Tag Archives: HWISI

Hurricane Sally Makes Landfall Near Gulf Shores

The center of Hurricane Sally officially made landfall near Gulf Shores, Alabama on Wednesday morning.  At 6:00 a.m. EDT on Wednesday the center of Hurricane Sally was located at latitude 30.3°N and longitude 87.7°W which put it near Gulf Shores, Alabama.  Sally was moving toward the north-northeast at 3 m.p.h. (5 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 as 965 mb.

A Hurricane Warning was in effect from the Mississippi/Alabama border to the Okaloosa/Walton County line in Florida.  Tropical Storm Warnings were in effect for the portions of the coast from the Mouth of the Pearl River to the Mississippi/Alabama border and from the Okaloosa/Walton County Line to Indian Pass, Florida.

Hurricane Sally strengthened to Category 2 on the Saffir-Simpson Scale on Tuesday night as it ground its way slowly toward the Gulf Coast.  Winds to hurricane force extended out 40 miles (65 km) from the center of Sally.  Winds to tropical storm force extended out 130 miles (210 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Sally was 17.8.  The Hurricane Size Index (HSI) was 11.2 and the Hurricane Wind Intensity Size Index (HWISI) was 29.0.  Hurricane Sally was capable of causing regional serious damage.  The winds were pushing water toward the coast and a storm surge of 9 to 12 feet (3 to 4 meters) was possible.

Hurricane Sally will move slowly northeast across Northwest Florida and Southeast Alabama.  Sally will slowly weaken as it moves inland, but it will cause widespread power outages in those areas.  Since Hurricane Sally will move slowly, it will drop heavy rain.  Flash Flood Watches extend from the Gulf Coast to Georgia and North Carolina.

Elsewhere over the Atlantic Ocean, Teddy rapidly intensified into a Category 2 hurricane, Hurricane Paulette passes south of Newfoundland and Tropical Storm Vicky moved farther away from the Cabo Verde Islands.  At 5:00 a.m. EDT on Wednesday the center of Hurricane Teddy was located at latitude 15.4°N and longitude 49.0°W which put it about 820 miles (1315 km) east of the Lesser Antilles.  Teddy was moving toward the northwest at 12 m.p.h. (19 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 976 mb.

At 5:00 a.m. EDT on Wednesday the center of Hurricane Paulette was located at latitude 41.9°N and longitude 49.1°W which put it about 385 miles (620 km) south-southeast of Cape Race, Newfoundland.  Paulette was moving toward the east-northeast at 29 m.p.h. (46 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 966 mb.

At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Vicky was located at latitude 21.6°N and longitude 33.9°W which put the center about 755 miles (1215 km) west-northwest of the Cabo Verde Islands.  Vicky was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were ind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 1004 mb.

Hurricane Sally Grinds Slowly Toward the Gulf Coast

Hurricane Sally ground its way slowly toward the Gulf Coast on Monday night.  At 11:00 p.m. EDT on Monday the center of Hurricane Sally was located at latitude 28.9°N and longitude 87.6°W which put it about 90 miles (145 km) east of the Mouth of the Mississippi River.  Sally was moving toward the west-northwest at 3 m.p.h. (5 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 986 mb.

A Hurricane Warning was in effect for the portion of the coast from Grand Isle, Louisiana to Navarre,, Florida including New Orleans, Lake Pontchartrain and Lake Maurepas.  Tropical Storm Warnings were in effect for the portions of the coast from Morgan City, to Grand Isle, Louisiana and from Navarre to Indian Pass, Florida.

After intensifying rapidly earlier on Monday, Hurricane Sally exhibited a more steady state on Monday evening.  There was a circular eye with a diameter of 16 miles (26 km) at the center of Sally.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  There was a break in the south side of the ring.  The circulation of Hurricane Sally pulled some drier air around the southern side of the core.  The drier air may have contributed to the break in the eyewall.  Storms near the core generated upper level divergence which pumped mass away to the north and the east of the hurricane.

The circulation around Hurricane Sally was relatively small.  Winds to hurricane force extended out 45 miles (75 km) from the center of circulation in the northeastern quadrant of Sally.  Elsewhere, hurricane force winds were occurring mainly in the eyewall.  Winds to tropical storm force extended out 130 miles from the center of circulation.  The winds were weakest in the southwestern quadrant of the hurricane.  The Hurricane Intensity Index (HII) for Hurricane Sally was 16.5.  The Hurricane Size Index (HSI) was 9.5 and the Hurricane Wind Intensity Size Index (HWISI) was 27.0.  Sally was capable of causing localized serious damage.

