Tag Archives: the Philippines

Tropical Storm Megi Forms West of the Marianas

Tropical Storm Megi formed west of the Marianas on Friday.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Megi was located at latitude 16.4°N and longitude 137.1°E which put it about 1160 miles (1870 km) east-southeast of Taipei, Taiwan.  Megi was moving toward the west at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 45 m.p.h. (70 km/h) and there were wind gusts to 60 m.p.h. (95 km/).  The minimum surface pressure was 996 mb.

The circulation of Tropical Storm Megi is still organizing.  A distinct center of circulation is still consolidating.  There are more thunderstorms south and east of the center of circulation, but bands of thunderstorms are beginning to develop in other quadrants of the storm.  The thunderstorms closer to the center are generating upper level divergence which is pumping out mass.  Outflow channels could be developing to the northwest and southeast of Tropical Storm Megi.

Tropical Storm Megi is moving into an environment that is favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are not very strong and there is little vertical wind shear.  Tropical Storm Megi is likely to continue to intensify while the circulation becomes better organized.  Once a well formed core develops at the center of Megi, it could intensify more rapidly.  Tropical Storm Megi is likely to become a typhoon during the weekend.

Tropical Storm Megi is moving along the southwestern side of a subtropical ridge, which is steering it toward the west.  A westerly or west-northwesterly motion is expected to continue for the next few days.  On its anticipated track Tropical Storm Megi could approach Taiwan in about three days.  Megi is likely to be a typhoon at that time.

Typhoon Malakas Moves Toward Taiwan and the Ryukyu Islands

Typhoon Malakas moved toward Taiwan and the southernmost Ryukyu Islands on Thursday.  At 8:00 p.m. EDT on Thursday the center of Typhoon Malakas was located at latitude 20.1°N and longitude 124.7°W which put it about 285 miles (460 km) south of Ishigaki, Japan.  Malakas was moving toward the northwest at 15 m.p.h. (24 km/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 956 mb.

The structure of Typhoon Malakas is well organized.  A small eye has been evident intermittently on satellite imagery.  More of the thunderstorms are forming south of the center of circulation, although there are spiral bands of thunderstorms in all quadrants of the circulation.  The thunderstorms in the core of Typhoon Malakas are generating upper level divergence which is pumping out mass in all directions.  The circulation of Typhoon Malakas has been in a rough equilibrium during the past 24 hours and the intensity has remained relatively steady.

Typhoon Malakas is moving through an environment that is favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  Although there is an upper level trough over China and an upper level low to the northeast of Malakas, the upper level winds around the typhoon are relatively light.  There is not much vertical wind shear.  Typhoon Malakas could strengthen further during the next 24 hours.

Typhoon Malakas is moving around the western end of a subtropical ridge.  Malakas turned more toward the northwest on Thursday.  It is expected to move more toward the north on Friday as is reaches the western end of the ridge.  When Malakas moves farther north, the upper level trough over China will steer the typhoon quickly toward the northeast toward the southern end of Kyushu.  On its anticipated track Typhoon Malakas will be near northeastern Taiwan and the southernmost Ryukyu Islands in about 24 hours.

Typhoon Malakas is smaller than Typhoon Meranti was, but Typhoon Malakas is capable of causing significant wind damage.  It will also bring heavy rain.  Since areas on Taiwan received heavy rain when Typhoon Meranti moved past them, it will take less additional rain to create the potential for flash flooding.

Strong Typhoon Meranti Nears Landfall in China

Strong Typhoon Meranti is near a landfall on the east coast of China close to Xiamen.  At 11:00 a.m. EDT on Wednesday the center of Typhoon Meranti was located at latitude 23.9°N and longitude 118.4°E which put it about 40 miles (65 km) south-southeast of Xiamen, China.  Meranti was moving toward the northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 145 m.p.h. (235 km/h) and there were wind gusts to 175 m.p.h. (280 km/h).  The minimum surface pressure was 931 mb.

