Model output discussion - hot spell beckons but then what?

[MP-R]

1 hour ago, I remember Atlantic 252 said:

hope we have a similar to Sept 2011, certainly more likely than in Aug

Exceptional yes, but keep in mind that this happened in the closing 3 days of the month, which until then, was very unsettled. 

   

Tentative signs of a more settled and more typically August-like final third to the month with a slightly more meridional jet to between now and then. I suppose as we get nearer the end of the month, with the Atlantic up a notch, it won't take long for the typical N/S split to appear, edging south with time. That's all a very long way off however, and I hope to see at least one settled spell this month before I go away on the 28th.

[SMU]

I just wanted to throw this in the MOD as a couple of people suggested what I recorded in my winter forecast thread was wrong-

'Super intense High pressures' now migrating to polar regions creating extreme modes of teleconnections-

Greenland has just recorded its highest Geopotential height on record... 

Relating to seasons expect more of the same soon..

Edited August 12, 2019 by Steve Murr

[Methuselah]

Not a bad end to the 12Z at all. But it's still a very long way off!

   

And the ensembles show a sustained rise in SLP post Day 7. So it's getting closer!

   

   

                              

[Frosty.]

I think the longer term GEFS 12z mean deserves a round of applause the way it recovers from its nadir in approx 1 weeks time and eventually brings back summer during late august..which would hopefully continue well into september!!!..   much caution is needed of course but the longer term signal from the GEFS has been for a BIG improvement for a while now and this clearly shows that!!

 

 

 

Edited August 12, 2019 by Jon Snow

[inghams85]

53 minutes ago, Steve Murr said:

I just wanted to throw this in the MOD as a couple of people suggested what I recorded in my winter forecast thread was wrong-

'Super intense High pressures' now migrating to polar regions creating extreme modes of teleconnections-

Greenland has just recorded its highest Geopotential height on record... 

Relating to seasons expect more of the same soon..

Very impressive that Steve but do you mind me asking what it was you saw with the set up that made you think this would happen. Purely educational for me if you don't mind

[SMU]

37 minutes ago, inghams85 said:

Very impressive that Steve but do you mind me asking what it was you saw with the set up that made you think this would happen. Purely educational for me if you don't mind

 

That was the winter thread 2018/2019 you can see at the start where showed some examples of these intense high pressures ( probable record breaking ) 

Most importantly in the grand scheme of winter they are part of the reason of why the modes of the NAO / AO become more extreme because these super highs are creating greater anomalies - this creates stronger WAA & CAA

This means the warm penetrates further North & the cold can penetrate further south- These highs are becoming more frequent in appearance ....

The most classic ( intense )high that impacted the UK for cold & one from last Winter....

[inghams85]

53 minutes ago, Steve Murr said:

 

That was the winter thread 2018/2019 you can see at the start where showed some examples of these intense high pressures ( probable record breaking ) 

Most importantly in the grand scheme of winter they are part of the reason of why the modes of the NAO / AO become more extreme because these super highs are creating greater anomalies - this creates stronger WAA & CAA

This means the warm penetrates further North & the cold can penetrate further south- These highs are becoming more frequent in appearance ....

The most classic ( intense )high that impacted the UK for cold & one from last Winter....

Thanks Steve

[stodge]

Evening all

Signs of more settled and warmer conditions later in the month which is something we often see in the UK.

Having a look at the Northern Hemisphere profile from the GFS 12Z, it seems the heights over Greenland are broken down quickly by what seems to be an ex-Pacific typhoon which heads through the Bering Strait and its energy invigorates the formation of LP across the very north of Canada and NW Greenland which brings colder air across Greenland and triggers a drop in heights allowing ridging from the Azores to trend NE across western Europe.

This is one aspect of how tropical weather systems influence weather patterns at higher latitudes. We see it with Atlantic hurricanes but I've long thought extratropical systems from the Pacific moving into cooler waters must also have an impact.

I think this explains why we often get decent weather in September and early October because the tropical systems are at their strongest, the PV has not yet formed and the jet is often weak or prone to amplification.

[Lincs Observation]

4 hours ago, Jon Snow said:

I think the longer term GEFS 12z mean deserves a round of applause the way it recovers from its nadir in approx 1 weeks time and eventually brings back summer during late august..which would hopefully continue well into september!!!..   much caution is needed of course but the longer term signal from the GEFS has been for a BIG improvement for a while now and this clearly shows that!!

 

 

 

Good job too as we need that jet as far north as possible due to the hurricane forecast for this year to be particularly active, the last thing we need is a southerly jet allowing ex hurricanes to track across and barrel towards the Uk. I think we are expecting the first depressions to start forming in the next few weeks.

[Methuselah]

Plenty of cause for optimism from this morning GFS 00Z:

   

 

And the GEFS 00Z ensembles:

   

   

So, hopefully, some time for rain-soaked areas to dry out?

