Category Archives: Tropical Cyclones

Information about tropical cyclones

Typhoon Saola Moves Back Toward Northern Luzon

Typhoon Saola moved back toward northern Luzon on Monday. At 11:00 p.m. EDT on Monday the center of Typhoon Saola was located at latitude 18.8°N and longitude 123.3°E which put it about 115 miles (185 km) east-northeast of Aparri, Philippines. Saola was moving toward the northwest at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (235 km/h). The minimum surface pressure was 951 mb.

Two concentric eyewalls formed in the core of Typhoon Saola on Monday. A small eye was at the center of Saola’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. A second, slightly larger ring of storms surrounded the inner eyewall. Bands of showers and thunderstorms were revolving around the concentric eyewalls. Storms in the eyewalls generated upper level divergence that pumped mass away from the typhoon.

The circulation around Typhoon Saola was small even with the two concentric eyewalls. Winds to typhoon force extended out 25 miles (40 km) from the center of Saola’s circulation. Winds to tropical storm force extended out 115 miles (185 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Saola was 20.6. The Hurricane Size Index (HSI) was 9.5 and the Hurricane Wind Intensity Size Index (HWISI) was 30.1. Typhoon Saola was similar in size and intensity to Hurricane Zeta when Zeta hit Louisiana in 2020.

Typhoon Saola will move through an environment favorable for intensification during the next 24 hours. Saola will move over water where the Sea Surface Temperatures are near 30°C. It will move through a region where the upper level ridge winds are weak and there will be little vertical wind shear. Typhoon Saola could intensify during the next 24 hours.

Typhoon Saola will move around the southwestern side of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Saola toward the northwest during the next 24 hours. On its anticipated track, Typhoon Saola will move between Luzon and Taiwan in 24 hours.

Typhoon Saola will bring strong winds and heavy rain to the islands north of Luzon. Saola could also drop heavy rains over parts of northern Luzon. Heavy rain is likely to cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Damrey moved quickly away from Japan and Tropical Storm Haikui formed south of Iwo To. At 11:00 p.m. EDT on Monday the center of Tropical Storm Damrey was located at latitude 41.2°N and longitude 152.3°E which put it about 285 miles (460 km) east-southeast of Hamanaka, Japan. Damrey was moving toward the east at 25 m.p.h. (40 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 990 mb.

At 11:00 p.m. EDT on Monday the center of Tropical Storm Haikui was located at latitude 19.2°N and longitude 137.6°E which put it about 450 miles (725 km) south-southwest of Iwo To. Haikui was moving toward the west-northwest at 17 m.p.h. (28 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 995 mb.

Tropical Storm Idalia Causes Hurricane Warning for West Coast of Florida

The imminent threat posed by Tropical Storm Idalia caused the issuance of a Hurricane Warning for the west coast of Florida on Monday morning. At 11:00 a.m. EDT on Monday the center of Tropical Storm Idalia was located at latitude 20.8°N and longitude 85.2°W which put it about 80 miles (130 km) south-southwest of the western end of Cuba. Idalia was moving toward the north at 8 m.p.h. (13 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 990 mb.

A Hurricane Warning was in effect for the portion of the coast from the Ochlockonee River to the middle of Longboat Key, Florida. The Hurricane Warning included Tampa Bay. A Hurricane Warning was also in effect for the Cuban Province of Pinar del Rio. A Hurricane Watch was in effect for the portions of the coast from Englewood to the middle of Longboat Key, Florida and from the Ochlockonee River to Indian Pass, Florida. A Tropical Storm Warning was in effect for the portion of the coast from Chokoloskee to the middle of Longboat Key, Florida. A Tropical Storm Warning was also in effect for the portion of the coast from the Ochlockonee River to Indian Pass, Florida. A Tropical Storm Warning was in effect for the Dry Tortugas. A Tropical Storm Warning was in effect for the portion of the coast from Tulum to Rio Lagartos, Mexico. The Tropical Storm Warning included Cozumel. A Tropical Storm Warning was also in effect for the Cuban Province. of Isle of Youth. A Tropical Storm Watch was in effect for the Lower Florida Keys west of Seven Mile Bridge. A Tropical Storm Watch was also in effect for the portion of the coast from Sebastian Inlet, Florida to Altamaha Sound, Georgia.

