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Model output discussion - 5th December 2016 - Into Winter we go


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12 minutes ago, igloo said:

dont be fooled there money making some people believe there accurate some dont they have performed badly this season so far for sure:diablo:

I wonder if things went the other way (long range models predicting mild but weather turned out cold) whether there would be this type of ranting against long range models. It's a science that's improving but it will still get things wrong

Some of the talk in here about LR models reminds me of the Simpsons episode where the residents of Springfield went to destroy the observatory because of an asteroid that was threatening them! Dropping long range models and forecasts won't stop our winters becoming ever more wet and warm and, well, boring.

I'm as frustrated with the lack of winter (yet again) so far as anyone and the models showing pressure builds from the south are really disheartening. It's just all been so boring this last 3 months or so. As a weather enthusiast, it'd be nice to have some weather to talk about (this weekend's gales aside). Our weather seems to have been stuck in 'various types of October' for the last 3 and a bit winters and with high pressure to the south being constantly modelled there is no way out of it in the near future. Ian's update was not promising for cold either.

Still, never mind eh?

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ECMWF Monthly goes off-piste versus it's deterministic brother into & particularly beyond Christmas. The +ve GPH/MSLP anomalies out to our NE merely intensify again towards end of month, then show

My retired colleague Ian McCaskill, RIP, would have relished discussing this Christmas Kerfuffle on-air with typical humour.  GFS 12z deterministic very similar in final reaches of run to Thursda

EC MONTHLY: again like last run. Blocked & dry anomalies developing 1st half Jan as heights move W to north of UK. Colder than avg anomalies southern UK 2nd week Jan (not seen that signal for a wh

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There are many in here attempting to use reverse psychology on the weather. "Oh winter is over..." "Not if I have anything to do with it... here, have some blizzard conditions"...

Run through day by day from 1st Dec 2011 through to Feb 8th - the latter I recall had minus double digit nights, some snow on the ground for a week when I was in Surrey and the river Wey frozen in parts.

http://www.netweather.tv/index.cgi?action=gfs;sess=

Dec 2011 on the whole was similar to now. HP to the south, LP to the north, few windy days, mostly PM, RPM and TM airflow... it took more or less until the end of Jan 2012 for this to change. I'd happily wait 6 more weeks for the chance of a few snow days than a couple of dustings and a few frosty nights.

I'm just hoping for something from the NE for a possible Kent snow streamer. I may have to venture slightly inland as may be too warm here... especially with me being on the seafront itself. @Tamara can empathise with me on that one, although, I think she isn't as close to the sea as I am.

 

Edited by Blake
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37 minutes ago, Ed Stone said:

Well, if the extended range of the GFS shows anything, it's that, at T+384, numerical weather-forecasting models are not yet quite up to the job; they're getting better, yes, but there's still along way to go...

The Law of Diminishing Returns is - I think - very pertinent when applied to computational advances; just because the MetO or NASA (or the Daily Express!:D) can double their computational power doesn't mean that their forecasts' accuracy-time will noticeably increase as a result?

Personally, I think it'll be many years before 15-Day forecasts become properly viable, if they ever do; mathematical chaos might be a bugger to get round, no matter how elaborate the calculator is?

I'm hoping that some of our resident mathematicians might come to my aid, here. I think I need it!:shok::help:

It's not necessarily a computational problem since modern computers can crunch mind boggling quantities of data. I imagine it's more of a data assimilation problem, It's just not possible to record every possible variable in the system.

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19 minutes ago, LRD said:

I wonder if things went the other way (long range models predicting mild but weather turned out cold) whether there would be this type of ranting against long range models. It's a science that's improving but it will still get things wrong

 

How often do models predict warm and it turns out cold ? 

The GFS 18z on 9th dec had -8c uppers over kent yesterday

You can see SM frustration as the snow shovel had been bought.

-8c 850s kent.png

sm practicing.jpg

Edited by stewfox
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6 minutes ago, stewfox said:

How often do models predict warm and it turns out cold ? 

The GFS 18z on 9th dec had -8c uppers over kent yesterday

You can see SM frustration as the snow shovel had been bought.

-8c 850s kent.png

 

 

sm practicing.jpg

:D

I can tell you when the models predict warm and it turns out cold - the summer :(

Although wasn't a mild winter predicted in 2009? 2009-10 was a cold one.

Sorry mods - barely on topic. I'll shut up now

Edited by LRD
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2 hours ago, fergieweather said:

Well, very low confidence...!! As expected.

We will see whether ECMWF Monthly this evening keeps banging the blocked drum, or switches and offers the much more mixed signals of GloSea5 (slowly progressive, some blocking, but ensembles unconvincing re ultimate outcome). Dominant signal for remainder of winter (albeit as previously discussed, a divergence in ECMWF & GloSea5 output) is for broadly +ve avg temps (some colder phases possible); +ve NAO (mostly, with possible exception part of Jan) and SPV remaining stronger now. Broad GloSea5 pattern ultimately favours high pressure to S of UK, helping perhaps to keep things drier overall but there's equal probabilistic weighting on +ve/-ve PPN anomalies. December Contingency Planners doc offers further context.

