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Lan Strengthens to a Typhoon East of the Philippines

Tropical Storm Lan strengthened east of the Philippines on Tuesday and the Japan Meteorological Agency designated it a typhoon.  At 5:00 p.m. EDT on Tuesday the center of Typhoon Lan was located at latitude 11.2°N and longitude 132.4°E which put it about 515 miles (830 km) east of the Philippines.  Lan was moving toward the north-northeast at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (150 km/h).  The minimum surface pressure was 976 mb.

The circulation of Typhoon Lan became much more well organized on Tuesday.  Several long rainbands developed in the circulation and other smaller bands formed in the periphery of the typhoon.  The circulation of Typhoon Lan was circular and symmetrical.  Thunderstorms near the core of Lan began to generate strong upper level divergence which was pumping mass away from the typhoon in all directions.  The upper level divergence allowed the surface pressure to decrease and the wind speed to increase.  Lan is a large typhoon.  Winds to tropical storm force extend out about 230 miles (370 km) from the center of circulation.

Typhoon Lan will move through an environment favorable for intensification.  Lan will move over water where the Sea Surface Temperature is near 30°C.  Typhoon Lan will move through an area where the upper level winds will be weak and there will be little vertical wind shear during the next several days.  Typhoon Lan will continue to strengthen and there could be a period of rapid intensification after a well formed eye develops at the center of circulation.

Typhoon Lan was in an area where the steering currents were weak and it moved little on Tuesday.  An upper level ridge north of Lan blocked the typhoon from moving northward.  A weakness is forecast to develop in the ridge and the models are forecasting that Typhoon Lan will move northward during the rest of this week.  On its anticipated track Typhoon Lan will remain east of the Philippines.  Lan could be southeast of Okinawa in three or four days.

Tropical Storm Lan Develops Northwest of Palau

Tropical Storm Lan developed northwest of Palau on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Lan was located at latitude 10.7°N and longitude 132.1°E which put it about 275 miles (445 km) north-northwest of Koror, Palau.  Lan was moving toward the west at 12 m.p.h. (19 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 more distinct center of circulation developed within Tropical Storm Lan, but the low pressure system was still in the process of organizing.  The low level center of circulation of Lan was at the end of a long rainband that extends from the western periphery around the southern and eastern parts of the tropical storm.  That low level center appeared to be on the northern side of a much larger counterclockwise rotation.  Most of the stronger showers and thunderstorms were occurring in the long rainband.  A few new, thinner bands of showers and thunderstorms seemed to be forming inside the long rainband to west of the center of circulation.

Tropical Storm Lan will be moving through an environment that will be favorable for intensification.  Lan will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge north of Lan is producing easterly winds which were blowing toward the top of the circulation.  There was some vertical wind shear, but it was not strong enough to prevent the intensification of Tropical Storm Lan.  Tropical Storm Lan is likely to intensify more slowly while the circulation organizes.  Once the center of circulation become tighter, then Lan could intensify more quickly.  A period of rapid intensification could occur, if Lan becomes a typhoon and an eye develops.

The ridge north of Lan and the counterclockwise flow to its south are combining to steer the tropical storm toward the west.  Numerical models are indicating that a weakness will develop in the ridge north of Tropical Storm Lan.  If that happens, then the steering current could weaken for 12 to 24 hours and Tropical Storm Lan might not move much.  If the break in the ridge becomes more pronounced, then Tropical Storm Lan could start to move more toward the north.  On its anticipated track Tropical Storm Lan is expected to remain east of the Philippines, but the tropical storm could move closer to the northern Philippines if the forecast weakness in the ridge does not occur.

Typhoon Khanun Makes Landfall in Southern China

Typhoon Khanun made landfall near Zhanjiang in southern China on Sunday.  At 5:00 p.m. EDT on Sunday the center of Typhoon Khanun was located at latitude 20.9°N and longitude 109.3°E which put it about 50 miles (80 km/h) south-southeast of Beihai, China.  Khanun was moving toward the west at 17 m.p.h. (27 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (150 km/h).  The minimum surface pressure was 969 mb.

