Story

The Beginning

This began with my long-time curiosity on how to convert raster radar images into vector on a map. I've been using Weather.gov.sg's Rain Areas map whenever it rains, so I thought if I could convert that raster image to be used on Mapbox GL JS. I could put the whole raster image on Mapbox but choose to make it vector because I like it smoother.

After few trials and errors, I cooked up the Rain GeoJSON SG project, a straight-forward API server to convert rain area radar images (Singapore) to GeoJSON.

Since I've gone this far, so I thought "why not?", let's build yet another weather app for Singapore! Thus this project just happens.

👉 Read more: Building Check Weather SG.

The lock-down period

2 years later (2020), I revisited this project and rebuilt it:

• ⏳ Past 2 hours of radar snapshots
• 🧼 Cleaner UI
• 🗺 Cleaner maps
• 🌏 Remove the 3D mode (it's not useful)

I've also built an 📱 iOS app.

And... a plethora of open-source projects to make the impossible possible:

• ☔️ rain-geojson-sg - the core API to fetch weather observations and rain radar
• ⏰ checkweather-sg-checker - a scheduled serverless function to keep checking for rain
• ⛱ sg-coverage - a script that converts the Singapore boundary into a 217x120 array of indices with values indicating its (land) region excluding the surrounding areas (other countries and water).
• 📸 rainshot - a serverless instance to capture rain radar images
• 🍩 rainshot-checker - A site to experiment contouring the radar data
• 📤 sg-rain-radar-scribbler - another site to load rain radar image and generates a JSON output similar to the one generated by rain-geojson-sg.

Rain notifications

There are currently 3 channels:

1. Push notifications, via the iOS app.
2. Twitter @checkweathersg
3. Mastodon @[email protected]
4. Telegram channel /checkweathersg

Technicalities

Node.js is required to run this web app. Here's a list of readily-provided scripts:

• npm start - starts a local server for development
• npm run build - build the files for production in dist folder
• npm run serve - starts a local server to preview production build

Copyright, license & credits

• Data © Data.gov.sg © Meteorological Service Singapore © National Environment Agency
• Code licensed under MIT
• Weather icons from Meteorological Service Singapore
• Fire icon from Noto Color Emoji