Model Output Discussion 12z 18/10/2012

[ANYWEATHER]

Firstly, may I Gongratulate the Gfs that once again took the lead in the forthcoming cold spell! The Gfs was a major player in the forecasting of the dire weather we have had this summer, ecm just followed the lead! Also the so called "Indian Summer" that was progged by the models and even the BBC forecasts including the Metoffice, is fast becoming elusive, with next week being more mild than average and thats just about it!!! Although we have some way to go for the detail in the upcoming cold spell its fast becoming obvious that there is a big punch of cold weather coming down from the North! I expect the Metoffce updates to now change in accordance with the current output.....!!!!

[SMU]

The GFS has although the UKMO has done well when its in its timeframe-

Remember the stats are usually NH not europe...

S

[bluearmy]

all i have to say after seeing the way the output has developed recently is thank goodness we arent a month down the line - 'a few warm up scenarios' will be good for us come the real deal !!

[lorenzo]

This may have been posted earlier ( just catching up).. but it really does deserve stuck in a frame , blistering chart.. closely followed by the 144 chart before this one, can see this place getting pretty busy for the next week or so as the countdown to next week begins. Wonder what amazement the various Pertrbs have hidden in the GFS box of tricks.

[80sWeather]

Since 1st visiting this forum in 2006, i've stopped watching weather forecasts on tv because they do not give me a proper "weather fix".

The many great people on here make it such a vast pool of information, and give good in depth explanations as to what, and why the weather may do.

This is a post from Old Met Man from last Saturday,

"My guess is that the first sortie will more likely be from the N, as I said, so much depends on this northern block developing. Bit too early to expect any real cold yet, which is why I am following the thickness charts closely to watch for any cold pooling in the area you mention, plus the Arctic region in general. Like I said in another post, the cooling seems to be happening quite quickly.

Give it a few more days and see if the longer term trends are coming into line in the model output with regard to blocking or not.

Now where else would you find such a prediction that looks like it may well come off!!

Well done to Old Met Man

[michail]

Now that's what you call perfection! if only it was the end of Nov and not Oct....Ah well at least we'll get some early sharp frosts.

http://www.wetterzentrale.de/wz/pics/Rukm1441.gif

Edited October 19, 2012 by michail

[Cloud 10]

The GFS operational's don't look so lonely among the ensembles now.

The upper air over Greenland looks like being way above normal for the forseeable

future,so maybe more blocking episodes to come as we head into November.

[Gael_Force]

I was thinking the GFS, Steve? It seems to have lead the way progging this northerly only for the UKMO & ECM to play catch up?

I think that is the problem; GFS picks out the pattern ( predominately northerlies) well before the verification time span starts then drops it at just the point where the ECM picks it up at the start of the verification period.

[chionomaniac]

The GFS operational's don't look so lonely among the ensembles now.

The upper air over Greenland looks like being way above normal for the forseeable

future,so maybe more blocking episodes to come as we head into November.

A 15ºC 850 hPa drop in just over 24 hours. Impressive. That will be some cold front hopefully!

[Jason T]

Now that's what you call perfection! if only it was the end of Nov and not Oct....Ah well at least we'll get some early sharp frosts.

http://www.wetterzen...cs/Rukm1441.gif

"AMAZING" This time last year we was not even looking at output to what we have now. If im wrong then i will be shot down, I believe this year with this current set up, It will not matter if it's the end of November,Compared to October....It snowed here in 2007 of October and there seems to be a more Bullish anthem to the current output.......Game on. I cant do Steve Murr terms,He is way above my league ,However cant knock the GUY for sticking to his guns...Well done that MAN,There are others"AND" Praise to them all,I believe this thread is about to go into its worst"RAMP" Session we have ever seen (LONG HAUL).To end my drivel i believe a (BIG) Easterly will hit...We have the LUNG effect displayed already,Its just down to time and the displayed output to keep us all drooling.

[Weather-history]

This gave 15cm of snow to the London area on the night of 19th/20th October 1880

[Eskimo]

This gave 15cm of snow to the London area on the night of 19th/20th October 1880

Any similar factors to this year?

