Category Archives: Tropical Cyclones

Information about tropical cyclones

Tropical Storm Lekima Forms East of Luzon

Tropical Storm Lekima formed east of Luzon on Sunday.  More thunderstorms developed near the center of former Tropical Depression 10W and the Japan Meteorological Agency designated the system as Tropical Storm Lekima.  At 5:00 a.m. EDT on Sunday the center of Tropical Storm Lekima was located at latitude 16.8°N and longitude 131.3°E which put it about 725 miles (1170 km) south-southeast of Okinawa.  Lekima was moving toward the northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 996 mb.

The distribution of thunderstorms around Tropical Storm Lekima was asymmetrical.  Many of the stronger thunderstorms were occurring in bands west of the center of circulation.  There were fewer thunderstorms in the eastern half of the circulation.  Lekima was near the western end of an upper level ridge.  The ridge was producing easterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and the wind shear was contributing to the asymmetrical distribution of thunderstorms.

Tropical Storm Lekima will move through an environment favorable for intensification during the next few days.  Lekima will move over water where the Sea Surface Temperature is near 31°C.  It will move gradually into a region where the upper level winds are weaker and the vertical wind shear will diminish.  Tropical Storm Lekima will intensify and it could strengthen into a typhoon early next week.

Tropical Storm Lekima will move around the southwestern part of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Lekima toward the northwest.  On its anticipated track Tropical Storm Lekima could approach the southern Ryukyu Islands and Taiwan in about four days.  Lekima could be a typhoon by that time.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Francisco was speeding toward southwestern Japan.  At 5:00 a.m. EDT on Sunday the center of Tropical Storm Francisco was located at latitude 28.9°N and longitude 140.8°E which put it about 710 miles (1150 km) east-southeast of Kagoshima, Japan.  Francisco was moving toward the northwest at 19 m.p.h. (32 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 992 mb.

Tropical Storm Gil Forms Over Eastern North Pacific

Tropical Storm Gil formed over the Eastern North Pacific Ocean on Saturday.  A scatterometer onboard a satellite found winds to tropical storm force northeast of the center of former Tropical Depression Eight-E and the National Hurricane Center designated the system as Tropical Storm Gil.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Gil was located at latitude 15.0°N and longitude 122.4°W which put it about 980 miles (1580 km) west-southwest of the southern tip of Baja California.  Gil was moving toward the west-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to about 50 m.p.h. (80 km/h).  The minimum surface pressure was 1006 mb.

The circulation around Tropical Storm Gil was asymmetrical.  There was a distinct low level center of circulation which was visible on satellite imagery.  However, the stronger thunderstorms were occurring east of the center of circulation.  Bands in the western half of Gil consisted primarily of showers and lower clouds.  An upper level trough south of California was producing strong westerly winds which were blowing across the top of the circulation.  The winds were causing strong vertical wind shear and they were contributing to the asymmetrical distribution of thunderstorms.  Tropical storm force winds were occurring within 80 miles (130 km) of the center of Tropical Storm Gil only in the northeastern quadrant of of the circulation.

Tropical Storm Gil will move through an environment only marginally favorable for intensification.  Gil will move over water where the Sea Surface Temperature is near 27°C.  However, the upper level trough will continue to cause significant vertical wind shear.  The strong vertical wind shear will inhibit intensification of Tropical Storm Gil.  Gil could weaken to a tropical depression if the shear increases.

Tropical Storm Gil will move south of a subtropical ridge over the Eastern North Pacific Ocean.  The ridge will steer Gil in a westward direction during the next several days.  On its anticipated track, Tropical Storm Gil will move farther away from Mexico.

Elsewhere over the Central Pacific Ocean, strong vertical wind shear was weakening Tropical Storm Erick and Tropical Storm Flossie.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Erick was located at latitude 17.3°N and longitude 163.9°W which put it about 480 miles (770 km) southwest of Honolulu, Hawaii.  Erick was moving toward the west at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1005 mb.

At 5:00 p.m. EDT on Saturday the center of Tropical Storm Flossie was located at latitude 18.8°N and longitude 144.5°W which put it about 695 miles (1115 km) east of Hilo, Hawaii.  Flossie was moving toward the west-northwest at 13 m.p.h. (20 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 1003 mb.

