Ivan Advisories

[charleston_hugo_veteran]

thats true! I've seen them do loops!

[dennis1x1]

wow....and dont confuse this with the report of "20 ft waves" from the big media on jamaica.....

waves would be on top of the surge...

[~SirCane]

1 looks likely and 2 isn't out of the question.

[Raebie]

At least the eye? What is the best and worse case scenario at this point.

I'm sorry to start a new thread on this, but I've been listening to them on the web for 5 hours now, and have received 2 emails from the DJ's. They need info. What's going on with the immediate track?

TIA

[Wnghs2007]

i think this goes without saying based on any model really.

That was just a snidbit of the really long discussion. I did not want to post the whole thing here due to bandwidth Issues. But you can go to the link and see.

[dennis1x1]

yes..the eyewall has somewhat of a chance of missing the Caymans.....and therefore sparing the cat 4/5 winds......missing cat 2 winds is more unlikely.

over the past 6 hours or so the storm has not made much progress north at all...to receive the actual ne eyewall the storm would have to average around a 300 degree course until landfall...again..this is the eyewall and 155mph winds that extends only a couple miles from the edge of the actual eye.

the strong ne quadrant of the storm and associated cat 1-2 winds extend much further than that and grand cayman can expect to receive these unless a due west course continues for many more hours.

[donsutherland1]

As had been the case earlier, Hurricane Ivan continued to track somewhat farther to the south than what I had anticipated.

Earlier, I thought that he would reach 80.0W at 18.8N latitude. Instead, he passed reached 18.3N 80.0W at 11 pm EDT. That's approximately 35 miles south of where I had him.

With Ivan maintaining a west-northwest track and the computer guidance having continued a westward shift, my general idea of a Panhandle landfall has increased. However, I am now giving greater credence to the Camille track in making adjustments.

My expected track is as follows:

20.0N 82.5W
22.5N 84.3W
25.0N 85.3W
27.5N 85.8W
30.0N 85.7W

At this time, I believe the NOGAPS Model offers the best idea as to my thinking as Ivan nears U.S. landfall:

http://www5.wright-weather.com/bb/attac ... tid=314713

One thing that will bear watching will be Ivan's trajectory immediately prior to landfall.

Of all the 18 Category 4 or stronger hurricanes that have made landfall in the United States, just one had an easterly component to its track immediately ahead of landfall. That Category 4 storm was Charley. All others have had no easterly component immediately prior to landfall.

Thus, if one fails to see Ivan begin to fade to the east ahead of landfall, the danger of a Category 4 or stronger storm making landfall would be higher than if one sees that fade.

What is encouraging is that the greatest hurricane heat content appears to lie prior to a western Cuba landfall. Afterward, the hurricane heat content is less favorable:

2004091118 ACT 18.00N 79.00W 31.722
2004091212 FOR 19.60N 81.00W 30.696
2004091300 FOR 21.00N 82.00W 29.652
2004091312 FOR 22.80N 83.00W 0.000
2004091412 FOR 27.00N 84.50W 7.348

At the same time, the eastern Gulf of Mexico has seen mid-level wind shear increase recently. If that trend is sustained, it could also tend to erode Ivan or at least cap his potential.

However, if Ivan tracks toward the central or even western Gulf of Mexico e.g., Louisiana, it could move into an area of diminishing wind shear.

For now, Ivan remains an extremely dangerous and menacing storm.

[Sean in New Orleans]

yes...jogging along almost due West...just a tad above due West... http://www.ssd.noaa.gov/PS/TROP/DATA/RT ... -loop.html

[Greg]

I had problems getting Netscape to open mediaplayer. The fix is to select setup (the tiny yellow button) select other MP3 player. The browser tries to launch the old media player. Find the .pls file in your temp folder. Hold shift while selecting it and choose "Open With". Pick Wordpad. Find the URL, and copy it (CTRL-INS). Open Mediaplayer and select "Open URL". Paste the link in (SHIFT-INS).

You can also save the link all by itself in a .m3u File.

The link has your IP in it, so I can't just give the link in the forum.

HTH

[miamijaaz]

I noticed in the latest water vapor imagery that the high pressure above Ivan and just south of the Florida peninsula seems to have split down the middle and there now seems to be a path through it and to the north.

http://www.ssd.noaa.gov/PS/TROP/DATA/RT/watl-wv-loop.html

Is this the weakness the NHC has been expecting that would lead to a more north movement?

[Guest]

ever since last night I've had a funny feeling about Mexico.

its kinda one of those http://mainportals.com/precog.shtml

[bahamaswx]

Aren't those 100kt winds?

[Tri-State_1925]

I'm no expert, but the worst case scenario is a 165 mph storm hitting them directly and completely destroying the islands. This thing is stronger than Gilbert was at this point. The current motion may indicate that the eye will pass slightly south of the islands, but after seeing what happened with Jamaica last night, I don't think anyone knows for sure within 50 miles where this thing will jog/swing/move over the next few hours.

[~SirCane]

It's very worrysome.

It's so big it's going to affect a lot of people up here!

[glopst7162]

10 PM update just read on the station.

Hurricane Ivan is expected to come near or go over the Cayman Islands sometime Sunday.

Current position is 18.3 N by 80.3 W. Moving WNW at 8 MPH. It is 105 miles SE of Grand Cayman island. Winds at 165 MPH.

[debbiet]

Okay...I'll bite. Not trying to be a smart___ but What does FFC and CWA stand for and why is this any scarier than anything else we've seen or heard about where the storm is likely to come in? Just don't understand.

[charleston_hugo_veteran]

It's very worrysome.

