Tag Archives: Philippines

Remnants of Jangmi Approaching Northern Borneo

Wind shear continues to prevent reintensification of former Tropical Storm Jangmi and the circulation consists primarily of shallow convection.  The system still possesses a well developed cyclonic circulation in the lower atmosphere that is clearly apparent on visible satellite imagery.  At 11:00 p.m. EST on Wednesday the center of the remnants of Jangmi were located at latitude 6.8°N and longitude 118.8°E which put it about 175 miles west-northwest of Jolo in the Philippines, about 140 miles east of Kudat, Malaysia and about 150 miles northeast of Sandakan, Malaysia.  The center was moving toward the west-southwest at 6 m.p.h.  The maximum sustained wind speed was 30 m.p.h. and there were gusts to 40 m.p.h.  The minimum surface pressure was 1007 mb.

A subtropical ridge to the north of Jangmi continues to generate southeasterly winds with speeds near 35 m.p.h. in the upper levels over the system.  The strong upper level winds are shearing the tops of thunderstorms which start to develop near the center and are preventing the redevelopment of Jangmi.  The center of circulation is over warm Sea Surface Temperatures and so convection continues to develop but the strong wind shear keeps it shallow.

Since circulation is comprised almost entirely of shallow convection it is being steered by the winds in the lower level of the atmosphere.  Those winds are likely to continue to carry the circulation in a generally west-southwesterly direction, which would bring it near the northern coast of Borneo in 18 to 24 hours.  It could produce locally heavy rainfall and some flooding may be possible where it makes landfall.

 

Jangmi Weakens over Sulu Sea

Increased vertical wind shear blew the tops off of thunderstorms and Tropical Storm Jangmi weakened to a tropical depression,  At 11:00 p.m. EST on Tuesday the center of Tropical Depression Jangmi was located at latitude 8.0°N and longitude 120.8°E which put it about 150 miles north of Jolo, Philippines and about 300 miles east-northeast of Kudat, Malaysia on the northern end of Borneo.  Jangmi was moving toward the west-southwest at 7 m.p.h.  The maximum sustained wind speed was 30 m.p.h. and there were gusts to 40 m.p.h.

A subtropical ridge north of Jangmi intensified southeasterly winds in the upper levels and increased the wind shear over the top of the tropical storm.  The stronger upper level winds blew away the upper portions of thunderstorms and the circulation contained mainly shallower convection during the most recent 12 hours.  Recent satellite images show the redevelopment of some thunderstorms southwest of the center of circulation, but some wind shear continues.  Jangmi is over Sea Surface Temperatures that are warm enough to support some intensification, but that will not happen if the wind shear continues.  If Jangmi continues to move southwestward, interaction with the island of Borneo could weaken the circulation and possibly cause it to dissipate entirely.  If the center passes just west of Borneo, then some intensification may be possible, unless the wind shear remains too strong.

Since the circulation of Jangmi consisted mainly of shallower convection, it was steered toward the southwest by northeasterly winds in the lower levels of the atmosphere.  Even though a few thunderstorms have redeveloped, most of the convection is still shallow and Jangmi is likely to continue to be steered in a generally west-southwesterly direction.  The projected track could bring Jangmi or its remnants near the northern end of Borneo in 24-48 hours.

 

 

Tropical Storm Jangmi Moving across the Sulu Sea

Tropical Storm Jangmi moved across Mindanao and the center passed near Cebu.  It has now moved back over the open waters of the Sulu Sea.  At 11:00 p.m. EST on Monday the center of Tropical Storm Jangmi was located at latitude 10.4°N and longitude 121.0°E which put it about 320 miles south of Manila, about 200 miles east-northeast of Puerto Princesa and about 1300 miles east-northeast of Singapore.  Jangmi was moving toward the west at 11 m.p.h.  The maximum sustained wind speed was 45 m.p.h. and there were gusts to 60 m.p.h.

Thunderstorms are beginning to redevelop near the center of circulation now that it has moved back over water.  The low level center appears to be relatively intact after its passage over some of the islands in the southern Philippines.  Easterly winds in the upper levels are generating some wind shear, but there is well developed upper level outflow on the northern side of Jangmi.  It will be moving over warm Sea Surface Temperatures and some intensification is possible as it moves westward.

Jangmi is being steered to the west by a subtropical ridge located to its north.  The general westward motion is expected to continue in the short term.  Eventually, northeasterly winds are expected to push Jangmi in a more west-southwesterly direction over the next few days.  The projected track is expected to take the center across Palawan near Puerto Princesa in about 24 hours.  The west-southwesterly motion is expected to continue and it could take Jangmi in the general direction of Malaysia.

