Largest eye at landfall in the United States

[Derek Ortt]

marginal cat 3 (which I highly doubt Alica was... 100KT at 850mb does not equate to a cat 3 hurricane), may be the MPI for the northern GOM (barring QG enhancement of course). That may explain why weaker systems like Humberto and Cindy intensify up until landfall, but the more intense storms like Katrina weaken quickly

[CrazyC83]

My guess for Alicia is 90 kt, thinking the 100 kt was indeed flight level but the maximum winds were not measured.

[LSU2001]

Audrey looked pretty large and intense as she approached the Tx. La. coasts.
Tim

This wikipedia entry for Betsy sounds eerily familiar to the stories after Katrina.


Betsy also drove a storm surge into Lake Pontchartrain, just north of New Orleans, and the Mississippi River Gulf Outlet, a deep-water shipping channel to the east and south. Levees for the Mississippi River Gulf Outlet along Florida Avenue in the Lower Ninth Ward and on both sides of the Industrial Canal failed. The flood water reached the eaves of houses in some places and over some one story roofs in the Lower Ninth Ward. Some residents drowned in their attics trying to escape the rising waters.

These levee breaches flooded parts of Gentilly, the Upper Ninth Ward, and the Lower Ninth Ward of New Orleans as well as Arabi and Chalmette in neighboring St. Bernard Parish. President Lyndon Johnson visited the city, promising New Orleans Mayor Vic Schiro federal aid.

It was ten days or more before the water level in New Orleans went down enough for people to return to their homes. It took even longer than that to restore their flooded houses to a livable condition. Those who did not have family or friends with dry homes had to sleep in the shelters at night and forage for supplies during the day, while waiting for the federal government to provide emergency relief in the form of trailers.

In all, 164,000 homes were flooded at the second landfall.

Evidence suggests that cheap construction and poor maintenance of the structures led to the failure of the levees. However, popular rumor persists that they were intentionally breached, possibly as a means of salvaging the more prosperous French Quarter.[7] Similar rumors abound in the wake of Hurricane Katrina.

[Derek Ortt]

a recent study by Brian jarvinen showed that Audrey was a cat 1 hurricane at landfall (shows that ALL hurricanes must be taken very seriously). It has been posted here before

[Ed Mahmoud]

marginal cat 3 (which I highly doubt Alica was... 100KT at 850mb does not equate to a cat 3 hurricane), may be the MPI for the northern GOM (barring QG enhancement of course). That may explain why weaker systems like Humberto and Cindy intensify up until landfall, but the more intense storms like Katrina weaken quickly

I assume then (I don't actually know), a Cat 3 or Cat 4 storm like the famous 1900 Galveston storm was probably a Cat 5 in the Central Gulf?



Just another reason to live in Texas, I suppose.

[LSU2001]

a recent study by Brian jarvinen showed that Audrey was a cat 1 hurricane at landfall (shows that ALL hurricanes must be taken very seriously). It has been posted here before

Very, very interesting Derek, I have always heard about how horrible Audrey was and how it was a Cat. 4 at landfall. I read the part of the study on Audrey and WOW. If it was really a Cat 4 the disaster would have been much much worse. (it was bad enough as a Cat. 1) I really liked the part about how Audrey was like Katrina in that it had a large windfield and it was this that pushed the surge.

Just goes to show you can learn something new everyday

[Ed Mahmoud]

http://www.aoml.noaa.gov/hrd/Landsea/12Tides.pdf



Audrey only had Cat 1 winds, but a central pressure normally found in a Cat 3, and a larger than normal envelope of maximum winds. Hence a storm surge normally associated with higher winds.


Maybe somebody should create an "Enhanced Saffir-Simpson" scale that takes into account major hurricane type surge as well as wind and central pressure.

[CrazyC83]

marginal cat 3 (which I highly doubt Alica was... 100KT at 850mb does not equate to a cat 3 hurricane), may be the MPI for the northern GOM (barring QG enhancement of course). That may explain why weaker systems like Humberto and Cindy intensify up until landfall, but the more intense storms like Katrina weaken quickly

I assume then (I don't actually know), a Cat 3 or Cat 4 storm like the famous 1900 Galveston storm was probably a Cat 5 in the Central Gulf?



Just another reason to live in Texas, I suppose.

Some of them probably were. The Galveston storm (my guess for that is 110 kt at landfall) was probably about 130-135 kt at its peak (it could have been Cat 5 though), although some other notable storms like the Indianola hurricane were likely Cat 5 at peak intensity.

[Category 5]

a recent study by Brian jarvinen showed that Audrey was a cat 1 hurricane at landfall (shows that ALL hurricanes must be taken very seriously). It has been posted here before

I assume it just weakened rapidly before landfall correct?

[Ptarmigan]

a recent study by Brian jarvinen showed that Audrey was a cat 1 hurricane at landfall (shows that ALL hurricanes must be taken very seriously). It has been posted here before

Interesting. I read it was a Category 4. From the radar image I have seen, it was quite large.

