RAINFALL TO BECOME HEAVY OVER PARTS OF VICTORIA.

A cloudy and breezy start through Victoria today with areas rainfall, mainly light falls, throughout the state. Though that rainfall is going to increase in intensity as it approaches the northeast highlands with the cloud band running up topography and the northwest winds also enhancing rainfall rates along the northern slopes.


That same wind profile means that those areas on the lee side/southern side of the divide will be drier with pockets of rain shadow developing.


Satellite Imagery

The rain band is broken, but there are clumps of moderate rainfall passing through the state today with the best of it falling on and north of the divide today. Note the cloud approaching the southwest, that is one of many shortwave troughs expected to bring rounds of showers and thunderstorms. These troughs will become more frequent later today into Thursday and Friday as the soup bowl of low pressure south of the nation moves through to the east.

Radar

This shows a great example of the impact topography has on the rainfall spreading through the southeast. For those along the coast of NSW, they will see not much rainfall, a lot of cloud due to the Dividing Range, this week.

Modelling continues to support the best of the rainfall for the state, especially on and south of the divide, coming in from later today through to about Sunday morning, when the winds turn into the west and then southwest.


A moist airmass is embedded within the northwest to westerly flow ahead of the troughs so the showery weather could be quite productive ahead of the southwest shift.


A band of rainfall is likely to develop on the front Thursday for southern and mountain Victoria with moderate falls likely.


Showery weather to follow the cold front into Saturday will be heaviest about East Central and West Gippsland where up to 20-50mm could fall from that phase of the event as well.


Conditions will begin to ease by Sunday.


However the models diverge next week which makes it tricky to forecast the medium term.


12z Euro - Surface Pressure Pattern and Rainfall - Valid Wednesday 14th of July 2021.

Good agreement in the westerly wind belt dominating this week with good rainfall for large parts of Victoria. But then the models diverge. Euro dries out the state by Sunday afternoon with a high pushing through, the flow shifting into the west with showers contracting to the southwest. But then a low emerges out of WA with deep moisture developing offshore. This is expected to bring follow up rainfall this time next week with moderate falls returning state wide, possibly heavy over the northeast. Then more rainfall could develop following that first system to take us out to the end of the month. I am siding with this solution.

12z GFS - Surface Pressure Pattern and Rainfall - Valid Wednesday 14th of July 2021.

Good agreement in the rainfall until about Saturday. GFS goes off on it's own bringing through an upper trough with further showers developing early next week, but leaving the door open for more frontal weather to surge northeast from the southern ocean with showery windy cold weather to continue for a good portion of the coming 2 weeks. This would move the moisture from WA out to the north and keep the bulk of it dammed over WA so the inland rainfall would be off the table. But this is a very wet look for coastal areas on and south of the divide and the northeast ranges. This is an outlier.

Rainfall for the coming 10 days - Valid Wednesday 14th of July 2021.

A productive 4-6 days of rainfall for the southeast with Victoria's southern and mountain areas to pick up the bulk of the rainfall during the coming 5 days. The rainfall could be heavy at times through east Central and West Gippsland with the showery stream in the southwesterly winds combining with cold air to produce the heavy falls. Then the rainfall begins to ease later this weekend before the high shifts the winds back into the west.

Rainfall for the coming 10 days - Valid Wednesday 14th of July 2021.

Rain is falling in many areas this morning and these totals will begin to chop and change as rain falls and then rainfall next week continues to move into the 10 day window. So this chart will change. However the signal is largely unchanged for the coming 10 days especially for the 5 day period. The rainfall will return to southern areas from Thursday onwards with heavy falls developing.

Another look at the weather moving forward for Victoria this afternoon but I will have a two week forecast which will break down the modelling for the follow up rainfall potential.

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