more showers and warmer averages

Malta is seeing an increase in ‘isolated showers’ compared to the less intense ‘rain’, observed the Meteorological Office – armed with a century of data.

The increase in the frequency and intensity of short showers, especially in the last quarter of the year, coincides with a decrease in rainfall, defined as more prolonged but less intense.

“The main difference we see is the lack of continuous light to moderate rain on a larger scale, compared to isolated showers,” said forecaster Martina Gatt, who has worked at the Met Office for eight years, and Jeffrey Custò, its administrator. weather systems.

“The latter can generate an equal amount of rainfall but in random areas and over a shorter period, while the former is more ideal for agriculture.”

Martina Gatt

Gatt and Custò are part of a team of five forecasters, five observers and two administrators who are celebrating the Met Office’s 100th anniversary this month and can rely on extensive archival material, including pages of observations weather documented at specific times each day in daily observation logs. .

1970s Wind Hand Plot1970s Wind Hand Plot

Hand-drawn synoptic maps, forming the basis of weather forecasting before the advent of forecasting technologies, also date back to July 10, 1922.

Distinguishing interesting climate observations a century later, the team also note that the climate of the Maltese islands has a cycle, particularly in terms of rainfall values, with a decade of dry years usually followed by another of wet. .

The 100-year average stands at 550 mm of precipitation, with the current climate standard (1991-2020) at 543 mm.

A clear example of this cycle was the average precipitation value for the 1940s and 1950s. Between 1940 and 1949 an average of 480 mm of precipitation was measured, followed by a total of 653 mm in the following decade.

“Gatt and Custò are part of a team of five forecasters, five observers and two administrators who are celebrating the Met Office’s 100th anniversary this month and can rely on extensive archival material, including pages from weather observations documented at specific times of each day in daily observation records”

Several factors may have had an impact on these climate changes, including the location of the Met Office.

His travels from Pietà in St John’s Cavalier to Valletta five years later, where he was underground during the war, and to Luqa, close to the flight information center and air traffic control services, at the end of 1946, influenced the type of data collected.

Over the past 100 years, the type of instruments used and their accuracy have also improved dramatically, while the level of human error has decreased as information is mostly collected digitally.

Archive foldersArchive folders

The introduction of automatic weather stations in the mid-2000s aided the bureau by allowing the recording of data from eight areas.

Measuring parameters such as wind direction and speed, temperature, dew point, relative humidity, precipitation, global solar irradiance, and atmospheric pressure, AWS also enabled forecasters to monitor the weather. across islands in real time, making it easier to issue warnings.

The heat is on

Over the past 100 years, the Met Office has also observed an approximate 1.1 degree Celsius increase in average temperature, as well as an increase in the duration of summer heat waves.

Digitization of the 1978 storm logDigitization of the 1978 storm log

The maximum temperature for this month of June was 38˚C, while in July, so far, it was 38.8˚C, with a heat wave, for the moment, of six days between 23 and June 28.

Over the past decade, heat waves have not been recorded every year, but each time they have occurred was in June.

Providing just a seven-day forecast, down from five in 2016, it was impossible to say what lay ahead in terms of summer heat waves, the national weather service provider said.

“Future predictions are not possible without proper studies, supported by several meteorologists.

“Even then, they would be completely moot because multiple volatile factors, past and future, have played or will play a role in such an extrapolation.”

The accuracy of forecasts from the Met Office stands at around 88 per cent, he said, whose main role is to provide weather services to the aviation, civil and maritime industry.

But forecast accuracy is expected to be improved for both the public and aviation through the introduction of higher resolution numerical weather prediction models and tephigrams.

The pipeline improvements will be effective especially in fog and low cloud cover, Gatt and Custò announced.

“Some situations, although quite rare, cause adverse weather conditions to develop very quickly on our islands and we need to disseminate this new information at very short notice.

“In these cases, the first priority is to inform air traffic services, which in turn can relay the information to all incoming flights,” they explained.

Data demands are now more intense, especially following extreme weather events, forecasters also observed.

“Interest in the weather has always been strong in the Maltese Islands. However, lately we have noticed an increased interest in climate change and the factors that contribute to it.

“Conversation about ‘climate change’ tends to increase during the summer months, brought on by frequent heat waves, as well as in the spring when less rainfall is recorded than expected,” they noted.

The Met Office team take the health, welfare and safety aspect of their work “very seriously and always aim to provide factual rather than sensational information to the public”.

The Met Office, which celebrates its 100th anniversary this month, may see a pattern of more isolated showers and longer heat waves over its century of record keeping. Photos: Chris Sant Fournier


January 16, 1978

Storm and gale force winds are battering the islands, with wind gusts reaching 61 knots and 36.4 mm of precipitation measured in less than 24 hours, leaving a trail of damage.

December 2, 1989

A storm hits the Maltese Islands on December 2, 1989, during the Malta Summit between George HW Bush and Mikhail Gorbachev. A total of 68.1 mm of rainfall was recorded, while the average wind speed was that of 21.4 knots and a maximum gust reaching 49 knots.

First meteorological observation on July 10, 1922First meteorological observation on July 10, 1922

October 24, 2010

102.2mm of rainfall is measured in Luqa over a 24 hour period, with some areas of Malta experiencing flooding and significant damage. Flooding in Qormi leads to a particularly memorable incident where coffins from an undertaker’s warehouse are carried through the streets on floodwaters.

February 9, 2018

Prolonged rainfall produces 117 mm of precipitation, making the ninth day of the month the second wettest day since 1923. The climate norm for precipitation for the whole of February is 56.9 mm (1981-2010).

October 2018

Stormiest month since 1922, with 16 stormy days. The month also produces 189 mm of precipitation, which is well above the monthly climate norm of 75.6 mm (1981-2010).

February 23 -24, 2019

A severe Gregale storm hits the Maltese Islands, with wind gusts reaching 54 knots. A total of 43.8 mm fell on February 23, almost half the amount of rain received in February. With a total of 93mm of precipitation spread over 11 days, February is wetter than the climate norm, but produces only half the amount of rain recorded in February 2018.

January 9, 2021

The maximum temperature peaks at 25.8˚C, setting a new monthly record, as a southwesterly wind blows in from the Sahara Desert, fanning the air temperature. Warm air is trapped overnight due to the presence of dense, multi-layered cloud cover.

June 2021

A long heat wave began on June 20 and persisted until July 1. On the last day of June, the temperature soars to 41.5°C, setting a new temperature record for the month.

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