in June we call them East Coast Lows....TC's technically need a water temp in excess of 26.5 degrees to form - although they can still power though water temps below this once they have formed. On the east coast they normally become heavy rain depressions as they travel southwards into colder water. Thats why TC's do not come too far down the coast of NSW..... ECL's are intense low pressure systems. Usually occur when the land / sea surface temp is great than 6 degrees and when there is favourable conditions in the upper atmosphere. Once conditions are ripe for an ECL its not uncommon to get several in a row. The Pasha Bulka ECL in 07 was the last in a series of them as an example.

Just found this on the BOM website for you

What is the difference between an East Coast Low and a Tropical Cyclone.

Tropical Cyclones develop over very warm tropical waters where the sea surface temperature is greater than 26°C. They have relatively long life cycles, typically about a week, and severe tropical cyclones (category 3 or greater) can produce significant property damage with wind speeds over 180km/h near the centre, heavy rainfall and coastal inundation through storm surge. Tropical Cyclone "Justin", which affected the Queensland Region in March 1997, lasted for 18 days!

East Coast Lows generally have much shorter lifetimes than Tropical Cyclones and last only a few days. They develop over the Tasman Sea close to the NSW coast and can intensify rapidly in the overnight period. Unlike Tropical Cyclones, where the warm seas provide the energy source, East Coast Lows are driven by the temperature gradient between the Tasman Sea air and cold air in the high levels of the atmosphere over the continent. They can produce gale to storm-force winds, very heavy rainfall and in some cases coastal inundation. While maximum wind speeds recorded are lower than in severe tropical cyclones, a gust of 165 km/h was recorded at Newcastle associated with the east coast low that sunk the bulk carrier Sygna in 1974. During the first of the ECLs in June 2007, when the bulk carrier Pasha Bulker ran aground, gusts of 105 km/h at 6:21am on 8 June and 124 km/hr at 1:32am on 9 June were recorded at Newcastle.

Yeh I was kind'a going for dramatic effect when I said cyclone...But....It is predicted to form up off the sunny coast and the forcast I was looking at is so far calling it to drop to the mid 800hkp which is pretty low presure.Anyway Im an optimist and I would love a big winter NE swell to play with.

gumballs said...

Yeh I was kind'a going for dramatic effect when I said cyclone...But....It is predicted to form up off the sunny coast and the forcast I was looking at is so far calling it to drop to the mid 800hkp which is pretty low presure.Anyway Im an optimist and I would love a big winter NE swell to play with.

I think they would only get mid 800's on Jupiter, Mid 900'S I think only occur in the
roaring forties down south, but anything below 980 is wild I think ?