More on Ike

I've been reading the archives of the weather blog called Weather Underground that I like to follow during the hurricane season. It's written by a guy who has a PhD in meterology, and he really knows his stuff when it comes to tropical weather. There's a link in the link bar to his website if you're interested in checking it out.

Here's what he had to say about Ike's on Saturday morning soon after the storm made landfall:

Hurricane Ike made a direct hit on Galveston, Texas this morning at 3 am EDT as a top-end Category 2 hurricane with 110 mph winds. Although only rated a Category 2 storm, Ike carried a storm surge characteristic of a Category 4 hurricane to shore. The destructive power of Ike's storm surge rated a 5.0 on a scale of 0 to 6 just before landfall, according to the experimental Integrated Kinetic Energy (IKE) product of NOAA's Hurricane Research Division. This is about the same destructive potential Katrina had at landfall.

Galveston is not destroyed

Although Ike caused heavy damage by flooding Galveston with a 12-foot storm surge, the city escaped destruction thanks to its 15.6-foot sea wall (the wall was built 17 feet high, but has since subsided about 2 feet). The surge was able to flow into Galveston Bay and flood the city from behind, but the wall prevented a head-on battering by the surge from the ocean side. Galveston was fortunate that Ike hit the city head-on, rather than just to the south. Ike's highest storm surge occurred about 50 miles to the northeast of Galveston, over a lightly-populated stretch of coast. Galveston was also lucky that Ike did not have another 12-24 hours over water. In the 12 hours prior to landfall, Ike's central pressure dropped 6 mb, and the storm began to rapidly organize and form a new eyewall. If Ike had had another 12-24 hours to complete this process, it would have been a Category 4 hurricane with 135-145 mph winds that likely would have destroyed Galveston. The GFDL model was consistently advertising this possibility, and it wasn't far off the mark. It was not clear to me until late last night that Ike would not destroy Galveston and kill thousands of people. Other hurricane scientists I conversed with yesterday were of the same opinion.

Ike's Winds

Houston Hobby Airport on the south side of town recorded winds of 75 mph, gusting to 92mph, at 6 am CDT today. The winds likely were higher, but the anemometer failed. The airport measured a central pressure of 960 mb as the eye passed just to the east. Houston Intercontinental Airport on the north side of town recorded top winds of 56 mph, gusting to 70 mph. Eagle Point on Galveston Bay, at the northern end of Texas City, recorded sustained winds of 68 mph, gusting to 87 mph, at 1:34 am CDT. Top winds measured at Galveston Pleasure Pier were 60 mph, and the station recorded a pressure of 952 mb as the eye of Ike passed over. Much higher winds undoubtedly occurred on Galveston Island and nearby coastal areas, but the anemometers failed before these winds were recorded. There were no weather stations there to record these peak winds. Category 2 winds undoubtedly occurred at the tops of Houston's skyscrapers, as well.