Meranti has weakened during the past 24 hours, but it remains a strong typhoon.  The Hurricane Intensity Index (HII) for Typhoon Meranti is 29.9.  The Hurricane Size Index (HSI) is 24.5 and the Hurricane Wind Intensity Size Index is 54.4.  These indices suggest that Typhoon Meranti is capable of causing widespread significant damage when it makes landfall.  As a comparison, the HII for Hurricane Ivan just before it made landfall on the Gulf Coast in 2004 was 22.1, the HSI was 34.1 and the HWISI was 56.2.  Thus, Typhoon Meranti is stronger than Hurricane Ivan was, but Meranti is also smaller than Ivan was in 2004.  The HWISI for Typhoon Meranti is close to what it was for Hurricane Ivan.

The center and inner eyewall of Typhoon Meranti moved just south of the southern end of Taiwan.  Since the eyewall stayed over water, it remained intact.  However, the outer concentric eyewall and much of the northern half of the circulation did move across Taiwan.  Flow over the mountains on Taiwan did weaken the northern half of the circulation, while the center and southern half of the circulation remained intact.  Since the core of the circulation stayed over the water, Typhoon Meranti stayed stronger than it would have if the inner eye had moved over Taiwan.

Most of the stronger thunderstorms and heavier rain are near the center of circulation and south of the center.  There are rainbands in other parts of Typhoon Meranti and some of those rainbands are already bringing heavy rain to parts of eastern China.

Typhoon Meranti is moving around the western end of a subtropical ridge which is steering it toward the northwest.  Meranti is expected to turn more toward the north as it move inland over China.  On its anticipated track Typhoon Meranti is expected to move northwest over Fujian province and then turn north toward Nanchang.

Typhoon Meranti is capable of causing significant wind damage over eastern China.  In addtion strong winds will create a significant storm surge along the coast near Xiamen.  Heavy rain will spread inland over Fujian province and the rain could create the potential for flooding over parts of eastern China.

Extremely Powerful Typhoon Meranti Nearing Southern Taiwan

The center of extremely powerful Typhoon Meranti moved closer to the southern end of Taiwan during the past few hours.  At 5:00 p.m. EDT on Tuesday the center of Typhoon Meranti was located at latitude 21.1°N and longitude 121.3°E which put it about 65 miles (105 km) south-southeast of Hengchun, Taiwan.  Meranti was moving toward the west-northwest at 11 m.p.h. (18 km/h).  The maximum sustained wind speed was 190 m.p.h. (305 km/h) and there were wind gusts to 230 m.p.h. (370 km/h).  The minimum surface pressure was 887 mb.

Typhoon Meranti is large and powerful.  The Hurricane Intensity Index (HII) is 46.1.  The Hurricane Size Index (HSI) is 27.9 and the Hurricane Wind Intensity Size Index (HWISI) is 74.0.  As a source of comparison, when Hurriane Katrina was at its peak intensity as a Category 5 hurricane over the Gulf of Mexico in 2005, its HII was 38.6, its HSI was 33.7, and its HWISI was 72.3.  Typhoon Meranti is stronger than Hurricane Katrina was, but Meranti is a little smaller than Katrina was in 2005.  The indices suggest that Typhoon Meranti is capable of causing widespread catastrophic damage.

The circulation of Typhoon Meranti is symmetrical and very well organized.  It possess a tight core consisting of a small inner eye surrounded by a ring of very tall thunderstorms.  A second, larger outer eyewall completely surrounds the inner eye.  The strongest winds are occurring in the inner eyewall near the center of circulation.  Winds to typhoon force are also occurring in the outer eyewall and extend out at least 80 miles (130 km) from the center of circulation.  Additional bands of strong thunderstorms are rotating around the outer eyewall.  Typhoon Meranti is generating strong upper level divergence which is pumping out large quantities of mass and is allowing the surface pressure to be so low.

