Model Output Discussion

[Liam J]

sod the half hearted easterly, i want the FI northerly on the gfs fantastic we havent seen the gfs throw that out to much this winter, true arctic air mass 510 dam over much of the uk, polar lows likely bands of snow sinking south.....

shame it was not in a reliable time frame...

[peterf]

I was hoping no one would ask that question!!! Well I can't see a complete cave in by the gfs and the ukmo have updated their fax charts for 96hrs and 120hrs which follow their own model which suggests the ECM might be overdoing things regarding the trough energy.However the ECM might have picked up on the block being sunk but is doing this too quickly and flattens the upstream pattern out too much, the gfs 18hrs run to me though seems very quick in how it sinks the trough south over Scandi delivering that northerly. So overall I think at worst an east to se flow is at least likely for eastern and se areas but the coldest upper air is likely to head to the south into mainland Europe, the block IMO will sink though and any easterly isn't going to deliver what perhaps some people had hoped for, unfortunately low pressure isn't favourably aligned in the Med to advect the coldest air westwards but the surface cold pool will still be cold.

So overall then IMO it will turn colder but the pattern continues to evolve and for this reason as is often the case with easterlies unless pressure rises to the north the jet will eventually sink this, as we saw from the pre Xmas cold spell to keep a longlasting cold pattern you need a fluid, easterly, then northerly reload pattern, although the GFS 18hrs hints at this I'm not convinced at all, I think its earlier synoptics look plausible but question the speed at which it delivers the Scandi trough. Anyway given the chopping and changing in the output by tomorrow I may have to do a hasty re-write!

good on ya for doing it nick

[londonsnow]

sod the half hearted easterly, i want the FI northerly on the gfs fantastic we havent seen the gfs throw that out to much this winter, true arctic air mass 510 dam over much of the uk, polar lows likely bands of snow sinking south.....

shame it was not in a reliable time frame...

couldn't agree more james. shame it's FI, as you say

[weather eater]

Hope i not going over old ground.

Is thay any fact in the statement that models are set to Default?

Or another way to put it, they are set to the even larger teapot?

And is that why the messy situation is now occuring in all models

No they are not is the short answer. What you have to remember is that when people talk about default mode they mean a return to zonal conditions, by that I mean LP systems being driven across the Atlantic west to east, this is not a modern phenomena, its just the usual weather for the British Isles, always has been.

Edited January 20, 2010 by weather eater

[Bobby]

Looking at GFS ensembles they don't like quite as good as the 12z to me and the op is a big cold outlier from 28th-1st Feb. It's dangerous if that high sinks because we could end up with a pattern reset with a Euro high/Bartlett which could be very hard to shift and would be ominious for the rest of this winter I think. Ah well, we'll see what's showing tomorrow.

[Cumulonimbus Tower]

18z to me looks like a long wave pattern shift with the trough dropping into Scandi for a time and the non too robust block slipping west :lol: Nothing wierd about that evolution given the supporting signals of late And then there's Feb

Edited January 21, 2010 by ned

[kold weather]

Big differences in the way the models handle that LP coming up from the SW which strengthens our block and for once its not the normal set-up with the models.

GFS this time takes a good deal longer to blow up that low, whilst the ECM is ultra agressive with the lows deepening and that has huge knock-on effects for our HP and causes it to be shunted just too far east...meanwhile the GFS takes sooo long it ends up aiding a northerly flow!

The GFS 18z ensembles however IMO shows quite nicely the pattern I feel is most likely to evolve in the end...Barb, I agree and IMO that may well be something that happens for early Feb, maybe not a true Bartlett but possibly a broad subtropical high belt feeding in westerlies. We shall see!

[HotCuppa]

Big differences in the way the models handle that LP coming up from the SW which strengthens our block and for once its not the normal set-up with the models.

GFS this time takes a good deal longer to blow up that low, whilst the ECM is ultra agressive with the lows deepening and that has huge knock-on effects for our HP and causes it to be shunted just too far east...meanwhile the GFS takes sooo long it ends up aiding a northerly flow!

The GFS 18z ensembles however IMO shows quite nicely the pattern I feel is most likely to evolve in the end...Barb, I agree and IMO that may well be something that happens for early Feb, maybe not a true Bartlett but possibly a broad subtropical high belt feeding in westerlies. We shall see!

hehe rain then?

[Eugene]

HP ruling the roost again this morning, i remain very happy about a prolonged dry cold spell to dry the countryside out, with HP around you can always have retrogressing highs pop up at short notice, cant understand why anybody would want a reset and then most if not all winter is gone before you know it until cold blocking patterns return in the spring.

Very dry ensembles indeed.

