Caribbean Development?:Thread 2

[Sanibel]

Do you think the convection will persist over night?

The ragged, pocked look to the convection is a sign of dry air. A better environment would consolidate into one densely moist center. The scattered look is because conditions aren't right. It should convect overnight, but continue to tease like 99L. The only hope is that it hits the peak season threshold for conditions and forms.

[weatherrabbit_tx]

once that ULL gets past it which is due south of florida on the satellite could it ventelate that area and get it going or there other factors that I may not see?

[MiamiensisWx]

Personally, I think this scenario is a classic "slow fuse" development. Most Caribbean August "messes" start as an interaction between a sfc trough, weak upper low, and mid-level energy. First, instability supports divergence-induced convective activity and thunderstorms, but low-level shear is too strong. Later, the upper low fills and moves westward, and it leaves a piece of sfc trough-induced "energy" over the Caribbean Sea. You slowly begin to observe decreasing shear, intermittent convective bursts (but nothing immediately sustained), and increasing low to mid-level vorticity. It takes time for a sfc low formation, but you eventually witness development. Once you get a defined low-level circulation under these increasingly favorable conditions, you can see quick development to a TD, TS, or hurricane (homegrown cyclogenesis). Convective activity sustains itself during the day, and we have an imminent developing tropical system.

I would not write this system away - as I mentioned in a previous post, all ingredients for development are there; look at the weak low-level inflow on most sides of the system. That's a sign of a weak building anticyclone. Actually, it looks more interesting than earlier today - look at this shortwave loop. Note the increasingly "consolidated" appearance of the convection near 16N and 79W. Low-level convergence is very well established across the central Caribbean Sea, so the "fuel" (including instability) for convective thunderstorms has been initiated. The upper low is moving westward across the Florida Keys, so the energy will remain in place across the central Caribbean basin. Additionally, low to mid-level shear is relaxing per obs. I think the stage is set for the beginning stages of cyclogenesis. Upper-level support is becoming more conducive for the establishment of a sfc low (possibly low-level circulation because of the excellent low-level conditions).

Latest shear charts:

http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8shr.html

I think we will soon see our next INVEST within the next few days.

[Sanibel]

once that ULL gets past it which is due south of florida on the satellite could it ventelate that area and get it going or there other factors that I may not see?

I might be wrong, but I thought ULL's in close proximity to disturbances inhibit development rather than aid it. I thought a ULL to the SW would vent a formed cyclone needing offtake of its upper flow. ULL's generally get out of the way of strong cyclones because they form their own environment by the subsidence caused around them by the returning air shot out into the upper by the eye.

We have weird clouds overhead here because of that ULL, by the way.

[Aric Dunn]

Personally, I think this scenario is a classic "slow fuse" development. Most Caribbean August "messes" start as an interaction between a sfc trough, weak upper low, and mid-level energy. First, instability supports divergence-induced convective activity and thunderstorms, but low-level shear is too strong. Later, the upper low fills and moves westward, and it leaves a piece of sfc trough-induced "energy" over the Caribbean Sea. You slowly begin to observe decreasing shear, intermittent convective bursts (but nothing immediately sustained), and increasing low to mid-level vorticity. It takes time for a sfc low formation, but you eventually witness development. Once you get a defined low-level circulation under these increasingly favorable conditions, you can see quick development to a TD, TS, or hurricane (homegrown cyclogenesis). Convective activity sustains itself during the day, and we have an imminent developing tropical system.

I would not write this system away - as I mentioned in a previous post, all ingredients for development are there; look at the weak low-level inflow on most sides of the system. That's a sign of a weak building anticyclone. Actually, it looks more interesting than earlier today - look at this shortwave loop. Note the increasingly "consolidated" appearance of the convection near 16N and 79W. Low-level convergence is very well established across the central Caribbean Sea, so the "fuel" (including instability) for convective thunderstorms has been initiated. The upper low is moving westward across the Florida Keys, so the energy will remain in place across the central Caribbean basin. Additionally, low to mid-level shear is relaxing per obs. I think the stage is set for the beginning stages of cyclogenesis. Upper-level support is becoming more conducive for the establishment of a sfc low (possibly low-level circulation because of the excellent low-level conditions).

