12z model discussion - snow or sleety rain?

[Thundery wintry showers]

i was being frivolous.... yes id like a decent dumping, but im far from convinced that this 1 chart will be the actual one that transpires.

I agree; I have my doubts about the UKMO, particularly as it seems to be the run going for the longest-lasting cold spell so far, at least for central and northern regions.

I also agree with the posts saying that the UKMO has been the most consistent of the models recently- consistently prolonging the cold wintry weather through until at least Friday, but the question is, has it picked out a new trend (the southerly tracking low and easterly winds for the weekend) that the other models will follow, or is it a one-off? I have a suspicion that it may be the latter, though in any case the GFS has moved away from its progressive solution this morning.

[Harsh Climate]

I might get put in a straight Jacket for this but I think generally the GFS is the best model! I know you can get some wild runs thrown in every known n again but if you can pick a trend up in those runs its usually right.

I think the ECMWF has been very poor this winter, the JMA has suprised me a little and certainly worth looking at in the future (prior to these type set-ups) and at close range the UKMO is a very good indicator of what you might get..

[wellington boot]

Back the form horse or the model thats showed the most consistency which has been the ukmo over the last few days, the reason for so much trauma in here is the over reliance on the gfs which throws up four runs a day and sends people hurtling towards the prozac cabinet far too often.

This is a common gripe of mine that this model thread ends up being the gfs discussion thread and the other models are often cast aside. The gfs is not fallible as we've all seen over the last few days, anyway lets hope the ecm keeps the upbeat mood going.

Yes good post. Its true, there is definately an overreliance on gfs. I should add that in my experience, the gfs is actually strangely weak when it comes to close range forecasting. It can be incredible for the trends, and solid out at 144 or thereabouts, but, and particularly in the less common/cold situations, it can go off the rails at close range, and totally move away from what its forecasted before. Its done it before, and it has done it this time, certainly with the 00z and the 6z.

[johnholmes]

how on earth can

Isn't the UKMO chart the least accurate normally? Or does that change seeing as it's showing a good snowy spell of weather?

you believe that?

Aside from my obvious belief in ex colleagues ability. How can a man/model interface not be better than a model on its own?

And that relates to any time scale.

[wellington boot]

you might well PREFER more the likelyhood of getting it in my view is zilch.

Yes i am aware of this! I just want to be spoilt!

[Harsh Climate]

how on earth can

Isn't the UKMO chart the least accurate normally? Or does that change seeing as it's showing a good snowy spell of weather?

you believe that?

Aside from my obvious belief in ex colleagues ability. How can a man/model interface not be better than a model on its own?

And that relates to any time scale.

what if the man/model interface is EvertonFox/NOGAPS?

[johnholmes]

I might get put in a straight Jacket for this but I think generally the GFS is the best model! I know you can get some wild runs thrown in every known n again but if you can pick a trend up in those runs its usually right.

I think the ECMWF has been very poor this winter, the JMA has suprised me a little and certainly worth looking at in the future (prior to these type set-ups) and at close range the UKMO is a very good indicator of what you might get..

you really should read the objective posts from TWS not your own subjective memory of how things were or are.

I think you will find if you look at the posts from TWS that through the winter there is not a lot to choose between them at the time scale he is checking.

[wellington boot]

The UKMO has been the star model this winter and if you have noticed the Met O have stuck with the raw data quiet often this winter despite the ECM having other ideas.Im not just saying this because of tonights output because i've been saying before the cold spell.

yes that's the problem with supporting the ukmo at this point. It looks like your ramping. In fact i was talking a week or two ago about my support for the ukmo as overall best model, so i have the right to support it now

[grab my graupel]

i was being frivolous.... yes id like a decent dumping, but im far from convinced that this 1 chart will be the actual one that transpires.

I'm with you on this Mushy.

That's why I have decided to sit on the fence a little bit with this one.

I think that if the professionals can't decide what is going to happen then there isn't

much hope for the rest of us, given how delicately balanced the situation is a the moment.

I think these wonder charts that are thrown out from time to time don't help the situation,

and add to the overall dissapointment.

It is ashame all the major models don't come out at the same time, then that way

we could compare them in a more sensible and relaxed fashion, instead of having hours

of ramping/gloom before the next model run comes out.

Having said that I can understand the excitement, but Ive been involved long enough now

to be a little more patient than I might of been a while ago.

