Model output discussion - Into 2021

[Lukesluckybunch]

1 minute ago, Lukesluckybunch said:

People always mention about the lack of PV this winter and how that is constantly a good thing,yes it should help in terms of cold but with out that there is no real driver to our weather,what I'm saying is we may well need something to shake the whole pattern up a little bit.at the moment the weather just seems rather dull and boring quite stagnant,all the weather seems to be the other side of the hemisphere.I don't personally see anything very cold in the next couple of weeks we need troughing into northern and eastern Europe otherwise there is very little cold we can tap into,yes we can create our own cold pools but that's not anything severe.people keep mentioning about the ssw effects but even that doesn't guarantee cold it all depends where the split vortex lobes end up.having said all that I am no expert honestly and it could indeed turn for the better again,but as others have said this morning with the ECM and UKMO singing from the same sheet it does seem highly unlikely now.please if someone could tell me I am making sense here?

 

[Harsh Climate]

I think this preciptation chart shows well the 3 main areas at risk of snow tuesday

Area 1 - the south east corner, looks like a large streamer will set up shop. If uppers are cold enough could see some good totals down there but may be a bit marginal away from high ground.

Area 2 - Northumberland into south east corner of scotland. Another large feed of showers/streamer setting up. As usual Edinburgh will get hammered with a stream of showers but like in the south east will it be cold enough?

Area 3 - North east england Yorkshire. Slightly colder uppers here of -7 / -8 with occasional -9. Lots of showers piling in, would expect a good covering in many places, obviously high ground and away from the coast faring best. 

I think the potential for biggest dumping of snow is in kent/south east of london but that is far from cut and dry!

Edited January 3, 2021 by Harsh Climate

[Anthony Burden]

ECM going for a slipping high pressure to our west along with an uptick in temperatures,

also bringing back the normal states quo of Atlantic run low pressure.

GFS totally different going with the Icelandic  low pressure dropping down from the

northwest over the U.K. before drifting to the east,short uptick of temperatures 

before turning cold again very unsettled.Summing up very uncertain after 144 hrs / 168 hrs.

[Harsh Climate]

1 hour ago, weathercold said:

What a stunning u-turn from UKMO and ECM! The ECM essembles had been pointing at a warm up for a few days now but that is some flip.

Long way back to cold it seems now, the weather always seems to make fools of us.

 

I checked the gfs first this morning and was delighted that it hadn't reverted back to yesterday's 12z, expecting the UKMO and ECM to be buisiness as usual (from last few days) but nearly spat my coffee out in disgust at the treachery the two have just pulled on us all! 

[tinybill]

dont  know what the  gfs  had  over  night  but   the weather  looking very  wintry to say the least

[bluearmy]

06z icon jumps to Ukmo/ec at day 5

[northwestsnow]

5 minutes ago, bluearmy said:

06z icon jumps to Ukmo/ec at day 5

Is that even a suprise ?

Let's enjoy the next 4 or 5 days of wintry weather...

Without being dramatic though its not a good morning NWP wise..

[Catacol]

Morning all - hehe: we best hope that @Scott Ingham's belief that GFS models Greenland heights better than all other models is true.

Very volatile situation at the moment - as the SSW kicks off tomorrow the upper vortex is shredded according to GFS at 72h

Interesting watching to come....

Edited January 3, 2021 by Catacol

[Man With Beard]

ECM individual ensembles continue to trend milder in the mid range, with 29 out of 51 members now broadly westerly by D10 (up from 22 last night). Not passed the point of no return but the direction is clear.

Had a look at 500mb heights over the North Pole for D15 - nothing jumped out at me as particularly unusual in terms of blocking / reversals. We await signs of the SSW response at lower levels!

[northwestsnow]

1 minute ago, Catacol said:

Morning all - hehe: we best hope that @Scott Ingham's belief that GFS models Greenland heights better than all other models is true......

GFS is wrong at day 5...

I'd wager my house on it.

 

[Ali1977]

1 minute ago, northwestsnow said:

Is that even a suprise ?

Let's enjoy the next 4 or 5 days of wintry weather...

Without being dramatic though its not a good morning NWP wise..

The 06z will come to the rescue, we don’t want it undoing the current cold spell any earlier that’s for sure.

Looking at FI for SSW fallout is also in time range now so even if the cold does ease we have more in the back burner - hopefully!!

[Scott Ingham]

10 minutes ago, Catacol said:

Morning all - hehe: we best hope that @Scott Ingham's belief that GFS models Greenland heights better than all other models is true......

Yeah! 

Its on its own for sure this morning mate!

The 12z are certainly approaching that crossroad period to determine that!

What GFS normally does a bit better is model short waves in America and Greenland better.