 

THankyou again for your input Ian. The way I see it we unless the ecmwf monthly backs glosea5 tonight we will have the two best lrf tools in the world going in somewhat different directions , yet presumably from very similar initial data. I think what people need to understand is that both of these systems are still to a certain extent experimental  and this is perhaps not made enough of when the the likes of John Hammond do their presentations on the BBC website.. There is no doubt now that the December part of the forecast is completely blown. Yes some may argue that there was blocking but when you go out of your way to say that the blocking will be in a position to bring more easterly or northerly outbreaks with an increased risk of ice and snow and in fact the blocking brings you a mild Dec running some 2.c above normal then  one has to see it for what it is. This is not to attack he Meto office or Ian or John Hammond in any way because I have the utmost respect for the organisation and those that work in it .THe meto and ecmwf are least trying to push the science forward. But just to say that we are nowhere near where we need to be yet to make consistently accurate seasonal forecasts..

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The anomalies tonight are all agreeing on a pattern change albeit not in uniform agreement as to the precise details, All agree on a reorganization of the Greenland/Canadian vortex and the retrogression of the Atlantic trough but continue to disagree on it's orientation and intensity. This in turn effects the upper flow and the orientation of the positive anomalies and the ridging adjacent to the UK. As can be seen the ecm has a deep lying neutral trough which backs the upper flow south west with the HP more influential. Ergo more amplified.

So essentially this means that the systems being generated upstream and tracking E/NE on the jet are more liable to curve north with the ecm and more settled weather encroaching further north than the other two. With it must be added, temps a little above normal.

610day.03.gifecm_eps_z500a_5d_nh_11.pnggefs_z500a_5d_nh_41.png

The 10-15 period sees a consolidation of the retrogression theme with the vortex becoming more organised over N. Canada and a zonal flow across North America. Disagreement still exists vis the trough in the western Atlantic and the ridging adjacent to the UK which again effects the amplification and again the EPS is the bolder of the trio. Bottom line is we could be looking at period of more settled weather after the Xmas hiatus with the Azores being the main player. Temps on the whole not too bad but not much point in looking at that this far down the line

814day.03.gifgefs_z500a_5d_nh_59.png

 

 

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8 minutes ago, Summer Sun said:

Tonights ECM ens supports the idea of high-pressure returning next week

ECMAVGEU12_168_1.pngECMAVGEU12_192_1.pngECMAVGEU12_216_1.pngECMAVGEU12_240_1.png

Christmas day doesn't look too bad on the ens unsettled but nothing major

ECMAVGEU12_144_1.png

Thanks. Looking at that, I am struggling to contain my excitement and heart rate at the sheer boredom of it all

Utterly awful. Amongst the very worst of a really bad bunch of runs from the models of late

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Far from writing off this winter, I see us being a just over a week ahead of schedule on the way to what will be remembered as a wonderful winter....

Slugs can frustrate surviving through to the end of a year but it can be great when they die during January 

Rslp19461229.gif h500slp.png

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Yes, the model output is dire for those of use wanting the cold weather. Looking the present and forward modelling and Fergies comments maybe it was a front loaded winter afterall. The end of Nov and early Dec are perhaps as good as it gets. So close to something akin to 2009 / 2010. 

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You guys wont want to look at Summer Sun's latest post in the Meto contingency planners thread

Dire for cold for rest of Winter. Probability of colder temps reduced.

Winter 16/17 - already ticked off as likely to be rubbish for cold and snow

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7 minutes ago, Cleeve Hill said:

The end of Nov and early Dec are perhaps as good as it gets. So close to something akin to 2009 / 2010. 

 we still have Jan and Feb to look forward to..:santa-emoji:

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Just now, swilliam said:

Wow - on the basis of a long range forecast for several weeks of 'above average temperatures being slightly more likely than below average temperatures'  you are going to write of the whole the winter for any cold and snow - amazing.

Yep, because those predictions are generally spot on.

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5 minutes ago, swilliam said:

Wow - on the basis of a long range forecast for several weeks of 'above average temperatures being slightly more likely than below average temperatures'  you are going to write of the whole the winter for any cold and snow - amazing.

Yep. We're in '70s Winters' territory. 09/10 and 10/11 were just 'blips' in an otherwise 20 year run of mild UK winters.

Edited by Bristle boy
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Models all showing a resurgent atlantic, after a very long period of lacklustre strength, unusually long it has to be said, and it was only a matter of time it broke back, pity its just in time for christmas.. gales forecast, so the first proper windy spell of the winter. Hoping it won't be too windy, 1997, 1998 and 2013 were exceptionally wet windy christmas periods.

General theme is for a predominantly south west/westerly flow for the foreseeable bringing above average temperatures, though some brief polar maritime incursions will bring temps down closer to average in the north at times, and snow for high ground, perhaps modest levels at times with some patchy frost, so at least in the north feeling a bit more seasonal than recently. It is all very normal for the time of year, this is notorious for being an atlantic stormy period. Indeed, this will be the sixth wet windy mild atlantic dominated latter part to December in a row. 

Suspect this thread will turn into a frustrating one over the next few days, with the models showing continued similiar fayre. I'll be dipping in and out, and hoping the New Year brings something a bit different with a trend to colder good walking weather.

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2 minutes ago, Frosty. said:

 we still have Jan and Feb to look forward to..:santa-emoji:

One can only admire your optimism Karl, doesn't look too encouraging from next Tuesday on however with Ecm Ens now on the same hymn sheet as the op with regards to the slug taking centre stage again.:nonono:

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