Model discussion: Hunt for cold - into mid-January

[Cheshire Freeze]

8 minutes ago, Downburst said:

Just wondering though if the PV has been powered up way way above average? Certainly a massive anomaly over Northern America, but most areas over the pole are in positive 500 hPa territory. Perhaps I am misunderstanding this?

 

Clear to see there that the strong -ve anomaly is mirrored by that strong NE Pacific anomaly. It’s this that has scuppered us over recent times as that HP sends cold sweeping down through Canada and the N states. 

[mountain shadow]

15 minutes ago, Lukesluckybunch said:

UKMO not looking too bad at 144,hoping for heights to be building behind..doesnt seem to be any nasty looking lows

Given the depth of PV to the NE, there will be lows spawned to stop any ridge attempts.

[*Stormforce~beka*]

1 hour ago, Ed Stone said:

And here's the Met Office's latest 10-Day Forecast: 

 

Too scared to view that so I ain't gonna!

1 hour ago, Ed Stone said:

And here's the Met Office's latest 10-Day Forecast: 

 

Too scared to view that so I ain't gonna!

[Downburst]

Just so folks know the ECM site is free and you can look at 10 hPa weeklies and yes there is warming forecast mid to end month and intensifying, where this impacts, if at all we can't say. That's just a fact. It is not that simple I am afraid. 

 

[Downburst]

11 minutes ago, CreweCold said:

Clear to see there that the strong -ve anomaly is mirrored by that strong NE Pacific anomaly. It’s this that has scuppered us over recent times as that HP sends cold sweeping down through Canada and the N states. 

Exactly. And as we know this fits in with the data for Strong La Nina since 1950, the composite.

[damianslaw]

5 minutes ago, Downburst said:

Exactly. And as we know this fits in with the data for Strong La Nina since 1950, the composite.

One factor often included are SSTs in NE Pacific. These were colder than many a recent year start of season and thought might reduce chance of high pressure in that vicinity. Alas looks like the La Nina imprint has overridden them. Mind did we not have aleutian low heights early in the season. 

[Penrith Snow]

3 hours ago, SqueakheartLW said:

Don't think you could get a more organised vortex than that on GFS 06z

Then a closer look at Europe

What happened to Iceland and Greenland? They've fallen into a black hole

And another Greek Snowfall Special just to rub it in  

[Had Worse]

Just now, Penrith Snow said:

And another Greek Snowfall Special just to rub it in  

I think they call it  Meze.

[jules216]

A quick summary of GFS 12Z

[Catacol]

1 hour ago, Downburst said:

Just wondering though if the PV has been powered up way way above average? Certainly a massive anomaly over Northern America, but most areas over the pole are in positive 500 hPa territory. Perhaps I am misunderstanding this?

 

Stratospherically this current period is very strong - above the 90th percentile.

The stratospheric vortex has been above average all season, and while it has not downwelled sufficiently to create horrendous atlantic conditions for us, its strength has meant that high latitude blocking has been very hard to obtain. Looking at 500hpa anomaly charts won't really tell you the vortex story.

 

[Cambrian]

With its timing during the night hours, the little low pressure for early next Monday (by then thank goodness we’ll be getting right to the end of this relentlessly savage January), is shown with a bit more clarity on the 12z GFS operational run. 

It drags down some quite cold uppers, coinciding with the precipitation, and though at the moment limiting snow to higher ground in the north, might well in the event do better than currently advertised, especially inland. Worth keeping an eye on perhaps. 

108h

 

114h

  
 

A sneaky little snow half-chance maybe, but needs must…

 

 

More widely, clearly no solid cold spell any time soon, but I wouldn’t be at all surprised that with the “smoothed out” westnorthwest synoptics that we’re seeing a lot of across the models for the first half February, but with cold uppers never too far away, that in reality, there could well be a few other shortwave half-chances that only firm up in the 2-5 day period and give us the chance of an occasional covering. 

I’ll concede to accusations of rabidly optimistic straw-clutching, guilty as charged 

However:

- These “local” events are always much more likely to crop up in the second half of winter in any case, and a lot more likely than when we have a 1035mb high slapped over our heads for weeks on end. 

- With a consistent northwest synoptic bringing a maritime fetch from just south of Greenland and disturbances being regularly delivered in cold air to the west of Iceland from a lively PV, along with the maintenance of the trough into Eastern Europe, there’ll be reasonable scope for small lows to develop to our northwest and track over us, pulling down colder upper air from the north as they do. 

- This is also supported by looking at the subdued jet stream. As long as our weather is not being governed by high pressure, I.e. jet too far to the north, or by a strong jet stream too near, there will always be scope for undulations in a weaker jet to develop these small features that tap into the colder air and move down over the UK and Ireland. 

