Model Output Discussion

[karyo]

Let's not give the wrong impression here , ensembles trending cold with the ensemble mean cold.

It's getting rather tiresome when people write of anything cold if its not giving 5 inches of snow.

Exactly, there is good ensemble agreement for a cold spell coming up. There will always be some ensembles going against the mean but they are just a minority.

Karyo

[tundra]

A trend growing in the models as some have said of a more amplified pattern and if we get them heights into Greenland then a very good chance of something much more wintry on offer.

[mushymanrob]

tbh i think some are getting alittle carried away with the suggested cooler weather ahead. imho theres precious little to suggest that theres anything other then 'below average' temps in fi, rather then raging cold. this is exactly what can be expected in early spring.

[nick sussex]

tbh i think some are getting alittle carried away with the suggested cooler weather ahead. imho theres precious little to suggest that theres anything other then 'below average' temps in fi, rather then raging cold. this is exactly what can be expected in early spring.

I tend to agree theres no sign of a potent wintry spell of weather and at this time of year -5 upper air just isn't good enough to deliver unless you're on top of a mountain. I might get a little more interested if a proper greenland high sets up or one last easterly but only if the PV drops into Russia and seeing as neither of these are shown then I remain lukewarm over anything notable, thats not to say theres not a chance of some wintry showers but nothing out of the ordinary.

[londonsnow]

i also agree that there is nothing massively cold and wintry showing in the immediate timeframe. i'm just grateful that there are signs of a little mobility as i'm so bored of this stagnant, dreary, dull and drizzley weather down here in london.

[grab my graupel]

12z beginning to roll out, so it's a good time to remind everyone that all the latest Model output is available, for free, on Netweather.

The Majority of the Netweather charts are in a higher resolution than those found on Wetterzentrale

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

[BLAST FROM THE PAST]

Whilst things will definetly cool down next week, we need everything to shift 200 miles east.

Doesn't it always? Could be improvements from here on in for colder set up. I touted a stormy start for March a while back and that cold will follow or be part of this development and that Spring may be delayed a couple of weeks...at least. Now we won't get as potent cold as we did in winter but below average with cold at times is likely. Yes I think the models are very much getting to grip with the 'outlook'

BFTP

Edited February 25, 2009 by BLAST FROM THE PAST

[Frosty.]

A trend growing in the models as some have said of a more amplified pattern and if we get them heights into Greenland then a very good chance of something much more wintry on offer.

I'm not sure about that, colder yes, more wintry...depends on your definition of more wintry. I can't see anything on the models that suggest a rerun of the early feb wintry spell except in the deep fantasy area of the gfs. A colder trend with wintry ppn for northern hills is about the best we can expect during next week.

[Snowaddict]

Let's not give the wrong impression here , ensembles trending cold with the ensemble mean cold.

It's getting rather tiresome when people write of anything cold if its not giving 5 inches of snow.

Very well said Eugene.

The focus is now on a major cooldown.

It might not be Ice Age 2 by any means, but it's quite funny how some continue to put down a colder outlook.

This turning cooler and gradually even colder outlook is once again borne out on the 12Z GFS Run Today.

It is also borne out in the Medium Term Met Office Outlook & Most Major NWP Outputs for the medium term.

Wintry precipitaiton might well be in short supply at lower levels, however there is still a possibility of low level wintryness as shown on GFS 12Z Operational Today.

The Min Temperatures For 12Z Noon Next Wednesday for example, one week from now are far from mild:

The trend at the moment in the medium term is towards much cooler, becoming even colder conditions with wintry conditions largely over high ground, but certainly not exclusively so.

SA.

