There are some quite consistent early warning signs for what would be a historic, probably record breaking and certainly dangerous heat dome forming over the central Med from Tunisia through Italy up to the Balkans, starting this weekend, peaking the following weekend and lasting until at least early July.

Data based on GFS output but a similar pattern is showing in ECM, albeit with a few nuances. It's been showing up for a number of runs in a row which makes me fairly confident there is a real risk here.

We're looking at a stuck jet stream pattern with a trough over Ireland and strong and persistent ridging in the central Med. Here's how it develops synoptically:

1. The subtropical jet pumps up, driven by troughing in the North Atlantic, and starts to arc over Italy:

2. A (rare) summer version of a Bartlett / Euro high develops over the Alps, extending unusually high pressure over the central Med which would usually be hovering around 1010-1015hPa after the solstice

3. This drags up VERY hot Saharan air from Algeria and Tunisia, and it then stays there for days and days, slowly spreading North-Eastwards towards the Balkans. 

The intense heat starts early next week in Tunisia, Sicily, Sardinia and the Mezzogiorno.

But it really gets going further North later in the week. The daytime values are frightening, e.g. 45C in the Po Valley, Inland Sardinia, Serbia (peaking at 46C the next day)

Parts of Southern Italy reach >40C daily for 14 days (and are still going at the end of the run).

Night minima widely from 27-30C in coastal areas too, which is murderous:

This is one to watch. To avoid this we need the jet to flatten and ridge a little over the UK and to our North East, which will bring us better weather and suppress the heat dome in the Med too.  

That looks brutal. 

Sooner or later it will be our turn maybe this year?

That looks brutal. 

Sooner or later it will be our turn maybe this year?

 

Want that to see it happening here, it need to experience extreme heat for days and days not 1 day nonsense, no use to that and waste of time.  With the strong heat UK cannot avoid forever.  With last Friday Nuneaton reached 31C and London 32C so it make me wonder that being in right in middle of Midlands how well we get the heat if this come up? London 41-42C and Nuneaton 39-40C? Leeds and York 37-38C?  York was 29C last Friday so that the highest temps and far north than here.

 

Want that to see it happening here, it need to experience extreme heat for days and days not 1 day nonsense, no use to that and waste of time.  With the strong heat UK cannot avoid forever.  With last Friday Nuneaton reached 31C and London 32C so it make me wonder that being in right in middle of Midlands how well we get the heat if this come up? London 41-42C and Nuneaton 39-40C? Leeds and York 37-38C?  York was 29C last Friday so that the highest temps and far north than here.

It will happen in your lifetime, I’m pretty sure of that.

However, I really don’t want to see this one happening in the central Med. Just too brutal and dangerous. The good news is that anything which improves our weather will weaken the heatwave: either the trough remains further West and pressure rises over NE Europe (as hinted on tonight’s GFS) which spreads the heat out further but thinner, or the trough blasts through quickly then pressure builds right over us (as implied in this evening’s ECM) which punctures the heat dome completely.

 

It will happen in your lifetime, I’m pretty sure of that.

However, I really don’t want to see this one happening in the central Med. Just too brutal and dangerous. The good news is that anything which improves our weather will weaken the heatwave: either the trough remains further West and pressure rises over NE Europe (as hinted on tonight’s GFS) which spreads the heat out further but thinner, or the trough blasts through quickly then pressure builds right over us (as implied in this evening’s ECM) which punctures the heat dome completely.

Cyprus had brutal hot 2 summers but this year a lot cooler and now on average and no 40 yet, when in 2020 was 59 times hitting 40 and over. Nearly July and no signs of that.  I agreed about mid Med too hot because it bottled up at the moment but should not be long time and spread our to other places and here some often decent warm to hot days for rest of summer. 

Oh, jesus. We're off to Malta a week Friday (1st July) 

Thankfully the hotel room has air con and there's a pool. 

I think I'll live in the pool. 

Oh, jesus. We're off to Malta a week Friday (1st July) 

Thankfully the hotel room has air con and there's a pool. 

I think I'll live in the pool. 

Don't  forget safety  first 

https://m.media-amazon.com/images/I/618su3fEjpL._AC_SX679_.jpg

High of 43C tommorow in the south.

This is going to be exceptional. We are looking at a week where everyday sees 40C+

By the weekend 45C+ looks likely in the south and scicily.

These are the places to watch. The wind will be quite variable but usually coming from that southern half. And since it could be fairly moist at times coming off the med, we could see some foehn effects. Foehn + very hot airmass means the circled areas have the best chance of breaking records.

High of 43C tommorow in the south.

This is going to be exceptional. We are looking at a week where everyday sees 40C+

By the weekend 45C+ looks likely in the south and scicily.

 

The latest runs show the heatwave more constrained in space (further South and not such extreme heat up into Serbia and Croatia), and not quite as intense as before. It's been saved a little by modelled pressure rises over NE Europe which shift the centre of the descending air a little. But it'll still be blisteringly hot for an extended period.

Highest values on Italian mainland and Islands in this morning's 06z GFS up to next Sat:

40, 41, 41, 40, 41, 43, 44, 42, 41, 41, 41

Bear in mind when I started this thread we were seeing modelled maxes of 46-48C in NE Italy and Serbia. So if this heatwave makes the news it's worth thinking what it might have been if the pattern had been a little different. 

Keep us informed Tim - Seriously interesting this is.

Keep tabs on this Tim. What are things like atm.

The heatwave now looking a little more intense again, but with an end point next weekend as high pressure builds over Western Europe. The most intense heat generally in the South but quite widespread across mainland and islands, and creeping into the Baltics.

Max temps in Italy per today's GFS 06z (similar to last few runs), from today:

41 (Sicily), 40 (Sicily), 40 (Tuscany & Sicily), 43 (Molise), 44 (Basilicata), 43 (Molise), 42 (Sicily), 44 (Molise - also the peak at 42C in Serbia), 43 (Sicily).

There have been occasional 45s showing up in some runs.

The heatwave now looking a little more intense again, but with an end point next weekend as high pressure builds over Western Europe. The most intense heat generally in the South but quite widespread across mainland and islands, and creeping into the Baltics.

Max temps in Italy per today's GFS 06z (similar to last few runs), from today:

41 (Sicily), 40 (Sicily), 40 (Tuscany & Sicily), 43 (Molise), 44 (Basilicata), 43 (Molise), 42 (Sicily), 44 (Molise - also the peak at 42C in Serbia), 43 (Sicily).

There have been occasional 45s showing up in some runs.

Thanks for keeping tabs on this, Tim(to echo Gavin). We're due to be in Grado(in the North East, near Trieste)for a week beginning tomorrow(Ryanair strike allowing) so I've been watching this carefully. Luckily, it looks like we'll avoid the worst of the heat. Plus, we'll be right by the sea. 

This is one of the reasons I would never book a holiday in the Med region during mid June to end of August.

You should, I would get away from the cloud infection country.  Really boring here today no sun and no action while there action heat over there.

According to one of the Italian papers today, five Italian cities managed record June temperatures. Florence was the highest at 40.2, followed by Viterbo at 39.8 and Rome at 39.