Possible NT cyclone for Xmas Day

An intensifying tropical low just over 200km north of Darwin off the Top End coast is expected to develop into a tropical cyclone early on Christmas Day. If it forms, it will be named Grant. A Cyclone Watch is current for coastal areas from Dundee Beach to Nhulunbuy, including Darwin.

While models are uncertain about the intensity and movement of this system, heavy rain is predicted for the north coast of the NT due to its slow-moving nature and proximity to the coast. Over 400mm is possible over the next few days with flooding likely.

If this tropical low develops into a tropical cyclone, it will be the third in the Australian region so far this season. Earlier in the month, Cyclone Alenga (named by Mauritius) drifted into the Australian Region of Responsibility but dissipated well off the coast with no impact on the west coast. The second of the season was a very shortlived Cyclone Fina in the Coral Sea, several hundreds of kiometres off the QLD coast.While this system had no direct impact on the coast, it is going to have a major influence on coastal conditions in southern QLD over the Christmas weekend. Cyclonic swell will coincide with a King Tide to produce waves of 8-10 foot extending to parts of northern NSW aswell. This will be a very dangerous time for holiday-makers wanting to go swimming, surfing and rock fishing, and there is a threat of beach erosion and inundation of low-lying areas.

Severe weather is also expected for south-eastern Australia during the Christmas period with a major thunderstorm outbreak! A hot, humid airmass is combining with a deepening trough to trigger widespread thunderstorms in TAS, VIC, southern NSW and the ACT on Christmas Day (including Melbourne and Canberra), moving north through central and northern NSW (including Sydney) on Boxing Day. Damaging winds, flash flooding and large hail are all possible!

Severe storms strike Perth with record breaking December rain!

Severe thunderstorms struck much of WA's southwest last night leading to widespread local flooding. Perth was soaked by a massive 44mm, with 37.8mm falling in just 46 minutes- this was greater than a 1 in 100 year event and, the equivalent of 3 times the December monthly average rainfall in just 46 minutes! It was also Perth's wettest December daily rainfall total in 60 years!

Surrounding areas were also awash with heavy rainfall Mandurah 69mm (heaviest December rain on record), Serpentine 37mm, Rottnest Island 36, Perth Airport 35 and Swanbourne 30mm.

The worst affected region was the Great Southern district with a large number of towns recording their heaviest December rainfall on record including: Narrogin (84.4mm), Wishbone (81.6mm), Dumbleyung (71mm), Rushy Pool (70mm), Katanning (61.8mm) and many others.

Williams had the highest rainfall in this event with a massive 125.6mm- the highest rain total ever recorded anywhere in the South West Land Division in December! This resulted in widespread flooding leading to evacuations.

The low pressure system responsible for the heavy rain and severe thunderstorms is moving eastwards today so rain has already eased for the west coast. Since 9am this morning, another 20-40mm has already been recorded in parts of the Wheatbelt, Goldfields and Southeast Coastal districts. As the system reaches the SA border it is expected to weaken, bringing patchy light rain to that state.

Widespread cloud cover due to rain and storms will capped maximums today with temperatures as much 13 below average for this time of year. Newdegate and Narrogin reached just 16 and 17 degrees today, respectively.

Summer is typically very dry for Perth with the city averaging only 12.8mm during December. This year has been very unusual for Perth and much of south-western WA with the city already receiving 75.8mm- now just 5mm short of its wettest December on record! 2011 marks a huge turnaround in rainfall from December 2010 when Perth recorded only 3.4mm.

First cyclone of the season in Australian waters likely to fizzle

Infared Image from Japan Meteorological Agency satellite MTSAT via Bureau of Meteorology- TC Alenga is the bright green/red system in the top left corner.

We could see the first tropical cyclone of the 2011-12 season in Australian waters with TC Alenga entering the Australian region of responsibility some time today.

It's situated in the central Indian Ocean and moving east southeast at 13kmh. It's expected to weaken on Thursday and Friday, and then dissipate well off the west coast of Australia due to unfavourable sea surface temperatures and atmospheric conditions. At this stage, the only influence that this system might have on the Australian mainland is rain for parts of the west coast like the Gascoyne/Pilbara due to increased moisture from the outflow of the cyclone.

