I see squalls on my B&G 4G radar
using the regular settings (sea clutter: offshore
; gain: auto; rain: off). I find the auto settings work
far better than on other radars I've had, and rarely use the manual controls.
If that doesn't work
for you, however, turn the gain up and sea clutter down.
You will never see them as well as you could on a 4kW pulse radar, however -- nature of the beast.