Tag Archives: Yap

In-Fa Intensifies Back Into a Typhoon and a Tropical Storm Warning Is Issued for Guam

In-Fa intensified rapidly back into a typhoon on Thursday and a Tropical Storm Warning was issued for Guam.  At 10:00 p.m. EDT on Thursday the center of Typhoon In-Fa was located at latitude 10.1°N and longitude 148.1°E which put it about 365 miles (590 km) southeast of Guam.  In-Fa was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 954 mb.

After weakening slightly on Wednesday, In-Fa intensified rapidly back into a typhoon on Thursday.  Typhoon In-Fa has a compact tightly wound structure with a small inner core and a tiny pinhole eye.  The strongest winds are contained in the ring of thunderstorms around the pinhole eye.  Many of the strongest thunderstorms outside the eyewall are located southwest of the eye, but there are spiral bands in all quadrants of the storm.  The storms around the core of Typhoon In-Fa are generating upper level divergence in all directions.

Typhoon In-Fa is an environment favorable for intensification.  It is over water where the Sea Surface Temperature is near 29°C.  The upper level winds around In-Fa are light and there is not much vertical wind shear.  In-Fa is likely to intensify more during the next day or two.

A subtropical ridge north of In-Fa is steering the typhoon to the west-northwest and that general motion is expected to continue for another 48 hours.  On its anticipated track the center of In-Fa is likely to pass about 100 miles (160 km) to 150 miles (240 km) south of Guam in about 18 to 24 hours.  The center of Typhoon In-Fa is likely to pass about 200 miles (320 km) northeast of Yap in about 48 hours.

Tropical Storm Koppu Forms North of Yap

In spite of significant vertical wind shear a surface circulation has been consolidating inside an area of thunderstorms north of Yap.  The system has been designated Tropical Storm Koppu.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Koppu was located at latitude 15.7°N and longitude 137.1°E which put it about 430 miles (690 km) north of Yap.  Koppu was moving toward the west at 14 m.p.h. (23 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 993 mb.

Significant vertical wind shear is inhibiting the organization of Tropical Storm Koppu.  An upper level ridge north of Koppu is generating strong northeasterly winds over the top of the tropical storm.  The vertical wind shear is causing most of the strong thunderstorms to be located southwest of the center of circulation.  The only other deep convection is occurring in a band that is west of the core of the circulation.

Koppu is over water where the Sea Surface Temperature is near 30°C and so there is plenty of energy in the upper ocean.  The wind shear will inhibit intensification for another 24 to 48 hours before it starts to subside.  Koppu could intensify much more quickly later this week when it moves into an area where the upper level winds are lighter.  Koppu could become a typhoon withing 36 to 48 hours and it could be a strong typhoon by the end of the week.

A subtropical ridge is steering Tropical Storm Koppu quickly to the west.  That general motion is expected to continue for the rest of the week.  On its anticipated track Koppu could be approaching northern Luzon in about three or four days.  It could be a significant typhoon by that time.

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.

 

Typhoon Maysak Passing South of Guam and Intensifying

Typhoon Maysak continued to intensify on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Maysak was located at latitude 8.4°N and longitude 146.9°E which put it about 370 miles south-southeast of Guam and about 600 miles east of Yap.  Maysak was moving toward the west at 17 m.p.h.  The maximum sustained wind speed was 100 m.p.h. and there were gusts to 125 m.p.h.  The minimum surface pressure was 959 mb.

Maysak is moving over warm Sea Surface Temperatures and it has plenty of energy available to support further intensification.  Upper level winds blowing from the southeast are creating some wind shear, but it is not enough to stop the intensification.  The circulation is symmetrical and it has well developed upper level outflow.  Maysak is expected to intensify for another day or two and it could become the equivalent of a major hurricane.

A subtropical ridge is steering Maysak on a track that is moving it just north of due west.  This motion is expected to continue for another 24 to 48 hours.  After that time the ridge is expected to weaken slightly and Maysak is expected to move more toward the northwest.  The center of Maysak should pass south of Guam during the next 12 hours.  On the projected track Maysak would approach Yap in about 36 hours.  It could be a very strong typhoon by that time and it would pose a distinct risk for Yap.

Typhoon Maysak Crossing Chuuk

The core of Typhoon Maysak is passing very near Chuuk.  At 11:00 p.m. EDT on Saturday the center of Maysak was located at latitude 7.3°N and longitude 151.8°E which put it about 15 miles south-southwest of Chuuk and about 600 miles east-southeast of Guam.  It was moving toward the west at 12 m.p.h.  The maximum sustained wind sped was 80 m.p.h. and there were gusts to 100 m.p.h.  The minimum surface pressure was 971 mb.

Maysak is moving over water where the Sea Surface Temperature is around 29°C.  The upper level winds are blowing from the east, but they are only generating modest amounts of vertical wind shear.  The circulation is very well organized and upper level outflow is pumping out mass in all directions.  In this favorable environment Typhoon Maysak is expected to continue to intensify for another two or three days.

A strong subtropical ridge is steering Maysak toward the west and that motion is expected to continue for another day or two.  The ridge is expected to weaken somewhat later next week and Maysak could move more toward the west-northwest during the middle portion of the week.    On its projected track Maysak would pass south of Guam in about 36 hours and it could be approaching Yap in 48 to 60 hours.

 

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.

 

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.