Model Discussion And Chat 19th Feb.2012

[Frosty.]

but next week's cold zonality has disappeared from all model outputs with high pressure too close by to the south.

no it hasn't, the 00z's showed a cold zonal westerly blast midweek and then again next friday for the north at least, it's only the 6z which has slowed the changes down but the north still gets some cold zonal even on the 6z.

Edited March 2, 2012 by Frosty039

[Thundery wintry showers]

I've checked the GFS 00Z and I don't see where the cold zonal westerly was for the middle of next week. For the northern half of Scotland there is still potential for some cold westerlies but elsewhere the high pressure ridging up from the south should take the sting out of any such incursions, with some overnight frost but little or no shower activity.

It is possible that from next Friday onwards the jet may shift south a bit allowing more of the "cold zonality" type in, as suggested by the ECMWF ensembles.

[Frosty.]

I've checked the GFS 00Z and I don't see where the cold zonal westerly was for the middle of next week. For the northern half of Scotland there is still potential for some cold westerlies but elsewhere the high pressure ridging up from the south should take the sting out of any such incursions, with some overnight frost but little or no shower activity.

It is possible that from next Friday onwards the jet may shift south a bit allowing more of the "cold zonality" type in, as suggested by the ECMWF ensembles.

The Gfs 00z op run shows a rapidly alternating spell of zoneality next week with cold zonal westerlies for the northern half third of the uk midweek with -5 850's at least for scotland, then a risk of a similar thing happening in scotland by thursday. I think the 6z has probably moved the low too far north on sunday but we shall see, if it's ultimately modelled further south it will allow some cold pm air into scotland with wintry showers but if the 6z verifies, the wintry shower potential in scotland will be stunted.

Edited March 2, 2012 by Frosty039

[Snowy Easterly]

-16c uppers in mid March for Moscow I assume is not that uncommom, that is what that chart is showing

.

The chart i posted was an 18z ensemble member from last night, that chart has changed now since the 06z came out, but what it showed was -16 uppers in london from a stonking easterly and - 14 uppers in cornwall, this is not common for the UK on the 14th of march as that is the date it showed,

i know its FI and will not happen as it a freak event but it was the best chart i have seen for march, but if it did happen it would go down as one of the best events in history for march that is

Edited March 2, 2012 by Snowy Easterly

[Milhouse]

High pressure to the south of the UK looks to once again become very persistent during next week after the briefest of colder spells. GFS 6z has temperatures once again back into the low to mid teens as early as Thursday. Who'd have expected that just a few days ago. The ECM FI last night showed a collosal low over all NW Europe, now its one huge 1030mb High at 192h covering the whole of Spain and France. Well probably have the huge low back this evening knowing how much the models flip between different outcomes..

[snow drift]

High pressure to the south of the UK looks to once again become very persistent during next week after the briefest of colder spells. GFS 6z has temperatures once again back into the low to mid teens as early as Thursday. Who'd have expected that just a few days ago. The ECM FI last night showed a collosal low over all NW Europe, now its one huge 1030mb High at 192h covering the whole of Spain and France. Well probably have the huge low back this evening knowing how much the models flip between different outcomes..

A two day cold event with favoured northern areas seeing some wintry potential. The warm air flooding in behind from the west and becoming very windy for the far north.

At least there should be some decent rainfall for the areas that need it. Before high pressure resumes where it seems to have been for a long while.

[Geordiesnow]

Slight changes in the model output so far and it would seem that there could be a trend to collapse heights quite quickly, the GFS is keen on doing this and with the PV being as strong as it is, it would not surprise me if this is the case really. The UKMO looks similar but perhaps slightly better at keeping some sort of heights way towards Russia but it most certainly is look west rather than East for our weather, the threat of severe gales in the NW is a possibility with that massive deep low that the models are now firming up to be around the Norweigian sea area, I think this could be something to keep an eye on I feel.

Looks like that a channel low set up will occur with alot of rain potentially where it is needed but it will also feel quite cold, so quite different feel to the weather to what we have been experiencing lately.

[Summer Sun]

Apart from the odd quick low pressure system its high pressure dominated tonight

http://www.null/ds/gfs.htm

[Lewis]

Hi,

One model run later, and the GFS 12Z throws up another scenario. I noticed Ian Ferguson posted earlier about the GFS under-doing the track and intensity of the low pressure system, and it seems come this afternoons 12z, it's modelling it to be fairly deep once again.

That could bring a few problems to those in the South of the country, especially central Southern England, South Coast, SE and Kent and parts of EA, where winds for a time may touch 65-70mph with some higher exposed gusts possible, but it all boils down to which model is plotting both it's track, and it's lowest pressure correctly.

