Great 06z OP, with a potential N/NE blast setting in after the initial Easterly. Certainly a new trend to watch out for.

I noticed the 552 getting into southern Greenland by T207 as well:

http://www.theweatheroutlook.com/twodata/chart.aspx?chart=/charts/gfs/06_207_mslp500.png?cb=39

Plenty to keep me interested.

seems to be an even split in the GEFS between those that want to raise heights in the Greenland/Iceland region and those that bring back the atlantic

fortunately the op and control are in the cold camp

seems to be an even split in the GEFS between those that want to raise heights in the Greenland/Iceland region and those that bring back the atlantic

 

The GFS always wants to bring back the atlantic.   Takes aloft of evidential data to get any members swayed towards a GH scenario.  Read between the lines as you wish

http://modeles7.meteociel.fr/modeles/gens/runs/2017011306/gensnh-0-0-264.png

Exceptional warmth across the NE of America, which is helpful in keeping the atlantic quieter

I posted yesterday that i was worried about the potential cold easterly spell being shortened  by a squeeze at both ends.

Todays meto forecast has a statement that colder air may get into the SE on Tuesday.

Presumably that is based on the 84h fax shown below which shows a cold front beginning to track west in the south but a warm front continuing to move east in the north.Looking at GFS ,ECM and GEFS it looks like the 17th/18th by the time an easterly flow is establishes.At the other end the easterly seems to collapse by Saturday/ Sunday so we are looking at a 3/4 day easterly.

Of course there maybe wintry possibilities in the breakdown Iceland/GH and even more snow opportunities However by 240h there are also zonal ENS starting to appear.

 

 

 

 

 

We are coming up to the period where there was a lot of discussion re: GFS vs ECM outcomes which were very different. All the models, particularly GFS, predicted this current cold outbreak very well. In fact the most unusual thing was how much more snow there was in the East and South/South East, not forecast by anyone. It yet again proved the futility in trying to look at snow predictions more than a couple of days out whoever is saying it. So soon we will see if we get the (then) forecast GFS NW/W dominated HP across the UK next week or the ECM (then) forecast Easterly. I suspect it will be something with an easterly element, but not quite how ECM envisaged it then.

GFS 06z ens

Wah! Uppers for even Plymouth going to-10 for a couple of days on the op!

Mind you it looks a bit out on a limb also the snow row is but 3!

 

 

I wonder what synoptics they are showing? The high would have to sink a LOT from the op run to let mild air over the top into Holland, ao that seems puzzling.

Looking at wind direction, there is now a significant cluster showing a quick transition to first southerlies and then SWerlies. 

The GFS ENS 850 plots are not telling the whole story and it is easy to interpret the upward swing in uppers in FI as 'mild and Atlantic-driven'.

http://www.wetterzentrale.de/pics/MT8_London_ens.png

Taking 27/1 deep into FI on the Op for example, the 850s are high, but this is due to a southerly pumping up a blocking high to the north-east. Conditions at the surface are far from mild and we see a southerly-tracking jet.

http://old.wetterzentrale.de/pics/Rtavn3481.gif

http://old.wetterzentrale.de/pics/Rtavn34817.gif

http://old.wetterzentrale.de/pics/Rtavn34815.gif

In short, high 850s do not necessarily equate to a mild outcome.  

 

We are coming up to the period where there was a lot of discussion re: GFS vs ECM outcomes which were very different. All the models, particularly GFS, predicted this current cold outbreak very well. In fact the most unusual thing was how much more snow there was in the East and South/South East, not forecast by anyone. It yet again proved the futility in trying to look at snow predictions more than a couple of days out whoever is saying it. So soon we will see if we get the (then) forecast GFS NW/W dominated HP across the UK next week or the ECM (then) forecast Easterly. I suspect it will be something with an easterly element, but not quite how ECM envisaged it then.

Really?  My recollection is that ECM picked up the northerly and sustained it whilst GFS had the high flattening to the west as early as tomorrow.  As for the easterly/south-easterly flow next week, GFS didn't show that at all for several days after ECM picked it up.

Your point about precipitation is well made.  I posted in the other thread that this morning's snow wasn't correctly predicted even by the 06z, i.e. it was wrong at 3-4 hours out.  Actually the trough was far more active than even the Met Office were expecting as recently as last night, with a larger area of precipitation extending further west than expected.

Meanwhile, here's the 00z ECM ensemble for London:

Still the same trend to less cold in the 10-15 day period but less marked that in yesterday's 12z.  I commented last night that it seemed it was around uncertainties over the possible repositioning of the block or its demise.  It's only a guess but I wonder if more perturbations are showing the block moving towards the north Atlantic - as hinted at in several operational runs recently (and this morning's GFS).

