Tag Archives: Yap

TD 03W Intensifies Into Tropical Storm Muifa

Tropical Depression 03W intensified into Tropical Storm Muifa on Tuesday as it moved slowly northwest of Yap.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Muifa was located at latitude 13.3°N and longitude 134.6°E which put it about 335 miles (540 km) northwest of Yap.  Muifa was moving toward the west-northwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1000 mb.

The circulation of Tropical Cyclone Muifa is not well organized.  There is a well defined low level center.  However, almost all of the showers and thunderstorms are in a cluster east of the low level center.  There are almost no showers and thunderstorms in the western half of the circulation.  Few well defined rainbands are evident in the eastern half of the circulation.  The cluster of thunderstorms east of the center of circulation is generating some upper level divergence which appears to be pumping mass out to the northwest of the tropical storm.

Tropical Storm Muifa will be moving through an environment that will be marginally favorable for intensification.  Muifa will move over water where the Sea Surface Temperature will be near 29.5°C.  A subtropical ridge east of Muifa is producing easterly winds which are blowing toward the tropical storm.  Tropical Storm Muifa is currently south of the upper level westerly winds in the middle latitudes.  Muifa is currently in a region where the upper level winds are weaker and the vertical wind shear is moderate.  Areas of stronger vertical wind shear surround the tropical storm.  Tropical Storm Muifa could intensify a little more during the next 24 hours before it reaches an area where the shear is stronger.

Tropical Storm Muifa is moving around the western end of the subtropical ridge to its east and the steering winds are weak.  As a result Muifa is moving slowly toward the west-northwest.  A gradual turn toward the north is forecast as Tropical Storm Muifa moves around the end of the ridge.  Muifa will reach an area of westerly winds as it moves farther north and the tropical storm is forecast to recurve toward the northeast.

Tropical Depression 03W Forms Northwest of Yap

Tropical Depression 03W formed northwest of Yap on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Depression 03W was located at latitude 12.5°N and longitude 135.2°E which put it about 260 miles (420 km) northwest of Yap.  The depression was moving toward the west at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1003 mb.

A cluster of thunderstorms developed southeast of the Marianas during the weekend.  The cluster moved slowly toward the west-northwest and the circulation gradually exhibited signs of greater organization.  Satellite imagery indicated that a center of circulation formed in the lower levels of the circulation and the system was designated as Tropical Depression 03W on Monday.

The circulation of Tropical Depression 03W is still organizing.  Although there is a distinct low level center, the distribution of showers and thunderstorms is asymmetrical.  Many of the showers and thunderstorms are forming east of the center of circulation.  There are few showers and thunderstorms in the western half of the circulation.  Thunderstorms just to the east of the center of the circulation are generating some upper level divergence that is pumping out mass to the west and north of the center of circulation.

Tropical Depression 03W will be moving through an environment that will be somewhat favorable for intensification.  It will move over water where the Sea Surface Temperature will be near 30°C.  A ridge of high pressure east of the depression is producing easterly flow that is blowing toward the depression.  The flow may be pushing the lower part of the circulation to the west of the middle and upper portions.  Vertical wind shear could be an inhibiting factor.  Some intensification is forecast during the next day or two and the depression could intensify into a tropical storm.

The ridge of the depression is steering it toward the west.  The depression is expected to turn toward the northwest when it reaches the western end of the depression in a day or so.

Tropical Storm Nock-ten Forms Near Yap

Tropical Storm Nock-ten formed near Yap on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Tropical Storm Nock-ten was located at latitude 9.1°N and longitude 138.4°E which put it about 85 miles (140 km) southeast of Yap.  Nock-ten was moving toward the northwest at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 993 mb.

A distinct center of circulation developed in an area of thunderstorms near Yap and the system was named Tropical Storm Nock-ten.  The circulation of Nock-ten is still organizing.  A small well defined center exists at the core of the circulation.  A band of thunderstorms is beginning to wrap around the center.  Several additional bands of thunderstorms formed in the northern part of the circulation.  Thunderstorms near the center are beginning to generate upper level divergence which is pumping mass out to the west of the center.

