Model Output Discussion

[KeegansPerm]

Sorry I stuck this on the wrong page before. Moderating guys your welcome to delete.

I know you can't take GFS at face value, but this pattern fits well with the other output I've seen over the last day or two.

If we could get the infromation from ECMWF and UKMO to derive LI and CAPE, I'd expect similar values on Sunday and Monday. Tuesday perhaps slightly more in doubt.

Sunday:

LI and CAPE higher than that today which managed to produce several thunderstorms across East Anglia.

Although may take some forcing, you would fancy sea breeze convergence lines along the North Sea to trigger a few beauties.

Monday:

This could be something special. MSC's perhaps even home grown and not inported from France!

Could be some strong downbursts from storms in this set up ... gusts on the surface of 60-70 KT if not a little more.

Tuesday: Slightly in doubt but if this were to be true everything that Monday has plus a little bit more. Chance of some locally serious weather

[feb1991blizzard]

This must be a BBC wind up, 16c on Tuesday in London, Ok maybe a front will pass through as the ECM suggests but the GFS is going for 28c and with downplaying the temps that's 31c - a 17c difference of opinion!

Not really Alex, the 12z Fax is showing the cold front passing through on monday, now that doesnt mean that there will be a significant cool down for the SE on monday but it could well do by tuesday, it will be interesting to see the latest FAX when it comes out at half 10.

[damianslaw]

A significant warm up from Saturday onwards thanks to a warm front moving NE across the country pulling in some very warm uppers. It does look a classic NW-SE split though - with the NW seeing low 20 maxes at best on Sunday whilst the SE sees high 20's, the heat then remaining in situ over the SE with low 30's a distinct possibility (32 probably absolute maximum and reserved for London), but the NW will quickly see temps returning to high teens Tuesday as the atlantic moves in with associated cold front.

Next week doesn't look particularly settled - the heat will trigger some very hefty thundery downpours in southern and eastern parts early next week and by Wednesday much cooler showery air will move across the whole country behind a cold front, thereafter westerly/southwesterly airstream looks the order of the day - whilst by no means a washout it isn't the high pressure cell many of us are craving at the moment. Southerly plumes very rarely preceed a lengthy settled spell, in most cases they are followed by atlantic assaults.

[A.J]

Has anyone seen the predicted dewpoints for Tues morning across E Anglia/SE.

http://www.wetterzen...s/Rmgfs1178.gif

Surely the GFS is having a laugh.

If it is Dave, it's having a long laugh...it's lasted since yesterday as those dew points first appeared on yesterdays 06zGFS, I posted them in the convective thread along with the obscene CAPE/Bouyancy charts, they were certainly jaw dropping!!

[SP1986]

The dewpoints are only relative though, and if it's 31C with 19C dewpoint it wont feel very humid, whereas 22C with 19C dewpoints would feel very humid. (relative humidity of course)

[Alex]

The 10day netweather viewer says temps will feel like 37c in Chelmsford Essex on Tuesday! I think that's the highest I've seen it on this site! I wonder what 10/08/03 would of shown 3 days before??

[Geordiesnow]

Well tonights 12z ECM has backed down from its 0z with a uk block at t+240 so other than a couple of lovely days for the south east, the pattern remains atlantic dominated with further spells of rain the further north and west you are.

I must admit the models are not really predicting the warm air to reach Northern Ireland for all that long at this moment in time but your post is very mis-leading and quite frankly a bit daft to be honest. I say that because you are starting believeing every run up to 240 hours simply because its showing not what you want too see, I think some on here are long rang forecasters and think they can predict up to 240 accurately simply by reading pressure charts but we all should know predicting the outlook is not a stright forward thing as GP will certainly tell you regarding the NW summer forecast!

Also Conor's comment the ECM is moving towards the UKMO, I'm not quite sure how seeing as the ECM has the main fun and games over us whilst the UKMO has it well to the East, infact the ECM is more or less similar to the GFS but its still sticking to its gun of trying to intensify the low quicker than the GFS does. Perhaps Conor could tell us how in his own eyes the ECM looks more closer to the UKMO, the only difference I see is that the low is predicted slightly further East than this morning's run?

[PubliusEnigma]

This must be a BBC wind up, 16c on Tuesday in London, Ok maybe a front will pass through as the ECM suggests but the GFS is going for 28c and with downplaying the temps that's 31c - a 17c difference of opinion!

I feel some peoples expectations are way above the reality.. If the front has cleared it will be around 18oC on tues.. If its tipping it down under

the front, it will aslo be 18-19oC give or take. This is the most likely scenario..

[Geordiesnow]

I feel some peoples expectations are way above the reality.. If the front has cleared it will be around 18oC on tues.. If its tipping it down under

the front, it will aslo be 18-19oC give or take. This is the most likely scenario..

I would more or less agree with this if the UKMO charts came off as it moves the warmer air much quicker than the other 2 models but I don't know why people are getting so hung up regarding the details. It will change between now and Tuesday but whether that will be for better or worse, depending on your preference is up in the air at the moment.

If the UKMO was showing what the GFS/ECM are showing, I suspect the temperature would be alot higher but thats the fine margins regarding this set up.

[Backtrack]

I feel some peoples expectations are way above the reality.. If the front has cleared it will be around 18oC on tues.. If its tipping it down under

the front, it will aslo be 18-19oC give or take. This is the most likely scenario..

Huh?

Do you work for the BBC? Check the GFS and the local Net Weather forecast. Both agree it will be 27-28c.

You either work for the BBC or the daily mail. :lol:

Edited June 23, 2011 by Backtrack

[chapmanslade]

What i dont understand is we are predicting high temps,strong storm possibilties, but why do we not see these forecast on the telly,or meto web site. Apologises for probably a dumb question.

