QUICK UPDATE - MONDAY EVENING

Hello from over Mount Isa as I travel back southwards to home.

Looking at the latest data, not much change from this morning. So the key points to watch over the coming week which I will cover off in greater detail tomorrow morning.


  1. The severe weather risk over NSW is continuing for large areas with severe storms over the inland tonight progressing east with new storms to form overnight and again on Tuesday

  2. Heavy rainfall to develop for coastal NSW and nearby the ACT during Wednesday and Thursday with some locations possibly seeing over 200mm in 24hrs through the period. Significant flooding is likely to develop for some parts of SE NSW.

  3. Severe thunderstorms could erupt again this weekend for VIC and NSW into southern QLD with another trough and upper low

  4. Tropical cyclone Anika will produce severe weather potential between Wallal Downs and Karratha through to Marble Bar mid week, with rainfall extending down to about Giles.

  5. The tropics quiet and resuming normal monsoonal break activity.

CLIMATE DRIVERS TO WATCH

Southern Annular Mode

This is in a protracted period of positive phase and I have seen comments made by officials from all levels that NO ONE saw this coming. I saw it coming, not tooting my own horn, but the complacency to just rely on computer derived forecasts has been shown to be severely flawed. The SAM is set to turn positive again and it is highly likely more heavy rainfall leading to flash and riverine flooding for parts of the east is a significant risk as we move through March. So areas in eastern QLD and NSW be weather aware and come back to the forecasts daily, and that really should be for everyone signed up here. The value is taking the time for 5-10 minutes morning and night to have a look at the videos and guidance from me. I gave heaps of notice for the last event, months in advance notice in the climate outlooks and will continue to do so. Below, some of the members are hinting at a significant positive phase mid March.

RAINFALL

GFS 00Z - Rainfall Next 10 Days

Rainfall remains very much above average in the east, but this run does not see the SAM being positive just yet, with the cyclone causing some complexities with the data output, that is normal, so expect the forecast numbers to change over the coming days.

CMC 00Z - Rainfall Next 10 Days

This is probably closer to the post in terms of heavy rainfall coverage over the east and north with a significant amount of moisture to work with and the rainfall over the tropics reducing while increasing with Anika. The weather over the southeast and east has the potential to produce significant flooding problems once again. Dry for the interior with ridging and that will extend into SA, but watch the system later this week in southern Ag areas of SA. Rainfall easing for inland QLD too.

Euro 00Z - Rainfall Next 10 Days

The Euro still has elevated rainfall for the east but now we see it focus on and to the south of about the Hunter and coastal ranges into Gippsland with nasty storm mess further west into the weekend. Also you can pick Anika over the west, the monsoonal break weather over the north, the upper ridge over Central Australia and another over the Southern Indian Ocean ridging over the SWLD.

GFS 00Z - Rainfall Next 2 Weeks

As mentioned above, the latest GFS doesn’t quite see the rainfall potential under the positive SAM so if the signals are for the positive SAM to strengthen in the medium term, we could have more flood issues to deal with so will be watching closely.

THE RANGE OF RAINFALL POSSIBILITY

I don’t show this product often because it is more useful for me to curate the forecast, but check out the rainfall spread on this plot off the CMC for Canberra. You always follow the mean of the data which is about 4 inches or 100mm for the period, but some of the outliers have 20mm and some of the outliers have 400mm! So that suggests to me we have more volatile weather to deal with over the east coast and the inland regions.

I will have more tomorrow but for now that is the wrap of the latest weather details