Monthly Archives: September 2021

Tropical Storm Mindy Forms near Florida Panhandle

Tropical Storm Mindy formed near the Florida Panhandle on Wednesday afternoon. At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Mindy was located at latitude 29.0°N and longitude 86.3°W which put it about 90 miles (145 km) west-southwest of Apalachicola, Florida. Mindy was moving toward the northeast at 21 m.p.h. (33 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 1008 mb.

A Tropical Storm Warning was issued for the portion of the coast from Mexico Beach to the Steinhatchee River, Florida.

A surface low pressure system spun up quickly near the Florida Panhandle on Wednesday afternoon and the National Hurricane Center designated the system as Tropical Storm Mindy. More thunderstorms were forming near the center of Mindy. Storms near the center started to generate upper level divergence that pumped mass away to the northeast of the tropical storm. The removal of mass caused the surface pressure to decrease. NOAA buoy 42039 reported a sustained wind speed of 38 m.p.h. (61 km/h) and a wind gust of 51 m.p.h. (83 km/h) at 4:40 p.m. EDT. The buoy also reported a surface pressure of 1007.8 mb.

Tropical Storm Mindy could strengthen a little during the next few hours before it makes landfall on the coast of Northwest Florida. Mindy will move over water where the Sea Surface Temperature is near 30˚C. It will move under the eastern side of an upper level low over the western Gulf of Mexico. The upper low will produce southwesterly winds that will blow toward the top of Mindy’s circulation. Those winds will cause moderate vertical wind shear and the shear will limit potential intensification.

The upper level low will steer Tropical Storm Mindy quickly toward the northeast during the next 12 hours. On its anticipated track Tropical Storm Mindy will make landfall on the coast near Port St. Joe, Florida on Wednesday evening. Mindy will move more toward the east-northeast on Thursday when it reaches the westerly winds in the middle latitudes. Tropical Storm Mindy will produce gusty winds along the coast of Northwest Florida. Mindy could drop locally heavy rain over parts of northern Florida and southern Georgia. Flash Flood Watches are in effect for parts of northern Florida. Southerly winds on the eastern side of Tropical Storm Mindy will push waves toward the coast and some beach erosion is likely.

Elsewhere, Hurricane Larry moved closer to Bermuda on Wednesday afternoon. At 5:00 p.m. EDT on Wednesday the center of Hurricane Larry was located at latitude 28.9°N and longitude 59.2°W which put it about 405 miles (655 km) southeast of Bermuda. Larry was moving toward the northwest at 15 m.p.h. (24 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 966 mb. A Tropical Storm Warning was in effect for Bermuda.

Tropical Storm Olaf Develops West of Mexico

Tropical Storm Olaf developed west of Mexico on Wednesday morning. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Olaf was located at latitude 18.9°N and longitude 107.5°W which put it about 315 miles (510 km) south-southeast of Cabo San Lucas, Mexico. Olaf was moving toward the 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 Tropical Storm Watch was in effect for the portion of the coast from Los Barriles to Santa Fe, Mexico.

The circulation around former Tropical Depression Fifteen-E strengthened on Wednesday morning and the National Hurricane Center designated the system as Tropical Storm Olaf. The inner end of a rainband wrapped around the northern side of the center of Olaf. Other bands of showers and thunderstorms were revolving around the center of circulation. Storms near the center generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 45 miles (75 km) in the northeastern quadrant of Olaf. The winds were blowing at less than tropical storm force in the other parts of the circulation.

Tropical Storm Olaf will move through an environment favorable for intensification during the next 24 hours. Olaf will move over water where the Sea Surface Temperature is near 29˚C. It will move south of an upper level ridge over the southwestern U.S. The ridge will produce northeasterly winds that will blow toward the top of Olaf’s circulation. Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification of Tropical Storm Olaf. Olaf will strengthen during the next 24 hours and there is a chance it could intensify to a hurricane.

