Almost 7 years to the date of the most devastating and costliest storm to strike the United States mainland, a second monster storm has made landfall very close to New Orleans, Louisiana.
Hurricane Katrina was directly responsible for 1,833 confirmed deaths and over 108 billion dollars in damage when it made landfall as a category 3 hurricane on August 23, 2005. Now, hurricane Isaac has made its way from the Atlantic Ocean to the Gulf of Mexico and targeted the Louisiana coast again – this time with category 1 strength.
As a reminder, here’s the enhanced satellite view of Katrina as it muscled up to category 5 strength just prior to making landfall as a category 3 storm:
A classic hurricane with a nearly perfect “eye”, producing hurricane force winds over a huge area from Florida nearly to Texas. Katrina was a category 5 storm at the time this image was produced.
By way of comparison, here’s an image of hurricane Isaac as it bore down on New Orleans as a category 1 hurricane:
Notice that a huge outer band of thunderstorms actually spun off of this hurricane and moved north, through Florida, and significantly reduced the overall impact of the storm post landfall.
In order to better understand the terminology associated with hurricanes, let’s review the conditions that identify a category 1 storm, for instance, with a category 5 storm.
The “Saffir-Simpson Scale” was created back in the 70s to give us a rule by which to accurately describe hurricanes.
Low pressure systems develop over warm ocean currents and their counter-clockwise rotation is fed by ocean waters. When the sustained winds generated by that rotation reach up to 38 miles per hour, the system is called a tropical depression. Once that wind speed reaches 39-73 miles per hour, the storm advances to tropical storm status and earns itself an official name.
Once that sustained wind speed reaches 74-95 miles per hour, it is a category 1 hurricane.
From 96-110 miles per hour, the storm has reached category 2 hurricane status.
From 111-129 miles per hour, it’s now a category 3 hurricane.
From 130-156 miles per hour, the storm is a category 4.
From 157-252 miles per hour, you have a category 5 hurricane.
Note: The maximum wind speed for hurricane Katrina was 175 miles per hour, which was sustained for at least one minute.
And now we have hurricane Isaac pounding the beleaguered “Big Easy”, as well as every parish in Louisiana’s southeast area.
Isaac is “only” a category 1 hurricane (locals dispute that designation and say Isaac was at least a category 2 hurricane), but its extremely slow movement is causing massive high-water issues because the system is spinning in place and dumping up to 20 inches of rain. Thankfully, as of this writing, no deaths have been attributed to Isaac, but there will be at least some before all is said and done. Damage won’t surpass the $108 billion caused by Katrina, but it will be extremely high – certainly in the billions of dollars.
For live, local coverage, I suggest FOX8 TV in New Orleans.
You can also glean excellent information from MyFoxHurricane.