Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

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.

Typhoon Noul Intensfying North of Palau

Typhoon Noul continued to intensify on Wednesday as it passed north of Palau.  At 10:00 p.m. EDT on Wednesday the center of Typhoon Noul was located at latitude 10.7°N and longitude 133.7°E which put it about 270 miles north of Palau and about 550 miles east of the Philippines.  Noul was moving toward the west-northwest at 14 m.p.h.  The maximum sustained wind speed was 105 m.p.h. and there were gusts to 125 m.p.h.  The minimum surface pressure was 955 mb.

Noul is moving over water where the Sea Surface Temperatures are near 29°C.  It is moving close to the axis of an upper level ridge and so the vertical wind shear is low.  The environment is favorable for further intensification and Noul could eventually reach the equivalent of a major hurricane.

A subtropical ridge north of Noul is steering it toward the west-northwest and that motion is expected to continue for several days.   On its projected track Noul could approach the Philippines in two days and it could be near Luzon in three days.  As Noul nears Luzon it is expected to turn more toward the north.  If the circulation is intact after it crosses Luzon, it could head toward Taiwan.

Tropical Depression 07W Forms South of Pohnpei

The active period over the tropical Western North Pacific Ocean continues with the development of another tropical cyclone south of Pohnpei.  At 8:00 p.m. EDT on Wednesday the center of Tropical Depression 07W was located at latitude 4.4°N and longitude 156.8°E which put it about 160 miles south-southeast of Pohnpei.  The tropical depression was stationary.  The maximum sustained wind speed was 35 m.p.h. and there were gusts to 50 m.p.h.  The minimum surface pressure was 1004 mb.

A low level circulation center formed within a broad area of thunderstorms and the system was classified as Tropical Depression 07W.  The strongest thunderstorms are mainly located in the northwestern part of the circulation.  An upper level ridge located east of the depression is generating southeasterly winds over the top of it which is producing modest vertical wind shear.  The wind shear is the probably reason why most of the thunderstorms are northwest of the center of circulation.  The wind shear will also limit the rate of intensification during the next day or two.  Eventually the depression is expected to move farther west into an area with less wind shear and it could intensify more quickly.

Tropical Depression 07W is located near the western end of a subtropical ridge and the steering currents are relatively weak.  It may not move much for the next 12 to 24 hours.  Later this week the ridge is expected to strengthen and steer the depression toward the west-northwest.  On its projected track the depression could approach Pohnpei in two or three days.

Noul Intensified Into a Typhoon As It Passed Over Yap

Tropical Storm Noul intensified slowly on Tuesday and it attained typhoon status as it passed over Yap.  At 10:00 p.m. EDT on Tuesday the center of Typhoon Noul was located at latitude 9.5°N and longitude 137.5°E which put it about 20 miles west-southwest of Yap and about 230 miles east-northeast of Palau.  Noul was moving toward the west at 5 m.p.h.  The maximum sustained wind speed was 75 m.p.h. and there were gusts to 90 m.p.h.  The minimum surface pressure was 976 mb.  Noul brought wind and heavy rain to Yap on Tuesday.  The International Airport reported a wind gust of 68 m.p.h. as the center of Noul passed just south of it.

An upper level ridge located east of the center of circulation is causing light easterly winds to blow over the top of Noul, which is generating some vertical wind shear.  The shear could be the reason why most of the strongest thunderstorms are occurring in the southwestern quadrant of the circulation.  Noul remains over water where the Sea Surface Temperature is around 29°C.  The vertical wind shear is likely to slow the rate of intensification, but Noul is in an environment that favors further strengthening.

Noul is at the western end of a subtropical ridge and the steering pattern is relatively weak.  It is likely to continue to move slowly for another 12 to 24 hours.  Eventually a subtropical ridge is expected to build north of Noul and steering it toward the west-northwest at a faster speed.  On its projected path the center of Noul would pass several hundred miles north of Palau.  Noul could be approaching the northern Philippines by late in the week.

 

Tropical Storm Noul Nearing Yap and Intensifying

Tropical Storm Noul intensified on Monday as it moved closer to Yap.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Noul was located at latitude 9.4°N and longitude 138.8°E which put it about 55 miles east of Yap and about 290 miles east-northeast of Palau.  Noul was moving toward the west-southwest at 5 m.p.h.  The maximum sustained wind speed was 65 m.p.h. and there were gusts 80 m.p.h.  The minimum surface pressure was 982 mb.

A primary rainband appears to be wrapping around the small center of circulation in Tropical Storm Noul.  It continues to move over water where the Sea Surface Temperature in near 29°C.  A subtropical ridge east of Noul is generating light easterly winds over the top the circulation.  The flow is causing modest vertical wind shear and may be the reason why many of the thunderstorms are forming to the west of the center.  If the rainband can wrap completely around the center, then an eye may form.  Noul is likely to remain in an environment that will support further intensification and it could become a typhoon within 24 hours.

Noul is near the western end of a subtropical ridge and it is moving slowly.  The slow motion is likely to continue for another day or so.  After that time, the subtropical ridge is expected to strengthen and extend farther westward.  As the ridge extends westward, it is forecast to steer Noul toward the west-northwest later this week.

On the projected track Noul will move almost directly over Yap on Tuesday.  It could be near typhoon intensity at that time and bring wind and heavy rain.

 

TD 06W Intensifies Into Tropical Storm Noul East of Yap

The center of circulation in Tropical Depression 06W became more well defined on Sunday and the system was upgraded to Tropical Storm Noul.  At 10:00 p.m. EDT on Sunday the center of Tropical Storm Noul was located at latitude 9.7°N and longitude 140.3°E which put it about 150 miles east of Yap and about 360 miles east-northeast of Palau.  Noul was moving toward the northwest at 7 m.p.h.  The maximum sustained wind speed was 40 m.p.h. and there were gusts to 55 m.p.h.  The minimum surface pressure was 996 mb.

