A brief but damaging storm in central Darwin and Palmerston on Monday that ripped a roof off a building was not strong enough to reach the "severe" threshold and prompt a thunderstorm warning, the Bureau of Meteorology said.
The wild storm brought down trees and powerlines, and tore the roof off a building near the Duck Pond mooring basin near the city's CBD about 4:00pm.
On Facebook, residents wondered why they got no warning.
"Anyone get a storm warning? I'm confused as to why I got a storm warning for the non-event the night before and not for the mini cyclone that nearly pushed my car over ??" posted Nina Ashley Bragg.
The BOM said radar imagery suggested wind gusts did not reach the "severe" threshold.
"Our threshold for damaging winds is 90 kilometres per hour and yesterday's storm only saw 76kph in any of our observation stations," meteorologist Laura Boekel said.
She said a microburst — a strong downdraft within a storm cell — probably contributed to the destructive storm.
"Sometimes in a thunderstorm situation we can see microbursts, which are really quite fast strong wind gusts that push through out of storms," Ms Boekel said.
"They're very hard to detect on radars, and if we don't have an observation in the area they usually go undetected."
'Short-lived' monsoonal burst for the weekend
Ms Boekel said Top End residents could expect to see a short-lived monsoonal burst later this week, with rainfall totals of between 50 to 10 millimetres forecast from Friday.
"There's currently a monsoon trough that's sitting to our north, it's quite weak at the moment and quite far away," Ms Boekel said.
"But as we move towards the weekend it's going to strengthen and it's going to move towards our Top End coast which means we will see conditions such as cloudy skies, cooler temperatures and that monsoon rain."
January is typically the wettest month of the year for Darwin, with 424mm of rain.
However, this month to Tuesday only 121mm had fallen, according to the BOM.
In Alice Springs, the bureau expected a low-intensity heat wave would return to the region later this week, with daytime temperatures set to peak over 40 degrees Celsius.ABC