When cloud top temperatures get colder, the uplift in tropical cyclones gets stronger and the thunderstorms that make up the tropical cyclones have more strength. NASA's Aqua satellite passed over Hurricane Ignacio and infrared data revealed cloud top temperatures had cooled from the previous day.
Ignacio strengthened to a hurricane at 11 p.m. EDT on August 26. It became the seventh hurricane of the Eastern Pacific Ocean hurricane season.
A false-colored infrared image of Hurricane Ignacio was made at NASA's Jet Propulsion Laboratory in Pasadena California, using data from the Atmospheric Infrared Sounder or AIRS instrument that flies aboard NASA's Aqua satellite The AIRS data from August 27 at 11:23 UTC (7:23 a.m. EDT) showed that cloud top temperatures had cooled within Ignacio indicating that the uplift of air within the storm was stronger than it was on August 26. AIRS data showed the strongest thunderstorms had cloud top temperatures in excess of -63F/-53C.
Forecaster Blake at NOAA's National Hurricane Center noted that "Very cold cloud tops persist near the center of Ignacio, although the overall cloud pattern is not very symmetric and no eye is present in conventional satellite data. However, microwave images show an eye beneath the cirrus clouds."
At 5 a.m. EDT (2 a.m. PDT/0900 UTC) on Thursday, August 27 the center of Hurricane Ignacio was located near latitude 12.6 North, longitude 138.5 West. That's about 1,205 miles (1,940 km) east-southeast of Hilo, Hawaii. Ignacio was moving toward the west-northwest near 13 mph (20 kph) and this general motion is expected to continue through Friday. Maximum sustained winds have increased to near 85 mph (140 kph). The estimated minimum central pressure is 985 millibars.
The NHC noted that further strengthening seems likely with Ignacio over the next couple of days as the storm moves through an area with light-to-moderate easterly shear, warm water and a moist atmosphere. Ignacio's strength is expected to peak on August 29 when the maximum sustained winds are forecast to be near 110 knots (115 mph) before weakening commences.
The current five day forecast from the NHC brings Ignacio east of the Big Island of Hawaii. Ignacio has now moved into the Central Pacific Ocean, and forecasts will be covered by NOAA's Central Pacific Hurricane Center. For updates, visit: http://www.