Monthly Archives: October 2021

Subtropical Storm Wanda Develops West of the Azores

Subtropical Storm Wanda developed over the central Atlantic Ocean west of the Azores on Saturday night. At 11:00 p.m. EDT on Saturday the center of Subtropical Storm Wanda was located at latitude 36.2°N and longitude 45.4°W which put it about 1020 miles (1640 km) west of the Azores. Wanda was moving toward the southeast at 21 m.p.h. (33 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.

More thunderstorms formed near the center of a low pressure system over the central Atlantic Ocean and the National Hurricane Center designated the system as Subtropical Storm Wanda. Subtropical Storm Wanda began as an extratropical cyclone that formed near the East Coast of the U.S. The extratropical cyclone brought very strong winds to the northeastern U.S. several days ago before moving toward the central Atlantic Ocean. The extratropical cyclone became vertically stacked where the surface low pressure system was under the axis of the upper level trough. The vertical wind shear decreased when the system became vertically stacked. When the extratropical cyclone moved southeast over warmer water, the temperature difference on the opposing sides of fronts decreased and the fronts weakened. More thunderstorms developed near the center of the low pressure system and it assumed a more circular shape. The strongest winds eventually started to blow closer to the center and the National Hurricane Center designated it as Subtropical Storm Wanda.

Subtropical Storm Wanda exhibited some characteristics of a tropical cyclone. Thunderstorms formed near the center of Wanda. Bands of showers and thunderstorms formed and started to revolve around the center of circulation. The strongest rainband wrapped around the northern and eastern sides of the center of Subtropical Storm Wanda. Even though Wanda exhibited some of the characteristics of a tropical cyclone, it was under the axis of an upper level trough, which is why it was classified as a subtropical storm. Winds to tropical storm force extended out 100 miles (160 km) from the center of Subtropical Storm Wanda.

Subtropical Storm Wanda will move through an environment somewhat favorable for intensification during the next 24 hours. Wanda will move over water where the Sea Surface Temperatures are near 24˚C. It will remain under the axis of the upper level trough and there will be little vertical wind shear. Subtropical Storm Wanda is likely to strengthen during the next 24 hours. There is a chance it could intensify to a hurricane during the next several days.

Subtropical Storm Wanda will move along with the upper level trough during the next 24 hours. The upper level trough will carry Wanda slowly toward the southeast during the next several days. On its anticipated track Subtropical Storm Wanda could meander west-southwest of the Azores for several days.

Medicane Drops Heavy Rain on Sicily

A low pressure system sometimes called a medicane dropped heavy rain over parts of Sicily on Friday. There were reports of flash floods in eastern Sicily. At 8:00 a.m. EDT on Friday the center of the low pressure system was located at latitude 36.5°N and longitude 16.1°E which put it about 50 miles (80 km) southeast of Siracusa, Italy. The low pressure system was nearly stationary. 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.

A small low pressure system located over the Mediterranean Sea just to southeast of Sicily exhibited some of the characteristics associated with tropical cyclones. The low pressure system looked similar to a subtropical cyclone on satellite images. Low pressure systems over the Mediterranean Sea with this type of structure are sometimes called medicanes. The current medicane southeast of Sicily has a symmetrical circulation with a well defined center of circulation. Bands of showers and thunderstorms are revolving around the center of the medicane. The strongest thunderstorms are occurring in bands in the northern and westerns sides of the circulation. Some of those bands dropped heavy rains parts of eastern Sicily. There have been reports of flash floods in some locations because of persistent heavy rain.

The medicane is in an area where the steering winds are weak and it is likely to remain nearly stationary during the next 24 hours. It is in an environment that should allow it to maintain its intensity during the next 24 hours. The medicane will be over water in the Mediterranean Sea where the Sea Surface Temperatures are near 24˚C. It will be in an area where the upper level winds are weak and there will be little vertical wind shear. The strongest winds are likely to remain over the Mediterranean Sea southeast of Sicily. However, rainbands on the western side of the medicane will continue to drop heavy rain over parts of Sicily. Additional flash floods are likely to occur. The medicane is forecast to move southeast toward Libya during the weekend.

