Tag Archives: 09S

Tropical Cyclone Grant Intensifies to Equivalent of Hurricane/Typhoon

Tropical Cyclone Grant intensified to the equivalent of a hurricane/typhoon on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Cyclone Grant was located at latitude 12.4°S and longitude 86.3°E which put the center about 1030 miles (1660 km) east-southeast of Diego Garcia.  Grant was moving toward the west-southwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 986 mb.

Tropical Cyclone Grant continued to intensify slowly on Saturday.  The circulation around Grant became more symmetrical.  Bands of showers and thunderstorms were revolving around the center of Grant’s circulation.  Storms near the center of Grant generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease slowly.

The circulation around Tropical Cyclone Grant continued to be small. Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of Grant’s circulation.  Winds to tropical storm force extended out 60 miles (95 km) from the center of Tropical Cyclone Grant.

Tropical Cyclone Grant will move through an environment somewhat favorable for intensification during the next 24 hours.  Grant will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the western part of an upper level ridge over the South Indian Ocean.  The upper level ridge will produce northeasterly winds that will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear may not be enough to prevent intensification.  Tropical Cyclone Grant is likely to continue to intensify during the next 24 hours.

Tropical Cyclone Grant will move around the northern side of a high pressure system over the South Indian Ocean.  The high pressure system will steer Grant toward the west-southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Grant will pass south of Diego Garcia in three days.

Tropical Cyclone Grant Churns West

Tropical Cyclone Grant continued to churn westward over the South Indian Ocean on Friday.  At 10:00 p.m. EST on Friday the center of Tropical Cyclone Grant was located at latitude 11.8°S and longitude 89.7°E which put the center about 460 miles (740 km) west of the Cocos Islands.  Grant was moving toward the west at 9 m.p.h. (15 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 989 mb.

Tropical Cyclone Grant strengthened a little more on Friday.  Even though Grant strengthened, the structure of its circulation did not change much.  Thunderstorms were still occurring near the center of Grant’s circulation.  Thunderstorms were also occurring in bands in the southern and western parts of Tropical Cyclone Grant.  Bands in the northern and eastern part of Grant’s circulation consisted primarily of showers and lower clouds.  Storms near the center of Grant generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease slowly.

The circulation around Tropical Cyclone Grant continued to be small.  Winds to tropical storm force extended out 50 miles (80 km) from the center of Grant’s circulation.

Tropical Cyclone Grant will move through an environment somewhat favorable for intensification during the next 24 hours.  Grant will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the northwestern part of an upper level ridge over the South Indian Ocean.  The upper level ridge will produce northeasterly winds that will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear may not be enough to prevent intensification.  Tropical Cyclone Grant could intensify a little more during the next 24 hours.  Grant could strengthen to the equivalent of a hurricane/typhoon during the weekend.

Tropical Cyclone Grant will move around the northern side of a high pressure system over the South Indian Ocean.  The high pressure system will steer Grant toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Grant will pass south of Diego Garcia in four days.

Tropical Cyclone Grant Moves West of Cocos Islands

Tropical Cyclone Grant moved west of the Cocos Islands on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Grant was located at latitude 12.4°S and longitude 93.0°E which put the center about 235 miles (380 km) west of the Cocos Islands.  Grant was moving toward the west at 9 m.p.h. (15 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. (120 km/h).  The minimum surface pressure was 993 mb.

Tropical Cyclone Grant strengthened a little on Thursday as is moved west of the Cocos Islands.  Thunderstorms were occurring near the center of Grant’s circulation.  Thunderstorms were also occurring in bands in the southern and western parts of Tropical Cyclone Grant.  Bands in the northern and eastern part of Grant’s circulation consisted primarily of showers and lower clouds.  Storms near the center of Grant generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease slowly.

The circulation around Tropical Cyclone Grant continued to be small.  Winds to tropical storm force extended out 70 miles (110 km) from the center of Grant’s circulation.

Tropical Cyclone Grant will move through an environment somewhat favorable for intensification during the next 24 hours.  Grant will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the northwestern part of an upper level ridge over the South Indian Ocean.  The upper level ridge will produce northeasterly winds that will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear may not be enough to prevent intensification.  Tropical Cyclone Grant could intensify a little more during the next 24 hours.

Tropical Cyclone Grant will move around the northern side of a high pressure system over the South Indian Ocean.  The high pressure system will steer Grant toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Grant will move farther from the Cocos Islands.  Grant is likely to pass south of Diego Garcia in a few days.

