4:-Red Tides
Red tides are also known as algal blooms – sudden influxes of massive amounts of colored single-cell algae that can convert entire areas of an ocean or beach into a blood red color. While some of these can be relatively harmless, others can be harbingers of deadly toxins that cause the deaths of fish, birds and marine mammals. In some cases, even humans have been harmed by red tides though no human exposure are known to have been fatal. While they can be fatal, the constituent phytoplankton in ride tides are not harmful in small numbers.
5:- Ice Circles
While many see these apparently perfect ice circles as worthy of conspiracy theorizing, scientists generally accept that they are formed by eddies in the water that spin a sizable piece of ice in a circular motion. As a result of this rotation, other pieces of ice and flotsam wear relatively evenly at the edges of the ice until it slowly forms into an essentially ideal circle. Ice circles have been seen with diameters of over 500 feet and can also at times be found in clusters and groups at different sizes as shown above.
6:-Mammatus Clouds:-
True to their ominous appearance, mammatus clouds are often harbingers of a coming storm or other extreme weather system. Typically composed primarily of ice, they can extend for hundreds of miles in each direction and individual formations can remain visibly static for ten to fifteen minutes at a time. While they may appear foreboding they are merely the messengers – appearing around, before or even after severe weather.