Model Output Discussion - heading into April

[Singularity]

With AAM looking to cycle around neutral, its likely that the Azores High will try to focus more west of the UK at times in June.

If that coincides with a spell of negative AO then something like the GFS 00z could happen - but the model tends to be way too enthusiastic with that in the 8–16 day range, so it’s persistent flag waving for such a thing doesn’t mean a lot to me. I consider it a 20% probability for 1st half June.

At the other end of the scale, lows by Iberia can allow high pressure to extend east relatively weakly while focused to our west. This can produce very warm but sometimes unstable weather. I’d give that about a 40% chance. Perhaps our best chance of appreciable rainfall!

The other 40% goes to high pressure close to the west with lows over Scandinavia southward. Cool or chilly nights, days cool in north but pleasantly warm in south. Scattered showers possible whenever cool air moves across aloft.

To be clear - that’s one part of the June story, during the low part of the AAM cycle. The high part brings other possibilities - highs through S UK / C Europe, that sort of thing. 

Edited May 25, 2020 by Singularity

[Methuselah]

Well, isn't the GFS 06Z's prediction for Friday a beaut!

    

Great for Cornwall too? Phew. What a scorcher!  

[MP-R]

Well there's a fairly consistent signal for air of northerly origin into June, but each set of runs delays the onset of the high moving westwards, and the northerly is becoming increasingly anticyclonic with time, with any unsettled weather being pushed back.

At one point, it was looking like a change on the 1st/2nd, now it might take until the second full week for an actual trough to affect the UK (that is of course if this northerly route comes to pass). Certainly no signs of Atlantic inroads. All in all, a beautiful week to come this week, but at least at the moment it looks like a continuation of largely dry conditions into June, if not as warm/sunny.

[shaky]

11 minutes ago, Singularity said:

With AAM looking to cycle around neutral, its likely that the Azores High will try to focus more west of the UK at times in June.

If that coincides with a spell of negative AO then something like the GFS 00z could happen - but the model tends to be way too enthusiastic with that in the 8–16 day range, so it’s persistent flag waving for such a thing doesn’t mean a lot to me. I consider it a 20% probability for 1st half June.

At the other end of the scale, lows by Iberia can allow high pressure to extend east relatively weakly while focused to our west. This can produce very warm but sometimes unstable weather. I’d give that about a 40% chance. Perhaps our best chance of appreciable rainfall!

The other 40% goes to high pressure close to the west with lows over Scandinavia southward. Cool or chilly nights, days cool in north but pleasantly warm in south. Scattered showers possible whenever cool air moves across aloft.

To be clear - that’s one part of the June story, during the low part of the AAM cycle. The high part brings other possibilities - highs through S UK / C Europe, that sort of thing. 

Another day another set of very food model runs!!!temps in the mid 20s and sunny all the way!!also that northerly keeps being pushed  back on the gfs each and every time!!whats with the gfs having this northerly fetish?ecm has hardly shown any northerly and so far is proving to be correct!

[Guest]

While gfs 06z keep pressure higher it’s really not a warm airmass by the weekend, western areas and northern Scotland potentially doing well, parts of the south east really could be chilly with a long fetch across the North Sea a stick in mid teens on the coast. 

[Methuselah]

I wouldn't necessarily call it 'chilly', myself...a couple of weeks' back, however, when the T850s were close to -6C, is what I'd call 'chilly'. And, even then, it was 11C at 2m!?

    

06Z looks like it might be a stonker...Maybe not?

[I remember Atlantic 252]

9 minutes ago, Alderc said:

While gfs 06z keep pressure higher it’s really not a warm airmass by the weekend, western areas and northern Scotland potentially doing well, parts of the south east really could be chilly with a long fetch across the North Sea a stick in mid teens on the coast. 

Aye and loads of north sea mist returning for most of Midlands

[Guest]

1 minute ago, General Cluster said:

I wouldn't necessarily call it 'chilly', myself...a couple of weeks' back, however, when the T850s were close to -6C, is what I'd call 'chilly'. And, even then, it was 11C at 2m!?

    

06Z looks like it might be a stonker...Maybe not?

Does really matter what the uppers are if the feed is across hundreds of miles of water at only 8-10c, it’ll be chilly in the east if the 06z came off.

[Methuselah]

2 minutes ago, Alderc said:

Does really matter what the uppers are if the feed is across hundreds of miles of water at only 8-10c, it’ll be chilly in the east if the 06z came off.

Of course it does, as do dps...And I can't see 'hundreds of miles of water' between SE England and Holland, anyway:

    

[mb018538]

D10 - split equally between these 3. Tough to call.

[Methuselah]

Cooler northerlies incoming...At Day 13! Just keep pushing it back GFS?

    

[Zak M]

If any of you here are needing rain, then this looks like a good chart for you

An approaching low to the south could bump into warmer air > thunderstorms with torrential downpours are possible if this comes off

[Methuselah]

And, wouldn't Day 16 be a fabulous end to a (too good to be true?) GFS 06Z!

     

Just as I doubt daily predictions of retrogression (about 365 times a year!) I have just as much difficulty in taking model-runs like this one very seriously...We can only hope, I guess!

 

Edited May 25, 2020 by General Cluster

[ChannelThunder]

37 minutes ago, Zak M said:

If any of you here are needing rain, then this looks like a good chart for you

An approaching low to the south could bump into warmer air > thunderstorms with torrential downpours are possible if this comes off

Pleeeease 

...it's guaranteed to be gone on the 12z 

[Methuselah]

Well, I must admit, I found this quite surprising: the 06Z is still on the cool side of the ensembles!

    

    

I'll leave to @JON SNOW to show us all the stonkers!

[mb018538]

 

This is interesting - around the 5th June there is a split of ensemble members going very warm/hot with a plume.....or the total opposite, much cooler. Take yer pick!

[Frosty.]

1 hour ago, General Cluster said:

I'll leave to @JON SNOW to show us all the stonkers!

Just for you Ed..actually there’s quite a few from the GEFS 6z but this is the hottest I think for the south!

Edited May 25, 2020 by JON SNOW

[MATTWOLVES 3]

I'm liking how the 6Z mean is ending deep in fi.. High pressure being set up for an Estly feed, pretty much like a 95 scenario.. And that airmass does become warmer with time.. Yes some coastal areas can be plagued by North Sea cloud at times, but it becomes a lovely picture a little further in land.. For me this is exactly the type of set up required if a long drawn out fine spell is your thing.. Quite a lot to like of how early Summer could be setting up. 

[Mike Poole]

Well the ICON 12z makes a complete meal of ridging over the top of the low that eventually becomes cut off, so some unsettled weather and thunderstorms in that period would be likely.  

[I remember Atlantic 252]

4 hours ago, Zak M said:

If any of you here are needing rain, then this looks like a good chart for you

An approaching low to the south could bump into warmer air > thunderstorms with torrential downpours are possible if this comes off

No thank you! but models are trending to something of a breakdown around then

[shaky]

28 minutes ago, Mike Poole said:

Well the ICON 12z makes a complete meal of ridging over the top of the low that eventually becomes cut off, so some unsettled weather and thunderstorms in that period would be likely.  

Pretty good run if you ask me!!winds coming in from warm continent and mainly dry?odd storm here and there!!

[Methuselah]

Things are still looking good, for Friday!

    

[Mike Poole]

UKMO following ICON as far as I can see, T144:

[Zak M]

12z UKMO is good at 96

[shaky]

12 minutes ago, Mike Poole said:

UKMO following ICON as far as I can see, T144:

Lovely little cut off low there to extend the warmth!!!lets hope that low in eastern europe does not end up westwards towards the uk!!