Wednesday, September 17, 2008

Hurricane Intensity Scale...

For years I have always thought the Saffir-Simpson scale needs an overhaul!!! The scale ranks hurricanes by wind speed!!! This is not to say it doesn't try to equate for other things like surge and damage, but the actual scale ranks the hurricane by wind speed... Just look at Hurricane Ike which went down as a strong Cat-2... A Cat-2 is listed as 96-110mph winds... It suggest that the surge should be 6-8 feet... So there lies a HUGE problem in my opinion... With Ike the NHC was calling for surges above 20 feet.. That is actually according to Saffir-Simpson scale in the Cat-5 range which states:

Category Five Hurricane:
Winds greater than 155 mph (135 kt or 249 km/hr). Storm surge generally greater than 18 ft above normal. Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. All shrubs, trees, and signs blown down. Complete destruction of mobile homes. Severe and extensive window and door damage. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of all structures located less than 15 ft above sea level and within 500 yards of the shoreline. Massive evacuation of residential areas on low ground within 5-10 miles (8-16 km) of the shoreline may be required.

So to me since hurricanes are only ranked by wind speed we are misleading the public big time in my opinion... I give all the credit in the world to the NWS and the NHC for conveying the seriousness with Ike and the surge... The problem is the general public doesn't usually hear that seriousness and all they latch on to is the actual category... A 20 foot surge doesn't mean a whole lot when you say Ike is a Cat-2... I have talked to hundreds and hundreds of people over the years during hurricane chases and overwhelmingly the common theme is if the hurricane doesn't get to at least a Category-3 WERE NOT LEAVING... So to me it's long overdue especially when you look at a storm like Katrina... It went down as a Cat-3 but let's be real here, did that damage/impact look like a Cat-3 to you??? I was 5 miles inland in Gulfport, MS during Katrina and the surge made its way very close to us!!! I mean the 30 foot surge is off the charts in recorded US landfalling hurricanes! In my eyes Hurricane Katrina will always be a Cat-5 because that's what the people felt/experienced!!! CATASTROPHIC DAMAGE!!!

I don't know exactly how I'm going to go about this, and I also don't know all the exact details at this time, but it's long overdue for a new and improve hurricane scale... A scale that will incorporate all the deadly factors involved in a hurricane, not just wind speed... I mean every since I was a little kid and I could understand hurricanes, everyone always said the water is what kills you, not the wind... There is no doubt that it is true, so then why is the Saffir-Simpson scale rank hurricanes only by the wind speed???

Storm surge has to be taken into account! Also the size and duration of the storm has to be taken into account! If you have a 110mph Cat-2 the size of Texas moving 10mph, the damage is going to be worse and also extended much further out then lets say a 135mph Cat-4 the size of Arkansas moving at 20mph... Is the Cat-4 in this case really the stronger storm? I mean it may be for a very small area but when you look at the big picture it's not going to have near the affect as the huge slow moving strong Cat-2... I propose a scale that takes all of that into account...

I'm going to try my best over the next week or so to construct this scale... I want it to be as scientifically sounds as possible but at the same time easy for the general public to understand... I'm going to rank the winds, the surge, the size/speed, and maybe a few other important factors... After I fine tune this scale I'm going to go back and reclassify every hurricane I have ever chased... It will be interesting to be to see how my rankings compare to what history has it ranked... I have a feeling that Katrina will be at the top, while a small and extremely powerful hurricane like Charley may be a few notches down... Just some food for thought right now! First thing first, I have to construct the scale!!!

Before I go I just want to say something really quick with Hurricane Ike... It looks now that Ike will go down as the 3rd costliest hurricane of all time behind Hurricane Katrina and Andrew at 22 billion dollars... INCREDIBLE for only a Category-2!!! Also NOAA has posted some amazing imagery of the Texas and Louisiana coast after Ike... Check it out if you want to see some unbelievable images!!!

1 comment:

Rob Hart said...

I agree with you 100%. There are currently some whispers among the NWS that a new scale is needed...especially with everything that has happened this season. Well see what happens over the next few years!

*My comments/opinions are mine alone and aren't necessarily those of the DOC/NOAA/NWS.*