Category Archives: Tropical Cyclones

Information about tropical cyclones

Andres Weakens to a Tropical Depression

Former Tropical Storm Andres weakened to a tropical depression on Monday afternoon. At 5:00 p.m. EDT on Monday the center of Tropical Depression Andres was located at latitude 16.0°N and longitude 109.8°W which put it about 475 miles (765 km) south of the southern tip of Baja California. Andres was moving toward the north-northwest at 7 m.p.h. (11 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 1006 mb.

Strong vertical wind shear caused former Tropical Storm Andres to weaken to a tropical depression on Monday afternoon. An upper level trough northwest of Baja California was producing strong southwesterly winds which were blowing across the top of Tropical Depression Andres. Those winds were causing strong vertical wind shear and they were blowing the tops off of thunderstorms that tried to form. A few thunderstorms developed east of the center of Andres earlier on Monday, but the strong upper level winds blew the tops off of those storms. The circulation around Tropical Depression Andres consisted primarily of showers and lower clouds on Monday afternoon.

Tropical Depression Andres will move through an environment unfavorable for intensification during the next several days. Andres will move over water where the Sea Surface Temperatures will be near 26°C. However, the upper level trough northwest of Baja California will continue to produce strong upper level winds over Tropical Depression Andres. The strong upper level winds will blow the tops off any thunderstorms that begin to form and the circulation around Andres will gradually weaken.

Since the circulation around Tropical Depression Andres exists primarily in the lower levels, it will be steered by the wind closer to the surface. A large surface high pressure system over the Eastern North Pacific Ocean will steer Andres toward the west during the next several days. On its anticipated track Tropical Depression Andres will dissipate southwest of Baja California later this week.

TD 01E Strengthens to Tropical Storm Andres

Former Tropical Depression One-E strengthened to Tropical Storm Andres southwest of Mexico on Sunday morning. At 11:00 a.m. EDT on Sunday the center of Tropical Storm Andres was located at latitude 14.1°N and longitude 107.9°W which put it about 620 miles (1000 km) south-southeast of the southern tip of Baja California. Andres 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 1005 mb.

The circulation around former Tropical Depression One-E strengthened on Sunday morning and the National Hurricane Center designated the system as Tropical Storm Andres. The circulation around Andres was exhibiting more organization. Storms near the center of the circulation generated upper level divergence that pumped mass away from the tropical storm. Bands of showers and thunderstorms were revolving around the center of Andres. The strongest rainbands were in the eastern half of the circulation. Winds to tropical storm force extended out 70 miles (110 km) in the northeastern quadrant of Tropical Storm Andres. The winds in the other parts of the circulation were blowing at less than tropical storm force.

Tropical Storm Andres will move through an environment favorable for intensification during the next 24 hours. Andres will move over water where the Sea Surface Temperatures will be near 28°C. It will move under the center of an upper level ridge southwest of Mexico. The winds are weak near the center of the ridge and there will be little vertical wind shear. Tropical Storm Andres could strengthen during the next 24 hours. An upper level trough over the Eastern North Pacific Ocean will approach Andres from the west on Monday. The trough will produce southwesterly winds which will blow toward the top of the tropical storm. Those winds will cause the vertical wind shear to increase. More wind shear will cause Tropical Storm Andres to weaken early next week.

Tropical Storm Andres will move around the southwestern part of a subtropical high pressure system over the Gulf of Mexico and Mexico. The high will steer Andres toward the northwest on Sunday. Tropical Storm Andres will move southeast of a large high pressure system over the Eastern North Pacific Ocean during the early part of next week. That high pressure system will steer Andres toward the west. On its anticipated track Tropical Storm Andres will remain south of Baja California.

Tropical Depression One-E Forms Southwest of Mexico

Tropical Depression One-E formed southwest of Mexico on Sunday morning. At 5:00 a.m. EDT on Sunday the center of Tropical Depression One-E was located at latitude 13.8°N and longitude 107.7°W which put it about 645 miles (1035 km) south-southeast of the southern tip of Baja California. The depression was moving toward the northwest at 5 m.p.h. (8 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 1006 mb.

More thunderstorms developed near the center of a low pressure system formerly called Invest 90E on Sunday morning and the National Hurricane Center designated the system as Tropical Depression One-E. The circulation around the depression was exhibiting more organization. Storms near the center of the depression began to generate more upper level divergence which pumped mass away from it. Bands of showers and thunderstorms were revolving around the center.