Tropical Storm Wipha Drops Heavy Rain on Vietnam and China

Tropical Storm Wipha dropped heavy rain on parts of northeastern Vietnam and southern China on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Wipha was located at latitude 21.3°N and longitude 107.4°E which put it about 60 miles (95 km) northeast of Hai Phong, Vietnam.  Wipha was moving toward the west-southwest at 10 m.p.h. (16 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 990 mb.

The circulation around Tropical Storm Wipha exhibited much greater organization on Friday even though it was moving close to the coast of southern China.  There was a tighter inner core and more thunderstorms were occurring in the bands revolving around the core.  Storms near the core were generating upper level divergence which was pumping mass away from the tropical storm in all directions.  The appearance of Tropical Storm Wipha on satellite imagery was much more circular and symmetrical.  The strongest winds were occurring in the part of the circulation that was still over water.

Tropical Storm Wipha was being steering slowly toward the west-southwest by a subtropical ridge over China and the adjacent waters of the Western North Pacific Ocean.  The combination of greater organization and slow movement will allow Wipha to drop very heavy rainfall over coastal regions of southern China and northern Vietnam.  Prolonged heavy rain will very likely cause flash flooding in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Francisco was strengthening slowly east-southeast of Iwo To.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Francisco was located at latitude 23.2°N and longitude 149.4°E which put it about 545 miles (880 km) east-southeast of Iwo To.  Francisco 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 995 mb.

Weakening Tropical Storm Erick Passes South of Hawaii

A weakening Tropical Storm Erick was passing south of Hawaii on Friday.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Erick was located at latitude 16.8°N and longitude 157.4°W which put it about 310 miles (505 km) south of Honolulu, Hawaii.  Erick was moving toward the west-northwest at 14 m.p.h. (22 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 1000 mb.

An upper level trough northwest of the Hawaii Islands was producing strong southwesterly winds which were blowing across the top of Tropical Storm Erick.  Those winds were causing strong vertical wind shear, which was causing Erick to weaken quickly.  Most of the thunderstorms were occurring in bands northeast of the center of circulation.  Bands near the center and in other parts of Tropical Storm Erick consisted primarily of showers and lower clouds.  The stronger winds were occurring in the northern half of the circulation.  Winds to tropical storm force extended out about 100 miles (160 km) from the center of circulation.

A Flash Flood Watch was in effect for the Big Island of Hawaii through Saturday morning.  Counterclockwise flow around Tropical Storm Erick was producing southeasterly which were blowing up the slopes on the Big Island.  The enhanced rising will also increase rainfall on those slopes and flash floods could occur in some locations.

Elsewhere, Tropical Storm Flossie was showing signs of strengthening back into a hurricane.  An eye appeared to be forming at the center of Flossie.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Flossie was located at latitude 17.1°N and longitude 137.8°W which put it about 1145 miles (1845 km) east of HIlo, Hawaii.  Flossie was moving toward the west-northwest at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 993 mb.

Tropical Storm Francisco Forms Northeast of the Marianas

Tropical Storm Francisco formed northeast of the Marianas  on Thursday night.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Francisco was located at latitude 20.4°N and longitude 152.4°E which put it about 800 miles (1290 km) east-southeast of Iwo To.  Francisco was moving toward the northwest at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 998 mb.

A surface low pressure system developed southeast of an upper low north of the Marianas and the Japan Meteorological Agency designated the system as Tropical Storm Francisco.  The distribution of thunderstorms around Francisco was asymmetrical.  Stronger thunderstorms were occurring east of the center of circulation and in a band south of the center of Tropical Storm Francisco.  Bands in other parts of the circulation consisted primarily of showers and lower clouds.  The upper low was producing southwesterly winds which were causing moderate vertical wind shear.  The wind shear was the main factor responsible for asymmetrical distribution of thunderstorms.

Tropical Storm Francisco will move through an environment somewhat favorable for intensification during the next 24 hours.  Francisco will move over water where the Sea Surface Temperature is near 29°C.  The upper low north of the Marianas will continue to cause moderate vertical wind shear during the next day or so.  Tropical Storm Francisco could intensify slowly on Friday.  Francisco will move farther north of the upper low over the weekend.  When it gets farther away from the upper low, the wind shear will diminish and Tropical Storm Francisco could strengthen more quickly.