Typhoon Malou Brings Strong Winds, Rain to Ogasawara Islands

Typhoon Malou brought strong winds and heavy rain to the Ogasawara Islands on Thursday morning. At 5:00 a.m. EDT on Thursday the center of Typhoon Malou was located at latitude 25.6°N and longitude 141.2°E which put it about 15 miles (25 km) east of Iwo To. Malou was moving toward the north-northeast at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 100 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h). The minimum surface pressure was 967 mb.

The strong inner core of Typhoon Malou passed directly over Iwo To on Thursday morning. An eye with a diameter of 35 miles (55 km) was at the center of Malou. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. Winds to typhoon force extended out 70 miles (110 km) from the center of Malou. Winds to tropical storm force extended out 175 miles (280 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Malou was 16.5. The Hurricane Size Index (HSI) was 20.6 and the Hurricane Wind Intensity Size Index (HWISI) was 37.1.

An upper level trough near Japan will steer Typhoon Malou toward the northeast during the next several days. On its anticipated track Malou will move away from the Ogasawara Islands. Typhoon Malou will pass well to the southeast of the larger islands of Japan.

Typhoon Malou will move into an environment unfavorable for tropical cyclones during the next few days. Malou will move over water where the Sea Surface Temperatures are cooler. The upper level trough near Japan will produce stronger southwesterly winds that will blow toward the top of Malou’s circulation. The vertical wind shear will increase as the upper level winds get stronger. The combination of cooler water and stronger vertical wind shear will cause Typhoon Malou to weaken. The cooler water and stronger shear will also cause Malou to make a transition to an extratropical cyclone during the next few days.

Typhoon Malou Nears Iwo To

Typhoon Malou neared Iwo To on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Typhoon Malou was located at latitude 24.2°N and longitude 141.3°E which put it about 100 miles (160 km) south-southwest of Iwo To. Malou was moving toward the north-northeast at 14 m.p.h. (22km/h). The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 105 m.p.h. (165 km/h). The minimum surface pressure was 970 mb.

Typhoon Malou strengthened as it moved closer to Iwo To on Wednesday night. A very large eye with a diameter of 90 miles (145 km) was at the center of Malou. Several smaller counterclockwise circulations were rotating within the eye. 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 large core of Typhoon Malou. Storms near the core generated upper level divergence that pumped mass away to the northeast of the typhoon.

The size of Typhoon Malou’s circulation increased on Wednesday. Winds to typhoon force extended out 60 miles (95 km) from the center of Malou. Winds to tropical storm force extended out 175 miles (280 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Malou was 13.9. The Hurricane Size Index (HSI) was 14.6 and the Hurricane Wind Intensity Size Index (HWISI) was 28.5.

Typhoon Malou will move through an environment favorable for intensification during the next 18 hours. Malou will move over water where the Sea Surface Temperatures are near 28˚C. An upper level trough near Japan will produce southwesterly winds that will blow toward the top of Malou’s circulation. However, the winds in the lower levels of the atmosphere will also blow from the southwest and so there will not be a lot of vertical wind shear. Typhoon Malou is could strengthen during the next 18 hours. The upper level winds will get stronger on Friday and the vertical wind shear will increase. Malou is likely to weaken and to begin a transition to an extratropical cyclone when the wind shear increases.

An upper level trough over Japan will steer Typhoon Malou toward the north-northeast during the next 24 hours. On its anticipated track Typhoon Malou could make a direct hit on Iwo To in a few hours. Typhoon Malou will bring strong winds and heavy rain to Iwo To. The eyewall with the strongest winds is likely to pass over Iwo To. The wind could blow at tropical storm force or greater for several hours. Malou will be capable of causing serious damage on Iwo To. In addition, heavy rain could also cause flash floods.