Hurricane Sally will move through an environment mostly favorable for intensification during the next 12 hours.  Sally will move over water where the Sea Surface Temperature is near 30°C.  It will be in a region where the upper level winds are weak and there will be little vertical wind shear.  Two other factors could inhibit further intensification of Hurricane Sally.  The drier air in the southern part of the circulation could limit the development of thunderstorms in that part of Sally.  The fact that Hurricane Sally is moving slowly means that it could mix cooler water to the surface which might reduce the energy available to drive the hurricane.  Even with the two inhibiting factors, Sally could intensify again on Tuesday.

Hurricane Sally will move around the western end of a subtropical high pressure system during the next 36 hours.  The steering currents are weak in that region and Sally will move slowly.  The slow movement of Hurricane Sally near the Gulf Coast means that any slight wobbles could affect the location of landfall.  On its anticipated track Hurricane Sally could approach the coasts of Mississippi and Alabama on Tuesday night.  A wobble to the left could bring Sally ashore in southeastern Louisiana while a wobble to the right would bring it closer to Northwest Florida.

Hurricane Sally will bring strong winds to the coast of Mississippi and Alabama.  Where the winds blow water toward the coast, Hurricane Sally could cause a storm surge of up to 12 feet (4 meters).  Hurricane Sally could drop nearly a foot (0.3 m) of rain on parts of southern Mississippi and Alabama.  Flash Flood Watches have been issued for parts of southern Mississippi, Alabama and Northwest Florida.

Elsewhere, Hurricane Paulette was speeding away from Bermuda, and Tropical Storms Teddy and Vicky organized over the eastern Atlantic Ocean.  At 11:00 p.m. EDT on Monday the center of Hurricane Paulette was located at latitude 35.7°N and longitude 62.3°W which put it about 275 miles (440 km) north-northeast of Bermuda.  Paulette was moving toward the northeast at 17 m.p.h. (28 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 965 mb.

At 11:00 p.m. EDT on Monday the center of Tropical Storm Teddy was located at latitude 13.2°N and longitude 45.0°W which put it about 1100 miles (1770 km) east of the Lesser Antilles.  Teddy was moving toward the west at 13 m.p.h. (20 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 1002 mb.

At 11:00 p.m. EDT on Monday the center of Tropical Storm Vicky was located at latitude 19.5°N and longitude 29.9°W which put it about 455 miles (735 km) west-northwest of the Cabo Verde Islands.  Vicky was moving toward the mprthwest at 7 m.p.h. (11 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 1000 mb.

Typhoon Haishen Intensifies to Equivalent of Major Hurricane

Typhoon Haishen intensified to the equivalent of a major hurricane over the Western North Pacific Ocean on Thursday.  At 5:00 p.m. EDT on Thursday the center of Typhoon Haishen was located at latitude 21.4°N and longitude 135.4°E which put it about 405 miles (650 km) southeast of Minamidaitojima, Japan.  Haishen was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 145 m.p.h. (235 km/h) and there were wind gusts to 175 m.p.h. (280 km/h).  The minimum surface pressure was 938 mb.

Typhoon Haishen intensified rapidly on Thursday.  A circular eye became more visible on conventional satellite images.  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 Haishen.  Storms near the core generated strong upper level divergence which pumped mass away from the typhoon.

The circulation around Typhoon Haishen increased in size on Thursday.  Winds to typhoon force extended out 65 miles (105 km) from the center of circulation.  Winds to tropical storm force extended out 215 miles (315 km) from the center.  The Hurricane Intensity Index (HII) was 29.9.  The Hurricane Size Index (HSI) was 23.5 and the Hurricane Wind Intensity Size Index (HWISI) was 53.4.  Typhoon Haishen was capable of causing widespread significant damage.

Typhoon Haishen will move through an environment favorable for intensification during the next 24 hours.  Haishen 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 Haishen could strengthen to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.

