NASA sees a western weakness in Tropical Storm Miriam

NASA infrared satellite imagery showed Tropical Storm Miriam had strong convection and thunderstorm activity in all quadrants of the storm on Sept. 26, except the western quadrant. That activity waned dramatically in 24 hours because of strong wind shear and cooler sea surface temperatures.

The Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite captured infrared data on Tropical Storm Miriam on Sept. 26 at 2047 UTC, when it was off the coast of Baja California. Strongest thunderstorms with very cold cloud top temperatures appear to surround north, east and south of the center of circulation. By Sept. 27, only the northern quadrant of the storm appeared to have those strong thunderstorms.

Miriam appears to be weakening quickly because of strong wind shear and cooler waters.

At 11 a.m. EDT on Sept. 27, Miriam's maximum sustained winds had decreased to near 40 mph (65 kmh) and further weakening is expected. The National Hurricane Center noted that Miriam could become a remnant low later today or tomorrow, Sept. 28.

The center of Tropical Storm Miriam was located near latitude 22.2 north and longitude 116.3 west. Miriam is moving northwest near 6 mph (9 kmh) and is expected to turn west.

Regardless of the weakening condition of the storm, Miriam is still generating dangerous ocean swells along the south and west coasts of the southern and central Baja peninsula today but those will begin to gradually subside by Sept. 28.