Saturday, 2 September 2017

Winter weather Down-Under

Wild weather for southern Australa



Via Facebook

***** BLIZZARDS, RAIN, SEVERE DAMAGING WINDS, LOW LEVEL SNOW, SMALL HAIL & THUNDER ABOUT TO IMPACT TASMANIA, VICTORIA, SA, NSW *****

**** PLEASE SHARE/TAG THIS IMPORTANT INFORMATION & MAPS WITH FRIENDS AND FAMILY ****

Good evening everyone... HUGE week coming up in weather for south eastern Australia starting this weekend until next weekend!

Yes it may be September but south eastern Australia will be seeing weather more more reflective of mid July the coming 7-10 days!

Numerous cold fronts and cold air troughs will barrel there way into south eastern Australia starting today and tonight with some light rain over parts of SA as well as the odd rumble.

It will progressively get colder and colder with snow becoming a feature in Tasmania and Victoria early next week.

WINDS Will be a problem especially in Victoria tomorrow and possibly southern NSW and Tasmania. The BOM have already issued a severe weather warning for large parts of Victoria for Saturday with wind gusts possible 70-100km/h and as high as 120km/h about the alps.

Strong to gale force westerly winds will continue into early next week especially high altitude and about the coasts in Tasmania, Victoria, south east coast of SA and possibly into southern NSW.

SNOW: Heavy snow is predicted for the VIC, NSW and TAS ski resorts/high altitude 50-100cms of fresh snow is predicted the coming week! Snow will fall to 300 metres in Tasmania and 400 metres in Victoria including the Otway ranges, Grampians, Ballarat region may all see some snow. Snow will also fall close to the ACT and light snowfalls is also a chance about the central tablelands west of Sydney early next week.

RAINFALL: Most of Tasmania, Victoria, southern SA and southern NSW especially about the ranges will see the best of the rain the coming week with substantial falls (50mm+) likely about the south west coast of Victoria, south east coast of SA and ranges, western Tasmania, Vic ranges especially north eastern ranges and NSW southern ranges. Cold air thunder and small hail is also likely south eastern SA, Victoria, Tasmania and southern NSW with the colder air.

As the trough moves through during the weekend isolated thunderstorms are likely especially SA (Saturday), NSW and QLD (Sunday). However little if any rain will fall from these storms especially in northern NSW and southern QLD.

More to come over the coming days.

Comments from Kevin Hester

"My layman's take on this polar weather coming north at this time of the year is based largely on what Paul Beckwith has painstakingly taught me over the years.

"I would suggest that with the melt gaining pace in the Antarctic we are starting to see the jetstreams meandering as we have in the North.

Jet stream winds today


More evidence of a destabilised energy balance on the planet from what we would have previously called 'normal'."




Meanwhile in Wellington, NZ we have amost no sun all winter and there have been landslips all over the the capital



A massive landslide in Wellington has swept away backyards and left houses teetering on a cliff edge.

At least 90 people in the suburbs of Kingston and Berhampore were evacuated early this morning when a slip about 40 metres wide by 100 metres long came away from under houses in Priscilla Crescent.


A resident, who did not want to be identified, said her backyard had disappeared.


Meanwhile Australia's winter temperatures reached a record

Australia's hottest winter on record, maximum temperatures up nearly 2C on the long-term average
Winter in Australia this year was hot and dry with the average maximum temperature up nearly 2 degrees Celsius above the long-term trend.


ABC,
1 September, 2017


The 2017 winter was the hottest since 1910 when national records began, according to Bureau of Meteorology figures released today.

The average maximum daily temperature recorded across all Australian recording locations for June, July and August 2017 was 23.7C.

That is a whopping 1.9C degrees above the baseline 1961 to 1990 average of 21.8C and smashes the previous record of 23.4C set in 2009.

Nights were still cold



The warm weather was most pronounced in the north of Australia.

