Tag Archives: Yap

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.

 

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.