Model output discussion - mid-winter

[Mucka]

5 minutes ago, Daniel* said:

? It’s a sizeable difference. 

For the type of weather a specific location on a tiny Island gets over a few hours it may seem that way but for a global model dealing with N hemisphere these are tiny changes in track - the track affects how the runner develops. You are talking less than 1% change at these scales.

[Ice Day]

GFS and UKMO at 144.  Both are looking cold with deepening cold to follow

GFS   UKMO 

[SLEETY]

6 minutes ago, Steve Murr said:

UKMO 144

cold all the way- into Northerlies by Friday !

Toppling soon after I think,cannot get a decent long lasting Northerly often 

[TSNWK]

5 minutes ago, Steve Murr said:

UKMO 144

cold all the way- into Northerlies by Friday !

Lovely chart! I’m I being too greedy by thinking that 960 low south west of Greenland is tilted ok and should pump up the very slight heights over greenie

[winterof79]

UKMO 144

A classic chart for a flabby low with streamers off the Irish sea

Edited January 13, 2018 by winterof79

[SMU]

4 minutes ago, Jonan92 said:

Big changes in UKMO, everything is moved to the east quite a lot

That’s because it’s 12 hours later

[Weather-history]

5 minutes ago, Mucka said:

GEM great with the runner low but awful in the Atlantic thereafter.

Let's hope it has the first part right and the second part wrong.

According to GEM just after the New Year, we would have an easterly spell by now

[Mucka]

8 minutes ago, Steve Murr said:

That’s because it’s 12 hours later

GFS certainly better though.

Edited January 13, 2018 by Mucka

[Day 10]

1 minute ago, Ice Day said:

GFS and UKMO at 144.  Both are looking cold with deepening cold to follow

GFS   UKMO 

Cheers for posting this chart comparison, always helps when out and about and only on phone. 

[karyo]

1 minute ago, TSNWK said:

Lovely chart! I’m I being too greedy by thinking that 960 low south west of Greenland is tilted ok and should pump up the very slight heights over greenie

It would have been better if the low southwest of Greenland was further west to allow a proper ridge to develop. This is touch and go.

[Jonan92]

Just now, Steve Murr said:

That’s because it’s 12 hours later

Not really, in 12hours you don't have this change

00z

12z (current run)

 

The change is better seen if we compare today's 120 with yersteday's 144

Yesterday

Today

[SMU]

1 minute ago, Jonan92 said:

Not really, in 12hours you don't have this change

00z

12z (current run)

 

The change is better seen if we compare today's 120 with yersteday's 144

Yesterday

Today

00z V 12z is pretty much no change-

Its 12 hours later which considering the fast pace of the jet gives plenty of time for everything to move East.

[SMU]

GFS our to 174 taking more energy south V 06z means it’s now edged closer to ECM perspective= colder for longer

[Weathizard]

Just now, Steve Murr said:

GFS our to 174 taking more energy south V 06z means it’s now edged closer to ECM perspective= colder for longer

The ridge still looks like it's going over though, unfortunately. Svalbard shortwave blocked progress of the other lobe of high pressure also

[Singularity]

 

Jet stream charts are useful when looking for disruption of a deep trough with a secondary low peeling away; we need the curve of the jet to the NNW or NW (in this case toward SW Greenland) to reach as far in that direction as possible, representing a ridge building in that direction. The trough then elongates NW-SE with the jet edging 'under itself' so to speak and then you're in theory on the road to a low breaking away and sliding SE, to the south of the ridge.

 

12 hours later and we can see how the 12z on the right has a better elongation of LP on a NW-SE alignment to the S of Iceland.

[Ice Day]

Out to 186 and it's still very cold.  From the middle of next week there's a corking 4-5 days of winter coming up with 'potential' for more to follow

[andymusic]

2 minutes ago, Ice Day said:

Out to 186 and it's still very cold.  From the middle of next week there's a corking 4-5 days of winter coming up with 'potential' for more to follow

doesn't really look like the next lows gonna get in intact either due to the cold freezing air already over us and lying snow helping it to keep it that way

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

I think this speaks for itself

[shaky]

3 minutes ago, RAIN RAIN RAIN said:

I think this speaks for itself

What the heck is that!!!!!

[bobbydog]

Just now, RAIN RAIN RAIN said:

I think this speaks for itself

yeah, in french...

[Mucka]

Cold col.

[snowice]

Just now, shaky said:

What the heck is that!!!!!

It's nick with his crayons

[Radiating Dendrite]

Parlez vous Francais?

[andymusic]

3 minutes ago, RAIN RAIN RAIN said:

I think this speaks for itself

very nice impressionist painting that - not sure what it's got to do with the models/weather though - explain please

[shaky]

18 minutes ago, Steve Murr said:

That’s because it’s 12 hours later

Steve have you seen latest arpege!!man it makes me laugh!!!its either gona pull òff one of the greatest upsets over the bigger models or have egg on its face!!takes the shortwave through NORTHERN SCOTLAND!!and then upstream its completely different to gfs ukmo as early as 114 hours!!??