Tropical Storm Francisco will move southwest of a subtropical ridge over Western North Pacific Ocean.  The ridge will steer Francisco toward the northwest.  On its anticipated track Tropical Storm Francisco could be northeast of Iwo To in about 48 hours.  Francisco could approach southwestern Japan in about fours days.  It is forecast to be a typhoon by that time.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Wipha was moving slowly near the south coast of China.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Wipha was located at latitude 21.1°N and longitude 109.2°E which put it about 25 miles (40 km) south of Beihai, China.  Wipha was moving toward the southwest at 2 m.p.h. (3 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. (80 km/h).  The minimum surface pressure was 990 mb.

Tropical Storm Wipha Brings Wind and Rain to South China

Tropical Storm Wipha brought wind and rain to south China on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Wipha was located at latitude 20.5°N and longitude 110.6°E which put it about 50 miles (80 km) southeast of Leizhou, China.  Wipha was moving toward the west-northwest at 8 m.p.h. (13 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 990 mb.

The circulation around Tropical Storm Wipha contained a large rainband in the southern half of the tropical storm and another large rainband in the northern half of the circulation.  The rainband in the southern half of Wipha brought wind and rain to Hainan Island.  The rainband in the northern part of the tropical storm brought wind and rain to south China including Hong Kong.  Persistent heavy rain was creating the potential for flash floods in parts of southern China.

Tropical Storm Wipha was moving around the southwestern part of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Wipha toward the west-northwest during the next 24 to 36 hours.  On its anticipated track Tropical Storm Wipha will move close to the coast of south China and northeastern Vietnam.  Wipha will continue to bring gusty winds and drop locally heavy rain over those regions on Thursday.

Tropical Storm Wipha Forms South of Macau

Tropical Storm Wipha formed south of Macau late on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Wipha was located at latitude 18.8°N and longitude 112.6°E which put it about 175 miles (285 km) south of Macau.  Wipha was moving toward the northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 994 mb.

The circulation around Tropical Storm Wipha was large, but Wipha did not have a well formed inner core.  Winds to tropical storm force extended out about 200 miles (320 km) from the center of circulation.  However, there were no strong thunderstorms near the center.  Stronger thunderstorms were occurring in bands well to the south and east of the center of circulation.  Bands northwest of the center consisted primarily of showers and lower clouds.

The large lower level circulation of Tropical Storm Wipha was just to the southeast of an upper low over the northwestern part of the South China Sea.  The upper low was circulating some drier air over the northwestern part of Wipha.  It was also causing some vertical wind shear.  The drier air and wind shear were inhibiting the formation of thunderstorms in the northwestern part of Tropical Storm Wipha.

Tropical Storm Wipha will move through an environment somewhat favorable for intensification during the next 24 hours.  Wipha will move over water where the Sea Surface Temperature is near 30°C.  The upper low will continue to inhibit the strengthening of Tropical Storm Wipha.  If thunderstorms begin to develop near the center of Wipha, then the tropical storm could strengthen.

Tropical Storm Wipha will move around the southwestern part of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Wipha toward the northwest during the next 24 hours.  On its anticipated track the center of Tropical Storm Wipha will be near the northern part of Hainan Island and the south coast of China in 18 to 24 hours.  Wipha could move more toward the west when it reaches the Gulf of Tongking.  Although Tropical Storm Wipha will bring gusty winds to southern China and northern Vietnam, locally heavy rain and the potential for floods will be greater risks.

Erick Rapidly Intensifies Into Major Hurricane

Erick rapidly intensified into a major hurricane over the the Central Pacific Ocean during Monday night.  At 11:00 a.m. EDT on Tuesday the center of Hurricane Erick was located at latitude 13.4°N and longitude 142.8°W which put it about 920 miles (1485 km) east-southeast of Hilo, Hawaii.  Erick was moving toward the west at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 140 m.p.h. (225 km/h).  The minimum surface pressure was 966 mb.

The core of Hurricane Erick intensified rapidly during the overnight hours.  The eye became more circular and distinct on infrared satellite images.  The diameter of the eye was about 12 miles (19 km) on Tuesday morning.  Thunderstorms in the ring around the eye grew taller and the wind speed around the eye increased quickly.  Storms around the core of Erick generated strong upper level divergence which pumped mass away from the hurricane.  Multiple bands of showers and thunderstorms were revolving around the core of the circulation.