[Guest]

7 minutes ago, Ed Stone said:

Plenty of cause for optimism from this morning GFS 00Z:

   

 

And the GEFS 00Z ensembles:

   

   

So, hopefully, some time for rain-soaked areas to dry out?

Really? Very little to be optimistic about unless your getting on a plane to Cyprus, any warm up is over ten days away! Between now and then GFS has at least 4 varying depths of low pressure to swing across the Uk anchoring is in a dreadful and continuous stream of cloud and fronts, hard to see August being anything other than another poor like so many of the previous 15. 

[Weather-history]

19 minutes ago, Alderc said:

Really? Very little to be optimistic about unless your getting on a plane to Cyprus, any warm up is over ten days away! Between now and then GFS has at least 4 varying depths of low pressure to swing across the Uk anchoring is in a dreadful and continuous stream of cloud and fronts, hard to see August being anything other than another poor like so many of the previous 15. 

Edited August 13, 2019 by Weather-history

[Summer Sun]

After a very unsettled end to this week 00z ECM is showing a steady improvement next week could be perfect timing with the bank holiday coming up for England, Wales and Northern Ireland

[mb018538]

Finally - a bit of light at the end of the tunnel? It’s been much talked about, but could be happening....the trough lifting out through next week to be replaced by something drier and warmer for the last week or so of summer. One to watch.

[Frosty.]

Looking at the longer term Ecm 0z operational / ensemble mean...there's a change for the better on the way next week and hopefully beyond!

[summer blizzard]

Both GFS and Euro this morning now in agreement that ridging will take over from day 9 (should be a good Surinam range at least initially).

Some suggestions bourne out by the GFS that the center of the high May stay west allowing low pressure to the east though the Euro looks more sustainable.

[Man With Beard]

EC clusters: Improvements start to kick by around 22nd August. Larger improvements likely by 25th August. Becoming a theme on the clusters:

  

Maybe we can squeak out a little more summer before time is up.

[smichling]

I'll be going out to Reading festival this bank holiday weekend and I'm praying for good weather after last year was cold and wet despite what the rest of summer 2018 was like! What are my chances like of some heat and staying dry? 

[Singularity]

The propagation across of changes from the tropics is now clear to see in the ensembles. Hopefully there won't be any tropical cyclones to mess with the transition by introducing sudden amplification where it wouldn't otherwise occur.

Landing point for more dry than wet weather looks to be 22nd or 23rd. Just in time to qualify as a transition for the final third of the month. Here's hoping we can get a good ridge alignment too, akin to the 06z FV3.

[Frosty.]

The GEFS 6z mean again shows a strong signal for high pressure during late August which would be great news for the BH weekend and there are some very summery members.. I would gladly accept P2..hope to see more of these in the coming days!!

Edited August 13, 2019 by Jon Snow

[Methuselah]

Well, hopefully this'll be the last deep Atlantic depression we'll see for some time...But, given that today's temps (around 21C) have been some 2C higher than anyone forecast, Friday and Saturday look interesting: 19-20C and 70% RH? Or will some lucky locations, to the east of high ground, exceed 24C? Who knows?

   

And, thanks to all the teleconnection folk ('teleconnectionists' makes them sound like a clandestine CIA-backed telepathic hit-squad, so my apologies for that.) for seeing the upcoming improvements so far ahead of time...

[MATTWOLVES 3]

1 hour ago, Ed Stone said:

Well, hopefully this'll be the last deep Atlantic depression we'll see for some time...But, given that today's temps (around 21C) have been some 2C higher than anyone forecast, Friday and Saturday look interesting: 19-20C and 70% RH? Or will some lucky locations, to the east of high ground, exceed 24C? Who knows?

   

And, thanks to all the teleconnection folk ('teleconnectionists' makes them sound like a clandestine CIA-backed telepathic hit-squad, so my apologies for that.) for seeing the upcoming improvements so far ahead of time...

I agree with you there Pete.. The EC46 had been hinting at these improvements for the last couple of weeks... Regarding last night's run we see an improvement from as early as next Tuesday, Plenty of ridging from the S/SW... This pattern looks like holding into mid September, so for once the EC46 deserves a bit of credit.... Not so sure about its projections for October.. November and December though... It shows a warmer than average scenario... So I'm hoping it's gonna be wide of the mark.... 

[SMU]

Another stratospheric flash message relating to the zonal mean-

Second day on the trott where the record has been broken in terms of negativity ...

The current trajectory suggests a date record for 'latest start to the season for the polar vortex ....'

[Mapantz]

Can we please keep posts to the relevant threads? There's dedicated threads for stratospheric discussion.

Thanks.

[Methuselah]

Today's GEFS 12Z ensembles point toward a sustained rise in SLP, and a more erratic increase in T850s:

   

   

But thankfully, as my prickly heat has only just gone, there are no signs of a return to sweatbox conditions!