[Eugene]

ECM 00Z has come aboard now so much for ECM being the best model

[yamkin]

ECM 00Z has come aboard now so much for ECM being the best model

I am not surprised ECM 00Z has come on board :lol:

Edited January 21, 2010 by yamkin

[Eugene]

Me neither yamkin, can't fathom why others couldn't see the same, of course the usual moaners will still not be happy with ECM 00Z as they want the absolute perfect -15C 850 hPa raging easterly but this run is a MASSIVE improvement on last nights ECM 12Z, look at this T+216 hrs chart on wetter and then check last nights T+240 hrs before it updates.

http://www.wetterzen...n/fsecmeur.html

http://www.wetterzen...cs/Recm2161.gif

Edited January 21, 2010 by Eugene

[PB22]

Finally, and as many expected, something of a middle ground now being met by the main models this morning. There's now reasonable agreement for the weakest of easterlies to affect southern Britain, whilst further north and west south-westerlies are now the order of the day:

http://www.wzkarten.de/pics/Rtavn1201.html

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

http://www.wzkarten.de/pics/Recm1201.html

After that, it then looks like high pressure may become established to the west of the UK, feeding in milder and cloudy north-westerlies as Atlantic air comes up around the top of the high:

http://www.wzkarten.de/pics/Rtavn1921.html

http://www.wzkarten.de/pics/Recm1921.html

Of course, if we can get an Atlantic high in place, it can help us to get a cold northerly, but only if heights over Greenland rise. GFS operational decides against this on the 00z run, but ECM is hinting at something along these lines:

http://www.wzkarten.de/pics/Rtavn2401.html

http://www.wzkarten.de/pics/Recm2401.html

The GFS ensembles really don't look at all inspiring:

http://www.wzkarten.de/pics/MT8_London_ens.png

http://www.wzkarten.de/pics/MT8_Manchester_ens.png

http://www.wzkarten.de/pics/MT8_Aberdeen_ens.png

At least the ECM has backed away from that zonal flow it had last night and looks to have settled down this morning, but overall it looks like it could be another couple of weeks of valuable winter time gone before any snow potential returns.

[Duane S.]

Finally, and as many expected, something of a middle ground now being met by the main models this morning. There's now reasonable agreement for the weakest of easterlies to affect southern Britain, whilst further north and west south-westerlies are now the order of the day:

http://www.wzkarten.de/pics/Rtavn1201.html

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

http://www.wzkarten.de/pics/Recm1201.html

After that, it then looks like high pressure may become established to the west of the UK, feeding in milder and cloudy north-westerlies as Atlantic air comes up around the top of the high:

http://www.wzkarten.de/pics/Rtavn1921.html

http://www.wzkarten.de/pics/Recm1921.html

Of course, if we can get an Atlantic high in place, it can help us to get a cold northerly, but only if heights over Greenland rise. GFS operational decides against this on the 00z run, but ECM is hinting at something along these lines:

http://www.wzkarten.de/pics/Rtavn2401.html

http://www.wzkarten.de/pics/Recm2401.html

The GFS ensembles really don't look at all inspiring:

http://www.wzkarten.de/pics/MT8_London_ens.png

http://www.wzkarten.de/pics/MT8_Manchester_ens.png

http://www.wzkarten.de/pics/MT8_Aberdeen_ens.png

At least the ECM has backed away from that zonal flow it had last night and looks to have settled down this morning, but overall it looks like it could be another couple of weeks of valuable winter time gone before any snow potential returns.

I agree pretty much with that summary.

The ECM looks a lot better than it has on its previous two runs so that in itself is already a big positive though. Looking at the NAO forecast I don't think it is as gloomy as some are portraying it to be. There certainly looks to be a window come the end of the month for height rises over Greenland, this could lead to all manner of interesting setups there after, good and unfortunately not so good. A potent Northerly still looks on the cars come the end of the month, it's whether it is for the UK or Scandinavia that has to be shored up yet (and that won't be for a while!)

[bluearmy]

i suggest that events off the eastern seaboard and the pole will dictate our weather as we approach the back end of next week. (ie. beyond the southeasterly flow). whilst the eastern seaboard may have decent x model agreement, i doubt the polar pattern will be settled for a while yet.

[Frosty.]

Disappointing 00z output this morning, the gfs Northerly has all but vanished from the 18z last night and we are left with rPm air at best mixed with Tm flow. The ecm has been forced to backtrack but the E'ly is pretty lame with the high further south and eventually it all collapses anyway, likewise the ukmo E'ly is now inferior to recent days. The only bright spot is the ecm in late FI with a N'ly blast but given the poor performance of the ecm in the last few days I wouldn't hold out much hope of that occuring. So to sum up, the ecm has improved a bit since yesterday but the other models are showing a less wintry outlook than before!