Jangmi could bring some locally heavy rainfall to parts of Palawan and some flooding and landslides are possible.

 

Tropical Storm Hagupit Maintaining Its Intensity for Now

Tropical Storm Hagupit maintained its intensity on Tuesday as it moved farther away from the Philippines.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Hagupit was located at latitude 13.3°N and longitude 116.6°E which put it about 320 miles west-southwest of Manila, Philippines and about 475 miles east-northeast of Cam Ranh, Vietnam.  Hagupit was moving toward the west at 13 m.p.h.  The maximum sustained wind speed was 50 m.p.h. and there gusts to 65 m.p.h.

Thunderstorms continue to develop near the center of circulation and upper level outflow is evident on satellite images.  However, Hagupit is likely to move into a more unfavorable environment as it moves westward.  Northeasterly winds over the lower levels of the South China Sea contain cooler and drier air.  Some of the cooler, drier air may be getting pulled around the western and southern portions of Hagupit’s circulation.  If the drier air reaches the center of circulation, then deep convection will diminish and the wind speeds will decrease.  Hagupit is also likely to move into an area of more vertical wind shear as it moves westward, which could weaken the storm even faster.

Hagupit is currently being steered westward by a subtropical ridge located north of it.  If Hagupit weakens and the convection becomes shallower, if could be steered toward the southwest or west-southwest by the northeasterly winds in the lower levels.  The center of Hagupit could near the coast of Vietnam in about 36 hours.

 

Tropical Storm Hagupit Moving Away From the Philippines

Tropical Storm Hagupit has moved across the central Philippines and it is now beginning to move into the South China Sea.  At 10:00 p.m. EST on Monday the center of Tropical Storm Hagupit was located at latitude 13.5°N and longitude 119.9°E which put it about 100 miles southwest of Manila.  Hagupit was moving toward the southwest at 11 m.p.h.  The maximum sustained wind speed was 45 m.p.h. and there were gusts to 60 m.p.h.

Some thunderstorms have redeveloped near the center of Hagupit now that it is back out over open water.  It is possible that the tropical storm could maintain its intensity or even strengthen a little in the short term.  However, as Hagupit moves farther west it will encounter a northeasterly flow of cooler and drier air and more pronounced vertical wind shear.  The more unfavorable thermodynamic environment and wind shear will likely cause Hagupit to weaken during the next few days.

The northeasterly winds are expected to push a weakening tropical storm or depression in the general direction of southern Vietnam.  Hagupit or its remnants could make landfall in Vietnam in about 72 hours.

 

Hagupit Weakening As It Moves Across the Philippines

Hagupit has weakened below typhoon intensity and it is now a tropical storm.  At 10:00 p.m. EST on Sunday the center of Tropical Storm Hagupit was located at latitude 13.4°N and longitude 112.7°E which put it near Catanauan, Philippines and about 140 miles southeast of Manila.  Hagupit was moving toward the northwest at 7 m.p.h.  The maximum sustained wind speed was 70 m.p.h. and there were gusts to 85 m.p.h.

Interaction of the circulation with land and moderate vertical wind shear have gradually reduced the intensity of Hagupit and the weakening trend should continue on Monday.  Once Hagupit moves west of the Philippines, it will move into an area of stronger northeasterly winds in the lower levels and cooler, drier air.  As a result the rate of weakening could increase.

There are indications that Hagupit could begin to move toward the southwest when it encounters the stronger northeasterly flow.  A much weaker Hagupit or its remnants could reach southern Vietnam in a few days.

 

Hagupit Intensifies Rapidly Into a Super Typhoon

Typhoon Hagupit continued to intensify rapidly on Wednesday and it is now the equivalent of a Category 5 hurricane.  At 7:00 p.m. EST on Wednesday the center of Super Typhoon Hagupit was located at latitude 9.8°N and longitude 133.9°E which put it about 175 miles north of Palau, about 600 miles east of Tacloban, Philippines and about 930 miles east-southeast of Manila.  Hagupit was moving toward the west-northwest at 17 m.p.h.  The maximum sustained wind speed was 175 m.p.h. and there were estimated gusts to 215 m.p.h.

