Model output discussion 14/04/18

[Singularity]

GFS really arcing the jet back down the eastern flank of our ridge from later Thursday through to early Saturday, as that little low moves into Scandinavia. If it was January we'd be cheering it on, but as it's June, most of us would rather see the other models nail this with the jet heading either N-S (cooler air stays just to our east, potentially staying very warm through Fri-Sun) or NW-SE (cooler air heads nicely away east of us - best solution for sustaining the heat through Friday and the weekend).

 

UKMO has the NW-SE outcome, but as with the 00z it follows this up with a low moving through Iceland that the other models have been keeping NW of there. At +144, this low looks a bit threatening at first glance, but actually, the open door looks to be to it's NE or NNE rather than S or SE, so it shouldn't give E&W much bother, with at least a weak ridge holding on across most or all of the UK. True that Scotland could see something cooler with a chance of some rain, though.

Let's see what ECM gets up to. Given the 12z ICON and GEM runs plus decent 00z EPS support, it would not be surprising to see an outcome similar to the 00z, but there's still enough uncertainty that something different would only be slightly more surprising.

Having reached 25*C here when the global models had 23 or 24*C, I'm still seeing a good chance of hitting the magic 30 at some point in the coming week, and this also looks a true statement for many in Central and Southwest England .

[Frosty.]

5 hours ago, Frosty. said:

The GEFS 6z mean is absolutely superb, it's dominated by high pressure / strong azores ridging throughout and temperatures vary between warm / very warm / hot...the warmest sustained temps further south..

Ditto the GEFS 12z mean..it's fabulous!

[The Eagle]

 

Pity about end of UKMO but ECM more important...

Edited June 24, 2018 by The Eagle

[Captain Shortwave]

The output to Thursday looks pretty solid with plenty of sunshine for most away from northern Scotland where fronts may get close enough to introduce cloud at times, the questions start from Friday onwards.

The GFS keeping developing a stronger NE wind which kills off the heat for most of the UK with only the far west escaping as the low cloud doesn't get that far west. The model however returns a good part of the UK to the mid twenties by Sunday as the surface high returns over the UK.

      

The UKMO doesn't develop this dramatic cool as high pressure is closer to the UK at the end of the week.

   

However the breakdown route is clear to see with a cold front pushing south throughout next weekend, still fine and very warm in the south at day 6.

The GEM

      

Another solution here, similar to the UKMO in keeping the high more UK based at the end of the week but starts to slow that advancing low keeping it west of the UK which keeps us very warm though conditions do become more humid and thundery.

A real mix of solutions here, some would keep the UK fine and hot, some would break things down during next weekend. Lets see what the ECM brings.

[I remember Atlantic 252]

better EC, no Friday shocker on this

[Frosty.]

The Gem 12z is a PEACH!

Edited June 24, 2018 by Frosty.

[shaky]

Brilliamt ecm!!heat all the way up to 144 hours so far!!best of the top 3 models!!

[Craig84]

168 ECM the Iberian Low is moving out west which is starting to waft up hot air from the south again. Great stuff

[Mike Poole]

ECM great at T168:

 

[mb018538]

Fantastic ecm run once again tonight, one for the bank!

[Djdazzle]

T240 chart not good though. Still that’s a long way off and won’t happen in all probability,

[Frosty.]

Gorgeous Ecm 12z with plenty of blue sky sunny days and very warm / hot temperatures..later in the run there's very humid continental air wafting north into southern england bringing an increasing risk of thunderstorms but most of the run looks bone dry and sunny for most or all of the uk under high pressure / strong azores ridging.

[Singularity]

So another vote against the GFS solution for Thu-Sat. Good to see.

Longer-term, it does appear that some Beaufort-Greenland ridging may draw the Azores High away from us for at least a short time, at which point it will come down to how much ridging can hang on independently across NW Europe with troughs tending to stay west of the UK - this is plausible with AAM tendency on the up - something even GEFS is starting to show in its outlook, while CFSv2 remains pleasingly keen;

Certainly a chance of some thundery interludes before AAM makes it into the positive numbers, though (by which time the ridges should start to become dominant again). I imagine many of us with gardens and/or agriculture/livestock to look after will welcome the rainfall from that - but I do worry about the risk of lightning setting of fires both wild and infrastructural.

