Tag Archives: Tropical Storm Fengshen

Tropical Storm Fengshen Prompts Typhoon Warning for Northern Marianas

Tropical Storm Fengshen prompted the National Weather Service Office in Guam to issue a Typhoon Warning for portions of the Northern Marianas on Wednesday night.  At 10:00 a.m. EST on Wednesday the center of Tropical Storm Fengshen was located at latitude 17.2°N and longitude 149.0°E which put it about 265 miles (430 km) east of Alamagan.  Fengshen was moving toward west at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (129 km/h).  The minimum surface pressure was 991 mb.

A Typhoon Warning was in effect for Alamagan, Pagan and Agrihan.

Tropical Storm Fengshen strengthened slowly on Wednesday, although the thunderstorm activity fluctuated during the day.  More thunderstorms developed near the center of circulation on Wednesday night.  Those thunderstorms were generating some upper level divergence which was pumping mass away to the west of the tropical storm.  The strongest rainbands were in the southern and eastern parts of Fengshen.  Bands in the northern wand western parts of the circulations consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

The circulation around Tropical Storm Fengshen may have pulled drier air into the tropical storm.  The drier air may have mixed into rainbands in the northern and western parts of Fengshen and caused the thunderstorms in those parts of the tropical storm to weaken.  Tropical Storm Fengshen will move through an environment favorable for intensification during the next several days.  Fengshen will move over water where the Sea Surface Temperature is near 29°C.  It will move south of an upper level ridge centered south of Japan.  The ridge will produce northeasterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear.  The wind shear and drier air will slow the rate of intensification.  Tropical Storm Fengshen could strengthen into a typhoon within 24 hours.

The ridge south of Japan will steer Tropical Storm Fengshen toward the west for another 12 to 24 hours.  Fengshen will start to move toward the north when it reaches the western end of the ridge.  On its anticipated track Tropical Storm Fengshen could reach Alamagan, Pagan and Agrihan in about 12 hours.  Fengshen could be a typhoon at that time.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Kalmaegi moved slowly toward northern Luzon.  At 10:00 p.m. EST on Wednesday the center of Tropical Storm Kalmaegi was located at latitude 14.3°N and longitude 127.2°E which put it about 425 miles (685 km) east-southeast of Baler, Philippines.  Kalmaegi was moving toward northwest at 12 m.p.h. (19 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.

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.

Tropical Storm Fengshen Forms East of Northern Marianas

Tropical Storm Fengshen formed east of the Northern Marianas on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Fengshen was located at latitude 17.1°N and longitude 157.1°E which put it about 805 miles (1300 km) east of Saipan.  Fengshen was moving toward the west-northwest at 18 m.p.h. (30 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 1000 mb.

More thunderstorms developed near the center of a cluster of thunderstorms east of the Northern Marianas on Tuesday and the Japan Meteorological Society designated the system as Tropical Storm Fengshen.  The distribution of thunderstorms around Tropical Storm Fengshen was asymmetrical.  Stronger thunderstorms were occurring in bands in the western half of the circulation.  Bands in the eastern half of the tropical storm consisted primarily of showers and lower clouds.  Fengshen was moving south of an upper level ridge over the Western North Pacific Ocean.  The ridge was producing easterly winds which were causing moderate vertical wind shear.  The wind shear was contributing to the asymmetrical distribution of thunderstorms.

Tropical Storm Fenshen will move through an environment favorable for intensification during the next several days.  Fengshen will move over water where the Sea Surface Temperature is near 29°C.  The upper level ridge will continue to cause vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be strong enough to prevent intensification.  Tropical Storm Fengshen will intensify gradually and it could strengthen into a typhoon during the next two to three days.

Tropical Storm Fengshen will move around the western end of the ridge over the Western North Pacific.  The ridge will steer Fengshen toward the west-northwest during the next 24 to 36 hours.  Tropical Storm Fengshen will move more toward the north in about 36 hours when it reaches the western end of the ridge.  On its anticipated track Fengshen will pass northeast of the Northern Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 27W developed east of Luzon.  At 4:00 p.m. EST on Tuesday the center of Tropical Depression 27W was located at latitude 12.1°N and longitude 130.9°E which put it about 315 miles (510 km) east of Laoang, Philippines.  The depression was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1004 mb.