Hagupit is in a very favorable environment.  It is over warm Sea Surface Temperatures and the upper level winds are light.  Upper level outflow is well developed and it is pumping out mass in all directions.  The environment is capable of supporting a little further intensification.  However, when tropical cyclones become as intense as Hagupit, they often undergo eyewall replacement cycles, which can produce fluctuations in intensity.  Hagupit is expected to remain an intense typhoon during the next two to three days.

A subtropical ridge north of Hagupit is steering the typhoon toward the west-northwest.  The ridge is expected to steer Hagupit in the same general direction during the next 48 hours.  After that time an upper level trough in the westerly flow near Japan is expected to weaken the subtropical ridge and the forward motion of Hagupit could slow down.  There is much more uncertainty about the track forecast beyond three days.  One set of forecast models is predicting that Hagupit will turn toward the north before it reaches the Philippines.  However, another set of forecast models keeps Hagupit moving westward and reaching the Philippines during the weekend.  Given the intensity of Hagupit, it could be a destructive typhoon if it does move through the Philippines.

 

Typhoon Hagupit Intensies Rapidly As It Nears Yap

Typhoon Hagupit intensified rapidly on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Typhoon Hagupit was located at latitude 7.9°N and longitude 139.5°E which put it about 190 miles southeast of Yap and about 1330 miles east-southeast of Manila, Philippines.  Hagupit was moving toward the west-northwest at 21 m.p.h.  The maximum sustained wind speed had increased to 105 m.p.h. and there were gusts to 130 m.p.h.

Hagupit is in an environment favorable for further intensification.  It is moving over warm Sea Surface Temperatures (SSTs) and the upper level winds remain light.  The upper level outflow is well developed and it continues to pump out mass and allow the surface pressure to decrease.  Hagupit is likely to continue to intensify on Wednesday and it could reach Super Typhoon intensity in several days.

Hagupit is being steered toward the west-northwest by a subtropical ridge located to its north.  On this track the center of Hagupit will pass just south of Yap in a few hours.  An upper level trough in the westerly flow near Japan will weaken the subtropical ridge and Hagupit is likely to move more slowly in two or three days.  The winds at the steering level will be weak in three or four days and the longer term track of Hagupit is more uncertain.  There is a possibility that it could be steered westward toward the Philippines.

Tropical Storm Hagupit Organizing Rapidly South of Guam

Tropical Depression 22W organized rapidly on Monday and intensified into Tropical Storm Hagupit.  At 10:00 p.m. EST on Monday the center of Tropical Storm Hagupit was located at latitude 6.1°N and longitude 146.0°E which put it about 490 miles south-southeast of Guam and about 570 miles east-southeast of Yap.  Hagupit was moving toward the west at 24 m.p.h.  The maximum sustained wind speed was 65 m.p.h. and there were gusts to 80 m.p.h.

Hagupit has developed multiple spiral bands of thunderstorms and there are some indications that an eye may be forming at the center of the circulation.  There is a large and well developed circulation around the tropical storm.  The winds in the upper levels are relatively light and upper level divergence continues to pump out mass from the center of circulation.  Hagupit will continue to move over warm Sea Surface Temperatures and the environment is favorable for continued intensification.  Hagupit could become a typhoon on Tuesday and it could be a strong typhoon in several days.

A subtropical ridge north of Hagupit is steering the storm toward the west and it is likely to steer the tropical storm in a general west-northwesterly direction during the next 48-72 hours.  The projected path would bring Hagupit very close to Yap in about 36 hours.   There is more uncertainty about the possible track of Hagupit after it passes Yap because an upper level trough moving north of the storm could weaken the subtropical ridge.  If the ridge weakens, the winds at the steering level could become weaken and the motion of Hagupit could slow.

 

Tropical Depression 21W Bringing Rain to Central Philippines

Tropical Depression 21W (TD 21W) is bringing rain to parts of the Central Philippines as it moves toward the west-northwest.  At 7:00 p.m. EST on Wednesday the center of TD 21W was located at latitude 9.8°N and longitude 122.9°E which put it about 70 miles east of Cebu and about 350 miles south-southeast of Manila.  TD21W was moving toward the west-northwest at 20 m.p.h.  The maximum sustained wind speed was 35 m.p.h. and there were gusts to 45 m.p.h.

TD 21W appears to be developing some spiral bands of showers and thunderstorms and it could become more organized as it moves away from the Philippines.  It is over warm Sea Surface Temperatures and upper level outflow appears to be developing.  As a result of those factors TD 21W could intensify into a tropical storm during the next 24-36 hours.  Available guidance suggest that TD 21W will continue to move in a general west-northwesterly direction and it could approach the coast of Vietnam in about three days.