ATL: TROPICAL DEPRESSION BONNIE - DISCUSSION

[HURAKAN]

48 hours

[Stormcenter]

I would agree with that.

Going out on a limb & sticking my neck out - I don't think we are deadling with a Katrina type storm here on July 21.

[Aric Dunn]

well with all the talk about parallels with katrina.. here is a loop from katrina.. its in the same location and moving in the same direction.. also looks the same lol

http://svs.gsfc.nasa.gov/vis/a000000/a0 ... na_sst.mpg

[StormClouds63]

I don't always agree with our pal, Joe, but his reasoning on this system makes good sense. My thanks also to Steve for posting the link. When is Bonnie finally going to make her long-awaited debut?

[HURAKAN]

TPC 48 hours

[Weatherfreak000]

Did Katrina have a massive ULL infront of it? lol.

[Aric Dunn]

well with all the talk about parallels with katrina.. here is a loop from katrina.. its in the same location and moving in the same direction.. also looks the same lol

http://svs.gsfc.nasa.gov/vis/a000000/a0 ... na_sst.mpg

actually this is a better loop.. http://svs.gsfc.nasa.gov/vis/a000000/a0 ... _sstHD.m2v

[Clint_TX]

Did Katrina have a massive ULL infront of it? lol.

I sure think it did

[KWT]

With Katrina I think the ULL eventually aided its outflow.

I think there is a LL turning but its small and could end up just being an eddy...but it looks no worse then Danny from last year to be honest!

[Hurricane]

Poof

[clfenwi]

Refresher on the evolution of pre-Katrina from the NHC report:

The complex genesis of Katrina involved the interaction of a tropical wave, the middle
tropospheric remnants of Tropical Depression Ten, and an upper tropospheric trough. This
trough, located over the western Atlantic and the Bahamas, produced strong westerly shear
across Tropical Depression Ten, causing it to degenerate on 14 August approximately 825 n mi
east of Barbados. The low-level circulation gradually weakened while continuing westward,
and it eventually dissipated on 21 August in the vicinity of Cuba. Meanwhile, a middle
tropospheric circulation originating from Tropical Depression Ten lagged behind and passed
north of the Leeward Islands on 18-19 August. A tropical wave, which departed the west coast
of Africa on 11 August, moved through the Leeward Islands and merged with the middle
tropospheric remnants of Tropical Depression Ten on 19 August and produced a large area of
showers and thunderstorms north of Puerto Rico. This activity continued to move slowly
northwestward, passing north of Hispaniola and then consolidating just east of the Turks and
Caicos during the afternoon of 22 August. Dvorak satellite classifications from the Tropical
Analysis and Forecast Branch (TAFB) of the Tropical Prediction Center (TPC) began at 1800
UTC that day. The upper tropospheric trough weakened as it moved westward toward Florida,
and the shear relaxed enough to allow the system to develop into a tropical depression by 1800
UTC 23 August over the southeastern Bahamas about 175 n mi southeast of Nassau. The
depression was designated Tropical Depression Twelve rather than “Ten” because a separate
tropical wave appeared to be partially responsible for the cyclogenesis, and, more importantly,
the low-level circulation of Tropical Depression Ten was clearly not involved.

Useful reminder, not so much for the future prospects of this storm intensity-wise or anything, but as an example of systems developing in the Bahamas after passing by Hispanola. I think if you were to look at all-time tropical cyclogenesis points, you would find many more in the vicinity of 25N/75W than, say, 20N/70W.

(edited to add link)

[gatorcane]

I noticed there is a nice band of convection now arching south and southwest south of Hispaniola to south of Cuba that may be the first sign a good moisture plume is feeding the system. Also convection has steadily been increasing throughout the day near the "LLC." SSTs should be on the increase later tonight into tomorrow. Will be interesting to see how it responds to better conditions.

[Hurricane]

Is recon cancelled for today?

[NOLA2010]

Is recon cancelled for today?

Yes it was. They are going to try again tomorrow though

[cycloneye]

18z Best Track

AL, 97, 2010072118, , BEST, 0, 213N, 713W, 30, 1013, DB

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 010.invest

[thetruesms]

Refresher on the evolution of pre-Katrina from the NHC report:

Useful reminder, not so much for the future prospects of this storm intensity-wise or anything, but as an example of systems developing in the Bahamas after passing by Hispanola. I think if you were to look at all-time tropical cyclogenesis points, you would find many more in the vicinity of 25N/75W than, say, 20N/70W.

(edited to add link)

I think it touches on the forecast problem with this system, as well. The ULL ahead of Katrina weakened as it moved to the west. This one is progged to actually strengthen a bit as it moves towards Florida - the question is whether it will move quickly enough to give 97L some space to grow.

Is recon cancelled for today?

Yes and no. There will still be a G-IV mission to get data from some dropsondes in the surrounding environment.

[HURAKAN]

18z

[Aric Dunn]

18z

any reporting stations from those islands..

[wzrgirl1]

I do have to say that I am more confused then I have ever been. I don't think I have ever seen such distinctly different camps on the development of a storm. I guess I will need to form my opinion based on the facts presented. I mean there usually are discrepencies in opinions but in this case.....it seems as if there are more then normal. Maybe I just need to step away from my laptop for a few hours and come back. I think I am becoming obsessed.

[HURAKAN]

any reporting stations from those islands..