ATL: ISAAC - Post-Tropical - Discussion

[ConvergenceZone]

NE shear Aric and the fact is still trucking along at a good clip.....LLC exposed and popped out above 15N now....

Rock, when you say, "the LLC is exposed and popped out" does that mean
that the depression has opened to a wave?

no...not going to open up to a wave...

Okay, just wanted to clarify. Thanks!

[ozonepete]

Yes that was my thinking that the updraft stays moist=weight which in turn adds force for acceleration?to make the punch.

Don't understand the "moist=weight" thing. Water vapor is lighter than air molecules. Moist warm air is less dense, not more dense.

absolutely. witness the lifting mechanism on the high plains of the "dry line" for convective initiation. dry air is much heavier than moisture laden air.

Javlin, the force for upward acceleration is the buoyancy of the very warm moist air parcels in the updraft of the thunderstorm. These parcels are so much lighter - less dense - than the parcels outside the updraft that they rise rapidly to reach equilibrium. They acheive pretty impressive upward speeds while doing this, and that increases the intensity of the updraft and thus the storm itself.

[Javlin]

Yes that was my thinking that the updraft stays moist=weight which in turn adds force for acceleration?to make the punch.

Don't understand the "moist=weight" thing. Water vapor is lighter than air molecules. Moist warm air is less dense, not more dense.

absolutely. witness the lifting mechanism on the high plains of the "dry line" for convective initiation. dry air is much heavier than moisture laden air.

My misunderstanding been awhile since my studies but had to consider Air as a fluid in the past figuring equations so I figured you add more moisture then you would increase weight.Warm modecules move quicker than cold/cold heavier maybe two lines of thought are diverging?

[robbielyn]

That very outer band that is touching 96L is it going to separate from 96L or is it going to ingest 96 L? they are close together.

[Sanibel]

I think NHC knows climatology will mean peak season favorability will kick in, overcome the dry air shear condition, and finally allow a Caribbean system to stack and form. This is one that will finally recurve and allow the inflow time to collect instead of being offset by forward speed.

[Javlin]

Javlin, the force for upward acceleration is the buoyancy of the very warm moist air parcels in the updraft of the thunderstorm. These parcels are so much lighter - less dense - than the parcels outside the updraft that they rise rapidly to reach equilibrium. They acheive pretty impressive upward speeds while doing this, and that increases the intensity of the updraft and thus the storm itself.

So the acceleration overcomes the outside forces of weight/pressure(?) till eq. is reached?

[ozonepete]

My misunderstanding been awhile since my studies but had to consider Air as a fluid in the past figuring equations so I figured you add more moisture then you would increase weight.Warm modecules move quicker than cold/cold heavier maybe two lines of thought are diverging?

No. It might be because you think of water as heavier than air, but water vapor molecules are lighter than air molecules. When you add moisture to a column of air in a dry or non-saturated air mass you are replacing heavier air molecules with lighter water vapor molecules, thus you are making the column less dense and more buoyant than the surrounding air.

[tolakram]

Unfortunately I have to steer us back on topic. Someone is welcome to open a thread on general weather terms and conditions in the Talking Tropics forums. Thanks!

[wxman57]

I think NHC knows climatology will mean peak season favorability will kick in, overcome the dry air shear condition, and finally allow a Caribbean system to stack and form. This is one that will finally recurve and allow the inflow time to collect instead of being offset by forward speed.

Take a look at the current level of instability across the Caribbean. It's at May levels! That can't be good for strengthening:

[robbielyn]

also if 95L were to develop off the tail end of the trough which it could it would change to whole track d/t fujiwara affect. I think this has alot of elements to be an uncomplicated storm. models alot of times i have noticed not pick up on these lesser features that impact the main storm ull's can shear a storm apart another storm too close to the main storm can have an impact. I think this is not as clear cut as it appears to be right now.

[ozonepete]

Javlin, the force for upward acceleration is the buoyancy of the very warm moist air parcels in the updraft of the thunderstorm. These parcels are so much lighter - less dense - than the parcels outside the updraft that they rise rapidly to reach equilibrium. They acheive pretty impressive upward speeds while doing this, and that increases the intensity of the updraft and thus the storm itself.

So the acceleration overcomes the outside forces of weight/pressure(?) till eq. is reached?

Yes. It is strong enough that the force of gravity is obviously overcome, and the outside forces such as pressure become neglible, to keep it simple.

[ozonepete]

Ok, we have to get back on topic now. Sorry Mark.

[Weatherfreak000]

Hmmmm.....I'm starting to wonder if it may. Just stay weak and trek west.

[Zeno8]

Hmmmm.....I'm starting to wonder if it may. Just stay weak and trek west.

Yes I do believe cones will be shifting west

[uhvjaguars22]

Most likely may effect honduras if remains weak just like ernesto. hey everyone im new here

[artist]

Most likely may effect honduras if remains weak just like ernesto. hey everyone im new here

welcome!

[chrisjslucia]

Gusty, a question for you.

11 am NHC advisory says:
THE GOVERNMENT OF FRANCE HAS ISSUED A TROPICAL STORM WARNING FOR
MARTINIQUE.

Are the authorities cautious usually or is it assumed Martinique is liable to storm conditions tomorrow? I ask as I look out over Martinique....

[cycloneye]

...AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT APPROACHING THE
DEPRESSION...


SUMMARY OF 200 PM AST...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...15.3N 53.2W
ABOUT 550 MI...885 KM E OF GUADELOUPE
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 18 MPH...29 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES

[shaggy]

Is it me or does it look as if the LLC is becoming exposed better and may be moving more WNW recently?

[Aric Dunn]

Looks like another large burst is about to happen low level cloud deck thickening quite a bit.