[Dominic Carey]

What a gorgeous ECM tonight plenty of warm to hot sunshine to enjoy.

[Man With Beard]

That's quite a long heatwave the ECM gives us there. Temperatures up to 26C tomorrow on raw output (so probably around 28/29C from experience), and it pretty much stays there until the end of the weekend, when temps start drifting up even more, and hot weather still not clear even by Wednesday. 

Quite a narrow pathway between cooler air to the north and a plume to the south by the end of the weekend - could easily swing much cooler or even hotter. Am I sounding like a scratched record?

Edited June 24, 2018 by Man With Beard

[Leo97t]

From the look of the ECM. A slight movement in the low would lead to proper Southerly/South-Easterly and really quite extreme temperatures peaking around 2nd-4th July. Watching for a possible upgrade. However exceptional uppers may not be needed to generate high temps with dry ground and pre-existing warmth around. However if the GFS is correct I can see this summer descending quite quickly into a cyclonic westerly. 

[Man With Beard]

Just now, Leo97t said:

From the look of the ECM. A slight movement in the low would lead to proper Southerly/South-Easterly and really quite extreme temperatures peaking around 2nd-4th July. Watching for a possible upgrade. However exceptional uppers may not be needed to generate high temps with dry ground and pre-existing warmth around. However if the GFS is correct I can see this summer descending quite quickly into a cyclonic westerly. 

yep, watching this closely as the positions of these cut off lows often change nearer the time, still possible for that plume to reach us!! 

[Guest]

14 minutes ago, Leo97t said:

From the look of the ECM. A slight movement in the low would lead to proper Southerly/South-Easterly and really quite extreme temperatures peaking around 2nd-4th July. Watching for a possible upgrade. However exceptional uppers may not be needed to generate high temps with dry ground and pre-existing warmth around. However if the GFS is correct I can see this summer descending quite quickly into a cyclonic westerly. 

I agree with your ECM analysis but for me the GFS is being too aggressive and the form horse is continued influence of the Azores high reloading.

Far out enough not to worry about anyway

[summer blizzard]

1 hour ago, The Eagle said:

 

Pity about end of UKMO but ECM more important...

UKMO is the second best global model, you cast it off at your peril (especially if you follow the GFS).

..............

Regarding tonights modeling the short to medium term looks very warm away from east coast incursion however there may be cautious optimism for those of use who want this great early summer done with rather than decending into an opressive humid fest as most later summer spells are. 

Day 10 and 11 so much can change but both the Euro and GFS with a negatively tilted Azores High and the westerlies back.

Tropical signal suggests that after the opening third of July we probably see a lull in any heat with trades strengthening again.

 

[Mike Poole]

And to round off the 12s tonight! here's the ECM ensemble mean at T168 and T240:

I will be looking at the day 10 output in upcoming runs because this mean looks implausibly pessimistic to me.

Here's the 12z FIM9 at T240:

[mb018538]

2 minutes ago, summer blizzard said:

UKMO is the second best global model, you cast it off at your peril (especially if you follow the GFS).

..............

Regarding tonights modeling the short to medium term looks very warm away from east coast incursion however there may be cautious optimism for those of use who want this great early summer done with rather than decending into an opressive humid fest as most later summer spells are. 

Day 10 and 11 so much can change but both the Euro and GFS with a negatively tilted Azores High and the westerlies back.

Tropical signal suggests that after the opening third of July we probably see a lull in any heat with trades strengthening again.

 

https://www.metoffice.gov.uk/mobile/regional-forecast/uk

meto update at 4pm today doesn’t agree, they are still going for fine and settled weather to dominate.

Hard to have any confidence this far out though!

[damianslaw]

Certainly has been a change in things since the SSW - can't help but feel it has had an exceptionally powerful effect on things ever since, atlantic has been preety much dead in the water, with the jet on split course. Hence airstreams from between south and north east have been more dominant than those from a westerly quadrant.

I'm drawing many parallels with events in 1995, which saw a major turn of events in March, with continental airstreams and high pressure ruling the roost thereafter in the main until September. Late June 1995 brought very similiar conditions to what we are about to see. Whether we see an August like 1995 - mmm perhaps not.. 

Back to the models - slight variations a more NE flow looks probable come the weekend, bringing cooler cloudier conditions for the east and south east perhaps, before the ridge re-builds through the UK quickly on Sunday.