Malou Strengthens to a Typhoon South-southwest of Iwo To

Former Tropical Storm Malou strengthened to a typhoon over the Western North Pacific Ocean south-southwest of Iwo To on Tuesday night. At 11:00 p.m. EDT on Tuesday the center of Typhoon Malou was located at latitude 21.0°N and longitude 139.4°E which put it about 310 miles (500 km) south-southwest of Iwo To. Malou was moving toward the north-northeast at 3 m.p.h. (5 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 981 mb.

Former Tropical Storm Malou intensified to a typhoon on Tuesday night. The inner end of a rainband wrapped around the center of Typhoon Malou and an eye appeared intermittently on satellite images. A broken ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Malou’s circulation. Storms near the core generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 80 miles (130 km) from the center of Malou. Winds to tropical storm force extended out 165 miles (270 km) from the center of circulation.

Typhoon Malou will move through an environment favorable for intensification during the next 24 hours. Malou will move over water where the Sea Surface Temperatures are near 29˚C. It will move under an upper level ridge south of Japan. The upper level winds are weak in the ridge and there will be little vertical wind shear. The upper level ridge will enhance divergence which will cause the surface pressure to decrease. Typhoon Malou is likely to strengthen during the next 24 hours. Malou could intensify rapidly if an inner core with an eye and a complete eyewall develops.

An upper level trough over Japan will steer Typhoon Malou toward the north-northeast during the next 24 hours. On its anticipated track Typhoon Malou could make a direct hit on Iwo To in 24 hours. Typhoon Malou will bring strong winds and heavy rain to Iwo To. Malou will be capable of causing serious damage on Iwo To. Heavy rain could also cause flash floods.

Hurricane Rick Makes Landfall on West Coast of Mexico

Hurricane Rick made landfall on the west coast of Mexico on Monday morning. At 8:00 a.m. EDT on Monday the center of Hurricane Rick was located at latitude 18.2°N and longitude 102.1°W which put it about 15 miles (25 km) north-northeast of Lazaro Cardenas, Mexico. Rick was moving toward the north at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h). The minimum surface pressure was 977 mb.

A Hurricane Warning was in effect for the portion of the coast from Tecpan De Galeana to Punta San Telmo, Mexico. Tropical Storm Warnings were in effect for the portions of the coast from Punta San Telmo to Manzanillo and from Tecpan de Galeana to Acapulco, Mexico.

Hurricane Rick made landfall on the west coast of Mexico between Zihuatenajo and Lazaro Cardenas on Monday morning. Rick intensified before it made landfall. The maximum sustained wind speed increased to 105 m.p.h. (165 km/h) which made Rick a Category 2 hurricane on the Saffir-Simpson Scale. Even though Hurricane Rick intensified, the circulation remained relative small. Winds to hurricane force extended out 25 miles (40 km) from the center of Rick. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation.

The Hurricane Intensity Index (HII) for Hurricane Rick was 17.8. The Hurricane Size Index (HSI) was 8.2 and the Hurricane Wind Intensity Size Index (HWISI) was 26.0. Hurricane Rick was capable of causing regionalized serious damage.

Hurricane Rick was bringing strong winds and locally heavy rain to the portion of the coast between Lazaro Cardenas and Zihuatenajo. There were reports of damage in Ixtapa. Winds blowing water toward the coast were causing a storm surge. Heavy rain was falling over parts of Guerrero and Michoacan. The heavy rain could cause flash floods in some locations. Hurricane Rick will weaken steadily now that the center is inland. However, heavy rain will spread over inland sections of Guerrero and Michoacan and flash floods could occur in those areas.

Tropical Storm Malou Forms West of the Marianas

Tropical Storm Malou formed west of the Marianas on Sunday night. At 11:00 p.m. EDT on Sunday the center of Tropical Storm Malou was located at latitude 16.5°N and longitude 138.1°E which put it about 515 miles (830 km) west-northwest of Saipan. Malou was moving toward the north-northwest 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 1003 mb.

