Tropical Storm Kalmaegi Forms East of Luzon

Tropical Storm Kalmaegi formed east of Luzon on Tuesday night.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Kalmaegi was located at latitude 12.9°N and longitude 128.8°E which put it about 350 miles (565 km) east of Legaspi, Philippines.  Kalmaegi was moving toward the west-northwest at 15 m.p.h. (24 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.

The Japan Meteorological Agency determined that former Tropical Depression 27W strengthened into Tropical Storm Kalmaegi on Tuesday night.  The circulation Kalmaegi was not well organized.  There was a large, broad area of low pressure, but there were few thunderstorms near the center of circulation.  Most of the stronger thunderstorms were occurring in bands in the northwestern part of Tropical Storm Kalmaegi.  Bands in the other portions of the circulation consisted primarily of showers and lower clouds.

Tropical Storm Kalmaegi will move through an environment marginally favorable for intensification.  Kalmaegi will move over water where the Sea Surface Temperature is near 29°C.  So, there is plenty of energy in the upper layer of the Western North Pacific Ocean to support intensification.  However, Tropical Storm Kalmaegi will move around the southwestern part of an upper level ridge centered south of Japan on Wednesday.  The ridge will produce northeasterly winds which will blow across the eastern part of the tropical storm.  Those winds will cause moderate vertical wind shear and they will inhibit intensification.  In 12 to 24 hours Kalmaegi will move closer to the western end of the ridge and the upper level winds will blow from the south.  The wind shear could decrease when the wind direction changes, which may allow the tropical storm to strengthen.

The ridge south of Japan will steer Tropical Storm Kalmaegi toward the northwest during the next 48 hours.  On its anticipated track Tropical Storm Kalmaegi could approach northeastern Luzon in 48 to 72 hours.  Since the strongest thunderstorms are in the northwestern part of Kalmaegi, the tropical storm could drop locally heavy rain over Luzon even if the center does not make landfall.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Fengshen continued to organize east of the Northern Marianas.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Fengshen was located at latitude 17.4°N and longitude 155.3°E which put it about 690 miles (1115 km) east-northeast of Saipan.  Fengshen was moving toward the west-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 wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1002 mb.