Model Output Discussion

[reef]

Please continue... :lol:

Old thread:

[john mac]

If UKMO verfies and there is less energy going into the northern arm of the jet, surely that will allow the high to retrogress towards our NW :lol:

[Tim Bland]

http://www.netweather.tv/index.cgi?action=charts;type=ens;sess=

Massive scatter on the 12 Ensembles. It is almost a mild outlier for the 1st half of next week and doesnt have a clue beyond that point!

Dublin is close to being a mild outlier for the majority of the run. Aberdeen in more in line which suggests that the south is going to see the coldest uppers from the easterly.

Edited January 21, 2010 by Tim Bland

[Cecil Hogmanay Melchett]

If UKMO verfies and there is less energy going into the northern arm of the jet, surely that will allow the high to retrogress towards our NW :lol:

After viewing the meteociel charts i wouldnt be to sure of a northerly on ukmo.

could turn into a damp squib quite easily.

[Guest North Sea Snow Convection]

Chance of a few snow showers for my area for a short time early next week, which would be nice as a bonus - otherwise the UKMO 12z looks dry and cold (which is also fine by me)

Not sure about the retrogression in terms of a northerly - pressure might well stay high quite close to the UK.

Either way - a nice chilly and quiet outlook

[john mac]

Well, i feel that the ECM tonight is going to be very important again tonight, will it go with the UKMO or will it flip back to yesterdays output?

[Snowyowl9]

Just seen UKMO and it shows how a HP can move quickly when another high comes in from the west,

a rex block on T144.

http://www.wzkarten.de/pics/Rukm1201.gif

I can`t see it building as far north as that but a high can shift sometimes west.

http://www.wzkarten.de/pics/Rukm1441.gif

[Thundery wintry showers]

I have a feeling that by John Holmes's calculation rule for northerlies (I can't remember the specifics, something about the location of high pressure to the W of Britain) if the UKMO had a T+168 then the northerly may well end up shunted out into the North Sea.

[Matty M]

I wouldn't rule out perhaps a few snow showers in eastern England yet.

Signs perhaps the models over did the jet slightly.

ECM colder than the GFS

I would like to Examine the differences between GFS and ECM at 72 hours, quite different.

GFS

ECM

[SP1986]

I recall a month or so ago with the advent of the new GFS update, many saying the ensembles would probably not be as important due to the higher degree of the operational ensemble compared to the others, so I suppose based on that the GFS operational cannot be simply be put down as an outlier.

However when compared to other model outputs like the UKMO it is so far at odds again but the actual evolution is probably spot on, it's just where the high is going to settle that needs verifying.

[Thundery wintry showers]

Yes, Monday & Tuesday of next week would be cold enough for snow showers in East Anglia and the southeast if the ECM was to verify, although with high pressure nearly on top of us and a relatively short track over the sea, precipitation may be limited.

[Matty M]

With regard to the longer term outlook. I personally just cannot see that block to our east shifting much.

So i don't think a northerly will be the route.

I think another period of no-mans land with perhaps the chance of the high pushing more in our favour.

I wouldn't look north for cold, i'd look east.

And i don't buy a quick killing of that high to our east, for good or bad i think its here to stay!

EDIT:

Going to put my neck on the line and say this 'easterly' will be steadily ramped up in the next few days.

[john mac]

Yes, these events in recent years have seen the model underestimate the trough disruption underneath the High so some light snow for a time would be possible based on the latest output.

Where the AO/NAO heads and the upstream pattern will determine where any mid-latitude HP eventually goes.

Yes good call Ian, the AO/NAO forcasts have been all over the place in the last week

[ChartViewer]

Amazing how the ECM & GFS seem to have 'flipped coins' this last 2 days.......GFS was showing

an Easterley of more potent source and now is watering down its synoptics....ECM is better tonight

and goes sort of with UKMO etc............Still nothing to write home about but Euros now

seem more plausible.

Regards,

CV

[nick sussex]

With regard to the longer term outlook. I personally just cannot see that block to our east shifting much.

So i don't think a northerly will be the route.

I think another period of no-mans land with perhaps the chance of the high pushing more in our favour.

I wouldn't look north for cold, i'd look east.

And i don't buy a quick killing of that high to our east, for good or bad i think its here to stay!

EDIT:

Going to put my neck on the line and say this 'easterly' will be steadily ramped up in the next few days.

I think the block will sink as thats in keeping with the upstream pattern, theres very good agreement for the block to go but this is not a problem as long as the upstream pattern amplifies enough.

Its an evolving situation but if you read my post last night the way to keep the cold is the easterly to northerly route, easterlies rarely last for very long so you need heights to rise to the north and heights to remain low in the med to remain in the cold. Overall I think the output is very encouraging and people can have their expectations too high because of the recent cold spell, this output is perfectly fine IMO, we just have to remember that the models are just about coping with the easterly so lets see what happens over the next few days.

Edited January 21, 2010 by nick sussex

[January Snowstorm]

ECM firmly backs the gfs tonight.

No notable cold for the reliable

[john mac]

I take it that comment is based upon your location JS, different for me with some cold air getting next week.

[Grimsby Snow Lover]

An interesting read from our local bbc weather presenter, well known for his cold ramping. For people like me who are a novice at understanding the model outputs I think he explains them quite clearly. Appologies if the mods find this more media related, I just felt it adds another opinion to the general model discussion.

http://www.bbc.co.uk/blogs/paulhudson/

He goes on to talk about the possible weather next week and January cet.

Edited January 21, 2010 by Grimsby Snow Lover

[Cecil Hogmanay Melchett]

I take it that comment is based upon your location JS, different for me with some cold air getting next week.

yep,very poor output for ireland and scotland but a few cold days for England,esp the south east next week.

wouldnt be suprised to see the odd snow shower in kent for example.

Longer term i agree with JS though it looks bad,very low heights to the NW means the high will sink,and sink,and sink.

[bluearmy]

thats two ecm runs which are almost consistent. whatever next ..................

yep,very poor output for ireland and scotland but a few cold days for England,esp the south east next week.

wouldnt be suprised to see the odd snow shower in kent for example.

Longer term i agree with JS though it looks bad,very low heights to the NW means the high will sink,and sink,and sink.

as long as the arctic high sinks, sinks, sinks in tandem, we'll be ok HD

[Cecil Hogmanay Melchett]

thats two ecm runs which are almost consistent. whatever next ..................

as long as the arctic high sinks, sinks, sinks in tandem, we'll be ok HD

[nick sussex]

ECM firmly backs the gfs tonight.

No notable cold for the reliable

What do people want in here! it seems unless theres ice floes in the Channel then its a waste of time! the ECM is very cold at least to 144 hrs. People need to get a grip here, do people remember some of the continual mild dross for so many winters at which point these charts would be welcomed with open arms, sometimes I wish a Bartlett would appear to give people a kick up the behind so that they realize we're very lucky to have seen the recent cold spell and also that at least the outlook looks colder! i just give up sometimes!

Edited January 21, 2010 by nick sussex

[Guest North Sea Snow Convection]

Snow showers in the south east during the first part of the week and then snow showers towards the end of the week in the west and north west according to the ECM.

Can't say fairer than that!

[La Bise]

Indeed Nick, it looks like a quiet spell might be on the way but it's a miles away from the horror show of 2006 and 2007. I think my frost counter might go up a few notches next week.

[Snowyowl9]

A much better ECM run even next thursday is cold.

http://www.wzkarten.de/pics/Recm1681.gif