Category Archives: Tropical Cyclones

Information about tropical cyclones

Tropical Storm Mario Forms Near Zihuatanejo

Tropical Storm Mario formed over the Eastern North Pacific Ocean near Zihuatanejo, Mexico on Friday morning.  The government of Mexico issued a Tropical Storm Watch for a portion of the coast.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Mario was located at latitude 17.2°N and longitude 101.9°W which put the center about 40 miles (65 km) south-southwest of Zihuatanejo, Mexico.  Mario was moving toward the west-northwest at 14 m.p.h. (22 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 1006 mb.

A Tropical Storm Watch is in effect for the portion of the coast from Lazaro Cardenas to Punta San Telmo, Mexico.

A low pressure system over the Eastern North Pacific Ocean near Zijuatanejo strengthened on Friday morning and the U.S. National Hurricane Center designated the system as Tropical Storm Mario.

The circulation around Tropical Storm Mario exhibited more organization on Friday morning.  More thunderstorms developed near the center of Mario’s circulation.  Thunderstorms were also occurring in short bands that were revolving around the center of Tropical Storm Mario.  Storms near the center of Mario generated upper level divergence that pumped mass away from the tropical storm.

The circulation around Tropical Storm Mario was very small.  Winds to tropical storm force extended out 25 miles (40 km) in the northwestern quadrant of Mario’s circulation.  The winds in the other parts of Tropical Storm Mario were blowing at less than tropical storm force.

Tropical Storm Mario will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  Mario will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southern part of upper level ridge over Mexico.  The upper level ridge will produce northeasterly winds that will blow toward the top of Mario’s circulation.  Those winds will cause moderate vertical wind shear.  The circulation around Tropical Storm Mario could also pull drier air over Mexico in the tropical storm.  The moderate vertical wind shear and drier air will inhibit intensification.  Tropical Storm Mario could intensify during the next 24 hours if the center remains over the ocean.

Tropical Storm Mario will move around the around the southwestern part of a high pressure system over Mexico.  The high pressure system will steer Mario toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Mario will move near the coast of Michoacan.

Tropical Storm Mario will bring gusty winds and locally heavy rain to coastal parts of Michoacan.  Heavy rain could cause flash floods in some locations.

Kiko Weakens to a Tropical Storm

Former Hurricane Kiko weakened to a tropical storm over the Central Pacific Ocean northeast of Hawaii on Monday night.  At 5:00 a.m. EDT on Tuesday the center of Tropical Storm Kiko was located at latitude 21.9°N and longitude 152.1°W which put the center about 245 miles (395 km) northeast of Hilo Hawaii.  Kiko was moving toward the west-northwest at 14 m.p.h. (22 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 1004 mb.

Former Hurricane Kiko weakened to a tropical storm over the Central Pacific Ocean northeast of Hawaii during Monday night.  An upper level low that is north of Hawaii produced strong southwesterly winds that blew across the top of Kiko’s circulation.  Those winds caused strong vertical wind shear.  The strong vertical wind shear caused Kiko to weaken to a tropical storm.

The strong upper level winds blew the tops off of most of the thunderstorms in Tropical Storm Kiko.  A few thunderstorms remained in the far northeastern periphery of Kiko’s circulation.  Most of the bands revolving around the center of Tropical Storm Kiko consisted of showers and lower clouds.  Since there were no thunderstorms near the center of Kiko to pump mass away, the surface pressure increased rapidly.

The size of the circulation around Tropical Storm Kiko expanded a little as Kiko weakened.  Winds to tropical storm force extended out 125 miles (200 km) from the center of Kiko’s circulation.

Tropical Storm Kiko will move through an environment unfavorable for intensification during the next 24 hours.  Kiko will move over water where the Sea Surface Temperatures are near 27°C.  However, the upper low north of Hawaii will continue to cause strong vertical wind shear.  The strong vertical wind shear will cause Tropical Storm Kiko to continue to weaken.

Tropical Storm Kiko will move around the southern side of a high pressure system over the Central Pacific Ocean.  The high pressure system will steer Kiko toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Kiko will pass north of Hawaii.

 

Typhoon Tapah Brings Wind and Rain to Southern China

Typhoon Tapah brought wind and rain to southern China on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Typhoon Tapah was located at latitude 22.2°N and longitude 112.2°E which put the center about 75 miles (120 km) west of Macau.  Tapah was moving toward the north-northwest at 13 m.p.h. (21 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 984 mb.

Former Tropical Storm Tapah strengthened to a typhoon just before it made landfall on the coast of southern China on Sunday night.  The center of Typhoon Tapah made landfall about 75 miles (120 km) west of Macau.

The strongest winds in Typhoon Tapah were occurring in the southern part of Tapah’s circulation which was still over the South China Sea.  Winds to typhoon force extended out 40 miles (65 km) in the southern half of Typhoon Tapan.  Winds to tropical storm force extended out 120 miles (195 km) from the center of Tapah’s circulation.

