MONDAY MORNING WEATHER - THE COLD SNAP ON THE HORIZON BUT OUT WEST, WARM AND DRY WEATHER CONTINUES.

And the dry weather over the northern areas of the nation is starting to unfold as we lose the bulk of that very high moisture profile, lifting north with the dry colder surge pushing over the southern and southeast states. It is a complex weather pattern this week, but the focus is not on rainfall, but the shift in temperatures across the country.


The Autumnal Break via temperatures should unfold and a Winter preview for the southeast headlines the weather this week. The showery weather could be quite productive for southern and mountain Victoria and western and southern Tasmania, highlighting the shift to the cooler rainfall distribution which will become more of a frequent feature as we move into Winter.


For now, this appears to be a one off event over the coming weeks, with the main impact as mentioned across the country the temperatures falling below normal, and frosts possible for large areas of the southeast inland this weekend.


Farmers and graziers should also be advised that the weather moving through during Wednesday to Friday in the region from SE SA, over VIC, TAS and southern and central NSW into the ACT could stress stock not adjusted to these temperatures and caution is advised over this time. It is this time of year where these events can pack a punch to stock, off the back of the warm and humid year we have had, the impacts could be above normal.


Overall the pattern out west is dry and boring with warmer than average temperatures while the east enjoys the Winter preview. The next rain maker for the west looks to appear from later Sunday if not this time next week with moisture streaming out of the Indian Ocean into a front moving closer to the west coast.


Conditions over the north should also resemble more typical weather for this time of year but this dry season will not be a typical, with the weather to be more humid than what is expected through the drier months.


Lets take a look at the short and medium term.

FORECAST

Rainfall Next 10 Days

Certainly one of the drier weeks of Autumn so far this year and really one of the drier weeks of the year nationally. We have got the rain event over the southeast and even calling it that is a stretch. Showers and colder weather will descend on the southeast from Tuesday night and become more widespread Wednesday and through Thursday before easing Friday. There may be some scattered showers over inland areas of the eastern inland with the risk of thunderstorms, but light falls on and east of the divide. As we look over the northern tropics, rainfall numbers coming way down. The rainfall could be moderate over the northeast tropics but reserved for Cape York. Showers and a few storms in onshore winds for QLD may become a little more widespread over the southeast as onshore winds redevelop later next week into the weekend, and that may be the case for northern NSW too. That rainfall is forecast to be connected to the SAM tending positive. The next rain event is forecast to approach the southwest of the nation from about a week from now and that offers the next batch of wet weather for SWLD of WA and then run over southern parts of the nation thereafter. This would be the next best chance of rainfall for the southern and then southeast inland of the country.

Thunderstorm Forecast Monday

Thunderstorms are forecast in isolated fashion over the tropics, and along a weakening jet stream across the inland of WA and QLD. No severe weather is expected.

Thunderstorm Forecast Tuesday

NlL THUNDERSTORMS

Thunderstorm Forecast Wednesday

Isolated thunderstorms are forecast to develop over the southeast with a cold airmass moving onshore. Local hail and squalls are possible for southern VIC and western TAS. A few thunderstorms are possible over a very wide area over inland QLD and NSW.

Thunderstorm Forecast Thursday

Isolated thunderstorms amongst a showery airmass could see local hail and squalls continue for southern VIC and western TAS.

Thunderstorm Forecast Friday

NIL THUNDERSTORMS

Farmers and Graziers - Mid Week

Be aware that despite the lack of rainfall this week, we are looking at significant cooling of the nation and below average temperatures with strong southwest to southerly winds and cloudy skies with a few showers, may be enough to place some stock into stress with the event easing over the weekend.

Frost Outbreak - Late Week

Watching the numbers closely as we could start to see widespread frost developing for inland areas of NSW, some of that could tend severe through the southeast near the ACT above 600m but will evaluate the risk mid week of severe thresholds. For now this is a heads up forecast.

SOUTHERN ANNULAR MODE - POSITIVE THIS WEEK.

The SAM is turning positive this week before it turns back to neutral values through the weekend coming. But we should see the impacts of the positive event during the latter part of this week with rainfall increasing over the northeast and east of the country and drier weather persisting for the west. Then as the SAM turns neutral, conditions should return back to seasonal across the country and rainfall redevelops for southern Australia.

MEDIUM TERM - May 8th-15th 2022

Rainfall Anomalies

The wet bias does want to keep on going through northeast parts of the nation with persistent troughing and ridging combining with the onshore flow (via the positive SAM) to bring more rainfall for a lot of QLD and into NSW. The southwest seeing an increase in wet weather after this dry week, with a long wave trough parked in the region combining with the moisture streaming out of the Indian Ocean. Elsewhere, no strong bias for the rainfall distribution to be anything outside of seasonal.

Temperature Anomalies

The cooler bias continues for the west after a warmer week this week, the temperatures will come down and the weather in the east will warm up through this period. So overall, the pattern will flip during this time. Northern areas still running above average with humidity set to return from the north and east.

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 weather is relatively benign today with a settled and Autumnal pattern continuing to unfold. Though all the action is developing to the south of the country with a deep cold airmass moving northeast today, propelled by a high that takes a step back to the west. Now looking into Tuesday and Wednesday we should see a band of showers push through SA, into VIC and TAS. North of the system we are looking at showers developing along a weak trough passing through inland NSW and into QLD, that system then moves eastwards by Friday and clears offshore. The showery cold wintry weather however will keep going from Wednesday through to the weekend for southern VIC and TAS and pockets of southern SA. The pattern eases by Sunday for the southeast. The next rain event may form as the airstream turns southeast to easterly as the SAM turns positive. The rain could be heavy through inland QLD and dip into NSW before that system too starts to become more coastal through next week. Out west we have timing issues on the front and trough passing through over the weekend and again next week, with both bringing areas of rain but the coverage remains to be the issue. The north of the nation, feeling pretty good with the drier air from the south surging northwards.

12z Euro Precipitable Water Anomalies - Next 10 Days

The moisture content is forecast to run across the nation via the jet stream and remain in place but this graphic shows the importance of low pressure, so you can have all the moisture you want, but you need the lifting mechanism in phase with it. Now the jet stream will begin to retreat northwards through the period and the moisture becomes trapped over the east and northeast by the weekend and possibly redeveloping over WA ahead of weakening cold fronts. This is where you will find the more robust rainfall events. The cold dry air that moves over southern Australia will dominate the weather for the southern and southeast inland parts of the country through to next week so inland areas are dry for about week. The moisture over the northeast and eastern inland of the country needs to be watched carefully ahead of an upper trough this weekend which could produce some more above average rainfall.

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

We will take a look at the La Nina once again and the impacts moving through the Spring and what the heck is this talk of another event and what are the chances?