Tropical Storm Idalai strengthened gradually on Monday morning. Winds to tropical storm force extended out 100 miles (160 km) from the center of Idalia’s circulation. Even though Tropical Storm Idalia was stronger, the distribution of thunderstorms was asymmetrical. Most of the thunderstorms in Idalia were in bands in the southern and eastern parts of the circulation. Bands north and west of the center of circulation consisted primarily of showers and lower clouds. Tropical Storm Idalia was under the eastern part of an upper level ridge over the Yucatan Peninsula. The ridge was producing northeasterly winds that were blowing toward the top of Idalia’s circulation. Those winds were causing vertical wind shear and the wind shear was causing the asymmetrical distribution of thunderstorms.

Tropical Storm Idalia will move into an environment that will become more favorable for intensification during the next 24 hours. Idalia will be over water where the Sea Surface Temperatures are near 30°C. It will move into a region between the upper level ridge over the Yucatan Peninsula and an upper level low over the northern Gulf of Mexico. The upper level winds are weaker between the ridge and the low and there will be less vertical wind shear. Tropical Storm Idalia will intensify to a hurricane during the next 24 hours. Idalia could intensify rapidly when the upper level winds weaken. Idalia could strengthen to a major hurricane on Tuesday.

Tropical Storm Idalia will move around the western end of high pressure system over the western Atlantic Ocean. The high pressure system will steer Idalia toward the north during the next 24 hours. The center of Idalia will pass near the western end of Cuba in a few hours. On its anticipated track Tropical Storm Idalia will move over the eastern Gulf of Mexico on Monday night. An upper level trough over the eastern U.S. will turn Idalia toward the northeast later on Tuesday. Idalia is likely to make landfall on the west coast of Florida on Wednesday morning. Idalia could make landfall as a major hurricane.

Tropical Storm Idalia will drop heavy rain over parts of the northeastern Yucatan Peninsula and western Cuba. Heavy rain could cause flash floods in some locations.

Tropical Storm Idalia could be be a major hurricane when it reaches the west coast of Florida. Idalia is likely to make landfall in an area where high storm surges can occur. Idalia could cause a storm surge of up to 12 feet (3.5 meters) near where the center makes landfall. A Storm Surge Warning has been issued for the portion of the coast from Englewood to Ocholockonee River, Florida. The Storm Surge Warning includes Tampa Bay. Idalia will bring strong winds and heavy rain to parts of central and northern Florida. Widespread outages of electricity are likely. Heavy rain could cause flash floods in some locations.

Elsewhere, Hurricane Franklin rapidly intensified to Category 4 on the Saffir-Simpson Scale was over the Atlantic Ocean southwest of Bermuda. At 11:00 a.m. EDT on Monday the center of Hurricane Franklin was located at latitude 27.8°N and longitude 71.0°W which put it about 480 miles (770 km) southwest of Bermuda. Franklin was moving toward the north at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 170 m.p.h. (280 km/h). The minimum surface pressure was 937 mb. A Tropical Storm Watch was in effect for Bermuda.

Typhoon Saola Churns East of Luzon

Typhoon Saola continued to churn over the Western North Pacific Ocean east of Luzon on Sunday. At 11:00 p.m. EDT on Sunday the center of Typhoon Saola was located at latitude 17.0°N and longitude 124.4°E which put it about 200 miles (320 km) east-southeast of Aparri, Philippines. Saola was moving toward the northeast at 12 m.p.h. (19 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 941 mb.

Microwave satellite images showed that the inner end of a rainband was wrapping around the existing eye and eyewall at the center of Typhoon Saola. If the inner end of the rainband wraps completely around the existing eye and eyewall, then a second, larger outer eyewall would form. The formation of two concentric eyewalls would mark the start of an eyewall replacement cycle. An eyewall replacement cycle would cause Typhoon Saola to weaken.

There was still a small circular eye at the center of Typhoon Saola. The small eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Storms near the center of Saola’s circulation generated upper level divergence that pumped mass away from the typhoon.

The circulation around Typhoon Saola was small. Winds to typhoon force extended out 20 miles (30 km) from the center of Saola’s circulation. Winds to tropical storm force extended out 90 miles (145 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Saola was 25.1. The Hurricane Size Index (HSI) was 6.9 and the Hurricane Wind Intensity Size Index (HWISI) was 32.0. Typhoon Saola was similar in size and intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.

Typhoon Saola will move through an environment favorable for intensification during the next 24 hours. Saola will move over water where the Sea Surface Temperatures are near 30°C. It will move through a region where the upper level ridge winds are weak and there will be little vertical wind shear. However, an eyewall replacement cycle is likely to cause Typhoon Saola to weaken during the next 24 hours.