It's so big it's going to affect a lot of people up here!

yeah...my met said it will effect even us!
To what degree, he is unsure!

[buckma78]

I've noticed that also and was wondering the same thing. Anyone have any ideas?

[dennis1x1]

since my post another 30 mins of sat pics were sent down....and i know that we arent supposed to report 1 or 2 frames trends..however based on the closeness to grand cayman they are very important..

a nearly due northward "jog" has taken place the last 30 mins or so.....at the very least this appears to be the end of the due west.....

the next couple of hours will clear up exactly how long of a jog this might be and how it may affect grand cayman...

my analysis came from here....particularly the 2:45 frame....and continuing nnw into the 3:15 frame...all in all this has meant a nearly 10-20 mile jump north in the last hour.....

http://www.nrlmry.navy.mil/tc-bin/tc_ho ... 98W.INVEST,

[Sean in New Orleans]

Here are the latest thoughts from John Gumm, local met here in New Orleans on WWL-TV. As most of you know, our local mets, here in New Orleans, have been posting on a local weather forum with detailied discussions for our area. This discussion mainly pertains to metropolitan New Orleans. He sounds much more concerned this evening about the New Orleans region. Again, here is a link to keep things legal... http://www.wwltv.com/cgi-bin/bi/discuss ... apsed&sb=5

**********************************************************

*EVERYONE FROM LOUISIANA TO THE FLORIDA PANHANDLE NEEDS TO MONITOR THE PROGRESS OF HURRICANE IVAN

*MOST LIKEY LANDFALL CENTRAL TO WESTERN FL PANHANDLE BUT A STRIKE ANYWHERE FROM LA TO FL IS POSSIBLE

*CLOSELY WATCH FOR CHANGES IN TRACK FORECAST

Current Analysis:

Ivan has exploded tonight. This is the strongest he has been yet with surface estimated winds of 165 mph and a pressure of 910 millibars. Ivan is now one of the strongest hurricanes ever in the Atlantic Basin and a category 5 on the Saffir-Simpson Hurricane Scale.

Movement continues to stair step to the WNW. You'll notice a west motion for a while, then a NW motion, thus the term "stair step". Motion appears to have slowed down to around 9 mph.

I believe Ivan is peaking tonight and as eyewall replacement cycles continue, he will likely begin to weaken later tonight or tomorrow morning. But not much else can be said about this storm. It is simply a monster.

Forecast Track:

Ivan has defied most model guidance to this point, staying to the left of almost every model track. There is no reason to assume this will not continue, so until I see otherwise, I will still be leaning to the left of most model guidance for this update.

The FSU Super Ensemble run was sure on a couple days ago as it pointed to Pensacola. All other models have seemed to since then follow it. I am still trying to determine what this model is doing tonight, and if I find out, I will add it to this discussion.

Ivan missed Jamaica to the south after looking like he would slam straight into the island. This westward jog has continued much of the day. It's likely a mid-level high to the north of Ivan is resulting in this motion now. It's this mid-level high that was forecast to weaken by the models as it was squeezed between an upper low over the central Atlantic and a trough moving in from the west. If you recall, I have been saying all along that there were so many variables that had to come together in the models for the initial track to work out. That is, the track that took it up the west side of FL. Well ladies and gentlemen, we've seen what happens when one of those variables goes bad. Let's hope we don't see anymore variables go bad with the current forecast.

Expect Ivan to continue on this WNW motion for a while, and at a fairly slow pace. What we watch for next is a sign of a more NW motion. At this point in the game, I think it's fair to say a track through the Yucatan Channel is looking more and more likely. Ivan could perhaps pass over the western side of Cuba, but I would be surprised. By Monday, he should be in that general area.

Here's the deal - if Ivan continues to slow down and trend more west, there is a chance the trough which is going to drop down over the northern Gulf WILL NOT EVEN PICK HIM UP. This would mean a track pretty much due west, perhaps into the Yucatan. However, I still think this isn't likely….yet. But it will all depend on how the weak high over the Gulf breaks down, or doesn’t break down. Right now, this appears to be the least likely scenario, but still an option. In fact, the ETA model does this very thing tonight. Keep in mind, the ETA model isn't usually good with hurricanes.

The models continue to show a weak trough dropping down over us…emphasis on the word WEAK. That is pretty visible tonight on the water vapor imagery. THIS TROUGH IS KEY TO THE FORECAST. If the trough weakens the ridge enough, Ivan will move toward this weakness and he will begin to turn NW and then pretty much due north. Depending on how strong the trough turns out to be it could possibly even turn him NE at some point. IF IVAN GETS FAR ENOUGH WEST, THE LANDFALL LOCATION COULD BE MOVED FURTHER WEST ON THE GULF COAST. This is what I am worried about the most now.

The Canadian model is the only one I have seen that suggests LA could be impacted. All others are clustered on the FL panhandle. This is good news for us, but with the recent trends in the models, we will certainly need to pay close attention to the future trends in these models.

This is far from over, but based on the current information available, I am leaning toward a landfall in the western FL panhandle sometime Wednesday. Of course this will likely change over the next couple days, but that's my best guess now. At any rate, we all need to watch the trends here and see what happens.

The chances of it coming this far west still remain slim, but we ARE WITHIN THE MARGIN OF ERROR ON THE OFFICAL FORECAST. This means everyone should have a detailed, written plan as to what you would do if we happened to become threatened by this storm.

I will have more as time allows and as new information becomes available.


John Gumm
Meteorologist
WWL-TV
1024 North Rampart Street
New Orleans, LA 70116