I'll keep you posted!

Cold start to summer for Sydney!

Sydneysiders should make the most of today and Tuesday as they are likely to be the warmest days in a while!

Today is already shaping up to be a pleasant sunny day with 26-30 degrees with Tuesday forecast to reach 27-31 degrees.

After a warm night on Tuesday, the beginning of Wednesday will be a balmy 28-31 degrees before showers turn up from the late morning or early afternoon. There is also the potential for thunderstorms which may be severe. The wet weather will provide some cooling but a southerly change due on Wednesday night will lead to a significant temperature drop on Thursday.

Consequently, the first day of summer will feel like more like winter for Sydney with showers and just 20-21 degrees! Cooler than average summer temperatures in the low twenties are forecast to linger for at least another week from Thursday.

This cold and wet change for Sydney is part of a larger system that will affect most of NSW on Wednesday/Thursday. Of particular concern is the rain that is expected to fall over flood affected parts of north-west NSW with up to 50mm possible. While this rain event won't be as severe as last week, it is likely to lead to secondary flood peaks on some rivers.

Sydney bakes in hottest day this spring!

It was a scorcher in Sydney today with temperatures as much as 14 above the November average! The city reached a scorching 37.2 degrees today- a massive 13 degrees above the November average maximum and its hottest day so far this spring!

Penrith was the hottest in Sydney's west with 38.7 degrees. Other notable mentions include Sydney Airport (37.9), Bankstown (37.3) and Campbelltown (37.4).

It's not often that Sydney city reaches the mid-30s in spring, but it's even rarer for the city to be as hot as the western suburbs. The main reason why the city and coastal suburbs usually experience cooler conditions than the west on a hot day is the seabreeze. But today hot NW winds were gusting to 50-60kmh which was strong enough to effectively cap the seabreeze for most of the day, allowing the mercury to rise well above the forecast maximum of 32 degrees, and November average maximum of 24 degrees.

Relief!

Fortunately, relief arrived with a southerly change this evening dropping temperatures by around 10 degrees in 20 minutes! Overnight temperatures should dip below 20 degrees, much more comfortable than the 26-27 degree night that sleepless Sydneysiders sweated through last Wednesday.

Rest of the week?

The rest of the working week will be more bearable with a sunny 26-31 degree day on Tuesday. Wednesday is forecast to reach 25-29 degrees with a stronger southerly change and showers and storms during the afternoon. This will lead to a cooler 23-24 degrees on Thursday with one or two showers. Friday will warm back up to 27-31 degrees with a possible morning shower. Hotter weather is expected next weekend though, with temperatures potentially reaching the mid-30s once again.

Temperatures were even hotter in the western NSW today with Bourke sweating through 41.5 degrees.

Showers making way for a warm weekend in Sydney!

After its driest October in 4 years with just 37.4mm, Sydney has kicked off November in typical erratic spring fashion- sunshine, a southerly buster and widespread showers! Yesterday the city and west enjoyed  a sunny day with 24-27 degrees before a southerly change delivered winds up to 40-50kmh. Late afternoon cloud increased across the city with showers developing overnight.

Moist south-easterly winds have delivered the heaviest falls to coastal suburbs, especially the northern beaches, with lighter falls further west. To 9am this morning: Avalon 25mm, Cronulla 17mm, Chatswood 14mm, City 11mm, Homebush 10mm and Penrith 3.6mm. The mercury will also struggle to get to 20 degrees today across most suburbs. But this gloomy weather will be short lived!

Showers are easing and becoming isolated on Thursday afternoon with dry and partly cloudy skies on Friday with 23-35 degrees. The weekend is heating up on both days with a muggy 27-31 degrees on Saturday with a hot 30-34 degrees on Sunday, around 6-7 degrees above average for November.

Early next week it's expected to stay warm although less comfortable with rising humidity and unstable conditions with the chance of showers and storms. A trough is expected to trigger showers and storms through inland parts of NSW on Sunday and there is a chance that some of these showers and storms may drift towards Sydney as early as Sunday afternoon/evening.

Unseasonal rain and storms in WA!