[MR EXTREMES]

i do agree stormy is always a good start,

cold comes after stormy spell more so around the start of spring,

and blocking can come into play after stormy conditions but rarely stays for long periods of time,

but saying this this winter has had its fair share of blocking and stuck around for a fair amount of time WHEN IT HAD A CHANCE,

so there is no reason that within the next 4weeks this could become possible.

but then again the jet could be a problem as this can start its migration north early around early spring. although the jet has been the main player in some different weather in the last few years with a southerly tracking jet even around in the summer,

so this could be the case even through this spring and summer.

but overall i feel the models are now picking up on a more mobile alantic with cooler and unsettled conditions set to prevail but futher ahead could produce something different on the colder front so i take back my milder than average spring for now lol,

and sorry of topic because of the strange antics of our jet i feel this maybe a longterm trend building with a change to not as hot summers and colder winters.

[mushymanrob]

Very well said Eugene.

The focus is now on a major cooldown.

It might not be Ice Age 2 by any means, but it's quite funny how some continue to put down a colder outlook.

This turning cooler and gradually even colder outlook is once again borne out on the 12Z GFS Run Today.

It is also borne out in the Medium Term Met Office Outlook & Most Major NWP Outputs for the medium term.

Wintry precipitaiton might well be in short supply at lower levels, however there is still a possibility of low level wintryness as shown on GFS 12Z Operational Today.

The Min Temperatures For 12Z Noon Next Wednesday for example, one week from now are far from mild:

The trend at the moment in the medium term is towards much cooler, becoming even colder conditions with wintry conditions largely over high ground, but certainly not exclusively so.

SA.

'major' cool down?... of course these temps were never going to last, but we have had far more mild days then was originally expected so for it to turn colder was an inevitability. that chart for next wednesday is a joke tbh, they are notoriously inaccurate for eg at the start of this milder spell they predicted 6c! it was closer to 12c! so yes it will cool down for a while, but cold? i dont think so for the time of year, certainly ATM theres no 'ice days' or anything close. i still expect daytime max's to be within the 'normal' range albeit on the cold side going off current predicted charts.

[Paul]

Is there any risk of some adult discussion of the models rather than bickering like children over what constitutes cold and what doesn't?

[PB22]

'major' cool down?... of course these temps were never going to last, but we have had far more mild days then was originally expected so for it to turn colder was an inevitability. that chart for next wednesday is a joke tbh, they are notoriously inaccurate for eg at the start of this milder spell they predicted 6c! it was closer to 12c! so yes it will cool down for a while, but cold? i dont think so for the time of year, certainly ATM theres no 'ice days' or anything close. i still expect daytime max's to be within the 'normal' range albeit on the cold side going off current predicted charts.

Agreed Mushy. I think some people are getting ahead of themselves again. The synoptics being progged at the moment simply aren't conductive for notable cold. Colder than what we have now, yes, Cold, no.

With low pressure eventually drawing up air from the Mediterranean, it simply won't be that cold.

The 12z GFS follows earlier trends...

Low pressure starts off close to Greenland with a fair amount of cold air wrapped up within the system:

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

http://www.wzkarten.de/pics/Rtavn1202.html

http://www.wzkarten.de/pics/Rtavn12017.html

The low sinks southeast, with the colder air becoming modified as mixing takes places:

http://www.wzkarten.de/pics/Rtavn1441.html

http://www.wzkarten.de/pics/Rtavn1442.html

http://www.wzkarten.de/pics/Rtavn14417.html

The low ends up to the south, with a southeasterly feed on its eastern flank pulling milder conditions towards the UK after a brief colder spell:

http://www.wzkarten.de/pics/Rtavn1681.html

http://www.wzkarten.de/pics/Rtavn1682.html

http://www.wzkarten.de/pics/Rtavn16817.html

And we end up with a really not very cold easterly:

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

http://www.wzkarten.de/pics/Rtavn1922.html

http://www.wzkarten.de/pics/Rtavn19217.html

That is the realistic picture on what the 12z GFS is showing - and I would summarise it as the weather will turn somewhat colder for a time and increasingly unsettled. But nothing out of the ordinary for early March and temperatures are back to normal within a couple of days of the cold actually arriving. Whether it pans out like that remains to be seen, but the 12z operational is NOT good for cold/snow prospects.

