General Model Output Discussion

[snowingman]

apart from Scotland

no really deep penetrating cold on the way

interesting to see another pesky low heading in from the SW later in Week... could this bring the snow we all want?

[Solar Cycles]

Well looks like yesterdays GFS was on the ball, regarding today's output.

[TEITS]

apart from Scotland

no really deep penetrating cold on the way

interesting to see another pesky low heading in from the SW later in Week... could this bring the snow we all want?

These would disagree.

http://charts.netweather.tv/ensimages/ens.20091229/00/t850Cambridgeshire.png

Little to add this morning from last night really. The medium range will continue to be uncertain until the exact positioning of the block is sorted out. Howver the trend of the E,ly being followed by a N,ly seems set. However due to the positioning of the block will it be a NW/N/NE,ly?

[Methuselah]

These would disagree.

http://charts.netweather.tv/ensimages/ens.20091229/00/t850Cambridgeshire.png

Little to add this morning from last night really. The medium range will continue to be uncertain until the exact positioning of the block is sorted out. Howver the trend of the E,ly being followed by a N,ly seems set. However due to the positioning of the block will it be a NW/N/NE,ly?

I think you're pretty-well spot-on there, Dave. And, in any case, you don't need -16C for it to snow! :lol:

[Neilsouth]

Just watched sky news weather long range

North East winds into south east and east , but it looked dry on thursday and into friday. By late friday a northerly and dry and also dry on saturday but temps of -1 - 1c across the uk

My question is , what models do sky news use?

[nick sussex]

Well looks like yesterdays GFS was on the ball, regarding today's output.

No i don't think so, it originally progged the milder air getting into the north and then slowly backtracked to other guidance by edging this much further south!

The gfs caved in to the ecm in terms of it's shorter term and medium term, there was a lot of debate about this yesterday in here with the ecm and gem having proved the most reliable, the gfs and ukmo were all over the place, the ukmo came on board first and then finally the gfs.

[TEITS]

I think you're pretty-well spot-on there, Dave. And, in any case, you don't need -16C for it to snow!

Morning Pete hope you had a new Xmas mate.

One feature that much of Scotland needs to keep an eye on is the SW coming from Norway. A possibility that much of N/E Scotland could see prolonged snowfall between Sat/Sun.

http://www.wetterzentrale.de/pics/Recm961.gif

I will also add that for members in the E including E Anglia/SE the best day for convective snowfall via the E,ly is on Friday. This risk fades on Saturday as we lose the E,ly and is replaced by a slack N,ly.

[Methuselah]

Morning Pete hope you had a new Xmas mate.

One feature that much of Scotland needs to keep an eye on is the SW coming from Norway. A possibility that much of N/E Scotland could see prolonged snowfall between Sat/Sun.

http://www.wetterzentrale.de/pics/Recm961.gif

I will also add that for members in the E including E Anglia/SE the best day for convective snowfall via the E,ly is on Friday. This risk fades on Saturday as we lose the E,ly and is replaced by a slack N,ly.

Very nice thanks, mate. You?

Aye, I've been watching that shortwave quite closely. With such cold uppers involved, we could be in for a right dumping? Another thing: once the cold air has taken a grip 'darn sarf,' any attack from the SW will have a far-better chance of producing something memorable, down there, than the current set-up...

[Weather-history]

ECM De Bilt ensembles, still cold around New Year period but it is notable how they are from the 2nd weekend of the New Year, milder

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

[snowray]

Just watched sky news weather long range

North East winds into south east and east , but it looked dry on thursday and into friday. By late friday a northerly and dry and also dry on saturday but temps of -1 - 1c across the uk

My question is , what models do sky news use?

From what I can see Neil, this is not going to be all that good for us in Kent to start off with at any rate, currently only snowing on higher ground so very marginal stuff, mainly in Wales, then the colder air realy strugles to move South East of London. By friday the main band has fizzled out and we are relying on showers, which could get heavy and of snow but probably rather hit and miss, the streamer that we can see on the 06z is going to be our only hope. Could end up with one band over East Anglia and the other over Northern France.

