QLD - RAINFALL SET TO INCREASE FRIDAY AND HEAVY OVER PARTS OF THE COAST. DRIER INLAND FOR NOW

The wet weather just keeps on keeping on for the coast with some moderate showers forecast to persist tonight and into tomorrow in advance of an upper trough deepening during the weekend. Moisture via the easterly wind profile is forecast to feed this trough, but the trough itself could also feed off the upper level moisture from the WA system which is being drawn through the jet stream.


Areas of rain with thunderstorms are forecast to develop later tomorrow through Saturday with locally heavy falls possible between Yeppoon and Noosa. The rainfall could lead to flash flooding but the risk is now looking shorter lived with the upper trough leaving the region during Sunday.


Unstable and fresh northeasterly winds will follow the trough and the showers are forecast to continue across the coast and adjacent inland. Some thunderstorms are forecast to develop over the inland next week but falls generally patchy away from the coast.


As the winds turn into the north during mid next week and the ridge begins to work in from the Tasman Sea, it is likely that showers should decrease. Cloud at this stage should increase over the inland with widespread showers developing over the interior and through SA, some of this could pass through southern and western QLD during the latter part of the week into the weekend.


Some indications that there could be a significant cloud band bring rainfall chances up over Central Australia which could sweep through QLD at the end of the month but this is a signal for now.


Let's take a look

FORECAST

Rainfall Next 10 Days

Rainfall is forecast to remain fairly coastal over the coming 4 days with onshore winds but some of the showers could increase over Central areas an upper trough moves into the east coast, deepens, and feeds off the moisture that is in place via the onshore winds and the upper level moisture via the jet stream from the west. A period of heavy rainfall leading to flash flooding is possible about the Sunshine Coast, Wide Bay and Capricornia. The rain eases back to showers on Sunday for these areas and the showers continue most elsewhere along the coast. With the broader northeast flow developing over the weekend and into next week, there could be moisture drawn through the inland with showers developing, maybe some thunder from mid next week. The air is warmer than normal and will support thunderstorm development looking at the atmosphere. A stronger front pushing through the southeast will help to sweep the high towards NZ, and once this happens, the winds will veer into the north and drier weather could develop along the coast. A band of rain will be extending across the nation from northwest to southeast next week impacting WA, SA and VIC then into NSW. This may spread into the west and south at the end of the month if the cloud band maintains integrity. But there is every chance we could see a drier westerly pattern unfold with little rainfall over the medium term and the wet weather staying further south. So, plenty to watch through the coming weeks.

Heavy rainfall with an upper trough developing later tomorrow through Saturday into Sunday with conditions easing into early next week. Some light showers will continue into Wednesday morning with drier weather developing through the latter part of the week. There may be some rainfall coming close to the western parts of the state during next weekend with an interior cloud band.

Severe Weather Watch - Flash and Riverine Flooding Saturday to Sunday

A brief but fairly dynamic period of weather is forecast to produce scattered heavy rainfall totals leading to flash and riverine flooding as deep moisture is lifted to full potential. Rainfall rates which could support flash flooding of saturated catchments will place remote and rural communities under threat from further inundation following flooding last weekend. The risk should peak during Saturday and into Sunday before the rain breaks to showers during the day on Sunday. Residual flooding is possible into early next week. Remain weather aware if you live in the yellow zone.

Flash Flood Forecast - Saturday to Sunday

Flash flooding through Saturday through to Sunday with rainfall rates of 30-50mm/hr possibly more with a trough deepening near the coast. Some flash flooding is possible along the coastal areas between Yeppoon and Tewantin at this time. Some lower chances north and south of here with heavy coastal showers and some local thunderstorms about the coast. With the onshore flow and the upper trough and warmer than normal SSTs, rainfall rates could surprise in the lower zones between Mackay and Crescent Head so stay weather aware.

Riverine Flood Forecast - Saturday to early next week

The most widespread and heavy concentrated falls are forecast between Yeppoon and through to around Tewantin where this zone could see 100-200mm of rainfall in the period leading to minor to moderate flood peaks redeveloping once again. So be weather aware if you are in this zone.

MEDIUM TERM

May 26th-June 10th 2022

Rainfall Anomalies

Rainfall anomalies are forecast to be quite elevated across the northwest of the nation and this spreading southeast via the jet stream in advance of an eastward moving long wave trough south of SA, this taking the wet weather throughout the southeast. Rainfall expectations at seasonal levels most elsewhere.

As we move into Winter, the rainfall should continue to evolve along the jet stream with the higher chance of above average rainfall through the northwest of the nation and extending southeast once again along the jet stream and into the southeast. Some well above average rainfall near the northwest coast of WA is likely. Some showery winds with above average falls for June over Cape York are possible.

Temperature Anomalies

The warm end to the month for the east and north extending to the east coast continue to strengthen on the signals. The colder bias over the northwest a very high chance of occurring under thick cloud and colder westerly winds and rainfall moving through. The amplification of the pattern representing the temperature spread across the nation, which could support severe weather across the country.

The cooler bias following the strong cold front and rainfall event moving through the southern third of the nation will send a large plume of southerly winds through the country during the first week of June, with further rainfall developing out west with another cold front, cooler than average weather continues for the western interior. Warmer weather with elevated humidity looks reasonable over the tropics.

DATA - Refer to the video for more context behind the forecasts and why models are all over the shop from run to run


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

The major weather systems to watch will be out over the west with a few fronts in the coming week, the major rainfall event along the east coast of QLD could produce locally heavy falls and thunderstorms. The high pressure over the southeast dominating the weather across the country with the system determining the influence frontal weather will be having on the nation as we move through the short and medium term. The latest GFS showing more bias for rainfall over the east coast and out west, but this morning it had a freer flowing pattern of rainfall moving from west to east across the country. That in itself shows you that using the broader data sets for forecasting is key. So don't rely on those apps, look at all broader information here to help guide your understanding.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Moisture spread like this morning is largely unchanged compared to this morning, but as mentioned this morning, the placement of low pressure in relationship to that moisture determines where the rainfall evolves and becomes heavy. The higher moisture levels sit over the western parts of the nation and also across the east coast at the moment but I am not so sure on the deeper rainfall event along the east coast just yet and that moisture may end up staying further offshore with ridging holding out on that moisture being lifted into widespread falls. Moisture is still expected to spread across the country from west to east at this time.

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 - make sure you catch the rainfall update tonight to see the broader data sets. They offer more reliable information related to rainfall events and I can assure you this WILL CHANGE from the next run and tomorrow morning again.


More coming up from 8pm EST with a look at the models and rainfall.

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