Severe thunderstorms are flaring up in the Kimberley and Top End as the build-up to the monsoon ramps up.

The build-up season is an unofficial season that generally runs between September and December in northern Australia. It is characterised by hot temperatures and building humidity. As the build-up continues, thunderstorms (especially in the afternoon) become a more regular occurrence. This activity reaches a peak just before the monsoon arrives, which brings heavy rain, storms, cooler temperatures and an increased chance of tropical cyclones.

Image: Thunderstorms over northern Australia on Thursday, shown by the Weatherzone Total Lightning Network (WZTLN) and Weatherzone Oracle.

Build-up thunderstorms are sparking up over northern Australia this week, with some of these storms being severe, producing damaging winds and heavy rain. On Thursday, there had already been over 250,000 strikes recorded over the Top End and Kimberley as of 4pm ACST, with plenty of strikes still occurring nto the evening.

Image: Lightning strikes detected within 800km of Lake Argyle up to 4pm ACST on Thursday, November 17, from the Weatherzone Total Lightning Network (WZTLN).

The coming week will see regular scattered-to-widespread thunderstorms occurring over the north each afternoon, with more thunderstorms also forming overnights and in the mornings. Some of these storms will likely be severe with damaging wind gusts and heavy rain possible. You can find the active warnings on the Weatherzone website and mobile App.

Over the next fortnight, thunderstorms look to become more of a regular occurrence over the coast just north of Australia as well. This is a tell-tale sign that the monsoon is not too far off and may be building early in December. During La Niña years, the monsoon tends to arrive earlier than usual, typially in mid-December.

Image: Rainfall expected over the next week from the ECMWF model.