Model output discussion - summer rolls on

[tight isobar]

2 minutes ago, Steve Murr said:

ECM moving the heat dome from spain 192 > 216 > 240

20c not far away for Sat 4th

just based on ECM 12z 216 /240 we will be 30c ISH day 9 & low to mid 30s Day 10

Im earmarking the 5th & 6th as possible record breaking dates...

100% with you on that quote!!

 

[Djdazzle]

22 minutes ago, stodge said:

Evening all

Have to say it looks like a step or two back from the heat-topia of earlier runs. Thursday and Friday this week look hot for the SE and certainly 33c looks likely but a significant breakdown through the weekend with much cooler air pulling temperatures back to a much more agreeable 25c or so.

The end of next week remains in low-res so forecasting very difficult - the signs for a new thrust of heat north from Africa and Spain across France are clear but from previously looking as though Friday 3rd would be the climax of the heat with the 20c 850 crossing England, it now seems to be Sunday 5th and Monday 6th which could be the hottest days but the 20c 850 doesn't quite make it before the Atlantic pushes cooler air back in. This is from the 12Z GFS OP - the 06Z parallel was underwhelming but the 12Z Control kept the heat through to the end of the week after next especially, oddly enough, in the SW.

More runs are needed but I don't see records in danger just yet.

 

 

 

Well the GFS and ECM are actually both showing the potential for significant heat around day 9-10, which in itself is something unusual. I know it's FI, but if anything the 12z runs have shown a step or two TOWARDS extreme heat.

Not to mention the 35C+ in the SE this week!

[Evening thunder]

8 minutes ago, Captain Shortwave said:

Struggling to see where the rain will be coming from on the UKMO though???

Weak ridge building in Saturday (SW England driest)

Sunday has a weak ridge through the UK, a few showers at best.

Also I guess given how different the UKMO is from Sunday onwards it is hard to make a clear conclusion for the following week, I would add that the GEM evolution is very different to the ECM/GFS as well as it disrupts the trough to a point where a low sheers off south east over the UK as opposed to the low positioning itself to the NW of the UK.

ECM from the weekend is hardly heading towards a summer washout, just a bit closer to average though probably still on the warm side.

True for the UKMO perhaps having looked again, admittedly I read this as a shallow low over the south (did look like one on WZ) 


I feel it would be hard to avoid the cool air after that T+144 chart though
GFS gives me rain and ECM looks more likely to for me

Yes hardly a bad run just a trend for more unsettled influence, my thoughts are it would probably only be above average in the East/SE on Saturday/Sunday and Tuesday/Wednesday.

[Guest]

14 minutes ago, Luke Best said:

And that's a 20% chance of the all-time UK record being broken!!! 

30% chance of the July record being broken, according to the Met O's Chief Forecaster. 

So a far more probable 70-80% chance it won’t. 

[shaky]

Right so i have just taken a look at the precipitation charts and apart from fridays thunderstorms which will also be hit and miss the weekend actually sees very little rain if any at all across england!so although the weekend looks really low pressure dominated there is hardly any rain so make the most of the rain on friday!!also temps look mod twenties at the weekend so still really warm!!

[mushymanrob]

todays noaa 500 mb  8-14 day chart, and it continues the evolution previously suggested... imho its a completely sound consistent evolution. the atlantic trough weakening and sitting more over the azores whilst the scandinavian/northern european high retrogresses towards us.

this can only mean more lengthy spells of heat, and a roasting start to august must be a distinct possibility. the ecm and gfs are hinting at severe heat over spain shifting northwards for this time period. i expect some 'roasting runs' to start to firm up for early august.  of course this is not a 'given' , nothing is, but id be very suprised if the noaa's were far from correct or as near as damnit! 

Edited July 24, 2018 by mushymanrob
forgot chart

[Ice Day]

Evening all.  A daily visitor but rare poster during the summer months, but this spell has forced me in here.  This on Friday at 2:00pm with 14c uppers across the spine of the country and 18c across Kent and East Anglia.  Friday is going to be a furnace in these areas, however I suspect we'll come up just shy of the all time record (36.5c is my guess).

