2004-09-03 FCST: Ivan (Atlantic)

[David Wolfson]

The slight eastward bias in the forecast track seems to come from some marginal west-southwest steering flow progged to exit around the long-wave trough on the west coast. This is all obviously very subtle stuff when it comes to determining whether Baton Rouge or the west Florida panhandle is the target.

Not fully factored into this by the models IMO is the effect of developing hurricane Javier off the west coast of Mexico. The marginal effect of Javier seems to be to dump some anticyclonic tendency into northeast Mexico and the western GoM. This tends to diminish and veer the marginal steering flow nudging Ivan east. New Orleans and Biloxi should definitely be concerned IMHO and FWIW.

 

[Carrie Halliday]

Originally posted by Mark Plate
The new 12Z GFS continues its trend of shifting further and further west...and it remains the easternmost model. Anywhere from the far WRN FL panhandle to New Orleans look to be at risk now, but if the western trend continues, then closer to New Orleans would be better. Note the strike probabilities on the latest advisory were highest in SE LA.

I noticed that too Mark. No one, even the heads at NHC are so sure of what Ivan intends to do. Gonna be interesting to see where Ivan comes out in the Gulf. If I were in New Orleans, I would be a little intimidated by this. Even if it does happen to go W of there, it would put them on the bad side. Not good. 600 mile wide storm as stated on TWC this morning, lots of folks are going to get some of Ivan!

 

[B Ozanne]

Left has certainly been the trend, but has anybody seen the latest sat loop? Looks like it is turning towards the north.

 

[Bob Schafer]

Originally posted by Carrie Halliday
600 mile wide storm

Check out JAX or MLB radar; Ivan's spiral bands are currently causing rain around Daytona Beach.

 

[Glen Romine]

Originally posted by Bob Schafer

Check out JAX or MLB radar; Ivan's spiral bands are currently causing rain around Daytona Beach.

Might be a bit of a stretch to attribute this rain to Ivan. A fair approximation of the size of influence of a hurricane is the radius of the outermost isobar that encloses the system. Take a look at the current pressure analysis:

http://www.rap.ucar.edu/weather/surface/us_mslp.gif

You can see this doesn't extend quite to Key West even if one was to add in more frequent contours. You can see some surface confluence in the wind vectors in the vicinity of Jacksonville - surface temps have reached the mid 80's outside of rain cooled regions, and the morning sounding suggests this is adequate for thermally forced convection. Further, a check of visible satellite shows that this convection is disconnected from Ivan - so it is probably not fair to blame Ivan for the rain in northern Florida today.

Glen

 

[David Wolfson]

Bill, my o my, it certainly looks like it has! The upper clouds in the vis are showing a pretty strong push from the southwest. If it turns any more, a lot of NHC mets and Floridians are going to have their ulcers kicking up very soon.

 

[Amos Magliocco]

Maybe I'm misinterpreting the forecast track, but it looks right on course per this map:

http://www.nhc.noaa.gov/ftp/graphics/AT09/...IF/131458W5.gif

Are you guys thinking it has lost too much of its westerly component?

 

[Anonymous]

What a storm

All I can say is what a storm... This thing has a mind of it's own and seems to keep finding ways to stay together the most... Latest Sat. loops show the system moving North, North West all of a sudden. It's like this thing can tell where land is and is just scooting its way around everything... I'd start to worry if I was in LA, or FL a lot right now. However, I do think this thing will weaken a lot over the next couple of days. Interesting system to say the least.

 

[Dan Robinson]

http://www.ssd.noaa.gov/PS/TROP/DATA/RT/fl...t-ir4-loop.html

(Check the box labeled 'forecast points') From this loop, it looks like it will pass *east* of the next forecast point.

 

[David Wolfson]

It looks like a pretty sharp turn from somewhat west of track to somewhat east of track. Either whatever force is turning Ivan diminishes quickly or it could be on an 010 or 020 that puts Tampa back under the gun. Hopefully just a wobble....

Look at the ripples in the low-mid level line spun out of the storm running from the NW Yucatan northeastward. Whatever is doing that has dug south to Ivan's latitude.

 

[B Ozanne]

TV mets might call that a wobble, but it really is a course change. It now looks like Cuba will have the first landfalling CAT 5 in some time, if it holds up at the 5pm advisory.

 

[Anonymous]

Latest outlook

I'm going to go out on a limb and say that Ivan does the same thing that it did in the past. The eye is going to get real close to Cuba but it's going to pass just to the West... That's what I'm seeing with the latest movement in the storm. Once past Cuba and back in the Gulf I think it's going to make a B line North for a bit and then start curving back East a bit toward the North-Central FL... Amazing, Amazing storm though to stay this strong for so long...

 

[Carrie Halliday]

http://www.noaanews.noaa.gov/stories2004/i...91104-1945z.jpg (from drudgereport.com)

Nice pic of Ivan from way up.

 

[Chris Hayes]

nice pic there, Carrie :thumbright:

 

[B Ozanne]

I'm looking for some good data coming out of Cuba. Unlike Jamaica and the Caymans, Cuba has a real meteorology department.

If anybody sees/hears anything from Cuba please post it.