FORMER CYCLONE YASI FEEDING DESERT DOWNPOURS
Tropical Cyclone Yasi raised havoc with its raucous landfall on the Queensland coast at the middle of last week. Preliminary reports reckon $500 million in losses including about 150 homes.
Since that time, the storm has dissipated as a named tropical cyclone, yet a leftover circulation core has hung together triggering flooding cloudbursts far south and west of the site of landfall.
Yasi tracked across the northern Great Dividing Range to the much drier west of Queensland, where it menaced the big metal mining camp of Mount Isa with heavy rain and high winds.
Since then, the old heart of Yasi has rolled westward and southward into Northern Territory and South Australia. It may yet reach the vast state of Western Australia before becoming altogether unidentifiable.
Image credit: Australia BOM
Aside from the icy-cold desert of Antarctica, Australia is the driest continent, much of it being classed as desert or semi-desert.
Yasi's leftovers have trekked exactly such a landscape triggering showers and thunderstorms along the way.
Localized flooding cloudbursts have pelted the red desert heart of Northern Territory and South Australia since last Friday.
All-time record high 24-hour rainfalls were registered at two sites in South Australia, according to the Australian news media. One was that of Yongala, where a fall of 128 mm topped a record set 121 years ago.
Another was that of Hallet, which got 98 mm late last week. The old mark here was set in 1890.
As of Feb. 7, an even higher amount, 174 mm, was measured at Ernabella, S.A., according to the Australian Bureau of Meteorology.
Apparently, runoff from the desert cloudbursts is filling dry washes to overflowing. Normally dry lake beds are becoming temporary lakes.
VICTORIA, NEW SOUTH WALES ALSO HIT
Late last week, a cold front swinging northeastward in Victoria and New South Wales sparked heavy rains and more flooding. This front got a boost in moisture from Yasi, enough so that it poured 50 to 150 mm of rain over much of greater Melbourne.
SYDNEY HEAT WAVE BROKEN
T.C. Yasi was steered by high pressure centered aloft over eastern Australia, so while this storm was working its deeds across the north, it was instigating a heat wave over much of New South Wales.
Sydney, especially, was gut-checked by the blast of heat, which began on the last day of January.
February kicked off with a high of 40.8 C, then the heat topped out at 42.2 C on Feb. 5.
Taken as a whole, the week ending Feb. 6 was hotter than normal by 7.5 degrees C.
The same cold front that doused Melbourne smashed the Sydney heat wave with a "textbook" southerly change on Feb. 6.
After a fast run-up to 34 C, a "southerly buster" kicked in, the gusty southerly wind driving the temperature down to 20 C in the afternoon. Today, Feb. 7, has only reached about 22 C, normal being nearly 26 C.
A spot to watch will be northern Queensland, where some kind of tropical weather system is indicated by some numerical forecast models. Impact would be that of torrential rain along and near the northern Queensland coast at midweek.
The plum rains are known as "meiyu" in China, the "baiyu" or "tsuyu" in Japan, and the "jangma" in the Koreas. The heart of the plum rain season stretches from early June to mid-July, with a tendency to shift south to north across the affected area.
In the wake of the mid-June cloudbursts, most of Pakistan to northwestern India last week saw a return to dry, hot weather typical of the weeks leading up to the Monsoon onset. It was as if the Monsoon withdrew to its "normal" position for the latter half of June.
The 38.5 degree C (101 degrees F) reading Tuesday in Ajaccio, Corsica, may have been tops in Europe.
Monsoon Onset was June 13th, 2013, in Delhi, almost two weeks earlier than average. The June 15th onset at Karachi and Islamabad was more like three week ahead of schedule.
In Pakistan, hit-or-miss downpours missed the Sindh capital, Karachi. One did hit Pad Idan, where it left 60 mm of rain Wednesday. This was more than 20 times greater than the normal June rainfall.
It is still possible that this scenario is over wrought as to the intensity and spread of rain in Pakistan and northwestern India. However, it is the hunch of the present forecaster that some very unusual weather is going to unfold in the Subcontinent during the next week!