Tropical weather analysis - November 4, 2012
An area of low pressure off over the eastern Pacific about 380 miles west-southwest of Manzanillo is moving little. The low has a well-defined surface circulation as denoted by scatterometer, satellite, and microwave data, but strong southwesterly shear is keeping the small center completely exposed. The low is producing a large area of showers and thunderstorms to the northeast of the center for several hundred miles.
Figure 1. Latest infrared satellite image of Invest 90E. Image credit: NOAA
This activity is affecting the Mexican coast between Puerto Vallarta and Manzanillo, but surface observations suggest that there is little wind accompanying the thunderstorms. Upper-level winds are expected to remain highly unfavorable for additional development to occur as the low drifts slowly northwestward, then gradually turns west-northwestward away from Mexico. If the system were deeper, it would gravitate toward the mid-level flow on a path towards Mexico, but since it is devoid of convection, it will tend to follow the lower-tropospheric steering.
Probability of development in 48 hours: 20%