Model output discussion - The Hunt For Cold

[Guest]

Just now, Tim Bland said:

Gfs I love you ..all is forgiven

 

Is that what we would call a cross polar flow ?

[feb1991blizzard]

Clusters very decent at T300,  the second 2 (total  around 45%) build tremendous heights to the NE / N respectively.

All goes downhill after that though.

 

Edited November 10, 2018 by feb1991blizzard

[Tim Bland]

1 minute ago, More Snow said:

Is that what we would call a cross polar flow ?

Almost! It’s a long way back to zonal from there!

[blizzard81]

You can always rely on the gfs 06z lol

[feb1991blizzard]

1 minute ago, blizzard81 said:

You can always rely on the gfs 06z lol

hopefully for accuracy as well just for once - please.

[Methuselah]

Not a bad finish...Screaming potential!

[Guest]

1 minute ago, Ed Stone said:

Not a bad finish...Screaming potential!

Just need it to hold off for about 5 days to allow me to move to my new house. 

[Leo97t]

Shown in the unreliable 

[feb1991blizzard]

To sum up - i think we are pretty sure now of this being the pattern a t around D10.

Its where we go afterwards, can we get a retrogression (GFS 6z op) or some sort of undercut maintaining the pattern somehow, in my mind its about 75-25 against a proper Northern block with deep cold arriving at our shores -  CAVEAT - im only talking up to around half way into Week 3 though, not saying we are going to have a rampant zonal pattern setting up and ruining December.

[Derecho]

8 minutes ago, feb1991blizzard said:

To sum up - i think we are pretty sure now of this being the pattern a t around D10.

Its where we go afterwards, can we get a retrogression (GFS 6z op) or some sort of undercut maintaining the pattern somehow, in my mind its about 75-25 against a proper Northern block with deep cold arriving at our shores -  CAVEAT - im only talking up to around half way into Week 3 though, not saying we are going to have a rampant zonal pattern setting up and ruining December.

Yes and a quite eye catching run from the GFS 06z. Just look at the NH view by the end!

 WAA to this degree would have a long lasting impact you would think

I do believe that the Scandi high is the more likely option, even the 00z ensemble suite contained plenty of them. Also to note is that almost all ensemble members have below average SLP over the Azores region. Good signs IMO.

Though November has been mild so far, it has been anything but zonal with the jet being remarkably quiet with low pressure systems getting stuck in the same places for extended periods of time. Just so happens that the UK in the last week has been in the wrong place! and the US in the right place (again)....

Anyhow here are some highlights from the 06z ensembles:

       

 

Not all of these are cold but they have potential further down the line. ECM doesn't look too bad either if the low can go underneath the block

Overall my hunch is that there will be a very mild week coming up but settling down towards the end of it and a more anticyclonic second half of November coming up, can we get an early taste of winter or will it remain mild?

[bluearmy]

Amongst the search for blocking, the trop vortex is progged to move energy Asia to Canada but the Asian centre remains stronger in the longer term ... 

[feb1991blizzard]

^^

Yes noticed that, i do actually think that if we were to achieve conducive Northern blocking within the next 30 days, looks like me it will come to the North, you can see it on the GEFS D16 ensemble mean.

[SLEETY]

I don’t know if i’m keen on wonderful cold synoptics in November.I have seen it before and the following winters have been pretty average at best.Not all of them of course ,would have to check the archives to see what November was like preceding bitterly cold winters or spells of bitter weather in the winter months

Much prefer seeing it towards end of Dec,to give ourselves a   good chance of a decent cold spell in January 2019.

It been a while January,just saying......

 

[bluearmy]

1 minute ago, SLEETY said:

I don’t know if i’m keen on wonderful cold synoptics in November.I have seen it before and the following winters have been pretty average at best.Not all of them of course ,would have to check the archives to see what November was like preceding bitterly cold winters or spells of bitter weather in the winter months

Much prefer seeing it towards end of Dec,to give ourselves a   good chance of a decent cold spell in January 2019.

It been a while January,just saying......

