According to foreign media reports. Exactly 16 years after Hurricane Katrina made landfall, another major hurricane made landfall in southern Louisiana. At around noon on August 29 local time, Hurricane Ida made landfall near Port Fortune with a pressure of 930 millibars and sustained winds of 150 miles (240 kilometers) per hour.Initial reports indicate that it is the fifth largest hurricane (based on wind speed) ever to make landfall in the continental United States.

At 2:50 a.m. local time on August 30, the Visible Infrared Imaging Radiometer (VIIRS) array on the Suomi NPP satellite obtained a night view of Hurricane Ida. On the morning of August 29, the National Oceanic and Atmospheric Administration (NOAA) GOES-16 satellite obtained animated data for the “eye of a hurricane” approaching the coast.

In the last 24 hours before landing, the storm’s central pressure decreased from 985 millibar to 929 millibar, and wind speed increased from 85 to 150 miles per hour. According to the National Hurricane Center, when wind speeds increase by at least 35 mph in a 24-hour period, a storm experiences a “rapid increase.” Part of the increase is due to hot surface waters in the Gulf of Mexico in summer, which are around 30-31°C.

The animation above shows the development of the Ada wind field between August 27-30, 2021. The strongest winds are shown as bright yellow to white; And the most moderate winds are shades of bright orange and violet. The atmospheric data was powered by the Goddard Earth Observing System Model 5 (GEOS-5), a data ingestion model used by NASA scientists to analyze global weather phenomena. The GEOS model absorbs wind data from more than 30 sources, including ships, buoys, radio monitors, drip meters, aircraft, and satellites. The output of this model is performed on a 0.25 to 0.3 degree grid, so it may not be able to capture storm peaks and extreme conditions measured by a single instrument on the surface.

“For me, the most striking aspect of Hurricane Ida is its rapid intensification before landing,” said Scott Brown, a scientist at NASA’s Goddard Space Flight Center who specializes in hurricanes. “This storm is closely related to Opal and Katrina. Very severe hurricanes are similar in that they are They undergo rapid condensation in a region of deep warm water or vortex known as bay circulation.In addition to providing warm water as fuel, this vortex also prevents cold water from mixing with the surface.This type of cooling usually causes the storm to weaken, or at least cease to be strong. Both Opal and Katrina before making landfall, which reduced the impact of the storm to a certain extent, although it was still clearly bad. Hurricane Ida caused landfall. It really does happen.”

Hurricane Ida caused dangerous storm surges on the coasts of Louisiana and Mississippi. Weather stations and media reports indicated storms of 3 to 9 feet (1 to 3 meters) in Grande Island, Shell Beach, Lafitte, Barataria, Port Fortune and elsewhere. The Port of Fortune is a major commercial and industrial center in the United States, especially for oil and gas.

For most of August 29, the storm continued in southern Louisiana, bringing heavy rains that caused flooding before entering Mississippi and Alabama north and east on August 30. The slow pace of the storm could amplify the severe damage to the electricity and potable water infrastructure, while delaying the start of clean-up work. According to reports, by noon on August 30, there were blackouts for more than one million Louisiana households. Another 100,000 families in Mississippi have no electricity, and 12,000 in Alabama. The map above shows the distribution of outages collected by PowerOutage.US based on publicly available data sources.

“I am interested in the speed of Ada’s translation after landing,” said Su Hui, who studies hurricanes at NASA’s Jet Propulsion Laboratory. “There have been studies of how global warming causes tropical cyclones to slow down, which could lead to greater flooding and inundation. (For example, Hurricanes Harvey and Dorian.) Due to the quality of historical data, there is still debate. But climate model simulations show that the speed of The transmission of hurricanes will decrease with global warming.”