Model output discussion - 1st December onwards

[Nouska]

15 minutes ago, Ali1977 said:

FI GFS may be pretty close to reality then, really bad for the skiing industry if this is true.

Well that's a perfect poster for the January composite of the two strongest Nino events - you have to hope that the models are responding to climatology and reality can produce something different. I don't see that chart giving the NW much of a break from rain though?

[Timmytour]

As we come to the end of the 21st December 2015, I believe that's around 100 fewer pages of posts this year than there was last year.

And considering how poor last winter was for so many, that probably tells a story in itself!!

[booferking]

Just for fun i found one on GEFS that delivers the beastly.

[MJO]

The ECMWF monthly control in too good for my country -Israel- at new year's eve 

Edited December 21, 2015 by MJO

[North-Easterly Blast]

Last winter certainly wasn't particularly cold, but it wasn't appalling and brought many areas of the country more in the way of cold spells, frosts and snow than winter 2013-14 did.  So far it looks as though this winter is devoid of anything that can even bring any cold days, a frost or even a wintry shower to most parts of the country.  It just seems as though a strong ENSO event either way just is bad news for UK winters - although even a neutral ENSO doesn't guarantee a decent UK winter at all, just look at 2013-14, 1989-90, Jan / Feb 2002, and winter 1974-75 was also very mild and that was a weak La Nina.

The whole pattern just seems to be totally against the UK, Euro High unable to build far enough north to get the UK cold, no trough disruption at all.

[Jason M]

Impressive easterly there booferking! I raise you the chart below

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=18&ech=372&mode=1&carte=0

 

Not every day you see -18C at 850 over the SE!!

 

[booferking]

5 minutes ago, Jason M said:

Impressive easterly there booferking! I raise you the chart below

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=18&ech=372&mode=1&carte=0

 

Not every day you see -18C at 850 over the SE!!

 

Holy moly

[SMU]

20 minutes ago, Jason M said:

Impressive easterly there booferking! I raise you the chart below

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=18&ech=372&mode=1&carte=0

 

Not every day you see -18C at 850 over the SE!!

 

Impressive as the T2ms are -8c for the SE !!!

 

another day... Nothings changed since last night.....

 

s

[Jason M]

 

Yep, not gonna happen but combined with warm SST's that would be an absolute snowmaker. A once in 200 year event, with several unscheduled bank holiday's 

 

 

[Duane S.]

This could get interesting... Member 18 is obviously extreme and highly unlikely but... it is not without foundation. It will likely pivot around just how far towards the Arctic the WAA can reach. I think there will be a tipping point here.

Most still have it getting around Northern Norway, this will most likely be flattened out and we we return to type. If though (BIG if) we can get it piling right up into the Arctic itself then it is potentially game on. 

This is what we're looking for and has support. Something like this may well be a big outside shot but unlike most cold setups which are capped a lot higher (temp wise), there iis a Jan 1987 scenario here. An Arctic High (albeit this wouldn't be in its truest form) often frustrates but occasionally can produce the jackpot.

I'm reading this as the ridging up into Scandi is all but nailed (small blue circle), but how far it gets is anything but (red, high spread area around Svalbard)...

It would mean enduring potentially even warmer uppers first but I think most of us would happily take that for a decent shot at this!

Worth adding that any further amplitude of the MJO out of Maritime into the Pacific could well help provide the extra boost required here. Even without increased ppn, the current forecast from most models is already looking pretty decent. I think the best way to look at the MJO potentially going into favourable 6/7/8 territory, whilst we may end up with a 'disconnect', it is unlikely to be detrimental, unlike other phases at moderate to high amplitude.

 

Edited December 22, 2015 by s4lancia

[Cheshire Freeze]

2 hours ago, Ali1977 said:

FI GFS may be pretty close to reality then, really bad for the skiing industry if this is true.

Yes but then as we know, GLOSEA pulls heights further N &W as time goes by with troughing out East. The likely long term progression you'd think eventually from the chart you've posted above.

[MJO]

Hi guys..i want to ask a question 

what is the different between ecmwf eps mean and control ? 

[Mucka]

nick will be pleased with the behaviour of his shortwave on GFS this morning - gold star I would think

 

 

I think GFS may have lost the plot at this point though, not sure I have ever seen two storms so close together.

Edited December 22, 2015 by Mucka

[northwestsnow]

GFS again advertising some amplification with the block doing enough to disrupt the Atlantic resulting in the eventual decline of that god awful euro high,

Really hoping ECM goes a similar way which will put us in the game for some more seasonal weather down the line.

http://www.wetterzentrale.de/pics/Rgem2401.html

GEM thinking along similar lines.

Edited December 22, 2015 by northwestsnow

[northwestsnow]

7 hours ago, bluearmy said:

A glimmer of hope on the extended ECM ens. The strong blocking to our ne forces the upper trough into nw Europe and it seems that it could easily disrupt and slip se, finally removing the euro heights. 

i wonder if the EC32 will pick up this baton?

00 GFS pointing in that direction this morning blue would be nice to ecm drop the grinch mode and give us something to keep an eye on

[knocker]

4 hours ago, MJO said:

Hi guys..i want to ask a question 

what is the different between ecmwf eps mean and control ? 

An ensemble forecast comprises multiple realisations for a single forecast time and location. The different realisations are generated through applying different perturbations to a single control forecast. For the ECMWF medium-range forecasting system, the control forecast is a coarser-resolution realisation of the HRES forecast (the high-resolution forecast). The perturbed forecasts are generated through:

The ECMWF weather prediction model is run 51 times from slightly different initial conditions. One forecast, called the ENS control forecast, is run from the HRES ECMWF analysis. An additional 50 integrations, the perturbed members, are made from slightly different initial conditions which are designed to represent the uncertainties inherent in the HRES analysis . The initial perturbations are constructed using the singular vector technique and perturbations generated from the ensemble of data assimilations

The mean is the mean of the perturbations.

