Everyone- Hurricane Isabel is still very dangerous

[rob8303]

I can't believe the posts I've been seeing. Compared to a monster category 5, Isabel sure doesn't look like much but if you look at the Saffir-Simpson scale, you will find this at the very least a strong category 3 or even weak category 4 hurricane and let's review what a strong cat 3/weak cat 4 can do:
Category Three Hurricane:
Winds 111-130 mph (96-113 kt or 178-209 km/hr). Storm surge generally 9-12 ft above normal. Some structural damage to small residences and utility buildings with a minor amount of curtainwall failures. Damage to shrubbery and trees with foliage blown off trees and large trees blown down. Mobile homes and poorly constructed signs are destroyed. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane. Flooding near the coast destroys smaller structures with larger structures damaged by battering from floating debris. Terrain continuously lower than 5 ft above mean sea level may be flooded inland 8 miles (13 km) or more. Evacuation of low-lying residences with several blocks of the shoreline may be required. Hurricanes Roxanne of 1995 and Fran of 1996 were Category Three hurricanes at landfall on the Yucatan Peninsula of Mexico and in North Carolina, respectively.


Category Four Hurricane:
Winds 131-155 mph (114-135 kt or 210-249 km/hr). Storm surge generally 13-18 ft above normal. More extensive curtainwall failures with some complete roof structure failures on small residences. Shrubs, trees, and all signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows. Low-lying escape routes may be cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of structures near the shore. Terrain lower than 10 ft above sea level may be flooded requiring massive evacuation of residential areas as far inland as 6 miles (10 km). Hurricane Luis of 1995 was a Category Four hurricane while moving over the Leeward Islands. Hurricanes Felix and Opal of 1995 also reached Category Four status at peak intensity.

from NHC website

This morning, CNN reported that even winds of 125 mph are devastating. It doesn't really matter how strong a storm is after that. Don't let your guard down. Isabel will not be a weak cat 1 with 75 mph at 5 pm. It will have winds of 135 MPH, REPEAT 135 MPH. DO NOT UNDERESTIMATE IT'S POWER.
BTW, I know most of you are not.

[Stephanie]

That is an excellent post rob! Very informative and a great reminder as to what we will be dealing with!

[rob8303]

That is an excellent post rob! Very informative and a great reminder as to what we will be dealing with!

Thanks Stephanie

[Deenac813]

Great post Rob.. you are so right.. just because she might not be a CAT4/5 does not meant that she is not VERY dangerous!

[abajan]

Isabel will not be a weak cat 1 with 75 mph at 5 pm. It will have winds of 135 MPH, REPEAT 135 MPH.

Well, as it turns out, those winds at 5:00 PM were just 125 mph.

[JetMaxx]

Well, I was in the eyewall of hurricane Frederic in 1979, and those 125 mph winds were pretty darn impressive to me...and very destructive.

If anyone doubts the damage a cat-3 is capable of, ask someone who survived Alicia, Elena, Opal, or Fran...or better yet, some folks on the outer banks tha survived hurricane Emily in 1993.
Emily was a "weak" cat-3 with 115 mph sustained winds and a central pressure of 961 mb.

Even though Cape Hatteras was in the west or "weak" eyewall, and the water depth was frightening....I saw some home video two guys shot from their second floor window at the height of the hurricane, and it was unbelievable....the waters from Pamlico Sound were covering the island (storm surge)...and this was barely a major hurricane...

Cape Hatteras and Nags Head are likely to experience far worse at landfall of Isabel...with IMO a stronger and much larger hurricane; and the projected track just to their SW means a tremendous storm surge from the Atlantic..

[azsnowman]

Now with Isabel being down graded, won't there still be a monster storm surge from when she was a Cat5??

Dennis

[Stephanie]

Now with Isabel being down graded, won't there still be a monster storm surge from when she was a Cat5??

Dennis

Storm surges are around 9 - 12 feet above normal for a Cat 3 Dennis.

[azsnowman]

Thanks Steph......let me clarify my question "LOL!" When she was a Cat5, I'm sure the swells were ENORMOUS needless to say, it takes at least a week for the swells to subside, now with the huge swells she made during her 5 period, those are still out there and heading inland, correct me if I'm wrong, now with Issy fixing to make landfall here in a few days, won't those swells make the storm surge even greater?? Please bear with me, I'm a landlubber "LOL!"

Dennis

[Stephanie]

Thanks Steph......let me clarify my question "LOL!" When she was a Cat5, I'm sure the swells were ENORMOUS needless to say, it takes at least a week for the swells to subside, now with the huge swells she made during her 5 period, those are still out there and heading inland, correct me if I'm wrong, now with Issy fixing to make landfall here in a few days, won't those swells make the storm surge even greater?? Please bear with me, I'm a landlubber "LOL!"

Dennis

Got me on that one Dennis. I don't know how long it takes for those original waves to dissipate, but I would think that by the time she makes landfall, there will be enough time inbetween her Cat 5 status and Cat 3(?) status for those larger waves to subside. Remember, she's still in the middle of the Atlantic - there's alot of water for her waves to travel.

Does any of our experts want to take a shot at this??

[azsnowman]

Le Bump!

Dennis

[JetMaxx]

The problem with the Outer Banks is they are less than 10' feet above sea level.

I'm forecasting a 940-945 mb hurricane at landfall...with sustained winds of 130-135 mph. That means a likely storm surge of 10-15' (and even higher if landfall occurs near high tide)...with wind waves 5-10' high on top of the storm surge...which will innundate those barrier islands....put them under water. :o

[wayoutfront]

sorry for so many questions on my first night
but how would that effect Morehead City (Cartaret County is only avg 12')

[ncbird]

I must agree with Rob. Although the grumpy Isabelle isn't the mighty cat 5 she once was, we should be takin her serious and not let our guard down.

I sit here in NC in her path as they have it projected now. I watch as she is quickly loosing her punch. But I have been through these things before. They have a mind of their own, and she still has allot of warm water to go over yet. And like Rob said, a cat 3 is nothing to sneeze about. Fran managed to crack a main support wall in my home and I watched as tree's flew through the air. And lets not forget, Eastern NC has had an unually wet season. Our ground is saturated, rivers are high, which means trees will be uprooted much easier. The one plus I can see to this hurricane is the forward speed, will mean less rain, so we won't have to deal with the flooding afterwards being such as those that occured with Floyd.

My hope is, Isabelle will back off and come in as a cat 1 or turn and go out to sea (not saying she will but I can always hope), but IMO no one should drop thier guard on her.

My moto is always
Pray for the best
Prepare for the worst
Stay safe

ncbird

[vbhoutex]

Thanks Steph......let me clarify my question "LOL!" When she was a Cat5, I'm sure the swells were ENORMOUS needless to say, it takes at least a week for the swells to subside, now with the huge swells she made during her 5 period, those are still out there and heading inland, correct me if I'm wrong, now with Issy fixing to make landfall here in a few days, won't those swells make the storm surge even greater?? Please bear with me, I'm a landlubber "LOL!"

Dennis

Dennis,

The storm surge is a dome of water that comes ashore just ahead of and to the right of the point of landfall mostly. It is litterally water pushed ahead of the storm by the winds. It is not the swells even though the swells or waves will be present also on top of that dome of water.

[AussieMark]

People forget quickly Floyd was a category 2 at landfall and look at all the damage and lives lost that Floyd caused.