NASA sees a weakening Hurricane Ignacio moving parallel to Hawaiian Islands

NASA's Aqua satellite passed over Hurricane Ignacio and viewed the storm in infrared light, providing valuable temperature data. Aqua saw a weaker Ignacio moving parallel to the Hawaiian Islands.

The Atmospheric Infrared Sounder or AIRS instrument aboard Aqua gathers infrared data that shows temperatures. That AIRS data was made into a false-colored infrared image from August 30 at 22:47 UTC (6:47 p.m. EDT) and showed high, cold, strong thunderstorms surrounded the center of Hurricane Ignacio.

AIRS imagery also showed a thick band of thunderstorms spiraling into the northern quadrant of the storm from the east. Coldest cloud top temperatures were as cold as -63F/-53C around the center of the hurricane, somewhat warmer than they were the day before. NASA research has shown that thunderstorms with cloud tops that cold and high in the troposphere have the potential to generate heavy rainfall. As Ignacio weakens, those cloud tops will drop and become less cold. When infrared data shows that cloud tops are warmer, it means the uplift in the storm is weakening.

On August 31, NOAA's Central Pacific Hurricane Center (CPHC) stated that infrared satellite images show that Ignacio continued to steadily weaken...down from a peak intensity that was reached on August 30, with a cloud-filled eye barely discernible.

On August 31 at 1500 UTC (11 a.m. EDT/5 a.m. HST), the center of Hurricane Ignacio was located near latitude 20.9 north and longitude 150.8 west. That's about 460 miles (735 km) east of Honolulu, and about 335 miles (540 km) east of Hana, Hawaii. The estimated minimum central pressure is 966 millibars.

Maximum sustained winds are near 105 mph (165 kph) and the CPHC expects significant weakening over the next couple of days.

Wednesday. Hurricane force winds extend outward up to 60 miles (95 km) from the center and tropical storm force winds extend outward up to 175 miles (280 km). Because Ignacio remains several hundred miles from land, Hawaii is not experiencing the hurricane-force winds.

Ignacio is moving toward the northwest near 10 mph (17 kph) and this motion Is expected to continue for the next couple of days.

The CPHC forecast calls for Ignacio to track in a general north-northwesterly direction over the next several days, paralleling the Hawaiian Islands to the east, but never making landfall. Ignacio is also forecast to weaken to a tropical storm by September 2 as it continues heading northwest. For updated forecasts, visit NOAA's CPHC website: http://www.prh.noaa.gov/cphc.