Central Singapore
Central Water Catchment weather
Forested catchment around MacRitchie, Upper and Lower Peirce, and Upper Seletar.
How rain usually arrives here
The catchment is where many inland storms first light up on radar. Forest cover cuts the urban heat island, so nights run cooler than the city. If you are on the trails, treat thunder as a reason to leave the ridge, not a reason to wait and see.
After lunch in April, May, October and November, use the 2-hour nowcast and the 50 km radar together. The island 24-hour line is too coarse.
Central Singapore
Central towns sit on the inland heating plateau and against the catchment. Inter-monsoon afternoons are thunderstorm country. A stalled red cell over Toa Payoh or Bishan is the usual flash-flood setup.