A very active period weather continues to unfold over the state as a deep upper trough along the QLD coast drives heavy rainfall and thunderstorms with a flood risk increasing tonight. An upper low over the SW of the state is forecast to move into the moist and unstable air in place to lead to more widespread rainfall and thunderstorms over inland areas with the risk of high impact flash flooding and further riverine flood peaks through the coming days.

It is a very dynamic and dangerous period of weather for many locations.

The weather is forecast to ease from the northwest and west through the latter part of this week with the trough and possible low over SEQ beginning to move offshore as we start the weekend.

So, the severe weather risk should subside by the weekend with drier air moving over the interior. However, the east may remain showery and there have been some adjustments on the forecast modelling to keep the moisture lingering over the southeast and northeast with persistent showers.

Over the southeast next week, also some suggestion we could see another upper level disturbance, this time move through NSW, interact with this moisture, if that were to occur, this would increase rainfall chances for the southern and southeast of the state next week but will wait and see.

Let's take a look


Rainfall Next 10 Days

Well as forecast from last week, the heavy rainfall is forecast to unfold overnight and through Wednesday with heavy rainfall leading to flash and riverine flooding and severe storms in scattered pockets of the southwest tonight continuing through Wednesday. Some of the storms deliver high impact flash flooding in areas where lighter rainfall is forecast. But the most concentrated rainfall extends from the Central West, through the Coalfields, Highlands and into the east coast from Cardwell south to Noosa. Widespread rainfall will impact most districts over the coming days. The rain eases from the north and west during Thursday and clears eastwards Friday and hopefully some luck, we lose the system on Saturday. But some of the modelling as mentioned throughout today, wants to keep the rainfall in place for the southeast and south of the state with showery weather also ongoing over the northeast tropics. The wet signal courtesy of the positive SAM phase that looks to have a second peak this week, which would play out early next week. Something to watch.

Southern QLD

The rainfall is expected to be excessive along the southern inland for this time of year with the risk of flash and riverine flooding. Heaviest rainfall is expected over the coastal areas during Thursday into Friday with the potential for a deeper low forming on the trough over the Wide Bay and Burnett and SEQ Inland which could see rainfall totals forecast up to 500mm in some spots if this idea gathers more strength.

Southwest QLD.

Rainfall in this zone will likely be highly variable and determined by the position of thunderstorm clusters and these cannot be forecast with any great skill ahead of time. But the higher rainfall odds are positioned the further north and east you go from this region.

Thunderstorm Forecast Wednesday

Thunderstorms are forecast to emerge overnight and through Wednesday over the Central West, Northern Interior and about the east coast north of Gladstone during Wednesday with heavy rainfall and flash flooding the main concern. Another cluster of thunderstorms is forecast to develop over the southwest during tonight and during Wednesday with the risk of heavy rainfall leading to flash flooding and a lower risk of large hail and damaging winds.

Severe Weather This Week - QLD

The severe weather continues to unfold with areas of heavy rainfall and severe thunderstorms being observed during the past 24 hours and that activity is expected to increase further this week with a deep moisture profile and slow-moving low-pressure systems moving through the eastern inland of the nation. Be weather aware that the weather is forecast to result in dangerous conditions being observed. Not everyone will get clobbered in the watch zone, but it is important to remain weather aware and to follow the official warnings. Ensure you have multiple ways to recieve those official warnings.

Flash Flood Risk - QLD

The flash flood risk continues today through to about Friday with the most severe and dangerous flash flooding expected to move out of the inland during late Wednesday and contract along the coast during Thursday and Friday before clearing into the weekend. Some locations could record 500mm of rainfall for the period along the coast, and as observed overnight, some areas could see 150mm in 24hrs or more. That rainfall over the inland of QLD will contract east during later tomorrow.

Riverine Flood Risk - QLD

Rainfall, some heavy, has seen flooding develop over parts of inland QLD with some areas recording 100-200mm of rainfall so far. The heavy rainfall will continue, and the region over central and coastal QLD will likely see the higher risk of flooding in the days ahead. Some locations could be placed into major flooding and this flooding will linger for a number of weeks over the inland of the country. Any additional heavy rainfall threat over the interior into June will continue to keep flooding alive for the months ahead under current guidance.

MEDIUM TERM - May 17th-24th 2022

Rainfall Anomalies

Rainfall signals for the northwest of the nation are increasing in response to deep moisture being propelled through the jet stream leading to areas of rain and thunderstorms becoming more widespread for WA. This moisture will spread throughout the nation, but the lack of strong trigger means that rainfall totals should be lighter through SA and into the southeast, however this could change if frontal weather is more in phase. Over the east, the increasing signals of a positive SAM phase developing through the coming week, this may lead to more above average rainfall for the eastern third of NSW and QLD. The risk of above average rainfall is higher over in the west this time around.

Temperature Anomalies

No change to the guide from yesterday with a warmer bias over the north with excess humidity in place leading to the chance of dry season showers. Cooler bias over in the southwest and west with persistent cloud cover. The warmer bias in the east is conditional and is based upon higher moisture levels leading to above average overnights and daytime temperatures, especially if the weather is drier than forecast.

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 at the top of the page but I will point out that the weather is forecast to turn more active over the coming days as advertised and the latest risks discussed there. The weather over the west also becoming more active in the coming days with a strong cold front moving through. Then that system could be moving through southern and southeast areas of the country. This system will help knock out the high moisture and severe weather risks over the east by the weekend and cooler weather resumes and a more seasonal spread of temperatures and rainfall can be expected next week. The focus of the wettest weather still looms over the eastern third of QLD and NSW in the medium term but more interest from me is in the west of the country, with a deeper moisture plume coming through the jet stream into the western and central areas of the country which could lift rainfall chances across the nation, WA, SA and VIC could fair better in this scenario.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Widespread above average moisture levels are currently in place across much of the nation and entering the west of the country. It won't be until we see the western system move east, that it will help to knock out the deep moisture over the east and contract it northwards and then clears it away. Then we watch the persistent influx of moisture from the Indian Ocean and see whether that has some major impacts on rainfall rates over the west, southern and southeast of the nation as we move through into next week and the medium term. There are some weak rumblings for a large-scale rain event in the east which has been popping up on some models into the 21st onwards but I am not convinced of that just yet.

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 GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis

A closer look in - extreme rainfall is expected for some communities tonight with the peak forecast to ease from later tomorrow and contract east and south Thursday and clear Friday. By the end of the week, the inland is looking much drier. Disregard the secondary event that is making the rainfall projections go off tap. I think that will be gone next run.

More coming up from 9pm EDT with a look at the models and rainfall, I will only share information that is in reasonable agreement as too much is too confusing and I only want to share what is plausible at this time, so stay tuned for that.

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