Hurricane Seymour became a major hurricane on Oct. 25 as the Global Precipitation Measurement mission or GPM core satellite analyzed the storm's very heavy rainfall and provided a 3-D image of the storm's structure.
Hurricane Seymour is the third hurricane in the Eastern Pacific this season to reach category four on the Saffir-Simpson hurricane wind scale. The pace of hurricane formation in the eastern Pacific Ocean is a slower than during El Nino conditions last year. In the 2015 season the 28th hurricane called Patricia had already occurred. Patricia was the second-most intense tropical cyclone on record worldwide with wind speeds of 187 knots (215 mph). Patricia hit the Mexican coast last year with winds of 150 mph.
The GPM core observatory satellite traveled directly over hurricane Seymour on the morning of October 25, 2016 at 7:46 am PDT (1646 UTC). GPM's Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) data were used to show the intensity of rainfall within Hurricane Seymour. GPM's radar (DPR Ku Band) revealed that the hurricane had rain falling at the extreme rate of almost 166 mm (6.6 inches) per hour in the southern side of hurricane Seymour's circular eye. GPM is a joint mission between NASA and the Japanese space agency JAXA.
On Oct. 25 at 4:35 p.m. EDT (20:35 UTC) the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard the NASA-NOAA Suomi NPP satellite captured a visible image of Hurricane Seymour as it became a Category 4 hurricane with maximum sustained winds near 130 mph (215 kph). The eye of the storm was clearly visible and was surrounded by thick, powerful bands of thunderstorms.
At 11 a.m. EDT (1500 UTC) on Oct. 26 the National Hurricane Center (NHC) reported the center of Hurricane Seymour was located near 16.9 degrees north latitude and 120.2 degrees west longitude. That's about 785 miles (1,265 km) west-southwest of the southern tip of Baja California, Mexico.
Seymour is moving toward the west-northwest near 15 mph (24 kph) and a turn toward the northwest should occur later today, followed by a turn toward the north-northwest with a decrease in forward speed by Thursday, Oct. 27. A turn toward the north with a further reduction in forward speed is forecast by Oct. 28.
Maximum sustained winds have decreased to near 140 mph (220 kph) with higher gusts. Seymour is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Further weakening is expected, and rapid weakening should begin by tonight or Thursday, Oct. 27. The estimated minimum central pressure is 949 millibars.
NHC Forecaster Kimberlain said "Seymour continues to maintain an impressive central dense overcast, consisting of very deep convection around a 15 nautical mile wide well-defined eye. However, the distribution of convection has become slightly asymmetric since the last advisory, with the greatest coverage to the north and east of the center."
Hurricane Seymour is beginning to move over colder water as it moves northward and start to weaken. Seymour is expected to become a depression over the open waters of the Eastern Pacific on Friday, Oct. 28.
For updated forecasts from NHC, visit: http://www.