Model Output Discussion - May and Early Summer!

[StormChaseUK]

The 18z this evening could throw a surprise I think

[Mike Poole]

I've not posted much in the last few days because, in the timeframe I'm generally interested in - that beyond the reliable, where uncertainty is key, there really hasn't  been a clear signal to me, if you look at the op and ens models vs the seasonal models.  

I think that might change over the next day or two, ECM ensemble mean T240:

Suggests a ridge approaching, and the high lat blocking receding in strength, we will see but I think by 12z tomorrow we might be looking at a rather different outlook.

Edited May 17, 2019 by Mike Poole

[Frosty.]

Tonight's Ecm 12z ensemble mean suggests a pretty benign outlook with plenty of fine, warm and sunny weather but also showers breaking out, some heavy with thunder..in a nutshell some days will be less showery or may even be fine due to weak ridging and the rule of thumb is that the warmest conditions are further south with the north of the uk a bit cooler, especially later.

Edited May 17, 2019 by Frosty.

[knocker]

Outlook - the general theme of the evolution in the medium term appears to be the migration of the high pressure west and the troughs associated with the two vortex lobes to take closer order in the north west Atlantic and Europe with the Atlantic becoming a tad more fluid courtesy of interaction between the latter and the subtropical high.

In the meantime the UK remains under the umbrella of a slack area of low pressure with the detail a bit tricky to pin down.

The NH 500mb profile and the surface analysis for midnight.

Today will start cloudy in many areas but particularly northern Scotland where it is a very dank start to the day courtesy of the occlusion training back from southern Scandinavia. And the rain from this will hang around most of the day resulting in a very chilly day. Further south quite a few showers but with frequent sunny intervals. much warmer.

The showers will fizzle out overnight but patchy rain from the occlusion will still linger over NW Scotland and through the early hours stratus and mist may well ingress eastern areas.

A bit of a mixture for tomorrow. The patchy rain will still be effecting N. Ireland and western Scotland and Stratus and mist may well linger in eastern coastal regions but elsewhere it will be sunny and quite warm with showers developing, that could be quite heavy. The temps will reflect some of this

Over Sunday night and through Monday the country is still in the western flank of the trough so once any early morning mist has cleared another day of sunny intervals and showers beckons.

A similar scenario pertains over Tuesday and Weds with the UK in the western periphery of the low pressure so again sunny intervals and showers with perhaps some more persistent rain in the north on Wednesday as a warm front tracks south. Temps a smidgen above average on both days

 

 

Edited May 18, 2019 by knocker

[knocker]

Over the rest of next week we are getting into territory mentioned at the beginning of the post above with the high cell over Greenland (albeit still some ridging N. Scandinavia) and with further troughs moving east in the Atlantic and phasing with the subtropical high.

The upshot of all this is a surface low tracking north east Frid > Sun resulting in rain then showers with temps varying around average.

[Badgers01]

10 hours ago, StormChaseUK said:

The 18z this evening could throw a surprise I think

Out to day 7 remarkable consistency with high pressure to north and meandering filling low pressure over uk with winds often from north .... all a bit meh !

[knocker]

The ecm also has a trough tracking east at the end of next week

[Frosty.]

40 minutes ago, Badgers01 said:

. all a bit meh !

Disagree, the week ahead looks warm with sunshine and heavy showers / thunder..temps close to 20-21c on some days..not meh to me!!

[knocker]

Perhaps if people stopped using subjective terminology it would make nitpicking redundant

Edited May 18, 2019 by knocker

[knocker]

And the EPS mean anomaly is pretty much where came in earlier

[seabreeze86]

1 hour ago, Frosty. said:

Disagree, the week ahead looks warm with sunshine and heavy showers / thunder..temps close to 20-21c on some days..not meh to me!!

Depends were u are frosty it looks very cool along the east coast as it has been for some time now

Day 7 on ECM is abysmal 

[Frosty.]

1 minute ago, seabreeze86 said:

Depends were u are frosty it looks very cool along the east coast as it has been for some time now

Day 7 on ECM is abysmal 

True but there's plenty of warm weather inland for most of the week ahead with sunshine and showers, some heavy and thundery.. I have sympathy for you on the East coast although at least you probably have better views from your house than I do.

