Extreme heatwave is challenging temperature records this week. Just a day after Italy tied with its all-time national record, the same weather station in the town of Siracusa, Sicily might shatter the European highest temperature record! This afternoon, Wednesday, Aug 11th, Siracusa has reported an astonishing peak temperature of +48.8 °C (119.8 °F). Heatwave now shifts to Spain and Portugal!
Data from the weather station are still being evaluated and the official confirmation will follow later. The extreme heatwave that continues across the Mediterranean region this week, has pushed the same weather station to 47.0 °C just yesterday.
Above: The temperature chart for Siracusa weather station. The peak temperature of +48.8 °C was set before the sea breeze brought higher moisture.
Nevertheless, the temperatures across a large part of the Mediterranean and northern Africa are very high. Tunisia, for instance, has set its new temperature record for August yesterday, the town of Jendouba reported +49.0 °C. The capital Tunis peaked at 48.9 °C, settings its all-time station records.
HEATWAVE CHALLENGES THE HIGHEST TEMPERATURES IN EUROPE
Such intense heatwaves that we are now seeing in the south are not uncommon in Europe, but they are becoming more frequent and even more extreme in recent years. One example is the historic heatwave across western Europe in summer 2019.
Not to mention the long-lasting heatwave in the southern Balkan peninsula, especially in Greece, through early August. Igniting deadly fires and destructions to many areas across the peninsula, including Turkey.
The highest temperature ever officially observed in Europe is +48.0 °C (118.4 °F), recorded in two cities, Athens and Elefsina, Greece on July 10th, 1977. While Greece was a record holder of the torch for the highest recorded temperature in Europe, Italy might just taken this unpopular title from them today.
Just recently, Greece was suffering its most intense heatwave for many years. The highest temperature was observed in the town of Langadas, northern Greece, peaking at +47.1 °C (116.8 °F).
The existing national heat record in Italy, however, is +47.0 °C, recorded in the city of Foggia, Apulia region in the south, on July 25th, 2007.
As we discussed earlier this week, the intense heatwave is nowhere to its end. While Italy will finally be released of these brutally high temperatures, the most extreme temperatures are now expected to develop over Spain and Portugal. Temperatures are very likely to surpass the 45 °C mark pretty easily from Friday through Sunday across Spain.
The existing Spanish official record is +47.3 °C (117.1 °F) from July 13th, 2017, recorded in the city of Montoro, Cordoba. While the highest temperature record in Portugal is +47.4 °C (117.3 °F), recorded in Amareleja, Beja on August 1st, 2003.
Attached above is the animation of the heatwave progress across the southern half of Europe through the rest of this week. It can be seen that the heat is finally moving away from Italy and Malta and shifts towards the west, engulfing the Iberian peninsula to bake Spain and Portugal over the coming weekend.
HEAT DOME NOW SHIFTS THE HEATWAVE TO SPAIN AND PORTUGAL
Heat dome is the term that was mentioned a lot this year. And we can’t blame the use of it. Sadly, the heat dome feature is responsible for all the record-breaking heatwaves that we saw around the world this year.
It forms under the upper-level ridge, known as the blocking High pattern. Such a pattern often brings very high, sometimes record-challenging temperatures for the region underneath.
A heat dome is a term that we use when a large area of high pressure develops over a large portion of the continent and stays there for several consecutive days and could even extend through two or three weeks period. The daily average temperatures under the heat dome are typically well above normal while the highest temperatures often challenge the existing records.
The heat dome works like a lid on a pot. The large lid is trapping a very warm air mass at all levels underneath, especially at the lowest elevations. It creates very stable weather and also very dry air mass with minimal chances for precipitation, or even clouds. This happens due to sinking air parcels in the center of the heat dome.
Typically, extreme heat follows as well as a significantly enhanced wildfire threat as drought develops or intensifies over the regions affected. Heat dome is often blamed for being responsible for deadly heatwaves around the world.
Through the early days this week, the heat dome parked over the Mediterranean and is still dominating the large region underneath. Extreme heat has spread across Algeria, Tunisia to Malta and Italy, also again into the southern Balkan peninsula and Greece. But thankfully, the heat dome and extreme heatwave underneath are now moving away.
But not for everyone. At the same time, a strong blocking High is spreading towards southwestern Europe where extreme heat is forecast to develop in the coming days. Extremely high temperatures are forecast as the heatwave is expected to expand over the Iberian peninsula and stay there for several days.
Temperatures will be much higher than they are in these days, as extremely warm air mass with around 30 °C at the 850 mbar level (approximately 1500 m above sea level) will overspread the Iberia. Air mass will be more than 10 degrees Celsius warmer than normal for mid-August.
So the temperatures at the lowlands will be much above average, becoming the most anomalous across southern Spain and Portugal this weekend.
BRUTAL HEAT EXPECTED ACROSS SOUTHERN SPAIN AND PORTUGAL
It will be extremely hot in some regions across southern Spain, potentially even above 45 °C locally, coming closer to the existing Spanish temperature records. Very hot will also be in southern Portugal. The air mass will be the same as was baking southern Italy recently, thanks to very warm temperatures and very dry air mass advection from northern Africa into the Mediterranean.
As we are heading into the second half of this week, the upper ridge and its heat dome parked over the Mediterranean is expected to turn towards the Iberian peninsula. Very high temperatures will already begin across Spain on Thursday, reaching up to around +42 °C in the southern parts and up to 39 °C in southern Portugal. Low 40s are also expected in the northeast regions of Spain on Thursday as well.
With Friday, the heatwave significantly intensifies across much of Spain and Portugal, thanks to a much warmer air mass advecting farther north and west across the Iberian peninsula. The peak afternoon temperatures are expected to reach up to +43 °C in the southern parts of Portugal, being up to around +40 °C in the central parts.
While much higher temperatures are expected across southern Spain. The far southern regions will likely see temperature climbing even above 45 °C, possibly ending up in the 46-47 °C range. Coming indeed very close to the existing Spanish record of +47.3 °C in Montoro. Even the central parts of the country will see temperatures in the low to mid-40s.
Then, the highest temperatures of this heatwave are likely to be expected over the weekend, as the upper-level ridge reaches its peak over southwestern Europe. It is very likely that temperatures will push to around 43-44 °C across southern Portugal on Saturday, even higher in southern Spain where up to around 47 °C is quite likely again.
Portugal will see a tad lower temperatures on Sunday, while Spain will be literally baking in extreme heat also on Sunday. With quite a high potential that the heatwave also extends into Monday and Tuesday next week there. At least across far southern Spain. While some refreshment might finally come through mid-week.
Spanish region Andalusia is usually the hottest area in the whole Iberian peninsula when an intense heatwave develops in this part of Europe. And this time the temperatures could be peaking at around +46-47 °C in the region. This will also be extremely dry air mass and create dangerous wildfire conditions.
The worst heat will spread across the provinces Cordoba, Seville, Badajoz, Ciudad Real, Jaen, and Huelva. While Cadiz, Malaga, Granada, Albacete, Toledo, and Murcia not being far behind either, just a degree or two lower temperatures.
The above chart is showing how extremely anomalous the air mass will be over the southern Iberian peninsula over the coming weekend. While the average temperature at the 850 mbar level through mid-August is normally around 19 °C, the southern Spanish regions will be battling the heatwave that brings close to 31 °C at this even.
No doubt the weather models are hinting at the near-record challenging temperatures for this part of Spain on Saturday and especially on Sunday.