Model Output Discussion 29th December - Into mid-Winter.

[northwestsnow]

12z gfs is increasingly wet and windy as we move through next week.

In fact its vile, was hoping for some undercutting ala 0z ecm but gfs not interested it would seem, then again IMHO its a pile of junk so fingers crossed for a different ecm..

 

[The PIT]

Well another disappointing run from gfs. A few days of colder weather then back to mild again. FI does draw some continental air back in but fails to undercut. Whether that verifies or not is another matter. Deep FI where most have been finding cold doesn't really show any. However it does have some stormy weather which has been lacking this winter.

So at the moment it looks cold for a few days brief warm up then brief cool down again. Looks like it will be mostly dry as well away from north west. If it continues the dry theme we could have problems further down the line.

[feb1991blizzard]

1 minute ago, frosty ground said:

I think I've seen one chart showing a big convective easterly at 240 hours. And I am pretty sure most people hoped it would happen but didn't state that it would.

You are of course always welcome to call people out for predicting something that isn't there. So why haven't you?

I'm just saying it works both ways, I started this winter on a positive but realised about 2 days into December that it just wasn't going to happen.

BTW right on cue now the GFS has the mid - upper strat vortex (albeit stretched) guess where? back over the pole, unless we cn reverse that trend over coming runs then its a very small window of opportunity before more mild much takes over late feb and into March.

[bluearmy]

Those of you pinning your hopes on something coming from the potential SSW - most recent gfs op and parallels have taken lower temps and heights back towards the pole by day 16 

waiting to see if the gefs begin to follow 

[Polar Maritime]

The Atlantic shown winning out into wk2 by the GFS. Certainly be refreshing after the dry stagnant pattern we have been stuck in.

Edited January 20, 2017 by Polar Maritime

[Singularity]

A whole new idea from the 12z GFS days 10-16 in that it stretches out the vortex at 30 hPa from Siberia to Greenland and then attempts a split of sorts. In the troposphere there is a corresponding division with a dominant Canadian vortex but also a weak Siberian one, with the two separated by a major block which, due to the much-weakened nature of the vortex, is able to loom large no far E/NE of the UK by day 16.

The only consistency between this run and the previous half-dozen or so is the tendency to fire the jet right down to the Mediterranean - but with the MJO being projected to become negligible days 6-12, it sees no signal to buckle that jet at all and so we see a chain of broad, fairly deep low pressure systems roaring at us but tending to hit a brick wall once they've got here. Reminds me of Nov 2009.

Thing is though, if the NCEP comments from a couple of days ago turn out nearer the mark, the MJO won't become negligible in that period, and we may well see some phase 3 type forcing on the upstream pattern days 5-10 which in turn should encourage lows to keep dropping into Europe in the 8-12 day range. This would have implications for both GFS and ECM output as neither are seeing such an MJO progression at this time.

Whether that forcing will actually turn up, let alone be strong enough to overcome the impacts of the transferal of a lot of cold air to NE Canada, remains to be seen.

All we can know for sure is that there's a chance the models, including whole ensemble suites, are overlooking an important contribution from the tropics in the mid-range. Just a chance. 

Fact is, though, it would be impressive going to remain under generally cold conditions all the way up until either the MJO moves through the Pacific at amplitude (impacts likely by 2nd week of Feb in that scenario) or we see impacts from a SSW in the upper stratosphere propagate down (uncertain if this will happen in the first place but impacts would likely be 2nd half of Feb). So a milder, even stormier interlude is not an unreasonable notion.

[Polar Maritime]

Some post have been hidden, Please keep chit chat to the banter/moan thread and continue with 'Model Output Discussion'

Thanks.

[Weather-history]

32 minutes ago, northwestsnow said:

12z gfs is increasingly wet and windy as we move through next week.

In fact its vile, was hoping for some undercutting ala 0z ecm but gfs not interested it would seem, then again IMHO its a pile of junk so fingers crossed for a different ecm..

 

It doesn't look wet next week to me. Infact, it is quite dry for a lot of week, a belt of rain finally makes it to the eastern side, a week on Monday

Rainfall totals to midnight Wednesday/Thursday and by the looks of it the totals to a week Sunday morning

 

Edited January 20, 2017 by Weather-history

[Weather-history]

20 minutes ago, Weather-history said:

It doesn't look wet next week to me. Infact, it is quite dry for a lot of week, a belt of rain finally makes it to the eastern side, a week on Monday

Rainfall totals to midnight Wednesday/Thursday and by the looks of it the totals to a week Sunday morning

 

And to a week Sunday morning. If that is the case then January will be below average rainfall wise

[booferking]

5 minutes ago, Weather-history said:

And to a week Sunday morning. If that is the case then January will be below average rainfall wise

That chart shows plenty of rain???