Tropical Depression One-E will move through an environment favorable for develop of a tropical cyclone during the next 24 hours. It will move over water where the Sea Surface Temperatures will be near 29°C. The tropical depression will move under the center of an upper level ridge southwest of Mexico. The winds are weak near the center of the ridge and there will be little vertical wind shear. Tropical Depression One-E is likely to strengthen to a tropical storm during the next 24 hours. An upper level trough over the Eastern North Pacific Ocean will approach the depression from the west on Monday. The trough will produce southwesterly winds which will blow toward the top of the circulation. Those winds will cause the vertical wind shear to increase. More wind shear will cause the depression to weaken early next week.

Tropical Depression One-E will move around the southwestern part of a subtropical high pressure system over the Gulf of Mexico and Mexico. The high will steer the tropical depression toward the northwest on Sunday. Tropical Depression One-E will move southeast of a large high pressure system over the Eastern North Pacific Ocean during the early part of next week. That high pressure system will steer the tropical depression toward the west. On its anticipated track Tropical Depression One-E will remain south of Baja California.

Tropical Development Possible Southwest of Mexico

Development of a tropical cyclone southwest of Mexico is possible during the next few days. At 2:00 p.m. EDT on Friday the center of Invest 90E was located at latitude 11.2°N and longitude 102.5°W which put it about 415 miles (670 km) south-southwest of Acapulco, Mexico. The Invest was moving toward the west at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h). The minimum surface pressure was 1008 mb.

An area of low pressure, currently designated as Invest 90E, exhibited more organization on Friday afternoon. The National Hurricane Center (NHC) issued a Special Tropical Weather Outlook for the low pressure system. NHC indicated that there was a 40% probability that the system would develop into a tropical depression or a tropical storm during the next 48 hours and a 60% chance that development would occur during the next five days.

More thunderstorms developed near the center of Invest 90E. Bands of showers and thunderstorms also developed and the bands began to revolve around the center of the low pressure system. Storms near the center began to generate upper level divergence that pumped mass away from the system.

Invest 90E will move through an environment favorable for develop of a tropical cyclone during the next 36 hours. It will move over water where the Sea Surface Temperatures will be near 29°C. The low pressure system will move under the center of an upper level ridge southwest of Mexico. The winds are weak near the center of the ridge and there will be little vertical wind shear. Invest 90E is likely to develop into a tropical depression and it could quickly intensify into a tropical storm.

Invest 90E will move southeast of a large high pressure system over the Eastern North Pacific Ocean. The high pressure system will steer the Invest slowly toward the west-northwest. On its anticipated track the low pressure system will remain southwest of Mexico during the weekend.

Tropical Cyclone Jobo Moves Toward Tanzania

Tropical Cyclone Jobo moved toward Tanzania on Thursday. At 11:00 p.m. EDT on Thursday the center of Tropical Cyclone Jobo was located at latitude 9.1°S and longitude 43.6°E which put it about 335 miles (535 km) east-southeast of Dar es Salaam, Tanzania. Jobo was moving toward the west-northwest at 9 m.p.h. (15 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 992 mb.

The intensity and organization of Tropical Cyclone Jobo fluctuated during the past 48 hours as the strength of the upper level winds changed. At times Jobo intensified to the equivalent of a strong tropical storm when the upper levels winds diminished. Whenever the upper level winds were stronger, vertical wind shear caused the circulation to weaken. Tropical Cyclone Jobo was intensifying again on Thursday night. The inner end of a rainband wrapped around the southern and western sides of the center of circulation. Thunderstorms near the center generated more upper level divergence that pumped mass away from the tropical cyclone. The circulation of Tropical Cyclone Jobo was small, which was why vertical wind shear had such a big effect on the tropical cyclone. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation.

Tropical Cyclone Jobo will move through an environment favorable for intensification during the next 36 hours. Jobo will move over water where the Sea Surface Temperatures will be near 29°C. Jobo will move under the middle of an upper level ridge over southern Africa and the Southwest Indian Ocean. The winds are weaker near the middle of the ridge and there will be less vertical wind shear. Tropical Cyclone Jobo could strengthen during the next 36 hours, but any increase in the wind shear could cause the small circulation to weaken again.

Tropical Cyclone Jobo will move around the northern side of a subtropical high pressure system over southern Africa. The high will steer Jobo toward the west-northwest during the next several days. On its anticipated track Tropical Cyclone Jobo could approach the coast of Tanzania in 36 hours.

Typhoon Surigae Moves away from the Philippines

Typhoon Surigae started to move away from the Philippines on Wednesday. At 5:00 p.m. EDT on Wednesday the center of Typhoon Surigae was located at latitude 19.6°N and longitude 124.9°E which put it about 240 miles (385 km) east-northeast of Aparri, Philippines. Surigae was moving toward the north at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h). The minimum surface pressure was 952 mb.

