Every 2 minutes Window reads NEA's lightning detectors, rain radar and rain gauges around Sembawang. It tells you when a thunderstorm is closing in and roughly when it will arrive, when to stay indoors because lightning is within 10 km, and when rain is likely in the next two hours.
Haze for Sembawang comes from NEA's North region monitors (24-hour PSI and 1-hour PM2.5). The nearest rain gauges are Woodlands Drive 62 (1.7 km) and Sembawang Meteorological Station (2.3 km).
Alerts for Sembawang on Telegram: @WindowSingaporeBot. A heads-up before storms and when haze turns unhealthy; nothing for maybes.