NASA satellite imagery has helped forecasters watch Hurricane Felicia run into cooler waters and increasing wind shear, two things that have taken her strength "down a peg or two." Felicia will continue to weaken further over the weekend as she heads to Hawaii where landfall isn't expected until late Monday or early Tuesday.
By Friday, Aug. 7 at 11 a.m. EDT (5 p.m. Hawaiian Time), Felicia had weakened from a Category four hurricane on the Saffir-Simpson scale to a Category two hurricane with sustained winds near 100 mph. Further weakening is expected over the weekend, and forecasters at the National Hurricane Center are forecasting that by Monday, Aug. 10 Felicia will be a tropical storm.
Felicia is moving west-northwest at about 13 mph and will turn toward the west over the weekend. Her minimum central pressure continues rising and is currently 973 millibars. Rising air pressure means a weakening storm, and that's good news for the big island of Hawaii.
Over the weekend as Felicia continues her track toward Hawaii, she's running into cooler waters that will continue sapping her strength. Hurricanes need warm waters of at least 80 degrees Fahrenheit to maintain strength. In addition, vertical wind shear (winds that can weaken and tear a storm apart) will increase from the west.
AIRS captured an infrared image of Hurricane Felicia tracking through the Eastern Pacific Ocean on August 7 at 6:59 a.m. EDT showing a tight circular shape, indicating she's still a powerful hurricane.
AIRS provides visible, infrared and microwave images of tropical storms. Infrared imagery shows the temperature of the cloud tops which gives a hint about the power of the thunderstorms in a tropical cyclone. The colder the clouds are, the higher they are, and the more powerful the thunderstorms are that make up the cyclone.
NASA also creates imagery from a satellite operated by the National Oceanic and Atmospheric Administration and created a movie of Hurricane Felicia's track through the Eastern Pacific Ocean. Images from Aug. 5 through Aug. 7 from the Geostationary Operational Environmental Satellite (GOES-11) were put together as a movie. NASA's GOES Project, located at NASA's Goddard Space Flight Center, Greenbelt, Md. created the movie that clearly shows Felicia as a powerful Category Four hurricane with a very visible eye.