As we head into next week the Atlantic gears back up again, due to the position of the jet at first the colder zonality to the NW is kept at bay with the angle aligned for mild south westerlies to westerly, but an increasing trend on the GFS especially, backed up by the ECMWF ensembles is that a colder zonal flow may come in to play as we head into next week, bringing with it a bought of cold North Westerly winds, with some snow showers and more general organized bands of snow to the far North of Scotland, the Highlands, and some parts of far NW England.

The change will be brought about by the alignment/positioning of the jet stream, which is expected to head South.

As you can see @T90 the systems will angle themselves from a SW direction. Due to the position of the Jet;

Come T-180 the position of the jet is much more favorable for some colder zonality to take hold and influence our weather;

So it looks like we may not have seen the last snowfall of the winter. especially for areas in the North and Scotland in particular.

Lewis

Edited March 2, 2012 by ~SFL~

[johnholmes]

interesting output by the 2 models showing rainfall for this area this weekend

Met Office about 2mm and little effect from the low on Sunday

GFS 1-2mm Saturday and 25mm on Sunday from the low

Looks like I'll have to go back to basic meteorology to put something out on my web site!

[johnholmes]

Apart from the odd quick low pressure system its high pressure dominated tonight

http://www.jp2webdes...o.uk/ds/gfs.htm

see my post Gavin about differences in the model thread.

I would have thought the emphasis this evening, rather than beyond 72 hours, has to be the pssibility of 1 inch or more rain, according to GFS, for areas from about the Wash southwards, and the lack of much predicted rainfall from UK Met?

It does seem to be becoming a bit of an obsession with you over high pressure or am I imagining things?

Edited March 2, 2012 by johnholmes

[Lewis]

interesting output by the 2 models showing rainfall for this area this weekend

Met Office about 2mm and little effect from the low on Sunday

GFS 1-2mm Saturday and 25mm on Sunday from the low

Looks like I'll have to go back to basic meteorology to put something out on my web site!

I don't know about your back garden, but mine is parched. I've started to dig out a pond, and the ground is pretty firm for this time of the year which clearly highlights the lack of rainfall.

I've not been taking continuous readings of late from my weather station (when it comes to rainfall) as I've ordered a new part for my station, but I'm pretty sure that apart from a couple of hours of rain a few days ago, we've had barely anything.

As your an ex met guy, I thought this question would be best suited for you; I was out and about with the kids today and visited our local park (east park) and they've installed a new weather system/station, pretty heavy stuff, a fantastic piece of kit I was having a look around it and asked a few questions.

I asked them if they upload/export their data to the metoffice and they said they do, but I noticed they are not classed as a local observation, as there is no official observation point on the metoffice website for Hull, how would I go about myself in regards to pushing the promotion of this local observation point so the data/latest conditions is available for us all to see, like Bridlington is for example.

Lewis

Edited March 2, 2012 by ~SFL~

[johnholmes]

I don't know about your back garden, but mine is parched. I've started to dig out a pond, and the ground is pretty firm for this time of the year which clearly highlights the lack of rainfall.

I've not been taking continuous readings of late from my weather station (when it comes to rainfall) as I've ordered a new part for my station, but I'm pretty sure that apart from a couple of hours of rain a few days ago, we've had barely anything.

As your an ex met guy, I thought this question would be best suited for you; I was out and about with the kids today and visited our local park (east park) and they've installed a new weather system/station, pretty heavy stuff, a fantastic piece of kit I was having a look around it and asked a few questions.

I asked them if they upload/export their data to the metoffice and they said they do, but I noticed they are not classed as a local observation, as there is no official observation point on the metoffice website for Hull, how would I go about myself in regards to pushing the promotion of this local observation point so the data/latest conditions is available for us all to see, like Bridlington is for example.

Lewis

e mail them(Met O) but first get the approval of the site you mention to make sure they are happy for you to do that. They may already have applied and be waiting for the official visit to check on the site exposure.

[Lewis]

e mail them(Met O) but first get the approval of the site you mention to make sure they are happy for you to do that. They may already have applied and be waiting for the official visit to check on the site exposure.

Thanks John,

I'm in the area tomorrow so i'll pop and ask them that, and if they are happy i'll drop the MO an e-mail.

I would say despite it being in a fantastic position, in terms of away from immediate buildings etc, it may be exposed to direct sunlight etc, but I suppose when were talking about setups costing tens of thousands of pounds, they ain't going to over do the values like mine does in the back garden that cost me 200.

Lewis

[picog]

A two day cold event with favoured northern areas seeing some wintry potential. The warm air flooding in behind from the west and becoming very windy for the far north.

At least there should be some decent rainfall for the areas that need it. Before high pressure resumes where it seems to have been for a long while.

