SA - SHOWERS DECREASING LATER TUESDAY, MORE RAINFALL IS POSSIBLE LATER THIS WEEK

A broadly unstable and cold gusty southwest to westerly flow continues to drive widespread showers with the chance of that hail and thunder to persist, some heavy falls possible over the usual wetter areas in these setups which will be welcome.

As we track into Tuesday, we are likely to see a piggy back system moving through the region with another burst of showers but that should be on the southeast coastal areas as we move into the end of the day, with some easing forecast for the southern areas of the state by nightfall.

That sets up some chance of widespread frost developing with severe frost possible about higher ground but the bulk of the heavier frost may be found in NSW and VIC mid week.

As a weak ridge moves through the state mid week to Thursday, conditions feeling OK after cold starts with a northwest flow developing.

However, out west and over the interior, moisture will continue to be fed into the jet stream leading to a band of rain running over northern areas and back into WA. Some of this moisture may begin to be shifted south and southeast as we track into the latter part of the week in advance of a cold front moving through the Bight.

This is where we might see another rain band passing through the southern Ag areas with possibly moderate falls developing once again with some luck. But I want to see the current event passing out to the east first to see how this next event shapes up.


So stay tuned throughout the week.

FORECAST

Rainfall Next 10 Days

As mentioned last week, most areas could see this event that has passed through bringing a month's worth of rainfall and that did occur. And further showery weather is on the cards for the next 7 days, perhaps a day or two break with a weak ridge passing through. Then another system is forecast to approach later this week with another moisture in feed to increase rainfall chances along this feature. However, I am not quite sure on the orientation of this system just yet and I think we will know more by Wednesday. The impacts of how this current event concludes over the eastern states will have an impact on the next system rolling out of the west. But most of the state is forecast to see some further rainfall over the coming week. Moisture building throughout inland WA may also bring up rainfall chances again through the medium term as well.

Further moderate rainfall is expected over the southeast of SA and Ag Areas after widespread 30-60mm of rainfall in the past 24hrs.

Thunderstorm Forecast Tuesday

Thunderstorms are present tonight and again tomorrow with a risk of damaging winds and small hail possible. Thunderstorms are forecast to contract eastwards during the afternoon, so the risk clearing through Victoria by nightfall and NSW southeast and the ACT by overnight with more stable air by Wednesday.

Severe Weather Watch - Damaging Winds

Damaging winds have already been observed Sunday and today with that very tight pressure gradient leading too strong to gale force wind gusts on and with a front moving through NSW expected to move further east on Monday. A strong cold front to follow up the low-pressure system could also produce strong squalls with showers and thunderstorms on Monday night and into Tuesday morning. Conditions should ease from the west on Tuesday.

Hail Risk - Monday to Tuesday

Small hail is likely with scattered to widespread showers and thunderstorms with wind squalls of up to 100km/h, the combination could lead to crop damage, especially of young vulnerable plants.

Farmers and Graziers

We are already experiencing the major airmass change through the coming week, with cold and wet conditions and high wind chill developing over thre southeast overnight and into this morning. Only 5C about the Tablelands in NSW and VIC with windy weather and rainfall underway. Conditions peak on Tuesday before the weather warms somewhat on Wednesday and the winds ease.

Frost Risk Mid-Week

The cold air is forecast to be trapped under a weak ridge mid week, and as skies clear and winds drop out, there is an elevated risk of frost forming, especially about elevated terrain and away from the coast. Some of the frost could be severe in and around the ACT and southeast NSW, extending into northeast VIC.

MEDIUM TERM

June 6th-13th 2022

Rainfall Anomalies

Rainfall anomalies through this period largely unchanged, the moisture over the northern tropics is of great interest to me where we could see more above average moisture content. But as mentioned, this rainfall over this part of the world is going to show up as green on this chart, as this area should be dry. Mostly seasonal rainfall expectations elsewhere but the confidence is not especially high right now. Will have to see what that moisture does over the northwest and whether it comes southeast with any northward approaching frontal feature.

Temperature Anomalies

The cooler signal remains in place and relates to the cloud cover running through the nation and the colder air left over from the dual cold outbreaks taking a while to clear the country's interior. But the day time temperatures will be below average where the night time may move above the average. The overall pattern is connected to the developing IOD and the ongoing negative SAM phase.

DATA - Refer to the video for further information and it is critical to keep check of the data sets to understand where the next major weather events are emerging from outside of this period. It may be quiet now but I am all about preparation and ensuring that information is shared with you as soon as it is available.


00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks

I have more to say in the video but be aware that the forecasts will keep jumping around nationally. The cold outbreak should be on the way out tomorrow night and a drier pattern establishes across the inland and southeast for a period. But it does not look to last as more moisture runs through the northwest of the nation through Central Australia and into the southeast states. Some of this could be caught up into the westerly wind belt and further rain could develop this weekend but it is not clear yet on how that looks with the current system needing to be off the board before I can be specific about this. Over the north and northwest, the weather is forecast to turn humid and more unsettled with that moisture possibly moving south and southeast throughout the country, but once again how that looks is up in the air, so another day before we get better guidance.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The moisture values are coming down through the south and southeast as the dry southwest to southerly flow develops behind the large mass of rain in the southeast and east tonight. Drier air extends back over the southwest and west of the nation where high pressure is ridging through. Another pulse of tropical moisture is expected to sweep in from the Indian Ocean and race into the jet stream, spreading widespread cloud and potential rain across the nation. Some of this moisture may be swept into the cold fronts trying to approach the southeast but the timing is all over the shop. The pattern is of low confidence and will have consequences across the nation.

00Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z CMC - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z Euro - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis

A closer look in - this forecast is changing erratically and I will continue to add that the forecast confidence remains low beyond this current event over the southeast.

More coming up from 8pm EST with a look at the models and rainfall.

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