Model Output Discussion - 1st June 2015 12z--------->

[Steve C]

I hope 'bluearmy' - Chelski fan? is wrong. So easy to predict a non record, even if I think he'll be correct...

[knocker]

I suspect after the hot spell we are looking at wind in the westerly quadrant with a continuing interplay between the HP and LP resulting in variations of the temp, plus and minus, around the mean. With the caveat that Scotland may not benefit too much from the pluses.

[matty007]

This is what the GEFS 12z mean is showing at the moment. So its likely to remain on the warm side even after the main heat has passed.

 

 

Right. That chart looks around 23c to me. Not bad but would like something a bit higher, especially if the winds pick up. 

 

The ingredients for a July 2006 are there, extreme heat on the continent. Just can't see the Atlantic staying away and the Azores becoming strong enough to the East. Even a 2013 repeat would satisfy me but would love a real solid stable heatwave like July 06. 

[stodge]

I disagree with this- yes the SE achieves 30C quite often, but it will be reached over a much wider area than usual on Wednesday. Here in NW England it is not a yearly thing- we managed it a couple of times in 2013 but it has not been common at all over recent summers. There is every chance of it getting above 30C here on Wednesday, and I don't say that too often.

As always., it comes down to where you are, your experiences and perceptions. I do know that in the past it's been hot in London and the SE but, as you say, the plume heads NE across the SE of England and misses Manchester.

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015062812/ECM0-72.GIF?28-0

 

This is a good example off tonight's ECM but the 16c isothem covers all of England and SE Scotland so I do appreciate it could be very warm/hot over a much wider area. 

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015062812/ECM1-72.GIF?28-0

 

But are we talking clear skies and unbroken sunshine or something else ? The HPA tells part of the story - under cloudy, humid skies it could still be warm with the potential for thunderstorms but it wouldn't be hot or very hot as defined.

[Nick L]

I wonder what model they're basing that on? Only NAVGEM is being that bullish at the moment.

 

ECM still shows temperatures probably getting up to 35c in hot spots.

 

Edit: The 12z has cooled it down somewhat, 32c in the SE on Wednesday, add a degree or so for hot spots. Thursday cooler, mid 20s for most. Friday has 30c in places in the south.

Edited June 28, 2015 by Nick L

[Man With Beard]

Goodness me, if tonight's ECM verifies, the July record will certainly go on Saturday. Uppers of 23C over the SE at 1pm on Saturday. Wow!

[Nick L]

Goodness me, if tonight's ECM verifies, the July record will certainly go on Saturday. Uppers of 23C over the SE at 1pm on Saturday. Wow!

 

A few 33's on the map but I don't think that would be enough to take the record.

 

ECM again giving the risk of thunderstorms across the Midlands on Saturday.

 

Edit: My bad, 34c across East Anglia, so who knows?

Edited June 28, 2015 by Nick L

[Nick L]

Incidentally, a risk of strong storms possible on the ECM on Friday night for the SE.

[nick sussex]

Goodness me, if tonight's ECM verifies, the July record will certainly go on Saturday. Uppers of 23C over the SE at 1pm on Saturday. Wow!

I think it depends on whether the thunderstorms get that far east, to have a chance of that record you'd need no rain before then and the very hot plume could still be modelled further east at this timeframe. Any westwards corrections would bring more of the UK into that hot plume and it will last longer. Touch and go at the moment, at least the first plume should deliver that 20c 850 into the UK given that's now modelled within T72hrs.

[Nick L]

I think it depends on whether the thunderstorms get that far east, to have a chance of that record you'd need no rain before then and the very hot plume could still be modelled further east at this timeframe. Any westwards corrections would bring more of the UK into that hot plume and it will last longer. Touch and go at the moment, at least the first plume should deliver that 20c 850 into the UK given that's now modelled within T72hrs.

 

And even way east of the storms, the skies look rather hazy, certainly not gin clear skies.

[East_England_Stormchaser91]

I watched the live discussion featuring Gavin Partridge from Gavsweathervids.com along with some kind of colleague of his. Them two seemed to be saying if the front that will introduce the fresher air is delayed until late on Saturday, then thats what could cause the record to go with a potential for 35-36 degrees odds on. All of the models are not firming up on this though and have the front cleared through by Friday night, which would bring some violent thunderstorms overnight on Friday. 

 

A win win situation if you're like me and like both the heat and storms! 

[stodge]

Looking at the ECM, I suspect Saturday is the day for the really high temperatures given the time the heat will have had to get in place:

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015062812/ECM0-144.GIF?28-0

 

If there's a 35c on offer for London that's where it is.

 

In all fairness, it doesn't last:

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015062812/ECM1-216.GIF?28-0

 

Could still be warm and stormy as the residual heat fades.

[shaky]

ECM still shows temperatures probably getting up to 35c in hot spots.

 

Edit: The 12z has cooled it down somewhat, 32c in the SE on Wednesday, add a degree or so for hot spots. Thursday cooler, mid 20s for most. Friday has 30c in places in the south.

could you post any images mate!!!!much appreciated!!

[Daniel*]

Well the BBC news forecasts are now calling for 35c possible on Wednesday,so any talk of an 'average' 30c looks way out.Possible July record breaker ?

I'd give it roughly 10% chance I do know the models sometimes underestimate the Urban Heat Island effect in urban cities like London. I was predicted 22C by la GFS and the MO it ended up 4c higher.

