The heavy rainfall and flooding issues do continue in parts of QLD this evening and for the coming days as we track a trough and upper low which are both weakening further east.

Rainfall rates will remain above average thanks to humidity values being at about 300% of normal and this means the atmoshere is a loaded gun to produce a lot of rainfall in areas where the conditions are favourable.

Thunderstorms and clusters of convection seem to be driving the heaviest of the falls amongst a broad cloud band, that has been the guidance for this system and remains to be as we move into the end of the life cycle of the feature by Saturday.

Rainfall is contracting further east and south as the whole system gets shoved east by an approaching cold front over the Bight, this system is running into the southeast bringing rainfall there, but acting to steer the system out of the region.

Elements to watch in the next week beyond this feature will be the emergence of an upper level system over the southeast or into NSW. If we can get a deep moisture feed via the easterly winds or the jet stream injecting moisture into any area of instability in the east, this will trigger additional heavy rainfall threats.

Models have been hot and cold on this idea for the period beyond about the 19th of the month so watching closely. But I would not be surprised if we see more severe weather threats coming through this period. I do think the coverage of severe weather would be further south and over NSW this time around but will watch carefully for trends as we do most days here.

Lets take a look


Rainfall Next 10 Days

Rainfall is forecast to remain above average over the eastern 2/3rds of the state tonight and the heavy rainfall is forecast to contract very slowly to the east as we move through the coming 2 days, thanks to the front that is approaching WA today, meandering through the Bight and reaching the southeast by Friday. Once that front hits the southeast, then the very deep moisture will be propelled offshore with the rainfall coverage easing. Inland areas should return to mostly dry by late tomorrow with the bulk of the rainfall, some heavy, continuing over the southeast and eastern coastal areas. Showers will remain a feature through the weekend and into next week, some of it persistent depending on the moisture profile and whether we see a trough linger over the region. Another upper disturbance may feed into moisture over NSW and this could see rainfall increase for southern and southeast areas later next week into the following weekend. Some of that moisture may extend inland once again bringing up the chance of rainfall for areas hit hard in recent weeks.

Thunderstorm Forecast Thursday

Thunderstorms are likely to continue from overnight and into Thursday along a trough and weakening upper low that is traversing the inland. Heavy rainfall leading to flash flooding the main issues at this time given the moisture profile across the state.

Flash Flood Risk Thursday

Flash flooding remains a very high risk for the eastern areas south of about Mackay with the trough and upper low moving into the southeast inland. Some dangerous flash flooding cannot be ruled out with thunderstorms in the dark and purple zones. Thunderstorms over the inland will also produce flash flooding. The risk here is broad at the moment but not everyone will be clobbered but be weather aware.

MEDIUM TERM - May 18th-25th 2022

Rainfall Anomalies

It appears that the rainfall signals for the east are gathering once again above the average through this period with a very high moisture content developing over the east of QLD into NSW and a trough linking into this bringing up rainfall chances once again. This may drift into VIC. Moisture through the jet stream brings up rainfall chances for the western interior. This moisture is expected to spill through the country and feed the system in the east as well with high rainfall totals likely on current guidance for inland NSW and QLD. Ag SA may sit too far south for the weather events yet again but will watch trends.

Temperature Anomalies

Temperatures in the north and east will reflect the high moisture content and remain above average overnight and during the daytime for the most part. Cooler bias continues out west under persistent cloud cover and moisture spreading through the state with areas of rainfall. The weather over northern Australia, up to 4C above normal with high humidity values is possible about the Top End and extending southwards and east into QLD and possibly northern SA and NSW.

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 weather video on the daily breakdown but we can see the event in the east winding down in the coming days. We have the strong cold front in the west tomorrow, this system weakening as it moves east into SA and then the southeast. But a stronger spread of moisture then moves into the northwest of the nation next week and may combine with a strong cold front to bring another burst of rainfall through the west and then into SA and the southeast states. Meanwhile another trough over QLD and NSW could see showers and storms return from mid next week through to the following week. In the medium term, yet another wave of low pressure and moisture may combine to bring a widespread band of rain and thunderstorms throughout the interior and west and that too could spread into the southeast. More moisture spreads through northern Australia while the south is dealing with moving rainfall events from west to east.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The moisture distribution is very much following the guidance from last week and is now starting to clear east and southeast through the nation as a cold front picks up the flow pattern aloft and kicks the deep moisture over QLD and NSW off to the east and north. The next impulse of moisture that is coming over WA tonight is moving rapidly through the nation's south but weakening as it heads over SA and into the southeast. Still some rain can be expected with that feature. The next pulse of strong moisture comes in from the northwest of the nation via the jet stream next week while in the east, onshore winds will bring in moisture via easterly winds. Once again this opens the door for more rainfall events into the medium term with a deep moisture profile. As I always say, the marriage between the moisture and low pressure is key for major rainfall and where that happens remains to be seen.

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 - widespread heavy rainfall in the short term over the eastern third could be replicated again in the medium term, but caution is advised for anything beyond about 5 days at the moment with confidence low

More coming up from 8pm 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.

13 views0 comments