Typhoon Saola will move around the southwestern side of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Saola back toward the north during the next 24 hours. On its anticipated track, Typhoon Saola will move parallel to the coast of northeastern Luzon. Saola could move toward southern Taiwan later this week.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Damrey was passing east of Japan. At 11:00 p.m. EDT on Sunday the center of Tropical Storm Damrey was located at latitude 38.9°N and longitude 145.3°E which put it about 225 miles (360 km) southeast of Misawa, Japan. Damrey was moving toward the north-northeast at 14 m.p.h. (22 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 979 mb.

Tropical Storm Irwin Forms over the Eastern North Pacific

Tropical Storm Irwin formed over the Eastern North Pacific Ocean on Sunday. At 5:00 p.m. EDT on Sunday the center of Tropical Storm Irwin was located at latitude 17.2°N and longitude 121.3°W which put it about 835 miles (1315 km) west-southwest of the southern tip of Baja California. Irwin was moving toward the west-northwest at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 40 m.p.h. (60 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 998 mb.

A low pressure system over the Eastern North Pacific Ocean west-southwest of Baja California strengthened on Sunday and the U.S. National Hurricane Center designated the system as Tropical Storm Irwin. The distribution of thunderstorms in Irwin’s circulation was asymmetrical. Most of the thunderstorms were occurring in bands in the southern half of Tropical Storm Irwin. Bands in the northern side of Irwin’s circulation consisted primarily of showers and lower clouds. The distribution of winds in Tropical Storm Irwin was also asymmetrical. Winds to tropical storm force extended out 60 miles (95 km) in the eastern side of Irwin. The winds in the western side of the circulation were blowing at less than tropical storm force.

Tropical Storm Irwin will move through an environment that is only marginally favorable for intensification during the next 24 hours. Irwin will move over water where the Sea Surface Temperatures are near 26°C. It will move under the southwestern part of an upper level ridge over the Eastern North Pacific Ocean. The ridge will produce northeasterly winds that will blow toward the top of Irwin’s circulation. Those winds will cause moderate vertical wind shear and the wind shear will inhibit intensification. There is also a region of drier air northwest of Tropical Storm Irwin. Tropical Storm Irwin could get a little stronger on Monday, but the vertical wind shear and the drier air will limit any intensification.

Tropical Storm Irwin will move south of a subtropical high pressure system over the Eastern North Pacific Ocean. The high pressure system will steer Irwin toward the west during the next few days. On its anticipated track, Tropical Storm Irwin will move toward the Central Pacific Ocean.

Tropical Storm Idalia Prompts Hurricane Watch for West Coast of Florida

A risk posed by Tropical Storm Idalia prompted the issuance of a Hurricane Watch for part of the west coast of Florida. At 5:00 p.m. EDT on Sunday the center of Tropical Storm Idalia was located at latitude 20.1°N and longitude 85.5°W which put it about 95 miles (155 km) east-southeast of Cozumel. Idalia was moving toward the northeast at 3 m.p.h. (5 km/h). The maximum sustained wind speed was 40 m.p.h. (60 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 995 mb.

A Hurricane Watch was in effect for the portion of the coast from Englewood to Indian Pass, Florida. The Hurricane Watch included Tampa Bay. A Tropical Storm Warning was in effect for the portion of the coast from Tulum to Rio Lagartos, Mexico. The Tropical Storm Warning included Cozumel. A Tropical Storm Warning was also in effect for the Cuban Province. of Pinar del Rio. A Tropical Storm Watch was in effect for the portion of the coast from Englewood to Chokoloskee, Florida. A Tropical Storm Watch was also in effect for the Dry Tortugas. A Tropical Storm Watch was in effect for the Isle of Youth.

Tropical Storm Idalia did not change a lot on Sunday afternoon. A few more thunderstorms developed near the low level center of circulation. The low level center of circulation was meandering around inside of a larger counterclockwise rotation over the Northwestern Caribbean Sea. There were bands of showers and thunderstorms in the larger counterclockwise circulation. The thunderstorms in the larger circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 70 miles (110 km) from the low level center of circulation.

