Model Output Discussion - Spring Has Sprung

[Lukesluckybunch]

Pert 22 would be the way forward!

[Mike Poole]

Very cold run, great alignment, from the GEM this morning, T180

GFS chalk to the GEM cheese!

Small margins earlier make a big difference to the UK blowing mild or cold.

[feb1991blizzard]

corker in-bound.

 

 

[Lukesluckybunch]

15 minutes ago, feb1991blizzard said:

corker in-bound.

 

Maybe feb..just don't want that shortwave near norway..phasing with the energy southwest of iceland..ended up bad,the Azores hp came and ruined things!..only mild here from day 8

Edited March 4 by Lukesluckybunch
Adding

[AO-]

Good Morning,

EC the complete opposite of yesterdays 12z. The operational is an outlier in the EPS. A cold couple of days possibly from next weekend onwards. Nice weather if you ask me. The bad thing is that nature is already ahead and "winter" would mean a destruction of everything just in bloom. 

[Lukesluckybunch]

Ecm a big mild outlier for london...good too see!

[TillyS]

There’s a big contrast between 0z GFS and 0z ECM on this morning’s outputs. At least, there is if you look at where I currently am in Norway. The GFS has the Scandi high as a pretty weak affair and dissipating quite quickly this week, which would be critical for me in the arctic circle. The ECM by contrast has the high holding on all week, especially up in the north.

GFS: weakening high:

ECM 1030mb big HP holding in the north:

 

If you’re interested in seeing some pretty snow pics taken on Saturday’s journey across the mountains, I’ve put them here:

 

[TillyS]

2 hours ago, feb1991blizzard said:

corker in-bound.

My concern with this is that there’s so little certainty surrounding it. Even the ECM is wobbly at the moment which is even more of a concern as it has been pretty unreliable these past couple of months. 

I do wish we would stop asserting claims on here which are based largely on speculation and hope. There’s nothing wrong with wishing: I love snow which is why I’ve come to Norway to find it, but we could all do without making claims that aren’t really based on reliable, consistent, model data inside credible timeframes. It just becomes a letdown.

This Scandinavian high is wobbly right now and you’d be unwise to bet against the GFS given its current form.

[RJBingham]

GFS, nothing cold or warm on offer.

ECM, not worth looking at after the 11th. 

[Summer8906]

Never mind the snow, I'm just looking for some hint of dry, or even average in the models.

Something like the GFS 00z will have devastating effects for much of the country in terms of excessive rainfall I suspect. It looks like March 2023 all over again. It needs to stop raining now; this is becoming a really serious situation. Cold dry or mild dry, I don't care anymore...

This is turning into a historically unprecedented spell of prolonged wet weather, more than 8 months already and counting. We desperately need a dry late spring and summer.

Edited March 4 by Summer8906

[RJBingham]

The 14th looks toasty 

[emmett garland]

 Summer8906 It is a very grim forecast if it verifies..Dublin had 45mm on rain on Friday  .Nearly all our months worth.. GFS is showing a constant Atlantic drivel..

[Met4Cast]

 RJBingham

Yup.

I've struggled to see the enthusiasm for anything properly cold to be honest, besides some deterministic runs/outlier ENS members modelling has been pretty consistent with predicting temperatures remaining around average for the foreseeable with very little sign/support of anything significantly colder. 

Later in the month will likely see some renewed high latitude blocking as the MJO cycles into more favourable phases in the context of rising AAM but by and large, it's game over for cold chasers. 

[danm]

 Met4Cast agree. Spring can deliver cold weather, but usually fleetingly. With every passing day and week, what would have delivered synoptically and from a depth of cold perspective in Winter, will not deliver at this time of year if it is entrenched cold and snow that sticks around for more than an afternoon that you are looking for. You need something exceptional to appear for that, such as a 2013 or 2018 set up. 

Edited March 4 by danm

[Rain All Night]

12 hours ago, Rain All Night said:

12z deterministic runs, out to Sun 10th (day 7)

We see significant divergence after day 5 this afternoon. Not sure what on earth's going on with that ICON run!

Only UKMO is showing the absolute nightmare washout scenario for next weekend, so that's something, though it doesn't look like the south coast will be able to escape some rain in any scenario.

12z ensemble means, out to Mon 18th (day 15)

The ECM and GEM means are now suggesting that the low actually will go under - but also that the Atlantic will still come back into the picture a few days later regardless.

The GEFS again prefers to bring the Atlantic back more quickly and with less equivocation.

Bonus

Meanwhile, far above, it's looking increasingly plausible that the stratospheric polar vortex may not be returning before the autumn. But what, if anything, will that mean for us?

0z deterministic runs, out to Mon 11th (day 7)

It looks likely that the low will fumble its limbo act and spray us with rain as it makes its way under next weekend.

