Model output discussion - first hot, thundery plume of the summer

[knocker]

As has previously been discussed the slow breakdown of the weekend ridge next week results in a more mobile Atlantic underneath positive anomalies in the Iceland/Greenland area, This is not necessarily as bad as it looks because within the general westerly upper flow the normal phasing of the Pm and Tm airmasses wil be accommodated and thus changeable weather of showers, perhaps some longer periods of rain but interspersed with plenty of sunny periods  The gfs take on this

[knocker]

A simple illustration of the regional importance of the precise orientation of the high cell

Moving on with the ecm take on the beginning of next week

[knocker]

And with reference to the earlier comment of the evolution via the gfs the ecm take on this

[SilverWolf]

1 hour ago, knocker said:

A simple illustration of the regional importance of the precise orientation of the high cell

Moving on with the ecm take on the beginning of next week

Hi Knocker, I’ve think I may have said this before in the regional thread. But I just want to say I really value your posts on here. I enjoy and am interested in a lot of the posts on here, right down to the extremities! But as a landscape gardener your posts are certainly the most useful to me personally. Thanks 

[Methuselah]

The GEFS 00Z ensembles are nae looking bad, today...though scatter still grows rapidly from the 21st:

  

  

The outlook could be much, much worse!

[danm]

All of the big 3 show it becoming a bit more unsettled midweek, especially the further N/NW you go. The S/SE looks less prone and could benefit from some ridges of higher pressure, but even here we’re likely to see some rain from Wednesday. 

Hints again that pressure could rebuild by next weekend on the GFS. The ECM wants to keep a shallow low over us next weekend, again mostly affecting northern areas, before pressure tries to build in by day 10. 

Anything beyond Wednesday next week is still some way off though and between now and then we have lots of dry, settled, warm, sunny weather to enjoy for the majority. 

Edited July 12, 2019 by danm

[Frosty.]

The Ecm 0z  ensemble mean seems to have improved again at day 10!

Edited July 12, 2019 by Jon Snow

[Singularity]

It's a bit of an odd situation next week; the jet stream is pretty weak, yet the models have it taking on a flat profile for at least a day or two. The result is 'slim' areas of low pressure with high pressure both to the north near or over Greenland and to the south across the Azores.

There's not a lot of cool air on tap, and not much strength of flow to drive it our way, so the overall temp mean may stay at or above average, though it won't feel that way as and when it rains during the day. It's hard to make any decisions on how the jet stream's most likely to be orientated during this time, as we have no robust tropical forcing on the pattern (the Nino standing wave is struggling & the MJO is weak). The outcome may depend on regional forcing such as N. Atlantic SST anomalies and Arctic sea ice patterns.
 

I'm keeping an eye out for signs of hot air building north through Europe next weekend onward, as we often see this happen following a period of weak zonal weather in the summer months, once the jet starts to meander about more. This being as the tropical maritime air, thrown eastward across Europe, tends to encourage a bit of ridge building there, which then circulates it back around to join forces with hot air from N. Africa or central Spain.

[Frosty.]

Yet again the GEFS 0z screams hot summery potential through late July..really great charts!!!!!

Edited July 12, 2019 by Jon Snow

[Methuselah]

So, here we are, at the middle of next week, and very little difference from what we've seen, this week, methinks: temps a tad above normal, humidity a tad above normal, light winds, lots of cloud and the chance of thundery showers, mostly toward the north...

   

[Frosty.]

The Gfs 6z operational is a very mixed bag of troughs and ridges, there is some very warm fine weather but also a risk of thundery showers also some cooler more unsettled interludes, especially later in the run..in a nutshell it's typical British summer weather!!

Edited July 12, 2019 by Jon Snow

[Frosty.]

The end of the 6z operational may look crap with a trough sat on top of the uk but essentially it's sunshine and heavy thundery showers and feeling a bit humid.

Edited July 12, 2019 by Jon Snow

[weirpig]

1 hour ago, Ed Stone said:

So, here we are, at the middle of next week, and very little difference from what we've seen, this week, methinks: temps a tad above normal, humidity a tad above normal, light winds, lots of cloud and the chance of thundery showers, mostly toward the north...

