+225 the Greenland HP builds again!!

 

Up to 1050mb  over Greenland now by T +237 and 1055mb by +240z:

 

 

---

GFS 18z = absolute snowfest for many northern areas, especially with altitude. 

Not a clean cold easterly, but the outlook is still cold, and somewhere is going to get a lot of snow within the next two weeks. 

---

GFS 18z = absolute snowfest for many northern areas, especially with altitude. 

Not a clean cold easterly, but the outlook is still cold, and somewhere is going to get a lot of snow within the next two weeks. 

Yes! - not clear cut prolonged cold but more snowier at least if this does come about certainly seems like it esp for the north! Ski resorts in Scotland will be well chuffed!! 

---

the diving jet driving repeated lows of varying cold reminds me of the winter in the early 80s (poss '83), which had frequent short lived cold snaps with some giving a decent dump of snow. I lived in Manchester back then, as a student, and had some good snow ball fights in the street in front of our student let house in Chorlton-cum-hardy. 

Looks like we may get many a marginal might-be, might-not events. I think Monday night's 

---

Forgot to finish, but Monday night's / Tuesdays front should occlude over Eastern England and leave some wet snow, the mid section of which might dump something better, via evaporative cooling.

---

I think Monday night's 

?

Well?

I just saw the week ahead by Chris Fawkes and shows rain moving southwards as rain but snow to the near continent...!? But the models show the rain turning to snow!? Seems like there is a lot of uncertainty in the potential rain to snow event tomorrow night!?

---

I always wonder why the models show rain over the UK turning to snow as soon as it reaches France even though the 850s are higher there. Presumably altitude has something to do with it but is northern France really that much higher than southern England?

---

N

The cold was always forecast for the middle January onwards, as is highlighted in the extended outlook from the 1st of January

“UK Outlook for Wednesday 16 Jan 2019 to Wednesday 30 Jan 2019:

It is likely start unsettled across most areas at first, with perhaps heavy rain and gales at times, especially in the north, where severe gales are possible. Hill snow is also possible, as well as snow to lower levels at times in the north. By the third week of January there is then an increased likelihood of a change to much colder weather generally, bringing an enhanced risk of frost, fog and snow. These conditions may then continue to the end of the month, but some milder, wet and windy interludes also remain possible throughout this period.”

Considering the timescale and model uncertainty that was a pretty good call (including the low level snow there has been in parts of the north).

 

Well not quite. At the beginning of January it was forecast for the middle of Jan. In the middle of December it was forecast for the beginning of Jan. And at the beginning of December it was forecast for the second half of December. 

With all these delays and cancellations I’m beginning to suspect that the franchise for the Siberian Express has been taken over by Southern Rail. 

---

I always wonder why the models show rain over the UK turning to snow as soon as it reaches France even though the 850s are higher there. Presumably altitude has something to do with it but is northern France really that much higher than southern England?

Maybe lower surface temps are negating the higher 850s somewhat? (haven't a clue what temps are in north France tbh.)

---

I always wonder why the models show rain over the UK turning to snow as soon as it reaches France even though the 850s are higher there. Presumably altitude has something to do with it but is northern France really that much higher than southern England?

lower Dp's due to slightly more continental influence perhaps?

 

Maybe lower surface temps are negating the higher 850s somewhat? (haven't a clue what temps are in north France tbh.)

Based on the GFS 18z the 850s are the same or marginally lower in northern France - the surface temperatures are definitely lower.

As it’s looking marginal for central and south-eastern parts it doesn’t take much to swing from rain and sleet with back edge snow here to sleet and snow across the Channel.

---

I always wonder why the models show rain over the UK turning to snow as soon as it reaches France even though the 850s are higher there. Presumably altitude has something to do with it but is northern France really that much higher than southern England?

 

It's to do with BREXIT - it's clearly the reason why! EVEN THE WEATHER is punishing us!!

---

I always wonder why the models show rain over the UK turning to snow as soon as it reaches France even though the 850s are higher there. Presumably altitude has something to do with it but is northern France really that much higher than southern England?

It isn't really - and in a scenario like this it'll have onshore winds too, whereas Kent (for example) won't. The only thing I can think of is that there's a deeper layer of cold air in situ compared to the UK, that and the front's occluding all the while. It's amazing how often it happens though!

The Euro4 and UKV are both most reluctant to show snow from the front down here, albeit UKV does squeeze out a solitary sleet symbol here tomorrow morning. GFS has snow, but when looking at the hourly forecasts it's only a tiny bit (0.2mm worth) after the rain (6mm).

As a point of note ....only 2 out 3 ssw's deliver a colder than average setup....

And this looks likely to be one - all the anomaly charts show colder than average conditions for the UK over the next couple of weeks, with only this weekend seeing an above-average blip.

---

This is proving to be the most frustrating winter ever - the nearly winter. What has gone wrong? After all, there was a major SSW.

Bad luck! The PV was split but we have been exceedingly unlucky in that a potent chunk of the vortex ended up in the worst possible place for the UK - NE Canada - this is spitting out its cold into the north Atlantic firing up shortwaves which are destroying any chances of HLB blocking becoming established over Greenland and Iceland. Our winter stays at day ten in the charts, since low res is failing to pick up these nasty little spoiler lows. Without that Canada vortex, I am pretty sure some HLB would have become established by now.

