As residents and tourists in western Mexico brace for heavy rain, flooding and ferocious winds generated by approaching Hurricane Jova, scientists are marveling at satellite images that appear to show Jova "winking," or opening and closing its eye (see images above).
This phenomenon is caused when the eye becomes cloud covered when viewed from above.
"In addition to Jova's wink, the infrared AIRS instrument on NASA's Aqua satellite got a cold stare from Jova's eye," states a passage in a NASA story on the storm, which has prompted hurricane warnings from Punta San Telmo northward to Cabo Corrientes near Puerto Vallarta. "Infrared data measures cloud top temperatures, and NASA AIRS instrument noticed they were as cold as -112 degrees Fahrenheit in the thunderstorms in Jova's eyewall.
"Those frigid cloud top temperatures indicate there's a tremendous amount of power in the storm."
Jova, whose center was expected to make landfall late Tuesday afternoon, was a Category 3 storm when the accompanying images were captured, showing an open and closed eye. But late Tuesday morning the storm was downgraded to Category 2 status, with maximum sustained winds of 100 mph, according to the National Hurricane Center.
That's still a very powerful storm, which could drop as much as 20 inches of rain in areas. Hundreds of homes have been evacuated in the state of Jalisco, according to reports.
Puerto Vallarta, a major tourist destination in Jalisco, is playing a key role in the Pan American Games, which begin Friday in nearby Guadalajara. Sailing, ocean swimming and beach volleyball are among sports scheduled to be held in Puerto Vallarta.
"Vallarta Yacht Club and Paradise Village Marina are well-versed with both weather issues and major sailing events," said Mike Danielson of PV Sailing. "We do not foresee any delays, just a lot of work. All boats have been stowed in parking garages."
Puerto Vallarta is generally well-protected from hurricanes, thanks to nearby mountain ranges, which serve as a storm break, and its sprawling bay. But surges generated by Hurricane Kenna in 2002 caused extensive damage along the coast.
With Jova expected to make landfall to the south, opposite the Sierra Madre range, storm surges should not be a major problem in Puerta Vallarta. But residents are not taking Jova lightly.
"I've seen a lot of tape on larger windows, and that says something here," said Pat Henry, a longtime resident who once solo-curcumnavigated the planet in a sailboat. "In 2002, my boat came through fine, but I lost almost everything in the apartment where I was living. This time I'm on higher ground farther from the water."
Jova is expected to weaken rapidly not long after making landfall.
-- Images are courtesy of NASA