ATL: KARL - Ex-Hurricane - Discussion

[Aquawind]

question, if a circulation seems to be absent what is giving 92 such banding?

Most of those clouds showing the spin are not at the surface and thus mid-upper level clouds..not much rain is coming from that area as the deep convection is gone..deep convection is firing on the parimeter but the twist is not at the surface..

[Steve]

>>question, if a circulation seems to be absent what is giving 92 such banding?

There is a general rotation which is plainly visible on visible.
http://www.ssd.noaa.gov/goes/flt/t2/flash-vis.html

I haven't looked at the charts, but I'd guess a broad area of low pressure at or somewhat near the surface. To me, it doesn't appear to be an upper feature, but Aquawind said he thought it was.

[vbhoutex]

question, if a circulation seems to be absent what is giving 92 such banding?

The basic answer to that is that what you are seeing is in the mid and upper levels of the atmosphere. For 92L to become anything(meaning a TC) that upper circulation has to work down to the surface and it doesn't seem in any hurry to do so attm.

[ColinDelia]

Pretty good circulation at 850 mb. This is the highest vorticity we've seen yet.
So looks pretty good at 5000 feet or whatever height that is. Not sure about at the surface.

Also looks good but a little weaker at 750 mb and not much at all near the center at 500 mb.
So seems like a circulation in the bottom part of the mid-levels more than anywhere else.

[Steve]

>>Also looks good but a little weaker at 750 mb and not much at all near the center at 500 mb. So seems like a circulation in the bottom part of the mid-levels more than anywhere else.

So it's a lower mid-level feature there (within a mile of the surface+/-). I guess that makes sense because those tend to pulse every day absent something strong at the surface (or when detached/sheared). There aren't that many surface observation points in that area, so it's hard to tell if anything is happening at sea level. But it seems to have some broad turning at least in the lower levels. JMO though as it could be part of a surge of southeasterlies.

[ColinDelia]

850 mb vorticity


700 mb vorticity


500 mb vorticity

[expat2carib]

Agree...there have been tropical waves and tropical depressions that have brought unimaginable flooding and distress to haiti. This doesn't need to be a Cat 4 to wreack havoc. In May 2004, a tropical disturbance (not even a depression) killed 2600 in haiti as it dumped 18 inches of rain in a 3-day period. We can only hope 92L moves out quickly and doesn't linger.

Noticing how much precip has spread out, now rain to ABCs, and to Dominican republic, and also into the Atlantic waters north of us. As Aquawind commented, "it has expanded." Really concerned for Haiti.
8:15AST
http://img201.imageshack.us/img201/7575 ... rb1215.gif
3:15AST
http://img808.imageshack.us/img808/6250 ... rb1915.gif

Yes I'm really concerned for Haiti as well. Most of us on the islands are sitting "high and dry" and can sit a storm out.

They can NOT on Haiti!

Here on Dominica, one of the poorest islands in the Caribbean, even the fishermen that pulll their boats on the beach too make a bed for the night out of it, go uphill to find a safe house with family, friends or churches.

They know when the water gets high and the galvanized starts flying they have to seek shelter.

For the Haitians there IS no shelter. Hundred thousands of them live in tents or on the street.

Let's hope it will be over soon, even that it's probably just a TD when it pass over.

[Houstonia]

Just curious - I see a lot of predictions of this invest moving into Mexico. Isn't that further than the 5-day cone of prediction? How come so many people already know it's a Mexico storm? Can predictions be made with a high level of certainty at this point? I don't mind the predictions, just curious about the certainty. Thanks.

not like its that defined of a center.. or anything its very broad and likely barely hanging on...

I'm not even sure I agree that it has a center unless it is a MLC we are talking about. Definitely is pulsing down right now and throwing out several outflow boundaries on the SE side. Not good for development last time I checked. If it hangs on I have to agree it will be at least Monday before I think 92L consolidates enough to be classified. Meanwhile PR etc are getting too much rain. Hopefully this phase will alleviate some of that rain for a while.

Yeah as expected development, if any, would be slow to occur. I think it's got a shot in the western Caribbean before moving inland into Mexico.

[Saints]

I see this system developing quite rapidly like one of the models predicted. Unless it ends up over the mountains of the islands and is impeded. The area of the Caribbean it is over and is projected to traverse, has had virtually no tropical activity this season. With this said, some of the models are probably on to something. As a matter of fact, it would not surprise me to see a Gilbert type track, but not with the intensity of a Gilbert. That would be very foolish to even remotely predict a storm of that magnitude.

The NHC has a good grasp on things folks. They do the best job around, without question. I saw some one of their initial model forecasts Thursday afternoon, taking it NW, then WNW over Jamaica and then west, towards the general direction of the western tip of Cuba/Yucatan channel. It appears like this will be the track the way things are shaping up, which is pretty remarkable. That's crazy how accurate they have become. Just my opinion.

Thank goodness for the forecasted high pressure setting up over the GOM, to protect the U.S.

