MONDAY MORNING WEATHER - STORMS CLEAR EAST THROUGH NSW. NEXT SYSTEM IN THE EAST POSES NEXT THREAT.

Updated: Apr 4

The weather is expected to ease further today over the southeast with the low moving away from the coastal areas with a drier west to southwest flow in the wake of the system bringing in dry air for a period. Flood waters for parts of far eastern Victoria will begin to ease through the coming days.


Severe storms with a trough over northern NSW overnight will continue to march east this morning and likely clear the coast later today.


The rest of the nation is looking pretty good with a high in the Bight controlling conditions. The weather is expected to be seasonal with temperatures expected to rise through this week over much of the central and southern interior with the slack pressure pattern.


For the eastern inland, we have to watch the developing upper level trough over VIC on Tuesday that will move into the eastern inland during Wednesday and remain slow moving for the remainder of the week.


There is some chance that we could see heavy rainfall return to the east coast with the chance of flash flooding mid to late week and a renewal of minor to moderate flooding for the NSW coast. But overall confidence is low.


Most elsewhere the weather is forecast to remain stable, with the west joining much of central Australia in warming up. That will be in advance of a weak change by the weekend that could spread in some showers once again for the SWLD.


Across the tropical north, maybe one of the last waves of weather passing from east to west may bring late season falls to FNQ and the Top End. This moisture may in fact hold the key to spreading rainfall chances across WA and much of Australia over Easter into ANZAC Day IF it gets into the Indian Ocean and drawn in ahead of the frontal weather over southern Australia.


For now the weather continues to irritate the east with further severe weather risks this week but the remainder of the nation should be in stable air for the most part.


Lets take a look

FORECAST

Rainfall Next 10 Days

Rainfall numbers are coming down for the west with the tail end of a rain band exiting the south coastal areas of WA. Some moderate falls this morning should be gone by tonight. Same story for the east, storms should be gone by this afternoon and much of the east should be dry later today and for Tuesday. Showers will likely develop from mid week for southeast and eastern Australia with some of the showers tending heavy at times with a flash flood risk. Watching closely to upgrade this risk further in the days ahead. Over the northern areas, dry and hot weather is expected to continue though showers may begin to increase for FNQ later this week into the weekend with the next tropical wave moving in from the east passing west. That may introduce showers and thunderstorms into the Top End over the end of the forecast period. The weather pattern looks dry in the southeast and southern areas of the nation for a while and that may extend back to the western interior of the country. Some frontal weather may graze the southwest coastal areas and slip through Tasmania later this week bringing light falls, a sign the weather is starting to shift further towards the cooler season rainfall opportunities. Finally, the pattern to watch is that tropical moisture that can run across the northern parts of the nation and land in the Indian Ocean leading to moisture being drawn into the jet stream and then into frontal weather in the medium term. That would be an opportunity to see an Autumn Break type system passing through southern Australia.

SHORT TERM CLIMATE DRIVERS

SOUTHERN ANNULAR MODE - SOUTHERN OCEAN - CONTINUES TO BE NEUTRAL FOR MOST OF THIS PERIOD.

A weak positive phase today is set to turn back to a brief positive phase, what you are seeing is the wave length between events now shortening a bit, which can be indicative of La Nina waning. Overall the period should be classified as neutral and minimal impact is expected from this driver for a little while, but there are a handful of members that shove it back into positive territory again.

MJO - TROPICS - NOW LIKLEY TO HAVE LITTLE INFLUENCE MOVING THROUGH THE NEXT 2 WEEKS

No impact from the MJO is likely in the coming 2 weeks and it's position closer to the equator means it may be north of the nation until we get to later this year. Note that in recent updates it is starting to expand into the western Pacific.

THUNDERSTORM FORECAST THIS WEEK

Thunderstorm Forecast Monday

Thunderstorms are likely in isolated coverage over the northern tropics during the afternoon and evening. A moderate chance of thunderstorms returning near a trough once again during the day over southern QLD and into northern NSW. Severe weather is also possible with this trough.

