Meso Exam 2 Flashcards
What KI indexes indicate thunderstorm probability?
15-19 : 10-20%
40 : 90-100%
What is the KI formula and what is it?
A thunderstorm probability index
KI = T850+Td850+Td700-T700-T500
What is LI measure and it’s formula?
It is a conditional severe weather index.
LI = T500 - Tp500
LCL at surface then moist to 500 for Tp
What do the LI values indicate?
> -3 : weak
-3 to -5 : moderate
<-5 : strong
What does SSI measure and the formula?
It is an index for the type of event of a storm.
SSI = T500 - Tp500
LCL at 850 lift moist to 500 for Tp
What do the SSI values stand for?
1 to 3 : rain
0 to -2 : some thunderstorms
-3 to -6 : severe thunderstorms
<-6 : possible tornadoes
What does TT stand for and the formula?
It is an event index.
TT = (T850+Td850)-(2*T500)
What do the TT values stand for?
44-48 : non-severe storms
49-55 : some severe storms
>55 : severe storms possible tornadoes
What are the two ways to calculate CAPE or CIN?
1cm = 0.0280 CAPE = -Rd((Tvp-Tvenv)+(Tvp-Tvenv)/2)*ln(Pup/Plow)
What is the surface energy budget equation?
Rn = Qh+Qe+Qg+Sn
What is Qh and Qe?
Qh is sensible heat flux. Deals with conduction
Qe is latent heat flux. Deals with phase changes (evaporation)
What is the Bowen ratio formula?
Qh/Qe
What do d(flux)/dz lead to when they are greater than or less than zero?
d(flux)/dz > 0: flux divergence, boundary layer warming, positive slope
d(flux)/dz < 0: flux convergence, boundary layer cooling,drying, negative slope
What are the lapse rate values?
GammaD = 10C/km GammaM = 6C/km
What are parcels AU,AS,CU,DN,and MN in terms of potential temp?
AU: dtheta/dz0
CU: dthetaE/dz<dtheta/dz
DN: dtheta/dz=0
MN: dthetaE/dz=0
