Model output discussion - Closing in on Christmas

[Scott Ingham]

2 hours ago, bluearmy said:

ok everyone ..... upstream is the issue with the trough in the eastern states ....if that digs then the WAA it generates drives the n Atlantic ridge ala gfs. If it doesn’t dig south with the trough then the flow off the eastern seaboard has a positive tilt and that gives you the flatter solutions ......the more amplified the solution upstream, the more amplified  the solution downstream - the old waves on a rope .....  day 6 isn’t too far away ...hopefully by this evening we have better agreement from the better verifying models as to where we start this. 
 

a concern for coldies would be that the initial Xmas northerly looked like being of note ......that ridge failed and then we looked for the next retrogression (via a second bout of WAA) and ridge to bring the following trough south (perhaps too aggressively) like gfs does. If that fails then are we then possibly looking at a third attempt upstream ...? This is where the good news arrives .....by that stage, the arctic high dropping into n Russia enforces the block to our east which drives the trough s into e Europe ....it can’t head east or northeast ...... I have bookmarked the new year period for a good few days now with signs of a drop south of lower heights into an already cold environment ...... with a trough to our east we run the risk of warm sectors spoiling the fun but we certainly have a ticket from the winning book of tickets here and with developments high up, that book may contain quite a few winning tickets for the next 4/6 weeks ......

so our potential wintry outlook depends on quite a few variables so as ever, take nothing for granted ! 

Outstanding. Frustrating but agreed we could very well need a third attempt. 

With the eamt due to get underway Christmas week there is still a distinct possibility AAM is yet again being under modelled in my opinion and either way the best period of weather has always been signposted last 3rd of Jan and into Feb with events high up

[That ECM]

Gfs sticks to a similar thought as earlier.

[Valleyboy]

55 minutes ago, That ECM said:

This would suggest not. What have you based this on?

Based on the models that I’m viewing and 50 years of weather watching Experience.  I’m not normally wrong but wish I was, as I am a coldie.  The thing is, you have to keep it real, no matter how annoying it can be.

[TSNWK]

Just now, That ECM said:

Gfs sticks to a similar thought as earlier.

Slightly flatter I thought at 144.. subtle move towards ECM... 

[Skullzrulerz]

3 minutes ago, That ECM said:

Gfs sticks to a similar thought as earlier.

High Pressure definitely is close to the UK? Looks a lot flatter upstream wise so moving towards ECM 

[sheikhy]

Yeh slowly but surely it will start creeping back towards ecm and then eventually ukmo!!!if gfs cant even get a grip of that low near the azores at just 84 hours out then it has no hope later on

[mushymanrob]

43 minutes ago, johnholmes said:

Sat 19 December 500 mb anomaly update

No ec-gfs for the second day, so just Noaa.

Its 6-10 seems to confirm the 8-14 day chart from 24 hours ago. The meridional pattern is converted during the 6-10 day period into a flatter flow in the UK area. It is still meridional in the far west (Pacific area) and into the east of n America. The 8-14 is a bit of both if you look at it. Overall there is no deep cold predicted by the NOAA charts, with  a Christmas ridge giving most places a dry cold couple of days. Isolated sleet/snow showers close to windward coasts for the north perhaps.

Beyond that and EC synoptic suggests a strong generally westerly and rather cold windy day or two turning into a very cold more northerly flow. GFS has this by 27 th December. [b]Do the anomaly charts support this? I am not sure if they do or not.[/b] Maybe another 48 hours will make it clearer?

Anyway the NOAA chart is below for folk to decide along with the usual mayhem over each chart as the daily synoptic charts role out.

Enjoy.

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

 

bib.... this concerns me too, because i dont think they fully support what the ops are suggesting, id prefer to see the green contour lines dip further south of the UK. Looking at their own confidence ratings, 4/5 for the 6-10 day but only 2/5 for the 8/14 day period. As you say, more runs needed.

[That ECM]

2 minutes ago, Skullzrulerz said:

High Pressure definitely is close to the UK? Looks a lot flatter upstream wise so moving towards ECM 

Broad scale, similar to previous run. You may have noted or not, I rarely if ever suggest one outcome is “right or wrong” I comment on the output. Seen over many years each model has been right and wrong. I’m happy to watch with interest and have no desire of trying to call it. 