It was the hottest winter on record for Western Australia, Queensland and the Northern Territory, while New South Wales and South Australia made the top three.

Daily minimums were also warmer than average in most of northern Australia but not as far above average as the maximums.

In contrast, inland NSW and northern Victoria had notably cold nights with many areas 1C to 2C below average.

NSW had its coldest average winter nights since 1997.


Meanwhile nationally it was the ninth driest winter on record. The only large area to record rainfalls significantly above average was a pocket of central NT as a result of one rain event in mid-July.

Skies stay clear

Andrew Watkins, manager of extended and long-range forecasts at the Bureau of Meteorology, said the real reason for the warmth was the persistent high pressure seen particularly during early winter.

"But you also have to add to that the long-term warming trend," he said.
"The higher than average pressure has kept the skies clear and rain away — meaning more heating of the inland from the sun and less evaporative cooling from ample water on the ground."

Australian weather extremes

Winter 2017
Hottest day
39.6C
Mandora WA, August 24
Coldest day
-5.4C
Mount Hotham Vic, August 27
Coldest night
-12.1C
Perisher Valley NSW, July 16
Warmest night
26.6C
Coconut Island Qld, June 2
Wettest day
125.6mm
Perisher Valley NSW, August 16
Source: Bureau of Meteorology

Evaporative cooling is the same process that cools you down when you sweat, taking energy from the surrounding air to convert liquid water into gaseous water vapour, leaving the surroundings cooler.

Without a lot of water on the ground this year, large scale evaporative cooling could not happen.

The clear skies also explain the low minimum or overnight temperatures in the southern states.

Without a blanket of clouds, the heat from the day is lost to space, and temperatures drop overnight.

High pressure prevented cold fronts


But that is not all, Dr Watkins said: "We've also seen fewer cold fronts able to penetrate inland due to the slow moving and more southerly highs acting as a barrier to their normal northward progression".

So not only has high-pressure prevented rain in the north but it has also prevented the cold fronts which normally bring rain in the south during winter.

According to the climate scientists at the Bureau of Meteorology, the story behind the heat in northern Australia is more about what has not been happening.
In a standard winter there would be several south-easterly surges, bringing cold air into the tropics.

This year these surges were almost completely missing — blocked by that high pressure — until very late in the season.

So was the hot weather predicted?


The short answer is yes. The Bureau of Meteorology's 2017 winter outlook released in May, showed a high chance of exceeding median maximum temperatures.

Going into winter, high pressure conditions were likely.

Chance of exceeding the median max temp June to August 2017

"Our reasoning back at the time was that despite neutral ENSO and IOD patterns, the Pacific and Indian oceans were warmer than average, with cooler conditions in the eastern Indian Ocean near WA," Dr Watkins said.

Warm ocean temperatures are an indication of the energy available to the system, while cool temperatures in the eastern Indian Ocean would prevent the lift required to mix up and break down a growing region of high pressure.

What about the long-term warming trend?


Nineteen of the last 20 winters have now had average maximum daily temperatures above the 1961 to 1990 average.

Andrew King, climate extremes research fellow from the University of Melbourne, uses a range of computer climate models created all over the world to tease out the different factors causing extreme weather events.

His analysis of the factors behind this winter's record heat showed that the influence of climate change increased the likelihood of this winter's record warmth by at least щixty-fold.

Dr King said a very clear human influence could be seen in Australia's winter.

Spring outlook


According to BoM's new spring outlook released yesterday, it looks like spring is going to continue to be warmer than average for the north and southeast of the country.

While rainfall will be below average for south-west WA, it will be above average for south-east Queensland and far-east Gippsland.

No matter what comes in spring, winter 2017 is one for the record books.


New Zealand's NIWA has yet to put out a report but this was their prediction back in May

Their material is WAY less useful  than the Australian and designed to conceal as much as it is to inform


No comments:

Post a Comment

Note: only a member of this blog may post a comment.