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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.

Typhoon Maysak Weakening As It Moves Toward Luzon

Typhoon Maysak weakened slowly on Thursday as it moved in the direction of Luzon.  At 11:00 p.m. EDT on Thursday the center of Typhoon Maysak was located at latitude 14.3°N and longitude 130.6°E which put it about 420 miles east of Catanduanes Island and about 580 miles east-southeast of Luzon.  Maysak was moving toward the west-northwest at 11 m.p.h.  The maximum sustained wind speed was 110 m.p.h. and there were wind gusts to 130 m.p.h.  The minimum surface pressure was 948 mb.

An upper level trough passing north of Maysak is generating vertical wind shear which is causing the typhoon to weaken slowly.  The western side of the trough contains some drier air which is also getting into the circulation of Maysak.  The drier air is reducing the amount of latent energy available to maintain the circulation.  So, even though Maysak is still over warm Sea Surface Temperatures it is slowly weakening.  The wind shear may decrease after the upper level trough moves east of Maysak, but as the typhoon moves further west, it will still encounter drier air.  As a result, Maysak it expected to continue to slowly weaken.

A subtropical ridge is steering Maysak in a west-northwesterly direction.  The upper level trough has temporarily weakened the ridge and Maysak is moving a bit more toward the northwest.  After the upper level trough moves east of the typhoon, it is expected to resume a west-northwesterly motion.  The expected track would bring Maysak close to Luzon in 36 to 42 hours.  Maysak is expected to be a low end typhoon or strong tropical storm when it nears Luzon.  It will be capable of producing some stronger winds and locally heavy rainfall as it moves across Luzon.

Typhoon Maysak Weakens As It Moves Away from Yap

Typhoon Maysak weakened below Super Typhoon intensity on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Typoon Maysak was located at latitude 12.6°N and longitude 133.5°E which put it about 300 miles northwest of Yap and about 780 miles east-southwest of Luzon.  Maysak was moving toward the west-northwest at 10 m.p.h.  The maximum sustained wind speed was 135 m.p.h. and there were wind gusts to 160 m.p.h.  The minimum surface pressure was 937 mb.

Maysak appears to have gone through an eyewall replacement cycle on Wednesday.  A rainband wrapped around the existing eyewall to create to concentric eyewalls.  As more air started to converge and rise in the outer eyewall, the inner eyewall which had the stronger winds weakened.  As the inner eyewall dissipated, the core of Maysak became enlarged and it now has an eye with a diameter of 32 miles.  The maximum wind speed decreased as part of the eyewall replacement process.  If the current eye were to shrink, the wind speed could increase again because it is still over warm Sea Surface Temperatures.  However, as Maysak moves toward the west-northwest it is moving toward an area where the upper level winds are stronger.  An upper level trough located northwest of Maysak is generating stronger upper level winds, which will increase the vertical wind shear.  Maysak could intensify on Thursday, but the wind shear is expected to weaken it during the next several days.

A subtropical ridge is steering Maysak toward the west-northwest.  The upper level trough is expected to make it move a little more toward the north during the next 24 to 48 hours.  On its expected track, Maysak could be approaching Luzon in about 60 hours.  Maysak is expected to still be a typhoon when it approaches Luzon.  It could bring strong winds and locally heavy rains.

Super Typhoon Maysak Passing North of Yap

The core of Super Typhoon Maysak passed north of Yap on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Super Typhoon Maysak was located at latitude 10.7°N and longitude 137.2°E which put it about 90 miles north-northwest of Yap and about 1000 miles east-southeast of Luzon.  Maysak was moving toward the west-northwest at 13 m.p.h.  The maximum sustained wind speed was 160 m.p.h., which made Maysak the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  There were gusts to 195 m.p.h. and the minimum surface pressure was 918 mb.

Maysak continues to exhibit a very impressive structure.  It is very symmetrical and there is strong upper level outflow in all directions.  Some satellite imagery suggests the circulation may have developed concentric eyewalls and that could mean an eyewall replacement is underway.  If so, the intensity could fluctuate while the inner eyewall weakens and the inflow becomes focused on the outer eyewall.  The overall environment around Maysak is very supportive of an intense tropical cyclone.  The upper level winds are relatively light and it is over warm Sea Surface Temperatures.  Maysak could maintain super typhoon intensity for another day or two.  It could move into an area of stronger upper level winds in several days, which would increase the vertical wind shear.

A subtropical ridge is expected to continue to steer Maysak toward the west-northwest.  On the projected track, Maysak could approach Luzon in about four days.  Even if it weakens, it is likely to be a typhoon when it nears the northern Philippines.  It has the potential to bring strong winds and locally heavy rains.

