MORNING WEATHER PICTURE - WET IN THE WEST - THE EAST IS WARM AND DRY

Plenty of rain falling throughout the southwest of the nation with a barocline passing through with moderate falls being observed. The rainfall will however will be confined to the southwest of the nation, with rainfall unlikely to progress eastwards.


Otherwise the weather remains warm and dry over much of the central and eastern parts of the nation under a broad high - though there is some signals for rainfall to return over the central and eastern areas later next week.


But it is the weather early next week which is most contentious with model madness continuing, the modelling really struggling with a lack of aviation in the region, so it is back to old school forecasting, not just being a model fan!


Latest weather blog.

FORECAST


Rainfall next 10 days

WA seeing the bulk of the rainfall over the SWLD, moderate falls continuing today before that eases and clears tonight. My skepticism regarding rainfall over the eastern inland with that upper low were well founded with most models moving away from that idea and I think that is right, so rainfall remains mostly coastal through the south and east of the nation with onshore winds. Not too much in the way of frontal weather, apart from the system coming through during the weekend. Up north a weakening upper trough over QLD will drive showers, this trough moving west to trigger showers over the NT with light falls. Another burst of rainfall over WA in about a week will be the system that brings up rainfall chances for SA and then the southeast of the nation.

Rainfall Anomalies for the coming 2 weeks. September 9-23rd

% chance of exceeding rainfall for the coming 2 week window.

Temperature Anomalies Next Week - September 9-15th 2021

% chance of exceeding the median temperatures during the coming week.

Temperature Anomalies - Following Week - September 16-23 2021

% chance of exceeding the temperatures during this period.

DATA


12z Euro Surface Pressure Pattern for the coming 10 days

The pattern remains dominated by high pressure into the weekend for much of the nation, with the front that is bringing rainfall over WA this morning slipping south, suppressed by the large upper high over the nation. A follow up cold front will pass through the southeast this weekend bringing a sharp drop in temperatures again, this leading to showery weather over the southeast, this now expected to move off into the Tasman with NO low pressure system forming, as expected. Then new high pressure will move into SA early next week with fine weather redeveloping, and the cycle of above average temperatures developing out west will move east through mid next week ahead of the next front, which offers a greater chance of rainfall over the southern parts of the nation at this stage. That looks to develop as per the GFS and CMC, later in the period. Up north, showers and storms redeveloping as humidity increases.

12z Euro Rainfall for the coming 10 days

Rainfall lean and mainly coastal this week, the biggest rainfall event is over the SWLD this morning with a cloud band. As expected that rainfall will move southeast away from the nation beaten down by the ridge. Then we track another cold front passing through the southeast this weekend, but because of the dry air ahead of this system, not much rainfall is expected inland, though a band of rain may form on the front over southern VIC where the temperatures clash, that could lead to some moderate falls. Otherwise the showers post the front are coastal for SA, VIC and NSW with onshore winds. The next system of note coms through WA into SA later next week, that system has more of a chance of tapping into moisture dragged in from northeast to northwest winds.

12z Euro Precipitable Water Values next 10 days

PW Anomalies are well below average and that is denoted by the brown and red shading, courtesy of the change from last weekend and the large scale upper high trapping that dry air in place. The moisture does return over northern areas this weekend with humidity increasing for tropical areas of the NT and QLD. Then the dry air returns for southern and eastern areas behind a front that surges north on Sunday. The moisture finally overrides the dry air during mid next week and normal values return to most of the nation. The airmass change will take about a week to 10 days to complete so if you are living away from the coast, do not expect much rainfall.

GFS 12Z Dew Points - Next 2 weeks.

This also paints the picture of the drier air surging north in the coming days, but then watch the tropics starting to turn moist and that moisture surging south and west. That will become a bigger influence into October as the high pressure drops south and the fronts become less frequent allowing moisture to pool.

Northern Australia View

Medium term forecast due out later this morning and I will have a look at some of the influences on Spring rainfall and temperatures coming up at lunchtime today. Those losing hope of Spring rainfall should take a look at that later today.

50 views2 comments