Why is the weather in Cairns so weird?
Once upon a time in TNQ, The Wet meant wet.
We expected a drenching, and we got it; cyclones were also an expected – if not necessarily beloved – part of life up here. Thankfully, we could always depend on temperatures to ease come mid-March.
But not this year.
The heat in March was off the charts, we’re copping a soaking in April and despite predictions of an above-average cyclone season, nary a breeze has lifted the hair from our brows.
So what’s going on?
TropicNow turned to BoM climatologist Tamika Tihema for answers.
After you get the low down from Tamika, check out our wry look at the 19 ways the wet season impacts life in Cairns. You'll love it!
WHAT’S UP WITH THE RAIN?
“It was a dry March, with 121.2 mm falling for the month, and just 29% of the long-term average (415.5 mm is the average March rainfall for Cairns).
“However, for April to date, the rainfall has amassed to 98.4mm (long-term April average 195.2mm).
“So Cairns has recorded about half the monthly average so far in April.
“A slow-moving high pressure system over the Tasman Sea is currently extending a firm ridge along the east coast of Queensland, directing a moist onshore southeasterly airflow onto the north tropical coast, with persistent shower activity over the last few days in Cairns and surrounds.”
The unseasonable – yet welcome – rain looks set to continue for the rest of the week, with a 70 per cent chance of showers predicted between Thursday and Saturday, and a 60 per cent chance of rain on Sunday.
HOW ABOUT THAT HEAT?
“In the last week or so, Cairns has experienced warm days, with every day from March 25 to April 3 recording daily maximum temperatures at or above 32.0C.
“April 4 was the first day to drop below this temperature, with a maximum temperature of 27.5C.”
Ms Tihema said there were a number of temperature records set in March at Cairns Airport.
“It was the warmest March on record at Cairns Airport in terms of mean temperature.
“Cairns Airport also had its warmest March nights on record, that is, warmest mean minimum temperature.
“The hottest day in March was 36.2C on the 28th, 5.6C above the long-term average.
“The hot day was accompanied by warm westerly winds, as severe tropical cyclone Debbie made landfall much further south.
“Overall for March, Cairns Airport had its equal warmest March days on record (that is, equal-warmest mean maximum temperature), matching March 1993.”
According to BoM forecasts, we can't yet expect maximum temperatures to be dropping below 30C, though nights should be more comfortable, with predicted lows of 23-24C.
WHERE ARE OUR CYCLONES?
In October last year, BoM meteorologists told TropicNow that there was a 58 per cent chance of an “above average” number of cyclones for the season, with the possibility of eight cyclones forming. What happened?
“When the tropical cyclone outlook was issued in October for the Australian region, we saw neutral to weak La Niña-like conditions in the tropical Pacific Ocean, and warmer than average ocean temperatures to the north and east of Australia, which influenced this year’s tropical cyclone outlook.
“Our models were pushing for above average numbers based on these indicators. During a La Niña, we expect more tropical cyclones in the Australian region.
“However, by mid-November, sea surface temperatures in the central tropical Pacific Ocean warmed, dampening chances of a La Niña forming.
“There were other factors too: we have seen very strong wind shear in the upper atmosphere, this inhibits the vertical development of tropical cyclones: it literally tears them apart, if they do try to form.”