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.