Cyclone Kirrily hovered over the Coral Sea collecting water for days, so where is the rain?

Strong wind gusts battered the coast as Cyclone Kirrily passed through but the system brought little rain. (ABC News: Victoria Pengilley)

It’s the case of the missing rain.

The now ex-Tropical Cyclone Kirrily came with similarities in formation and strength to Tropical Cyclone Debbie, which battered the coast in 2017, but the system largely held off on the predicted rainfall.

It was described by the Bureau of Meteorology (BOM) on Friday as “a wind event rather than a rain event”, despite it initially forecasting localised daily rain totals between 200-300 millimetres within a 24 hour period, after its coastal crossing.

Floodwaters fill the gutters of streets in Cairns. (ABC News: Dean Caton)

Cyclone Kirrily has been described as a wind event, with little rain falling during the system. (Supplied: Kayla Burrows)

Despite several flood watches in place and severe weather warnings, gauges around the impact zones remained relatively low.

Townsville recorded just 31mm within a 24 hour period on Friday, which coincided with when the eye of the storm passed through the city.

There were some areas that received more than 100mm, including 163mm in the 12 hours to 6:12am at Mt Garnett, and 129mm to 7:08am at Upper Poison.

While it’s good news the system didn’t produce the big wet BOM expected, authorities have warned communities they’re “not out of the woods yet”.

So where did all that water go?

Well it’s still in the system.

BOM confirmed moisture remained with ex-Tropical Cyclone Kirrily and it’s expected to fall over the next few days.

Senior forecaster Angus Hines said, as Kirrily continued its path through the northern interior of Queensland, it was likely to bring extensive wet weather.

“The system is expected to stay on the map producing rainfall for the next several days — even producing rain in the Northern Territory and northern parts of WA,” said Mr Hines.

But there’s been one key difference between ex-Tropical Cyclone Kirrily and ex-Tropical Cyclone Jasper, which may be reducing rainfall totals.

“Jasper was just stuck in the mud,” the forecaster said.

“The system was stationary and stagnant across north Queensland and that’s where we saw day after day of rainfall, with some places receiving over a metre of rain.”

In comparison, ex-Tropical Cyclone Kirrily has been swift moving — maintaining a pace of 15-20kph — which has been evenly distributing totals.

“Because Kirrily has movement, it’s not raining in one place for too long,” Mr Hines said.

Why are there still flood watches? 

Flood watches are based on how much rain is predicted to fall on an entire catchment, which feeds into a river.

“It’s only if it looks like there’s enough rain on the forecast to cause a river to respond or rise, that’s when the bureau issues a flood watch,” Mr Hines said.

“Then when it’s actually raining, we use the gauges to see if rivers are rising above their usual flows and that’s how we begin issuing minor, moderate and major flood warnings.”

When a flood warning is issued, that means a river has already begun responding to rainfall, and it’s intended to warn residents downstream of potential impacts.

While all eyes remain on ex-Tropical Cyclone Kirrily, the BOM said there could still be more cyclones to come this wet season.

“There’s nothing in the short-term over the next seven days, but given we’re only in January, it’s likely we’ll see further tropical development around the northern states of Australia,” Mr Hines said.

“History does suggest there will probably be more cyclones in the next few months as we’re still early in the season”.