Very good though for a triangle around North Wales, Gloucester, Birmingham I'd say. None the less most places will see something by friday.

Edited December 29, 2009 by snowray

[cooling climate]

These would disagree.

http://www.meteociel...M0-144.GIF?28-0

For some reason the 850s have not updated and are showing the 12z still.

[Pennine Ten Foot Drifts]

Couple of observations. Firstly, the much maligned GFS's handling of this low. I'd say if it got it a little too far north, then no more so than ECM got it too far south, so I'd say honours even, especially as the precipitation is already reaching Cheshire and Derbyshire, which if anything is closest to the GFS precipitation predictions for 10:00 am today.

And regarding the next few days, it looks predominantly cold and dull. The flow is too slack for anything significant in terms of snow from the E or NE for anywhere other than Scotland and maybe a few lucky spots on the east coast, (though I doubt these will amount to anything dramatic).

So, we have a coldish rainy sleety snowy mix for parts of Southern Britain for the next 18 hours or so (not much fun and not much to get excited about), followed by cold, dull and generally dry for a good 4-5 days (not much to get excited about unless a possibility of a depressed January CET floats your boat !). And after that, who knows, some might get lucky with approaching lows, but then again they may not..........

[Solar Cycles]

No i don't think so, it originally progged the milder air getting into the north and then slowly backtracked to other guidance by edging this much further south!

The gfs caved in to the ecm in terms of it's shorter term and medium term, there was a lot of debate about this yesterday in here with the ecm and gem having proved the most reliable, the gfs and ukmo were all over the place, the ukmo came on board first and then finally the gfs.

I know there was Nick, and I agree with you the ECM is the most reliable, but I would say the GFS is nearer the mark today. Already the temp here is 3.9c, and overcast, with rain forecast late today!

[Snowaddict]

GFS Operational is quite persistent about that small but definite area of low pressure approaching from the southwest towards Day 5 / Day 6...

ECMWF has this further south but with 850mb temperatures of -8 to -11 in place, with an easterly feed, this could well give some snowfall to southwestern areas as well as Ireland..

GFS has been quite persistent on this so something to be watched..

SA

Edited December 29, 2009 by Snowaddict

[TEITS]

Such a shame a downgrade from last night , i was expecting atleast a few days of these strong winds even into the south east but not now!

Have to be honest I don't know why you see this as a downgrade because I said last night that for E Anglia/Kent the window of opportunity is very small i.e 24-36hrs. This remains the case with Friday offering the best prospects for convective snow in this region.

Beyond this and to be honest the positive is it remains cold and as we all know surprise snowfall often occurs.

Looking at the charts for +144 and to be honest I cannot believe some are disappointed. I would much rather have a block of HP over Greenland than a deep PV.

[GoonerGregg]

Just watched sky news weather long range

North East winds into south east and east , but it looked dry on thursday and into friday. By late friday a northerly and dry and also dry on saturday but temps of -1 - 1c across the uk

My question is , what models do sky news use?

It's called ' We don't know what Thurs & Fri will bring ' So we'll sit on the fence and wait and see.

[Mark Parsons]

GFS Operational is quite persistent about that small but definite area of low pressure approaching from the southwest towards Day 5 / Day 6...

ECMWF has this further south but with 850mb temperatures of -8 to -11 in place, with an easterly feed, this could well give some snowfall to southwestern areas as well as Ireland..

GFS has been quite persistent on this so something to be watched..

SA

Quite right to, this set up would produce an interesting time but being a week away I have my doubts that it will happen regardless of trend, heres hoping!!!

[Snowaddict]

I agree with TETIS regarding how on earth people are disappointed??

I haven't seen one decent snowfall yet this winter apart from some transient snow earlier last week & yet I am thrilled with the last cold spell and projected upcoming synoptics.

Some people continuously thrash out:

''Downgrade, downgrade - I won't get snow'' or ''I can believe this run'' etc etc..

Stop, sit back and look at the synoptics.

