Model Output Discussion 12z 18/10/2012

[Cheshire Freeze]

As I said before, it's only October. Winter's still six-weeks' hence...

Also snow is snow. I don't care what month it falls in.

Edited October 18, 2012 by CreweCold

[Paul]

Are these right as they seem odd?

http://www.meteociel...1&ville=Londres

All in agreement!

I think that's one of the problems of putting all the plots on one page - not enough space on the scale. I prefer the single charts for that reason

http://www.netweather.tv/index.cgi?action=ensviewer;sess=

(12z running currently).

[Frosty.]

That must be one of the most settled gfs runs I have seen for some time, next week would become very anticyclonic and then it just continues until near the end which is early november. One key thing about next week would be that although it looks like turning very mild or even warm for the time of year during the first half of next week, the mildness then begins to drain away after midweek with daytime max temps dipping to 10-11c eventually and overnight would be cold enough for a touch of frost, especially in rural areas where temps could fall close to freezing, some cooler air begins to filter in from the east or northeast as the orientation of the high changes. I don't buy this run, i'm very unconvinced we are going to have such a prolonged benign period, indeed I still think we have a chance of an arctic outbreak even if it's not as full on as some of the recent gfs op runs, the jury is still out as far as i'm concerned but if this run did verify, at least we would get some good drying weather for the farmers and people who got flooded out of their homes and businesses recently. I don't think the very mild spell next week was ever in any doubt, but after midweek it's all to play for IMO.

Edited October 18, 2012 by Frosty039

[SMU]

http://www.meteociel.fr/modeles/gefs_cartes.php?code=15&ech=6&carte=1&mode=0

knock yourselves out PPL

S

[Cheshire Freeze]

I think that's one of the problems of putting all the plots on one page - not enough space on the scale. I prefer the single charts for that reason

http://www.netweathe...ensviewer;sess=

(12z running currently).

Also, when I clicked on the link it was just the short ensembles showing (upto a week hence) which accounts for why the members only start diverging at the end.

Edited October 18, 2012 by CreweCold

[phil nw.]

Are these right as they seem odd?

http://www.meteociel...1&ville=Londres

All in agreement!

They are not finished yet.Have a look a later on they should make sense then.

[AWD]

They are not finished yet.Have a look a later on they should make sense then.

I know they only go out until T180 but you still don't normally get such agreement right out to then.

[bobbydog]

for those talking about 'poor runs', 'pub runs' missing data etc,

worth taking note of this from NOAA website-

"GFS - GLOBAL FORECAST SYSTEM. THIS REFERS TO ANY OF THE GLOBAL MODELS RUN AT NCEP FOUR TIMES A DAY THAT USED TO BE REFERRED TO AS THE MRF AND AVN MODELS. THE MODEL RUN INITIATED AT 00Z (00 GMT) IS CURRENTLY THE ONLY ONE USED BY CPC IN ITS OFFICIAL BLEND FORECAST - ALTHOUGH THE OTHERS CAN BE CONSIDERED BY THE FORECASTER IN FORMULATING THE TEMPERATURE AND PRECIPITATION FORECASTS."

[Cloud 10]

I know they only go out until T180 but you still don't normally get such agreement right out to then.

Looks like they have updated fully now AWD.

[AWD]

Looks like they have updated fully now AWD.

Thanks Cloud 10. I vote for Pb 2.

Not as "clusterous" as I thought, with the Operational & control well supported until deep FI.

Edited October 18, 2012 by AWD

[A Winter's Tale]

Good evening.

Tonight rain should continue over a good part of Scotland but should lose its intensity as it tries to clear north east. Dry in the borders and north west higlands. A largely overcast night for Ireland seems likely with precipitation in the north disapearing. A mostly overcast night for Wales seems likely too with some showers near the coasts, much of north west England could also stay cloudy too whereas the north east, south west and central areas may have some clear spells but a front close to the continent should bring some rainfall to the far south east. Minimum temperatures should be 8 to 13C. Damp conditions should continue for much of the day across some parts of Scotland but it'll become a lot lighter and patchier in nature, some sunny spells likely in the north west and rainfall is expected for Shetland. Mostly cloudy skies for Ireland but sunny breaks are expected at times. Sunny spells for much of NE England, the Midlands and the south west, cloudier in the north west with a few showers and cloud cover and rainfall still present in the south east. Some sunny spells are likely for Wales with one or two showers at times. Maximum temperatures of 9 to 14C. Friday night could be overcast for Scotland, Ireland, western areas and the south east with clear spells further inland in England and still the possibility of some rainfall for the coastline of the south east. Light rain may continue across the grampians and one or two showers in the irish sea. Minimum values of around 6 to 12C.

