Winnie is the only tropical cyclone known to form in December in the
northeast Pacific during the modern
record. Its initial disturbance developed close to 400 miles south-southwest of Acapulco during the
morning of December 3rd. The system organized as it moved northwest, becoming a tropical depression
early on the morning of the 4th. By noon, it had strengthened into a tropical storm. Winnie turned north
on the southwest side of the subtropical ridge. By late on the 5th, the storm had intensified into a hurricane
as its forward motion slowed to 4 mph. The cyclone stalled near a col in the steering flow about 150 miles
south of Manzanillo, reaching its peak intensity. On the morning of the 6th, an upper level trough approached
from the west which led to vertical wind shear which weakened the storm. By the morning of the 7th, Winnie
had dimished to a tropical depression which began to drift back towards the west in the low level flow. Its
remaining thunderstorm activity pulsed for the next couple days as its remnants continued to the west.
The graphics below the storm total rainfall for Winnie. Data was provided by the Comision Nacional
del Agua, the parent agency of Mexico's national weather service.