Monthly Archives: December 2019

Tropical Cyclone 06A Forms over Western Arabian Sea

Tropical Cyclone 06A formed over the western Arabian Sea on Monday night.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone 06A was located at latitude 6.7°N and longitude 56.1°E which put it about 420 miles (620 km) east-southeast of Eyl, Somalia.  The tropical cyclone was moving toward the west-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 1003 mb.

The circulation around Tropical Cyclone 06A was still organizing on Monday night and the distribution of thunderstorms was asymmetrical.  Many of the stronger thunderstorms were occurring in bands in the northern half of the circulation.  Bands in the southern half of the circulation consisted primarily of showers and lower clouds.  Satellite images suggested that the upper levels of the circulation were tilted to the north of the surface circulation.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

Tropical Cyclone 06A was near the western end of an upper level ridge centered over southern India.  The ridge was producing southerly winds which were blowing toward the top of the tropical cyclone.  Those winds were causing moderate vertical wind shear,  The wind shear was causing the apparent tilt of the circulation with height and it was contributing to the asymmetrical distribution of thunderstorms.

Tropical Cyclone 06A will move through an environment that will be somewhat favorable for intensification.  The tropical cyclone will move over water where the Sea Surface Temperature is near 29°C.  The upper level ridge will continue to cause moderate vertical wind shear during the next several days.  The wind shear will inhibit intensification.  If the vertical wind shear remains moderate, Tropical Cyclone 06A could continue to intensify slowly.  However, if the wind shear increases, then the shear could be strong enough to weaken the tropical cyclone.  The forecast is for slight intensification of Tropical Cyclone 06A during the next 24 to 36 hours.

The ridge centered over southern India will steer Tropical Cyclone 06A toward the north during the next day or two.  On its anticipated track Tropical Cyclone 06A will move parallel to the coast of Somalia during the next 24 to 36 hours.  The tropical cyclone could turn toward Somalia later this week, but there is much uncertainty about the longer range forecast because of uncertainty about the future intensity of Tropical Cyclone 06A.

Major Typhoon Kammuri Makes Landfall on Southeastern Luzon

Major Typhoon Kammuri made landfall on southeastern Luzon near Sorsogon and Legaspi on Monday.  At noon EST on Monday the center of Typhoon Kammuri was located at latitude 13.2°N and longitude 123.6°E which put it about 10 miles (15 km) west of Legaspi, Philippines and about 230 miles (370 km) east-southeast of Manila.  Kamuri was moving toward the west at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 950 mb.

Typhoon Kammuri rapidly intensified into the equivalent of a major hurricane during the 12 hours prior to landfall on Monday.  A large eye with a diameter to 50 miles (80 km) developed at the center of Kammuri.  A thick ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of the typhoon.  Storms near the core generated strong upper level divergence which pumped mass away from the typhoon in all directions.  The removal of large amounts of mass allowed the surface pressure to decrease more quickly.

Typhoon Kammuri also grew larger as it got stronger.  Winds to typhoon force extended out about 50 miles (80 km) in most portions of Kammuri, but those strong winds extended out 90 miles (145 km) in the northwestern part of the circulation.  Winds to tropical storm force extended out 175 miles (280 km) in most parts of the circulation, but they extended out 300 miles (480 km) to the northwest of the center of Kammuri.  The Hurricane Intensity Index (HII) for Typhoon Kammuri was 25.1.  The Hurricane Size Index (HSI) was 25.4 and the Hurricane Wind Intensity Size Index (HWISI) was 50.5.  Typhoon Kammuri was capable of causing widespread major damage to southern Luzon.

Typhoon Kammuri will move south of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Kammuri toward the west-northwest during the next 36 to 48 hours.  On its anticipated track Typhoon Kammuri will move across southeastern Luzon and over the Sibuyan Sea during the next few hours.  The center of Kammuri is forecast to pass south of Manila in 18 to 24 hours.

Typhoon Kammuri will weaken slowly as it moves across southeastern Luzon.  Kammuri will bring strong winds and heavy rain to southern Luzon.  Typhoon Kammuri will also have a big impact on Burias, Marinduque Island and Mindoro.  Kammuri could produce winds to near typhoon force around Manila.  Typhoon Kammuri is likely to cause major damage around Legaspi.  Locally heavy rain could produce flash floods in numerous locations.  Kammuri could cause serious damage around Manila.

