Violent storms hard to predict in Gympie
WHILE Gympie is predicted to be in for a warm, dry summer, violent storms can not be ruled out, a Bureau of Meteorology expert said.
History shows the coming months are the wettest in the region, with rainfall totals a good indication of storm activity.
BoM forecaster Vinord Anand said rainfall in summer tended to come from afternoon storms and showers.
Gympie's November average rainfall is 88mm, with an average rainfall of 138mm in December and 165mm in January.
There's a 50% chance of exceeding the median Gympie rainfall this month, with an even lower chance in December and January.
In broader terms there's a 60-65% chance of getting less than the median amount of rainfall for November, December and January, but Mr Anand said the long term outlook was less convincing in accuracy than temperature.
"We are more certain that it will be hotter than average conditions.
"Around Gympie there is an 80% chance or higher of it exceeding the average temperature.”
With an average maximum temperature of 30C in November for Gympie and 31C for December, Mr Anand said there's a fairly good chance the maximum temperatures we will see over the coming weeks will be higher than 31C.
But the rising temperatures will not necessarily relate to more storm activity, the forecaster said.
"You need some sort of low level disturbance, maybe a trough or low pressure in the area and high humidity, maybe an upper trough,” Mr Anand said.
"You basically need moisture and generally unstable conditions.”
He said these things were harder to predict and vary from day to day and week to week.
He said while the outlook is tending towards a drier and warmer summer, it does not rule out storms that dump lots of rain over a day or two.
"It can easily flip around,” Mr Anand said.
"People need to be ready - we see the most violent storms in the spring and into the summer months.”
He said over broad areas storms become more predictable, but isolated storm activity can not be accurately predicted more than five to 10 days beforehand.
"Storms tend to be very discreet cells and can be very isolated, you can easily get one area that gets fairly localised,” he said.
"Some areas can get 40mm (of rain), while other nearby areas can get 10-15mm.”
Generally at this time of year, people realise they need to be more vigilant to prepare for these events, he said.