ATL: Tropical Depression Fay

[Mecklenburg]

http://www.ghcc.msfc.nasa.gov/GOES/goeseastnheir.html

No centralized cold tops at present.

I agree, while some of the intensity in the convection has waned a bit, the expanse of the convection has improved as well as the curvature of it....

While that's a good note in favor, it's not always determinant. There have been times when the cap is so strong that it'll choke a TS as they near the LAs:



....and sometimes even hurricanes:



(And Karen had one of the biggest circulation envelopes I've ever seen. She would've been a monster major 'cane if she'd toughed it out.)

We know the cap was strong enough to crush invests as recently as last week (although 99L was farther north under stronger sinking than 92 is now).

it's noteworthy that shear was pretty intense in 2007 which hindered CV development... just like what happened to the fates of Ingrid, Karen ,Melissa...do some proper research first honeyko

[MiamiensisWx]

The following post is NOT an official prognosis.

There is one important fact. The models that depict a track directly over the northern Leeward Islands (i.e. Canadian/UKMET) indicate a deeper system within the next ~24 hours. This is clearly not viable, as demonstrated by available data. Although the low level dry air within the boundary layer is gradually mixing out, the thermodynamic environment remains relatively stable, as evidenced by the SAL to the west and northwest. WV data supports this hypothesis as well. It will not preclude deepening, but it will prohibit more rapid organization. Based on the H7-H85 streamline analysis and TAFB surface analysis, a track further south (toward the S Leewards and Puerto Rico/Hispaniola) is more realistic..

I'm confused here...what do you mean by Northern Leewards and Southern Leewards??? North of the Leewards...and moving west, would be T & C and the Bahamas...south of the Leewards is the Windwards and south of that are the Lesser Antilles. At least...that's how I always knew it, so if I'm wrong, please explain?
Thanks!

CaribPR,

I was referring to the southern half (portion) of the Leewards. This portion comprises Guadeloupe, Saint Kitts/Nevis, and Dominica.

[Vortex]

wxman57, but that's normal in DMIN, especially for a developing disturbacne.

I was just making an observation. There was talk of convection increasing and/or wrapping around. I don't see any increase in convection - just the opposite.

I value and respect your opinion but the overall trend IMO has been one of continued slow organization but steady organization since last night. The overall envelope has conitnued to expand and once deep convection forms over the center a more pronounced and tighter LLC will form...

['CaneFreak]

the SAL and capping are two words that are being used in an incorrect manner quite frequently

You can add DMax and DMin to that list as well because it is used way way too much as the explanation for a decrease/increase in convection.

[AJC3]

Was away for a few hours and sat down for a look at 92L. My impression is that convection has diminished in the last 3-4 hours, and that weakening trend continues presently. Doesn't look close to a TD. Maybe tomorrow, maybe never. Needs to develop persistent deep convection first.

Certainly not close to a TD now, I agree. Tomorrow morning, maybe. Things look decently set up for some overnight development in my humble opinion.

I would agree. I think there's likely to be a period of convective bursting reasonably close to the center overnight which should help to create some additional SLP falls and tighten the circulation up.

[wxman57]

I value and respect your opinion but the overall trend IMO has been one of continued slow organization but steady organization since last night. The overall envelope has conitnued to expand and once deep convection forms over the center a more pronounced and tighter LLC will form...

I didn't comment on overall organization - just that convection was diminishing. However, a system that's becoming better organized would typically have increasing convection. I'm not so sure this one will develop. One major negative factor is that it would have to develop on a Monday or Tuesday while I'm at the office. I already told one of our new hires "no more hurricane development on Saturday mornings on his shift!".

[Honeyko]

Honeyko, Karen got hit by shear, that was nothing at all to do with so called capping, I believe Earl was the same as well.

Karen didn't die because she got hit with shear; she died because she stopped generating convection -- similar to 92L not doing much right now despite a seemingly ideal environment for strengthening. Compare to later in the season when nasty shear totally rips into weak TDs which refuse to croak and keep firing one CB near an LLC and plod along for days until conditions improve.

