Greece was hit by Storm Bora last weekend, with torrential rain, strong winds and strong thunderstorms affecting the islands especially Rhodes and Lemnos.
A storm formed on Friday, November 29 and is expected to intensify by Saturday, with wind speeds of up to 80 mph. Rhodes had 300,000 feet of rain, causing flash flooding and widespread disruption. Power outages, school closures, overturned vehicles, and collapsed bridges were reported along with three deaths.
Authorities have declared a state of emergency in places, with heavier rains expected to affect Rhodes and other eastern Greek islands in the coming days.
Storm Bora was a low pressure system over the Ionian Sea that was moving east across Greece. December is the wettest Greek month, and the Bora storm follows the Alexander storm, which also formed in Ionia and reached the region only a month earlier.
Meanwhile, Australia has experienced an unusually wet start to its summer. Severe storms have moved across eastern regions, bringing heavy rain of more than 100mm in some areas – and hailstones. Sydney, Brisbane and Victoria were the most affected.
Flash flooding submerged parts of Brisbane after 40mm of rain fell in one hour on Sunday. Queensland had more than 200mm less in 24 hours, while Sydney received 25mm an hour.
The storms were stirring up the unstable air, increased by the upper channel. This channel caused the phenomenon of cooler air, which increased the upward movement of warm, moist air at the surface, increasing atmospheric instability and promoting the formation of thunderstorms.
According to the Australian Bureau of Meteorology, the country is expected to experience a warmer-than-average summer, with above-average rainfall across the eastern and north-western regions in December. This is due to warmer sea surface temperatures, which increase atmospheric humidity. With the resulting atmospheric instability, this provides ideal conditions for frequent thunderstorms in the weeks ahead.
In the past few days in South America, Brazil, Uruguay and Argentina have been affected by severe thunderstorms. Storms in the Uruguayan cycle swept along the coast of Uruguay bringing rain and winds above 50mph.
The southern Brazilian state of Rio Grande do Sul was hit hard, with strong winds causing widespread power outages, affecting about 3 million people. As of Wednesday, December 4, at least 50 people have been injured, and significant damage to homes and infrastructure has been reported.