Strange Cloud formations showing on Rain Radar

[Cameo1]

Hey, just wondering what you guys make of the two strange, still and unchanging cloud formations off the east coast of northland. They show up when using the time lapse New Zealand rain radar.

[Manukau heads obs]

often its rain that is actauly over the horizon
and the rain radar picks it up because of inversion layers bending the signal

[Cameo1]

often its rain that is actauly over the horizon
and the rain radar picks it up because of inversion layers bending the signal

Wow, oh ok, thanks. Do you think that has an effect on the accuracy of the rain radar a lot of the time?

[Manukau heads obs]

i think the rain warnings might get cancelled
most of the heavy rain/frontal activity is slipping south in the tasman to the west of the upper NI
what do others think?
besides the air is too cold, dew point is olnly 8 oC, for heavy rain like the met service have been talking about
(at least with this warm front, the cold front might be a different story)

[Manukau heads obs]

met service have lowered the heavy rain amounts
(saying the front is moving faster)

[Weather Watcher]

Hey, just wondering what you guys make of the two strange, still and unchanging cloud formations off the east coast of northland. They show up when using the time lapse New Zealand rain radar.

I think the echoes that Cameo1 is referring to are the sea clutter echoes over the Hauraki Gulf. These occur during strong northeasterly conditions when there is a reasonable sea chop. Although the main radar beam is above the surface, there are weak side lobes on the beam which impinge onto the sea surface. When there is no other significant weather around, this sea clutter dominates the radar returns, and only occurs in windy conditions. It is the same as is often seen on the Wellington radar around Cook Strait. Unfortunately it is difficult to remove these echoes effectively from the 300km range radar scans which make up the NZ composite.