[cycloneye]

Aric,do you see something that gets your attention from the data of this bouy located at 15N-67W? Or nothing to open eyebrows?

http://www.ndbc.noaa.gov/station_page.php?station=42059

[Aric Dunn]

Aric,do you see something that gets your attention from the data of this bouy located at 15N-67W? Or nothing to open eyebrows?

http://www.ndbc.noaa.gov/station_page.php?station=42059

I have been watching it all day actually and its been veering from NE to now east. so if there is anything at the surface it would have to be south of there somewhere.. which would place something closer to the mid level circ. but the one observation could point to a surface circ or it could point to a open wave just as easy. if there were more observations near by then we could say something. right now im leaning towards very little at the surface. if convection begins to build associated with the MLC then its possible there is a weak surface reflection. So more waiting ...

[Dean4Storms]

UL outflow looks fairly good, this could get going overnight and into tomorrow.

[cycloneye]

Aric,do you see something that gets your attention from the data of this bouy located at 15N-67W? Or nothing to open eyebrows?

http://www.ndbc.noaa.gov/station_page.php?station=42059

I have been watching it all day actually and its been veering from NE to now east. so if there is anything at the surface it would have to be south of there somewhere.. which would place something closer to the mid level circ. but the one observation could point to a surface circ or it could point to a open wave just as easy. if there were more observations near by then we could say something. right now im leaning towards very little at the surface. if convection begins to build associated with the MLC then its possible there is a weak surface reflection. So more waiting ...

Thank you for your always to the point observations.Keep them comming.

[Dean4Storms]

Aric,do you see something that gets your attention from the data of this bouy located at 15N-67W? Or nothing to open eyebrows?

http://www.ndbc.noaa.gov/station_page.php?station=42059

I have been watching it all day actually and its been veering from NE to now east. so if there is anything at the surface it would have to be south of there somewhere.. which would place something closer to the mid level circ. but the one observation could point to a surface circ or it could point to a open wave just as easy. if there were more observations near by then we could say something. right now im leaning towards very little at the surface. if convection begins to build associated with the MLC then its possible there is a weak surface reflection. So more waiting ...

Pretty sure this is just a wave with broad low pressure still, seen nothing to indicate a closed surface low. Like Aric said, if convection can fire near the wave axis/MLC spin and persist it could get a surface reflection going and work toward closing off.

[Macrocane]

Just like yesterday and the day before the cloud tops have warmed a lot, let's see if tonights d-max is the definitive one.

[Kludge]

Just curious - I see a lot of predictions of this invest moving into Mexico. Isn't that further than the 5-day cone of prediction? How come so many people already know it's a Mexico storm? Can predictions be made with a high level of certainty at this point? I don't mind the predictions, just curious about the certainty. Thanks.

Houstonia....
Please realize... they don't "know". A number of folks on this board prognosticate as if they have some form of devine insight. You and I know they don't, and are simply using their hindsight and luck to take an educated (hopefully) guess as to what will happen.

The fun part of this is that man still doesn't have the tools to predict with certainty what will happen, so this is one of the few remaining frontiers where folks like me and you can come laugh at the "experts" who claim to know the final outcome of these amazing wonders of the world.

Note that some of the posters are labeled as "pros", which, although they are skilled forecasters, means they don't have to include the disclaimer "in my opinion". Just grin and let it go... and use the NHC as your source for infomation regarding hurricane preparedness...

[jinftl]

I'm sure some of the more experienced posters could elaborate on this better - but if there is no closed, low level circulation at this point, putting too much weight on what model runs are saying right now is educated guessing at best - or a crap shoot.

[Aric Dunn]

I'm sure some of the more experienced posters could elaborate on this better - but if there is no closed, low level circulation at this point, putting too much weight on what model runs are saying right now is educated guessing at best - or a crap shoot.

well in every case they are educated guesses ... of course some guess are more educated than others.. lol but in general organization and strength play a role in track. take for instance the HWRF it has been little stronger and much more north.. same with the NAM and CMC. the models that have more of a northerly component develop it faster.. So in general we dont exactly know what will happen right now. if it develops we will have a better understanding so we just have to wait.

[latitude_20]

Methinks we need a recon mission to get better measurements for the models to work with?

[wxman57]

Just curious - I see a lot of predictions of this invest moving into Mexico. Isn't that further than the 5-day cone of prediction? How come so many people already know it's a Mexico storm? Can predictions be made with a high level of certainty at this point? I don't mind the predictions, just curious about the certainty. Thanks.

Disturbances and storms track along with the winds aloft. If the winds above a system are blowing from east to west, then the system moves to the west. The models are fairly good at predicting the positions of highs and lows in the middle and upper part of the atmosphere for 5 days out and often quite farther out.

In this case, the models are indicating that the high pressure area over Texas in the mid levels of the atmosphere will extend eastward across the Gulf over the coming week. That means the winds aloft will be blowing from east to west across the western Caribbean and southern Gulf of Mexico. And since the winds aloft are blowing to the west, that's where the disturbance (or storm) should go. It will move westward to the south of the big area of high pressure to its north.

Here's a map showing the predicted position of the high center by both the American GFS model and the European model for next Wednesday. With that kind of flow present when the disturbance reaches near the Yucatan, it really can't turn north or head to Texas. That is, unless all the models are completely wrong about the position of the high center.