NASA satellite imagery revealed a cloud-filled eye in a weaker Hurricane Darby. Although obscured by clouds in previous days, the eye was apparent in wind data from NASA's RapidScat instrument.
On July 16, NASA's RapidScat instrument measured the surface winds around Hurricane Darby and found the strongest winds all around the storm with the exception of the southwestern quadrant. Sustained winds were greater than 30 meters per second (67 mph/108 kph).
RapidScat flies aboard the International Space Station and is helpful to forecasters because it shows where the strongest winds are in the storm (winds are not evenly distributed).
On July 16, NASA's RapidScat instrument found Darby's strongest winds (red) greater than 30 meters per second (67 mph/108 kph) around the entire storm with the exception of the southwestern quadrant. Credit: Credits: Doug Tyler/JPL
On July 17 at 09:30 UTC (5:30 a.m. EDT), the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard the Suomi NPP satellite captured an image of Hurricane Darby. The VIIRS image showed cloud-filled eye surrounded by a ring of powerful thunderstorms, and bands of thunderstorms wrapping into the low-level center.
The Suomi NPP satellite is managed by NASA and NOAA with support from the U.S. Department of Defense.
At 5 a.m. EDT (0900 UTC) on Monday, July 18, the center of Hurricane Darby was located near latitude 18.5 north and longitude 130.2 west. That's about 1,345 miles (2,165 km) west of the southern tip of Baja California, Mexico. Darby is moving toward the west near 10 mph (17 kph). NOAA's National Hurricane Center (NHC) said that a westward to west-northwestward motion at a slightly faster forward speed is expected during the next couple of days. Maximum sustained winds have decreased to near 80 mph (130 kph) with higher gusts.
NHC forecaster Roberts noted that "Deep convection associated with Darby continues to diminish this morning with a couple of thin, fragmented curved bands located just to the southwest of the center of circulation."
NHC said additional weakening is forecast during the next 48 hours, and Darby should become a tropical storm later today. For updated forecasts on Darby, visit: http://www.nhc.noaa.gov.
source: NASA/Goddard Space Flight Center