A ray or streamer of cloud emerging from a cumulonimbus

In the November 1950 edition of Weather there were two letters, one from myself and one from Mr R. E. Lacy, describing a most unusual meteorological phenomenon we had independently witnessed. Briefly, from a cumulonimbus cloud was seen to emerge a ray or streamer of cloud, which after a minute or two would suddenly disappear or flick to another direction, presumably coincident with a lightning discharge within the cloud. This display was repeatedly visible in the bright afternoon sun for about half an hour, when the cloud finally became too distant to observe. Now, 62 years later, I would very much like to know if there have been other sightings of such a display, and whether an explanation of the atmospheric processes involved has been found. I thought it could be useful to have some sort of visual record, so I have added to a -photograph of a -cumulonimbus a simulation of how I visually remember the ray (Figure 1).

Figure 1.

Artistic impression of a ray from the top of a photograph of a cumulonimbus.

  • Rodney Hale

  • Houghton Conquest, Beds