Typhoon Meranti is probably at its peak intensity.  It is still moving over water where the Sea Surface Temperature is near 31°C.  However, the northwestern edge of the outer eyewall appears to be moving over the southern end of Taiwan.  As more of the circulation moves over Taiwan, there will be some disruption of the airflow.  The center of Typhoon Meranti could move very close to the southern tip of Taiwan.  If the center of Meranti moves over southern Taiwan, then the typhoon will weaken more quickly.  It currently appears that the center of Typhoon Meranti could move just south of the southern tip of Taiwan, and on that track the typhoon would not weaken as quickly.  When Typhoon Meranti moves west of Taiwan, it will move over slightly cooler SSTs before it reaches China.  Meranti will weaken more before it reaches China, but it will still be a significant typhoon when it makes landfall there.

The center of Typhoon Meranti is wobbling a little as the inner eye rotates around inside the outer eyewall.  If one averages the wobbles, then then core of Meranti is moving on a general west-northwesterly track.  On its anticipated track, the center of Typhoon Meranti will pass very near the southern end of Taiwan during the next few hours.  It could turn slightly toward the northwest as it moves west of Taiwan.  Typhoon Meranti could make a landfall on the coast of China between Xiamen and Shantou in about 24 hours.

Typhoon Meranti is an extremely dangerous storm.  It is capable of causing widespread catastrophic wind damage.  In addition, its intensity and size will produce very heavy rainfall, especially on the eastern slopes of the mountains on Taiwan.  Flash flooding is likely.  Typhoon Meranti will also produce heavy rain over eastern China and additional flooding is likely in that region.  Typhoon Meranti will also cause a significant storm surge in low lying coastal areas.

Typhoon Meranti Becomes Equivalent of Cat. 5 Hurricane and Threatens Taiwan

Typhoon Meranti rapidly intensified into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale as it moved on a course that threatens Taiwan.  At 11:00 a.m. EDT on Monday the center of Typhoon Meranti was located at latitude 19.2°N and longitude 127.6°E which put it about 495 miles (800 km) southeast of Taiwan.  Meranti was moving toward the west-northwest at 14 m.p.h. (23 km/h).  The maximum sustained wind speed was 180 m.p.h. (290 km/h) and there were wind gusts to 220 m.p.h. (355 km/h).  The minimum surface pressure.

Meranti is a large dangerous typhoon.  The Hurricane Intensity Index (HII) is 42.2.  The Hurricane Size Index (HSI) is 25.5 and the Hurricane Wind Intensity Size Index (HWISI) is 67.7.  Those indices suggest that Typhoon Meranti is capable of causing widespread catastrophic damage.

The structure of Typhoon Meranti is very well organized.  A well formed circular eye is surrounded by a ring of very tall thunderstorms.  Additional strong spiral bands of thunderstorms are rotating around the core of the circulation.  Typhoon Meranti is generating strong upper level divergence which is pumping out mass in all directions.

Typhoon Meranti is moving through an environment that will allow it to maintain much of its intensity until it reaches Taiwan.  It is moving over water where the Sea Surface Temperature is near 31°C.  The upper level winds are weak and there is not much vertical wind shear.  If a rainband wraps around the existing eye, then an eyewall replacement cycle could temporarily weaken Typhoon Meranti.

A subtropical ridge is steering Typhoon Meranti toward the west-northwest and that general motion is expected to continue for several more days.  On its anticipated track Typhoon Meranti will be very near the southern tip of Taiwan in about 36 hours.  After it moves past Taiwan it is forecast to move into eastern China.

Meranti is an extremely dangerous typhoon.  It is capable of causing widespread catastrophic wind damage.  In addition it will produce very heavy rain and flooding is a serious concern.

Typhoon Meranti Strengthens Quickly Into the Equivalent of a Major Hurricane

Typhoon Meranti intensified rapidly on Sunday into the equivalent of a major hurricane.  At 11:00 p.m. EDT on Sunday the center of Typhoon Meranti was located at latitude 18.1°N and longitude 129.7°E which put it about 650 miles (1050 km) east-southeast of Taiwan.  Meranti was moving toward the west-northwest at 17 m.p.h. (27 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 948 mb.