Typhoon Haishen will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Typhoon Haishen toward the northwest during the next 36 hours.  Haishen will move more toward the north when it reaches the western end of the high pressure system.  On its anticipated track Typhoon Haishen could reach Minamidaitojima in about 36 hours.  Haishen could approach the northern Ryukyu Islands in about 48 hours.  Typhoon Haishen could hit South Korea in a little over three days.

Large Typhoon Maysak Churns Toward South Korea

Large, powerful Typhoon Maysak churned toward South Korea on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Typhoon Maysak was located at latitude 30.1°N and longitude 126.9°E which put it about 405 miles (655 km) south-southwest of Busan, South Korea.  Maysak was moving toward the north-northeast at 13 m.p.h. (20 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 932 mb.

Typhoon Maysak neared the completion of an eyewall replacement cycle on Tuesday which resulted in an increase in the size of the circulation.  The original inner eyewall had not quite dissipated, but low level convergence was focused on the much larger outer eyewall.  Winds to typhoon force extended out 90 miles (145 km) from the center of circulation.  Winds to tropical storm force extended out 240 miles (390 km) from the center of Maysak.

Typhoon Maysak was a large, dangerous tropical cyclone.  The Hurricane Intensity Index (HII) was 25.1.  The Hurricane Size Index (HSI) was 27.5 and the Hurricane Wind Intensity Size Index (HWISI) was 52.6.  Typhoon Maysak was capable of causing widespread major damage.

Since Typhoon Maysak was near the end of an eyewall replacement cycle, it will likely weaken slowly during the next 18 hours.  Maysak will move over water where the Sea Surface Temperature is near 28°C.  An upper level trough over eastern Asia will approach Typhoon Maysak on Wednesday.  The trough will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause more vertical wind shear and the shear will cause Typhoon Maysak to weaken more quickly.

Typhoon Maysak will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Maysak toward the north during the next 24 hours.  On its anticipated track the core of Typhoon Maysak is likely to pass west of Kyushu.  Maysak could reach South Korea in about 18 hours.  Typhoon Maysak could be the equivalent of a large, major hurricane when it gets to South Korea.  Maysak will produce very strong winds over South Korea.  It will also drop heavy rain and flash floods could occur.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Haishen strengthened south of Iwo To.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Haishen was located at latitude 20.1°N and longitude 142.8°E which put it about 340 miles (545 km) south-southeast of Iwo To.  Haishen was moving toward the west-southwest at 8 m.p.h. (13 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 1000 mb.  Tropical Storm Haishen is forecast to strengthen into a typhoon and it could move toward western Japan later this week.

Typhoon Maysak Brings Wind and Rain to the Ryukyu Islands

Typhoon Maysak brought winds and rain to the Ryukyu Islands on Monday.  At 11:00 p.m. EDT on Monday the center of Typhoon Maysak was located at latitude 27.5°N and longitude 126.5°E which put it about 110 miles (175 km) west-northwest of Kadena AFB, Okinawa.  Maysak was moving toward the north-northwest at 13 m.p.h. (20 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 932 mb.

The eye and eyewall of Typhoon Maysak passed west of Okinawa on Monday.  Rainbands on the eastern side of Maysak passed over Okinawa and some of the other southern Ryukyu Islands.  A weather station at Naha reported a sustained wind speed of 58 m.p.h. (93 km/h).  A station at Kitahari (Kumejima Airport), which was closer to the center of Typhoon Maysak reported a sustained wind speed of 89 m.p.h. (144 km/h).

Satellite and radar images suggest that concentric eyewalls may have formed at the core of Typhoon Maysak.  The inner eye had a diameter of 8 miles (13 km).  A much larger outer eye with a diameter of approximately 100 miles (160 km) surrounded the inner eye.  Bands of showers and thunderstorms were revolving around the large core of Maysak.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.

The circulation around Typhoon Maysak was large.  Winds to typhoon force extended out 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extended out 200 miles (320 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Maysak was 25.1.  The Hurricane Size Index (HSI) was 25.5 and the Hurricane Wind Intensity Size Index (HWISI).  Maysak was capable of causing widespread major damage.

Typhoon Maysak will move through an environment capable of supporting a strong typhoon during the next 24 hours, but it has likely reached its peak intensity.  The formation of concentric eyewalls normally results in a weaker, but larger tropical cyclone.  The wind speed will decrease when the inner eyewall dissipates.  When that occurs, the maximum wind speeds will occur in the larger outer eyewall.  Since Maysak will move over water where the Sea Surface Temperature is near 29°C, it will remain a typhoon for another 24 to 36 hours.

