5:30 TWO=Broad Low Pressure Forms in NW Caribbean

[x-y-no]

For those of us who are ignorant (me) can you post an image of an LLC?

One of my favorite examples from last year was the LLC that popped out from under Jeanne and headed SW to Cuba. A lot of us (myself included) thought that was likely the end of Jeanne, but another LLC formed back under the main convection.

You can see the LLC in this picture at about 20.5N 74.0W (near the eastern tip of Cuba):

http://www.nrlmry.navy.mil/archdat/tropical_cyclones/tc04/ATL/11L.JEANNE/vis/geo/1km/20040918.2045.goes12.x.vis1km.11LJEANNE.35kts-1005mb-217N-722W.jpg

Jan

[cycloneye]

For those of us who are ignorant (me) can you post an image of an LLC?

At pic the LLC is exposed on tropical storm Hanna in 2002.

[senorpepr]

For those of us who are ignorant (me) can you post an image of an LLC?

One of my favorite examples from last year was the LLC that popped out from under Jeanne and headed SW to Cuba. A lot of us (myself included) thought that was likely the end of Jeanne, but another LLC formed back under the main convection.

You can see the LLC in this picture at about 20.5N 74.0W (near the eastern tip of Cuba):

http://www.nrlmry.navy.mil/archdat/tropical_cyclones/tc04/ATL/11L.JEANNE/vis/geo/1km/20040918.2045.goes12.x.vis1km.11LJEANNE.35kts-1005mb-217N-722W.jpg

Jan

Excellent example, Jan. I remember that event taking place. That sure was something.

[dhweather]

A broad area of low pressure does not an LLC make!!!!! Two TOTALLY DIFFERENT things!!!!

Thank you.

[Matt-hurricanewatcher]

[senorpepr]

:(

I nominate that reply for the "2005 Most Unique Display of Smilies" award.

That vomiting smiley still freaks me out..........

[Derek Ortt]

Did look at some close up visible loops today at the office. There is some cyclonic turning, may be closed. HOWEVER, it is 300NM wide, taking up the entire Caribbean and appears to be due to the UL low to its west. Purely QG forced and nothing tropical at all. Plus, the winds cannot be more than 5-10KT in the Caribbean at the surface anyways.

The low is VERY poorly organized and has little chance of tropical cyclone formation anytime soon

[Cookiely]

Thank you Matt and Cycloneye for the image. I really appreciate them. Are some cloud types better than others in the formation of an LLC in its organization?
I found an article on LLC and I was wondering what type of clouds and shapes are they talking about they didn't say?
"cloud type, cloud shape, and tightness of the rings of cloud lines forming the circulation."

[dhweather]

For those of us who are ignorant (me) can you post an image of an LLC?

One of my favorite examples from last year was the LLC that popped out from under Jeanne and headed SW to Cuba. A lot of us (myself included) thought that was likely the end of Jeanne, but another LLC formed back under the main convection.

You can see the LLC in this picture at about 20.5N 74.0W (near the eastern tip of Cuba):

http://www.nrlmry.navy.mil/archdat/tropical_cyclones/tc04/ATL/11L.JEANNE/vis/geo/1km/20040918.2045.goes12.x.vis1km.11LJEANNE.35kts-1005mb-217N-722W.jpg

Jan

Or Ivan's LLC off the Atlantic Coast, moving South.

[JTD]

Can someone help me out:

I seem to remember from last year that NHC outlooks would say something like there is a broad area of low pressure somewhere that is disorganized and the potential for development is not favourable at this time. Something like that.

Is that right? So, hence, a broad area of low pressure by itself should not cause excitement?

What's really going on here is that since the season has started, we're all eagerly awaiting the 1st named storm because after we get the 1st named storm, broad areas of low pressure won't get this much attention. Is that what essentially is going on?

[Cookiely]

Thank you x-y-no for the link. I am beginning to understand now. I saw something on one of the radars that looked like a partially open LLC, is there a name for that?

[dhweather]

Can someone help me out:

I seem to remember from last year that NHC outlooks would say something like there is a broad area of low pressure somewhere that is disorganized and the potential for development is not favourable at this time. Something like that.

Is that right? So, hence, a broad area of low pressure by itself should not cause excitement right?

What's really going on here is that since the season has started, we're all eagerly awaiting the 1st named storm because after we get the 1st named storm, broad areas of low pressure won't get this much attention, right?

Jason - yes, a broad area of low pressure by itself is nothing to get excited about. Worth watching? Yes.

As for the attention, yes, there will be a lot of it once the season gets
going good. Each broad area of low pressure has a better chance
than a "blob of clouds" to develop into something. Usually, it would
require a favorable environment and time for a broad low to develop into
a depression.

Does that answer your questions?

[dhweather]

Thank you x-y-no for the link. I am beginning to understand now. I saw something on one of the radars that looked like a partially open LLC, is there a name for that?

Radar or Satellite?

On radar, it would be referred to as an open eyewall

On a satellite, it's typically called the low level circulation being exposed,
most likely caused by shear.

[Cookiely]

Thank you x-y-no for the link. I am beginning to understand now. I saw something on one of the radars that looked like a partially open LLC, is there a name for that?

Radar or Satellite?

On radar, it would be referred to as an open eyewall

On a satellite, it's typically called the low level circulation being exposed,
most likely caused by shear.

Thanks for taking the time to explain. That's very kind of you.

[Brent]

An open eyewall would have an intense ring of convection but on part of it, it would not exist. With an exposed LLC/weak system there may be no rain at all on one side of the system(usually the left side) or very little.

[tallywx]

Did look at some close up visible loops today at the office. There is some cyclonic turning, may be closed. HOWEVER, it is 300NM wide, taking up the entire Caribbean and appears to be due to the UL low to its west. Purely QG forced and nothing tropical at all. Plus, the winds cannot be more than 5-10KT in the Caribbean at the surface anyways.

The low is VERY poorly organized and has little chance of tropical cyclone formation anytime soon

I agree with most of what you said completely, save for the fact that the new NW Carib. buoy is currently reporting surface winds sustained at 27 kts, gusting to 31 kts, out of the ESE. The complete ob and history can be found here:

http://www.ndbc.noaa.gov/station_page.php?station=42056

[Derek Ortt]

There's a 27KT wind in THAT?

Wonder if it is trade wind enhanced or something because nothing suggests that that circulation should be able to produce a 30KT wind

[hurricanefloyd5]

i disagree because tom terry said if the shear weakens just abit for formation then he said we could/might have some tropical trouble!!!!!!!!!!!!!!!!!!!!!!!!!!!!! p.s. dont forget to watch hurricane alert 2005 tonight at 10 .pm.!!!!!!!!!!!!!!!!

[dhweather]

There's a 27KT wind in THAT?

Wonder if it is trade wind enhanced or something because nothing suggests that that circulation should be able to produce a 30KT wind

That caught me offguard as well Derek - perhaps it's a combination of
trade winds and the broad low.

[tallywx]

i disagree because tom terry said if the shear weakens just abit for formation then he said we could/might have some tropical trouble!!!!!!!!!!!!!!!!!!!!!!!!!!!!! p.s. dont forget to watch hurricane alert 2005 tonight at 10 .pm.!!!!!!!!!!!!!!!!

A humongous big IF, because if anything shear should hold its own or even increase. Couple that with this thing only having a window of about 48 hours at most before "landfall"...well, I've seen stranger things happen in this region, and formation of this would be mighty strange.