Typhoon Tapah will move around the southwestern side of a high pressure system over China.  The high pressure system will steer Tapah toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Tapah will move inland over Guangdong and Guangxi.

Typhoon Tapah will bring strong winds and heavy rain to southwestern Guangdong.  Heavy rain is likely to cause floods in some locations.  Typhoon Tapah will weaken steadily as it move inland over southern China.  Tapah will also bring gusty winds and locally heavy rain to parts of Guangxi.

 

Hurricane Kiko Weakens

Hurricane Kiko weakened east of Hawaii on Sunday.  At 5:00 p.m. EDT on Sunday the center of Hurricane Kiko was located at latitude 18.1°N and longitude 145.5°W which put the center about 635 miles (1025 km) east of Hilo Hawaii. Kiko was moving toward the west-northwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 974 mb.

Hurricane Kiko weakened east of Hawaii on Sunday as it moved over water where the Sea Surface Temperature was near 26°C.  A circular eye was still present at the center of Kiko’s circulation, but low clouds were starting to appear inside the eye.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Storms near the center of Kiko generated upper level divergence that pumped mass away from the hurricane.  However, more mass was converging in the lower levels of the atmosphere than was being pumped away in the upper levels.  So, the surface pressure was increasing.

The circulation around Hurricane Kiko was small.  Winds to hurricane force extended out 30 miles (50 km) from the center of Kiko’s circulation.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Hurricane Kiko.

The Hurricane Intensity Index (HII) for Hurricane Zeta was 19.2.  The Hurricane Size Index (HSI) was 9.1 and the Hurricane Wind Intensity Size Index (HWISI) was 28.3. Hurricane Kiko was similar in size and intensity to Hurricane Zeta when Zeta hit Louisiana in 2020.

Hurricane Kiko will move through an environment that will become even more unfavorable for intensification during the next 24 hours.  Kiko will move over water where the Sea Surface Temperatures are near 26°C.  The water just to the north of Kiko’s forecast track is even colder. It will move under the southeastern part of an upper level low that is north of Hawaii.  The upper level low will produce southwesterly winds that will blow toward the top of Kiko’s circulation.  Those winds will cause the vertical wind shear to increase.  The combination of marginal Sea Surface Temperatures and more vertical wind shear will cause Hurricane Kiko to continue to weaken during the next 24 hours.

Hurricane Kiko will move around the southwestern part of a high pressure system over the Eastern North Pacific Ocean.  The high pressure system will steer Kiko toward the west-northwest during the next 24 hours.  On its anticipated track, Hurricane Kiko will be northeast of Hawaii on Monday night.

Tropical Storm Tapah Nears Southern China

Tropical Storm Tapah was nearing the coast of southern China on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Tapah was located at latitude 20.4°N and longitude 113.4°E which put the center about 75 miles (120 km) south of Macau.  Tapah was moving toward the north-northwest at 8 m.p.h. (13 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 991 mb.

Tropical Storm Tapah was strengthening as it neared the coast of southern China on Sunday.  The inner end of a rainband wrapped around the eastern side of the center of Tapah’s circulation.  An eye appeared to be forming at the center of Tropical Storm Tapah.  Bands of showers and thunderstorms were revolving around the center of Tapah’s circulation.  Storms near the center of Tapah generated upper level divergence that pumped mass away to the southwest of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Tapah became more symmetrical on Sunday.  Winds to tropical storm force extended out 120 miles (195 km) from the center of Tapah’s circulation.

Tropical Storm Tapah will move through an environment favorable for intensification during the next 12 hours.  Tapah will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge that is over China.  The upper level ridge will produce northeasterly winds that will blow toward the top of Tapah’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  Tropical Storm Tapah will intensify during the next 12 hours.  Tapah could strengthen to a typhoon before it reaches the coast of southern China.

Tropical Storm Tapah will move around the southwestern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Tapah toward the northwest during the next 12 hours.  On its anticipated track, Tropical Storm Tapah will make landfall on the coast of southern China west of Macau in 12 hours.

Tropical Storm Tapah could intensify to a typhoon before it makes landfall on the coast of southern China.  Tapah will bring strong winds and heavy rain to southwestern Guangdong.  Heavy rain is likely to cause floods in some locations.

Hurricane Kiko Crosses to Central Pacific

Hurricane Kiko officially crossed from the Eastern North Pacific to the Central Pacific Ocean on Saturday.  At 5:00 p.m. EDT on Saturday the center of Hurricane Kiko was located at latitude 16.1°N and longitude 141.4°W which put the center about 935 miles (1500 km) east-southeast of Hilo Hawaii.  Kiko was moving toward the west-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (220 km/h).  The minimum surface pressure was 954 mb.