I can't believe I'm saying it, but a cool and wet weekend would be most welcome but I'm not convinced we'll see much rain down here in the south east.  

[Rob K]

34 minutes ago, Luke Best said:

And that's a 20% chance of the all-time UK record being broken!!! 

30% chance of the July record being broken, according to the Met O's Chief Forecaster. 

If it's a 20% chance of 38.5C being broken then surely the chance of 36.7C being broken would be a lot higher than 30%!

[Guest]

20 minutes ago, Alderc said:

So a far more probable 70-80% chance it won’t. 

Alright we’re not all mathematicians you know

[SMU]

Just adding one more point to the discussion-

Why are we talking records being broken next weekend-?

We are looking at about 36/37 degrees in the Extreme SE on Friday with a slither of upper air temp @18c- The original core heat over spain was maxed out at 21/22c - which in truth isnt 'that' hot for them - ( probably average spanish uppers )

 

Now move forward 10 days & the plume thats potentially developing for the UK actually develops North out of Africa with uppers bordering 30c (192 )

This is like cold pooling in winter - with the +30c line being like the -26c line getting towards Berlin.

This moves North & modifies as it does but the size of the heat bubble proper trumps this week - *IF* this alligns Northwards out of Africa > Spain > North to UK & we get the 21c isotherm over the sea we will break the record. 100%

S

 

[bradymk]

Whatever the scenario showing up in the op runs for the weekend, it seems we end up with the same result 10 days time regardless

Certainly the potential to get very hot end of next week and more widespread across the UK too.

And that’s of course after the possible 35/36c heat in the south east thurs/fri.

 

[Frosty.]

The Ecm 12z ensemble mean has a happy ending with high pressure and increasing warmth from the south.☺

[Mike Poole]

ECM mean at T240, a fine weather lover would take this any day in summer, no? 

[Captain Shortwave]

   

Looking decidedly omminous going forward as we move into August. I am not one for posting charts from the past but the set up on show here is pretty much identical to how a certain heatwave fifteen years ago initiated.

Declining Scandi ridge, heat building strongly over Iberia and southern France, a weak Atlantic trough which will build the ridge sufficiently over the UK without pushing too far north. It might and probably will not happen in the same manner it did in 2003 but there are some serious warning signs as we head into week 2. 

Anyway lets get the rest of this week out of the way before we think about another heatwave, mainly as the models struggle to consistency model a rather deep Atlantic trough against an extremely strong ridge to our east.

Edited July 24, 2018 by Captain Shortwave

[Frosty.]

Both the Ecm 12z op / mean end beautifully poised with all that heat across spain / france heading north..what an August we could be in for!☺

[ANYWEATHER]

I really see the Atlantic in play in the next week , the So Called heatwave is on the way out as we get into August.......Baby steps now, Just watch this Space...Enjoy the heat folks if you like it because its on the way out...Big pattern change come August...

[Nick L]

3 minutes ago, ANYWEATHER said:

I really see the Atlantic in play in the next week , the So Called heatwave is on the way out as we get into August.......Baby steps now, Just watch this Space...Enjoy the heat folks if you like it because its on the way out...Big pattern change come August...

Despite virtually all EPS and GEFS ensembles showing temperatures remaining above average for the next 2 weeks. Nice try.

[MattStoke]

3 minutes ago, ANYWEATHER said:

I really see the Atlantic in play in the next week , the So Called heatwave is on the way out as we get into August.......Baby steps now, Just watch this Space...Enjoy the heat folks if you like it because its on the way out...Big pattern change come August...

Shame none of the model output, ensembles, teleconnections or professional forecasters agree with that. A couple of op charts clearly set the pattern for an entire month though.

[Djdazzle]

7 minutes ago, ANYWEATHER said:

I really see the Atlantic in play in the next week , the So Called heatwave is on the way out as we get into August.......Baby steps now, Just watch this Space...Enjoy the heat folks if you like it because its on the way out...Big pattern change come August...

Just a suggestion - if you are calling a pattern change for August, it might be an idea to post some charts for August, not July. You seemed to have ignored what happens after those charts, which certainly do not suggest a pattern change.

