Arcus
16 July 2019 20:39:49

Originally Posted by: Shropshire 


 


The set-up is dependent on the lower pressure anomaly West of Iberia, far from certain to happen and the Atlantic low being further East and South is the likelier scenario.


 



Like the previous pseudo-plume, I would also be very cautious on extrapolation of T2s from the 850s when the flow is not SSW/S. The anomaly you mention would correlate to a heat low - which is what scuppered high temps due to excessive cloud cover over the UK.


Ben,
Nr. Easingwold, North Yorkshire
30m asl
Brian Gaze
16 July 2019 21:01:47

Not sure if already posted but the CMC 12z is showing 37C in East Anglia next Wed.



Brian Gaze
Berkhamsted
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Downpour
16 July 2019 22:03:38

Originally Posted by: RobN 


MO looking increasingly toasty next week in the south.


Let us hope the rain forecast over the weekend is delivered else gardens and crops will get some serious stress by the end of next week.



Friday’s system needs a direct hit here. My lawn is turning to bloody straw. Was out watering it yet again earlier.


Chingford
London E4
147ft
TimS
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16 July 2019 22:13:53
Just to keep us on our toes tonight’s GFS 18z looks like it’s bringing a transient heatwavelet with maxes possibly getting to 30C for a day or two before the Atlantic returns. So it remains very unpredictable.
Brockley, South East London 30m asl
DEW
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17 July 2019 06:19:54

Originally Posted by: TimS 

Just to keep us on our toes tonight’s GFS 18z looks like it’s bringing a transient heatwavelet with maxes possibly getting to 30C for a day or two before the Atlantic returns. So it remains very unpredictable.


And still unpredictable this morning


ECM and GFS control (from the ensembles) if you want a full on heatwave at the end of next week


GFS 0z ad GFS op if you want the hot air to brush past and finish up in Lapland (the GFS op for Brighton is actually below average for the end of July)


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Chichester 12m asl
TimS
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17 July 2019 06:33:21
GEM incredibly hot this morning, GFS op a big outlier, and UKMO looking decent. But the margins are very tight here hence the spread. It’s a potential heatwave being driven by low pressure to the West rather than high pressure. Small tweaks could shift things significantly either way.
Brockley, South East London 30m asl
xioni2
17 July 2019 06:42:15

EC 00z op run very hot for next week, with 30s every day and mid-30s already from Tuesday.

xioni2
17 July 2019 06:56:12

Originally Posted by: xioni2 


EC 00z op run very hot for next week, with 30s every day and mid-30s already from Tuesday.



This run would produce 35-38C during Tue-Thu (hottest Wed & Thu).

Heavy Weather 2013
17 July 2019 07:47:01

Would be good to see GFS come into line over the next 24hrs.


It should be noted that even though the OP was an outlier, there is support in the ensembles for a heatwave.


Bit of a rain event contend with on 20 July. 


I have a feeling this could be the big one. I remember in 2003 the big heatwave was preceded by a rain event.


Mark
Beckton, E London
Less than 500m from the end of London City Airport runway.
Brian Gaze
17 July 2019 07:55:43

Logic suggests ECM 00z was for the bin.


https://www.theweatheroutlook.com/twodata/ecmwfens.aspx?run=00&lg=850&lglocation=london


Hunch suggests it is something to watch. Ensembles can sometimes lag IMO.


 



Brian Gaze
Berkhamsted
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TimS
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17 July 2019 08:38:27

Originally Posted by: Brian Gaze 


Logic suggests ECM 00z was for the bin.


https://www.theweatheroutlook.com/twodata/ecmwfens.aspx?run=00&lg=850&lglocation=london


Hunch suggests it is something to watch. Ensembles can sometimes lag IMO.


 




It does feel a bit about hunch at the moment. Too knife edge. Contrast with the June heatwave which (for France at least) was accurately programmed over a week in advance and really didn't change much. But that was high pressure driven and involving a Tc airmass, this is low pressure driven involving a Tm heat-pump.


