Model Output Discussion - Spring Has Sprung

[nick sussex]

You’d hardly trust the UKMO at day 4 after its backtrack from the morning run.  

The GFS initially had the colder air further south but still ends up with the worst solution .  

[Lukesluckybunch]

Ukmo not great either..hoping for northeasterly at day 5

[frosty ground]

 swfc

yes because it has a much larger affect on the outcome than just transient snow.

indeed it might not even be transient if the GFS is wrong and could stick around for a while 

you could you know just stop moaning and ignore the discussion your not interested in? Just a thought? 

[MattStoke]

 Eskimo Snow much further south than its previous runs.

[Ice Day]

UKMO at 120 is rather different from the GFS

  

[nick sussex]

The UKMO completes a total capitulation at day 6 .

Scarcely believable that it could be so wrong at just T96 hrs .

[Mcconnor8]

Quite a contrast from UKMO at day 5 compared to the 0z run to say the least.

[Eagle Eye]

Let's talk SSW potential. 

What we don't want is the GFS 06Z to be repeated, it's an example of a wave becoming baratropic-ally stable before a wave-2 can occur and that leads to when the EHF disconnects (which is the switch from a baroclinic wave to a baratropic one) it's a wave-1 diffusion into the polar vortex. What that'll do is disconnect and stretch it but clearly Eurasia-ward. It's then both easier for the vortex to recover and become baratropic (vortex like) even when displaced right over Europe. Easily leading to a state where we're relying on a strong Greenland high surface response for any luck here as the SSW would be another negative for us and even that that's not looking good on the 06Z. This appears to be a trend with the GFS and has been the outcome of many recent SSW's over the last few years so I'm sort of inclined to believe it, the timeframe for a wave-2 being fairly short. It's another multiple rounds of wave-1 due to timing on the 06Z GFS, could well end up in a major SSW but later and still displaced based most likely. As once the EHF pushes polewards, it won't recover on the wave it just disconnected on. Timing as ever is important and it's currently an uphill struggle. Just a warning. Hopefully the 12Z is better. 

Away from the Strat, GLAAM on the rise soon/potentially now if it can maintain and w/the already +VE GLAAM and MJO 7-8 phase during a late Winter El Nino and enhanced Western Pacific-western Hemisphere (slightly) convective envelope then we have good support background signals wise. Greenland high easily supported at the moment later into February, how much that is helpful will depend on basing and actual strength of response. Good tropospheric signs but we're running out of time for them to produce. 

Edited February 5 by Eagle Eye

[Tim Bland]

 MattStoke would be short lived though. Perhaps snow to rain for midlands and by evening it’s only highest ground in north and Scotland ?

[frosty ground]

 nick sussex

like I’m looking at a different output.

low crosses the U.K. slightly different for the south

[Lukesluckybunch]

Where is all this northern blocking..that ec46 and various others are showing..gfs is really poor again!it's all hype I'm sure..you would have too say the gfs is correct here..it's been the same the past 3/4 runs..with the ukmo not being as good either..I'm fearing the worse from the ecm!

Edited February 5 by Lukesluckybunch
Adding

[Ice Day]

3 minutes ago, nick sussex said:

The UKMO completes a total capitulation at day 6

Does it?  That's not how I'm seeing it Nick.  GFS and UK at day 5 are significantly different, and I know which one I prefer

 

[sebastiaan1973]

How is it possible... 

[ANYWEATHER]

Looks like a rather miserable spell of weather coming up by the end of week/weekend.  Gfs sticking to its previous output. For snow lovers it's a kick in the teeth. Gfs performance has been leading the way for a good while now ,picking up trends, and other models playing catchup. 

[CoventryWeather]

Think there's one thing we can agree on, that models perhaps heading towards a middle solution. Somewhere like the NW Midlands and Yorkshire benefiting the most. But for now, until we get cross model agreement, we can't really pin down what is the right solution. 

[frosty ground]

 ANYWEATHER

can you show me another model that backs the GFS up? 

[IDO]

GEM stays closer to the GFS at D5-6:

 

[Dennis]

love it

[Lukesluckybunch]

1 minute ago, IDO said:

GEM stays closer to the GFS at D5-6:

Gem has potential at day 7..heights building further out west..away from the uk!

[snowspotter]

Hmmm I thought there was supposed to be a pattern change come mid February . This looks suspiciously like the same old mild sw airstream and high pressure over Spain and southern Europe that we’ve had now for about 3 weeks ! 

[frosty ground]

 IDO but the GEM get the low to cross the U.K. 

which leads to this

the constant comparisons to the GFS only viable if you do a full comparison 

[CoventryWeather]

Utterly a mess at the moment. 

FI about 48 hours. No consistency in model output. 

I'm going off for a bit. No point looking at individual runs. Let's see what the ensembles think and discuss from there.

[ICE COLD]

UKMO what have you done . It used to be the gold standard model up to day 5 . Big change from the 00z to the 12z at only day 4 . What a pile of poo . 
 

00z 

day 4 t108 

day 4 12z 

I give up with this winter . It just will not happen . Nothing goes are way. 

[IDO]

 Lukesluckybunch

True enough, but nothing like the EC, and that is what we wanted now that UKMO has also moved away from EC. Also, GEM is only scraps, nothing to be excited about, but as GFS is awful, I suppose it looks better than it is.

 frosty ground

I did say at D6, where the divergence with EC occurs. It has not followed the EC. And post D7 the GEM changes every run the last few days.

 eg, D9 GEM:

Edited February 5 by IDO

[northwestsnow]

GEM UKMO look very similar at 144

GEM is a decent run.