Lets take GFS 06Z @ T+150 shall we:

850mb temperatures of -8 to -11 across the UK & Ireland, several chances for snow showers beforehand into both Eastern Ireland, Eastern UK & Scotland. In addition, a feature to be watched towards T+120/T+132 that could potentially bring snowfall to southwestern parts.

Some will never be happy. How long have we waited for these synoptics?

Get some perspective on things, the outlook is fantastic, with relatively deep cold on offer.

SA

[cooling climate]

Looking at the charts for Friday new years day and the GFS has significantly increased the convective

precipitation (snow showers) for the eastern half of the UK.

This will likely continue on future runs.

The 06z is a very cold run so far and am liking it a lot.

[TEITS]

Yes the PPN is where the GFS forecast it to be right now no question. People were saying on here yesterday that areas North of Birmingham could remain dry - it's already raining here and has been for nearly an hour !

Your not seriously suggesting that yesterdays GFS 0Z was right are you?

Dry as a bone here and to be honest in the past hr the front has made very little progress towards me. I still don't believe the precip will make it as far N as the N Pennines which is what the BBC are suggesting. I reckon the fronts will come to a crawling halt around the N Midlands area tonight.

I have no doubts the ECM won this little battle. Very poor from the GFS/UKMO in my opinion.

Much better 06Z at +168 compared to the 0Z.

Edited December 29, 2009 by THE EYE IN THE SKY

[snowray]

Such a shame a downgrade from last night , i was expecting atleast a few days of these strong winds even into the south east but not now!

I think that East Kent may well end up with a decent streamer at some stage from Fri-Sat. I dont expect much up my end though, odd shower, maybe a Thames streamer, but hardly classic snowfall.

Then we have the battle ground next to look forward to.

Edited December 29, 2009 by snowray

[sandstorm2]

Have to be honest I don't know why you see this as a downgrade because I said last night that for E Anglia/Kent the window of opportunity is very small i.e 24-36hrs. This remains the case with Friday offering the best prospects for convective snow in this region.

Beyond this and to be honest the positive is it remains cold and as we all know surprise snowfall often occurs.

Looking at the charts for +144 and to be honest I cannot believe some are disappointed. I would much rather have a block of HP over Greenland than a deep PV.

Have to agree with you there, the charts are still showing very cold weather and in comparison to recent years, is this not what al the cold lovers have been waiting for?

SS2

[kold weather]

ECM De Bilt ensembles, still cold around New Year period but it is notable how they are from the 2nd weekend of the New Year, milder

http://www.knmi.nl/e...agse/index.html

Yep thats a trend I have to admit is a little worrying, they clearly are suggesting the heights decaying and being replaced by a milder flow...of course thats a little while away yet however that is some way away yet and I'd fully expect things wil lchange, however we need the high to sink SE rather then due south like some of the models are suggesting, if it heads due south then we will end up seeing a milder flow...

[LomondSnowstorm]

People in Central and Southern England need to stop looking for specific snow events past 48 hours. All of the big snow events here only appeared on the models 24-36 hours before the snow started falling. As long as the cold air is in place, snow events will follow. It's far too far away to start thinking about precipitation after the band clears.

[TEITS]

Have to agree with you there, the charts are still showing very cold weather and in comparison to recent years, is this not what al the cold lovers have been waiting for?

SS2

Indeed and the good news is the 06Z roughly agrees with the GEM.

I will say to everyone that I would be very wary of the models removing our block in F.I. The models are likely to be very progressive in this respect. Remember if the block remains over Greenland then the cold remains with further snowfall potential.

Im going to have a bath but when I return I shall post a more detailed analysis of the models for all regions.

I'm not saying the 0z or 06z of yesterday were right, indeed they are going to be wrong about bringing mild air across Wales and the Midlands. However, their forecast temps for now are right and the Northward extent of the PPN is right. If you had looked at any of the FAX charts yesterday you would assumed that the front was remaining around the M4.

I see what you mean.

However if you looked closely at the fax charts there is a warm front ahead of the occluded front. The rain over your area is via the warm front and not the occlusion.