Updated: Aug 21, 2019
Hi and welcome to our first of many wet season wrap ups for Northern Australia where we take a look at many Northern Australian towns/cities and go through their previous wet season and in October, we continue our features by speculating at what the early modelling might be showing for their upcoming wet season so become a subscriber, show your support and get access to this exclusive information. We thought we'd start with an area of Australia that doesn't get much recognition during the wet season.
Before we go through some of the stats for two of the Torres Strait Islands, it's important to understand where they lie in the Strait. Coconut Island lies in the North-East section of the Strait and is a little more sheltered from monsoonal North-Westerly winds and also tends to see less rainfall from the north-westerlies during the wet season. However Coconut Island does tend to see a little more dry season rainfall as it is more open to the south-easterly trade winds. In comparison Horn Island (next to the well known Thursday island) is located in the Southern Strait just off the coast of the North Peninsula and is far more open to monsoonal westerlies and strong convergence zones associated with the MT, but gets less dry season rainfall as it is sheltered from the south-easterly stream showers. That creates a difference of about 400mm overall through the year (1898mm at Horn island compared to 1493mm on Coconut Island)
WET SEASON 2018/19 RAINFALL Overall this area of Far Northern Australia suffered from the same issue the rest of the far north did - that is the monsoon was almost non-existent for large parts of the wet season. The season began slowly with very limited storm activity during October and November which is not entirely unusual in itself as most of the early season afternoon/evening storms tend to remain over the Peninsula and don't often move offshore and affect the islands. However, even noting those standards the lack of overnight/early morning shower and storm activity and very limited overnight rainfall in November was unusual. Normally the atmosphere is at least saturated and unstable enough early in the morning to result in some semi-regular showers, but that was not to be the case last season. December began slowly but the monsoon kicked in albeit in a very limited capacity along with Cyclone Penny around the last few days of the year and then continued into the first week of January, although it was not a traditional monsoon, it did result in useful rains and a period of strong winds (even gales) with falls of 200+mm across the Torres Strait in that last week of December and first week of January.
During the middle part of January we saw a relatively quiet period of weather again before an increase in activity later in January associated with what was another poor attempt by the monsoon to assert its dominance. This lack of activity associated with the monsoon trough also resulted in a record low rainfall total during February with the 20 year record being broken at both stations.
March too remained relatively uneventful, with just showers occurring across both stations with no real heavy rain days to write home about. Tropical Cyclone Trevor was the highlight for the region as it hit south of the islands near Lockhart River on March 17th. The cyclone and associated convergence banding resulted in about 200mm of rain across a 5 day period for Coconut Island , however the Southern Islands like Thursday and Horn saw much less than that. In April Coconut Island did quite well with some heavy showers and rain periods developing early in the month as the Winter south-easterly trade winds interacted with whatever was left of our pathetic excuse for a monsoon trough during the season resulting in about 200mm over the first 10 days of the month. All told the season remained below average for much of the Torres Strait Islands region.
TROPICAL CYCLONE IMPACTS
Nil significant impacts however Tropical Cyclone Penny incited monsoonal gales and heavy rains across Thursday Island and much of the Torres Strait southern half on the 1st and 2nd January after it crossed the Peninsula coast near Weipa (more on that one in our Weipa and Lockhart overview)
Tropical Cyclone Trevor was a stronger cyclone but very compact and was not associated with any strong pulse of monsoonal westerlies therefore the impacts across most of the Torres Strait were negligible.
Temperatures remained slightly above average for most of the season for the southern Torres Strait, but for the poor folks of Coconut Island in the eastern region, heat records tumbled. In a period of 10 days in October 2018, the previous daily maximum temperature record for October on Coconut Island was broken an astonishing 8 times. The monsoon's influence on January's temperatures was obvious with both stations recording slightly below average temps due to cloud cover particularly early in the month.
Where do we go next? Tune in tomorrow night to find out.
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