Tropical Depression One-E forms, no threat to Mexico
Nature is jumping the gun a little early this year, as the first cyclone of the 2012 Pacific hurricane season, Tropical Depression One-E, has developed a day before the official start of the season. This development is from an area of disturbed weather, previously dubbed Invest 90E, that formed about 550 miles south-southwest of Acapulco, Mexico two days ago. An OceanSat pass from last night revealed a well-defined center and maximum sustained winds of 25-30 mph, but convection was ill-defined and relatively shallow at the time. Visible satellite imagery from this morning combined with Satellite estimates, however, revealed that convection was deep enough and sufficiently defined to renumber Invest 90E to Tropical Depression One-E.
Figure 1. Afternoon satellite imagery of Tropical Depression One-E.
The forecast for 01-E
Tropical Depression One-E lies atop warm Sea Surface Temperatures in excess of 29 °C and light wind shear between 10-15 knots, both of which are conducive for further intensification. These thermodynamics should remain at least marginally favorable over the next 24-36 hours which may allow the depression to briefly attain tropical storm status. If that were to occur, it would be given the name "Aletta". After that, a steep increase in wind shear is forecast by the global models as a strong upper-level trough passes near the system. This should lead to dissipation by 84-96 hours out as the depression moves west into increasingly cool waters around the southeastern side of a well-defined ridge of high pressure. This ridge should act to keep 01-E a far distance from the Mexico coastline.