Model Output Discussion - 1st - 7th January

[Radiating Dendrite]

Feb 78!!!

The AO Index is taking a dive -

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

I certainly remember the AO index used to be set at -3 , until the last year where it had to move the scale to -6 because of that December High-

I think a few need need to put things into context with changes in the NH flow- the Aleution high IF it develops & gets towards the Artic is on a par if not bigger than the Azores high -

Its Circumference will span nearly ALL of the Arctic, when that happens it does pave the way for good standing 4 wave patterns, in these situations the temp anomalies across 50 N go from a small low variable swings to LARGE swings with big + VE & BIG -VE anomalies its very wasy to see when the NH loads into a 4 wave pattern-

The only concern with this is that NW europe could sit in the warm side of the WAA as opposed to the CAA, although more often than not 4 wave patterns set up in Simlar locales - its whether we get a West or East based -NAO

regards-

Steve

Let's just hope the ECM verifies and does not backtrack.

I think shouting 78" at something shown +200 hours out is a bit premature.

Let's get the negative AO and NAO in place first.

[SMU]

Let's just hope the ECM verifies and does not backtrack.

I think shouting 78" at something shown +200 hours out is a bit premature.

Let's get the negative AO and NAO in place first.

try to distinguish tongue & cheek & read between the lines-

S

[Bristawl Si]

http://www.wetterzentrale.de/pics/Rjma1921.gif

JMA (cannon fodder i know) - indicating a more southerly jet maybe?

[Radiating Dendrite]

try to distinguish tongue & cheek & read between the lines-

But some on hear take what you say as gospel.

Anyway, the ECM is certainly encouraging. We need to see it get to semi reliable though and even more important, the GFS needs to come on board. Let's hope the GFS has been down the pub for the 18z!

[SMU]

To be fair the rest of the post was semi reliable as the Aleution high is going to get going in 7-9 days- however its a large globe - Where does it go- Anywhere towards Russia ( WEST) / over the pole is fine-

I think the 18z will be a stella pub run!

S

[BLAST FROM THE PAST]

try to distinguish tongue & cheek & read between the lines-

S

I have Steve, Feb 78 is not cold enough..... :winky: 18z is still looking way too flat, GFS will come screaming and kicking...one day

BFTP

Edited January 4, 2012 by BLAST FROM THE PAST

[rug]

To be fair the rest of the post was semi reliable as the Aleution high is going to get going in 7-9 days- however its a large globe - Where does it go- Anywhere towards Russia ( WEST) / over the pole is fine-

I think the 18z will be a stella pub run!

S

Keep up the good work , I like the gospel of st Steve .

[bluearmy]

might be worth looking at the 10 day means from ecm and naefs (throwing the parallel gefs in for good measure to see how it differs from naefs)

ecm.......................................................gefs parallel............................................naefs

not too much disagreement and very decent mid jan charts, considering the direction of travel in the strat.

aleutian ridge - ecm not as keen as ncep products but still a mean feature. infact naefs has full blown cut off arctic high ne siberia by T384!!

for me, the most significant development over the past few day or two is that the north scandi segment of the vortex now survives to day 10 at least. infact a feature on the cpc 8/14 dayer. up until recently, most output for day 10 was lifting this out. i think we're still headed the right way but it will be difficult to cope with the ups and downs, run to run considering the winter pattern we've had to put up with thus far.

[Cheshire Freeze]

Slightly less intense vortex around Greenland at 144 hrs, let's see where this takes us.

[Harsh Climate]

Slightly less intense vortex around Greenland at 144 hrs, let's see where this takes us.

Well spotted, the pressure is 20mb higher two!

[Matty M]

We might get a pump up here.

[Harsh Climate]

We might get a pump up here.

I think this is going to be a good run

[SMU]

can I have a link to the NAEFS run please

Steve

[Cloud 10]

can I have a link to the NAEFS run please

Steve

Meteociel - Cartes Ensemble NAEFS ( North American Ensemble Forecasting System)

[bluearmy]

can I have a link to the NAEFS run please

Steve

go onto ensembles on meteociel. its at the bottom. i'm sort of underwhelmed by it at the moment as i think we are being denied seeing what it would look iike using the new parallel gefs data which should give us a better tool.

