NASA sees wind shear battering Banyan
NASA's Terra satellite captured an infrared image of Typhoon Banyan that showed the strongest storms were being pushed northeast of the center from wind shear.
An infrared image taken Aug. 16 at 6:25 a.m. EDT (1025 UTC), from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Terra satellite showed cloud top temperatures of the weakening storm. Strongest thunderstorms with cloud tops so high in the troposphere they were as cold as minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). Those storms were blown to the northeast of the center as a result of southwesterly wind shear.
The Joint Typhoon Warning Center noted that infrared satellite imagery showed the "compact central convection has re-surged, slightly deepened, and momentarily regained a pinhole eye even as it continues to be sheared northeastward of the low level circulation center."
On Aug. 16 at 11 a.m. EDT (1500 UTC) the Joint Typhoon Warning Center noted that Banyan's maximum sustained winds had dropped to 75 mph (65 knots/120 kph) and it was weakening. It was located about 981 nautical miles north of Wake Island, near 36.9 degrees north latitude and 169.5 degrees east longitude. Banyan was moving to the northeast at a speedy 37 mph (32 knots/59 kph).
Environmental analysis indicates an increasingly unfavorable environment with moderate vertical wind shear and declining sea surface temperatures. That combination as Banyan tracks farther north will erode the system.