BROADER MODELLING AND RAINFALL CHANCES - ANY MORE CLEARER ON WHO GETS WHAT?

The forecasting as mentioned would be atrocious and confidence very low as a result and we are seeing that play out now, rather than talking about it as a theory. This is likely to frustrate many of you through the nation who are needing a drop or knowing how to plan for the sowing/planting season as we move into April.


These shoulder seasons can be very fickle (like Spring) with rainfall events appearing on the charts one moment, to disintegrating the next and disappearing only to be found elsewhere, which was forecast to be dry. That is the joys of forecasting and the joys of understanding the complexity of weather. It is more than looking at the charts, and that is why you are here.


So let us get straight into it.


ENSEMBLE DATA

These broader data sets are far more beneficial to use in the longer term for those looking for guidance as to where the pattern is taking the rainfall and subsequent weather systems. They are not fool proof, but offer a lower resolution look at who is in the higher chance of receiving measurable rainfall vs those who are not. That is to put it simply. The idea is still the same, rainfall to be found on the periphery of an upper high planted over the central and southern parts of the nation and a surface high lingering over the Southeast Indian Ocean and spreading through the Bight. Lower air pressure is clearly found off the west, north and along the east coast through much of this period and in combination with the favourable wind patterns, rainfall will be more of a feature in these areas.


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

The GFS has heavier rainfall for the west, east and north than the other models tonight though the Euro has come on board with the idea of increasing rainfall for the north and east, not so much the west. The rainfall spread out at this stage over the coming fortnight but there could be some heavier falls in there that exceed what is shown, more likely over the north and east. The tropical system not as amplified as the other models.

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

The CMC is showing the least out of the three tonight which suggests high degree of uncertainty. The model struggles with Charlotte in the short term and the secondary tropical feature out to sea. Also struggles with the other tropical low north of the NT. The east coast wet, but not as wet as the other models, suggesting a lower impact from the SAM. Elsewhere dry.

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

Has been most consistent in the approach to the model madness so far this week, has lighter falls out west with the remains of Charlotte but brings more rainfall in through the medium term via the Indian Ocean in the wake of Charlotte. She will act to pull down that moist air via the jet stream. It is possible that rainfall numbers could increase for SA and VIC towards the end of the period. Enhanced late season rainfall over the north thanks to the tropical feature appears on all but 3 of the 51 members tonight north of the NT so strong signals there and the east coast getting wetter with a strong pulse of northeast to easterly winds next week into early April atop the slow moving Tasman High This places much of the southeast in direr air for now.

LONG TERM

The longer term models as outlined today are very expressive when it comes to a wet April for much of the nation so while it is frustrating now, in about 6 weeks time, some locations again will be begging the clouds to stay away. Things can turn quickly so keep it here most days and you will find the information you are after.


CFS - Rainfall Next 6 Weeks

Wet weather being spread around the nation, find out more here from today's climate outlook

More coming up from 8am EDT on Wednesday