The weather is set to turn more humid and unsettled from the north as the tropics are set to revisit through the southern and eastern parts of the nation. The theme of Summer thus far.

A nice break from the humidity over southeast areas is set to continue for another 2 days before the temperatures rise once again and we see a more humid east to northeast flow redevelop.

For the moment, the unsettled weather will remain in QLD and the NT, plus a lot of northern SA and eastern WA with Tiffany, the high pressure ridge over the Bight is expected to sit further north, bumping the moisture out of the Ag areas of SA and much of southern NSW and VIC.

Once the high over the south moves into the Tasman Sea and the flow turns more northeasterly, this will introduce the moisture over NSW and QLD back into VIC and SA with unsettled weather developing. The showers and thunderstorms main commence as early as Thursday into Friday, before broadening and with a low forming within the trough to produce widespread falls into the weekend. This could be a severe weather event and more guidance to come today.

For the northern tropics, the wet weather is set to continue with an increased risk of tropical depression formation north of the NT later this week into the weekend, that system also needing watching, with the moisture set to feed across the country ontop of what is already in place this week. Significant ingredients are in place for severe weather and further flooding in a widespread zone, but placing the highest risk remains tricky.

The far west remains dry for now, the Mediterranean Summer continues as expected.

Lets take a look.


Rainfall Next 10 Days

Rainfall remains heavy this morning over the southwest and western NT and across the northwest of SA where flood watches are in place. The rainfall expected to run across the north of SA this morning with patchier falls into the central areas of the state but dry weather further south, though cloudy. The rainfall and thunderstorm activity may move into the eastern inland of the nation, but bypass VIC and southern NSW and the ACT at this time, with heavier rainfall on the way with the remains of Tiffany through northern NSW and southern QLD. The tropics, showery with gusty storms and the west is dry. For the latter part of the week, the tropical moisture from Tiffany gets stuck over NSW and QLD in a broad easterly flow, and this moisture is likely to be propelled back west through NSW and QLD into SA and link up with a complex upper trough where showers and thunderstorms will increase once again. A severe weather event for SA, VIC, NSW and QLD may unfold in the weekend leading up to Australia Day with thunderstorms and areas of rain leading to flooding possible with this slow moving feature. Another severe weather event up north in the form of a tropical low delivering heavy rainfall and squalls may impact the NT or WA and help to transport the monsoonal flow into the northern parts of the nation adding more chances for rainfall beyond this period over large areas. The dry area for now is likely to be SWLD of WA but the moisture will be coming back.

Tropical Depression Watch - January 20-27th 2022

Another wave of low pressure is expected to form off the NT coast and move westbound into the Indian Ocean during this time. It will likely encounter better wind shear and form into another cyclone. How long it stays over water and its proximity to the coast will determine it's strength but some models ramp it up to a substantial system in the medium term. This is very typical following excessive heat values over the region for the past few weeks. This is the response to that.

Thunderstorm Forecast Monday

Thunderstorms will continue in a broad zone across the country with heavy rainfall leading to flash and riverine flooding the main issues out of this tropical incursion of moisture. Storms may be gusty close to the low pressure system as it passes through the interior of SA and NT before shifting into western QLD/NSW. Dangerous flash flooding is possible through outback areas between Alice Springs and Yulara. Gusty storms are also possible over the the Top End and Kimberly in a northwest monsoonal flow.

Thunderstorm Forecast Tuesday

Thunderstorms will continue in a broad risk across the northern and eastern parts of the nation with severe thunderstorms possible with heavy rainfall in a band from the NT through northern SA into western and central QLD and NSW. Dangerous flash flooding is possible through northeast SA and southwest QLD. Storms may be severe over the NT with damaging winds as well. The west coast of WA may also see a few showers and thunderstorms but severe weather is unlikely.

Thunderstorm Forecast Wednesday

Thunderstorms will continue along and to the east of a trough through the NT, stretching through QLD and into NSW with the remnants of Tiffany leading to deep moisture levels and the chance of heavy rainfall leading to flash flooding. Up north, the risk of damaging winds is possible in the NT and through outback areas. High based storms possible about a seabreeze front during Wednesday afternoon in the northwest of WA.

Flood Watch Interior and East.

The heavy rainfall is ongoing over northern areas of WA and is expected to move back into the Western NT and through northern SA with falls exceeding 100mm likely near the remnant circulation. Heavy rainfall will develop through Tuesday and Wednesday over the outback of SA and the eastern NT before heading into NSW and QLD and the falls likely easing in intensity by mid week. Thunderstorms will still carry the risk of flash flooding in these areas. Conditions dry out over the western portion of the watch area by mid week.

DATA - Refer to video for more information

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

There have been some readjustments in the movement of the remains of Tiffany in the short term, she is expected to adopt a more easterly track and like her performance over northern Australia, will move through quicker than what as advertised on models. The moisture will however get stuck over the eastern inland of the nation with widespread rainfall increasing from later this week and into the weekend, and likely to spread through SA and VIC as winds veer into the northeast, so more humid and unsettled conditions this week for the majority of NSW and QLD, then extending into VIC and SA later this week into the weekend. There may be severe weather issues on the weekend for SA and VIC with that sharp trough passing through. The monsoon may introduce itself over northern Australia over the weekend and this may support the next wave of rain and storms nationally beyond this period. A very deep moisture profile sets up over the north of the nation and heavy falls could develop for QLD and the NT. The west, well can't really buy a drop in the SWLD, but keeping an eye on the tropical lows that do form in the short and medium term.

12Z Euro - Precipitable Water Values - Next 10 Days

The moisture profile remains deep and unchanged from last night, the only changes you will note is in the distribution in relation to the low pressure across the nation. The models have agreed in the short term, that the moisture will likely stay north of the Ag areas of SA and VIC through the early part of this week thanks to high pressure but once the high moves into the Tasman Sea and the northeast to easterly flow develops across the nation, that will see rainfall chances increase for much of the south and east of the nation with the potential for very heavy moisture profile lingering from the weekend towards Australia Day. The monsoon may also be in place by later in the weekend into next week.

12Z Euro - Rainfall Accumulation - Next 10 Days

More information can be found in the video.

12Z GFS - Rainfall Accumulation - Next 10 Days

More information can be found in the video.

12Z CMC - Rainfall Accumulation - Next 10 Days

More information can be found in the video.

12Z Euro - Rainfall Accumulation - Next 15 Days

More information can be found in the video.

12Z GFS - Rainfall Accumulation - Next 16 Days

More information can be found in the video.

Looking at the medium term later this morning and the tropical weather impacts once again heading into Australia Day. The rainfall is expected to ramp up for the second half of this month, with areas of flooding already developing on cue.

154 views0 comments