Not a dumb question at all. I'm afraid the usual hype developing for a potentially convective spell that is out of proportion the the likely event which will be followed by much wailing and gnashing when nothing happens.

Yes CAPE values are high but that is NOT all you need for a guaranteed armageddon style storm. All sorts of spoilers in the mix as usual such as overspill from French MCS storms killing diurnal heating, no forcing to initiate convection etc etc.

There may be some good storms but please retain an element of realism. If you want to see some action go over to France for the weekend where things are much more likely. I'm pleased I missed last years one decent plume event as I was in France, and instead of a few hours of thunder we had a 12 hour back building MCS.

[PubliusEnigma]

WHAT?!

Do you work for the BBC? Check the GFS and the local Net Weather forecast. Both agree it will be 27-28c.

You either work for the BBC or the daily mail. Either way I think you should stop posting rubbish that isn't true.

Fax chart is often deemed as the most reliable.

Notice two things.

1. On Monday, a cold front is sweeping SE accross the UK, ushering in MUCH cooler weather

2. The thundery trough has moved east and is lying in the southern North Sea.

So unless you live on a bouy in the middle of the north sea, and assuming the front doesnt take 24 hours to move a 150-200

miles then I on the basis of the most reliable output, I would say 28oC is highly unlikely on Tues, based on the output

alone..

[Backtrack]

Fax chart is often deemed as the most reliable.

Notice two things.

1. On Monday, a cold front is sweeping SE accross the UK, ushering in MUCH cooler weather

2. The thundery trough has moved east and is lying in the southern North Sea.

So unless you live on a bouy in the middle of the north sea, and assuming the front doesnt take 24 hours to move a 150-200

miles then I on the basis of the most reliable output, I would say 28oC is highly unlikely on Tues, based on the output

alone..

I guess, but this is GFS and ECM vs the Met Office IMO.

Your opinion must be that the Met O will be correct, mine is the ECM and GFS

[PubliusEnigma]

I'm afraid the usual hype developing for a potentially convective spell that is out of proportion the the likely event which will be followed by much wailing and gnashing when nothing happens.

[chapmanslade]

I guess, but this is GFS and ECM vs the Met Office IMO.

Your opinion must be that the Met O will be correct, mine is the ECM and GFS

Because you want it to or do you have sound reasoning ?

[PubliusEnigma]

I guess, but this is GFS and ECM vs the Met Office IMO.

Your opinion must be that the Met O will be correct, mine is the ECM and GFS

I think if you held a vote here, the general concencus would be the fax charts are up

there as the most reliable.

[Harry]

Fax chart is often deemed as the most reliable.

Notice two things.

1. On Monday, a cold front is sweeping SE accross the UK, ushering in MUCH cooler weather

2. The thundery trough has moved east and is lying in the southern North Sea.

So unless you live on a bouy in the middle of the north sea, and assuming the front doesnt take 24 hours to move a 150-200

miles then I on the basis of the most reliable output, I would say 28oC is highly unlikely on Tues, based on the output

alone..

I think that chart is yet to update...the others have updated recently, the FAX is one of the last to do so.

Based on the other models, I would hope to see the CF delayed slightly.

[Backtrack]

Because you want it to or do you have sound reasoning ?

Both.

Yes the Met Office are probably the most popular because it is official, but it's not very often I see the UKMO been on its own.

The major models - GFS and ECM are against it, and in Winter I usually take those two over the UKMO. I just simply think they are more accurate, also the UKMO charts are hand drawn, I think there is a larger margin for error, would you agree?

As much as I like hot and sunny weather, it's based purely on I find the ECM and GFS the best of the three.

[dave48]

That FAX is out of date Harry, you are right.

[chionomaniac]

Fax chart is often deemed as the most reliable.

Notice two things.

1. On Monday, a cold front is sweeping SE accross the UK, ushering in MUCH cooler weather

2. The thundery trough has moved east and is lying in the southern North Sea.

So unless you live on a bouy in the middle of the north sea, and assuming the front doesnt take 24 hours to move a 150-200

miles then I on the basis of the most reliable output, I would say 28oC is highly unlikely on Tues, based on the output

alone..

Are you confusing me again? Why are you using yesterday's FAX chart? Yet again! One could think that this is deliberate!

[chapmanslade]

Both.

Yes the Met Office are probably the most popular because it is official,

I just simply think they are more accurate, also the UKMO charts are hand drawn, I think there is a larger margin for error, would you agree?

Official ? Hand drawn sounds like a quill pen and ink I think you mean charts have a human input to the raw data which sounds like a better idea to me.

Comparing models is immensly complicated and involves a lot of data crunching - a hunch will not do.

[PubliusEnigma]

Are you confusing me again? Why are you using yesterday's FAX chart? Yet again! One could think that this is deliberate!

Its the latest available, for Mon,

The USAF chart also places the front well clear of the uk come Tuesday with a cloudy northerly over the SE.

[anvilhead]

hi all.

could be some strong storms around! looking at the 12z gfs monday night there's surfce se/easterlys over the south uk, underneath a 50 -60 kt jet stream. I'm sure the next run will deal with the loose lp centred over the channel differently, but pretty interesting output right now imo.

Sam

[feb1991blizzard]

Are you confusing me again? Why are you using yesterday's FAX chart? Yet again! One could think that this is deliberate!

The fax charts are updated 4 times a day, that is the most up to date one although the 18z one should be out shortly and presumably takes into consideration the 12z ECM and UKMO.

[chionomaniac]

Its the latest available, for Mon,

The USAF chart also places the front well clear of the uk come Tuesday with a cloudy northerly over the SE.

What front? Misleading nonsense, Stop it.

This chart shows a warm front pushing north, not a cold front pushing east.