NASA sees wind shear affecting Tropical Storm Chanthu

Visible imagery from NASA's Aqua satellite showed wind shear was affecting Tropical Storm Chanthu as it moved parallel to the big island of Japan early on Aug. 16. Chanthu is expected to make landfall and move north over the island of Hokkaido.

On Aug. 15 at 11:25 p.m. EDT (Aug. 16 at 0325 UTC) visible imagery from the MODIS or Moderate Resolution Imaging Spectroradiometer instrument aboard NASA's Aqua satellite showed clouds and showers in Chanthu were being pushed to the north and east from moderate southwesterly vertical wind shear.

On Aug. 16 at 11 a.m. EDT (1500 UTC), the center of Tropical Storm Chanthu was located near 36.2 degrees north latitude and 141.1 degrees west longitude. That's about 64 nautical miles east of Yokosuka, Japan. Chanthu is moving toward the north-northwest at 20.7 mph (18 knots/33.3 kph)

Maximum sustained winds were near 40 mph (35 knots/62 kph) and Chanthu is expected to maintain strength over the next day as it moves over the northern part of the big island of Japan.

For updated warnings and watches from the Japan Meteorological Agency, visit: http://www.jma.go.jp/jma/indexe.html.

The Joint Typhoon Warning Center said that Chanthu is expected to track more north-northeastward as a sub-tropical ridge (elongated area of high pressure) weakens in response to an approaching mid-latitude trough (elongated area of low pressure). By early Aug. 17, Chanthu is forecast to being extra-tropical transitioning where it will become a cold-core low pressure area.