https://www.ansa.it/sito/notizie/topnews/2021/06/30/canada-caldo-fino-495-gradi-decine-di-morti-a-vancouver_c4822587-6894-4dd6-a95f-3c51182ec17a.html
Harbinger?
Canada: heat up to 49.5 degrees, dozens of deaths in Vancouver
New historical record of temperatures on the Pacific coast.
(ANSA News Agency) - VANCOUVER, June 29 - Canada set an extreme heat record yesterday, for the third consecutive day: 49.5 degrees were recorded in Lytton, a village northeast of Vancouver, in the middle of a heat wave that would be at the origin of dozens of sudden deaths reported in the region in recent days.
"At 4:20 pm Lytton Station broke daily and historic temperature records once again," tweeted Environment and Climate Change Canada (Eccc), the Canadian government department responsible for coordinating environmental policies and programs.
The Royal Canadian Mounted Police (RCMP) and Vancouver City Police have separately announced that at least 134 people have died since Friday in the metropolitan area located on the Canadian Pacific coast, in a grip of heat that is also affecting the country. west of the United States.
In Italy:
https://www.ilmeteo.it/notizie/meteo-weekend-e-avvio-di-luglio-prima-del-ritorno-del-caldo-faremo-i-conti-con-le-alluvionilampo-zone-a-rischio-174728
Flash floods: the Americans call them that, but they are nothing more than the flash floods that often hit Italy this season, causing considerable damage and unfortunately also victims, as the recent news of recent years teaches us (Palermo and Crotone in 2020, Matera in 2019, Cinque Terre in 2011, just to name a few examples not too distant in time).
The term flash-flood is different from that of classic flood and is used to indicate an extreme weather event that occurs as a result of intense thunderstorms associated with slow-moving or even stationary storms on small reservoirs, rivers, streams and even streams that before the rain they can also be completely dry.
This is a very dangerous phenomenon as the intensity of the rain is very high: in an hour, even the precipitations that would normally fall within 3 months can accumulate. The duration of the event is often short, in the order of a few hours at most and for this reason it is configured as one of the most extreme events, both due to the violence itself of the associated phenomena, and because it does not allow sufficient time to alert the affected population. .
Analyzing the climatological history of our country we know that the greatest risks are run after an intense heat wave, as large quantities of humidity and heat stagnate in the lower layers of the atmosphere. Subsequently, at the first fresh and unstable gust at high altitude (usually downhill from Northern Europe), the convective motions (hot air rising) favor the genesis of particularly violent thunderstorms, with a high risk of hailstorms and in some cases, more rare, even of tornadoes.
And this is exactly what we expect over the next weekend, in particular on Sunday 4 July, when a vast Atlantic depression will stretch towards Italy, recalling fresh and unstable air of polar maritime origin at high altitude, which will be able to scratch the dome. anticyclonic, starting from the Northwest regions.
Particular attention is focused on the alpine and pre-alpine sectors where rainfalls are expected, capable of discharging large quantities of water to the ground: up to over 100 mm in a very short time. Hence the danger of flash floods could materialize especially on the minor river and torrential courses first of our alpine valleys in extension then also to the nearby plains of Piedmont, Lombardy, Veneto and Friuli Venezia Giulia.
All this, before a new heat wave: from Monday 5 July, our models on the medium-long term, in fact, highlight a possible and progressive expansion of the subtropical high pressure and, therefore, a new conquest of most of it. of our country, therefore with generally drier and sunnier weather, but above all with temperatures that are rising sharply again, with a tendency to a new boom of heat for everyone.