Record breaking rain hits inland WA...
October ended with record breaking rainfall for normally dry central and northern parts WA. In the past week areas of the Interior and Goldfields picked up 50-100mm of rainfall while parts of the Kimberley have seen over 100mm.

Wiluna in the northern Goldfields received 38mm to 9am Tuesday morning, its heaviest November day of rain in over 100 years of records! Nearby Packsaddle Farm saw 64.8mm on the same day, its heaviest November day of rain since records began in 1995. Both Giles and Warburton in the Interior picked up over 70mm for the month, most of it in the last week, which is almost 5 times their monthly October average rainfall!

Many inland parts of WA would typically receive no more than 20mm on average for the month of October so this heavy rain is unusual for this time of year.

WA Rainfall totals (mm) Week ending 1st November 2011. Source: Bureau of Meteorology

Perth and southern WA next...
While the heavy rain and storms have been concentrated in central and northern parts of the state over the last few days, it will start to ease from tomorrow with the focus shifting further south. Widespread rain and potentially severe storms are expected for southern parts of the state on Thursday.

Perth is a chance to see a storm on Wednesday afternoon but the greatest risk is on Thursday with severe storms possible in Perth with the potential of flash flooding.

On Friday the rain and storms will shift eastwards across the state providing a break for Perth, but lighter showers are still expected in the city for the rest of the week from frontal activity.

Early wet season smashes rain records in North QLD!

The wet season has kicked in across northern QLD smashing rainfall records!

Cairns has just experienced its wettest October day in 67 years of records with 213.4mm falling in just 24 hours to 9am Wednesday. This completely overshadows the previous October daily rainfall record of 86.8mm set in 1964. It is now also the wettest October on record in Cairns.

Even though October marks the beginning of the wet season, such heavy falls are usually only experienced during the cyclone season- infact, the last time Cairns picked up this much rain was during Cyclone Yasi in February 2011.

But Cairns isn't the only one to get an early wet season soaking. Widespread falls of 100-200mm have also been recorded from Tully to Mossman in just 24 hours! This is on top of widespread 50-100mm falls the day before. In 48 hours, both Menavale and Goldsborough Valley have seen over 400mm of rain!

Wet season kicks in to QLD's tropics!

Last week it was SE QLD, but now QLD's North Tropical Coast is copping a soaking! Strong onshore winds are loading the coast with moisture while a low pressure trough sparks showers and storms.

Together, the two weather features have delivered massive rain totals to the region in 24 hours to 9am this morning: Menavale 199mm, Bolinda 113mm, Corsis 113mm, Goldsborough Valley 105mm, Gordonvale 98mm, Tully 74mm, Topaz 74mm.

Over the next 4 days, over 50mm is expected north of Townsville with over 100mm between Cairns and Cardwell. The rain is expected to ease from Thursday onwards.

So what can northern QLD expect this wet season? Last year, QLD experienced its wettest year on record largely due to one of the strongest La Nina's on record. It looks like La Nina is back for another so northern and eastern Australia can expect above average rainfall. But it is important to note that this La Nina is much weaker than last year so a repeat of last year's record-breaking rainfall is unlikely.

What about cyclones? The long-term average for eastern Australia over the November- April period is 3-4 cyclones. The latest seasonal outlook from the Bureau of Meteorology suggests a 65% chance of exceeding this average in eastern Australia, with an 80% chance of above average tropical cyclone activity across the Australian region this season.

Wild storms threaten QLD and NE NSW this week!

8 Day Rainfall 11/10/2001- 18/10/2011. Source: Bureau of Meteorology

In my most recent weather updates on Ten's Weekend News, I gave a heads up on some major rain and thunderstorm activity that's on the way to parts of QLD and northeast NSW this week. I thought I'd give you some more detail.

Last weekend, southeast QLD experienced fierce thunderstorms with wind gusts reaching as high as 139kmh in Oakey (that's as strong as a cat 2 tropical cyclone), widespread falls of 20-70mm (most that occurring over 1-2 hours) and almost 30,000 lightning strikes!