[Radiating Dendrite]

London I an urban metropolis now though. I think the heat island effect would put a stop to that.

Fantastic charts, but people should try and not get too carried away with snowfall. Given the time of year it would need to be the perfect set up and 144 hours out we cannot say that it will be yet.

Edited October 19, 2012 by reef
Removed two duplicate comments

[AWD]

The upper air over Greenland looks like being way above normal for the forseeable

future,so maybe more blocking episodes to come as we head into November.

One thing though is those ensembles are quiet wet so would that not suggest lower pressure over Greenland rather than higher pressure or am I reading it wrong?

[Cloud 10]

A 15ºC 850 hPa drop in just over 24 hours. Impressive. That will be some cold front hopefully!

Indeed,the weather next week looks like being "varied"

Really noticeable today how much of the model output has sharpened up on the

probable cold snap.

Another example here from the NAEFS comparing the 00z to the 12z.

00z.. 12z..

[bluearmy]

The anomalys on naefs have certainly taken on a good fi look on the 12z with greeny black and Scandinavia trough out to the end of the run. Whilst no guarantee that we will see any autumnal snowfall away from higher ground, it should certainly help to drop the SST's to the north and east.

[damianslaw]

Short term - the three main models, GFS, ECM and UKMO all show a mild southerly flow but it looks a rather cloudy affair with stubborn fog taking a while to clear as we head into early next week, so whilst temperatures should comfortably get into the mid teens, we aren't talking anything exceptionally mild, indeed the models are now suggesting any warm up will be a very shortlived affair as heights quickly retrogress NW by the middle of the week, which in turn will allow a much colder NE flow to develop and therefore sharp frosts and temps below average by day. The BBC have been saying next week will be 'mild', I think they are unwise to do this, and I am expecting them to say early next week mild only... but then becoming much colder. It's a bit odd because they aren't mentioning the word 'mild'.. very misleading..

Overall it is a settled outlook for the time of year, here October so far has been relatively dry with a good run of dry fine days, and the upcoming weekend will be the third dry weekend in a row, we never managed this once during April-September period.

Longer term - the signals for quite a protracted cold period are increasing with heights remaining strong to the NW, no sign of the PV developing to the NW and low heights to the NE, next weekend could be notably cold for the time of year with the first real threat of wintry conditions for the North, but its a long way off and those who say late october is too early snow, need only to look back at the events of late October 2008.. I'd love the last weekend of October to be a cold frosty one.. autumn colours will be superb during the 'optimum' weekend for autumn colour splendour..

[Cloud 10]

One thing though is those ensembles are quiet wet so would that not suggest lower pressure over Greenland rather than higher pressure or am I reading it wrong?

Nuuk is near the South-West coast of Greenland so is more likely to be wetter

especially with all those low pressures being shredded there!

[ICETAB]

Is that a massive snow event in some places I can see on the 18Z. Battle ground like.

[Liam J]

A few too many ales in the pub tonight I think, GFS......Biting winds and snowfall over northern/central UK?

Edited October 19, 2012 by Liam J

[SnowObsessor90]

The 18z looks quite good up until it goes into lower resolution where it obviously loses the plot again like last night lol

Edited October 19, 2012 by Anonymous21

[Met4Cast]

The 18z looks quite good up until it goes into lower resolution where it obviously loses plot again like night lol

Yeah, straight back to default, does anyone know why the GFS does this? Low Resolution really should just be scrapped or upgraded, it's next to useless at times

[Panayiotis]

Nice northerly on the ECM!

Edited October 19, 2012 by panayiotis

[chionomaniac]

Ha - just seen the 18Z. A channel low but without the snow - what a miserable Autumn day that would make down here. 5ºC with driving rain on an easterly - how much snow in two months would that give with a cold continent and cooler SST's?

Edited October 19, 2012 by chionomaniac

[SnowObsessor90]

Yeah, straight back to default, does anyone know why the GFS does this? Low Resolution really should just be scrapped or upgraded, it's next to useless at times

Too bad it had to go and do that just we were about to get to the good stuff, Grrrrrr...

Edited October 19, 2012 by Anonymous21