If ever you felt uncertain about the sheer power of thunderstorms, this gorgeous video of a gigantic forming supercell over Wyoming should convince you otherwise.
The timelapse of the storm as it formed over Wyoming yesterday May 18,2014), which you can see below, was made by Basehunter Chasing, who also tweeted the image of the supercell above.
WHAT IS A SUPERCELL THUNDERSTORM?
Supercell thunderstorms are a special kind of single cell thunderstorm that can persist for many hours.
They are responsible for nearly all of the significant tornadoes produced in the U.S. and for most of the hailstones larger than golf ball size. Supercells are also known to produce extreme winds and flash flooding.
Supercells are highly organized storms characterized updrafts that can attain speeds over 100 miles per hour, able to produce extremely large hail and strong and/or violent tornadoes, downdrafts that can produce damaging outflow winds in excess of 100 mph – all of which pose a high threat to life and property.
Dynamically, all supercells are fundamentally similar. However, they often appear quite different visually from one storm to another depending on the amount of precipitation accompanying the storm and whether precipitation falls adjacent to, or is removed from, the storm”s updraft.
Based on their visual appearance, supercells are often divided into three groups;
- Rear Flank Supercell – Low precipitation (LP),
- Classic (CL), or
- Front Flank Supercell – High precipitation (HP).
In LP supercells the updraft is on the rear flank of the storm, a barber pole or corkscrew appearance of updraft is possible, precipitation sparse or well removed from the updraft, often is transparent and you can”t see it, and large hail is often difficult to discern visually. Also, there is no “hook” seen on Doppler radar.
HP supercells will have…
- the updraft on the front flank of the storm
- precipitation that almost surrounds updraft at times
- the likelihood of a wall cloud (but it may be obscured by the heavy precipitation)
- tornadoes that are potentially wrapped by rain (and therefore difficult to see), and
- extremely heavy precipitation with flash flooding.
Beneath the supercell, the rotation of the storm is often visible as well. The wall cloud is sometimes a precursor to a tornado. If a tornado were to form, it would usually do so within the wall cloud.
Wall clouds are isolated lower clouds below the rain-free base and below the main storm tower. Wall clouds are often located on the trailing flank of a storm. With some storms, such as high precipitation supercells, the wall cloud area may be obscured by precipitation or located on the leading flank of the storm.
Wall clouds associated with potentially severe storms can:
- Be a persistent feature that lasts for 10 minutes or more
- Have visible rotation
- Appear with lots of rising or sinking motion within and around the wall cloud
Watch An Enormous Thunderstorm As It Forms: Supercell Time-Lapse.