NASA finds very cold storm tops circling Hurricane Norman’s center
When NASA's Aqua satellite passed over Hurricane Norman on Aug. 30 infrared data showed very cold storm tops around a 20 nautical-mile-wide eye.
NASA's Aqua satellite passed over Norman on Aug. 30 at 5:29 a.m. EDT (0929 UTC). The Atmospheric Infrared Sounder or AIRS instrument analyzed the storm in infrared light which provides temperature information. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.
On Aug. 30 at 11 a.m. EDT (1500 UTC), NOAA's National Hurricane Center or NHC noted Norman had rapidly strengthened during the past 12 to 24 hours, with the development of a well-defined 20-nautical mile wide eye and a thick ring of cold cloud tops of minus 94 to minus 121 degrees Fahrenheit (minus 70 to minus 85 degrees Celsius) Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.
The eye of Hurricane Norman was located near latitude 17.8 degrees north and longitude 118.0 degrees west. That's about 630 miles (1,015 km) west-southwest of the southern tip of Baja California, Mexico.
Norman was moving toward the west near 8 mph (13 kph), and this motion is expected to continue today. A west-southwestward motion is forecast on Friday, followed by a turn back toward the west and west-northwest over the weekend.
Maximum sustained winds have increased to near 150 mph (240 kph) with higher gusts. Norman is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some additional strengthening is forecast during the next 12 to 24 hours.
Gradual weakening is anticipated to begin by Friday night or Saturday, however, Norman is expected to remain a very powerful hurricane during the next few days.
For updated forecasts, visit: http://www.nhc.noaa.gov.
By Rob Gutro
NASA's Goddard Space Flight Center