Tag Archives: Tropical Storm Nanmadol

Tropical Storm Nanmadol Nearing Kyushu

Tropical Storm Nanmadol was quickly nearing Kyushu on Monday.  At 1:00 p.m. EDT on Monday the center of Tropical Storm Nanmadol was located at latitude 31.0°N and longitude 127.4°E which put it about 215 miles (345 km) southwest of Sasebo, Japan.  Nanmadol was moving toward the north-northeast at 24 m.p.h. (39 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 986 mb.

The structure of Tropical Storm Nanmadol was still consistent with its designation of a tropical cyclone, but there were signs that it could be about to start the transition to an extratropical cyclone.  There was a core of thunderstorms around the center of circulation.  The strongest winds were occurring in the inner core which extended out about 25 miles (40 km) from the center.  Several rainbands were on the eastern side of the circulation.  There were far fewer showers and thunderstorms in the western half of the circulation.  There were some indications that Nanmadol could be pulling cooler, drier, more stable air into the western side of the tropical storm.

Tropical Storm Nanmadol has probably reached its maximum intensity and it is likely to weaken during the next two days.  Nanmadol is currently over water where the Sea Surface Temperature is near 27°C.  However, it has reached the upper level westerly in the middle latitudes and the vertical wind shear is increasing.  Nanmadol will weaken faster when it moves across Japan.

The westerly winds in the middle latitudes have turned Tropical Storm Nanmadol toward the north-northeast.  As Nanmadol moves farther north, the speed of the westerlies will increase and the tropical storm is forecast to move quickly toward the east-northeast across southern Japan.  On its anticipated track, Tropical Storm Nanmadol will reach Kyushu in a few hours.  Nanmadol will also move over Shikoku and Honshu.  Tropical Storm Nanmadol will bring a brief period of gusty winds and the potential for locally heavy rain when it moves across southern Japan.

Tropical Storm Nanmadol Brings Wind and Rain to Southern Ryukyu Islands

Tropical Storm Nanmadol brought wind and rain to the southern Ryukyu Islands on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Nanmadol was located at latitude 24.4°N and longitude 124.7°E which put it about 40 miles (65 km) east of Ishigaki, Japan.  Nanmadol was moving toward the north-northwest at 21 m.p.h. (34 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 998 mb.

The core of Tropical Storm Nanmadol continued to organize on Sunday.  A ring of thunderstorms wrapped tightly around the center of circulation.  Additional bands of showers and thunderstorms formed outside the core.  Thunderstorms were beginning to generate more upper level divergence which was pumping out mass in all directions.  The circulation of Tropical Storm Nanmadol was fairly small.  Winds to tropical storm force only extend out about 70 miles (110 km) from the center.

Tropical Storm Nanmadol will be in an environment that is very favorable for intensification for about another 24 hours.  Nanmadol will be moving over water where the Sea Surface Temperature (SST) is near 29°C.  The circulation of Tropical Storm Nanmadol is underneath the center of an upper level ridge and the upper level winds are very weak.  Warm SSTs and almost no vertical wind shear will permit Tropical Storm Nanmadol to intensify during the next day and there could be a period of rapid intensification.  Nanmadol could strengthen into a typhoon before it reaches a less favorable environment.  The tropical storm will move over cooler SSTs and it will move into an area of stronger upper level westerly winds in a couple of days.  Nanmadol will begin to weaken when that happens.

Tropical Storm Nanmadol is moving around the western end of a subtropical ridge which is steering it toward the north.  A general northward motion is expected to continue for about another 24 hours.  Nanmadol will reach the westerly winds in the middle latitudes in about a day and those winds will turn it toward the northeast.  On its anticipated track the center of Tropical Storm Nanmadol will pass west of Okinawa.  Nanmadol could approach Kyushu in about 36 hours.  Tropical Storm Nanmadol will continue to cause gusty winds and locally heavy rain over the southern Ryukyu Islands for another 12 to 24 hours.

Tropical Storm Nanmadol Forms Southeast of Taiwan

Tropical Storm Nanmadol formed southeast of Taiwan on Saturday.  At 8:00 p.m. EDT on Saturday the center of Tropical Storm Nanmadol was located at latitude 20.7°N and longitude 127.1°E which put it about 475 miles (765 km) southeast of Taipei, Taiwan.  Nanmadol was moving toward the northwest at 24 m.p.h. (35 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1002 mb.

A center of circulation consolidated rapidly on Saturday in an area of thunderstorms southeast of Taiwan.  A primary band of showers and thunderstorms wrapped around the northern and western side of the circulation.  Other bands of showers and thunderstorms developed in the northern half of the circulation.  The thunderstorms near the center began to generate upper level divergence which pumped out mass to the north of the tropical storm.

Tropical Storm Nanmadol will move through an area favorable for intensification during the next 24 hours.  Nanmadol will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge northeast of Nanmadol is producing southeasterly winds which are blowing toward the top of the tropical storm, but there is little vertical wind shear.  Tropical Storm Nanmadol is likely to intensify on Sunday.  When Nanmadol moves farther north, it will move over cooler water and it will be effected by the upper level westerly winds in the middle latitudes.  Cooler water and more vertical wind shear will cause Nanmadol to start to weaken at that time.

Tropical Storm Nanmadol is moving around the western end of a subtropical ridge which is steering it quickly toward the northwest.  Nanmadol will move in a general north-northwesterly direction on Sunday.  It will turn toward the northeast in 24 to 36 hours when it begins to be steered by the mid-latitude westerlies.  On its anticipated track Tropical Storm Nanmadol could approach the southernmost Ryukyu Islands including Ishigaki Jima in about 12 hours.  The center is expected to pass west of Okinawa.  Tropical Storm Nanmadol could approach Kyushu in a couple of days.  An intensifying Tropical Storm Nanmadol will bring gusty winds and locally heavy rain to the southernmost Ryukyu Islands.