Model Output Discussion; into 2015

[Jason M]

The GFS is known to have a bias towards continuing any tropical convection into phases 7/8. I can't sem to get the link to work currently but the bias corrected NCPB ensembles normally autocorrect the NCPE. If someone can put these up I'd be grateful.

Here you go

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=384&code=0&mode=0&carte=0&bc=1

To access via meteociel just go to the GEFS and you can get them from there.

[nick sussex]

Here you go

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=384&code=0&mode=0&carte=0&bc=1

To access via meteociel just go to the GEFS and you can get them from there.

I think Chiono is looking for the MJO one Jason, typically that page has gone blank, some of the others are there and its clear theres disagreement:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

 

NCPB and NCPE nowhere to be seen , perhaps they're in the process of updating. The MJO update I posted earlier suggests NOAA are confident of a strong MJO signal for two weeks from the date of that update which was 29th December.

Edited January 3, 2015 by nick sussex

[snowking]

The GFS is known to have a bias towards continuing any tropical convection into phases 7/8. I can't sem to get the link to work currently but the bias corrected NCPB ensembles normally autocorrect the NCPE. If someone can put these up I'd be grateful.

Unfortunately all the GEFS images on the CPC site are blank today.

Last update I saw (Thursday) had the raw output headed in to phase 7, but I did not get a chance to peruse the BC output

SK

[Frosty.]

GEFS 12z control run turns into an EPIC for cold lovers, stunning charts with the UK going into the freezer, and staying that way for some time :- )

[Harsh Climate]

I'm liking the ECM 12z 

 

IMBY not far off -6 uppers for 3 days at the end of the run!

 

 

 

Edited January 3, 2015 by Harsh Climate

[Tamara]

You say it's GFS v the rest but the period of interest/possible change doesn't happen until around 276H

 

GFS

 

GFS parallel

 

.

 

That is out of the range of ECM/UKMO/JMA/GEM amongst others. Also I'm not too sure on the accuracy of MJO induced forecasts but I can't see it being the be all and end allof what will happen.

 

Hopefully though the ECM 12z may just be getting into the range were we can see if it agrees with the GFS so could be quite interesting the last couple of frames. Yes FI but we have to start somewhere after such a dire few days of output. : )

 

Indications of the MJO bailing out on approach to Phase 7 are a solid sign of -ve Atmospheric angular momentum which roots tropical convection right back to the Indian Ocean and the Western Pacific. Lack of further progression means we lose the opportunity to get an especially amplified pattern in the Atlantic that can be sustained and cause maxiumum damage to the Polar Vortex over Canada and Greenland.

 

Furthermore, failure to engage Phases 7/8/1 and instead a dying MJO wave and retreat back to Phases 3 to 5 signify a flattening out of the pattern and re-assert the Azores High. Which is clearly what we don't want to see keep repeating!

 

The fact that most modelling is less bullish about MJO progression tells us that most are in favour of -AAM state continuing which will inhibit MJO eastward progress. This makes complete sense to me.

 

This MJO  'bail-out' is exactly what happened in December and the present MJO forecasts (apart from the GEFS) indicate a similar cycle through January as -AAM persists. Yes, forecasts can change and the same thing might not happen again in January - but we should caution because as I posted earlier, and have been rather banging on about for some time now, -AAM cycles tend to repeat - and lock in the dominant background seasonal pattern.

 

The implications of a Nina-esque AAM in winter support a pattern which props up sub tropical ridges to mid latitudes (e.g Azores high and associated +NAO) and also mitigates wave activity and poleward EP flux - despite an -QBO and seemingly in spite of significant SAI and SCE feedbacks from the autumn.

 

Does this Azores ridging and +NAO all sound rather familiar from the modelling?

 

Much of the expectation this season has been that there would be some coupling of the atmospheric pattern with the weak ocean El Nino signal (which would support a more meridional pattern and teleconnect to anticipated -AO feedbacks) The MJO forcing would overwrite the pattern if it proceeded into and beyond Phase 7 at a decent amplitude

 

Clearly, this has not happened so far - and underpins the METO expectations for a +NAO signature through to at least the first half of the winter. Uncertainty prevails from now on as to how this pattern might change - but through the reasoning given here, and on occasions previously, there is a lot of evidence to suggest that this cycle might not break easily till the later part of the winter.