Tropical Storm Idalia will be in an environment mostly favorable for intensification during the next 24 hours. Idalia will be over water where the Sea Surface Temperatures are near 30°C. It will be under an upper level ridge over the Yucatan Channel. The winds are weak in the upper level ridge and there will be little vertical wind shear. However, much of the air moving around the western side of Tropical Storm Idalia will pass over the northeastern Yucatan Peninsula. Some of the air in the eastern side of the Idalia will pass over western Cuba. The flow of air over land will inhibit intensification, but it probably will not prevent intensification. Tropical Storm Idalia could intensify slowly during the next 12 hours. Idalia could intensify more quickly on Monday when it moves over the eastern Gulf of Mexico. Tropical Storm Idalia is forecast to strengthen to a hurricane by Monday night

.Tropical Storm Idalia will be in a region where the steering currents are weak during the next 12 hours. Idalia may not move much during that time period. A high pressure system over the western Atlantic Ocean will start to steer Idalia toward the north on Monday. On its anticipated track Tropical Storm Idalia will move over the eastern Gulf of Mexico on Monday. An upper level trough over the eastern U.S. could start to turn Idalia toward the northeast later on Tuesday.

Tropical Storm Idalia will drop heavy rain over parts of the northeastern Yucatan Peninsula and western Cuba. Heavy rain could cause flash floods in some locations.

Tropical Storm Idalia is forecast to be a hurricane when it reaches the west coast of Florida. Idalia is likely to make landfall in an area where high storm surges can occur. Idalia could cause a storm surge of up to 11 feet (3.3 meters) near where the center makes landfall. A Storm Surge Watch has been issued for the portion of the coast from Chokoloskee to Indian Pass, Florida. The Storm Surge Watch includes Tampa Bay.

Elsewhere, Hurricane Franklin was over the Atlantic Ocean southwest of Bermuda. At 5:00 p.m. EDT on Sunday the center of Hurricane Franklin was located at latitude 25.9°N and longitude 70.0°W which put it about 535 miles (855 km) southwest of Bermuda. Franklin was moving toward the north-northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h). The minimum surface pressure was 970 mb.

TD 10 Strengthens to Tropical Storm Idalia

Former Tropical Depression Ten strengthened to Tropical Storm Idalia over the Northwestern Caribbean Sea east of the Yucatan Peninsula on Sunday morning. At 11:00 a.m. EDT on Sunday the center of Tropical Storm Idalia was located at latitude 19.9°N and longitude 85.8°W which put it about 80 miles (130 km) east-southeast of Cozumel. Idalia was moving toward the east at 2 m.p.h. (3 km/h). The maximum sustained wind speed was 40 m.p.h. (60 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1001 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Tulum to Rio Lagartos, Mexico. The Tropical Storm Warning included Cozumel. A Tropical Storm Warning was also in effect for the Cuban Province. of Pinar del Rio. A Tropical Storm Watch was in effect for the Isle of Youth.

A NOAA research aircraft found sustained tropical storm force winds in former Tropical Depression Ten on Sunday morning and the U.S. National Hurricane Center upgraded the system to Tropical Storm Idalia. There was a low level center of circulation meandering around inside of a larger counterclockwise rotation over the Northwestern Caribbean Sea. Thunderstorm activity fluctuated near the low level center of circulation. There were few thunderstorms currently near the low level center. There were bands of showers and thunderstorms in the larger counterclockwise circulation. The thunderstorms in the larger circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 35 miles (50 km) from the low level center of circulation.

Tropical Storm Idalia will be in an environment mostly favorable for intensification during the next 24 hours. The tropical depression will be over water where the Sea Surface Temperatures are near 30°C. It will be under an upper level ridge over the Yucatan Channel. The winds are weak in the upper level ridge and there will be little vertical wind shear. However, much of the air moving around the western side of Tropical Storm Idalia will pass over the northeastern Yucatan Peninsula. Some of the air in the eastern side of the Idalia will pass over western Cuba. The flow of air over land will inhibit intensification, but it probably will not prevent intensification. Tropical Storm Idalia could intensify slowly on Sunday. Idalia could intensify to a hurricane early next week when it moves over the eastern Gulf of Mexico.

Tropical Storm Idalia will be in a region where the steering currents are weak during the next 12 hours. Idalia may not move much during the rest of Sunday. A high pressure system over the western Atlantic Ocean will start to steer Idalia toward the north on Monday. On its anticipated track Tropical Storm Idalia Ten will move over the eastern Gulf of Mexico on Monday.

