After rapidly strengthening as it passed across the Gulf of Mexico, Hurricane Laura has made landfall close to the Texas and Louisiana border. The category 4 storm is anticipated to unleash strong winds, heavy rains and a potentially catastrophic storm surge on an area that has not had a direct hit from a category 4 or 5 storm since the start of modern hurricane records.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite took a natural-colour image of Laura on midday local time yesterday as the storm approached the coast.
The science is still quite a way from understanding why some tropical cyclones undergo rapid intensification and others do not
The gravest concern was for a coastal zone extending from Texas’ Sea Rim State Park, to Louisiana’s Intracoastal City.
National Hurricane Center (NHC) forecasters warned this area will face a storm surge of 15 to 20ft (five to six metres) at the coast and flood waters that penetrate as far as 40 miles (60km) inland.
Storm surge occur when cyclonic winds from an approaching storm push a wall of extra water onto the shore.
Experts have issued unusually dire warnings about Hurricane Laura
Hurricane Laura: The storm is about to make landfall
The magnitude of a storm surge depends not only on a hurricane’s winds, but also on its speed, size and the angle at which it approaches the coast.
The timing of high and low tides can also affect the height of a surge.
Such storm surges are usually represent the greatest threat to life and property from a hurricane.
Hurricane Laura is also scheduled to deliver destructive winds and rain.
Hurricane Laura: he category 4 storm is anticipated to unleash strong winds and heavy rains
Forecasters anticipate hurricane-force winds will extend as far as 70 miles (100km) from the eye of the storm into eastern Texas and western Louisiana.
They expect rainfall totals of 13 to 25cm (five to 10 inches), with up to 15 inches in some areas — enough to trigger deadly flash floods.
The Visible Infrared Imaging Radiometer Suite (VIIRS) on NOAA-20 acquired the latest image of Hurricane Laura.
Clouds are shown in infrared using brightness temperature data, which is useful for distinguishing cooler cloud structures from the warmer surface below.
Hurricane Laura live: Devastating storm wreaks havoc in Louisiana [LIVE BLOG]
Hurricane Laura: ‘Unsurviable’ Cat 4 storm churning 150mph winds [INSIGHT]
Hurricane Laura: Satellite images capture ‘life-threatening storm’ [PICTURES]
That data is overlaid on composite imagery of city lights from NASA’s Black Marble dataset.
The map below shows sea surface temperatures (SSTs) around the US and Mexico as of August 25.
Water temperatures in the Gulf of Mexico were running approximately one degree Celsius above average.
SSTs above 27.8C are usually required to sustain and intensify hurricanes.
Hurricane Laura: The storm has not had a direct hit from a category 4 or 5 storm since the start of modern hurricane records
Hurricane Laura underwent a period of rapid intensification as it passed over the warm Gulf waters, with winds intensifying by 50mph (80kmh) over a 24-hour period.
NASA atmospheric scientist Gary Partyka revealed warm water is just one of several factors that contributes to rapid storm intensification.
He said: “Other things, like efficient outflow in the upper levels of a storm; whether the wind shear is low enough and the atmosphere is stable; and whether dry air is getting into the storm can be quite important as well.
“The science is still quite a way from understanding why some tropical cyclones undergo rapid intensification and others do not.”
One of the most troubling aspect of this storm is how many oil refining and petrochemical facilities lie in its path.
In anticipation of possible problems, NASA’s Applied Sciences Disasters team has been assembling datasets and imagery (based on optical and synthetic aperture radar sensors) from the days leading up to the storm.
NASA researcher Lori Schultz said: “We’ll use these to flag anomalous water extent and start assessing damage later in the week, when satellites again pass over after areas that the storm has hit.”