A monsoon trough lies east-to-west across the Arafura Sea, with two embedded lows.

One low just south of Timor and another over the Torres Strait.

A monsoon surge is pushing through central Indonesia and will reach the monsoon trough today.

This surge will then push the trough southward toward the Top End Coast, the Bureau of Meteorology said this afternoon.

The late onset of the monsoon is not unusual with the latest onset occurring on January 25 in 1973.

The Timor low is rated a low chance of developing into a tropical cyclone on Tuesday .

It is expected to drift toward the southwest, away from the NT and pass into the Western Region on Wednesday.

In the short-term, the southward movement of the low will encourage monsoonal flow onto the Top End.

More stories:

Video of fast moving Katherine River closing low-level.

A large degree of uncertainty exists with the movement and development of the Torres Strait low.

The overall tropical cyclone risk will remain elevated with the monsoon trough remaining in the region.

A high to very high chance of rain and monsoonal squalls over the northern Top End late this evening and tomorrow, the bureau says.

The monsoon trough will move south and persist over the Top End. Dropping back to medium to high chance of rain and storms from Wednesday.

Over the next three days, the monsoon burst is expected to deliver rainfall of 80-100mm to the northern Top End, with isolated, heavier falls of 150mm along the north-western coastal fringe, including Darwin.

The short-lived monsoon burst is expected to weaken by the end of the week. Restrengthening is dependent on the development and movement of lows along the trough.40s for the next week.

While you're with us, you can now receive updates straight to your inbox each Friday at 6am from the Katherine Times. To make sure you're up to date with all the news, sign up here.