Laura rapidly intensified into a Category 4 hurricane on Wednesday after gaining strength from the warm Gulf of Mexico waters.
It is the first major hurricane of the 2020 Atlantic season and the National Hurricane Center (NHC) is warning of "potentially catastrophic storm surge, extreme winds and flash flooding along the northwest Gulf Coast."
"On the forecast track, Laura will approach the upper Texas and southwest Louisiana coasts this evening and move inland within that area tonight. The center of Laura is forecast to move over northwestern Louisiana tomorrow, across Arkansas Thursday night, and over the mid-Mississippi Valley on Friday," says the NHC.
Over 420,000 Texas residents and another 200,000 people in Louisiana were under mandatory evacuation orders on Wednesday, as reported by Reuters.
Hurricane Laura took aim at oil production platforms as it approached the coasts of Texas and Louisiana. Over 300 offshore oil facilities were evacuated and 84 per cent of U.S. Gulf of Mexico crude output was shutdown, as well as 61 per cent of the region’s offshore production.
The storm could bring as much as 250 mm or rainfall to parts of the U.S. Gulf Coast, with local amounts as high as 380 mm for some, and all falling on areas already somewhat waterlogged from Marco's impact. The rainfall will cause widespread flash and urban flooding, small streams to overflow their banks and minor to isolated moderate river flooding.
Just as dangerous will be the "unsurvivable" storm surge, which will be significant along the coastal areas, according to the NHC.
"Unsurvivable storm surge with large and destructive waves will cause catastrophic damage from Sea Rim State Park, Texas, to Intracoastal City, La., including Calcasieu and Sabine Lakes. This storm surge could penetrate up to 40 miles (64 kilometres) from the immediate coastline, and flood waters will not fully recede for several days after the storm," the NHC says.
Some areas in Louisiana could see it reaching as high as 20 feet (more than 6 metres). Parts of southeastern Texas coast may see a storm surge reaching 10-15 feet (3 to 4.57 metres).
One of the greatest threats to life and property from a hurricane is storm surge, which is when an abnormal rise of water is pushed to shore and is capable of causing extreme flooding in coastal areas.
Storm surge can result in storm tides exceeding 6 metres. At least 1,500 people lost their lives during Hurricane Katrina in 2005 and many of these fatalities were related to the direct and indirect impacts of storm surge.
As well, a few tornadoes are expected on Thursday across Louisiana, Arkansas, and western Mississippi.
Even after landfall, the storms' remnants are forecast to move deep into North America along the Mississippi Valley -- such that once it passes south of the Great Lakes, its moisture will likely fuel weekend showers in southern Ontario.
Though the longer-range forecast is a little bit less certain, there is a slight chance the storm's remnants may still be coherent enough to reform once it exits back out to sea off the U.S. northeastern coast, potentially impacting Atlantic Canada on the weekend.
HURRICANE LAURA SIZE COMPARISON
“Hurricane Laura is a fairly large hurricane, and as it approaches landfall, it contains a clear, wobbling eye over 40 kilometres in diameter. To put this size into perspective, the city of Brampton, Toronto, Mississauga, Vaughan and Scarborough would fit inside the clear eye,” explains The Weather Network meteorologist Tyler Hamilton.
“Hurricane-force winds extend outwards by 90 km from the centre of Hurricane Laura. Hypothetically, if the storm was over Toronto, Barrie would experience hurricane conditions. Tropical Storm-force winds extend over 300 km from the eye. In a similar hypothetical situation, tropical storm conditions would be felt in Ottawa.”
Keep an eye on the forecast as we continue to monitor this storm.