Figure 1 1 . 0000-hr UTC, 29 October 1991, surtace analysis 



PV = ( iiJlZ dx dy dp 



Pi 



dp/dQ 



(1) 



where 6 is the potential temperature, ^g is the relative vorticity in isentropic 

 coordinates, and / is the Coriolis parameter. The problem with application of 

 this expression is that the dp term in the integrand causes the expression to go 

 to infinity at the surface (essentially division by zero). By assuming that 6 is 

 monotonic in p, then 



16 



Chapter 3 Halloween Storm 



