2004-09-03 FCST: Ivan (Atlantic)

[Jeff Snyder]

Just saw that update as well... Mind you, the 1730z report said central pressure was 923mb... So that's a fall of 9mb in 2 hours! This all while the hurricane is butting into some very dry air to its northwest...

 

[Robert Dewey]

Looks like the dry air is eating away at the northwestern edge as Jeff said... I would bet on possibly just west of the panhandle of FL as being the strike area - That trough rotating through the central US is looking pretty impressive, and will probably pervent Ivan from moving too far west.

With the increase in shear, somewhat cooler SSTs across the Gulf (compared to hurricanes current location), and statistics would all suggest the hurricane would most likely weaken, with my best guess calling for a CAT 3 by landfall.

 

[Jeff Snyder]

I still can't believe it'd strengthen too much more.. I mean, there is some very dry air to the northwest of the system, which is likely some of the cause for the storm to become more asymmetric. Additionally, there appears to be some shearing going on in the northwest quadrant of the storm. This can be seen by the fact that the outflow is moving cyclonically (not the typical anticyclonic motion) in that part of the cane...

 

[David Wolfson]

Next stop, Grand Cayman: http://www.caymanweather.metsite.com/WxFla...lash/redbay.htm
and http://www.weatherincayman.com/

 

[Robert Dewey]

Originally posted by David Wolfson
Next stop, Grand Cayman: http://www.caymanweather.metsite.com/WxFla...lash/redbay.htm
and http://www.weatherincayman.com/

Thanks for the link! That data updates every few seconds! Should be real interesting to watch...

 

[David Wolfson]

Yeah. Perhaps we should start a pool in EE as to when their station blows away....

 

[Tim Vasquez]

If the 1930Z extrapolated pressure of 914 mb is correct, then only five hurricanes have had a lower figure: Gilbert, Labor Day 1935, Allen, Mitch, and Camille. This is certainly big-league stuff.

Tim

 

[Shane Adams]

Originally posted by rdewey+--><div class='quotetop'>QUOTE(rdewey)</div>

<!--QuoteBegin-David Wolfson

Next stop, Grand Cayman: http://www.caymanweather.metsite.com/WxFla...lash/redbay.htm
and http://www.weatherincayman.com/

Thanks for the link! That data updates every few seconds! Should be real interesting to watch...[/b]

Not for me, I have to manually hit "refresh" and then it loads the entire page all over, so there's no "real-time" updates

 

[Bob Schafer]

Try out this visible shot (updated as new data gets posted):

http://wwwghcc.msfc.nasa.gov/cgi-bin/get-g...h=1000&zoom=1"

Oh, and the "Power 106" radio station in Jamaica is reporting that power is about to be restored, and for everyone to please disconnect their generators from their circuit breakers.

 

[Robert Dewey]

Originally posted by Chris Rozoff+--><div class='quotetop'>QUOTE(Chris Rozoff)</div>

Originally posted by Jeff Snyder+--><div class='quotetop'>QUOTE(Jeff Snyder)

I still can't believe it'd strengthen too much more.. I mean, there is some very dry air to the northwest of the system, which is likely some of the cause for the storm to become more asymmetric. .[/b]

Precipitable water from RAMSDIS experimental page doesn't really seem to bare this out. Yes, water vapor from GOES shows dry air, as it usually does in convectively inactive regions of the subtropics, but that, I believe, is somewhat misleading. The primary reason for the lack of signature in the water vapor to the storm's NW appears to be a disruption in the outflow of the hurricane. Nonetheless, the air is somewhat drier there aloft, no argument there. But I don't think this is unusual. The feature to its northwest and the building ridge to the storm's north, seems to be applying some shear on the storm. Shear will of course make the storm more susceptible to the dryer air aloft. Still, it is worth checking out the site:

http://www.cira.colostate.edu/ramm/rmsdsol/ROLEX.html

and glancing at the AMSU estimated precipitable water. This doesn't seem to suggest a terrifying environment of moisture for the storm to its NW. Actually, here's a downloaded picture: http://thunder.atmos.colostate.edu/~rozoff/29.gif

Best (and cheers to the renewed cat 5 status!),
Chris[/b]

Hmm... I started thinking about it again, and perhaps that 'dry' appearance is actually the descent of air around the edge of the hurricane (in combination with the shear that you suggested). All that rising air in the hurricane must sink somewhere (i.e. the eye and the area around the hurricane - near the ouflow). It will be real interesting though in the days to come with that trough/shortwave rotating southeastward across (over the central Plains right now), and it's effects on the hurricane.

Originally posted by Shane Adams
<!--QuoteBegin-rdewey

@
<!--QuoteBegin-David Wolfson

Next stop, Grand Cayman: http://www.caymanweather.metsite.com/WxFla...lash/redbay.htm
and http://www.weatherincayman.com/

Thanks for the link! That data updates every few seconds! Should be real interesting to watch...

Not for me, I have to manually hit "refresh" and then it loads the entire page all over, so there's no "real-time" updates[/quote]

That's odd. I'm using Win XP Home and MS Explorer... The page refreshes automatically.

 

[Amos Magliocco]

Have moved this post from another location.

Originally posted by D. Bailey
Before I say anything else about what I've seen according to some of the models concerning Ivan, a bit of an update.
Ivan is back up to Category 5 intensity, the winds are 155 mph.
The Caymans ate getting hit and The Western portion of Jamaica is in the portion of Ivan that has storms close to the eye.

The 96-hour 500 mb heights+MSLP GFS Model shows Ivan very close to the AL/FL Border. It looks like this will be where the eye may very well make landfall.
There are a couple of Trofs (http://www.rap.ucar.edu/weather/progs/prog00hr.gif) that depending on speed, may affect movement of Ivan.

If the 96-hr 500 mb heights+MSLP GFS holds true, then target-wise the AL/FL border would be a good place for chasing.

Update on prressure in Ivan: As I was in the middle of working on this post, I heard on Tv in other room that the pressure is now 914 mb. Sorry, I don't know what network mentioned it.

 

[Tim Vasquez]

MAX SUSTAINED WINDS 145 KT WITH GUSTS TO 175 KT.

Looks like we have broken the 200 mph barrier on those gusts.

Tim

 

[Chris Sokol]

Interesting set-up starting to occur: If Ivan misses Cuba and enters the Gulf, there is nothing but warm water to feed it, and New Orleans could be a bad place to live.

 

[Carrie Halliday]

I have a question.
There is a stationary front over N FL clear over to MS (if I saw that right). Is this going to affect Ivan? It has been there for several days and hasn't budged. I don't have a site to check for the trough, but last time I saw it on TWC it was TX to near New Orleans (I think).

 

[Zach Bailey]

The last two or three frames of IR satellite imagery show Ivan really shaping up and looking extremely impressive. The eye has totally cleared out and is a nice tight circle, and the coldest cloud tops have once again symmetrically encircled the eye. It looks like the warm water the hurricane is over is managing to bully out the shear...look out Cuba!