Early October saw the remnants of September’s hurricanes waning, as Jelawat and Ewiniar both became extra-tropical storms. Ewiniar was never a very powerful storm, and it succumbed to wind shear forces on September 30th. Over the weekend of September 29th and 30th, the former super typhoon Jelawat made landfall in Japan about 120 miles west of Tokyo, bringing heavy rain and wind. Its power had diminished substantially from the super typhoon status that it sported in the open ocean.
Tropical Storm Gaemi Moves Toward Vietnam
Tropical Storm Gaemi is packing 55 knot winds, and high, strong thunderstorms are present in Gaemi’s center. Gaemi is currently over 500 nautical miles east of Vietnam, but it is expected to make landfall near Hue, Vietnam this Saturday.
Tropical Storm Nadine Persisting in the Azores
Tropical Storm Nadine reached her three week birthday this week, and is bringing rain and wind to the Azores. This Tropical Storm is expected to weaken substantially by the end of the week. The wind shear near the tropical storm has been intense, and the ocean temperatures are cool, meaning that the storm is becoming weaker. Due to the strong wind shear, the associated thunderstorms have been pushed northeast of Nadine.
Tropical Storm Oscar On the Way?
Tropical Storm Oscar might emerge from Tropical Depression 15 this week, but the storm is not expected to last very long. Atmospheric conditions are not conducive to strong storm development, and even if Oscar develops near Cape Verde, it’s expected to dwindle into an extra-tropical storm shortly afterwards.
Tropical Storm Maliksi Moving Toward Japan
After a month of typhoons in September, Japan sees another tropical storm moving quickly toward it. This time, it’s Tropical Storm Maliksi, which is located to the south-southeast of Japan but is moving quickly north at 21 knots. The storm is bringing along strong thunderstorms in it eastern section.
Wind Shear and Tropical Storm Development
This week has seen a lot of discussion of the role that wind shear plays in the development and demise of tropical storms. There are several factors that can inhibit the movement and strengthening of a tropical storm into a tropical cyclone. When a storm meets the land, it loses a lot of the power that it receives from warm ocean waters, and it weakens. When a storm moves into an area with cooler ocean conditions, it also starts to deteriorate. In the case of many of the tropical storms this week, the factor reducing the storms’ intensity has been external wind shear. Wind shear can present a tropical storm from developing into a stronger cyclone, it can slow the tropical storm, and it can cause the storm to slow and fragment.
NASA. Hurricanes / Tropical Cyclones. (2012). Accessed October 4, 2012.