MONDAY MORNING WEATHER - QUIET START TO THE WEEK - WET WEATHER BUILDS WEST, NORTH AND EASES EAST.

The weather pattern is flipping at the moment with a large high south of the nation providing that shot of dry air last week and a strong southerly change through the southern and eastern part of the country, now lifting that drier air into the sub tropics and pushing out the monsoon trough. The weather as a whole more comparable to March over many areas.


Mild nights, sunny days inland. Scattered showers and thunderstorms over the north with moderate rainfall totals, but below average rainfall overall, the weather out west turning wetter with more moisture running into the west coast troughs.


We are seeing that shift into the final phase of Summer with the patterns reflecting that as well.


This week the west of the nation will be dealing with more moisture and widespread rainfall thanks to a tropical feature sitting offshore, the moisture off that system being sheared east into a deepening heat trough in the easterly winds. Some fairly decent rainfall with thunderstorms is possible and many areas could see 10-20mm.


Northern Australia seeing anomalous dry conditions if the modelling is correct with limited showers and thunderstorms over the northern tropics thanks to the trough moving north of the nation and drier air being trapped in a weak easterly flow. This does sometimes happens in a transition period in the tropical phases ahead of more robust monsoonal weather, so will be watching trends up north.


Across the east coast, a reduction in showers in the easing onshore winds is expected from mid week and the latter part of this week into the weekend, could feel more like Summer time with less humidity and sunny dry skies reaching the east coast. So that will be a nice change from the dull weather.


Inland areas, benign weather continues for about a week more. Then we see humidity and instability values increase and that will lead to more showers and thunderstorms across the nation.


Lets take a look

Rainfall Next 10 Days

Rainfall is fairly lean for the coming 10 days with the guidance unchanged from last night. High pressure to the south, ridging through most of the nation. The tropics and down the west coast is where you find the more concentrated rainfall throughout the period with troughing and higher moisture content. The east coast will still see showery onshore winds but it will be mainly light for now. Signals are for rainfall to become more widespread as we move into the medium term and I do expect there to be warmer and more humid days developing for the second half of February.

FORECAST

Thunderstorm Forecast Monday

A weak surface trough over the four corners may produce a few showers and thunderstorms but mainly light falls. Showers and thunderstorms continues for the northern parts of the nation with some heavy falls, especially about the Darwin region with a flash flood risk. Thunderstorms may develop through the western interior with the chance of gusty winds.

Thunderstorm Forecast Tuesday

Scattered showers and thunderstorms will continue over the north and northwest of the nation as a trough continues to linger through the region. One or two areas may see flash flooding. Thunderstorms may be gusty at times through the central interior of WA but below severe thresholds and these may extend into SA along a prefrontal trough, but once again no severe weather expected and these will be elevated. Isolated thunderstorms over the eastern parts of the nation but more scattered along the coast as a weak trough approaches the coast in onshore winds.

Thunderstorm Forecast Wednesday

Thunderstorms are expected to continue over northern Australia and through to the northwest of WA where a trough remains stationary. Ample moisture will lead to afternoon thunderstorms inland of the coast, some of these might be steered towards the coast at the end of the day. Over eastern ranges of Victoria into the southeast of NSW and the ACT, afternoon thundery showers with a weak pressure trough passing through will deliver some very isolated areas moderate rainfall, but they will be hard to find.

Tropical Depression Watch This Week

The risk over the north is reducing a little on some of the latest model data, however I do believe later this week we will have a few lows to watch north of the NT and towards the Indian Ocean which may enhance rainfall. I think we are seeing a little more drier air coming into the region which may delay the onset of the depression formation or even push it further north, will adjust the chart this afternoon

DATA - Refer to video for more details on the short and medium term break down on the GFS.


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

The pattern settled, the air relatively dry and this is leading to below average rainfall expectations for the coming week over much of the nation. The tropics will see below average rainfall at the moment, with the air also drier than normal. That is unusual and should last about a week. The weather over the east, dominated by onshore winds. The weather in the west dominated by the trough over the inland of the coast and this combining with the moisture shearing off a tropical feature west of the nation which will be moving slowly southwards. So this may be the wettest area in the nation, which signals the shift into the final phase of Summer time across the country with the moisture and rainfall increasing over western and northern areas of the nation, heading into March. Dry weather over the southeast and eastern inland for about 7-10 days with very isolated showers and thunderstorms possible.

12Z Euro - Precipitable Water Values - Next 10 Days

Dry air continues to take hold of the nation and really, looking at the extended Euro, you can see the drier air, below average moisture content leads to below average rainfall expectations, something that goes against the grain of the current climate drivers. Not uncommon after such a large expression of widespread above average rainfall. But this certainly backs up the extreme weather conditions we have seen in recent years. The moisture should recover from the second half of February from north and east then spreading south.

12Z Euro - Rainfall Accumulation - Next 10 Days

Refer to video for further information

12Z GFS - Rainfall Accumulation - Next 10 Days

Refer to video for further information

12Z CMC - Rainfall Accumulation - Next 10 Days

Refer to video for further information

12Z Euro - Rainfall Accumulation - Next 15 Days

Refer to video for further information

12Z GFS - Rainfall Accumulation - Next 16 Days

Refer to video for further information

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