Model Output Discussion; into 2015

[Captain Shortwave]

Mild sector looks very transient on friday before much cooler air on Saturday on GFS 12Z OP, don't overexaggerate the coming weeks mildness, you also forgot to mention the warm sector bringing a spell of heavy rain friday.

Same old story though isn't it, these cooler spells bring temperatures of 4-6C which in the scheme of things is only around 2 or 3 degrees below normal, meanwhile those milder spells (however transient) can deliver daily CET of 10C+. Again like last month despite a lot of claims about the lack of milder weather, we will likely be sitting at a above to well above average figure in respect to the monthly average.

Temperatures at midday from the parallel

Tomorrow

4 or 5C, strangely not as cold as the models were saying a day or so ago. Some areas of course colder where fog is likely to linger.

 

Monday

Generally 7-9C though some areas do reach double figures.

 

Tuesday

Mild in the east (9-11C), cooler conditions spreading east during the day with an associated cold front.

 

Wednesday

Reverse scenario with a warmth front pushing eastwards, the east is near or slightly below normal (5-7), whilst double figures are achieved over Ireland with these spreading east overnight.

 

Thursday

Temperature near or a little above normal in the south, cooler than average in the north.

 

Friday

The day of the potential windstorm over Scotland - double figures across the board. Overnight is very mild.

 

Saturday - a week away.

The very mild weather is gradually displaced south eastwards. But the south gets another mild day.

 

Overall it's a typical story of a mix of tropical maritime and polar maritime incursions. Neither taking total control. I don't understand your complaint as my post was making the point where there is the greatest movement away from average (in terms of temperature). Ultimately the week ahead shows temperatures a little above normal (a +1C anomaly looks likely). This is also backed up by other models and professional forecasts. The second half of the month looks to be cooler but at the present time I see not much more than a repeat of December where we may see a spell of 3-5 days of colder and drier weather which will bring temperatures over the month to near normal levels.

 

Up to day 10, no sign of a relenting jetstream on the GFS/Parallel or GEM, the most interesting is some very low heights developing over the UK into the start of low-res potentially bringing widespread heavy rain and strong winds. GEM/Parallel keep a similar theme to day 10 before again both the GFS/Parallel show a change to colder and drier conditions at the end of week 2/start of week 3. I must say that the parallel does mange to achieve the same result as the previous couple of runs with a north/north easterly establishing which is nice to see (consistency but is it reliable?)

Edited January 3, 2015 by Captain shortwave

[Banbury]

http://modeles.meteociel.fr/modeles/gfsp/runs/2015010312/gfsnh-0-276.png?12

http://modeles.meteociel.fr/modeles/gfsp/runs/2015010312/gfsnh-0-300.png?12

http://modeles.meteociel.fr/modeles/gfsp/runs/2015010312/gfsnh-0-324.png?12

http://modeles.meteociel.fr/modeles/gfsp/runs/2015010312/gfsnh-0-348.png?12

http://modeles.meteociel.fr/modeles/gfsp/runs/2015010312/gfsnh-0-372.png?12

http://modeles.meteociel.fr/modeles/gfsp/runs/2015010312/gfsnh-0-384.png?12

A dream from GFSP

Edited January 3, 2015 by Banbury

[Woollymummy]

Thank you for the reply. If the cold air comes far enough South in the USA will it have the same effect on the jetstream as the displaced vortex did last year? Therefore giving us some possibly some gales?

[bluearmy]

Thank you for the reply. If the cold air comes far enough South in the USA will it have the same effect on the jetstream as the displaced vortex did last year? Therefore giving us some possibly some gales?

Funnily enough, the the cold air coming south again later in that gfsp run actually helps to amplify the pattern to the degree that it blows up the greeny ridge. So a cold blast in the east states could actually work in our favour this year. don't assume cold conditions there will result in the same thing for us as last year.

[Jason M]

GFSP in FI Greenland heights shock!!!

 

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=384&mode=0&runpara=1

 

Of course at that range, not worth reading too much into. I suspect come the day a more traditional mid Atlantic ridge will be the outcome, but its still nice see some decent eye candy.

 

If we start to see lots of these though on GFS I'm personally going to be very wary indeed of buying into it as I think GFS (and its ensembles) have a lot of previous around Greenland height rises (and I don't just mean from the pre Christmas fun and games). 

 

All of that said, developments today can only be seen as positive.

[TEITS]

Just catching up on the output and the first striking feature is the 06Z GEFS ensembles. Some were worried the mild, zonal spell would last all of Jan and yet according to the ensembles & GFS Ops its only 7 days.