Tropical Storm Olaf will move around the western side of a high pressure system over Mexico. The high will steer Olaf toward the northwest during the next 24 hours. On its anticipated track Tropical Storm Olaf could approach the southern end of Baja California on Thursday. Olaf could bring gusty winds and locally heavy rain to southern Baja California.

Typhoon Chanthu Strengthens to Equivalent of Cat. 5 Hurricane

Typhoon Chanthu intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale east of northern Luzon on Wednesday. At 5:00 a.m. EDT on Wednesday the center of Typhoon Chanthu was located at latitude 15.5°N and longitude 130.8°E which put it about 630 miles (1015 km) east-southeast of Aparri, Philippines. Chanthu was moving toward the west-southwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h). The minimum surface pressure was 915 mb.

Typhoon Chanthu intensified to the equivalent of a Category 5 hurricane on Wednesday morning. A small eye was at the center of Typhoon Chanthu. 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 revolved around the core of Chanthu. Storms near the core generated strong upper level divergence that pumped mass away from the typhoon. The inner end of a rainband wrapped part of the way around the core of Typhoon Chanthu. Concentric eyewalls might be developing, which would indicate the start of an eyewall replacement cycle.

The circulation around Typhoon Chanthu was small. Winds to typhoon force extended out 20 miles (30 km) from the center of Chanthu. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Chanthu was 35.0. The Hurricane Size Index (HSI) was 7.1 and the Hurricane Wind Intensity Size Index (HWISI) was 42.1. Typhoon Chanthu was capable of causing localized catastrophic damage.

Typhoon Chanthu will move through an environment capable of maintaining a strong typhoon during the next 48 hours. Chanthu will move over water where the Sea Surface Temperature is near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. If an eyewall replacement cycle occurs, Typhoon Chanthu will weaken when the inner eyewall weakens. An eyewall replacement cycle would increase the size of the circulation around Chanthu when the outer eyewall forms.

Typhoon Chanthu will move south of a high pressure system over the Western North Pacific Ocean. The high will steer Chanthu toward the west during the next several days. On its anticipated track Typhoon Chanthu could approach northeastern Luzon in 48 hours. Chanthu will likely still be a powerful typhoon when it approaches Luzon.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Conson continued to bring wind and rain to parts of Luzon. At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Conson was located at latitude 14.3°N and longitude 120.5°E which put it about 35 miles (55 km) south-southwest of Manila, Philippines. Conson was moving toward the northwest 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 988 mb.

Typhoon Chanthu Rapidly Intensifies to Equivalent of Major Hurricane

Typhoon Chanthu rapidly intensified to the equivalent of a major hurricane over the Western North Pacific Ocean on Tuesday. At 5:00 p.m. EDT on Tuesday the center of Typhoon Chanthu was located at latitude 16.3°N and longitude 133.0°E which put it about 915 miles (1475 km) east-southeast of Taiwan. Chanthu was moving toward the west at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 175 m.p.h. (280 km/h). The minimum surface pressure was 929 mb.

Former Tropical Storm Chanthu rapidly intensified from a minimal tropical storm to the equivalent of a major hurricane during the past 24 hours. A small eye quickly developed at the center of Typhoon Chanthu. 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 Chanthu. Storms near the core generated strong upper level divergence that pumped mass away from the typhoon.

The circulation around Typhoon Chanthu was small. Winds to typhoon force extended out 20 miles (30 km) from the center of Chanthu. Winds to tropical storm force extended out 85 miles (135 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Chanthu was 30.0. The Hurricane Size Index (HSI) was 7.4 and the Hurricane Wind Intensity Size Index (HWISI) was 37.4. Typhoon Chanthu was capable of causing localized severe damage.

Typhoon Chanthu will move through an environment favorable for intensification during the next 24 hours. Chanthu will move over water where the Sea Surface Temperature is near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Chanthu could continue to intensify during the next 24 hours and there is a chance it could strengthen to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.

