Model Output Discussion

[kold weather]

Right carry on here folks, remember to keep on topic and respect others!

[MP-R]

This chart particularly interests me for obvious reasons. A rain turning to snow scenario by the looks of it.

http://www2.wetter3.de/Animation_06_UTC/180_30.gif

Problem is, it doesn't tie in with the H500 T500 charts.

[Harsh Climate]

This chart particularly interests me for obvious reasons. A rain turning to snow scenario by the looks of it.

http://www2.wetter3...._UTC/180_30.gif

Problem is, it doesn't tie in with the H500 T500 charts.

I think thats 180 hours away mate, I wouldnt look anything into that

[johnholmes]

fr the previous model thread

what on earth is

underwent RACY as it entered the west English Channel before racing NE-please Nick

,I do keep asking for all of us to explain accronyms until such time as they are put in the Guide section?

[Nick F]

fr the previous model thread

what on earth is

underwent RACY as it entered the west English Channel before racing NE-please Nick

,I do keep asking for all of us to explain accronyms until such time as they are put in the Guide section?

Apologies, RACY is an accronym for Rapid Cyclogenesis

18z GFS back to a deep low on Sunday tracking NE over N France.

[Freezing-Point]

In comparsion from the 12-18z the high is sitting further west allowing a NE flow to develop. Perfect for snow showers in my region as we have seen several times this winter so far.

[I remember Atlantic 252]

yeah NE'ly toppler on 18Z for 3rd March, looks dry here, but only snow for NE E and SE England, maybe I want spring now

[nick sussex]

Apologies, RACY is an accronym for Rapid Cyclogenesis :lol:

18z GFS back to a deep low on Sunday tracking NE over N France.

Is there any chance that the storm might track further west or is this a case of me desperately hopecasting? In terms of wind speeds do you have an idea as to what to expect down here? Given last year please tell me this won't be as bad!

[bluearmy]

much of the extended ens output places the upper high somewhere betwen iceland and scotland. if this verifies, the behaviour of the euro trough will dictate what this block delivers for the UK. remembering a couple of weeks ago, the trough set up too far east and the block filled the void which kept any strong flow mainly in the far se and especially eastern kent. no reason why this possible set up for later next week cant deliver something quite wintry for the south of the UK - plenty of if, buts and maybes to get the orientation of both the block and the trough right for us. whatever happens, cold not mild is the way the first half of march looks to pan out.

[kold weather]

Yep though its still not as tight as the other models Nick.

Anyway colder run from the 18z with a possible snow event with the upper high being further north on this run with a pretty cold NE airflow, though maybe a little too cold I suspect but the ensembles will be interesting, however the high does start to very slowly sink back SE over time.

Still hopefully its a good trend that remains in place, I just hope it remains with the drier idea into FI!

[johnholmes]

as posted earlier Nick S (thanks Nick F for the explanation) the models seem to have difficulty with most cases of lows arriving from this direction. I don't think there is going to be a major change in direction but it is possible it could be further west but not by much. Its depth is also causing the models to disagree so it may be late tomorrow before we can really start to have confidence in its overall path and depth. By then, hopefully, both NAE and GFS will have the same hymn sheet.

[Nick F]

In comparsion from the 12-18z the high is sitting further west allowing a NE flow to develop. Perfect for snow showers in my region as we have seen several times this winter so far.

Yes, the NE'erly sources some quite cold air from Scandinavia. With SSTs of 4-5C in the south N Sea and 5-6C in the northern half, we should perhaps see less modification at the surface than say in Dec and Jan. Though of course with a stronger sun now, lying snow maybe shorter-lived if the sun pops out, especially in the south.

[nick sussex]

as posted earlier Nick S (thanks Nick F for the explanation) the models seem to have difficulty with most cases of lows arriving from this direction. I don't think there is going to be a major change in direction but it is possible it could be further west but not by much. Its depth is also causing the models to disagree so it may be late tomorrow before we can really start to have confidence in its overall path and depth. By then, hopefully, both NAE and GFS will have the same hymn sheet.

Thanks John, hopefully I won't have been carted away by then suffering from nervous exhaustion! At the moment because of the lack of model agreement its just dragging the pain out! It's the unpredictable nature of this type of storm development thats a big concern, Meteo France website still don't have anything in terms of an early warning but even tonight theres problems further into central France with strong winds on the southern flank of that low near the Channel.

http://www.meteociel.fr/phenomenes_meteo/index.php

You look at that and think if that system can produce that what on earth will the next low do! Anyway I need to calm down before I blow a gasket!

i think you may be in panic mode nick. looking at the runs at the moment, i'd say any damaging winds are well to your nw. i'd be surprised to see a correction se on this now unless the feature doesnt deepen as much in which case its not so dangerous for you anyway.

Yes you're right I'm in panic mode especially with a forest right next door to me! The thing that worries me is if the low doesn't deepen initially taking it onto a more ene track then decides to deepen later. Anyway I think I'd better just get a grip before I drive everyone crazy!

[Nick F]

Is there any chance that the storm might track further west or is this a case of me desperately hopecasting? In terms of wind speeds do you have an idea as to what to expect down here? Given last year please tell me this won't be as bad!

