MODELS AND RAINFALL - THE SHORT TERM OFFERS RAINFALL FOR MOST - BUT I AM STILL LOOKING TO AUGUST.

We have seen a persistence of rainfall for the east over the past week and that was well picked by these broader consensus models and larger data sets which quite frankly, should be used more in the production of products for consumption by the public, but I digress. The overall trend is to see the east dry out as the easterly wind resolve and a return to weather coming out of the west a broader northwest to westerly flow emerges.


Within that flow pattern we have cold fronts which are expected to drive showery weather in their own right. However, there are bursts of tropical moisture running through the jet stream from south of Indonesia and trying to hook into cold fronts as they are moving out of the west leading to larger bands of rainfall and rainfall events developing through the outlook period.


With that said, there is a better confidence emerging through the guidance of rainfall returning to the southern states and possibly becoming the most widespread rainfall events we have seen since the start of Winter. So, it has been a long time between drinks for Southern Australia.


Elsewhere under the guidance, the weather is looking for a lot more settled with ridging in place north of these features running through Southern Australia.


ENSEMBLE DATA

GFS - Rainfall Following 7 Days (median of 35 members) - MODERATE CHANCE.

The GFS falling into line with the other models and finally starting to show the impact of the developing IOD and the moisture extending from that climate driver and feeding the jet stream and then running into frontal weather. The east of the nation looking more seasonal for now with a drier period developing following this week's unusual rainfall once again. Moisture values may also increase over the NT and Cape York into early August.

CMC - Rainfall Following 7 Days (median of 30 members) - MODERATE CHANCE

Noting that the CMC is continuing along the idea with the GFS of the winds shifting into the west and moisture spreading through the jet stream leading to widespread rainfall developing from WA through SA and into VIC. The rainfall totals on some of the members are far more excessive than those that are not showing as much on the CMC tonight which is promising for areas that are needing rainfall. The eastern and northern areas looking at more seasonal conditions for a while.

EURO - Rainfall Following 7 Days (median of 51 members) HIGH CHANCE

The latest Euro also supportive of the moisture spreading through the west of the nation and then crossing into southern SA but still looking to have heavier impacts into VIC and NSW as well as western TAS. Showers decreasing over the east of the nation as the flow pattern shifts into the west meaning that drier air will be pulled into the eastern inland. The signs of the Indian Ocean waking up are now increasing.


LONG TERM

CFS - Rainfall Next 6 Weeks - LOW CHANCE

The control member below showing very significant moisture spreading through the nation via the jet stream leading to above average rainfall in many states.

The broader data set also supports this idea and showing some additional heavy rainfall for the east coast in the month of August. But good to see the consistency from run to run on these data sets. And now we are seeing the rainfall coming into the medium range forecasting so to an extent it is starting to verify.

MEDIUM TERM FORECAST

July 28th-August 5th, 2022

Moisture Watch

Not much change to the guidance surrounding the spread of moisture through the latter part of July and into August with all major global model agencies forecasting deeper moisture working through the westerly wind belt a top the frontal weather passing through Southern Australia. Some evidence that this could be drawn into frontal weather spreading larger bands of cloud and rainfall across the nation. In this scenario, the east and north of the nation look relatively drier with westerly winds over the south and southeast winds over the northern tropics under ridging, though humidity values are creeping up north of the nation as well.

Rainfall Anomalies

The west of the country looking a higher probability of recording above average rainfall through this period with that gradually spreading eastwards. But confidence in the strength of the frontal weather as it moves further east is the only element that is stopping me from drawing the green shading further east into SA and VIC. So seasonal rainfall expectations for now through this period can be expected. The rainfall clearing the east and dry weather over the north, resulting in seasonal weather for these areas.

Temperature Anomalies

The warmer air that is building throughout western and central Australia next week will begin to become displaced via northwest to westerly winds and filter throughout much of inland SA, into northern VIC and western NSW and QLD. Cooler bias develops over the SWLD in onshore winds and showery weather and over the northeast, still looking for below average temperatures with the onshore winds continuing.

More coming up tomorrow from 5am EST with a look at the areas to watch.