Tropical Cyclone Grant Brings Wind and Rain to Cocos Islands

Tropical Cyclone Grant brought wind and rain to the Cocos Islands on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Grant was located at latitude 11.9°S and longitude 96.2°E which put the center about 35 miles (55 km) northwest of the Cocos Islands.  Grant was moving toward the west at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 995 mb.

A weather station in the Cocos Islands measured a wind gust of 63 m.p.h. (102 km/h).  The weather station also recorded 4.96 inches (126 mm) of rain.

The Australian Bureau of Meteorology cancelled the Warning for the Cocos Islands when Tropical Cyclone Grant began to move away on Wednesday evening.

Tropical Cyclone Grant began to intensify on Wednesday evening as it started to move west of the Cocos Islands.  The inner end of a rainband wrapped around the southern side of the center of Grant’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Grant.  Storms near the center of Grant generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Grant continued to be very small.  Winds to tropical storm force extended out 60 miles (95 km) from the center of Grant’s circulation.

Tropical Cyclone Grant will move through an environment favorable for intensification during the next 24 hours.  Grant will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the northern part of an upper level ridge over the South Indian Ocean.  The upper level ridge will produce easterly winds that will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  Tropical Cyclone Grant will intensify during the next 24 hours.

Tropical Cyclone Grant will move around the northern side of a high pressure system over the South Indian Ocean.  The high pressure system will steer Grant toward the west during the next 24 hours. On its anticipated track, Tropical Cyclone Grant will move away to the west of the Cocos Islands during the next 24 hours.

Tropical Cyclone Grant Nears Cocos Islands

Tropical Cyclone Grant was nearing the Cocos Islands on Tuesday evening.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Grant was located at latitude 12.0°S and longitude 98.0°E which put the center about 85 miles (135 km) east of the Cocos Islands.  Grant was moving toward the west at 7 m.p.h. (11 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 997 mb.

The Australian Bureau of Meteorology issued a Warning for the Cocos Islands.

Tropical Cyclone Grant maintained its intensity on Tuesday.   Thunderstorm activity weakened early during the day.  However, more thunderstorms developed in Tropical Cyclone Grant on Tuesday evening.  Thunderstorms near the center of Grant’s circulation began to generate more upper level divergence.  More upper level divergence will pump more mass away from the tropical cyclone.

The circulation around Tropical Cyclone Grant continued to be very small.  Winds to tropical storm force extended out 60 miles (95 km) from the center of Grant’s circulation.

Tropical Cyclone Grant will move through an environment favorable for intensification during the next 24 hours.  Grant will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the northern part of an upper level ridge over the South Indian Ocean.  The upper level ridge will produce easterly winds that will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  Tropical Cyclone Grant will intensify during the next 24 hours.

Tropical Cyclone Grant will move around the northern side of a high pressure system over the South Indian Ocean.  The high pressure system will steer Grant toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Grant will move over the Cocos Islands during the next 24 hours.

Tropical Cyclone Grant will bring strong winds and locally heavy rain to the Cocos Islands.  Heavy rain could cause flash floods.

Tropical Cyclone Grant Develops East of Cocos Islands

Tropical Cyclone Grant developed over the South Indian Ocean east of the Cocos Islands on Monday.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Grant was located at latitude 12.5°S and longitude 99.8°E which put the center about 210 miles (340 km) east of the Cocos Islands.  Grant was moving toward the west at 7 m.p.h. (11 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 997 mb.

The Australian Bureau of Meteorology issued a Watch for the Cocos Islands.

A low pressure system over the South Indian Ocean east of the Cocos Islands strengthened on Monday and the Australian Bureau of Meteorology designated the system as Tropical Cyclone Grant.

More thunderstorms formed near the center of Tropical Cyclone Grant on Monday.  Thunderstorms also developed in bands revolving around the center of Grant’s circulation.  Storms near the center of Grant generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Grant was small.  Winds to tropical storm force extended out 60 miles (95 km) from the center of Grant’s circulation.

Tropical Cyclone Grant will move through an environment favorable for intensification during the next 24 hours.  Grant will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the northern part of an upper level ridge over the South Indian Ocean.  The upper level ridge will produce easterly winds that will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  Tropical Cyclone Grant will intensify during the next 24 hours.