("so-called capping"? Of course there's capping in the tropics: If there wasn't, every cu over 85F would develop into a mushroom cloud.)

[Mecklenburg]

I value and respect your opinion but the overall trend IMO has been one of continued slow organization but steady organization since last night. The overall envelope has conitnued to expand and once deep convection forms over the center a more pronounced and tighter LLC will form...

I didn't comment on overall organization - just that convection was diminishing. However, a system that's becoming better organized would typically have increasing convection. I'm not so sure this one will develop. One major negative factor is that it would have to develop on a Monday or Tuesday while I'm at the office. I already told one of our new hires "no more hurricane development on Saturday mornings on his shift!".

i'm not disappointed if this one goes poof... the models don't care about this system at all... they find futue 93L and 94L more interesting...

[HURAKAN]

[Mecklenburg]

Honeyko, Karen got hit by shear, that was nothing at all to do with so called capping, I believe Earl was the same as well.

Karen didn't die because she got hit with shear; she died because she stopped generating convection -- similar to 92L not doing much right now despite a seemingly ideal environment for strengthening. Compare to later in the season when nasty shear totally rips into weak TDs which refuse to croak and keep firing one CB near an LLC and plod along for days until conditions improve.

("so-called capping"? Of course there's capping in the tropics: If there wasn't, every cu over 85F would develop into a mushroom cloud.)

read this... page 1... maybe it will talk some sense into you...

http://www.nhc.noaa.gov/pdf/TCR-AL122007_Karen.pdf

[MiamiensisWx]

Honeyko, Karen got hit by shear, that was nothing at all to do with so called capping, I believe Earl was the same as well.

Karen didn't die because she got hit with shear; she died because she stopped generating convection -- similar to 92L not doing much right now despite a seemingly ideal environment for strengthening. Compare to later in the season when nasty shear totally rips into weak TDs which refuse to croak and keep firing one CB near an LLC and plod along for days until conditions improve.

That is nonsense.

http://www.nhc.noaa.gov/pdf/TCR-AL122007_Karen.pdf

"Later that day, a sharp upper-level trough to the west of Karen produced a substantial increase in southwesterly vertical shear over the hurricane. Karen quickly lost organization, and it weakened below hurricane status by 0000 UTC 27 September. Later that same day, as southwesterly shear continued to impact the tropical cyclone, the low-level circulation center became exposed to the west and southwest of the deep convection. Karen continued to gradually weaken in an unfavorable upper-level wind environment, and diminished to marginal tropical storm intensity on 28 September. Meanwhile, Karen’s heading changed temporarily from west-northwestward to northward, perhaps due to changes in the convective involvement of the low-level center or to a temporary surge of low-level environmental southerlies. Although intermittent bursts of deep convection occurred near the center, the relentless southwesterly shear caused further weakening. By early on 29 September, Karen weakened to a tropical depression and turned westward in response to the low-level easterly environmental flow. After 1200 UTC 29 September, Karen’s circulation became so distorted that the system could no longer be tracked, indicating dissipation."

[HURAKAN]

Honeyko, Karen got hit by shear, that was nothing at all to do with so called capping, I believe Earl was the same as well.

Karen didn't die because she got hit with shear; she died because she stopped generating convection -- similar to 92L not doing much right now despite a seemingly ideal environment for strengthening. Compare to later in the season when nasty shear totally rips into weak TDs which refuse to croak and keep firing one CB near an LLC and plod along for days until conditions improve.

("so-called capping"? Of course there's capping in the tropics: If there wasn't, every cu over 85F would develop into a mushroom cloud.)

Before posting, read:

"Although intermittent bursts of deep convection occurred near the center, the relentless southwesterly shear caused further weakening. By early on 29 September, Karen weakened to a tropical depression and turned westward in response to the low-level easterly environmental flow. After 1200 UTC 29 September, Karen’s circulation became so distorted that the system could no longer be tracked, indicating dissipation."