Hurricane Kiko was gradually weakening as it crossed into the Central Pacific on Saturday.  Even though Kiko was weakening, it remained a well organized major hurricane.  A circular eye with a diameter of 15 miles (24 km) was still present at the center of Kiko’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Kiko.  Storms near the center generated upper level divergence that pumped mass away from the hurricane.  The removal of mass in the upper atmosphere was less than the inflow of mass in the lower levels.  So, the surface pressure was increasing gradually.

The circulation around Hurricane Kiko was small.  Winds to hurricane force extended out 25 miles (40 km) from the center of Kiko’s circulation.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Hurricane Kiko.

The Hurricane Intensity Index (HII) for Hurricane Zeta was 22.1.  The Hurricane Size Index (HSI) was 8.0 and the Hurricane Wind Intensity Size Index (HWISI) was 30.1.  Hurricane Kiko was similar in size to Hurricane Zeta when Zeta hit Louisiana in 2020.  Kiko was stronger than Zeta was.

Hurricane Kiko will move through an environment that will be unfavorable for intensification during the next 24 hours.  Kiko will move over water where the Sea Surface Temperatures are near 26°C.  The water just to the north of Kiko’s forecast track is even colder.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Kiko will move into a region of drier air.  The combination of marginal Sea Surface Temperatures and drier air will cause Hurricane Kiko to continue to weaken gradually during the next 24 hours.

Hurricane Kiko will move around the southwestern part of a high pressure system over the Eastern North Pacific Ocean.  The high pressure system will steer Kiko toward the west-northwest during the next 24 hours.  On its anticipated track, Hurricane Kiko be east of Hawaii on Sunday night.

Tropical Storm Tapah Forms over South China Sea

Tropical Storm Tapah formed over the South China Sea on Saturday.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Tapah was located at latitude 18.6°N and longitude 115.2°E which put the center about 280 miles (455 km) south-southeast of Hong Kong.  Tapah was moving toward the west-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 999 mb.

A low pressure system over the South China Sea strengthened on Saturday and the Japan Meteorological Agency designated the system as Tropical Storm Tapah.

The distribution of thunderstorms in Tropical Storm Tapan was asymmetrical.  Thunderstorms were occurring in bands in the southern side of Tapah’s circulation.  Bands in the northern side of Tropical Storm Tapah consisted primarily of showers and lower clouds.  Storms near the center of Tapah generated upper level divergence that pumped mass away to the west of the tropical storm.

The circulation around Tropical Storm Tapah was large,  Winds to tropical storm force extended out 145 miles (235 km) from the center of Tapah’s circulation.

Tropical Storm Tapah will move through an environment favorable for intensification during the next 24 hours.  Tapah will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge that is over China.  The upper level ridge will produce northeasterly winds that will blow toward the top of Tapah’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  Tropical Storm Tapah will intensify during the next 24 hours.

Tropical Storm Tapah will move around the southwestern side of a high pressure system over the Western North Pacific Ocean.   The high pressure system will steer Tapah toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Tapah will approach the coast of southern China in 36 hours.

Hurricane Kiko Churns Closer to Hawaii

Hurricane Kiko slowly churned closer to Hawaii on Friday.  At 5:00 p.m. EDT on Friday the center of Hurricane Kiko was located at latitude 14.5°N and longitude 137.8°W which put the center about 1195 miles (1925 km) east-southeast of Hilo Hawaii.  Kiko was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 951 mb.

After weakening briefly earlier on Friday Hurricane Kiko strengthened back to Category 4 on the Saffir-Simpson Scale.  A circular eye with a diameter of 15 miles (24 km) was visible at the center of Kiko’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Kiko.  Storms near the center of Kiko generated upper level divergence that pumped mass away from the hurricane.

The circulation around Hurricane Kiko was small.  Winds to hurricane force extended out 25 miles (40 km) from the center of Kiko’s circulation.  Winds to tropical storm force extended out 70 miles (110 km) from the center of Hurricane Kiko.

The Hurricane Intensity Index (HII) for Hurricane Kiko was 25.1.  The Hurricane Size Index (HSI) was 8.5 and the Hurricane Wind Intensity Size Index (HWISI) was 33.6.  Hurricane Kiko was similar in intensity to Hurricane Harvey when Harvey hit Texas in 2017.  Kiko was not as large as Harvey was.

Hurricane Kiko will move through an environment favorable for intensification during the next 24 hours.  Kiko will move over water where the Sea Surface Temperatures are near 27°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Hurricane Kiko is likely to intensify during the next 24 hours unless an eyewall replacement cycle occurs.

Hurricane Kiko will move around the southwestern part of a high pressure system over the Eastern North Pacific Ocean.  The high pressure system will steer Kiko toward the west-northwest during the next 24 hours.  On its anticipated track, Hurricane Kiko will continue to move closer to Hawaii.

