Good agreement in modelling for rainfall to become rather widespread in the coming days over the southwest of the nation, with multiple fronts to bring extensive rainfall Sunday to the west and southwest with follow up fronts in an unstable westerly wind belt to also bring about further moderate rainfall.

The moisture sitting off the northwest over the Indian Ocean is also rather encouraging with plumes of tropical convection sitting further south of warmer than average waters.

Satellite Imagery - note the moisture sitting off the northwest of Australia and our next front rotating over the open waters, surging north and expected to be near the WA coast by Sunday.

The wet weather is looking strong, in fact the pattern looks well and truly entrenched from Sunday for about 7-10 days through to mid July at this time.

Euro 00z run - Surface Pressure Pattern for the coming 10 days - Valid Thursday 1st of July 2021.

The first front coming in on Sunday looks to be a whopper with extensive areas of rain, thunderstorms and squally winds. Heavy falls are possible with this feature as it comes ashore with some areas exceeding 40mm with the system, possibly higher, especially on and west of the Scarp and through to the Capes and around the bend to Albany. Then as you can see a front every 24-36hrs could bring individually 10-25mm each time as they roll through. Inland areas 10-20mm with the first system and 5-10mm possible with each front that follows that during the outlook period.

GFS 00z run - Precipitable Water Values for the coming 16 days - Valid Thursday 1st of July 2021.

This is an impressive set up for the region with lots of moisture as you could see above on the satellite imagery sitting and waiting to be drawn south into the westerly wind belt, increasing rainfall chances for each front as it passes through the region. Thunderstorms and squally winds may also add severe weather threats to the region as well. The wind profile as you can see from the surface wind barbs, racing along!

Rainfall for the coming 10 days - Valid Thursday 1st of July 2021.

Rainfall extensive and daily from Sunday, with many fronts to pass through this region over the course of the next 10 days. Some modelling is more aggressive on rainfall amounts and this will chop and change as each of the fronts get into Australia upper air network to be then tracked in real time. This will help modelling with rainfall numbers and weather impacts.

It is the peak of the wet season for the region so this is climatologically expected. So there is nothing really to add to this forecast other than enjoy the dry few days as it could be a while before we string dry weather along the west coast from Sunday.

Need more weather information? Let me know - karllijnders@weathermatters.org where I do everything by hand, interpret the data and draw my own charts.

16 views0 comments