On September 24, 2012 Hurricane Miriam spun off of the coast of Mexico as a Category 2 hurricane, carrying maximum sustained winds of 105 mph (165 km/h). The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured this true-color image of the storm at 21:00 UTC (2:00 p.m. PDT) on that same day.
In this image, the broad eye (about 30 nautical miles wide) is covered by high clouds. Infrared imagery taken near the same time showed that the cloud top temperatures near the eye were cooling, which indicated thunderstorms located around the eye continued to have strong uplift. The outer bands of the storm are just brushing western Mexico, but the primary hazard to land at this time was neither rain nor wind, but extremely heavy surf along coastal southern and western Baja California.
Not long after this image was captured, Miriam began strongly interacting with wind shear, which took much of the punch out of the storm. By September 26, Miriam became a tropical storm, and at 11:00 a.m. EDT had maximum sustained winds near 65 mph (100 km/h). At that time it was located about 425 mi (680 km) west-southwest of the southern tip of Baja California.
Early in the morning of September 27, Miriam's maximum sustained winds had decreased to near 40 mph (65 km/h) and further weakening was expected. Later that afternoon, the National Hurricane Center reported that the last bit of deep convection had dissipated, and at 0900 UTC (2:00 p.m. PDT) declared Miriam as a tropical depression. Because sea temperatures are unfavorable and wind shear is still considerable, the storm is not expected to restrengthen. The NHC forecasts that Miriam should dissipate completely within the next three days.