The circulation around a low pressure system over the Western North Pacific Ocean west of the Marianas strengthened on Sunday night and the Japan Meteorological Agency designated the system as Tropical Storm Malou. The circulation around Tropical Storm Malou was still organizing. There was a broad center of circulation, but there were not many thunderstorms near the center of Malou. Several long rainbands were revolving around the broad center of circulation. The strongest winds were occurring in the eastern half of Malou. Winds to tropical storm force extended out 185 miles (295 km) on the eastern side of Malou. The winds in the western half of Malou’s circulation were blowing at less than tropical storm force.

Tropical Storm Malou will move through an environment favorable for intensification during the next 48 hours. Malou will move over water where the Sea Surface Temperatures are near 29˚C. It will move under an upper level ridge near the Marianas. The upper level winds are weak in the ridge and there will be little vertical wind shear. Tropical Storm Malou is likely to intensify steadily during the next 48 hours. Malou could strengthen to a typhoon in 48 hours.

Tropical Storm Malou will move around the western end of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Malou toward the west-northwest during the next 48 hours. Tropical Storm Malou will turn toward the northeast after it moves around the western end of the ridge. On its anticipated track Malou could approach Iwo To in three days. Malou could be a typhoon when it approaches Iwo To.

Hurricane Rick Moves Toward Mexico

Hurricane Rick moved slowly toward the west coast of Mexico on Sunday afternoon. At 2:00 p.m. EDT on Sunday the center of Hurricane Rick was located at latitude 16.4°N and longitude 101.7°W which put it about 85 miles (135 km) south of Zihuatenajo, Mexico. Rick was moving toward the north at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h). The minimum surface pressure was 980 mb.

A Hurricane Warning was in effect for the portion of the coast from Tecpan De Galeana to Punta San Telmo, Mexico. Tropical Storm Warnings were in effect for the portions of the coast from Punta San Telmo to Manzanillo and from Tecpan de Galeana to Acapulco, Mexico.

The intensity of Hurricane Rick was steady during the past few hours. The inner core of Rick’s circulation was not as well organized as it was on Saturday afternoon. There were breaks in the ring of thunderstorms surrounding the center of Hurricane Rick. Storms near the center of circulation continued to generate upper level divergence that pumped mass away from the hurricane. Bands of showers and thunderstorms revolved around the center of Rick. The circulation around Hurricane Rick was small. Winds to hurricane force extended out 15 miles (25 km) from the center of Rick. Winds to tropical storm force extended out 60 miles (95 km) from the center of circulation.

Hurricane Rick will move through an environment favorable for intensification during the next 12 hours. Rick will move over water where the Sea Surface Temperatures are near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Hurricane Rick could intensify during the next 12 hours. However, the less organized core of Rick will limit intensification. An upper level trough near the west coast of the U.S. will produce strong southwesterly winds that will blow toward the top of Rick’s circulation on Monday. Those winds will cause vertical wind shear and the shear could cause Hurricane Rick to weaken as it nears the coast of Mexico.

Hurricane Rick will move around the western part of a high pressure system over Mexico during the next 24 hours. A large upper level trough near the west coast of the U.S. will cause the high pressure system to weaken. As the high pressure system weakens, the southern part of the upper level trough will steer Rick toward the north. On its anticipated track Hurricane Rick could make landfall on the west coast of Mexico on Sunday night. Hurricane Rick will bring strong winds and locally heavy rain to the portion of the coast near Zihuatanejo. Heavy rain could cause flash floods in parts of Guerrero and Michoacan on Sunday night and Monday.

Rick Rapidly Intensifies to a Hurricane South of Mexico

Former Tropical Storm Rick rapidly intensified to a hurricane south of Mexico early on Saturday. At 8:00 a.m. EDT on Saturday the center of Hurricane Rick was located at latitude 14.3°N and longitude 101.5°W which put it about 235 miles (380 km) south of Zihuatenajo, Mexico. Rick was moving toward the north-northwest at 6 m.p.h. (10 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.

