Model output discussion - 5th December 2016 - Into Winter we go

[fergieweather]

UKMO Seasonal Team meets this morning to discuss the situation at present and signals/output for rest of winter. I might be able to offer an update later. Meanwhile, current thinking is that downwelling from current phase of strat consolidation will manifest into higher likelihood of a zonal/mobile period ca. 1-2 weeks from now. This is suspected to be temporary: both GloSea and ECMWF products are keen on blocking resuming throughout 1st half of January (at least). 

[Weathizard]

28 minutes ago, feb1991blizzard said:

Here she comes.

 

Snow in Murrland at 240.

What makes the GFS Para produce charts like this yet the OP/control never sing from the same hymn sheet? Seen this several times in recent weeks where the GFS P has produced the goods meanwhile the standard model shows the normal dirge.

[Scandinavian High.]

This has been consistent high looks like slowly pushing north cold coming in from the south east.

[chris55]

GFS Para is the best run I've seen in a while towards the second half. And to be honest it's not to dissimilar from ECM at 192. It looks like the modelling out east is slightly more favourable on the GFS para and this allows a slightly better positioning of the block and subsequntly brings in the proper easterly. 

The atlantic and U.S pattern is similar on both its the high to our east that is having the positive effect on the para acting as a more efficient block.

gfs para vs ECM 

Edited December 13, 2016 by chris55

[chris55]

5 minutes ago, abbie123 said:

This has been consistent high looks like slowly pushing north cold coming in from the south east.

With Ian suggesting a more zonal flow at this time let's hope we can get a decent block in place to deflect it south :0  

[Faronstream]

2 minutes ago, abbie123 said:

This has been consistent high looks like slowly pushing north cold coming in from the south east.

Too bad that the 850 hpa temperatures are relatively mild and no snow the last days before christmas. But i take this rather than mild and wet

[Ali1977]

11 minutes ago, fergieweather said:

UKMO Seasonal Team meets this morning to discuss the situation at present and signals/output for rest of winter. I might be able to offer an update later. Meanwhile, current thinking is that downwelling from current phase of strat consolidation will manifest into higher likelihood of a zonal/mobile period ca. 1-2 weeks from now. This is suspected to be temporary: both GloSea and ECMWF products are keen on blocking resuming throughout 1st half of January (at least). 

Is it looking like we could get something cold in by Xmas day on your models Ian? It looks a bit early on the usual suspects but the GFS p shows cold air from the SE in time for Xmas day . I see you mention 2 weeks so guessing it's not looking likely!!

Edited December 13, 2016 by Ali1977

[bluearmy]

Peeps - there is little point hanging your hats on these small cold pools running around the scandi ridges. So much has to fall into place - it has happened before but 90% of the time the pattern corrects as the clock ticks down to day 8/10.

the 46 wasn't notable for the persistence of high height anomolies to our east and northeast. However, no sign of euro height drops until the back end of the run and the 850's above average pretty well throughout over n Europe. 

its a decent background for seasonal surface conditions and far better than a jet firing right through nw Europe. It won't be accurate in entirety so coldies hope it has the blocking  correct to the east and wrong over Europe to our south !

[Blizzard 63]

R.I.P  ian

[Malcolm Edwards]

Slightly of topic and not stating the bleeding obvious,but I've noticed a certain tabloid is trying to derail our chances of snow with Armageddon headlines.why do they do this...

[Bobd29]

8 minutes ago, Malcolm Edwards said:

Slightly of topic and not stating the bleeding obvious,but I've noticed a certain tabloid is trying to derail our chances of snow with Armageddon headlines.why do they do this...

Simple answer...gullible people buy more papers with sensational headlines, never let the truth get in the way of a story!

[Polar Maritime]

Just discussion on the Model Outputs please, There is a media thread already open.

Thanks.

[No Balls Like Snow Balls]

ECM ENS 500HPA 28 day height anomaly updated yesterday.

 

 

[festivalking]

Opps the block over the UK is crumbling on this run. The joys of model watching you are never more than 6 hours from a mood change!

[Man With Beard]

43 minutes ago, bluearmy said:

Peeps - there is little point hanging your hats on these small cold pools running around the scandi ridges. So much has to fall into place - it has happened before but 90% of the time the pattern corrects as the clock ticks down to day 8/10.

the 46 wasn't notable for the persistence of high height anomolies to our east and northeast. However, no sign of euro height drops until the back end of the run and the 850's above average pretty well throughout over n Europe. 

its a decent background for seasonal surface conditions and far better than a jet firing right through nw Europe. It won't be accurate in entirety so coldies hope it has the blocking  correct to the east and wrong over Europe to our south !