Typhoon Maysak will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Maysak toward the north during the next 36 hours.  On its anticipated track the center of Typhoon Maysak will pass west of Kyushu.  Typhoon Maysak could reach South Korea in 36 hours

Elsewhere over the Western North Pacific Ocean, Tropical Depression 11W was passing southeast of Iwo To.  At 11:00 p.m. EDT on Monday the center of Tropical Depression 11W was located at latitude 21.7°N and longitude 144.2°E which put it about 290 miles (470 km) southeast of Iwo To.  The depression was moving toward the west-southwest 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 1006 mb.

Typhoon Maysak Strengthens to Equivalent of Major Hurricane Near Okinawa

Typhoon Maysak strengthened to the equivalent of a major hurricane near Okinawa on Monday.  At 11:00 a.m. EDT on Monday the center of Typhoon Maysak was located at latitude 25.5°N and longitude 127.0°E which put it about 110 miles (180 km) south-southwest of Kadena AFB, Okinawa.  Maysak was moving toward the north-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 936 mb.

Typhoon Maysak strengthened to the equivalent of a major hurricane on Monday as it approached Okinawa.  A circular eye with a diameter of 30 miles (50 km) was at the center of Maysak.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Maysak.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.

Typhoon Maysak had a large circulation.  Winds to typhoon force extended out 70 miles (110 km) from the center of Maysak.  Winds to tropical storm force extended out 200 miles (320 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Maysak was 23.6.  The Hurricane Size Index (HSI) was 24.1 and the Hurricane Wind Intensity Size Index (HWISI) was 47.7.  Typhoon Maysak was capable of causing widespread major damage.

Typhoon Maysak will move through an environment favorable for intensification during the next 12 to 24 hours.  Maysak 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 Maysak could strengthen further and it could intensify into the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.

Typhoon Maysak will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Maysak toward the north during the next several days.  On its anticipated track the center of Typhoon Maysak will pass west of Okinawa during the next few hours.  Maysak will bring strong winds and heavy rain to Okinawa.  Typhoon Maysak could approach South Korea in about 48 hours.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 11W formed east-southeast of Iwo To.  At 11:00 a.m. EDT on Monday the center of Tropical Depression 11W was located at latitude 25.5°N and longitude 127.0°E which put it about 315 miles (515 km) east-southeast of Iwo To.  the depression was moving toward the southwest at 14 m.p.h. (22 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 1008 mb.

Hurricane Laura Intensifies to Cat. 4

Hurricane Laura rapidly intensified to Category 4 on the Saffir-Simpson Scale on Wednesday.  At 2:00 p.m. EDT on Wednesday the center of Hurricane Laura was located at latitude 27.3°N and longitude 92.5°W which put it about 200 miles (320 km) south-southeast of Lake Charles, Louisiana.  Laura was moving toward the northwest at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 170 m.p.h. (275 km/h).  The minimum surface pressure was 952 mb.

A Hurricane Warning was in effect for the portion of the coast from San Luis, Pass, Texas to Intracoastal City, Lousiana.  Tropical Storm Warnings were in effect for the portions of the coast from Sargent, Texas to San Luis Pass and from Intracoastal City to the Mouth of the Mississippi River.

Hurricane Laura continued to intensify rapidly on Wednesday morning.  The eye became more circular and well defined.  The ring of thunderstorms around the eye strengthened and the highest wind speeds were occurring in that ring of storms.   Storms near the core of Laura generated strong upper level divergence which pumped large quantities of mass away from the hurricane.  The continued removal of mass allowed a further rapid decrease in surface pressure.

Hurricane Laura grew into a large hurricane on Wednesday.  Winds to hurricane force extended out 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center of Laura.  The Hurricane Intensity Index (HII) for Hurricane Laura was 28.3.  The Hurricane Size Index (HSI) was 19.1 and the Hurricane Wind Intensity Size Index (HWISI) was 47.4.  Hurricane Laura was capable of causing widespread significant damage.