Edited December 22, 2015 by knocker

[Liam J]

Did anyone see the 12z EPS control yesterday? Probably the best charts for cold I've seen this season, 1048mb high out east and It went for an undercut in FI, at T318 it's showing SE'ly winds and -10c 850's into the UK, not much support though and the ECM OP runs really not interested in that scenario. 

Edited December 22, 2015 by *Sub*Zero*

[bluearmy]

8 hours ago, bluearmy said:

A glimmer of hope on the extended ECM ens. The strong blocking to our ne forces the upper trough into nw Europe and it seems that it could easily disrupt and slip se, finally removing the euro heights. 

i wonder if the EC32 will pick up this baton?

 Nope

[Liam J]

Not great news on the ECM monthly update, looking very unsettled and zonal into January especially the further north you are, high pressure to the south or south west and depressions tracking west to east into Europe, not looking as mild as recently though with PM air quite a frequent visitor. 

[Dr. Astro]

1 hour ago, knocker said:

An ensemble forecast comprises multiple realisations for a single forecast time and location. The different realisations are generated through applying different perturbations to a single control forecast. For the ECMWF medium-range forecasting system, the control forecast is a coarser-resolution realisation of the HRES forecast (the high-resolution forecast). The perturbed forecasts are generated through:

The ECMWF weather prediction model is run 51 times from slightly different initial conditions. One forecast, called the ENS control forecast, is run from the HRES ECMWF analysis. An additional 50 integrations, the perturbed members, are made from slightly different initial conditions which are designed to represent the uncertainties inherent in the HRES analysis . The initial perturbations are constructed using the singular vector technique and perturbations generated from the ensemble of data assimilations

The mean is the mean of the perturbations.

You can read more here: 

 

http://www.ecmwf.int/en/research/modelling-and-prediction/quantifying-forecast-uncertainty

[terrier]

Well the ecm 32 dayer is very underwhelming again. Looking at the gfs 00z nothing really showing cold wise. Just more sw winds and rain. But at least today's the longest day so our days get longer after today. Hopefully we might see something better mid Jan. But I won't hold my breath. Happy Christmas to everyone. 

[KyleHenry]

43 minutes ago, bluearmy said:

 Nope

Close but just too large a pool of DAM 496 air over Greenland to put in any resistance.

ECMWF has the correct pattern, whereas the GFS has lost pattern past 144z.

We all know what that means,2/3 week wait for next chance.

Painful as it is to accept for others we are peak El Niño phase for NW Europe but it's no 1997, the year of no winter. 

[IDO]

I still believe there is no MJO signal and that the amplification is from a standing Kelvin Wave, so therefore I am still not expecting the 7-10 days composites of a MJO phase 7 to materialise (Scandi block). The ECM seems to be where I have suspected the pattern to be, a block of amplification moves into our region, that is mobile and flows within the positive AO signature. CFS weeklies are now correcting the signal and week 3 and 4 are now suggesting a return to our default Winter synoptic, with the Azores feeding into the UK from the SW. 

   

That will in my opinion, for at least the south, keep temps above normal, though Nov/Dec warm anomalies are unlikely. The GEFS mean (above) keeps the T850s above average till D16 apart from brief bursts. The GEFS mean at T300 & T384 offer little for cold:

This locked in pattern is looking very likely to pass mid Jan which has been the minimum length I expected. The PV remains a monster so we cannot expect anything cold till this wanes and/or we get some forcing, none look likely till early Jan at the earliest. 

The good news is that the current CET of +5.1c above average will remain very close to this, as apart from a cold front today and Christmas Eve/Day, the very mild uppers look like continuing. Hopefully Knocker will post one of his red charts. Funny how this upcoming wave has given another boost from a warm plume and if this ENSO pattern continues then it may be unfortunate, but future transient amplification may also mean mild rather than cold flows?

 

[Ravelin]

36 minutes ago, KyleHenry said:

ECMWF has the correct pattern, whereas the GFS has lost pattern past 144z.

How can you be so sure of that? At 144z the UKMO to my eyes has a similar pattern to the GFS and it's the ECM that's odd one out... 

[John Badrick]

15 minutes ago, IDO said:

I still believe there is no MJO signal and that the amplification is from a standing Kelvin Wave, so therefore I am still not expecting the 7-10 days composites of a MJO phase 7 to materialise (Scandi block). The ECM seems to be where I have suspected the pattern to be, a block of amplification moves into our region, that is mobile and flows within the positive AO signature. CFS weeklies are now correcting the signal and week 3 and 4 are now suggesting a return to our default Winter synoptic, with the Azores feeding into the UK from the SW. 

   

That will in my opinion, for at least the south, keep temps above normal, though Nov/Dec warm anomalies are unlikely. The GEFS mean (above) keeps the T850s above average till D16 apart from brief bursts. The GEFS mean at T300 & T384 offer little for cold:

This locked in pattern is looking very likely to pass mid Jan which has been the minimum length I expected. The PV remains a monster so we cannot expect anything cold till this wanes and/or we get some forcing, none look likely till early Jan at the earliest. 

The good news is that the current CET of +5.1c above average will remain very close to this, as apart from a cold front today and Christmas Eve/Day, the very mild uppers look like continuing. Hopefully Knocker will post one of his red charts. Funny how this upcoming wave has given another boost from a warm plume and if this ENSO pattern continues then it may be unfortunate, but future transient amplification may also mean mild rather than cold flows?

 

"The good news is that the current CET of +5.1c above average will remain very close to this"

Genuine question; can I ask why is this good news???