[snowmadchrisuk]

Slightly better this Morning , although It is not good to see GFS backing down slightly in the Medium term with height's not getting far enough North . I wouldn't call it middle ground because the GFS and ECM are totally different. All the energy that ECM had progged to our North East has now been removed from it's run , hence the High doesn't really sink, but the GFS is now showing this energy and sinking the High , If anything in the +144 time frame then ECM is now showing what GFS was and GFS is now showing what ECM was.

[MR EXTREMES]

im a moaner this is not bad at all,

its clear a beast from the east will happen.

whats also clear maybe not very prolonged but heres some charts today.

also we must remember a ssw event is on the cards aswell not sure about the the pv position but so far so good.

pretty good.

gfs is very messy indeed.

Slightly better this Morning , although It is not good to see GFS backing down slightly in the Medium term with height's not getting far enough North . I wouldn't call it middle ground because the GFS and ECM are totally different. All the energy that ECM had progged to our North East has now been removed from it's run , hence the High doesn't really sink, but the GFS is now showing this energy and sinking the High , If anything in the +144 time frame then ECM is now showing what GFS was and GFS is now showing what ECM was.

its also worth saying its more likely the gfs is wrong and ecm is right and im sure gfs later will back down and come more inline with ecm.

[karyo]

At least the ECM has backed away from that zonal flow it had last night and looks to have settled down this morning, but overall it looks like it could be another couple of weeks of valuable winter time gone before any snow potential returns.

This sounds like we haven't had any snow and ice so far this winter!

Anyway, I am happy with this mornings model output, as it looks pretty good for the January CET and that's good enough for me!

Karyo

[Polar Continental]

The ECM has now jumped on board with the easterly, not surprised this 'moaning', it was always three main models against one as I mentioned last night.

I remember putting a post on here just before Christmas when the ECM waited until the final hour before it picked up the right signals, it has done it again. So the ECM does seem to have problems with easterly scenarios at times.

Anyway back to the easterly, this will be a mainly dry but cold one, no snow really, except at first in eastern counties. Pressure will be to high to support snow showers, also upper air will not be particularly cold. There will be little difference at the surface though to the last cold spell over England and Wales, so expect hard night frosts.

Ironically the ECM produces a northerly around T192, where as the GFS and GEM which were first to show a Greenland high at that juncture have now dropped the idea.

[snowmadchrisuk]

im a moaner this is not bad at all,

its clear a beast from the east will happen.

whats also clear maybe not very prolonged but heres some charts today.

also we must remember a ssw event is on the cards aswell not sure about the the pv position but so far so good.

pretty good.

gfs is very messy indeed.

its also worth saying its more likely the gfs is wrong and ecm is right and im sure gfs later will back down and come more inline with ecm.

I think people are to quick to diss the GFS at the moment bad boy. The first cold spell was GFS's Call and so was next week. I think the new GFS is great at picking out trends .

I'm just trying to work out now the precipitation situation , It is all going to depend on how high our pressures are and exactly how far North our High get's. METO update should be a good one today .

Edited January 21, 2010 by snowmadchrisuk

[Frosty.]

its also worth saying its more likely the gfs is wrong and ecm is right and im sure gfs later will back down and come more inline with ecm.

it's also worth saying the gfs was right and ecm was wrong and that next week it's far from certain which model is going to be right.

[snowmadchrisuk]

it's also worth saying the gfs was right and ecm was wrong and that next week it's far from certain which model is going to be right.

Dam right , it's a good Job the models arn't real people . The GFS keeps calling it and the ECM get's it wrong but the ECM still manages to keep getting all the credit for it.

[The Weather Dragon]

I am impressed with GFS this time - i trusted it's consistency - it is also good at spotting northerly outbreaks in the medium range - yesterdays 12z ECM is truly in the bin. ECM follows GFS (this time) - as I have stated previously a cold week with some snow next week - followed by retrogresion and a potent northerly as the PV splits

[Snowyowl9]

As been said all above better models on average and had a meeting overnight,GFS 6z will look colder no doubt.

http://91.121.93.17/pics/Rtavn1201.png

UKMO is the model thats stayed the same since yesterday.

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

As for ECM,a dry outlook is welcome,cold next week except for scotland N ireland and NW england with a more milder SW-ly still dry and not all that mild actually.

http://www.wzkarten.de/pics/Recm1441.gif

It`s like ECM has been swapped with yesterdays GFS not so much for the easterly as it doesn`t make it right across but showing the N-ly late on and HP over to the west,and no SW-lys like yesterday.

Edited January 21, 2010 by Snowyowl9