Rainstorm and lightning lashed the city over Monday early morning

Unstable weather is expected to linger over the next two days as heavy rain pours across the city with the Red Rainstorm Warning Signal and the Thunderstorm Warning now in force.

This as the city saw intense downpour overnight.

The area of severe thunderstorm, associated with a broad low-pressure trough and active southwest airflow, developed rapidly over Hong Kong in the early morning, ushering in heavy showers and thunderstorms.

At 12:45am, the Observatory issued an amber rainstorm warning signal. Half an hour later, it's raised to the red rainstorm warning signal. Precipitation was generally around 60mm across districts.

Kowloon East was lashed even harder with cumulative rainfall topping 100mm. While the rainstorm warning signal was hoisted, the observatory recorded about 1,000 cloud-to-ground lightning strikes.

As the rain bands moved away from the city, the rainstorm warning signal was downgraded to amber at 3:50am.

By 5am, all rainstorm warnings were cancelled. The forecaster reminds the unstable weather is here to stay over the next two days. The observatory's scientific officer says a broad trough of low pressure and active southwesterly airstreams are expected to continue affecting the South China coast on Monday and Tuesday.

For the remainder of the day until Tuesday morning, Hong Kong's weather will remain unsettled, with occasional showers, violent thunderstorms, and heavy downpours.

Showers are expected to ease off mid-week.

But because of the influence of southerly airstreams, the unstable weather will be back over the weekend through early next week.