MONDAY EVENING WEATHER - THE RAIN CONTINUES FOR THE EAST AND MORE FOLLOW UP LIKELY.

A wet phase continues for QLD with increasing rainfall across the tropical northeast with heavy falls also occurring for western QLD, some locations recording upwards of 100mm in the past 36hrs. The rainfall is forecast to amplify along an upper trough in SA mainly north of Port Augusta through the Flinders and possibly west to about Tarcoola and to about the salt pans.


The weather is forecast to move eastwards during Tuesday. That will be helped along by a front rotating through the southwest of the nation tonight leading to windy weather developing and thundery showers pushing through. This change could lead to the coldest weather so far this year for the SWLD.


Over the course of the next few days, the rainfall over the eastern inland is forecast to be patchy and lighter the further east you go, the trough likely losing integrity as it goes up against the ridge over the east.


Another front pushing through the southwest of the nation is forecast to run through the Bight and this too will likely bring another burst of showers and storms for the SWLD of WA Tuesday night into Wednesday before this system forms another rain over the southeast and eastern inland of the nation. This system could bring additional moderate falls and possibly some severe storms over VIC, NSW and southern and western QLD.


A drier airmass will develop through the weekend for the southern states with humid air still running through the jet stream from northwest to southeast, possibly keeping the rainfall and thundery weather ongoing for northern NSW, southern QLD and parts of Central Australia.


Moisture is still forecast to be running through the northern tropics into the start of the dry season, as warned a delayed onset to the dry season is forecast thanks to the waning La Nina. This will also add more moisture to the content through the coming week and increase rainfall chances as we move through the medium term.


Lets take a look

FORECAST

Rainfall Next 10 Days

Rainfall is forecast to continue at heavy rates over parts of inland QLD with one part of an upper trough and over SA with another upper trough passing through over the coming 24hrs. Both areas could see flash and riverine flooding. The weather is forecast to amalgamate and move east and southeast with patchier falls forecast to pass through from mid week. Showers with some thunderstorms could see moderate falls be achieved over the SWLD of WA. Some of the storms could produce small hail. Another round of thunderstorms is forecast to develop once again on Tuesday into Wednesday. Another front will run through the westerly wind belt on Wednesday into Thursday with another band of rain forecast to develop over SA, through VIC, NSW and QLD. Storms could become severe along a dry line producing moderate falls but the rainfall may not be as heavy as this current event underway. The weather clearing for southern areas during the weekend but may persist through the eastern inland during the weekend into next week along a jet stream. The moisture over the northern tropics are forecast to remain active with above average rainfall expected to continue through this period.

Severe Weather - Flood Risk QLD

Heavy rainfall of up to 150mm has already been observed over the past 36hrs and a further 50-100mm is possible over areas already seeing near record rainfall. Flooding is possible for outback areas with some communities possible cut off for a length of time this week. Rain will ease during Wednesday. Rainfall should ease for the tropical coast by tomorrow night.

Severe Weather - Flood Risk SA

Heavy rainfall may develop tonight over the outback of SA and extend from a line near Tarcoola through Port Augusta and east to about Yunta. Some areas could see 150mm with thunderstorms.

Severe Weather - Flash Flooding NSW

Heavy rainfall likely to redevelop on the front of a rain band over western NSW through the day with some areas likely to see 50-100mm in quick time under thunderstorms. The severe weather risk from flash flooding will stop short of moving further east at this time thanks to ridging and ease over the west by Wednesday.

Severe Weather - Damaging Winds WA

Damaging winds and the chance of small hail with thunderstorms tonight over the SWLD and likely to continue into Tuesday with yet another front passing through the region. Some winds could reach 100km/h.

SHORT TERM CLIMATE DRIVERS

SOUTHERN ANNULAR MODE - Currently neutral and turning negative briefly, however likely to remain neutral overall during the first week of May. This may assist in more westerly winds developing over southern parts of the nation. This may also allow the jet stream to become a little more wavy and spreading the moisture south and east from the tropical north. If we can get moisture over the Eastern Indian Ocean, this may support more widespread rainfall across the country again.

