stevenson screen. The wet-bulb on the right is covered in lab cotton wick which dips into a container of distilled water.

What are the two horizontal thermometers for?

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Pretty poor ECM tonight.  I think I am going to lay my head on the block here and say what I have been thinking since the start of winter.  Unless and Until the severe cold lifts out of the USA then we' re sunk! I felt at the beginning  that the USA set up was the cause of our poor winter this year and I think that we are shortly going to become embroiled in yet another saturated saga! There, I've said it.....shoot me if you must......we will see.   Once again USA is on the cusp of another severe cold spell which, 

I fear, spells more of the saturated same for us.  A few differences this time round I know, but that bloody polar vortex just refuses to lie down and die, aided and abetted by that lack lustre Azores high side- kick!  I hope the pair of them roast in hell!Posted Image  Phew!...feel better now.Posted Image

Edited by Blitzen
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Evening folks it's been a while since I posted in here !!

It really is amazing looking back a couple of winters ago, that were incredibly cold. People started saying that this would be a common occurrence, and here we are now on the verge of the kind of winters we used to get in the 80s .

Just goes to show that in our wee corner of the globe you can never predict what we're gonna get be it winter or be it summer-keeps you on your toes !!!

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Some nice big flakes on bbc 2 winter watch now. Caught the crew by surprise I think from what they said at the beginning regarding their met forecast. Hopefully the next few days may take us all by surprise as very much up in the air until the low passes.

Edit: they are in the Cairngorm flood plains this week.

Edited by geordiekev
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Pretty poor ECM tonight.  I think I am going to lay my head on the block here and say what I have been thinking since the start of winter.  Unless and Until the severe cold lifts out of the USA then we' re sunk! I felt at the beginning  that the USA set up was the cause of our poor winter this year and I think that we are shortly going to become embroiled in yet another saturated saga! There, I've said it.....shoot me if you must......we will see.   Once again USA is on the cusp of another severe cold spell which, 

I fear, spells more of the saturated same for us.  A few differences this time round I know, but that bloody polar vortex just refuses to lie down and die, aided and abetted by that lack lustre Azores high side- kick!  I hope the pair of them roast in hell!Posted Image  Phew!...feel better now.Posted Image

 

Could be worse. You're presumably not a West Ham supporter!

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Out today putting hay feeders into fields for sheep as they finish off the last of the autumn grass. just in case winter arrives.

 

A question for Hairy Celt and other nature experts. We are now seeing badger activity digging etc..in every field on the farm .Never known such numbers of them with the tramlines in the growing crops of barley being used as motorways in the summer time by the badgers .Also noticing the lack of of lots of other ground based wildlife hares,birds etc... 

 

 Is this the result of large numbers of badgers foraging or are the large numbers of pine martin more responsible?

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not the best day with the models but I wouldn't give up on things for at least a few more days yet if you remember me saying yesterday or the day before we seem to be in a rinse and repeat pattern and I expected another shot to come straight on the heels if this one didn't work well I am going to show something on the ECM.

 

now if we remember yesterday it was showing the low on the US east coast and I felt this wasn't supposed to be there well today it has disappeared as you can see below in the 192hr and 216hr chart and you notice we lose the chance with our arctic high which phases with the Siberian high

 

post-18233-0-15287800-1390341193_thumb.gpost-18233-0-42676100-1390341208_thumb.g

 

now if we move on to the 240hr chart then we see another arctic high come in the rinse and repeat cycle and notice we have another low pressure on the US east coast so similar to the one before only later on

 

post-18233-0-97090000-1390341197_thumb.g

 

now if we look at the ECM mean 500 anomalies charts then you see they haven't changed much we still have the separation taking place at Greenland and the high sitting there waiting for an attempt to ridge

 

post-18233-0-18676100-1390341210_thumb.gpost-18233-0-83241400-1390341210_thumb.gpost-18233-0-17769200-1390341208_thumb.g

 

now this could be a few things either

 

it was too quick with the pattern in the atlantic and its slowing it down

 

there is still too much energy and we have to wait for more to leave

 

and the notable thing from this run with the low on the US east coast and the rinse and repeat arctic high if you look at the 850's chart at 240hr and maybe the first hints of the deep cold leaving the other side of the pond which if happened ahead of the low pressure moving up the east coast would give us a better chance of getting some ridging from the atlantic.

