It would appear that Tropical Storm Alberto is having to deal with several constraints this morning.
First and foremost, a good part of the low level circulation is exposed and is nearly totally lacking in any deep convection, albeit along a few cloud streets to the NE, where numerous towering cumulus and a smattering of weak thunderstorms are occurring in the convergent airflow into the cyclone.
The somewhat meager deep convection that does remain, as mentioned, is displaced to the West and NW of the LLCC, and isn't too impressive at that. I had surmised yesterday that deep and sustained 'bursting type' convection, with cloud top temps colder than -70 Celsius, might flare overnight during the convective max cycle.
But that never panned out, with overnight convection, as depicted on IR Satellite loops and excellent Doppler Radar coverage, remaining somewhat lackluster and, plausibly due to the ongoing wind shear, could not manage to wrap completely around the center of circulation, usually a requisite factor for significant intensification to occur.
In this passive microwave image from a polar orbiting satellite, you see the thunderstorms restricted to the Western quadrant only.
Although a Dense Overcast HAS formed over the remaining deep convection, one can't really call it a CENTRAL Dense Overcast (CDO), which is very often the harbinger of (sometimes rapid) intensification, as it does not overlay the LLCC, and the "thermodynamic throughput" of the convective mass that does remain has been insufficient to release the requisite amount of 'latent heat of condensation' required to further warm the nascent developing warm core, in turn, to lower the central pressure substantially, and for the winds to respond accordingly, as is the usual course of events in the typical disturbance --> depression --> tropical storm --> hurricane lifecycle.
The take away here is that Alberto, despite his 'best efforts', has to live with the synoptic deterrents (upper level wind shear and dry air entrainment) and various thermodynamic constrains that are impinging upon it and prohibiting further intensification at this time
I surmise, however, that should Alberto's LLCC remain well offshore and should it find itself squarely over the warm gulf stream again (think oceanic heat content!), AND the ongoing shear to relax just a tad, that the window of opportunity remains open for deep convection to fire and encompass the LLCC and a decent CDO feature to form, that a fairly respectable looking tropical storm may very well blossom yet.
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"Don't Get Stuck on Stupid" - General Honore, following Hurricane Katrina
Edited by CoconutCandy (Sun May 20 2012 11:54 AM)
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