A large high is now starting to move to the southeast and east of the state which is allowing for the airflow to turn into the east or northeast leading to increasing temperatures. But that airflow will be running through moist air over NSW and QLD and that moisture will spill into SA this weekend.

For now I am keeping the threat of thunderstorm activity along the eastern border of SA with the coverage likely staying in NSW and VIC through the weekend and into early next week.

The complicating factor is a developing upper trough and low pressure system through the Bight which will approach the SA region with the chance of a more widespread shower and thunderstorm outbreak emerging from mid week.

Model madness still exists, with some of the data pushing through the system over into NSW and VIC where it amplifies but other models keeping it in SA and allowing the rainfall chances to continue for a number of days.

The forecasts will change, the upper level systems are notoriously challenging to pin down ahead of time so if this is indeed the case, we are dealing with an upper low, then the volatile forecast period will certainly feature.

Lets take a look


Rainfall Next 10 Days

Rainfall is expected to be lean through the weekend and into early next week with perhaps a few rogue showers and thunderstorms on Sunday in the far east. Next week we will see an increase in the showers and thunderstorms from about Tuesday afternoon maybe Wednesday with that activity lingering into Thursday before spreading east on Friday next week. That is the idea at the time, but the weather is likely to chop and change, so stay close to the analysis. For now unsettled weather bringing light to moderate rainfall next week, with some of the better falls likely in the south but odds on favouring the eastern areas which would be welcome.

Severe Weather Risk Next Week

A low end threat of severe weather developing over the southeast and eastern areas of the state with severe thunderstorms developing mid to late next week near a deepening upper low.

DATA - Refer to the video for further information and the day to day spread of a national wrap of the weather. It puts into the context the weather to come in the short and medium term.

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

The latest synoptic shows troughing building over the eastern inland of the nation with the easterly wind regime, not as strong, but enough to feed moisture into these troughs to help trigger scattered falls for inland NSW and QLD. This may creep into the ACT and VIC on the holiday Monday. The east coast through this period looks showery, espeically for QLD and northern NSW. In the west we have another trough that will lead to scattered showers and thunderstorms tomorrow through Sunday before clearing into the east. The remains of that trough will likely merge with another trough over the Bight leading to widespread showers and thunderstorms developing from mid to late next week over portions of eastern SA and then increasing further over VIC, NSW and southern QLD. There is a chance we may see an ECL developing off the NSW coast in the medium term which I will acknowledge under these current circumstances is a moderate chance so will be watching closely. Otherwise the tropics will see increasing showers and thunderstorms with the chance of that moisture running southwards at some stage which could help to bring up rainfall chances into WA and SA which may see only light rainfall for now.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The moisture content across the nation in the past few days has been reduced thanks to southerly winds, you will feel that during tomorrow morning with the coolest start since last October for many. Humidity will increase over in the west in the upper levels and help spawn showers and thunderstorms tomorrow afternoon near a trough. The moisture in the east of QLD will be pulled west by easterly winds and rainfall chances will be coming up as the trough over inland QLD and NSW also moves west. Through the weekend and into next week, with the constant northeast flow as the high sits southeast of Australia, this area of instability will draw in more moisture and broaden the risk of rainfall. The moisture from WA will merge with the moisture over the east and as an upper system moves into this large mass of humidity, widespread rainfall and thunderstorms could emerge along with a severe weather risk. The tropics seeing deepening moisture levels as the MJO moves closer to Australia and rolls over northern states. We could see that moisture drawn south through the nation via the jet stream.

00Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for further information

00Z CMC - Rainfall Accumulation - Next 10 Days

Refer to the video for further information

00Z GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for further information

A closer look in - refer to the video for the fly around analysis across the country - this forecast will change!!!

More information coming up from 8pm EDT looking at the models and all things rainfall and there is lots to unpack there with the potential for more widespread falls in the short and medium term. But can some be shared with areas that have missed out?

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