Tag Archives: Philippines

Tropical Storm Maysak (04W) Forms East of Chuuk

An area of thunderstorms, that generated mesoscale vortices during the past several days developed a persistent center of circulation on Friday and was classified as Tropical Storm Maysak (04W).  At 11:00 p.m. EDT on Friday the center of Tropical Storm Maysak was located at latitude 7.6°N and longitude 154.9°E which put it about 200 miles east of Chuuk and about 800 miles east-southeast of Guam.  Maysak was moving toward the west at 12 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 989 mb.

Maysak formed over very warm Sea Surface Temperatures, but moderate upper level easterly winds were causing vertical wind shear and kept shearing the top off the circulation.  When the system moved further west, it moved into an area where the upper level winds were not as strong and a center of circulation develop and persisted.  The organization of the circulation has increased during the past 12 hours and Maysak has been intensifying.  It is expected to take a westerly track which would keep it in an area where the upper level winds should not be too strong.  Steady intensification is expected and rapid intensification is possible.  Maysak could become a typhoon in 24 hours and it could become the equivalent of a major hurricane in three or four days.

A subtropical ridge is steering Maysak toward the west and it is expected to keep steering it in that direction during the next few days.  The projected track takes Maysak very near Chuuk during the next 18 to 24 hours.  In a few days it is projected to pass between Guam and Yap and head in the general direction of the northern Philippines.

 

Wind Shear Still Affecting Tropical Storm Bavi

Strong southerly winds in the upper levels are creating vertical wind shear over Tropical Storm Bavi.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Bavi was located at latitude 13.4°N and longitude 140.7°W which put it about 250 miles west of Guam and about 1070 miles east of the Philippines.  Bavi was moving toward the west at 22 m.p.h.  The maximum sustained wind speed was 45 m.p.h. and there were wind gusts to 55 m.p.h.  The minimum surface pressure was 993 mb.

A strong upper level ridge east of Bavi is generating brisk southerly winds over the top of the circulation.  Those winds are causing most of the thunderstorms to occur north of the center of circulation.  The structure of the cyclone also appears to be tilted toward the north.  The poor organization of the circulation is preventing it from intensifying.  If the upper level winds do not decrease, it will be difficult for Bavi to organize further.

A subtropical ridge to the north of Bavi is steering it toward the west.  This general motion is expected to continue for the next few days.  The projected track would bring Bavi or its remnants near the Philippines in a few days.

Tropical Storm Bavi Nearing Guam

Tropical Storm Bavi is moving rapidly toward Guam.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Bavi was located at latitude 13.8°N and longitude 148.7°E which put it about 100 miles east-northeast of Guam.  Bavi was moving toward the west at 18 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 989 mb.

Bavi is moving over water where the Sea Surface Temperatures are around 27.5°C.  So, there is sufficient energy to support intensification.  Moderate easterly winds in the upper levels are generating vertical wind shear over the circulation.  Most of the thunderstorms have been located in the western half of the circulation.  However, recent satellite imagery indicates that there may be more thunderstorms forming near the core of the circulation.  The rapid movement of the storm and the wind shear are likely to limit potential intensification.

A subtropical ridge to the north of Bavi is steering it rapidly to the west and that motion is expected to continue.  Bavi will move  near Guam within a few hours and the core of the circulation could pass near Rota, Tinian and Saipan.  It is likely to bring gusty winds and locally heavy rains as it passes.  The subtropical ridge is expected to steer Bavi or its remnants toward the Philippines during the next few days.

Tropical Storm Bavi Moving Toward Guam

Tropical Storm Bavi continued to move rapidly toward the west-northwest toward Guam on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Bavi was located at latitude 10.7°N and longitude 157.6°E which put it about 880 miles east-southeast of Guam.  Bavi was moving toward the west-northwest at 17 m.p.h.  The maximum sustained wind speed was 45 m.p.h. and there were gusts to 60 m.p.h.  The minimum surface pressure was 989 mb.

Strong easterly winds in the upper levels are creating vertical wind shear and are inhibiting intensification of Bavi.  The wind shear is also causing most of the thunderstorms to be located on the western side of the circulation.  Thus, Bavi is not well organized at the current time.  However, Bavi is moving over warm Sea Surface Temperatures and it could strengthen slowly as it moves farther west, if the wind shear decreases.

A strong subtropical ridge to the north of Bavi is steering it rapidly westward.  Bavi could be in the vicinity of Guam in about 48 hours.  The ridge is expected to continue to steer Bavi westward after it moves past Guam and it could approach the Philippines in a few days.

Tropical Depression 01W Forms East of Yap

The first tropical depression of 2015 over the Western North Pacific Ocean formed east of Yap on Tuesday.  At 7:00 p.m. EST on Tuesday the center of Tropical Depression 01W (TD01W) was located at latitude 10.1°N and longitude 139.9°E which put it about 130 miles east-northeast of Yap and about 1250 miles east-southeast of Manila, Philippines.  TD01W was moving toward the northwest at 13 m.p.h.  The maximum sustained wind speed was 35 m.p.h. and there were gusts to 45 m.p.h.  The minimum surface pressure was estimated to be 1000 mb.

A subtropical ridge is generating southeasterly winds over the top of TD01W and producing moderate wind shear.  The wind shear is causing much of the thunderstorm activity to be located in the northwestern part of the circulation around TD01W.  The lack of thunderstorms in the southern portion of the circulation is limiting the intensification of the tropical depression.  TD01W is over Sea Surface Temperatures that are around 30°C and so the potential for intensification exists if the speed of the upper level winds diminish.

The subtropical ridge is expected to continue to steer the tropical depression in a general west or west-northwesterly direction during the next few days.  This projected path could bring the tropical cyclone near the Philippines later this week.

 

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.