Saturday should be a mostly dry day other than some rain for the northern isles and some good spells of sunshine are likely other than the coastal regions of western and north eastern Scotland, western Ireland and south eastern England and some cloud cover may be present for coastline of the irish sea. Maximum temperatures of 10 to 14C in major cities. Saturday night could be quite cool with lows of 6 to 10C in cities, cloud cover possible for northern Scotland and Ireland, widespread clear skies for England and Wales. A threat of rainfall for the far south east.

And at the moment, rain seems likely to affect the south and south-east of England on Sunday whereas Wales, the rest of England and good parts of Scotland and Ireland could enjoy widespread sunshine. Maximum temperatures of 12 to 14C. The damp conditions across the south east may move further north across England overnight, hardly persistent or heavy but scattered light rainfall seems likely across Wales and England in which looks like an overcast night. The best of any clear night skies in the north west of Scotland. Minimum temperatures of 8-13C.

Sunshine could be restricted to some southern and central parts of England on Monday. Cloud cover and rainfall spreads to Scotland and Ireland but some cloud cover and light patchy rain may linger in across some parts of Wales and England, especially the north. Maximum temperatures of 12 to 17C. By Monday night, the rain should only be confined to the northern isles, but a largely overcast night for everywhere other than the southern third of England. Minimum temperatures of 10 to 14C.

Indian summer-like weather looks like persisting for the start of next week across southern parts of the British isles. In previous runs, the GFS model did have a trend for an early northerly blast later next week but the high pressure has sinked further south and east and it seems likely that Scandinavia and western parts of Siberia may have blast of some cold and snowy conditions so I would say a no to a northerly for the British isles next week but it is only October not the middle of winter so I think it would be best to avoid getting ahead of ourselves and to first of all, focus on the conditions for the next 7 days. Beyond next week, all the possible outcomes in my opinion are all up in the air and it's really difficult to put a finger on any likely scenario.

[Cloud 10]

Thanks Cloud 10. I vote for Pb 2.

Not as "clusterous" as I thought, with the Operational & control well supported until deep FI.

LOL,"clusterous" what a great word!

Going a bit further afield,its looking good for Greenland mild rampers.

[Liam J]

12z ECM rolling out and it's pretty much a case of as you were (00z)

Depression further east closer to Norway by T144 - Looking good....

Arctic surge deflected eastwards

Edited October 18, 2012 by Liam J

[Cheshire Freeze]

12z ECM rolling out and it's pretty much a case of as you were (00z)

Depression further east closer to Norway by T144 - Looking good....

Pretty much identical to UKMO at 144 hours

[ICETAB]

Arctic surge deflected eastwards

Yeah, one things for sure though, it won't look like that at T0, plenty of room for improvement. Could go the other way but it looks better for cold than yesterdays run. Things just need to move west a little, which I find odd because not to long ago things look like they could be to far west. Lots of changes to come I'm sure.

Edited October 18, 2012 by ICETAB

[ANYWEATHER]

Yeah, one things for sure though, it won't look like that at T0, plenty of room for improvement. Could go the other way but it looks better for cold than yesterdays run. Things just need to move west a little, which I find odd because not to long ago things look like they could be to far west. Lots of changes to come I'm sure.

Yes I do agree with your comments. Gfs has shyed away from its previous very cold run whilst the ecm had kind of trended towards gfs . Altogeather , it does look like its gonna get pretty cold after a few warmer days next week ,but as always the devil will be in the detail, and there will be many more wobbly runs from gfs and ecm but the general trend is for a colder outlook towards months end.

[cold snap]

wow .ecm at 240 is epic.think people may have turned it off at in the earlier frames.if we get a decent enough greenland high we are in buisness ,i see this as the only hurdle.

[ANYWEATHER]

Potential here from ecm for you coldie fans...

[Gibby]

Good evening. Here is the review from my perspective of the 12zs from GFS, UKMO and ECM.

All models are fairly clear on the pattern beteen now and the middle of next week. The current low pressure over Ireland continues to fill and lose it's identity leaving a slack and gentle Southerly flow over the UK for the start of the weekend. A front lying close to the SE moves NW on Sunday afternoon with rain and freshening Easterly winds. Behind it winds veer SE and lighten again bringing a warm and rather humid flow across the UK for the early days of the week with temperatures well above normal for late October, especially in the SE.

GFS then shows a slow cooling through the week to temperatures nearer to normal by the weekend. The weather will be mostly dry, a little breezy in the South but calm in the North with fog and frost problems becoming quite extensive by the weekend. Through FI High pressure splits East and West of Britain allowing a slack Low pressure to drift South over the UK with attendant rain at times. Late in the run High pressure in the Atlantic becomes the driving force to the UK weather with rain clearing the South with a cold Northerly flow with wintry showers in the North and East towards the end of the run.