I feel sorry for John trying to keep his blog up to date at the moment.

I bet the poor man can't sleep at night.

Brian.

[johnholmes]

I think I'll have another blog tonight and do it from Wed evening to Saturday morning ONLY.

I have no idea at the minute what it will show but rest assured I will attempt to be objective and give an honest idea of how it looks.

[Optimus Prime]

Aside from my obvious belief in ex colleagues ability. How can a man/model interface not be better than a model on its own?

And that relates to any time scale.

That's what I was thinking but in the recent past a lot of people tend to side that UKMO model shows the mildest possible solution and is just generally more inaccurate in comparison to the GFS.

Personally my favourite is the ECM, it's been a little less consistant compared to the GFS but is normally a very trustful model.

I don't rate the UKMO as highly but is at about the same level as GFS. Joint 2nd out of them all.

[The PIT]

how on earth can

Isn't the UKMO chart the least accurate normally? Or does that change seeing as it's showing a good snowy spell of weather?

you believe that?

Aside from my obvious belief in ex colleagues ability. How can a man/model interface not be better than a model on its own?

And that relates to any time scale.

Ach John you've noticed this. Model swapping until they find one that suits which suddenly becomes the defacto standard. Irratates me as well. Looking at the TWS model comparison the big three are very close together with very little to choose between them.

[Thundery wintry showers]

Personally I tend to think of UKMO as being weaker than GFS and ECM at T+144, but every bit as good as them at T+120 and T+96. Although it isn't a hard and fast rule, it's often the case that UKMO drops marks in my analysis because of poor T+144 outputs.

[mcweather]

Have to back nick up on that as well. Interesting to note here in the south as well that the local radio although still mentioning uncertainty is talking much more snow and much less about poss rain later in the week this evening. Both the fax andf the ukmo go for a longer lasting scenario at the moment. They are the form horse and the development they show is classic as wellas reasonable. The fact that we have not seen a development like it for a very long time does not invalidate it.

[kold weather]

ECM is according to NOAA the most accurate in the N.hemisphere, however the problem with this is that our part of the world is one that can be affected by so many major factors and for this reason probably locally the models aren't so good as thier global verification scores promote they are.

This set-up is certainly going to be hard to predict. I remember the last cold spell a couple of weeks ago the GFS picked up something that the faxes didn't however equally the system that pilled thorugh England was picked up far better by the UKMO, tohugh eventually it was too far west. The GFS is a good model however it has rather bad problems with how deep it makes Lp's and it has biases on it that the others don't have quite so badly, these biases strech back to about 2001-02 when the big guns in the states saw that the GFS pumped out tropical cyclones WAY too often which obviously screwed up FI. since then they've changed the code i believe which has solved that problem but as a side effect the GFS is often a little too cold past 72hrs (yep...how many times have we seen GFS downgrade cold!!!!) and so has to be treated carefully in times of global transition, when the planetary set-up is stable its a very very good model however maybe one of the best.

Ian, its quite funny, it does strike me though as quite a classic set-up, i wonder when the last time we had a set-up like this, came close in Mar 2006 but this looks even closer.

Edited February 5, 2007 by kold weather

[nick sussex]

yes that's the problem with supporting the ukmo at this point. It looks like your ramping. In fact i was talking a week or two ago about my support for the ukmo as overall best model, so i have the right to support it now

IMO the ukmo 96hrs raw data is the one I would most trust and its less likely to go AWOL, as John H mentioned though you can't beat the fax charts as they have that human input thats been garnered over years of experience at dealing with similar synoptics. I would never back the gfs upto 96hrs against the ukmo fax charts .

[Anti-Mild]

I must admit I do not rate the UKMO that much! My favourite model is the ECM with the GFS scoring highly because of its accessibility.

For me the UKMO is often 'out of left field' with some of the charts it churns out.

Of course I'll be backing it to the hilt until this weekend !!

[wellington boot]

This set-up is certainly going to be hard to predict. I remember the last cold spell a couple of weeks ago the GFS picked up something that the faxes didn't however equally the system that pilled thorugh England was picked up far better by the UKMO, tohugh eventually it was too far west.

Problem with the gfs, is that with four outputs per day, and all with different data inputs, it picks up every possible outcome at some point along the line. identifying the trends, and working out which charts are the right ones to discard is the hard part.

