Figure 15. 1200-hr UTC, 30 October 1991, surlace analysis 



currents, the westward "tilt" (with height) of the trough axis would tend to 

 cause the surface low to move westward. 



Thermal Gradient Description 



The presence of a strong anticyclone to the northwest and Hurricane Grace 

 to the southeast of the low which developed into the Halloween Storm, pro- 

 duced an extraordinary temperature gradient for an early season event. The 

 analysis procedures of the thermal conditions present in this event follow those 

 of Neiman and Shapiro (1993) for a similar 1989 event (IOP-4). However, the 



20 



Chapter 3 Halloween Storm 



