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Major Hurricane Irene live tracking


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I should point out that every single wobble at this point is significant. We're really "threading the needle" with Hispaniola, and a couple of good wobbles N could spell the difference between the cyclone getting totally shredded or skirting the N coast and surviving intact.

Given this, I will continue to monitor the wobbles and find them significant.

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Obviously it's going to wobble-- that goes without saying. Once can argue that the recent due-W motion is a wobble-- in which case, it's nice to see a correction the other way.

P.S. Ya meant "wary". We're not weary of it just yet-- only if it gets shredded. :D

haha god my spelling sucks.

While we are still on the point of wobbles though, the frictional effects actually might be something more significant than just the circulation bobbing back and forth... we saw a very similar effect with Jeanne when it came across Puerto Rico in 2004, as it quickly moved inland first over the island and then started tracking nearly due west once it reached the northern coastline as if wanted to go across the entire perimeter.

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haha god my spelling sucks.

While we are still on the point of wobbles though, the frictional effects actually might be something more significant than just the circulation bobbing back and forth... we saw a very similar effect with Jeanne when it came across Puerto Rico in 2004, as it quickly moved inland first over the island and then started tracking nearly due west once it reached the northern coastline as if wanted to go across the entire perimeter.

Either way, the wobbles are important at this point. (See my post above.)

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haha god my spelling sucks.

While we are still on the point of wobbles though, the frictional effects actually might be something more significant than just the circulation bobbing back and forth... we saw a very similar effect with Jeanne when it came across Puerto Rico in 2004, as it quickly moved inland first over the island and then started tracking nearly due west once it reached the northern coastline as if wanted to go across the entire perimeter.

This might be a bit off topic for this thread (or not?) but can you actually explain to me, or link me to some papers, that explain how and why the friction would affect the path of the cyclone in the way you described? I hope this isn't much simpler than I realize and apologize if it is a stupid question. I understand why friction would slow wind speeds (and increase gust speeds?) but not necessarily why it would "draw in" the storm... Thanks!

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Looks like they aren't upgrading it, despite the 78kt flight level winds, since they did an update, but no mention of an upgrade

TROPICAL STORM IRENE TROPICAL CYCLONE UPDATE

NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011

130 AM AST MON AUG 22 2011

AT APPROXIMATELY 125 AM AST...THE CENTER OF TROPICAL

STORM IRENE MAY LANDFALL ALONG THE EAST COAST OF

PUERTO RICO NEAR PUNTA SANTIAGO.

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Oh yea, I completely agree... we need Irene to gain about two degrees in latitude (from 18 to 20N) from now in order to clear Hispaniola. Lets set that has the target for now weight_lift.gif

Two degrees might be a tall order in that amount of time-- but the more, the better. It's nerve-wracking-- especially now that it actually has a core to mess up. (Twenty-four hours ago, it would hardly have made a difference-- now it does.)

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Looks like they aren't upgrading it, despite the 78kt flight level winds, since they did an update, but no mention of an upgrade

The FL winds were not supported by SMFR which was no higher than 55 knots in the same area. Not saying there weren't hurricane force winds in there somewhere, but it would have been better if the SFMR supported the FL winds.

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The FL winds were not supported by SMFR which was no higher than 55 knots in the same area. Not saying there weren't hurricane force winds in there somewhere, but it would have been better if the SFMR supported the FL winds.

Phil,

If this straddles the coast of Florida, won't land friction pull it inland? One track showed it parrallel almost the entire coast of Florida and I was wondering if that would be possible.

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Phil,

If this straddles the coast of Florida, won't land friction pull it inland? One track showed it parrallel almost the entire coast of Florida and I was wondering if that would be possible.

Florida has less friction than an island like PR or Hispaniola, though, because it has no mountains.

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This might be a bit off topic for this thread (or not?) but can you actually explain to me, or link me to some papers, that explain how and why the friction would affect the path of the cyclone in the way you described? I hope this isn't much simpler than I realize and apologize if it is a stupid question. I understand why friction would slow wind speeds (and increase gust speeds?) but not necessarily why it would "draw in" the storm... Thanks!

Here is a good paper on island effects on the propapgation of TCs

http://orca.rsmas.mi.../Wang_Chang.pdf

In this paper the basic idea is that there is a trough that is formed on the lee side of a mountain range, while a ridge develops on the windward side... in theory the TC would be drawn towards the trough causing the cyclone to move towards the island. That explains why you often see TCs trying to hang around land, because the leeward trough that forms will shift depending on the orientation of the wind direction.

Furthermore... if the mountains are tall enough, the llc is impeded by the height of the mountains and is essentially stuck... in this case the lee trough that forms on the lee side of the mountain range ends up developing into the new llc for the cyclone. When the upper level portion of the circulation (the part that is taller than the mountain) moves over the mountain pass, the llc circulation that forms from the lee trough reconnects with the upper level circulation and the cyclone can now progress in a more uniform fashion.

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I have a bad feeling this is going to miss Hispaniola entirely.. Irene is going to be on water in a couple of hours, it just clipped the eastern side of Puerto Rico. If this NW motion continues, I'm afraid my first statement is true.

A couple of hours ago we were talking about it just skimming the southern side of Puerto Rico. Now look.

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Here is a good paper on island effects on the propapgation of TCs

http://orca.rsmas.mi.../Wang_Chang.pdf

In this paper the basic idea is that there is a trough that is formed on the lee side of a mountain range, while a ridge develops on the windward side... in theory the TC would be drawn towards the trough causing the cyclone to move towards the island. That explains why you often see TCs trying to hang around land, because the leeward trough that forms will shift depending on the orientation of the wind direction.

Furthermore... if the mountains are tall enough, the llc is impeded by the height of the mountains and is essentially stuck... in this case the lee trough that forms on the lee side of the mountain range ends up developing into the new llc for the cyclone. When the upper level portion of the circulation (the part that is taller than the mountain) moves over the pass, the llc circulation that forms from the lee trough reconnects with the upper level circulation and the cyclone can now progress in a more uniform fashion.

Perfect - thanks so much! I'll get to it... should make for good reading tomorrow given the current situation. :)

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Updated the radar loop, made it longer by collecting more frames and also slowed the speed a bit.

You can tell the latest movement.

The motion is definitely NW in the last few frames. If that continues then Irene should be back over water in a few hours. The land interaction also appears to be affecting the "eyewall" a bit as well.

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Perfect - thanks so much! I'll get to it... should make for good reading tomorrow given the current situation. :)

Yea, Puerto Rico is just the warm up... Hispaniola will be the real test bed to see if this theory holds water arrowheadsmiley.png

Technically though you saw it employed with Emily. The llc dissipated on the windward side of the Hispaniola because it couldn't clear the mountain chain. Unfortunately though for Emily's case, the mid-level circulation was quite detached from the llc so thus when land interaction got in the way, the mid-level circulation further detached to the point that it was impossible for the lee trough to redevelop into a tropical cyclone vortex.

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