Edited January 20, 2017 by booferking

[seaside 60]

2 minutes ago, booferking said:

That chart shows plenty of rain???

For you guys yes.
For most of England under 2mm.

[Weather-history]

1 minute ago, booferking said:

That chart shows plenty of rain???

That's rainfall accumulations from now to the date of that chart.

[Great Plum]

Main 12z gfs out of sync between 27-29 Jan...

[Purga]

4 hours ago, bluearmy said:

What seemed significant to me on the eps this morning was the mean jet in the extended period continuing to drift ever south so that little of it is left across the south of the uk. we could be drifting towards a mean undercut or a very unsettled and potentially windy spell. 

the key will be how much of a jet streak we get in the 8/12 day period - any relaxation on the prediction.and the block should be able to force it to undercut convincingly

 

 

Some of the extended 51 ecm ensembles suggest an easterly at T+360 and rather more (but still a minority) are showing a block to the E/NE with trough disruption close to the UK. There are some signs starting to appear in the far reaches of FI output & it will be interesting to see how or if this develops.

[chris55]

12z ECM will be interesting in the 144/168/192 period...can we build on the 00z attempt at lowering heights down into Iberia with the possible undercut or will it be a case of "pancake day coming early" (being flatter) we shall see.

[bobbydog]

I'm going to make a bold statement and and say we will see some proper snowy winter weather, just outside of the range of the models. So I'm not too worried, at this stage, about the lack of cold being shown.

Do not underestimate the power of the 'warm' side...

 

[chris55]

Chinese model once again teasing us lol. Though it goes wrong at about t92 so don't place any faith in it hahaha.

[chris55]

120 looking very good shape wise to our far north east, IF we could get an undercut we would be in business!

[Summer Sun]

After a drier than average December, it's looking like January will end up very dry too very little rain for at least another week

[bluearmy]

a combination of yesterdays and todays day 6 charts would be good with yesterdays atlantic profile and todays e European. however, that's not how it works !

[chris55]

ECM 144 looking a lot more conducive to a proper high lat scandi high developing compared to UKMO for the same period, that Svalbard low is a lot weaker on ECM. As long as we dont see a sinking trend the higher lat block from ECM is much better.

ECM 144

 

UKMO 144

[chris55]

So many changes out east, but for now at least for the UK looks to be on the wrong side of things with the Atlantic pushing to far east.

However the cold is a lot further west than the same time on the 00z. 

00z

12z

[nick sussex]

That deep cold pool to the east may aswell be on Mars as theres no chance of that getting west with all that energy running over the top and no amplification upstream at the crucial timeframe.

The MJO forecasts have gone the wrong way today, but its whether the models are dealing with the correct signal as the last few weeks its the VP200 index which has been more accurate.

At least the Azores high has been flattened but overall it looks like a stale mate and the more positive trends initially to disrupt more energy se'wards have hit the buffers.

The ECM T240hrs has the jet running further south and isn't a bad chart in its own right but its the time it takes to get there.

Edited January 20, 2017 by nick sussex

[booferking]

Nice to see the Atlantic coming fully through days 8,9,10 with some colder uppers in the latter with a jet increasingly running South hope this trend continues.

[blizzard81]

17 minutes ago, nick sussex said:

That deep cold pool to the east may aswell be on Mars as theres no chance of that getting west with all that energy running over the top and no amplification upstream at the crucial timeframe.

The MJO forecasts have gone the wrong way today, but its whether the models are dealing with the correct signal as the last few weeks its the VP200 index which has been more accurate.

At least the Azores high has been flattened but overall it looks like a stale mate and the more positive trends initially to disrupt more energy se'wards have hit the buffers.

The ECM T240hrs has the jet running further south and isn't a bad chart in its own right but its the time it takes to get there.

It really is a tortuous winter isn't it lol. I think (or maybe like to think) that even the ecm is struggling with this set up. However, one way or the other it looks like we will know by the end of the weekend about the extent of trough disruption to our south come the weekend of 28th/29th Jan. If that is not favourable then it is on to the strat last chance saloon. From what I have read this evening though even this might be hitting the buffers lol! If so, that would sum up winter 16/17.