2004-09-03 FCST: Ivan (Atlantic)

[mikegeukes]

Cuba - Instituto de Meteorología
http://www.met.inf.cu/

Its in Spanish.

Mike

 

[B Ozanne]

Iván mantiene vientos máximos sostenidos de 260 kilómetros por hora, con una presión central ahora de 912 hectopascal, por lo que continúa siendo un intenso huracán categoría 5, máxima en la escala Saffir-Simpson.

I don't speak Spanish, but I got the gist of it.

 

[Zach Bailey]

Originally posted by B Ozanne

Iván mantiene vientos máximos sostenidos de 260 kilómetros por hora, con una presión central ahora de 912 hectopascal, por lo que continúa siendo un intenso huracán categoría 5, máxima en la escala Saffir-Simpson.

I don't speak Spanish, but I got the gist of it.

Pretty much all cognates - but here's a translation just for kicks:

Ivan maintains maximum sustained winds of 260km/hr (162.5mph), with a current central pressure of 912hPa (mb), because of this it continues to be an intense category 5 hurricane, the maximum in the Saffir-Simpson scale.

 

[Jeff Snyder]

It's fascinating to what the continued trend of westward shifts in forecast track. Early guidance from the 0z runs indicating that the GFS has shifted westward again, now with showing Ivan making landfall west of Mobile. The NOGAPS, which has been on the western edge of the guidance envelope, has also shifted westward, now indicating landfall south of Baton Rouge (putting New Orleans in the eastern side of the storm)... Because of this, the latest 11pm track from the NHC has now shifted the landfall to near Mobile... Interesting...

The shortwave trough / upper low over the southeastern US (possible low centered near TN) will likely continue to move northeastward, away from the Gulf. This feature will be followed by a shortwave ridge, nor over TX, which will likely preclude Ivan from taking an easterly component to its motion. As the cane nears the northern Gulf, however, this shortwave ridge passes as a strong trough drops down from the central US, which should begin a northeasterly movement... Of course, as we all know, things can change very quickly...

 

[Dan Robinson]

This chase gets harder to call with each new advisory. Landfall is now overnight Wednesday into Thursday. Don't want to drive 1,800 miles round trip and 14 hours one way for a nighttime power flash fest. I want a daytime eyewall, so waiting now for the 11AM to decide. Also watching Jeanne, which may give a closer-to-home opportunity.

 

[Thomas Loades]

I'm inclined to think that there's still potential for Ivan to move further west. Going by the latest synoptic chart, there's a large anticyclone whose southern edge is juts out to the SE, but curves in to the W — it kind of fits the shape of the Gulf Coast, dipping down around the FL peninsula then recurving up. Anyway, where it ends there's a large gap left between another high to the west, and a low to the north. If Ivan goes around the edge of this high, and into that gap, it would make landfall around western LA and the TX coast. Be interesting to see how this pans out.

 

[Jeff Snyder]

Just for the note, Ivan is filling rapidly (albeit likely temporarily), with central pressure up to 930mb, and max flight-level winds only to 112 kts (!!). The system looks to be undergoing an eyewall replacement cycle, though this is by far the most the storm has been weakened by such a cycle. The eye the past few hours has been wobbling between NW-NE... 7am intermediate advisory took Ivan down to a Cat 4, though pressure has risen still nearly 10mb since then...

 

[MClarkson]

landfall looks to be towards thursday morning... hopefully the storm slows down just slightly...

 

[Zach Bailey]

My guess as to the recent filling/weakening of Ivan is due to the westerly shear increasing as well as this westerly shear bringing in dry air from the west and disrupting the circulation. Not to mention Ivan is about due for an eyewall replacement cycle. As for the current track forcast, it looks like Ivan could be just a little east of the predicted track, however it could very well be a wobble due to the eyewall replacement cycle.

 

[Glen Romine]

The NHC discussion does discuss what you mentioned Zach, but the collapse of the eyewall is probably the most important factor right now. Since Ivan is moving toward a region in the Gulf where the warm water is relatively shallow, that should hamper Ivan's ability to regain structure until it moves out over the warm core eddy - but if Ivan spends enough time over that feature, it might be able to still make landfall as a major hurricane.

http://www.aoml.noaa.gov/phod/cyclone/data...004257cad26.png

It's been disappointing to me how the model forecast tracks have been relatively consistent with each other in wobbling back and forth on landfall location. Hopefully when it comes time to start issueing hurricane warnings it will be more clear what portion of the coast will be most at risk.

 

[Bridget Beddow]

I just went home and watched the Weather Channel in regards to Ivan.

This really threw me off.

They showed a picture of the satellite image of Ivan, and then placed the little red "hurricane marker" on the north-western edge of Ivan and showed the projected path from there to move north into the Alabama/Florida line.

The NHC discussion does discuss what you mentioned Zach, but the collapse of the eyewall is probably the most important factor right now. Since Ivan is moving toward a region in the Gulf where the warm water is relatively shallow, that should hamper Ivan's ability to regain structure until it moves out over the warm core eddy - but if Ivan spends enough time over that feature, it might be able to still make landfall as a major hurricane.

Is this part of what is occurring as far as the collapse of the eyewall?

 

[Ryan McGinnis]

Here's a great link to ocean bouys near Ivan:

http://www.ndbc.noaa.gov/radial_search.php...dist=350&time=3

 

[Cstok]

Cam in New Orleans showing the traffic on the causeway.

http://www.theneworleanschannel.com/liveca...cams/index.html

Anyone else have some good cams along the gulf, so we can check the view / surf?

 

[Zach Bailey]

I'm not sure if this is relevant to a forecast thread, but my girlfriend goes to school in New Orleans at Loyola and the school has closed until monday. She left for home (Atlanta) today and it doesn't look like she'll be headed back there until Sunday. It's for the best, I suppose...I would rather her not be down there and the hurricane miss than her down there and the hurricane hit, since New Orleans is pretty much the #1 spot not to be in a hurricane.

 

[Austin Ivey]

Originally posted by Ryan McGinnis
Here's a great link to ocean bouys near Ivan:

http://www.ndbc.noaa.gov/radial_search.php...dist=350&time=3

Here is the link to a graphical output of air pressure, wind speed and wind gusts for the bouy closest to Ivan:

http://www.ndbc.noaa.gov/plot_wind_pres.ph...ion=42003&uom=E