We can see the GFS kicks this southern Greenland short wave east whilst on the ECM it doesnt and stops the High pushing deeper into Greenland

Very small margins which make a huge amount of difference.

7/10 times gfs does model this area a little better than the Euros and it shows how small macroscale features in our part of the world can scupper cold.

Watch for this on the 06z

Edited January 3, 2021 by Scott Ingham

[sebastiaan1973]

6 minutes ago, Man With Beard said:

ECM individual ensembles continue to trend milder in the mid range, with 29 out of 51 members now broadly westerly by D10 (up from 22 last night). Not passed the point of no return but the direction is clear.

Had a look at 500mb heights over the North Pole for D15 - nothing jumped out at me as particularly unusual in terms of blocking / reversals. We await signs of the SSW response at lower levels!

Well we do a rise in pressure at the Northpole in general terms. The average for 240H is a weak westerly flow. Good in line with the stratospheric vortex displacement.

[Catacol]

Modelling of the N Pacific low is key. At 84 hours the 06z is already modelling it very differently than the 00z. It just might be that this record breaking feature throws a spanner in our works. That would be about right for UK winters!

Still a long way to go. Many a twist and turn to be had...

[Scott Ingham]

4 minutes ago, Catacol said:

Modelling of the N Pacific low is key. At 84 hours the 06z is already modelling it very differently than the 00z. It just might be that this record breaking feature throws a spanner in our works. That would be about right for UK winters!

Still a long way to go. Many a twist and turn to be had...

Yes we want it to push as south as possible into the States pushing up a small ridge ahead which in turn pushes that shortwave ive circled on my reply to you east away from Greenland.

Shows how tiny things can affect our island

If anything this should be a better run than the 0z

Have you seen it digging further South?

The GFS is better at modelling small scale lows in the US

So o dont think people should get too hung up yet

Edited January 3, 2021 by Scott Ingham

[Methuselah]

So, as anticipated, today's menu consists mostly of rain/sleety rain (at least just now)... But, come Tuesday, T850s do look much more conducive to snowfall:

    

Only time will tell; marginality can be a cruel mistress!

Edited January 3, 2021 by General Cluster

[Harsh Climate]

Stronger block in atlantic and towards greenland, think this will be a good run. GFS6Z  T87

Edited January 3, 2021 by Harsh Climate

[That ECM]

Sticking to its guns for me

[Scott Ingham]

1 minute ago, Harsh Climate said:

Stronger block in atlantic and towards greenland, think this will be a good run. GFS6Z  T87

See my posts to Catacol to explain why and what we need to look for

GFS is king in modelling these features so i still feel optimistic come the 12z

Edited January 3, 2021 by Scott Ingham

[Harsh Climate]

1 minute ago, Scott Ingham said:

See my posts to Catacol to explain why and what we need to look for

Yeah the modeling of that pacific low is key! Keeping my eye on it.

[Ali1977]

Similar looking GFS 06z (top) at T126, maybe even better with stronger heights clipping West Greeny 

[SMU]

Having watched the GFS / UKMO for about 20 years now its clear the amount of times GFS > UKMO / ECM is low.

> You know when its going to be wrong, when it throws out radical changes from run to run scattering lows everywhere.

> Equally the only time GFS wins is when theres been atlantic pressure & the model runs with metronomic consistency.

Looking at the ECM its been pretty rough lately, the modelling of the Easterly was fine UKMO was good. So its really a straight out battle.

After another consistent 06Z run which is infact a bit more amplified.

I make the GFS favourite. just about 60-70%.

S

 

[Scott Ingham]

Deeper North Pacific low and look at the difference

If your calling the cold spell over your braver than me when it all hinges on an American short wave!

Youd think as the aam rises from the monster eamt this low will be modelled further south

So give it till t-96 to call off chances

[Scott Ingham]

1 minute ago, Harsh Climate said:

Yeah the modeling of that pacific low is key! Keeping my eye on it.

The GFS trumped the ECM two weeks ago on a similar thing when i was banging the drum about it. So dont write off chances

[Scott Ingham]

1 minute ago, Steve Murr said:

Having watched the GFS / UKMO for about 20 years now its clear the amount of times GFS > UKMO / ECM is low.

> You know when its going to be wrong, when it throws out radical changes from run to run scattering lows everywhere.

> Equally the only time GFS wins is when theres been atlantic pressure & the model runs with metronomic consistency.

Looking at the ECM its been pretty rough lately, the modelling of the Easterly was fine UKMO was good. So its really a straight out battle.

After another consistent 06Z run which is infact a bit more amplified.

I make the GFS favourite. just about 60-70%.

S

 

Its king in america and it hinges on an american low pressure.

People have reacted to morning model runs again i believe