- In between the extended periods of high pressure, it’s been that kind of year. 

 

[Gowon]

The ECM is more amplified to our NE at 168h.. 

[Battleground Snow]

7 minutes ago, D.V.R said:

The ECM is more amplified to our NE at 168h.. 

Yes it's moved a little bit back towards what it was showing a couple of days ago...

Need more heights in this circled area tho

[Allseasons-Si]

Interesting,...this should cheer a few on here ,....by day 9 on the ECM

a little feature running into cold air could give quite a dumping.

 

Edited January 26, 2022 by Allseasons-si
typo

[Don]

Different day, same old uninspiring charts!

[Tim Bland]

️

[Ali1977]

4 minutes ago, Allseasons-si said:

Interesting,...this should cheer a few on here ,....by day 9 on the ECM

a little feature running into cold air could give quite a dumping.

 

Indeed , and I have no doubt that it’ll be gone on the next run - but it’s nice to see some “ weather’ on the cards 

Edited January 26, 2022 by Ali1977

[Don]

1 minute ago, Tim Bland said:

️

Close but no cigar for my location!  Would be nice if it came off like that though.

[damianslaw]

36 minutes ago, Cambrian said:

With its timing during the night hours, the little low pressure for early next Monday (by then thank goodness we’ll be getting right to the end of this relentlessly savage January), is shown with a bit more clarity on the 12z GFS operational run. 

It drags down some quite cold uppers, coinciding with the precipitation, and though at the moment limiting snow to higher ground in the north, might well in the event do better than currently advertised, especially inland. Worth keeping an eye on perhaps. 

108h

 

114h

  
 

A sneaky little snow half-chance maybe, but needs must…

 

 

More widely, clearly no solid cold spell any time soon, but I wouldn’t be at all surprised that with the “smoothed out” westnorthwest synoptics that we’re seeing a lot of across the models for the first half February, but with cold uppers never too far away, that in reality, there could well be a few other shortwave half-chances that only firm up in the 2-5 day period and give us the chance of an occasional covering. 

I’ll concede to accusations of rabidly optimistic straw-clutching, guilty as charged 

However:

- These “local” events are always much more likely to crop up in the second half of winter in any case, and a lot more likely than when we have a 1035mb high slapped over our heads for weeks on end. 

- With a consistent northwest synoptic bringing a maritime fetch from just south of Greenland and disturbances being regularly delivered in cold air to the west of Iceland from a lively PV, along with the maintenance of the trough into Eastern Europe, there’ll be reasonable scope for small lows to develop to our northwest and track over us, pulling down colder upper air from the north as they do. 

- This is also supported by looking at the subdued jet stream. As long as our weather is not being governed by high pressure, I.e. jet too far to the north, or by a strong jet stream too near, there will always be scope for undulations in a weaker jet to develop these small features that tap into the colder air and move down over the UK and Ireland. 

- In between the extended periods of high pressure, it’s been that kind of year. 

 

Feb 99 springs to mind. Bursts of polar NW air at times. 

[blizzard81]

Lets hold off writing the obituaries for this winter - Very interesting that the ecm semi-reverts back to what it showed for a few runs up until yesterday's 12z backtrack. Lets see what the ensembles say. 

[damianslaw]

Interesting to see this runner feature for Sunday it seems to develop in the base of the trough and there are differences in its position. UKMO tracks it further south, ECM a bit further north and GFS further north still. Its looks a shallow low but with quite cold air wrapped within on its northern flank. It's something to watch at least after weeks of not much to look at. Its these type if features that can throw a wintry surprise. The follow up feature shown by ECM later next week shows a more southerly feature and hence wintry precipitation is enhanced. 

[Ali1977]

Well the ECM mean at day 9 does suggest PM air is possible, but whether that’s cold enough away from Northern U.K. high ground is another question. A good week for Scottish ski areas hopefully!! 

Edited January 26, 2022 by Ali1977

[Cleeve Hill]

ECM 
 

From 144 onwards, a much more seasonal look to things. A welcome change. 

[Lukesluckybunch]

oh somes it up again the ECM op was a cold outlier!

[BLAST FROM THE PAST]

Ok, we know I’ve called  for a stormy period from end of Jan and early Feb in Dec.  Interesting features turning up (even MetO are looking at a feature around 30th)

ECM t120

ECM t216

let’s look at these developments. The main deep troughs are still showing 500 mile too far east…but I think there’s movement still to be had on this.  Remember Storm Arwen.

 

GFS for 31st

 

UKMO T108

 

this has all ‘appeared’ very recently.  For me it’s heading right with time for intensifying.

BFTP

Edited January 26, 2022 by BLAST FROM THE PAST