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.