CHENNAI: Chennaiites, please calm down! Kasimedu Harbour was not attacked by a twister, and no, there’s no threat of a hurricane! What you saw in the video (that has been going viral since October 27) was a waterspout, says the post on Tamilnadu Weather Man Pradeep John’s Facebook page. Here are few highlights:
Tornado and watersprout
- A tornado occurs over land while a waterspout occurs over water. Both have a rapid rotation of air and hence they are both classified as tornadoes; so a waterspout is a type of tornado.
- Waterspouts don’t need a powerful storm to create them. They thrive on warm, moist air above water, especially when there is little wind shear, and when air above the clouds is cooler than average.
- Waterspouts tends to be weaker. The force of friction is weaker over water; there is less air available to be drawn into circulation. Fair weather waterspouts & Tornadic waterspouts, are two categories.
- Tornadic waterspouts form over water or move from land to water. They are severe thunderstorms and are often accompanied by high winds and seas, large hails and frequent dangerous lightning.
- Fair weather waterspouts usually form along a line of developing cumulus clouds. This is generally not associated with thunderstorms.
- A fair weather waterspout develops on the surface of the water and works its way upward. It forms in light wind conditions, and move very little.
What was seen in Kasimedu ?
The morning of October 27 saw intense cloud bands (though not big) move into sea around 8.30 am in north Chennai sea side. People spotted a funnel cloud (which does not touch land or water) and slowly the leg of the cloud climbed down and touched the water. The video clearly shows the leg of the waterspout visible in the sea. Yes, it was a waterspout and since dense clouds were seen during the period.
He also clears that watersprouts have a lifecyle of 20 minutes and urges people not to believe in rumours that a tornado is going to attack Chennai.
For more details, visit the page — Tamilnadu Weather Man — on Facebook