 

That is not a definitive prediction and much can happen in the coming weeks - but it is a realistic assessment of how things have not gone to plan (for snow and cold lovers) and why trying to evolve to any -NAO regime might be quite tricky during the heart of winter

 

So I fully, although obviously reluctantly, support the sensible caution suggested by snowking regarding FI charts in light of the overall consensus of the MJO forecasts, which are underpinned as explained.

 

I apologise for continual repetition and boring everyone rigid about Nina atmospheric states !

[Frosty.]

GEFS 12z mean continues to trend colder through FI, as it has done in recent days.

[Mucka]

I'm liking the ECM 12z 

 

IMBY not far off -6 uppers for 3 days at the end of the run!

 

 

 

 

 

Not quite. There will be a warm sector push through which will negate any snow chances for a chunk of that period which is easily missed because of the 24h steps.

It is another step toward a colder zonal pattern setting up later next week with snow chances, more especially int he North, though.

I still feel a heavy snowfall is possible somewhere in the run up to mid month although it is not likely to stick around.

[Liam J]

A very disturbed ECM run this evening from mid-week onwards. Gales/severe gales at times, very volatile and fluid situation looks like taking hold next week where potential windstorm developments could occur with relatively short lead times. 

 

http://www.meteociel.fr/modeles/ecmwf.php

[gottolovethisweather]

GEFS 12z control run turns into an EPIC for cold lovers, stunning charts with the UK going into the freezer, and staying that way for some time :- )

 

Not sure what is so EPIC about that chart Frosty but folk shouldn't also take their eyes off the here and now as tomorrow is forecast to witness Maximum Temperatures of 1c to 2c in some parts of the UK, more especially in the fog bound Midlands, just out of curiousity. Although I don't see much entertainment for coldies this side of next weekend at the earliest, the low pressure system signalled for the period from 8th through to 10th January will be one to watch, given that its track and intensity is unknown at this range. It may become another of my game-changing low pressure sytems should it exit the NH Jet at a favourable angle and dive into Europe, all conjecture currently and at the realms of early FI anyhow.

 

For now, the more usual setup of late continues.

 

https://forum.netweather.tv/topic/81813-southwest-and-central-southern-england-weather-chat/?p=3105688

Edited January 3, 2015 by gottolovethisweather

[lorenzo]

Some more MJO things, courtesy of Roundy, Adrian Matthews , Mike Ventrice.

 

Looks like the CPC material is offline for GFS perhaps in transition to Parallel and being tweaked around.

 

On balance Phase 6 looks good, Phase 7 and 8 a push, as with last cycle.

 

First phases - 

 

ECM Ens via WSI - 6 approaching 7, notice the speed of decay

 

Matthews 6 and circle of doom

 

Mike Ventrice RMM Plot - phase 6

 

Roundy Hovmoller - MJO is solid red lobe pushing to 180 - 6 then unclear

 

Composites - can't see Alan Huffmans original Jan ones only the Nino adjusted, these are not weighted for Nino / Nina - only amplitude.

 

Phase 6 

 

Phase 7

 

So Phase 6 as the sensible projection for where we are heading, should the MJO imprint. A delicate balance here between what the vortex does by way of splitting and reformation, versus can the more blocked outlook of MJO deliver at the precise time where we have the vortex leaning from one side of the hemisphere to the other. i.e will the tendency to block be cancelled out by a vortex re-establishing over Greenland / Canada side, or will the burn out at 10hPa be enough to drain energy to the Russian side and in tandem the MJO blocking doubles up and takes advantage of vortex weakness.

 

Too difficult to work out, this season my money would be on the vortex mid month, but we shall see. Latest Solar Flux projection shows a peak approaching the solar max of Cycle 23 mid month at 180, huge double spike against the trendline. If this is said to assist the vortex then we need that strong MJO to deliver and deliver well.

 

 

Edited January 3, 2015 by lorenzo

[nick sussex]

Until this MJO discrepancy exists then what happens from mid month is up in the air.

 

Personally I find little to get excited about if the sum total of the patience being shown by members in here is  three hours of slush and the BBC sticking a reporter on some high level cross Pennine route exclaiming that the country is gripped by some snowfest!

 

For this reason we have to hope that the MJO manages to not hit the buffers before reaching phase 7 and 8, although this won't guarantee sledges given the winter so far it might at least deliver sufficient amplification and give a better chance that some proper Arctic air can blast through the current UK defences!

[Woollymummy]

This is a great new way to fritter away the remains of your holiday: I just did. Sort of like top trumps for weather:

http://www.ready.noaa.gov/READYcmet.php

I only chose Helsinki as the target city as it is the nearest in line to northern parts of UK who looked lined up to get the next incoming gale.