   

Yep  the mean to that point highlights that perfect   The 6z mean has temps in High res  around low 20s in the south cooler the further north you go   with average precipitation    So  as we enter next week  its looks very similar to this. 

[mb018538]

1 minute ago, Jon Snow said:

The end of the 6z operational may look crap with a trough sat on top of the uk but essentially it's sunshine and heavy thundery showers and feeling a bit humid.

The end of the 6z is the worst you can get for summer - the same low stuck over the UK for 5 days, stuck with nowhere to go. Not likely to happen anyway.

Next week it looks like the low/high will be aligned well enough to to drag all the cool air down - so not too bad.

Your traditional NW/SE split with the best of the conditions towards the SW, cloudier and wetter towards the NW....wet towards Cumbria and the windward side of the Scottish highlands:


 

[weirpig]

Hir res 6z  Ensembles  how how conditions may look like going into next week    (central england)

[Guest]

GFS 06z temps really are incredibly pessimistic holding them back to 18-21c through most of the weekend and even lower (15-16c) in the East Midlands on Monday..... that aside I’m really not sure what to make of the current model output, I just wonder whether low pressure influence  is being over egged just a touch and the south at least could actually quite warm for a while through next weekend.

[Frosty.]

6 minutes ago, Alderc said:

 I just wonder whether low pressure influence  is being over egged just a touch and the south at least could actually be quite warm for a while through next weekend.

You could be right, essentially what I'm seeing is a N / S split beyond the high / ridge.

Edited July 12, 2019 by Jon Snow

[knocker]

This morning's EPS 5-10 mean anomaly does little to contradict the general tenor of the det run

The TPV in the western Arctic with associated troughs either side of the Greenland ridge. Thus still a westerly upper flow across the Atlantic portending an unsettled period of weather for the UK with the usual caveats vis the day to day variation as the airmasses phase, Temps generally a tad above average

In the ext period the upper flow a touch more benign as the subtropical high gains a little more traction in the eastern Atlantic so perhaps period of relatively pleasant weather, albeit tending towards a N/S split

NOAA pretty much in same ball park

 

Edited July 12, 2019 by knocker

[weirpig]

Very little we can take from the ensembles  so much scatter  that the mean will become skewed   what it does show is huge uncertainty in regard to later period  with   some perbs  bringing in BQ weather and other bringing in the next ice age. 

[knocker]

You wouldn't bet on the surface low being that far away by the middle/end of next week

[MATTWOLVES 3]

In all honesty I don't even think the 6z and ensembles are worth the pages they are printed on!! They never seem to have a clue. They just give you several weather types and not any real idea of where the pattern is heading!!! 0c upper air temps on a few runs.... Pull the other one.... It looks to me  a similar pattern next week as to this one. But with perhaps another build of pressure towards next weekend. 

[Frosty.]

10 minutes ago, Mattwolves said:

In all honesty I don't even think the 6z and ensembles are worth the pages they are printed on!! They never seem to have a clue. They just give you several weather types and not any real idea of where the pattern is heading!!! 0c upper air temps on a few runs.... Pull the other one.... It looks to me  a similar pattern next week as to this one. But with perhaps another build of pressure towards next weekend. 

I'm going with a big warm up late July which the GEFS is showing run after run..don't mind if I'm wrong..the weather does what it wants anyway!

[mb018538]

Longer term ECM clusters aren't especially helpful today:



No real sign of anything other than a continuation of what we have now really.

Noaa 8-14 day outlook on the same sort of page:



Meanwhile, the never-ending run of negative NAO continues...nearly at 3 months consecutive:

[Methuselah]

Well, apart from an explosion of uncertainty sometime around next weekend, nothing's really all that different...? If the 06Zs are anything to go by, a major cool-down at the very end of July now looks more likely? Really though, who knows?

   

   

In the mean time, I think we'd be better-off waiting for what the Big Boys say...?

Edited July 12, 2019 by Ed Stone

[Mike Poole]

The Legacy GFS 6z is much more optimistic in the later stages, here at T192, T240, T300 and T384:

The long term models' suggestion of an improvement into August (if summer weather is your thing) will need to be reflected in the operationals at some point, but so far there is no consensus,but this run a good example of what may be possible...we will see...