Typhoon Chanthu will move south of a high pressure system over the Western North Pacific Ocean. The high will steer Chanthu toward the west during the next several days. On its anticipated track Typhoon Chanthu could approach northeastern Luzon in 60 hours. Chanthu could be near Taiwan in less than four days.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Conson brought wind and rain to Luzon. At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Conson was located at latitude 13.5°N and longitude 121.7°E which put it about 110 miles (175 km) southeast of Manila, Philippines. Conson was moving toward the west-northwest at 9 m.p.h. (15 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 988 mb.

Bermuda Issues Tropical Storm Watch for Potential Effects of Hurricane Larry

Bermuda issued a Tropical Storm Watch on Tuesday because of the potential effects of Hurricane Larry. At 2:00 p.m. EDT on Tuesday the center of Hurricane Larry was located at latitude 24.8°N and longitude 55.8°W which put it about 750 miles (1210 km) southeast of Bermuda. Larry was moving toward the northwest at 9 m.p.h. (13 km/h). The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 135 m.p.h. (225 km/h). The minimum surface pressure was 967 mb.

A Tropical Storm Watch was issued for Bermuda.

Hurricane Larry remained a large, powerful hurricane even though it was slowly weakening. A large eye with a diameter of 60 miles (95 km) was at the center of Larry. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. Winds to hurricane force extended out 60 miles (95 km) from the center of Larry. Winds to tropical storm force extended out 165 miles (265 km) from the center of circulation. The Hurricane Intensity Index (HII) for Hurricane Larry was 20.6. The Hurricane Size Index (HSI) was 22.4 and the Hurricane Wind Intensity Size Index (HWISI) was 43.0.

Hurricane Larry will move through an environment that is slightly unfavorable for intensification during the next 36 hours. The large circulation around Larry seems to have mixed cooler water to the surface of the Atlantic Ocean. Since the circulation is so large, when the winds mix cooler water on the northern side of Hurricane Larry eventually the core of the hurricane will move over that cooler water. Larry will likely be unable to extract enough energy from the ocean to maintain its full circulation. Hurricane Larry will move through a region where the upper level winds are weak and there is little vertical wind shear. Since there will be little vertical wind shear, Hurricane Larry is likely to weaken gradually.

Hurricane Larry will move around the western end of a subtropical high pressure system over the Atlantic Ocean. The high will steer Larry toward the northwest during the next 36 hours. On its anticipated track the center of Hurricane Larry will pass east of Bermuda on Thursday. The western side of Larry could bring tropical storm force winds to Bermuda.

Tropical Storm Conson Brings Wind and Rain to Central Philippines

Tropical Storm Conson brought wind and rain to the central Philippines on Monday. At 5:00 p.m. EDT on Monday the center of Tropical Storm Conson was located at latitude 11.7°N and longitude 124.6°E which put it about 50 miles (80 km) south-southeast of Calbayog, Philippines. Conson was moving toward the west-northwest at 12 m.p.h. (19 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 985 mb.

The center of Tropical Storm Conson made landfall on the east coast of Samar near Borongan on Monday. Conson was nearly a typhoon at the time of landfall. A small eye was visible at the center of Tropical Storm Conson on both radar and microwave satellite images. Conson produced gusty winds as it passed over Samar. Winds to tropical storm force extended out 45 miles (75 km) from the center of circulation. Tropical Storm Conson dropped heavy rain on Samar, Leyte, northern Cebu and northeastern Panay. Heavy rain could result in flash floods in some locations.

Tropical Storm Conson will move around the southern side of a high pressure system over the Western North Pacific Ocean. The high will steer Conson toward the northwest during the next 36 hours. On its anticipated track Tropical Storm Conson will pass over the Visayan Sea and the Sibuyan Sea. The center of Conson could pass over Masbate during the next 12 hours. Tropical Storm Conson could reach southern Luzon in a day or so. Conson could be be near Manila in 48 hours. Tropical Storm Conson will bring gusty winds and locally heavy rain to parts of Masbate, Mindoro and southern Luzon.

