SA AND WA - DRIER AND MORE SETTLED WITH THE HIGH PRESSURE IN CONTROL.

But there may be some weather developing over southwest areas of WA with a strong cold front approaching the Bight, the northern most aspect of this system could bring a few showers and storms to the region later Friday into Saturday with mainly light falls and a cooler shift.


That same front will combine with the high pressure system over the southeast to bring a warmer spell of weather for SA and add to the dry spell which has been gripping the state for the past 10 days. No signifcant rainfall is expected with the frontal weather at this time, but it could become more unsettled over eastern areas as a wave develops on the front, once again the timing of this places the rainfall of meaning in VIC, NSW and the ACT.


A new high pressure system looks to move over WA later in the weekend and shifts over SA once again into next week. A new upper low or trough will approach the west coast of WA, and there is modest moisture, nothing overwhelming, but enough to see showers and thunderstorms return to the forecast for the region.


This may lead to more above average rainfall being observed in the southern Ag areas of WA.


For much of the interior, a dry airmass under a large scale upper high will lead to clear warm and sunny weather.


Let take a look

FORECAST

Rainfall Next 10 Days

Rainfall is forecast to become lean to non-existent over the interior portions of WA and SA so not much is expected away from coastal areas. Looking at WA first, the southern and western districts have 2 chances for rainfall during this time, with some moderate falls for southern areas possible with the first system on Friday, and light falls getting into the Ag Belt. Dry through the weekend but another wave of low pressure is likely to form offshore the west coast early next week. This may lead to showers and thunderstorms developing for western areas south of Carnarvon and this spreading south and east through the SWLD during the remainder of the outlook. Early indications is that some areas could see another month's worth of rainfall.

Rainfall Next 10 Days

Not much on offer for SA with the wet weather largely confined to southern coastal areas and over the Lower Southeast. Some of the rainfall may tend moderate in the far east during this evening as an upper low moves east. A dry weekend followed by another front early next week will send a cloud band through the state, but with the lower levels rather dry and the system reorganising, the overall threat of widespread meaningful rainfall is looking further east of the state for now.

MEDIUM TERM FORECAST - April 12th-19th 2022

Moisture Spread

Moisture spread has not been changed from yesterday though just increasing the coverage of impact over northwest of Australia in relation to the tropical wave getting into the Indian Ocean. But overall, the airmass is very dry for large parts of the nation and rainfall coverage over the southeast during this period is expected to be light with high pressure in full force so not seeing much getting through that area of sinking air.

Rainfall Anomalies

A rather benign period of weather for much of the nation with ridging in control across southern parts. This is normal in relation to the seasonal transition across the country. The northern tropics could see some above average rainfall via the tropical wave passing through during this time, but higher chances are over the northern coastal areas. East coast could see another east coast trough between Brisbane and Newcastle but once again, the signals are poor but has been flagged in recent days.

Temperature Anomalies

Warmer than normal temperatures are still forecast for large areas of the nation's interior and this is thanks to ridging over much of the nation. Around the upper and surface high, onshore winds will provide cloud cover and seasonal to below average temperatures are forecast. Watching the westerly wind belt south of the nation which could send up colder air over the southeast which has been flagged but confidence is not as high on that idea.

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

More details can be found in the video for the short and medium term. It helps to put into context the parts of the outlook that carries higher confidence for certain areas over others.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Moisture is set to deepen over the east with that persistent La Nina look to the distribution as well for the eastern states leading to the flood risk yet again. Watching the moisture offshore QLD as to whether that heads towards the SEQ coast this weekend. Otherwise the west and central parts of the nation extending into western NSW, VIC and QLD through to early next week under drier air for the most part with ridging. Then the fast flow pattern takes over and kicks out the humidity from the east early next week and fingers crossed a much drier picture develops for the east coast and rainfall and moisture returns to the southern coastal areas. We are still seeing the deepening moisture levels over northern Australia through the medium term as well taking us through Easter and into ANZAC Day.

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 GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis

A closer look in - rainfall will be highly variable with storms over the inland of NSW and along the coast depending on where convergence zones set up in advance of the upper low drawing in that moisture from the northeast to easterly winds.


Further west, the rainfall is looking lean on the GFS but I think there will be better falls with a change in the short term on Friday into Saturday and then again at the end of the run. Some of that first system will be of benefit to SA. The moisture lurking offshore at the end of the run may offer some hope of more rainfall for the end of the month.

More coming up from 8am EST looking at the severe weather potential and a more detailed look at May 2022. Many will be watching closely as to whether the wet weather comes back to southern Australia and leaves the east.

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