The GFS Ensembles show the operational coming much more in line with the majority of members thinking tonight in that the temperature levels will become close to the long term average for late October. There are still a few much colder options but they are in the minority. Rainfall too becomes much less than of late for areas North and South indicative of High pressure close to the UK.

The Jet Stream currently troughing sharply South to the SW and returning North over the SE of Britain gradually becomes diffuse and disorganized over the coming week or so with a flow both North and South of Britain, the strongest one to the North.

UKMO for noon on Wednesday shows High pressure over Southern Scandinavia and Low pressure to the NW of Spain. Winds will be light to moderate East to Southeast with relatively warm conditions still with some warm sunny intervals in places. It will also be dry for all.

ECM shows a similar pattern to UKMO with a gentle relaxing of the warm conditions later next week as cooler air spreads in from the NE. High pressure slides Southeast over the UK keeping things settled with an increasing risk of frost and fog night and morning, slow to clear in places. The final day chart of the run shows an Arctic blast sweeping South over Britain with some early snowfall for the Scottish mountains should it verify

In Summary tonight GFS has come into line with a more realistic outcome for the weather over the latter stages of next week and beyond, while ECM has taken a previous GFS plan at Day 10. However, leaving specifics aside (including the Day 10 ECM) the general trend to be taken from tonight's output is a period of more settled and quiet conditions is on the way with temperatures nearer to the late October average. With the Anticyclonic nature of conditions likely over the coming week or two fog could become one of the only factors of the weather to bother anyone with most people taking solace from the drier weather allowing water tables to reduce somewhat.

[Met4Cast]

Haha!

GFS goes "no" to the Northerly and now the ECM is showing it. I'm sure these two models are having a sibling rivalry at the moment and just disagreeing for the sake of it

[SMU]

http://www.meteociel...H1-168.GIF?18-0

See people its trending to the forecast output-

remember the 228 Chart on the 16th that I have used my forecast base on-

http://modeles.meteo...12-0-228.png?12

Now look at the ECM 12z-

http://www.meteociel...M1-168.GIF?18-0

Not so different now--

The ECM has followed the expected path- WHY?:- Seemless transition- THe ECM runs & the UKMO was very messy shortwave wise- & now its fairly seemless-

Just small fine tuning on the trajectory south of the cold air- which obviously has a big impact on the UK....

Thanks for the patience- all these posts arent a waste a time when a model finally starts doing what you expect to SEE

S

Edited October 18, 2012 by Steve Murr

[bluearmy]

ecm is of interest in that the 12z follows the 00z in fi by retrogressing our block to beef up the greenland high and allow the cold to arrive by a more familiar route. of course all this is window dressing to the 'real event' which continues to take place north of our lattitude. remember 'spot the ball'. there will soon be a new game - 'spot the p/v' !!

[Geordiesnow]

GFS goes "no" to the Northerly and now the ECM is showing it. I'm sure these two models are having a sibling rivalry at the moment and just disagreeing for the sake of it

Well it does not really say "no" to it, for various reasons, it just does not reach our latitude which is probably not a bad thing to keep a lid on things in here somewhat but as the models are showing, the chances of a cold shot are there if albeit a bit of an outside bet and experience tells me shortwaves stops the high over from retrogressing far enough westwards to let the floodgates open.

Slight orientation change in the high on the ECMWF which may mean more cloud especially in Eastern areas and with slightly cooler uppers, lower temperatures than the GFS model is predicting.

[Liam J]

http://www.meteociel...H1-168.GIF?18-0

See people its trending to the forecast output-

remember the 228 Chart on the 16th that I have used my forecast base on-

http://modeles.meteo...12-0-228.png?12

Now look at the ECM 12z-

http://www.meteociel...M1-168.GIF?18-0

Not so different now--

The ECM has followed the expected path- WHY?:- Seemless transition- THe ECM runs & the UKMO was very messy shortwave wise- & now its fairly seemless-

Just small fine tuning on the trajectory south of the cold air- which obviously has a big impact on the UK....

Thanks for the patience- all these posts arent a waste a time when a model finally starts doing what you expect to SEE

S

A little confused Steve, as per your commentary & posts over the last few days - in the curent developing situation taking place over northern latitudes shouldn't we be trusting the GFS to get a handle on things above the Euro models, as you have alluded to many times?

[Cloud 10]

ecm is of interest in that the 12z follows the 00z in fi by retrogressing our block to beef up the greenland high and allow the cold to arrive by a more familiar route. of course all this is window dressing to the 'real event' which continues to take place north of our lattitude. remember 'spot the ball'. there will soon be a new game - 'spot the p/v' !!

Looking at the anomaly charts for the first half of October this year and then comparing to

the same time last year is an eye opener.

Virtually complete opposites!

2011.. 2012..