Tropical Storm Nock-ten will move through an environment that is moderately favorable for intensification.  Nock-ten will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge north of Nock-ten is producing southeasterly winds which are blowing across the top of the tropical storm.  Those winds are preventing upper level divergence to east of Nock-ten.  Those winds are also causing moderate vertical wind shear which is slowing the rate of intensification.  When Nock-ten moves a little farther west, the vertical wind shear is expected to diminish and faster intensification could occur.  Nock-ten could intensify into a typhoon during the next several days.

A subtropical ridge north of Nock-ten is steering the tropical storm toward the northwest.  That general motion is expected to continue for another day or two.  The ridge could strengthen during the weekend and it could turn Nock-ten more toward the west in a couple of days.  On its anticipate track Tropical Storm Nock-ten could approach the Philippines in three or four days.  Nock-ten could be a typhoon by the time it reaches the Philippines.

Tropical Storm Melor Forms West of Yap

A well defined center of circulation developed within an area of thunderstorms on Friday and the system was designated Tropical Storm Melor (28W).  At 4:00 p.m. EST on Friday the center of Tropical Storm Melor was located at latitude 10.4°N and longitude 134.9°E which put it about 210 miles (335 km) north-northeast of Koror, Palau.  Melor was moving toward the west-northwest at 17 m.p.h. (27 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 997 mb.

Tropical Storm Melor organized quickly on Friday.  A rainband wrapped about three quarters of the way around the center of circulation and an eyewall may be forming.  Outer rainbands are also rotating around the center of circulation.  Thunderstorms around the center of circulation are producing upper level divergence.

The environment around Tropical Storm Melor is favorable for further intensification.  It is over water where the Sea Surface Temperatures are warm.  An upper level ridge is producing light southerly winds over the top of Melor, but there is only modest vertical wind shear.  Once a fully developed eye forms at the center of Melor, the tropical storm could intensify rapidly.  Melor could become a typhoon on Saturday and it could become the equivalent of a major hurricane in 48 to 73 hours.

A subtropical ridge north of Melor is steering the tropical storm toward the west-northwest and that general motion is expected to continue during the next two or three days.  On its anticipated track, Melor could reach the Central Philippines within 72 hours.  It could be a strong typhoon at that time.

Typhoon In-Fa Passes North of Yap

The center of Typhoon In-Fa passed north of Yap on Saturday.  At 10:00 p.m. EST on Saturday the center of Typhoon In-Fa was located at latitude 13.7°N and longitude 136.0°E which put it about 285 miles (465 km) north-northwest of Yap.  In-Fa was moving toward the west-northwest at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 944 mb.

The structure of Typhoon In-Fa deteriorated slightly on Saturday, but it remains the equivalent of a major hurricane.  Fewer thunderstorms formed in the northwestern quadrant of the circulation and there are indications that a gap may have opened on the northwestern side of the eyewall.  It is possible that some drier air could have been pulled into that part of the circulation.  However, an eye may still exist at the center of circulation and there are multiple bands around the eastern and southern sides of the typhoon.

Typhoon In-Fa is moving over water where the Sea Surface Temperature is near 29°C.  The upper level winds over the top of the circulation are light and there is not much vertical wind shear over the core of the typhoon.  Typhoon In-Fa could maintain its intensity or weaken slowly on Sunday.  When it moves farther north, it will encounter stronger southwesterly winds which will increase the vertical wind shear.  When the wind shear increases, the rate of weakening will increase.

A subtropical ridge is steering Typhoon In-Fa toward the west-northwest and that general motion is expected to continue for another day or so.  In-Fa could reach the western end of the ridge and turn northward on Monday.  In 36 to 48 hours the southwesterly upper level winds will start to push the typhoon toward the northeast.  On its anticipated track Typhoon In-Fa could be near Iwo To in about four days.

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.