SA - BECOMING UNSETTLED TUESDAY AND POTENTIALLY HEAVY RAINFALL FOR EASTERN SA ON WEDNESDAY

The model madness continues for the system evolving out of WA today, as that moves into SA tomorrow and then tracks eastwards. The trough will lose a little bit of punch tomorrow but reignites during Wednesday and there is the potential for a low to form along the trough.


As moisture surges through the northeast winds from NSW and QLD and moisture left over from the northwest Indian Ocean converge into this area of deepening low pressure, the rainfall coverage increases. Heavy falls are possible up around the Mid North, Flinders and through the Murraylands and Riverlands potentially with a centre of low pressure passing southeast.


The rainfall gradient is quite tight so expect to see areas spared from the very wet weather while say 50km away, some areas copping a months worth of rainfall. The southern Ag areas likely to remain under light rainfall at this time but keep watching as all the low needs to do is to move 50km further south and this changes everything.


Lets take a look

FORECAST

Rainfall Next 10 Days

Rainfall is expected to return to the far west tonight, there is a large cloud band with isolated showers and thunderstorms ahead of the thick cloud cover. The moisture out of WA will increase over SA tomorrow and merge with moisture over the east and this is where we will see widespread showers and thunderstorms emerge along this trough. The trough is likely to deepen into a low pressure system somewhere north of Adelaide later Wednesday into Thursday with areas of heavy rainfall and thunderstorms possible. The low moves southeast into VIC Thursday afternoon and a drier and gusty southeasterly flow follows and from Friday most of the state should be dry into next week. Another change develops from the southwest next week which could produce a few more showers in the south and southeast.

Riverine Flood Risk - Wednesday through Friday for SA.

I am pulling the low risk over the far east bordering VIC and NSW where the low is anticipated to amplify. Recent moderate rainfall has kept the region relatively wet over the inland so this may see flooding redevelop through parts of the Riverlands and Murraylands back to the Mid North and Flinders, under the developing low on Thursday.

Thunderstorm Forecast Tuesday

Thunderstorms are possible in the far west tonight. They will return into Tuesday afternoon through central areas in particular and then into eastern districts very late in the day or at night with some of those potentially gusty with heavy rainfall but for now the air aloft is not supportive of widespread severe weather. That changes Wednesday.

DATA

00Z Euro - Surface Pressure Pattern and Rainfall Distribution - Next 10 Days

The weather is anticipated to turn unsettled as mentioned in the video from mid week over SA and then into the eastern states. Deep moisture, high levels of instability are expected to lead to widespread rainfall with scattered heavy falls, flooding and severe storm potential. The weather gradually clears from the south and west through SA and VIC from Friday and NSW from Saturday and QLD Sunday, though coastal areas in the east may remain humid with showers, but heavy falls will retreat to the tropics. Out west your weather is turning hotter and drier and this may creep into SA next week. Some potential for another rainfall event next week for the southeast or east which may deliver additional rain and thunderstorms but the confidence is low with not all models on board, however another low in that position that Euro is suggesting is placing a shiver up my spine for flood risks next week on top of what happens this week, IF it happens. The northern tropics getting more unsettled over this week with a better coverage of storms, some severe.

00Z Euro - Precipitable Water Values - Next 10 Days

No change to the guidance with a deep moisture layer in place throughout much of the north and east which begins to move east and north over the weekend, but some chance it could stall out well into next week over parts of NSW and QLD. The drier air can be found over WA and into SA then VIC from the weekend but as mentioned above, a third system with equal rainfall potential has me very concerned next week IF it verifies.

00Z Euro - Rainfall Accumulation - Next 10 Days

More on this after 9pm tonight.

A closer look in

More details to come on all things rainfall after 9pm tonight.

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