Welcome to our seventh of many wet season wrap ups for Northern Australia where we take a look at Northern Australian towns/cities and go through their previous wet season. In October, we continue our features by speculating at what the early modelling might be showing for the upcoming wet season for these locations so become a subscriber, show your support and get access to this exclusive information. Today we head to central inland Queensland and specifically the town of Emerald in Queensland (pop approx 13500).
Coal mining is by far the area's top industry, but a few folks unfamiliar to the area might be surprised that cotton farming and giant solar plant is also what keeps people busy in the area. The town has a Subtropical, bordering on semi arid climate with little over 550mm falling in the area on average every year. and about 75-80% of that rainfall falling in the Wet Season. The average rainfall number can be quite misleading though, with variability of rainfall very high. The region is fed water by the large Fairbairn Dam and the size of that dam can withstand the normal variability of the area's rainfall on most years. It's when we combine 3 or more poor wet seasons in a row that the water situation becomes problematic. 2018/19's Wet was certainly below average and the dam currently lies at approximately 17% of full capacity, that will allow the dam to supply the region with water for about a further 12 months if the upcoming wet season fails.
WET SEASON 2018/19 RAINFALL Overall the season remained below normal and only two months (October and March) saw above normal rainfall. However the numbers can be a little misleading, much of the above average rainfall in October was due to individual convective cells, and while the meteorological station at the Emerald Airport was hit, it doesn't necessarily mean that the surrounding region did as well. So please bear that in mind when you look at the facts and figures. The rainfall in March was far more widespread and resulted in significant flows into the river system securing water for the region for the foreseeable future.
The season began with a line of storms on the 12th October and a more significant burst of storm activity on the 13th. The storms on the 13th dumped 48mm of rain, of which 40 fell in about 20 minutes around 7:00PM. Check out the radar imagery below for a look at how widespread that storm activity was. Further storm activity occurred on the 17th, 21st and 30th October to round out one hell of an active start to the wet season that saw almost three times the average rain amount fall on the town.
You would be forgiven for getting excited after such an active start to the season, but the weather Gods have a tendency to smack us back down to earth and smack they did. November, December, January, and February saw little in the way of any meaningful rainfall. What made this more painful to watch was that only a couple of hundred kilometres to the north, in early Feb, North Queensland was getting pummeled with rainfall, but that rainfall remained to the north or slipped to the west of the Emerald region.
It took until Mid March and Tropical Cyclone Trevor to hit the NT Gulf coast and move southwards before we finally saw enough moisture move back into the area to create widespread heavy rain storms over the town. 50mm fell on March 15 and this was followed up with a further 15mm the next day. Later in the month we saw another upper system dump a further 40mm on the 28th March. These two systems combined helped to finally bring some water into the local river systems and the Fairbairn Dam. April was relatively unremarkable but a further accumulated total of 40mm occurred from another upper system on the 25th and 26th to round out the season.
TROPICAL CYCLONE IMPACTS
Emerald was indirectly impacted by the remnants of Tropical Cyclone Trevor which hit the NT side of the QLD NT border and then traveled southwards into inland Eastern NT and inland Western QLD. Trevor was able to feed moisture into a trough system that impacted Emerald and helped to create an above average rainfall month for the town. No significant wind gusts were recorded.
While Emerald may have broken few temperature records in the 2018/19 season, make no mistake, it was a season characterized by well above average maximum temperatures under blue skies (lower than normal cloud cover), higher than normal evaporation rates and lower moisture levels than what we normally expect for the town and region.
There was one daily record broken on March 1st 2019 where the town recorded 41.7 degrees, this beat the previous record set in 2007 by almost a degree. Thankfully at the end of the day a weak but gusty storm cooled the place down. As I mentioned despite the lack of records broken across the season temperatures were well above average, even during cool changes we only saw temperatures revert close to average. There were just a few days all season where the temperature dipped well below average, and those days were tied in closely with upper level systems passing through the area.
Where do we go next? Tune in tomorrow night to find out.
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