Spring Model Discussion 21st March 2013 006z onwards...

[Joe Levy]

To Dartmoor possibly, but i think that would be more really unwelcome rain for the vast majority.

I disagree. The uppers for most of Devon and parts of Cornwall would be at around -2/-3 and with dew points around or lower than that, snow is quite widely possible. Perhaps the coast might see more of a wintry mixture but IF that chart came off, then it would be snow for many, if not the majority.

Edited March 22, 2013 by Joe Levy

[Mucka]

Looks like the GFS 12z is totally off on one, ridiculously progressive so unless it gets support from elsewhere it is definitely a case of bin it.

Here is a comparison UKMO/GFS 144.

Edited March 22, 2013 by Mucka

[SomeLikeItHot]

So at 144 GFS has whipped up an Atlantic super storm, to smash the block.

While the UKMO just wants to slide under.

Will be interesting to get the ECM view.

Edited March 22, 2013 by SomeLikeItHot

[snowice]

So at 144 GFS has whipped up an Atlantic super storm, to smash the block.

While the UKMO just wants to slide under.

same old gfs! That cold will be hard to shift and wont happen that fast.

[SomeLikeItHot]

Will be a Good Friday flood if the GFS pans out.

[mushymanrob]

Looks like the GFS 12z is totally off on one, ridiculously progressive so unless it gets support from elsewhere it is definitely a case of bin it.

thats exactly what they said about the gfs in late december 2010 when it was the first, by a mile, to spot the thaw that ended that freeze. the ensembles appear to support a return to something more normal next friday, so the gfs does have support! (although not exactly warm)

Edited March 22, 2013 by mushymanrob

[snowking]

thats exactly what they said about the gfs in late december 2010 when it was the first, by a mile, to spot the thaw that ended that freeze. the ensembles appear to support a return to something more normal next friday, so the gfs does have support! (although not exactly warm)

Slightly astray from the discussion, but I have long suspected that in many breakdown scenario's that the GFS has 'got correct' its because it attempted a breakdown every 3 days or so. If it carries on doing that, of course it will eventually be right when the breakdown comes.

The trouble is, you don't know which of the occasions it will actually be correct on until nearer the time. That was certainly the case in December 2010.

SK

EDIT: I should clarify this isn't me rubbishing the potential for the Atlantic to win late next week - its just an observation

Edited March 22, 2013 by snowking

[SomeLikeItHot]

thats exactly what they said about the gfs in late december 2010 when it was the first, by a mile, to spot the thaw that ended that freeze. the ensembles appear to support a return to something more normal next friday, so the gfs does have support! (although not exactly warm)

I have no doubt that the GFS will be first to spot the thaw. I believe it was in January also but it also spotted about 5 false ones on the way. As I have posted before though its also likes to have rock solid ensemble support and then do total ensemble backflips.

Still there is also some ECM ensemble support for a warm up around that date so its not out of the realms of possibility.

Edit: I see SK makes the similar point.

Edited March 22, 2013 by SomeLikeItHot

[Summer Sun]

Looks like the GFS 12z is totally off on one, ridiculously progressive so unless it gets support from elsewhere it is definitely a case of bin it.

GFS has been hinting at a warm up around the Easter weekend for the past 3 or 4 days now so this doesn't surprise me on bit not mega warm I agree but double figures is better than what we have now

Just what the doctor ordered temperature wise...........

......... but a wet Easter is looking quite likely at this stage for many areas

Edited March 22, 2013 by Gavin.

[Mucka]

thats exactly what they said about the gfs in late december 2010 when it was the first, by a mile, to spot the thaw that ended that freeze. the ensembles appear to support a return to something more normal next friday, so the gfs does have support! (although not exactly warm)

As snowking stated, it was right by default.

I wouldn't mind seeing some milder weather either me but trust me when I say GFS has soiled itself again with the 12z run.

Here is NAVGEM 12z

Snow pushing into the South next Friday

[Mucka]

Sorry but GFS has been constantly hinting at a warm up during the Easter weekend for the past 3 or 4 days now so I wouldn't say its totally off on one

Just what the doctor ordered temperature wise...........