Link: http://www.nhc.noaa.gov/pdf/TCR-AL122007_Karen.pdf

[cycloneye]

Is this thread about something that occured last year or about the actual invest 92L?

[coreyl]

Is this thread about something that occured last year or about the actual invest 92L?

I was wondering the same thing.

[Mecklenburg]

Honeyko, Karen got hit by shear, that was nothing at all to do with so called capping, I believe Earl was the same as well.

Karen didn't die because she got hit with shear; she died because she stopped generating convection -- similar to 92L not doing much right now despite a seemingly ideal environment for strengthening. Compare to later in the season when nasty shear totally rips into weak TDs which refuse to croak and keep firing one CB near an LLC and plod along for days until conditions improve.

("so-called capping"? Of course there's capping in the tropics: If there wasn't, every cu over 85F would develop into a mushroom cloud.)

pls do your research first accurately and post it somewhere else... it's kinda off topic

[cycloneye]

Is this thread about something that occured last year or about the actual invest 92L?

[caribepr]

(I'm too tired - getting the quote thing right wasn't going to happen no matter HOW hard I tried!)

"CaribPR,

I was referring to the southern half (portion) of the Leewards. This portion comprises Guadeloupe, Saint Kitts/Nevis, and Dominica."


Ok, I just didn't understand your terminology, including PR in a southerly inclusion. I know it can get confusing (which is why I have maps of the Caribbean everywhere).

[abajan]

All you Caribbean people know better than I, but my geography says there's the Leewards (they're to leeward, downwind) and Windwards (upwind). Both chains comprise the Lesser Antilles, which are all the islands east of the Greater Antilles (Cuba, Hispaniola, Puerto Rico). The Bahamas are a separate thing.

There's also the ABC islands down there, which are west of the Windwards just north of South America...

You are quite correct, Recurve. And the Wiki link you provided is pretty accurate, except that Aruba became independent about a decade ago and Barbados isn't always considered to be one of the Lesser Antilles. This is partly because we are about 100 miles east of the archipelago.

[Honeyko]

Honeyko, Karen got hit by shear, that was nothing at all to do with so called capping, I believe Earl was the same as well.

Karen didn't die because she got hit with shear; she died because she stopped generating convection -- similar to 92L not doing much right now despite a seemingly ideal environment for strengthening. Compare to later in the season when nasty shear totally rips into weak TDs which refuse to croak and keep firing one CB near an LLC and plod along for days until conditions improve.

("so-called capping"? Of course there's capping in the tropics: If there wasn't, every cu over 85F would develop into a mushroom cloud.)

pls do your research first accurately and post it somewhere else... it's kinda off topic

The retort was unnecessary, I "researched" Karen by watching it, and capping is not at all off-topic if a system is not intensifying.

If you look at the topics at any given moment, about 95% of it isn't doing anything because the lapse rate isn't conducive to promoting convection. I.e., it's capped. It's why everybody goes down there to soak up the sun.

"Although intermittent bursts of deep convection occurred near the center, the relentless southwesterly shear caused further weakening. ....Link: http://www.nhc.noaa.gov/pdf/TCR-AL122007_Karen.pdf

Yes; I am familiar with that. But the question is, why didn't Karen develop more rapidly prior to the shear impacting her (at the time there was curiosity as to why she wouldn't develop an eye while outflow was still perfect), and why didn't she put up convection more valiantly despite shear? -- Virtually every storm that runs through the region NE of the LAs is subjected to shear. Many of them bulldoze right through it. Floyd, for instance.

[southerngale]

Could we please try to remember to show a little respect when we post? This isn't directed towards everyone, but after reading many pages, there's a lot of snippy or downright rude comments by some of you. If you're mad or frustrated, try cooling off before you post. Thanks.