Model Output Discussion - heading into April

[Mike Poole]

ECM T144:

Worth keeping an eye on those T850's...

[Mike Poole]

ECM T168:

Is there enough forcing to push that high out west, over UK, on this run I'm not sure...

Where is everyone, seems like I'm having a conversation with myself, nothing new there in last 2 months I suppose!

Edited May 25, 2020 by Mike Poole

[Mike Poole]

And the answer is no, at T192:

[Djdazzle]

144 seems to be the key frame there. Could easily have gone the other way.

[Guest]

Ugh, ugly ECM output this evening. The U.K. finally gets dropped under a trough and wouldn’t lead to a thundery breakdown, just a gradual decline in conditions. There still seems to be a lot of uncertainty post D-6 currently, the ECM output is also backed up by a few of the GFS ensembles. 

[Faronstream]

Looks extremly cold from beginning of june for both GFS&ECMWF and forward, no change from this also cold may and wet conditions continuing 

[Djdazzle]

Truly dreadful ECM after 192. Hopefully an outlier.

[Mike Poole]

12 minutes ago, Djdazzle said:

144 seems to be the key frame there. Could easily have gone the other way.

I wish it had!  T240 is a horror show!

Highlights the uncertainty I suppose, but let's stay focused, in these times with no aircraft data, the op models can hardly be believed beyond T120...

Edited May 25, 2020 by Mike Poole

[Djdazzle]

2 minutes ago, Mike Poole said:

I wish it had!  T240 is a horror show!

Highlights the uncertainty I suppose, but let's stay focused, in these time with no aircraft data, the op models can hardly be believed beyond T120...

Doesn’t appear to be an output supported by background signals. Far greater chance of a settled June. Hopefully!

With a tiny difference at 144, that run could have gone onto to showing a hot outcome. Very finely poised.

Edited May 25, 2020 by Djdazzle

[MikeC53]

Yes the Crewe fella will be lovng this run, hopefully an outlier and fine margins took it down this route from day 7.

[Guest]

Yep that ECM T240 chart is the thing nightmares. Very easy for that pattern to hang around for a week or longer. 
 

 

[Djdazzle]

Just now, MikeC53 said:

Yes the Crewe fella will be lovng this run, hopefully an outlier and fine margins took it down this route from day 7.

It’s far too extreme to be anything other than an outlier. 

[Mike Poole]

This is what should happen, JMA T192:

[Singularity]

 

Spotted something big this evening - the MJO's retaining more amplitude across the Pacific than was predicted (by all models, with GEFS having been closest).

When a full propagation across occurs with amplitude, this has a two-faced effect. Initially, it reduces the likelihood of us making it through the first week or so of June without any more unsettled weather:

We can only work with these composites very loosely given the variability that occurs on top of the MJO, but you get the idea - support for a northerly and then an unsettled spell with Atlantic lows tracking south of usual.

Later, though, if the amplitude is retained as is now being modelled, the influence turns on its head:

 

Increasingly strong support for settled UK weather, probably warm too given the initial focus of anomalously high pressure just south of the UK.

I could certainly live with that - a bit of useful rain for the gardens etc, then settling down again in time for the longest days of the year .

Just like in winter, we're depending on the MJO not losing amplitude before it makes a full crossing!

Worth noting, by the way, that this is not a move to La Nina type forcing on the pattern - far from it, as the MJO crossing the Pacific with amplitude is disruptive to the La Nina standing wave.

 

With all this in mind, the general direction of the GFS and ECM 12z runs looks much more plausible - details aside. I do think ECM gives that low moving toward us Mon-Tue too much eastward momentum and that a focus of LP south of the UK early-mid-week, causing some interference with the pattern shift for a time, is more probable. 

[MATTWOLVES 3]

5 minutes ago, Mike Poole said:

This is what should happen, JMA T192:

I dont think we can compare JMA as in the same league as ECM though Mike. It does seem a little extreme by day 9-10..ecm that is.. But it's not out of the question, as Exeter do mention possibly a more unsettled spell next week, the thought being though that it will be relatively brief.. I'm not sure how this op will fit within the pack.. I'm expecting a halfway house tbh... But we will soon find out. 

[Man With Beard]

ECM seems to have given up on the really hot temperatures this weekend - raw temps between now and next Tuesday providing maximums for England/Wales of 22-25C (similar maximums for Scotland from Friday) - if the usual downplaying of temps is happening, we'll probably see 27C or maybe 28C at times, therefore. This looks similar to other charts, now. Just a tad lower on the east coast towards the end of the week. 

Pretty hot for late May, and looking like lasting throughout the reliable time frame. 

[damianslaw]

Reliable timeframe, up to 144 hrs, high pressure ruling the roost, although a cold front will bring some cloud and patchy rain to northern parts overnight, and a cloudy day for central parts tomorrow. In the main its a dry and warm outlook, perhaps not quite as warm as was looking, with winds backing into the east, rather than south east, less of a southerly draw, thanks to the orientation of heights being more W-E or even slightly SW-NE aligned - air source Germany and Netherlands and all points NE rather than France and central europe.

Beyond 144 hr timeframe, an air of uncertainty, ECM and GFS both develop a disturbance in the mid atlantic thanks to lowering pressure, this then develops into a cut off low feature to our SW in the case of GFS, with a possible thundery spell, followed by a cool northerly flow as heights build out to our west, ECM shows less of the cut off low development but also shows heights developing to our west and it to pulls in a northerly feed with heights dropping over the UK, resulting in cool unsettled conditions.

 

[Mike Poole]

Nothing in the ECM 12z mean at T240 to give anyone nightmares that might have been triggered by the op run:

There's some fine margins to get to that though I think, again we wait and will see,,,,

[Allseasons-Si]

The ECM mean from 144,not that bad really with height's linking from Azures to Scandi,the op looks like an outlier to me.

cracking mean

[MATTWOLVES 3]

The mean is certainly less severe than the operational was. So I think for now we can relax a little and perhaps have a cold one... Cheers.. 

Edit... What is it with operationals these days... Far to progressive and harsh.. 

Edited May 25, 2020 by MATT☀️

[Allseasons-Si]

And as expected,the ECM op is doing a GFS

Edited May 25, 2020 by Allseasons-si

[shaky]

2 minutes ago, Allseasons-si said:

And as expected,the ECM op is doing a GFS

What bout in terms of pressure!!!!i knew it was gona be an outlier anyway!!so amazing output tonight if heat and sun is what your after barr the last couple of dodgy frames from ecm op!!

[Allseasons-Si]

And there is no gremlins lurking in the woodshed from the cpc 500mb outlook anomaly's

it's looking fine and settled to me but i wouldn't mind a few thunderstorms chucked in too

[Allseasons-Si]

6 minutes ago, shaky said:

What bout in terms of pressure!!!!i knew it was gona be an outlier anyway!!so amazing output tonight if heat and sun is what your after barr the last couple of dodgy frames from ecm op!!

You really want to know...

i do hope that's not right come day ten,even the mean and ens drop the pressure.

 

 

Edited May 25, 2020 by Allseasons-si

[Leo97t]

I do think a fairly prolonged north westerly unsettled incursion will occur around 2-10th June. This set ups get stuck over with high pressure costing the low on all sides. There is fairly good agreement for this across the models with the Gfs op being very very persistent for a while now. Beyond that I see I a return to a UK high based pattern until at least the end of July as sst should promote a Atlantic low still