I echo what bluearmy says, from current charts worst winds look to be further west over N and NW Spain and then further NW over western France (probably north of Bordeaux up to Nantes), where you are you may get some gusts to gale or strong gale force though, particularly as the cold front moves through from the west.

The build of pressure next week is certainly going to be welcome after this current Atlantic spell, we have had little in the way of gales this winter, so perhaps Sunday's low is trying to re-address the balance!

[nick sussex]

I echo what bluearmy says, from current charts worst winds look to be further west over N and NW Spain and then further NW over western France (probably north of Bordeaux up to Nantes), where you are you may get some gusts to gale or strong gale force though, particularly as the cold front moves through from the west.

Thanks Nick, I'll just have to keep my fingers crossed and hope for the best.

[kold weather]

Yes, the NE'erly sources some quite cold air from Scandinavia. With SSTs of 4-5C in the south N Sea and 5-6C in the northern half, we should perhaps see less modification at the surface than say in Dec and Jan. Though of course with a stronger sun now, lying snow maybe shorter-lived if the sun pops out, especially in the south.

Yep, also at this time of year showers can keep going far more inland which would be decent as well. Will be interesting to see what the ensembles show, hopefully the ensembles will be as keen as the GFS op run for the NE flow.

Certainly going to be very windy even if the GFS slightly less tight low comes off for France.

[Freezing-Point]

Yes, the NE'erly sources some quite cold air from Scandinavia. With SSTs of 4-5C in the south N Sea and 5-6C in the northern half, we should perhaps see less modification at the surface than say in Dec and Jan. Though of course with a stronger sun now, lying snow maybe shorter-lived if the sun pops out, especially in the south.

My thoughts entirey, but I can add, that while the added radiation will melt snow, it could also have a convective effect on the showers being driven inland, producing some heavy showers.

[NorthantsSnow]

Absolutely MAJOR snow event showing on the 18z for midweek next week. Please let it be!

http://charts.netweather.tv/gfsimages/gfs.20100225/18/132/prectypeuktopo.png

If it came off we'd be looking at 40cm in parts of the Midlands from that little beauty.

[Liam J]

gfs 18z going for very cold and snowy weather to continue into the first week of spring which is not unusual at all, with some very large snowfalls potentially on the horizon, as if scotland needs any more after there severe weather this week.

snow event for northern england showing start of next week and through out the week widespread.

nice looking snow depth chart....

[kold weather]

Absolutely MAJOR snow event showing on the 18z for midweek next week. Please let it be!

http://charts.netwea...ctypeuktopo.png

If it came off we'd be looking at 40cm in parts of the Midlands from that little beauty.

Yep for sure, though that set-up probably isn't likely to occur because the low sinks sooo slowly, still if the boundary sets up far enough north its not impossible I suppose!

Still decent ensemble agreement for a NE/ENE airflow to develop followed by a slow sinking of the upper high. Its worth noting some ensemble members really are quite cold in terms of upper temps with the NE/ENE flow.

[MKN]

Absolutely MAJOR snow event showing on the 18z for midweek next week. Please let it be!

http://charts.netweather.tv/gfsimages/gfs.20100225/18/132/prectypeuktopo.png

If it came off we'd be looking at 40cm in parts of the Midlands from that little beauty.

Remember its just 1 model and 1 run. Chance of that occuring like that is about 1% at best

[Ben_Cambs]

Most of the models this morning have the HP for next week centred NW of Scotland, so IMO that would lead to a mostly dry, cold and sunny week with harsh frosts at night. The proper cold dives into mainland Europe because of this, on ECM especially. GEM is the only expection, with possibly some snow for southern and Eastern areas, but its way too far off to talk about that. I haven't much idea where UKMO 0z is going from its T+144 chart, with the centre of the high around the Faroe islands, but IMO the cold would dive straight into Europe like it does on ECM.

For Sunday's low, ECM and UKMO have the centre of the LP around 970mb, which would could potentially deliver gusts of up to 60mph on the south coast at times, GFS has the LP centre around 975mb, with the centre located when it hits our shores around the North Coast of France. And again, the "lesser" models like NOGAPS have the LP pretty deep, and I'm glad this model isn't taking seriously! I hope Nick S misses the worst of the winds and rain!

Looking like a dry day though for N.Ireland, Scotland and the far North of England

[Coast]

Morning folks!

Remember the thread here is open for general discussion on Sunday's low and it's potential.

[Eugene]

Looks like a cold end to a wonderful winter with some wintry precip possible on the back edge later on sunday as we pull down some cold uppers, a nice crisp start to March too

http://www.wetterzentrale.de/pics/Rtavn9010.png

Further ahead very good agreement on HP taking over lying just to our north with a continental feed in southern UK where we go from there is what we`ll find out in the next week

[Craigers]

Looks like a cold end to a wonderful winter with some wintry precip possible on the back edge later on sunday as we pull down some cold uppers, a nice crisp start to March too

http://www.wetterzentrale.de/pics/Rtavn9010.png

Further ahead very good agreement on HP taking over lying just to our north with a continental feed in southern UK where we go from there is what we`ll find out in the next week

i am liking the look of that chart and would be a great birthday treat but whats the chances of this setup though?