When NASA's Aqua satellite passed over Tropical Storm Ockhi, it measured cloud top temperatures that showed strongest storms were off the coast of southwestern India. Infrared data showed Ockhi intensifing into a typhoon.
The Atmospheric Infrared Sounder aboard NASA's Aqua satellite captured an infrared image of Ockhi on Nov. 30 at 3:17 p.m. EST (20:17 UTC) and showed coldest cloud tops and strongest storms were just off the southwestern coast of India.
Those cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Storms with cloud top temperatures that cold have the capability to produce heavy rainfall. Hours after Aqua passed overhead, Ockhi strengthened from a tropical storm to hurricane-force.
On Dec. 1 at 10 a.m. EST (1500 UTC) the Joint Typhoon Warning Center noted that Ockhi had become a typhoon. Maximum sustained winds were near 80 knots. Ockhi was centered near 9.1 degrees north latitude and 72.3 degrees east longitude. That's about 960 nautical miles north of Diego Garcia. Ockhi was speeding to the west at 7 knots (8 mph/13 kph).
The Joint Typhoon Warning Center said "by 48 hours (Dec 3 at 10 a.m. EST/1500 UTC), Ockhi will begin to interact with a trough (elongated area of low pressure) and begin to track northeastward. Ockhi will begin extratropical transition as it tracks northeastward and will become extratropical as it makes landfall over northwest India."