Radio man here !
Modern Wx Radar runs quite low peak power typically 150w Peak, this compares with older radars which ran power in the order of Kilowatts Peak. Conversly using modern receiver technology the have sensitivities up to 10Db better than older receivers, so the power budget remains broadly similar. While, correctly, an older radar was best given a wide berth when operating on the ground, modern radars are much more approachable as the average power, taking into account the Pulse Repetition Frequency is quite low. However the close in object / big reflection hazard to the equipment remains.
There a couple of rules of thumb to enable you to determine the power catagory of equipment fitted to your a/c.
1. Colour display - nearly always low power.
2. Monochrome display - usually old enough to be high power.
3. Observe your Avionics man getting a TR out of his van - just picking up a unit with no great effort - low power, about to get a hernia - high power.
And finally from the A330 AMM
WARNING: OBEY THESE SAFETY PRECAUTIONS WHEN THE WEATHER RADAR IS IN OPERATION. MAKE SURE THAT:
- ALL PERSONS ARE MORE THAN 5 METERS (16.4 FT) FROM THE ANTENNA.
- NO PERSON IS IN THE AREA MADE BY AN ARC OF 135 DEG. ON EACH SIDE OF THE AIRCRAFT CENTERLINE.
- THERE IS A MINIMUM SAFETY DISTANCE OF 60 METERS (200FT) BETWEEN THE ANTENNA AND ALL REFUELING OPERATIONS.
- THERE IS A MINIMUM SAFETY DISTANCE OF 5 METERS (16.4 FT) BETWEEN THE AIRCRAFT AND ANY OBSTACLE IN THE AREA MADE BY AN ARC OF 90 ON EACH SIDE OF THE AIRCRAFT CENTERLINE