Monthly Archives: September 2024

Tropical Storm Yagi Drops Heavy Rain on Northern Luzon

Tropical Storm Yagi dropped heavy rain on parts of northern Luzon on Monday.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Yagi was located at latitude 17.5°N and longitude 121.7°E which put the center about 25 miles (40 km) south of Tuguegarao, Philippines.  Yagi was moving toward the north-northwest at 9 m.p.h. (15 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 996 mb.

The center of Tropical Storm Yagi moved across northern Luzon on Monday.  Storms near the center of Yagi’s circulation dropped heavy rain on parts of northern Luzon.  There were reports that heavy rain caused floods and landslides in some locations.  There were also reports that the floods and landslides caused an unknown number of deaths.

The circulation around Tropical Storm Yagi weakened gradually as Yagi move across northern Luzon.  Thunderstorms were still occurring near the center of Yagi’s circulation.  Thunderstorms were also occurring in bands revolving around the center of circulation.  Storms near the center of Yagi generated upper level divergence that pumped mass away from the tropical storm.

Winds to tropical storm force extended out 70 miles (110 km) from the center of Tropical Storm Yagi.

Tropical Storm Yagi will move around the western part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Yagi toward the northwest during the next 24 hours.  On its anticipated track, the center of Tropical Storm Yagi will move over the South China Sea in 12 hours.  A second high pressure system that is over China will steer Yagi toward the west on Tuesday.

Tropical Storm Yagi will continue to weaken gradually during the next few hours while it moves across northern Luzon.  Yagi will move into an environment that will be favorable for intensification when it moves over the South China Sea.  Yagi will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the middle of an upper level ridge over the South China Sea.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Tropical Storm Yagi is likely to intensify after it moves over the South China Sea.  Yagi is likely to strengthen to a typhoon by the middle of the week.

Tropical Storm Yagi will continue to drop heavy rain over northern Luzon during the next few hours.  Heavy rain is likely to cause additional floods and landslides.

Tropical Cyclone Asna Weakens East of Oman

Tropical Cyclone Asna weakened over the northern Arabian Sea east of Oman on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Cyclone Asna was located at latitude 21.4°N and longitude 61.4°E which put the center about 185 miles (300 km) east-northeast of Masirah Island.  Asna was moving toward the southwest at 6 m.p.h. (10 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 994 mb.

Tropical Cyclone Asna moved into a large mass of dry air over the Arabian Sea east of Oman on Sunday.  The dry air caused the thunderstorms in Asna’s circulation to dissipate.  Tropical Cyclone Asna still had a well defined low level circulation on Sunday afternoon, but the circulation was very shallow.  Bands of showers and lower clouds were revolving around the center of Asna’s circulation.  However, there were no thunderstorms and there wasn’t any upper level divergence.

Tropical Cyclone Asna will move through an environment unfavorable for intensification during the next 24 hours.  Asna will move over water where the Sea Surface Temperatures are near 28°C.  However, it will remain within the large mass of dry air.  The dry air will prevent the formation of new thunderstorms.  Tropical Cyclone Asna will weaken during the next 24 hours as the low level circulation gradually dissipates.

Tropical Storm Yagi Forms Near the Northern Philippines

Tropical Storm Yagi formed near the northern Philippines on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Yagi was located at latitude 13.9°N and longitude 124.4°E which put the center about 40 miles (65 km) northeast of Virac, Philippines.  Yagi was moving toward the northwest at 13 m.p.h. (20 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 998 mb.

A low pressure system near the northern Philippines strengthened on Sunday morning and the Japan Meteorological Agency designated the system as Tropical Storm Yagi.  The center of Yagi’s circulation was near Catanduanes Island.  Thunderstorms were forming near the center of Tropical Storm Yagi.  However, the distribution of thunderstorms in Yagi was asymmetrical.  Thunderstorms were forming in bands in the western half of Yagi’s circulation.  Bands in the eastern half of Tropical Storm Yagi consisted primarily of showers and lower clouds.  Storms near the center of Yagi began to generate upper level divergence that pumped mass away from the tropical storm.

Tropical Storm Yagi will move through an environment that will be mostly favorable for intensification during the next 24 hours.  Yagi will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southern part of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Yagi’s circulation.  Those winds will cause moderate vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be enough to prevent Yagi from strengthening.  Tropical Storm Yagi is likely to intensify during the next 24 hours.

Tropical Storm Yagi will move around the western part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Yagi toward the north-northwest during the next 24 hours.  On its anticipated track, the center of Tropical Storm Yagi will move near the east coast of Luzon.  A second high pressure system that is over China will steer Yagi toward the west early next week.

Bands in the western side of Tropical Storm Yagi will drop heavy rain over parts of Luzon.  Heavy rain is likely to cause widespread flooding.