MEDIUM TERM FORECAST - THE RAINFALL SET TO INCREASE AS EXPECTED FOR THE REMAINDER OF THE MONTH.

The signals for more heavy rainfall in the short term for flood impacted areas of the southeast and east is expected to be the focus, most elsewhere throughout the nation, seasonal weather is expected. Do not feel like you are being left out, your time will come!


The east is expected to become more unstable through the medium term. The issue from next week is do we see a secondary low pressure system form over the central and eastern interior of the nation that sparks more heavy rainfall? Some models say yes, some say no.


This is normal for November as we see the nation begin to warm further and more moisture surges south and west into the nation from the tropical easterly winds and the monsoonal flow up to the north. We are seeing elements of this beginning to appear at the end of the month and into December.


So therefore, this will cause havoc in the next few weeks of modelling beyond about 7 days so I just want to make you aware of that.


Lets take a look at the latest

FORECAST

Moisture Watch This Week - November 17 - 23 2021

No change to the assignment of moisture across the nation and into the weekend before it moves through next week, with yet another moisture surge moves out of the north and northwest again into the central interior this time next week.

Moisture Watch Next Week - November 24 - December 2 2021

Moisture deepens across the northern and eastern parts of the nation and I will be watching the Coral Sea closely, with a strong tropical wave moving west towards the QLD coast which may bring an enhanced burst of moisture spreading over northern and eastern Australia. Over in the west, moisture may also surge south from Indonesia into the jet stream and impact parts of central and southern Australia to kick off December, this moisture running into existing moisture over the eastern states.

Rainfall This Week - November 17 - 23 2021

Rainfall heavy at times during this week with the bulk of it to fall from Friday through Monday with a deepening low pressure system. The tropics are also expected to turn more active and this moisture spreading south into a new trough emerging next week so the coverage of wet weather for northern and central parts of the nation increasing as well. This will then creep further south by this time next week.

Rainfall Next Week - November 24 - December 2 2021

A low pressure trough and low pressure system will likely move east through QLD and NSW taking tropical moisture with it and lifting rainfall chances once again for the saturated eastern inland. This rainfall may bypass Ag SA and most of VIC where a cold front and weak trough moves through with light showers. The west stays dry under a ridge and the tropical weather becomes more active. As mentioned, watching the tropical wave out in the Coral Sea moving west and the moisture surging out of Indonesia bringing up rainfall chances for northern and eastern Australia.

Rainfall Anomalies - November 17 - December 2 2021

Rainfall anomalies continue to run above average for much of the nation, especially the southeast inland extending back north and northwest to the tropics as the season once again turns wet. The wet weather will likely drop another 1-2 months worth of rainfall for eastern inland NSW and northeast VIC.

Temperature Anomalies This Week - November 17 - 23 2021

The cooler bias continues this week for much of the nation, but the west may see an increase in temperatures as a high begins to move east later in the weekend into next week and winds veer into the east bringing that warmer air west. The east under thick cloud and onshore winds will remain cooler than normal. The heat levels over the north will reduce with the weather turning more humid as we go along and the rainfall increasing.

Temperature Anomalies Next Week - November 24 - December 2 2021

The cooler bias continues for the east with widespread cloud cover developing with a secondary low pressure system moving over the eastern inland. The onshore winds via easterly winds will also keep temperatures down. The northern tropics also near seasonal but some pockets that avoid rainfall will see warmer weather. The west could see quite hot weather if a persistent ridge remains stagnant south of the state.

DATA - Refer to video for more details


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

The pressure pattern is volatile on the GFS and will continue to remain this way with the tropical weather starting to crank up. When there is increased tropical activity, this model does not handle that well, especially early on in the season so expect the forecast confidence to remain low until we see the tropical weather evolve in real time.

18z GFS Precipitable Water Anomalies - Next 16 Days

Note the moisture surging west through the Coral Sea and over the tropical north towards the end of the month. This may be drawn south into troughs over QLD and NSW with enhanced rainfall chances. Note the moisture surging through the Indian Ocean southeast into the interior and the southern states as well. This moisture is likely to lead to higher rainfall totals than what this model is showing.

18z GFS Precipitable Water Values - Next 16 Days

The surge of moisture from the northwest through southeast early on in the period is significant in any year but on top of what we have experienced so far this Spring it is going to mean more rainfall is on the way for southern and eastern areas but now we also need to watch the tropical waves moving through the tropical easterly winds over the course of the latter part of this period, bringing increased rainfall chances to eastern QLD and NSW then through the NT.

18z GFS Rainfall Accumulation - Next 16 days

Refer to the video for more

12z CMC Rainfall Accumulation - Next 15 days

Refer to the video for more

I am leaning more with this solution.

12z Euro Rainfall Accumulation - Next 15 days

Refer to the video for more

More details to come in your state based update this evening.