No frame at this minute
Rain intensity
lightheavy
Reading the strip
- Observed
- Radar, mirrored every five minutes. Where a prediction covers the same minute, the radar wins.
- Predicted
- Five-minute steps to two hours ahead.
- Predicted, coarse
- Half-hour steps to four hours. The model thins out here, and so does the strip.
Bar height is how much of the frame is wet; bar colour is how heavy that rain gets. The baseline goes dashed at now.
This forecast
- Anchor
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- Made
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- Run
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- Grid
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The anchor is the newest radar frame with a complete hour of history behind it — the last thing the model saw, and the picture at 0 min.
How the prediction is made
A neural network watches the last hour of radar — the close view over Singapore, and a wider one that catches storms still out at sea — and draws where the rain goes next. It learnt by being shown a long run of past radar alongside what actually happened after it.
What comes out is a probability, not a promise. Close in it is nearly certain, because five minutes from now the sky looks much like it does now. Further out it hedges, and the picture spreads and softens — that is the model admitting what it cannot know rather than a fault in the drawing. Past about ninety minutes, read it as where rain is likely, not how hard it will fall on one street.
It stops at four hours because that is where it stops being worth anything. Against simply knowing what the weather usually does at this hour, it is about 8% better one hour out and 6% better at four. By six hours the gain is nothing at all: the radar says no more than the clock already did.
Radar data from Singapore's National Environment Agency. NEA is not associated with this site and does not endorse it. The predictions are ours, made by a model — they can be wrong, so do not treat them as fact. NEA publishes the official forecast. All times SGT.