......... but a wet Easter is looking quite likely at this stage for many areas

Really?

Tell you what, if the SE has temps of 13C on the 29th I'm Elvis Presley.

It is way, way, way off on one and has ZERO support from other output thus far.

IF and when other output shows something remotely resembling it then it will be worthy of consideration.

Edited March 22, 2013 by Mucka

[Cheshire Freeze]

Given the GFS tendency ALL WINTER to shunt too much energy NE with associated LP, I don't know how anyone can say with a straight face it's even close to being likely to be right? Especially having looked at UKMO and NAVGEM.

This isn't a militant coldie perspective either.....given today's damp squib the thought of spring seems appealing. However, I'm with Mucka, the GFS is most likely off on one!

Also bare in mind there has been occassions recently where the GFS still hasn't modelled energy distribution correctly at 72-96 hours....let alone 144!

Edited March 22, 2013 by CreweCold

[bradymk]

No model support for GFS with Tuesday snow for SW, GEM, NAVGEM and UKMO all agree on no precip moving up from SW. Something to watch but nothing more than a GFS moment for the time being. Also no support so far for the warm up shown by GFS for end of this week. Oh and today and yday have been horrible here, non stop heaving rain with strong winds and temperatures no higher than 5c, its not BST next Sunday surely?

Edited March 22, 2013 by bradythemole

[mushymanrob]

Slightly astray from the discussion, but I have long suspected that in many breakdown scenario's that the GFS has 'got correct' its because it attempted a breakdown every 3 days or so. If it carries on doing that, of course it will eventually be right when the breakdown comes.

The trouble is, you don't know which of the occasions it will actually be correct on until nearer the time. That was certainly the case in December 2010.

SK

EDIT: I should clarify this isn't me rubbishing the potential for the Atlantic to win late next week - its just an observation

well i joked about that this morning, it certainly appears to be the milder of the big three, but im sure it shows these breakdows due to the interpretation of the data and not by 'default' (as mucka suggests) or accident. that breakdown it spotted days before the ecm or ukmo and it stuck with it every run. it is possible that this suggested breakdown will be the one!

maybe im as guilty as hoping the gfs is onto something (that has to come soon) as the coldies are hoping it isnt. i do note though that when the gfs has produced the colder run the snowfans jump ship and praise the gfs! <-<

but thats a long way off, a week away at the earliest, until then we have some very cold and unpleasant weather to endure...unless you like bitter, raw, overcast, days in spring!

[Summer Sun]

its not BST next Sunday surely?

Yes clocks go forward 1 hour in the early hours of next Sunday morning (31st)

[mushymanrob]

Given the GFS tendency ALL WINTER to shunt too much energy NE with associated LP, I don't know how anyone can say with a straight face it's even close to being likely to be right? Especially having looked at UKMO and NAVGEM.

This isn't a militant coldie perspective either.....given today's damp squib the thought of spring seems appealing. However, I'm with Mucka, the GFS is most likely off on one!

Also bare in mind there has been occassions recently where the GFS still hasn't modelled energy distribution correctly at 72-96 hours....let alone 144!

i agree though that the gfs is likely to be too progressive, even if the general evolution might be proven correct, i just dont think its wise to ignore any data... after all, the gfs is and has suggested this most likely of scenarios for the return of milder weather, so to completely dismiss it might be foolish.

[Mucka]

well i joked about that this morning, it certainly appears to be the milder of the big three, but im sure it shows these breakdows due to the interpretation of the data and not by 'default' (as mucka suggests) or accident. that breakdown it spotted days before the ecm or ukmo and it stuck with it every run. it is possible that this suggested breakdown will be the one!

maybe im as guilty as hoping the gfs is onto something (that has to come soon) as the coldies are hoping it isnt. i do note though that when the gfs has produced the colder run the snowfans jump ship and praise the gfs! <-<

but thats a long way off, a week away at the earliest, until then we have some very cold and unpleasant weather to endure...unless you like bitter, raw, overcast, days in spring!