This week, we have the ideal atmospheric set-up for the most intense and widespread thunderstorm activity so far this season. Onshore winds are carrying humid, moist maritime air from the Coral Sea right over inland parts of QLD and northeast NSW. But it's not enough just to have a saturated atmosphere- you need a trigger. This "trigger" will arrive in the form of a low pressure trough. This trough will rapidly lift this warm, moist air high up into atmosphere where it will condense and form into cumulonimbus thunderstorm clouds.

On Tuesday and Wednesday, isolated showers and storms are likely on the QLD coast mainly in southern parts of the Central Coast and Capricornia districts, roughly from about Townsville/Bowen to Gladstone. Some falls may spread inland to affect the Central Highlands and Coalfields. But the main rain and thunderstorm activity will be from Thursday onwards with most of eastern, southern and central QLD and northeast NSW affected. These thunderstorms have the potential to be severe with flash flooding from heavy rain (there is so much available moisture!), damaging winds and large hailstones. By the end of the week, widespread falls of 50-100mm are likely, but some places may see this amount in the space of a few hours underneath isolated intense thunderstorms. Some river flooding may also develop.

Storms wet Wheatbelt, Perth misses out again!

It was a wet start to the week for WA's southwest as a low pressure trough triggered showers and thunderstorms.

The heaviest falls were through eastern parts of the Central Wheatbelt with Northam receiving 27mm- its heaviest daily rainfall since early 2009 and its heaviest October rainfall in 16 years! Other honourable mentions include Meckering North 36mm, Quadney 20mm, Cunderdin 13mm (24hrs to 9am Tuesday). And after receiving its heaviest rainfall in over 100 years with 53mm just one week ago, Wongan Hills got soaked by another 20mm yesterday. 

2011 marks a big shift in rainfall for WA's southwest. In 2010, the Southwest Land Division experienced its driest year in over 100 years. Many sites saw less than half the annual average rainfall, with some reporting their driest year on record. This year, many sites in the Wheatbelt including Northam, Wongan Hills and Merredin have either recorded average or above average rain so far this year.

Falls in Perth were a lot lighter with the city itself missing out altogether, highlighting the "isolated" nature of these showers and storms. Rainfall totals to 9am Tuesday included Weribee 12mm, Serpentine 4.4mm, Mandurah 2.8mm and Bickley 1.8mm. 

Today, the showers and storms are moving east to affect the Goldfileds, Eucla and southern Interior with 10-20mm possible. By tomorrow morning, the rain will have cleared to the east.

East braces for spring storms!

Rain and storms have been spreading east across the country this week delivering some of the biggest October totals in years.

The latest state to be affected is QLD with falls of 10-20mm from the northwest to southeast in 24 hours to 9am Thursday morning. The wettest was Bollon in the Maranoa district with 56mm, over a month's worth of rain (October average is 35.6mm). Other totals include St George Airport with 30.8mm, its heaviest October day of rain in 6 years and for any month since February.  Goondiwindi and Dalby both picked up 11mm.

NSW also received its fair share of rainfall with the heaviest falls in the Northern Tablelands (Glenn Innes 10mm, Windamere 15mm) and western NSW (Wilcannia Ap 15m, Booligal 19mm, Tibooburra 10mm, Broken Hill 9mm).

The system responsible for the rain and storms is a low pressure trough which is gradually tracking from west to east. Over the next few days, showers and storms will affect the eastern seaboard, including Sydney and Brisbane. Southeast QLD and northeast NSW are likely to see the heaviest falls. Severe thuderstorms with heavy falls, damaging winds and hail are possible. 

First rain in months for fire-ravaged Red Centre!

The Red Centre has welcomed its first rainfall since mid-July as a large rain-band moves from west to east across the country.

In the last 48 hours, many parts of the southern NT have picked up almost a month's worth of rain: Colyer Creek 27mm, Wigley Gorge 18.5mm, Alice Plaza 17mm, Yulara 16.6mm and Curtin Springs 14mm.

Isolated showers and storms are still affecting parts of the Barkly and northeastern Alice Springs district today, but will clear through the day as the low pressure trough and associated low continue to move east.

Sunny skies are returning to Alice Springs today with temperatures reaching the low thirties on Friday and the weekend.

Spring rain spreading across the country!

