wxman57 wrote:My mother lived near the Mississippi coast for Katrina. She "only" got 2 ft of water in her house. I saw the devastation on the MS coast first-hand. Houses completely gone for blocks inland, wiped out by the surge, which, by the way, was only a Cat 3 surge. A Cat 3 storm can only produce a Cat 3 surge. Surge is not a function of SS category (the absolute peak wind in a storm), it's a function of wind field size. A small Cat 3 produces a much lower surge than an average-sized Cat 3, and a very large Cat 3 (like Katrina) produces a surge similar to what an average Cat 5 might produce, but it's still a Cat 3 surge because Katrina was a Cat 3.
As for Harvey (living in Houston), I can tell you that the area affected by the flood was WAY larger than the area of homes destroyed by Katrina's storm surge (and levee failure). Lots of very expensive homes, too (not New Orleans 9th ward-type homes). It'll take a while to get the final damage tally, but I think Harvey will exceed Katrina in today's dollars. That's not to say Katrina was "nothing". Both were terrible disasters.
Thanks for that post wxman57.
I've seen scientists and weathermen speculate that the strength and lift (?) the dome/surge of water got when Katrina peaked over the loop current with only a couple hundred miles to the coast and nowhere else for the water to the north/northeast of the storm to disburse is suspected to have contributed to the surge. I don't really understand fluid dynamics enough to know whether that meant height, force or whatever. And I think it's still an open question as to whether or not and how much the strength was part of the specific surge she generated on the MS Gulf Coast and into Lake Pontchartrain and the Rigolets. Obviously I trust what you're saying regarding the size of the storm. But it just seems to me that dynamics would play at least some part in that as well.
The Lower 9th Ward wasn't the only part of the city that had destroyed homes though. Those areas east and south of the Industrial Canal were pretty wiped out. But most of the rest of the city all the way to Lakeview, West End and into Old Metairie where I lived were mostly destroyed. It's different because everything isn't all broken smashed up. It just sits there and rots. And with the month it took for many of us with homes close to or in the city to even be able to get back inside our properties without boats, I think you saw the worst flooding could do because you just didn't have a chance to dry out. Including the coast, we had over a million damaged homes and I think probably 35-40% of those destroyed. Due to the duration, Harvey was a larger swath of population and areas that it affected. It's going to be interesting to keep up with the real statistics as they are tabulated.
