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.

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 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.

Tropical Storm Bavi is moving rapidly toward Guam.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Bavi was located at latitude 13.8°N and longitude 148.7°E which put it about 100 miles east-northeast of Guam.  Bavi was moving toward the west at 18 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.

Bavi is moving over water where the Sea Surface Temperatures are around 27.5°C.  So, there is sufficient energy to support intensification.  Moderate easterly winds in the upper levels are generating vertical wind shear over the circulation.  Most of the thunderstorms have been located in the western half of the circulation.  However, recent satellite imagery indicates that there may be more thunderstorms forming near the core of the circulation.  The rapid movement of the storm and the wind shear are likely to limit potential intensification.

A subtropical ridge to the north of Bavi is steering it rapidly to the west and that motion is expected to continue.  Bavi will move  near Guam within a few hours and the core of the circulation could pass near Rota, Tinian and Saipan.  It is likely to bring gusty winds and locally heavy rains as it passes.  The subtropical ridge is expected to steer Bavi or its remnants toward the Philippines during the next few days.

Tropical Storm Bavi continued to move rapidly toward the west-northwest toward Guam on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Bavi was located at latitude 10.7°N and longitude 157.6°E which put it about 880 miles east-southeast of Guam.  Bavi was moving toward the west-northwest at 17 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.

Strong easterly winds in the upper levels are creating vertical wind shear and are inhibiting intensification of Bavi.  The wind shear is also causing most of the thunderstorms to be located on the western side of the circulation.  Thus, Bavi is not well organized at the current time.  However, Bavi is moving over warm Sea Surface Temperatures and it could strengthen slowly as it moves farther west, if the wind shear decreases.

A strong subtropical ridge to the north of Bavi is steering it rapidly westward.  Bavi could be in the vicinity of Guam in about 48 hours.  The ridge is expected to continue to steer Bavi westward after it moves past Guam and it could approach the Philippines in a few days.