Every 2 minutes Window reads NEA's lightning detectors, rain radar and rain gauges around Tengah. 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 Tengah comes from NEA's West region monitors (24-hour PSI and 1-hour PM2.5). The nearest rain gauges are Old Choa Chu Kang Road (0.7 km) and Tengah Meteorological Station (1.4 km).
Alerts for Tengah on Telegram: @WindowSingaporeBot. A heads-up before storms and when haze turns unhealthy; nothing for maybes.