Monthly Archives: April 2015

Tropical Cyclone Quang Intensified Rapidly Into Equivalent of a Major Hurricane

Tropical Cyclone Quang intensified very rapidly on Wednesday and it reached an intensity equivalent to a major hurricane.  At 10:00 p.m. EDT on Wednesday the center of Tropical Cyclone Quang was located at latitude 17.0°S and longitude 109.2°E which put it about 460 miles northwest of Exmouth and about 610 miles north-northwest of Carnarvon, Australia.  Quang was moving south-southeast at 6 m.p.h.  The maximum sustained wind speed was 130 m.p.h. and there were gusts to 160 m.p.h.  The minimum surface pressure was 940 mb.

As Quang moved across very warm Sea Surface Temperatures (SSTs), the upper level winds eased enough to allow it to intensify very rapidly.  Thunderstorms around the eyewall transported mass upward and generated upper level divergence in all directions, which allowed the surface pressure to decrease quickly.  The decrease in surface pressure generated the rapid increase in wind speed.    Quang is a small tropical cyclone and small tropical cyclones can intensify and weaken more quickly than larger storms.  Quang may have peaked in intensity.  As it moves farther south it will move over cooler SSTs.  Upper level wind speeds will increase along the projected track creating more vertical wind shear.  In addition, it appears that some drier air may be entering the northwestern part of the circulation.  The combination of cooler SSTs, more wind shear and drier air is likely to weaken Quang significantly before it reaches the coast of Western Australia.

Quang is moving around the western end of a subtropical ridge.  As it moves toward higher latitudes, westerly winds are likely to steer it more toward the southeast.  Quang could be approaching the coast of Western Australia between Onslow and Denham in about 48 to 60 hours.

 

Tropical Cyclone Quang Forms Northwest of Australia

After several quiet weeks in the tropics a low level circulation developed in an area of thunderstorms northwest of Australia and the system was classified as Tropical Cyclone Quang (24S) on Tuesday.  At 10:00 p.m. EDT on Tuesday the center of Tropical Cyclone Quang was located at latitude 15.2°S and longitude 109.7°E which put it about 550 miles northwest of Exmouth, Australia.  Quang was moving toward the southwest at 6 m.p.h.  The maximum sustained wind speed was 45 m.p.h. and there were gusts to 65 m.p.h.  The minimum surface pressure was 997 mb.

Tropical Cyclone Quang developed over an area where the Sea Surface Temperatures (SSTs) are near 30°C.  A subtropical ridge to the east of Quang is generating some northeasterly winds over the circulation in the upper levels.  The resulting vertical wind shear is slowing the intensification of the circulation.  However, satellite imagery indicates that Quang is becoming more well organized.  A primary rainband has wrapped most of the way around the center of circulation and an eye may be forming.  Thunderstorms near the center of circulation are increasing the upper level outflow, especially on the southern side of Quang.  Further intensification is likely and Quang could reach hurricane intensity in 24 to 48 hours.  Eventually, when Quang moves farther south, it will move over cooler SSTs.  Vertical wind shear is also likely to increase at the same time, and Quang is likely to weaken as it approaches Western Australia.

Tropical Cyclone Quang is moving around the western end of the subtropical ridge.  As it reaches the western end of the ridge, it is likely to take a more southerly track on Wednesday.  By Thursday westerly winds are forecast to begin to steer Quang to the southeast.  On its projected track, Quang would approach the coast of Western Australia in about three days.  If it weakens as expected, Quang would bring some wind and rain when it moves across Western Australia.

Tropical Cyclone Solo Passing Near New Caledonia

The center of Tropical Cyclone Solo is passing near New Caledonia.  At 10:00 p.m. EDT on Saturday the center of Tropical Cyclone Solo was located at latitude 19.7°S and longitude 164.6°E which put it about 200 miles northwest of Noumea, New Caledonia.  Solo was moving toward the southeast at 11 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.

Strong northwesterly winds in the upper levels are generating significant vertical wind shear over the top of Solo.  The strong upper level winds are blowing the tops of thunderstorms to the southeast side of the circulation.  The wind shear is disrupting the circulation and the low level center is exposed on visible satellite images.  Solo is weakening and that trend is likely to continue as it moves farther southeast.

Tropical Cyclone Solo (23P) Intensifying Slowly Over the Coral Sea

Tropical Cyclone Solo (23P) intensified slowly over the Coral Sea on Friday.  At 6:00 p.m. EDT on Friday the center of Tropical Cyclone Solo was located at latitude 17.1°S and longitude 161.1°E which put it about 470 miles northwest of Noumea, New Caledonia and about 470 miles west of Port Vila, Vanuatu.  Solo was moving toward the south-southeast at 13 m.p.h.  The maximum sustained wind speed was 60 m.p.h. and there were gusts to 80 m.p.h.  The minimum surface pressure was 983 mb.

Solo is moving over warm Sea Surface Temperatures, but an upper level high to the east of it is producing northerly winds over the top of the circulation.  The vertical wind shear is causing more of the stronger thunderstorms to be located south of the center and it is inhibiting the intensification of Solo.  As a result it is intensifying slowly and that trend is expected to continue for the next day or two.  Eventually, when Solo moves to a higher latitude, stronger upper level winds will create more vertical wind shear and weaken it.

Solo is moving around the western end of a subtropical ridge.  As it gets farther south, Solo is expected to move more toward the southeast.  On its projected track, Solo would approach New Caledonia in about 36 hours.  It could be near hurricane intensity at that time.  Solo could bring strong winds and heavy rainfall to New Caledonia when it moves past.

Tropical Cyclone 23P Organizes Rapidly Over the Coral Sea

A well organized circulation developed rapidly within an area of thunderstorms over the Coral Sea and the system was designated Tropical Cyclone 23P.  At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone 23P was located at latitude 14.4°S and longitude 160.5°E which put it about 670 miles northwest of Noumea, New Caledonia and about 600 miles west-northwest of Port Vila, Vanuatu.  It was moving toward the southwest 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.

Tropical Cyclone 23P is located in an area where the upper level winds are light.  That allowed thunderstorms to develop and wrap around the core of the circulation.  Upper level divergence is pumping out mass in all directions and the pressure is decreasing.  The tropical cyclone is over Sea Surface Temperatures which are near 30°C, which means there is plenty of energy in the upper ocean to support further intensification.  Tropical Cyclone 23P could reach hurricane intensity in a day or two.

The tropical cyclone is moving around the western end of a subtropical ridge, which is steering it toward the southwest.  As it moves around the end of the ridge, it will turn more toward the southeast.  On its expected track Tropical Cyclone 23P could approach New Caledonia in 48 to 72 hours.

Tropical Storm Maysak Making Landfall in Luzon

Typhoon Maysak moved into an area of drier air and weakened to a tropical storm on Saturday before making landfall in Luzon.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Maysak was located at latitude 16.7°N and longitude 122.0°E which put it about 20 miles southeast of Cauayan and about 160 miles northeast of Manila, Philippines.  Maysak was moving toward the northwest 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 is moving inland over Luzon.  The combination of the mountains in northern Luzon and drier air will cause Maysak to continue to weaken.  Even as the wind speeds decrease, air flowing up the sides of mountains will enhance the rainfall and create the potential for localized flooding and mudslides.  If a closed circulation still exists, it will be much weaker when it emerges over the South China Sea on Sunday.

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.