MODELS AND ALL THINGS RAINFALL

The weather models have been continuing to shift around during the past 24 hours but we are starting to see better rainfall signals for the secondary system this time next week, but where the models are struggling, is with the high amplitude pattern through the southern parts of the nation later this week. Where the low goes, so does the heavy rainfall, and parts of southwest Victoria and southeast SA could see a good dumping, if the low passes overhead.


Otherwise the tropics are active, the storms return to the east and northeast and severe storms may be on the cards for multiple states during this period.


The west....staying cooler with showery weather from time to time while the tropical north bakes.


These are the areas under the current guide on my parameters for flash flood and riverine flood issues over the coming 6 weeks on more than one occasion. This is based off the longer term data and current soil moisture profiles through the nation. More on this throughout tomorrow or Thursday.



Lets take a look


SHORT TERM

The short term has been very difficult to pin down across all agencies, the precise location of a low skirting the southeast coastal areas of SA into western VIC is making it very hard to predict rainfall for the southeast states. In the warmer sector we know we will see showers and thunderstorms with uneven rainfall distribution and that will continue over the tropics with the chance of heavy falls for the NT and QLD. Finally out west, the showery weather will begin to decrease as we track high pressure through, that high also clearing out the southeast over the weekend into early next week when the pattern resets once again.


UKMET - Rainfall Next 7 Days - MODERATE CHANCE

MEDIUM TERM

The secondary system emerges out of the tropical airmass and low pressure trough running along the west coast of WA which brings the chance of showers and thunderstorms over eastern WA then into SA mid next week. There is evidence this secondary system will likely be cradled by high pressure to the south which we see a multi day rainfall event for SA, VIC and NSW with thunderstorms and humid weather about. The west under ridging looks relatively dry with easterly winds dominating. The tropics active with heavy falls about and that will move south into the central interior, thanks to the trough moving into the southeast inland of the nation in the 8-12 day range.


ICON - Rainfall Next 8 Days - VERY LOW CHANCE

CMC - Rainfall Next 10 Days - LOW CHANCE

EURO - Rainfall Next 10 Days - MODERATE CHANCE

ACCESS - Rainfall Next 10 Days - LOW CHANCE

KMA - Rainfall Next 12 Days - LOW CHANCE

GFS - Rainfall Next 16 Days - LOW CHANCE

ENSEMBLE DATA

This data is still the most useful, they are all starting to come into reasonable agreement about the spread and intensity of rainfall through southeast, central, northern and eastern parts of the nation with a series of troughs and lows moving through deep moisture, triggering more rain and thunderstorms. While the falls are likely to be uneven in distribution, many areas are looking at above average rainfall chances through this period.


GFS - Rainfall Next 16 Days (median of 35 members) - LOW CHANCE

CMC - Rainfall Next 15 Days (median of 30 members) - HIGH CHANCE

EURO - Rainfall Next 15 Days (median of 51 members) - MODERATE CHANCE


LONG TERM

The wet run to December continues.


CFS - Rainfall Next 6 Weeks - MODERATE CHANCE

The control member highlights the very wet signal for the east.

This the ensemble member through to December 10 - that is wet!

More coming up tomorrow from 7am EDT.