Wild storms threaten QLD and NE NSW this week!

8 Day Rainfall 11/10/2001- 18/10/2011. Source: Bureau of Meteorology

In my most recent weather updates on Ten's Weekend News, I gave a heads up on some major rain and thunderstorm activity that's on the way to parts of QLD and northeast NSW this week. I thought I'd give you some more detail.

Last weekend, southeast QLD experienced fierce thunderstorms with wind gusts reaching as high as 139kmh in Oakey (that's as strong as a cat 2 tropical cyclone), widespread falls of 20-70mm (most that occurring over 1-2 hours) and almost 30,000 lightning strikes!

This week, we have the ideal atmospheric set-up for the most intense and widespread thunderstorm activity so far this season. Onshore winds are carrying humid, moist maritime air from the Coral Sea right over inland parts of QLD and northeast NSW. But it's not enough just to have a saturated atmosphere- you need a trigger. This "trigger" will arrive in the form of a low pressure trough. This trough will rapidly lift this warm, moist air high up into atmosphere where it will condense and form into cumulonimbus thunderstorm clouds.

On Tuesday and Wednesday, isolated showers and storms are likely on the QLD coast mainly in southern parts of the Central Coast and Capricornia districts, roughly from about Townsville/Bowen to Gladstone. Some falls may spread inland to affect the Central Highlands and Coalfields. But the main rain and thunderstorm activity will be from Thursday onwards with most of eastern, southern and central QLD and northeast NSW affected. These thunderstorms have the potential to be severe with flash flooding from heavy rain (there is so much available moisture!), damaging winds and large hailstones. By the end of the week, widespread falls of 50-100mm are likely, but some places may see this amount in the space of a few hours underneath isolated intense thunderstorms. Some river flooding may also develop.