An interesting comparison is the mini heatwave of mid July 2003 (12-15th). Remarkably similar buildup, and remarkably similar breakdown to that shown on the less settled ensemble members (and the GFS op). Run the reanalysis to see what I mean. I remember the buildup- there were runs a few days before indicating 20C uppers and record beating temperatures. I was heading off to France in the middle of it too. But in the end it was a 3 day wonder and we had meh weather for the rest of the month before the August heatwave.


Brockley, South East London 30m asl
xioni2
17 July 2019 09:55:00

Originally Posted by: Brian Gaze 


Logic suggests ECM 00z was for the bin.


https://www.theweatheroutlook.com/twodata/ecmwfens.aspx?run=00&lg=850&lglocation=london


Hunch suggests it is something to watch. Ensembles can sometimes lag IMO.



Not just sometimes, but fairly often. And obviously the EC op run has more skill than the ens mean up to days 6/7 now.


Last time the EC op runs got spectacularly right the setup 7 days in advance (including the low surface temps with the extremely high T850s), but obviously this was a different setup and the model benefited not just from its higher horizontal resolution (global inputs), but also from its higher vertical resolution (local impacts).


This is a different pattern with different uncertainties (the ridge could be further northeast with more troughing near the UK). I don't think we can have high confidence yet, but I would definitely be warmer than the EC ens mean (which keeps trending warmer anyway).


 

Rob K
17 July 2019 10:11:03

One run breaks the 25C mark on the 00Z GFS! And not long afterwards, another run dips to about 1C...


 



 


 


At 2m, the range on July 25 for central southern England is from a max of 17C to a max of 35C!


 


Yateley, NE Hampshire, 73m asl
"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome
Rob K
17 July 2019 10:16:51

Originally Posted by: xioni2 


EC 00z op run very hot for next week, with 30s every day and mid-30s already from Tuesday.




ECM raw output has 37C for the Oxford area on Thursday.


 


https://weather.us/model-charts/euro/buckinghamshire/max-temperature-6h/20190725-1800z.html


 


 


Yateley, NE Hampshire, 73m asl
"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome
TimS
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17 July 2019 10:23:18

Looks like GFS 06z is going for the hat trick and denying us thrice, with very similar breakdown to both 18z and 00z. Doesn't want to know. I fear this time it may not be such an outlier, but we'll see.


Brockley, South East London 30m asl
picturesareme
17 July 2019 10:44:05

Originally Posted by: TimS 


Looks like GFS 06z is going for the hat trick and denying us thrice, with very similar breakdown to both 18z and 00z. Doesn't want to know. I fear this time it may not be such an outlier, but we'll see.



Denying what exactly??? Certainly not heat on the 00z!


 


 

Rob K
17 July 2019 11:08:36

Originally Posted by: picturesareme 


 


Denying what exactly??? Certainly not heat on the 00z!


 


 



 


The 06Z op run only gives us a very brief waft of high uppers. Let's wait for the ensemble though.


Yateley, NE Hampshire, 73m asl
"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome
picturesareme
17 July 2019 11:13:05

Originally Posted by: Rob K 


 


 


The 06Z op run only gives us a very brief waft of high uppers. Let's wait for the ensemble though.



He's not talking about heat he can't be as you can  read in the post questioned he talked of 00z and they are the ensembles for 00z. They show a clear sustained week of heat (high 20's - low 30's).

TimS
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17 July 2019 11:16:49

Originally Posted by: picturesareme 


 


He's not talking about heat he can't be as you can  read in the post questioned he talked of 00z and they are the ensembles for 00z. They show a clear sustained week of heat (high 20's - low 30's).



I’m talking about op runs. 2 in a row that were cool outliers compared with ENS, and then a third unsettled op which I feared might not this time be an outlier (but actually looks like it is, again). 


Hence thrice denied. Hot ensembles are nice but it’s better to have a hot op run too.


Brockley, South East London 30m asl
Brian Gaze
17 July 2019 11:49:46

Something for everyone.



Brian Gaze
Berkhamsted
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