Edited December 19, 2020 by That ECM

[alexisj9]

5 hours ago, Mucka said:

The arctic high is really helping with preventing the low moving more E and forcing it S/SE. 

This will be another Boom run.

ICON is on another planet by this point which just goes to show how small differences in the near term can make dramatic differences even by the mid term.

ICON/GFS 168

That's why I'm still watching that low, what it does is important going forward, and might still not be modelled right, we will see in the wash, as they say. Would like to hope the met model is wrong this morning though.

[Matt H]

2 minutes ago, Skullzrulerz said:

High Pressure definitely is close to the UK? Looks a lot flatter upstream wise so moving towards ECM 

Are we looking at the same run? 

[Day 10]

2 minutes ago, Skullzrulerz said:

High Pressure definitely is close to the UK? Looks a lot flatter upstream wise so moving towards ECM 

Only on my phone but from what I can make out, I would only say slightly flatter. 

[Matt H]

1 minute ago, Day 10 said:

Only on my phone but from what I can make out, I would only say slightly flatter. 

Marginally flatter than the 00z but still looks broadly the same to me, much better than the ECM. Those describing it as flat upstream are living in some sort of parallel universe.

[Day 10]

Just now, Frosty Winter said:

Marginally flatter than the 00z but still looks broadly the same to me, much better than the ECM. Those describing it as flat upstream are living in some sort of parallel universe.

Fully agree  

[sheikhy]

Beauutyyyyyy at 192 hours!!ridge straight into greenland!!!good to view nothing more lol!!!!

[IDO]

D8 charts from 06z and 0z, within the margins of error so pretty much the same:

06z>  0z> 

That is good as it means that the modelling of the low early on seems to only make a difference in timing, a slight delay to the pattern if it crosses the UK. We shall see how it progresses from here...

 

[Matt H]

Comments on here: The GFS 06z is flat upstream and a big downgrade from the 00z.

The actual run in question:

[sheikhy]

Hello polar vortex at 204 hours!!!literally a piece of the vortex right over us❄

[booferking]

2 minutes ago, Frosty Winter said:

Marginally flatter than the 00z but still looks broadly the same to me, much better than the ECM. Those describing it as flat upstream are living in some sort of parallel universe.

That's were cation is required run that marginally flating over a series of gfs runs then you end of like EC nice to look at all the same.

[Ice Day]

No complaints from me at 210 - just gorgeous, and so many options moving forward!

[Matt H]

Just now, booferking said:

That's were cation is required run that marginally flating over a series of gfs runs then you end of like EC nice to look at all the same.

I completely agree, big ECM/UKMO runs later!

[bluearmy]

57 minutes ago, northwestsnow said:

We need GEFS to be right.

EC will get flatter and flatter unless it pulls some Atlantic amplification out of the bag , sharpish.

The binary nature of the cluster groupings means we either get the cold plunge or a cold ridge.  If a middle ground solution verifies then it calls into question the whole point of clusters! 

10 minutes ago, TSNWK said:

Slightly flatter I thought at 144.. subtle move towards ECM... 

as gfs often does, it moves slowly towards the European models (and gem which since its upgrade often looks like ecm)

however, with that trough in the east of n America, the latest run is a little less dug than the 00z but it isn’t drifting more positively tilted run to run which gfs would usually do if it was simply wrong 

[Battleground Snow]

Deeper cold filtering into northern Scandinavia on this run

 

[I remember Atlantic 252]

A bit like 4th Dec 2020? uppers look pants! FI I know

[booferking]

1 minute ago, Frosty Winter said:

I completely agree, big ECM/UKMO runs later!

Hopefully we can see some narnia on them then we have some hope.

[Skullzrulerz]

5 minutes ago, Frosty Winter said:

Comments on here: The GFS 06z is flat upstream and a big downgrade from the 00z.

The actual run in question:

Because as we have seen on the GFS the last serval runs it has slowly been flattering the amount of upstream run by run 

It will most likely be a mixture of the ECM which should be resolved soon