 

http://max.nwstatic.co.uk/ensimages/ens.20150103/06/prmslAberdeenshire.png

 

The period from the 10th Jan to 15th suggest the zonal spell will continue but will be cold/cool rather than mild due to the flow veering WNW, NNW,ly.

 

The 15th Jan onwards and yet according to the GEFS Iceland SLP mean the 06Z GFS SLP was much higher. However this has been the 6th run in a row to be so with the control always the same.

 

http://max.nwstatic.co.uk/ensimages/ens.20150103/06/prmslReyjavic.png

 

So my summary remains unchanged. Turning colder but still unsettled from the 10th Jan and possibly becoming even colder from the N/NE around 15th Jan. Obviously subject to change but that is the trend.

[BLAST FROM THE PAST]

This has been the phantom winter thus far be it Strat warming and northern blocking.  Although nice to see it is very deep FI and just something to be kept an eye on.  It could be that it is picking up early on something serious [as 2010 showed] and with all the early positives its not beyond realms of reason but having said that look at where we currently are and lets tread cautiously with feet on the ground.  But if I must

 

 

:smiliz19:

 

BFTP

[knocker]

Ho Ho said Rowley. 1070mb Greenland high, disruption of the jet and the magic of their singing casts a spell.

http://weather.graphics/gsm/ygfs_t1534_global.php#

 

[BLAST FROM THE PAST]

Ho Ho said Rowley. 1070mb Greenland high, disruption of the jet and the magic of their singing casts a spell.

http://weather.graphics/gsm/ygfs_t1534_global.php#

Indeed Knocker 1070 is quite an ask

 

BFTP

[snowblues]

As a basic trend I will be monitoring the trend for high pressures being centred over the pole enforcing the cold pool to our NE IF it enters a reasonable time frame.That didn't last long i already have.

[snowking]

It may be wise for now to remain a little cautious about FI GFS (and indeed GEFS) output. Why? Well the GEFS is fairly solidly behind a progression towards MJO phase 7 (unfortunately there are issues with the MJO images today), however it is rather isolated in this assertion, with just some limited support on offer from the BOM:

 

 

Otherwise we see the other major suites repressing the signal in to Phase 6:

 

 

(Should be noted the last one there from MOGREPS-G may be a little more difficult to call)

 

We can see where the FI GFS suggestions are coming from if we take a look at the Phase 7 composite:

 

 

However during the previous MJO wave the GEFS was pretty poor. That is not to say that will be the case this time around, but right now it looks very much like GFS v the rest.

 

Until we see a more coherent signal, caution is advised

 

SK

[Barry12]

GEFS control run continues the trend along with the GFS and GFS P

 

[Harsh Climate]

It may be wise for now to remain a little cautious about FI GFS (and indeed GEFS) output. Why? Well the GEFS is fairly solidly behind a progression towards MJO phase 7 (unfortunately there are issues with the MJO images today), however it is rather isolated in this assertion, with just some limited support on offer from the BOM:

 

 

Otherwise we see the other major suites repressing the signal in to Phase 6:

 

 

(Should be noted the last one there from MOGREPS-G may be a little more difficult to call)

 

We can see where the FI GFS suggestions are coming from if we take a look at the Phase 7 composite:

 

 

However during the previous MJO wave the GEFS was pretty poor. That is not to say that will be the case this time around, but right now it looks very much like GFS v the rest.

 

Until we see a more coherent signal, caution is advised

 

SK

 

 

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. : )

Edited January 3, 2015 by Harsh Climate

[MR EXTREMES]

Didn't we see a Greenland high trying not so long ago ?

If I remember rightly the pv was not at strength like it is now!.

If it continues for the next five days with other models suggesting the same then the guard is dropped.

But that's not to say a 1070mb Greenland height is not eye candy!.

But in honesty very unrealistic considering in 09/10 Greenland heights reached 1050mb maybe 1060mb but that was the most exciting block I seen for some years.

So although beautiful to see very unlikely also the nao and AO were pretty amazing to not likely to see that this winter.

[bluearmy]

There was a synergy between the 00z gefs and 00z ECM extended.

There are enough varying options on the gefs to make any assumptions a little premature but the fact that the anomolys are showing high to the west and low to the east is promising at this stage. The next few days will reveal if a) the signal begins to firm up and b) does it look to become mobile again thereafter?

[Snowman.]

Anomalies

 

 

 

Very strong signal for Height rises in the mid Atlantic which has been showing in the GEFS for a while now.