Tropical Storm Conson will move through an environment mostly favorable for intensification during the next 24 hours. Conson will move over water where the Sea Surface Temperature is near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Since the circulation around Tropical Storm Conson is small, it is likely to weaken each time the center passes over land. The intensity of Conson could fluctuate when it moves over islands and water surfaces.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 19W was organizing quickly and it appeared to be on the verge of strengthening to a tropical storm. At 5:00 p.m. EDT on Monday the center of Tropical Depression 19W was located at latitude 15.5°N and longitude 137.1°E which put it about 1170 miles (1890 km) east-southeast of Taiwan. The tropical depression was moving toward the northwest at 8 m.p.h. (13 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 1003 mb. Tropical Depression 19W is forecast to move toward the west-northwest and to intensify.

Tropical Storm Conson Develops Quickly near the Philippines

Tropical Storm Conson developed quickly near the Philippines on Monday morning. At 5:00 a.m. EDT on Monday the center of Tropical Storm Conson was located at latitude 11.0°N and longitude 126.6°E which put it about 120 miles (195 km) east-southeast of Dolores, Philippines. Conson was moving toward the west-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.

The circulation around Tropical Storm Conson organized quickly on Monday morning, The inner end of a primary rainband wrapped around the center of circulation. A small circular eye was at the center of Conson on microwave satellite images. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical storm. The circulation around Tropical Storm Conson was small. Winds to tropical storm force extended out 35 miles (55 km) from the center of Conson.

Tropical Storm Conson will move through an environment favorable for intensification during the next 12 hours. Conson will move over water where the Sea Surface Temperature is 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 Conson is likely to intensify during the next 12 hours and it could strengthen to a typhoon.

Tropical Storm Conson will move around the southern side of a high pressure system over the Western North Pacific Ocean. The high will steer Conson toward the northwest during the next 24 hours. On its anticipated track Tropical Storm Conson will reach northeastern Samar in 12 hours. Conson could be a typhoon when it reaches Samar. It will bring strong winds and locally heavy rain to Samar. Heavy rain could cause flash floods in some locations. Conson will weaken when the center passes over northeastern Samar. Since the circulation of Tropical Storm Conson is small, it could weaken quickly over land. The center of Tropical Storm Conson could move back over water when it moves north of Samar. The circulation could strengthen again when that happens. Conson could reach southeastern Luzon in a day or so.

Elsewhere over the Western North Pacific, Tropical Depression 19W formed north of Yap. At 5:00 a.m. EDT on Monday the center of Tropical Depression 19W was located at latitude 14.3°N and longitude 138.1°E which put it about 310 miles (500 km) north of Yap. The tropical depression was moving toward the north 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 1006 mb. Tropical Depression 19W is forecast to move toward the west-northwest and to strengthen.

Hurricane Larry Spins Southeast of Bermuda

Hurricane Larry was spinning southeast of Bermuda on Sunday afternoon. At 5:00 p.m. EDT on Sunday the center of Hurricane Larry was located at latitude 20.5°N and longitude 50.6°W which put it about 1195 miles (1925 km) southeast of Bermuda. Larry was moving toward the northwest at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 145 m.p.h. (235 km/h). The minimum surface pressure was 955 mb.

The circulation around Hurricane Larry continued to be symmetrical. A large eye was present at the center of Larry. A ring of strong 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 Hurricane Larry. Storms near the core generated upper level divergence that pumped mass away from the hurricane. The circulation around Larry was nearly in balance with the environment around the hurricane. The upper level divergence was pumping out as much mass as was being brought into Hurricane Larry by convergence in the lower levels. So, the minimum surface pressure was remaining nearly constant.

