Chapter 14 Thunderstorms Flashcards
what is a thunderstorm?
a storm containing lightning and thunder; convective storms
what is a severe thunderstorm?
one of large hail (> 1 inch in diameter)
or wind gusts (over 50kts)
or tornado
what are the stages of the ordinary cell thunderstorms?
- cumulus stage
- mature stage
- dissipating
low wind shear, around an hour long, in warm locations
what is the cumulus stage?
-growth stage
-updrafts form cloud which grows vertically
-no precip, no lightning or thunder
what is the mature stage?
-precip starts
ENTRAINMENT: creates down draft, dry air sinks into open space
GUST FRONT: cold downdraft, reaches the surface, and spreads in all directions
what is the dissipating stage?
-downdraft suppresses updraft, cloud dissipates from the bottom up
what is a multi-cell thunderstorm?
-medium wind shear, multiple cells at once, one forms as one dies out
how does a multi-cell thunderstorm work?
-tilted updraft from wind
-when down draft hits ground at angle, it allows for updraft
-lasts for hours
what are microbursts?
localized downdraft, smaller and stronger
what is a squall line?
line of thunderstorm, storm can develop ahead of front
what is a derecho?
straight-line winds, happens in summer, very strong wind
what is a mesoscale convective complex?
several individual multi-cell thunderstorms, not much movement
what is a supercell thunderstorm?
very strong wind shear
-downdraft cannot suppress updraft
-one cell=hours
-thunderstorms form east of dry line
what is lightning?
discharge of electricity in mature storms
what is thunder?
explosive expansion of air due to heat from lightning
