Model output discussion - Closing in on Christmas

[NewEra21]

It's crazy we finally get a GH (or ridging at least) and everything falling into place, yet we barely scrape -4 to -5 uppers.

If all these great synoptics leave us with nothing, I just don't know anymore. We've got everything we crave and now no true cold air to pull in. 

You've got to laugh otherwise you'll cry

Edited December 20, 2020 by NewEra21

[bluearmy]

To those of you wonder where the cold air is on the dropping trough on gfs .......the origins of that system are currently developing off the carolinas. (Not cold). It will run up towards Greenland and then deepen as it encounters the colder uppers in the region. Thereafter, as it moves across Iceland, the v cold uppers from the north are dragged into its circulation as it deepens v quickly. Those cold uppers become mixed out because of the nature of the system. 
 

The main point here is that intense deepening systems headed se across the ocean are generally going to disappoint temp wise, especially at the beginning of a ‘cold spell’.

[SLEETY]

What are the Sea temperatures now compared to 50 years ago,its the obvious reason why the uppers aren't lower

[Skullzrulerz]

16 minutes ago, mountain shadow said:

Unbelievable isn't?

A proper Greenie High and still we can't get proper cold air in.

Maybe this is empirical evidence of global warming.

It's such a waste as these synoptics are rare! 

 

[Tim Bland]

 Beautiful....you can see how it can (and probably will) go wrong, but nice to dream that we end up in this position in jan with a SSW up our sleeve ... 

[TSNWK]

My thoughts on uppers are that if we can maintain the synoptic pattern the slightly colder uppers we crave might show up nearer the time.. I base this on what we seeing as ridge#1comes into the near range over Christmas Eve and day..

just putting it out there I guess

[bluearmy]

4 minutes ago, NewEra21 said:

It's crazy we finally get a GH (or ridging at least) and everything falling into place, yet we get barely scrape -4 to -5 uppers.

If all these great synoptics leave us with nothing, I just don't know anymore. We've got everything we crave and now no true cold air to pull in. 

You've got to laugh otherwise you'll cry

But that’s the point - it’s not a greeny high. It’s a transient greeny ridge. Thats v different as it doesn’t allow time for really cold uppers to advect sw. 

[Sweatyman]

So much doom n gloom on here this morning. Im not complaining at these charts! Sure it will be cold enough for some places to get Snow

[sheikhy]

Control going the same way!!!!upgrade on the mean at 156 hours as well!

Edited December 20, 2020 by sheikhy

[northwestsnow]

Certainly northern areas with decent altitude ,perhaps 250m at a guess, might see some snow after Christmas,if GFS is to be believed...

[bluearmy]

2 minutes ago, northwestsnow said:

Certainly northern areas with decent altitude ,perhaps 250m at a guess, might see some snow after Christmas,if GFS is to be believed...

Have you got a 48 m pole you can climb up NWS? 

[blizzard81]

5 minutes ago, Sweatyman said:

So much doom n gloom on here this morning. Im not complaining at these charts! Sure it will be cold enough for some places to get Snow

Too right. Coldies should be ecstatic with the current output considering the dross we have had to endure over the last few years. 

[bluearmy]

5 minutes ago, sheikhy said:

Control going the same way!!!!upgrade on the mean at 156 hours as well!

At day 7 the op and mean are extremely well matched .........that doesn’t always happen with gfs ! 

[Nick F]

Pity the EC and GFS want to drop the arctic high south into northern Russia in the medium range. This brings the risk of a piece of the trop vortex over Canada shifting east across Greenland to merge with the trop vortex heading SE to northern Europe between Christmas and NY, which cuts off cold air supply direct from the arctic and instead gives a less cold polar maritime air source from far NW Atlantic .

If WAA heights could build a block over Greenland area then this would lessen this risk.

Still much to be resolved past day 7 with where the trop vortex heading SE to Europe positions and what happens upstream over Atlantic and arctic around Greenland - so not worth micro analysing how cold the flow is and where snow is modelled at day 7-10 with each run.

 

[blizzard81]

Fantastic mean

[KyleHenry]

9 minutes ago, bluearmy said:

But that’s the point - it’s not a greeny high. It’s a transient greeny ridge. Thats v different as it doesn’t allow time for really cold uppers to advect sw. 

As you say there is no Greenland HP, the absolute destruction of the TPV is the only story in town. 

[northwestsnow]

3 minutes ago, bluearmy said:

Have you got a 48 m pole you can climb up NWS? 

Oldham very hilly mate, Frosty ground lives about 2 miles from my front door and he's around 300m ...half a mile up the road from him its around 340 m asl... 

I suspect that will be enough altitude if the precip is there ...

[Climate Man]

1 minute ago, blizzard81 said:

Too right. Coldies should be ecstatic with the current output considering the dross we have had to endure over the last few years. 

Indeed, moans about 850s but GFS showing perhaps 2 weeks of temps average to slightly below, can put up with that in mid winter.

[Tim Bland]

IF we get to this position we only need uppers a degree colder and we are in business.Hiw does the song go ..there no business like snow business

[northwestsnow]

4 minutes ago, blizzard81 said:

Too right. Coldies should be ecstatic with the current output considering the dross we have had to endure over the last few years. 

synoptically I absolutely agree.

Plus, a cold frosty Christmas eve is magical imo   

[TSNWK]

1 minute ago, blizzard81 said:

Fantastic mean

 

2 minutes ago, blizzard81 said:

Fantastic mean

Looks nice synoptic wise and we cannot have too many y complaints on that.. with what currently appears to be a GH ridge topple and repeat pattern. We are on ridge 3 forming around 300 and if I’m reading correctly ridge 4 is setting up west coast of USA.

for 850s the spaghetti plots are going to be Increasing helpful I think..

[feb1991blizzard]

This is going to be a proper Greenland high though, note the frigid air flooding SW towards us in a minute.

[blizzard81]

850 temp anomalies aren't too shabby imo. We should be really happy with this in late December  

[Shere Khan]

Back to seasonal weather from midweek onwards which will be welcomed by many over the Xmas period. Hoping for standard  cold snap in jan/feb. Looking at the remaining models for December, any decent cold spells can pretty much be ruled out now. 
Come on jan 1987 style Big freeze

[Battleground Snow]

For those worried about uppers at 180-240.. we have seen a drop of 2 degrees within 72 hours for Xmas eve.. not impossible for them to come down again at longer ranges, plus this is just one model op run. Let's wait to see what happens once we bring this into the 72-96 hour range with higher resolution short range models before we proclaim it will all be cold rain.