ATL: TROPICAL DEPRESSION BONNIE - DISCUSSION

[rockyman]

While the convection is more sheared than yesterday, I am definitely seeing more low level organization...with a distinct spin in the early visible loops...moving toward the Turks & Caicos.

[Stormcenter]

IMO if this does get it's act together and moves into the GOM it will more then likely have to deal with some significant shear. I guess that's why the models aren't making much of this in the GOM. We shall see.

[canes04]

gatorcane & vortex,

I agree with both of you, it does appear to be reorganizing this morning.
Maybe the ULL is finally lifting out.

This can go from nothing to someting very quickly!

[StormClouds63]

http://www.ssd.noaa.gov/goes/east/tatl/wv-l.jpg

A water vapor view of the Atlantic basin this morning. Is this 2010 or 2006? 97L has lots of dry air and shear to overcome if its going to develop beyond an invest.

[Frank2]

True, but it's still to the east of the ULL that is moving slowly west, and that's why some of us were on the ULL wagon yesterday...

And, as said earlier the ULL has sharpened again this morning after weakening overnight, so that's another punch in the stomach for 97L (ouch)...

Frank

[Bocadude85]

I wonder what it is wxman57 is seeing that would make him think this still has a decent shot at development?

[gatorcane]

One of the main issues is that the large island of Hispaniola is impeding any kind of inflow that it wants to get going. Probably by tomorrow at this time, when its in the Bahamas, it will be in a better position to develop.

Very low chance of anything forming today as the NHC mentions in the last TWO.

[cycloneye]

Upper low moving westward.

Water Vapor Loop

[somethingfunny]

http://www.ssd.noaa.gov/goes/east/tatl/wv-l.jpg

A water vapor view of the Atlantic basin this morning. Is this 2010 or 2006? 97L has lots of dry air and shear to overcome if its going to develop beyond an invest.

It IS July. There's a reason the NHC only gives it a 60% chance of development....that's a 40% chance of nothing happening in the next 48 hours.

I still think this will eventually become Bonnie. This isn't 2005 to be sure, but we'll get popping sooner rather than later IMO.

[Bocadude85]

Yes cycloneye the ULL does appear to be moving westward at little quicker now.

[wxman57]

I wonder what it is wxman57 is seeing that would make him think this still has a decent shot at development?

When evaluating development potential, one has to look beyond the current state of disorganization to when the ridge builds to its north tomorrow/Friday. The sudden surge in convection and increasing organization yesterday was not expected, as wind shear was not forecast to diminish until Thursday.

That said, I do think that the environment in its path is more questionable than was indicated by the models yesterday. I'm not sure the shear in the Gulf will be as low as what was being forecast. We'll see.

[canes04]

wxman57,

The area you mentioned this morning is becoming better defined.
I'm looking at 20.9 & 70.7, LLC could be forming.

Yes the ULL needs to lift put, but as gatorcane mentioned it needs to pull away from DR to estbalish better inflow.

[tolakram]

Loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=20

LLC trying hard, but pretty pathetic at the moment.

Shear:

[ConvergenceZone]

Wow, haven't checked in since late yesterday. I've went from really worried about this being a hurricane yesterday afternoon to not worried at all today. I still think it has an outside chance of becomming a tropical storm before it hits Florida, but as every few hours pass without development, it's chances diminish. I"m thinking more likelly just a depression or not anything at all...What a difference a day makes.....Fantastic news for Florida...

[latitude_20]

Not sure what to make of it - looks as if the center of convective activity has relocated to the east of DR, almost back to PR... anyone else concur with that or do I need more java?

Don't focus on that convection so much, look where the wave axis is - nearly to 71W. Look west of the convection for possible LLC formation. It's nearly reached the Turks and Caicos islands now, though not much convection there.

You can see it better using the MIMIC TPW loop. Look at the last image. Mid-level circulation crossing 70W.
http://cimss.ssec.wisc.edu/tropic/real- ... /main.html

[AdamFirst]

Not sure what to make of it - looks as if the center of convective activity has relocated to the east of DR, almost back to PR... anyone else concur with that or do I need more java?

That's what I thought last night as well, and the convection north of the island went poof. It could develop an LLC over there but its having a hard enough time trying to bore down to the surface at its assumed position. Of course redevelopment east raises more red flags.

[Stormcenter]

The mess in the NW Carribean looks more organized then 97L right now.

[clfenwi]

Looks like in addition to the spot canes04 mentioned (20.9N 70.7W), there is/was a competing vortice around 19.7N 69.7W, north of the Samana peninsula of the Dominican Republic; southwest corner of the convection displayed here



Standing by for the forum's mood roller coaster to turn back up...

[jasons2k]

Here are some thoughts from local met Jeff Lindner.

I'm posting not only b/c I respect what Jeff has to say, but also b/c he and I are in the same camp with this system (the southerly/weaker scenario):

Models prog another increase in tropical moisture by Sunday and so rain chances will need to be raised for the second half of the weekend. Additionally, at this point what becomes of 97L if anything will be entering into the eastern Gulf of Mexico. I like the weaker and southern track guidance with an open wave moving more WNW across the Gulf instead of a stronger system moving move toward the NC Gulf coast.

97L:

Area of numerous showers and thunderstorms continues over the Islands of Hispaniola and Puerto Rico this morning, but overall coverage and organization has decreased in the last 12-18 hours. Upper level low NNW of the suspect area is resulting in decent amounts of SW wind shear over the area of interest and this combined with the surrounding higher mountains in the region appear to be limiting development at the moment. Global forecast models are not as aggressive with the system as yesterday. A ridge of high pressure to the north will continue to steer the area toward the WNW on a general track toward the Bahamas, Cuba, and S FL. The hurricane models: GFDL and HWRF turn the system NW shortly and take it toward NE FL which seems unlikely. The GFS, CMC, and ERUO all depict a weaker system moving more westward into the central Gulf of Mexico and this seems at the moment as the more likely solution given the current lack of organization.

[Bocadude85]

That ULL really does look like its getting out of the way now.