Today marks the beginning of the tropical cyclone season for Queensland, Northern Territory and Western Australia, a season that will span until the end of April. Also today, heralds the beginning of the southern Bushfire season for southern WA, South Australia and Victoria.
In the absence of strong climate drivers (the Indian Ocean Dipole (IOD) and the El Nino-Southern Oscillation (ENSO) are currently neutral and are looking to be so throughout summer. We are expecting a near-average cyclone season across northern Australia. On the other hand, the sea surface temperatures surrounding Australia have been warm, in fact close to be the warmest on record and these provide the heat that fuel tropical cyclones.
On average, that means we can expect 11 tropical cyclones within the Australian area of responsibility with only a fraction (four) actually making landfall on the Australian coast.
To the south, the threat of bush fires will now increase as hotter days become more seasonal along Victoria, southern SA and southern WA. Although grass and forest fuels will have some moisture due to the good winter and early spring rains in Victoria, bush fires can still occur during late spring as days get hotter. Especially on those days where a cold front will drag warm and gusty northerly winds ahead of it from the central interior. The season will peak about early-to-mid summer when the fuel would have dried out and temperatures would have reached its peak, although by this time winds tend to be not as strong.
Although tropical cyclones can hit anytime anywhere, higher than usual bush fire potential has been highlighted for East Gippsland, Northern Country, North Central, Central and the Northern South West in Victoria; the North West Pastoral in SA and the southern and western coasts of WA. Suffice to say, that doesn't exempt other regions in the south to be a bush fire risk.
© Weatherzone 2013
11:34 EST Canberra is set to see a few mornings drop below freezing as a high sets up over the southeast.