The west and south tending hot to very hot with dry easterly winds developing as the positive SAM impacts are being felt, the lag between the SAM reaching positive and the weather responding is about 2-3 days generally.
We are seeing the weather turning quite wet on the east coast from this weekend and through next week as a result. The onshore flow with the low pressure troughs developing throughout QLD and NSW and then dipping into VIC will lead to more humid and unsettled conditions.
Over northern Australia, thunderstorms have become more widespread in recent days as moisture deepens and the trough over the Top End moves north. Another trough is expected to deepen offshore north of the NT and QLD will lead to low pressure system developing through the trough and this could form some severe weather potential this time next week for the north of the nation.
Out west and throughout SA, the weather relatively dry, settled with seasonal weather for coastal SA but tending warmer than average inland of SA and well above average over southern WA with hot easterly winds and the increasing fire dangers once again.
I will be watching very closely the severe weather potential for NSW and QLD over the weekend and be sure to check back for any updates on the analysis as this has got the hallmarks of developing rapidly and then most other agencies playing catch up. Also watching the tropical weather very closely with the chance of cyclone formation in the coming 7-10 days.
Lets take a look at the latest details.
Rainfall Next 10 Days
Rainfall guidance still a little bit murky at the moment but the confidence is growing for wetter weather over the north of the nation and along the east coast and adjacent inland of QLD and NSW including the ACT. The rainfall will spread into VIC but more patchy in distribution with many areas going dry the further west you go through VIC. SA looks dry for this period still but watch up north with the tropical weather building as that may change with the moisture seeping southwards the nation. WA mostly dry over the southwest of the state with the ridge firm in place and that dry slot will move over Central WA. Obviously over northern areas the weather is expected to remain showery with the monsoon building over the week but the heaviest of the rainfall is likely to be found over the NT at this time during this period. But as per SA, watch the tropical systems movement over the coming weeks as cyclones that have large impacts on WA during this time of year, form north of Darwin.
Thunderstorm Forecast Saturday
Thunderstorm activity is expected to increase over northern NSW and into southern and western QLD as a trough deepens a little and starts to feed off the easterly flow establishing along the east coast. Storms have the potential to produce heavy rainfall leading to flash flooding and damaging winds. Thunderstorms will feature over the northern tropics with some of those gusty with damaging winds possible over the Top End and through the north of WA.
Thunderstorm Forecast Sunday
Thunderstorms are expected to become more widespread over the southeast, east and northeast of NSW and across the ACT, extending back over southern and western QLD and into the NT with some of the storms turning severe. Storms may produce heavy rainfall leading to flash flooding and damaging winds are also a risk over the NT. Thunderstorms near a west coast trough unlikely to be widespread over in northwest WA
Thunderstorm Forecast Monday
An upper level disturbance is likely to move into the central parts of SA and then northeast into western QLD later in the day. This will interact with a deep moisture layer and showers and thunderstorms are forecast to become more widespread and heavy through the period. Thunderstorms carry the risk of severe weather, mainly heavy rainfall leading to flash flooding and damaging winds. But come Tuesday that may change and more guidance will be offered over the weekend on that risk for QLD. Otherwise storms over the northern tropics will be gusty at times, damaging winds are possible. Scattered thunderstorms over the remainder of the east and northwest will be garden variety pulse storms.
Southern Annular Mode - Next 2 Weeks
The SAM has peaked at the positive phase in this wave and we will start to feel that influence in greater scale over the weekend and into next week and it is now being reflected in the rainfall prognostics. Widespread rainfall is penned in to fall over much of QLD, NSW and then into VIC and eastern SA in response to the broad easterly wind developing. The westerly winds over the south are moving further towards the south by the end of the weekend. There could be a secondary peak next week but only 2 members suggest a neutral phase into early March though some of the members diverge on this idea and this will be monitored next week.
MJO - Next 2 Weeks
The latest guide is pushing through the MJO a little quicker over northern Australia and not as amplified so this is why rainfall is not as heavy or widespread now on some of the models over northern and northwest parts of the nation. Widespread rainfall, thunderstorms and flood risks increasing again for the NT and parts of northern QLD. The north of WA may miss out on the heaviest of the rainfall with the MJO deepening over the NT and QLD. The moisture will spread south from the tropics into the central and eastern parts of the nation with rainfall also increasing in combination with the positive SAM. The speed of the MJO over the north will dictate rainfall coverage and cyclone development and placement.
DATA - Refer to the video for more details on the daily breakdown for the short and medium term
00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks
The guidance again, unchanged overall. More information can be found in the video, but to reinforce this point, you will see heavier rainfall over the east coast in coming days, that will move around. The higher chance of severe weather exists over QLD and NSW with the upper disturbance linking up with the deep moisture and where this takes place to produce the greatest chance of severe weather remains to be seen. Next week could be rough for some areas in both of these states. Strong storms over the north to continue ahead of the MJO rolling through from mid week and throughout the period. Note the rainfall is biased to the east and north, dry weather to the west and through central areas and as far east as about the Riverlands, through western NSW and into southwest QLD.
00Z GFS - Precipitable Water Values - Next 2 Weeks
Very deep moisture profile over northern and eastern areas of the nation will fold over the nation from the east and north as we go through this period. Where the low pressure sets up will dictate the spread of rainfall and severe weather throughout eastern and northern Australia and how far west and south the heavier, more tropical weather does end up moving.
00Z GFS - Rainfall Accumulation - Next 10 Days
Refer to video for more analysis and guidance
00Z CMC - Rainfall Accumulation - Next 10 Days
Refer to video for more analysis and guidance
00Z GFS - Rainfall Accumulation - Next 2 Weeks
Refer to video for more analysis and guidance and the state by state fly around for a closer look at your state.
More weather coming up after 9pm EDT with a look at all the model data and the rainfall guide from each. Enjoy your weekend.