The weather has been very wet in recent weeks with the build up of tropical moisture with a deep trough finally meeting the moisture and warmer air leading to widespread rainfall and thunderstorms. Record rainfall is forecast to ease over much of the state tonight with flooding slowly receding once again this week.

Thunderstorms will continue for inland areas with a slow moving trough and moisture in place, some of those storms could be severe, with heavy rainfall leading to flash flooding the main concern.

As we track through towards the weekend, there is the chance of showers and thunderstorms increasing once again. The thunderstorms activity over southern areas of the state could be severe with heavy rainfall and damaging winds once again a chance. This will likely be different to the previous event, where the thunderstorms are more cellular in nature and a band of rain to follow will be moderate and not as heavy as what we have experienced.

The showers along the east coast in onshore winds will continue with some moderate falls, but they could turn heavy again over the FNQ coast. The trade winds will likely ease through to the weekend but they may freshen again next week as another wave of low pressure forms in the Coral Sea.

A new upper trough is forecast to move in from NSW on Sunday and this could linger next week, linking up with the moisture leading to areas of rain and thunderstorms for southern or southeastern parts of the state. There may be further amplification to this system with widespread rainfall and thunder possible returning to western districts.

Lets take a look


Rainfall Next 10 Days

Rainfall is forecast to be widespread overnight and into Wednesday but the rainfall intensity is starting to ease over the next 24hrs. The rainfall is likely to turn more scattered in the form of showers and thunderstorms near a trough deepening over the western districts once again. This trough will meander out west before turning east and southeast as a front begins to move through the southeast of the country, kicking the trough further east over the southeast and eastern areas by the weekend. A few showers and thunderstorms are likely to emerge through the weekend but they could turn more widespread if the front sits more northwards than what is currently forecast. Next week, an upper low is forecast to form near the NSW and QLD border with an upper trough moving out of SA. An easterly flow is set to develop once again and feed the unstable air leading to widespread rain and thunderstorms across the state. This event could be another severe weather event for southern and western areas so will need to be watched closely. Heavy rainfall may redevelop for the tropical areas, and more on that can be found in the tropical update.

Thunderstorm Forecast Wednesday

Thunderstorms are forecast to develop along a trough that will hang back over western areas during Wednesday afternoon. Storms have the chance of becoming severe with heavy rainfall leading to flash flooding the main issue at this time but the risk is lower than previous days.

Flash Flood Risk Wednesday

Heavy rainfall rates of 50mm/hr possible with thunderstorms during the afternoon and evening over western areas.

MEDIUM TERM - May 4th- 11th 2022

Rainfall Anomalies

Rainfall signals remain above average for large areas of the north and east as well as pockets of the southeast and southern inland of the nation. Moisture persisting over the tropics likely being drawn into the jet stream will be lifted by areas of low pressure through the nation leading to above average rainfall. This pattern has been repeated time and time again this year and we are likely to see more of this occurring. A cloud band developing over northwest WA is possible if we see a tropical incursion approach the northwest of the country.

Temperature Anomalies

Not much change from yesterday with the cooler and drier air over the southwest leading to the below average temperature smear. Over the northern tropics, the above average humidity values will lead to above average temperatures during the days and nights with the above average rainfall signal. The east, higher humidity should keep things relatively seasonal, but wet and humid.

DATA - Refer to video for more information and the model comparison and context about all the forecast products you see from me.

00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks

More details in the video but we are staring down the current rainfall event in the east, a rainfall event to come over the weekend through southeast and eastern parts of the country with a cold front running into the moisture. Deep moisture to return next week lifting the chances of follow up rainfall for the southeast inland of QLD and northeast inland of NSW. More rainfall could emerge for SA with an upper system next week. The rainfall over the tropics also tending above normal for this time of year and that could run through the northwestern interior with above average rainfall chances as well. The southwest will be dealing with cold fronts and the possibility of moisture being drawn into the westerly wind belt from the Indian Ocean into the medium term.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The values are anomalous over the east and that has lead to the excessive rainfall of recent days, but you can see the moisture easing in intensity over the next week. But further moisture may be drawn in from the northeast and north of the nation southwards next week into another upper level system. This could set the scene for widespread follow up rainfall. The tropics could be covered in very high moisture content into dry season leading to more above average rainfall. That moisture if it gets to the northwest of the country, could be propelled south and southeast through the nation via the jet stream.

00Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z CMC - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z Euro - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis

A closer look in - not so sure the rainfall output across the state is set in stone, so watch closely in the coming days regarding the weekend event and then more rainfall with an upper level system next week.

More coming up from 8am EST tomorrow. Have a great night.

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