STORM2K

How come the Atlantic gets windshear during El Nino, which makes it less active. On the other hand, the Pacific is more active during El Nino.

Basically, the upper air patterns are different which changes normal wind shear averages:

http://www.cpc.noaa.gov/products/analys ... circ.shtml

http://www.cpc.noaa.gov/products/analys ... circ.shtml

http://www.cpc.noaa.gov/products/analys ... chem.shtml

http://www.cpc.noaa.gov/products/analys ... chem.shtml