NAE seems to only have a couple of mm for the west midlands, a bit more further east, so I hope you are right, and the NAE is wrong!

Edited March 2, 2012 by picog

[Milhouse]

UKMO 12Z brings a brief quiter interlude on Tuesday before the Atlantic crashes through bringing a rash of showers to northern and western Britian on a brisk westerly wind. Pressure remaining high to the south so it will remain dry here. Average temperatures but feeling cool in the wind.

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

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

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

[Milhouse]

ECM 12Z has a band of rain coming down from the NW on Wednesday followed by a scattering of showers. From then on HP builds significantly from the south to affect all parts.

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

http://www.wetterzentrale.de/pics/Recm1441.html

http://www.wetterzentrale.de/pics/Recm1681.html

[Cheese Rice]

Okay well the outlook isn't as interesting as I originally expected.

Starting a fresh and ignoring what was shown on the ensembles a couple of days ago there looks to be a cool zonal driven pattern.

Kent http://cdn.nwstatic.co.uk/ensimages/ens.20120302/12/t850Kent.png

Arberdeen http://cdn.nwstatic.co.uk/ensimages/ens.20120302/12/t850Aberdeenshire.png

Likely to be PM incursions and a good shot at a northerly in the latter stage of the output. Some wintry weather likely in the strong sunshine we shouldn't see the wishbone effect too.

Anyway Sundays low looks interesting, models really conflicting

UKMO- PPN/850s

GFS

NAE (T48)

UKMO/GFS/ECM are quite similar with the track of the percipitation. While the higher resolution models NAE/YRNO/HIRLAM want it further south.

Could be some snow on its back edge for a time. ECM/UKMO would probably bring some quite significant snowfall for a time.

[Summer Sun]

ECM looking very settled into next week and beyond

http://www.wetterzentrale.de/pics/Recm961.gif

http://www.wetterzentrale.de/pics/Recm1201.gif

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

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

http://www.wetterzentrale.de/pics/Recm1921.gif

http://www.wetterzentrale.de/pics/Recm2161.gif

So once high pressure gets in it stays put to give us some very settled weather

[Geordiesnow]

ECM looking very settled into next week and beyond

http://www.wetterzen...ics/Recm961.gif

http://www.wetterzen...cs/Recm1201.gif

http://www.wetterzen...cs/Recm1441.gif

http://www.wetterzen...cs/Recm1681.gif

http://www.wetterzen...cs/Recm1921.gif

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

So once high pressure gets in it stays put to give us some very settled weather

Its not until 144 hours where things will turn more settled but even then the charts you have posted don't promise all that settled weather.

It does look like we may feel some affects of that the deep low the models are predicting with a polar airflow and strong WNW'ly winds albeit they don't last that long as pressure tries to rise. I think in general high pressure is never far away but nor is low pressure and we could be inbetween the two so variable weather could be on the cards, particularly the further North you are.

[cooling climate]

I would rather watch paint dry than what the models are showing at the moment. In fact apart

from last few days of January and first week or so of February its been that way for some

14 months now and counting. No heatwaves to really speak of in the summer and nothing really

noteworthy through the winter.

Time to give model watching a break me thinks.

[Kentish Man]

Yes after hopefully some useful rain and interesting weather this weekend the 12z ECM is somewhat uninspiring thereafter with a slow moving anticyclone stuck just to our south west. While no doubt it will produce some perfectly pleasant mild and dry early Spring weather I would much prefer some continued unsettled weather to boost our water tables now rather than turning up unwelcome in three or four months time to spoil our summer for yet another year. Some of the lesser models are a little more exciting but the omens aren't promising overall if you are looking for some real rain in the south.

[summersnow]

Wow! I'm really impressed with the way the Azore's HP has come roaring back after every colder wobble in the model output!

It's quite incredible really.

I'm pretty sure now that the extra warm anomoly, that has being pumping east/NE from the eastern seaboard of the US has been responsible for reinforcing the west side of the mid Atlantic ridge and the associated jet and powerful PV. As I've stated before, probably something to do with weak La Nina, which has also delivered a mild winter to the US lower 48.

I posted a few links a few nights back showing clearly the warm anomolies across the north atlantic this winter and in particular the very warm western edge of the North Atlantic. If anyone is keen to see these again, then please let me know!

[Suburban Streamer]

ECM/UKMO would probably bring some quite significant snowfall for a time.

ecm certainly does (in the se)! prob will change its mind again tomorrow but based on the 12z:

Edited March 2, 2012 by Suburban Streamer

[bluearmy]

ecm spreads promote a fairly strong north sea depression around day 10. depending on how close the azores ridge is, things could get quite interesting re wind.