chionomaniac

I know this is ECM day 10, but I see this as reinforcement of the Greenland block. Maybe a bit west based but maybe not.just a nice trend for continuation of colder Synoptics.

I saw an earlier indication that the ECM was suggesting repeating anticyclonic Atlantic wave breaks. And the one at T+240 wasn’t too west based. Good to see the gfs following suite. Reinforcement of the Atlantic block will give us far better opportunities at delivering longer and colder synoptic results. brings us far greater chances even further south

Lol. No comparison to a lot of cold rain and sleet

Some pretty chilly runs this morning. Lets reel them in! (3rd ECM on the trot showing some form of Greenland block too) That last third of January signal has been consistent.

It’s certainly a consideration, but only that at this point. Far too far away atm to be any more than that Kasim.

18ZGFS is just another variation on the same pattern. No more no less. When the pattern completely changes then be concerned.

That to me is the more precise trop Synoptics following the disruption that is more difficult to be sure of. Hence one can say that blocking around Greenland is likely, but the southward extent of cold air on its eastward flank is impossible to predict. As in the last spell, I look at the 500hPa pattern first, then look at the surface level Synoptics closer to the time. For those who have had days of cold rain, from the last synoptic pattern have been really really unluckly. Same as being 1 number out with all your lottery numbers, or the scratch card after yours hits the jackpot. It happens. No point in looking back, or assuming that will happen again.

I, of course would like to see two means. One with significant strat events included, and one with them excluded. It is the one with them excluded that is the real strat vortex that dominates the trop.

I consider the vortex as being weak for the foreseeable. Remember the mean takes into consideration the number of vortex events that have occurred over a period of time that will adversely affect the troposphere. If we remove these then average is probably closer to 30m/s, leaving strong at 40m/s. It is the strong strat vortex that definitely dominates the trop. Anything less than that then the trop is not necessarily overridden. And that is before the strat intensification can downwell. And there is a strong possibility of further weakening from above to. All good.

Just to add this winter we have seen a situation where there has been a disconnect during December between strat and trop, with trop wave patterns dictating the trop patterns. This has already led to the cold spell that we have experienced. Just as it looks like the trop disconnect is about to wane the feedback from the trop stationary waves has led to a SSW. This SSW is now dictating the state of play for the near future, and the feedback to the trop from this is now assisting the upcoming trop pattern. Add in the continued strat disruption and if we don’t get a significant severe cold spell, then we never will!

Great to see 2 ECM runs on the trot showing Greenland blocks. No way is this decided yet, like a good battle with a large fish, we need to see it reel in. Normally I am very wary of a displacement SSW in respect of trop blocking responses. Less so this one though, it appears that the Atlantic amplification response is a feedback from Atmospheric feedback from the SSW, which leads to a weak northern polar jet and strengthened southern jet. And the upper strat disruption looks to being continued, rather than a strong reintensification of the vortex. All potentially great news for even longer term prospects. L all levels of the strat look weak. Its been quite a few years since we have seen such an alignment of factors whether or not the atmosphere turns more La Niña. This may not matter a jot now. Still excited about the last third of the month.

Hi Mushy, If you average the flow out over 6 days and then place as 500hPA mean heights then there can be quite large differences between the 6 day 500hPA mean flow and the surface flows during that period. Th0se means were never meant to be read like that. The pressure anomalies are more important when working out likely stearing upper and surface flows as Kirkcaldy showed.

Early days with the 06GFS, but I think I can see better angle on the close trough and better amplification out west. Nothing is ever nailed on until the snow has settled on the ground.

Looks like the Atlantic amplification is heading towards a potent NEasterly if it doesn’t collapse too quickly

I can’t believe I’ve read 5 pages of weather there will be a Greenland high or not. With the propagation of the SSW, we have certainly seen an early divergence in the trop modelling. And this we have seen many times before has led one or more models down a garden path. Initially it looks that any Greenland high in the next ten days is unlikely, but with a resurgence of negative winds at the top of the strat, I wouldn’t discount this for too long. In a superstitious way, I wouldn’t rule it out either. The number of times I have seen Steve rule a scenario out and then see the models reverse within 24 hours are too numerous to mention. So I’m happy with that too.

I reckon they post the expected possible maximum temps that may be experienced in the centre of the biggest cities. So heavily biased towards urban heat islands and not considering the temps experienced in rural areas. It gives a heavily skewed forecast not at all focussed on those who don’t live in the middle of an urban heat island.

Hope so. At the moment my snow depth photos are more snow death photos! And Im sure I can bring a pud or two along to the barbie.....

Yep. Me too. Looks like an uptick in tropical AAM tendency which will hopefully reinforce the mid latitude and high latitude blocking pattern. Last third of the month is looking very promising for us here. Probably from the NE. I am getting as confident as I was ten years ago. When all models lead to cold at day ten then it is normally the route taken that needs to be decided, rather than the destination. Say hello to Lou and the girls from me.

Lol. Perhaps I better not post for a few days. But I haven’t seen such a strong signal for proper cold in a long while. We have strat, a small amount of tropical feedback reinforcing an excellent underlying early winter pattern. The solar cycle of early ascending phase seems to reinforce these blocking patterns too. Why? I’m unsure of. But all in all, let’s stay calm and see how this unfolds, because we have already experienced fantastic synoptic output this winter for very little surface gain. Unless you have altitude and distance away from coastal modification on your side. But that may change in the last third of January.

Has there ever been a run in history that has followed the later GFS footsteps. Probably not. It’s the early changes that are important

So firstly, low behold, we have that stronger Greenland block on show. All routes lead to.... But why am I so confident so early on that this will be the case? Well it is the difference between thes two charts, one from the 12ZGFS run and the next from the 18ZGFS run. If we we know the destination, then we can pick the better route early on. The above chart is the 18z the below chart the 12z. Not much difference at the same timeframe. But the big difference here at an early timeframe is seen towards the southwest of Greenland. The way the low pressure splits from the main lobe and the difference in heights involved is all important here. Once we see that, we know that reinforcement of any Greenland block is likely to be stronger and quicker in the median term. So so at this point, despite what happens in FI, we know that we are likely to see an Atlantic blockout and possibly some great northern Atlantic blocking

Lol this run could be heading towards a Friday evening pub run special brew. Let’s keep watching.

Interested here to see if my destination theory is right with the 18z gfs and/or parallel. Let’s see if the route ends up at a similar destination. If it doesn’t then I may look the fool short term, but not necessarily in the long run.

Stopped looking at ECM tonight at 168. It’s one of those times, that no matter what is modelled before day 10, I knew that T+240 would show a Greenland block scenario. And sure enough I just looked and the Atlantic amplification is there towards Greenland. Back in 2010, we knew the destination, but not the route there. I’m beginning to get that same nostalgic feeling again.......

In this run, I see the middle third struggling to work out how the end third will materialise. ...but we know that the end third is close to what we expect. Seen this before many years ago.