A deepening trough through eastern WA with significant moisture shifting southwards into SA is going to bring the tropics into the state with the moisture and thundery weather sticking around for a while over much of the state.

Heavy rainfall and thunderstorm activity over outback areas could bring near record rainfall to some locations during this period. The rainfall over the south and east not expected to be as heavy, but scattered thunderstorms and showers will bring back light to moderate rainfall to the Ag Areas at this stage with thunderstorms bringing the better rainfall chances as always.

The weather is warm and humid with scattered showers and thunderstorms over northern areas during the latter part of this week while the south sees a cooler southeasterly change but that moisture will come back south this time next week with another round of showers and thunderstorms.

The humidity values will create a problem for some farmers and vingerons in the east and southeast with a risk of the usual nasty fungal issues.

Lets take a look


Rainfall Next 10 days

Rainfall is expected to be more widespread over the northern and western areas of the state with the deeper moisture and trough lingering there for much of this week before the southern branch of the trough is kicked along by a cold front during mid to late week. Some of the rainfall and thunderstorm activity over northern areas could be rather heavy and highly unusual for this time of year. Southern Ag areas may dry out during the latter part of this week but the rain and storms persist over northern areas towards the NT border. That rainfall and thunderstorm activity is expected to sweep south once again from this time next week with the uneven distribution of rainfall continuing. The more widespread coverage of rainfall is expected over northern areas.

Thunderstorm Forecast Monday

Thunderstorms are expected to be active over parts of the northern and western areas of the state with a slow moving trough and high moisture levels pouring in from the Indian Ocean and NT and QLD. The rainfall could be heavy at times which may lead to flash flooding. There may also be damaging winds under thunderstorms closer to the NT border.

Flash Flooding Risk Monday

Thunderstorms may be scattered to widespread during the afternoon and evening, with some storms heavy at times around the APY Lands and through to the southwest NT with some flash flooding possible.

Damaging Winds Risk Monday

Damaging winds are likely with the stronger thunderstorms during the afternoon and evening with storms progressing northwest to southeast through the state. Winds may be strong enough to cause tree damage and thick areas of raised dust.


Euro 00z - Surface Pressure Pattern and Rainfall Distribution - Next 10 days

More details on the synoptic scale in the video at the top of the page.

GFS 00z - Precipitable Water Values - Next 16 days

The very high moisture values leads to excessive rainfall and that also impacts rainfall chances further around the nation where the upper level winds propel that moisture to.

GFS 00z - Precipitable Water Anomalies - Next 16 days

Note the moisture recycling and circulating around the nation, I talk more about this at the surface level in the video at the top of the page.

Euro 00z - Rainfall Accumulation - Next 10 days

More details in the video.

A closer look in. No skill in specifics, we now work with ranges of rainfall forecasting which I know is frustrating but that is how it rolls.

GFS 00z - Rainfall Accumulation - Next 16 days

Scattered uneven rainfall will continue, but that rainfall prognostic for the tropics into the NT and WA is record rainfall for this time of year.

CMC 00z - Rainfall Accumulation - Next 15 days

That is a wet look for the nation, even SA which is sitting in a 30-60mm range for the next 2 weeks.

CFS 00z - Rainfall Accumulation - Next 6 weeks

That wet signal continues for much of the nation into mid December

I will update more tomorrow from 7am EDT. Let the models settle and see how they look during the morning.

32 views1 comment