By the end of the week, most of the country will have seen rain, and it's all from one system! First it was WA, and now a low pressure trough is spreading rain and storms across the southern NT and most of SA. The moisture-ladden cloud will continue to spread east affecting western parts of NSW and QLD on Wednesday, before moving through much of eastern Australia during Thursday, Friday and the beginning of the weekend.

In the 24 hours leading up to 9am Monday, most parts of southwest WA picked up 5-15mm with Perth one of the only places to miss out. There were isolated pockets that received torrential downpours underneath intense thunderstorms. This included 53mm in Wongan Hills (Central Wheatbelt), its heaviest October rainfall in over 100 years!

Today, the rain and thunderstorm activity is affecting southern parts of the NT and most of SA. This rainfall comes as a relief to the Red Centre which has been ravaged by bushfires over the last six weeks. Widespread falls of 5-15mm are expected but once again, these isolated thunderstorms have the potential to be severe with heavy falls, damaging winds and small hail. The rain is likely to arrive in Adelaide during the late afternoon/evening.

On Wednesday/Thursday, rain and storms will spread across most western and inland parts of QLD, NSW, VIC and TAS, before affecting the east coast late Thursday/Friday and the weekend. Isolated pockets could receive heavy falls from thunderstorm activity.

Storms on the way for SE QLD!

Spring is almost here and we're already getting a taste of the type of weather it brings in southeast QLD- afternoon storms!!

This afternoon we'll see showers and storms developing in QLD anywhere east of the Northern Goldfields and Maranoa and Warrego districts, including Southeast QLD. The atmosphere is unstable and these storms have the potential to be severe with flash flooding and isolated falls of around 50mm, as well as large hailstones and damaging winds.

Last night, storms swept through parts of QLD bringing the heaviest falls to the Central Coast and Capricornia districts (Bingebang Weir 91mm, Mt Christian 80mm, St Lawrence 51mm, Prospect Creek 43mm), with around 10-20mm in parts of Maranoa and Warrego and Darling Downs (Toowoomba Ap 18mm, Yuleba 19mm, Dalby 12mm). This afternoon, the Southeast Coast will also come into play with Brisbane likely to be affected.

Journey to the centre of the earth!

Reporting on severe weather over the last few years has brought me very close to the extremes of nature. From the worst bushfires to the worst floods in Australia's history, I've seen and heard how intense, terrifying, and unrelenting the weather can be. The sounds can be deafening and the images, frightening.

Last weekend, I experienced the incredible force of nature again, only this time it wasn't coming from the sky, but the earth. Mt Yasur volcano on Tanna Island in Vanuatu is the most accessible active volcano on the planet and I couldn't believe how close I was able to get to the roaring earth and spitting lava. The blast of lava sounded like bombs exploding and the fireworks display of fire, lava, rocks and smoke was extraordinary.

The journey to the volcano is as rewarding as the volcano itself. As you 4WD through the lush jungle, you see villages full of the smiling happy faces of locals who appear genuinely excited and happy to see you. Children swing from trees or wave shyly from the road, amongst wild horses and the traditional huts they live in. It's hard to believe that all of this is only a 3 hour flight from Sydney.

The road to Mt Yasur is more like a dirt track with enormous potholes and takes about 2 hours each way. As you approach the volcano, vegetation and villages disappear to reveal a stark, grey moonscape plain of volcanic ash, with Mt Yasur blowing smoke and roaring in the distance.

As the 4WD descends up the volcano, steam leaks out from the volcanic earth. Just before the short walk up to the volcano rim you'll find a post box- the only one on a volcano in the world!

The best time to view Mt Yasur is in the late afternoon/evening when the colours are most pronounced. I was lucky enough to see it at Level 2 which is a lot of activity yet still safe enough to view. If the volcanic activity reaches Level 3 it is too dangerous to go up and see it.

Big week of rain for southwest WA!

It's set to be a big week of rainfall for southwest WA thanks to a number of cold fronts crossing the region. The most significant of these fronts is hitting on Tuesday morning and it's expected to deliver as much as 25-50mm for the west coast including Perth, with 5-15mm possible for the Central Wheatbelt favouring the western half. Most of this rain will occur during Tuesday morning with isolated showers during the afternoon. The bad news is that this front is likely to be accompanied by severe weather. Damaging winds are possible ahead the front on Tuesday morning with squally storms potentially generating powerful winds also. Damaging winds with gusts over 90kmh are strong enough to bring down trees and power lines.

