Typhoon Mirinae is moving west and away from the Northern Marianas Islands on a track to a landfall in the Philippines by the weekend. As Mirinae has moved west, NASA’s infrared and microwave satellite imagery have seen high, strong thunderstorm development, and a developing eye. Typhoon Mirinae’s maximum sustained winds are now up to 98 mph (157 km/hr), and its center is approximately 930 nautical miles (that’s 1,070 miles or 1,722 kilometers) east of Manila, Philippines. The coordinates of its center are 16.2 North latitude and 136.9 East longitude. Mirinae is moving west at 17 mph. Tropical storm-force winds extend out to 100 miles from Mirinae’s center, while typhoon/hurricane-force winds extend 20 miles out from its center. Mirinae is stirring up waves up to 22 feet high. Mirinae is intensifying in part because of “strong radial outflow and warm sea surface temperatures,” according to forecasters at the U.S. Navy’s Joint Typhoon Warning Center (JTWC). JTWC is the organization that forecasts storms in the Western Pacific Ocean. Radial outflow is important in a tropical cyclone development because it spreads ice particles outward from the center of the storm, spreading clouds and precipitation. Basically it helps the storm grow larger.
The infrared imagery revealed that the cloud tops of Mirinae are close to the top of the troposphere. That means they are strong thunderstorms, where temperatures are colder than -63 Fahrenheit. AIRS data is also coupled with data from the Advanced Microwave Sounding Unit (AMSU) that flies with AIRS on Aqua to create microwave images of storms. The AMSU image uses the radiances of the 89 GHz channel, and the cold areas in those images indicate where there is precipitation or ice in the cloud tops. Mirinae has intensified steadily and will continue to do so until landfall in the Philippines on Saturday. Landfall in Luzon between the cities of Soliven and San Jose is still expected to occur around 0600 UTC (2 a.m. EDT, 2 p.m. Asia/Manila local time) on Halloween. |
It seems like a common occurrence this season that there are two tropical cyclones spinning in the Western Pacific Ocean and this week, Lupit and newly formed 23W are proof. NASA’s Aqua satellite flew over the Western Pacific early today and captured both storms in one satellite image. Tropical Storm Lupit is becoming extra-tropical and is expected to track parallel to Japan while remaining at sea, east of the island. Meanwhile, Tropical Storm 23W is approaching Saipan and Andersen Air Force Base and is moving west. The U.S. Navy’s Joint Typhoon Warning Center (JTWC) forecasts tropical cyclones in the Western Pacific Ocean. The JWTC issued their final warning for Extra-tropical Storm Lupit today, October 26 at 0300 UTC (12 a.m. local time Tokyo). At that time, Lupit had maximum sustained winds near 52 mph and was stirring up rough surf and high waves along eastern Japan’s coastline. Extra-tropical storm Lupit was located approximately 580 nautical miles southwest of Tokyo, Japan, near 28.4 North and 134.8 East. It was moving northeast at 21 mph, and is expected to continue moving in that direction staying in open ocean. Lupit was completing transition to an extra-tropical storm and is also being adversely affected by wind shear (winds blowing at the storm in different levels of that atmosphere, that tear the storm apart). NASA’s Aqua satellite flew over both Lupit and TD23W on October 26 at 3:41 UTC (October 25 at 11:41 p.m. EDT). The Atmospheric Infrared Sounder (AIRS) instrument on Aqua captured both a visible and infrared image of the storms. The infrared satellite image confirmed that all of Lupit’s deep convection (developing strong thunderstorms) has dissipated, and the most intense precipitation has shifted all to the northeast of the center of circulation, further exposing the center to wind shear. Meanwhile, the image also showed that 23W appeared to be getting well-organized. Tropical Storm 23W had maximum sustained winds near 40 mph at 11 a.m. EDT on October 26. The storm’s center was about 200 nautical miles east of Guam, near 13.4 North and 147.7 East. It was moving west-northwest near 17 mph. NASA’s CloudSat satellite also flew over 23W earlier this morning. CloudSat captured a side view of 23W’s clouds on Oct. 26 between 03:43 – 03:46 UTC. CloudSat revealed sustained winds of 27 mph and a minimum central pressure of 1002 millibars when it was centered near 122 North and 151.3 East. Sustained winds have since increased to 40 mph. CloudSat also showed some high, strong thunderstorm cloud tops over 14 kilometers (almost 9 miles) high. The forecast track from the JTWC takes Tropical Storm 23W between Andersen Air Force Base (island) and the island of Saipan, located north of Andersen. The storm is then forecast to intensify and move west toward the Philippines. |