Typhoon Surigae weakened slowly on Wednesday as it started to move farther away from the Philippines. A large circular eye with a diameter of 70 miles (110 km) was present at the center of Surigae. The eye was surrounded by a ring of strong thunderstorms and the stronger winds were occurring in that ring of storms. Several bands of showers and thunderstorms were revolving around the core of Typhoon Surigae. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

Typhoon Surigae still had a large circulation on Wednesday. Winds to typhoon force extended out 60 miles (95 km) from the center of Surigae. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Surigae was 22.1. The Hurricane Size Index (HSI) was 22.1 and the Hurricane Wind Intensity Size Index (HWISI) was 44.2. Surigae was still the equivalent of a major hurricane.

Typhoon Surigae will move into an environment that will become less favorable for a strong typhoon during the next several days. Surigae will move over cooler water northeast of the Philippines where the Sea Surface Temperatures is near 26°C. In addition, an upper level trough over China will move toward Typhoon Surigae. The trough will produce westerly winds which will blow toward the top of the typhoon. Those winds will cause the vertical wind shear to increase. The combination of cooler water and more wind shear will cause Typhoon Surigae to weaken during the next 48 hours.

The upper level trough will steer Typhoon Surigae toward the east-northeast during the next several days. On its anticipated track Surigae will move away from the Philippines and it will stay southeast of Taiwan and the Ryukyu Islands. Surigae could approach Iwo To by the end of the weekend.

Tropical Cyclone Jobo Forms North of Madagascar

Tropical Cyclone Jobo formed just to the north of Madagascar on Tuesday afternoon. At 5:00 p.m. EDT on Tuesday the center of Tropical Cyclone Jobo was located at latitude 10.3°S and longitude 49.8°E which put it about 100 miles (160 km) north of Ansiranana, Madagascar. Jobo was moving toward the west at 13 m.p.h. (20 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.

The circulation around a low pressure system north of Madagascar strengthened on Tuesday afternoon and Meteo France la Reunion designated the system as Tropical Cyclone Jobo. The distribution of thunderstorms around Tropical Cyclone Jobo was asymmetrical. Many of the stronger thunderstorms were occurring in bands on the western side of Jobo. Bands on the eastern side of the circulation consisted primarily of showers and lower clouds. The inner end of a rainband was wrapping around the western side of the center of circulation. Storms near the center started to generate upper level divergence that pumped mass away to the north and west of the tropical cyclone. Winds to tropical storm force extended out 85 miles (135 km) from the center of circulation.

Tropical Cyclone Jobo will move through an environment favorable for intensification during the next 36 hours. Jobo will move over water where the Sea Surface Temperatures will be near 29°C. It will move near the northern part of a small upper level ridge. The ridge will produce southeasterly winds which will blow toward the top of the tropical cyclone. Those winds will cause some vertical wind shear. The shear will inhibit intensification, but the wind shear will not be large enough to prevent Tropical Cyclone Jobo from strengthening. Some numerical models are forecasting that Jobo could intensify into the equivalent of a hurricane/typhoon later this week.

Tropical Cyclone Jobo will move north of a surface high pressure system over the Southwest Indian Ocean. The high will steer Jobo slowly toward the west during the next several days. On its anticipated track Tropical Cyclone Jobo will remain north of Madagascar. The steering currents could weaken later this week and Jobo could stall northwest of Madagascar.

Typhoon Surigae Stalls East of Luzon

Typhoon Surigae stalled east of Luzon on Monday. At 11:00 p.m. EDT on Monday the center of Typhoon Surigae was located at latitude 15.6°N and longitude 126.1°E which put it about 310 miles (500 km) east of Baler, Philippines. Surigae was moving toward the north-northwest at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h). The minimum surface pressure was 944 mb.

Typhoon Surigae completed an eyewall replacement cycle on Monday. The inner eyewall weakened to a swirl of low clouds. There was a large circular eye at the center of Surigae. The eye had a diameter of 60 miles (95 km). The large eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Surigae. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

The eyewall replacement cycle left Typhoon Surigae with a symmetrical circulation. Winds to typhoon force extended out 65 miles (105 km) from the center of Surigae. Winds to tropical storm force extended out 180 miles (290 km) from the center. The Hurricane Intensity Index (HII) for Typhoon Surigae was 25.1. The Hurricane Size Index (HSI) was 23.9 and the Hurricane Wind Intensity Size Index (HWISI) was 49.0.

