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Tropical Cyclone Yalo formed yesterday and is expected to come to an end today, Feb. 26. NASA’s Terra satellite captured an image of the young storm that showed strong wind shear was already tearing the storm apart. On Feb. 25 at 20:30 UTC (3:30 p.m. EST) the Moderate Resolution Imaging Spectroradiometer instrument aboard NASA’s Terra satellite captured a visible image of Tropical Cyclone Yalo in the South Pacific Ocean. By that time, vertical wind shear had begun to increase and push the clouds and thunderstorms in the system to the southeast of the center. That wind shear continued to increase on Feb. 26 further weakening the storm.
The Joint Typhoon Warning Center issued their final bulletin on Yalo at 1500 UTC (10 a.m. EST) on Feb. 26. At that time, Yalo’s maximum sustained winds had already dropped to 35 knots (40 mph/62 kph) because of strong vertical wind shear. Yalo was centered near 23.4 degrees south latitude and 150.7 degrees west longitude, about 359 nautical miles (413.1 miles/664.9 km) south of Papeete, Tahiti. Yalo was moving to the southeast at 12 knots (13.8 mph/22.2 kph).
Animated enhanced infrared satellite imagery showed the presence of increasing vertical wind shear early on Feb. 26 as the bulk of clouds were decoupled from the low-level circulation center of the system.
Tropical Cyclone Yalo is being battered by significant vertical wind shear between 35 and 40 knots due to an approaching longwave trough (elongated area) of low pressure from the west. In addition to the strong wind shear, Yalo has moved over cool sea surface temperatures near 25 degrees Celsius that will exacerbate weakening and lead to the storm’s demise later on Feb. 26.