 

Personally not looking for cold sypnotics for a couple weeks yet - looking for sypnotics that keeps pumping waves into the polar field ..... each day takes us closer to proper winter ...... late November is very capable of delivering proper countrywide snowfall 

[Methuselah]

4 minutes ago, SLEETY said:

I don’t know if i’m keen on wonderful cold synoptics in November.I have seen it before and the following winters have been pretty average at best.Not all of them of course ,would have to check the archives to see what November was like preceding bitterly cold winters or spells of bitter weather in the winter months

Much prefer seeing it towards end of Dec,to give ourselves a   good chance of a decent cold spell in January 2019.

It been a while January,just saying......

TBH Sleety, I can't find any evidence that warm, cold or indifferent Octobers/Novembers have the slightest impact on the following winters...Not saying that that's the case globally, just that NH weather patterns might not be too dependent on what this wee pinprick of an island experiences, through October and November...?

[BLAST FROM THE PAST]

28 minutes ago, SLEETY said:

I don’t know if i’m keen on wonderful cold synoptics in November.I have seen it before and the following winters have been pretty average at best.Not all of them of course ,would have to check the archives to see what November was like preceding bitterly cold winters or spells of bitter weather in the winter months

Much prefer seeing it towards end of Dec,to give ourselves a   good chance of a decent cold spell in January 2019.

It been a while January,just saying......

 

In a way I agree...but that agreement refers to having cold blocking right now onwards.  Setups like that with super early nirvana Synoptics tend to extend into December but quickly run out of steam.  Blue makes a good point, in situations like this we keep going with waves pumping into polar field and a quick switch can and does happen, and the pattern can lead to prolonged cold reloading set up with a buckled meridional jet and northern blocking...so even with zonal attacks they become blips in the rhythm and the theme remains on the cold side.

Anyway 06z keeps the hunt for cold very targeted and others not without interest either

 

BFTP

Edited November 10, 2018 by BLAST FROM THE PAST

[damianslaw]

31 minutes ago, SLEETY said:

I don’t know if i’m keen on wonderful cold synoptics in November.I have seen it before and the following winters have been pretty average at best.Not all of them of course ,would have to check the archives to see what November was like preceding bitterly cold winters or spells of bitter weather in the winter months

Much prefer seeing it towards end of Dec,to give ourselves a   good chance of a decent cold spell in January 2019.

It been a while January,just saying......

 

A feature of recent cold winters, has been the propensity for a fairly quiet non-atlantic dominated late Nov/early Dec period, with cold sometimes very cold conditions and early taste of winter - 2005, 2008, 2010, 2012 and 2017 all produced some wintry conditions to various degrees and lots of high pressure last week Nov and first 10 days of December - 2010 most notably.. it is the time of year when the atlantic on average is at its most bullish, and when westerlies are most likely, so I believe it is a good sign if we see a quite atlantic at such a time.

However, 2006 also did this, but then went atlantic dominated by second week of December.

2009 was different, but the atlantic was behaving oddly then.

The met office forecast continues to suggest a cold blocked end to Nov and into Dec, reading between the lines it suggest the jet will go under the block.

We shall see - but if the GFS 6z synoptics of today verify then certainly this would tie in with the met office forecast - scandi high retrogressing NW in time, with split jet and energy going underneath.

In the meantime a very mild 10 days ahead - non-descript conditions, very benign.

 

[I remember Atlantic 252]

Always think when the Atlantic is at it's most bullish is late Dec to late Jan, as you say Damian atlantic can be quiet late Nov

[damianslaw]

In recent years it has certainly been the case that our most unsettled weather has tended to occur from late Dec and through January. However, by then in theory high pressure over the continent or to the north should have a greater potency about it in terms of embedded dense cold air pooling and therefore probability of beating the atlantic increases markedly, whereas in late Nov/early Dec such dense cold air pooling is less likely and the atlantic has an easier time of fighting off high pressure.

 

 

[Man With Beard]

1 hour ago, feb1991blizzard said:

To sum up - i think we are pretty sure now of this being the pattern a t around D10.

