Unseasonal severe thunderstorms expected in New South Wales and Queensland, Australia

Severe thunderstorms with damaging winds, large hail, and heavy rain that may lead to flash flooding are likely across northeast New South Wales and southeast Queensland, Australia on Tuesday, May 11, 2021.

"Mid-May is an unusual time for severe thunderstorms to develop, however high humidity combined with a powerful, upper-level low are forecast to bring increased thunderstorm activity during the early hours of Tuesday morning, with peak activity expected during the afternoon," BOM Meteorologist Sarah Scully said.

The hit and miss nature of thunderstorms make it difficult to forecast exactly where the heaviest rainfall totals will be, however soils are saturated due to recent rainfalls leading to an increase in surface run-off and an increase in the likelihood of flash flooding.

"Please take care on the roads during this particularly hazardous weather event," Scully said.

Storms and convection are forecast to continue into Wednesday and Thursday, May 12 and 13, however, they are less likely to be severe.

Southeast Australia is also expecting damaging winds and heavy rainfall, forcing BOM to issue Severe Weather Warnings for parts of the region.

Winds averaging 60 to 70 km/h (37 – 44 mph) are expected today, with peak gusts of around 90 to 100 km/h (55 – 62 mph), particularly about coastal and elevated areas, easing later this evening.

These winds will be strong enough to bring branches of trees down, creating hazardous driving conditions.

It may also be the coldest day of the year for many people and there's snow forecast about elevated areas, according to Scully.

A Sheep Grazier Warning has been issued for the cold, wet and windy conditions across the region.

The storms will contract eastwards as the low-pressure system moves and deepens over the land, Scully said.

Featured image credit: JMA/Himawari-8, RAMMB/CIRA, TW. Acquired 05:40 UTC on May 10, 2021