Typhoon Kammuri Strengthens As It Nears Southeast Luzon

Typhoon Kammuri strengthened as it neared southeast Luzon on Sunday night.  At 10:00 p.m. EST on Sunday the center of Typhoon Kammuri was located at latitude 13.0°N and longitude 126.0°E which put it about 385 miles (625 km) east- southeast of Manila, Philippines and about 160 miles (260 km) east of Legaspi.  Kammuri was moving toward the west at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 959 mb.

Typhoon Kammuri strengthened on Sunday.  An ellipitical eye with a mean radius of 30 miles (50 km) cleared out at the center of circulation.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Kammuri.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  The removal of mass allowed the surface pressure to decrease.

The wind field around Typhoon Kammuri became more symmetrical on Sunday.  Winds to typhoon force extended out 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out 180 miles (290 km) from the center.  The Hurricane Intensity Index (HII) was 17.8.  The Hurricane Size Index (HSI) was 19.3 and the Hurricane Wind Intensity Size Index (HWISI) was 37.1.  Typhoon Kammuri was capable of causing serious damage.

Typhoon Kammuri will move through an environment favorable for intensification during the next 12 hours.  Kammuri will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Kammuri could strengthen into the equivalent of a major hurricane before it reaches southeastern Luzon.  Kammuri will start to weaken after the center moves over land.

Typhoon Kammuri will move south of a high pressure system over the Western North Pacific Ocean.  The high will steer Kammuri toward the west during the next several days.  On its anticipated track the center of Typhoon Kammuri will pass between Samar and Catanduanes Island before making landfall near Sorsogon on southeast Luzon.  The center of Kammuri will pass near Legaspi, Tabaco and Ligao.

Typhoon Kammuri will be capable of causing major damage in the Philippines.  Kammuri will bring strong winds to southeast Luzon.  Typhoon Kammuri could also produce winds to near typhoon force in Virac on Catanduanes Island.  Kammuri could produce a storm surge of up to 10 feet (3 meters) in locations where the wind blows water toward the coast.  Typhoon Kammuri will drop locally heavy rain over southern Luzon.  Flash floods could occur, especially in areas of steeper slopes.

Typhoon Kammuri Moves Closer to the Philippines

Typhoon Kammuri moved closer to the Philippines on Saturday.  At 10:00 p.m. EST on Saturday the center of Typhoon Kammuri was located at latitude 13.2°N and longitude 130.5°E which put it about 685 miles (1100 km) east of Manila, Philippines.  Kammuri was moving toward the west at 19 m.p.h. (29 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 110 m.p.h. (175 km/h).  The minimum surface pressure was 970 mb.

Typhoon Kammuri appeared to be getting better organized on Saturday night.  Visible satellite images of Kammuri  suggested that an eye was clearing out at the center of the typhoon.  The inner end of a rainband wrapped around much of the developing eye.  There was still a gap on the northwestern side of the eyewall, but the gap was getting smaller.  Bands of showers and thunderstorms were revolving around the more organized core of Typhoon Kammuri.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.

Winds to typhoon force extended out 50 miles from the center of circulation in the northern half of Typhoon Kammuri and out 25 miles in the southern side of the typhoon.  Winds to tropical storm force extended out 220 miles (355 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Kammuri was 13.9.  The Hurricane Size Index (HSI) was 17.0 and the Hurricane Wind Intensity Size Index (HWISI) was 30.9.

Typhoon Kammuri will move through an environment favorable for intensification during the next 36 hours.  Kammuri will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Kammuri will intensify and it could strengthen into the equivalent of a major hurricane.  Intensification could be more rapid once an eye and eyewall are full formed.

Typhoon Kammuri will move south of a high pressure system that extends from eastern Asia to the Western North Pacific Ocean.  The high will steer Kammuri toward the west during the next three days.  On its anticipated track Typhoon Kammuri could approach Catanduanes Islands and southeastern Luzon in about 36 hours.  Kammuri could be the equivalent of a major hurricane at that time.