Tropical Cyclone Grant will move around the northern side of a high pressure system over the South Indian Ocean.  The high pressure system will steer Grant toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Grant will reach the Cocos Islands in less than 48 hours.

Tropical Cyclone Grant will bring strong winds and locally heavy rain to the Cocos Islands.  Heavy rain could cause flash floods.

Anggrek Transitions to an Extratropical Cyclone

Former Tropical Cyclone Anggrek made a transition to an extratropical cyclone over the South Indian Ocean during Tuesday night. At 4:00 a.m. EST on Wednesday the center of former Tropical Cyclone Anggrek was located at latitude 33.3°S and longitude 84.8°E which put it about 1925 miles (3105 km) south-southeast of Diego Garcia. Anggrek was moving toward the east-southeast at 40 m.p.h. (65 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 983 mb.

Former Tropical Cyclone Anggrek made a transition to a powerful extratropical cyclone over the South Indian Ocean. Anggrek moved over water where the Sea Surface Temperatures are near 22°C. It moved under the eastern side of an upper level trough that is east of Madagascar. The upper level trough produced northwesterly winds that caused strong vertical wind shear. The combination of colder water and strong wind shear caused formal Tropical Cyclone Anggrek to make a transition to an extratropical cyclone.

The transition to an extratropical cyclone also caused changes to the structure of former Tropical Cyclone Anggrek. The strong northwesterly winds in the upper levels of the atmosphere blew the tops off of many of the thunderstorms in Anggrek’s circulation. Thunderstorms were still occurring in bands in the southern part of former Tropical Cyclone Anggrek. Bands in the northern part of the circulation consisted primarily of showers and lower clouds. Winds to hurricane/typhoon force extended out 70 miles (110 km) in the eastern side of former Tropical Cyclone Anggrek. Winds to tropical storm force extended out 140 miles (220 km) from the center of Anggrek’s circulation.

The upper level trough east of Madagascar will steer former Tropical Cyclone Anggrek quickly toward the east-southeast. On its anticipated track, Former Tropical Cyclone Anggrek could approach southwestern Australia later this week.

Elsewhere over the South Indian Ocean, a tropical depression formed east of Rodrigues. At 10:00 a.m. EST on Wednesday the center of the tropical depression was located at latitude 19.9°S and longitude 66.2°E which put it about 175 miles (280 km) east of Port Mathurin, Rodrigues. The tropical depression was moving toward the south-southeast at 3 m.p.h. (5 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 996 mb.

Tropical Cyclone Enawo Hits Madagascar

Powerful Tropical Cyclone Enawo made landfall on the coast of northeastern Madagascar near Ambohitralanana on Tuesday.  Tropical Cyclone Enawo was the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale when it made landfall.  At 10:00 p.m. EST on Tuesday the center of Tropical Cyclone Enawo was located near latitude 15.5°S and longitude 49.2°E which put it near Mandritsara, Madagascar.  Enawo was moving toward the southwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 980 mb.

Even though the center has been over land for more than 12 hours the circulation of Tropical Cyclone Enawo is still very well organized.  The structure is very symmetrical and there are multiple bands of thunderstorms revolving around the center of circulation.  The strongest winds are occurring in the portions of the rainbands that are over the Indian Ocean.  The circulation of Tropical Cyclone Ewano is still very large and winds to tropical storm force extend out about 200 miles (320 km) from the center.  Thunderstorms near the core of the circulation are generating upper level divergence which is pumping out mass in all directions.

The circulation of Tropical Cyclone Enawo will continue to weaken on Wednesday because the center is over land.  However, the atmospheric environment is favorable for a tropical cyclone.  The upper level winds are weak and there is very little vertical wind shear.  The lack of wind shear will cause the circulation of Tropical Cyclone Enawo to spin down more slowly and it is likely to persist for several more days.

Tropical Cyclone Enawo is moving around the western end of a subtropical high pressure system which is steering the tropical cyclone toward the southwest.  Tropical Cyclone Enawo is likely to turn more toward the south on Wednesday as it reaches the western end of the subtropical high.  On its anticipated track Tropical Cyclone Enawo will move over the center of Madagascar and it could pass near Antananarivo in 24 to 36 hours.  Tropical Cyclone Enawo is producing very heavy rainfall and flash flooding is a serious risk in areas of steep terrain.

