MONDAY MORNING WEATHER - FROSTS EAST, SHOWERY OVER THE SOUTHWEST, DRY SEASON UP NORTH.

ANALYSIS

As many of you wake into the holiday Monday (lucky for some ;)), the weather is forecast to remain fairly similar to what we have seen over the course of Sunday with the bulk of coldest weather over the southeast, this leading to frosts this morning and for the coming week. We have showers and thunderstorms clearing along the south coast of WA and into the Bight with strong winds easing after a front brought moderate to heavy rainfall to parts of the SWLD on Sunday and coastal areas as well. The dry period continues for the northern and eastern interior, in line with the seasonal expectations.


Though the dry weather that is coming into the southeast today and through to about Tuesday is short lived, with the procession of frontal weather passing throughout the south of the nation from west to east over the course of the short and medium term.


SHORT TERM

We are looking at warmer weather this week for many areas as the flow pattern turns more northwest to westerly as a high gets into the eastern inland then offshore into the Tasman Sea, leading to a nice warm up thanks to the continental flow.


With cold fronts rolling through the southern and southwest of the nation, the winds are forecast to increase with the approach and passage of fronts, but rainfall is expected to be generally coastal this week, which has not changed in advice from last week.


A stronger cold front coming into WA on Thursday/Friday may offer a better chance of rainfall sweeping through the western interior and possibly reaching inland SA later in the weekend into next week. But for now the next week looks fairly quiet for the inland with seasonal weather nation wide.


LONG TERM

The question remains this week, how long does the ridge hold out over the interior and does this lead to drier weather continuing right through to the end of the month for large areas of inland Australia. That ridge will help to keep the flow in a northwest to westerly wind regime leading to above average temperatures for many areas.


Eventually a front will come through with a deep moisture source that will knock the high into the east leading to a better chance of rainfall and cooler weather developing towards the latter part of the month.


AREAS TO WATCH

Deep moisture offshore the NW of Australia is starting to shift in orientation in response to the persistent negative SAM phase, which is lifting the cold fronts northwards towards Australia, basically it is at a southern latitude to where it has been through May. The further north the frontal weather can come, the better it will be for large areas of southern Australia with rainfall increasing. The further northern the fronts come, the higher probability that it will drag in the deep moisture from the Indian Ocean.


Do not just watch Australian charts either, looking further west, the moisture over the Indian Ocean is exceptional for this time of year. That will play out in the weeks ahead and indeed months ahead. So, as I keep saying, enjoy the drier weather while it lasts in areas forecast to be quiet in the week ahead.


WEATHER VIDEO AM - MONDAY 13TH JUNE 2022

FORECAST

Rainfall Next 10 Days

Rainfall forecasts have not changed a huge amount over the weekend and that is good in a sense for forecasting confidence. The bulk of the rainfall is forecast to be along coastal areas in the south and southwest of the nation where we find the frontal weather most active this week. The rainfall will not graduate very far inland at this time with forecasts generally dry and much warmer this week north of the frontal passages. Moisture does not look to be in phase with the frontal weather passing over southern Australia. So perhaps not seeing the rain bands this week, but next week, we most certainly will see rainfall chances coming up over the nation as the high-pressure ridge begins to move away towards NZ. So that will start to allow moisture spreading through the country from west to east. Note that the rainfall is forecast to remain very much seasonal for most areas, a little drier in the east than normal, but off the back of a very wet start to the year, we can handle that.

WEATHER ISSUES

Severe Weather Watch - Sunday to Monday

Wind gusts of 100km/h have already been observed in some areas Sunday and this is into this morning before the low pressure clears eastwards and away leading to the winds easing and the watch expiring. I will be looking at the major system coming through on Friday to see if that has any severe weather potential.

THUNDERSTORM FORECAST

Thunderstorm Forecast Monday

Thunderstorms will move through the SWLD with a strong cold front, with the coverage decreasing the further east you go, with the trough and front sliding southeast as the low collapses south of the state.

Thunderstorm Forecast Tuesday

Thunderstorms is forecast to be mainly in the Bight on Tuesday with a couple of these clipping the Eyre Peninsula. This may also spread through southeast areas of SA and into western VIC at night, but coverage isolated.

Thunderstorm Forecast Wednesday

Thunderstorms mainly offshore the southern coast of Australia at this time, but watching the moisture streaming into the northwest of the nation to see whether that kicks off some thunderstorm activity during the course of Wednesday evening into Thursday ahead of the next front over the SWLD.

Thunderstorm Forecast Thursday

Thunderstorms are possible over the SWLD with the chance of some moderate rainfall as a weak front passes through. There may be a clap of thunder over the Torres Strait.

Thunderstorm Forecast Friday

Thunderstorms become more widespread over the SWLD and along the west coast with the approach and passage of the strong cold front with damaging winds a chance with storms over the SWLD.

MEDIUM TERM

June 19th-26th 2022

Rainfall Anomalies

Generally seasonal rainfall expectations across the country, but the forecast confidence remains relatively low.

Temperature Anomalies

The temperatures looking to moderate from that very warm bias across the country, and some indications of cloud cover developing throughout this period in the eastern interior and over the far west may lead to below average temperatures in these areas. The warmer bias continues for large areas of the interior.

CLIMATE DRIVERS

SOUTHERN ANNULAR MODE - NEGATIVE TO PHASE TO CONTINUE STRENGTHENING THIS WEEK

The SAM is expected to remain negative and stay strongly negative through the next week or so, this leading to a drier interior in the absence of moisture passing through the jet stream and cold fronts bringing winter rainfall in bursts to southern Australia which may increase in coverage.

DATA - Refer to the video for further information and context on the data sets.


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

Refer to the video for further context to the short and medium term forecast.

12z Euro Precipitable Water Anomalies - Next 10 Days

The moisture spread is fairly similar to last night but for the nation as a whole, the moisture will be more productive in the west than the east, where high pressure in the east keeps things settled, so expect cloud over rain for NSW and QLD for the short and part of the medium term. Moisture will return to the southeast and southern coastal areas with frontal weather starting to increase across SA and VIC this while continuing through WA with further rain and storms. This moisture is near seasonal for this time of year and will lead to seasonal rainfall expectations, with no major rainfall event evident just yet for the nation.


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

Watch out for the Climate Outlook for August to October coming up from mid-morning! A broad overview and a must read and viewing! State based forecasts this afternoon as well while we enjoy a little quieter patch!