Cloud Base
1. The Cloud Base is actually and consistently rotating (EVEN IF SLOWLY). Look at the bottom of the cloud base (or wall cloud) which normally would just be gliding along in the direction of the storm. Look at it long enough to see if there is ANY rotation while it glides. This indicates a mesocyclone in a thunderstorm and is one of the signs of a tornado forming.
Wall Cloud
2. A Wall Cloud, a large LOWERING cloud formation. Look for a lowering portion of the surrounding storm cloud base to what is called a wall cloud (pedestal cloud). It often happens suddenly and is the area of strongest updraft within a storm. This is a potential tornado sign.
Dust Debris
3. Whirling dust debris above the ground (similar to a ‘dust devil’ but bigger). If you notice this beneath a large storm cloud base, it may be a tornado sign that one may have already formed but is still up in the cloud. It’s strong updraft is pulling air up into it which is revealed by dust debris.
Sudden Stop | Eerily Quiet
4. Heavy rain and hail suddenly stops and it becomes eerily quiet. This may be a sign of an impending rain-wrapped tornado.
Intense Wind Shift
5. An intense wind shift after the dead-calm. This is a further sign.
Greenish – Black Sky
6. If the sky becomes a greenish black color it may be a tornado sign. The greenish hue is created from scattering of light combined with conditions within a extremely tall storm cloud, typically late in the day.
Very Large Hail
7. Hail (especially large golf ball size or larger). The storm’s updraft creates hail and is located right above the tornado, so very LARGE hail is a sign indicative of a possible tornado.
Continuous Sound
8. A loud continuous roar, rumble, waterfall sound, or sounds similar to a train or jet (which does not quickly fade out like thunder), may be a sign that a tornado is approaching. Tornadoes are LOUD. Some describe the sound as a simultaneous lower-pitched roar (train rumble) and a higher frequency “whine” (like a low flying jet).
Falling Debris
9. Debris falling from the sky may be a sign that a tornado has formed and has scoured objects from the ground – hurling them up to great distances.
Bright Ground Flashes (nighttime)
10. Signs of a tornado at night: If at night you see bright ground flashes near a thunderstorm (blue-green-white), it may be a sign that a tornado is blowing out power transformers and power lines there. Also, when lightning flashes, you may actually see the tornado.
Where should you go in your house during a tornado?
Underground
Preferably a purpose-designed storm shelter underground.
Otherwise, the basement. Think about what is over your head on the 1st-floor above. Don’t be underneath heavy objects in case the floor breaks. Wear a helmet to boost your survivability.
No Basement?
– Avoid windows. Go to the lowest floor, small center room (like a bathroom or closet), under a stairwell, or in an interior hallway with no windows.
– Crouch as low as possible to the floor, facing down; and cover your head with your hands.
– A bath tub may offer a shell of partial protection.
– Even in an interior room, you should cover yourself with some sort of thick padding (mattress, blankets, etc.), to protect against falling debris in case the roof and ceiling fail.
– A helmet can offer some protection against head injury.
