The wet season has cranked up finally for FNQ, some towns down the Bruce still missing out, ie Townsville and Bowen etc. But the wet weather finally has brought relief to the very high temperatures over the northern regions.

The humidity over the remainder of the state, still very high and with troughs about, but little dynamic forcing, a smattering of showers and thunderstorms today will be repeated again and again this week. The onshore winds along the coast between Tiffany to the north and the high to the southeast also producing showers along parts of the coast.

It is summer time in QLD.

Looking further ahead and an upper disturbance is expected to pass through later this week into the weekend, and that will allow the atmosphere to destablise further resulting in more widespread showers and thunderstorms, with severe weather returning to the mix. Storms will carry the risk of heavy rainfall, damaging winds and large hail.

The moisture from the remains of Tiffany, may recirculate around the nation and come back via upper level northwest winds into the medium term bringing up rainfall chances. But areas around the Gulf need to pay attention to forecasts and warnings over the coming days as this system may produce significant rainfall if it adopts a more southern track.

Lets take a look


Rainfall Next 10 Days

Extensive rainfall is ongoing through parts of FNQ today with Tiffany passing by. Some areas have recorded over 200mm so far and another 200mm is likely before she leaves, with the backwash northerly flow to come tonight and tomorrow, before winds turn wet northwesterly for parts of the west coast of Cape York. The remainder of the state, the routine showers and storms continue, some heavy with gusty winds in the coming days. It will be over the weekend that the rainfall coverage for southern and eastern QLD increases as the upper trough passes through. Further to the northwest, we may start to see rain develop as the moisture from Tiffany is brought back into the state but this is dependent upon track. Onshore winds will continue for much of this period so showers with moderate falls for the coast.

Tropical Cyclone Tiffany

The cyclone has crossed over Cape York today and will move steadily west, losing some strength as it passes over land, losing it's source for maintaining strength, but once back over the open waters of the Gulf, she is likely to strengthen rapidly into a Cat 2 and then a major Cat 3 by Wednesday before approaching Groote Eylandt by Wednesday afternoon as a high end Cat 3 before crossing the mainland shortly there after at similar strength. The system will then wash out over land and dump a tremendous amount of rainfall, turning the system from a wind and rain event on the coast to a major flood risk over the Top End.

Flood Risk This Week.

I cannot tell you how concerned I am about the flood risk for the Top End, but it is very high. So if you know anyone living along the river systems mentioned please let them know to prepare now!

Thunderstorm Forecast Tuesday

Thunderstorms are expected to increase over the Top End on Tuesday with the approach of the TC through the Gulf. Converging airmass with a rotating bands of energy around the system will help flare up thunderstorms. A strong line of thunderstorms is likely to develop out over Arnhem Land and sweep west through the Top End. A squall line making the Daly later in the day if not into Wednesday depending on the speed of Tiffany.

Damaging Winds Risk Tuesday

Damaging winds with thunderstorms a moderate to high risk across the eastern Top End and throughout the Gulf Country.

DATA - More details on the GFS and CMC guide in the video.

00Z GFS -Surface Pressure Pattern and Rainfall Distribution - Next 16 Days

This is a low confidence forecast as we work out where the steering currents take Tiffany and ultimately that will drive the weather nationally as mentioned throughout the day.

00Z GFS - Precipitable Water Values - Next 16 Days

The deep moisture profile is something that all models have in place but the difficulty will be in teaming the deep moisture with adequate areas of low pressure, where does the tropical system go? Many of these parameters need to be answered before your rainfall and temperature forecasts will carry more confidence. So keep that in mind.

00Z GFS - Rainfall Accumulation - Next 10 Days

More details can be found in the video.

00Z CMC - Rainfall Accumulation - Next 10 Days

This is the more plausible solution and more details can be found in the video.

00Z GFS - Rainfall Accumulation - Next 16 Days

I am leaning away from this solution, but note that this will change a lot in the coming days and your number will change constantly. The drier areas will be the west and south, the wetter areas will be north and east.

A closer look in - note that I am siding with other models, but this gives you an idea of what is on the table as we move through the remainder of the month.

More details coming up tonight on all things models and rainfall from about 9pm EDT.

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