 

Didn't we see a Greenland high trying not so long ago ?
If I remember rightly the pv was not at strength like it is now!.

If it continues for the next five days with other models suggesting the same then the guard is dropped.

But that's not to say a 1070mb Greenland height is not eye candy!.

But in honesty very unrealistic considering in 09/10 Greenland heights reached 1050mb maybe 1060mb but that was the most exciting block I seen for some years.

So although beautiful to see very unlikely also the nao and AO were pretty amazing to not likely to see that this winter.

 

True. Very true indeed so caution is obviously advised. But the trend is there and it only gains stronger so it can't be ignored especially when both GFS runs arrive to similar synoptics just the potency is the change.

 

 

And to give back life to the coldies there's always light at the end of the tunnel.

 

Edited January 3, 2015 by SN0WM4N

[The PIT]

Well looking a bit closer in FI land this little feature is something that we need to keep an eye on.  Otherwise bar Sunday and Wednesday generally on the mild side and on some days it looks more like early march than early Jan.

 

[AWD]

12z GEFS for East Iceland are interesting;

Pretty clear signal for a pressure rise in that area in 7+ days time. What sort of pressure rise and how this will affect the North Atlantic weather pattern is much less clearer at this stage.

Op, Paralell and Control pretty much the 3 most bullish runs in this respect.

Edited January 3, 2015 by AWD

[David Morse]

I'm guessing around the 18th dec 2014. don't have the time to check if out but anyone with 5 mins can check the archive gfs/p fi's on meteociel. Maybe not in the same detail but there were some very wintry runs around that timescale.

 

I'd be delighted to look for you if you point me to the link. But I would have looked at the outputs on GFS, PFSP and ECMW plus more every day myself but never saw this set up, most of those were northerly set ups, polar express solutions.

[Harsh Climate]

12z GEFS for East Iceland are interesting;

image.jpg

Pretty clear signal for a pressure rise in that area in 7+ days time. What sort of pressure rise and how this will affect the North Atlantic weather pattern is much less clearer at this stage.

Op, Paralell and Control pretty much the 3 most bullish runs in this respect.

 

I think these baby steps to something more fruitful have certainly gained pace over the last day or so.

 

A huge IF but if the gfs does prove to be close to the mark in what it's showing in two weeks time, It would be an almighty personal victory for the GFS  :w00t:

[snowking]

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. : )

 

Hi HC,

 

Both the ECMWF and JMA MJO forecasts go out beyond day 10 (out to day 15 I believe) - the MOGREPS forecast displayed there only goes to 10 days, hence the attached note.

 

It is in that crucial Day 10-15 period that the disagreement takes place in terms of the MJO phasing. As stated, just because the GEFS was poor on predicting it last time does not mean that will necessarily be the case this time, but it would be wise to remain cautious until we see a more unanimous agreement between suites on this signal. Still some question marks as to whether this is MJO induced, but given the close resemblance to MJO phase 7 composites that would be an acceptable assumption for now.

 

SK

Edited January 3, 2015 by snowking

[David Morse]

I'm guessing around the 18th dec 2014. don't have the time to check if out but anyone with 5 mins can check the archive gfs/p fi's on meteociel. Maybe not in the same detail but there were some very wintry runs around that timescale.

 

Hi Bluearmy; I was looking back at previous posts and this chart was posted on the 21st dec for the 28th dec, its a cold set up, but low is to the north east and its polar flow. http://www.meteociel.fr/modeles/jma/runs/2014122112/JN168-21.GIF?21-12

Edited January 3, 2015 by David Morse

[chionomaniac]

Hi HC,

 

Both the ECMWF and JMA MJO forecasts go out beyond day 10 (out to day 15 I believe) - the MOGREPS forecast displayed there only goes to 10 days, hence the attached note.

 

It is in that crucial Day 10-15 period that the disagreement takes place in terms of the MJO phasing. As stated, just because the GEFS was poor on predicting it last time does not mean that will necessarily be the case this time, but it would be wise to remain cautious until we see a more unanimous agreement between suites on this signal. Still some question marks as to whether this is MJO induced, but given the close resemblance to MJO phase 7 composites that would be an acceptable assumption for now.

 

SK

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.

[fergieweather]

Hi HC,

 

Both the ECMWF and JMA MJO forecasts go out beyond day 10 (out to day 15 I believe) - the MOGREPS forecast displayed there only goes to 10 days, hence the attached note.

 

Not sure about the website you cite, but native EC version goes to day 20; MOGREPS to 15.

[Mucka]

JMA has snow chances for next weekend too prior to any possible pattern change and more sustained cold shot.