 

post-18233-0-48734600-1390341180_thumb.g

 

plus on a naughty side if it was close to verifying we could well see snow on a westerly and south of the border largely missing out Posted Image

 

so give it some more time yet and I strongly suspect if we don't win this time another chance will follow quickly again

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Probably get a few hours of snow Thursday.Then its pretty much back mush.Not even bothered now.As long as ski centres keep open.Been an epically bad winter.Our coldest day as November!

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a few things I managed to find today

 

maybe we should start basing our forecasts on SST's as JOE B called the winter right over there from SST comparison

 

post-18233-0-38059800-1390346064_thumb.j

 

heres a map of the weather extremes of 2013 across the world hopefully it will be big enough to read if not you will prob have to zoom your screen

 

post-18233-0-65944000-1390346055_thumb.p

 

found a colour image of that magically appearing stone on mars that I posted last night

 

post-18233-0-28095300-1390346090_thumb.j

 

and finally

 

post-18233-0-00173200-1390346065_thumb.j

 

ppppffffftttttttt 4x4 driver they think they can get away with anything Posted Image

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I think things look basically fine to be honest, at the moment neither the cold pool to the east or the milder Atlantic air are properly winning out so we'll probably be in for a fair few more borderline snowfalls in the next 10 days, with minor shifts all that's needed to bring the real cold in.

This is far from the worst ensemble mean I've seen given a mix of some milder solutions in there - most of the time uppers are sitting close to the -5C line and with the influence of the trough that means more snow. Certainly the ski runs will benefit majorly from this, with everything above Munro level seeing almost entirely snow almost all of the time, but it remains to be seen just how well lower levels can do out of this:

Posted Image

Surface temperatures are very much on a descending trend and by the start of February the mean is down around 0C.

The front on Thursday does seem to break up a bit quickly but still some snow potential, particularly for around 9am now (it just keeps getting earlier):
Posted Image

Posted Image

Posted Image

I'm just as optimistic as I was last night, broadly speaking - not all that much's changed really and we're still in with a better chance of snow now than we've had so far this winter. Granted that's not saying much, but it certainly is better than nothing, and still with a bit margin of error i.e. slight 'downgrades' would mean colder NWerly type flows which are still good for us but not so much down south, and upgrades obviously help us out too as it brings in the actual non-marginal snow. The cold pool to the east is there, and I've no doubt that we will tap into it at some point before winter's done - the question really is when.

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I'll be at the bottom of one Sunday night through to Monday afternoon.

 

Shall be taking the camera.

 

http://www.yr.no/place/Norway/Rogaland/Stavanger/Stavanger/long.html

 

Quite looking forward to it, even though it's just one night and with work.

 

Lovely country and best of all, drinking a standard (large) beer with a meal in a posh restaurant is perfectly acceptable, even encouraged. What's not to like.

 

 

 

Think the same of Norway. We went there on  our honeymoon just so I could get to see some July snow.  Just know there will be a few comments!!!!!!

 

Currently 3.9c and cloudy here.

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Always wanted to see Norway, my dad was there during the war and loved the people. Not gonny make it now though, too old and poor :)

I've cracked the weather charts you all keep posting - It's like a wallpaper sample book, innit? You pick the ones you like then slap them on the wall. Gottit.

I'm having the nice dark blue and purple ones, I like purple Posted Image

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And the theme of the winter continues as it's grey, 5C and wet here (9.5mm from midnight until I checked at around 8:30am) yet again!

 

Trying really, really hard not to get too despondent despite the excellent posts from LS & BUS. You can only look at so many charts with "potential" not come to anything much before you start to lose your faith. Even Frosty on the MO thread went through his manic depressive phase the other night, and which he doesn't seem to have fully recovered from.

 

Youngest son asked again this morning if it was snowing and when I said it was raining he replied "It's never going to snow this winter". I think we're going to have to pay a visit to Glenshee or the like just so he can throw a snowball at me. At least Glenshee is looking much whiter this morning on the webcam http://m.webcam-hd.com/ski-scotland/glenshee and it should hopefully stay cool enough for anything else that falls to road level there over the next few days to stay falling as snow.

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