CoconutCandy
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Loc: Beautiful Honolulu Hawaii
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Tropical Depression ALETTA remains fairly well coupled in the vertical this morning, and seems to be bucking the SW-erly wind shear for just a while longer than initially expected. Additionally, very deep and vigorous convection continues to flare and pulse near the still very-well defined low level center of circulation.
(Image Courtesy of University of Hawaii Weather Server)
Awaiting further Passive Microwave Satellite Imagery, but a 6:15 am overpass, around the break of day, local basin time, portrayed a fairly well aligned cyclone still, with tight convective signatures wrapping around an apparently small 'calm spot', in a psudo-eyewall feature open to the east. As least as displayed by passive microwave sounding techniques.
Since then, despite attaining the daytime convective *minimum* cycle, fairly respectable convection continues, in fact the Thunderstorms seem to continue to Intensify, as shown in the most recent frames of the IR animated satellite loop and the storm is showing no signs, at present, of loosing it's identity as a cyclone, at least as depressions go.
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Edited by CoconutCandy (Fri May 18 2012 11:53 AM)
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CoconutCandy
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Reged: Fri
Posts: 245
Loc: Beautiful Honolulu Hawaii
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Aloha Friends. In my Original Post, I had speculated that if convective trends had continued, as you see in the Animated Visible Satellite Loop shown here, that Tropical Depression ALETTA might have to be upgraded and re-classified as a tropical storm again.
Well, that didn't happen in the *official advisory*, but is *IS* interesting to note that the Satellite Presentation at 0600Z *WAS* that of a Tropical Storm strength system, so it appears likely that ALETTA *DID*, in fact, strengthen back to storm status, at least for a period of several hours.
NHC Advisory / Discussion: "DESPITE THE HOSTILE ENVIRONMENT OF HIGH SHEAR AND DRY AIR, ALETTA HAS SURVIVED LONGER THAN ANTICIPATED. FURTHERMORE, THE CLOUD PATTERN IS BETTER ORGANIZED THAN 24 HOURS AGO, AND IN FACT, SATELLITE INTENSITY ESTIMATES SUPPORTED TROPICAL STORM INTENSITY AT 0600Z."
Such is the plight with regard to Intensity Forecasting of Tropical Cyclones. Whether it's the the Explosive (and unanticipated) Deepening of Hurricane 'CHARLEY' to Cat 3, just prior to destroying Port Charlotte, or, as is the case here, with Tropical Depression ALETTA's unexpected deepening to what was likely storm status in the face of adversive wind sheer and dry air entrainment.
Obviously, there are (were) vastly different meteorological processes at work in these 2 examples, and of course, a much larger synoptic scale with regard to Hurricane 'CHARLEY', but the issue of sudden, unexpected intensification remains, even to this day, to be problematic for the forecaster, thus fostering ongoing research into this perplexing matter.
Another Classic Example was Hurricane 'OPAL' in 1995, severely affecting Florida's Panhandle.
While awaiting the beginning of the Atlantic Hurricane Season, and the possibility of an early season storm, I'd like to invite the interested, meteorologically inclined reader to peruse the following article on this issue of unanticipated and explosive cyclone intensification, as it occurred with Hurricane 'OPAL', which devastated the Florida Panhandle in '95. Even reading just the 'Abstract', on page 1, makes for interesting and worthwhile reading, in and of itself.
http://journals.ametsoc.org/doi/pdf/10.1175/1520-0493%282000%29128<0322%3AEIOTRI>2.0.CO%3B2
Edited by CoconutCandy (Fri May 18 2012 12:10 PM)
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