Hurricane Laura could strengthen during the next few hours.  Laura will move over water where the Sea Surface Temperature is near 30°C.  There is a possibility that Hurricane Laura could intensify to Category 5 on the Saffir-Simpson Scale.  When Hurricane Laura nears the coast of western Louisiana, it will be closer to an upper level trough over Texas and Oklahoma.  The trough will produce southwesterly winds which will blow toward the top of Laura.  Those winds will cause the vertical wind shear to increase and that could stop the intensification of Hurricane Laura.

Hurricane Laura will move around the western end of a subtropical high pressure system that extends from the Atlantic Ocean over the Gulf of Mexico.  Laura will start to move towards the north when it reaches the western end of the high.  On its anticipated track Hurricane Laura will make landfall south of Lake Charles, Louisiana in 8 to 10 hours.  After it makes landfall, Laura will move north over western Louisiana.

Hurricane Laura is a strong, extremely dangerous hurricane.  It is capable of causing widespread significant damage.  Laura will be stronger than Hurricane Rita was when Rita hit the same area in 2005.  Hurricane Laura will cause a storm surge of 15 to 20 feet (5 to 7 meters) near and to the east of where the center makes landfall.  Large sections of the southwest coast of Louisiana south of Interstate 10 will go underwater.  Hurricane Laura will bring hurricane force winds to much of western Louisiana and to extreme east Texas.  Widespread power outages are likely.  Hurricane Laura will drop heavy rain over parts of western Louisiana, eastern Texas and Arkansas.  Flash floods could result from the heavy rain

Hurricane Laura Rapidly Intensifies into a Major Hurricane

Hurricane Laura rapidly intensified into a major hurricane during the overnight hours.  At 8:00 a.m. EDT on Wednesday the center of Hurricane Laura was located at latitude 26.4°N and longitude 91.4°W which put it about 280 miles (450 km) south-southeast of Lake Charles, Louisiana.  Laura was moving toward the northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 140 m.p.h. (225 km/h).  The minimum surface pressure was 963 mb.

A Hurricane Warning was in effect for the portion of the coast from San Luis, Pass, Texas to Intracoastal City, Lousiana.  Tropical Storm Warnings were in effect for the portions of the coast from Sargent, Texas to San Luis Pass and from Intracoastal City to the Mouth of the Mississippi River.

Hurricane Laura strengthened rapidly over the warm water in the Central Gulf of Mexico during the overnight hours.  An eye with a diameter of 30 miles (50 km) formed at the center of Laura.  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 Laura.   Storms near the core were generating strong upper level divergence which was pumping large quantities of mass away from the hurricane in all directions.  The removal of mass allowed the surface pressure to decrease quickly, which caused Laura to rapidly intensify.

The size of the circulation around Hurricane Laura also increased during the overnight hours.  Winds to hurricane force extended out 70 miles (110 km) from the center of circulation).  Winds to tropical storm force extended out 175 miles (280 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Laura was 20.6.  The Hurricane Size Index (HSI) was 19.1 and the Hurricane Wind Intensity Size Index (HWISI) was 39.7.  Hurricane Laura was capable of causing widespread major damage.

Hurricane Laura will continue to move through an environment favorable for intensification today.  Laura 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 little vertical wind shear.  Hurricane Laura could strengthen to Category 4 on the Saffir-Simpson Scale.  When Hurricane Laura approaches the coast it will get closer to an upper level trough over Texas and Oklahoma.  The trough will produce southwesterly winds which will blow toward the top of Laura.  Those winds will cause some vertical wind shear and Hurricane Laura could start to weaken just before it makes landfall.

Hurricane Laura will move around the western end of a subtropical high pressure system that extends from the Atlantic Ocean over the Gulf of Mexico.  Laura will move toward the north-northwest as it approaches the western end of the high.  On its anticipated track Hurricane Laura will make landfall near the border between Louisiana and Texas tonight.

Hurricane Laura will be capable of causing major damage over western Louisiana and eastern Texas.  Strong winds could cause widespread power outages.  Wind blowing water toward the coast will cause a storm surge of 10 to 15 feet (3 to 5 meters) near and to the east of where the center makes landfall.  Laura will drop locally heavy rain when it moves inland and flash floods could occur in some locations.

