>Ok, many meteorologists out there are talking about Danny’s structure, where’s his center? Will he be fully tropical or a part of him either baroclinic or of a hybrid nature.
This is in part relation to my post yesterday regarding many storms that form east of the Bahamas or nearer the Southeast Atlantic coast never gets properly developed, therefore keeping the system that’s trying to get fully tropical and fully warm core but has trouble doing so. Why is that? Especially when it’s forming in a “tropical breeding ground region of the world” plus, the waters are very warm, certainly at the surface and to depths enough to support development and future strengthening. One of my key “personal speculations” to why home brew storm formation, seemingly nearer the Carolina coast is that atmospheric conditions, perhaps off the continent (given a west to east air flow across the lower 48) creates two key prohibiting elements, 1) wind shear, perhaps by a nearby low and or association with a trough and 2) dry air that blows off the US mainland. The shear prohibiting Danny and displacing his convective canopy is tilting the weak structure of this storm, so much so that a clearly evident surface circulation center was visible in tightly wound clouds spinning, indicative of Danny’s center! Low level core exposure means, you’ll never see a storm strengthen, deepen or organise when the surface features are exposed to space, there is no verticle structure or verticle stacking essential to allow entropy, intensification of thunderstorms and they must warp FULLY around the center, allow it to excellerate inflow at the surface, building and cooling of cloud tops and then you’ll see strong outflow at the top across the central dense overcast. When storm circulations and there convection is displaced this intricate process can not be completed the cycle of air wrapping inward from out with, then moved vertically upward within the eyewall or core and then released outward at the top.
It seems many storms in this region and close proximity never become fully tropical or have a tough time doing so as the core stuggles to become warm core when the environment within and surrounding is not good enough, closed rotory ciculation and draw the cloud our convective canopy over top of the verticle stacking of surface and mid level low pressure centers with an anticyclone overtop to vent outflow and you have a good, fully tropical system when all this forms over waters at or above 26C.. Remember, from my understanding, baroclinic, cold core lows are formed and driven along a boundary between warm and cold air mass where the jet stream is or nearby, where as tropical systems are driven by themselves and the ocean heat content, and move by the flow of the atmosphere in which their embedded within (around high pressure systems).

I wonder, since storms that move in towards the Carolinas but were born, fully warm core in the lower latitude, deep tropics have better chance at having a more significant HURRICANE THREAT to the Carolinas than say storms that form or try to form at a higher latitude, is there possibly a more hostle environment that supresses “tropical development” and a better chance that tropical transition rather than initial formation straight to warm core, that’s more likely to occue where the atmosphere is much more tropical from bottom to top, a benign atmosphere that lies over the tropical ocean.. a system that forms further north, may have to deal with an environment that has a west to east flow (westerlies) in the lower down “Mid Levels, UP” than say in the deep tropics, plus dry “continental” air and entrainment into a development system that has shear may force a low pressure development process to start off cold to then warm core, rather than straight to warm core, if you understand what I am trying to get at. Basically the environment and NOT ocean is the issue to devlopment of tropical systems this far north and that is why systems often form and stuggle to become much as they hit the Carolinas or Mid-Atlantic, whereas systems that formed in the lower latitudes and move into the Carolinas haven’t issues with hybrid or struggling to be or remain fully tropical, they are more likely to weaken as they interact with ligher latitude westerlies and the presense of mid-latitide atmospheric environment such as deep, multi layered troughs, cool air and dry (continental origin) dry air which may have differing composites or effect on tropical systems than Saharan dust/dry air that crosses thousands of miles of ocean.

What will happen with Danny is still very much unknown, but since I am cutting this post short for another early night, I shall link you to the NHC discussion for expert discussion on Danny’s situation in both structural soundness and forecast track http://www.nhc.noaa.gov/text/refresh/MIATCDAT5+shtml/DDHHMM.shtml and also go to AccuWeather’s Hurricane Center for other great information and check out there detailed video presentation on Danny http://hurricane.accuweather.com/hurricane/atlantic/basin.asp?partner=rss&traveler=0 and http://www.accuweather.com/video-on-demand.asp?video=24528283001?… I shall comment on Danny’s track tomorrow evening.

Thanks for reading.
-Mark