Maysak Near Super Typhoon Intensity East of Yap

Maysak intensified rapidly on Monday and it is near Super Typhoon intensity.  At 11:00 a.m. EDT on Monday the center of Typhoon Maysak was located at latitude 9.6°N and longitude 142.5°E which put it about 300 miles east of Yap and about 1450 miles east-southeast of Luzon.  Maysak was moving toward the west-northwest at 14 m.p.h.  The maximum sustained wind speed was 140 m.p.h. and there were gusts to 170 m.p.h.  The minimum surface pressure was 929 mb.

Maysak moved into an area of light upper level winds on Monday, which allowed the well-developed upper level divergence to pump out mass in all directions.  As a result, the surface pressure decreased rapidly and the wind speed increased quickly.  The circulation is very symmetrical and Maysak has a tight inner core.  The eye is exhibiting a stadium effect on visible satellite images which is indicative of a very strong tropical cyclone.  Maysak continues to move over warm Sea Surface Temperatures and it could intensify into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  When tropical cyclones get as strong as Maysak is, they often go through eyewall replacement cycles which result in periodic fluctuations of intensity.  On its west-northwesterly track Maysak will gain latitude and it could move into an area of stronger vertical wind shear in 24 to 48 hours.  Increased wind shear would weaken it.

A strong subtropical ridge is steering Maysak toward the west-northwest and that motion is expected to continue in the short term.  The ridge may weaken somewhat in about 24 hours and that would allow Maysak to move in a more northwesterly direction for a day or two.  Later in the week a subtropical ridge is expected to build again and steer Maysak more toward the west again.  On its projected track, the center of Maysak would pass north of Yap in about 24 hours.  However, residents should monitor the typhoon closely in case it takes a more southerly track which would bring the core of stronger winds closer to Yap.  Over the longer term, Maysak could approach Luzon and the northern Philippines in five or six days and it could still be a typhoon at that time.

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 Cyclone Nathan Weakening Over Northern Australia

The center of Tropical Cyclone Nathan moved inland between Maningrida and Goulburn Island on the northern coast of Australia on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Cyclone Nathan was located at latitude 12.2°S and longitude 133.5°E which put it about 30 miles east-northeast of Gunbalanya, about 45 miles south of Goulburn Island and about 210 miles east of Darwin, Australia.  Nathan was moving toward the southwest at 8 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.

A combination of factors contributed to the weakening of Nathan.  As the center of circulation moved inland, the clockwise flow pulled in drier air from the interior of Australia.  The drier air reduced the number of thunderstorms and decreased the amount of latent energy released in the remaining thunderstorms.  Since the release of latent energy drives the circulation in a tropical cyclone, the wind speed has been decreasing as well.  In addition, northerly winds in the upper levels are creating moderate vertical wind shear over the top of Nathan.  The wind shear is displacing many of the remaining thunderstorms to the south side of the circulation.  The asymmetrical development of thunderstorms has weakened the inner core of the circulation.  As long as the center of circulation remains over land, it is likely to weaken further.

A subtropical ridge to the south of Nathan is expected to steer it in a mainly westerly direction.  The projected track would take the center of Nathan south of Darwin and keep it over land for about another 36 hours.  The circulation could be fairly weak by the time it moves back over water west of Darwin.  The water west of Darwin is warm and so, it is possible that more thunderstorms could develop, if there is a coherent circulation when the system moves back over the water.

Tropical Cyclone Nathan Moving Parallel to the Northern Coast of Australia

The center of Tropical Cyclone Nathan moved across the northeastern portion of Arnhem Land and it has emerged over the Arafura Sea.  At 10:00 p.m. EDT on Sunday the center of Tropical Cyclone Nathan was located at latitude 11.6°S and longitude 134.7°E which put it about 45 miles northeast of Maningrida, about 35 miles north-northwest of Milingimbi and about 280 miles east-northeast of Darwin, Australia.  Nathan 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 95 m.p.h.  The minimum surface pressure was 974 mb.

The core of the circulation was relatively intact when the center of Nathan moved back over water and it had an apparent eye on some satellite imagery and radar displays.  The surface temperatures are quite warm in the Arafura Sea and thunderstorms continue to develop around the southern and western sides of the circulation.  Less convection is occurring on the eastern side of Nathan.  It is possible the moving across land and proximity to the coast is allowing some drier air to be entrained into the circulation.  Light westerly winds in the upper levels may also be creating some vertical wind shear.  The intact core and warm water could allow Nathan to intensify somewhat on Monday.

Nathan is being steered toward the west by a subtropical ridge located to its south.  The ridge is expected to continue to steer Nathan in a general westerly direction for another 24 hours.  The projected track would keep the center of circulation over water.  The ridge is expected to weaken a bit in a day or so, which could allow Nathan turn southwestward and make another landfall on the north coast of Australia.  The southwesterly turn could produce a landfall between Maningrida and Croker Island.

Nathan has a relatively small circulation but it is strong enough to cause wind damage and a significant storm surge near where the center makes landfall.  It could also produce locally heavy rainfall and flooding in inland areas.