Typhoon Khanun brought gusty winds and locally heavy rain over coastal sections of southern China on Sunday.  Khanun has weakened since it made landfall.  An upper level ridge centered over eastern China is producing easterly winds which are blowing over the top of the circulation.  Those winds are causing strong vertical wind shear, which is pushing the upper half of the circulation to the west of low level circulation.  The circulation is pulling drier air from Asia into the western part of Typhoon Khanun and the drier air is wrapping around the southern and eastern sides of the circulation.   Interaction with land and strong vertical wind shear will continue to weaken Khanun on Monday.  Khanun will bring rain to southern China and northern Vietnam as it weakens.

Elsewhere over the western North Pacific Ocean Tropical Depression Twentyfive-W formed west of Yap.  At 5:00 p.m. EDT on Sunday the center of Tropical Depression Twentyfive-W was located at latitude 10.3°N and longitude 136.1°E which put it about 125 miles (200 km) west-northwest of Yap.  It was moving toward the north-northwest at 11 m.p.h. (17 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 999 mb.

The circulation of Tropical Depression Twentyfive-W is still organizing.  Most of the showers and thunderstorms are in a primary rainband that wraps around the eastern side of the circulation.  The depression is moving through an area favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is not much vertical wind shear.  Tropical Depression Twentyfive-W is likely to be become a tropical storm during the next 24 hours and it could become a typhoon in a couple of days.  The depression is forecast to move toward the north-northwest as it moves around the western end of a subtropical ridge over the Pacific Ocean.

Typhoon Haima Brings Gusty Winds and Rain to China

The large eye of Typhoon Haima neared the coast of China on Thursday and the typhoon was bringing gusty winds and heavy rain to the area near Hong Kong.  At 11:00 p.m. EDT on Thursday the center of Typhoon Haima was located at latitude 22.6°N and longitude 115.6°E which put it about 105 miles (170 km) east of Hong Kong.  Haima was moving toward the northwest at 18 m.p.h.  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 967 mb.

After the center of Typhoon Haima moved northwest of Luzon, a large eye reformed at the center of the typhoon.  The diameter of the eye is about 60 miles (95 km).  The eye is surrounded by a thin ring of thunderstorms and multiple rainbands.  Haima is a large typhoon.  Winds to typhoon force extend out about 70 miles (110 km) from the center and winds to tropical storm force extend out about 240 miles (390 km) from the center.

Typhoon Haima is moving around the western end of a subtropical ridge which is steering it toward the northwest.  Haima is expected to turn more toward the north when it reaches the coast of China.  An upper level trough over eastern Asia will begin to steer Haima toward the northeast on Friday.  On its anticipated track the eye of Typhoon Haima will make landfall on the coast of China near Haifeng and Lufeng.

The Hurricane Intensity Index (HII) for Typhoon Haima is 13.9.  The Hurricane Size Index (HSI) is 27.0 and the Hurricane Wind Intensity Size Index (HWISI) is 40.9.  These indices indicate that Typhoon Haima is capable of causing widespread serious wind damage.  Typhoon Haima will also generate a serious storm surge north of where the eye makes landfall and the wind blows the water toward the coast.  Haima will also bring heavy rain and a threat of floods to Guangdong, Jiangxi and Fujian provinces when it moves inland.

Typhoon Haima Producing Strong Winds and Heavy Rain Over Northern Luzon

Typhoon Haima was producing strong winds and heavy rain as it moved across northern Luzon on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Haima was located at latitude 18.2°N and longitude 120.8°E which put it about 10 miles (15 km) east of Laoag, Philippines.  Haima was moving toward the west-northwest at 20 m.p.h. (32 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (235 km/h).  The minimum surface pressure was 946 mb.

