MONDAY MORNING WEATHER - THE SEVERE WEATHER PEAKS IN THE EAST TODAY. UNSETTLED WEST AND NORTH.

Updated: Mar 28

The remainder of the nation is in sinking dry air as we move through the week and so as I keep saying, not ignoring SA, VIC and the western portions of NSW and QLD, your weather is not changing much from day to day through to about the end of the weekend. It is Autumn in the south and these dry spells are normal as we transition and quite frankly, I want to be seeing them now, rather than in May. Means things are somewhat on track.


For the east, the seasonal wet weather continues though at above average thresholds for northeast NSW and southeast QLD. These regions could see excessive falls over 200mm in the coming days so stay close to warnings.


For the remainder of the eastern inland, the showers and storms should begin to decrease from later tomorrow as the upper low moves eastwards. The drier air will flush out the remainder of the rainy weather and the rest of the week is expected to be fine and sunny.


Across to the west and the skies are remaining unsettled with widespread showers and thunderstorms ongoing near a pool of very moist air and the remains of Charlotte offshore invigorating a trough in the region. So that unsettled weather is expected to stay with uneven rainfall distribution also staying in place.


The tropics have been very tricky to pin down, there is still a weak tropical low out there nearer to Cape York and PNG but the environment is not crash hot now for development into the potential TC Darian we were talking about on Friday, with models backing off from that idea. That means we could actually see a reduction in the coverage of showers and thunderstorms from later this week with the ridge in the southeast sending out a very large plume of dry air! Now that would be a sign of the times and that we could be moving closer to the Autumnal Break proper. Will look at that later this morning.


Otherwise, quiet most elsewhere and once we lose the severe weather risks over the west and the east from mid week, things look quiet for a while in terms of high impact weather issues.


Lets take a look

FORECAST

Rainfall Next 10 Days

Rainfall is largely unchanged from overnight with the pattern allowing for a large high to take full control and eventually eroding the rainfall dominance over the east, across the north and through to the west and southwest. The weather over the central and southeast inland is likely to remain lean to non existent, nothing too concerning for those who have had reasonable summer rainfall, but for some, it is hard to swallow after what has been a very dry 6 months. So we do need rainfall to come back quick smart for some in SA and VIC. Now for the east coast, heavy rainfall peaks today as outlined in the video with that slowly easing during the day on Tuesday with full clearance of the eastern inland not expected until mid week. The showery weather continues for the east coast. Over the northern tropics, the rainfall is likely to thin out later this week, with a nice tongue of dry air coming northwards propelled along by the high pressure system over Southeast Australia. In the west, the weather is expected to remain unsettled with some areas copping a smashing of rainfall while others missing out on the nasty weather but recording light falls. The uneven distribution of rainfall is expected to continue so drawing that type of rainfall spread out is challenging so understand, your number will vary. Conditions will dry out over the western interior by the weekend. The weekend for most areas looks pretty settled and dry although I have drawn in a very broad area of light rainfall over the eastern inland of the nation representing the chance of some inland showers and thunderstorms with the upper feature.

SHORT TERM CLIMATE DRIVERS

SOUTHERN ANNULAR MODE - SOUTHERN OCEAN - NEUTRAL FOR MOST OF THIS PERIOD.

The SAM is expected to turn briefly negative this week before turning back to neutral values. Some members do support another positive phase but it is not expected to be as large as this last expression. Noting this is the third time we have see the SAM drift below neutral thresholds supporting the waning La Nina in the ENSO region.

MJO - TROPICS - MOVING TOWARDS THE EQUATOR THEN COULD MAKE ANOTHER RUN AT THE NORTH OF THE NATION MID TO LATE MONTH.

The MJO remains in waters north of Australia for the coming 2-3 days and may flare off that tropical feature near the NT before it departs northwards. But the MJO is possibly to return into the northern Indian Ocean mid month, that would then put the region back into the risk of enhanced tropical activity developing.

THUNDERSTORM FORECAST THIS WEEK

Thunderstorm Forecast Monday

Thunderstorms look to become more widespread about the western interior of WA with severe thunderstorms possible. Heavy rainfall leading to flash flooding and damaging winds are the main issues out west as the remains of Charlotte approach. Over the north, showers and thunderstorms should also continue with the potential for damaging winds across the Top End and western Cape York with a tropical low nearby. The upper trough in the east is slower to move on by but will kick off another round of showers and storms through eastern NSW and extending north into southeast QLD. Severe thunderstorms are possible with all modes of severe weather possible.