Edited July 24, 2018 by Djdazzle

[Singularity]

Longer-term heat aside, I'm genuinely in shock at the ECM 12z run for this coming Sunday through Monday.

A brisk southwesterly wind with a few showers and temps struggling to make it into the 20s away from the southeast? Where the use your imagination here did that come from?

In a bid to answer that - it seems that with the plume edged a bit closer on Friday, the model sees this as a means to ramp up a short section of westerly jet across the UK, which allows the Atlantic trough to extend eastward in a way that had previously looked extremely improbable. The message has strongly been one of fronts only gradually advancing east during Sat-Mon, overall weakening but with the chance of some pulses of heavier rain such as the GFS 12z shows. Ahead of it, low-mid 20s are widespread, and even as the remnants cross on Monday, they're too weak to lower the maximums much.

What with that and the much more gradual, stuttering option put forward by UKMO, the ECM solution is the last thing I expected to be viewing this evening.

 

Honestly, it makes me despair at the state of computer modelling despite so much work going into it, but never mind, all we can do is focus on the bigger picture until the models sort the weekend progression out. Though even that looks a bit wonky on the ECM 12z in terms of ridge placement etc - my opinion of the model has declined quite a bit this year but at the moment it does - as far as the longer-term goes, not the weekend, that's just mayhem going on there - have the excuse of being totally confused about the MJO propagation - today the observed was another step closer to P7 and another increase in amplitude, in contrast to the EPS mean which strongly supported a stall and weakening.

 

p.s. If you enjoy irony - the ECM 12z rainfall totals are actually a little lower for central parts of England than the GFS 12z totals due to the front and showers moving through so fast. 

[Mike Poole]

Here's the FIM9 12z At T240:

All that red has got to lead to real heat, no? 

And to cap it off the Met Office contingency planners forecast give 55% probability to their hottest category. Roll on the incredible summer of 2018 

[terrier]

21 minutes ago, Frosty. said:

Both the Ecm 12z op / mean end beautifully poised with all that heat across spain / france heading north..what an August we could be in for!☺

Well I’m in Spain as we speak until the 14th of August frosty. Trust me it’s hot. And looking at the ecm it’s heading straight for the U.K. shores aswell enjoy. Hopefully it will still be around on my return. 

[Rob K]

37 minutes ago, Captain Shortwave said:

   

Looking decidedly omminous going forward as we move into August. I am not one for posting charts from the past but the set up on show here is pretty much identical to how a certain heatwave fifteen years ago initiated.

Declining Scandi ridge, heat building strongly over Iberia and southern France, a weak Atlantic trough which will build the ridge sufficiently over the UK without pushing too far north. It might and probably will not happen in the same manner it did in 2003 but there are some serious warning signs as we head into week 2. 

Anyway lets get the rest of this week out of the way before we think about another heatwave, mainly as the models struggle to consistency model a rather deep Atlantic trough against an extremely strong ridge to our east.

Looking at the charts from Aug 2003 I'm amazed that we didn't go higher than 38.5C. There were >20C 850s for several days, peaking at 22C. The charts are showing 36C possible on Friday with only 18C at 850.

I assume there has to be a chance of the record even with upper air temps a couple of degrees lower than 2003, as we have had such prolonged dry weather (although showers on Fri could dampen the soil somewhat)

[Rocheydub]

26 minutes ago, ANYWEATHER said:

I really see the Atlantic in play in the next week , the So Called heatwave is on the way out as we get into August.......Baby steps now, Just watch this Space...Enjoy the heat folks if you like it because its on the way out...Big pattern change come August...

I thought the pot stirrers were only out in force in the winter months... I was obviously wrong. These charts are July, not August for a start! The rest of the post is just poppycock!

[markw2680]

34 minutes ago, ANYWEATHER said:

I really see the Atlantic in play in the next week , the So Called heatwave is on the way out as we get into August.......Baby steps now, Just watch this Space...Enjoy the heat folks if you like it because its on the way out...Big pattern change come August...

Clearly you have done this for a reaction because as far as I can see there certainly isn’t a big pattern change coming at all in the near future, in fact I can’t even see much in the way of rain for the next couple of weeks at least either sooo....