[Nick F]

Some interesting updated Faxes:

...first off the t+48 for 12z Weds shows an occlusion around a meso low grazing the South as it moves East which could bring some wintriness:

http://www.wetterzentrale.de/pics/brack1.gif

... then t+60 and +72 charts for 00z and 12z Thursday show the arrival across S'ern UK another low, with the occlusion bringing snow roughly North of the M4 (S Wales, S Midlands and E. Anglia Northwards) during Thursday:

http://www.wetterzentrale.de/pics/brack1a.gif

http://www.wetterzentrale.de/pics/brack2.gif

[Yeti]

Tbh the Gfs is good if you live N of Sheffield, but extremely marginal south of here. I won't mention the UKMO - wouldn't want to ramp!

What I'm really looking forward to is what has the potential, according to many of the models, to be some of the best radar/lamppost watching we have ever seen!

Better get that NW-Extra

Notice even dear old Everton has dared to mention the s word... he was saying significant snowfall for many. Up to 2-5cm in the odd place :o shocking lol

Edited February 5, 2007 by Yeti

[Troubleatmill]

Completely agree with you Brian , i am enjoying watching the models at the moment but am firmly sat on the fence at moment , been here too many times & let down just as everything seemed to be in place , quietly hopeful but like you say more patient now than perhaps i once was.

Edited February 5, 2007 by arron123

[Paul]

Just a quick plug for nw extra folks.

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And then at the online payment page, just call the number on the screen and we'll have you up and running straight away

Plug over!!

[wellington boot]

yes it could be yeti! By the way, when people regularly refer to this place going into meltdown, i think this is the beginning of what is meant. A constant stream of posts. Amazing charts just a couple of days away, with incessant posting of newly found incredible snow charts. A couple more runs showing the same stuff, or better, and this place will fully go into meltdown. Its hectic already, but it could get busier

[The PIT]

Beeb Forecasters playing it very carefuly. Maybe an increased risk of Snow later in the week. The suspense builds.

[Snow Queen one]

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Weather forecast options: 16 day extra detail Snow risk Storm risk Worldwide

Today Tomorrow Wed 07/02 Thu 08/02 Fri 09/02 Sat 10/02

Sun 11/02 Mon 12/02 13/02-15/02 16/02-18/02 19/02-21/02 Help/info

Snow risk Forecast for Maidstone

Thu 08/02

00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00

Ave Temp 3.2°C 3.4°C 4.2°C 6.3°C 8°C 7.4°C 5.4°C 5.2°C

Min Temp 1.8°C 3.2°C 3.3°C 4.3°C 4.3°C 7.4°C 5.4°C 5.2°C

Wind

14.3mph

19.2mph

18mph

20.6mph

16.3mph

11.4mph

8.1mph

11.4mph

Wind Chill 3.2°C 1.6°C 3°C 4.3°C 7.5°C 7.4°C 5.4°C 5.2°C

Humidity 74% 88% 98.5% 91% 79.5% 82% 87.5% 89%

Wet Bulb Temperature 1.8°C 2.8°C 4.1°C 5.9°C 6.9°C 6.5°C 4.7°C 4.7°C

Dewpoint -0.9°C 1.6°C 4°C 5°C 4.7°C 4.6°C 3.5°C 3.6°C

500-1000 hPA 532 dam 534 dam 534 dam 532 dam 531 dam 530 dam 529 dam 529 dam

850-1000 hPa 1294 m 1299 m 1308 m 1316 m 1314 m 1316 m 1315 m 1312 m

Cloud Cover 89.5% 100% 100% 91.5% 66% 67.5% 84% 100%

Precipitation 0 mm

(None) 0.949 mm

(V Light) 5.55 mm

(Heavy) 0.55 mm

(V Light) 0.55 mm

(V Light) 0 mm

(None) 0 mm

(None) 0 mm

(None)

Snow Depth 0 1 4 2 1 0.5 0.5 0.5

Snow Forecast 37%

ht:SL 22%

ht:SL 0%

ht:SL 0%

ht:SL 0%

ht:SL 0%

ht:SL 0%

ht:SL 0%

ht:SL

Updated using the 12Z Run on Monday 5th February 16:46:00 GMT

Just looked at this and i am wondering how accurate this information is. I can't believe we have heavy snow forcast for Maidstone on thurs morning This is the only way i could post the data can anyone confirm how accurate this is?

See mods i tired to plug net weather extra for you. It is good though.

Edited February 5, 2007 by Snow Queen one