QLD - DRY UNTIL SUNDAY, THEN A HEFTY RAINFALL EVENT DEVELOPS ACROSS THE STATE.

Another upper-level disturbance and a positive SAM phase looks to combine once again to bring about a broad rain event for large parts of the state leading to elevated severe weather risk and the chance of additional flooding for areas hit hard so far this year.


The La Niña that won’t quit!


Until Sunday, the weather is forecast to be generally dry for most inland areas, yes there are a few showers and thunderstorms about, but most areas should miss out and the cloudy skies should move on to the east without too much fanfare. A few showers and storms are possible at times over the far northern tip of Cape York and showers are possible along the coast down to about Proserpine.


The upper trough begins to approach from Sunday, and this is where we see cloud increasing for inland areas with scattered showers and thunderstorms emerging over northern and central inland areas of the state. Along the coast, the showers may increase with a separate trough deepening. This may have a stronger impact on the Central and Wide Bay coastal areas before spreading south and southeast.


The upper trough over the inland may deepen into a low and this is where we see the rainfall increasing. Models a little bit divergent on when this happens but this could occur from Tuesday with moderate to heavy falls developing for the inland and heavy rainfall increasing for the coastal areas south of Cardwell to the NSW border.


Rain and thunderstorms continue into the back of next week as the upper low slowly moves east to the Central Coast. The persistent rainfall and thunderstorms will lead to a flood risk increasing over the state as this system is slow moving, the moisture values well above normal and this promoting high rainfall rates.


Let's take a look at the latest data

FORECAST

Rainfall Next 10 Days

Rainfall is forecast to be mainly confined to the southern inland and about the far north and northeast in the coming 24hrs with troughs in both areas driving the wet weather. The trough in the south will move further east by the end of tomorrow taking a band of rain towards the coast, but it will be light and generally patchy. The trough then lingers offshore into the weekend with the rainfall potentially clipping the central areas before the trough deepens further in advance of an upper trough approaching from the west on Sunday. Rain should start to increase over the state later Sunday but more likely Monday with scattered storms delivering some heavy falls for some as the trough moves into western QLD. The rainfall over the east also increasing in coverage and becoming heavy as the trough moves back onshore being drawn in via the northeast to easterly winds. The wet signal then continues to grow Tuesday through Friday as the upper low moves into the eastern inland with rain ending from west to east gradually by the end of next week. Some areas could get falls over 300mm out of this event, mainly about the coast. Up to 100mm possible for many inland. The rain eases next weekend for the state but another system over SA and into the southeast could see another rain event come into the state at the end of the run.

Riverine Flood Risk - Wednesday-Friday

The heavy rainfall potential next week may lead to riverine flooding redeveloping over a large area once again, but it is more likely about the east coast between Cardwell and Coolangatta at this time. Flash flooding via thunderstorms also quite likely for inland areas.

Severe Weather Watch - Monday to Friday

The watch area has been extended southwards over the southern border and further west, but this risk will continue to chop and change, be weather aware and pay attention to forecasts.

MEDIUM TERM - May 11th-18th 2022

Rainfall Anomalies

Higher rainfall ongoing from the persistent easterly flow and a slow-moving trough in QLD. The above average rainfall may contribute to flooding potential through the region. The above average rainfall risk does exist for the remainder of the eastern inland thanks to heavy moisture in the region and the possibility of a trough lingering. The west will see more frontal weather with moisture streaming southeast ahead of frontal weather leading to broader rainfall events to continue. Seasonal values elsewhere for now, but for SA, watch the weather emerging through WA which could flip your rainfall fortunes quite quickly.

Temperature Anomalies

Bit of a mixed bag now being proposed across the country with a warmer tongue of air being trapped over the southeast in a broad northwest flow ahead of frontal weather bringing below average temperatures to the west of the country. Heavy rainfall and cloud cover over parts of QLD leading to below average temperatures but as you head north from there into the tropics, the warmer than normal weather is forecast to continue under an upper ridge.

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 can be found in the video but the cold outbreak over the southeast of the nation in the short term. Then the major rainfall potential over the northeast of the nation and east. Another rain event is possible over the southwest of the nation with frontal weather drawing in moisture from the Indian Ocean which could break that mini dry spell in recent days. That event offers better rainfall chances spreading across southern Australia into the medium term.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Reasonable moisture load over the northern parts of the nation but in the absence of low pressure in the short term, just patchy cloud and patchy falls expected into the weekend. But watch what happens over the north and northeast through the coming week with the medium term offering up moisture loads up to 400% above normal! Now if that was to occur, we would be seeing a monstrous amount of rainfall through the medium term but watching closely and not overly sold on that idea. Over in the west moisture loads will improve as we see the northwest jet stream bringing up rainfall chances. Drier air will likely be overwhelmed by moisture through this period so I do think many areas will see fairly reasonable chances for rainfall.


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 - the rainfall could become excessive given some of the moisture loads being forecast by the models so these numbers will change. Patchy falls in the coming days but the bulk of the rainfall is forecast from next week and the risk of flooding is moderate to high along the coast.

Plenty more ahead on the rain events to come in the medium term and a look at the Indian Ocean and the impacts building through Winter 2022. Thats coming up from 8am EST.



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