MONDAY MORNING WEATHER - WE ARE ON HIGH ALERT FOR FURTHER FLOODING IN THE EAST. QUIET ELSEWHERE.

The weather is turning much more settled for about 85% of the country today, as dry air is propelled north, a ridge is slowly moving east through the south of the nation and thus leading to clearer skies and seasonal temperatures.


But where we don't want severe weather and rainfall, we have got a lot more of it to come and it is ongoing from last night.


Severe thunderstorms overnight lashed the SE and E of QLD and that is expected to return again today with further heavy rainfall possible with thunderstorms.


The most widespread severe weather is likely to develop between about Taree and Wollongong over the course of the next 24-36hrs with some locations expecting to see upwards of 300mm. A deep upper low is set to track east and then southeast and pop off the east coast, and a surface low is expected to form near the Hunter Coast this evening and deepen overnight.


The speed as to which this system moves away from the coast will determine the longevity and intensity of the severe weather event and that remains to be seen. Some areas could see another round of devastating major flooding but some models are not as amplified in this idea so we will have to watch closely. What happened one week ago was that the modelling was not as aggressive on the rainfall front for the east and we know HOW that panned out. So it is not an open and shut case.


WA and through SA into the southern NT, western QLD and northwest NSW, fine and warm to hot. Milder back through the southern coastal areas and districts of WA and into SA and western VIC. The easterly winds drying out and more stable nearer the ridge.


Some suggestion that NSW will get a break from the wild weather from mid week and the nation as a whole away from eastern QLD looking relatively settled and calm.


Over the weekend the moisture will build over the north and east and the cycle of more rain and humid weather to come for mid to late month, you guessed it over the eastern areas looks a firm possibility. There are also signals that with the MJO deepening northwest of Australia, moisture could also start to be drawn into the jet stream, and how about we see whether we can get more rainfall chances on the board for WA and into SA through the medium term.


Tropics, routine for now but falls could be shifting to above average values into the medium term, perhaps the last monsoonal burst this far south of the equator for the wet season


Lets take a look

FORECAST

Rainfall Forecast Next 10 Days

We are seeing the moisture begin to shift out of the southeast and south of the nation with that drier air surging north into an upper low wafting over inland NSW today. As a surface low develops offshore NSW, this will help to drag that drier air into southern and western QLD for a period. But the dry air does not last long, it is likely to be overrun by the weekend as easterly winds return for the east of QLD and into northern NSW, this moisture then spreading south next week into interior NSW and VIC. At this time, the tropics are seeing seasonal rainfall expectations but these too could increase as the MJO gets closer to northwest Australia during the period. The major rainfall expected in the short term is the east coast of NSW with significant rain likely from this afternoon through Wednesday morning with some areas again likely to see around 300mm overall, possibly more. Pinning who gets the worst of it is very tricky and careful monitoring of the upper low today is crucial and refining of this forecast will take place throughout the day for NSW. SE QLD through the Wide Bay and Central Coast and adjacent inland may see storms most days this week, heaviest over the Central areas adjacent to the coast. In the west and through the central interior, through much of SA, mainly dry for now but I may start drawing in some rainfall for interior parts of WA for next week with the trough over the west tapping into moisture from the Indian Ocean.

Thunderstorm Forecast Monday

Thunderstorms will likely contract further north and east through NSW and over eastern QLD where an upper trough remains. The storms may be severe over the east of QLD and northeast NSW. The southeast and eastern inland looking drier with more stable air near ridging. The north of the nation, the routine showers and storms continuing, these may extend further down the west and northwest coast.

Thunderstorm Forecast Tuesday

Thunderstorms are forecast to contract further north and east through NE NSW and into eastern QLD as the boundary bringing the severe weather risks this weekend moves further north through nation. Thunderstorms could increase in coverage during the afternoon and evening for the tropics and spread down the immediate west coast of WA with gusty winds possible about the northwest. Stable dry air for the remainder of the nation.