I noticed those 850s too when I looked again this morning. Would suggest not much getting around the block from the east. 

I'm guessing Ian's note above suggests the Met Office are not convinced by the latest ECM46 nor the GEFS for the period around Christmas - it sounds more along the lines of the ECM op?

[Paul_1978]

Falls in with Ian's message from earlier - mobility in a week or so (reflected in output), but possibly (hopefully) only temporary. No worries from me.... but as always it's only one run.

[shotski]

I think this might have something to do with the jet stream potentially firing up, amazing 2 m temps in Northern America. 

[Summer Sun]

8 minutes ago, festivalking said:

Opps the block over the UK is crumbling on this run. The joys of model watching you are never more than 6 hours from a mood change!

 

In line with Ian's thought's earlier of something more zonal circa 1 to 2 weeks from now

[Ravelin]

4 minutes ago, Paul_1978 said:

Falls in with Ian's message from earlier - mobility in a week or so (reflected in output), but possibly (hopefully) only temporary. No worries from me.... but as always it's only one run.

Which may or may not be supported by it's ensemble suite.

Seems that different from the last few GFS runs that it's got to be looked at with suspicion. Then again, nothing can be dismissed.

Looking for the positives, possibility of snow over higher ground in Scotland in the run up to Xmas?

 

[fergieweather]

1 hour ago, Ali1977 said:

Is it looking like we could get something cold in by Xmas day on your models Ian? It looks a bit early on the usual suspects but the GFS p shows cold air from the SE in time for Xmas day . I see you mention 2 weeks so guessing it's not looking likely!!

Sorry, I mis-wrote part of my posting (flu!). What it *should* have said is we are seeing a period of strengthening SPV, which ultimately could manifest into a period of increased zonality/mobility with a lag time of 1-2 weeks. I didn't mean necessarily 1-2 weeks from now. The favoured period is late Dec-early Jan for this (which we suspect is why Glosea has been playing ping-pong with balance between mobile v blocked members into that period... the blocking ones ultimately win, *but* UKMO suspect the output from it & ECMWF could be masking a temporary phase of zonality into turn of month). I'm told a UKMO blog may be forthcoming re current/recent period of uncertainty leading into Xmas; this on the back of the Seasonal Team/Hadley meeting today at Exeter (which will be followed by a lengthier one on Monday to discuss J-F-M as a 'job lot' ahead of next contingency planner doc being prepared).

[Singularity]

I'm just going to keep watching this as it adjusts. The darker green is the projection of 11th, lighter is today's. Just need to keep it going and the jet should tend to buckle more in the 7-14 day range. In the meantime, individual runs will inevitably vary in how they handle the momentum budget... relatively small yet before long significant differences between the 00z and 06z.

I concur with some others on here on possible brief zonality as in times past we've often seen the models break down a block and assume that a zonal flow then persists, only for this to prove erroneous with upstream amplification quickly allowing the blocking to fight back. Some past winters have had spells where the block keeps reaching very close but not quite close enough... we need to go a step further for once. That brings me to the MJO again and so the cycle repeats!

[Paul_1978]

Why can't we have it where we get "zonality", but the block holds = "zonality" sliding under the block. Then we get the best of both worlds  (but with a potentially snowy result).

[Methuselah]

Morning all...You'll forgive me if I can see absolutely no sign of a 'wall of snow' anywhere on that run...Reports of an 'unpredicted' solar filament might just be imminent?

[jvenge]

3 hours ago, Seasonality said:

You're right, I'm being optimistic. There has definitely been a trend re: the pulses of cold air. @daz_4 has highlighted this well in a couple of posts. I am heartened by a seasonal feel to the festive period though and also pleased by the increasing presence of lower pressure. Seasonal temperatures at or just below freezing are great but a little snow would be lovely.

PS I think you meant the cold isn't going as far west as predicted by the models, it has even shown as pushing into western Europe but then in reality has dived south into Greece and the Balkans for example.

I see it hasn't made it quite as far west on the 06z. This is a recurring theme from the GFS for the past month or so.

[BLAST FROM THE PAST]

GFS 06z following ECM and am not surprised.  Unsettled Xmas the fav in my view and hopefully a fair bit of pM air too.  This period went Pete Tong due to the very stubborn HP so onto next watch period for me.  

 

BFTP