The meteorological summer is set to end on a particularly hot note, as the Maltese Islands enter the second heatwave of the season from today, the Met Office said Friday. Between today and Sunday, maximum temperatures are expected to rise to, and even exceed, 38°C, almost 6°C above the climatic norm for August.
As a result, the Meteorological Office currently has an Orange Weather Warning in force due to the intense heat. The public is encouraged to follow the advice issued by the health authorities, take all necessary precautions and pay particular attention to children and vulnerable individuals.
The high temperatures experienced over recent days are the result of an African anticyclone that moved across the Western and Central Mediterranean at the beginning of the week. This system is being sustained by an upper-atmospheric weather pattern known as an "Omega Block", named after its resemblance to the Greek letter Ω on weather maps. As this pattern begins to shift over the coming days, the African anticyclone and its associated heat dome are expected to retreat southwards, bringing some respite from the intense heat from the beginning of next week.
AIRBORNE DUST TEMPORARILY LIMITS TEMPERATURE RISE
A layer of airborne dust currently suspended high in the atmosphere over the Central Mediterranean originated over western Algeria on 25 August. Dust concentrations over the region peaked yesterday, with the layer partially shielding the Maltese Islands from direct solar radiation and limiting the maximum temperature to 34.2°C. Without this layer of dust, temperatures would likely have risen considerably higher.
The airborne dust is expected to remain over the Central Mediterranean over the coming days before gradually shifting eastwards from Wednesday next week.
'FEELS LIKE TEMPERATURE UP TO 46°C
Temperatures over the coming days may feel substantially higher than the values actually recorded by thermometers due to the high levels of humidity. The 'feels like' temperature is calculated using the actual air temperature together with the dew point, which provides an indication of the amount of moisture in the air.
The current sea surface temperature stands at 30°C, around 3°C above the climatic norm for this time of year, and is contributing significantly to the high humidity levels currently being experienced.
With the warmer-than-average sea combined with southerly winds bringing warm and humid air over the Maltese Islands, the 'feels like' temperature is expected to approach 46°C.
It is also worth noting that a new record was set in the Meteorological Office's archives this month, when the sea surface temperature reached 31.1°C for the first time on 11 August.
The highest temperature recorded so far this week was 41.2°C, measured on Wednesday, 26 August. The highest temperature ever recorded during the month of August was 43.8°C, measured on 9 August 1999.
LOOKING AHEAD TO NEXT WEEK
Although temperatures will remain high, maximum temperatures are expected to drop by around 4°C between Sunday and Monday, bringing this heatwave to an end after three days. The first heatwave of this summer lasted seven days, from 16 to 22 July.
Temperatures are expected to continue decreasing over the following days as cloud cover increases slightly, providing some relief from the intensity of the sun. Nevertheless, temperatures are forecast to remain above 30°C, with 'feels like' temperatures reaching around 36°C.
While the last month of the meteorological summer is associated it with hot, sunny weather, but also typically receives some rainfall, August has remained completely dry this year. In fact, the last rainfall recorded at the Meteorological Office's weather station in Luqa dates back to 16 May.