The center of Typhoon Haima moved quickly across northern Luzon on Wednesday.  Haima made landfall on northeastern Luzon east of Tuguegarao.  As it moved toward the west-northwest the center of Typhoon Haima passed near Tuao and Dingras.  The center also passed over the Cordillera Central, where it produced very heavy rain in places where the wind was blowing up the slopes of the mountains.

Movement across the mountain ranges in northern Luzon weakened Typhoon Haima and an eye is no longer evident on satellite images.  However, Haima is still a large, powerful typhoon.  Winds to typhoon force extend out 65 miles (105 km) from the center of circulation.  Winds to tropical storm force extend out about 240 miles (390 km) from the center.  The Hurricane Intensity Index (HII) for Haima is 20.6.  The Hurricane Size Index (HSI) is 25.6 and the Hurricane Wind Intensity Size Index (HWISI) is 46.2.  The indices indicate that Typhoon Haima is capable of causing widespread major wind damage.

The core of Typhoon Haima is not as well organized as it was before the typhoon made landfall in Luzon.   Some reorganization of the core could occur when Typhoon Haima moves over the South China Sea.  Haima will move over water where the Sea Surface Temperature is near 29°C.  The upper level winds are weak and Typhoon Haima is still producing strong upper level divergence which is pumping mass away in all directions.  Typhoon Haima could restrengthen somewhat or maintain its intensity after the center moves northwest of the Philippines.  When Haima nears the coast of China, it will approach an upper level trough and vertical wind shear will increase.  So, Typhoon Haima is likely to be on a weakening trend when it makes landfall in China.

Typhoon Haima is moving around the western end of subtropical ridge which is steering it toward the west-northwest.  Typhoon Haima is likely to move more toward the northwest after it leaves Luzon and reaches the end of the ridge.  When Typhoon Haima nears the coast of China, it will move under southwesterly winds caused by an upper level trough over China.  Those winds will turn Haima more toward the north.  On its anticipated track Typhoon Haima could make a landfall in China northeast of Hong Kong in about 36 hours.

Typhoon Haima will continue to produce strong winds and heavy rains over parts of northern Luzon for a few more hours until the core of the typhoon moves northwest of that region.  The heavy rain has the potential to cause floods and mudslides.  Although Typhoon Haima is likely to be weakening when it reaches the coast of China, it will still be capable of producing strong winds, heavy rain, floods and a storm surge along the coast.

Typhoon Haima Equal to Cat. 5 Hurricane, Threatens Luzon

Typhoon Haima intensified into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of Typhoon Haima was located at latitude 15.9°N and longitude 128.4°E which put it about 400 miles (640 km) east of northern Luzon.  Haima was moving toward the west-northwest at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h).  The minimum surface pressure was 919 mb.

Typhoon Haima completed an eyewall replacement cycle and it intensified as the outer eyewall contracted.  Haima is a very well organized, symmetrical typhoon.  Haima has a clear circular eye surrounded by a ring of very strong thunderstorms.  Thunderstorms in the core of Typhoon Haima are generating strong upper level divergence which is pumping away large quantities of mass in all directions.  Winds to typhoon force extend out about 65 miles (105 km) from the center.

Typhoon Haima is moving through a very favorable environment.  It is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is very little vertical wind shear.  Typhoon Haima is moving on a track that is a little to the north of the track taken by Typhoon Sarika.  This means that the core of Haima is moving north of cooler water mixed to the surface by Typhoon Sarika.  Typhoon Haima could intensify more during the next 12 to 24 hours.  However, if another eyewall replacement cycle occurs, then there could be fluctuations in intensity.

A subtropical ridge is steering Typhoon Haima toward the west-northwest and that general motion is expected to continue for several more days.  On its anticipated track the core of Typhoon Haima will approach northern Luzon in about 24 hours.  After Haima moves across Luzon it will reach the western end of the ridge and turn more toward the northwest.  Typhoon Haima could be near the coast of China in 72 hours.

