yasi is now a 5 - and it's huge., page-14

ok, can see it. it's a false colour image generated by measuring wind speeds or cloud density.

(a) these would likely be snapshots of vortices captured in temporary measurements. black might be the tiop end of the scale. momentary vortices of high intensity or very dense clouds.

or (b) otherwise it could be a patch of bad data indicating a dead spot of measurement.

it's false colour to indicate intensity. i'll go with (a) thank you eddie.