Thursday, 14 July 2011
As expected atmospheric conditions have improved and Tropical Storm 08W strengthened into a Typhoon yesterday. As of 00z July 14 (8 p.m. EDT July 13), Typhoon 08W (MA-ON) had maximum sustained winds of 90 knots (105 mph), making it a Category 2 Typhoon.
From the visible satellite image above, you can see an eye has formed in the center of the typhoon. The storm is really getting its act together as a result of warm sea surface temperatures and a ridge of high pressure in place. Both are excellent conditions for brewing a strong typhoon (or “hurricane” if we were talking about an Atlantic Ocean storm). Also evident in the image above is one very well defined outflow band which expands in a semi-circle across most of the northern half of the typhoon, well outside of the center. This banding feature is indicative of a ridge of high pressure aloft as well as increasing organization of the typhoon. Typically, when an outflow band is this well structured the typhoon is rapidly strengthening, or is organizing in a way that will soon lead to rapid intensification.
Based on the favorable oceanic and atmospheric conditions as well as the visible satellite clues, it’s no surprise that the Joint Typhoon Warning Center is forecasting Typhoon 08W to strengthen over the next 24 hours. In fact they are forecasting some rapid strengthening over the next 36 to 72 hours and expect Typhoon 08W to become a strong Category 4 Typhoon by the weekend. As the typhoon curves northwest towards Japan on Monday and Tuesday (July 18/19), they are forecasting some weakening due to increased wind shear. But from their intensity forecast and their discussion, it looks like they believe the typhoon may only weaken to a weak Category 3 typhoon, with 100 knot (115 mph) maximum sustained winds as it comes very close to or has a direct impact on Japan mid next week.
Residents in Japan — especially southern Japan — should monitor this typhoon closely over the next several days.