Powerful Tropical Cyclone Enawo Nears Madagascar

Powerful Tropical Cyclone Enawo neared Madagascar late on Monday.  At 11:00 p.m. EST on Monday the center of Tropical Cyclone Enawo was located at latitude 14.7°S and longitude 51.1°E which put it about 140 miles (225 km) northeast of Mananara, Madagascar.  Enawo was moving toward the west-southwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 175 m.p.h. (285 km/h).  The minimum surface pressure was 931 mb.

Tropical Cyclone Enawo intensified rapidly on Monday and it is now the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  The circulation of Tropical Cyclone Enawo is very well organized.  There is an circular eye with a diameter of 30 miles (50 km) at the center of the circulation.  The eye is surround by a ring of strong thunderstorms and the strongest winds are occurring in the eyewall.  The remainder of the circulation is symmetrical and additional well formed bands of thunderstorms are revolving around the core of the circulation.  Winds to hurricane force extend out about 70 miles (110 km) from the center.  Winds to tropical storm force extend out about 220 miles (350 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Enawo is 29.9.  The Hurricane Size Index (HSI) is 25.0 and the Hurricane Wind Intensity Size Index (HWISI) is 54.9.  The indices indicate that Tropical Cyclone Enawo is capable of causing significant widespread wind damage.  Tropical Cyclone Enawo is as intense as Hurricane Katrina was just before it made landfall in the coast of Mississippi in 2005.  Enawo is a little smaller than Hurricane Katrina was when Katrina was moving across the Gulf of Mexico in 2005.

Tropical Cyclone Enawo is moving through a very favorable environment.  Enawo is moving over water where the Sea Surface Temperature is near 29°C.  The upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Enawo is likely to maintain its intensity until it reaches the coast of Madagascar in a few hours.  Enawo will weaken after the center moves inland.

A subtropical ridge is steering Tropical Cyclone Enawo a little to the south of due west and that general motion is expected to continue for another 12 to 24 hours.  Tropical Cyclone Enawo will move near the western end of the subtropical ridge in another day or so and it will start to move more toward the south when it nears the end of the ridge.  On its anticipated track Tropical Cyclone Enawo will make landfall on the northeast coast of Madagascar near Ambohitralanana in a few hours.

Tropical Cyclone Enawo is a dangerous storm.  It is capable of causing widespread significant wind damage when it moves over eastern Madagascar.  The strong winds will also drive water toward the coast and Tropical Cyclone Enawo will generate a significant storm surge near where the center makes landfall.  Enawo will produce very heavy rain and significant inland flooding could occur if rainfall exceeds the capacity of rivers and streams.

Tropical Cyclone Enawo Moves Toward Madagascar and Strengthens

Tropical Cyclone Enawo moved toward Madagascar and strengthened on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Enawo was located at latitude 14.0°S and longitude 54.1°E which put it about 340 miles (550 km) east-northeast of Mananara, Madagascar.  Enawo was moving toward the west at 7 m.p.h.  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (205 km/h).  The minimum surface pressure was 961 mb.

The circulation of Tropical Cyclone Enawo is very well organized.  A circular eye is at the center of circulation.  The eye is surrounded by a ring of thunderstorms.  Additional bands of showers and thunderstorms are revolving around the core of the circulation.  The circulation is very symmetrical although there are more thunderstorms in the northwestern quadrant of the circulation.  Thunderstorms in the core of the circulation are generating upper level divergence which is pumping mass away from the tropical cyclone.

The size of the circulation of Tropical Cyclone Enawo increased on Sunday.  Winds to hurricane force extend out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extend out about 250 miles (400 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Enawo is 17.8.  The Hurricane Size Index (HSI) is 17.8 and the Hurricane Wind Intensity Size Index (HWISI) is 35.6.  These indices indicated that Tropical Cyclone Enawo is capable of causing serious wind damage on a regional scale.

Tropical Cyclone Enawo will continue to move through an favorable environment.  It will move over water where the Sea Surface Temperature is near 29°C.  The upper level winds are weak and there is little vertical wind shear.  Tropical Cyclone Enawo will continue to intensify during the next 24 hours and it could become the equivalent of a major hurricane.

A subtropical ridge is steering Tropical Cyclone Enawo toward the west and a general west or west-southwest motion is expected to continue during the next several days.  On its anticipated track Tropical Cyclone Enawo will approach the coast of Madagascar in about 36 hours.  Enawo will be capable of causing serious wind damage.  It will also generate a storm surge along the coast.  Tropical Cyclone Enawo will produce very heavy rain and a potential for flooding over eastern and southern Madagascar.