THUNDERSTORM FORECAST

Thunderstorm Forecast Tuesday

Thunderstorms are forecast to contract slowly east as a trough begins to move into the eastern inland. Severe thunderstorms are likely to be further north now as the timing of a front looks to knock out the most potent humidity and combination of atmospheric dynamics further north into northern NSW and western QLD. Heavy rainfall and damaging winds are likely. Over the north, late season rainfall continues via scattered storms, more widespread over the northeast tropics. Another front could bring gusty storms to the southwest of WA with small hail.

Thunderstorm Forecast Wednesday

Thunderstorms will continue through the western parts of QLD extending northwards to the northern tropics and southwards into northern NSW clipping NE SA. Thunderstorms may turn severe with heavy rainfall and damaging winds the main concern.

Thunderstorm Forecast Thursday

Thunderstorm are forecast to continue along a trough over the eastern inland of the nation leading to widespread rainfall as well. Thunderstorms are forecast to be gusty with damaging winds about. Heavy rainfall may also lead to flash flooding. Thunderstorms are forecast to be active over northern areas of the nation with dry season starting out humid and wet for some.

Thunderstorm Forecast Friday

The front and trough from the Bight will add supportive wind fields and atmospheric dynamics to produce scattered storms over a wide area of the east with moisture lingering from the current event being lifted by a wave of unstable weather moving east. A dry line may establish through the inland and could be the focus of strong storms with damaging winds and heavy rainfall leading to flash flooding.

Thunderstorm Forecast Saturday

A dry line will continue to move through the interior of the country with a band of rain and thunderstorms moving north and east through the eastern inland. Storms could be severe if there is sufficient surface based instability but most storms should be elevated and gusty with moderate to heavy rainfall possible. Storms will continue over the northern tropics mainly during the afternoon and evening.

MEDIUM TERM - May 3rd - 10th 2022

Rainfall Anomalies

Rainfall may linger over the northeast of the nation with a stationary area of moisture being drawn through the jet stream from the Arafura Sea and driven over the NT into QLD with a trough of low pressure leading to scattered showers and thunderstorms at times, continuing the above average rainfall potential. Another impulse of moisture still a better than 50% chance of occurring from the Indian Ocean and passing through the jet stream to the southeast over WA through the period. Indications we may have another upper system to deal with over the central parts of the country starting out in SA and then shifting to the southeast. How much moisture can be drawn into this remains to be seen and timing is an issue.

Temperature Anomalies

Temperatures should start to improve after a cooler end to April for many over the inland and a cool start to May. A front and new wave of low pressure with a jet stream could bring in some warmer air through the central interior and across to the southeast and eastern inland at the end of this week, but the cooler days will linger in advance. So there may be a lot of blue on the board but improving temperatures are likely from about the 3rd onwards for large parts of the east, cooler for the west, but there are some timing issues bringing the next wave of cooler and wetter weather across the southeast and south of the country from the west, which will mean that the temperature outlook away from the north and eastern inland is somewhat low confidence.

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

A fairly dynamic pattern at the moment for QLD, NSW, SA and VIC with a series of troughs and deep moisture setting up to produce widespread rainfall with heavy falls possible from time to time leading to above average rainfall. The weather over in WA also fairly busy with a few fronts to get through over the course of the next 2 weeks. Some evidence the coldest weather of the year is likely for the SWLD in coming days and will watch the frost risk later this week. The frontal weather from the west will spill east and gradually clear out the humidity from southern areas but there is not a sufficient surge of southerly winds behind the front so remaining humid and unsettled over the north with above average temperatures and rainfall. This will play out once again to produce more rainfall events into May across the country.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Humidity values are elevated leading to widespread cloud, rainfall and thunderstorm activity, once again well above the norm for this time of year. Some drier colder weather across the southwest of the nation will run across southern Australia but the drier air will struggle to move northwards so more above average humidity to kick off dry season and sadly it is not looking like a great dry season this year for the north. This certainly suggests that with more build down weather for the next fortnight. But all that moisture could come into play across the central and eastern areas of 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 GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis and the state by state fly around with further context to just this data as a pretty picture.

More coming up from 8am EST Tuesday with a look at the Climate for the next 6 weeks and back to your state based forecast analysis tomorrow afternoon plus much more. Thanks for your patience over the past week.


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