I suspect we will see a westerly feed through the first week of July though with lower pressure to the NW becoming more influential - but no signals of a sudden step change from the long wave pattern we have been in since late Feb. I feel overall this summer will end up being the best since 2006 at least. In some years, we've had to wait until well into July before a few days of temps in the mid 20's - not this year, summer came very early in early May. 

[Daniel*]

1 hour ago, damianslaw said:

Certainly has been a change in things since the SSW - can't help but feel it has had an exceptionally powerful effect on things ever since, atlantic has been preety much dead in the water, with the jet on split course. Hence airstreams from between south and north east have been more dominant than those from a westerly quadrant.

I'm drawing many parallels with events in 1995, which saw a major turn of events in March, with continental airstreams and high pressure ruling the roost thereafter in the main until September. Late June 1995 brought very similiar conditions to what we are about to see. Whether we see an August like 1995 - mmm perhaps not.. 

Back to the models - slight variations a more NE flow looks probable come the weekend, bringing cooler cloudier conditions for the east and south east perhaps, before the ridge re-builds through the UK quickly on Sunday.

I suspect we will see a westerly feed through the first week of July though with lower pressure to the NW becoming more influential - but no signals of a sudden step change from the long wave pattern we have been in since late Feb. I feel overall this summer will end up being the best since 2006 at least. In some years, we've had to wait until well into July before a few days of temps in the mid 20's - not this year, summer came very early in early May. 

Do you mean April? 

Highest temperature of year still stands from 19th with 29.1C at St James’ Park it seemed like we did not truly have a spring or a very short one, very much winter to summer, major SSW probable influencer. It’s quire odd too after some really wet months in succession in this part of the world, we have had a run of very dry months. This month is the driest month I can ever remember with likely to finish with under 1mm! Can’t say this year is ‘boring’ for extremes. 

Its a bit tiring folk analysing every run with talk of breakdown when ‘hot’ spell is yet to start in earnest. I’m very sceptical with a true breakdown in the next 2 weeks, it may turn cooler but it’ll likely be warmer than average with HP firmly rooted certainly the best for beyond this spell, for us in the southeast as usual. 

Edited June 24, 2018 by Daniel*

[Cheshire Freeze]

1 hour ago, damianslaw said:

Certainly has been a change in things since the SSW - can't help but feel it has had an exceptionally powerful effect on things ever since, atlantic has been preety much dead in the water, with the jet on split course. Hence airstreams from between south and north east have been more dominant than those from a westerly quadrant.

I'm drawing many parallels with events in 1995, which saw a major turn of events in March, with continental airstreams and high pressure ruling the roost thereafter in the main until September. Late June 1995 brought very similiar conditions to what we are about to see. Whether we see an August like 1995 - mmm perhaps not.. 

Back to the models - slight variations a more NE flow looks probable come the weekend, bringing cooler cloudier conditions for the east and south east perhaps, before the ridge re-builds through the UK quickly on Sunday.

I suspect we will see a westerly feed through the first week of July though with lower pressure to the NW becoming more influential - but no signals of a sudden step change from the long wave pattern we have been in since late Feb. I feel overall this summer will end up being the best since 2006 at least. In some years, we've had to wait until well into July before a few days of temps in the mid 20's - not this year, summer came very early in early May. 

Yes and interesting you mention '95...I asked in the strat thread a few months ago whether the SSW would have a residual impact on the vortex through early winter 2018/2019- I didn't really receive an answer but I read a year or so back that this is possibly what initiated the extremely cold December 2010. I bring this up because winter '95-'96 would fit into the same mould. I also noticed that the averaged CFS pressure anomaly was/is suggesting a December Euro trough...quite unusual from what I've seen over the past few years for that particular version of the CFS model.

Also...apologies for being OT but could this potentially be one reason towards why cold winters come in clusters??

Edited June 24, 2018 by CreweCold

[shaky]

The 18z is a pretty big change when you compare it to the same time frame from the 00z for saturday morning!!pressure is 5mb stronger and centred across the uk!!this mornings run had the pressure lower and losing its grip from the northwest!!slowly coming around the ecm if you ask me!!massive change compared to earlier especially for the weekend!!heat continues for england and wales and we bring in hot air from continent once again!!

Edited June 24, 2018 by shaky