Thunderstorm Forecast Tuesday

Deep moisture still stuck over parts of the southwest and west of the nation will be lifted by a trough in northeast winds leading to widespread showers and thunderstorms. Some of the thunderstorms will lead to heavy rainfall and a flash flood risk in some areas of the Lower West, Central West, Gascoyne and back through to the Pilbara and back to the tropics and NT. Developing tropical low offshore the NT may form into a cyclone with damaging winds in the rotating bands around the system. Storms decreasing in coverage over the northeast tropics. Lingering instability could give way to a pocket of showers and thunderstorms over northeast NSW and southeast QLD with one or two storms possibly severe about the border region.

Thunderstorm Forecast Wednesday

Thunderstorms will continue over the western and northwestern parts of the nation with the lingering moisture from Charlotte but also the secondary moisture surge coming in from the Indian Ocean spreading southeast via the jet stream into the Pilbara and Gascoyne. Some of the storms likely severe with heavy rainfall and damaging winds. Damaging winds and heavy rainfall possible with storms near the tropical feature over the NT and northern areas of WA. The east finally stable with a dry airmass and onshore southeast winds with high pressure moving in.

Thunderstorm Forecast Thursday

Thunderstorms are forecast to continue for large parts of the west with the secondary pulse of moisture moving through and feeding a trough in the region leading to the chance of severe storms with heavy rainfall and damaging winds. Over the northern tropics, the spread of the thundery weather is determined by the track of the tropical system in the region. There may be a few thundery showers in advance of a southeasterly change up the NSW and SE QLD coast.

Thunderstorm Forecast Friday

The large high in the Bight will start to break down the storm risk for much of the nation with stable drier and cooler air throughout many areas. The remains of the moisture plume landing over the west coast could give way to a few strong storms, some with heavy rainfall leading to flash flooding. A few thunderstorms also over the north with the usual afternoon and evening activity.

SEVERE WEATHER RISKS CONTINUES

Severe Weather Risks - Monday through Wednesday

No change to the guidance. We have now tracked the guidance of the moisture from Charlotte into a trough and as warned all through last week that a severe storm outbreak would unfold, we have seen that yesterday with all modes of severe weather likely for the days ahead. Remain weather aware. Large hail will also accompany the larger storms.

Severe Weather Watch - Next 48hrs

Flash flooding remains a very high risk and the main concern over the coming 2 days as the upper low slowly moves eastwards leading to a larger spread of rainfall and thunderstorms along the coast. Some of the rainfall rates could exceed 100mm/hr under the streams of showers and thunderstorms, which will result in dangerous flash flooding.

TROPICS - REMAINS A SLOW MOVING FEATURE.

Tropical Depression Watch

There is a weak tropical depression to the west of Cape York. The system will remain slow moving and may turn back east into the Coral Sea but may also meander along for sometime this week before adopting a westerly track. At this time the risk of major weather impact are offshore but all waters are in play for this depression to move through, guidance becomes clearer from mid week.

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 trough in the east should begin to edge east in the coming 2 days with the heavier rainfall spread also contracting eastwards from today. Showers and thunderstorms in the eastern inland will move away offshore by Wednesday and a resumption of showers along the coast in onshore winds will take us through to the weekend. For the west, scattered showers and thunderstorms are forecast to continue with a deep trough in the region and the remains of Charlotte still shearing off into the region, producing widespread falls. The coverage however will remain uneven in distribution but there will be plenty of storm activity about through to about Thursday before conditions clear. And for the north, the routine showers and thunderstorms continue for now, but with the tropical depression not evolving past a low pressure system offshore at this time, it may open the door for some drier air to win out and surge north this weekend bringing a taste of the dry to the northern states. That is courtesy of a high pressure system which is likely to control the weather for much of the rest of the nation with dry and mostly sunny weather, though falling temperatures later this week as the high recentres over the Bight.

12z Euro Precipitable Water Anomalies - Next 10 Days

The moisture values as per the last week of advice will be found on the periphery of the large scale upper and surface over the next week. The high will take a step back mid to late week and then slide through the southeast states by Friday. This will send a fairly robust surge of southerly winds with that dry air moving through the eastern inland and possibly reaching the sub tropics this weekend with a clean out of the wet weather. Out west, the deep moisture is forecast to remain in place for the remainder of the week but conditions will begin to dry out a little as another high ridges in from the west. A weak front also will knock the humidity out for a period. Finally, there is some weak evidence that we may see an upper trough over inland QLD or NSW later in the weekend, which could trigger inland showers and thunderstorms but the moisture profile is limited.

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 today including a look at this crazy La Nina speculation by some agencies about it not leaving and how that would impact Australia's weather moving forward, medium term glance, to see how long the dry spell is ongoing for the southeast and central inland and your state based forecasts this evening.