Tropical Cyclone Eunice strengthened rapidly on Thursday as it moved over the South Indian Ocean and it has attained an intensity equivalent to that of a Category 5 hurricane on the Saffir-Simpson Scale. At 8:00 p.m. EST on Thursday the center of Eunice was located at latitude 17.7°S and longitude 67.7°E, which put it about 780 miles south-southwest of Diego Garcia. It was moving toward the south-southeast at 10 m.p.h. The maximum sustained wind speed was 160 m.p.h. and it was estimate that there were wind gusts to 185 m.p.h. The minimum surface pressure was 918 mb.
Eunice has been in an environment very conducive for rapid intensification. It has moved over warm Sea Surface Temperatures and upper level winds have been quite light. As a result deep convection has been ongoing around the core of the circulation and upper level outflow has pumped out large quantities of mass. Those processes caused the pressure to decrease rapidly and the wind speeds increased in a corresponding manner. Eunice will remain in a favorable environment for another day or so. After that time it will move to a higher latitude, which will place it in an area of lower Sea Surface Temperatures and more vertical wind shear. Eunice is likely to weaken without threatening any land area.
The center of Tropical Cyclone Niko is passing east of Tahiti. At 11:00 p.m. EST on Wednesday the center of Tropical Cyclone Niko was located at latitude 17.8°N and longitude 147.9°E which put it about 120 miles east of Papeete, Tahiti. Niko was moving toward the south-southeast at 13 m.p.h. The maximum sustained wind speed was 60 m.p.h. and there were gusts to 75 m.p.h. The minimum surface pressure was estimated to be 985 mb.
Niko is a small tropical cyclone and even though it is passing within 120 miles of Tahiti, it is having a minimal effect on the weather there. A subtropical ridge is expected to continue to steer Niko south-southeasterly direction, which will carry it away from Tahiti, although it could come close to the island of Mehetia. The north-northwesterly winds that are steering Niko are also creating some wind shear. The wind shear is limiting the intensification of Niko, but it is still over warm Sea Surface Temperatures and some intensification is possible on Thursday. By Friday Niko is likely to be far enough south that is will start to move over cooler Sea Surface Temperatures and encounter stronger upper level winds. So, Niko is likely to start to weaken in about 36 to 48 hours.
A small cluster of thunderstorms north of Tahiti organized rapidly on Tuesday and it has now been classified as Tropical Cyclone Niko. At 7:00 p.m. EST on Tuesday the center of Tropical Cyclone Niko was centered at latitude 14.1°S and longitude 150.2°W which put it about 250 miles north-northwest of Papeete, Tahiti and about 220 miles northeast of Bora-Bora. Niko was moving toward the south-southeast at 8 m.p.h. The maximum sustained wind speed was 50 m.p.h. and there were gusts to 65 m.p.h. The minimum surface pressure was estimated to be 989 mb.
The circulation around Niko is small and winds to tropical storm force only extend about 80 miles from the center. The small circulation is in an area of lighter winds in the upper levels. The modest wind shear allowed thunderstorms to develop rapidly around the center of circulation and Niko organized quickly during the past 12 hours. Niko is currently over warm Sea Surface Temperatures and it is in an environment favorable for intensification. Small tropical cyclones can intensify rapidly and Niko has the potential to do so during the next 24 hours. It could reach typhoon intensity on Wednesday.
A combination of a near equatorial ridge and a subtropical ridge are steering Niko in a south-southeasterly direction and this general motion is expected to continue. The projected path takes the center of Niko east of Tahiti. However, it could move near some smaller islands including Mataiva, Makate, and Tikehau. Given the small size of the circulation, the area of damage is likely to be limited, but any place getting hit directly by the center of circulation could see wind damage.
Tropical Storm Mekkhala is moving through the northern Philippines. At 11:00 p.m. EST on Saturday the center of Tropical Storm Mekkhala was located at latitude 13.9°N and longitude 123.0°E which put it near Daet and about 150 miles east-southeast of Manilla. Mekkhala was moving toward the northwest at 11 m.p.h. The maximum sustained wind speed was 40 m.p.h. and there were gusts to 50 m.p.h. The minimum surface pressure was 996 mb.
Mekkhala crossed over northern parts of Samar on Saturday and the center is near the southeastern portion of Luzon. The islands disrupted parts of the circulation in the lower levels and Mekkhala weakened throughout the day. Thunderstorms have been redeveloping in the part of the circulation over Lamon Bay and Mekkhala continues to be a tropical storm. Divergence continues in the upper portion of the circulation and the wind shear remains at a moderate level. While the atmospheric and oceanic environment would support intensification, if the center moves across Luzon further weakening is likely.
Mekkhala is near the western end of a subtropical ridge which has been steering the system toward the northwest. If deep convection continues, then the ridge could continue to steer it toward the northwest. However, if the system weakens to the point where only shallow convection exists, then it could be steered more toward the west by the lower level flow.
The relatively slow movement of Mekkhala continues the potential for locally heavy rainfall, flooding and mudslides.
Tropical Storm Mekkhala intensified rapidly on Friday and it has reached typhoon intensity. At 3:00 p.m. EST on Friday the center of Mekkhala was located at latitude 10.9°N and longitude 127.5°E which put it about 280 miles east of Tacloban and about 500 miles east-southeast of Manila, Philippines. Mekkhala was moving toward the west-southwest at 11 m.p.h. The maximum sustained wind speed was 75 m.p.h. and there were wind gusts to 90 m.p.h. The minimum surface pressure was 974 mb.