Tropical Storm Idalia will drop heavy rain over parts of the northeastern Yucatan Peninsula and western Cuba. Heavy rain could cause flash floods in some locations.

Elsewhere, Hurricane Franklin continued to strengthen over the Atlantic Ocean south-southwest of Bermuda. At 11:00 a.m. EDT on Sunday the center of Hurricane Franklin was located at latitude 25.1°N and longitude 69.3°W which put it about 565 miles (905 km) south-southwest of Bermuda. Franklin was moving toward the north-northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h). The minimum surface pressure was 971 mb.

Tropical Depression Ten Forms over the Yucatan Channel

Tropical Depression Ten formed over the Yucatan Channel on Saturday afternoon. At 5:00 p.m. EDT on Saturday the center of Tropical Depression Ten was located at latitude 21.1°N and longitude 86.1°W which put it about 65 miles (105 km) northeast of Cozumel. The tropical depression was stationary. 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 1006 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Tulum to Rio Lagartos, Mexico. The Tropical Storm Warning included Cozumel. A Tropical Storm Warning was also in effect for the Cuban Provinces of Pinar del Rio and Isle of Youth.

A low pressure system over the Yucatan Peninsula exhibited more organization on Saturday afternoon and the U.S. National Hurricane Center designated it as Tropical Depression Ten. The circulation around Tropical Depression Ten was still organizing. There was a weak center of circulation at the surface. Radar images from western Cuba indicated that there was a stronger circulation in the middle troposphere. Bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center started to generate upper level divergence that pumped mass away from the tropical depression.

Tropical Depression Ten will be in an environment mostly favorable for intensification during the next 24 hours. The tropical depression will be over water where the Sea Surface Temperatures are near 30°C. It will be under an upper level ridge over the Yucatan Channel. The winds are weak in the upper level ridge and there will be little vertical wind shear. However, much of the air moving around the western side of Tropical Depression Ten will pass over the northeastern Yucatan Peninsula. Some of the air in the western side of the tropical depression will pass over western Cuba. The flow of air over land will inhibit intensification, but it probably will not prevent intensification. Tropical Depression Ten could intensify slowly on Sunday.

Tropical Depression Ten will be in a region where the steering currents are weak during the next 24 hours. Tropical Depression Ten may not move much on Sunday. A high pressure system over the western Atlantic Ocean will start to steer the tropical depression toward the north early next week. Tropical Depression Ten is likely to strengthen when it moves over the eastern Gulf of Mexico.

Tropical Depression Ten will drop heavy rain over parts of the northeastern Yucatan Peninsula and western Cuba. Heavy rain could cause flash floods in some locations.

Elsewhere, Hurricane Franklin strengthened over the Atlantic Ocean south-southwest of Bermuda. At 5:00 p.m. EDT on Saturday the center of Hurricane Franklin was located at latitude 23.8°N and longitude 67.5°W which put it about 610 miles (980 km) south-southwest of Bermuda. Franklin was moving toward the north-northwest at 8 m.p.h. (13 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 982 mb.

Franklin Intensifies to a Hurricane

Former Tropical Storm Franklin intensified to a hurricane over the Atlantic Ocean south-southeast of Bermuda on Saturday morning. At 11:00 a.m. EDT on Saturday the center of Hurricane Franklin was located at latitude 23.5°N and longitude 66.7°W which put it about 620 miles (995 km) south-southwest of Bermuda. Franklin was moving toward the north-northwest at 7 m.p.h. (11km/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 989 mb.

Tropical Storm Franklin moved under the northeastern part of an upper level low centered near the southeastern Bahamas. When Franklin moved under the northeastern part of the upper level low, it moved into a region where there was less vertical wind shear. Less wind shear allowed the inner end of a rainband to wrap around the center of Franklin’s circulation. A small eye appeared to be forming at the center of Hurricane Franklin. Storms near the center of Franklin’s circulation generated upper level divergence that pumped mass away to the northeast of the hurricane. Bands of showers and thunderstorms were revolving around the center of Hurricane Franklin.

The strongest winds were occurring just to the northeast of the developing eye of Hurricane Franklin. Winds to hurricane force extended out 15 miles (25 km) to the northeast of the center of Franklin’s circulation. Winds to tropical storm force extended out 140 miles (220 km) from the center of Hurricane Franklin.

