IGEM Report 1: 2017-18 - THE CYCLONE DEBBIE REVIEW

The Cyclone Debbie Review

Some groups based plans on recollections of the weather updates at a point in time, while others recalled hearing changes through different channels, ranging from personal phone calls through to news items.

Much credence was given to the importance of local knowledge – not always reliable, as in one case water levels exceeded the memories over a lifetime.

The three concurrent events

Changes in rainfall forecasts

North Queensland

Rainfall warnings started at “150 - 200mm with isolated falls of 400mm” as part of their cyclone warnings and flood watches. The language used in warnings changed as the system tracked to the southeast with warnings of 150-250mm with “significantly higher isolated falls.” In the verbal briefs and flood warnings the higher falls were quoted as 300mm and later upgraded to 400mm.

State-level operations

Central Queensland

South East Queensland

Examples from SDCC Update reports: • Tue 28 April 0834 & 1217, page 3

‘Widespread daily rainfall totals of 150 to 250 mm, with isolated event totals over 500 mm”

• Tue 28 April 1600, page 3

“Widespread daily rainfall totals of 150 to 250 mm are expected, with significantly higher totals possible locally.”

1 April

2 April

3 April

4 April

5 April

6 April

7 April

Thursday 30 March

Friday 31 March

5pm 6pm 7pm 8pm 9pm 10pm 11pm 12 mn 2am 5am Noon 5pm

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4 THE THREE CONCURRENT EVENTS

South East Queensland: Detailed local and district activations