After days at hurricane-force, NASA-NOAA's Suomi NPP satellite showed that Tropical Cyclone Victor in the South Pacific Ocean was falling apart as a result of wind shear. Victor has weakened to a tropical storm.
On Jan. 22 at 0137 UTC (Jan. 21 at 8:47 p.m. EST) when NASA-NOAA's Suomi NPP satellite passed over Victor, the VIIRS instrument captured an infrared image of the storm that showed the strongest thunderstorms were being sheared or pushed to the east of the center from strong westerly vertical wind shear. There were still bands of thunderstorms wrapping into the low-level center.
At 0900 UTC (4 a.m. EST), Victor's sustained winds dropped to 40 knots (46 mph/74 kph), making it a tropical storm. It was centered near 22.3 degrees south latitude and 174.6 degrees west longitude, about 473 nautical miles east-southeast of Suva, Fiji. Victor was moving to the west at 9 knots (10.3 mph/16.6 kph). Victor is moving around the northwestern edge of a subtropical ridge (elongated area of high pressure) and is expected to curve south (around the western edge of the center).
On Jan. 22 at 0137 UTC NASA-NOAA's Suomi NPP satellite passed over Victor and saw the strongest thunderstorms (green) were being pushed east of the center from strong westerly vertical wind shear. Credit: Credits: NASA/NRL
Several warnings in Tonga remain in effect while others have been dropped as Victor weakened. The tropical cyclone warning previously in force for Tongatapu and 'Eua is now cancelled. The gale warning previously inforce for Tongatapu and 'Eua is now cancelled. A strong wind warning remains inforce for Vavau and Ha'apai and is now inforce for Tongatapu and 'Eua. A heavy damaging swells remain in force for all Tonga waters. For updates from the Tonga Meteorological and Coast Radio Services, visit: http://met.gov.to.
Because Victor has moved into an area with increased vertical wind shear and cooler sea surface temperatures, the Joint Typhoon Warning Center expects Victor to weaken over the next two days and dissipate.
source: NASA/Goddard Space Flight Center