Sunday, September 25, 2005

Katrina and Rita - Rare Events

In my spare time this weekend (during the pounding rain) I was contemplating what are the probabilities of having two Major hurricanes strike Louisiana back to back. The recent experience with Katrina and Rita represent two MAJOR hurricanes back to back to the same state. This is a very rare event. I have heard all kinds of reasons for this over the news the past weekend. Global warming seems to be getting quite a bit of attention. I am not buying the global warming. (A Major Hurricane is CAT 3 or above)

I was able to go to the NOAA website and find some historical data on hurricanes since 1851-2004 and have found out some interesting things.

1) Most events that are time driven occur according to a Poisson Distribution. So I assumed hurricanes are randomly generated according to this distribution. The average strikes per year to the US is 1.8

2) Next I used the data from the NOAA website and developed a frequency distribution for the Categories of Hurricanes.

3) Next I used the NOAA data and determined a frequency by State. It seems 60% of strikes will occur to Gulf Coast States of Florida, Texas, Louisiana, Alabama and Mississippi in that order of preference. The other 40% of strikes head for the Atlantic States.

Now comes the fun part – Monte Carlo simulation. At this point I used my Excel program in combination with a simulation program and I simulated or generated 10 million hurricane strikes by category and by state using the historical data from. Statisticians sometimes call this technique “bootstrap”. I kept track of the number of back to back strikes to Louisiana that were generated and the number of back to back MAJOR ( Category 3 or above) strikes to Louisiana.

The result was very interesting as I was able to come up with a probability distribution for back to back hurricane strikes in Louisiana and Major back to back hurricane strikes to Louisiana.

The mean probability was 0.00242. This translates into one Major back to back event for every 413 Hurricanes. This translates to 413/1.8 or 1 back to back event every 229 years. I had to massage this a little because some years cannot produce two US Hurricane strikes. The probability of two strikes is 0.536 so we take 229/0.536=427

So on average two MAJOR hurricanes will hit Louisiana back to back every 427 years. The 95% confident interval for the estimate falls within (330,640) years based on +/- (2) standard deviations of the bootstrap simulation.

Basically we had a 1 in 500 year event! Wow! No wonder the impact of what has happened.

I also did some testing to see if the last 20 years was increased vs. the time period from 1850-1900 and cannot conclude that there is a difference or increase in activity of strikes. Even the 6 strikes in 2004 is not outside the normal realm of possibility vs history for a single year. So the explanations of increased activity or global warming as a cause for this makes me want to see more evidence.

Friday, September 16, 2005

My Hat's Off

This will be my last rambling about Katrina. My Hat's Off to the mission coordinators and staff at Angel Flight America. These folks have been working long hours focusing on reuniting families and relocating people with relatives across the country. I finally will have a chance tomorrow to fly a mission taking a 54 year old gentleman from Baton Rouge to Dallas to be with his daughter. I don't have an official count but I think Angel Flight has flown over 1500 missions nation wide in support of Katrina Relief. Pilots from all over the country have volunteered their aircraft and fuel to help in this effort. Incidentally AVGAS is going for over $4 a gallon right now. We hear a lot about fire fighters, national guard and red cross relief workers. Angel Flight America has also provided a needed service and the staff and mission coordinators should really be commended for what they have done. Their work is behind the scenes and not very visible to the media and public, but they have done one heck of a job! For More Info check out or
Next I will get back to my LEAN/Six Sigma topics.

Tuesday, September 06, 2005

Katrina Update!

Hi, I spent two days volunteering for Angel Flight at the LSU PMAC/Fieldhouse Shelter. We are finding patients and evacuees to fly out of the area if they have a place to go. Looks like gas supplies are getting better. I have had some Angelflight Pilot guests at the house to house them. Last night we had a non Angel Flight pilot from Austin TX showup and take 9 people to LAX on his private jet. He has been flying missions for several days kind of on his own. Angel Flight has flown over 500 missions nationwide and also 150 in this area in support of Katrina response. I have met some amazing people that have come from all over the country to help out. It really gives you a lot of faith in human nature to see the generosity that people have. One brother/sister team came from Seattle Washington to help. Another man came from Georgia with a van to transport people. Another came from Colorodo. I met some Drs. and Nurses from FL. Angel Flight has set up a dispatch office at the Baton Rouge airport had has several volunteers manning and coordinating missions.
Fortunatly, I am back at work today. But will work tonight with them.

Friday, September 02, 2005

Hurricane Katrina

There has been a lot going on here and much more on the local news than on the national news about Baton Rouge. We have the influx of evacuees from New Orleans. Yesterday, Michael observed an 18 wheeler stop at a McDonalds. The back opened and about 50 people came out with all their belongings. There are displaced people in all the shopping parking lots and gas stations along the interstate. Most have no money and no place to go. There have been reports of violence but we have not seen any specifically. They did send a SWAT team to the BTR centroplex where the people are being sheltered. All government employees went home yesterday.

There are gas supply shortages. The refineries are slow in coming up and rail movements are bottlenecked because they must come through New Orleans at the Huey P Long bridge and this is all closed down. We are expecting long lines and prices to go up even higher. There was a 1/4 mile line at a station near our house yesterday. Supermarkets are also short supplied as a lot of deliveries came out of New Orleans.

The traffic in Baton Rouge is unbearable. Many people are housing relatives from New Orleans and there is excess traffic on the roads. Michaels roommate has his family in the apartment that we have for Michael near LSU. Laura was moving in to Tulane when the storm evacuation came out. It took us 6 hours to get out of the city and we had to leave all her belongings at the university. We now think the semester will be cancelled so today I am taking her to LSU to enroll her there.

BTR is also being used as a center for relief and we have government, homeland security and military vehicles on the road as well. Not to mention FoxNews and CNN have crews here in town.

It is a very interesting time we have right now so we all need to be careful here and hopefully it will get better. The evacuees are going to be enrolled in the public school system here as well and our infrastructure in BTR will be pushed to its limits. Michelle says that her work loads at the Physicians towers have picked up as the Womens Hospital here is already full and they are sending patients to the Physicians where she works. The PMAC on LSU campus has been set up as a Morgue and MASH type hospital.

In the end our troubles are minor, we have power, hot water, food and still able to work. So we should be able to make it though OK.