Edited January 3, 2015 by Woollymummy

[J10]

Given weeks (or months) of testing, have they started off comparing the GFS to GFS(P) to see if the new parallel is more accurate to the (old) GFS.

[IDO]

My own thoughts on the changes around D12 is that it is like Tamara mentions, a repeat of what we had just after Christmas. That was a direct result of a couple of blocks of heights moving east from the US and reacting with the Azores. We got some amplification, that promised an Atlantic ridge and was eventually a toppler.

 

This time the heights exiting the US look to be even stronger, ECM says 1060mb (probably over egged). That will be ejected from the US around D10:

 

 

 

These will around D12 bang up against the Azores: 

 

The Azores has no where to go so will either support those heights (Greenland ridge) or the Azores will be forced east, and maybe build a MLH. The hi-res going the Greenland route suggests at the moment that is what the GFS is seeing (MJO forcing leading that?). However at the same time we have a split jet with a mish-mash of upper lower heights which could create short wave spoilers on the northern arm of the jet or alternatively develop an upper level low to further support any heights:

 

 

So I am not sure it is a MJO signal, just the normal progression of a strong mobile high; it has to go somewhere! Can that force mid-lat disruption like an ex-tropical storm, I think it can, but whether it will is another matter. Looks quite complex and if we get the MJO going favourable at the same time, well that can only aid the pattern. enhancing the longevity of the Atlantic ridge.

[fergieweather]

Given weeks (or months) of testing, have they started off comparing the GFS to GFS(P) to see if the new parallel is more accurate to the (old) GFS.

We'll miss the old one's flights of fancy into Neverland timeframes when it's gone, but maybe the new one can pick up that mantle... ;-)

[mountain shadow]

We'll miss the old one's flights of fancy into Neverland timeframes when it's gone, but maybe the new one can pick up that mantle... ;-)

At least its products are free unlike the Uk met and ECM which our taxes pay for.

You can only work with what you have.

[nick sussex]

We'll miss the old one's flights of fancy into Neverland timeframes when it's gone, but maybe the new one can pick up that mantle... ;-)

You shouldn't have to wait long! Strangely the GFS last winter and this one so far has been a bit more reluctant to throw out over the top cold scenarios. It used to be with four runs a day you were always guaranteed something to keep this thread interested. It's a shame the ECM doesn't do four runs a day,that would certainly keep the model anoraks amongst us happy!

[Frosty.]

Tonight's Ecm 12z op run shows milder tropical maritime & cooler north atlantic air trading blows until around days 7-10 which are predominantly cold with wintry ppn and frosty nights. Comparing like for like, tonight's ecm run is light years better than last night in terms of colder potential and actually better than the 00z, a few days show 522 dam covering parts of the UK. Overall I think we are heading in the right direction..a cold direction..a good direction :- )

Edited January 3, 2015 by Frosty.

[Mark Bayley]

Unfortunately all the GEFS images on the CPC site are blank today.

Last update I saw (Thursday) had the raw output headed in to phase 7, but I did not get a chance to peruse the BC output

SK

 

From what i remember the BC output was less enthusiastic about progression to phase 7 (made it through to 6 before seeming to die)

 

Edit: * yesterdays MJO forecast

Edited January 3, 2015 by Mark Bayley

[nick sussex]

At least its products are free unlike the Uk met and ECM which our taxes pay for.

You can only work with what you have.

Blame the government, if they gave enough funds to the UKMO it wouldn't have to rely on the commercial side of things. I'm surprised they haven't sold off the UKMO to the Chinese, they've sold everything else off!

[Frosty.]

Blame the government, if they gave enough funds to the UKMO it wouldn't have to rely on the commercial side of things. I'm surprised they haven't sold off the UKMO to the Chinese, they've sold everything else off!

LOL Nick and what do you think of tonight's 12z? A little happier than last night I would think?

[Barry12]

The UKMO should go to day 10, just going to day 6 is poor!

[Captain Shortwave]

The UKMO should go to day 10, just going to day 6 is poor!

Given how the output tends to fall off a cliff in terms of reliability after 6 days then maybe the model has the right length to it. Though if we could see the mysterious T168 charts then that might be an added bonus.

[bluearmy]

The UKMO should go to day 10, just going to day 6 is poor!

 

jeez - i couldnt cope with you lot and another 10 day op !!  given the verification stats, i'm surprised that the indian model doesn't get more press on here.