Model Output Discussion - heading into April

[Man With Beard]

ECM clusters this morning, really high confidence in the warm and settled set-up in the D6-D10 period. Strong reds just to the north/east, along with average or below average heights to the SW, means a stable draw from the south and east. 

  

Pretty much a bullseye for getting heat to the UK at this time of the year.

Still looks locked-in by D11

Some suggestions that heights will slip north / west as we head towards the end of the month, but not at all certain this will lead to a breakdown, the cluster 1 type often shifts further east as we get closer to the reliable:

[Frosty.]

Looking at the GEFS 6z mean most of the outlook is settled under high pressure (s), there’s a brief much cooler blip following the current very warm spell but by next midweek it’s warming up again and further ahead indicates plenty more warmth to enjoy until deep FI range...stay safe and enjoy this predominantly lovely spring weather.

Edited April 11, 2020 by JON SNOW

[Methuselah]

T+144, on the GFS 12Z, and things are going spiffingly!

    

[mb018538]

GFS has been abysmal recently. UKMO and ECM have been so consistent re next weekend I’d be amazed if they are far wrong. UKMO looks very warm again by the end of the week, this pattern in rinse and repeating a lot.

[Scorcher]

5 minutes ago, mb018538 said:

GFS has been abysmal recently. UKMO and ECM have been so consistent re next weekend I’d be amazed if they are far wrong. UKMO looks very warm again by the end of the week, this pattern in rinse and repeating a lot.

I hope it is just a case of GFS not performing- it's been so stubborn about later next week for so long now I'm starting to worry it could be onto something- looks unlikely though.

UKMO looks miles better and I'm expecting yo see something similar from the ECM.

[Methuselah]

GFS 12Z seems okayish until Day 10, when it seems to have trouble with that potentially annoying blob of cold air, still floating about over Europe:

    

But, as we are talking of Day 10 and beyond, I doubt that particular blob will be of much import, anyway...Though I could of course be very wrong. Only time will tell!

[Geordiesnow]

Don't think the GFS is that far off really, it's just forecasting troughing to be further northwards and eastwards so it means higher chance of rainfall for the UK. 

The hints from other models are mostly that a high pressure cell with increased thicknesses could come into play. An high with higher thicknesses means two things... Higher upper air temperatures and a stronger block. We shall see how things develop but I would not rule out troughing being closer to the UK just yet.

On a side note, already seeing some forecasters hinting we may need rainfall for the gardens.. Not being funny but the grass is still growing here in our garden, there is cracked soil but I bet the soil lower down is still wet enough hence nothing turning yellow and the continued grass growth. 

[mb018538]

7 minutes ago, Geordiesnow said:

Don't think the GFS is that far off really, it's just forecasting troughing to be further northwards and eastwards so it means higher chance of rainfall for the UK. 

The hints from other models are mostly that a high pressure cell with increased thicknesses could come into play. An high with higher thicknesses means two things... Higher upper air temperatures and a stronger block. We shall see how things develop but I would not rule out troughing being closer to the UK just yet.

On a side note, already seeing some forecasters hinting we may need rainfall for the gardens.. Not being funny but the grass is still growing here in our garden, there is cracked soil but I bet the soil lower down is still wet enough hence nothing turning yellow and the continued grass growth. 

It’s the op runs that have been shocking - loads in a row now, including the 12z which are miles cooler/unsettled than the mean...which looks great. Nearly up to 10c 850s again, almost 10c above average. You have to remind yourself it’s April and we should be in the low teens, not 20-25c repeatedly.

[Dominic Carey]

16 minutes ago, General Cluster said:

GFS 12Z seems okayish until Day 10, when it seems to have trouble with that potentially annoying blob of cold air, still floating about over Europe:

    

But, as we are talking of Day 10 and beyond, I doubt that particular blob will be of much import, anyway...Though I could of course be very wrong. Only time will tell!

What temperatures are likely with this pattern?

[stodge]

Evening all

The possibility of northern blocking later in the month remains very much on the table after some of the 12Z output.

There are two scenarios I would argue - the first is we keep heights close to the British Isles, perhaps more over Scandinavia, and that draws up a warm ESE or SE flow. Dry for most, dull and misty along eastern coasts and the threat of some more unsettled conditions to the SW depending on how organised the trough becomes.

The second scenario is the heights are too far north and the trough fills the gap - this is again not unusual for an early summer option. The trough sets up either over or close to the British isles but with little in the way of a jet the pattern stagnates - that either means rain or showers (or both) depending on how the trough is organised.

ECM remains less than convinced for now and that's worth noting but I'll be interested to see if we start seeing some hints of an E'ly evolution in the modelling before long.

[LRD]

6 minutes ago, stodge said:

Evening all

The possibility of northern blocking later in the month remains very much on the table after some of the 12Z output.

There are two scenarios I would argue - the first is we keep heights close to the British Isles, perhaps more over Scandinavia, and that draws up a warm ESE or SE flow. Dry for most, dull and misty along eastern coasts and the threat of some more unsettled conditions to the SW depending on how organised the trough becomes.