The next front is due on Thursday with another 5-15mm expected for the west coast and lighter falls further inland. By the end of the week as much as 50-100mm could fall on the west coast with anywhere between 10-20mm for the Wheatbelt.

This comes on top of heavy rain just last Friday where Perth saw 57mm! This brings Perth's June rainfall so far to 128.2mm, just 6.5mm short of the June monthly average. Needless to say, many parts of the southwest will have recorded above average rain for June by the end of the month.

Finally, some more rain for Perth and WA south-west

After its driest year on record in 2010 and below average rainfall so far this year, much of WA’s southwest is in desperate need of rainfall. But I have some good news! Next week a couple of strong cold fronts will bring a wet change to the southwest, but this may be accompanied severe weather.

On Monday, it’s a very “winter-type” set-up with a strong cold front bringing rainfall, windy conditions (potentially damaging winds with gusts over 90kmh) and severe thunderstorms. Showers will continue on Tuesday with onshore winds before another cold front brings more rainfall on Wednesday.

Between the two systems, widespread falls of 25-50mm are possible for the Perth area with 50mm plus for towns south of Perth such as Bunbury and Busselton. Rain totals will drop rapidly heading inland with 1-20mm possible in the Wheatbelt, favouring the western side.

Ahead of this wet and windy weather, try and tie down any loose items and be prepared for a wet and slippery commute to work on Monday.

Extreme cold chills the southeast

Many cities and towns in south-eastern Australia shivered through their coldest morning so far this year. Sub-zero temperatures brought frost to places including Glenn Innes and Young with -5, Camden with -1 and Tamworth with -2! Even Richmond (NSW)and Charlesville (QLD) woke up to their first frost for the year.

Day-time temperatures are also well below average across much of southern and eastern Australia. Check out the following forecast maximum temperatures today!

- Toowoomba, QLD: 16 degrees (4 below average)
- Mt Isa, QLD: 22 degrees (6 below average)

- Orange, NSW: 6 degrees (8 below average)
- Young, NSW: 10 degrees (8 below average)

- Ballarat, VIC: 7 degrees (7 below average)
- Melbourne, VIC: 13 degrees (4 below average)

- Hobart, TAS: 11 degrees (3 below average)
- Launceston, TAS: 12 degrees (4 below average)

- Renmark, SA: 16 degrees (4 below average)
- Adelaide, SA: 16 degrees (3 below average)

And if this isn't bad enough, icy south-westerly winds will make it "feel" a few degrees colder!

Snow has also been coating the NSW and VIC slopes and ranges. Most alpine areas have had around 10cm of snow but I've also had reports of 15-20cm at Mt Buller this morning (See pic by Tony Harrington above).

The cold snap is here to stay for the rest of the week and for some places, tonight may be even colder than last night so rug up!

Sydney's Weekend Washout!

It has been raining non-stop in Sydney this weekend with massive rain totals recorded between the Hunter and South coasts over the last 2 days. So where is this deluge coming from and when will it stop?!

Well, the atmosphere is completed saturated and when it's like this all it needs is a "trigger" for a heavy downpour. In this case, the "trigger" is a small-scale low pressure trough that formed off the NSW coast. The very moist air has been feeding into this trough causing widespread torrential rain in Sydney, the Hunter, South Coast and Illawarra. With so much heavy rain falling over a short time period, flash flooding is likely.

Over the last 48 hours, the heaviest falls have generally been in coastal suburbs, closest to this trough. In 24 hours to 9am Sunday morning, we've seen widespread falls of over 100mm with as much as 166mm in Little Bay, it's heaviest March rain since 1975. Other notable falls include:

Avalon- 139mm
St Ives- 179mm
Turrumurra- 175mm
Belrose- 137mm
North Manly-130mm
Sydney Airport- 100mm

Further south, Albion Park recorded 137mm, Wollongong 129mm and Barrengarry 210mm!! The rain has been lighter further west with up to 50mm in the Warragamba catchment area. Considering how dry it has been, this is unlikely to lead to any significant rises.