This is cold:

http://www.wzkarten.de/pics/Rtavn3001.html

http://www.wzkarten.de/pics/Rtavn3002.html

Unfortunately its in FI.

[Snowaddict]

'major' cool down?... of course these temps were never going to last, but we have had far more mild days then was originally expected so for it to turn colder was an inevitability. that chart for next wednesday is a joke tbh, they are notoriously inaccurate for eg at the start of this milder spell they predicted 6c! it was closer to 12c! so yes it will cool down for a while, but cold? i dont think so for the time of year, certainly ATM theres no 'ice days' or anything close. i still expect daytime max's to be within the 'normal' range albeit on the cold side going off current predicted charts.

Hi Mushy,

In comparison with the past ten days or so, things will certainly be feeling much cooler, even quite colder in general.

Regional variances will most definately occur, however I think that the trend towards considerably cooler conditions than of late is now quite clear on the NWP outputs, with a good possibility of below average temperatures.

Any extremely potent cold remains outside of the T+120 timeframe at the moment.

Overall, a trend to considerably cooler even colder conditions is in evidence, shown quite nicely on the last few sets of GEFS Ensembles and the 12Z GFS Output Today.

Certainly increasing solar power at this time of the year will help to raise daytime maxes, but it may be rather cool or cold where cloud cover persists in stiff breezes.

Regards,

SA.

[Cheese Rice]

Models look pretty good really, britan will be under 0-minus 5 upper air for quite some time from about Sunday http://gfs.netweather.tv/gfs.20090225/12/96/h850t850eu.png and this will easily allow for wintry ppn, although wintry showers (sleet/hail) at best for the midlands southwards but i wouldnt rule out snow, anywhere north of the midlands are likely to see snow showers although more wintry in the afternoon, and perhaps lying snow above 200-250m, it looks likely that weather fronts will stall across many parts of the UK, this could give some high chances of significant snowfall http://gfs.netweather.tv/gfs.20090225/12/1...ctypeuktopo.png with a rain to snow event as these fronts appear to stay for quite some time, http://gfs.netweather.tv/gfs.20090225/12/138/ukprec.png -stalling front- http://gfs.netweather.tv/gfs.20090225/12/150/ukprec.png .

Overall not bad at all, i think some people need to lower there expectations drastically, adimtadley though it doesnt look that good for any heavy snow midlands sothwards, but with the stalling fronts the possibilitys are pretty nice

For any doubters- Meto- "snow over hills, especially in the north, and potentially even to lower levels for a time later in the first week of this period."

[yamkin]

Let's not give the wrong impression here , ensembles trending cold with the ensemble mean cold.

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

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

It's getting rather tiresome when people write of anything cold if its not giving 5 inches of snow.

Good ensembles.

I think we can all agree that it is going to get colder from Sunday.

The models are in agreement to this colder theme.

The 9th/10th March has been showing colder conditions on the models even though this is in FI.

Remember what JH would say, 'Look at the overall trends and don't take one model run as gospel'.

[Cheese Rice]

Is there any risk of some adult discussion of the models rather than bickering like children over what constitutes cold and what doesn't?

Totally agree, i guess its different for each location, if you live in London not really cold enough for anything decent, live here in N england 210m asl then obviously a lot better chances, so opinions will vary drastically, everyone should remmeber winter throws up plenty of suprise snowfalls out of the blue, and there have been many a time when the uppers are too warm for snow but it still snows, time will tell really who is right and who is wrong !

[The PIT]

Well it looks like the High is finally getting it's P45 and been shoved out of the way just outside the reliable time. At the moment it's looking like unsettled wet conditions will be moving down from the North West poss Snow for Scottish hills and the highest peaks of Northern England when you get well into FI.

So Winter looks going out after giving me in Sheffield at any rate a really storm free winter but at least it produced some snow for once.