Noul is moving over water where the Sea Surface Temperatures are near 29°C.  An upper level ridge northeast of the tropical storm is producing some southeasterly winds over the top of Noul.  However, the vertical wind shear appears to be decreasing.  More thunderstorms developed close to the center of circulation in recent hours and a primary rainband appears to be wrapping around the northern side of the storm.  These are indications of a tropical cyclone that is becoming more well organized.  The increased convection near the center is contributing to well developed upper level divergence on the western and northern portions of the circulation.  Noul will be moving through an environment favorable for intensification.  Wind speeds are likely to increase and a period of rapid intensification is possible once the circulation is more well organized.  Noul could become a typhoon in a day or two and it could become the equivalent of a major hurricane later this week.

Noul is at the western end of a subtropical ridge which is steering it slowly toward the northwest.  It could continue to move slowly for another 24 hours or so.  After that time the subtropical ridge is forecast to extend farther west and begin to steer Noul on a west-northwesterly track.  The projected track would take Noul in the general direction of the northern Philippines.  The center of Noul is forecast to pass just north of Yap and it could bring wind and heavy rain when it does.

 

Tropical Depression 06W Forms Southeast of Yap

A low level circulation with a primary spiral band developed within a broad area of thunderstorms and the system was classified as Tropical Depression 06W on Saturday night.  At 10:00 p.m. EDT on Saturday night the center of Tropical Depression 06W was located at latitude 7.5°N and longitude 141.2°E which put it about 240 miles southeast of Yap and about 430 miles east of Palau.  06W was moving toward the west at 7 m.p.h.  The maximum sustained wind speed was 35 m.p.h. and there were gusts to 50 m.p.h.  The minimum surface pressure was 1004 mb.

Tropical Depression 06W is an environment favorable for further intensification.  It is over Sea Surface Temperatures that are warmer than 28°C and it will be able to extract plenty of energy from the ocean along its path.  An upper level ridge northeast of the circulation is generating some easterly winds over the top of it, but the vertical wind shear is only likely to slow the rate of intensification.  Tropical Depression 06W is likely to become a tropical storm on Sunday and it could become a typhoon in several days.

A subtropical ridge is steering 06W toward the west and it is expected to continue to steer it in a generally west-northwesterly motion during the next day or so.  The movement could slow as 06W nears the western end of the subtropical ridge.  The eastern end of a second subtropical ridge located farther west could take over as the primary steering mechanism in two or three days.  In that scenario Tropical Depression 06W would continue to move toward the northern Philippines.

Tropical Depression 06W could be nearing Yap in 24 to 30 hours.  It is likely to be a tropical storm at that time and it could bring some wind and rain to Yap.

 

Tropical Cyclone Solo Passing Near New Caledonia

The center of Tropical Cyclone Solo is passing near New Caledonia.  At 10:00 p.m. EDT on Saturday the center of Tropical Cyclone Solo was located at latitude 19.7°S and longitude 164.6°E which put it about 200 miles northwest of Noumea, New Caledonia.  Solo was moving toward the southeast at 11 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.

Strong northwesterly winds in the upper levels are generating significant vertical wind shear over the top of Solo.  The strong upper level winds are blowing the tops of thunderstorms to the southeast side of the circulation.  The wind shear is disrupting the circulation and the low level center is exposed on visible satellite images.  Solo is weakening and that trend is likely to continue as it moves farther southeast.

Tropical Storm Maysak Making Landfall in Luzon

Typhoon Maysak moved into an area of drier air and weakened to a tropical storm on Saturday before making landfall in Luzon.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Maysak was located at latitude 16.7°N and longitude 122.0°E which put it about 20 miles southeast of Cauayan and about 160 miles northeast of Manila, Philippines.  Maysak was moving toward the northwest 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 is moving inland over Luzon.  The combination of the mountains in northern Luzon and drier air will cause Maysak to continue to weaken.  Even as the wind speeds decrease, air flowing up the sides of mountains will enhance the rainfall and create the potential for localized flooding and mudslides.  If a closed circulation still exists, it will be much weaker when it emerges over the South China Sea on Sunday.

Typhoon Maysak Nearing Luzon

Typhoon Maysak maintained its heading toward Luzon on Friday and it is about 24 hours away from making landfall.  At 5:00 p.m. EDT on Friday the center of Typhoon Maysak was located at latitude 14.6°N and longitude 127.2°E which put it about 200 miles east-northeast of Catanduanes Island and about east-southeast of Luzon.  Maysak was moving toward the west at 15 m.p.h.  The maximum sustained wind speed was 95 m.p.h. and there were gusts to 115 m.p.h.  The minimum surface pressure was 963 mb.

An upper level trough that was causing vertical wind shear over Maysak moved eastward on Friday and the wind shear over the typhoon decreased.  Infrared satellite imagery indicates that more convection developed near the core of Maysak and the upper level divergence has increased in recent hours.  The additional convection appears to have slowed the weakening of the circulation.  Maysak will remain over warm Sea Surface Temperatures as it approaches Luzon and so it will likely still be a typhoon when it makes landfall there.  If new thunderstorms continue to develop near the center of circulation, then some intensification may be possible before landfall.

A subtropical ridge is steering Maysak toward the west-northwest and that motion is expected to continue.  On the projected track Maysak would make landfall in Luzon in 24 to 36 hours.  It has the potential to bring strong winds and locally heavy rain to parts of Luzon.  The locally heavy rain will also create the conditions that could produce mudslides in some areas.