QLD - RAIN CONTRACTING EASTWARDS, BECOMING HEAVY ALONG PARTS OF THE COAST BEFORE DRY WEATHER RESUMES

OVERVIEW

Rain and thunderstorms continue to feature along a surface trough this evening which is slowly edging eastwards through QLD driving the heavy anomalous rainfall we have been experiencing for the past 3 days. It is expected to become more widespread as we track into the new week as the trough deepens and stalls along the coast with an upper feature over the inland, all of which is combining to produce this wild weather.


The cold and rainy weather will subside by late Tuesday along the coast, inland areas should tend dry but remain well below average for now the remainder of the week.


The drier weather will impact the coast from late this week into the weekend and finally some more typical Winter weather will develop and dry season resume for the north.


SHORT TERM

Severe weather impacts are the main issue to deal with between Mackay and the Sunshine Coast with areas being clobbered by heavy rainfall and flash flooding, reaching near record rainfall totals for some locations by the time we get to Tuesday. All of the major rainfall should be out the door Wednesday which the inland is mostly dry from now into the following weekend at this stage.


With higher pressure moving in, the focus of the weather returns to the south and west of the nation as a northwest flow develops leading to that settled spell of weather which will be welcome for many.


There are low signals for the return of cloud and rainfall ahead of cold fronts in the medium term, the models just suggesting that the moisture profile may remain above average but the high pressure being close by leading to stable weather.


LONG TERM

The pattern looks relatively benign across modelling with no strong pull towards severe weather or anomalous weather, frontal weather developing through a westerly wind belt sitting at about seasonal latitudes will see rainfall reflect that, mainly over the southeast and southwest of the country, wettest weather at this time over the SWLD and Western Tasmania.


Drier weather developing over the north and east at this time, though the moisture profile is still elevated to the north of the nation. The big feature over the coming 1-2 weeks will be the below average temperatures for the country. The cooler weather helping to bring about a more stable nation with a lower ability for instability values to rise to produce severe weather.


But as always things can change quickly, and you will hear about it here first.


AREAS TO WATCH

Certainly, the SAM being in a negative state would be beneficial for southern areas to see rainfall return and eastern and northern areas of the nation to give up that anomalous rainfall and return to the dry season that many long for at this time of year. At this time a neutral SAM looks likely through mid-month.


Therefore, the focus of the weather will be on the westerly wind belt and the greater influence over the country’s south and southwest.


Other area to watch, the Indian Ocean, how much moisture can return into the medium term to override the drier air that continues to sit under high pressure through the Indian Ocean and over northwest WA. Once that activates again with moisture then it is game on for better rainfall prospects for large parts of Southern Australia.


WEATHER VIDEO PM - SUNDAY 3RD JULY 2020

FORECAST

Rainfall Next 10 Days

Rainfall is forecast to increase once again over northern and eastern QLD with an upper trough approaching and tapping into that deep moisture profile which will lead to widespread above average rainfall after a short break today. The rainfall heavy and could lead to further flooding as mentioned above. The rain will clear eastwards during Tuesday and clear by Wednesday and then essentially it is a dry run for the inland through mid-month. Showers may return to the coast at times but nothing on the level we have seen in recent days.

Could be a little on the high side on the coastal fringe between Mackay and Bundaberg, but with some of the models not handling the NSW event right in the past few days and bringing higher falls that forecast anywhere, there is the chance we could see rainfall up over 200mm for the period for some, but this is a moderate risk. Be weather aware. Rain clears inland during Monday afternoon.

SEVERE WEATHER WATCH - QLD - UNCHANGED GUIDE FROM SATURDAY FOR THE REMAINDER OF THE PERIOD.

Heavy rainfall has been observed in the past 72hrs and more is to come with a secondary burst of severe weather likely to develop with a heavy rain band along the coast with heavy falls leading to flash flooding over the course of Sunday night through Tuesday night. Areas of rainfall over the inland will also cease with the focus of severe weather likely along the coast for now between Mackay and Sunshine Coast. Conditions ease by mid-week as the whole complex moves east. Some locations could see 100-200mm of rainfall.

FLASH FLOOD RISK - SUNDAY PM-TUESDAY PM - QLD

The second belt of heavy rainfall is expected to develop during the overnight hours and peak on Monday before easing during Tuesday with some locations seeing 30-50mm/hr for a number of hours along the Central and Capricornia coasts. Some areas could see high impact flash flooding if we see the trough stall longer through the one portion of the coast than is currently advertised. The severe weather risks ease by Wednesday

RIVERINE FLOOD RISK - NEXT WEEK - QLD

Minor flooding is expected to develop with the heavy areas of rainfall through the coming 24hrs along sections of the coast. If the rainfall exceeds the forecast which there is a moderate chance it does, then we could see moderate flooding developing. The flood threat is not at the same levels as we saw with the Autumn events.

MEDIUM TERM

July 10th-17th 2022

Rainfall Anomalies

Still not seeing any strong signals for heavy rainfall across the nation at this but the wetter bias continues over in the east possibly, with the SAM staying relatively neutral, possibly a little more positive than neutral, which is giving off that weak easterly flow for NSW and QLD keeping some showers in the region but also knocking down the westerly wind belt and stopping major rainfall events from unfolding through mid-month over southern Australia. Frontal weather yes, widespread heavy rainfall, not yet. Drier weather up north with the MJO moving back away from the region.

Temperature Anomalies

Still have this very robust cooler signal for the northern parts of the nation and this extends through the central interior and into the eastern parts of the country. The southern and southeast of the nation is forecast to see relatively seasonal weather with high pressure over the region and this may spread back over southern Australia into WA.

DATA - Refer to the video for further information.


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

Refer to the video for further information but the severe weather risks are set to ease over the coming 2-3 days then we wait to see how the atmosphere responds and how the modelling reacts to that.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The very deep moisture plume is heading east, and we can see it taking its time, lingering through to the north of the nation but also to the east of the country thanks to the low near NZ. Widespread dry air over the western, northwestern and central parts of the country will continue for a while longer suppressing rainfall throughout the country. The weather over the southeast and southwest may start to pick up the northern flank of cold fronts leading to some showers about the coastal areas of the south. In the medium term, the moisture does start to move eastwards across the country via a more traditional pattern. Also note the moisture deepening northwest of Australia in around 2 weeks from now and that will be the feature to watch for the nation in relation to rainfall returning in the back half of the month.

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 - the bulk of the rainfall shown here falls over the coming 48hrs. There may be some rainfall that comes back from about the 11th onwards, but it is unclear on coverage and placement, it may indeed fall further south or out to sea, but the higher confidence is in the rain event over the coming 48hrs.

More coming up from 8pm EST with a look at the models and rainfall - what is beyond the flooding in the east, and does the dry spell roll on further south and west?



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