Its where we go afterwards, can we get a retrogression (GFS 6z op) or some sort of undercut maintaining the pattern somehow, in my mind its about 75-25 against a proper Northern block with deep cold arriving at our shores -  CAVEAT - im only talking up to around half way into Week 3 though, not saying we are going to have a rampant zonal pattern setting up and ruining December.

For winter in November, this is a pretty good starting point - at least it gives us a chance. 

I feel November is a good opportunity to get something out of a Scandi High before the PV cranks up, though it does need to be a perfect set-up for this high to bring wintry conditions at this time of year. 

But every recent year where we've seen a Scandi High in November, we've not seen one again until late January at the earliest. Make the most of it! 

[feb1991blizzard]

4 minutes ago, Man With Beard said:

For winter in November, this is a pretty good starting point - at least it gives us a chance. 

I feel November is a good opportunity to get something out of a Scandi High before the PV cranks up, though it does need to be a perfect set-up for this high to bring wintry conditions at this time of year. 

But every recent year where we've seen a Scandi High in November, we've not seen one again until late January at the earliest. Make the most of it! 

And to add to that, the ones that we have seen in Nov, usually hasnt had any cold uppers so has delivered Nothing.

Edited November 10, 2018 by feb1991blizzard

[Cheshire Freeze]

9 minutes ago, Man With Beard said:

But every recent year where we've seen a Scandi High in November, we've not seen one again until late January at the earliest. Make the most of it! 

Fine with that, as long as it's a Greenland HP as the alternative.

Edited November 10, 2018 by CreweCold

[Methuselah]

40 minutes ago, damianslaw said:

In recent years it has certainly been the case that our most unsettled weather has tended to occur from late Dec and through January. However, by then in theory high pressure over the continent or to the north should have a greater potency about it in terms of embedded dense cold air pooling and therefore probability of beating the atlantic increases markedly, whereas in late Nov/early Dec such dense cold air pooling is less likely and the atlantic has an easier time of fighting off high pressure.

Is that a trend, damianslaw, or is it down to 'random' fluctuation? 1962, '68, 69 and '70 all had cold and snow, at some time, during the period spanning late December to early January...At the time, I thought I'd found a trend. Now though, I can see that I hadn't.

[Snowy L]

38 minutes ago, damianslaw said:

In recent years it has certainly been the case that our most unsettled weather has tended to occur from late Dec and through January. However, by then in theory high pressure over the continent or to the north should have a greater potency about it in terms of embedded dense cold air pooling and therefore probability of beating the atlantic increases markedly, whereas in late Nov/early Dec such dense cold air pooling is less likely and the atlantic has an easier time of fighting off high pressure.

 

 

Thats common anyway and happens even more when at solar maximum and declining from solar maximum, as seen in 4 of the last 5 winters. We are pretty much at solar minimum now, solar flux has been at background or close to background levels so hopefully we should be seeing more winters where the Atlantic isnt completely dominant in early winter. We saw a bit of that last winter. As for the cold in November argument, we are at least 2 weeks away from seeing a potential cold block. That brings us into the end of November and by then if you get a cold block in place it will defiitely be cold enough for low level snow. I have no problem with us getting these synoptics now. Im just happy the cold block didnt happen in October/early November as that definitely would have been a waste.

[Man With Beard]

1 hour ago, feb1991blizzard said:

And to add to that, the ones that we have seen in Nov, usually hasnt had any cold uppers so has delivered Nothing.

Yes the idea of Scandi High bringing cold weather in November is a theoretical one - bit like the "beast from the east" which had lived in the "theoretical" box since 1991 until earlier this year - it is easy to see how it could work for cold, but because everything has to work right, it's not seen often. 

Basically, we're looking for some sort of cold pool to get in underneath the Scandi High shortly after 20th November (many runs are showing this), then drift slowly towards the UK over the course of a few days giving it time to cool over the continent (some runs are showing this), and then phase with a disrupted front from the Atlantic with the UK on the north side (not easy to achieve perfectly), perhaps around 23rd/24th.

No reason why it couldn't happen... but all steps need to be followed fairly optimally, or there's still enough mild air at this time of year to reduce its potency. In recent years, we've got very close but not quite. 

Edited November 10, 2018 by Man With Beard