Hurricane Franklin will move through an environment favorable for intensification during the next 24 hours. Franklin will move over water where the Sea Surface Temperatures are near 30°C. Ir will move under an upper level ridge south of Bermuda. The ridge will enhance upper level divergence that will pump mass away from Franklin. The removal of mass will cause the surface pressure to decrease. Hurricane Franklin is likely to intensify during the next 24 hours.

Hurricane Franklin will move around the western part of a subtropical high pressure system over the Atlantic Ocean. The high pressure system will steer Franklin toward the north-northwest during the next 24 hours. On its anticipated track, Hurricane Franklin will move southwest of Bermuda.

Typhoon Saola Strengthens to Equivalent of a Major Hurricane

Typhoon Saola strengthened to the equivalent of a major hurricane over the Western North Pacific Ocean near northern Luzon on Saturday morning. At 5:00 a.m. EDT on Saturday the center of Typhoon Saola was located at latitude 17.8°N and longitude 123.3°E which put it about 100 miles (160 km) east-southeast of Aparri, Philippines. Saola was moving toward the south 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 953 mb.

Typhoon Saola rapidly intensified to the equivalent of a major hurricane during the past 24 hours. A small circular eye with a diameter of 12 miles (19 km) was at the center of Saola’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 core of Typhoon Saola. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the typhoon.

The circulation around Typhoon Saola was small. Winds to typhoon force extended out 30 miles (50 km) from the center of Saola’s circulation. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Saola was 22.1. The Hurricane Size Index (HSI) was 10.9 and the Hurricane Wind Intensity Size Index (HWISI) was 33.0. Typhoon Saola was similar in size and intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.

Typhoon Saola will move through an environment favorable for intensification during the next 24 hours. Saola will move over water where the Sea Surface Temperatures are near 30°C. It will move through a region where the upper level ridge winds are weak and there will be little vertical wind shear. Typhoon Saola is likely to intensify during the next 24 hours.

Typhoon Saola will move around the western side of a large counterclockwise monsoon gyre east of the Philippines. The monsoon gyre will pull Saola toward the southeast during the next 24 hours. A high pressure system over the Western North Pacific Ocean will start to steer Saola back toward the northwest by the end of the weekend. On its anticipated track, Typhoon Saola is forecast to make a slow counterclockwise loop east of Luzon.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Damrey was southeast of Japan. At 5:00 a.m. EDT on Saturday the center of Tropical Storm Damrey was located at latitude 26.9°N and longitude 152.1°E which put it about 1020 miles (1645 km) southeast of Tokyo, Japan. Damrey was moving toward the north-northwest at 25 m.p.h. (40 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 987 mb.

Strong Upper Level Winds Shear Top Off Tropical Storm Franklin

Strong upper level winds sheared the top off of Tropical Storm Franklin on Friday morning. At 11:00 a.m. EDT on Friday the center of Tropical Storm Franklin was located at latitude 21.8°N and longitude 67.8°W which put it about 215 miles (340 km) east-northeast of Grand Turk Island. Franklin was moving toward the east-southeast at 5 m.p.h. (8 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.

An upper level trough northeast of the Bahamas produced strong west-northwesterly winds that blew the top off of Tropical Storm Franklin on Friday morning. The strong upper level winds sheared off the tops of thunderstorms near the center of Franklin’s circulation and in the western side of the tropical storm. Bands near the center of Tropical Storm Franklin and in the western half of the circulation consisted primarily of showers and lower clouds. The remaining thunderstorms were occurring in bands in the southeastern part of Franklin’s circulation

The strong vertical wind shear also affected the distribution of winds in Tropical Storm Franklin. Winds to tropical storm force extended out 115 miles (185 km) in the eastern side of Franklin’s circulation. Winds to tropical storm force only extended out 35 miles (55 km) in the western half of the circulation.

Tropical Storm Franklin will move through an environment only marginally favorable for intensification during the next 24 hours. Franklin will move over water where the Sea Surface Temperatures are near 30°C. However, the upper level trough northeast of the Bahamas will continue to produce west-northwesterly winds that will blow toward the top of Franklin’s circulation. Those winds will continue to cause strong vertical wind shear. The wind shear will inhibit intensification and the shear could be strong enough to cause Tropical Storm Franklin to weaken during the next 24 hours.

The upper level trough east of Florida will steer Tropical Storm Franklin toward the east during the rest of Friday. The upper level trough could turn Franklin toward the north on Saturday. On its anticipated track, Tropical Storm Franklin will move farther away from the Turks and Caicos. Franklin is forecast to remain well to the north of Puerto Rico.