[Summer Sun]

Quite a bit of rain around over the next 10-days some of it could be torrential in Scotland with over 100mm over the higher ground

[Methuselah]

Could the build of pressure, over mainland Europe, be the time when the long- and short-range models come together?

 

Maybe, but even the FV3's north-south divide wouldn't be too bad. (crap model!)

GEFS ensembles:

Here's a chart from late May 1983. Awful, innit?

 

 

Edited May 18, 2019 by Ed Stone

[Frosty.]

Most of the Ecm 00z ensemble mean indicates warm and showery with sunny spells but later on the azores high / ridge is lurking with intent!!!

[I remember Atlantic 252]

1 hour ago, Summer Sun said:

Quite a bit of rain around over the next 10-days some of it could be torrential in Scotland with over 100mm over the higher ground

Yes but also warm sunny spells too, as Frosty points out, will feel decent out of any showers, thought I would mention

[MATTWOLVES 3]

I think the general situation is sunshine and showers, some parts getting frequent showers and others not many! And it will most definitely feel warm in sunny intervals. Things look a bit more unsettled come end of week with low pressure taking hold, so temps will be suppressed.... And there are some signs on the GFS 0z of a pressure rise towards the SW by next weekend which could herald a more settled and warmer spell going forward, especially in more southern parts! Alot to play for up until this point, and alot could change, so let's just see how it goes...

Edited May 18, 2019 by Mattwolves

[Fourty Point Three Degrees]

The GFS 00Z run & ensembles were poor, no warmth & very unsettled with diurnal showers right through into early June.

[MATTWOLVES 3]

3 minutes ago, 38.5*C said:

The GFS 00Z run & ensembles were poor, no warmth & very unsettled with diurnal showers right through into early June.

The 0z is clearly showing high pressure building from the SW, we must be viewing alternate model runs

[MATTWOLVES 3]

And again on the 6z signs of the Azores high nosing in to the SW! it makes no sense to state things are looking poor for 2 weeks at a time when there is so much model inconsistencies. 

And just to prove that point, the 6z is clearly moving in a different direction to the 0z,but apperantly the 0z and the 12z are the more significant runs, so perhaps I will hold fire til this evening! 

Edit.. I should have posted the 0z for comparison, but anyhow it was clearly different at similar time frames. 

Edited May 18, 2019 by Mattwolves

[Methuselah]

End of the 06Z is looking good. Yes sirree, Bob!

 

Hopefully, this is where the short-/long-term models, teleconnections and the ENSO long-wave pattern all come together?

And, now for the FV3?

Edited May 18, 2019 by Ed Stone

[Mike Poole]

I think we may just need to wait next week out.  As Karl noted above, the ECM mean has the Azores high waiting in the wings at T240:

Hint from the GFS 6z going the same way, same time:

And hints that we may finally be seeing that uptick in atmospheric angular momentum that might help reinforce a ridge from the Azores.  GWO (chart from 15 May) heading towards phase 5, a push towards 6 would be welcome, and probably the likely outcome:

 

Edited May 18, 2019 by Mike Poole

[MATTWOLVES 3]

Here is a look at the later runs of the 6z a day apart just to see if there are any consistencies. 

Edit... I finally got there, I posted the wrong  charts at least a dozen times then...

Edited May 18, 2019 by Mattwolves

[Mike Poole]

FV3 at T240 and T384 has the right idea for the start of meteorological summer!

Bank!

[Fourty Point Three Degrees]

31 minutes ago, Mattwolves said:

And again on the 6z signs of the Azores high nosing in to the SW! it makes no sense to state things are looking poor for 2 weeks at a time when there is so much model inconsistencies. 

The Gfs 06z is actually awful, especially bank holiday weekend as it always is by uk standard, cool and damp....but fingers crossed for a nice sign on the horizon showing the Azores ridging in from the SW by day 9 but doubt it will come off as with every other model run that does during summer months which only gets watered away or pushed back when it appears in the 8 to 10 day range. How many times we seen it happen in the past? My fingers now hurt as they were crossed for far too long during winter!

Edited May 18, 2019 by 38.5*C