The wind speed in Hurricane Laura will be similar to the winds in Hurricane Harvey when Harvery made landfall on the coast of Texas in 2017.  Laura will be bigger than Harvey was.  The winds in Hurricane Laura could be stronger than the winds were in Hurricane Rita when Rita hit the same area in 2005.  However, Rita had intensified to Category 5 on the Saffir-Simpson Scale, but it was weakening when it made landfall.  Laura will not be as big as Rita was in 2005.

Hurricane Laura Strengthens over Central Gulf of Mexico

Hurricane Laura strengthened over the central Gulf of Mexico on Tuesday night.  At 11:00 p.m. EDT on Tuesday the center of Hurricane Laura was located 25.2°N and longitude 89.5°W which put it about 405 miles (655 km) southeast of Lake Charles, Louisiana.  Laura was moving toward the west-northwest at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 110 m.p.h. (175 km/h).  The minimum surface pressure was 978 mb.

A Hurricane Warning was in effect for the portion of the coast from San Luis Pass, Texas to Intracoastal City, Louisana.  Tropical Storm Warnings were in effect for the portions of the coast from Sargent to San Luis Pass, Texas and from Intracoastal City, Louisiana to the Mouth of the Mississippi River.  A Tropical Storm Warning was also in effect for Houston, Texas.

Hurricane Laura intensified over the warm water in the central Gulf of Mexico on Tuesday night.  An eye was visible intermittently on satellite imagery.  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 Hurricane Laura.  Storms near the core generated upper level divergence which pumped mass away from the hurricane.  The removal of large quantities of mass was causing the pressure to decrease more rapidly.

The area of Laura with hurricane force winds expanded on Tuesday night.  Hurricane force winds extended out 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center.  The Hurricane Intensity Index (HII) for Hurricane Laura was 13.9.  The Hurricane Size Index (HSI) was 13.7 and the Hurricane Wind Intensity Size Index (HWISI) was 27.6.

Hurricane Laura will move through an environment favorable for intensification on Wednesday.  Laura 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.  Hurricane Laura will strengthen on Wednesday and it could intensify rapidly.  Laura will strengthen into a major hurricane and it could reach Category 4 on the Saffir-Simpson Scale.

Hurricane Laura will move around the western end of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Laura toward the northwest during the next 12 to 18 hours.  The hurricane will turn toward the north when it reaches the western end of the high.  On its anticipated track Hurricane Laura will landfall near the border between Louisiana and Texas on Wednesday night.

Hurricane Laura will be a major hurricane when it makes landfall.  It will be capable of causing regional major wind damage.  Hurricane Laura will also cause a storm surge of 10 to 15 feet (3 to 5 meters) near and to the east of where the center makes landfall.  Locally heavy rain could cause flash floods in parts of east Texas and Louisiana when Hurricane Laura moves inland.

Typhoon Bavi Passes East of Shanghai

Typhoon Bavi passed east of Shanghai on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Typhoon Bavi was located at latitude 31.9°N and longitude 124.7°E which put it about 200 miles (320 km) east-northeast of Shanghai, China.  Bavi was moving toward the north-northwest at 9 m.p.h. (15 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 958 mb.

The circulation around Typhoon Bavi was well organized on Tuesday.  A circular eye with a diameter of 18 miles (30 km) was at the center of Bavi.  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 Typhoon Bavi.  Storm near the core generated upper level divergence which pumped mass away to the north of the typhoon.

The circulation around Typhoon Bavi was moderately large.  Winds to typhoon force extended out 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) for Bavi was 19.2.  The Hurricane Size Index (HSI) was 16.0 and the Hurricane Wind Intensity Size Index (HWISI) was 35.2.  Typhoon Bavi was capable of causing regional serious damage.

Typhoon Bavi will move through an environment favorable for intensification during the next 12 hours.  Bavi 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 Bavi could strengthen into the equivalent of a major hurricane during the next 12 hours.  In 12 hours Bavi will start to move over cooler water, which could end the chance for intensification.  In 24 hours Typhoon Bavi will approach the eastern part of an upper level trough over China.  The trough will produce strong southwesterly winds which will cause strong vertical wind shear.  The strong shear will cause Bavi to weaken more quickly.

Typhoon Bavi will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Bavi toward the north during the next 36 hours.  On its anticipated track Typhoon Bavi could approach the west coast of North Korea in about 24 hours.  Bavi will bring strong winds and locally heavy rain to North Korea and parts of northeastern China.