Chapter 14 - Thunderstorms Flashcards
x3 Required to start a thunderstorm
Moist air
10,000 feet of deeply unstable air
A trigger to cause the air to rise
warm air underneath cold creates instability what trigger is this?
air mass
Frontal thunderstorms create instability how
cutting under the warm air
Squall line thunder storms are
a cold front 100’s miles long
Orographic thunderstorms can happen
Anytime because the land is always there
Build phase does what and for how long
lots of up draughts only. 20 mins. vertical speeds of 60 kts
Mature phase does what and for how long
On set of precipitation, Up and down draughts, hail movements. 20 mins
Dissipating phase
down draughts only 1.5-2.5 hours
Cb that is punching the tropopause and having hail coming out is said to have
An overshooting top
Multicell / supercell TS have what
develop strong upper winds ahead and tornadoes behind
Mesoscale convection areas are
Cluster of thunderstorms across 100-1000km over 1-2 days
Hazards with thunderstorms
Gusty winds
roll cloud / shelf cloud
rotor/roll cloud created from the down draughts
Microbursts - which spread over an area up to 4km and last up to 5 mins
With thunderstorms what happens to virga
Increases intensity from the warming
Which side of the storm are there more Hazards
Windward side
What is distinctive about St elmos fire
Visible blue plasma discharge which is constant