 

Tropical Storm Peipah Brings Wind and Rain to Japan

Tropical Storm Peipah brought wind and rain to parts of Japan on Thursday.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Peipah was located at latitude 32.8°N and longitude 132.8°E which put the center about 60 miles (95 km) southwest of Kochi, Japan.  Peipah was moving toward the northeast at 16 m.p.h. (26 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 997 mb.

The circulation around Tropical Storm Peipah exhibited more organization on Thursday.  More thunderstorms formed near the center of Peipah’s circulation.  Thunderstorms were also occurring in bands in the eastern and northern parts of Tropical Storm Peipah.  Bands in the western and southern parts of Peipah’s circulation still consisted primarily of showers and lower clouds.  Storms near the center of Peipah generated upper level divergence that pumped mass away to the northeast of the tropical storm.

In spite of the improved organization the distribution of wind speeds in Tropical Storm Peipah continued to be asymmetrical.  Winds to tropical storm force extended out 125 miles (200 km) in the southeastern quadrant of Peipah’s circulation.  The winds in the other parts of Tropical Storm Peipah were blowing at less than tropical storm force.

Tropical Storm Peipah will move through an environment somewhat favorable for intensification during the next 24 hours.  Peipah will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level trough that is northwest of Japan.  The upper level trough will produce westerly winds that will blow toward the top of Peipah’s circulation.  Those winds will cause moderate vertical wind shear. The vertical wind shear will inhibit intensification but the wind shear may not be enough to prevent intensification.  The center of Peipah will pass over southern Shikoku during the next few hours.  Tropical Storm Peipah could intensify a little during the next 24 hours when the center of circulation is over water.

The upper level trough that is northwest of Japan will steer Tropical Storm Peipah toward the east-northeast during the next 24 hours.  On its anticipated track, the center of Peipah’s circulation will move over southern Shikoku during the next few hours.  The center of Peipah will be south of Kyoto in 12 hours.  Tropical Storm Peipah could be near Tokyo in 24 hours.

Tropical Storm Peipah will bring gusty winds and locally heavy rain to parts of Shikoku and Honshu.  Heavy rain could cause flash floods in some locations.

Lorena Weakens to a Tropical Storm

Former Hurricane Lorena weakened to a tropical storm over the Eastern North Pacific Ocean southwest of Baja California on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Lorena was located at latitude 24.2°N and longitude 114.2°W which put the center about 125 miles (200 km) west-southwest of Cabo San Lazaro, Mexico.  Lorena was moving toward the northwest at 8 m.p.h. (13 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 991 mb.

A Tropical Storm Warning is in effect for the portion of the coast from Puerto Cortes to Punta Eugenia, Mexico.

Former Hurricane Lorena weakened to a tropical storm over the Eastern North Pacific Ocean southwest of Baja California on Thursday morning.  A upper level trough that is west of Baja California was producing southwesterly winds that were blowing toward the top of Lorena’s circulation.  Those winds were causing strong vertical wind shear.  The strong wind shear was pushing the middle and upper parts of Tropical Storm Lorena to the northeast of the surface circulation.  Thunderstorms were still occurring in bands in the northeastern part of Lorena’s circulation.  Bands in the other parts of Lorena consisted primarily of showers and lower clouds.

The circulation around Tropical Storm Lorena was small.  Winds to tropical storm force extended  out 70 miles (110 km) from the center of Lorena’s circulation.

Tropical Storm Lorena will move through an environment that will be unfavorable for intensification during the next 24 hours.  Lorena will move over water where the Sea Surface Temperatures are near 24°C.  The upper level trough that is west of Baja California will continue to cause strong vertical wind shear.  The combination of cool Sea Surface Temperatures and strong vertical wind shear will cause Tropical Storm Lorena to weaken steadily during the next 24 hours.

The strong vertical wind shear is likely to separate the lower portion of Tropical Storm Lorena from the middle and upper parts of Lorena’s circulation.  The lower portion of Lorena’s circulation could meander west of Baja California.  The middle and upper parts of Tropical Storm Lorena will be steered toward the northeast by the upper level trough that is west of Baja California.

The middle and upper parts of Tropical Storm Lorena will move across Baja California, over Sonora, and toward New Mexico and southeastern Arizona.  The middle and upper parts of Lorena’s circulation will bring gusty winds and locally heavy rain to those areas.  The strongest winds will occur in mountainous regions.  Heavy rain could cause flash floods in some locations.

Elsewhere, Hurricane Kiko continued to churn slowly toward Hawaii.  At 11:00 a.m. EDT on Thursday the center of Hurricane Kiko was located at latitude 13.8°N and longitude 133.7°W which put the center about 1470 miles (2365 km) east-southeast of Hilo Hawaii.  Kiko was moving toward the west at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 951 mb.