More than 750 mm of rain has fallen in central Greece during the last 24 hours, triggering life threatening flooding and setting a new national daily rainfall record.

A low pressure system named Storm Daniel developed over the Ionian Sea, to the west of Greece, earlier this week.

The system has been drawing copious moisture from abnormally warm water in the Mediterranean Sea and converting it into thick clouds, heavy rain and thunderstorms over the Balkan Peninsula during the last two days.

Image: Sea surface temperature anomalies on September 3, showing warmer than average water in the Mediterranean Sea (circled). Source: NOAA

Rain and thunderstorms have been affecting several Balkan countries in the last 48 hours, although the focus of the heaviest rain has been in central Greece.

The satellite animation below shows Storm Daniel centred over the Ionian Sea on Tuesday afternoon, with a stream of thick clouds being driven over Greece.

Video: Visible satellite imagery captured by the Meteosat-10 satellite on Tuesday, September 6. Source: RAMMB/CIRA

At least two rain gauges in Central Greece received more than half a metre of rain in less than 24 hours on Tuesday.

According to Meteo.gr, the heaviest daily total in the country as of 8:45pm local time on Tuesday was 754 mm. This was the heaviest daily rainfall on record in Greece, beating the previous record of 644.7 mm from September 2020.

Image: Table showing the 8 highest rainfall totals in Greece on Tuesday, up to 8:45pm local time.

For perspective in Australia, the rain Central Greece received on Tuesday was similar to the deluge that led to the catastrophic Lismore floods in late February 2022. The heaviest 24-hour total in NSW during that event was 775 mm at Dunoon.

According to reports, at least seven deaths have occurred from the flooding in Greece, Turkey and Bulgaria.

Storm Daniel has been sweeping across western and central Greece, flooding homes and roads across the country https://t.co/F9xUYGnvvR pic.twitter.com/JwVPOlVqXK

— Reuters (@Reuters) September 5, 2023

This devastating flooding event comes after the country was hit by a spate of deadly fires in summer.

Rain and thunderstorms will continue over parts of Greece on Wednesday into Thursday morning, before easing on Thursday afternoon as the low moves away from the country.

The latest warnings from the Hellenic National Meteorological Service can be found here.