Haima is an extremely dangerous typhoon.  The Hurricane Intensity Index (HII) for Haima is 35.0.  The Hurricane Size Index (HSI) is 21.2 and the Hurricane Wind Intensity Size Index (HWISI) is 56.2.  The indices indicate that Typhoon Haima is capable of causing widespread catastrophic wind damage.  In addition Typhoon Haima will produce very heavy rain over northern Luzon including over some locations hit by Typhoon Sarika a few days ago.  The heavy rain will create the potential for flash floods and mudslides.  Haima will also generate a significant storm surge in locations where the wind pushes the water toward the coast.

Typhoons Sarika and Haima Churning Over Western North Pacific

Typhoons Sarika and Haima churned across the western North Pacific Ocean on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Sarika was located at latitude 17.3°N and longitude 113.7°E which put it about 240 miles (390 km) east-southeast of Hainan Island.  Sarika was moving toward the west at 17 m.p.h. (27 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 970 mb.

At 11:00 p.m. EDT on Sunday the center of Typhoon Haima was located at latitude 13.2°N and longitude 135.9°E which put it about 935 miles (1505 km) east-southeast of Luzon.  Haima was moving toward the west-northwest at 17 m.p.h. (27 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 956 mb.

The circulation of Typhoon Sarika was disrupted somewhat when it crossed northern Luzon.  Thunderstorms around the eye weakened and breaks developed in the eyewall.  More and stronger thunderstorms developed around the center of circulation today and an eye has become more apparent on satellite imagery.  Numerous rainbands are rotating around the rest of the circulation.  Upper level divergence is increasing, which will increase the removal of mass from the core of Typhoon Sarika.

Typhoon Sarika is moving through an environment that is favorable for intensification.  Sarika is moving over water where the Sea Surface Temperature is above 30°C.  The upper level winds are weak and there is little vertical wind shear.  Typhoon Sarika is likely to intensify during the next 24 hours and it could intensify quickly if the eye finishes reforming.

A subtropical ridge is steering Typhoon Sarika toward the west .  Sarika is nearing the western end of the ridge and the typhoon is expected to turn more toward the northwest.  On its anticipated track Typhoon Sarika could be near Hainan Island in about 24 hours.  After it crosses Hainan Island, Marika could approach the coast of northern Vietnam in about two days.  Typhoon Sarika will bring strong winds and very heavy rain to Hainan.  It will weaken when it moves across Hainan, but Sarika could also bring gusty winds and heavy rain to northern Vietnam and parts of southeastern China.

Typhoon Haima is developing into a very strong and dangerous typhoon.  Haima has a small eye at the center of circulation.  The eye is surrounded by a ring of very strong thunderstorms.  Rainbands are rotating around the core of the circulation.  Thunderstorms in the core of Typhoon Haima are generating upper level divergence which is pumping out mass in all directions.

Typhoon Haima is moving through an environment that is favorable for continued intensification.  It is moving over water where the Sea Surface Temperature is 30°C.  The upper level winds are weak and there is little vertical wind shear.  Typhoon Haima is likely to continue to intensify and it could reach super typhoon status.

A subtropical ridge is steering Typhoon Haima toward the west-northwest and that general motion is expected to continue for several more days.  On its anticipated track Typhoon Haima could be near the northern end of Luzon in about three days.  It could be a very powerful typhoon at that time.

Typhoon Champi Bringing Wind and Rain to Iwo To

A portion of the northern eyewall of Typhoon Champi is over Iwo To and it is bringing wind and rain to the island.  A weather station on Iwo To is reporting east-northeasterly winds at 47 m.p.h. (75 km/h) with gusts to 73 m.p.h. (118 km/h).  At 11:00 p.m. EDT on Wednesday the center of Typhoon Champi was located at latitude 23.8°N and longitude 141.6°E which put it about 75 miles (120 km) south of Iwo To.  Champi was moving toward the northeast at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 945 mb.

The inner core of Typhoon Champi became much more well organized during the past 12 hours and it now has a clear circular eye that is approximately 30 miles (48 km) across.  The eye is surrounded by a ring of strong convection which contains the strongest winds.  The core is also generating upper level divergence which is pumping out mass.

