MORNING WEATHER WRAP - THE HUMIDITY AND RAINFALL EXPECTED TO SWEEP SOUTH THIS WEEK.

The tropics are tending more active, we have been following that for weeks now. This moisture is expected to erupt into more widespread showers and thunderstorms for the next week, this moisture then spreading south and east via upper level winds through SA and into the eastern inland.


The moisture is expected to stick around, but there will be waves of low pressure passing through this warm moist airmass, to bring up widespread showers and thunderstorms for large chunks of the nation.


The west of the nation, you are feeling dry and pleasant over the SWLD but away from there, expect the humidity to creep south into the southern and eastern interior.


Tropical weather is expected to fuel the nationwide stormfest and the moisture is expected to deepen over this part of the world through the outlook period, lifting to near record values for November.


FORECAST


Satellite Imagery Sunday

The moisture deepening over the central and northern interior with scattered to numerous showers and thunderstorms. The cloud cover thick, as we have been talking about this is going to lead to below average temperatures over the coming fortnight, stifling the chances of any more searing dry heat for a long while through the nation. The moisture is recycling over the east coast as winds veer into the east on the northern flank of a high pressure system. The west, remaining cool, the cooler spring persists with yet another front allowed to pass through the gate, bringing a few showers Monday.

Rainfall Next 10 days

Widespread rainfall and thunderstorm activity starting to unfold over large parts of the Outback with a deepening trough extending through WA and moving east into the NT and SA. Showers and storms, will be heavy at times over western interior. The weather graduating east and southeast during the course of this week. Scattered showers and thunderstorms developing for SA from tomorrow and moving southeast Tuesday and heading into NSW and VIC from Wednesday through Friday, then onto much of QLD. Scattered uneven rainfall expected with this feature. The showers increasing for the SWLD on Monday with a front passing through but light falls. The tropics throughout this period becoming more active but as mentioned for the past 2 weeks, the interior portions of the nation are expected to be impacted by near record early onset rainfall.

Thunderstorm Forecast Sunday

Thunderstorms are expected for much of northern and northwest Australia as a deepening trough and large moisture plume begins to shift south and east through WA into the NT. Some of the thunderstorms are expected to be strong to severe with damaging winds possible. Storms mainly inland of the coast for the day time, but they could develop closer to the coast at night. Scattered showers and thunderstorms along a weak trough through Central QLD are expected to be non severe. Stable air elsewhere under a large ridge.

Severe Weather Outlook

Tuesday 2nd of November 2021

Thunderstorms will move into SA with a trough, which will be invigorated by an approaching cold front that will move into the Bight. Strong gusty winds are possible with thunderstorms over outback areas of SA and the NT with moderate bursts of rainfall.

Wednesday 3rd of November 2021

Strong upper level winds and the presence of a trough will see thunderstorms redevelop in a deep moisture profile. The storms will have a moderate to high chance of strong wind gusts and heavy rainfall leading to pockets of flash flooding. There will be a low to moderate chance of severe thunderstorms over much of SA moving into western VIC and NSW with heavy rainfall and strong gusty winds the main concern.

Thursday 4th of November 2021

The trough will get kicked northeast through NSW and into QLD during Thursday with scattered thunderstorms along and north of the axis of the trough. Storms will produce strong gusty winds and heavy rainfall leading to flash flooding, but once again, more likely over the interior of the nation where the moisture is deeper and the upper level wind profile plus a trough nearby, fuelling the unstable weather and potential severe weather risks


DATA


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

The synoptic pattern is still largely unchanged with the unsettled weather spreading from the north through to the south and east during the coming week, this introducing us to a very damp period with high humidity and multiple states seeing severe weather potential. There are two waves on the Euro for the southeast and eastern states to watch. One coming through this week and another over the weekend. The GFS has 3-4 waves of low pressure and deeper moisture and the CMC is very wet with persistent low pressure. The Euro more conservative and allowing there to be breaks in the humidity for the southern states between fronts, but for eastern and northern inland areas sweeping into the northwest of WA, the moisture levels and thunderstorm activity will be constant from mid week right through to mid month as profiled. The southwest of the nation remains persistently cooler than normal with light rainfall at times with onshore winds.

12z Euro Precipitable Water Anomalies - Next 10 Days

The moisture content is running very high over northern parts of Australia and that signal from last week of that moisture spreading south via upper level winds, feeding into troughs bringing widespread showers and thunderstorms to all states with the southwest of the nation and Tasmania seeing less humidity. The values over northern parts of the nation are near record levels for November which equals a very elevated chance of above average rainfall moving forward.

12z Euro Rainfall Accumulation - Next 15 days

The wet signal continues for much of the nation from this week. The southwest of the nation will remain drier for this period under persistent ridging.

12z GFS Rainfall Accumulation - Next 15 days

Using the deterministic run of the GFS you can see the uneven distribution of rainfall across the nation - I cannot stress this more, throughout most of the nation, your number will vary. Some areas will absolutely cop it while others will get a light sprinkle.

12z CMC Rainfall Accumulation - Next 15 days

A very wet signal continues from this week through mid month, this has been relatively unchanged in the longer term CMC and now is creeping into the short and medium term.

12z CFS Rainfall Accumulation - Next 6 weeks

Still significantly wetter as we go through to mid December and more on that coming up during Tuesday. Note the tropical influence now being identified by this model.

I will have your Summer Outlook for 2021/22 coming up later this morning.