[Ptarmigan]

Some of them probably were. The Galveston storm (my guess for that is 110 kt at landfall) was probably about 130-135 kt at its peak (it could have been Cat 5 though), although some other notable storms like the Indianola hurricane were likely Cat 5 at peak intensity.

I tend to think the Great Galveston Hurricane of 1900 was a large hurricane. I have read that the Indianola Hurricane hit Texas as a Category 5 hurricane. 1886 was a bad year for Texas in which four hurricanes affected the state, like what Florida went through in 2004.

[Ptarmigan]

\

Evidence suggests that cheap construction and poor maintenance of the structures led to the failure of the levees. However, popular rumor persists that they were intentionally breached, possibly as a means of salvaging the more prosperous French Quarter.[7] Similar rumors abound in the wake of Hurricane Katrina.

Same thing they said with the Great Mississippi Flood of 1927, when levees were bombed for the water to flow into St. Bernard Parish.

[Tampa Bay Hurricane]

Big Eyes= Big Surges if the windfield follows along the
Gulf Coast

[Derek Ortt]

http://www.aoml.noaa.gov/hrd/Landsea/12Tides.pdf

here is the link to the Jarvinen study that shows Audrey as a cat 1

[Ed Mahmoud]

http://www.aoml.noaa.gov/hrd/Landsea/12Tides.pdf



Audrey only had Cat 1 winds, but a central pressure normally found in a Cat 3, and a larger than normal envelope of maximum winds. Hence a storm surge normally associated with higher winds.


Maybe somebody should create an "Enhanced Saffir-Simpson" scale that takes into account major hurricane type surge as well as wind and central pressure.

Jinx...

[Category 5]

That report pretty much makes Audrey sound like a Katrina like storm, it's winds fell rapidly but the pressure rose more slowly. Resulting in a very abnormal Wind Speed/Pressure combination.

[CrazyC83]

Audrey looked pretty large and intense as she approached the Tx. La. coasts.
Tim

This wikipedia entry for Betsy sounds eerily familiar to the stories after Katrina.


Betsy also drove a storm surge into Lake Pontchartrain, just north of New Orleans, and the Mississippi River Gulf Outlet, a deep-water shipping channel to the east and south. Levees for the Mississippi River Gulf Outlet along Florida Avenue in the Lower Ninth Ward and on both sides of the Industrial Canal failed. The flood water reached the eaves of houses in some places and over some one story roofs in the Lower Ninth Ward. Some residents drowned in their attics trying to escape the rising waters.

These levee breaches flooded parts of Gentilly, the Upper Ninth Ward, and the Lower Ninth Ward of New Orleans as well as Arabi and Chalmette in neighboring St. Bernard Parish. President Lyndon Johnson visited the city, promising New Orleans Mayor Vic Schiro federal aid.

It was ten days or more before the water level in New Orleans went down enough for people to return to their homes. It took even longer than that to restore their flooded houses to a livable condition. Those who did not have family or friends with dry homes had to sleep in the shelters at night and forage for supplies during the day, while waiting for the federal government to provide emergency relief in the form of trailers.

In all, 164,000 homes were flooded at the second landfall.

Evidence suggests that cheap construction and poor maintenance of the structures led to the failure of the levees. However, popular rumor persists that they were intentionally breached, possibly as a means of salvaging the more prosperous French Quarter.[7] Similar rumors abound in the wake of Hurricane Katrina.

The eroded eastern eyewall makes me think Audrey was a weakening storm at landfall in the later stages of an ERC. My thinking is that the pressure was around 950mb at landfall (a blend of the data), so it was considerably weaker than Rita. My guess is 85 kt for the landfall intensity (and I think 100 kt was its peak intensity, even though the pressure was higher at about 958mb at that time - ERC's were enlarging the storm greatly).

[Derek Ortt]

That same Jarvinen study showed that the Galveston hurricnae was in deed a marginal cat 4 at landfall

[Recurve]

http://www.aoml.noaa.gov/hrd/Landsea/12Tides.pdf



Audrey only had Cat 1 winds, but a central pressure normally found in a Cat 3, and a larger than normal envelope of maximum winds. Hence a storm surge normally associated with higher winds.


Maybe somebody should create an "Enhanced Saffir-Simpson" scale that takes into account major hurricane type surge as well as wind and central pressure.

If I have it right, that's somewhat the direction Powell is going with the H*Wind analysis, tries to get a better handle on the windfield and assigns categories up to 6 in .1 increments. Sorry I don't have a link but it's on the AOML/HRD site I believe.

[richtrav]

The Texas coast, especially the southern part, has some pretty dry desert country to its west. I thought that was a big reason that Allen did not turn into an absolute disaster for the southern coast, it apparently sucked in enough air from the Mexican deserts to cripple it before landfall. That and the path most big hurricanes have to take to get to the southern coast generally involve crossing the Yucatan (though Beulah and Emily both crossed the Yucatan and redeveloped into Cat 3s anyways)