Model Output Discussion - cold spell to end Autumn

[Allseasons-Si]

4 minutes ago, Day 10 said:

Weather for the week ahead in left to right order

You forgot to add this

[damianslaw]

55 minutes ago, FiftyShadesofWine said:

Ext eps still more blocky than before, euro trough still there but note the increasing Russian high as we move into Xmas week...

 

Indeed it is all eyes to our NE over the next few days, the  main forcing may well be coming from that direction as we enter the middle of the month, and will put a brake on any atlantic encroachment - only one way frontal/trough shortwave features can head and that is SE on a southerly path. In my earlier post, I said we may see a shortlived atlantic attack after the weekend, bringing slightly milder air to southern/western parts, but not northern parts, but then an eventual undercutter scenario with heights to the NE nosing SW into N Scandi.

 

[Devonshire]

7 minutes ago, Mokidugway said:

And if not ....

Not to mention ...

[Methuselah]

Certainly a buzz around the place tonight...so let's hope the GFS Pub Run doesn't make beeline for the fruit stand!

[SMU]

39 minutes ago, Allseasons-si said:

I am liking the look of this

mslp 15d anomly,shows a big scuasian block developing.

Thats a nice anomaly chart- although thats a 4 wave pattern !

Also if you look close you see the slight weakness in the blocking over southern Greenland which allows the atlantic in now & again..

On a positive note the ECM 850 ensemble mean V op posted on the page below indicates that when the atlantic slider is looking like arriving the mean is about 2-3 degrees colder than the op !

eyes down for the 18z-

S

Edited December 3, 2017 by Steve Murr

[Pembroke Dangler]

2 minutes ago, Steve Murr said:

Thats a nice anomaly chart- although thats a 4 wave pattern !

Also if you look close yoi see the slight weakness in the blocking over southern Greenland which allows the atlantic in now & again..

On a positive note the ECM 850 ensemble mean V op posted on the page below indicates that when the atlantic slider is looking like arriving the mean is about 2-3 degrees colder than the op !

eyes down for the 18z-

S

I did feel that the ecm was overplaying the eastward progress of the low next Sunday on the operational run, and it seemed to lower the heights to the north to quickly. Just seemed wrong to me. Westward corrections me thinks. 

[feb1991blizzard]

3 minutes ago, Steve Murr said:

Thats a nice anomaly chart- although thats a 4 wave pattern !

Also if you look close yoi see the slight weakness in the blocking over southern Greenland which allows the atlantic in now & again..

On a positive note the ECM 850 ensemble mean V op posted on the page below indicates that when the atlantic slider is looking like arriving the mean is about 2-3 degrees colder than the op !

eyes down for the 18z-

S

Isn't the first chart a 5 wave pattern, although one of the waves is very weak, surely its 5 ridges with 5 troughs?

[Allseasons-Si]

6 minutes ago, Steve Murr said:

Thats a nice anomaly chart- although thats a 4 wave pattern !

Also if you look close you see the slight weakness in the blocking over southern Greenland which allows the atlantic in now & again..

On a positive note the ECM 850 ensemble mean V op posted on the page below indicates that when the atlantic slider is looking like arriving the mean is about 2-3 degrees colder than the op !

eyes down for the 18z-

S

Yes i see that but it's 15 days away,my thinking is that the trough sinking further into europe and the subsequent block building to our NE putting the brakes on fron the Atlantic,battleground scenario?

[snowice]

18z time I have a feeling of upgrades nearer the time, you don't get a raging northly lasting 72 hours often without pop up disturbance in the flow

[Methuselah]

Holding up nicely @T+0...

[SMU]

23 minutes ago, feb1991blizzard said:

Isn't the first chart a 5 wave pattern, although one of the waves is very weak, surely its 5 ridges with 5 troughs?

Dont normally count the polar one but hey ho !!

PS a cobra run in the ECM suite

Edited December 3, 2017 by Steve Murr

[Man With Beard]

@karlos1983 this one is for you  

On weather.us, next Sunday's ECM control run is also a massive M4 corridor event - TO THE SOUTH! 

All southern counties between Exeter and Kent receive 12 inches of snow. The North Downs tops out at 18!!!

(Though must say those weather.us snow charts do seem slightly creative with the evidence sometimes... )

[MattStoke]

18z on track out to 0z 

[SMU]

20 minutes ago, Allseasons-si said:

Yes i see that but it's 15 days away,my thinking is that the trough sinking further into europe and the subsequent block building to our NE putting the brakes on fron the Atlantic,battleground scenario?

Quite possibly

expecting to see some mad charts as we progress through December

A proper white xmas would be nice-

[Rocheydub]

4 minutes ago, Ed Stone said:

Holding up nicely @T+0...

 

2 minutes ago, MattStoke said:

18z on track out to 0z 

It was funny the first time!

[Allseasons-Si]

1 minute ago, Rocheydub said:

 

It was funny the first time!

And..........we need to get to t0

[karlos1983]

4 minutes ago, Man With Beard said:

@karlos1983 this one is for you  

On weather.us, next Sunday's ECM control run is also a massive M4 corridor event - TO THE SOUTH! 

All southern counties between Exeter and Kent receive 12 inches of snow. The North Downs tops out at 18!!!

(Though must say those weather.us snow charts do seem slightly creative with the evidence sometimes... )

Yes they generally overdo snow accumulations by around an inch I’ve found 

nice one MWB, I will run down the street naked if that happens, (after the watershed) 

[MattTarrant]

Just now, karlos1983 said:

Yes they generally overdo snow accumulations by around an inch I’ve found 

nice one MWB, I will run down the street naked if that happens, (after the watershed) 

It wasn't the control which showed this snow event. It was the 1st member. 

[karlos1983]

Just now, MattTarrant said:

It wasn't the control which showed this snow event. It was the 1st member. 

Ah yes , member #1 AKA the trend setter 

[MattStoke]

5 minutes ago, Rocheydub said:

 

It was funny the first time!

Didn't see the first comment, so shoot me! Meh 

[MattTarrant]

Just now, karlos1983 said:

Ah yes , member #1 AKA the trend setter 

Yeah absolutely 

[feb1991blizzard]

2 minutes ago, MattTarrant said:

It wasn't the control which showed this snow event. It was the 1st member. 

No, but the Control does show a hefty snow event as well though, just for the North, its like the reverse of number 1, all the areas that get pasted on the control are the ones that don't on 1.

[MattTarrant]

Just now, feb1991blizzard said:

No, but the Control does show a hefty snow event as well though, just for the North, its like the reverse of number 1, all the areas that get pasted on the control are the ones that don't on 1.

This is a question for anyone. The alteration of initial data, do the first perturbations have closer initial conditions than say number 20 to the raw operational data? Or does it work in different manner? 

[comet]

15 minutes ago, Allseasons-si said:

Yes i see that but it's 15 days away,my thinking is that the trough sinking further into europe and the subsequent block building to our NE putting the brakes on fron the Atlantic,battleground scenario?

Would not mind seeing the synoptics trending that way myself.

Hopefully we are in for a pub run special and not go down the euro route.

[snowking]

11 minutes ago, karlos1983 said:

Yes they generally overdo snow accumulations by around an inch I’ve found 

nice one MWB, I will run down the street naked if that happens, (after the watershed) 

Yep, it all comes down to the snow:rain equivalent ratio - it will be tuned for the US where the ratio usually sits around 10:1.

Across this side of the pond it's far more varied, but generally it's closer to 3 or 4:1

Of course, the other explanation is that everyone overstates things by about an inch anyway...

Edited December 3, 2017 by snowking