Millions of bogong moths trigger rain warnings on weather maps

Key points

• Weather radars across south-eastern Australia have shown rain-like signals most nights for a month, though skies are mostly clear. The Bureau of Meteorology says millions of bogong moths migrating to the Australian Alps for summer are the likely cause.
• The insects take flight after sunset and appear on radar as widespread light rain. Radar echoes have spread from New South Wales into northern and eastern Victoria.
• Standard forecasts are not affected, as they rely on modelling, ground observations and satellites. Some weather apps relying on raw radar data could send false alerts.