Typhoon Champi will be in a favorable environment for another 12 hours.  It is moving over water where the Sea Surface Temperature is near 28.5°C.  The upper level winds are light and there is not much upper level divergence.  Champi could intensify further on Thursday, but it will move into a less favorable environment when it moves farther north.  Once Champi gets north of latitude 27°N, it will move over cooler SSTs.  Typhoon Champi will start to encounter strong upper level westerly winds at about the same time.  The combination of cooler water and more vertical wind shear will steadily weaken Champi.

Typhoon Champi is moving northward around the western end of a subtropical ridge.  When it reaches the upper level westerly winds, those winds will accelerated Champi toward the east-northeast until it transforms into an extratropical cyclone over cooler waters.  On its anticipated track the center of Champi will pass southeast of Iwo To, but it will bring strong winds and rain to that island for another 12 hours or so.

Strong Typhoon Champi Intensifies South of Iwo To

Typhoon Champi intensified rapidly on Sunday and it reached the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  At 5:00 p.m. EDT on Sunday the center of Typhoon Champi was located at latitude 20.3°N and longitude 140.3°E which put it about 325 miles (525 km) south-southwest of Iwo To.  Champi was moving toward the north-northeast at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 145 m.p.h. (235 km/h) and there were wind gusts to 175 m.p.h. (280 km/h).  The minimum surface pressure was 924 mb.

The circulation of Typhoon Champi is very well organized.  It has a well defined eye and there could be a rainband wrapping around the center to create concentric eyewalls.  Multiple spiral bands are revolving around the center of circulation.  Winds to typhoon force extend out 40 miles (65 km) from the center.  Well developed upper level divergence is pumping out mass in all directions.

Typhoon Champi is moving over water where the Sea Surface Temperature is near 29°C.  The winds in the upper levels are relatively light and there is not much vertical wind shear.  Champi will remain in a favorable environment for another 24 to 48 hours.  Eyewall replacement cycles could cause fluctuations in intensity during that period.  When it moves north of latitude 25°N, Champi will encounter the upper level westerly winds in the middle latitudes which will cause significant vertical wind shear.  Champi will weaken as the wind shear increases.

Champi is moving slowly northward as it curves around the western end of a subtropical ridge.  It will continue to move northward for another day or two.  When it begins to be affected by the upper level westerly winds, Champi will accelerate toward the northeast.  On its anticipated track Typhoon Champi will approach Iwo To in 48 to 60 hours.  Champi will be a large, strong typhoon at that time.

Tropical Storm Champi Passing Through the Northern Marianas

Tropical Storm Champi is bringing gusty winds and heavy rain as it moves through the Northern Marianas.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Champi was centered near latitude 15.9°N and longitude 146.3°E which put it about 80 miles (135 km) east-northeast of Saipan.  Champi was moving toward the west at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 70 m.p.h. (115 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 980 mb.  A Tropical Storm Warning remains in effect for Rota, Tinian, Saipan, Alamagan, Pagan and Agrihan.  The weather station at the airport on Saipan was reporting southwesterly winds at 46 m.p.h. (74 km/h) with gusts to 78 m.p.h. (126 km/h).

Although an upper level ridge north of Champi continued to cause vertical wind shear over the tropical storm, it slowly intensified on Thursday.  More thunderstorms formed near the center of circulation and those storms are generating more upper level divergence.  The core of the circulation is consolidating and more spiral bands are forming outside the core.  Champi is on the threshold of becoming a typhoon.  It is moving over water where the Sea Surface Temperature is near 29°C.  Champi is likely to move into an area where the upper level winds are lighter during the weekend and it will continue to intensify during the next several days.

A subtropical ridge is steering Champi toward the west and that motion is expected to continue for the next 12 to 24 hours.  After that time Champi will reach the western end of the ridge and turn toward the north.  Champi could be a strong typhoon south of Iwo To in about three days.