MODEL WRAP AND RAINFALL POTENTIAL

The models are diverging in the medium term, to be expected, with the inland trough this weekend the major rainfall event on the board, seeing as the Thursday system has been scaled way back at this stage for southeast areas.


It looks like the west will turn dry and stable under high pressure while the northern and eastern inland looks set to see the wettest weather in the coming 7-10 days.


The placement however of this system as you can see below is very challenging to forecast


SHORT TERM

The models generally agree on a fairly benign 5 day period with the system expected on Thursday, now not expected to project as far north resulting in lighter falls for the mainland and moderate falls for TAS. The weather then turns over inland areas from the weekend and this is where models diverge. The UKMET sees that moisture coming in from the north and produces widespread rainfall that flares off over SA and then onwards into the eastern inland after this period. The west of far east looks largely dry for now.

UKMET - Rainfall Next 7 Days - LOW CHANCE.

MEDIUM TERM

All models see the moisture and initiate the system, but the difficulty models have is how they handle the upper air flow pattern which you can see determines where the moisture is projected through the nation and where the potential rainfall goes. Each model handles it differently and I am assigning the chance values next to each global agency. There is little consistency to work with in the medium term so the forecast remains low confidence overall, but some solutions are more likely than others. Remember the flow pattern from this morning, now the models are completely split apart. We need to models to be more like below to see high confidence rainfall forecasts and temperature forecasts into next week.

ICON - Rainfall Next 8 Days - LOW CHANCE for the inland, MODEARTE CHANCE for the southeast.

CMC - Rainfall Next 10 Days - MODERATE CHANCE for the southeast - LOW CHANCE for inland areas.

EURO - Rainfall Next 10 Days - MODERATE CHANCE ALL LOCATIONS

ACCESS - Rainfall Next 10 Days - HIGH CHANCE southeast - LOW CHANCE elsewhere.

KMA - Rainfall Next 12 Days - VERY LOW CHANCE

GFS - Rainfall Next 16 Days - MODERATE CHANCE.

ENSEMBLE DATA

The longer term ensemble data with the broader member sets paint the picture and you can see that rainfall bias for the east and southeast of the nation. The wild card during this period is definitely the inland system and the question unfortunately still remains, where does the moisture go and how strong is the inland system that spawns rainfall for the central and eastern inland as all models have this occurring. CMC is the wettest by a long shot over 15 days.


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

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

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

Remember that we are now on daylight savings time for the east so forecasts will be up to an hour later than normal throughout the day as data sets from international agencies. More coming up from 7am.