Saturday, August 18, 2007

The Hurricane Lantern


SOUTH PADRE ISLAND. Islanders began preparing for Hurricane Dean today with some plywood and shutters going up. For the third or fourth day straight, most models indicated the lower Texas and upper Mexico coast as the likely target after crossing the Yucatan Peninsula. So I started some preparations, had the truck looked at (what the heck is that noise?), and got ready for plywood duty.

While is seems inevitable that the hurricane would hit us squarely in the face, it should be said that Dean is several thousand miles away – 500 miles east of Puerto Rico. These storms get so large they basically make their own weather and go where they want to go, like the biggest Brahma bull in the barn. Even the experts say that predicting any tropical cyclone over 72 hours is highly uncertain to almost be meaningless (sorry, Town Emergency Team). Here’s why:

As indicated in the attached graphic at the top, an upper level low is circulating over Florida and the Bahamas. Since cyclones spin anti-clockwise, the upper low will prevent Dean from moving much to the north because of its spin that would push back on it. This low is predicted to remain about the same force and make a parallel track to the west, just like Dean. So no change in the upper level low in relation to Dean as they both move, Dean will continue marching a little north of due west.

Ah, but what happens is Dean slows or the upper low slows, or the upper low moves way in front of Dean? That could result in major changes to the forecast track. Indeed one of the best hurricane models called GDFL predicted that Dean would fall behind the upper low; due to the spinning action, Dean would be shot right to New Orleans like a circus clown out of a cannon.

What happens if Dean weakens over the Yucatan and the ULL collides with it, for some reason or other? This could result in a “super-cane” such as the move and the book, The Perfect Storm. Such a massive storm would probably be blown towards Florida by the subtropical jet. But we can only surmise and use the best current predictions we have. I’ll update this later tonight.

8 comments:

Joni Tanner said...

Very interesting Sam.

Sam said...

Hi Joni,

got the truck brakes fixed - the mechanic said that if I drove it to Austin no doubt it would have caught on fire! The rear "pumpkin" where the differential is located was dry for some reason, too. So I guess where a couple of steps closer in case we have to boogie.

P.S. just caught the 5:00 update and talked to the Mayor. The storm is projected now 125-150 miles south of us in Mexico. Great if is holds true. /sam

Anonymous said...

I have been reading your comments on the SPI Forum and your blog. I wish to applaud your insight and tenacity with regard to the issues. You really keep me informed and I thank you for that. Also, you are so humorous that it is a pleasure to look forward to what you have to say in a NON boring fashion. Thank you.

Sam said...

That is a kind thing to say and I appreciate it. But I'm no saint, such as the folks from the Bahamas who plan to fly over to Jamaica after Hurricane Dean strikes so as to set up computer and satellite communication networks ... there are real people doing fantastic things our there that should be complimented before me. But I hope the humor is disarming sometimes, so we can laugh off the small stuff and work on the things that really matter ... best to you, my friend.
sam

Anonymous said...

"P.S. just caught the 5:00 update and talked to the Mayor. The storm is projected now 125-150 miles south of us in Mexico. Great if is holds true."

Like you said this could change.I'm leaving from San Antonio Sun. morning. I have a condo down there through Wed. I am extremely nervous riding with my family. Are businesses shutting down? What's makes me nervous is a mass exudus off the Island. Thoughts?

Raul in S.A

beerman said...

Hey Sammy :)

I have been waiting for you to clue us in. We have had about 2" worth of the remnants of the tropical storm,OKC is getting pounded now. We are always thinking of ya'll,

Stay Safe Buddy!

Ken and Brenda T.

Sam said...

How Erin was able to maintain tropical-like structure over OK was truly remarkable, Beerman. I think it moved out of your area though, right? Get some fierce winds?

Beerman said...

No, at about 0300 Sunday we got a finger of rain, but like Jeff Masters said it looke like a "landcane" No real wind here.

Next Saturday is Hotter-N-Hell hundred and they are forecasting rain! I think we have onlt had a few days over 100, none through 7/31

Glad Dean is headed south!

Ken