A Hurricane Watch was in effect for the portion of the coast from Tecpan De Galeana to Punta San Telmo, Mexico. Tropical Storm Watches were in effect for the portions of the coast from Punta San Telmo to Manzanillo and from Tecpan de Galeana to Acapulco, Mexico.

Former Tropical Storm Rick intensified rapidly during Friday night and it strengthened to a hurricane early on Saturday. A small eye formed at the center of Hurricane Rick. 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 Rick’s circulation. Storms near the core generated upper level divergence that pumped mass away from the hurricane. The removal of mass allowed the surface pressure to decrease quickly. The circulation around Hurricane Rick was small. Winds to hurricane force extended out 15 miles (25 km) from the center of Rick. Winds to tropical storm force extended out 60 miles (95 km) from the center of circulation.

Hurricane Rick will move through an environment very favorable for intensification during the next 24 hours. Rick will move over water where the Sea Surface Temperatures are near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Hurricane Rick will likely continue to intensify rapidly during the next 24 hours. Rick could strengthen to a major hurricane on Sunday.

Hurricane Rick will move around the western part of a high pressure system over Mexico during the next 24 hours. A large upper level trough approaching the west coast of the U.S. will cause the high pressure system to weaken during the weekend. As the high pressure system weakens, the southern part of the upper level trough will steer Rick toward the north. On its anticipated track Hurricane Rick could approach the west coast of Mexico by later on Sunday. Rick could be a major hurricane when it approaches the coast of Mexico. The Hurricane and Tropical Storm Watches are likely to be changed to warnings later today. Hurricane Rick could bring strong winds and heavy rain to Guerrero and Michoacan on Sunday night and Monday.

TD 17E Strengthens to Tropical Storm Rick, Mexico Issues Watches

Former Tropical Depression Seventeen-E strengthened to Tropical Storm Rick on Friday afternoon and the government of Mexico issued a Hurricane Watch and Tropical Storm Watches for portions of the coast. At 5:00 p.m. EDT on Friday the center of Tropical Storm Rick was located at latitude 13.1°N and longitude 101.0°W which put it about 460 miles (745 km) south-southeast of Manzanillo, Mexico. Rick was moving toward the west-northwest at 7 m.p.h. (11 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.

A Hurricane Watch was issued for the portion of the coast from Zihuatenajo to Punta San Telmo, Mexico. Tropical Storm Watches were issued for the portions of the coast from Punta San Telmo to Manzanillo and from Zihuatenajo to Tecpan de Galeana, Mexico.

The circulation around former Tropical Depression Seventeen-E strengthened on Friday afternoon and the National Hurricane Center upgraded the system to Tropical Storm Rick. The inner end of a rainband wrapped around the western and southern sides of the center of Tropical Storm Rick. Other bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center generated upped level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 45 miles (75 km) in the northern half of Tropical Storm Rick. The winds in the southern half of the circulation were blowing at less than tropical storm force.

Tropical Storm Rick will move through an environment favorable for intensification during the next 36 hours. Rick will move over water where the Sea Surface Temperatures are near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Rick will continue to intensify steadily during the next 36 hours. Rick could strengthen to a hurricane on Saturday.

Tropical Storm Rick will move around the southern part of a high pressure system over Mexico during the next few hours. A large upper level trough approaching the west coast of the U.S. will cause the high pressure system to weaken during the weekend. When the high pressure system weakens, the southern part of the upper level trough will turn Rick toward the north-northwest. On its anticipated track Tropical Storm Rick could approach the west coast of Mexico by later on Sunday. Rick could be a hurricane when it approaches the coast of Mexico. The Hurricane and Tropical Storm Watches are likely to be changed to warnings on Saturday.