Edited June 28, 2015 by Daniel*

[carinthian]

Looking at todays temps across Spain and France, a definite heat wave in development. The transfer of the heat plume North Westwards starts tomorrow. Expect temps to reach 40 C in Southern Brittany tomorrow afternoon. Max temps by Wednesday could reach 32C, quite widely across much of England and Wales and a possible 35c is on the cards.

C

[Woollymummy]

("it seems to me that they have succeeded in their aim of dampening down enthusiasm in this thread for what is going to be wonderful spell of summer weather if you enjoy heat and interesting conditions")

I think we are still interested, but the forecast seems to be so certain that there seems little to discuss, and a lot of pre-emptive watering of gardens and making ice-cubes to be done, which is maybe taking up people's time, plus lots of normal "average " temperature summer weekend activities to be enjoyed before we all have to get hot and sweaty at work.

My twopence worth is a question about the next batch of heat: is it possible to look at the lows as they form over USA and work out which are most likely to give us the next extra swirl that flicks some more heat up from Spain. Not that it really matters, I just like to know where they start from.

Edited June 28, 2015 by Woollymummy

[Man With Beard]

Oh I wish there was a Steve Murr equivalent on here during the summer!! (not me, I'm not clever enough)

 

We really need some enthusiasm for this hot spell, after all, this is a board for enthusiasts! We have the 20C 850hpa line visiting us possibly twice this week. Whilst I appreciate the following heatwaves had other factors that made them hot, this did not happen during 1976, 1990 or 2006! In August 2003, it happened on 4 days, and the maxes were 35C (Jersey), 36C, 36C again and then 38C!

 

So getting these uppers is serious stuff - it may not happen again for another 10-15 years - and, so long as it isn't cloudy all day and thunderstorms are dodged (big ifs but very, very possible), it's not going to be your every day heat. Yes, the general maxes might be 34C ish but there will always be little local variations that bring an extra degree or even two into play (or a degree below, for that matter).

 

And just to throw this one out, look at the GFS predicted temperature charts for Friday in France, look at the pressure chart, then imagine the little low over N France (which cuts us off from the super-heat of France on this run) is shallower + later than forecast, and you can only imagine what might happen on Saturday. We may not break the July record, but even if we don't, we'll have been playing with fire in the process.

 

 

 

Enjoy your week, heatwave lovers (and sorry to the heatwave haters!)

[Frosty.]

Well what a superb Ecm 12z we have here, lots of eye candy within the reliable timeframe now, favoured hot spots will reach the low 90's F on a few occasions in the next six days. Lots of hot Sun from the south coast to the northern tip of scotland and an increasing chance of intense thunderstorms.

Best week of the summer so far by a long distance..BBQ weather. The plume comes, it briefly goes but like a boomerang it's back for an encore performance next Friday and especially Saturday..hopefully we won't have long to wait for the next one!

Edited June 28, 2015 by Frosty.

[h2005__uk__]

Maybe I'm being dim, but on the ECM, why are the temps on the "temperature (low)" chart higher than the "temperature (high)" chart? I assumed "high" meant the max in that period?

[bluearmy]

Chelsea Steve? Wash your mouth out!

Anyway, the reason for my opinion on the non record based on several factors, mainly that the onset of the highest uppers is swift and we haven't had a period of high temps to set a conducive background and the start to Wednesday isn't likely to be ultra warm. Flow looks brisk also.

Past couple days, sat has looked the best chance to set the highest temp -mainly due to the v warm to hot background that the high uppers come back in against and a slacker sypnotic picture. Note this IS notable. To see uppers in the region of 20c pushing back in within a day or so of them departing is very rare indeed. So not a bog standard plume event due to the Saturday reload.

Tbh, I'm not certain that Saturday couldn't see the July record broken but for it to go, fri has to be warmer than currently modelled (possible) and Saturday has to deliver long sunny periods (also possible)

Watch this space!

Edited June 28, 2015 by bluearmy

[mushymanrob]

Oh I wish there was a Steve Murr equivalent on here during the summer!! extra degree or even two into play (or a degree below, for that matter).

 

 )

Erm, there are plenty of very knowledgeable posters here in summer.

[Man With Beard]

Erm, there are plenty of very knowledgeable posters here in summer.

I meant his enthusiasm for what could happen, rather than his knowledge.

sorry mods, thought I should clarify

[nick sussex]

Latest French forecast, extreme heat likely Tuesday and Friday. Bordeaux area now expected to hit 41c on Tuesday which could break the French June record.

 

Those two days are seen as the days other regional records could fall. The remaining days still very hot but less chance of any records.

 

For the UK first hot plume 20+ 850 looks very likely, the second one is a lot more uncertain because the margin for error is low at T120hrs with  that plume likely to run more ne ahead of the Atlantic low.

 

Upstream its the low track exiting the eastern USA that could make or break Fri/Sat for the UK, this phases with the eastern Atlantic low this pushes that low ene which forces that hot plume a little too far east. So timing here and where exactly that phasing occurs could make a difference.

[mushymanrob]

I meant his enthusiasm for what could happen, rather than his knowledge.

sorry mods, thought I should clarify

Nobody beats Frosty for enthusiasm, all year round.

[bluearmy]

Going back to the EC 32 debate, the charts we see (even behind a paywall) are very limited. Means and anomolys for weeks 3 and 4 are likely to be vague. The data from ECM contains far more detailed charts that group together varying outcomes etc etc. sadly, very few get to see this.

Knocker kind enough to give you a broadbrush assessment but it's not going to be very helpful for weeks three and four.