[WATCH] Polar air mass brought cold to Malta and it’s still in the Mediterranean

A polar air mass known as Polar Continental, drifting down from Siberia, was responsible for the sudden dip in temperature in Malta and while the air mass has moved away, it's still to the east of the island, chilling the Mediterranean. 

Before the arrival of the air mass, the temperature on 27 December was above average and mild at a daytime maximum of 18.4°C. The meteorological office told MaltaToday that as soon as the air mass penetrated the Mediterranean, Malta's daytime maximum temperature dipped to 12.4°C, below the December average. 

"Strong wind gusts, which reached 29 knots in Luqa on 29 December, even contributed to a chill effect, but the truth is that since the wind comes off from the sea, which is warmer than land mass air, it modifies the temperature so that the polar air mass doesn't affect Malta as much," forecaster Saviour Zerafa told MaltaToday. 

The wind drags relatively warm temperatures from over the sea and into land, the forecaster explained, adding that this was why Malta's temperature never dips below 0°C, something which is a common occurrence in Tripoli, 1,000 kilometres south of Malta. 

When the wind gusts died down, the coldest temperature was then registered on 3 January at 6.7°C in the early morning. 

The same thing happened back in December 2014 when the polar continental air mass, known in the Mediterranean as the 'Bora wind', caused temperatures to plunge as low as 2.8°C on New Year's Eve of the same year.

Malta's record minimum was 1.4°C, registered in January, 1981.

December has been drier than usual for years

The month of December, the forecasters said, is normally the wettest month of the year. Since the 1920s, December has been providing a high amount of rainfall.

"This started to change around 2014, when December was no longer the wet month we've known it to be," Zerafa told MaltaToday. "There are many theories, it could be a climactic movement, it could be related to the climate change phenomenon."

The average rainfall for the month of December is 104.7mm, but December 2019 saw less than half of that average at 51.2mm. 

The month of October seems to have taken December's place in terms of rain as October 2019 saw more rain (94mm) than average amounts (75.6mm). 

Air mass satellite image from 6 January 2020: cold, dry air from Siberia has migrated south (violet pigment: cold dry polar air)

Zerafa explained that there has been a slight shift in the Maltese climate in recent years, with winters starting late and summers starting even later. As forecasters, he said, they were only charged with observation and could not give credence to any theories they had.

"There were some bouts of rain in December but a low pressure mass has pulled the clouds to the east of Malta. In fact, there are storms currently taking place over the sea," Zerafa said, explaining that Greece, Cyprus and the Balkans were suffering the brunt of the cold and stormy weather. 

While Malta is presently enjoying some sunshine, the temperature is likely to get cold again due to the polar air mass still doing the rounds in the Mediterranean.  

In official records released by the MET office, Malta was said to have experienced extreme weather and unusual phenomena in 2019. February, the records read, was the second-coldest month since 1923, with temperature going down to 3.7°C.

However, the year proved warmer than usual on average. It was 0.4°C higher than the norm and the total rainfall recorded in 2019 (536.2mm) was also lower than the norm (567mm).

The strong northeast February winds reached 100 kilometres an hour. The gale force winds saw farmer's livelihoods put at risk, flooding and damage to trees and infrastructure, and were the strongest winds since February 4, 1955, which holds the all-time record for strongest winds at 130 kilometres per hour.