Typhoon Surigae will move through an environment capable of supporting a strong typhoon during the next 24 hours. Surigae will be over water where the Sea Surface Temperatures will be near 29°C. It will move under the western part of an upper level ridge over the Western North Pacific Ocean. The upper level winds are weak near the end of the ridge and there will be little vertical wind shear. Typhoon Surigae will be moving slowly and it could mix cooler water to the surface. The cooler water could cause Surigae to weaken gradually.

Typhoon Surigae will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next 36 hours. The high will steer Surigae toward the north-northwest during the next 36 hours. After that time Typhoon Surigae will approach the westerly winds in the middle latitudes. Those winds will turn Surigae toward the east. On its anticipated track, the core Typhoon Surigae with the strongest winds will remain east of Luzon.

Typhoon Surigae Spins East of the Philippines

Typhoon Surigae spun east of the Philippines on Sunday. At 5:00 p.m. EDT on Sunday the center of Typhoon Surigae was located at latitude 14.2°N and longitude 126.4°E which put it about 260 miles (420 km) east of Daet, Philippines. Surigae was moving toward the northwest at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (275 km/h). The minimum surface pressure was 934 mb.

An eyewall replacement cycle was underway in the core of Typhoon Surigae and the typhoon was weakening. The inner part of a rainband wrapped around the original eye and eyewall and a much larger outer eyewall formed. The low level winds converged into the outer eyewall and the inner eyewall weakened. The fastest wind speeds were in the inner eyewall. So, the maximum wind speed decreased when the inner eyewall weakened. There were still remnants of the original inner eyewall inside the outer eyewall, but the strongest wind speeds were occurring in the outer eyewall.

Typhoon Surigae was still large and powerful. Winds to typhoon force extended out 60 miles (95 km) from the center of Surigae. Winds to tropical storm force extended out 195 miles (315 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Surigae was 28.3. The Hurricane Size Index (HSI) was 16.9 and the Hurricane Wind Intensity Size Index (HWISI) was 45.2.

Typhoon Surigae will move through an environment capable of supporting a powerful typhoon during the next 24 hours. Surigae will be over water where the Sea Surface Temperatures will be near 29°C. It will move under the western part of an upper level ridge over the Western North Pacific Ocean. The ridge will produce southerly winds which will blow toward the top of the circulation. However, the winds at lower levels in the atmosphere will also blow from the south and there will be little vertical wind shear. Typhoon Surigae will likely weaken gradually as the eyewall replacement cycle is completed.

Typhoon Surigae will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next 48 hours. The high will steer Surigae toward the north-northwest during the next 48 hours. After that time Typhoon Surigae will approach the westerly winds in the middle latitudes. Those winds will turn Surigae toward the northeast. On its anticipated track, the core Typhoon Surigae with the strongest winds will remain east of Luzon.

Typhoon Surigae Rapidly Intensifies to Equivalent of Cat. 5 Hurricane

Typhoon Surigae rapidly intensified to the equivalent of a Category 5 hurricane on the Saffir-Simspson Scale on Saturday. At 11:00 a.m. EDT on Saturday the center of Typhoon Surigae was located at latitude 12.3°N and longitude 128.8°E which put it about 275 miles (445 km) east-southeast of Laoang, Philippines. Surigae was moving toward the northwest at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 180 m.p.h. (290 km/h) and there were wind gusts to 215 m.p.h. (345 km/h). The minimum surface pressure was 900 mb.

Typhoon Surigae continued to intensify rapidly on Saturday. There was a circular eye with a diameter of 20 miles (32 km) at the center of Surigae. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Surigae. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the typhoon in all directions.

Typhoon Surigae was a large and powerful typhoon. Winds to typhoon force extended out 65 miles (105 km) from the center of Surigae. Winds to tropical storm force extended out 215 miles (345 km) from the center. The Hurricane Intensity Index (HII) for Typhoon Surigae was 42.2. The Hurricane Size Index (HSI) was 23.7 and the Hurricane Wind Intensity Size Index (HWISI) was 65.9.

Typhoon Surigae will move through an environment capable of supporting a powerful typhoon during the next 24 hours. Surigae will be over water where the Sea Surface Temperatures will be near 30°C. It will move under the western part of an upper level ridge over the Western North Pacific Ocean. The ridge will produce southeasterly winds which will blow toward the top of the circulation. However, the winds at lower levels in the atmosphere will also blow from the southeast and there will be little vertical wind shear. Typhoon Surigae may have attained its maximum intensity even though it will move through a very favorable environment. If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Surigae to weaken.

Typhoon Surigae will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next several days. The high will steer Surigae toward the north-northwest during the next 24 hours. After that time Typhoon Surigae will move more toward the north. On its anticipated track the core Typhoon Surigae with the strongest winds is forecast to pass east of the Philippines.