Let's look at the weather outlook for the King's Birthday Long Weekend and beyond.
We have a significant rain and snow system about to head across southeastern Australia.
The ingredients are the full trifecta – low pressure, a feed of tropical moisture, and proper cold air – all working together to bring rain to drought affected areas and snow to the alps.
The slowness of this weather system is one of the key ingredients. A cold front passes through first, but that’s just the opening act. A low becomes cut off from the fast-moving westerlies to our south, so that it wanders through, taking its time.
This begins on Friday and lasts through the long weekend, and that slow movement means that it can deliver bigger totals.
Anything yellow on this map is likely to see at least 25mm. Anything orange is over 50mm. Brown over 75mm.
Potential rainfall over the next week
These bigger falls are near the coast, and across the ranges, as they are closest to the low pressure, or helped by elevation.
The rainfalls peter out as you head inland over the ranges, as the low is taking a track further to the south.
Once the low moves away early next week there is a weak system to follow mid to late in the week, that brings just a bit more rain.
In the longer term, the modelling doesn’t scream anything significant in the southeast as a follow up, in week 2 (beginning the June 16) or beyond at this stage. Week 2 is wishy-washy, and the monthly outlooks are too. These monthly outlooks show increased odds for rain further north, but struggle to let it reach the south.
BoM's latest projection for July to September
The Indian Ocean is likely to move into a Negative phase of the Indian Ocean Dipole from July, lasting into spring. This will actively encourage feeds of moisture to move into Australia from the Indian Ocean.
The Indian Ocean Dipole observations and forecast
That’s the first part of the rainfall equation. You also need instability to turn that into wet weather.
The instability part is always the hard one to foresee, and the current modelling from BoM doesn’t show a strong signal for the lows, fronts and troughs needed to make the most of that moisture.
Let’s see what their modelling suggests next week.
The long weekend’s significant weather system has all the right ingredients for a proper dump of snow.
We have slow moving instability, plenty of moisture, and plenty of cold air.
This weather system guarantees at least a good start to the season. Hopefully there will be a few more as it progresses.
Potential snowfall over the next three, seven and 10 days.
For an in depth explanation on all of the above, don't miss my video update - and apologies for the car noise! I am on my way to Mt Buller to broadcast 7NEWS tonight :)