So- what next? Heavy rain will continue during Sunday, easing later as the trough moves away. But heavy rain is likely to return on Monday as another low pressure trough comes in from the west. The wet weather should start to ease on Tuesday.

Cyclone season ramps up with monster Yasi on the way

Anthony hits QLD coast
TC Anthony hit the coast around Bowen on Sunday night and has since weakened into a tropical low. Anthony delivered damaging wind gusts of 124kmh to Hamilton Island and heavy rain to areas directly south of the cyclone around Mackay with widespread falls of 100-300mm. This has lead to minor-major flooding in the Pioneer catchment. This system is moving in a south-westerly direction and continuing to bring rain to inland QLD.

The monster TC Yasi is next…
But a much larger and powerful TC Yasi is now threatening QLD as not only is it expected to be stronger than Anthony, but it is also a lot bigger meaning that its impact will be much more widespread across QLD. If you look at the satellite image above captured from http://www.weatherchannel.com.au the now ex-TC Anthony is the circular cloud near Townsville, and TC Yasi is the monster to the right spiralling near Vanuatu. It dwarfs Anthony in size and could reach category 4 status as it approaches the QLD coast. A category 4 cyclone is a Severe Tropical Cylone with “very destructive winds” that can gust at 225-279kmh over open flat land. Winds of this strength can destroy and blow away caravans and lead to significant roof loss and structural damage. TC Yasi may weaken as it approaches/crosses the coast due to friction and at this stage its expected to make landfall late Wednesday/Thursday bringing widespread heavy rain and possibly wind gusts of over 200kmh. Since the system is so large its impact will extend across a very large part of the QLD coast. Gale force winds and heavy rain could be felt for 100's of kilometres anywhere north of the sunshine coast.

Is Yasi's path unpredictable?
Contrary to popular belief, not all cyclones are "unpredictable." A TC will respond to the environment around it so if the winds in and around a cyclone are all over the place, a cyclone's path may be erratic and difficult to predict. However if there is a well established direction of environmental flow, the prediction of a cyclone's path can be made with a lot more certainty. In the case of TC Yasi, there is a well established flow of easterly winds so it can be said with some certainty that these winds will carry TC Yasi towards the QLD coast. Since a coastal crossing is still a few days out, it is difficult to predict exactly where TC Yasi will hit.

Where did the name “Yasi” come from?
Various meteorological organisations are responsible for naming TC's depending on where in the world they form, and there are various conventions for TC naming too. TC's that form in Australian waters are named by the Bureau of Meteorology using a set list that runs in alphabetical order. So with Anthony and Bianca most recently forming in our waters, you might be wondering why this TC is called Yasi as opposed to a name starting with "C". Well, since TC Yasi formed out of Australian waters it was named by the Fiji Met Service. They also follow the convention of naming TC's using a set list in alphabetical order, so after naming Ului, Vania and Wilma, Yasi was the next name on the list. When TC Yasi enters our waters it keeps its Fijian name to avoid confusion. The next TC to form in Australian waters will be Carlos.

Double Cyclone Trouble for QLD

---UPDATED AT 6.30AM SUNDAY QLD TIME--- The intensity and movement of cyclones can change rapidly so make sure you check in with the Bureau Of Meteorology regularly for the latest warnings.

The QLD coast is on alert with the prospect of two tropical cyclones making landfall in just the space of a few days.

At 4am local time, TC Anthony was a weak category 1 system and situated approximately 600km ENE of Townsville in the Coral Sea. Anthony is forecast to continue its southwesterly track today and make intensify slightly into a category 2 system as it approaches the QLD coast. A Cyclone Warning continues for coastal and island communities from Lucinda to Proserpine. A Cyclone Watch continues for coastal and island communities from Innisfail to Lucinda and Proserpine to St Lawrence. Damaging wind gusts may develop for coastal and island communities between Lucinda and Prosperpine late Sunday, with Destructive winds gusts near the cyclone centre as it approaches the coast early on Monday morning. Heavy rainfall and local flooding are expected to develop near and to the south of the cyclone, as far south as Sarina, as it approaches the coast some time overnight Sunday.