Typhoon Meranti intensified very rapidly on Sunday.  A small, well formed eye developed at the center of Meranti.  A ring of strong thunderstorms surrounds the eye and additional bands of thunderstorms are spiraling around the core of the circulation.  The circulation is very symmetrical.  Thunderstorms in the core of Typhoon Meranti are generating strong upper level divergence which is pumping out large amounts of mass in all directions.  Meranti is a very well organized typhoon.

Typhoon Meranti is moving through a very favorable environment. It is moving over water where the Sea Surface Temperature is near 31°C.  The upper level winds are weak and there is little vertical wind shear.  Meranti will continue to intensify and it could become a Super Typhoon.  If an eyewall replacement cycle occurs, there could be fluctuations in the intensity of Meranti.

A subtropical ridge is steering Typhoon Meranti toward the west-northwest and that general motion is expected to continue for another couple of days.  On its anticipated track Typhoon Meranti will be near northern Luzon, Taiwan and the southern Ryukyu Islands in about 48 hours.  Meranti will be a dangerous typhoon at that time.  It will be capable of significant wind damage.  It will also cause very heavy rain and create the potential for significant flooding.

Tropical Storm Meranti Forms West of Guam

A center of circulation developed within an area of thunderstorms west of Guam on Saturday and the system was designated as Tropical Storm Meranti.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Meranti was located at latitude 16.0°N and longitude 135.8°E which put it about 1070 miles (1725 km) east-southeast of Taiwan.  Meranti was moving toward the west at 13 m.p.h. (20 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 991 mb.

The circulation of Tropical Storm Meranti is still organizing and the distribution of thunderstorms is asymmetrical.  Most of the thunderstorms are occurring east of the center of circulation.  There is a cluster of the thunderstorms just to the east of the center.  There are also two well formed rainbands east of the core of Tropical Storm Meranti.  Additional spiral bands are located in all parts of the tropical storm.  The thunderstorms near the center are generating upper level divergence which is pumping out mass in all directions.

Tropical Storm Meranti is moving through an environment which is favorable for further intensification.  It is moving over water where the Sea Surface Temperature is near 31°C.  An upper level ridge located to the northwest of Meranti is producing northeasterly winds which are blowing across the western portion of the tropical storm.  The upper level winds are weaker over the eastern half of the circulation and the vertical wind shear is only slowing the intensification.  Although there may be some drier air in the western half of the circulation, Tropical Storm Meranti could intensify into a typhoon on Sunday.  Meranti could become a strong typhoon in two or three days.

A subtropical ridge north of Tropical Storm Meranti is steering it toward the west.  The subtropical ridge is forecast to steer Meranti in a general west-northwesterly direction during the next two or three days.  On its anticipated track Tropical Storm Meranti is expected to approach the area of northern Luzon, Taiwan and the southern Ryukyu Islands in about three days.  It could be a strong typhoon at that time.

Typhoon Nida Brushes Luzon and Heads for Hong Kong

Typhoon Nida brought wind and rain to northern Luzon on Sunday as it continued to move toward Hong Kong on the coast of China.  At 11:00 p.m. EDT on Sunday the center of Typhoon Nida was located at latitude 20.4°N and longitude 118.3°E which put it about 340 miles (545 km) east-southeast of Hong Kong.  Nida was moving toward the west-northwest at 17 m.p.h. (27 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 974 mb.

The Hurricane Intensity Index (HII) for Typhoon Nida is 10.4.  The Hurricane Size Index (HSI) is 13.1 and the Hurricane Wind Intensity Size Index (HWISI) is 23.5.  These indices suggest that Typhoon Nida will be capable of causing minor wind damage on a regional scale.

The structure of Typhoon Nida changed significantly on Sunday.  The primary rainband wrapped around the core of the circulation and a very large eye was created at the center.  The diameter of the eye is approximately 50 miles (80 km).  The strongest winds are occurring in the ring of thunderstorms that surrounds the eye.  Other spiral bands of thunderstorms are rotating around the large eye.  The thunderstorms were generating upper level divergence which pumped out mass and allowed the surface pressure to decrease.