[ITSY]

20more MBs and less low pressure over Greenland at 180

[SMU]

http://176.31.229.228/modeles/gfs/run/gfsnh-0-264.png?18

largest high EVER?

S

[Cheshire Freeze]

http://176.31.229.22...nh-0-264.png?18

largest high EVER?

S

I was just thinking that Steve, looks huge but also looks wrongly positioned to deliver cold to us?

[January Snowstorm]

More of the same from the 18z

[SMU]

lol goodbye america...

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=204&code=0&mode=1&carte=1

A stunning NH run for indexes like the AO- heading to the lower values of -4, however nothing special for the UK_

S

[mountain shadow]

This latest run was similar to a GFS run a couple of days ago. We have the massive height rises on the other side of the pole with all the lower heights squeezed into our side giving a cold zonal run.

[sn0wman]

lol goodbye america...

http://www.meteociel...&mode=1&carte=1

A stunning NH run for indexes like the AO- heading to the lower values of -4, however nothing special for the UK_

S

If the 18z run came off though, after the 20th the gates would be opened for Arctic air to flood down to the UK. :smilz38:

[bluearmy]

lol goodbye america...

http://www.meteociel...&mode=1&carte=1

A stunning NH run for indexes like the AO- heading to the lower values of -4, however nothing special for the UK_

S

it would be a few days later though. i cant believe that if we get a massive distortion in the polar field such as the 18z shows, we wouldn't be the recipient of deep cold at some point in the fortnight that followed that run.

[lorenzo]

http://www.wetterzen...cs/Rjma1921.gif

JMA (cannon fodder i know) - indicating a more southerly jet maybe?

JMA verification stats are worth a look now and again..not always off on one and shredder material, i read last week it was out gunning GFS at 168.

What a high that is SM !

Great time to be watching the models, looking forward to replaying the NHheights on loop from end Dec > Feb when available.

[johnholmes]

I see folk are mentioning the 6-10 and 8-14 day 500mb anomaly charts which is good to see. I suspect though it may only be because they appear to show support fotr a colder spell not being too far away!

Anyway As most know I keep copies of these just about every day 365 days through the year. They are far more reliable than watching the outputs from the 'synoptic' scale models in my view and I've shown how they can be used along with a suggestion of their success rate. The caveat is that they must show consistency over several days and that is NOAA, ECMWF-GFS with themselves and also with one another.

Over the past 5-7 days NOAA has been totally consistent with the idea mentioned by other posters this evening. That is for +ve heights to move from the Azores region to about 50-52N and around 30W, the Atlantic upper ridge mentioned by some folk from time to time. The other thing it is consistent with, well two really, contour heights rising over the polar regions and -ve heights showing just as consistently over Scandinavia. What is driving this change from say mid December I have no idea. I will leave that to others with better knowledge of events further out on the time scale. ECMWF is issued alongside the GFS version and it has largely followed the NOAA idea, GFS less so, although sometimes it has aligned itself more with NOAA than ECMWF.

The overall idea to me is that pattern change is on the way. Whether, as I posted in the technical thread a day or so ago, it takes the form of surface high pressure WNW or WSW of the UK with lower pressure over the areas E/NE and SE of the UK or a more full on NW positioning of the high is not clear. The other possibility is the surface high, along with its upper ridge, moving over the UK from the SW and setting up over Scandinavia. This is possible, partly thanks to the trough well east of the UK or possibly by the apparent upper trough shown in the -ve areas on the 500mb anomaly charts edging east. I'm not sure how the permanent high over eastern Russia would change in any of these scenarios.

I am pretty convinced though that, regardless of the variable outputs from GFS and to a lesser extent ECMWF, that a pattern change is going to occur within, say 15 days, possibly less.

If its wrong don't blame me, blame the weather! Anyway I will be 6000ft up in the Swiss Alsps hoping either of the ideas I've floated come tofruition.

Edited January 4, 2012 by johnholmes