I said it got the breakdown right by default because it is by far the most progressive model and will nearly always keep modelling a breakdown of cold 168+

Originally it had the breakdown for the 27th and slowly extended that out to around the 30th now it has bought it back forward 48 hours or so that the breakdown begins on the 28th and temps are well into double figures by the 29th for the South.

Now there will be a breakdown at some stage of course and this cold cant last but it looks set to stay well below average until the 30th at least according to all the output except this GFS run.

It is not impossible it is correct but it is barely worth considering when weighing it against all the other output.

If it repeats the dose a few times and there is a hint of support from the other models then it will no longer be way out there on its own and worthy of consideration.

Edited March 22, 2013 by Mucka

[The Northern Ramper]

If the Gfs predicts a breakdown each time a low comes in from the Atlantic eventually it will be right.

Even the blind Squirrel will occasionally find a nut.

[Vince]

Can just say hats off to Ian was only one on here that said Scotland would get this and has came off, someone even said the front won't reach Scotland...

Talking of Ian , where is he , he is very quiet considering this could be the snowiest spell in years .

come out , come out where ever you are

[-uksnow-]

Talking of Ian , where is he , he is very quiet considering this could be the snowiest spell in years .

come out , come out where ever you are

That's the exact reason why he is quiet - his job isn't to update us!

[Mucka]

i agree though that the gfs is likely to be too progressive, even if the general evolution might be proven correct, i just dont think its wise to ignore any data... after all, the gfs is and has suggested this most likely of scenarios for the return of milder weather, so to completely dismiss it might be foolish.

It would be a great deal more foolish to give it any real consideration when it has no support.

How much do you want to bet temps are not a lot lower than what GFS 12z forecast for the 29th?

You see, it is easy to say something might be right no matter how outlandish just so long as there is no pressure or consequences on being wrong.

It might be 21C in Manchester on the 29th but I wouldn't push it as being plausible.

[Summer Sun]

Well, well, well GFS continues to have ensemble support from later next week for the milder air to move in

Edited March 22, 2013 by Gavin.

[mushymanrob]

It would be a great deal more foolish to give it any real consideration when it has no support.

How much do you want to bet temps are not a lot lower than what GFS 12z forecast for the 29th?

You see, it is easy to say something might be right no matter how outlandish just so long as there is no pressure or consequences on being wrong.

It might be 21C in Manchester on the 29th but I wouldn't push it as being plausible.

there a difference though between not ignoring it and giving it any real consideration, i dont think itsthat outlandish, just over progressive, so on that we will agree to disagree

but it does have a hint at some support, the ensembles (which are often cited by the coldies when theres no real cold on the op runs ) do show a return to less cold later next week, so whilst not total support there is some hint that the extreme cold wont last beyond next friday, unlike what other runs have suggested.

then theres the anomaly charts which if my rudimentary understanding of them is correct does support something along the lines (although like the ensembles, not as progressive) that the gfs is suggesting on it 12z.

[Purga]

Well well well would GFS continues to have ensemble support from later next week for the milder air to move in

Fine if GFS can be trusted in these type of situations? I would pay more heed to the Euros as those ENS chop and changed like ..... Oh yes - the weather! LOL

[Frank Trough]

It would be a great deal more foolish to give it any real consideration when it has no support.

How much do you want to bet temps are not a lot lower than what GFS 12z forecast for the 29th?

You see, it is easy to say something might be right no matter how outlandish just so long as there is no pressure or consequences on being wrong.

It might be 21C in Manchester on the 29th but I wouldn't push it as being plausible.

isn't that partly the point of a model discussion forum? the GFS is a model - and currently it shows a breakdown. Why should there be "consequences" for that? It's worth noting that although the GFS looks too quick and doesn't have any support (at the moment) the met office forecast suggests it will turn milder over the easter weekend. So timings may be incorrect, but outcome not so?

That said, i wouldn't be at all surprised to see everything revised again with the "breakdown" being revised beyond Easter weekend. The UKMO and earlier ECM sent too much energy under the block and i can't see them being completely wrong. The likely result for my neck of the woods is more cold and potentially wet weather - but very limited snow chances.

While wer're discussing models i'd like to bank this GFS chart please

Edited March 22, 2013 by Pharaoh Clutchstraw