Ike has Cat 4 Pressures....Cat 2 Winds....

[Junkdrawer]

How is that possible? The Weather Channel's Dr. Steve Lyons explained last night that Ike's wind field is so HUGE that the pressure gradients needed for Cat 4 winds are not there.

But the Cat 4 pressures WILL CAUSE RECORD STORM SURGES - AND STORM SURGE IS WHAT KILLS.

For years many in the hurricane forecasting community have been advocating a pressure-based categorization of hurricanes. Ike will be that camp's poster child.

THOSE THINKING YOU'RE FACING A CAT 2 STORM NEED TO THINK AGAIN. IKE WILL BE A KILLER.

[yardwork]

1. So it's the pressure, not the actual winds, that cause the storm surge?

[Junkdrawer]

2. Yes.

http://en.wikipedia.org/wiki/Storm_surge

[ProdigalJunkMail]

6. storm surge is caused primarily by winds...

not pressure...

sP

[Junkdrawer]

11. I stand corrected - sort of....

Both pressure and wind cause storm surge. And wind is normally the larger factor.

But Ike's extremely low pressure combined with the size of the wind field will make the storm surge much more devastating than the Cat 2 rating implies...

[ProdigalJunkMail]

12. no doubt!

people thinking of riding this out on Galveston are in for a rude, painful surprise!!!

Get out if you still can...

D

[Warpy]

10. Short answer, yes, caused by the low pressure at the center.

Think of that low air pressure as a vacuum hose. It sucks up a lens of water that can be 30 feet thick. As it moves across land, the center of the storm carries that lens of water with it. That's the storm surge.

Whatever wind the storm carries just whips the surface of that water into battering surf, but it's the depth of water that washes over barrier islands and beach houses, crushing them and leaving nothing but the concrete slab behind, if that.

Wind driven surf without a storm surge can devastate coastal areas, sure, but the total destruction accompanies the storm surge.

[yardwork]

18. Oh. You mean that there is like a plate of water lifted above the regular surface of the sea?

A lens of water 30 feet thick skims across the surface of the ocean, and when it meets land, it just keeps on going?

Yikes.

[ddeclue]

3. If the storm suddenly contracts it will accelerate the windfield

It's about conservation of momentum. If this storm suddenly contracts, look for the wind speeds to climb to match the pressure levels.

[Junkdrawer]

4. The ice skater effect....yes.. n/t

[screembloodymurder]

15. What would make it contract?

Is it the eye reconstruction?

[ddeclue]

31. I don't know.. I'd have to think about it..

but my best guess is that it has to do with the outflow from a hurricane.

Air sucked into the eye but there is an associated outflow with the hurricane where the air ends up going. I would suspect if there is a problem with the out flow the hurricane might not be as tight as it could be.

[ddeclue]

32. Eye IS contracting now as I suggested it might!

KHOU is reporting contracting eye, increasing winds!

[merwin]

5. I'm praying for those in Houston who decided to stick it out.

This could get ugly quick.

[AngryOldDem]

7. That's what the guy said on CNN just now.

If you make your decision to stay or go based on the category, you may be screwed.

I am amazed at the tide already along Galveston.

[Mari3333]

8. livelink

galveston is almost impassable..and its not even the surge yet..surfside is underwater..

and officials made one last attempt to get people out of galveston

http://abclocal.go.com/ktrk/feature?section=news/local&id=6102015

[Sabriel]

14. Is that working for you?

I get nothing but a blank screen every time.

[ancient_nomad]

17. You have to click the "PLAY" icon.....

bottom left of screen. I had the same problem til I clicked it. :-)

[Sabriel]

22. I did that. Nada. nt

[SammyWinstonJack]

9. And the debris already washing up. Piers have been destroyed.

[Aviation Pro]

13. The wind structure is problematic.....

....but the storm surge will reach epic proportions. As I've said, it's not the wind that kills it's the water.

[yardwork]

19. I've read that most deaths during hurricanes are due to drowning.

I think that this is hard for a lot of us to understand. I grew up in the midwest, and I still tend to think of hurricanes as big tornadoes. But hurricanes are not tornadoes. They're something else. That something else involves enormous amounts of water.

[NeedleCast]

16. Wind Speed Usually takes time to catch up to the pressure

As the pressure in a hurricane falls, the wind speed increases. However, if the pressure falls quickly, the wind speed increase can sometimes take hours to catch up. Or, said another way, pressure drop and wind speed increase don't occur simultaniously.

[jmowreader]

20. I'm more worried about the people toward the end of this storm's track

This thing is projected to turn, and as powerful as it is it will probably hit Arkansas as a strong Category 1-weak Category 2 hurricane...which will fuck Arkansas bad.

This isn't to say I'm not worried about the Gulf Coast. They're going to get severely nailed by this, but on the coast they tend to build strong enough to withstand hurricanes--not necessarily ones this bad (MAYBE a bank vault would survive this much windload, but I'm skeptical) but it's a consideration. In Arkansas? Probably not so much.

[NeedleCast]

21. Not a chance

It will be a weak tropical storm by then, at best.

[jmowreader]

23. You thinking, because of how far inland they are?

Fayetteville, where I live, is over 100 miles from the coast, and we got totally NAILED during Hurricanes Fran and Floyd. They can come in that far, and this storm is about as potent right now as Fran was.

[TexasLady]

24. another great link of live vid from Houston

http://www.maroonspoon.com/wx/ike.html

[malaise]

27. Thanks

Great link

Rick Perry's ass is grass if Houston takes a serious hit.

[jus_the_facts]

25. THAT'S REALLY ODD....this gif isn't the same one I copied/pasted...WTF?

....this latest map shows?! Louisiana...Mississippi and the Florida panhandle are now in IKE'S crosshairs. :scared:

[Commie Pinko Dirtbag]

26. I have only one thing to say.

This.

[guitar man]

28. I believe pressure

...is telltale of the overall intensity of the storm. I remember right before Katrina hit, I was talking to my dad on the phone.He was an old sailor and had rode through a couple typhoons aboard a heavy cruiser. I remember him saying "son, the pressure is down around 900mb, this is going to be a killer of a storm". He didn't say anything about the category of the storm, it was the barometric pressure that had him worried ,and he and my mom were in the path, about 50 miles inland from the MS gulf coast.

I wish he were still here to talk to...:(

[Wilber_Stool]

29. What about the

wind farms in Texas. Aren't they in the central part of the state? This is going to be a real test of their ability to stand excessive wind. Could cost them tens of millions.

[Junkdrawer]

30. Found this: Rated to 150 MPH Winds...

· What happens if there is a hurricane?

The wind turbines are rated to survive sustained winds of 150 MPH which is stronger than any storm that Nantucket Sound experienced in the 20th century.

http://www.capewind.org/FAQ-Category5-Cape+Wind%92s+Operations-Parent0-myfaq-yes.htm#32