A CLOSER LOOK AT THE RAIN EVENT FOR THE SOUTHEAST

I have already posted about this in the southeast weather section in a broad sense but an update on rainfall timing and the latest data on what to expect.


Areas of rain are starting to increase as the front begins to move into the warmer and humid airmass over NSW. There have been scattered showers and isolated thunderstorms over the northern and central inland of NSW already this morning. But the bulk of the rainfall is yet to arrive for NSW - where the most widespread falls are expected.


Satellite Imagery for the previous 6hrs.

You can see the major rain band starting to form over inland NSW as it runs into the moisture remnant from last weeks front. The heat and cold air clashing with moisture also now increasing from the northwest and north. A thick area of rainfall developing this afternoon will be introduced by scattered showers and thunderstorms over the east.

State of Play this afternoon.

Thunderstorm Forecast


Remains unchanged from yesterday, thunderstorms likely to develop in the warmer sector this afternoon and with the dynamic forcing thanks to the cold front in the region, this will create the chance of damaging winds and heavy rainfall for parts of the GDR.

Severe weather zone for Tuesday into Wednesday with the low pressure system, for damaging winds and heavy rainfall leading to flash flooding. The catchments on the eastern side of the divide are drier so riverine flooding unlikely at this time.

Euro - Surface Pressure Pattern next 4 days

Note the rain band sweeping through the east today, it does slow down over the GDR, and will begin to tilt, as a low pressure system develops over the Illawarra coast tomorrow, that will see rain become heavy and persistent for large areas tonight and through Tuesday. Heavy rainfall leading to areas of flash flooding is possible for the east coast and about the Southern Highlands and Tablelands between Canberra and Sydney as well. The rainfall then contracts east with the surface low moving off to the east, but note the blue 540 ring over the eastern inland, this parcel of colder air needs watching as it could kick off more rainfall with moisture surging north through the east coast during Wednesday or Thursday.

Euro - Precipitable Water Anomalies next 4 days

Moisture is deeper over the eastern inland today but note it consolidates and then begins to be wrapped around a surface low, that low helping to draw in dry air through the eastern inland west of the divide, leading to drier weather developing tomorrow with a cold airmass. The rainfall then is connected to the low later tomorrow through Wednesday before that moves off, but impulses of moisture will bring rainfall to southeast NSW and Gippsland right through until Thursday. This area getting a nice drink after quite a dry spell.

Latest Rainfall for the region.


Rainfall for the coming 4 days

You can see quite a dump of rainfall is likely for the east, and your number may vary in these zones with thunderstorms in the mix, we are moving to that time of year given the convection is involved. For the east coast, this will be the heaviest rainfall for 2 months, especially south of Newcastle.

Latest data


Latest Euro Rainfall for the next 4 days

Very good agreement now on the rainfall heaviest on and east of the GDR with thunderstorms this afternoon possibly bringing heavy bursts of rainfall topping up falls higher than what is shown here west of the divide along the slopes and plains.

ICON Rainfall for the next 4 days

You can see the smear of heavy rainfall for the southeast inland of NSW with heavy falls possible about the east coast from Newcastle south to about Narooma. The rainfall will peak during Tuesday before the low moves away to the southeast, the track of heaviest rainfall offshore suggests a steady movement to the southeast of NSW mid week onwards.

CMC Rainfall for the next 6 days

Rainfall again biased for the eastern third half of NSW with big falls on the NSW coast from Newcastle southwards. The rainfall peaking during Tuesday before it eases during Wednesday with the low also steadily moving off to the southeast similar to the other global modelling, tracking the system off to the southeast from NSW.

KMA Rainfall for the next 6 days

Showers and areas of rainfall again biased to the southeast and eastern third of NSW extending into southern QLD with a few storms, with the focus of rainfall peaking during Tuesday then the focus shifts to the coast before easing Thursday.

Ukmet Rainfall for the next 5 days

Widespread rainfall similar to the other models for the coming few days with heaviest rainfall expected Tuesday. Does not quite develop the low pressure but I do suspect there will be heavier falls than what is being advertised.

Latest GFS Rainfall for the next 5 days

Widespread rainfall now extending back through southern QLD but also now starting to see a secondary wave of rainfall develop later this week over QLD in response to a stalled boundary. The wettest weather is expected this afternoon or this evening.

I will have more this afternoon.

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