Thunderstorm Forecast Tuesday

A low chance of a thunderstorm or two over the far north of the nation during the afternoon and evening.

Thunderstorm Forecast Wednesday

Weak trough over the southeast inland could flare off a few showers and thunderstorms over parts of eastern NSW later in the day. A few thundery showers possible over the northern tropics but they will be hard to find. This forecast may be upgraded for the east in the coming 24hrs.

Thunderstorm Forecast Thursday

Thunderstorms remain more isolated over northern areas on Thursday but may also appear over the east with an upper disturbance but the forecast confidence is not especially high in NSW. This forecast may be upgraded for the east in the coming 24hrs.

Thunderstorm Forecast Friday

Isolated thunderstorms are possible over the north during the afternoon and evening. There is the low chance of a few morning thunderstorms over the coastal areas of NSW with the chance of heavy rainfall.

SEVERE WEATHER REGIONS

Severe Weather Watch - Heavy Rainfall - Wednesday through Saturday

As mentioned last night, there is the chance of heavy showers and thunderstorms along the NSW coast during the latter part of this week with a moderate chance of flash flooding developing for pockets of the coast. We can be more specific once this system is off the board over southeast VIC later today.

MEDIUM TERM FORECAST - April 11th-18th 2022

Moisture Spread

Great odds of seeing the last of the tropical waves passing through the tropics in the medium term with some heightened risk of showers and thunderstorms. There may be moisture remaining in place for eastern areas of the nation in weak onshore winds for NSW but a stronger flow for QLD where the trade winds could bring in some heavier falls. Moisture may also begin to be drawn into the westerly wind belt leading to more rain and cloud cover over much of southwest and southern Australia.

Rainfall Anomalies

Rainfall anomalies for this period are remaining fairly neutral for most areas away from the northern tropics where there is evidence of that lingering wet season influence via the tropical wave. The bias for drier weather remains over inland areas however, has been softened to reflect the uncertainty surrounding the development of moisture out of the northwest and north of the nation feeding into weather systems moving through the Southern Ocean. Timing is everything.

Temperature Anomalies

No change to the temperature anomalies through the nation for the second week of April. Above average temperatures will continue for large sections of interior Australia with a broad high pressure ridge in place and slowly moving through and extending through the southeast of Tasman Sea leading to a warm northwest to northerly flow establishing over the southern parts of the country. Pockets of the nation, being the southwest, the far east and northeast of QLD could see below average temperatures, but the nation as a whole seasonal to above seasonal temperatures.

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.


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

The latest Euro still has the rainfall event in the east clearing away today with the low and trough lifting offshore and the rainfall over the west is also starting to ease as well with the low pressure system shifting offshore the Southern Coastal areas of WA. Most elsewhere is expected to remain dry and stable with high pressure in full force above and at the surface. So for SA and much of Ag areas of the east, the weather is forecast to be dry and mild to warm with no real change to that pattern for this period. We can see frontal weather well to the south of the nation which is assisting in propelling cold air northwards from the Southern Ocean and this is contributing the rainfall events over the eastern parts of NSW and QLD. Over northern Australia, fairly settled and hot with the build down though there may be an increase of moisture passing through from east to west along a tropical wave. Out west, there may be an increase of frontal weather just offshore which could lead to showers clipping southern coastal areas and darting across the Tasmania. Overall the most active weather is expected in the east again.

12z Euro Precipitable Water Anomalies - Next 10 Days

Moisture values to watch is still up over northern Australia through the period with that holding the key to potentially breaking the back of the dry into mid to late this month, in line with seasonal averages. The weather until then dominated by below seasonal humidity values for much of the nation away from the east.

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

I will take a look at the severe weather risks for the east later this week, later this morning. Also a look at Northwest Cloud Band Season, and are we likely to see that break the back of the dry spell in a few weeks for much of southern and southeast inland Australia.