NOTES: 16 NOV 96 Following the entrance of the 1st major fall high pressure system into the Gulf of Mexico intense upwelling developed in Mexico's Gulf of Tehuantepec from high velocity [exhaust] winds that blew south and westward across the Mexican Sierra Madre out over the Pacific. SSTs dropped nearly 5 degrees C in this region over just a few days. The region of upwelling extends seaward nearly 300 miles. AES