Moth Madness: Bogong Moths Wreak Havoc on Weather Radars
Millions of bogong moths migrating to the Australian Alps for summer are causing chaos for weather forecasters, as they are being mistaken for rain on weather radars across south-eastern Australia. The phenomenon has been ongoing for the past month, with weather radars lighting up with precipitation every night, despite clear skies and no rain.
A peculiar phenomenon has been causing a stir in weather forecasting across south-eastern Australia, as millions of bogong moths migrating to the Australian Alps for summer are being mistaken for rain on weather radars.
The issue has been ongoing for the past month, with weather radars lighting up with precipitation every night, despite clear skies and no rain. A spokesperson for the Bureau of Meteorology said, "There has been increased 'echoes' displaying on radars across eastern New South Wales that aren't precipitation."
What's causing the radar interference?
The radars are detecting the massive swarm of bogong moths, which appear as widespread rain on radar imagery. The insects migrate south in their millions, taking flight just after sunset and resting during the day. The false echoes are appearing like clockwork, with recent nights seeing the phenomenon across northern and eastern Victoria.
A radar works by sending out radio waves and waiting for the signal to bounce back off airborne particles. If the waves reflect off raindrops, hail, or snowflakes, the radar can construct a 3D picture of the precipitation pattern. However, other objects in the sky, such as bushfire smoke, aircraft, flocks of birds, and swarms of insects, can also result in a return signal.
How are meteorologists coping with the interference?
The Bureau of Meteorology spokesperson said, "Large numbers of insects can look like very light widespread rain, particularly near sunrise and sunset." While meteorologists are not normally fooled by radar interference, some weather apps may be sending false alarms due to their reliance on raw radar data.
The prolonged spell of interference has made radar interpretation less reliable, but standard weather forecasts remain unaffected, as they rely on weather modelling, ground observations, and satellites.