The second scenario is the heights are too far north and the trough fills the gap - this is again not unusual for an early summer option. The trough sets up either over or close to the British isles but with little in the way of a jet the pattern stagnates - that either means rain or showers (or both) depending on how the trough is organised.

ECM remains less than convinced for now and that's worth noting but I'll be interested to see if we start seeing some hints of an E'ly evolution in the modelling before long.

It might happen. It might not. However, from what I've observed recently, every time there has been a hint of northern blocking (not that there were many hints during the winter but there have been during the spring) it has failed. I recall the N'ly air stream that looked nailed for last weekend and we ended up with unusual warmth. And with the ECM not really buying into it at this stage, I remain sceptical.

Some might point to the one-day wonder NE'ly we're getting on Monday, I guess

Mid-latitude high is promoted here

[LRD]

10 minutes ago, LRD said:

It might happen. It might not. However, from what I've observed recently, every time there has been a hint of northern blocking (not that there were many hints during the winter but there have been during the spring) it has failed. I recall the N'ly air stream that looked nailed for last weekend and we ended up with unusual warmth. And with the ECM not really buying into it at this stage, I remain sceptical.

Some might point to the one-day wonder NE'ly we're getting on Monday, I guess

Mid-latitude high is promoted here

Ha ha ha! And then the ECM shows an E'ly in FI

No good to anybody at this time of year of course

[mb018538]

2 minutes ago, LRD said:

Ha ha ha! And then the ECM shows an E'ly in FI

No good to anybody at this time of year of course

ECM 12z has high pressure in the same place it had low pressure on the 00z. Probably a bit on the progressive side, but it’ll take a day or two to settle down. I expect to see it nearer the bottom end of the ensembles.

[Frosty.]

Looking at the GEFS 12z mean I think it’s clearly showing a blocked pattern for the foreseeable future with plenty of high pressure in the vicinity of the u k and following a very brief but sharp cool down from the north during the next few days, it soon starts to warm up again from around next midweek, especially across southern Britain with temperatures climbing into the 20’s celsius, at least for a time so I think the majority on here would be happy if something similar to this verifies, not guaranteeing a completely settled outlook, there could be a few heavy thundery showers around at times further south and there’s signs of heights draining away towards the end but for the time of year it looks predominantly very decent  

 

Edited April 11, 2020 by JON SNOW

[MATTWOLVES 3]

Some signs of Northern Heights later on with the ECM... this pattern can be very productive into May and beyond, not so much for coastal areas, but definitely inland spots.. I think I would rather see heights towards scandy than over Greenland at this stage... Still alot to be resolved though... And tbh i still think a good deal of settled conditions in the offing. 

Very nearly summer and hopefully a big reduction in covid cases... Still plenty of time to get that beach body folks.... Go on..... Show em who's boss. 

Edited April 11, 2020 by Mattwolves

[Djdazzle]

Not trusting anything beyond T120! After Monday things look like warming up again, and still a good chance it could develop into another good very warm spell. 

[Geordiesnow]

2 minutes ago, Djdazzle said:

Not trusting anything beyond T120! After Monday things look like warming up again, and still a good chance it could develop into another good very warm spell. 

Although the ECM is a cooler run and the risk of the trough bringing more cloud and perhaps some rainfall in the southwest is there on this run. In general though, it does look dry and settled. 

[Methuselah]

1 hour ago, Dominic Carey said:

What temperatures are likely with this pattern?

Nothing very exciting (low teens?) is probably the best description I can come up with, Dominic...That said, the Op and Control are on their own, once we reach Day 16:

    

[MATTWOLVES 3]

If High pressure is your thing, look know further than the ECM mean, and just to add the op was somewhat of a cold outlier regarding 850s....the mean a good 5c higher towards the end of the run... Pretty good all in all folks... Tek care. 

[stodge]

Looking at the main 12Z OP runs at T+240:

GFS:

GEM:

ECM:

[shaky]

Fantastic 18z gfs!!more in line with ecm mean and stronger high over us!!

[Frosty.]

If this was winter, the longer term GEFS 0z mean would have coldies licking their lips!..looking through the perturbations there is wintry potential for late April but also a few warmer members to show the duality of spring.

[Allseasons-Si]

Well i hope the 06z gfs doesn't verify as it is disgusting with a cold NE flow prob bringing wintry showers with possible snow over high ground in the north

a stunning chart for winter but you are 3/4 months too late,move on

[Methuselah]

Tuesday looks better:     

Friday's okay:                 

But, after that, it's best head for the Greenland Riviera! Phew! It's only the GFS 06Z!

                                       

 

Edited April 12, 2020 by General Cluster

[mb018538]

 

Oh look - another gfs op run that’s a massive cold outlier.

GFS and ECM both show high pressure moving to the north towards the last 7-10 days of the month, so perhaps make the most of any warmth that comes next weeks, as it could turn a fair bit cooler after. Not a great deal of rain about either, barring a few lighter spells.