The circulation around Hurricane Erick was relatively small.  Winds to hurricane force were occurring within 25 miles (40 km) of the center of circulation.  Winds to tropical storm force extended out about 100 miles (160 km) of the center.  The Hurricane Intensity Index (HII) for Hurricane Erick was 20.6.  The Hurricane Size Index (HSI) was 8.2 and the Hurricane Wind Intensity Size Index (HWISI) was 28.8.

Hurricane Erick will remain in an environment favorable for intensification for about another 24 hours.  Erick will move over water where the Sea Surface Temperature is near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear during the next day or so.  Hurricane Erick will approach an upper level trough east of Hawaii on Wednesday.  The trough will produce stronger southwesterly winds which will cause the vertical wind shear to increase.  Hurricane Erick will start to weaken when the wind shear increases.

Hurricane Erick will move south of a subtropical high pressure system over the Eastern and Central North Pacific Ocean.  The high will steer Erick toward the west during the next several days.  On its anticipated track Hurricane Erick could be south of Hawaii on Thursday night.

Elsewhere, Tropical Storm Flossie was nearing hurricane strength over the Eastern North Pacific Ocean.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Flossie was located at latitude 12.2°N and longitude 120.5°W which put it about 1015 mile (1635 km) southwest of the southern tip of Baja California.  Flossie was moving toward the west at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 999 mb.

Hurricane Erik and Tropical Storm Flossie Strengthen

Hurricane Erick and Tropical Storm Flossie both moved westward and strengthened over the Eastern North Pacific Ocean on Monday.  At 11:00 p.m. EDT on Monday the center of Hurricane Erick was located at latitude 12.7°N and longitude 140.0°W which put it about 1110 miles (1790 km) east-southeast of Hilo, Hawaii.  Erick was moving west at 18 m.p.h. (30 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. (145 km/h).  The minimum surface pressure was 990 mb.

The circulation around Hurricane Erick exhibited greater organization on Monday.  A small eye developed at the center of circulation.  The eye was surround by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms,  Winds to hurricane force extended out about 20 miles (30 km) from the center of circulation.  Bands of showers and thunderstorms were revolving around the core of Hurricane Erick.  Storms near the core were generating upper level divergence which was pumping mass away from the hurricane.  Winds to tropical storm force extended out about 70 miles (110 km) from the center.

Hurricane Erick will move through an environment favorable for intensification during the next 48 hours.  Erick will move over water where the Sea Surface Temperature is near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Erick will intensify during the next two days and it could strengthen into a major hurricane.  Eventually, Erick will approach an upper level trough east of Hawaii and the vertical wind shear will increase.

Hurricane Erick will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high will steer Erick toward the west. On its anticipated track Hurricane Erick could be southeast of Hawaii on Thursday.

Elsewhere over the Eastern North Pacific Ocean, Tropical Storm Flossie was also intensifying.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Flossie was located at latitude 12.3°N and longitude 117.8°W which put it about 895 miles (1445 km) southwest of the southern tip of Baja California.  Flossie was moving toward the west at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 1001 mb.  Tropical Storm Flossie is also forecast to move westward and strengthen.

Tropical Storm Erick Forms Over Eastern North Pacific

Tropical Storm Erick formed over the Eastern North Pacific Ocean on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Erick was located at latitude 11.9°N and longitude 126.8°W which put it about 1955 miles (3145 km) east-southeast of Hilo, Hawaii.  Erick was moving toward the west at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1005 mb.

More thunderstorms developed near the center of a low pressure system over the Eastern North Pacific Ocean and the National Hurricane Center designated the system as Tropical Storm Erick.  The circulation around Erick was still organizing.  A small cluster of thunderstorms formed near the center of circulation and the strongest winds were occurring in that cluster.  Winds to tropical storm force extended out about 25 miles (40 km) from the center of circulation.  Bands of showers and thunderstorms were developing and the bands were beginning to revolve around the center of Tropical Storm Erick.  Storms near the center of circulation were starting to generate upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Erick will move through an environment favorable for intensification during the next 48 to 72 hours.  Erick will move over water where the Sea Surface Temperature is near 27.5°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Erick will strengthen and it could become a hurricane within 48 hours.  Erick could intensify more rapidly if an eye and eyewall form.

Tropical Storm Erick will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The subtropical high will steer Erick toward the west-northwest during the next few days.  On its anticipated track Tropical Storm Erick could be southeast of Hawaii in four or five days.