The relationship between the dominant spatial pattern
of China landfalls, as described by the LI, and climate
is first examined using indices for ENSO and the
PDO. Although the SOI is not linearly related to the
LI, there is a weak relationship with the PDO. Examination
of additional variables that might explain
the landfall pattern indicates that a north-south SLP
gradient between western China and Mongolia might
be used as a predictor of regional typhoon activity.
When the SLP gradient features relatively high pressures
over Mongolia and low pressures over western
China, typhoons are more likely to track westward toward
southern China. In contrast, when the SLP gradient
weakens, recurving typhoons are more likely to
visit the northern provinces of China.