So here is the question - why does the vortex so like the worst possible region for UK winter? Why doesn't it prefer to set up home in Aleutia or Siberia? It is because of the vortex of doom setting up across the Pond that we lose out, even when other things being equal, we have a favourable setup.

Instead of the northern blocking we need, instead we end up with NW -> SE flow which keeps things cool and no doubt is nice for northern upland regions, but is complete pants for where the majority of the population of UK and Ireland live.

---

This is proving to be the most frustrating winter ever - the nearly winter. What has gone wrong? After all, there was a major SSW.

Bad luck! The PV was split but we have been exceedingly unlucky in that a potent chunk of the vortex ended up in the worst possible place for the UK - NE Canada - this is spitting out its cold into the north Atlantic firing up shortwaves which are destroying any chances of HLB blocking becoming established over Greenland and Iceland. Our winter stays at day ten in the charts, since low res is failing to pick up these nasty little spoiler lows. Without that Canada vortex, I am pretty sure some HLB would have become established by now.

So here is the question - why does the vortex so like the worst possible region for UK winter? Why doesn't it prefer to set up home in Aleutia or Siberia? It is because of the vortex of doom setting up across the Pond that we lose out, even when other things being equal, we have a favourable setup.

Instead of the northern blocking we need, instead we end up with NW -> SE flow which keeps things cool and no doubt is nice for northern upland regions, but is complete pants for where the majority of the population of UK and Ireland live.

Gavs video a few days ago showed NW Europe below average for a at least two weeks - starting at the end of Feb , isn't the EC46 out tonight? be interesting to see what's going on with that .

Have to say 'if' we get nothing this Winter my interest in LRF's will have gone and will show what I have thought for a long time they are purely guess work and that no one or any super computer for that matter  can predict what the atmosphere can and will do . 

---

 

lower Dp's due to slightly more continental influence perhaps?

Agreed. The winds immediately in front of the rain/snow band will be off the channel in the UK. We need the front to stall so that’s its the conditions behind the front that cause the snow, not those in front of it. 

Jeff

---

This is proving to be the most frustrating winter ever - the nearly winter. What has gone wrong? After all, there was a major SSW.

Bad luck! The PV was split but we have been exceedingly unlucky in that a potent chunk of the vortex ended up in the worst possible place for the UK - NE Canada - this is spitting out its cold into the north Atlantic firing up shortwaves which are destroying any chances of HLB blocking becoming established over Greenland and Iceland. Our winter stays at day ten in the charts, since low res is failing to pick up these nasty little spoiler lows. Without that Canada vortex, I am pretty sure some HLB would have become established by now.

So here is the question - why does the vortex so like the worst possible region for UK winter? Why doesn't it prefer to set up home in Aleutia or Siberia? It is because of the vortex of doom setting up across the Pond that we lose out, even when other things being equal, we have a favourable setup.

Instead of the northern blocking we need, instead we end up with NW -> SE flow which keeps things cool and no doubt is nice for northern upland regions, but is complete pants for where the majority of the population of UK and Ireland live.

My recollection from the MetO information is that although things are returning to normal higher up now, the trop response was not due until about now and was due to continue to be disrupted all through February and perhaps beyond? Or maybe that's changed now?

---

This is proving to be the most frustrating winter ever - the nearly winter. What has gone wrong? After all, there was a major SSW.

Bad luck! The PV was split but we have been exceedingly unlucky in that a potent chunk of the vortex ended up in the worst possible place for the UK - NE Canada - this is spitting out its cold into the north Atlantic firing up shortwaves which are destroying any chances of HLB blocking becoming established over Greenland and Iceland. Our winter stays at day ten in the charts, since low res is failing to pick up these nasty little spoiler lows. Without that Canada vortex, I am pretty sure some HLB would have become established by now.

So here is the question - why does the vortex so like the worst possible region for UK winter? Why doesn't it prefer to set up home in Aleutia or Siberia? It is because of the vortex of doom setting up across the Pond that we lose out, even when other things being equal, we have a favourable setup.

Instead of the northern blocking we need, instead we end up with NW -> SE flow which keeps things cool and no doubt is nice for northern upland regions, but is complete pants for where the majority of the population of UK and Ireland live.

I appreciate the frustration but what jumped out for me was the fact that there are several SSWs every decade. Obviously we don’t get extended periods of freezing weather several times every decade so it’s not a simple correlation.

We all understand that the atmosphere is complex and often volatile and the synoptic patterns are influenced by many factors. A SSW only tilts the odds, in the same way that a solar minimum tilts the odds.

Finally, having a chunk of the polar vortex over NE Canada doesn’t guarantee cyclogenesis and it doesn’t guarantee that LPs will track across the Atlantic. Again there are other factors, especially the jet stream.

 

---

The nice thing with last year’s beast was that we could enjoy the pattern while knowing that if it recurred in summer the weather would be hot and dry (and so it was).

The next 2 weeks though... if that recurred in June it’d be 2007 or 2012 all over again. Please let it not be a trend.

---

It's a little like the early 00s when Benfield Hazzard and the Met were touting the May N Atlantic SST profile. Despite what anyone else may say, that correlation has proved to be of limited value. I think SSWs will also come to be seen as a very blunt forecasting tool too. 

---