HEAT ENGINE TO COME ALIVE - AND FUEL THE NEXT WAVE OF RAINFALL ACROSS THE NATION AND SEVERE WEATHER.

While we are seeing more "garden variety" frontal weather and showery periods across the nation, to the north of this wave of weather we are seeing temperatures on the climb and expected to remain above normal for the foreseeable future, adding the much-needed thermodynamics, the higher temperature gradient required for not only more dynamic weather but the formation of rain bands over the inland where the jet stream sets up.


I have covered off at nauseum the moisture content spreading through the jet stream into the nation's central eastern inland and the importance of low pressure aligned with this moisture as well as the thermal gradient and how this is key to rainfall increasing from one location to another.


But it is complex, and the modelling will struggle to find consistency from one run to the other, hence I talk in trends.


Now the trend we are looking at here this morning and what will be covered off on the videos daily through this week is the temperatures. How warm do conditions get and how long does it last before we see the cloud and rainfall break out?


Temperature Anomalies - August 2nd-9th 2022

You can see on the left-hand side the cooler bias continues on the CMC and that model generally runs cold, but even here, the model is flipping into line with the GFS and Euro which support that warmup phase through this week and strengthening that bias into the first week of August. The heat engine is important to being alive early under these climate conditions to be able to track the instability and moisture spread across the country and where the most vigorous cloud bands are set to form.


CMC GFS EURO

LONGER RANGE - THE WARMER AIR THEN IS REPLACED BY COOLER BIAS

The longer-range models also support the outbreak of cloud cover across the country, the increasing rainfall signals across the country and as that develops, a cooler bias then resumes for the second half of August. Now this cycle is something you see in September/October, which suggests to me that we will look at above average temperatures featuring following large bursts of rainfall, then following larger bursts of warmth/heat, rainfall and cooler weather develops. The frequency between the two then increases as we move into the warmer months, creating the volatile weather conditions that are famous for Spring in Australia. But I just want to show you this broad animation of that scenario playing out in the medium to longer range.

And here is the rainfall spread from the modelling below in the longer range and this supports the above idea - the warmer it gets, the more moisture is able to be held in the atmosphere then we see more aggressive weather systems form as the colder air surges north and the warmer and moist air surges south. Bang, you get rainfall. No need to say more than that. Who get's what then becomes the issue.

And here is the CFS outlook for the next 6 weeks following the Euro above. The warmer as we go through the remainder of Winter will mean the wetter we get for the remainder of Winter.

UPPER AIR TEMPERATURES - IMPACTED BY LOW PRESSURE

Finally, as we move into August, we do see many areas experiencing above average temperatures throughout all layers of the atmosphere but as we see the unstable weather returns, more zonal flow forming over southern Australia and rainfall increasing once again, temperature come down and it is quite conceivable below average temperatures will resume for many areas away from the tropical north.


Temperatures at the 1.5km above the surface - can see the warmer air spreading through the nation. August 1st-8th 2022

End of the month the temperatures are more representative of a fast flow pattern over southern Australia with rainfall spreading from west to east and the warmer air continuing to build over northern Australia with higher humidity.

I will have more forecast information on the medium term through the evening weather videos and, on the Facebook Page, as well.