0z ensemble means, out to Tue 19th (day 15)

The noble ECM is putting up more of a fight against the Atlantic than the other two models from 11th March onwards. The GEFS is, again, pretty depressing to see.

Edited March 4 by Rain All Night

[Sherry]

Gfs ensembles are just keeping everything average through to mid march and beyond! No sign of anything cold! I really think it’s time to give up the cold chart chasing now, all your chasing is fantasy the sun is gaining strength and we will need something significant and there is no sign of that 

[Crackerjack]

 danm agree but here in lowland southern UK the 2” snow we had Saturday is still on the ground in patches through the woods day 3 and yesterday was +9c so that makes me happy I don’t need 2ft drifts to enjoy actually seeing snow. With careful holiday planning this past winter in Scotland too this is day 17 of being in snow in some form or another

im hoping the GEM earlier (unlikely) is on to something just to end the chase for snow this winter and not the rather rain fest charts from the GFS. We will see. 

[Rain All Night]

Just for fun now that we have two full-length 6z runs to compare, and I know which one I'd take...

[Lukesluckybunch]

What a mess this 12z run is from the gfs..not looking good at all..

[Lukesluckybunch]

Ukmo144 ..I'm thinking the extended might be good!

Edited March 4 by Lukesluckybunch
Adding

[Kirkcaldy Weather]

On 21/02/2024 at 20:17, Kirkcaldy Weather said:

During week 1 of March with further influence from phase 7 of the MJO this could see further connections between the Canadian Maritimes Blocking and the Block to our East Northeast with potential this evolves into a Greenland High a la 

 

On 27/02/2024 at 21:05, Kirkcaldy Weather said:

As a high which is currently building further to our East begins to strengthen once the retrograding begins this will move westward to sit to our East also during this our cut off low also retrogrades westward into the Atlantic, this combination suggests a plume setup during week 1 of March is a real possibility.

Starting at this point looking into the dynamics at play, as the Atlantic High moves eastward into Spain this will connect to the high developments to our East - Northeast from the south Southwest which does give a plume style pattern though brief. 

For the 2nd part of dynamics leading to the strengthening Blocking this comes thanks to the recent impressive strongly -PNA which was the strongest negative phase we've had all winter.

As the -PNA high energy moves into the block to our Northeast there are indicators this may become at / record intensity of hpa for this timeframe with blacks and purples which are particularly useful spotting these.

Leading on from my post here 

 

"Following on from this I'm seeing a trend for a possible transition into yet another of the precursor setups for further stratospheric warming.

Current timing looks to be the very last days of February into March week 1.''

Very happy with those estimates

This gives a boost to the stratospheric warming which is ongoing with feedback of this setup into a strong warming event during March week 2.

So looking in some detail at some of the evolutions from now through the first half of March.

We've got some wave break action which causes an upper level cold pool to move roughly northwestward from Europe to the North Sea 

As the High begins to retrograde this sends its accompanying wave break low / upper level cold pool northwestward whilst our cut off UK - Ireland trough also creates further cut off low developments into Italy.

As I've been covering in my recent posts my main interest with regard to opportunities of below average conditions from the Northeast and East has remained focused from week 2 of March.

With the Scandinavian Block continuing its retrograding movement west northwestward to Greenland blocking this will open the door to exactly the above.

With a deep Atlantic trough and a Southerly tracking Jet Streak this will see plenty of colder than average temperatures at surface and upper levels (some significant) tracking across Southern Europe and parts of Northern Africa, those who follow my posts may remember various times during winter which produced flash flood risks across Portugal, Spain and progression further east... this is another prime showcase.

Where the 500hpa setups will evolve to in a weeks time is perfect to where I'd expect to be given all teleconnective feedback which includes the prior stratospheric warming(s) feedback

Following onto my post above.

This is an impressive MJO cycle with a strengthening amplitude from the Indian Ocean which looks to maintain amplification as it crosses the Maritimes and heads into the Pacific. Having discussed upto phase 2 we are beginning to have feedback of phase 3 heading from March week 2 > 3 with the storm track in America gradually shifting northward and the trends into cut off blocking with troughs either side and possibly stormy conditions.

 

Absolutely gorgeous.

[Lukesluckybunch]

Ukmo 168

[baddie]

 Summer8906 Hoping for a May 2023-style miracle. I remember at one point early in the month, the models were predicting a rubbish second half with the North much drier and sunnier, and look how that turned out. Northern areas were still dry anyways though

[Mike Poole]

Quite a difference as far as the UK is concerned by T168:

The first low goes under according to GEM and UKMO, the next low, UKMO it’s a case of ‘to be decided’, the GEM starts to inflate it, the GFS is well on the way to a wet and mild thereafter.  So UKMO this afternoon with the better block and cold option, with chance to add.  

[Cheshire Freeze]

GFS 12z- the wet continues