Latest shear charts:

http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8shr.html

I think we will soon see our next INVEST within the next few days.

could not have said it better myself....

[cpdaman]

well the east atlantic system may get named before this one in about two days (if either get named)

which leads me to my next question has there ever been a storm that hits an area right before another storm crosses that same area later but the letter of the later system is earlier in the alphebet.

not saying these are headed to the same place, but just a question

and miami great post as usual

[Aric Dunn]

GFS finally develops something from the carribean

moves it towards Texas

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

[dwg71]

GFS finally develops something from the carribean

moves it towards Texas

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

I dont think its anything to worry about, if that is what we get, ill take two, give us a break from the heat.

[Aric Dunn]

GFS finally develops something from the carribean

moves it towards Texas

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

I dont think its anything to worry about, if that is what we get, ill take two, give us a break from the heat.

yeah pretty much..
but thats not the important thing to focus on.. the gfs has not until now developed anything in the carribean from the systems that are down there.. but now that it has means we have a very realiable model developing something. thats important

[dwg71]

Aric, I think using the word "develops" is overstating it a bit. There isnt much there at all. Lets see if NHC has anything to say about it come monday. Nothing to worry about at the moment.

[Aric Dunn]

Aric, I think using the word "develops" is overstating it a bit. There isnt much there at all. Lets see if NHC has anything to say about it come monday. Nothing to worry about at the moment.

nope not worrying at all. its just a change from the previous runs which means some conditions have changed enough for the gfs to actaully show something ( although not impressiveits still a change worth noting) verses before you could barely tell if there was even a wave down there from the previous runs.

[jasons2k]

I'm not concerned about any one model run since we are still a long ways off from any possibilities -- BUT -- over the last few days many model runs have taken either this system or 90L into Texas. I think that's an indication of the pattern right now and I'm worried about the Gulf Coast west of 90 for just about anything that forms.

[Tampa Bay Hurricane]

I'd say slow development...

[Sanibel]

So far we're getting "99L-ed" again...

[Aric Dunn]

So far we're getting "99L-ed" again...

lol yeah almost 99l was around a long long time though not quite there!!

[tailgater]

Check out the area NW of Jamaica.
http://manati.orbit.nesdis.noaa.gov/img ... ap?433,216
Some blow up of T-storms near this area also.

[xironman]

Wind shifts in Kingston

Code: Select all

    3 AM (7) Aug 12    77 (25)    73 (23)    29.91 (1013)    N 9    thunder
   2 AM (6) Aug 12    77 (25)    73 (23)    29.94 (1014)    NNW 7    light rain with thunder; thunder in the vicinity
   1 AM (5) Aug 12    75 (24)    73 (23)    29.97 (1015)    N 3    light rain with thunder; thunder in the vicinity
   Midnight (4) Aug 12    77 (25)    73 (23)    29.97 (1015)    N 6    light rain with thunder; thunder in the vicinity
   11 PM (3) Aug 11    80 (27)    71 (22)    29.97 (1015)    ESE 10    
   10 PM (2) Aug 11    77 (25)    71 (22)    29.94 (1014)    N 3    light rain; thunder in the vicinity

[Nimbus]

This morning we have a Key West ULL producing shear induced convection over the NW Caribbean. The only low level surface energy appears to be down near 15N 79W close to where the convection had been flaring last night. The upper air pattern will get more favorable for development in the western Caribbean as everything shifts west and the shear eases a bit. I'm not sure if there will be enough low level surface energy to get things started. The convection further south around 15n went poof this morning, should refire later if there is still low surface pressure in the area.

[xironman]

At least the GFS finally makes it a low in the SW Gulf http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_078m.gif. The CMC won't seem so lonely.

[srainhoutx]

I'm not concerned about any one model run since we are still a long ways off from any possibilities -- BUT -- over the last few days many model runs have taken either this system or 90L into Texas. I think that's an indication of the pattern right now and I'm worried about the Gulf Coast west of 90 for just about anything that forms.

Watching closely