Everyone knows about funnel clouds. But by the time you see one, there is no time left to prepare and seek shelter. The National Oceanic Atmospheric Administration Storm Prediction Center offers the following signs that a tornado may be imminent:
- Strong, persistent rotation in the cloud base.
- Sickly green or greenish-black sky.
- Whirling dust or debris on the ground under a cloud base. Sometimes a tornado has no funnel.
- Hail or heavy rain followed by dead calm or by a fast, intense shift in the wind. Many tornadoes are cloaked in heavy precipitation and can't be seen.
- Day or night: a loud, continuous roar or rumble that doesn't fade, as thunder does, within a few seconds. The roar has been compared to the sound of an oncoming jet or freight train.
- Night: small, bright, blue-green to white flashes at ground level near a thunderstorm (as opposed to silvery lightning up in the sky). Those flashes are caused by power lines being snapped by strong wind, such as a tornado.
- Night: persistent lowering of the cloud base, as illuminated or silhouetted by lightning — especially if the cloud base is on the ground or there is a blue-green-white power flash underneath.
If you are in an area subject to tornado activity, be sure to have your catastrophe planning complete, current and well-communicated to your family.
©2013 Selective Ins. Group, Inc. (Branchville, NJ). "Selective" insurers include Selective Ins. Co. of America, Selective Ins. Co. of New England, Selective Ins. Co. of N.Y., Selective Ins. Co. of South Carolina, Selective Ins. Co. of the Southeast, Selective Way Ins. Co., Selective Cas. Ins. Co, Selective Fire and Cas. Ins. Co and Selective Auto Ins. Co. of N.J. Insurers and products available vary by jurisdiction.