Typhoon Nida is in an environment that would favor intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  Easterly winds are blowing in the upper levels, but there is not much vertical wind shear.  The large size of the eye of Nida is the major factor inhibiting intensification.  It takes more energy to increase the wind speed in a large typhoon than it does in a smaller storm.  If the eye contracts, then Typhoon Nida could intensify more before it makes landfall.

A subtropical ridge north of Nida is steering the typhoon toward the west-northwest and that general motion is expected to continue for another day or so.  On its anticipated track Typhoon Nida will be very near Hong Kong in about 24 hours.

As mentioned above, the large size of Typhoon Nida means that it will be capable of causing wind damage on a regional scale.  In addition, Typhoon Nida will be capable of creating a significant storm surge when it moves into the coast of China.  A large slow moving typhoon like Nida will also produce heavy rain and flooding as it moves inland.

Typhoon Noul Equivalent of Category 5 Hurricane

Typhoon Noul moved into an area with very little vertical wind shear and intensified into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Saturday.  At 11:00 p.m. EDT on Saturday Typhoon Noul was located at latitude 17.4°N and longitude 123.1°E which put it about 130 miles east of Tuguegarao and about 85 miles southeast of Escarpada Point on the northeastern tip of Luzon.  Noul was moving toward the north-northwest at 12 m.p.h.  The maximum sustained wind speed was 160 m.p.h. and there were gusts to 195 m.p.h.  The minimum surface pressure was 918 mb.

Noul is at the western end of the subtropical ridge that has been steering it toward the northwest.  It should gradually turn more toward the north on Sunday.  The anticipated track will take the center of Noul very close to the northeastern tip of Luzon in a few hours.  As it moves northward, it will start to be affected by westerly winds in a day or so.  Those winds will turn it more toward the northeast and it could affect some of the southern islands of Japan early next week.

As Noul moves toward the north it will move over cooler Sea Surface Temperatures  (SSTs).  In addition the upper level westerly winds will create more vertical wind shear over Noul.  The combination of cooler SSTs and more vertical wind shear will cause Noul to weaken throughout the next few days.  However, if could still be a typhoon when it passes by Okinawa in about 48 hours.

Noul could bring strong winds and heavy rain to the northeastern tip of Luzon on Sunday.  Mudslides could be a possibility in locations that receive heavy rain.

 

Typhoon Noul Approaching the Philippines

Typhoon Noul continued to move steadily toward the west-northwest on Friday and it is approaching the northeastern Philippines.  At 3:00 pm. EDT on Friday the center of Typhoon Noul was located near latitude 13.9°N and longitude 127.0°E which put it about 300 miles east of Labo and about 480 miles east-southeast of Tuguegarao in the Philippines.  Noul was moving toward the west-northwest at 14 m.p.h.  The maximum sustained wind speed was 120 m.p.h. and there were gusts to 150 m.p.h.  The minimum surface pressure was 944 mb.  Noul is the equivalent of a Category 3 hurricane on the Saffir-Simpson Scale.

Noul is being steered to the west-northwest by a subtropical ridge located northeast of it.  As Noul nears the western end of the ridge, it is expected to begin to move more toward the northwest.  As Noul approaches the northeastern coast of Luzon, an upper level trough to the west is expected to turn it more toward the north.  The timing of the turn is still uncertain which makes the track forecast more difficult.  On its projected track Noul would approach northeastern Luzon in about 30 hours.

Noul is over Sea Surface Temperatures near 29°C and there is not much vertical wind shear.  However, there are fewer thunderstorms in the northwestern portion of the circulation and the could be some drier air in that region.  The environment is favorable for intensification but large changes in Noul’s intensity are not expected.  Noul is expected to be a significant typhoon when it approaches Luzon and it could bring strong winds and locally heavy rain to that region.  The heavy rain could lead to mudslides in areas where the slopes are steeper.