There is also a low to the north of Fiji that is forecast to develop into a tropical cyclone and move into the region on Tuesday. This system may also impact the QLD coast. There are some indications that this system could be a lot stronger than Anthony, but considering the system hasn't formed into a cyclone yet, it is too early to be certain of this system's intensity or movements.

Why is this tropical cyclone season so active?
One of the strongest La Nina's on record continues to influence the climate of the Pacific Basin. Apart from contributing to above average rainfall across northern and eastern Australia (which has already been experienced in unprecedented amounts leading to record flooding), La Nina events are also characterised by a higher than normal number of tropical cyclones during the tropical season from November to April.

Another climate pattern that influences tropical cyclone activity in the Australian region is the Madden-Julian Oscillation. It is currently out of the Australian region but it may return in the middle of February and this could increase the tropical cyclone potential at this time.

Cyclone season taking off!!

----URGENT UPDATE - TROPICAL CYCLONE BIANCA HEADING TO PERTH----

We're in the guts of the official Australian cyclone season, and so far we've had 7 tropical cyclones in Australian waters with the most recent being Bianca off the WA coast. Cyclones Vania and Wilma didn't make the count since they were officially out of Australian waters but they impacted our eastern seaboard with powerful swell.

This week is particularly active in Australian waters with three systems that I'm watching closely:

----A dramatic change in the movement and intensity of Bianca is expected. See below----

Bianca formed early on Australia Day, reaching Severe Tropical Cyclone status on Thursday 27th January when it became a category 3 system. Bianca now lies off the WA coast and continues to move in a south-westerly direction away from the coast. Bianca is forecast to gradually weaken as it takes up a southerly track overnight on Friday, changing to a south-easterly direction on Saturday. Early on Sunday Bianca is expected to reach the southwest corner of WA and could maintain Tropical Cyclone strength as it makes landfall. If this situation eventuates, damaging winds up to 120km/h may occur between Jurien Bay and Albany. Ocean conditions will also become dangerous. A cyclone watch is currently in effect for this region.

Anthony has re-developed into a Categoty 1 Tropical Cyclone and is situated in the central Coral Sea. It's expected to take a more N/NW track and could make a coastal crossing between Mackay and Cooktown late Sunday/early Monday.

Wilma is a category 3 Severe Tropical Cyclone well offshore near Norfolk Island and will only have a an indirect impact on Australia in terms of generating powerful swell to the eastern seaboard this weekend. Waves won't necessarily be massive but the swell will be powerful and energetic making for dangerous surf, beach and fishing conditions.

Crazy Sea Fog blankets Bondi on Australia Day!

With a forecast of 42 degrees in Sydney's west and 33 degrees for the city today, you'd be forgiven for thinking that it's a perfect beach day for enjoying Australia Day! Afterall, it's set to be the city's hottest Australia Day in 31 years and Penrith's hottest day all summer!

But while it's turning out to be an absolute scorcher, the hot tropical airmass that's causing all of this heat has also contributed to a strange thick sea fog across some of Sydney's most popular beaches, on what is arguably one of Sydney's most popular beach days of the year!

So how has this sea fog formed?
Well, sea fog is also known as "advection fog" which refers to the movement of warmer air over a cooler surface. The hot airmass which is being drawn in from the tropics to Sydney today by northerly winds (and causing Darwin-like humidity!) has been carried over the cooler waters of our beaches. Now the contact of this hot and humid airmass with the colder water has caused the air directly above the sea surface to cool. Cooling of the air causes the water vapour in the air to condense into liquid droplets which we see as fog! It also helps that the winds are light so there's nothing to push the fog away.

When will it go away?
Later today when the sea breeze develops winds will tend N/NE'ly blowing the fog parallel to the coast, so visibilty should improve. Winds will also become stronger which should enhance mixing of the lower atmosphere, helping to dissipate some of this fog, although it could remain hazy. We have a southerly change coming in this evening which will bring a "relatively" cooler and drier airmass through Sydney so sea fog is less likely tomorrow. I say "relatively" because this southerly won't bring much of a temperature drop to Sydney tomorrow. It's not until Friday that temperatures will become more bearable with a forecast 25 degrees for the city and 27 degrees for Penrith.