[Cold hunt - models and chat]

To be fair, I believe that in March 2018, the southwest got the most snow in both cold spells. 

[Cold hunt - models and chat]

I guess that the SSW in 2013, that took a while (3-4 weeks) to really affect the weather (March 2013), but when it did hit, we did know about it. So I personally think that goodies lie ahead, although I was hoping we would have had a cold spell by now.

[Model output discussion - cold proper on the way?]

Sort of think (hope) there might be a 'not so fast' story to today but we'll see.

[Model output discussion - 7th January onwards]

16 minutes ago, sorepaw1 said:

Anyone noticed the worried tone and seriousness in stavs video forecast .

Sorry, missed that on beeb, do you mean Stav sounding worried & serious about cold weather for UK next week? 

edit: seems that's what it is. 

We seem to be almost there, fingers crossed.

[Model output discussion - 7th January onwards]

Strange how the GFS para is being more dismissive about UK cold atm, I've noticed this winter it has tended to be biased the other way, but then, it has not verified.

[Model output discussion - 7th January onwards]

Hope it is OK to ask this - what is now the informed opinion about how well GFS is doing, what with the government shutdown?

Maybe it's performing perfectly alright I don't know.

[Model output discussion - 7th January onwards]

I believe the JMA long ranger was painting quite an extreme picture for February, with easterly winds all around the globe at say 50 degrees north. 

[Model output discussion - 7th January onwards]

Thanks for the info warrenb.

[Model output discussion - 7th January onwards]

9 minutes ago, warrenb said:

If the trop mirrors the strat then the lobe will go there, we basically have a 3 way split, but the two main lobes are over Eastern Europe (Hence the weather they are having) and over Canada (Hence the jet starting to fire up).

Hmmm that's a pity it's panned out like that.

Still, latest JMA looks good with strong GL HP. And CFS also. Makes you wonder how they're seeing it.

[Model output discussion - 7th January onwards]

But is it a certainty that a strong lobe of PV will end up over NE Canada? Surely it's too early to say for certain - Or maybe not? I'm not an expert.

[Model output discussion - 7th January onwards]

We want that high to punch up into NE Canada

[Hunt For Cold: Model Discussion - Heading Into Christmas]

Seriously though, might Fawkes be right even thought most of us hope he's wrong? Why would the SSW struggle to affect the troposphere? Of course SSW is not a silver bullet.

[Stratosphere and Polar Vortex Watch]

10 minutes ago, Catacol said:

Without it blocking in the right place is difficult (not impossible...) to get.

Really, so the majority of sustained UK cold spells are preceded by a SSW? Interesting. 

[Stratosphere and Polar Vortex Watch]

Thanks for the replies, i guess it was something of a silly question, but it's interesting that so much would hinge on this SSW.

But of course there's still the issue of whether the impending SSW will be powerful enough, occur in right place etc. I think, but I'm no expert?

Fingers crossed. 

[Stratosphere and Polar Vortex Watch]

I believe I recall Crewe Cold saying that he thought that the LRF models that are going for major HLB this winter are doing this predicated on a major mid winter SSW, and that without the SSW it will difficult to get any HLB at all this winter. Does anyone else agree with this assessment?

[The hunt for cold - Model discussion (late November)]

Gotta feeling we might just be slippy sliding our way into Bruegelian dreamland.....

[The hunt for cold - Model discussion (late November)]

I remember reading on the forums one or two times, something along the lines of 'cold spells can & do come out of nowhere'. I think it is true to some extent.

[The hunt for cold - Model discussion (late November)]

5 minutes ago, SLEETY said:

As if by magic the HLB which has been prevalent since SSW in late Feb has been replaced by low pressure to the North and high pressure to the South as we enter the winter months of D J F yet again.

Not sure that's correct, it has been very high pressure dominated since the SSW, but if you look the AO and NAO have been largely positive since then, I think the high pressure has been mostly over Europe (where we want it for summer) , rather than at higher latitudes. 

[The hunt for cold - Model discussion (late November)]

Yes as Steve Murr says, zonal wind forecast should cheer up us coldies:

[The hunt for cold - Model discussion (late November)]

Somebody here said that the BBC monthly forecast is quite bullish about mild SW winds early-mid Dec which is interesting in a way, although not good news for most of us. However latest JMA monthly for this period seems to have some HLB going on: 

 

Interesting (though somewhat worrying) what Crewe Cold said about the long range models going for cold UK winter being predicated on a SSW in mid-late Dec, and that without it HLB will be difficult to achieve. Fingers crossed it does happen !

[The hunt for cold - Model discussion (late November)]

Yes the CFS zonal wind forecasts have very adamant about what looks like a strat warming in Dec.

edit: oops just checked latest zonal wind forecasts and not so adamant this time. but looks alright.

[The hunt for cold - Model discussion (late November)]

21 minutes ago, DiagonalRedLine said:

We should all probably go into the Atlantic and stamp on that Low Pressure system in the models. Maybe then, it’ll become flat enough to slide neatly under the block and draw in lots of cold air from the East/North-East. 

 Oh my childhood fantasies.....

[The hunt for cold - Model discussion (late November)]

It's so great to see so little of the PV on the North American side of the pole in some of these charts - pretty sure haven't seen it like this since 2010. 

[Model output discussion - The Hunt For Cold]

I suppose really what this all boils down to is whether we get a proper/severe cold spell in the first half of December. I'm 50/50 about it I think. However I am optimistic long term by the fact that GLOSEA and JMA seem to be going for a very blocked winter, particuarly in the latter half. I think Crewe Cold said the other he thinks January is the month. So if December is not great I myself wouldn't be too despondent. 

[Model output discussion - The Hunt For Cold]

So good to see the NH perspective looking more like it did in 2009-10. Remember that in Dec 2010, the Greenie high did sometimes sink, but went north again as the atmosphere remained conducive to this.