Dangerous Oklahoma weather: 8 tornado/storm terms you need to know

Oklahomans aren’t strangers to severe spring weather, and last night’s swath of storms has everyone saying, “I love Oklahoma, but this weather…”
Enterprise reporter Julianna Keeping was watching last night’s news coverage and heard some weather-related terms she’s heard before but realized she didn’t have a clue what they meant.
Here are 8 weather-related terms you should know.
No. 8 – Mesocyclone

Definition: “A storm-scale region of rotation, typically around 2-6 miles in diameter and often found in the right rear flank of a supercell (or often on the eastern, or front, flank of an HP storm). The circulation of a mesocyclone covers an area much larger than the tornado that may develop within it. Properly used, mesocyclone is a radar term; it is defined as a rotation signature appearing on Doppler radar that meets specific criteria for magnitude, vertical depth, and duration. It will appear as a yellow solid circle on the Doppler velocity products. Therefore, a mesocyclone should not be considered a visually-observable phenomenon (although visual evidence of rotation, such as curved inflow bands, may imply the presence of a mesocyclone).” -- National Weather Service
No. 7 – Updraft

Definition: “A small-scale current of rising air. If the air is sufficiently moist, then the moisture condenses to become a cumulus cloud or an individual tower of a towering cumulus or Cb.” -- National Weather Service
No. 6 – Wall cloud

Definition: “A localized, persistent, often abrupt lowering from a rain-free base. Wall clouds can range from a fraction of a mile up to nearly five miles in diameter, and normally are found on the south or southwest (inflow) side of the thunderstorm. When seen from within several miles, many wall clouds exhibit rapid upward motion and cyclonic rotation.
However, not all wall clouds rotate. Rotating wall clouds usually develop before strong or violent tornadoes, by anywhere from a few minutes up to nearly an hour. Wall clouds should be monitored visually for signs of persistent, sustained rotation and/or rapid vertical motion.
‘Wall cloud’ also is used occasionally in tropical meteorology to describe the inner cloud wall surrounding the eye of a tropical cyclone, but the proper term for this feature is eyewall.” -- National Weather Service
No. 5 – Scud clouds

Definition: “Small, ragged, low cloud fragments that are unattached to a larger cloud base and often seen with and behind cold fronts and thunderstorm gust fronts. Such clouds generally are associated with cool moist air, such as thunderstorm outflow.” -- National Weather Service
No. 4 – Rain-wrapped

Definition: -- Rain-wrapped tornadoes are twisters cloaked by a wall of rain and thunderstorms. This makes visibility of the tornado almost impossible and, because of that, are considered to be some of the most dangerous kinds of tornadoes.
No. 3 – Hail core

Definition: “The core refers to the heaviest precipitation. The most violent rain and hail in a supercell tend to be on the outer edge of the updraft on the downdraft side of the storm. Extreme turbulence on the edge of the updraft can contribute to significant hail growth. As hail falls into above freezing air it sheds its moisture as rain.” -- TheWeatherPrediction.com
No. 2 – Multiple vortex

Definition: “A tornado in which two or more condensation funnels or debris clouds are present at the same time, often rotating about a common center or about each other. Multiple-vortex tornadoes can be especially damaging.” -- National Weather Service
No. 1 – Hook echo

Definition: “A radar reflectivity pattern characterized by a hook-shaped extension of a thunderstorm echo, usually in the right-rear part of the storm (relative to its direction of motion). A hook often is associated with a mesocyclone, and indicates favorable conditions for tornado development.” -- National Weather Service














Richard Hall is an award-winning newsroom developer, editor and blogger for NewsOK. He was born in Austin, Texas, spent his childhood in southern California and has lived in Norman since 1999. He graduated from the University of Oklahoma in 2008. Read more ›