ANOTHER GAZE AT THE MEDIUM TERM - TO SEE WHAT THE TRENDS ARE FOR THE END OF JULY/INTO AUGUST

The modelling is quite frankly of low confidence at the moment as we track into the weekend and next week, but what about beyond the period of uncertainty? Are we still tracking to see the moisture increase via the Indian Ocean and the SAM tend more negative, leading to wetter weather developing over larger portions of the south?


Overall, the idea is still the same for a more mobile weather pattern to develop and now that we are seeing the SAM tending more negative from next week could project wetter weather than what modelling is suggesting and that could extend into the end of the month and into early August as the phase peaks and resolves.


WEATHER VIDEO - MEDIUM TERM GUIDANCE - ISSUED 1030AM EST

FORECAST

Moisture Watch Next Week

Moisture is forecast to stream through the jet stream and into the frontal passages as we track through next week, the relationship between the moisture and frontal weather will determine the rainfall spread. In the east, a parcel of moisture will move in from the Coral Sea, but it is likely that the deeper moisture will swing offshore and impact the open waters of the Tasman and into NZ.

Moisture Watch Following Week

Moisture values are forecast to remain well above normal throughout the Coral Sea in response to the very high SSTs throughout areas south of PNG and towards Noumea. The moisture may clip the eastern parts of QLD and could be lifted into showers but the flow pattern keeping the most active areas of rainfall off to the east. Out west, a series of cold fronts could tap into the moisture streaming in from the Indian Ocean and leading to elevated rainfall. The SAM tending negative will see frontal weather shifting northwards.

Rainfall Anomalies Next Week

A trend towards above average rainfall chances throughout the southwest and southeast of the country but this is a marginal risk with the signals coming together to produce higher rainfall for southeast and southwest of the nation. It will come down to the moisture syncing with the frontal boundaries as they move through from west to east.

Rainfall Anomalies Following Week

That pattern of higher rainfall chances continuing over the southwest and south and southeast of the nation with the frontal weather standing up quite tall with the negative SAM. Moisture streaming through the jet stream and linking into cold fronts seems to be the area of interest when it comes to above average rainfall developing.

Temperature Anomalies Next Week

Warmer signals continuing to grow across the nation next week as we see those elevated temperatures over parts of WA being drawn through central Australia and into the southeast ahead of frontal weather. It is now looking more likely that the flow pattern is more zonal and this will now see that warmer air come into the southeast and eastern inland ahead of stronger cold fronts and rainfall later in this period. Cool bias continues over parts of northeast Australia.

Temperature Anomalies Following Week

The warmer bias continues over the northern parts of the nation with the cooler bias more likely over the south and southwest, with the temperature gradient expected to tighten. If this process continues to strengthen, then we will likely see more rainfall than what future guidance suggests across southern Australia.

DATA

18Z GFS Surface Pressure Pattern and Rainfall Distribution - Next 16 Days

I have more details in the video on this and context with relating to the other modelling.

18z GFS Precipitable Water Anomalies - Next 16 Days

The moisture is now starting to reflect more seasonal expectations nationally, but as we move through the outlook period the moisture content is forecast to increase from the northwest and west of the country as the door is open with the blocking pattern from the past few weeks now resolving. More in the video.

12z GFS Rainfall Accumulation - Next 16 days

Refer to the video for further information and context on this.

12z CMC Rainfall Accumulation - Next 15 days

Refer to the video for further information and context on this.

12z Euro Rainfall Accumulation - Next 15 days

Refer to the video for further information and context on this.


More coming up in the state-based forecasts this evening.