Thunderstorm Forecast Wednesday

Thunderstorms continue to contract further northeast through NSW into eastern QLD. Some severe weather is possible about the Central and Southeast Inland of QLD with heavy rainfall the main concern. The routine showers and storms over the tropics are set to continue with a broad coverage over the Top End. Ridging over much of the nation keeping things dry and stable.

DRIVERS TO WATCH


SOUTHERN ANNULAR MODE - SOUTHERN OCEAN

The MJO is peaking over the course of the next 2 days before remaining for the rest of this week, that phase likely to play out later this week into the weekend before easing next week. Mid month, the SAM looks to be around neutral, but there are more members tending back positive and I suspect we will see another round of positive phase coming. But the increased in variability in the driver is a signal that the La Nina is beginning to wane and that will mean a gradual reduction in rainfall and severe weather as we move into April and then transition out of the humid period into a traditional drier and cooler Autumn period into May for areas away from the southern and eastern parts of the nation. The guidance beyond about 7 days looks quite poor. Note, that since last November we have see the SAM turn negative just 1 time! Remarkable, so it would be a sign that the La Nina phase is starting to ease in the Pacific, if this does occur in about a week. Will watch.

MJO - TROPICS

This will be the driver to watch. I spoke about this on Friday that the MJO may redevelop northwest of the nation and swing through the Australian Continent from mid month onwards, increasing rainfall over the north. This will also increase the risk of cyclone activity across the north. These wild card systems may bring enhanced rainfall if they form and spread south from the tropics. We are seeing on some of the medium term modelling that moisture building up over the Indian Ocean is starting to be drawn into the west of the nation. Might have to take a look at that in the medium term outlooks in the coming days.

DATA - Refer to video for more information and the model comparison and context about all the forecast products you see from me.


12Z Euro Surface Pressure Pattern and Rainfall Distribution - Next 10 Days

The pressure pattern remains dynamic over the east of QLD through much of eastern NSW and down into southeast NSW where onshore winds and heavy rainfall is expected to continue today with locally intense rainfall possible tonight and tomorrow. That activity will start to ease from later tomorrow. Storms will feature through eastern QLD and back up to the tropics where some of the storms in QLD could turn severe with all modes of severe weather and the tropics is where you find the gusty squalls. VIC, SA and WA looking mostly settled for this week near ridging and the eastern parts of NSW and QLD should see conditions easing as well. Severe weather should cease by mid week for most of the nation in the absence of storms. So we are seeing the worst of the weather for this sequence behind us. Next week we reset and could see moisture increasing over the tropics, spreading south and southwest through WA and more showers and storms extending through that state and into Central Australia and into a new trough over western QLD and NSW.

12z Euro Precipitable Water Anomalies - Next 10 Days

Moisture values are still very heavy over the east but with the upper low and new surface low forms, that will take the humid air off the east coast, propel the humidity northwards and clear it out of the inland areas for much of this week. The humidity over the north of the nation is set to increase and likely to feed southwards throughout WA over this period, likely to lead to a chance of a few showers and thunderstorms inland. The weather over the southeast inland remaining dry and seasonal, so some much more typical Autumn weather is forecast for this week into the weekend and next week. WA could start to see more moisture increasing offshore the northwest as the MJO approaches the eastern Indian Ocean. Moisture over the northern and central parts of QLD could stay elevated with the onshore trade winds continuing.

12z Euro Rainfall Accumulation - Next 10 days

Refer to video for more information

12z GFS Rainfall Accumulation - Next 10 days

Refer to video for more information

12z CMC Rainfall Accumulation - Next 10 days

Refer to video for more information

12z Euro Rainfall Accumulation - Next 15 days

Refer to video for more information

12z GFS Rainfall Accumulation - Next 16 days

Refer to video for more information

More coming up on the upper low today and see how that impacts the flood zones and your properties in the east. Otherwise will have a look at the climate drivers, particularly the SAM and MJO as well, finally some shifting going on next week.