Probably the kiss of death but worth remembering that, if you look at historical charts, in most sustained cold periods there are switches in pattern that must have looked at the time like an imminent breakdown. 

http://modeles7.meteociel.fr/modeles/gens/runs/2017011306/gensnh-0-0-264.png

Exceptional warmth across the NE of America, which is helpful in keeping the atlantic quieter

 

This means colder here then.

 

This means colder here then.

Potentially - at least cyclogenesis off Newfoundland is switched off. The Atlantic jetstream is also switched off. But whether that means cold for us, is as ever in the lap of the gods. It might mean a continuation of boring nothingness. It all depends on the precise location of any resulting HP cells

Outstanding evolution GFS 6z and ECM 0z op in the 7-10 days range that previously would have generated considerable excitement with an abundance of snow and ice emoticons.

However, despite the recent taste of winter (and for most its little more than that), I think there's more spectism, cynicism even, than normal after repeated backtracking by the models showing the more wintry charts (though it was GFS showing the quick breakdown a few days back that backed down so it's not all one way).

It would be really interesting to see, if averaged out, whether the 240h charts are significantly more wintry than 0h charts or whether that's just a perceptual illusion. This winter, in particular, it feels that if we live at 240h then we'd be in the middle of an historic winter!

the ens days 11/15 are all pointing to a renewed atlantic trough (very low amoloy on the eps)  and higher heights returning to our south and southeast. if this is not going to happen then it will take the ops to head on a different track days 7/10 which the ens will then follow. as an example, the MLB next week was not picked by the ens but by the ecm op (which over did the latitude as it generally does). so we have a block next week when the extended ens originally pointed to a mean trough just to our east.  

the general rule is that the op follows the ens in that time period but I find that if ecm op is consistently going in one direction against its mean anomaly in the 7/10 day period then it should be taken notice of. at the moment the output days 7/10 seems pretty good between the op and the ens. if the esn are consistent then that souwesterly flow should come into view soon. if the ecm op continues to keep high heights close to our nw then we could be looking at extending the cold. the ens say that these heights will retrogress to a Canada and allow the atlantic to push through. interesting weekend approaching

 

Really?  My recollection is that ECM picked up the northerly and sustained it whilst GFS had the high flattening to the west as early as tomorrow.  As for the easterly/south-easterly flow next week, GFS didn't show that at all for several days after ECM picked it up.

Your point about precipitation is well made.  I posted in the other thread that this morning's snow wasn't correctly predicted even by the 06z, i.e. it was wrong at 3-4 hours out.  Actually the trough was far more active than even the Met Office were expecting as recently as last night, with a larger area of precipitation extending further west than expected.

 

I was only referring to accuracy for this current short cold snap - but it has flattened by tomorrow hasn't it. At 18z Sat on the latest run shows air coming up from Azores, SW, then West and coming across England on a NW'lie drift only from N.I./Scotland. It never showed low pressure zonality.  Unless it changes by tomorrow there is no sustained northerly. Of course your point about the Easterly is true, although that is in the future but with more agreement so hopefully will happen as per ECM :-)

---

S.Essex, 42m ASL

GFS 06Z at 216 hours - http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=216&mode=0

not a million miles away from ECM 0z http://www.meteociel.fr/modeles/ecmwf.php?ech=216&mode=1&map=0&type=0&archive=0

(I know the hours don't compare exactly - my bad)

 

What I like about both those charts is the string of lows extending from Newfoundland through Gibraltar as far as Italy. They were there on the 12z ECM op last night too, acting as a sort of foundation or barrier for high pressure to build further north.

If nickl is correct in his view that we're going to have to look to the operational runs rather than the ensembles for continued blocking, then this might be the key. It could be that this kind of string of troughs to our south is generally too weak to be picked up by low-resolution ensemble runs. (Not wishing to put words in nickl's mouth - he knows this game way better than I do.)

 

 

The GFS always wants to bring back the atlantic.   Takes aloft of evidential data to get any members swayed towards a GH scenario.  Read between the lines as you wish

As I recall, GFS wanted to bring the atlantic back in by the end of the coming weekend, according to a number of operational runs last weekend and the start of this week. They also showed the HP presently to the west of thw UK sinking south towards Iberia with more unsettled weather returning to the north-west of the UK.

Good afternoon

What time do the fax charts get updated?

Thanks

 

As I recall, GFS wanted to bring the atlantic back in by the end of the coming weekend, according to a number of operational runs last weekend and the start of this week. They also showed the HP presently to the west of thw UK sinking south towards Iberia with more unsettled weather returning to the north-west of the UK.

It didn't - not the majority in the ensembles. I commented on them at the time. It showed exactly what it does now till Monday. A westerly ish flow around a sinking HP. It then showed total uncertainty but no defined Easterly in its operational runs as per ECM, and it has now changed and drifted towards that. This "bring the Atlantic back" seems to be a misused phrase when someone suggests the flow is from the West whereas I alway see it as inferring low pressure systems returning, which it never did.