The circulation around Hurricane Larry increased in size. Winds to hurricane force extended out 45 miles (75 km) from the center of Larry. Winds to tropical storm force extended out 160 miles (260 km) from the center of circulation. The Hurricane Intensity Index (HII) for Hurricane Larry was 23.6. The Hurricane Size Index (HSI) was 16.3 and the Hurricane Wind Intensity Size Index (HWISI) was 39.9.

Hurricane Larry is likely to remain nearly in balance with its environment during the next 36 hours. Larry will move over water where the Sea Surface Temperature is near 28˚C. It will move around the eastern side of an upper level trough north of Puerto Rico. The upper level trough will produce southwesterly winds that will blow toward the top of Larry’s circulation. Those winds will cause some vertical wind shear, but the shear will not have a significant impact on Larry’s circulation. Hurricane Larry is likely to maintain its intensity during the next 36 hours.

Hurricane Larry will move around the southwestern side of a subtropical high pressure system over the Atlantic Ocean during the next 36 hours. The high pressure system will steer Larry toward the northwest during that time period. On its anticipated track Hurricane Larry will move in the general direction of Bermuda.

Hurricane Larry Intensifies to a Major Hurricane

Hurricane Larry intensified to a major hurricane on Friday evening. At 11:00 p.m. EDT on Friday the center of Hurricane Larry was located at latitude 15.5°N and longitude 43.3°W which put it about 1230 miles (1980 km) east of the Leeward Islands. Larry was moving toward the west-northwest at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 135 m.p.h. (220 km/h). The minimum surface pressure was 965 mb.

Hurricane Larry continued to intensify on Friday evening and the wind speed increased to that of a major hurricane. An eye with a diameter of 17 miles (28 km) was at the center of Hurricane Larry. The eye was surround be 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 Hurricane Larry. Storms near the core generated upper level divergence that pumped mass away from the hurricane in all directions. The removal of mass was causing the surface pressure to decrease.

The circulation around Hurricane Larry was becoming more symmetrical. Winds to hurricane force extended out 35 miles (55 km) from the center of Larry. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation. The Hurricane Intensity Index (HII) for Hurricane Larry was 20.6. The Hurricane Size Index (HSI) was 12.5 and the Hurricane Wind Intensity Size Index (HWISI) was 33.1.

Hurricane Larry will move through an environment favorable for intensification during the next 36 hours. Larry will move over water where the Sea Surface Temperature is near 28˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Hurricane Larry will continue to intensify during the next 36 hours. Larry is likely to strengthen to Category 4 on the Saffir-Simpson Scale during the weekend.

Hurricane Larry will move around the southern side of a subtropical high pressure system over the Atlantic Ocean during the next 36 hours. The high will steer Larry toward the west-northwest during that time period. On its anticipated track Hurricane Larry will move in the general direction of Bermuda.

Hurricane Larry Strengthens to Cat. 2

Hurricane Larry strengthened to Category 2 over the Atlantic Ocean on Friday afternoon. At 5:00 p.m. EDT on Friday the center of Hurricane Larry was located at latitude 15.0°N and longitude 42.0°W which put it about 1320 miles (2125 km) east of the Leeward Islands. Larry was moving toward the west-northwest at 16 m.p.h. (26 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 978 mb.

Hurricane Larry intensified to Category 2 on Friday afternoon. A small circular eye was present at the center of Larry. The eye was surround be 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 Hurricane Larry. Storms near the core generated upper level divergence that pumped mass away from the hurricane. Winds to hurricane force extended out 35 miles (55 km) from the center of Larry. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation.

Hurricane Larry will move through an environment favorable for intensification during the next 36 hours. Larry will move over water where the Sea Surface Temperature is near 28˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Hurricane Larry will intensify during the next 36 hours. Larry is likely to strengthen to a major hurricane during the weekend.

Hurricane Larry will move around the southern side of a subtropical high pressure system over the Atlantic Ocean during the next 36 hours. The high will steer Larry toward the west-northwest during that time period. On it anticipated track Hurricane Larry will move in the general direction of Bermuda.