ATL: ISAAC - Post-Tropical - Discussion

[cheezyWXguy]

If it were to somehow bomb out would that make it go poleward more as other storms have?

No, this is going to be steered by large scale factors such as the high to the north and the trough lifting out of the east coast, and smaller scale factors like the vort max to its west, south of western cuba. The concept of a storm moving more poleward as it increases in strength is more important in the deep tropics like in the MDR and the Caribbean.

no, that occurs not matter what latitude.

Sorry, I worded that wrong. Im having a hard time getting my thoughts out on this. It would just be easier to call myself wrong haha.

[Recurve]

Of course that's true too. The beta effect as I understand is in the absence of other factors. A few factors influence storm direction, some small, some large, some not fully understood maybe. Andrew could not get out from under that ridge and got drove straight westward as well.

[tailgater]

I read back a couple pages but didn't see where anyone mentions the 850 vorticity in the NW Caribbean, I thought I saw where some of the models had like 2 systems until the one north of Cuba took over. probably doesn't mean squat.

[ozonepete]

Yep and backs up my statement earlier that it would get pulled away from the coast by developing convection on the north, east, and west sides...look out

appears recon latest center fix is nnw of the previous one makes me back up my statement that its being pulled towards the developing convection.

IMHO you are both quite right. Because western Cuba is so flat covered by tropical air, that land won't inhibit Isaac much at all. Since the center iis clearly offshore now and it has no dry air getting into the circulation and especially since it has really impressive outflow and high SSTs under it there is a good chance this will intensify pretty rapidly now. Maybe not RI by the book, but it seems quite possible.

[SapphireSea]

Coriolis effects still are in effect as a cyclone moves. Unless a ridge sits on top of a cyclone, it will trend slightly northward as it progresses at any strength. We have seen very shallow systems move WNW with no troughing pulling them away. The ridge that holds them has been aligned more E-W further up in latitude. Stronger systems erode mid-low level ridges and strengthen upper level high pressures which complicate tracks in extremely powerful systems.

[Aric Dunn]

:uarrow: Of course that's true too. The beta effect as I understand is in the absence of other factors. A few factors influence storm direction, some small, some large, some not fully understood maybe. Andrew could not get out from under that ridge and got drove straight westward as well.

and actually all rotating objects, weather systems, galaxy's experience this. even weak TD's its just more pronounced in hurricanes because to put it simply they are rotating faster.

[meriland23]

Is this still hugging cuba? I have been curious about whether the eye is in position to strengthen, or if it is currently

[Shawee]

I've heard many people over the years say "The water in the Gulf is so warm...a hurricane can just explode!" when in reality it can't. It doesn't matter of SSTs are exceedingly warm or not. If the atmospheric conditions aren't right (and it lacks the structure) the storm simply cannot intensify to any great extent, to say nothing of RI. That being said, that *may not* be the case here.

Going along with NHC's estimation, a Cat 2 certainly isn't out of the realm of possibility here by any means. We've seen many storms get their act together in a hurry.

Also size of wind field play a hugh factor in surge heights..

Frank, great point a lot of folks (myself included) overlook. Camille was a 5; massive destruction, but not nearly as broad as the K/R sisters of 05. Not discounting anything with this one... or belittlinging the distruction that can be caused by even a "small" storm. We all have to keep our guards up and pray for the best with good preparations. hopefully the dry air to the west will keep in somewhat disorganized and the surge manageable for who ever gets this one.

[Recurve]

True that Ozonepete.

I'm sure my friends in the Keys are taking this seriously, especially the Upper Keys, could be significant sure in Port Largo. US 1 will almost certainly go underwater at Sea Oats beach around mm 75.


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The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[edit to add disclaimer]

[Frank P]

Looking at the vis sat loops Isaac continues to move NW with convection continuing to build north of the center... looks to be paralling the Cuba coast at a pretty good clip I might add... My untrained and unprofessional opinion only.. always refer to the NHC and your local govt for official reports and forecasts.

[GCANE]

RAP Analysis is showing extreme unstable air SW off the coast of FL.

CAPE = 6000

http://www.spc.noaa.gov/exper/mesoanaly ... sector=18#

This is in the path of Isaac.

Needless to say it will change by the time he gets there.

Something to keep an eye on.

[ozonepete]

no, that occurs not matter what latitude.

Sorry, I worded that wrong. Im having a hard time getting my thoughts out on this. It would just be easier to call myself wrong haha.

That's ok - we all do it and you make great posts. Yes, the Beta effect is always going on for TCs moving west or even north in the Atlantic. It is a function of size and strength, so the bigger and stronger Isaac gets the more it would tend to nudge to the right. But it is also true that other effects, such as really strong ridging on the right side of the storm can pretty much negate it, which I think is what you meant.

[pricetag56]

my personal opinion is this will be a low cat 3, IMO

its very possible

[cheezyWXguy]

RAP Analysis is showing extreme unstable air SW off the coast of FL.

CAPE = 6000

http://www.spc.noaa.gov/exper/mesoanaly ... sector=18#

This is in the path of Isaac.

Needless to say it will change by the time he gets there.

Something to keep an eye on.

wow, 6000? that is high. When you see that in the great plains, thats the kind of instability that leads to a severe weather outbreak...

[Meteorcane]

RAP Analysis is showing extreme unstable air SW off the coast of FL.

CAPE = 6000

http://www.spc.noaa.gov/exper/mesoanaly ... sector=18#

This is in the path of Isaac.

Needless to say it will change by the time he gets there.

Something to keep an eye on.

This could be important, because apparently based on charts wx has shown General instability in the GOM has been lower than climatology thus far this year, if it can hit some unstable pockets (possibly enhanced by that area of spin over the southern Gulf today) it should be able to generate convection/energy. I think this may be a key factor in the intensity discussion, Anyone seen Key West soundings/Forecast soundings?

[Aric Dunn]

Is this still hugging cuba? I have been curious about whether the eye is in position to strengthen, or if it is currently

its not hugging it its far enough off the coast that there are west winds over water which means the whole center is over water. its still close enough that any strengthening will be slow. but it appears to be moving away at a sharper angle so it may very well intensify tonight.

[jhpigott]

Is this still hugging cuba? I have been curious about whether the eye is in position to strengthen, or if it is currently

its not hugging it its far enough off the coast that there are west winds over water which means the whole center is over water. its still close enough that any strengthening will be slow. but it appears to be moving away at a sharper angle so it may very well intensify tonight.

Aric - if you had to guess, does Isaac pass closer to Key Largo or Key West?

[Senobia]

Here's our forecast from the southern TX/LA border, via local mets and Twitter:

Isaac continues NW along the north coast of Cuba and Disorganized. Landfall next week well to our east with drier Wx for SE Texas.

[Vortex]

N and E quad building nicely now...interesting night ahead.

[Aric Dunn]

Is this still hugging cuba? I have been curious about whether the eye is in position to strengthen, or if it is currently

its not hugging it its far enough off the coast that there are west winds over water which means the whole center is over water. its still close enough that any strengthening will be slow. but it appears to be moving away at a sharper angle so it may very well intensify tonight.

Aric - if you had to guess, does Isaac pass closer to Key Largo or Key West?

to be honest its so close that a couple hour wobble would put in almost on the main land of florida. no one will be able to predict those types of movements.