MODELS AND ALL THINGS RAINFALL - THE DRIER PICTURE FOR MOST OF US LASTS INTO THE WEEKEND.

Despite the severe thunderstorms impacting parts of eastern SA, through western and southwest NSW into southwest QLD and much of western VIC, the weather is much more settled for many of us. The east coast seeing a few showers but they increase in coverage the further north you go through QLD where areas of heavy rainfall are continuing for FNQ.


Some locations in FNQ seeing beneficial rainfall in response to the trade winds combining with the trough in the region driving the heavy falls.


Over the north the routine daily storms will continue.


Waiting for the medium and longer term to see how all that moisture in the Indian Ocean interacts with what appears to be the first long wave trough peaking in northward projection west of WA. That could be an interesting feature to watch as it may be hallmarks of the Autumn Break unfolding in the medium term and on the charts.


Lets take a look


SHORT TERM

As mentioned through your state based forecasts and the national weather wraps in recent days, the wettest weather is connected to the trough over in the southeast, the heavy weather associated with the trade winds and a trough over FNQ and the tropics seeing regular showers and storms in the routine tropical airmass. Most elsewhere this week should be dry and mostly settled away from isolated showers returning to the southeast and isolated showers south of Mackay in QLD to the east coast of VIC.


UKMET - Rainfall Next 7 Days - MODERATE CHANCE

The UKmet like the ICON shows the rainfall with the storms over the southeast and eastern inland extending into SA over the coming days. Showers and thunderstorms over the north is more widespread on this model over the Kimberly but watching very closely the trough that has formed through FNQ into the Top End. We may see a tropical low form in this mass of convection. Elsewhere it should be a mostly dry week. A few showers about the east coast in onshore wind is likely with light falls.

ICON - Rainfall Next 8 Days - MODERATE CHANCE

Similar to the UKmet. Note the heavier weather over the tropics, that would be a feature to watch over the next week and the moisture well offshore the WA coast in the Indian Ocean with the MJO moving through. At this stage, no interest in the moisture being propelled through WA.

MEDIUM TERM

All eyes on the MJO rotating through the Indian Ocean and whether this feature can send moisture further south through the Basin and connect with what appears to be the first of the long wave troughs to have any impact this Autumn. It is a question of whether that LWT peaks over WA or slides away to the southeast before hitting the mainland. How much moisture gets into the feature? The MJO will likely increase rainfall chances over the northern tropics as that works closer. The SAM will likely remain at neutral values for now, but some movement to another positive phase has been emerging in the past 2-3 days but I am keeping it at neutral values. The confidence in the longer term forecast is quite poor.


CMC - Rainfall Next 10 Days - MODERATE CHANCE

Note the MJO building just offshore the WA coast with a tropical feature spreading south from Indonesia. The wet weather in the southeast and east will be connected to the current storm activity over eastern SA, western NSW, VIC and into southwest QLD. Showers about the east coast with light falls. The model does see the fast flow pattern to the south of the nation but it is out of phase with the MJO at this time so limited impact from moisture streaming out of the northwest.

EURO - Rainfall Next 10 Days - HIGH CHANCE.

The latest Euro is probably closest to the post in terms of the rainfall distribution under the current guidance from the short term climate drivers. Still watching those pockets of low pressure over the north which could emerge as wild card systems, especially if they develop northwest of the nation and moisture is sheared off to the south and east of these features via the jet stream. But for now, once we lose the rainfall over the inland of NSW, the bulk falls later this week and into the weekend.

ACCESS - Rainfall Next 10 Days - LOW CHANCE

You can see the tropical mischief increasing offshore the NT and way out in the Indian Ocean with the turn towards the WA coast being caught up in the jet stream. Note the trade winds pumping in heavy rainfall onto the FNQ coast. And once we lose the rainfall over the western parts of NSW and into eastern SA, the rest of the rainfall comes in the latter part of this week and through the medium term.

KMA - Rainfall Next 12 Days - LOW CHANCE

Also has the tropical mischief up over the NT that needs to be watched and like the ACCESS sees the tropical weather over the Indian Ocean and via trade winds over the FNQ coast and Cape York. We just need the fast flow pattern to develop over the south to pull the moisture southwards from the tropical north.

GFS - Rainfall Next 16 Days - LOW CHANCE

The GFS prints out multiple cloud bands across the nation with the MJO moisture being dragged in ahead of frontal weather south of the nation. The wet weather over the north increasing later in the period with tropical rainfall becoming more extensive in line with the MJO on the approach. The weather for the nation looks wetter than most models over the course of the next 2 weeks.


ENSEMBLE DATA

These have been divergent as well, where the GFS has been on it's own and the Euro and CMC have been in agreement about where to place the rainfall in the east. They all see the tropics turning more active, especially north of the NT and points eastwards.


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

I am leaning towards the MJO influencing the weather over the north with enhanced tropical weather but I am also supporting the rainfall increasing offshore WA and approaching the coast towards the beginning of April with northwest cloud bands developing.

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

The CMC is in good agreement with the deterministic and is showing fairly light falls for much of the nation away from the tropics. Showers may increase for the east coast during the medium term.

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

This model splits the difference between the CMC and GFS and shows rainfall increasing over the northwest, across the north and northeast. Once we lose the rainfall over the eastern inland through western NSW and eastern SA the bulk falls beyond this. Note the spill of rainfall and moisture through the northwest of the nation and into the Central interior. Showers also increasing for the east coast later in the period.

LONG TERM

I will have more on this coming up tomorrow, but certainly seeing that seasonal shift in the rainfall distribution into April. I am feeling more confident about the Autumn Break occurring in the coming 6 weeks across the country.


CFS - Rainfall Next 6 Weeks

The CFS is showing that rainfall moving through southern parts of the nation via the mid latitude westerly winds and the jet stream aloft. So we will see some shifting in the stagnant distribution of rainfall of the past few months. So areas that have missed out over the south your time is coming with some luck.

More coming up from 8am EDT on the next National Wrap and video ahead of your climate outlook for the rest of March and April.