[Frosty.]

Having glanced at the GFS 12z I can't see anything wintry until T240 hours when a major cold plunge pushes south, until then it looks like this current prolonged mild spell will last until early next week before being replaced with temps nearer average and more unsettled conditions, nothing wintry in my opinion until DEEP FI.

[Cheese Rice]

Having glanced at the GFS 12z I can't see anything wintry until T240 hours when a major cold plunge pushes south, until then it looks like this current prolonged mild spell will last until early next week before being replaced with temps nearer average and more unsettled conditions, nothing wintry in my opinion until DEEP FI.

Ahem.. http://gfs.netweather.tv/gfs.20090225/12/147/ukmaxtemp.png hardly deep into FI and it is at the warmest time of the day as well and when any ppn comes temps will easily drop a good 3-4.c

Edited February 25, 2009 by 10123

[PB22]

UKMO 12z shows the change to cooler and more unsettled conditions, with the low sinking southeast by T+144:

http://www.wzkarten.de/pics/Rukm961.html

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

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

[Frosty.]

Ahem.. http://gfs.netweather.tv/gfs.20090225/12/147/ukmaxtemp.png hardly deep into FI and it is at the warmest time of the day as well and when any ppn comes temps will easily drop a good 3-4.c

The charts next week don't inspire me much, having looked at the gfs for next week I can only see temps returning to near normal values and the only good thing about next week is seeing the azores high out of the way.

[snowray]

I'm still not in a very trusting mood when it comes to the GFS runs, maybe they should have replaced the old run as the run du parralel on Meteociel just to see how they compare. This new one was, after all, consistantly throwing up cold or very cold paterns on there from about T240 onwards since at least the middle of February! But it always stays in FI, or just brought forward and then dropped after a couple of runs.

Also the op run seem to regularly turn into something of an outlier in the the Mid Term for some reason or other, heres a good example of this, Notts Ensambles:

Notice how its the mildest member around next Thursday when the dreaded balmy beast from the Med is progged to make an apearance.

[Cheese Rice]

The charts next week don't inspire me much, having looked at the gfs for next week I can only see temps returning to near normal values and the only good thing about next week is seeing the azores high out of the way.

Did you read my post earlier? Does it convince you? (post below)

Models look pretty good really, britan will be under 0-minus 5 upper air for quite some time from about Sunday http://gfs.netweather.tv/gfs.20090225/12/96/h850t850eu.png and this will easily allow for wintry ppn, although wintry showers (sleet/hail) at best for the midlands southwards but i wouldnt rule out snow, anywhere north of the midlands are likely to see snow showers although more wintry in the afternoon, and perhaps lying snow above 200-250m, it looks likely that weather fronts will stall across many parts of the UK, this could give some high chances of significant snowfall http://gfs.netweather.tv/gfs.20090225/12/1...ctypeuktopo.png with a rain to snow event as these fronts appear to stay for quite some time, http://gfs.netweather.tv/gfs.20090225/12/138/ukprec.png -stalling front- http://gfs.netweather.tv/gfs.20090225/12/150/ukprec.png .

Overall not bad at all, i think some people need to lower there expectations drastically, adimtadley though it doesnt look that good for any heavy snow midlands sothwards, but with the stalling fronts the possibilitys are pretty nice

For any doubters- Meto- "snow over hills, especially in the north, and potentially even to lower levels for a time later in the first week of this period."

[PB22]

GFS ensembles: http://www.meteociel.fr/modeles/gefs.php?carte=1

Not very exciting for Suffolk: http://91.121.94.83/modeles/gens/graphe_en...y=99&run=12

with the mean not even making -5C until deep into FI again. Operational run was one of the milder runs for later next week, but it did have some support from the control run.

Colder further north over the Scottish highlands, as would be expected:

http://91.121.94.83/modeles/gens/graphe_en...962264150943398

And thats where any snowfall is likely to be.