The speed of the upper level east-southeasterly winds blowing over the top of Mekkhala weakened on Friday and the vertical shear affecting the circulation decreased. The combination of less vertical wind shear and warm Sea Surface Temperatures allowed convection to develop all around the core of the circulation. Strong thunderstorms near the center of Mekkhala created upper level divergence and the storm intensified rapidly into a typhoon. Mekkhala remains in a favorable environment and further intensification is possible before it reaches the Philippines. Once the center of circulation beings to move over the islands, interaction with land will weaken it.
A strengthening subtropical ridge has been steering Mekkhala a little south of due west and that motion is expected to continue in the short term. The typhoon could reach the Philippines in about 12 hours. Mekkhala could turn more toward the west-northwest as it crosses the Philippines and reaches the western end of the subtropical ridge.
Since Mekkhala has intensified into a typhoon the potential risks now include wind damage, and storm surge in addition to locally heavy rainfall, flooding and mudslides.
Tropical Cyclone Chedza is moving across the central portion of Madagascar. At 3:00 p.m. EST the center of Chedza was located at latitude 20.4°N and longitude 44.7°E which put it near Belo Tsiribihina. It was moving toward the east-southeast at 10 m.p.h. The maximum sustained wind speed was 45 m.p.h. and there were gusts to 55 m.p.h. The minimum surface pressure was 996 mb.
Low vertical wind shear and warm Sea Surface Temperatures created an environment favorable for intensification and Chedza strengthened prior to making landfall in western Madagascar. Satellite imagery indicated an eyelike feature formed and it is possible that Chedza may have reached hurricane intensity before landfall. The terrain of Madagascar is weakening the lower portions of the circulation and that trend should continue while the center is over land. It is possible that Chedza could strengthen after the center moves back over water east of Madagascar.
The tropical cyclone closest to land is Tropical Cyclone Chedza. A cluster of thunderstorms meandering over the Mozambique Channel organized rapidly on Thursday and developed into Tropical Cyclone Chedza. At 9:00 p.m. EST on Thursday the center of Chedza was located at latitude 19.1°S and longitude 42.4°E which put it about 140 miles west-northwest of Belo Tsiribihina, Madagascar. It was moving toward the east at 6 m.p.h. The maximum sustained wind speed was 45 m.p.h. and there were gusts to 55 m.p.h. The minimum surface pressure was 996 mb.
Chedza is over warm Sea Surface Temperatures and the upper level winds are relatively light. Further intensification is likely until Chedza makes landfall on Friday. It is expected to weaken as it crosses Madagascar. Some re-intensification may be possible after the center emerges over the Indian Ocean east of Madagascar. Potential risks include locally heavy rainfall and flooding.
A near equatorial ridge is steering Chedza eastward. It is expected to make landfall in 12 to 18 hours. The ridge is expected to steer Chedza toward the east-southeast as it crosses Madagascar.
At 9:00 p.m. EST on Thursday the center of Tropical Storm Mekkhala was located at 11.6°N and longitude 131.1°E which put it about 540 miles east of Tacloban and about 710 miles east-southeast of Manila, Philippines. Mekkhala was moving toward the west at 9 m.p.h. The maximum sustained wind speed was 45 m.p.h. and there were wind gusts to 60 m.p.h. The minimum surface pressure was 993 mb.
East-southeasterly winds in the upper levels continue to cause moderate wind shear over the top of Mekkhala. It has a well developed low level circulation, but most of the thunderstorm formation is still in the western half of the storm. Although Mekkhala is over warm Sea Surface Temperatures, the wind shear is inhibiting intensification. Further intensification is possible, but it will likely be limited.
A subtropical ridge north of Mekkhala is extending westward and the ridge should continue to steer it westward. The projected path would bring Mekkhala near the central Philippines in 24 to 36 hours. Potential risks include locally heavy rain, flooding and mudslides.
At 9:00 p.m. EST on Thursday the center of Tropical Cyclone Bansi was located at latitude 19.0°S and longitude 64.1°E which put it about 385 miles east-northeast of Port Louis, Mauritius. Bansi was moving toward the east-southeast at 12 m.p.h. The maximum sustained wind speed was 130 m.p.h. and it was estimated there were wind gusts to 160 m.p.h.. The minimum surface pressure was estimated to be 937 mb.
Bansi was in an environment of low vertical wind shear and warm Sea Surface Temperatures for much of Thursday and intensified slightly. The speed of the upper level winds is increasing and the cloud pattern is showing signs of more wind shear. A subtropical high pressure system is likely to move Bansi toward the southeast at a faster speed. Bansi is likely to continue to move toward higher latitudes which will move it over colder water. The speed of the upper level winds will also increase and so Bansi should weaken during the next few days.
Tropical Depression 01W intensified into Tropical Storm Mekkhala on Wednesday. At 11:00 p.m. EST on Wednesday the center of Tropical Storm Mekkhala was located at latitude 11.5°N and longitude 133.8°E which put it about 370 miles north-northwest of Palau and about 820 miles east of Manila, Philippines. Mekkhala was moving toward the west at 16 m.p.h. The maximum sustained wind speed was 40 m.p.h. and there were gusts to 60 m.p.h. The minimum surface pressure was 1000 mb.
Although there are still moderate wind speeds in the upper levels, the wind shear decreased slightly. That allowed more thunderstorms to develop closer to the center of circulation and the system became more organized. A subtropical ridge northeast of Mekkhala will continue to produce southeasterly winds over the top of the circulation. Moderate wind shear will limit intensification. However, Mekkhala will be moving over Warm Sea Surface Temperatures and so some intensification is possible during the next several days.
The subtropical ridge is expected to strengthen and steer Mekkhala westward toward the Philippines. The tropical storm could be approaching the central and northern Philippines in 48 to 72 hours. The main threats appear to be locally heavy rainfall, flooding and mudslides.